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com/vendor/github.com/mattn/go-sqlite3/sqlite3-binding.c

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  1. #ifndef USE_LIBSQLITE3

  2. /******************************************************************************

  3. ** This file is an amalgamation of many separate C source files from SQLite

  4. ** version 3.29.0.  By combining all the individual C code files into this

  5. ** single large file, the entire code can be compiled as a single translation

  6. ** unit.  This allows many compilers to do optimizations that would not be

  7. ** possible if the files were compiled separately.  Performance improvements

  8. ** of 5% or more are commonly seen when SQLite is compiled as a single

  9. ** translation unit.

  10. **

  11. ** This file is all you need to compile SQLite.  To use SQLite in other

  12. ** programs, you need this file and the "sqlite3.h" header file that defines

  13. ** the programming interface to the SQLite library.  (If you do not have

  14. ** the "sqlite3.h" header file at hand, you will find a copy embedded within

  15. ** the text of this file.  Search for "Begin file sqlite3.h" to find the start

  16. ** of the embedded sqlite3.h header file.) Additional code files may be needed

  17. ** if you want a wrapper to interface SQLite with your choice of programming

  18. ** language. The code for the "sqlite3" command-line shell is also in a

  19. ** separate file. This file contains only code for the core SQLite library.

  20. */

  21. #define SQLITE_CORE 1

  22. #define SQLITE_AMALGAMATION 1

  23. #ifndef SQLITE_PRIVATE

  24. # define SQLITE_PRIVATE static

  25. #endif

  26. /************** Begin file ctime.c *******************************************/

  27. /*

  28. ** 2010 February 23

  29. **

  30. ** The author disclaims copyright to this source code.  In place of

  31. ** a legal notice, here is a blessing:

  32. **

  33. **    May you do good and not evil.

  34. **    May you find forgiveness for yourself and forgive others.

  35. **    May you share freely, never taking more than you give.

  36. **

  37. *************************************************************************

  38. **

  39. ** This file implements routines used to report what compile-time options

  40. ** SQLite was built with.

  41. */

  42. 

  43. #ifndef SQLITE_OMIT_COMPILEOPTION_DIAGS /* IMP: R-16824-07538 */

  44. 

  45. /*

  46. ** Include the configuration header output by 'configure' if we're using the

  47. ** autoconf-based build

  48. */

  49. #if defined(_HAVE_SQLITE_CONFIG_H) && !defined(SQLITECONFIG_H)

  50. #include "config.h"

  51. #define SQLITECONFIG_H 1

  52. #endif

  53. 

  54. /* These macros are provided to "stringify" the value of the define

  55. ** for those options in which the value is meaningful. */

  56. #define CTIMEOPT_VAL_(opt) #opt

  57. #define CTIMEOPT_VAL(opt) CTIMEOPT_VAL_(opt)

  58. 

  59. /* Like CTIMEOPT_VAL, but especially for SQLITE_DEFAULT_LOOKASIDE. This

  60. ** option requires a separate macro because legal values contain a single

  61. ** comma. e.g. (-DSQLITE_DEFAULT_LOOKASIDE="100,100") */

  62. #define CTIMEOPT_VAL2_(opt1,opt2) #opt1 "," #opt2

  63. #define CTIMEOPT_VAL2(opt) CTIMEOPT_VAL2_(opt)

  64. 

  65. /*

  66. ** An array of names of all compile-time options.  This array should 

  67. ** be sorted A-Z.

  68. **

  69. ** This array looks large, but in a typical installation actually uses

  70. ** only a handful of compile-time options, so most times this array is usually

  71. ** rather short and uses little memory space.

  72. */

  73. static const char * const sqlite3azCompileOpt[] = {

  74. 

  75. /* 

  76. ** BEGIN CODE GENERATED BY tool/mkctime.tcl 

  77. */

  78. #if SQLITE_32BIT_ROWID

  79.   "32BIT_ROWID",

  80. #endif

  81. #if SQLITE_4_BYTE_ALIGNED_MALLOC

  82.   "4_BYTE_ALIGNED_MALLOC",

  83. #endif

  84. #if SQLITE_64BIT_STATS

  85.   "64BIT_STATS",

  86. #endif

  87. #if SQLITE_ALLOW_COVERING_INDEX_SCAN

  88.   "ALLOW_COVERING_INDEX_SCAN",

  89. #endif

  90. #if SQLITE_ALLOW_URI_AUTHORITY

  91.   "ALLOW_URI_AUTHORITY",

  92. #endif

  93. #ifdef SQLITE_BITMASK_TYPE

  94.   "BITMASK_TYPE=" CTIMEOPT_VAL(SQLITE_BITMASK_TYPE),

  95. #endif

  96. #if SQLITE_BUG_COMPATIBLE_20160819

  97.   "BUG_COMPATIBLE_20160819",

  98. #endif

  99. #if SQLITE_CASE_SENSITIVE_LIKE

  100.   "CASE_SENSITIVE_LIKE",

  101. #endif

  102. #if SQLITE_CHECK_PAGES

  103.   "CHECK_PAGES",

  104. #endif

  105. #if defined(__clang__) && defined(__clang_major__)

  106.   "COMPILER=clang-" CTIMEOPT_VAL(__clang_major__) "."

  107.                     CTIMEOPT_VAL(__clang_minor__) "."

  108.                     CTIMEOPT_VAL(__clang_patchlevel__),

  109. #elif defined(_MSC_VER)

  110.   "COMPILER=msvc-" CTIMEOPT_VAL(_MSC_VER),

  111. #elif defined(__GNUC__) && defined(__VERSION__)

  112.   "COMPILER=gcc-" __VERSION__,

  113. #endif

  114. #if SQLITE_COVERAGE_TEST

  115.   "COVERAGE_TEST",

  116. #endif

  117. #if SQLITE_DEBUG

  118.   "DEBUG",

  119. #endif

  120. #if SQLITE_DEFAULT_AUTOMATIC_INDEX

  121.   "DEFAULT_AUTOMATIC_INDEX",

  122. #endif

  123. #if SQLITE_DEFAULT_AUTOVACUUM

  124.   "DEFAULT_AUTOVACUUM",

  125. #endif

  126. #ifdef SQLITE_DEFAULT_CACHE_SIZE

  127.   "DEFAULT_CACHE_SIZE=" CTIMEOPT_VAL(SQLITE_DEFAULT_CACHE_SIZE),

  128. #endif

  129. #if SQLITE_DEFAULT_CKPTFULLFSYNC

  130.   "DEFAULT_CKPTFULLFSYNC",

  131. #endif

  132. #ifdef SQLITE_DEFAULT_FILE_FORMAT

  133.   "DEFAULT_FILE_FORMAT=" CTIMEOPT_VAL(SQLITE_DEFAULT_FILE_FORMAT),

  134. #endif

  135. #ifdef SQLITE_DEFAULT_FILE_PERMISSIONS

  136.   "DEFAULT_FILE_PERMISSIONS=" CTIMEOPT_VAL(SQLITE_DEFAULT_FILE_PERMISSIONS),

  137. #endif

  138. #if SQLITE_DEFAULT_FOREIGN_KEYS

  139.   "DEFAULT_FOREIGN_KEYS",

  140. #endif

  141. #ifdef SQLITE_DEFAULT_JOURNAL_SIZE_LIMIT

  142.   "DEFAULT_JOURNAL_SIZE_LIMIT=" CTIMEOPT_VAL(SQLITE_DEFAULT_JOURNAL_SIZE_LIMIT),

  143. #endif

  144. #ifdef SQLITE_DEFAULT_LOCKING_MODE

  145.   "DEFAULT_LOCKING_MODE=" CTIMEOPT_VAL(SQLITE_DEFAULT_LOCKING_MODE),

  146. #endif

  147. #ifdef SQLITE_DEFAULT_LOOKASIDE

  148.   "DEFAULT_LOOKASIDE=" CTIMEOPT_VAL2(SQLITE_DEFAULT_LOOKASIDE),

  149. #endif

  150. #if SQLITE_DEFAULT_MEMSTATUS

  151.   "DEFAULT_MEMSTATUS",

  152. #endif

  153. #ifdef SQLITE_DEFAULT_MMAP_SIZE

  154.   "DEFAULT_MMAP_SIZE=" CTIMEOPT_VAL(SQLITE_DEFAULT_MMAP_SIZE),

  155. #endif

  156. #ifdef SQLITE_DEFAULT_PAGE_SIZE

  157.   "DEFAULT_PAGE_SIZE=" CTIMEOPT_VAL(SQLITE_DEFAULT_PAGE_SIZE),

  158. #endif

  159. #ifdef SQLITE_DEFAULT_PCACHE_INITSZ

  160.   "DEFAULT_PCACHE_INITSZ=" CTIMEOPT_VAL(SQLITE_DEFAULT_PCACHE_INITSZ),

  161. #endif

  162. #ifdef SQLITE_DEFAULT_PROXYDIR_PERMISSIONS

  163.   "DEFAULT_PROXYDIR_PERMISSIONS=" CTIMEOPT_VAL(SQLITE_DEFAULT_PROXYDIR_PERMISSIONS),

  164. #endif

  165. #if SQLITE_DEFAULT_RECURSIVE_TRIGGERS

  166.   "DEFAULT_RECURSIVE_TRIGGERS",

  167. #endif

  168. #ifdef SQLITE_DEFAULT_ROWEST

  169.   "DEFAULT_ROWEST=" CTIMEOPT_VAL(SQLITE_DEFAULT_ROWEST),

  170. #endif

  171. #ifdef SQLITE_DEFAULT_SECTOR_SIZE

  172.   "DEFAULT_SECTOR_SIZE=" CTIMEOPT_VAL(SQLITE_DEFAULT_SECTOR_SIZE),

  173. #endif

  174. #ifdef SQLITE_DEFAULT_SYNCHRONOUS

  175.   "DEFAULT_SYNCHRONOUS=" CTIMEOPT_VAL(SQLITE_DEFAULT_SYNCHRONOUS),

  176. #endif

  177. #ifdef SQLITE_DEFAULT_WAL_AUTOCHECKPOINT

  178.   "DEFAULT_WAL_AUTOCHECKPOINT=" CTIMEOPT_VAL(SQLITE_DEFAULT_WAL_AUTOCHECKPOINT),

  179. #endif

  180. #ifdef SQLITE_DEFAULT_WAL_SYNCHRONOUS

  181.   "DEFAULT_WAL_SYNCHRONOUS=" CTIMEOPT_VAL(SQLITE_DEFAULT_WAL_SYNCHRONOUS),

  182. #endif

  183. #ifdef SQLITE_DEFAULT_WORKER_THREADS

  184.   "DEFAULT_WORKER_THREADS=" CTIMEOPT_VAL(SQLITE_DEFAULT_WORKER_THREADS),

  185. #endif

  186. #if SQLITE_DIRECT_OVERFLOW_READ

  187.   "DIRECT_OVERFLOW_READ",

  188. #endif

  189. #if SQLITE_DISABLE_DIRSYNC

  190.   "DISABLE_DIRSYNC",

  191. #endif

  192. #if SQLITE_DISABLE_FTS3_UNICODE

  193.   "DISABLE_FTS3_UNICODE",

  194. #endif

  195. #if SQLITE_DISABLE_FTS4_DEFERRED

  196.   "DISABLE_FTS4_DEFERRED",

  197. #endif

  198. #if SQLITE_DISABLE_INTRINSIC

  199.   "DISABLE_INTRINSIC",

  200. #endif

  201. #if SQLITE_DISABLE_LFS

  202.   "DISABLE_LFS",

  203. #endif

  204. #if SQLITE_DISABLE_PAGECACHE_OVERFLOW_STATS

  205.   "DISABLE_PAGECACHE_OVERFLOW_STATS",

  206. #endif

  207. #if SQLITE_DISABLE_SKIPAHEAD_DISTINCT

  208.   "DISABLE_SKIPAHEAD_DISTINCT",

  209. #endif

  210. #ifdef SQLITE_ENABLE_8_3_NAMES

  211.   "ENABLE_8_3_NAMES=" CTIMEOPT_VAL(SQLITE_ENABLE_8_3_NAMES),

  212. #endif

  213. #if SQLITE_ENABLE_API_ARMOR

  214.   "ENABLE_API_ARMOR",

  215. #endif

  216. #if SQLITE_ENABLE_ATOMIC_WRITE

  217.   "ENABLE_ATOMIC_WRITE",

  218. #endif

  219. #if SQLITE_ENABLE_BATCH_ATOMIC_WRITE

  220.   "ENABLE_BATCH_ATOMIC_WRITE",

  221. #endif

  222. #if SQLITE_ENABLE_CEROD

  223.   "ENABLE_CEROD=" CTIMEOPT_VAL(SQLITE_ENABLE_CEROD),

  224. #endif

  225. #if SQLITE_ENABLE_COLUMN_METADATA

  226.   "ENABLE_COLUMN_METADATA",

  227. #endif

  228. #if SQLITE_ENABLE_COLUMN_USED_MASK

  229.   "ENABLE_COLUMN_USED_MASK",

  230. #endif

  231. #if SQLITE_ENABLE_COSTMULT

  232.   "ENABLE_COSTMULT",

  233. #endif

  234. #if SQLITE_ENABLE_CURSOR_HINTS

  235.   "ENABLE_CURSOR_HINTS",

  236. #endif

  237. #if SQLITE_ENABLE_DBSTAT_VTAB

  238.   "ENABLE_DBSTAT_VTAB",

  239. #endif

  240. #if SQLITE_ENABLE_EXPENSIVE_ASSERT

  241.   "ENABLE_EXPENSIVE_ASSERT",

  242. #endif

  243. #if SQLITE_ENABLE_FTS1

  244.   "ENABLE_FTS1",

  245. #endif

  246. #if SQLITE_ENABLE_FTS2

  247.   "ENABLE_FTS2",

  248. #endif

  249. #if SQLITE_ENABLE_FTS3

  250.   "ENABLE_FTS3",

  251. #endif

  252. #if SQLITE_ENABLE_FTS3_PARENTHESIS

  253.   "ENABLE_FTS3_PARENTHESIS",

  254. #endif

  255. #if SQLITE_ENABLE_FTS3_TOKENIZER

  256.   "ENABLE_FTS3_TOKENIZER",

  257. #endif

  258. #if SQLITE_ENABLE_FTS4

  259.   "ENABLE_FTS4",

  260. #endif

  261. #if SQLITE_ENABLE_FTS5

  262.   "ENABLE_FTS5",

  263. #endif

  264. #if SQLITE_ENABLE_GEOPOLY

  265.   "ENABLE_GEOPOLY",

  266. #endif

  267. #if SQLITE_ENABLE_HIDDEN_COLUMNS

  268.   "ENABLE_HIDDEN_COLUMNS",

  269. #endif

  270. #if SQLITE_ENABLE_ICU

  271.   "ENABLE_ICU",

  272. #endif

  273. #if SQLITE_ENABLE_IOTRACE

  274.   "ENABLE_IOTRACE",

  275. #endif

  276. #if SQLITE_ENABLE_JSON1

  277.   "ENABLE_JSON1",

  278. #endif

  279. #if SQLITE_ENABLE_LOAD_EXTENSION

  280.   "ENABLE_LOAD_EXTENSION",

  281. #endif

  282. #ifdef SQLITE_ENABLE_LOCKING_STYLE

  283.   "ENABLE_LOCKING_STYLE=" CTIMEOPT_VAL(SQLITE_ENABLE_LOCKING_STYLE),

  284. #endif

  285. #if SQLITE_ENABLE_MEMORY_MANAGEMENT

  286.   "ENABLE_MEMORY_MANAGEMENT",

  287. #endif

  288. #if SQLITE_ENABLE_MEMSYS3

  289.   "ENABLE_MEMSYS3",

  290. #endif

  291. #if SQLITE_ENABLE_MEMSYS5

  292.   "ENABLE_MEMSYS5",

  293. #endif

  294. #if SQLITE_ENABLE_MULTIPLEX

  295.   "ENABLE_MULTIPLEX",

  296. #endif

  297. #if SQLITE_ENABLE_NORMALIZE

  298.   "ENABLE_NORMALIZE",

  299. #endif

  300. #if SQLITE_ENABLE_NULL_TRIM

  301.   "ENABLE_NULL_TRIM",

  302. #endif

  303. #if SQLITE_ENABLE_OVERSIZE_CELL_CHECK

  304.   "ENABLE_OVERSIZE_CELL_CHECK",

  305. #endif

  306. #if SQLITE_ENABLE_PREUPDATE_HOOK

  307.   "ENABLE_PREUPDATE_HOOK",

  308. #endif

  309. #if SQLITE_ENABLE_QPSG

  310.   "ENABLE_QPSG",

  311. #endif

  312. #if SQLITE_ENABLE_RBU

  313.   "ENABLE_RBU",

  314. #endif

  315. #if SQLITE_ENABLE_RTREE

  316.   "ENABLE_RTREE",

  317. #endif

  318. #if SQLITE_ENABLE_SELECTTRACE

  319.   "ENABLE_SELECTTRACE",

  320. #endif

  321. #if SQLITE_ENABLE_SESSION

  322.   "ENABLE_SESSION",

  323. #endif

  324. #if SQLITE_ENABLE_SNAPSHOT

  325.   "ENABLE_SNAPSHOT",

  326. #endif

  327. #if SQLITE_ENABLE_SORTER_REFERENCES

  328.   "ENABLE_SORTER_REFERENCES",

  329. #endif

  330. #if SQLITE_ENABLE_SQLLOG

  331.   "ENABLE_SQLLOG",

  332. #endif

  333. #if defined(SQLITE_ENABLE_STAT4)

  334.   "ENABLE_STAT4",

  335. #elif defined(SQLITE_ENABLE_STAT3)

  336.   "ENABLE_STAT3",

  337. #endif

  338. #if SQLITE_ENABLE_STMTVTAB

  339.   "ENABLE_STMTVTAB",

  340. #endif

  341. #if SQLITE_ENABLE_STMT_SCANSTATUS

  342.   "ENABLE_STMT_SCANSTATUS",

  343. #endif

  344. #if SQLITE_ENABLE_UNKNOWN_SQL_FUNCTION

  345.   "ENABLE_UNKNOWN_SQL_FUNCTION",

  346. #endif

  347. #if SQLITE_ENABLE_UNLOCK_NOTIFY

  348.   "ENABLE_UNLOCK_NOTIFY",

  349. #endif

  350. #if SQLITE_ENABLE_UPDATE_DELETE_LIMIT

  351.   "ENABLE_UPDATE_DELETE_LIMIT",

  352. #endif

  353. #if SQLITE_ENABLE_URI_00_ERROR

  354.   "ENABLE_URI_00_ERROR",

  355. #endif

  356. #if SQLITE_ENABLE_VFSTRACE

  357.   "ENABLE_VFSTRACE",

  358. #endif

  359. #if SQLITE_ENABLE_WHERETRACE

  360.   "ENABLE_WHERETRACE",

  361. #endif

  362. #if SQLITE_ENABLE_ZIPVFS

  363.   "ENABLE_ZIPVFS",

  364. #endif

  365. #if SQLITE_EXPLAIN_ESTIMATED_ROWS

  366.   "EXPLAIN_ESTIMATED_ROWS",

  367. #endif

  368. #if SQLITE_EXTRA_IFNULLROW

  369.   "EXTRA_IFNULLROW",

  370. #endif

  371. #ifdef SQLITE_EXTRA_INIT

  372.   "EXTRA_INIT=" CTIMEOPT_VAL(SQLITE_EXTRA_INIT),

  373. #endif

  374. #ifdef SQLITE_EXTRA_SHUTDOWN

  375.   "EXTRA_SHUTDOWN=" CTIMEOPT_VAL(SQLITE_EXTRA_SHUTDOWN),

  376. #endif

  377. #ifdef SQLITE_FTS3_MAX_EXPR_DEPTH

  378.   "FTS3_MAX_EXPR_DEPTH=" CTIMEOPT_VAL(SQLITE_FTS3_MAX_EXPR_DEPTH),

  379. #endif

  380. #if SQLITE_FTS5_ENABLE_TEST_MI

  381.   "FTS5_ENABLE_TEST_MI",

  382. #endif

  383. #if SQLITE_FTS5_NO_WITHOUT_ROWID

  384.   "FTS5_NO_WITHOUT_ROWID",

  385. #endif

  386. #if SQLITE_HAS_CODEC

  387.   "HAS_CODEC",

  388. #endif

  389. #if HAVE_ISNAN || SQLITE_HAVE_ISNAN

  390.   "HAVE_ISNAN",

  391. #endif

  392. #if SQLITE_HOMEGROWN_RECURSIVE_MUTEX

  393.   "HOMEGROWN_RECURSIVE_MUTEX",

  394. #endif

  395. #if SQLITE_IGNORE_AFP_LOCK_ERRORS

  396.   "IGNORE_AFP_LOCK_ERRORS",

  397. #endif

  398. #if SQLITE_IGNORE_FLOCK_LOCK_ERRORS

  399.   "IGNORE_FLOCK_LOCK_ERRORS",

  400. #endif

  401. #if SQLITE_INLINE_MEMCPY

  402.   "INLINE_MEMCPY",

  403. #endif

  404. #if SQLITE_INT64_TYPE

  405.   "INT64_TYPE",

  406. #endif

  407. #ifdef SQLITE_INTEGRITY_CHECK_ERROR_MAX

  408.   "INTEGRITY_CHECK_ERROR_MAX=" CTIMEOPT_VAL(SQLITE_INTEGRITY_CHECK_ERROR_MAX),

  409. #endif

  410. #if SQLITE_LIKE_DOESNT_MATCH_BLOBS

  411.   "LIKE_DOESNT_MATCH_BLOBS",

  412. #endif

  413. #if SQLITE_LOCK_TRACE

  414.   "LOCK_TRACE",

  415. #endif

  416. #if SQLITE_LOG_CACHE_SPILL

  417.   "LOG_CACHE_SPILL",

  418. #endif

  419. #ifdef SQLITE_MALLOC_SOFT_LIMIT

  420.   "MALLOC_SOFT_LIMIT=" CTIMEOPT_VAL(SQLITE_MALLOC_SOFT_LIMIT),

  421. #endif

  422. #ifdef SQLITE_MAX_ATTACHED

  423.   "MAX_ATTACHED=" CTIMEOPT_VAL(SQLITE_MAX_ATTACHED),

  424. #endif

  425. #ifdef SQLITE_MAX_COLUMN

  426.   "MAX_COLUMN=" CTIMEOPT_VAL(SQLITE_MAX_COLUMN),

  427. #endif

  428. #ifdef SQLITE_MAX_COMPOUND_SELECT

  429.   "MAX_COMPOUND_SELECT=" CTIMEOPT_VAL(SQLITE_MAX_COMPOUND_SELECT),

  430. #endif

  431. #ifdef SQLITE_MAX_DEFAULT_PAGE_SIZE

  432.   "MAX_DEFAULT_PAGE_SIZE=" CTIMEOPT_VAL(SQLITE_MAX_DEFAULT_PAGE_SIZE),

  433. #endif

  434. #ifdef SQLITE_MAX_EXPR_DEPTH

  435.   "MAX_EXPR_DEPTH=" CTIMEOPT_VAL(SQLITE_MAX_EXPR_DEPTH),

  436. #endif

  437. #ifdef SQLITE_MAX_FUNCTION_ARG

  438.   "MAX_FUNCTION_ARG=" CTIMEOPT_VAL(SQLITE_MAX_FUNCTION_ARG),

  439. #endif

  440. #ifdef SQLITE_MAX_LENGTH

  441.   "MAX_LENGTH=" CTIMEOPT_VAL(SQLITE_MAX_LENGTH),

  442. #endif

  443. #ifdef SQLITE_MAX_LIKE_PATTERN_LENGTH

  444.   "MAX_LIKE_PATTERN_LENGTH=" CTIMEOPT_VAL(SQLITE_MAX_LIKE_PATTERN_LENGTH),

  445. #endif

  446. #ifdef SQLITE_MAX_MEMORY

  447.   "MAX_MEMORY=" CTIMEOPT_VAL(SQLITE_MAX_MEMORY),

  448. #endif

  449. #ifdef SQLITE_MAX_MMAP_SIZE

  450.   "MAX_MMAP_SIZE=" CTIMEOPT_VAL(SQLITE_MAX_MMAP_SIZE),

  451. #endif

  452. #ifdef SQLITE_MAX_MMAP_SIZE_

  453.   "MAX_MMAP_SIZE_=" CTIMEOPT_VAL(SQLITE_MAX_MMAP_SIZE_),

  454. #endif

  455. #ifdef SQLITE_MAX_PAGE_COUNT

  456.   "MAX_PAGE_COUNT=" CTIMEOPT_VAL(SQLITE_MAX_PAGE_COUNT),

  457. #endif

  458. #ifdef SQLITE_MAX_PAGE_SIZE

  459.   "MAX_PAGE_SIZE=" CTIMEOPT_VAL(SQLITE_MAX_PAGE_SIZE),

  460. #endif

  461. #ifdef SQLITE_MAX_SCHEMA_RETRY

  462.   "MAX_SCHEMA_RETRY=" CTIMEOPT_VAL(SQLITE_MAX_SCHEMA_RETRY),

  463. #endif

  464. #ifdef SQLITE_MAX_SQL_LENGTH

  465.   "MAX_SQL_LENGTH=" CTIMEOPT_VAL(SQLITE_MAX_SQL_LENGTH),

  466. #endif

  467. #ifdef SQLITE_MAX_TRIGGER_DEPTH

  468.   "MAX_TRIGGER_DEPTH=" CTIMEOPT_VAL(SQLITE_MAX_TRIGGER_DEPTH),

  469. #endif

  470. #ifdef SQLITE_MAX_VARIABLE_NUMBER

  471.   "MAX_VARIABLE_NUMBER=" CTIMEOPT_VAL(SQLITE_MAX_VARIABLE_NUMBER),

  472. #endif

  473. #ifdef SQLITE_MAX_VDBE_OP

  474.   "MAX_VDBE_OP=" CTIMEOPT_VAL(SQLITE_MAX_VDBE_OP),

  475. #endif

  476. #ifdef SQLITE_MAX_WORKER_THREADS

  477.   "MAX_WORKER_THREADS=" CTIMEOPT_VAL(SQLITE_MAX_WORKER_THREADS),

  478. #endif

  479. #if SQLITE_MEMDEBUG

  480.   "MEMDEBUG",

  481. #endif

  482. #if SQLITE_MIXED_ENDIAN_64BIT_FLOAT

  483.   "MIXED_ENDIAN_64BIT_FLOAT",

  484. #endif

  485. #if SQLITE_MMAP_READWRITE

  486.   "MMAP_READWRITE",

  487. #endif

  488. #if SQLITE_MUTEX_NOOP

  489.   "MUTEX_NOOP",

  490. #endif

  491. #if SQLITE_MUTEX_NREF

  492.   "MUTEX_NREF",

  493. #endif

  494. #if SQLITE_MUTEX_OMIT

  495.   "MUTEX_OMIT",

  496. #endif

  497. #if SQLITE_MUTEX_PTHREADS

  498.   "MUTEX_PTHREADS",

  499. #endif

  500. #if SQLITE_MUTEX_W32

  501.   "MUTEX_W32",

  502. #endif

  503. #if SQLITE_NEED_ERR_NAME

  504.   "NEED_ERR_NAME",

  505. #endif

  506. #if SQLITE_NOINLINE

  507.   "NOINLINE",

  508. #endif

  509. #if SQLITE_NO_SYNC

  510.   "NO_SYNC",

  511. #endif

  512. #if SQLITE_OMIT_ALTERTABLE

  513.   "OMIT_ALTERTABLE",

  514. #endif

  515. #if SQLITE_OMIT_ANALYZE

  516.   "OMIT_ANALYZE",

  517. #endif

  518. #if SQLITE_OMIT_ATTACH

  519.   "OMIT_ATTACH",

  520. #endif

  521. #if SQLITE_OMIT_AUTHORIZATION

  522.   "OMIT_AUTHORIZATION",

  523. #endif

  524. #if SQLITE_OMIT_AUTOINCREMENT

  525.   "OMIT_AUTOINCREMENT",

  526. #endif

  527. #if SQLITE_OMIT_AUTOINIT

  528.   "OMIT_AUTOINIT",

  529. #endif

  530. #if SQLITE_OMIT_AUTOMATIC_INDEX

  531.   "OMIT_AUTOMATIC_INDEX",

  532. #endif

  533. #if SQLITE_OMIT_AUTORESET

  534.   "OMIT_AUTORESET",

  535. #endif

  536. #if SQLITE_OMIT_AUTOVACUUM

  537.   "OMIT_AUTOVACUUM",

  538. #endif

  539. #if SQLITE_OMIT_BETWEEN_OPTIMIZATION

  540.   "OMIT_BETWEEN_OPTIMIZATION",

  541. #endif

  542. #if SQLITE_OMIT_BLOB_LITERAL

  543.   "OMIT_BLOB_LITERAL",

  544. #endif

  545. #if SQLITE_OMIT_BTREECOUNT

  546.   "OMIT_BTREECOUNT",

  547. #endif

  548. #if SQLITE_OMIT_CAST

  549.   "OMIT_CAST",

  550. #endif

  551. #if SQLITE_OMIT_CHECK

  552.   "OMIT_CHECK",

  553. #endif

  554. #if SQLITE_OMIT_COMPLETE

  555.   "OMIT_COMPLETE",

  556. #endif

  557. #if SQLITE_OMIT_COMPOUND_SELECT

  558.   "OMIT_COMPOUND_SELECT",

  559. #endif

  560. #if SQLITE_OMIT_CONFLICT_CLAUSE

  561.   "OMIT_CONFLICT_CLAUSE",

  562. #endif

  563. #if SQLITE_OMIT_CTE

  564.   "OMIT_CTE",

  565. #endif

  566. #if SQLITE_OMIT_DATETIME_FUNCS

  567.   "OMIT_DATETIME_FUNCS",

  568. #endif

  569. #if SQLITE_OMIT_DECLTYPE

  570.   "OMIT_DECLTYPE",

  571. #endif

  572. #if SQLITE_OMIT_DEPRECATED

  573.   "OMIT_DEPRECATED",

  574. #endif

  575. #if SQLITE_OMIT_DISKIO

  576.   "OMIT_DISKIO",

  577. #endif

  578. #if SQLITE_OMIT_EXPLAIN

  579.   "OMIT_EXPLAIN",

  580. #endif

  581. #if SQLITE_OMIT_FLAG_PRAGMAS

  582.   "OMIT_FLAG_PRAGMAS",

  583. #endif

  584. #if SQLITE_OMIT_FLOATING_POINT

  585.   "OMIT_FLOATING_POINT",

  586. #endif

  587. #if SQLITE_OMIT_FOREIGN_KEY

  588.   "OMIT_FOREIGN_KEY",

  589. #endif

  590. #if SQLITE_OMIT_GET_TABLE

  591.   "OMIT_GET_TABLE",

  592. #endif

  593. #if SQLITE_OMIT_HEX_INTEGER

  594.   "OMIT_HEX_INTEGER",

  595. #endif

  596. #if SQLITE_OMIT_INCRBLOB

  597.   "OMIT_INCRBLOB",

  598. #endif

  599. #if SQLITE_OMIT_INTEGRITY_CHECK

  600.   "OMIT_INTEGRITY_CHECK",

  601. #endif

  602. #if SQLITE_OMIT_LIKE_OPTIMIZATION

  603.   "OMIT_LIKE_OPTIMIZATION",

  604. #endif

  605. #if SQLITE_OMIT_LOAD_EXTENSION

  606.   "OMIT_LOAD_EXTENSION",

  607. #endif

  608. #if SQLITE_OMIT_LOCALTIME

  609.   "OMIT_LOCALTIME",

  610. #endif

  611. #if SQLITE_OMIT_LOOKASIDE

  612.   "OMIT_LOOKASIDE",

  613. #endif

  614. #if SQLITE_OMIT_MEMORYDB

  615.   "OMIT_MEMORYDB",

  616. #endif

  617. #if SQLITE_OMIT_OR_OPTIMIZATION

  618.   "OMIT_OR_OPTIMIZATION",

  619. #endif

  620. #if SQLITE_OMIT_PAGER_PRAGMAS

  621.   "OMIT_PAGER_PRAGMAS",

  622. #endif

  623. #if SQLITE_OMIT_PARSER_TRACE

  624.   "OMIT_PARSER_TRACE",

  625. #endif

  626. #if SQLITE_OMIT_POPEN

  627.   "OMIT_POPEN",

  628. #endif

  629. #if SQLITE_OMIT_PRAGMA

  630.   "OMIT_PRAGMA",

  631. #endif

  632. #if SQLITE_OMIT_PROGRESS_CALLBACK

  633.   "OMIT_PROGRESS_CALLBACK",

  634. #endif

  635. #if SQLITE_OMIT_QUICKBALANCE

  636.   "OMIT_QUICKBALANCE",

  637. #endif

  638. #if SQLITE_OMIT_REINDEX

  639.   "OMIT_REINDEX",

  640. #endif

  641. #if SQLITE_OMIT_SCHEMA_PRAGMAS

  642.   "OMIT_SCHEMA_PRAGMAS",

  643. #endif

  644. #if SQLITE_OMIT_SCHEMA_VERSION_PRAGMAS

  645.   "OMIT_SCHEMA_VERSION_PRAGMAS",

  646. #endif

  647. #if SQLITE_OMIT_SHARED_CACHE

  648.   "OMIT_SHARED_CACHE",

  649. #endif

  650. #if SQLITE_OMIT_SHUTDOWN_DIRECTORIES

  651.   "OMIT_SHUTDOWN_DIRECTORIES",

  652. #endif

  653. #if SQLITE_OMIT_SUBQUERY

  654.   "OMIT_SUBQUERY",

  655. #endif

  656. #if SQLITE_OMIT_TCL_VARIABLE

  657.   "OMIT_TCL_VARIABLE",

  658. #endif

  659. #if SQLITE_OMIT_TEMPDB

  660.   "OMIT_TEMPDB",

  661. #endif

  662. #if SQLITE_OMIT_TEST_CONTROL

  663.   "OMIT_TEST_CONTROL",

  664. #endif

  665. #if SQLITE_OMIT_TRACE

  666.   "OMIT_TRACE",

  667. #endif

  668. #if SQLITE_OMIT_TRIGGER

  669.   "OMIT_TRIGGER",

  670. #endif

  671. #if SQLITE_OMIT_TRUNCATE_OPTIMIZATION

  672.   "OMIT_TRUNCATE_OPTIMIZATION",

  673. #endif

  674. #if SQLITE_OMIT_UTF16

  675.   "OMIT_UTF16",

  676. #endif

  677. #if SQLITE_OMIT_VACUUM

  678.   "OMIT_VACUUM",

  679. #endif

  680. #if SQLITE_OMIT_VIEW

  681.   "OMIT_VIEW",

  682. #endif

  683. #if SQLITE_OMIT_VIRTUALTABLE

  684.   "OMIT_VIRTUALTABLE",

  685. #endif

  686. #if SQLITE_OMIT_WAL

  687.   "OMIT_WAL",

  688. #endif

  689. #if SQLITE_OMIT_WSD

  690.   "OMIT_WSD",

  691. #endif

  692. #if SQLITE_OMIT_XFER_OPT

  693.   "OMIT_XFER_OPT",

  694. #endif

  695. #if SQLITE_PCACHE_SEPARATE_HEADER

  696.   "PCACHE_SEPARATE_HEADER",

  697. #endif

  698. #if SQLITE_PERFORMANCE_TRACE

  699.   "PERFORMANCE_TRACE",

  700. #endif

  701. #if SQLITE_POWERSAFE_OVERWRITE

  702.   "POWERSAFE_OVERWRITE",

  703. #endif

  704. #if SQLITE_PREFER_PROXY_LOCKING

  705.   "PREFER_PROXY_LOCKING",

  706. #endif

  707. #if SQLITE_PROXY_DEBUG

  708.   "PROXY_DEBUG",

  709. #endif

  710. #if SQLITE_REVERSE_UNORDERED_SELECTS

  711.   "REVERSE_UNORDERED_SELECTS",

  712. #endif

  713. #if SQLITE_RTREE_INT_ONLY

  714.   "RTREE_INT_ONLY",

  715. #endif

  716. #if SQLITE_SECURE_DELETE

  717.   "SECURE_DELETE",

  718. #endif

  719. #if SQLITE_SMALL_STACK

  720.   "SMALL_STACK",

  721. #endif

  722. #ifdef SQLITE_SORTER_PMASZ

  723.   "SORTER_PMASZ=" CTIMEOPT_VAL(SQLITE_SORTER_PMASZ),

  724. #endif

  725. #if SQLITE_SOUNDEX

  726.   "SOUNDEX",

  727. #endif

  728. #ifdef SQLITE_STAT4_SAMPLES

  729.   "STAT4_SAMPLES=" CTIMEOPT_VAL(SQLITE_STAT4_SAMPLES),

  730. #endif

  731. #ifdef SQLITE_STMTJRNL_SPILL

  732.   "STMTJRNL_SPILL=" CTIMEOPT_VAL(SQLITE_STMTJRNL_SPILL),

  733. #endif

  734. #if SQLITE_SUBSTR_COMPATIBILITY

  735.   "SUBSTR_COMPATIBILITY",

  736. #endif

  737. #if SQLITE_SYSTEM_MALLOC

  738.   "SYSTEM_MALLOC",

  739. #endif

  740. #if SQLITE_TCL

  741.   "TCL",

  742. #endif

  743. #ifdef SQLITE_TEMP_STORE

  744.   "TEMP_STORE=" CTIMEOPT_VAL(SQLITE_TEMP_STORE),

  745. #endif

  746. #if SQLITE_TEST

  747.   "TEST",

  748. #endif

  749. #if defined(SQLITE_THREADSAFE)

  750.   "THREADSAFE=" CTIMEOPT_VAL(SQLITE_THREADSAFE),

  751. #elif defined(THREADSAFE)

  752.   "THREADSAFE=" CTIMEOPT_VAL(THREADSAFE),

  753. #else

  754.   "THREADSAFE=1",

  755. #endif

  756. #if SQLITE_UNLINK_AFTER_CLOSE

  757.   "UNLINK_AFTER_CLOSE",

  758. #endif

  759. #if SQLITE_UNTESTABLE

  760.   "UNTESTABLE",

  761. #endif

  762. #if SQLITE_USER_AUTHENTICATION

  763.   "USER_AUTHENTICATION",

  764. #endif

  765. #if SQLITE_USE_ALLOCA

  766.   "USE_ALLOCA",

  767. #endif

  768. #if SQLITE_USE_FCNTL_TRACE

  769.   "USE_FCNTL_TRACE",

  770. #endif

  771. #if SQLITE_USE_URI

  772.   "USE_URI",

  773. #endif

  774. #if SQLITE_VDBE_COVERAGE

  775.   "VDBE_COVERAGE",

  776. #endif

  777. #if SQLITE_WIN32_MALLOC

  778.   "WIN32_MALLOC",

  779. #endif

  780. #if SQLITE_ZERO_MALLOC

  781.   "ZERO_MALLOC",

  782. #endif

  783. /* 

  784. ** END CODE GENERATED BY tool/mkctime.tcl 

  785. */

  786. };

  787. 

  788. SQLITE_PRIVATE const char **sqlite3CompileOptions(int *pnOpt){

  789.   *pnOpt = sizeof(sqlite3azCompileOpt) / sizeof(sqlite3azCompileOpt[0]);

  790.   return (const char**)sqlite3azCompileOpt;

  791. }

  792. 

  793. #endif /* SQLITE_OMIT_COMPILEOPTION_DIAGS */

  794. 

  795. /************** End of ctime.c ***********************************************/

  796. /************** Begin file sqliteInt.h ***************************************/

  797. /*

  798. ** 2001 September 15

  799. **

  800. ** The author disclaims copyright to this source code.  In place of

  801. ** a legal notice, here is a blessing:

  802. **

  803. **    May you do good and not evil.

  804. **    May you find forgiveness for yourself and forgive others.

  805. **    May you share freely, never taking more than you give.

  806. **

  807. *************************************************************************

  808. ** Internal interface definitions for SQLite.

  809. **

  810. */

  811. #ifndef SQLITEINT_H

  812. #define SQLITEINT_H

  813. 

  814. /* Special Comments:

  815. **

  816. ** Some comments have special meaning to the tools that measure test

  817. ** coverage:

  818. **

  819. **    NO_TEST                     - The branches on this line are not

  820. **                                  measured by branch coverage.  This is

  821. **                                  used on lines of code that actually

  822. **                                  implement parts of coverage testing.

  823. **

  824. **    OPTIMIZATION-IF-TRUE        - This branch is allowed to alway be false

  825. **                                  and the correct answer is still obtained,

  826. **                                  though perhaps more slowly.

  827. **

  828. **    OPTIMIZATION-IF-FALSE       - This branch is allowed to alway be true

  829. **                                  and the correct answer is still obtained,

  830. **                                  though perhaps more slowly.

  831. **

  832. **    PREVENTS-HARMLESS-OVERREAD  - This branch prevents a buffer overread

  833. **                                  that would be harmless and undetectable

  834. **                                  if it did occur.  

  835. **

  836. ** In all cases, the special comment must be enclosed in the usual

  837. ** slash-asterisk...asterisk-slash comment marks, with no spaces between the 

  838. ** asterisks and the comment text.

  839. */

  840. 

  841. /*

  842. ** Make sure the Tcl calling convention macro is defined.  This macro is

  843. ** only used by test code and Tcl integration code.

  844. */

  845. #ifndef SQLITE_TCLAPI

  846. #  define SQLITE_TCLAPI

  847. #endif

  848. 

  849. /*

  850. ** Include the header file used to customize the compiler options for MSVC.

  851. ** This should be done first so that it can successfully prevent spurious

  852. ** compiler warnings due to subsequent content in this file and other files

  853. ** that are included by this file.

  854. */

  855. /************** Include msvc.h in the middle of sqliteInt.h ******************/

  856. /************** Begin file msvc.h ********************************************/

  857. /*

  858. ** 2015 January 12

  859. **

  860. ** The author disclaims copyright to this source code.  In place of

  861. ** a legal notice, here is a blessing:

  862. **

  863. **    May you do good and not evil.

  864. **    May you find forgiveness for yourself and forgive others.

  865. **    May you share freely, never taking more than you give.

  866. **

  867. ******************************************************************************

  868. **

  869. ** This file contains code that is specific to MSVC.

  870. */

  871. #ifndef SQLITE_MSVC_H

  872. #define SQLITE_MSVC_H

  873. 

  874. #if defined(_MSC_VER)

  875. #pragma warning(disable : 4054)

  876. #pragma warning(disable : 4055)

  877. #pragma warning(disable : 4100)

  878. #pragma warning(disable : 4127)

  879. #pragma warning(disable : 4130)

  880. #pragma warning(disable : 4152)

  881. #pragma warning(disable : 4189)

  882. #pragma warning(disable : 4206)

  883. #pragma warning(disable : 4210)

  884. #pragma warning(disable : 4232)

  885. #pragma warning(disable : 4244)

  886. #pragma warning(disable : 4305)

  887. #pragma warning(disable : 4306)

  888. #pragma warning(disable : 4702)

  889. #pragma warning(disable : 4706)

  890. #endif /* defined(_MSC_VER) */

  891. 

  892. #if defined(_MSC_VER) && !defined(_WIN64)

  893. #undef SQLITE_4_BYTE_ALIGNED_MALLOC

  894. #define SQLITE_4_BYTE_ALIGNED_MALLOC

  895. #endif /* defined(_MSC_VER) && !defined(_WIN64) */

  896. 

  897. #endif /* SQLITE_MSVC_H */

  898. 

  899. /************** End of msvc.h ************************************************/

  900. /************** Continuing where we left off in sqliteInt.h ******************/

  901. 

  902. /*

  903. ** Special setup for VxWorks

  904. */

  905. /************** Include vxworks.h in the middle of sqliteInt.h ***************/

  906. /************** Begin file vxworks.h *****************************************/

  907. /*

  908. ** 2015-03-02

  909. **

  910. ** The author disclaims copyright to this source code.  In place of

  911. ** a legal notice, here is a blessing:

  912. **

  913. **    May you do good and not evil.

  914. **    May you find forgiveness for yourself and forgive others.

  915. **    May you share freely, never taking more than you give.

  916. **

  917. ******************************************************************************

  918. **

  919. ** This file contains code that is specific to Wind River's VxWorks

  920. */

  921. #if defined(__RTP__) || defined(_WRS_KERNEL)

  922. /* This is VxWorks.  Set up things specially for that OS

  923. */

  924. #include <vxWorks.h>

  925. #include <pthread.h>  /* amalgamator: dontcache */

  926. #define OS_VXWORKS 1

  927. #define SQLITE_OS_OTHER 0

  928. #define SQLITE_HOMEGROWN_RECURSIVE_MUTEX 1

  929. #define SQLITE_OMIT_LOAD_EXTENSION 1

  930. #define SQLITE_ENABLE_LOCKING_STYLE 0

  931. #define HAVE_UTIME 1

  932. #else

  933. /* This is not VxWorks. */

  934. #define OS_VXWORKS 0

  935. #define HAVE_FCHOWN 1

  936. #define HAVE_READLINK 1

  937. #define HAVE_LSTAT 1

  938. #endif /* defined(_WRS_KERNEL) */

  939. 

  940. /************** End of vxworks.h *********************************************/

  941. /************** Continuing where we left off in sqliteInt.h ******************/

  942. 

  943. /*

  944. ** These #defines should enable >2GB file support on POSIX if the

  945. ** underlying operating system supports it.  If the OS lacks

  946. ** large file support, or if the OS is windows, these should be no-ops.

  947. **

  948. ** Ticket #2739:  The _LARGEFILE_SOURCE macro must appear before any

  949. ** system #includes.  Hence, this block of code must be the very first

  950. ** code in all source files.

  951. **

  952. ** Large file support can be disabled using the -DSQLITE_DISABLE_LFS switch

  953. ** on the compiler command line.  This is necessary if you are compiling

  954. ** on a recent machine (ex: Red Hat 7.2) but you want your code to work

  955. ** on an older machine (ex: Red Hat 6.0).  If you compile on Red Hat 7.2

  956. ** without this option, LFS is enable.  But LFS does not exist in the kernel

  957. ** in Red Hat 6.0, so the code won't work.  Hence, for maximum binary

  958. ** portability you should omit LFS.

  959. **

  960. ** The previous paragraph was written in 2005.  (This paragraph is written

  961. ** on 2008-11-28.) These days, all Linux kernels support large files, so

  962. ** you should probably leave LFS enabled.  But some embedded platforms might

  963. ** lack LFS in which case the SQLITE_DISABLE_LFS macro might still be useful.

  964. **

  965. ** Similar is true for Mac OS X.  LFS is only supported on Mac OS X 9 and later.

  966. */

  967. #ifndef SQLITE_DISABLE_LFS

  968. # define _LARGE_FILE       1

  969. # ifndef _FILE_OFFSET_BITS

  970. #   define _FILE_OFFSET_BITS 64

  971. # endif

  972. # define _LARGEFILE_SOURCE 1

  973. #endif

  974. 

  975. /* The GCC_VERSION and MSVC_VERSION macros are used to

  976. ** conditionally include optimizations for each of these compilers.  A

  977. ** value of 0 means that compiler is not being used.  The

  978. ** SQLITE_DISABLE_INTRINSIC macro means do not use any compiler-specific

  979. ** optimizations, and hence set all compiler macros to 0

  980. **

  981. ** There was once also a CLANG_VERSION macro.  However, we learn that the

  982. ** version numbers in clang are for "marketing" only and are inconsistent

  983. ** and unreliable.  Fortunately, all versions of clang also recognize the

  984. ** gcc version numbers and have reasonable settings for gcc version numbers,

  985. ** so the GCC_VERSION macro will be set to a correct non-zero value even

  986. ** when compiling with clang.

  987. */

  988. #if defined(__GNUC__) && !defined(SQLITE_DISABLE_INTRINSIC)

  989. # define GCC_VERSION (__GNUC__*1000000+__GNUC_MINOR__*1000+__GNUC_PATCHLEVEL__)

  990. #else

  991. # define GCC_VERSION 0

  992. #endif

  993. #if defined(_MSC_VER) && !defined(SQLITE_DISABLE_INTRINSIC)

  994. # define MSVC_VERSION _MSC_VER

  995. #else

  996. # define MSVC_VERSION 0

  997. #endif

  998. 

  999. /* Needed for various definitions... */

  1000. #if defined(__GNUC__) && !defined(_GNU_SOURCE)

  1001. # define _GNU_SOURCE

  1002. #endif

  1003. 

  1004. #if defined(__OpenBSD__) && !defined(_BSD_SOURCE)

  1005. # define _BSD_SOURCE

  1006. #endif

  1007. 

  1008. /*

  1009. ** For MinGW, check to see if we can include the header file containing its

  1010. ** version information, among other things.  Normally, this internal MinGW

  1011. ** header file would [only] be included automatically by other MinGW header

  1012. ** files; however, the contained version information is now required by this

  1013. ** header file to work around binary compatibility issues (see below) and

  1014. ** this is the only known way to reliably obtain it.  This entire #if block

  1015. ** would be completely unnecessary if there was any other way of detecting

  1016. ** MinGW via their preprocessor (e.g. if they customized their GCC to define

  1017. ** some MinGW-specific macros).  When compiling for MinGW, either the

  1018. ** _HAVE_MINGW_H or _HAVE__MINGW_H (note the extra underscore) macro must be

  1019. ** defined; otherwise, detection of conditions specific to MinGW will be

  1020. ** disabled.

  1021. */

  1022. #if defined(_HAVE_MINGW_H)

  1023. # include "mingw.h"

  1024. #elif defined(_HAVE__MINGW_H)

  1025. # include "_mingw.h"

  1026. #endif

  1027. 

  1028. /*

  1029. ** For MinGW version 4.x (and higher), check to see if the _USE_32BIT_TIME_T

  1030. ** define is required to maintain binary compatibility with the MSVC runtime

  1031. ** library in use (e.g. for Windows XP).

  1032. */

  1033. #if !defined(_USE_32BIT_TIME_T) && !defined(_USE_64BIT_TIME_T) && \

  1034.     defined(_WIN32) && !defined(_WIN64) && \

  1035.     defined(__MINGW_MAJOR_VERSION) && __MINGW_MAJOR_VERSION >= 4 && \

  1036.     defined(__MSVCRT__)

  1037. # define _USE_32BIT_TIME_T

  1038. #endif

  1039. 

  1040. /* The public SQLite interface.  The _FILE_OFFSET_BITS macro must appear

  1041. ** first in QNX.  Also, the _USE_32BIT_TIME_T macro must appear first for

  1042. ** MinGW.

  1043. */

  1044. /************** Include sqlite3.h in the middle of sqliteInt.h ***************/

  1045. /************** Begin file sqlite3.h *****************************************/

  1046. /*

  1047. ** 2001-09-15

  1048. **

  1049. ** The author disclaims copyright to this source code.  In place of

  1050. ** a legal notice, here is a blessing:

  1051. **

  1052. **    May you do good and not evil.

  1053. **    May you find forgiveness for yourself and forgive others.

  1054. **    May you share freely, never taking more than you give.

  1055. **

  1056. *************************************************************************

  1057. ** This header file defines the interface that the SQLite library

  1058. ** presents to client programs.  If a C-function, structure, datatype,

  1059. ** or constant definition does not appear in this file, then it is

  1060. ** not a published API of SQLite, is subject to change without

  1061. ** notice, and should not be referenced by programs that use SQLite.

  1062. **

  1063. ** Some of the definitions that are in this file are marked as

  1064. ** "experimental".  Experimental interfaces are normally new

  1065. ** features recently added to SQLite.  We do not anticipate changes

  1066. ** to experimental interfaces but reserve the right to make minor changes

  1067. ** if experience from use "in the wild" suggest such changes are prudent.

  1068. **

  1069. ** The official C-language API documentation for SQLite is derived

  1070. ** from comments in this file.  This file is the authoritative source

  1071. ** on how SQLite interfaces are supposed to operate.

  1072. **

  1073. ** The name of this file under configuration management is "sqlite.h.in".

  1074. ** The makefile makes some minor changes to this file (such as inserting

  1075. ** the version number) and changes its name to "sqlite3.h" as

  1076. ** part of the build process.

  1077. */

  1078. #ifndef SQLITE3_H

  1079. #define SQLITE3_H

  1080. #include <stdarg.h>     /* Needed for the definition of va_list */

  1081. 

  1082. /*

  1083. ** Make sure we can call this stuff from C++.

  1084. */

  1085. #if 0

  1086. extern "C" {

  1087. #endif

  1088. 

  1089. 

  1090. /*

  1091. ** Provide the ability to override linkage features of the interface.

  1092. */

  1093. #ifndef SQLITE_EXTERN

  1094. # define SQLITE_EXTERN extern

  1095. #endif

  1096. #ifndef SQLITE_API

  1097. # define SQLITE_API

  1098. #endif

  1099. #ifndef SQLITE_CDECL

  1100. # define SQLITE_CDECL

  1101. #endif

  1102. #ifndef SQLITE_APICALL

  1103. # define SQLITE_APICALL

  1104. #endif

  1105. #ifndef SQLITE_STDCALL

  1106. # define SQLITE_STDCALL SQLITE_APICALL

  1107. #endif

  1108. #ifndef SQLITE_CALLBACK

  1109. # define SQLITE_CALLBACK

  1110. #endif

  1111. #ifndef SQLITE_SYSAPI

  1112. # define SQLITE_SYSAPI

  1113. #endif

  1114. 

  1115. /*

  1116. ** These no-op macros are used in front of interfaces to mark those

  1117. ** interfaces as either deprecated or experimental.  New applications

  1118. ** should not use deprecated interfaces - they are supported for backwards

  1119. ** compatibility only.  Application writers should be aware that

  1120. ** experimental interfaces are subject to change in point releases.

  1121. **

  1122. ** These macros used to resolve to various kinds of compiler magic that

  1123. ** would generate warning messages when they were used.  But that

  1124. ** compiler magic ended up generating such a flurry of bug reports

  1125. ** that we have taken it all out and gone back to using simple

  1126. ** noop macros.

  1127. */

  1128. #define SQLITE_DEPRECATED

  1129. #define SQLITE_EXPERIMENTAL

  1130. 

  1131. /*

  1132. ** Ensure these symbols were not defined by some previous header file.

  1133. */

  1134. #ifdef SQLITE_VERSION

  1135. # undef SQLITE_VERSION

  1136. #endif

  1137. #ifdef SQLITE_VERSION_NUMBER

  1138. # undef SQLITE_VERSION_NUMBER

  1139. #endif

  1140. 

  1141. /*

  1142. ** CAPI3REF: Compile-Time Library Version Numbers

  1143. **

  1144. ** ^(The [SQLITE_VERSION] C preprocessor macro in the sqlite3.h header

  1145. ** evaluates to a string literal that is the SQLite version in the

  1146. ** format "X.Y.Z" where X is the major version number (always 3 for

  1147. ** SQLite3) and Y is the minor version number and Z is the release number.)^

  1148. ** ^(The [SQLITE_VERSION_NUMBER] C preprocessor macro resolves to an integer

  1149. ** with the value (X*1000000 + Y*1000 + Z) where X, Y, and Z are the same

  1150. ** numbers used in [SQLITE_VERSION].)^

  1151. ** The SQLITE_VERSION_NUMBER for any given release of SQLite will also

  1152. ** be larger than the release from which it is derived.  Either Y will

  1153. ** be held constant and Z will be incremented or else Y will be incremented

  1154. ** and Z will be reset to zero.

  1155. **

  1156. ** Since [version 3.6.18] ([dateof:3.6.18]), 

  1157. ** SQLite source code has been stored in the

  1158. ** <a href="http://www.fossil-scm.org/">Fossil configuration management

  1159. ** system</a>.  ^The SQLITE_SOURCE_ID macro evaluates to

  1160. ** a string which identifies a particular check-in of SQLite

  1161. ** within its configuration management system.  ^The SQLITE_SOURCE_ID

  1162. ** string contains the date and time of the check-in (UTC) and a SHA1

  1163. ** or SHA3-256 hash of the entire source tree.  If the source code has

  1164. ** been edited in any way since it was last checked in, then the last

  1165. ** four hexadecimal digits of the hash may be modified.

  1166. **

  1167. ** See also: [sqlite3_libversion()],

  1168. ** [sqlite3_libversion_number()], [sqlite3_sourceid()],

  1169. ** [sqlite_version()] and [sqlite_source_id()].

  1170. */

  1171. #define SQLITE_VERSION        "3.29.0"

  1172. #define SQLITE_VERSION_NUMBER 3029000

  1173. #define SQLITE_SOURCE_ID      "2019-07-10 17:32:03 fc82b73eaac8b36950e527f12c4b5dc1e147e6f4ad2217ae43ad82882a88bfa6"

  1174. 

  1175. /*

  1176. ** CAPI3REF: Run-Time Library Version Numbers

  1177. ** KEYWORDS: sqlite3_version sqlite3_sourceid

  1178. **

  1179. ** These interfaces provide the same information as the [SQLITE_VERSION],

  1180. ** [SQLITE_VERSION_NUMBER], and [SQLITE_SOURCE_ID] C preprocessor macros

  1181. ** but are associated with the library instead of the header file.  ^(Cautious

  1182. ** programmers might include assert() statements in their application to

  1183. ** verify that values returned by these interfaces match the macros in

  1184. ** the header, and thus ensure that the application is

  1185. ** compiled with matching library and header files.

  1186. **

  1187. ** <blockquote><pre>

  1188. ** assert( sqlite3_libversion_number()==SQLITE_VERSION_NUMBER );

  1189. ** assert( strncmp(sqlite3_sourceid(),SQLITE_SOURCE_ID,80)==0 );

  1190. ** assert( strcmp(sqlite3_libversion(),SQLITE_VERSION)==0 );

  1191. ** </pre></blockquote>)^

  1192. **

  1193. ** ^The sqlite3_version[] string constant contains the text of [SQLITE_VERSION]

  1194. ** macro.  ^The sqlite3_libversion() function returns a pointer to the

  1195. ** to the sqlite3_version[] string constant.  The sqlite3_libversion()

  1196. ** function is provided for use in DLLs since DLL users usually do not have

  1197. ** direct access to string constants within the DLL.  ^The

  1198. ** sqlite3_libversion_number() function returns an integer equal to

  1199. ** [SQLITE_VERSION_NUMBER].  ^(The sqlite3_sourceid() function returns 

  1200. ** a pointer to a string constant whose value is the same as the 

  1201. ** [SQLITE_SOURCE_ID] C preprocessor macro.  Except if SQLite is built

  1202. ** using an edited copy of [the amalgamation], then the last four characters

  1203. ** of the hash might be different from [SQLITE_SOURCE_ID].)^

  1204. **

  1205. ** See also: [sqlite_version()] and [sqlite_source_id()].

  1206. */

  1207. SQLITE_API const char sqlite3_version[] = SQLITE_VERSION;

  1208. SQLITE_API const char *sqlite3_libversion(void);

  1209. SQLITE_API const char *sqlite3_sourceid(void);

  1210. SQLITE_API int sqlite3_libversion_number(void);

  1211. 

  1212. /*

  1213. ** CAPI3REF: Run-Time Library Compilation Options Diagnostics

  1214. **

  1215. ** ^The sqlite3_compileoption_used() function returns 0 or 1 

  1216. ** indicating whether the specified option was defined at 

  1217. ** compile time.  ^The SQLITE_ prefix may be omitted from the 

  1218. ** option name passed to sqlite3_compileoption_used().  

  1219. **

  1220. ** ^The sqlite3_compileoption_get() function allows iterating

  1221. ** over the list of options that were defined at compile time by

  1222. ** returning the N-th compile time option string.  ^If N is out of range,

  1223. ** sqlite3_compileoption_get() returns a NULL pointer.  ^The SQLITE_ 

  1224. ** prefix is omitted from any strings returned by 

  1225. ** sqlite3_compileoption_get().

  1226. **

  1227. ** ^Support for the diagnostic functions sqlite3_compileoption_used()

  1228. ** and sqlite3_compileoption_get() may be omitted by specifying the 

  1229. ** [SQLITE_OMIT_COMPILEOPTION_DIAGS] option at compile time.

  1230. **

  1231. ** See also: SQL functions [sqlite_compileoption_used()] and

  1232. ** [sqlite_compileoption_get()] and the [compile_options pragma].

  1233. */

  1234. #ifndef SQLITE_OMIT_COMPILEOPTION_DIAGS

  1235. SQLITE_API int sqlite3_compileoption_used(const char *zOptName);

  1236. SQLITE_API const char *sqlite3_compileoption_get(int N);

  1237. #else

  1238. # define sqlite3_compileoption_used(X) 0

  1239. # define sqlite3_compileoption_get(X)  ((void*)0)

  1240. #endif

  1241. 

  1242. /*

  1243. ** CAPI3REF: Test To See If The Library Is Threadsafe

  1244. **

  1245. ** ^The sqlite3_threadsafe() function returns zero if and only if

  1246. ** SQLite was compiled with mutexing code omitted due to the

  1247. ** [SQLITE_THREADSAFE] compile-time option being set to 0.

  1248. **

  1249. ** SQLite can be compiled with or without mutexes.  When

  1250. ** the [SQLITE_THREADSAFE] C preprocessor macro is 1 or 2, mutexes

  1251. ** are enabled and SQLite is threadsafe.  When the

  1252. ** [SQLITE_THREADSAFE] macro is 0, 

  1253. ** the mutexes are omitted.  Without the mutexes, it is not safe

  1254. ** to use SQLite concurrently from more than one thread.

  1255. **

  1256. ** Enabling mutexes incurs a measurable performance penalty.

  1257. ** So if speed is of utmost importance, it makes sense to disable

  1258. ** the mutexes.  But for maximum safety, mutexes should be enabled.

  1259. ** ^The default behavior is for mutexes to be enabled.

  1260. **

  1261. ** This interface can be used by an application to make sure that the

  1262. ** version of SQLite that it is linking against was compiled with

  1263. ** the desired setting of the [SQLITE_THREADSAFE] macro.

  1264. **

  1265. ** This interface only reports on the compile-time mutex setting

  1266. ** of the [SQLITE_THREADSAFE] flag.  If SQLite is compiled with

  1267. ** SQLITE_THREADSAFE=1 or =2 then mutexes are enabled by default but

  1268. ** can be fully or partially disabled using a call to [sqlite3_config()]

  1269. ** with the verbs [SQLITE_CONFIG_SINGLETHREAD], [SQLITE_CONFIG_MULTITHREAD],

  1270. ** or [SQLITE_CONFIG_SERIALIZED].  ^(The return value of the

  1271. ** sqlite3_threadsafe() function shows only the compile-time setting of

  1272. ** thread safety, not any run-time changes to that setting made by

  1273. ** sqlite3_config(). In other words, the return value from sqlite3_threadsafe()

  1274. ** is unchanged by calls to sqlite3_config().)^

  1275. **

  1276. ** See the [threading mode] documentation for additional information.

  1277. */

  1278. SQLITE_API int sqlite3_threadsafe(void);

  1279. 

  1280. /*

  1281. ** CAPI3REF: Database Connection Handle

  1282. ** KEYWORDS: {database connection} {database connections}

  1283. **

  1284. ** Each open SQLite database is represented by a pointer to an instance of

  1285. ** the opaque structure named "sqlite3".  It is useful to think of an sqlite3

  1286. ** pointer as an object.  The [sqlite3_open()], [sqlite3_open16()], and

  1287. ** [sqlite3_open_v2()] interfaces are its constructors, and [sqlite3_close()]

  1288. ** and [sqlite3_close_v2()] are its destructors.  There are many other

  1289. ** interfaces (such as

  1290. ** [sqlite3_prepare_v2()], [sqlite3_create_function()], and

  1291. ** [sqlite3_busy_timeout()] to name but three) that are methods on an

  1292. ** sqlite3 object.

  1293. */

  1294. typedef struct sqlite3 sqlite3;

  1295. 

  1296. /*

  1297. ** CAPI3REF: 64-Bit Integer Types

  1298. ** KEYWORDS: sqlite_int64 sqlite_uint64

  1299. **

  1300. ** Because there is no cross-platform way to specify 64-bit integer types

  1301. ** SQLite includes typedefs for 64-bit signed and unsigned integers.

  1302. **

  1303. ** The sqlite3_int64 and sqlite3_uint64 are the preferred type definitions.

  1304. ** The sqlite_int64 and sqlite_uint64 types are supported for backwards

  1305. ** compatibility only.

  1306. **

  1307. ** ^The sqlite3_int64 and sqlite_int64 types can store integer values

  1308. ** between -9223372036854775808 and +9223372036854775807 inclusive.  ^The

  1309. ** sqlite3_uint64 and sqlite_uint64 types can store integer values 

  1310. ** between 0 and +18446744073709551615 inclusive.

  1311. */

  1312. #ifdef SQLITE_INT64_TYPE

  1313.   typedef SQLITE_INT64_TYPE sqlite_int64;

  1314. # ifdef SQLITE_UINT64_TYPE

  1315.     typedef SQLITE_UINT64_TYPE sqlite_uint64;

  1316. # else  

  1317.     typedef unsigned SQLITE_INT64_TYPE sqlite_uint64;

  1318. # endif

  1319. #elif defined(_MSC_VER) || defined(__BORLANDC__)

  1320.   typedef __int64 sqlite_int64;

  1321.   typedef unsigned __int64 sqlite_uint64;

  1322. #else

  1323.   typedef long long int sqlite_int64;

  1324.   typedef unsigned long long int sqlite_uint64;

  1325. #endif

  1326. typedef sqlite_int64 sqlite3_int64;

  1327. typedef sqlite_uint64 sqlite3_uint64;

  1328. 

  1329. /*

  1330. ** If compiling for a processor that lacks floating point support,

  1331. ** substitute integer for floating-point.

  1332. */

  1333. #ifdef SQLITE_OMIT_FLOATING_POINT

  1334. # define double sqlite3_int64

  1335. #endif

  1336. 

  1337. /*

  1338. ** CAPI3REF: Closing A Database Connection

  1339. ** DESTRUCTOR: sqlite3

  1340. **

  1341. ** ^The sqlite3_close() and sqlite3_close_v2() routines are destructors

  1342. ** for the [sqlite3] object.

  1343. ** ^Calls to sqlite3_close() and sqlite3_close_v2() return [SQLITE_OK] if

  1344. ** the [sqlite3] object is successfully destroyed and all associated

  1345. ** resources are deallocated.

  1346. **

  1347. ** ^If the database connection is associated with unfinalized prepared

  1348. ** statements or unfinished sqlite3_backup objects then sqlite3_close()

  1349. ** will leave the database connection open and return [SQLITE_BUSY].

  1350. ** ^If sqlite3_close_v2() is called with unfinalized prepared statements

  1351. ** and/or unfinished sqlite3_backups, then the database connection becomes

  1352. ** an unusable "zombie" which will automatically be deallocated when the

  1353. ** last prepared statement is finalized or the last sqlite3_backup is

  1354. ** finished.  The sqlite3_close_v2() interface is intended for use with

  1355. ** host languages that are garbage collected, and where the order in which

  1356. ** destructors are called is arbitrary.

  1357. **

  1358. ** Applications should [sqlite3_finalize | finalize] all [prepared statements],

  1359. ** [sqlite3_blob_close | close] all [BLOB handles], and 

  1360. ** [sqlite3_backup_finish | finish] all [sqlite3_backup] objects associated

  1361. ** with the [sqlite3] object prior to attempting to close the object.  ^If

  1362. ** sqlite3_close_v2() is called on a [database connection] that still has

  1363. ** outstanding [prepared statements], [BLOB handles], and/or

  1364. ** [sqlite3_backup] objects then it returns [SQLITE_OK] and the deallocation

  1365. ** of resources is deferred until all [prepared statements], [BLOB handles],

  1366. ** and [sqlite3_backup] objects are also destroyed.

  1367. **

  1368. ** ^If an [sqlite3] object is destroyed while a transaction is open,

  1369. ** the transaction is automatically rolled back.

  1370. **

  1371. ** The C parameter to [sqlite3_close(C)] and [sqlite3_close_v2(C)]

  1372. ** must be either a NULL

  1373. ** pointer or an [sqlite3] object pointer obtained

  1374. ** from [sqlite3_open()], [sqlite3_open16()], or

  1375. ** [sqlite3_open_v2()], and not previously closed.

  1376. ** ^Calling sqlite3_close() or sqlite3_close_v2() with a NULL pointer

  1377. ** argument is a harmless no-op.

  1378. */

  1379. SQLITE_API int sqlite3_close(sqlite3*);

  1380. SQLITE_API int sqlite3_close_v2(sqlite3*);

  1381. 

  1382. /*

  1383. ** The type for a callback function.

  1384. ** This is legacy and deprecated.  It is included for historical

  1385. ** compatibility and is not documented.

  1386. */

  1387. typedef int (*sqlite3_callback)(void*,int,char**, char**);

  1388. 

  1389. /*

  1390. ** CAPI3REF: One-Step Query Execution Interface

  1391. ** METHOD: sqlite3

  1392. **

  1393. ** The sqlite3_exec() interface is a convenience wrapper around

  1394. ** [sqlite3_prepare_v2()], [sqlite3_step()], and [sqlite3_finalize()],

  1395. ** that allows an application to run multiple statements of SQL

  1396. ** without having to use a lot of C code. 

  1397. **

  1398. ** ^The sqlite3_exec() interface runs zero or more UTF-8 encoded,

  1399. ** semicolon-separate SQL statements passed into its 2nd argument,

  1400. ** in the context of the [database connection] passed in as its 1st

  1401. ** argument.  ^If the callback function of the 3rd argument to

  1402. ** sqlite3_exec() is not NULL, then it is invoked for each result row

  1403. ** coming out of the evaluated SQL statements.  ^The 4th argument to

  1404. ** sqlite3_exec() is relayed through to the 1st argument of each

  1405. ** callback invocation.  ^If the callback pointer to sqlite3_exec()

  1406. ** is NULL, then no callback is ever invoked and result rows are

  1407. ** ignored.

  1408. **

  1409. ** ^If an error occurs while evaluating the SQL statements passed into

  1410. ** sqlite3_exec(), then execution of the current statement stops and

  1411. ** subsequent statements are skipped.  ^If the 5th parameter to sqlite3_exec()

  1412. ** is not NULL then any error message is written into memory obtained

  1413. ** from [sqlite3_malloc()] and passed back through the 5th parameter.

  1414. ** To avoid memory leaks, the application should invoke [sqlite3_free()]

  1415. ** on error message strings returned through the 5th parameter of

  1416. ** sqlite3_exec() after the error message string is no longer needed.

  1417. ** ^If the 5th parameter to sqlite3_exec() is not NULL and no errors

  1418. ** occur, then sqlite3_exec() sets the pointer in its 5th parameter to

  1419. ** NULL before returning.

  1420. **

  1421. ** ^If an sqlite3_exec() callback returns non-zero, the sqlite3_exec()

  1422. ** routine returns SQLITE_ABORT without invoking the callback again and

  1423. ** without running any subsequent SQL statements.

  1424. **

  1425. ** ^The 2nd argument to the sqlite3_exec() callback function is the

  1426. ** number of columns in the result.  ^The 3rd argument to the sqlite3_exec()

  1427. ** callback is an array of pointers to strings obtained as if from

  1428. ** [sqlite3_column_text()], one for each column.  ^If an element of a

  1429. ** result row is NULL then the corresponding string pointer for the

  1430. ** sqlite3_exec() callback is a NULL pointer.  ^The 4th argument to the

  1431. ** sqlite3_exec() callback is an array of pointers to strings where each

  1432. ** entry represents the name of corresponding result column as obtained

  1433. ** from [sqlite3_column_name()].

  1434. **

  1435. ** ^If the 2nd parameter to sqlite3_exec() is a NULL pointer, a pointer

  1436. ** to an empty string, or a pointer that contains only whitespace and/or 

  1437. ** SQL comments, then no SQL statements are evaluated and the database

  1438. ** is not changed.

  1439. **

  1440. ** Restrictions:

  1441. **

  1442. ** <ul>

  1443. ** <li> The application must ensure that the 1st parameter to sqlite3_exec()

  1444. **      is a valid and open [database connection].

  1445. ** <li> The application must not close the [database connection] specified by

  1446. **      the 1st parameter to sqlite3_exec() while sqlite3_exec() is running.

  1447. ** <li> The application must not modify the SQL statement text passed into

  1448. **      the 2nd parameter of sqlite3_exec() while sqlite3_exec() is running.

  1449. ** </ul>

  1450. */

  1451. SQLITE_API int sqlite3_exec(

  1452.   sqlite3*,                                  /* An open database */

  1453.   const char *sql,                           /* SQL to be evaluated */

  1454.   int (*callback)(void*,int,char**,char**),  /* Callback function */

  1455.   void *,                                    /* 1st argument to callback */

  1456.   char **errmsg                              /* Error msg written here */

  1457. );

  1458. 

  1459. /*

  1460. ** CAPI3REF: Result Codes

  1461. ** KEYWORDS: {result code definitions}

  1462. **

  1463. ** Many SQLite functions return an integer result code from the set shown

  1464. ** here in order to indicate success or failure.

  1465. **

  1466. ** New error codes may be added in future versions of SQLite.

  1467. **

  1468. ** See also: [extended result code definitions]

  1469. */

  1470. #define SQLITE_OK           0   /* Successful result */

  1471. /* beginning-of-error-codes */

  1472. #define SQLITE_ERROR        1   /* Generic error */

  1473. #define SQLITE_INTERNAL     2   /* Internal logic error in SQLite */

  1474. #define SQLITE_PERM         3   /* Access permission denied */

  1475. #define SQLITE_ABORT        4   /* Callback routine requested an abort */

  1476. #define SQLITE_BUSY         5   /* The database file is locked */

  1477. #define SQLITE_LOCKED       6   /* A table in the database is locked */

  1478. #define SQLITE_NOMEM        7   /* A malloc() failed */

  1479. #define SQLITE_READONLY     8   /* Attempt to write a readonly database */

  1480. #define SQLITE_INTERRUPT    9   /* Operation terminated by sqlite3_interrupt()*/

  1481. #define SQLITE_IOERR       10   /* Some kind of disk I/O error occurred */

  1482. #define SQLITE_CORRUPT     11   /* The database disk image is malformed */

  1483. #define SQLITE_NOTFOUND    12   /* Unknown opcode in sqlite3_file_control() */

  1484. #define SQLITE_FULL        13   /* Insertion failed because database is full */

  1485. #define SQLITE_CANTOPEN    14   /* Unable to open the database file */

  1486. #define SQLITE_PROTOCOL    15   /* Database lock protocol error */

  1487. #define SQLITE_EMPTY       16   /* Internal use only */

  1488. #define SQLITE_SCHEMA      17   /* The database schema changed */

  1489. #define SQLITE_TOOBIG      18   /* String or BLOB exceeds size limit */

  1490. #define SQLITE_CONSTRAINT  19   /* Abort due to constraint violation */

  1491. #define SQLITE_MISMATCH    20   /* Data type mismatch */

  1492. #define SQLITE_MISUSE      21   /* Library used incorrectly */

  1493. #define SQLITE_NOLFS       22   /* Uses OS features not supported on host */

  1494. #define SQLITE_AUTH        23   /* Authorization denied */

  1495. #define SQLITE_FORMAT      24   /* Not used */

  1496. #define SQLITE_RANGE       25   /* 2nd parameter to sqlite3_bind out of range */

  1497. #define SQLITE_NOTADB      26   /* File opened that is not a database file */

  1498. #define SQLITE_NOTICE      27   /* Notifications from sqlite3_log() */

  1499. #define SQLITE_WARNING     28   /* Warnings from sqlite3_log() */

  1500. #define SQLITE_ROW         100  /* sqlite3_step() has another row ready */

  1501. #define SQLITE_DONE        101  /* sqlite3_step() has finished executing */

  1502. /* end-of-error-codes */

  1503. 

  1504. /*

  1505. ** CAPI3REF: Extended Result Codes

  1506. ** KEYWORDS: {extended result code definitions}

  1507. **

  1508. ** In its default configuration, SQLite API routines return one of 30 integer

  1509. ** [result codes].  However, experience has shown that many of

  1510. ** these result codes are too coarse-grained.  They do not provide as

  1511. ** much information about problems as programmers might like.  In an effort to

  1512. ** address this, newer versions of SQLite (version 3.3.8 [dateof:3.3.8]

  1513. ** and later) include

  1514. ** support for additional result codes that provide more detailed information

  1515. ** about errors. These [extended result codes] are enabled or disabled

  1516. ** on a per database connection basis using the

  1517. ** [sqlite3_extended_result_codes()] API.  Or, the extended code for

  1518. ** the most recent error can be obtained using

  1519. ** [sqlite3_extended_errcode()].

  1520. */

  1521. #define SQLITE_ERROR_MISSING_COLLSEQ   (SQLITE_ERROR | (1<<8))

  1522. #define SQLITE_ERROR_RETRY             (SQLITE_ERROR | (2<<8))

  1523. #define SQLITE_ERROR_SNAPSHOT          (SQLITE_ERROR | (3<<8))

  1524. #define SQLITE_IOERR_READ              (SQLITE_IOERR | (1<<8))

  1525. #define SQLITE_IOERR_SHORT_READ        (SQLITE_IOERR | (2<<8))

  1526. #define SQLITE_IOERR_WRITE             (SQLITE_IOERR | (3<<8))

  1527. #define SQLITE_IOERR_FSYNC             (SQLITE_IOERR | (4<<8))

  1528. #define SQLITE_IOERR_DIR_FSYNC         (SQLITE_IOERR | (5<<8))

  1529. #define SQLITE_IOERR_TRUNCATE          (SQLITE_IOERR | (6<<8))

  1530. #define SQLITE_IOERR_FSTAT             (SQLITE_IOERR | (7<<8))

  1531. #define SQLITE_IOERR_UNLOCK            (SQLITE_IOERR | (8<<8))

  1532. #define SQLITE_IOERR_RDLOCK            (SQLITE_IOERR | (9<<8))

  1533. #define SQLITE_IOERR_DELETE            (SQLITE_IOERR | (10<<8))

  1534. #define SQLITE_IOERR_BLOCKED           (SQLITE_IOERR | (11<<8))

  1535. #define SQLITE_IOERR_NOMEM             (SQLITE_IOERR | (12<<8))

  1536. #define SQLITE_IOERR_ACCESS            (SQLITE_IOERR | (13<<8))

  1537. #define SQLITE_IOERR_CHECKRESERVEDLOCK (SQLITE_IOERR | (14<<8))

  1538. #define SQLITE_IOERR_LOCK              (SQLITE_IOERR | (15<<8))

  1539. #define SQLITE_IOERR_CLOSE             (SQLITE_IOERR | (16<<8))

  1540. #define SQLITE_IOERR_DIR_CLOSE         (SQLITE_IOERR | (17<<8))

  1541. #define SQLITE_IOERR_SHMOPEN           (SQLITE_IOERR | (18<<8))

  1542. #define SQLITE_IOERR_SHMSIZE           (SQLITE_IOERR | (19<<8))

  1543. #define SQLITE_IOERR_SHMLOCK           (SQLITE_IOERR | (20<<8))

  1544. #define SQLITE_IOERR_SHMMAP            (SQLITE_IOERR | (21<<8))

  1545. #define SQLITE_IOERR_SEEK              (SQLITE_IOERR | (22<<8))

  1546. #define SQLITE_IOERR_DELETE_NOENT      (SQLITE_IOERR | (23<<8))

  1547. #define SQLITE_IOERR_MMAP              (SQLITE_IOERR | (24<<8))

  1548. #define SQLITE_IOERR_GETTEMPPATH       (SQLITE_IOERR | (25<<8))

  1549. #define SQLITE_IOERR_CONVPATH          (SQLITE_IOERR | (26<<8))

  1550. #define SQLITE_IOERR_VNODE             (SQLITE_IOERR | (27<<8))

  1551. #define SQLITE_IOERR_AUTH              (SQLITE_IOERR | (28<<8))

  1552. #define SQLITE_IOERR_BEGIN_ATOMIC      (SQLITE_IOERR | (29<<8))

  1553. #define SQLITE_IOERR_COMMIT_ATOMIC     (SQLITE_IOERR | (30<<8))

  1554. #define SQLITE_IOERR_ROLLBACK_ATOMIC   (SQLITE_IOERR | (31<<8))

  1555. #define SQLITE_LOCKED_SHAREDCACHE      (SQLITE_LOCKED |  (1<<8))

  1556. #define SQLITE_LOCKED_VTAB             (SQLITE_LOCKED |  (2<<8))

  1557. #define SQLITE_BUSY_RECOVERY           (SQLITE_BUSY   |  (1<<8))

  1558. #define SQLITE_BUSY_SNAPSHOT           (SQLITE_BUSY   |  (2<<8))

  1559. #define SQLITE_CANTOPEN_NOTEMPDIR      (SQLITE_CANTOPEN | (1<<8))

  1560. #define SQLITE_CANTOPEN_ISDIR          (SQLITE_CANTOPEN | (2<<8))

  1561. #define SQLITE_CANTOPEN_FULLPATH       (SQLITE_CANTOPEN | (3<<8))

  1562. #define SQLITE_CANTOPEN_CONVPATH       (SQLITE_CANTOPEN | (4<<8))

  1563. #define SQLITE_CANTOPEN_DIRTYWAL       (SQLITE_CANTOPEN | (5<<8)) /* Not Used */

  1564. #define SQLITE_CORRUPT_VTAB            (SQLITE_CORRUPT | (1<<8))

  1565. #define SQLITE_CORRUPT_SEQUENCE        (SQLITE_CORRUPT | (2<<8))

  1566. #define SQLITE_READONLY_RECOVERY       (SQLITE_READONLY | (1<<8))

  1567. #define SQLITE_READONLY_CANTLOCK       (SQLITE_READONLY | (2<<8))

  1568. #define SQLITE_READONLY_ROLLBACK       (SQLITE_READONLY | (3<<8))

  1569. #define SQLITE_READONLY_DBMOVED        (SQLITE_READONLY | (4<<8))

  1570. #define SQLITE_READONLY_CANTINIT       (SQLITE_READONLY | (5<<8))

  1571. #define SQLITE_READONLY_DIRECTORY      (SQLITE_READONLY | (6<<8))

  1572. #define SQLITE_ABORT_ROLLBACK          (SQLITE_ABORT | (2<<8))

  1573. #define SQLITE_CONSTRAINT_CHECK        (SQLITE_CONSTRAINT | (1<<8))

  1574. #define SQLITE_CONSTRAINT_COMMITHOOK   (SQLITE_CONSTRAINT | (2<<8))

  1575. #define SQLITE_CONSTRAINT_FOREIGNKEY   (SQLITE_CONSTRAINT | (3<<8))

  1576. #define SQLITE_CONSTRAINT_FUNCTION     (SQLITE_CONSTRAINT | (4<<8))

  1577. #define SQLITE_CONSTRAINT_NOTNULL      (SQLITE_CONSTRAINT | (5<<8))

  1578. #define SQLITE_CONSTRAINT_PRIMARYKEY   (SQLITE_CONSTRAINT | (6<<8))

  1579. #define SQLITE_CONSTRAINT_TRIGGER      (SQLITE_CONSTRAINT | (7<<8))

  1580. #define SQLITE_CONSTRAINT_UNIQUE       (SQLITE_CONSTRAINT | (8<<8))

  1581. #define SQLITE_CONSTRAINT_VTAB         (SQLITE_CONSTRAINT | (9<<8))

  1582. #define SQLITE_CONSTRAINT_ROWID        (SQLITE_CONSTRAINT |(10<<8))

  1583. #define SQLITE_NOTICE_RECOVER_WAL      (SQLITE_NOTICE | (1<<8))

  1584. #define SQLITE_NOTICE_RECOVER_ROLLBACK (SQLITE_NOTICE | (2<<8))

  1585. #define SQLITE_WARNING_AUTOINDEX       (SQLITE_WARNING | (1<<8))

  1586. #define SQLITE_AUTH_USER               (SQLITE_AUTH | (1<<8))

  1587. #define SQLITE_OK_LOAD_PERMANENTLY     (SQLITE_OK | (1<<8))

  1588. 

  1589. /*

  1590. ** CAPI3REF: Flags For File Open Operations

  1591. **

  1592. ** These bit values are intended for use in the

  1593. ** 3rd parameter to the [sqlite3_open_v2()] interface and

  1594. ** in the 4th parameter to the [sqlite3_vfs.xOpen] method.

  1595. */

  1596. #define SQLITE_OPEN_READONLY         0x00000001  /* Ok for sqlite3_open_v2() */

  1597. #define SQLITE_OPEN_READWRITE        0x00000002  /* Ok for sqlite3_open_v2() */

  1598. #define SQLITE_OPEN_CREATE           0x00000004  /* Ok for sqlite3_open_v2() */

  1599. #define SQLITE_OPEN_DELETEONCLOSE    0x00000008  /* VFS only */

  1600. #define SQLITE_OPEN_EXCLUSIVE        0x00000010  /* VFS only */

  1601. #define SQLITE_OPEN_AUTOPROXY        0x00000020  /* VFS only */

  1602. #define SQLITE_OPEN_URI              0x00000040  /* Ok for sqlite3_open_v2() */

  1603. #define SQLITE_OPEN_MEMORY           0x00000080  /* Ok for sqlite3_open_v2() */

  1604. #define SQLITE_OPEN_MAIN_DB          0x00000100  /* VFS only */

  1605. #define SQLITE_OPEN_TEMP_DB          0x00000200  /* VFS only */

  1606. #define SQLITE_OPEN_TRANSIENT_DB     0x00000400  /* VFS only */

  1607. #define SQLITE_OPEN_MAIN_JOURNAL     0x00000800  /* VFS only */

  1608. #define SQLITE_OPEN_TEMP_JOURNAL     0x00001000  /* VFS only */

  1609. #define SQLITE_OPEN_SUBJOURNAL       0x00002000  /* VFS only */

  1610. #define SQLITE_OPEN_MASTER_JOURNAL   0x00004000  /* VFS only */

  1611. #define SQLITE_OPEN_NOMUTEX          0x00008000  /* Ok for sqlite3_open_v2() */

  1612. #define SQLITE_OPEN_FULLMUTEX        0x00010000  /* Ok for sqlite3_open_v2() */

  1613. #define SQLITE_OPEN_SHAREDCACHE      0x00020000  /* Ok for sqlite3_open_v2() */

  1614. #define SQLITE_OPEN_PRIVATECACHE     0x00040000  /* Ok for sqlite3_open_v2() */

  1615. #define SQLITE_OPEN_WAL              0x00080000  /* VFS only */

  1616. 

  1617. /* Reserved:                         0x00F00000 */

  1618. 

  1619. /*

  1620. ** CAPI3REF: Device Characteristics

  1621. **

  1622. ** The xDeviceCharacteristics method of the [sqlite3_io_methods]

  1623. ** object returns an integer which is a vector of these

  1624. ** bit values expressing I/O characteristics of the mass storage

  1625. ** device that holds the file that the [sqlite3_io_methods]

  1626. ** refers to.

  1627. **

  1628. ** The SQLITE_IOCAP_ATOMIC property means that all writes of

  1629. ** any size are atomic.  The SQLITE_IOCAP_ATOMICnnn values

  1630. ** mean that writes of blocks that are nnn bytes in size and

  1631. ** are aligned to an address which is an integer multiple of

  1632. ** nnn are atomic.  The SQLITE_IOCAP_SAFE_APPEND value means

  1633. ** that when data is appended to a file, the data is appended

  1634. ** first then the size of the file is extended, never the other

  1635. ** way around.  The SQLITE_IOCAP_SEQUENTIAL property means that

  1636. ** information is written to disk in the same order as calls

  1637. ** to xWrite().  The SQLITE_IOCAP_POWERSAFE_OVERWRITE property means that

  1638. ** after reboot following a crash or power loss, the only bytes in a

  1639. ** file that were written at the application level might have changed

  1640. ** and that adjacent bytes, even bytes within the same sector are

  1641. ** guaranteed to be unchanged.  The SQLITE_IOCAP_UNDELETABLE_WHEN_OPEN

  1642. ** flag indicates that a file cannot be deleted when open.  The

  1643. ** SQLITE_IOCAP_IMMUTABLE flag indicates that the file is on

  1644. ** read-only media and cannot be changed even by processes with

  1645. ** elevated privileges.

  1646. **

  1647. ** The SQLITE_IOCAP_BATCH_ATOMIC property means that the underlying

  1648. ** filesystem supports doing multiple write operations atomically when those

  1649. ** write operations are bracketed by [SQLITE_FCNTL_BEGIN_ATOMIC_WRITE] and

  1650. ** [SQLITE_FCNTL_COMMIT_ATOMIC_WRITE].

  1651. */

  1652. #define SQLITE_IOCAP_ATOMIC                 0x00000001

  1653. #define SQLITE_IOCAP_ATOMIC512              0x00000002

  1654. #define SQLITE_IOCAP_ATOMIC1K               0x00000004

  1655. #define SQLITE_IOCAP_ATOMIC2K               0x00000008

  1656. #define SQLITE_IOCAP_ATOMIC4K               0x00000010

  1657. #define SQLITE_IOCAP_ATOMIC8K               0x00000020

  1658. #define SQLITE_IOCAP_ATOMIC16K              0x00000040

  1659. #define SQLITE_IOCAP_ATOMIC32K              0x00000080

  1660. #define SQLITE_IOCAP_ATOMIC64K              0x00000100

  1661. #define SQLITE_IOCAP_SAFE_APPEND            0x00000200

  1662. #define SQLITE_IOCAP_SEQUENTIAL             0x00000400

  1663. #define SQLITE_IOCAP_UNDELETABLE_WHEN_OPEN  0x00000800

  1664. #define SQLITE_IOCAP_POWERSAFE_OVERWRITE    0x00001000

  1665. #define SQLITE_IOCAP_IMMUTABLE              0x00002000

  1666. #define SQLITE_IOCAP_BATCH_ATOMIC           0x00004000

  1667. 

  1668. /*

  1669. ** CAPI3REF: File Locking Levels

  1670. **

  1671. ** SQLite uses one of these integer values as the second

  1672. ** argument to calls it makes to the xLock() and xUnlock() methods

  1673. ** of an [sqlite3_io_methods] object.

  1674. */

  1675. #define SQLITE_LOCK_NONE          0

  1676. #define SQLITE_LOCK_SHARED        1

  1677. #define SQLITE_LOCK_RESERVED      2

  1678. #define SQLITE_LOCK_PENDING       3

  1679. #define SQLITE_LOCK_EXCLUSIVE     4

  1680. 

  1681. /*

  1682. ** CAPI3REF: Synchronization Type Flags

  1683. **

  1684. ** When SQLite invokes the xSync() method of an

  1685. ** [sqlite3_io_methods] object it uses a combination of

  1686. ** these integer values as the second argument.

  1687. **

  1688. ** When the SQLITE_SYNC_DATAONLY flag is used, it means that the

  1689. ** sync operation only needs to flush data to mass storage.  Inode

  1690. ** information need not be flushed. If the lower four bits of the flag

  1691. ** equal SQLITE_SYNC_NORMAL, that means to use normal fsync() semantics.

  1692. ** If the lower four bits equal SQLITE_SYNC_FULL, that means

  1693. ** to use Mac OS X style fullsync instead of fsync().

  1694. **

  1695. ** Do not confuse the SQLITE_SYNC_NORMAL and SQLITE_SYNC_FULL flags

  1696. ** with the [PRAGMA synchronous]=NORMAL and [PRAGMA synchronous]=FULL

  1697. ** settings.  The [synchronous pragma] determines when calls to the

  1698. ** xSync VFS method occur and applies uniformly across all platforms.

  1699. ** The SQLITE_SYNC_NORMAL and SQLITE_SYNC_FULL flags determine how

  1700. ** energetic or rigorous or forceful the sync operations are and

  1701. ** only make a difference on Mac OSX for the default SQLite code.

  1702. ** (Third-party VFS implementations might also make the distinction

  1703. ** between SQLITE_SYNC_NORMAL and SQLITE_SYNC_FULL, but among the

  1704. ** operating systems natively supported by SQLite, only Mac OSX

  1705. ** cares about the difference.)

  1706. */

  1707. #define SQLITE_SYNC_NORMAL        0x00002

  1708. #define SQLITE_SYNC_FULL          0x00003

  1709. #define SQLITE_SYNC_DATAONLY      0x00010

  1710. 

  1711. /*

  1712. ** CAPI3REF: OS Interface Open File Handle

  1713. **

  1714. ** An [sqlite3_file] object represents an open file in the 

  1715. ** [sqlite3_vfs | OS interface layer].  Individual OS interface

  1716. ** implementations will

  1717. ** want to subclass this object by appending additional fields

  1718. ** for their own use.  The pMethods entry is a pointer to an

  1719. ** [sqlite3_io_methods] object that defines methods for performing

  1720. ** I/O operations on the open file.

  1721. */

  1722. typedef struct sqlite3_file sqlite3_file;

  1723. struct sqlite3_file {

  1724.   const struct sqlite3_io_methods *pMethods;  /* Methods for an open file */

  1725. };

  1726. 

  1727. /*

  1728. ** CAPI3REF: OS Interface File Virtual Methods Object

  1729. **

  1730. ** Every file opened by the [sqlite3_vfs.xOpen] method populates an

  1731. ** [sqlite3_file] object (or, more commonly, a subclass of the

  1732. ** [sqlite3_file] object) with a pointer to an instance of this object.

  1733. ** This object defines the methods used to perform various operations

  1734. ** against the open file represented by the [sqlite3_file] object.

  1735. **

  1736. ** If the [sqlite3_vfs.xOpen] method sets the sqlite3_file.pMethods element 

  1737. ** to a non-NULL pointer, then the sqlite3_io_methods.xClose method

  1738. ** may be invoked even if the [sqlite3_vfs.xOpen] reported that it failed.  The

  1739. ** only way to prevent a call to xClose following a failed [sqlite3_vfs.xOpen]

  1740. ** is for the [sqlite3_vfs.xOpen] to set the sqlite3_file.pMethods element

  1741. ** to NULL.

  1742. **

  1743. ** The flags argument to xSync may be one of [SQLITE_SYNC_NORMAL] or

  1744. ** [SQLITE_SYNC_FULL].  The first choice is the normal fsync().

  1745. ** The second choice is a Mac OS X style fullsync.  The [SQLITE_SYNC_DATAONLY]

  1746. ** flag may be ORed in to indicate that only the data of the file

  1747. ** and not its inode needs to be synced.

  1748. **

  1749. ** The integer values to xLock() and xUnlock() are one of

  1750. ** <ul>

  1751. ** <li> [SQLITE_LOCK_NONE],

  1752. ** <li> [SQLITE_LOCK_SHARED],

  1753. ** <li> [SQLITE_LOCK_RESERVED],

  1754. ** <li> [SQLITE_LOCK_PENDING], or

  1755. ** <li> [SQLITE_LOCK_EXCLUSIVE].

  1756. ** </ul>

  1757. ** xLock() increases the lock. xUnlock() decreases the lock.

  1758. ** The xCheckReservedLock() method checks whether any database connection,

  1759. ** either in this process or in some other process, is holding a RESERVED,

  1760. ** PENDING, or EXCLUSIVE lock on the file.  It returns true

  1761. ** if such a lock exists and false otherwise.

  1762. **

  1763. ** The xFileControl() method is a generic interface that allows custom

  1764. ** VFS implementations to directly control an open file using the

  1765. ** [sqlite3_file_control()] interface.  The second "op" argument is an

  1766. ** integer opcode.  The third argument is a generic pointer intended to

  1767. ** point to a structure that may contain arguments or space in which to

  1768. ** write return values.  Potential uses for xFileControl() might be

  1769. ** functions to enable blocking locks with timeouts, to change the

  1770. ** locking strategy (for example to use dot-file locks), to inquire

  1771. ** about the status of a lock, or to break stale locks.  The SQLite

  1772. ** core reserves all opcodes less than 100 for its own use.

  1773. ** A [file control opcodes | list of opcodes] less than 100 is available.

  1774. ** Applications that define a custom xFileControl method should use opcodes

  1775. ** greater than 100 to avoid conflicts.  VFS implementations should

  1776. ** return [SQLITE_NOTFOUND] for file control opcodes that they do not

  1777. ** recognize.

  1778. **

  1779. ** The xSectorSize() method returns the sector size of the

  1780. ** device that underlies the file.  The sector size is the

  1781. ** minimum write that can be performed without disturbing

  1782. ** other bytes in the file.  The xDeviceCharacteristics()

  1783. ** method returns a bit vector describing behaviors of the

  1784. ** underlying device:

  1785. **

  1786. ** <ul>

  1787. ** <li> [SQLITE_IOCAP_ATOMIC]

  1788. ** <li> [SQLITE_IOCAP_ATOMIC512]

  1789. ** <li> [SQLITE_IOCAP_ATOMIC1K]

  1790. ** <li> [SQLITE_IOCAP_ATOMIC2K]

  1791. ** <li> [SQLITE_IOCAP_ATOMIC4K]

  1792. ** <li> [SQLITE_IOCAP_ATOMIC8K]

  1793. ** <li> [SQLITE_IOCAP_ATOMIC16K]

  1794. ** <li> [SQLITE_IOCAP_ATOMIC32K]

  1795. ** <li> [SQLITE_IOCAP_ATOMIC64K]

  1796. ** <li> [SQLITE_IOCAP_SAFE_APPEND]

  1797. ** <li> [SQLITE_IOCAP_SEQUENTIAL]

  1798. ** <li> [SQLITE_IOCAP_UNDELETABLE_WHEN_OPEN]

  1799. ** <li> [SQLITE_IOCAP_POWERSAFE_OVERWRITE]

  1800. ** <li> [SQLITE_IOCAP_IMMUTABLE]

  1801. ** <li> [SQLITE_IOCAP_BATCH_ATOMIC]

  1802. ** </ul>

  1803. **

  1804. ** The SQLITE_IOCAP_ATOMIC property means that all writes of

  1805. ** any size are atomic.  The SQLITE_IOCAP_ATOMICnnn values

  1806. ** mean that writes of blocks that are nnn bytes in size and

  1807. ** are aligned to an address which is an integer multiple of

  1808. ** nnn are atomic.  The SQLITE_IOCAP_SAFE_APPEND value means

  1809. ** that when data is appended to a file, the data is appended

  1810. ** first then the size of the file is extended, never the other

  1811. ** way around.  The SQLITE_IOCAP_SEQUENTIAL property means that

  1812. ** information is written to disk in the same order as calls

  1813. ** to xWrite().

  1814. **

  1815. ** If xRead() returns SQLITE_IOERR_SHORT_READ it must also fill

  1816. ** in the unread portions of the buffer with zeros.  A VFS that

  1817. ** fails to zero-fill short reads might seem to work.  However,

  1818. ** failure to zero-fill short reads will eventually lead to

  1819. ** database corruption.

  1820. */

  1821. typedef struct sqlite3_io_methods sqlite3_io_methods;

  1822. struct sqlite3_io_methods {

  1823.   int iVersion;

  1824.   int (*xClose)(sqlite3_file*);

  1825.   int (*xRead)(sqlite3_file*, void*, int iAmt, sqlite3_int64 iOfst);

  1826.   int (*xWrite)(sqlite3_file*, const void*, int iAmt, sqlite3_int64 iOfst);

  1827.   int (*xTruncate)(sqlite3_file*, sqlite3_int64 size);

  1828.   int (*xSync)(sqlite3_file*, int flags);

  1829.   int (*xFileSize)(sqlite3_file*, sqlite3_int64 *pSize);

  1830.   int (*xLock)(sqlite3_file*, int);

  1831.   int (*xUnlock)(sqlite3_file*, int);

  1832.   int (*xCheckReservedLock)(sqlite3_file*, int *pResOut);

  1833.   int (*xFileControl)(sqlite3_file*, int op, void *pArg);

  1834.   int (*xSectorSize)(sqlite3_file*);

  1835.   int (*xDeviceCharacteristics)(sqlite3_file*);

  1836.   /* Methods above are valid for version 1 */

  1837.   int (*xShmMap)(sqlite3_file*, int iPg, int pgsz, int, void volatile**);

  1838.   int (*xShmLock)(sqlite3_file*, int offset, int n, int flags);

  1839.   void (*xShmBarrier)(sqlite3_file*);

  1840.   int (*xShmUnmap)(sqlite3_file*, int deleteFlag);

  1841.   /* Methods above are valid for version 2 */

  1842.   int (*xFetch)(sqlite3_file*, sqlite3_int64 iOfst, int iAmt, void **pp);

  1843.   int (*xUnfetch)(sqlite3_file*, sqlite3_int64 iOfst, void *p);

  1844.   /* Methods above are valid for version 3 */

  1845.   /* Additional methods may be added in future releases */

  1846. };

  1847. 

  1848. /*

  1849. ** CAPI3REF: Standard File Control Opcodes

  1850. ** KEYWORDS: {file control opcodes} {file control opcode}

  1851. **

  1852. ** These integer constants are opcodes for the xFileControl method

  1853. ** of the [sqlite3_io_methods] object and for the [sqlite3_file_control()]

  1854. ** interface.

  1855. **

  1856. ** <ul>

  1857. ** <li>[[SQLITE_FCNTL_LOCKSTATE]]

  1858. ** The [SQLITE_FCNTL_LOCKSTATE] opcode is used for debugging.  This

  1859. ** opcode causes the xFileControl method to write the current state of

  1860. ** the lock (one of [SQLITE_LOCK_NONE], [SQLITE_LOCK_SHARED],

  1861. ** [SQLITE_LOCK_RESERVED], [SQLITE_LOCK_PENDING], or [SQLITE_LOCK_EXCLUSIVE])

  1862. ** into an integer that the pArg argument points to. This capability

  1863. ** is used during testing and is only available when the SQLITE_TEST

  1864. ** compile-time option is used.

  1865. **

  1866. ** <li>[[SQLITE_FCNTL_SIZE_HINT]]

  1867. ** The [SQLITE_FCNTL_SIZE_HINT] opcode is used by SQLite to give the VFS

  1868. ** layer a hint of how large the database file will grow to be during the

  1869. ** current transaction.  This hint is not guaranteed to be accurate but it

  1870. ** is often close.  The underlying VFS might choose to preallocate database

  1871. ** file space based on this hint in order to help writes to the database

  1872. ** file run faster.

  1873. **

  1874. ** <li>[[SQLITE_FCNTL_SIZE_LIMIT]]

  1875. ** The [SQLITE_FCNTL_SIZE_LIMIT] opcode is used by in-memory VFS that

  1876. ** implements [sqlite3_deserialize()] to set an upper bound on the size

  1877. ** of the in-memory database.  The argument is a pointer to a [sqlite3_int64].

  1878. ** If the integer pointed to is negative, then it is filled in with the

  1879. ** current limit.  Otherwise the limit is set to the larger of the value

  1880. ** of the integer pointed to and the current database size.  The integer

  1881. ** pointed to is set to the new limit.

  1882. **

  1883. ** <li>[[SQLITE_FCNTL_CHUNK_SIZE]]

  1884. ** The [SQLITE_FCNTL_CHUNK_SIZE] opcode is used to request that the VFS

  1885. ** extends and truncates the database file in chunks of a size specified

  1886. ** by the user. The fourth argument to [sqlite3_file_control()] should 

  1887. ** point to an integer (type int) containing the new chunk-size to use

  1888. ** for the nominated database. Allocating database file space in large

  1889. ** chunks (say 1MB at a time), may reduce file-system fragmentation and

  1890. ** improve performance on some systems.

  1891. **

  1892. ** <li>[[SQLITE_FCNTL_FILE_POINTER]]

  1893. ** The [SQLITE_FCNTL_FILE_POINTER] opcode is used to obtain a pointer

  1894. ** to the [sqlite3_file] object associated with a particular database

  1895. ** connection.  See also [SQLITE_FCNTL_JOURNAL_POINTER].

  1896. **

  1897. ** <li>[[SQLITE_FCNTL_JOURNAL_POINTER]]

  1898. ** The [SQLITE_FCNTL_JOURNAL_POINTER] opcode is used to obtain a pointer

  1899. ** to the [sqlite3_file] object associated with the journal file (either

  1900. ** the [rollback journal] or the [write-ahead log]) for a particular database

  1901. ** connection.  See also [SQLITE_FCNTL_FILE_POINTER].

  1902. **

  1903. ** <li>[[SQLITE_FCNTL_SYNC_OMITTED]]

  1904. ** No longer in use.

  1905. **

  1906. ** <li>[[SQLITE_FCNTL_SYNC]]

  1907. ** The [SQLITE_FCNTL_SYNC] opcode is generated internally by SQLite and

  1908. ** sent to the VFS immediately before the xSync method is invoked on a

  1909. ** database file descriptor. Or, if the xSync method is not invoked 

  1910. ** because the user has configured SQLite with 

  1911. ** [PRAGMA synchronous | PRAGMA synchronous=OFF] it is invoked in place 

  1912. ** of the xSync method. In most cases, the pointer argument passed with

  1913. ** this file-control is NULL. However, if the database file is being synced

  1914. ** as part of a multi-database commit, the argument points to a nul-terminated

  1915. ** string containing the transactions master-journal file name. VFSes that 

  1916. ** do not need this signal should silently ignore this opcode. Applications 

  1917. ** should not call [sqlite3_file_control()] with this opcode as doing so may 

  1918. ** disrupt the operation of the specialized VFSes that do require it.  

  1919. **

  1920. ** <li>[[SQLITE_FCNTL_COMMIT_PHASETWO]]

  1921. ** The [SQLITE_FCNTL_COMMIT_PHASETWO] opcode is generated internally by SQLite

  1922. ** and sent to the VFS after a transaction has been committed immediately

  1923. ** but before the database is unlocked. VFSes that do not need this signal

  1924. ** should silently ignore this opcode. Applications should not call

  1925. ** [sqlite3_file_control()] with this opcode as doing so may disrupt the 

  1926. ** operation of the specialized VFSes that do require it.  

  1927. **

  1928. ** <li>[[SQLITE_FCNTL_WIN32_AV_RETRY]]

  1929. ** ^The [SQLITE_FCNTL_WIN32_AV_RETRY] opcode is used to configure automatic

  1930. ** retry counts and intervals for certain disk I/O operations for the

  1931. ** windows [VFS] in order to provide robustness in the presence of

  1932. ** anti-virus programs.  By default, the windows VFS will retry file read,

  1933. ** file write, and file delete operations up to 10 times, with a delay

  1934. ** of 25 milliseconds before the first retry and with the delay increasing

  1935. ** by an additional 25 milliseconds with each subsequent retry.  This

  1936. ** opcode allows these two values (10 retries and 25 milliseconds of delay)

  1937. ** to be adjusted.  The values are changed for all database connections

  1938. ** within the same process.  The argument is a pointer to an array of two

  1939. ** integers where the first integer is the new retry count and the second

  1940. ** integer is the delay.  If either integer is negative, then the setting

  1941. ** is not changed but instead the prior value of that setting is written

  1942. ** into the array entry, allowing the current retry settings to be

  1943. ** interrogated.  The zDbName parameter is ignored.

  1944. **

  1945. ** <li>[[SQLITE_FCNTL_PERSIST_WAL]]

  1946. ** ^The [SQLITE_FCNTL_PERSIST_WAL] opcode is used to set or query the

  1947. ** persistent [WAL | Write Ahead Log] setting.  By default, the auxiliary

  1948. ** write ahead log ([WAL file]) and shared memory

  1949. ** files used for transaction control

  1950. ** are automatically deleted when the latest connection to the database

  1951. ** closes.  Setting persistent WAL mode causes those files to persist after

  1952. ** close.  Persisting the files is useful when other processes that do not

  1953. ** have write permission on the directory containing the database file want

  1954. ** to read the database file, as the WAL and shared memory files must exist

  1955. ** in order for the database to be readable.  The fourth parameter to

  1956. ** [sqlite3_file_control()] for this opcode should be a pointer to an integer.

  1957. ** That integer is 0 to disable persistent WAL mode or 1 to enable persistent

  1958. ** WAL mode.  If the integer is -1, then it is overwritten with the current

  1959. ** WAL persistence setting.

  1960. **

  1961. ** <li>[[SQLITE_FCNTL_POWERSAFE_OVERWRITE]]

  1962. ** ^The [SQLITE_FCNTL_POWERSAFE_OVERWRITE] opcode is used to set or query the

  1963. ** persistent "powersafe-overwrite" or "PSOW" setting.  The PSOW setting

  1964. ** determines the [SQLITE_IOCAP_POWERSAFE_OVERWRITE] bit of the

  1965. ** xDeviceCharacteristics methods. The fourth parameter to

  1966. ** [sqlite3_file_control()] for this opcode should be a pointer to an integer.

  1967. ** That integer is 0 to disable zero-damage mode or 1 to enable zero-damage

  1968. ** mode.  If the integer is -1, then it is overwritten with the current

  1969. ** zero-damage mode setting.

  1970. **

  1971. ** <li>[[SQLITE_FCNTL_OVERWRITE]]

  1972. ** ^The [SQLITE_FCNTL_OVERWRITE] opcode is invoked by SQLite after opening

  1973. ** a write transaction to indicate that, unless it is rolled back for some

  1974. ** reason, the entire database file will be overwritten by the current 

  1975. ** transaction. This is used by VACUUM operations.

  1976. **

  1977. ** <li>[[SQLITE_FCNTL_VFSNAME]]

  1978. ** ^The [SQLITE_FCNTL_VFSNAME] opcode can be used to obtain the names of

  1979. ** all [VFSes] in the VFS stack.  The names are of all VFS shims and the

  1980. ** final bottom-level VFS are written into memory obtained from 

  1981. ** [sqlite3_malloc()] and the result is stored in the char* variable

  1982. ** that the fourth parameter of [sqlite3_file_control()] points to.

  1983. ** The caller is responsible for freeing the memory when done.  As with

  1984. ** all file-control actions, there is no guarantee that this will actually

  1985. ** do anything.  Callers should initialize the char* variable to a NULL

  1986. ** pointer in case this file-control is not implemented.  This file-control

  1987. ** is intended for diagnostic use only.

  1988. **

  1989. ** <li>[[SQLITE_FCNTL_VFS_POINTER]]

  1990. ** ^The [SQLITE_FCNTL_VFS_POINTER] opcode finds a pointer to the top-level

  1991. ** [VFSes] currently in use.  ^(The argument X in

  1992. ** sqlite3_file_control(db,SQLITE_FCNTL_VFS_POINTER,X) must be

  1993. ** of type "[sqlite3_vfs] **".  This opcodes will set *X

  1994. ** to a pointer to the top-level VFS.)^

  1995. ** ^When there are multiple VFS shims in the stack, this opcode finds the

  1996. ** upper-most shim only.

  1997. **

  1998. ** <li>[[SQLITE_FCNTL_PRAGMA]]

  1999. ** ^Whenever a [PRAGMA] statement is parsed, an [SQLITE_FCNTL_PRAGMA] 

  2000. ** file control is sent to the open [sqlite3_file] object corresponding

  2001. ** to the database file to which the pragma statement refers. ^The argument

  2002. ** to the [SQLITE_FCNTL_PRAGMA] file control is an array of

  2003. ** pointers to strings (char**) in which the second element of the array

  2004. ** is the name of the pragma and the third element is the argument to the

  2005. ** pragma or NULL if the pragma has no argument.  ^The handler for an

  2006. ** [SQLITE_FCNTL_PRAGMA] file control can optionally make the first element

  2007. ** of the char** argument point to a string obtained from [sqlite3_mprintf()]

  2008. ** or the equivalent and that string will become the result of the pragma or

  2009. ** the error message if the pragma fails. ^If the

  2010. ** [SQLITE_FCNTL_PRAGMA] file control returns [SQLITE_NOTFOUND], then normal 

  2011. ** [PRAGMA] processing continues.  ^If the [SQLITE_FCNTL_PRAGMA]

  2012. ** file control returns [SQLITE_OK], then the parser assumes that the

  2013. ** VFS has handled the PRAGMA itself and the parser generates a no-op

  2014. ** prepared statement if result string is NULL, or that returns a copy

  2015. ** of the result string if the string is non-NULL.

  2016. ** ^If the [SQLITE_FCNTL_PRAGMA] file control returns

  2017. ** any result code other than [SQLITE_OK] or [SQLITE_NOTFOUND], that means

  2018. ** that the VFS encountered an error while handling the [PRAGMA] and the

  2019. ** compilation of the PRAGMA fails with an error.  ^The [SQLITE_FCNTL_PRAGMA]

  2020. ** file control occurs at the beginning of pragma statement analysis and so

  2021. ** it is able to override built-in [PRAGMA] statements.

  2022. **

  2023. ** <li>[[SQLITE_FCNTL_BUSYHANDLER]]

  2024. ** ^The [SQLITE_FCNTL_BUSYHANDLER]

  2025. ** file-control may be invoked by SQLite on the database file handle

  2026. ** shortly after it is opened in order to provide a custom VFS with access

  2027. ** to the connections busy-handler callback. The argument is of type (void **)

  2028. ** - an array of two (void *) values. The first (void *) actually points

  2029. ** to a function of type (int (*)(void *)). In order to invoke the connections

  2030. ** busy-handler, this function should be invoked with the second (void *) in

  2031. ** the array as the only argument. If it returns non-zero, then the operation

  2032. ** should be retried. If it returns zero, the custom VFS should abandon the

  2033. ** current operation.

  2034. **

  2035. ** <li>[[SQLITE_FCNTL_TEMPFILENAME]]

  2036. ** ^Application can invoke the [SQLITE_FCNTL_TEMPFILENAME] file-control

  2037. ** to have SQLite generate a

  2038. ** temporary filename using the same algorithm that is followed to generate

  2039. ** temporary filenames for TEMP tables and other internal uses.  The

  2040. ** argument should be a char** which will be filled with the filename

  2041. ** written into memory obtained from [sqlite3_malloc()].  The caller should

  2042. ** invoke [sqlite3_free()] on the result to avoid a memory leak.

  2043. **

  2044. ** <li>[[SQLITE_FCNTL_MMAP_SIZE]]

  2045. ** The [SQLITE_FCNTL_MMAP_SIZE] file control is used to query or set the

  2046. ** maximum number of bytes that will be used for memory-mapped I/O.

  2047. ** The argument is a pointer to a value of type sqlite3_int64 that

  2048. ** is an advisory maximum number of bytes in the file to memory map.  The

  2049. ** pointer is overwritten with the old value.  The limit is not changed if

  2050. ** the value originally pointed to is negative, and so the current limit 

  2051. ** can be queried by passing in a pointer to a negative number.  This

  2052. ** file-control is used internally to implement [PRAGMA mmap_size].

  2053. **

  2054. ** <li>[[SQLITE_FCNTL_TRACE]]

  2055. ** The [SQLITE_FCNTL_TRACE] file control provides advisory information

  2056. ** to the VFS about what the higher layers of the SQLite stack are doing.

  2057. ** This file control is used by some VFS activity tracing [shims].

  2058. ** The argument is a zero-terminated string.  Higher layers in the

  2059. ** SQLite stack may generate instances of this file control if

  2060. ** the [SQLITE_USE_FCNTL_TRACE] compile-time option is enabled.

  2061. **

  2062. ** <li>[[SQLITE_FCNTL_HAS_MOVED]]

  2063. ** The [SQLITE_FCNTL_HAS_MOVED] file control interprets its argument as a

  2064. ** pointer to an integer and it writes a boolean into that integer depending

  2065. ** on whether or not the file has been renamed, moved, or deleted since it

  2066. ** was first opened.

  2067. **

  2068. ** <li>[[SQLITE_FCNTL_WIN32_GET_HANDLE]]

  2069. ** The [SQLITE_FCNTL_WIN32_GET_HANDLE] opcode can be used to obtain the

  2070. ** underlying native file handle associated with a file handle.  This file

  2071. ** control interprets its argument as a pointer to a native file handle and

  2072. ** writes the resulting value there.

  2073. **

  2074. ** <li>[[SQLITE_FCNTL_WIN32_SET_HANDLE]]

  2075. ** The [SQLITE_FCNTL_WIN32_SET_HANDLE] opcode is used for debugging.  This

  2076. ** opcode causes the xFileControl method to swap the file handle with the one

  2077. ** pointed to by the pArg argument.  This capability is used during testing

  2078. ** and only needs to be supported when SQLITE_TEST is defined.

  2079. **

  2080. ** <li>[[SQLITE_FCNTL_WAL_BLOCK]]

  2081. ** The [SQLITE_FCNTL_WAL_BLOCK] is a signal to the VFS layer that it might

  2082. ** be advantageous to block on the next WAL lock if the lock is not immediately

  2083. ** available.  The WAL subsystem issues this signal during rare

  2084. ** circumstances in order to fix a problem with priority inversion.

  2085. ** Applications should <em>not</em> use this file-control.

  2086. **

  2087. ** <li>[[SQLITE_FCNTL_ZIPVFS]]

  2088. ** The [SQLITE_FCNTL_ZIPVFS] opcode is implemented by zipvfs only. All other

  2089. ** VFS should return SQLITE_NOTFOUND for this opcode.

  2090. **

  2091. ** <li>[[SQLITE_FCNTL_RBU]]

  2092. ** The [SQLITE_FCNTL_RBU] opcode is implemented by the special VFS used by

  2093. ** the RBU extension only.  All other VFS should return SQLITE_NOTFOUND for

  2094. ** this opcode.  

  2095. **

  2096. ** <li>[[SQLITE_FCNTL_BEGIN_ATOMIC_WRITE]]

  2097. ** If the [SQLITE_FCNTL_BEGIN_ATOMIC_WRITE] opcode returns SQLITE_OK, then

  2098. ** the file descriptor is placed in "batch write mode", which

  2099. ** means all subsequent write operations will be deferred and done

  2100. ** atomically at the next [SQLITE_FCNTL_COMMIT_ATOMIC_WRITE].  Systems

  2101. ** that do not support batch atomic writes will return SQLITE_NOTFOUND.

  2102. ** ^Following a successful SQLITE_FCNTL_BEGIN_ATOMIC_WRITE and prior to

  2103. ** the closing [SQLITE_FCNTL_COMMIT_ATOMIC_WRITE] or

  2104. ** [SQLITE_FCNTL_ROLLBACK_ATOMIC_WRITE], SQLite will make

  2105. ** no VFS interface calls on the same [sqlite3_file] file descriptor

  2106. ** except for calls to the xWrite method and the xFileControl method

  2107. ** with [SQLITE_FCNTL_SIZE_HINT].

  2108. **

  2109. ** <li>[[SQLITE_FCNTL_COMMIT_ATOMIC_WRITE]]

  2110. ** The [SQLITE_FCNTL_COMMIT_ATOMIC_WRITE] opcode causes all write

  2111. ** operations since the previous successful call to 

  2112. ** [SQLITE_FCNTL_BEGIN_ATOMIC_WRITE] to be performed atomically.

  2113. ** This file control returns [SQLITE_OK] if and only if the writes were

  2114. ** all performed successfully and have been committed to persistent storage.

  2115. ** ^Regardless of whether or not it is successful, this file control takes

  2116. ** the file descriptor out of batch write mode so that all subsequent

  2117. ** write operations are independent.

  2118. ** ^SQLite will never invoke SQLITE_FCNTL_COMMIT_ATOMIC_WRITE without

  2119. ** a prior successful call to [SQLITE_FCNTL_BEGIN_ATOMIC_WRITE].

  2120. **

  2121. ** <li>[[SQLITE_FCNTL_ROLLBACK_ATOMIC_WRITE]]

  2122. ** The [SQLITE_FCNTL_ROLLBACK_ATOMIC_WRITE] opcode causes all write

  2123. ** operations since the previous successful call to 

  2124. ** [SQLITE_FCNTL_BEGIN_ATOMIC_WRITE] to be rolled back.

  2125. ** ^This file control takes the file descriptor out of batch write mode

  2126. ** so that all subsequent write operations are independent.

  2127. ** ^SQLite will never invoke SQLITE_FCNTL_ROLLBACK_ATOMIC_WRITE without

  2128. ** a prior successful call to [SQLITE_FCNTL_BEGIN_ATOMIC_WRITE].

  2129. **

  2130. ** <li>[[SQLITE_FCNTL_LOCK_TIMEOUT]]

  2131. ** The [SQLITE_FCNTL_LOCK_TIMEOUT] opcode causes attempts to obtain

  2132. ** a file lock using the xLock or xShmLock methods of the VFS to wait

  2133. ** for up to M milliseconds before failing, where M is the single 

  2134. ** unsigned integer parameter.

  2135. **

  2136. ** <li>[[SQLITE_FCNTL_DATA_VERSION]]

  2137. ** The [SQLITE_FCNTL_DATA_VERSION] opcode is used to detect changes to

  2138. ** a database file.  The argument is a pointer to a 32-bit unsigned integer.

  2139. ** The "data version" for the pager is written into the pointer.  The

  2140. ** "data version" changes whenever any change occurs to the corresponding

  2141. ** database file, either through SQL statements on the same database

  2142. ** connection or through transactions committed by separate database

  2143. ** connections possibly in other processes. The [sqlite3_total_changes()]

  2144. ** interface can be used to find if any database on the connection has changed,

  2145. ** but that interface responds to changes on TEMP as well as MAIN and does

  2146. ** not provide a mechanism to detect changes to MAIN only.  Also, the

  2147. ** [sqlite3_total_changes()] interface responds to internal changes only and

  2148. ** omits changes made by other database connections.  The

  2149. ** [PRAGMA data_version] command provide a mechanism to detect changes to

  2150. ** a single attached database that occur due to other database connections,

  2151. ** but omits changes implemented by the database connection on which it is

  2152. ** called.  This file control is the only mechanism to detect changes that

  2153. ** happen either internally or externally and that are associated with

  2154. ** a particular attached database.

  2155. ** </ul>

  2156. */

  2157. #define SQLITE_FCNTL_LOCKSTATE               1

  2158. #define SQLITE_FCNTL_GET_LOCKPROXYFILE       2

  2159. #define SQLITE_FCNTL_SET_LOCKPROXYFILE       3

  2160. #define SQLITE_FCNTL_LAST_ERRNO              4

  2161. #define SQLITE_FCNTL_SIZE_HINT               5

  2162. #define SQLITE_FCNTL_CHUNK_SIZE              6

  2163. #define SQLITE_FCNTL_FILE_POINTER            7

  2164. #define SQLITE_FCNTL_SYNC_OMITTED            8

  2165. #define SQLITE_FCNTL_WIN32_AV_RETRY          9

  2166. #define SQLITE_FCNTL_PERSIST_WAL            10

  2167. #define SQLITE_FCNTL_OVERWRITE              11

  2168. #define SQLITE_FCNTL_VFSNAME                12

  2169. #define SQLITE_FCNTL_POWERSAFE_OVERWRITE    13

  2170. #define SQLITE_FCNTL_PRAGMA                 14

  2171. #define SQLITE_FCNTL_BUSYHANDLER            15

  2172. #define SQLITE_FCNTL_TEMPFILENAME           16

  2173. #define SQLITE_FCNTL_MMAP_SIZE              18

  2174. #define SQLITE_FCNTL_TRACE                  19

  2175. #define SQLITE_FCNTL_HAS_MOVED              20

  2176. #define SQLITE_FCNTL_SYNC                   21

  2177. #define SQLITE_FCNTL_COMMIT_PHASETWO        22

  2178. #define SQLITE_FCNTL_WIN32_SET_HANDLE       23

  2179. #define SQLITE_FCNTL_WAL_BLOCK              24

  2180. #define SQLITE_FCNTL_ZIPVFS                 25

  2181. #define SQLITE_FCNTL_RBU                    26

  2182. #define SQLITE_FCNTL_VFS_POINTER            27

  2183. #define SQLITE_FCNTL_JOURNAL_POINTER        28

  2184. #define SQLITE_FCNTL_WIN32_GET_HANDLE       29

  2185. #define SQLITE_FCNTL_PDB                    30

  2186. #define SQLITE_FCNTL_BEGIN_ATOMIC_WRITE     31

  2187. #define SQLITE_FCNTL_COMMIT_ATOMIC_WRITE    32

  2188. #define SQLITE_FCNTL_ROLLBACK_ATOMIC_WRITE  33

  2189. #define SQLITE_FCNTL_LOCK_TIMEOUT           34

  2190. #define SQLITE_FCNTL_DATA_VERSION           35

  2191. #define SQLITE_FCNTL_SIZE_LIMIT             36

  2192. 

  2193. /* deprecated names */

  2194. #define SQLITE_GET_LOCKPROXYFILE      SQLITE_FCNTL_GET_LOCKPROXYFILE

  2195. #define SQLITE_SET_LOCKPROXYFILE      SQLITE_FCNTL_SET_LOCKPROXYFILE

  2196. #define SQLITE_LAST_ERRNO             SQLITE_FCNTL_LAST_ERRNO

  2197. 

  2198. 

  2199. /*

  2200. ** CAPI3REF: Mutex Handle

  2201. **

  2202. ** The mutex module within SQLite defines [sqlite3_mutex] to be an

  2203. ** abstract type for a mutex object.  The SQLite core never looks

  2204. ** at the internal representation of an [sqlite3_mutex].  It only

  2205. ** deals with pointers to the [sqlite3_mutex] object.

  2206. **

  2207. ** Mutexes are created using [sqlite3_mutex_alloc()].

  2208. */

  2209. typedef struct sqlite3_mutex sqlite3_mutex;

  2210. 

  2211. /*

  2212. ** CAPI3REF: Loadable Extension Thunk

  2213. **

  2214. ** A pointer to the opaque sqlite3_api_routines structure is passed as

  2215. ** the third parameter to entry points of [loadable extensions].  This

  2216. ** structure must be typedefed in order to work around compiler warnings

  2217. ** on some platforms.

  2218. */

  2219. typedef struct sqlite3_api_routines sqlite3_api_routines;

  2220. 

  2221. /*

  2222. ** CAPI3REF: OS Interface Object

  2223. **

  2224. ** An instance of the sqlite3_vfs object defines the interface between

  2225. ** the SQLite core and the underlying operating system.  The "vfs"

  2226. ** in the name of the object stands for "virtual file system".  See

  2227. ** the [VFS | VFS documentation] for further information.

  2228. **

  2229. ** The VFS interface is sometimes extended by adding new methods onto

  2230. ** the end.  Each time such an extension occurs, the iVersion field

  2231. ** is incremented.  The iVersion value started out as 1 in

  2232. ** SQLite [version 3.5.0] on [dateof:3.5.0], then increased to 2

  2233. ** with SQLite [version 3.7.0] on [dateof:3.7.0], and then increased

  2234. ** to 3 with SQLite [version 3.7.6] on [dateof:3.7.6].  Additional fields

  2235. ** may be appended to the sqlite3_vfs object and the iVersion value

  2236. ** may increase again in future versions of SQLite.

  2237. ** Note that the structure

  2238. ** of the sqlite3_vfs object changes in the transition from

  2239. ** SQLite [version 3.5.9] to [version 3.6.0] on [dateof:3.6.0]

  2240. ** and yet the iVersion field was not modified.

  2241. **

  2242. ** The szOsFile field is the size of the subclassed [sqlite3_file]

  2243. ** structure used by this VFS.  mxPathname is the maximum length of

  2244. ** a pathname in this VFS.

  2245. **

  2246. ** Registered sqlite3_vfs objects are kept on a linked list formed by

  2247. ** the pNext pointer.  The [sqlite3_vfs_register()]

  2248. ** and [sqlite3_vfs_unregister()] interfaces manage this list

  2249. ** in a thread-safe way.  The [sqlite3_vfs_find()] interface

  2250. ** searches the list.  Neither the application code nor the VFS

  2251. ** implementation should use the pNext pointer.

  2252. **

  2253. ** The pNext field is the only field in the sqlite3_vfs

  2254. ** structure that SQLite will ever modify.  SQLite will only access

  2255. ** or modify this field while holding a particular static mutex.

  2256. ** The application should never modify anything within the sqlite3_vfs

  2257. ** object once the object has been registered.

  2258. **

  2259. ** The zName field holds the name of the VFS module.  The name must

  2260. ** be unique across all VFS modules.

  2261. **

  2262. ** [[sqlite3_vfs.xOpen]]

  2263. ** ^SQLite guarantees that the zFilename parameter to xOpen

  2264. ** is either a NULL pointer or string obtained

  2265. ** from xFullPathname() with an optional suffix added.

  2266. ** ^If a suffix is added to the zFilename parameter, it will

  2267. ** consist of a single "-" character followed by no more than

  2268. ** 11 alphanumeric and/or "-" characters.

  2269. ** ^SQLite further guarantees that

  2270. ** the string will be valid and unchanged until xClose() is

  2271. ** called. Because of the previous sentence,

  2272. ** the [sqlite3_file] can safely store a pointer to the

  2273. ** filename if it needs to remember the filename for some reason.

  2274. ** If the zFilename parameter to xOpen is a NULL pointer then xOpen

  2275. ** must invent its own temporary name for the file.  ^Whenever the 

  2276. ** xFilename parameter is NULL it will also be the case that the

  2277. ** flags parameter will include [SQLITE_OPEN_DELETEONCLOSE].

  2278. **

  2279. ** The flags argument to xOpen() includes all bits set in

  2280. ** the flags argument to [sqlite3_open_v2()].  Or if [sqlite3_open()]

  2281. ** or [sqlite3_open16()] is used, then flags includes at least

  2282. ** [SQLITE_OPEN_READWRITE] | [SQLITE_OPEN_CREATE]. 

  2283. ** If xOpen() opens a file read-only then it sets *pOutFlags to

  2284. ** include [SQLITE_OPEN_READONLY].  Other bits in *pOutFlags may be set.

  2285. **

  2286. ** ^(SQLite will also add one of the following flags to the xOpen()

  2287. ** call, depending on the object being opened:

  2288. **

  2289. ** <ul>

  2290. ** <li>  [SQLITE_OPEN_MAIN_DB]

  2291. ** <li>  [SQLITE_OPEN_MAIN_JOURNAL]

  2292. ** <li>  [SQLITE_OPEN_TEMP_DB]

  2293. ** <li>  [SQLITE_OPEN_TEMP_JOURNAL]

  2294. ** <li>  [SQLITE_OPEN_TRANSIENT_DB]

  2295. ** <li>  [SQLITE_OPEN_SUBJOURNAL]

  2296. ** <li>  [SQLITE_OPEN_MASTER_JOURNAL]

  2297. ** <li>  [SQLITE_OPEN_WAL]

  2298. ** </ul>)^

  2299. **

  2300. ** The file I/O implementation can use the object type flags to

  2301. ** change the way it deals with files.  For example, an application

  2302. ** that does not care about crash recovery or rollback might make

  2303. ** the open of a journal file a no-op.  Writes to this journal would

  2304. ** also be no-ops, and any attempt to read the journal would return

  2305. ** SQLITE_IOERR.  Or the implementation might recognize that a database

  2306. ** file will be doing page-aligned sector reads and writes in a random

  2307. ** order and set up its I/O subsystem accordingly.

  2308. **

  2309. ** SQLite might also add one of the following flags to the xOpen method:

  2310. **

  2311. ** <ul>

  2312. ** <li> [SQLITE_OPEN_DELETEONCLOSE]

  2313. ** <li> [SQLITE_OPEN_EXCLUSIVE]

  2314. ** </ul>

  2315. **

  2316. ** The [SQLITE_OPEN_DELETEONCLOSE] flag means the file should be

  2317. ** deleted when it is closed.  ^The [SQLITE_OPEN_DELETEONCLOSE]

  2318. ** will be set for TEMP databases and their journals, transient

  2319. ** databases, and subjournals.

  2320. **

  2321. ** ^The [SQLITE_OPEN_EXCLUSIVE] flag is always used in conjunction

  2322. ** with the [SQLITE_OPEN_CREATE] flag, which are both directly

  2323. ** analogous to the O_EXCL and O_CREAT flags of the POSIX open()

  2324. ** API.  The SQLITE_OPEN_EXCLUSIVE flag, when paired with the 

  2325. ** SQLITE_OPEN_CREATE, is used to indicate that file should always

  2326. ** be created, and that it is an error if it already exists.

  2327. ** It is <i>not</i> used to indicate the file should be opened 

  2328. ** for exclusive access.

  2329. **

  2330. ** ^At least szOsFile bytes of memory are allocated by SQLite

  2331. ** to hold the  [sqlite3_file] structure passed as the third

  2332. ** argument to xOpen.  The xOpen method does not have to

  2333. ** allocate the structure; it should just fill it in.  Note that

  2334. ** the xOpen method must set the sqlite3_file.pMethods to either

  2335. ** a valid [sqlite3_io_methods] object or to NULL.  xOpen must do

  2336. ** this even if the open fails.  SQLite expects that the sqlite3_file.pMethods

  2337. ** element will be valid after xOpen returns regardless of the success

  2338. ** or failure of the xOpen call.

  2339. **

  2340. ** [[sqlite3_vfs.xAccess]]

  2341. ** ^The flags argument to xAccess() may be [SQLITE_ACCESS_EXISTS]

  2342. ** to test for the existence of a file, or [SQLITE_ACCESS_READWRITE] to

  2343. ** test whether a file is readable and writable, or [SQLITE_ACCESS_READ]

  2344. ** to test whether a file is at least readable.  The SQLITE_ACCESS_READ

  2345. ** flag is never actually used and is not implemented in the built-in

  2346. ** VFSes of SQLite.  The file is named by the second argument and can be a

  2347. ** directory. The xAccess method returns [SQLITE_OK] on success or some

  2348. ** non-zero error code if there is an I/O error or if the name of

  2349. ** the file given in the second argument is illegal.  If SQLITE_OK

  2350. ** is returned, then non-zero or zero is written into *pResOut to indicate

  2351. ** whether or not the file is accessible.  

  2352. **

  2353. ** ^SQLite will always allocate at least mxPathname+1 bytes for the

  2354. ** output buffer xFullPathname.  The exact size of the output buffer

  2355. ** is also passed as a parameter to both  methods. If the output buffer

  2356. ** is not large enough, [SQLITE_CANTOPEN] should be returned. Since this is

  2357. ** handled as a fatal error by SQLite, vfs implementations should endeavor

  2358. ** to prevent this by setting mxPathname to a sufficiently large value.

  2359. **

  2360. ** The xRandomness(), xSleep(), xCurrentTime(), and xCurrentTimeInt64()

  2361. ** interfaces are not strictly a part of the filesystem, but they are

  2362. ** included in the VFS structure for completeness.

  2363. ** The xRandomness() function attempts to return nBytes bytes

  2364. ** of good-quality randomness into zOut.  The return value is

  2365. ** the actual number of bytes of randomness obtained.

  2366. ** The xSleep() method causes the calling thread to sleep for at

  2367. ** least the number of microseconds given.  ^The xCurrentTime()

  2368. ** method returns a Julian Day Number for the current date and time as

  2369. ** a floating point value.

  2370. ** ^The xCurrentTimeInt64() method returns, as an integer, the Julian

  2371. ** Day Number multiplied by 86400000 (the number of milliseconds in 

  2372. ** a 24-hour day).  

  2373. ** ^SQLite will use the xCurrentTimeInt64() method to get the current

  2374. ** date and time if that method is available (if iVersion is 2 or 

  2375. ** greater and the function pointer is not NULL) and will fall back

  2376. ** to xCurrentTime() if xCurrentTimeInt64() is unavailable.

  2377. **

  2378. ** ^The xSetSystemCall(), xGetSystemCall(), and xNestSystemCall() interfaces

  2379. ** are not used by the SQLite core.  These optional interfaces are provided

  2380. ** by some VFSes to facilitate testing of the VFS code. By overriding 

  2381. ** system calls with functions under its control, a test program can

  2382. ** simulate faults and error conditions that would otherwise be difficult

  2383. ** or impossible to induce.  The set of system calls that can be overridden

  2384. ** varies from one VFS to another, and from one version of the same VFS to the

  2385. ** next.  Applications that use these interfaces must be prepared for any

  2386. ** or all of these interfaces to be NULL or for their behavior to change

  2387. ** from one release to the next.  Applications must not attempt to access

  2388. ** any of these methods if the iVersion of the VFS is less than 3.

  2389. */

  2390. typedef struct sqlite3_vfs sqlite3_vfs;

  2391. typedef void (*sqlite3_syscall_ptr)(void);

  2392. struct sqlite3_vfs {

  2393.   int iVersion;            /* Structure version number (currently 3) */

  2394.   int szOsFile;            /* Size of subclassed sqlite3_file */

  2395.   int mxPathname;          /* Maximum file pathname length */

  2396.   sqlite3_vfs *pNext;      /* Next registered VFS */

  2397.   const char *zName;       /* Name of this virtual file system */

  2398.   void *pAppData;          /* Pointer to application-specific data */

  2399.   int (*xOpen)(sqlite3_vfs*, const char *zName, sqlite3_file*,

  2400.                int flags, int *pOutFlags);

  2401.   int (*xDelete)(sqlite3_vfs*, const char *zName, int syncDir);

  2402.   int (*xAccess)(sqlite3_vfs*, const char *zName, int flags, int *pResOut);

  2403.   int (*xFullPathname)(sqlite3_vfs*, const char *zName, int nOut, char *zOut);

  2404.   void *(*xDlOpen)(sqlite3_vfs*, const char *zFilename);

  2405.   void (*xDlError)(sqlite3_vfs*, int nByte, char *zErrMsg);

  2406.   void (*(*xDlSym)(sqlite3_vfs*,void*, const char *zSymbol))(void);

  2407.   void (*xDlClose)(sqlite3_vfs*, void*);

  2408.   int (*xRandomness)(sqlite3_vfs*, int nByte, char *zOut);

  2409.   int (*xSleep)(sqlite3_vfs*, int microseconds);

  2410.   int (*xCurrentTime)(sqlite3_vfs*, double*);

  2411.   int (*xGetLastError)(sqlite3_vfs*, int, char *);

  2412.   /*

  2413.   ** The methods above are in version 1 of the sqlite_vfs object

  2414.   ** definition.  Those that follow are added in version 2 or later

  2415.   */

  2416.   int (*xCurrentTimeInt64)(sqlite3_vfs*, sqlite3_int64*);

  2417.   /*

  2418.   ** The methods above are in versions 1 and 2 of the sqlite_vfs object.

  2419.   ** Those below are for version 3 and greater.

  2420.   */

  2421.   int (*xSetSystemCall)(sqlite3_vfs*, const char *zName, sqlite3_syscall_ptr);

  2422.   sqlite3_syscall_ptr (*xGetSystemCall)(sqlite3_vfs*, const char *zName);

  2423.   const char *(*xNextSystemCall)(sqlite3_vfs*, const char *zName);

  2424.   /*

  2425.   ** The methods above are in versions 1 through 3 of the sqlite_vfs object.

  2426.   ** New fields may be appended in future versions.  The iVersion

  2427.   ** value will increment whenever this happens. 

  2428.   */

  2429. };

  2430. 

  2431. /*

  2432. ** CAPI3REF: Flags for the xAccess VFS method

  2433. **

  2434. ** These integer constants can be used as the third parameter to

  2435. ** the xAccess method of an [sqlite3_vfs] object.  They determine

  2436. ** what kind of permissions the xAccess method is looking for.

  2437. ** With SQLITE_ACCESS_EXISTS, the xAccess method

  2438. ** simply checks whether the file exists.

  2439. ** With SQLITE_ACCESS_READWRITE, the xAccess method

  2440. ** checks whether the named directory is both readable and writable

  2441. ** (in other words, if files can be added, removed, and renamed within

  2442. ** the directory).

  2443. ** The SQLITE_ACCESS_READWRITE constant is currently used only by the

  2444. ** [temp_store_directory pragma], though this could change in a future

  2445. ** release of SQLite.

  2446. ** With SQLITE_ACCESS_READ, the xAccess method

  2447. ** checks whether the file is readable.  The SQLITE_ACCESS_READ constant is

  2448. ** currently unused, though it might be used in a future release of

  2449. ** SQLite.

  2450. */

  2451. #define SQLITE_ACCESS_EXISTS    0

  2452. #define SQLITE_ACCESS_READWRITE 1   /* Used by PRAGMA temp_store_directory */

  2453. #define SQLITE_ACCESS_READ      2   /* Unused */

  2454. 

  2455. /*

  2456. ** CAPI3REF: Flags for the xShmLock VFS method

  2457. **

  2458. ** These integer constants define the various locking operations

  2459. ** allowed by the xShmLock method of [sqlite3_io_methods].  The

  2460. ** following are the only legal combinations of flags to the

  2461. ** xShmLock method:

  2462. **

  2463. ** <ul>

  2464. ** <li>  SQLITE_SHM_LOCK | SQLITE_SHM_SHARED

  2465. ** <li>  SQLITE_SHM_LOCK | SQLITE_SHM_EXCLUSIVE

  2466. ** <li>  SQLITE_SHM_UNLOCK | SQLITE_SHM_SHARED

  2467. ** <li>  SQLITE_SHM_UNLOCK | SQLITE_SHM_EXCLUSIVE

  2468. ** </ul>

  2469. **

  2470. ** When unlocking, the same SHARED or EXCLUSIVE flag must be supplied as

  2471. ** was given on the corresponding lock.  

  2472. **

  2473. ** The xShmLock method can transition between unlocked and SHARED or

  2474. ** between unlocked and EXCLUSIVE.  It cannot transition between SHARED

  2475. ** and EXCLUSIVE.

  2476. */

  2477. #define SQLITE_SHM_UNLOCK       1

  2478. #define SQLITE_SHM_LOCK         2

  2479. #define SQLITE_SHM_SHARED       4

  2480. #define SQLITE_SHM_EXCLUSIVE    8

  2481. 

  2482. /*

  2483. ** CAPI3REF: Maximum xShmLock index

  2484. **

  2485. ** The xShmLock method on [sqlite3_io_methods] may use values

  2486. ** between 0 and this upper bound as its "offset" argument.

  2487. ** The SQLite core will never attempt to acquire or release a

  2488. ** lock outside of this range

  2489. */

  2490. #define SQLITE_SHM_NLOCK        8

  2491. 

  2492. 

  2493. /*

  2494. ** CAPI3REF: Initialize The SQLite Library

  2495. **

  2496. ** ^The sqlite3_initialize() routine initializes the

  2497. ** SQLite library.  ^The sqlite3_shutdown() routine

  2498. ** deallocates any resources that were allocated by sqlite3_initialize().

  2499. ** These routines are designed to aid in process initialization and

  2500. ** shutdown on embedded systems.  Workstation applications using

  2501. ** SQLite normally do not need to invoke either of these routines.

  2502. **

  2503. ** A call to sqlite3_initialize() is an "effective" call if it is

  2504. ** the first time sqlite3_initialize() is invoked during the lifetime of

  2505. ** the process, or if it is the first time sqlite3_initialize() is invoked

  2506. ** following a call to sqlite3_shutdown().  ^(Only an effective call

  2507. ** of sqlite3_initialize() does any initialization.  All other calls

  2508. ** are harmless no-ops.)^

  2509. **

  2510. ** A call to sqlite3_shutdown() is an "effective" call if it is the first

  2511. ** call to sqlite3_shutdown() since the last sqlite3_initialize().  ^(Only

  2512. ** an effective call to sqlite3_shutdown() does any deinitialization.

  2513. ** All other valid calls to sqlite3_shutdown() are harmless no-ops.)^

  2514. **

  2515. ** The sqlite3_initialize() interface is threadsafe, but sqlite3_shutdown()

  2516. ** is not.  The sqlite3_shutdown() interface must only be called from a

  2517. ** single thread.  All open [database connections] must be closed and all

  2518. ** other SQLite resources must be deallocated prior to invoking

  2519. ** sqlite3_shutdown().

  2520. **

  2521. ** Among other things, ^sqlite3_initialize() will invoke

  2522. ** sqlite3_os_init().  Similarly, ^sqlite3_shutdown()

  2523. ** will invoke sqlite3_os_end().

  2524. **

  2525. ** ^The sqlite3_initialize() routine returns [SQLITE_OK] on success.

  2526. ** ^If for some reason, sqlite3_initialize() is unable to initialize

  2527. ** the library (perhaps it is unable to allocate a needed resource such

  2528. ** as a mutex) it returns an [error code] other than [SQLITE_OK].

  2529. **

  2530. ** ^The sqlite3_initialize() routine is called internally by many other

  2531. ** SQLite interfaces so that an application usually does not need to

  2532. ** invoke sqlite3_initialize() directly.  For example, [sqlite3_open()]

  2533. ** calls sqlite3_initialize() so the SQLite library will be automatically

  2534. ** initialized when [sqlite3_open()] is called if it has not be initialized

  2535. ** already.  ^However, if SQLite is compiled with the [SQLITE_OMIT_AUTOINIT]

  2536. ** compile-time option, then the automatic calls to sqlite3_initialize()

  2537. ** are omitted and the application must call sqlite3_initialize() directly

  2538. ** prior to using any other SQLite interface.  For maximum portability,

  2539. ** it is recommended that applications always invoke sqlite3_initialize()

  2540. ** directly prior to using any other SQLite interface.  Future releases

  2541. ** of SQLite may require this.  In other words, the behavior exhibited

  2542. ** when SQLite is compiled with [SQLITE_OMIT_AUTOINIT] might become the

  2543. ** default behavior in some future release of SQLite.

  2544. **

  2545. ** The sqlite3_os_init() routine does operating-system specific

  2546. ** initialization of the SQLite library.  The sqlite3_os_end()

  2547. ** routine undoes the effect of sqlite3_os_init().  Typical tasks

  2548. ** performed by these routines include allocation or deallocation

  2549. ** of static resources, initialization of global variables,

  2550. ** setting up a default [sqlite3_vfs] module, or setting up

  2551. ** a default configuration using [sqlite3_config()].

  2552. **

  2553. ** The application should never invoke either sqlite3_os_init()

  2554. ** or sqlite3_os_end() directly.  The application should only invoke

  2555. ** sqlite3_initialize() and sqlite3_shutdown().  The sqlite3_os_init()

  2556. ** interface is called automatically by sqlite3_initialize() and

  2557. ** sqlite3_os_end() is called by sqlite3_shutdown().  Appropriate

  2558. ** implementations for sqlite3_os_init() and sqlite3_os_end()

  2559. ** are built into SQLite when it is compiled for Unix, Windows, or OS/2.

  2560. ** When [custom builds | built for other platforms]

  2561. ** (using the [SQLITE_OS_OTHER=1] compile-time

  2562. ** option) the application must supply a suitable implementation for

  2563. ** sqlite3_os_init() and sqlite3_os_end().  An application-supplied

  2564. ** implementation of sqlite3_os_init() or sqlite3_os_end()

  2565. ** must return [SQLITE_OK] on success and some other [error code] upon

  2566. ** failure.

  2567. */

  2568. SQLITE_API int sqlite3_initialize(void);

  2569. SQLITE_API int sqlite3_shutdown(void);

  2570. SQLITE_API int sqlite3_os_init(void);

  2571. SQLITE_API int sqlite3_os_end(void);

  2572. 

  2573. /*

  2574. ** CAPI3REF: Configuring The SQLite Library

  2575. **

  2576. ** The sqlite3_config() interface is used to make global configuration

  2577. ** changes to SQLite in order to tune SQLite to the specific needs of

  2578. ** the application.  The default configuration is recommended for most

  2579. ** applications and so this routine is usually not necessary.  It is

  2580. ** provided to support rare applications with unusual needs.

  2581. **

  2582. ** <b>The sqlite3_config() interface is not threadsafe. The application

  2583. ** must ensure that no other SQLite interfaces are invoked by other

  2584. ** threads while sqlite3_config() is running.</b>

  2585. **

  2586. ** The sqlite3_config() interface

  2587. ** may only be invoked prior to library initialization using

  2588. ** [sqlite3_initialize()] or after shutdown by [sqlite3_shutdown()].

  2589. ** ^If sqlite3_config() is called after [sqlite3_initialize()] and before

  2590. ** [sqlite3_shutdown()] then it will return SQLITE_MISUSE.

  2591. ** Note, however, that ^sqlite3_config() can be called as part of the

  2592. ** implementation of an application-defined [sqlite3_os_init()].

  2593. **

  2594. ** The first argument to sqlite3_config() is an integer

  2595. ** [configuration option] that determines

  2596. ** what property of SQLite is to be configured.  Subsequent arguments

  2597. ** vary depending on the [configuration option]

  2598. ** in the first argument.

  2599. **

  2600. ** ^When a configuration option is set, sqlite3_config() returns [SQLITE_OK].

  2601. ** ^If the option is unknown or SQLite is unable to set the option

  2602. ** then this routine returns a non-zero [error code].

  2603. */

  2604. SQLITE_API int sqlite3_config(int, ...);

  2605. 

  2606. /*

  2607. ** CAPI3REF: Configure database connections

  2608. ** METHOD: sqlite3

  2609. **

  2610. ** The sqlite3_db_config() interface is used to make configuration

  2611. ** changes to a [database connection].  The interface is similar to

  2612. ** [sqlite3_config()] except that the changes apply to a single

  2613. ** [database connection] (specified in the first argument).

  2614. **

  2615. ** The second argument to sqlite3_db_config(D,V,...)  is the

  2616. ** [SQLITE_DBCONFIG_LOOKASIDE | configuration verb] - an integer code 

  2617. ** that indicates what aspect of the [database connection] is being configured.

  2618. ** Subsequent arguments vary depending on the configuration verb.

  2619. **

  2620. ** ^Calls to sqlite3_db_config() return SQLITE_OK if and only if

  2621. ** the call is considered successful.

  2622. */

  2623. SQLITE_API int sqlite3_db_config(sqlite3*, int op, ...);

  2624. 

  2625. /*

  2626. ** CAPI3REF: Memory Allocation Routines

  2627. **

  2628. ** An instance of this object defines the interface between SQLite

  2629. ** and low-level memory allocation routines.

  2630. **

  2631. ** This object is used in only one place in the SQLite interface.

  2632. ** A pointer to an instance of this object is the argument to

  2633. ** [sqlite3_config()] when the configuration option is

  2634. ** [SQLITE_CONFIG_MALLOC] or [SQLITE_CONFIG_GETMALLOC].  

  2635. ** By creating an instance of this object

  2636. ** and passing it to [sqlite3_config]([SQLITE_CONFIG_MALLOC])

  2637. ** during configuration, an application can specify an alternative

  2638. ** memory allocation subsystem for SQLite to use for all of its

  2639. ** dynamic memory needs.

  2640. **

  2641. ** Note that SQLite comes with several [built-in memory allocators]

  2642. ** that are perfectly adequate for the overwhelming majority of applications

  2643. ** and that this object is only useful to a tiny minority of applications

  2644. ** with specialized memory allocation requirements.  This object is

  2645. ** also used during testing of SQLite in order to specify an alternative

  2646. ** memory allocator that simulates memory out-of-memory conditions in

  2647. ** order to verify that SQLite recovers gracefully from such

  2648. ** conditions.

  2649. **

  2650. ** The xMalloc, xRealloc, and xFree methods must work like the

  2651. ** malloc(), realloc() and free() functions from the standard C library.

  2652. ** ^SQLite guarantees that the second argument to

  2653. ** xRealloc is always a value returned by a prior call to xRoundup.

  2654. **

  2655. ** xSize should return the allocated size of a memory allocation

  2656. ** previously obtained from xMalloc or xRealloc.  The allocated size

  2657. ** is always at least as big as the requested size but may be larger.

  2658. **

  2659. ** The xRoundup method returns what would be the allocated size of

  2660. ** a memory allocation given a particular requested size.  Most memory

  2661. ** allocators round up memory allocations at least to the next multiple

  2662. ** of 8.  Some allocators round up to a larger multiple or to a power of 2.

  2663. ** Every memory allocation request coming in through [sqlite3_malloc()]

  2664. ** or [sqlite3_realloc()] first calls xRoundup.  If xRoundup returns 0, 

  2665. ** that causes the corresponding memory allocation to fail.

  2666. **

  2667. ** The xInit method initializes the memory allocator.  For example,

  2668. ** it might allocate any require mutexes or initialize internal data

  2669. ** structures.  The xShutdown method is invoked (indirectly) by

  2670. ** [sqlite3_shutdown()] and should deallocate any resources acquired

  2671. ** by xInit.  The pAppData pointer is used as the only parameter to

  2672. ** xInit and xShutdown.

  2673. **

  2674. ** SQLite holds the [SQLITE_MUTEX_STATIC_MASTER] mutex when it invokes

  2675. ** the xInit method, so the xInit method need not be threadsafe.  The

  2676. ** xShutdown method is only called from [sqlite3_shutdown()] so it does

  2677. ** not need to be threadsafe either.  For all other methods, SQLite

  2678. ** holds the [SQLITE_MUTEX_STATIC_MEM] mutex as long as the

  2679. ** [SQLITE_CONFIG_MEMSTATUS] configuration option is turned on (which

  2680. ** it is by default) and so the methods are automatically serialized.

  2681. ** However, if [SQLITE_CONFIG_MEMSTATUS] is disabled, then the other

  2682. ** methods must be threadsafe or else make their own arrangements for

  2683. ** serialization.

  2684. **

  2685. ** SQLite will never invoke xInit() more than once without an intervening

  2686. ** call to xShutdown().

  2687. */

  2688. typedef struct sqlite3_mem_methods sqlite3_mem_methods;

  2689. struct sqlite3_mem_methods {

  2690.   void *(*xMalloc)(int);         /* Memory allocation function */

  2691.   void (*xFree)(void*);          /* Free a prior allocation */

  2692.   void *(*xRealloc)(void*,int);  /* Resize an allocation */

  2693.   int (*xSize)(void*);           /* Return the size of an allocation */

  2694.   int (*xRoundup)(int);          /* Round up request size to allocation size */

  2695.   int (*xInit)(void*);           /* Initialize the memory allocator */

  2696.   void (*xShutdown)(void*);      /* Deinitialize the memory allocator */

  2697.   void *pAppData;                /* Argument to xInit() and xShutdown() */

  2698. };

  2699. 

  2700. /*

  2701. ** CAPI3REF: Configuration Options

  2702. ** KEYWORDS: {configuration option}

  2703. **

  2704. ** These constants are the available integer configuration options that

  2705. ** can be passed as the first argument to the [sqlite3_config()] interface.

  2706. **

  2707. ** New configuration options may be added in future releases of SQLite.

  2708. ** Existing configuration options might be discontinued.  Applications

  2709. ** should check the return code from [sqlite3_config()] to make sure that

  2710. ** the call worked.  The [sqlite3_config()] interface will return a

  2711. ** non-zero [error code] if a discontinued or unsupported configuration option

  2712. ** is invoked.

  2713. **

  2714. ** <dl>

  2715. ** [[SQLITE_CONFIG_SINGLETHREAD]] <dt>SQLITE_CONFIG_SINGLETHREAD</dt>

  2716. ** <dd>There are no arguments to this option.  ^This option sets the

  2717. ** [threading mode] to Single-thread.  In other words, it disables

  2718. ** all mutexing and puts SQLite into a mode where it can only be used

  2719. ** by a single thread.   ^If SQLite is compiled with

  2720. ** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then

  2721. ** it is not possible to change the [threading mode] from its default

  2722. ** value of Single-thread and so [sqlite3_config()] will return 

  2723. ** [SQLITE_ERROR] if called with the SQLITE_CONFIG_SINGLETHREAD

  2724. ** configuration option.</dd>

  2725. **

  2726. ** [[SQLITE_CONFIG_MULTITHREAD]] <dt>SQLITE_CONFIG_MULTITHREAD</dt>

  2727. ** <dd>There are no arguments to this option.  ^This option sets the

  2728. ** [threading mode] to Multi-thread.  In other words, it disables

  2729. ** mutexing on [database connection] and [prepared statement] objects.

  2730. ** The application is responsible for serializing access to

  2731. ** [database connections] and [prepared statements].  But other mutexes

  2732. ** are enabled so that SQLite will be safe to use in a multi-threaded

  2733. ** environment as long as no two threads attempt to use the same

  2734. ** [database connection] at the same time.  ^If SQLite is compiled with

  2735. ** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then

  2736. ** it is not possible to set the Multi-thread [threading mode] and

  2737. ** [sqlite3_config()] will return [SQLITE_ERROR] if called with the

  2738. ** SQLITE_CONFIG_MULTITHREAD configuration option.</dd>

  2739. **

  2740. ** [[SQLITE_CONFIG_SERIALIZED]] <dt>SQLITE_CONFIG_SERIALIZED</dt>

  2741. ** <dd>There are no arguments to this option.  ^This option sets the

  2742. ** [threading mode] to Serialized. In other words, this option enables

  2743. ** all mutexes including the recursive

  2744. ** mutexes on [database connection] and [prepared statement] objects.

  2745. ** In this mode (which is the default when SQLite is compiled with

  2746. ** [SQLITE_THREADSAFE=1]) the SQLite library will itself serialize access

  2747. ** to [database connections] and [prepared statements] so that the

  2748. ** application is free to use the same [database connection] or the

  2749. ** same [prepared statement] in different threads at the same time.

  2750. ** ^If SQLite is compiled with

  2751. ** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then

  2752. ** it is not possible to set the Serialized [threading mode] and

  2753. ** [sqlite3_config()] will return [SQLITE_ERROR] if called with the

  2754. ** SQLITE_CONFIG_SERIALIZED configuration option.</dd>

  2755. **

  2756. ** [[SQLITE_CONFIG_MALLOC]] <dt>SQLITE_CONFIG_MALLOC</dt>

  2757. ** <dd> ^(The SQLITE_CONFIG_MALLOC option takes a single argument which is 

  2758. ** a pointer to an instance of the [sqlite3_mem_methods] structure.

  2759. ** The argument specifies

  2760. ** alternative low-level memory allocation routines to be used in place of

  2761. ** the memory allocation routines built into SQLite.)^ ^SQLite makes

  2762. ** its own private copy of the content of the [sqlite3_mem_methods] structure

  2763. ** before the [sqlite3_config()] call returns.</dd>

  2764. **

  2765. ** [[SQLITE_CONFIG_GETMALLOC]] <dt>SQLITE_CONFIG_GETMALLOC</dt>

  2766. ** <dd> ^(The SQLITE_CONFIG_GETMALLOC option takes a single argument which

  2767. ** is a pointer to an instance of the [sqlite3_mem_methods] structure.

  2768. ** The [sqlite3_mem_methods]

  2769. ** structure is filled with the currently defined memory allocation routines.)^

  2770. ** This option can be used to overload the default memory allocation

  2771. ** routines with a wrapper that simulations memory allocation failure or

  2772. ** tracks memory usage, for example. </dd>

  2773. **

  2774. ** [[SQLITE_CONFIG_SMALL_MALLOC]] <dt>SQLITE_CONFIG_SMALL_MALLOC</dt>

  2775. ** <dd> ^The SQLITE_CONFIG_SMALL_MALLOC option takes single argument of

  2776. ** type int, interpreted as a boolean, which if true provides a hint to

  2777. ** SQLite that it should avoid large memory allocations if possible.

  2778. ** SQLite will run faster if it is free to make large memory allocations,

  2779. ** but some application might prefer to run slower in exchange for

  2780. ** guarantees about memory fragmentation that are possible if large

  2781. ** allocations are avoided.  This hint is normally off.

  2782. ** </dd>

  2783. **

  2784. ** [[SQLITE_CONFIG_MEMSTATUS]] <dt>SQLITE_CONFIG_MEMSTATUS</dt>

  2785. ** <dd> ^The SQLITE_CONFIG_MEMSTATUS option takes single argument of type int,

  2786. ** interpreted as a boolean, which enables or disables the collection of

  2787. ** memory allocation statistics. ^(When memory allocation statistics are

  2788. ** disabled, the following SQLite interfaces become non-operational:

  2789. **   <ul>

  2790. **   <li> [sqlite3_memory_used()]

  2791. **   <li> [sqlite3_memory_highwater()]

  2792. **   <li> [sqlite3_soft_heap_limit64()]

  2793. **   <li> [sqlite3_status64()]

  2794. **   </ul>)^

  2795. ** ^Memory allocation statistics are enabled by default unless SQLite is

  2796. ** compiled with [SQLITE_DEFAULT_MEMSTATUS]=0 in which case memory

  2797. ** allocation statistics are disabled by default.

  2798. ** </dd>

  2799. **

  2800. ** [[SQLITE_CONFIG_SCRATCH]] <dt>SQLITE_CONFIG_SCRATCH</dt>

  2801. ** <dd> The SQLITE_CONFIG_SCRATCH option is no longer used.

  2802. ** </dd>

  2803. **

  2804. ** [[SQLITE_CONFIG_PAGECACHE]] <dt>SQLITE_CONFIG_PAGECACHE</dt>

  2805. ** <dd> ^The SQLITE_CONFIG_PAGECACHE option specifies a memory pool

  2806. ** that SQLite can use for the database page cache with the default page

  2807. ** cache implementation.  

  2808. ** This configuration option is a no-op if an application-define page

  2809. ** cache implementation is loaded using the [SQLITE_CONFIG_PCACHE2].

  2810. ** ^There are three arguments to SQLITE_CONFIG_PAGECACHE: A pointer to

  2811. ** 8-byte aligned memory (pMem), the size of each page cache line (sz),

  2812. ** and the number of cache lines (N).

  2813. ** The sz argument should be the size of the largest database page

  2814. ** (a power of two between 512 and 65536) plus some extra bytes for each

  2815. ** page header.  ^The number of extra bytes needed by the page header

  2816. ** can be determined using [SQLITE_CONFIG_PCACHE_HDRSZ].

  2817. ** ^It is harmless, apart from the wasted memory,

  2818. ** for the sz parameter to be larger than necessary.  The pMem

  2819. ** argument must be either a NULL pointer or a pointer to an 8-byte

  2820. ** aligned block of memory of at least sz*N bytes, otherwise

  2821. ** subsequent behavior is undefined.

  2822. ** ^When pMem is not NULL, SQLite will strive to use the memory provided

  2823. ** to satisfy page cache needs, falling back to [sqlite3_malloc()] if

  2824. ** a page cache line is larger than sz bytes or if all of the pMem buffer

  2825. ** is exhausted.

  2826. ** ^If pMem is NULL and N is non-zero, then each database connection

  2827. ** does an initial bulk allocation for page cache memory

  2828. ** from [sqlite3_malloc()] sufficient for N cache lines if N is positive or

  2829. ** of -1024*N bytes if N is negative, . ^If additional

  2830. ** page cache memory is needed beyond what is provided by the initial

  2831. ** allocation, then SQLite goes to [sqlite3_malloc()] separately for each

  2832. ** additional cache line. </dd>

  2833. **

  2834. ** [[SQLITE_CONFIG_HEAP]] <dt>SQLITE_CONFIG_HEAP</dt>

  2835. ** <dd> ^The SQLITE_CONFIG_HEAP option specifies a static memory buffer 

  2836. ** that SQLite will use for all of its dynamic memory allocation needs

  2837. ** beyond those provided for by [SQLITE_CONFIG_PAGECACHE].

  2838. ** ^The SQLITE_CONFIG_HEAP option is only available if SQLite is compiled

  2839. ** with either [SQLITE_ENABLE_MEMSYS3] or [SQLITE_ENABLE_MEMSYS5] and returns

  2840. ** [SQLITE_ERROR] if invoked otherwise.

  2841. ** ^There are three arguments to SQLITE_CONFIG_HEAP:

  2842. ** An 8-byte aligned pointer to the memory,

  2843. ** the number of bytes in the memory buffer, and the minimum allocation size.

  2844. ** ^If the first pointer (the memory pointer) is NULL, then SQLite reverts

  2845. ** to using its default memory allocator (the system malloc() implementation),

  2846. ** undoing any prior invocation of [SQLITE_CONFIG_MALLOC].  ^If the

  2847. ** memory pointer is not NULL then the alternative memory

  2848. ** allocator is engaged to handle all of SQLites memory allocation needs.

  2849. ** The first pointer (the memory pointer) must be aligned to an 8-byte

  2850. ** boundary or subsequent behavior of SQLite will be undefined.

  2851. ** The minimum allocation size is capped at 2**12. Reasonable values

  2852. ** for the minimum allocation size are 2**5 through 2**8.</dd>

  2853. **

  2854. ** [[SQLITE_CONFIG_MUTEX]] <dt>SQLITE_CONFIG_MUTEX</dt>

  2855. ** <dd> ^(The SQLITE_CONFIG_MUTEX option takes a single argument which is a

  2856. ** pointer to an instance of the [sqlite3_mutex_methods] structure.

  2857. ** The argument specifies alternative low-level mutex routines to be used

  2858. ** in place the mutex routines built into SQLite.)^  ^SQLite makes a copy of

  2859. ** the content of the [sqlite3_mutex_methods] structure before the call to

  2860. ** [sqlite3_config()] returns. ^If SQLite is compiled with

  2861. ** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then

  2862. ** the entire mutexing subsystem is omitted from the build and hence calls to

  2863. ** [sqlite3_config()] with the SQLITE_CONFIG_MUTEX configuration option will

  2864. ** return [SQLITE_ERROR].</dd>

  2865. **

  2866. ** [[SQLITE_CONFIG_GETMUTEX]] <dt>SQLITE_CONFIG_GETMUTEX</dt>

  2867. ** <dd> ^(The SQLITE_CONFIG_GETMUTEX option takes a single argument which

  2868. ** is a pointer to an instance of the [sqlite3_mutex_methods] structure.  The

  2869. ** [sqlite3_mutex_methods]

  2870. ** structure is filled with the currently defined mutex routines.)^

  2871. ** This option can be used to overload the default mutex allocation

  2872. ** routines with a wrapper used to track mutex usage for performance

  2873. ** profiling or testing, for example.   ^If SQLite is compiled with

  2874. ** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then

  2875. ** the entire mutexing subsystem is omitted from the build and hence calls to

  2876. ** [sqlite3_config()] with the SQLITE_CONFIG_GETMUTEX configuration option will

  2877. ** return [SQLITE_ERROR].</dd>

  2878. **

  2879. ** [[SQLITE_CONFIG_LOOKASIDE]] <dt>SQLITE_CONFIG_LOOKASIDE</dt>

  2880. ** <dd> ^(The SQLITE_CONFIG_LOOKASIDE option takes two arguments that determine

  2881. ** the default size of lookaside memory on each [database connection].

  2882. ** The first argument is the

  2883. ** size of each lookaside buffer slot and the second is the number of

  2884. ** slots allocated to each database connection.)^  ^(SQLITE_CONFIG_LOOKASIDE

  2885. ** sets the <i>default</i> lookaside size. The [SQLITE_DBCONFIG_LOOKASIDE]

  2886. ** option to [sqlite3_db_config()] can be used to change the lookaside

  2887. ** configuration on individual connections.)^ </dd>

  2888. **

  2889. ** [[SQLITE_CONFIG_PCACHE2]] <dt>SQLITE_CONFIG_PCACHE2</dt>

  2890. ** <dd> ^(The SQLITE_CONFIG_PCACHE2 option takes a single argument which is 

  2891. ** a pointer to an [sqlite3_pcache_methods2] object.  This object specifies

  2892. ** the interface to a custom page cache implementation.)^

  2893. ** ^SQLite makes a copy of the [sqlite3_pcache_methods2] object.</dd>

  2894. **

  2895. ** [[SQLITE_CONFIG_GETPCACHE2]] <dt>SQLITE_CONFIG_GETPCACHE2</dt>

  2896. ** <dd> ^(The SQLITE_CONFIG_GETPCACHE2 option takes a single argument which

  2897. ** is a pointer to an [sqlite3_pcache_methods2] object.  SQLite copies of

  2898. ** the current page cache implementation into that object.)^ </dd>

  2899. **

  2900. ** [[SQLITE_CONFIG_LOG]] <dt>SQLITE_CONFIG_LOG</dt>

  2901. ** <dd> The SQLITE_CONFIG_LOG option is used to configure the SQLite

  2902. ** global [error log].

  2903. ** (^The SQLITE_CONFIG_LOG option takes two arguments: a pointer to a

  2904. ** function with a call signature of void(*)(void*,int,const char*), 

  2905. ** and a pointer to void. ^If the function pointer is not NULL, it is

  2906. ** invoked by [sqlite3_log()] to process each logging event.  ^If the

  2907. ** function pointer is NULL, the [sqlite3_log()] interface becomes a no-op.

  2908. ** ^The void pointer that is the second argument to SQLITE_CONFIG_LOG is

  2909. ** passed through as the first parameter to the application-defined logger

  2910. ** function whenever that function is invoked.  ^The second parameter to

  2911. ** the logger function is a copy of the first parameter to the corresponding

  2912. ** [sqlite3_log()] call and is intended to be a [result code] or an

  2913. ** [extended result code].  ^The third parameter passed to the logger is

  2914. ** log message after formatting via [sqlite3_snprintf()].

  2915. ** The SQLite logging interface is not reentrant; the logger function

  2916. ** supplied by the application must not invoke any SQLite interface.

  2917. ** In a multi-threaded application, the application-defined logger

  2918. ** function must be threadsafe. </dd>

  2919. **

  2920. ** [[SQLITE_CONFIG_URI]] <dt>SQLITE_CONFIG_URI

  2921. ** <dd>^(The SQLITE_CONFIG_URI option takes a single argument of type int.

  2922. ** If non-zero, then URI handling is globally enabled. If the parameter is zero,

  2923. ** then URI handling is globally disabled.)^ ^If URI handling is globally

  2924. ** enabled, all filenames passed to [sqlite3_open()], [sqlite3_open_v2()],

  2925. ** [sqlite3_open16()] or

  2926. ** specified as part of [ATTACH] commands are interpreted as URIs, regardless

  2927. ** of whether or not the [SQLITE_OPEN_URI] flag is set when the database

  2928. ** connection is opened. ^If it is globally disabled, filenames are

  2929. ** only interpreted as URIs if the SQLITE_OPEN_URI flag is set when the

  2930. ** database connection is opened. ^(By default, URI handling is globally

  2931. ** disabled. The default value may be changed by compiling with the

  2932. ** [SQLITE_USE_URI] symbol defined.)^

  2933. **

  2934. ** [[SQLITE_CONFIG_COVERING_INDEX_SCAN]] <dt>SQLITE_CONFIG_COVERING_INDEX_SCAN

  2935. ** <dd>^The SQLITE_CONFIG_COVERING_INDEX_SCAN option takes a single integer

  2936. ** argument which is interpreted as a boolean in order to enable or disable

  2937. ** the use of covering indices for full table scans in the query optimizer.

  2938. ** ^The default setting is determined

  2939. ** by the [SQLITE_ALLOW_COVERING_INDEX_SCAN] compile-time option, or is "on"

  2940. ** if that compile-time option is omitted.

  2941. ** The ability to disable the use of covering indices for full table scans

  2942. ** is because some incorrectly coded legacy applications might malfunction

  2943. ** when the optimization is enabled.  Providing the ability to

  2944. ** disable the optimization allows the older, buggy application code to work

  2945. ** without change even with newer versions of SQLite.

  2946. **

  2947. ** [[SQLITE_CONFIG_PCACHE]] [[SQLITE_CONFIG_GETPCACHE]]

  2948. ** <dt>SQLITE_CONFIG_PCACHE and SQLITE_CONFIG_GETPCACHE

  2949. ** <dd> These options are obsolete and should not be used by new code.

  2950. ** They are retained for backwards compatibility but are now no-ops.

  2951. ** </dd>

  2952. **

  2953. ** [[SQLITE_CONFIG_SQLLOG]]

  2954. ** <dt>SQLITE_CONFIG_SQLLOG

  2955. ** <dd>This option is only available if sqlite is compiled with the

  2956. ** [SQLITE_ENABLE_SQLLOG] pre-processor macro defined. The first argument should

  2957. ** be a pointer to a function of type void(*)(void*,sqlite3*,const char*, int).

  2958. ** The second should be of type (void*). The callback is invoked by the library

  2959. ** in three separate circumstances, identified by the value passed as the

  2960. ** fourth parameter. If the fourth parameter is 0, then the database connection

  2961. ** passed as the second argument has just been opened. The third argument

  2962. ** points to a buffer containing the name of the main database file. If the

  2963. ** fourth parameter is 1, then the SQL statement that the third parameter

  2964. ** points to has just been executed. Or, if the fourth parameter is 2, then

  2965. ** the connection being passed as the second parameter is being closed. The

  2966. ** third parameter is passed NULL In this case.  An example of using this

  2967. ** configuration option can be seen in the "test_sqllog.c" source file in

  2968. ** the canonical SQLite source tree.</dd>

  2969. **

  2970. ** [[SQLITE_CONFIG_MMAP_SIZE]]

  2971. ** <dt>SQLITE_CONFIG_MMAP_SIZE

  2972. ** <dd>^SQLITE_CONFIG_MMAP_SIZE takes two 64-bit integer (sqlite3_int64) values

  2973. ** that are the default mmap size limit (the default setting for

  2974. ** [PRAGMA mmap_size]) and the maximum allowed mmap size limit.

  2975. ** ^The default setting can be overridden by each database connection using

  2976. ** either the [PRAGMA mmap_size] command, or by using the

  2977. ** [SQLITE_FCNTL_MMAP_SIZE] file control.  ^(The maximum allowed mmap size

  2978. ** will be silently truncated if necessary so that it does not exceed the

  2979. ** compile-time maximum mmap size set by the

  2980. ** [SQLITE_MAX_MMAP_SIZE] compile-time option.)^

  2981. ** ^If either argument to this option is negative, then that argument is

  2982. ** changed to its compile-time default.

  2983. **

  2984. ** [[SQLITE_CONFIG_WIN32_HEAPSIZE]]

  2985. ** <dt>SQLITE_CONFIG_WIN32_HEAPSIZE

  2986. ** <dd>^The SQLITE_CONFIG_WIN32_HEAPSIZE option is only available if SQLite is

  2987. ** compiled for Windows with the [SQLITE_WIN32_MALLOC] pre-processor macro

  2988. ** defined. ^SQLITE_CONFIG_WIN32_HEAPSIZE takes a 32-bit unsigned integer value

  2989. ** that specifies the maximum size of the created heap.

  2990. **

  2991. ** [[SQLITE_CONFIG_PCACHE_HDRSZ]]

  2992. ** <dt>SQLITE_CONFIG_PCACHE_HDRSZ

  2993. ** <dd>^The SQLITE_CONFIG_PCACHE_HDRSZ option takes a single parameter which

  2994. ** is a pointer to an integer and writes into that integer the number of extra

  2995. ** bytes per page required for each page in [SQLITE_CONFIG_PAGECACHE].

  2996. ** The amount of extra space required can change depending on the compiler,

  2997. ** target platform, and SQLite version.

  2998. **

  2999. ** [[SQLITE_CONFIG_PMASZ]]

  3000. ** <dt>SQLITE_CONFIG_PMASZ

  3001. ** <dd>^The SQLITE_CONFIG_PMASZ option takes a single parameter which

  3002. ** is an unsigned integer and sets the "Minimum PMA Size" for the multithreaded

  3003. ** sorter to that integer.  The default minimum PMA Size is set by the

  3004. ** [SQLITE_SORTER_PMASZ] compile-time option.  New threads are launched

  3005. ** to help with sort operations when multithreaded sorting

  3006. ** is enabled (using the [PRAGMA threads] command) and the amount of content

  3007. ** to be sorted exceeds the page size times the minimum of the

  3008. ** [PRAGMA cache_size] setting and this value.

  3009. **

  3010. ** [[SQLITE_CONFIG_STMTJRNL_SPILL]]

  3011. ** <dt>SQLITE_CONFIG_STMTJRNL_SPILL

  3012. ** <dd>^The SQLITE_CONFIG_STMTJRNL_SPILL option takes a single parameter which

  3013. ** becomes the [statement journal] spill-to-disk threshold.  

  3014. ** [Statement journals] are held in memory until their size (in bytes)

  3015. ** exceeds this threshold, at which point they are written to disk.

  3016. ** Or if the threshold is -1, statement journals are always held

  3017. ** exclusively in memory.

  3018. ** Since many statement journals never become large, setting the spill

  3019. ** threshold to a value such as 64KiB can greatly reduce the amount of

  3020. ** I/O required to support statement rollback.

  3021. ** The default value for this setting is controlled by the

  3022. ** [SQLITE_STMTJRNL_SPILL] compile-time option.

  3023. **

  3024. ** [[SQLITE_CONFIG_SORTERREF_SIZE]]

  3025. ** <dt>SQLITE_CONFIG_SORTERREF_SIZE

  3026. ** <dd>The SQLITE_CONFIG_SORTERREF_SIZE option accepts a single parameter

  3027. ** of type (int) - the new value of the sorter-reference size threshold.

  3028. ** Usually, when SQLite uses an external sort to order records according

  3029. ** to an ORDER BY clause, all fields required by the caller are present in the

  3030. ** sorted records. However, if SQLite determines based on the declared type

  3031. ** of a table column that its values are likely to be very large - larger

  3032. ** than the configured sorter-reference size threshold - then a reference

  3033. ** is stored in each sorted record and the required column values loaded

  3034. ** from the database as records are returned in sorted order. The default

  3035. ** value for this option is to never use this optimization. Specifying a 

  3036. ** negative value for this option restores the default behaviour.

  3037. ** This option is only available if SQLite is compiled with the

  3038. ** [SQLITE_ENABLE_SORTER_REFERENCES] compile-time option.

  3039. **

  3040. ** [[SQLITE_CONFIG_MEMDB_MAXSIZE]]

  3041. ** <dt>SQLITE_CONFIG_MEMDB_MAXSIZE

  3042. ** <dd>The SQLITE_CONFIG_MEMDB_MAXSIZE option accepts a single parameter

  3043. ** [sqlite3_int64] parameter which is the default maximum size for an in-memory

  3044. ** database created using [sqlite3_deserialize()].  This default maximum

  3045. ** size can be adjusted up or down for individual databases using the

  3046. ** [SQLITE_FCNTL_SIZE_LIMIT] [sqlite3_file_control|file-control].  If this

  3047. ** configuration setting is never used, then the default maximum is determined

  3048. ** by the [SQLITE_MEMDB_DEFAULT_MAXSIZE] compile-time option.  If that

  3049. ** compile-time option is not set, then the default maximum is 1073741824.

  3050. ** </dl>

  3051. */

  3052. #define SQLITE_CONFIG_SINGLETHREAD  1  /* nil */

  3053. #define SQLITE_CONFIG_MULTITHREAD   2  /* nil */

  3054. #define SQLITE_CONFIG_SERIALIZED    3  /* nil */

  3055. #define SQLITE_CONFIG_MALLOC        4  /* sqlite3_mem_methods* */

  3056. #define SQLITE_CONFIG_GETMALLOC     5  /* sqlite3_mem_methods* */

  3057. #define SQLITE_CONFIG_SCRATCH       6  /* No longer used */

  3058. #define SQLITE_CONFIG_PAGECACHE     7  /* void*, int sz, int N */

  3059. #define SQLITE_CONFIG_HEAP          8  /* void*, int nByte, int min */

  3060. #define SQLITE_CONFIG_MEMSTATUS     9  /* boolean */

  3061. #define SQLITE_CONFIG_MUTEX        10  /* sqlite3_mutex_methods* */

  3062. #define SQLITE_CONFIG_GETMUTEX     11  /* sqlite3_mutex_methods* */

  3063. /* previously SQLITE_CONFIG_CHUNKALLOC 12 which is now unused. */ 

  3064. #define SQLITE_CONFIG_LOOKASIDE    13  /* int int */

  3065. #define SQLITE_CONFIG_PCACHE       14  /* no-op */

  3066. #define SQLITE_CONFIG_GETPCACHE    15  /* no-op */

  3067. #define SQLITE_CONFIG_LOG          16  /* xFunc, void* */

  3068. #define SQLITE_CONFIG_URI          17  /* int */

  3069. #define SQLITE_CONFIG_PCACHE2      18  /* sqlite3_pcache_methods2* */

  3070. #define SQLITE_CONFIG_GETPCACHE2   19  /* sqlite3_pcache_methods2* */

  3071. #define SQLITE_CONFIG_COVERING_INDEX_SCAN 20  /* int */

  3072. #define SQLITE_CONFIG_SQLLOG       21  /* xSqllog, void* */

  3073. #define SQLITE_CONFIG_MMAP_SIZE    22  /* sqlite3_int64, sqlite3_int64 */

  3074. #define SQLITE_CONFIG_WIN32_HEAPSIZE      23  /* int nByte */

  3075. #define SQLITE_CONFIG_PCACHE_HDRSZ        24  /* int *psz */

  3076. #define SQLITE_CONFIG_PMASZ               25  /* unsigned int szPma */

  3077. #define SQLITE_CONFIG_STMTJRNL_SPILL      26  /* int nByte */

  3078. #define SQLITE_CONFIG_SMALL_MALLOC        27  /* boolean */

  3079. #define SQLITE_CONFIG_SORTERREF_SIZE      28  /* int nByte */

  3080. #define SQLITE_CONFIG_MEMDB_MAXSIZE       29  /* sqlite3_int64 */

  3081. 

  3082. /*

  3083. ** CAPI3REF: Database Connection Configuration Options

  3084. **

  3085. ** These constants are the available integer configuration options that

  3086. ** can be passed as the second argument to the [sqlite3_db_config()] interface.

  3087. **

  3088. ** New configuration options may be added in future releases of SQLite.

  3089. ** Existing configuration options might be discontinued.  Applications

  3090. ** should check the return code from [sqlite3_db_config()] to make sure that

  3091. ** the call worked.  ^The [sqlite3_db_config()] interface will return a

  3092. ** non-zero [error code] if a discontinued or unsupported configuration option

  3093. ** is invoked.

  3094. **

  3095. ** <dl>

  3096. ** [[SQLITE_DBCONFIG_LOOKASIDE]]

  3097. ** <dt>SQLITE_DBCONFIG_LOOKASIDE</dt>

  3098. ** <dd> ^This option takes three additional arguments that determine the 

  3099. ** [lookaside memory allocator] configuration for the [database connection].

  3100. ** ^The first argument (the third parameter to [sqlite3_db_config()] is a

  3101. ** pointer to a memory buffer to use for lookaside memory.

  3102. ** ^The first argument after the SQLITE_DBCONFIG_LOOKASIDE verb

  3103. ** may be NULL in which case SQLite will allocate the

  3104. ** lookaside buffer itself using [sqlite3_malloc()]. ^The second argument is the

  3105. ** size of each lookaside buffer slot.  ^The third argument is the number of

  3106. ** slots.  The size of the buffer in the first argument must be greater than

  3107. ** or equal to the product of the second and third arguments.  The buffer

  3108. ** must be aligned to an 8-byte boundary.  ^If the second argument to

  3109. ** SQLITE_DBCONFIG_LOOKASIDE is not a multiple of 8, it is internally

  3110. ** rounded down to the next smaller multiple of 8.  ^(The lookaside memory

  3111. ** configuration for a database connection can only be changed when that

  3112. ** connection is not currently using lookaside memory, or in other words

  3113. ** when the "current value" returned by

  3114. ** [sqlite3_db_status](D,[SQLITE_CONFIG_LOOKASIDE],...) is zero.

  3115. ** Any attempt to change the lookaside memory configuration when lookaside

  3116. ** memory is in use leaves the configuration unchanged and returns 

  3117. ** [SQLITE_BUSY].)^</dd>

  3118. **

  3119. ** [[SQLITE_DBCONFIG_ENABLE_FKEY]]

  3120. ** <dt>SQLITE_DBCONFIG_ENABLE_FKEY</dt>

  3121. ** <dd> ^This option is used to enable or disable the enforcement of

  3122. ** [foreign key constraints].  There should be two additional arguments.

  3123. ** The first argument is an integer which is 0 to disable FK enforcement,

  3124. ** positive to enable FK enforcement or negative to leave FK enforcement

  3125. ** unchanged.  The second parameter is a pointer to an integer into which

  3126. ** is written 0 or 1 to indicate whether FK enforcement is off or on

  3127. ** following this call.  The second parameter may be a NULL pointer, in

  3128. ** which case the FK enforcement setting is not reported back. </dd>

  3129. **

  3130. ** [[SQLITE_DBCONFIG_ENABLE_TRIGGER]]

  3131. ** <dt>SQLITE_DBCONFIG_ENABLE_TRIGGER</dt>

  3132. ** <dd> ^This option is used to enable or disable [CREATE TRIGGER | triggers].

  3133. ** There should be two additional arguments.

  3134. ** The first argument is an integer which is 0 to disable triggers,

  3135. ** positive to enable triggers or negative to leave the setting unchanged.

  3136. ** The second parameter is a pointer to an integer into which

  3137. ** is written 0 or 1 to indicate whether triggers are disabled or enabled

  3138. ** following this call.  The second parameter may be a NULL pointer, in

  3139. ** which case the trigger setting is not reported back. </dd>

  3140. **

  3141. ** [[SQLITE_DBCONFIG_ENABLE_FTS3_TOKENIZER]]

  3142. ** <dt>SQLITE_DBCONFIG_ENABLE_FTS3_TOKENIZER</dt>

  3143. ** <dd> ^This option is used to enable or disable the

  3144. ** [fts3_tokenizer()] function which is part of the

  3145. ** [FTS3] full-text search engine extension.

  3146. ** There should be two additional arguments.

  3147. ** The first argument is an integer which is 0 to disable fts3_tokenizer() or

  3148. ** positive to enable fts3_tokenizer() or negative to leave the setting

  3149. ** unchanged.

  3150. ** The second parameter is a pointer to an integer into which

  3151. ** is written 0 or 1 to indicate whether fts3_tokenizer is disabled or enabled

  3152. ** following this call.  The second parameter may be a NULL pointer, in

  3153. ** which case the new setting is not reported back. </dd>

  3154. **

  3155. ** [[SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION]]

  3156. ** <dt>SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION</dt>

  3157. ** <dd> ^This option is used to enable or disable the [sqlite3_load_extension()]

  3158. ** interface independently of the [load_extension()] SQL function.

  3159. ** The [sqlite3_enable_load_extension()] API enables or disables both the

  3160. ** C-API [sqlite3_load_extension()] and the SQL function [load_extension()].

  3161. ** There should be two additional arguments.

  3162. ** When the first argument to this interface is 1, then only the C-API is

  3163. ** enabled and the SQL function remains disabled.  If the first argument to

  3164. ** this interface is 0, then both the C-API and the SQL function are disabled.

  3165. ** If the first argument is -1, then no changes are made to state of either the

  3166. ** C-API or the SQL function.

  3167. ** The second parameter is a pointer to an integer into which

  3168. ** is written 0 or 1 to indicate whether [sqlite3_load_extension()] interface

  3169. ** is disabled or enabled following this call.  The second parameter may

  3170. ** be a NULL pointer, in which case the new setting is not reported back.

  3171. ** </dd>

  3172. **

  3173. ** [[SQLITE_DBCONFIG_MAINDBNAME]] <dt>SQLITE_DBCONFIG_MAINDBNAME</dt>

  3174. ** <dd> ^This option is used to change the name of the "main" database

  3175. ** schema.  ^The sole argument is a pointer to a constant UTF8 string

  3176. ** which will become the new schema name in place of "main".  ^SQLite

  3177. ** does not make a copy of the new main schema name string, so the application

  3178. ** must ensure that the argument passed into this DBCONFIG option is unchanged

  3179. ** until after the database connection closes.

  3180. ** </dd>

  3181. **

  3182. ** [[SQLITE_DBCONFIG_NO_CKPT_ON_CLOSE]] 

  3183. ** <dt>SQLITE_DBCONFIG_NO_CKPT_ON_CLOSE</dt>

  3184. ** <dd> Usually, when a database in wal mode is closed or detached from a 

  3185. ** database handle, SQLite checks if this will mean that there are now no 

  3186. ** connections at all to the database. If so, it performs a checkpoint 

  3187. ** operation before closing the connection. This option may be used to

  3188. ** override this behaviour. The first parameter passed to this operation

  3189. ** is an integer - positive to disable checkpoints-on-close, or zero (the

  3190. ** default) to enable them, and negative to leave the setting unchanged.

  3191. ** The second parameter is a pointer to an integer

  3192. ** into which is written 0 or 1 to indicate whether checkpoints-on-close

  3193. ** have been disabled - 0 if they are not disabled, 1 if they are.

  3194. ** </dd>

  3195. **

  3196. ** [[SQLITE_DBCONFIG_ENABLE_QPSG]] <dt>SQLITE_DBCONFIG_ENABLE_QPSG</dt>

  3197. ** <dd>^(The SQLITE_DBCONFIG_ENABLE_QPSG option activates or deactivates

  3198. ** the [query planner stability guarantee] (QPSG).  When the QPSG is active,

  3199. ** a single SQL query statement will always use the same algorithm regardless

  3200. ** of values of [bound parameters].)^ The QPSG disables some query optimizations

  3201. ** that look at the values of bound parameters, which can make some queries

  3202. ** slower.  But the QPSG has the advantage of more predictable behavior.  With

  3203. ** the QPSG active, SQLite will always use the same query plan in the field as

  3204. ** was used during testing in the lab.

  3205. ** The first argument to this setting is an integer which is 0 to disable 

  3206. ** the QPSG, positive to enable QPSG, or negative to leave the setting

  3207. ** unchanged. The second parameter is a pointer to an integer into which

  3208. ** is written 0 or 1 to indicate whether the QPSG is disabled or enabled

  3209. ** following this call.

  3210. ** </dd>

  3211. **

  3212. ** [[SQLITE_DBCONFIG_TRIGGER_EQP]] <dt>SQLITE_DBCONFIG_TRIGGER_EQP</dt>

  3213. ** <dd> By default, the output of EXPLAIN QUERY PLAN commands does not 

  3214. ** include output for any operations performed by trigger programs. This

  3215. ** option is used to set or clear (the default) a flag that governs this

  3216. ** behavior. The first parameter passed to this operation is an integer -

  3217. ** positive to enable output for trigger programs, or zero to disable it,

  3218. ** or negative to leave the setting unchanged.

  3219. ** The second parameter is a pointer to an integer into which is written 

  3220. ** 0 or 1 to indicate whether output-for-triggers has been disabled - 0 if 

  3221. ** it is not disabled, 1 if it is.  

  3222. ** </dd>

  3223. **

  3224. ** [[SQLITE_DBCONFIG_RESET_DATABASE]] <dt>SQLITE_DBCONFIG_RESET_DATABASE</dt>

  3225. ** <dd> Set the SQLITE_DBCONFIG_RESET_DATABASE flag and then run

  3226. ** [VACUUM] in order to reset a database back to an empty database

  3227. ** with no schema and no content. The following process works even for

  3228. ** a badly corrupted database file:

  3229. ** <ol>

  3230. ** <li> If the database connection is newly opened, make sure it has read the

  3231. **      database schema by preparing then discarding some query against the

  3232. **      database, or calling sqlite3_table_column_metadata(), ignoring any

  3233. **      errors.  This step is only necessary if the application desires to keep

  3234. **      the database in WAL mode after the reset if it was in WAL mode before

  3235. **      the reset.  

  3236. ** <li> sqlite3_db_config(db, SQLITE_DBCONFIG_RESET_DATABASE, 1, 0);

  3237. ** <li> [sqlite3_exec](db, "[VACUUM]", 0, 0, 0);

  3238. ** <li> sqlite3_db_config(db, SQLITE_DBCONFIG_RESET_DATABASE, 0, 0);

  3239. ** </ol>

  3240. ** Because resetting a database is destructive and irreversible, the

  3241. ** process requires the use of this obscure API and multiple steps to help

  3242. ** ensure that it does not happen by accident.

  3243. **

  3244. ** [[SQLITE_DBCONFIG_DEFENSIVE]] <dt>SQLITE_DBCONFIG_DEFENSIVE</dt>

  3245. ** <dd>The SQLITE_DBCONFIG_DEFENSIVE option activates or deactivates the

  3246. ** "defensive" flag for a database connection.  When the defensive

  3247. ** flag is enabled, language features that allow ordinary SQL to 

  3248. ** deliberately corrupt the database file are disabled.  The disabled

  3249. ** features include but are not limited to the following:

  3250. ** <ul>

  3251. ** <li> The [PRAGMA writable_schema=ON] statement.

  3252. ** <li> The [PRAGMA journal_mode=OFF] statement.

  3253. ** <li> Writes to the [sqlite_dbpage] virtual table.

  3254. ** <li> Direct writes to [shadow tables].

  3255. ** </ul>

  3256. ** </dd>

  3257. **

  3258. ** [[SQLITE_DBCONFIG_WRITABLE_SCHEMA]] <dt>SQLITE_DBCONFIG_WRITABLE_SCHEMA</dt>

  3259. ** <dd>The SQLITE_DBCONFIG_WRITABLE_SCHEMA option activates or deactivates the

  3260. ** "writable_schema" flag. This has the same effect and is logically equivalent

  3261. ** to setting [PRAGMA writable_schema=ON] or [PRAGMA writable_schema=OFF].

  3262. ** The first argument to this setting is an integer which is 0 to disable 

  3263. ** the writable_schema, positive to enable writable_schema, or negative to

  3264. ** leave the setting unchanged. The second parameter is a pointer to an

  3265. ** integer into which is written 0 or 1 to indicate whether the writable_schema

  3266. ** is enabled or disabled following this call.

  3267. ** </dd>

  3268. **

  3269. ** [[SQLITE_DBCONFIG_LEGACY_ALTER_TABLE]]

  3270. ** <dt>SQLITE_DBCONFIG_LEGACY_ALTER_TABLE</dt>

  3271. ** <dd>The SQLITE_DBCONFIG_LEGACY_ALTER_TABLE option activates or deactivates

  3272. ** the legacy behavior of the [ALTER TABLE RENAME] command such it

  3273. ** behaves as it did prior to [version 3.24.0] (2018-06-04).  See the

  3274. ** "Compatibility Notice" on the [ALTER TABLE RENAME documentation] for

  3275. ** additional information. This feature can also be turned on and off

  3276. ** using the [PRAGMA legacy_alter_table] statement.

  3277. ** </dd>

  3278. **

  3279. ** [[SQLITE_DBCONFIG_DQS_DML]]

  3280. ** <dt>SQLITE_DBCONFIG_DQS_DML</td>

  3281. ** <dd>The SQLITE_DBCONFIG_DQS_DML option activates or deactivates

  3282. ** the legacy [double-quoted string literal] misfeature for DML statement

  3283. ** only, that is DELETE, INSERT, SELECT, and UPDATE statements. The

  3284. ** default value of this setting is determined by the [-DSQLITE_DQS]

  3285. ** compile-time option.

  3286. ** </dd>

  3287. **

  3288. ** [[SQLITE_DBCONFIG_DQS_DDL]]

  3289. ** <dt>SQLITE_DBCONFIG_DQS_DDL</td>

  3290. ** <dd>The SQLITE_DBCONFIG_DQS option activates or deactivates

  3291. ** the legacy [double-quoted string literal] misfeature for DDL statements,

  3292. ** such as CREATE TABLE and CREATE INDEX. The

  3293. ** default value of this setting is determined by the [-DSQLITE_DQS]

  3294. ** compile-time option.

  3295. ** </dd>

  3296. ** </dl>

  3297. */

  3298. #define SQLITE_DBCONFIG_MAINDBNAME            1000 /* const char* */

  3299. #define SQLITE_DBCONFIG_LOOKASIDE             1001 /* void* int int */

  3300. #define SQLITE_DBCONFIG_ENABLE_FKEY           1002 /* int int* */

  3301. #define SQLITE_DBCONFIG_ENABLE_TRIGGER        1003 /* int int* */

  3302. #define SQLITE_DBCONFIG_ENABLE_FTS3_TOKENIZER 1004 /* int int* */

  3303. #define SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION 1005 /* int int* */

  3304. #define SQLITE_DBCONFIG_NO_CKPT_ON_CLOSE      1006 /* int int* */

  3305. #define SQLITE_DBCONFIG_ENABLE_QPSG           1007 /* int int* */

  3306. #define SQLITE_DBCONFIG_TRIGGER_EQP           1008 /* int int* */

  3307. #define SQLITE_DBCONFIG_RESET_DATABASE        1009 /* int int* */

  3308. #define SQLITE_DBCONFIG_DEFENSIVE             1010 /* int int* */

  3309. #define SQLITE_DBCONFIG_WRITABLE_SCHEMA       1011 /* int int* */

  3310. #define SQLITE_DBCONFIG_LEGACY_ALTER_TABLE    1012 /* int int* */

  3311. #define SQLITE_DBCONFIG_DQS_DML               1013 /* int int* */

  3312. #define SQLITE_DBCONFIG_DQS_DDL               1014 /* int int* */

  3313. #define SQLITE_DBCONFIG_MAX                   1014 /* Largest DBCONFIG */

  3314. 

  3315. /*

  3316. ** CAPI3REF: Enable Or Disable Extended Result Codes

  3317. ** METHOD: sqlite3

  3318. **

  3319. ** ^The sqlite3_extended_result_codes() routine enables or disables the

  3320. ** [extended result codes] feature of SQLite. ^The extended result

  3321. ** codes are disabled by default for historical compatibility.

  3322. */

  3323. SQLITE_API int sqlite3_extended_result_codes(sqlite3*, int onoff);

  3324. 

  3325. /*

  3326. ** CAPI3REF: Last Insert Rowid

  3327. ** METHOD: sqlite3

  3328. **

  3329. ** ^Each entry in most SQLite tables (except for [WITHOUT ROWID] tables)

  3330. ** has a unique 64-bit signed

  3331. ** integer key called the [ROWID | "rowid"]. ^The rowid is always available

  3332. ** as an undeclared column named ROWID, OID, or _ROWID_ as long as those

  3333. ** names are not also used by explicitly declared columns. ^If

  3334. ** the table has a column of type [INTEGER PRIMARY KEY] then that column

  3335. ** is another alias for the rowid.

  3336. **

  3337. ** ^The sqlite3_last_insert_rowid(D) interface usually returns the [rowid] of

  3338. ** the most recent successful [INSERT] into a rowid table or [virtual table]

  3339. ** on database connection D. ^Inserts into [WITHOUT ROWID] tables are not

  3340. ** recorded. ^If no successful [INSERT]s into rowid tables have ever occurred 

  3341. ** on the database connection D, then sqlite3_last_insert_rowid(D) returns 

  3342. ** zero.

  3343. **

  3344. ** As well as being set automatically as rows are inserted into database

  3345. ** tables, the value returned by this function may be set explicitly by

  3346. ** [sqlite3_set_last_insert_rowid()]

  3347. **

  3348. ** Some virtual table implementations may INSERT rows into rowid tables as

  3349. ** part of committing a transaction (e.g. to flush data accumulated in memory

  3350. ** to disk). In this case subsequent calls to this function return the rowid

  3351. ** associated with these internal INSERT operations, which leads to 

  3352. ** unintuitive results. Virtual table implementations that do write to rowid

  3353. ** tables in this way can avoid this problem by restoring the original 

  3354. ** rowid value using [sqlite3_set_last_insert_rowid()] before returning 

  3355. ** control to the user.

  3356. **

  3357. ** ^(If an [INSERT] occurs within a trigger then this routine will 

  3358. ** return the [rowid] of the inserted row as long as the trigger is 

  3359. ** running. Once the trigger program ends, the value returned 

  3360. ** by this routine reverts to what it was before the trigger was fired.)^

  3361. **

  3362. ** ^An [INSERT] that fails due to a constraint violation is not a

  3363. ** successful [INSERT] and does not change the value returned by this

  3364. ** routine.  ^Thus INSERT OR FAIL, INSERT OR IGNORE, INSERT OR ROLLBACK,

  3365. ** and INSERT OR ABORT make no changes to the return value of this

  3366. ** routine when their insertion fails.  ^(When INSERT OR REPLACE

  3367. ** encounters a constraint violation, it does not fail.  The

  3368. ** INSERT continues to completion after deleting rows that caused

  3369. ** the constraint problem so INSERT OR REPLACE will always change

  3370. ** the return value of this interface.)^

  3371. **

  3372. ** ^For the purposes of this routine, an [INSERT] is considered to

  3373. ** be successful even if it is subsequently rolled back.

  3374. **

  3375. ** This function is accessible to SQL statements via the

  3376. ** [last_insert_rowid() SQL function].

  3377. **

  3378. ** If a separate thread performs a new [INSERT] on the same

  3379. ** database connection while the [sqlite3_last_insert_rowid()]

  3380. ** function is running and thus changes the last insert [rowid],

  3381. ** then the value returned by [sqlite3_last_insert_rowid()] is

  3382. ** unpredictable and might not equal either the old or the new

  3383. ** last insert [rowid].

  3384. */

  3385. SQLITE_API sqlite3_int64 sqlite3_last_insert_rowid(sqlite3*);

  3386. 

  3387. /*

  3388. ** CAPI3REF: Set the Last Insert Rowid value.

  3389. ** METHOD: sqlite3

  3390. **

  3391. ** The sqlite3_set_last_insert_rowid(D, R) method allows the application to

  3392. ** set the value returned by calling sqlite3_last_insert_rowid(D) to R 

  3393. ** without inserting a row into the database.

  3394. */

  3395. SQLITE_API void sqlite3_set_last_insert_rowid(sqlite3*,sqlite3_int64);

  3396. 

  3397. /*

  3398. ** CAPI3REF: Count The Number Of Rows Modified

  3399. ** METHOD: sqlite3

  3400. **

  3401. ** ^This function returns the number of rows modified, inserted or

  3402. ** deleted by the most recently completed INSERT, UPDATE or DELETE

  3403. ** statement on the database connection specified by the only parameter.

  3404. ** ^Executing any other type of SQL statement does not modify the value

  3405. ** returned by this function.

  3406. **

  3407. ** ^Only changes made directly by the INSERT, UPDATE or DELETE statement are

  3408. ** considered - auxiliary changes caused by [CREATE TRIGGER | triggers], 

  3409. ** [foreign key actions] or [REPLACE] constraint resolution are not counted.

  3410. ** 

  3411. ** Changes to a view that are intercepted by 

  3412. ** [INSTEAD OF trigger | INSTEAD OF triggers] are not counted. ^The value 

  3413. ** returned by sqlite3_changes() immediately after an INSERT, UPDATE or 

  3414. ** DELETE statement run on a view is always zero. Only changes made to real 

  3415. ** tables are counted.

  3416. **

  3417. ** Things are more complicated if the sqlite3_changes() function is

  3418. ** executed while a trigger program is running. This may happen if the

  3419. ** program uses the [changes() SQL function], or if some other callback

  3420. ** function invokes sqlite3_changes() directly. Essentially:

  3421. ** 

  3422. ** <ul>

  3423. **   <li> ^(Before entering a trigger program the value returned by

  3424. **        sqlite3_changes() function is saved. After the trigger program 

  3425. **        has finished, the original value is restored.)^

  3426. ** 

  3427. **   <li> ^(Within a trigger program each INSERT, UPDATE and DELETE 

  3428. **        statement sets the value returned by sqlite3_changes() 

  3429. **        upon completion as normal. Of course, this value will not include 

  3430. **        any changes performed by sub-triggers, as the sqlite3_changes() 

  3431. **        value will be saved and restored after each sub-trigger has run.)^

  3432. ** </ul>

  3433. ** 

  3434. ** ^This means that if the changes() SQL function (or similar) is used

  3435. ** by the first INSERT, UPDATE or DELETE statement within a trigger, it 

  3436. ** returns the value as set when the calling statement began executing.

  3437. ** ^If it is used by the second or subsequent such statement within a trigger 

  3438. ** program, the value returned reflects the number of rows modified by the 

  3439. ** previous INSERT, UPDATE or DELETE statement within the same trigger.

  3440. **

  3441. ** If a separate thread makes changes on the same database connection

  3442. ** while [sqlite3_changes()] is running then the value returned

  3443. ** is unpredictable and not meaningful.

  3444. **

  3445. ** See also:

  3446. ** <ul>

  3447. ** <li> the [sqlite3_total_changes()] interface

  3448. ** <li> the [count_changes pragma]

  3449. ** <li> the [changes() SQL function]

  3450. ** <li> the [data_version pragma]

  3451. ** </ul>

  3452. */

  3453. SQLITE_API int sqlite3_changes(sqlite3*);

  3454. 

  3455. /*

  3456. ** CAPI3REF: Total Number Of Rows Modified

  3457. ** METHOD: sqlite3

  3458. **

  3459. ** ^This function returns the total number of rows inserted, modified or

  3460. ** deleted by all [INSERT], [UPDATE] or [DELETE] statements completed

  3461. ** since the database connection was opened, including those executed as

  3462. ** part of trigger programs. ^Executing any other type of SQL statement

  3463. ** does not affect the value returned by sqlite3_total_changes().

  3464. ** 

  3465. ** ^Changes made as part of [foreign key actions] are included in the

  3466. ** count, but those made as part of REPLACE constraint resolution are

  3467. ** not. ^Changes to a view that are intercepted by INSTEAD OF triggers 

  3468. ** are not counted.

  3469. **

  3470. ** The [sqlite3_total_changes(D)] interface only reports the number

  3471. ** of rows that changed due to SQL statement run against database

  3472. ** connection D.  Any changes by other database connections are ignored.

  3473. ** To detect changes against a database file from other database

  3474. ** connections use the [PRAGMA data_version] command or the

  3475. ** [SQLITE_FCNTL_DATA_VERSION] [file control].

  3476. ** 

  3477. ** If a separate thread makes changes on the same database connection

  3478. ** while [sqlite3_total_changes()] is running then the value

  3479. ** returned is unpredictable and not meaningful.

  3480. **

  3481. ** See also:

  3482. ** <ul>

  3483. ** <li> the [sqlite3_changes()] interface

  3484. ** <li> the [count_changes pragma]

  3485. ** <li> the [changes() SQL function]

  3486. ** <li> the [data_version pragma]

  3487. ** <li> the [SQLITE_FCNTL_DATA_VERSION] [file control]

  3488. ** </ul>

  3489. */

  3490. SQLITE_API int sqlite3_total_changes(sqlite3*);

  3491. 

  3492. /*

  3493. ** CAPI3REF: Interrupt A Long-Running Query

  3494. ** METHOD: sqlite3

  3495. **

  3496. ** ^This function causes any pending database operation to abort and

  3497. ** return at its earliest opportunity. This routine is typically

  3498. ** called in response to a user action such as pressing "Cancel"

  3499. ** or Ctrl-C where the user wants a long query operation to halt

  3500. ** immediately.

  3501. **

  3502. ** ^It is safe to call this routine from a thread different from the

  3503. ** thread that is currently running the database operation.  But it

  3504. ** is not safe to call this routine with a [database connection] that

  3505. ** is closed or might close before sqlite3_interrupt() returns.

  3506. **

  3507. ** ^If an SQL operation is very nearly finished at the time when

  3508. ** sqlite3_interrupt() is called, then it might not have an opportunity

  3509. ** to be interrupted and might continue to completion.

  3510. **

  3511. ** ^An SQL operation that is interrupted will return [SQLITE_INTERRUPT].

  3512. ** ^If the interrupted SQL operation is an INSERT, UPDATE, or DELETE

  3513. ** that is inside an explicit transaction, then the entire transaction

  3514. ** will be rolled back automatically.

  3515. **

  3516. ** ^The sqlite3_interrupt(D) call is in effect until all currently running

  3517. ** SQL statements on [database connection] D complete.  ^Any new SQL statements

  3518. ** that are started after the sqlite3_interrupt() call and before the 

  3519. ** running statements reaches zero are interrupted as if they had been

  3520. ** running prior to the sqlite3_interrupt() call.  ^New SQL statements

  3521. ** that are started after the running statement count reaches zero are

  3522. ** not effected by the sqlite3_interrupt().

  3523. ** ^A call to sqlite3_interrupt(D) that occurs when there are no running

  3524. ** SQL statements is a no-op and has no effect on SQL statements

  3525. ** that are started after the sqlite3_interrupt() call returns.

  3526. */

  3527. SQLITE_API void sqlite3_interrupt(sqlite3*);

  3528. 

  3529. /*

  3530. ** CAPI3REF: Determine If An SQL Statement Is Complete

  3531. **

  3532. ** These routines are useful during command-line input to determine if the

  3533. ** currently entered text seems to form a complete SQL statement or

  3534. ** if additional input is needed before sending the text into

  3535. ** SQLite for parsing.  ^These routines return 1 if the input string

  3536. ** appears to be a complete SQL statement.  ^A statement is judged to be

  3537. ** complete if it ends with a semicolon token and is not a prefix of a

  3538. ** well-formed CREATE TRIGGER statement.  ^Semicolons that are embedded within

  3539. ** string literals or quoted identifier names or comments are not

  3540. ** independent tokens (they are part of the token in which they are

  3541. ** embedded) and thus do not count as a statement terminator.  ^Whitespace

  3542. ** and comments that follow the final semicolon are ignored.

  3543. **

  3544. ** ^These routines return 0 if the statement is incomplete.  ^If a

  3545. ** memory allocation fails, then SQLITE_NOMEM is returned.

  3546. **

  3547. ** ^These routines do not parse the SQL statements thus

  3548. ** will not detect syntactically incorrect SQL.

  3549. **

  3550. ** ^(If SQLite has not been initialized using [sqlite3_initialize()] prior 

  3551. ** to invoking sqlite3_complete16() then sqlite3_initialize() is invoked

  3552. ** automatically by sqlite3_complete16().  If that initialization fails,

  3553. ** then the return value from sqlite3_complete16() will be non-zero

  3554. ** regardless of whether or not the input SQL is complete.)^

  3555. **

  3556. ** The input to [sqlite3_complete()] must be a zero-terminated

  3557. ** UTF-8 string.

  3558. **

  3559. ** The input to [sqlite3_complete16()] must be a zero-terminated

  3560. ** UTF-16 string in native byte order.

  3561. */

  3562. SQLITE_API int sqlite3_complete(const char *sql);

  3563. SQLITE_API int sqlite3_complete16(const void *sql);

  3564. 

  3565. /*

  3566. ** CAPI3REF: Register A Callback To Handle SQLITE_BUSY Errors

  3567. ** KEYWORDS: {busy-handler callback} {busy handler}

  3568. ** METHOD: sqlite3

  3569. **

  3570. ** ^The sqlite3_busy_handler(D,X,P) routine sets a callback function X

  3571. ** that might be invoked with argument P whenever

  3572. ** an attempt is made to access a database table associated with

  3573. ** [database connection] D when another thread

  3574. ** or process has the table locked.

  3575. ** The sqlite3_busy_handler() interface is used to implement

  3576. ** [sqlite3_busy_timeout()] and [PRAGMA busy_timeout].

  3577. **

  3578. ** ^If the busy callback is NULL, then [SQLITE_BUSY]

  3579. ** is returned immediately upon encountering the lock.  ^If the busy callback

  3580. ** is not NULL, then the callback might be invoked with two arguments.

  3581. **

  3582. ** ^The first argument to the busy handler is a copy of the void* pointer which

  3583. ** is the third argument to sqlite3_busy_handler().  ^The second argument to

  3584. ** the busy handler callback is the number of times that the busy handler has

  3585. ** been invoked previously for the same locking event.  ^If the

  3586. ** busy callback returns 0, then no additional attempts are made to

  3587. ** access the database and [SQLITE_BUSY] is returned

  3588. ** to the application.

  3589. ** ^If the callback returns non-zero, then another attempt

  3590. ** is made to access the database and the cycle repeats.

  3591. **

  3592. ** The presence of a busy handler does not guarantee that it will be invoked

  3593. ** when there is lock contention. ^If SQLite determines that invoking the busy

  3594. ** handler could result in a deadlock, it will go ahead and return [SQLITE_BUSY]

  3595. ** to the application instead of invoking the 

  3596. ** busy handler.

  3597. ** Consider a scenario where one process is holding a read lock that

  3598. ** it is trying to promote to a reserved lock and

  3599. ** a second process is holding a reserved lock that it is trying

  3600. ** to promote to an exclusive lock.  The first process cannot proceed

  3601. ** because it is blocked by the second and the second process cannot

  3602. ** proceed because it is blocked by the first.  If both processes

  3603. ** invoke the busy handlers, neither will make any progress.  Therefore,

  3604. ** SQLite returns [SQLITE_BUSY] for the first process, hoping that this

  3605. ** will induce the first process to release its read lock and allow

  3606. ** the second process to proceed.

  3607. **

  3608. ** ^The default busy callback is NULL.

  3609. **

  3610. ** ^(There can only be a single busy handler defined for each

  3611. ** [database connection].  Setting a new busy handler clears any

  3612. ** previously set handler.)^  ^Note that calling [sqlite3_busy_timeout()]

  3613. ** or evaluating [PRAGMA busy_timeout=N] will change the

  3614. ** busy handler and thus clear any previously set busy handler.

  3615. **

  3616. ** The busy callback should not take any actions which modify the

  3617. ** database connection that invoked the busy handler.  In other words,

  3618. ** the busy handler is not reentrant.  Any such actions

  3619. ** result in undefined behavior.

  3620. ** 

  3621. ** A busy handler must not close the database connection

  3622. ** or [prepared statement] that invoked the busy handler.

  3623. */

  3624. SQLITE_API int sqlite3_busy_handler(sqlite3*,int(*)(void*,int),void*);

  3625. 

  3626. /*

  3627. ** CAPI3REF: Set A Busy Timeout

  3628. ** METHOD: sqlite3

  3629. **

  3630. ** ^This routine sets a [sqlite3_busy_handler | busy handler] that sleeps

  3631. ** for a specified amount of time when a table is locked.  ^The handler

  3632. ** will sleep multiple times until at least "ms" milliseconds of sleeping

  3633. ** have accumulated.  ^After at least "ms" milliseconds of sleeping,

  3634. ** the handler returns 0 which causes [sqlite3_step()] to return

  3635. ** [SQLITE_BUSY].

  3636. **

  3637. ** ^Calling this routine with an argument less than or equal to zero

  3638. ** turns off all busy handlers.

  3639. **

  3640. ** ^(There can only be a single busy handler for a particular

  3641. ** [database connection] at any given moment.  If another busy handler

  3642. ** was defined  (using [sqlite3_busy_handler()]) prior to calling

  3643. ** this routine, that other busy handler is cleared.)^

  3644. **

  3645. ** See also:  [PRAGMA busy_timeout]

  3646. */

  3647. SQLITE_API int sqlite3_busy_timeout(sqlite3*, int ms);

  3648. 

  3649. /*

  3650. ** CAPI3REF: Convenience Routines For Running Queries

  3651. ** METHOD: sqlite3

  3652. **

  3653. ** This is a legacy interface that is preserved for backwards compatibility.

  3654. ** Use of this interface is not recommended.

  3655. **

  3656. ** Definition: A <b>result table</b> is memory data structure created by the

  3657. ** [sqlite3_get_table()] interface.  A result table records the

  3658. ** complete query results from one or more queries.

  3659. **

  3660. ** The table conceptually has a number of rows and columns.  But

  3661. ** these numbers are not part of the result table itself.  These

  3662. ** numbers are obtained separately.  Let N be the number of rows

  3663. ** and M be the number of columns.

  3664. **

  3665. ** A result table is an array of pointers to zero-terminated UTF-8 strings.

  3666. ** There are (N+1)*M elements in the array.  The first M pointers point

  3667. ** to zero-terminated strings that  contain the names of the columns.

  3668. ** The remaining entries all point to query results.  NULL values result

  3669. ** in NULL pointers.  All other values are in their UTF-8 zero-terminated

  3670. ** string representation as returned by [sqlite3_column_text()].

  3671. **

  3672. ** A result table might consist of one or more memory allocations.

  3673. ** It is not safe to pass a result table directly to [sqlite3_free()].

  3674. ** A result table should be deallocated using [sqlite3_free_table()].

  3675. **

  3676. ** ^(As an example of the result table format, suppose a query result

  3677. ** is as follows:

  3678. **

  3679. ** <blockquote><pre>

  3680. **        Name        | Age

  3681. **        -----------------------

  3682. **        Alice       | 43

  3683. **        Bob         | 28

  3684. **        Cindy       | 21

  3685. ** </pre></blockquote>

  3686. **

  3687. ** There are two column (M==2) and three rows (N==3).  Thus the

  3688. ** result table has 8 entries.  Suppose the result table is stored

  3689. ** in an array names azResult.  Then azResult holds this content:

  3690. **

  3691. ** <blockquote><pre>

  3692. **        azResult&#91;0] = "Name";

  3693. **        azResult&#91;1] = "Age";

  3694. **        azResult&#91;2] = "Alice";

  3695. **        azResult&#91;3] = "43";

  3696. **        azResult&#91;4] = "Bob";

  3697. **        azResult&#91;5] = "28";

  3698. **        azResult&#91;6] = "Cindy";

  3699. **        azResult&#91;7] = "21";

  3700. ** </pre></blockquote>)^

  3701. **

  3702. ** ^The sqlite3_get_table() function evaluates one or more

  3703. ** semicolon-separated SQL statements in the zero-terminated UTF-8

  3704. ** string of its 2nd parameter and returns a result table to the

  3705. ** pointer given in its 3rd parameter.

  3706. **

  3707. ** After the application has finished with the result from sqlite3_get_table(),

  3708. ** it must pass the result table pointer to sqlite3_free_table() in order to

  3709. ** release the memory that was malloced.  Because of the way the

  3710. ** [sqlite3_malloc()] happens within sqlite3_get_table(), the calling

  3711. ** function must not try to call [sqlite3_free()] directly.  Only

  3712. ** [sqlite3_free_table()] is able to release the memory properly and safely.

  3713. **

  3714. ** The sqlite3_get_table() interface is implemented as a wrapper around

  3715. ** [sqlite3_exec()].  The sqlite3_get_table() routine does not have access

  3716. ** to any internal data structures of SQLite.  It uses only the public

  3717. ** interface defined here.  As a consequence, errors that occur in the

  3718. ** wrapper layer outside of the internal [sqlite3_exec()] call are not

  3719. ** reflected in subsequent calls to [sqlite3_errcode()] or

  3720. ** [sqlite3_errmsg()].

  3721. */

  3722. SQLITE_API int sqlite3_get_table(

  3723.   sqlite3 *db,          /* An open database */

  3724.   const char *zSql,     /* SQL to be evaluated */

  3725.   char ***pazResult,    /* Results of the query */

  3726.   int *pnRow,           /* Number of result rows written here */

  3727.   int *pnColumn,        /* Number of result columns written here */

  3728.   char **pzErrmsg       /* Error msg written here */

  3729. );

  3730. SQLITE_API void sqlite3_free_table(char **result);

  3731. 

  3732. /*

  3733. ** CAPI3REF: Formatted String Printing Functions

  3734. **

  3735. ** These routines are work-alikes of the "printf()" family of functions

  3736. ** from the standard C library.

  3737. ** These routines understand most of the common formatting options from

  3738. ** the standard library printf() 

  3739. ** plus some additional non-standard formats ([%q], [%Q], [%w], and [%z]).

  3740. ** See the [built-in printf()] documentation for details.

  3741. **

  3742. ** ^The sqlite3_mprintf() and sqlite3_vmprintf() routines write their

  3743. ** results into memory obtained from [sqlite3_malloc64()].

  3744. ** The strings returned by these two routines should be

  3745. ** released by [sqlite3_free()].  ^Both routines return a

  3746. ** NULL pointer if [sqlite3_malloc64()] is unable to allocate enough

  3747. ** memory to hold the resulting string.

  3748. **

  3749. ** ^(The sqlite3_snprintf() routine is similar to "snprintf()" from

  3750. ** the standard C library.  The result is written into the

  3751. ** buffer supplied as the second parameter whose size is given by

  3752. ** the first parameter. Note that the order of the

  3753. ** first two parameters is reversed from snprintf().)^  This is an

  3754. ** historical accident that cannot be fixed without breaking

  3755. ** backwards compatibility.  ^(Note also that sqlite3_snprintf()

  3756. ** returns a pointer to its buffer instead of the number of

  3757. ** characters actually written into the buffer.)^  We admit that

  3758. ** the number of characters written would be a more useful return

  3759. ** value but we cannot change the implementation of sqlite3_snprintf()

  3760. ** now without breaking compatibility.

  3761. **

  3762. ** ^As long as the buffer size is greater than zero, sqlite3_snprintf()

  3763. ** guarantees that the buffer is always zero-terminated.  ^The first

  3764. ** parameter "n" is the total size of the buffer, including space for

  3765. ** the zero terminator.  So the longest string that can be completely

  3766. ** written will be n-1 characters.

  3767. **

  3768. ** ^The sqlite3_vsnprintf() routine is a varargs version of sqlite3_snprintf().

  3769. **

  3770. ** See also:  [built-in printf()], [printf() SQL function]

  3771. */

  3772. SQLITE_API char *sqlite3_mprintf(const char*,...);

  3773. SQLITE_API char *sqlite3_vmprintf(const char*, va_list);

  3774. SQLITE_API char *sqlite3_snprintf(int,char*,const char*, ...);

  3775. SQLITE_API char *sqlite3_vsnprintf(int,char*,const char*, va_list);

  3776. 

  3777. /*

  3778. ** CAPI3REF: Memory Allocation Subsystem

  3779. **

  3780. ** The SQLite core uses these three routines for all of its own

  3781. ** internal memory allocation needs. "Core" in the previous sentence

  3782. ** does not include operating-system specific VFS implementation.  The

  3783. ** Windows VFS uses native malloc() and free() for some operations.

  3784. **

  3785. ** ^The sqlite3_malloc() routine returns a pointer to a block

  3786. ** of memory at least N bytes in length, where N is the parameter.

  3787. ** ^If sqlite3_malloc() is unable to obtain sufficient free

  3788. ** memory, it returns a NULL pointer.  ^If the parameter N to

  3789. ** sqlite3_malloc() is zero or negative then sqlite3_malloc() returns

  3790. ** a NULL pointer.

  3791. **

  3792. ** ^The sqlite3_malloc64(N) routine works just like

  3793. ** sqlite3_malloc(N) except that N is an unsigned 64-bit integer instead

  3794. ** of a signed 32-bit integer.

  3795. **

  3796. ** ^Calling sqlite3_free() with a pointer previously returned

  3797. ** by sqlite3_malloc() or sqlite3_realloc() releases that memory so

  3798. ** that it might be reused.  ^The sqlite3_free() routine is

  3799. ** a no-op if is called with a NULL pointer.  Passing a NULL pointer

  3800. ** to sqlite3_free() is harmless.  After being freed, memory

  3801. ** should neither be read nor written.  Even reading previously freed

  3802. ** memory might result in a segmentation fault or other severe error.

  3803. ** Memory corruption, a segmentation fault, or other severe error

  3804. ** might result if sqlite3_free() is called with a non-NULL pointer that

  3805. ** was not obtained from sqlite3_malloc() or sqlite3_realloc().

  3806. **

  3807. ** ^The sqlite3_realloc(X,N) interface attempts to resize a

  3808. ** prior memory allocation X to be at least N bytes.

  3809. ** ^If the X parameter to sqlite3_realloc(X,N)

  3810. ** is a NULL pointer then its behavior is identical to calling

  3811. ** sqlite3_malloc(N).

  3812. ** ^If the N parameter to sqlite3_realloc(X,N) is zero or

  3813. ** negative then the behavior is exactly the same as calling

  3814. ** sqlite3_free(X).

  3815. ** ^sqlite3_realloc(X,N) returns a pointer to a memory allocation

  3816. ** of at least N bytes in size or NULL if insufficient memory is available.

  3817. ** ^If M is the size of the prior allocation, then min(N,M) bytes

  3818. ** of the prior allocation are copied into the beginning of buffer returned

  3819. ** by sqlite3_realloc(X,N) and the prior allocation is freed.

  3820. ** ^If sqlite3_realloc(X,N) returns NULL and N is positive, then the

  3821. ** prior allocation is not freed.

  3822. **

  3823. ** ^The sqlite3_realloc64(X,N) interfaces works the same as

  3824. ** sqlite3_realloc(X,N) except that N is a 64-bit unsigned integer instead

  3825. ** of a 32-bit signed integer.

  3826. **

  3827. ** ^If X is a memory allocation previously obtained from sqlite3_malloc(),

  3828. ** sqlite3_malloc64(), sqlite3_realloc(), or sqlite3_realloc64(), then

  3829. ** sqlite3_msize(X) returns the size of that memory allocation in bytes.

  3830. ** ^The value returned by sqlite3_msize(X) might be larger than the number

  3831. ** of bytes requested when X was allocated.  ^If X is a NULL pointer then

  3832. ** sqlite3_msize(X) returns zero.  If X points to something that is not

  3833. ** the beginning of memory allocation, or if it points to a formerly

  3834. ** valid memory allocation that has now been freed, then the behavior

  3835. ** of sqlite3_msize(X) is undefined and possibly harmful.

  3836. **

  3837. ** ^The memory returned by sqlite3_malloc(), sqlite3_realloc(),

  3838. ** sqlite3_malloc64(), and sqlite3_realloc64()

  3839. ** is always aligned to at least an 8 byte boundary, or to a

  3840. ** 4 byte boundary if the [SQLITE_4_BYTE_ALIGNED_MALLOC] compile-time

  3841. ** option is used.

  3842. **

  3843. ** In SQLite version 3.5.0 and 3.5.1, it was possible to define

  3844. ** the SQLITE_OMIT_MEMORY_ALLOCATION which would cause the built-in

  3845. ** implementation of these routines to be omitted.  That capability

  3846. ** is no longer provided.  Only built-in memory allocators can be used.

  3847. **

  3848. ** Prior to SQLite version 3.7.10, the Windows OS interface layer called

  3849. ** the system malloc() and free() directly when converting

  3850. ** filenames between the UTF-8 encoding used by SQLite

  3851. ** and whatever filename encoding is used by the particular Windows

  3852. ** installation.  Memory allocation errors were detected, but

  3853. ** they were reported back as [SQLITE_CANTOPEN] or

  3854. ** [SQLITE_IOERR] rather than [SQLITE_NOMEM].

  3855. **

  3856. ** The pointer arguments to [sqlite3_free()] and [sqlite3_realloc()]

  3857. ** must be either NULL or else pointers obtained from a prior

  3858. ** invocation of [sqlite3_malloc()] or [sqlite3_realloc()] that have

  3859. ** not yet been released.

  3860. **

  3861. ** The application must not read or write any part of

  3862. ** a block of memory after it has been released using

  3863. ** [sqlite3_free()] or [sqlite3_realloc()].

  3864. */

  3865. SQLITE_API void *sqlite3_malloc(int);

  3866. SQLITE_API void *sqlite3_malloc64(sqlite3_uint64);

  3867. SQLITE_API void *sqlite3_realloc(void*, int);

  3868. SQLITE_API void *sqlite3_realloc64(void*, sqlite3_uint64);

  3869. SQLITE_API void sqlite3_free(void*);

  3870. SQLITE_API sqlite3_uint64 sqlite3_msize(void*);

  3871. 

  3872. /*

  3873. ** CAPI3REF: Memory Allocator Statistics

  3874. **

  3875. ** SQLite provides these two interfaces for reporting on the status

  3876. ** of the [sqlite3_malloc()], [sqlite3_free()], and [sqlite3_realloc()]

  3877. ** routines, which form the built-in memory allocation subsystem.

  3878. **

  3879. ** ^The [sqlite3_memory_used()] routine returns the number of bytes

  3880. ** of memory currently outstanding (malloced but not freed).

  3881. ** ^The [sqlite3_memory_highwater()] routine returns the maximum

  3882. ** value of [sqlite3_memory_used()] since the high-water mark

  3883. ** was last reset.  ^The values returned by [sqlite3_memory_used()] and

  3884. ** [sqlite3_memory_highwater()] include any overhead

  3885. ** added by SQLite in its implementation of [sqlite3_malloc()],

  3886. ** but not overhead added by the any underlying system library

  3887. ** routines that [sqlite3_malloc()] may call.

  3888. **

  3889. ** ^The memory high-water mark is reset to the current value of

  3890. ** [sqlite3_memory_used()] if and only if the parameter to

  3891. ** [sqlite3_memory_highwater()] is true.  ^The value returned

  3892. ** by [sqlite3_memory_highwater(1)] is the high-water mark

  3893. ** prior to the reset.

  3894. */

  3895. SQLITE_API sqlite3_int64 sqlite3_memory_used(void);

  3896. SQLITE_API sqlite3_int64 sqlite3_memory_highwater(int resetFlag);

  3897. 

  3898. /*

  3899. ** CAPI3REF: Pseudo-Random Number Generator

  3900. **

  3901. ** SQLite contains a high-quality pseudo-random number generator (PRNG) used to

  3902. ** select random [ROWID | ROWIDs] when inserting new records into a table that

  3903. ** already uses the largest possible [ROWID].  The PRNG is also used for

  3904. ** the build-in random() and randomblob() SQL functions.  This interface allows

  3905. ** applications to access the same PRNG for other purposes.

  3906. **

  3907. ** ^A call to this routine stores N bytes of randomness into buffer P.

  3908. ** ^The P parameter can be a NULL pointer.

  3909. **

  3910. ** ^If this routine has not been previously called or if the previous

  3911. ** call had N less than one or a NULL pointer for P, then the PRNG is

  3912. ** seeded using randomness obtained from the xRandomness method of

  3913. ** the default [sqlite3_vfs] object.

  3914. ** ^If the previous call to this routine had an N of 1 or more and a

  3915. ** non-NULL P then the pseudo-randomness is generated

  3916. ** internally and without recourse to the [sqlite3_vfs] xRandomness

  3917. ** method.

  3918. */

  3919. SQLITE_API void sqlite3_randomness(int N, void *P);

  3920. 

  3921. /*

  3922. ** CAPI3REF: Compile-Time Authorization Callbacks

  3923. ** METHOD: sqlite3

  3924. ** KEYWORDS: {authorizer callback}

  3925. **

  3926. ** ^This routine registers an authorizer callback with a particular

  3927. ** [database connection], supplied in the first argument.

  3928. ** ^The authorizer callback is invoked as SQL statements are being compiled

  3929. ** by [sqlite3_prepare()] or its variants [sqlite3_prepare_v2()],

  3930. ** [sqlite3_prepare_v3()], [sqlite3_prepare16()], [sqlite3_prepare16_v2()],

  3931. ** and [sqlite3_prepare16_v3()].  ^At various

  3932. ** points during the compilation process, as logic is being created

  3933. ** to perform various actions, the authorizer callback is invoked to

  3934. ** see if those actions are allowed.  ^The authorizer callback should

  3935. ** return [SQLITE_OK] to allow the action, [SQLITE_IGNORE] to disallow the

  3936. ** specific action but allow the SQL statement to continue to be

  3937. ** compiled, or [SQLITE_DENY] to cause the entire SQL statement to be

  3938. ** rejected with an error.  ^If the authorizer callback returns

  3939. ** any value other than [SQLITE_IGNORE], [SQLITE_OK], or [SQLITE_DENY]

  3940. ** then the [sqlite3_prepare_v2()] or equivalent call that triggered

  3941. ** the authorizer will fail with an error message.

  3942. **

  3943. ** When the callback returns [SQLITE_OK], that means the operation

  3944. ** requested is ok.  ^When the callback returns [SQLITE_DENY], the

  3945. ** [sqlite3_prepare_v2()] or equivalent call that triggered the

  3946. ** authorizer will fail with an error message explaining that

  3947. ** access is denied. 

  3948. **

  3949. ** ^The first parameter to the authorizer callback is a copy of the third

  3950. ** parameter to the sqlite3_set_authorizer() interface. ^The second parameter

  3951. ** to the callback is an integer [SQLITE_COPY | action code] that specifies

  3952. ** the particular action to be authorized. ^The third through sixth parameters

  3953. ** to the callback are either NULL pointers or zero-terminated strings

  3954. ** that contain additional details about the action to be authorized.

  3955. ** Applications must always be prepared to encounter a NULL pointer in any

  3956. ** of the third through the sixth parameters of the authorization callback.

  3957. **

  3958. ** ^If the action code is [SQLITE_READ]

  3959. ** and the callback returns [SQLITE_IGNORE] then the

  3960. ** [prepared statement] statement is constructed to substitute

  3961. ** a NULL value in place of the table column that would have

  3962. ** been read if [SQLITE_OK] had been returned.  The [SQLITE_IGNORE]

  3963. ** return can be used to deny an untrusted user access to individual

  3964. ** columns of a table.

  3965. ** ^When a table is referenced by a [SELECT] but no column values are

  3966. ** extracted from that table (for example in a query like

  3967. ** "SELECT count(*) FROM tab") then the [SQLITE_READ] authorizer callback

  3968. ** is invoked once for that table with a column name that is an empty string.

  3969. ** ^If the action code is [SQLITE_DELETE] and the callback returns

  3970. ** [SQLITE_IGNORE] then the [DELETE] operation proceeds but the

  3971. ** [truncate optimization] is disabled and all rows are deleted individually.

  3972. **

  3973. ** An authorizer is used when [sqlite3_prepare | preparing]

  3974. ** SQL statements from an untrusted source, to ensure that the SQL statements

  3975. ** do not try to access data they are not allowed to see, or that they do not

  3976. ** try to execute malicious statements that damage the database.  For

  3977. ** example, an application may allow a user to enter arbitrary

  3978. ** SQL queries for evaluation by a database.  But the application does

  3979. ** not want the user to be able to make arbitrary changes to the

  3980. ** database.  An authorizer could then be put in place while the

  3981. ** user-entered SQL is being [sqlite3_prepare | prepared] that

  3982. ** disallows everything except [SELECT] statements.

  3983. **

  3984. ** Applications that need to process SQL from untrusted sources

  3985. ** might also consider lowering resource limits using [sqlite3_limit()]

  3986. ** and limiting database size using the [max_page_count] [PRAGMA]

  3987. ** in addition to using an authorizer.

  3988. **

  3989. ** ^(Only a single authorizer can be in place on a database connection

  3990. ** at a time.  Each call to sqlite3_set_authorizer overrides the

  3991. ** previous call.)^  ^Disable the authorizer by installing a NULL callback.

  3992. ** The authorizer is disabled by default.

  3993. **

  3994. ** The authorizer callback must not do anything that will modify

  3995. ** the database connection that invoked the authorizer callback.

  3996. ** Note that [sqlite3_prepare_v2()] and [sqlite3_step()] both modify their

  3997. ** database connections for the meaning of "modify" in this paragraph.

  3998. **

  3999. ** ^When [sqlite3_prepare_v2()] is used to prepare a statement, the

  4000. ** statement might be re-prepared during [sqlite3_step()] due to a 

  4001. ** schema change.  Hence, the application should ensure that the

  4002. ** correct authorizer callback remains in place during the [sqlite3_step()].

  4003. **

  4004. ** ^Note that the authorizer callback is invoked only during

  4005. ** [sqlite3_prepare()] or its variants.  Authorization is not

  4006. ** performed during statement evaluation in [sqlite3_step()], unless

  4007. ** as stated in the previous paragraph, sqlite3_step() invokes

  4008. ** sqlite3_prepare_v2() to reprepare a statement after a schema change.

  4009. */

  4010. SQLITE_API int sqlite3_set_authorizer(

  4011.   sqlite3*,

  4012.   int (*xAuth)(void*,int,const char*,const char*,const char*,const char*),

  4013.   void *pUserData

  4014. );

  4015. 

  4016. /*

  4017. ** CAPI3REF: Authorizer Return Codes

  4018. **

  4019. ** The [sqlite3_set_authorizer | authorizer callback function] must

  4020. ** return either [SQLITE_OK] or one of these two constants in order

  4021. ** to signal SQLite whether or not the action is permitted.  See the

  4022. ** [sqlite3_set_authorizer | authorizer documentation] for additional

  4023. ** information.

  4024. **

  4025. ** Note that SQLITE_IGNORE is also used as a [conflict resolution mode]

  4026. ** returned from the [sqlite3_vtab_on_conflict()] interface.

  4027. */

  4028. #define SQLITE_DENY   1   /* Abort the SQL statement with an error */

  4029. #define SQLITE_IGNORE 2   /* Don't allow access, but don't generate an error */

  4030. 

  4031. /*

  4032. ** CAPI3REF: Authorizer Action Codes

  4033. **

  4034. ** The [sqlite3_set_authorizer()] interface registers a callback function

  4035. ** that is invoked to authorize certain SQL statement actions.  The

  4036. ** second parameter to the callback is an integer code that specifies

  4037. ** what action is being authorized.  These are the integer action codes that

  4038. ** the authorizer callback may be passed.

  4039. **

  4040. ** These action code values signify what kind of operation is to be

  4041. ** authorized.  The 3rd and 4th parameters to the authorization

  4042. ** callback function will be parameters or NULL depending on which of these

  4043. ** codes is used as the second parameter.  ^(The 5th parameter to the

  4044. ** authorizer callback is the name of the database ("main", "temp",

  4045. ** etc.) if applicable.)^  ^The 6th parameter to the authorizer callback

  4046. ** is the name of the inner-most trigger or view that is responsible for

  4047. ** the access attempt or NULL if this access attempt is directly from

  4048. ** top-level SQL code.

  4049. */

  4050. /******************************************* 3rd ************ 4th ***********/

  4051. #define SQLITE_CREATE_INDEX          1   /* Index Name      Table Name      */

  4052. #define SQLITE_CREATE_TABLE          2   /* Table Name      NULL            */

  4053. #define SQLITE_CREATE_TEMP_INDEX     3   /* Index Name      Table Name      */

  4054. #define SQLITE_CREATE_TEMP_TABLE     4   /* Table Name      NULL            */

  4055. #define SQLITE_CREATE_TEMP_TRIGGER   5   /* Trigger Name    Table Name      */

  4056. #define SQLITE_CREATE_TEMP_VIEW      6   /* View Name       NULL            */

  4057. #define SQLITE_CREATE_TRIGGER        7   /* Trigger Name    Table Name      */

  4058. #define SQLITE_CREATE_VIEW           8   /* View Name       NULL            */

  4059. #define SQLITE_DELETE                9   /* Table Name      NULL            */

  4060. #define SQLITE_DROP_INDEX           10   /* Index Name      Table Name      */

  4061. #define SQLITE_DROP_TABLE           11   /* Table Name      NULL            */

  4062. #define SQLITE_DROP_TEMP_INDEX      12   /* Index Name      Table Name      */

  4063. #define SQLITE_DROP_TEMP_TABLE      13   /* Table Name      NULL            */

  4064. #define SQLITE_DROP_TEMP_TRIGGER    14   /* Trigger Name    Table Name      */

  4065. #define SQLITE_DROP_TEMP_VIEW       15   /* View Name       NULL            */

  4066. #define SQLITE_DROP_TRIGGER         16   /* Trigger Name    Table Name      */

  4067. #define SQLITE_DROP_VIEW            17   /* View Name       NULL            */

  4068. #define SQLITE_INSERT               18   /* Table Name      NULL            */

  4069. #define SQLITE_PRAGMA               19   /* Pragma Name     1st arg or NULL */

  4070. #define SQLITE_READ                 20   /* Table Name      Column Name     */

  4071. #define SQLITE_SELECT               21   /* NULL            NULL            */

  4072. #define SQLITE_TRANSACTION          22   /* Operation       NULL            */

  4073. #define SQLITE_UPDATE               23   /* Table Name      Column Name     */

  4074. #define SQLITE_ATTACH               24   /* Filename        NULL            */

  4075. #define SQLITE_DETACH               25   /* Database Name   NULL            */

  4076. #define SQLITE_ALTER_TABLE          26   /* Database Name   Table Name      */

  4077. #define SQLITE_REINDEX              27   /* Index Name      NULL            */

  4078. #define SQLITE_ANALYZE              28   /* Table Name      NULL            */

  4079. #define SQLITE_CREATE_VTABLE        29   /* Table Name      Module Name     */

  4080. #define SQLITE_DROP_VTABLE          30   /* Table Name      Module Name     */

  4081. #define SQLITE_FUNCTION             31   /* NULL            Function Name   */

  4082. #define SQLITE_SAVEPOINT            32   /* Operation       Savepoint Name  */

  4083. #define SQLITE_COPY                  0   /* No longer used */

  4084. #define SQLITE_RECURSIVE            33   /* NULL            NULL            */

  4085. 

  4086. /*

  4087. ** CAPI3REF: Tracing And Profiling Functions

  4088. ** METHOD: sqlite3

  4089. **

  4090. ** These routines are deprecated. Use the [sqlite3_trace_v2()] interface

  4091. ** instead of the routines described here.

  4092. **

  4093. ** These routines register callback functions that can be used for

  4094. ** tracing and profiling the execution of SQL statements.

  4095. **

  4096. ** ^The callback function registered by sqlite3_trace() is invoked at

  4097. ** various times when an SQL statement is being run by [sqlite3_step()].

  4098. ** ^The sqlite3_trace() callback is invoked with a UTF-8 rendering of the

  4099. ** SQL statement text as the statement first begins executing.

  4100. ** ^(Additional sqlite3_trace() callbacks might occur

  4101. ** as each triggered subprogram is entered.  The callbacks for triggers

  4102. ** contain a UTF-8 SQL comment that identifies the trigger.)^

  4103. **

  4104. ** The [SQLITE_TRACE_SIZE_LIMIT] compile-time option can be used to limit

  4105. ** the length of [bound parameter] expansion in the output of sqlite3_trace().

  4106. **

  4107. ** ^The callback function registered by sqlite3_profile() is invoked

  4108. ** as each SQL statement finishes.  ^The profile callback contains

  4109. ** the original statement text and an estimate of wall-clock time

  4110. ** of how long that statement took to run.  ^The profile callback

  4111. ** time is in units of nanoseconds, however the current implementation

  4112. ** is only capable of millisecond resolution so the six least significant

  4113. ** digits in the time are meaningless.  Future versions of SQLite

  4114. ** might provide greater resolution on the profiler callback.  Invoking

  4115. ** either [sqlite3_trace()] or [sqlite3_trace_v2()] will cancel the

  4116. ** profile callback.

  4117. */

  4118. SQLITE_API SQLITE_DEPRECATED void *sqlite3_trace(sqlite3*,

  4119.    void(*xTrace)(void*,const char*), void*);

  4120. SQLITE_API SQLITE_DEPRECATED void *sqlite3_profile(sqlite3*,

  4121.    void(*xProfile)(void*,const char*,sqlite3_uint64), void*);

  4122. 

  4123. /*

  4124. ** CAPI3REF: SQL Trace Event Codes

  4125. ** KEYWORDS: SQLITE_TRACE

  4126. **

  4127. ** These constants identify classes of events that can be monitored

  4128. ** using the [sqlite3_trace_v2()] tracing logic.  The M argument

  4129. ** to [sqlite3_trace_v2(D,M,X,P)] is an OR-ed combination of one or more of

  4130. ** the following constants.  ^The first argument to the trace callback

  4131. ** is one of the following constants.

  4132. **

  4133. ** New tracing constants may be added in future releases.

  4134. **

  4135. ** ^A trace callback has four arguments: xCallback(T,C,P,X).

  4136. ** ^The T argument is one of the integer type codes above.

  4137. ** ^The C argument is a copy of the context pointer passed in as the

  4138. ** fourth argument to [sqlite3_trace_v2()].

  4139. ** The P and X arguments are pointers whose meanings depend on T.

  4140. **

  4141. ** <dl>

  4142. ** [[SQLITE_TRACE_STMT]] <dt>SQLITE_TRACE_STMT</dt>

  4143. ** <dd>^An SQLITE_TRACE_STMT callback is invoked when a prepared statement

  4144. ** first begins running and possibly at other times during the

  4145. ** execution of the prepared statement, such as at the start of each

  4146. ** trigger subprogram. ^The P argument is a pointer to the

  4147. ** [prepared statement]. ^The X argument is a pointer to a string which

  4148. ** is the unexpanded SQL text of the prepared statement or an SQL comment 

  4149. ** that indicates the invocation of a trigger.  ^The callback can compute

  4150. ** the same text that would have been returned by the legacy [sqlite3_trace()]

  4151. ** interface by using the X argument when X begins with "--" and invoking

  4152. ** [sqlite3_expanded_sql(P)] otherwise.

  4153. **

  4154. ** [[SQLITE_TRACE_PROFILE]] <dt>SQLITE_TRACE_PROFILE</dt>

  4155. ** <dd>^An SQLITE_TRACE_PROFILE callback provides approximately the same

  4156. ** information as is provided by the [sqlite3_profile()] callback.

  4157. ** ^The P argument is a pointer to the [prepared statement] and the

  4158. ** X argument points to a 64-bit integer which is the estimated of

  4159. ** the number of nanosecond that the prepared statement took to run.

  4160. ** ^The SQLITE_TRACE_PROFILE callback is invoked when the statement finishes.

  4161. **

  4162. ** [[SQLITE_TRACE_ROW]] <dt>SQLITE_TRACE_ROW</dt>

  4163. ** <dd>^An SQLITE_TRACE_ROW callback is invoked whenever a prepared

  4164. ** statement generates a single row of result.  

  4165. ** ^The P argument is a pointer to the [prepared statement] and the

  4166. ** X argument is unused.

  4167. **

  4168. ** [[SQLITE_TRACE_CLOSE]] <dt>SQLITE_TRACE_CLOSE</dt>

  4169. ** <dd>^An SQLITE_TRACE_CLOSE callback is invoked when a database

  4170. ** connection closes.

  4171. ** ^The P argument is a pointer to the [database connection] object

  4172. ** and the X argument is unused.

  4173. ** </dl>

  4174. */

  4175. #define SQLITE_TRACE_STMT       0x01

  4176. #define SQLITE_TRACE_PROFILE    0x02

  4177. #define SQLITE_TRACE_ROW        0x04

  4178. #define SQLITE_TRACE_CLOSE      0x08

  4179. 

  4180. /*

  4181. ** CAPI3REF: SQL Trace Hook

  4182. ** METHOD: sqlite3

  4183. **

  4184. ** ^The sqlite3_trace_v2(D,M,X,P) interface registers a trace callback

  4185. ** function X against [database connection] D, using property mask M

  4186. ** and context pointer P.  ^If the X callback is

  4187. ** NULL or if the M mask is zero, then tracing is disabled.  The

  4188. ** M argument should be the bitwise OR-ed combination of

  4189. ** zero or more [SQLITE_TRACE] constants.

  4190. **

  4191. ** ^Each call to either sqlite3_trace() or sqlite3_trace_v2() overrides 

  4192. ** (cancels) any prior calls to sqlite3_trace() or sqlite3_trace_v2().

  4193. **

  4194. ** ^The X callback is invoked whenever any of the events identified by 

  4195. ** mask M occur.  ^The integer return value from the callback is currently

  4196. ** ignored, though this may change in future releases.  Callback

  4197. ** implementations should return zero to ensure future compatibility.

  4198. **

  4199. ** ^A trace callback is invoked with four arguments: callback(T,C,P,X).

  4200. ** ^The T argument is one of the [SQLITE_TRACE]

  4201. ** constants to indicate why the callback was invoked.

  4202. ** ^The C argument is a copy of the context pointer.

  4203. ** The P and X arguments are pointers whose meanings depend on T.

  4204. **

  4205. ** The sqlite3_trace_v2() interface is intended to replace the legacy

  4206. ** interfaces [sqlite3_trace()] and [sqlite3_profile()], both of which

  4207. ** are deprecated.

  4208. */

  4209. SQLITE_API int sqlite3_trace_v2(

  4210.   sqlite3*,

  4211.   unsigned uMask,

  4212.   int(*xCallback)(unsigned,void*,void*,void*),

  4213.   void *pCtx

  4214. );

  4215. 

  4216. /*

  4217. ** CAPI3REF: Query Progress Callbacks

  4218. ** METHOD: sqlite3

  4219. **

  4220. ** ^The sqlite3_progress_handler(D,N,X,P) interface causes the callback

  4221. ** function X to be invoked periodically during long running calls to

  4222. ** [sqlite3_exec()], [sqlite3_step()] and [sqlite3_get_table()] for

  4223. ** database connection D.  An example use for this

  4224. ** interface is to keep a GUI updated during a large query.

  4225. **

  4226. ** ^The parameter P is passed through as the only parameter to the 

  4227. ** callback function X.  ^The parameter N is the approximate number of 

  4228. ** [virtual machine instructions] that are evaluated between successive

  4229. ** invocations of the callback X.  ^If N is less than one then the progress

  4230. ** handler is disabled.

  4231. **

  4232. ** ^Only a single progress handler may be defined at one time per

  4233. ** [database connection]; setting a new progress handler cancels the

  4234. ** old one.  ^Setting parameter X to NULL disables the progress handler.

  4235. ** ^The progress handler is also disabled by setting N to a value less

  4236. ** than 1.

  4237. **

  4238. ** ^If the progress callback returns non-zero, the operation is

  4239. ** interrupted.  This feature can be used to implement a

  4240. ** "Cancel" button on a GUI progress dialog box.

  4241. **

  4242. ** The progress handler callback must not do anything that will modify

  4243. ** the database connection that invoked the progress handler.

  4244. ** Note that [sqlite3_prepare_v2()] and [sqlite3_step()] both modify their

  4245. ** database connections for the meaning of "modify" in this paragraph.

  4246. **

  4247. */

  4248. SQLITE_API void sqlite3_progress_handler(sqlite3*, int, int(*)(void*), void*);

  4249. 

  4250. /*

  4251. ** CAPI3REF: Opening A New Database Connection

  4252. ** CONSTRUCTOR: sqlite3

  4253. **

  4254. ** ^These routines open an SQLite database file as specified by the 

  4255. ** filename argument. ^The filename argument is interpreted as UTF-8 for

  4256. ** sqlite3_open() and sqlite3_open_v2() and as UTF-16 in the native byte

  4257. ** order for sqlite3_open16(). ^(A [database connection] handle is usually

  4258. ** returned in *ppDb, even if an error occurs.  The only exception is that

  4259. ** if SQLite is unable to allocate memory to hold the [sqlite3] object,

  4260. ** a NULL will be written into *ppDb instead of a pointer to the [sqlite3]

  4261. ** object.)^ ^(If the database is opened (and/or created) successfully, then

  4262. ** [SQLITE_OK] is returned.  Otherwise an [error code] is returned.)^ ^The

  4263. ** [sqlite3_errmsg()] or [sqlite3_errmsg16()] routines can be used to obtain

  4264. ** an English language description of the error following a failure of any

  4265. ** of the sqlite3_open() routines.

  4266. **

  4267. ** ^The default encoding will be UTF-8 for databases created using

  4268. ** sqlite3_open() or sqlite3_open_v2().  ^The default encoding for databases

  4269. ** created using sqlite3_open16() will be UTF-16 in the native byte order.

  4270. **

  4271. ** Whether or not an error occurs when it is opened, resources

  4272. ** associated with the [database connection] handle should be released by

  4273. ** passing it to [sqlite3_close()] when it is no longer required.

  4274. **

  4275. ** The sqlite3_open_v2() interface works like sqlite3_open()

  4276. ** except that it accepts two additional parameters for additional control

  4277. ** over the new database connection.  ^(The flags parameter to

  4278. ** sqlite3_open_v2() can take one of

  4279. ** the following three values, optionally combined with the 

  4280. ** [SQLITE_OPEN_NOMUTEX], [SQLITE_OPEN_FULLMUTEX], [SQLITE_OPEN_SHAREDCACHE],

  4281. ** [SQLITE_OPEN_PRIVATECACHE], and/or [SQLITE_OPEN_URI] flags:)^

  4282. **

  4283. ** <dl>

  4284. ** ^(<dt>[SQLITE_OPEN_READONLY]</dt>

  4285. ** <dd>The database is opened in read-only mode.  If the database does not

  4286. ** already exist, an error is returned.</dd>)^

  4287. **

  4288. ** ^(<dt>[SQLITE_OPEN_READWRITE]</dt>

  4289. ** <dd>The database is opened for reading and writing if possible, or reading

  4290. ** only if the file is write protected by the operating system.  In either

  4291. ** case the database must already exist, otherwise an error is returned.</dd>)^

  4292. **

  4293. ** ^(<dt>[SQLITE_OPEN_READWRITE] | [SQLITE_OPEN_CREATE]</dt>

  4294. ** <dd>The database is opened for reading and writing, and is created if

  4295. ** it does not already exist. This is the behavior that is always used for

  4296. ** sqlite3_open() and sqlite3_open16().</dd>)^

  4297. ** </dl>

  4298. **

  4299. ** If the 3rd parameter to sqlite3_open_v2() is not one of the

  4300. ** combinations shown above optionally combined with other

  4301. ** [SQLITE_OPEN_READONLY | SQLITE_OPEN_* bits]

  4302. ** then the behavior is undefined.

  4303. **

  4304. ** ^If the [SQLITE_OPEN_NOMUTEX] flag is set, then the database connection

  4305. ** opens in the multi-thread [threading mode] as long as the single-thread

  4306. ** mode has not been set at compile-time or start-time.  ^If the

  4307. ** [SQLITE_OPEN_FULLMUTEX] flag is set then the database connection opens

  4308. ** in the serialized [threading mode] unless single-thread was

  4309. ** previously selected at compile-time or start-time.

  4310. ** ^The [SQLITE_OPEN_SHAREDCACHE] flag causes the database connection to be

  4311. ** eligible to use [shared cache mode], regardless of whether or not shared

  4312. ** cache is enabled using [sqlite3_enable_shared_cache()].  ^The

  4313. ** [SQLITE_OPEN_PRIVATECACHE] flag causes the database connection to not

  4314. ** participate in [shared cache mode] even if it is enabled.

  4315. **

  4316. ** ^The fourth parameter to sqlite3_open_v2() is the name of the

  4317. ** [sqlite3_vfs] object that defines the operating system interface that

  4318. ** the new database connection should use.  ^If the fourth parameter is

  4319. ** a NULL pointer then the default [sqlite3_vfs] object is used.

  4320. **

  4321. ** ^If the filename is ":memory:", then a private, temporary in-memory database

  4322. ** is created for the connection.  ^This in-memory database will vanish when

  4323. ** the database connection is closed.  Future versions of SQLite might

  4324. ** make use of additional special filenames that begin with the ":" character.

  4325. ** It is recommended that when a database filename actually does begin with

  4326. ** a ":" character you should prefix the filename with a pathname such as

  4327. ** "./" to avoid ambiguity.

  4328. **

  4329. ** ^If the filename is an empty string, then a private, temporary

  4330. ** on-disk database will be created.  ^This private database will be

  4331. ** automatically deleted as soon as the database connection is closed.

  4332. **

  4333. ** [[URI filenames in sqlite3_open()]] <h3>URI Filenames</h3>

  4334. **

  4335. ** ^If [URI filename] interpretation is enabled, and the filename argument

  4336. ** begins with "file:", then the filename is interpreted as a URI. ^URI

  4337. ** filename interpretation is enabled if the [SQLITE_OPEN_URI] flag is

  4338. ** set in the third argument to sqlite3_open_v2(), or if it has

  4339. ** been enabled globally using the [SQLITE_CONFIG_URI] option with the

  4340. ** [sqlite3_config()] method or by the [SQLITE_USE_URI] compile-time option.

  4341. ** URI filename interpretation is turned off

  4342. ** by default, but future releases of SQLite might enable URI filename

  4343. ** interpretation by default.  See "[URI filenames]" for additional

  4344. ** information.

  4345. **

  4346. ** URI filenames are parsed according to RFC 3986. ^If the URI contains an

  4347. ** authority, then it must be either an empty string or the string 

  4348. ** "localhost". ^If the authority is not an empty string or "localhost", an 

  4349. ** error is returned to the caller. ^The fragment component of a URI, if 

  4350. ** present, is ignored.

  4351. **

  4352. ** ^SQLite uses the path component of the URI as the name of the disk file

  4353. ** which contains the database. ^If the path begins with a '/' character, 

  4354. ** then it is interpreted as an absolute path. ^If the path does not begin 

  4355. ** with a '/' (meaning that the authority section is omitted from the URI)

  4356. ** then the path is interpreted as a relative path. 

  4357. ** ^(On windows, the first component of an absolute path 

  4358. ** is a drive specification (e.g. "C:").)^

  4359. **

  4360. ** [[core URI query parameters]]

  4361. ** The query component of a URI may contain parameters that are interpreted

  4362. ** either by SQLite itself, or by a [VFS | custom VFS implementation].

  4363. ** SQLite and its built-in [VFSes] interpret the

  4364. ** following query parameters:

  4365. **

  4366. ** <ul>

  4367. **   <li> <b>vfs</b>: ^The "vfs" parameter may be used to specify the name of

  4368. **     a VFS object that provides the operating system interface that should

  4369. **     be used to access the database file on disk. ^If this option is set to

  4370. **     an empty string the default VFS object is used. ^Specifying an unknown

  4371. **     VFS is an error. ^If sqlite3_open_v2() is used and the vfs option is

  4372. **     present, then the VFS specified by the option takes precedence over

  4373. **     the value passed as the fourth parameter to sqlite3_open_v2().

  4374. **

  4375. **   <li> <b>mode</b>: ^(The mode parameter may be set to either "ro", "rw",

  4376. **     "rwc", or "memory". Attempting to set it to any other value is

  4377. **     an error)^. 

  4378. **     ^If "ro" is specified, then the database is opened for read-only 

  4379. **     access, just as if the [SQLITE_OPEN_READONLY] flag had been set in the 

  4380. **     third argument to sqlite3_open_v2(). ^If the mode option is set to 

  4381. **     "rw", then the database is opened for read-write (but not create) 

  4382. **     access, as if SQLITE_OPEN_READWRITE (but not SQLITE_OPEN_CREATE) had 

  4383. **     been set. ^Value "rwc" is equivalent to setting both 

  4384. **     SQLITE_OPEN_READWRITE and SQLITE_OPEN_CREATE.  ^If the mode option is

  4385. **     set to "memory" then a pure [in-memory database] that never reads

  4386. **     or writes from disk is used. ^It is an error to specify a value for

  4387. **     the mode parameter that is less restrictive than that specified by

  4388. **     the flags passed in the third parameter to sqlite3_open_v2().

  4389. **

  4390. **   <li> <b>cache</b>: ^The cache parameter may be set to either "shared" or

  4391. **     "private". ^Setting it to "shared" is equivalent to setting the

  4392. **     SQLITE_OPEN_SHAREDCACHE bit in the flags argument passed to

  4393. **     sqlite3_open_v2(). ^Setting the cache parameter to "private" is 

  4394. **     equivalent to setting the SQLITE_OPEN_PRIVATECACHE bit.

  4395. **     ^If sqlite3_open_v2() is used and the "cache" parameter is present in

  4396. **     a URI filename, its value overrides any behavior requested by setting

  4397. **     SQLITE_OPEN_PRIVATECACHE or SQLITE_OPEN_SHAREDCACHE flag.

  4398. **

  4399. **  <li> <b>psow</b>: ^The psow parameter indicates whether or not the

  4400. **     [powersafe overwrite] property does or does not apply to the

  4401. **     storage media on which the database file resides.

  4402. **

  4403. **  <li> <b>nolock</b>: ^The nolock parameter is a boolean query parameter

  4404. **     which if set disables file locking in rollback journal modes.  This

  4405. **     is useful for accessing a database on a filesystem that does not

  4406. **     support locking.  Caution:  Database corruption might result if two

  4407. **     or more processes write to the same database and any one of those

  4408. **     processes uses nolock=1.

  4409. **

  4410. **  <li> <b>immutable</b>: ^The immutable parameter is a boolean query

  4411. **     parameter that indicates that the database file is stored on

  4412. **     read-only media.  ^When immutable is set, SQLite assumes that the

  4413. **     database file cannot be changed, even by a process with higher

  4414. **     privilege, and so the database is opened read-only and all locking

  4415. **     and change detection is disabled.  Caution: Setting the immutable

  4416. **     property on a database file that does in fact change can result

  4417. **     in incorrect query results and/or [SQLITE_CORRUPT] errors.

  4418. **     See also: [SQLITE_IOCAP_IMMUTABLE].

  4419. **       

  4420. ** </ul>

  4421. **

  4422. ** ^Specifying an unknown parameter in the query component of a URI is not an

  4423. ** error.  Future versions of SQLite might understand additional query

  4424. ** parameters.  See "[query parameters with special meaning to SQLite]" for

  4425. ** additional information.

  4426. **

  4427. ** [[URI filename examples]] <h3>URI filename examples</h3>

  4428. **

  4429. ** <table border="1" align=center cellpadding=5>

  4430. ** <tr><th> URI filenames <th> Results

  4431. ** <tr><td> file:data.db <td> 

  4432. **          Open the file "data.db" in the current directory.

  4433. ** <tr><td> file:/home/fred/data.db<br>

  4434. **          file:///home/fred/data.db <br> 

  4435. **          file://localhost/home/fred/data.db <br> <td> 

  4436. **          Open the database file "/home/fred/data.db".

  4437. ** <tr><td> file://darkstar/home/fred/data.db <td> 

  4438. **          An error. "darkstar" is not a recognized authority.

  4439. ** <tr><td style="white-space:nowrap"> 

  4440. **          file:///C:/Documents%20and%20Settings/fred/Desktop/data.db

  4441. **     <td> Windows only: Open the file "data.db" on fred's desktop on drive

  4442. **          C:. Note that the %20 escaping in this example is not strictly 

  4443. **          necessary - space characters can be used literally

  4444. **          in URI filenames.

  4445. ** <tr><td> file:data.db?mode=ro&cache=private <td> 

  4446. **          Open file "data.db" in the current directory for read-only access.

  4447. **          Regardless of whether or not shared-cache mode is enabled by

  4448. **          default, use a private cache.

  4449. ** <tr><td> file:/home/fred/data.db?vfs=unix-dotfile <td>

  4450. **          Open file "/home/fred/data.db". Use the special VFS "unix-dotfile"

  4451. **          that uses dot-files in place of posix advisory locking.

  4452. ** <tr><td> file:data.db?mode=readonly <td> 

  4453. **          An error. "readonly" is not a valid option for the "mode" parameter.

  4454. ** </table>

  4455. **

  4456. ** ^URI hexadecimal escape sequences (%HH) are supported within the path and

  4457. ** query components of a URI. A hexadecimal escape sequence consists of a

  4458. ** percent sign - "%" - followed by exactly two hexadecimal digits 

  4459. ** specifying an octet value. ^Before the path or query components of a

  4460. ** URI filename are interpreted, they are encoded using UTF-8 and all 

  4461. ** hexadecimal escape sequences replaced by a single byte containing the

  4462. ** corresponding octet. If this process generates an invalid UTF-8 encoding,

  4463. ** the results are undefined.

  4464. **

  4465. ** <b>Note to Windows users:</b>  The encoding used for the filename argument

  4466. ** of sqlite3_open() and sqlite3_open_v2() must be UTF-8, not whatever

  4467. ** codepage is currently defined.  Filenames containing international

  4468. ** characters must be converted to UTF-8 prior to passing them into

  4469. ** sqlite3_open() or sqlite3_open_v2().

  4470. **

  4471. ** <b>Note to Windows Runtime users:</b>  The temporary directory must be set

  4472. ** prior to calling sqlite3_open() or sqlite3_open_v2().  Otherwise, various

  4473. ** features that require the use of temporary files may fail.

  4474. **

  4475. ** See also: [sqlite3_temp_directory]

  4476. */

  4477. SQLITE_API int sqlite3_open(

  4478.   const char *filename,   /* Database filename (UTF-8) */

  4479.   sqlite3 **ppDb          /* OUT: SQLite db handle */

  4480. );

  4481. SQLITE_API int sqlite3_open16(

  4482.   const void *filename,   /* Database filename (UTF-16) */

  4483.   sqlite3 **ppDb          /* OUT: SQLite db handle */

  4484. );

  4485. SQLITE_API int sqlite3_open_v2(

  4486.   const char *filename,   /* Database filename (UTF-8) */

  4487.   sqlite3 **ppDb,         /* OUT: SQLite db handle */

  4488.   int flags,              /* Flags */

  4489.   const char *zVfs        /* Name of VFS module to use */

  4490. );

  4491. 

  4492. /*

  4493. ** CAPI3REF: Obtain Values For URI Parameters

  4494. **

  4495. ** These are utility routines, useful to VFS implementations, that check

  4496. ** to see if a database file was a URI that contained a specific query 

  4497. ** parameter, and if so obtains the value of that query parameter.

  4498. **

  4499. ** If F is the database filename pointer passed into the xOpen() method of 

  4500. ** a VFS implementation when the flags parameter to xOpen() has one or 

  4501. ** more of the [SQLITE_OPEN_URI] or [SQLITE_OPEN_MAIN_DB] bits set and

  4502. ** P is the name of the query parameter, then

  4503. ** sqlite3_uri_parameter(F,P) returns the value of the P

  4504. ** parameter if it exists or a NULL pointer if P does not appear as a 

  4505. ** query parameter on F.  If P is a query parameter of F

  4506. ** has no explicit value, then sqlite3_uri_parameter(F,P) returns

  4507. ** a pointer to an empty string.

  4508. **

  4509. ** The sqlite3_uri_boolean(F,P,B) routine assumes that P is a boolean

  4510. ** parameter and returns true (1) or false (0) according to the value

  4511. ** of P.  The sqlite3_uri_boolean(F,P,B) routine returns true (1) if the

  4512. ** value of query parameter P is one of "yes", "true", or "on" in any

  4513. ** case or if the value begins with a non-zero number.  The 

  4514. ** sqlite3_uri_boolean(F,P,B) routines returns false (0) if the value of

  4515. ** query parameter P is one of "no", "false", or "off" in any case or

  4516. ** if the value begins with a numeric zero.  If P is not a query

  4517. ** parameter on F or if the value of P is does not match any of the

  4518. ** above, then sqlite3_uri_boolean(F,P,B) returns (B!=0).

  4519. **

  4520. ** The sqlite3_uri_int64(F,P,D) routine converts the value of P into a

  4521. ** 64-bit signed integer and returns that integer, or D if P does not

  4522. ** exist.  If the value of P is something other than an integer, then

  4523. ** zero is returned.

  4524. ** 

  4525. ** If F is a NULL pointer, then sqlite3_uri_parameter(F,P) returns NULL and

  4526. ** sqlite3_uri_boolean(F,P,B) returns B.  If F is not a NULL pointer and

  4527. ** is not a database file pathname pointer that SQLite passed into the xOpen

  4528. ** VFS method, then the behavior of this routine is undefined and probably

  4529. ** undesirable.

  4530. **

  4531. ** See the [URI filename] documentation for additional information.

  4532. */

  4533. SQLITE_API const char *sqlite3_uri_parameter(const char *zFilename, const char *zParam);

  4534. SQLITE_API int sqlite3_uri_boolean(const char *zFile, const char *zParam, int bDefault);

  4535. SQLITE_API sqlite3_int64 sqlite3_uri_int64(const char*, const char*, sqlite3_int64);

  4536. 

  4537. 

  4538. /*

  4539. ** CAPI3REF: Error Codes And Messages

  4540. ** METHOD: sqlite3

  4541. **

  4542. ** ^If the most recent sqlite3_* API call associated with 

  4543. ** [database connection] D failed, then the sqlite3_errcode(D) interface

  4544. ** returns the numeric [result code] or [extended result code] for that

  4545. ** API call.

  4546. ** ^The sqlite3_extended_errcode()

  4547. ** interface is the same except that it always returns the 

  4548. ** [extended result code] even when extended result codes are

  4549. ** disabled.

  4550. **

  4551. ** The values returned by sqlite3_errcode() and/or

  4552. ** sqlite3_extended_errcode() might change with each API call.

  4553. ** Except, there are some interfaces that are guaranteed to never

  4554. ** change the value of the error code.  The error-code preserving

  4555. ** interfaces are:

  4556. **

  4557. ** <ul>

  4558. ** <li> sqlite3_errcode()

  4559. ** <li> sqlite3_extended_errcode()

  4560. ** <li> sqlite3_errmsg()

  4561. ** <li> sqlite3_errmsg16()

  4562. ** </ul>

  4563. **

  4564. ** ^The sqlite3_errmsg() and sqlite3_errmsg16() return English-language

  4565. ** text that describes the error, as either UTF-8 or UTF-16 respectively.

  4566. ** ^(Memory to hold the error message string is managed internally.

  4567. ** The application does not need to worry about freeing the result.

  4568. ** However, the error string might be overwritten or deallocated by

  4569. ** subsequent calls to other SQLite interface functions.)^

  4570. **

  4571. ** ^The sqlite3_errstr() interface returns the English-language text

  4572. ** that describes the [result code], as UTF-8.

  4573. ** ^(Memory to hold the error message string is managed internally

  4574. ** and must not be freed by the application)^.

  4575. **

  4576. ** When the serialized [threading mode] is in use, it might be the

  4577. ** case that a second error occurs on a separate thread in between

  4578. ** the time of the first error and the call to these interfaces.

  4579. ** When that happens, the second error will be reported since these

  4580. ** interfaces always report the most recent result.  To avoid

  4581. ** this, each thread can obtain exclusive use of the [database connection] D

  4582. ** by invoking [sqlite3_mutex_enter]([sqlite3_db_mutex](D)) before beginning

  4583. ** to use D and invoking [sqlite3_mutex_leave]([sqlite3_db_mutex](D)) after

  4584. ** all calls to the interfaces listed here are completed.

  4585. **

  4586. ** If an interface fails with SQLITE_MISUSE, that means the interface

  4587. ** was invoked incorrectly by the application.  In that case, the

  4588. ** error code and message may or may not be set.

  4589. */

  4590. SQLITE_API int sqlite3_errcode(sqlite3 *db);

  4591. SQLITE_API int sqlite3_extended_errcode(sqlite3 *db);

  4592. SQLITE_API const char *sqlite3_errmsg(sqlite3*);

  4593. SQLITE_API const void *sqlite3_errmsg16(sqlite3*);

  4594. SQLITE_API const char *sqlite3_errstr(int);

  4595. 

  4596. /*

  4597. ** CAPI3REF: Prepared Statement Object

  4598. ** KEYWORDS: {prepared statement} {prepared statements}

  4599. **

  4600. ** An instance of this object represents a single SQL statement that

  4601. ** has been compiled into binary form and is ready to be evaluated.

  4602. **

  4603. ** Think of each SQL statement as a separate computer program.  The

  4604. ** original SQL text is source code.  A prepared statement object 

  4605. ** is the compiled object code.  All SQL must be converted into a

  4606. ** prepared statement before it can be run.

  4607. **

  4608. ** The life-cycle of a prepared statement object usually goes like this:

  4609. **

  4610. ** <ol>

  4611. ** <li> Create the prepared statement object using [sqlite3_prepare_v2()].

  4612. ** <li> Bind values to [parameters] using the sqlite3_bind_*()

  4613. **      interfaces.

  4614. ** <li> Run the SQL by calling [sqlite3_step()] one or more times.

  4615. ** <li> Reset the prepared statement using [sqlite3_reset()] then go back

  4616. **      to step 2.  Do this zero or more times.

  4617. ** <li> Destroy the object using [sqlite3_finalize()].

  4618. ** </ol>

  4619. */

  4620. typedef struct sqlite3_stmt sqlite3_stmt;

  4621. 

  4622. /*

  4623. ** CAPI3REF: Run-time Limits

  4624. ** METHOD: sqlite3

  4625. **

  4626. ** ^(This interface allows the size of various constructs to be limited

  4627. ** on a connection by connection basis.  The first parameter is the

  4628. ** [database connection] whose limit is to be set or queried.  The

  4629. ** second parameter is one of the [limit categories] that define a

  4630. ** class of constructs to be size limited.  The third parameter is the

  4631. ** new limit for that construct.)^

  4632. **

  4633. ** ^If the new limit is a negative number, the limit is unchanged.

  4634. ** ^(For each limit category SQLITE_LIMIT_<i>NAME</i> there is a 

  4635. ** [limits | hard upper bound]

  4636. ** set at compile-time by a C preprocessor macro called

  4637. ** [limits | SQLITE_MAX_<i>NAME</i>].

  4638. ** (The "_LIMIT_" in the name is changed to "_MAX_".))^

  4639. ** ^Attempts to increase a limit above its hard upper bound are

  4640. ** silently truncated to the hard upper bound.

  4641. **

  4642. ** ^Regardless of whether or not the limit was changed, the 

  4643. ** [sqlite3_limit()] interface returns the prior value of the limit.

  4644. ** ^Hence, to find the current value of a limit without changing it,

  4645. ** simply invoke this interface with the third parameter set to -1.

  4646. **

  4647. ** Run-time limits are intended for use in applications that manage

  4648. ** both their own internal database and also databases that are controlled

  4649. ** by untrusted external sources.  An example application might be a

  4650. ** web browser that has its own databases for storing history and

  4651. ** separate databases controlled by JavaScript applications downloaded

  4652. ** off the Internet.  The internal databases can be given the

  4653. ** large, default limits.  Databases managed by external sources can

  4654. ** be given much smaller limits designed to prevent a denial of service

  4655. ** attack.  Developers might also want to use the [sqlite3_set_authorizer()]

  4656. ** interface to further control untrusted SQL.  The size of the database

  4657. ** created by an untrusted script can be contained using the

  4658. ** [max_page_count] [PRAGMA].

  4659. **

  4660. ** New run-time limit categories may be added in future releases.

  4661. */

  4662. SQLITE_API int sqlite3_limit(sqlite3*, int id, int newVal);

  4663. 

  4664. /*

  4665. ** CAPI3REF: Run-Time Limit Categories

  4666. ** KEYWORDS: {limit category} {*limit categories}

  4667. **

  4668. ** These constants define various performance limits

  4669. ** that can be lowered at run-time using [sqlite3_limit()].

  4670. ** The synopsis of the meanings of the various limits is shown below.

  4671. ** Additional information is available at [limits | Limits in SQLite].

  4672. **

  4673. ** <dl>

  4674. ** [[SQLITE_LIMIT_LENGTH]] ^(<dt>SQLITE_LIMIT_LENGTH</dt>

  4675. ** <dd>The maximum size of any string or BLOB or table row, in bytes.<dd>)^

  4676. **

  4677. ** [[SQLITE_LIMIT_SQL_LENGTH]] ^(<dt>SQLITE_LIMIT_SQL_LENGTH</dt>

  4678. ** <dd>The maximum length of an SQL statement, in bytes.</dd>)^

  4679. **

  4680. ** [[SQLITE_LIMIT_COLUMN]] ^(<dt>SQLITE_LIMIT_COLUMN</dt>

  4681. ** <dd>The maximum number of columns in a table definition or in the

  4682. ** result set of a [SELECT] or the maximum number of columns in an index

  4683. ** or in an ORDER BY or GROUP BY clause.</dd>)^

  4684. **

  4685. ** [[SQLITE_LIMIT_EXPR_DEPTH]] ^(<dt>SQLITE_LIMIT_EXPR_DEPTH</dt>

  4686. ** <dd>The maximum depth of the parse tree on any expression.</dd>)^

  4687. **

  4688. ** [[SQLITE_LIMIT_COMPOUND_SELECT]] ^(<dt>SQLITE_LIMIT_COMPOUND_SELECT</dt>

  4689. ** <dd>The maximum number of terms in a compound SELECT statement.</dd>)^

  4690. **

  4691. ** [[SQLITE_LIMIT_VDBE_OP]] ^(<dt>SQLITE_LIMIT_VDBE_OP</dt>

  4692. ** <dd>The maximum number of instructions in a virtual machine program

  4693. ** used to implement an SQL statement.  If [sqlite3_prepare_v2()] or

  4694. ** the equivalent tries to allocate space for more than this many opcodes

  4695. ** in a single prepared statement, an SQLITE_NOMEM error is returned.</dd>)^

  4696. **

  4697. ** [[SQLITE_LIMIT_FUNCTION_ARG]] ^(<dt>SQLITE_LIMIT_FUNCTION_ARG</dt>

  4698. ** <dd>The maximum number of arguments on a function.</dd>)^

  4699. **

  4700. ** [[SQLITE_LIMIT_ATTACHED]] ^(<dt>SQLITE_LIMIT_ATTACHED</dt>

  4701. ** <dd>The maximum number of [ATTACH | attached databases].)^</dd>

  4702. **

  4703. ** [[SQLITE_LIMIT_LIKE_PATTERN_LENGTH]]

  4704. ** ^(<dt>SQLITE_LIMIT_LIKE_PATTERN_LENGTH</dt>

  4705. ** <dd>The maximum length of the pattern argument to the [LIKE] or

  4706. ** [GLOB] operators.</dd>)^

  4707. **

  4708. ** [[SQLITE_LIMIT_VARIABLE_NUMBER]]

  4709. ** ^(<dt>SQLITE_LIMIT_VARIABLE_NUMBER</dt>

  4710. ** <dd>The maximum index number of any [parameter] in an SQL statement.)^

  4711. **

  4712. ** [[SQLITE_LIMIT_TRIGGER_DEPTH]] ^(<dt>SQLITE_LIMIT_TRIGGER_DEPTH</dt>

  4713. ** <dd>The maximum depth of recursion for triggers.</dd>)^

  4714. **

  4715. ** [[SQLITE_LIMIT_WORKER_THREADS]] ^(<dt>SQLITE_LIMIT_WORKER_THREADS</dt>

  4716. ** <dd>The maximum number of auxiliary worker threads that a single

  4717. ** [prepared statement] may start.</dd>)^

  4718. ** </dl>

  4719. */

  4720. #define SQLITE_LIMIT_LENGTH                    0

  4721. #define SQLITE_LIMIT_SQL_LENGTH                1

  4722. #define SQLITE_LIMIT_COLUMN                    2

  4723. #define SQLITE_LIMIT_EXPR_DEPTH                3

  4724. #define SQLITE_LIMIT_COMPOUND_SELECT           4

  4725. #define SQLITE_LIMIT_VDBE_OP                   5

  4726. #define SQLITE_LIMIT_FUNCTION_ARG              6

  4727. #define SQLITE_LIMIT_ATTACHED                  7

  4728. #define SQLITE_LIMIT_LIKE_PATTERN_LENGTH       8

  4729. #define SQLITE_LIMIT_VARIABLE_NUMBER           9

  4730. #define SQLITE_LIMIT_TRIGGER_DEPTH            10

  4731. #define SQLITE_LIMIT_WORKER_THREADS           11

  4732. 

  4733. /*

  4734. ** CAPI3REF: Prepare Flags

  4735. **

  4736. ** These constants define various flags that can be passed into

  4737. ** "prepFlags" parameter of the [sqlite3_prepare_v3()] and

  4738. ** [sqlite3_prepare16_v3()] interfaces.

  4739. **

  4740. ** New flags may be added in future releases of SQLite.

  4741. **

  4742. ** <dl>

  4743. ** [[SQLITE_PREPARE_PERSISTENT]] ^(<dt>SQLITE_PREPARE_PERSISTENT</dt>

  4744. ** <dd>The SQLITE_PREPARE_PERSISTENT flag is a hint to the query planner

  4745. ** that the prepared statement will be retained for a long time and

  4746. ** probably reused many times.)^ ^Without this flag, [sqlite3_prepare_v3()]

  4747. ** and [sqlite3_prepare16_v3()] assume that the prepared statement will 

  4748. ** be used just once or at most a few times and then destroyed using

  4749. ** [sqlite3_finalize()] relatively soon. The current implementation acts

  4750. ** on this hint by avoiding the use of [lookaside memory] so as not to

  4751. ** deplete the limited store of lookaside memory. Future versions of

  4752. ** SQLite may act on this hint differently.

  4753. **

  4754. ** [[SQLITE_PREPARE_NORMALIZE]] <dt>SQLITE_PREPARE_NORMALIZE</dt>

  4755. ** <dd>The SQLITE_PREPARE_NORMALIZE flag is a no-op. This flag used

  4756. ** to be required for any prepared statement that wanted to use the

  4757. ** [sqlite3_normalized_sql()] interface.  However, the

  4758. ** [sqlite3_normalized_sql()] interface is now available to all

  4759. ** prepared statements, regardless of whether or not they use this

  4760. ** flag.

  4761. **

  4762. ** [[SQLITE_PREPARE_NO_VTAB]] <dt>SQLITE_PREPARE_NO_VTAB</dt>

  4763. ** <dd>The SQLITE_PREPARE_NO_VTAB flag causes the SQL compiler

  4764. ** to return an error (error code SQLITE_ERROR) if the statement uses

  4765. ** any virtual tables.

  4766. ** </dl>

  4767. */

  4768. #define SQLITE_PREPARE_PERSISTENT              0x01

  4769. #define SQLITE_PREPARE_NORMALIZE               0x02

  4770. #define SQLITE_PREPARE_NO_VTAB                 0x04

  4771. 

  4772. /*

  4773. ** CAPI3REF: Compiling An SQL Statement

  4774. ** KEYWORDS: {SQL statement compiler}

  4775. ** METHOD: sqlite3

  4776. ** CONSTRUCTOR: sqlite3_stmt

  4777. **

  4778. ** To execute an SQL statement, it must first be compiled into a byte-code

  4779. ** program using one of these routines.  Or, in other words, these routines

  4780. ** are constructors for the [prepared statement] object.

  4781. **

  4782. ** The preferred routine to use is [sqlite3_prepare_v2()].  The

  4783. ** [sqlite3_prepare()] interface is legacy and should be avoided.

  4784. ** [sqlite3_prepare_v3()] has an extra "prepFlags" option that is used

  4785. ** for special purposes.

  4786. **

  4787. ** The use of the UTF-8 interfaces is preferred, as SQLite currently

  4788. ** does all parsing using UTF-8.  The UTF-16 interfaces are provided

  4789. ** as a convenience.  The UTF-16 interfaces work by converting the

  4790. ** input text into UTF-8, then invoking the corresponding UTF-8 interface.

  4791. **

  4792. ** The first argument, "db", is a [database connection] obtained from a

  4793. ** prior successful call to [sqlite3_open()], [sqlite3_open_v2()] or

  4794. ** [sqlite3_open16()].  The database connection must not have been closed.

  4795. **

  4796. ** The second argument, "zSql", is the statement to be compiled, encoded

  4797. ** as either UTF-8 or UTF-16.  The sqlite3_prepare(), sqlite3_prepare_v2(),

  4798. ** and sqlite3_prepare_v3()

  4799. ** interfaces use UTF-8, and sqlite3_prepare16(), sqlite3_prepare16_v2(),

  4800. ** and sqlite3_prepare16_v3() use UTF-16.

  4801. **

  4802. ** ^If the nByte argument is negative, then zSql is read up to the

  4803. ** first zero terminator. ^If nByte is positive, then it is the

  4804. ** number of bytes read from zSql.  ^If nByte is zero, then no prepared

  4805. ** statement is generated.

  4806. ** If the caller knows that the supplied string is nul-terminated, then

  4807. ** there is a small performance advantage to passing an nByte parameter that

  4808. ** is the number of bytes in the input string <i>including</i>

  4809. ** the nul-terminator.

  4810. **

  4811. ** ^If pzTail is not NULL then *pzTail is made to point to the first byte

  4812. ** past the end of the first SQL statement in zSql.  These routines only

  4813. ** compile the first statement in zSql, so *pzTail is left pointing to

  4814. ** what remains uncompiled.

  4815. **

  4816. ** ^*ppStmt is left pointing to a compiled [prepared statement] that can be

  4817. ** executed using [sqlite3_step()].  ^If there is an error, *ppStmt is set

  4818. ** to NULL.  ^If the input text contains no SQL (if the input is an empty

  4819. ** string or a comment) then *ppStmt is set to NULL.

  4820. ** The calling procedure is responsible for deleting the compiled

  4821. ** SQL statement using [sqlite3_finalize()] after it has finished with it.

  4822. ** ppStmt may not be NULL.

  4823. **

  4824. ** ^On success, the sqlite3_prepare() family of routines return [SQLITE_OK];

  4825. ** otherwise an [error code] is returned.

  4826. **

  4827. ** The sqlite3_prepare_v2(), sqlite3_prepare_v3(), sqlite3_prepare16_v2(),

  4828. ** and sqlite3_prepare16_v3() interfaces are recommended for all new programs.

  4829. ** The older interfaces (sqlite3_prepare() and sqlite3_prepare16())

  4830. ** are retained for backwards compatibility, but their use is discouraged.

  4831. ** ^In the "vX" interfaces, the prepared statement

  4832. ** that is returned (the [sqlite3_stmt] object) contains a copy of the

  4833. ** original SQL text. This causes the [sqlite3_step()] interface to

  4834. ** behave differently in three ways:

  4835. **

  4836. ** <ol>

  4837. ** <li>

  4838. ** ^If the database schema changes, instead of returning [SQLITE_SCHEMA] as it

  4839. ** always used to do, [sqlite3_step()] will automatically recompile the SQL

  4840. ** statement and try to run it again. As many as [SQLITE_MAX_SCHEMA_RETRY]

  4841. ** retries will occur before sqlite3_step() gives up and returns an error.

  4842. ** </li>

  4843. **

  4844. ** <li>

  4845. ** ^When an error occurs, [sqlite3_step()] will return one of the detailed

  4846. ** [error codes] or [extended error codes].  ^The legacy behavior was that

  4847. ** [sqlite3_step()] would only return a generic [SQLITE_ERROR] result code

  4848. ** and the application would have to make a second call to [sqlite3_reset()]

  4849. ** in order to find the underlying cause of the problem. With the "v2" prepare

  4850. ** interfaces, the underlying reason for the error is returned immediately.

  4851. ** </li>

  4852. **

  4853. ** <li>

  4854. ** ^If the specific value bound to [parameter | host parameter] in the 

  4855. ** WHERE clause might influence the choice of query plan for a statement,

  4856. ** then the statement will be automatically recompiled, as if there had been 

  4857. ** a schema change, on the first  [sqlite3_step()] call following any change

  4858. ** to the [sqlite3_bind_text | bindings] of that [parameter]. 

  4859. ** ^The specific value of WHERE-clause [parameter] might influence the 

  4860. ** choice of query plan if the parameter is the left-hand side of a [LIKE]

  4861. ** or [GLOB] operator or if the parameter is compared to an indexed column

  4862. ** and the [SQLITE_ENABLE_STAT3] compile-time option is enabled.

  4863. ** </li>

  4864. ** </ol>

  4865. **

  4866. ** <p>^sqlite3_prepare_v3() differs from sqlite3_prepare_v2() only in having

  4867. ** the extra prepFlags parameter, which is a bit array consisting of zero or

  4868. ** more of the [SQLITE_PREPARE_PERSISTENT|SQLITE_PREPARE_*] flags.  ^The

  4869. ** sqlite3_prepare_v2() interface works exactly the same as

  4870. ** sqlite3_prepare_v3() with a zero prepFlags parameter.

  4871. */

  4872. SQLITE_API int sqlite3_prepare(

  4873.   sqlite3 *db,            /* Database handle */

  4874.   const char *zSql,       /* SQL statement, UTF-8 encoded */

  4875.   int nByte,              /* Maximum length of zSql in bytes. */

  4876.   sqlite3_stmt **ppStmt,  /* OUT: Statement handle */

  4877.   const char **pzTail     /* OUT: Pointer to unused portion of zSql */

  4878. );

  4879. SQLITE_API int sqlite3_prepare_v2(

  4880.   sqlite3 *db,            /* Database handle */

  4881.   const char *zSql,       /* SQL statement, UTF-8 encoded */

  4882.   int nByte,              /* Maximum length of zSql in bytes. */

  4883.   sqlite3_stmt **ppStmt,  /* OUT: Statement handle */

  4884.   const char **pzTail     /* OUT: Pointer to unused portion of zSql */

  4885. );

  4886. SQLITE_API int sqlite3_prepare_v3(

  4887.   sqlite3 *db,            /* Database handle */

  4888.   const char *zSql,       /* SQL statement, UTF-8 encoded */

  4889.   int nByte,              /* Maximum length of zSql in bytes. */

  4890.   unsigned int prepFlags, /* Zero or more SQLITE_PREPARE_ flags */

  4891.   sqlite3_stmt **ppStmt,  /* OUT: Statement handle */

  4892.   const char **pzTail     /* OUT: Pointer to unused portion of zSql */

  4893. );

  4894. SQLITE_API int sqlite3_prepare16(

  4895.   sqlite3 *db,            /* Database handle */

  4896.   const void *zSql,       /* SQL statement, UTF-16 encoded */

  4897.   int nByte,              /* Maximum length of zSql in bytes. */

  4898.   sqlite3_stmt **ppStmt,  /* OUT: Statement handle */

  4899.   const void **pzTail     /* OUT: Pointer to unused portion of zSql */

  4900. );

  4901. SQLITE_API int sqlite3_prepare16_v2(

  4902.   sqlite3 *db,            /* Database handle */

  4903.   const void *zSql,       /* SQL statement, UTF-16 encoded */

  4904.   int nByte,              /* Maximum length of zSql in bytes. */

  4905.   sqlite3_stmt **ppStmt,  /* OUT: Statement handle */

  4906.   const void **pzTail     /* OUT: Pointer to unused portion of zSql */

  4907. );

  4908. SQLITE_API int sqlite3_prepare16_v3(

  4909.   sqlite3 *db,            /* Database handle */

  4910.   const void *zSql,       /* SQL statement, UTF-16 encoded */

  4911.   int nByte,              /* Maximum length of zSql in bytes. */

  4912.   unsigned int prepFlags, /* Zero or more SQLITE_PREPARE_ flags */

  4913.   sqlite3_stmt **ppStmt,  /* OUT: Statement handle */

  4914.   const void **pzTail     /* OUT: Pointer to unused portion of zSql */

  4915. );

  4916. 

  4917. /*

  4918. ** CAPI3REF: Retrieving Statement SQL

  4919. ** METHOD: sqlite3_stmt

  4920. **

  4921. ** ^The sqlite3_sql(P) interface returns a pointer to a copy of the UTF-8

  4922. ** SQL text used to create [prepared statement] P if P was

  4923. ** created by [sqlite3_prepare_v2()], [sqlite3_prepare_v3()],

  4924. ** [sqlite3_prepare16_v2()], or [sqlite3_prepare16_v3()].

  4925. ** ^The sqlite3_expanded_sql(P) interface returns a pointer to a UTF-8

  4926. ** string containing the SQL text of prepared statement P with

  4927. ** [bound parameters] expanded.

  4928. ** ^The sqlite3_normalized_sql(P) interface returns a pointer to a UTF-8

  4929. ** string containing the normalized SQL text of prepared statement P.  The

  4930. ** semantics used to normalize a SQL statement are unspecified and subject

  4931. ** to change.  At a minimum, literal values will be replaced with suitable

  4932. ** placeholders.

  4933. **

  4934. ** ^(For example, if a prepared statement is created using the SQL

  4935. ** text "SELECT $abc,:xyz" and if parameter $abc is bound to integer 2345

  4936. ** and parameter :xyz is unbound, then sqlite3_sql() will return

  4937. ** the original string, "SELECT $abc,:xyz" but sqlite3_expanded_sql()

  4938. ** will return "SELECT 2345,NULL".)^

  4939. **

  4940. ** ^The sqlite3_expanded_sql() interface returns NULL if insufficient memory

  4941. ** is available to hold the result, or if the result would exceed the

  4942. ** the maximum string length determined by the [SQLITE_LIMIT_LENGTH].

  4943. **

  4944. ** ^The [SQLITE_TRACE_SIZE_LIMIT] compile-time option limits the size of

  4945. ** bound parameter expansions.  ^The [SQLITE_OMIT_TRACE] compile-time

  4946. ** option causes sqlite3_expanded_sql() to always return NULL.

  4947. **

  4948. ** ^The strings returned by sqlite3_sql(P) and sqlite3_normalized_sql(P)

  4949. ** are managed by SQLite and are automatically freed when the prepared

  4950. ** statement is finalized.

  4951. ** ^The string returned by sqlite3_expanded_sql(P), on the other hand,

  4952. ** is obtained from [sqlite3_malloc()] and must be free by the application

  4953. ** by passing it to [sqlite3_free()].

  4954. */

  4955. SQLITE_API const char *sqlite3_sql(sqlite3_stmt *pStmt);

  4956. SQLITE_API char *sqlite3_expanded_sql(sqlite3_stmt *pStmt);

  4957. SQLITE_API const char *sqlite3_normalized_sql(sqlite3_stmt *pStmt);

  4958. 

  4959. /*

  4960. ** CAPI3REF: Determine If An SQL Statement Writes The Database

  4961. ** METHOD: sqlite3_stmt

  4962. **

  4963. ** ^The sqlite3_stmt_readonly(X) interface returns true (non-zero) if

  4964. ** and only if the [prepared statement] X makes no direct changes to

  4965. ** the content of the database file.

  4966. **

  4967. ** Note that [application-defined SQL functions] or

  4968. ** [virtual tables] might change the database indirectly as a side effect.  

  4969. ** ^(For example, if an application defines a function "eval()" that 

  4970. ** calls [sqlite3_exec()], then the following SQL statement would

  4971. ** change the database file through side-effects:

  4972. **

  4973. ** <blockquote><pre>

  4974. **    SELECT eval('DELETE FROM t1') FROM t2;

  4975. ** </pre></blockquote>

  4976. **

  4977. ** But because the [SELECT] statement does not change the database file

  4978. ** directly, sqlite3_stmt_readonly() would still return true.)^

  4979. **

  4980. ** ^Transaction control statements such as [BEGIN], [COMMIT], [ROLLBACK],

  4981. ** [SAVEPOINT], and [RELEASE] cause sqlite3_stmt_readonly() to return true,

  4982. ** since the statements themselves do not actually modify the database but

  4983. ** rather they control the timing of when other statements modify the 

  4984. ** database.  ^The [ATTACH] and [DETACH] statements also cause

  4985. ** sqlite3_stmt_readonly() to return true since, while those statements

  4986. ** change the configuration of a database connection, they do not make 

  4987. ** changes to the content of the database files on disk.

  4988. ** ^The sqlite3_stmt_readonly() interface returns true for [BEGIN] since

  4989. ** [BEGIN] merely sets internal flags, but the [BEGIN|BEGIN IMMEDIATE] and

  4990. ** [BEGIN|BEGIN EXCLUSIVE] commands do touch the database and so

  4991. ** sqlite3_stmt_readonly() returns false for those commands.

  4992. */

  4993. SQLITE_API int sqlite3_stmt_readonly(sqlite3_stmt *pStmt);

  4994. 

  4995. /*

  4996. ** CAPI3REF: Query The EXPLAIN Setting For A Prepared Statement

  4997. ** METHOD: sqlite3_stmt

  4998. **

  4999. ** ^The sqlite3_stmt_isexplain(S) interface returns 1 if the

  5000. ** prepared statement S is an EXPLAIN statement, or 2 if the

  5001. ** statement S is an EXPLAIN QUERY PLAN.

  5002. ** ^The sqlite3_stmt_isexplain(S) interface returns 0 if S is

  5003. ** an ordinary statement or a NULL pointer.

  5004. */

  5005. SQLITE_API int sqlite3_stmt_isexplain(sqlite3_stmt *pStmt);

  5006. 

  5007. /*

  5008. ** CAPI3REF: Determine If A Prepared Statement Has Been Reset

  5009. ** METHOD: sqlite3_stmt

  5010. **

  5011. ** ^The sqlite3_stmt_busy(S) interface returns true (non-zero) if the

  5012. ** [prepared statement] S has been stepped at least once using 

  5013. ** [sqlite3_step(S)] but has neither run to completion (returned

  5014. ** [SQLITE_DONE] from [sqlite3_step(S)]) nor

  5015. ** been reset using [sqlite3_reset(S)].  ^The sqlite3_stmt_busy(S)

  5016. ** interface returns false if S is a NULL pointer.  If S is not a 

  5017. ** NULL pointer and is not a pointer to a valid [prepared statement]

  5018. ** object, then the behavior is undefined and probably undesirable.

  5019. **

  5020. ** This interface can be used in combination [sqlite3_next_stmt()]

  5021. ** to locate all prepared statements associated with a database 

  5022. ** connection that are in need of being reset.  This can be used,

  5023. ** for example, in diagnostic routines to search for prepared 

  5024. ** statements that are holding a transaction open.

  5025. */

  5026. SQLITE_API int sqlite3_stmt_busy(sqlite3_stmt*);

  5027. 

  5028. /*

  5029. ** CAPI3REF: Dynamically Typed Value Object

  5030. ** KEYWORDS: {protected sqlite3_value} {unprotected sqlite3_value}

  5031. **

  5032. ** SQLite uses the sqlite3_value object to represent all values

  5033. ** that can be stored in a database table. SQLite uses dynamic typing

  5034. ** for the values it stores.  ^Values stored in sqlite3_value objects

  5035. ** can be integers, floating point values, strings, BLOBs, or NULL.

  5036. **

  5037. ** An sqlite3_value object may be either "protected" or "unprotected".

  5038. ** Some interfaces require a protected sqlite3_value.  Other interfaces

  5039. ** will accept either a protected or an unprotected sqlite3_value.

  5040. ** Every interface that accepts sqlite3_value arguments specifies

  5041. ** whether or not it requires a protected sqlite3_value.  The

  5042. ** [sqlite3_value_dup()] interface can be used to construct a new 

  5043. ** protected sqlite3_value from an unprotected sqlite3_value.

  5044. **

  5045. ** The terms "protected" and "unprotected" refer to whether or not

  5046. ** a mutex is held.  An internal mutex is held for a protected

  5047. ** sqlite3_value object but no mutex is held for an unprotected

  5048. ** sqlite3_value object.  If SQLite is compiled to be single-threaded

  5049. ** (with [SQLITE_THREADSAFE=0] and with [sqlite3_threadsafe()] returning 0)

  5050. ** or if SQLite is run in one of reduced mutex modes 

  5051. ** [SQLITE_CONFIG_SINGLETHREAD] or [SQLITE_CONFIG_MULTITHREAD]

  5052. ** then there is no distinction between protected and unprotected

  5053. ** sqlite3_value objects and they can be used interchangeably.  However,

  5054. ** for maximum code portability it is recommended that applications

  5055. ** still make the distinction between protected and unprotected

  5056. ** sqlite3_value objects even when not strictly required.

  5057. **

  5058. ** ^The sqlite3_value objects that are passed as parameters into the

  5059. ** implementation of [application-defined SQL functions] are protected.

  5060. ** ^The sqlite3_value object returned by

  5061. ** [sqlite3_column_value()] is unprotected.

  5062. ** Unprotected sqlite3_value objects may only be used as arguments

  5063. ** to [sqlite3_result_value()], [sqlite3_bind_value()], and

  5064. ** [sqlite3_value_dup()].

  5065. ** The [sqlite3_value_blob | sqlite3_value_type()] family of

  5066. ** interfaces require protected sqlite3_value objects.

  5067. */

  5068. typedef struct sqlite3_value sqlite3_value;

  5069. 

  5070. /*

  5071. ** CAPI3REF: SQL Function Context Object

  5072. **

  5073. ** The context in which an SQL function executes is stored in an

  5074. ** sqlite3_context object.  ^A pointer to an sqlite3_context object

  5075. ** is always first parameter to [application-defined SQL functions].

  5076. ** The application-defined SQL function implementation will pass this

  5077. ** pointer through into calls to [sqlite3_result_int | sqlite3_result()],

  5078. ** [sqlite3_aggregate_context()], [sqlite3_user_data()],

  5079. ** [sqlite3_context_db_handle()], [sqlite3_get_auxdata()],

  5080. ** and/or [sqlite3_set_auxdata()].

  5081. */

  5082. typedef struct sqlite3_context sqlite3_context;

  5083. 

  5084. /*

  5085. ** CAPI3REF: Binding Values To Prepared Statements

  5086. ** KEYWORDS: {host parameter} {host parameters} {host parameter name}

  5087. ** KEYWORDS: {SQL parameter} {SQL parameters} {parameter binding}

  5088. ** METHOD: sqlite3_stmt

  5089. **

  5090. ** ^(In the SQL statement text input to [sqlite3_prepare_v2()] and its variants,

  5091. ** literals may be replaced by a [parameter] that matches one of following

  5092. ** templates:

  5093. **

  5094. ** <ul>

  5095. ** <li>  ?

  5096. ** <li>  ?NNN

  5097. ** <li>  :VVV

  5098. ** <li>  @VVV

  5099. ** <li>  $VVV

  5100. ** </ul>

  5101. **

  5102. ** In the templates above, NNN represents an integer literal,

  5103. ** and VVV represents an alphanumeric identifier.)^  ^The values of these

  5104. ** parameters (also called "host parameter names" or "SQL parameters")

  5105. ** can be set using the sqlite3_bind_*() routines defined here.

  5106. **

  5107. ** ^The first argument to the sqlite3_bind_*() routines is always

  5108. ** a pointer to the [sqlite3_stmt] object returned from

  5109. ** [sqlite3_prepare_v2()] or its variants.

  5110. **

  5111. ** ^The second argument is the index of the SQL parameter to be set.

  5112. ** ^The leftmost SQL parameter has an index of 1.  ^When the same named

  5113. ** SQL parameter is used more than once, second and subsequent

  5114. ** occurrences have the same index as the first occurrence.

  5115. ** ^The index for named parameters can be looked up using the

  5116. ** [sqlite3_bind_parameter_index()] API if desired.  ^The index

  5117. ** for "?NNN" parameters is the value of NNN.

  5118. ** ^The NNN value must be between 1 and the [sqlite3_limit()]

  5119. ** parameter [SQLITE_LIMIT_VARIABLE_NUMBER] (default value: 999).

  5120. **

  5121. ** ^The third argument is the value to bind to the parameter.

  5122. ** ^If the third parameter to sqlite3_bind_text() or sqlite3_bind_text16()

  5123. ** or sqlite3_bind_blob() is a NULL pointer then the fourth parameter

  5124. ** is ignored and the end result is the same as sqlite3_bind_null().

  5125. **

  5126. ** ^(In those routines that have a fourth argument, its value is the

  5127. ** number of bytes in the parameter.  To be clear: the value is the

  5128. ** number of <u>bytes</u> in the value, not the number of characters.)^

  5129. ** ^If the fourth parameter to sqlite3_bind_text() or sqlite3_bind_text16()

  5130. ** is negative, then the length of the string is

  5131. ** the number of bytes up to the first zero terminator.

  5132. ** If the fourth parameter to sqlite3_bind_blob() is negative, then

  5133. ** the behavior is undefined.

  5134. ** If a non-negative fourth parameter is provided to sqlite3_bind_text()

  5135. ** or sqlite3_bind_text16() or sqlite3_bind_text64() then

  5136. ** that parameter must be the byte offset

  5137. ** where the NUL terminator would occur assuming the string were NUL

  5138. ** terminated.  If any NUL characters occur at byte offsets less than 

  5139. ** the value of the fourth parameter then the resulting string value will

  5140. ** contain embedded NULs.  The result of expressions involving strings

  5141. ** with embedded NULs is undefined.

  5142. **

  5143. ** ^The fifth argument to the BLOB and string binding interfaces

  5144. ** is a destructor used to dispose of the BLOB or

  5145. ** string after SQLite has finished with it.  ^The destructor is called

  5146. ** to dispose of the BLOB or string even if the call to the bind API fails,

  5147. ** except the destructor is not called if the third parameter is a NULL

  5148. ** pointer or the fourth parameter is negative.

  5149. ** ^If the fifth argument is

  5150. ** the special value [SQLITE_STATIC], then SQLite assumes that the

  5151. ** information is in static, unmanaged space and does not need to be freed.

  5152. ** ^If the fifth argument has the value [SQLITE_TRANSIENT], then

  5153. ** SQLite makes its own private copy of the data immediately, before

  5154. ** the sqlite3_bind_*() routine returns.

  5155. **

  5156. ** ^The sixth argument to sqlite3_bind_text64() must be one of

  5157. ** [SQLITE_UTF8], [SQLITE_UTF16], [SQLITE_UTF16BE], or [SQLITE_UTF16LE]

  5158. ** to specify the encoding of the text in the third parameter.  If

  5159. ** the sixth argument to sqlite3_bind_text64() is not one of the

  5160. ** allowed values shown above, or if the text encoding is different

  5161. ** from the encoding specified by the sixth parameter, then the behavior

  5162. ** is undefined.

  5163. **

  5164. ** ^The sqlite3_bind_zeroblob() routine binds a BLOB of length N that

  5165. ** is filled with zeroes.  ^A zeroblob uses a fixed amount of memory

  5166. ** (just an integer to hold its size) while it is being processed.

  5167. ** Zeroblobs are intended to serve as placeholders for BLOBs whose

  5168. ** content is later written using

  5169. ** [sqlite3_blob_open | incremental BLOB I/O] routines.

  5170. ** ^A negative value for the zeroblob results in a zero-length BLOB.

  5171. **

  5172. ** ^The sqlite3_bind_pointer(S,I,P,T,D) routine causes the I-th parameter in

  5173. ** [prepared statement] S to have an SQL value of NULL, but to also be

  5174. ** associated with the pointer P of type T.  ^D is either a NULL pointer or

  5175. ** a pointer to a destructor function for P. ^SQLite will invoke the

  5176. ** destructor D with a single argument of P when it is finished using

  5177. ** P.  The T parameter should be a static string, preferably a string

  5178. ** literal. The sqlite3_bind_pointer() routine is part of the

  5179. ** [pointer passing interface] added for SQLite 3.20.0.

  5180. **

  5181. ** ^If any of the sqlite3_bind_*() routines are called with a NULL pointer

  5182. ** for the [prepared statement] or with a prepared statement for which

  5183. ** [sqlite3_step()] has been called more recently than [sqlite3_reset()],

  5184. ** then the call will return [SQLITE_MISUSE].  If any sqlite3_bind_()

  5185. ** routine is passed a [prepared statement] that has been finalized, the

  5186. ** result is undefined and probably harmful.

  5187. **

  5188. ** ^Bindings are not cleared by the [sqlite3_reset()] routine.

  5189. ** ^Unbound parameters are interpreted as NULL.

  5190. **

  5191. ** ^The sqlite3_bind_* routines return [SQLITE_OK] on success or an

  5192. ** [error code] if anything goes wrong.

  5193. ** ^[SQLITE_TOOBIG] might be returned if the size of a string or BLOB

  5194. ** exceeds limits imposed by [sqlite3_limit]([SQLITE_LIMIT_LENGTH]) or

  5195. ** [SQLITE_MAX_LENGTH].

  5196. ** ^[SQLITE_RANGE] is returned if the parameter

  5197. ** index is out of range.  ^[SQLITE_NOMEM] is returned if malloc() fails.

  5198. **

  5199. ** See also: [sqlite3_bind_parameter_count()],

  5200. ** [sqlite3_bind_parameter_name()], and [sqlite3_bind_parameter_index()].

  5201. */

  5202. SQLITE_API int sqlite3_bind_blob(sqlite3_stmt*, int, const void*, int n, void(*)(void*));

  5203. SQLITE_API int sqlite3_bind_blob64(sqlite3_stmt*, int, const void*, sqlite3_uint64,

  5204.                         void(*)(void*));

  5205. SQLITE_API int sqlite3_bind_double(sqlite3_stmt*, int, double);

  5206. SQLITE_API int sqlite3_bind_int(sqlite3_stmt*, int, int);

  5207. SQLITE_API int sqlite3_bind_int64(sqlite3_stmt*, int, sqlite3_int64);

  5208. SQLITE_API int sqlite3_bind_null(sqlite3_stmt*, int);

  5209. SQLITE_API int sqlite3_bind_text(sqlite3_stmt*,int,const char*,int,void(*)(void*));

  5210. SQLITE_API int sqlite3_bind_text16(sqlite3_stmt*, int, const void*, int, void(*)(void*));

  5211. SQLITE_API int sqlite3_bind_text64(sqlite3_stmt*, int, const char*, sqlite3_uint64,

  5212.                          void(*)(void*), unsigned char encoding);

  5213. SQLITE_API int sqlite3_bind_value(sqlite3_stmt*, int, const sqlite3_value*);

  5214. SQLITE_API int sqlite3_bind_pointer(sqlite3_stmt*, int, void*, const char*,void(*)(void*));

  5215. SQLITE_API int sqlite3_bind_zeroblob(sqlite3_stmt*, int, int n);

  5216. SQLITE_API int sqlite3_bind_zeroblob64(sqlite3_stmt*, int, sqlite3_uint64);

  5217. 

  5218. /*

  5219. ** CAPI3REF: Number Of SQL Parameters

  5220. ** METHOD: sqlite3_stmt

  5221. **

  5222. ** ^This routine can be used to find the number of [SQL parameters]

  5223. ** in a [prepared statement].  SQL parameters are tokens of the

  5224. ** form "?", "?NNN", ":AAA", "$AAA", or "@AAA" that serve as

  5225. ** placeholders for values that are [sqlite3_bind_blob | bound]

  5226. ** to the parameters at a later time.

  5227. **

  5228. ** ^(This routine actually returns the index of the largest (rightmost)

  5229. ** parameter. For all forms except ?NNN, this will correspond to the

  5230. ** number of unique parameters.  If parameters of the ?NNN form are used,

  5231. ** there may be gaps in the list.)^

  5232. **

  5233. ** See also: [sqlite3_bind_blob|sqlite3_bind()],

  5234. ** [sqlite3_bind_parameter_name()], and

  5235. ** [sqlite3_bind_parameter_index()].

  5236. */

  5237. SQLITE_API int sqlite3_bind_parameter_count(sqlite3_stmt*);

  5238. 

  5239. /*

  5240. ** CAPI3REF: Name Of A Host Parameter

  5241. ** METHOD: sqlite3_stmt

  5242. **

  5243. ** ^The sqlite3_bind_parameter_name(P,N) interface returns

  5244. ** the name of the N-th [SQL parameter] in the [prepared statement] P.

  5245. ** ^(SQL parameters of the form "?NNN" or ":AAA" or "@AAA" or "$AAA"

  5246. ** have a name which is the string "?NNN" or ":AAA" or "@AAA" or "$AAA"

  5247. ** respectively.

  5248. ** In other words, the initial ":" or "$" or "@" or "?"

  5249. ** is included as part of the name.)^

  5250. ** ^Parameters of the form "?" without a following integer have no name

  5251. ** and are referred to as "nameless" or "anonymous parameters".

  5252. **

  5253. ** ^The first host parameter has an index of 1, not 0.

  5254. **

  5255. ** ^If the value N is out of range or if the N-th parameter is

  5256. ** nameless, then NULL is returned.  ^The returned string is

  5257. ** always in UTF-8 encoding even if the named parameter was

  5258. ** originally specified as UTF-16 in [sqlite3_prepare16()],

  5259. ** [sqlite3_prepare16_v2()], or [sqlite3_prepare16_v3()].

  5260. **

  5261. ** See also: [sqlite3_bind_blob|sqlite3_bind()],

  5262. ** [sqlite3_bind_parameter_count()], and

  5263. ** [sqlite3_bind_parameter_index()].

  5264. */

  5265. SQLITE_API const char *sqlite3_bind_parameter_name(sqlite3_stmt*, int);

  5266. 

  5267. /*

  5268. ** CAPI3REF: Index Of A Parameter With A Given Name

  5269. ** METHOD: sqlite3_stmt

  5270. **

  5271. ** ^Return the index of an SQL parameter given its name.  ^The

  5272. ** index value returned is suitable for use as the second

  5273. ** parameter to [sqlite3_bind_blob|sqlite3_bind()].  ^A zero

  5274. ** is returned if no matching parameter is found.  ^The parameter

  5275. ** name must be given in UTF-8 even if the original statement

  5276. ** was prepared from UTF-16 text using [sqlite3_prepare16_v2()] or

  5277. ** [sqlite3_prepare16_v3()].

  5278. **

  5279. ** See also: [sqlite3_bind_blob|sqlite3_bind()],

  5280. ** [sqlite3_bind_parameter_count()], and

  5281. ** [sqlite3_bind_parameter_name()].

  5282. */

  5283. SQLITE_API int sqlite3_bind_parameter_index(sqlite3_stmt*, const char *zName);

  5284. 

  5285. /*

  5286. ** CAPI3REF: Reset All Bindings On A Prepared Statement

  5287. ** METHOD: sqlite3_stmt

  5288. **

  5289. ** ^Contrary to the intuition of many, [sqlite3_reset()] does not reset

  5290. ** the [sqlite3_bind_blob | bindings] on a [prepared statement].

  5291. ** ^Use this routine to reset all host parameters to NULL.

  5292. */

  5293. SQLITE_API int sqlite3_clear_bindings(sqlite3_stmt*);

  5294. 

  5295. /*

  5296. ** CAPI3REF: Number Of Columns In A Result Set

  5297. ** METHOD: sqlite3_stmt

  5298. **

  5299. ** ^Return the number of columns in the result set returned by the

  5300. ** [prepared statement]. ^If this routine returns 0, that means the 

  5301. ** [prepared statement] returns no data (for example an [UPDATE]).

  5302. ** ^However, just because this routine returns a positive number does not

  5303. ** mean that one or more rows of data will be returned.  ^A SELECT statement

  5304. ** will always have a positive sqlite3_column_count() but depending on the

  5305. ** WHERE clause constraints and the table content, it might return no rows.

  5306. **

  5307. ** See also: [sqlite3_data_count()]

  5308. */

  5309. SQLITE_API int sqlite3_column_count(sqlite3_stmt *pStmt);

  5310. 

  5311. /*

  5312. ** CAPI3REF: Column Names In A Result Set

  5313. ** METHOD: sqlite3_stmt

  5314. **

  5315. ** ^These routines return the name assigned to a particular column

  5316. ** in the result set of a [SELECT] statement.  ^The sqlite3_column_name()

  5317. ** interface returns a pointer to a zero-terminated UTF-8 string

  5318. ** and sqlite3_column_name16() returns a pointer to a zero-terminated

  5319. ** UTF-16 string.  ^The first parameter is the [prepared statement]

  5320. ** that implements the [SELECT] statement. ^The second parameter is the

  5321. ** column number.  ^The leftmost column is number 0.

  5322. **

  5323. ** ^The returned string pointer is valid until either the [prepared statement]

  5324. ** is destroyed by [sqlite3_finalize()] or until the statement is automatically

  5325. ** reprepared by the first call to [sqlite3_step()] for a particular run

  5326. ** or until the next call to

  5327. ** sqlite3_column_name() or sqlite3_column_name16() on the same column.

  5328. **

  5329. ** ^If sqlite3_malloc() fails during the processing of either routine

  5330. ** (for example during a conversion from UTF-8 to UTF-16) then a

  5331. ** NULL pointer is returned.

  5332. **

  5333. ** ^The name of a result column is the value of the "AS" clause for

  5334. ** that column, if there is an AS clause.  If there is no AS clause

  5335. ** then the name of the column is unspecified and may change from

  5336. ** one release of SQLite to the next.

  5337. */

  5338. SQLITE_API const char *sqlite3_column_name(sqlite3_stmt*, int N);

  5339. SQLITE_API const void *sqlite3_column_name16(sqlite3_stmt*, int N);

  5340. 

  5341. /*

  5342. ** CAPI3REF: Source Of Data In A Query Result

  5343. ** METHOD: sqlite3_stmt

  5344. **

  5345. ** ^These routines provide a means to determine the database, table, and

  5346. ** table column that is the origin of a particular result column in

  5347. ** [SELECT] statement.

  5348. ** ^The name of the database or table or column can be returned as

  5349. ** either a UTF-8 or UTF-16 string.  ^The _database_ routines return

  5350. ** the database name, the _table_ routines return the table name, and

  5351. ** the origin_ routines return the column name.

  5352. ** ^The returned string is valid until the [prepared statement] is destroyed

  5353. ** using [sqlite3_finalize()] or until the statement is automatically

  5354. ** reprepared by the first call to [sqlite3_step()] for a particular run

  5355. ** or until the same information is requested

  5356. ** again in a different encoding.

  5357. **

  5358. ** ^The names returned are the original un-aliased names of the

  5359. ** database, table, and column.

  5360. **

  5361. ** ^The first argument to these interfaces is a [prepared statement].

  5362. ** ^These functions return information about the Nth result column returned by

  5363. ** the statement, where N is the second function argument.

  5364. ** ^The left-most column is column 0 for these routines.

  5365. **

  5366. ** ^If the Nth column returned by the statement is an expression or

  5367. ** subquery and is not a column value, then all of these functions return

  5368. ** NULL.  ^These routine might also return NULL if a memory allocation error

  5369. ** occurs.  ^Otherwise, they return the name of the attached database, table,

  5370. ** or column that query result column was extracted from.

  5371. **

  5372. ** ^As with all other SQLite APIs, those whose names end with "16" return

  5373. ** UTF-16 encoded strings and the other functions return UTF-8.

  5374. **

  5375. ** ^These APIs are only available if the library was compiled with the

  5376. ** [SQLITE_ENABLE_COLUMN_METADATA] C-preprocessor symbol.

  5377. **

  5378. ** If two or more threads call one or more of these routines against the same

  5379. ** prepared statement and column at the same time then the results are

  5380. ** undefined.

  5381. **

  5382. ** If two or more threads call one or more

  5383. ** [sqlite3_column_database_name | column metadata interfaces]

  5384. ** for the same [prepared statement] and result column

  5385. ** at the same time then the results are undefined.

  5386. */

  5387. SQLITE_API const char *sqlite3_column_database_name(sqlite3_stmt*,int);

  5388. SQLITE_API const void *sqlite3_column_database_name16(sqlite3_stmt*,int);

  5389. SQLITE_API const char *sqlite3_column_table_name(sqlite3_stmt*,int);

  5390. SQLITE_API const void *sqlite3_column_table_name16(sqlite3_stmt*,int);

  5391. SQLITE_API const char *sqlite3_column_origin_name(sqlite3_stmt*,int);

  5392. SQLITE_API const void *sqlite3_column_origin_name16(sqlite3_stmt*,int);

  5393. 

  5394. /*

  5395. ** CAPI3REF: Declared Datatype Of A Query Result

  5396. ** METHOD: sqlite3_stmt

  5397. **

  5398. ** ^(The first parameter is a [prepared statement].

  5399. ** If this statement is a [SELECT] statement and the Nth column of the

  5400. ** returned result set of that [SELECT] is a table column (not an

  5401. ** expression or subquery) then the declared type of the table

  5402. ** column is returned.)^  ^If the Nth column of the result set is an

  5403. ** expression or subquery, then a NULL pointer is returned.

  5404. ** ^The returned string is always UTF-8 encoded.

  5405. **

  5406. ** ^(For example, given the database schema:

  5407. **

  5408. ** CREATE TABLE t1(c1 VARIANT);

  5409. **

  5410. ** and the following statement to be compiled:

  5411. **

  5412. ** SELECT c1 + 1, c1 FROM t1;

  5413. **

  5414. ** this routine would return the string "VARIANT" for the second result

  5415. ** column (i==1), and a NULL pointer for the first result column (i==0).)^

  5416. **

  5417. ** ^SQLite uses dynamic run-time typing.  ^So just because a column

  5418. ** is declared to contain a particular type does not mean that the

  5419. ** data stored in that column is of the declared type.  SQLite is

  5420. ** strongly typed, but the typing is dynamic not static.  ^Type

  5421. ** is associated with individual values, not with the containers

  5422. ** used to hold those values.

  5423. */

  5424. SQLITE_API const char *sqlite3_column_decltype(sqlite3_stmt*,int);

  5425. SQLITE_API const void *sqlite3_column_decltype16(sqlite3_stmt*,int);

  5426. 

  5427. /*

  5428. ** CAPI3REF: Evaluate An SQL Statement

  5429. ** METHOD: sqlite3_stmt

  5430. **

  5431. ** After a [prepared statement] has been prepared using any of

  5432. ** [sqlite3_prepare_v2()], [sqlite3_prepare_v3()], [sqlite3_prepare16_v2()],

  5433. ** or [sqlite3_prepare16_v3()] or one of the legacy

  5434. ** interfaces [sqlite3_prepare()] or [sqlite3_prepare16()], this function

  5435. ** must be called one or more times to evaluate the statement.

  5436. **

  5437. ** The details of the behavior of the sqlite3_step() interface depend

  5438. ** on whether the statement was prepared using the newer "vX" interfaces

  5439. ** [sqlite3_prepare_v3()], [sqlite3_prepare_v2()], [sqlite3_prepare16_v3()],

  5440. ** [sqlite3_prepare16_v2()] or the older legacy

  5441. ** interfaces [sqlite3_prepare()] and [sqlite3_prepare16()].  The use of the

  5442. ** new "vX" interface is recommended for new applications but the legacy

  5443. ** interface will continue to be supported.

  5444. **

  5445. ** ^In the legacy interface, the return value will be either [SQLITE_BUSY],

  5446. ** [SQLITE_DONE], [SQLITE_ROW], [SQLITE_ERROR], or [SQLITE_MISUSE].

  5447. ** ^With the "v2" interface, any of the other [result codes] or

  5448. ** [extended result codes] might be returned as well.

  5449. **

  5450. ** ^[SQLITE_BUSY] means that the database engine was unable to acquire the

  5451. ** database locks it needs to do its job.  ^If the statement is a [COMMIT]

  5452. ** or occurs outside of an explicit transaction, then you can retry the

  5453. ** statement.  If the statement is not a [COMMIT] and occurs within an

  5454. ** explicit transaction then you should rollback the transaction before

  5455. ** continuing.

  5456. **

  5457. ** ^[SQLITE_DONE] means that the statement has finished executing

  5458. ** successfully.  sqlite3_step() should not be called again on this virtual

  5459. ** machine without first calling [sqlite3_reset()] to reset the virtual

  5460. ** machine back to its initial state.

  5461. **

  5462. ** ^If the SQL statement being executed returns any data, then [SQLITE_ROW]

  5463. ** is returned each time a new row of data is ready for processing by the

  5464. ** caller. The values may be accessed using the [column access functions].

  5465. ** sqlite3_step() is called again to retrieve the next row of data.

  5466. **

  5467. ** ^[SQLITE_ERROR] means that a run-time error (such as a constraint

  5468. ** violation) has occurred.  sqlite3_step() should not be called again on

  5469. ** the VM. More information may be found by calling [sqlite3_errmsg()].

  5470. ** ^With the legacy interface, a more specific error code (for example,

  5471. ** [SQLITE_INTERRUPT], [SQLITE_SCHEMA], [SQLITE_CORRUPT], and so forth)

  5472. ** can be obtained by calling [sqlite3_reset()] on the

  5473. ** [prepared statement].  ^In the "v2" interface,

  5474. ** the more specific error code is returned directly by sqlite3_step().

  5475. **

  5476. ** [SQLITE_MISUSE] means that the this routine was called inappropriately.

  5477. ** Perhaps it was called on a [prepared statement] that has

  5478. ** already been [sqlite3_finalize | finalized] or on one that had

  5479. ** previously returned [SQLITE_ERROR] or [SQLITE_DONE].  Or it could

  5480. ** be the case that the same database connection is being used by two or

  5481. ** more threads at the same moment in time.

  5482. **

  5483. ** For all versions of SQLite up to and including 3.6.23.1, a call to

  5484. ** [sqlite3_reset()] was required after sqlite3_step() returned anything

  5485. ** other than [SQLITE_ROW] before any subsequent invocation of

  5486. ** sqlite3_step().  Failure to reset the prepared statement using 

  5487. ** [sqlite3_reset()] would result in an [SQLITE_MISUSE] return from

  5488. ** sqlite3_step().  But after [version 3.6.23.1] ([dateof:3.6.23.1],

  5489. ** sqlite3_step() began

  5490. ** calling [sqlite3_reset()] automatically in this circumstance rather

  5491. ** than returning [SQLITE_MISUSE].  This is not considered a compatibility

  5492. ** break because any application that ever receives an SQLITE_MISUSE error

  5493. ** is broken by definition.  The [SQLITE_OMIT_AUTORESET] compile-time option

  5494. ** can be used to restore the legacy behavior.

  5495. **

  5496. ** <b>Goofy Interface Alert:</b> In the legacy interface, the sqlite3_step()

  5497. ** API always returns a generic error code, [SQLITE_ERROR], following any

  5498. ** error other than [SQLITE_BUSY] and [SQLITE_MISUSE].  You must call

  5499. ** [sqlite3_reset()] or [sqlite3_finalize()] in order to find one of the

  5500. ** specific [error codes] that better describes the error.

  5501. ** We admit that this is a goofy design.  The problem has been fixed

  5502. ** with the "v2" interface.  If you prepare all of your SQL statements

  5503. ** using [sqlite3_prepare_v3()] or [sqlite3_prepare_v2()]

  5504. ** or [sqlite3_prepare16_v2()] or [sqlite3_prepare16_v3()] instead

  5505. ** of the legacy [sqlite3_prepare()] and [sqlite3_prepare16()] interfaces,

  5506. ** then the more specific [error codes] are returned directly

  5507. ** by sqlite3_step().  The use of the "vX" interfaces is recommended.

  5508. */

  5509. SQLITE_API int sqlite3_step(sqlite3_stmt*);

  5510. 

  5511. /*

  5512. ** CAPI3REF: Number of columns in a result set

  5513. ** METHOD: sqlite3_stmt

  5514. **

  5515. ** ^The sqlite3_data_count(P) interface returns the number of columns in the

  5516. ** current row of the result set of [prepared statement] P.

  5517. ** ^If prepared statement P does not have results ready to return

  5518. ** (via calls to the [sqlite3_column_int | sqlite3_column_*()] of

  5519. ** interfaces) then sqlite3_data_count(P) returns 0.

  5520. ** ^The sqlite3_data_count(P) routine also returns 0 if P is a NULL pointer.

  5521. ** ^The sqlite3_data_count(P) routine returns 0 if the previous call to

  5522. ** [sqlite3_step](P) returned [SQLITE_DONE].  ^The sqlite3_data_count(P)

  5523. ** will return non-zero if previous call to [sqlite3_step](P) returned

  5524. ** [SQLITE_ROW], except in the case of the [PRAGMA incremental_vacuum]

  5525. ** where it always returns zero since each step of that multi-step

  5526. ** pragma returns 0 columns of data.

  5527. **

  5528. ** See also: [sqlite3_column_count()]

  5529. */

  5530. SQLITE_API int sqlite3_data_count(sqlite3_stmt *pStmt);

  5531. 

  5532. /*

  5533. ** CAPI3REF: Fundamental Datatypes

  5534. ** KEYWORDS: SQLITE_TEXT

  5535. **

  5536. ** ^(Every value in SQLite has one of five fundamental datatypes:

  5537. **

  5538. ** <ul>

  5539. ** <li> 64-bit signed integer

  5540. ** <li> 64-bit IEEE floating point number

  5541. ** <li> string

  5542. ** <li> BLOB

  5543. ** <li> NULL

  5544. ** </ul>)^

  5545. **

  5546. ** These constants are codes for each of those types.

  5547. **

  5548. ** Note that the SQLITE_TEXT constant was also used in SQLite version 2

  5549. ** for a completely different meaning.  Software that links against both

  5550. ** SQLite version 2 and SQLite version 3 should use SQLITE3_TEXT, not

  5551. ** SQLITE_TEXT.

  5552. */

  5553. #define SQLITE_INTEGER  1

  5554. #define SQLITE_FLOAT    2

  5555. #define SQLITE_BLOB     4

  5556. #define SQLITE_NULL     5

  5557. #ifdef SQLITE_TEXT

  5558. # undef SQLITE_TEXT

  5559. #else

  5560. # define SQLITE_TEXT     3

  5561. #endif

  5562. #define SQLITE3_TEXT     3

  5563. 

  5564. /*

  5565. ** CAPI3REF: Result Values From A Query

  5566. ** KEYWORDS: {column access functions}

  5567. ** METHOD: sqlite3_stmt

  5568. **

  5569. ** <b>Summary:</b>

  5570. ** <blockquote><table border=0 cellpadding=0 cellspacing=0>

  5571. ** <tr><td><b>sqlite3_column_blob</b><td>&rarr;<td>BLOB result

  5572. ** <tr><td><b>sqlite3_column_double</b><td>&rarr;<td>REAL result

  5573. ** <tr><td><b>sqlite3_column_int</b><td>&rarr;<td>32-bit INTEGER result

  5574. ** <tr><td><b>sqlite3_column_int64</b><td>&rarr;<td>64-bit INTEGER result

  5575. ** <tr><td><b>sqlite3_column_text</b><td>&rarr;<td>UTF-8 TEXT result

  5576. ** <tr><td><b>sqlite3_column_text16</b><td>&rarr;<td>UTF-16 TEXT result

  5577. ** <tr><td><b>sqlite3_column_value</b><td>&rarr;<td>The result as an 

  5578. ** [sqlite3_value|unprotected sqlite3_value] object.

  5579. ** <tr><td>&nbsp;<td>&nbsp;<td>&nbsp;

  5580. ** <tr><td><b>sqlite3_column_bytes</b><td>&rarr;<td>Size of a BLOB

  5581. ** or a UTF-8 TEXT result in bytes

  5582. ** <tr><td><b>sqlite3_column_bytes16&nbsp;&nbsp;</b>

  5583. ** <td>&rarr;&nbsp;&nbsp;<td>Size of UTF-16

  5584. ** TEXT in bytes

  5585. ** <tr><td><b>sqlite3_column_type</b><td>&rarr;<td>Default

  5586. ** datatype of the result

  5587. ** </table></blockquote>

  5588. **

  5589. ** <b>Details:</b>

  5590. **

  5591. ** ^These routines return information about a single column of the current

  5592. ** result row of a query.  ^In every case the first argument is a pointer

  5593. ** to the [prepared statement] that is being evaluated (the [sqlite3_stmt*]

  5594. ** that was returned from [sqlite3_prepare_v2()] or one of its variants)

  5595. ** and the second argument is the index of the column for which information

  5596. ** should be returned. ^The leftmost column of the result set has the index 0.

  5597. ** ^The number of columns in the result can be determined using

  5598. ** [sqlite3_column_count()].

  5599. **

  5600. ** If the SQL statement does not currently point to a valid row, or if the

  5601. ** column index is out of range, the result is undefined.

  5602. ** These routines may only be called when the most recent call to

  5603. ** [sqlite3_step()] has returned [SQLITE_ROW] and neither

  5604. ** [sqlite3_reset()] nor [sqlite3_finalize()] have been called subsequently.

  5605. ** If any of these routines are called after [sqlite3_reset()] or

  5606. ** [sqlite3_finalize()] or after [sqlite3_step()] has returned

  5607. ** something other than [SQLITE_ROW], the results are undefined.

  5608. ** If [sqlite3_step()] or [sqlite3_reset()] or [sqlite3_finalize()]

  5609. ** are called from a different thread while any of these routines

  5610. ** are pending, then the results are undefined.

  5611. **

  5612. ** The first six interfaces (_blob, _double, _int, _int64, _text, and _text16)

  5613. ** each return the value of a result column in a specific data format.  If

  5614. ** the result column is not initially in the requested format (for example,

  5615. ** if the query returns an integer but the sqlite3_column_text() interface

  5616. ** is used to extract the value) then an automatic type conversion is performed.

  5617. **

  5618. ** ^The sqlite3_column_type() routine returns the

  5619. ** [SQLITE_INTEGER | datatype code] for the initial data type

  5620. ** of the result column.  ^The returned value is one of [SQLITE_INTEGER],

  5621. ** [SQLITE_FLOAT], [SQLITE_TEXT], [SQLITE_BLOB], or [SQLITE_NULL].

  5622. ** The return value of sqlite3_column_type() can be used to decide which

  5623. ** of the first six interface should be used to extract the column value.

  5624. ** The value returned by sqlite3_column_type() is only meaningful if no

  5625. ** automatic type conversions have occurred for the value in question.  

  5626. ** After a type conversion, the result of calling sqlite3_column_type()

  5627. ** is undefined, though harmless.  Future

  5628. ** versions of SQLite may change the behavior of sqlite3_column_type()

  5629. ** following a type conversion.

  5630. **

  5631. ** If the result is a BLOB or a TEXT string, then the sqlite3_column_bytes()

  5632. ** or sqlite3_column_bytes16() interfaces can be used to determine the size

  5633. ** of that BLOB or string.

  5634. **

  5635. ** ^If the result is a BLOB or UTF-8 string then the sqlite3_column_bytes()

  5636. ** routine returns the number of bytes in that BLOB or string.

  5637. ** ^If the result is a UTF-16 string, then sqlite3_column_bytes() converts

  5638. ** the string to UTF-8 and then returns the number of bytes.

  5639. ** ^If the result is a numeric value then sqlite3_column_bytes() uses

  5640. ** [sqlite3_snprintf()] to convert that value to a UTF-8 string and returns

  5641. ** the number of bytes in that string.

  5642. ** ^If the result is NULL, then sqlite3_column_bytes() returns zero.

  5643. **

  5644. ** ^If the result is a BLOB or UTF-16 string then the sqlite3_column_bytes16()

  5645. ** routine returns the number of bytes in that BLOB or string.

  5646. ** ^If the result is a UTF-8 string, then sqlite3_column_bytes16() converts

  5647. ** the string to UTF-16 and then returns the number of bytes.

  5648. ** ^If the result is a numeric value then sqlite3_column_bytes16() uses

  5649. ** [sqlite3_snprintf()] to convert that value to a UTF-16 string and returns

  5650. ** the number of bytes in that string.

  5651. ** ^If the result is NULL, then sqlite3_column_bytes16() returns zero.

  5652. **

  5653. ** ^The values returned by [sqlite3_column_bytes()] and 

  5654. ** [sqlite3_column_bytes16()] do not include the zero terminators at the end

  5655. ** of the string.  ^For clarity: the values returned by

  5656. ** [sqlite3_column_bytes()] and [sqlite3_column_bytes16()] are the number of

  5657. ** bytes in the string, not the number of characters.

  5658. **

  5659. ** ^Strings returned by sqlite3_column_text() and sqlite3_column_text16(),

  5660. ** even empty strings, are always zero-terminated.  ^The return

  5661. ** value from sqlite3_column_blob() for a zero-length BLOB is a NULL pointer.

  5662. **

  5663. ** <b>Warning:</b> ^The object returned by [sqlite3_column_value()] is an

  5664. ** [unprotected sqlite3_value] object.  In a multithreaded environment,

  5665. ** an unprotected sqlite3_value object may only be used safely with

  5666. ** [sqlite3_bind_value()] and [sqlite3_result_value()].

  5667. ** If the [unprotected sqlite3_value] object returned by

  5668. ** [sqlite3_column_value()] is used in any other way, including calls

  5669. ** to routines like [sqlite3_value_int()], [sqlite3_value_text()],

  5670. ** or [sqlite3_value_bytes()], the behavior is not threadsafe.

  5671. ** Hence, the sqlite3_column_value() interface

  5672. ** is normally only useful within the implementation of 

  5673. ** [application-defined SQL functions] or [virtual tables], not within

  5674. ** top-level application code.

  5675. **

  5676. ** The these routines may attempt to convert the datatype of the result.

  5677. ** ^For example, if the internal representation is FLOAT and a text result

  5678. ** is requested, [sqlite3_snprintf()] is used internally to perform the

  5679. ** conversion automatically.  ^(The following table details the conversions

  5680. ** that are applied:

  5681. **

  5682. ** <blockquote>

  5683. ** <table border="1">

  5684. ** <tr><th> Internal<br>Type <th> Requested<br>Type <th>  Conversion

  5685. **

  5686. ** <tr><td>  NULL    <td> INTEGER   <td> Result is 0

  5687. ** <tr><td>  NULL    <td>  FLOAT    <td> Result is 0.0

  5688. ** <tr><td>  NULL    <td>   TEXT    <td> Result is a NULL pointer

  5689. ** <tr><td>  NULL    <td>   BLOB    <td> Result is a NULL pointer

  5690. ** <tr><td> INTEGER  <td>  FLOAT    <td> Convert from integer to float

  5691. ** <tr><td> INTEGER  <td>   TEXT    <td> ASCII rendering of the integer

  5692. ** <tr><td> INTEGER  <td>   BLOB    <td> Same as INTEGER->TEXT

  5693. ** <tr><td>  FLOAT   <td> INTEGER   <td> [CAST] to INTEGER

  5694. ** <tr><td>  FLOAT   <td>   TEXT    <td> ASCII rendering of the float

  5695. ** <tr><td>  FLOAT   <td>   BLOB    <td> [CAST] to BLOB

  5696. ** <tr><td>  TEXT    <td> INTEGER   <td> [CAST] to INTEGER

  5697. ** <tr><td>  TEXT    <td>  FLOAT    <td> [CAST] to REAL

  5698. ** <tr><td>  TEXT    <td>   BLOB    <td> No change

  5699. ** <tr><td>  BLOB    <td> INTEGER   <td> [CAST] to INTEGER

  5700. ** <tr><td>  BLOB    <td>  FLOAT    <td> [CAST] to REAL

  5701. ** <tr><td>  BLOB    <td>   TEXT    <td> Add a zero terminator if needed

  5702. ** </table>

  5703. ** </blockquote>)^

  5704. **

  5705. ** Note that when type conversions occur, pointers returned by prior

  5706. ** calls to sqlite3_column_blob(), sqlite3_column_text(), and/or

  5707. ** sqlite3_column_text16() may be invalidated.

  5708. ** Type conversions and pointer invalidations might occur

  5709. ** in the following cases:

  5710. **

  5711. ** <ul>

  5712. ** <li> The initial content is a BLOB and sqlite3_column_text() or

  5713. **      sqlite3_column_text16() is called.  A zero-terminator might

  5714. **      need to be added to the string.</li>

  5715. ** <li> The initial content is UTF-8 text and sqlite3_column_bytes16() or

  5716. **      sqlite3_column_text16() is called.  The content must be converted

  5717. **      to UTF-16.</li>

  5718. ** <li> The initial content is UTF-16 text and sqlite3_column_bytes() or

  5719. **      sqlite3_column_text() is called.  The content must be converted

  5720. **      to UTF-8.</li>

  5721. ** </ul>

  5722. **

  5723. ** ^Conversions between UTF-16be and UTF-16le are always done in place and do

  5724. ** not invalidate a prior pointer, though of course the content of the buffer

  5725. ** that the prior pointer references will have been modified.  Other kinds

  5726. ** of conversion are done in place when it is possible, but sometimes they

  5727. ** are not possible and in those cases prior pointers are invalidated.

  5728. **

  5729. ** The safest policy is to invoke these routines

  5730. ** in one of the following ways:

  5731. **

  5732. ** <ul>

  5733. **  <li>sqlite3_column_text() followed by sqlite3_column_bytes()</li>

  5734. **  <li>sqlite3_column_blob() followed by sqlite3_column_bytes()</li>

  5735. **  <li>sqlite3_column_text16() followed by sqlite3_column_bytes16()</li>

  5736. ** </ul>

  5737. **

  5738. ** In other words, you should call sqlite3_column_text(),

  5739. ** sqlite3_column_blob(), or sqlite3_column_text16() first to force the result

  5740. ** into the desired format, then invoke sqlite3_column_bytes() or

  5741. ** sqlite3_column_bytes16() to find the size of the result.  Do not mix calls

  5742. ** to sqlite3_column_text() or sqlite3_column_blob() with calls to

  5743. ** sqlite3_column_bytes16(), and do not mix calls to sqlite3_column_text16()

  5744. ** with calls to sqlite3_column_bytes().

  5745. **

  5746. ** ^The pointers returned are valid until a type conversion occurs as

  5747. ** described above, or until [sqlite3_step()] or [sqlite3_reset()] or

  5748. ** [sqlite3_finalize()] is called.  ^The memory space used to hold strings

  5749. ** and BLOBs is freed automatically.  Do not pass the pointers returned

  5750. ** from [sqlite3_column_blob()], [sqlite3_column_text()], etc. into

  5751. ** [sqlite3_free()].

  5752. **

  5753. ** As long as the input parameters are correct, these routines will only

  5754. ** fail if an out-of-memory error occurs during a format conversion.

  5755. ** Only the following subset of interfaces are subject to out-of-memory

  5756. ** errors:

  5757. **

  5758. ** <ul>

  5759. ** <li> sqlite3_column_blob()

  5760. ** <li> sqlite3_column_text()

  5761. ** <li> sqlite3_column_text16()

  5762. ** <li> sqlite3_column_bytes()

  5763. ** <li> sqlite3_column_bytes16()

  5764. ** </ul>

  5765. **

  5766. ** If an out-of-memory error occurs, then the return value from these

  5767. ** routines is the same as if the column had contained an SQL NULL value.

  5768. ** Valid SQL NULL returns can be distinguished from out-of-memory errors

  5769. ** by invoking the [sqlite3_errcode()] immediately after the suspect

  5770. ** return value is obtained and before any

  5771. ** other SQLite interface is called on the same [database connection].

  5772. */

  5773. SQLITE_API const void *sqlite3_column_blob(sqlite3_stmt*, int iCol);

  5774. SQLITE_API double sqlite3_column_double(sqlite3_stmt*, int iCol);

  5775. SQLITE_API int sqlite3_column_int(sqlite3_stmt*, int iCol);

  5776. SQLITE_API sqlite3_int64 sqlite3_column_int64(sqlite3_stmt*, int iCol);

  5777. SQLITE_API const unsigned char *sqlite3_column_text(sqlite3_stmt*, int iCol);

  5778. SQLITE_API const void *sqlite3_column_text16(sqlite3_stmt*, int iCol);

  5779. SQLITE_API sqlite3_value *sqlite3_column_value(sqlite3_stmt*, int iCol);

  5780. SQLITE_API int sqlite3_column_bytes(sqlite3_stmt*, int iCol);

  5781. SQLITE_API int sqlite3_column_bytes16(sqlite3_stmt*, int iCol);

  5782. SQLITE_API int sqlite3_column_type(sqlite3_stmt*, int iCol);

  5783. 

  5784. /*

  5785. ** CAPI3REF: Destroy A Prepared Statement Object

  5786. ** DESTRUCTOR: sqlite3_stmt

  5787. **

  5788. ** ^The sqlite3_finalize() function is called to delete a [prepared statement].

  5789. ** ^If the most recent evaluation of the statement encountered no errors

  5790. ** or if the statement is never been evaluated, then sqlite3_finalize() returns

  5791. ** SQLITE_OK.  ^If the most recent evaluation of statement S failed, then

  5792. ** sqlite3_finalize(S) returns the appropriate [error code] or

  5793. ** [extended error code].

  5794. **

  5795. ** ^The sqlite3_finalize(S) routine can be called at any point during

  5796. ** the life cycle of [prepared statement] S:

  5797. ** before statement S is ever evaluated, after

  5798. ** one or more calls to [sqlite3_reset()], or after any call

  5799. ** to [sqlite3_step()] regardless of whether or not the statement has

  5800. ** completed execution.

  5801. **

  5802. ** ^Invoking sqlite3_finalize() on a NULL pointer is a harmless no-op.

  5803. **

  5804. ** The application must finalize every [prepared statement] in order to avoid

  5805. ** resource leaks.  It is a grievous error for the application to try to use

  5806. ** a prepared statement after it has been finalized.  Any use of a prepared

  5807. ** statement after it has been finalized can result in undefined and

  5808. ** undesirable behavior such as segfaults and heap corruption.

  5809. */

  5810. SQLITE_API int sqlite3_finalize(sqlite3_stmt *pStmt);

  5811. 

  5812. /*

  5813. ** CAPI3REF: Reset A Prepared Statement Object

  5814. ** METHOD: sqlite3_stmt

  5815. **

  5816. ** The sqlite3_reset() function is called to reset a [prepared statement]

  5817. ** object back to its initial state, ready to be re-executed.

  5818. ** ^Any SQL statement variables that had values bound to them using

  5819. ** the [sqlite3_bind_blob | sqlite3_bind_*() API] retain their values.

  5820. ** Use [sqlite3_clear_bindings()] to reset the bindings.

  5821. **

  5822. ** ^The [sqlite3_reset(S)] interface resets the [prepared statement] S

  5823. ** back to the beginning of its program.

  5824. **

  5825. ** ^If the most recent call to [sqlite3_step(S)] for the

  5826. ** [prepared statement] S returned [SQLITE_ROW] or [SQLITE_DONE],

  5827. ** or if [sqlite3_step(S)] has never before been called on S,

  5828. ** then [sqlite3_reset(S)] returns [SQLITE_OK].

  5829. **

  5830. ** ^If the most recent call to [sqlite3_step(S)] for the

  5831. ** [prepared statement] S indicated an error, then

  5832. ** [sqlite3_reset(S)] returns an appropriate [error code].

  5833. **

  5834. ** ^The [sqlite3_reset(S)] interface does not change the values

  5835. ** of any [sqlite3_bind_blob|bindings] on the [prepared statement] S.

  5836. */

  5837. SQLITE_API int sqlite3_reset(sqlite3_stmt *pStmt);

  5838. 

  5839. /*

  5840. ** CAPI3REF: Create Or Redefine SQL Functions

  5841. ** KEYWORDS: {function creation routines}

  5842. ** KEYWORDS: {application-defined SQL function}

  5843. ** KEYWORDS: {application-defined SQL functions}

  5844. ** METHOD: sqlite3

  5845. **

  5846. ** ^These functions (collectively known as "function creation routines")

  5847. ** are used to add SQL functions or aggregates or to redefine the behavior

  5848. ** of existing SQL functions or aggregates. The only differences between

  5849. ** the three "sqlite3_create_function*" routines are the text encoding 

  5850. ** expected for the second parameter (the name of the function being 

  5851. ** created) and the presence or absence of a destructor callback for

  5852. ** the application data pointer. Function sqlite3_create_window_function()

  5853. ** is similar, but allows the user to supply the extra callback functions

  5854. ** needed by [aggregate window functions].

  5855. **

  5856. ** ^The first parameter is the [database connection] to which the SQL

  5857. ** function is to be added.  ^If an application uses more than one database

  5858. ** connection then application-defined SQL functions must be added

  5859. ** to each database connection separately.

  5860. **

  5861. ** ^The second parameter is the name of the SQL function to be created or

  5862. ** redefined.  ^The length of the name is limited to 255 bytes in a UTF-8

  5863. ** representation, exclusive of the zero-terminator.  ^Note that the name

  5864. ** length limit is in UTF-8 bytes, not characters nor UTF-16 bytes.  

  5865. ** ^Any attempt to create a function with a longer name

  5866. ** will result in [SQLITE_MISUSE] being returned.

  5867. **

  5868. ** ^The third parameter (nArg)

  5869. ** is the number of arguments that the SQL function or

  5870. ** aggregate takes. ^If this parameter is -1, then the SQL function or

  5871. ** aggregate may take any number of arguments between 0 and the limit

  5872. ** set by [sqlite3_limit]([SQLITE_LIMIT_FUNCTION_ARG]).  If the third

  5873. ** parameter is less than -1 or greater than 127 then the behavior is

  5874. ** undefined.

  5875. **

  5876. ** ^The fourth parameter, eTextRep, specifies what

  5877. ** [SQLITE_UTF8 | text encoding] this SQL function prefers for

  5878. ** its parameters.  The application should set this parameter to

  5879. ** [SQLITE_UTF16LE] if the function implementation invokes 

  5880. ** [sqlite3_value_text16le()] on an input, or [SQLITE_UTF16BE] if the

  5881. ** implementation invokes [sqlite3_value_text16be()] on an input, or

  5882. ** [SQLITE_UTF16] if [sqlite3_value_text16()] is used, or [SQLITE_UTF8]

  5883. ** otherwise.  ^The same SQL function may be registered multiple times using

  5884. ** different preferred text encodings, with different implementations for

  5885. ** each encoding.

  5886. ** ^When multiple implementations of the same function are available, SQLite

  5887. ** will pick the one that involves the least amount of data conversion.

  5888. **

  5889. ** ^The fourth parameter may optionally be ORed with [SQLITE_DETERMINISTIC]

  5890. ** to signal that the function will always return the same result given

  5891. ** the same inputs within a single SQL statement.  Most SQL functions are

  5892. ** deterministic.  The built-in [random()] SQL function is an example of a

  5893. ** function that is not deterministic.  The SQLite query planner is able to

  5894. ** perform additional optimizations on deterministic functions, so use

  5895. ** of the [SQLITE_DETERMINISTIC] flag is recommended where possible.

  5896. **

  5897. ** ^(The fifth parameter is an arbitrary pointer.  The implementation of the

  5898. ** function can gain access to this pointer using [sqlite3_user_data()].)^

  5899. **

  5900. ** ^The sixth, seventh and eighth parameters passed to the three

  5901. ** "sqlite3_create_function*" functions, xFunc, xStep and xFinal, are

  5902. ** pointers to C-language functions that implement the SQL function or

  5903. ** aggregate. ^A scalar SQL function requires an implementation of the xFunc

  5904. ** callback only; NULL pointers must be passed as the xStep and xFinal

  5905. ** parameters. ^An aggregate SQL function requires an implementation of xStep

  5906. ** and xFinal and NULL pointer must be passed for xFunc. ^To delete an existing

  5907. ** SQL function or aggregate, pass NULL pointers for all three function

  5908. ** callbacks.

  5909. **

  5910. ** ^The sixth, seventh, eighth and ninth parameters (xStep, xFinal, xValue 

  5911. ** and xInverse) passed to sqlite3_create_window_function are pointers to

  5912. ** C-language callbacks that implement the new function. xStep and xFinal

  5913. ** must both be non-NULL. xValue and xInverse may either both be NULL, in

  5914. ** which case a regular aggregate function is created, or must both be 

  5915. ** non-NULL, in which case the new function may be used as either an aggregate

  5916. ** or aggregate window function. More details regarding the implementation

  5917. ** of aggregate window functions are 

  5918. ** [user-defined window functions|available here].

  5919. **

  5920. ** ^(If the final parameter to sqlite3_create_function_v2() or

  5921. ** sqlite3_create_window_function() is not NULL, then it is destructor for

  5922. ** the application data pointer. The destructor is invoked when the function 

  5923. ** is deleted, either by being overloaded or when the database connection 

  5924. ** closes.)^ ^The destructor is also invoked if the call to 

  5925. ** sqlite3_create_function_v2() fails.  ^When the destructor callback is

  5926. ** invoked, it is passed a single argument which is a copy of the application

  5927. ** data pointer which was the fifth parameter to sqlite3_create_function_v2().

  5928. **

  5929. ** ^It is permitted to register multiple implementations of the same

  5930. ** functions with the same name but with either differing numbers of

  5931. ** arguments or differing preferred text encodings.  ^SQLite will use

  5932. ** the implementation that most closely matches the way in which the

  5933. ** SQL function is used.  ^A function implementation with a non-negative

  5934. ** nArg parameter is a better match than a function implementation with

  5935. ** a negative nArg.  ^A function where the preferred text encoding

  5936. ** matches the database encoding is a better

  5937. ** match than a function where the encoding is different.  

  5938. ** ^A function where the encoding difference is between UTF16le and UTF16be

  5939. ** is a closer match than a function where the encoding difference is

  5940. ** between UTF8 and UTF16.

  5941. **

  5942. ** ^Built-in functions may be overloaded by new application-defined functions.

  5943. **

  5944. ** ^An application-defined function is permitted to call other

  5945. ** SQLite interfaces.  However, such calls must not

  5946. ** close the database connection nor finalize or reset the prepared

  5947. ** statement in which the function is running.

  5948. */

  5949. SQLITE_API int sqlite3_create_function(

  5950.   sqlite3 *db,

  5951.   const char *zFunctionName,

  5952.   int nArg,

  5953.   int eTextRep,

  5954.   void *pApp,

  5955.   void (*xFunc)(sqlite3_context*,int,sqlite3_value**),

  5956.   void (*xStep)(sqlite3_context*,int,sqlite3_value**),

  5957.   void (*xFinal)(sqlite3_context*)

  5958. );

  5959. SQLITE_API int sqlite3_create_function16(

  5960.   sqlite3 *db,

  5961.   const void *zFunctionName,

  5962.   int nArg,

  5963.   int eTextRep,

  5964.   void *pApp,

  5965.   void (*xFunc)(sqlite3_context*,int,sqlite3_value**),

  5966.   void (*xStep)(sqlite3_context*,int,sqlite3_value**),

  5967.   void (*xFinal)(sqlite3_context*)

  5968. );

  5969. SQLITE_API int sqlite3_create_function_v2(

  5970.   sqlite3 *db,

  5971.   const char *zFunctionName,

  5972.   int nArg,

  5973.   int eTextRep,

  5974.   void *pApp,

  5975.   void (*xFunc)(sqlite3_context*,int,sqlite3_value**),

  5976.   void (*xStep)(sqlite3_context*,int,sqlite3_value**),

  5977.   void (*xFinal)(sqlite3_context*),

  5978.   void(*xDestroy)(void*)

  5979. );

  5980. SQLITE_API int sqlite3_create_window_function(

  5981.   sqlite3 *db,

  5982.   const char *zFunctionName,

  5983.   int nArg,

  5984.   int eTextRep,

  5985.   void *pApp,

  5986.   void (*xStep)(sqlite3_context*,int,sqlite3_value**),

  5987.   void (*xFinal)(sqlite3_context*),

  5988.   void (*xValue)(sqlite3_context*),

  5989.   void (*xInverse)(sqlite3_context*,int,sqlite3_value**),

  5990.   void(*xDestroy)(void*)

  5991. );

  5992. 

  5993. /*

  5994. ** CAPI3REF: Text Encodings

  5995. **

  5996. ** These constant define integer codes that represent the various

  5997. ** text encodings supported by SQLite.

  5998. */

  5999. #define SQLITE_UTF8           1    /* IMP: R-37514-35566 */

  6000. #define SQLITE_UTF16LE        2    /* IMP: R-03371-37637 */

  6001. #define SQLITE_UTF16BE        3    /* IMP: R-51971-34154 */

  6002. #define SQLITE_UTF16          4    /* Use native byte order */

  6003. #define SQLITE_ANY            5    /* Deprecated */

  6004. #define SQLITE_UTF16_ALIGNED  8    /* sqlite3_create_collation only */

  6005. 

  6006. /*

  6007. ** CAPI3REF: Function Flags

  6008. **

  6009. ** These constants may be ORed together with the 

  6010. ** [SQLITE_UTF8 | preferred text encoding] as the fourth argument

  6011. ** to [sqlite3_create_function()], [sqlite3_create_function16()], or

  6012. ** [sqlite3_create_function_v2()].

  6013. */

  6014. #define SQLITE_DETERMINISTIC    0x800

  6015. 

  6016. /*

  6017. ** CAPI3REF: Deprecated Functions

  6018. ** DEPRECATED

  6019. **

  6020. ** These functions are [deprecated].  In order to maintain

  6021. ** backwards compatibility with older code, these functions continue 

  6022. ** to be supported.  However, new applications should avoid

  6023. ** the use of these functions.  To encourage programmers to avoid

  6024. ** these functions, we will not explain what they do.

  6025. */

  6026. #ifndef SQLITE_OMIT_DEPRECATED

  6027. SQLITE_API SQLITE_DEPRECATED int sqlite3_aggregate_count(sqlite3_context*);

  6028. SQLITE_API SQLITE_DEPRECATED int sqlite3_expired(sqlite3_stmt*);

  6029. SQLITE_API SQLITE_DEPRECATED int sqlite3_transfer_bindings(sqlite3_stmt*, sqlite3_stmt*);

  6030. SQLITE_API SQLITE_DEPRECATED int sqlite3_global_recover(void);

  6031. SQLITE_API SQLITE_DEPRECATED void sqlite3_thread_cleanup(void);

  6032. SQLITE_API SQLITE_DEPRECATED int sqlite3_memory_alarm(void(*)(void*,sqlite3_int64,int),

  6033.                       void*,sqlite3_int64);

  6034. #endif

  6035. 

  6036. /*

  6037. ** CAPI3REF: Obtaining SQL Values

  6038. ** METHOD: sqlite3_value

  6039. **

  6040. ** <b>Summary:</b>

  6041. ** <blockquote><table border=0 cellpadding=0 cellspacing=0>

  6042. ** <tr><td><b>sqlite3_value_blob</b><td>&rarr;<td>BLOB value

  6043. ** <tr><td><b>sqlite3_value_double</b><td>&rarr;<td>REAL value

  6044. ** <tr><td><b>sqlite3_value_int</b><td>&rarr;<td>32-bit INTEGER value

  6045. ** <tr><td><b>sqlite3_value_int64</b><td>&rarr;<td>64-bit INTEGER value

  6046. ** <tr><td><b>sqlite3_value_pointer</b><td>&rarr;<td>Pointer value

  6047. ** <tr><td><b>sqlite3_value_text</b><td>&rarr;<td>UTF-8 TEXT value

  6048. ** <tr><td><b>sqlite3_value_text16</b><td>&rarr;<td>UTF-16 TEXT value in

  6049. ** the native byteorder

  6050. ** <tr><td><b>sqlite3_value_text16be</b><td>&rarr;<td>UTF-16be TEXT value

  6051. ** <tr><td><b>sqlite3_value_text16le</b><td>&rarr;<td>UTF-16le TEXT value

  6052. ** <tr><td>&nbsp;<td>&nbsp;<td>&nbsp;

  6053. ** <tr><td><b>sqlite3_value_bytes</b><td>&rarr;<td>Size of a BLOB

  6054. ** or a UTF-8 TEXT in bytes

  6055. ** <tr><td><b>sqlite3_value_bytes16&nbsp;&nbsp;</b>

  6056. ** <td>&rarr;&nbsp;&nbsp;<td>Size of UTF-16

  6057. ** TEXT in bytes

  6058. ** <tr><td><b>sqlite3_value_type</b><td>&rarr;<td>Default

  6059. ** datatype of the value

  6060. ** <tr><td><b>sqlite3_value_numeric_type&nbsp;&nbsp;</b>

  6061. ** <td>&rarr;&nbsp;&nbsp;<td>Best numeric datatype of the value

  6062. ** <tr><td><b>sqlite3_value_nochange&nbsp;&nbsp;</b>

  6063. ** <td>&rarr;&nbsp;&nbsp;<td>True if the column is unchanged in an UPDATE

  6064. ** against a virtual table.

  6065. ** <tr><td><b>sqlite3_value_frombind&nbsp;&nbsp;</b>

  6066. ** <td>&rarr;&nbsp;&nbsp;<td>True if value originated from a [bound parameter]

  6067. ** </table></blockquote>

  6068. **

  6069. ** <b>Details:</b>

  6070. **

  6071. ** These routines extract type, size, and content information from

  6072. ** [protected sqlite3_value] objects.  Protected sqlite3_value objects

  6073. ** are used to pass parameter information into implementation of

  6074. ** [application-defined SQL functions] and [virtual tables].

  6075. **

  6076. ** These routines work only with [protected sqlite3_value] objects.

  6077. ** Any attempt to use these routines on an [unprotected sqlite3_value]

  6078. ** is not threadsafe.

  6079. **

  6080. ** ^These routines work just like the corresponding [column access functions]

  6081. ** except that these routines take a single [protected sqlite3_value] object

  6082. ** pointer instead of a [sqlite3_stmt*] pointer and an integer column number.

  6083. **

  6084. ** ^The sqlite3_value_text16() interface extracts a UTF-16 string

  6085. ** in the native byte-order of the host machine.  ^The

  6086. ** sqlite3_value_text16be() and sqlite3_value_text16le() interfaces

  6087. ** extract UTF-16 strings as big-endian and little-endian respectively.

  6088. **

  6089. ** ^If [sqlite3_value] object V was initialized 

  6090. ** using [sqlite3_bind_pointer(S,I,P,X,D)] or [sqlite3_result_pointer(C,P,X,D)]

  6091. ** and if X and Y are strings that compare equal according to strcmp(X,Y),

  6092. ** then sqlite3_value_pointer(V,Y) will return the pointer P.  ^Otherwise,

  6093. ** sqlite3_value_pointer(V,Y) returns a NULL. The sqlite3_bind_pointer() 

  6094. ** routine is part of the [pointer passing interface] added for SQLite 3.20.0.

  6095. **

  6096. ** ^(The sqlite3_value_type(V) interface returns the

  6097. ** [SQLITE_INTEGER | datatype code] for the initial datatype of the

  6098. ** [sqlite3_value] object V. The returned value is one of [SQLITE_INTEGER],

  6099. ** [SQLITE_FLOAT], [SQLITE_TEXT], [SQLITE_BLOB], or [SQLITE_NULL].)^

  6100. ** Other interfaces might change the datatype for an sqlite3_value object.

  6101. ** For example, if the datatype is initially SQLITE_INTEGER and

  6102. ** sqlite3_value_text(V) is called to extract a text value for that

  6103. ** integer, then subsequent calls to sqlite3_value_type(V) might return

  6104. ** SQLITE_TEXT.  Whether or not a persistent internal datatype conversion

  6105. ** occurs is undefined and may change from one release of SQLite to the next.

  6106. **

  6107. ** ^(The sqlite3_value_numeric_type() interface attempts to apply

  6108. ** numeric affinity to the value.  This means that an attempt is

  6109. ** made to convert the value to an integer or floating point.  If

  6110. ** such a conversion is possible without loss of information (in other

  6111. ** words, if the value is a string that looks like a number)

  6112. ** then the conversion is performed.  Otherwise no conversion occurs.

  6113. ** The [SQLITE_INTEGER | datatype] after conversion is returned.)^

  6114. **

  6115. ** ^Within the [xUpdate] method of a [virtual table], the

  6116. ** sqlite3_value_nochange(X) interface returns true if and only if

  6117. ** the column corresponding to X is unchanged by the UPDATE operation

  6118. ** that the xUpdate method call was invoked to implement and if

  6119. ** and the prior [xColumn] method call that was invoked to extracted

  6120. ** the value for that column returned without setting a result (probably

  6121. ** because it queried [sqlite3_vtab_nochange()] and found that the column

  6122. ** was unchanging).  ^Within an [xUpdate] method, any value for which

  6123. ** sqlite3_value_nochange(X) is true will in all other respects appear

  6124. ** to be a NULL value.  If sqlite3_value_nochange(X) is invoked anywhere other

  6125. ** than within an [xUpdate] method call for an UPDATE statement, then

  6126. ** the return value is arbitrary and meaningless.

  6127. **

  6128. ** ^The sqlite3_value_frombind(X) interface returns non-zero if the

  6129. ** value X originated from one of the [sqlite3_bind_int|sqlite3_bind()]

  6130. ** interfaces.  ^If X comes from an SQL literal value, or a table column,

  6131. ** and expression, then sqlite3_value_frombind(X) returns zero.

  6132. **

  6133. ** Please pay particular attention to the fact that the pointer returned

  6134. ** from [sqlite3_value_blob()], [sqlite3_value_text()], or

  6135. ** [sqlite3_value_text16()] can be invalidated by a subsequent call to

  6136. ** [sqlite3_value_bytes()], [sqlite3_value_bytes16()], [sqlite3_value_text()],

  6137. ** or [sqlite3_value_text16()].

  6138. **

  6139. ** These routines must be called from the same thread as

  6140. ** the SQL function that supplied the [sqlite3_value*] parameters.

  6141. **

  6142. ** As long as the input parameter is correct, these routines can only

  6143. ** fail if an out-of-memory error occurs during a format conversion.

  6144. ** Only the following subset of interfaces are subject to out-of-memory

  6145. ** errors:

  6146. **

  6147. ** <ul>

  6148. ** <li> sqlite3_value_blob()

  6149. ** <li> sqlite3_value_text()

  6150. ** <li> sqlite3_value_text16()

  6151. ** <li> sqlite3_value_text16le()

  6152. ** <li> sqlite3_value_text16be()

  6153. ** <li> sqlite3_value_bytes()

  6154. ** <li> sqlite3_value_bytes16()

  6155. ** </ul>

  6156. **

  6157. ** If an out-of-memory error occurs, then the return value from these

  6158. ** routines is the same as if the column had contained an SQL NULL value.

  6159. ** Valid SQL NULL returns can be distinguished from out-of-memory errors

  6160. ** by invoking the [sqlite3_errcode()] immediately after the suspect

  6161. ** return value is obtained and before any

  6162. ** other SQLite interface is called on the same [database connection].

  6163. */

  6164. SQLITE_API const void *sqlite3_value_blob(sqlite3_value*);

  6165. SQLITE_API double sqlite3_value_double(sqlite3_value*);

  6166. SQLITE_API int sqlite3_value_int(sqlite3_value*);

  6167. SQLITE_API sqlite3_int64 sqlite3_value_int64(sqlite3_value*);

  6168. SQLITE_API void *sqlite3_value_pointer(sqlite3_value*, const char*);

  6169. SQLITE_API const unsigned char *sqlite3_value_text(sqlite3_value*);

  6170. SQLITE_API const void *sqlite3_value_text16(sqlite3_value*);

  6171. SQLITE_API const void *sqlite3_value_text16le(sqlite3_value*);

  6172. SQLITE_API const void *sqlite3_value_text16be(sqlite3_value*);

  6173. SQLITE_API int sqlite3_value_bytes(sqlite3_value*);

  6174. SQLITE_API int sqlite3_value_bytes16(sqlite3_value*);

  6175. SQLITE_API int sqlite3_value_type(sqlite3_value*);

  6176. SQLITE_API int sqlite3_value_numeric_type(sqlite3_value*);

  6177. SQLITE_API int sqlite3_value_nochange(sqlite3_value*);

  6178. SQLITE_API int sqlite3_value_frombind(sqlite3_value*);

  6179. 

  6180. /*

  6181. ** CAPI3REF: Finding The Subtype Of SQL Values

  6182. ** METHOD: sqlite3_value

  6183. **

  6184. ** The sqlite3_value_subtype(V) function returns the subtype for

  6185. ** an [application-defined SQL function] argument V.  The subtype

  6186. ** information can be used to pass a limited amount of context from

  6187. ** one SQL function to another.  Use the [sqlite3_result_subtype()]

  6188. ** routine to set the subtype for the return value of an SQL function.

  6189. */

  6190. SQLITE_API unsigned int sqlite3_value_subtype(sqlite3_value*);

  6191. 

  6192. /*

  6193. ** CAPI3REF: Copy And Free SQL Values

  6194. ** METHOD: sqlite3_value

  6195. **

  6196. ** ^The sqlite3_value_dup(V) interface makes a copy of the [sqlite3_value]

  6197. ** object D and returns a pointer to that copy.  ^The [sqlite3_value] returned

  6198. ** is a [protected sqlite3_value] object even if the input is not.

  6199. ** ^The sqlite3_value_dup(V) interface returns NULL if V is NULL or if a

  6200. ** memory allocation fails.

  6201. **

  6202. ** ^The sqlite3_value_free(V) interface frees an [sqlite3_value] object

  6203. ** previously obtained from [sqlite3_value_dup()].  ^If V is a NULL pointer

  6204. ** then sqlite3_value_free(V) is a harmless no-op.

  6205. */

  6206. SQLITE_API sqlite3_value *sqlite3_value_dup(const sqlite3_value*);

  6207. SQLITE_API void sqlite3_value_free(sqlite3_value*);

  6208. 

  6209. /*

  6210. ** CAPI3REF: Obtain Aggregate Function Context

  6211. ** METHOD: sqlite3_context

  6212. **

  6213. ** Implementations of aggregate SQL functions use this

  6214. ** routine to allocate memory for storing their state.

  6215. **

  6216. ** ^The first time the sqlite3_aggregate_context(C,N) routine is called 

  6217. ** for a particular aggregate function, SQLite

  6218. ** allocates N of memory, zeroes out that memory, and returns a pointer

  6219. ** to the new memory. ^On second and subsequent calls to

  6220. ** sqlite3_aggregate_context() for the same aggregate function instance,

  6221. ** the same buffer is returned.  Sqlite3_aggregate_context() is normally

  6222. ** called once for each invocation of the xStep callback and then one

  6223. ** last time when the xFinal callback is invoked.  ^(When no rows match

  6224. ** an aggregate query, the xStep() callback of the aggregate function

  6225. ** implementation is never called and xFinal() is called exactly once.

  6226. ** In those cases, sqlite3_aggregate_context() might be called for the

  6227. ** first time from within xFinal().)^

  6228. **

  6229. ** ^The sqlite3_aggregate_context(C,N) routine returns a NULL pointer 

  6230. ** when first called if N is less than or equal to zero or if a memory

  6231. ** allocate error occurs.

  6232. **

  6233. ** ^(The amount of space allocated by sqlite3_aggregate_context(C,N) is

  6234. ** determined by the N parameter on first successful call.  Changing the

  6235. ** value of N in subsequent call to sqlite3_aggregate_context() within

  6236. ** the same aggregate function instance will not resize the memory

  6237. ** allocation.)^  Within the xFinal callback, it is customary to set

  6238. ** N=0 in calls to sqlite3_aggregate_context(C,N) so that no 

  6239. ** pointless memory allocations occur.

  6240. **

  6241. ** ^SQLite automatically frees the memory allocated by 

  6242. ** sqlite3_aggregate_context() when the aggregate query concludes.

  6243. **

  6244. ** The first parameter must be a copy of the

  6245. ** [sqlite3_context | SQL function context] that is the first parameter

  6246. ** to the xStep or xFinal callback routine that implements the aggregate

  6247. ** function.

  6248. **

  6249. ** This routine must be called from the same thread in which

  6250. ** the aggregate SQL function is running.

  6251. */

  6252. SQLITE_API void *sqlite3_aggregate_context(sqlite3_context*, int nBytes);

  6253. 

  6254. /*

  6255. ** CAPI3REF: User Data For Functions

  6256. ** METHOD: sqlite3_context

  6257. **

  6258. ** ^The sqlite3_user_data() interface returns a copy of

  6259. ** the pointer that was the pUserData parameter (the 5th parameter)

  6260. ** of the [sqlite3_create_function()]

  6261. ** and [sqlite3_create_function16()] routines that originally

  6262. ** registered the application defined function.

  6263. **

  6264. ** This routine must be called from the same thread in which

  6265. ** the application-defined function is running.

  6266. */

  6267. SQLITE_API void *sqlite3_user_data(sqlite3_context*);

  6268. 

  6269. /*

  6270. ** CAPI3REF: Database Connection For Functions

  6271. ** METHOD: sqlite3_context

  6272. **

  6273. ** ^The sqlite3_context_db_handle() interface returns a copy of

  6274. ** the pointer to the [database connection] (the 1st parameter)

  6275. ** of the [sqlite3_create_function()]

  6276. ** and [sqlite3_create_function16()] routines that originally

  6277. ** registered the application defined function.

  6278. */

  6279. SQLITE_API sqlite3 *sqlite3_context_db_handle(sqlite3_context*);

  6280. 

  6281. /*

  6282. ** CAPI3REF: Function Auxiliary Data

  6283. ** METHOD: sqlite3_context

  6284. **

  6285. ** These functions may be used by (non-aggregate) SQL functions to

  6286. ** associate metadata with argument values. If the same value is passed to

  6287. ** multiple invocations of the same SQL function during query execution, under

  6288. ** some circumstances the associated metadata may be preserved.  An example

  6289. ** of where this might be useful is in a regular-expression matching

  6290. ** function. The compiled version of the regular expression can be stored as

  6291. ** metadata associated with the pattern string.  

  6292. ** Then as long as the pattern string remains the same,

  6293. ** the compiled regular expression can be reused on multiple

  6294. ** invocations of the same function.

  6295. **

  6296. ** ^The sqlite3_get_auxdata(C,N) interface returns a pointer to the metadata

  6297. ** associated by the sqlite3_set_auxdata(C,N,P,X) function with the Nth argument

  6298. ** value to the application-defined function.  ^N is zero for the left-most

  6299. ** function argument.  ^If there is no metadata

  6300. ** associated with the function argument, the sqlite3_get_auxdata(C,N) interface

  6301. ** returns a NULL pointer.

  6302. **

  6303. ** ^The sqlite3_set_auxdata(C,N,P,X) interface saves P as metadata for the N-th

  6304. ** argument of the application-defined function.  ^Subsequent

  6305. ** calls to sqlite3_get_auxdata(C,N) return P from the most recent

  6306. ** sqlite3_set_auxdata(C,N,P,X) call if the metadata is still valid or

  6307. ** NULL if the metadata has been discarded.

  6308. ** ^After each call to sqlite3_set_auxdata(C,N,P,X) where X is not NULL,

  6309. ** SQLite will invoke the destructor function X with parameter P exactly

  6310. ** once, when the metadata is discarded.

  6311. ** SQLite is free to discard the metadata at any time, including: <ul>

  6312. ** <li> ^(when the corresponding function parameter changes)^, or

  6313. ** <li> ^(when [sqlite3_reset()] or [sqlite3_finalize()] is called for the

  6314. **      SQL statement)^, or

  6315. ** <li> ^(when sqlite3_set_auxdata() is invoked again on the same

  6316. **       parameter)^, or

  6317. ** <li> ^(during the original sqlite3_set_auxdata() call when a memory 

  6318. **      allocation error occurs.)^ </ul>

  6319. **

  6320. ** Note the last bullet in particular.  The destructor X in 

  6321. ** sqlite3_set_auxdata(C,N,P,X) might be called immediately, before the

  6322. ** sqlite3_set_auxdata() interface even returns.  Hence sqlite3_set_auxdata()

  6323. ** should be called near the end of the function implementation and the

  6324. ** function implementation should not make any use of P after

  6325. ** sqlite3_set_auxdata() has been called.

  6326. **

  6327. ** ^(In practice, metadata is preserved between function calls for

  6328. ** function parameters that are compile-time constants, including literal

  6329. ** values and [parameters] and expressions composed from the same.)^

  6330. **

  6331. ** The value of the N parameter to these interfaces should be non-negative.

  6332. ** Future enhancements may make use of negative N values to define new

  6333. ** kinds of function caching behavior.

  6334. **

  6335. ** These routines must be called from the same thread in which

  6336. ** the SQL function is running.

  6337. */

  6338. SQLITE_API void *sqlite3_get_auxdata(sqlite3_context*, int N);

  6339. SQLITE_API void sqlite3_set_auxdata(sqlite3_context*, int N, void*, void (*)(void*));

  6340. 

  6341. 

  6342. /*

  6343. ** CAPI3REF: Constants Defining Special Destructor Behavior

  6344. **

  6345. ** These are special values for the destructor that is passed in as the

  6346. ** final argument to routines like [sqlite3_result_blob()].  ^If the destructor

  6347. ** argument is SQLITE_STATIC, it means that the content pointer is constant

  6348. ** and will never change.  It does not need to be destroyed.  ^The

  6349. ** SQLITE_TRANSIENT value means that the content will likely change in

  6350. ** the near future and that SQLite should make its own private copy of

  6351. ** the content before returning.

  6352. **

  6353. ** The typedef is necessary to work around problems in certain

  6354. ** C++ compilers.

  6355. */

  6356. typedef void (*sqlite3_destructor_type)(void*);

  6357. #define SQLITE_STATIC      ((sqlite3_destructor_type)0)

  6358. #define SQLITE_TRANSIENT   ((sqlite3_destructor_type)-1)

  6359. 

  6360. /*

  6361. ** CAPI3REF: Setting The Result Of An SQL Function

  6362. ** METHOD: sqlite3_context

  6363. **

  6364. ** These routines are used by the xFunc or xFinal callbacks that

  6365. ** implement SQL functions and aggregates.  See

  6366. ** [sqlite3_create_function()] and [sqlite3_create_function16()]

  6367. ** for additional information.

  6368. **

  6369. ** These functions work very much like the [parameter binding] family of

  6370. ** functions used to bind values to host parameters in prepared statements.

  6371. ** Refer to the [SQL parameter] documentation for additional information.

  6372. **

  6373. ** ^The sqlite3_result_blob() interface sets the result from

  6374. ** an application-defined function to be the BLOB whose content is pointed

  6375. ** to by the second parameter and which is N bytes long where N is the

  6376. ** third parameter.

  6377. **

  6378. ** ^The sqlite3_result_zeroblob(C,N) and sqlite3_result_zeroblob64(C,N)

  6379. ** interfaces set the result of the application-defined function to be

  6380. ** a BLOB containing all zero bytes and N bytes in size.

  6381. **

  6382. ** ^The sqlite3_result_double() interface sets the result from

  6383. ** an application-defined function to be a floating point value specified

  6384. ** by its 2nd argument.

  6385. **

  6386. ** ^The sqlite3_result_error() and sqlite3_result_error16() functions

  6387. ** cause the implemented SQL function to throw an exception.

  6388. ** ^SQLite uses the string pointed to by the

  6389. ** 2nd parameter of sqlite3_result_error() or sqlite3_result_error16()

  6390. ** as the text of an error message.  ^SQLite interprets the error

  6391. ** message string from sqlite3_result_error() as UTF-8. ^SQLite

  6392. ** interprets the string from sqlite3_result_error16() as UTF-16 in native

  6393. ** byte order.  ^If the third parameter to sqlite3_result_error()

  6394. ** or sqlite3_result_error16() is negative then SQLite takes as the error

  6395. ** message all text up through the first zero character.

  6396. ** ^If the third parameter to sqlite3_result_error() or

  6397. ** sqlite3_result_error16() is non-negative then SQLite takes that many

  6398. ** bytes (not characters) from the 2nd parameter as the error message.

  6399. ** ^The sqlite3_result_error() and sqlite3_result_error16()

  6400. ** routines make a private copy of the error message text before

  6401. ** they return.  Hence, the calling function can deallocate or

  6402. ** modify the text after they return without harm.

  6403. ** ^The sqlite3_result_error_code() function changes the error code

  6404. ** returned by SQLite as a result of an error in a function.  ^By default,

  6405. ** the error code is SQLITE_ERROR.  ^A subsequent call to sqlite3_result_error()

  6406. ** or sqlite3_result_error16() resets the error code to SQLITE_ERROR.

  6407. **

  6408. ** ^The sqlite3_result_error_toobig() interface causes SQLite to throw an

  6409. ** error indicating that a string or BLOB is too long to represent.

  6410. **

  6411. ** ^The sqlite3_result_error_nomem() interface causes SQLite to throw an

  6412. ** error indicating that a memory allocation failed.

  6413. **

  6414. ** ^The sqlite3_result_int() interface sets the return value

  6415. ** of the application-defined function to be the 32-bit signed integer

  6416. ** value given in the 2nd argument.

  6417. ** ^The sqlite3_result_int64() interface sets the return value

  6418. ** of the application-defined function to be the 64-bit signed integer

  6419. ** value given in the 2nd argument.

  6420. **

  6421. ** ^The sqlite3_result_null() interface sets the return value

  6422. ** of the application-defined function to be NULL.

  6423. **

  6424. ** ^The sqlite3_result_text(), sqlite3_result_text16(),

  6425. ** sqlite3_result_text16le(), and sqlite3_result_text16be() interfaces

  6426. ** set the return value of the application-defined function to be

  6427. ** a text string which is represented as UTF-8, UTF-16 native byte order,

  6428. ** UTF-16 little endian, or UTF-16 big endian, respectively.

  6429. ** ^The sqlite3_result_text64() interface sets the return value of an

  6430. ** application-defined function to be a text string in an encoding

  6431. ** specified by the fifth (and last) parameter, which must be one

  6432. ** of [SQLITE_UTF8], [SQLITE_UTF16], [SQLITE_UTF16BE], or [SQLITE_UTF16LE].

  6433. ** ^SQLite takes the text result from the application from

  6434. ** the 2nd parameter of the sqlite3_result_text* interfaces.

  6435. ** ^If the 3rd parameter to the sqlite3_result_text* interfaces

  6436. ** is negative, then SQLite takes result text from the 2nd parameter

  6437. ** through the first zero character.

  6438. ** ^If the 3rd parameter to the sqlite3_result_text* interfaces

  6439. ** is non-negative, then as many bytes (not characters) of the text

  6440. ** pointed to by the 2nd parameter are taken as the application-defined

  6441. ** function result.  If the 3rd parameter is non-negative, then it

  6442. ** must be the byte offset into the string where the NUL terminator would

  6443. ** appear if the string where NUL terminated.  If any NUL characters occur

  6444. ** in the string at a byte offset that is less than the value of the 3rd

  6445. ** parameter, then the resulting string will contain embedded NULs and the

  6446. ** result of expressions operating on strings with embedded NULs is undefined.

  6447. ** ^If the 4th parameter to the sqlite3_result_text* interfaces

  6448. ** or sqlite3_result_blob is a non-NULL pointer, then SQLite calls that

  6449. ** function as the destructor on the text or BLOB result when it has

  6450. ** finished using that result.

  6451. ** ^If the 4th parameter to the sqlite3_result_text* interfaces or to

  6452. ** sqlite3_result_blob is the special constant SQLITE_STATIC, then SQLite

  6453. ** assumes that the text or BLOB result is in constant space and does not

  6454. ** copy the content of the parameter nor call a destructor on the content

  6455. ** when it has finished using that result.

  6456. ** ^If the 4th parameter to the sqlite3_result_text* interfaces

  6457. ** or sqlite3_result_blob is the special constant SQLITE_TRANSIENT

  6458. ** then SQLite makes a copy of the result into space obtained

  6459. ** from [sqlite3_malloc()] before it returns.

  6460. **

  6461. ** ^The sqlite3_result_value() interface sets the result of

  6462. ** the application-defined function to be a copy of the

  6463. ** [unprotected sqlite3_value] object specified by the 2nd parameter.  ^The

  6464. ** sqlite3_result_value() interface makes a copy of the [sqlite3_value]

  6465. ** so that the [sqlite3_value] specified in the parameter may change or

  6466. ** be deallocated after sqlite3_result_value() returns without harm.

  6467. ** ^A [protected sqlite3_value] object may always be used where an

  6468. ** [unprotected sqlite3_value] object is required, so either

  6469. ** kind of [sqlite3_value] object can be used with this interface.

  6470. **

  6471. ** ^The sqlite3_result_pointer(C,P,T,D) interface sets the result to an

  6472. ** SQL NULL value, just like [sqlite3_result_null(C)], except that it

  6473. ** also associates the host-language pointer P or type T with that 

  6474. ** NULL value such that the pointer can be retrieved within an

  6475. ** [application-defined SQL function] using [sqlite3_value_pointer()].

  6476. ** ^If the D parameter is not NULL, then it is a pointer to a destructor

  6477. ** for the P parameter.  ^SQLite invokes D with P as its only argument

  6478. ** when SQLite is finished with P.  The T parameter should be a static

  6479. ** string and preferably a string literal. The sqlite3_result_pointer()

  6480. ** routine is part of the [pointer passing interface] added for SQLite 3.20.0.

  6481. **

  6482. ** If these routines are called from within the different thread

  6483. ** than the one containing the application-defined function that received

  6484. ** the [sqlite3_context] pointer, the results are undefined.

  6485. */

  6486. SQLITE_API void sqlite3_result_blob(sqlite3_context*, const void*, int, void(*)(void*));

  6487. SQLITE_API void sqlite3_result_blob64(sqlite3_context*,const void*,

  6488.                            sqlite3_uint64,void(*)(void*));

  6489. SQLITE_API void sqlite3_result_double(sqlite3_context*, double);

  6490. SQLITE_API void sqlite3_result_error(sqlite3_context*, const char*, int);

  6491. SQLITE_API void sqlite3_result_error16(sqlite3_context*, const void*, int);

  6492. SQLITE_API void sqlite3_result_error_toobig(sqlite3_context*);

  6493. SQLITE_API void sqlite3_result_error_nomem(sqlite3_context*);

  6494. SQLITE_API void sqlite3_result_error_code(sqlite3_context*, int);

  6495. SQLITE_API void sqlite3_result_int(sqlite3_context*, int);

  6496. SQLITE_API void sqlite3_result_int64(sqlite3_context*, sqlite3_int64);

  6497. SQLITE_API void sqlite3_result_null(sqlite3_context*);

  6498. SQLITE_API void sqlite3_result_text(sqlite3_context*, const char*, int, void(*)(void*));

  6499. SQLITE_API void sqlite3_result_text64(sqlite3_context*, const char*,sqlite3_uint64,

  6500.                            void(*)(void*), unsigned char encoding);

  6501. SQLITE_API void sqlite3_result_text16(sqlite3_context*, const void*, int, void(*)(void*));

  6502. SQLITE_API void sqlite3_result_text16le(sqlite3_context*, const void*, int,void(*)(void*));

  6503. SQLITE_API void sqlite3_result_text16be(sqlite3_context*, const void*, int,void(*)(void*));

  6504. SQLITE_API void sqlite3_result_value(sqlite3_context*, sqlite3_value*);

  6505. SQLITE_API void sqlite3_result_pointer(sqlite3_context*, void*,const char*,void(*)(void*));

  6506. SQLITE_API void sqlite3_result_zeroblob(sqlite3_context*, int n);

  6507. SQLITE_API int sqlite3_result_zeroblob64(sqlite3_context*, sqlite3_uint64 n);

  6508. 

  6509. 

  6510. /*

  6511. ** CAPI3REF: Setting The Subtype Of An SQL Function

  6512. ** METHOD: sqlite3_context

  6513. **

  6514. ** The sqlite3_result_subtype(C,T) function causes the subtype of

  6515. ** the result from the [application-defined SQL function] with 

  6516. ** [sqlite3_context] C to be the value T.  Only the lower 8 bits 

  6517. ** of the subtype T are preserved in current versions of SQLite;

  6518. ** higher order bits are discarded.

  6519. ** The number of subtype bytes preserved by SQLite might increase

  6520. ** in future releases of SQLite.

  6521. */

  6522. SQLITE_API void sqlite3_result_subtype(sqlite3_context*,unsigned int);

  6523. 

  6524. /*

  6525. ** CAPI3REF: Define New Collating Sequences

  6526. ** METHOD: sqlite3

  6527. **

  6528. ** ^These functions add, remove, or modify a [collation] associated

  6529. ** with the [database connection] specified as the first argument.

  6530. **

  6531. ** ^The name of the collation is a UTF-8 string

  6532. ** for sqlite3_create_collation() and sqlite3_create_collation_v2()

  6533. ** and a UTF-16 string in native byte order for sqlite3_create_collation16().

  6534. ** ^Collation names that compare equal according to [sqlite3_strnicmp()] are

  6535. ** considered to be the same name.

  6536. **

  6537. ** ^(The third argument (eTextRep) must be one of the constants:

  6538. ** <ul>

  6539. ** <li> [SQLITE_UTF8],

  6540. ** <li> [SQLITE_UTF16LE],

  6541. ** <li> [SQLITE_UTF16BE],

  6542. ** <li> [SQLITE_UTF16], or

  6543. ** <li> [SQLITE_UTF16_ALIGNED].

  6544. ** </ul>)^

  6545. ** ^The eTextRep argument determines the encoding of strings passed

  6546. ** to the collating function callback, xCallback.

  6547. ** ^The [SQLITE_UTF16] and [SQLITE_UTF16_ALIGNED] values for eTextRep

  6548. ** force strings to be UTF16 with native byte order.

  6549. ** ^The [SQLITE_UTF16_ALIGNED] value for eTextRep forces strings to begin

  6550. ** on an even byte address.

  6551. **

  6552. ** ^The fourth argument, pArg, is an application data pointer that is passed

  6553. ** through as the first argument to the collating function callback.

  6554. **

  6555. ** ^The fifth argument, xCallback, is a pointer to the collating function.

  6556. ** ^Multiple collating functions can be registered using the same name but

  6557. ** with different eTextRep parameters and SQLite will use whichever

  6558. ** function requires the least amount of data transformation.

  6559. ** ^If the xCallback argument is NULL then the collating function is

  6560. ** deleted.  ^When all collating functions having the same name are deleted,

  6561. ** that collation is no longer usable.

  6562. **

  6563. ** ^The collating function callback is invoked with a copy of the pArg 

  6564. ** application data pointer and with two strings in the encoding specified

  6565. ** by the eTextRep argument.  The collating function must return an

  6566. ** integer that is negative, zero, or positive

  6567. ** if the first string is less than, equal to, or greater than the second,

  6568. ** respectively.  A collating function must always return the same answer

  6569. ** given the same inputs.  If two or more collating functions are registered

  6570. ** to the same collation name (using different eTextRep values) then all

  6571. ** must give an equivalent answer when invoked with equivalent strings.

  6572. ** The collating function must obey the following properties for all

  6573. ** strings A, B, and C:

  6574. **

  6575. ** <ol>

  6576. ** <li> If A==B then B==A.

  6577. ** <li> If A==B and B==C then A==C.

  6578. ** <li> If A&lt;B THEN B&gt;A.

  6579. ** <li> If A&lt;B and B&lt;C then A&lt;C.

  6580. ** </ol>

  6581. **

  6582. ** If a collating function fails any of the above constraints and that

  6583. ** collating function is  registered and used, then the behavior of SQLite

  6584. ** is undefined.

  6585. **

  6586. ** ^The sqlite3_create_collation_v2() works like sqlite3_create_collation()

  6587. ** with the addition that the xDestroy callback is invoked on pArg when

  6588. ** the collating function is deleted.

  6589. ** ^Collating functions are deleted when they are overridden by later

  6590. ** calls to the collation creation functions or when the

  6591. ** [database connection] is closed using [sqlite3_close()].

  6592. **

  6593. ** ^The xDestroy callback is <u>not</u> called if the 

  6594. ** sqlite3_create_collation_v2() function fails.  Applications that invoke

  6595. ** sqlite3_create_collation_v2() with a non-NULL xDestroy argument should 

  6596. ** check the return code and dispose of the application data pointer

  6597. ** themselves rather than expecting SQLite to deal with it for them.

  6598. ** This is different from every other SQLite interface.  The inconsistency 

  6599. ** is unfortunate but cannot be changed without breaking backwards 

  6600. ** compatibility.

  6601. **

  6602. ** See also:  [sqlite3_collation_needed()] and [sqlite3_collation_needed16()].

  6603. */

  6604. SQLITE_API int sqlite3_create_collation(

  6605.   sqlite3*, 

  6606.   const char *zName, 

  6607.   int eTextRep, 

  6608.   void *pArg,

  6609.   int(*xCompare)(void*,int,const void*,int,const void*)

  6610. );

  6611. SQLITE_API int sqlite3_create_collation_v2(

  6612.   sqlite3*, 

  6613.   const char *zName, 

  6614.   int eTextRep, 

  6615.   void *pArg,

  6616.   int(*xCompare)(void*,int,const void*,int,const void*),

  6617.   void(*xDestroy)(void*)

  6618. );

  6619. SQLITE_API int sqlite3_create_collation16(

  6620.   sqlite3*, 

  6621.   const void *zName,

  6622.   int eTextRep, 

  6623.   void *pArg,

  6624.   int(*xCompare)(void*,int,const void*,int,const void*)

  6625. );

  6626. 

  6627. /*

  6628. ** CAPI3REF: Collation Needed Callbacks

  6629. ** METHOD: sqlite3

  6630. **

  6631. ** ^To avoid having to register all collation sequences before a database

  6632. ** can be used, a single callback function may be registered with the

  6633. ** [database connection] to be invoked whenever an undefined collation

  6634. ** sequence is required.

  6635. **

  6636. ** ^If the function is registered using the sqlite3_collation_needed() API,

  6637. ** then it is passed the names of undefined collation sequences as strings

  6638. ** encoded in UTF-8. ^If sqlite3_collation_needed16() is used,

  6639. ** the names are passed as UTF-16 in machine native byte order.

  6640. ** ^A call to either function replaces the existing collation-needed callback.

  6641. **

  6642. ** ^(When the callback is invoked, the first argument passed is a copy

  6643. ** of the second argument to sqlite3_collation_needed() or

  6644. ** sqlite3_collation_needed16().  The second argument is the database

  6645. ** connection.  The third argument is one of [SQLITE_UTF8], [SQLITE_UTF16BE],

  6646. ** or [SQLITE_UTF16LE], indicating the most desirable form of the collation

  6647. ** sequence function required.  The fourth parameter is the name of the

  6648. ** required collation sequence.)^

  6649. **

  6650. ** The callback function should register the desired collation using

  6651. ** [sqlite3_create_collation()], [sqlite3_create_collation16()], or

  6652. ** [sqlite3_create_collation_v2()].

  6653. */

  6654. SQLITE_API int sqlite3_collation_needed(

  6655.   sqlite3*, 

  6656.   void*, 

  6657.   void(*)(void*,sqlite3*,int eTextRep,const char*)

  6658. );

  6659. SQLITE_API int sqlite3_collation_needed16(

  6660.   sqlite3*, 

  6661.   void*,

  6662.   void(*)(void*,sqlite3*,int eTextRep,const void*)

  6663. );

  6664. 

  6665. #ifdef SQLITE_HAS_CODEC

  6666. /*

  6667. ** Specify the key for an encrypted database.  This routine should be

  6668. ** called right after sqlite3_open().

  6669. **

  6670. ** The code to implement this API is not available in the public release

  6671. ** of SQLite.

  6672. */

  6673. SQLITE_API int sqlite3_key(

  6674.   sqlite3 *db,                   /* Database to be rekeyed */

  6675.   const void *pKey, int nKey     /* The key */

  6676. );

  6677. SQLITE_API int sqlite3_key_v2(

  6678.   sqlite3 *db,                   /* Database to be rekeyed */

  6679.   const char *zDbName,           /* Name of the database */

  6680.   const void *pKey, int nKey     /* The key */

  6681. );

  6682. 

  6683. /*

  6684. ** Change the key on an open database.  If the current database is not

  6685. ** encrypted, this routine will encrypt it.  If pNew==0 or nNew==0, the

  6686. ** database is decrypted.

  6687. **

  6688. ** The code to implement this API is not available in the public release

  6689. ** of SQLite.

  6690. */

  6691. SQLITE_API int sqlite3_rekey(

  6692.   sqlite3 *db,                   /* Database to be rekeyed */

  6693.   const void *pKey, int nKey     /* The new key */

  6694. );

  6695. SQLITE_API int sqlite3_rekey_v2(

  6696.   sqlite3 *db,                   /* Database to be rekeyed */

  6697.   const char *zDbName,           /* Name of the database */

  6698.   const void *pKey, int nKey     /* The new key */

  6699. );

  6700. 

  6701. /*

  6702. ** Specify the activation key for a SEE database.  Unless 

  6703. ** activated, none of the SEE routines will work.

  6704. */

  6705. SQLITE_API void sqlite3_activate_see(

  6706.   const char *zPassPhrase        /* Activation phrase */

  6707. );

  6708. #endif

  6709. 

  6710. #ifdef SQLITE_ENABLE_CEROD

  6711. /*

  6712. ** Specify the activation key for a CEROD database.  Unless 

  6713. ** activated, none of the CEROD routines will work.

  6714. */

  6715. SQLITE_API void sqlite3_activate_cerod(

  6716.   const char *zPassPhrase        /* Activation phrase */

  6717. );

  6718. #endif

  6719. 

  6720. /*

  6721. ** CAPI3REF: Suspend Execution For A Short Time

  6722. **

  6723. ** The sqlite3_sleep() function causes the current thread to suspend execution

  6724. ** for at least a number of milliseconds specified in its parameter.

  6725. **

  6726. ** If the operating system does not support sleep requests with

  6727. ** millisecond time resolution, then the time will be rounded up to

  6728. ** the nearest second. The number of milliseconds of sleep actually

  6729. ** requested from the operating system is returned.

  6730. **

  6731. ** ^SQLite implements this interface by calling the xSleep()

  6732. ** method of the default [sqlite3_vfs] object.  If the xSleep() method

  6733. ** of the default VFS is not implemented correctly, or not implemented at

  6734. ** all, then the behavior of sqlite3_sleep() may deviate from the description

  6735. ** in the previous paragraphs.

  6736. */

  6737. SQLITE_API int sqlite3_sleep(int);

  6738. 

  6739. /*

  6740. ** CAPI3REF: Name Of The Folder Holding Temporary Files

  6741. **

  6742. ** ^(If this global variable is made to point to a string which is

  6743. ** the name of a folder (a.k.a. directory), then all temporary files

  6744. ** created by SQLite when using a built-in [sqlite3_vfs | VFS]

  6745. ** will be placed in that directory.)^  ^If this variable

  6746. ** is a NULL pointer, then SQLite performs a search for an appropriate

  6747. ** temporary file directory.

  6748. **

  6749. ** Applications are strongly discouraged from using this global variable.

  6750. ** It is required to set a temporary folder on Windows Runtime (WinRT).

  6751. ** But for all other platforms, it is highly recommended that applications

  6752. ** neither read nor write this variable.  This global variable is a relic

  6753. ** that exists for backwards compatibility of legacy applications and should

  6754. ** be avoided in new projects.

  6755. **

  6756. ** It is not safe to read or modify this variable in more than one

  6757. ** thread at a time.  It is not safe to read or modify this variable

  6758. ** if a [database connection] is being used at the same time in a separate

  6759. ** thread.

  6760. ** It is intended that this variable be set once

  6761. ** as part of process initialization and before any SQLite interface

  6762. ** routines have been called and that this variable remain unchanged

  6763. ** thereafter.

  6764. **

  6765. ** ^The [temp_store_directory pragma] may modify this variable and cause

  6766. ** it to point to memory obtained from [sqlite3_malloc].  ^Furthermore,

  6767. ** the [temp_store_directory pragma] always assumes that any string

  6768. ** that this variable points to is held in memory obtained from 

  6769. ** [sqlite3_malloc] and the pragma may attempt to free that memory

  6770. ** using [sqlite3_free].

  6771. ** Hence, if this variable is modified directly, either it should be

  6772. ** made NULL or made to point to memory obtained from [sqlite3_malloc]

  6773. ** or else the use of the [temp_store_directory pragma] should be avoided.

  6774. ** Except when requested by the [temp_store_directory pragma], SQLite

  6775. ** does not free the memory that sqlite3_temp_directory points to.  If

  6776. ** the application wants that memory to be freed, it must do

  6777. ** so itself, taking care to only do so after all [database connection]

  6778. ** objects have been destroyed.

  6779. **

  6780. ** <b>Note to Windows Runtime users:</b>  The temporary directory must be set

  6781. ** prior to calling [sqlite3_open] or [sqlite3_open_v2].  Otherwise, various

  6782. ** features that require the use of temporary files may fail.  Here is an

  6783. ** example of how to do this using C++ with the Windows Runtime:

  6784. **

  6785. ** <blockquote><pre>

  6786. ** LPCWSTR zPath = Windows::Storage::ApplicationData::Current->

  6787. ** &nbsp;     TemporaryFolder->Path->Data();

  6788. ** char zPathBuf&#91;MAX_PATH + 1&#93;;

  6789. ** memset(zPathBuf, 0, sizeof(zPathBuf));

  6790. ** WideCharToMultiByte(CP_UTF8, 0, zPath, -1, zPathBuf, sizeof(zPathBuf),

  6791. ** &nbsp;     NULL, NULL);

  6792. ** sqlite3_temp_directory = sqlite3_mprintf("%s", zPathBuf);

  6793. ** </pre></blockquote>

  6794. */

  6795. SQLITE_API char *sqlite3_temp_directory;

  6796. 

  6797. /*

  6798. ** CAPI3REF: Name Of The Folder Holding Database Files

  6799. **

  6800. ** ^(If this global variable is made to point to a string which is

  6801. ** the name of a folder (a.k.a. directory), then all database files

  6802. ** specified with a relative pathname and created or accessed by

  6803. ** SQLite when using a built-in windows [sqlite3_vfs | VFS] will be assumed

  6804. ** to be relative to that directory.)^ ^If this variable is a NULL

  6805. ** pointer, then SQLite assumes that all database files specified

  6806. ** with a relative pathname are relative to the current directory

  6807. ** for the process.  Only the windows VFS makes use of this global

  6808. ** variable; it is ignored by the unix VFS.

  6809. **

  6810. ** Changing the value of this variable while a database connection is

  6811. ** open can result in a corrupt database.

  6812. **

  6813. ** It is not safe to read or modify this variable in more than one

  6814. ** thread at a time.  It is not safe to read or modify this variable

  6815. ** if a [database connection] is being used at the same time in a separate

  6816. ** thread.

  6817. ** It is intended that this variable be set once

  6818. ** as part of process initialization and before any SQLite interface

  6819. ** routines have been called and that this variable remain unchanged

  6820. ** thereafter.

  6821. **

  6822. ** ^The [data_store_directory pragma] may modify this variable and cause

  6823. ** it to point to memory obtained from [sqlite3_malloc].  ^Furthermore,

  6824. ** the [data_store_directory pragma] always assumes that any string

  6825. ** that this variable points to is held in memory obtained from 

  6826. ** [sqlite3_malloc] and the pragma may attempt to free that memory

  6827. ** using [sqlite3_free].

  6828. ** Hence, if this variable is modified directly, either it should be

  6829. ** made NULL or made to point to memory obtained from [sqlite3_malloc]

  6830. ** or else the use of the [data_store_directory pragma] should be avoided.

  6831. */

  6832. SQLITE_API char *sqlite3_data_directory;

  6833. 

  6834. /*

  6835. ** CAPI3REF: Win32 Specific Interface

  6836. **

  6837. ** These interfaces are available only on Windows.  The

  6838. ** [sqlite3_win32_set_directory] interface is used to set the value associated

  6839. ** with the [sqlite3_temp_directory] or [sqlite3_data_directory] variable, to

  6840. ** zValue, depending on the value of the type parameter.  The zValue parameter

  6841. ** should be NULL to cause the previous value to be freed via [sqlite3_free];

  6842. ** a non-NULL value will be copied into memory obtained from [sqlite3_malloc]

  6843. ** prior to being used.  The [sqlite3_win32_set_directory] interface returns

  6844. ** [SQLITE_OK] to indicate success, [SQLITE_ERROR] if the type is unsupported,

  6845. ** or [SQLITE_NOMEM] if memory could not be allocated.  The value of the

  6846. ** [sqlite3_data_directory] variable is intended to act as a replacement for

  6847. ** the current directory on the sub-platforms of Win32 where that concept is

  6848. ** not present, e.g. WinRT and UWP.  The [sqlite3_win32_set_directory8] and

  6849. ** [sqlite3_win32_set_directory16] interfaces behave exactly the same as the

  6850. ** sqlite3_win32_set_directory interface except the string parameter must be

  6851. ** UTF-8 or UTF-16, respectively.

  6852. */

  6853. SQLITE_API int sqlite3_win32_set_directory(

  6854.   unsigned long type, /* Identifier for directory being set or reset */

  6855.   void *zValue        /* New value for directory being set or reset */

  6856. );

  6857. SQLITE_API int sqlite3_win32_set_directory8(unsigned long type, const char *zValue);

  6858. SQLITE_API int sqlite3_win32_set_directory16(unsigned long type, const void *zValue);

  6859. 

  6860. /*

  6861. ** CAPI3REF: Win32 Directory Types

  6862. **

  6863. ** These macros are only available on Windows.  They define the allowed values

  6864. ** for the type argument to the [sqlite3_win32_set_directory] interface.

  6865. */

  6866. #define SQLITE_WIN32_DATA_DIRECTORY_TYPE  1

  6867. #define SQLITE_WIN32_TEMP_DIRECTORY_TYPE  2

  6868. 

  6869. /*

  6870. ** CAPI3REF: Test For Auto-Commit Mode

  6871. ** KEYWORDS: {autocommit mode}

  6872. ** METHOD: sqlite3

  6873. **

  6874. ** ^The sqlite3_get_autocommit() interface returns non-zero or

  6875. ** zero if the given database connection is or is not in autocommit mode,

  6876. ** respectively.  ^Autocommit mode is on by default.

  6877. ** ^Autocommit mode is disabled by a [BEGIN] statement.

  6878. ** ^Autocommit mode is re-enabled by a [COMMIT] or [ROLLBACK].

  6879. **

  6880. ** If certain kinds of errors occur on a statement within a multi-statement

  6881. ** transaction (errors including [SQLITE_FULL], [SQLITE_IOERR],

  6882. ** [SQLITE_NOMEM], [SQLITE_BUSY], and [SQLITE_INTERRUPT]) then the

  6883. ** transaction might be rolled back automatically.  The only way to

  6884. ** find out whether SQLite automatically rolled back the transaction after

  6885. ** an error is to use this function.

  6886. **

  6887. ** If another thread changes the autocommit status of the database

  6888. ** connection while this routine is running, then the return value

  6889. ** is undefined.

  6890. */

  6891. SQLITE_API int sqlite3_get_autocommit(sqlite3*);

  6892. 

  6893. /*

  6894. ** CAPI3REF: Find The Database Handle Of A Prepared Statement

  6895. ** METHOD: sqlite3_stmt

  6896. **

  6897. ** ^The sqlite3_db_handle interface returns the [database connection] handle

  6898. ** to which a [prepared statement] belongs.  ^The [database connection]

  6899. ** returned by sqlite3_db_handle is the same [database connection]

  6900. ** that was the first argument

  6901. ** to the [sqlite3_prepare_v2()] call (or its variants) that was used to

  6902. ** create the statement in the first place.

  6903. */

  6904. SQLITE_API sqlite3 *sqlite3_db_handle(sqlite3_stmt*);

  6905. 

  6906. /*

  6907. ** CAPI3REF: Return The Filename For A Database Connection

  6908. ** METHOD: sqlite3

  6909. **

  6910. ** ^The sqlite3_db_filename(D,N) interface returns a pointer to a filename

  6911. ** associated with database N of connection D.  ^The main database file

  6912. ** has the name "main".  If there is no attached database N on the database

  6913. ** connection D, or if database N is a temporary or in-memory database, then

  6914. ** this function will return either a NULL pointer or an empty string.

  6915. **

  6916. ** ^The filename returned by this function is the output of the

  6917. ** xFullPathname method of the [VFS].  ^In other words, the filename

  6918. ** will be an absolute pathname, even if the filename used

  6919. ** to open the database originally was a URI or relative pathname.

  6920. */

  6921. SQLITE_API const char *sqlite3_db_filename(sqlite3 *db, const char *zDbName);

  6922. 

  6923. /*

  6924. ** CAPI3REF: Determine if a database is read-only

  6925. ** METHOD: sqlite3

  6926. **

  6927. ** ^The sqlite3_db_readonly(D,N) interface returns 1 if the database N

  6928. ** of connection D is read-only, 0 if it is read/write, or -1 if N is not

  6929. ** the name of a database on connection D.

  6930. */

  6931. SQLITE_API int sqlite3_db_readonly(sqlite3 *db, const char *zDbName);

  6932. 

  6933. /*

  6934. ** CAPI3REF: Find the next prepared statement

  6935. ** METHOD: sqlite3

  6936. **

  6937. ** ^This interface returns a pointer to the next [prepared statement] after

  6938. ** pStmt associated with the [database connection] pDb.  ^If pStmt is NULL

  6939. ** then this interface returns a pointer to the first prepared statement

  6940. ** associated with the database connection pDb.  ^If no prepared statement

  6941. ** satisfies the conditions of this routine, it returns NULL.

  6942. **

  6943. ** The [database connection] pointer D in a call to

  6944. ** [sqlite3_next_stmt(D,S)] must refer to an open database

  6945. ** connection and in particular must not be a NULL pointer.

  6946. */

  6947. SQLITE_API sqlite3_stmt *sqlite3_next_stmt(sqlite3 *pDb, sqlite3_stmt *pStmt);

  6948. 

  6949. /*

  6950. ** CAPI3REF: Commit And Rollback Notification Callbacks

  6951. ** METHOD: sqlite3

  6952. **

  6953. ** ^The sqlite3_commit_hook() interface registers a callback

  6954. ** function to be invoked whenever a transaction is [COMMIT | committed].

  6955. ** ^Any callback set by a previous call to sqlite3_commit_hook()

  6956. ** for the same database connection is overridden.

  6957. ** ^The sqlite3_rollback_hook() interface registers a callback

  6958. ** function to be invoked whenever a transaction is [ROLLBACK | rolled back].

  6959. ** ^Any callback set by a previous call to sqlite3_rollback_hook()

  6960. ** for the same database connection is overridden.

  6961. ** ^The pArg argument is passed through to the callback.

  6962. ** ^If the callback on a commit hook function returns non-zero,

  6963. ** then the commit is converted into a rollback.

  6964. **

  6965. ** ^The sqlite3_commit_hook(D,C,P) and sqlite3_rollback_hook(D,C,P) functions

  6966. ** return the P argument from the previous call of the same function

  6967. ** on the same [database connection] D, or NULL for

  6968. ** the first call for each function on D.

  6969. **

  6970. ** The commit and rollback hook callbacks are not reentrant.

  6971. ** The callback implementation must not do anything that will modify

  6972. ** the database connection that invoked the callback.  Any actions

  6973. ** to modify the database connection must be deferred until after the

  6974. ** completion of the [sqlite3_step()] call that triggered the commit

  6975. ** or rollback hook in the first place.

  6976. ** Note that running any other SQL statements, including SELECT statements,

  6977. ** or merely calling [sqlite3_prepare_v2()] and [sqlite3_step()] will modify

  6978. ** the database connections for the meaning of "modify" in this paragraph.

  6979. **

  6980. ** ^Registering a NULL function disables the callback.

  6981. **

  6982. ** ^When the commit hook callback routine returns zero, the [COMMIT]

  6983. ** operation is allowed to continue normally.  ^If the commit hook

  6984. ** returns non-zero, then the [COMMIT] is converted into a [ROLLBACK].

  6985. ** ^The rollback hook is invoked on a rollback that results from a commit

  6986. ** hook returning non-zero, just as it would be with any other rollback.

  6987. **

  6988. ** ^For the purposes of this API, a transaction is said to have been

  6989. ** rolled back if an explicit "ROLLBACK" statement is executed, or

  6990. ** an error or constraint causes an implicit rollback to occur.

  6991. ** ^The rollback callback is not invoked if a transaction is

  6992. ** automatically rolled back because the database connection is closed.

  6993. **

  6994. ** See also the [sqlite3_update_hook()] interface.

  6995. */

  6996. SQLITE_API void *sqlite3_commit_hook(sqlite3*, int(*)(void*), void*);

  6997. SQLITE_API void *sqlite3_rollback_hook(sqlite3*, void(*)(void *), void*);

  6998. 

  6999. /*

  7000. ** CAPI3REF: Data Change Notification Callbacks

  7001. ** METHOD: sqlite3

  7002. **

  7003. ** ^The sqlite3_update_hook() interface registers a callback function

  7004. ** with the [database connection] identified by the first argument

  7005. ** to be invoked whenever a row is updated, inserted or deleted in

  7006. ** a [rowid table].

  7007. ** ^Any callback set by a previous call to this function

  7008. ** for the same database connection is overridden.

  7009. **

  7010. ** ^The second argument is a pointer to the function to invoke when a

  7011. ** row is updated, inserted or deleted in a rowid table.

  7012. ** ^The first argument to the callback is a copy of the third argument

  7013. ** to sqlite3_update_hook().

  7014. ** ^The second callback argument is one of [SQLITE_INSERT], [SQLITE_DELETE],

  7015. ** or [SQLITE_UPDATE], depending on the operation that caused the callback

  7016. ** to be invoked.

  7017. ** ^The third and fourth arguments to the callback contain pointers to the

  7018. ** database and table name containing the affected row.

  7019. ** ^The final callback parameter is the [rowid] of the row.

  7020. ** ^In the case of an update, this is the [rowid] after the update takes place.

  7021. **

  7022. ** ^(The update hook is not invoked when internal system tables are

  7023. ** modified (i.e. sqlite_master and sqlite_sequence).)^

  7024. ** ^The update hook is not invoked when [WITHOUT ROWID] tables are modified.

  7025. **

  7026. ** ^In the current implementation, the update hook

  7027. ** is not invoked when conflicting rows are deleted because of an

  7028. ** [ON CONFLICT | ON CONFLICT REPLACE] clause.  ^Nor is the update hook

  7029. ** invoked when rows are deleted using the [truncate optimization].

  7030. ** The exceptions defined in this paragraph might change in a future

  7031. ** release of SQLite.

  7032. **

  7033. ** The update hook implementation must not do anything that will modify

  7034. ** the database connection that invoked the update hook.  Any actions

  7035. ** to modify the database connection must be deferred until after the

  7036. ** completion of the [sqlite3_step()] call that triggered the update hook.

  7037. ** Note that [sqlite3_prepare_v2()] and [sqlite3_step()] both modify their

  7038. ** database connections for the meaning of "modify" in this paragraph.

  7039. **

  7040. ** ^The sqlite3_update_hook(D,C,P) function

  7041. ** returns the P argument from the previous call

  7042. ** on the same [database connection] D, or NULL for

  7043. ** the first call on D.

  7044. **

  7045. ** See also the [sqlite3_commit_hook()], [sqlite3_rollback_hook()],

  7046. ** and [sqlite3_preupdate_hook()] interfaces.

  7047. */

  7048. SQLITE_API void *sqlite3_update_hook(

  7049.   sqlite3*, 

  7050.   void(*)(void *,int ,char const *,char const *,sqlite3_int64),

  7051.   void*

  7052. );

  7053. 

  7054. /*

  7055. ** CAPI3REF: Enable Or Disable Shared Pager Cache

  7056. **

  7057. ** ^(This routine enables or disables the sharing of the database cache

  7058. ** and schema data structures between [database connection | connections]

  7059. ** to the same database. Sharing is enabled if the argument is true

  7060. ** and disabled if the argument is false.)^

  7061. **

  7062. ** ^Cache sharing is enabled and disabled for an entire process.

  7063. ** This is a change as of SQLite [version 3.5.0] ([dateof:3.5.0]). 

  7064. ** In prior versions of SQLite,

  7065. ** sharing was enabled or disabled for each thread separately.

  7066. **

  7067. ** ^(The cache sharing mode set by this interface effects all subsequent

  7068. ** calls to [sqlite3_open()], [sqlite3_open_v2()], and [sqlite3_open16()].

  7069. ** Existing database connections continue use the sharing mode

  7070. ** that was in effect at the time they were opened.)^

  7071. **

  7072. ** ^(This routine returns [SQLITE_OK] if shared cache was enabled or disabled

  7073. ** successfully.  An [error code] is returned otherwise.)^

  7074. **

  7075. ** ^Shared cache is disabled by default. But this might change in

  7076. ** future releases of SQLite.  Applications that care about shared

  7077. ** cache setting should set it explicitly.

  7078. **

  7079. ** Note: This method is disabled on MacOS X 10.7 and iOS version 5.0

  7080. ** and will always return SQLITE_MISUSE. On those systems, 

  7081. ** shared cache mode should be enabled per-database connection via 

  7082. ** [sqlite3_open_v2()] with [SQLITE_OPEN_SHAREDCACHE].

  7083. **

  7084. ** This interface is threadsafe on processors where writing a

  7085. ** 32-bit integer is atomic.

  7086. **

  7087. ** See Also:  [SQLite Shared-Cache Mode]

  7088. */

  7089. SQLITE_API int sqlite3_enable_shared_cache(int);

  7090. 

  7091. /*

  7092. ** CAPI3REF: Attempt To Free Heap Memory

  7093. **

  7094. ** ^The sqlite3_release_memory() interface attempts to free N bytes

  7095. ** of heap memory by deallocating non-essential memory allocations

  7096. ** held by the database library.   Memory used to cache database

  7097. ** pages to improve performance is an example of non-essential memory.

  7098. ** ^sqlite3_release_memory() returns the number of bytes actually freed,

  7099. ** which might be more or less than the amount requested.

  7100. ** ^The sqlite3_release_memory() routine is a no-op returning zero

  7101. ** if SQLite is not compiled with [SQLITE_ENABLE_MEMORY_MANAGEMENT].

  7102. **

  7103. ** See also: [sqlite3_db_release_memory()]

  7104. */

  7105. SQLITE_API int sqlite3_release_memory(int);

  7106. 

  7107. /*

  7108. ** CAPI3REF: Free Memory Used By A Database Connection

  7109. ** METHOD: sqlite3

  7110. **

  7111. ** ^The sqlite3_db_release_memory(D) interface attempts to free as much heap

  7112. ** memory as possible from database connection D. Unlike the

  7113. ** [sqlite3_release_memory()] interface, this interface is in effect even

  7114. ** when the [SQLITE_ENABLE_MEMORY_MANAGEMENT] compile-time option is

  7115. ** omitted.

  7116. **

  7117. ** See also: [sqlite3_release_memory()]

  7118. */

  7119. SQLITE_API int sqlite3_db_release_memory(sqlite3*);

  7120. 

  7121. /*

  7122. ** CAPI3REF: Impose A Limit On Heap Size

  7123. **

  7124. ** ^The sqlite3_soft_heap_limit64() interface sets and/or queries the

  7125. ** soft limit on the amount of heap memory that may be allocated by SQLite.

  7126. ** ^SQLite strives to keep heap memory utilization below the soft heap

  7127. ** limit by reducing the number of pages held in the page cache

  7128. ** as heap memory usages approaches the limit.

  7129. ** ^The soft heap limit is "soft" because even though SQLite strives to stay

  7130. ** below the limit, it will exceed the limit rather than generate

  7131. ** an [SQLITE_NOMEM] error.  In other words, the soft heap limit 

  7132. ** is advisory only.

  7133. **

  7134. ** ^The return value from sqlite3_soft_heap_limit64() is the size of

  7135. ** the soft heap limit prior to the call, or negative in the case of an

  7136. ** error.  ^If the argument N is negative

  7137. ** then no change is made to the soft heap limit.  Hence, the current

  7138. ** size of the soft heap limit can be determined by invoking

  7139. ** sqlite3_soft_heap_limit64() with a negative argument.

  7140. **

  7141. ** ^If the argument N is zero then the soft heap limit is disabled.

  7142. **

  7143. ** ^(The soft heap limit is not enforced in the current implementation

  7144. ** if one or more of following conditions are true:

  7145. **

  7146. ** <ul>

  7147. ** <li> The soft heap limit is set to zero.

  7148. ** <li> Memory accounting is disabled using a combination of the

  7149. **      [sqlite3_config]([SQLITE_CONFIG_MEMSTATUS],...) start-time option and

  7150. **      the [SQLITE_DEFAULT_MEMSTATUS] compile-time option.

  7151. ** <li> An alternative page cache implementation is specified using

  7152. **      [sqlite3_config]([SQLITE_CONFIG_PCACHE2],...).

  7153. ** <li> The page cache allocates from its own memory pool supplied

  7154. **      by [sqlite3_config]([SQLITE_CONFIG_PAGECACHE],...) rather than

  7155. **      from the heap.

  7156. ** </ul>)^

  7157. **

  7158. ** Beginning with SQLite [version 3.7.3] ([dateof:3.7.3]), 

  7159. ** the soft heap limit is enforced

  7160. ** regardless of whether or not the [SQLITE_ENABLE_MEMORY_MANAGEMENT]

  7161. ** compile-time option is invoked.  With [SQLITE_ENABLE_MEMORY_MANAGEMENT],

  7162. ** the soft heap limit is enforced on every memory allocation.  Without

  7163. ** [SQLITE_ENABLE_MEMORY_MANAGEMENT], the soft heap limit is only enforced

  7164. ** when memory is allocated by the page cache.  Testing suggests that because

  7165. ** the page cache is the predominate memory user in SQLite, most

  7166. ** applications will achieve adequate soft heap limit enforcement without

  7167. ** the use of [SQLITE_ENABLE_MEMORY_MANAGEMENT].

  7168. **

  7169. ** The circumstances under which SQLite will enforce the soft heap limit may

  7170. ** changes in future releases of SQLite.

  7171. */

  7172. SQLITE_API sqlite3_int64 sqlite3_soft_heap_limit64(sqlite3_int64 N);

  7173. 

  7174. /*

  7175. ** CAPI3REF: Deprecated Soft Heap Limit Interface

  7176. ** DEPRECATED

  7177. **

  7178. ** This is a deprecated version of the [sqlite3_soft_heap_limit64()]

  7179. ** interface.  This routine is provided for historical compatibility

  7180. ** only.  All new applications should use the

  7181. ** [sqlite3_soft_heap_limit64()] interface rather than this one.

  7182. */

  7183. SQLITE_API SQLITE_DEPRECATED void sqlite3_soft_heap_limit(int N);

  7184. 

  7185. 

  7186. /*

  7187. ** CAPI3REF: Extract Metadata About A Column Of A Table

  7188. ** METHOD: sqlite3

  7189. **

  7190. ** ^(The sqlite3_table_column_metadata(X,D,T,C,....) routine returns

  7191. ** information about column C of table T in database D

  7192. ** on [database connection] X.)^  ^The sqlite3_table_column_metadata()

  7193. ** interface returns SQLITE_OK and fills in the non-NULL pointers in

  7194. ** the final five arguments with appropriate values if the specified

  7195. ** column exists.  ^The sqlite3_table_column_metadata() interface returns

  7196. ** SQLITE_ERROR and if the specified column does not exist.

  7197. ** ^If the column-name parameter to sqlite3_table_column_metadata() is a

  7198. ** NULL pointer, then this routine simply checks for the existence of the

  7199. ** table and returns SQLITE_OK if the table exists and SQLITE_ERROR if it

  7200. ** does not.  If the table name parameter T in a call to

  7201. ** sqlite3_table_column_metadata(X,D,T,C,...) is NULL then the result is

  7202. ** undefined behavior.

  7203. **

  7204. ** ^The column is identified by the second, third and fourth parameters to

  7205. ** this function. ^(The second parameter is either the name of the database

  7206. ** (i.e. "main", "temp", or an attached database) containing the specified

  7207. ** table or NULL.)^ ^If it is NULL, then all attached databases are searched

  7208. ** for the table using the same algorithm used by the database engine to

  7209. ** resolve unqualified table references.

  7210. **

  7211. ** ^The third and fourth parameters to this function are the table and column

  7212. ** name of the desired column, respectively.

  7213. **

  7214. ** ^Metadata is returned by writing to the memory locations passed as the 5th

  7215. ** and subsequent parameters to this function. ^Any of these arguments may be

  7216. ** NULL, in which case the corresponding element of metadata is omitted.

  7217. **

  7218. ** ^(<blockquote>

  7219. ** <table border="1">

  7220. ** <tr><th> Parameter <th> Output<br>Type <th>  Description

  7221. **

  7222. ** <tr><td> 5th <td> const char* <td> Data type

  7223. ** <tr><td> 6th <td> const char* <td> Name of default collation sequence

  7224. ** <tr><td> 7th <td> int         <td> True if column has a NOT NULL constraint

  7225. ** <tr><td> 8th <td> int         <td> True if column is part of the PRIMARY KEY

  7226. ** <tr><td> 9th <td> int         <td> True if column is [AUTOINCREMENT]

  7227. ** </table>

  7228. ** </blockquote>)^

  7229. **

  7230. ** ^The memory pointed to by the character pointers returned for the

  7231. ** declaration type and collation sequence is valid until the next

  7232. ** call to any SQLite API function.

  7233. **

  7234. ** ^If the specified table is actually a view, an [error code] is returned.

  7235. **

  7236. ** ^If the specified column is "rowid", "oid" or "_rowid_" and the table 

  7237. ** is not a [WITHOUT ROWID] table and an

  7238. ** [INTEGER PRIMARY KEY] column has been explicitly declared, then the output

  7239. ** parameters are set for the explicitly declared column. ^(If there is no

  7240. ** [INTEGER PRIMARY KEY] column, then the outputs

  7241. ** for the [rowid] are set as follows:

  7242. **

  7243. ** <pre>

  7244. **     data type: "INTEGER"

  7245. **     collation sequence: "BINARY"

  7246. **     not null: 0

  7247. **     primary key: 1

  7248. **     auto increment: 0

  7249. ** </pre>)^

  7250. **

  7251. ** ^This function causes all database schemas to be read from disk and

  7252. ** parsed, if that has not already been done, and returns an error if

  7253. ** any errors are encountered while loading the schema.

  7254. */

  7255. SQLITE_API int sqlite3_table_column_metadata(

  7256.   sqlite3 *db,                /* Connection handle */

  7257.   const char *zDbName,        /* Database name or NULL */

  7258.   const char *zTableName,     /* Table name */

  7259.   const char *zColumnName,    /* Column name */

  7260.   char const **pzDataType,    /* OUTPUT: Declared data type */

  7261.   char const **pzCollSeq,     /* OUTPUT: Collation sequence name */

  7262.   int *pNotNull,              /* OUTPUT: True if NOT NULL constraint exists */

  7263.   int *pPrimaryKey,           /* OUTPUT: True if column part of PK */

  7264.   int *pAutoinc               /* OUTPUT: True if column is auto-increment */

  7265. );

  7266. 

  7267. /*

  7268. ** CAPI3REF: Load An Extension

  7269. ** METHOD: sqlite3

  7270. **

  7271. ** ^This interface loads an SQLite extension library from the named file.

  7272. **

  7273. ** ^The sqlite3_load_extension() interface attempts to load an

  7274. ** [SQLite extension] library contained in the file zFile.  If

  7275. ** the file cannot be loaded directly, attempts are made to load

  7276. ** with various operating-system specific extensions added.

  7277. ** So for example, if "samplelib" cannot be loaded, then names like

  7278. ** "samplelib.so" or "samplelib.dylib" or "samplelib.dll" might

  7279. ** be tried also.

  7280. **

  7281. ** ^The entry point is zProc.

  7282. ** ^(zProc may be 0, in which case SQLite will try to come up with an

  7283. ** entry point name on its own.  It first tries "sqlite3_extension_init".

  7284. ** If that does not work, it constructs a name "sqlite3_X_init" where the

  7285. ** X is consists of the lower-case equivalent of all ASCII alphabetic

  7286. ** characters in the filename from the last "/" to the first following

  7287. ** "." and omitting any initial "lib".)^

  7288. ** ^The sqlite3_load_extension() interface returns

  7289. ** [SQLITE_OK] on success and [SQLITE_ERROR] if something goes wrong.

  7290. ** ^If an error occurs and pzErrMsg is not 0, then the

  7291. ** [sqlite3_load_extension()] interface shall attempt to

  7292. ** fill *pzErrMsg with error message text stored in memory

  7293. ** obtained from [sqlite3_malloc()]. The calling function

  7294. ** should free this memory by calling [sqlite3_free()].

  7295. **

  7296. ** ^Extension loading must be enabled using

  7297. ** [sqlite3_enable_load_extension()] or

  7298. ** [sqlite3_db_config](db,[SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION],1,NULL)

  7299. ** prior to calling this API,

  7300. ** otherwise an error will be returned.

  7301. **

  7302. ** <b>Security warning:</b> It is recommended that the 

  7303. ** [SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION] method be used to enable only this

  7304. ** interface.  The use of the [sqlite3_enable_load_extension()] interface

  7305. ** should be avoided.  This will keep the SQL function [load_extension()]

  7306. ** disabled and prevent SQL injections from giving attackers

  7307. ** access to extension loading capabilities.

  7308. **

  7309. ** See also the [load_extension() SQL function].

  7310. */

  7311. SQLITE_API int sqlite3_load_extension(

  7312.   sqlite3 *db,          /* Load the extension into this database connection */

  7313.   const char *zFile,    /* Name of the shared library containing extension */

  7314.   const char *zProc,    /* Entry point.  Derived from zFile if 0 */

  7315.   char **pzErrMsg       /* Put error message here if not 0 */

  7316. );

  7317. 

  7318. /*

  7319. ** CAPI3REF: Enable Or Disable Extension Loading

  7320. ** METHOD: sqlite3

  7321. **

  7322. ** ^So as not to open security holes in older applications that are

  7323. ** unprepared to deal with [extension loading], and as a means of disabling

  7324. ** [extension loading] while evaluating user-entered SQL, the following API

  7325. ** is provided to turn the [sqlite3_load_extension()] mechanism on and off.

  7326. **

  7327. ** ^Extension loading is off by default.

  7328. ** ^Call the sqlite3_enable_load_extension() routine with onoff==1

  7329. ** to turn extension loading on and call it with onoff==0 to turn

  7330. ** it back off again.

  7331. **

  7332. ** ^This interface enables or disables both the C-API

  7333. ** [sqlite3_load_extension()] and the SQL function [load_extension()].

  7334. ** ^(Use [sqlite3_db_config](db,[SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION],..)

  7335. ** to enable or disable only the C-API.)^

  7336. **

  7337. ** <b>Security warning:</b> It is recommended that extension loading

  7338. ** be disabled using the [SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION] method

  7339. ** rather than this interface, so the [load_extension()] SQL function

  7340. ** remains disabled. This will prevent SQL injections from giving attackers

  7341. ** access to extension loading capabilities.

  7342. */

  7343. SQLITE_API int sqlite3_enable_load_extension(sqlite3 *db, int onoff);

  7344. 

  7345. /*

  7346. ** CAPI3REF: Automatically Load Statically Linked Extensions

  7347. **

  7348. ** ^This interface causes the xEntryPoint() function to be invoked for

  7349. ** each new [database connection] that is created.  The idea here is that

  7350. ** xEntryPoint() is the entry point for a statically linked [SQLite extension]

  7351. ** that is to be automatically loaded into all new database connections.

  7352. **

  7353. ** ^(Even though the function prototype shows that xEntryPoint() takes

  7354. ** no arguments and returns void, SQLite invokes xEntryPoint() with three

  7355. ** arguments and expects an integer result as if the signature of the

  7356. ** entry point where as follows:

  7357. **

  7358. ** <blockquote><pre>

  7359. ** &nbsp;  int xEntryPoint(

  7360. ** &nbsp;    sqlite3 *db,

  7361. ** &nbsp;    const char **pzErrMsg,

  7362. ** &nbsp;    const struct sqlite3_api_routines *pThunk

  7363. ** &nbsp;  );

  7364. ** </pre></blockquote>)^

  7365. **

  7366. ** If the xEntryPoint routine encounters an error, it should make *pzErrMsg

  7367. ** point to an appropriate error message (obtained from [sqlite3_mprintf()])

  7368. ** and return an appropriate [error code].  ^SQLite ensures that *pzErrMsg

  7369. ** is NULL before calling the xEntryPoint().  ^SQLite will invoke

  7370. ** [sqlite3_free()] on *pzErrMsg after xEntryPoint() returns.  ^If any

  7371. ** xEntryPoint() returns an error, the [sqlite3_open()], [sqlite3_open16()],

  7372. ** or [sqlite3_open_v2()] call that provoked the xEntryPoint() will fail.

  7373. **

  7374. ** ^Calling sqlite3_auto_extension(X) with an entry point X that is already

  7375. ** on the list of automatic extensions is a harmless no-op. ^No entry point

  7376. ** will be called more than once for each database connection that is opened.

  7377. **

  7378. ** See also: [sqlite3_reset_auto_extension()]

  7379. ** and [sqlite3_cancel_auto_extension()]

  7380. */

  7381. SQLITE_API int sqlite3_auto_extension(void(*xEntryPoint)(void));

  7382. 

  7383. /*

  7384. ** CAPI3REF: Cancel Automatic Extension Loading

  7385. **

  7386. ** ^The [sqlite3_cancel_auto_extension(X)] interface unregisters the

  7387. ** initialization routine X that was registered using a prior call to

  7388. ** [sqlite3_auto_extension(X)].  ^The [sqlite3_cancel_auto_extension(X)]

  7389. ** routine returns 1 if initialization routine X was successfully 

  7390. ** unregistered and it returns 0 if X was not on the list of initialization

  7391. ** routines.

  7392. */

  7393. SQLITE_API int sqlite3_cancel_auto_extension(void(*xEntryPoint)(void));

  7394. 

  7395. /*

  7396. ** CAPI3REF: Reset Automatic Extension Loading

  7397. **

  7398. ** ^This interface disables all automatic extensions previously

  7399. ** registered using [sqlite3_auto_extension()].

  7400. */

  7401. SQLITE_API void sqlite3_reset_auto_extension(void);

  7402. 

  7403. /*

  7404. ** The interface to the virtual-table mechanism is currently considered

  7405. ** to be experimental.  The interface might change in incompatible ways.

  7406. ** If this is a problem for you, do not use the interface at this time.

  7407. **

  7408. ** When the virtual-table mechanism stabilizes, we will declare the

  7409. ** interface fixed, support it indefinitely, and remove this comment.

  7410. */

  7411. 

  7412. /*

  7413. ** Structures used by the virtual table interface

  7414. */

  7415. typedef struct sqlite3_vtab sqlite3_vtab;

  7416. typedef struct sqlite3_index_info sqlite3_index_info;

  7417. typedef struct sqlite3_vtab_cursor sqlite3_vtab_cursor;

  7418. typedef struct sqlite3_module sqlite3_module;

  7419. 

  7420. /*

  7421. ** CAPI3REF: Virtual Table Object

  7422. ** KEYWORDS: sqlite3_module {virtual table module}

  7423. **

  7424. ** This structure, sometimes called a "virtual table module", 

  7425. ** defines the implementation of a [virtual tables].  

  7426. ** This structure consists mostly of methods for the module.

  7427. **

  7428. ** ^A virtual table module is created by filling in a persistent

  7429. ** instance of this structure and passing a pointer to that instance

  7430. ** to [sqlite3_create_module()] or [sqlite3_create_module_v2()].

  7431. ** ^The registration remains valid until it is replaced by a different

  7432. ** module or until the [database connection] closes.  The content

  7433. ** of this structure must not change while it is registered with

  7434. ** any database connection.

  7435. */

  7436. struct sqlite3_module {

  7437.   int iVersion;

  7438.   int (*xCreate)(sqlite3*, void *pAux,

  7439.                int argc, const char *const*argv,

  7440.                sqlite3_vtab **ppVTab, char**);

  7441.   int (*xConnect)(sqlite3*, void *pAux,

  7442.                int argc, const char *const*argv,

  7443.                sqlite3_vtab **ppVTab, char**);

  7444.   int (*xBestIndex)(sqlite3_vtab *pVTab, sqlite3_index_info*);

  7445.   int (*xDisconnect)(sqlite3_vtab *pVTab);

  7446.   int (*xDestroy)(sqlite3_vtab *pVTab);

  7447.   int (*xOpen)(sqlite3_vtab *pVTab, sqlite3_vtab_cursor **ppCursor);

  7448.   int (*xClose)(sqlite3_vtab_cursor*);

  7449.   int (*xFilter)(sqlite3_vtab_cursor*, int idxNum, const char *idxStr,

  7450.                 int argc, sqlite3_value **argv);

  7451.   int (*xNext)(sqlite3_vtab_cursor*);

  7452.   int (*xEof)(sqlite3_vtab_cursor*);

  7453.   int (*xColumn)(sqlite3_vtab_cursor*, sqlite3_context*, int);

  7454.   int (*xRowid)(sqlite3_vtab_cursor*, sqlite3_int64 *pRowid);

  7455.   int (*xUpdate)(sqlite3_vtab *, int, sqlite3_value **, sqlite3_int64 *);

  7456.   int (*xBegin)(sqlite3_vtab *pVTab);

  7457.   int (*xSync)(sqlite3_vtab *pVTab);

  7458.   int (*xCommit)(sqlite3_vtab *pVTab);

  7459.   int (*xRollback)(sqlite3_vtab *pVTab);

  7460.   int (*xFindFunction)(sqlite3_vtab *pVtab, int nArg, const char *zName,

  7461.                        void (**pxFunc)(sqlite3_context*,int,sqlite3_value**),

  7462.                        void **ppArg);

  7463.   int (*xRename)(sqlite3_vtab *pVtab, const char *zNew);

  7464.   /* The methods above are in version 1 of the sqlite_module object. Those 

  7465.   ** below are for version 2 and greater. */

  7466.   int (*xSavepoint)(sqlite3_vtab *pVTab, int);

  7467.   int (*xRelease)(sqlite3_vtab *pVTab, int);

  7468.   int (*xRollbackTo)(sqlite3_vtab *pVTab, int);

  7469.   /* The methods above are in versions 1 and 2 of the sqlite_module object.

  7470.   ** Those below are for version 3 and greater. */

  7471.   int (*xShadowName)(const char*);

  7472. };

  7473. 

  7474. /*

  7475. ** CAPI3REF: Virtual Table Indexing Information

  7476. ** KEYWORDS: sqlite3_index_info

  7477. **

  7478. ** The sqlite3_index_info structure and its substructures is used as part

  7479. ** of the [virtual table] interface to

  7480. ** pass information into and receive the reply from the [xBestIndex]

  7481. ** method of a [virtual table module].  The fields under **Inputs** are the

  7482. ** inputs to xBestIndex and are read-only.  xBestIndex inserts its

  7483. ** results into the **Outputs** fields.

  7484. **

  7485. ** ^(The aConstraint[] array records WHERE clause constraints of the form:

  7486. **

  7487. ** <blockquote>column OP expr</blockquote>

  7488. **

  7489. ** where OP is =, &lt;, &lt;=, &gt;, or &gt;=.)^  ^(The particular operator is

  7490. ** stored in aConstraint[].op using one of the

  7491. ** [SQLITE_INDEX_CONSTRAINT_EQ | SQLITE_INDEX_CONSTRAINT_ values].)^

  7492. ** ^(The index of the column is stored in

  7493. ** aConstraint[].iColumn.)^  ^(aConstraint[].usable is TRUE if the

  7494. ** expr on the right-hand side can be evaluated (and thus the constraint

  7495. ** is usable) and false if it cannot.)^

  7496. **

  7497. ** ^The optimizer automatically inverts terms of the form "expr OP column"

  7498. ** and makes other simplifications to the WHERE clause in an attempt to

  7499. ** get as many WHERE clause terms into the form shown above as possible.

  7500. ** ^The aConstraint[] array only reports WHERE clause terms that are

  7501. ** relevant to the particular virtual table being queried.

  7502. **

  7503. ** ^Information about the ORDER BY clause is stored in aOrderBy[].

  7504. ** ^Each term of aOrderBy records a column of the ORDER BY clause.

  7505. **

  7506. ** The colUsed field indicates which columns of the virtual table may be

  7507. ** required by the current scan. Virtual table columns are numbered from

  7508. ** zero in the order in which they appear within the CREATE TABLE statement

  7509. ** passed to sqlite3_declare_vtab(). For the first 63 columns (columns 0-62),

  7510. ** the corresponding bit is set within the colUsed mask if the column may be

  7511. ** required by SQLite. If the table has at least 64 columns and any column

  7512. ** to the right of the first 63 is required, then bit 63 of colUsed is also

  7513. ** set. In other words, column iCol may be required if the expression

  7514. ** (colUsed & ((sqlite3_uint64)1 << (iCol>=63 ? 63 : iCol))) evaluates to 

  7515. ** non-zero.

  7516. **

  7517. ** The [xBestIndex] method must fill aConstraintUsage[] with information

  7518. ** about what parameters to pass to xFilter.  ^If argvIndex>0 then

  7519. ** the right-hand side of the corresponding aConstraint[] is evaluated

  7520. ** and becomes the argvIndex-th entry in argv.  ^(If aConstraintUsage[].omit

  7521. ** is true, then the constraint is assumed to be fully handled by the

  7522. ** virtual table and is not checked again by SQLite.)^

  7523. **

  7524. ** ^The idxNum and idxPtr values are recorded and passed into the

  7525. ** [xFilter] method.

  7526. ** ^[sqlite3_free()] is used to free idxPtr if and only if

  7527. ** needToFreeIdxPtr is true.

  7528. **

  7529. ** ^The orderByConsumed means that output from [xFilter]/[xNext] will occur in

  7530. ** the correct order to satisfy the ORDER BY clause so that no separate

  7531. ** sorting step is required.

  7532. **

  7533. ** ^The estimatedCost value is an estimate of the cost of a particular

  7534. ** strategy. A cost of N indicates that the cost of the strategy is similar

  7535. ** to a linear scan of an SQLite table with N rows. A cost of log(N) 

  7536. ** indicates that the expense of the operation is similar to that of a

  7537. ** binary search on a unique indexed field of an SQLite table with N rows.

  7538. **

  7539. ** ^The estimatedRows value is an estimate of the number of rows that

  7540. ** will be returned by the strategy.

  7541. **

  7542. ** The xBestIndex method may optionally populate the idxFlags field with a 

  7543. ** mask of SQLITE_INDEX_SCAN_* flags. Currently there is only one such flag -

  7544. ** SQLITE_INDEX_SCAN_UNIQUE. If the xBestIndex method sets this flag, SQLite

  7545. ** assumes that the strategy may visit at most one row. 

  7546. **

  7547. ** Additionally, if xBestIndex sets the SQLITE_INDEX_SCAN_UNIQUE flag, then

  7548. ** SQLite also assumes that if a call to the xUpdate() method is made as

  7549. ** part of the same statement to delete or update a virtual table row and the

  7550. ** implementation returns SQLITE_CONSTRAINT, then there is no need to rollback

  7551. ** any database changes. In other words, if the xUpdate() returns

  7552. ** SQLITE_CONSTRAINT, the database contents must be exactly as they were

  7553. ** before xUpdate was called. By contrast, if SQLITE_INDEX_SCAN_UNIQUE is not

  7554. ** set and xUpdate returns SQLITE_CONSTRAINT, any database changes made by

  7555. ** the xUpdate method are automatically rolled back by SQLite.

  7556. **

  7557. ** IMPORTANT: The estimatedRows field was added to the sqlite3_index_info

  7558. ** structure for SQLite [version 3.8.2] ([dateof:3.8.2]). 

  7559. ** If a virtual table extension is

  7560. ** used with an SQLite version earlier than 3.8.2, the results of attempting 

  7561. ** to read or write the estimatedRows field are undefined (but are likely 

  7562. ** to included crashing the application). The estimatedRows field should

  7563. ** therefore only be used if [sqlite3_libversion_number()] returns a

  7564. ** value greater than or equal to 3008002. Similarly, the idxFlags field

  7565. ** was added for [version 3.9.0] ([dateof:3.9.0]). 

  7566. ** It may therefore only be used if

  7567. ** sqlite3_libversion_number() returns a value greater than or equal to

  7568. ** 3009000.

  7569. */

  7570. struct sqlite3_index_info {

  7571.   /* Inputs */

  7572.   int nConstraint;           /* Number of entries in aConstraint */

  7573.   struct sqlite3_index_constraint {

  7574.      int iColumn;              /* Column constrained.  -1 for ROWID */

  7575.      unsigned char op;         /* Constraint operator */

  7576.      unsigned char usable;     /* True if this constraint is usable */

  7577.      int iTermOffset;          /* Used internally - xBestIndex should ignore */

  7578.   } *aConstraint;            /* Table of WHERE clause constraints */

  7579.   int nOrderBy;              /* Number of terms in the ORDER BY clause */

  7580.   struct sqlite3_index_orderby {

  7581.      int iColumn;              /* Column number */

  7582.      unsigned char desc;       /* True for DESC.  False for ASC. */

  7583.   } *aOrderBy;               /* The ORDER BY clause */

  7584.   /* Outputs */

  7585.   struct sqlite3_index_constraint_usage {

  7586.     int argvIndex;           /* if >0, constraint is part of argv to xFilter */

  7587.     unsigned char omit;      /* Do not code a test for this constraint */

  7588.   } *aConstraintUsage;

  7589.   int idxNum;                /* Number used to identify the index */

  7590.   char *idxStr;              /* String, possibly obtained from sqlite3_malloc */

  7591.   int needToFreeIdxStr;      /* Free idxStr using sqlite3_free() if true */

  7592.   int orderByConsumed;       /* True if output is already ordered */

  7593.   double estimatedCost;           /* Estimated cost of using this index */

  7594.   /* Fields below are only available in SQLite 3.8.2 and later */

  7595.   sqlite3_int64 estimatedRows;    /* Estimated number of rows returned */

  7596.   /* Fields below are only available in SQLite 3.9.0 and later */

  7597.   int idxFlags;              /* Mask of SQLITE_INDEX_SCAN_* flags */

  7598.   /* Fields below are only available in SQLite 3.10.0 and later */

  7599.   sqlite3_uint64 colUsed;    /* Input: Mask of columns used by statement */

  7600. };

  7601. 

  7602. /*

  7603. ** CAPI3REF: Virtual Table Scan Flags

  7604. **

  7605. ** Virtual table implementations are allowed to set the 

  7606. ** [sqlite3_index_info].idxFlags field to some combination of

  7607. ** these bits.

  7608. */

  7609. #define SQLITE_INDEX_SCAN_UNIQUE      1     /* Scan visits at most 1 row */

  7610. 

  7611. /*

  7612. ** CAPI3REF: Virtual Table Constraint Operator Codes

  7613. **

  7614. ** These macros defined the allowed values for the

  7615. ** [sqlite3_index_info].aConstraint[].op field.  Each value represents

  7616. ** an operator that is part of a constraint term in the wHERE clause of

  7617. ** a query that uses a [virtual table].

  7618. */

  7619. #define SQLITE_INDEX_CONSTRAINT_EQ         2

  7620. #define SQLITE_INDEX_CONSTRAINT_GT         4

  7621. #define SQLITE_INDEX_CONSTRAINT_LE         8

  7622. #define SQLITE_INDEX_CONSTRAINT_LT        16

  7623. #define SQLITE_INDEX_CONSTRAINT_GE        32

  7624. #define SQLITE_INDEX_CONSTRAINT_MATCH     64

  7625. #define SQLITE_INDEX_CONSTRAINT_LIKE      65

  7626. #define SQLITE_INDEX_CONSTRAINT_GLOB      66

  7627. #define SQLITE_INDEX_CONSTRAINT_REGEXP    67

  7628. #define SQLITE_INDEX_CONSTRAINT_NE        68

  7629. #define SQLITE_INDEX_CONSTRAINT_ISNOT     69

  7630. #define SQLITE_INDEX_CONSTRAINT_ISNOTNULL 70

  7631. #define SQLITE_INDEX_CONSTRAINT_ISNULL    71

  7632. #define SQLITE_INDEX_CONSTRAINT_IS        72

  7633. #define SQLITE_INDEX_CONSTRAINT_FUNCTION 150

  7634. 

  7635. /*

  7636. ** CAPI3REF: Register A Virtual Table Implementation

  7637. ** METHOD: sqlite3

  7638. **

  7639. ** ^These routines are used to register a new [virtual table module] name.

  7640. ** ^Module names must be registered before

  7641. ** creating a new [virtual table] using the module and before using a

  7642. ** preexisting [virtual table] for the module.

  7643. **

  7644. ** ^The module name is registered on the [database connection] specified

  7645. ** by the first parameter.  ^The name of the module is given by the 

  7646. ** second parameter.  ^The third parameter is a pointer to

  7647. ** the implementation of the [virtual table module].   ^The fourth

  7648. ** parameter is an arbitrary client data pointer that is passed through

  7649. ** into the [xCreate] and [xConnect] methods of the virtual table module

  7650. ** when a new virtual table is be being created or reinitialized.

  7651. **

  7652. ** ^The sqlite3_create_module_v2() interface has a fifth parameter which

  7653. ** is a pointer to a destructor for the pClientData.  ^SQLite will

  7654. ** invoke the destructor function (if it is not NULL) when SQLite

  7655. ** no longer needs the pClientData pointer.  ^The destructor will also

  7656. ** be invoked if the call to sqlite3_create_module_v2() fails.

  7657. ** ^The sqlite3_create_module()

  7658. ** interface is equivalent to sqlite3_create_module_v2() with a NULL

  7659. ** destructor.

  7660. */

  7661. SQLITE_API int sqlite3_create_module(

  7662.   sqlite3 *db,               /* SQLite connection to register module with */

  7663.   const char *zName,         /* Name of the module */

  7664.   const sqlite3_module *p,   /* Methods for the module */

  7665.   void *pClientData          /* Client data for xCreate/xConnect */

  7666. );

  7667. SQLITE_API int sqlite3_create_module_v2(

  7668.   sqlite3 *db,               /* SQLite connection to register module with */

  7669.   const char *zName,         /* Name of the module */

  7670.   const sqlite3_module *p,   /* Methods for the module */

  7671.   void *pClientData,         /* Client data for xCreate/xConnect */

  7672.   void(*xDestroy)(void*)     /* Module destructor function */

  7673. );

  7674. 

  7675. /*

  7676. ** CAPI3REF: Virtual Table Instance Object

  7677. ** KEYWORDS: sqlite3_vtab

  7678. **

  7679. ** Every [virtual table module] implementation uses a subclass

  7680. ** of this object to describe a particular instance

  7681. ** of the [virtual table].  Each subclass will

  7682. ** be tailored to the specific needs of the module implementation.

  7683. ** The purpose of this superclass is to define certain fields that are

  7684. ** common to all module implementations.

  7685. **

  7686. ** ^Virtual tables methods can set an error message by assigning a

  7687. ** string obtained from [sqlite3_mprintf()] to zErrMsg.  The method should

  7688. ** take care that any prior string is freed by a call to [sqlite3_free()]

  7689. ** prior to assigning a new string to zErrMsg.  ^After the error message

  7690. ** is delivered up to the client application, the string will be automatically

  7691. ** freed by sqlite3_free() and the zErrMsg field will be zeroed.

  7692. */

  7693. struct sqlite3_vtab {

  7694.   const sqlite3_module *pModule;  /* The module for this virtual table */

  7695.   int nRef;                       /* Number of open cursors */

  7696.   char *zErrMsg;                  /* Error message from sqlite3_mprintf() */

  7697.   /* Virtual table implementations will typically add additional fields */

  7698. };

  7699. 

  7700. /*

  7701. ** CAPI3REF: Virtual Table Cursor Object

  7702. ** KEYWORDS: sqlite3_vtab_cursor {virtual table cursor}

  7703. **

  7704. ** Every [virtual table module] implementation uses a subclass of the

  7705. ** following structure to describe cursors that point into the

  7706. ** [virtual table] and are used

  7707. ** to loop through the virtual table.  Cursors are created using the

  7708. ** [sqlite3_module.xOpen | xOpen] method of the module and are destroyed

  7709. ** by the [sqlite3_module.xClose | xClose] method.  Cursors are used

  7710. ** by the [xFilter], [xNext], [xEof], [xColumn], and [xRowid] methods

  7711. ** of the module.  Each module implementation will define

  7712. ** the content of a cursor structure to suit its own needs.

  7713. **

  7714. ** This superclass exists in order to define fields of the cursor that

  7715. ** are common to all implementations.

  7716. */

  7717. struct sqlite3_vtab_cursor {

  7718.   sqlite3_vtab *pVtab;      /* Virtual table of this cursor */

  7719.   /* Virtual table implementations will typically add additional fields */

  7720. };

  7721. 

  7722. /*

  7723. ** CAPI3REF: Declare The Schema Of A Virtual Table

  7724. **

  7725. ** ^The [xCreate] and [xConnect] methods of a

  7726. ** [virtual table module] call this interface

  7727. ** to declare the format (the names and datatypes of the columns) of

  7728. ** the virtual tables they implement.

  7729. */

  7730. SQLITE_API int sqlite3_declare_vtab(sqlite3*, const char *zSQL);

  7731. 

  7732. /*

  7733. ** CAPI3REF: Overload A Function For A Virtual Table

  7734. ** METHOD: sqlite3

  7735. **

  7736. ** ^(Virtual tables can provide alternative implementations of functions

  7737. ** using the [xFindFunction] method of the [virtual table module].  

  7738. ** But global versions of those functions

  7739. ** must exist in order to be overloaded.)^

  7740. **

  7741. ** ^(This API makes sure a global version of a function with a particular

  7742. ** name and number of parameters exists.  If no such function exists

  7743. ** before this API is called, a new function is created.)^  ^The implementation

  7744. ** of the new function always causes an exception to be thrown.  So

  7745. ** the new function is not good for anything by itself.  Its only

  7746. ** purpose is to be a placeholder function that can be overloaded

  7747. ** by a [virtual table].

  7748. */

  7749. SQLITE_API int sqlite3_overload_function(sqlite3*, const char *zFuncName, int nArg);

  7750. 

  7751. /*

  7752. ** The interface to the virtual-table mechanism defined above (back up

  7753. ** to a comment remarkably similar to this one) is currently considered

  7754. ** to be experimental.  The interface might change in incompatible ways.

  7755. ** If this is a problem for you, do not use the interface at this time.

  7756. **

  7757. ** When the virtual-table mechanism stabilizes, we will declare the

  7758. ** interface fixed, support it indefinitely, and remove this comment.

  7759. */

  7760. 

  7761. /*

  7762. ** CAPI3REF: A Handle To An Open BLOB

  7763. ** KEYWORDS: {BLOB handle} {BLOB handles}

  7764. **

  7765. ** An instance of this object represents an open BLOB on which

  7766. ** [sqlite3_blob_open | incremental BLOB I/O] can be performed.

  7767. ** ^Objects of this type are created by [sqlite3_blob_open()]

  7768. ** and destroyed by [sqlite3_blob_close()].

  7769. ** ^The [sqlite3_blob_read()] and [sqlite3_blob_write()] interfaces

  7770. ** can be used to read or write small subsections of the BLOB.

  7771. ** ^The [sqlite3_blob_bytes()] interface returns the size of the BLOB in bytes.

  7772. */

  7773. typedef struct sqlite3_blob sqlite3_blob;

  7774. 

  7775. /*

  7776. ** CAPI3REF: Open A BLOB For Incremental I/O

  7777. ** METHOD: sqlite3

  7778. ** CONSTRUCTOR: sqlite3_blob

  7779. **

  7780. ** ^(This interfaces opens a [BLOB handle | handle] to the BLOB located

  7781. ** in row iRow, column zColumn, table zTable in database zDb;

  7782. ** in other words, the same BLOB that would be selected by:

  7783. **

  7784. ** <pre>

  7785. **     SELECT zColumn FROM zDb.zTable WHERE [rowid] = iRow;

  7786. ** </pre>)^

  7787. **

  7788. ** ^(Parameter zDb is not the filename that contains the database, but 

  7789. ** rather the symbolic name of the database. For attached databases, this is

  7790. ** the name that appears after the AS keyword in the [ATTACH] statement.

  7791. ** For the main database file, the database name is "main". For TEMP

  7792. ** tables, the database name is "temp".)^

  7793. **

  7794. ** ^If the flags parameter is non-zero, then the BLOB is opened for read

  7795. ** and write access. ^If the flags parameter is zero, the BLOB is opened for

  7796. ** read-only access.

  7797. **

  7798. ** ^(On success, [SQLITE_OK] is returned and the new [BLOB handle] is stored

  7799. ** in *ppBlob. Otherwise an [error code] is returned and, unless the error

  7800. ** code is SQLITE_MISUSE, *ppBlob is set to NULL.)^ ^This means that, provided

  7801. ** the API is not misused, it is always safe to call [sqlite3_blob_close()] 

  7802. ** on *ppBlob after this function it returns.

  7803. **

  7804. ** This function fails with SQLITE_ERROR if any of the following are true:

  7805. ** <ul>

  7806. **   <li> ^(Database zDb does not exist)^, 

  7807. **   <li> ^(Table zTable does not exist within database zDb)^, 

  7808. **   <li> ^(Table zTable is a WITHOUT ROWID table)^, 

  7809. **   <li> ^(Column zColumn does not exist)^,

  7810. **   <li> ^(Row iRow is not present in the table)^,

  7811. **   <li> ^(The specified column of row iRow contains a value that is not

  7812. **         a TEXT or BLOB value)^,

  7813. **   <li> ^(Column zColumn is part of an index, PRIMARY KEY or UNIQUE 

  7814. **         constraint and the blob is being opened for read/write access)^,

  7815. **   <li> ^([foreign key constraints | Foreign key constraints] are enabled, 

  7816. **         column zColumn is part of a [child key] definition and the blob is

  7817. **         being opened for read/write access)^.

  7818. ** </ul>

  7819. **

  7820. ** ^Unless it returns SQLITE_MISUSE, this function sets the 

  7821. ** [database connection] error code and message accessible via 

  7822. ** [sqlite3_errcode()] and [sqlite3_errmsg()] and related functions. 

  7823. **

  7824. ** A BLOB referenced by sqlite3_blob_open() may be read using the

  7825. ** [sqlite3_blob_read()] interface and modified by using

  7826. ** [sqlite3_blob_write()].  The [BLOB handle] can be moved to a

  7827. ** different row of the same table using the [sqlite3_blob_reopen()]

  7828. ** interface.  However, the column, table, or database of a [BLOB handle]

  7829. ** cannot be changed after the [BLOB handle] is opened.

  7830. **

  7831. ** ^(If the row that a BLOB handle points to is modified by an

  7832. ** [UPDATE], [DELETE], or by [ON CONFLICT] side-effects

  7833. ** then the BLOB handle is marked as "expired".

  7834. ** This is true if any column of the row is changed, even a column

  7835. ** other than the one the BLOB handle is open on.)^

  7836. ** ^Calls to [sqlite3_blob_read()] and [sqlite3_blob_write()] for

  7837. ** an expired BLOB handle fail with a return code of [SQLITE_ABORT].

  7838. ** ^(Changes written into a BLOB prior to the BLOB expiring are not

  7839. ** rolled back by the expiration of the BLOB.  Such changes will eventually

  7840. ** commit if the transaction continues to completion.)^

  7841. **

  7842. ** ^Use the [sqlite3_blob_bytes()] interface to determine the size of

  7843. ** the opened blob.  ^The size of a blob may not be changed by this

  7844. ** interface.  Use the [UPDATE] SQL command to change the size of a

  7845. ** blob.

  7846. **

  7847. ** ^The [sqlite3_bind_zeroblob()] and [sqlite3_result_zeroblob()] interfaces

  7848. ** and the built-in [zeroblob] SQL function may be used to create a 

  7849. ** zero-filled blob to read or write using the incremental-blob interface.

  7850. **

  7851. ** To avoid a resource leak, every open [BLOB handle] should eventually

  7852. ** be released by a call to [sqlite3_blob_close()].

  7853. **

  7854. ** See also: [sqlite3_blob_close()],

  7855. ** [sqlite3_blob_reopen()], [sqlite3_blob_read()],

  7856. ** [sqlite3_blob_bytes()], [sqlite3_blob_write()].

  7857. */

  7858. SQLITE_API int sqlite3_blob_open(

  7859.   sqlite3*,

  7860.   const char *zDb,

  7861.   const char *zTable,

  7862.   const char *zColumn,

  7863.   sqlite3_int64 iRow,

  7864.   int flags,

  7865.   sqlite3_blob **ppBlob

  7866. );

  7867. 

  7868. /*

  7869. ** CAPI3REF: Move a BLOB Handle to a New Row

  7870. ** METHOD: sqlite3_blob

  7871. **

  7872. ** ^This function is used to move an existing [BLOB handle] so that it points

  7873. ** to a different row of the same database table. ^The new row is identified

  7874. ** by the rowid value passed as the second argument. Only the row can be

  7875. ** changed. ^The database, table and column on which the blob handle is open

  7876. ** remain the same. Moving an existing [BLOB handle] to a new row is

  7877. ** faster than closing the existing handle and opening a new one.

  7878. **

  7879. ** ^(The new row must meet the same criteria as for [sqlite3_blob_open()] -

  7880. ** it must exist and there must be either a blob or text value stored in

  7881. ** the nominated column.)^ ^If the new row is not present in the table, or if

  7882. ** it does not contain a blob or text value, or if another error occurs, an

  7883. ** SQLite error code is returned and the blob handle is considered aborted.

  7884. ** ^All subsequent calls to [sqlite3_blob_read()], [sqlite3_blob_write()] or

  7885. ** [sqlite3_blob_reopen()] on an aborted blob handle immediately return

  7886. ** SQLITE_ABORT. ^Calling [sqlite3_blob_bytes()] on an aborted blob handle

  7887. ** always returns zero.

  7888. **

  7889. ** ^This function sets the database handle error code and message.

  7890. */

  7891. SQLITE_API int sqlite3_blob_reopen(sqlite3_blob *, sqlite3_int64);

  7892. 

  7893. /*

  7894. ** CAPI3REF: Close A BLOB Handle

  7895. ** DESTRUCTOR: sqlite3_blob

  7896. **

  7897. ** ^This function closes an open [BLOB handle]. ^(The BLOB handle is closed

  7898. ** unconditionally.  Even if this routine returns an error code, the 

  7899. ** handle is still closed.)^

  7900. **

  7901. ** ^If the blob handle being closed was opened for read-write access, and if

  7902. ** the database is in auto-commit mode and there are no other open read-write

  7903. ** blob handles or active write statements, the current transaction is

  7904. ** committed. ^If an error occurs while committing the transaction, an error

  7905. ** code is returned and the transaction rolled back.

  7906. **

  7907. ** Calling this function with an argument that is not a NULL pointer or an

  7908. ** open blob handle results in undefined behaviour. ^Calling this routine 

  7909. ** with a null pointer (such as would be returned by a failed call to 

  7910. ** [sqlite3_blob_open()]) is a harmless no-op. ^Otherwise, if this function

  7911. ** is passed a valid open blob handle, the values returned by the 

  7912. ** sqlite3_errcode() and sqlite3_errmsg() functions are set before returning.

  7913. */

  7914. SQLITE_API int sqlite3_blob_close(sqlite3_blob *);

  7915. 

  7916. /*

  7917. ** CAPI3REF: Return The Size Of An Open BLOB

  7918. ** METHOD: sqlite3_blob

  7919. **

  7920. ** ^Returns the size in bytes of the BLOB accessible via the 

  7921. ** successfully opened [BLOB handle] in its only argument.  ^The

  7922. ** incremental blob I/O routines can only read or overwriting existing

  7923. ** blob content; they cannot change the size of a blob.

  7924. **

  7925. ** This routine only works on a [BLOB handle] which has been created

  7926. ** by a prior successful call to [sqlite3_blob_open()] and which has not

  7927. ** been closed by [sqlite3_blob_close()].  Passing any other pointer in

  7928. ** to this routine results in undefined and probably undesirable behavior.

  7929. */

  7930. SQLITE_API int sqlite3_blob_bytes(sqlite3_blob *);

  7931. 

  7932. /*

  7933. ** CAPI3REF: Read Data From A BLOB Incrementally

  7934. ** METHOD: sqlite3_blob

  7935. **

  7936. ** ^(This function is used to read data from an open [BLOB handle] into a

  7937. ** caller-supplied buffer. N bytes of data are copied into buffer Z

  7938. ** from the open BLOB, starting at offset iOffset.)^

  7939. **

  7940. ** ^If offset iOffset is less than N bytes from the end of the BLOB,

  7941. ** [SQLITE_ERROR] is returned and no data is read.  ^If N or iOffset is

  7942. ** less than zero, [SQLITE_ERROR] is returned and no data is read.

  7943. ** ^The size of the blob (and hence the maximum value of N+iOffset)

  7944. ** can be determined using the [sqlite3_blob_bytes()] interface.

  7945. **

  7946. ** ^An attempt to read from an expired [BLOB handle] fails with an

  7947. ** error code of [SQLITE_ABORT].

  7948. **

  7949. ** ^(On success, sqlite3_blob_read() returns SQLITE_OK.

  7950. ** Otherwise, an [error code] or an [extended error code] is returned.)^

  7951. **

  7952. ** This routine only works on a [BLOB handle] which has been created

  7953. ** by a prior successful call to [sqlite3_blob_open()] and which has not

  7954. ** been closed by [sqlite3_blob_close()].  Passing any other pointer in

  7955. ** to this routine results in undefined and probably undesirable behavior.

  7956. **

  7957. ** See also: [sqlite3_blob_write()].

  7958. */

  7959. SQLITE_API int sqlite3_blob_read(sqlite3_blob *, void *Z, int N, int iOffset);

  7960. 

  7961. /*

  7962. ** CAPI3REF: Write Data Into A BLOB Incrementally

  7963. ** METHOD: sqlite3_blob

  7964. **

  7965. ** ^(This function is used to write data into an open [BLOB handle] from a

  7966. ** caller-supplied buffer. N bytes of data are copied from the buffer Z

  7967. ** into the open BLOB, starting at offset iOffset.)^

  7968. **

  7969. ** ^(On success, sqlite3_blob_write() returns SQLITE_OK.

  7970. ** Otherwise, an  [error code] or an [extended error code] is returned.)^

  7971. ** ^Unless SQLITE_MISUSE is returned, this function sets the 

  7972. ** [database connection] error code and message accessible via 

  7973. ** [sqlite3_errcode()] and [sqlite3_errmsg()] and related functions. 

  7974. **

  7975. ** ^If the [BLOB handle] passed as the first argument was not opened for

  7976. ** writing (the flags parameter to [sqlite3_blob_open()] was zero),

  7977. ** this function returns [SQLITE_READONLY].

  7978. **

  7979. ** This function may only modify the contents of the BLOB; it is

  7980. ** not possible to increase the size of a BLOB using this API.

  7981. ** ^If offset iOffset is less than N bytes from the end of the BLOB,

  7982. ** [SQLITE_ERROR] is returned and no data is written. The size of the 

  7983. ** BLOB (and hence the maximum value of N+iOffset) can be determined 

  7984. ** using the [sqlite3_blob_bytes()] interface. ^If N or iOffset are less 

  7985. ** than zero [SQLITE_ERROR] is returned and no data is written.

  7986. **

  7987. ** ^An attempt to write to an expired [BLOB handle] fails with an

  7988. ** error code of [SQLITE_ABORT].  ^Writes to the BLOB that occurred

  7989. ** before the [BLOB handle] expired are not rolled back by the

  7990. ** expiration of the handle, though of course those changes might

  7991. ** have been overwritten by the statement that expired the BLOB handle

  7992. ** or by other independent statements.

  7993. **

  7994. ** This routine only works on a [BLOB handle] which has been created

  7995. ** by a prior successful call to [sqlite3_blob_open()] and which has not

  7996. ** been closed by [sqlite3_blob_close()].  Passing any other pointer in

  7997. ** to this routine results in undefined and probably undesirable behavior.

  7998. **

  7999. ** See also: [sqlite3_blob_read()].

  8000. */

  8001. SQLITE_API int sqlite3_blob_write(sqlite3_blob *, const void *z, int n, int iOffset);

  8002. 

  8003. /*

  8004. ** CAPI3REF: Virtual File System Objects

  8005. **

  8006. ** A virtual filesystem (VFS) is an [sqlite3_vfs] object

  8007. ** that SQLite uses to interact

  8008. ** with the underlying operating system.  Most SQLite builds come with a

  8009. ** single default VFS that is appropriate for the host computer.

  8010. ** New VFSes can be registered and existing VFSes can be unregistered.

  8011. ** The following interfaces are provided.

  8012. **

  8013. ** ^The sqlite3_vfs_find() interface returns a pointer to a VFS given its name.

  8014. ** ^Names are case sensitive.

  8015. ** ^Names are zero-terminated UTF-8 strings.

  8016. ** ^If there is no match, a NULL pointer is returned.

  8017. ** ^If zVfsName is NULL then the default VFS is returned.

  8018. **

  8019. ** ^New VFSes are registered with sqlite3_vfs_register().

  8020. ** ^Each new VFS becomes the default VFS if the makeDflt flag is set.

  8021. ** ^The same VFS can be registered multiple times without injury.

  8022. ** ^To make an existing VFS into the default VFS, register it again

  8023. ** with the makeDflt flag set.  If two different VFSes with the

  8024. ** same name are registered, the behavior is undefined.  If a

  8025. ** VFS is registered with a name that is NULL or an empty string,

  8026. ** then the behavior is undefined.

  8027. **

  8028. ** ^Unregister a VFS with the sqlite3_vfs_unregister() interface.

  8029. ** ^(If the default VFS is unregistered, another VFS is chosen as

  8030. ** the default.  The choice for the new VFS is arbitrary.)^

  8031. */

  8032. SQLITE_API sqlite3_vfs *sqlite3_vfs_find(const char *zVfsName);

  8033. SQLITE_API int sqlite3_vfs_register(sqlite3_vfs*, int makeDflt);

  8034. SQLITE_API int sqlite3_vfs_unregister(sqlite3_vfs*);

  8035. 

  8036. /*

  8037. ** CAPI3REF: Mutexes

  8038. **

  8039. ** The SQLite core uses these routines for thread

  8040. ** synchronization. Though they are intended for internal

  8041. ** use by SQLite, code that links against SQLite is

  8042. ** permitted to use any of these routines.

  8043. **

  8044. ** The SQLite source code contains multiple implementations

  8045. ** of these mutex routines.  An appropriate implementation

  8046. ** is selected automatically at compile-time.  The following

  8047. ** implementations are available in the SQLite core:

  8048. **

  8049. ** <ul>

  8050. ** <li>   SQLITE_MUTEX_PTHREADS

  8051. ** <li>   SQLITE_MUTEX_W32

  8052. ** <li>   SQLITE_MUTEX_NOOP

  8053. ** </ul>

  8054. **

  8055. ** The SQLITE_MUTEX_NOOP implementation is a set of routines

  8056. ** that does no real locking and is appropriate for use in

  8057. ** a single-threaded application.  The SQLITE_MUTEX_PTHREADS and

  8058. ** SQLITE_MUTEX_W32 implementations are appropriate for use on Unix

  8059. ** and Windows.

  8060. **

  8061. ** If SQLite is compiled with the SQLITE_MUTEX_APPDEF preprocessor

  8062. ** macro defined (with "-DSQLITE_MUTEX_APPDEF=1"), then no mutex

  8063. ** implementation is included with the library. In this case the

  8064. ** application must supply a custom mutex implementation using the

  8065. ** [SQLITE_CONFIG_MUTEX] option of the sqlite3_config() function

  8066. ** before calling sqlite3_initialize() or any other public sqlite3_

  8067. ** function that calls sqlite3_initialize().

  8068. **

  8069. ** ^The sqlite3_mutex_alloc() routine allocates a new

  8070. ** mutex and returns a pointer to it. ^The sqlite3_mutex_alloc()

  8071. ** routine returns NULL if it is unable to allocate the requested

  8072. ** mutex.  The argument to sqlite3_mutex_alloc() must one of these

  8073. ** integer constants:

  8074. **

  8075. ** <ul>

  8076. ** <li>  SQLITE_MUTEX_FAST

  8077. ** <li>  SQLITE_MUTEX_RECURSIVE

  8078. ** <li>  SQLITE_MUTEX_STATIC_MASTER

  8079. ** <li>  SQLITE_MUTEX_STATIC_MEM

  8080. ** <li>  SQLITE_MUTEX_STATIC_OPEN

  8081. ** <li>  SQLITE_MUTEX_STATIC_PRNG

  8082. ** <li>  SQLITE_MUTEX_STATIC_LRU

  8083. ** <li>  SQLITE_MUTEX_STATIC_PMEM

  8084. ** <li>  SQLITE_MUTEX_STATIC_APP1

  8085. ** <li>  SQLITE_MUTEX_STATIC_APP2

  8086. ** <li>  SQLITE_MUTEX_STATIC_APP3

  8087. ** <li>  SQLITE_MUTEX_STATIC_VFS1

  8088. ** <li>  SQLITE_MUTEX_STATIC_VFS2

  8089. ** <li>  SQLITE_MUTEX_STATIC_VFS3

  8090. ** </ul>

  8091. **

  8092. ** ^The first two constants (SQLITE_MUTEX_FAST and SQLITE_MUTEX_RECURSIVE)

  8093. ** cause sqlite3_mutex_alloc() to create

  8094. ** a new mutex.  ^The new mutex is recursive when SQLITE_MUTEX_RECURSIVE

  8095. ** is used but not necessarily so when SQLITE_MUTEX_FAST is used.

  8096. ** The mutex implementation does not need to make a distinction

  8097. ** between SQLITE_MUTEX_RECURSIVE and SQLITE_MUTEX_FAST if it does

  8098. ** not want to.  SQLite will only request a recursive mutex in

  8099. ** cases where it really needs one.  If a faster non-recursive mutex

  8100. ** implementation is available on the host platform, the mutex subsystem

  8101. ** might return such a mutex in response to SQLITE_MUTEX_FAST.

  8102. **

  8103. ** ^The other allowed parameters to sqlite3_mutex_alloc() (anything other

  8104. ** than SQLITE_MUTEX_FAST and SQLITE_MUTEX_RECURSIVE) each return

  8105. ** a pointer to a static preexisting mutex.  ^Nine static mutexes are

  8106. ** used by the current version of SQLite.  Future versions of SQLite

  8107. ** may add additional static mutexes.  Static mutexes are for internal

  8108. ** use by SQLite only.  Applications that use SQLite mutexes should

  8109. ** use only the dynamic mutexes returned by SQLITE_MUTEX_FAST or

  8110. ** SQLITE_MUTEX_RECURSIVE.

  8111. **

  8112. ** ^Note that if one of the dynamic mutex parameters (SQLITE_MUTEX_FAST

  8113. ** or SQLITE_MUTEX_RECURSIVE) is used then sqlite3_mutex_alloc()

  8114. ** returns a different mutex on every call.  ^For the static

  8115. ** mutex types, the same mutex is returned on every call that has

  8116. ** the same type number.

  8117. **

  8118. ** ^The sqlite3_mutex_free() routine deallocates a previously

  8119. ** allocated dynamic mutex.  Attempting to deallocate a static

  8120. ** mutex results in undefined behavior.

  8121. **

  8122. ** ^The sqlite3_mutex_enter() and sqlite3_mutex_try() routines attempt

  8123. ** to enter a mutex.  ^If another thread is already within the mutex,

  8124. ** sqlite3_mutex_enter() will block and sqlite3_mutex_try() will return

  8125. ** SQLITE_BUSY.  ^The sqlite3_mutex_try() interface returns [SQLITE_OK]

  8126. ** upon successful entry.  ^(Mutexes created using

  8127. ** SQLITE_MUTEX_RECURSIVE can be entered multiple times by the same thread.

  8128. ** In such cases, the

  8129. ** mutex must be exited an equal number of times before another thread

  8130. ** can enter.)^  If the same thread tries to enter any mutex other

  8131. ** than an SQLITE_MUTEX_RECURSIVE more than once, the behavior is undefined.

  8132. **

  8133. ** ^(Some systems (for example, Windows 95) do not support the operation

  8134. ** implemented by sqlite3_mutex_try().  On those systems, sqlite3_mutex_try()

  8135. ** will always return SQLITE_BUSY. The SQLite core only ever uses

  8136. ** sqlite3_mutex_try() as an optimization so this is acceptable 

  8137. ** behavior.)^

  8138. **

  8139. ** ^The sqlite3_mutex_leave() routine exits a mutex that was

  8140. ** previously entered by the same thread.   The behavior

  8141. ** is undefined if the mutex is not currently entered by the

  8142. ** calling thread or is not currently allocated.

  8143. **

  8144. ** ^If the argument to sqlite3_mutex_enter(), sqlite3_mutex_try(), or

  8145. ** sqlite3_mutex_leave() is a NULL pointer, then all three routines

  8146. ** behave as no-ops.

  8147. **

  8148. ** See also: [sqlite3_mutex_held()] and [sqlite3_mutex_notheld()].

  8149. */

  8150. SQLITE_API sqlite3_mutex *sqlite3_mutex_alloc(int);

  8151. SQLITE_API void sqlite3_mutex_free(sqlite3_mutex*);

  8152. SQLITE_API void sqlite3_mutex_enter(sqlite3_mutex*);

  8153. SQLITE_API int sqlite3_mutex_try(sqlite3_mutex*);

  8154. SQLITE_API void sqlite3_mutex_leave(sqlite3_mutex*);

  8155. 

  8156. /*

  8157. ** CAPI3REF: Mutex Methods Object

  8158. **

  8159. ** An instance of this structure defines the low-level routines

  8160. ** used to allocate and use mutexes.

  8161. **

  8162. ** Usually, the default mutex implementations provided by SQLite are

  8163. ** sufficient, however the application has the option of substituting a custom

  8164. ** implementation for specialized deployments or systems for which SQLite

  8165. ** does not provide a suitable implementation. In this case, the application

  8166. ** creates and populates an instance of this structure to pass

  8167. ** to sqlite3_config() along with the [SQLITE_CONFIG_MUTEX] option.

  8168. ** Additionally, an instance of this structure can be used as an

  8169. ** output variable when querying the system for the current mutex

  8170. ** implementation, using the [SQLITE_CONFIG_GETMUTEX] option.

  8171. **

  8172. ** ^The xMutexInit method defined by this structure is invoked as

  8173. ** part of system initialization by the sqlite3_initialize() function.

  8174. ** ^The xMutexInit routine is called by SQLite exactly once for each

  8175. ** effective call to [sqlite3_initialize()].

  8176. **

  8177. ** ^The xMutexEnd method defined by this structure is invoked as

  8178. ** part of system shutdown by the sqlite3_shutdown() function. The

  8179. ** implementation of this method is expected to release all outstanding

  8180. ** resources obtained by the mutex methods implementation, especially

  8181. ** those obtained by the xMutexInit method.  ^The xMutexEnd()

  8182. ** interface is invoked exactly once for each call to [sqlite3_shutdown()].

  8183. **

  8184. ** ^(The remaining seven methods defined by this structure (xMutexAlloc,

  8185. ** xMutexFree, xMutexEnter, xMutexTry, xMutexLeave, xMutexHeld and

  8186. ** xMutexNotheld) implement the following interfaces (respectively):

  8187. **

  8188. ** <ul>

  8189. **   <li>  [sqlite3_mutex_alloc()] </li>

  8190. **   <li>  [sqlite3_mutex_free()] </li>

  8191. **   <li>  [sqlite3_mutex_enter()] </li>

  8192. **   <li>  [sqlite3_mutex_try()] </li>

  8193. **   <li>  [sqlite3_mutex_leave()] </li>

  8194. **   <li>  [sqlite3_mutex_held()] </li>

  8195. **   <li>  [sqlite3_mutex_notheld()] </li>

  8196. ** </ul>)^

  8197. **

  8198. ** The only difference is that the public sqlite3_XXX functions enumerated

  8199. ** above silently ignore any invocations that pass a NULL pointer instead

  8200. ** of a valid mutex handle. The implementations of the methods defined

  8201. ** by this structure are not required to handle this case, the results

  8202. ** of passing a NULL pointer instead of a valid mutex handle are undefined

  8203. ** (i.e. it is acceptable to provide an implementation that segfaults if

  8204. ** it is passed a NULL pointer).

  8205. **

  8206. ** The xMutexInit() method must be threadsafe.  It must be harmless to

  8207. ** invoke xMutexInit() multiple times within the same process and without

  8208. ** intervening calls to xMutexEnd().  Second and subsequent calls to

  8209. ** xMutexInit() must be no-ops.

  8210. **

  8211. ** xMutexInit() must not use SQLite memory allocation ([sqlite3_malloc()]

  8212. ** and its associates).  Similarly, xMutexAlloc() must not use SQLite memory

  8213. ** allocation for a static mutex.  ^However xMutexAlloc() may use SQLite

  8214. ** memory allocation for a fast or recursive mutex.

  8215. **

  8216. ** ^SQLite will invoke the xMutexEnd() method when [sqlite3_shutdown()] is

  8217. ** called, but only if the prior call to xMutexInit returned SQLITE_OK.

  8218. ** If xMutexInit fails in any way, it is expected to clean up after itself

  8219. ** prior to returning.

  8220. */

  8221. typedef struct sqlite3_mutex_methods sqlite3_mutex_methods;

  8222. struct sqlite3_mutex_methods {

  8223.   int (*xMutexInit)(void);

  8224.   int (*xMutexEnd)(void);

  8225.   sqlite3_mutex *(*xMutexAlloc)(int);

  8226.   void (*xMutexFree)(sqlite3_mutex *);

  8227.   void (*xMutexEnter)(sqlite3_mutex *);

  8228.   int (*xMutexTry)(sqlite3_mutex *);

  8229.   void (*xMutexLeave)(sqlite3_mutex *);

  8230.   int (*xMutexHeld)(sqlite3_mutex *);

  8231.   int (*xMutexNotheld)(sqlite3_mutex *);

  8232. };

  8233. 

  8234. /*

  8235. ** CAPI3REF: Mutex Verification Routines

  8236. **

  8237. ** The sqlite3_mutex_held() and sqlite3_mutex_notheld() routines

  8238. ** are intended for use inside assert() statements.  The SQLite core

  8239. ** never uses these routines except inside an assert() and applications

  8240. ** are advised to follow the lead of the core.  The SQLite core only

  8241. ** provides implementations for these routines when it is compiled

  8242. ** with the SQLITE_DEBUG flag.  External mutex implementations

  8243. ** are only required to provide these routines if SQLITE_DEBUG is

  8244. ** defined and if NDEBUG is not defined.

  8245. **

  8246. ** These routines should return true if the mutex in their argument

  8247. ** is held or not held, respectively, by the calling thread.

  8248. **

  8249. ** The implementation is not required to provide versions of these

  8250. ** routines that actually work. If the implementation does not provide working

  8251. ** versions of these routines, it should at least provide stubs that always

  8252. ** return true so that one does not get spurious assertion failures.

  8253. **

  8254. ** If the argument to sqlite3_mutex_held() is a NULL pointer then

  8255. ** the routine should return 1.   This seems counter-intuitive since

  8256. ** clearly the mutex cannot be held if it does not exist.  But

  8257. ** the reason the mutex does not exist is because the build is not

  8258. ** using mutexes.  And we do not want the assert() containing the

  8259. ** call to sqlite3_mutex_held() to fail, so a non-zero return is

  8260. ** the appropriate thing to do.  The sqlite3_mutex_notheld()

  8261. ** interface should also return 1 when given a NULL pointer.

  8262. */

  8263. #ifndef NDEBUG

  8264. SQLITE_API int sqlite3_mutex_held(sqlite3_mutex*);

  8265. SQLITE_API int sqlite3_mutex_notheld(sqlite3_mutex*);

  8266. #endif

  8267. 

  8268. /*

  8269. ** CAPI3REF: Mutex Types

  8270. **

  8271. ** The [sqlite3_mutex_alloc()] interface takes a single argument

  8272. ** which is one of these integer constants.

  8273. **

  8274. ** The set of static mutexes may change from one SQLite release to the

  8275. ** next.  Applications that override the built-in mutex logic must be

  8276. ** prepared to accommodate additional static mutexes.

  8277. */

  8278. #define SQLITE_MUTEX_FAST             0

  8279. #define SQLITE_MUTEX_RECURSIVE        1

  8280. #define SQLITE_MUTEX_STATIC_MASTER    2

  8281. #define SQLITE_MUTEX_STATIC_MEM       3  /* sqlite3_malloc() */

  8282. #define SQLITE_MUTEX_STATIC_MEM2      4  /* NOT USED */

  8283. #define SQLITE_MUTEX_STATIC_OPEN      4  /* sqlite3BtreeOpen() */

  8284. #define SQLITE_MUTEX_STATIC_PRNG      5  /* sqlite3_randomness() */

  8285. #define SQLITE_MUTEX_STATIC_LRU       6  /* lru page list */

  8286. #define SQLITE_MUTEX_STATIC_LRU2      7  /* NOT USED */

  8287. #define SQLITE_MUTEX_STATIC_PMEM      7  /* sqlite3PageMalloc() */

  8288. #define SQLITE_MUTEX_STATIC_APP1      8  /* For use by application */

  8289. #define SQLITE_MUTEX_STATIC_APP2      9  /* For use by application */

  8290. #define SQLITE_MUTEX_STATIC_APP3     10  /* For use by application */

  8291. #define SQLITE_MUTEX_STATIC_VFS1     11  /* For use by built-in VFS */

  8292. #define SQLITE_MUTEX_STATIC_VFS2     12  /* For use by extension VFS */

  8293. #define SQLITE_MUTEX_STATIC_VFS3     13  /* For use by application VFS */

  8294. 

  8295. /*

  8296. ** CAPI3REF: Retrieve the mutex for a database connection

  8297. ** METHOD: sqlite3

  8298. **

  8299. ** ^This interface returns a pointer the [sqlite3_mutex] object that 

  8300. ** serializes access to the [database connection] given in the argument

  8301. ** when the [threading mode] is Serialized.

  8302. ** ^If the [threading mode] is Single-thread or Multi-thread then this

  8303. ** routine returns a NULL pointer.

  8304. */

  8305. SQLITE_API sqlite3_mutex *sqlite3_db_mutex(sqlite3*);

  8306. 

  8307. /*

  8308. ** CAPI3REF: Low-Level Control Of Database Files

  8309. ** METHOD: sqlite3

  8310. ** KEYWORDS: {file control}

  8311. **

  8312. ** ^The [sqlite3_file_control()] interface makes a direct call to the

  8313. ** xFileControl method for the [sqlite3_io_methods] object associated

  8314. ** with a particular database identified by the second argument. ^The

  8315. ** name of the database is "main" for the main database or "temp" for the

  8316. ** TEMP database, or the name that appears after the AS keyword for

  8317. ** databases that are added using the [ATTACH] SQL command.

  8318. ** ^A NULL pointer can be used in place of "main" to refer to the

  8319. ** main database file.

  8320. ** ^The third and fourth parameters to this routine

  8321. ** are passed directly through to the second and third parameters of

  8322. ** the xFileControl method.  ^The return value of the xFileControl

  8323. ** method becomes the return value of this routine.

  8324. **

  8325. ** A few opcodes for [sqlite3_file_control()] are handled directly

  8326. ** by the SQLite core and never invoke the 

  8327. ** sqlite3_io_methods.xFileControl method.

  8328. ** ^The [SQLITE_FCNTL_FILE_POINTER] value for the op parameter causes

  8329. ** a pointer to the underlying [sqlite3_file] object to be written into

  8330. ** the space pointed to by the 4th parameter.  The

  8331. ** [SQLITE_FCNTL_JOURNAL_POINTER] works similarly except that it returns

  8332. ** the [sqlite3_file] object associated with the journal file instead of

  8333. ** the main database.  The [SQLITE_FCNTL_VFS_POINTER] opcode returns

  8334. ** a pointer to the underlying [sqlite3_vfs] object for the file.

  8335. ** The [SQLITE_FCNTL_DATA_VERSION] returns the data version counter

  8336. ** from the pager.

  8337. **

  8338. ** ^If the second parameter (zDbName) does not match the name of any

  8339. ** open database file, then SQLITE_ERROR is returned.  ^This error

  8340. ** code is not remembered and will not be recalled by [sqlite3_errcode()]

  8341. ** or [sqlite3_errmsg()].  The underlying xFileControl method might

  8342. ** also return SQLITE_ERROR.  There is no way to distinguish between

  8343. ** an incorrect zDbName and an SQLITE_ERROR return from the underlying

  8344. ** xFileControl method.

  8345. **

  8346. ** See also: [file control opcodes]

  8347. */

  8348. SQLITE_API int sqlite3_file_control(sqlite3*, const char *zDbName, int op, void*);

  8349. 

  8350. /*

  8351. ** CAPI3REF: Testing Interface

  8352. **

  8353. ** ^The sqlite3_test_control() interface is used to read out internal

  8354. ** state of SQLite and to inject faults into SQLite for testing

  8355. ** purposes.  ^The first parameter is an operation code that determines

  8356. ** the number, meaning, and operation of all subsequent parameters.

  8357. **

  8358. ** This interface is not for use by applications.  It exists solely

  8359. ** for verifying the correct operation of the SQLite library.  Depending

  8360. ** on how the SQLite library is compiled, this interface might not exist.

  8361. **

  8362. ** The details of the operation codes, their meanings, the parameters

  8363. ** they take, and what they do are all subject to change without notice.

  8364. ** Unlike most of the SQLite API, this function is not guaranteed to

  8365. ** operate consistently from one release to the next.

  8366. */

  8367. SQLITE_API int sqlite3_test_control(int op, ...);

  8368. 

  8369. /*

  8370. ** CAPI3REF: Testing Interface Operation Codes

  8371. **

  8372. ** These constants are the valid operation code parameters used

  8373. ** as the first argument to [sqlite3_test_control()].

  8374. **

  8375. ** These parameters and their meanings are subject to change

  8376. ** without notice.  These values are for testing purposes only.

  8377. ** Applications should not use any of these parameters or the

  8378. ** [sqlite3_test_control()] interface.

  8379. */

  8380. #define SQLITE_TESTCTRL_FIRST                    5

  8381. #define SQLITE_TESTCTRL_PRNG_SAVE                5

  8382. #define SQLITE_TESTCTRL_PRNG_RESTORE             6

  8383. #define SQLITE_TESTCTRL_PRNG_RESET               7

  8384. #define SQLITE_TESTCTRL_BITVEC_TEST              8

  8385. #define SQLITE_TESTCTRL_FAULT_INSTALL            9

  8386. #define SQLITE_TESTCTRL_BENIGN_MALLOC_HOOKS     10

  8387. #define SQLITE_TESTCTRL_PENDING_BYTE            11

  8388. #define SQLITE_TESTCTRL_ASSERT                  12

  8389. #define SQLITE_TESTCTRL_ALWAYS                  13

  8390. #define SQLITE_TESTCTRL_RESERVE                 14

  8391. #define SQLITE_TESTCTRL_OPTIMIZATIONS           15

  8392. #define SQLITE_TESTCTRL_ISKEYWORD               16  /* NOT USED */

  8393. #define SQLITE_TESTCTRL_SCRATCHMALLOC           17  /* NOT USED */

  8394. #define SQLITE_TESTCTRL_INTERNAL_FUNCTIONS      17

  8395. #define SQLITE_TESTCTRL_LOCALTIME_FAULT         18

  8396. #define SQLITE_TESTCTRL_EXPLAIN_STMT            19  /* NOT USED */

  8397. #define SQLITE_TESTCTRL_ONCE_RESET_THRESHOLD    19

  8398. #define SQLITE_TESTCTRL_NEVER_CORRUPT           20

  8399. #define SQLITE_TESTCTRL_VDBE_COVERAGE           21

  8400. #define SQLITE_TESTCTRL_BYTEORDER               22

  8401. #define SQLITE_TESTCTRL_ISINIT                  23

  8402. #define SQLITE_TESTCTRL_SORTER_MMAP             24

  8403. #define SQLITE_TESTCTRL_IMPOSTER                25

  8404. #define SQLITE_TESTCTRL_PARSER_COVERAGE         26

  8405. #define SQLITE_TESTCTRL_RESULT_INTREAL          27

  8406. #define SQLITE_TESTCTRL_LAST                    27  /* Largest TESTCTRL */

  8407. 

  8408. /*

  8409. ** CAPI3REF: SQL Keyword Checking

  8410. **

  8411. ** These routines provide access to the set of SQL language keywords 

  8412. ** recognized by SQLite.  Applications can uses these routines to determine

  8413. ** whether or not a specific identifier needs to be escaped (for example,

  8414. ** by enclosing in double-quotes) so as not to confuse the parser.

  8415. **

  8416. ** The sqlite3_keyword_count() interface returns the number of distinct

  8417. ** keywords understood by SQLite.

  8418. **

  8419. ** The sqlite3_keyword_name(N,Z,L) interface finds the N-th keyword and

  8420. ** makes *Z point to that keyword expressed as UTF8 and writes the number

  8421. ** of bytes in the keyword into *L.  The string that *Z points to is not

  8422. ** zero-terminated.  The sqlite3_keyword_name(N,Z,L) routine returns

  8423. ** SQLITE_OK if N is within bounds and SQLITE_ERROR if not. If either Z

  8424. ** or L are NULL or invalid pointers then calls to

  8425. ** sqlite3_keyword_name(N,Z,L) result in undefined behavior.

  8426. **

  8427. ** The sqlite3_keyword_check(Z,L) interface checks to see whether or not

  8428. ** the L-byte UTF8 identifier that Z points to is a keyword, returning non-zero

  8429. ** if it is and zero if not.

  8430. **

  8431. ** The parser used by SQLite is forgiving.  It is often possible to use

  8432. ** a keyword as an identifier as long as such use does not result in a

  8433. ** parsing ambiguity.  For example, the statement

  8434. ** "CREATE TABLE BEGIN(REPLACE,PRAGMA,END);" is accepted by SQLite, and

  8435. ** creates a new table named "BEGIN" with three columns named

  8436. ** "REPLACE", "PRAGMA", and "END".  Nevertheless, best practice is to avoid

  8437. ** using keywords as identifiers.  Common techniques used to avoid keyword

  8438. ** name collisions include:

  8439. ** <ul>

  8440. ** <li> Put all identifier names inside double-quotes.  This is the official

  8441. **      SQL way to escape identifier names.

  8442. ** <li> Put identifier names inside &#91;...&#93;.  This is not standard SQL,

  8443. **      but it is what SQL Server does and so lots of programmers use this

  8444. **      technique.

  8445. ** <li> Begin every identifier with the letter "Z" as no SQL keywords start

  8446. **      with "Z".

  8447. ** <li> Include a digit somewhere in every identifier name.

  8448. ** </ul>

  8449. **

  8450. ** Note that the number of keywords understood by SQLite can depend on

  8451. ** compile-time options.  For example, "VACUUM" is not a keyword if

  8452. ** SQLite is compiled with the [-DSQLITE_OMIT_VACUUM] option.  Also,

  8453. ** new keywords may be added to future releases of SQLite.

  8454. */

  8455. SQLITE_API int sqlite3_keyword_count(void);

  8456. SQLITE_API int sqlite3_keyword_name(int,const char**,int*);

  8457. SQLITE_API int sqlite3_keyword_check(const char*,int);

  8458. 

  8459. /*

  8460. ** CAPI3REF: Dynamic String Object

  8461. ** KEYWORDS: {dynamic string}

  8462. **

  8463. ** An instance of the sqlite3_str object contains a dynamically-sized

  8464. ** string under construction.

  8465. **

  8466. ** The lifecycle of an sqlite3_str object is as follows:

  8467. ** <ol>

  8468. ** <li> ^The sqlite3_str object is created using [sqlite3_str_new()].

  8469. ** <li> ^Text is appended to the sqlite3_str object using various

  8470. ** methods, such as [sqlite3_str_appendf()].

  8471. ** <li> ^The sqlite3_str object is destroyed and the string it created

  8472. ** is returned using the [sqlite3_str_finish()] interface.

  8473. ** </ol>

  8474. */

  8475. typedef struct sqlite3_str sqlite3_str;

  8476. 

  8477. /*

  8478. ** CAPI3REF: Create A New Dynamic String Object

  8479. ** CONSTRUCTOR: sqlite3_str

  8480. **

  8481. ** ^The [sqlite3_str_new(D)] interface allocates and initializes

  8482. ** a new [sqlite3_str] object.  To avoid memory leaks, the object returned by

  8483. ** [sqlite3_str_new()] must be freed by a subsequent call to 

  8484. ** [sqlite3_str_finish(X)].

  8485. **

  8486. ** ^The [sqlite3_str_new(D)] interface always returns a pointer to a

  8487. ** valid [sqlite3_str] object, though in the event of an out-of-memory

  8488. ** error the returned object might be a special singleton that will

  8489. ** silently reject new text, always return SQLITE_NOMEM from 

  8490. ** [sqlite3_str_errcode()], always return 0 for 

  8491. ** [sqlite3_str_length()], and always return NULL from

  8492. ** [sqlite3_str_finish(X)].  It is always safe to use the value

  8493. ** returned by [sqlite3_str_new(D)] as the sqlite3_str parameter

  8494. ** to any of the other [sqlite3_str] methods.

  8495. **

  8496. ** The D parameter to [sqlite3_str_new(D)] may be NULL.  If the

  8497. ** D parameter in [sqlite3_str_new(D)] is not NULL, then the maximum

  8498. ** length of the string contained in the [sqlite3_str] object will be

  8499. ** the value set for [sqlite3_limit](D,[SQLITE_LIMIT_LENGTH]) instead

  8500. ** of [SQLITE_MAX_LENGTH].

  8501. */

  8502. SQLITE_API sqlite3_str *sqlite3_str_new(sqlite3*);

  8503. 

  8504. /*

  8505. ** CAPI3REF: Finalize A Dynamic String

  8506. ** DESTRUCTOR: sqlite3_str

  8507. **

  8508. ** ^The [sqlite3_str_finish(X)] interface destroys the sqlite3_str object X

  8509. ** and returns a pointer to a memory buffer obtained from [sqlite3_malloc64()]

  8510. ** that contains the constructed string.  The calling application should

  8511. ** pass the returned value to [sqlite3_free()] to avoid a memory leak.

  8512. ** ^The [sqlite3_str_finish(X)] interface may return a NULL pointer if any

  8513. ** errors were encountered during construction of the string.  ^The

  8514. ** [sqlite3_str_finish(X)] interface will also return a NULL pointer if the

  8515. ** string in [sqlite3_str] object X is zero bytes long.

  8516. */

  8517. SQLITE_API char *sqlite3_str_finish(sqlite3_str*);

  8518. 

  8519. /*

  8520. ** CAPI3REF: Add Content To A Dynamic String

  8521. ** METHOD: sqlite3_str

  8522. **

  8523. ** These interfaces add content to an sqlite3_str object previously obtained

  8524. ** from [sqlite3_str_new()].

  8525. **

  8526. ** ^The [sqlite3_str_appendf(X,F,...)] and 

  8527. ** [sqlite3_str_vappendf(X,F,V)] interfaces uses the [built-in printf]

  8528. ** functionality of SQLite to append formatted text onto the end of 

  8529. ** [sqlite3_str] object X.

  8530. **

  8531. ** ^The [sqlite3_str_append(X,S,N)] method appends exactly N bytes from string S

  8532. ** onto the end of the [sqlite3_str] object X.  N must be non-negative.

  8533. ** S must contain at least N non-zero bytes of content.  To append a

  8534. ** zero-terminated string in its entirety, use the [sqlite3_str_appendall()]

  8535. ** method instead.

  8536. **

  8537. ** ^The [sqlite3_str_appendall(X,S)] method appends the complete content of

  8538. ** zero-terminated string S onto the end of [sqlite3_str] object X.

  8539. **

  8540. ** ^The [sqlite3_str_appendchar(X,N,C)] method appends N copies of the

  8541. ** single-byte character C onto the end of [sqlite3_str] object X.

  8542. ** ^This method can be used, for example, to add whitespace indentation.

  8543. **

  8544. ** ^The [sqlite3_str_reset(X)] method resets the string under construction

  8545. ** inside [sqlite3_str] object X back to zero bytes in length.  

  8546. **

  8547. ** These methods do not return a result code.  ^If an error occurs, that fact

  8548. ** is recorded in the [sqlite3_str] object and can be recovered by a

  8549. ** subsequent call to [sqlite3_str_errcode(X)].

  8550. */

  8551. SQLITE_API void sqlite3_str_appendf(sqlite3_str*, const char *zFormat, ...);

  8552. SQLITE_API void sqlite3_str_vappendf(sqlite3_str*, const char *zFormat, va_list);

  8553. SQLITE_API void sqlite3_str_append(sqlite3_str*, const char *zIn, int N);

  8554. SQLITE_API void sqlite3_str_appendall(sqlite3_str*, const char *zIn);

  8555. SQLITE_API void sqlite3_str_appendchar(sqlite3_str*, int N, char C);

  8556. SQLITE_API void sqlite3_str_reset(sqlite3_str*);

  8557. 

  8558. /*

  8559. ** CAPI3REF: Status Of A Dynamic String

  8560. ** METHOD: sqlite3_str

  8561. **

  8562. ** These interfaces return the current status of an [sqlite3_str] object.

  8563. **

  8564. ** ^If any prior errors have occurred while constructing the dynamic string

  8565. ** in sqlite3_str X, then the [sqlite3_str_errcode(X)] method will return

  8566. ** an appropriate error code.  ^The [sqlite3_str_errcode(X)] method returns

  8567. ** [SQLITE_NOMEM] following any out-of-memory error, or

  8568. ** [SQLITE_TOOBIG] if the size of the dynamic string exceeds

  8569. ** [SQLITE_MAX_LENGTH], or [SQLITE_OK] if there have been no errors.

  8570. **

  8571. ** ^The [sqlite3_str_length(X)] method returns the current length, in bytes,

  8572. ** of the dynamic string under construction in [sqlite3_str] object X.

  8573. ** ^The length returned by [sqlite3_str_length(X)] does not include the

  8574. ** zero-termination byte.

  8575. **

  8576. ** ^The [sqlite3_str_value(X)] method returns a pointer to the current

  8577. ** content of the dynamic string under construction in X.  The value

  8578. ** returned by [sqlite3_str_value(X)] is managed by the sqlite3_str object X

  8579. ** and might be freed or altered by any subsequent method on the same

  8580. ** [sqlite3_str] object.  Applications must not used the pointer returned

  8581. ** [sqlite3_str_value(X)] after any subsequent method call on the same

  8582. ** object.  ^Applications may change the content of the string returned

  8583. ** by [sqlite3_str_value(X)] as long as they do not write into any bytes

  8584. ** outside the range of 0 to [sqlite3_str_length(X)] and do not read or

  8585. ** write any byte after any subsequent sqlite3_str method call.

  8586. */

  8587. SQLITE_API int sqlite3_str_errcode(sqlite3_str*);

  8588. SQLITE_API int sqlite3_str_length(sqlite3_str*);

  8589. SQLITE_API char *sqlite3_str_value(sqlite3_str*);

  8590. 

  8591. /*

  8592. ** CAPI3REF: SQLite Runtime Status

  8593. **

  8594. ** ^These interfaces are used to retrieve runtime status information

  8595. ** about the performance of SQLite, and optionally to reset various

  8596. ** highwater marks.  ^The first argument is an integer code for

  8597. ** the specific parameter to measure.  ^(Recognized integer codes

  8598. ** are of the form [status parameters | SQLITE_STATUS_...].)^

  8599. ** ^The current value of the parameter is returned into *pCurrent.

  8600. ** ^The highest recorded value is returned in *pHighwater.  ^If the

  8601. ** resetFlag is true, then the highest record value is reset after

  8602. ** *pHighwater is written.  ^(Some parameters do not record the highest

  8603. ** value.  For those parameters

  8604. ** nothing is written into *pHighwater and the resetFlag is ignored.)^

  8605. ** ^(Other parameters record only the highwater mark and not the current

  8606. ** value.  For these latter parameters nothing is written into *pCurrent.)^

  8607. **

  8608. ** ^The sqlite3_status() and sqlite3_status64() routines return

  8609. ** SQLITE_OK on success and a non-zero [error code] on failure.

  8610. **

  8611. ** If either the current value or the highwater mark is too large to

  8612. ** be represented by a 32-bit integer, then the values returned by

  8613. ** sqlite3_status() are undefined.

  8614. **

  8615. ** See also: [sqlite3_db_status()]

  8616. */

  8617. SQLITE_API int sqlite3_status(int op, int *pCurrent, int *pHighwater, int resetFlag);

  8618. SQLITE_API int sqlite3_status64(

  8619.   int op,

  8620.   sqlite3_int64 *pCurrent,

  8621.   sqlite3_int64 *pHighwater,

  8622.   int resetFlag

  8623. );

  8624. 

  8625. 

  8626. /*

  8627. ** CAPI3REF: Status Parameters

  8628. ** KEYWORDS: {status parameters}

  8629. **

  8630. ** These integer constants designate various run-time status parameters

  8631. ** that can be returned by [sqlite3_status()].

  8632. **

  8633. ** <dl>

  8634. ** [[SQLITE_STATUS_MEMORY_USED]] ^(<dt>SQLITE_STATUS_MEMORY_USED</dt>

  8635. ** <dd>This parameter is the current amount of memory checked out

  8636. ** using [sqlite3_malloc()], either directly or indirectly.  The

  8637. ** figure includes calls made to [sqlite3_malloc()] by the application

  8638. ** and internal memory usage by the SQLite library.  Auxiliary page-cache

  8639. ** memory controlled by [SQLITE_CONFIG_PAGECACHE] is not included in

  8640. ** this parameter.  The amount returned is the sum of the allocation

  8641. ** sizes as reported by the xSize method in [sqlite3_mem_methods].</dd>)^

  8642. **

  8643. ** [[SQLITE_STATUS_MALLOC_SIZE]] ^(<dt>SQLITE_STATUS_MALLOC_SIZE</dt>

  8644. ** <dd>This parameter records the largest memory allocation request

  8645. ** handed to [sqlite3_malloc()] or [sqlite3_realloc()] (or their

  8646. ** internal equivalents).  Only the value returned in the

  8647. ** *pHighwater parameter to [sqlite3_status()] is of interest.  

  8648. ** The value written into the *pCurrent parameter is undefined.</dd>)^

  8649. **

  8650. ** [[SQLITE_STATUS_MALLOC_COUNT]] ^(<dt>SQLITE_STATUS_MALLOC_COUNT</dt>

  8651. ** <dd>This parameter records the number of separate memory allocations

  8652. ** currently checked out.</dd>)^

  8653. **

  8654. ** [[SQLITE_STATUS_PAGECACHE_USED]] ^(<dt>SQLITE_STATUS_PAGECACHE_USED</dt>

  8655. ** <dd>This parameter returns the number of pages used out of the

  8656. ** [pagecache memory allocator] that was configured using 

  8657. ** [SQLITE_CONFIG_PAGECACHE].  The

  8658. ** value returned is in pages, not in bytes.</dd>)^

  8659. **

  8660. ** [[SQLITE_STATUS_PAGECACHE_OVERFLOW]] 

  8661. ** ^(<dt>SQLITE_STATUS_PAGECACHE_OVERFLOW</dt>

  8662. ** <dd>This parameter returns the number of bytes of page cache

  8663. ** allocation which could not be satisfied by the [SQLITE_CONFIG_PAGECACHE]

  8664. ** buffer and where forced to overflow to [sqlite3_malloc()].  The

  8665. ** returned value includes allocations that overflowed because they

  8666. ** where too large (they were larger than the "sz" parameter to

  8667. ** [SQLITE_CONFIG_PAGECACHE]) and allocations that overflowed because

  8668. ** no space was left in the page cache.</dd>)^

  8669. **

  8670. ** [[SQLITE_STATUS_PAGECACHE_SIZE]] ^(<dt>SQLITE_STATUS_PAGECACHE_SIZE</dt>

  8671. ** <dd>This parameter records the largest memory allocation request

  8672. ** handed to [pagecache memory allocator].  Only the value returned in the

  8673. ** *pHighwater parameter to [sqlite3_status()] is of interest.  

  8674. ** The value written into the *pCurrent parameter is undefined.</dd>)^

  8675. **

  8676. ** [[SQLITE_STATUS_SCRATCH_USED]] <dt>SQLITE_STATUS_SCRATCH_USED</dt>

  8677. ** <dd>No longer used.</dd>

  8678. **

  8679. ** [[SQLITE_STATUS_SCRATCH_OVERFLOW]] ^(<dt>SQLITE_STATUS_SCRATCH_OVERFLOW</dt>

  8680. ** <dd>No longer used.</dd>

  8681. **

  8682. ** [[SQLITE_STATUS_SCRATCH_SIZE]] <dt>SQLITE_STATUS_SCRATCH_SIZE</dt>

  8683. ** <dd>No longer used.</dd>

  8684. **

  8685. ** [[SQLITE_STATUS_PARSER_STACK]] ^(<dt>SQLITE_STATUS_PARSER_STACK</dt>

  8686. ** <dd>The *pHighwater parameter records the deepest parser stack. 

  8687. ** The *pCurrent value is undefined.  The *pHighwater value is only

  8688. ** meaningful if SQLite is compiled with [YYTRACKMAXSTACKDEPTH].</dd>)^

  8689. ** </dl>

  8690. **

  8691. ** New status parameters may be added from time to time.

  8692. */

  8693. #define SQLITE_STATUS_MEMORY_USED          0

  8694. #define SQLITE_STATUS_PAGECACHE_USED       1

  8695. #define SQLITE_STATUS_PAGECACHE_OVERFLOW   2

  8696. #define SQLITE_STATUS_SCRATCH_USED         3  /* NOT USED */

  8697. #define SQLITE_STATUS_SCRATCH_OVERFLOW     4  /* NOT USED */

  8698. #define SQLITE_STATUS_MALLOC_SIZE          5

  8699. #define SQLITE_STATUS_PARSER_STACK         6

  8700. #define SQLITE_STATUS_PAGECACHE_SIZE       7

  8701. #define SQLITE_STATUS_SCRATCH_SIZE         8  /* NOT USED */

  8702. #define SQLITE_STATUS_MALLOC_COUNT         9

  8703. 

  8704. /*

  8705. ** CAPI3REF: Database Connection Status

  8706. ** METHOD: sqlite3

  8707. **

  8708. ** ^This interface is used to retrieve runtime status information 

  8709. ** about a single [database connection].  ^The first argument is the

  8710. ** database connection object to be interrogated.  ^The second argument

  8711. ** is an integer constant, taken from the set of

  8712. ** [SQLITE_DBSTATUS options], that

  8713. ** determines the parameter to interrogate.  The set of 

  8714. ** [SQLITE_DBSTATUS options] is likely

  8715. ** to grow in future releases of SQLite.

  8716. **

  8717. ** ^The current value of the requested parameter is written into *pCur

  8718. ** and the highest instantaneous value is written into *pHiwtr.  ^If

  8719. ** the resetFlg is true, then the highest instantaneous value is

  8720. ** reset back down to the current value.

  8721. **

  8722. ** ^The sqlite3_db_status() routine returns SQLITE_OK on success and a

  8723. ** non-zero [error code] on failure.

  8724. **

  8725. ** See also: [sqlite3_status()] and [sqlite3_stmt_status()].

  8726. */

  8727. SQLITE_API int sqlite3_db_status(sqlite3*, int op, int *pCur, int *pHiwtr, int resetFlg);

  8728. 

  8729. /*

  8730. ** CAPI3REF: Status Parameters for database connections

  8731. ** KEYWORDS: {SQLITE_DBSTATUS options}

  8732. **

  8733. ** These constants are the available integer "verbs" that can be passed as

  8734. ** the second argument to the [sqlite3_db_status()] interface.

  8735. **

  8736. ** New verbs may be added in future releases of SQLite. Existing verbs

  8737. ** might be discontinued. Applications should check the return code from

  8738. ** [sqlite3_db_status()] to make sure that the call worked.

  8739. ** The [sqlite3_db_status()] interface will return a non-zero error code

  8740. ** if a discontinued or unsupported verb is invoked.

  8741. **

  8742. ** <dl>

  8743. ** [[SQLITE_DBSTATUS_LOOKASIDE_USED]] ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_USED</dt>

  8744. ** <dd>This parameter returns the number of lookaside memory slots currently

  8745. ** checked out.</dd>)^

  8746. **

  8747. ** [[SQLITE_DBSTATUS_LOOKASIDE_HIT]] ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_HIT</dt>

  8748. ** <dd>This parameter returns the number malloc attempts that were 

  8749. ** satisfied using lookaside memory. Only the high-water value is meaningful;

  8750. ** the current value is always zero.)^

  8751. **

  8752. ** [[SQLITE_DBSTATUS_LOOKASIDE_MISS_SIZE]]

  8753. ** ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_MISS_SIZE</dt>

  8754. ** <dd>This parameter returns the number malloc attempts that might have

  8755. ** been satisfied using lookaside memory but failed due to the amount of

  8756. ** memory requested being larger than the lookaside slot size.

  8757. ** Only the high-water value is meaningful;

  8758. ** the current value is always zero.)^

  8759. **

  8760. ** [[SQLITE_DBSTATUS_LOOKASIDE_MISS_FULL]]

  8761. ** ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_MISS_FULL</dt>

  8762. ** <dd>This parameter returns the number malloc attempts that might have

  8763. ** been satisfied using lookaside memory but failed due to all lookaside

  8764. ** memory already being in use.

  8765. ** Only the high-water value is meaningful;

  8766. ** the current value is always zero.)^

  8767. **

  8768. ** [[SQLITE_DBSTATUS_CACHE_USED]] ^(<dt>SQLITE_DBSTATUS_CACHE_USED</dt>

  8769. ** <dd>This parameter returns the approximate number of bytes of heap

  8770. ** memory used by all pager caches associated with the database connection.)^

  8771. ** ^The highwater mark associated with SQLITE_DBSTATUS_CACHE_USED is always 0.

  8772. **

  8773. ** [[SQLITE_DBSTATUS_CACHE_USED_SHARED]] 

  8774. ** ^(<dt>SQLITE_DBSTATUS_CACHE_USED_SHARED</dt>

  8775. ** <dd>This parameter is similar to DBSTATUS_CACHE_USED, except that if a

  8776. ** pager cache is shared between two or more connections the bytes of heap

  8777. ** memory used by that pager cache is divided evenly between the attached

  8778. ** connections.)^  In other words, if none of the pager caches associated

  8779. ** with the database connection are shared, this request returns the same

  8780. ** value as DBSTATUS_CACHE_USED. Or, if one or more or the pager caches are

  8781. ** shared, the value returned by this call will be smaller than that returned

  8782. ** by DBSTATUS_CACHE_USED. ^The highwater mark associated with

  8783. ** SQLITE_DBSTATUS_CACHE_USED_SHARED is always 0.

  8784. **

  8785. ** [[SQLITE_DBSTATUS_SCHEMA_USED]] ^(<dt>SQLITE_DBSTATUS_SCHEMA_USED</dt>

  8786. ** <dd>This parameter returns the approximate number of bytes of heap

  8787. ** memory used to store the schema for all databases associated

  8788. ** with the connection - main, temp, and any [ATTACH]-ed databases.)^ 

  8789. ** ^The full amount of memory used by the schemas is reported, even if the

  8790. ** schema memory is shared with other database connections due to

  8791. ** [shared cache mode] being enabled.

  8792. ** ^The highwater mark associated with SQLITE_DBSTATUS_SCHEMA_USED is always 0.

  8793. **

  8794. ** [[SQLITE_DBSTATUS_STMT_USED]] ^(<dt>SQLITE_DBSTATUS_STMT_USED</dt>

  8795. ** <dd>This parameter returns the approximate number of bytes of heap

  8796. ** and lookaside memory used by all prepared statements associated with

  8797. ** the database connection.)^

  8798. ** ^The highwater mark associated with SQLITE_DBSTATUS_STMT_USED is always 0.

  8799. ** </dd>

  8800. **

  8801. ** [[SQLITE_DBSTATUS_CACHE_HIT]] ^(<dt>SQLITE_DBSTATUS_CACHE_HIT</dt>

  8802. ** <dd>This parameter returns the number of pager cache hits that have

  8803. ** occurred.)^ ^The highwater mark associated with SQLITE_DBSTATUS_CACHE_HIT 

  8804. ** is always 0.

  8805. ** </dd>

  8806. **

  8807. ** [[SQLITE_DBSTATUS_CACHE_MISS]] ^(<dt>SQLITE_DBSTATUS_CACHE_MISS</dt>

  8808. ** <dd>This parameter returns the number of pager cache misses that have

  8809. ** occurred.)^ ^The highwater mark associated with SQLITE_DBSTATUS_CACHE_MISS 

  8810. ** is always 0.

  8811. ** </dd>

  8812. **

  8813. ** [[SQLITE_DBSTATUS_CACHE_WRITE]] ^(<dt>SQLITE_DBSTATUS_CACHE_WRITE</dt>

  8814. ** <dd>This parameter returns the number of dirty cache entries that have

  8815. ** been written to disk. Specifically, the number of pages written to the

  8816. ** wal file in wal mode databases, or the number of pages written to the

  8817. ** database file in rollback mode databases. Any pages written as part of

  8818. ** transaction rollback or database recovery operations are not included.

  8819. ** If an IO or other error occurs while writing a page to disk, the effect

  8820. ** on subsequent SQLITE_DBSTATUS_CACHE_WRITE requests is undefined.)^ ^The

  8821. ** highwater mark associated with SQLITE_DBSTATUS_CACHE_WRITE is always 0.

  8822. ** </dd>

  8823. **

  8824. ** [[SQLITE_DBSTATUS_CACHE_SPILL]] ^(<dt>SQLITE_DBSTATUS_CACHE_SPILL</dt>

  8825. ** <dd>This parameter returns the number of dirty cache entries that have

  8826. ** been written to disk in the middle of a transaction due to the page

  8827. ** cache overflowing. Transactions are more efficient if they are written

  8828. ** to disk all at once. When pages spill mid-transaction, that introduces

  8829. ** additional overhead. This parameter can be used help identify

  8830. ** inefficiencies that can be resolve by increasing the cache size.

  8831. ** </dd>

  8832. **

  8833. ** [[SQLITE_DBSTATUS_DEFERRED_FKS]] ^(<dt>SQLITE_DBSTATUS_DEFERRED_FKS</dt>

  8834. ** <dd>This parameter returns zero for the current value if and only if

  8835. ** all foreign key constraints (deferred or immediate) have been

  8836. ** resolved.)^  ^The highwater mark is always 0.

  8837. ** </dd>

  8838. ** </dl>

  8839. */

  8840. #define SQLITE_DBSTATUS_LOOKASIDE_USED       0

  8841. #define SQLITE_DBSTATUS_CACHE_USED           1

  8842. #define SQLITE_DBSTATUS_SCHEMA_USED          2

  8843. #define SQLITE_DBSTATUS_STMT_USED            3

  8844. #define SQLITE_DBSTATUS_LOOKASIDE_HIT        4

  8845. #define SQLITE_DBSTATUS_LOOKASIDE_MISS_SIZE  5

  8846. #define SQLITE_DBSTATUS_LOOKASIDE_MISS_FULL  6

  8847. #define SQLITE_DBSTATUS_CACHE_HIT            7

  8848. #define SQLITE_DBSTATUS_CACHE_MISS           8

  8849. #define SQLITE_DBSTATUS_CACHE_WRITE          9

  8850. #define SQLITE_DBSTATUS_DEFERRED_FKS        10

  8851. #define SQLITE_DBSTATUS_CACHE_USED_SHARED   11

  8852. #define SQLITE_DBSTATUS_CACHE_SPILL         12

  8853. #define SQLITE_DBSTATUS_MAX                 12   /* Largest defined DBSTATUS */

  8854. 

  8855. 

  8856. /*

  8857. ** CAPI3REF: Prepared Statement Status

  8858. ** METHOD: sqlite3_stmt

  8859. **

  8860. ** ^(Each prepared statement maintains various

  8861. ** [SQLITE_STMTSTATUS counters] that measure the number

  8862. ** of times it has performed specific operations.)^  These counters can

  8863. ** be used to monitor the performance characteristics of the prepared

  8864. ** statements.  For example, if the number of table steps greatly exceeds

  8865. ** the number of table searches or result rows, that would tend to indicate

  8866. ** that the prepared statement is using a full table scan rather than

  8867. ** an index.  

  8868. **

  8869. ** ^(This interface is used to retrieve and reset counter values from

  8870. ** a [prepared statement].  The first argument is the prepared statement

  8871. ** object to be interrogated.  The second argument

  8872. ** is an integer code for a specific [SQLITE_STMTSTATUS counter]

  8873. ** to be interrogated.)^

  8874. ** ^The current value of the requested counter is returned.

  8875. ** ^If the resetFlg is true, then the counter is reset to zero after this

  8876. ** interface call returns.

  8877. **

  8878. ** See also: [sqlite3_status()] and [sqlite3_db_status()].

  8879. */

  8880. SQLITE_API int sqlite3_stmt_status(sqlite3_stmt*, int op,int resetFlg);

  8881. 

  8882. /*

  8883. ** CAPI3REF: Status Parameters for prepared statements

  8884. ** KEYWORDS: {SQLITE_STMTSTATUS counter} {SQLITE_STMTSTATUS counters}

  8885. **

  8886. ** These preprocessor macros define integer codes that name counter

  8887. ** values associated with the [sqlite3_stmt_status()] interface.

  8888. ** The meanings of the various counters are as follows:

  8889. **

  8890. ** <dl>

  8891. ** [[SQLITE_STMTSTATUS_FULLSCAN_STEP]] <dt>SQLITE_STMTSTATUS_FULLSCAN_STEP</dt>

  8892. ** <dd>^This is the number of times that SQLite has stepped forward in

  8893. ** a table as part of a full table scan.  Large numbers for this counter

  8894. ** may indicate opportunities for performance improvement through 

  8895. ** careful use of indices.</dd>

  8896. **

  8897. ** [[SQLITE_STMTSTATUS_SORT]] <dt>SQLITE_STMTSTATUS_SORT</dt>

  8898. ** <dd>^This is the number of sort operations that have occurred.

  8899. ** A non-zero value in this counter may indicate an opportunity to

  8900. ** improvement performance through careful use of indices.</dd>

  8901. **

  8902. ** [[SQLITE_STMTSTATUS_AUTOINDEX]] <dt>SQLITE_STMTSTATUS_AUTOINDEX</dt>

  8903. ** <dd>^This is the number of rows inserted into transient indices that

  8904. ** were created automatically in order to help joins run faster.

  8905. ** A non-zero value in this counter may indicate an opportunity to

  8906. ** improvement performance by adding permanent indices that do not

  8907. ** need to be reinitialized each time the statement is run.</dd>

  8908. **

  8909. ** [[SQLITE_STMTSTATUS_VM_STEP]] <dt>SQLITE_STMTSTATUS_VM_STEP</dt>

  8910. ** <dd>^This is the number of virtual machine operations executed

  8911. ** by the prepared statement if that number is less than or equal

  8912. ** to 2147483647.  The number of virtual machine operations can be 

  8913. ** used as a proxy for the total work done by the prepared statement.

  8914. ** If the number of virtual machine operations exceeds 2147483647

  8915. ** then the value returned by this statement status code is undefined.

  8916. **

  8917. ** [[SQLITE_STMTSTATUS_REPREPARE]] <dt>SQLITE_STMTSTATUS_REPREPARE</dt>

  8918. ** <dd>^This is the number of times that the prepare statement has been

  8919. ** automatically regenerated due to schema changes or change to 

  8920. ** [bound parameters] that might affect the query plan.

  8921. **

  8922. ** [[SQLITE_STMTSTATUS_RUN]] <dt>SQLITE_STMTSTATUS_RUN</dt>

  8923. ** <dd>^This is the number of times that the prepared statement has

  8924. ** been run.  A single "run" for the purposes of this counter is one

  8925. ** or more calls to [sqlite3_step()] followed by a call to [sqlite3_reset()].

  8926. ** The counter is incremented on the first [sqlite3_step()] call of each

  8927. ** cycle.

  8928. **

  8929. ** [[SQLITE_STMTSTATUS_MEMUSED]] <dt>SQLITE_STMTSTATUS_MEMUSED</dt>

  8930. ** <dd>^This is the approximate number of bytes of heap memory

  8931. ** used to store the prepared statement.  ^This value is not actually

  8932. ** a counter, and so the resetFlg parameter to sqlite3_stmt_status()

  8933. ** is ignored when the opcode is SQLITE_STMTSTATUS_MEMUSED.

  8934. ** </dd>

  8935. ** </dl>

  8936. */

  8937. #define SQLITE_STMTSTATUS_FULLSCAN_STEP     1

  8938. #define SQLITE_STMTSTATUS_SORT              2

  8939. #define SQLITE_STMTSTATUS_AUTOINDEX         3

  8940. #define SQLITE_STMTSTATUS_VM_STEP           4

  8941. #define SQLITE_STMTSTATUS_REPREPARE         5

  8942. #define SQLITE_STMTSTATUS_RUN               6

  8943. #define SQLITE_STMTSTATUS_MEMUSED           99

  8944. 

  8945. /*

  8946. ** CAPI3REF: Custom Page Cache Object

  8947. **

  8948. ** The sqlite3_pcache type is opaque.  It is implemented by

  8949. ** the pluggable module.  The SQLite core has no knowledge of

  8950. ** its size or internal structure and never deals with the

  8951. ** sqlite3_pcache object except by holding and passing pointers

  8952. ** to the object.

  8953. **

  8954. ** See [sqlite3_pcache_methods2] for additional information.

  8955. */

  8956. typedef struct sqlite3_pcache sqlite3_pcache;

  8957. 

  8958. /*

  8959. ** CAPI3REF: Custom Page Cache Object

  8960. **

  8961. ** The sqlite3_pcache_page object represents a single page in the

  8962. ** page cache.  The page cache will allocate instances of this

  8963. ** object.  Various methods of the page cache use pointers to instances

  8964. ** of this object as parameters or as their return value.

  8965. **

  8966. ** See [sqlite3_pcache_methods2] for additional information.

  8967. */

  8968. typedef struct sqlite3_pcache_page sqlite3_pcache_page;

  8969. struct sqlite3_pcache_page {

  8970.   void *pBuf;        /* The content of the page */

  8971.   void *pExtra;      /* Extra information associated with the page */

  8972. };

  8973. 

  8974. /*

  8975. ** CAPI3REF: Application Defined Page Cache.

  8976. ** KEYWORDS: {page cache}

  8977. **

  8978. ** ^(The [sqlite3_config]([SQLITE_CONFIG_PCACHE2], ...) interface can

  8979. ** register an alternative page cache implementation by passing in an 

  8980. ** instance of the sqlite3_pcache_methods2 structure.)^

  8981. ** In many applications, most of the heap memory allocated by 

  8982. ** SQLite is used for the page cache.

  8983. ** By implementing a 

  8984. ** custom page cache using this API, an application can better control

  8985. ** the amount of memory consumed by SQLite, the way in which 

  8986. ** that memory is allocated and released, and the policies used to 

  8987. ** determine exactly which parts of a database file are cached and for 

  8988. ** how long.

  8989. **

  8990. ** The alternative page cache mechanism is an

  8991. ** extreme measure that is only needed by the most demanding applications.

  8992. ** The built-in page cache is recommended for most uses.

  8993. **

  8994. ** ^(The contents of the sqlite3_pcache_methods2 structure are copied to an

  8995. ** internal buffer by SQLite within the call to [sqlite3_config].  Hence

  8996. ** the application may discard the parameter after the call to

  8997. ** [sqlite3_config()] returns.)^

  8998. **

  8999. ** [[the xInit() page cache method]]

  9000. ** ^(The xInit() method is called once for each effective 

  9001. ** call to [sqlite3_initialize()])^

  9002. ** (usually only once during the lifetime of the process). ^(The xInit()

  9003. ** method is passed a copy of the sqlite3_pcache_methods2.pArg value.)^

  9004. ** The intent of the xInit() method is to set up global data structures 

  9005. ** required by the custom page cache implementation. 

  9006. ** ^(If the xInit() method is NULL, then the 

  9007. ** built-in default page cache is used instead of the application defined

  9008. ** page cache.)^

  9009. **

  9010. ** [[the xShutdown() page cache method]]

  9011. ** ^The xShutdown() method is called by [sqlite3_shutdown()].

  9012. ** It can be used to clean up 

  9013. ** any outstanding resources before process shutdown, if required.

  9014. ** ^The xShutdown() method may be NULL.

  9015. **

  9016. ** ^SQLite automatically serializes calls to the xInit method,

  9017. ** so the xInit method need not be threadsafe.  ^The

  9018. ** xShutdown method is only called from [sqlite3_shutdown()] so it does

  9019. ** not need to be threadsafe either.  All other methods must be threadsafe

  9020. ** in multithreaded applications.

  9021. **

  9022. ** ^SQLite will never invoke xInit() more than once without an intervening

  9023. ** call to xShutdown().

  9024. **

  9025. ** [[the xCreate() page cache methods]]

  9026. ** ^SQLite invokes the xCreate() method to construct a new cache instance.

  9027. ** SQLite will typically create one cache instance for each open database file,

  9028. ** though this is not guaranteed. ^The

  9029. ** first parameter, szPage, is the size in bytes of the pages that must

  9030. ** be allocated by the cache.  ^szPage will always a power of two.  ^The

  9031. ** second parameter szExtra is a number of bytes of extra storage 

  9032. ** associated with each page cache entry.  ^The szExtra parameter will

  9033. ** a number less than 250.  SQLite will use the

  9034. ** extra szExtra bytes on each page to store metadata about the underlying

  9035. ** database page on disk.  The value passed into szExtra depends

  9036. ** on the SQLite version, the target platform, and how SQLite was compiled.

  9037. ** ^The third argument to xCreate(), bPurgeable, is true if the cache being

  9038. ** created will be used to cache database pages of a file stored on disk, or

  9039. ** false if it is used for an in-memory database. The cache implementation

  9040. ** does not have to do anything special based with the value of bPurgeable;

  9041. ** it is purely advisory.  ^On a cache where bPurgeable is false, SQLite will

  9042. ** never invoke xUnpin() except to deliberately delete a page.

  9043. ** ^In other words, calls to xUnpin() on a cache with bPurgeable set to

  9044. ** false will always have the "discard" flag set to true.  

  9045. ** ^Hence, a cache created with bPurgeable false will

  9046. ** never contain any unpinned pages.

  9047. **

  9048. ** [[the xCachesize() page cache method]]

  9049. ** ^(The xCachesize() method may be called at any time by SQLite to set the

  9050. ** suggested maximum cache-size (number of pages stored by) the cache

  9051. ** instance passed as the first argument. This is the value configured using

  9052. ** the SQLite "[PRAGMA cache_size]" command.)^  As with the bPurgeable

  9053. ** parameter, the implementation is not required to do anything with this

  9054. ** value; it is advisory only.

  9055. **

  9056. ** [[the xPagecount() page cache methods]]

  9057. ** The xPagecount() method must return the number of pages currently

  9058. ** stored in the cache, both pinned and unpinned.

  9059. ** 

  9060. ** [[the xFetch() page cache methods]]

  9061. ** The xFetch() method locates a page in the cache and returns a pointer to 

  9062. ** an sqlite3_pcache_page object associated with that page, or a NULL pointer.

  9063. ** The pBuf element of the returned sqlite3_pcache_page object will be a

  9064. ** pointer to a buffer of szPage bytes used to store the content of a 

  9065. ** single database page.  The pExtra element of sqlite3_pcache_page will be

  9066. ** a pointer to the szExtra bytes of extra storage that SQLite has requested

  9067. ** for each entry in the page cache.

  9068. **

  9069. ** The page to be fetched is determined by the key. ^The minimum key value

  9070. ** is 1.  After it has been retrieved using xFetch, the page is considered

  9071. ** to be "pinned".

  9072. **

  9073. ** If the requested page is already in the page cache, then the page cache

  9074. ** implementation must return a pointer to the page buffer with its content

  9075. ** intact.  If the requested page is not already in the cache, then the

  9076. ** cache implementation should use the value of the createFlag

  9077. ** parameter to help it determined what action to take:

  9078. **

  9079. ** <table border=1 width=85% align=center>

  9080. ** <tr><th> createFlag <th> Behavior when page is not already in cache

  9081. ** <tr><td> 0 <td> Do not allocate a new page.  Return NULL.

  9082. ** <tr><td> 1 <td> Allocate a new page if it easy and convenient to do so.

  9083. **                 Otherwise return NULL.

  9084. ** <tr><td> 2 <td> Make every effort to allocate a new page.  Only return

  9085. **                 NULL if allocating a new page is effectively impossible.

  9086. ** </table>

  9087. **

  9088. ** ^(SQLite will normally invoke xFetch() with a createFlag of 0 or 1.  SQLite

  9089. ** will only use a createFlag of 2 after a prior call with a createFlag of 1

  9090. ** failed.)^  In between the to xFetch() calls, SQLite may

  9091. ** attempt to unpin one or more cache pages by spilling the content of

  9092. ** pinned pages to disk and synching the operating system disk cache.

  9093. **

  9094. ** [[the xUnpin() page cache method]]

  9095. ** ^xUnpin() is called by SQLite with a pointer to a currently pinned page

  9096. ** as its second argument.  If the third parameter, discard, is non-zero,

  9097. ** then the page must be evicted from the cache.

  9098. ** ^If the discard parameter is

  9099. ** zero, then the page may be discarded or retained at the discretion of

  9100. ** page cache implementation. ^The page cache implementation

  9101. ** may choose to evict unpinned pages at any time.

  9102. **

  9103. ** The cache must not perform any reference counting. A single 

  9104. ** call to xUnpin() unpins the page regardless of the number of prior calls 

  9105. ** to xFetch().

  9106. **

  9107. ** [[the xRekey() page cache methods]]

  9108. ** The xRekey() method is used to change the key value associated with the

  9109. ** page passed as the second argument. If the cache

  9110. ** previously contains an entry associated with newKey, it must be

  9111. ** discarded. ^Any prior cache entry associated with newKey is guaranteed not

  9112. ** to be pinned.

  9113. **

  9114. ** When SQLite calls the xTruncate() method, the cache must discard all

  9115. ** existing cache entries with page numbers (keys) greater than or equal

  9116. ** to the value of the iLimit parameter passed to xTruncate(). If any

  9117. ** of these pages are pinned, they are implicitly unpinned, meaning that

  9118. ** they can be safely discarded.

  9119. **

  9120. ** [[the xDestroy() page cache method]]

  9121. ** ^The xDestroy() method is used to delete a cache allocated by xCreate().

  9122. ** All resources associated with the specified cache should be freed. ^After

  9123. ** calling the xDestroy() method, SQLite considers the [sqlite3_pcache*]

  9124. ** handle invalid, and will not use it with any other sqlite3_pcache_methods2

  9125. ** functions.

  9126. **

  9127. ** [[the xShrink() page cache method]]

  9128. ** ^SQLite invokes the xShrink() method when it wants the page cache to

  9129. ** free up as much of heap memory as possible.  The page cache implementation

  9130. ** is not obligated to free any memory, but well-behaved implementations should

  9131. ** do their best.

  9132. */

  9133. typedef struct sqlite3_pcache_methods2 sqlite3_pcache_methods2;

  9134. struct sqlite3_pcache_methods2 {

  9135.   int iVersion;

  9136.   void *pArg;

  9137.   int (*xInit)(void*);

  9138.   void (*xShutdown)(void*);

  9139.   sqlite3_pcache *(*xCreate)(int szPage, int szExtra, int bPurgeable);

  9140.   void (*xCachesize)(sqlite3_pcache*, int nCachesize);

  9141.   int (*xPagecount)(sqlite3_pcache*);

  9142.   sqlite3_pcache_page *(*xFetch)(sqlite3_pcache*, unsigned key, int createFlag);

  9143.   void (*xUnpin)(sqlite3_pcache*, sqlite3_pcache_page*, int discard);

  9144.   void (*xRekey)(sqlite3_pcache*, sqlite3_pcache_page*, 

  9145.       unsigned oldKey, unsigned newKey);

  9146.   void (*xTruncate)(sqlite3_pcache*, unsigned iLimit);

  9147.   void (*xDestroy)(sqlite3_pcache*);

  9148.   void (*xShrink)(sqlite3_pcache*);

  9149. };

  9150. 

  9151. /*

  9152. ** This is the obsolete pcache_methods object that has now been replaced

  9153. ** by sqlite3_pcache_methods2.  This object is not used by SQLite.  It is

  9154. ** retained in the header file for backwards compatibility only.

  9155. */

  9156. typedef struct sqlite3_pcache_methods sqlite3_pcache_methods;

  9157. struct sqlite3_pcache_methods {

  9158.   void *pArg;

  9159.   int (*xInit)(void*);

  9160.   void (*xShutdown)(void*);

  9161.   sqlite3_pcache *(*xCreate)(int szPage, int bPurgeable);

  9162.   void (*xCachesize)(sqlite3_pcache*, int nCachesize);

  9163.   int (*xPagecount)(sqlite3_pcache*);

  9164.   void *(*xFetch)(sqlite3_pcache*, unsigned key, int createFlag);

  9165.   void (*xUnpin)(sqlite3_pcache*, void*, int discard);

  9166.   void (*xRekey)(sqlite3_pcache*, void*, unsigned oldKey, unsigned newKey);

  9167.   void (*xTruncate)(sqlite3_pcache*, unsigned iLimit);

  9168.   void (*xDestroy)(sqlite3_pcache*);

  9169. };

  9170. 

  9171. 

  9172. /*

  9173. ** CAPI3REF: Online Backup Object

  9174. **

  9175. ** The sqlite3_backup object records state information about an ongoing

  9176. ** online backup operation.  ^The sqlite3_backup object is created by

  9177. ** a call to [sqlite3_backup_init()] and is destroyed by a call to

  9178. ** [sqlite3_backup_finish()].

  9179. **

  9180. ** See Also: [Using the SQLite Online Backup API]

  9181. */

  9182. typedef struct sqlite3_backup sqlite3_backup;

  9183. 

  9184. /*

  9185. ** CAPI3REF: Online Backup API.

  9186. **

  9187. ** The backup API copies the content of one database into another.

  9188. ** It is useful either for creating backups of databases or

  9189. ** for copying in-memory databases to or from persistent files. 

  9190. **

  9191. ** See Also: [Using the SQLite Online Backup API]

  9192. **

  9193. ** ^SQLite holds a write transaction open on the destination database file

  9194. ** for the duration of the backup operation.

  9195. ** ^The source database is read-locked only while it is being read;

  9196. ** it is not locked continuously for the entire backup operation.

  9197. ** ^Thus, the backup may be performed on a live source database without

  9198. ** preventing other database connections from

  9199. ** reading or writing to the source database while the backup is underway.

  9200. ** 

  9201. ** ^(To perform a backup operation: 

  9202. **   <ol>

  9203. **     <li><b>sqlite3_backup_init()</b> is called once to initialize the

  9204. **         backup, 

  9205. **     <li><b>sqlite3_backup_step()</b> is called one or more times to transfer 

  9206. **         the data between the two databases, and finally

  9207. **     <li><b>sqlite3_backup_finish()</b> is called to release all resources 

  9208. **         associated with the backup operation. 

  9209. **   </ol>)^

  9210. ** There should be exactly one call to sqlite3_backup_finish() for each

  9211. ** successful call to sqlite3_backup_init().

  9212. **

  9213. ** [[sqlite3_backup_init()]] <b>sqlite3_backup_init()</b>

  9214. **

  9215. ** ^The D and N arguments to sqlite3_backup_init(D,N,S,M) are the 

  9216. ** [database connection] associated with the destination database 

  9217. ** and the database name, respectively.

  9218. ** ^The database name is "main" for the main database, "temp" for the

  9219. ** temporary database, or the name specified after the AS keyword in

  9220. ** an [ATTACH] statement for an attached database.

  9221. ** ^The S and M arguments passed to 

  9222. ** sqlite3_backup_init(D,N,S,M) identify the [database connection]

  9223. ** and database name of the source database, respectively.

  9224. ** ^The source and destination [database connections] (parameters S and D)

  9225. ** must be different or else sqlite3_backup_init(D,N,S,M) will fail with

  9226. ** an error.

  9227. **

  9228. ** ^A call to sqlite3_backup_init() will fail, returning NULL, if 

  9229. ** there is already a read or read-write transaction open on the 

  9230. ** destination database.

  9231. **

  9232. ** ^If an error occurs within sqlite3_backup_init(D,N,S,M), then NULL is

  9233. ** returned and an error code and error message are stored in the

  9234. ** destination [database connection] D.

  9235. ** ^The error code and message for the failed call to sqlite3_backup_init()

  9236. ** can be retrieved using the [sqlite3_errcode()], [sqlite3_errmsg()], and/or

  9237. ** [sqlite3_errmsg16()] functions.

  9238. ** ^A successful call to sqlite3_backup_init() returns a pointer to an

  9239. ** [sqlite3_backup] object.

  9240. ** ^The [sqlite3_backup] object may be used with the sqlite3_backup_step() and

  9241. ** sqlite3_backup_finish() functions to perform the specified backup 

  9242. ** operation.

  9243. **

  9244. ** [[sqlite3_backup_step()]] <b>sqlite3_backup_step()</b>

  9245. **

  9246. ** ^Function sqlite3_backup_step(B,N) will copy up to N pages between 

  9247. ** the source and destination databases specified by [sqlite3_backup] object B.

  9248. ** ^If N is negative, all remaining source pages are copied. 

  9249. ** ^If sqlite3_backup_step(B,N) successfully copies N pages and there

  9250. ** are still more pages to be copied, then the function returns [SQLITE_OK].

  9251. ** ^If sqlite3_backup_step(B,N) successfully finishes copying all pages

  9252. ** from source to destination, then it returns [SQLITE_DONE].

  9253. ** ^If an error occurs while running sqlite3_backup_step(B,N),

  9254. ** then an [error code] is returned. ^As well as [SQLITE_OK] and

  9255. ** [SQLITE_DONE], a call to sqlite3_backup_step() may return [SQLITE_READONLY],

  9256. ** [SQLITE_NOMEM], [SQLITE_BUSY], [SQLITE_LOCKED], or an

  9257. ** [SQLITE_IOERR_ACCESS | SQLITE_IOERR_XXX] extended error code.

  9258. **

  9259. ** ^(The sqlite3_backup_step() might return [SQLITE_READONLY] if

  9260. ** <ol>

  9261. ** <li> the destination database was opened read-only, or

  9262. ** <li> the destination database is using write-ahead-log journaling

  9263. ** and the destination and source page sizes differ, or

  9264. ** <li> the destination database is an in-memory database and the

  9265. ** destination and source page sizes differ.

  9266. ** </ol>)^

  9267. **

  9268. ** ^If sqlite3_backup_step() cannot obtain a required file-system lock, then

  9269. ** the [sqlite3_busy_handler | busy-handler function]

  9270. ** is invoked (if one is specified). ^If the 

  9271. ** busy-handler returns non-zero before the lock is available, then 

  9272. ** [SQLITE_BUSY] is returned to the caller. ^In this case the call to

  9273. ** sqlite3_backup_step() can be retried later. ^If the source

  9274. ** [database connection]

  9275. ** is being used to write to the source database when sqlite3_backup_step()

  9276. ** is called, then [SQLITE_LOCKED] is returned immediately. ^Again, in this

  9277. ** case the call to sqlite3_backup_step() can be retried later on. ^(If

  9278. ** [SQLITE_IOERR_ACCESS | SQLITE_IOERR_XXX], [SQLITE_NOMEM], or

  9279. ** [SQLITE_READONLY] is returned, then 

  9280. ** there is no point in retrying the call to sqlite3_backup_step(). These 

  9281. ** errors are considered fatal.)^  The application must accept 

  9282. ** that the backup operation has failed and pass the backup operation handle 

  9283. ** to the sqlite3_backup_finish() to release associated resources.

  9284. **

  9285. ** ^The first call to sqlite3_backup_step() obtains an exclusive lock

  9286. ** on the destination file. ^The exclusive lock is not released until either 

  9287. ** sqlite3_backup_finish() is called or the backup operation is complete 

  9288. ** and sqlite3_backup_step() returns [SQLITE_DONE].  ^Every call to

  9289. ** sqlite3_backup_step() obtains a [shared lock] on the source database that

  9290. ** lasts for the duration of the sqlite3_backup_step() call.

  9291. ** ^Because the source database is not locked between calls to

  9292. ** sqlite3_backup_step(), the source database may be modified mid-way

  9293. ** through the backup process.  ^If the source database is modified by an

  9294. ** external process or via a database connection other than the one being

  9295. ** used by the backup operation, then the backup will be automatically

  9296. ** restarted by the next call to sqlite3_backup_step(). ^If the source 

  9297. ** database is modified by the using the same database connection as is used

  9298. ** by the backup operation, then the backup database is automatically

  9299. ** updated at the same time.

  9300. **

  9301. ** [[sqlite3_backup_finish()]] <b>sqlite3_backup_finish()</b>

  9302. **

  9303. ** When sqlite3_backup_step() has returned [SQLITE_DONE], or when the 

  9304. ** application wishes to abandon the backup operation, the application

  9305. ** should destroy the [sqlite3_backup] by passing it to sqlite3_backup_finish().

  9306. ** ^The sqlite3_backup_finish() interfaces releases all

  9307. ** resources associated with the [sqlite3_backup] object. 

  9308. ** ^If sqlite3_backup_step() has not yet returned [SQLITE_DONE], then any

  9309. ** active write-transaction on the destination database is rolled back.

  9310. ** The [sqlite3_backup] object is invalid

  9311. ** and may not be used following a call to sqlite3_backup_finish().

  9312. **

  9313. ** ^The value returned by sqlite3_backup_finish is [SQLITE_OK] if no

  9314. ** sqlite3_backup_step() errors occurred, regardless or whether or not

  9315. ** sqlite3_backup_step() completed.

  9316. ** ^If an out-of-memory condition or IO error occurred during any prior

  9317. ** sqlite3_backup_step() call on the same [sqlite3_backup] object, then

  9318. ** sqlite3_backup_finish() returns the corresponding [error code].

  9319. **

  9320. ** ^A return of [SQLITE_BUSY] or [SQLITE_LOCKED] from sqlite3_backup_step()

  9321. ** is not a permanent error and does not affect the return value of

  9322. ** sqlite3_backup_finish().

  9323. **

  9324. ** [[sqlite3_backup_remaining()]] [[sqlite3_backup_pagecount()]]

  9325. ** <b>sqlite3_backup_remaining() and sqlite3_backup_pagecount()</b>

  9326. **

  9327. ** ^The sqlite3_backup_remaining() routine returns the number of pages still

  9328. ** to be backed up at the conclusion of the most recent sqlite3_backup_step().

  9329. ** ^The sqlite3_backup_pagecount() routine returns the total number of pages

  9330. ** in the source database at the conclusion of the most recent

  9331. ** sqlite3_backup_step().

  9332. ** ^(The values returned by these functions are only updated by

  9333. ** sqlite3_backup_step(). If the source database is modified in a way that

  9334. ** changes the size of the source database or the number of pages remaining,

  9335. ** those changes are not reflected in the output of sqlite3_backup_pagecount()

  9336. ** and sqlite3_backup_remaining() until after the next

  9337. ** sqlite3_backup_step().)^

  9338. **

  9339. ** <b>Concurrent Usage of Database Handles</b>

  9340. **

  9341. ** ^The source [database connection] may be used by the application for other

  9342. ** purposes while a backup operation is underway or being initialized.

  9343. ** ^If SQLite is compiled and configured to support threadsafe database

  9344. ** connections, then the source database connection may be used concurrently

  9345. ** from within other threads.

  9346. **

  9347. ** However, the application must guarantee that the destination 

  9348. ** [database connection] is not passed to any other API (by any thread) after 

  9349. ** sqlite3_backup_init() is called and before the corresponding call to

  9350. ** sqlite3_backup_finish().  SQLite does not currently check to see

  9351. ** if the application incorrectly accesses the destination [database connection]

  9352. ** and so no error code is reported, but the operations may malfunction

  9353. ** nevertheless.  Use of the destination database connection while a

  9354. ** backup is in progress might also also cause a mutex deadlock.

  9355. **

  9356. ** If running in [shared cache mode], the application must

  9357. ** guarantee that the shared cache used by the destination database

  9358. ** is not accessed while the backup is running. In practice this means

  9359. ** that the application must guarantee that the disk file being 

  9360. ** backed up to is not accessed by any connection within the process,

  9361. ** not just the specific connection that was passed to sqlite3_backup_init().

  9362. **

  9363. ** The [sqlite3_backup] object itself is partially threadsafe. Multiple 

  9364. ** threads may safely make multiple concurrent calls to sqlite3_backup_step().

  9365. ** However, the sqlite3_backup_remaining() and sqlite3_backup_pagecount()

  9366. ** APIs are not strictly speaking threadsafe. If they are invoked at the

  9367. ** same time as another thread is invoking sqlite3_backup_step() it is

  9368. ** possible that they return invalid values.

  9369. */

  9370. SQLITE_API sqlite3_backup *sqlite3_backup_init(

  9371.   sqlite3 *pDest,                        /* Destination database handle */

  9372.   const char *zDestName,                 /* Destination database name */

  9373.   sqlite3 *pSource,                      /* Source database handle */

  9374.   const char *zSourceName                /* Source database name */

  9375. );

  9376. SQLITE_API int sqlite3_backup_step(sqlite3_backup *p, int nPage);

  9377. SQLITE_API int sqlite3_backup_finish(sqlite3_backup *p);

  9378. SQLITE_API int sqlite3_backup_remaining(sqlite3_backup *p);

  9379. SQLITE_API int sqlite3_backup_pagecount(sqlite3_backup *p);

  9380. 

  9381. /*

  9382. ** CAPI3REF: Unlock Notification

  9383. ** METHOD: sqlite3

  9384. **

  9385. ** ^When running in shared-cache mode, a database operation may fail with

  9386. ** an [SQLITE_LOCKED] error if the required locks on the shared-cache or

  9387. ** individual tables within the shared-cache cannot be obtained. See

  9388. ** [SQLite Shared-Cache Mode] for a description of shared-cache locking. 

  9389. ** ^This API may be used to register a callback that SQLite will invoke 

  9390. ** when the connection currently holding the required lock relinquishes it.

  9391. ** ^This API is only available if the library was compiled with the

  9392. ** [SQLITE_ENABLE_UNLOCK_NOTIFY] C-preprocessor symbol defined.

  9393. **

  9394. ** See Also: [Using the SQLite Unlock Notification Feature].

  9395. **

  9396. ** ^Shared-cache locks are released when a database connection concludes

  9397. ** its current transaction, either by committing it or rolling it back. 

  9398. **

  9399. ** ^When a connection (known as the blocked connection) fails to obtain a

  9400. ** shared-cache lock and SQLITE_LOCKED is returned to the caller, the

  9401. ** identity of the database connection (the blocking connection) that

  9402. ** has locked the required resource is stored internally. ^After an 

  9403. ** application receives an SQLITE_LOCKED error, it may call the

  9404. ** sqlite3_unlock_notify() method with the blocked connection handle as 

  9405. ** the first argument to register for a callback that will be invoked

  9406. ** when the blocking connections current transaction is concluded. ^The

  9407. ** callback is invoked from within the [sqlite3_step] or [sqlite3_close]

  9408. ** call that concludes the blocking connections transaction.

  9409. **

  9410. ** ^(If sqlite3_unlock_notify() is called in a multi-threaded application,

  9411. ** there is a chance that the blocking connection will have already

  9412. ** concluded its transaction by the time sqlite3_unlock_notify() is invoked.

  9413. ** If this happens, then the specified callback is invoked immediately,

  9414. ** from within the call to sqlite3_unlock_notify().)^

  9415. **

  9416. ** ^If the blocked connection is attempting to obtain a write-lock on a

  9417. ** shared-cache table, and more than one other connection currently holds

  9418. ** a read-lock on the same table, then SQLite arbitrarily selects one of 

  9419. ** the other connections to use as the blocking connection.

  9420. **

  9421. ** ^(There may be at most one unlock-notify callback registered by a 

  9422. ** blocked connection. If sqlite3_unlock_notify() is called when the

  9423. ** blocked connection already has a registered unlock-notify callback,

  9424. ** then the new callback replaces the old.)^ ^If sqlite3_unlock_notify() is

  9425. ** called with a NULL pointer as its second argument, then any existing

  9426. ** unlock-notify callback is canceled. ^The blocked connections 

  9427. ** unlock-notify callback may also be canceled by closing the blocked

  9428. ** connection using [sqlite3_close()].

  9429. **

  9430. ** The unlock-notify callback is not reentrant. If an application invokes

  9431. ** any sqlite3_xxx API functions from within an unlock-notify callback, a

  9432. ** crash or deadlock may be the result.

  9433. **

  9434. ** ^Unless deadlock is detected (see below), sqlite3_unlock_notify() always

  9435. ** returns SQLITE_OK.

  9436. **

  9437. ** <b>Callback Invocation Details</b>

  9438. **

  9439. ** When an unlock-notify callback is registered, the application provides a 

  9440. ** single void* pointer that is passed to the callback when it is invoked.

  9441. ** However, the signature of the callback function allows SQLite to pass

  9442. ** it an array of void* context pointers. The first argument passed to

  9443. ** an unlock-notify callback is a pointer to an array of void* pointers,

  9444. ** and the second is the number of entries in the array.

  9445. **

  9446. ** When a blocking connections transaction is concluded, there may be

  9447. ** more than one blocked connection that has registered for an unlock-notify

  9448. ** callback. ^If two or more such blocked connections have specified the

  9449. ** same callback function, then instead of invoking the callback function

  9450. ** multiple times, it is invoked once with the set of void* context pointers

  9451. ** specified by the blocked connections bundled together into an array.

  9452. ** This gives the application an opportunity to prioritize any actions 

  9453. ** related to the set of unblocked database connections.

  9454. **

  9455. ** <b>Deadlock Detection</b>

  9456. **

  9457. ** Assuming that after registering for an unlock-notify callback a 

  9458. ** database waits for the callback to be issued before taking any further

  9459. ** action (a reasonable assumption), then using this API may cause the

  9460. ** application to deadlock. For example, if connection X is waiting for

  9461. ** connection Y's transaction to be concluded, and similarly connection

  9462. ** Y is waiting on connection X's transaction, then neither connection

  9463. ** will proceed and the system may remain deadlocked indefinitely.

  9464. **

  9465. ** To avoid this scenario, the sqlite3_unlock_notify() performs deadlock

  9466. ** detection. ^If a given call to sqlite3_unlock_notify() would put the

  9467. ** system in a deadlocked state, then SQLITE_LOCKED is returned and no

  9468. ** unlock-notify callback is registered. The system is said to be in

  9469. ** a deadlocked state if connection A has registered for an unlock-notify

  9470. ** callback on the conclusion of connection B's transaction, and connection

  9471. ** B has itself registered for an unlock-notify callback when connection

  9472. ** A's transaction is concluded. ^Indirect deadlock is also detected, so

  9473. ** the system is also considered to be deadlocked if connection B has

  9474. ** registered for an unlock-notify callback on the conclusion of connection

  9475. ** C's transaction, where connection C is waiting on connection A. ^Any

  9476. ** number of levels of indirection are allowed.

  9477. **

  9478. ** <b>The "DROP TABLE" Exception</b>

  9479. **

  9480. ** When a call to [sqlite3_step()] returns SQLITE_LOCKED, it is almost 

  9481. ** always appropriate to call sqlite3_unlock_notify(). There is however,

  9482. ** one exception. When executing a "DROP TABLE" or "DROP INDEX" statement,

  9483. ** SQLite checks if there are any currently executing SELECT statements

  9484. ** that belong to the same connection. If there are, SQLITE_LOCKED is

  9485. ** returned. In this case there is no "blocking connection", so invoking

  9486. ** sqlite3_unlock_notify() results in the unlock-notify callback being

  9487. ** invoked immediately. If the application then re-attempts the "DROP TABLE"

  9488. ** or "DROP INDEX" query, an infinite loop might be the result.

  9489. **

  9490. ** One way around this problem is to check the extended error code returned

  9491. ** by an sqlite3_step() call. ^(If there is a blocking connection, then the

  9492. ** extended error code is set to SQLITE_LOCKED_SHAREDCACHE. Otherwise, in

  9493. ** the special "DROP TABLE/INDEX" case, the extended error code is just 

  9494. ** SQLITE_LOCKED.)^

  9495. */

  9496. SQLITE_API int sqlite3_unlock_notify(

  9497.   sqlite3 *pBlocked,                          /* Waiting connection */

  9498.   void (*xNotify)(void **apArg, int nArg),    /* Callback function to invoke */

  9499.   void *pNotifyArg                            /* Argument to pass to xNotify */

  9500. );

  9501. 

  9502. 

  9503. /*

  9504. ** CAPI3REF: String Comparison

  9505. **

  9506. ** ^The [sqlite3_stricmp()] and [sqlite3_strnicmp()] APIs allow applications

  9507. ** and extensions to compare the contents of two buffers containing UTF-8

  9508. ** strings in a case-independent fashion, using the same definition of "case

  9509. ** independence" that SQLite uses internally when comparing identifiers.

  9510. */

  9511. SQLITE_API int sqlite3_stricmp(const char *, const char *);

  9512. SQLITE_API int sqlite3_strnicmp(const char *, const char *, int);

  9513. 

  9514. /*

  9515. ** CAPI3REF: String Globbing

  9516. *

  9517. ** ^The [sqlite3_strglob(P,X)] interface returns zero if and only if

  9518. ** string X matches the [GLOB] pattern P.

  9519. ** ^The definition of [GLOB] pattern matching used in

  9520. ** [sqlite3_strglob(P,X)] is the same as for the "X GLOB P" operator in the

  9521. ** SQL dialect understood by SQLite.  ^The [sqlite3_strglob(P,X)] function

  9522. ** is case sensitive.

  9523. **

  9524. ** Note that this routine returns zero on a match and non-zero if the strings

  9525. ** do not match, the same as [sqlite3_stricmp()] and [sqlite3_strnicmp()].

  9526. **

  9527. ** See also: [sqlite3_strlike()].

  9528. */

  9529. SQLITE_API int sqlite3_strglob(const char *zGlob, const char *zStr);

  9530. 

  9531. /*

  9532. ** CAPI3REF: String LIKE Matching

  9533. *

  9534. ** ^The [sqlite3_strlike(P,X,E)] interface returns zero if and only if

  9535. ** string X matches the [LIKE] pattern P with escape character E.

  9536. ** ^The definition of [LIKE] pattern matching used in

  9537. ** [sqlite3_strlike(P,X,E)] is the same as for the "X LIKE P ESCAPE E"

  9538. ** operator in the SQL dialect understood by SQLite.  ^For "X LIKE P" without

  9539. ** the ESCAPE clause, set the E parameter of [sqlite3_strlike(P,X,E)] to 0.

  9540. ** ^As with the LIKE operator, the [sqlite3_strlike(P,X,E)] function is case

  9541. ** insensitive - equivalent upper and lower case ASCII characters match

  9542. ** one another.

  9543. **

  9544. ** ^The [sqlite3_strlike(P,X,E)] function matches Unicode characters, though

  9545. ** only ASCII characters are case folded.

  9546. **

  9547. ** Note that this routine returns zero on a match and non-zero if the strings

  9548. ** do not match, the same as [sqlite3_stricmp()] and [sqlite3_strnicmp()].

  9549. **

  9550. ** See also: [sqlite3_strglob()].

  9551. */

  9552. SQLITE_API int sqlite3_strlike(const char *zGlob, const char *zStr, unsigned int cEsc);

  9553. 

  9554. /*

  9555. ** CAPI3REF: Error Logging Interface

  9556. **

  9557. ** ^The [sqlite3_log()] interface writes a message into the [error log]

  9558. ** established by the [SQLITE_CONFIG_LOG] option to [sqlite3_config()].

  9559. ** ^If logging is enabled, the zFormat string and subsequent arguments are

  9560. ** used with [sqlite3_snprintf()] to generate the final output string.

  9561. **

  9562. ** The sqlite3_log() interface is intended for use by extensions such as

  9563. ** virtual tables, collating functions, and SQL functions.  While there is

  9564. ** nothing to prevent an application from calling sqlite3_log(), doing so

  9565. ** is considered bad form.

  9566. **

  9567. ** The zFormat string must not be NULL.

  9568. **

  9569. ** To avoid deadlocks and other threading problems, the sqlite3_log() routine

  9570. ** will not use dynamically allocated memory.  The log message is stored in

  9571. ** a fixed-length buffer on the stack.  If the log message is longer than

  9572. ** a few hundred characters, it will be truncated to the length of the

  9573. ** buffer.

  9574. */

  9575. SQLITE_API void sqlite3_log(int iErrCode, const char *zFormat, ...);

  9576. 

  9577. /*

  9578. ** CAPI3REF: Write-Ahead Log Commit Hook

  9579. ** METHOD: sqlite3

  9580. **

  9581. ** ^The [sqlite3_wal_hook()] function is used to register a callback that

  9582. ** is invoked each time data is committed to a database in wal mode.

  9583. **

  9584. ** ^(The callback is invoked by SQLite after the commit has taken place and 

  9585. ** the associated write-lock on the database released)^, so the implementation 

  9586. ** may read, write or [checkpoint] the database as required.

  9587. **

  9588. ** ^The first parameter passed to the callback function when it is invoked

  9589. ** is a copy of the third parameter passed to sqlite3_wal_hook() when

  9590. ** registering the callback. ^The second is a copy of the database handle.

  9591. ** ^The third parameter is the name of the database that was written to -

  9592. ** either "main" or the name of an [ATTACH]-ed database. ^The fourth parameter

  9593. ** is the number of pages currently in the write-ahead log file,

  9594. ** including those that were just committed.

  9595. **

  9596. ** The callback function should normally return [SQLITE_OK].  ^If an error

  9597. ** code is returned, that error will propagate back up through the

  9598. ** SQLite code base to cause the statement that provoked the callback

  9599. ** to report an error, though the commit will have still occurred. If the

  9600. ** callback returns [SQLITE_ROW] or [SQLITE_DONE], or if it returns a value

  9601. ** that does not correspond to any valid SQLite error code, the results

  9602. ** are undefined.

  9603. **

  9604. ** A single database handle may have at most a single write-ahead log callback 

  9605. ** registered at one time. ^Calling [sqlite3_wal_hook()] replaces any

  9606. ** previously registered write-ahead log callback. ^Note that the

  9607. ** [sqlite3_wal_autocheckpoint()] interface and the

  9608. ** [wal_autocheckpoint pragma] both invoke [sqlite3_wal_hook()] and will

  9609. ** overwrite any prior [sqlite3_wal_hook()] settings.

  9610. */

  9611. SQLITE_API void *sqlite3_wal_hook(

  9612.   sqlite3*, 

  9613.   int(*)(void *,sqlite3*,const char*,int),

  9614.   void*

  9615. );

  9616. 

  9617. /*

  9618. ** CAPI3REF: Configure an auto-checkpoint

  9619. ** METHOD: sqlite3

  9620. **

  9621. ** ^The [sqlite3_wal_autocheckpoint(D,N)] is a wrapper around

  9622. ** [sqlite3_wal_hook()] that causes any database on [database connection] D

  9623. ** to automatically [checkpoint]

  9624. ** after committing a transaction if there are N or

  9625. ** more frames in the [write-ahead log] file.  ^Passing zero or 

  9626. ** a negative value as the nFrame parameter disables automatic

  9627. ** checkpoints entirely.

  9628. **

  9629. ** ^The callback registered by this function replaces any existing callback

  9630. ** registered using [sqlite3_wal_hook()].  ^Likewise, registering a callback

  9631. ** using [sqlite3_wal_hook()] disables the automatic checkpoint mechanism

  9632. ** configured by this function.

  9633. **

  9634. ** ^The [wal_autocheckpoint pragma] can be used to invoke this interface

  9635. ** from SQL.

  9636. **

  9637. ** ^Checkpoints initiated by this mechanism are

  9638. ** [sqlite3_wal_checkpoint_v2|PASSIVE].

  9639. **

  9640. ** ^Every new [database connection] defaults to having the auto-checkpoint

  9641. ** enabled with a threshold of 1000 or [SQLITE_DEFAULT_WAL_AUTOCHECKPOINT]

  9642. ** pages.  The use of this interface

  9643. ** is only necessary if the default setting is found to be suboptimal

  9644. ** for a particular application.

  9645. */

  9646. SQLITE_API int sqlite3_wal_autocheckpoint(sqlite3 *db, int N);

  9647. 

  9648. /*

  9649. ** CAPI3REF: Checkpoint a database

  9650. ** METHOD: sqlite3

  9651. **

  9652. ** ^(The sqlite3_wal_checkpoint(D,X) is equivalent to

  9653. ** [sqlite3_wal_checkpoint_v2](D,X,[SQLITE_CHECKPOINT_PASSIVE],0,0).)^

  9654. **

  9655. ** In brief, sqlite3_wal_checkpoint(D,X) causes the content in the 

  9656. ** [write-ahead log] for database X on [database connection] D to be

  9657. ** transferred into the database file and for the write-ahead log to

  9658. ** be reset.  See the [checkpointing] documentation for addition

  9659. ** information.

  9660. **

  9661. ** This interface used to be the only way to cause a checkpoint to

  9662. ** occur.  But then the newer and more powerful [sqlite3_wal_checkpoint_v2()]

  9663. ** interface was added.  This interface is retained for backwards

  9664. ** compatibility and as a convenience for applications that need to manually

  9665. ** start a callback but which do not need the full power (and corresponding

  9666. ** complication) of [sqlite3_wal_checkpoint_v2()].

  9667. */

  9668. SQLITE_API int sqlite3_wal_checkpoint(sqlite3 *db, const char *zDb);

  9669. 

  9670. /*

  9671. ** CAPI3REF: Checkpoint a database

  9672. ** METHOD: sqlite3

  9673. **

  9674. ** ^(The sqlite3_wal_checkpoint_v2(D,X,M,L,C) interface runs a checkpoint

  9675. ** operation on database X of [database connection] D in mode M.  Status

  9676. ** information is written back into integers pointed to by L and C.)^

  9677. ** ^(The M parameter must be a valid [checkpoint mode]:)^

  9678. **

  9679. ** <dl>

  9680. ** <dt>SQLITE_CHECKPOINT_PASSIVE<dd>

  9681. **   ^Checkpoint as many frames as possible without waiting for any database 

  9682. **   readers or writers to finish, then sync the database file if all frames 

  9683. **   in the log were checkpointed. ^The [busy-handler callback]

  9684. **   is never invoked in the SQLITE_CHECKPOINT_PASSIVE mode.  

  9685. **   ^On the other hand, passive mode might leave the checkpoint unfinished

  9686. **   if there are concurrent readers or writers.

  9687. **

  9688. ** <dt>SQLITE_CHECKPOINT_FULL<dd>

  9689. **   ^This mode blocks (it invokes the

  9690. **   [sqlite3_busy_handler|busy-handler callback]) until there is no

  9691. **   database writer and all readers are reading from the most recent database

  9692. **   snapshot. ^It then checkpoints all frames in the log file and syncs the

  9693. **   database file. ^This mode blocks new database writers while it is pending,

  9694. **   but new database readers are allowed to continue unimpeded.

  9695. **

  9696. ** <dt>SQLITE_CHECKPOINT_RESTART<dd>

  9697. **   ^This mode works the same way as SQLITE_CHECKPOINT_FULL with the addition

  9698. **   that after checkpointing the log file it blocks (calls the 

  9699. **   [busy-handler callback])

  9700. **   until all readers are reading from the database file only. ^This ensures 

  9701. **   that the next writer will restart the log file from the beginning.

  9702. **   ^Like SQLITE_CHECKPOINT_FULL, this mode blocks new

  9703. **   database writer attempts while it is pending, but does not impede readers.

  9704. **

  9705. ** <dt>SQLITE_CHECKPOINT_TRUNCATE<dd>

  9706. **   ^This mode works the same way as SQLITE_CHECKPOINT_RESTART with the

  9707. **   addition that it also truncates the log file to zero bytes just prior

  9708. **   to a successful return.

  9709. ** </dl>

  9710. **

  9711. ** ^If pnLog is not NULL, then *pnLog is set to the total number of frames in

  9712. ** the log file or to -1 if the checkpoint could not run because

  9713. ** of an error or because the database is not in [WAL mode]. ^If pnCkpt is not

  9714. ** NULL,then *pnCkpt is set to the total number of checkpointed frames in the

  9715. ** log file (including any that were already checkpointed before the function

  9716. ** was called) or to -1 if the checkpoint could not run due to an error or

  9717. ** because the database is not in WAL mode. ^Note that upon successful

  9718. ** completion of an SQLITE_CHECKPOINT_TRUNCATE, the log file will have been

  9719. ** truncated to zero bytes and so both *pnLog and *pnCkpt will be set to zero.

  9720. **

  9721. ** ^All calls obtain an exclusive "checkpoint" lock on the database file. ^If

  9722. ** any other process is running a checkpoint operation at the same time, the 

  9723. ** lock cannot be obtained and SQLITE_BUSY is returned. ^Even if there is a 

  9724. ** busy-handler configured, it will not be invoked in this case.

  9725. **

  9726. ** ^The SQLITE_CHECKPOINT_FULL, RESTART and TRUNCATE modes also obtain the 

  9727. ** exclusive "writer" lock on the database file. ^If the writer lock cannot be

  9728. ** obtained immediately, and a busy-handler is configured, it is invoked and

  9729. ** the writer lock retried until either the busy-handler returns 0 or the lock

  9730. ** is successfully obtained. ^The busy-handler is also invoked while waiting for

  9731. ** database readers as described above. ^If the busy-handler returns 0 before

  9732. ** the writer lock is obtained or while waiting for database readers, the

  9733. ** checkpoint operation proceeds from that point in the same way as 

  9734. ** SQLITE_CHECKPOINT_PASSIVE - checkpointing as many frames as possible 

  9735. ** without blocking any further. ^SQLITE_BUSY is returned in this case.

  9736. **

  9737. ** ^If parameter zDb is NULL or points to a zero length string, then the

  9738. ** specified operation is attempted on all WAL databases [attached] to 

  9739. ** [database connection] db.  In this case the

  9740. ** values written to output parameters *pnLog and *pnCkpt are undefined. ^If 

  9741. ** an SQLITE_BUSY error is encountered when processing one or more of the 

  9742. ** attached WAL databases, the operation is still attempted on any remaining 

  9743. ** attached databases and SQLITE_BUSY is returned at the end. ^If any other 

  9744. ** error occurs while processing an attached database, processing is abandoned 

  9745. ** and the error code is returned to the caller immediately. ^If no error 

  9746. ** (SQLITE_BUSY or otherwise) is encountered while processing the attached 

  9747. ** databases, SQLITE_OK is returned.

  9748. **

  9749. ** ^If database zDb is the name of an attached database that is not in WAL

  9750. ** mode, SQLITE_OK is returned and both *pnLog and *pnCkpt set to -1. ^If

  9751. ** zDb is not NULL (or a zero length string) and is not the name of any

  9752. ** attached database, SQLITE_ERROR is returned to the caller.

  9753. **

  9754. ** ^Unless it returns SQLITE_MISUSE,

  9755. ** the sqlite3_wal_checkpoint_v2() interface

  9756. ** sets the error information that is queried by

  9757. ** [sqlite3_errcode()] and [sqlite3_errmsg()].

  9758. **

  9759. ** ^The [PRAGMA wal_checkpoint] command can be used to invoke this interface

  9760. ** from SQL.

  9761. */

  9762. SQLITE_API int sqlite3_wal_checkpoint_v2(

  9763.   sqlite3 *db,                    /* Database handle */

  9764.   const char *zDb,                /* Name of attached database (or NULL) */

  9765.   int eMode,                      /* SQLITE_CHECKPOINT_* value */

  9766.   int *pnLog,                     /* OUT: Size of WAL log in frames */

  9767.   int *pnCkpt                     /* OUT: Total number of frames checkpointed */

  9768. );

  9769. 

  9770. /*

  9771. ** CAPI3REF: Checkpoint Mode Values

  9772. ** KEYWORDS: {checkpoint mode}

  9773. **

  9774. ** These constants define all valid values for the "checkpoint mode" passed

  9775. ** as the third parameter to the [sqlite3_wal_checkpoint_v2()] interface.

  9776. ** See the [sqlite3_wal_checkpoint_v2()] documentation for details on the

  9777. ** meaning of each of these checkpoint modes.

  9778. */

  9779. #define SQLITE_CHECKPOINT_PASSIVE  0  /* Do as much as possible w/o blocking */

  9780. #define SQLITE_CHECKPOINT_FULL     1  /* Wait for writers, then checkpoint */

  9781. #define SQLITE_CHECKPOINT_RESTART  2  /* Like FULL but wait for for readers */

  9782. #define SQLITE_CHECKPOINT_TRUNCATE 3  /* Like RESTART but also truncate WAL */

  9783. 

  9784. /*

  9785. ** CAPI3REF: Virtual Table Interface Configuration

  9786. **

  9787. ** This function may be called by either the [xConnect] or [xCreate] method

  9788. ** of a [virtual table] implementation to configure

  9789. ** various facets of the virtual table interface.

  9790. **

  9791. ** If this interface is invoked outside the context of an xConnect or

  9792. ** xCreate virtual table method then the behavior is undefined.

  9793. **

  9794. ** At present, there is only one option that may be configured using

  9795. ** this function. (See [SQLITE_VTAB_CONSTRAINT_SUPPORT].)  Further options

  9796. ** may be added in the future.

  9797. */

  9798. SQLITE_API int sqlite3_vtab_config(sqlite3*, int op, ...);

  9799. 

  9800. /*

  9801. ** CAPI3REF: Virtual Table Configuration Options

  9802. **

  9803. ** These macros define the various options to the

  9804. ** [sqlite3_vtab_config()] interface that [virtual table] implementations

  9805. ** can use to customize and optimize their behavior.

  9806. **

  9807. ** <dl>

  9808. ** [[SQLITE_VTAB_CONSTRAINT_SUPPORT]]

  9809. ** <dt>SQLITE_VTAB_CONSTRAINT_SUPPORT

  9810. ** <dd>Calls of the form

  9811. ** [sqlite3_vtab_config](db,SQLITE_VTAB_CONSTRAINT_SUPPORT,X) are supported,

  9812. ** where X is an integer.  If X is zero, then the [virtual table] whose

  9813. ** [xCreate] or [xConnect] method invoked [sqlite3_vtab_config()] does not

  9814. ** support constraints.  In this configuration (which is the default) if

  9815. ** a call to the [xUpdate] method returns [SQLITE_CONSTRAINT], then the entire

  9816. ** statement is rolled back as if [ON CONFLICT | OR ABORT] had been

  9817. ** specified as part of the users SQL statement, regardless of the actual

  9818. ** ON CONFLICT mode specified.

  9819. **

  9820. ** If X is non-zero, then the virtual table implementation guarantees

  9821. ** that if [xUpdate] returns [SQLITE_CONSTRAINT], it will do so before

  9822. ** any modifications to internal or persistent data structures have been made.

  9823. ** If the [ON CONFLICT] mode is ABORT, FAIL, IGNORE or ROLLBACK, SQLite 

  9824. ** is able to roll back a statement or database transaction, and abandon

  9825. ** or continue processing the current SQL statement as appropriate. 

  9826. ** If the ON CONFLICT mode is REPLACE and the [xUpdate] method returns

  9827. ** [SQLITE_CONSTRAINT], SQLite handles this as if the ON CONFLICT mode

  9828. ** had been ABORT.

  9829. **

  9830. ** Virtual table implementations that are required to handle OR REPLACE

  9831. ** must do so within the [xUpdate] method. If a call to the 

  9832. ** [sqlite3_vtab_on_conflict()] function indicates that the current ON 

  9833. ** CONFLICT policy is REPLACE, the virtual table implementation should 

  9834. ** silently replace the appropriate rows within the xUpdate callback and

  9835. ** return SQLITE_OK. Or, if this is not possible, it may return

  9836. ** SQLITE_CONSTRAINT, in which case SQLite falls back to OR ABORT 

  9837. ** constraint handling.

  9838. ** </dl>

  9839. */

  9840. #define SQLITE_VTAB_CONSTRAINT_SUPPORT 1

  9841. 

  9842. /*

  9843. ** CAPI3REF: Determine The Virtual Table Conflict Policy

  9844. **

  9845. ** This function may only be called from within a call to the [xUpdate] method

  9846. ** of a [virtual table] implementation for an INSERT or UPDATE operation. ^The

  9847. ** value returned is one of [SQLITE_ROLLBACK], [SQLITE_IGNORE], [SQLITE_FAIL],

  9848. ** [SQLITE_ABORT], or [SQLITE_REPLACE], according to the [ON CONFLICT] mode

  9849. ** of the SQL statement that triggered the call to the [xUpdate] method of the

  9850. ** [virtual table].

  9851. */

  9852. SQLITE_API int sqlite3_vtab_on_conflict(sqlite3 *);

  9853. 

  9854. /*

  9855. ** CAPI3REF: Determine If Virtual Table Column Access Is For UPDATE

  9856. **

  9857. ** If the sqlite3_vtab_nochange(X) routine is called within the [xColumn]

  9858. ** method of a [virtual table], then it returns true if and only if the

  9859. ** column is being fetched as part of an UPDATE operation during which the

  9860. ** column value will not change.  Applications might use this to substitute

  9861. ** a return value that is less expensive to compute and that the corresponding

  9862. ** [xUpdate] method understands as a "no-change" value.

  9863. **

  9864. ** If the [xColumn] method calls sqlite3_vtab_nochange() and finds that

  9865. ** the column is not changed by the UPDATE statement, then the xColumn

  9866. ** method can optionally return without setting a result, without calling

  9867. ** any of the [sqlite3_result_int|sqlite3_result_xxxxx() interfaces].

  9868. ** In that case, [sqlite3_value_nochange(X)] will return true for the

  9869. ** same column in the [xUpdate] method.

  9870. */

  9871. SQLITE_API int sqlite3_vtab_nochange(sqlite3_context*);

  9872. 

  9873. /*

  9874. ** CAPI3REF: Determine The Collation For a Virtual Table Constraint

  9875. **

  9876. ** This function may only be called from within a call to the [xBestIndex]

  9877. ** method of a [virtual table]. 

  9878. **

  9879. ** The first argument must be the sqlite3_index_info object that is the

  9880. ** first parameter to the xBestIndex() method. The second argument must be

  9881. ** an index into the aConstraint[] array belonging to the sqlite3_index_info

  9882. ** structure passed to xBestIndex. This function returns a pointer to a buffer 

  9883. ** containing the name of the collation sequence for the corresponding

  9884. ** constraint.

  9885. */

  9886. SQLITE_API SQLITE_EXPERIMENTAL const char *sqlite3_vtab_collation(sqlite3_index_info*,int);

  9887. 

  9888. /*

  9889. ** CAPI3REF: Conflict resolution modes

  9890. ** KEYWORDS: {conflict resolution mode}

  9891. **

  9892. ** These constants are returned by [sqlite3_vtab_on_conflict()] to

  9893. ** inform a [virtual table] implementation what the [ON CONFLICT] mode

  9894. ** is for the SQL statement being evaluated.

  9895. **

  9896. ** Note that the [SQLITE_IGNORE] constant is also used as a potential

  9897. ** return value from the [sqlite3_set_authorizer()] callback and that

  9898. ** [SQLITE_ABORT] is also a [result code].

  9899. */

  9900. #define SQLITE_ROLLBACK 1

  9901. /* #define SQLITE_IGNORE 2 // Also used by sqlite3_authorizer() callback */

  9902. #define SQLITE_FAIL     3

  9903. /* #define SQLITE_ABORT 4  // Also an error code */

  9904. #define SQLITE_REPLACE  5

  9905. 

  9906. /*

  9907. ** CAPI3REF: Prepared Statement Scan Status Opcodes

  9908. ** KEYWORDS: {scanstatus options}

  9909. **

  9910. ** The following constants can be used for the T parameter to the

  9911. ** [sqlite3_stmt_scanstatus(S,X,T,V)] interface.  Each constant designates a

  9912. ** different metric for sqlite3_stmt_scanstatus() to return.

  9913. **

  9914. ** When the value returned to V is a string, space to hold that string is

  9915. ** managed by the prepared statement S and will be automatically freed when

  9916. ** S is finalized.

  9917. **

  9918. ** <dl>

  9919. ** [[SQLITE_SCANSTAT_NLOOP]] <dt>SQLITE_SCANSTAT_NLOOP</dt>

  9920. ** <dd>^The [sqlite3_int64] variable pointed to by the T parameter will be

  9921. ** set to the total number of times that the X-th loop has run.</dd>

  9922. **

  9923. ** [[SQLITE_SCANSTAT_NVISIT]] <dt>SQLITE_SCANSTAT_NVISIT</dt>

  9924. ** <dd>^The [sqlite3_int64] variable pointed to by the T parameter will be set

  9925. ** to the total number of rows examined by all iterations of the X-th loop.</dd>

  9926. **

  9927. ** [[SQLITE_SCANSTAT_EST]] <dt>SQLITE_SCANSTAT_EST</dt>

  9928. ** <dd>^The "double" variable pointed to by the T parameter will be set to the

  9929. ** query planner's estimate for the average number of rows output from each

  9930. ** iteration of the X-th loop.  If the query planner's estimates was accurate,

  9931. ** then this value will approximate the quotient NVISIT/NLOOP and the

  9932. ** product of this value for all prior loops with the same SELECTID will

  9933. ** be the NLOOP value for the current loop.

  9934. **

  9935. ** [[SQLITE_SCANSTAT_NAME]] <dt>SQLITE_SCANSTAT_NAME</dt>

  9936. ** <dd>^The "const char *" variable pointed to by the T parameter will be set

  9937. ** to a zero-terminated UTF-8 string containing the name of the index or table

  9938. ** used for the X-th loop.

  9939. **

  9940. ** [[SQLITE_SCANSTAT_EXPLAIN]] <dt>SQLITE_SCANSTAT_EXPLAIN</dt>

  9941. ** <dd>^The "const char *" variable pointed to by the T parameter will be set

  9942. ** to a zero-terminated UTF-8 string containing the [EXPLAIN QUERY PLAN]

  9943. ** description for the X-th loop.

  9944. **

  9945. ** [[SQLITE_SCANSTAT_SELECTID]] <dt>SQLITE_SCANSTAT_SELECT</dt>

  9946. ** <dd>^The "int" variable pointed to by the T parameter will be set to the

  9947. ** "select-id" for the X-th loop.  The select-id identifies which query or

  9948. ** subquery the loop is part of.  The main query has a select-id of zero.

  9949. ** The select-id is the same value as is output in the first column

  9950. ** of an [EXPLAIN QUERY PLAN] query.

  9951. ** </dl>

  9952. */

  9953. #define SQLITE_SCANSTAT_NLOOP    0

  9954. #define SQLITE_SCANSTAT_NVISIT   1

  9955. #define SQLITE_SCANSTAT_EST      2

  9956. #define SQLITE_SCANSTAT_NAME     3

  9957. #define SQLITE_SCANSTAT_EXPLAIN  4

  9958. #define SQLITE_SCANSTAT_SELECTID 5

  9959. 

  9960. /*

  9961. ** CAPI3REF: Prepared Statement Scan Status

  9962. ** METHOD: sqlite3_stmt

  9963. **

  9964. ** This interface returns information about the predicted and measured

  9965. ** performance for pStmt.  Advanced applications can use this

  9966. ** interface to compare the predicted and the measured performance and

  9967. ** issue warnings and/or rerun [ANALYZE] if discrepancies are found.

  9968. **

  9969. ** Since this interface is expected to be rarely used, it is only

  9970. ** available if SQLite is compiled using the [SQLITE_ENABLE_STMT_SCANSTATUS]

  9971. ** compile-time option.

  9972. **

  9973. ** The "iScanStatusOp" parameter determines which status information to return.

  9974. ** The "iScanStatusOp" must be one of the [scanstatus options] or the behavior

  9975. ** of this interface is undefined.

  9976. ** ^The requested measurement is written into a variable pointed to by

  9977. ** the "pOut" parameter.

  9978. ** Parameter "idx" identifies the specific loop to retrieve statistics for.

  9979. ** Loops are numbered starting from zero. ^If idx is out of range - less than

  9980. ** zero or greater than or equal to the total number of loops used to implement

  9981. ** the statement - a non-zero value is returned and the variable that pOut

  9982. ** points to is unchanged.

  9983. **

  9984. ** ^Statistics might not be available for all loops in all statements. ^In cases

  9985. ** where there exist loops with no available statistics, this function behaves

  9986. ** as if the loop did not exist - it returns non-zero and leave the variable

  9987. ** that pOut points to unchanged.

  9988. **

  9989. ** See also: [sqlite3_stmt_scanstatus_reset()]

  9990. */

  9991. SQLITE_API int sqlite3_stmt_scanstatus(

  9992.   sqlite3_stmt *pStmt,      /* Prepared statement for which info desired */

  9993.   int idx,                  /* Index of loop to report on */

  9994.   int iScanStatusOp,        /* Information desired.  SQLITE_SCANSTAT_* */

  9995.   void *pOut                /* Result written here */

  9996. );     

  9997. 

  9998. /*

  9999. ** CAPI3REF: Zero Scan-Status Counters

  10000. ** METHOD: sqlite3_stmt

  10001. **

  10002. ** ^Zero all [sqlite3_stmt_scanstatus()] related event counters.

  10003. **

  10004. ** This API is only available if the library is built with pre-processor

  10005. ** symbol [SQLITE_ENABLE_STMT_SCANSTATUS] defined.

  10006. */

  10007. SQLITE_API void sqlite3_stmt_scanstatus_reset(sqlite3_stmt*);

  10008. 

  10009. /*

  10010. ** CAPI3REF: Flush caches to disk mid-transaction

  10011. **

  10012. ** ^If a write-transaction is open on [database connection] D when the

  10013. ** [sqlite3_db_cacheflush(D)] interface invoked, any dirty

  10014. ** pages in the pager-cache that are not currently in use are written out 

  10015. ** to disk. A dirty page may be in use if a database cursor created by an

  10016. ** active SQL statement is reading from it, or if it is page 1 of a database

  10017. ** file (page 1 is always "in use").  ^The [sqlite3_db_cacheflush(D)]

  10018. ** interface flushes caches for all schemas - "main", "temp", and

  10019. ** any [attached] databases.

  10020. **

  10021. ** ^If this function needs to obtain extra database locks before dirty pages 

  10022. ** can be flushed to disk, it does so. ^If those locks cannot be obtained 

  10023. ** immediately and there is a busy-handler callback configured, it is invoked

  10024. ** in the usual manner. ^If the required lock still cannot be obtained, then

  10025. ** the database is skipped and an attempt made to flush any dirty pages

  10026. ** belonging to the next (if any) database. ^If any databases are skipped

  10027. ** because locks cannot be obtained, but no other error occurs, this

  10028. ** function returns SQLITE_BUSY.

  10029. **

  10030. ** ^If any other error occurs while flushing dirty pages to disk (for

  10031. ** example an IO error or out-of-memory condition), then processing is

  10032. ** abandoned and an SQLite [error code] is returned to the caller immediately.

  10033. **

  10034. ** ^Otherwise, if no error occurs, [sqlite3_db_cacheflush()] returns SQLITE_OK.

  10035. **

  10036. ** ^This function does not set the database handle error code or message

  10037. ** returned by the [sqlite3_errcode()] and [sqlite3_errmsg()] functions.

  10038. */

  10039. SQLITE_API int sqlite3_db_cacheflush(sqlite3*);

  10040. 

  10041. /*

  10042. ** CAPI3REF: The pre-update hook.

  10043. **

  10044. ** ^These interfaces are only available if SQLite is compiled using the

  10045. ** [SQLITE_ENABLE_PREUPDATE_HOOK] compile-time option.

  10046. **

  10047. ** ^The [sqlite3_preupdate_hook()] interface registers a callback function

  10048. ** that is invoked prior to each [INSERT], [UPDATE], and [DELETE] operation

  10049. ** on a database table.

  10050. ** ^At most one preupdate hook may be registered at a time on a single

  10051. ** [database connection]; each call to [sqlite3_preupdate_hook()] overrides

  10052. ** the previous setting.

  10053. ** ^The preupdate hook is disabled by invoking [sqlite3_preupdate_hook()]

  10054. ** with a NULL pointer as the second parameter.

  10055. ** ^The third parameter to [sqlite3_preupdate_hook()] is passed through as

  10056. ** the first parameter to callbacks.

  10057. **

  10058. ** ^The preupdate hook only fires for changes to real database tables; the

  10059. ** preupdate hook is not invoked for changes to [virtual tables] or to

  10060. ** system tables like sqlite_master or sqlite_stat1.

  10061. **

  10062. ** ^The second parameter to the preupdate callback is a pointer to

  10063. ** the [database connection] that registered the preupdate hook.

  10064. ** ^The third parameter to the preupdate callback is one of the constants

  10065. ** [SQLITE_INSERT], [SQLITE_DELETE], or [SQLITE_UPDATE] to identify the

  10066. ** kind of update operation that is about to occur.

  10067. ** ^(The fourth parameter to the preupdate callback is the name of the

  10068. ** database within the database connection that is being modified.  This

  10069. ** will be "main" for the main database or "temp" for TEMP tables or 

  10070. ** the name given after the AS keyword in the [ATTACH] statement for attached

  10071. ** databases.)^

  10072. ** ^The fifth parameter to the preupdate callback is the name of the

  10073. ** table that is being modified.

  10074. **

  10075. ** For an UPDATE or DELETE operation on a [rowid table], the sixth

  10076. ** parameter passed to the preupdate callback is the initial [rowid] of the 

  10077. ** row being modified or deleted. For an INSERT operation on a rowid table,

  10078. ** or any operation on a WITHOUT ROWID table, the value of the sixth 

  10079. ** parameter is undefined. For an INSERT or UPDATE on a rowid table the

  10080. ** seventh parameter is the final rowid value of the row being inserted

  10081. ** or updated. The value of the seventh parameter passed to the callback

  10082. ** function is not defined for operations on WITHOUT ROWID tables, or for

  10083. ** INSERT operations on rowid tables.

  10084. **

  10085. ** The [sqlite3_preupdate_old()], [sqlite3_preupdate_new()],

  10086. ** [sqlite3_preupdate_count()], and [sqlite3_preupdate_depth()] interfaces

  10087. ** provide additional information about a preupdate event. These routines

  10088. ** may only be called from within a preupdate callback.  Invoking any of

  10089. ** these routines from outside of a preupdate callback or with a

  10090. ** [database connection] pointer that is different from the one supplied

  10091. ** to the preupdate callback results in undefined and probably undesirable

  10092. ** behavior.

  10093. **

  10094. ** ^The [sqlite3_preupdate_count(D)] interface returns the number of columns

  10095. ** in the row that is being inserted, updated, or deleted.

  10096. **

  10097. ** ^The [sqlite3_preupdate_old(D,N,P)] interface writes into P a pointer to

  10098. ** a [protected sqlite3_value] that contains the value of the Nth column of

  10099. ** the table row before it is updated.  The N parameter must be between 0

  10100. ** and one less than the number of columns or the behavior will be

  10101. ** undefined. This must only be used within SQLITE_UPDATE and SQLITE_DELETE

  10102. ** preupdate callbacks; if it is used by an SQLITE_INSERT callback then the

  10103. ** behavior is undefined.  The [sqlite3_value] that P points to

  10104. ** will be destroyed when the preupdate callback returns.

  10105. **

  10106. ** ^The [sqlite3_preupdate_new(D,N,P)] interface writes into P a pointer to

  10107. ** a [protected sqlite3_value] that contains the value of the Nth column of

  10108. ** the table row after it is updated.  The N parameter must be between 0

  10109. ** and one less than the number of columns or the behavior will be

  10110. ** undefined. This must only be used within SQLITE_INSERT and SQLITE_UPDATE

  10111. ** preupdate callbacks; if it is used by an SQLITE_DELETE callback then the

  10112. ** behavior is undefined.  The [sqlite3_value] that P points to

  10113. ** will be destroyed when the preupdate callback returns.

  10114. **

  10115. ** ^The [sqlite3_preupdate_depth(D)] interface returns 0 if the preupdate

  10116. ** callback was invoked as a result of a direct insert, update, or delete

  10117. ** operation; or 1 for inserts, updates, or deletes invoked by top-level 

  10118. ** triggers; or 2 for changes resulting from triggers called by top-level

  10119. ** triggers; and so forth.

  10120. **

  10121. ** See also:  [sqlite3_update_hook()]

  10122. */

  10123. #if defined(SQLITE_ENABLE_PREUPDATE_HOOK)

  10124. SQLITE_API void *sqlite3_preupdate_hook(

  10125.   sqlite3 *db,

  10126.   void(*xPreUpdate)(

  10127.     void *pCtx,                   /* Copy of third arg to preupdate_hook() */

  10128.     sqlite3 *db,                  /* Database handle */

  10129.     int op,                       /* SQLITE_UPDATE, DELETE or INSERT */

  10130.     char const *zDb,              /* Database name */

  10131.     char const *zName,            /* Table name */

  10132.     sqlite3_int64 iKey1,          /* Rowid of row about to be deleted/updated */

  10133.     sqlite3_int64 iKey2           /* New rowid value (for a rowid UPDATE) */

  10134.   ),

  10135.   void*

  10136. );

  10137. SQLITE_API int sqlite3_preupdate_old(sqlite3 *, int, sqlite3_value **);

  10138. SQLITE_API int sqlite3_preupdate_count(sqlite3 *);

  10139. SQLITE_API int sqlite3_preupdate_depth(sqlite3 *);

  10140. SQLITE_API int sqlite3_preupdate_new(sqlite3 *, int, sqlite3_value **);

  10141. #endif

  10142. 

  10143. /*

  10144. ** CAPI3REF: Low-level system error code

  10145. **

  10146. ** ^Attempt to return the underlying operating system error code or error

  10147. ** number that caused the most recent I/O error or failure to open a file.

  10148. ** The return value is OS-dependent.  For example, on unix systems, after

  10149. ** [sqlite3_open_v2()] returns [SQLITE_CANTOPEN], this interface could be

  10150. ** called to get back the underlying "errno" that caused the problem, such

  10151. ** as ENOSPC, EAUTH, EISDIR, and so forth.  

  10152. */

  10153. SQLITE_API int sqlite3_system_errno(sqlite3*);

  10154. 

  10155. /*

  10156. ** CAPI3REF: Database Snapshot

  10157. ** KEYWORDS: {snapshot} {sqlite3_snapshot}

  10158. **

  10159. ** An instance of the snapshot object records the state of a [WAL mode]

  10160. ** database for some specific point in history.

  10161. **

  10162. ** In [WAL mode], multiple [database connections] that are open on the

  10163. ** same database file can each be reading a different historical version

  10164. ** of the database file.  When a [database connection] begins a read

  10165. ** transaction, that connection sees an unchanging copy of the database

  10166. ** as it existed for the point in time when the transaction first started.

  10167. ** Subsequent changes to the database from other connections are not seen

  10168. ** by the reader until a new read transaction is started.

  10169. **

  10170. ** The sqlite3_snapshot object records state information about an historical

  10171. ** version of the database file so that it is possible to later open a new read

  10172. ** transaction that sees that historical version of the database rather than

  10173. ** the most recent version.

  10174. */

  10175. typedef struct sqlite3_snapshot {

  10176.   unsigned char hidden[48];

  10177. } sqlite3_snapshot;

  10178. 

  10179. /*

  10180. ** CAPI3REF: Record A Database Snapshot

  10181. ** CONSTRUCTOR: sqlite3_snapshot

  10182. **

  10183. ** ^The [sqlite3_snapshot_get(D,S,P)] interface attempts to make a

  10184. ** new [sqlite3_snapshot] object that records the current state of

  10185. ** schema S in database connection D.  ^On success, the

  10186. ** [sqlite3_snapshot_get(D,S,P)] interface writes a pointer to the newly

  10187. ** created [sqlite3_snapshot] object into *P and returns SQLITE_OK.

  10188. ** If there is not already a read-transaction open on schema S when

  10189. ** this function is called, one is opened automatically. 

  10190. **

  10191. ** The following must be true for this function to succeed. If any of

  10192. ** the following statements are false when sqlite3_snapshot_get() is

  10193. ** called, SQLITE_ERROR is returned. The final value of *P is undefined

  10194. ** in this case. 

  10195. **

  10196. ** <ul>

  10197. **   <li> The database handle must not be in [autocommit mode].

  10198. **

  10199. **   <li> Schema S of [database connection] D must be a [WAL mode] database.

  10200. **

  10201. **   <li> There must not be a write transaction open on schema S of database

  10202. **        connection D.

  10203. **

  10204. **   <li> One or more transactions must have been written to the current wal

  10205. **        file since it was created on disk (by any connection). This means

  10206. **        that a snapshot cannot be taken on a wal mode database with no wal 

  10207. **        file immediately after it is first opened. At least one transaction

  10208. **        must be written to it first.

  10209. ** </ul>

  10210. **

  10211. ** This function may also return SQLITE_NOMEM.  If it is called with the

  10212. ** database handle in autocommit mode but fails for some other reason, 

  10213. ** whether or not a read transaction is opened on schema S is undefined.

  10214. **

  10215. ** The [sqlite3_snapshot] object returned from a successful call to

  10216. ** [sqlite3_snapshot_get()] must be freed using [sqlite3_snapshot_free()]

  10217. ** to avoid a memory leak.

  10218. **

  10219. ** The [sqlite3_snapshot_get()] interface is only available when the

  10220. ** [SQLITE_ENABLE_SNAPSHOT] compile-time option is used.

  10221. */

  10222. SQLITE_API SQLITE_EXPERIMENTAL int sqlite3_snapshot_get(

  10223.   sqlite3 *db,

  10224.   const char *zSchema,

  10225.   sqlite3_snapshot **ppSnapshot

  10226. );

  10227. 

  10228. /*

  10229. ** CAPI3REF: Start a read transaction on an historical snapshot

  10230. ** METHOD: sqlite3_snapshot

  10231. **

  10232. ** ^The [sqlite3_snapshot_open(D,S,P)] interface either starts a new read 

  10233. ** transaction or upgrades an existing one for schema S of 

  10234. ** [database connection] D such that the read transaction refers to 

  10235. ** historical [snapshot] P, rather than the most recent change to the 

  10236. ** database. ^The [sqlite3_snapshot_open()] interface returns SQLITE_OK 

  10237. ** on success or an appropriate [error code] if it fails.

  10238. **

  10239. ** ^In order to succeed, the database connection must not be in 

  10240. ** [autocommit mode] when [sqlite3_snapshot_open(D,S,P)] is called. If there

  10241. ** is already a read transaction open on schema S, then the database handle

  10242. ** must have no active statements (SELECT statements that have been passed

  10243. ** to sqlite3_step() but not sqlite3_reset() or sqlite3_finalize()). 

  10244. ** SQLITE_ERROR is returned if either of these conditions is violated, or

  10245. ** if schema S does not exist, or if the snapshot object is invalid.

  10246. **

  10247. ** ^A call to sqlite3_snapshot_open() will fail to open if the specified

  10248. ** snapshot has been overwritten by a [checkpoint]. In this case 

  10249. ** SQLITE_ERROR_SNAPSHOT is returned.

  10250. **

  10251. ** If there is already a read transaction open when this function is 

  10252. ** invoked, then the same read transaction remains open (on the same

  10253. ** database snapshot) if SQLITE_ERROR, SQLITE_BUSY or SQLITE_ERROR_SNAPSHOT

  10254. ** is returned. If another error code - for example SQLITE_PROTOCOL or an

  10255. ** SQLITE_IOERR error code - is returned, then the final state of the

  10256. ** read transaction is undefined. If SQLITE_OK is returned, then the 

  10257. ** read transaction is now open on database snapshot P.

  10258. **

  10259. ** ^(A call to [sqlite3_snapshot_open(D,S,P)] will fail if the

  10260. ** database connection D does not know that the database file for

  10261. ** schema S is in [WAL mode].  A database connection might not know

  10262. ** that the database file is in [WAL mode] if there has been no prior

  10263. ** I/O on that database connection, or if the database entered [WAL mode] 

  10264. ** after the most recent I/O on the database connection.)^

  10265. ** (Hint: Run "[PRAGMA application_id]" against a newly opened

  10266. ** database connection in order to make it ready to use snapshots.)

  10267. **

  10268. ** The [sqlite3_snapshot_open()] interface is only available when the

  10269. ** [SQLITE_ENABLE_SNAPSHOT] compile-time option is used.

  10270. */

  10271. SQLITE_API SQLITE_EXPERIMENTAL int sqlite3_snapshot_open(

  10272.   sqlite3 *db,

  10273.   const char *zSchema,

  10274.   sqlite3_snapshot *pSnapshot

  10275. );

  10276. 

  10277. /*

  10278. ** CAPI3REF: Destroy a snapshot

  10279. ** DESTRUCTOR: sqlite3_snapshot

  10280. **

  10281. ** ^The [sqlite3_snapshot_free(P)] interface destroys [sqlite3_snapshot] P.

  10282. ** The application must eventually free every [sqlite3_snapshot] object

  10283. ** using this routine to avoid a memory leak.

  10284. **

  10285. ** The [sqlite3_snapshot_free()] interface is only available when the

  10286. ** [SQLITE_ENABLE_SNAPSHOT] compile-time option is used.

  10287. */

  10288. SQLITE_API SQLITE_EXPERIMENTAL void sqlite3_snapshot_free(sqlite3_snapshot*);

  10289. 

  10290. /*

  10291. ** CAPI3REF: Compare the ages of two snapshot handles.

  10292. ** METHOD: sqlite3_snapshot

  10293. **

  10294. ** The sqlite3_snapshot_cmp(P1, P2) interface is used to compare the ages

  10295. ** of two valid snapshot handles. 

  10296. **

  10297. ** If the two snapshot handles are not associated with the same database 

  10298. ** file, the result of the comparison is undefined. 

  10299. **

  10300. ** Additionally, the result of the comparison is only valid if both of the

  10301. ** snapshot handles were obtained by calling sqlite3_snapshot_get() since the

  10302. ** last time the wal file was deleted. The wal file is deleted when the

  10303. ** database is changed back to rollback mode or when the number of database

  10304. ** clients drops to zero. If either snapshot handle was obtained before the 

  10305. ** wal file was last deleted, the value returned by this function 

  10306. ** is undefined.

  10307. **

  10308. ** Otherwise, this API returns a negative value if P1 refers to an older

  10309. ** snapshot than P2, zero if the two handles refer to the same database

  10310. ** snapshot, and a positive value if P1 is a newer snapshot than P2.

  10311. **

  10312. ** This interface is only available if SQLite is compiled with the

  10313. ** [SQLITE_ENABLE_SNAPSHOT] option.

  10314. */

  10315. SQLITE_API SQLITE_EXPERIMENTAL int sqlite3_snapshot_cmp(

  10316.   sqlite3_snapshot *p1,

  10317.   sqlite3_snapshot *p2

  10318. );

  10319. 

  10320. /*

  10321. ** CAPI3REF: Recover snapshots from a wal file

  10322. ** METHOD: sqlite3_snapshot

  10323. **

  10324. ** If a [WAL file] remains on disk after all database connections close

  10325. ** (either through the use of the [SQLITE_FCNTL_PERSIST_WAL] [file control]

  10326. ** or because the last process to have the database opened exited without

  10327. ** calling [sqlite3_close()]) and a new connection is subsequently opened

  10328. ** on that database and [WAL file], the [sqlite3_snapshot_open()] interface

  10329. ** will only be able to open the last transaction added to the WAL file

  10330. ** even though the WAL file contains other valid transactions.

  10331. **

  10332. ** This function attempts to scan the WAL file associated with database zDb

  10333. ** of database handle db and make all valid snapshots available to

  10334. ** sqlite3_snapshot_open(). It is an error if there is already a read

  10335. ** transaction open on the database, or if the database is not a WAL mode

  10336. ** database.

  10337. **

  10338. ** SQLITE_OK is returned if successful, or an SQLite error code otherwise.

  10339. **

  10340. ** This interface is only available if SQLite is compiled with the

  10341. ** [SQLITE_ENABLE_SNAPSHOT] option.

  10342. */

  10343. SQLITE_API SQLITE_EXPERIMENTAL int sqlite3_snapshot_recover(sqlite3 *db, const char *zDb);

  10344. 

  10345. /*

  10346. ** CAPI3REF: Serialize a database

  10347. **

  10348. ** The sqlite3_serialize(D,S,P,F) interface returns a pointer to memory

  10349. ** that is a serialization of the S database on [database connection] D.

  10350. ** If P is not a NULL pointer, then the size of the database in bytes

  10351. ** is written into *P.

  10352. **

  10353. ** For an ordinary on-disk database file, the serialization is just a

  10354. ** copy of the disk file.  For an in-memory database or a "TEMP" database,

  10355. ** the serialization is the same sequence of bytes which would be written

  10356. ** to disk if that database where backed up to disk.

  10357. **

  10358. ** The usual case is that sqlite3_serialize() copies the serialization of

  10359. ** the database into memory obtained from [sqlite3_malloc64()] and returns

  10360. ** a pointer to that memory.  The caller is responsible for freeing the

  10361. ** returned value to avoid a memory leak.  However, if the F argument

  10362. ** contains the SQLITE_SERIALIZE_NOCOPY bit, then no memory allocations

  10363. ** are made, and the sqlite3_serialize() function will return a pointer

  10364. ** to the contiguous memory representation of the database that SQLite

  10365. ** is currently using for that database, or NULL if the no such contiguous

  10366. ** memory representation of the database exists.  A contiguous memory

  10367. ** representation of the database will usually only exist if there has

  10368. ** been a prior call to [sqlite3_deserialize(D,S,...)] with the same

  10369. ** values of D and S.

  10370. ** The size of the database is written into *P even if the 

  10371. ** SQLITE_SERIALIZE_NOCOPY bit is set but no contiguous copy

  10372. ** of the database exists.

  10373. **

  10374. ** A call to sqlite3_serialize(D,S,P,F) might return NULL even if the

  10375. ** SQLITE_SERIALIZE_NOCOPY bit is omitted from argument F if a memory

  10376. ** allocation error occurs.

  10377. **

  10378. ** This interface is only available if SQLite is compiled with the

  10379. ** [SQLITE_ENABLE_DESERIALIZE] option.

  10380. */

  10381. SQLITE_API unsigned char *sqlite3_serialize(

  10382.   sqlite3 *db,           /* The database connection */

  10383.   const char *zSchema,   /* Which DB to serialize. ex: "main", "temp", ... */

  10384.   sqlite3_int64 *piSize, /* Write size of the DB here, if not NULL */

  10385.   unsigned int mFlags    /* Zero or more SQLITE_SERIALIZE_* flags */

  10386. );

  10387. 

  10388. /*

  10389. ** CAPI3REF: Flags for sqlite3_serialize

  10390. **

  10391. ** Zero or more of the following constants can be OR-ed together for

  10392. ** the F argument to [sqlite3_serialize(D,S,P,F)].

  10393. **

  10394. ** SQLITE_SERIALIZE_NOCOPY means that [sqlite3_serialize()] will return

  10395. ** a pointer to contiguous in-memory database that it is currently using,

  10396. ** without making a copy of the database.  If SQLite is not currently using

  10397. ** a contiguous in-memory database, then this option causes

  10398. ** [sqlite3_serialize()] to return a NULL pointer.  SQLite will only be

  10399. ** using a contiguous in-memory database if it has been initialized by a

  10400. ** prior call to [sqlite3_deserialize()].

  10401. */

  10402. #define SQLITE_SERIALIZE_NOCOPY 0x001   /* Do no memory allocations */

  10403. 

  10404. /*

  10405. ** CAPI3REF: Deserialize a database

  10406. **

  10407. ** The sqlite3_deserialize(D,S,P,N,M,F) interface causes the 

  10408. ** [database connection] D to disconnect from database S and then

  10409. ** reopen S as an in-memory database based on the serialization contained

  10410. ** in P.  The serialized database P is N bytes in size.  M is the size of

  10411. ** the buffer P, which might be larger than N.  If M is larger than N, and

  10412. ** the SQLITE_DESERIALIZE_READONLY bit is not set in F, then SQLite is

  10413. ** permitted to add content to the in-memory database as long as the total

  10414. ** size does not exceed M bytes.

  10415. **

  10416. ** If the SQLITE_DESERIALIZE_FREEONCLOSE bit is set in F, then SQLite will

  10417. ** invoke sqlite3_free() on the serialization buffer when the database

  10418. ** connection closes.  If the SQLITE_DESERIALIZE_RESIZEABLE bit is set, then

  10419. ** SQLite will try to increase the buffer size using sqlite3_realloc64()

  10420. ** if writes on the database cause it to grow larger than M bytes.

  10421. **

  10422. ** The sqlite3_deserialize() interface will fail with SQLITE_BUSY if the

  10423. ** database is currently in a read transaction or is involved in a backup

  10424. ** operation.

  10425. **

  10426. ** If sqlite3_deserialize(D,S,P,N,M,F) fails for any reason and if the 

  10427. ** SQLITE_DESERIALIZE_FREEONCLOSE bit is set in argument F, then

  10428. ** [sqlite3_free()] is invoked on argument P prior to returning.

  10429. **

  10430. ** This interface is only available if SQLite is compiled with the

  10431. ** [SQLITE_ENABLE_DESERIALIZE] option.

  10432. */

  10433. SQLITE_API int sqlite3_deserialize(

  10434.   sqlite3 *db,            /* The database connection */

  10435.   const char *zSchema,    /* Which DB to reopen with the deserialization */

  10436.   unsigned char *pData,   /* The serialized database content */

  10437.   sqlite3_int64 szDb,     /* Number bytes in the deserialization */

  10438.   sqlite3_int64 szBuf,    /* Total size of buffer pData[] */

  10439.   unsigned mFlags         /* Zero or more SQLITE_DESERIALIZE_* flags */

  10440. );

  10441. 

  10442. /*

  10443. ** CAPI3REF: Flags for sqlite3_deserialize()

  10444. **

  10445. ** The following are allowed values for 6th argument (the F argument) to

  10446. ** the [sqlite3_deserialize(D,S,P,N,M,F)] interface.

  10447. **

  10448. ** The SQLITE_DESERIALIZE_FREEONCLOSE means that the database serialization

  10449. ** in the P argument is held in memory obtained from [sqlite3_malloc64()]

  10450. ** and that SQLite should take ownership of this memory and automatically

  10451. ** free it when it has finished using it.  Without this flag, the caller

  10452. ** is responsible for freeing any dynamically allocated memory.

  10453. **

  10454. ** The SQLITE_DESERIALIZE_RESIZEABLE flag means that SQLite is allowed to

  10455. ** grow the size of the database using calls to [sqlite3_realloc64()].  This

  10456. ** flag should only be used if SQLITE_DESERIALIZE_FREEONCLOSE is also used.

  10457. ** Without this flag, the deserialized database cannot increase in size beyond

  10458. ** the number of bytes specified by the M parameter.

  10459. **

  10460. ** The SQLITE_DESERIALIZE_READONLY flag means that the deserialized database

  10461. ** should be treated as read-only.

  10462. */

  10463. #define SQLITE_DESERIALIZE_FREEONCLOSE 1 /* Call sqlite3_free() on close */

  10464. #define SQLITE_DESERIALIZE_RESIZEABLE  2 /* Resize using sqlite3_realloc64() */

  10465. #define SQLITE_DESERIALIZE_READONLY    4 /* Database is read-only */

  10466. 

  10467. /*

  10468. ** Undo the hack that converts floating point types to integer for

  10469. ** builds on processors without floating point support.

  10470. */

  10471. #ifdef SQLITE_OMIT_FLOATING_POINT

  10472. # undef double

  10473. #endif

  10474. 

  10475. #if 0

  10476. }  /* End of the 'extern "C"' block */

  10477. #endif

  10478. #endif /* SQLITE3_H */

  10479. 

  10480. /******** Begin file sqlite3rtree.h *********/

  10481. /*

  10482. ** 2010 August 30

  10483. **

  10484. ** The author disclaims copyright to this source code.  In place of

  10485. ** a legal notice, here is a blessing:

  10486. **

  10487. **    May you do good and not evil.

  10488. **    May you find forgiveness for yourself and forgive others.

  10489. **    May you share freely, never taking more than you give.

  10490. **

  10491. *************************************************************************

  10492. */

  10493. 

  10494. #ifndef _SQLITE3RTREE_H_

  10495. #define _SQLITE3RTREE_H_

  10496. 

  10497. 

  10498. #if 0

  10499. extern "C" {

  10500. #endif

  10501. 

  10502. typedef struct sqlite3_rtree_geometry sqlite3_rtree_geometry;

  10503. typedef struct sqlite3_rtree_query_info sqlite3_rtree_query_info;

  10504. 

  10505. /* The double-precision datatype used by RTree depends on the

  10506. ** SQLITE_RTREE_INT_ONLY compile-time option.

  10507. */

  10508. #ifdef SQLITE_RTREE_INT_ONLY

  10509.   typedef sqlite3_int64 sqlite3_rtree_dbl;

  10510. #else

  10511.   typedef double sqlite3_rtree_dbl;

  10512. #endif

  10513. 

  10514. /*

  10515. ** Register a geometry callback named zGeom that can be used as part of an

  10516. ** R-Tree geometry query as follows:

  10517. **

  10518. **   SELECT ... FROM <rtree> WHERE <rtree col> MATCH $zGeom(... params ...)

  10519. */

  10520. SQLITE_API int sqlite3_rtree_geometry_callback(

  10521.   sqlite3 *db,

  10522.   const char *zGeom,

  10523.   int (*xGeom)(sqlite3_rtree_geometry*, int, sqlite3_rtree_dbl*,int*),

  10524.   void *pContext

  10525. );

  10526. 

  10527. 

  10528. /*

  10529. ** A pointer to a structure of the following type is passed as the first

  10530. ** argument to callbacks registered using rtree_geometry_callback().

  10531. */

  10532. struct sqlite3_rtree_geometry {

  10533.   void *pContext;                 /* Copy of pContext passed to s_r_g_c() */

  10534.   int nParam;                     /* Size of array aParam[] */

  10535.   sqlite3_rtree_dbl *aParam;      /* Parameters passed to SQL geom function */

  10536.   void *pUser;                    /* Callback implementation user data */

  10537.   void (*xDelUser)(void *);       /* Called by SQLite to clean up pUser */

  10538. };

  10539. 

  10540. /*

  10541. ** Register a 2nd-generation geometry callback named zScore that can be 

  10542. ** used as part of an R-Tree geometry query as follows:

  10543. **

  10544. **   SELECT ... FROM <rtree> WHERE <rtree col> MATCH $zQueryFunc(... params ...)

  10545. */

  10546. SQLITE_API int sqlite3_rtree_query_callback(

  10547.   sqlite3 *db,

  10548.   const char *zQueryFunc,

  10549.   int (*xQueryFunc)(sqlite3_rtree_query_info*),

  10550.   void *pContext,

  10551.   void (*xDestructor)(void*)

  10552. );

  10553. 

  10554. 

  10555. /*

  10556. ** A pointer to a structure of the following type is passed as the 

  10557. ** argument to scored geometry callback registered using

  10558. ** sqlite3_rtree_query_callback().

  10559. **

  10560. ** Note that the first 5 fields of this structure are identical to

  10561. ** sqlite3_rtree_geometry.  This structure is a subclass of

  10562. ** sqlite3_rtree_geometry.

  10563. */

  10564. struct sqlite3_rtree_query_info {

  10565.   void *pContext;                   /* pContext from when function registered */

  10566.   int nParam;                       /* Number of function parameters */

  10567.   sqlite3_rtree_dbl *aParam;        /* value of function parameters */

  10568.   void *pUser;                      /* callback can use this, if desired */

  10569.   void (*xDelUser)(void*);          /* function to free pUser */

  10570.   sqlite3_rtree_dbl *aCoord;        /* Coordinates of node or entry to check */

  10571.   unsigned int *anQueue;            /* Number of pending entries in the queue */

  10572.   int nCoord;                       /* Number of coordinates */

  10573.   int iLevel;                       /* Level of current node or entry */

  10574.   int mxLevel;                      /* The largest iLevel value in the tree */

  10575.   sqlite3_int64 iRowid;             /* Rowid for current entry */

  10576.   sqlite3_rtree_dbl rParentScore;   /* Score of parent node */

  10577.   int eParentWithin;                /* Visibility of parent node */

  10578.   int eWithin;                      /* OUT: Visibility */

  10579.   sqlite3_rtree_dbl rScore;         /* OUT: Write the score here */

  10580.   /* The following fields are only available in 3.8.11 and later */

  10581.   sqlite3_value **apSqlParam;       /* Original SQL values of parameters */

  10582. };

  10583. 

  10584. /*

  10585. ** Allowed values for sqlite3_rtree_query.eWithin and .eParentWithin.

  10586. */

  10587. #define NOT_WITHIN       0   /* Object completely outside of query region */

  10588. #define PARTLY_WITHIN    1   /* Object partially overlaps query region */

  10589. #define FULLY_WITHIN     2   /* Object fully contained within query region */

  10590. 

  10591. 

  10592. #if 0

  10593. }  /* end of the 'extern "C"' block */

  10594. #endif

  10595. 

  10596. #endif  /* ifndef _SQLITE3RTREE_H_ */

  10597. 

  10598. /******** End of sqlite3rtree.h *********/

  10599. /******** Begin file sqlite3session.h *********/

  10600. 

  10601. #if !defined(__SQLITESESSION_H_) && defined(SQLITE_ENABLE_SESSION)

  10602. #define __SQLITESESSION_H_ 1

  10603. 

  10604. /*

  10605. ** Make sure we can call this stuff from C++.

  10606. */

  10607. #if 0

  10608. extern "C" {

  10609. #endif

  10610. 

  10611. 

  10612. /*

  10613. ** CAPI3REF: Session Object Handle

  10614. **

  10615. ** An instance of this object is a [session] that can be used to

  10616. ** record changes to a database.

  10617. */

  10618. typedef struct sqlite3_session sqlite3_session;

  10619. 

  10620. /*

  10621. ** CAPI3REF: Changeset Iterator Handle

  10622. **

  10623. ** An instance of this object acts as a cursor for iterating

  10624. ** over the elements of a [changeset] or [patchset].

  10625. */

  10626. typedef struct sqlite3_changeset_iter sqlite3_changeset_iter;

  10627. 

  10628. /*

  10629. ** CAPI3REF: Create A New Session Object

  10630. ** CONSTRUCTOR: sqlite3_session

  10631. **

  10632. ** Create a new session object attached to database handle db. If successful,

  10633. ** a pointer to the new object is written to *ppSession and SQLITE_OK is

  10634. ** returned. If an error occurs, *ppSession is set to NULL and an SQLite

  10635. ** error code (e.g. SQLITE_NOMEM) is returned.

  10636. **

  10637. ** It is possible to create multiple session objects attached to a single

  10638. ** database handle.

  10639. **

  10640. ** Session objects created using this function should be deleted using the

  10641. ** [sqlite3session_delete()] function before the database handle that they

  10642. ** are attached to is itself closed. If the database handle is closed before

  10643. ** the session object is deleted, then the results of calling any session

  10644. ** module function, including [sqlite3session_delete()] on the session object

  10645. ** are undefined.

  10646. **

  10647. ** Because the session module uses the [sqlite3_preupdate_hook()] API, it

  10648. ** is not possible for an application to register a pre-update hook on a

  10649. ** database handle that has one or more session objects attached. Nor is

  10650. ** it possible to create a session object attached to a database handle for

  10651. ** which a pre-update hook is already defined. The results of attempting 

  10652. ** either of these things are undefined.

  10653. **

  10654. ** The session object will be used to create changesets for tables in

  10655. ** database zDb, where zDb is either "main", or "temp", or the name of an

  10656. ** attached database. It is not an error if database zDb is not attached

  10657. ** to the database when the session object is created.

  10658. */

  10659. SQLITE_API int sqlite3session_create(

  10660.   sqlite3 *db,                    /* Database handle */

  10661.   const char *zDb,                /* Name of db (e.g. "main") */

  10662.   sqlite3_session **ppSession     /* OUT: New session object */

  10663. );

  10664. 

  10665. /*

  10666. ** CAPI3REF: Delete A Session Object

  10667. ** DESTRUCTOR: sqlite3_session

  10668. **

  10669. ** Delete a session object previously allocated using 

  10670. ** [sqlite3session_create()]. Once a session object has been deleted, the

  10671. ** results of attempting to use pSession with any other session module

  10672. ** function are undefined.

  10673. **

  10674. ** Session objects must be deleted before the database handle to which they

  10675. ** are attached is closed. Refer to the documentation for 

  10676. ** [sqlite3session_create()] for details.

  10677. */

  10678. SQLITE_API void sqlite3session_delete(sqlite3_session *pSession);

  10679. 

  10680. 

  10681. /*

  10682. ** CAPI3REF: Enable Or Disable A Session Object

  10683. ** METHOD: sqlite3_session

  10684. **

  10685. ** Enable or disable the recording of changes by a session object. When

  10686. ** enabled, a session object records changes made to the database. When

  10687. ** disabled - it does not. A newly created session object is enabled.

  10688. ** Refer to the documentation for [sqlite3session_changeset()] for further

  10689. ** details regarding how enabling and disabling a session object affects

  10690. ** the eventual changesets.

  10691. **

  10692. ** Passing zero to this function disables the session. Passing a value

  10693. ** greater than zero enables it. Passing a value less than zero is a 

  10694. ** no-op, and may be used to query the current state of the session.

  10695. **

  10696. ** The return value indicates the final state of the session object: 0 if 

  10697. ** the session is disabled, or 1 if it is enabled.

  10698. */

  10699. SQLITE_API int sqlite3session_enable(sqlite3_session *pSession, int bEnable);

  10700. 

  10701. /*

  10702. ** CAPI3REF: Set Or Clear the Indirect Change Flag

  10703. ** METHOD: sqlite3_session

  10704. **

  10705. ** Each change recorded by a session object is marked as either direct or

  10706. ** indirect. A change is marked as indirect if either:

  10707. **

  10708. ** <ul>

  10709. **   <li> The session object "indirect" flag is set when the change is

  10710. **        made, or

  10711. **   <li> The change is made by an SQL trigger or foreign key action 

  10712. **        instead of directly as a result of a users SQL statement.

  10713. ** </ul>

  10714. **

  10715. ** If a single row is affected by more than one operation within a session,

  10716. ** then the change is considered indirect if all operations meet the criteria

  10717. ** for an indirect change above, or direct otherwise.

  10718. **

  10719. ** This function is used to set, clear or query the session object indirect

  10720. ** flag.  If the second argument passed to this function is zero, then the

  10721. ** indirect flag is cleared. If it is greater than zero, the indirect flag

  10722. ** is set. Passing a value less than zero does not modify the current value

  10723. ** of the indirect flag, and may be used to query the current state of the 

  10724. ** indirect flag for the specified session object.

  10725. **

  10726. ** The return value indicates the final state of the indirect flag: 0 if 

  10727. ** it is clear, or 1 if it is set.

  10728. */

  10729. SQLITE_API int sqlite3session_indirect(sqlite3_session *pSession, int bIndirect);

  10730. 

  10731. /*

  10732. ** CAPI3REF: Attach A Table To A Session Object

  10733. ** METHOD: sqlite3_session

  10734. **

  10735. ** If argument zTab is not NULL, then it is the name of a table to attach

  10736. ** to the session object passed as the first argument. All subsequent changes 

  10737. ** made to the table while the session object is enabled will be recorded. See 

  10738. ** documentation for [sqlite3session_changeset()] for further details.

  10739. **

  10740. ** Or, if argument zTab is NULL, then changes are recorded for all tables

  10741. ** in the database. If additional tables are added to the database (by 

  10742. ** executing "CREATE TABLE" statements) after this call is made, changes for 

  10743. ** the new tables are also recorded.

  10744. **

  10745. ** Changes can only be recorded for tables that have a PRIMARY KEY explicitly

  10746. ** defined as part of their CREATE TABLE statement. It does not matter if the 

  10747. ** PRIMARY KEY is an "INTEGER PRIMARY KEY" (rowid alias) or not. The PRIMARY

  10748. ** KEY may consist of a single column, or may be a composite key.

  10749. ** 

  10750. ** It is not an error if the named table does not exist in the database. Nor

  10751. ** is it an error if the named table does not have a PRIMARY KEY. However,

  10752. ** no changes will be recorded in either of these scenarios.

  10753. **

  10754. ** Changes are not recorded for individual rows that have NULL values stored

  10755. ** in one or more of their PRIMARY KEY columns.

  10756. **

  10757. ** SQLITE_OK is returned if the call completes without error. Or, if an error 

  10758. ** occurs, an SQLite error code (e.g. SQLITE_NOMEM) is returned.

  10759. **

  10760. ** <h3>Special sqlite_stat1 Handling</h3>

  10761. **

  10762. ** As of SQLite version 3.22.0, the "sqlite_stat1" table is an exception to 

  10763. ** some of the rules above. In SQLite, the schema of sqlite_stat1 is:

  10764. **  <pre>

  10765. **  &nbsp;     CREATE TABLE sqlite_stat1(tbl,idx,stat)  

  10766. **  </pre>

  10767. **

  10768. ** Even though sqlite_stat1 does not have a PRIMARY KEY, changes are 

  10769. ** recorded for it as if the PRIMARY KEY is (tbl,idx). Additionally, changes 

  10770. ** are recorded for rows for which (idx IS NULL) is true. However, for such

  10771. ** rows a zero-length blob (SQL value X'') is stored in the changeset or

  10772. ** patchset instead of a NULL value. This allows such changesets to be

  10773. ** manipulated by legacy implementations of sqlite3changeset_invert(),

  10774. ** concat() and similar.

  10775. **

  10776. ** The sqlite3changeset_apply() function automatically converts the 

  10777. ** zero-length blob back to a NULL value when updating the sqlite_stat1

  10778. ** table. However, if the application calls sqlite3changeset_new(),

  10779. ** sqlite3changeset_old() or sqlite3changeset_conflict on a changeset 

  10780. ** iterator directly (including on a changeset iterator passed to a

  10781. ** conflict-handler callback) then the X'' value is returned. The application

  10782. ** must translate X'' to NULL itself if required.

  10783. **

  10784. ** Legacy (older than 3.22.0) versions of the sessions module cannot capture

  10785. ** changes made to the sqlite_stat1 table. Legacy versions of the

  10786. ** sqlite3changeset_apply() function silently ignore any modifications to the

  10787. ** sqlite_stat1 table that are part of a changeset or patchset.

  10788. */

  10789. SQLITE_API int sqlite3session_attach(

  10790.   sqlite3_session *pSession,      /* Session object */

  10791.   const char *zTab                /* Table name */

  10792. );

  10793. 

  10794. /*

  10795. ** CAPI3REF: Set a table filter on a Session Object.

  10796. ** METHOD: sqlite3_session

  10797. **

  10798. ** The second argument (xFilter) is the "filter callback". For changes to rows 

  10799. ** in tables that are not attached to the Session object, the filter is called

  10800. ** to determine whether changes to the table's rows should be tracked or not. 

  10801. ** If xFilter returns 0, changes is not tracked. Note that once a table is 

  10802. ** attached, xFilter will not be called again.

  10803. */

  10804. SQLITE_API void sqlite3session_table_filter(

  10805.   sqlite3_session *pSession,      /* Session object */

  10806.   int(*xFilter)(

  10807.     void *pCtx,                   /* Copy of third arg to _filter_table() */

  10808.     const char *zTab              /* Table name */

  10809.   ),

  10810.   void *pCtx                      /* First argument passed to xFilter */

  10811. );

  10812. 

  10813. /*

  10814. ** CAPI3REF: Generate A Changeset From A Session Object

  10815. ** METHOD: sqlite3_session

  10816. **

  10817. ** Obtain a changeset containing changes to the tables attached to the 

  10818. ** session object passed as the first argument. If successful, 

  10819. ** set *ppChangeset to point to a buffer containing the changeset 

  10820. ** and *pnChangeset to the size of the changeset in bytes before returning

  10821. ** SQLITE_OK. If an error occurs, set both *ppChangeset and *pnChangeset to

  10822. ** zero and return an SQLite error code.

  10823. **

  10824. ** A changeset consists of zero or more INSERT, UPDATE and/or DELETE changes,

  10825. ** each representing a change to a single row of an attached table. An INSERT

  10826. ** change contains the values of each field of a new database row. A DELETE

  10827. ** contains the original values of each field of a deleted database row. An

  10828. ** UPDATE change contains the original values of each field of an updated

  10829. ** database row along with the updated values for each updated non-primary-key

  10830. ** column. It is not possible for an UPDATE change to represent a change that

  10831. ** modifies the values of primary key columns. If such a change is made, it

  10832. ** is represented in a changeset as a DELETE followed by an INSERT.

  10833. **

  10834. ** Changes are not recorded for rows that have NULL values stored in one or 

  10835. ** more of their PRIMARY KEY columns. If such a row is inserted or deleted,

  10836. ** no corresponding change is present in the changesets returned by this

  10837. ** function. If an existing row with one or more NULL values stored in

  10838. ** PRIMARY KEY columns is updated so that all PRIMARY KEY columns are non-NULL,

  10839. ** only an INSERT is appears in the changeset. Similarly, if an existing row

  10840. ** with non-NULL PRIMARY KEY values is updated so that one or more of its

  10841. ** PRIMARY KEY columns are set to NULL, the resulting changeset contains a

  10842. ** DELETE change only.

  10843. **

  10844. ** The contents of a changeset may be traversed using an iterator created

  10845. ** using the [sqlite3changeset_start()] API. A changeset may be applied to

  10846. ** a database with a compatible schema using the [sqlite3changeset_apply()]

  10847. ** API.

  10848. **

  10849. ** Within a changeset generated by this function, all changes related to a

  10850. ** single table are grouped together. In other words, when iterating through

  10851. ** a changeset or when applying a changeset to a database, all changes related

  10852. ** to a single table are processed before moving on to the next table. Tables

  10853. ** are sorted in the same order in which they were attached (or auto-attached)

  10854. ** to the sqlite3_session object. The order in which the changes related to

  10855. ** a single table are stored is undefined.

  10856. **

  10857. ** Following a successful call to this function, it is the responsibility of

  10858. ** the caller to eventually free the buffer that *ppChangeset points to using

  10859. ** [sqlite3_free()].

  10860. **

  10861. ** <h3>Changeset Generation</h3>

  10862. **

  10863. ** Once a table has been attached to a session object, the session object

  10864. ** records the primary key values of all new rows inserted into the table.

  10865. ** It also records the original primary key and other column values of any

  10866. ** deleted or updated rows. For each unique primary key value, data is only

  10867. ** recorded once - the first time a row with said primary key is inserted,

  10868. ** updated or deleted in the lifetime of the session.

  10869. **

  10870. ** There is one exception to the previous paragraph: when a row is inserted,

  10871. ** updated or deleted, if one or more of its primary key columns contain a

  10872. ** NULL value, no record of the change is made.

  10873. **

  10874. ** The session object therefore accumulates two types of records - those

  10875. ** that consist of primary key values only (created when the user inserts

  10876. ** a new record) and those that consist of the primary key values and the

  10877. ** original values of other table columns (created when the users deletes

  10878. ** or updates a record).

  10879. **

  10880. ** When this function is called, the requested changeset is created using

  10881. ** both the accumulated records and the current contents of the database

  10882. ** file. Specifically:

  10883. **

  10884. ** <ul>

  10885. **   <li> For each record generated by an insert, the database is queried

  10886. **        for a row with a matching primary key. If one is found, an INSERT

  10887. **        change is added to the changeset. If no such row is found, no change 

  10888. **        is added to the changeset.

  10889. **

  10890. **   <li> For each record generated by an update or delete, the database is 

  10891. **        queried for a row with a matching primary key. If such a row is

  10892. **        found and one or more of the non-primary key fields have been

  10893. **        modified from their original values, an UPDATE change is added to 

  10894. **        the changeset. Or, if no such row is found in the table, a DELETE 

  10895. **        change is added to the changeset. If there is a row with a matching

  10896. **        primary key in the database, but all fields contain their original

  10897. **        values, no change is added to the changeset.

  10898. ** </ul>

  10899. **

  10900. ** This means, amongst other things, that if a row is inserted and then later

  10901. ** deleted while a session object is active, neither the insert nor the delete

  10902. ** will be present in the changeset. Or if a row is deleted and then later a 

  10903. ** row with the same primary key values inserted while a session object is

  10904. ** active, the resulting changeset will contain an UPDATE change instead of

  10905. ** a DELETE and an INSERT.

  10906. **

  10907. ** When a session object is disabled (see the [sqlite3session_enable()] API),

  10908. ** it does not accumulate records when rows are inserted, updated or deleted.

  10909. ** This may appear to have some counter-intuitive effects if a single row

  10910. ** is written to more than once during a session. For example, if a row

  10911. ** is inserted while a session object is enabled, then later deleted while 

  10912. ** the same session object is disabled, no INSERT record will appear in the

  10913. ** changeset, even though the delete took place while the session was disabled.

  10914. ** Or, if one field of a row is updated while a session is disabled, and 

  10915. ** another field of the same row is updated while the session is enabled, the

  10916. ** resulting changeset will contain an UPDATE change that updates both fields.

  10917. */

  10918. SQLITE_API int sqlite3session_changeset(

  10919.   sqlite3_session *pSession,      /* Session object */

  10920.   int *pnChangeset,               /* OUT: Size of buffer at *ppChangeset */

  10921.   void **ppChangeset              /* OUT: Buffer containing changeset */

  10922. );

  10923. 

  10924. /*

  10925. ** CAPI3REF: Load The Difference Between Tables Into A Session

  10926. ** METHOD: sqlite3_session

  10927. **

  10928. ** If it is not already attached to the session object passed as the first

  10929. ** argument, this function attaches table zTbl in the same manner as the

  10930. ** [sqlite3session_attach()] function. If zTbl does not exist, or if it

  10931. ** does not have a primary key, this function is a no-op (but does not return

  10932. ** an error).

  10933. **

  10934. ** Argument zFromDb must be the name of a database ("main", "temp" etc.)

  10935. ** attached to the same database handle as the session object that contains 

  10936. ** a table compatible with the table attached to the session by this function.

  10937. ** A table is considered compatible if it:

  10938. **

  10939. ** <ul>

  10940. **   <li> Has the same name,

  10941. **   <li> Has the same set of columns declared in the same order, and

  10942. **   <li> Has the same PRIMARY KEY definition.

  10943. ** </ul>

  10944. **

  10945. ** If the tables are not compatible, SQLITE_SCHEMA is returned. If the tables

  10946. ** are compatible but do not have any PRIMARY KEY columns, it is not an error

  10947. ** but no changes are added to the session object. As with other session

  10948. ** APIs, tables without PRIMARY KEYs are simply ignored.

  10949. **

  10950. ** This function adds a set of changes to the session object that could be

  10951. ** used to update the table in database zFrom (call this the "from-table") 

  10952. ** so that its content is the same as the table attached to the session 

  10953. ** object (call this the "to-table"). Specifically:

  10954. **

  10955. ** <ul>

  10956. **   <li> For each row (primary key) that exists in the to-table but not in 

  10957. **     the from-table, an INSERT record is added to the session object.

  10958. **

  10959. **   <li> For each row (primary key) that exists in the to-table but not in 

  10960. **     the from-table, a DELETE record is added to the session object.

  10961. **

  10962. **   <li> For each row (primary key) that exists in both tables, but features 

  10963. **     different non-PK values in each, an UPDATE record is added to the

  10964. **     session.  

  10965. ** </ul>

  10966. **

  10967. ** To clarify, if this function is called and then a changeset constructed

  10968. ** using [sqlite3session_changeset()], then after applying that changeset to 

  10969. ** database zFrom the contents of the two compatible tables would be 

  10970. ** identical.

  10971. **

  10972. ** It an error if database zFrom does not exist or does not contain the

  10973. ** required compatible table.

  10974. **

  10975. ** If the operation successful, SQLITE_OK is returned. Otherwise, an SQLite

  10976. ** error code. In this case, if argument pzErrMsg is not NULL, *pzErrMsg

  10977. ** may be set to point to a buffer containing an English language error 

  10978. ** message. It is the responsibility of the caller to free this buffer using

  10979. ** sqlite3_free().

  10980. */

  10981. SQLITE_API int sqlite3session_diff(

  10982.   sqlite3_session *pSession,

  10983.   const char *zFromDb,

  10984.   const char *zTbl,

  10985.   char **pzErrMsg

  10986. );

  10987. 

  10988. 

  10989. /*

  10990. ** CAPI3REF: Generate A Patchset From A Session Object

  10991. ** METHOD: sqlite3_session

  10992. **

  10993. ** The differences between a patchset and a changeset are that:

  10994. **

  10995. ** <ul>

  10996. **   <li> DELETE records consist of the primary key fields only. The 

  10997. **        original values of other fields are omitted.

  10998. **   <li> The original values of any modified fields are omitted from 

  10999. **        UPDATE records.

  11000. ** </ul>

  11001. **

  11002. ** A patchset blob may be used with up to date versions of all 

  11003. ** sqlite3changeset_xxx API functions except for sqlite3changeset_invert(), 

  11004. ** which returns SQLITE_CORRUPT if it is passed a patchset. Similarly,

  11005. ** attempting to use a patchset blob with old versions of the

  11006. ** sqlite3changeset_xxx APIs also provokes an SQLITE_CORRUPT error. 

  11007. **

  11008. ** Because the non-primary key "old.*" fields are omitted, no 

  11009. ** SQLITE_CHANGESET_DATA conflicts can be detected or reported if a patchset

  11010. ** is passed to the sqlite3changeset_apply() API. Other conflict types work

  11011. ** in the same way as for changesets.

  11012. **

  11013. ** Changes within a patchset are ordered in the same way as for changesets

  11014. ** generated by the sqlite3session_changeset() function (i.e. all changes for

  11015. ** a single table are grouped together, tables appear in the order in which

  11016. ** they were attached to the session object).

  11017. */

  11018. SQLITE_API int sqlite3session_patchset(

  11019.   sqlite3_session *pSession,      /* Session object */

  11020.   int *pnPatchset,                /* OUT: Size of buffer at *ppPatchset */

  11021.   void **ppPatchset               /* OUT: Buffer containing patchset */

  11022. );

  11023. 

  11024. /*

  11025. ** CAPI3REF: Test if a changeset has recorded any changes.

  11026. **

  11027. ** Return non-zero if no changes to attached tables have been recorded by 

  11028. ** the session object passed as the first argument. Otherwise, if one or 

  11029. ** more changes have been recorded, return zero.

  11030. **

  11031. ** Even if this function returns zero, it is possible that calling

  11032. ** [sqlite3session_changeset()] on the session handle may still return a

  11033. ** changeset that contains no changes. This can happen when a row in 

  11034. ** an attached table is modified and then later on the original values 

  11035. ** are restored. However, if this function returns non-zero, then it is

  11036. ** guaranteed that a call to sqlite3session_changeset() will return a 

  11037. ** changeset containing zero changes.

  11038. */

  11039. SQLITE_API int sqlite3session_isempty(sqlite3_session *pSession);

  11040. 

  11041. /*

  11042. ** CAPI3REF: Create An Iterator To Traverse A Changeset 

  11043. ** CONSTRUCTOR: sqlite3_changeset_iter

  11044. **

  11045. ** Create an iterator used to iterate through the contents of a changeset.

  11046. ** If successful, *pp is set to point to the iterator handle and SQLITE_OK

  11047. ** is returned. Otherwise, if an error occurs, *pp is set to zero and an

  11048. ** SQLite error code is returned.

  11049. **

  11050. ** The following functions can be used to advance and query a changeset 

  11051. ** iterator created by this function:

  11052. **

  11053. ** <ul>

  11054. **   <li> [sqlite3changeset_next()]

  11055. **   <li> [sqlite3changeset_op()]

  11056. **   <li> [sqlite3changeset_new()]

  11057. **   <li> [sqlite3changeset_old()]

  11058. ** </ul>

  11059. **

  11060. ** It is the responsibility of the caller to eventually destroy the iterator

  11061. ** by passing it to [sqlite3changeset_finalize()]. The buffer containing the

  11062. ** changeset (pChangeset) must remain valid until after the iterator is

  11063. ** destroyed.

  11064. **

  11065. ** Assuming the changeset blob was created by one of the

  11066. ** [sqlite3session_changeset()], [sqlite3changeset_concat()] or

  11067. ** [sqlite3changeset_invert()] functions, all changes within the changeset 

  11068. ** that apply to a single table are grouped together. This means that when 

  11069. ** an application iterates through a changeset using an iterator created by 

  11070. ** this function, all changes that relate to a single table are visited 

  11071. ** consecutively. There is no chance that the iterator will visit a change 

  11072. ** the applies to table X, then one for table Y, and then later on visit 

  11073. ** another change for table X.

  11074. **

  11075. ** The behavior of sqlite3changeset_start_v2() and its streaming equivalent

  11076. ** may be modified by passing a combination of

  11077. ** [SQLITE_CHANGESETSTART_INVERT | supported flags] as the 4th parameter.

  11078. **

  11079. ** Note that the sqlite3changeset_start_v2() API is still <b>experimental</b>

  11080. ** and therefore subject to change.

  11081. */

  11082. SQLITE_API int sqlite3changeset_start(

  11083.   sqlite3_changeset_iter **pp,    /* OUT: New changeset iterator handle */

  11084.   int nChangeset,                 /* Size of changeset blob in bytes */

  11085.   void *pChangeset                /* Pointer to blob containing changeset */

  11086. );

  11087. SQLITE_API int sqlite3changeset_start_v2(

  11088.   sqlite3_changeset_iter **pp,    /* OUT: New changeset iterator handle */

  11089.   int nChangeset,                 /* Size of changeset blob in bytes */

  11090.   void *pChangeset,               /* Pointer to blob containing changeset */

  11091.   int flags                       /* SESSION_CHANGESETSTART_* flags */

  11092. );

  11093. 

  11094. /*

  11095. ** CAPI3REF: Flags for sqlite3changeset_start_v2

  11096. **

  11097. ** The following flags may passed via the 4th parameter to

  11098. ** [sqlite3changeset_start_v2] and [sqlite3changeset_start_v2_strm]:

  11099. **

  11100. ** <dt>SQLITE_CHANGESETAPPLY_INVERT <dd>

  11101. **   Invert the changeset while iterating through it. This is equivalent to

  11102. **   inverting a changeset using sqlite3changeset_invert() before applying it.

  11103. **   It is an error to specify this flag with a patchset.

  11104. */

  11105. #define SQLITE_CHANGESETSTART_INVERT        0x0002

  11106. 

  11107. 

  11108. /*

  11109. ** CAPI3REF: Advance A Changeset Iterator

  11110. ** METHOD: sqlite3_changeset_iter

  11111. **

  11112. ** This function may only be used with iterators created by function

  11113. ** [sqlite3changeset_start()]. If it is called on an iterator passed to

  11114. ** a conflict-handler callback by [sqlite3changeset_apply()], SQLITE_MISUSE

  11115. ** is returned and the call has no effect.

  11116. **

  11117. ** Immediately after an iterator is created by sqlite3changeset_start(), it

  11118. ** does not point to any change in the changeset. Assuming the changeset

  11119. ** is not empty, the first call to this function advances the iterator to

  11120. ** point to the first change in the changeset. Each subsequent call advances

  11121. ** the iterator to point to the next change in the changeset (if any). If

  11122. ** no error occurs and the iterator points to a valid change after a call

  11123. ** to sqlite3changeset_next() has advanced it, SQLITE_ROW is returned. 

  11124. ** Otherwise, if all changes in the changeset have already been visited,

  11125. ** SQLITE_DONE is returned.

  11126. **

  11127. ** If an error occurs, an SQLite error code is returned. Possible error 

  11128. ** codes include SQLITE_CORRUPT (if the changeset buffer is corrupt) or 

  11129. ** SQLITE_NOMEM.

  11130. */

  11131. SQLITE_API int sqlite3changeset_next(sqlite3_changeset_iter *pIter);

  11132. 

  11133. /*

  11134. ** CAPI3REF: Obtain The Current Operation From A Changeset Iterator

  11135. ** METHOD: sqlite3_changeset_iter

  11136. **

  11137. ** The pIter argument passed to this function may either be an iterator

  11138. ** passed to a conflict-handler by [sqlite3changeset_apply()], or an iterator

  11139. ** created by [sqlite3changeset_start()]. In the latter case, the most recent

  11140. ** call to [sqlite3changeset_next()] must have returned [SQLITE_ROW]. If this

  11141. ** is not the case, this function returns [SQLITE_MISUSE].

  11142. **

  11143. ** If argument pzTab is not NULL, then *pzTab is set to point to a

  11144. ** nul-terminated utf-8 encoded string containing the name of the table

  11145. ** affected by the current change. The buffer remains valid until either

  11146. ** sqlite3changeset_next() is called on the iterator or until the 

  11147. ** conflict-handler function returns. If pnCol is not NULL, then *pnCol is 

  11148. ** set to the number of columns in the table affected by the change. If

  11149. ** pbIndirect is not NULL, then *pbIndirect is set to true (1) if the change

  11150. ** is an indirect change, or false (0) otherwise. See the documentation for

  11151. ** [sqlite3session_indirect()] for a description of direct and indirect

  11152. ** changes. Finally, if pOp is not NULL, then *pOp is set to one of 

  11153. ** [SQLITE_INSERT], [SQLITE_DELETE] or [SQLITE_UPDATE], depending on the 

  11154. ** type of change that the iterator currently points to.

  11155. **

  11156. ** If no error occurs, SQLITE_OK is returned. If an error does occur, an

  11157. ** SQLite error code is returned. The values of the output variables may not

  11158. ** be trusted in this case.

  11159. */

  11160. SQLITE_API int sqlite3changeset_op(

  11161.   sqlite3_changeset_iter *pIter,  /* Iterator object */

  11162.   const char **pzTab,             /* OUT: Pointer to table name */

  11163.   int *pnCol,                     /* OUT: Number of columns in table */

  11164.   int *pOp,                       /* OUT: SQLITE_INSERT, DELETE or UPDATE */

  11165.   int *pbIndirect                 /* OUT: True for an 'indirect' change */

  11166. );

  11167. 

  11168. /*

  11169. ** CAPI3REF: Obtain The Primary Key Definition Of A Table

  11170. ** METHOD: sqlite3_changeset_iter

  11171. **

  11172. ** For each modified table, a changeset includes the following:

  11173. **

  11174. ** <ul>

  11175. **   <li> The number of columns in the table, and

  11176. **   <li> Which of those columns make up the tables PRIMARY KEY.

  11177. ** </ul>

  11178. **

  11179. ** This function is used to find which columns comprise the PRIMARY KEY of

  11180. ** the table modified by the change that iterator pIter currently points to.

  11181. ** If successful, *pabPK is set to point to an array of nCol entries, where

  11182. ** nCol is the number of columns in the table. Elements of *pabPK are set to

  11183. ** 0x01 if the corresponding column is part of the tables primary key, or

  11184. ** 0x00 if it is not.

  11185. **

  11186. ** If argument pnCol is not NULL, then *pnCol is set to the number of columns

  11187. ** in the table.

  11188. **

  11189. ** If this function is called when the iterator does not point to a valid

  11190. ** entry, SQLITE_MISUSE is returned and the output variables zeroed. Otherwise,

  11191. ** SQLITE_OK is returned and the output variables populated as described

  11192. ** above.

  11193. */

  11194. SQLITE_API int sqlite3changeset_pk(

  11195.   sqlite3_changeset_iter *pIter,  /* Iterator object */

  11196.   unsigned char **pabPK,          /* OUT: Array of boolean - true for PK cols */

  11197.   int *pnCol                      /* OUT: Number of entries in output array */

  11198. );

  11199. 

  11200. /*

  11201. ** CAPI3REF: Obtain old.* Values From A Changeset Iterator

  11202. ** METHOD: sqlite3_changeset_iter

  11203. **

  11204. ** The pIter argument passed to this function may either be an iterator

  11205. ** passed to a conflict-handler by [sqlite3changeset_apply()], or an iterator

  11206. ** created by [sqlite3changeset_start()]. In the latter case, the most recent

  11207. ** call to [sqlite3changeset_next()] must have returned SQLITE_ROW. 

  11208. ** Furthermore, it may only be called if the type of change that the iterator

  11209. ** currently points to is either [SQLITE_DELETE] or [SQLITE_UPDATE]. Otherwise,

  11210. ** this function returns [SQLITE_MISUSE] and sets *ppValue to NULL.

  11211. **

  11212. ** Argument iVal must be greater than or equal to 0, and less than the number

  11213. ** of columns in the table affected by the current change. Otherwise,

  11214. ** [SQLITE_RANGE] is returned and *ppValue is set to NULL.

  11215. **

  11216. ** If successful, this function sets *ppValue to point to a protected

  11217. ** sqlite3_value object containing the iVal'th value from the vector of 

  11218. ** original row values stored as part of the UPDATE or DELETE change and

  11219. ** returns SQLITE_OK. The name of the function comes from the fact that this 

  11220. ** is similar to the "old.*" columns available to update or delete triggers.

  11221. **

  11222. ** If some other error occurs (e.g. an OOM condition), an SQLite error code

  11223. ** is returned and *ppValue is set to NULL.

  11224. */

  11225. SQLITE_API int sqlite3changeset_old(

  11226.   sqlite3_changeset_iter *pIter,  /* Changeset iterator */

  11227.   int iVal,                       /* Column number */

  11228.   sqlite3_value **ppValue         /* OUT: Old value (or NULL pointer) */

  11229. );

  11230. 

  11231. /*

  11232. ** CAPI3REF: Obtain new.* Values From A Changeset Iterator

  11233. ** METHOD: sqlite3_changeset_iter

  11234. **

  11235. ** The pIter argument passed to this function may either be an iterator

  11236. ** passed to a conflict-handler by [sqlite3changeset_apply()], or an iterator

  11237. ** created by [sqlite3changeset_start()]. In the latter case, the most recent

  11238. ** call to [sqlite3changeset_next()] must have returned SQLITE_ROW. 

  11239. ** Furthermore, it may only be called if the type of change that the iterator

  11240. ** currently points to is either [SQLITE_UPDATE] or [SQLITE_INSERT]. Otherwise,

  11241. ** this function returns [SQLITE_MISUSE] and sets *ppValue to NULL.

  11242. **

  11243. ** Argument iVal must be greater than or equal to 0, and less than the number

  11244. ** of columns in the table affected by the current change. Otherwise,

  11245. ** [SQLITE_RANGE] is returned and *ppValue is set to NULL.

  11246. **

  11247. ** If successful, this function sets *ppValue to point to a protected

  11248. ** sqlite3_value object containing the iVal'th value from the vector of 

  11249. ** new row values stored as part of the UPDATE or INSERT change and

  11250. ** returns SQLITE_OK. If the change is an UPDATE and does not include

  11251. ** a new value for the requested column, *ppValue is set to NULL and 

  11252. ** SQLITE_OK returned. The name of the function comes from the fact that 

  11253. ** this is similar to the "new.*" columns available to update or delete 

  11254. ** triggers.

  11255. **

  11256. ** If some other error occurs (e.g. an OOM condition), an SQLite error code

  11257. ** is returned and *ppValue is set to NULL.

  11258. */

  11259. SQLITE_API int sqlite3changeset_new(

  11260.   sqlite3_changeset_iter *pIter,  /* Changeset iterator */

  11261.   int iVal,                       /* Column number */

  11262.   sqlite3_value **ppValue         /* OUT: New value (or NULL pointer) */

  11263. );

  11264. 

  11265. /*

  11266. ** CAPI3REF: Obtain Conflicting Row Values From A Changeset Iterator

  11267. ** METHOD: sqlite3_changeset_iter

  11268. **

  11269. ** This function should only be used with iterator objects passed to a

  11270. ** conflict-handler callback by [sqlite3changeset_apply()] with either

  11271. ** [SQLITE_CHANGESET_DATA] or [SQLITE_CHANGESET_CONFLICT]. If this function

  11272. ** is called on any other iterator, [SQLITE_MISUSE] is returned and *ppValue

  11273. ** is set to NULL.

  11274. **

  11275. ** Argument iVal must be greater than or equal to 0, and less than the number

  11276. ** of columns in the table affected by the current change. Otherwise,

  11277. ** [SQLITE_RANGE] is returned and *ppValue is set to NULL.

  11278. **

  11279. ** If successful, this function sets *ppValue to point to a protected

  11280. ** sqlite3_value object containing the iVal'th value from the 

  11281. ** "conflicting row" associated with the current conflict-handler callback

  11282. ** and returns SQLITE_OK.

  11283. **

  11284. ** If some other error occurs (e.g. an OOM condition), an SQLite error code

  11285. ** is returned and *ppValue is set to NULL.

  11286. */

  11287. SQLITE_API int sqlite3changeset_conflict(

  11288.   sqlite3_changeset_iter *pIter,  /* Changeset iterator */

  11289.   int iVal,                       /* Column number */

  11290.   sqlite3_value **ppValue         /* OUT: Value from conflicting row */

  11291. );

  11292. 

  11293. /*

  11294. ** CAPI3REF: Determine The Number Of Foreign Key Constraint Violations

  11295. ** METHOD: sqlite3_changeset_iter

  11296. **

  11297. ** This function may only be called with an iterator passed to an

  11298. ** SQLITE_CHANGESET_FOREIGN_KEY conflict handler callback. In this case

  11299. ** it sets the output variable to the total number of known foreign key

  11300. ** violations in the destination database and returns SQLITE_OK.

  11301. **

  11302. ** In all other cases this function returns SQLITE_MISUSE.

  11303. */

  11304. SQLITE_API int sqlite3changeset_fk_conflicts(

  11305.   sqlite3_changeset_iter *pIter,  /* Changeset iterator */

  11306.   int *pnOut                      /* OUT: Number of FK violations */

  11307. );

  11308. 

  11309. 

  11310. /*

  11311. ** CAPI3REF: Finalize A Changeset Iterator

  11312. ** METHOD: sqlite3_changeset_iter

  11313. **

  11314. ** This function is used to finalize an iterator allocated with

  11315. ** [sqlite3changeset_start()].

  11316. **

  11317. ** This function should only be called on iterators created using the

  11318. ** [sqlite3changeset_start()] function. If an application calls this

  11319. ** function with an iterator passed to a conflict-handler by

  11320. ** [sqlite3changeset_apply()], [SQLITE_MISUSE] is immediately returned and the

  11321. ** call has no effect.

  11322. **

  11323. ** If an error was encountered within a call to an sqlite3changeset_xxx()

  11324. ** function (for example an [SQLITE_CORRUPT] in [sqlite3changeset_next()] or an 

  11325. ** [SQLITE_NOMEM] in [sqlite3changeset_new()]) then an error code corresponding

  11326. ** to that error is returned by this function. Otherwise, SQLITE_OK is

  11327. ** returned. This is to allow the following pattern (pseudo-code):

  11328. **

  11329. ** <pre>

  11330. **   sqlite3changeset_start();

  11331. **   while( SQLITE_ROW==sqlite3changeset_next() ){

  11332. **     // Do something with change.

  11333. **   }

  11334. **   rc = sqlite3changeset_finalize();

  11335. **   if( rc!=SQLITE_OK ){

  11336. **     // An error has occurred 

  11337. **   }

  11338. ** </pre>

  11339. */

  11340. SQLITE_API int sqlite3changeset_finalize(sqlite3_changeset_iter *pIter);

  11341. 

  11342. /*

  11343. ** CAPI3REF: Invert A Changeset

  11344. **

  11345. ** This function is used to "invert" a changeset object. Applying an inverted

  11346. ** changeset to a database reverses the effects of applying the uninverted

  11347. ** changeset. Specifically:

  11348. **

  11349. ** <ul>

  11350. **   <li> Each DELETE change is changed to an INSERT, and

  11351. **   <li> Each INSERT change is changed to a DELETE, and

  11352. **   <li> For each UPDATE change, the old.* and new.* values are exchanged.

  11353. ** </ul>

  11354. **

  11355. ** This function does not change the order in which changes appear within

  11356. ** the changeset. It merely reverses the sense of each individual change.

  11357. **

  11358. ** If successful, a pointer to a buffer containing the inverted changeset

  11359. ** is stored in *ppOut, the size of the same buffer is stored in *pnOut, and

  11360. ** SQLITE_OK is returned. If an error occurs, both *pnOut and *ppOut are

  11361. ** zeroed and an SQLite error code returned.

  11362. **

  11363. ** It is the responsibility of the caller to eventually call sqlite3_free()

  11364. ** on the *ppOut pointer to free the buffer allocation following a successful 

  11365. ** call to this function.

  11366. **

  11367. ** WARNING/TODO: This function currently assumes that the input is a valid

  11368. ** changeset. If it is not, the results are undefined.

  11369. */

  11370. SQLITE_API int sqlite3changeset_invert(

  11371.   int nIn, const void *pIn,       /* Input changeset */

  11372.   int *pnOut, void **ppOut        /* OUT: Inverse of input */

  11373. );

  11374. 

  11375. /*

  11376. ** CAPI3REF: Concatenate Two Changeset Objects

  11377. **

  11378. ** This function is used to concatenate two changesets, A and B, into a 

  11379. ** single changeset. The result is a changeset equivalent to applying

  11380. ** changeset A followed by changeset B. 

  11381. **

  11382. ** This function combines the two input changesets using an 

  11383. ** sqlite3_changegroup object. Calling it produces similar results as the

  11384. ** following code fragment:

  11385. **

  11386. ** <pre>

  11387. **   sqlite3_changegroup *pGrp;

  11388. **   rc = sqlite3_changegroup_new(&pGrp);

  11389. **   if( rc==SQLITE_OK ) rc = sqlite3changegroup_add(pGrp, nA, pA);

  11390. **   if( rc==SQLITE_OK ) rc = sqlite3changegroup_add(pGrp, nB, pB);

  11391. **   if( rc==SQLITE_OK ){

  11392. **     rc = sqlite3changegroup_output(pGrp, pnOut, ppOut);

  11393. **   }else{

  11394. **     *ppOut = 0;

  11395. **     *pnOut = 0;

  11396. **   }

  11397. ** </pre>

  11398. **

  11399. ** Refer to the sqlite3_changegroup documentation below for details.

  11400. */

  11401. SQLITE_API int sqlite3changeset_concat(

  11402.   int nA,                         /* Number of bytes in buffer pA */

  11403.   void *pA,                       /* Pointer to buffer containing changeset A */

  11404.   int nB,                         /* Number of bytes in buffer pB */

  11405.   void *pB,                       /* Pointer to buffer containing changeset B */

  11406.   int *pnOut,                     /* OUT: Number of bytes in output changeset */

  11407.   void **ppOut                    /* OUT: Buffer containing output changeset */

  11408. );

  11409. 

  11410. 

  11411. /*

  11412. ** CAPI3REF: Changegroup Handle

  11413. **

  11414. ** A changegroup is an object used to combine two or more 

  11415. ** [changesets] or [patchsets]

  11416. */

  11417. typedef struct sqlite3_changegroup sqlite3_changegroup;

  11418. 

  11419. /*

  11420. ** CAPI3REF: Create A New Changegroup Object

  11421. ** CONSTRUCTOR: sqlite3_changegroup

  11422. **

  11423. ** An sqlite3_changegroup object is used to combine two or more changesets

  11424. ** (or patchsets) into a single changeset (or patchset). A single changegroup

  11425. ** object may combine changesets or patchsets, but not both. The output is

  11426. ** always in the same format as the input.

  11427. **

  11428. ** If successful, this function returns SQLITE_OK and populates (*pp) with

  11429. ** a pointer to a new sqlite3_changegroup object before returning. The caller

  11430. ** should eventually free the returned object using a call to 

  11431. ** sqlite3changegroup_delete(). If an error occurs, an SQLite error code

  11432. ** (i.e. SQLITE_NOMEM) is returned and *pp is set to NULL.

  11433. **

  11434. ** The usual usage pattern for an sqlite3_changegroup object is as follows:

  11435. **

  11436. ** <ul>

  11437. **   <li> It is created using a call to sqlite3changegroup_new().

  11438. **

  11439. **   <li> Zero or more changesets (or patchsets) are added to the object

  11440. **        by calling sqlite3changegroup_add().

  11441. **

  11442. **   <li> The result of combining all input changesets together is obtained 

  11443. **        by the application via a call to sqlite3changegroup_output().

  11444. **

  11445. **   <li> The object is deleted using a call to sqlite3changegroup_delete().

  11446. ** </ul>

  11447. **

  11448. ** Any number of calls to add() and output() may be made between the calls to

  11449. ** new() and delete(), and in any order.

  11450. **

  11451. ** As well as the regular sqlite3changegroup_add() and 

  11452. ** sqlite3changegroup_output() functions, also available are the streaming

  11453. ** versions sqlite3changegroup_add_strm() and sqlite3changegroup_output_strm().

  11454. */

  11455. SQLITE_API int sqlite3changegroup_new(sqlite3_changegroup **pp);

  11456. 

  11457. /*

  11458. ** CAPI3REF: Add A Changeset To A Changegroup

  11459. ** METHOD: sqlite3_changegroup

  11460. **

  11461. ** Add all changes within the changeset (or patchset) in buffer pData (size

  11462. ** nData bytes) to the changegroup. 

  11463. **

  11464. ** If the buffer contains a patchset, then all prior calls to this function

  11465. ** on the same changegroup object must also have specified patchsets. Or, if

  11466. ** the buffer contains a changeset, so must have the earlier calls to this

  11467. ** function. Otherwise, SQLITE_ERROR is returned and no changes are added

  11468. ** to the changegroup.

  11469. **

  11470. ** Rows within the changeset and changegroup are identified by the values in

  11471. ** their PRIMARY KEY columns. A change in the changeset is considered to

  11472. ** apply to the same row as a change already present in the changegroup if

  11473. ** the two rows have the same primary key.

  11474. **

  11475. ** Changes to rows that do not already appear in the changegroup are

  11476. ** simply copied into it. Or, if both the new changeset and the changegroup

  11477. ** contain changes that apply to a single row, the final contents of the

  11478. ** changegroup depends on the type of each change, as follows:

  11479. **

  11480. ** <table border=1 style="margin-left:8ex;margin-right:8ex">

  11481. **   <tr><th style="white-space:pre">Existing Change  </th>

  11482. **       <th style="white-space:pre">New Change       </th>

  11483. **       <th>Output Change

  11484. **   <tr><td>INSERT <td>INSERT <td>

  11485. **       The new change is ignored. This case does not occur if the new

  11486. **       changeset was recorded immediately after the changesets already

  11487. **       added to the changegroup.

  11488. **   <tr><td>INSERT <td>UPDATE <td>

  11489. **       The INSERT change remains in the changegroup. The values in the 

  11490. **       INSERT change are modified as if the row was inserted by the

  11491. **       existing change and then updated according to the new change.

  11492. **   <tr><td>INSERT <td>DELETE <td>

  11493. **       The existing INSERT is removed from the changegroup. The DELETE is

  11494. **       not added.

  11495. **   <tr><td>UPDATE <td>INSERT <td>

  11496. **       The new change is ignored. This case does not occur if the new

  11497. **       changeset was recorded immediately after the changesets already

  11498. **       added to the changegroup.

  11499. **   <tr><td>UPDATE <td>UPDATE <td>

  11500. **       The existing UPDATE remains within the changegroup. It is amended 

  11501. **       so that the accompanying values are as if the row was updated once 

  11502. **       by the existing change and then again by the new change.

  11503. **   <tr><td>UPDATE <td>DELETE <td>

  11504. **       The existing UPDATE is replaced by the new DELETE within the

  11505. **       changegroup.

  11506. **   <tr><td>DELETE <td>INSERT <td>

  11507. **       If one or more of the column values in the row inserted by the

  11508. **       new change differ from those in the row deleted by the existing 

  11509. **       change, the existing DELETE is replaced by an UPDATE within the

  11510. **       changegroup. Otherwise, if the inserted row is exactly the same 

  11511. **       as the deleted row, the existing DELETE is simply discarded.

  11512. **   <tr><td>DELETE <td>UPDATE <td>

  11513. **       The new change is ignored. This case does not occur if the new

  11514. **       changeset was recorded immediately after the changesets already

  11515. **       added to the changegroup.

  11516. **   <tr><td>DELETE <td>DELETE <td>

  11517. **       The new change is ignored. This case does not occur if the new

  11518. **       changeset was recorded immediately after the changesets already

  11519. **       added to the changegroup.

  11520. ** </table>

  11521. **

  11522. ** If the new changeset contains changes to a table that is already present

  11523. ** in the changegroup, then the number of columns and the position of the

  11524. ** primary key columns for the table must be consistent. If this is not the

  11525. ** case, this function fails with SQLITE_SCHEMA. If the input changeset

  11526. ** appears to be corrupt and the corruption is detected, SQLITE_CORRUPT is

  11527. ** returned. Or, if an out-of-memory condition occurs during processing, this

  11528. ** function returns SQLITE_NOMEM. In all cases, if an error occurs the

  11529. ** final contents of the changegroup is undefined.

  11530. **

  11531. ** If no error occurs, SQLITE_OK is returned.

  11532. */

  11533. SQLITE_API int sqlite3changegroup_add(sqlite3_changegroup*, int nData, void *pData);

  11534. 

  11535. /*

  11536. ** CAPI3REF: Obtain A Composite Changeset From A Changegroup

  11537. ** METHOD: sqlite3_changegroup

  11538. **

  11539. ** Obtain a buffer containing a changeset (or patchset) representing the

  11540. ** current contents of the changegroup. If the inputs to the changegroup

  11541. ** were themselves changesets, the output is a changeset. Or, if the

  11542. ** inputs were patchsets, the output is also a patchset.

  11543. **

  11544. ** As with the output of the sqlite3session_changeset() and

  11545. ** sqlite3session_patchset() functions, all changes related to a single

  11546. ** table are grouped together in the output of this function. Tables appear

  11547. ** in the same order as for the very first changeset added to the changegroup.

  11548. ** If the second or subsequent changesets added to the changegroup contain

  11549. ** changes for tables that do not appear in the first changeset, they are

  11550. ** appended onto the end of the output changeset, again in the order in

  11551. ** which they are first encountered.

  11552. **

  11553. ** If an error occurs, an SQLite error code is returned and the output

  11554. ** variables (*pnData) and (*ppData) are set to 0. Otherwise, SQLITE_OK

  11555. ** is returned and the output variables are set to the size of and a 

  11556. ** pointer to the output buffer, respectively. In this case it is the

  11557. ** responsibility of the caller to eventually free the buffer using a

  11558. ** call to sqlite3_free().

  11559. */

  11560. SQLITE_API int sqlite3changegroup_output(

  11561.   sqlite3_changegroup*,

  11562.   int *pnData,                    /* OUT: Size of output buffer in bytes */

  11563.   void **ppData                   /* OUT: Pointer to output buffer */

  11564. );

  11565. 

  11566. /*

  11567. ** CAPI3REF: Delete A Changegroup Object

  11568. ** DESTRUCTOR: sqlite3_changegroup

  11569. */

  11570. SQLITE_API void sqlite3changegroup_delete(sqlite3_changegroup*);

  11571. 

  11572. /*

  11573. ** CAPI3REF: Apply A Changeset To A Database

  11574. **

  11575. ** Apply a changeset or patchset to a database. These functions attempt to

  11576. ** update the "main" database attached to handle db with the changes found in

  11577. ** the changeset passed via the second and third arguments. 

  11578. **

  11579. ** The fourth argument (xFilter) passed to these functions is the "filter

  11580. ** callback". If it is not NULL, then for each table affected by at least one

  11581. ** change in the changeset, the filter callback is invoked with

  11582. ** the table name as the second argument, and a copy of the context pointer

  11583. ** passed as the sixth argument as the first. If the "filter callback"

  11584. ** returns zero, then no attempt is made to apply any changes to the table.

  11585. ** Otherwise, if the return value is non-zero or the xFilter argument to

  11586. ** is NULL, all changes related to the table are attempted.

  11587. **

  11588. ** For each table that is not excluded by the filter callback, this function 

  11589. ** tests that the target database contains a compatible table. A table is 

  11590. ** considered compatible if all of the following are true:

  11591. **

  11592. ** <ul>

  11593. **   <li> The table has the same name as the name recorded in the 

  11594. **        changeset, and

  11595. **   <li> The table has at least as many columns as recorded in the 

  11596. **        changeset, and

  11597. **   <li> The table has primary key columns in the same position as 

  11598. **        recorded in the changeset.

  11599. ** </ul>

  11600. **

  11601. ** If there is no compatible table, it is not an error, but none of the

  11602. ** changes associated with the table are applied. A warning message is issued

  11603. ** via the sqlite3_log() mechanism with the error code SQLITE_SCHEMA. At most

  11604. ** one such warning is issued for each table in the changeset.

  11605. **

  11606. ** For each change for which there is a compatible table, an attempt is made 

  11607. ** to modify the table contents according to the UPDATE, INSERT or DELETE 

  11608. ** change. If a change cannot be applied cleanly, the conflict handler 

  11609. ** function passed as the fifth argument to sqlite3changeset_apply() may be 

  11610. ** invoked. A description of exactly when the conflict handler is invoked for 

  11611. ** each type of change is below.

  11612. **

  11613. ** Unlike the xFilter argument, xConflict may not be passed NULL. The results

  11614. ** of passing anything other than a valid function pointer as the xConflict

  11615. ** argument are undefined.

  11616. **

  11617. ** Each time the conflict handler function is invoked, it must return one

  11618. ** of [SQLITE_CHANGESET_OMIT], [SQLITE_CHANGESET_ABORT] or 

  11619. ** [SQLITE_CHANGESET_REPLACE]. SQLITE_CHANGESET_REPLACE may only be returned

  11620. ** if the second argument passed to the conflict handler is either

  11621. ** SQLITE_CHANGESET_DATA or SQLITE_CHANGESET_CONFLICT. If the conflict-handler

  11622. ** returns an illegal value, any changes already made are rolled back and

  11623. ** the call to sqlite3changeset_apply() returns SQLITE_MISUSE. Different 

  11624. ** actions are taken by sqlite3changeset_apply() depending on the value

  11625. ** returned by each invocation of the conflict-handler function. Refer to

  11626. ** the documentation for the three 

  11627. ** [SQLITE_CHANGESET_OMIT|available return values] for details.

  11628. **

  11629. ** <dl>

  11630. ** <dt>DELETE Changes<dd>

  11631. **   For each DELETE change, the function checks if the target database 

  11632. **   contains a row with the same primary key value (or values) as the 

  11633. **   original row values stored in the changeset. If it does, and the values 

  11634. **   stored in all non-primary key columns also match the values stored in 

  11635. **   the changeset the row is deleted from the target database.

  11636. **

  11637. **   If a row with matching primary key values is found, but one or more of

  11638. **   the non-primary key fields contains a value different from the original

  11639. **   row value stored in the changeset, the conflict-handler function is

  11640. **   invoked with [SQLITE_CHANGESET_DATA] as the second argument. If the

  11641. **   database table has more columns than are recorded in the changeset,

  11642. **   only the values of those non-primary key fields are compared against

  11643. **   the current database contents - any trailing database table columns

  11644. **   are ignored.

  11645. **

  11646. **   If no row with matching primary key values is found in the database,

  11647. **   the conflict-handler function is invoked with [SQLITE_CHANGESET_NOTFOUND]

  11648. **   passed as the second argument.

  11649. **

  11650. **   If the DELETE operation is attempted, but SQLite returns SQLITE_CONSTRAINT

  11651. **   (which can only happen if a foreign key constraint is violated), the

  11652. **   conflict-handler function is invoked with [SQLITE_CHANGESET_CONSTRAINT]

  11653. **   passed as the second argument. This includes the case where the DELETE

  11654. **   operation is attempted because an earlier call to the conflict handler

  11655. **   function returned [SQLITE_CHANGESET_REPLACE].

  11656. **

  11657. ** <dt>INSERT Changes<dd>

  11658. **   For each INSERT change, an attempt is made to insert the new row into

  11659. **   the database. If the changeset row contains fewer fields than the

  11660. **   database table, the trailing fields are populated with their default

  11661. **   values.

  11662. **

  11663. **   If the attempt to insert the row fails because the database already 

  11664. **   contains a row with the same primary key values, the conflict handler

  11665. **   function is invoked with the second argument set to 

  11666. **   [SQLITE_CHANGESET_CONFLICT].

  11667. **

  11668. **   If the attempt to insert the row fails because of some other constraint

  11669. **   violation (e.g. NOT NULL or UNIQUE), the conflict handler function is 

  11670. **   invoked with the second argument set to [SQLITE_CHANGESET_CONSTRAINT].

  11671. **   This includes the case where the INSERT operation is re-attempted because 

  11672. **   an earlier call to the conflict handler function returned 

  11673. **   [SQLITE_CHANGESET_REPLACE].

  11674. **

  11675. ** <dt>UPDATE Changes<dd>

  11676. **   For each UPDATE change, the function checks if the target database 

  11677. **   contains a row with the same primary key value (or values) as the 

  11678. **   original row values stored in the changeset. If it does, and the values 

  11679. **   stored in all modified non-primary key columns also match the values

  11680. **   stored in the changeset the row is updated within the target database.

  11681. **

  11682. **   If a row with matching primary key values is found, but one or more of

  11683. **   the modified non-primary key fields contains a value different from an

  11684. **   original row value stored in the changeset, the conflict-handler function

  11685. **   is invoked with [SQLITE_CHANGESET_DATA] as the second argument. Since

  11686. **   UPDATE changes only contain values for non-primary key fields that are

  11687. **   to be modified, only those fields need to match the original values to

  11688. **   avoid the SQLITE_CHANGESET_DATA conflict-handler callback.

  11689. **

  11690. **   If no row with matching primary key values is found in the database,

  11691. **   the conflict-handler function is invoked with [SQLITE_CHANGESET_NOTFOUND]

  11692. **   passed as the second argument.

  11693. **

  11694. **   If the UPDATE operation is attempted, but SQLite returns 

  11695. **   SQLITE_CONSTRAINT, the conflict-handler function is invoked with 

  11696. **   [SQLITE_CHANGESET_CONSTRAINT] passed as the second argument.

  11697. **   This includes the case where the UPDATE operation is attempted after 

  11698. **   an earlier call to the conflict handler function returned

  11699. **   [SQLITE_CHANGESET_REPLACE].  

  11700. ** </dl>

  11701. **

  11702. ** It is safe to execute SQL statements, including those that write to the

  11703. ** table that the callback related to, from within the xConflict callback.

  11704. ** This can be used to further customize the applications conflict

  11705. ** resolution strategy.

  11706. **

  11707. ** All changes made by these functions are enclosed in a savepoint transaction.

  11708. ** If any other error (aside from a constraint failure when attempting to

  11709. ** write to the target database) occurs, then the savepoint transaction is

  11710. ** rolled back, restoring the target database to its original state, and an 

  11711. ** SQLite error code returned.

  11712. **

  11713. ** If the output parameters (ppRebase) and (pnRebase) are non-NULL and

  11714. ** the input is a changeset (not a patchset), then sqlite3changeset_apply_v2()

  11715. ** may set (*ppRebase) to point to a "rebase" that may be used with the 

  11716. ** sqlite3_rebaser APIs buffer before returning. In this case (*pnRebase)

  11717. ** is set to the size of the buffer in bytes. It is the responsibility of the

  11718. ** caller to eventually free any such buffer using sqlite3_free(). The buffer

  11719. ** is only allocated and populated if one or more conflicts were encountered

  11720. ** while applying the patchset. See comments surrounding the sqlite3_rebaser

  11721. ** APIs for further details.

  11722. **

  11723. ** The behavior of sqlite3changeset_apply_v2() and its streaming equivalent

  11724. ** may be modified by passing a combination of

  11725. ** [SQLITE_CHANGESETAPPLY_NOSAVEPOINT | supported flags] as the 9th parameter.

  11726. **

  11727. ** Note that the sqlite3changeset_apply_v2() API is still <b>experimental</b>

  11728. ** and therefore subject to change.

  11729. */

  11730. SQLITE_API int sqlite3changeset_apply(

  11731.   sqlite3 *db,                    /* Apply change to "main" db of this handle */

  11732.   int nChangeset,                 /* Size of changeset in bytes */

  11733.   void *pChangeset,               /* Changeset blob */

  11734.   int(*xFilter)(

  11735.     void *pCtx,                   /* Copy of sixth arg to _apply() */

  11736.     const char *zTab              /* Table name */

  11737.   ),

  11738.   int(*xConflict)(

  11739.     void *pCtx,                   /* Copy of sixth arg to _apply() */

  11740.     int eConflict,                /* DATA, MISSING, CONFLICT, CONSTRAINT */

  11741.     sqlite3_changeset_iter *p     /* Handle describing change and conflict */

  11742.   ),

  11743.   void *pCtx                      /* First argument passed to xConflict */

  11744. );

  11745. SQLITE_API int sqlite3changeset_apply_v2(

  11746.   sqlite3 *db,                    /* Apply change to "main" db of this handle */

  11747.   int nChangeset,                 /* Size of changeset in bytes */

  11748.   void *pChangeset,               /* Changeset blob */

  11749.   int(*xFilter)(

  11750.     void *pCtx,                   /* Copy of sixth arg to _apply() */

  11751.     const char *zTab              /* Table name */

  11752.   ),

  11753.   int(*xConflict)(

  11754.     void *pCtx,                   /* Copy of sixth arg to _apply() */

  11755.     int eConflict,                /* DATA, MISSING, CONFLICT, CONSTRAINT */

  11756.     sqlite3_changeset_iter *p     /* Handle describing change and conflict */

  11757.   ),

  11758.   void *pCtx,                     /* First argument passed to xConflict */

  11759.   void **ppRebase, int *pnRebase, /* OUT: Rebase data */

  11760.   int flags                       /* SESSION_CHANGESETAPPLY_* flags */

  11761. );

  11762. 

  11763. /*

  11764. ** CAPI3REF: Flags for sqlite3changeset_apply_v2

  11765. **

  11766. ** The following flags may passed via the 9th parameter to

  11767. ** [sqlite3changeset_apply_v2] and [sqlite3changeset_apply_v2_strm]:

  11768. **

  11769. ** <dl>

  11770. ** <dt>SQLITE_CHANGESETAPPLY_NOSAVEPOINT <dd>

  11771. **   Usually, the sessions module encloses all operations performed by

  11772. **   a single call to apply_v2() or apply_v2_strm() in a [SAVEPOINT]. The

  11773. **   SAVEPOINT is committed if the changeset or patchset is successfully

  11774. **   applied, or rolled back if an error occurs. Specifying this flag

  11775. **   causes the sessions module to omit this savepoint. In this case, if the

  11776. **   caller has an open transaction or savepoint when apply_v2() is called, 

  11777. **   it may revert the partially applied changeset by rolling it back.

  11778. **

  11779. ** <dt>SQLITE_CHANGESETAPPLY_INVERT <dd>

  11780. **   Invert the changeset before applying it. This is equivalent to inverting

  11781. **   a changeset using sqlite3changeset_invert() before applying it. It is

  11782. **   an error to specify this flag with a patchset.

  11783. */

  11784. #define SQLITE_CHANGESETAPPLY_NOSAVEPOINT   0x0001

  11785. #define SQLITE_CHANGESETAPPLY_INVERT        0x0002

  11786. 

  11787. /* 

  11788. ** CAPI3REF: Constants Passed To The Conflict Handler

  11789. **

  11790. ** Values that may be passed as the second argument to a conflict-handler.

  11791. **

  11792. ** <dl>

  11793. ** <dt>SQLITE_CHANGESET_DATA<dd>

  11794. **   The conflict handler is invoked with CHANGESET_DATA as the second argument

  11795. **   when processing a DELETE or UPDATE change if a row with the required

  11796. **   PRIMARY KEY fields is present in the database, but one or more other 

  11797. **   (non primary-key) fields modified by the update do not contain the 

  11798. **   expected "before" values.

  11799. ** 

  11800. **   The conflicting row, in this case, is the database row with the matching

  11801. **   primary key.

  11802. ** 

  11803. ** <dt>SQLITE_CHANGESET_NOTFOUND<dd>

  11804. **   The conflict handler is invoked with CHANGESET_NOTFOUND as the second

  11805. **   argument when processing a DELETE or UPDATE change if a row with the

  11806. **   required PRIMARY KEY fields is not present in the database.

  11807. ** 

  11808. **   There is no conflicting row in this case. The results of invoking the

  11809. **   sqlite3changeset_conflict() API are undefined.

  11810. ** 

  11811. ** <dt>SQLITE_CHANGESET_CONFLICT<dd>

  11812. **   CHANGESET_CONFLICT is passed as the second argument to the conflict

  11813. **   handler while processing an INSERT change if the operation would result 

  11814. **   in duplicate primary key values.

  11815. ** 

  11816. **   The conflicting row in this case is the database row with the matching

  11817. **   primary key.

  11818. **

  11819. ** <dt>SQLITE_CHANGESET_FOREIGN_KEY<dd>

  11820. **   If foreign key handling is enabled, and applying a changeset leaves the

  11821. **   database in a state containing foreign key violations, the conflict 

  11822. **   handler is invoked with CHANGESET_FOREIGN_KEY as the second argument

  11823. **   exactly once before the changeset is committed. If the conflict handler

  11824. **   returns CHANGESET_OMIT, the changes, including those that caused the

  11825. **   foreign key constraint violation, are committed. Or, if it returns

  11826. **   CHANGESET_ABORT, the changeset is rolled back.

  11827. **

  11828. **   No current or conflicting row information is provided. The only function

  11829. **   it is possible to call on the supplied sqlite3_changeset_iter handle

  11830. **   is sqlite3changeset_fk_conflicts().

  11831. ** 

  11832. ** <dt>SQLITE_CHANGESET_CONSTRAINT<dd>

  11833. **   If any other constraint violation occurs while applying a change (i.e. 

  11834. **   a UNIQUE, CHECK or NOT NULL constraint), the conflict handler is 

  11835. **   invoked with CHANGESET_CONSTRAINT as the second argument.

  11836. ** 

  11837. **   There is no conflicting row in this case. The results of invoking the

  11838. **   sqlite3changeset_conflict() API are undefined.

  11839. **

  11840. ** </dl>

  11841. */

  11842. #define SQLITE_CHANGESET_DATA        1

  11843. #define SQLITE_CHANGESET_NOTFOUND    2

  11844. #define SQLITE_CHANGESET_CONFLICT    3

  11845. #define SQLITE_CHANGESET_CONSTRAINT  4

  11846. #define SQLITE_CHANGESET_FOREIGN_KEY 5

  11847. 

  11848. /* 

  11849. ** CAPI3REF: Constants Returned By The Conflict Handler

  11850. **

  11851. ** A conflict handler callback must return one of the following three values.

  11852. **

  11853. ** <dl>

  11854. ** <dt>SQLITE_CHANGESET_OMIT<dd>

  11855. **   If a conflict handler returns this value no special action is taken. The

  11856. **   change that caused the conflict is not applied. The session module 

  11857. **   continues to the next change in the changeset.

  11858. **

  11859. ** <dt>SQLITE_CHANGESET_REPLACE<dd>

  11860. **   This value may only be returned if the second argument to the conflict

  11861. **   handler was SQLITE_CHANGESET_DATA or SQLITE_CHANGESET_CONFLICT. If this

  11862. **   is not the case, any changes applied so far are rolled back and the 

  11863. **   call to sqlite3changeset_apply() returns SQLITE_MISUSE.

  11864. **

  11865. **   If CHANGESET_REPLACE is returned by an SQLITE_CHANGESET_DATA conflict

  11866. **   handler, then the conflicting row is either updated or deleted, depending

  11867. **   on the type of change.

  11868. **

  11869. **   If CHANGESET_REPLACE is returned by an SQLITE_CHANGESET_CONFLICT conflict

  11870. **   handler, then the conflicting row is removed from the database and a

  11871. **   second attempt to apply the change is made. If this second attempt fails,

  11872. **   the original row is restored to the database before continuing.

  11873. **

  11874. ** <dt>SQLITE_CHANGESET_ABORT<dd>

  11875. **   If this value is returned, any changes applied so far are rolled back 

  11876. **   and the call to sqlite3changeset_apply() returns SQLITE_ABORT.

  11877. ** </dl>

  11878. */

  11879. #define SQLITE_CHANGESET_OMIT       0

  11880. #define SQLITE_CHANGESET_REPLACE    1

  11881. #define SQLITE_CHANGESET_ABORT      2

  11882. 

  11883. /* 

  11884. ** CAPI3REF: Rebasing changesets

  11885. ** EXPERIMENTAL

  11886. **

  11887. ** Suppose there is a site hosting a database in state S0. And that

  11888. ** modifications are made that move that database to state S1 and a

  11889. ** changeset recorded (the "local" changeset). Then, a changeset based

  11890. ** on S0 is received from another site (the "remote" changeset) and 

  11891. ** applied to the database. The database is then in state 

  11892. ** (S1+"remote"), where the exact state depends on any conflict

  11893. ** resolution decisions (OMIT or REPLACE) made while applying "remote".

  11894. ** Rebasing a changeset is to update it to take those conflict 

  11895. ** resolution decisions into account, so that the same conflicts

  11896. ** do not have to be resolved elsewhere in the network. 

  11897. **

  11898. ** For example, if both the local and remote changesets contain an

  11899. ** INSERT of the same key on "CREATE TABLE t1(a PRIMARY KEY, b)":

  11900. **

  11901. **   local:  INSERT INTO t1 VALUES(1, 'v1');

  11902. **   remote: INSERT INTO t1 VALUES(1, 'v2');

  11903. **

  11904. ** and the conflict resolution is REPLACE, then the INSERT change is

  11905. ** removed from the local changeset (it was overridden). Or, if the

  11906. ** conflict resolution was "OMIT", then the local changeset is modified

  11907. ** to instead contain:

  11908. **

  11909. **           UPDATE t1 SET b = 'v2' WHERE a=1;

  11910. **

  11911. ** Changes within the local changeset are rebased as follows:

  11912. **

  11913. ** <dl>

  11914. ** <dt>Local INSERT<dd>

  11915. **   This may only conflict with a remote INSERT. If the conflict 

  11916. **   resolution was OMIT, then add an UPDATE change to the rebased

  11917. **   changeset. Or, if the conflict resolution was REPLACE, add

  11918. **   nothing to the rebased changeset.

  11919. **

  11920. ** <dt>Local DELETE<dd>

  11921. **   This may conflict with a remote UPDATE or DELETE. In both cases the

  11922. **   only possible resolution is OMIT. If the remote operation was a

  11923. **   DELETE, then add no change to the rebased changeset. If the remote

  11924. **   operation was an UPDATE, then the old.* fields of change are updated

  11925. **   to reflect the new.* values in the UPDATE.

  11926. **

  11927. ** <dt>Local UPDATE<dd>

  11928. **   This may conflict with a remote UPDATE or DELETE. If it conflicts

  11929. **   with a DELETE, and the conflict resolution was OMIT, then the update

  11930. **   is changed into an INSERT. Any undefined values in the new.* record

  11931. **   from the update change are filled in using the old.* values from

  11932. **   the conflicting DELETE. Or, if the conflict resolution was REPLACE,

  11933. **   the UPDATE change is simply omitted from the rebased changeset.

  11934. **

  11935. **   If conflict is with a remote UPDATE and the resolution is OMIT, then

  11936. **   the old.* values are rebased using the new.* values in the remote

  11937. **   change. Or, if the resolution is REPLACE, then the change is copied

  11938. **   into the rebased changeset with updates to columns also updated by

  11939. **   the conflicting remote UPDATE removed. If this means no columns would 

  11940. **   be updated, the change is omitted.

  11941. ** </dl>

  11942. **

  11943. ** A local change may be rebased against multiple remote changes 

  11944. ** simultaneously. If a single key is modified by multiple remote 

  11945. ** changesets, they are combined as follows before the local changeset

  11946. ** is rebased:

  11947. **

  11948. ** <ul>

  11949. **    <li> If there has been one or more REPLACE resolutions on a

  11950. **         key, it is rebased according to a REPLACE.

  11951. **

  11952. **    <li> If there have been no REPLACE resolutions on a key, then

  11953. **         the local changeset is rebased according to the most recent

  11954. **         of the OMIT resolutions.

  11955. ** </ul>

  11956. **

  11957. ** Note that conflict resolutions from multiple remote changesets are 

  11958. ** combined on a per-field basis, not per-row. This means that in the 

  11959. ** case of multiple remote UPDATE operations, some fields of a single 

  11960. ** local change may be rebased for REPLACE while others are rebased for 

  11961. ** OMIT.

  11962. **

  11963. ** In order to rebase a local changeset, the remote changeset must first

  11964. ** be applied to the local database using sqlite3changeset_apply_v2() and

  11965. ** the buffer of rebase information captured. Then:

  11966. **

  11967. ** <ol>

  11968. **   <li> An sqlite3_rebaser object is created by calling 

  11969. **        sqlite3rebaser_create().

  11970. **   <li> The new object is configured with the rebase buffer obtained from

  11971. **        sqlite3changeset_apply_v2() by calling sqlite3rebaser_configure().

  11972. **        If the local changeset is to be rebased against multiple remote

  11973. **        changesets, then sqlite3rebaser_configure() should be called

  11974. **        multiple times, in the same order that the multiple

  11975. **        sqlite3changeset_apply_v2() calls were made.

  11976. **   <li> Each local changeset is rebased by calling sqlite3rebaser_rebase().

  11977. **   <li> The sqlite3_rebaser object is deleted by calling

  11978. **        sqlite3rebaser_delete().

  11979. ** </ol>

  11980. */

  11981. typedef struct sqlite3_rebaser sqlite3_rebaser;

  11982. 

  11983. /*

  11984. ** CAPI3REF: Create a changeset rebaser object.

  11985. ** EXPERIMENTAL

  11986. **

  11987. ** Allocate a new changeset rebaser object. If successful, set (*ppNew) to

  11988. ** point to the new object and return SQLITE_OK. Otherwise, if an error

  11989. ** occurs, return an SQLite error code (e.g. SQLITE_NOMEM) and set (*ppNew) 

  11990. ** to NULL. 

  11991. */

  11992. SQLITE_API int sqlite3rebaser_create(sqlite3_rebaser **ppNew);

  11993. 

  11994. /*

  11995. ** CAPI3REF: Configure a changeset rebaser object.

  11996. ** EXPERIMENTAL

  11997. **

  11998. ** Configure the changeset rebaser object to rebase changesets according

  11999. ** to the conflict resolutions described by buffer pRebase (size nRebase

  12000. ** bytes), which must have been obtained from a previous call to

  12001. ** sqlite3changeset_apply_v2().

  12002. */

  12003. SQLITE_API int sqlite3rebaser_configure(

  12004.   sqlite3_rebaser*, 

  12005.   int nRebase, const void *pRebase

  12006. ); 

  12007. 

  12008. /*

  12009. ** CAPI3REF: Rebase a changeset

  12010. ** EXPERIMENTAL

  12011. **

  12012. ** Argument pIn must point to a buffer containing a changeset nIn bytes

  12013. ** in size. This function allocates and populates a buffer with a copy

  12014. ** of the changeset rebased rebased according to the configuration of the

  12015. ** rebaser object passed as the first argument. If successful, (*ppOut)

  12016. ** is set to point to the new buffer containing the rebased changeset and 

  12017. ** (*pnOut) to its size in bytes and SQLITE_OK returned. It is the

  12018. ** responsibility of the caller to eventually free the new buffer using

  12019. ** sqlite3_free(). Otherwise, if an error occurs, (*ppOut) and (*pnOut)

  12020. ** are set to zero and an SQLite error code returned.

  12021. */

  12022. SQLITE_API int sqlite3rebaser_rebase(

  12023.   sqlite3_rebaser*,

  12024.   int nIn, const void *pIn, 

  12025.   int *pnOut, void **ppOut 

  12026. );

  12027. 

  12028. /*

  12029. ** CAPI3REF: Delete a changeset rebaser object.

  12030. ** EXPERIMENTAL

  12031. **

  12032. ** Delete the changeset rebaser object and all associated resources. There

  12033. ** should be one call to this function for each successful invocation

  12034. ** of sqlite3rebaser_create().

  12035. */

  12036. SQLITE_API void sqlite3rebaser_delete(sqlite3_rebaser *p); 

  12037. 

  12038. /*

  12039. ** CAPI3REF: Streaming Versions of API functions.

  12040. **

  12041. ** The six streaming API xxx_strm() functions serve similar purposes to the 

  12042. ** corresponding non-streaming API functions:

  12043. **

  12044. ** <table border=1 style="margin-left:8ex;margin-right:8ex">

  12045. **   <tr><th>Streaming function<th>Non-streaming equivalent</th>

  12046. **   <tr><td>sqlite3changeset_apply_strm<td>[sqlite3changeset_apply] 

  12047. **   <tr><td>sqlite3changeset_apply_strm_v2<td>[sqlite3changeset_apply_v2] 

  12048. **   <tr><td>sqlite3changeset_concat_strm<td>[sqlite3changeset_concat] 

  12049. **   <tr><td>sqlite3changeset_invert_strm<td>[sqlite3changeset_invert] 

  12050. **   <tr><td>sqlite3changeset_start_strm<td>[sqlite3changeset_start] 

  12051. **   <tr><td>sqlite3session_changeset_strm<td>[sqlite3session_changeset] 

  12052. **   <tr><td>sqlite3session_patchset_strm<td>[sqlite3session_patchset] 

  12053. ** </table>

  12054. **

  12055. ** Non-streaming functions that accept changesets (or patchsets) as input

  12056. ** require that the entire changeset be stored in a single buffer in memory. 

  12057. ** Similarly, those that return a changeset or patchset do so by returning 

  12058. ** a pointer to a single large buffer allocated using sqlite3_malloc(). 

  12059. ** Normally this is convenient. However, if an application running in a 

  12060. ** low-memory environment is required to handle very large changesets, the

  12061. ** large contiguous memory allocations required can become onerous.

  12062. **

  12063. ** In order to avoid this problem, instead of a single large buffer, input

  12064. ** is passed to a streaming API functions by way of a callback function that

  12065. ** the sessions module invokes to incrementally request input data as it is

  12066. ** required. In all cases, a pair of API function parameters such as

  12067. **

  12068. **  <pre>

  12069. **  &nbsp;     int nChangeset,

  12070. **  &nbsp;     void *pChangeset,

  12071. **  </pre>

  12072. **

  12073. ** Is replaced by:

  12074. **

  12075. **  <pre>

  12076. **  &nbsp;     int (*xInput)(void *pIn, void *pData, int *pnData),

  12077. **  &nbsp;     void *pIn,

  12078. **  </pre>

  12079. **

  12080. ** Each time the xInput callback is invoked by the sessions module, the first

  12081. ** argument passed is a copy of the supplied pIn context pointer. The second 

  12082. ** argument, pData, points to a buffer (*pnData) bytes in size. Assuming no 

  12083. ** error occurs the xInput method should copy up to (*pnData) bytes of data 

  12084. ** into the buffer and set (*pnData) to the actual number of bytes copied 

  12085. ** before returning SQLITE_OK. If the input is completely exhausted, (*pnData) 

  12086. ** should be set to zero to indicate this. Or, if an error occurs, an SQLite 

  12087. ** error code should be returned. In all cases, if an xInput callback returns

  12088. ** an error, all processing is abandoned and the streaming API function

  12089. ** returns a copy of the error code to the caller.

  12090. **

  12091. ** In the case of sqlite3changeset_start_strm(), the xInput callback may be

  12092. ** invoked by the sessions module at any point during the lifetime of the

  12093. ** iterator. If such an xInput callback returns an error, the iterator enters

  12094. ** an error state, whereby all subsequent calls to iterator functions 

  12095. ** immediately fail with the same error code as returned by xInput.

  12096. **

  12097. ** Similarly, streaming API functions that return changesets (or patchsets)

  12098. ** return them in chunks by way of a callback function instead of via a

  12099. ** pointer to a single large buffer. In this case, a pair of parameters such

  12100. ** as:

  12101. **

  12102. **  <pre>

  12103. **  &nbsp;     int *pnChangeset,

  12104. **  &nbsp;     void **ppChangeset,

  12105. **  </pre>

  12106. **

  12107. ** Is replaced by:

  12108. **

  12109. **  <pre>

  12110. **  &nbsp;     int (*xOutput)(void *pOut, const void *pData, int nData),

  12111. **  &nbsp;     void *pOut

  12112. **  </pre>

  12113. **

  12114. ** The xOutput callback is invoked zero or more times to return data to

  12115. ** the application. The first parameter passed to each call is a copy of the

  12116. ** pOut pointer supplied by the application. The second parameter, pData,

  12117. ** points to a buffer nData bytes in size containing the chunk of output

  12118. ** data being returned. If the xOutput callback successfully processes the

  12119. ** supplied data, it should return SQLITE_OK to indicate success. Otherwise,

  12120. ** it should return some other SQLite error code. In this case processing

  12121. ** is immediately abandoned and the streaming API function returns a copy

  12122. ** of the xOutput error code to the application.

  12123. **

  12124. ** The sessions module never invokes an xOutput callback with the third 

  12125. ** parameter set to a value less than or equal to zero. Other than this,

  12126. ** no guarantees are made as to the size of the chunks of data returned.

  12127. */

  12128. SQLITE_API int sqlite3changeset_apply_strm(

  12129.   sqlite3 *db,                    /* Apply change to "main" db of this handle */

  12130.   int (*xInput)(void *pIn, void *pData, int *pnData), /* Input function */

  12131.   void *pIn,                                          /* First arg for xInput */

  12132.   int(*xFilter)(

  12133.     void *pCtx,                   /* Copy of sixth arg to _apply() */

  12134.     const char *zTab              /* Table name */

  12135.   ),

  12136.   int(*xConflict)(

  12137.     void *pCtx,                   /* Copy of sixth arg to _apply() */

  12138.     int eConflict,                /* DATA, MISSING, CONFLICT, CONSTRAINT */

  12139.     sqlite3_changeset_iter *p     /* Handle describing change and conflict */

  12140.   ),

  12141.   void *pCtx                      /* First argument passed to xConflict */

  12142. );

  12143. SQLITE_API int sqlite3changeset_apply_v2_strm(

  12144.   sqlite3 *db,                    /* Apply change to "main" db of this handle */

  12145.   int (*xInput)(void *pIn, void *pData, int *pnData), /* Input function */

  12146.   void *pIn,                                          /* First arg for xInput */

  12147.   int(*xFilter)(

  12148.     void *pCtx,                   /* Copy of sixth arg to _apply() */

  12149.     const char *zTab              /* Table name */

  12150.   ),

  12151.   int(*xConflict)(

  12152.     void *pCtx,                   /* Copy of sixth arg to _apply() */

  12153.     int eConflict,                /* DATA, MISSING, CONFLICT, CONSTRAINT */

  12154.     sqlite3_changeset_iter *p     /* Handle describing change and conflict */

  12155.   ),

  12156.   void *pCtx,                     /* First argument passed to xConflict */

  12157.   void **ppRebase, int *pnRebase,

  12158.   int flags

  12159. );

  12160. SQLITE_API int sqlite3changeset_concat_strm(

  12161.   int (*xInputA)(void *pIn, void *pData, int *pnData),

  12162.   void *pInA,

  12163.   int (*xInputB)(void *pIn, void *pData, int *pnData),

  12164.   void *pInB,

  12165.   int (*xOutput)(void *pOut, const void *pData, int nData),

  12166.   void *pOut

  12167. );

  12168. SQLITE_API int sqlite3changeset_invert_strm(

  12169.   int (*xInput)(void *pIn, void *pData, int *pnData),

  12170.   void *pIn,

  12171.   int (*xOutput)(void *pOut, const void *pData, int nData),

  12172.   void *pOut

  12173. );

  12174. SQLITE_API int sqlite3changeset_start_strm(

  12175.   sqlite3_changeset_iter **pp,

  12176.   int (*xInput)(void *pIn, void *pData, int *pnData),

  12177.   void *pIn

  12178. );

  12179. SQLITE_API int sqlite3changeset_start_v2_strm(

  12180.   sqlite3_changeset_iter **pp,

  12181.   int (*xInput)(void *pIn, void *pData, int *pnData),

  12182.   void *pIn,

  12183.   int flags

  12184. );

  12185. SQLITE_API int sqlite3session_changeset_strm(

  12186.   sqlite3_session *pSession,

  12187.   int (*xOutput)(void *pOut, const void *pData, int nData),

  12188.   void *pOut

  12189. );

  12190. SQLITE_API int sqlite3session_patchset_strm(

  12191.   sqlite3_session *pSession,

  12192.   int (*xOutput)(void *pOut, const void *pData, int nData),

  12193.   void *pOut

  12194. );

  12195. SQLITE_API int sqlite3changegroup_add_strm(sqlite3_changegroup*, 

  12196.     int (*xInput)(void *pIn, void *pData, int *pnData),

  12197.     void *pIn

  12198. );

  12199. SQLITE_API int sqlite3changegroup_output_strm(sqlite3_changegroup*,

  12200.     int (*xOutput)(void *pOut, const void *pData, int nData), 

  12201.     void *pOut

  12202. );

  12203. SQLITE_API int sqlite3rebaser_rebase_strm(

  12204.   sqlite3_rebaser *pRebaser,

  12205.   int (*xInput)(void *pIn, void *pData, int *pnData),

  12206.   void *pIn,

  12207.   int (*xOutput)(void *pOut, const void *pData, int nData),

  12208.   void *pOut

  12209. );

  12210. 

  12211. /*

  12212. ** CAPI3REF: Configure global parameters

  12213. **

  12214. ** The sqlite3session_config() interface is used to make global configuration

  12215. ** changes to the sessions module in order to tune it to the specific needs 

  12216. ** of the application.

  12217. **

  12218. ** The sqlite3session_config() interface is not threadsafe. If it is invoked

  12219. ** while any other thread is inside any other sessions method then the

  12220. ** results are undefined. Furthermore, if it is invoked after any sessions

  12221. ** related objects have been created, the results are also undefined. 

  12222. **

  12223. ** The first argument to the sqlite3session_config() function must be one

  12224. ** of the SQLITE_SESSION_CONFIG_XXX constants defined below. The 

  12225. ** interpretation of the (void*) value passed as the second parameter and

  12226. ** the effect of calling this function depends on the value of the first

  12227. ** parameter.

  12228. **

  12229. ** <dl>

  12230. ** <dt>SQLITE_SESSION_CONFIG_STRMSIZE<dd>

  12231. **    By default, the sessions module streaming interfaces attempt to input

  12232. **    and output data in approximately 1 KiB chunks. This operand may be used

  12233. **    to set and query the value of this configuration setting. The pointer

  12234. **    passed as the second argument must point to a value of type (int).

  12235. **    If this value is greater than 0, it is used as the new streaming data

  12236. **    chunk size for both input and output. Before returning, the (int) value

  12237. **    pointed to by pArg is set to the final value of the streaming interface

  12238. **    chunk size.

  12239. ** </dl>

  12240. **

  12241. ** This function returns SQLITE_OK if successful, or an SQLite error code

  12242. ** otherwise.

  12243. */

  12244. SQLITE_API int sqlite3session_config(int op, void *pArg);

  12245. 

  12246. /*

  12247. ** CAPI3REF: Values for sqlite3session_config().

  12248. */

  12249. #define SQLITE_SESSION_CONFIG_STRMSIZE 1

  12250. 

  12251. /*

  12252. ** Make sure we can call this stuff from C++.

  12253. */

  12254. #if 0

  12255. }

  12256. #endif

  12257. 

  12258. #endif  /* !defined(__SQLITESESSION_H_) && defined(SQLITE_ENABLE_SESSION) */

  12259. 

  12260. /******** End of sqlite3session.h *********/

  12261. /******** Begin file fts5.h *********/

  12262. /*

  12263. ** 2014 May 31

  12264. **

  12265. ** The author disclaims copyright to this source code.  In place of

  12266. ** a legal notice, here is a blessing:

  12267. **

  12268. **    May you do good and not evil.

  12269. **    May you find forgiveness for yourself and forgive others.

  12270. **    May you share freely, never taking more than you give.

  12271. **

  12272. ******************************************************************************

  12273. **

  12274. ** Interfaces to extend FTS5. Using the interfaces defined in this file, 

  12275. ** FTS5 may be extended with:

  12276. **

  12277. **     * custom tokenizers, and

  12278. **     * custom auxiliary functions.

  12279. */

  12280. 

  12281. 

  12282. #ifndef _FTS5_H

  12283. #define _FTS5_H

  12284. 

  12285. 

  12286. #if 0

  12287. extern "C" {

  12288. #endif

  12289. 

  12290. /*************************************************************************

  12291. ** CUSTOM AUXILIARY FUNCTIONS

  12292. **

  12293. ** Virtual table implementations may overload SQL functions by implementing

  12294. ** the sqlite3_module.xFindFunction() method.

  12295. */

  12296. 

  12297. typedef struct Fts5ExtensionApi Fts5ExtensionApi;

  12298. typedef struct Fts5Context Fts5Context;

  12299. typedef struct Fts5PhraseIter Fts5PhraseIter;

  12300. 

  12301. typedef void (*fts5_extension_function)(

  12302.   const Fts5ExtensionApi *pApi,   /* API offered by current FTS version */

  12303.   Fts5Context *pFts,              /* First arg to pass to pApi functions */

  12304.   sqlite3_context *pCtx,          /* Context for returning result/error */

  12305.   int nVal,                       /* Number of values in apVal[] array */

  12306.   sqlite3_value **apVal           /* Array of trailing arguments */

  12307. );

  12308. 

  12309. struct Fts5PhraseIter {

  12310.   const unsigned char *a;

  12311.   const unsigned char *b;

  12312. };

  12313. 

  12314. /*

  12315. ** EXTENSION API FUNCTIONS

  12316. **

  12317. ** xUserData(pFts):

  12318. **   Return a copy of the context pointer the extension function was 

  12319. **   registered with.

  12320. **

  12321. ** xColumnTotalSize(pFts, iCol, pnToken):

  12322. **   If parameter iCol is less than zero, set output variable *pnToken

  12323. **   to the total number of tokens in the FTS5 table. Or, if iCol is

  12324. **   non-negative but less than the number of columns in the table, return

  12325. **   the total number of tokens in column iCol, considering all rows in 

  12326. **   the FTS5 table.

  12327. **

  12328. **   If parameter iCol is greater than or equal to the number of columns

  12329. **   in the table, SQLITE_RANGE is returned. Or, if an error occurs (e.g.

  12330. **   an OOM condition or IO error), an appropriate SQLite error code is 

  12331. **   returned.

  12332. **

  12333. ** xColumnCount(pFts):

  12334. **   Return the number of columns in the table.

  12335. **

  12336. ** xColumnSize(pFts, iCol, pnToken):

  12337. **   If parameter iCol is less than zero, set output variable *pnToken

  12338. **   to the total number of tokens in the current row. Or, if iCol is

  12339. **   non-negative but less than the number of columns in the table, set

  12340. **   *pnToken to the number of tokens in column iCol of the current row.

  12341. **

  12342. **   If parameter iCol is greater than or equal to the number of columns

  12343. **   in the table, SQLITE_RANGE is returned. Or, if an error occurs (e.g.

  12344. **   an OOM condition or IO error), an appropriate SQLite error code is 

  12345. **   returned.

  12346. **

  12347. **   This function may be quite inefficient if used with an FTS5 table

  12348. **   created with the "columnsize=0" option.

  12349. **

  12350. ** xColumnText:

  12351. **   This function attempts to retrieve the text of column iCol of the

  12352. **   current document. If successful, (*pz) is set to point to a buffer

  12353. **   containing the text in utf-8 encoding, (*pn) is set to the size in bytes

  12354. **   (not characters) of the buffer and SQLITE_OK is returned. Otherwise,

  12355. **   if an error occurs, an SQLite error code is returned and the final values

  12356. **   of (*pz) and (*pn) are undefined.

  12357. **

  12358. ** xPhraseCount:

  12359. **   Returns the number of phrases in the current query expression.

  12360. **

  12361. ** xPhraseSize:

  12362. **   Returns the number of tokens in phrase iPhrase of the query. Phrases

  12363. **   are numbered starting from zero.

  12364. **

  12365. ** xInstCount:

  12366. **   Set *pnInst to the total number of occurrences of all phrases within

  12367. **   the query within the current row. Return SQLITE_OK if successful, or

  12368. **   an error code (i.e. SQLITE_NOMEM) if an error occurs.

  12369. **

  12370. **   This API can be quite slow if used with an FTS5 table created with the

  12371. **   "detail=none" or "detail=column" option. If the FTS5 table is created 

  12372. **   with either "detail=none" or "detail=column" and "content=" option 

  12373. **   (i.e. if it is a contentless table), then this API always returns 0.

  12374. **

  12375. ** xInst:

  12376. **   Query for the details of phrase match iIdx within the current row.

  12377. **   Phrase matches are numbered starting from zero, so the iIdx argument

  12378. **   should be greater than or equal to zero and smaller than the value

  12379. **   output by xInstCount().

  12380. **

  12381. **   Usually, output parameter *piPhrase is set to the phrase number, *piCol

  12382. **   to the column in which it occurs and *piOff the token offset of the

  12383. **   first token of the phrase. Returns SQLITE_OK if successful, or an error

  12384. **   code (i.e. SQLITE_NOMEM) if an error occurs.

  12385. **

  12386. **   This API can be quite slow if used with an FTS5 table created with the

  12387. **   "detail=none" or "detail=column" option. 

  12388. **

  12389. ** xRowid:

  12390. **   Returns the rowid of the current row.

  12391. **

  12392. ** xTokenize:

  12393. **   Tokenize text using the tokenizer belonging to the FTS5 table.

  12394. **

  12395. ** xQueryPhrase(pFts5, iPhrase, pUserData, xCallback):

  12396. **   This API function is used to query the FTS table for phrase iPhrase

  12397. **   of the current query. Specifically, a query equivalent to:

  12398. **

  12399. **       ... FROM ftstable WHERE ftstable MATCH $p ORDER BY rowid

  12400. **

  12401. **   with $p set to a phrase equivalent to the phrase iPhrase of the

  12402. **   current query is executed. Any column filter that applies to

  12403. **   phrase iPhrase of the current query is included in $p. For each 

  12404. **   row visited, the callback function passed as the fourth argument 

  12405. **   is invoked. The context and API objects passed to the callback 

  12406. **   function may be used to access the properties of each matched row.

  12407. **   Invoking Api.xUserData() returns a copy of the pointer passed as 

  12408. **   the third argument to pUserData.

  12409. **

  12410. **   If the callback function returns any value other than SQLITE_OK, the

  12411. **   query is abandoned and the xQueryPhrase function returns immediately.

  12412. **   If the returned value is SQLITE_DONE, xQueryPhrase returns SQLITE_OK.

  12413. **   Otherwise, the error code is propagated upwards.

  12414. **

  12415. **   If the query runs to completion without incident, SQLITE_OK is returned.

  12416. **   Or, if some error occurs before the query completes or is aborted by

  12417. **   the callback, an SQLite error code is returned.

  12418. **

  12419. **

  12420. ** xSetAuxdata(pFts5, pAux, xDelete)

  12421. **

  12422. **   Save the pointer passed as the second argument as the extension functions 

  12423. **   "auxiliary data". The pointer may then be retrieved by the current or any

  12424. **   future invocation of the same fts5 extension function made as part of

  12425. **   the same MATCH query using the xGetAuxdata() API.

  12426. **

  12427. **   Each extension function is allocated a single auxiliary data slot for

  12428. **   each FTS query (MATCH expression). If the extension function is invoked 

  12429. **   more than once for a single FTS query, then all invocations share a 

  12430. **   single auxiliary data context.

  12431. **

  12432. **   If there is already an auxiliary data pointer when this function is

  12433. **   invoked, then it is replaced by the new pointer. If an xDelete callback

  12434. **   was specified along with the original pointer, it is invoked at this

  12435. **   point.

  12436. **

  12437. **   The xDelete callback, if one is specified, is also invoked on the

  12438. **   auxiliary data pointer after the FTS5 query has finished.

  12439. **

  12440. **   If an error (e.g. an OOM condition) occurs within this function,

  12441. **   the auxiliary data is set to NULL and an error code returned. If the

  12442. **   xDelete parameter was not NULL, it is invoked on the auxiliary data

  12443. **   pointer before returning.

  12444. **

  12445. **

  12446. ** xGetAuxdata(pFts5, bClear)

  12447. **

  12448. **   Returns the current auxiliary data pointer for the fts5 extension 

  12449. **   function. See the xSetAuxdata() method for details.

  12450. **

  12451. **   If the bClear argument is non-zero, then the auxiliary data is cleared

  12452. **   (set to NULL) before this function returns. In this case the xDelete,

  12453. **   if any, is not invoked.

  12454. **

  12455. **

  12456. ** xRowCount(pFts5, pnRow)

  12457. **

  12458. **   This function is used to retrieve the total number of rows in the table.

  12459. **   In other words, the same value that would be returned by:

  12460. **

  12461. **        SELECT count(*) FROM ftstable;

  12462. **

  12463. ** xPhraseFirst()

  12464. **   This function is used, along with type Fts5PhraseIter and the xPhraseNext

  12465. **   method, to iterate through all instances of a single query phrase within

  12466. **   the current row. This is the same information as is accessible via the

  12467. **   xInstCount/xInst APIs. While the xInstCount/xInst APIs are more convenient

  12468. **   to use, this API may be faster under some circumstances. To iterate 

  12469. **   through instances of phrase iPhrase, use the following code:

  12470. **

  12471. **       Fts5PhraseIter iter;

  12472. **       int iCol, iOff;

  12473. **       for(pApi->xPhraseFirst(pFts, iPhrase, &iter, &iCol, &iOff);

  12474. **           iCol>=0;

  12475. **           pApi->xPhraseNext(pFts, &iter, &iCol, &iOff)

  12476. **       ){

  12477. **         // An instance of phrase iPhrase at offset iOff of column iCol

  12478. **       }

  12479. **

  12480. **   The Fts5PhraseIter structure is defined above. Applications should not

  12481. **   modify this structure directly - it should only be used as shown above

  12482. **   with the xPhraseFirst() and xPhraseNext() API methods (and by

  12483. **   xPhraseFirstColumn() and xPhraseNextColumn() as illustrated below).

  12484. **

  12485. **   This API can be quite slow if used with an FTS5 table created with the

  12486. **   "detail=none" or "detail=column" option. If the FTS5 table is created 

  12487. **   with either "detail=none" or "detail=column" and "content=" option 

  12488. **   (i.e. if it is a contentless table), then this API always iterates

  12489. **   through an empty set (all calls to xPhraseFirst() set iCol to -1).

  12490. **

  12491. ** xPhraseNext()

  12492. **   See xPhraseFirst above.

  12493. **

  12494. ** xPhraseFirstColumn()

  12495. **   This function and xPhraseNextColumn() are similar to the xPhraseFirst()

  12496. **   and xPhraseNext() APIs described above. The difference is that instead

  12497. **   of iterating through all instances of a phrase in the current row, these

  12498. **   APIs are used to iterate through the set of columns in the current row

  12499. **   that contain one or more instances of a specified phrase. For example:

  12500. **

  12501. **       Fts5PhraseIter iter;

  12502. **       int iCol;

  12503. **       for(pApi->xPhraseFirstColumn(pFts, iPhrase, &iter, &iCol);

  12504. **           iCol>=0;

  12505. **           pApi->xPhraseNextColumn(pFts, &iter, &iCol)

  12506. **       ){

  12507. **         // Column iCol contains at least one instance of phrase iPhrase

  12508. **       }

  12509. **

  12510. **   This API can be quite slow if used with an FTS5 table created with the

  12511. **   "detail=none" option. If the FTS5 table is created with either 

  12512. **   "detail=none" "content=" option (i.e. if it is a contentless table), 

  12513. **   then this API always iterates through an empty set (all calls to 

  12514. **   xPhraseFirstColumn() set iCol to -1).

  12515. **

  12516. **   The information accessed using this API and its companion

  12517. **   xPhraseFirstColumn() may also be obtained using xPhraseFirst/xPhraseNext

  12518. **   (or xInst/xInstCount). The chief advantage of this API is that it is

  12519. **   significantly more efficient than those alternatives when used with

  12520. **   "detail=column" tables.  

  12521. **

  12522. ** xPhraseNextColumn()

  12523. **   See xPhraseFirstColumn above.

  12524. */

  12525. struct Fts5ExtensionApi {

  12526.   int iVersion;                   /* Currently always set to 3 */

  12527. 

  12528.   void *(*xUserData)(Fts5Context*);

  12529. 

  12530.   int (*xColumnCount)(Fts5Context*);

  12531.   int (*xRowCount)(Fts5Context*, sqlite3_int64 *pnRow);

  12532.   int (*xColumnTotalSize)(Fts5Context*, int iCol, sqlite3_int64 *pnToken);

  12533. 

  12534.   int (*xTokenize)(Fts5Context*, 

  12535.     const char *pText, int nText, /* Text to tokenize */

  12536.     void *pCtx,                   /* Context passed to xToken() */

  12537.     int (*xToken)(void*, int, const char*, int, int, int)       /* Callback */

  12538.   );

  12539. 

  12540.   int (*xPhraseCount)(Fts5Context*);

  12541.   int (*xPhraseSize)(Fts5Context*, int iPhrase);

  12542. 

  12543.   int (*xInstCount)(Fts5Context*, int *pnInst);

  12544.   int (*xInst)(Fts5Context*, int iIdx, int *piPhrase, int *piCol, int *piOff);

  12545. 

  12546.   sqlite3_int64 (*xRowid)(Fts5Context*);

  12547.   int (*xColumnText)(Fts5Context*, int iCol, const char **pz, int *pn);

  12548.   int (*xColumnSize)(Fts5Context*, int iCol, int *pnToken);

  12549. 

  12550.   int (*xQueryPhrase)(Fts5Context*, int iPhrase, void *pUserData,

  12551.     int(*)(const Fts5ExtensionApi*,Fts5Context*,void*)

  12552.   );

  12553.   int (*xSetAuxdata)(Fts5Context*, void *pAux, void(*xDelete)(void*));

  12554.   void *(*xGetAuxdata)(Fts5Context*, int bClear);

  12555. 

  12556.   int (*xPhraseFirst)(Fts5Context*, int iPhrase, Fts5PhraseIter*, int*, int*);

  12557.   void (*xPhraseNext)(Fts5Context*, Fts5PhraseIter*, int *piCol, int *piOff);

  12558. 

  12559.   int (*xPhraseFirstColumn)(Fts5Context*, int iPhrase, Fts5PhraseIter*, int*);

  12560.   void (*xPhraseNextColumn)(Fts5Context*, Fts5PhraseIter*, int *piCol);

  12561. };

  12562. 

  12563. /* 

  12564. ** CUSTOM AUXILIARY FUNCTIONS

  12565. *************************************************************************/

  12566. 

  12567. /*************************************************************************

  12568. ** CUSTOM TOKENIZERS

  12569. **

  12570. ** Applications may also register custom tokenizer types. A tokenizer 

  12571. ** is registered by providing fts5 with a populated instance of the 

  12572. ** following structure. All structure methods must be defined, setting

  12573. ** any member of the fts5_tokenizer struct to NULL leads to undefined

  12574. ** behaviour. The structure methods are expected to function as follows:

  12575. **

  12576. ** xCreate:

  12577. **   This function is used to allocate and initialize a tokenizer instance.

  12578. **   A tokenizer instance is required to actually tokenize text.

  12579. **

  12580. **   The first argument passed to this function is a copy of the (void*)

  12581. **   pointer provided by the application when the fts5_tokenizer object

  12582. **   was registered with FTS5 (the third argument to xCreateTokenizer()). 

  12583. **   The second and third arguments are an array of nul-terminated strings

  12584. **   containing the tokenizer arguments, if any, specified following the

  12585. **   tokenizer name as part of the CREATE VIRTUAL TABLE statement used

  12586. **   to create the FTS5 table.

  12587. **

  12588. **   The final argument is an output variable. If successful, (*ppOut) 

  12589. **   should be set to point to the new tokenizer handle and SQLITE_OK

  12590. **   returned. If an error occurs, some value other than SQLITE_OK should

  12591. **   be returned. In this case, fts5 assumes that the final value of *ppOut 

  12592. **   is undefined.

  12593. **

  12594. ** xDelete:

  12595. **   This function is invoked to delete a tokenizer handle previously

  12596. **   allocated using xCreate(). Fts5 guarantees that this function will

  12597. **   be invoked exactly once for each successful call to xCreate().

  12598. **

  12599. ** xTokenize:

  12600. **   This function is expected to tokenize the nText byte string indicated 

  12601. **   by argument pText. pText may or may not be nul-terminated. The first

  12602. **   argument passed to this function is a pointer to an Fts5Tokenizer object

  12603. **   returned by an earlier call to xCreate().

  12604. **

  12605. **   The second argument indicates the reason that FTS5 is requesting

  12606. **   tokenization of the supplied text. This is always one of the following

  12607. **   four values:

  12608. **

  12609. **   <ul><li> <b>FTS5_TOKENIZE_DOCUMENT</b> - A document is being inserted into

  12610. **            or removed from the FTS table. The tokenizer is being invoked to

  12611. **            determine the set of tokens to add to (or delete from) the

  12612. **            FTS index.

  12613. **

  12614. **       <li> <b>FTS5_TOKENIZE_QUERY</b> - A MATCH query is being executed 

  12615. **            against the FTS index. The tokenizer is being called to tokenize 

  12616. **            a bareword or quoted string specified as part of the query.

  12617. **

  12618. **       <li> <b>(FTS5_TOKENIZE_QUERY | FTS5_TOKENIZE_PREFIX)</b> - Same as

  12619. **            FTS5_TOKENIZE_QUERY, except that the bareword or quoted string is

  12620. **            followed by a "*" character, indicating that the last token

  12621. **            returned by the tokenizer will be treated as a token prefix.

  12622. **

  12623. **       <li> <b>FTS5_TOKENIZE_AUX</b> - The tokenizer is being invoked to 

  12624. **            satisfy an fts5_api.xTokenize() request made by an auxiliary

  12625. **            function. Or an fts5_api.xColumnSize() request made by the same

  12626. **            on a columnsize=0 database.  

  12627. **   </ul>

  12628. **

  12629. **   For each token in the input string, the supplied callback xToken() must

  12630. **   be invoked. The first argument to it should be a copy of the pointer

  12631. **   passed as the second argument to xTokenize(). The third and fourth

  12632. **   arguments are a pointer to a buffer containing the token text, and the

  12633. **   size of the token in bytes. The 4th and 5th arguments are the byte offsets

  12634. **   of the first byte of and first byte immediately following the text from

  12635. **   which the token is derived within the input.

  12636. **

  12637. **   The second argument passed to the xToken() callback ("tflags") should

  12638. **   normally be set to 0. The exception is if the tokenizer supports 

  12639. **   synonyms. In this case see the discussion below for details.

  12640. **

  12641. **   FTS5 assumes the xToken() callback is invoked for each token in the 

  12642. **   order that they occur within the input text.

  12643. **

  12644. **   If an xToken() callback returns any value other than SQLITE_OK, then

  12645. **   the tokenization should be abandoned and the xTokenize() method should

  12646. **   immediately return a copy of the xToken() return value. Or, if the

  12647. **   input buffer is exhausted, xTokenize() should return SQLITE_OK. Finally,

  12648. **   if an error occurs with the xTokenize() implementation itself, it

  12649. **   may abandon the tokenization and return any error code other than

  12650. **   SQLITE_OK or SQLITE_DONE.

  12651. **

  12652. ** SYNONYM SUPPORT

  12653. **

  12654. **   Custom tokenizers may also support synonyms. Consider a case in which a

  12655. **   user wishes to query for a phrase such as "first place". Using the 

  12656. **   built-in tokenizers, the FTS5 query 'first + place' will match instances

  12657. **   of "first place" within the document set, but not alternative forms

  12658. **   such as "1st place". In some applications, it would be better to match

  12659. **   all instances of "first place" or "1st place" regardless of which form

  12660. **   the user specified in the MATCH query text.

  12661. **

  12662. **   There are several ways to approach this in FTS5:

  12663. **

  12664. **   <ol><li> By mapping all synonyms to a single token. In this case, the 

  12665. **            In the above example, this means that the tokenizer returns the

  12666. **            same token for inputs "first" and "1st". Say that token is in

  12667. **            fact "first", so that when the user inserts the document "I won

  12668. **            1st place" entries are added to the index for tokens "i", "won",

  12669. **            "first" and "place". If the user then queries for '1st + place',

  12670. **            the tokenizer substitutes "first" for "1st" and the query works

  12671. **            as expected.

  12672. **

  12673. **       <li> By querying the index for all synonyms of each query term

  12674. **            separately. In this case, when tokenizing query text, the

  12675. **            tokenizer may provide multiple synonyms for a single term 

  12676. **            within the document. FTS5 then queries the index for each 

  12677. **            synonym individually. For example, faced with the query:

  12678. **

  12679. **   <codeblock>

  12680. **     ... MATCH 'first place'</codeblock>

  12681. **

  12682. **            the tokenizer offers both "1st" and "first" as synonyms for the

  12683. **            first token in the MATCH query and FTS5 effectively runs a query 

  12684. **            similar to:

  12685. **

  12686. **   <codeblock>

  12687. **     ... MATCH '(first OR 1st) place'</codeblock>

  12688. **

  12689. **            except that, for the purposes of auxiliary functions, the query

  12690. **            still appears to contain just two phrases - "(first OR 1st)" 

  12691. **            being treated as a single phrase.

  12692. **

  12693. **       <li> By adding multiple synonyms for a single term to the FTS index.

  12694. **            Using this method, when tokenizing document text, the tokenizer

  12695. **            provides multiple synonyms for each token. So that when a 

  12696. **            document such as "I won first place" is tokenized, entries are

  12697. **            added to the FTS index for "i", "won", "first", "1st" and

  12698. **            "place".

  12699. **

  12700. **            This way, even if the tokenizer does not provide synonyms

  12701. **            when tokenizing query text (it should not - to do so would be

  12702. **            inefficient), it doesn't matter if the user queries for 

  12703. **            'first + place' or '1st + place', as there are entries in the

  12704. **            FTS index corresponding to both forms of the first token.

  12705. **   </ol>

  12706. **

  12707. **   Whether it is parsing document or query text, any call to xToken that

  12708. **   specifies a <i>tflags</i> argument with the FTS5_TOKEN_COLOCATED bit

  12709. **   is considered to supply a synonym for the previous token. For example,

  12710. **   when parsing the document "I won first place", a tokenizer that supports

  12711. **   synonyms would call xToken() 5 times, as follows:

  12712. **

  12713. **   <codeblock>

  12714. **       xToken(pCtx, 0, "i",                      1,  0,  1);

  12715. **       xToken(pCtx, 0, "won",                    3,  2,  5);

  12716. **       xToken(pCtx, 0, "first",                  5,  6, 11);

  12717. **       xToken(pCtx, FTS5_TOKEN_COLOCATED, "1st", 3,  6, 11);

  12718. **       xToken(pCtx, 0, "place",                  5, 12, 17);

  12719. **</codeblock>

  12720. **

  12721. **   It is an error to specify the FTS5_TOKEN_COLOCATED flag the first time

  12722. **   xToken() is called. Multiple synonyms may be specified for a single token

  12723. **   by making multiple calls to xToken(FTS5_TOKEN_COLOCATED) in sequence. 

  12724. **   There is no limit to the number of synonyms that may be provided for a

  12725. **   single token.

  12726. **

  12727. **   In many cases, method (1) above is the best approach. It does not add 

  12728. **   extra data to the FTS index or require FTS5 to query for multiple terms,

  12729. **   so it is efficient in terms of disk space and query speed. However, it

  12730. **   does not support prefix queries very well. If, as suggested above, the

  12731. **   token "first" is substituted for "1st" by the tokenizer, then the query:

  12732. **

  12733. **   <codeblock>

  12734. **     ... MATCH '1s*'</codeblock>

  12735. **

  12736. **   will not match documents that contain the token "1st" (as the tokenizer

  12737. **   will probably not map "1s" to any prefix of "first").

  12738. **

  12739. **   For full prefix support, method (3) may be preferred. In this case, 

  12740. **   because the index contains entries for both "first" and "1st", prefix

  12741. **   queries such as 'fi*' or '1s*' will match correctly. However, because

  12742. **   extra entries are added to the FTS index, this method uses more space

  12743. **   within the database.

  12744. **

  12745. **   Method (2) offers a midpoint between (1) and (3). Using this method,

  12746. **   a query such as '1s*' will match documents that contain the literal 

  12747. **   token "1st", but not "first" (assuming the tokenizer is not able to

  12748. **   provide synonyms for prefixes). However, a non-prefix query like '1st'

  12749. **   will match against "1st" and "first". This method does not require

  12750. **   extra disk space, as no extra entries are added to the FTS index. 

  12751. **   On the other hand, it may require more CPU cycles to run MATCH queries,

  12752. **   as separate queries of the FTS index are required for each synonym.

  12753. **

  12754. **   When using methods (2) or (3), it is important that the tokenizer only

  12755. **   provide synonyms when tokenizing document text (method (2)) or query

  12756. **   text (method (3)), not both. Doing so will not cause any errors, but is

  12757. **   inefficient.

  12758. */

  12759. typedef struct Fts5Tokenizer Fts5Tokenizer;

  12760. typedef struct fts5_tokenizer fts5_tokenizer;

  12761. struct fts5_tokenizer {

  12762.   int (*xCreate)(void*, const char **azArg, int nArg, Fts5Tokenizer **ppOut);

  12763.   void (*xDelete)(Fts5Tokenizer*);

  12764.   int (*xTokenize)(Fts5Tokenizer*, 

  12765.       void *pCtx,

  12766.       int flags,            /* Mask of FTS5_TOKENIZE_* flags */

  12767.       const char *pText, int nText, 

  12768.       int (*xToken)(

  12769.         void *pCtx,         /* Copy of 2nd argument to xTokenize() */

  12770.         int tflags,         /* Mask of FTS5_TOKEN_* flags */

  12771.         const char *pToken, /* Pointer to buffer containing token */

  12772.         int nToken,         /* Size of token in bytes */

  12773.         int iStart,         /* Byte offset of token within input text */

  12774.         int iEnd            /* Byte offset of end of token within input text */

  12775.       )

  12776.   );

  12777. };

  12778. 

  12779. /* Flags that may be passed as the third argument to xTokenize() */

  12780. #define FTS5_TOKENIZE_QUERY     0x0001

  12781. #define FTS5_TOKENIZE_PREFIX    0x0002

  12782. #define FTS5_TOKENIZE_DOCUMENT  0x0004

  12783. #define FTS5_TOKENIZE_AUX       0x0008

  12784. 

  12785. /* Flags that may be passed by the tokenizer implementation back to FTS5

  12786. ** as the third argument to the supplied xToken callback. */

  12787. #define FTS5_TOKEN_COLOCATED    0x0001      /* Same position as prev. token */

  12788. 

  12789. /*

  12790. ** END OF CUSTOM TOKENIZERS

  12791. *************************************************************************/

  12792. 

  12793. /*************************************************************************

  12794. ** FTS5 EXTENSION REGISTRATION API

  12795. */

  12796. typedef struct fts5_api fts5_api;

  12797. struct fts5_api {

  12798.   int iVersion;                   /* Currently always set to 2 */

  12799. 

  12800.   /* Create a new tokenizer */

  12801.   int (*xCreateTokenizer)(

  12802.     fts5_api *pApi,

  12803.     const char *zName,

  12804.     void *pContext,

  12805.     fts5_tokenizer *pTokenizer,

  12806.     void (*xDestroy)(void*)

  12807.   );

  12808. 

  12809.   /* Find an existing tokenizer */

  12810.   int (*xFindTokenizer)(

  12811.     fts5_api *pApi,

  12812.     const char *zName,

  12813.     void **ppContext,

  12814.     fts5_tokenizer *pTokenizer

  12815.   );

  12816. 

  12817.   /* Create a new auxiliary function */

  12818.   int (*xCreateFunction)(

  12819.     fts5_api *pApi,

  12820.     const char *zName,

  12821.     void *pContext,

  12822.     fts5_extension_function xFunction,

  12823.     void (*xDestroy)(void*)

  12824.   );

  12825. };

  12826. 

  12827. /*

  12828. ** END OF REGISTRATION API

  12829. *************************************************************************/

  12830. 

  12831. #if 0

  12832. }  /* end of the 'extern "C"' block */

  12833. #endif

  12834. 

  12835. #endif /* _FTS5_H */

  12836. 

  12837. /******** End of fts5.h *********/

  12838. 

  12839. /************** End of sqlite3.h *********************************************/

  12840. /************** Continuing where we left off in sqliteInt.h ******************/

  12841. 

  12842. /*

  12843. ** Include the configuration header output by 'configure' if we're using the

  12844. ** autoconf-based build

  12845. */

  12846. #if defined(_HAVE_SQLITE_CONFIG_H) && !defined(SQLITECONFIG_H)

  12847. /* #include "config.h" */

  12848. #define SQLITECONFIG_H 1

  12849. #endif

  12850. 

  12851. /************** Include sqliteLimit.h in the middle of sqliteInt.h ***********/

  12852. /************** Begin file sqliteLimit.h *************************************/

  12853. /*

  12854. ** 2007 May 7

  12855. **

  12856. ** The author disclaims copyright to this source code.  In place of

  12857. ** a legal notice, here is a blessing:

  12858. **

  12859. **    May you do good and not evil.

  12860. **    May you find forgiveness for yourself and forgive others.

  12861. **    May you share freely, never taking more than you give.

  12862. **

  12863. *************************************************************************

  12864. ** 

  12865. ** This file defines various limits of what SQLite can process.

  12866. */

  12867. 

  12868. /*

  12869. ** The maximum length of a TEXT or BLOB in bytes.   This also

  12870. ** limits the size of a row in a table or index.

  12871. **

  12872. ** The hard limit is the ability of a 32-bit signed integer

  12873. ** to count the size: 2^31-1 or 2147483647.

  12874. */

  12875. #ifndef SQLITE_MAX_LENGTH

  12876. # define SQLITE_MAX_LENGTH 1000000000

  12877. #endif

  12878. 

  12879. /*

  12880. ** This is the maximum number of

  12881. **

  12882. **    * Columns in a table

  12883. **    * Columns in an index

  12884. **    * Columns in a view

  12885. **    * Terms in the SET clause of an UPDATE statement

  12886. **    * Terms in the result set of a SELECT statement

  12887. **    * Terms in the GROUP BY or ORDER BY clauses of a SELECT statement.

  12888. **    * Terms in the VALUES clause of an INSERT statement

  12889. **

  12890. ** The hard upper limit here is 32676.  Most database people will

  12891. ** tell you that in a well-normalized database, you usually should

  12892. ** not have more than a dozen or so columns in any table.  And if

  12893. ** that is the case, there is no point in having more than a few

  12894. ** dozen values in any of the other situations described above.

  12895. */

  12896. #ifndef SQLITE_MAX_COLUMN

  12897. # define SQLITE_MAX_COLUMN 2000

  12898. #endif

  12899. 

  12900. /*

  12901. ** The maximum length of a single SQL statement in bytes.

  12902. **

  12903. ** It used to be the case that setting this value to zero would

  12904. ** turn the limit off.  That is no longer true.  It is not possible

  12905. ** to turn this limit off.

  12906. */

  12907. #ifndef SQLITE_MAX_SQL_LENGTH

  12908. # define SQLITE_MAX_SQL_LENGTH 1000000000

  12909. #endif

  12910. 

  12911. /*

  12912. ** The maximum depth of an expression tree. This is limited to 

  12913. ** some extent by SQLITE_MAX_SQL_LENGTH. But sometime you might 

  12914. ** want to place more severe limits on the complexity of an 

  12915. ** expression.

  12916. **

  12917. ** A value of 0 used to mean that the limit was not enforced.

  12918. ** But that is no longer true.  The limit is now strictly enforced

  12919. ** at all times.

  12920. */

  12921. #ifndef SQLITE_MAX_EXPR_DEPTH

  12922. # define SQLITE_MAX_EXPR_DEPTH 1000

  12923. #endif

  12924. 

  12925. /*

  12926. ** The maximum number of terms in a compound SELECT statement.

  12927. ** The code generator for compound SELECT statements does one

  12928. ** level of recursion for each term.  A stack overflow can result

  12929. ** if the number of terms is too large.  In practice, most SQL

  12930. ** never has more than 3 or 4 terms.  Use a value of 0 to disable

  12931. ** any limit on the number of terms in a compount SELECT.

  12932. */

  12933. #ifndef SQLITE_MAX_COMPOUND_SELECT

  12934. # define SQLITE_MAX_COMPOUND_SELECT 500

  12935. #endif

  12936. 

  12937. /*

  12938. ** The maximum number of opcodes in a VDBE program.

  12939. ** Not currently enforced.

  12940. */

  12941. #ifndef SQLITE_MAX_VDBE_OP

  12942. # define SQLITE_MAX_VDBE_OP 250000000

  12943. #endif

  12944. 

  12945. /*

  12946. ** The maximum number of arguments to an SQL function.

  12947. */

  12948. #ifndef SQLITE_MAX_FUNCTION_ARG

  12949. # define SQLITE_MAX_FUNCTION_ARG 127

  12950. #endif

  12951. 

  12952. /*

  12953. ** The suggested maximum number of in-memory pages to use for

  12954. ** the main database table and for temporary tables.

  12955. **

  12956. ** IMPLEMENTATION-OF: R-30185-15359 The default suggested cache size is -2000,

  12957. ** which means the cache size is limited to 2048000 bytes of memory.

  12958. ** IMPLEMENTATION-OF: R-48205-43578 The default suggested cache size can be

  12959. ** altered using the SQLITE_DEFAULT_CACHE_SIZE compile-time options.

  12960. */

  12961. #ifndef SQLITE_DEFAULT_CACHE_SIZE

  12962. # define SQLITE_DEFAULT_CACHE_SIZE  -2000

  12963. #endif

  12964. 

  12965. /*

  12966. ** The default number of frames to accumulate in the log file before

  12967. ** checkpointing the database in WAL mode.

  12968. */

  12969. #ifndef SQLITE_DEFAULT_WAL_AUTOCHECKPOINT

  12970. # define SQLITE_DEFAULT_WAL_AUTOCHECKPOINT  1000

  12971. #endif

  12972. 

  12973. /*

  12974. ** The maximum number of attached databases.  This must be between 0

  12975. ** and 125.  The upper bound of 125 is because the attached databases are

  12976. ** counted using a signed 8-bit integer which has a maximum value of 127

  12977. ** and we have to allow 2 extra counts for the "main" and "temp" databases.

  12978. */

  12979. #ifndef SQLITE_MAX_ATTACHED

  12980. # define SQLITE_MAX_ATTACHED 10

  12981. #endif

  12982. 

  12983. 

  12984. /*

  12985. ** The maximum value of a ?nnn wildcard that the parser will accept.

  12986. */

  12987. #ifndef SQLITE_MAX_VARIABLE_NUMBER

  12988. # define SQLITE_MAX_VARIABLE_NUMBER 999

  12989. #endif

  12990. 

  12991. /* Maximum page size.  The upper bound on this value is 65536.  This a limit

  12992. ** imposed by the use of 16-bit offsets within each page.

  12993. **

  12994. ** Earlier versions of SQLite allowed the user to change this value at

  12995. ** compile time. This is no longer permitted, on the grounds that it creates

  12996. ** a library that is technically incompatible with an SQLite library 

  12997. ** compiled with a different limit. If a process operating on a database 

  12998. ** with a page-size of 65536 bytes crashes, then an instance of SQLite 

  12999. ** compiled with the default page-size limit will not be able to rollback 

  13000. ** the aborted transaction. This could lead to database corruption.

  13001. */

  13002. #ifdef SQLITE_MAX_PAGE_SIZE

  13003. # undef SQLITE_MAX_PAGE_SIZE

  13004. #endif

  13005. #define SQLITE_MAX_PAGE_SIZE 65536

  13006. 

  13007. 

  13008. /*

  13009. ** The default size of a database page.

  13010. */

  13011. #ifndef SQLITE_DEFAULT_PAGE_SIZE

  13012. # define SQLITE_DEFAULT_PAGE_SIZE 4096

  13013. #endif

  13014. #if SQLITE_DEFAULT_PAGE_SIZE>SQLITE_MAX_PAGE_SIZE

  13015. # undef SQLITE_DEFAULT_PAGE_SIZE

  13016. # define SQLITE_DEFAULT_PAGE_SIZE SQLITE_MAX_PAGE_SIZE

  13017. #endif

  13018. 

  13019. /*

  13020. ** Ordinarily, if no value is explicitly provided, SQLite creates databases

  13021. ** with page size SQLITE_DEFAULT_PAGE_SIZE. However, based on certain

  13022. ** device characteristics (sector-size and atomic write() support),

  13023. ** SQLite may choose a larger value. This constant is the maximum value

  13024. ** SQLite will choose on its own.

  13025. */

  13026. #ifndef SQLITE_MAX_DEFAULT_PAGE_SIZE

  13027. # define SQLITE_MAX_DEFAULT_PAGE_SIZE 8192

  13028. #endif

  13029. #if SQLITE_MAX_DEFAULT_PAGE_SIZE>SQLITE_MAX_PAGE_SIZE

  13030. # undef SQLITE_MAX_DEFAULT_PAGE_SIZE

  13031. # define SQLITE_MAX_DEFAULT_PAGE_SIZE SQLITE_MAX_PAGE_SIZE

  13032. #endif

  13033. 

  13034. 

  13035. /*

  13036. ** Maximum number of pages in one database file.

  13037. **

  13038. ** This is really just the default value for the max_page_count pragma.

  13039. ** This value can be lowered (or raised) at run-time using that the

  13040. ** max_page_count macro.

  13041. */

  13042. #ifndef SQLITE_MAX_PAGE_COUNT

  13043. # define SQLITE_MAX_PAGE_COUNT 1073741823

  13044. #endif

  13045. 

  13046. /*

  13047. ** Maximum length (in bytes) of the pattern in a LIKE or GLOB

  13048. ** operator.

  13049. */

  13050. #ifndef SQLITE_MAX_LIKE_PATTERN_LENGTH

  13051. # define SQLITE_MAX_LIKE_PATTERN_LENGTH 50000

  13052. #endif

  13053. 

  13054. /*

  13055. ** Maximum depth of recursion for triggers.

  13056. **

  13057. ** A value of 1 means that a trigger program will not be able to itself

  13058. ** fire any triggers. A value of 0 means that no trigger programs at all 

  13059. ** may be executed.

  13060. */

  13061. #ifndef SQLITE_MAX_TRIGGER_DEPTH

  13062. # define SQLITE_MAX_TRIGGER_DEPTH 1000

  13063. #endif

  13064. 

  13065. /************** End of sqliteLimit.h *****************************************/

  13066. /************** Continuing where we left off in sqliteInt.h ******************/

  13067. 

  13068. /* Disable nuisance warnings on Borland compilers */

  13069. #if defined(__BORLANDC__)

  13070. #pragma warn -rch /* unreachable code */

  13071. #pragma warn -ccc /* Condition is always true or false */

  13072. #pragma warn -aus /* Assigned value is never used */

  13073. #pragma warn -csu /* Comparing signed and unsigned */

  13074. #pragma warn -spa /* Suspicious pointer arithmetic */

  13075. #endif

  13076. 

  13077. /*

  13078. ** Include standard header files as necessary

  13079. */

  13080. #ifdef HAVE_STDINT_H

  13081. #include <stdint.h>

  13082. #endif

  13083. #ifdef HAVE_INTTYPES_H

  13084. #include <inttypes.h>

  13085. #endif

  13086. 

  13087. /*

  13088. ** The following macros are used to cast pointers to integers and

  13089. ** integers to pointers.  The way you do this varies from one compiler

  13090. ** to the next, so we have developed the following set of #if statements

  13091. ** to generate appropriate macros for a wide range of compilers.

  13092. **

  13093. ** The correct "ANSI" way to do this is to use the intptr_t type.

  13094. ** Unfortunately, that typedef is not available on all compilers, or

  13095. ** if it is available, it requires an #include of specific headers

  13096. ** that vary from one machine to the next.

  13097. **

  13098. ** Ticket #3860:  The llvm-gcc-4.2 compiler from Apple chokes on

  13099. ** the ((void*)&((char*)0)[X]) construct.  But MSVC chokes on ((void*)(X)).

  13100. ** So we have to define the macros in different ways depending on the

  13101. ** compiler.

  13102. */

  13103. #if defined(__PTRDIFF_TYPE__)  /* This case should work for GCC */

  13104. # define SQLITE_INT_TO_PTR(X)  ((void*)(__PTRDIFF_TYPE__)(X))

  13105. # define SQLITE_PTR_TO_INT(X)  ((int)(__PTRDIFF_TYPE__)(X))

  13106. #elif !defined(__GNUC__)       /* Works for compilers other than LLVM */

  13107. # define SQLITE_INT_TO_PTR(X)  ((void*)&((char*)0)[X])

  13108. # define SQLITE_PTR_TO_INT(X)  ((int)(((char*)X)-(char*)0))

  13109. #elif defined(HAVE_STDINT_H)   /* Use this case if we have ANSI headers */

  13110. # define SQLITE_INT_TO_PTR(X)  ((void*)(intptr_t)(X))

  13111. # define SQLITE_PTR_TO_INT(X)  ((int)(intptr_t)(X))

  13112. #else                          /* Generates a warning - but it always works */

  13113. # define SQLITE_INT_TO_PTR(X)  ((void*)(X))

  13114. # define SQLITE_PTR_TO_INT(X)  ((int)(X))

  13115. #endif

  13116. 

  13117. /*

  13118. ** A macro to hint to the compiler that a function should not be

  13119. ** inlined.

  13120. */

  13121. #if defined(__GNUC__)

  13122. #  define SQLITE_NOINLINE  __attribute__((noinline))

  13123. #elif defined(_MSC_VER) && _MSC_VER>=1310

  13124. #  define SQLITE_NOINLINE  __declspec(noinline)

  13125. #else

  13126. #  define SQLITE_NOINLINE

  13127. #endif

  13128. 

  13129. /*

  13130. ** Make sure that the compiler intrinsics we desire are enabled when

  13131. ** compiling with an appropriate version of MSVC unless prevented by

  13132. ** the SQLITE_DISABLE_INTRINSIC define.

  13133. */

  13134. #if !defined(SQLITE_DISABLE_INTRINSIC)

  13135. #  if defined(_MSC_VER) && _MSC_VER>=1400

  13136. #    if !defined(_WIN32_WCE)

  13137. #      include <intrin.h>

  13138. #      pragma intrinsic(_byteswap_ushort)

  13139. #      pragma intrinsic(_byteswap_ulong)

  13140. #      pragma intrinsic(_byteswap_uint64)

  13141. #      pragma intrinsic(_ReadWriteBarrier)

  13142. #    else

  13143. #      include <cmnintrin.h>

  13144. #    endif

  13145. #  endif

  13146. #endif

  13147. 

  13148. /*

  13149. ** The SQLITE_THREADSAFE macro must be defined as 0, 1, or 2.

  13150. ** 0 means mutexes are permanently disable and the library is never

  13151. ** threadsafe.  1 means the library is serialized which is the highest

  13152. ** level of threadsafety.  2 means the library is multithreaded - multiple

  13153. ** threads can use SQLite as long as no two threads try to use the same

  13154. ** database connection at the same time.

  13155. **

  13156. ** Older versions of SQLite used an optional THREADSAFE macro.

  13157. ** We support that for legacy.

  13158. **

  13159. ** To ensure that the correct value of "THREADSAFE" is reported when querying

  13160. ** for compile-time options at runtime (e.g. "PRAGMA compile_options"), this

  13161. ** logic is partially replicated in ctime.c. If it is updated here, it should

  13162. ** also be updated there.

  13163. */

  13164. #if !defined(SQLITE_THREADSAFE)

  13165. # if defined(THREADSAFE)

  13166. #   define SQLITE_THREADSAFE THREADSAFE

  13167. # else

  13168. #   define SQLITE_THREADSAFE 1 /* IMP: R-07272-22309 */

  13169. # endif

  13170. #endif

  13171. 

  13172. /*

  13173. ** Powersafe overwrite is on by default.  But can be turned off using

  13174. ** the -DSQLITE_POWERSAFE_OVERWRITE=0 command-line option.

  13175. */

  13176. #ifndef SQLITE_POWERSAFE_OVERWRITE

  13177. # define SQLITE_POWERSAFE_OVERWRITE 1

  13178. #endif

  13179. 

  13180. /*

  13181. ** EVIDENCE-OF: R-25715-37072 Memory allocation statistics are enabled by

  13182. ** default unless SQLite is compiled with SQLITE_DEFAULT_MEMSTATUS=0 in

  13183. ** which case memory allocation statistics are disabled by default.

  13184. */

  13185. #if !defined(SQLITE_DEFAULT_MEMSTATUS)

  13186. # define SQLITE_DEFAULT_MEMSTATUS 1

  13187. #endif

  13188. 

  13189. /*

  13190. ** Exactly one of the following macros must be defined in order to

  13191. ** specify which memory allocation subsystem to use.

  13192. **

  13193. **     SQLITE_SYSTEM_MALLOC          // Use normal system malloc()

  13194. **     SQLITE_WIN32_MALLOC           // Use Win32 native heap API

  13195. **     SQLITE_ZERO_MALLOC            // Use a stub allocator that always fails

  13196. **     SQLITE_MEMDEBUG               // Debugging version of system malloc()

  13197. **

  13198. ** On Windows, if the SQLITE_WIN32_MALLOC_VALIDATE macro is defined and the

  13199. ** assert() macro is enabled, each call into the Win32 native heap subsystem

  13200. ** will cause HeapValidate to be called.  If heap validation should fail, an

  13201. ** assertion will be triggered.

  13202. **

  13203. ** If none of the above are defined, then set SQLITE_SYSTEM_MALLOC as

  13204. ** the default.

  13205. */

  13206. #if defined(SQLITE_SYSTEM_MALLOC) \

  13207.   + defined(SQLITE_WIN32_MALLOC) \

  13208.   + defined(SQLITE_ZERO_MALLOC) \

  13209.   + defined(SQLITE_MEMDEBUG)>1

  13210. # error "Two or more of the following compile-time configuration options\

  13211.  are defined but at most one is allowed:\

  13212.  SQLITE_SYSTEM_MALLOC, SQLITE_WIN32_MALLOC, SQLITE_MEMDEBUG,\

  13213.  SQLITE_ZERO_MALLOC"

  13214. #endif

  13215. #if defined(SQLITE_SYSTEM_MALLOC) \

  13216.   + defined(SQLITE_WIN32_MALLOC) \

  13217.   + defined(SQLITE_ZERO_MALLOC) \

  13218.   + defined(SQLITE_MEMDEBUG)==0

  13219. # define SQLITE_SYSTEM_MALLOC 1

  13220. #endif

  13221. 

  13222. /*

  13223. ** If SQLITE_MALLOC_SOFT_LIMIT is not zero, then try to keep the

  13224. ** sizes of memory allocations below this value where possible.

  13225. */

  13226. #if !defined(SQLITE_MALLOC_SOFT_LIMIT)

  13227. # define SQLITE_MALLOC_SOFT_LIMIT 1024

  13228. #endif

  13229. 

  13230. /*

  13231. ** We need to define _XOPEN_SOURCE as follows in order to enable

  13232. ** recursive mutexes on most Unix systems and fchmod() on OpenBSD.

  13233. ** But _XOPEN_SOURCE define causes problems for Mac OS X, so omit

  13234. ** it.

  13235. */

  13236. #if !defined(_XOPEN_SOURCE) && !defined(__DARWIN__) && !defined(__APPLE__)

  13237. #  define _XOPEN_SOURCE 600

  13238. #endif

  13239. 

  13240. /*

  13241. ** NDEBUG and SQLITE_DEBUG are opposites.  It should always be true that

  13242. ** defined(NDEBUG)==!defined(SQLITE_DEBUG).  If this is not currently true,

  13243. ** make it true by defining or undefining NDEBUG.

  13244. **

  13245. ** Setting NDEBUG makes the code smaller and faster by disabling the

  13246. ** assert() statements in the code.  So we want the default action

  13247. ** to be for NDEBUG to be set and NDEBUG to be undefined only if SQLITE_DEBUG

  13248. ** is set.  Thus NDEBUG becomes an opt-in rather than an opt-out

  13249. ** feature.

  13250. */

  13251. #if !defined(NDEBUG) && !defined(SQLITE_DEBUG)

  13252. # define NDEBUG 1

  13253. #endif

  13254. #if defined(NDEBUG) && defined(SQLITE_DEBUG)

  13255. # undef NDEBUG

  13256. #endif

  13257. 

  13258. /*

  13259. ** Enable SQLITE_ENABLE_EXPLAIN_COMMENTS if SQLITE_DEBUG is turned on.

  13260. */

  13261. #if !defined(SQLITE_ENABLE_EXPLAIN_COMMENTS) && defined(SQLITE_DEBUG)

  13262. # define SQLITE_ENABLE_EXPLAIN_COMMENTS 1

  13263. #endif

  13264. 

  13265. /*

  13266. ** The testcase() macro is used to aid in coverage testing.  When

  13267. ** doing coverage testing, the condition inside the argument to

  13268. ** testcase() must be evaluated both true and false in order to

  13269. ** get full branch coverage.  The testcase() macro is inserted

  13270. ** to help ensure adequate test coverage in places where simple

  13271. ** condition/decision coverage is inadequate.  For example, testcase()

  13272. ** can be used to make sure boundary values are tested.  For

  13273. ** bitmask tests, testcase() can be used to make sure each bit

  13274. ** is significant and used at least once.  On switch statements

  13275. ** where multiple cases go to the same block of code, testcase()

  13276. ** can insure that all cases are evaluated.

  13277. **

  13278. */

  13279. #ifdef SQLITE_COVERAGE_TEST

  13280. SQLITE_PRIVATE   void sqlite3Coverage(int);

  13281. # define testcase(X)  if( X ){ sqlite3Coverage(__LINE__); }

  13282. #else

  13283. # define testcase(X)

  13284. #endif

  13285. 

  13286. /*

  13287. ** The TESTONLY macro is used to enclose variable declarations or

  13288. ** other bits of code that are needed to support the arguments

  13289. ** within testcase() and assert() macros.

  13290. */

  13291. #if !defined(NDEBUG) || defined(SQLITE_COVERAGE_TEST)

  13292. # define TESTONLY(X)  X

  13293. #else

  13294. # define TESTONLY(X)

  13295. #endif

  13296. 

  13297. /*

  13298. ** Sometimes we need a small amount of code such as a variable initialization

  13299. ** to setup for a later assert() statement.  We do not want this code to

  13300. ** appear when assert() is disabled.  The following macro is therefore

  13301. ** used to contain that setup code.  The "VVA" acronym stands for

  13302. ** "Verification, Validation, and Accreditation".  In other words, the

  13303. ** code within VVA_ONLY() will only run during verification processes.

  13304. */

  13305. #ifndef NDEBUG

  13306. # define VVA_ONLY(X)  X

  13307. #else

  13308. # define VVA_ONLY(X)

  13309. #endif

  13310. 

  13311. /*

  13312. ** The ALWAYS and NEVER macros surround boolean expressions which

  13313. ** are intended to always be true or false, respectively.  Such

  13314. ** expressions could be omitted from the code completely.  But they

  13315. ** are included in a few cases in order to enhance the resilience

  13316. ** of SQLite to unexpected behavior - to make the code "self-healing"

  13317. ** or "ductile" rather than being "brittle" and crashing at the first

  13318. ** hint of unplanned behavior.

  13319. **

  13320. ** In other words, ALWAYS and NEVER are added for defensive code.

  13321. **

  13322. ** When doing coverage testing ALWAYS and NEVER are hard-coded to

  13323. ** be true and false so that the unreachable code they specify will

  13324. ** not be counted as untested code.

  13325. */

  13326. #if defined(SQLITE_COVERAGE_TEST) || defined(SQLITE_MUTATION_TEST)

  13327. # define ALWAYS(X)      (1)

  13328. # define NEVER(X)       (0)

  13329. #elif !defined(NDEBUG)

  13330. # define ALWAYS(X)      ((X)?1:(assert(0),0))

  13331. # define NEVER(X)       ((X)?(assert(0),1):0)

  13332. #else

  13333. # define ALWAYS(X)      (X)

  13334. # define NEVER(X)       (X)

  13335. #endif

  13336. 

  13337. /*

  13338. ** Some conditionals are optimizations only.  In other words, if the

  13339. ** conditionals are replaced with a constant 1 (true) or 0 (false) then

  13340. ** the correct answer is still obtained, though perhaps not as quickly.

  13341. **

  13342. ** The following macros mark these optimizations conditionals.

  13343. */

  13344. #if defined(SQLITE_MUTATION_TEST)

  13345. # define OK_IF_ALWAYS_TRUE(X)  (1)

  13346. # define OK_IF_ALWAYS_FALSE(X) (0)

  13347. #else

  13348. # define OK_IF_ALWAYS_TRUE(X)  (X)

  13349. # define OK_IF_ALWAYS_FALSE(X) (X)

  13350. #endif

  13351. 

  13352. /*

  13353. ** Some malloc failures are only possible if SQLITE_TEST_REALLOC_STRESS is

  13354. ** defined.  We need to defend against those failures when testing with

  13355. ** SQLITE_TEST_REALLOC_STRESS, but we don't want the unreachable branches

  13356. ** during a normal build.  The following macro can be used to disable tests

  13357. ** that are always false except when SQLITE_TEST_REALLOC_STRESS is set.

  13358. */

  13359. #if defined(SQLITE_TEST_REALLOC_STRESS)

  13360. # define ONLY_IF_REALLOC_STRESS(X)  (X)

  13361. #elif !defined(NDEBUG)

  13362. # define ONLY_IF_REALLOC_STRESS(X)  ((X)?(assert(0),1):0)

  13363. #else

  13364. # define ONLY_IF_REALLOC_STRESS(X)  (0)

  13365. #endif

  13366. 

  13367. /*

  13368. ** Declarations used for tracing the operating system interfaces.

  13369. */

  13370. #if defined(SQLITE_FORCE_OS_TRACE) || defined(SQLITE_TEST) || \

  13371.     (defined(SQLITE_DEBUG) && SQLITE_OS_WIN)

  13372.   extern int sqlite3OSTrace;

  13373. # define OSTRACE(X)          if( sqlite3OSTrace ) sqlite3DebugPrintf X

  13374. # define SQLITE_HAVE_OS_TRACE

  13375. #else

  13376. # define OSTRACE(X)

  13377. # undef  SQLITE_HAVE_OS_TRACE

  13378. #endif

  13379. 

  13380. /*

  13381. ** Is the sqlite3ErrName() function needed in the build?  Currently,

  13382. ** it is needed by "mutex_w32.c" (when debugging), "os_win.c" (when

  13383. ** OSTRACE is enabled), and by several "test*.c" files (which are

  13384. ** compiled using SQLITE_TEST).

  13385. */

  13386. #if defined(SQLITE_HAVE_OS_TRACE) || defined(SQLITE_TEST) || \

  13387.     (defined(SQLITE_DEBUG) && SQLITE_OS_WIN)

  13388. # define SQLITE_NEED_ERR_NAME

  13389. #else

  13390. # undef  SQLITE_NEED_ERR_NAME

  13391. #endif

  13392. 

  13393. /*

  13394. ** SQLITE_ENABLE_EXPLAIN_COMMENTS is incompatible with SQLITE_OMIT_EXPLAIN

  13395. */

  13396. #ifdef SQLITE_OMIT_EXPLAIN

  13397. # undef SQLITE_ENABLE_EXPLAIN_COMMENTS

  13398. #endif

  13399. 

  13400. /*

  13401. ** Return true (non-zero) if the input is an integer that is too large

  13402. ** to fit in 32-bits.  This macro is used inside of various testcase()

  13403. ** macros to verify that we have tested SQLite for large-file support.

  13404. */

  13405. #define IS_BIG_INT(X)  (((X)&~(i64)0xffffffff)!=0)

  13406. 

  13407. /*

  13408. ** The macro unlikely() is a hint that surrounds a boolean

  13409. ** expression that is usually false.  Macro likely() surrounds

  13410. ** a boolean expression that is usually true.  These hints could,

  13411. ** in theory, be used by the compiler to generate better code, but

  13412. ** currently they are just comments for human readers.

  13413. */

  13414. #define likely(X)    (X)

  13415. #define unlikely(X)  (X)

  13416. 

  13417. /************** Include hash.h in the middle of sqliteInt.h ******************/

  13418. /************** Begin file hash.h ********************************************/

  13419. /*

  13420. ** 2001 September 22

  13421. **

  13422. ** The author disclaims copyright to this source code.  In place of

  13423. ** a legal notice, here is a blessing:

  13424. **

  13425. **    May you do good and not evil.

  13426. **    May you find forgiveness for yourself and forgive others.

  13427. **    May you share freely, never taking more than you give.

  13428. **

  13429. *************************************************************************

  13430. ** This is the header file for the generic hash-table implementation

  13431. ** used in SQLite.

  13432. */

  13433. #ifndef SQLITE_HASH_H

  13434. #define SQLITE_HASH_H

  13435. 

  13436. /* Forward declarations of structures. */

  13437. typedef struct Hash Hash;

  13438. typedef struct HashElem HashElem;

  13439. 

  13440. /* A complete hash table is an instance of the following structure.

  13441. ** The internals of this structure are intended to be opaque -- client

  13442. ** code should not attempt to access or modify the fields of this structure

  13443. ** directly.  Change this structure only by using the routines below.

  13444. ** However, some of the "procedures" and "functions" for modifying and

  13445. ** accessing this structure are really macros, so we can't really make

  13446. ** this structure opaque.

  13447. **

  13448. ** All elements of the hash table are on a single doubly-linked list.

  13449. ** Hash.first points to the head of this list.

  13450. **

  13451. ** There are Hash.htsize buckets.  Each bucket points to a spot in

  13452. ** the global doubly-linked list.  The contents of the bucket are the

  13453. ** element pointed to plus the next _ht.count-1 elements in the list.

  13454. **

  13455. ** Hash.htsize and Hash.ht may be zero.  In that case lookup is done

  13456. ** by a linear search of the global list.  For small tables, the 

  13457. ** Hash.ht table is never allocated because if there are few elements

  13458. ** in the table, it is faster to do a linear search than to manage

  13459. ** the hash table.

  13460. */

  13461. struct Hash {

  13462.   unsigned int htsize;      /* Number of buckets in the hash table */

  13463.   unsigned int count;       /* Number of entries in this table */

  13464.   HashElem *first;          /* The first element of the array */

  13465.   struct _ht {              /* the hash table */

  13466.     unsigned int count;        /* Number of entries with this hash */

  13467.     HashElem *chain;           /* Pointer to first entry with this hash */

  13468.   } *ht;

  13469. };

  13470. 

  13471. /* Each element in the hash table is an instance of the following 

  13472. ** structure.  All elements are stored on a single doubly-linked list.

  13473. **

  13474. ** Again, this structure is intended to be opaque, but it can't really

  13475. ** be opaque because it is used by macros.

  13476. */

  13477. struct HashElem {

  13478.   HashElem *next, *prev;       /* Next and previous elements in the table */

  13479.   void *data;                  /* Data associated with this element */

  13480.   const char *pKey;            /* Key associated with this element */

  13481. };

  13482. 

  13483. /*

  13484. ** Access routines.  To delete, insert a NULL pointer.

  13485. */

  13486. SQLITE_PRIVATE void sqlite3HashInit(Hash*);

  13487. SQLITE_PRIVATE void *sqlite3HashInsert(Hash*, const char *pKey, void *pData);

  13488. SQLITE_PRIVATE void *sqlite3HashFind(const Hash*, const char *pKey);

  13489. SQLITE_PRIVATE void sqlite3HashClear(Hash*);

  13490. 

  13491. /*

  13492. ** Macros for looping over all elements of a hash table.  The idiom is

  13493. ** like this:

  13494. **

  13495. **   Hash h;

  13496. **   HashElem *p;

  13497. **   ...

  13498. **   for(p=sqliteHashFirst(&h); p; p=sqliteHashNext(p)){

  13499. **     SomeStructure *pData = sqliteHashData(p);

  13500. **     // do something with pData

  13501. **   }

  13502. */

  13503. #define sqliteHashFirst(H)  ((H)->first)

  13504. #define sqliteHashNext(E)   ((E)->next)

  13505. #define sqliteHashData(E)   ((E)->data)

  13506. /* #define sqliteHashKey(E)    ((E)->pKey) // NOT USED */

  13507. /* #define sqliteHashKeysize(E) ((E)->nKey)  // NOT USED */

  13508. 

  13509. /*

  13510. ** Number of entries in a hash table

  13511. */

  13512. /* #define sqliteHashCount(H)  ((H)->count) // NOT USED */

  13513. 

  13514. #endif /* SQLITE_HASH_H */

  13515. 

  13516. /************** End of hash.h ************************************************/

  13517. /************** Continuing where we left off in sqliteInt.h ******************/

  13518. /************** Include parse.h in the middle of sqliteInt.h *****************/

  13519. /************** Begin file parse.h *******************************************/

  13520. #define TK_SEMI                             1

  13521. #define TK_EXPLAIN                          2

  13522. #define TK_QUERY                            3

  13523. #define TK_PLAN                             4

  13524. #define TK_BEGIN                            5

  13525. #define TK_TRANSACTION                      6

  13526. #define TK_DEFERRED                         7

  13527. #define TK_IMMEDIATE                        8

  13528. #define TK_EXCLUSIVE                        9

  13529. #define TK_COMMIT                          10

  13530. #define TK_END                             11

  13531. #define TK_ROLLBACK                        12

  13532. #define TK_SAVEPOINT                       13

  13533. #define TK_RELEASE                         14

  13534. #define TK_TO                              15

  13535. #define TK_TABLE                           16

  13536. #define TK_CREATE                          17

  13537. #define TK_IF                              18

  13538. #define TK_NOT                             19

  13539. #define TK_EXISTS                          20

  13540. #define TK_TEMP                            21

  13541. #define TK_LP                              22

  13542. #define TK_RP                              23

  13543. #define TK_AS                              24

  13544. #define TK_WITHOUT                         25

  13545. #define TK_COMMA                           26

  13546. #define TK_ABORT                           27

  13547. #define TK_ACTION                          28

  13548. #define TK_AFTER                           29

  13549. #define TK_ANALYZE                         30

  13550. #define TK_ASC                             31

  13551. #define TK_ATTACH                          32

  13552. #define TK_BEFORE                          33

  13553. #define TK_BY                              34

  13554. #define TK_CASCADE                         35

  13555. #define TK_CAST                            36

  13556. #define TK_CONFLICT                        37

  13557. #define TK_DATABASE                        38

  13558. #define TK_DESC                            39

  13559. #define TK_DETACH                          40

  13560. #define TK_EACH                            41

  13561. #define TK_FAIL                            42

  13562. #define TK_OR                              43

  13563. #define TK_AND                             44

  13564. #define TK_IS                              45

  13565. #define TK_MATCH                           46

  13566. #define TK_LIKE_KW                         47

  13567. #define TK_BETWEEN                         48

  13568. #define TK_IN                              49

  13569. #define TK_ISNULL                          50

  13570. #define TK_NOTNULL                         51

  13571. #define TK_NE                              52

  13572. #define TK_EQ                              53

  13573. #define TK_GT                              54

  13574. #define TK_LE                              55

  13575. #define TK_LT                              56

  13576. #define TK_GE                              57

  13577. #define TK_ESCAPE                          58

  13578. #define TK_ID                              59

  13579. #define TK_COLUMNKW                        60

  13580. #define TK_DO                              61

  13581. #define TK_FOR                             62

  13582. #define TK_IGNORE                          63

  13583. #define TK_INITIALLY                       64

  13584. #define TK_INSTEAD                         65

  13585. #define TK_NO                              66

  13586. #define TK_KEY                             67

  13587. #define TK_OF                              68

  13588. #define TK_OFFSET                          69

  13589. #define TK_PRAGMA                          70

  13590. #define TK_RAISE                           71

  13591. #define TK_RECURSIVE                       72

  13592. #define TK_REPLACE                         73

  13593. #define TK_RESTRICT                        74

  13594. #define TK_ROW                             75

  13595. #define TK_ROWS                            76

  13596. #define TK_TRIGGER                         77

  13597. #define TK_VACUUM                          78

  13598. #define TK_VIEW                            79

  13599. #define TK_VIRTUAL                         80

  13600. #define TK_WITH                            81

  13601. #define TK_CURRENT                         82

  13602. #define TK_FOLLOWING                       83

  13603. #define TK_PARTITION                       84

  13604. #define TK_PRECEDING                       85

  13605. #define TK_RANGE                           86

  13606. #define TK_UNBOUNDED                       87

  13607. #define TK_EXCLUDE                         88

  13608. #define TK_GROUPS                          89

  13609. #define TK_OTHERS                          90

  13610. #define TK_TIES                            91

  13611. #define TK_REINDEX                         92

  13612. #define TK_RENAME                          93

  13613. #define TK_CTIME_KW                        94

  13614. #define TK_ANY                             95

  13615. #define TK_BITAND                          96

  13616. #define TK_BITOR                           97

  13617. #define TK_LSHIFT                          98

  13618. #define TK_RSHIFT                          99

  13619. #define TK_PLUS                           100

  13620. #define TK_MINUS                          101

  13621. #define TK_STAR                           102

  13622. #define TK_SLASH                          103

  13623. #define TK_REM                            104

  13624. #define TK_CONCAT                         105

  13625. #define TK_COLLATE                        106

  13626. #define TK_BITNOT                         107

  13627. #define TK_ON                             108

  13628. #define TK_INDEXED                        109

  13629. #define TK_STRING                         110

  13630. #define TK_JOIN_KW                        111

  13631. #define TK_CONSTRAINT                     112

  13632. #define TK_DEFAULT                        113

  13633. #define TK_NULL                           114

  13634. #define TK_PRIMARY                        115

  13635. #define TK_UNIQUE                         116

  13636. #define TK_CHECK                          117

  13637. #define TK_REFERENCES                     118

  13638. #define TK_AUTOINCR                       119

  13639. #define TK_INSERT                         120

  13640. #define TK_DELETE                         121

  13641. #define TK_UPDATE                         122

  13642. #define TK_SET                            123

  13643. #define TK_DEFERRABLE                     124

  13644. #define TK_FOREIGN                        125

  13645. #define TK_DROP                           126

  13646. #define TK_UNION                          127

  13647. #define TK_ALL                            128

  13648. #define TK_EXCEPT                         129

  13649. #define TK_INTERSECT                      130

  13650. #define TK_SELECT                         131

  13651. #define TK_VALUES                         132

  13652. #define TK_DISTINCT                       133

  13653. #define TK_DOT                            134

  13654. #define TK_FROM                           135

  13655. #define TK_JOIN                           136

  13656. #define TK_USING                          137

  13657. #define TK_ORDER                          138

  13658. #define TK_GROUP                          139

  13659. #define TK_HAVING                         140

  13660. #define TK_LIMIT                          141

  13661. #define TK_WHERE                          142

  13662. #define TK_INTO                           143

  13663. #define TK_NOTHING                        144

  13664. #define TK_FLOAT                          145

  13665. #define TK_BLOB                           146

  13666. #define TK_INTEGER                        147

  13667. #define TK_VARIABLE                       148

  13668. #define TK_CASE                           149

  13669. #define TK_WHEN                           150

  13670. #define TK_THEN                           151

  13671. #define TK_ELSE                           152

  13672. #define TK_INDEX                          153

  13673. #define TK_ALTER                          154

  13674. #define TK_ADD                            155

  13675. #define TK_WINDOW                         156

  13676. #define TK_OVER                           157

  13677. #define TK_FILTER                         158

  13678. #define TK_TRUEFALSE                      159

  13679. #define TK_ISNOT                          160

  13680. #define TK_FUNCTION                       161

  13681. #define TK_COLUMN                         162

  13682. #define TK_AGG_FUNCTION                   163

  13683. #define TK_AGG_COLUMN                     164

  13684. #define TK_UMINUS                         165

  13685. #define TK_UPLUS                          166

  13686. #define TK_TRUTH                          167

  13687. #define TK_REGISTER                       168

  13688. #define TK_VECTOR                         169

  13689. #define TK_SELECT_COLUMN                  170

  13690. #define TK_IF_NULL_ROW                    171

  13691. #define TK_ASTERISK                       172

  13692. #define TK_SPAN                           173

  13693. #define TK_SPACE                          174

  13694. #define TK_ILLEGAL                        175

  13695. 

  13696. /************** End of parse.h ***********************************************/

  13697. /************** Continuing where we left off in sqliteInt.h ******************/

  13698. #include <stdio.h>

  13699. #include <stdlib.h>

  13700. #include <string.h>

  13701. #include <assert.h>

  13702. #include <stddef.h>

  13703. 

  13704. /*

  13705. ** Use a macro to replace memcpy() if compiled with SQLITE_INLINE_MEMCPY.

  13706. ** This allows better measurements of where memcpy() is used when running

  13707. ** cachegrind.  But this macro version of memcpy() is very slow so it

  13708. ** should not be used in production.  This is a performance measurement

  13709. ** hack only.

  13710. */

  13711. #ifdef SQLITE_INLINE_MEMCPY

  13712. # define memcpy(D,S,N) {char*xxd=(char*)(D);const char*xxs=(const char*)(S);\

  13713.                         int xxn=(N);while(xxn-->0)*(xxd++)=*(xxs++);}

  13714. #endif

  13715. 

  13716. /*

  13717. ** If compiling for a processor that lacks floating point support,

  13718. ** substitute integer for floating-point

  13719. */

  13720. #ifdef SQLITE_OMIT_FLOATING_POINT

  13721. # define double sqlite_int64

  13722. # define float sqlite_int64

  13723. # define LONGDOUBLE_TYPE sqlite_int64

  13724. # ifndef SQLITE_BIG_DBL

  13725. #   define SQLITE_BIG_DBL (((sqlite3_int64)1)<<50)

  13726. # endif

  13727. # define SQLITE_OMIT_DATETIME_FUNCS 1

  13728. # define SQLITE_OMIT_TRACE 1

  13729. # undef SQLITE_MIXED_ENDIAN_64BIT_FLOAT

  13730. # undef SQLITE_HAVE_ISNAN

  13731. #endif

  13732. #ifndef SQLITE_BIG_DBL

  13733. # define SQLITE_BIG_DBL (1e99)

  13734. #endif

  13735. 

  13736. /*

  13737. ** OMIT_TEMPDB is set to 1 if SQLITE_OMIT_TEMPDB is defined, or 0

  13738. ** afterward. Having this macro allows us to cause the C compiler

  13739. ** to omit code used by TEMP tables without messy #ifndef statements.

  13740. */

  13741. #ifdef SQLITE_OMIT_TEMPDB

  13742. #define OMIT_TEMPDB 1

  13743. #else

  13744. #define OMIT_TEMPDB 0

  13745. #endif

  13746. 

  13747. /*

  13748. ** The "file format" number is an integer that is incremented whenever

  13749. ** the VDBE-level file format changes.  The following macros define the

  13750. ** the default file format for new databases and the maximum file format

  13751. ** that the library can read.

  13752. */

  13753. #define SQLITE_MAX_FILE_FORMAT 4

  13754. #ifndef SQLITE_DEFAULT_FILE_FORMAT

  13755. # define SQLITE_DEFAULT_FILE_FORMAT 4

  13756. #endif

  13757. 

  13758. /*

  13759. ** Determine whether triggers are recursive by default.  This can be

  13760. ** changed at run-time using a pragma.

  13761. */

  13762. #ifndef SQLITE_DEFAULT_RECURSIVE_TRIGGERS

  13763. # define SQLITE_DEFAULT_RECURSIVE_TRIGGERS 0

  13764. #endif

  13765. 

  13766. /*

  13767. ** Provide a default value for SQLITE_TEMP_STORE in case it is not specified

  13768. ** on the command-line

  13769. */

  13770. #ifndef SQLITE_TEMP_STORE

  13771. # define SQLITE_TEMP_STORE 1

  13772. #endif

  13773. 

  13774. /*

  13775. ** If no value has been provided for SQLITE_MAX_WORKER_THREADS, or if

  13776. ** SQLITE_TEMP_STORE is set to 3 (never use temporary files), set it

  13777. ** to zero.

  13778. */

  13779. #if SQLITE_TEMP_STORE==3 || SQLITE_THREADSAFE==0

  13780. # undef SQLITE_MAX_WORKER_THREADS

  13781. # define SQLITE_MAX_WORKER_THREADS 0

  13782. #endif

  13783. #ifndef SQLITE_MAX_WORKER_THREADS

  13784. # define SQLITE_MAX_WORKER_THREADS 8

  13785. #endif

  13786. #ifndef SQLITE_DEFAULT_WORKER_THREADS

  13787. # define SQLITE_DEFAULT_WORKER_THREADS 0

  13788. #endif

  13789. #if SQLITE_DEFAULT_WORKER_THREADS>SQLITE_MAX_WORKER_THREADS

  13790. # undef SQLITE_MAX_WORKER_THREADS

  13791. # define SQLITE_MAX_WORKER_THREADS SQLITE_DEFAULT_WORKER_THREADS

  13792. #endif

  13793. 

  13794. /*

  13795. ** The default initial allocation for the pagecache when using separate

  13796. ** pagecaches for each database connection.  A positive number is the

  13797. ** number of pages.  A negative number N translations means that a buffer

  13798. ** of -1024*N bytes is allocated and used for as many pages as it will hold.

  13799. **

  13800. ** The default value of "20" was choosen to minimize the run-time of the

  13801. ** speedtest1 test program with options: --shrink-memory --reprepare

  13802. */

  13803. #ifndef SQLITE_DEFAULT_PCACHE_INITSZ

  13804. # define SQLITE_DEFAULT_PCACHE_INITSZ 20

  13805. #endif

  13806. 

  13807. /*

  13808. ** Default value for the SQLITE_CONFIG_SORTERREF_SIZE option.

  13809. */

  13810. #ifndef SQLITE_DEFAULT_SORTERREF_SIZE

  13811. # define SQLITE_DEFAULT_SORTERREF_SIZE 0x7fffffff

  13812. #endif

  13813. 

  13814. /*

  13815. ** The compile-time options SQLITE_MMAP_READWRITE and 

  13816. ** SQLITE_ENABLE_BATCH_ATOMIC_WRITE are not compatible with one another.

  13817. ** You must choose one or the other (or neither) but not both.

  13818. */

  13819. #if defined(SQLITE_MMAP_READWRITE) && defined(SQLITE_ENABLE_BATCH_ATOMIC_WRITE)

  13820. #error Cannot use both SQLITE_MMAP_READWRITE and SQLITE_ENABLE_BATCH_ATOMIC_WRITE

  13821. #endif

  13822. 

  13823. /*

  13824. ** GCC does not define the offsetof() macro so we'll have to do it

  13825. ** ourselves.

  13826. */

  13827. #ifndef offsetof

  13828. #define offsetof(STRUCTURE,FIELD) ((int)((char*)&((STRUCTURE*)0)->FIELD))

  13829. #endif

  13830. 

  13831. /*

  13832. ** Macros to compute minimum and maximum of two numbers.

  13833. */

  13834. #ifndef MIN

  13835. # define MIN(A,B) ((A)<(B)?(A):(B))

  13836. #endif

  13837. #ifndef MAX

  13838. # define MAX(A,B) ((A)>(B)?(A):(B))

  13839. #endif

  13840. 

  13841. /*

  13842. ** Swap two objects of type TYPE.

  13843. */

  13844. #define SWAP(TYPE,A,B) {TYPE t=A; A=B; B=t;}

  13845. 

  13846. /*

  13847. ** Check to see if this machine uses EBCDIC.  (Yes, believe it or

  13848. ** not, there are still machines out there that use EBCDIC.)

  13849. */

  13850. #if 'A' == '\301'

  13851. # define SQLITE_EBCDIC 1

  13852. #else

  13853. # define SQLITE_ASCII 1

  13854. #endif

  13855. 

  13856. /*

  13857. ** Integers of known sizes.  These typedefs might change for architectures

  13858. ** where the sizes very.  Preprocessor macros are available so that the

  13859. ** types can be conveniently redefined at compile-type.  Like this:

  13860. **

  13861. **         cc '-DUINTPTR_TYPE=long long int' ...

  13862. */

  13863. #ifndef UINT32_TYPE

  13864. # ifdef HAVE_UINT32_T

  13865. #  define UINT32_TYPE uint32_t

  13866. # else

  13867. #  define UINT32_TYPE unsigned int

  13868. # endif

  13869. #endif

  13870. #ifndef UINT16_TYPE

  13871. # ifdef HAVE_UINT16_T

  13872. #  define UINT16_TYPE uint16_t

  13873. # else

  13874. #  define UINT16_TYPE unsigned short int

  13875. # endif

  13876. #endif

  13877. #ifndef INT16_TYPE

  13878. # ifdef HAVE_INT16_T

  13879. #  define INT16_TYPE int16_t

  13880. # else

  13881. #  define INT16_TYPE short int

  13882. # endif

  13883. #endif

  13884. #ifndef UINT8_TYPE

  13885. # ifdef HAVE_UINT8_T

  13886. #  define UINT8_TYPE uint8_t

  13887. # else

  13888. #  define UINT8_TYPE unsigned char

  13889. # endif

  13890. #endif

  13891. #ifndef INT8_TYPE

  13892. # ifdef HAVE_INT8_T

  13893. #  define INT8_TYPE int8_t

  13894. # else

  13895. #  define INT8_TYPE signed char

  13896. # endif

  13897. #endif

  13898. #ifndef LONGDOUBLE_TYPE

  13899. # define LONGDOUBLE_TYPE long double

  13900. #endif

  13901. typedef sqlite_int64 i64;          /* 8-byte signed integer */

  13902. typedef sqlite_uint64 u64;         /* 8-byte unsigned integer */

  13903. typedef UINT32_TYPE u32;           /* 4-byte unsigned integer */

  13904. typedef UINT16_TYPE u16;           /* 2-byte unsigned integer */

  13905. typedef INT16_TYPE i16;            /* 2-byte signed integer */

  13906. typedef UINT8_TYPE u8;             /* 1-byte unsigned integer */

  13907. typedef INT8_TYPE i8;              /* 1-byte signed integer */

  13908. 

  13909. /*

  13910. ** SQLITE_MAX_U32 is a u64 constant that is the maximum u64 value

  13911. ** that can be stored in a u32 without loss of data.  The value

  13912. ** is 0x00000000ffffffff.  But because of quirks of some compilers, we

  13913. ** have to specify the value in the less intuitive manner shown:

  13914. */

  13915. #define SQLITE_MAX_U32  ((((u64)1)<<32)-1)

  13916. 

  13917. /*

  13918. ** The datatype used to store estimates of the number of rows in a

  13919. ** table or index.  This is an unsigned integer type.  For 99.9% of

  13920. ** the world, a 32-bit integer is sufficient.  But a 64-bit integer

  13921. ** can be used at compile-time if desired.

  13922. */

  13923. #ifdef SQLITE_64BIT_STATS

  13924.  typedef u64 tRowcnt;    /* 64-bit only if requested at compile-time */

  13925. #else

  13926.  typedef u32 tRowcnt;    /* 32-bit is the default */

  13927. #endif

  13928. 

  13929. /*

  13930. ** Estimated quantities used for query planning are stored as 16-bit

  13931. ** logarithms.  For quantity X, the value stored is 10*log2(X).  This

  13932. ** gives a possible range of values of approximately 1.0e986 to 1e-986.

  13933. ** But the allowed values are "grainy".  Not every value is representable.

  13934. ** For example, quantities 16 and 17 are both represented by a LogEst

  13935. ** of 40.  However, since LogEst quantities are suppose to be estimates,

  13936. ** not exact values, this imprecision is not a problem.

  13937. **

  13938. ** "LogEst" is short for "Logarithmic Estimate".

  13939. **

  13940. ** Examples:

  13941. **      1 -> 0              20 -> 43          10000 -> 132

  13942. **      2 -> 10             25 -> 46          25000 -> 146

  13943. **      3 -> 16            100 -> 66        1000000 -> 199

  13944. **      4 -> 20           1000 -> 99        1048576 -> 200

  13945. **     10 -> 33           1024 -> 100    4294967296 -> 320

  13946. **

  13947. ** The LogEst can be negative to indicate fractional values.

  13948. ** Examples:

  13949. **

  13950. **    0.5 -> -10           0.1 -> -33        0.0625 -> -40

  13951. */

  13952. typedef INT16_TYPE LogEst;

  13953. 

  13954. /*

  13955. ** Set the SQLITE_PTRSIZE macro to the number of bytes in a pointer

  13956. */

  13957. #ifndef SQLITE_PTRSIZE

  13958. # if defined(__SIZEOF_POINTER__)

  13959. #   define SQLITE_PTRSIZE __SIZEOF_POINTER__

  13960. # elif defined(i386)     || defined(__i386__)   || defined(_M_IX86) ||    \

  13961.        defined(_M_ARM)   || defined(__arm__)    || defined(__x86)   ||    \

  13962.       (defined(__TOS_AIX__) && !defined(__64BIT__))

  13963. #   define SQLITE_PTRSIZE 4

  13964. # else

  13965. #   define SQLITE_PTRSIZE 8

  13966. # endif

  13967. #endif

  13968. 

  13969. /* The uptr type is an unsigned integer large enough to hold a pointer

  13970. */

  13971. #if defined(HAVE_STDINT_H)

  13972.   typedef uintptr_t uptr;

  13973. #elif SQLITE_PTRSIZE==4

  13974.   typedef u32 uptr;

  13975. #else

  13976.   typedef u64 uptr;

  13977. #endif

  13978. 

  13979. /*

  13980. ** The SQLITE_WITHIN(P,S,E) macro checks to see if pointer P points to

  13981. ** something between S (inclusive) and E (exclusive).

  13982. **

  13983. ** In other words, S is a buffer and E is a pointer to the first byte after

  13984. ** the end of buffer S.  This macro returns true if P points to something

  13985. ** contained within the buffer S.

  13986. */

  13987. #define SQLITE_WITHIN(P,S,E) (((uptr)(P)>=(uptr)(S))&&((uptr)(P)<(uptr)(E)))

  13988. 

  13989. 

  13990. /*

  13991. ** Macros to determine whether the machine is big or little endian,

  13992. ** and whether or not that determination is run-time or compile-time.

  13993. **

  13994. ** For best performance, an attempt is made to guess at the byte-order

  13995. ** using C-preprocessor macros.  If that is unsuccessful, or if

  13996. ** -DSQLITE_BYTEORDER=0 is set, then byte-order is determined

  13997. ** at run-time.

  13998. */

  13999. #ifndef SQLITE_BYTEORDER

  14000. # if defined(i386)      || defined(__i386__)      || defined(_M_IX86) ||    \

  14001.      defined(__x86_64)  || defined(__x86_64__)    || defined(_M_X64)  ||    \

  14002.      defined(_M_AMD64)  || defined(_M_ARM)        || defined(__x86)   ||    \

  14003.      defined(__ARMEL__) || defined(__AARCH64EL__) || defined(_M_ARM64)

  14004. #   define SQLITE_BYTEORDER    1234

  14005. # elif defined(sparc)     || defined(__ppc__) || \

  14006.        defined(__ARMEB__) || defined(__AARCH64EB__)

  14007. #   define SQLITE_BYTEORDER    4321

  14008. # else

  14009. #   define SQLITE_BYTEORDER 0

  14010. # endif

  14011. #endif

  14012. #if SQLITE_BYTEORDER==4321

  14013. # define SQLITE_BIGENDIAN    1

  14014. # define SQLITE_LITTLEENDIAN 0

  14015. # define SQLITE_UTF16NATIVE  SQLITE_UTF16BE

  14016. #elif SQLITE_BYTEORDER==1234

  14017. # define SQLITE_BIGENDIAN    0

  14018. # define SQLITE_LITTLEENDIAN 1

  14019. # define SQLITE_UTF16NATIVE  SQLITE_UTF16LE

  14020. #else

  14021. # ifdef SQLITE_AMALGAMATION

  14022.   const int sqlite3one = 1;

  14023. # else

  14024.   extern const int sqlite3one;

  14025. # endif

  14026. # define SQLITE_BIGENDIAN    (*(char *)(&sqlite3one)==0)

  14027. # define SQLITE_LITTLEENDIAN (*(char *)(&sqlite3one)==1)

  14028. # define SQLITE_UTF16NATIVE  (SQLITE_BIGENDIAN?SQLITE_UTF16BE:SQLITE_UTF16LE)

  14029. #endif

  14030. 

  14031. /*

  14032. ** Constants for the largest and smallest possible 64-bit signed integers.

  14033. ** These macros are designed to work correctly on both 32-bit and 64-bit

  14034. ** compilers.

  14035. */

  14036. #define LARGEST_INT64  (0xffffffff|(((i64)0x7fffffff)<<32))

  14037. #define SMALLEST_INT64 (((i64)-1) - LARGEST_INT64)

  14038. 

  14039. /*

  14040. ** Round up a number to the next larger multiple of 8.  This is used

  14041. ** to force 8-byte alignment on 64-bit architectures.

  14042. */

  14043. #define ROUND8(x)     (((x)+7)&~7)

  14044. 

  14045. /*

  14046. ** Round down to the nearest multiple of 8

  14047. */

  14048. #define ROUNDDOWN8(x) ((x)&~7)

  14049. 

  14050. /*

  14051. ** Assert that the pointer X is aligned to an 8-byte boundary.  This

  14052. ** macro is used only within assert() to verify that the code gets

  14053. ** all alignment restrictions correct.

  14054. **

  14055. ** Except, if SQLITE_4_BYTE_ALIGNED_MALLOC is defined, then the

  14056. ** underlying malloc() implementation might return us 4-byte aligned

  14057. ** pointers.  In that case, only verify 4-byte alignment.

  14058. */

  14059. #ifdef SQLITE_4_BYTE_ALIGNED_MALLOC

  14060. # define EIGHT_BYTE_ALIGNMENT(X)   ((((char*)(X) - (char*)0)&3)==0)

  14061. #else

  14062. # define EIGHT_BYTE_ALIGNMENT(X)   ((((char*)(X) - (char*)0)&7)==0)

  14063. #endif

  14064. 

  14065. /*

  14066. ** Disable MMAP on platforms where it is known to not work

  14067. */

  14068. #if defined(__OpenBSD__) || defined(__QNXNTO__)

  14069. # undef SQLITE_MAX_MMAP_SIZE

  14070. # define SQLITE_MAX_MMAP_SIZE 0

  14071. #endif

  14072. 

  14073. /*

  14074. ** Default maximum size of memory used by memory-mapped I/O in the VFS

  14075. */

  14076. #ifdef __APPLE__

  14077. # include <TargetConditionals.h>

  14078. #endif

  14079. #ifndef SQLITE_MAX_MMAP_SIZE

  14080. # if defined(__linux__) \

  14081.   || defined(_WIN32) \

  14082.   || (defined(__APPLE__) && defined(__MACH__)) \

  14083.   || defined(__sun) \

  14084.   || defined(__FreeBSD__) \

  14085.   || defined(__DragonFly__)

  14086. #   define SQLITE_MAX_MMAP_SIZE 0x7fff0000  /* 2147418112 */

  14087. # else

  14088. #   define SQLITE_MAX_MMAP_SIZE 0

  14089. # endif

  14090. #endif

  14091. 

  14092. /*

  14093. ** The default MMAP_SIZE is zero on all platforms.  Or, even if a larger

  14094. ** default MMAP_SIZE is specified at compile-time, make sure that it does

  14095. ** not exceed the maximum mmap size.

  14096. */

  14097. #ifndef SQLITE_DEFAULT_MMAP_SIZE

  14098. # define SQLITE_DEFAULT_MMAP_SIZE 0

  14099. #endif

  14100. #if SQLITE_DEFAULT_MMAP_SIZE>SQLITE_MAX_MMAP_SIZE

  14101. # undef SQLITE_DEFAULT_MMAP_SIZE

  14102. # define SQLITE_DEFAULT_MMAP_SIZE SQLITE_MAX_MMAP_SIZE

  14103. #endif

  14104. 

  14105. /*

  14106. ** Only one of SQLITE_ENABLE_STAT3 or SQLITE_ENABLE_STAT4 can be defined.

  14107. ** Priority is given to SQLITE_ENABLE_STAT4.  If either are defined, also

  14108. ** define SQLITE_ENABLE_STAT3_OR_STAT4

  14109. */

  14110. #ifdef SQLITE_ENABLE_STAT4

  14111. # undef SQLITE_ENABLE_STAT3

  14112. # define SQLITE_ENABLE_STAT3_OR_STAT4 1

  14113. #elif SQLITE_ENABLE_STAT3

  14114. # define SQLITE_ENABLE_STAT3_OR_STAT4 1

  14115. #elif SQLITE_ENABLE_STAT3_OR_STAT4

  14116. # undef SQLITE_ENABLE_STAT3_OR_STAT4

  14117. #endif

  14118. 

  14119. /*

  14120. ** SELECTTRACE_ENABLED will be either 1 or 0 depending on whether or not

  14121. ** the Select query generator tracing logic is turned on.

  14122. */

  14123. #if defined(SQLITE_ENABLE_SELECTTRACE)

  14124. # define SELECTTRACE_ENABLED 1

  14125. #else

  14126. # define SELECTTRACE_ENABLED 0

  14127. #endif

  14128. 

  14129. /*

  14130. ** An instance of the following structure is used to store the busy-handler

  14131. ** callback for a given sqlite handle.

  14132. **

  14133. ** The sqlite.busyHandler member of the sqlite struct contains the busy

  14134. ** callback for the database handle. Each pager opened via the sqlite

  14135. ** handle is passed a pointer to sqlite.busyHandler. The busy-handler

  14136. ** callback is currently invoked only from within pager.c.

  14137. */

  14138. typedef struct BusyHandler BusyHandler;

  14139. struct BusyHandler {

  14140.   int (*xBusyHandler)(void *,int);  /* The busy callback */

  14141.   void *pBusyArg;                   /* First arg to busy callback */

  14142.   int nBusy;                        /* Incremented with each busy call */

  14143.   u8 bExtraFileArg;                 /* Include sqlite3_file as callback arg */

  14144. };

  14145. 

  14146. /*

  14147. ** Name of the master database table.  The master database table

  14148. ** is a special table that holds the names and attributes of all

  14149. ** user tables and indices.

  14150. */

  14151. #define MASTER_NAME       "sqlite_master"

  14152. #define TEMP_MASTER_NAME  "sqlite_temp_master"

  14153. 

  14154. /*

  14155. ** The root-page of the master database table.

  14156. */

  14157. #define MASTER_ROOT       1

  14158. 

  14159. /*

  14160. ** The name of the schema table.

  14161. */

  14162. #define SCHEMA_TABLE(x)  ((!OMIT_TEMPDB)&&(x==1)?TEMP_MASTER_NAME:MASTER_NAME)

  14163. 

  14164. /*

  14165. ** A convenience macro that returns the number of elements in

  14166. ** an array.

  14167. */

  14168. #define ArraySize(X)    ((int)(sizeof(X)/sizeof(X[0])))

  14169. 

  14170. /*

  14171. ** Determine if the argument is a power of two

  14172. */

  14173. #define IsPowerOfTwo(X) (((X)&((X)-1))==0)

  14174. 

  14175. /*

  14176. ** The following value as a destructor means to use sqlite3DbFree().

  14177. ** The sqlite3DbFree() routine requires two parameters instead of the

  14178. ** one parameter that destructors normally want.  So we have to introduce

  14179. ** this magic value that the code knows to handle differently.  Any

  14180. ** pointer will work here as long as it is distinct from SQLITE_STATIC

  14181. ** and SQLITE_TRANSIENT.

  14182. */

  14183. #define SQLITE_DYNAMIC   ((sqlite3_destructor_type)sqlite3MallocSize)

  14184. 

  14185. /*

  14186. ** When SQLITE_OMIT_WSD is defined, it means that the target platform does

  14187. ** not support Writable Static Data (WSD) such as global and static variables.

  14188. ** All variables must either be on the stack or dynamically allocated from

  14189. ** the heap.  When WSD is unsupported, the variable declarations scattered

  14190. ** throughout the SQLite code must become constants instead.  The SQLITE_WSD

  14191. ** macro is used for this purpose.  And instead of referencing the variable

  14192. ** directly, we use its constant as a key to lookup the run-time allocated

  14193. ** buffer that holds real variable.  The constant is also the initializer

  14194. ** for the run-time allocated buffer.

  14195. **

  14196. ** In the usual case where WSD is supported, the SQLITE_WSD and GLOBAL

  14197. ** macros become no-ops and have zero performance impact.

  14198. */

  14199. #ifdef SQLITE_OMIT_WSD

  14200.   #define SQLITE_WSD const

  14201.   #define GLOBAL(t,v) (*(t*)sqlite3_wsd_find((void*)&(v), sizeof(v)))

  14202.   #define sqlite3GlobalConfig GLOBAL(struct Sqlite3Config, sqlite3Config)

  14203. SQLITE_API int sqlite3_wsd_init(int N, int J);

  14204. SQLITE_API void *sqlite3_wsd_find(void *K, int L);

  14205. #else

  14206.   #define SQLITE_WSD

  14207.   #define GLOBAL(t,v) v

  14208.   #define sqlite3GlobalConfig sqlite3Config

  14209. #endif

  14210. 

  14211. /*

  14212. ** The following macros are used to suppress compiler warnings and to

  14213. ** make it clear to human readers when a function parameter is deliberately

  14214. ** left unused within the body of a function. This usually happens when

  14215. ** a function is called via a function pointer. For example the

  14216. ** implementation of an SQL aggregate step callback may not use the

  14217. ** parameter indicating the number of arguments passed to the aggregate,

  14218. ** if it knows that this is enforced elsewhere.

  14219. **

  14220. ** When a function parameter is not used at all within the body of a function,

  14221. ** it is generally named "NotUsed" or "NotUsed2" to make things even clearer.

  14222. ** However, these macros may also be used to suppress warnings related to

  14223. ** parameters that may or may not be used depending on compilation options.

  14224. ** For example those parameters only used in assert() statements. In these

  14225. ** cases the parameters are named as per the usual conventions.

  14226. */

  14227. #define UNUSED_PARAMETER(x) (void)(x)

  14228. #define UNUSED_PARAMETER2(x,y) UNUSED_PARAMETER(x),UNUSED_PARAMETER(y)

  14229. 

  14230. /*

  14231. ** Forward references to structures

  14232. */

  14233. typedef struct AggInfo AggInfo;

  14234. typedef struct AuthContext AuthContext;

  14235. typedef struct AutoincInfo AutoincInfo;

  14236. typedef struct Bitvec Bitvec;

  14237. typedef struct CollSeq CollSeq;

  14238. typedef struct Column Column;

  14239. typedef struct Db Db;

  14240. typedef struct Schema Schema;

  14241. typedef struct Expr Expr;

  14242. typedef struct ExprList ExprList;

  14243. typedef struct FKey FKey;

  14244. typedef struct FuncDestructor FuncDestructor;

  14245. typedef struct FuncDef FuncDef;

  14246. typedef struct FuncDefHash FuncDefHash;

  14247. typedef struct IdList IdList;

  14248. typedef struct Index Index;

  14249. typedef struct IndexSample IndexSample;

  14250. typedef struct KeyClass KeyClass;

  14251. typedef struct KeyInfo KeyInfo;

  14252. typedef struct Lookaside Lookaside;

  14253. typedef struct LookasideSlot LookasideSlot;

  14254. typedef struct Module Module;

  14255. typedef struct NameContext NameContext;

  14256. typedef struct Parse Parse;

  14257. typedef struct PreUpdate PreUpdate;

  14258. typedef struct PrintfArguments PrintfArguments;

  14259. typedef struct RenameToken RenameToken;

  14260. typedef struct RowSet RowSet;

  14261. typedef struct Savepoint Savepoint;

  14262. typedef struct Select Select;

  14263. typedef struct SQLiteThread SQLiteThread;

  14264. typedef struct SelectDest SelectDest;

  14265. typedef struct SrcList SrcList;

  14266. typedef struct sqlite3_str StrAccum; /* Internal alias for sqlite3_str */

  14267. typedef struct Table Table;

  14268. typedef struct TableLock TableLock;

  14269. typedef struct Token Token;

  14270. typedef struct TreeView TreeView;

  14271. typedef struct Trigger Trigger;

  14272. typedef struct TriggerPrg TriggerPrg;

  14273. typedef struct TriggerStep TriggerStep;

  14274. typedef struct UnpackedRecord UnpackedRecord;

  14275. typedef struct Upsert Upsert;

  14276. typedef struct VTable VTable;

  14277. typedef struct VtabCtx VtabCtx;

  14278. typedef struct Walker Walker;

  14279. typedef struct WhereInfo WhereInfo;

  14280. typedef struct Window Window;

  14281. typedef struct With With;

  14282. 

  14283. 

  14284. /*

  14285. ** The bitmask datatype defined below is used for various optimizations.

  14286. **

  14287. ** Changing this from a 64-bit to a 32-bit type limits the number of

  14288. ** tables in a join to 32 instead of 64.  But it also reduces the size

  14289. ** of the library by 738 bytes on ix86.

  14290. */

  14291. #ifdef SQLITE_BITMASK_TYPE

  14292.   typedef SQLITE_BITMASK_TYPE Bitmask;

  14293. #else

  14294.   typedef u64 Bitmask;

  14295. #endif

  14296. 

  14297. /*

  14298. ** The number of bits in a Bitmask.  "BMS" means "BitMask Size".

  14299. */

  14300. #define BMS  ((int)(sizeof(Bitmask)*8))

  14301. 

  14302. /*

  14303. ** A bit in a Bitmask

  14304. */

  14305. #define MASKBIT(n)   (((Bitmask)1)<<(n))

  14306. #define MASKBIT32(n) (((unsigned int)1)<<(n))

  14307. #define ALLBITS      ((Bitmask)-1)

  14308. 

  14309. /* A VList object records a mapping between parameters/variables/wildcards

  14310. ** in the SQL statement (such as $abc, @pqr, or :xyz) and the integer

  14311. ** variable number associated with that parameter.  See the format description

  14312. ** on the sqlite3VListAdd() routine for more information.  A VList is really

  14313. ** just an array of integers.

  14314. */

  14315. typedef int VList;

  14316. 

  14317. /*

  14318. ** Defer sourcing vdbe.h and btree.h until after the "u8" and

  14319. ** "BusyHandler" typedefs. vdbe.h also requires a few of the opaque

  14320. ** pointer types (i.e. FuncDef) defined above.

  14321. */

  14322. /************** Include btree.h in the middle of sqliteInt.h *****************/

  14323. /************** Begin file btree.h *******************************************/

  14324. /*

  14325. ** 2001 September 15

  14326. **

  14327. ** The author disclaims copyright to this source code.  In place of

  14328. ** a legal notice, here is a blessing:

  14329. **

  14330. **    May you do good and not evil.

  14331. **    May you find forgiveness for yourself and forgive others.

  14332. **    May you share freely, never taking more than you give.

  14333. **

  14334. *************************************************************************

  14335. ** This header file defines the interface that the sqlite B-Tree file

  14336. ** subsystem.  See comments in the source code for a detailed description

  14337. ** of what each interface routine does.

  14338. */

  14339. #ifndef SQLITE_BTREE_H

  14340. #define SQLITE_BTREE_H

  14341. 

  14342. /* TODO: This definition is just included so other modules compile. It

  14343. ** needs to be revisited.

  14344. */

  14345. #define SQLITE_N_BTREE_META 16

  14346. 

  14347. /*

  14348. ** If defined as non-zero, auto-vacuum is enabled by default. Otherwise

  14349. ** it must be turned on for each database using "PRAGMA auto_vacuum = 1".

  14350. */

  14351. #ifndef SQLITE_DEFAULT_AUTOVACUUM

  14352.   #define SQLITE_DEFAULT_AUTOVACUUM 0

  14353. #endif

  14354. 

  14355. #define BTREE_AUTOVACUUM_NONE 0        /* Do not do auto-vacuum */

  14356. #define BTREE_AUTOVACUUM_FULL 1        /* Do full auto-vacuum */

  14357. #define BTREE_AUTOVACUUM_INCR 2        /* Incremental vacuum */

  14358. 

  14359. /*

  14360. ** Forward declarations of structure

  14361. */

  14362. typedef struct Btree Btree;

  14363. typedef struct BtCursor BtCursor;

  14364. typedef struct BtShared BtShared;

  14365. typedef struct BtreePayload BtreePayload;

  14366. 

  14367. 

  14368. SQLITE_PRIVATE int sqlite3BtreeOpen(

  14369.   sqlite3_vfs *pVfs,       /* VFS to use with this b-tree */

  14370.   const char *zFilename,   /* Name of database file to open */

  14371.   sqlite3 *db,             /* Associated database connection */

  14372.   Btree **ppBtree,         /* Return open Btree* here */

  14373.   int flags,               /* Flags */

  14374.   int vfsFlags             /* Flags passed through to VFS open */

  14375. );

  14376. 

  14377. /* The flags parameter to sqlite3BtreeOpen can be the bitwise or of the

  14378. ** following values.

  14379. **

  14380. ** NOTE:  These values must match the corresponding PAGER_ values in

  14381. ** pager.h.

  14382. */

  14383. #define BTREE_OMIT_JOURNAL  1  /* Do not create or use a rollback journal */

  14384. #define BTREE_MEMORY        2  /* This is an in-memory DB */

  14385. #define BTREE_SINGLE        4  /* The file contains at most 1 b-tree */

  14386. #define BTREE_UNORDERED     8  /* Use of a hash implementation is OK */

  14387. 

  14388. SQLITE_PRIVATE int sqlite3BtreeClose(Btree*);

  14389. SQLITE_PRIVATE int sqlite3BtreeSetCacheSize(Btree*,int);

  14390. SQLITE_PRIVATE int sqlite3BtreeSetSpillSize(Btree*,int);

  14391. #if SQLITE_MAX_MMAP_SIZE>0

  14392. SQLITE_PRIVATE   int sqlite3BtreeSetMmapLimit(Btree*,sqlite3_int64);

  14393. #endif

  14394. SQLITE_PRIVATE int sqlite3BtreeSetPagerFlags(Btree*,unsigned);

  14395. SQLITE_PRIVATE int sqlite3BtreeSetPageSize(Btree *p, int nPagesize, int nReserve, int eFix);

  14396. SQLITE_PRIVATE int sqlite3BtreeGetPageSize(Btree*);

  14397. SQLITE_PRIVATE int sqlite3BtreeMaxPageCount(Btree*,int);

  14398. SQLITE_PRIVATE u32 sqlite3BtreeLastPage(Btree*);

  14399. SQLITE_PRIVATE int sqlite3BtreeSecureDelete(Btree*,int);

  14400. SQLITE_PRIVATE int sqlite3BtreeGetOptimalReserve(Btree*);

  14401. SQLITE_PRIVATE int sqlite3BtreeGetReserveNoMutex(Btree *p);

  14402. SQLITE_PRIVATE int sqlite3BtreeSetAutoVacuum(Btree *, int);

  14403. SQLITE_PRIVATE int sqlite3BtreeGetAutoVacuum(Btree *);

  14404. SQLITE_PRIVATE int sqlite3BtreeBeginTrans(Btree*,int,int*);

  14405. SQLITE_PRIVATE int sqlite3BtreeCommitPhaseOne(Btree*, const char *zMaster);

  14406. SQLITE_PRIVATE int sqlite3BtreeCommitPhaseTwo(Btree*, int);

  14407. SQLITE_PRIVATE int sqlite3BtreeCommit(Btree*);

  14408. SQLITE_PRIVATE int sqlite3BtreeRollback(Btree*,int,int);

  14409. SQLITE_PRIVATE int sqlite3BtreeBeginStmt(Btree*,int);

  14410. SQLITE_PRIVATE int sqlite3BtreeCreateTable(Btree*, int*, int flags);

  14411. SQLITE_PRIVATE int sqlite3BtreeIsInTrans(Btree*);

  14412. SQLITE_PRIVATE int sqlite3BtreeIsInReadTrans(Btree*);

  14413. SQLITE_PRIVATE int sqlite3BtreeIsInBackup(Btree*);

  14414. SQLITE_PRIVATE void *sqlite3BtreeSchema(Btree *, int, void(*)(void *));

  14415. SQLITE_PRIVATE int sqlite3BtreeSchemaLocked(Btree *pBtree);

  14416. #ifndef SQLITE_OMIT_SHARED_CACHE

  14417. SQLITE_PRIVATE int sqlite3BtreeLockTable(Btree *pBtree, int iTab, u8 isWriteLock);

  14418. #endif

  14419. SQLITE_PRIVATE int sqlite3BtreeSavepoint(Btree *, int, int);

  14420. 

  14421. SQLITE_PRIVATE const char *sqlite3BtreeGetFilename(Btree *);

  14422. SQLITE_PRIVATE const char *sqlite3BtreeGetJournalname(Btree *);

  14423. SQLITE_PRIVATE int sqlite3BtreeCopyFile(Btree *, Btree *);

  14424. 

  14425. SQLITE_PRIVATE int sqlite3BtreeIncrVacuum(Btree *);

  14426. 

  14427. /* The flags parameter to sqlite3BtreeCreateTable can be the bitwise OR

  14428. ** of the flags shown below.

  14429. **

  14430. ** Every SQLite table must have either BTREE_INTKEY or BTREE_BLOBKEY set.

  14431. ** With BTREE_INTKEY, the table key is a 64-bit integer and arbitrary data

  14432. ** is stored in the leaves.  (BTREE_INTKEY is used for SQL tables.)  With

  14433. ** BTREE_BLOBKEY, the key is an arbitrary BLOB and no content is stored

  14434. ** anywhere - the key is the content.  (BTREE_BLOBKEY is used for SQL

  14435. ** indices.)

  14436. */

  14437. #define BTREE_INTKEY     1    /* Table has only 64-bit signed integer keys */

  14438. #define BTREE_BLOBKEY    2    /* Table has keys only - no data */

  14439. 

  14440. SQLITE_PRIVATE int sqlite3BtreeDropTable(Btree*, int, int*);

  14441. SQLITE_PRIVATE int sqlite3BtreeClearTable(Btree*, int, int*);

  14442. SQLITE_PRIVATE int sqlite3BtreeClearTableOfCursor(BtCursor*);

  14443. SQLITE_PRIVATE int sqlite3BtreeTripAllCursors(Btree*, int, int);

  14444. 

  14445. SQLITE_PRIVATE void sqlite3BtreeGetMeta(Btree *pBtree, int idx, u32 *pValue);

  14446. SQLITE_PRIVATE int sqlite3BtreeUpdateMeta(Btree*, int idx, u32 value);

  14447. 

  14448. SQLITE_PRIVATE int sqlite3BtreeNewDb(Btree *p);

  14449. 

  14450. /*

  14451. ** The second parameter to sqlite3BtreeGetMeta or sqlite3BtreeUpdateMeta

  14452. ** should be one of the following values. The integer values are assigned 

  14453. ** to constants so that the offset of the corresponding field in an

  14454. ** SQLite database header may be found using the following formula:

  14455. **

  14456. **   offset = 36 + (idx * 4)

  14457. **

  14458. ** For example, the free-page-count field is located at byte offset 36 of

  14459. ** the database file header. The incr-vacuum-flag field is located at

  14460. ** byte offset 64 (== 36+4*7).

  14461. **

  14462. ** The BTREE_DATA_VERSION value is not really a value stored in the header.

  14463. ** It is a read-only number computed by the pager.  But we merge it with

  14464. ** the header value access routines since its access pattern is the same.

  14465. ** Call it a "virtual meta value".

  14466. */

  14467. #define BTREE_FREE_PAGE_COUNT     0

  14468. #define BTREE_SCHEMA_VERSION      1

  14469. #define BTREE_FILE_FORMAT         2

  14470. #define BTREE_DEFAULT_CACHE_SIZE  3

  14471. #define BTREE_LARGEST_ROOT_PAGE   4

  14472. #define BTREE_TEXT_ENCODING       5

  14473. #define BTREE_USER_VERSION        6

  14474. #define BTREE_INCR_VACUUM         7

  14475. #define BTREE_APPLICATION_ID      8

  14476. #define BTREE_DATA_VERSION        15  /* A virtual meta-value */

  14477. 

  14478. /*

  14479. ** Kinds of hints that can be passed into the sqlite3BtreeCursorHint()

  14480. ** interface.

  14481. **

  14482. ** BTREE_HINT_RANGE  (arguments: Expr*, Mem*)

  14483. **

  14484. **     The first argument is an Expr* (which is guaranteed to be constant for

  14485. **     the lifetime of the cursor) that defines constraints on which rows

  14486. **     might be fetched with this cursor.  The Expr* tree may contain

  14487. **     TK_REGISTER nodes that refer to values stored in the array of registers

  14488. **     passed as the second parameter.  In other words, if Expr.op==TK_REGISTER

  14489. **     then the value of the node is the value in Mem[pExpr.iTable].  Any

  14490. **     TK_COLUMN node in the expression tree refers to the Expr.iColumn-th

  14491. **     column of the b-tree of the cursor.  The Expr tree will not contain

  14492. **     any function calls nor subqueries nor references to b-trees other than

  14493. **     the cursor being hinted.

  14494. **

  14495. **     The design of the _RANGE hint is aid b-tree implementations that try

  14496. **     to prefetch content from remote machines - to provide those

  14497. **     implementations with limits on what needs to be prefetched and thereby

  14498. **     reduce network bandwidth.

  14499. **

  14500. ** Note that BTREE_HINT_FLAGS with BTREE_BULKLOAD is the only hint used by

  14501. ** standard SQLite.  The other hints are provided for extentions that use

  14502. ** the SQLite parser and code generator but substitute their own storage

  14503. ** engine.

  14504. */

  14505. #define BTREE_HINT_RANGE 0       /* Range constraints on queries */

  14506. 

  14507. /*

  14508. ** Values that may be OR'd together to form the argument to the

  14509. ** BTREE_HINT_FLAGS hint for sqlite3BtreeCursorHint():

  14510. **

  14511. ** The BTREE_BULKLOAD flag is set on index cursors when the index is going

  14512. ** to be filled with content that is already in sorted order.

  14513. **

  14514. ** The BTREE_SEEK_EQ flag is set on cursors that will get OP_SeekGE or

  14515. ** OP_SeekLE opcodes for a range search, but where the range of entries

  14516. ** selected will all have the same key.  In other words, the cursor will

  14517. ** be used only for equality key searches.

  14518. **

  14519. */

  14520. #define BTREE_BULKLOAD 0x00000001  /* Used to full index in sorted order */

  14521. #define BTREE_SEEK_EQ  0x00000002  /* EQ seeks only - no range seeks */

  14522. 

  14523. /* 

  14524. ** Flags passed as the third argument to sqlite3BtreeCursor().

  14525. **

  14526. ** For read-only cursors the wrFlag argument is always zero. For read-write

  14527. ** cursors it may be set to either (BTREE_WRCSR|BTREE_FORDELETE) or just

  14528. ** (BTREE_WRCSR). If the BTREE_FORDELETE bit is set, then the cursor will

  14529. ** only be used by SQLite for the following:

  14530. **

  14531. **   * to seek to and then delete specific entries, and/or

  14532. **

  14533. **   * to read values that will be used to create keys that other

  14534. **     BTREE_FORDELETE cursors will seek to and delete.

  14535. **

  14536. ** The BTREE_FORDELETE flag is an optimization hint.  It is not used by

  14537. ** by this, the native b-tree engine of SQLite, but it is available to

  14538. ** alternative storage engines that might be substituted in place of this

  14539. ** b-tree system.  For alternative storage engines in which a delete of

  14540. ** the main table row automatically deletes corresponding index rows,

  14541. ** the FORDELETE flag hint allows those alternative storage engines to

  14542. ** skip a lot of work.  Namely:  FORDELETE cursors may treat all SEEK

  14543. ** and DELETE operations as no-ops, and any READ operation against a

  14544. ** FORDELETE cursor may return a null row: 0x01 0x00.

  14545. */

  14546. #define BTREE_WRCSR     0x00000004     /* read-write cursor */

  14547. #define BTREE_FORDELETE 0x00000008     /* Cursor is for seek/delete only */

  14548. 

  14549. SQLITE_PRIVATE int sqlite3BtreeCursor(

  14550.   Btree*,                              /* BTree containing table to open */

  14551.   int iTable,                          /* Index of root page */

  14552.   int wrFlag,                          /* 1 for writing.  0 for read-only */

  14553.   struct KeyInfo*,                     /* First argument to compare function */

  14554.   BtCursor *pCursor                    /* Space to write cursor structure */

  14555. );

  14556. SQLITE_PRIVATE BtCursor *sqlite3BtreeFakeValidCursor(void);

  14557. SQLITE_PRIVATE int sqlite3BtreeCursorSize(void);

  14558. SQLITE_PRIVATE void sqlite3BtreeCursorZero(BtCursor*);

  14559. SQLITE_PRIVATE void sqlite3BtreeCursorHintFlags(BtCursor*, unsigned);

  14560. #ifdef SQLITE_ENABLE_CURSOR_HINTS

  14561. SQLITE_PRIVATE void sqlite3BtreeCursorHint(BtCursor*, int, ...);

  14562. #endif

  14563. 

  14564. SQLITE_PRIVATE int sqlite3BtreeCloseCursor(BtCursor*);

  14565. SQLITE_PRIVATE int sqlite3BtreeMovetoUnpacked(

  14566.   BtCursor*,

  14567.   UnpackedRecord *pUnKey,

  14568.   i64 intKey,

  14569.   int bias,

  14570.   int *pRes

  14571. );

  14572. SQLITE_PRIVATE int sqlite3BtreeCursorHasMoved(BtCursor*);

  14573. SQLITE_PRIVATE int sqlite3BtreeCursorRestore(BtCursor*, int*);

  14574. SQLITE_PRIVATE int sqlite3BtreeDelete(BtCursor*, u8 flags);

  14575. 

  14576. /* Allowed flags for sqlite3BtreeDelete() and sqlite3BtreeInsert() */

  14577. #define BTREE_SAVEPOSITION 0x02  /* Leave cursor pointing at NEXT or PREV */

  14578. #define BTREE_AUXDELETE    0x04  /* not the primary delete operation */

  14579. #define BTREE_APPEND       0x08  /* Insert is likely an append */

  14580. 

  14581. /* An instance of the BtreePayload object describes the content of a single

  14582. ** entry in either an index or table btree.

  14583. **

  14584. ** Index btrees (used for indexes and also WITHOUT ROWID tables) contain

  14585. ** an arbitrary key and no data.  These btrees have pKey,nKey set to the

  14586. ** key and the pData,nData,nZero fields are uninitialized.  The aMem,nMem

  14587. ** fields give an array of Mem objects that are a decomposition of the key.

  14588. ** The nMem field might be zero, indicating that no decomposition is available.

  14589. **

  14590. ** Table btrees (used for rowid tables) contain an integer rowid used as

  14591. ** the key and passed in the nKey field.  The pKey field is zero.  

  14592. ** pData,nData hold the content of the new entry.  nZero extra zero bytes

  14593. ** are appended to the end of the content when constructing the entry.

  14594. ** The aMem,nMem fields are uninitialized for table btrees.

  14595. **

  14596. ** Field usage summary:

  14597. **

  14598. **               Table BTrees                   Index Btrees

  14599. **

  14600. **   pKey        always NULL                    encoded key

  14601. **   nKey        the ROWID                      length of pKey

  14602. **   pData       data                           not used

  14603. **   aMem        not used                       decomposed key value

  14604. **   nMem        not used                       entries in aMem

  14605. **   nData       length of pData                not used

  14606. **   nZero       extra zeros after pData        not used

  14607. **

  14608. ** This object is used to pass information into sqlite3BtreeInsert().  The

  14609. ** same information used to be passed as five separate parameters.  But placing

  14610. ** the information into this object helps to keep the interface more 

  14611. ** organized and understandable, and it also helps the resulting code to

  14612. ** run a little faster by using fewer registers for parameter passing.

  14613. */

  14614. struct BtreePayload {

  14615.   const void *pKey;       /* Key content for indexes.  NULL for tables */

  14616.   sqlite3_int64 nKey;     /* Size of pKey for indexes.  PRIMARY KEY for tabs */

  14617.   const void *pData;      /* Data for tables. */

  14618.   sqlite3_value *aMem;    /* First of nMem value in the unpacked pKey */

  14619.   u16 nMem;               /* Number of aMem[] value.  Might be zero */

  14620.   int nData;              /* Size of pData.  0 if none. */

  14621.   int nZero;              /* Extra zero data appended after pData,nData */

  14622. };

  14623. 

  14624. SQLITE_PRIVATE int sqlite3BtreeInsert(BtCursor*, const BtreePayload *pPayload,

  14625.                        int flags, int seekResult);

  14626. SQLITE_PRIVATE int sqlite3BtreeFirst(BtCursor*, int *pRes);

  14627. SQLITE_PRIVATE int sqlite3BtreeLast(BtCursor*, int *pRes);

  14628. SQLITE_PRIVATE int sqlite3BtreeNext(BtCursor*, int flags);

  14629. SQLITE_PRIVATE int sqlite3BtreeEof(BtCursor*);

  14630. SQLITE_PRIVATE int sqlite3BtreePrevious(BtCursor*, int flags);

  14631. SQLITE_PRIVATE i64 sqlite3BtreeIntegerKey(BtCursor*);

  14632. #ifdef SQLITE_ENABLE_OFFSET_SQL_FUNC

  14633. SQLITE_PRIVATE i64 sqlite3BtreeOffset(BtCursor*);

  14634. #endif

  14635. SQLITE_PRIVATE int sqlite3BtreePayload(BtCursor*, u32 offset, u32 amt, void*);

  14636. SQLITE_PRIVATE const void *sqlite3BtreePayloadFetch(BtCursor*, u32 *pAmt);

  14637. SQLITE_PRIVATE u32 sqlite3BtreePayloadSize(BtCursor*);

  14638. SQLITE_PRIVATE sqlite3_int64 sqlite3BtreeMaxRecordSize(BtCursor*);

  14639. 

  14640. SQLITE_PRIVATE char *sqlite3BtreeIntegrityCheck(Btree*, int *aRoot, int nRoot, int, int*);

  14641. SQLITE_PRIVATE struct Pager *sqlite3BtreePager(Btree*);

  14642. SQLITE_PRIVATE i64 sqlite3BtreeRowCountEst(BtCursor*);

  14643. 

  14644. #ifndef SQLITE_OMIT_INCRBLOB

  14645. SQLITE_PRIVATE int sqlite3BtreePayloadChecked(BtCursor*, u32 offset, u32 amt, void*);

  14646. SQLITE_PRIVATE int sqlite3BtreePutData(BtCursor*, u32 offset, u32 amt, void*);

  14647. SQLITE_PRIVATE void sqlite3BtreeIncrblobCursor(BtCursor *);

  14648. #endif

  14649. SQLITE_PRIVATE void sqlite3BtreeClearCursor(BtCursor *);

  14650. SQLITE_PRIVATE int sqlite3BtreeSetVersion(Btree *pBt, int iVersion);

  14651. SQLITE_PRIVATE int sqlite3BtreeCursorHasHint(BtCursor*, unsigned int mask);

  14652. SQLITE_PRIVATE int sqlite3BtreeIsReadonly(Btree *pBt);

  14653. SQLITE_PRIVATE int sqlite3HeaderSizeBtree(void);

  14654. 

  14655. #ifndef NDEBUG

  14656. SQLITE_PRIVATE int sqlite3BtreeCursorIsValid(BtCursor*);

  14657. #endif

  14658. SQLITE_PRIVATE int sqlite3BtreeCursorIsValidNN(BtCursor*);

  14659. 

  14660. #ifndef SQLITE_OMIT_BTREECOUNT

  14661. SQLITE_PRIVATE int sqlite3BtreeCount(BtCursor *, i64 *);

  14662. #endif

  14663. 

  14664. #ifdef SQLITE_TEST

  14665. SQLITE_PRIVATE int sqlite3BtreeCursorInfo(BtCursor*, int*, int);

  14666. SQLITE_PRIVATE void sqlite3BtreeCursorList(Btree*);

  14667. #endif

  14668. 

  14669. #ifndef SQLITE_OMIT_WAL

  14670. SQLITE_PRIVATE   int sqlite3BtreeCheckpoint(Btree*, int, int *, int *);

  14671. #endif

  14672. 

  14673. /*

  14674. ** If we are not using shared cache, then there is no need to

  14675. ** use mutexes to access the BtShared structures.  So make the

  14676. ** Enter and Leave procedures no-ops.

  14677. */

  14678. #ifndef SQLITE_OMIT_SHARED_CACHE

  14679. SQLITE_PRIVATE   void sqlite3BtreeEnter(Btree*);

  14680. SQLITE_PRIVATE   void sqlite3BtreeEnterAll(sqlite3*);

  14681. SQLITE_PRIVATE   int sqlite3BtreeSharable(Btree*);

  14682. SQLITE_PRIVATE   void sqlite3BtreeEnterCursor(BtCursor*);

  14683. SQLITE_PRIVATE   int sqlite3BtreeConnectionCount(Btree*);

  14684. #else

  14685. # define sqlite3BtreeEnter(X) 

  14686. # define sqlite3BtreeEnterAll(X)

  14687. # define sqlite3BtreeSharable(X) 0

  14688. # define sqlite3BtreeEnterCursor(X)

  14689. # define sqlite3BtreeConnectionCount(X) 1

  14690. #endif

  14691. 

  14692. #if !defined(SQLITE_OMIT_SHARED_CACHE) && SQLITE_THREADSAFE

  14693. SQLITE_PRIVATE   void sqlite3BtreeLeave(Btree*);

  14694. SQLITE_PRIVATE   void sqlite3BtreeLeaveCursor(BtCursor*);

  14695. SQLITE_PRIVATE   void sqlite3BtreeLeaveAll(sqlite3*);

  14696. #ifndef NDEBUG

  14697.   /* These routines are used inside assert() statements only. */

  14698. SQLITE_PRIVATE   int sqlite3BtreeHoldsMutex(Btree*);

  14699. SQLITE_PRIVATE   int sqlite3BtreeHoldsAllMutexes(sqlite3*);

  14700. SQLITE_PRIVATE   int sqlite3SchemaMutexHeld(sqlite3*,int,Schema*);

  14701. #endif

  14702. #else

  14703. 

  14704. # define sqlite3BtreeLeave(X)

  14705. # define sqlite3BtreeLeaveCursor(X)

  14706. # define sqlite3BtreeLeaveAll(X)

  14707. 

  14708. # define sqlite3BtreeHoldsMutex(X) 1

  14709. # define sqlite3BtreeHoldsAllMutexes(X) 1

  14710. # define sqlite3SchemaMutexHeld(X,Y,Z) 1

  14711. #endif

  14712. 

  14713. 

  14714. #endif /* SQLITE_BTREE_H */

  14715. 

  14716. /************** End of btree.h ***********************************************/

  14717. /************** Continuing where we left off in sqliteInt.h ******************/

  14718. /************** Include vdbe.h in the middle of sqliteInt.h ******************/

  14719. /************** Begin file vdbe.h ********************************************/

  14720. /*

  14721. ** 2001 September 15

  14722. **

  14723. ** The author disclaims copyright to this source code.  In place of

  14724. ** a legal notice, here is a blessing:

  14725. **

  14726. **    May you do good and not evil.

  14727. **    May you find forgiveness for yourself and forgive others.

  14728. **    May you share freely, never taking more than you give.

  14729. **

  14730. *************************************************************************

  14731. ** Header file for the Virtual DataBase Engine (VDBE)

  14732. **

  14733. ** This header defines the interface to the virtual database engine

  14734. ** or VDBE.  The VDBE implements an abstract machine that runs a

  14735. ** simple program to access and modify the underlying database.

  14736. */

  14737. #ifndef SQLITE_VDBE_H

  14738. #define SQLITE_VDBE_H

  14739. /* #include <stdio.h> */

  14740. 

  14741. /*

  14742. ** A single VDBE is an opaque structure named "Vdbe".  Only routines

  14743. ** in the source file sqliteVdbe.c are allowed to see the insides

  14744. ** of this structure.

  14745. */

  14746. typedef struct Vdbe Vdbe;

  14747. 

  14748. /*

  14749. ** The names of the following types declared in vdbeInt.h are required

  14750. ** for the VdbeOp definition.

  14751. */

  14752. typedef struct sqlite3_value Mem;

  14753. typedef struct SubProgram SubProgram;

  14754. 

  14755. /*

  14756. ** A single instruction of the virtual machine has an opcode

  14757. ** and as many as three operands.  The instruction is recorded

  14758. ** as an instance of the following structure:

  14759. */

  14760. struct VdbeOp {

  14761.   u8 opcode;          /* What operation to perform */

  14762.   signed char p4type; /* One of the P4_xxx constants for p4 */

  14763.   u16 p5;             /* Fifth parameter is an unsigned 16-bit integer */

  14764.   int p1;             /* First operand */

  14765.   int p2;             /* Second parameter (often the jump destination) */

  14766.   int p3;             /* The third parameter */

  14767.   union p4union {     /* fourth parameter */

  14768.     int i;                 /* Integer value if p4type==P4_INT32 */

  14769.     void *p;               /* Generic pointer */

  14770.     char *z;               /* Pointer to data for string (char array) types */

  14771.     i64 *pI64;             /* Used when p4type is P4_INT64 */

  14772.     double *pReal;         /* Used when p4type is P4_REAL */

  14773.     FuncDef *pFunc;        /* Used when p4type is P4_FUNCDEF */

  14774.     sqlite3_context *pCtx; /* Used when p4type is P4_FUNCCTX */

  14775.     CollSeq *pColl;        /* Used when p4type is P4_COLLSEQ */

  14776.     Mem *pMem;             /* Used when p4type is P4_MEM */

  14777.     VTable *pVtab;         /* Used when p4type is P4_VTAB */

  14778.     KeyInfo *pKeyInfo;     /* Used when p4type is P4_KEYINFO */

  14779.     int *ai;               /* Used when p4type is P4_INTARRAY */

  14780.     SubProgram *pProgram;  /* Used when p4type is P4_SUBPROGRAM */

  14781.     Table *pTab;           /* Used when p4type is P4_TABLE */

  14782. #ifdef SQLITE_ENABLE_CURSOR_HINTS

  14783.     Expr *pExpr;           /* Used when p4type is P4_EXPR */

  14784. #endif

  14785.     int (*xAdvance)(BtCursor *, int);

  14786.   } p4;

  14787. #ifdef SQLITE_ENABLE_EXPLAIN_COMMENTS

  14788.   char *zComment;          /* Comment to improve readability */

  14789. #endif

  14790. #ifdef VDBE_PROFILE

  14791.   u32 cnt;                 /* Number of times this instruction was executed */

  14792.   u64 cycles;              /* Total time spent executing this instruction */

  14793. #endif

  14794. #ifdef SQLITE_VDBE_COVERAGE

  14795.   u32 iSrcLine;            /* Source-code line that generated this opcode

  14796.                            ** with flags in the upper 8 bits */

  14797. #endif

  14798. };

  14799. typedef struct VdbeOp VdbeOp;

  14800. 

  14801. 

  14802. /*

  14803. ** A sub-routine used to implement a trigger program.

  14804. */

  14805. struct SubProgram {

  14806.   VdbeOp *aOp;                  /* Array of opcodes for sub-program */

  14807.   int nOp;                      /* Elements in aOp[] */

  14808.   int nMem;                     /* Number of memory cells required */

  14809.   int nCsr;                     /* Number of cursors required */

  14810.   u8 *aOnce;                    /* Array of OP_Once flags */

  14811.   void *token;                  /* id that may be used to recursive triggers */

  14812.   SubProgram *pNext;            /* Next sub-program already visited */

  14813. };

  14814. 

  14815. /*

  14816. ** A smaller version of VdbeOp used for the VdbeAddOpList() function because

  14817. ** it takes up less space.

  14818. */

  14819. struct VdbeOpList {

  14820.   u8 opcode;          /* What operation to perform */

  14821.   signed char p1;     /* First operand */

  14822.   signed char p2;     /* Second parameter (often the jump destination) */

  14823.   signed char p3;     /* Third parameter */

  14824. };

  14825. typedef struct VdbeOpList VdbeOpList;

  14826. 

  14827. /*

  14828. ** Allowed values of VdbeOp.p4type

  14829. */

  14830. #define P4_NOTUSED      0   /* The P4 parameter is not used */

  14831. #define P4_TRANSIENT    0   /* P4 is a pointer to a transient string */

  14832. #define P4_STATIC     (-1)  /* Pointer to a static string */

  14833. #define P4_COLLSEQ    (-2)  /* P4 is a pointer to a CollSeq structure */

  14834. #define P4_INT32      (-3)  /* P4 is a 32-bit signed integer */

  14835. #define P4_SUBPROGRAM (-4)  /* P4 is a pointer to a SubProgram structure */

  14836. #define P4_ADVANCE    (-5)  /* P4 is a pointer to BtreeNext() or BtreePrev() */

  14837. #define P4_TABLE      (-6)  /* P4 is a pointer to a Table structure */

  14838. /* Above do not own any resources.  Must free those below */

  14839. #define P4_FREE_IF_LE (-7)

  14840. #define P4_DYNAMIC    (-7)  /* Pointer to memory from sqliteMalloc() */

  14841. #define P4_FUNCDEF    (-8)  /* P4 is a pointer to a FuncDef structure */

  14842. #define P4_KEYINFO    (-9)  /* P4 is a pointer to a KeyInfo structure */

  14843. #define P4_EXPR       (-10) /* P4 is a pointer to an Expr tree */

  14844. #define P4_MEM        (-11) /* P4 is a pointer to a Mem*    structure */

  14845. #define P4_VTAB       (-12) /* P4 is a pointer to an sqlite3_vtab structure */

  14846. #define P4_REAL       (-13) /* P4 is a 64-bit floating point value */

  14847. #define P4_INT64      (-14) /* P4 is a 64-bit signed integer */

  14848. #define P4_INTARRAY   (-15) /* P4 is a vector of 32-bit integers */

  14849. #define P4_FUNCCTX    (-16) /* P4 is a pointer to an sqlite3_context object */

  14850. #define P4_DYNBLOB    (-17) /* Pointer to memory from sqliteMalloc() */

  14851. 

  14852. /* Error message codes for OP_Halt */

  14853. #define P5_ConstraintNotNull 1

  14854. #define P5_ConstraintUnique  2

  14855. #define P5_ConstraintCheck   3

  14856. #define P5_ConstraintFK      4

  14857. 

  14858. /*

  14859. ** The Vdbe.aColName array contains 5n Mem structures, where n is the 

  14860. ** number of columns of data returned by the statement.

  14861. */

  14862. #define COLNAME_NAME     0

  14863. #define COLNAME_DECLTYPE 1

  14864. #define COLNAME_DATABASE 2

  14865. #define COLNAME_TABLE    3

  14866. #define COLNAME_COLUMN   4

  14867. #ifdef SQLITE_ENABLE_COLUMN_METADATA

  14868. # define COLNAME_N        5      /* Number of COLNAME_xxx symbols */

  14869. #else

  14870. # ifdef SQLITE_OMIT_DECLTYPE

  14871. #   define COLNAME_N      1      /* Store only the name */

  14872. # else

  14873. #   define COLNAME_N      2      /* Store the name and decltype */

  14874. # endif

  14875. #endif

  14876. 

  14877. /*

  14878. ** The following macro converts a label returned by sqlite3VdbeMakeLabel()

  14879. ** into an index into the Parse.aLabel[] array that contains the resolved

  14880. ** address of that label.

  14881. */

  14882. #define ADDR(X)  (~(X))

  14883. 

  14884. /*

  14885. ** The makefile scans the vdbe.c source file and creates the "opcodes.h"

  14886. ** header file that defines a number for each opcode used by the VDBE.

  14887. */

  14888. /************** Include opcodes.h in the middle of vdbe.h ********************/

  14889. /************** Begin file opcodes.h *****************************************/

  14890. /* Automatically generated.  Do not edit */

  14891. /* See the tool/mkopcodeh.tcl script for details */

  14892. #define OP_Savepoint       0

  14893. #define OP_AutoCommit      1

  14894. #define OP_Transaction     2

  14895. #define OP_SorterNext      3 /* jump                                       */

  14896. #define OP_Prev            4 /* jump                                       */

  14897. #define OP_Next            5 /* jump                                       */

  14898. #define OP_Checkpoint      6

  14899. #define OP_JournalMode     7

  14900. #define OP_Vacuum          8

  14901. #define OP_VFilter         9 /* jump, synopsis: iplan=r[P3] zplan='P4'     */

  14902. #define OP_VUpdate        10 /* synopsis: data=r[P3@P2]                    */

  14903. #define OP_Goto           11 /* jump                                       */

  14904. #define OP_Gosub          12 /* jump                                       */

  14905. #define OP_InitCoroutine  13 /* jump                                       */

  14906. #define OP_Yield          14 /* jump                                       */

  14907. #define OP_MustBeInt      15 /* jump                                       */

  14908. #define OP_Jump           16 /* jump                                       */

  14909. #define OP_Once           17 /* jump                                       */

  14910. #define OP_If             18 /* jump                                       */

  14911. #define OP_Not            19 /* same as TK_NOT, synopsis: r[P2]= !r[P1]    */

  14912. #define OP_IfNot          20 /* jump                                       */

  14913. #define OP_IfNullRow      21 /* jump, synopsis: if P1.nullRow then r[P3]=NULL, goto P2 */

  14914. #define OP_SeekLT         22 /* jump, synopsis: key=r[P3@P4]               */

  14915. #define OP_SeekLE         23 /* jump, synopsis: key=r[P3@P4]               */

  14916. #define OP_SeekGE         24 /* jump, synopsis: key=r[P3@P4]               */

  14917. #define OP_SeekGT         25 /* jump, synopsis: key=r[P3@P4]               */

  14918. #define OP_IfNoHope       26 /* jump, synopsis: key=r[P3@P4]               */

  14919. #define OP_NoConflict     27 /* jump, synopsis: key=r[P3@P4]               */

  14920. #define OP_NotFound       28 /* jump, synopsis: key=r[P3@P4]               */

  14921. #define OP_Found          29 /* jump, synopsis: key=r[P3@P4]               */

  14922. #define OP_SeekRowid      30 /* jump, synopsis: intkey=r[P3]               */

  14923. #define OP_NotExists      31 /* jump, synopsis: intkey=r[P3]               */

  14924. #define OP_Last           32 /* jump                                       */

  14925. #define OP_IfSmaller      33 /* jump                                       */

  14926. #define OP_SorterSort     34 /* jump                                       */

  14927. #define OP_Sort           35 /* jump                                       */

  14928. #define OP_Rewind         36 /* jump                                       */

  14929. #define OP_IdxLE          37 /* jump, synopsis: key=r[P3@P4]               */

  14930. #define OP_IdxGT          38 /* jump, synopsis: key=r[P3@P4]               */

  14931. #define OP_IdxLT          39 /* jump, synopsis: key=r[P3@P4]               */

  14932. #define OP_IdxGE          40 /* jump, synopsis: key=r[P3@P4]               */

  14933. #define OP_RowSetRead     41 /* jump, synopsis: r[P3]=rowset(P1)           */

  14934. #define OP_RowSetTest     42 /* jump, synopsis: if r[P3] in rowset(P1) goto P2 */

  14935. #define OP_Or             43 /* same as TK_OR, synopsis: r[P3]=(r[P1] || r[P2]) */

  14936. #define OP_And            44 /* same as TK_AND, synopsis: r[P3]=(r[P1] && r[P2]) */

  14937. #define OP_Program        45 /* jump                                       */

  14938. #define OP_FkIfZero       46 /* jump, synopsis: if fkctr[P1]==0 goto P2    */

  14939. #define OP_IfPos          47 /* jump, synopsis: if r[P1]>0 then r[P1]-=P3, goto P2 */

  14940. #define OP_IfNotZero      48 /* jump, synopsis: if r[P1]!=0 then r[P1]--, goto P2 */

  14941. #define OP_DecrJumpZero   49 /* jump, synopsis: if (--r[P1])==0 goto P2    */

  14942. #define OP_IsNull         50 /* jump, same as TK_ISNULL, synopsis: if r[P1]==NULL goto P2 */

  14943. #define OP_NotNull        51 /* jump, same as TK_NOTNULL, synopsis: if r[P1]!=NULL goto P2 */

  14944. #define OP_Ne             52 /* jump, same as TK_NE, synopsis: IF r[P3]!=r[P1] */

  14945. #define OP_Eq             53 /* jump, same as TK_EQ, synopsis: IF r[P3]==r[P1] */

  14946. #define OP_Gt             54 /* jump, same as TK_GT, synopsis: IF r[P3]>r[P1] */

  14947. #define OP_Le             55 /* jump, same as TK_LE, synopsis: IF r[P3]<=r[P1] */

  14948. #define OP_Lt             56 /* jump, same as TK_LT, synopsis: IF r[P3]<r[P1] */

  14949. #define OP_Ge             57 /* jump, same as TK_GE, synopsis: IF r[P3]>=r[P1] */

  14950. #define OP_ElseNotEq      58 /* jump, same as TK_ESCAPE                    */

  14951. #define OP_IncrVacuum     59 /* jump                                       */

  14952. #define OP_VNext          60 /* jump                                       */

  14953. #define OP_Init           61 /* jump, synopsis: Start at P2                */

  14954. #define OP_PureFunc0      62

  14955. #define OP_Function0      63 /* synopsis: r[P3]=func(r[P2@P5])             */

  14956. #define OP_PureFunc       64

  14957. #define OP_Function       65 /* synopsis: r[P3]=func(r[P2@P5])             */

  14958. #define OP_Return         66

  14959. #define OP_EndCoroutine   67

  14960. #define OP_HaltIfNull     68 /* synopsis: if r[P3]=null halt               */

  14961. #define OP_Halt           69

  14962. #define OP_Integer        70 /* synopsis: r[P2]=P1                         */

  14963. #define OP_Int64          71 /* synopsis: r[P2]=P4                         */

  14964. #define OP_String         72 /* synopsis: r[P2]='P4' (len=P1)              */

  14965. #define OP_Null           73 /* synopsis: r[P2..P3]=NULL                   */

  14966. #define OP_SoftNull       74 /* synopsis: r[P1]=NULL                       */

  14967. #define OP_Blob           75 /* synopsis: r[P2]=P4 (len=P1)                */

  14968. #define OP_Variable       76 /* synopsis: r[P2]=parameter(P1,P4)           */

  14969. #define OP_Move           77 /* synopsis: r[P2@P3]=r[P1@P3]                */

  14970. #define OP_Copy           78 /* synopsis: r[P2@P3+1]=r[P1@P3+1]            */

  14971. #define OP_SCopy          79 /* synopsis: r[P2]=r[P1]                      */

  14972. #define OP_IntCopy        80 /* synopsis: r[P2]=r[P1]                      */

  14973. #define OP_ResultRow      81 /* synopsis: output=r[P1@P2]                  */

  14974. #define OP_CollSeq        82

  14975. #define OP_AddImm         83 /* synopsis: r[P1]=r[P1]+P2                   */

  14976. #define OP_RealAffinity   84

  14977. #define OP_Cast           85 /* synopsis: affinity(r[P1])                  */

  14978. #define OP_Permutation    86

  14979. #define OP_Compare        87 /* synopsis: r[P1@P3] <-> r[P2@P3]            */

  14980. #define OP_IsTrue         88 /* synopsis: r[P2] = coalesce(r[P1]==TRUE,P3) ^ P4 */

  14981. #define OP_Offset         89 /* synopsis: r[P3] = sqlite_offset(P1)        */

  14982. #define OP_Column         90 /* synopsis: r[P3]=PX                         */

  14983. #define OP_Affinity       91 /* synopsis: affinity(r[P1@P2])               */

  14984. #define OP_MakeRecord     92 /* synopsis: r[P3]=mkrec(r[P1@P2])            */

  14985. #define OP_Count          93 /* synopsis: r[P2]=count()                    */

  14986. #define OP_ReadCookie     94

  14987. #define OP_SetCookie      95

  14988. #define OP_BitAnd         96 /* same as TK_BITAND, synopsis: r[P3]=r[P1]&r[P2] */

  14989. #define OP_BitOr          97 /* same as TK_BITOR, synopsis: r[P3]=r[P1]|r[P2] */

  14990. #define OP_ShiftLeft      98 /* same as TK_LSHIFT, synopsis: r[P3]=r[P2]<<r[P1] */

  14991. #define OP_ShiftRight     99 /* same as TK_RSHIFT, synopsis: r[P3]=r[P2]>>r[P1] */

  14992. #define OP_Add           100 /* same as TK_PLUS, synopsis: r[P3]=r[P1]+r[P2] */

  14993. #define OP_Subtract      101 /* same as TK_MINUS, synopsis: r[P3]=r[P2]-r[P1] */

  14994. #define OP_Multiply      102 /* same as TK_STAR, synopsis: r[P3]=r[P1]*r[P2] */

  14995. #define OP_Divide        103 /* same as TK_SLASH, synopsis: r[P3]=r[P2]/r[P1] */

  14996. #define OP_Remainder     104 /* same as TK_REM, synopsis: r[P3]=r[P2]%r[P1] */

  14997. #define OP_Concat        105 /* same as TK_CONCAT, synopsis: r[P3]=r[P2]+r[P1] */

  14998. #define OP_ReopenIdx     106 /* synopsis: root=P2 iDb=P3                   */

  14999. #define OP_BitNot        107 /* same as TK_BITNOT, synopsis: r[P2]= ~r[P1] */

  15000. #define OP_OpenRead      108 /* synopsis: root=P2 iDb=P3                   */

  15001. #define OP_OpenWrite     109 /* synopsis: root=P2 iDb=P3                   */

  15002. #define OP_String8       110 /* same as TK_STRING, synopsis: r[P2]='P4'    */

  15003. #define OP_OpenDup       111

  15004. #define OP_OpenAutoindex 112 /* synopsis: nColumn=P2                       */

  15005. #define OP_OpenEphemeral 113 /* synopsis: nColumn=P2                       */

  15006. #define OP_SorterOpen    114

  15007. #define OP_SequenceTest  115 /* synopsis: if( cursor[P1].ctr++ ) pc = P2   */

  15008. #define OP_OpenPseudo    116 /* synopsis: P3 columns in r[P2]              */

  15009. #define OP_Close         117

  15010. #define OP_ColumnsUsed   118

  15011. #define OP_SeekHit       119 /* synopsis: seekHit=P2                       */

  15012. #define OP_Sequence      120 /* synopsis: r[P2]=cursor[P1].ctr++           */

  15013. #define OP_NewRowid      121 /* synopsis: r[P2]=rowid                      */

  15014. #define OP_Insert        122 /* synopsis: intkey=r[P3] data=r[P2]          */

  15015. #define OP_Delete        123

  15016. #define OP_ResetCount    124

  15017. #define OP_SorterCompare 125 /* synopsis: if key(P1)!=trim(r[P3],P4) goto P2 */

  15018. #define OP_SorterData    126 /* synopsis: r[P2]=data                       */

  15019. #define OP_RowData       127 /* synopsis: r[P2]=data                       */

  15020. #define OP_Rowid         128 /* synopsis: r[P2]=rowid                      */

  15021. #define OP_NullRow       129

  15022. #define OP_SeekEnd       130

  15023. #define OP_SorterInsert  131 /* synopsis: key=r[P2]                        */

  15024. #define OP_IdxInsert     132 /* synopsis: key=r[P2]                        */

  15025. #define OP_IdxDelete     133 /* synopsis: key=r[P2@P3]                     */

  15026. #define OP_DeferredSeek  134 /* synopsis: Move P3 to P1.rowid if needed    */

  15027. #define OP_IdxRowid      135 /* synopsis: r[P2]=rowid                      */

  15028. #define OP_Destroy       136

  15029. #define OP_Clear         137

  15030. #define OP_ResetSorter   138

  15031. #define OP_CreateBtree   139 /* synopsis: r[P2]=root iDb=P1 flags=P3       */

  15032. #define OP_SqlExec       140

  15033. #define OP_ParseSchema   141

  15034. #define OP_LoadAnalysis  142

  15035. #define OP_DropTable     143

  15036. #define OP_DropIndex     144

  15037. #define OP_Real          145 /* same as TK_FLOAT, synopsis: r[P2]=P4       */

  15038. #define OP_DropTrigger   146

  15039. #define OP_IntegrityCk   147

  15040. #define OP_RowSetAdd     148 /* synopsis: rowset(P1)=r[P2]                 */

  15041. #define OP_Param         149

  15042. #define OP_FkCounter     150 /* synopsis: fkctr[P1]+=P2                    */

  15043. #define OP_MemMax        151 /* synopsis: r[P1]=max(r[P1],r[P2])           */

  15044. #define OP_OffsetLimit   152 /* synopsis: if r[P1]>0 then r[P2]=r[P1]+max(0,r[P3]) else r[P2]=(-1) */

  15045. #define OP_AggInverse    153 /* synopsis: accum=r[P3] inverse(r[P2@P5])    */

  15046. #define OP_AggStep       154 /* synopsis: accum=r[P3] step(r[P2@P5])       */

  15047. #define OP_AggStep1      155 /* synopsis: accum=r[P3] step(r[P2@P5])       */

  15048. #define OP_AggValue      156 /* synopsis: r[P3]=value N=P2                 */

  15049. #define OP_AggFinal      157 /* synopsis: accum=r[P1] N=P2                 */

  15050. #define OP_Expire        158

  15051. #define OP_TableLock     159 /* synopsis: iDb=P1 root=P2 write=P3          */

  15052. #define OP_VBegin        160

  15053. #define OP_VCreate       161

  15054. #define OP_VDestroy      162

  15055. #define OP_VOpen         163

  15056. #define OP_VColumn       164 /* synopsis: r[P3]=vcolumn(P2)                */

  15057. #define OP_VRename       165

  15058. #define OP_Pagecount     166

  15059. #define OP_MaxPgcnt      167

  15060. #define OP_Trace         168

  15061. #define OP_CursorHint    169

  15062. #define OP_Noop          170

  15063. #define OP_Explain       171

  15064. #define OP_Abortable     172

  15065. 

  15066. /* Properties such as "out2" or "jump" that are specified in

  15067. ** comments following the "case" for each opcode in the vdbe.c

  15068. ** are encoded into bitvectors as follows:

  15069. */

  15070. #define OPFLG_JUMP        0x01  /* jump:  P2 holds jmp target */

  15071. #define OPFLG_IN1         0x02  /* in1:   P1 is an input */

  15072. #define OPFLG_IN2         0x04  /* in2:   P2 is an input */

  15073. #define OPFLG_IN3         0x08  /* in3:   P3 is an input */

  15074. #define OPFLG_OUT2        0x10  /* out2:  P2 is an output */

  15075. #define OPFLG_OUT3        0x20  /* out3:  P3 is an output */

  15076. #define OPFLG_INITIALIZER {\

  15077. /*   0 */ 0x00, 0x00, 0x00, 0x01, 0x01, 0x01, 0x00, 0x10,\

  15078. /*   8 */ 0x00, 0x01, 0x00, 0x01, 0x01, 0x01, 0x03, 0x03,\

  15079. /*  16 */ 0x01, 0x01, 0x03, 0x12, 0x03, 0x01, 0x09, 0x09,\

  15080. /*  24 */ 0x09, 0x09, 0x09, 0x09, 0x09, 0x09, 0x09, 0x09,\

  15081. /*  32 */ 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01,\

  15082. /*  40 */ 0x01, 0x23, 0x0b, 0x26, 0x26, 0x01, 0x01, 0x03,\

  15083. /*  48 */ 0x03, 0x03, 0x03, 0x03, 0x0b, 0x0b, 0x0b, 0x0b,\

  15084. /*  56 */ 0x0b, 0x0b, 0x01, 0x01, 0x01, 0x01, 0x00, 0x00,\

  15085. /*  64 */ 0x00, 0x00, 0x02, 0x02, 0x08, 0x00, 0x10, 0x10,\

  15086. /*  72 */ 0x10, 0x10, 0x00, 0x10, 0x10, 0x00, 0x00, 0x10,\

  15087. /*  80 */ 0x10, 0x00, 0x00, 0x02, 0x02, 0x02, 0x00, 0x00,\

  15088. /*  88 */ 0x12, 0x20, 0x00, 0x00, 0x00, 0x10, 0x10, 0x00,\

  15089. /*  96 */ 0x26, 0x26, 0x26, 0x26, 0x26, 0x26, 0x26, 0x26,\

  15090. /* 104 */ 0x26, 0x26, 0x00, 0x12, 0x00, 0x00, 0x10, 0x00,\

  15091. /* 112 */ 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,\

  15092. /* 120 */ 0x10, 0x10, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,\

  15093. /* 128 */ 0x10, 0x00, 0x00, 0x04, 0x04, 0x00, 0x00, 0x10,\

  15094. /* 136 */ 0x10, 0x00, 0x00, 0x10, 0x00, 0x00, 0x00, 0x00,\

  15095. /* 144 */ 0x00, 0x10, 0x00, 0x00, 0x06, 0x10, 0x00, 0x04,\

  15096. /* 152 */ 0x1a, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,\

  15097. /* 160 */ 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x10, 0x10,\

  15098. /* 168 */ 0x00, 0x00, 0x00, 0x00, 0x00,}

  15099. 

  15100. /* The sqlite3P2Values() routine is able to run faster if it knows

  15101. ** the value of the largest JUMP opcode.  The smaller the maximum

  15102. ** JUMP opcode the better, so the mkopcodeh.tcl script that

  15103. ** generated this include file strives to group all JUMP opcodes

  15104. ** together near the beginning of the list.

  15105. */

  15106. #define SQLITE_MX_JUMP_OPCODE  61  /* Maximum JUMP opcode */

  15107. 

  15108. /************** End of opcodes.h *********************************************/

  15109. /************** Continuing where we left off in vdbe.h ***********************/

  15110. 

  15111. /*

  15112. ** Additional non-public SQLITE_PREPARE_* flags

  15113. */

  15114. #define SQLITE_PREPARE_SAVESQL  0x80  /* Preserve SQL text */

  15115. #define SQLITE_PREPARE_MASK     0x0f  /* Mask of public flags */

  15116. 

  15117. /*

  15118. ** Prototypes for the VDBE interface.  See comments on the implementation

  15119. ** for a description of what each of these routines does.

  15120. */

  15121. SQLITE_PRIVATE Vdbe *sqlite3VdbeCreate(Parse*);

  15122. SQLITE_PRIVATE int sqlite3VdbeAddOp0(Vdbe*,int);

  15123. SQLITE_PRIVATE int sqlite3VdbeAddOp1(Vdbe*,int,int);

  15124. SQLITE_PRIVATE int sqlite3VdbeAddOp2(Vdbe*,int,int,int);

  15125. SQLITE_PRIVATE int sqlite3VdbeGoto(Vdbe*,int);

  15126. SQLITE_PRIVATE int sqlite3VdbeLoadString(Vdbe*,int,const char*);

  15127. SQLITE_PRIVATE void sqlite3VdbeMultiLoad(Vdbe*,int,const char*,...);

  15128. SQLITE_PRIVATE int sqlite3VdbeAddOp3(Vdbe*,int,int,int,int);

  15129. SQLITE_PRIVATE int sqlite3VdbeAddOp4(Vdbe*,int,int,int,int,const char *zP4,int);

  15130. SQLITE_PRIVATE int sqlite3VdbeAddOp4Dup8(Vdbe*,int,int,int,int,const u8*,int);

  15131. SQLITE_PRIVATE int sqlite3VdbeAddOp4Int(Vdbe*,int,int,int,int,int);

  15132. SQLITE_PRIVATE void sqlite3VdbeEndCoroutine(Vdbe*,int);

  15133. #if defined(SQLITE_DEBUG) && !defined(SQLITE_TEST_REALLOC_STRESS)

  15134. SQLITE_PRIVATE   void sqlite3VdbeVerifyNoMallocRequired(Vdbe *p, int N);

  15135. SQLITE_PRIVATE   void sqlite3VdbeVerifyNoResultRow(Vdbe *p);

  15136. #else

  15137. # define sqlite3VdbeVerifyNoMallocRequired(A,B)

  15138. # define sqlite3VdbeVerifyNoResultRow(A)

  15139. #endif

  15140. #if defined(SQLITE_DEBUG)

  15141. SQLITE_PRIVATE   void sqlite3VdbeVerifyAbortable(Vdbe *p, int);

  15142. #else

  15143. # define sqlite3VdbeVerifyAbortable(A,B)

  15144. #endif

  15145. SQLITE_PRIVATE VdbeOp *sqlite3VdbeAddOpList(Vdbe*, int nOp, VdbeOpList const *aOp,int iLineno);

  15146. #ifndef SQLITE_OMIT_EXPLAIN

  15147. SQLITE_PRIVATE   void sqlite3VdbeExplain(Parse*,u8,const char*,...);

  15148. SQLITE_PRIVATE   void sqlite3VdbeExplainPop(Parse*);

  15149. SQLITE_PRIVATE   int sqlite3VdbeExplainParent(Parse*);

  15150. # define ExplainQueryPlan(P)        sqlite3VdbeExplain P

  15151. # define ExplainQueryPlanPop(P)     sqlite3VdbeExplainPop(P)

  15152. # define ExplainQueryPlanParent(P)  sqlite3VdbeExplainParent(P)

  15153. #else

  15154. # define ExplainQueryPlan(P)

  15155. # define ExplainQueryPlanPop(P)

  15156. # define ExplainQueryPlanParent(P) 0

  15157. # define sqlite3ExplainBreakpoint(A,B) /*no-op*/

  15158. #endif

  15159. #if defined(SQLITE_DEBUG) && !defined(SQLITE_OMIT_EXPLAIN)

  15160. SQLITE_PRIVATE   void sqlite3ExplainBreakpoint(const char*,const char*);

  15161. #else

  15162. # define sqlite3ExplainBreakpoint(A,B) /*no-op*/

  15163. #endif

  15164. SQLITE_PRIVATE void sqlite3VdbeAddParseSchemaOp(Vdbe*,int,char*);

  15165. SQLITE_PRIVATE void sqlite3VdbeChangeOpcode(Vdbe*, u32 addr, u8);

  15166. SQLITE_PRIVATE void sqlite3VdbeChangeP1(Vdbe*, u32 addr, int P1);

  15167. SQLITE_PRIVATE void sqlite3VdbeChangeP2(Vdbe*, u32 addr, int P2);

  15168. SQLITE_PRIVATE void sqlite3VdbeChangeP3(Vdbe*, u32 addr, int P3);

  15169. SQLITE_PRIVATE void sqlite3VdbeChangeP5(Vdbe*, u16 P5);

  15170. SQLITE_PRIVATE void sqlite3VdbeJumpHere(Vdbe*, int addr);

  15171. SQLITE_PRIVATE int sqlite3VdbeChangeToNoop(Vdbe*, int addr);

  15172. SQLITE_PRIVATE int sqlite3VdbeDeletePriorOpcode(Vdbe*, u8 op);

  15173. SQLITE_PRIVATE void sqlite3VdbeChangeP4(Vdbe*, int addr, const char *zP4, int N);

  15174. SQLITE_PRIVATE void sqlite3VdbeAppendP4(Vdbe*, void *pP4, int p4type);

  15175. SQLITE_PRIVATE void sqlite3VdbeSetP4KeyInfo(Parse*, Index*);

  15176. SQLITE_PRIVATE void sqlite3VdbeUsesBtree(Vdbe*, int);

  15177. SQLITE_PRIVATE VdbeOp *sqlite3VdbeGetOp(Vdbe*, int);

  15178. SQLITE_PRIVATE int sqlite3VdbeMakeLabel(Parse*);

  15179. SQLITE_PRIVATE void sqlite3VdbeRunOnlyOnce(Vdbe*);

  15180. SQLITE_PRIVATE void sqlite3VdbeReusable(Vdbe*);

  15181. SQLITE_PRIVATE void sqlite3VdbeDelete(Vdbe*);

  15182. SQLITE_PRIVATE void sqlite3VdbeClearObject(sqlite3*,Vdbe*);

  15183. SQLITE_PRIVATE void sqlite3VdbeMakeReady(Vdbe*,Parse*);

  15184. SQLITE_PRIVATE int sqlite3VdbeFinalize(Vdbe*);

  15185. SQLITE_PRIVATE void sqlite3VdbeResolveLabel(Vdbe*, int);

  15186. SQLITE_PRIVATE int sqlite3VdbeCurrentAddr(Vdbe*);

  15187. #ifdef SQLITE_DEBUG

  15188. SQLITE_PRIVATE   int sqlite3VdbeAssertMayAbort(Vdbe *, int);

  15189. #endif

  15190. SQLITE_PRIVATE void sqlite3VdbeResetStepResult(Vdbe*);

  15191. SQLITE_PRIVATE void sqlite3VdbeRewind(Vdbe*);

  15192. SQLITE_PRIVATE int sqlite3VdbeReset(Vdbe*);

  15193. SQLITE_PRIVATE void sqlite3VdbeSetNumCols(Vdbe*,int);

  15194. SQLITE_PRIVATE int sqlite3VdbeSetColName(Vdbe*, int, int, const char *, void(*)(void*));

  15195. SQLITE_PRIVATE void sqlite3VdbeCountChanges(Vdbe*);

  15196. SQLITE_PRIVATE sqlite3 *sqlite3VdbeDb(Vdbe*);

  15197. SQLITE_PRIVATE u8 sqlite3VdbePrepareFlags(Vdbe*);

  15198. SQLITE_PRIVATE void sqlite3VdbeSetSql(Vdbe*, const char *z, int n, u8);

  15199. #ifdef SQLITE_ENABLE_NORMALIZE

  15200. SQLITE_PRIVATE void sqlite3VdbeAddDblquoteStr(sqlite3*,Vdbe*,const char*);

  15201. SQLITE_PRIVATE int sqlite3VdbeUsesDoubleQuotedString(Vdbe*,const char*);

  15202. #endif

  15203. SQLITE_PRIVATE void sqlite3VdbeSwap(Vdbe*,Vdbe*);

  15204. SQLITE_PRIVATE VdbeOp *sqlite3VdbeTakeOpArray(Vdbe*, int*, int*);

  15205. SQLITE_PRIVATE sqlite3_value *sqlite3VdbeGetBoundValue(Vdbe*, int, u8);

  15206. SQLITE_PRIVATE void sqlite3VdbeSetVarmask(Vdbe*, int);

  15207. #ifndef SQLITE_OMIT_TRACE

  15208. SQLITE_PRIVATE   char *sqlite3VdbeExpandSql(Vdbe*, const char*);

  15209. #endif

  15210. SQLITE_PRIVATE int sqlite3MemCompare(const Mem*, const Mem*, const CollSeq*);

  15211. SQLITE_PRIVATE int sqlite3BlobCompare(const Mem*, const Mem*);

  15212. 

  15213. SQLITE_PRIVATE void sqlite3VdbeRecordUnpack(KeyInfo*,int,const void*,UnpackedRecord*);

  15214. SQLITE_PRIVATE int sqlite3VdbeRecordCompare(int,const void*,UnpackedRecord*);

  15215. SQLITE_PRIVATE int sqlite3VdbeRecordCompareWithSkip(int, const void *, UnpackedRecord *, int);

  15216. SQLITE_PRIVATE UnpackedRecord *sqlite3VdbeAllocUnpackedRecord(KeyInfo*);

  15217. 

  15218. typedef int (*RecordCompare)(int,const void*,UnpackedRecord*);

  15219. SQLITE_PRIVATE RecordCompare sqlite3VdbeFindCompare(UnpackedRecord*);

  15220. 

  15221. #ifndef SQLITE_OMIT_TRIGGER

  15222. SQLITE_PRIVATE void sqlite3VdbeLinkSubProgram(Vdbe *, SubProgram *);

  15223. #endif

  15224. 

  15225. SQLITE_PRIVATE int sqlite3NotPureFunc(sqlite3_context*);

  15226. 

  15227. /* Use SQLITE_ENABLE_COMMENTS to enable generation of extra comments on

  15228. ** each VDBE opcode.

  15229. **

  15230. ** Use the SQLITE_ENABLE_MODULE_COMMENTS macro to see some extra no-op

  15231. ** comments in VDBE programs that show key decision points in the code

  15232. ** generator.

  15233. */

  15234. #ifdef SQLITE_ENABLE_EXPLAIN_COMMENTS

  15235. SQLITE_PRIVATE   void sqlite3VdbeComment(Vdbe*, const char*, ...);

  15236. # define VdbeComment(X)  sqlite3VdbeComment X

  15237. SQLITE_PRIVATE   void sqlite3VdbeNoopComment(Vdbe*, const char*, ...);

  15238. # define VdbeNoopComment(X)  sqlite3VdbeNoopComment X

  15239. # ifdef SQLITE_ENABLE_MODULE_COMMENTS

  15240. #   define VdbeModuleComment(X)  sqlite3VdbeNoopComment X

  15241. # else

  15242. #   define VdbeModuleComment(X)

  15243. # endif

  15244. #else

  15245. # define VdbeComment(X)

  15246. # define VdbeNoopComment(X)

  15247. # define VdbeModuleComment(X)

  15248. #endif

  15249. 

  15250. /*

  15251. ** The VdbeCoverage macros are used to set a coverage testing point

  15252. ** for VDBE branch instructions.  The coverage testing points are line

  15253. ** numbers in the sqlite3.c source file.  VDBE branch coverage testing

  15254. ** only works with an amalagmation build.  That's ok since a VDBE branch

  15255. ** coverage build designed for testing the test suite only.  No application

  15256. ** should ever ship with VDBE branch coverage measuring turned on.

  15257. **

  15258. **    VdbeCoverage(v)                  // Mark the previously coded instruction

  15259. **                                     // as a branch

  15260. **

  15261. **    VdbeCoverageIf(v, conditional)   // Mark previous if conditional true

  15262. **

  15263. **    VdbeCoverageAlwaysTaken(v)       // Previous branch is always taken

  15264. **

  15265. **    VdbeCoverageNeverTaken(v)        // Previous branch is never taken

  15266. **

  15267. **    VdbeCoverageNeverNull(v)         // Previous three-way branch is only

  15268. **                                     // taken on the first two ways.  The

  15269. **                                     // NULL option is not possible

  15270. **

  15271. **    VdbeCoverageEqNe(v)              // Previous OP_Jump is only interested

  15272. **                                     // in distingishing equal and not-equal.

  15273. **

  15274. ** Every VDBE branch operation must be tagged with one of the macros above.

  15275. ** If not, then when "make test" is run with -DSQLITE_VDBE_COVERAGE and

  15276. ** -DSQLITE_DEBUG then an ALWAYS() will fail in the vdbeTakeBranch()

  15277. ** routine in vdbe.c, alerting the developer to the missed tag.

  15278. **

  15279. ** During testing, the test application will invoke

  15280. ** sqlite3_test_control(SQLITE_TESTCTRL_VDBE_COVERAGE,...) to set a callback

  15281. ** routine that is invoked as each bytecode branch is taken.  The callback

  15282. ** contains the sqlite3.c source line number ov the VdbeCoverage macro and

  15283. ** flags to indicate whether or not the branch was taken.  The test application

  15284. ** is responsible for keeping track of this and reporting byte-code branches

  15285. ** that are never taken.

  15286. **

  15287. ** See the VdbeBranchTaken() macro and vdbeTakeBranch() function in the

  15288. ** vdbe.c source file for additional information.

  15289. */

  15290. #ifdef SQLITE_VDBE_COVERAGE

  15291. SQLITE_PRIVATE   void sqlite3VdbeSetLineNumber(Vdbe*,int);

  15292. # define VdbeCoverage(v) sqlite3VdbeSetLineNumber(v,__LINE__)

  15293. # define VdbeCoverageIf(v,x) if(x)sqlite3VdbeSetLineNumber(v,__LINE__)

  15294. # define VdbeCoverageAlwaysTaken(v) \

  15295.          sqlite3VdbeSetLineNumber(v,__LINE__|0x5000000);

  15296. # define VdbeCoverageNeverTaken(v) \

  15297.          sqlite3VdbeSetLineNumber(v,__LINE__|0x6000000);

  15298. # define VdbeCoverageNeverNull(v) \

  15299.          sqlite3VdbeSetLineNumber(v,__LINE__|0x4000000);

  15300. # define VdbeCoverageNeverNullIf(v,x) \

  15301.          if(x)sqlite3VdbeSetLineNumber(v,__LINE__|0x4000000);

  15302. # define VdbeCoverageEqNe(v) \

  15303.          sqlite3VdbeSetLineNumber(v,__LINE__|0x8000000);

  15304. # define VDBE_OFFSET_LINENO(x) (__LINE__+x)

  15305. #else

  15306. # define VdbeCoverage(v)

  15307. # define VdbeCoverageIf(v,x)

  15308. # define VdbeCoverageAlwaysTaken(v)

  15309. # define VdbeCoverageNeverTaken(v)

  15310. # define VdbeCoverageNeverNull(v)

  15311. # define VdbeCoverageNeverNullIf(v,x)

  15312. # define VdbeCoverageEqNe(v)

  15313. # define VDBE_OFFSET_LINENO(x) 0

  15314. #endif

  15315. 

  15316. #ifdef SQLITE_ENABLE_STMT_SCANSTATUS

  15317. SQLITE_PRIVATE void sqlite3VdbeScanStatus(Vdbe*, int, int, int, LogEst, const char*);

  15318. #else

  15319. # define sqlite3VdbeScanStatus(a,b,c,d,e)

  15320. #endif

  15321. 

  15322. #if defined(SQLITE_DEBUG) || defined(VDBE_PROFILE)

  15323. SQLITE_PRIVATE void sqlite3VdbePrintOp(FILE*, int, VdbeOp*);

  15324. #endif

  15325. 

  15326. #endif /* SQLITE_VDBE_H */

  15327. 

  15328. /************** End of vdbe.h ************************************************/

  15329. /************** Continuing where we left off in sqliteInt.h ******************/

  15330. /************** Include pager.h in the middle of sqliteInt.h *****************/

  15331. /************** Begin file pager.h *******************************************/

  15332. /*

  15333. ** 2001 September 15

  15334. **

  15335. ** The author disclaims copyright to this source code.  In place of

  15336. ** a legal notice, here is a blessing:

  15337. **

  15338. **    May you do good and not evil.

  15339. **    May you find forgiveness for yourself and forgive others.

  15340. **    May you share freely, never taking more than you give.

  15341. **

  15342. *************************************************************************

  15343. ** This header file defines the interface that the sqlite page cache

  15344. ** subsystem.  The page cache subsystem reads and writes a file a page

  15345. ** at a time and provides a journal for rollback.

  15346. */

  15347. 

  15348. #ifndef SQLITE_PAGER_H

  15349. #define SQLITE_PAGER_H

  15350. 

  15351. /*

  15352. ** Default maximum size for persistent journal files. A negative 

  15353. ** value means no limit. This value may be overridden using the 

  15354. ** sqlite3PagerJournalSizeLimit() API. See also "PRAGMA journal_size_limit".

  15355. */

  15356. #ifndef SQLITE_DEFAULT_JOURNAL_SIZE_LIMIT

  15357.   #define SQLITE_DEFAULT_JOURNAL_SIZE_LIMIT -1

  15358. #endif

  15359. 

  15360. /*

  15361. ** The type used to represent a page number.  The first page in a file

  15362. ** is called page 1.  0 is used to represent "not a page".

  15363. */

  15364. typedef u32 Pgno;

  15365. 

  15366. /*

  15367. ** Each open file is managed by a separate instance of the "Pager" structure.

  15368. */

  15369. typedef struct Pager Pager;

  15370. 

  15371. /*

  15372. ** Handle type for pages.

  15373. */

  15374. typedef struct PgHdr DbPage;

  15375. 

  15376. /*

  15377. ** Page number PAGER_MJ_PGNO is never used in an SQLite database (it is

  15378. ** reserved for working around a windows/posix incompatibility). It is

  15379. ** used in the journal to signify that the remainder of the journal file 

  15380. ** is devoted to storing a master journal name - there are no more pages to

  15381. ** roll back. See comments for function writeMasterJournal() in pager.c 

  15382. ** for details.

  15383. */

  15384. #define PAGER_MJ_PGNO(x) ((Pgno)((PENDING_BYTE/((x)->pageSize))+1))

  15385. 

  15386. /*

  15387. ** Allowed values for the flags parameter to sqlite3PagerOpen().

  15388. **

  15389. ** NOTE: These values must match the corresponding BTREE_ values in btree.h.

  15390. */

  15391. #define PAGER_OMIT_JOURNAL  0x0001    /* Do not use a rollback journal */

  15392. #define PAGER_MEMORY        0x0002    /* In-memory database */

  15393. 

  15394. /*

  15395. ** Valid values for the second argument to sqlite3PagerLockingMode().

  15396. */

  15397. #define PAGER_LOCKINGMODE_QUERY      -1

  15398. #define PAGER_LOCKINGMODE_NORMAL      0

  15399. #define PAGER_LOCKINGMODE_EXCLUSIVE   1

  15400. 

  15401. /*

  15402. ** Numeric constants that encode the journalmode.

  15403. **

  15404. ** The numeric values encoded here (other than PAGER_JOURNALMODE_QUERY)

  15405. ** are exposed in the API via the "PRAGMA journal_mode" command and

  15406. ** therefore cannot be changed without a compatibility break.

  15407. */

  15408. #define PAGER_JOURNALMODE_QUERY     (-1)  /* Query the value of journalmode */

  15409. #define PAGER_JOURNALMODE_DELETE      0   /* Commit by deleting journal file */

  15410. #define PAGER_JOURNALMODE_PERSIST     1   /* Commit by zeroing journal header */

  15411. #define PAGER_JOURNALMODE_OFF         2   /* Journal omitted.  */

  15412. #define PAGER_JOURNALMODE_TRUNCATE    3   /* Commit by truncating journal */

  15413. #define PAGER_JOURNALMODE_MEMORY      4   /* In-memory journal file */

  15414. #define PAGER_JOURNALMODE_WAL         5   /* Use write-ahead logging */

  15415. 

  15416. /*

  15417. ** Flags that make up the mask passed to sqlite3PagerGet().

  15418. */

  15419. #define PAGER_GET_NOCONTENT     0x01  /* Do not load data from disk */

  15420. #define PAGER_GET_READONLY      0x02  /* Read-only page is acceptable */

  15421. 

  15422. /*

  15423. ** Flags for sqlite3PagerSetFlags()

  15424. **

  15425. ** Value constraints (enforced via assert()):

  15426. **    PAGER_FULLFSYNC      == SQLITE_FullFSync

  15427. **    PAGER_CKPT_FULLFSYNC == SQLITE_CkptFullFSync

  15428. **    PAGER_CACHE_SPILL    == SQLITE_CacheSpill

  15429. */

  15430. #define PAGER_SYNCHRONOUS_OFF       0x01  /* PRAGMA synchronous=OFF */

  15431. #define PAGER_SYNCHRONOUS_NORMAL    0x02  /* PRAGMA synchronous=NORMAL */

  15432. #define PAGER_SYNCHRONOUS_FULL      0x03  /* PRAGMA synchronous=FULL */

  15433. #define PAGER_SYNCHRONOUS_EXTRA     0x04  /* PRAGMA synchronous=EXTRA */

  15434. #define PAGER_SYNCHRONOUS_MASK      0x07  /* Mask for four values above */

  15435. #define PAGER_FULLFSYNC             0x08  /* PRAGMA fullfsync=ON */

  15436. #define PAGER_CKPT_FULLFSYNC        0x10  /* PRAGMA checkpoint_fullfsync=ON */

  15437. #define PAGER_CACHESPILL            0x20  /* PRAGMA cache_spill=ON */

  15438. #define PAGER_FLAGS_MASK            0x38  /* All above except SYNCHRONOUS */

  15439. 

  15440. /*

  15441. ** The remainder of this file contains the declarations of the functions

  15442. ** that make up the Pager sub-system API. See source code comments for 

  15443. ** a detailed description of each routine.

  15444. */

  15445. 

  15446. /* Open and close a Pager connection. */ 

  15447. SQLITE_PRIVATE int sqlite3PagerOpen(

  15448.   sqlite3_vfs*,

  15449.   Pager **ppPager,

  15450.   const char*,

  15451.   int,

  15452.   int,

  15453.   int,

  15454.   void(*)(DbPage*)

  15455. );

  15456. SQLITE_PRIVATE int sqlite3PagerClose(Pager *pPager, sqlite3*);

  15457. SQLITE_PRIVATE int sqlite3PagerReadFileheader(Pager*, int, unsigned char*);

  15458. 

  15459. /* Functions used to configure a Pager object. */

  15460. SQLITE_PRIVATE void sqlite3PagerSetBusyHandler(Pager*, int(*)(void *), void *);

  15461. SQLITE_PRIVATE int sqlite3PagerSetPagesize(Pager*, u32*, int);

  15462. #ifdef SQLITE_HAS_CODEC

  15463. SQLITE_PRIVATE void sqlite3PagerAlignReserve(Pager*,Pager*);

  15464. #endif

  15465. SQLITE_PRIVATE int sqlite3PagerMaxPageCount(Pager*, int);

  15466. SQLITE_PRIVATE void sqlite3PagerSetCachesize(Pager*, int);

  15467. SQLITE_PRIVATE int sqlite3PagerSetSpillsize(Pager*, int);

  15468. SQLITE_PRIVATE void sqlite3PagerSetMmapLimit(Pager *, sqlite3_int64);

  15469. SQLITE_PRIVATE void sqlite3PagerShrink(Pager*);

  15470. SQLITE_PRIVATE void sqlite3PagerSetFlags(Pager*,unsigned);

  15471. SQLITE_PRIVATE int sqlite3PagerLockingMode(Pager *, int);

  15472. SQLITE_PRIVATE int sqlite3PagerSetJournalMode(Pager *, int);

  15473. SQLITE_PRIVATE int sqlite3PagerGetJournalMode(Pager*);

  15474. SQLITE_PRIVATE int sqlite3PagerOkToChangeJournalMode(Pager*);

  15475. SQLITE_PRIVATE i64 sqlite3PagerJournalSizeLimit(Pager *, i64);

  15476. SQLITE_PRIVATE sqlite3_backup **sqlite3PagerBackupPtr(Pager*);

  15477. SQLITE_PRIVATE int sqlite3PagerFlush(Pager*);

  15478. 

  15479. /* Functions used to obtain and release page references. */ 

  15480. SQLITE_PRIVATE int sqlite3PagerGet(Pager *pPager, Pgno pgno, DbPage **ppPage, int clrFlag);

  15481. SQLITE_PRIVATE DbPage *sqlite3PagerLookup(Pager *pPager, Pgno pgno);

  15482. SQLITE_PRIVATE void sqlite3PagerRef(DbPage*);

  15483. SQLITE_PRIVATE void sqlite3PagerUnref(DbPage*);

  15484. SQLITE_PRIVATE void sqlite3PagerUnrefNotNull(DbPage*);

  15485. SQLITE_PRIVATE void sqlite3PagerUnrefPageOne(DbPage*);

  15486. 

  15487. /* Operations on page references. */

  15488. SQLITE_PRIVATE int sqlite3PagerWrite(DbPage*);

  15489. SQLITE_PRIVATE void sqlite3PagerDontWrite(DbPage*);

  15490. SQLITE_PRIVATE int sqlite3PagerMovepage(Pager*,DbPage*,Pgno,int);

  15491. SQLITE_PRIVATE int sqlite3PagerPageRefcount(DbPage*);

  15492. SQLITE_PRIVATE void *sqlite3PagerGetData(DbPage *); 

  15493. SQLITE_PRIVATE void *sqlite3PagerGetExtra(DbPage *); 

  15494. 

  15495. /* Functions used to manage pager transactions and savepoints. */

  15496. SQLITE_PRIVATE void sqlite3PagerPagecount(Pager*, int*);

  15497. SQLITE_PRIVATE int sqlite3PagerBegin(Pager*, int exFlag, int);

  15498. SQLITE_PRIVATE int sqlite3PagerCommitPhaseOne(Pager*,const char *zMaster, int);

  15499. SQLITE_PRIVATE int sqlite3PagerExclusiveLock(Pager*);

  15500. SQLITE_PRIVATE int sqlite3PagerSync(Pager *pPager, const char *zMaster);

  15501. SQLITE_PRIVATE int sqlite3PagerCommitPhaseTwo(Pager*);

  15502. SQLITE_PRIVATE int sqlite3PagerRollback(Pager*);

  15503. SQLITE_PRIVATE int sqlite3PagerOpenSavepoint(Pager *pPager, int n);

  15504. SQLITE_PRIVATE int sqlite3PagerSavepoint(Pager *pPager, int op, int iSavepoint);

  15505. SQLITE_PRIVATE int sqlite3PagerSharedLock(Pager *pPager);

  15506. 

  15507. #ifndef SQLITE_OMIT_WAL

  15508. SQLITE_PRIVATE   int sqlite3PagerCheckpoint(Pager *pPager, sqlite3*, int, int*, int*);

  15509. SQLITE_PRIVATE   int sqlite3PagerWalSupported(Pager *pPager);

  15510. SQLITE_PRIVATE   int sqlite3PagerWalCallback(Pager *pPager);

  15511. SQLITE_PRIVATE   int sqlite3PagerOpenWal(Pager *pPager, int *pisOpen);

  15512. SQLITE_PRIVATE   int sqlite3PagerCloseWal(Pager *pPager, sqlite3*);

  15513. # ifdef SQLITE_ENABLE_SNAPSHOT

  15514. SQLITE_PRIVATE   int sqlite3PagerSnapshotGet(Pager *pPager, sqlite3_snapshot **ppSnapshot);

  15515. SQLITE_PRIVATE   int sqlite3PagerSnapshotOpen(Pager *pPager, sqlite3_snapshot *pSnapshot);

  15516. SQLITE_PRIVATE   int sqlite3PagerSnapshotRecover(Pager *pPager);

  15517. SQLITE_PRIVATE   int sqlite3PagerSnapshotCheck(Pager *pPager, sqlite3_snapshot *pSnapshot);

  15518. SQLITE_PRIVATE   void sqlite3PagerSnapshotUnlock(Pager *pPager);

  15519. # endif

  15520. #endif

  15521. 

  15522. #ifdef SQLITE_DIRECT_OVERFLOW_READ

  15523. SQLITE_PRIVATE   int sqlite3PagerDirectReadOk(Pager *pPager, Pgno pgno);

  15524. #endif

  15525. 

  15526. #ifdef SQLITE_ENABLE_ZIPVFS

  15527. SQLITE_PRIVATE   int sqlite3PagerWalFramesize(Pager *pPager);

  15528. #endif

  15529. 

  15530. /* Functions used to query pager state and configuration. */

  15531. SQLITE_PRIVATE u8 sqlite3PagerIsreadonly(Pager*);

  15532. SQLITE_PRIVATE u32 sqlite3PagerDataVersion(Pager*);

  15533. #ifdef SQLITE_DEBUG

  15534. SQLITE_PRIVATE   int sqlite3PagerRefcount(Pager*);

  15535. #endif

  15536. SQLITE_PRIVATE int sqlite3PagerMemUsed(Pager*);

  15537. SQLITE_PRIVATE const char *sqlite3PagerFilename(Pager*, int);

  15538. SQLITE_PRIVATE sqlite3_vfs *sqlite3PagerVfs(Pager*);

  15539. SQLITE_PRIVATE sqlite3_file *sqlite3PagerFile(Pager*);

  15540. SQLITE_PRIVATE sqlite3_file *sqlite3PagerJrnlFile(Pager*);

  15541. SQLITE_PRIVATE const char *sqlite3PagerJournalname(Pager*);

  15542. SQLITE_PRIVATE void *sqlite3PagerTempSpace(Pager*);

  15543. SQLITE_PRIVATE int sqlite3PagerIsMemdb(Pager*);

  15544. SQLITE_PRIVATE void sqlite3PagerCacheStat(Pager *, int, int, int *);

  15545. SQLITE_PRIVATE void sqlite3PagerClearCache(Pager*);

  15546. SQLITE_PRIVATE int sqlite3SectorSize(sqlite3_file *);

  15547. #ifdef SQLITE_ENABLE_SETLK_TIMEOUT

  15548. SQLITE_PRIVATE void sqlite3PagerResetLockTimeout(Pager *pPager);

  15549. #else

  15550. # define sqlite3PagerResetLockTimeout(X)

  15551. #endif

  15552. 

  15553. /* Functions used to truncate the database file. */

  15554. SQLITE_PRIVATE void sqlite3PagerTruncateImage(Pager*,Pgno);

  15555. 

  15556. SQLITE_PRIVATE void sqlite3PagerRekey(DbPage*, Pgno, u16);

  15557. 

  15558. #if defined(SQLITE_HAS_CODEC) && !defined(SQLITE_OMIT_WAL)

  15559. SQLITE_PRIVATE void *sqlite3PagerCodec(DbPage *);

  15560. #endif

  15561. 

  15562. /* Functions to support testing and debugging. */

  15563. #if !defined(NDEBUG) || defined(SQLITE_TEST)

  15564. SQLITE_PRIVATE   Pgno sqlite3PagerPagenumber(DbPage*);

  15565. SQLITE_PRIVATE   int sqlite3PagerIswriteable(DbPage*);

  15566. #endif

  15567. #ifdef SQLITE_TEST

  15568. SQLITE_PRIVATE   int *sqlite3PagerStats(Pager*);

  15569. SQLITE_PRIVATE   void sqlite3PagerRefdump(Pager*);

  15570.   void disable_simulated_io_errors(void);

  15571.   void enable_simulated_io_errors(void);

  15572. #else

  15573. # define disable_simulated_io_errors()

  15574. # define enable_simulated_io_errors()

  15575. #endif

  15576. 

  15577. #endif /* SQLITE_PAGER_H */

  15578. 

  15579. /************** End of pager.h ***********************************************/

  15580. /************** Continuing where we left off in sqliteInt.h ******************/

  15581. /************** Include pcache.h in the middle of sqliteInt.h ****************/

  15582. /************** Begin file pcache.h ******************************************/

  15583. /*

  15584. ** 2008 August 05

  15585. **

  15586. ** The author disclaims copyright to this source code.  In place of

  15587. ** a legal notice, here is a blessing:

  15588. **

  15589. **    May you do good and not evil.

  15590. **    May you find forgiveness for yourself and forgive others.

  15591. **    May you share freely, never taking more than you give.

  15592. **

  15593. *************************************************************************

  15594. ** This header file defines the interface that the sqlite page cache

  15595. ** subsystem. 

  15596. */

  15597. 

  15598. #ifndef _PCACHE_H_

  15599. 

  15600. typedef struct PgHdr PgHdr;

  15601. typedef struct PCache PCache;

  15602. 

  15603. /*

  15604. ** Every page in the cache is controlled by an instance of the following

  15605. ** structure.

  15606. */

  15607. struct PgHdr {

  15608.   sqlite3_pcache_page *pPage;    /* Pcache object page handle */

  15609.   void *pData;                   /* Page data */

  15610.   void *pExtra;                  /* Extra content */

  15611.   PCache *pCache;                /* PRIVATE: Cache that owns this page */

  15612.   PgHdr *pDirty;                 /* Transient list of dirty sorted by pgno */

  15613.   Pager *pPager;                 /* The pager this page is part of */

  15614.   Pgno pgno;                     /* Page number for this page */

  15615. #ifdef SQLITE_CHECK_PAGES

  15616.   u32 pageHash;                  /* Hash of page content */

  15617. #endif

  15618.   u16 flags;                     /* PGHDR flags defined below */

  15619. 

  15620.   /**********************************************************************

  15621.   ** Elements above, except pCache, are public.  All that follow are 

  15622.   ** private to pcache.c and should not be accessed by other modules.

  15623.   ** pCache is grouped with the public elements for efficiency.

  15624.   */

  15625.   i16 nRef;                      /* Number of users of this page */

  15626.   PgHdr *pDirtyNext;             /* Next element in list of dirty pages */

  15627.   PgHdr *pDirtyPrev;             /* Previous element in list of dirty pages */

  15628.                           /* NB: pDirtyNext and pDirtyPrev are undefined if the

  15629.                           ** PgHdr object is not dirty */

  15630. };

  15631. 

  15632. /* Bit values for PgHdr.flags */

  15633. #define PGHDR_CLEAN           0x001  /* Page not on the PCache.pDirty list */

  15634. #define PGHDR_DIRTY           0x002  /* Page is on the PCache.pDirty list */

  15635. #define PGHDR_WRITEABLE       0x004  /* Journaled and ready to modify */

  15636. #define PGHDR_NEED_SYNC       0x008  /* Fsync the rollback journal before

  15637.                                      ** writing this page to the database */

  15638. #define PGHDR_DONT_WRITE      0x010  /* Do not write content to disk */

  15639. #define PGHDR_MMAP            0x020  /* This is an mmap page object */

  15640. 

  15641. #define PGHDR_WAL_APPEND      0x040  /* Appended to wal file */

  15642. 

  15643. /* Initialize and shutdown the page cache subsystem */

  15644. SQLITE_PRIVATE int sqlite3PcacheInitialize(void);

  15645. SQLITE_PRIVATE void sqlite3PcacheShutdown(void);

  15646. 

  15647. /* Page cache buffer management:

  15648. ** These routines implement SQLITE_CONFIG_PAGECACHE.

  15649. */

  15650. SQLITE_PRIVATE void sqlite3PCacheBufferSetup(void *, int sz, int n);

  15651. 

  15652. /* Create a new pager cache.

  15653. ** Under memory stress, invoke xStress to try to make pages clean.

  15654. ** Only clean and unpinned pages can be reclaimed.

  15655. */

  15656. SQLITE_PRIVATE int sqlite3PcacheOpen(

  15657.   int szPage,                    /* Size of every page */

  15658.   int szExtra,                   /* Extra space associated with each page */

  15659.   int bPurgeable,                /* True if pages are on backing store */

  15660.   int (*xStress)(void*, PgHdr*), /* Call to try to make pages clean */

  15661.   void *pStress,                 /* Argument to xStress */

  15662.   PCache *pToInit                /* Preallocated space for the PCache */

  15663. );

  15664. 

  15665. /* Modify the page-size after the cache has been created. */

  15666. SQLITE_PRIVATE int sqlite3PcacheSetPageSize(PCache *, int);

  15667. 

  15668. /* Return the size in bytes of a PCache object.  Used to preallocate

  15669. ** storage space.

  15670. */

  15671. SQLITE_PRIVATE int sqlite3PcacheSize(void);

  15672. 

  15673. /* One release per successful fetch.  Page is pinned until released.

  15674. ** Reference counted. 

  15675. */

  15676. SQLITE_PRIVATE sqlite3_pcache_page *sqlite3PcacheFetch(PCache*, Pgno, int createFlag);

  15677. SQLITE_PRIVATE int sqlite3PcacheFetchStress(PCache*, Pgno, sqlite3_pcache_page**);

  15678. SQLITE_PRIVATE PgHdr *sqlite3PcacheFetchFinish(PCache*, Pgno, sqlite3_pcache_page *pPage);

  15679. SQLITE_PRIVATE void sqlite3PcacheRelease(PgHdr*);

  15680. 

  15681. SQLITE_PRIVATE void sqlite3PcacheDrop(PgHdr*);         /* Remove page from cache */

  15682. SQLITE_PRIVATE void sqlite3PcacheMakeDirty(PgHdr*);    /* Make sure page is marked dirty */

  15683. SQLITE_PRIVATE void sqlite3PcacheMakeClean(PgHdr*);    /* Mark a single page as clean */

  15684. SQLITE_PRIVATE void sqlite3PcacheCleanAll(PCache*);    /* Mark all dirty list pages as clean */

  15685. SQLITE_PRIVATE void sqlite3PcacheClearWritable(PCache*);

  15686. 

  15687. /* Change a page number.  Used by incr-vacuum. */

  15688. SQLITE_PRIVATE void sqlite3PcacheMove(PgHdr*, Pgno);

  15689. 

  15690. /* Remove all pages with pgno>x.  Reset the cache if x==0 */

  15691. SQLITE_PRIVATE void sqlite3PcacheTruncate(PCache*, Pgno x);

  15692. 

  15693. /* Get a list of all dirty pages in the cache, sorted by page number */

  15694. SQLITE_PRIVATE PgHdr *sqlite3PcacheDirtyList(PCache*);

  15695. 

  15696. /* Reset and close the cache object */

  15697. SQLITE_PRIVATE void sqlite3PcacheClose(PCache*);

  15698. 

  15699. /* Clear flags from pages of the page cache */

  15700. SQLITE_PRIVATE void sqlite3PcacheClearSyncFlags(PCache *);

  15701. 

  15702. /* Discard the contents of the cache */

  15703. SQLITE_PRIVATE void sqlite3PcacheClear(PCache*);

  15704. 

  15705. /* Return the total number of outstanding page references */

  15706. SQLITE_PRIVATE int sqlite3PcacheRefCount(PCache*);

  15707. 

  15708. /* Increment the reference count of an existing page */

  15709. SQLITE_PRIVATE void sqlite3PcacheRef(PgHdr*);

  15710. 

  15711. SQLITE_PRIVATE int sqlite3PcachePageRefcount(PgHdr*);

  15712. 

  15713. /* Return the total number of pages stored in the cache */

  15714. SQLITE_PRIVATE int sqlite3PcachePagecount(PCache*);

  15715. 

  15716. #if defined(SQLITE_CHECK_PAGES) || defined(SQLITE_DEBUG)

  15717. /* Iterate through all dirty pages currently stored in the cache. This

  15718. ** interface is only available if SQLITE_CHECK_PAGES is defined when the 

  15719. ** library is built.

  15720. */

  15721. SQLITE_PRIVATE void sqlite3PcacheIterateDirty(PCache *pCache, void (*xIter)(PgHdr *));

  15722. #endif

  15723. 

  15724. #if defined(SQLITE_DEBUG)

  15725. /* Check invariants on a PgHdr object */

  15726. SQLITE_PRIVATE int sqlite3PcachePageSanity(PgHdr*);

  15727. #endif

  15728. 

  15729. /* Set and get the suggested cache-size for the specified pager-cache.

  15730. **

  15731. ** If no global maximum is configured, then the system attempts to limit

  15732. ** the total number of pages cached by purgeable pager-caches to the sum

  15733. ** of the suggested cache-sizes.

  15734. */

  15735. SQLITE_PRIVATE void sqlite3PcacheSetCachesize(PCache *, int);

  15736. #ifdef SQLITE_TEST

  15737. SQLITE_PRIVATE int sqlite3PcacheGetCachesize(PCache *);

  15738. #endif

  15739. 

  15740. /* Set or get the suggested spill-size for the specified pager-cache.

  15741. **

  15742. ** The spill-size is the minimum number of pages in cache before the cache

  15743. ** will attempt to spill dirty pages by calling xStress.

  15744. */

  15745. SQLITE_PRIVATE int sqlite3PcacheSetSpillsize(PCache *, int);

  15746. 

  15747. /* Free up as much memory as possible from the page cache */

  15748. SQLITE_PRIVATE void sqlite3PcacheShrink(PCache*);

  15749. 

  15750. #ifdef SQLITE_ENABLE_MEMORY_MANAGEMENT

  15751. /* Try to return memory used by the pcache module to the main memory heap */

  15752. SQLITE_PRIVATE int sqlite3PcacheReleaseMemory(int);

  15753. #endif

  15754. 

  15755. #ifdef SQLITE_TEST

  15756. SQLITE_PRIVATE void sqlite3PcacheStats(int*,int*,int*,int*);

  15757. #endif

  15758. 

  15759. SQLITE_PRIVATE void sqlite3PCacheSetDefault(void);

  15760. 

  15761. /* Return the header size */

  15762. SQLITE_PRIVATE int sqlite3HeaderSizePcache(void);

  15763. SQLITE_PRIVATE int sqlite3HeaderSizePcache1(void);

  15764. 

  15765. /* Number of dirty pages as a percentage of the configured cache size */

  15766. SQLITE_PRIVATE int sqlite3PCachePercentDirty(PCache*);

  15767. 

  15768. #ifdef SQLITE_DIRECT_OVERFLOW_READ

  15769. SQLITE_PRIVATE int sqlite3PCacheIsDirty(PCache *pCache);

  15770. #endif

  15771. 

  15772. #endif /* _PCACHE_H_ */

  15773. 

  15774. /************** End of pcache.h **********************************************/

  15775. /************** Continuing where we left off in sqliteInt.h ******************/

  15776. /************** Include os.h in the middle of sqliteInt.h ********************/

  15777. /************** Begin file os.h **********************************************/

  15778. /*

  15779. ** 2001 September 16

  15780. **

  15781. ** The author disclaims copyright to this source code.  In place of

  15782. ** a legal notice, here is a blessing:

  15783. **

  15784. **    May you do good and not evil.

  15785. **    May you find forgiveness for yourself and forgive others.

  15786. **    May you share freely, never taking more than you give.

  15787. **

  15788. ******************************************************************************

  15789. **

  15790. ** This header file (together with is companion C source-code file

  15791. ** "os.c") attempt to abstract the underlying operating system so that

  15792. ** the SQLite library will work on both POSIX and windows systems.

  15793. **

  15794. ** This header file is #include-ed by sqliteInt.h and thus ends up

  15795. ** being included by every source file.

  15796. */

  15797. #ifndef _SQLITE_OS_H_

  15798. #define _SQLITE_OS_H_

  15799. 

  15800. /*

  15801. ** Attempt to automatically detect the operating system and setup the

  15802. ** necessary pre-processor macros for it.

  15803. */

  15804. /************** Include os_setup.h in the middle of os.h *********************/

  15805. /************** Begin file os_setup.h ****************************************/

  15806. /*

  15807. ** 2013 November 25

  15808. **

  15809. ** The author disclaims copyright to this source code.  In place of

  15810. ** a legal notice, here is a blessing:

  15811. **

  15812. **    May you do good and not evil.

  15813. **    May you find forgiveness for yourself and forgive others.

  15814. **    May you share freely, never taking more than you give.

  15815. **

  15816. ******************************************************************************

  15817. **

  15818. ** This file contains pre-processor directives related to operating system

  15819. ** detection and/or setup.

  15820. */

  15821. #ifndef SQLITE_OS_SETUP_H

  15822. #define SQLITE_OS_SETUP_H

  15823. 

  15824. /*

  15825. ** Figure out if we are dealing with Unix, Windows, or some other operating

  15826. ** system.

  15827. **

  15828. ** After the following block of preprocess macros, all of SQLITE_OS_UNIX,

  15829. ** SQLITE_OS_WIN, and SQLITE_OS_OTHER will defined to either 1 or 0.  One of

  15830. ** the three will be 1.  The other two will be 0.

  15831. */

  15832. #if defined(SQLITE_OS_OTHER)

  15833. #  if SQLITE_OS_OTHER==1

  15834. #    undef SQLITE_OS_UNIX

  15835. #    define SQLITE_OS_UNIX 0

  15836. #    undef SQLITE_OS_WIN

  15837. #    define SQLITE_OS_WIN 0

  15838. #  else

  15839. #    undef SQLITE_OS_OTHER

  15840. #  endif

  15841. #endif

  15842. #if !defined(SQLITE_OS_UNIX) && !defined(SQLITE_OS_OTHER)

  15843. #  define SQLITE_OS_OTHER 0

  15844. #  ifndef SQLITE_OS_WIN

  15845. #    if defined(_WIN32) || defined(WIN32) || defined(__CYGWIN__) || \

  15846.         defined(__MINGW32__) || defined(__BORLANDC__)

  15847. #      define SQLITE_OS_WIN 1

  15848. #      define SQLITE_OS_UNIX 0

  15849. #    else

  15850. #      define SQLITE_OS_WIN 0

  15851. #      define SQLITE_OS_UNIX 1

  15852. #    endif

  15853. #  else

  15854. #    define SQLITE_OS_UNIX 0

  15855. #  endif

  15856. #else

  15857. #  ifndef SQLITE_OS_WIN

  15858. #    define SQLITE_OS_WIN 0

  15859. #  endif

  15860. #endif

  15861. 

  15862. #endif /* SQLITE_OS_SETUP_H */

  15863. 

  15864. /************** End of os_setup.h ********************************************/

  15865. /************** Continuing where we left off in os.h *************************/

  15866. 

  15867. /* If the SET_FULLSYNC macro is not defined above, then make it

  15868. ** a no-op

  15869. */

  15870. #ifndef SET_FULLSYNC

  15871. # define SET_FULLSYNC(x,y)

  15872. #endif

  15873. 

  15874. /*

  15875. ** The default size of a disk sector

  15876. */

  15877. #ifndef SQLITE_DEFAULT_SECTOR_SIZE

  15878. # define SQLITE_DEFAULT_SECTOR_SIZE 4096

  15879. #endif

  15880. 

  15881. /*

  15882. ** Temporary files are named starting with this prefix followed by 16 random

  15883. ** alphanumeric characters, and no file extension. They are stored in the

  15884. ** OS's standard temporary file directory, and are deleted prior to exit.

  15885. ** If sqlite is being embedded in another program, you may wish to change the

  15886. ** prefix to reflect your program's name, so that if your program exits

  15887. ** prematurely, old temporary files can be easily identified. This can be done

  15888. ** using -DSQLITE_TEMP_FILE_PREFIX=myprefix_ on the compiler command line.

  15889. **

  15890. ** 2006-10-31:  The default prefix used to be "sqlite_".  But then

  15891. ** Mcafee started using SQLite in their anti-virus product and it

  15892. ** started putting files with the "sqlite" name in the c:/temp folder.

  15893. ** This annoyed many windows users.  Those users would then do a 

  15894. ** Google search for "sqlite", find the telephone numbers of the

  15895. ** developers and call to wake them up at night and complain.

  15896. ** For this reason, the default name prefix is changed to be "sqlite" 

  15897. ** spelled backwards.  So the temp files are still identified, but

  15898. ** anybody smart enough to figure out the code is also likely smart

  15899. ** enough to know that calling the developer will not help get rid

  15900. ** of the file.

  15901. */

  15902. #ifndef SQLITE_TEMP_FILE_PREFIX

  15903. # define SQLITE_TEMP_FILE_PREFIX "etilqs_"

  15904. #endif

  15905. 

  15906. /*

  15907. ** The following values may be passed as the second argument to

  15908. ** sqlite3OsLock(). The various locks exhibit the following semantics:

  15909. **

  15910. ** SHARED:    Any number of processes may hold a SHARED lock simultaneously.

  15911. ** RESERVED:  A single process may hold a RESERVED lock on a file at

  15912. **            any time. Other processes may hold and obtain new SHARED locks.

  15913. ** PENDING:   A single process may hold a PENDING lock on a file at

  15914. **            any one time. Existing SHARED locks may persist, but no new

  15915. **            SHARED locks may be obtained by other processes.

  15916. ** EXCLUSIVE: An EXCLUSIVE lock precludes all other locks.

  15917. **

  15918. ** PENDING_LOCK may not be passed directly to sqlite3OsLock(). Instead, a

  15919. ** process that requests an EXCLUSIVE lock may actually obtain a PENDING

  15920. ** lock. This can be upgraded to an EXCLUSIVE lock by a subsequent call to

  15921. ** sqlite3OsLock().

  15922. */

  15923. #define NO_LOCK         0

  15924. #define SHARED_LOCK     1

  15925. #define RESERVED_LOCK   2

  15926. #define PENDING_LOCK    3

  15927. #define EXCLUSIVE_LOCK  4

  15928. 

  15929. /*

  15930. ** File Locking Notes:  (Mostly about windows but also some info for Unix)

  15931. **

  15932. ** We cannot use LockFileEx() or UnlockFileEx() on Win95/98/ME because

  15933. ** those functions are not available.  So we use only LockFile() and

  15934. ** UnlockFile().

  15935. **

  15936. ** LockFile() prevents not just writing but also reading by other processes.

  15937. ** A SHARED_LOCK is obtained by locking a single randomly-chosen 

  15938. ** byte out of a specific range of bytes. The lock byte is obtained at 

  15939. ** random so two separate readers can probably access the file at the 

  15940. ** same time, unless they are unlucky and choose the same lock byte.

  15941. ** An EXCLUSIVE_LOCK is obtained by locking all bytes in the range.

  15942. ** There can only be one writer.  A RESERVED_LOCK is obtained by locking

  15943. ** a single byte of the file that is designated as the reserved lock byte.

  15944. ** A PENDING_LOCK is obtained by locking a designated byte different from

  15945. ** the RESERVED_LOCK byte.

  15946. **

  15947. ** On WinNT/2K/XP systems, LockFileEx() and UnlockFileEx() are available,

  15948. ** which means we can use reader/writer locks.  When reader/writer locks

  15949. ** are used, the lock is placed on the same range of bytes that is used

  15950. ** for probabilistic locking in Win95/98/ME.  Hence, the locking scheme

  15951. ** will support two or more Win95 readers or two or more WinNT readers.

  15952. ** But a single Win95 reader will lock out all WinNT readers and a single

  15953. ** WinNT reader will lock out all other Win95 readers.

  15954. **

  15955. ** The following #defines specify the range of bytes used for locking.

  15956. ** SHARED_SIZE is the number of bytes available in the pool from which

  15957. ** a random byte is selected for a shared lock.  The pool of bytes for

  15958. ** shared locks begins at SHARED_FIRST. 

  15959. **

  15960. ** The same locking strategy and

  15961. ** byte ranges are used for Unix.  This leaves open the possibility of having

  15962. ** clients on win95, winNT, and unix all talking to the same shared file

  15963. ** and all locking correctly.  To do so would require that samba (or whatever

  15964. ** tool is being used for file sharing) implements locks correctly between

  15965. ** windows and unix.  I'm guessing that isn't likely to happen, but by

  15966. ** using the same locking range we are at least open to the possibility.

  15967. **

  15968. ** Locking in windows is manditory.  For this reason, we cannot store

  15969. ** actual data in the bytes used for locking.  The pager never allocates

  15970. ** the pages involved in locking therefore.  SHARED_SIZE is selected so

  15971. ** that all locks will fit on a single page even at the minimum page size.

  15972. ** PENDING_BYTE defines the beginning of the locks.  By default PENDING_BYTE

  15973. ** is set high so that we don't have to allocate an unused page except

  15974. ** for very large databases.  But one should test the page skipping logic 

  15975. ** by setting PENDING_BYTE low and running the entire regression suite.

  15976. **

  15977. ** Changing the value of PENDING_BYTE results in a subtly incompatible

  15978. ** file format.  Depending on how it is changed, you might not notice

  15979. ** the incompatibility right away, even running a full regression test.

  15980. ** The default location of PENDING_BYTE is the first byte past the

  15981. ** 1GB boundary.

  15982. **

  15983. */

  15984. #ifdef SQLITE_OMIT_WSD

  15985. # define PENDING_BYTE     (0x40000000)

  15986. #else

  15987. # define PENDING_BYTE      sqlite3PendingByte

  15988. #endif

  15989. #define RESERVED_BYTE     (PENDING_BYTE+1)

  15990. #define SHARED_FIRST      (PENDING_BYTE+2)

  15991. #define SHARED_SIZE       510

  15992. 

  15993. /*

  15994. ** Wrapper around OS specific sqlite3_os_init() function.

  15995. */

  15996. SQLITE_PRIVATE int sqlite3OsInit(void);

  15997. 

  15998. /* 

  15999. ** Functions for accessing sqlite3_file methods 

  16000. */

  16001. SQLITE_PRIVATE void sqlite3OsClose(sqlite3_file*);

  16002. SQLITE_PRIVATE int sqlite3OsRead(sqlite3_file*, void*, int amt, i64 offset);

  16003. SQLITE_PRIVATE int sqlite3OsWrite(sqlite3_file*, const void*, int amt, i64 offset);

  16004. SQLITE_PRIVATE int sqlite3OsTruncate(sqlite3_file*, i64 size);

  16005. SQLITE_PRIVATE int sqlite3OsSync(sqlite3_file*, int);

  16006. SQLITE_PRIVATE int sqlite3OsFileSize(sqlite3_file*, i64 *pSize);

  16007. SQLITE_PRIVATE int sqlite3OsLock(sqlite3_file*, int);

  16008. SQLITE_PRIVATE int sqlite3OsUnlock(sqlite3_file*, int);

  16009. SQLITE_PRIVATE int sqlite3OsCheckReservedLock(sqlite3_file *id, int *pResOut);

  16010. SQLITE_PRIVATE int sqlite3OsFileControl(sqlite3_file*,int,void*);

  16011. SQLITE_PRIVATE void sqlite3OsFileControlHint(sqlite3_file*,int,void*);

  16012. #define SQLITE_FCNTL_DB_UNCHANGED 0xca093fa0

  16013. SQLITE_PRIVATE int sqlite3OsSectorSize(sqlite3_file *id);

  16014. SQLITE_PRIVATE int sqlite3OsDeviceCharacteristics(sqlite3_file *id);

  16015. #ifndef SQLITE_OMIT_WAL

  16016. SQLITE_PRIVATE int sqlite3OsShmMap(sqlite3_file *,int,int,int,void volatile **);

  16017. SQLITE_PRIVATE int sqlite3OsShmLock(sqlite3_file *id, int, int, int);

  16018. SQLITE_PRIVATE void sqlite3OsShmBarrier(sqlite3_file *id);

  16019. SQLITE_PRIVATE int sqlite3OsShmUnmap(sqlite3_file *id, int);

  16020. #endif /* SQLITE_OMIT_WAL */

  16021. SQLITE_PRIVATE int sqlite3OsFetch(sqlite3_file *id, i64, int, void **);

  16022. SQLITE_PRIVATE int sqlite3OsUnfetch(sqlite3_file *, i64, void *);

  16023. 

  16024. 

  16025. /* 

  16026. ** Functions for accessing sqlite3_vfs methods 

  16027. */

  16028. SQLITE_PRIVATE int sqlite3OsOpen(sqlite3_vfs *, const char *, sqlite3_file*, int, int *);

  16029. SQLITE_PRIVATE int sqlite3OsDelete(sqlite3_vfs *, const char *, int);

  16030. SQLITE_PRIVATE int sqlite3OsAccess(sqlite3_vfs *, const char *, int, int *pResOut);

  16031. SQLITE_PRIVATE int sqlite3OsFullPathname(sqlite3_vfs *, const char *, int, char *);

  16032. #ifndef SQLITE_OMIT_LOAD_EXTENSION

  16033. SQLITE_PRIVATE void *sqlite3OsDlOpen(sqlite3_vfs *, const char *);

  16034. SQLITE_PRIVATE void sqlite3OsDlError(sqlite3_vfs *, int, char *);

  16035. SQLITE_PRIVATE void (*sqlite3OsDlSym(sqlite3_vfs *, void *, const char *))(void);

  16036. SQLITE_PRIVATE void sqlite3OsDlClose(sqlite3_vfs *, void *);

  16037. #endif /* SQLITE_OMIT_LOAD_EXTENSION */

  16038. SQLITE_PRIVATE int sqlite3OsRandomness(sqlite3_vfs *, int, char *);

  16039. SQLITE_PRIVATE int sqlite3OsSleep(sqlite3_vfs *, int);

  16040. SQLITE_PRIVATE int sqlite3OsGetLastError(sqlite3_vfs*);

  16041. SQLITE_PRIVATE int sqlite3OsCurrentTimeInt64(sqlite3_vfs *, sqlite3_int64*);

  16042. 

  16043. /*

  16044. ** Convenience functions for opening and closing files using 

  16045. ** sqlite3_malloc() to obtain space for the file-handle structure.

  16046. */

  16047. SQLITE_PRIVATE int sqlite3OsOpenMalloc(sqlite3_vfs *, const char *, sqlite3_file **, int,int*);

  16048. SQLITE_PRIVATE void sqlite3OsCloseFree(sqlite3_file *);

  16049. 

  16050. #endif /* _SQLITE_OS_H_ */

  16051. 

  16052. /************** End of os.h **************************************************/

  16053. /************** Continuing where we left off in sqliteInt.h ******************/

  16054. /************** Include mutex.h in the middle of sqliteInt.h *****************/

  16055. /************** Begin file mutex.h *******************************************/

  16056. /*

  16057. ** 2007 August 28

  16058. **

  16059. ** The author disclaims copyright to this source code.  In place of

  16060. ** a legal notice, here is a blessing:

  16061. **

  16062. **    May you do good and not evil.

  16063. **    May you find forgiveness for yourself and forgive others.

  16064. **    May you share freely, never taking more than you give.

  16065. **

  16066. *************************************************************************

  16067. **

  16068. ** This file contains the common header for all mutex implementations.

  16069. ** The sqliteInt.h header #includes this file so that it is available

  16070. ** to all source files.  We break it out in an effort to keep the code

  16071. ** better organized.

  16072. **

  16073. ** NOTE:  source files should *not* #include this header file directly.

  16074. ** Source files should #include the sqliteInt.h file and let that file

  16075. ** include this one indirectly.

  16076. */

  16077. 

  16078. 

  16079. /*

  16080. ** Figure out what version of the code to use.  The choices are

  16081. **

  16082. **   SQLITE_MUTEX_OMIT         No mutex logic.  Not even stubs.  The

  16083. **                             mutexes implementation cannot be overridden

  16084. **                             at start-time.

  16085. **

  16086. **   SQLITE_MUTEX_NOOP         For single-threaded applications.  No

  16087. **                             mutual exclusion is provided.  But this

  16088. **                             implementation can be overridden at

  16089. **                             start-time.

  16090. **

  16091. **   SQLITE_MUTEX_PTHREADS     For multi-threaded applications on Unix.

  16092. **

  16093. **   SQLITE_MUTEX_W32          For multi-threaded applications on Win32.

  16094. */

  16095. #if !SQLITE_THREADSAFE

  16096. # define SQLITE_MUTEX_OMIT

  16097. #endif

  16098. #if SQLITE_THREADSAFE && !defined(SQLITE_MUTEX_NOOP)

  16099. #  if SQLITE_OS_UNIX

  16100. #    define SQLITE_MUTEX_PTHREADS

  16101. #  elif SQLITE_OS_WIN

  16102. #    define SQLITE_MUTEX_W32

  16103. #  else

  16104. #    define SQLITE_MUTEX_NOOP

  16105. #  endif

  16106. #endif

  16107. 

  16108. #ifdef SQLITE_MUTEX_OMIT

  16109. /*

  16110. ** If this is a no-op implementation, implement everything as macros.

  16111. */

  16112. #define sqlite3_mutex_alloc(X)    ((sqlite3_mutex*)8)

  16113. #define sqlite3_mutex_free(X)

  16114. #define sqlite3_mutex_enter(X)    

  16115. #define sqlite3_mutex_try(X)      SQLITE_OK

  16116. #define sqlite3_mutex_leave(X)    

  16117. #define sqlite3_mutex_held(X)     ((void)(X),1)

  16118. #define sqlite3_mutex_notheld(X)  ((void)(X),1)

  16119. #define sqlite3MutexAlloc(X)      ((sqlite3_mutex*)8)

  16120. #define sqlite3MutexInit()        SQLITE_OK

  16121. #define sqlite3MutexEnd()

  16122. #define MUTEX_LOGIC(X)

  16123. #else

  16124. #define MUTEX_LOGIC(X)            X

  16125. #endif /* defined(SQLITE_MUTEX_OMIT) */

  16126. 

  16127. /************** End of mutex.h ***********************************************/

  16128. /************** Continuing where we left off in sqliteInt.h ******************/

  16129. 

  16130. /* The SQLITE_EXTRA_DURABLE compile-time option used to set the default

  16131. ** synchronous setting to EXTRA.  It is no longer supported.

  16132. */

  16133. #ifdef SQLITE_EXTRA_DURABLE

  16134. # warning Use SQLITE_DEFAULT_SYNCHRONOUS=3 instead of SQLITE_EXTRA_DURABLE

  16135. # define SQLITE_DEFAULT_SYNCHRONOUS 3

  16136. #endif

  16137. 

  16138. /*

  16139. ** Default synchronous levels.

  16140. **

  16141. ** Note that (for historcal reasons) the PAGER_SYNCHRONOUS_* macros differ

  16142. ** from the SQLITE_DEFAULT_SYNCHRONOUS value by 1.

  16143. **

  16144. **           PAGER_SYNCHRONOUS       DEFAULT_SYNCHRONOUS

  16145. **   OFF           1                         0

  16146. **   NORMAL        2                         1

  16147. **   FULL          3                         2

  16148. **   EXTRA         4                         3

  16149. **

  16150. ** The "PRAGMA synchronous" statement also uses the zero-based numbers.

  16151. ** In other words, the zero-based numbers are used for all external interfaces

  16152. ** and the one-based values are used internally.

  16153. */

  16154. #ifndef SQLITE_DEFAULT_SYNCHRONOUS

  16155. # define SQLITE_DEFAULT_SYNCHRONOUS 2

  16156. #endif

  16157. #ifndef SQLITE_DEFAULT_WAL_SYNCHRONOUS

  16158. # define SQLITE_DEFAULT_WAL_SYNCHRONOUS SQLITE_DEFAULT_SYNCHRONOUS

  16159. #endif

  16160. 

  16161. /*

  16162. ** Each database file to be accessed by the system is an instance

  16163. ** of the following structure.  There are normally two of these structures

  16164. ** in the sqlite.aDb[] array.  aDb[0] is the main database file and

  16165. ** aDb[1] is the database file used to hold temporary tables.  Additional

  16166. ** databases may be attached.

  16167. */

  16168. struct Db {

  16169.   char *zDbSName;      /* Name of this database. (schema name, not filename) */

  16170.   Btree *pBt;          /* The B*Tree structure for this database file */

  16171.   u8 safety_level;     /* How aggressive at syncing data to disk */

  16172.   u8 bSyncSet;         /* True if "PRAGMA synchronous=N" has been run */

  16173.   Schema *pSchema;     /* Pointer to database schema (possibly shared) */

  16174. };

  16175. 

  16176. /*

  16177. ** An instance of the following structure stores a database schema.

  16178. **

  16179. ** Most Schema objects are associated with a Btree.  The exception is

  16180. ** the Schema for the TEMP databaes (sqlite3.aDb[1]) which is free-standing.

  16181. ** In shared cache mode, a single Schema object can be shared by multiple

  16182. ** Btrees that refer to the same underlying BtShared object.

  16183. **

  16184. ** Schema objects are automatically deallocated when the last Btree that

  16185. ** references them is destroyed.   The TEMP Schema is manually freed by

  16186. ** sqlite3_close().

  16187. *

  16188. ** A thread must be holding a mutex on the corresponding Btree in order

  16189. ** to access Schema content.  This implies that the thread must also be

  16190. ** holding a mutex on the sqlite3 connection pointer that owns the Btree.

  16191. ** For a TEMP Schema, only the connection mutex is required.

  16192. */

  16193. struct Schema {

  16194.   int schema_cookie;   /* Database schema version number for this file */

  16195.   int iGeneration;     /* Generation counter.  Incremented with each change */

  16196.   Hash tblHash;        /* All tables indexed by name */

  16197.   Hash idxHash;        /* All (named) indices indexed by name */

  16198.   Hash trigHash;       /* All triggers indexed by name */

  16199.   Hash fkeyHash;       /* All foreign keys by referenced table name */

  16200.   Table *pSeqTab;      /* The sqlite_sequence table used by AUTOINCREMENT */

  16201.   u8 file_format;      /* Schema format version for this file */

  16202.   u8 enc;              /* Text encoding used by this database */

  16203.   u16 schemaFlags;     /* Flags associated with this schema */

  16204.   int cache_size;      /* Number of pages to use in the cache */

  16205. };

  16206. 

  16207. /*

  16208. ** These macros can be used to test, set, or clear bits in the

  16209. ** Db.pSchema->flags field.

  16210. */

  16211. #define DbHasProperty(D,I,P)     (((D)->aDb[I].pSchema->schemaFlags&(P))==(P))

  16212. #define DbHasAnyProperty(D,I,P)  (((D)->aDb[I].pSchema->schemaFlags&(P))!=0)

  16213. #define DbSetProperty(D,I,P)     (D)->aDb[I].pSchema->schemaFlags|=(P)

  16214. #define DbClearProperty(D,I,P)   (D)->aDb[I].pSchema->schemaFlags&=~(P)

  16215. 

  16216. /*

  16217. ** Allowed values for the DB.pSchema->flags field.

  16218. **

  16219. ** The DB_SchemaLoaded flag is set after the database schema has been

  16220. ** read into internal hash tables.

  16221. **

  16222. ** DB_UnresetViews means that one or more views have column names that

  16223. ** have been filled out.  If the schema changes, these column names might

  16224. ** changes and so the view will need to be reset.

  16225. */

  16226. #define DB_SchemaLoaded    0x0001  /* The schema has been loaded */

  16227. #define DB_UnresetViews    0x0002  /* Some views have defined column names */

  16228. #define DB_Empty           0x0004  /* The file is empty (length 0 bytes) */

  16229. #define DB_ResetWanted     0x0008  /* Reset the schema when nSchemaLock==0 */

  16230. 

  16231. /*

  16232. ** The number of different kinds of things that can be limited

  16233. ** using the sqlite3_limit() interface.

  16234. */

  16235. #define SQLITE_N_LIMIT (SQLITE_LIMIT_WORKER_THREADS+1)

  16236. 

  16237. /*

  16238. ** Lookaside malloc is a set of fixed-size buffers that can be used

  16239. ** to satisfy small transient memory allocation requests for objects

  16240. ** associated with a particular database connection.  The use of

  16241. ** lookaside malloc provides a significant performance enhancement

  16242. ** (approx 10%) by avoiding numerous malloc/free requests while parsing

  16243. ** SQL statements.

  16244. **

  16245. ** The Lookaside structure holds configuration information about the

  16246. ** lookaside malloc subsystem.  Each available memory allocation in

  16247. ** the lookaside subsystem is stored on a linked list of LookasideSlot

  16248. ** objects.

  16249. **

  16250. ** Lookaside allocations are only allowed for objects that are associated

  16251. ** with a particular database connection.  Hence, schema information cannot

  16252. ** be stored in lookaside because in shared cache mode the schema information

  16253. ** is shared by multiple database connections.  Therefore, while parsing

  16254. ** schema information, the Lookaside.bEnabled flag is cleared so that

  16255. ** lookaside allocations are not used to construct the schema objects.

  16256. */

  16257. struct Lookaside {

  16258.   u32 bDisable;           /* Only operate the lookaside when zero */

  16259.   u16 sz;                 /* Size of each buffer in bytes */

  16260.   u8 bMalloced;           /* True if pStart obtained from sqlite3_malloc() */

  16261.   u32 nSlot;              /* Number of lookaside slots allocated */

  16262.   u32 anStat[3];          /* 0: hits.  1: size misses.  2: full misses */

  16263.   LookasideSlot *pInit;   /* List of buffers not previously used */

  16264.   LookasideSlot *pFree;   /* List of available buffers */

  16265.   void *pStart;           /* First byte of available memory space */

  16266.   void *pEnd;             /* First byte past end of available space */

  16267. };

  16268. struct LookasideSlot {

  16269.   LookasideSlot *pNext;    /* Next buffer in the list of free buffers */

  16270. };

  16271. 

  16272. /*

  16273. ** A hash table for built-in function definitions.  (Application-defined

  16274. ** functions use a regular table table from hash.h.)

  16275. **

  16276. ** Hash each FuncDef structure into one of the FuncDefHash.a[] slots.

  16277. ** Collisions are on the FuncDef.u.pHash chain.  Use the SQLITE_FUNC_HASH()

  16278. ** macro to compute a hash on the function name.

  16279. */

  16280. #define SQLITE_FUNC_HASH_SZ 23

  16281. struct FuncDefHash {

  16282.   FuncDef *a[SQLITE_FUNC_HASH_SZ];       /* Hash table for functions */

  16283. };

  16284. #define SQLITE_FUNC_HASH(C,L) (((C)+(L))%SQLITE_FUNC_HASH_SZ)

  16285. 

  16286. #ifdef SQLITE_USER_AUTHENTICATION

  16287. /*

  16288. ** Information held in the "sqlite3" database connection object and used

  16289. ** to manage user authentication.

  16290. */

  16291. typedef struct sqlite3_userauth sqlite3_userauth;

  16292. struct sqlite3_userauth {

  16293.   u8 authLevel;                 /* Current authentication level */

  16294.   int nAuthPW;                  /* Size of the zAuthPW in bytes */

  16295.   char *zAuthPW;                /* Password used to authenticate */

  16296.   char *zAuthUser;              /* User name used to authenticate */

  16297. };

  16298. 

  16299. /* Allowed values for sqlite3_userauth.authLevel */

  16300. #define UAUTH_Unknown     0     /* Authentication not yet checked */

  16301. #define UAUTH_Fail        1     /* User authentication failed */

  16302. #define UAUTH_User        2     /* Authenticated as a normal user */

  16303. #define UAUTH_Admin       3     /* Authenticated as an administrator */

  16304. 

  16305. /* Functions used only by user authorization logic */

  16306. SQLITE_PRIVATE int sqlite3UserAuthTable(const char*);

  16307. SQLITE_PRIVATE int sqlite3UserAuthCheckLogin(sqlite3*,const char*,u8*);

  16308. SQLITE_PRIVATE void sqlite3UserAuthInit(sqlite3*);

  16309. SQLITE_PRIVATE void sqlite3CryptFunc(sqlite3_context*,int,sqlite3_value**);

  16310. 

  16311. #endif /* SQLITE_USER_AUTHENTICATION */

  16312. 

  16313. /*

  16314. ** typedef for the authorization callback function.

  16315. */

  16316. #ifdef SQLITE_USER_AUTHENTICATION

  16317.   typedef int (*sqlite3_xauth)(void*,int,const char*,const char*,const char*,

  16318.                                const char*, const char*);

  16319. #else

  16320.   typedef int (*sqlite3_xauth)(void*,int,const char*,const char*,const char*,

  16321.                                const char*);

  16322. #endif

  16323. 

  16324. #ifndef SQLITE_OMIT_DEPRECATED

  16325. /* This is an extra SQLITE_TRACE macro that indicates "legacy" tracing

  16326. ** in the style of sqlite3_trace()

  16327. */

  16328. #define SQLITE_TRACE_LEGACY          0x40     /* Use the legacy xTrace */

  16329. #define SQLITE_TRACE_XPROFILE        0x80     /* Use the legacy xProfile */

  16330. #else

  16331. #define SQLITE_TRACE_LEGACY          0

  16332. #define SQLITE_TRACE_XPROFILE        0

  16333. #endif /* SQLITE_OMIT_DEPRECATED */

  16334. #define SQLITE_TRACE_NONLEGACY_MASK  0x0f     /* Normal flags */

  16335. 

  16336. 

  16337. /*

  16338. ** Each database connection is an instance of the following structure.

  16339. */

  16340. struct sqlite3 {

  16341.   sqlite3_vfs *pVfs;            /* OS Interface */

  16342.   struct Vdbe *pVdbe;           /* List of active virtual machines */

  16343.   CollSeq *pDfltColl;           /* The default collating sequence (BINARY) */

  16344.   sqlite3_mutex *mutex;         /* Connection mutex */

  16345.   Db *aDb;                      /* All backends */

  16346.   int nDb;                      /* Number of backends currently in use */

  16347.   u32 mDbFlags;                 /* flags recording internal state */

  16348.   u64 flags;                    /* flags settable by pragmas. See below */

  16349.   i64 lastRowid;                /* ROWID of most recent insert (see above) */

  16350.   i64 szMmap;                   /* Default mmap_size setting */

  16351.   u32 nSchemaLock;              /* Do not reset the schema when non-zero */

  16352.   unsigned int openFlags;       /* Flags passed to sqlite3_vfs.xOpen() */

  16353.   int errCode;                  /* Most recent error code (SQLITE_*) */

  16354.   int errMask;                  /* & result codes with this before returning */

  16355.   int iSysErrno;                /* Errno value from last system error */

  16356.   u16 dbOptFlags;               /* Flags to enable/disable optimizations */

  16357.   u8 enc;                       /* Text encoding */

  16358.   u8 autoCommit;                /* The auto-commit flag. */

  16359.   u8 temp_store;                /* 1: file 2: memory 0: default */

  16360.   u8 mallocFailed;              /* True if we have seen a malloc failure */

  16361.   u8 bBenignMalloc;             /* Do not require OOMs if true */

  16362.   u8 dfltLockMode;              /* Default locking-mode for attached dbs */

  16363.   signed char nextAutovac;      /* Autovac setting after VACUUM if >=0 */

  16364.   u8 suppressErr;               /* Do not issue error messages if true */

  16365.   u8 vtabOnConflict;            /* Value to return for s3_vtab_on_conflict() */

  16366.   u8 isTransactionSavepoint;    /* True if the outermost savepoint is a TS */

  16367.   u8 mTrace;                    /* zero or more SQLITE_TRACE flags */

  16368.   u8 noSharedCache;             /* True if no shared-cache backends */

  16369.   u8 nSqlExec;                  /* Number of pending OP_SqlExec opcodes */

  16370.   int nextPagesize;             /* Pagesize after VACUUM if >0 */

  16371.   u32 magic;                    /* Magic number for detect library misuse */

  16372.   int nChange;                  /* Value returned by sqlite3_changes() */

  16373.   int nTotalChange;             /* Value returned by sqlite3_total_changes() */

  16374.   int aLimit[SQLITE_N_LIMIT];   /* Limits */

  16375.   int nMaxSorterMmap;           /* Maximum size of regions mapped by sorter */

  16376.   struct sqlite3InitInfo {      /* Information used during initialization */

  16377.     int newTnum;                /* Rootpage of table being initialized */

  16378.     u8 iDb;                     /* Which db file is being initialized */

  16379.     u8 busy;                    /* TRUE if currently initializing */

  16380.     unsigned orphanTrigger : 1; /* Last statement is orphaned TEMP trigger */

  16381.     unsigned imposterTable : 1; /* Building an imposter table */

  16382.     unsigned reopenMemdb : 1;   /* ATTACH is really a reopen using MemDB */

  16383.   } init;

  16384.   int nVdbeActive;              /* Number of VDBEs currently running */

  16385.   int nVdbeRead;                /* Number of active VDBEs that read or write */

  16386.   int nVdbeWrite;               /* Number of active VDBEs that read and write */

  16387.   int nVdbeExec;                /* Number of nested calls to VdbeExec() */

  16388.   int nVDestroy;                /* Number of active OP_VDestroy operations */

  16389.   int nExtension;               /* Number of loaded extensions */

  16390.   void **aExtension;            /* Array of shared library handles */

  16391.   int (*xTrace)(u32,void*,void*,void*);     /* Trace function */

  16392.   void *pTraceArg;                          /* Argument to the trace function */

  16393. #ifndef SQLITE_OMIT_DEPRECATED

  16394.   void (*xProfile)(void*,const char*,u64);  /* Profiling function */

  16395.   void *pProfileArg;                        /* Argument to profile function */

  16396. #endif

  16397.   void *pCommitArg;                 /* Argument to xCommitCallback() */

  16398.   int (*xCommitCallback)(void*);    /* Invoked at every commit. */

  16399.   void *pRollbackArg;               /* Argument to xRollbackCallback() */

  16400.   void (*xRollbackCallback)(void*); /* Invoked at every commit. */

  16401.   void *pUpdateArg;

  16402.   void (*xUpdateCallback)(void*,int, const char*,const char*,sqlite_int64);

  16403.   Parse *pParse;                /* Current parse */

  16404. #ifdef SQLITE_ENABLE_PREUPDATE_HOOK

  16405.   void *pPreUpdateArg;          /* First argument to xPreUpdateCallback */

  16406.   void (*xPreUpdateCallback)(   /* Registered using sqlite3_preupdate_hook() */

  16407.     void*,sqlite3*,int,char const*,char const*,sqlite3_int64,sqlite3_int64

  16408.   );

  16409.   PreUpdate *pPreUpdate;        /* Context for active pre-update callback */

  16410. #endif /* SQLITE_ENABLE_PREUPDATE_HOOK */

  16411. #ifndef SQLITE_OMIT_WAL

  16412.   int (*xWalCallback)(void *, sqlite3 *, const char *, int);

  16413.   void *pWalArg;

  16414. #endif

  16415.   void(*xCollNeeded)(void*,sqlite3*,int eTextRep,const char*);

  16416.   void(*xCollNeeded16)(void*,sqlite3*,int eTextRep,const void*);

  16417.   void *pCollNeededArg;

  16418.   sqlite3_value *pErr;          /* Most recent error message */

  16419.   union {

  16420.     volatile int isInterrupted; /* True if sqlite3_interrupt has been called */

  16421.     double notUsed1;            /* Spacer */

  16422.   } u1;

  16423.   Lookaside lookaside;          /* Lookaside malloc configuration */

  16424. #ifndef SQLITE_OMIT_AUTHORIZATION

  16425.   sqlite3_xauth xAuth;          /* Access authorization function */

  16426.   void *pAuthArg;               /* 1st argument to the access auth function */

  16427. #endif

  16428. #ifndef SQLITE_OMIT_PROGRESS_CALLBACK

  16429.   int (*xProgress)(void *);     /* The progress callback */

  16430.   void *pProgressArg;           /* Argument to the progress callback */

  16431.   unsigned nProgressOps;        /* Number of opcodes for progress callback */

  16432. #endif

  16433. #ifndef SQLITE_OMIT_VIRTUALTABLE

  16434.   int nVTrans;                  /* Allocated size of aVTrans */

  16435.   Hash aModule;                 /* populated by sqlite3_create_module() */

  16436.   VtabCtx *pVtabCtx;            /* Context for active vtab connect/create */

  16437.   VTable **aVTrans;             /* Virtual tables with open transactions */

  16438.   VTable *pDisconnect;          /* Disconnect these in next sqlite3_prepare() */

  16439. #endif

  16440.   Hash aFunc;                   /* Hash table of connection functions */

  16441.   Hash aCollSeq;                /* All collating sequences */

  16442.   BusyHandler busyHandler;      /* Busy callback */

  16443.   Db aDbStatic[2];              /* Static space for the 2 default backends */

  16444.   Savepoint *pSavepoint;        /* List of active savepoints */

  16445.   int busyTimeout;              /* Busy handler timeout, in msec */

  16446.   int nSavepoint;               /* Number of non-transaction savepoints */

  16447.   int nStatement;               /* Number of nested statement-transactions  */

  16448.   i64 nDeferredCons;            /* Net deferred constraints this transaction. */

  16449.   i64 nDeferredImmCons;         /* Net deferred immediate constraints */

  16450.   int *pnBytesFreed;            /* If not NULL, increment this in DbFree() */

  16451. #ifdef SQLITE_ENABLE_UNLOCK_NOTIFY

  16452.   /* The following variables are all protected by the STATIC_MASTER

  16453.   ** mutex, not by sqlite3.mutex. They are used by code in notify.c.

  16454.   **

  16455.   ** When X.pUnlockConnection==Y, that means that X is waiting for Y to

  16456.   ** unlock so that it can proceed.

  16457.   **

  16458.   ** When X.pBlockingConnection==Y, that means that something that X tried

  16459.   ** tried to do recently failed with an SQLITE_LOCKED error due to locks

  16460.   ** held by Y.

  16461.   */

  16462.   sqlite3 *pBlockingConnection; /* Connection that caused SQLITE_LOCKED */

  16463.   sqlite3 *pUnlockConnection;           /* Connection to watch for unlock */

  16464.   void *pUnlockArg;                     /* Argument to xUnlockNotify */

  16465.   void (*xUnlockNotify)(void **, int);  /* Unlock notify callback */

  16466.   sqlite3 *pNextBlocked;        /* Next in list of all blocked connections */

  16467. #endif

  16468. #ifdef SQLITE_USER_AUTHENTICATION

  16469.   sqlite3_userauth auth;        /* User authentication information */

  16470. #endif

  16471. };

  16472. 

  16473. /*

  16474. ** A macro to discover the encoding of a database.

  16475. */

  16476. #define SCHEMA_ENC(db) ((db)->aDb[0].pSchema->enc)

  16477. #define ENC(db)        ((db)->enc)

  16478. 

  16479. /*

  16480. ** Possible values for the sqlite3.flags.

  16481. **

  16482. ** Value constraints (enforced via assert()):

  16483. **      SQLITE_FullFSync     == PAGER_FULLFSYNC

  16484. **      SQLITE_CkptFullFSync == PAGER_CKPT_FULLFSYNC

  16485. **      SQLITE_CacheSpill    == PAGER_CACHE_SPILL

  16486. */

  16487. #define SQLITE_WriteSchema    0x00000001  /* OK to update SQLITE_MASTER */

  16488. #define SQLITE_LegacyFileFmt  0x00000002  /* Create new databases in format 1 */

  16489. #define SQLITE_FullColNames   0x00000004  /* Show full column names on SELECT */

  16490. #define SQLITE_FullFSync      0x00000008  /* Use full fsync on the backend */

  16491. #define SQLITE_CkptFullFSync  0x00000010  /* Use full fsync for checkpoint */

  16492. #define SQLITE_CacheSpill     0x00000020  /* OK to spill pager cache */

  16493. #define SQLITE_ShortColNames  0x00000040  /* Show short columns names */

  16494. #define SQLITE_CountRows      0x00000080  /* Count rows changed by INSERT, */

  16495.                                           /*   DELETE, or UPDATE and return */

  16496.                                           /*   the count using a callback. */

  16497. #define SQLITE_NullCallback   0x00000100  /* Invoke the callback once if the */

  16498.                                           /*   result set is empty */

  16499. #define SQLITE_IgnoreChecks   0x00000200  /* Do not enforce check constraints */

  16500. #define SQLITE_ReadUncommit   0x00000400  /* READ UNCOMMITTED in shared-cache */

  16501. #define SQLITE_NoCkptOnClose  0x00000800  /* No checkpoint on close()/DETACH */

  16502. #define SQLITE_ReverseOrder   0x00001000  /* Reverse unordered SELECTs */

  16503. #define SQLITE_RecTriggers    0x00002000  /* Enable recursive triggers */

  16504. #define SQLITE_ForeignKeys    0x00004000  /* Enforce foreign key constraints  */

  16505. #define SQLITE_AutoIndex      0x00008000  /* Enable automatic indexes */

  16506. #define SQLITE_LoadExtension  0x00010000  /* Enable load_extension */

  16507. #define SQLITE_LoadExtFunc    0x00020000  /* Enable load_extension() SQL func */

  16508. #define SQLITE_EnableTrigger  0x00040000  /* True to enable triggers */

  16509. #define SQLITE_DeferFKs       0x00080000  /* Defer all FK constraints */

  16510. #define SQLITE_QueryOnly      0x00100000  /* Disable database changes */

  16511. #define SQLITE_CellSizeCk     0x00200000  /* Check btree cell sizes on load */

  16512. #define SQLITE_Fts3Tokenizer  0x00400000  /* Enable fts3_tokenizer(2) */

  16513. #define SQLITE_EnableQPSG     0x00800000  /* Query Planner Stability Guarantee*/

  16514. #define SQLITE_TriggerEQP     0x01000000  /* Show trigger EXPLAIN QUERY PLAN */

  16515. #define SQLITE_ResetDatabase  0x02000000  /* Reset the database */

  16516. #define SQLITE_LegacyAlter    0x04000000  /* Legacy ALTER TABLE behaviour */

  16517. #define SQLITE_NoSchemaError  0x08000000  /* Do not report schema parse errors*/

  16518. #define SQLITE_Defensive      0x10000000  /* Input SQL is likely hostile */

  16519. #define SQLITE_DqsDDL         0x20000000  /* dbl-quoted strings allowed in DDL*/

  16520. #define SQLITE_DqsDML         0x40000000  /* dbl-quoted strings allowed in DML*/

  16521. 

  16522. /* Flags used only if debugging */

  16523. #define HI(X)  ((u64)(X)<<32)

  16524. #ifdef SQLITE_DEBUG

  16525. #define SQLITE_SqlTrace       HI(0x0001)  /* Debug print SQL as it executes */

  16526. #define SQLITE_VdbeListing    HI(0x0002)  /* Debug listings of VDBE progs */

  16527. #define SQLITE_VdbeTrace      HI(0x0004)  /* True to trace VDBE execution */

  16528. #define SQLITE_VdbeAddopTrace HI(0x0008)  /* Trace sqlite3VdbeAddOp() calls */

  16529. #define SQLITE_VdbeEQP        HI(0x0010)  /* Debug EXPLAIN QUERY PLAN */

  16530. #define SQLITE_ParserTrace    HI(0x0020)  /* PRAGMA parser_trace=ON */

  16531. #endif

  16532. 

  16533. /*

  16534. ** Allowed values for sqlite3.mDbFlags

  16535. */

  16536. #define DBFLAG_SchemaChange   0x0001  /* Uncommitted Hash table changes */

  16537. #define DBFLAG_PreferBuiltin  0x0002  /* Preference to built-in funcs */

  16538. #define DBFLAG_Vacuum         0x0004  /* Currently in a VACUUM */

  16539. #define DBFLAG_VacuumInto     0x0008  /* Currently running VACUUM INTO */

  16540. #define DBFLAG_SchemaKnownOk  0x0010  /* Schema is known to be valid */

  16541. 

  16542. /*

  16543. ** Bits of the sqlite3.dbOptFlags field that are used by the

  16544. ** sqlite3_test_control(SQLITE_TESTCTRL_OPTIMIZATIONS,...) interface to

  16545. ** selectively disable various optimizations.

  16546. */

  16547. #define SQLITE_QueryFlattener 0x0001   /* Query flattening */

  16548. #define SQLITE_WindowFunc     0x0002   /* Use xInverse for window functions */

  16549. #define SQLITE_GroupByOrder   0x0004   /* GROUPBY cover of ORDERBY */

  16550. #define SQLITE_FactorOutConst 0x0008   /* Constant factoring */

  16551. #define SQLITE_DistinctOpt    0x0010   /* DISTINCT using indexes */

  16552. #define SQLITE_CoverIdxScan   0x0020   /* Covering index scans */

  16553. #define SQLITE_OrderByIdxJoin 0x0040   /* ORDER BY of joins via index */

  16554. #define SQLITE_Transitive     0x0080   /* Transitive constraints */

  16555. #define SQLITE_OmitNoopJoin   0x0100   /* Omit unused tables in joins */

  16556. #define SQLITE_CountOfView    0x0200   /* The count-of-view optimization */

  16557. #define SQLITE_CursorHints    0x0400   /* Add OP_CursorHint opcodes */

  16558. #define SQLITE_Stat34         0x0800   /* Use STAT3 or STAT4 data */

  16559.    /* TH3 expects the Stat34  ^^^^^^ value to be 0x0800.  Don't change it */

  16560. #define SQLITE_PushDown       0x1000   /* The push-down optimization */

  16561. #define SQLITE_SimplifyJoin   0x2000   /* Convert LEFT JOIN to JOIN */

  16562. #define SQLITE_SkipScan       0x4000   /* Skip-scans */

  16563. #define SQLITE_PropagateConst 0x8000   /* The constant propagation opt */

  16564. #define SQLITE_AllOpts        0xffff   /* All optimizations */

  16565. 

  16566. /*

  16567. ** Macros for testing whether or not optimizations are enabled or disabled.

  16568. */

  16569. #define OptimizationDisabled(db, mask)  (((db)->dbOptFlags&(mask))!=0)

  16570. #define OptimizationEnabled(db, mask)   (((db)->dbOptFlags&(mask))==0)

  16571. 

  16572. /*

  16573. ** Return true if it OK to factor constant expressions into the initialization

  16574. ** code. The argument is a Parse object for the code generator.

  16575. */

  16576. #define ConstFactorOk(P) ((P)->okConstFactor)

  16577. 

  16578. /*

  16579. ** Possible values for the sqlite.magic field.

  16580. ** The numbers are obtained at random and have no special meaning, other

  16581. ** than being distinct from one another.

  16582. */

  16583. #define SQLITE_MAGIC_OPEN     0xa029a697  /* Database is open */

  16584. #define SQLITE_MAGIC_CLOSED   0x9f3c2d33  /* Database is closed */

  16585. #define SQLITE_MAGIC_SICK     0x4b771290  /* Error and awaiting close */

  16586. #define SQLITE_MAGIC_BUSY     0xf03b7906  /* Database currently in use */

  16587. #define SQLITE_MAGIC_ERROR    0xb5357930  /* An SQLITE_MISUSE error occurred */

  16588. #define SQLITE_MAGIC_ZOMBIE   0x64cffc7f  /* Close with last statement close */

  16589. 

  16590. /*

  16591. ** Each SQL function is defined by an instance of the following

  16592. ** structure.  For global built-in functions (ex: substr(), max(), count())

  16593. ** a pointer to this structure is held in the sqlite3BuiltinFunctions object.

  16594. ** For per-connection application-defined functions, a pointer to this

  16595. ** structure is held in the db->aHash hash table.

  16596. **

  16597. ** The u.pHash field is used by the global built-ins.  The u.pDestructor

  16598. ** field is used by per-connection app-def functions.

  16599. */

  16600. struct FuncDef {

  16601.   i8 nArg;             /* Number of arguments.  -1 means unlimited */

  16602.   u32 funcFlags;       /* Some combination of SQLITE_FUNC_* */

  16603.   void *pUserData;     /* User data parameter */

  16604.   FuncDef *pNext;      /* Next function with same name */

  16605.   void (*xSFunc)(sqlite3_context*,int,sqlite3_value**); /* func or agg-step */

  16606.   void (*xFinalize)(sqlite3_context*);                  /* Agg finalizer */

  16607.   void (*xValue)(sqlite3_context*);                     /* Current agg value */

  16608.   void (*xInverse)(sqlite3_context*,int,sqlite3_value**); /* inverse agg-step */

  16609.   const char *zName;   /* SQL name of the function. */

  16610.   union {

  16611.     FuncDef *pHash;      /* Next with a different name but the same hash */

  16612.     FuncDestructor *pDestructor;   /* Reference counted destructor function */

  16613.   } u;

  16614. };

  16615. 

  16616. /*

  16617. ** This structure encapsulates a user-function destructor callback (as

  16618. ** configured using create_function_v2()) and a reference counter. When

  16619. ** create_function_v2() is called to create a function with a destructor,

  16620. ** a single object of this type is allocated. FuncDestructor.nRef is set to

  16621. ** the number of FuncDef objects created (either 1 or 3, depending on whether

  16622. ** or not the specified encoding is SQLITE_ANY). The FuncDef.pDestructor

  16623. ** member of each of the new FuncDef objects is set to point to the allocated

  16624. ** FuncDestructor.

  16625. **

  16626. ** Thereafter, when one of the FuncDef objects is deleted, the reference

  16627. ** count on this object is decremented. When it reaches 0, the destructor

  16628. ** is invoked and the FuncDestructor structure freed.

  16629. */

  16630. struct FuncDestructor {

  16631.   int nRef;

  16632.   void (*xDestroy)(void *);

  16633.   void *pUserData;

  16634. };

  16635. 

  16636. /*

  16637. ** Possible values for FuncDef.flags.  Note that the _LENGTH and _TYPEOF

  16638. ** values must correspond to OPFLAG_LENGTHARG and OPFLAG_TYPEOFARG.  And

  16639. ** SQLITE_FUNC_CONSTANT must be the same as SQLITE_DETERMINISTIC.  There

  16640. ** are assert() statements in the code to verify this.

  16641. **

  16642. ** Value constraints (enforced via assert()):

  16643. **     SQLITE_FUNC_MINMAX    ==  NC_MinMaxAgg      == SF_MinMaxAgg

  16644. **     SQLITE_FUNC_LENGTH    ==  OPFLAG_LENGTHARG

  16645. **     SQLITE_FUNC_TYPEOF    ==  OPFLAG_TYPEOFARG

  16646. **     SQLITE_FUNC_CONSTANT  ==  SQLITE_DETERMINISTIC from the API

  16647. **     SQLITE_FUNC_ENCMASK   depends on SQLITE_UTF* macros in the API

  16648. */

  16649. #define SQLITE_FUNC_ENCMASK  0x0003 /* SQLITE_UTF8, SQLITE_UTF16BE or UTF16LE */

  16650. #define SQLITE_FUNC_LIKE     0x0004 /* Candidate for the LIKE optimization */

  16651. #define SQLITE_FUNC_CASE     0x0008 /* Case-sensitive LIKE-type function */

  16652. #define SQLITE_FUNC_EPHEM    0x0010 /* Ephemeral.  Delete with VDBE */

  16653. #define SQLITE_FUNC_NEEDCOLL 0x0020 /* sqlite3GetFuncCollSeq() might be called*/

  16654. #define SQLITE_FUNC_LENGTH   0x0040 /* Built-in length() function */

  16655. #define SQLITE_FUNC_TYPEOF   0x0080 /* Built-in typeof() function */

  16656. #define SQLITE_FUNC_COUNT    0x0100 /* Built-in count(*) aggregate */

  16657. #define SQLITE_FUNC_COALESCE 0x0200 /* Built-in coalesce() or ifnull() */

  16658. #define SQLITE_FUNC_UNLIKELY 0x0400 /* Built-in unlikely() function */

  16659. #define SQLITE_FUNC_CONSTANT 0x0800 /* Constant inputs give a constant output */

  16660. #define SQLITE_FUNC_MINMAX   0x1000 /* True for min() and max() aggregates */

  16661. #define SQLITE_FUNC_SLOCHNG  0x2000 /* "Slow Change". Value constant during a

  16662.                                     ** single query - might change over time */

  16663. #define SQLITE_FUNC_AFFINITY 0x4000 /* Built-in affinity() function */

  16664. #define SQLITE_FUNC_OFFSET   0x8000 /* Built-in sqlite_offset() function */

  16665. #define SQLITE_FUNC_WINDOW   0x00010000 /* Built-in window-only function */

  16666. #define SQLITE_FUNC_INTERNAL 0x00040000 /* For use by NestedParse() only */

  16667. 

  16668. /*

  16669. ** The following three macros, FUNCTION(), LIKEFUNC() and AGGREGATE() are

  16670. ** used to create the initializers for the FuncDef structures.

  16671. **

  16672. **   FUNCTION(zName, nArg, iArg, bNC, xFunc)

  16673. **     Used to create a scalar function definition of a function zName

  16674. **     implemented by C function xFunc that accepts nArg arguments. The

  16675. **     value passed as iArg is cast to a (void*) and made available

  16676. **     as the user-data (sqlite3_user_data()) for the function. If

  16677. **     argument bNC is true, then the SQLITE_FUNC_NEEDCOLL flag is set.

  16678. **

  16679. **   VFUNCTION(zName, nArg, iArg, bNC, xFunc)

  16680. **     Like FUNCTION except it omits the SQLITE_FUNC_CONSTANT flag.

  16681. **

  16682. **   DFUNCTION(zName, nArg, iArg, bNC, xFunc)

  16683. **     Like FUNCTION except it omits the SQLITE_FUNC_CONSTANT flag and

  16684. **     adds the SQLITE_FUNC_SLOCHNG flag.  Used for date & time functions

  16685. **     and functions like sqlite_version() that can change, but not during

  16686. **     a single query.  The iArg is ignored.  The user-data is always set

  16687. **     to a NULL pointer.  The bNC parameter is not used.

  16688. **

  16689. **   PURE_DATE(zName, nArg, iArg, bNC, xFunc)

  16690. **     Used for "pure" date/time functions, this macro is like DFUNCTION

  16691. **     except that it does set the SQLITE_FUNC_CONSTANT flags.  iArg is

  16692. **     ignored and the user-data for these functions is set to an 

  16693. **     arbitrary non-NULL pointer.  The bNC parameter is not used.

  16694. **

  16695. **   AGGREGATE(zName, nArg, iArg, bNC, xStep, xFinal)

  16696. **     Used to create an aggregate function definition implemented by

  16697. **     the C functions xStep and xFinal. The first four parameters

  16698. **     are interpreted in the same way as the first 4 parameters to

  16699. **     FUNCTION().

  16700. **

  16701. **   WFUNCTION(zName, nArg, iArg, xStep, xFinal, xValue, xInverse)

  16702. **     Used to create an aggregate function definition implemented by

  16703. **     the C functions xStep and xFinal. The first four parameters

  16704. **     are interpreted in the same way as the first 4 parameters to

  16705. **     FUNCTION().

  16706. **

  16707. **   LIKEFUNC(zName, nArg, pArg, flags)

  16708. **     Used to create a scalar function definition of a function zName

  16709. **     that accepts nArg arguments and is implemented by a call to C

  16710. **     function likeFunc. Argument pArg is cast to a (void *) and made

  16711. **     available as the function user-data (sqlite3_user_data()). The

  16712. **     FuncDef.flags variable is set to the value passed as the flags

  16713. **     parameter.

  16714. */

  16715. #define FUNCTION(zName, nArg, iArg, bNC, xFunc) \

  16716.   {nArg, SQLITE_FUNC_CONSTANT|SQLITE_UTF8|(bNC*SQLITE_FUNC_NEEDCOLL), \

  16717.    SQLITE_INT_TO_PTR(iArg), 0, xFunc, 0, 0, 0, #zName, {0} }

  16718. #define VFUNCTION(zName, nArg, iArg, bNC, xFunc) \

  16719.   {nArg, SQLITE_UTF8|(bNC*SQLITE_FUNC_NEEDCOLL), \

  16720.    SQLITE_INT_TO_PTR(iArg), 0, xFunc, 0, 0, 0, #zName, {0} }

  16721. #define DFUNCTION(zName, nArg, iArg, bNC, xFunc) \

  16722.   {nArg, SQLITE_FUNC_SLOCHNG|SQLITE_UTF8, \

  16723.    0, 0, xFunc, 0, 0, 0, #zName, {0} }

  16724. #define PURE_DATE(zName, nArg, iArg, bNC, xFunc) \

  16725.   {nArg, SQLITE_FUNC_SLOCHNG|SQLITE_UTF8|SQLITE_FUNC_CONSTANT, \

  16726.    (void*)&sqlite3Config, 0, xFunc, 0, 0, 0, #zName, {0} }

  16727. #define FUNCTION2(zName, nArg, iArg, bNC, xFunc, extraFlags) \

  16728.   {nArg,SQLITE_FUNC_CONSTANT|SQLITE_UTF8|(bNC*SQLITE_FUNC_NEEDCOLL)|extraFlags,\

  16729.    SQLITE_INT_TO_PTR(iArg), 0, xFunc, 0, 0, 0, #zName, {0} }

  16730. #define STR_FUNCTION(zName, nArg, pArg, bNC, xFunc) \

  16731.   {nArg, SQLITE_FUNC_SLOCHNG|SQLITE_UTF8|(bNC*SQLITE_FUNC_NEEDCOLL), \

  16732.    pArg, 0, xFunc, 0, 0, 0, #zName, }

  16733. #define LIKEFUNC(zName, nArg, arg, flags) \

  16734.   {nArg, SQLITE_FUNC_CONSTANT|SQLITE_UTF8|flags, \

  16735.    (void *)arg, 0, likeFunc, 0, 0, 0, #zName, {0} }

  16736. #define AGGREGATE(zName, nArg, arg, nc, xStep, xFinal, xValue) \

  16737.   {nArg, SQLITE_UTF8|(nc*SQLITE_FUNC_NEEDCOLL), \

  16738.    SQLITE_INT_TO_PTR(arg), 0, xStep,xFinal,xValue,0,#zName, {0}}

  16739. #define AGGREGATE2(zName, nArg, arg, nc, xStep, xFinal, extraFlags) \

  16740.   {nArg, SQLITE_UTF8|(nc*SQLITE_FUNC_NEEDCOLL)|extraFlags, \

  16741.    SQLITE_INT_TO_PTR(arg), 0, xStep,xFinal,xFinal,0,#zName, {0}}

  16742. #define WAGGREGATE(zName, nArg, arg, nc, xStep, xFinal, xValue, xInverse, f) \

  16743.   {nArg, SQLITE_UTF8|(nc*SQLITE_FUNC_NEEDCOLL)|f, \

  16744.    SQLITE_INT_TO_PTR(arg), 0, xStep,xFinal,xValue,xInverse,#zName, {0}}

  16745. #define INTERNAL_FUNCTION(zName, nArg, xFunc) \

  16746.   {nArg, SQLITE_FUNC_INTERNAL|SQLITE_UTF8|SQLITE_FUNC_CONSTANT, \

  16747.    0, 0, xFunc, 0, 0, 0, #zName, {0} }

  16748. 

  16749. 

  16750. /*

  16751. ** All current savepoints are stored in a linked list starting at

  16752. ** sqlite3.pSavepoint. The first element in the list is the most recently

  16753. ** opened savepoint. Savepoints are added to the list by the vdbe

  16754. ** OP_Savepoint instruction.

  16755. */

  16756. struct Savepoint {

  16757.   char *zName;                        /* Savepoint name (nul-terminated) */

  16758.   i64 nDeferredCons;                  /* Number of deferred fk violations */

  16759.   i64 nDeferredImmCons;               /* Number of deferred imm fk. */

  16760.   Savepoint *pNext;                   /* Parent savepoint (if any) */

  16761. };

  16762. 

  16763. /*

  16764. ** The following are used as the second parameter to sqlite3Savepoint(),

  16765. ** and as the P1 argument to the OP_Savepoint instruction.

  16766. */

  16767. #define SAVEPOINT_BEGIN      0

  16768. #define SAVEPOINT_RELEASE    1

  16769. #define SAVEPOINT_ROLLBACK   2

  16770. 

  16771. 

  16772. /*

  16773. ** Each SQLite module (virtual table definition) is defined by an

  16774. ** instance of the following structure, stored in the sqlite3.aModule

  16775. ** hash table.

  16776. */

  16777. struct Module {

  16778.   const sqlite3_module *pModule;       /* Callback pointers */

  16779.   const char *zName;                   /* Name passed to create_module() */

  16780.   void *pAux;                          /* pAux passed to create_module() */

  16781.   void (*xDestroy)(void *);            /* Module destructor function */

  16782.   Table *pEpoTab;                      /* Eponymous table for this module */

  16783. };

  16784. 

  16785. /*

  16786. ** information about each column of an SQL table is held in an instance

  16787. ** of this structure.

  16788. */

  16789. struct Column {

  16790.   char *zName;     /* Name of this column, \000, then the type */

  16791.   Expr *pDflt;     /* Default value of this column */

  16792.   char *zColl;     /* Collating sequence.  If NULL, use the default */

  16793.   u8 notNull;      /* An OE_ code for handling a NOT NULL constraint */

  16794.   char affinity;   /* One of the SQLITE_AFF_... values */

  16795.   u8 szEst;        /* Estimated size of value in this column. sizeof(INT)==1 */

  16796.   u8 colFlags;     /* Boolean properties.  See COLFLAG_ defines below */

  16797. };

  16798. 

  16799. /* Allowed values for Column.colFlags:

  16800. */

  16801. #define COLFLAG_PRIMKEY  0x0001    /* Column is part of the primary key */

  16802. #define COLFLAG_HIDDEN   0x0002    /* A hidden column in a virtual table */

  16803. #define COLFLAG_HASTYPE  0x0004    /* Type name follows column name */

  16804. #define COLFLAG_UNIQUE   0x0008    /* Column def contains "UNIQUE" or "PK" */

  16805. #define COLFLAG_SORTERREF 0x0010   /* Use sorter-refs with this column */

  16806. 

  16807. /*

  16808. ** A "Collating Sequence" is defined by an instance of the following

  16809. ** structure. Conceptually, a collating sequence consists of a name and

  16810. ** a comparison routine that defines the order of that sequence.

  16811. **

  16812. ** If CollSeq.xCmp is NULL, it means that the

  16813. ** collating sequence is undefined.  Indices built on an undefined

  16814. ** collating sequence may not be read or written.

  16815. */

  16816. struct CollSeq {

  16817.   char *zName;          /* Name of the collating sequence, UTF-8 encoded */

  16818.   u8 enc;               /* Text encoding handled by xCmp() */

  16819.   void *pUser;          /* First argument to xCmp() */

  16820.   int (*xCmp)(void*,int, const void*, int, const void*);

  16821.   void (*xDel)(void*);  /* Destructor for pUser */

  16822. };

  16823. 

  16824. /*

  16825. ** A sort order can be either ASC or DESC.

  16826. */

  16827. #define SQLITE_SO_ASC       0  /* Sort in ascending order */

  16828. #define SQLITE_SO_DESC      1  /* Sort in ascending order */

  16829. #define SQLITE_SO_UNDEFINED -1 /* No sort order specified */

  16830. 

  16831. /*

  16832. ** Column affinity types.

  16833. **

  16834. ** These used to have mnemonic name like 'i' for SQLITE_AFF_INTEGER and

  16835. ** 't' for SQLITE_AFF_TEXT.  But we can save a little space and improve

  16836. ** the speed a little by numbering the values consecutively.

  16837. **

  16838. ** But rather than start with 0 or 1, we begin with 'A'.  That way,

  16839. ** when multiple affinity types are concatenated into a string and

  16840. ** used as the P4 operand, they will be more readable.

  16841. **

  16842. ** Note also that the numeric types are grouped together so that testing

  16843. ** for a numeric type is a single comparison.  And the BLOB type is first.

  16844. */

  16845. #define SQLITE_AFF_BLOB     'A'

  16846. #define SQLITE_AFF_TEXT     'B'

  16847. #define SQLITE_AFF_NUMERIC  'C'

  16848. #define SQLITE_AFF_INTEGER  'D'

  16849. #define SQLITE_AFF_REAL     'E'

  16850. 

  16851. #define sqlite3IsNumericAffinity(X)  ((X)>=SQLITE_AFF_NUMERIC)

  16852. 

  16853. /*

  16854. ** The SQLITE_AFF_MASK values masks off the significant bits of an

  16855. ** affinity value.

  16856. */

  16857. #define SQLITE_AFF_MASK     0x47

  16858. 

  16859. /*

  16860. ** Additional bit values that can be ORed with an affinity without

  16861. ** changing the affinity.

  16862. **

  16863. ** The SQLITE_NOTNULL flag is a combination of NULLEQ and JUMPIFNULL.

  16864. ** It causes an assert() to fire if either operand to a comparison

  16865. ** operator is NULL.  It is added to certain comparison operators to

  16866. ** prove that the operands are always NOT NULL.

  16867. */

  16868. #define SQLITE_KEEPNULL     0x08  /* Used by vector == or <> */

  16869. #define SQLITE_JUMPIFNULL   0x10  /* jumps if either operand is NULL */

  16870. #define SQLITE_STOREP2      0x20  /* Store result in reg[P2] rather than jump */

  16871. #define SQLITE_NULLEQ       0x80  /* NULL=NULL */

  16872. #define SQLITE_NOTNULL      0x90  /* Assert that operands are never NULL */

  16873. 

  16874. /*

  16875. ** An object of this type is created for each virtual table present in

  16876. ** the database schema.

  16877. **

  16878. ** If the database schema is shared, then there is one instance of this

  16879. ** structure for each database connection (sqlite3*) that uses the shared

  16880. ** schema. This is because each database connection requires its own unique

  16881. ** instance of the sqlite3_vtab* handle used to access the virtual table

  16882. ** implementation. sqlite3_vtab* handles can not be shared between

  16883. ** database connections, even when the rest of the in-memory database

  16884. ** schema is shared, as the implementation often stores the database

  16885. ** connection handle passed to it via the xConnect() or xCreate() method

  16886. ** during initialization internally. This database connection handle may

  16887. ** then be used by the virtual table implementation to access real tables

  16888. ** within the database. So that they appear as part of the callers

  16889. ** transaction, these accesses need to be made via the same database

  16890. ** connection as that used to execute SQL operations on the virtual table.

  16891. **

  16892. ** All VTable objects that correspond to a single table in a shared

  16893. ** database schema are initially stored in a linked-list pointed to by

  16894. ** the Table.pVTable member variable of the corresponding Table object.

  16895. ** When an sqlite3_prepare() operation is required to access the virtual

  16896. ** table, it searches the list for the VTable that corresponds to the

  16897. ** database connection doing the preparing so as to use the correct

  16898. ** sqlite3_vtab* handle in the compiled query.

  16899. **

  16900. ** When an in-memory Table object is deleted (for example when the

  16901. ** schema is being reloaded for some reason), the VTable objects are not

  16902. ** deleted and the sqlite3_vtab* handles are not xDisconnect()ed

  16903. ** immediately. Instead, they are moved from the Table.pVTable list to

  16904. ** another linked list headed by the sqlite3.pDisconnect member of the

  16905. ** corresponding sqlite3 structure. They are then deleted/xDisconnected

  16906. ** next time a statement is prepared using said sqlite3*. This is done

  16907. ** to avoid deadlock issues involving multiple sqlite3.mutex mutexes.

  16908. ** Refer to comments above function sqlite3VtabUnlockList() for an

  16909. ** explanation as to why it is safe to add an entry to an sqlite3.pDisconnect

  16910. ** list without holding the corresponding sqlite3.mutex mutex.

  16911. **

  16912. ** The memory for objects of this type is always allocated by

  16913. ** sqlite3DbMalloc(), using the connection handle stored in VTable.db as

  16914. ** the first argument.

  16915. */

  16916. struct VTable {

  16917.   sqlite3 *db;              /* Database connection associated with this table */

  16918.   Module *pMod;             /* Pointer to module implementation */

  16919.   sqlite3_vtab *pVtab;      /* Pointer to vtab instance */

  16920.   int nRef;                 /* Number of pointers to this structure */

  16921.   u8 bConstraint;           /* True if constraints are supported */

  16922.   int iSavepoint;           /* Depth of the SAVEPOINT stack */

  16923.   VTable *pNext;            /* Next in linked list (see above) */

  16924. };

  16925. 

  16926. /*

  16927. ** The schema for each SQL table and view is represented in memory

  16928. ** by an instance of the following structure.

  16929. */

  16930. struct Table {

  16931.   char *zName;         /* Name of the table or view */

  16932.   Column *aCol;        /* Information about each column */

  16933.   Index *pIndex;       /* List of SQL indexes on this table. */

  16934.   Select *pSelect;     /* NULL for tables.  Points to definition if a view. */

  16935.   FKey *pFKey;         /* Linked list of all foreign keys in this table */

  16936.   char *zColAff;       /* String defining the affinity of each column */

  16937.   ExprList *pCheck;    /* All CHECK constraints */

  16938.                        /*   ... also used as column name list in a VIEW */

  16939.   int tnum;            /* Root BTree page for this table */

  16940.   u32 nTabRef;         /* Number of pointers to this Table */

  16941.   u32 tabFlags;        /* Mask of TF_* values */

  16942.   i16 iPKey;           /* If not negative, use aCol[iPKey] as the rowid */

  16943.   i16 nCol;            /* Number of columns in this table */

  16944.   LogEst nRowLogEst;   /* Estimated rows in table - from sqlite_stat1 table */

  16945.   LogEst szTabRow;     /* Estimated size of each table row in bytes */

  16946. #ifdef SQLITE_ENABLE_COSTMULT

  16947.   LogEst costMult;     /* Cost multiplier for using this table */

  16948. #endif

  16949.   u8 keyConf;          /* What to do in case of uniqueness conflict on iPKey */

  16950. #ifndef SQLITE_OMIT_ALTERTABLE

  16951.   int addColOffset;    /* Offset in CREATE TABLE stmt to add a new column */

  16952. #endif

  16953. #ifndef SQLITE_OMIT_VIRTUALTABLE

  16954.   int nModuleArg;      /* Number of arguments to the module */

  16955.   char **azModuleArg;  /* 0: module 1: schema 2: vtab name 3...: args */

  16956.   VTable *pVTable;     /* List of VTable objects. */

  16957. #endif

  16958.   Trigger *pTrigger;   /* List of triggers stored in pSchema */

  16959.   Schema *pSchema;     /* Schema that contains this table */

  16960.   Table *pNextZombie;  /* Next on the Parse.pZombieTab list */

  16961. };

  16962. 

  16963. /*

  16964. ** Allowed values for Table.tabFlags.

  16965. **

  16966. ** TF_OOOHidden applies to tables or view that have hidden columns that are

  16967. ** followed by non-hidden columns.  Example:  "CREATE VIRTUAL TABLE x USING

  16968. ** vtab1(a HIDDEN, b);".  Since "b" is a non-hidden column but "a" is hidden,

  16969. ** the TF_OOOHidden attribute would apply in this case.  Such tables require

  16970. ** special handling during INSERT processing.

  16971. */

  16972. #define TF_Readonly        0x0001    /* Read-only system table */

  16973. #define TF_Ephemeral       0x0002    /* An ephemeral table */

  16974. #define TF_HasPrimaryKey   0x0004    /* Table has a primary key */

  16975. #define TF_Autoincrement   0x0008    /* Integer primary key is autoincrement */

  16976. #define TF_HasStat1        0x0010    /* nRowLogEst set from sqlite_stat1 */

  16977. #define TF_WithoutRowid    0x0020    /* No rowid.  PRIMARY KEY is the key */

  16978. #define TF_NoVisibleRowid  0x0040    /* No user-visible "rowid" column */

  16979. #define TF_OOOHidden       0x0080    /* Out-of-Order hidden columns */

  16980. #define TF_StatsUsed       0x0100    /* Query planner decisions affected by

  16981.                                      ** Index.aiRowLogEst[] values */

  16982. #define TF_HasNotNull      0x0200    /* Contains NOT NULL constraints */

  16983. #define TF_Shadow          0x0400    /* True for a shadow table */

  16984. 

  16985. /*

  16986. ** Test to see whether or not a table is a virtual table.  This is

  16987. ** done as a macro so that it will be optimized out when virtual

  16988. ** table support is omitted from the build.

  16989. */

  16990. #ifndef SQLITE_OMIT_VIRTUALTABLE

  16991. #  define IsVirtual(X)      ((X)->nModuleArg)

  16992. #else

  16993. #  define IsVirtual(X)      0

  16994. #endif

  16995. 

  16996. /*

  16997. ** Macros to determine if a column is hidden.  IsOrdinaryHiddenColumn()

  16998. ** only works for non-virtual tables (ordinary tables and views) and is

  16999. ** always false unless SQLITE_ENABLE_HIDDEN_COLUMNS is defined.  The

  17000. ** IsHiddenColumn() macro is general purpose.

  17001. */

  17002. #if defined(SQLITE_ENABLE_HIDDEN_COLUMNS)

  17003. #  define IsHiddenColumn(X)         (((X)->colFlags & COLFLAG_HIDDEN)!=0)

  17004. #  define IsOrdinaryHiddenColumn(X) (((X)->colFlags & COLFLAG_HIDDEN)!=0)

  17005. #elif !defined(SQLITE_OMIT_VIRTUALTABLE)

  17006. #  define IsHiddenColumn(X)         (((X)->colFlags & COLFLAG_HIDDEN)!=0)

  17007. #  define IsOrdinaryHiddenColumn(X) 0

  17008. #else

  17009. #  define IsHiddenColumn(X)         0

  17010. #  define IsOrdinaryHiddenColumn(X) 0

  17011. #endif

  17012. 

  17013. 

  17014. /* Does the table have a rowid */

  17015. #define HasRowid(X)     (((X)->tabFlags & TF_WithoutRowid)==0)

  17016. #define VisibleRowid(X) (((X)->tabFlags & TF_NoVisibleRowid)==0)

  17017. 

  17018. /*

  17019. ** Each foreign key constraint is an instance of the following structure.

  17020. **

  17021. ** A foreign key is associated with two tables.  The "from" table is

  17022. ** the table that contains the REFERENCES clause that creates the foreign

  17023. ** key.  The "to" table is the table that is named in the REFERENCES clause.

  17024. ** Consider this example:

  17025. **

  17026. **     CREATE TABLE ex1(

  17027. **       a INTEGER PRIMARY KEY,

  17028. **       b INTEGER CONSTRAINT fk1 REFERENCES ex2(x)

  17029. **     );

  17030. **

  17031. ** For foreign key "fk1", the from-table is "ex1" and the to-table is "ex2".

  17032. ** Equivalent names:

  17033. **

  17034. **     from-table == child-table

  17035. **       to-table == parent-table

  17036. **

  17037. ** Each REFERENCES clause generates an instance of the following structure

  17038. ** which is attached to the from-table.  The to-table need not exist when

  17039. ** the from-table is created.  The existence of the to-table is not checked.

  17040. **

  17041. ** The list of all parents for child Table X is held at X.pFKey.

  17042. **

  17043. ** A list of all children for a table named Z (which might not even exist)

  17044. ** is held in Schema.fkeyHash with a hash key of Z.

  17045. */

  17046. struct FKey {

  17047.   Table *pFrom;     /* Table containing the REFERENCES clause (aka: Child) */

  17048.   FKey *pNextFrom;  /* Next FKey with the same in pFrom. Next parent of pFrom */

  17049.   char *zTo;        /* Name of table that the key points to (aka: Parent) */

  17050.   FKey *pNextTo;    /* Next with the same zTo. Next child of zTo. */

  17051.   FKey *pPrevTo;    /* Previous with the same zTo */

  17052.   int nCol;         /* Number of columns in this key */

  17053.   /* EV: R-30323-21917 */

  17054.   u8 isDeferred;       /* True if constraint checking is deferred till COMMIT */

  17055.   u8 aAction[2];        /* ON DELETE and ON UPDATE actions, respectively */

  17056.   Trigger *apTrigger[2];/* Triggers for aAction[] actions */

  17057.   struct sColMap {      /* Mapping of columns in pFrom to columns in zTo */

  17058.     int iFrom;            /* Index of column in pFrom */

  17059.     char *zCol;           /* Name of column in zTo.  If NULL use PRIMARY KEY */

  17060.   } aCol[1];            /* One entry for each of nCol columns */

  17061. };

  17062. 

  17063. /*

  17064. ** SQLite supports many different ways to resolve a constraint

  17065. ** error.  ROLLBACK processing means that a constraint violation

  17066. ** causes the operation in process to fail and for the current transaction

  17067. ** to be rolled back.  ABORT processing means the operation in process

  17068. ** fails and any prior changes from that one operation are backed out,

  17069. ** but the transaction is not rolled back.  FAIL processing means that

  17070. ** the operation in progress stops and returns an error code.  But prior

  17071. ** changes due to the same operation are not backed out and no rollback

  17072. ** occurs.  IGNORE means that the particular row that caused the constraint

  17073. ** error is not inserted or updated.  Processing continues and no error

  17074. ** is returned.  REPLACE means that preexisting database rows that caused

  17075. ** a UNIQUE constraint violation are removed so that the new insert or

  17076. ** update can proceed.  Processing continues and no error is reported.

  17077. **

  17078. ** RESTRICT, SETNULL, and CASCADE actions apply only to foreign keys.

  17079. ** RESTRICT is the same as ABORT for IMMEDIATE foreign keys and the

  17080. ** same as ROLLBACK for DEFERRED keys.  SETNULL means that the foreign

  17081. ** key is set to NULL.  CASCADE means that a DELETE or UPDATE of the

  17082. ** referenced table row is propagated into the row that holds the

  17083. ** foreign key.

  17084. **

  17085. ** The following symbolic values are used to record which type

  17086. ** of action to take.

  17087. */

  17088. #define OE_None     0   /* There is no constraint to check */

  17089. #define OE_Rollback 1   /* Fail the operation and rollback the transaction */

  17090. #define OE_Abort    2   /* Back out changes but do no rollback transaction */

  17091. #define OE_Fail     3   /* Stop the operation but leave all prior changes */

  17092. #define OE_Ignore   4   /* Ignore the error. Do not do the INSERT or UPDATE */

  17093. #define OE_Replace  5   /* Delete existing record, then do INSERT or UPDATE */

  17094. #define OE_Update   6   /* Process as a DO UPDATE in an upsert */

  17095. #define OE_Restrict 7   /* OE_Abort for IMMEDIATE, OE_Rollback for DEFERRED */

  17096. #define OE_SetNull  8   /* Set the foreign key value to NULL */

  17097. #define OE_SetDflt  9   /* Set the foreign key value to its default */

  17098. #define OE_Cascade  10  /* Cascade the changes */

  17099. #define OE_Default  11  /* Do whatever the default action is */

  17100. 

  17101. 

  17102. /*

  17103. ** An instance of the following structure is passed as the first

  17104. ** argument to sqlite3VdbeKeyCompare and is used to control the

  17105. ** comparison of the two index keys.

  17106. **

  17107. ** Note that aSortOrder[] and aColl[] have nField+1 slots.  There

  17108. ** are nField slots for the columns of an index then one extra slot

  17109. ** for the rowid at the end.

  17110. */

  17111. struct KeyInfo {

  17112.   u32 nRef;           /* Number of references to this KeyInfo object */

  17113.   u8 enc;             /* Text encoding - one of the SQLITE_UTF* values */

  17114.   u16 nKeyField;      /* Number of key columns in the index */

  17115.   u16 nAllField;      /* Total columns, including key plus others */

  17116.   sqlite3 *db;        /* The database connection */

  17117.   u8 *aSortOrder;     /* Sort order for each column. */

  17118.   CollSeq *aColl[1];  /* Collating sequence for each term of the key */

  17119. };

  17120. 

  17121. /*

  17122. ** This object holds a record which has been parsed out into individual

  17123. ** fields, for the purposes of doing a comparison.

  17124. **

  17125. ** A record is an object that contains one or more fields of data.

  17126. ** Records are used to store the content of a table row and to store

  17127. ** the key of an index.  A blob encoding of a record is created by

  17128. ** the OP_MakeRecord opcode of the VDBE and is disassembled by the

  17129. ** OP_Column opcode.

  17130. **

  17131. ** An instance of this object serves as a "key" for doing a search on

  17132. ** an index b+tree. The goal of the search is to find the entry that

  17133. ** is closed to the key described by this object.  This object might hold

  17134. ** just a prefix of the key.  The number of fields is given by

  17135. ** pKeyInfo->nField.

  17136. **

  17137. ** The r1 and r2 fields are the values to return if this key is less than

  17138. ** or greater than a key in the btree, respectively.  These are normally

  17139. ** -1 and +1 respectively, but might be inverted to +1 and -1 if the b-tree

  17140. ** is in DESC order.

  17141. **

  17142. ** The key comparison functions actually return default_rc when they find

  17143. ** an equals comparison.  default_rc can be -1, 0, or +1.  If there are

  17144. ** multiple entries in the b-tree with the same key (when only looking

  17145. ** at the first pKeyInfo->nFields,) then default_rc can be set to -1 to

  17146. ** cause the search to find the last match, or +1 to cause the search to

  17147. ** find the first match.

  17148. **

  17149. ** The key comparison functions will set eqSeen to true if they ever

  17150. ** get and equal results when comparing this structure to a b-tree record.

  17151. ** When default_rc!=0, the search might end up on the record immediately

  17152. ** before the first match or immediately after the last match.  The

  17153. ** eqSeen field will indicate whether or not an exact match exists in the

  17154. ** b-tree.

  17155. */

  17156. struct UnpackedRecord {

  17157.   KeyInfo *pKeyInfo;  /* Collation and sort-order information */

  17158.   Mem *aMem;          /* Values */

  17159.   u16 nField;         /* Number of entries in apMem[] */

  17160.   i8 default_rc;      /* Comparison result if keys are equal */

  17161.   u8 errCode;         /* Error detected by xRecordCompare (CORRUPT or NOMEM) */

  17162.   i8 r1;              /* Value to return if (lhs < rhs) */

  17163.   i8 r2;              /* Value to return if (lhs > rhs) */

  17164.   u8 eqSeen;          /* True if an equality comparison has been seen */

  17165. };

  17166. 

  17167. 

  17168. /*

  17169. ** Each SQL index is represented in memory by an

  17170. ** instance of the following structure.

  17171. **

  17172. ** The columns of the table that are to be indexed are described

  17173. ** by the aiColumn[] field of this structure.  For example, suppose

  17174. ** we have the following table and index:

  17175. **

  17176. **     CREATE TABLE Ex1(c1 int, c2 int, c3 text);

  17177. **     CREATE INDEX Ex2 ON Ex1(c3,c1);

  17178. **

  17179. ** In the Table structure describing Ex1, nCol==3 because there are

  17180. ** three columns in the table.  In the Index structure describing

  17181. ** Ex2, nColumn==2 since 2 of the 3 columns of Ex1 are indexed.

  17182. ** The value of aiColumn is {2, 0}.  aiColumn[0]==2 because the

  17183. ** first column to be indexed (c3) has an index of 2 in Ex1.aCol[].

  17184. ** The second column to be indexed (c1) has an index of 0 in

  17185. ** Ex1.aCol[], hence Ex2.aiColumn[1]==0.

  17186. **

  17187. ** The Index.onError field determines whether or not the indexed columns

  17188. ** must be unique and what to do if they are not.  When Index.onError=OE_None,

  17189. ** it means this is not a unique index.  Otherwise it is a unique index

  17190. ** and the value of Index.onError indicate the which conflict resolution

  17191. ** algorithm to employ whenever an attempt is made to insert a non-unique

  17192. ** element.

  17193. **

  17194. ** While parsing a CREATE TABLE or CREATE INDEX statement in order to

  17195. ** generate VDBE code (as opposed to parsing one read from an sqlite_master

  17196. ** table as part of parsing an existing database schema), transient instances

  17197. ** of this structure may be created. In this case the Index.tnum variable is

  17198. ** used to store the address of a VDBE instruction, not a database page

  17199. ** number (it cannot - the database page is not allocated until the VDBE

  17200. ** program is executed). See convertToWithoutRowidTable() for details.

  17201. */

  17202. struct Index {

  17203.   char *zName;             /* Name of this index */

  17204.   i16 *aiColumn;           /* Which columns are used by this index.  1st is 0 */

  17205.   LogEst *aiRowLogEst;     /* From ANALYZE: Est. rows selected by each column */

  17206.   Table *pTable;           /* The SQL table being indexed */

  17207.   char *zColAff;           /* String defining the affinity of each column */

  17208.   Index *pNext;            /* The next index associated with the same table */

  17209.   Schema *pSchema;         /* Schema containing this index */

  17210.   u8 *aSortOrder;          /* for each column: True==DESC, False==ASC */

  17211.   const char **azColl;     /* Array of collation sequence names for index */

  17212.   Expr *pPartIdxWhere;     /* WHERE clause for partial indices */

  17213.   ExprList *aColExpr;      /* Column expressions */

  17214.   int tnum;                /* DB Page containing root of this index */

  17215.   LogEst szIdxRow;         /* Estimated average row size in bytes */

  17216.   u16 nKeyCol;             /* Number of columns forming the key */

  17217.   u16 nColumn;             /* Number of columns stored in the index */

  17218.   u8 onError;              /* OE_Abort, OE_Ignore, OE_Replace, or OE_None */

  17219.   unsigned idxType:2;      /* 0:Normal 1:UNIQUE, 2:PRIMARY KEY, 3:IPK */

  17220.   unsigned bUnordered:1;   /* Use this index for == or IN queries only */

  17221.   unsigned uniqNotNull:1;  /* True if UNIQUE and NOT NULL for all columns */

  17222.   unsigned isResized:1;    /* True if resizeIndexObject() has been called */

  17223.   unsigned isCovering:1;   /* True if this is a covering index */

  17224.   unsigned noSkipScan:1;   /* Do not try to use skip-scan if true */

  17225.   unsigned hasStat1:1;     /* aiRowLogEst values come from sqlite_stat1 */

  17226.   unsigned bNoQuery:1;     /* Do not use this index to optimize queries */

  17227.   unsigned bAscKeyBug:1;   /* True if the bba7b69f9849b5bf bug applies */

  17228. #ifdef SQLITE_ENABLE_STAT3_OR_STAT4

  17229.   int nSample;             /* Number of elements in aSample[] */

  17230.   int nSampleCol;          /* Size of IndexSample.anEq[] and so on */

  17231.   tRowcnt *aAvgEq;         /* Average nEq values for keys not in aSample */

  17232.   IndexSample *aSample;    /* Samples of the left-most key */

  17233.   tRowcnt *aiRowEst;       /* Non-logarithmic stat1 data for this index */

  17234.   tRowcnt nRowEst0;        /* Non-logarithmic number of rows in the index */

  17235. #endif

  17236.   Bitmask colNotIdxed;     /* 0 for unindexed columns in pTab */

  17237. };

  17238. 

  17239. /*

  17240. ** Allowed values for Index.idxType

  17241. */

  17242. #define SQLITE_IDXTYPE_APPDEF      0   /* Created using CREATE INDEX */

  17243. #define SQLITE_IDXTYPE_UNIQUE      1   /* Implements a UNIQUE constraint */

  17244. #define SQLITE_IDXTYPE_PRIMARYKEY  2   /* Is the PRIMARY KEY for the table */

  17245. #define SQLITE_IDXTYPE_IPK         3   /* INTEGER PRIMARY KEY index */

  17246. 

  17247. /* Return true if index X is a PRIMARY KEY index */

  17248. #define IsPrimaryKeyIndex(X)  ((X)->idxType==SQLITE_IDXTYPE_PRIMARYKEY)

  17249. 

  17250. /* Return true if index X is a UNIQUE index */

  17251. #define IsUniqueIndex(X)      ((X)->onError!=OE_None)

  17252. 

  17253. /* The Index.aiColumn[] values are normally positive integer.  But

  17254. ** there are some negative values that have special meaning:

  17255. */

  17256. #define XN_ROWID     (-1)     /* Indexed column is the rowid */

  17257. #define XN_EXPR      (-2)     /* Indexed column is an expression */

  17258. 

  17259. /*

  17260. ** Each sample stored in the sqlite_stat3 table is represented in memory

  17261. ** using a structure of this type.  See documentation at the top of the

  17262. ** analyze.c source file for additional information.

  17263. */

  17264. struct IndexSample {

  17265.   void *p;          /* Pointer to sampled record */

  17266.   int n;            /* Size of record in bytes */

  17267.   tRowcnt *anEq;    /* Est. number of rows where the key equals this sample */

  17268.   tRowcnt *anLt;    /* Est. number of rows where key is less than this sample */

  17269.   tRowcnt *anDLt;   /* Est. number of distinct keys less than this sample */

  17270. };

  17271. 

  17272. /*

  17273. ** Possible values to use within the flags argument to sqlite3GetToken().

  17274. */

  17275. #define SQLITE_TOKEN_QUOTED    0x1 /* Token is a quoted identifier. */

  17276. #define SQLITE_TOKEN_KEYWORD   0x2 /* Token is a keyword. */

  17277. 

  17278. /*

  17279. ** Each token coming out of the lexer is an instance of

  17280. ** this structure.  Tokens are also used as part of an expression.

  17281. **

  17282. ** The memory that "z" points to is owned by other objects.  Take care

  17283. ** that the owner of the "z" string does not deallocate the string before

  17284. ** the Token goes out of scope!  Very often, the "z" points to some place

  17285. ** in the middle of the Parse.zSql text.  But it might also point to a

  17286. ** static string.

  17287. */

  17288. struct Token {

  17289.   const char *z;     /* Text of the token.  Not NULL-terminated! */

  17290.   unsigned int n;    /* Number of characters in this token */

  17291. };

  17292. 

  17293. /*

  17294. ** An instance of this structure contains information needed to generate

  17295. ** code for a SELECT that contains aggregate functions.

  17296. **

  17297. ** If Expr.op==TK_AGG_COLUMN or TK_AGG_FUNCTION then Expr.pAggInfo is a

  17298. ** pointer to this structure.  The Expr.iColumn field is the index in

  17299. ** AggInfo.aCol[] or AggInfo.aFunc[] of information needed to generate

  17300. ** code for that node.

  17301. **

  17302. ** AggInfo.pGroupBy and AggInfo.aFunc.pExpr point to fields within the

  17303. ** original Select structure that describes the SELECT statement.  These

  17304. ** fields do not need to be freed when deallocating the AggInfo structure.

  17305. */

  17306. struct AggInfo {

  17307.   u8 directMode;          /* Direct rendering mode means take data directly

  17308.                           ** from source tables rather than from accumulators */

  17309.   u8 useSortingIdx;       /* In direct mode, reference the sorting index rather

  17310.                           ** than the source table */

  17311.   int sortingIdx;         /* Cursor number of the sorting index */

  17312.   int sortingIdxPTab;     /* Cursor number of pseudo-table */

  17313.   int nSortingColumn;     /* Number of columns in the sorting index */

  17314.   int mnReg, mxReg;       /* Range of registers allocated for aCol and aFunc */

  17315.   ExprList *pGroupBy;     /* The group by clause */

  17316.   struct AggInfo_col {    /* For each column used in source tables */

  17317.     Table *pTab;             /* Source table */

  17318.     int iTable;              /* Cursor number of the source table */

  17319.     int iColumn;             /* Column number within the source table */

  17320.     int iSorterColumn;       /* Column number in the sorting index */

  17321.     int iMem;                /* Memory location that acts as accumulator */

  17322.     Expr *pExpr;             /* The original expression */

  17323.   } *aCol;

  17324.   int nColumn;            /* Number of used entries in aCol[] */

  17325.   int nAccumulator;       /* Number of columns that show through to the output.

  17326.                           ** Additional columns are used only as parameters to

  17327.                           ** aggregate functions */

  17328.   struct AggInfo_func {   /* For each aggregate function */

  17329.     Expr *pExpr;             /* Expression encoding the function */

  17330.     FuncDef *pFunc;          /* The aggregate function implementation */

  17331.     int iMem;                /* Memory location that acts as accumulator */

  17332.     int iDistinct;           /* Ephemeral table used to enforce DISTINCT */

  17333.   } *aFunc;

  17334.   int nFunc;              /* Number of entries in aFunc[] */

  17335. };

  17336. 

  17337. /*

  17338. ** The datatype ynVar is a signed integer, either 16-bit or 32-bit.

  17339. ** Usually it is 16-bits.  But if SQLITE_MAX_VARIABLE_NUMBER is greater

  17340. ** than 32767 we have to make it 32-bit.  16-bit is preferred because

  17341. ** it uses less memory in the Expr object, which is a big memory user

  17342. ** in systems with lots of prepared statements.  And few applications

  17343. ** need more than about 10 or 20 variables.  But some extreme users want

  17344. ** to have prepared statements with over 32767 variables, and for them

  17345. ** the option is available (at compile-time).

  17346. */

  17347. #if SQLITE_MAX_VARIABLE_NUMBER<=32767

  17348. typedef i16 ynVar;

  17349. #else

  17350. typedef int ynVar;

  17351. #endif

  17352. 

  17353. /*

  17354. ** Each node of an expression in the parse tree is an instance

  17355. ** of this structure.

  17356. **

  17357. ** Expr.op is the opcode. The integer parser token codes are reused

  17358. ** as opcodes here. For example, the parser defines TK_GE to be an integer

  17359. ** code representing the ">=" operator. This same integer code is reused

  17360. ** to represent the greater-than-or-equal-to operator in the expression

  17361. ** tree.

  17362. **

  17363. ** If the expression is an SQL literal (TK_INTEGER, TK_FLOAT, TK_BLOB,

  17364. ** or TK_STRING), then Expr.token contains the text of the SQL literal. If

  17365. ** the expression is a variable (TK_VARIABLE), then Expr.token contains the

  17366. ** variable name. Finally, if the expression is an SQL function (TK_FUNCTION),

  17367. ** then Expr.token contains the name of the function.

  17368. **

  17369. ** Expr.pRight and Expr.pLeft are the left and right subexpressions of a

  17370. ** binary operator. Either or both may be NULL.

  17371. **

  17372. ** Expr.x.pList is a list of arguments if the expression is an SQL function,

  17373. ** a CASE expression or an IN expression of the form "<lhs> IN (<y>, <z>...)".

  17374. ** Expr.x.pSelect is used if the expression is a sub-select or an expression of

  17375. ** the form "<lhs> IN (SELECT ...)". If the EP_xIsSelect bit is set in the

  17376. ** Expr.flags mask, then Expr.x.pSelect is valid. Otherwise, Expr.x.pList is

  17377. ** valid.

  17378. **

  17379. ** An expression of the form ID or ID.ID refers to a column in a table.

  17380. ** For such expressions, Expr.op is set to TK_COLUMN and Expr.iTable is

  17381. ** the integer cursor number of a VDBE cursor pointing to that table and

  17382. ** Expr.iColumn is the column number for the specific column.  If the

  17383. ** expression is used as a result in an aggregate SELECT, then the

  17384. ** value is also stored in the Expr.iAgg column in the aggregate so that

  17385. ** it can be accessed after all aggregates are computed.

  17386. **

  17387. ** If the expression is an unbound variable marker (a question mark

  17388. ** character '?' in the original SQL) then the Expr.iTable holds the index

  17389. ** number for that variable.

  17390. **

  17391. ** If the expression is a subquery then Expr.iColumn holds an integer

  17392. ** register number containing the result of the subquery.  If the

  17393. ** subquery gives a constant result, then iTable is -1.  If the subquery

  17394. ** gives a different answer at different times during statement processing

  17395. ** then iTable is the address of a subroutine that computes the subquery.

  17396. **

  17397. ** If the Expr is of type OP_Column, and the table it is selecting from

  17398. ** is a disk table or the "old.*" pseudo-table, then pTab points to the

  17399. ** corresponding table definition.

  17400. **

  17401. ** ALLOCATION NOTES:

  17402. **

  17403. ** Expr objects can use a lot of memory space in database schema.  To

  17404. ** help reduce memory requirements, sometimes an Expr object will be

  17405. ** truncated.  And to reduce the number of memory allocations, sometimes

  17406. ** two or more Expr objects will be stored in a single memory allocation,

  17407. ** together with Expr.zToken strings.

  17408. **

  17409. ** If the EP_Reduced and EP_TokenOnly flags are set when

  17410. ** an Expr object is truncated.  When EP_Reduced is set, then all

  17411. ** the child Expr objects in the Expr.pLeft and Expr.pRight subtrees

  17412. ** are contained within the same memory allocation.  Note, however, that

  17413. ** the subtrees in Expr.x.pList or Expr.x.pSelect are always separately

  17414. ** allocated, regardless of whether or not EP_Reduced is set.

  17415. */

  17416. struct Expr {

  17417.   u8 op;                 /* Operation performed by this node */

  17418.   char affinity;         /* The affinity of the column or 0 if not a column */

  17419.   u32 flags;             /* Various flags.  EP_* See below */

  17420.   union {

  17421.     char *zToken;          /* Token value. Zero terminated and dequoted */

  17422.     int iValue;            /* Non-negative integer value if EP_IntValue */

  17423.   } u;

  17424. 

  17425.   /* If the EP_TokenOnly flag is set in the Expr.flags mask, then no

  17426.   ** space is allocated for the fields below this point. An attempt to

  17427.   ** access them will result in a segfault or malfunction.

  17428.   *********************************************************************/

  17429. 

  17430.   Expr *pLeft;           /* Left subnode */

  17431.   Expr *pRight;          /* Right subnode */

  17432.   union {

  17433.     ExprList *pList;     /* op = IN, EXISTS, SELECT, CASE, FUNCTION, BETWEEN */

  17434.     Select *pSelect;     /* EP_xIsSelect and op = IN, EXISTS, SELECT */

  17435.   } x;

  17436. 

  17437.   /* If the EP_Reduced flag is set in the Expr.flags mask, then no

  17438.   ** space is allocated for the fields below this point. An attempt to

  17439.   ** access them will result in a segfault or malfunction.

  17440.   *********************************************************************/

  17441. 

  17442. #if SQLITE_MAX_EXPR_DEPTH>0

  17443.   int nHeight;           /* Height of the tree headed by this node */

  17444. #endif

  17445.   int iTable;            /* TK_COLUMN: cursor number of table holding column

  17446.                          ** TK_REGISTER: register number

  17447.                          ** TK_TRIGGER: 1 -> new, 0 -> old

  17448.                          ** EP_Unlikely:  134217728 times likelihood

  17449.                          ** TK_SELECT: 1st register of result vector */

  17450.   ynVar iColumn;         /* TK_COLUMN: column index.  -1 for rowid.

  17451.                          ** TK_VARIABLE: variable number (always >= 1).

  17452.                          ** TK_SELECT_COLUMN: column of the result vector */

  17453.   i16 iAgg;              /* Which entry in pAggInfo->aCol[] or ->aFunc[] */

  17454.   i16 iRightJoinTable;   /* If EP_FromJoin, the right table of the join */

  17455.   u8 op2;                /* TK_REGISTER/TK_TRUTH: original value of Expr.op

  17456.                          ** TK_COLUMN: the value of p5 for OP_Column

  17457.                          ** TK_AGG_FUNCTION: nesting depth */

  17458.   AggInfo *pAggInfo;     /* Used by TK_AGG_COLUMN and TK_AGG_FUNCTION */

  17459.   union {

  17460.     Table *pTab;           /* TK_COLUMN: Table containing column. Can be NULL

  17461.                            ** for a column of an index on an expression */

  17462.     Window *pWin;          /* TK_FUNCTION: Window definition for the func */

  17463.     struct {               /* TK_IN, TK_SELECT, and TK_EXISTS */

  17464.       int iAddr;             /* Subroutine entry address */

  17465.       int regReturn;         /* Register used to hold return address */

  17466.     } sub;

  17467.   } y;

  17468. };

  17469. 

  17470. /*

  17471. ** The following are the meanings of bits in the Expr.flags field.

  17472. ** Value restrictions:

  17473. **

  17474. **          EP_Agg == NC_HasAgg == SF_HasAgg

  17475. **          EP_Win == NC_HasWin

  17476. */

  17477. #define EP_FromJoin  0x000001 /* Originates in ON/USING clause of outer join */

  17478. #define EP_Distinct  0x000002 /* Aggregate function with DISTINCT keyword */

  17479. #define EP_HasFunc   0x000004 /* Contains one or more functions of any kind */

  17480. #define EP_FixedCol  0x000008 /* TK_Column with a known fixed value */

  17481. #define EP_Agg       0x000010 /* Contains one or more aggregate functions */

  17482. #define EP_VarSelect 0x000020 /* pSelect is correlated, not constant */

  17483. #define EP_DblQuoted 0x000040 /* token.z was originally in "..." */

  17484. #define EP_InfixFunc 0x000080 /* True for an infix function: LIKE, GLOB, etc */

  17485. #define EP_Collate   0x000100 /* Tree contains a TK_COLLATE operator */

  17486. #define EP_Generic   0x000200 /* Ignore COLLATE or affinity on this tree */

  17487. #define EP_IntValue  0x000400 /* Integer value contained in u.iValue */

  17488. #define EP_xIsSelect 0x000800 /* x.pSelect is valid (otherwise x.pList is) */

  17489. #define EP_Skip      0x001000 /* Operator does not contribute to affinity */

  17490. #define EP_Reduced   0x002000 /* Expr struct EXPR_REDUCEDSIZE bytes only */

  17491. #define EP_TokenOnly 0x004000 /* Expr struct EXPR_TOKENONLYSIZE bytes only */

  17492. #define EP_Win       0x008000 /* Contains window functions */

  17493. #define EP_MemToken  0x010000 /* Need to sqlite3DbFree() Expr.zToken */

  17494. #define EP_NoReduce  0x020000 /* Cannot EXPRDUP_REDUCE this Expr */

  17495. #define EP_Unlikely  0x040000 /* unlikely() or likelihood() function */

  17496. #define EP_ConstFunc 0x080000 /* A SQLITE_FUNC_CONSTANT or _SLOCHNG function */

  17497. #define EP_CanBeNull 0x100000 /* Can be null despite NOT NULL constraint */

  17498. #define EP_Subquery  0x200000 /* Tree contains a TK_SELECT operator */

  17499. #define EP_Alias     0x400000 /* Is an alias for a result set column */

  17500. #define EP_Leaf      0x800000 /* Expr.pLeft, .pRight, .u.pSelect all NULL */

  17501. #define EP_WinFunc  0x1000000 /* TK_FUNCTION with Expr.y.pWin set */

  17502. #define EP_Subrtn   0x2000000 /* Uses Expr.y.sub. TK_IN, _SELECT, or _EXISTS */

  17503. #define EP_Quoted   0x4000000 /* TK_ID was originally quoted */

  17504. #define EP_Static   0x8000000 /* Held in memory not obtained from malloc() */

  17505. #define EP_IsTrue  0x10000000 /* Always has boolean value of TRUE */

  17506. #define EP_IsFalse 0x20000000 /* Always has boolean value of FALSE */

  17507. 

  17508. /*

  17509. ** The EP_Propagate mask is a set of properties that automatically propagate

  17510. ** upwards into parent nodes.

  17511. */

  17512. #define EP_Propagate (EP_Collate|EP_Subquery|EP_HasFunc)

  17513. 

  17514. /*

  17515. ** These macros can be used to test, set, or clear bits in the

  17516. ** Expr.flags field.

  17517. */

  17518. #define ExprHasProperty(E,P)     (((E)->flags&(P))!=0)

  17519. #define ExprHasAllProperty(E,P)  (((E)->flags&(P))==(P))

  17520. #define ExprSetProperty(E,P)     (E)->flags|=(P)

  17521. #define ExprClearProperty(E,P)   (E)->flags&=~(P)

  17522. #define ExprAlwaysTrue(E)   (((E)->flags&(EP_FromJoin|EP_IsTrue))==EP_IsTrue)

  17523. #define ExprAlwaysFalse(E)  (((E)->flags&(EP_FromJoin|EP_IsFalse))==EP_IsFalse)

  17524. 

  17525. /* The ExprSetVVAProperty() macro is used for Verification, Validation,

  17526. ** and Accreditation only.  It works like ExprSetProperty() during VVA

  17527. ** processes but is a no-op for delivery.

  17528. */

  17529. #ifdef SQLITE_DEBUG

  17530. # define ExprSetVVAProperty(E,P)  (E)->flags|=(P)

  17531. #else

  17532. # define ExprSetVVAProperty(E,P)

  17533. #endif

  17534. 

  17535. /*

  17536. ** Macros to determine the number of bytes required by a normal Expr

  17537. ** struct, an Expr struct with the EP_Reduced flag set in Expr.flags

  17538. ** and an Expr struct with the EP_TokenOnly flag set.

  17539. */

  17540. #define EXPR_FULLSIZE           sizeof(Expr)           /* Full size */

  17541. #define EXPR_REDUCEDSIZE        offsetof(Expr,iTable)  /* Common features */

  17542. #define EXPR_TOKENONLYSIZE      offsetof(Expr,pLeft)   /* Fewer features */

  17543. 

  17544. /*

  17545. ** Flags passed to the sqlite3ExprDup() function. See the header comment

  17546. ** above sqlite3ExprDup() for details.

  17547. */

  17548. #define EXPRDUP_REDUCE         0x0001  /* Used reduced-size Expr nodes */

  17549. 

  17550. /*

  17551. ** A list of expressions.  Each expression may optionally have a

  17552. ** name.  An expr/name combination can be used in several ways, such

  17553. ** as the list of "expr AS ID" fields following a "SELECT" or in the

  17554. ** list of "ID = expr" items in an UPDATE.  A list of expressions can

  17555. ** also be used as the argument to a function, in which case the a.zName

  17556. ** field is not used.

  17557. **

  17558. ** By default the Expr.zSpan field holds a human-readable description of

  17559. ** the expression that is used in the generation of error messages and

  17560. ** column labels.  In this case, Expr.zSpan is typically the text of a

  17561. ** column expression as it exists in a SELECT statement.  However, if

  17562. ** the bSpanIsTab flag is set, then zSpan is overloaded to mean the name

  17563. ** of the result column in the form: DATABASE.TABLE.COLUMN.  This later

  17564. ** form is used for name resolution with nested FROM clauses.

  17565. */

  17566. struct ExprList {

  17567.   int nExpr;             /* Number of expressions on the list */

  17568.   struct ExprList_item { /* For each expression in the list */

  17569.     Expr *pExpr;            /* The parse tree for this expression */

  17570.     char *zName;            /* Token associated with this expression */

  17571.     char *zSpan;            /* Original text of the expression */

  17572.     u8 sortOrder;           /* 1 for DESC or 0 for ASC */

  17573.     unsigned done :1;       /* A flag to indicate when processing is finished */

  17574.     unsigned bSpanIsTab :1; /* zSpan holds DB.TABLE.COLUMN */

  17575.     unsigned reusable :1;   /* Constant expression is reusable */

  17576.     unsigned bSorterRef :1; /* Defer evaluation until after sorting */

  17577.     union {

  17578.       struct {

  17579.         u16 iOrderByCol;      /* For ORDER BY, column number in result set */

  17580.         u16 iAlias;           /* Index into Parse.aAlias[] for zName */

  17581.       } x;

  17582.       int iConstExprReg;      /* Register in which Expr value is cached */

  17583.     } u;

  17584.   } a[1];                  /* One slot for each expression in the list */

  17585. };

  17586. 

  17587. /*

  17588. ** An instance of this structure can hold a simple list of identifiers,

  17589. ** such as the list "a,b,c" in the following statements:

  17590. **

  17591. **      INSERT INTO t(a,b,c) VALUES ...;

  17592. **      CREATE INDEX idx ON t(a,b,c);

  17593. **      CREATE TRIGGER trig BEFORE UPDATE ON t(a,b,c) ...;

  17594. **

  17595. ** The IdList.a.idx field is used when the IdList represents the list of

  17596. ** column names after a table name in an INSERT statement.  In the statement

  17597. **

  17598. **     INSERT INTO t(a,b,c) ...

  17599. **

  17600. ** If "a" is the k-th column of table "t", then IdList.a[0].idx==k.

  17601. */

  17602. struct IdList {

  17603.   struct IdList_item {

  17604.     char *zName;      /* Name of the identifier */

  17605.     int idx;          /* Index in some Table.aCol[] of a column named zName */

  17606.   } *a;

  17607.   int nId;         /* Number of identifiers on the list */

  17608. };

  17609. 

  17610. /*

  17611. ** The following structure describes the FROM clause of a SELECT statement.

  17612. ** Each table or subquery in the FROM clause is a separate element of

  17613. ** the SrcList.a[] array.

  17614. **

  17615. ** With the addition of multiple database support, the following structure

  17616. ** can also be used to describe a particular table such as the table that

  17617. ** is modified by an INSERT, DELETE, or UPDATE statement.  In standard SQL,

  17618. ** such a table must be a simple name: ID.  But in SQLite, the table can

  17619. ** now be identified by a database name, a dot, then the table name: ID.ID.

  17620. **

  17621. ** The jointype starts out showing the join type between the current table

  17622. ** and the next table on the list.  The parser builds the list this way.

  17623. ** But sqlite3SrcListShiftJoinType() later shifts the jointypes so that each

  17624. ** jointype expresses the join between the table and the previous table.

  17625. **

  17626. ** In the colUsed field, the high-order bit (bit 63) is set if the table

  17627. ** contains more than 63 columns and the 64-th or later column is used.

  17628. */

  17629. struct SrcList {

  17630.   int nSrc;        /* Number of tables or subqueries in the FROM clause */

  17631.   u32 nAlloc;      /* Number of entries allocated in a[] below */

  17632.   struct SrcList_item {

  17633.     Schema *pSchema;  /* Schema to which this item is fixed */

  17634.     char *zDatabase;  /* Name of database holding this table */

  17635.     char *zName;      /* Name of the table */

  17636.     char *zAlias;     /* The "B" part of a "A AS B" phrase.  zName is the "A" */

  17637.     Table *pTab;      /* An SQL table corresponding to zName */

  17638.     Select *pSelect;  /* A SELECT statement used in place of a table name */

  17639.     int addrFillSub;  /* Address of subroutine to manifest a subquery */

  17640.     int regReturn;    /* Register holding return address of addrFillSub */

  17641.     int regResult;    /* Registers holding results of a co-routine */

  17642.     struct {

  17643.       u8 jointype;      /* Type of join between this table and the previous */

  17644.       unsigned notIndexed :1;    /* True if there is a NOT INDEXED clause */

  17645.       unsigned isIndexedBy :1;   /* True if there is an INDEXED BY clause */

  17646.       unsigned isTabFunc :1;     /* True if table-valued-function syntax */

  17647.       unsigned isCorrelated :1;  /* True if sub-query is correlated */

  17648.       unsigned viaCoroutine :1;  /* Implemented as a co-routine */

  17649.       unsigned isRecursive :1;   /* True for recursive reference in WITH */

  17650.     } fg;

  17651.     int iCursor;      /* The VDBE cursor number used to access this table */

  17652.     Expr *pOn;        /* The ON clause of a join */

  17653.     IdList *pUsing;   /* The USING clause of a join */

  17654.     Bitmask colUsed;  /* Bit N (1<<N) set if column N of pTab is used */

  17655.     union {

  17656.       char *zIndexedBy;    /* Identifier from "INDEXED BY <zIndex>" clause */

  17657.       ExprList *pFuncArg;  /* Arguments to table-valued-function */

  17658.     } u1;

  17659.     Index *pIBIndex;  /* Index structure corresponding to u1.zIndexedBy */

  17660.   } a[1];             /* One entry for each identifier on the list */

  17661. };

  17662. 

  17663. /*

  17664. ** Permitted values of the SrcList.a.jointype field

  17665. */

  17666. #define JT_INNER     0x0001    /* Any kind of inner or cross join */

  17667. #define JT_CROSS     0x0002    /* Explicit use of the CROSS keyword */

  17668. #define JT_NATURAL   0x0004    /* True for a "natural" join */

  17669. #define JT_LEFT      0x0008    /* Left outer join */

  17670. #define JT_RIGHT     0x0010    /* Right outer join */

  17671. #define JT_OUTER     0x0020    /* The "OUTER" keyword is present */

  17672. #define JT_ERROR     0x0040    /* unknown or unsupported join type */

  17673. 

  17674. 

  17675. /*

  17676. ** Flags appropriate for the wctrlFlags parameter of sqlite3WhereBegin()

  17677. ** and the WhereInfo.wctrlFlags member.

  17678. **

  17679. ** Value constraints (enforced via assert()):

  17680. **     WHERE_USE_LIMIT  == SF_FixedLimit

  17681. */

  17682. #define WHERE_ORDERBY_NORMAL   0x0000 /* No-op */

  17683. #define WHERE_ORDERBY_MIN      0x0001 /* ORDER BY processing for min() func */

  17684. #define WHERE_ORDERBY_MAX      0x0002 /* ORDER BY processing for max() func */

  17685. #define WHERE_ONEPASS_DESIRED  0x0004 /* Want to do one-pass UPDATE/DELETE */

  17686. #define WHERE_ONEPASS_MULTIROW 0x0008 /* ONEPASS is ok with multiple rows */

  17687. #define WHERE_DUPLICATES_OK    0x0010 /* Ok to return a row more than once */

  17688. #define WHERE_OR_SUBCLAUSE     0x0020 /* Processing a sub-WHERE as part of

  17689.                                       ** the OR optimization  */

  17690. #define WHERE_GROUPBY          0x0040 /* pOrderBy is really a GROUP BY */

  17691. #define WHERE_DISTINCTBY       0x0080 /* pOrderby is really a DISTINCT clause */

  17692. #define WHERE_WANT_DISTINCT    0x0100 /* All output needs to be distinct */

  17693. #define WHERE_SORTBYGROUP      0x0200 /* Support sqlite3WhereIsSorted() */

  17694. #define WHERE_SEEK_TABLE       0x0400 /* Do not defer seeks on main table */

  17695. #define WHERE_ORDERBY_LIMIT    0x0800 /* ORDERBY+LIMIT on the inner loop */

  17696. #define WHERE_SEEK_UNIQ_TABLE  0x1000 /* Do not defer seeks if unique */

  17697.                         /*     0x2000    not currently used */

  17698. #define WHERE_USE_LIMIT        0x4000 /* Use the LIMIT in cost estimates */

  17699.                         /*     0x8000    not currently used */

  17700. 

  17701. /* Allowed return values from sqlite3WhereIsDistinct()

  17702. */

  17703. #define WHERE_DISTINCT_NOOP      0  /* DISTINCT keyword not used */

  17704. #define WHERE_DISTINCT_UNIQUE    1  /* No duplicates */

  17705. #define WHERE_DISTINCT_ORDERED   2  /* All duplicates are adjacent */

  17706. #define WHERE_DISTINCT_UNORDERED 3  /* Duplicates are scattered */

  17707. 

  17708. /*

  17709. ** A NameContext defines a context in which to resolve table and column

  17710. ** names.  The context consists of a list of tables (the pSrcList) field and

  17711. ** a list of named expression (pEList).  The named expression list may

  17712. ** be NULL.  The pSrc corresponds to the FROM clause of a SELECT or

  17713. ** to the table being operated on by INSERT, UPDATE, or DELETE.  The

  17714. ** pEList corresponds to the result set of a SELECT and is NULL for

  17715. ** other statements.

  17716. **

  17717. ** NameContexts can be nested.  When resolving names, the inner-most

  17718. ** context is searched first.  If no match is found, the next outer

  17719. ** context is checked.  If there is still no match, the next context

  17720. ** is checked.  This process continues until either a match is found

  17721. ** or all contexts are check.  When a match is found, the nRef member of

  17722. ** the context containing the match is incremented.

  17723. **

  17724. ** Each subquery gets a new NameContext.  The pNext field points to the

  17725. ** NameContext in the parent query.  Thus the process of scanning the

  17726. ** NameContext list corresponds to searching through successively outer

  17727. ** subqueries looking for a match.

  17728. */

  17729. struct NameContext {

  17730.   Parse *pParse;       /* The parser */

  17731.   SrcList *pSrcList;   /* One or more tables used to resolve names */

  17732.   union {

  17733.     ExprList *pEList;    /* Optional list of result-set columns */

  17734.     AggInfo *pAggInfo;   /* Information about aggregates at this level */

  17735.     Upsert *pUpsert;     /* ON CONFLICT clause information from an upsert */

  17736.   } uNC;

  17737.   NameContext *pNext;  /* Next outer name context.  NULL for outermost */

  17738.   int nRef;            /* Number of names resolved by this context */

  17739.   int nErr;            /* Number of errors encountered while resolving names */

  17740.   int ncFlags;         /* Zero or more NC_* flags defined below */

  17741.   Select *pWinSelect;  /* SELECT statement for any window functions */

  17742. };

  17743. 

  17744. /*

  17745. ** Allowed values for the NameContext, ncFlags field.

  17746. **

  17747. ** Value constraints (all checked via assert()):

  17748. **    NC_HasAgg    == SF_HasAgg    == EP_Agg

  17749. **    NC_MinMaxAgg == SF_MinMaxAgg == SQLITE_FUNC_MINMAX

  17750. **    NC_HasWin    == EP_Win

  17751. **

  17752. */

  17753. #define NC_AllowAgg  0x0001  /* Aggregate functions are allowed here */

  17754. #define NC_PartIdx   0x0002  /* True if resolving a partial index WHERE */

  17755. #define NC_IsCheck   0x0004  /* True if resolving names in a CHECK constraint */

  17756. #define NC_InAggFunc 0x0008  /* True if analyzing arguments to an agg func */

  17757. #define NC_HasAgg    0x0010  /* One or more aggregate functions seen */

  17758. #define NC_IdxExpr   0x0020  /* True if resolving columns of CREATE INDEX */

  17759. #define NC_VarSelect 0x0040  /* A correlated subquery has been seen */

  17760. #define NC_UEList    0x0080  /* True if uNC.pEList is used */

  17761. #define NC_UAggInfo  0x0100  /* True if uNC.pAggInfo is used */

  17762. #define NC_UUpsert   0x0200  /* True if uNC.pUpsert is used */

  17763. #define NC_MinMaxAgg 0x1000  /* min/max aggregates seen.  See note above */

  17764. #define NC_Complex   0x2000  /* True if a function or subquery seen */

  17765. #define NC_AllowWin  0x4000  /* Window functions are allowed here */

  17766. #define NC_HasWin    0x8000  /* One or more window functions seen */

  17767. #define NC_IsDDL    0x10000  /* Resolving names in a CREATE statement */

  17768. 

  17769. /*

  17770. ** An instance of the following object describes a single ON CONFLICT

  17771. ** clause in an upsert.

  17772. **

  17773. ** The pUpsertTarget field is only set if the ON CONFLICT clause includes

  17774. ** conflict-target clause.  (In "ON CONFLICT(a,b)" the "(a,b)" is the

  17775. ** conflict-target clause.)  The pUpsertTargetWhere is the optional

  17776. ** WHERE clause used to identify partial unique indexes.

  17777. **

  17778. ** pUpsertSet is the list of column=expr terms of the UPDATE statement. 

  17779. ** The pUpsertSet field is NULL for a ON CONFLICT DO NOTHING.  The

  17780. ** pUpsertWhere is the WHERE clause for the UPDATE and is NULL if the

  17781. ** WHERE clause is omitted.

  17782. */

  17783. struct Upsert {

  17784.   ExprList *pUpsertTarget;  /* Optional description of conflicting index */

  17785.   Expr *pUpsertTargetWhere; /* WHERE clause for partial index targets */

  17786.   ExprList *pUpsertSet;     /* The SET clause from an ON CONFLICT UPDATE */

  17787.   Expr *pUpsertWhere;       /* WHERE clause for the ON CONFLICT UPDATE */

  17788.   /* The fields above comprise the parse tree for the upsert clause.

  17789.   ** The fields below are used to transfer information from the INSERT

  17790.   ** processing down into the UPDATE processing while generating code.

  17791.   ** Upsert owns the memory allocated above, but not the memory below. */

  17792.   Index *pUpsertIdx;        /* Constraint that pUpsertTarget identifies */

  17793.   SrcList *pUpsertSrc;      /* Table to be updated */

  17794.   int regData;              /* First register holding array of VALUES */

  17795.   int iDataCur;             /* Index of the data cursor */

  17796.   int iIdxCur;              /* Index of the first index cursor */

  17797. };

  17798. 

  17799. /*

  17800. ** An instance of the following structure contains all information

  17801. ** needed to generate code for a single SELECT statement.

  17802. **

  17803. ** See the header comment on the computeLimitRegisters() routine for a

  17804. ** detailed description of the meaning of the iLimit and iOffset fields.

  17805. **

  17806. ** addrOpenEphm[] entries contain the address of OP_OpenEphemeral opcodes.

  17807. ** These addresses must be stored so that we can go back and fill in

  17808. ** the P4_KEYINFO and P2 parameters later.  Neither the KeyInfo nor

  17809. ** the number of columns in P2 can be computed at the same time

  17810. ** as the OP_OpenEphm instruction is coded because not

  17811. ** enough information about the compound query is known at that point.

  17812. ** The KeyInfo for addrOpenTran[0] and [1] contains collating sequences

  17813. ** for the result set.  The KeyInfo for addrOpenEphm[2] contains collating

  17814. ** sequences for the ORDER BY clause.

  17815. */

  17816. struct Select {

  17817.   ExprList *pEList;      /* The fields of the result */

  17818.   u8 op;                 /* One of: TK_UNION TK_ALL TK_INTERSECT TK_EXCEPT */

  17819.   LogEst nSelectRow;     /* Estimated number of result rows */

  17820.   u32 selFlags;          /* Various SF_* values */

  17821.   int iLimit, iOffset;   /* Memory registers holding LIMIT & OFFSET counters */

  17822.   u32 selId;             /* Unique identifier number for this SELECT */

  17823.   int addrOpenEphm[2];   /* OP_OpenEphem opcodes related to this select */

  17824.   SrcList *pSrc;         /* The FROM clause */

  17825.   Expr *pWhere;          /* The WHERE clause */

  17826.   ExprList *pGroupBy;    /* The GROUP BY clause */

  17827.   Expr *pHaving;         /* The HAVING clause */

  17828.   ExprList *pOrderBy;    /* The ORDER BY clause */

  17829.   Select *pPrior;        /* Prior select in a compound select statement */

  17830.   Select *pNext;         /* Next select to the left in a compound */

  17831.   Expr *pLimit;          /* LIMIT expression. NULL means not used. */

  17832.   With *pWith;           /* WITH clause attached to this select. Or NULL. */

  17833. #ifndef SQLITE_OMIT_WINDOWFUNC

  17834.   Window *pWin;          /* List of window functions */

  17835.   Window *pWinDefn;      /* List of named window definitions */

  17836. #endif

  17837. };

  17838. 

  17839. /*

  17840. ** Allowed values for Select.selFlags.  The "SF" prefix stands for

  17841. ** "Select Flag".

  17842. **

  17843. ** Value constraints (all checked via assert())

  17844. **     SF_HasAgg     == NC_HasAgg

  17845. **     SF_MinMaxAgg  == NC_MinMaxAgg     == SQLITE_FUNC_MINMAX

  17846. **     SF_FixedLimit == WHERE_USE_LIMIT

  17847. */

  17848. #define SF_Distinct       0x00001  /* Output should be DISTINCT */

  17849. #define SF_All            0x00002  /* Includes the ALL keyword */

  17850. #define SF_Resolved       0x00004  /* Identifiers have been resolved */

  17851. #define SF_Aggregate      0x00008  /* Contains agg functions or a GROUP BY */

  17852. #define SF_HasAgg         0x00010  /* Contains aggregate functions */

  17853. #define SF_UsesEphemeral  0x00020  /* Uses the OpenEphemeral opcode */

  17854. #define SF_Expanded       0x00040  /* sqlite3SelectExpand() called on this */

  17855. #define SF_HasTypeInfo    0x00080  /* FROM subqueries have Table metadata */

  17856. #define SF_Compound       0x00100  /* Part of a compound query */

  17857. #define SF_Values         0x00200  /* Synthesized from VALUES clause */

  17858. #define SF_MultiValue     0x00400  /* Single VALUES term with multiple rows */

  17859. #define SF_NestedFrom     0x00800  /* Part of a parenthesized FROM clause */

  17860. #define SF_MinMaxAgg      0x01000  /* Aggregate containing min() or max() */

  17861. #define SF_Recursive      0x02000  /* The recursive part of a recursive CTE */

  17862. #define SF_FixedLimit     0x04000  /* nSelectRow set by a constant LIMIT */

  17863. #define SF_MaybeConvert   0x08000  /* Need convertCompoundSelectToSubquery() */

  17864. #define SF_Converted      0x10000  /* By convertCompoundSelectToSubquery() */

  17865. #define SF_IncludeHidden  0x20000  /* Include hidden columns in output */

  17866. #define SF_ComplexResult  0x40000  /* Result contains subquery or function */

  17867. 

  17868. /*

  17869. ** The results of a SELECT can be distributed in several ways, as defined

  17870. ** by one of the following macros.  The "SRT" prefix means "SELECT Result

  17871. ** Type".

  17872. **

  17873. **     SRT_Union       Store results as a key in a temporary index

  17874. **                     identified by pDest->iSDParm.

  17875. **

  17876. **     SRT_Except      Remove results from the temporary index pDest->iSDParm.

  17877. **

  17878. **     SRT_Exists      Store a 1 in memory cell pDest->iSDParm if the result

  17879. **                     set is not empty.

  17880. **

  17881. **     SRT_Discard     Throw the results away.  This is used by SELECT

  17882. **                     statements within triggers whose only purpose is

  17883. **                     the side-effects of functions.

  17884. **

  17885. ** All of the above are free to ignore their ORDER BY clause. Those that

  17886. ** follow must honor the ORDER BY clause.

  17887. **

  17888. **     SRT_Output      Generate a row of output (using the OP_ResultRow

  17889. **                     opcode) for each row in the result set.

  17890. **

  17891. **     SRT_Mem         Only valid if the result is a single column.

  17892. **                     Store the first column of the first result row

  17893. **                     in register pDest->iSDParm then abandon the rest

  17894. **                     of the query.  This destination implies "LIMIT 1".

  17895. **

  17896. **     SRT_Set         The result must be a single column.  Store each

  17897. **                     row of result as the key in table pDest->iSDParm.

  17898. **                     Apply the affinity pDest->affSdst before storing

  17899. **                     results.  Used to implement "IN (SELECT ...)".

  17900. **

  17901. **     SRT_EphemTab    Create an temporary table pDest->iSDParm and store

  17902. **                     the result there. The cursor is left open after

  17903. **                     returning.  This is like SRT_Table except that

  17904. **                     this destination uses OP_OpenEphemeral to create

  17905. **                     the table first.

  17906. **

  17907. **     SRT_Coroutine   Generate a co-routine that returns a new row of

  17908. **                     results each time it is invoked.  The entry point

  17909. **                     of the co-routine is stored in register pDest->iSDParm

  17910. **                     and the result row is stored in pDest->nDest registers

  17911. **                     starting with pDest->iSdst.

  17912. **

  17913. **     SRT_Table       Store results in temporary table pDest->iSDParm.

  17914. **     SRT_Fifo        This is like SRT_EphemTab except that the table

  17915. **                     is assumed to already be open.  SRT_Fifo has

  17916. **                     the additional property of being able to ignore

  17917. **                     the ORDER BY clause.

  17918. **

  17919. **     SRT_DistFifo    Store results in a temporary table pDest->iSDParm.

  17920. **                     But also use temporary table pDest->iSDParm+1 as

  17921. **                     a record of all prior results and ignore any duplicate

  17922. **                     rows.  Name means:  "Distinct Fifo".

  17923. **

  17924. **     SRT_Queue       Store results in priority queue pDest->iSDParm (really

  17925. **                     an index).  Append a sequence number so that all entries

  17926. **                     are distinct.

  17927. **

  17928. **     SRT_DistQueue   Store results in priority queue pDest->iSDParm only if

  17929. **                     the same record has never been stored before.  The

  17930. **                     index at pDest->iSDParm+1 hold all prior stores.

  17931. */

  17932. #define SRT_Union        1  /* Store result as keys in an index */

  17933. #define SRT_Except       2  /* Remove result from a UNION index */

  17934. #define SRT_Exists       3  /* Store 1 if the result is not empty */

  17935. #define SRT_Discard      4  /* Do not save the results anywhere */

  17936. #define SRT_Fifo         5  /* Store result as data with an automatic rowid */

  17937. #define SRT_DistFifo     6  /* Like SRT_Fifo, but unique results only */

  17938. #define SRT_Queue        7  /* Store result in an queue */

  17939. #define SRT_DistQueue    8  /* Like SRT_Queue, but unique results only */

  17940. 

  17941. /* The ORDER BY clause is ignored for all of the above */

  17942. #define IgnorableOrderby(X) ((X->eDest)<=SRT_DistQueue)

  17943. 

  17944. #define SRT_Output       9  /* Output each row of result */

  17945. #define SRT_Mem         10  /* Store result in a memory cell */

  17946. #define SRT_Set         11  /* Store results as keys in an index */

  17947. #define SRT_EphemTab    12  /* Create transient tab and store like SRT_Table */

  17948. #define SRT_Coroutine   13  /* Generate a single row of result */

  17949. #define SRT_Table       14  /* Store result as data with an automatic rowid */

  17950. 

  17951. /*

  17952. ** An instance of this object describes where to put of the results of

  17953. ** a SELECT statement.

  17954. */

  17955. struct SelectDest {

  17956.   u8 eDest;            /* How to dispose of the results.  On of SRT_* above. */

  17957.   int iSDParm;         /* A parameter used by the eDest disposal method */

  17958.   int iSdst;           /* Base register where results are written */

  17959.   int nSdst;           /* Number of registers allocated */

  17960.   char *zAffSdst;      /* Affinity used when eDest==SRT_Set */

  17961.   ExprList *pOrderBy;  /* Key columns for SRT_Queue and SRT_DistQueue */

  17962. };

  17963. 

  17964. /*

  17965. ** During code generation of statements that do inserts into AUTOINCREMENT

  17966. ** tables, the following information is attached to the Table.u.autoInc.p

  17967. ** pointer of each autoincrement table to record some side information that

  17968. ** the code generator needs.  We have to keep per-table autoincrement

  17969. ** information in case inserts are done within triggers.  Triggers do not

  17970. ** normally coordinate their activities, but we do need to coordinate the

  17971. ** loading and saving of autoincrement information.

  17972. */

  17973. struct AutoincInfo {

  17974.   AutoincInfo *pNext;   /* Next info block in a list of them all */

  17975.   Table *pTab;          /* Table this info block refers to */

  17976.   int iDb;              /* Index in sqlite3.aDb[] of database holding pTab */

  17977.   int regCtr;           /* Memory register holding the rowid counter */

  17978. };

  17979. 

  17980. /*

  17981. ** At least one instance of the following structure is created for each

  17982. ** trigger that may be fired while parsing an INSERT, UPDATE or DELETE

  17983. ** statement. All such objects are stored in the linked list headed at

  17984. ** Parse.pTriggerPrg and deleted once statement compilation has been

  17985. ** completed.

  17986. **

  17987. ** A Vdbe sub-program that implements the body and WHEN clause of trigger

  17988. ** TriggerPrg.pTrigger, assuming a default ON CONFLICT clause of

  17989. ** TriggerPrg.orconf, is stored in the TriggerPrg.pProgram variable.

  17990. ** The Parse.pTriggerPrg list never contains two entries with the same

  17991. ** values for both pTrigger and orconf.

  17992. **

  17993. ** The TriggerPrg.aColmask[0] variable is set to a mask of old.* columns

  17994. ** accessed (or set to 0 for triggers fired as a result of INSERT

  17995. ** statements). Similarly, the TriggerPrg.aColmask[1] variable is set to

  17996. ** a mask of new.* columns used by the program.

  17997. */

  17998. struct TriggerPrg {

  17999.   Trigger *pTrigger;      /* Trigger this program was coded from */

  18000.   TriggerPrg *pNext;      /* Next entry in Parse.pTriggerPrg list */

  18001.   SubProgram *pProgram;   /* Program implementing pTrigger/orconf */

  18002.   int orconf;             /* Default ON CONFLICT policy */

  18003.   u32 aColmask[2];        /* Masks of old.*, new.* columns accessed */

  18004. };

  18005. 

  18006. /*

  18007. ** The yDbMask datatype for the bitmask of all attached databases.

  18008. */

  18009. #if SQLITE_MAX_ATTACHED>30

  18010.   typedef unsigned char yDbMask[(SQLITE_MAX_ATTACHED+9)/8];

  18011. # define DbMaskTest(M,I)    (((M)[(I)/8]&(1<<((I)&7)))!=0)

  18012. # define DbMaskZero(M)      memset((M),0,sizeof(M))

  18013. # define DbMaskSet(M,I)     (M)[(I)/8]|=(1<<((I)&7))

  18014. # define DbMaskAllZero(M)   sqlite3DbMaskAllZero(M)

  18015. # define DbMaskNonZero(M)   (sqlite3DbMaskAllZero(M)==0)

  18016. #else

  18017.   typedef unsigned int yDbMask;

  18018. # define DbMaskTest(M,I)    (((M)&(((yDbMask)1)<<(I)))!=0)

  18019. # define DbMaskZero(M)      (M)=0

  18020. # define DbMaskSet(M,I)     (M)|=(((yDbMask)1)<<(I))

  18021. # define DbMaskAllZero(M)   (M)==0

  18022. # define DbMaskNonZero(M)   (M)!=0

  18023. #endif

  18024. 

  18025. /*

  18026. ** An SQL parser context.  A copy of this structure is passed through

  18027. ** the parser and down into all the parser action routine in order to

  18028. ** carry around information that is global to the entire parse.

  18029. **

  18030. ** The structure is divided into two parts.  When the parser and code

  18031. ** generate call themselves recursively, the first part of the structure

  18032. ** is constant but the second part is reset at the beginning and end of

  18033. ** each recursion.

  18034. **

  18035. ** The nTableLock and aTableLock variables are only used if the shared-cache

  18036. ** feature is enabled (if sqlite3Tsd()->useSharedData is true). They are

  18037. ** used to store the set of table-locks required by the statement being

  18038. ** compiled. Function sqlite3TableLock() is used to add entries to the

  18039. ** list.

  18040. */

  18041. struct Parse {

  18042.   sqlite3 *db;         /* The main database structure */

  18043.   char *zErrMsg;       /* An error message */

  18044.   Vdbe *pVdbe;         /* An engine for executing database bytecode */

  18045.   int rc;              /* Return code from execution */

  18046.   u8 colNamesSet;      /* TRUE after OP_ColumnName has been issued to pVdbe */

  18047.   u8 checkSchema;      /* Causes schema cookie check after an error */

  18048.   u8 nested;           /* Number of nested calls to the parser/code generator */

  18049.   u8 nTempReg;         /* Number of temporary registers in aTempReg[] */

  18050.   u8 isMultiWrite;     /* True if statement may modify/insert multiple rows */

  18051.   u8 mayAbort;         /* True if statement may throw an ABORT exception */

  18052.   u8 hasCompound;      /* Need to invoke convertCompoundSelectToSubquery() */

  18053.   u8 okConstFactor;    /* OK to factor out constants */

  18054.   u8 disableLookaside; /* Number of times lookaside has been disabled */

  18055.   u8 disableVtab;      /* Disable all virtual tables for this parse */

  18056.   int nRangeReg;       /* Size of the temporary register block */

  18057.   int iRangeReg;       /* First register in temporary register block */

  18058.   int nErr;            /* Number of errors seen */

  18059.   int nTab;            /* Number of previously allocated VDBE cursors */

  18060.   int nMem;            /* Number of memory cells used so far */

  18061.   int szOpAlloc;       /* Bytes of memory space allocated for Vdbe.aOp[] */

  18062.   int iSelfTab;        /* Table associated with an index on expr, or negative

  18063.                        ** of the base register during check-constraint eval */

  18064.   int nLabel;          /* The *negative* of the number of labels used */

  18065.   int nLabelAlloc;     /* Number of slots in aLabel */

  18066.   int *aLabel;         /* Space to hold the labels */

  18067.   ExprList *pConstExpr;/* Constant expressions */

  18068.   Token constraintName;/* Name of the constraint currently being parsed */

  18069.   yDbMask writeMask;   /* Start a write transaction on these databases */

  18070.   yDbMask cookieMask;  /* Bitmask of schema verified databases */

  18071.   int regRowid;        /* Register holding rowid of CREATE TABLE entry */

  18072.   int regRoot;         /* Register holding root page number for new objects */

  18073.   int nMaxArg;         /* Max args passed to user function by sub-program */

  18074.   int nSelect;         /* Number of SELECT stmts. Counter for Select.selId */

  18075. #ifndef SQLITE_OMIT_SHARED_CACHE

  18076.   int nTableLock;        /* Number of locks in aTableLock */

  18077.   TableLock *aTableLock; /* Required table locks for shared-cache mode */

  18078. #endif

  18079.   AutoincInfo *pAinc;  /* Information about AUTOINCREMENT counters */

  18080.   Parse *pToplevel;    /* Parse structure for main program (or NULL) */

  18081.   Table *pTriggerTab;  /* Table triggers are being coded for */

  18082.   Parse *pParentParse; /* Parent parser if this parser is nested */

  18083.   int addrCrTab;       /* Address of OP_CreateBtree opcode on CREATE TABLE */

  18084.   u32 nQueryLoop;      /* Est number of iterations of a query (10*log2(N)) */

  18085.   u32 oldmask;         /* Mask of old.* columns referenced */

  18086.   u32 newmask;         /* Mask of new.* columns referenced */

  18087.   u8 eTriggerOp;       /* TK_UPDATE, TK_INSERT or TK_DELETE */

  18088.   u8 eOrconf;          /* Default ON CONFLICT policy for trigger steps */

  18089.   u8 disableTriggers;  /* True to disable triggers */

  18090. 

  18091.   /**************************************************************************

  18092.   ** Fields above must be initialized to zero.  The fields that follow,

  18093.   ** down to the beginning of the recursive section, do not need to be

  18094.   ** initialized as they will be set before being used.  The boundary is

  18095.   ** determined by offsetof(Parse,aTempReg).

  18096.   **************************************************************************/

  18097. 

  18098.   int aTempReg[8];        /* Holding area for temporary registers */

  18099.   Token sNameToken;       /* Token with unqualified schema object name */

  18100. 

  18101.   /************************************************************************

  18102.   ** Above is constant between recursions.  Below is reset before and after

  18103.   ** each recursion.  The boundary between these two regions is determined

  18104.   ** using offsetof(Parse,sLastToken) so the sLastToken field must be the

  18105.   ** first field in the recursive region.

  18106.   ************************************************************************/

  18107. 

  18108.   Token sLastToken;       /* The last token parsed */

  18109.   ynVar nVar;               /* Number of '?' variables seen in the SQL so far */

  18110.   u8 iPkSortOrder;          /* ASC or DESC for INTEGER PRIMARY KEY */

  18111.   u8 explain;               /* True if the EXPLAIN flag is found on the query */

  18112. #if !(defined(SQLITE_OMIT_VIRTUALTABLE) && defined(SQLITE_OMIT_ALTERTABLE))

  18113.   u8 eParseMode;            /* PARSE_MODE_XXX constant */

  18114. #endif

  18115. #ifndef SQLITE_OMIT_VIRTUALTABLE

  18116.   int nVtabLock;            /* Number of virtual tables to lock */

  18117. #endif

  18118.   int nHeight;              /* Expression tree height of current sub-select */

  18119. #ifndef SQLITE_OMIT_EXPLAIN

  18120.   int addrExplain;          /* Address of current OP_Explain opcode */

  18121. #endif

  18122.   VList *pVList;            /* Mapping between variable names and numbers */

  18123.   Vdbe *pReprepare;         /* VM being reprepared (sqlite3Reprepare()) */

  18124.   const char *zTail;        /* All SQL text past the last semicolon parsed */

  18125.   Table *pNewTable;         /* A table being constructed by CREATE TABLE */

  18126.   Index *pNewIndex;         /* An index being constructed by CREATE INDEX.

  18127.                             ** Also used to hold redundant UNIQUE constraints

  18128.                             ** during a RENAME COLUMN */

  18129.   Trigger *pNewTrigger;     /* Trigger under construct by a CREATE TRIGGER */

  18130.   const char *zAuthContext; /* The 6th parameter to db->xAuth callbacks */

  18131. #ifndef SQLITE_OMIT_VIRTUALTABLE

  18132.   Token sArg;               /* Complete text of a module argument */

  18133.   Table **apVtabLock;       /* Pointer to virtual tables needing locking */

  18134. #endif

  18135.   Table *pZombieTab;        /* List of Table objects to delete after code gen */

  18136.   TriggerPrg *pTriggerPrg;  /* Linked list of coded triggers */

  18137.   With *pWith;              /* Current WITH clause, or NULL */

  18138.   With *pWithToFree;        /* Free this WITH object at the end of the parse */

  18139. #ifndef SQLITE_OMIT_ALTERTABLE

  18140.   RenameToken *pRename;     /* Tokens subject to renaming by ALTER TABLE */

  18141. #endif

  18142. };

  18143. 

  18144. #define PARSE_MODE_NORMAL        0

  18145. #define PARSE_MODE_DECLARE_VTAB  1

  18146. #define PARSE_MODE_RENAME_COLUMN 2

  18147. #define PARSE_MODE_RENAME_TABLE  3

  18148. 

  18149. /*

  18150. ** Sizes and pointers of various parts of the Parse object.

  18151. */

  18152. #define PARSE_HDR_SZ offsetof(Parse,aTempReg) /* Recursive part w/o aColCache*/

  18153. #define PARSE_RECURSE_SZ offsetof(Parse,sLastToken)    /* Recursive part */

  18154. #define PARSE_TAIL_SZ (sizeof(Parse)-PARSE_RECURSE_SZ) /* Non-recursive part */

  18155. #define PARSE_TAIL(X) (((char*)(X))+PARSE_RECURSE_SZ)  /* Pointer to tail */

  18156. 

  18157. /*

  18158. ** Return true if currently inside an sqlite3_declare_vtab() call.

  18159. */

  18160. #ifdef SQLITE_OMIT_VIRTUALTABLE

  18161.   #define IN_DECLARE_VTAB 0

  18162. #else

  18163.   #define IN_DECLARE_VTAB (pParse->eParseMode==PARSE_MODE_DECLARE_VTAB)

  18164. #endif

  18165. 

  18166. #if defined(SQLITE_OMIT_ALTERTABLE)

  18167.   #define IN_RENAME_OBJECT 0

  18168. #else

  18169.   #define IN_RENAME_OBJECT (pParse->eParseMode>=PARSE_MODE_RENAME_COLUMN)

  18170. #endif

  18171. 

  18172. #if defined(SQLITE_OMIT_VIRTUALTABLE) && defined(SQLITE_OMIT_ALTERTABLE)

  18173.   #define IN_SPECIAL_PARSE 0

  18174. #else

  18175.   #define IN_SPECIAL_PARSE (pParse->eParseMode!=PARSE_MODE_NORMAL)

  18176. #endif

  18177. 

  18178. /*

  18179. ** An instance of the following structure can be declared on a stack and used

  18180. ** to save the Parse.zAuthContext value so that it can be restored later.

  18181. */

  18182. struct AuthContext {

  18183.   const char *zAuthContext;   /* Put saved Parse.zAuthContext here */

  18184.   Parse *pParse;              /* The Parse structure */

  18185. };

  18186. 

  18187. /*

  18188. ** Bitfield flags for P5 value in various opcodes.

  18189. **

  18190. ** Value constraints (enforced via assert()):

  18191. **    OPFLAG_LENGTHARG    == SQLITE_FUNC_LENGTH

  18192. **    OPFLAG_TYPEOFARG    == SQLITE_FUNC_TYPEOF

  18193. **    OPFLAG_BULKCSR      == BTREE_BULKLOAD

  18194. **    OPFLAG_SEEKEQ       == BTREE_SEEK_EQ

  18195. **    OPFLAG_FORDELETE    == BTREE_FORDELETE

  18196. **    OPFLAG_SAVEPOSITION == BTREE_SAVEPOSITION

  18197. **    OPFLAG_AUXDELETE    == BTREE_AUXDELETE

  18198. */

  18199. #define OPFLAG_NCHANGE       0x01    /* OP_Insert: Set to update db->nChange */

  18200.                                      /* Also used in P2 (not P5) of OP_Delete */

  18201. #define OPFLAG_NOCHNG        0x01    /* OP_VColumn nochange for UPDATE */

  18202. #define OPFLAG_EPHEM         0x01    /* OP_Column: Ephemeral output is ok */

  18203. #define OPFLAG_LASTROWID     0x20    /* Set to update db->lastRowid */

  18204. #define OPFLAG_ISUPDATE      0x04    /* This OP_Insert is an sql UPDATE */

  18205. #define OPFLAG_APPEND        0x08    /* This is likely to be an append */

  18206. #define OPFLAG_USESEEKRESULT 0x10    /* Try to avoid a seek in BtreeInsert() */

  18207. #define OPFLAG_ISNOOP        0x40    /* OP_Delete does pre-update-hook only */

  18208. #define OPFLAG_LENGTHARG     0x40    /* OP_Column only used for length() */

  18209. #define OPFLAG_TYPEOFARG     0x80    /* OP_Column only used for typeof() */

  18210. #define OPFLAG_BULKCSR       0x01    /* OP_Open** used to open bulk cursor */

  18211. #define OPFLAG_SEEKEQ        0x02    /* OP_Open** cursor uses EQ seek only */

  18212. #define OPFLAG_FORDELETE     0x08    /* OP_Open should use BTREE_FORDELETE */

  18213. #define OPFLAG_P2ISREG       0x10    /* P2 to OP_Open** is a register number */

  18214. #define OPFLAG_PERMUTE       0x01    /* OP_Compare: use the permutation */

  18215. #define OPFLAG_SAVEPOSITION  0x02    /* OP_Delete/Insert: save cursor pos */

  18216. #define OPFLAG_AUXDELETE     0x04    /* OP_Delete: index in a DELETE op */

  18217. #define OPFLAG_NOCHNG_MAGIC  0x6d    /* OP_MakeRecord: serialtype 10 is ok */

  18218. 

  18219. /*

  18220.  * Each trigger present in the database schema is stored as an instance of

  18221.  * struct Trigger.

  18222.  *

  18223.  * Pointers to instances of struct Trigger are stored in two ways.

  18224.  * 1. In the "trigHash" hash table (part of the sqlite3* that represents the

  18225.  *    database). This allows Trigger structures to be retrieved by name.

  18226.  * 2. All triggers associated with a single table form a linked list, using the

  18227.  *    pNext member of struct Trigger. A pointer to the first element of the

  18228.  *    linked list is stored as the "pTrigger" member of the associated

  18229.  *    struct Table.

  18230.  *

  18231.  * The "step_list" member points to the first element of a linked list

  18232.  * containing the SQL statements specified as the trigger program.

  18233.  */

  18234. struct Trigger {

  18235.   char *zName;            /* The name of the trigger                        */

  18236.   char *table;            /* The table or view to which the trigger applies */

  18237.   u8 op;                  /* One of TK_DELETE, TK_UPDATE, TK_INSERT         */

  18238.   u8 tr_tm;               /* One of TRIGGER_BEFORE, TRIGGER_AFTER */

  18239.   Expr *pWhen;            /* The WHEN clause of the expression (may be NULL) */

  18240.   IdList *pColumns;       /* If this is an UPDATE OF <column-list> trigger,

  18241.                              the <column-list> is stored here */

  18242.   Schema *pSchema;        /* Schema containing the trigger */

  18243.   Schema *pTabSchema;     /* Schema containing the table */

  18244.   TriggerStep *step_list; /* Link list of trigger program steps             */

  18245.   Trigger *pNext;         /* Next trigger associated with the table */

  18246. };

  18247. 

  18248. /*

  18249. ** A trigger is either a BEFORE or an AFTER trigger.  The following constants

  18250. ** determine which.

  18251. **

  18252. ** If there are multiple triggers, you might of some BEFORE and some AFTER.

  18253. ** In that cases, the constants below can be ORed together.

  18254. */

  18255. #define TRIGGER_BEFORE  1

  18256. #define TRIGGER_AFTER   2

  18257. 

  18258. /*

  18259.  * An instance of struct TriggerStep is used to store a single SQL statement

  18260.  * that is a part of a trigger-program.

  18261.  *

  18262.  * Instances of struct TriggerStep are stored in a singly linked list (linked

  18263.  * using the "pNext" member) referenced by the "step_list" member of the

  18264.  * associated struct Trigger instance. The first element of the linked list is

  18265.  * the first step of the trigger-program.

  18266.  *

  18267.  * The "op" member indicates whether this is a "DELETE", "INSERT", "UPDATE" or

  18268.  * "SELECT" statement. The meanings of the other members is determined by the

  18269.  * value of "op" as follows:

  18270.  *

  18271.  * (op == TK_INSERT)

  18272.  * orconf    -> stores the ON CONFLICT algorithm

  18273.  * pSelect   -> If this is an INSERT INTO ... SELECT ... statement, then

  18274.  *              this stores a pointer to the SELECT statement. Otherwise NULL.

  18275.  * zTarget   -> Dequoted name of the table to insert into.

  18276.  * pExprList -> If this is an INSERT INTO ... VALUES ... statement, then

  18277.  *              this stores values to be inserted. Otherwise NULL.

  18278.  * pIdList   -> If this is an INSERT INTO ... (<column-names>) VALUES ...

  18279.  *              statement, then this stores the column-names to be

  18280.  *              inserted into.

  18281.  *

  18282.  * (op == TK_DELETE)

  18283.  * zTarget   -> Dequoted name of the table to delete from.

  18284.  * pWhere    -> The WHERE clause of the DELETE statement if one is specified.

  18285.  *              Otherwise NULL.

  18286.  *

  18287.  * (op == TK_UPDATE)

  18288.  * zTarget   -> Dequoted name of the table to update.

  18289.  * pWhere    -> The WHERE clause of the UPDATE statement if one is specified.

  18290.  *              Otherwise NULL.

  18291.  * pExprList -> A list of the columns to update and the expressions to update

  18292.  *              them to. See sqlite3Update() documentation of "pChanges"

  18293.  *              argument.

  18294.  *

  18295.  */

  18296. struct TriggerStep {

  18297.   u8 op;               /* One of TK_DELETE, TK_UPDATE, TK_INSERT, TK_SELECT */

  18298.   u8 orconf;           /* OE_Rollback etc. */

  18299.   Trigger *pTrig;      /* The trigger that this step is a part of */

  18300.   Select *pSelect;     /* SELECT statement or RHS of INSERT INTO SELECT ... */

  18301.   char *zTarget;       /* Target table for DELETE, UPDATE, INSERT */

  18302.   Expr *pWhere;        /* The WHERE clause for DELETE or UPDATE steps */

  18303.   ExprList *pExprList; /* SET clause for UPDATE */

  18304.   IdList *pIdList;     /* Column names for INSERT */

  18305.   Upsert *pUpsert;     /* Upsert clauses on an INSERT */

  18306.   char *zSpan;         /* Original SQL text of this command */

  18307.   TriggerStep *pNext;  /* Next in the link-list */

  18308.   TriggerStep *pLast;  /* Last element in link-list. Valid for 1st elem only */

  18309. };

  18310. 

  18311. /*

  18312. ** The following structure contains information used by the sqliteFix...

  18313. ** routines as they walk the parse tree to make database references

  18314. ** explicit.

  18315. */

  18316. typedef struct DbFixer DbFixer;

  18317. struct DbFixer {

  18318.   Parse *pParse;      /* The parsing context.  Error messages written here */

  18319.   Schema *pSchema;    /* Fix items to this schema */

  18320.   int bVarOnly;       /* Check for variable references only */

  18321.   const char *zDb;    /* Make sure all objects are contained in this database */

  18322.   const char *zType;  /* Type of the container - used for error messages */

  18323.   const Token *pName; /* Name of the container - used for error messages */

  18324. };

  18325. 

  18326. /*

  18327. ** An objected used to accumulate the text of a string where we

  18328. ** do not necessarily know how big the string will be in the end.

  18329. */

  18330. struct sqlite3_str {

  18331.   sqlite3 *db;         /* Optional database for lookaside.  Can be NULL */

  18332.   char *zText;         /* The string collected so far */

  18333.   u32  nAlloc;         /* Amount of space allocated in zText */

  18334.   u32  mxAlloc;        /* Maximum allowed allocation.  0 for no malloc usage */

  18335.   u32  nChar;          /* Length of the string so far */

  18336.   u8   accError;       /* SQLITE_NOMEM or SQLITE_TOOBIG */

  18337.   u8   printfFlags;    /* SQLITE_PRINTF flags below */

  18338. };

  18339. #define SQLITE_PRINTF_INTERNAL 0x01  /* Internal-use-only converters allowed */

  18340. #define SQLITE_PRINTF_SQLFUNC  0x02  /* SQL function arguments to VXPrintf */

  18341. #define SQLITE_PRINTF_MALLOCED 0x04  /* True if xText is allocated space */

  18342. 

  18343. #define isMalloced(X)  (((X)->printfFlags & SQLITE_PRINTF_MALLOCED)!=0)

  18344. 

  18345. 

  18346. /*

  18347. ** A pointer to this structure is used to communicate information

  18348. ** from sqlite3Init and OP_ParseSchema into the sqlite3InitCallback.

  18349. */

  18350. typedef struct {

  18351.   sqlite3 *db;        /* The database being initialized */

  18352.   char **pzErrMsg;    /* Error message stored here */

  18353.   int iDb;            /* 0 for main database.  1 for TEMP, 2.. for ATTACHed */

  18354.   int rc;             /* Result code stored here */

  18355.   u32 mInitFlags;     /* Flags controlling error messages */

  18356.   u32 nInitRow;       /* Number of rows processed */

  18357. } InitData;

  18358. 

  18359. /*

  18360. ** Allowed values for mInitFlags

  18361. */

  18362. #define INITFLAG_AlterTable   0x0001  /* This is a reparse after ALTER TABLE */

  18363. 

  18364. /*

  18365. ** Structure containing global configuration data for the SQLite library.

  18366. **

  18367. ** This structure also contains some state information.

  18368. */

  18369. struct Sqlite3Config {

  18370.   int bMemstat;                     /* True to enable memory status */

  18371.   int bCoreMutex;                   /* True to enable core mutexing */

  18372.   int bFullMutex;                   /* True to enable full mutexing */

  18373.   int bOpenUri;                     /* True to interpret filenames as URIs */

  18374.   int bUseCis;                      /* Use covering indices for full-scans */

  18375.   int bSmallMalloc;                 /* Avoid large memory allocations if true */

  18376.   int mxStrlen;                     /* Maximum string length */

  18377.   int neverCorrupt;                 /* Database is always well-formed */

  18378.   int szLookaside;                  /* Default lookaside buffer size */

  18379.   int nLookaside;                   /* Default lookaside buffer count */

  18380.   int nStmtSpill;                   /* Stmt-journal spill-to-disk threshold */

  18381.   sqlite3_mem_methods m;            /* Low-level memory allocation interface */

  18382.   sqlite3_mutex_methods mutex;      /* Low-level mutex interface */

  18383.   sqlite3_pcache_methods2 pcache2;  /* Low-level page-cache interface */

  18384.   void *pHeap;                      /* Heap storage space */

  18385.   int nHeap;                        /* Size of pHeap[] */

  18386.   int mnReq, mxReq;                 /* Min and max heap requests sizes */

  18387.   sqlite3_int64 szMmap;             /* mmap() space per open file */

  18388.   sqlite3_int64 mxMmap;             /* Maximum value for szMmap */

  18389.   void *pPage;                      /* Page cache memory */

  18390.   int szPage;                       /* Size of each page in pPage[] */

  18391.   int nPage;                        /* Number of pages in pPage[] */

  18392.   int mxParserStack;                /* maximum depth of the parser stack */

  18393.   int sharedCacheEnabled;           /* true if shared-cache mode enabled */

  18394.   u32 szPma;                        /* Maximum Sorter PMA size */

  18395.   /* The above might be initialized to non-zero.  The following need to always

  18396.   ** initially be zero, however. */

  18397.   int isInit;                       /* True after initialization has finished */

  18398.   int inProgress;                   /* True while initialization in progress */

  18399.   int isMutexInit;                  /* True after mutexes are initialized */

  18400.   int isMallocInit;                 /* True after malloc is initialized */

  18401.   int isPCacheInit;                 /* True after malloc is initialized */

  18402.   int nRefInitMutex;                /* Number of users of pInitMutex */

  18403.   sqlite3_mutex *pInitMutex;        /* Mutex used by sqlite3_initialize() */

  18404.   void (*xLog)(void*,int,const char*); /* Function for logging */

  18405.   void *pLogArg;                       /* First argument to xLog() */

  18406. #ifdef SQLITE_ENABLE_SQLLOG

  18407.   void(*xSqllog)(void*,sqlite3*,const char*, int);

  18408.   void *pSqllogArg;

  18409. #endif

  18410. #ifdef SQLITE_VDBE_COVERAGE

  18411.   /* The following callback (if not NULL) is invoked on every VDBE branch

  18412.   ** operation.  Set the callback using SQLITE_TESTCTRL_VDBE_COVERAGE.

  18413.   */

  18414.   void (*xVdbeBranch)(void*,unsigned iSrcLine,u8 eThis,u8 eMx);  /* Callback */

  18415.   void *pVdbeBranchArg;                                     /* 1st argument */

  18416. #endif

  18417. #ifdef SQLITE_ENABLE_DESERIALIZE

  18418.   sqlite3_int64 mxMemdbSize;        /* Default max memdb size */

  18419. #endif

  18420. #ifndef SQLITE_UNTESTABLE

  18421.   int (*xTestCallback)(int);        /* Invoked by sqlite3FaultSim() */

  18422. #endif

  18423.   int bLocaltimeFault;              /* True to fail localtime() calls */

  18424.   int bInternalFunctions;           /* Internal SQL functions are visible */

  18425.   int iOnceResetThreshold;          /* When to reset OP_Once counters */

  18426.   u32 szSorterRef;                  /* Min size in bytes to use sorter-refs */

  18427. };

  18428. 

  18429. /*

  18430. ** This macro is used inside of assert() statements to indicate that

  18431. ** the assert is only valid on a well-formed database.  Instead of:

  18432. **

  18433. **     assert( X );

  18434. **

  18435. ** One writes:

  18436. **

  18437. **     assert( X || CORRUPT_DB );

  18438. **

  18439. ** CORRUPT_DB is true during normal operation.  CORRUPT_DB does not indicate

  18440. ** that the database is definitely corrupt, only that it might be corrupt.

  18441. ** For most test cases, CORRUPT_DB is set to false using a special

  18442. ** sqlite3_test_control().  This enables assert() statements to prove

  18443. ** things that are always true for well-formed databases.

  18444. */

  18445. #define CORRUPT_DB  (sqlite3Config.neverCorrupt==0)

  18446. 

  18447. /*

  18448. ** Context pointer passed down through the tree-walk.

  18449. */

  18450. struct Walker {

  18451.   Parse *pParse;                            /* Parser context.  */

  18452.   int (*xExprCallback)(Walker*, Expr*);     /* Callback for expressions */

  18453.   int (*xSelectCallback)(Walker*,Select*);  /* Callback for SELECTs */

  18454.   void (*xSelectCallback2)(Walker*,Select*);/* Second callback for SELECTs */

  18455.   int walkerDepth;                          /* Number of subqueries */

  18456.   u8 eCode;                                 /* A small processing code */

  18457.   union {                                   /* Extra data for callback */

  18458.     NameContext *pNC;                         /* Naming context */

  18459.     int n;                                    /* A counter */

  18460.     int iCur;                                 /* A cursor number */

  18461.     SrcList *pSrcList;                        /* FROM clause */

  18462.     struct SrcCount *pSrcCount;               /* Counting column references */

  18463.     struct CCurHint *pCCurHint;               /* Used by codeCursorHint() */

  18464.     int *aiCol;                               /* array of column indexes */

  18465.     struct IdxCover *pIdxCover;               /* Check for index coverage */

  18466.     struct IdxExprTrans *pIdxTrans;           /* Convert idxed expr to column */

  18467.     ExprList *pGroupBy;                       /* GROUP BY clause */

  18468.     Select *pSelect;                          /* HAVING to WHERE clause ctx */

  18469.     struct WindowRewrite *pRewrite;           /* Window rewrite context */

  18470.     struct WhereConst *pConst;                /* WHERE clause constants */

  18471.     struct RenameCtx *pRename;                /* RENAME COLUMN context */

  18472.   } u;

  18473. };

  18474. 

  18475. /* Forward declarations */

  18476. SQLITE_PRIVATE int sqlite3WalkExpr(Walker*, Expr*);

  18477. SQLITE_PRIVATE int sqlite3WalkExprList(Walker*, ExprList*);

  18478. SQLITE_PRIVATE int sqlite3WalkSelect(Walker*, Select*);

  18479. SQLITE_PRIVATE int sqlite3WalkSelectExpr(Walker*, Select*);

  18480. SQLITE_PRIVATE int sqlite3WalkSelectFrom(Walker*, Select*);

  18481. SQLITE_PRIVATE int sqlite3ExprWalkNoop(Walker*, Expr*);

  18482. SQLITE_PRIVATE int sqlite3SelectWalkNoop(Walker*, Select*);

  18483. SQLITE_PRIVATE int sqlite3SelectWalkFail(Walker*, Select*);

  18484. #ifdef SQLITE_DEBUG

  18485. SQLITE_PRIVATE void sqlite3SelectWalkAssert2(Walker*, Select*);

  18486. #endif

  18487. 

  18488. /*

  18489. ** Return code from the parse-tree walking primitives and their

  18490. ** callbacks.

  18491. */

  18492. #define WRC_Continue    0   /* Continue down into children */

  18493. #define WRC_Prune       1   /* Omit children but continue walking siblings */

  18494. #define WRC_Abort       2   /* Abandon the tree walk */

  18495. 

  18496. /*

  18497. ** An instance of this structure represents a set of one or more CTEs

  18498. ** (common table expressions) created by a single WITH clause.

  18499. */

  18500. struct With {

  18501.   int nCte;                       /* Number of CTEs in the WITH clause */

  18502.   With *pOuter;                   /* Containing WITH clause, or NULL */

  18503.   struct Cte {                    /* For each CTE in the WITH clause.... */

  18504.     char *zName;                    /* Name of this CTE */

  18505.     ExprList *pCols;                /* List of explicit column names, or NULL */

  18506.     Select *pSelect;                /* The definition of this CTE */

  18507.     const char *zCteErr;            /* Error message for circular references */

  18508.   } a[1];

  18509. };

  18510. 

  18511. #ifdef SQLITE_DEBUG

  18512. /*

  18513. ** An instance of the TreeView object is used for printing the content of

  18514. ** data structures on sqlite3DebugPrintf() using a tree-like view.

  18515. */

  18516. struct TreeView {

  18517.   int iLevel;             /* Which level of the tree we are on */

  18518.   u8  bLine[100];         /* Draw vertical in column i if bLine[i] is true */

  18519. };

  18520. #endif /* SQLITE_DEBUG */

  18521. 

  18522. /*

  18523. ** This object is used in various ways, all related to window functions

  18524. **

  18525. **   (1) A single instance of this structure is attached to the

  18526. **       the Expr.pWin field for each window function in an expression tree.

  18527. **       This object holds the information contained in the OVER clause,

  18528. **       plus additional fields used during code generation.

  18529. **

  18530. **   (2) All window functions in a single SELECT form a linked-list

  18531. **       attached to Select.pWin.  The Window.pFunc and Window.pExpr

  18532. **       fields point back to the expression that is the window function.

  18533. **

  18534. **   (3) The terms of the WINDOW clause of a SELECT are instances of this

  18535. **       object on a linked list attached to Select.pWinDefn.

  18536. **

  18537. ** The uses (1) and (2) are really the same Window object that just happens

  18538. ** to be accessible in two different ways.  Use case (3) are separate objects.

  18539. */

  18540. struct Window {

  18541.   char *zName;            /* Name of window (may be NULL) */

  18542.   char *zBase;            /* Name of base window for chaining (may be NULL) */

  18543.   ExprList *pPartition;   /* PARTITION BY clause */

  18544.   ExprList *pOrderBy;     /* ORDER BY clause */

  18545.   u8 eFrmType;            /* TK_RANGE, TK_GROUPS, TK_ROWS, or 0 */

  18546.   u8 eStart;              /* UNBOUNDED, CURRENT, PRECEDING or FOLLOWING */

  18547.   u8 eEnd;                /* UNBOUNDED, CURRENT, PRECEDING or FOLLOWING */

  18548.   u8 bImplicitFrame;      /* True if frame was implicitly specified */

  18549.   u8 eExclude;            /* TK_NO, TK_CURRENT, TK_TIES, TK_GROUP, or 0 */

  18550.   Expr *pStart;           /* Expression for "<expr> PRECEDING" */

  18551.   Expr *pEnd;             /* Expression for "<expr> FOLLOWING" */

  18552.   Window *pNextWin;       /* Next window function belonging to this SELECT */

  18553.   Expr *pFilter;          /* The FILTER expression */

  18554.   FuncDef *pFunc;         /* The function */

  18555.   int iEphCsr;            /* Partition buffer or Peer buffer */

  18556.   int regAccum;

  18557.   int regResult;

  18558.   int csrApp;             /* Function cursor (used by min/max) */

  18559.   int regApp;             /* Function register (also used by min/max) */

  18560.   int regPart;            /* Array of registers for PARTITION BY values */

  18561.   Expr *pOwner;           /* Expression object this window is attached to */

  18562.   int nBufferCol;         /* Number of columns in buffer table */

  18563.   int iArgCol;            /* Offset of first argument for this function */

  18564.   int regOne;             /* Register containing constant value 1 */

  18565.   int regStartRowid;

  18566.   int regEndRowid;

  18567. };

  18568. 

  18569. #ifndef SQLITE_OMIT_WINDOWFUNC

  18570. SQLITE_PRIVATE void sqlite3WindowDelete(sqlite3*, Window*);

  18571. SQLITE_PRIVATE void sqlite3WindowListDelete(sqlite3 *db, Window *p);

  18572. SQLITE_PRIVATE Window *sqlite3WindowAlloc(Parse*, int, int, Expr*, int , Expr*, u8);

  18573. SQLITE_PRIVATE void sqlite3WindowAttach(Parse*, Expr*, Window*);

  18574. SQLITE_PRIVATE int sqlite3WindowCompare(Parse*, Window*, Window*);

  18575. SQLITE_PRIVATE void sqlite3WindowCodeInit(Parse*, Window*);

  18576. SQLITE_PRIVATE void sqlite3WindowCodeStep(Parse*, Select*, WhereInfo*, int, int);

  18577. SQLITE_PRIVATE int sqlite3WindowRewrite(Parse*, Select*);

  18578. SQLITE_PRIVATE int sqlite3ExpandSubquery(Parse*, struct SrcList_item*);

  18579. SQLITE_PRIVATE void sqlite3WindowUpdate(Parse*, Window*, Window*, FuncDef*);

  18580. SQLITE_PRIVATE Window *sqlite3WindowDup(sqlite3 *db, Expr *pOwner, Window *p);

  18581. SQLITE_PRIVATE Window *sqlite3WindowListDup(sqlite3 *db, Window *p);

  18582. SQLITE_PRIVATE void sqlite3WindowFunctions(void);

  18583. SQLITE_PRIVATE void sqlite3WindowChain(Parse*, Window*, Window*);

  18584. SQLITE_PRIVATE Window *sqlite3WindowAssemble(Parse*, Window*, ExprList*, ExprList*, Token*);

  18585. #else

  18586. # define sqlite3WindowDelete(a,b)

  18587. # define sqlite3WindowFunctions()

  18588. # define sqlite3WindowAttach(a,b,c)

  18589. #endif

  18590. 

  18591. /*

  18592. ** Assuming zIn points to the first byte of a UTF-8 character,

  18593. ** advance zIn to point to the first byte of the next UTF-8 character.

  18594. */

  18595. #define SQLITE_SKIP_UTF8(zIn) {                        \

  18596.   if( (*(zIn++))>=0xc0 ){                              \

  18597.     while( (*zIn & 0xc0)==0x80 ){ zIn++; }             \

  18598.   }                                                    \

  18599. }

  18600. 

  18601. /*

  18602. ** The SQLITE_*_BKPT macros are substitutes for the error codes with

  18603. ** the same name but without the _BKPT suffix.  These macros invoke

  18604. ** routines that report the line-number on which the error originated

  18605. ** using sqlite3_log().  The routines also provide a convenient place

  18606. ** to set a debugger breakpoint.

  18607. */

  18608. SQLITE_PRIVATE int sqlite3ReportError(int iErr, int lineno, const char *zType);

  18609. SQLITE_PRIVATE int sqlite3CorruptError(int);

  18610. SQLITE_PRIVATE int sqlite3MisuseError(int);

  18611. SQLITE_PRIVATE int sqlite3CantopenError(int);

  18612. #define SQLITE_CORRUPT_BKPT sqlite3CorruptError(__LINE__)

  18613. #define SQLITE_MISUSE_BKPT sqlite3MisuseError(__LINE__)

  18614. #define SQLITE_CANTOPEN_BKPT sqlite3CantopenError(__LINE__)

  18615. #ifdef SQLITE_DEBUG

  18616. SQLITE_PRIVATE   int sqlite3NomemError(int);

  18617. SQLITE_PRIVATE   int sqlite3IoerrnomemError(int);

  18618. SQLITE_PRIVATE   int sqlite3CorruptPgnoError(int,Pgno);

  18619. # define SQLITE_NOMEM_BKPT sqlite3NomemError(__LINE__)

  18620. # define SQLITE_IOERR_NOMEM_BKPT sqlite3IoerrnomemError(__LINE__)

  18621. # define SQLITE_CORRUPT_PGNO(P) sqlite3CorruptPgnoError(__LINE__,(P))

  18622. #else

  18623. # define SQLITE_NOMEM_BKPT SQLITE_NOMEM

  18624. # define SQLITE_IOERR_NOMEM_BKPT SQLITE_IOERR_NOMEM

  18625. # define SQLITE_CORRUPT_PGNO(P) sqlite3CorruptError(__LINE__)

  18626. #endif

  18627. 

  18628. /*

  18629. ** FTS3 and FTS4 both require virtual table support

  18630. */

  18631. #if defined(SQLITE_OMIT_VIRTUALTABLE)

  18632. # undef SQLITE_ENABLE_FTS3

  18633. # undef SQLITE_ENABLE_FTS4

  18634. #endif

  18635. 

  18636. /*

  18637. ** FTS4 is really an extension for FTS3.  It is enabled using the

  18638. ** SQLITE_ENABLE_FTS3 macro.  But to avoid confusion we also call

  18639. ** the SQLITE_ENABLE_FTS4 macro to serve as an alias for SQLITE_ENABLE_FTS3.

  18640. */

  18641. #if defined(SQLITE_ENABLE_FTS4) && !defined(SQLITE_ENABLE_FTS3)

  18642. # define SQLITE_ENABLE_FTS3 1

  18643. #endif

  18644. 

  18645. /*

  18646. ** The ctype.h header is needed for non-ASCII systems.  It is also

  18647. ** needed by FTS3 when FTS3 is included in the amalgamation.

  18648. */

  18649. #if !defined(SQLITE_ASCII) || \

  18650.     (defined(SQLITE_ENABLE_FTS3) && defined(SQLITE_AMALGAMATION))

  18651. # include <ctype.h>

  18652. #endif

  18653. 

  18654. /*

  18655. ** The following macros mimic the standard library functions toupper(),

  18656. ** isspace(), isalnum(), isdigit() and isxdigit(), respectively. The

  18657. ** sqlite versions only work for ASCII characters, regardless of locale.

  18658. */

  18659. #ifdef SQLITE_ASCII

  18660. # define sqlite3Toupper(x)  ((x)&~(sqlite3CtypeMap[(unsigned char)(x)]&0x20))

  18661. # define sqlite3Isspace(x)   (sqlite3CtypeMap[(unsigned char)(x)]&0x01)

  18662. # define sqlite3Isalnum(x)   (sqlite3CtypeMap[(unsigned char)(x)]&0x06)

  18663. # define sqlite3Isalpha(x)   (sqlite3CtypeMap[(unsigned char)(x)]&0x02)

  18664. # define sqlite3Isdigit(x)   (sqlite3CtypeMap[(unsigned char)(x)]&0x04)

  18665. # define sqlite3Isxdigit(x)  (sqlite3CtypeMap[(unsigned char)(x)]&0x08)

  18666. # define sqlite3Tolower(x)   (sqlite3UpperToLower[(unsigned char)(x)])

  18667. # define sqlite3Isquote(x)   (sqlite3CtypeMap[(unsigned char)(x)]&0x80)

  18668. #else

  18669. # define sqlite3Toupper(x)   toupper((unsigned char)(x))

  18670. # define sqlite3Isspace(x)   isspace((unsigned char)(x))

  18671. # define sqlite3Isalnum(x)   isalnum((unsigned char)(x))

  18672. # define sqlite3Isalpha(x)   isalpha((unsigned char)(x))

  18673. # define sqlite3Isdigit(x)   isdigit((unsigned char)(x))

  18674. # define sqlite3Isxdigit(x)  isxdigit((unsigned char)(x))

  18675. # define sqlite3Tolower(x)   tolower((unsigned char)(x))

  18676. # define sqlite3Isquote(x)   ((x)=='"'||(x)=='\''||(x)=='['||(x)=='`')

  18677. #endif

  18678. SQLITE_PRIVATE int sqlite3IsIdChar(u8);

  18679. 

  18680. /*

  18681. ** Internal function prototypes

  18682. */

  18683. SQLITE_PRIVATE int sqlite3StrICmp(const char*,const char*);

  18684. SQLITE_PRIVATE int sqlite3Strlen30(const char*);

  18685. #define sqlite3Strlen30NN(C) (strlen(C)&0x3fffffff)

  18686. SQLITE_PRIVATE char *sqlite3ColumnType(Column*,char*);

  18687. #define sqlite3StrNICmp sqlite3_strnicmp

  18688. 

  18689. SQLITE_PRIVATE int sqlite3MallocInit(void);

  18690. SQLITE_PRIVATE void sqlite3MallocEnd(void);

  18691. SQLITE_PRIVATE void *sqlite3Malloc(u64);

  18692. SQLITE_PRIVATE void *sqlite3MallocZero(u64);

  18693. SQLITE_PRIVATE void *sqlite3DbMallocZero(sqlite3*, u64);

  18694. SQLITE_PRIVATE void *sqlite3DbMallocRaw(sqlite3*, u64);

  18695. SQLITE_PRIVATE void *sqlite3DbMallocRawNN(sqlite3*, u64);

  18696. SQLITE_PRIVATE char *sqlite3DbStrDup(sqlite3*,const char*);

  18697. SQLITE_PRIVATE char *sqlite3DbStrNDup(sqlite3*,const char*, u64);

  18698. SQLITE_PRIVATE char *sqlite3DbSpanDup(sqlite3*,const char*,const char*);

  18699. SQLITE_PRIVATE void *sqlite3Realloc(void*, u64);

  18700. SQLITE_PRIVATE void *sqlite3DbReallocOrFree(sqlite3 *, void *, u64);

  18701. SQLITE_PRIVATE void *sqlite3DbRealloc(sqlite3 *, void *, u64);

  18702. SQLITE_PRIVATE void sqlite3DbFree(sqlite3*, void*);

  18703. SQLITE_PRIVATE void sqlite3DbFreeNN(sqlite3*, void*);

  18704. SQLITE_PRIVATE int sqlite3MallocSize(void*);

  18705. SQLITE_PRIVATE int sqlite3DbMallocSize(sqlite3*, void*);

  18706. SQLITE_PRIVATE void *sqlite3PageMalloc(int);

  18707. SQLITE_PRIVATE void sqlite3PageFree(void*);

  18708. SQLITE_PRIVATE void sqlite3MemSetDefault(void);

  18709. #ifndef SQLITE_UNTESTABLE

  18710. SQLITE_PRIVATE void sqlite3BenignMallocHooks(void (*)(void), void (*)(void));

  18711. #endif

  18712. SQLITE_PRIVATE int sqlite3HeapNearlyFull(void);

  18713. 

  18714. /*

  18715. ** On systems with ample stack space and that support alloca(), make

  18716. ** use of alloca() to obtain space for large automatic objects.  By default,

  18717. ** obtain space from malloc().

  18718. **

  18719. ** The alloca() routine never returns NULL.  This will cause code paths

  18720. ** that deal with sqlite3StackAlloc() failures to be unreachable.

  18721. */

  18722. #ifdef SQLITE_USE_ALLOCA

  18723. # define sqlite3StackAllocRaw(D,N)   alloca(N)

  18724. # define sqlite3StackAllocZero(D,N)  memset(alloca(N), 0, N)

  18725. # define sqlite3StackFree(D,P)

  18726. #else

  18727. # define sqlite3StackAllocRaw(D,N)   sqlite3DbMallocRaw(D,N)

  18728. # define sqlite3StackAllocZero(D,N)  sqlite3DbMallocZero(D,N)

  18729. # define sqlite3StackFree(D,P)       sqlite3DbFree(D,P)

  18730. #endif

  18731. 

  18732. /* Do not allow both MEMSYS5 and MEMSYS3 to be defined together.  If they

  18733. ** are, disable MEMSYS3

  18734. */

  18735. #ifdef SQLITE_ENABLE_MEMSYS5

  18736. SQLITE_PRIVATE const sqlite3_mem_methods *sqlite3MemGetMemsys5(void);

  18737. #undef SQLITE_ENABLE_MEMSYS3

  18738. #endif

  18739. #ifdef SQLITE_ENABLE_MEMSYS3

  18740. SQLITE_PRIVATE const sqlite3_mem_methods *sqlite3MemGetMemsys3(void);

  18741. #endif

  18742. 

  18743. 

  18744. #ifndef SQLITE_MUTEX_OMIT

  18745. SQLITE_PRIVATE   sqlite3_mutex_methods const *sqlite3DefaultMutex(void);

  18746. SQLITE_PRIVATE   sqlite3_mutex_methods const *sqlite3NoopMutex(void);

  18747. SQLITE_PRIVATE   sqlite3_mutex *sqlite3MutexAlloc(int);

  18748. SQLITE_PRIVATE   int sqlite3MutexInit(void);

  18749. SQLITE_PRIVATE   int sqlite3MutexEnd(void);

  18750. #endif

  18751. #if !defined(SQLITE_MUTEX_OMIT) && !defined(SQLITE_MUTEX_NOOP)

  18752. SQLITE_PRIVATE   void sqlite3MemoryBarrier(void);

  18753. #else

  18754. # define sqlite3MemoryBarrier()

  18755. #endif

  18756. 

  18757. SQLITE_PRIVATE sqlite3_int64 sqlite3StatusValue(int);

  18758. SQLITE_PRIVATE void sqlite3StatusUp(int, int);

  18759. SQLITE_PRIVATE void sqlite3StatusDown(int, int);

  18760. SQLITE_PRIVATE void sqlite3StatusHighwater(int, int);

  18761. SQLITE_PRIVATE int sqlite3LookasideUsed(sqlite3*,int*);

  18762. 

  18763. /* Access to mutexes used by sqlite3_status() */

  18764. SQLITE_PRIVATE sqlite3_mutex *sqlite3Pcache1Mutex(void);

  18765. SQLITE_PRIVATE sqlite3_mutex *sqlite3MallocMutex(void);

  18766. 

  18767. #if defined(SQLITE_ENABLE_MULTITHREADED_CHECKS) && !defined(SQLITE_MUTEX_OMIT)

  18768. SQLITE_PRIVATE void sqlite3MutexWarnOnContention(sqlite3_mutex*);

  18769. #else

  18770. # define sqlite3MutexWarnOnContention(x)

  18771. #endif

  18772. 

  18773. #ifndef SQLITE_OMIT_FLOATING_POINT

  18774. # define EXP754 (((u64)0x7ff)<<52)

  18775. # define MAN754 ((((u64)1)<<52)-1)

  18776. # define IsNaN(X) (((X)&EXP754)==EXP754 && ((X)&MAN754)!=0)

  18777. SQLITE_PRIVATE   int sqlite3IsNaN(double);

  18778. #else

  18779. # define IsNaN(X)         0

  18780. # define sqlite3IsNaN(X)  0

  18781. #endif

  18782. 

  18783. /*

  18784. ** An instance of the following structure holds information about SQL

  18785. ** functions arguments that are the parameters to the printf() function.

  18786. */

  18787. struct PrintfArguments {

  18788.   int nArg;                /* Total number of arguments */

  18789.   int nUsed;               /* Number of arguments used so far */

  18790.   sqlite3_value **apArg;   /* The argument values */

  18791. };

  18792. 

  18793. SQLITE_PRIVATE char *sqlite3MPrintf(sqlite3*,const char*, ...);

  18794. SQLITE_PRIVATE char *sqlite3VMPrintf(sqlite3*,const char*, va_list);

  18795. #if defined(SQLITE_DEBUG) || defined(SQLITE_HAVE_OS_TRACE)

  18796. SQLITE_PRIVATE   void sqlite3DebugPrintf(const char*, ...);

  18797. #endif

  18798. #if defined(SQLITE_TEST)

  18799. SQLITE_PRIVATE   void *sqlite3TestTextToPtr(const char*);

  18800. #endif

  18801. 

  18802. #if defined(SQLITE_DEBUG)

  18803. SQLITE_PRIVATE   void sqlite3TreeViewExpr(TreeView*, const Expr*, u8);

  18804. SQLITE_PRIVATE   void sqlite3TreeViewBareExprList(TreeView*, const ExprList*, const char*);

  18805. SQLITE_PRIVATE   void sqlite3TreeViewExprList(TreeView*, const ExprList*, u8, const char*);

  18806. SQLITE_PRIVATE   void sqlite3TreeViewSrcList(TreeView*, const SrcList*);

  18807. SQLITE_PRIVATE   void sqlite3TreeViewSelect(TreeView*, const Select*, u8);

  18808. SQLITE_PRIVATE   void sqlite3TreeViewWith(TreeView*, const With*, u8);

  18809. #ifndef SQLITE_OMIT_WINDOWFUNC

  18810. SQLITE_PRIVATE   void sqlite3TreeViewWindow(TreeView*, const Window*, u8);

  18811. SQLITE_PRIVATE   void sqlite3TreeViewWinFunc(TreeView*, const Window*, u8);

  18812. #endif

  18813. #endif

  18814. 

  18815. 

  18816. SQLITE_PRIVATE void sqlite3SetString(char **, sqlite3*, const char*);

  18817. SQLITE_PRIVATE void sqlite3ErrorMsg(Parse*, const char*, ...);

  18818. SQLITE_PRIVATE int sqlite3ErrorToParser(sqlite3*,int);

  18819. SQLITE_PRIVATE void sqlite3Dequote(char*);

  18820. SQLITE_PRIVATE void sqlite3DequoteExpr(Expr*);

  18821. SQLITE_PRIVATE void sqlite3TokenInit(Token*,char*);

  18822. SQLITE_PRIVATE int sqlite3KeywordCode(const unsigned char*, int);

  18823. SQLITE_PRIVATE int sqlite3RunParser(Parse*, const char*, char **);

  18824. SQLITE_PRIVATE void sqlite3FinishCoding(Parse*);

  18825. SQLITE_PRIVATE int sqlite3GetTempReg(Parse*);

  18826. SQLITE_PRIVATE void sqlite3ReleaseTempReg(Parse*,int);

  18827. SQLITE_PRIVATE int sqlite3GetTempRange(Parse*,int);

  18828. SQLITE_PRIVATE void sqlite3ReleaseTempRange(Parse*,int,int);

  18829. SQLITE_PRIVATE void sqlite3ClearTempRegCache(Parse*);

  18830. #ifdef SQLITE_DEBUG

  18831. SQLITE_PRIVATE int sqlite3NoTempsInRange(Parse*,int,int);

  18832. #endif

  18833. SQLITE_PRIVATE Expr *sqlite3ExprAlloc(sqlite3*,int,const Token*,int);

  18834. SQLITE_PRIVATE Expr *sqlite3Expr(sqlite3*,int,const char*);

  18835. SQLITE_PRIVATE void sqlite3ExprAttachSubtrees(sqlite3*,Expr*,Expr*,Expr*);

  18836. SQLITE_PRIVATE Expr *sqlite3PExpr(Parse*, int, Expr*, Expr*);

  18837. SQLITE_PRIVATE void sqlite3PExprAddSelect(Parse*, Expr*, Select*);

  18838. SQLITE_PRIVATE Expr *sqlite3ExprAnd(Parse*,Expr*, Expr*);

  18839. SQLITE_PRIVATE Expr *sqlite3ExprSimplifiedAndOr(Expr*);

  18840. SQLITE_PRIVATE Expr *sqlite3ExprFunction(Parse*,ExprList*, Token*, int);

  18841. SQLITE_PRIVATE void sqlite3ExprAssignVarNumber(Parse*, Expr*, u32);

  18842. SQLITE_PRIVATE void sqlite3ExprDelete(sqlite3*, Expr*);

  18843. SQLITE_PRIVATE void sqlite3ExprUnmapAndDelete(Parse*, Expr*);

  18844. SQLITE_PRIVATE ExprList *sqlite3ExprListAppend(Parse*,ExprList*,Expr*);

  18845. SQLITE_PRIVATE ExprList *sqlite3ExprListAppendVector(Parse*,ExprList*,IdList*,Expr*);

  18846. SQLITE_PRIVATE void sqlite3ExprListSetSortOrder(ExprList*,int);

  18847. SQLITE_PRIVATE void sqlite3ExprListSetName(Parse*,ExprList*,Token*,int);

  18848. SQLITE_PRIVATE void sqlite3ExprListSetSpan(Parse*,ExprList*,const char*,const char*);

  18849. SQLITE_PRIVATE void sqlite3ExprListDelete(sqlite3*, ExprList*);

  18850. SQLITE_PRIVATE u32 sqlite3ExprListFlags(const ExprList*);

  18851. SQLITE_PRIVATE int sqlite3IndexHasDuplicateRootPage(Index*);

  18852. SQLITE_PRIVATE int sqlite3Init(sqlite3*, char**);

  18853. SQLITE_PRIVATE int sqlite3InitCallback(void*, int, char**, char**);

  18854. SQLITE_PRIVATE int sqlite3InitOne(sqlite3*, int, char**, u32);

  18855. SQLITE_PRIVATE void sqlite3Pragma(Parse*,Token*,Token*,Token*,int);

  18856. #ifndef SQLITE_OMIT_VIRTUALTABLE

  18857. SQLITE_PRIVATE Module *sqlite3PragmaVtabRegister(sqlite3*,const char *zName);

  18858. #endif

  18859. SQLITE_PRIVATE void sqlite3ResetAllSchemasOfConnection(sqlite3*);

  18860. SQLITE_PRIVATE void sqlite3ResetOneSchema(sqlite3*,int);

  18861. SQLITE_PRIVATE void sqlite3CollapseDatabaseArray(sqlite3*);

  18862. SQLITE_PRIVATE void sqlite3CommitInternalChanges(sqlite3*);

  18863. SQLITE_PRIVATE void sqlite3DeleteColumnNames(sqlite3*,Table*);

  18864. SQLITE_PRIVATE int sqlite3ColumnsFromExprList(Parse*,ExprList*,i16*,Column**);

  18865. SQLITE_PRIVATE void sqlite3SelectAddColumnTypeAndCollation(Parse*,Table*,Select*);

  18866. SQLITE_PRIVATE Table *sqlite3ResultSetOfSelect(Parse*,Select*);

  18867. SQLITE_PRIVATE void sqlite3OpenMasterTable(Parse *, int);

  18868. SQLITE_PRIVATE Index *sqlite3PrimaryKeyIndex(Table*);

  18869. SQLITE_PRIVATE i16 sqlite3ColumnOfIndex(Index*, i16);

  18870. SQLITE_PRIVATE void sqlite3StartTable(Parse*,Token*,Token*,int,int,int,int);

  18871. #if SQLITE_ENABLE_HIDDEN_COLUMNS

  18872. SQLITE_PRIVATE   void sqlite3ColumnPropertiesFromName(Table*, Column*);

  18873. #else

  18874. # define sqlite3ColumnPropertiesFromName(T,C) /* no-op */

  18875. #endif

  18876. SQLITE_PRIVATE void sqlite3AddColumn(Parse*,Token*,Token*);

  18877. SQLITE_PRIVATE void sqlite3AddNotNull(Parse*, int);

  18878. SQLITE_PRIVATE void sqlite3AddPrimaryKey(Parse*, ExprList*, int, int, int);

  18879. SQLITE_PRIVATE void sqlite3AddCheckConstraint(Parse*, Expr*);

  18880. SQLITE_PRIVATE void sqlite3AddDefaultValue(Parse*,Expr*,const char*,const char*);

  18881. SQLITE_PRIVATE void sqlite3AddCollateType(Parse*, Token*);

  18882. SQLITE_PRIVATE void sqlite3EndTable(Parse*,Token*,Token*,u8,Select*);

  18883. SQLITE_PRIVATE int sqlite3ParseUri(const char*,const char*,unsigned int*,

  18884.                     sqlite3_vfs**,char**,char **);

  18885. #ifdef SQLITE_HAS_CODEC

  18886. SQLITE_PRIVATE   int sqlite3CodecQueryParameters(sqlite3*,const char*,const char*);

  18887. #else

  18888. # define sqlite3CodecQueryParameters(A,B,C) 0

  18889. #endif

  18890. SQLITE_PRIVATE Btree *sqlite3DbNameToBtree(sqlite3*,const char*);

  18891. 

  18892. #ifdef SQLITE_UNTESTABLE

  18893. # define sqlite3FaultSim(X) SQLITE_OK

  18894. #else

  18895. SQLITE_PRIVATE   int sqlite3FaultSim(int);

  18896. #endif

  18897. 

  18898. SQLITE_PRIVATE Bitvec *sqlite3BitvecCreate(u32);

  18899. SQLITE_PRIVATE int sqlite3BitvecTest(Bitvec*, u32);

  18900. SQLITE_PRIVATE int sqlite3BitvecTestNotNull(Bitvec*, u32);

  18901. SQLITE_PRIVATE int sqlite3BitvecSet(Bitvec*, u32);

  18902. SQLITE_PRIVATE void sqlite3BitvecClear(Bitvec*, u32, void*);

  18903. SQLITE_PRIVATE void sqlite3BitvecDestroy(Bitvec*);

  18904. SQLITE_PRIVATE u32 sqlite3BitvecSize(Bitvec*);

  18905. #ifndef SQLITE_UNTESTABLE

  18906. SQLITE_PRIVATE int sqlite3BitvecBuiltinTest(int,int*);

  18907. #endif

  18908. 

  18909. SQLITE_PRIVATE RowSet *sqlite3RowSetInit(sqlite3*);

  18910. SQLITE_PRIVATE void sqlite3RowSetDelete(void*);

  18911. SQLITE_PRIVATE void sqlite3RowSetClear(void*);

  18912. SQLITE_PRIVATE void sqlite3RowSetInsert(RowSet*, i64);

  18913. SQLITE_PRIVATE int sqlite3RowSetTest(RowSet*, int iBatch, i64);

  18914. SQLITE_PRIVATE int sqlite3RowSetNext(RowSet*, i64*);

  18915. 

  18916. SQLITE_PRIVATE void sqlite3CreateView(Parse*,Token*,Token*,Token*,ExprList*,Select*,int,int);

  18917. 

  18918. #if !defined(SQLITE_OMIT_VIEW) || !defined(SQLITE_OMIT_VIRTUALTABLE)

  18919. SQLITE_PRIVATE   int sqlite3ViewGetColumnNames(Parse*,Table*);

  18920. #else

  18921. # define sqlite3ViewGetColumnNames(A,B) 0

  18922. #endif

  18923. 

  18924. #if SQLITE_MAX_ATTACHED>30

  18925. SQLITE_PRIVATE   int sqlite3DbMaskAllZero(yDbMask);

  18926. #endif

  18927. SQLITE_PRIVATE void sqlite3DropTable(Parse*, SrcList*, int, int);

  18928. SQLITE_PRIVATE void sqlite3CodeDropTable(Parse*, Table*, int, int);

  18929. SQLITE_PRIVATE void sqlite3DeleteTable(sqlite3*, Table*);

  18930. SQLITE_PRIVATE void sqlite3FreeIndex(sqlite3*, Index*);

  18931. #ifndef SQLITE_OMIT_AUTOINCREMENT

  18932. SQLITE_PRIVATE   void sqlite3AutoincrementBegin(Parse *pParse);

  18933. SQLITE_PRIVATE   void sqlite3AutoincrementEnd(Parse *pParse);

  18934. #else

  18935. # define sqlite3AutoincrementBegin(X)

  18936. # define sqlite3AutoincrementEnd(X)

  18937. #endif

  18938. SQLITE_PRIVATE void sqlite3Insert(Parse*, SrcList*, Select*, IdList*, int, Upsert*);

  18939. SQLITE_PRIVATE void *sqlite3ArrayAllocate(sqlite3*,void*,int,int*,int*);

  18940. SQLITE_PRIVATE IdList *sqlite3IdListAppend(Parse*, IdList*, Token*);

  18941. SQLITE_PRIVATE int sqlite3IdListIndex(IdList*,const char*);

  18942. SQLITE_PRIVATE SrcList *sqlite3SrcListEnlarge(Parse*, SrcList*, int, int);

  18943. SQLITE_PRIVATE SrcList *sqlite3SrcListAppend(Parse*, SrcList*, Token*, Token*);

  18944. SQLITE_PRIVATE SrcList *sqlite3SrcListAppendFromTerm(Parse*, SrcList*, Token*, Token*,

  18945.                                       Token*, Select*, Expr*, IdList*);

  18946. SQLITE_PRIVATE void sqlite3SrcListIndexedBy(Parse *, SrcList *, Token *);

  18947. SQLITE_PRIVATE void sqlite3SrcListFuncArgs(Parse*, SrcList*, ExprList*);

  18948. SQLITE_PRIVATE int sqlite3IndexedByLookup(Parse *, struct SrcList_item *);

  18949. SQLITE_PRIVATE void sqlite3SrcListShiftJoinType(SrcList*);

  18950. SQLITE_PRIVATE void sqlite3SrcListAssignCursors(Parse*, SrcList*);

  18951. SQLITE_PRIVATE void sqlite3IdListDelete(sqlite3*, IdList*);

  18952. SQLITE_PRIVATE void sqlite3SrcListDelete(sqlite3*, SrcList*);

  18953. SQLITE_PRIVATE Index *sqlite3AllocateIndexObject(sqlite3*,i16,int,char**);

  18954. SQLITE_PRIVATE void sqlite3CreateIndex(Parse*,Token*,Token*,SrcList*,ExprList*,int,Token*,

  18955.                           Expr*, int, int, u8);

  18956. SQLITE_PRIVATE void sqlite3DropIndex(Parse*, SrcList*, int);

  18957. SQLITE_PRIVATE int sqlite3Select(Parse*, Select*, SelectDest*);

  18958. SQLITE_PRIVATE Select *sqlite3SelectNew(Parse*,ExprList*,SrcList*,Expr*,ExprList*,

  18959.                          Expr*,ExprList*,u32,Expr*);

  18960. SQLITE_PRIVATE void sqlite3SelectDelete(sqlite3*, Select*);

  18961. SQLITE_PRIVATE Table *sqlite3SrcListLookup(Parse*, SrcList*);

  18962. SQLITE_PRIVATE int sqlite3IsReadOnly(Parse*, Table*, int);

  18963. SQLITE_PRIVATE void sqlite3OpenTable(Parse*, int iCur, int iDb, Table*, int);

  18964. #if defined(SQLITE_ENABLE_UPDATE_DELETE_LIMIT) && !defined(SQLITE_OMIT_SUBQUERY)

  18965. SQLITE_PRIVATE Expr *sqlite3LimitWhere(Parse*,SrcList*,Expr*,ExprList*,Expr*,char*);

  18966. #endif

  18967. SQLITE_PRIVATE void sqlite3DeleteFrom(Parse*, SrcList*, Expr*, ExprList*, Expr*);

  18968. SQLITE_PRIVATE void sqlite3Update(Parse*, SrcList*, ExprList*,Expr*,int,ExprList*,Expr*,

  18969.                    Upsert*);

  18970. SQLITE_PRIVATE WhereInfo *sqlite3WhereBegin(Parse*,SrcList*,Expr*,ExprList*,ExprList*,u16,int);

  18971. SQLITE_PRIVATE void sqlite3WhereEnd(WhereInfo*);

  18972. SQLITE_PRIVATE LogEst sqlite3WhereOutputRowCount(WhereInfo*);

  18973. SQLITE_PRIVATE int sqlite3WhereIsDistinct(WhereInfo*);

  18974. SQLITE_PRIVATE int sqlite3WhereIsOrdered(WhereInfo*);

  18975. SQLITE_PRIVATE int sqlite3WhereOrderByLimitOptLabel(WhereInfo*);

  18976. SQLITE_PRIVATE int sqlite3WhereIsSorted(WhereInfo*);

  18977. SQLITE_PRIVATE int sqlite3WhereContinueLabel(WhereInfo*);

  18978. SQLITE_PRIVATE int sqlite3WhereBreakLabel(WhereInfo*);

  18979. SQLITE_PRIVATE int sqlite3WhereOkOnePass(WhereInfo*, int*);

  18980. #define ONEPASS_OFF      0        /* Use of ONEPASS not allowed */

  18981. #define ONEPASS_SINGLE   1        /* ONEPASS valid for a single row update */

  18982. #define ONEPASS_MULTI    2        /* ONEPASS is valid for multiple rows */

  18983. SQLITE_PRIVATE void sqlite3ExprCodeLoadIndexColumn(Parse*, Index*, int, int, int);

  18984. SQLITE_PRIVATE int sqlite3ExprCodeGetColumn(Parse*, Table*, int, int, int, u8);

  18985. SQLITE_PRIVATE void sqlite3ExprCodeGetColumnOfTable(Vdbe*, Table*, int, int, int);

  18986. SQLITE_PRIVATE void sqlite3ExprCodeMove(Parse*, int, int, int);

  18987. SQLITE_PRIVATE void sqlite3ExprCode(Parse*, Expr*, int);

  18988. SQLITE_PRIVATE void sqlite3ExprCodeCopy(Parse*, Expr*, int);

  18989. SQLITE_PRIVATE void sqlite3ExprCodeFactorable(Parse*, Expr*, int);

  18990. SQLITE_PRIVATE int sqlite3ExprCodeAtInit(Parse*, Expr*, int);

  18991. SQLITE_PRIVATE int sqlite3ExprCodeTemp(Parse*, Expr*, int*);

  18992. SQLITE_PRIVATE int sqlite3ExprCodeTarget(Parse*, Expr*, int);

  18993. SQLITE_PRIVATE void sqlite3ExprCodeAndCache(Parse*, Expr*, int);

  18994. SQLITE_PRIVATE int sqlite3ExprCodeExprList(Parse*, ExprList*, int, int, u8);

  18995. #define SQLITE_ECEL_DUP      0x01  /* Deep, not shallow copies */

  18996. #define SQLITE_ECEL_FACTOR   0x02  /* Factor out constant terms */

  18997. #define SQLITE_ECEL_REF      0x04  /* Use ExprList.u.x.iOrderByCol */

  18998. #define SQLITE_ECEL_OMITREF  0x08  /* Omit if ExprList.u.x.iOrderByCol */

  18999. SQLITE_PRIVATE void sqlite3ExprIfTrue(Parse*, Expr*, int, int);

  19000. SQLITE_PRIVATE void sqlite3ExprIfFalse(Parse*, Expr*, int, int);

  19001. SQLITE_PRIVATE void sqlite3ExprIfFalseDup(Parse*, Expr*, int, int);

  19002. SQLITE_PRIVATE Table *sqlite3FindTable(sqlite3*,const char*, const char*);

  19003. #define LOCATE_VIEW    0x01

  19004. #define LOCATE_NOERR   0x02

  19005. SQLITE_PRIVATE Table *sqlite3LocateTable(Parse*,u32 flags,const char*, const char*);

  19006. SQLITE_PRIVATE Table *sqlite3LocateTableItem(Parse*,u32 flags,struct SrcList_item *);

  19007. SQLITE_PRIVATE Index *sqlite3FindIndex(sqlite3*,const char*, const char*);

  19008. SQLITE_PRIVATE void sqlite3UnlinkAndDeleteTable(sqlite3*,int,const char*);

  19009. SQLITE_PRIVATE void sqlite3UnlinkAndDeleteIndex(sqlite3*,int,const char*);

  19010. SQLITE_PRIVATE void sqlite3Vacuum(Parse*,Token*,Expr*);

  19011. SQLITE_PRIVATE int sqlite3RunVacuum(char**, sqlite3*, int, sqlite3_value*);

  19012. SQLITE_PRIVATE char *sqlite3NameFromToken(sqlite3*, Token*);

  19013. SQLITE_PRIVATE int sqlite3ExprCompare(Parse*,Expr*, Expr*, int);

  19014. SQLITE_PRIVATE int sqlite3ExprCompareSkip(Expr*, Expr*, int);

  19015. SQLITE_PRIVATE int sqlite3ExprListCompare(ExprList*, ExprList*, int);

  19016. SQLITE_PRIVATE int sqlite3ExprImpliesExpr(Parse*,Expr*, Expr*, int);

  19017. SQLITE_PRIVATE int sqlite3ExprImpliesNonNullRow(Expr*,int);

  19018. SQLITE_PRIVATE void sqlite3ExprAnalyzeAggregates(NameContext*, Expr*);

  19019. SQLITE_PRIVATE void sqlite3ExprAnalyzeAggList(NameContext*,ExprList*);

  19020. SQLITE_PRIVATE int sqlite3ExprCoveredByIndex(Expr*, int iCur, Index *pIdx);

  19021. SQLITE_PRIVATE int sqlite3FunctionUsesThisSrc(Expr*, SrcList*);

  19022. SQLITE_PRIVATE Vdbe *sqlite3GetVdbe(Parse*);

  19023. #ifndef SQLITE_UNTESTABLE

  19024. SQLITE_PRIVATE void sqlite3PrngSaveState(void);

  19025. SQLITE_PRIVATE void sqlite3PrngRestoreState(void);

  19026. #endif

  19027. SQLITE_PRIVATE void sqlite3RollbackAll(sqlite3*,int);

  19028. SQLITE_PRIVATE void sqlite3CodeVerifySchema(Parse*, int);

  19029. SQLITE_PRIVATE void sqlite3CodeVerifyNamedSchema(Parse*, const char *zDb);

  19030. SQLITE_PRIVATE void sqlite3BeginTransaction(Parse*, int);

  19031. SQLITE_PRIVATE void sqlite3EndTransaction(Parse*,int);

  19032. SQLITE_PRIVATE void sqlite3Savepoint(Parse*, int, Token*);

  19033. SQLITE_PRIVATE void sqlite3CloseSavepoints(sqlite3 *);

  19034. SQLITE_PRIVATE void sqlite3LeaveMutexAndCloseZombie(sqlite3*);

  19035. SQLITE_PRIVATE int sqlite3ExprIdToTrueFalse(Expr*);

  19036. SQLITE_PRIVATE int sqlite3ExprTruthValue(const Expr*);

  19037. SQLITE_PRIVATE int sqlite3ExprIsConstant(Expr*);

  19038. SQLITE_PRIVATE int sqlite3ExprIsConstantNotJoin(Expr*);

  19039. SQLITE_PRIVATE int sqlite3ExprIsConstantOrFunction(Expr*, u8);

  19040. SQLITE_PRIVATE int sqlite3ExprIsConstantOrGroupBy(Parse*, Expr*, ExprList*);

  19041. SQLITE_PRIVATE int sqlite3ExprIsTableConstant(Expr*,int);

  19042. #ifdef SQLITE_ENABLE_CURSOR_HINTS

  19043. SQLITE_PRIVATE int sqlite3ExprContainsSubquery(Expr*);

  19044. #endif

  19045. SQLITE_PRIVATE int sqlite3ExprIsInteger(Expr*, int*);

  19046. SQLITE_PRIVATE int sqlite3ExprCanBeNull(const Expr*);

  19047. SQLITE_PRIVATE int sqlite3ExprNeedsNoAffinityChange(const Expr*, char);

  19048. SQLITE_PRIVATE int sqlite3IsRowid(const char*);

  19049. SQLITE_PRIVATE void sqlite3GenerateRowDelete(

  19050.     Parse*,Table*,Trigger*,int,int,int,i16,u8,u8,u8,int);

  19051. SQLITE_PRIVATE void sqlite3GenerateRowIndexDelete(Parse*, Table*, int, int, int*, int);

  19052. SQLITE_PRIVATE int sqlite3GenerateIndexKey(Parse*, Index*, int, int, int, int*,Index*,int);

  19053. SQLITE_PRIVATE void sqlite3ResolvePartIdxLabel(Parse*,int);

  19054. SQLITE_PRIVATE int sqlite3ExprReferencesUpdatedColumn(Expr*,int*,int);

  19055. SQLITE_PRIVATE void sqlite3GenerateConstraintChecks(Parse*,Table*,int*,int,int,int,int,

  19056.                                      u8,u8,int,int*,int*,Upsert*);

  19057. #ifdef SQLITE_ENABLE_NULL_TRIM

  19058. SQLITE_PRIVATE   void sqlite3SetMakeRecordP5(Vdbe*,Table*);

  19059. #else

  19060. # define sqlite3SetMakeRecordP5(A,B)

  19061. #endif

  19062. SQLITE_PRIVATE void sqlite3CompleteInsertion(Parse*,Table*,int,int,int,int*,int,int,int);

  19063. SQLITE_PRIVATE int sqlite3OpenTableAndIndices(Parse*, Table*, int, u8, int, u8*, int*, int*);

  19064. SQLITE_PRIVATE void sqlite3BeginWriteOperation(Parse*, int, int);

  19065. SQLITE_PRIVATE void sqlite3MultiWrite(Parse*);

  19066. SQLITE_PRIVATE void sqlite3MayAbort(Parse*);

  19067. SQLITE_PRIVATE void sqlite3HaltConstraint(Parse*, int, int, char*, i8, u8);

  19068. SQLITE_PRIVATE void sqlite3UniqueConstraint(Parse*, int, Index*);

  19069. SQLITE_PRIVATE void sqlite3RowidConstraint(Parse*, int, Table*);

  19070. SQLITE_PRIVATE Expr *sqlite3ExprDup(sqlite3*,Expr*,int);

  19071. SQLITE_PRIVATE ExprList *sqlite3ExprListDup(sqlite3*,ExprList*,int);

  19072. SQLITE_PRIVATE SrcList *sqlite3SrcListDup(sqlite3*,SrcList*,int);

  19073. SQLITE_PRIVATE IdList *sqlite3IdListDup(sqlite3*,IdList*);

  19074. SQLITE_PRIVATE Select *sqlite3SelectDup(sqlite3*,Select*,int);

  19075. SQLITE_PRIVATE FuncDef *sqlite3FunctionSearch(int,const char*);

  19076. SQLITE_PRIVATE void sqlite3InsertBuiltinFuncs(FuncDef*,int);

  19077. SQLITE_PRIVATE FuncDef *sqlite3FindFunction(sqlite3*,const char*,int,u8,u8);

  19078. SQLITE_PRIVATE void sqlite3RegisterBuiltinFunctions(void);

  19079. SQLITE_PRIVATE void sqlite3RegisterDateTimeFunctions(void);

  19080. SQLITE_PRIVATE void sqlite3RegisterPerConnectionBuiltinFunctions(sqlite3*);

  19081. SQLITE_PRIVATE int sqlite3SafetyCheckOk(sqlite3*);

  19082. SQLITE_PRIVATE int sqlite3SafetyCheckSickOrOk(sqlite3*);

  19083. SQLITE_PRIVATE void sqlite3ChangeCookie(Parse*, int);

  19084. 

  19085. #if !defined(SQLITE_OMIT_VIEW) && !defined(SQLITE_OMIT_TRIGGER)

  19086. SQLITE_PRIVATE void sqlite3MaterializeView(Parse*, Table*, Expr*, ExprList*,Expr*,int);

  19087. #endif

  19088. 

  19089. #ifndef SQLITE_OMIT_TRIGGER

  19090. SQLITE_PRIVATE   void sqlite3BeginTrigger(Parse*, Token*,Token*,int,int,IdList*,SrcList*,

  19091.                            Expr*,int, int);

  19092. SQLITE_PRIVATE   void sqlite3FinishTrigger(Parse*, TriggerStep*, Token*);

  19093. SQLITE_PRIVATE   void sqlite3DropTrigger(Parse*, SrcList*, int);

  19094. SQLITE_PRIVATE   void sqlite3DropTriggerPtr(Parse*, Trigger*);

  19095. SQLITE_PRIVATE   Trigger *sqlite3TriggersExist(Parse *, Table*, int, ExprList*, int *pMask);

  19096. SQLITE_PRIVATE   Trigger *sqlite3TriggerList(Parse *, Table *);

  19097. SQLITE_PRIVATE   void sqlite3CodeRowTrigger(Parse*, Trigger *, int, ExprList*, int, Table *,

  19098.                             int, int, int);

  19099. SQLITE_PRIVATE   void sqlite3CodeRowTriggerDirect(Parse *, Trigger *, Table *, int, int, int);

  19100.   void sqliteViewTriggers(Parse*, Table*, Expr*, int, ExprList*);

  19101. SQLITE_PRIVATE   void sqlite3DeleteTriggerStep(sqlite3*, TriggerStep*);

  19102. SQLITE_PRIVATE   TriggerStep *sqlite3TriggerSelectStep(sqlite3*,Select*,

  19103.                                         const char*,const char*);

  19104. SQLITE_PRIVATE   TriggerStep *sqlite3TriggerInsertStep(Parse*,Token*, IdList*,

  19105.                                         Select*,u8,Upsert*,

  19106.                                         const char*,const char*);

  19107. SQLITE_PRIVATE   TriggerStep *sqlite3TriggerUpdateStep(Parse*,Token*,ExprList*, Expr*, u8,

  19108.                                         const char*,const char*);

  19109. SQLITE_PRIVATE   TriggerStep *sqlite3TriggerDeleteStep(Parse*,Token*, Expr*,

  19110.                                         const char*,const char*);

  19111. SQLITE_PRIVATE   void sqlite3DeleteTrigger(sqlite3*, Trigger*);

  19112. SQLITE_PRIVATE   void sqlite3UnlinkAndDeleteTrigger(sqlite3*,int,const char*);

  19113. SQLITE_PRIVATE   u32 sqlite3TriggerColmask(Parse*,Trigger*,ExprList*,int,int,Table*,int);

  19114. # define sqlite3ParseToplevel(p) ((p)->pToplevel ? (p)->pToplevel : (p))

  19115. # define sqlite3IsToplevel(p) ((p)->pToplevel==0)

  19116. #else

  19117. # define sqlite3TriggersExist(B,C,D,E,F) 0

  19118. # define sqlite3DeleteTrigger(A,B)

  19119. # define sqlite3DropTriggerPtr(A,B)

  19120. # define sqlite3UnlinkAndDeleteTrigger(A,B,C)

  19121. # define sqlite3CodeRowTrigger(A,B,C,D,E,F,G,H,I)

  19122. # define sqlite3CodeRowTriggerDirect(A,B,C,D,E,F)

  19123. # define sqlite3TriggerList(X, Y) 0

  19124. # define sqlite3ParseToplevel(p) p

  19125. # define sqlite3IsToplevel(p) 1

  19126. # define sqlite3TriggerColmask(A,B,C,D,E,F,G) 0

  19127. #endif

  19128. 

  19129. SQLITE_PRIVATE int sqlite3JoinType(Parse*, Token*, Token*, Token*);

  19130. SQLITE_PRIVATE void sqlite3CreateForeignKey(Parse*, ExprList*, Token*, ExprList*, int);

  19131. SQLITE_PRIVATE void sqlite3DeferForeignKey(Parse*, int);

  19132. #ifndef SQLITE_OMIT_AUTHORIZATION

  19133. SQLITE_PRIVATE   void sqlite3AuthRead(Parse*,Expr*,Schema*,SrcList*);

  19134. SQLITE_PRIVATE   int sqlite3AuthCheck(Parse*,int, const char*, const char*, const char*);

  19135. SQLITE_PRIVATE   void sqlite3AuthContextPush(Parse*, AuthContext*, const char*);

  19136. SQLITE_PRIVATE   void sqlite3AuthContextPop(AuthContext*);

  19137. SQLITE_PRIVATE   int sqlite3AuthReadCol(Parse*, const char *, const char *, int);

  19138. #else

  19139. # define sqlite3AuthRead(a,b,c,d)

  19140. # define sqlite3AuthCheck(a,b,c,d,e)    SQLITE_OK

  19141. # define sqlite3AuthContextPush(a,b,c)

  19142. # define sqlite3AuthContextPop(a)  ((void)(a))

  19143. #endif

  19144. SQLITE_PRIVATE void sqlite3Attach(Parse*, Expr*, Expr*, Expr*);

  19145. SQLITE_PRIVATE void sqlite3Detach(Parse*, Expr*);

  19146. SQLITE_PRIVATE void sqlite3FixInit(DbFixer*, Parse*, int, const char*, const Token*);

  19147. SQLITE_PRIVATE int sqlite3FixSrcList(DbFixer*, SrcList*);

  19148. SQLITE_PRIVATE int sqlite3FixSelect(DbFixer*, Select*);

  19149. SQLITE_PRIVATE int sqlite3FixExpr(DbFixer*, Expr*);

  19150. SQLITE_PRIVATE int sqlite3FixExprList(DbFixer*, ExprList*);

  19151. SQLITE_PRIVATE int sqlite3FixTriggerStep(DbFixer*, TriggerStep*);

  19152. SQLITE_PRIVATE int sqlite3RealSameAsInt(double,sqlite3_int64);

  19153. SQLITE_PRIVATE int sqlite3AtoF(const char *z, double*, int, u8);

  19154. SQLITE_PRIVATE int sqlite3GetInt32(const char *, int*);

  19155. SQLITE_PRIVATE int sqlite3Atoi(const char*);

  19156. #ifndef SQLITE_OMIT_UTF16

  19157. SQLITE_PRIVATE int sqlite3Utf16ByteLen(const void *pData, int nChar);

  19158. #endif

  19159. SQLITE_PRIVATE int sqlite3Utf8CharLen(const char *pData, int nByte);

  19160. SQLITE_PRIVATE u32 sqlite3Utf8Read(const u8**);

  19161. SQLITE_PRIVATE LogEst sqlite3LogEst(u64);

  19162. SQLITE_PRIVATE LogEst sqlite3LogEstAdd(LogEst,LogEst);

  19163. #ifndef SQLITE_OMIT_VIRTUALTABLE

  19164. SQLITE_PRIVATE LogEst sqlite3LogEstFromDouble(double);

  19165. #endif

  19166. #if defined(SQLITE_ENABLE_STMT_SCANSTATUS) || \

  19167.     defined(SQLITE_ENABLE_STAT3_OR_STAT4) || \

  19168.     defined(SQLITE_EXPLAIN_ESTIMATED_ROWS)

  19169. SQLITE_PRIVATE u64 sqlite3LogEstToInt(LogEst);

  19170. #endif

  19171. SQLITE_PRIVATE VList *sqlite3VListAdd(sqlite3*,VList*,const char*,int,int);

  19172. SQLITE_PRIVATE const char *sqlite3VListNumToName(VList*,int);

  19173. SQLITE_PRIVATE int sqlite3VListNameToNum(VList*,const char*,int);

  19174. 

  19175. /*

  19176. ** Routines to read and write variable-length integers.  These used to

  19177. ** be defined locally, but now we use the varint routines in the util.c

  19178. ** file.

  19179. */

  19180. SQLITE_PRIVATE int sqlite3PutVarint(unsigned char*, u64);

  19181. SQLITE_PRIVATE u8 sqlite3GetVarint(const unsigned char *, u64 *);

  19182. SQLITE_PRIVATE u8 sqlite3GetVarint32(const unsigned char *, u32 *);

  19183. SQLITE_PRIVATE int sqlite3VarintLen(u64 v);

  19184. 

  19185. /*

  19186. ** The common case is for a varint to be a single byte.  They following

  19187. ** macros handle the common case without a procedure call, but then call

  19188. ** the procedure for larger varints.

  19189. */

  19190. #define getVarint32(A,B)  \

  19191.   (u8)((*(A)<(u8)0x80)?((B)=(u32)*(A)),1:sqlite3GetVarint32((A),(u32 *)&(B)))

  19192. #define putVarint32(A,B)  \

  19193.   (u8)(((u32)(B)<(u32)0x80)?(*(A)=(unsigned char)(B)),1:\

  19194.   sqlite3PutVarint((A),(B)))

  19195. #define getVarint    sqlite3GetVarint

  19196. #define putVarint    sqlite3PutVarint

  19197. 

  19198. 

  19199. SQLITE_PRIVATE const char *sqlite3IndexAffinityStr(sqlite3*, Index*);

  19200. SQLITE_PRIVATE void sqlite3TableAffinity(Vdbe*, Table*, int);

  19201. SQLITE_PRIVATE char sqlite3CompareAffinity(Expr *pExpr, char aff2);

  19202. SQLITE_PRIVATE int sqlite3IndexAffinityOk(Expr *pExpr, char idx_affinity);

  19203. SQLITE_PRIVATE char sqlite3TableColumnAffinity(Table*,int);

  19204. SQLITE_PRIVATE char sqlite3ExprAffinity(Expr *pExpr);

  19205. SQLITE_PRIVATE int sqlite3Atoi64(const char*, i64*, int, u8);

  19206. SQLITE_PRIVATE int sqlite3DecOrHexToI64(const char*, i64*);

  19207. SQLITE_PRIVATE void sqlite3ErrorWithMsg(sqlite3*, int, const char*,...);

  19208. SQLITE_PRIVATE void sqlite3Error(sqlite3*,int);

  19209. SQLITE_PRIVATE void sqlite3SystemError(sqlite3*,int);

  19210. SQLITE_PRIVATE void *sqlite3HexToBlob(sqlite3*, const char *z, int n);

  19211. SQLITE_PRIVATE u8 sqlite3HexToInt(int h);

  19212. SQLITE_PRIVATE int sqlite3TwoPartName(Parse *, Token *, Token *, Token **);

  19213. 

  19214. #if defined(SQLITE_NEED_ERR_NAME)

  19215. SQLITE_PRIVATE const char *sqlite3ErrName(int);

  19216. #endif

  19217. 

  19218. #ifdef SQLITE_ENABLE_DESERIALIZE

  19219. SQLITE_PRIVATE int sqlite3MemdbInit(void);

  19220. #endif

  19221. 

  19222. SQLITE_PRIVATE const char *sqlite3ErrStr(int);

  19223. SQLITE_PRIVATE int sqlite3ReadSchema(Parse *pParse);

  19224. SQLITE_PRIVATE CollSeq *sqlite3FindCollSeq(sqlite3*,u8 enc, const char*,int);

  19225. SQLITE_PRIVATE int sqlite3IsBinary(const CollSeq*);

  19226. SQLITE_PRIVATE CollSeq *sqlite3LocateCollSeq(Parse *pParse, const char*zName);

  19227. SQLITE_PRIVATE CollSeq *sqlite3ExprCollSeq(Parse *pParse, Expr *pExpr);

  19228. SQLITE_PRIVATE CollSeq *sqlite3ExprNNCollSeq(Parse *pParse, Expr *pExpr);

  19229. SQLITE_PRIVATE int sqlite3ExprCollSeqMatch(Parse*,Expr*,Expr*);

  19230. SQLITE_PRIVATE Expr *sqlite3ExprAddCollateToken(Parse *pParse, Expr*, const Token*, int);

  19231. SQLITE_PRIVATE Expr *sqlite3ExprAddCollateString(Parse*,Expr*,const char*);

  19232. SQLITE_PRIVATE Expr *sqlite3ExprSkipCollate(Expr*);

  19233. SQLITE_PRIVATE int sqlite3CheckCollSeq(Parse *, CollSeq *);

  19234. SQLITE_PRIVATE int sqlite3WritableSchema(sqlite3*);

  19235. SQLITE_PRIVATE int sqlite3CheckObjectName(Parse *, const char *);

  19236. SQLITE_PRIVATE void sqlite3VdbeSetChanges(sqlite3 *, int);

  19237. SQLITE_PRIVATE int sqlite3AddInt64(i64*,i64);

  19238. SQLITE_PRIVATE int sqlite3SubInt64(i64*,i64);

  19239. SQLITE_PRIVATE int sqlite3MulInt64(i64*,i64);

  19240. SQLITE_PRIVATE int sqlite3AbsInt32(int);

  19241. #ifdef SQLITE_ENABLE_8_3_NAMES

  19242. SQLITE_PRIVATE void sqlite3FileSuffix3(const char*, char*);

  19243. #else

  19244. # define sqlite3FileSuffix3(X,Y)

  19245. #endif

  19246. SQLITE_PRIVATE u8 sqlite3GetBoolean(const char *z,u8);

  19247. 

  19248. SQLITE_PRIVATE const void *sqlite3ValueText(sqlite3_value*, u8);

  19249. SQLITE_PRIVATE int sqlite3ValueBytes(sqlite3_value*, u8);

  19250. SQLITE_PRIVATE void sqlite3ValueSetStr(sqlite3_value*, int, const void *,u8,

  19251.                         void(*)(void*));

  19252. SQLITE_PRIVATE void sqlite3ValueSetNull(sqlite3_value*);

  19253. SQLITE_PRIVATE void sqlite3ValueFree(sqlite3_value*);

  19254. #ifndef SQLITE_UNTESTABLE

  19255. SQLITE_PRIVATE void sqlite3ResultIntReal(sqlite3_context*);

  19256. #endif

  19257. SQLITE_PRIVATE sqlite3_value *sqlite3ValueNew(sqlite3 *);

  19258. #ifndef SQLITE_OMIT_UTF16

  19259. SQLITE_PRIVATE char *sqlite3Utf16to8(sqlite3 *, const void*, int, u8);

  19260. #endif

  19261. SQLITE_PRIVATE int sqlite3ValueFromExpr(sqlite3 *, Expr *, u8, u8, sqlite3_value **);

  19262. SQLITE_PRIVATE void sqlite3ValueApplyAffinity(sqlite3_value *, u8, u8);

  19263. #ifndef SQLITE_AMALGAMATION

  19264. SQLITE_PRIVATE const unsigned char sqlite3OpcodeProperty[];

  19265. SQLITE_PRIVATE const char sqlite3StrBINARY[];

  19266. SQLITE_PRIVATE const unsigned char sqlite3UpperToLower[];

  19267. SQLITE_PRIVATE const unsigned char sqlite3CtypeMap[];

  19268. SQLITE_PRIVATE const Token sqlite3IntTokens[];

  19269. SQLITE_PRIVATE SQLITE_WSD struct Sqlite3Config sqlite3Config;

  19270. SQLITE_PRIVATE FuncDefHash sqlite3BuiltinFunctions;

  19271. #ifndef SQLITE_OMIT_WSD

  19272. SQLITE_PRIVATE int sqlite3PendingByte;

  19273. #endif

  19274. #endif

  19275. #ifdef VDBE_PROFILE

  19276. SQLITE_PRIVATE sqlite3_uint64 sqlite3NProfileCnt;

  19277. #endif

  19278. SQLITE_PRIVATE void sqlite3RootPageMoved(sqlite3*, int, int, int);

  19279. SQLITE_PRIVATE void sqlite3Reindex(Parse*, Token*, Token*);

  19280. SQLITE_PRIVATE void sqlite3AlterFunctions(void);

  19281. SQLITE_PRIVATE void sqlite3AlterRenameTable(Parse*, SrcList*, Token*);

  19282. SQLITE_PRIVATE void sqlite3AlterRenameColumn(Parse*, SrcList*, Token*, Token*);

  19283. SQLITE_PRIVATE int sqlite3GetToken(const unsigned char *, int *);

  19284. SQLITE_PRIVATE void sqlite3NestedParse(Parse*, const char*, ...);

  19285. SQLITE_PRIVATE void sqlite3ExpirePreparedStatements(sqlite3*, int);

  19286. SQLITE_PRIVATE void sqlite3CodeRhsOfIN(Parse*, Expr*, int);

  19287. SQLITE_PRIVATE int sqlite3CodeSubselect(Parse*, Expr*);

  19288. SQLITE_PRIVATE void sqlite3SelectPrep(Parse*, Select*, NameContext*);

  19289. SQLITE_PRIVATE void sqlite3SelectWrongNumTermsError(Parse *pParse, Select *p);

  19290. SQLITE_PRIVATE int sqlite3MatchSpanName(const char*, const char*, const char*, const char*);

  19291. SQLITE_PRIVATE int sqlite3ResolveExprNames(NameContext*, Expr*);

  19292. SQLITE_PRIVATE int sqlite3ResolveExprListNames(NameContext*, ExprList*);

  19293. SQLITE_PRIVATE void sqlite3ResolveSelectNames(Parse*, Select*, NameContext*);

  19294. SQLITE_PRIVATE int sqlite3ResolveSelfReference(Parse*,Table*,int,Expr*,ExprList*);

  19295. SQLITE_PRIVATE int sqlite3ResolveOrderGroupBy(Parse*, Select*, ExprList*, const char*);

  19296. SQLITE_PRIVATE void sqlite3ColumnDefault(Vdbe *, Table *, int, int);

  19297. SQLITE_PRIVATE void sqlite3AlterFinishAddColumn(Parse *, Token *);

  19298. SQLITE_PRIVATE void sqlite3AlterBeginAddColumn(Parse *, SrcList *);

  19299. SQLITE_PRIVATE void *sqlite3RenameTokenMap(Parse*, void*, Token*);

  19300. SQLITE_PRIVATE void sqlite3RenameTokenRemap(Parse*, void *pTo, void *pFrom);

  19301. SQLITE_PRIVATE void sqlite3RenameExprUnmap(Parse*, Expr*);

  19302. SQLITE_PRIVATE void sqlite3RenameExprlistUnmap(Parse*, ExprList*);

  19303. SQLITE_PRIVATE CollSeq *sqlite3GetCollSeq(Parse*, u8, CollSeq *, const char*);

  19304. SQLITE_PRIVATE char sqlite3AffinityType(const char*, Column*);

  19305. SQLITE_PRIVATE void sqlite3Analyze(Parse*, Token*, Token*);

  19306. SQLITE_PRIVATE int sqlite3InvokeBusyHandler(BusyHandler*, sqlite3_file*);

  19307. SQLITE_PRIVATE int sqlite3FindDb(sqlite3*, Token*);

  19308. SQLITE_PRIVATE int sqlite3FindDbName(sqlite3 *, const char *);

  19309. SQLITE_PRIVATE int sqlite3AnalysisLoad(sqlite3*,int iDB);

  19310. SQLITE_PRIVATE void sqlite3DeleteIndexSamples(sqlite3*,Index*);

  19311. SQLITE_PRIVATE void sqlite3DefaultRowEst(Index*);

  19312. SQLITE_PRIVATE void sqlite3RegisterLikeFunctions(sqlite3*, int);

  19313. SQLITE_PRIVATE int sqlite3IsLikeFunction(sqlite3*,Expr*,int*,char*);

  19314. SQLITE_PRIVATE void sqlite3SchemaClear(void *);

  19315. SQLITE_PRIVATE Schema *sqlite3SchemaGet(sqlite3 *, Btree *);

  19316. SQLITE_PRIVATE int sqlite3SchemaToIndex(sqlite3 *db, Schema *);

  19317. SQLITE_PRIVATE KeyInfo *sqlite3KeyInfoAlloc(sqlite3*,int,int);

  19318. SQLITE_PRIVATE void sqlite3KeyInfoUnref(KeyInfo*);

  19319. SQLITE_PRIVATE KeyInfo *sqlite3KeyInfoRef(KeyInfo*);

  19320. SQLITE_PRIVATE KeyInfo *sqlite3KeyInfoOfIndex(Parse*, Index*);

  19321. SQLITE_PRIVATE KeyInfo *sqlite3KeyInfoFromExprList(Parse*, ExprList*, int, int);

  19322. 

  19323. #ifdef SQLITE_DEBUG

  19324. SQLITE_PRIVATE int sqlite3KeyInfoIsWriteable(KeyInfo*);

  19325. #endif

  19326. SQLITE_PRIVATE int sqlite3CreateFunc(sqlite3 *, const char *, int, int, void *,

  19327.   void (*)(sqlite3_context*,int,sqlite3_value **),

  19328.   void (*)(sqlite3_context*,int,sqlite3_value **), 

  19329.   void (*)(sqlite3_context*),

  19330.   void (*)(sqlite3_context*),

  19331.   void (*)(sqlite3_context*,int,sqlite3_value **), 

  19332.   FuncDestructor *pDestructor

  19333. );

  19334. SQLITE_PRIVATE void sqlite3NoopDestructor(void*);

  19335. SQLITE_PRIVATE void sqlite3OomFault(sqlite3*);

  19336. SQLITE_PRIVATE void sqlite3OomClear(sqlite3*);

  19337. SQLITE_PRIVATE int sqlite3ApiExit(sqlite3 *db, int);

  19338. SQLITE_PRIVATE int sqlite3OpenTempDatabase(Parse *);

  19339. 

  19340. SQLITE_PRIVATE void sqlite3StrAccumInit(StrAccum*, sqlite3*, char*, int, int);

  19341. SQLITE_PRIVATE char *sqlite3StrAccumFinish(StrAccum*);

  19342. SQLITE_PRIVATE void sqlite3SelectDestInit(SelectDest*,int,int);

  19343. SQLITE_PRIVATE Expr *sqlite3CreateColumnExpr(sqlite3 *, SrcList *, int, int);

  19344. 

  19345. SQLITE_PRIVATE void sqlite3BackupRestart(sqlite3_backup *);

  19346. SQLITE_PRIVATE void sqlite3BackupUpdate(sqlite3_backup *, Pgno, const u8 *);

  19347. 

  19348. #ifndef SQLITE_OMIT_SUBQUERY

  19349. SQLITE_PRIVATE int sqlite3ExprCheckIN(Parse*, Expr*);

  19350. #else

  19351. # define sqlite3ExprCheckIN(x,y) SQLITE_OK

  19352. #endif

  19353. 

  19354. #ifdef SQLITE_ENABLE_STAT3_OR_STAT4

  19355. SQLITE_PRIVATE void sqlite3AnalyzeFunctions(void);

  19356. SQLITE_PRIVATE int sqlite3Stat4ProbeSetValue(

  19357.     Parse*,Index*,UnpackedRecord**,Expr*,int,int,int*);

  19358. SQLITE_PRIVATE int sqlite3Stat4ValueFromExpr(Parse*, Expr*, u8, sqlite3_value**);

  19359. SQLITE_PRIVATE void sqlite3Stat4ProbeFree(UnpackedRecord*);

  19360. SQLITE_PRIVATE int sqlite3Stat4Column(sqlite3*, const void*, int, int, sqlite3_value**);

  19361. SQLITE_PRIVATE char sqlite3IndexColumnAffinity(sqlite3*, Index*, int);

  19362. #endif

  19363. 

  19364. /*

  19365. ** The interface to the LEMON-generated parser

  19366. */

  19367. #ifndef SQLITE_AMALGAMATION

  19368. SQLITE_PRIVATE   void *sqlite3ParserAlloc(void*(*)(u64), Parse*);

  19369. SQLITE_PRIVATE   void sqlite3ParserFree(void*, void(*)(void*));

  19370. #endif

  19371. SQLITE_PRIVATE void sqlite3Parser(void*, int, Token);

  19372. SQLITE_PRIVATE int sqlite3ParserFallback(int);

  19373. #ifdef YYTRACKMAXSTACKDEPTH

  19374. SQLITE_PRIVATE   int sqlite3ParserStackPeak(void*);

  19375. #endif

  19376. 

  19377. SQLITE_PRIVATE void sqlite3AutoLoadExtensions(sqlite3*);

  19378. #ifndef SQLITE_OMIT_LOAD_EXTENSION

  19379. SQLITE_PRIVATE   void sqlite3CloseExtensions(sqlite3*);

  19380. #else

  19381. # define sqlite3CloseExtensions(X)

  19382. #endif

  19383. 

  19384. #ifndef SQLITE_OMIT_SHARED_CACHE

  19385. SQLITE_PRIVATE   void sqlite3TableLock(Parse *, int, int, u8, const char *);

  19386. #else

  19387.   #define sqlite3TableLock(v,w,x,y,z)

  19388. #endif

  19389. 

  19390. #ifdef SQLITE_TEST

  19391. SQLITE_PRIVATE   int sqlite3Utf8To8(unsigned char*);

  19392. #endif

  19393. 

  19394. #ifdef SQLITE_OMIT_VIRTUALTABLE

  19395. #  define sqlite3VtabClear(Y)

  19396. #  define sqlite3VtabSync(X,Y) SQLITE_OK

  19397. #  define sqlite3VtabRollback(X)

  19398. #  define sqlite3VtabCommit(X)

  19399. #  define sqlite3VtabInSync(db) 0

  19400. #  define sqlite3VtabLock(X)

  19401. #  define sqlite3VtabUnlock(X)

  19402. #  define sqlite3VtabUnlockList(X)

  19403. #  define sqlite3VtabSavepoint(X, Y, Z) SQLITE_OK

  19404. #  define sqlite3GetVTable(X,Y)  ((VTable*)0)

  19405. #else

  19406. SQLITE_PRIVATE    void sqlite3VtabClear(sqlite3 *db, Table*);

  19407. SQLITE_PRIVATE    void sqlite3VtabDisconnect(sqlite3 *db, Table *p);

  19408. SQLITE_PRIVATE    int sqlite3VtabSync(sqlite3 *db, Vdbe*);

  19409. SQLITE_PRIVATE    int sqlite3VtabRollback(sqlite3 *db);

  19410. SQLITE_PRIVATE    int sqlite3VtabCommit(sqlite3 *db);

  19411. SQLITE_PRIVATE    void sqlite3VtabLock(VTable *);

  19412. SQLITE_PRIVATE    void sqlite3VtabUnlock(VTable *);

  19413. SQLITE_PRIVATE    void sqlite3VtabUnlockList(sqlite3*);

  19414. SQLITE_PRIVATE    int sqlite3VtabSavepoint(sqlite3 *, int, int);

  19415. SQLITE_PRIVATE    void sqlite3VtabImportErrmsg(Vdbe*, sqlite3_vtab*);

  19416. SQLITE_PRIVATE    VTable *sqlite3GetVTable(sqlite3*, Table*);

  19417. SQLITE_PRIVATE    Module *sqlite3VtabCreateModule(

  19418.      sqlite3*,

  19419.      const char*,

  19420.      const sqlite3_module*,

  19421.      void*,

  19422.      void(*)(void*)

  19423.    );

  19424. #  define sqlite3VtabInSync(db) ((db)->nVTrans>0 && (db)->aVTrans==0)

  19425. #endif

  19426. SQLITE_PRIVATE int sqlite3VtabEponymousTableInit(Parse*,Module*);

  19427. SQLITE_PRIVATE void sqlite3VtabEponymousTableClear(sqlite3*,Module*);

  19428. SQLITE_PRIVATE void sqlite3VtabMakeWritable(Parse*,Table*);

  19429. SQLITE_PRIVATE void sqlite3VtabBeginParse(Parse*, Token*, Token*, Token*, int);

  19430. SQLITE_PRIVATE void sqlite3VtabFinishParse(Parse*, Token*);

  19431. SQLITE_PRIVATE void sqlite3VtabArgInit(Parse*);

  19432. SQLITE_PRIVATE void sqlite3VtabArgExtend(Parse*, Token*);

  19433. SQLITE_PRIVATE int sqlite3VtabCallCreate(sqlite3*, int, const char *, char **);

  19434. SQLITE_PRIVATE int sqlite3VtabCallConnect(Parse*, Table*);

  19435. SQLITE_PRIVATE int sqlite3VtabCallDestroy(sqlite3*, int, const char *);

  19436. SQLITE_PRIVATE int sqlite3VtabBegin(sqlite3 *, VTable *);

  19437. SQLITE_PRIVATE FuncDef *sqlite3VtabOverloadFunction(sqlite3 *,FuncDef*, int nArg, Expr*);

  19438. SQLITE_PRIVATE sqlite3_int64 sqlite3StmtCurrentTime(sqlite3_context*);

  19439. SQLITE_PRIVATE int sqlite3VdbeParameterIndex(Vdbe*, const char*, int);

  19440. SQLITE_PRIVATE int sqlite3TransferBindings(sqlite3_stmt *, sqlite3_stmt *);

  19441. SQLITE_PRIVATE void sqlite3ParserReset(Parse*);

  19442. #ifdef SQLITE_ENABLE_NORMALIZE

  19443. SQLITE_PRIVATE char *sqlite3Normalize(Vdbe*, const char*);

  19444. #endif

  19445. SQLITE_PRIVATE int sqlite3Reprepare(Vdbe*);

  19446. SQLITE_PRIVATE void sqlite3ExprListCheckLength(Parse*, ExprList*, const char*);

  19447. SQLITE_PRIVATE CollSeq *sqlite3BinaryCompareCollSeq(Parse *, Expr *, Expr *);

  19448. SQLITE_PRIVATE int sqlite3TempInMemory(const sqlite3*);

  19449. SQLITE_PRIVATE const char *sqlite3JournalModename(int);

  19450. #ifndef SQLITE_OMIT_WAL

  19451. SQLITE_PRIVATE   int sqlite3Checkpoint(sqlite3*, int, int, int*, int*);

  19452. SQLITE_PRIVATE   int sqlite3WalDefaultHook(void*,sqlite3*,const char*,int);

  19453. #endif

  19454. #ifndef SQLITE_OMIT_CTE

  19455. SQLITE_PRIVATE   With *sqlite3WithAdd(Parse*,With*,Token*,ExprList*,Select*);

  19456. SQLITE_PRIVATE   void sqlite3WithDelete(sqlite3*,With*);

  19457. SQLITE_PRIVATE   void sqlite3WithPush(Parse*, With*, u8);

  19458. #else

  19459. #define sqlite3WithPush(x,y,z)

  19460. #define sqlite3WithDelete(x,y)

  19461. #endif

  19462. #ifndef SQLITE_OMIT_UPSERT

  19463. SQLITE_PRIVATE   Upsert *sqlite3UpsertNew(sqlite3*,ExprList*,Expr*,ExprList*,Expr*);

  19464. SQLITE_PRIVATE   void sqlite3UpsertDelete(sqlite3*,Upsert*);

  19465. SQLITE_PRIVATE   Upsert *sqlite3UpsertDup(sqlite3*,Upsert*);

  19466. SQLITE_PRIVATE   int sqlite3UpsertAnalyzeTarget(Parse*,SrcList*,Upsert*);

  19467. SQLITE_PRIVATE   void sqlite3UpsertDoUpdate(Parse*,Upsert*,Table*,Index*,int);

  19468. #else

  19469. #define sqlite3UpsertNew(v,w,x,y,z) ((Upsert*)0)

  19470. #define sqlite3UpsertDelete(x,y)

  19471. #define sqlite3UpsertDup(x,y)       ((Upsert*)0)

  19472. #endif

  19473. 

  19474. 

  19475. /* Declarations for functions in fkey.c. All of these are replaced by

  19476. ** no-op macros if OMIT_FOREIGN_KEY is defined. In this case no foreign

  19477. ** key functionality is available. If OMIT_TRIGGER is defined but

  19478. ** OMIT_FOREIGN_KEY is not, only some of the functions are no-oped. In

  19479. ** this case foreign keys are parsed, but no other functionality is

  19480. ** provided (enforcement of FK constraints requires the triggers sub-system).

  19481. */

  19482. #if !defined(SQLITE_OMIT_FOREIGN_KEY) && !defined(SQLITE_OMIT_TRIGGER)

  19483. SQLITE_PRIVATE   void sqlite3FkCheck(Parse*, Table*, int, int, int*, int);

  19484. SQLITE_PRIVATE   void sqlite3FkDropTable(Parse*, SrcList *, Table*);

  19485. SQLITE_PRIVATE   void sqlite3FkActions(Parse*, Table*, ExprList*, int, int*, int);

  19486. SQLITE_PRIVATE   int sqlite3FkRequired(Parse*, Table*, int*, int);

  19487. SQLITE_PRIVATE   u32 sqlite3FkOldmask(Parse*, Table*);

  19488. SQLITE_PRIVATE   FKey *sqlite3FkReferences(Table *);

  19489. #else

  19490.   #define sqlite3FkActions(a,b,c,d,e,f)

  19491.   #define sqlite3FkCheck(a,b,c,d,e,f)

  19492.   #define sqlite3FkDropTable(a,b,c)

  19493.   #define sqlite3FkOldmask(a,b)         0

  19494.   #define sqlite3FkRequired(a,b,c,d)    0

  19495.   #define sqlite3FkReferences(a)        0

  19496. #endif

  19497. #ifndef SQLITE_OMIT_FOREIGN_KEY

  19498. SQLITE_PRIVATE   void sqlite3FkDelete(sqlite3 *, Table*);

  19499. SQLITE_PRIVATE   int sqlite3FkLocateIndex(Parse*,Table*,FKey*,Index**,int**);

  19500. #else

  19501.   #define sqlite3FkDelete(a,b)

  19502.   #define sqlite3FkLocateIndex(a,b,c,d,e)

  19503. #endif

  19504. 

  19505. 

  19506. /*

  19507. ** Available fault injectors.  Should be numbered beginning with 0.

  19508. */

  19509. #define SQLITE_FAULTINJECTOR_MALLOC     0

  19510. #define SQLITE_FAULTINJECTOR_COUNT      1

  19511. 

  19512. /*

  19513. ** The interface to the code in fault.c used for identifying "benign"

  19514. ** malloc failures. This is only present if SQLITE_UNTESTABLE

  19515. ** is not defined.

  19516. */

  19517. #ifndef SQLITE_UNTESTABLE

  19518. SQLITE_PRIVATE   void sqlite3BeginBenignMalloc(void);

  19519. SQLITE_PRIVATE   void sqlite3EndBenignMalloc(void);

  19520. #else

  19521.   #define sqlite3BeginBenignMalloc()

  19522.   #define sqlite3EndBenignMalloc()

  19523. #endif

  19524. 

  19525. /*

  19526. ** Allowed return values from sqlite3FindInIndex()

  19527. */

  19528. #define IN_INDEX_ROWID        1   /* Search the rowid of the table */

  19529. #define IN_INDEX_EPH          2   /* Search an ephemeral b-tree */

  19530. #define IN_INDEX_INDEX_ASC    3   /* Existing index ASCENDING */

  19531. #define IN_INDEX_INDEX_DESC   4   /* Existing index DESCENDING */

  19532. #define IN_INDEX_NOOP         5   /* No table available. Use comparisons */

  19533. /*

  19534. ** Allowed flags for the 3rd parameter to sqlite3FindInIndex().

  19535. */

  19536. #define IN_INDEX_NOOP_OK     0x0001  /* OK to return IN_INDEX_NOOP */

  19537. #define IN_INDEX_MEMBERSHIP  0x0002  /* IN operator used for membership test */

  19538. #define IN_INDEX_LOOP        0x0004  /* IN operator used as a loop */

  19539. SQLITE_PRIVATE int sqlite3FindInIndex(Parse *, Expr *, u32, int*, int*, int*);

  19540. 

  19541. SQLITE_PRIVATE int sqlite3JournalOpen(sqlite3_vfs *, const char *, sqlite3_file *, int, int);

  19542. SQLITE_PRIVATE int sqlite3JournalSize(sqlite3_vfs *);

  19543. #if defined(SQLITE_ENABLE_ATOMIC_WRITE) \

  19544.  || defined(SQLITE_ENABLE_BATCH_ATOMIC_WRITE)

  19545. SQLITE_PRIVATE   int sqlite3JournalCreate(sqlite3_file *);

  19546. #endif

  19547. 

  19548. SQLITE_PRIVATE int sqlite3JournalIsInMemory(sqlite3_file *p);

  19549. SQLITE_PRIVATE void sqlite3MemJournalOpen(sqlite3_file *);

  19550. 

  19551. SQLITE_PRIVATE void sqlite3ExprSetHeightAndFlags(Parse *pParse, Expr *p);

  19552. #if SQLITE_MAX_EXPR_DEPTH>0

  19553. SQLITE_PRIVATE   int sqlite3SelectExprHeight(Select *);

  19554. SQLITE_PRIVATE   int sqlite3ExprCheckHeight(Parse*, int);

  19555. #else

  19556.   #define sqlite3SelectExprHeight(x) 0

  19557.   #define sqlite3ExprCheckHeight(x,y)

  19558. #endif

  19559. 

  19560. SQLITE_PRIVATE u32 sqlite3Get4byte(const u8*);

  19561. SQLITE_PRIVATE void sqlite3Put4byte(u8*, u32);

  19562. 

  19563. #ifdef SQLITE_ENABLE_UNLOCK_NOTIFY

  19564. SQLITE_PRIVATE   void sqlite3ConnectionBlocked(sqlite3 *, sqlite3 *);

  19565. SQLITE_PRIVATE   void sqlite3ConnectionUnlocked(sqlite3 *db);

  19566. SQLITE_PRIVATE   void sqlite3ConnectionClosed(sqlite3 *db);

  19567. #else

  19568.   #define sqlite3ConnectionBlocked(x,y)

  19569.   #define sqlite3ConnectionUnlocked(x)

  19570.   #define sqlite3ConnectionClosed(x)

  19571. #endif

  19572. 

  19573. #ifdef SQLITE_DEBUG

  19574. SQLITE_PRIVATE   void sqlite3ParserTrace(FILE*, char *);

  19575. #endif

  19576. #if defined(YYCOVERAGE)

  19577. SQLITE_PRIVATE   int sqlite3ParserCoverage(FILE*);

  19578. #endif

  19579. 

  19580. /*

  19581. ** If the SQLITE_ENABLE IOTRACE exists then the global variable

  19582. ** sqlite3IoTrace is a pointer to a printf-like routine used to

  19583. ** print I/O tracing messages.

  19584. */

  19585. #ifdef SQLITE_ENABLE_IOTRACE

  19586. # define IOTRACE(A)  if( sqlite3IoTrace ){ sqlite3IoTrace A; }

  19587. SQLITE_PRIVATE   void sqlite3VdbeIOTraceSql(Vdbe*);

  19588. SQLITE_API SQLITE_EXTERN void (SQLITE_CDECL *sqlite3IoTrace)(const char*,...);

  19589. #else

  19590. # define IOTRACE(A)

  19591. # define sqlite3VdbeIOTraceSql(X)

  19592. #endif

  19593. 

  19594. /*

  19595. ** These routines are available for the mem2.c debugging memory allocator

  19596. ** only.  They are used to verify that different "types" of memory

  19597. ** allocations are properly tracked by the system.

  19598. **

  19599. ** sqlite3MemdebugSetType() sets the "type" of an allocation to one of

  19600. ** the MEMTYPE_* macros defined below.  The type must be a bitmask with

  19601. ** a single bit set.

  19602. **

  19603. ** sqlite3MemdebugHasType() returns true if any of the bits in its second

  19604. ** argument match the type set by the previous sqlite3MemdebugSetType().

  19605. ** sqlite3MemdebugHasType() is intended for use inside assert() statements.

  19606. **

  19607. ** sqlite3MemdebugNoType() returns true if none of the bits in its second

  19608. ** argument match the type set by the previous sqlite3MemdebugSetType().

  19609. **

  19610. ** Perhaps the most important point is the difference between MEMTYPE_HEAP

  19611. ** and MEMTYPE_LOOKASIDE.  If an allocation is MEMTYPE_LOOKASIDE, that means

  19612. ** it might have been allocated by lookaside, except the allocation was

  19613. ** too large or lookaside was already full.  It is important to verify

  19614. ** that allocations that might have been satisfied by lookaside are not

  19615. ** passed back to non-lookaside free() routines.  Asserts such as the

  19616. ** example above are placed on the non-lookaside free() routines to verify

  19617. ** this constraint.

  19618. **

  19619. ** All of this is no-op for a production build.  It only comes into

  19620. ** play when the SQLITE_MEMDEBUG compile-time option is used.

  19621. */

  19622. #ifdef SQLITE_MEMDEBUG

  19623. SQLITE_PRIVATE   void sqlite3MemdebugSetType(void*,u8);

  19624. SQLITE_PRIVATE   int sqlite3MemdebugHasType(void*,u8);

  19625. SQLITE_PRIVATE   int sqlite3MemdebugNoType(void*,u8);

  19626. #else

  19627. # define sqlite3MemdebugSetType(X,Y)  /* no-op */

  19628. # define sqlite3MemdebugHasType(X,Y)  1

  19629. # define sqlite3MemdebugNoType(X,Y)   1

  19630. #endif

  19631. #define MEMTYPE_HEAP       0x01  /* General heap allocations */

  19632. #define MEMTYPE_LOOKASIDE  0x02  /* Heap that might have been lookaside */

  19633. #define MEMTYPE_PCACHE     0x04  /* Page cache allocations */

  19634. 

  19635. /*

  19636. ** Threading interface

  19637. */

  19638. #if SQLITE_MAX_WORKER_THREADS>0

  19639. SQLITE_PRIVATE int sqlite3ThreadCreate(SQLiteThread**,void*(*)(void*),void*);

  19640. SQLITE_PRIVATE int sqlite3ThreadJoin(SQLiteThread*, void**);

  19641. #endif

  19642. 

  19643. #if defined(SQLITE_ENABLE_DBPAGE_VTAB) || defined(SQLITE_TEST)

  19644. SQLITE_PRIVATE int sqlite3DbpageRegister(sqlite3*);

  19645. #endif

  19646. #if defined(SQLITE_ENABLE_DBSTAT_VTAB) || defined(SQLITE_TEST)

  19647. SQLITE_PRIVATE int sqlite3DbstatRegister(sqlite3*);

  19648. #endif

  19649. 

  19650. SQLITE_PRIVATE int sqlite3ExprVectorSize(Expr *pExpr);

  19651. SQLITE_PRIVATE int sqlite3ExprIsVector(Expr *pExpr);

  19652. SQLITE_PRIVATE Expr *sqlite3VectorFieldSubexpr(Expr*, int);

  19653. SQLITE_PRIVATE Expr *sqlite3ExprForVectorField(Parse*,Expr*,int);

  19654. SQLITE_PRIVATE void sqlite3VectorErrorMsg(Parse*, Expr*);

  19655. 

  19656. #ifndef SQLITE_OMIT_COMPILEOPTION_DIAGS

  19657. SQLITE_PRIVATE const char **sqlite3CompileOptions(int *pnOpt);

  19658. #endif

  19659. 

  19660. #endif /* SQLITEINT_H */

  19661. 

  19662. /************** End of sqliteInt.h *******************************************/

  19663. /************** Begin file global.c ******************************************/

  19664. /*

  19665. ** 2008 June 13

  19666. **

  19667. ** The author disclaims copyright to this source code.  In place of

  19668. ** a legal notice, here is a blessing:

  19669. **

  19670. **    May you do good and not evil.

  19671. **    May you find forgiveness for yourself and forgive others.

  19672. **    May you share freely, never taking more than you give.

  19673. **

  19674. *************************************************************************

  19675. **

  19676. ** This file contains definitions of global variables and constants.

  19677. */

  19678. /* #include "sqliteInt.h" */

  19679. 

  19680. /* An array to map all upper-case characters into their corresponding

  19681. ** lower-case character. 

  19682. **

  19683. ** SQLite only considers US-ASCII (or EBCDIC) characters.  We do not

  19684. ** handle case conversions for the UTF character set since the tables

  19685. ** involved are nearly as big or bigger than SQLite itself.

  19686. */

  19687. SQLITE_PRIVATE const unsigned char sqlite3UpperToLower[] = {

  19688. #ifdef SQLITE_ASCII

  19689.       0,  1,  2,  3,  4,  5,  6,  7,  8,  9, 10, 11, 12, 13, 14, 15, 16, 17,

  19690.      18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35,

  19691.      36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53,

  19692.      54, 55, 56, 57, 58, 59, 60, 61, 62, 63, 64, 97, 98, 99,100,101,102,103,

  19693.     104,105,106,107,108,109,110,111,112,113,114,115,116,117,118,119,120,121,

  19694.     122, 91, 92, 93, 94, 95, 96, 97, 98, 99,100,101,102,103,104,105,106,107,

  19695.     108,109,110,111,112,113,114,115,116,117,118,119,120,121,122,123,124,125,

  19696.     126,127,128,129,130,131,132,133,134,135,136,137,138,139,140,141,142,143,

  19697.     144,145,146,147,148,149,150,151,152,153,154,155,156,157,158,159,160,161,

  19698.     162,163,164,165,166,167,168,169,170,171,172,173,174,175,176,177,178,179,

  19699.     180,181,182,183,184,185,186,187,188,189,190,191,192,193,194,195,196,197,

  19700.     198,199,200,201,202,203,204,205,206,207,208,209,210,211,212,213,214,215,

  19701.     216,217,218,219,220,221,222,223,224,225,226,227,228,229,230,231,232,233,

  19702.     234,235,236,237,238,239,240,241,242,243,244,245,246,247,248,249,250,251,

  19703.     252,253,254,255

  19704. #endif

  19705. #ifdef SQLITE_EBCDIC

  19706.       0,  1,  2,  3,  4,  5,  6,  7,  8,  9, 10, 11, 12, 13, 14, 15, /* 0x */

  19707.      16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, /* 1x */

  19708.      32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, /* 2x */

  19709.      48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 62, 63, /* 3x */

  19710.      64, 65, 66, 67, 68, 69, 70, 71, 72, 73, 74, 75, 76, 77, 78, 79, /* 4x */

  19711.      80, 81, 82, 83, 84, 85, 86, 87, 88, 89, 90, 91, 92, 93, 94, 95, /* 5x */

  19712.      96, 97, 98, 99,100,101,102,103,104,105,106,107,108,109,110,111, /* 6x */

  19713.     112,113,114,115,116,117,118,119,120,121,122,123,124,125,126,127, /* 7x */

  19714.     128,129,130,131,132,133,134,135,136,137,138,139,140,141,142,143, /* 8x */

  19715.     144,145,146,147,148,149,150,151,152,153,154,155,156,157,158,159, /* 9x */

  19716.     160,161,162,163,164,165,166,167,168,169,170,171,140,141,142,175, /* Ax */

  19717.     176,177,178,179,180,181,182,183,184,185,186,187,188,189,190,191, /* Bx */

  19718.     192,129,130,131,132,133,134,135,136,137,202,203,204,205,206,207, /* Cx */

  19719.     208,145,146,147,148,149,150,151,152,153,218,219,220,221,222,223, /* Dx */

  19720.     224,225,162,163,164,165,166,167,168,169,234,235,236,237,238,239, /* Ex */

  19721.     240,241,242,243,244,245,246,247,248,249,250,251,252,253,254,255, /* Fx */

  19722. #endif

  19723. };

  19724. 

  19725. /*

  19726. ** The following 256 byte lookup table is used to support SQLites built-in

  19727. ** equivalents to the following standard library functions:

  19728. **

  19729. **   isspace()                        0x01

  19730. **   isalpha()                        0x02

  19731. **   isdigit()                        0x04

  19732. **   isalnum()                        0x06

  19733. **   isxdigit()                       0x08

  19734. **   toupper()                        0x20

  19735. **   SQLite identifier character      0x40

  19736. **   Quote character                  0x80

  19737. **

  19738. ** Bit 0x20 is set if the mapped character requires translation to upper

  19739. ** case. i.e. if the character is a lower-case ASCII character.

  19740. ** If x is a lower-case ASCII character, then its upper-case equivalent

  19741. ** is (x - 0x20). Therefore toupper() can be implemented as:

  19742. **

  19743. **   (x & ~(map[x]&0x20))

  19744. **

  19745. ** The equivalent of tolower() is implemented using the sqlite3UpperToLower[]

  19746. ** array. tolower() is used more often than toupper() by SQLite.

  19747. **

  19748. ** Bit 0x40 is set if the character is non-alphanumeric and can be used in an 

  19749. ** SQLite identifier.  Identifiers are alphanumerics, "_", "$", and any

  19750. ** non-ASCII UTF character. Hence the test for whether or not a character is

  19751. ** part of an identifier is 0x46.

  19752. */

  19753. #ifdef SQLITE_ASCII

  19754. SQLITE_PRIVATE const unsigned char sqlite3CtypeMap[256] = {

  19755.   0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,  /* 00..07    ........ */

  19756.   0x00, 0x01, 0x01, 0x01, 0x01, 0x01, 0x00, 0x00,  /* 08..0f    ........ */

  19757.   0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,  /* 10..17    ........ */

  19758.   0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,  /* 18..1f    ........ */

  19759.   0x01, 0x00, 0x80, 0x00, 0x40, 0x00, 0x00, 0x80,  /* 20..27     !"#$%&' */

  19760.   0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,  /* 28..2f    ()*+,-./ */

  19761.   0x0c, 0x0c, 0x0c, 0x0c, 0x0c, 0x0c, 0x0c, 0x0c,  /* 30..37    01234567 */

  19762.   0x0c, 0x0c, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,  /* 38..3f    89:;<=>? */

  19763. 

  19764.   0x00, 0x0a, 0x0a, 0x0a, 0x0a, 0x0a, 0x0a, 0x02,  /* 40..47    @ABCDEFG */

  19765.   0x02, 0x02, 0x02, 0x02, 0x02, 0x02, 0x02, 0x02,  /* 48..4f    HIJKLMNO */

  19766.   0x02, 0x02, 0x02, 0x02, 0x02, 0x02, 0x02, 0x02,  /* 50..57    PQRSTUVW */

  19767.   0x02, 0x02, 0x02, 0x80, 0x00, 0x00, 0x00, 0x40,  /* 58..5f    XYZ[\]^_ */

  19768.   0x80, 0x2a, 0x2a, 0x2a, 0x2a, 0x2a, 0x2a, 0x22,  /* 60..67    `abcdefg */

  19769.   0x22, 0x22, 0x22, 0x22, 0x22, 0x22, 0x22, 0x22,  /* 68..6f    hijklmno */

  19770.   0x22, 0x22, 0x22, 0x22, 0x22, 0x22, 0x22, 0x22,  /* 70..77    pqrstuvw */

  19771.   0x22, 0x22, 0x22, 0x00, 0x00, 0x00, 0x00, 0x00,  /* 78..7f    xyz{|}~. */

  19772. 

  19773.   0x40, 0x40, 0x40, 0x40, 0x40, 0x40, 0x40, 0x40,  /* 80..87    ........ */

  19774.   0x40, 0x40, 0x40, 0x40, 0x40, 0x40, 0x40, 0x40,  /* 88..8f    ........ */

  19775.   0x40, 0x40, 0x40, 0x40, 0x40, 0x40, 0x40, 0x40,  /* 90..97    ........ */

  19776.   0x40, 0x40, 0x40, 0x40, 0x40, 0x40, 0x40, 0x40,  /* 98..9f    ........ */

  19777.   0x40, 0x40, 0x40, 0x40, 0x40, 0x40, 0x40, 0x40,  /* a0..a7    ........ */

  19778.   0x40, 0x40, 0x40, 0x40, 0x40, 0x40, 0x40, 0x40,  /* a8..af    ........ */

  19779.   0x40, 0x40, 0x40, 0x40, 0x40, 0x40, 0x40, 0x40,  /* b0..b7    ........ */

  19780.   0x40, 0x40, 0x40, 0x40, 0x40, 0x40, 0x40, 0x40,  /* b8..bf    ........ */

  19781. 

  19782.   0x40, 0x40, 0x40, 0x40, 0x40, 0x40, 0x40, 0x40,  /* c0..c7    ........ */

  19783.   0x40, 0x40, 0x40, 0x40, 0x40, 0x40, 0x40, 0x40,  /* c8..cf    ........ */

  19784.   0x40, 0x40, 0x40, 0x40, 0x40, 0x40, 0x40, 0x40,  /* d0..d7    ........ */

  19785.   0x40, 0x40, 0x40, 0x40, 0x40, 0x40, 0x40, 0x40,  /* d8..df    ........ */

  19786.   0x40, 0x40, 0x40, 0x40, 0x40, 0x40, 0x40, 0x40,  /* e0..e7    ........ */

  19787.   0x40, 0x40, 0x40, 0x40, 0x40, 0x40, 0x40, 0x40,  /* e8..ef    ........ */

  19788.   0x40, 0x40, 0x40, 0x40, 0x40, 0x40, 0x40, 0x40,  /* f0..f7    ........ */

  19789.   0x40, 0x40, 0x40, 0x40, 0x40, 0x40, 0x40, 0x40   /* f8..ff    ........ */

  19790. };

  19791. #endif

  19792. 

  19793. /* EVIDENCE-OF: R-02982-34736 In order to maintain full backwards

  19794. ** compatibility for legacy applications, the URI filename capability is

  19795. ** disabled by default.

  19796. **

  19797. ** EVIDENCE-OF: R-38799-08373 URI filenames can be enabled or disabled

  19798. ** using the SQLITE_USE_URI=1 or SQLITE_USE_URI=0 compile-time options.

  19799. **

  19800. ** EVIDENCE-OF: R-43642-56306 By default, URI handling is globally

  19801. ** disabled. The default value may be changed by compiling with the

  19802. ** SQLITE_USE_URI symbol defined.

  19803. **

  19804. ** URI filenames are enabled by default if SQLITE_HAS_CODEC is

  19805. ** enabled.

  19806. */

  19807. #ifndef SQLITE_USE_URI

  19808. # ifdef SQLITE_HAS_CODEC

  19809. #  define SQLITE_USE_URI 1

  19810. # else

  19811. #  define SQLITE_USE_URI 0

  19812. # endif

  19813. #endif

  19814. 

  19815. /* EVIDENCE-OF: R-38720-18127 The default setting is determined by the

  19816. ** SQLITE_ALLOW_COVERING_INDEX_SCAN compile-time option, or is "on" if

  19817. ** that compile-time option is omitted.

  19818. */

  19819. #if !defined(SQLITE_ALLOW_COVERING_INDEX_SCAN)

  19820. # define SQLITE_ALLOW_COVERING_INDEX_SCAN 1

  19821. #else

  19822. # if !SQLITE_ALLOW_COVERING_INDEX_SCAN 

  19823. #   error "Compile-time disabling of covering index scan using the\

  19824.  -DSQLITE_ALLOW_COVERING_INDEX_SCAN=0 option is deprecated.\

  19825.  Contact SQLite developers if this is a problem for you, and\

  19826.  delete this #error macro to continue with your build."

  19827. # endif

  19828. #endif

  19829. 

  19830. /* The minimum PMA size is set to this value multiplied by the database

  19831. ** page size in bytes.

  19832. */

  19833. #ifndef SQLITE_SORTER_PMASZ

  19834. # define SQLITE_SORTER_PMASZ 250

  19835. #endif

  19836. 

  19837. /* Statement journals spill to disk when their size exceeds the following

  19838. ** threshold (in bytes). 0 means that statement journals are created and

  19839. ** written to disk immediately (the default behavior for SQLite versions

  19840. ** before 3.12.0).  -1 means always keep the entire statement journal in

  19841. ** memory.  (The statement journal is also always held entirely in memory

  19842. ** if journal_mode=MEMORY or if temp_store=MEMORY, regardless of this

  19843. ** setting.)

  19844. */

  19845. #ifndef SQLITE_STMTJRNL_SPILL 

  19846. # define SQLITE_STMTJRNL_SPILL (64*1024)

  19847. #endif

  19848. 

  19849. /*

  19850. ** The default lookaside-configuration, the format "SZ,N".  SZ is the

  19851. ** number of bytes in each lookaside slot (should be a multiple of 8)

  19852. ** and N is the number of slots.  The lookaside-configuration can be

  19853. ** changed as start-time using sqlite3_config(SQLITE_CONFIG_LOOKASIDE)

  19854. ** or at run-time for an individual database connection using

  19855. ** sqlite3_db_config(db, SQLITE_DBCONFIG_LOOKASIDE);

  19856. */

  19857. #ifndef SQLITE_DEFAULT_LOOKASIDE

  19858. # define SQLITE_DEFAULT_LOOKASIDE 1200,100

  19859. #endif

  19860. 

  19861. 

  19862. /* The default maximum size of an in-memory database created using

  19863. ** sqlite3_deserialize()

  19864. */

  19865. #ifndef SQLITE_MEMDB_DEFAULT_MAXSIZE

  19866. # define SQLITE_MEMDB_DEFAULT_MAXSIZE 1073741824

  19867. #endif

  19868. 

  19869. /*

  19870. ** The following singleton contains the global configuration for

  19871. ** the SQLite library.

  19872. */

  19873. SQLITE_PRIVATE SQLITE_WSD struct Sqlite3Config sqlite3Config = {

  19874.    SQLITE_DEFAULT_MEMSTATUS,  /* bMemstat */

  19875.    1,                         /* bCoreMutex */

  19876.    SQLITE_THREADSAFE==1,      /* bFullMutex */

  19877.    SQLITE_USE_URI,            /* bOpenUri */

  19878.    SQLITE_ALLOW_COVERING_INDEX_SCAN,   /* bUseCis */

  19879.    0,                         /* bSmallMalloc */

  19880.    0x7ffffffe,                /* mxStrlen */

  19881.    0,                         /* neverCorrupt */

  19882.    SQLITE_DEFAULT_LOOKASIDE,  /* szLookaside, nLookaside */

  19883.    SQLITE_STMTJRNL_SPILL,     /* nStmtSpill */

  19884.    {0,0,0,0,0,0,0,0},         /* m */

  19885.    {0,0,0,0,0,0,0,0,0},       /* mutex */

  19886.    {0,0,0,0,0,0,0,0,0,0,0,0,0},/* pcache2 */

  19887.    (void*)0,                  /* pHeap */

  19888.    0,                         /* nHeap */

  19889.    0, 0,                      /* mnHeap, mxHeap */

  19890.    SQLITE_DEFAULT_MMAP_SIZE,  /* szMmap */

  19891.    SQLITE_MAX_MMAP_SIZE,      /* mxMmap */

  19892.    (void*)0,                  /* pPage */

  19893.    0,                         /* szPage */

  19894.    SQLITE_DEFAULT_PCACHE_INITSZ, /* nPage */

  19895.    0,                         /* mxParserStack */

  19896.    0,                         /* sharedCacheEnabled */

  19897.    SQLITE_SORTER_PMASZ,       /* szPma */

  19898.    /* All the rest should always be initialized to zero */

  19899.    0,                         /* isInit */

  19900.    0,                         /* inProgress */

  19901.    0,                         /* isMutexInit */

  19902.    0,                         /* isMallocInit */

  19903.    0,                         /* isPCacheInit */

  19904.    0,                         /* nRefInitMutex */

  19905.    0,                         /* pInitMutex */

  19906.    0,                         /* xLog */

  19907.    0,                         /* pLogArg */

  19908. #ifdef SQLITE_ENABLE_SQLLOG

  19909.    0,                         /* xSqllog */

  19910.    0,                         /* pSqllogArg */

  19911. #endif

  19912. #ifdef SQLITE_VDBE_COVERAGE

  19913.    0,                         /* xVdbeBranch */

  19914.    0,                         /* pVbeBranchArg */

  19915. #endif

  19916. #ifdef SQLITE_ENABLE_DESERIALIZE

  19917.    SQLITE_MEMDB_DEFAULT_MAXSIZE,   /* mxMemdbSize */

  19918. #endif

  19919. #ifndef SQLITE_UNTESTABLE

  19920.    0,                         /* xTestCallback */

  19921. #endif

  19922.    0,                         /* bLocaltimeFault */

  19923.    0,                         /* bInternalFunctions */

  19924.    0x7ffffffe,                /* iOnceResetThreshold */

  19925.    SQLITE_DEFAULT_SORTERREF_SIZE,   /* szSorterRef */

  19926. };

  19927. 

  19928. /*

  19929. ** Hash table for global functions - functions common to all

  19930. ** database connections.  After initialization, this table is

  19931. ** read-only.

  19932. */

  19933. SQLITE_PRIVATE FuncDefHash sqlite3BuiltinFunctions;

  19934. 

  19935. /*

  19936. ** Constant tokens for values 0 and 1.

  19937. */

  19938. SQLITE_PRIVATE const Token sqlite3IntTokens[] = {

  19939.    { "0", 1 },

  19940.    { "1", 1 }

  19941. };

  19942. 

  19943. #ifdef VDBE_PROFILE

  19944. /*

  19945. ** The following performance counter can be used in place of

  19946. ** sqlite3Hwtime() for profiling.  This is a no-op on standard builds.

  19947. */

  19948. SQLITE_PRIVATE sqlite3_uint64 sqlite3NProfileCnt = 0;

  19949. #endif

  19950. 

  19951. /*

  19952. ** The value of the "pending" byte must be 0x40000000 (1 byte past the

  19953. ** 1-gibabyte boundary) in a compatible database.  SQLite never uses

  19954. ** the database page that contains the pending byte.  It never attempts

  19955. ** to read or write that page.  The pending byte page is set aside

  19956. ** for use by the VFS layers as space for managing file locks.

  19957. **

  19958. ** During testing, it is often desirable to move the pending byte to

  19959. ** a different position in the file.  This allows code that has to

  19960. ** deal with the pending byte to run on files that are much smaller

  19961. ** than 1 GiB.  The sqlite3_test_control() interface can be used to

  19962. ** move the pending byte.

  19963. **

  19964. ** IMPORTANT:  Changing the pending byte to any value other than

  19965. ** 0x40000000 results in an incompatible database file format!

  19966. ** Changing the pending byte during operation will result in undefined

  19967. ** and incorrect behavior.

  19968. */

  19969. #ifndef SQLITE_OMIT_WSD

  19970. SQLITE_PRIVATE int sqlite3PendingByte = 0x40000000;

  19971. #endif

  19972. 

  19973. /* #include "opcodes.h" */

  19974. /*

  19975. ** Properties of opcodes.  The OPFLG_INITIALIZER macro is

  19976. ** created by mkopcodeh.awk during compilation.  Data is obtained

  19977. ** from the comments following the "case OP_xxxx:" statements in

  19978. ** the vdbe.c file.  

  19979. */

  19980. SQLITE_PRIVATE const unsigned char sqlite3OpcodeProperty[] = OPFLG_INITIALIZER;

  19981. 

  19982. /*

  19983. ** Name of the default collating sequence

  19984. */

  19985. SQLITE_PRIVATE const char sqlite3StrBINARY[] = "BINARY";

  19986. 

  19987. /************** End of global.c **********************************************/

  19988. /************** Begin file status.c ******************************************/

  19989. /*

  19990. ** 2008 June 18

  19991. **

  19992. ** The author disclaims copyright to this source code.  In place of

  19993. ** a legal notice, here is a blessing:

  19994. **

  19995. **    May you do good and not evil.

  19996. **    May you find forgiveness for yourself and forgive others.

  19997. **    May you share freely, never taking more than you give.

  19998. **

  19999. *************************************************************************

  20000. **

  20001. ** This module implements the sqlite3_status() interface and related

  20002. ** functionality.

  20003. */

  20004. /* #include "sqliteInt.h" */

  20005. /************** Include vdbeInt.h in the middle of status.c ******************/

  20006. /************** Begin file vdbeInt.h *****************************************/

  20007. /*

  20008. ** 2003 September 6

  20009. **

  20010. ** The author disclaims copyright to this source code.  In place of

  20011. ** a legal notice, here is a blessing:

  20012. **

  20013. **    May you do good and not evil.

  20014. **    May you find forgiveness for yourself and forgive others.

  20015. **    May you share freely, never taking more than you give.

  20016. **

  20017. *************************************************************************

  20018. ** This is the header file for information that is private to the

  20019. ** VDBE.  This information used to all be at the top of the single

  20020. ** source code file "vdbe.c".  When that file became too big (over

  20021. ** 6000 lines long) it was split up into several smaller files and

  20022. ** this header information was factored out.

  20023. */

  20024. #ifndef SQLITE_VDBEINT_H

  20025. #define SQLITE_VDBEINT_H

  20026. 

  20027. /*

  20028. ** The maximum number of times that a statement will try to reparse

  20029. ** itself before giving up and returning SQLITE_SCHEMA.

  20030. */

  20031. #ifndef SQLITE_MAX_SCHEMA_RETRY

  20032. # define SQLITE_MAX_SCHEMA_RETRY 50

  20033. #endif

  20034. 

  20035. /*

  20036. ** VDBE_DISPLAY_P4 is true or false depending on whether or not the

  20037. ** "explain" P4 display logic is enabled.

  20038. */

  20039. #if !defined(SQLITE_OMIT_EXPLAIN) || !defined(NDEBUG) \

  20040.      || defined(VDBE_PROFILE) || defined(SQLITE_DEBUG)

  20041. # define VDBE_DISPLAY_P4 1

  20042. #else

  20043. # define VDBE_DISPLAY_P4 0

  20044. #endif

  20045. 

  20046. /*

  20047. ** SQL is translated into a sequence of instructions to be

  20048. ** executed by a virtual machine.  Each instruction is an instance

  20049. ** of the following structure.

  20050. */

  20051. typedef struct VdbeOp Op;

  20052. 

  20053. /*

  20054. ** Boolean values

  20055. */

  20056. typedef unsigned Bool;

  20057. 

  20058. /* Opaque type used by code in vdbesort.c */

  20059. typedef struct VdbeSorter VdbeSorter;

  20060. 

  20061. /* Elements of the linked list at Vdbe.pAuxData */

  20062. typedef struct AuxData AuxData;

  20063. 

  20064. /* Types of VDBE cursors */

  20065. #define CURTYPE_BTREE       0

  20066. #define CURTYPE_SORTER      1

  20067. #define CURTYPE_VTAB        2

  20068. #define CURTYPE_PSEUDO      3

  20069. 

  20070. /*

  20071. ** A VdbeCursor is an superclass (a wrapper) for various cursor objects:

  20072. **

  20073. **      * A b-tree cursor

  20074. **          -  In the main database or in an ephemeral database

  20075. **          -  On either an index or a table

  20076. **      * A sorter

  20077. **      * A virtual table

  20078. **      * A one-row "pseudotable" stored in a single register

  20079. */

  20080. typedef struct VdbeCursor VdbeCursor;

  20081. struct VdbeCursor {

  20082.   u8 eCurType;            /* One of the CURTYPE_* values above */

  20083.   i8 iDb;                 /* Index of cursor database in db->aDb[] (or -1) */

  20084.   u8 nullRow;             /* True if pointing to a row with no data */

  20085.   u8 deferredMoveto;      /* A call to sqlite3BtreeMoveto() is needed */

  20086.   u8 isTable;             /* True for rowid tables.  False for indexes */

  20087. #ifdef SQLITE_DEBUG

  20088.   u8 seekOp;              /* Most recent seek operation on this cursor */

  20089.   u8 wrFlag;              /* The wrFlag argument to sqlite3BtreeCursor() */

  20090. #endif

  20091.   Bool isEphemeral:1;     /* True for an ephemeral table */

  20092.   Bool useRandomRowid:1;  /* Generate new record numbers semi-randomly */

  20093.   Bool isOrdered:1;       /* True if the table is not BTREE_UNORDERED */

  20094.   Bool seekHit:1;         /* See the OP_SeekHit and OP_IfNoHope opcodes */

  20095.   Btree *pBtx;            /* Separate file holding temporary table */

  20096.   i64 seqCount;           /* Sequence counter */

  20097.   int *aAltMap;           /* Mapping from table to index column numbers */

  20098. 

  20099.   /* Cached OP_Column parse information is only valid if cacheStatus matches

  20100.   ** Vdbe.cacheCtr.  Vdbe.cacheCtr will never take on the value of

  20101.   ** CACHE_STALE (0) and so setting cacheStatus=CACHE_STALE guarantees that

  20102.   ** the cache is out of date. */

  20103.   u32 cacheStatus;        /* Cache is valid if this matches Vdbe.cacheCtr */

  20104.   int seekResult;         /* Result of previous sqlite3BtreeMoveto() or 0

  20105.                           ** if there have been no prior seeks on the cursor. */

  20106.   /* seekResult does not distinguish between "no seeks have ever occurred

  20107.   ** on this cursor" and "the most recent seek was an exact match".

  20108.   ** For CURTYPE_PSEUDO, seekResult is the register holding the record */

  20109. 

  20110.   /* When a new VdbeCursor is allocated, only the fields above are zeroed.

  20111.   ** The fields that follow are uninitialized, and must be individually

  20112.   ** initialized prior to first use. */

  20113.   VdbeCursor *pAltCursor; /* Associated index cursor from which to read */

  20114.   union {

  20115.     BtCursor *pCursor;          /* CURTYPE_BTREE or _PSEUDO.  Btree cursor */

  20116.     sqlite3_vtab_cursor *pVCur; /* CURTYPE_VTAB.              Vtab cursor */

  20117.     VdbeSorter *pSorter;        /* CURTYPE_SORTER.            Sorter object */

  20118.   } uc;

  20119.   KeyInfo *pKeyInfo;      /* Info about index keys needed by index cursors */

  20120.   u32 iHdrOffset;         /* Offset to next unparsed byte of the header */

  20121.   Pgno pgnoRoot;          /* Root page of the open btree cursor */

  20122.   i16 nField;             /* Number of fields in the header */

  20123.   u16 nHdrParsed;         /* Number of header fields parsed so far */

  20124.   i64 movetoTarget;       /* Argument to the deferred sqlite3BtreeMoveto() */

  20125.   u32 *aOffset;           /* Pointer to aType[nField] */

  20126.   const u8 *aRow;         /* Data for the current row, if all on one page */

  20127.   u32 payloadSize;        /* Total number of bytes in the record */

  20128.   u32 szRow;              /* Byte available in aRow */

  20129. #ifdef SQLITE_ENABLE_COLUMN_USED_MASK

  20130.   u64 maskUsed;           /* Mask of columns used by this cursor */

  20131. #endif

  20132. 

  20133.   /* 2*nField extra array elements allocated for aType[], beyond the one

  20134.   ** static element declared in the structure.  nField total array slots for

  20135.   ** aType[] and nField+1 array slots for aOffset[] */

  20136.   u32 aType[1];           /* Type values record decode.  MUST BE LAST */

  20137. };

  20138. 

  20139. 

  20140. /*

  20141. ** A value for VdbeCursor.cacheStatus that means the cache is always invalid.

  20142. */

  20143. #define CACHE_STALE 0

  20144. 

  20145. /*

  20146. ** When a sub-program is executed (OP_Program), a structure of this type

  20147. ** is allocated to store the current value of the program counter, as

  20148. ** well as the current memory cell array and various other frame specific

  20149. ** values stored in the Vdbe struct. When the sub-program is finished, 

  20150. ** these values are copied back to the Vdbe from the VdbeFrame structure,

  20151. ** restoring the state of the VM to as it was before the sub-program

  20152. ** began executing.

  20153. **

  20154. ** The memory for a VdbeFrame object is allocated and managed by a memory

  20155. ** cell in the parent (calling) frame. When the memory cell is deleted or

  20156. ** overwritten, the VdbeFrame object is not freed immediately. Instead, it

  20157. ** is linked into the Vdbe.pDelFrame list. The contents of the Vdbe.pDelFrame

  20158. ** list is deleted when the VM is reset in VdbeHalt(). The reason for doing

  20159. ** this instead of deleting the VdbeFrame immediately is to avoid recursive

  20160. ** calls to sqlite3VdbeMemRelease() when the memory cells belonging to the

  20161. ** child frame are released.

  20162. **

  20163. ** The currently executing frame is stored in Vdbe.pFrame. Vdbe.pFrame is

  20164. ** set to NULL if the currently executing frame is the main program.

  20165. */

  20166. typedef struct VdbeFrame VdbeFrame;

  20167. struct VdbeFrame {

  20168.   Vdbe *v;                /* VM this frame belongs to */

  20169.   VdbeFrame *pParent;     /* Parent of this frame, or NULL if parent is main */

  20170.   Op *aOp;                /* Program instructions for parent frame */

  20171.   i64 *anExec;            /* Event counters from parent frame */

  20172.   Mem *aMem;              /* Array of memory cells for parent frame */

  20173.   VdbeCursor **apCsr;     /* Array of Vdbe cursors for parent frame */

  20174.   u8 *aOnce;              /* Bitmask used by OP_Once */

  20175.   void *token;            /* Copy of SubProgram.token */

  20176.   i64 lastRowid;          /* Last insert rowid (sqlite3.lastRowid) */

  20177.   AuxData *pAuxData;      /* Linked list of auxdata allocations */

  20178. #if SQLITE_DEBUG

  20179.   u32 iFrameMagic;        /* magic number for sanity checking */

  20180. #endif

  20181.   int nCursor;            /* Number of entries in apCsr */

  20182.   int pc;                 /* Program Counter in parent (calling) frame */

  20183.   int nOp;                /* Size of aOp array */

  20184.   int nMem;               /* Number of entries in aMem */

  20185.   int nChildMem;          /* Number of memory cells for child frame */

  20186.   int nChildCsr;          /* Number of cursors for child frame */

  20187.   int nChange;            /* Statement changes (Vdbe.nChange)     */

  20188.   int nDbChange;          /* Value of db->nChange */

  20189. };

  20190. 

  20191. /* Magic number for sanity checking on VdbeFrame objects */

  20192. #define SQLITE_FRAME_MAGIC 0x879fb71e

  20193. 

  20194. /*

  20195. ** Return a pointer to the array of registers allocated for use

  20196. ** by a VdbeFrame.

  20197. */

  20198. #define VdbeFrameMem(p) ((Mem *)&((u8 *)p)[ROUND8(sizeof(VdbeFrame))])

  20199. 

  20200. /*

  20201. ** Internally, the vdbe manipulates nearly all SQL values as Mem

  20202. ** structures. Each Mem struct may cache multiple representations (string,

  20203. ** integer etc.) of the same value.

  20204. */

  20205. struct sqlite3_value {

  20206.   union MemValue {

  20207.     double r;           /* Real value used when MEM_Real is set in flags */

  20208.     i64 i;              /* Integer value used when MEM_Int is set in flags */

  20209.     int nZero;          /* Extra zero bytes when MEM_Zero and MEM_Blob set */

  20210.     const char *zPType; /* Pointer type when MEM_Term|MEM_Subtype|MEM_Null */

  20211.     FuncDef *pDef;      /* Used only when flags==MEM_Agg */

  20212.   } u;

  20213.   u16 flags;          /* Some combination of MEM_Null, MEM_Str, MEM_Dyn, etc. */

  20214.   u8  enc;            /* SQLITE_UTF8, SQLITE_UTF16BE, SQLITE_UTF16LE */

  20215.   u8  eSubtype;       /* Subtype for this value */

  20216.   int n;              /* Number of characters in string value, excluding '\0' */

  20217.   char *z;            /* String or BLOB value */

  20218.   /* ShallowCopy only needs to copy the information above */

  20219.   char *zMalloc;      /* Space to hold MEM_Str or MEM_Blob if szMalloc>0 */

  20220.   int szMalloc;       /* Size of the zMalloc allocation */

  20221.   u32 uTemp;          /* Transient storage for serial_type in OP_MakeRecord */

  20222.   sqlite3 *db;        /* The associated database connection */

  20223.   void (*xDel)(void*);/* Destructor for Mem.z - only valid if MEM_Dyn */

  20224. #ifdef SQLITE_DEBUG

  20225.   Mem *pScopyFrom;    /* This Mem is a shallow copy of pScopyFrom */

  20226.   u16 mScopyFlags;    /* flags value immediately after the shallow copy */

  20227. #endif

  20228. };

  20229. 

  20230. /*

  20231. ** Size of struct Mem not including the Mem.zMalloc member or anything that

  20232. ** follows.

  20233. */

  20234. #define MEMCELLSIZE offsetof(Mem,zMalloc)

  20235. 

  20236. /* One or more of the following flags are set to indicate the validOK

  20237. ** representations of the value stored in the Mem struct.

  20238. **

  20239. ** If the MEM_Null flag is set, then the value is an SQL NULL value.

  20240. ** For a pointer type created using sqlite3_bind_pointer() or

  20241. ** sqlite3_result_pointer() the MEM_Term and MEM_Subtype flags are also set.

  20242. **

  20243. ** If the MEM_Str flag is set then Mem.z points at a string representation.

  20244. ** Usually this is encoded in the same unicode encoding as the main

  20245. ** database (see below for exceptions). If the MEM_Term flag is also

  20246. ** set, then the string is nul terminated. The MEM_Int and MEM_Real 

  20247. ** flags may coexist with the MEM_Str flag.

  20248. */

  20249. #define MEM_Null      0x0001   /* Value is NULL (or a pointer) */

  20250. #define MEM_Str       0x0002   /* Value is a string */

  20251. #define MEM_Int       0x0004   /* Value is an integer */

  20252. #define MEM_Real      0x0008   /* Value is a real number */

  20253. #define MEM_Blob      0x0010   /* Value is a BLOB */

  20254. #define MEM_IntReal   0x0020   /* MEM_Int that stringifies like MEM_Real */

  20255. #define MEM_AffMask   0x003f   /* Mask of affinity bits */

  20256. #define MEM_FromBind  0x0040   /* Value originates from sqlite3_bind() */

  20257. #define MEM_Undefined 0x0080   /* Value is undefined */

  20258. #define MEM_Cleared   0x0100   /* NULL set by OP_Null, not from data */

  20259. #define MEM_TypeMask  0xc1bf   /* Mask of type bits */

  20260. 

  20261. 

  20262. /* Whenever Mem contains a valid string or blob representation, one of

  20263. ** the following flags must be set to determine the memory management

  20264. ** policy for Mem.z.  The MEM_Term flag tells us whether or not the

  20265. ** string is \000 or \u0000 terminated

  20266. */

  20267. #define MEM_Term      0x0200   /* String in Mem.z is zero terminated */

  20268. #define MEM_Dyn       0x0400   /* Need to call Mem.xDel() on Mem.z */

  20269. #define MEM_Static    0x0800   /* Mem.z points to a static string */

  20270. #define MEM_Ephem     0x1000   /* Mem.z points to an ephemeral string */

  20271. #define MEM_Agg       0x2000   /* Mem.z points to an agg function context */

  20272. #define MEM_Zero      0x4000   /* Mem.i contains count of 0s appended to blob */

  20273. #define MEM_Subtype   0x8000   /* Mem.eSubtype is valid */

  20274. #ifdef SQLITE_OMIT_INCRBLOB

  20275.   #undef MEM_Zero

  20276.   #define MEM_Zero 0x0000

  20277. #endif

  20278. 

  20279. /* Return TRUE if Mem X contains dynamically allocated content - anything

  20280. ** that needs to be deallocated to avoid a leak.

  20281. */

  20282. #define VdbeMemDynamic(X)  \

  20283.   (((X)->flags&(MEM_Agg|MEM_Dyn))!=0)

  20284. 

  20285. /*

  20286. ** Clear any existing type flags from a Mem and replace them with f

  20287. */

  20288. #define MemSetTypeFlag(p, f) \

  20289.    ((p)->flags = ((p)->flags&~(MEM_TypeMask|MEM_Zero))|f)

  20290. 

  20291. /*

  20292. ** True if Mem X is a NULL-nochng type.

  20293. */

  20294. #define MemNullNochng(X) \

  20295.   ((X)->flags==(MEM_Null|MEM_Zero) && (X)->n==0 && (X)->u.nZero==0)

  20296. 

  20297. /*

  20298. ** Return true if a memory cell is not marked as invalid.  This macro

  20299. ** is for use inside assert() statements only.

  20300. */

  20301. #ifdef SQLITE_DEBUG

  20302. #define memIsValid(M)  ((M)->flags & MEM_Undefined)==0

  20303. #endif

  20304. 

  20305. /*

  20306. ** Each auxiliary data pointer stored by a user defined function 

  20307. ** implementation calling sqlite3_set_auxdata() is stored in an instance

  20308. ** of this structure. All such structures associated with a single VM

  20309. ** are stored in a linked list headed at Vdbe.pAuxData. All are destroyed

  20310. ** when the VM is halted (if not before).

  20311. */

  20312. struct AuxData {

  20313.   int iAuxOp;                     /* Instruction number of OP_Function opcode */

  20314.   int iAuxArg;                    /* Index of function argument. */

  20315.   void *pAux;                     /* Aux data pointer */

  20316.   void (*xDeleteAux)(void*);      /* Destructor for the aux data */

  20317.   AuxData *pNextAux;              /* Next element in list */

  20318. };

  20319. 

  20320. /*

  20321. ** The "context" argument for an installable function.  A pointer to an

  20322. ** instance of this structure is the first argument to the routines used

  20323. ** implement the SQL functions.

  20324. **

  20325. ** There is a typedef for this structure in sqlite.h.  So all routines,

  20326. ** even the public interface to SQLite, can use a pointer to this structure.

  20327. ** But this file is the only place where the internal details of this

  20328. ** structure are known.

  20329. **

  20330. ** This structure is defined inside of vdbeInt.h because it uses substructures

  20331. ** (Mem) which are only defined there.

  20332. */

  20333. struct sqlite3_context {

  20334.   Mem *pOut;              /* The return value is stored here */

  20335.   FuncDef *pFunc;         /* Pointer to function information */

  20336.   Mem *pMem;              /* Memory cell used to store aggregate context */

  20337.   Vdbe *pVdbe;            /* The VM that owns this context */

  20338.   int iOp;                /* Instruction number of OP_Function */

  20339.   int isError;            /* Error code returned by the function. */

  20340.   u8 skipFlag;            /* Skip accumulator loading if true */

  20341.   u8 argc;                /* Number of arguments */

  20342.   sqlite3_value *argv[1]; /* Argument set */

  20343. };

  20344. 

  20345. /* A bitfield type for use inside of structures.  Always follow with :N where

  20346. ** N is the number of bits.

  20347. */

  20348. typedef unsigned bft;  /* Bit Field Type */

  20349. 

  20350. /* The ScanStatus object holds a single value for the

  20351. ** sqlite3_stmt_scanstatus() interface.

  20352. */

  20353. typedef struct ScanStatus ScanStatus;

  20354. struct ScanStatus {

  20355.   int addrExplain;                /* OP_Explain for loop */

  20356.   int addrLoop;                   /* Address of "loops" counter */

  20357.   int addrVisit;                  /* Address of "rows visited" counter */

  20358.   int iSelectID;                  /* The "Select-ID" for this loop */

  20359.   LogEst nEst;                    /* Estimated output rows per loop */

  20360.   char *zName;                    /* Name of table or index */

  20361. };

  20362. 

  20363. /* The DblquoteStr object holds the text of a double-quoted

  20364. ** string for a prepared statement.  A linked list of these objects

  20365. ** is constructed during statement parsing and is held on Vdbe.pDblStr.

  20366. ** When computing a normalized SQL statement for an SQL statement, that

  20367. ** list is consulted for each double-quoted identifier to see if the

  20368. ** identifier should really be a string literal.

  20369. */

  20370. typedef struct DblquoteStr DblquoteStr;

  20371. struct DblquoteStr {

  20372.   DblquoteStr *pNextStr;   /* Next string literal in the list */

  20373.   char z[8];               /* Dequoted value for the string */

  20374. };

  20375. 

  20376. /*

  20377. ** An instance of the virtual machine.  This structure contains the complete

  20378. ** state of the virtual machine.

  20379. **

  20380. ** The "sqlite3_stmt" structure pointer that is returned by sqlite3_prepare()

  20381. ** is really a pointer to an instance of this structure.

  20382. */

  20383. struct Vdbe {

  20384.   sqlite3 *db;            /* The database connection that owns this statement */

  20385.   Vdbe *pPrev,*pNext;     /* Linked list of VDBEs with the same Vdbe.db */

  20386.   Parse *pParse;          /* Parsing context used to create this Vdbe */

  20387.   ynVar nVar;             /* Number of entries in aVar[] */

  20388.   u32 magic;              /* Magic number for sanity checking */

  20389.   int nMem;               /* Number of memory locations currently allocated */

  20390.   int nCursor;            /* Number of slots in apCsr[] */

  20391.   u32 cacheCtr;           /* VdbeCursor row cache generation counter */

  20392.   int pc;                 /* The program counter */

  20393.   int rc;                 /* Value to return */

  20394.   int nChange;            /* Number of db changes made since last reset */

  20395.   int iStatement;         /* Statement number (or 0 if has no opened stmt) */

  20396.   i64 iCurrentTime;       /* Value of julianday('now') for this statement */

  20397.   i64 nFkConstraint;      /* Number of imm. FK constraints this VM */

  20398.   i64 nStmtDefCons;       /* Number of def. constraints when stmt started */

  20399.   i64 nStmtDefImmCons;    /* Number of def. imm constraints when stmt started */

  20400.   Mem *aMem;              /* The memory locations */

  20401.   Mem **apArg;            /* Arguments to currently executing user function */

  20402.   VdbeCursor **apCsr;     /* One element of this array for each open cursor */

  20403.   Mem *aVar;              /* Values for the OP_Variable opcode. */

  20404. 

  20405.   /* When allocating a new Vdbe object, all of the fields below should be

  20406.   ** initialized to zero or NULL */

  20407. 

  20408.   Op *aOp;                /* Space to hold the virtual machine's program */

  20409.   int nOp;                /* Number of instructions in the program */

  20410.   int nOpAlloc;           /* Slots allocated for aOp[] */

  20411.   Mem *aColName;          /* Column names to return */

  20412.   Mem *pResultSet;        /* Pointer to an array of results */

  20413.   char *zErrMsg;          /* Error message written here */

  20414.   VList *pVList;          /* Name of variables */

  20415. #ifndef SQLITE_OMIT_TRACE

  20416.   i64 startTime;          /* Time when query started - used for profiling */

  20417. #endif

  20418. #ifdef SQLITE_DEBUG

  20419.   int rcApp;              /* errcode set by sqlite3_result_error_code() */

  20420.   u32 nWrite;             /* Number of write operations that have occurred */

  20421. #endif

  20422.   u16 nResColumn;         /* Number of columns in one row of the result set */

  20423.   u8 errorAction;         /* Recovery action to do in case of an error */

  20424.   u8 minWriteFileFormat;  /* Minimum file format for writable database files */

  20425.   u8 prepFlags;           /* SQLITE_PREPARE_* flags */

  20426.   bft expired:2;          /* 1: recompile VM immediately  2: when convenient */

  20427.   bft explain:2;          /* True if EXPLAIN present on SQL command */

  20428.   bft doingRerun:1;       /* True if rerunning after an auto-reprepare */

  20429.   bft changeCntOn:1;      /* True to update the change-counter */

  20430.   bft runOnlyOnce:1;      /* Automatically expire on reset */

  20431.   bft usesStmtJournal:1;  /* True if uses a statement journal */

  20432.   bft readOnly:1;         /* True for statements that do not write */

  20433.   bft bIsReader:1;        /* True for statements that read */

  20434.   yDbMask btreeMask;      /* Bitmask of db->aDb[] entries referenced */

  20435.   yDbMask lockMask;       /* Subset of btreeMask that requires a lock */

  20436.   u32 aCounter[7];        /* Counters used by sqlite3_stmt_status() */

  20437.   char *zSql;             /* Text of the SQL statement that generated this */

  20438. #ifdef SQLITE_ENABLE_NORMALIZE

  20439.   char *zNormSql;         /* Normalization of the associated SQL statement */

  20440.   DblquoteStr *pDblStr;   /* List of double-quoted string literals */

  20441. #endif

  20442.   void *pFree;            /* Free this when deleting the vdbe */

  20443.   VdbeFrame *pFrame;      /* Parent frame */

  20444.   VdbeFrame *pDelFrame;   /* List of frame objects to free on VM reset */

  20445.   int nFrame;             /* Number of frames in pFrame list */

  20446.   u32 expmask;            /* Binding to these vars invalidates VM */

  20447.   SubProgram *pProgram;   /* Linked list of all sub-programs used by VM */

  20448.   AuxData *pAuxData;      /* Linked list of auxdata allocations */

  20449. #ifdef SQLITE_ENABLE_STMT_SCANSTATUS

  20450.   i64 *anExec;            /* Number of times each op has been executed */

  20451.   int nScan;              /* Entries in aScan[] */

  20452.   ScanStatus *aScan;      /* Scan definitions for sqlite3_stmt_scanstatus() */

  20453. #endif

  20454. };

  20455. 

  20456. /*

  20457. ** The following are allowed values for Vdbe.magic

  20458. */

  20459. #define VDBE_MAGIC_INIT     0x16bceaa5    /* Building a VDBE program */

  20460. #define VDBE_MAGIC_RUN      0x2df20da3    /* VDBE is ready to execute */

  20461. #define VDBE_MAGIC_HALT     0x319c2973    /* VDBE has completed execution */

  20462. #define VDBE_MAGIC_RESET    0x48fa9f76    /* Reset and ready to run again */

  20463. #define VDBE_MAGIC_DEAD     0x5606c3c8    /* The VDBE has been deallocated */

  20464. 

  20465. /*

  20466. ** Structure used to store the context required by the 

  20467. ** sqlite3_preupdate_*() API functions.

  20468. */

  20469. struct PreUpdate {

  20470.   Vdbe *v;

  20471.   VdbeCursor *pCsr;               /* Cursor to read old values from */

  20472.   int op;                         /* One of SQLITE_INSERT, UPDATE, DELETE */

  20473.   u8 *aRecord;                    /* old.* database record */

  20474.   KeyInfo keyinfo;

  20475.   UnpackedRecord *pUnpacked;      /* Unpacked version of aRecord[] */

  20476.   UnpackedRecord *pNewUnpacked;   /* Unpacked version of new.* record */

  20477.   int iNewReg;                    /* Register for new.* values */

  20478.   i64 iKey1;                      /* First key value passed to hook */

  20479.   i64 iKey2;                      /* Second key value passed to hook */

  20480.   Mem *aNew;                      /* Array of new.* values */

  20481.   Table *pTab;                    /* Schema object being upated */          

  20482.   Index *pPk;                     /* PK index if pTab is WITHOUT ROWID */

  20483. };

  20484. 

  20485. /*

  20486. ** Function prototypes

  20487. */

  20488. SQLITE_PRIVATE void sqlite3VdbeError(Vdbe*, const char *, ...);

  20489. SQLITE_PRIVATE void sqlite3VdbeFreeCursor(Vdbe *, VdbeCursor*);

  20490. void sqliteVdbePopStack(Vdbe*,int);

  20491. SQLITE_PRIVATE int sqlite3VdbeCursorMoveto(VdbeCursor**, int*);

  20492. SQLITE_PRIVATE int sqlite3VdbeCursorRestore(VdbeCursor*);

  20493. SQLITE_PRIVATE u32 sqlite3VdbeSerialTypeLen(u32);

  20494. SQLITE_PRIVATE u8 sqlite3VdbeOneByteSerialTypeLen(u8);

  20495. SQLITE_PRIVATE u32 sqlite3VdbeSerialType(Mem*, int, u32*);

  20496. SQLITE_PRIVATE u32 sqlite3VdbeSerialPut(unsigned char*, Mem*, u32);

  20497. SQLITE_PRIVATE u32 sqlite3VdbeSerialGet(const unsigned char*, u32, Mem*);

  20498. SQLITE_PRIVATE void sqlite3VdbeDeleteAuxData(sqlite3*, AuxData**, int, int);

  20499. 

  20500. int sqlite2BtreeKeyCompare(BtCursor *, const void *, int, int, int *);

  20501. SQLITE_PRIVATE int sqlite3VdbeIdxKeyCompare(sqlite3*,VdbeCursor*,UnpackedRecord*,int*);

  20502. SQLITE_PRIVATE int sqlite3VdbeIdxRowid(sqlite3*, BtCursor*, i64*);

  20503. SQLITE_PRIVATE int sqlite3VdbeExec(Vdbe*);

  20504. #ifndef SQLITE_OMIT_EXPLAIN

  20505. SQLITE_PRIVATE int sqlite3VdbeList(Vdbe*);

  20506. #endif

  20507. SQLITE_PRIVATE int sqlite3VdbeHalt(Vdbe*);

  20508. SQLITE_PRIVATE int sqlite3VdbeChangeEncoding(Mem *, int);

  20509. SQLITE_PRIVATE int sqlite3VdbeMemTooBig(Mem*);

  20510. SQLITE_PRIVATE int sqlite3VdbeMemCopy(Mem*, const Mem*);

  20511. SQLITE_PRIVATE void sqlite3VdbeMemShallowCopy(Mem*, const Mem*, int);

  20512. SQLITE_PRIVATE void sqlite3VdbeMemMove(Mem*, Mem*);

  20513. SQLITE_PRIVATE int sqlite3VdbeMemNulTerminate(Mem*);

  20514. SQLITE_PRIVATE int sqlite3VdbeMemSetStr(Mem*, const char*, int, u8, void(*)(void*));

  20515. SQLITE_PRIVATE void sqlite3VdbeMemSetInt64(Mem*, i64);

  20516. #ifdef SQLITE_OMIT_FLOATING_POINT

  20517. # define sqlite3VdbeMemSetDouble sqlite3VdbeMemSetInt64

  20518. #else

  20519. SQLITE_PRIVATE   void sqlite3VdbeMemSetDouble(Mem*, double);

  20520. #endif

  20521. SQLITE_PRIVATE void sqlite3VdbeMemSetPointer(Mem*, void*, const char*, void(*)(void*));

  20522. SQLITE_PRIVATE void sqlite3VdbeMemInit(Mem*,sqlite3*,u16);

  20523. SQLITE_PRIVATE void sqlite3VdbeMemSetNull(Mem*);

  20524. SQLITE_PRIVATE void sqlite3VdbeMemSetZeroBlob(Mem*,int);

  20525. #ifdef SQLITE_DEBUG

  20526. SQLITE_PRIVATE int sqlite3VdbeMemIsRowSet(const Mem*);

  20527. #endif

  20528. SQLITE_PRIVATE int sqlite3VdbeMemSetRowSet(Mem*);

  20529. SQLITE_PRIVATE int sqlite3VdbeMemMakeWriteable(Mem*);

  20530. SQLITE_PRIVATE int sqlite3VdbeMemStringify(Mem*, u8, u8);

  20531. SQLITE_PRIVATE i64 sqlite3VdbeIntValue(Mem*);

  20532. SQLITE_PRIVATE int sqlite3VdbeMemIntegerify(Mem*);

  20533. SQLITE_PRIVATE double sqlite3VdbeRealValue(Mem*);

  20534. SQLITE_PRIVATE int sqlite3VdbeBooleanValue(Mem*, int ifNull);

  20535. SQLITE_PRIVATE void sqlite3VdbeIntegerAffinity(Mem*);

  20536. SQLITE_PRIVATE int sqlite3VdbeMemRealify(Mem*);

  20537. SQLITE_PRIVATE int sqlite3VdbeMemNumerify(Mem*);

  20538. SQLITE_PRIVATE void sqlite3VdbeMemCast(Mem*,u8,u8);

  20539. SQLITE_PRIVATE int sqlite3VdbeMemFromBtree(BtCursor*,u32,u32,Mem*);

  20540. SQLITE_PRIVATE void sqlite3VdbeMemRelease(Mem *p);

  20541. SQLITE_PRIVATE int sqlite3VdbeMemFinalize(Mem*, FuncDef*);

  20542. #ifndef SQLITE_OMIT_WINDOWFUNC

  20543. SQLITE_PRIVATE int sqlite3VdbeMemAggValue(Mem*, Mem*, FuncDef*);

  20544. #endif

  20545. #ifndef SQLITE_OMIT_EXPLAIN

  20546. SQLITE_PRIVATE const char *sqlite3OpcodeName(int);

  20547. #endif

  20548. SQLITE_PRIVATE int sqlite3VdbeMemGrow(Mem *pMem, int n, int preserve);

  20549. SQLITE_PRIVATE int sqlite3VdbeMemClearAndResize(Mem *pMem, int n);

  20550. SQLITE_PRIVATE int sqlite3VdbeCloseStatement(Vdbe *, int);

  20551. #ifdef SQLITE_DEBUG

  20552. SQLITE_PRIVATE int sqlite3VdbeFrameIsValid(VdbeFrame*);

  20553. #endif

  20554. SQLITE_PRIVATE void sqlite3VdbeFrameMemDel(void*);      /* Destructor on Mem */

  20555. SQLITE_PRIVATE void sqlite3VdbeFrameDelete(VdbeFrame*); /* Actually deletes the Frame */

  20556. SQLITE_PRIVATE int sqlite3VdbeFrameRestore(VdbeFrame *);

  20557. #ifdef SQLITE_ENABLE_PREUPDATE_HOOK

  20558. SQLITE_PRIVATE void sqlite3VdbePreUpdateHook(Vdbe*,VdbeCursor*,int,const char*,Table*,i64,int);

  20559. #endif

  20560. SQLITE_PRIVATE int sqlite3VdbeTransferError(Vdbe *p);

  20561. 

  20562. SQLITE_PRIVATE int sqlite3VdbeSorterInit(sqlite3 *, int, VdbeCursor *);

  20563. SQLITE_PRIVATE void sqlite3VdbeSorterReset(sqlite3 *, VdbeSorter *);

  20564. SQLITE_PRIVATE void sqlite3VdbeSorterClose(sqlite3 *, VdbeCursor *);

  20565. SQLITE_PRIVATE int sqlite3VdbeSorterRowkey(const VdbeCursor *, Mem *);

  20566. SQLITE_PRIVATE int sqlite3VdbeSorterNext(sqlite3 *, const VdbeCursor *);

  20567. SQLITE_PRIVATE int sqlite3VdbeSorterRewind(const VdbeCursor *, int *);

  20568. SQLITE_PRIVATE int sqlite3VdbeSorterWrite(const VdbeCursor *, Mem *);

  20569. SQLITE_PRIVATE int sqlite3VdbeSorterCompare(const VdbeCursor *, Mem *, int, int *);

  20570. 

  20571. #ifdef SQLITE_DEBUG

  20572. SQLITE_PRIVATE   void sqlite3VdbeIncrWriteCounter(Vdbe*, VdbeCursor*);

  20573. SQLITE_PRIVATE   void sqlite3VdbeAssertAbortable(Vdbe*);

  20574. #else

  20575. # define sqlite3VdbeIncrWriteCounter(V,C)

  20576. # define sqlite3VdbeAssertAbortable(V)

  20577. #endif

  20578. 

  20579. #if !defined(SQLITE_OMIT_SHARED_CACHE) 

  20580. SQLITE_PRIVATE   void sqlite3VdbeEnter(Vdbe*);

  20581. #else

  20582. # define sqlite3VdbeEnter(X)

  20583. #endif

  20584. 

  20585. #if !defined(SQLITE_OMIT_SHARED_CACHE) && SQLITE_THREADSAFE>0

  20586. SQLITE_PRIVATE   void sqlite3VdbeLeave(Vdbe*);

  20587. #else

  20588. # define sqlite3VdbeLeave(X)

  20589. #endif

  20590. 

  20591. #ifdef SQLITE_DEBUG

  20592. SQLITE_PRIVATE void sqlite3VdbeMemAboutToChange(Vdbe*,Mem*);

  20593. SQLITE_PRIVATE int sqlite3VdbeCheckMemInvariants(Mem*);

  20594. #endif

  20595. 

  20596. #ifndef SQLITE_OMIT_FOREIGN_KEY

  20597. SQLITE_PRIVATE int sqlite3VdbeCheckFk(Vdbe *, int);

  20598. #else

  20599. # define sqlite3VdbeCheckFk(p,i) 0

  20600. #endif

  20601. 

  20602. #ifdef SQLITE_DEBUG

  20603. SQLITE_PRIVATE   void sqlite3VdbePrintSql(Vdbe*);

  20604. SQLITE_PRIVATE   void sqlite3VdbeMemPrettyPrint(Mem *pMem, char *zBuf);

  20605. #endif

  20606. #ifndef SQLITE_OMIT_UTF16

  20607. SQLITE_PRIVATE   int sqlite3VdbeMemTranslate(Mem*, u8);

  20608. SQLITE_PRIVATE   int sqlite3VdbeMemHandleBom(Mem *pMem);

  20609. #endif

  20610. 

  20611. #ifndef SQLITE_OMIT_INCRBLOB

  20612. SQLITE_PRIVATE   int sqlite3VdbeMemExpandBlob(Mem *);

  20613.   #define ExpandBlob(P) (((P)->flags&MEM_Zero)?sqlite3VdbeMemExpandBlob(P):0)

  20614. #else

  20615.   #define sqlite3VdbeMemExpandBlob(x) SQLITE_OK

  20616.   #define ExpandBlob(P) SQLITE_OK

  20617. #endif

  20618. 

  20619. #endif /* !defined(SQLITE_VDBEINT_H) */

  20620. 

  20621. /************** End of vdbeInt.h *********************************************/

  20622. /************** Continuing where we left off in status.c *********************/

  20623. 

  20624. /*

  20625. ** Variables in which to record status information.

  20626. */

  20627. #if SQLITE_PTRSIZE>4

  20628. typedef sqlite3_int64 sqlite3StatValueType;

  20629. #else

  20630. typedef u32 sqlite3StatValueType;

  20631. #endif

  20632. typedef struct sqlite3StatType sqlite3StatType;

  20633. static SQLITE_WSD struct sqlite3StatType {

  20634.   sqlite3StatValueType nowValue[10];  /* Current value */

  20635.   sqlite3StatValueType mxValue[10];   /* Maximum value */

  20636. } sqlite3Stat = { {0,}, {0,} };

  20637. 

  20638. /*

  20639. ** Elements of sqlite3Stat[] are protected by either the memory allocator

  20640. ** mutex, or by the pcache1 mutex.  The following array determines which.

  20641. */

  20642. static const char statMutex[] = {

  20643.   0,  /* SQLITE_STATUS_MEMORY_USED */

  20644.   1,  /* SQLITE_STATUS_PAGECACHE_USED */

  20645.   1,  /* SQLITE_STATUS_PAGECACHE_OVERFLOW */

  20646.   0,  /* SQLITE_STATUS_SCRATCH_USED */

  20647.   0,  /* SQLITE_STATUS_SCRATCH_OVERFLOW */

  20648.   0,  /* SQLITE_STATUS_MALLOC_SIZE */

  20649.   0,  /* SQLITE_STATUS_PARSER_STACK */

  20650.   1,  /* SQLITE_STATUS_PAGECACHE_SIZE */

  20651.   0,  /* SQLITE_STATUS_SCRATCH_SIZE */

  20652.   0,  /* SQLITE_STATUS_MALLOC_COUNT */

  20653. };

  20654. 

  20655. 

  20656. /* The "wsdStat" macro will resolve to the status information

  20657. ** state vector.  If writable static data is unsupported on the target,

  20658. ** we have to locate the state vector at run-time.  In the more common

  20659. ** case where writable static data is supported, wsdStat can refer directly

  20660. ** to the "sqlite3Stat" state vector declared above.

  20661. */

  20662. #ifdef SQLITE_OMIT_WSD

  20663. # define wsdStatInit  sqlite3StatType *x = &GLOBAL(sqlite3StatType,sqlite3Stat)

  20664. # define wsdStat x[0]

  20665. #else

  20666. # define wsdStatInit

  20667. # define wsdStat sqlite3Stat

  20668. #endif

  20669. 

  20670. /*

  20671. ** Return the current value of a status parameter.  The caller must

  20672. ** be holding the appropriate mutex.

  20673. */

  20674. SQLITE_PRIVATE sqlite3_int64 sqlite3StatusValue(int op){

  20675.   wsdStatInit;

  20676.   assert( op>=0 && op<ArraySize(wsdStat.nowValue) );

  20677.   assert( op>=0 && op<ArraySize(statMutex) );

  20678.   assert( sqlite3_mutex_held(statMutex[op] ? sqlite3Pcache1Mutex()

  20679.                                            : sqlite3MallocMutex()) );

  20680.   return wsdStat.nowValue[op];

  20681. }

  20682. 

  20683. /*

  20684. ** Add N to the value of a status record.  The caller must hold the

  20685. ** appropriate mutex.  (Locking is checked by assert()).

  20686. **

  20687. ** The StatusUp() routine can accept positive or negative values for N.

  20688. ** The value of N is added to the current status value and the high-water

  20689. ** mark is adjusted if necessary.

  20690. **

  20691. ** The StatusDown() routine lowers the current value by N.  The highwater

  20692. ** mark is unchanged.  N must be non-negative for StatusDown().

  20693. */

  20694. SQLITE_PRIVATE void sqlite3StatusUp(int op, int N){

  20695.   wsdStatInit;

  20696.   assert( op>=0 && op<ArraySize(wsdStat.nowValue) );

  20697.   assert( op>=0 && op<ArraySize(statMutex) );

  20698.   assert( sqlite3_mutex_held(statMutex[op] ? sqlite3Pcache1Mutex()

  20699.                                            : sqlite3MallocMutex()) );

  20700.   wsdStat.nowValue[op] += N;

  20701.   if( wsdStat.nowValue[op]>wsdStat.mxValue[op] ){

  20702.     wsdStat.mxValue[op] = wsdStat.nowValue[op];

  20703.   }

  20704. }

  20705. SQLITE_PRIVATE void sqlite3StatusDown(int op, int N){

  20706.   wsdStatInit;

  20707.   assert( N>=0 );

  20708.   assert( op>=0 && op<ArraySize(statMutex) );

  20709.   assert( sqlite3_mutex_held(statMutex[op] ? sqlite3Pcache1Mutex()

  20710.                                            : sqlite3MallocMutex()) );

  20711.   assert( op>=0 && op<ArraySize(wsdStat.nowValue) );

  20712.   wsdStat.nowValue[op] -= N;

  20713. }

  20714. 

  20715. /*

  20716. ** Adjust the highwater mark if necessary.

  20717. ** The caller must hold the appropriate mutex.

  20718. */

  20719. SQLITE_PRIVATE void sqlite3StatusHighwater(int op, int X){

  20720.   sqlite3StatValueType newValue;

  20721.   wsdStatInit;

  20722.   assert( X>=0 );

  20723.   newValue = (sqlite3StatValueType)X;

  20724.   assert( op>=0 && op<ArraySize(wsdStat.nowValue) );

  20725.   assert( op>=0 && op<ArraySize(statMutex) );

  20726.   assert( sqlite3_mutex_held(statMutex[op] ? sqlite3Pcache1Mutex()

  20727.                                            : sqlite3MallocMutex()) );

  20728.   assert( op==SQLITE_STATUS_MALLOC_SIZE

  20729.           || op==SQLITE_STATUS_PAGECACHE_SIZE

  20730.           || op==SQLITE_STATUS_PARSER_STACK );

  20731.   if( newValue>wsdStat.mxValue[op] ){

  20732.     wsdStat.mxValue[op] = newValue;

  20733.   }

  20734. }

  20735. 

  20736. /*

  20737. ** Query status information.

  20738. */

  20739. SQLITE_API int sqlite3_status64(

  20740.   int op,

  20741.   sqlite3_int64 *pCurrent,

  20742.   sqlite3_int64 *pHighwater,

  20743.   int resetFlag

  20744. ){

  20745.   sqlite3_mutex *pMutex;

  20746.   wsdStatInit;

  20747.   if( op<0 || op>=ArraySize(wsdStat.nowValue) ){

  20748.     return SQLITE_MISUSE_BKPT;

  20749.   }

  20750. #ifdef SQLITE_ENABLE_API_ARMOR

  20751.   if( pCurrent==0 || pHighwater==0 ) return SQLITE_MISUSE_BKPT;

  20752. #endif

  20753.   pMutex = statMutex[op] ? sqlite3Pcache1Mutex() : sqlite3MallocMutex();

  20754.   sqlite3_mutex_enter(pMutex);

  20755.   *pCurrent = wsdStat.nowValue[op];

  20756.   *pHighwater = wsdStat.mxValue[op];

  20757.   if( resetFlag ){

  20758.     wsdStat.mxValue[op] = wsdStat.nowValue[op];

  20759.   }

  20760.   sqlite3_mutex_leave(pMutex);

  20761.   (void)pMutex;  /* Prevent warning when SQLITE_THREADSAFE=0 */

  20762.   return SQLITE_OK;

  20763. }

  20764. SQLITE_API int sqlite3_status(int op, int *pCurrent, int *pHighwater, int resetFlag){

  20765.   sqlite3_int64 iCur = 0, iHwtr = 0;

  20766.   int rc;

  20767. #ifdef SQLITE_ENABLE_API_ARMOR

  20768.   if( pCurrent==0 || pHighwater==0 ) return SQLITE_MISUSE_BKPT;

  20769. #endif

  20770.   rc = sqlite3_status64(op, &iCur, &iHwtr, resetFlag);

  20771.   if( rc==0 ){

  20772.     *pCurrent = (int)iCur;

  20773.     *pHighwater = (int)iHwtr;

  20774.   }

  20775.   return rc;

  20776. }

  20777. 

  20778. /*

  20779. ** Return the number of LookasideSlot elements on the linked list

  20780. */

  20781. static u32 countLookasideSlots(LookasideSlot *p){

  20782.   u32 cnt = 0;

  20783.   while( p ){

  20784.     p = p->pNext;

  20785.     cnt++;

  20786.   }

  20787.   return cnt;

  20788. }

  20789. 

  20790. /*

  20791. ** Count the number of slots of lookaside memory that are outstanding

  20792. */

  20793. SQLITE_PRIVATE int sqlite3LookasideUsed(sqlite3 *db, int *pHighwater){

  20794.   u32 nInit = countLookasideSlots(db->lookaside.pInit);

  20795.   u32 nFree = countLookasideSlots(db->lookaside.pFree);

  20796.   if( pHighwater ) *pHighwater = db->lookaside.nSlot - nInit;

  20797.   return db->lookaside.nSlot - (nInit+nFree);

  20798. }

  20799. 

  20800. /*

  20801. ** Query status information for a single database connection

  20802. */

  20803. SQLITE_API int sqlite3_db_status(

  20804.   sqlite3 *db,          /* The database connection whose status is desired */

  20805.   int op,               /* Status verb */

  20806.   int *pCurrent,        /* Write current value here */

  20807.   int *pHighwater,      /* Write high-water mark here */

  20808.   int resetFlag         /* Reset high-water mark if true */

  20809. ){

  20810.   int rc = SQLITE_OK;   /* Return code */

  20811. #ifdef SQLITE_ENABLE_API_ARMOR

  20812.   if( !sqlite3SafetyCheckOk(db) || pCurrent==0|| pHighwater==0 ){

  20813.     return SQLITE_MISUSE_BKPT;

  20814.   }

  20815. #endif

  20816.   sqlite3_mutex_enter(db->mutex);

  20817.   switch( op ){

  20818.     case SQLITE_DBSTATUS_LOOKASIDE_USED: {

  20819.       *pCurrent = sqlite3LookasideUsed(db, pHighwater);

  20820.       if( resetFlag ){

  20821.         LookasideSlot *p = db->lookaside.pFree;

  20822.         if( p ){

  20823.           while( p->pNext ) p = p->pNext;

  20824.           p->pNext = db->lookaside.pInit;

  20825.           db->lookaside.pInit = db->lookaside.pFree;

  20826.           db->lookaside.pFree = 0;

  20827.         }

  20828.       }

  20829.       break;

  20830.     }

  20831. 

  20832.     case SQLITE_DBSTATUS_LOOKASIDE_HIT:

  20833.     case SQLITE_DBSTATUS_LOOKASIDE_MISS_SIZE:

  20834.     case SQLITE_DBSTATUS_LOOKASIDE_MISS_FULL: {

  20835.       testcase( op==SQLITE_DBSTATUS_LOOKASIDE_HIT );

  20836.       testcase( op==SQLITE_DBSTATUS_LOOKASIDE_MISS_SIZE );

  20837.       testcase( op==SQLITE_DBSTATUS_LOOKASIDE_MISS_FULL );

  20838.       assert( (op-SQLITE_DBSTATUS_LOOKASIDE_HIT)>=0 );

  20839.       assert( (op-SQLITE_DBSTATUS_LOOKASIDE_HIT)<3 );

  20840.       *pCurrent = 0;

  20841.       *pHighwater = db->lookaside.anStat[op - SQLITE_DBSTATUS_LOOKASIDE_HIT];

  20842.       if( resetFlag ){

  20843.         db->lookaside.anStat[op - SQLITE_DBSTATUS_LOOKASIDE_HIT] = 0;

  20844.       }

  20845.       break;

  20846.     }

  20847. 

  20848.     /* 

  20849.     ** Return an approximation for the amount of memory currently used

  20850.     ** by all pagers associated with the given database connection.  The

  20851.     ** highwater mark is meaningless and is returned as zero.

  20852.     */

  20853.     case SQLITE_DBSTATUS_CACHE_USED_SHARED:

  20854.     case SQLITE_DBSTATUS_CACHE_USED: {

  20855.       int totalUsed = 0;

  20856.       int i;

  20857.       sqlite3BtreeEnterAll(db);

  20858.       for(i=0; i<db->nDb; i++){

  20859.         Btree *pBt = db->aDb[i].pBt;

  20860.         if( pBt ){

  20861.           Pager *pPager = sqlite3BtreePager(pBt);

  20862.           int nByte = sqlite3PagerMemUsed(pPager);

  20863.           if( op==SQLITE_DBSTATUS_CACHE_USED_SHARED ){

  20864.             nByte = nByte / sqlite3BtreeConnectionCount(pBt);

  20865.           }

  20866.           totalUsed += nByte;

  20867.         }

  20868.       }

  20869.       sqlite3BtreeLeaveAll(db);

  20870.       *pCurrent = totalUsed;

  20871.       *pHighwater = 0;

  20872.       break;

  20873.     }

  20874. 

  20875.     /*

  20876.     ** *pCurrent gets an accurate estimate of the amount of memory used

  20877.     ** to store the schema for all databases (main, temp, and any ATTACHed

  20878.     ** databases.  *pHighwater is set to zero.

  20879.     */

  20880.     case SQLITE_DBSTATUS_SCHEMA_USED: {

  20881.       int i;                      /* Used to iterate through schemas */

  20882.       int nByte = 0;              /* Used to accumulate return value */

  20883. 

  20884.       sqlite3BtreeEnterAll(db);

  20885.       db->pnBytesFreed = &nByte;

  20886.       for(i=0; i<db->nDb; i++){

  20887.         Schema *pSchema = db->aDb[i].pSchema;

  20888.         if( ALWAYS(pSchema!=0) ){

  20889.           HashElem *p;

  20890. 

  20891.           nByte += sqlite3GlobalConfig.m.xRoundup(sizeof(HashElem)) * (

  20892.               pSchema->tblHash.count 

  20893.             + pSchema->trigHash.count

  20894.             + pSchema->idxHash.count

  20895.             + pSchema->fkeyHash.count

  20896.           );

  20897.           nByte += sqlite3_msize(pSchema->tblHash.ht);

  20898.           nByte += sqlite3_msize(pSchema->trigHash.ht);

  20899.           nByte += sqlite3_msize(pSchema->idxHash.ht);

  20900.           nByte += sqlite3_msize(pSchema->fkeyHash.ht);

  20901. 

  20902.           for(p=sqliteHashFirst(&pSchema->trigHash); p; p=sqliteHashNext(p)){

  20903.             sqlite3DeleteTrigger(db, (Trigger*)sqliteHashData(p));

  20904.           }

  20905.           for(p=sqliteHashFirst(&pSchema->tblHash); p; p=sqliteHashNext(p)){

  20906.             sqlite3DeleteTable(db, (Table *)sqliteHashData(p));

  20907.           }

  20908.         }

  20909.       }

  20910.       db->pnBytesFreed = 0;

  20911.       sqlite3BtreeLeaveAll(db);

  20912. 

  20913.       *pHighwater = 0;

  20914.       *pCurrent = nByte;

  20915.       break;

  20916.     }

  20917. 

  20918.     /*

  20919.     ** *pCurrent gets an accurate estimate of the amount of memory used

  20920.     ** to store all prepared statements.

  20921.     ** *pHighwater is set to zero.

  20922.     */

  20923.     case SQLITE_DBSTATUS_STMT_USED: {

  20924.       struct Vdbe *pVdbe;         /* Used to iterate through VMs */

  20925.       int nByte = 0;              /* Used to accumulate return value */

  20926. 

  20927.       db->pnBytesFreed = &nByte;

  20928.       for(pVdbe=db->pVdbe; pVdbe; pVdbe=pVdbe->pNext){

  20929.         sqlite3VdbeClearObject(db, pVdbe);

  20930.         sqlite3DbFree(db, pVdbe);

  20931.       }

  20932.       db->pnBytesFreed = 0;

  20933. 

  20934.       *pHighwater = 0;  /* IMP: R-64479-57858 */

  20935.       *pCurrent = nByte;

  20936. 

  20937.       break;

  20938.     }

  20939. 

  20940.     /*

  20941.     ** Set *pCurrent to the total cache hits or misses encountered by all

  20942.     ** pagers the database handle is connected to. *pHighwater is always set 

  20943.     ** to zero.

  20944.     */

  20945.     case SQLITE_DBSTATUS_CACHE_SPILL:

  20946.       op = SQLITE_DBSTATUS_CACHE_WRITE+1;

  20947.       /* Fall through into the next case */

  20948.     case SQLITE_DBSTATUS_CACHE_HIT:

  20949.     case SQLITE_DBSTATUS_CACHE_MISS:

  20950.     case SQLITE_DBSTATUS_CACHE_WRITE:{

  20951.       int i;

  20952.       int nRet = 0;

  20953.       assert( SQLITE_DBSTATUS_CACHE_MISS==SQLITE_DBSTATUS_CACHE_HIT+1 );

  20954.       assert( SQLITE_DBSTATUS_CACHE_WRITE==SQLITE_DBSTATUS_CACHE_HIT+2 );

  20955. 

  20956.       for(i=0; i<db->nDb; i++){

  20957.         if( db->aDb[i].pBt ){

  20958.           Pager *pPager = sqlite3BtreePager(db->aDb[i].pBt);

  20959.           sqlite3PagerCacheStat(pPager, op, resetFlag, &nRet);

  20960.         }

  20961.       }

  20962.       *pHighwater = 0; /* IMP: R-42420-56072 */

  20963.                        /* IMP: R-54100-20147 */

  20964.                        /* IMP: R-29431-39229 */

  20965.       *pCurrent = nRet;

  20966.       break;

  20967.     }

  20968. 

  20969.     /* Set *pCurrent to non-zero if there are unresolved deferred foreign

  20970.     ** key constraints.  Set *pCurrent to zero if all foreign key constraints

  20971.     ** have been satisfied.  The *pHighwater is always set to zero.

  20972.     */

  20973.     case SQLITE_DBSTATUS_DEFERRED_FKS: {

  20974.       *pHighwater = 0;  /* IMP: R-11967-56545 */

  20975.       *pCurrent = db->nDeferredImmCons>0 || db->nDeferredCons>0;

  20976.       break;

  20977.     }

  20978. 

  20979.     default: {

  20980.       rc = SQLITE_ERROR;

  20981.     }

  20982.   }

  20983.   sqlite3_mutex_leave(db->mutex);

  20984.   return rc;

  20985. }

  20986. 

  20987. /************** End of status.c **********************************************/

  20988. /************** Begin file date.c ********************************************/

  20989. /*

  20990. ** 2003 October 31

  20991. **

  20992. ** The author disclaims copyright to this source code.  In place of

  20993. ** a legal notice, here is a blessing:

  20994. **

  20995. **    May you do good and not evil.

  20996. **    May you find forgiveness for yourself and forgive others.

  20997. **    May you share freely, never taking more than you give.

  20998. **

  20999. *************************************************************************

  21000. ** This file contains the C functions that implement date and time

  21001. ** functions for SQLite.  

  21002. **

  21003. ** There is only one exported symbol in this file - the function

  21004. ** sqlite3RegisterDateTimeFunctions() found at the bottom of the file.

  21005. ** All other code has file scope.

  21006. **

  21007. ** SQLite processes all times and dates as julian day numbers.  The

  21008. ** dates and times are stored as the number of days since noon

  21009. ** in Greenwich on November 24, 4714 B.C. according to the Gregorian

  21010. ** calendar system. 

  21011. **

  21012. ** 1970-01-01 00:00:00 is JD 2440587.5

  21013. ** 2000-01-01 00:00:00 is JD 2451544.5

  21014. **

  21015. ** This implementation requires years to be expressed as a 4-digit number

  21016. ** which means that only dates between 0000-01-01 and 9999-12-31 can

  21017. ** be represented, even though julian day numbers allow a much wider

  21018. ** range of dates.

  21019. **

  21020. ** The Gregorian calendar system is used for all dates and times,

  21021. ** even those that predate the Gregorian calendar.  Historians usually

  21022. ** use the julian calendar for dates prior to 1582-10-15 and for some

  21023. ** dates afterwards, depending on locale.  Beware of this difference.

  21024. **

  21025. ** The conversion algorithms are implemented based on descriptions

  21026. ** in the following text:

  21027. **

  21028. **      Jean Meeus

  21029. **      Astronomical Algorithms, 2nd Edition, 1998

  21030. **      ISBN 0-943396-61-1

  21031. **      Willmann-Bell, Inc

  21032. **      Richmond, Virginia (USA)

  21033. */

  21034. /* #include "sqliteInt.h" */

  21035. /* #include <stdlib.h> */

  21036. /* #include <assert.h> */

  21037. #include <time.h>

  21038. 

  21039. #ifndef SQLITE_OMIT_DATETIME_FUNCS

  21040. 

  21041. /*

  21042. ** The MSVC CRT on Windows CE may not have a localtime() function.

  21043. ** So declare a substitute.  The substitute function itself is

  21044. ** defined in "os_win.c".

  21045. */

  21046. #if !defined(SQLITE_OMIT_LOCALTIME) && defined(_WIN32_WCE) && \

  21047.     (!defined(SQLITE_MSVC_LOCALTIME_API) || !SQLITE_MSVC_LOCALTIME_API)

  21048. struct tm *__cdecl localtime(const time_t *);

  21049. #endif

  21050. 

  21051. /*

  21052. ** A structure for holding a single date and time.

  21053. */

  21054. typedef struct DateTime DateTime;

  21055. struct DateTime {

  21056.   sqlite3_int64 iJD;  /* The julian day number times 86400000 */

  21057.   int Y, M, D;        /* Year, month, and day */

  21058.   int h, m;           /* Hour and minutes */

  21059.   int tz;             /* Timezone offset in minutes */

  21060.   double s;           /* Seconds */

  21061.   char validJD;       /* True (1) if iJD is valid */

  21062.   char rawS;          /* Raw numeric value stored in s */

  21063.   char validYMD;      /* True (1) if Y,M,D are valid */

  21064.   char validHMS;      /* True (1) if h,m,s are valid */

  21065.   char validTZ;       /* True (1) if tz is valid */

  21066.   char tzSet;         /* Timezone was set explicitly */

  21067.   char isError;       /* An overflow has occurred */

  21068. };

  21069. 

  21070. 

  21071. /*

  21072. ** Convert zDate into one or more integers according to the conversion

  21073. ** specifier zFormat.

  21074. **

  21075. ** zFormat[] contains 4 characters for each integer converted, except for

  21076. ** the last integer which is specified by three characters.  The meaning

  21077. ** of a four-character format specifiers ABCD is:

  21078. **

  21079. **    A:   number of digits to convert.  Always "2" or "4".

  21080. **    B:   minimum value.  Always "0" or "1".

  21081. **    C:   maximum value, decoded as:

  21082. **           a:  12

  21083. **           b:  14

  21084. **           c:  24

  21085. **           d:  31

  21086. **           e:  59

  21087. **           f:  9999

  21088. **    D:   the separator character, or \000 to indicate this is the

  21089. **         last number to convert.

  21090. **

  21091. ** Example:  To translate an ISO-8601 date YYYY-MM-DD, the format would

  21092. ** be "40f-21a-20c".  The "40f-" indicates the 4-digit year followed by "-".

  21093. ** The "21a-" indicates the 2-digit month followed by "-".  The "20c" indicates

  21094. ** the 2-digit day which is the last integer in the set.

  21095. **

  21096. ** The function returns the number of successful conversions.

  21097. */

  21098. static int getDigits(const char *zDate, const char *zFormat, ...){

  21099.   /* The aMx[] array translates the 3rd character of each format

  21100.   ** spec into a max size:    a   b   c   d   e     f */

  21101.   static const u16 aMx[] = { 12, 14, 24, 31, 59, 9999 };

  21102.   va_list ap;

  21103.   int cnt = 0;

  21104.   char nextC;

  21105.   va_start(ap, zFormat);

  21106.   do{

  21107.     char N = zFormat[0] - '0';

  21108.     char min = zFormat[1] - '0';

  21109.     int val = 0;

  21110.     u16 max;

  21111. 

  21112.     assert( zFormat[2]>='a' && zFormat[2]<='f' );

  21113.     max = aMx[zFormat[2] - 'a'];

  21114.     nextC = zFormat[3];

  21115.     val = 0;

  21116.     while( N-- ){

  21117.       if( !sqlite3Isdigit(*zDate) ){

  21118.         goto end_getDigits;

  21119.       }

  21120.       val = val*10 + *zDate - '0';

  21121.       zDate++;

  21122.     }

  21123.     if( val<(int)min || val>(int)max || (nextC!=0 && nextC!=*zDate) ){

  21124.       goto end_getDigits;

  21125.     }

  21126.     *va_arg(ap,int*) = val;

  21127.     zDate++;

  21128.     cnt++;

  21129.     zFormat += 4;

  21130.   }while( nextC );

  21131. end_getDigits:

  21132.   va_end(ap);

  21133.   return cnt;

  21134. }

  21135. 

  21136. /*

  21137. ** Parse a timezone extension on the end of a date-time.

  21138. ** The extension is of the form:

  21139. **

  21140. **        (+/-)HH:MM

  21141. **

  21142. ** Or the "zulu" notation:

  21143. **

  21144. **        Z

  21145. **

  21146. ** If the parse is successful, write the number of minutes

  21147. ** of change in p->tz and return 0.  If a parser error occurs,

  21148. ** return non-zero.

  21149. **

  21150. ** A missing specifier is not considered an error.

  21151. */

  21152. static int parseTimezone(const char *zDate, DateTime *p){

  21153.   int sgn = 0;

  21154.   int nHr, nMn;

  21155.   int c;

  21156.   while( sqlite3Isspace(*zDate) ){ zDate++; }

  21157.   p->tz = 0;

  21158.   c = *zDate;

  21159.   if( c=='-' ){

  21160.     sgn = -1;

  21161.   }else if( c=='+' ){

  21162.     sgn = +1;

  21163.   }else if( c=='Z' || c=='z' ){

  21164.     zDate++;

  21165.     goto zulu_time;

  21166.   }else{

  21167.     return c!=0;

  21168.   }

  21169.   zDate++;

  21170.   if( getDigits(zDate, "20b:20e", &nHr, &nMn)!=2 ){

  21171.     return 1;

  21172.   }

  21173.   zDate += 5;

  21174.   p->tz = sgn*(nMn + nHr*60);

  21175. zulu_time:

  21176.   while( sqlite3Isspace(*zDate) ){ zDate++; }

  21177.   p->tzSet = 1;

  21178.   return *zDate!=0;

  21179. }

  21180. 

  21181. /*

  21182. ** Parse times of the form HH:MM or HH:MM:SS or HH:MM:SS.FFFF.

  21183. ** The HH, MM, and SS must each be exactly 2 digits.  The

  21184. ** fractional seconds FFFF can be one or more digits.

  21185. **

  21186. ** Return 1 if there is a parsing error and 0 on success.

  21187. */

  21188. static int parseHhMmSs(const char *zDate, DateTime *p){

  21189.   int h, m, s;

  21190.   double ms = 0.0;

  21191.   if( getDigits(zDate, "20c:20e", &h, &m)!=2 ){

  21192.     return 1;

  21193.   }

  21194.   zDate += 5;

  21195.   if( *zDate==':' ){

  21196.     zDate++;

  21197.     if( getDigits(zDate, "20e", &s)!=1 ){

  21198.       return 1;

  21199.     }

  21200.     zDate += 2;

  21201.     if( *zDate=='.' && sqlite3Isdigit(zDate[1]) ){

  21202.       double rScale = 1.0;

  21203.       zDate++;

  21204.       while( sqlite3Isdigit(*zDate) ){

  21205.         ms = ms*10.0 + *zDate - '0';

  21206.         rScale *= 10.0;

  21207.         zDate++;

  21208.       }

  21209.       ms /= rScale;

  21210.     }

  21211.   }else{

  21212.     s = 0;

  21213.   }

  21214.   p->validJD = 0;

  21215.   p->rawS = 0;

  21216.   p->validHMS = 1;

  21217.   p->h = h;

  21218.   p->m = m;

  21219.   p->s = s + ms;

  21220.   if( parseTimezone(zDate, p) ) return 1;

  21221.   p->validTZ = (p->tz!=0)?1:0;

  21222.   return 0;

  21223. }

  21224. 

  21225. /*

  21226. ** Put the DateTime object into its error state.

  21227. */

  21228. static void datetimeError(DateTime *p){

  21229.   memset(p, 0, sizeof(*p));

  21230.   p->isError = 1;

  21231. }

  21232. 

  21233. /*

  21234. ** Convert from YYYY-MM-DD HH:MM:SS to julian day.  We always assume

  21235. ** that the YYYY-MM-DD is according to the Gregorian calendar.

  21236. **

  21237. ** Reference:  Meeus page 61

  21238. */

  21239. static void computeJD(DateTime *p){

  21240.   int Y, M, D, A, B, X1, X2;

  21241. 

  21242.   if( p->validJD ) return;

  21243.   if( p->validYMD ){

  21244.     Y = p->Y;

  21245.     M = p->M;

  21246.     D = p->D;

  21247.   }else{

  21248.     Y = 2000;  /* If no YMD specified, assume 2000-Jan-01 */

  21249.     M = 1;

  21250.     D = 1;

  21251.   }

  21252.   if( Y<-4713 || Y>9999 || p->rawS ){

  21253.     datetimeError(p);

  21254.     return;

  21255.   }

  21256.   if( M<=2 ){

  21257.     Y--;

  21258.     M += 12;

  21259.   }

  21260.   A = Y/100;

  21261.   B = 2 - A + (A/4);

  21262.   X1 = 36525*(Y+4716)/100;

  21263.   X2 = 306001*(M+1)/10000;

  21264.   p->iJD = (sqlite3_int64)((X1 + X2 + D + B - 1524.5 ) * 86400000);

  21265.   p->validJD = 1;

  21266.   if( p->validHMS ){

  21267.     p->iJD += p->h*3600000 + p->m*60000 + (sqlite3_int64)(p->s*1000);

  21268.     if( p->validTZ ){

  21269.       p->iJD -= p->tz*60000;

  21270.       p->validYMD = 0;

  21271.       p->validHMS = 0;

  21272.       p->validTZ = 0;

  21273.     }

  21274.   }

  21275. }

  21276. 

  21277. /*

  21278. ** Parse dates of the form

  21279. **

  21280. **     YYYY-MM-DD HH:MM:SS.FFF

  21281. **     YYYY-MM-DD HH:MM:SS

  21282. **     YYYY-MM-DD HH:MM

  21283. **     YYYY-MM-DD

  21284. **

  21285. ** Write the result into the DateTime structure and return 0

  21286. ** on success and 1 if the input string is not a well-formed

  21287. ** date.

  21288. */

  21289. static int parseYyyyMmDd(const char *zDate, DateTime *p){

  21290.   int Y, M, D, neg;

  21291. 

  21292.   if( zDate[0]=='-' ){

  21293.     zDate++;

  21294.     neg = 1;

  21295.   }else{

  21296.     neg = 0;

  21297.   }

  21298.   if( getDigits(zDate, "40f-21a-21d", &Y, &M, &D)!=3 ){

  21299.     return 1;

  21300.   }

  21301.   zDate += 10;

  21302.   while( sqlite3Isspace(*zDate) || 'T'==*(u8*)zDate ){ zDate++; }

  21303.   if( parseHhMmSs(zDate, p)==0 ){

  21304.     /* We got the time */

  21305.   }else if( *zDate==0 ){

  21306.     p->validHMS = 0;

  21307.   }else{

  21308.     return 1;

  21309.   }

  21310.   p->validJD = 0;

  21311.   p->validYMD = 1;

  21312.   p->Y = neg ? -Y : Y;

  21313.   p->M = M;

  21314.   p->D = D;

  21315.   if( p->validTZ ){

  21316.     computeJD(p);

  21317.   }

  21318.   return 0;

  21319. }

  21320. 

  21321. /*

  21322. ** Set the time to the current time reported by the VFS.

  21323. **

  21324. ** Return the number of errors.

  21325. */

  21326. static int setDateTimeToCurrent(sqlite3_context *context, DateTime *p){

  21327.   p->iJD = sqlite3StmtCurrentTime(context);

  21328.   if( p->iJD>0 ){

  21329.     p->validJD = 1;

  21330.     return 0;

  21331.   }else{

  21332.     return 1;

  21333.   }

  21334. }

  21335. 

  21336. /*

  21337. ** Input "r" is a numeric quantity which might be a julian day number,

  21338. ** or the number of seconds since 1970.  If the value if r is within

  21339. ** range of a julian day number, install it as such and set validJD.

  21340. ** If the value is a valid unix timestamp, put it in p->s and set p->rawS.

  21341. */

  21342. static void setRawDateNumber(DateTime *p, double r){

  21343.   p->s = r;

  21344.   p->rawS = 1;

  21345.   if( r>=0.0 && r<5373484.5 ){

  21346.     p->iJD = (sqlite3_int64)(r*86400000.0 + 0.5);

  21347.     p->validJD = 1;

  21348.   }

  21349. }

  21350. 

  21351. /*

  21352. ** Attempt to parse the given string into a julian day number.  Return

  21353. ** the number of errors.

  21354. **

  21355. ** The following are acceptable forms for the input string:

  21356. **

  21357. **      YYYY-MM-DD HH:MM:SS.FFF  +/-HH:MM

  21358. **      DDDD.DD 

  21359. **      now

  21360. **

  21361. ** In the first form, the +/-HH:MM is always optional.  The fractional

  21362. ** seconds extension (the ".FFF") is optional.  The seconds portion

  21363. ** (":SS.FFF") is option.  The year and date can be omitted as long

  21364. ** as there is a time string.  The time string can be omitted as long

  21365. ** as there is a year and date.

  21366. */

  21367. static int parseDateOrTime(

  21368.   sqlite3_context *context, 

  21369.   const char *zDate, 

  21370.   DateTime *p

  21371. ){

  21372.   double r;

  21373.   if( parseYyyyMmDd(zDate,p)==0 ){

  21374.     return 0;

  21375.   }else if( parseHhMmSs(zDate, p)==0 ){

  21376.     return 0;

  21377.   }else if( sqlite3StrICmp(zDate,"now")==0 && sqlite3NotPureFunc(context) ){

  21378.     return setDateTimeToCurrent(context, p);

  21379.   }else if( sqlite3AtoF(zDate, &r, sqlite3Strlen30(zDate), SQLITE_UTF8)>0 ){

  21380.     setRawDateNumber(p, r);

  21381.     return 0;

  21382.   }

  21383.   return 1;

  21384. }

  21385. 

  21386. /* The julian day number for 9999-12-31 23:59:59.999 is 5373484.4999999.

  21387. ** Multiplying this by 86400000 gives 464269060799999 as the maximum value

  21388. ** for DateTime.iJD.

  21389. **

  21390. ** But some older compilers (ex: gcc 4.2.1 on older Macs) cannot deal with 

  21391. ** such a large integer literal, so we have to encode it.

  21392. */

  21393. #define INT_464269060799999  ((((i64)0x1a640)<<32)|0x1072fdff)

  21394. 

  21395. /*

  21396. ** Return TRUE if the given julian day number is within range.

  21397. **

  21398. ** The input is the JulianDay times 86400000.

  21399. */

  21400. static int validJulianDay(sqlite3_int64 iJD){

  21401.   return iJD>=0 && iJD<=INT_464269060799999;

  21402. }

  21403. 

  21404. /*

  21405. ** Compute the Year, Month, and Day from the julian day number.

  21406. */

  21407. static void computeYMD(DateTime *p){

  21408.   int Z, A, B, C, D, E, X1;

  21409.   if( p->validYMD ) return;

  21410.   if( !p->validJD ){

  21411.     p->Y = 2000;

  21412.     p->M = 1;

  21413.     p->D = 1;

  21414.   }else if( !validJulianDay(p->iJD) ){

  21415.     datetimeError(p);

  21416.     return;

  21417.   }else{

  21418.     Z = (int)((p->iJD + 43200000)/86400000);

  21419.     A = (int)((Z - 1867216.25)/36524.25);

  21420.     A = Z + 1 + A - (A/4);

  21421.     B = A + 1524;

  21422.     C = (int)((B - 122.1)/365.25);

  21423.     D = (36525*(C&32767))/100;

  21424.     E = (int)((B-D)/30.6001);

  21425.     X1 = (int)(30.6001*E);

  21426.     p->D = B - D - X1;

  21427.     p->M = E<14 ? E-1 : E-13;

  21428.     p->Y = p->M>2 ? C - 4716 : C - 4715;

  21429.   }

  21430.   p->validYMD = 1;

  21431. }

  21432. 

  21433. /*

  21434. ** Compute the Hour, Minute, and Seconds from the julian day number.

  21435. */

  21436. static void computeHMS(DateTime *p){

  21437.   int s;

  21438.   if( p->validHMS ) return;

  21439.   computeJD(p);

  21440.   s = (int)((p->iJD + 43200000) % 86400000);

  21441.   p->s = s/1000.0;

  21442.   s = (int)p->s;

  21443.   p->s -= s;

  21444.   p->h = s/3600;

  21445.   s -= p->h*3600;

  21446.   p->m = s/60;

  21447.   p->s += s - p->m*60;

  21448.   p->rawS = 0;

  21449.   p->validHMS = 1;

  21450. }

  21451. 

  21452. /*

  21453. ** Compute both YMD and HMS

  21454. */

  21455. static void computeYMD_HMS(DateTime *p){

  21456.   computeYMD(p);

  21457.   computeHMS(p);

  21458. }

  21459. 

  21460. /*

  21461. ** Clear the YMD and HMS and the TZ

  21462. */

  21463. static void clearYMD_HMS_TZ(DateTime *p){

  21464.   p->validYMD = 0;

  21465.   p->validHMS = 0;

  21466.   p->validTZ = 0;

  21467. }

  21468. 

  21469. #ifndef SQLITE_OMIT_LOCALTIME

  21470. /*

  21471. ** On recent Windows platforms, the localtime_s() function is available

  21472. ** as part of the "Secure CRT". It is essentially equivalent to 

  21473. ** localtime_r() available under most POSIX platforms, except that the 

  21474. ** order of the parameters is reversed.

  21475. **

  21476. ** See http://msdn.microsoft.com/en-us/library/a442x3ye(VS.80).aspx.

  21477. **

  21478. ** If the user has not indicated to use localtime_r() or localtime_s()

  21479. ** already, check for an MSVC build environment that provides 

  21480. ** localtime_s().

  21481. */

  21482. #if !HAVE_LOCALTIME_R && !HAVE_LOCALTIME_S \

  21483.     && defined(_MSC_VER) && defined(_CRT_INSECURE_DEPRECATE)

  21484. #undef  HAVE_LOCALTIME_S

  21485. #define HAVE_LOCALTIME_S 1

  21486. #endif

  21487. 

  21488. /*

  21489. ** The following routine implements the rough equivalent of localtime_r()

  21490. ** using whatever operating-system specific localtime facility that

  21491. ** is available.  This routine returns 0 on success and

  21492. ** non-zero on any kind of error.

  21493. **

  21494. ** If the sqlite3GlobalConfig.bLocaltimeFault variable is true then this

  21495. ** routine will always fail.

  21496. **

  21497. ** EVIDENCE-OF: R-62172-00036 In this implementation, the standard C

  21498. ** library function localtime_r() is used to assist in the calculation of

  21499. ** local time.

  21500. */

  21501. static int osLocaltime(time_t *t, struct tm *pTm){

  21502.   int rc;

  21503. #if !HAVE_LOCALTIME_R && !HAVE_LOCALTIME_S

  21504.   struct tm *pX;

  21505. #if SQLITE_THREADSAFE>0

  21506.   sqlite3_mutex *mutex = sqlite3MutexAlloc(SQLITE_MUTEX_STATIC_MASTER);

  21507. #endif

  21508.   sqlite3_mutex_enter(mutex);

  21509.   pX = localtime(t);

  21510. #ifndef SQLITE_UNTESTABLE

  21511.   if( sqlite3GlobalConfig.bLocaltimeFault ) pX = 0;

  21512. #endif

  21513.   if( pX ) *pTm = *pX;

  21514.   sqlite3_mutex_leave(mutex);

  21515.   rc = pX==0;

  21516. #else

  21517. #ifndef SQLITE_UNTESTABLE

  21518.   if( sqlite3GlobalConfig.bLocaltimeFault ) return 1;

  21519. #endif

  21520. #if HAVE_LOCALTIME_R

  21521.   rc = localtime_r(t, pTm)==0;

  21522. #else

  21523.   rc = localtime_s(pTm, t);

  21524. #endif /* HAVE_LOCALTIME_R */

  21525. #endif /* HAVE_LOCALTIME_R || HAVE_LOCALTIME_S */

  21526.   return rc;

  21527. }

  21528. #endif /* SQLITE_OMIT_LOCALTIME */

  21529. 

  21530. 

  21531. #ifndef SQLITE_OMIT_LOCALTIME

  21532. /*

  21533. ** Compute the difference (in milliseconds) between localtime and UTC

  21534. ** (a.k.a. GMT) for the time value p where p is in UTC. If no error occurs,

  21535. ** return this value and set *pRc to SQLITE_OK. 

  21536. **

  21537. ** Or, if an error does occur, set *pRc to SQLITE_ERROR. The returned value

  21538. ** is undefined in this case.

  21539. */

  21540. static sqlite3_int64 localtimeOffset(

  21541.   DateTime *p,                    /* Date at which to calculate offset */

  21542.   sqlite3_context *pCtx,          /* Write error here if one occurs */

  21543.   int *pRc                        /* OUT: Error code. SQLITE_OK or ERROR */

  21544. ){

  21545.   DateTime x, y;

  21546.   time_t t;

  21547.   struct tm sLocal;

  21548. 

  21549.   /* Initialize the contents of sLocal to avoid a compiler warning. */

  21550.   memset(&sLocal, 0, sizeof(sLocal));

  21551. 

  21552.   x = *p;

  21553.   computeYMD_HMS(&x);

  21554.   if( x.Y<1971 || x.Y>=2038 ){

  21555.     /* EVIDENCE-OF: R-55269-29598 The localtime_r() C function normally only

  21556.     ** works for years between 1970 and 2037. For dates outside this range,

  21557.     ** SQLite attempts to map the year into an equivalent year within this

  21558.     ** range, do the calculation, then map the year back.

  21559.     */

  21560.     x.Y = 2000;

  21561.     x.M = 1;

  21562.     x.D = 1;

  21563.     x.h = 0;

  21564.     x.m = 0;

  21565.     x.s = 0.0;

  21566.   } else {

  21567.     int s = (int)(x.s + 0.5);

  21568.     x.s = s;

  21569.   }

  21570.   x.tz = 0;

  21571.   x.validJD = 0;

  21572.   computeJD(&x);

  21573.   t = (time_t)(x.iJD/1000 - 21086676*(i64)10000);

  21574.   if( osLocaltime(&t, &sLocal) ){

  21575.     sqlite3_result_error(pCtx, "local time unavailable", -1);

  21576.     *pRc = SQLITE_ERROR;

  21577.     return 0;

  21578.   }

  21579.   y.Y = sLocal.tm_year + 1900;

  21580.   y.M = sLocal.tm_mon + 1;

  21581.   y.D = sLocal.tm_mday;

  21582.   y.h = sLocal.tm_hour;

  21583.   y.m = sLocal.tm_min;

  21584.   y.s = sLocal.tm_sec;

  21585.   y.validYMD = 1;

  21586.   y.validHMS = 1;

  21587.   y.validJD = 0;

  21588.   y.rawS = 0;

  21589.   y.validTZ = 0;

  21590.   y.isError = 0;

  21591.   computeJD(&y);

  21592.   *pRc = SQLITE_OK;

  21593.   return y.iJD - x.iJD;

  21594. }

  21595. #endif /* SQLITE_OMIT_LOCALTIME */

  21596. 

  21597. /*

  21598. ** The following table defines various date transformations of the form

  21599. **

  21600. **            'NNN days'

  21601. **

  21602. ** Where NNN is an arbitrary floating-point number and "days" can be one

  21603. ** of several units of time.

  21604. */

  21605. static const struct {

  21606.   u8 eType;           /* Transformation type code */

  21607.   u8 nName;           /* Length of th name */

  21608.   char *zName;        /* Name of the transformation */

  21609.   double rLimit;      /* Maximum NNN value for this transform */

  21610.   double rXform;      /* Constant used for this transform */

  21611. } aXformType[] = {

  21612.   { 0, 6, "second", 464269060800.0, 86400000.0/(24.0*60.0*60.0) },

  21613.   { 0, 6, "minute", 7737817680.0,   86400000.0/(24.0*60.0)      },

  21614.   { 0, 4, "hour",   128963628.0,    86400000.0/24.0             },

  21615.   { 0, 3, "day",    5373485.0,      86400000.0                  },

  21616.   { 1, 5, "month",  176546.0,       30.0*86400000.0             },

  21617.   { 2, 4, "year",   14713.0,        365.0*86400000.0            },

  21618. };

  21619. 

  21620. /*

  21621. ** Process a modifier to a date-time stamp.  The modifiers are

  21622. ** as follows:

  21623. **

  21624. **     NNN days

  21625. **     NNN hours

  21626. **     NNN minutes

  21627. **     NNN.NNNN seconds

  21628. **     NNN months

  21629. **     NNN years

  21630. **     start of month

  21631. **     start of year

  21632. **     start of week

  21633. **     start of day

  21634. **     weekday N

  21635. **     unixepoch

  21636. **     localtime

  21637. **     utc

  21638. **

  21639. ** Return 0 on success and 1 if there is any kind of error. If the error

  21640. ** is in a system call (i.e. localtime()), then an error message is written

  21641. ** to context pCtx. If the error is an unrecognized modifier, no error is

  21642. ** written to pCtx.

  21643. */

  21644. static int parseModifier(

  21645.   sqlite3_context *pCtx,      /* Function context */

  21646.   const char *z,              /* The text of the modifier */

  21647.   int n,                      /* Length of zMod in bytes */

  21648.   DateTime *p                 /* The date/time value to be modified */

  21649. ){

  21650.   int rc = 1;

  21651.   double r;

  21652.   switch(sqlite3UpperToLower[(u8)z[0]] ){

  21653. #ifndef SQLITE_OMIT_LOCALTIME

  21654.     case 'l': {

  21655.       /*    localtime

  21656.       **

  21657.       ** Assuming the current time value is UTC (a.k.a. GMT), shift it to

  21658.       ** show local time.

  21659.       */

  21660.       if( sqlite3_stricmp(z, "localtime")==0 && sqlite3NotPureFunc(pCtx) ){

  21661.         computeJD(p);

  21662.         p->iJD += localtimeOffset(p, pCtx, &rc);

  21663.         clearYMD_HMS_TZ(p);

  21664.       }

  21665.       break;

  21666.     }

  21667. #endif

  21668.     case 'u': {

  21669.       /*

  21670.       **    unixepoch

  21671.       **

  21672.       ** Treat the current value of p->s as the number of

  21673.       ** seconds since 1970.  Convert to a real julian day number.

  21674.       */

  21675.       if( sqlite3_stricmp(z, "unixepoch")==0 && p->rawS ){

  21676.         r = p->s*1000.0 + 210866760000000.0;

  21677.         if( r>=0.0 && r<464269060800000.0 ){

  21678.           clearYMD_HMS_TZ(p);

  21679.           p->iJD = (sqlite3_int64)r;

  21680.           p->validJD = 1;

  21681.           p->rawS = 0;

  21682.           rc = 0;

  21683.         }

  21684.       }

  21685. #ifndef SQLITE_OMIT_LOCALTIME

  21686.       else if( sqlite3_stricmp(z, "utc")==0 && sqlite3NotPureFunc(pCtx) ){

  21687.         if( p->tzSet==0 ){

  21688.           sqlite3_int64 c1;

  21689.           computeJD(p);

  21690.           c1 = localtimeOffset(p, pCtx, &rc);

  21691.           if( rc==SQLITE_OK ){

  21692.             p->iJD -= c1;

  21693.             clearYMD_HMS_TZ(p);

  21694.             p->iJD += c1 - localtimeOffset(p, pCtx, &rc);

  21695.           }

  21696.           p->tzSet = 1;

  21697.         }else{

  21698.           rc = SQLITE_OK;

  21699.         }

  21700.       }

  21701. #endif

  21702.       break;

  21703.     }

  21704.     case 'w': {

  21705.       /*

  21706.       **    weekday N

  21707.       **

  21708.       ** Move the date to the same time on the next occurrence of

  21709.       ** weekday N where 0==Sunday, 1==Monday, and so forth.  If the

  21710.       ** date is already on the appropriate weekday, this is a no-op.

  21711.       */

  21712.       if( sqlite3_strnicmp(z, "weekday ", 8)==0

  21713.                && sqlite3AtoF(&z[8], &r, sqlite3Strlen30(&z[8]), SQLITE_UTF8)>0

  21714.                && (n=(int)r)==r && n>=0 && r<7 ){

  21715.         sqlite3_int64 Z;

  21716.         computeYMD_HMS(p);

  21717.         p->validTZ = 0;

  21718.         p->validJD = 0;

  21719.         computeJD(p);

  21720.         Z = ((p->iJD + 129600000)/86400000) % 7;

  21721.         if( Z>n ) Z -= 7;

  21722.         p->iJD += (n - Z)*86400000;

  21723.         clearYMD_HMS_TZ(p);

  21724.         rc = 0;

  21725.       }

  21726.       break;

  21727.     }

  21728.     case 's': {

  21729.       /*

  21730.       **    start of TTTTT

  21731.       **

  21732.       ** Move the date backwards to the beginning of the current day,

  21733.       ** or month or year.

  21734.       */

  21735.       if( sqlite3_strnicmp(z, "start of ", 9)!=0 ) break;

  21736.       if( !p->validJD && !p->validYMD && !p->validHMS ) break;

  21737.       z += 9;

  21738.       computeYMD(p);

  21739.       p->validHMS = 1;

  21740.       p->h = p->m = 0;

  21741.       p->s = 0.0;

  21742.       p->rawS = 0;

  21743.       p->validTZ = 0;

  21744.       p->validJD = 0;

  21745.       if( sqlite3_stricmp(z,"month")==0 ){

  21746.         p->D = 1;

  21747.         rc = 0;

  21748.       }else if( sqlite3_stricmp(z,"year")==0 ){

  21749.         p->M = 1;

  21750.         p->D = 1;

  21751.         rc = 0;

  21752.       }else if( sqlite3_stricmp(z,"day")==0 ){

  21753.         rc = 0;

  21754.       }

  21755.       break;

  21756.     }

  21757.     case '+':

  21758.     case '-':

  21759.     case '0':

  21760.     case '1':

  21761.     case '2':

  21762.     case '3':

  21763.     case '4':

  21764.     case '5':

  21765.     case '6':

  21766.     case '7':

  21767.     case '8':

  21768.     case '9': {

  21769.       double rRounder;

  21770.       int i;

  21771.       for(n=1; z[n] && z[n]!=':' && !sqlite3Isspace(z[n]); n++){}

  21772.       if( sqlite3AtoF(z, &r, n, SQLITE_UTF8)<=0 ){

  21773.         rc = 1;

  21774.         break;

  21775.       }

  21776.       if( z[n]==':' ){

  21777.         /* A modifier of the form (+|-)HH:MM:SS.FFF adds (or subtracts) the

  21778.         ** specified number of hours, minutes, seconds, and fractional seconds

  21779.         ** to the time.  The ".FFF" may be omitted.  The ":SS.FFF" may be

  21780.         ** omitted.

  21781.         */

  21782.         const char *z2 = z;

  21783.         DateTime tx;

  21784.         sqlite3_int64 day;

  21785.         if( !sqlite3Isdigit(*z2) ) z2++;

  21786.         memset(&tx, 0, sizeof(tx));

  21787.         if( parseHhMmSs(z2, &tx) ) break;

  21788.         computeJD(&tx);

  21789.         tx.iJD -= 43200000;

  21790.         day = tx.iJD/86400000;

  21791.         tx.iJD -= day*86400000;

  21792.         if( z[0]=='-' ) tx.iJD = -tx.iJD;

  21793.         computeJD(p);

  21794.         clearYMD_HMS_TZ(p);

  21795.         p->iJD += tx.iJD;

  21796.         rc = 0;

  21797.         break;

  21798.       }

  21799. 

  21800.       /* If control reaches this point, it means the transformation is

  21801.       ** one of the forms like "+NNN days".  */

  21802.       z += n;

  21803.       while( sqlite3Isspace(*z) ) z++;

  21804.       n = sqlite3Strlen30(z);

  21805.       if( n>10 || n<3 ) break;

  21806.       if( sqlite3UpperToLower[(u8)z[n-1]]=='s' ) n--;

  21807.       computeJD(p);

  21808.       rc = 1;

  21809.       rRounder = r<0 ? -0.5 : +0.5;

  21810.       for(i=0; i<ArraySize(aXformType); i++){

  21811.         if( aXformType[i].nName==n

  21812.          && sqlite3_strnicmp(aXformType[i].zName, z, n)==0

  21813.          && r>-aXformType[i].rLimit && r<aXformType[i].rLimit

  21814.         ){

  21815.           switch( aXformType[i].eType ){

  21816.             case 1: { /* Special processing to add months */

  21817.               int x;

  21818.               computeYMD_HMS(p);

  21819.               p->M += (int)r;

  21820.               x = p->M>0 ? (p->M-1)/12 : (p->M-12)/12;

  21821.               p->Y += x;

  21822.               p->M -= x*12;

  21823.               p->validJD = 0;

  21824.               r -= (int)r;

  21825.               break;

  21826.             }

  21827.             case 2: { /* Special processing to add years */

  21828.               int y = (int)r;

  21829.               computeYMD_HMS(p);

  21830.               p->Y += y;

  21831.               p->validJD = 0;

  21832.               r -= (int)r;

  21833.               break;

  21834.             }

  21835.           }

  21836.           computeJD(p);

  21837.           p->iJD += (sqlite3_int64)(r*aXformType[i].rXform + rRounder);

  21838.           rc = 0;

  21839.           break;

  21840.         }

  21841.       }

  21842.       clearYMD_HMS_TZ(p);

  21843.       break;

  21844.     }

  21845.     default: {

  21846.       break;

  21847.     }

  21848.   }

  21849.   return rc;

  21850. }

  21851. 

  21852. /*

  21853. ** Process time function arguments.  argv[0] is a date-time stamp.

  21854. ** argv[1] and following are modifiers.  Parse them all and write

  21855. ** the resulting time into the DateTime structure p.  Return 0

  21856. ** on success and 1 if there are any errors.

  21857. **

  21858. ** If there are zero parameters (if even argv[0] is undefined)

  21859. ** then assume a default value of "now" for argv[0].

  21860. */

  21861. static int isDate(

  21862.   sqlite3_context *context, 

  21863.   int argc, 

  21864.   sqlite3_value **argv, 

  21865.   DateTime *p

  21866. ){

  21867.   int i, n;

  21868.   const unsigned char *z;

  21869.   int eType;

  21870.   memset(p, 0, sizeof(*p));

  21871.   if( argc==0 ){

  21872.     return setDateTimeToCurrent(context, p);

  21873.   }

  21874.   if( (eType = sqlite3_value_type(argv[0]))==SQLITE_FLOAT

  21875.                    || eType==SQLITE_INTEGER ){

  21876.     setRawDateNumber(p, sqlite3_value_double(argv[0]));

  21877.   }else{

  21878.     z = sqlite3_value_text(argv[0]);

  21879.     if( !z || parseDateOrTime(context, (char*)z, p) ){

  21880.       return 1;

  21881.     }

  21882.   }

  21883.   for(i=1; i<argc; i++){

  21884.     z = sqlite3_value_text(argv[i]);

  21885.     n = sqlite3_value_bytes(argv[i]);

  21886.     if( z==0 || parseModifier(context, (char*)z, n, p) ) return 1;

  21887.   }

  21888.   computeJD(p);

  21889.   if( p->isError || !validJulianDay(p->iJD) ) return 1;

  21890.   return 0;

  21891. }

  21892. 

  21893. 

  21894. /*

  21895. ** The following routines implement the various date and time functions

  21896. ** of SQLite.

  21897. */

  21898. 

  21899. /*

  21900. **    julianday( TIMESTRING, MOD, MOD, ...)

  21901. **

  21902. ** Return the julian day number of the date specified in the arguments

  21903. */

  21904. static void juliandayFunc(

  21905.   sqlite3_context *context,

  21906.   int argc,

  21907.   sqlite3_value **argv

  21908. ){

  21909.   DateTime x;

  21910.   if( isDate(context, argc, argv, &x)==0 ){

  21911.     computeJD(&x);

  21912.     sqlite3_result_double(context, x.iJD/86400000.0);

  21913.   }

  21914. }

  21915. 

  21916. /*

  21917. **    datetime( TIMESTRING, MOD, MOD, ...)

  21918. **

  21919. ** Return YYYY-MM-DD HH:MM:SS

  21920. */

  21921. static void datetimeFunc(

  21922.   sqlite3_context *context,

  21923.   int argc,

  21924.   sqlite3_value **argv

  21925. ){

  21926.   DateTime x;

  21927.   if( isDate(context, argc, argv, &x)==0 ){

  21928.     char zBuf[100];

  21929.     computeYMD_HMS(&x);

  21930.     sqlite3_snprintf(sizeof(zBuf), zBuf, "%04d-%02d-%02d %02d:%02d:%02d",

  21931.                      x.Y, x.M, x.D, x.h, x.m, (int)(x.s));

  21932.     sqlite3_result_text(context, zBuf, -1, SQLITE_TRANSIENT);

  21933.   }

  21934. }

  21935. 

  21936. /*

  21937. **    time( TIMESTRING, MOD, MOD, ...)

  21938. **

  21939. ** Return HH:MM:SS

  21940. */

  21941. static void timeFunc(

  21942.   sqlite3_context *context,

  21943.   int argc,

  21944.   sqlite3_value **argv

  21945. ){

  21946.   DateTime x;

  21947.   if( isDate(context, argc, argv, &x)==0 ){

  21948.     char zBuf[100];

  21949.     computeHMS(&x);

  21950.     sqlite3_snprintf(sizeof(zBuf), zBuf, "%02d:%02d:%02d", x.h, x.m, (int)x.s);

  21951.     sqlite3_result_text(context, zBuf, -1, SQLITE_TRANSIENT);

  21952.   }

  21953. }

  21954. 

  21955. /*

  21956. **    date( TIMESTRING, MOD, MOD, ...)

  21957. **

  21958. ** Return YYYY-MM-DD

  21959. */

  21960. static void dateFunc(

  21961.   sqlite3_context *context,

  21962.   int argc,

  21963.   sqlite3_value **argv

  21964. ){

  21965.   DateTime x;

  21966.   if( isDate(context, argc, argv, &x)==0 ){

  21967.     char zBuf[100];

  21968.     computeYMD(&x);

  21969.     sqlite3_snprintf(sizeof(zBuf), zBuf, "%04d-%02d-%02d", x.Y, x.M, x.D);

  21970.     sqlite3_result_text(context, zBuf, -1, SQLITE_TRANSIENT);

  21971.   }

  21972. }

  21973. 

  21974. /*

  21975. **    strftime( FORMAT, TIMESTRING, MOD, MOD, ...)

  21976. **

  21977. ** Return a string described by FORMAT.  Conversions as follows:

  21978. **

  21979. **   %d  day of month

  21980. **   %f  ** fractional seconds  SS.SSS

  21981. **   %H  hour 00-24

  21982. **   %j  day of year 000-366

  21983. **   %J  ** julian day number

  21984. **   %m  month 01-12

  21985. **   %M  minute 00-59

  21986. **   %s  seconds since 1970-01-01

  21987. **   %S  seconds 00-59

  21988. **   %w  day of week 0-6  sunday==0

  21989. **   %W  week of year 00-53

  21990. **   %Y  year 0000-9999

  21991. **   %%  %

  21992. */

  21993. static void strftimeFunc(

  21994.   sqlite3_context *context,

  21995.   int argc,

  21996.   sqlite3_value **argv

  21997. ){

  21998.   DateTime x;

  21999.   u64 n;

  22000.   size_t i,j;

  22001.   char *z;

  22002.   sqlite3 *db;

  22003.   const char *zFmt;

  22004.   char zBuf[100];

  22005.   if( argc==0 ) return;

  22006.   zFmt = (const char*)sqlite3_value_text(argv[0]);

  22007.   if( zFmt==0 || isDate(context, argc-1, argv+1, &x) ) return;

  22008.   db = sqlite3_context_db_handle(context);

  22009.   for(i=0, n=1; zFmt[i]; i++, n++){

  22010.     if( zFmt[i]=='%' ){

  22011.       switch( zFmt[i+1] ){

  22012.         case 'd':

  22013.         case 'H':

  22014.         case 'm':

  22015.         case 'M':

  22016.         case 'S':

  22017.         case 'W':

  22018.           n++;

  22019.           /* fall thru */

  22020.         case 'w':

  22021.         case '%':

  22022.           break;

  22023.         case 'f':

  22024.           n += 8;

  22025.           break;

  22026.         case 'j':

  22027.           n += 3;

  22028.           break;

  22029.         case 'Y':

  22030.           n += 8;

  22031.           break;

  22032.         case 's':

  22033.         case 'J':

  22034.           n += 50;

  22035.           break;

  22036.         default:

  22037.           return;  /* ERROR.  return a NULL */

  22038.       }

  22039.       i++;

  22040.     }

  22041.   }

  22042.   testcase( n==sizeof(zBuf)-1 );

  22043.   testcase( n==sizeof(zBuf) );

  22044.   testcase( n==(u64)db->aLimit[SQLITE_LIMIT_LENGTH]+1 );

  22045.   testcase( n==(u64)db->aLimit[SQLITE_LIMIT_LENGTH] );

  22046.   if( n<sizeof(zBuf) ){

  22047.     z = zBuf;

  22048.   }else if( n>(u64)db->aLimit[SQLITE_LIMIT_LENGTH] ){

  22049.     sqlite3_result_error_toobig(context);

  22050.     return;

  22051.   }else{

  22052.     z = sqlite3DbMallocRawNN(db, (int)n);

  22053.     if( z==0 ){

  22054.       sqlite3_result_error_nomem(context);

  22055.       return;

  22056.     }

  22057.   }

  22058.   computeJD(&x);

  22059.   computeYMD_HMS(&x);

  22060.   for(i=j=0; zFmt[i]; i++){

  22061.     if( zFmt[i]!='%' ){

  22062.       z[j++] = zFmt[i];

  22063.     }else{

  22064.       i++;

  22065.       switch( zFmt[i] ){

  22066.         case 'd':  sqlite3_snprintf(3, &z[j],"%02d",x.D); j+=2; break;

  22067.         case 'f': {

  22068.           double s = x.s;

  22069.           if( s>59.999 ) s = 59.999;

  22070.           sqlite3_snprintf(7, &z[j],"%06.3f", s);

  22071.           j += sqlite3Strlen30(&z[j]);

  22072.           break;

  22073.         }

  22074.         case 'H':  sqlite3_snprintf(3, &z[j],"%02d",x.h); j+=2; break;

  22075.         case 'W': /* Fall thru */

  22076.         case 'j': {

  22077.           int nDay;             /* Number of days since 1st day of year */

  22078.           DateTime y = x;

  22079.           y.validJD = 0;

  22080.           y.M = 1;

  22081.           y.D = 1;

  22082.           computeJD(&y);

  22083.           nDay = (int)((x.iJD-y.iJD+43200000)/86400000);

  22084.           if( zFmt[i]=='W' ){

  22085.             int wd;   /* 0=Monday, 1=Tuesday, ... 6=Sunday */

  22086.             wd = (int)(((x.iJD+43200000)/86400000)%7);

  22087.             sqlite3_snprintf(3, &z[j],"%02d",(nDay+7-wd)/7);

  22088.             j += 2;

  22089.           }else{

  22090.             sqlite3_snprintf(4, &z[j],"%03d",nDay+1);

  22091.             j += 3;

  22092.           }

  22093.           break;

  22094.         }

  22095.         case 'J': {

  22096.           sqlite3_snprintf(20, &z[j],"%.16g",x.iJD/86400000.0);

  22097.           j+=sqlite3Strlen30(&z[j]);

  22098.           break;

  22099.         }

  22100.         case 'm':  sqlite3_snprintf(3, &z[j],"%02d",x.M); j+=2; break;

  22101.         case 'M':  sqlite3_snprintf(3, &z[j],"%02d",x.m); j+=2; break;

  22102.         case 's': {

  22103.           sqlite3_snprintf(30,&z[j],"%lld",

  22104.                            (i64)(x.iJD/1000 - 21086676*(i64)10000));

  22105.           j += sqlite3Strlen30(&z[j]);

  22106.           break;

  22107.         }

  22108.         case 'S':  sqlite3_snprintf(3,&z[j],"%02d",(int)x.s); j+=2; break;

  22109.         case 'w': {

  22110.           z[j++] = (char)(((x.iJD+129600000)/86400000) % 7) + '0';

  22111.           break;

  22112.         }

  22113.         case 'Y': {

  22114.           sqlite3_snprintf(5,&z[j],"%04d",x.Y); j+=sqlite3Strlen30(&z[j]);

  22115.           break;

  22116.         }

  22117.         default:   z[j++] = '%'; break;

  22118.       }

  22119.     }

  22120.   }

  22121.   z[j] = 0;

  22122.   sqlite3_result_text(context, z, -1,

  22123.                       z==zBuf ? SQLITE_TRANSIENT : SQLITE_DYNAMIC);

  22124. }

  22125. 

  22126. /*

  22127. ** current_time()

  22128. **

  22129. ** This function returns the same value as time('now').

  22130. */

  22131. static void ctimeFunc(

  22132.   sqlite3_context *context,

  22133.   int NotUsed,

  22134.   sqlite3_value **NotUsed2

  22135. ){

  22136.   UNUSED_PARAMETER2(NotUsed, NotUsed2);

  22137.   timeFunc(context, 0, 0);

  22138. }

  22139. 

  22140. /*

  22141. ** current_date()

  22142. **

  22143. ** This function returns the same value as date('now').

  22144. */

  22145. static void cdateFunc(

  22146.   sqlite3_context *context,

  22147.   int NotUsed,

  22148.   sqlite3_value **NotUsed2

  22149. ){

  22150.   UNUSED_PARAMETER2(NotUsed, NotUsed2);

  22151.   dateFunc(context, 0, 0);

  22152. }

  22153. 

  22154. /*

  22155. ** current_timestamp()

  22156. **

  22157. ** This function returns the same value as datetime('now').

  22158. */

  22159. static void ctimestampFunc(

  22160.   sqlite3_context *context,

  22161.   int NotUsed,

  22162.   sqlite3_value **NotUsed2

  22163. ){

  22164.   UNUSED_PARAMETER2(NotUsed, NotUsed2);

  22165.   datetimeFunc(context, 0, 0);

  22166. }

  22167. #endif /* !defined(SQLITE_OMIT_DATETIME_FUNCS) */

  22168. 

  22169. #ifdef SQLITE_OMIT_DATETIME_FUNCS

  22170. /*

  22171. ** If the library is compiled to omit the full-scale date and time

  22172. ** handling (to get a smaller binary), the following minimal version

  22173. ** of the functions current_time(), current_date() and current_timestamp()

  22174. ** are included instead. This is to support column declarations that

  22175. ** include "DEFAULT CURRENT_TIME" etc.

  22176. **

  22177. ** This function uses the C-library functions time(), gmtime()

  22178. ** and strftime(). The format string to pass to strftime() is supplied

  22179. ** as the user-data for the function.

  22180. */

  22181. static void currentTimeFunc(

  22182.   sqlite3_context *context,

  22183.   int argc,

  22184.   sqlite3_value **argv

  22185. ){

  22186.   time_t t;

  22187.   char *zFormat = (char *)sqlite3_user_data(context);

  22188.   sqlite3_int64 iT;

  22189.   struct tm *pTm;

  22190.   struct tm sNow;

  22191.   char zBuf[20];

  22192. 

  22193.   UNUSED_PARAMETER(argc);

  22194.   UNUSED_PARAMETER(argv);

  22195. 

  22196.   iT = sqlite3StmtCurrentTime(context);

  22197.   if( iT<=0 ) return;

  22198.   t = iT/1000 - 10000*(sqlite3_int64)21086676;

  22199. #if HAVE_GMTIME_R

  22200.   pTm = gmtime_r(&t, &sNow);

  22201. #else

  22202.   sqlite3_mutex_enter(sqlite3MutexAlloc(SQLITE_MUTEX_STATIC_MASTER));

  22203.   pTm = gmtime(&t);

  22204.   if( pTm ) memcpy(&sNow, pTm, sizeof(sNow));

  22205.   sqlite3_mutex_leave(sqlite3MutexAlloc(SQLITE_MUTEX_STATIC_MASTER));

  22206. #endif

  22207.   if( pTm ){

  22208.     strftime(zBuf, 20, zFormat, &sNow);

  22209.     sqlite3_result_text(context, zBuf, -1, SQLITE_TRANSIENT);

  22210.   }

  22211. }

  22212. #endif

  22213. 

  22214. /*

  22215. ** This function registered all of the above C functions as SQL

  22216. ** functions.  This should be the only routine in this file with

  22217. ** external linkage.

  22218. */

  22219. SQLITE_PRIVATE void sqlite3RegisterDateTimeFunctions(void){

  22220.   static FuncDef aDateTimeFuncs[] = {

  22221. #ifndef SQLITE_OMIT_DATETIME_FUNCS

  22222.     PURE_DATE(julianday,        -1, 0, 0, juliandayFunc ),

  22223.     PURE_DATE(date,             -1, 0, 0, dateFunc      ),

  22224.     PURE_DATE(time,             -1, 0, 0, timeFunc      ),

  22225.     PURE_DATE(datetime,         -1, 0, 0, datetimeFunc  ),

  22226.     PURE_DATE(strftime,         -1, 0, 0, strftimeFunc  ),

  22227.     DFUNCTION(current_time,      0, 0, 0, ctimeFunc     ),

  22228.     DFUNCTION(current_timestamp, 0, 0, 0, ctimestampFunc),

  22229.     DFUNCTION(current_date,      0, 0, 0, cdateFunc     ),

  22230. #else

  22231.     STR_FUNCTION(current_time,      0, "%H:%M:%S",          0, currentTimeFunc),

  22232.     STR_FUNCTION(current_date,      0, "%Y-%m-%d",          0, currentTimeFunc),

  22233.     STR_FUNCTION(current_timestamp, 0, "%Y-%m-%d %H:%M:%S", 0, currentTimeFunc),

  22234. #endif

  22235.   };

  22236.   sqlite3InsertBuiltinFuncs(aDateTimeFuncs, ArraySize(aDateTimeFuncs));

  22237. }

  22238. 

  22239. /************** End of date.c ************************************************/

  22240. /************** Begin file os.c **********************************************/

  22241. /*

  22242. ** 2005 November 29

  22243. **

  22244. ** The author disclaims copyright to this source code.  In place of

  22245. ** a legal notice, here is a blessing:

  22246. **

  22247. **    May you do good and not evil.

  22248. **    May you find forgiveness for yourself and forgive others.

  22249. **    May you share freely, never taking more than you give.

  22250. **

  22251. ******************************************************************************

  22252. **

  22253. ** This file contains OS interface code that is common to all

  22254. ** architectures.

  22255. */

  22256. /* #include "sqliteInt.h" */

  22257. 

  22258. /*

  22259. ** If we compile with the SQLITE_TEST macro set, then the following block

  22260. ** of code will give us the ability to simulate a disk I/O error.  This

  22261. ** is used for testing the I/O recovery logic.

  22262. */

  22263. #if defined(SQLITE_TEST)

  22264. SQLITE_API int sqlite3_io_error_hit = 0;            /* Total number of I/O Errors */

  22265. SQLITE_API int sqlite3_io_error_hardhit = 0;        /* Number of non-benign errors */

  22266. SQLITE_API int sqlite3_io_error_pending = 0;        /* Count down to first I/O error */

  22267. SQLITE_API int sqlite3_io_error_persist = 0;        /* True if I/O errors persist */

  22268. SQLITE_API int sqlite3_io_error_benign = 0;         /* True if errors are benign */

  22269. SQLITE_API int sqlite3_diskfull_pending = 0;

  22270. SQLITE_API int sqlite3_diskfull = 0;

  22271. #endif /* defined(SQLITE_TEST) */

  22272. 

  22273. /*

  22274. ** When testing, also keep a count of the number of open files.

  22275. */

  22276. #if defined(SQLITE_TEST)

  22277. SQLITE_API int sqlite3_open_file_count = 0;

  22278. #endif /* defined(SQLITE_TEST) */

  22279. 

  22280. /*

  22281. ** The default SQLite sqlite3_vfs implementations do not allocate

  22282. ** memory (actually, os_unix.c allocates a small amount of memory

  22283. ** from within OsOpen()), but some third-party implementations may.

  22284. ** So we test the effects of a malloc() failing and the sqlite3OsXXX()

  22285. ** function returning SQLITE_IOERR_NOMEM using the DO_OS_MALLOC_TEST macro.

  22286. **

  22287. ** The following functions are instrumented for malloc() failure

  22288. ** testing:

  22289. **

  22290. **     sqlite3OsRead()

  22291. **     sqlite3OsWrite()

  22292. **     sqlite3OsSync()

  22293. **     sqlite3OsFileSize()

  22294. **     sqlite3OsLock()

  22295. **     sqlite3OsCheckReservedLock()

  22296. **     sqlite3OsFileControl()

  22297. **     sqlite3OsShmMap()

  22298. **     sqlite3OsOpen()

  22299. **     sqlite3OsDelete()

  22300. **     sqlite3OsAccess()

  22301. **     sqlite3OsFullPathname()

  22302. **

  22303. */

  22304. #if defined(SQLITE_TEST)

  22305. SQLITE_API int sqlite3_memdebug_vfs_oom_test = 1;

  22306.   #define DO_OS_MALLOC_TEST(x)                                       \

  22307.   if (sqlite3_memdebug_vfs_oom_test && (!x || !sqlite3JournalIsInMemory(x))) { \

  22308.     void *pTstAlloc = sqlite3Malloc(10);                             \

  22309.     if (!pTstAlloc) return SQLITE_IOERR_NOMEM_BKPT;                  \

  22310.     sqlite3_free(pTstAlloc);                                         \

  22311.   }

  22312. #else

  22313.   #define DO_OS_MALLOC_TEST(x)

  22314. #endif

  22315. 

  22316. /*

  22317. ** The following routines are convenience wrappers around methods

  22318. ** of the sqlite3_file object.  This is mostly just syntactic sugar. All

  22319. ** of this would be completely automatic if SQLite were coded using

  22320. ** C++ instead of plain old C.

  22321. */

  22322. SQLITE_PRIVATE void sqlite3OsClose(sqlite3_file *pId){

  22323.   if( pId->pMethods ){

  22324.     pId->pMethods->xClose(pId);

  22325.     pId->pMethods = 0;

  22326.   }

  22327. }

  22328. SQLITE_PRIVATE int sqlite3OsRead(sqlite3_file *id, void *pBuf, int amt, i64 offset){

  22329.   DO_OS_MALLOC_TEST(id);

  22330.   return id->pMethods->xRead(id, pBuf, amt, offset);

  22331. }

  22332. SQLITE_PRIVATE int sqlite3OsWrite(sqlite3_file *id, const void *pBuf, int amt, i64 offset){

  22333.   DO_OS_MALLOC_TEST(id);

  22334.   return id->pMethods->xWrite(id, pBuf, amt, offset);

  22335. }

  22336. SQLITE_PRIVATE int sqlite3OsTruncate(sqlite3_file *id, i64 size){

  22337.   return id->pMethods->xTruncate(id, size);

  22338. }

  22339. SQLITE_PRIVATE int sqlite3OsSync(sqlite3_file *id, int flags){

  22340.   DO_OS_MALLOC_TEST(id);

  22341.   return flags ? id->pMethods->xSync(id, flags) : SQLITE_OK;

  22342. }

  22343. SQLITE_PRIVATE int sqlite3OsFileSize(sqlite3_file *id, i64 *pSize){

  22344.   DO_OS_MALLOC_TEST(id);

  22345.   return id->pMethods->xFileSize(id, pSize);

  22346. }

  22347. SQLITE_PRIVATE int sqlite3OsLock(sqlite3_file *id, int lockType){

  22348.   DO_OS_MALLOC_TEST(id);

  22349.   return id->pMethods->xLock(id, lockType);

  22350. }

  22351. SQLITE_PRIVATE int sqlite3OsUnlock(sqlite3_file *id, int lockType){

  22352.   return id->pMethods->xUnlock(id, lockType);

  22353. }

  22354. SQLITE_PRIVATE int sqlite3OsCheckReservedLock(sqlite3_file *id, int *pResOut){

  22355.   DO_OS_MALLOC_TEST(id);

  22356.   return id->pMethods->xCheckReservedLock(id, pResOut);

  22357. }

  22358. 

  22359. /*

  22360. ** Use sqlite3OsFileControl() when we are doing something that might fail

  22361. ** and we need to know about the failures.  Use sqlite3OsFileControlHint()

  22362. ** when simply tossing information over the wall to the VFS and we do not

  22363. ** really care if the VFS receives and understands the information since it

  22364. ** is only a hint and can be safely ignored.  The sqlite3OsFileControlHint()

  22365. ** routine has no return value since the return value would be meaningless.

  22366. */

  22367. SQLITE_PRIVATE int sqlite3OsFileControl(sqlite3_file *id, int op, void *pArg){

  22368.   if( id->pMethods==0 ) return SQLITE_NOTFOUND;

  22369. #ifdef SQLITE_TEST

  22370.   if( op!=SQLITE_FCNTL_COMMIT_PHASETWO

  22371.    && op!=SQLITE_FCNTL_LOCK_TIMEOUT

  22372.   ){

  22373.     /* Faults are not injected into COMMIT_PHASETWO because, assuming SQLite

  22374.     ** is using a regular VFS, it is called after the corresponding

  22375.     ** transaction has been committed. Injecting a fault at this point

  22376.     ** confuses the test scripts - the COMMIT comand returns SQLITE_NOMEM

  22377.     ** but the transaction is committed anyway.

  22378.     **

  22379.     ** The core must call OsFileControl() though, not OsFileControlHint(),

  22380.     ** as if a custom VFS (e.g. zipvfs) returns an error here, it probably

  22381.     ** means the commit really has failed and an error should be returned

  22382.     ** to the user.  */

  22383.     DO_OS_MALLOC_TEST(id);

  22384.   }

  22385. #endif

  22386.   return id->pMethods->xFileControl(id, op, pArg);

  22387. }

  22388. SQLITE_PRIVATE void sqlite3OsFileControlHint(sqlite3_file *id, int op, void *pArg){

  22389.   if( id->pMethods ) (void)id->pMethods->xFileControl(id, op, pArg);

  22390. }

  22391. 

  22392. SQLITE_PRIVATE int sqlite3OsSectorSize(sqlite3_file *id){

  22393.   int (*xSectorSize)(sqlite3_file*) = id->pMethods->xSectorSize;

  22394.   return (xSectorSize ? xSectorSize(id) : SQLITE_DEFAULT_SECTOR_SIZE);

  22395. }

  22396. SQLITE_PRIVATE int sqlite3OsDeviceCharacteristics(sqlite3_file *id){

  22397.   return id->pMethods->xDeviceCharacteristics(id);

  22398. }

  22399. #ifndef SQLITE_OMIT_WAL

  22400. SQLITE_PRIVATE int sqlite3OsShmLock(sqlite3_file *id, int offset, int n, int flags){

  22401.   return id->pMethods->xShmLock(id, offset, n, flags);

  22402. }

  22403. SQLITE_PRIVATE void sqlite3OsShmBarrier(sqlite3_file *id){

  22404.   id->pMethods->xShmBarrier(id);

  22405. }

  22406. SQLITE_PRIVATE int sqlite3OsShmUnmap(sqlite3_file *id, int deleteFlag){

  22407.   return id->pMethods->xShmUnmap(id, deleteFlag);

  22408. }

  22409. SQLITE_PRIVATE int sqlite3OsShmMap(

  22410.   sqlite3_file *id,               /* Database file handle */

  22411.   int iPage,

  22412.   int pgsz,

  22413.   int bExtend,                    /* True to extend file if necessary */

  22414.   void volatile **pp              /* OUT: Pointer to mapping */

  22415. ){

  22416.   DO_OS_MALLOC_TEST(id);

  22417.   return id->pMethods->xShmMap(id, iPage, pgsz, bExtend, pp);

  22418. }

  22419. #endif /* SQLITE_OMIT_WAL */

  22420. 

  22421. #if SQLITE_MAX_MMAP_SIZE>0

  22422. /* The real implementation of xFetch and xUnfetch */

  22423. SQLITE_PRIVATE int sqlite3OsFetch(sqlite3_file *id, i64 iOff, int iAmt, void **pp){

  22424.   DO_OS_MALLOC_TEST(id);

  22425.   return id->pMethods->xFetch(id, iOff, iAmt, pp);

  22426. }

  22427. SQLITE_PRIVATE int sqlite3OsUnfetch(sqlite3_file *id, i64 iOff, void *p){

  22428.   return id->pMethods->xUnfetch(id, iOff, p);

  22429. }

  22430. #else

  22431. /* No-op stubs to use when memory-mapped I/O is disabled */

  22432. SQLITE_PRIVATE int sqlite3OsFetch(sqlite3_file *id, i64 iOff, int iAmt, void **pp){

  22433.   *pp = 0;

  22434.   return SQLITE_OK;

  22435. }

  22436. SQLITE_PRIVATE int sqlite3OsUnfetch(sqlite3_file *id, i64 iOff, void *p){

  22437.   return SQLITE_OK;

  22438. }

  22439. #endif

  22440. 

  22441. /*

  22442. ** The next group of routines are convenience wrappers around the

  22443. ** VFS methods.

  22444. */

  22445. SQLITE_PRIVATE int sqlite3OsOpen(

  22446.   sqlite3_vfs *pVfs,

  22447.   const char *zPath,

  22448.   sqlite3_file *pFile,

  22449.   int flags,

  22450.   int *pFlagsOut

  22451. ){

  22452.   int rc;

  22453.   DO_OS_MALLOC_TEST(0);

  22454.   /* 0x87f7f is a mask of SQLITE_OPEN_ flags that are valid to be passed

  22455.   ** down into the VFS layer.  Some SQLITE_OPEN_ flags (for example,

  22456.   ** SQLITE_OPEN_FULLMUTEX or SQLITE_OPEN_SHAREDCACHE) are blocked before

  22457.   ** reaching the VFS. */

  22458.   rc = pVfs->xOpen(pVfs, zPath, pFile, flags & 0x87f7f, pFlagsOut);

  22459.   assert( rc==SQLITE_OK || pFile->pMethods==0 );

  22460.   return rc;

  22461. }

  22462. SQLITE_PRIVATE int sqlite3OsDelete(sqlite3_vfs *pVfs, const char *zPath, int dirSync){

  22463.   DO_OS_MALLOC_TEST(0);

  22464.   assert( dirSync==0 || dirSync==1 );

  22465.   return pVfs->xDelete(pVfs, zPath, dirSync);

  22466. }

  22467. SQLITE_PRIVATE int sqlite3OsAccess(

  22468.   sqlite3_vfs *pVfs,

  22469.   const char *zPath,

  22470.   int flags,

  22471.   int *pResOut

  22472. ){

  22473.   DO_OS_MALLOC_TEST(0);

  22474.   return pVfs->xAccess(pVfs, zPath, flags, pResOut);

  22475. }

  22476. SQLITE_PRIVATE int sqlite3OsFullPathname(

  22477.   sqlite3_vfs *pVfs,

  22478.   const char *zPath,

  22479.   int nPathOut,

  22480.   char *zPathOut

  22481. ){

  22482.   DO_OS_MALLOC_TEST(0);

  22483.   zPathOut[0] = 0;

  22484.   return pVfs->xFullPathname(pVfs, zPath, nPathOut, zPathOut);

  22485. }

  22486. #ifndef SQLITE_OMIT_LOAD_EXTENSION

  22487. SQLITE_PRIVATE void *sqlite3OsDlOpen(sqlite3_vfs *pVfs, const char *zPath){

  22488.   return pVfs->xDlOpen(pVfs, zPath);

  22489. }

  22490. SQLITE_PRIVATE void sqlite3OsDlError(sqlite3_vfs *pVfs, int nByte, char *zBufOut){

  22491.   pVfs->xDlError(pVfs, nByte, zBufOut);

  22492. }

  22493. SQLITE_PRIVATE void (*sqlite3OsDlSym(sqlite3_vfs *pVfs, void *pHdle, const char *zSym))(void){

  22494.   return pVfs->xDlSym(pVfs, pHdle, zSym);

  22495. }

  22496. SQLITE_PRIVATE void sqlite3OsDlClose(sqlite3_vfs *pVfs, void *pHandle){

  22497.   pVfs->xDlClose(pVfs, pHandle);

  22498. }

  22499. #endif /* SQLITE_OMIT_LOAD_EXTENSION */

  22500. SQLITE_PRIVATE int sqlite3OsRandomness(sqlite3_vfs *pVfs, int nByte, char *zBufOut){

  22501.   return pVfs->xRandomness(pVfs, nByte, zBufOut);

  22502. }

  22503. SQLITE_PRIVATE int sqlite3OsSleep(sqlite3_vfs *pVfs, int nMicro){

  22504.   return pVfs->xSleep(pVfs, nMicro);

  22505. }

  22506. SQLITE_PRIVATE int sqlite3OsGetLastError(sqlite3_vfs *pVfs){

  22507.   return pVfs->xGetLastError ? pVfs->xGetLastError(pVfs, 0, 0) : 0;

  22508. }

  22509. SQLITE_PRIVATE int sqlite3OsCurrentTimeInt64(sqlite3_vfs *pVfs, sqlite3_int64 *pTimeOut){

  22510.   int rc;

  22511.   /* IMPLEMENTATION-OF: R-49045-42493 SQLite will use the xCurrentTimeInt64()

  22512.   ** method to get the current date and time if that method is available

  22513.   ** (if iVersion is 2 or greater and the function pointer is not NULL) and

  22514.   ** will fall back to xCurrentTime() if xCurrentTimeInt64() is

  22515.   ** unavailable.

  22516.   */

  22517.   if( pVfs->iVersion>=2 && pVfs->xCurrentTimeInt64 ){

  22518.     rc = pVfs->xCurrentTimeInt64(pVfs, pTimeOut);

  22519.   }else{

  22520.     double r;

  22521.     rc = pVfs->xCurrentTime(pVfs, &r);

  22522.     *pTimeOut = (sqlite3_int64)(r*86400000.0);

  22523.   }

  22524.   return rc;

  22525. }

  22526. 

  22527. SQLITE_PRIVATE int sqlite3OsOpenMalloc(

  22528.   sqlite3_vfs *pVfs,

  22529.   const char *zFile,

  22530.   sqlite3_file **ppFile,

  22531.   int flags,

  22532.   int *pOutFlags

  22533. ){

  22534.   int rc;

  22535.   sqlite3_file *pFile;

  22536.   pFile = (sqlite3_file *)sqlite3MallocZero(pVfs->szOsFile);

  22537.   if( pFile ){

  22538.     rc = sqlite3OsOpen(pVfs, zFile, pFile, flags, pOutFlags);

  22539.     if( rc!=SQLITE_OK ){

  22540.       sqlite3_free(pFile);

  22541.     }else{

  22542.       *ppFile = pFile;

  22543.     }

  22544.   }else{

  22545.     rc = SQLITE_NOMEM_BKPT;

  22546.   }

  22547.   return rc;

  22548. }

  22549. SQLITE_PRIVATE void sqlite3OsCloseFree(sqlite3_file *pFile){

  22550.   assert( pFile );

  22551.   sqlite3OsClose(pFile);

  22552.   sqlite3_free(pFile);

  22553. }

  22554. 

  22555. /*

  22556. ** This function is a wrapper around the OS specific implementation of

  22557. ** sqlite3_os_init(). The purpose of the wrapper is to provide the

  22558. ** ability to simulate a malloc failure, so that the handling of an

  22559. ** error in sqlite3_os_init() by the upper layers can be tested.

  22560. */

  22561. SQLITE_PRIVATE int sqlite3OsInit(void){

  22562.   void *p = sqlite3_malloc(10);

  22563.   if( p==0 ) return SQLITE_NOMEM_BKPT;

  22564.   sqlite3_free(p);

  22565.   return sqlite3_os_init();

  22566. }

  22567. 

  22568. /*

  22569. ** The list of all registered VFS implementations.

  22570. */

  22571. static sqlite3_vfs * SQLITE_WSD vfsList = 0;

  22572. #define vfsList GLOBAL(sqlite3_vfs *, vfsList)

  22573. 

  22574. /*

  22575. ** Locate a VFS by name.  If no name is given, simply return the

  22576. ** first VFS on the list.

  22577. */

  22578. SQLITE_API sqlite3_vfs *sqlite3_vfs_find(const char *zVfs){

  22579.   sqlite3_vfs *pVfs = 0;

  22580. #if SQLITE_THREADSAFE

  22581.   sqlite3_mutex *mutex;

  22582. #endif

  22583. #ifndef SQLITE_OMIT_AUTOINIT

  22584.   int rc = sqlite3_initialize();

  22585.   if( rc ) return 0;

  22586. #endif

  22587. #if SQLITE_THREADSAFE

  22588.   mutex = sqlite3MutexAlloc(SQLITE_MUTEX_STATIC_MASTER);

  22589. #endif

  22590.   sqlite3_mutex_enter(mutex);

  22591.   for(pVfs = vfsList; pVfs; pVfs=pVfs->pNext){

  22592.     if( zVfs==0 ) break;

  22593.     if( strcmp(zVfs, pVfs->zName)==0 ) break;

  22594.   }

  22595.   sqlite3_mutex_leave(mutex);

  22596.   return pVfs;

  22597. }

  22598. 

  22599. /*

  22600. ** Unlink a VFS from the linked list

  22601. */

  22602. static void vfsUnlink(sqlite3_vfs *pVfs){

  22603.   assert( sqlite3_mutex_held(sqlite3MutexAlloc(SQLITE_MUTEX_STATIC_MASTER)) );

  22604.   if( pVfs==0 ){

  22605.     /* No-op */

  22606.   }else if( vfsList==pVfs ){

  22607.     vfsList = pVfs->pNext;

  22608.   }else if( vfsList ){

  22609.     sqlite3_vfs *p = vfsList;

  22610.     while( p->pNext && p->pNext!=pVfs ){

  22611.       p = p->pNext;

  22612.     }

  22613.     if( p->pNext==pVfs ){

  22614.       p->pNext = pVfs->pNext;

  22615.     }

  22616.   }

  22617. }

  22618. 

  22619. /*

  22620. ** Register a VFS with the system.  It is harmless to register the same

  22621. ** VFS multiple times.  The new VFS becomes the default if makeDflt is

  22622. ** true.

  22623. */

  22624. SQLITE_API int sqlite3_vfs_register(sqlite3_vfs *pVfs, int makeDflt){

  22625.   MUTEX_LOGIC(sqlite3_mutex *mutex;)

  22626. #ifndef SQLITE_OMIT_AUTOINIT

  22627.   int rc = sqlite3_initialize();

  22628.   if( rc ) return rc;

  22629. #endif

  22630. #ifdef SQLITE_ENABLE_API_ARMOR

  22631.   if( pVfs==0 ) return SQLITE_MISUSE_BKPT;

  22632. #endif

  22633. 

  22634.   MUTEX_LOGIC( mutex = sqlite3MutexAlloc(SQLITE_MUTEX_STATIC_MASTER); )

  22635.   sqlite3_mutex_enter(mutex);

  22636.   vfsUnlink(pVfs);

  22637.   if( makeDflt || vfsList==0 ){

  22638.     pVfs->pNext = vfsList;

  22639.     vfsList = pVfs;

  22640.   }else{

  22641.     pVfs->pNext = vfsList->pNext;

  22642.     vfsList->pNext = pVfs;

  22643.   }

  22644.   assert(vfsList);

  22645.   sqlite3_mutex_leave(mutex);

  22646.   return SQLITE_OK;

  22647. }

  22648. 

  22649. /*

  22650. ** Unregister a VFS so that it is no longer accessible.

  22651. */

  22652. SQLITE_API int sqlite3_vfs_unregister(sqlite3_vfs *pVfs){

  22653.   MUTEX_LOGIC(sqlite3_mutex *mutex;)

  22654. #ifndef SQLITE_OMIT_AUTOINIT

  22655.   int rc = sqlite3_initialize();

  22656.   if( rc ) return rc;

  22657. #endif

  22658.   MUTEX_LOGIC( mutex = sqlite3MutexAlloc(SQLITE_MUTEX_STATIC_MASTER); )

  22659.   sqlite3_mutex_enter(mutex);

  22660.   vfsUnlink(pVfs);

  22661.   sqlite3_mutex_leave(mutex);

  22662.   return SQLITE_OK;

  22663. }

  22664. 

  22665. /************** End of os.c **************************************************/

  22666. /************** Begin file fault.c *******************************************/

  22667. /*

  22668. ** 2008 Jan 22

  22669. **

  22670. ** The author disclaims copyright to this source code.  In place of

  22671. ** a legal notice, here is a blessing:

  22672. **

  22673. **    May you do good and not evil.

  22674. **    May you find forgiveness for yourself and forgive others.

  22675. **    May you share freely, never taking more than you give.

  22676. **

  22677. *************************************************************************

  22678. **

  22679. ** This file contains code to support the concept of "benign" 

  22680. ** malloc failures (when the xMalloc() or xRealloc() method of the

  22681. ** sqlite3_mem_methods structure fails to allocate a block of memory

  22682. ** and returns 0). 

  22683. **

  22684. ** Most malloc failures are non-benign. After they occur, SQLite

  22685. ** abandons the current operation and returns an error code (usually

  22686. ** SQLITE_NOMEM) to the user. However, sometimes a fault is not necessarily

  22687. ** fatal. For example, if a malloc fails while resizing a hash table, this 

  22688. ** is completely recoverable simply by not carrying out the resize. The 

  22689. ** hash table will continue to function normally.  So a malloc failure 

  22690. ** during a hash table resize is a benign fault.

  22691. */

  22692. 

  22693. /* #include "sqliteInt.h" */

  22694. 

  22695. #ifndef SQLITE_UNTESTABLE

  22696. 

  22697. /*

  22698. ** Global variables.

  22699. */

  22700. typedef struct BenignMallocHooks BenignMallocHooks;

  22701. static SQLITE_WSD struct BenignMallocHooks {

  22702.   void (*xBenignBegin)(void);

  22703.   void (*xBenignEnd)(void);

  22704. } sqlite3Hooks = { 0, 0 };

  22705. 

  22706. /* The "wsdHooks" macro will resolve to the appropriate BenignMallocHooks

  22707. ** structure.  If writable static data is unsupported on the target,

  22708. ** we have to locate the state vector at run-time.  In the more common

  22709. ** case where writable static data is supported, wsdHooks can refer directly

  22710. ** to the "sqlite3Hooks" state vector declared above.

  22711. */

  22712. #ifdef SQLITE_OMIT_WSD

  22713. # define wsdHooksInit \

  22714.   BenignMallocHooks *x = &GLOBAL(BenignMallocHooks,sqlite3Hooks)

  22715. # define wsdHooks x[0]

  22716. #else

  22717. # define wsdHooksInit

  22718. # define wsdHooks sqlite3Hooks

  22719. #endif

  22720. 

  22721. 

  22722. /*

  22723. ** Register hooks to call when sqlite3BeginBenignMalloc() and

  22724. ** sqlite3EndBenignMalloc() are called, respectively.

  22725. */

  22726. SQLITE_PRIVATE void sqlite3BenignMallocHooks(

  22727.   void (*xBenignBegin)(void),

  22728.   void (*xBenignEnd)(void)

  22729. ){

  22730.   wsdHooksInit;

  22731.   wsdHooks.xBenignBegin = xBenignBegin;

  22732.   wsdHooks.xBenignEnd = xBenignEnd;

  22733. }

  22734. 

  22735. /*

  22736. ** This (sqlite3EndBenignMalloc()) is called by SQLite code to indicate that

  22737. ** subsequent malloc failures are benign. A call to sqlite3EndBenignMalloc()

  22738. ** indicates that subsequent malloc failures are non-benign.

  22739. */

  22740. SQLITE_PRIVATE void sqlite3BeginBenignMalloc(void){

  22741.   wsdHooksInit;

  22742.   if( wsdHooks.xBenignBegin ){

  22743.     wsdHooks.xBenignBegin();

  22744.   }

  22745. }

  22746. SQLITE_PRIVATE void sqlite3EndBenignMalloc(void){

  22747.   wsdHooksInit;

  22748.   if( wsdHooks.xBenignEnd ){

  22749.     wsdHooks.xBenignEnd();

  22750.   }

  22751. }

  22752. 

  22753. #endif   /* #ifndef SQLITE_UNTESTABLE */

  22754. 

  22755. /************** End of fault.c ***********************************************/

  22756. /************** Begin file mem0.c ********************************************/

  22757. /*

  22758. ** 2008 October 28

  22759. **

  22760. ** The author disclaims copyright to this source code.  In place of

  22761. ** a legal notice, here is a blessing:

  22762. **

  22763. **    May you do good and not evil.

  22764. **    May you find forgiveness for yourself and forgive others.

  22765. **    May you share freely, never taking more than you give.

  22766. **

  22767. *************************************************************************

  22768. **

  22769. ** This file contains a no-op memory allocation drivers for use when

  22770. ** SQLITE_ZERO_MALLOC is defined.  The allocation drivers implemented

  22771. ** here always fail.  SQLite will not operate with these drivers.  These

  22772. ** are merely placeholders.  Real drivers must be substituted using

  22773. ** sqlite3_config() before SQLite will operate.

  22774. */

  22775. /* #include "sqliteInt.h" */

  22776. 

  22777. /*

  22778. ** This version of the memory allocator is the default.  It is

  22779. ** used when no other memory allocator is specified using compile-time

  22780. ** macros.

  22781. */

  22782. #ifdef SQLITE_ZERO_MALLOC

  22783. 

  22784. /*

  22785. ** No-op versions of all memory allocation routines

  22786. */

  22787. static void *sqlite3MemMalloc(int nByte){ return 0; }

  22788. static void sqlite3MemFree(void *pPrior){ return; }

  22789. static void *sqlite3MemRealloc(void *pPrior, int nByte){ return 0; }

  22790. static int sqlite3MemSize(void *pPrior){ return 0; }

  22791. static int sqlite3MemRoundup(int n){ return n; }

  22792. static int sqlite3MemInit(void *NotUsed){ return SQLITE_OK; }

  22793. static void sqlite3MemShutdown(void *NotUsed){ return; }

  22794. 

  22795. /*

  22796. ** This routine is the only routine in this file with external linkage.

  22797. **

  22798. ** Populate the low-level memory allocation function pointers in

  22799. ** sqlite3GlobalConfig.m with pointers to the routines in this file.

  22800. */

  22801. SQLITE_PRIVATE void sqlite3MemSetDefault(void){

  22802.   static const sqlite3_mem_methods defaultMethods = {

  22803.      sqlite3MemMalloc,

  22804.      sqlite3MemFree,

  22805.      sqlite3MemRealloc,

  22806.      sqlite3MemSize,

  22807.      sqlite3MemRoundup,

  22808.      sqlite3MemInit,

  22809.      sqlite3MemShutdown,

  22810.      0

  22811.   };

  22812.   sqlite3_config(SQLITE_CONFIG_MALLOC, &defaultMethods);

  22813. }

  22814. 

  22815. #endif /* SQLITE_ZERO_MALLOC */

  22816. 

  22817. /************** End of mem0.c ************************************************/

  22818. /************** Begin file mem1.c ********************************************/

  22819. /*

  22820. ** 2007 August 14

  22821. **

  22822. ** The author disclaims copyright to this source code.  In place of

  22823. ** a legal notice, here is a blessing:

  22824. **

  22825. **    May you do good and not evil.

  22826. **    May you find forgiveness for yourself and forgive others.

  22827. **    May you share freely, never taking more than you give.

  22828. **

  22829. *************************************************************************

  22830. **

  22831. ** This file contains low-level memory allocation drivers for when

  22832. ** SQLite will use the standard C-library malloc/realloc/free interface

  22833. ** to obtain the memory it needs.

  22834. **

  22835. ** This file contains implementations of the low-level memory allocation

  22836. ** routines specified in the sqlite3_mem_methods object.  The content of

  22837. ** this file is only used if SQLITE_SYSTEM_MALLOC is defined.  The

  22838. ** SQLITE_SYSTEM_MALLOC macro is defined automatically if neither the

  22839. ** SQLITE_MEMDEBUG nor the SQLITE_WIN32_MALLOC macros are defined.  The

  22840. ** default configuration is to use memory allocation routines in this

  22841. ** file.

  22842. **

  22843. ** C-preprocessor macro summary:

  22844. **

  22845. **    HAVE_MALLOC_USABLE_SIZE     The configure script sets this symbol if

  22846. **                                the malloc_usable_size() interface exists

  22847. **                                on the target platform.  Or, this symbol

  22848. **                                can be set manually, if desired.

  22849. **                                If an equivalent interface exists by

  22850. **                                a different name, using a separate -D

  22851. **                                option to rename it.

  22852. **

  22853. **    SQLITE_WITHOUT_ZONEMALLOC   Some older macs lack support for the zone

  22854. **                                memory allocator.  Set this symbol to enable

  22855. **                                building on older macs.

  22856. **

  22857. **    SQLITE_WITHOUT_MSIZE        Set this symbol to disable the use of

  22858. **                                _msize() on windows systems.  This might

  22859. **                                be necessary when compiling for Delphi,

  22860. **                                for example.

  22861. */

  22862. /* #include "sqliteInt.h" */

  22863. 

  22864. /*

  22865. ** This version of the memory allocator is the default.  It is

  22866. ** used when no other memory allocator is specified using compile-time

  22867. ** macros.

  22868. */

  22869. #ifdef SQLITE_SYSTEM_MALLOC

  22870. #if defined(__APPLE__) && !defined(SQLITE_WITHOUT_ZONEMALLOC)

  22871. 

  22872. /*

  22873. ** Use the zone allocator available on apple products unless the

  22874. ** SQLITE_WITHOUT_ZONEMALLOC symbol is defined.

  22875. */

  22876. #include <sys/sysctl.h>

  22877. #include <malloc/malloc.h>

  22878. #ifdef SQLITE_MIGHT_BE_SINGLE_CORE

  22879. #include <libkern/OSAtomic.h>

  22880. #endif /* SQLITE_MIGHT_BE_SINGLE_CORE */

  22881. static malloc_zone_t* _sqliteZone_;

  22882. #define SQLITE_MALLOC(x) malloc_zone_malloc(_sqliteZone_, (x))

  22883. #define SQLITE_FREE(x) malloc_zone_free(_sqliteZone_, (x));

  22884. #define SQLITE_REALLOC(x,y) malloc_zone_realloc(_sqliteZone_, (x), (y))

  22885. #define SQLITE_MALLOCSIZE(x) \

  22886.         (_sqliteZone_ ? _sqliteZone_->size(_sqliteZone_,x) : malloc_size(x))

  22887. 

  22888. #else /* if not __APPLE__ */

  22889. 

  22890. /*

  22891. ** Use standard C library malloc and free on non-Apple systems.  

  22892. ** Also used by Apple systems if SQLITE_WITHOUT_ZONEMALLOC is defined.

  22893. */

  22894. #define SQLITE_MALLOC(x)             malloc(x)

  22895. #define SQLITE_FREE(x)               free(x)

  22896. #define SQLITE_REALLOC(x,y)          realloc((x),(y))

  22897. 

  22898. /*

  22899. ** The malloc.h header file is needed for malloc_usable_size() function

  22900. ** on some systems (e.g. Linux).

  22901. */

  22902. #if HAVE_MALLOC_H && HAVE_MALLOC_USABLE_SIZE

  22903. #  define SQLITE_USE_MALLOC_H 1

  22904. #  define SQLITE_USE_MALLOC_USABLE_SIZE 1

  22905. /*

  22906. ** The MSVCRT has malloc_usable_size(), but it is called _msize().  The

  22907. ** use of _msize() is automatic, but can be disabled by compiling with

  22908. ** -DSQLITE_WITHOUT_MSIZE.  Using the _msize() function also requires

  22909. ** the malloc.h header file.

  22910. */

  22911. #elif defined(_MSC_VER) && !defined(SQLITE_WITHOUT_MSIZE)

  22912. #  define SQLITE_USE_MALLOC_H

  22913. #  define SQLITE_USE_MSIZE

  22914. #endif

  22915. 

  22916. /*

  22917. ** Include the malloc.h header file, if necessary.  Also set define macro

  22918. ** SQLITE_MALLOCSIZE to the appropriate function name, which is _msize()

  22919. ** for MSVC and malloc_usable_size() for most other systems (e.g. Linux).

  22920. ** The memory size function can always be overridden manually by defining

  22921. ** the macro SQLITE_MALLOCSIZE to the desired function name.

  22922. */

  22923. #if defined(SQLITE_USE_MALLOC_H)

  22924. #  include <malloc.h>

  22925. #  if defined(SQLITE_USE_MALLOC_USABLE_SIZE)

  22926. #    if !defined(SQLITE_MALLOCSIZE)

  22927. #      define SQLITE_MALLOCSIZE(x)   malloc_usable_size(x)

  22928. #    endif

  22929. #  elif defined(SQLITE_USE_MSIZE)

  22930. #    if !defined(SQLITE_MALLOCSIZE)

  22931. #      define SQLITE_MALLOCSIZE      _msize

  22932. #    endif

  22933. #  endif

  22934. #endif /* defined(SQLITE_USE_MALLOC_H) */

  22935. 

  22936. #endif /* __APPLE__ or not __APPLE__ */

  22937. 

  22938. /*

  22939. ** Like malloc(), but remember the size of the allocation

  22940. ** so that we can find it later using sqlite3MemSize().

  22941. **

  22942. ** For this low-level routine, we are guaranteed that nByte>0 because

  22943. ** cases of nByte<=0 will be intercepted and dealt with by higher level

  22944. ** routines.

  22945. */

  22946. static void *sqlite3MemMalloc(int nByte){

  22947. #ifdef SQLITE_MALLOCSIZE

  22948.   void *p;

  22949.   testcase( ROUND8(nByte)==nByte );

  22950.   p = SQLITE_MALLOC( nByte );

  22951.   if( p==0 ){

  22952.     testcase( sqlite3GlobalConfig.xLog!=0 );

  22953.     sqlite3_log(SQLITE_NOMEM, "failed to allocate %u bytes of memory", nByte);

  22954.   }

  22955.   return p;

  22956. #else

  22957.   sqlite3_int64 *p;

  22958.   assert( nByte>0 );

  22959.   testcase( ROUND8(nByte)!=nByte );

  22960.   p = SQLITE_MALLOC( nByte+8 );

  22961.   if( p ){

  22962.     p[0] = nByte;

  22963.     p++;

  22964.   }else{

  22965.     testcase( sqlite3GlobalConfig.xLog!=0 );

  22966.     sqlite3_log(SQLITE_NOMEM, "failed to allocate %u bytes of memory", nByte);

  22967.   }

  22968.   return (void *)p;

  22969. #endif

  22970. }

  22971. 

  22972. /*

  22973. ** Like free() but works for allocations obtained from sqlite3MemMalloc()

  22974. ** or sqlite3MemRealloc().

  22975. **

  22976. ** For this low-level routine, we already know that pPrior!=0 since

  22977. ** cases where pPrior==0 will have been intecepted and dealt with

  22978. ** by higher-level routines.

  22979. */

  22980. static void sqlite3MemFree(void *pPrior){

  22981. #ifdef SQLITE_MALLOCSIZE

  22982.   SQLITE_FREE(pPrior);

  22983. #else

  22984.   sqlite3_int64 *p = (sqlite3_int64*)pPrior;

  22985.   assert( pPrior!=0 );

  22986.   p--;

  22987.   SQLITE_FREE(p);

  22988. #endif

  22989. }

  22990. 

  22991. /*

  22992. ** Report the allocated size of a prior return from xMalloc()

  22993. ** or xRealloc().

  22994. */

  22995. static int sqlite3MemSize(void *pPrior){

  22996. #ifdef SQLITE_MALLOCSIZE

  22997.   assert( pPrior!=0 );

  22998.   return (int)SQLITE_MALLOCSIZE(pPrior);

  22999. #else

  23000.   sqlite3_int64 *p;

  23001.   assert( pPrior!=0 );

  23002.   p = (sqlite3_int64*)pPrior;

  23003.   p--;

  23004.   return (int)p[0];

  23005. #endif

  23006. }

  23007. 

  23008. /*

  23009. ** Like realloc().  Resize an allocation previously obtained from

  23010. ** sqlite3MemMalloc().

  23011. **

  23012. ** For this low-level interface, we know that pPrior!=0.  Cases where

  23013. ** pPrior==0 while have been intercepted by higher-level routine and

  23014. ** redirected to xMalloc.  Similarly, we know that nByte>0 because

  23015. ** cases where nByte<=0 will have been intercepted by higher-level

  23016. ** routines and redirected to xFree.

  23017. */

  23018. static void *sqlite3MemRealloc(void *pPrior, int nByte){

  23019. #ifdef SQLITE_MALLOCSIZE

  23020.   void *p = SQLITE_REALLOC(pPrior, nByte);

  23021.   if( p==0 ){

  23022.     testcase( sqlite3GlobalConfig.xLog!=0 );

  23023.     sqlite3_log(SQLITE_NOMEM,

  23024.       "failed memory resize %u to %u bytes",

  23025.       SQLITE_MALLOCSIZE(pPrior), nByte);

  23026.   }

  23027.   return p;

  23028. #else

  23029.   sqlite3_int64 *p = (sqlite3_int64*)pPrior;

  23030.   assert( pPrior!=0 && nByte>0 );

  23031.   assert( nByte==ROUND8(nByte) ); /* EV: R-46199-30249 */

  23032.   p--;

  23033.   p = SQLITE_REALLOC(p, nByte+8 );

  23034.   if( p ){

  23035.     p[0] = nByte;

  23036.     p++;

  23037.   }else{

  23038.     testcase( sqlite3GlobalConfig.xLog!=0 );

  23039.     sqlite3_log(SQLITE_NOMEM,

  23040.       "failed memory resize %u to %u bytes",

  23041.       sqlite3MemSize(pPrior), nByte);

  23042.   }

  23043.   return (void*)p;

  23044. #endif

  23045. }

  23046. 

  23047. /*

  23048. ** Round up a request size to the next valid allocation size.

  23049. */

  23050. static int sqlite3MemRoundup(int n){

  23051.   return ROUND8(n);

  23052. }

  23053. 

  23054. /*

  23055. ** Initialize this module.

  23056. */

  23057. static int sqlite3MemInit(void *NotUsed){

  23058. #if defined(__APPLE__) && !defined(SQLITE_WITHOUT_ZONEMALLOC)

  23059.   int cpuCount;

  23060.   size_t len;

  23061.   if( _sqliteZone_ ){

  23062.     return SQLITE_OK;

  23063.   }

  23064.   len = sizeof(cpuCount);

  23065.   /* One usually wants to use hw.acctivecpu for MT decisions, but not here */

  23066.   sysctlbyname("hw.ncpu", &cpuCount, &len, NULL, 0);

  23067.   if( cpuCount>1 ){

  23068.     /* defer MT decisions to system malloc */

  23069.     _sqliteZone_ = malloc_default_zone();

  23070.   }else{

  23071.     /* only 1 core, use our own zone to contention over global locks, 

  23072.     ** e.g. we have our own dedicated locks */

  23073.     _sqliteZone_ = malloc_create_zone(4096, 0);

  23074.     malloc_set_zone_name(_sqliteZone_, "Sqlite_Heap");

  23075.   }

  23076. #endif /*  defined(__APPLE__) && !defined(SQLITE_WITHOUT_ZONEMALLOC) */

  23077.   UNUSED_PARAMETER(NotUsed);

  23078.   return SQLITE_OK;

  23079. }

  23080. 

  23081. /*

  23082. ** Deinitialize this module.

  23083. */

  23084. static void sqlite3MemShutdown(void *NotUsed){

  23085.   UNUSED_PARAMETER(NotUsed);

  23086.   return;

  23087. }

  23088. 

  23089. /*

  23090. ** This routine is the only routine in this file with external linkage.

  23091. **

  23092. ** Populate the low-level memory allocation function pointers in

  23093. ** sqlite3GlobalConfig.m with pointers to the routines in this file.

  23094. */

  23095. SQLITE_PRIVATE void sqlite3MemSetDefault(void){

  23096.   static const sqlite3_mem_methods defaultMethods = {

  23097.      sqlite3MemMalloc,

  23098.      sqlite3MemFree,

  23099.      sqlite3MemRealloc,

  23100.      sqlite3MemSize,

  23101.      sqlite3MemRoundup,

  23102.      sqlite3MemInit,

  23103.      sqlite3MemShutdown,

  23104.      0

  23105.   };

  23106.   sqlite3_config(SQLITE_CONFIG_MALLOC, &defaultMethods);

  23107. }

  23108. 

  23109. #endif /* SQLITE_SYSTEM_MALLOC */

  23110. 

  23111. /************** End of mem1.c ************************************************/

  23112. /************** Begin file mem2.c ********************************************/

  23113. /*

  23114. ** 2007 August 15

  23115. **

  23116. ** The author disclaims copyright to this source code.  In place of

  23117. ** a legal notice, here is a blessing:

  23118. **

  23119. **    May you do good and not evil.

  23120. **    May you find forgiveness for yourself and forgive others.

  23121. **    May you share freely, never taking more than you give.

  23122. **

  23123. *************************************************************************

  23124. **

  23125. ** This file contains low-level memory allocation drivers for when

  23126. ** SQLite will use the standard C-library malloc/realloc/free interface

  23127. ** to obtain the memory it needs while adding lots of additional debugging

  23128. ** information to each allocation in order to help detect and fix memory

  23129. ** leaks and memory usage errors.

  23130. **

  23131. ** This file contains implementations of the low-level memory allocation

  23132. ** routines specified in the sqlite3_mem_methods object.

  23133. */

  23134. /* #include "sqliteInt.h" */

  23135. 

  23136. /*

  23137. ** This version of the memory allocator is used only if the

  23138. ** SQLITE_MEMDEBUG macro is defined

  23139. */

  23140. #ifdef SQLITE_MEMDEBUG

  23141. 

  23142. /*

  23143. ** The backtrace functionality is only available with GLIBC

  23144. */

  23145. #ifdef __GLIBC__

  23146.   extern int backtrace(void**,int);

  23147.   extern void backtrace_symbols_fd(void*const*,int,int);

  23148. #else

  23149. # define backtrace(A,B) 1

  23150. # define backtrace_symbols_fd(A,B,C)

  23151. #endif

  23152. /* #include <stdio.h> */

  23153. 

  23154. /*

  23155. ** Each memory allocation looks like this:

  23156. **

  23157. **  ------------------------------------------------------------------------

  23158. **  | Title |  backtrace pointers |  MemBlockHdr |  allocation |  EndGuard |

  23159. **  ------------------------------------------------------------------------

  23160. **

  23161. ** The application code sees only a pointer to the allocation.  We have

  23162. ** to back up from the allocation pointer to find the MemBlockHdr.  The

  23163. ** MemBlockHdr tells us the size of the allocation and the number of

  23164. ** backtrace pointers.  There is also a guard word at the end of the

  23165. ** MemBlockHdr.

  23166. */

  23167. struct MemBlockHdr {

  23168.   i64 iSize;                          /* Size of this allocation */

  23169.   struct MemBlockHdr *pNext, *pPrev;  /* Linked list of all unfreed memory */

  23170.   char nBacktrace;                    /* Number of backtraces on this alloc */

  23171.   char nBacktraceSlots;               /* Available backtrace slots */

  23172.   u8 nTitle;                          /* Bytes of title; includes '\0' */

  23173.   u8 eType;                           /* Allocation type code */

  23174.   int iForeGuard;                     /* Guard word for sanity */

  23175. };

  23176. 

  23177. /*

  23178. ** Guard words

  23179. */

  23180. #define FOREGUARD 0x80F5E153

  23181. #define REARGUARD 0xE4676B53

  23182. 

  23183. /*

  23184. ** Number of malloc size increments to track.

  23185. */

  23186. #define NCSIZE  1000

  23187. 

  23188. /*

  23189. ** All of the static variables used by this module are collected

  23190. ** into a single structure named "mem".  This is to keep the

  23191. ** static variables organized and to reduce namespace pollution

  23192. ** when this module is combined with other in the amalgamation.

  23193. */

  23194. static struct {

  23195.   

  23196.   /*

  23197.   ** Mutex to control access to the memory allocation subsystem.

  23198.   */

  23199.   sqlite3_mutex *mutex;

  23200. 

  23201.   /*

  23202.   ** Head and tail of a linked list of all outstanding allocations

  23203.   */

  23204.   struct MemBlockHdr *pFirst;

  23205.   struct MemBlockHdr *pLast;

  23206.   

  23207.   /*

  23208.   ** The number of levels of backtrace to save in new allocations.

  23209.   */

  23210.   int nBacktrace;

  23211.   void (*xBacktrace)(int, int, void **);

  23212. 

  23213.   /*

  23214.   ** Title text to insert in front of each block

  23215.   */

  23216.   int nTitle;        /* Bytes of zTitle to save.  Includes '\0' and padding */

  23217.   char zTitle[100];  /* The title text */

  23218. 

  23219.   /* 

  23220.   ** sqlite3MallocDisallow() increments the following counter.

  23221.   ** sqlite3MallocAllow() decrements it.

  23222.   */

  23223.   int disallow; /* Do not allow memory allocation */

  23224. 

  23225.   /*

  23226.   ** Gather statistics on the sizes of memory allocations.

  23227.   ** nAlloc[i] is the number of allocation attempts of i*8

  23228.   ** bytes.  i==NCSIZE is the number of allocation attempts for

  23229.   ** sizes more than NCSIZE*8 bytes.

  23230.   */

  23231.   int nAlloc[NCSIZE];      /* Total number of allocations */

  23232.   int nCurrent[NCSIZE];    /* Current number of allocations */

  23233.   int mxCurrent[NCSIZE];   /* Highwater mark for nCurrent */

  23234. 

  23235. } mem;

  23236. 

  23237. 

  23238. /*

  23239. ** Adjust memory usage statistics

  23240. */

  23241. static void adjustStats(int iSize, int increment){

  23242.   int i = ROUND8(iSize)/8;

  23243.   if( i>NCSIZE-1 ){

  23244.     i = NCSIZE - 1;

  23245.   }

  23246.   if( increment>0 ){

  23247.     mem.nAlloc[i]++;

  23248.     mem.nCurrent[i]++;

  23249.     if( mem.nCurrent[i]>mem.mxCurrent[i] ){

  23250.       mem.mxCurrent[i] = mem.nCurrent[i];

  23251.     }

  23252.   }else{

  23253.     mem.nCurrent[i]--;

  23254.     assert( mem.nCurrent[i]>=0 );

  23255.   }

  23256. }

  23257. 

  23258. /*

  23259. ** Given an allocation, find the MemBlockHdr for that allocation.

  23260. **

  23261. ** This routine checks the guards at either end of the allocation and

  23262. ** if they are incorrect it asserts.

  23263. */

  23264. static struct MemBlockHdr *sqlite3MemsysGetHeader(void *pAllocation){

  23265.   struct MemBlockHdr *p;

  23266.   int *pInt;

  23267.   u8 *pU8;

  23268.   int nReserve;

  23269. 

  23270.   p = (struct MemBlockHdr*)pAllocation;

  23271.   p--;

  23272.   assert( p->iForeGuard==(int)FOREGUARD );

  23273.   nReserve = ROUND8(p->iSize);

  23274.   pInt = (int*)pAllocation;

  23275.   pU8 = (u8*)pAllocation;

  23276.   assert( pInt[nReserve/sizeof(int)]==(int)REARGUARD );

  23277.   /* This checks any of the "extra" bytes allocated due

  23278.   ** to rounding up to an 8 byte boundary to ensure 

  23279.   ** they haven't been overwritten.

  23280.   */

  23281.   while( nReserve-- > p->iSize ) assert( pU8[nReserve]==0x65 );

  23282.   return p;

  23283. }

  23284. 

  23285. /*

  23286. ** Return the number of bytes currently allocated at address p.

  23287. */

  23288. static int sqlite3MemSize(void *p){

  23289.   struct MemBlockHdr *pHdr;

  23290.   if( !p ){

  23291.     return 0;

  23292.   }

  23293.   pHdr = sqlite3MemsysGetHeader(p);

  23294.   return (int)pHdr->iSize;

  23295. }

  23296. 

  23297. /*

  23298. ** Initialize the memory allocation subsystem.

  23299. */

  23300. static int sqlite3MemInit(void *NotUsed){

  23301.   UNUSED_PARAMETER(NotUsed);

  23302.   assert( (sizeof(struct MemBlockHdr)&7) == 0 );

  23303.   if( !sqlite3GlobalConfig.bMemstat ){

  23304.     /* If memory status is enabled, then the malloc.c wrapper will already

  23305.     ** hold the STATIC_MEM mutex when the routines here are invoked. */

  23306.     mem.mutex = sqlite3MutexAlloc(SQLITE_MUTEX_STATIC_MEM);

  23307.   }

  23308.   return SQLITE_OK;

  23309. }

  23310. 

  23311. /*

  23312. ** Deinitialize the memory allocation subsystem.

  23313. */

  23314. static void sqlite3MemShutdown(void *NotUsed){

  23315.   UNUSED_PARAMETER(NotUsed);

  23316.   mem.mutex = 0;

  23317. }

  23318. 

  23319. /*

  23320. ** Round up a request size to the next valid allocation size.

  23321. */

  23322. static int sqlite3MemRoundup(int n){

  23323.   return ROUND8(n);

  23324. }

  23325. 

  23326. /*

  23327. ** Fill a buffer with pseudo-random bytes.  This is used to preset

  23328. ** the content of a new memory allocation to unpredictable values and

  23329. ** to clear the content of a freed allocation to unpredictable values.

  23330. */

  23331. static void randomFill(char *pBuf, int nByte){

  23332.   unsigned int x, y, r;

  23333.   x = SQLITE_PTR_TO_INT(pBuf);

  23334.   y = nByte | 1;

  23335.   while( nByte >= 4 ){

  23336.     x = (x>>1) ^ (-(int)(x&1) & 0xd0000001);

  23337.     y = y*1103515245 + 12345;

  23338.     r = x ^ y;

  23339.     *(int*)pBuf = r;

  23340.     pBuf += 4;

  23341.     nByte -= 4;

  23342.   }

  23343.   while( nByte-- > 0 ){

  23344.     x = (x>>1) ^ (-(int)(x&1) & 0xd0000001);

  23345.     y = y*1103515245 + 12345;

  23346.     r = x ^ y;

  23347.     *(pBuf++) = r & 0xff;

  23348.   }

  23349. }

  23350. 

  23351. /*

  23352. ** Allocate nByte bytes of memory.

  23353. */

  23354. static void *sqlite3MemMalloc(int nByte){

  23355.   struct MemBlockHdr *pHdr;

  23356.   void **pBt;

  23357.   char *z;

  23358.   int *pInt;

  23359.   void *p = 0;

  23360.   int totalSize;

  23361.   int nReserve;

  23362.   sqlite3_mutex_enter(mem.mutex);

  23363.   assert( mem.disallow==0 );

  23364.   nReserve = ROUND8(nByte);

  23365.   totalSize = nReserve + sizeof(*pHdr) + sizeof(int) +

  23366.                mem.nBacktrace*sizeof(void*) + mem.nTitle;

  23367.   p = malloc(totalSize);

  23368.   if( p ){

  23369.     z = p;

  23370.     pBt = (void**)&z[mem.nTitle];

  23371.     pHdr = (struct MemBlockHdr*)&pBt[mem.nBacktrace];

  23372.     pHdr->pNext = 0;

  23373.     pHdr->pPrev = mem.pLast;

  23374.     if( mem.pLast ){

  23375.       mem.pLast->pNext = pHdr;

  23376.     }else{

  23377.       mem.pFirst = pHdr;

  23378.     }

  23379.     mem.pLast = pHdr;

  23380.     pHdr->iForeGuard = FOREGUARD;

  23381.     pHdr->eType = MEMTYPE_HEAP;

  23382.     pHdr->nBacktraceSlots = mem.nBacktrace;

  23383.     pHdr->nTitle = mem.nTitle;

  23384.     if( mem.nBacktrace ){

  23385.       void *aAddr[40];

  23386.       pHdr->nBacktrace = backtrace(aAddr, mem.nBacktrace+1)-1;

  23387.       memcpy(pBt, &aAddr[1], pHdr->nBacktrace*sizeof(void*));

  23388.       assert(pBt[0]);

  23389.       if( mem.xBacktrace ){

  23390.         mem.xBacktrace(nByte, pHdr->nBacktrace-1, &aAddr[1]);

  23391.       }

  23392.     }else{

  23393.       pHdr->nBacktrace = 0;

  23394.     }

  23395.     if( mem.nTitle ){

  23396.       memcpy(z, mem.zTitle, mem.nTitle);

  23397.     }

  23398.     pHdr->iSize = nByte;

  23399.     adjustStats(nByte, +1);

  23400.     pInt = (int*)&pHdr[1];

  23401.     pInt[nReserve/sizeof(int)] = REARGUARD;

  23402.     randomFill((char*)pInt, nByte);

  23403.     memset(((char*)pInt)+nByte, 0x65, nReserve-nByte);

  23404.     p = (void*)pInt;

  23405.   }

  23406.   sqlite3_mutex_leave(mem.mutex);

  23407.   return p; 

  23408. }

  23409. 

  23410. /*

  23411. ** Free memory.

  23412. */

  23413. static void sqlite3MemFree(void *pPrior){

  23414.   struct MemBlockHdr *pHdr;

  23415.   void **pBt;

  23416.   char *z;

  23417.   assert( sqlite3GlobalConfig.bMemstat || sqlite3GlobalConfig.bCoreMutex==0 

  23418.        || mem.mutex!=0 );

  23419.   pHdr = sqlite3MemsysGetHeader(pPrior);

  23420.   pBt = (void**)pHdr;

  23421.   pBt -= pHdr->nBacktraceSlots;

  23422.   sqlite3_mutex_enter(mem.mutex);

  23423.   if( pHdr->pPrev ){

  23424.     assert( pHdr->pPrev->pNext==pHdr );

  23425.     pHdr->pPrev->pNext = pHdr->pNext;

  23426.   }else{

  23427.     assert( mem.pFirst==pHdr );

  23428.     mem.pFirst = pHdr->pNext;

  23429.   }

  23430.   if( pHdr->pNext ){

  23431.     assert( pHdr->pNext->pPrev==pHdr );

  23432.     pHdr->pNext->pPrev = pHdr->pPrev;

  23433.   }else{

  23434.     assert( mem.pLast==pHdr );

  23435.     mem.pLast = pHdr->pPrev;

  23436.   }

  23437.   z = (char*)pBt;

  23438.   z -= pHdr->nTitle;

  23439.   adjustStats((int)pHdr->iSize, -1);

  23440.   randomFill(z, sizeof(void*)*pHdr->nBacktraceSlots + sizeof(*pHdr) +

  23441.                 (int)pHdr->iSize + sizeof(int) + pHdr->nTitle);

  23442.   free(z);

  23443.   sqlite3_mutex_leave(mem.mutex);  

  23444. }

  23445. 

  23446. /*

  23447. ** Change the size of an existing memory allocation.

  23448. **

  23449. ** For this debugging implementation, we *always* make a copy of the

  23450. ** allocation into a new place in memory.  In this way, if the 

  23451. ** higher level code is using pointer to the old allocation, it is 

  23452. ** much more likely to break and we are much more liking to find

  23453. ** the error.

  23454. */

  23455. static void *sqlite3MemRealloc(void *pPrior, int nByte){

  23456.   struct MemBlockHdr *pOldHdr;

  23457.   void *pNew;

  23458.   assert( mem.disallow==0 );

  23459.   assert( (nByte & 7)==0 );     /* EV: R-46199-30249 */

  23460.   pOldHdr = sqlite3MemsysGetHeader(pPrior);

  23461.   pNew = sqlite3MemMalloc(nByte);

  23462.   if( pNew ){

  23463.     memcpy(pNew, pPrior, (int)(nByte<pOldHdr->iSize ? nByte : pOldHdr->iSize));

  23464.     if( nByte>pOldHdr->iSize ){

  23465.       randomFill(&((char*)pNew)[pOldHdr->iSize], nByte - (int)pOldHdr->iSize);

  23466.     }

  23467.     sqlite3MemFree(pPrior);

  23468.   }

  23469.   return pNew;

  23470. }

  23471. 

  23472. /*

  23473. ** Populate the low-level memory allocation function pointers in

  23474. ** sqlite3GlobalConfig.m with pointers to the routines in this file.

  23475. */

  23476. SQLITE_PRIVATE void sqlite3MemSetDefault(void){

  23477.   static const sqlite3_mem_methods defaultMethods = {

  23478.      sqlite3MemMalloc,

  23479.      sqlite3MemFree,

  23480.      sqlite3MemRealloc,

  23481.      sqlite3MemSize,

  23482.      sqlite3MemRoundup,

  23483.      sqlite3MemInit,

  23484.      sqlite3MemShutdown,

  23485.      0

  23486.   };

  23487.   sqlite3_config(SQLITE_CONFIG_MALLOC, &defaultMethods);

  23488. }

  23489. 

  23490. /*

  23491. ** Set the "type" of an allocation.

  23492. */

  23493. SQLITE_PRIVATE void sqlite3MemdebugSetType(void *p, u8 eType){

  23494.   if( p && sqlite3GlobalConfig.m.xMalloc==sqlite3MemMalloc ){

  23495.     struct MemBlockHdr *pHdr;

  23496.     pHdr = sqlite3MemsysGetHeader(p);

  23497.     assert( pHdr->iForeGuard==FOREGUARD );

  23498.     pHdr->eType = eType;

  23499.   }

  23500. }

  23501. 

  23502. /*

  23503. ** Return TRUE if the mask of type in eType matches the type of the

  23504. ** allocation p.  Also return true if p==NULL.

  23505. **

  23506. ** This routine is designed for use within an assert() statement, to

  23507. ** verify the type of an allocation.  For example:

  23508. **

  23509. **     assert( sqlite3MemdebugHasType(p, MEMTYPE_HEAP) );

  23510. */

  23511. SQLITE_PRIVATE int sqlite3MemdebugHasType(void *p, u8 eType){

  23512.   int rc = 1;

  23513.   if( p && sqlite3GlobalConfig.m.xMalloc==sqlite3MemMalloc ){

  23514.     struct MemBlockHdr *pHdr;

  23515.     pHdr = sqlite3MemsysGetHeader(p);

  23516.     assert( pHdr->iForeGuard==FOREGUARD );         /* Allocation is valid */

  23517.     if( (pHdr->eType&eType)==0 ){

  23518.       rc = 0;

  23519.     }

  23520.   }

  23521.   return rc;

  23522. }

  23523. 

  23524. /*

  23525. ** Return TRUE if the mask of type in eType matches no bits of the type of the

  23526. ** allocation p.  Also return true if p==NULL.

  23527. **

  23528. ** This routine is designed for use within an assert() statement, to

  23529. ** verify the type of an allocation.  For example:

  23530. **

  23531. **     assert( sqlite3MemdebugNoType(p, MEMTYPE_LOOKASIDE) );

  23532. */

  23533. SQLITE_PRIVATE int sqlite3MemdebugNoType(void *p, u8 eType){

  23534.   int rc = 1;

  23535.   if( p && sqlite3GlobalConfig.m.xMalloc==sqlite3MemMalloc ){

  23536.     struct MemBlockHdr *pHdr;

  23537.     pHdr = sqlite3MemsysGetHeader(p);

  23538.     assert( pHdr->iForeGuard==FOREGUARD );         /* Allocation is valid */

  23539.     if( (pHdr->eType&eType)!=0 ){

  23540.       rc = 0;

  23541.     }

  23542.   }

  23543.   return rc;

  23544. }

  23545. 

  23546. /*

  23547. ** Set the number of backtrace levels kept for each allocation.

  23548. ** A value of zero turns off backtracing.  The number is always rounded

  23549. ** up to a multiple of 2.

  23550. */

  23551. SQLITE_PRIVATE void sqlite3MemdebugBacktrace(int depth){

  23552.   if( depth<0 ){ depth = 0; }

  23553.   if( depth>20 ){ depth = 20; }

  23554.   depth = (depth+1)&0xfe;

  23555.   mem.nBacktrace = depth;

  23556. }

  23557. 

  23558. SQLITE_PRIVATE void sqlite3MemdebugBacktraceCallback(void (*xBacktrace)(int, int, void **)){

  23559.   mem.xBacktrace = xBacktrace;

  23560. }

  23561. 

  23562. /*

  23563. ** Set the title string for subsequent allocations.

  23564. */

  23565. SQLITE_PRIVATE void sqlite3MemdebugSettitle(const char *zTitle){

  23566.   unsigned int n = sqlite3Strlen30(zTitle) + 1;

  23567.   sqlite3_mutex_enter(mem.mutex);

  23568.   if( n>=sizeof(mem.zTitle) ) n = sizeof(mem.zTitle)-1;

  23569.   memcpy(mem.zTitle, zTitle, n);

  23570.   mem.zTitle[n] = 0;

  23571.   mem.nTitle = ROUND8(n);

  23572.   sqlite3_mutex_leave(mem.mutex);

  23573. }

  23574. 

  23575. SQLITE_PRIVATE void sqlite3MemdebugSync(){

  23576.   struct MemBlockHdr *pHdr;

  23577.   for(pHdr=mem.pFirst; pHdr; pHdr=pHdr->pNext){

  23578.     void **pBt = (void**)pHdr;

  23579.     pBt -= pHdr->nBacktraceSlots;

  23580.     mem.xBacktrace((int)pHdr->iSize, pHdr->nBacktrace-1, &pBt[1]);

  23581.   }

  23582. }

  23583. 

  23584. /*

  23585. ** Open the file indicated and write a log of all unfreed memory 

  23586. ** allocations into that log.

  23587. */

  23588. SQLITE_PRIVATE void sqlite3MemdebugDump(const char *zFilename){

  23589.   FILE *out;

  23590.   struct MemBlockHdr *pHdr;

  23591.   void **pBt;

  23592.   int i;

  23593.   out = fopen(zFilename, "w");

  23594.   if( out==0 ){

  23595.     fprintf(stderr, "** Unable to output memory debug output log: %s **\n",

  23596.                     zFilename);

  23597.     return;

  23598.   }

  23599.   for(pHdr=mem.pFirst; pHdr; pHdr=pHdr->pNext){

  23600.     char *z = (char*)pHdr;

  23601.     z -= pHdr->nBacktraceSlots*sizeof(void*) + pHdr->nTitle;

  23602.     fprintf(out, "**** %lld bytes at %p from %s ****\n", 

  23603.             pHdr->iSize, &pHdr[1], pHdr->nTitle ? z : "???");

  23604.     if( pHdr->nBacktrace ){

  23605.       fflush(out);

  23606.       pBt = (void**)pHdr;

  23607.       pBt -= pHdr->nBacktraceSlots;

  23608.       backtrace_symbols_fd(pBt, pHdr->nBacktrace, fileno(out));

  23609.       fprintf(out, "\n");

  23610.     }

  23611.   }

  23612.   fprintf(out, "COUNTS:\n");

  23613.   for(i=0; i<NCSIZE-1; i++){

  23614.     if( mem.nAlloc[i] ){

  23615.       fprintf(out, "   %5d: %10d %10d %10d\n", 

  23616.             i*8, mem.nAlloc[i], mem.nCurrent[i], mem.mxCurrent[i]);

  23617.     }

  23618.   }

  23619.   if( mem.nAlloc[NCSIZE-1] ){

  23620.     fprintf(out, "   %5d: %10d %10d %10d\n",

  23621.              NCSIZE*8-8, mem.nAlloc[NCSIZE-1],

  23622.              mem.nCurrent[NCSIZE-1], mem.mxCurrent[NCSIZE-1]);

  23623.   }

  23624.   fclose(out);

  23625. }

  23626. 

  23627. /*

  23628. ** Return the number of times sqlite3MemMalloc() has been called.

  23629. */

  23630. SQLITE_PRIVATE int sqlite3MemdebugMallocCount(){

  23631.   int i;

  23632.   int nTotal = 0;

  23633.   for(i=0; i<NCSIZE; i++){

  23634.     nTotal += mem.nAlloc[i];

  23635.   }

  23636.   return nTotal;

  23637. }

  23638. 

  23639. 

  23640. #endif /* SQLITE_MEMDEBUG */

  23641. 

  23642. /************** End of mem2.c ************************************************/

  23643. /************** Begin file mem3.c ********************************************/

  23644. /*

  23645. ** 2007 October 14

  23646. **

  23647. ** The author disclaims copyright to this source code.  In place of

  23648. ** a legal notice, here is a blessing:

  23649. **

  23650. **    May you do good and not evil.

  23651. **    May you find forgiveness for yourself and forgive others.

  23652. **    May you share freely, never taking more than you give.

  23653. **

  23654. *************************************************************************

  23655. ** This file contains the C functions that implement a memory

  23656. ** allocation subsystem for use by SQLite. 

  23657. **

  23658. ** This version of the memory allocation subsystem omits all

  23659. ** use of malloc(). The SQLite user supplies a block of memory

  23660. ** before calling sqlite3_initialize() from which allocations

  23661. ** are made and returned by the xMalloc() and xRealloc() 

  23662. ** implementations. Once sqlite3_initialize() has been called,

  23663. ** the amount of memory available to SQLite is fixed and cannot

  23664. ** be changed.

  23665. **

  23666. ** This version of the memory allocation subsystem is included

  23667. ** in the build only if SQLITE_ENABLE_MEMSYS3 is defined.

  23668. */

  23669. /* #include "sqliteInt.h" */

  23670. 

  23671. /*

  23672. ** This version of the memory allocator is only built into the library

  23673. ** SQLITE_ENABLE_MEMSYS3 is defined. Defining this symbol does not

  23674. ** mean that the library will use a memory-pool by default, just that

  23675. ** it is available. The mempool allocator is activated by calling

  23676. ** sqlite3_config().

  23677. */

  23678. #ifdef SQLITE_ENABLE_MEMSYS3

  23679. 

  23680. /*

  23681. ** Maximum size (in Mem3Blocks) of a "small" chunk.

  23682. */

  23683. #define MX_SMALL 10

  23684. 

  23685. 

  23686. /*

  23687. ** Number of freelist hash slots

  23688. */

  23689. #define N_HASH  61

  23690. 

  23691. /*

  23692. ** A memory allocation (also called a "chunk") consists of two or 

  23693. ** more blocks where each block is 8 bytes.  The first 8 bytes are 

  23694. ** a header that is not returned to the user.

  23695. **

  23696. ** A chunk is two or more blocks that is either checked out or

  23697. ** free.  The first block has format u.hdr.  u.hdr.size4x is 4 times the

  23698. ** size of the allocation in blocks if the allocation is free.

  23699. ** The u.hdr.size4x&1 bit is true if the chunk is checked out and

  23700. ** false if the chunk is on the freelist.  The u.hdr.size4x&2 bit

  23701. ** is true if the previous chunk is checked out and false if the

  23702. ** previous chunk is free.  The u.hdr.prevSize field is the size of

  23703. ** the previous chunk in blocks if the previous chunk is on the

  23704. ** freelist. If the previous chunk is checked out, then

  23705. ** u.hdr.prevSize can be part of the data for that chunk and should

  23706. ** not be read or written.

  23707. **

  23708. ** We often identify a chunk by its index in mem3.aPool[].  When

  23709. ** this is done, the chunk index refers to the second block of

  23710. ** the chunk.  In this way, the first chunk has an index of 1.

  23711. ** A chunk index of 0 means "no such chunk" and is the equivalent

  23712. ** of a NULL pointer.

  23713. **

  23714. ** The second block of free chunks is of the form u.list.  The

  23715. ** two fields form a double-linked list of chunks of related sizes.

  23716. ** Pointers to the head of the list are stored in mem3.aiSmall[] 

  23717. ** for smaller chunks and mem3.aiHash[] for larger chunks.

  23718. **

  23719. ** The second block of a chunk is user data if the chunk is checked 

  23720. ** out.  If a chunk is checked out, the user data may extend into

  23721. ** the u.hdr.prevSize value of the following chunk.

  23722. */

  23723. typedef struct Mem3Block Mem3Block;

  23724. struct Mem3Block {

  23725.   union {

  23726.     struct {

  23727.       u32 prevSize;   /* Size of previous chunk in Mem3Block elements */

  23728.       u32 size4x;     /* 4x the size of current chunk in Mem3Block elements */

  23729.     } hdr;

  23730.     struct {

  23731.       u32 next;       /* Index in mem3.aPool[] of next free chunk */

  23732.       u32 prev;       /* Index in mem3.aPool[] of previous free chunk */

  23733.     } list;

  23734.   } u;

  23735. };

  23736. 

  23737. /*

  23738. ** All of the static variables used by this module are collected

  23739. ** into a single structure named "mem3".  This is to keep the

  23740. ** static variables organized and to reduce namespace pollution

  23741. ** when this module is combined with other in the amalgamation.

  23742. */

  23743. static SQLITE_WSD struct Mem3Global {

  23744.   /*

  23745.   ** Memory available for allocation. nPool is the size of the array

  23746.   ** (in Mem3Blocks) pointed to by aPool less 2.

  23747.   */

  23748.   u32 nPool;

  23749.   Mem3Block *aPool;

  23750. 

  23751.   /*

  23752.   ** True if we are evaluating an out-of-memory callback.

  23753.   */

  23754.   int alarmBusy;

  23755.   

  23756.   /*

  23757.   ** Mutex to control access to the memory allocation subsystem.

  23758.   */

  23759.   sqlite3_mutex *mutex;

  23760.   

  23761.   /*

  23762.   ** The minimum amount of free space that we have seen.

  23763.   */

  23764.   u32 mnMaster;

  23765. 

  23766.   /*

  23767.   ** iMaster is the index of the master chunk.  Most new allocations

  23768.   ** occur off of this chunk.  szMaster is the size (in Mem3Blocks)

  23769.   ** of the current master.  iMaster is 0 if there is not master chunk.

  23770.   ** The master chunk is not in either the aiHash[] or aiSmall[].

  23771.   */

  23772.   u32 iMaster;

  23773.   u32 szMaster;

  23774. 

  23775.   /*

  23776.   ** Array of lists of free blocks according to the block size 

  23777.   ** for smaller chunks, or a hash on the block size for larger

  23778.   ** chunks.

  23779.   */

  23780.   u32 aiSmall[MX_SMALL-1];   /* For sizes 2 through MX_SMALL, inclusive */

  23781.   u32 aiHash[N_HASH];        /* For sizes MX_SMALL+1 and larger */

  23782. } mem3 = { 97535575 };

  23783. 

  23784. #define mem3 GLOBAL(struct Mem3Global, mem3)

  23785. 

  23786. /*

  23787. ** Unlink the chunk at mem3.aPool[i] from list it is currently

  23788. ** on.  *pRoot is the list that i is a member of.

  23789. */

  23790. static void memsys3UnlinkFromList(u32 i, u32 *pRoot){

  23791.   u32 next = mem3.aPool[i].u.list.next;

  23792.   u32 prev = mem3.aPool[i].u.list.prev;

  23793.   assert( sqlite3_mutex_held(mem3.mutex) );

  23794.   if( prev==0 ){

  23795.     *pRoot = next;

  23796.   }else{

  23797.     mem3.aPool[prev].u.list.next = next;

  23798.   }

  23799.   if( next ){

  23800.     mem3.aPool[next].u.list.prev = prev;

  23801.   }

  23802.   mem3.aPool[i].u.list.next = 0;

  23803.   mem3.aPool[i].u.list.prev = 0;

  23804. }

  23805. 

  23806. /*

  23807. ** Unlink the chunk at index i from 

  23808. ** whatever list is currently a member of.

  23809. */

  23810. static void memsys3Unlink(u32 i){

  23811.   u32 size, hash;

  23812.   assert( sqlite3_mutex_held(mem3.mutex) );

  23813.   assert( (mem3.aPool[i-1].u.hdr.size4x & 1)==0 );

  23814.   assert( i>=1 );

  23815.   size = mem3.aPool[i-1].u.hdr.size4x/4;

  23816.   assert( size==mem3.aPool[i+size-1].u.hdr.prevSize );

  23817.   assert( size>=2 );

  23818.   if( size <= MX_SMALL ){

  23819.     memsys3UnlinkFromList(i, &mem3.aiSmall[size-2]);

  23820.   }else{

  23821.     hash = size % N_HASH;

  23822.     memsys3UnlinkFromList(i, &mem3.aiHash[hash]);

  23823.   }

  23824. }

  23825. 

  23826. /*

  23827. ** Link the chunk at mem3.aPool[i] so that is on the list rooted

  23828. ** at *pRoot.

  23829. */

  23830. static void memsys3LinkIntoList(u32 i, u32 *pRoot){

  23831.   assert( sqlite3_mutex_held(mem3.mutex) );

  23832.   mem3.aPool[i].u.list.next = *pRoot;

  23833.   mem3.aPool[i].u.list.prev = 0;

  23834.   if( *pRoot ){

  23835.     mem3.aPool[*pRoot].u.list.prev = i;

  23836.   }

  23837.   *pRoot = i;

  23838. }

  23839. 

  23840. /*

  23841. ** Link the chunk at index i into either the appropriate

  23842. ** small chunk list, or into the large chunk hash table.

  23843. */

  23844. static void memsys3Link(u32 i){

  23845.   u32 size, hash;

  23846.   assert( sqlite3_mutex_held(mem3.mutex) );

  23847.   assert( i>=1 );

  23848.   assert( (mem3.aPool[i-1].u.hdr.size4x & 1)==0 );

  23849.   size = mem3.aPool[i-1].u.hdr.size4x/4;

  23850.   assert( size==mem3.aPool[i+size-1].u.hdr.prevSize );

  23851.   assert( size>=2 );

  23852.   if( size <= MX_SMALL ){

  23853.     memsys3LinkIntoList(i, &mem3.aiSmall[size-2]);

  23854.   }else{

  23855.     hash = size % N_HASH;

  23856.     memsys3LinkIntoList(i, &mem3.aiHash[hash]);

  23857.   }

  23858. }

  23859. 

  23860. /*

  23861. ** If the STATIC_MEM mutex is not already held, obtain it now. The mutex

  23862. ** will already be held (obtained by code in malloc.c) if

  23863. ** sqlite3GlobalConfig.bMemStat is true.

  23864. */

  23865. static void memsys3Enter(void){

  23866.   if( sqlite3GlobalConfig.bMemstat==0 && mem3.mutex==0 ){

  23867.     mem3.mutex = sqlite3MutexAlloc(SQLITE_MUTEX_STATIC_MEM);

  23868.   }

  23869.   sqlite3_mutex_enter(mem3.mutex);

  23870. }

  23871. static void memsys3Leave(void){

  23872.   sqlite3_mutex_leave(mem3.mutex);

  23873. }

  23874. 

  23875. /*

  23876. ** Called when we are unable to satisfy an allocation of nBytes.

  23877. */

  23878. static void memsys3OutOfMemory(int nByte){

  23879.   if( !mem3.alarmBusy ){

  23880.     mem3.alarmBusy = 1;

  23881.     assert( sqlite3_mutex_held(mem3.mutex) );

  23882.     sqlite3_mutex_leave(mem3.mutex);

  23883.     sqlite3_release_memory(nByte);

  23884.     sqlite3_mutex_enter(mem3.mutex);

  23885.     mem3.alarmBusy = 0;

  23886.   }

  23887. }

  23888. 

  23889. 

  23890. /*

  23891. ** Chunk i is a free chunk that has been unlinked.  Adjust its 

  23892. ** size parameters for check-out and return a pointer to the 

  23893. ** user portion of the chunk.

  23894. */

  23895. static void *memsys3Checkout(u32 i, u32 nBlock){

  23896.   u32 x;

  23897.   assert( sqlite3_mutex_held(mem3.mutex) );

  23898.   assert( i>=1 );

  23899.   assert( mem3.aPool[i-1].u.hdr.size4x/4==nBlock );

  23900.   assert( mem3.aPool[i+nBlock-1].u.hdr.prevSize==nBlock );

  23901.   x = mem3.aPool[i-1].u.hdr.size4x;

  23902.   mem3.aPool[i-1].u.hdr.size4x = nBlock*4 | 1 | (x&2);

  23903.   mem3.aPool[i+nBlock-1].u.hdr.prevSize = nBlock;

  23904.   mem3.aPool[i+nBlock-1].u.hdr.size4x |= 2;

  23905.   return &mem3.aPool[i];

  23906. }

  23907. 

  23908. /*

  23909. ** Carve a piece off of the end of the mem3.iMaster free chunk.

  23910. ** Return a pointer to the new allocation.  Or, if the master chunk

  23911. ** is not large enough, return 0.

  23912. */

  23913. static void *memsys3FromMaster(u32 nBlock){

  23914.   assert( sqlite3_mutex_held(mem3.mutex) );

  23915.   assert( mem3.szMaster>=nBlock );

  23916.   if( nBlock>=mem3.szMaster-1 ){

  23917.     /* Use the entire master */

  23918.     void *p = memsys3Checkout(mem3.iMaster, mem3.szMaster);

  23919.     mem3.iMaster = 0;

  23920.     mem3.szMaster = 0;

  23921.     mem3.mnMaster = 0;

  23922.     return p;

  23923.   }else{

  23924.     /* Split the master block.  Return the tail. */

  23925.     u32 newi, x;

  23926.     newi = mem3.iMaster + mem3.szMaster - nBlock;

  23927.     assert( newi > mem3.iMaster+1 );

  23928.     mem3.aPool[mem3.iMaster+mem3.szMaster-1].u.hdr.prevSize = nBlock;

  23929.     mem3.aPool[mem3.iMaster+mem3.szMaster-1].u.hdr.size4x |= 2;

  23930.     mem3.aPool[newi-1].u.hdr.size4x = nBlock*4 + 1;

  23931.     mem3.szMaster -= nBlock;

  23932.     mem3.aPool[newi-1].u.hdr.prevSize = mem3.szMaster;

  23933.     x = mem3.aPool[mem3.iMaster-1].u.hdr.size4x & 2;

  23934.     mem3.aPool[mem3.iMaster-1].u.hdr.size4x = mem3.szMaster*4 | x;

  23935.     if( mem3.szMaster < mem3.mnMaster ){

  23936.       mem3.mnMaster = mem3.szMaster;

  23937.     }

  23938.     return (void*)&mem3.aPool[newi];

  23939.   }

  23940. }

  23941. 

  23942. /*

  23943. ** *pRoot is the head of a list of free chunks of the same size

  23944. ** or same size hash.  In other words, *pRoot is an entry in either

  23945. ** mem3.aiSmall[] or mem3.aiHash[].  

  23946. **

  23947. ** This routine examines all entries on the given list and tries

  23948. ** to coalesce each entries with adjacent free chunks.  

  23949. **

  23950. ** If it sees a chunk that is larger than mem3.iMaster, it replaces 

  23951. ** the current mem3.iMaster with the new larger chunk.  In order for

  23952. ** this mem3.iMaster replacement to work, the master chunk must be

  23953. ** linked into the hash tables.  That is not the normal state of

  23954. ** affairs, of course.  The calling routine must link the master

  23955. ** chunk before invoking this routine, then must unlink the (possibly

  23956. ** changed) master chunk once this routine has finished.

  23957. */

  23958. static void memsys3Merge(u32 *pRoot){

  23959.   u32 iNext, prev, size, i, x;

  23960. 

  23961.   assert( sqlite3_mutex_held(mem3.mutex) );

  23962.   for(i=*pRoot; i>0; i=iNext){

  23963.     iNext = mem3.aPool[i].u.list.next;

  23964.     size = mem3.aPool[i-1].u.hdr.size4x;

  23965.     assert( (size&1)==0 );

  23966.     if( (size&2)==0 ){

  23967.       memsys3UnlinkFromList(i, pRoot);

  23968.       assert( i > mem3.aPool[i-1].u.hdr.prevSize );

  23969.       prev = i - mem3.aPool[i-1].u.hdr.prevSize;

  23970.       if( prev==iNext ){

  23971.         iNext = mem3.aPool[prev].u.list.next;

  23972.       }

  23973.       memsys3Unlink(prev);

  23974.       size = i + size/4 - prev;

  23975.       x = mem3.aPool[prev-1].u.hdr.size4x & 2;

  23976.       mem3.aPool[prev-1].u.hdr.size4x = size*4 | x;

  23977.       mem3.aPool[prev+size-1].u.hdr.prevSize = size;

  23978.       memsys3Link(prev);

  23979.       i = prev;

  23980.     }else{

  23981.       size /= 4;

  23982.     }

  23983.     if( size>mem3.szMaster ){

  23984.       mem3.iMaster = i;

  23985.       mem3.szMaster = size;

  23986.     }

  23987.   }

  23988. }

  23989. 

  23990. /*

  23991. ** Return a block of memory of at least nBytes in size.

  23992. ** Return NULL if unable.

  23993. **

  23994. ** This function assumes that the necessary mutexes, if any, are

  23995. ** already held by the caller. Hence "Unsafe".

  23996. */

  23997. static void *memsys3MallocUnsafe(int nByte){

  23998.   u32 i;

  23999.   u32 nBlock;

  24000.   u32 toFree;

  24001. 

  24002.   assert( sqlite3_mutex_held(mem3.mutex) );

  24003.   assert( sizeof(Mem3Block)==8 );

  24004.   if( nByte<=12 ){

  24005.     nBlock = 2;

  24006.   }else{

  24007.     nBlock = (nByte + 11)/8;

  24008.   }

  24009.   assert( nBlock>=2 );

  24010. 

  24011.   /* STEP 1:

  24012.   ** Look for an entry of the correct size in either the small

  24013.   ** chunk table or in the large chunk hash table.  This is

  24014.   ** successful most of the time (about 9 times out of 10).

  24015.   */

  24016.   if( nBlock <= MX_SMALL ){

  24017.     i = mem3.aiSmall[nBlock-2];

  24018.     if( i>0 ){

  24019.       memsys3UnlinkFromList(i, &mem3.aiSmall[nBlock-2]);

  24020.       return memsys3Checkout(i, nBlock);

  24021.     }

  24022.   }else{

  24023.     int hash = nBlock % N_HASH;

  24024.     for(i=mem3.aiHash[hash]; i>0; i=mem3.aPool[i].u.list.next){

  24025.       if( mem3.aPool[i-1].u.hdr.size4x/4==nBlock ){

  24026.         memsys3UnlinkFromList(i, &mem3.aiHash[hash]);

  24027.         return memsys3Checkout(i, nBlock);

  24028.       }

  24029.     }

  24030.   }

  24031. 

  24032.   /* STEP 2:

  24033.   ** Try to satisfy the allocation by carving a piece off of the end

  24034.   ** of the master chunk.  This step usually works if step 1 fails.

  24035.   */

  24036.   if( mem3.szMaster>=nBlock ){

  24037.     return memsys3FromMaster(nBlock);

  24038.   }

  24039. 

  24040. 

  24041.   /* STEP 3:  

  24042.   ** Loop through the entire memory pool.  Coalesce adjacent free

  24043.   ** chunks.  Recompute the master chunk as the largest free chunk.

  24044.   ** Then try again to satisfy the allocation by carving a piece off

  24045.   ** of the end of the master chunk.  This step happens very

  24046.   ** rarely (we hope!)

  24047.   */

  24048.   for(toFree=nBlock*16; toFree<(mem3.nPool*16); toFree *= 2){

  24049.     memsys3OutOfMemory(toFree);

  24050.     if( mem3.iMaster ){

  24051.       memsys3Link(mem3.iMaster);

  24052.       mem3.iMaster = 0;

  24053.       mem3.szMaster = 0;

  24054.     }

  24055.     for(i=0; i<N_HASH; i++){

  24056.       memsys3Merge(&mem3.aiHash[i]);

  24057.     }

  24058.     for(i=0; i<MX_SMALL-1; i++){

  24059.       memsys3Merge(&mem3.aiSmall[i]);

  24060.     }

  24061.     if( mem3.szMaster ){

  24062.       memsys3Unlink(mem3.iMaster);

  24063.       if( mem3.szMaster>=nBlock ){

  24064.         return memsys3FromMaster(nBlock);

  24065.       }

  24066.     }

  24067.   }

  24068. 

  24069.   /* If none of the above worked, then we fail. */

  24070.   return 0;

  24071. }

  24072. 

  24073. /*

  24074. ** Free an outstanding memory allocation.

  24075. **

  24076. ** This function assumes that the necessary mutexes, if any, are

  24077. ** already held by the caller. Hence "Unsafe".

  24078. */

  24079. static void memsys3FreeUnsafe(void *pOld){

  24080.   Mem3Block *p = (Mem3Block*)pOld;

  24081.   int i;

  24082.   u32 size, x;

  24083.   assert( sqlite3_mutex_held(mem3.mutex) );

  24084.   assert( p>mem3.aPool && p<&mem3.aPool[mem3.nPool] );

  24085.   i = p - mem3.aPool;

  24086.   assert( (mem3.aPool[i-1].u.hdr.size4x&1)==1 );

  24087.   size = mem3.aPool[i-1].u.hdr.size4x/4;

  24088.   assert( i+size<=mem3.nPool+1 );

  24089.   mem3.aPool[i-1].u.hdr.size4x &= ~1;

  24090.   mem3.aPool[i+size-1].u.hdr.prevSize = size;

  24091.   mem3.aPool[i+size-1].u.hdr.size4x &= ~2;

  24092.   memsys3Link(i);

  24093. 

  24094.   /* Try to expand the master using the newly freed chunk */

  24095.   if( mem3.iMaster ){

  24096.     while( (mem3.aPool[mem3.iMaster-1].u.hdr.size4x&2)==0 ){

  24097.       size = mem3.aPool[mem3.iMaster-1].u.hdr.prevSize;

  24098.       mem3.iMaster -= size;

  24099.       mem3.szMaster += size;

  24100.       memsys3Unlink(mem3.iMaster);

  24101.       x = mem3.aPool[mem3.iMaster-1].u.hdr.size4x & 2;

  24102.       mem3.aPool[mem3.iMaster-1].u.hdr.size4x = mem3.szMaster*4 | x;

  24103.       mem3.aPool[mem3.iMaster+mem3.szMaster-1].u.hdr.prevSize = mem3.szMaster;

  24104.     }

  24105.     x = mem3.aPool[mem3.iMaster-1].u.hdr.size4x & 2;

  24106.     while( (mem3.aPool[mem3.iMaster+mem3.szMaster-1].u.hdr.size4x&1)==0 ){

  24107.       memsys3Unlink(mem3.iMaster+mem3.szMaster);

  24108.       mem3.szMaster += mem3.aPool[mem3.iMaster+mem3.szMaster-1].u.hdr.size4x/4;

  24109.       mem3.aPool[mem3.iMaster-1].u.hdr.size4x = mem3.szMaster*4 | x;

  24110.       mem3.aPool[mem3.iMaster+mem3.szMaster-1].u.hdr.prevSize = mem3.szMaster;

  24111.     }

  24112.   }

  24113. }

  24114. 

  24115. /*

  24116. ** Return the size of an outstanding allocation, in bytes.  The

  24117. ** size returned omits the 8-byte header overhead.  This only

  24118. ** works for chunks that are currently checked out.

  24119. */

  24120. static int memsys3Size(void *p){

  24121.   Mem3Block *pBlock;

  24122.   assert( p!=0 );

  24123.   pBlock = (Mem3Block*)p;

  24124.   assert( (pBlock[-1].u.hdr.size4x&1)!=0 );

  24125.   return (pBlock[-1].u.hdr.size4x&~3)*2 - 4;

  24126. }

  24127. 

  24128. /*

  24129. ** Round up a request size to the next valid allocation size.

  24130. */

  24131. static int memsys3Roundup(int n){

  24132.   if( n<=12 ){

  24133.     return 12;

  24134.   }else{

  24135.     return ((n+11)&~7) - 4;

  24136.   }

  24137. }

  24138. 

  24139. /*

  24140. ** Allocate nBytes of memory.

  24141. */

  24142. static void *memsys3Malloc(int nBytes){

  24143.   sqlite3_int64 *p;

  24144.   assert( nBytes>0 );          /* malloc.c filters out 0 byte requests */

  24145.   memsys3Enter();

  24146.   p = memsys3MallocUnsafe(nBytes);

  24147.   memsys3Leave();

  24148.   return (void*)p; 

  24149. }

  24150. 

  24151. /*

  24152. ** Free memory.

  24153. */

  24154. static void memsys3Free(void *pPrior){

  24155.   assert( pPrior );

  24156.   memsys3Enter();

  24157.   memsys3FreeUnsafe(pPrior);

  24158.   memsys3Leave();

  24159. }

  24160. 

  24161. /*

  24162. ** Change the size of an existing memory allocation

  24163. */

  24164. static void *memsys3Realloc(void *pPrior, int nBytes){

  24165.   int nOld;

  24166.   void *p;

  24167.   if( pPrior==0 ){

  24168.     return sqlite3_malloc(nBytes);

  24169.   }

  24170.   if( nBytes<=0 ){

  24171.     sqlite3_free(pPrior);

  24172.     return 0;

  24173.   }

  24174.   nOld = memsys3Size(pPrior);

  24175.   if( nBytes<=nOld && nBytes>=nOld-128 ){

  24176.     return pPrior;

  24177.   }

  24178.   memsys3Enter();

  24179.   p = memsys3MallocUnsafe(nBytes);

  24180.   if( p ){

  24181.     if( nOld<nBytes ){

  24182.       memcpy(p, pPrior, nOld);

  24183.     }else{

  24184.       memcpy(p, pPrior, nBytes);

  24185.     }

  24186.     memsys3FreeUnsafe(pPrior);

  24187.   }

  24188.   memsys3Leave();

  24189.   return p;

  24190. }

  24191. 

  24192. /*

  24193. ** Initialize this module.

  24194. */

  24195. static int memsys3Init(void *NotUsed){

  24196.   UNUSED_PARAMETER(NotUsed);

  24197.   if( !sqlite3GlobalConfig.pHeap ){

  24198.     return SQLITE_ERROR;

  24199.   }

  24200. 

  24201.   /* Store a pointer to the memory block in global structure mem3. */

  24202.   assert( sizeof(Mem3Block)==8 );

  24203.   mem3.aPool = (Mem3Block *)sqlite3GlobalConfig.pHeap;

  24204.   mem3.nPool = (sqlite3GlobalConfig.nHeap / sizeof(Mem3Block)) - 2;

  24205. 

  24206.   /* Initialize the master block. */

  24207.   mem3.szMaster = mem3.nPool;

  24208.   mem3.mnMaster = mem3.szMaster;

  24209.   mem3.iMaster = 1;

  24210.   mem3.aPool[0].u.hdr.size4x = (mem3.szMaster<<2) + 2;

  24211.   mem3.aPool[mem3.nPool].u.hdr.prevSize = mem3.nPool;

  24212.   mem3.aPool[mem3.nPool].u.hdr.size4x = 1;

  24213. 

  24214.   return SQLITE_OK;

  24215. }

  24216. 

  24217. /*

  24218. ** Deinitialize this module.

  24219. */

  24220. static void memsys3Shutdown(void *NotUsed){

  24221.   UNUSED_PARAMETER(NotUsed);

  24222.   mem3.mutex = 0;

  24223.   return;

  24224. }

  24225. 

  24226. 

  24227. 

  24228. /*

  24229. ** Open the file indicated and write a log of all unfreed memory 

  24230. ** allocations into that log.

  24231. */

  24232. SQLITE_PRIVATE void sqlite3Memsys3Dump(const char *zFilename){

  24233. #ifdef SQLITE_DEBUG

  24234.   FILE *out;

  24235.   u32 i, j;

  24236.   u32 size;

  24237.   if( zFilename==0 || zFilename[0]==0 ){

  24238.     out = stdout;

  24239.   }else{

  24240.     out = fopen(zFilename, "w");

  24241.     if( out==0 ){

  24242.       fprintf(stderr, "** Unable to output memory debug output log: %s **\n",

  24243.                       zFilename);

  24244.       return;

  24245.     }

  24246.   }

  24247.   memsys3Enter();

  24248.   fprintf(out, "CHUNKS:\n");

  24249.   for(i=1; i<=mem3.nPool; i+=size/4){

  24250.     size = mem3.aPool[i-1].u.hdr.size4x;

  24251.     if( size/4<=1 ){

  24252.       fprintf(out, "%p size error\n", &mem3.aPool[i]);

  24253.       assert( 0 );

  24254.       break;

  24255.     }

  24256.     if( (size&1)==0 && mem3.aPool[i+size/4-1].u.hdr.prevSize!=size/4 ){

  24257.       fprintf(out, "%p tail size does not match\n", &mem3.aPool[i]);

  24258.       assert( 0 );

  24259.       break;

  24260.     }

  24261.     if( ((mem3.aPool[i+size/4-1].u.hdr.size4x&2)>>1)!=(size&1) ){

  24262.       fprintf(out, "%p tail checkout bit is incorrect\n", &mem3.aPool[i]);

  24263.       assert( 0 );

  24264.       break;

  24265.     }

  24266.     if( size&1 ){

  24267.       fprintf(out, "%p %6d bytes checked out\n", &mem3.aPool[i], (size/4)*8-8);

  24268.     }else{

  24269.       fprintf(out, "%p %6d bytes free%s\n", &mem3.aPool[i], (size/4)*8-8,

  24270.                   i==mem3.iMaster ? " **master**" : "");

  24271.     }

  24272.   }

  24273.   for(i=0; i<MX_SMALL-1; i++){

  24274.     if( mem3.aiSmall[i]==0 ) continue;

  24275.     fprintf(out, "small(%2d):", i);

  24276.     for(j = mem3.aiSmall[i]; j>0; j=mem3.aPool[j].u.list.next){

  24277.       fprintf(out, " %p(%d)", &mem3.aPool[j],

  24278.               (mem3.aPool[j-1].u.hdr.size4x/4)*8-8);

  24279.     }

  24280.     fprintf(out, "\n"); 

  24281.   }

  24282.   for(i=0; i<N_HASH; i++){

  24283.     if( mem3.aiHash[i]==0 ) continue;

  24284.     fprintf(out, "hash(%2d):", i);

  24285.     for(j = mem3.aiHash[i]; j>0; j=mem3.aPool[j].u.list.next){

  24286.       fprintf(out, " %p(%d)", &mem3.aPool[j],

  24287.               (mem3.aPool[j-1].u.hdr.size4x/4)*8-8);

  24288.     }

  24289.     fprintf(out, "\n"); 

  24290.   }

  24291.   fprintf(out, "master=%d\n", mem3.iMaster);

  24292.   fprintf(out, "nowUsed=%d\n", mem3.nPool*8 - mem3.szMaster*8);

  24293.   fprintf(out, "mxUsed=%d\n", mem3.nPool*8 - mem3.mnMaster*8);

  24294.   sqlite3_mutex_leave(mem3.mutex);

  24295.   if( out==stdout ){

  24296.     fflush(stdout);

  24297.   }else{

  24298.     fclose(out);

  24299.   }

  24300. #else

  24301.   UNUSED_PARAMETER(zFilename);

  24302. #endif

  24303. }

  24304. 

  24305. /*

  24306. ** This routine is the only routine in this file with external 

  24307. ** linkage.

  24308. **

  24309. ** Populate the low-level memory allocation function pointers in

  24310. ** sqlite3GlobalConfig.m with pointers to the routines in this file. The

  24311. ** arguments specify the block of memory to manage.

  24312. **

  24313. ** This routine is only called by sqlite3_config(), and therefore

  24314. ** is not required to be threadsafe (it is not).

  24315. */

  24316. SQLITE_PRIVATE const sqlite3_mem_methods *sqlite3MemGetMemsys3(void){

  24317.   static const sqlite3_mem_methods mempoolMethods = {

  24318.      memsys3Malloc,

  24319.      memsys3Free,

  24320.      memsys3Realloc,

  24321.      memsys3Size,

  24322.      memsys3Roundup,

  24323.      memsys3Init,

  24324.      memsys3Shutdown,

  24325.      0

  24326.   };

  24327.   return &mempoolMethods;

  24328. }

  24329. 

  24330. #endif /* SQLITE_ENABLE_MEMSYS3 */

  24331. 

  24332. /************** End of mem3.c ************************************************/

  24333. /************** Begin file mem5.c ********************************************/

  24334. /*

  24335. ** 2007 October 14

  24336. **

  24337. ** The author disclaims copyright to this source code.  In place of

  24338. ** a legal notice, here is a blessing:

  24339. **

  24340. **    May you do good and not evil.

  24341. **    May you find forgiveness for yourself and forgive others.

  24342. **    May you share freely, never taking more than you give.

  24343. **

  24344. *************************************************************************

  24345. ** This file contains the C functions that implement a memory

  24346. ** allocation subsystem for use by SQLite. 

  24347. **

  24348. ** This version of the memory allocation subsystem omits all

  24349. ** use of malloc(). The application gives SQLite a block of memory

  24350. ** before calling sqlite3_initialize() from which allocations

  24351. ** are made and returned by the xMalloc() and xRealloc() 

  24352. ** implementations. Once sqlite3_initialize() has been called,

  24353. ** the amount of memory available to SQLite is fixed and cannot

  24354. ** be changed.

  24355. **

  24356. ** This version of the memory allocation subsystem is included

  24357. ** in the build only if SQLITE_ENABLE_MEMSYS5 is defined.

  24358. **

  24359. ** This memory allocator uses the following algorithm:

  24360. **

  24361. **   1.  All memory allocation sizes are rounded up to a power of 2.

  24362. **

  24363. **   2.  If two adjacent free blocks are the halves of a larger block,

  24364. **       then the two blocks are coalesced into the single larger block.

  24365. **

  24366. **   3.  New memory is allocated from the first available free block.

  24367. **

  24368. ** This algorithm is described in: J. M. Robson. "Bounds for Some Functions

  24369. ** Concerning Dynamic Storage Allocation". Journal of the Association for

  24370. ** Computing Machinery, Volume 21, Number 8, July 1974, pages 491-499.

  24371. ** 

  24372. ** Let n be the size of the largest allocation divided by the minimum

  24373. ** allocation size (after rounding all sizes up to a power of 2.)  Let M

  24374. ** be the maximum amount of memory ever outstanding at one time.  Let

  24375. ** N be the total amount of memory available for allocation.  Robson

  24376. ** proved that this memory allocator will never breakdown due to 

  24377. ** fragmentation as long as the following constraint holds:

  24378. **

  24379. **      N >=  M*(1 + log2(n)/2) - n + 1

  24380. **

  24381. ** The sqlite3_status() logic tracks the maximum values of n and M so

  24382. ** that an application can, at any time, verify this constraint.

  24383. */

  24384. /* #include "sqliteInt.h" */

  24385. 

  24386. /*

  24387. ** This version of the memory allocator is used only when 

  24388. ** SQLITE_ENABLE_MEMSYS5 is defined.

  24389. */

  24390. #ifdef SQLITE_ENABLE_MEMSYS5

  24391. 

  24392. /*

  24393. ** A minimum allocation is an instance of the following structure.

  24394. ** Larger allocations are an array of these structures where the

  24395. ** size of the array is a power of 2.

  24396. **

  24397. ** The size of this object must be a power of two.  That fact is

  24398. ** verified in memsys5Init().

  24399. */

  24400. typedef struct Mem5Link Mem5Link;

  24401. struct Mem5Link {

  24402.   int next;       /* Index of next free chunk */

  24403.   int prev;       /* Index of previous free chunk */

  24404. };

  24405. 

  24406. /*

  24407. ** Maximum size of any allocation is ((1<<LOGMAX)*mem5.szAtom). Since

  24408. ** mem5.szAtom is always at least 8 and 32-bit integers are used,

  24409. ** it is not actually possible to reach this limit.

  24410. */

  24411. #define LOGMAX 30

  24412. 

  24413. /*

  24414. ** Masks used for mem5.aCtrl[] elements.

  24415. */

  24416. #define CTRL_LOGSIZE  0x1f    /* Log2 Size of this block */

  24417. #define CTRL_FREE     0x20    /* True if not checked out */

  24418. 

  24419. /*

  24420. ** All of the static variables used by this module are collected

  24421. ** into a single structure named "mem5".  This is to keep the

  24422. ** static variables organized and to reduce namespace pollution

  24423. ** when this module is combined with other in the amalgamation.

  24424. */

  24425. static SQLITE_WSD struct Mem5Global {

  24426.   /*

  24427.   ** Memory available for allocation

  24428.   */

  24429.   int szAtom;      /* Smallest possible allocation in bytes */

  24430.   int nBlock;      /* Number of szAtom sized blocks in zPool */

  24431.   u8 *zPool;       /* Memory available to be allocated */

  24432.   

  24433.   /*

  24434.   ** Mutex to control access to the memory allocation subsystem.

  24435.   */

  24436.   sqlite3_mutex *mutex;

  24437. 

  24438. #if defined(SQLITE_DEBUG) || defined(SQLITE_TEST)

  24439.   /*

  24440.   ** Performance statistics

  24441.   */

  24442.   u64 nAlloc;         /* Total number of calls to malloc */

  24443.   u64 totalAlloc;     /* Total of all malloc calls - includes internal frag */

  24444.   u64 totalExcess;    /* Total internal fragmentation */

  24445.   u32 currentOut;     /* Current checkout, including internal fragmentation */

  24446.   u32 currentCount;   /* Current number of distinct checkouts */

  24447.   u32 maxOut;         /* Maximum instantaneous currentOut */

  24448.   u32 maxCount;       /* Maximum instantaneous currentCount */

  24449.   u32 maxRequest;     /* Largest allocation (exclusive of internal frag) */

  24450. #endif

  24451.   

  24452.   /*

  24453.   ** Lists of free blocks.  aiFreelist[0] is a list of free blocks of

  24454.   ** size mem5.szAtom.  aiFreelist[1] holds blocks of size szAtom*2.

  24455.   ** aiFreelist[2] holds free blocks of size szAtom*4.  And so forth.

  24456.   */

  24457.   int aiFreelist[LOGMAX+1];

  24458. 

  24459.   /*

  24460.   ** Space for tracking which blocks are checked out and the size

  24461.   ** of each block.  One byte per block.

  24462.   */

  24463.   u8 *aCtrl;

  24464. 

  24465. } mem5;

  24466. 

  24467. /*

  24468. ** Access the static variable through a macro for SQLITE_OMIT_WSD.

  24469. */

  24470. #define mem5 GLOBAL(struct Mem5Global, mem5)

  24471. 

  24472. /*

  24473. ** Assuming mem5.zPool is divided up into an array of Mem5Link

  24474. ** structures, return a pointer to the idx-th such link.

  24475. */

  24476. #define MEM5LINK(idx) ((Mem5Link *)(&mem5.zPool[(idx)*mem5.szAtom]))

  24477. 

  24478. /*

  24479. ** Unlink the chunk at mem5.aPool[i] from list it is currently

  24480. ** on.  It should be found on mem5.aiFreelist[iLogsize].

  24481. */

  24482. static void memsys5Unlink(int i, int iLogsize){

  24483.   int next, prev;

  24484.   assert( i>=0 && i<mem5.nBlock );

  24485.   assert( iLogsize>=0 && iLogsize<=LOGMAX );

  24486.   assert( (mem5.aCtrl[i] & CTRL_LOGSIZE)==iLogsize );

  24487. 

  24488.   next = MEM5LINK(i)->next;

  24489.   prev = MEM5LINK(i)->prev;

  24490.   if( prev<0 ){

  24491.     mem5.aiFreelist[iLogsize] = next;

  24492.   }else{

  24493.     MEM5LINK(prev)->next = next;

  24494.   }

  24495.   if( next>=0 ){

  24496.     MEM5LINK(next)->prev = prev;

  24497.   }

  24498. }

  24499. 

  24500. /*

  24501. ** Link the chunk at mem5.aPool[i] so that is on the iLogsize

  24502. ** free list.

  24503. */

  24504. static void memsys5Link(int i, int iLogsize){

  24505.   int x;

  24506.   assert( sqlite3_mutex_held(mem5.mutex) );

  24507.   assert( i>=0 && i<mem5.nBlock );

  24508.   assert( iLogsize>=0 && iLogsize<=LOGMAX );

  24509.   assert( (mem5.aCtrl[i] & CTRL_LOGSIZE)==iLogsize );

  24510. 

  24511.   x = MEM5LINK(i)->next = mem5.aiFreelist[iLogsize];

  24512.   MEM5LINK(i)->prev = -1;

  24513.   if( x>=0 ){

  24514.     assert( x<mem5.nBlock );

  24515.     MEM5LINK(x)->prev = i;

  24516.   }

  24517.   mem5.aiFreelist[iLogsize] = i;

  24518. }

  24519. 

  24520. /*

  24521. ** Obtain or release the mutex needed to access global data structures.

  24522. */

  24523. static void memsys5Enter(void){

  24524.   sqlite3_mutex_enter(mem5.mutex);

  24525. }

  24526. static void memsys5Leave(void){

  24527.   sqlite3_mutex_leave(mem5.mutex);

  24528. }

  24529. 

  24530. /*

  24531. ** Return the size of an outstanding allocation, in bytes.

  24532. ** This only works for chunks that are currently checked out.

  24533. */

  24534. static int memsys5Size(void *p){

  24535.   int iSize, i;

  24536.   assert( p!=0 );

  24537.   i = (int)(((u8 *)p-mem5.zPool)/mem5.szAtom);

  24538.   assert( i>=0 && i<mem5.nBlock );

  24539.   iSize = mem5.szAtom * (1 << (mem5.aCtrl[i]&CTRL_LOGSIZE));

  24540.   return iSize;

  24541. }

  24542. 

  24543. /*

  24544. ** Return a block of memory of at least nBytes in size.

  24545. ** Return NULL if unable.  Return NULL if nBytes==0.

  24546. **

  24547. ** The caller guarantees that nByte is positive.

  24548. **

  24549. ** The caller has obtained a mutex prior to invoking this

  24550. ** routine so there is never any chance that two or more

  24551. ** threads can be in this routine at the same time.

  24552. */

  24553. static void *memsys5MallocUnsafe(int nByte){

  24554.   int i;           /* Index of a mem5.aPool[] slot */

  24555.   int iBin;        /* Index into mem5.aiFreelist[] */

  24556.   int iFullSz;     /* Size of allocation rounded up to power of 2 */

  24557.   int iLogsize;    /* Log2 of iFullSz/POW2_MIN */

  24558. 

  24559.   /* nByte must be a positive */

  24560.   assert( nByte>0 );

  24561. 

  24562.   /* No more than 1GiB per allocation */

  24563.   if( nByte > 0x40000000 ) return 0;

  24564. 

  24565. #if defined(SQLITE_DEBUG) || defined(SQLITE_TEST)

  24566.   /* Keep track of the maximum allocation request.  Even unfulfilled

  24567.   ** requests are counted */

  24568.   if( (u32)nByte>mem5.maxRequest ){

  24569.     mem5.maxRequest = nByte;

  24570.   }

  24571. #endif

  24572. 

  24573. 

  24574.   /* Round nByte up to the next valid power of two */

  24575.   for(iFullSz=mem5.szAtom,iLogsize=0; iFullSz<nByte; iFullSz*=2,iLogsize++){}

  24576. 

  24577.   /* Make sure mem5.aiFreelist[iLogsize] contains at least one free

  24578.   ** block.  If not, then split a block of the next larger power of

  24579.   ** two in order to create a new free block of size iLogsize.

  24580.   */

  24581.   for(iBin=iLogsize; iBin<=LOGMAX && mem5.aiFreelist[iBin]<0; iBin++){}

  24582.   if( iBin>LOGMAX ){

  24583.     testcase( sqlite3GlobalConfig.xLog!=0 );

  24584.     sqlite3_log(SQLITE_NOMEM, "failed to allocate %u bytes", nByte);

  24585.     return 0;

  24586.   }

  24587.   i = mem5.aiFreelist[iBin];

  24588.   memsys5Unlink(i, iBin);

  24589.   while( iBin>iLogsize ){

  24590.     int newSize;

  24591. 

  24592.     iBin--;

  24593.     newSize = 1 << iBin;

  24594.     mem5.aCtrl[i+newSize] = CTRL_FREE | iBin;

  24595.     memsys5Link(i+newSize, iBin);

  24596.   }

  24597.   mem5.aCtrl[i] = iLogsize;

  24598. 

  24599. #if defined(SQLITE_DEBUG) || defined(SQLITE_TEST)

  24600.   /* Update allocator performance statistics. */

  24601.   mem5.nAlloc++;

  24602.   mem5.totalAlloc += iFullSz;

  24603.   mem5.totalExcess += iFullSz - nByte;

  24604.   mem5.currentCount++;

  24605.   mem5.currentOut += iFullSz;

  24606.   if( mem5.maxCount<mem5.currentCount ) mem5.maxCount = mem5.currentCount;

  24607.   if( mem5.maxOut<mem5.currentOut ) mem5.maxOut = mem5.currentOut;

  24608. #endif

  24609. 

  24610. #ifdef SQLITE_DEBUG

  24611.   /* Make sure the allocated memory does not assume that it is set to zero

  24612.   ** or retains a value from a previous allocation */

  24613.   memset(&mem5.zPool[i*mem5.szAtom], 0xAA, iFullSz);

  24614. #endif

  24615. 

  24616.   /* Return a pointer to the allocated memory. */

  24617.   return (void*)&mem5.zPool[i*mem5.szAtom];

  24618. }

  24619. 

  24620. /*

  24621. ** Free an outstanding memory allocation.

  24622. */

  24623. static void memsys5FreeUnsafe(void *pOld){

  24624.   u32 size, iLogsize;

  24625.   int iBlock;

  24626. 

  24627.   /* Set iBlock to the index of the block pointed to by pOld in 

  24628.   ** the array of mem5.szAtom byte blocks pointed to by mem5.zPool.

  24629.   */

  24630.   iBlock = (int)(((u8 *)pOld-mem5.zPool)/mem5.szAtom);

  24631. 

  24632.   /* Check that the pointer pOld points to a valid, non-free block. */

  24633.   assert( iBlock>=0 && iBlock<mem5.nBlock );

  24634.   assert( ((u8 *)pOld-mem5.zPool)%mem5.szAtom==0 );

  24635.   assert( (mem5.aCtrl[iBlock] & CTRL_FREE)==0 );

  24636. 

  24637.   iLogsize = mem5.aCtrl[iBlock] & CTRL_LOGSIZE;

  24638.   size = 1<<iLogsize;

  24639.   assert( iBlock+size-1<(u32)mem5.nBlock );

  24640. 

  24641.   mem5.aCtrl[iBlock] |= CTRL_FREE;

  24642.   mem5.aCtrl[iBlock+size-1] |= CTRL_FREE;

  24643. 

  24644. #if defined(SQLITE_DEBUG) || defined(SQLITE_TEST)

  24645.   assert( mem5.currentCount>0 );

  24646.   assert( mem5.currentOut>=(size*mem5.szAtom) );

  24647.   mem5.currentCount--;

  24648.   mem5.currentOut -= size*mem5.szAtom;

  24649.   assert( mem5.currentOut>0 || mem5.currentCount==0 );

  24650.   assert( mem5.currentCount>0 || mem5.currentOut==0 );

  24651. #endif

  24652. 

  24653.   mem5.aCtrl[iBlock] = CTRL_FREE | iLogsize;

  24654.   while( ALWAYS(iLogsize<LOGMAX) ){

  24655.     int iBuddy;

  24656.     if( (iBlock>>iLogsize) & 1 ){

  24657.       iBuddy = iBlock - size;

  24658.       assert( iBuddy>=0 );

  24659.     }else{

  24660.       iBuddy = iBlock + size;

  24661.       if( iBuddy>=mem5.nBlock ) break;

  24662.     }

  24663.     if( mem5.aCtrl[iBuddy]!=(CTRL_FREE | iLogsize) ) break;

  24664.     memsys5Unlink(iBuddy, iLogsize);

  24665.     iLogsize++;

  24666.     if( iBuddy<iBlock ){

  24667.       mem5.aCtrl[iBuddy] = CTRL_FREE | iLogsize;

  24668.       mem5.aCtrl[iBlock] = 0;

  24669.       iBlock = iBuddy;

  24670.     }else{

  24671.       mem5.aCtrl[iBlock] = CTRL_FREE | iLogsize;

  24672.       mem5.aCtrl[iBuddy] = 0;

  24673.     }

  24674.     size *= 2;

  24675.   }

  24676. 

  24677. #ifdef SQLITE_DEBUG

  24678.   /* Overwrite freed memory with the 0x55 bit pattern to verify that it is

  24679.   ** not used after being freed */

  24680.   memset(&mem5.zPool[iBlock*mem5.szAtom], 0x55, size);

  24681. #endif

  24682. 

  24683.   memsys5Link(iBlock, iLogsize);

  24684. }

  24685. 

  24686. /*

  24687. ** Allocate nBytes of memory.

  24688. */

  24689. static void *memsys5Malloc(int nBytes){

  24690.   sqlite3_int64 *p = 0;

  24691.   if( nBytes>0 ){

  24692.     memsys5Enter();

  24693.     p = memsys5MallocUnsafe(nBytes);

  24694.     memsys5Leave();

  24695.   }

  24696.   return (void*)p; 

  24697. }

  24698. 

  24699. /*

  24700. ** Free memory.

  24701. **

  24702. ** The outer layer memory allocator prevents this routine from

  24703. ** being called with pPrior==0.

  24704. */

  24705. static void memsys5Free(void *pPrior){

  24706.   assert( pPrior!=0 );

  24707.   memsys5Enter();

  24708.   memsys5FreeUnsafe(pPrior);

  24709.   memsys5Leave();  

  24710. }

  24711. 

  24712. /*

  24713. ** Change the size of an existing memory allocation.

  24714. **

  24715. ** The outer layer memory allocator prevents this routine from

  24716. ** being called with pPrior==0.  

  24717. **

  24718. ** nBytes is always a value obtained from a prior call to

  24719. ** memsys5Round().  Hence nBytes is always a non-negative power

  24720. ** of two.  If nBytes==0 that means that an oversize allocation

  24721. ** (an allocation larger than 0x40000000) was requested and this

  24722. ** routine should return 0 without freeing pPrior.

  24723. */

  24724. static void *memsys5Realloc(void *pPrior, int nBytes){

  24725.   int nOld;

  24726.   void *p;

  24727.   assert( pPrior!=0 );

  24728.   assert( (nBytes&(nBytes-1))==0 );  /* EV: R-46199-30249 */

  24729.   assert( nBytes>=0 );

  24730.   if( nBytes==0 ){

  24731.     return 0;

  24732.   }

  24733.   nOld = memsys5Size(pPrior);

  24734.   if( nBytes<=nOld ){

  24735.     return pPrior;

  24736.   }

  24737.   p = memsys5Malloc(nBytes);

  24738.   if( p ){

  24739.     memcpy(p, pPrior, nOld);

  24740.     memsys5Free(pPrior);

  24741.   }

  24742.   return p;

  24743. }

  24744. 

  24745. /*

  24746. ** Round up a request size to the next valid allocation size.  If

  24747. ** the allocation is too large to be handled by this allocation system,

  24748. ** return 0.

  24749. **

  24750. ** All allocations must be a power of two and must be expressed by a

  24751. ** 32-bit signed integer.  Hence the largest allocation is 0x40000000

  24752. ** or 1073741824 bytes.

  24753. */

  24754. static int memsys5Roundup(int n){

  24755.   int iFullSz;

  24756.   if( n > 0x40000000 ) return 0;

  24757.   for(iFullSz=mem5.szAtom; iFullSz<n; iFullSz *= 2);

  24758.   return iFullSz;

  24759. }

  24760. 

  24761. /*

  24762. ** Return the ceiling of the logarithm base 2 of iValue.

  24763. **

  24764. ** Examples:   memsys5Log(1) -> 0

  24765. **             memsys5Log(2) -> 1

  24766. **             memsys5Log(4) -> 2

  24767. **             memsys5Log(5) -> 3

  24768. **             memsys5Log(8) -> 3

  24769. **             memsys5Log(9) -> 4

  24770. */

  24771. static int memsys5Log(int iValue){

  24772.   int iLog;

  24773.   for(iLog=0; (iLog<(int)((sizeof(int)*8)-1)) && (1<<iLog)<iValue; iLog++);

  24774.   return iLog;

  24775. }

  24776. 

  24777. /*

  24778. ** Initialize the memory allocator.

  24779. **

  24780. ** This routine is not threadsafe.  The caller must be holding a mutex

  24781. ** to prevent multiple threads from entering at the same time.

  24782. */

  24783. static int memsys5Init(void *NotUsed){

  24784.   int ii;            /* Loop counter */

  24785.   int nByte;         /* Number of bytes of memory available to this allocator */

  24786.   u8 *zByte;         /* Memory usable by this allocator */

  24787.   int nMinLog;       /* Log base 2 of minimum allocation size in bytes */

  24788.   int iOffset;       /* An offset into mem5.aCtrl[] */

  24789. 

  24790.   UNUSED_PARAMETER(NotUsed);

  24791. 

  24792.   /* For the purposes of this routine, disable the mutex */

  24793.   mem5.mutex = 0;

  24794. 

  24795.   /* The size of a Mem5Link object must be a power of two.  Verify that

  24796.   ** this is case.

  24797.   */

  24798.   assert( (sizeof(Mem5Link)&(sizeof(Mem5Link)-1))==0 );

  24799. 

  24800.   nByte = sqlite3GlobalConfig.nHeap;

  24801.   zByte = (u8*)sqlite3GlobalConfig.pHeap;

  24802.   assert( zByte!=0 );  /* sqlite3_config() does not allow otherwise */

  24803. 

  24804.   /* boundaries on sqlite3GlobalConfig.mnReq are enforced in sqlite3_config() */

  24805.   nMinLog = memsys5Log(sqlite3GlobalConfig.mnReq);

  24806.   mem5.szAtom = (1<<nMinLog);

  24807.   while( (int)sizeof(Mem5Link)>mem5.szAtom ){

  24808.     mem5.szAtom = mem5.szAtom << 1;

  24809.   }

  24810. 

  24811.   mem5.nBlock = (nByte / (mem5.szAtom+sizeof(u8)));

  24812.   mem5.zPool = zByte;

  24813.   mem5.aCtrl = (u8 *)&mem5.zPool[mem5.nBlock*mem5.szAtom];

  24814. 

  24815.   for(ii=0; ii<=LOGMAX; ii++){

  24816.     mem5.aiFreelist[ii] = -1;

  24817.   }

  24818. 

  24819.   iOffset = 0;

  24820.   for(ii=LOGMAX; ii>=0; ii--){

  24821.     int nAlloc = (1<<ii);

  24822.     if( (iOffset+nAlloc)<=mem5.nBlock ){

  24823.       mem5.aCtrl[iOffset] = ii | CTRL_FREE;

  24824.       memsys5Link(iOffset, ii);

  24825.       iOffset += nAlloc;

  24826.     }

  24827.     assert((iOffset+nAlloc)>mem5.nBlock);

  24828.   }

  24829. 

  24830.   /* If a mutex is required for normal operation, allocate one */

  24831.   if( sqlite3GlobalConfig.bMemstat==0 ){

  24832.     mem5.mutex = sqlite3MutexAlloc(SQLITE_MUTEX_STATIC_MEM);

  24833.   }

  24834. 

  24835.   return SQLITE_OK;

  24836. }

  24837. 

  24838. /*

  24839. ** Deinitialize this module.

  24840. */

  24841. static void memsys5Shutdown(void *NotUsed){

  24842.   UNUSED_PARAMETER(NotUsed);

  24843.   mem5.mutex = 0;

  24844.   return;

  24845. }

  24846. 

  24847. #ifdef SQLITE_TEST

  24848. /*

  24849. ** Open the file indicated and write a log of all unfreed memory 

  24850. ** allocations into that log.

  24851. */

  24852. SQLITE_PRIVATE void sqlite3Memsys5Dump(const char *zFilename){

  24853.   FILE *out;

  24854.   int i, j, n;

  24855.   int nMinLog;

  24856. 

  24857.   if( zFilename==0 || zFilename[0]==0 ){

  24858.     out = stdout;

  24859.   }else{

  24860.     out = fopen(zFilename, "w");

  24861.     if( out==0 ){

  24862.       fprintf(stderr, "** Unable to output memory debug output log: %s **\n",

  24863.                       zFilename);

  24864.       return;

  24865.     }

  24866.   }

  24867.   memsys5Enter();

  24868.   nMinLog = memsys5Log(mem5.szAtom);

  24869.   for(i=0; i<=LOGMAX && i+nMinLog<32; i++){

  24870.     for(n=0, j=mem5.aiFreelist[i]; j>=0; j = MEM5LINK(j)->next, n++){}

  24871.     fprintf(out, "freelist items of size %d: %d\n", mem5.szAtom << i, n);

  24872.   }

  24873.   fprintf(out, "mem5.nAlloc       = %llu\n", mem5.nAlloc);

  24874.   fprintf(out, "mem5.totalAlloc   = %llu\n", mem5.totalAlloc);

  24875.   fprintf(out, "mem5.totalExcess  = %llu\n", mem5.totalExcess);

  24876.   fprintf(out, "mem5.currentOut   = %u\n", mem5.currentOut);

  24877.   fprintf(out, "mem5.currentCount = %u\n", mem5.currentCount);

  24878.   fprintf(out, "mem5.maxOut       = %u\n", mem5.maxOut);

  24879.   fprintf(out, "mem5.maxCount     = %u\n", mem5.maxCount);

  24880.   fprintf(out, "mem5.maxRequest   = %u\n", mem5.maxRequest);

  24881.   memsys5Leave();

  24882.   if( out==stdout ){

  24883.     fflush(stdout);

  24884.   }else{

  24885.     fclose(out);

  24886.   }

  24887. }

  24888. #endif

  24889. 

  24890. /*

  24891. ** This routine is the only routine in this file with external 

  24892. ** linkage. It returns a pointer to a static sqlite3_mem_methods

  24893. ** struct populated with the memsys5 methods.

  24894. */

  24895. SQLITE_PRIVATE const sqlite3_mem_methods *sqlite3MemGetMemsys5(void){

  24896.   static const sqlite3_mem_methods memsys5Methods = {

  24897.      memsys5Malloc,

  24898.      memsys5Free,

  24899.      memsys5Realloc,

  24900.      memsys5Size,

  24901.      memsys5Roundup,

  24902.      memsys5Init,

  24903.      memsys5Shutdown,

  24904.      0

  24905.   };

  24906.   return &memsys5Methods;

  24907. }

  24908. 

  24909. #endif /* SQLITE_ENABLE_MEMSYS5 */

  24910. 

  24911. /************** End of mem5.c ************************************************/

  24912. /************** Begin file mutex.c *******************************************/

  24913. /*

  24914. ** 2007 August 14

  24915. **

  24916. ** The author disclaims copyright to this source code.  In place of

  24917. ** a legal notice, here is a blessing:

  24918. **

  24919. **    May you do good and not evil.

  24920. **    May you find forgiveness for yourself and forgive others.

  24921. **    May you share freely, never taking more than you give.

  24922. **

  24923. *************************************************************************

  24924. ** This file contains the C functions that implement mutexes.

  24925. **

  24926. ** This file contains code that is common across all mutex implementations.

  24927. */

  24928. /* #include "sqliteInt.h" */

  24929. 

  24930. #if defined(SQLITE_DEBUG) && !defined(SQLITE_MUTEX_OMIT)

  24931. /*

  24932. ** For debugging purposes, record when the mutex subsystem is initialized

  24933. ** and uninitialized so that we can assert() if there is an attempt to

  24934. ** allocate a mutex while the system is uninitialized.

  24935. */

  24936. static SQLITE_WSD int mutexIsInit = 0;

  24937. #endif /* SQLITE_DEBUG && !defined(SQLITE_MUTEX_OMIT) */

  24938. 

  24939. 

  24940. #ifndef SQLITE_MUTEX_OMIT

  24941. 

  24942. #ifdef SQLITE_ENABLE_MULTITHREADED_CHECKS

  24943. /*

  24944. ** This block (enclosed by SQLITE_ENABLE_MULTITHREADED_CHECKS) contains

  24945. ** the implementation of a wrapper around the system default mutex

  24946. ** implementation (sqlite3DefaultMutex()). 

  24947. **

  24948. ** Most calls are passed directly through to the underlying default

  24949. ** mutex implementation. Except, if a mutex is configured by calling

  24950. ** sqlite3MutexWarnOnContention() on it, then if contention is ever

  24951. ** encountered within xMutexEnter() a warning is emitted via sqlite3_log().

  24952. **

  24953. ** This type of mutex is used as the database handle mutex when testing

  24954. ** apps that usually use SQLITE_CONFIG_MULTITHREAD mode.

  24955. */

  24956. 

  24957. /* 

  24958. ** Type for all mutexes used when SQLITE_ENABLE_MULTITHREADED_CHECKS

  24959. ** is defined. Variable CheckMutex.mutex is a pointer to the real mutex

  24960. ** allocated by the system mutex implementation. Variable iType is usually set

  24961. ** to the type of mutex requested - SQLITE_MUTEX_RECURSIVE, SQLITE_MUTEX_FAST

  24962. ** or one of the static mutex identifiers. Or, if this is a recursive mutex

  24963. ** that has been configured using sqlite3MutexWarnOnContention(), it is

  24964. ** set to SQLITE_MUTEX_WARNONCONTENTION.

  24965. */

  24966. typedef struct CheckMutex CheckMutex;

  24967. struct CheckMutex {

  24968.   int iType;

  24969.   sqlite3_mutex *mutex;

  24970. };

  24971. 

  24972. #define SQLITE_MUTEX_WARNONCONTENTION  (-1)

  24973. 

  24974. /* 

  24975. ** Pointer to real mutex methods object used by the CheckMutex

  24976. ** implementation. Set by checkMutexInit(). 

  24977. */

  24978. static SQLITE_WSD const sqlite3_mutex_methods *pGlobalMutexMethods;

  24979. 

  24980. #ifdef SQLITE_DEBUG

  24981. static int checkMutexHeld(sqlite3_mutex *p){

  24982.   return pGlobalMutexMethods->xMutexHeld(((CheckMutex*)p)->mutex);

  24983. }

  24984. static int checkMutexNotheld(sqlite3_mutex *p){

  24985.   return pGlobalMutexMethods->xMutexNotheld(((CheckMutex*)p)->mutex);

  24986. }

  24987. #endif

  24988. 

  24989. /*

  24990. ** Initialize and deinitialize the mutex subsystem.

  24991. */

  24992. static int checkMutexInit(void){ 

  24993.   pGlobalMutexMethods = sqlite3DefaultMutex();

  24994.   return SQLITE_OK; 

  24995. }

  24996. static int checkMutexEnd(void){ 

  24997.   pGlobalMutexMethods = 0;

  24998.   return SQLITE_OK; 

  24999. }

  25000. 

  25001. /*

  25002. ** Allocate a mutex.

  25003. */

  25004. static sqlite3_mutex *checkMutexAlloc(int iType){

  25005.   static CheckMutex staticMutexes[] = {

  25006.     {2, 0}, {3, 0}, {4, 0}, {5, 0},

  25007.     {6, 0}, {7, 0}, {8, 0}, {9, 0},

  25008.     {10, 0}, {11, 0}, {12, 0}, {13, 0}

  25009.   };

  25010.   CheckMutex *p = 0;

  25011. 

  25012.   assert( SQLITE_MUTEX_RECURSIVE==1 && SQLITE_MUTEX_FAST==0 );

  25013.   if( iType<2 ){

  25014.     p = sqlite3MallocZero(sizeof(CheckMutex));

  25015.     if( p==0 ) return 0;

  25016.     p->iType = iType;

  25017.   }else{

  25018. #ifdef SQLITE_ENABLE_API_ARMOR

  25019.     if( iType-2>=ArraySize(staticMutexes) ){

  25020.       (void)SQLITE_MISUSE_BKPT;

  25021.       return 0;

  25022.     }

  25023. #endif

  25024.     p = &staticMutexes[iType-2];

  25025.   }

  25026. 

  25027.   if( p->mutex==0 ){

  25028.     p->mutex = pGlobalMutexMethods->xMutexAlloc(iType);

  25029.     if( p->mutex==0 ){

  25030.       if( iType<2 ){

  25031.         sqlite3_free(p);

  25032.       }

  25033.       p = 0;

  25034.     }

  25035.   }

  25036. 

  25037.   return (sqlite3_mutex*)p;

  25038. }

  25039. 

  25040. /*

  25041. ** Free a mutex.

  25042. */

  25043. static void checkMutexFree(sqlite3_mutex *p){

  25044.   assert( SQLITE_MUTEX_RECURSIVE<2 );

  25045.   assert( SQLITE_MUTEX_FAST<2 );

  25046.   assert( SQLITE_MUTEX_WARNONCONTENTION<2 );

  25047. 

  25048. #if SQLITE_ENABLE_API_ARMOR

  25049.   if( ((CheckMutex*)p)->iType<2 )

  25050. #endif

  25051.   {

  25052.     CheckMutex *pCheck = (CheckMutex*)p;

  25053.     pGlobalMutexMethods->xMutexFree(pCheck->mutex);

  25054.     sqlite3_free(pCheck);

  25055.   }

  25056. #ifdef SQLITE_ENABLE_API_ARMOR

  25057.   else{

  25058.     (void)SQLITE_MISUSE_BKPT;

  25059.   }

  25060. #endif

  25061. }

  25062. 

  25063. /*

  25064. ** Enter the mutex.

  25065. */

  25066. static void checkMutexEnter(sqlite3_mutex *p){

  25067.   CheckMutex *pCheck = (CheckMutex*)p;

  25068.   if( pCheck->iType==SQLITE_MUTEX_WARNONCONTENTION ){

  25069.     if( SQLITE_OK==pGlobalMutexMethods->xMutexTry(pCheck->mutex) ){

  25070.       return;

  25071.     }

  25072.     sqlite3_log(SQLITE_MISUSE, 

  25073.         "illegal multi-threaded access to database connection"

  25074.     );

  25075.   }

  25076.   pGlobalMutexMethods->xMutexEnter(pCheck->mutex);

  25077. }

  25078. 

  25079. /*

  25080. ** Enter the mutex (do not block).

  25081. */

  25082. static int checkMutexTry(sqlite3_mutex *p){

  25083.   CheckMutex *pCheck = (CheckMutex*)p;

  25084.   return pGlobalMutexMethods->xMutexTry(pCheck->mutex);

  25085. }

  25086. 

  25087. /*

  25088. ** Leave the mutex.

  25089. */

  25090. static void checkMutexLeave(sqlite3_mutex *p){

  25091.   CheckMutex *pCheck = (CheckMutex*)p;

  25092.   pGlobalMutexMethods->xMutexLeave(pCheck->mutex);

  25093. }

  25094. 

  25095. sqlite3_mutex_methods const *multiThreadedCheckMutex(void){

  25096.   static const sqlite3_mutex_methods sMutex = {

  25097.     checkMutexInit,

  25098.     checkMutexEnd,

  25099.     checkMutexAlloc,

  25100.     checkMutexFree,

  25101.     checkMutexEnter,

  25102.     checkMutexTry,

  25103.     checkMutexLeave,

  25104. #ifdef SQLITE_DEBUG

  25105.     checkMutexHeld,

  25106.     checkMutexNotheld

  25107. #else

  25108.     0,

  25109.     0

  25110. #endif

  25111.   };

  25112.   return &sMutex;

  25113. }

  25114. 

  25115. /*

  25116. ** Mark the SQLITE_MUTEX_RECURSIVE mutex passed as the only argument as

  25117. ** one on which there should be no contention.

  25118. */

  25119. SQLITE_PRIVATE void sqlite3MutexWarnOnContention(sqlite3_mutex *p){

  25120.   if( sqlite3GlobalConfig.mutex.xMutexAlloc==checkMutexAlloc ){

  25121.     CheckMutex *pCheck = (CheckMutex*)p;

  25122.     assert( pCheck->iType==SQLITE_MUTEX_RECURSIVE );

  25123.     pCheck->iType = SQLITE_MUTEX_WARNONCONTENTION;

  25124.   }

  25125. }

  25126. #endif   /* ifdef SQLITE_ENABLE_MULTITHREADED_CHECKS */

  25127. 

  25128. /*

  25129. ** Initialize the mutex system.

  25130. */

  25131. SQLITE_PRIVATE int sqlite3MutexInit(void){ 

  25132.   int rc = SQLITE_OK;

  25133.   if( !sqlite3GlobalConfig.mutex.xMutexAlloc ){

  25134.     /* If the xMutexAlloc method has not been set, then the user did not

  25135.     ** install a mutex implementation via sqlite3_config() prior to 

  25136.     ** sqlite3_initialize() being called. This block copies pointers to

  25137.     ** the default implementation into the sqlite3GlobalConfig structure.

  25138.     */

  25139.     sqlite3_mutex_methods const *pFrom;

  25140.     sqlite3_mutex_methods *pTo = &sqlite3GlobalConfig.mutex;

  25141. 

  25142.     if( sqlite3GlobalConfig.bCoreMutex ){

  25143. #ifdef SQLITE_ENABLE_MULTITHREADED_CHECKS

  25144.       pFrom = multiThreadedCheckMutex();

  25145. #else

  25146.       pFrom = sqlite3DefaultMutex();

  25147. #endif

  25148.     }else{

  25149.       pFrom = sqlite3NoopMutex();

  25150.     }

  25151.     pTo->xMutexInit = pFrom->xMutexInit;

  25152.     pTo->xMutexEnd = pFrom->xMutexEnd;

  25153.     pTo->xMutexFree = pFrom->xMutexFree;

  25154.     pTo->xMutexEnter = pFrom->xMutexEnter;

  25155.     pTo->xMutexTry = pFrom->xMutexTry;

  25156.     pTo->xMutexLeave = pFrom->xMutexLeave;

  25157.     pTo->xMutexHeld = pFrom->xMutexHeld;

  25158.     pTo->xMutexNotheld = pFrom->xMutexNotheld;

  25159.     sqlite3MemoryBarrier();

  25160.     pTo->xMutexAlloc = pFrom->xMutexAlloc;

  25161.   }

  25162.   assert( sqlite3GlobalConfig.mutex.xMutexInit );

  25163.   rc = sqlite3GlobalConfig.mutex.xMutexInit();

  25164. 

  25165. #ifdef SQLITE_DEBUG

  25166.   GLOBAL(int, mutexIsInit) = 1;

  25167. #endif

  25168. 

  25169.   return rc;

  25170. }

  25171. 

  25172. /*

  25173. ** Shutdown the mutex system. This call frees resources allocated by

  25174. ** sqlite3MutexInit().

  25175. */

  25176. SQLITE_PRIVATE int sqlite3MutexEnd(void){

  25177.   int rc = SQLITE_OK;

  25178.   if( sqlite3GlobalConfig.mutex.xMutexEnd ){

  25179.     rc = sqlite3GlobalConfig.mutex.xMutexEnd();

  25180.   }

  25181. 

  25182. #ifdef SQLITE_DEBUG

  25183.   GLOBAL(int, mutexIsInit) = 0;

  25184. #endif

  25185. 

  25186.   return rc;

  25187. }

  25188. 

  25189. /*

  25190. ** Retrieve a pointer to a static mutex or allocate a new dynamic one.

  25191. */

  25192. SQLITE_API sqlite3_mutex *sqlite3_mutex_alloc(int id){

  25193. #ifndef SQLITE_OMIT_AUTOINIT

  25194.   if( id<=SQLITE_MUTEX_RECURSIVE && sqlite3_initialize() ) return 0;

  25195.   if( id>SQLITE_MUTEX_RECURSIVE && sqlite3MutexInit() ) return 0;

  25196. #endif

  25197.   assert( sqlite3GlobalConfig.mutex.xMutexAlloc );

  25198.   return sqlite3GlobalConfig.mutex.xMutexAlloc(id);

  25199. }

  25200. 

  25201. SQLITE_PRIVATE sqlite3_mutex *sqlite3MutexAlloc(int id){

  25202.   if( !sqlite3GlobalConfig.bCoreMutex ){

  25203.     return 0;

  25204.   }

  25205.   assert( GLOBAL(int, mutexIsInit) );

  25206.   assert( sqlite3GlobalConfig.mutex.xMutexAlloc );

  25207.   return sqlite3GlobalConfig.mutex.xMutexAlloc(id);

  25208. }

  25209. 

  25210. /*

  25211. ** Free a dynamic mutex.

  25212. */

  25213. SQLITE_API void sqlite3_mutex_free(sqlite3_mutex *p){

  25214.   if( p ){

  25215.     assert( sqlite3GlobalConfig.mutex.xMutexFree );

  25216.     sqlite3GlobalConfig.mutex.xMutexFree(p);

  25217.   }

  25218. }

  25219. 

  25220. /*

  25221. ** Obtain the mutex p. If some other thread already has the mutex, block

  25222. ** until it can be obtained.

  25223. */

  25224. SQLITE_API void sqlite3_mutex_enter(sqlite3_mutex *p){

  25225.   if( p ){

  25226.     assert( sqlite3GlobalConfig.mutex.xMutexEnter );

  25227.     sqlite3GlobalConfig.mutex.xMutexEnter(p);

  25228.   }

  25229. }

  25230. 

  25231. /*

  25232. ** Obtain the mutex p. If successful, return SQLITE_OK. Otherwise, if another

  25233. ** thread holds the mutex and it cannot be obtained, return SQLITE_BUSY.

  25234. */

  25235. SQLITE_API int sqlite3_mutex_try(sqlite3_mutex *p){

  25236.   int rc = SQLITE_OK;

  25237.   if( p ){

  25238.     assert( sqlite3GlobalConfig.mutex.xMutexTry );

  25239.     return sqlite3GlobalConfig.mutex.xMutexTry(p);

  25240.   }

  25241.   return rc;

  25242. }

  25243. 

  25244. /*

  25245. ** The sqlite3_mutex_leave() routine exits a mutex that was previously

  25246. ** entered by the same thread.  The behavior is undefined if the mutex 

  25247. ** is not currently entered. If a NULL pointer is passed as an argument

  25248. ** this function is a no-op.

  25249. */

  25250. SQLITE_API void sqlite3_mutex_leave(sqlite3_mutex *p){

  25251.   if( p ){

  25252.     assert( sqlite3GlobalConfig.mutex.xMutexLeave );

  25253.     sqlite3GlobalConfig.mutex.xMutexLeave(p);

  25254.   }

  25255. }

  25256. 

  25257. #ifndef NDEBUG

  25258. /*

  25259. ** The sqlite3_mutex_held() and sqlite3_mutex_notheld() routine are

  25260. ** intended for use inside assert() statements.

  25261. */

  25262. SQLITE_API int sqlite3_mutex_held(sqlite3_mutex *p){

  25263.   assert( p==0 || sqlite3GlobalConfig.mutex.xMutexHeld );

  25264.   return p==0 || sqlite3GlobalConfig.mutex.xMutexHeld(p);

  25265. }

  25266. SQLITE_API int sqlite3_mutex_notheld(sqlite3_mutex *p){

  25267.   assert( p==0 || sqlite3GlobalConfig.mutex.xMutexNotheld );

  25268.   return p==0 || sqlite3GlobalConfig.mutex.xMutexNotheld(p);

  25269. }

  25270. #endif

  25271. 

  25272. #endif /* !defined(SQLITE_MUTEX_OMIT) */

  25273. 

  25274. /************** End of mutex.c ***********************************************/

  25275. /************** Begin file mutex_noop.c **************************************/

  25276. /*

  25277. ** 2008 October 07

  25278. **

  25279. ** The author disclaims copyright to this source code.  In place of

  25280. ** a legal notice, here is a blessing:

  25281. **

  25282. **    May you do good and not evil.

  25283. **    May you find forgiveness for yourself and forgive others.

  25284. **    May you share freely, never taking more than you give.

  25285. **

  25286. *************************************************************************

  25287. ** This file contains the C functions that implement mutexes.

  25288. **

  25289. ** This implementation in this file does not provide any mutual

  25290. ** exclusion and is thus suitable for use only in applications

  25291. ** that use SQLite in a single thread.  The routines defined

  25292. ** here are place-holders.  Applications can substitute working

  25293. ** mutex routines at start-time using the

  25294. **

  25295. **     sqlite3_config(SQLITE_CONFIG_MUTEX,...)

  25296. **

  25297. ** interface.

  25298. **

  25299. ** If compiled with SQLITE_DEBUG, then additional logic is inserted

  25300. ** that does error checking on mutexes to make sure they are being

  25301. ** called correctly.

  25302. */

  25303. /* #include "sqliteInt.h" */

  25304. 

  25305. #ifndef SQLITE_MUTEX_OMIT

  25306. 

  25307. #ifndef SQLITE_DEBUG

  25308. /*

  25309. ** Stub routines for all mutex methods.

  25310. **

  25311. ** This routines provide no mutual exclusion or error checking.

  25312. */

  25313. static int noopMutexInit(void){ return SQLITE_OK; }

  25314. static int noopMutexEnd(void){ return SQLITE_OK; }

  25315. static sqlite3_mutex *noopMutexAlloc(int id){ 

  25316.   UNUSED_PARAMETER(id);

  25317.   return (sqlite3_mutex*)8; 

  25318. }

  25319. static void noopMutexFree(sqlite3_mutex *p){ UNUSED_PARAMETER(p); return; }

  25320. static void noopMutexEnter(sqlite3_mutex *p){ UNUSED_PARAMETER(p); return; }

  25321. static int noopMutexTry(sqlite3_mutex *p){

  25322.   UNUSED_PARAMETER(p);

  25323.   return SQLITE_OK;

  25324. }

  25325. static void noopMutexLeave(sqlite3_mutex *p){ UNUSED_PARAMETER(p); return; }

  25326. 

  25327. SQLITE_PRIVATE sqlite3_mutex_methods const *sqlite3NoopMutex(void){

  25328.   static const sqlite3_mutex_methods sMutex = {

  25329.     noopMutexInit,

  25330.     noopMutexEnd,

  25331.     noopMutexAlloc,

  25332.     noopMutexFree,

  25333.     noopMutexEnter,

  25334.     noopMutexTry,

  25335.     noopMutexLeave,

  25336. 

  25337.     0,

  25338.     0,

  25339.   };

  25340. 

  25341.   return &sMutex;

  25342. }

  25343. #endif /* !SQLITE_DEBUG */

  25344. 

  25345. #ifdef SQLITE_DEBUG

  25346. /*

  25347. ** In this implementation, error checking is provided for testing

  25348. ** and debugging purposes.  The mutexes still do not provide any

  25349. ** mutual exclusion.

  25350. */

  25351. 

  25352. /*

  25353. ** The mutex object

  25354. */

  25355. typedef struct sqlite3_debug_mutex {

  25356.   int id;     /* The mutex type */

  25357.   int cnt;    /* Number of entries without a matching leave */

  25358. } sqlite3_debug_mutex;

  25359. 

  25360. /*

  25361. ** The sqlite3_mutex_held() and sqlite3_mutex_notheld() routine are

  25362. ** intended for use inside assert() statements.

  25363. */

  25364. static int debugMutexHeld(sqlite3_mutex *pX){

  25365.   sqlite3_debug_mutex *p = (sqlite3_debug_mutex*)pX;

  25366.   return p==0 || p->cnt>0;

  25367. }

  25368. static int debugMutexNotheld(sqlite3_mutex *pX){

  25369.   sqlite3_debug_mutex *p = (sqlite3_debug_mutex*)pX;

  25370.   return p==0 || p->cnt==0;

  25371. }

  25372. 

  25373. /*

  25374. ** Initialize and deinitialize the mutex subsystem.

  25375. */

  25376. static int debugMutexInit(void){ return SQLITE_OK; }

  25377. static int debugMutexEnd(void){ return SQLITE_OK; }

  25378. 

  25379. /*

  25380. ** The sqlite3_mutex_alloc() routine allocates a new

  25381. ** mutex and returns a pointer to it.  If it returns NULL

  25382. ** that means that a mutex could not be allocated. 

  25383. */

  25384. static sqlite3_mutex *debugMutexAlloc(int id){

  25385.   static sqlite3_debug_mutex aStatic[SQLITE_MUTEX_STATIC_VFS3 - 1];

  25386.   sqlite3_debug_mutex *pNew = 0;

  25387.   switch( id ){

  25388.     case SQLITE_MUTEX_FAST:

  25389.     case SQLITE_MUTEX_RECURSIVE: {

  25390.       pNew = sqlite3Malloc(sizeof(*pNew));

  25391.       if( pNew ){

  25392.         pNew->id = id;

  25393.         pNew->cnt = 0;

  25394.       }

  25395.       break;

  25396.     }

  25397.     default: {

  25398. #ifdef SQLITE_ENABLE_API_ARMOR

  25399.       if( id-2<0 || id-2>=ArraySize(aStatic) ){

  25400.         (void)SQLITE_MISUSE_BKPT;

  25401.         return 0;

  25402.       }

  25403. #endif

  25404.       pNew = &aStatic[id-2];

  25405.       pNew->id = id;

  25406.       break;

  25407.     }

  25408.   }

  25409.   return (sqlite3_mutex*)pNew;

  25410. }

  25411. 

  25412. /*

  25413. ** This routine deallocates a previously allocated mutex.

  25414. */

  25415. static void debugMutexFree(sqlite3_mutex *pX){

  25416.   sqlite3_debug_mutex *p = (sqlite3_debug_mutex*)pX;

  25417.   assert( p->cnt==0 );

  25418.   if( p->id==SQLITE_MUTEX_RECURSIVE || p->id==SQLITE_MUTEX_FAST ){

  25419.     sqlite3_free(p);

  25420.   }else{

  25421. #ifdef SQLITE_ENABLE_API_ARMOR

  25422.     (void)SQLITE_MISUSE_BKPT;

  25423. #endif

  25424.   }

  25425. }

  25426. 

  25427. /*

  25428. ** The sqlite3_mutex_enter() and sqlite3_mutex_try() routines attempt

  25429. ** to enter a mutex.  If another thread is already within the mutex,

  25430. ** sqlite3_mutex_enter() will block and sqlite3_mutex_try() will return

  25431. ** SQLITE_BUSY.  The sqlite3_mutex_try() interface returns SQLITE_OK

  25432. ** upon successful entry.  Mutexes created using SQLITE_MUTEX_RECURSIVE can

  25433. ** be entered multiple times by the same thread.  In such cases the,

  25434. ** mutex must be exited an equal number of times before another thread

  25435. ** can enter.  If the same thread tries to enter any other kind of mutex

  25436. ** more than once, the behavior is undefined.

  25437. */

  25438. static void debugMutexEnter(sqlite3_mutex *pX){

  25439.   sqlite3_debug_mutex *p = (sqlite3_debug_mutex*)pX;

  25440.   assert( p->id==SQLITE_MUTEX_RECURSIVE || debugMutexNotheld(pX) );

  25441.   p->cnt++;

  25442. }

  25443. static int debugMutexTry(sqlite3_mutex *pX){

  25444.   sqlite3_debug_mutex *p = (sqlite3_debug_mutex*)pX;

  25445.   assert( p->id==SQLITE_MUTEX_RECURSIVE || debugMutexNotheld(pX) );

  25446.   p->cnt++;

  25447.   return SQLITE_OK;

  25448. }

  25449. 

  25450. /*

  25451. ** The sqlite3_mutex_leave() routine exits a mutex that was

  25452. ** previously entered by the same thread.  The behavior

  25453. ** is undefined if the mutex is not currently entered or

  25454. ** is not currently allocated.  SQLite will never do either.

  25455. */

  25456. static void debugMutexLeave(sqlite3_mutex *pX){

  25457.   sqlite3_debug_mutex *p = (sqlite3_debug_mutex*)pX;

  25458.   assert( debugMutexHeld(pX) );

  25459.   p->cnt--;

  25460.   assert( p->id==SQLITE_MUTEX_RECURSIVE || debugMutexNotheld(pX) );

  25461. }

  25462. 

  25463. SQLITE_PRIVATE sqlite3_mutex_methods const *sqlite3NoopMutex(void){

  25464.   static const sqlite3_mutex_methods sMutex = {

  25465.     debugMutexInit,

  25466.     debugMutexEnd,

  25467.     debugMutexAlloc,

  25468.     debugMutexFree,

  25469.     debugMutexEnter,

  25470.     debugMutexTry,

  25471.     debugMutexLeave,

  25472. 

  25473.     debugMutexHeld,

  25474.     debugMutexNotheld

  25475.   };

  25476. 

  25477.   return &sMutex;

  25478. }

  25479. #endif /* SQLITE_DEBUG */

  25480. 

  25481. /*

  25482. ** If compiled with SQLITE_MUTEX_NOOP, then the no-op mutex implementation

  25483. ** is used regardless of the run-time threadsafety setting.

  25484. */

  25485. #ifdef SQLITE_MUTEX_NOOP

  25486. SQLITE_PRIVATE sqlite3_mutex_methods const *sqlite3DefaultMutex(void){

  25487.   return sqlite3NoopMutex();

  25488. }

  25489. #endif /* defined(SQLITE_MUTEX_NOOP) */

  25490. #endif /* !defined(SQLITE_MUTEX_OMIT) */

  25491. 

  25492. /************** End of mutex_noop.c ******************************************/

  25493. /************** Begin file mutex_unix.c **************************************/

  25494. /*

  25495. ** 2007 August 28

  25496. **

  25497. ** The author disclaims copyright to this source code.  In place of

  25498. ** a legal notice, here is a blessing:

  25499. **

  25500. **    May you do good and not evil.

  25501. **    May you find forgiveness for yourself and forgive others.

  25502. **    May you share freely, never taking more than you give.

  25503. **

  25504. *************************************************************************

  25505. ** This file contains the C functions that implement mutexes for pthreads

  25506. */

  25507. /* #include "sqliteInt.h" */

  25508. 

  25509. /*

  25510. ** The code in this file is only used if we are compiling threadsafe

  25511. ** under unix with pthreads.

  25512. **

  25513. ** Note that this implementation requires a version of pthreads that

  25514. ** supports recursive mutexes.

  25515. */

  25516. #ifdef SQLITE_MUTEX_PTHREADS

  25517. 

  25518. #include <pthread.h>

  25519. 

  25520. /*

  25521. ** The sqlite3_mutex.id, sqlite3_mutex.nRef, and sqlite3_mutex.owner fields

  25522. ** are necessary under two condidtions:  (1) Debug builds and (2) using

  25523. ** home-grown mutexes.  Encapsulate these conditions into a single #define.

  25524. */

  25525. #if defined(SQLITE_DEBUG) || defined(SQLITE_HOMEGROWN_RECURSIVE_MUTEX)

  25526. # define SQLITE_MUTEX_NREF 1

  25527. #else

  25528. # define SQLITE_MUTEX_NREF 0

  25529. #endif

  25530. 

  25531. /*

  25532. ** Each recursive mutex is an instance of the following structure.

  25533. */

  25534. struct sqlite3_mutex {

  25535.   pthread_mutex_t mutex;     /* Mutex controlling the lock */

  25536. #if SQLITE_MUTEX_NREF || defined(SQLITE_ENABLE_API_ARMOR)

  25537.   int id;                    /* Mutex type */

  25538. #endif

  25539. #if SQLITE_MUTEX_NREF

  25540.   volatile int nRef;         /* Number of entrances */

  25541.   volatile pthread_t owner;  /* Thread that is within this mutex */

  25542.   int trace;                 /* True to trace changes */

  25543. #endif

  25544. };

  25545. #if SQLITE_MUTEX_NREF

  25546. # define SQLITE3_MUTEX_INITIALIZER(id) \

  25547.      {PTHREAD_MUTEX_INITIALIZER,id,0,(pthread_t)0,0}

  25548. #elif defined(SQLITE_ENABLE_API_ARMOR)

  25549. # define SQLITE3_MUTEX_INITIALIZER(id) { PTHREAD_MUTEX_INITIALIZER, id }

  25550. #else

  25551. #define SQLITE3_MUTEX_INITIALIZER(id) { PTHREAD_MUTEX_INITIALIZER }

  25552. #endif

  25553. 

  25554. /*

  25555. ** The sqlite3_mutex_held() and sqlite3_mutex_notheld() routine are

  25556. ** intended for use only inside assert() statements.  On some platforms,

  25557. ** there might be race conditions that can cause these routines to

  25558. ** deliver incorrect results.  In particular, if pthread_equal() is

  25559. ** not an atomic operation, then these routines might delivery

  25560. ** incorrect results.  On most platforms, pthread_equal() is a 

  25561. ** comparison of two integers and is therefore atomic.  But we are

  25562. ** told that HPUX is not such a platform.  If so, then these routines

  25563. ** will not always work correctly on HPUX.

  25564. **

  25565. ** On those platforms where pthread_equal() is not atomic, SQLite

  25566. ** should be compiled without -DSQLITE_DEBUG and with -DNDEBUG to

  25567. ** make sure no assert() statements are evaluated and hence these

  25568. ** routines are never called.

  25569. */

  25570. #if !defined(NDEBUG) || defined(SQLITE_DEBUG)

  25571. static int pthreadMutexHeld(sqlite3_mutex *p){

  25572.   return (p->nRef!=0 && pthread_equal(p->owner, pthread_self()));

  25573. }

  25574. static int pthreadMutexNotheld(sqlite3_mutex *p){

  25575.   return p->nRef==0 || pthread_equal(p->owner, pthread_self())==0;

  25576. }

  25577. #endif

  25578. 

  25579. /*

  25580. ** Try to provide a memory barrier operation, needed for initialization

  25581. ** and also for the implementation of xShmBarrier in the VFS in cases

  25582. ** where SQLite is compiled without mutexes.

  25583. */

  25584. SQLITE_PRIVATE void sqlite3MemoryBarrier(void){

  25585. #if defined(SQLITE_MEMORY_BARRIER)

  25586.   SQLITE_MEMORY_BARRIER;

  25587. #elif defined(__GNUC__) && GCC_VERSION>=4001000

  25588.   __sync_synchronize();

  25589. #endif

  25590. }

  25591. 

  25592. /*

  25593. ** Initialize and deinitialize the mutex subsystem.

  25594. */

  25595. static int pthreadMutexInit(void){ return SQLITE_OK; }

  25596. static int pthreadMutexEnd(void){ return SQLITE_OK; }

  25597. 

  25598. /*

  25599. ** The sqlite3_mutex_alloc() routine allocates a new

  25600. ** mutex and returns a pointer to it.  If it returns NULL

  25601. ** that means that a mutex could not be allocated.  SQLite

  25602. ** will unwind its stack and return an error.  The argument

  25603. ** to sqlite3_mutex_alloc() is one of these integer constants:

  25604. **

  25605. ** <ul>

  25606. ** <li>  SQLITE_MUTEX_FAST

  25607. ** <li>  SQLITE_MUTEX_RECURSIVE

  25608. ** <li>  SQLITE_MUTEX_STATIC_MASTER

  25609. ** <li>  SQLITE_MUTEX_STATIC_MEM

  25610. ** <li>  SQLITE_MUTEX_STATIC_OPEN

  25611. ** <li>  SQLITE_MUTEX_STATIC_PRNG

  25612. ** <li>  SQLITE_MUTEX_STATIC_LRU

  25613. ** <li>  SQLITE_MUTEX_STATIC_PMEM

  25614. ** <li>  SQLITE_MUTEX_STATIC_APP1

  25615. ** <li>  SQLITE_MUTEX_STATIC_APP2

  25616. ** <li>  SQLITE_MUTEX_STATIC_APP3

  25617. ** <li>  SQLITE_MUTEX_STATIC_VFS1

  25618. ** <li>  SQLITE_MUTEX_STATIC_VFS2

  25619. ** <li>  SQLITE_MUTEX_STATIC_VFS3

  25620. ** </ul>

  25621. **

  25622. ** The first two constants cause sqlite3_mutex_alloc() to create

  25623. ** a new mutex.  The new mutex is recursive when SQLITE_MUTEX_RECURSIVE

  25624. ** is used but not necessarily so when SQLITE_MUTEX_FAST is used.

  25625. ** The mutex implementation does not need to make a distinction

  25626. ** between SQLITE_MUTEX_RECURSIVE and SQLITE_MUTEX_FAST if it does

  25627. ** not want to.  But SQLite will only request a recursive mutex in

  25628. ** cases where it really needs one.  If a faster non-recursive mutex

  25629. ** implementation is available on the host platform, the mutex subsystem

  25630. ** might return such a mutex in response to SQLITE_MUTEX_FAST.

  25631. **

  25632. ** The other allowed parameters to sqlite3_mutex_alloc() each return

  25633. ** a pointer to a static preexisting mutex.  Six static mutexes are

  25634. ** used by the current version of SQLite.  Future versions of SQLite

  25635. ** may add additional static mutexes.  Static mutexes are for internal

  25636. ** use by SQLite only.  Applications that use SQLite mutexes should

  25637. ** use only the dynamic mutexes returned by SQLITE_MUTEX_FAST or

  25638. ** SQLITE_MUTEX_RECURSIVE.

  25639. **

  25640. ** Note that if one of the dynamic mutex parameters (SQLITE_MUTEX_FAST

  25641. ** or SQLITE_MUTEX_RECURSIVE) is used then sqlite3_mutex_alloc()

  25642. ** returns a different mutex on every call.  But for the static 

  25643. ** mutex types, the same mutex is returned on every call that has

  25644. ** the same type number.

  25645. */

  25646. static sqlite3_mutex *pthreadMutexAlloc(int iType){

  25647.   static sqlite3_mutex staticMutexes[] = {

  25648.     SQLITE3_MUTEX_INITIALIZER(2),

  25649.     SQLITE3_MUTEX_INITIALIZER(3),

  25650.     SQLITE3_MUTEX_INITIALIZER(4),

  25651.     SQLITE3_MUTEX_INITIALIZER(5),

  25652.     SQLITE3_MUTEX_INITIALIZER(6),

  25653.     SQLITE3_MUTEX_INITIALIZER(7),

  25654.     SQLITE3_MUTEX_INITIALIZER(8),

  25655.     SQLITE3_MUTEX_INITIALIZER(9),

  25656.     SQLITE3_MUTEX_INITIALIZER(10),

  25657.     SQLITE3_MUTEX_INITIALIZER(11),

  25658.     SQLITE3_MUTEX_INITIALIZER(12),

  25659.     SQLITE3_MUTEX_INITIALIZER(13)

  25660.   };

  25661.   sqlite3_mutex *p;

  25662.   switch( iType ){

  25663.     case SQLITE_MUTEX_RECURSIVE: {

  25664.       p = sqlite3MallocZero( sizeof(*p) );

  25665.       if( p ){

  25666. #ifdef SQLITE_HOMEGROWN_RECURSIVE_MUTEX

  25667.         /* If recursive mutexes are not available, we will have to

  25668.         ** build our own.  See below. */

  25669.         pthread_mutex_init(&p->mutex, 0);

  25670. #else

  25671.         /* Use a recursive mutex if it is available */

  25672.         pthread_mutexattr_t recursiveAttr;

  25673.         pthread_mutexattr_init(&recursiveAttr);

  25674.         pthread_mutexattr_settype(&recursiveAttr, PTHREAD_MUTEX_RECURSIVE);

  25675.         pthread_mutex_init(&p->mutex, &recursiveAttr);

  25676.         pthread_mutexattr_destroy(&recursiveAttr);

  25677. #endif

  25678. #if SQLITE_MUTEX_NREF || defined(SQLITE_ENABLE_API_ARMOR)

  25679.         p->id = SQLITE_MUTEX_RECURSIVE;

  25680. #endif

  25681.       }

  25682.       break;

  25683.     }

  25684.     case SQLITE_MUTEX_FAST: {

  25685.       p = sqlite3MallocZero( sizeof(*p) );

  25686.       if( p ){

  25687.         pthread_mutex_init(&p->mutex, 0);

  25688. #if SQLITE_MUTEX_NREF || defined(SQLITE_ENABLE_API_ARMOR)

  25689.         p->id = SQLITE_MUTEX_FAST;

  25690. #endif

  25691.       }

  25692.       break;

  25693.     }

  25694.     default: {

  25695. #ifdef SQLITE_ENABLE_API_ARMOR

  25696.       if( iType-2<0 || iType-2>=ArraySize(staticMutexes) ){

  25697.         (void)SQLITE_MISUSE_BKPT;

  25698.         return 0;

  25699.       }

  25700. #endif

  25701.       p = &staticMutexes[iType-2];

  25702.       break;

  25703.     }

  25704.   }

  25705. #if SQLITE_MUTEX_NREF || defined(SQLITE_ENABLE_API_ARMOR)

  25706.   assert( p==0 || p->id==iType );

  25707. #endif

  25708.   return p;

  25709. }

  25710. 

  25711. 

  25712. /*

  25713. ** This routine deallocates a previously

  25714. ** allocated mutex.  SQLite is careful to deallocate every

  25715. ** mutex that it allocates.

  25716. */

  25717. static void pthreadMutexFree(sqlite3_mutex *p){

  25718.   assert( p->nRef==0 );

  25719. #if SQLITE_ENABLE_API_ARMOR

  25720.   if( p->id==SQLITE_MUTEX_FAST || p->id==SQLITE_MUTEX_RECURSIVE )

  25721. #endif

  25722.   {

  25723.     pthread_mutex_destroy(&p->mutex);

  25724.     sqlite3_free(p);

  25725.   }

  25726. #ifdef SQLITE_ENABLE_API_ARMOR

  25727.   else{

  25728.     (void)SQLITE_MISUSE_BKPT;

  25729.   }

  25730. #endif

  25731. }

  25732. 

  25733. /*

  25734. ** The sqlite3_mutex_enter() and sqlite3_mutex_try() routines attempt

  25735. ** to enter a mutex.  If another thread is already within the mutex,

  25736. ** sqlite3_mutex_enter() will block and sqlite3_mutex_try() will return

  25737. ** SQLITE_BUSY.  The sqlite3_mutex_try() interface returns SQLITE_OK

  25738. ** upon successful entry.  Mutexes created using SQLITE_MUTEX_RECURSIVE can

  25739. ** be entered multiple times by the same thread.  In such cases the,

  25740. ** mutex must be exited an equal number of times before another thread

  25741. ** can enter.  If the same thread tries to enter any other kind of mutex

  25742. ** more than once, the behavior is undefined.

  25743. */

  25744. static void pthreadMutexEnter(sqlite3_mutex *p){

  25745.   assert( p->id==SQLITE_MUTEX_RECURSIVE || pthreadMutexNotheld(p) );

  25746. 

  25747. #ifdef SQLITE_HOMEGROWN_RECURSIVE_MUTEX

  25748.   /* If recursive mutexes are not available, then we have to grow

  25749.   ** our own.  This implementation assumes that pthread_equal()

  25750.   ** is atomic - that it cannot be deceived into thinking self

  25751.   ** and p->owner are equal if p->owner changes between two values

  25752.   ** that are not equal to self while the comparison is taking place.

  25753.   ** This implementation also assumes a coherent cache - that 

  25754.   ** separate processes cannot read different values from the same

  25755.   ** address at the same time.  If either of these two conditions

  25756.   ** are not met, then the mutexes will fail and problems will result.

  25757.   */

  25758.   {

  25759.     pthread_t self = pthread_self();

  25760.     if( p->nRef>0 && pthread_equal(p->owner, self) ){

  25761.       p->nRef++;

  25762.     }else{

  25763.       pthread_mutex_lock(&p->mutex);

  25764.       assert( p->nRef==0 );

  25765.       p->owner = self;

  25766.       p->nRef = 1;

  25767.     }

  25768.   }

  25769. #else

  25770.   /* Use the built-in recursive mutexes if they are available.

  25771.   */

  25772.   pthread_mutex_lock(&p->mutex);

  25773. #if SQLITE_MUTEX_NREF

  25774.   assert( p->nRef>0 || p->owner==0 );

  25775.   p->owner = pthread_self();

  25776.   p->nRef++;

  25777. #endif

  25778. #endif

  25779. 

  25780. #ifdef SQLITE_DEBUG

  25781.   if( p->trace ){

  25782.     printf("enter mutex %p (%d) with nRef=%d\n", p, p->trace, p->nRef);

  25783.   }

  25784. #endif

  25785. }

  25786. static int pthreadMutexTry(sqlite3_mutex *p){

  25787.   int rc;

  25788.   assert( p->id==SQLITE_MUTEX_RECURSIVE || pthreadMutexNotheld(p) );

  25789. 

  25790. #ifdef SQLITE_HOMEGROWN_RECURSIVE_MUTEX

  25791.   /* If recursive mutexes are not available, then we have to grow

  25792.   ** our own.  This implementation assumes that pthread_equal()

  25793.   ** is atomic - that it cannot be deceived into thinking self

  25794.   ** and p->owner are equal if p->owner changes between two values

  25795.   ** that are not equal to self while the comparison is taking place.

  25796.   ** This implementation also assumes a coherent cache - that 

  25797.   ** separate processes cannot read different values from the same

  25798.   ** address at the same time.  If either of these two conditions

  25799.   ** are not met, then the mutexes will fail and problems will result.

  25800.   */

  25801.   {

  25802.     pthread_t self = pthread_self();

  25803.     if( p->nRef>0 && pthread_equal(p->owner, self) ){

  25804.       p->nRef++;

  25805.       rc = SQLITE_OK;

  25806.     }else if( pthread_mutex_trylock(&p->mutex)==0 ){

  25807.       assert( p->nRef==0 );

  25808.       p->owner = self;

  25809.       p->nRef = 1;

  25810.       rc = SQLITE_OK;

  25811.     }else{

  25812.       rc = SQLITE_BUSY;

  25813.     }

  25814.   }

  25815. #else

  25816.   /* Use the built-in recursive mutexes if they are available.

  25817.   */

  25818.   if( pthread_mutex_trylock(&p->mutex)==0 ){

  25819. #if SQLITE_MUTEX_NREF

  25820.     p->owner = pthread_self();

  25821.     p->nRef++;

  25822. #endif

  25823.     rc = SQLITE_OK;

  25824.   }else{

  25825.     rc = SQLITE_BUSY;

  25826.   }

  25827. #endif

  25828. 

  25829. #ifdef SQLITE_DEBUG

  25830.   if( rc==SQLITE_OK && p->trace ){

  25831.     printf("enter mutex %p (%d) with nRef=%d\n", p, p->trace, p->nRef);

  25832.   }

  25833. #endif

  25834.   return rc;

  25835. }

  25836. 

  25837. /*

  25838. ** The sqlite3_mutex_leave() routine exits a mutex that was

  25839. ** previously entered by the same thread.  The behavior

  25840. ** is undefined if the mutex is not currently entered or

  25841. ** is not currently allocated.  SQLite will never do either.

  25842. */

  25843. static void pthreadMutexLeave(sqlite3_mutex *p){

  25844.   assert( pthreadMutexHeld(p) );

  25845. #if SQLITE_MUTEX_NREF

  25846.   p->nRef--;

  25847.   if( p->nRef==0 ) p->owner = 0;

  25848. #endif

  25849.   assert( p->nRef==0 || p->id==SQLITE_MUTEX_RECURSIVE );

  25850. 

  25851. #ifdef SQLITE_HOMEGROWN_RECURSIVE_MUTEX

  25852.   if( p->nRef==0 ){

  25853.     pthread_mutex_unlock(&p->mutex);

  25854.   }

  25855. #else

  25856.   pthread_mutex_unlock(&p->mutex);

  25857. #endif

  25858. 

  25859. #ifdef SQLITE_DEBUG

  25860.   if( p->trace ){

  25861.     printf("leave mutex %p (%d) with nRef=%d\n", p, p->trace, p->nRef);

  25862.   }

  25863. #endif

  25864. }

  25865. 

  25866. SQLITE_PRIVATE sqlite3_mutex_methods const *sqlite3DefaultMutex(void){

  25867.   static const sqlite3_mutex_methods sMutex = {

  25868.     pthreadMutexInit,

  25869.     pthreadMutexEnd,

  25870.     pthreadMutexAlloc,

  25871.     pthreadMutexFree,

  25872.     pthreadMutexEnter,

  25873.     pthreadMutexTry,

  25874.     pthreadMutexLeave,

  25875. #ifdef SQLITE_DEBUG

  25876.     pthreadMutexHeld,

  25877.     pthreadMutexNotheld

  25878. #else

  25879.     0,

  25880.     0

  25881. #endif

  25882.   };

  25883. 

  25884.   return &sMutex;

  25885. }

  25886. 

  25887. #endif /* SQLITE_MUTEX_PTHREADS */

  25888. 

  25889. /************** End of mutex_unix.c ******************************************/

  25890. /************** Begin file mutex_w32.c ***************************************/

  25891. /*

  25892. ** 2007 August 14

  25893. **

  25894. ** The author disclaims copyright to this source code.  In place of

  25895. ** a legal notice, here is a blessing:

  25896. **

  25897. **    May you do good and not evil.

  25898. **    May you find forgiveness for yourself and forgive others.

  25899. **    May you share freely, never taking more than you give.

  25900. **

  25901. *************************************************************************

  25902. ** This file contains the C functions that implement mutexes for Win32.

  25903. */

  25904. /* #include "sqliteInt.h" */

  25905. 

  25906. #if SQLITE_OS_WIN

  25907. /*

  25908. ** Include code that is common to all os_*.c files

  25909. */

  25910. /************** Include os_common.h in the middle of mutex_w32.c *************/

  25911. /************** Begin file os_common.h ***************************************/

  25912. /*

  25913. ** 2004 May 22

  25914. **

  25915. ** The author disclaims copyright to this source code.  In place of

  25916. ** a legal notice, here is a blessing:

  25917. **

  25918. **    May you do good and not evil.

  25919. **    May you find forgiveness for yourself and forgive others.

  25920. **    May you share freely, never taking more than you give.

  25921. **

  25922. ******************************************************************************

  25923. **

  25924. ** This file contains macros and a little bit of code that is common to

  25925. ** all of the platform-specific files (os_*.c) and is #included into those

  25926. ** files.

  25927. **

  25928. ** This file should be #included by the os_*.c files only.  It is not a

  25929. ** general purpose header file.

  25930. */

  25931. #ifndef _OS_COMMON_H_

  25932. #define _OS_COMMON_H_

  25933. 

  25934. /*

  25935. ** At least two bugs have slipped in because we changed the MEMORY_DEBUG

  25936. ** macro to SQLITE_DEBUG and some older makefiles have not yet made the

  25937. ** switch.  The following code should catch this problem at compile-time.

  25938. */

  25939. #ifdef MEMORY_DEBUG

  25940. # error "The MEMORY_DEBUG macro is obsolete.  Use SQLITE_DEBUG instead."

  25941. #endif

  25942. 

  25943. /*

  25944. ** Macros for performance tracing.  Normally turned off.  Only works

  25945. ** on i486 hardware.

  25946. */

  25947. #ifdef SQLITE_PERFORMANCE_TRACE

  25948. 

  25949. /*

  25950. ** hwtime.h contains inline assembler code for implementing

  25951. ** high-performance timing routines.

  25952. */

  25953. /************** Include hwtime.h in the middle of os_common.h ****************/

  25954. /************** Begin file hwtime.h ******************************************/

  25955. /*

  25956. ** 2008 May 27

  25957. **

  25958. ** The author disclaims copyright to this source code.  In place of

  25959. ** a legal notice, here is a blessing:

  25960. **

  25961. **    May you do good and not evil.

  25962. **    May you find forgiveness for yourself and forgive others.

  25963. **    May you share freely, never taking more than you give.

  25964. **

  25965. ******************************************************************************

  25966. **

  25967. ** This file contains inline asm code for retrieving "high-performance"

  25968. ** counters for x86 class CPUs.

  25969. */

  25970. #ifndef SQLITE_HWTIME_H

  25971. #define SQLITE_HWTIME_H

  25972. 

  25973. /*

  25974. ** The following routine only works on pentium-class (or newer) processors.

  25975. ** It uses the RDTSC opcode to read the cycle count value out of the

  25976. ** processor and returns that value.  This can be used for high-res

  25977. ** profiling.

  25978. */

  25979. #if (defined(__GNUC__) || defined(_MSC_VER)) && \

  25980.       (defined(i386) || defined(__i386__) || defined(_M_IX86))

  25981. 

  25982.   #if defined(__GNUC__)

  25983. 

  25984.   __inline__ sqlite_uint64 sqlite3Hwtime(void){

  25985.      unsigned int lo, hi;

  25986.      __asm__ __volatile__ ("rdtsc" : "=a" (lo), "=d" (hi));

  25987.      return (sqlite_uint64)hi << 32 | lo;

  25988.   }

  25989. 

  25990.   #elif defined(_MSC_VER)

  25991. 

  25992.   __declspec(naked) __inline sqlite_uint64 __cdecl sqlite3Hwtime(void){

  25993.      __asm {

  25994.         rdtsc

  25995.         ret       ; return value at EDX:EAX

  25996.      }

  25997.   }

  25998. 

  25999.   #endif

  26000. 

  26001. #elif (defined(__GNUC__) && defined(__x86_64__))

  26002. 

  26003.   __inline__ sqlite_uint64 sqlite3Hwtime(void){

  26004.       unsigned long val;

  26005.       __asm__ __volatile__ ("rdtsc" : "=A" (val));

  26006.       return val;

  26007.   }

  26008.  

  26009. #elif (defined(__GNUC__) && defined(__ppc__))

  26010. 

  26011.   __inline__ sqlite_uint64 sqlite3Hwtime(void){

  26012.       unsigned long long retval;

  26013.       unsigned long junk;

  26014.       __asm__ __volatile__ ("\n\

  26015.           1:      mftbu   %1\n\

  26016.                   mftb    %L0\n\

  26017.                   mftbu   %0\n\

  26018.                   cmpw    %0,%1\n\

  26019.                   bne     1b"

  26020.                   : "=r" (retval), "=r" (junk));

  26021.       return retval;

  26022.   }

  26023. 

  26024. #else

  26025. 

  26026.   #error Need implementation of sqlite3Hwtime() for your platform.

  26027. 

  26028.   /*

  26029.   ** To compile without implementing sqlite3Hwtime() for your platform,

  26030.   ** you can remove the above #error and use the following

  26031.   ** stub function.  You will lose timing support for many

  26032.   ** of the debugging and testing utilities, but it should at

  26033.   ** least compile and run.

  26034.   */

  26035. SQLITE_PRIVATE   sqlite_uint64 sqlite3Hwtime(void){ return ((sqlite_uint64)0); }

  26036. 

  26037. #endif

  26038. 

  26039. #endif /* !defined(SQLITE_HWTIME_H) */

  26040. 

  26041. /************** End of hwtime.h **********************************************/

  26042. /************** Continuing where we left off in os_common.h ******************/

  26043. 

  26044. static sqlite_uint64 g_start;

  26045. static sqlite_uint64 g_elapsed;

  26046. #define TIMER_START       g_start=sqlite3Hwtime()

  26047. #define TIMER_END         g_elapsed=sqlite3Hwtime()-g_start

  26048. #define TIMER_ELAPSED     g_elapsed

  26049. #else

  26050. #define TIMER_START

  26051. #define TIMER_END

  26052. #define TIMER_ELAPSED     ((sqlite_uint64)0)

  26053. #endif

  26054. 

  26055. /*

  26056. ** If we compile with the SQLITE_TEST macro set, then the following block

  26057. ** of code will give us the ability to simulate a disk I/O error.  This

  26058. ** is used for testing the I/O recovery logic.

  26059. */

  26060. #if defined(SQLITE_TEST)

  26061. SQLITE_API extern int sqlite3_io_error_hit;

  26062. SQLITE_API extern int sqlite3_io_error_hardhit;

  26063. SQLITE_API extern int sqlite3_io_error_pending;

  26064. SQLITE_API extern int sqlite3_io_error_persist;

  26065. SQLITE_API extern int sqlite3_io_error_benign;

  26066. SQLITE_API extern int sqlite3_diskfull_pending;

  26067. SQLITE_API extern int sqlite3_diskfull;

  26068. #define SimulateIOErrorBenign(X) sqlite3_io_error_benign=(X)

  26069. #define SimulateIOError(CODE)  \

  26070.   if( (sqlite3_io_error_persist && sqlite3_io_error_hit) \

  26071.        || sqlite3_io_error_pending-- == 1 )  \

  26072.               { local_ioerr(); CODE; }

  26073. static void local_ioerr(){

  26074.   IOTRACE(("IOERR\n"));

  26075.   sqlite3_io_error_hit++;

  26076.   if( !sqlite3_io_error_benign ) sqlite3_io_error_hardhit++;

  26077. }

  26078. #define SimulateDiskfullError(CODE) \

  26079.    if( sqlite3_diskfull_pending ){ \

  26080.      if( sqlite3_diskfull_pending == 1 ){ \

  26081.        local_ioerr(); \

  26082.        sqlite3_diskfull = 1; \

  26083.        sqlite3_io_error_hit = 1; \

  26084.        CODE; \

  26085.      }else{ \

  26086.        sqlite3_diskfull_pending--; \

  26087.      } \

  26088.    }

  26089. #else

  26090. #define SimulateIOErrorBenign(X)

  26091. #define SimulateIOError(A)

  26092. #define SimulateDiskfullError(A)

  26093. #endif /* defined(SQLITE_TEST) */

  26094. 

  26095. /*

  26096. ** When testing, keep a count of the number of open files.

  26097. */

  26098. #if defined(SQLITE_TEST)

  26099. SQLITE_API extern int sqlite3_open_file_count;

  26100. #define OpenCounter(X)  sqlite3_open_file_count+=(X)

  26101. #else

  26102. #define OpenCounter(X)

  26103. #endif /* defined(SQLITE_TEST) */

  26104. 

  26105. #endif /* !defined(_OS_COMMON_H_) */

  26106. 

  26107. /************** End of os_common.h *******************************************/

  26108. /************** Continuing where we left off in mutex_w32.c ******************/

  26109. 

  26110. /*

  26111. ** Include the header file for the Windows VFS.

  26112. */

  26113. /************** Include os_win.h in the middle of mutex_w32.c ****************/

  26114. /************** Begin file os_win.h ******************************************/

  26115. /*

  26116. ** 2013 November 25

  26117. **

  26118. ** The author disclaims copyright to this source code.  In place of

  26119. ** a legal notice, here is a blessing:

  26120. **

  26121. **    May you do good and not evil.

  26122. **    May you find forgiveness for yourself and forgive others.

  26123. **    May you share freely, never taking more than you give.

  26124. **

  26125. ******************************************************************************

  26126. **

  26127. ** This file contains code that is specific to Windows.

  26128. */

  26129. #ifndef SQLITE_OS_WIN_H

  26130. #define SQLITE_OS_WIN_H

  26131. 

  26132. /*

  26133. ** Include the primary Windows SDK header file.

  26134. */

  26135. #include "windows.h"

  26136. 

  26137. #ifdef __CYGWIN__

  26138. # include <sys/cygwin.h>

  26139. # include <errno.h> /* amalgamator: dontcache */

  26140. #endif

  26141. 

  26142. /*

  26143. ** Determine if we are dealing with Windows NT.

  26144. **

  26145. ** We ought to be able to determine if we are compiling for Windows 9x or

  26146. ** Windows NT using the _WIN32_WINNT macro as follows:

  26147. **

  26148. ** #if defined(_WIN32_WINNT)

  26149. ** # define SQLITE_OS_WINNT 1

  26150. ** #else

  26151. ** # define SQLITE_OS_WINNT 0

  26152. ** #endif

  26153. **

  26154. ** However, Visual Studio 2005 does not set _WIN32_WINNT by default, as

  26155. ** it ought to, so the above test does not work.  We'll just assume that

  26156. ** everything is Windows NT unless the programmer explicitly says otherwise

  26157. ** by setting SQLITE_OS_WINNT to 0.

  26158. */

  26159. #if SQLITE_OS_WIN && !defined(SQLITE_OS_WINNT)

  26160. # define SQLITE_OS_WINNT 1

  26161. #endif

  26162. 

  26163. /*

  26164. ** Determine if we are dealing with Windows CE - which has a much reduced

  26165. ** API.

  26166. */

  26167. #if defined(_WIN32_WCE)

  26168. # define SQLITE_OS_WINCE 1

  26169. #else

  26170. # define SQLITE_OS_WINCE 0

  26171. #endif

  26172. 

  26173. /*

  26174. ** Determine if we are dealing with WinRT, which provides only a subset of

  26175. ** the full Win32 API.

  26176. */

  26177. #if !defined(SQLITE_OS_WINRT)

  26178. # define SQLITE_OS_WINRT 0

  26179. #endif

  26180. 

  26181. /*

  26182. ** For WinCE, some API function parameters do not appear to be declared as

  26183. ** volatile.

  26184. */

  26185. #if SQLITE_OS_WINCE

  26186. # define SQLITE_WIN32_VOLATILE

  26187. #else

  26188. # define SQLITE_WIN32_VOLATILE volatile

  26189. #endif

  26190. 

  26191. /*

  26192. ** For some Windows sub-platforms, the _beginthreadex() / _endthreadex()

  26193. ** functions are not available (e.g. those not using MSVC, Cygwin, etc).

  26194. */

  26195. #if SQLITE_OS_WIN && !SQLITE_OS_WINCE && !SQLITE_OS_WINRT && \

  26196.     SQLITE_THREADSAFE>0 && !defined(__CYGWIN__)

  26197. # define SQLITE_OS_WIN_THREADS 1

  26198. #else

  26199. # define SQLITE_OS_WIN_THREADS 0

  26200. #endif

  26201. 

  26202. #endif /* SQLITE_OS_WIN_H */

  26203. 

  26204. /************** End of os_win.h **********************************************/

  26205. /************** Continuing where we left off in mutex_w32.c ******************/

  26206. #endif

  26207. 

  26208. /*

  26209. ** The code in this file is only used if we are compiling multithreaded

  26210. ** on a Win32 system.

  26211. */

  26212. #ifdef SQLITE_MUTEX_W32

  26213. 

  26214. /*

  26215. ** Each recursive mutex is an instance of the following structure.

  26216. */

  26217. struct sqlite3_mutex {

  26218.   CRITICAL_SECTION mutex;    /* Mutex controlling the lock */

  26219.   int id;                    /* Mutex type */

  26220. #ifdef SQLITE_DEBUG

  26221.   volatile int nRef;         /* Number of enterances */

  26222.   volatile DWORD owner;      /* Thread holding this mutex */

  26223.   volatile LONG trace;       /* True to trace changes */

  26224. #endif

  26225. };

  26226. 

  26227. /*

  26228. ** These are the initializer values used when declaring a "static" mutex

  26229. ** on Win32.  It should be noted that all mutexes require initialization

  26230. ** on the Win32 platform.

  26231. */

  26232. #define SQLITE_W32_MUTEX_INITIALIZER { 0 }

  26233. 

  26234. #ifdef SQLITE_DEBUG

  26235. #define SQLITE3_MUTEX_INITIALIZER(id) { SQLITE_W32_MUTEX_INITIALIZER, id, \

  26236.                                     0L, (DWORD)0, 0 }

  26237. #else

  26238. #define SQLITE3_MUTEX_INITIALIZER(id) { SQLITE_W32_MUTEX_INITIALIZER, id }

  26239. #endif

  26240. 

  26241. #ifdef SQLITE_DEBUG

  26242. /*

  26243. ** The sqlite3_mutex_held() and sqlite3_mutex_notheld() routine are

  26244. ** intended for use only inside assert() statements.

  26245. */

  26246. static int winMutexHeld(sqlite3_mutex *p){

  26247.   return p->nRef!=0 && p->owner==GetCurrentThreadId();

  26248. }

  26249. 

  26250. static int winMutexNotheld2(sqlite3_mutex *p, DWORD tid){

  26251.   return p->nRef==0 || p->owner!=tid;

  26252. }

  26253. 

  26254. static int winMutexNotheld(sqlite3_mutex *p){

  26255.   DWORD tid = GetCurrentThreadId();

  26256.   return winMutexNotheld2(p, tid);

  26257. }

  26258. #endif

  26259. 

  26260. /*

  26261. ** Try to provide a memory barrier operation, needed for initialization

  26262. ** and also for the xShmBarrier method of the VFS in cases when SQLite is

  26263. ** compiled without mutexes (SQLITE_THREADSAFE=0).

  26264. */

  26265. SQLITE_PRIVATE void sqlite3MemoryBarrier(void){

  26266. #if defined(SQLITE_MEMORY_BARRIER)

  26267.   SQLITE_MEMORY_BARRIER;

  26268. #elif defined(__GNUC__)

  26269.   __sync_synchronize();

  26270. #elif MSVC_VERSION>=1300

  26271.   _ReadWriteBarrier();

  26272. #elif defined(MemoryBarrier)

  26273.   MemoryBarrier();

  26274. #endif

  26275. }

  26276. 

  26277. /*

  26278. ** Initialize and deinitialize the mutex subsystem.

  26279. */

  26280. static sqlite3_mutex winMutex_staticMutexes[] = {

  26281.   SQLITE3_MUTEX_INITIALIZER(2),

  26282.   SQLITE3_MUTEX_INITIALIZER(3),

  26283.   SQLITE3_MUTEX_INITIALIZER(4),

  26284.   SQLITE3_MUTEX_INITIALIZER(5),

  26285.   SQLITE3_MUTEX_INITIALIZER(6),

  26286.   SQLITE3_MUTEX_INITIALIZER(7),

  26287.   SQLITE3_MUTEX_INITIALIZER(8),

  26288.   SQLITE3_MUTEX_INITIALIZER(9),

  26289.   SQLITE3_MUTEX_INITIALIZER(10),

  26290.   SQLITE3_MUTEX_INITIALIZER(11),

  26291.   SQLITE3_MUTEX_INITIALIZER(12),

  26292.   SQLITE3_MUTEX_INITIALIZER(13)

  26293. };

  26294. 

  26295. static int winMutex_isInit = 0;

  26296. static int winMutex_isNt = -1; /* <0 means "need to query" */

  26297. 

  26298. /* As the winMutexInit() and winMutexEnd() functions are called as part

  26299. ** of the sqlite3_initialize() and sqlite3_shutdown() processing, the

  26300. ** "interlocked" magic used here is probably not strictly necessary.

  26301. */

  26302. static LONG SQLITE_WIN32_VOLATILE winMutex_lock = 0;

  26303. 

  26304. SQLITE_API int sqlite3_win32_is_nt(void); /* os_win.c */

  26305. SQLITE_API void sqlite3_win32_sleep(DWORD milliseconds); /* os_win.c */

  26306. 

  26307. static int winMutexInit(void){

  26308.   /* The first to increment to 1 does actual initialization */

  26309.   if( InterlockedCompareExchange(&winMutex_lock, 1, 0)==0 ){

  26310.     int i;

  26311.     for(i=0; i<ArraySize(winMutex_staticMutexes); i++){

  26312. #if SQLITE_OS_WINRT

  26313.       InitializeCriticalSectionEx(&winMutex_staticMutexes[i].mutex, 0, 0);

  26314. #else

  26315.       InitializeCriticalSection(&winMutex_staticMutexes[i].mutex);

  26316. #endif

  26317.     }

  26318.     winMutex_isInit = 1;

  26319.   }else{

  26320.     /* Another thread is (in the process of) initializing the static

  26321.     ** mutexes */

  26322.     while( !winMutex_isInit ){

  26323.       sqlite3_win32_sleep(1);

  26324.     }

  26325.   }

  26326.   return SQLITE_OK;

  26327. }

  26328. 

  26329. static int winMutexEnd(void){

  26330.   /* The first to decrement to 0 does actual shutdown

  26331.   ** (which should be the last to shutdown.) */

  26332.   if( InterlockedCompareExchange(&winMutex_lock, 0, 1)==1 ){

  26333.     if( winMutex_isInit==1 ){

  26334.       int i;

  26335.       for(i=0; i<ArraySize(winMutex_staticMutexes); i++){

  26336.         DeleteCriticalSection(&winMutex_staticMutexes[i].mutex);

  26337.       }

  26338.       winMutex_isInit = 0;

  26339.     }

  26340.   }

  26341.   return SQLITE_OK;

  26342. }

  26343. 

  26344. /*

  26345. ** The sqlite3_mutex_alloc() routine allocates a new

  26346. ** mutex and returns a pointer to it.  If it returns NULL

  26347. ** that means that a mutex could not be allocated.  SQLite

  26348. ** will unwind its stack and return an error.  The argument

  26349. ** to sqlite3_mutex_alloc() is one of these integer constants:

  26350. **

  26351. ** <ul>

  26352. ** <li>  SQLITE_MUTEX_FAST

  26353. ** <li>  SQLITE_MUTEX_RECURSIVE

  26354. ** <li>  SQLITE_MUTEX_STATIC_MASTER

  26355. ** <li>  SQLITE_MUTEX_STATIC_MEM

  26356. ** <li>  SQLITE_MUTEX_STATIC_OPEN

  26357. ** <li>  SQLITE_MUTEX_STATIC_PRNG

  26358. ** <li>  SQLITE_MUTEX_STATIC_LRU

  26359. ** <li>  SQLITE_MUTEX_STATIC_PMEM

  26360. ** <li>  SQLITE_MUTEX_STATIC_APP1

  26361. ** <li>  SQLITE_MUTEX_STATIC_APP2

  26362. ** <li>  SQLITE_MUTEX_STATIC_APP3

  26363. ** <li>  SQLITE_MUTEX_STATIC_VFS1

  26364. ** <li>  SQLITE_MUTEX_STATIC_VFS2

  26365. ** <li>  SQLITE_MUTEX_STATIC_VFS3

  26366. ** </ul>

  26367. **

  26368. ** The first two constants cause sqlite3_mutex_alloc() to create

  26369. ** a new mutex.  The new mutex is recursive when SQLITE_MUTEX_RECURSIVE

  26370. ** is used but not necessarily so when SQLITE_MUTEX_FAST is used.

  26371. ** The mutex implementation does not need to make a distinction

  26372. ** between SQLITE_MUTEX_RECURSIVE and SQLITE_MUTEX_FAST if it does

  26373. ** not want to.  But SQLite will only request a recursive mutex in

  26374. ** cases where it really needs one.  If a faster non-recursive mutex

  26375. ** implementation is available on the host platform, the mutex subsystem

  26376. ** might return such a mutex in response to SQLITE_MUTEX_FAST.

  26377. **

  26378. ** The other allowed parameters to sqlite3_mutex_alloc() each return

  26379. ** a pointer to a static preexisting mutex.  Six static mutexes are

  26380. ** used by the current version of SQLite.  Future versions of SQLite

  26381. ** may add additional static mutexes.  Static mutexes are for internal

  26382. ** use by SQLite only.  Applications that use SQLite mutexes should

  26383. ** use only the dynamic mutexes returned by SQLITE_MUTEX_FAST or

  26384. ** SQLITE_MUTEX_RECURSIVE.

  26385. **

  26386. ** Note that if one of the dynamic mutex parameters (SQLITE_MUTEX_FAST

  26387. ** or SQLITE_MUTEX_RECURSIVE) is used then sqlite3_mutex_alloc()

  26388. ** returns a different mutex on every call.  But for the static

  26389. ** mutex types, the same mutex is returned on every call that has

  26390. ** the same type number.

  26391. */

  26392. static sqlite3_mutex *winMutexAlloc(int iType){

  26393.   sqlite3_mutex *p;

  26394. 

  26395.   switch( iType ){

  26396.     case SQLITE_MUTEX_FAST:

  26397.     case SQLITE_MUTEX_RECURSIVE: {

  26398.       p = sqlite3MallocZero( sizeof(*p) );

  26399.       if( p ){

  26400.         p->id = iType;

  26401. #ifdef SQLITE_DEBUG

  26402. #ifdef SQLITE_WIN32_MUTEX_TRACE_DYNAMIC

  26403.         p->trace = 1;

  26404. #endif

  26405. #endif

  26406. #if SQLITE_OS_WINRT

  26407.         InitializeCriticalSectionEx(&p->mutex, 0, 0);

  26408. #else

  26409.         InitializeCriticalSection(&p->mutex);

  26410. #endif

  26411.       }

  26412.       break;

  26413.     }

  26414.     default: {

  26415. #ifdef SQLITE_ENABLE_API_ARMOR

  26416.       if( iType-2<0 || iType-2>=ArraySize(winMutex_staticMutexes) ){

  26417.         (void)SQLITE_MISUSE_BKPT;

  26418.         return 0;

  26419.       }

  26420. #endif

  26421.       p = &winMutex_staticMutexes[iType-2];

  26422. #ifdef SQLITE_DEBUG

  26423. #ifdef SQLITE_WIN32_MUTEX_TRACE_STATIC

  26424.       InterlockedCompareExchange(&p->trace, 1, 0);

  26425. #endif

  26426. #endif

  26427.       break;

  26428.     }

  26429.   }

  26430.   assert( p==0 || p->id==iType );

  26431.   return p;

  26432. }

  26433. 

  26434. 

  26435. /*

  26436. ** This routine deallocates a previously

  26437. ** allocated mutex.  SQLite is careful to deallocate every

  26438. ** mutex that it allocates.

  26439. */

  26440. static void winMutexFree(sqlite3_mutex *p){

  26441.   assert( p );

  26442.   assert( p->nRef==0 && p->owner==0 );

  26443.   if( p->id==SQLITE_MUTEX_FAST || p->id==SQLITE_MUTEX_RECURSIVE ){

  26444.     DeleteCriticalSection(&p->mutex);

  26445.     sqlite3_free(p);

  26446.   }else{

  26447. #ifdef SQLITE_ENABLE_API_ARMOR

  26448.     (void)SQLITE_MISUSE_BKPT;

  26449. #endif

  26450.   }

  26451. }

  26452. 

  26453. /*

  26454. ** The sqlite3_mutex_enter() and sqlite3_mutex_try() routines attempt

  26455. ** to enter a mutex.  If another thread is already within the mutex,

  26456. ** sqlite3_mutex_enter() will block and sqlite3_mutex_try() will return

  26457. ** SQLITE_BUSY.  The sqlite3_mutex_try() interface returns SQLITE_OK

  26458. ** upon successful entry.  Mutexes created using SQLITE_MUTEX_RECURSIVE can

  26459. ** be entered multiple times by the same thread.  In such cases the,

  26460. ** mutex must be exited an equal number of times before another thread

  26461. ** can enter.  If the same thread tries to enter any other kind of mutex

  26462. ** more than once, the behavior is undefined.

  26463. */

  26464. static void winMutexEnter(sqlite3_mutex *p){

  26465. #if defined(SQLITE_DEBUG) || defined(SQLITE_TEST)

  26466.   DWORD tid = GetCurrentThreadId();

  26467. #endif

  26468. #ifdef SQLITE_DEBUG

  26469.   assert( p );

  26470.   assert( p->id==SQLITE_MUTEX_RECURSIVE || winMutexNotheld2(p, tid) );

  26471. #else

  26472.   assert( p );

  26473. #endif

  26474.   assert( winMutex_isInit==1 );

  26475.   EnterCriticalSection(&p->mutex);

  26476. #ifdef SQLITE_DEBUG

  26477.   assert( p->nRef>0 || p->owner==0 );

  26478.   p->owner = tid;

  26479.   p->nRef++;

  26480.   if( p->trace ){

  26481.     OSTRACE(("ENTER-MUTEX tid=%lu, mutex(%d)=%p (%d), nRef=%d\n",

  26482.              tid, p->id, p, p->trace, p->nRef));

  26483.   }

  26484. #endif

  26485. }

  26486. 

  26487. static int winMutexTry(sqlite3_mutex *p){

  26488. #if defined(SQLITE_DEBUG) || defined(SQLITE_TEST)

  26489.   DWORD tid = GetCurrentThreadId();

  26490. #endif

  26491.   int rc = SQLITE_BUSY;

  26492.   assert( p );

  26493.   assert( p->id==SQLITE_MUTEX_RECURSIVE || winMutexNotheld2(p, tid) );

  26494.   /*

  26495.   ** The sqlite3_mutex_try() routine is very rarely used, and when it

  26496.   ** is used it is merely an optimization.  So it is OK for it to always

  26497.   ** fail.

  26498.   **

  26499.   ** The TryEnterCriticalSection() interface is only available on WinNT.

  26500.   ** And some windows compilers complain if you try to use it without

  26501.   ** first doing some #defines that prevent SQLite from building on Win98.

  26502.   ** For that reason, we will omit this optimization for now.  See

  26503.   ** ticket #2685.

  26504.   */

  26505. #if defined(_WIN32_WINNT) && _WIN32_WINNT >= 0x0400

  26506.   assert( winMutex_isInit==1 );

  26507.   assert( winMutex_isNt>=-1 && winMutex_isNt<=1 );

  26508.   if( winMutex_isNt<0 ){

  26509.     winMutex_isNt = sqlite3_win32_is_nt();

  26510.   }

  26511.   assert( winMutex_isNt==0 || winMutex_isNt==1 );

  26512.   if( winMutex_isNt && TryEnterCriticalSection(&p->mutex) ){

  26513. #ifdef SQLITE_DEBUG

  26514.     p->owner = tid;

  26515.     p->nRef++;

  26516. #endif

  26517.     rc = SQLITE_OK;

  26518.   }

  26519. #else

  26520.   UNUSED_PARAMETER(p);

  26521. #endif

  26522. #ifdef SQLITE_DEBUG

  26523.   if( p->trace ){

  26524.     OSTRACE(("TRY-MUTEX tid=%lu, mutex(%d)=%p (%d), owner=%lu, nRef=%d, rc=%s\n",

  26525.              tid, p->id, p, p->trace, p->owner, p->nRef, sqlite3ErrName(rc)));

  26526.   }

  26527. #endif

  26528.   return rc;

  26529. }

  26530. 

  26531. /*

  26532. ** The sqlite3_mutex_leave() routine exits a mutex that was

  26533. ** previously entered by the same thread.  The behavior

  26534. ** is undefined if the mutex is not currently entered or

  26535. ** is not currently allocated.  SQLite will never do either.

  26536. */

  26537. static void winMutexLeave(sqlite3_mutex *p){

  26538. #if defined(SQLITE_DEBUG) || defined(SQLITE_TEST)

  26539.   DWORD tid = GetCurrentThreadId();

  26540. #endif

  26541.   assert( p );

  26542. #ifdef SQLITE_DEBUG

  26543.   assert( p->nRef>0 );

  26544.   assert( p->owner==tid );

  26545.   p->nRef--;

  26546.   if( p->nRef==0 ) p->owner = 0;

  26547.   assert( p->nRef==0 || p->id==SQLITE_MUTEX_RECURSIVE );

  26548. #endif

  26549.   assert( winMutex_isInit==1 );

  26550.   LeaveCriticalSection(&p->mutex);

  26551. #ifdef SQLITE_DEBUG

  26552.   if( p->trace ){

  26553.     OSTRACE(("LEAVE-MUTEX tid=%lu, mutex(%d)=%p (%d), nRef=%d\n",

  26554.              tid, p->id, p, p->trace, p->nRef));

  26555.   }

  26556. #endif

  26557. }

  26558. 

  26559. SQLITE_PRIVATE sqlite3_mutex_methods const *sqlite3DefaultMutex(void){

  26560.   static const sqlite3_mutex_methods sMutex = {

  26561.     winMutexInit,

  26562.     winMutexEnd,

  26563.     winMutexAlloc,

  26564.     winMutexFree,

  26565.     winMutexEnter,

  26566.     winMutexTry,

  26567.     winMutexLeave,

  26568. #ifdef SQLITE_DEBUG

  26569.     winMutexHeld,

  26570.     winMutexNotheld

  26571. #else

  26572.     0,

  26573.     0

  26574. #endif

  26575.   };

  26576.   return &sMutex;

  26577. }

  26578. 

  26579. #endif /* SQLITE_MUTEX_W32 */

  26580. 

  26581. /************** End of mutex_w32.c *******************************************/

  26582. /************** Begin file malloc.c ******************************************/

  26583. /*

  26584. ** 2001 September 15

  26585. **

  26586. ** The author disclaims copyright to this source code.  In place of

  26587. ** a legal notice, here is a blessing:

  26588. **

  26589. **    May you do good and not evil.

  26590. **    May you find forgiveness for yourself and forgive others.

  26591. **    May you share freely, never taking more than you give.

  26592. **

  26593. *************************************************************************

  26594. **

  26595. ** Memory allocation functions used throughout sqlite.

  26596. */

  26597. /* #include "sqliteInt.h" */

  26598. /* #include <stdarg.h> */

  26599. 

  26600. /*

  26601. ** Attempt to release up to n bytes of non-essential memory currently

  26602. ** held by SQLite. An example of non-essential memory is memory used to

  26603. ** cache database pages that are not currently in use.

  26604. */

  26605. SQLITE_API int sqlite3_release_memory(int n){

  26606. #ifdef SQLITE_ENABLE_MEMORY_MANAGEMENT

  26607.   return sqlite3PcacheReleaseMemory(n);

  26608. #else

  26609.   /* IMPLEMENTATION-OF: R-34391-24921 The sqlite3_release_memory() routine

  26610.   ** is a no-op returning zero if SQLite is not compiled with

  26611.   ** SQLITE_ENABLE_MEMORY_MANAGEMENT. */

  26612.   UNUSED_PARAMETER(n);

  26613.   return 0;

  26614. #endif

  26615. }

  26616. 

  26617. /*

  26618. ** State information local to the memory allocation subsystem.

  26619. */

  26620. static SQLITE_WSD struct Mem0Global {

  26621.   sqlite3_mutex *mutex;         /* Mutex to serialize access */

  26622.   sqlite3_int64 alarmThreshold; /* The soft heap limit */

  26623. 

  26624.   /*

  26625.   ** True if heap is nearly "full" where "full" is defined by the

  26626.   ** sqlite3_soft_heap_limit() setting.

  26627.   */

  26628.   int nearlyFull;

  26629. } mem0 = { 0, 0, 0 };

  26630. 

  26631. #define mem0 GLOBAL(struct Mem0Global, mem0)

  26632. 

  26633. /*

  26634. ** Return the memory allocator mutex. sqlite3_status() needs it.

  26635. */

  26636. SQLITE_PRIVATE sqlite3_mutex *sqlite3MallocMutex(void){

  26637.   return mem0.mutex;

  26638. }

  26639. 

  26640. #ifndef SQLITE_OMIT_DEPRECATED

  26641. /*

  26642. ** Deprecated external interface.  It used to set an alarm callback

  26643. ** that was invoked when memory usage grew too large.  Now it is a

  26644. ** no-op.

  26645. */

  26646. SQLITE_API int sqlite3_memory_alarm(

  26647.   void(*xCallback)(void *pArg, sqlite3_int64 used,int N),

  26648.   void *pArg,

  26649.   sqlite3_int64 iThreshold

  26650. ){

  26651.   (void)xCallback;

  26652.   (void)pArg;

  26653.   (void)iThreshold;

  26654.   return SQLITE_OK;

  26655. }

  26656. #endif

  26657. 

  26658. /*

  26659. ** Set the soft heap-size limit for the library. Passing a zero or 

  26660. ** negative value indicates no limit.

  26661. */

  26662. SQLITE_API sqlite3_int64 sqlite3_soft_heap_limit64(sqlite3_int64 n){

  26663.   sqlite3_int64 priorLimit;

  26664.   sqlite3_int64 excess;

  26665.   sqlite3_int64 nUsed;

  26666. #ifndef SQLITE_OMIT_AUTOINIT

  26667.   int rc = sqlite3_initialize();

  26668.   if( rc ) return -1;

  26669. #endif

  26670.   sqlite3_mutex_enter(mem0.mutex);

  26671.   priorLimit = mem0.alarmThreshold;

  26672.   if( n<0 ){

  26673.     sqlite3_mutex_leave(mem0.mutex);

  26674.     return priorLimit;

  26675.   }

  26676.   mem0.alarmThreshold = n;

  26677.   nUsed = sqlite3StatusValue(SQLITE_STATUS_MEMORY_USED);

  26678.   mem0.nearlyFull = (n>0 && n<=nUsed);

  26679.   sqlite3_mutex_leave(mem0.mutex);

  26680.   excess = sqlite3_memory_used() - n;

  26681.   if( excess>0 ) sqlite3_release_memory((int)(excess & 0x7fffffff));

  26682.   return priorLimit;

  26683. }

  26684. SQLITE_API void sqlite3_soft_heap_limit(int n){

  26685.   if( n<0 ) n = 0;

  26686.   sqlite3_soft_heap_limit64(n);

  26687. }

  26688. 

  26689. /*

  26690. ** Initialize the memory allocation subsystem.

  26691. */

  26692. SQLITE_PRIVATE int sqlite3MallocInit(void){

  26693.   int rc;

  26694.   if( sqlite3GlobalConfig.m.xMalloc==0 ){

  26695.     sqlite3MemSetDefault();

  26696.   }

  26697.   memset(&mem0, 0, sizeof(mem0));

  26698.   mem0.mutex = sqlite3MutexAlloc(SQLITE_MUTEX_STATIC_MEM);

  26699.   if( sqlite3GlobalConfig.pPage==0 || sqlite3GlobalConfig.szPage<512

  26700.       || sqlite3GlobalConfig.nPage<=0 ){

  26701.     sqlite3GlobalConfig.pPage = 0;

  26702.     sqlite3GlobalConfig.szPage = 0;

  26703.   }

  26704.   rc = sqlite3GlobalConfig.m.xInit(sqlite3GlobalConfig.m.pAppData);

  26705.   if( rc!=SQLITE_OK ) memset(&mem0, 0, sizeof(mem0));

  26706.   return rc;

  26707. }

  26708. 

  26709. /*

  26710. ** Return true if the heap is currently under memory pressure - in other

  26711. ** words if the amount of heap used is close to the limit set by

  26712. ** sqlite3_soft_heap_limit().

  26713. */

  26714. SQLITE_PRIVATE int sqlite3HeapNearlyFull(void){

  26715.   return mem0.nearlyFull;

  26716. }

  26717. 

  26718. /*

  26719. ** Deinitialize the memory allocation subsystem.

  26720. */

  26721. SQLITE_PRIVATE void sqlite3MallocEnd(void){

  26722.   if( sqlite3GlobalConfig.m.xShutdown ){

  26723.     sqlite3GlobalConfig.m.xShutdown(sqlite3GlobalConfig.m.pAppData);

  26724.   }

  26725.   memset(&mem0, 0, sizeof(mem0));

  26726. }

  26727. 

  26728. /*

  26729. ** Return the amount of memory currently checked out.

  26730. */

  26731. SQLITE_API sqlite3_int64 sqlite3_memory_used(void){

  26732.   sqlite3_int64 res, mx;

  26733.   sqlite3_status64(SQLITE_STATUS_MEMORY_USED, &res, &mx, 0);

  26734.   return res;

  26735. }

  26736. 

  26737. /*

  26738. ** Return the maximum amount of memory that has ever been

  26739. ** checked out since either the beginning of this process

  26740. ** or since the most recent reset.

  26741. */

  26742. SQLITE_API sqlite3_int64 sqlite3_memory_highwater(int resetFlag){

  26743.   sqlite3_int64 res, mx;

  26744.   sqlite3_status64(SQLITE_STATUS_MEMORY_USED, &res, &mx, resetFlag);

  26745.   return mx;

  26746. }

  26747. 

  26748. /*

  26749. ** Trigger the alarm 

  26750. */

  26751. static void sqlite3MallocAlarm(int nByte){

  26752.   if( mem0.alarmThreshold<=0 ) return;

  26753.   sqlite3_mutex_leave(mem0.mutex);

  26754.   sqlite3_release_memory(nByte);

  26755.   sqlite3_mutex_enter(mem0.mutex);

  26756. }

  26757. 

  26758. /*

  26759. ** Do a memory allocation with statistics and alarms.  Assume the

  26760. ** lock is already held.

  26761. */

  26762. static void mallocWithAlarm(int n, void **pp){

  26763.   void *p;

  26764.   int nFull;

  26765.   assert( sqlite3_mutex_held(mem0.mutex) );

  26766.   assert( n>0 );

  26767. 

  26768.   /* In Firefox (circa 2017-02-08), xRoundup() is remapped to an internal

  26769.   ** implementation of malloc_good_size(), which must be called in debug

  26770.   ** mode and specifically when the DMD "Dark Matter Detector" is enabled

  26771.   ** or else a crash results.  Hence, do not attempt to optimize out the

  26772.   ** following xRoundup() call. */

  26773.   nFull = sqlite3GlobalConfig.m.xRoundup(n);

  26774. 

  26775. #ifdef SQLITE_MAX_MEMORY

  26776.   if( sqlite3StatusValue(SQLITE_STATUS_MEMORY_USED)+nFull>SQLITE_MAX_MEMORY ){

  26777.     *pp = 0;

  26778.     return;

  26779.   }

  26780. #endif

  26781. 

  26782.   sqlite3StatusHighwater(SQLITE_STATUS_MALLOC_SIZE, n);

  26783.   if( mem0.alarmThreshold>0 ){

  26784.     sqlite3_int64 nUsed = sqlite3StatusValue(SQLITE_STATUS_MEMORY_USED);

  26785.     if( nUsed >= mem0.alarmThreshold - nFull ){

  26786.       mem0.nearlyFull = 1;

  26787.       sqlite3MallocAlarm(nFull);

  26788.     }else{

  26789.       mem0.nearlyFull = 0;

  26790.     }

  26791.   }

  26792.   p = sqlite3GlobalConfig.m.xMalloc(nFull);

  26793. #ifdef SQLITE_ENABLE_MEMORY_MANAGEMENT

  26794.   if( p==0 && mem0.alarmThreshold>0 ){

  26795.     sqlite3MallocAlarm(nFull);

  26796.     p = sqlite3GlobalConfig.m.xMalloc(nFull);

  26797.   }

  26798. #endif

  26799.   if( p ){

  26800.     nFull = sqlite3MallocSize(p);

  26801.     sqlite3StatusUp(SQLITE_STATUS_MEMORY_USED, nFull);

  26802.     sqlite3StatusUp(SQLITE_STATUS_MALLOC_COUNT, 1);

  26803.   }

  26804.   *pp = p;

  26805. }

  26806. 

  26807. /*

  26808. ** Allocate memory.  This routine is like sqlite3_malloc() except that it

  26809. ** assumes the memory subsystem has already been initialized.

  26810. */

  26811. SQLITE_PRIVATE void *sqlite3Malloc(u64 n){

  26812.   void *p;

  26813.   if( n==0 || n>=0x7fffff00 ){

  26814.     /* A memory allocation of a number of bytes which is near the maximum

  26815.     ** signed integer value might cause an integer overflow inside of the

  26816.     ** xMalloc().  Hence we limit the maximum size to 0x7fffff00, giving

  26817.     ** 255 bytes of overhead.  SQLite itself will never use anything near

  26818.     ** this amount.  The only way to reach the limit is with sqlite3_malloc() */

  26819.     p = 0;

  26820.   }else if( sqlite3GlobalConfig.bMemstat ){

  26821.     sqlite3_mutex_enter(mem0.mutex);

  26822.     mallocWithAlarm((int)n, &p);

  26823.     sqlite3_mutex_leave(mem0.mutex);

  26824.   }else{

  26825.     p = sqlite3GlobalConfig.m.xMalloc((int)n);

  26826.   }

  26827.   assert( EIGHT_BYTE_ALIGNMENT(p) );  /* IMP: R-11148-40995 */

  26828.   return p;

  26829. }

  26830. 

  26831. /*

  26832. ** This version of the memory allocation is for use by the application.

  26833. ** First make sure the memory subsystem is initialized, then do the

  26834. ** allocation.

  26835. */

  26836. SQLITE_API void *sqlite3_malloc(int n){

  26837. #ifndef SQLITE_OMIT_AUTOINIT

  26838.   if( sqlite3_initialize() ) return 0;

  26839. #endif

  26840.   return n<=0 ? 0 : sqlite3Malloc(n);

  26841. }

  26842. SQLITE_API void *sqlite3_malloc64(sqlite3_uint64 n){

  26843. #ifndef SQLITE_OMIT_AUTOINIT

  26844.   if( sqlite3_initialize() ) return 0;

  26845. #endif

  26846.   return sqlite3Malloc(n);

  26847. }

  26848. 

  26849. /*

  26850. ** TRUE if p is a lookaside memory allocation from db

  26851. */

  26852. #ifndef SQLITE_OMIT_LOOKASIDE

  26853. static int isLookaside(sqlite3 *db, void *p){

  26854.   return SQLITE_WITHIN(p, db->lookaside.pStart, db->lookaside.pEnd);

  26855. }

  26856. #else

  26857. #define isLookaside(A,B) 0

  26858. #endif

  26859. 

  26860. /*

  26861. ** Return the size of a memory allocation previously obtained from

  26862. ** sqlite3Malloc() or sqlite3_malloc().

  26863. */

  26864. SQLITE_PRIVATE int sqlite3MallocSize(void *p){

  26865.   assert( sqlite3MemdebugHasType(p, MEMTYPE_HEAP) );

  26866.   return sqlite3GlobalConfig.m.xSize(p);

  26867. }

  26868. SQLITE_PRIVATE int sqlite3DbMallocSize(sqlite3 *db, void *p){

  26869.   assert( p!=0 );

  26870.   if( db==0 || !isLookaside(db,p) ){

  26871. #ifdef SQLITE_DEBUG

  26872.     if( db==0 ){

  26873.       assert( sqlite3MemdebugNoType(p, (u8)~MEMTYPE_HEAP) );

  26874.       assert( sqlite3MemdebugHasType(p, MEMTYPE_HEAP) );

  26875.     }else{

  26876.       assert( sqlite3MemdebugHasType(p, (MEMTYPE_LOOKASIDE|MEMTYPE_HEAP)) );

  26877.       assert( sqlite3MemdebugNoType(p, (u8)~(MEMTYPE_LOOKASIDE|MEMTYPE_HEAP)) );

  26878.     }

  26879. #endif

  26880.     return sqlite3GlobalConfig.m.xSize(p);

  26881.   }else{

  26882.     assert( sqlite3_mutex_held(db->mutex) );

  26883.     return db->lookaside.sz;

  26884.   }

  26885. }

  26886. SQLITE_API sqlite3_uint64 sqlite3_msize(void *p){

  26887.   assert( sqlite3MemdebugNoType(p, (u8)~MEMTYPE_HEAP) );

  26888.   assert( sqlite3MemdebugHasType(p, MEMTYPE_HEAP) );

  26889.   return p ? sqlite3GlobalConfig.m.xSize(p) : 0;

  26890. }

  26891. 

  26892. /*

  26893. ** Free memory previously obtained from sqlite3Malloc().

  26894. */

  26895. SQLITE_API void sqlite3_free(void *p){

  26896.   if( p==0 ) return;  /* IMP: R-49053-54554 */

  26897.   assert( sqlite3MemdebugHasType(p, MEMTYPE_HEAP) );

  26898.   assert( sqlite3MemdebugNoType(p, (u8)~MEMTYPE_HEAP) );

  26899.   if( sqlite3GlobalConfig.bMemstat ){

  26900.     sqlite3_mutex_enter(mem0.mutex);

  26901.     sqlite3StatusDown(SQLITE_STATUS_MEMORY_USED, sqlite3MallocSize(p));

  26902.     sqlite3StatusDown(SQLITE_STATUS_MALLOC_COUNT, 1);

  26903.     sqlite3GlobalConfig.m.xFree(p);

  26904.     sqlite3_mutex_leave(mem0.mutex);

  26905.   }else{

  26906.     sqlite3GlobalConfig.m.xFree(p);

  26907.   }

  26908. }

  26909. 

  26910. /*

  26911. ** Add the size of memory allocation "p" to the count in

  26912. ** *db->pnBytesFreed.

  26913. */

  26914. static SQLITE_NOINLINE void measureAllocationSize(sqlite3 *db, void *p){

  26915.   *db->pnBytesFreed += sqlite3DbMallocSize(db,p);

  26916. }

  26917. 

  26918. /*

  26919. ** Free memory that might be associated with a particular database

  26920. ** connection.  Calling sqlite3DbFree(D,X) for X==0 is a harmless no-op.

  26921. ** The sqlite3DbFreeNN(D,X) version requires that X be non-NULL.

  26922. */

  26923. SQLITE_PRIVATE void sqlite3DbFreeNN(sqlite3 *db, void *p){

  26924.   assert( db==0 || sqlite3_mutex_held(db->mutex) );

  26925.   assert( p!=0 );

  26926.   if( db ){

  26927.     if( db->pnBytesFreed ){

  26928.       measureAllocationSize(db, p);

  26929.       return;

  26930.     }

  26931.     if( isLookaside(db, p) ){

  26932.       LookasideSlot *pBuf = (LookasideSlot*)p;

  26933. #ifdef SQLITE_DEBUG

  26934.       /* Trash all content in the buffer being freed */

  26935.       memset(p, 0xaa, db->lookaside.sz);

  26936. #endif

  26937.       pBuf->pNext = db->lookaside.pFree;

  26938.       db->lookaside.pFree = pBuf;

  26939.       return;

  26940.     }

  26941.   }

  26942.   assert( sqlite3MemdebugHasType(p, (MEMTYPE_LOOKASIDE|MEMTYPE_HEAP)) );

  26943.   assert( sqlite3MemdebugNoType(p, (u8)~(MEMTYPE_LOOKASIDE|MEMTYPE_HEAP)) );

  26944.   assert( db!=0 || sqlite3MemdebugNoType(p, MEMTYPE_LOOKASIDE) );

  26945.   sqlite3MemdebugSetType(p, MEMTYPE_HEAP);

  26946.   sqlite3_free(p);

  26947. }

  26948. SQLITE_PRIVATE void sqlite3DbFree(sqlite3 *db, void *p){

  26949.   assert( db==0 || sqlite3_mutex_held(db->mutex) );

  26950.   if( p ) sqlite3DbFreeNN(db, p);

  26951. }

  26952. 

  26953. /*

  26954. ** Change the size of an existing memory allocation

  26955. */

  26956. SQLITE_PRIVATE void *sqlite3Realloc(void *pOld, u64 nBytes){

  26957.   int nOld, nNew, nDiff;

  26958.   void *pNew;

  26959.   assert( sqlite3MemdebugHasType(pOld, MEMTYPE_HEAP) );

  26960.   assert( sqlite3MemdebugNoType(pOld, (u8)~MEMTYPE_HEAP) );

  26961.   if( pOld==0 ){

  26962.     return sqlite3Malloc(nBytes); /* IMP: R-04300-56712 */

  26963.   }

  26964.   if( nBytes==0 ){

  26965.     sqlite3_free(pOld); /* IMP: R-26507-47431 */

  26966.     return 0;

  26967.   }

  26968.   if( nBytes>=0x7fffff00 ){

  26969.     /* The 0x7ffff00 limit term is explained in comments on sqlite3Malloc() */

  26970.     return 0;

  26971.   }

  26972.   nOld = sqlite3MallocSize(pOld);

  26973.   /* IMPLEMENTATION-OF: R-46199-30249 SQLite guarantees that the second

  26974.   ** argument to xRealloc is always a value returned by a prior call to

  26975.   ** xRoundup. */

  26976.   nNew = sqlite3GlobalConfig.m.xRoundup((int)nBytes);

  26977.   if( nOld==nNew ){

  26978.     pNew = pOld;

  26979.   }else if( sqlite3GlobalConfig.bMemstat ){

  26980.     sqlite3_mutex_enter(mem0.mutex);

  26981.     sqlite3StatusHighwater(SQLITE_STATUS_MALLOC_SIZE, (int)nBytes);

  26982.     nDiff = nNew - nOld;

  26983.     if( nDiff>0 && sqlite3StatusValue(SQLITE_STATUS_MEMORY_USED) >= 

  26984.           mem0.alarmThreshold-nDiff ){

  26985.       sqlite3MallocAlarm(nDiff);

  26986.     }

  26987.     pNew = sqlite3GlobalConfig.m.xRealloc(pOld, nNew);

  26988.     if( pNew==0 && mem0.alarmThreshold>0 ){

  26989.       sqlite3MallocAlarm((int)nBytes);

  26990.       pNew = sqlite3GlobalConfig.m.xRealloc(pOld, nNew);

  26991.     }

  26992.     if( pNew ){

  26993.       nNew = sqlite3MallocSize(pNew);

  26994.       sqlite3StatusUp(SQLITE_STATUS_MEMORY_USED, nNew-nOld);

  26995.     }

  26996.     sqlite3_mutex_leave(mem0.mutex);

  26997.   }else{

  26998.     pNew = sqlite3GlobalConfig.m.xRealloc(pOld, nNew);

  26999.   }

  27000.   assert( EIGHT_BYTE_ALIGNMENT(pNew) ); /* IMP: R-11148-40995 */

  27001.   return pNew;

  27002. }

  27003. 

  27004. /*

  27005. ** The public interface to sqlite3Realloc.  Make sure that the memory

  27006. ** subsystem is initialized prior to invoking sqliteRealloc.

  27007. */

  27008. SQLITE_API void *sqlite3_realloc(void *pOld, int n){

  27009. #ifndef SQLITE_OMIT_AUTOINIT

  27010.   if( sqlite3_initialize() ) return 0;

  27011. #endif

  27012.   if( n<0 ) n = 0;  /* IMP: R-26507-47431 */

  27013.   return sqlite3Realloc(pOld, n);

  27014. }

  27015. SQLITE_API void *sqlite3_realloc64(void *pOld, sqlite3_uint64 n){

  27016. #ifndef SQLITE_OMIT_AUTOINIT

  27017.   if( sqlite3_initialize() ) return 0;

  27018. #endif

  27019.   return sqlite3Realloc(pOld, n);

  27020. }

  27021. 

  27022. 

  27023. /*

  27024. ** Allocate and zero memory.

  27025. */ 

  27026. SQLITE_PRIVATE void *sqlite3MallocZero(u64 n){

  27027.   void *p = sqlite3Malloc(n);

  27028.   if( p ){

  27029.     memset(p, 0, (size_t)n);

  27030.   }

  27031.   return p;

  27032. }

  27033. 

  27034. /*

  27035. ** Allocate and zero memory.  If the allocation fails, make

  27036. ** the mallocFailed flag in the connection pointer.

  27037. */

  27038. SQLITE_PRIVATE void *sqlite3DbMallocZero(sqlite3 *db, u64 n){

  27039.   void *p;

  27040.   testcase( db==0 );

  27041.   p = sqlite3DbMallocRaw(db, n);

  27042.   if( p ) memset(p, 0, (size_t)n);

  27043.   return p;

  27044. }

  27045. 

  27046. 

  27047. /* Finish the work of sqlite3DbMallocRawNN for the unusual and

  27048. ** slower case when the allocation cannot be fulfilled using lookaside.

  27049. */

  27050. static SQLITE_NOINLINE void *dbMallocRawFinish(sqlite3 *db, u64 n){

  27051.   void *p;

  27052.   assert( db!=0 );

  27053.   p = sqlite3Malloc(n);

  27054.   if( !p ) sqlite3OomFault(db);

  27055.   sqlite3MemdebugSetType(p, 

  27056.          (db->lookaside.bDisable==0) ? MEMTYPE_LOOKASIDE : MEMTYPE_HEAP);

  27057.   return p;

  27058. }

  27059. 

  27060. /*

  27061. ** Allocate memory, either lookaside (if possible) or heap.  

  27062. ** If the allocation fails, set the mallocFailed flag in

  27063. ** the connection pointer.

  27064. **

  27065. ** If db!=0 and db->mallocFailed is true (indicating a prior malloc

  27066. ** failure on the same database connection) then always return 0.

  27067. ** Hence for a particular database connection, once malloc starts

  27068. ** failing, it fails consistently until mallocFailed is reset.

  27069. ** This is an important assumption.  There are many places in the

  27070. ** code that do things like this:

  27071. **

  27072. **         int *a = (int*)sqlite3DbMallocRaw(db, 100);

  27073. **         int *b = (int*)sqlite3DbMallocRaw(db, 200);

  27074. **         if( b ) a[10] = 9;

  27075. **

  27076. ** In other words, if a subsequent malloc (ex: "b") worked, it is assumed

  27077. ** that all prior mallocs (ex: "a") worked too.

  27078. **

  27079. ** The sqlite3MallocRawNN() variant guarantees that the "db" parameter is

  27080. ** not a NULL pointer.

  27081. */

  27082. SQLITE_PRIVATE void *sqlite3DbMallocRaw(sqlite3 *db, u64 n){

  27083.   void *p;

  27084.   if( db ) return sqlite3DbMallocRawNN(db, n);

  27085.   p = sqlite3Malloc(n);

  27086.   sqlite3MemdebugSetType(p, MEMTYPE_HEAP);

  27087.   return p;

  27088. }

  27089. SQLITE_PRIVATE void *sqlite3DbMallocRawNN(sqlite3 *db, u64 n){

  27090. #ifndef SQLITE_OMIT_LOOKASIDE

  27091.   LookasideSlot *pBuf;

  27092.   assert( db!=0 );

  27093.   assert( sqlite3_mutex_held(db->mutex) );

  27094.   assert( db->pnBytesFreed==0 );

  27095.   if( db->lookaside.bDisable==0 ){

  27096.     assert( db->mallocFailed==0 );

  27097.     if( n>db->lookaside.sz ){

  27098.       db->lookaside.anStat[1]++;

  27099.     }else if( (pBuf = db->lookaside.pFree)!=0 ){

  27100.       db->lookaside.pFree = pBuf->pNext;

  27101.       db->lookaside.anStat[0]++;

  27102.       return (void*)pBuf;

  27103.     }else if( (pBuf = db->lookaside.pInit)!=0 ){

  27104.       db->lookaside.pInit = pBuf->pNext;

  27105.       db->lookaside.anStat[0]++;

  27106.       return (void*)pBuf;

  27107.     }else{

  27108.       db->lookaside.anStat[2]++;

  27109.     }

  27110.   }else if( db->mallocFailed ){

  27111.     return 0;

  27112.   }

  27113. #else

  27114.   assert( db!=0 );

  27115.   assert( sqlite3_mutex_held(db->mutex) );

  27116.   assert( db->pnBytesFreed==0 );

  27117.   if( db->mallocFailed ){

  27118.     return 0;

  27119.   }

  27120. #endif

  27121.   return dbMallocRawFinish(db, n);

  27122. }

  27123. 

  27124. /* Forward declaration */

  27125. static SQLITE_NOINLINE void *dbReallocFinish(sqlite3 *db, void *p, u64 n);

  27126. 

  27127. /*

  27128. ** Resize the block of memory pointed to by p to n bytes. If the

  27129. ** resize fails, set the mallocFailed flag in the connection object.

  27130. */

  27131. SQLITE_PRIVATE void *sqlite3DbRealloc(sqlite3 *db, void *p, u64 n){

  27132.   assert( db!=0 );

  27133.   if( p==0 ) return sqlite3DbMallocRawNN(db, n);

  27134.   assert( sqlite3_mutex_held(db->mutex) );

  27135.   if( isLookaside(db,p) && n<=db->lookaside.sz ) return p;

  27136.   return dbReallocFinish(db, p, n);

  27137. }

  27138. static SQLITE_NOINLINE void *dbReallocFinish(sqlite3 *db, void *p, u64 n){

  27139.   void *pNew = 0;

  27140.   assert( db!=0 );

  27141.   assert( p!=0 );

  27142.   if( db->mallocFailed==0 ){

  27143.     if( isLookaside(db, p) ){

  27144.       pNew = sqlite3DbMallocRawNN(db, n);

  27145.       if( pNew ){

  27146.         memcpy(pNew, p, db->lookaside.sz);

  27147.         sqlite3DbFree(db, p);

  27148.       }

  27149.     }else{

  27150.       assert( sqlite3MemdebugHasType(p, (MEMTYPE_LOOKASIDE|MEMTYPE_HEAP)) );

  27151.       assert( sqlite3MemdebugNoType(p, (u8)~(MEMTYPE_LOOKASIDE|MEMTYPE_HEAP)) );

  27152.       sqlite3MemdebugSetType(p, MEMTYPE_HEAP);

  27153.       pNew = sqlite3_realloc64(p, n);

  27154.       if( !pNew ){

  27155.         sqlite3OomFault(db);

  27156.       }

  27157.       sqlite3MemdebugSetType(pNew,

  27158.             (db->lookaside.bDisable==0 ? MEMTYPE_LOOKASIDE : MEMTYPE_HEAP));

  27159.     }

  27160.   }

  27161.   return pNew;

  27162. }

  27163. 

  27164. /*

  27165. ** Attempt to reallocate p.  If the reallocation fails, then free p

  27166. ** and set the mallocFailed flag in the database connection.

  27167. */

  27168. SQLITE_PRIVATE void *sqlite3DbReallocOrFree(sqlite3 *db, void *p, u64 n){

  27169.   void *pNew;

  27170.   pNew = sqlite3DbRealloc(db, p, n);

  27171.   if( !pNew ){

  27172.     sqlite3DbFree(db, p);

  27173.   }

  27174.   return pNew;

  27175. }

  27176. 

  27177. /*

  27178. ** Make a copy of a string in memory obtained from sqliteMalloc(). These 

  27179. ** functions call sqlite3MallocRaw() directly instead of sqliteMalloc(). This

  27180. ** is because when memory debugging is turned on, these two functions are 

  27181. ** called via macros that record the current file and line number in the

  27182. ** ThreadData structure.

  27183. */

  27184. SQLITE_PRIVATE char *sqlite3DbStrDup(sqlite3 *db, const char *z){

  27185.   char *zNew;

  27186.   size_t n;

  27187.   if( z==0 ){

  27188.     return 0;

  27189.   }

  27190.   n = strlen(z) + 1;

  27191.   zNew = sqlite3DbMallocRaw(db, n);

  27192.   if( zNew ){

  27193.     memcpy(zNew, z, n);

  27194.   }

  27195.   return zNew;

  27196. }

  27197. SQLITE_PRIVATE char *sqlite3DbStrNDup(sqlite3 *db, const char *z, u64 n){

  27198.   char *zNew;

  27199.   assert( db!=0 );

  27200.   if( z==0 ){

  27201.     return 0;

  27202.   }

  27203.   assert( (n&0x7fffffff)==n );

  27204.   zNew = sqlite3DbMallocRawNN(db, n+1);

  27205.   if( zNew ){

  27206.     memcpy(zNew, z, (size_t)n);

  27207.     zNew[n] = 0;

  27208.   }

  27209.   return zNew;

  27210. }

  27211. 

  27212. /*

  27213. ** The text between zStart and zEnd represents a phrase within a larger

  27214. ** SQL statement.  Make a copy of this phrase in space obtained form

  27215. ** sqlite3DbMalloc().  Omit leading and trailing whitespace.

  27216. */

  27217. SQLITE_PRIVATE char *sqlite3DbSpanDup(sqlite3 *db, const char *zStart, const char *zEnd){

  27218.   int n;

  27219.   while( sqlite3Isspace(zStart[0]) ) zStart++;

  27220.   n = (int)(zEnd - zStart);

  27221.   while( ALWAYS(n>0) && sqlite3Isspace(zStart[n-1]) ) n--;

  27222.   return sqlite3DbStrNDup(db, zStart, n);

  27223. }

  27224. 

  27225. /*

  27226. ** Free any prior content in *pz and replace it with a copy of zNew.

  27227. */

  27228. SQLITE_PRIVATE void sqlite3SetString(char **pz, sqlite3 *db, const char *zNew){

  27229.   sqlite3DbFree(db, *pz);

  27230.   *pz = sqlite3DbStrDup(db, zNew);

  27231. }

  27232. 

  27233. /*

  27234. ** Call this routine to record the fact that an OOM (out-of-memory) error

  27235. ** has happened.  This routine will set db->mallocFailed, and also

  27236. ** temporarily disable the lookaside memory allocator and interrupt

  27237. ** any running VDBEs.

  27238. */

  27239. SQLITE_PRIVATE void sqlite3OomFault(sqlite3 *db){

  27240.   if( db->mallocFailed==0 && db->bBenignMalloc==0 ){

  27241.     db->mallocFailed = 1;

  27242.     if( db->nVdbeExec>0 ){

  27243.       db->u1.isInterrupted = 1;

  27244.     }

  27245.     db->lookaside.bDisable++;

  27246.     if( db->pParse ){

  27247.       db->pParse->rc = SQLITE_NOMEM_BKPT;

  27248.     }

  27249.   }

  27250. }

  27251. 

  27252. /*

  27253. ** This routine reactivates the memory allocator and clears the

  27254. ** db->mallocFailed flag as necessary.

  27255. **

  27256. ** The memory allocator is not restarted if there are running

  27257. ** VDBEs.

  27258. */

  27259. SQLITE_PRIVATE void sqlite3OomClear(sqlite3 *db){

  27260.   if( db->mallocFailed && db->nVdbeExec==0 ){

  27261.     db->mallocFailed = 0;

  27262.     db->u1.isInterrupted = 0;

  27263.     assert( db->lookaside.bDisable>0 );

  27264.     db->lookaside.bDisable--;

  27265.   }

  27266. }

  27267. 

  27268. /*

  27269. ** Take actions at the end of an API call to indicate an OOM error

  27270. */

  27271. static SQLITE_NOINLINE int apiOomError(sqlite3 *db){

  27272.   sqlite3OomClear(db);

  27273.   sqlite3Error(db, SQLITE_NOMEM);

  27274.   return SQLITE_NOMEM_BKPT;

  27275. }

  27276. 

  27277. /*

  27278. ** This function must be called before exiting any API function (i.e. 

  27279. ** returning control to the user) that has called sqlite3_malloc or

  27280. ** sqlite3_realloc.

  27281. **

  27282. ** The returned value is normally a copy of the second argument to this

  27283. ** function. However, if a malloc() failure has occurred since the previous

  27284. ** invocation SQLITE_NOMEM is returned instead. 

  27285. **

  27286. ** If an OOM as occurred, then the connection error-code (the value

  27287. ** returned by sqlite3_errcode()) is set to SQLITE_NOMEM.

  27288. */

  27289. SQLITE_PRIVATE int sqlite3ApiExit(sqlite3* db, int rc){

  27290.   /* If the db handle must hold the connection handle mutex here.

  27291.   ** Otherwise the read (and possible write) of db->mallocFailed 

  27292.   ** is unsafe, as is the call to sqlite3Error().

  27293.   */

  27294.   assert( db!=0 );

  27295.   assert( sqlite3_mutex_held(db->mutex) );

  27296.   if( db->mallocFailed || rc==SQLITE_IOERR_NOMEM ){

  27297.     return apiOomError(db);

  27298.   }

  27299.   return rc & db->errMask;

  27300. }

  27301. 

  27302. /************** End of malloc.c **********************************************/

  27303. /************** Begin file printf.c ******************************************/

  27304. /*

  27305. ** The "printf" code that follows dates from the 1980's.  It is in

  27306. ** the public domain. 

  27307. **

  27308. **************************************************************************

  27309. **

  27310. ** This file contains code for a set of "printf"-like routines.  These

  27311. ** routines format strings much like the printf() from the standard C

  27312. ** library, though the implementation here has enhancements to support

  27313. ** SQLite.

  27314. */

  27315. /* #include "sqliteInt.h" */

  27316. 

  27317. /*

  27318. ** Conversion types fall into various categories as defined by the

  27319. ** following enumeration.

  27320. */

  27321. #define etRADIX       0 /* non-decimal integer types.  %x %o */

  27322. #define etFLOAT       1 /* Floating point.  %f */

  27323. #define etEXP         2 /* Exponentional notation. %e and %E */

  27324. #define etGENERIC     3 /* Floating or exponential, depending on exponent. %g */

  27325. #define etSIZE        4 /* Return number of characters processed so far. %n */

  27326. #define etSTRING      5 /* Strings. %s */

  27327. #define etDYNSTRING   6 /* Dynamically allocated strings. %z */

  27328. #define etPERCENT     7 /* Percent symbol. %% */

  27329. #define etCHARX       8 /* Characters. %c */

  27330. /* The rest are extensions, not normally found in printf() */

  27331. #define etSQLESCAPE   9 /* Strings with '\'' doubled.  %q */

  27332. #define etSQLESCAPE2 10 /* Strings with '\'' doubled and enclosed in '',

  27333.                           NULL pointers replaced by SQL NULL.  %Q */

  27334. #define etTOKEN      11 /* a pointer to a Token structure */

  27335. #define etSRCLIST    12 /* a pointer to a SrcList */

  27336. #define etPOINTER    13 /* The %p conversion */

  27337. #define etSQLESCAPE3 14 /* %w -> Strings with '\"' doubled */

  27338. #define etORDINAL    15 /* %r -> 1st, 2nd, 3rd, 4th, etc.  English only */

  27339. #define etDECIMAL    16 /* %d or %u, but not %x, %o */

  27340. 

  27341. #define etINVALID    17 /* Any unrecognized conversion type */

  27342. 

  27343. 

  27344. /*

  27345. ** An "etByte" is an 8-bit unsigned value.

  27346. */

  27347. typedef unsigned char etByte;

  27348. 

  27349. /*

  27350. ** Each builtin conversion character (ex: the 'd' in "%d") is described

  27351. ** by an instance of the following structure

  27352. */

  27353. typedef struct et_info {   /* Information about each format field */

  27354.   char fmttype;            /* The format field code letter */

  27355.   etByte base;             /* The base for radix conversion */

  27356.   etByte flags;            /* One or more of FLAG_ constants below */

  27357.   etByte type;             /* Conversion paradigm */

  27358.   etByte charset;          /* Offset into aDigits[] of the digits string */

  27359.   etByte prefix;           /* Offset into aPrefix[] of the prefix string */

  27360. } et_info;

  27361. 

  27362. /*

  27363. ** Allowed values for et_info.flags

  27364. */

  27365. #define FLAG_SIGNED    1     /* True if the value to convert is signed */

  27366. #define FLAG_STRING    4     /* Allow infinite precision */

  27367. 

  27368. 

  27369. /*

  27370. ** The following table is searched linearly, so it is good to put the

  27371. ** most frequently used conversion types first.

  27372. */

  27373. static const char aDigits[] = "0123456789ABCDEF0123456789abcdef";

  27374. static const char aPrefix[] = "-x0\000X0";

  27375. static const et_info fmtinfo[] = {

  27376.   {  'd', 10, 1, etDECIMAL,    0,  0 },

  27377.   {  's',  0, 4, etSTRING,     0,  0 },

  27378.   {  'g',  0, 1, etGENERIC,    30, 0 },

  27379.   {  'z',  0, 4, etDYNSTRING,  0,  0 },

  27380.   {  'q',  0, 4, etSQLESCAPE,  0,  0 },

  27381.   {  'Q',  0, 4, etSQLESCAPE2, 0,  0 },

  27382.   {  'w',  0, 4, etSQLESCAPE3, 0,  0 },

  27383.   {  'c',  0, 0, etCHARX,      0,  0 },

  27384.   {  'o',  8, 0, etRADIX,      0,  2 },

  27385.   {  'u', 10, 0, etDECIMAL,    0,  0 },

  27386.   {  'x', 16, 0, etRADIX,      16, 1 },

  27387.   {  'X', 16, 0, etRADIX,      0,  4 },

  27388. #ifndef SQLITE_OMIT_FLOATING_POINT

  27389.   {  'f',  0, 1, etFLOAT,      0,  0 },

  27390.   {  'e',  0, 1, etEXP,        30, 0 },

  27391.   {  'E',  0, 1, etEXP,        14, 0 },

  27392.   {  'G',  0, 1, etGENERIC,    14, 0 },

  27393. #endif

  27394.   {  'i', 10, 1, etDECIMAL,    0,  0 },

  27395.   {  'n',  0, 0, etSIZE,       0,  0 },

  27396.   {  '%',  0, 0, etPERCENT,    0,  0 },

  27397.   {  'p', 16, 0, etPOINTER,    0,  1 },

  27398. 

  27399.   /* All the rest are undocumented and are for internal use only */

  27400.   {  'T',  0, 0, etTOKEN,      0,  0 },

  27401.   {  'S',  0, 0, etSRCLIST,    0,  0 },

  27402.   {  'r', 10, 1, etORDINAL,    0,  0 },

  27403. };

  27404. 

  27405. /* Floating point constants used for rounding */

  27406. static const double arRound[] = {

  27407.   5.0e-01, 5.0e-02, 5.0e-03, 5.0e-04, 5.0e-05,

  27408.   5.0e-06, 5.0e-07, 5.0e-08, 5.0e-09, 5.0e-10,

  27409. };

  27410. 

  27411. /*

  27412. ** If SQLITE_OMIT_FLOATING_POINT is defined, then none of the floating point

  27413. ** conversions will work.

  27414. */

  27415. #ifndef SQLITE_OMIT_FLOATING_POINT

  27416. /*

  27417. ** "*val" is a double such that 0.1 <= *val < 10.0

  27418. ** Return the ascii code for the leading digit of *val, then

  27419. ** multiply "*val" by 10.0 to renormalize.

  27420. **

  27421. ** Example:

  27422. **     input:     *val = 3.14159

  27423. **     output:    *val = 1.4159    function return = '3'

  27424. **

  27425. ** The counter *cnt is incremented each time.  After counter exceeds

  27426. ** 16 (the number of significant digits in a 64-bit float) '0' is

  27427. ** always returned.

  27428. */

  27429. static char et_getdigit(LONGDOUBLE_TYPE *val, int *cnt){

  27430.   int digit;

  27431.   LONGDOUBLE_TYPE d;

  27432.   if( (*cnt)<=0 ) return '0';

  27433.   (*cnt)--;

  27434.   digit = (int)*val;

  27435.   d = digit;

  27436.   digit += '0';

  27437.   *val = (*val - d)*10.0;

  27438.   return (char)digit;

  27439. }

  27440. #endif /* SQLITE_OMIT_FLOATING_POINT */

  27441. 

  27442. /*

  27443. ** Set the StrAccum object to an error mode.

  27444. */

  27445. static void setStrAccumError(StrAccum *p, u8 eError){

  27446.   assert( eError==SQLITE_NOMEM || eError==SQLITE_TOOBIG );

  27447.   p->accError = eError;

  27448.   if( p->mxAlloc ) sqlite3_str_reset(p);

  27449.   if( eError==SQLITE_TOOBIG ) sqlite3ErrorToParser(p->db, eError);

  27450. }

  27451. 

  27452. /*

  27453. ** Extra argument values from a PrintfArguments object

  27454. */

  27455. static sqlite3_int64 getIntArg(PrintfArguments *p){

  27456.   if( p->nArg<=p->nUsed ) return 0;

  27457.   return sqlite3_value_int64(p->apArg[p->nUsed++]);

  27458. }

  27459. static double getDoubleArg(PrintfArguments *p){

  27460.   if( p->nArg<=p->nUsed ) return 0.0;

  27461.   return sqlite3_value_double(p->apArg[p->nUsed++]);

  27462. }

  27463. static char *getTextArg(PrintfArguments *p){

  27464.   if( p->nArg<=p->nUsed ) return 0;

  27465.   return (char*)sqlite3_value_text(p->apArg[p->nUsed++]);

  27466. }

  27467. 

  27468. /*

  27469. ** Allocate memory for a temporary buffer needed for printf rendering.

  27470. **

  27471. ** If the requested size of the temp buffer is larger than the size

  27472. ** of the output buffer in pAccum, then cause an SQLITE_TOOBIG error.

  27473. ** Do the size check before the memory allocation to prevent rogue

  27474. ** SQL from requesting large allocations using the precision or width

  27475. ** field of the printf() function.

  27476. */

  27477. static char *printfTempBuf(sqlite3_str *pAccum, sqlite3_int64 n){

  27478.   char *z;

  27479.   if( pAccum->accError ) return 0;

  27480.   if( n>pAccum->nAlloc && n>pAccum->mxAlloc ){

  27481.     setStrAccumError(pAccum, SQLITE_TOOBIG);

  27482.     return 0;

  27483.   }

  27484.   z = sqlite3DbMallocRaw(pAccum->db, n);

  27485.   if( z==0 ){

  27486.     setStrAccumError(pAccum, SQLITE_NOMEM);

  27487.   }

  27488.   return z;

  27489. }

  27490. 

  27491. /*

  27492. ** On machines with a small stack size, you can redefine the

  27493. ** SQLITE_PRINT_BUF_SIZE to be something smaller, if desired.

  27494. */

  27495. #ifndef SQLITE_PRINT_BUF_SIZE

  27496. # define SQLITE_PRINT_BUF_SIZE 70

  27497. #endif

  27498. #define etBUFSIZE SQLITE_PRINT_BUF_SIZE  /* Size of the output buffer */

  27499. 

  27500. /*

  27501. ** Render a string given by "fmt" into the StrAccum object.

  27502. */

  27503. SQLITE_API void sqlite3_str_vappendf(

  27504.   sqlite3_str *pAccum,       /* Accumulate results here */

  27505.   const char *fmt,           /* Format string */

  27506.   va_list ap                 /* arguments */

  27507. ){

  27508.   int c;                     /* Next character in the format string */

  27509.   char *bufpt;               /* Pointer to the conversion buffer */

  27510.   int precision;             /* Precision of the current field */

  27511.   int length;                /* Length of the field */

  27512.   int idx;                   /* A general purpose loop counter */

  27513.   int width;                 /* Width of the current field */

  27514.   etByte flag_leftjustify;   /* True if "-" flag is present */

  27515.   etByte flag_prefix;        /* '+' or ' ' or 0 for prefix */

  27516.   etByte flag_alternateform; /* True if "#" flag is present */

  27517.   etByte flag_altform2;      /* True if "!" flag is present */

  27518.   etByte flag_zeropad;       /* True if field width constant starts with zero */

  27519.   etByte flag_long;          /* 1 for the "l" flag, 2 for "ll", 0 by default */

  27520.   etByte done;               /* Loop termination flag */

  27521.   etByte cThousand;          /* Thousands separator for %d and %u */

  27522.   etByte xtype = etINVALID;  /* Conversion paradigm */

  27523.   u8 bArgList;               /* True for SQLITE_PRINTF_SQLFUNC */

  27524.   char prefix;               /* Prefix character.  "+" or "-" or " " or '\0'. */

  27525.   sqlite_uint64 longvalue;   /* Value for integer types */

  27526.   LONGDOUBLE_TYPE realvalue; /* Value for real types */

  27527.   const et_info *infop;      /* Pointer to the appropriate info structure */

  27528.   char *zOut;                /* Rendering buffer */

  27529.   int nOut;                  /* Size of the rendering buffer */

  27530.   char *zExtra = 0;          /* Malloced memory used by some conversion */

  27531. #ifndef SQLITE_OMIT_FLOATING_POINT

  27532.   int  exp, e2;              /* exponent of real numbers */

  27533.   int nsd;                   /* Number of significant digits returned */

  27534.   double rounder;            /* Used for rounding floating point values */

  27535.   etByte flag_dp;            /* True if decimal point should be shown */

  27536.   etByte flag_rtz;           /* True if trailing zeros should be removed */

  27537. #endif

  27538.   PrintfArguments *pArgList = 0; /* Arguments for SQLITE_PRINTF_SQLFUNC */

  27539.   char buf[etBUFSIZE];       /* Conversion buffer */

  27540. 

  27541.   /* pAccum never starts out with an empty buffer that was obtained from 

  27542.   ** malloc().  This precondition is required by the mprintf("%z...")

  27543.   ** optimization. */

  27544.   assert( pAccum->nChar>0 || (pAccum->printfFlags&SQLITE_PRINTF_MALLOCED)==0 );

  27545. 

  27546.   bufpt = 0;

  27547.   if( (pAccum->printfFlags & SQLITE_PRINTF_SQLFUNC)!=0 ){

  27548.     pArgList = va_arg(ap, PrintfArguments*);

  27549.     bArgList = 1;

  27550.   }else{

  27551.     bArgList = 0;

  27552.   }

  27553.   for(; (c=(*fmt))!=0; ++fmt){

  27554.     if( c!='%' ){

  27555.       bufpt = (char *)fmt;

  27556. #if HAVE_STRCHRNUL

  27557.       fmt = strchrnul(fmt, '%');

  27558. #else

  27559.       do{ fmt++; }while( *fmt && *fmt != '%' );

  27560. #endif

  27561.       sqlite3_str_append(pAccum, bufpt, (int)(fmt - bufpt));

  27562.       if( *fmt==0 ) break;

  27563.     }

  27564.     if( (c=(*++fmt))==0 ){

  27565.       sqlite3_str_append(pAccum, "%", 1);

  27566.       break;

  27567.     }

  27568.     /* Find out what flags are present */

  27569.     flag_leftjustify = flag_prefix = cThousand =

  27570.      flag_alternateform = flag_altform2 = flag_zeropad = 0;

  27571.     done = 0;

  27572.     width = 0;

  27573.     flag_long = 0;

  27574.     precision = -1;

  27575.     do{

  27576.       switch( c ){

  27577.         case '-':   flag_leftjustify = 1;     break;

  27578.         case '+':   flag_prefix = '+';        break;

  27579.         case ' ':   flag_prefix = ' ';        break;

  27580.         case '#':   flag_alternateform = 1;   break;

  27581.         case '!':   flag_altform2 = 1;        break;

  27582.         case '0':   flag_zeropad = 1;         break;

  27583.         case ',':   cThousand = ',';          break;

  27584.         default:    done = 1;                 break;

  27585.         case 'l': {

  27586.           flag_long = 1;

  27587.           c = *++fmt;

  27588.           if( c=='l' ){

  27589.             c = *++fmt;

  27590.             flag_long = 2;

  27591.           }

  27592.           done = 1;

  27593.           break;

  27594.         }

  27595.         case '1': case '2': case '3': case '4': case '5':

  27596.         case '6': case '7': case '8': case '9': {

  27597.           unsigned wx = c - '0';

  27598.           while( (c = *++fmt)>='0' && c<='9' ){

  27599.             wx = wx*10 + c - '0';

  27600.           }

  27601.           testcase( wx>0x7fffffff );

  27602.           width = wx & 0x7fffffff;

  27603. #ifdef SQLITE_PRINTF_PRECISION_LIMIT

  27604.           if( width>SQLITE_PRINTF_PRECISION_LIMIT ){

  27605.             width = SQLITE_PRINTF_PRECISION_LIMIT;

  27606.           }

  27607. #endif

  27608.           if( c!='.' && c!='l' ){

  27609.             done = 1;

  27610.           }else{

  27611.             fmt--;

  27612.           }

  27613.           break;

  27614.         }

  27615.         case '*': {

  27616.           if( bArgList ){

  27617.             width = (int)getIntArg(pArgList);

  27618.           }else{

  27619.             width = va_arg(ap,int);

  27620.           }

  27621.           if( width<0 ){

  27622.             flag_leftjustify = 1;

  27623.             width = width >= -2147483647 ? -width : 0;

  27624.           }

  27625. #ifdef SQLITE_PRINTF_PRECISION_LIMIT

  27626.           if( width>SQLITE_PRINTF_PRECISION_LIMIT ){

  27627.             width = SQLITE_PRINTF_PRECISION_LIMIT;

  27628.           }

  27629. #endif

  27630.           if( (c = fmt[1])!='.' && c!='l' ){

  27631.             c = *++fmt;

  27632.             done = 1;

  27633.           }

  27634.           break;

  27635.         }

  27636.         case '.': {

  27637.           c = *++fmt;

  27638.           if( c=='*' ){

  27639.             if( bArgList ){

  27640.               precision = (int)getIntArg(pArgList);

  27641.             }else{

  27642.               precision = va_arg(ap,int);

  27643.             }

  27644.             if( precision<0 ){

  27645.               precision = precision >= -2147483647 ? -precision : -1;

  27646.             }

  27647.             c = *++fmt;

  27648.           }else{

  27649.             unsigned px = 0;

  27650.             while( c>='0' && c<='9' ){

  27651.               px = px*10 + c - '0';

  27652.               c = *++fmt;

  27653.             }

  27654.             testcase( px>0x7fffffff );

  27655.             precision = px & 0x7fffffff;

  27656.           }

  27657. #ifdef SQLITE_PRINTF_PRECISION_LIMIT

  27658.           if( precision>SQLITE_PRINTF_PRECISION_LIMIT ){

  27659.             precision = SQLITE_PRINTF_PRECISION_LIMIT;

  27660.           }

  27661. #endif

  27662.           if( c=='l' ){

  27663.             --fmt;

  27664.           }else{

  27665.             done = 1;

  27666.           }

  27667.           break;

  27668.         }

  27669.       }

  27670.     }while( !done && (c=(*++fmt))!=0 );

  27671. 

  27672.     /* Fetch the info entry for the field */

  27673.     infop = &fmtinfo[0];

  27674.     xtype = etINVALID;

  27675.     for(idx=0; idx<ArraySize(fmtinfo); idx++){

  27676.       if( c==fmtinfo[idx].fmttype ){

  27677.         infop = &fmtinfo[idx];

  27678.         xtype = infop->type;

  27679.         break;

  27680.       }

  27681.     }

  27682. 

  27683.     /*

  27684.     ** At this point, variables are initialized as follows:

  27685.     **

  27686.     **   flag_alternateform          TRUE if a '#' is present.

  27687.     **   flag_altform2               TRUE if a '!' is present.

  27688.     **   flag_prefix                 '+' or ' ' or zero

  27689.     **   flag_leftjustify            TRUE if a '-' is present or if the

  27690.     **                               field width was negative.

  27691.     **   flag_zeropad                TRUE if the width began with 0.

  27692.     **   flag_long                   1 for "l", 2 for "ll"

  27693.     **   width                       The specified field width.  This is

  27694.     **                               always non-negative.  Zero is the default.

  27695.     **   precision                   The specified precision.  The default

  27696.     **                               is -1.

  27697.     **   xtype                       The class of the conversion.

  27698.     **   infop                       Pointer to the appropriate info struct.

  27699.     */

  27700.     switch( xtype ){

  27701.       case etPOINTER:

  27702.         flag_long = sizeof(char*)==sizeof(i64) ? 2 :

  27703.                      sizeof(char*)==sizeof(long int) ? 1 : 0;

  27704.         /* Fall through into the next case */

  27705.       case etORDINAL:

  27706.       case etRADIX:      

  27707.         cThousand = 0;

  27708.         /* Fall through into the next case */

  27709.       case etDECIMAL:

  27710.         if( infop->flags & FLAG_SIGNED ){

  27711.           i64 v;

  27712.           if( bArgList ){

  27713.             v = getIntArg(pArgList);

  27714.           }else if( flag_long ){

  27715.             if( flag_long==2 ){

  27716.               v = va_arg(ap,i64) ;

  27717.             }else{

  27718.               v = va_arg(ap,long int);

  27719.             }

  27720.           }else{

  27721.             v = va_arg(ap,int);

  27722.           }

  27723.           if( v<0 ){

  27724.             if( v==SMALLEST_INT64 ){

  27725.               longvalue = ((u64)1)<<63;

  27726.             }else{

  27727.               longvalue = -v;

  27728.             }

  27729.             prefix = '-';

  27730.           }else{

  27731.             longvalue = v;

  27732.             prefix = flag_prefix;

  27733.           }

  27734.         }else{

  27735.           if( bArgList ){

  27736.             longvalue = (u64)getIntArg(pArgList);

  27737.           }else if( flag_long ){

  27738.             if( flag_long==2 ){

  27739.               longvalue = va_arg(ap,u64);

  27740.             }else{

  27741.               longvalue = va_arg(ap,unsigned long int);

  27742.             }

  27743.           }else{

  27744.             longvalue = va_arg(ap,unsigned int);

  27745.           }

  27746.           prefix = 0;

  27747.         }

  27748.         if( longvalue==0 ) flag_alternateform = 0;

  27749.         if( flag_zeropad && precision<width-(prefix!=0) ){

  27750.           precision = width-(prefix!=0);

  27751.         }

  27752.         if( precision<etBUFSIZE-10-etBUFSIZE/3 ){

  27753.           nOut = etBUFSIZE;

  27754.           zOut = buf;

  27755.         }else{

  27756.           u64 n;

  27757.           n = (u64)precision + 10;

  27758.           if( cThousand ) n += precision/3;

  27759.           zOut = zExtra = printfTempBuf(pAccum, n);

  27760.           if( zOut==0 ) return;

  27761.           nOut = (int)n;

  27762.         }

  27763.         bufpt = &zOut[nOut-1];

  27764.         if( xtype==etORDINAL ){

  27765.           static const char zOrd[] = "thstndrd";

  27766.           int x = (int)(longvalue % 10);

  27767.           if( x>=4 || (longvalue/10)%10==1 ){

  27768.             x = 0;

  27769.           }

  27770.           *(--bufpt) = zOrd[x*2+1];

  27771.           *(--bufpt) = zOrd[x*2];

  27772.         }

  27773.         {

  27774.           const char *cset = &aDigits[infop->charset];

  27775.           u8 base = infop->base;

  27776.           do{                                           /* Convert to ascii */

  27777.             *(--bufpt) = cset[longvalue%base];

  27778.             longvalue = longvalue/base;

  27779.           }while( longvalue>0 );

  27780.         }

  27781.         length = (int)(&zOut[nOut-1]-bufpt);

  27782.         while( precision>length ){

  27783.           *(--bufpt) = '0';                             /* Zero pad */

  27784.           length++;

  27785.         }

  27786.         if( cThousand ){

  27787.           int nn = (length - 1)/3;  /* Number of "," to insert */

  27788.           int ix = (length - 1)%3 + 1;

  27789.           bufpt -= nn;

  27790.           for(idx=0; nn>0; idx++){

  27791.             bufpt[idx] = bufpt[idx+nn];

  27792.             ix--;

  27793.             if( ix==0 ){

  27794.               bufpt[++idx] = cThousand;

  27795.               nn--;

  27796.               ix = 3;

  27797.             }

  27798.           }

  27799.         }

  27800.         if( prefix ) *(--bufpt) = prefix;               /* Add sign */

  27801.         if( flag_alternateform && infop->prefix ){      /* Add "0" or "0x" */

  27802.           const char *pre;

  27803.           char x;

  27804.           pre = &aPrefix[infop->prefix];

  27805.           for(; (x=(*pre))!=0; pre++) *(--bufpt) = x;

  27806.         }

  27807.         length = (int)(&zOut[nOut-1]-bufpt);

  27808.         break;

  27809.       case etFLOAT:

  27810.       case etEXP:

  27811.       case etGENERIC:

  27812.         if( bArgList ){

  27813.           realvalue = getDoubleArg(pArgList);

  27814.         }else{

  27815.           realvalue = va_arg(ap,double);

  27816.         }

  27817. #ifdef SQLITE_OMIT_FLOATING_POINT

  27818.         length = 0;

  27819. #else

  27820.         if( precision<0 ) precision = 6;         /* Set default precision */

  27821.         if( realvalue<0.0 ){

  27822.           realvalue = -realvalue;

  27823.           prefix = '-';

  27824.         }else{

  27825.           prefix = flag_prefix;

  27826.         }

  27827.         if( xtype==etGENERIC && precision>0 ) precision--;

  27828.         testcase( precision>0xfff );

  27829.         idx = precision & 0xfff;

  27830.         rounder = arRound[idx%10];

  27831.         while( idx>=10 ){ rounder *= 1.0e-10; idx -= 10; }

  27832.         if( xtype==etFLOAT ){

  27833.           double rx = (double)realvalue;

  27834.           sqlite3_uint64 u;

  27835.           int ex;

  27836.           memcpy(&u, &rx, sizeof(u));

  27837.           ex = -1023 + (int)((u>>52)&0x7ff);

  27838.           if( precision+(ex/3) < 15 ) rounder += realvalue*3e-16;

  27839.           realvalue += rounder;

  27840.         }

  27841.         /* Normalize realvalue to within 10.0 > realvalue >= 1.0 */

  27842.         exp = 0;

  27843.         if( sqlite3IsNaN((double)realvalue) ){

  27844.           bufpt = "NaN";

  27845.           length = 3;

  27846.           break;

  27847.         }

  27848.         if( realvalue>0.0 ){

  27849.           LONGDOUBLE_TYPE scale = 1.0;

  27850.           while( realvalue>=1e100*scale && exp<=350 ){ scale *= 1e100;exp+=100;}

  27851.           while( realvalue>=1e10*scale && exp<=350 ){ scale *= 1e10; exp+=10; }

  27852.           while( realvalue>=10.0*scale && exp<=350 ){ scale *= 10.0; exp++; }

  27853.           realvalue /= scale;

  27854.           while( realvalue<1e-8 ){ realvalue *= 1e8; exp-=8; }

  27855.           while( realvalue<1.0 ){ realvalue *= 10.0; exp--; }

  27856.           if( exp>350 ){

  27857.             bufpt = buf;

  27858.             buf[0] = prefix;

  27859.             memcpy(buf+(prefix!=0),"Inf",4);

  27860.             length = 3+(prefix!=0);

  27861.             break;

  27862.           }

  27863.         }

  27864.         bufpt = buf;

  27865.         /*

  27866.         ** If the field type is etGENERIC, then convert to either etEXP

  27867.         ** or etFLOAT, as appropriate.

  27868.         */

  27869.         if( xtype!=etFLOAT ){

  27870.           realvalue += rounder;

  27871.           if( realvalue>=10.0 ){ realvalue *= 0.1; exp++; }

  27872.         }

  27873.         if( xtype==etGENERIC ){

  27874.           flag_rtz = !flag_alternateform;

  27875.           if( exp<-4 || exp>precision ){

  27876.             xtype = etEXP;

  27877.           }else{

  27878.             precision = precision - exp;

  27879.             xtype = etFLOAT;

  27880.           }

  27881.         }else{

  27882.           flag_rtz = flag_altform2;

  27883.         }

  27884.         if( xtype==etEXP ){

  27885.           e2 = 0;

  27886.         }else{

  27887.           e2 = exp;

  27888.         }

  27889.         {

  27890.           i64 szBufNeeded;           /* Size of a temporary buffer needed */

  27891.           szBufNeeded = MAX(e2,0)+(i64)precision+(i64)width+15;

  27892.           if( szBufNeeded > etBUFSIZE ){

  27893.             bufpt = zExtra = printfTempBuf(pAccum, szBufNeeded);

  27894.             if( bufpt==0 ) return;

  27895.           }

  27896.         }

  27897.         zOut = bufpt;

  27898.         nsd = 16 + flag_altform2*10;

  27899.         flag_dp = (precision>0 ?1:0) | flag_alternateform | flag_altform2;

  27900.         /* The sign in front of the number */

  27901.         if( prefix ){

  27902.           *(bufpt++) = prefix;

  27903.         }

  27904.         /* Digits prior to the decimal point */

  27905.         if( e2<0 ){

  27906.           *(bufpt++) = '0';

  27907.         }else{

  27908.           for(; e2>=0; e2--){

  27909.             *(bufpt++) = et_getdigit(&realvalue,&nsd);

  27910.           }

  27911.         }

  27912.         /* The decimal point */

  27913.         if( flag_dp ){

  27914.           *(bufpt++) = '.';

  27915.         }

  27916.         /* "0" digits after the decimal point but before the first

  27917.         ** significant digit of the number */

  27918.         for(e2++; e2<0; precision--, e2++){

  27919.           assert( precision>0 );

  27920.           *(bufpt++) = '0';

  27921.         }

  27922.         /* Significant digits after the decimal point */

  27923.         while( (precision--)>0 ){

  27924.           *(bufpt++) = et_getdigit(&realvalue,&nsd);

  27925.         }

  27926.         /* Remove trailing zeros and the "." if no digits follow the "." */

  27927.         if( flag_rtz && flag_dp ){

  27928.           while( bufpt[-1]=='0' ) *(--bufpt) = 0;

  27929.           assert( bufpt>zOut );

  27930.           if( bufpt[-1]=='.' ){

  27931.             if( flag_altform2 ){

  27932.               *(bufpt++) = '0';

  27933.             }else{

  27934.               *(--bufpt) = 0;

  27935.             }

  27936.           }

  27937.         }

  27938.         /* Add the "eNNN" suffix */

  27939.         if( xtype==etEXP ){

  27940.           *(bufpt++) = aDigits[infop->charset];

  27941.           if( exp<0 ){

  27942.             *(bufpt++) = '-'; exp = -exp;

  27943.           }else{

  27944.             *(bufpt++) = '+';

  27945.           }

  27946.           if( exp>=100 ){

  27947.             *(bufpt++) = (char)((exp/100)+'0');        /* 100's digit */

  27948.             exp %= 100;

  27949.           }

  27950.           *(bufpt++) = (char)(exp/10+'0');             /* 10's digit */

  27951.           *(bufpt++) = (char)(exp%10+'0');             /* 1's digit */

  27952.         }

  27953.         *bufpt = 0;

  27954. 

  27955.         /* The converted number is in buf[] and zero terminated. Output it.

  27956.         ** Note that the number is in the usual order, not reversed as with

  27957.         ** integer conversions. */

  27958.         length = (int)(bufpt-zOut);

  27959.         bufpt = zOut;

  27960. 

  27961.         /* Special case:  Add leading zeros if the flag_zeropad flag is

  27962.         ** set and we are not left justified */

  27963.         if( flag_zeropad && !flag_leftjustify && length < width){

  27964.           int i;

  27965.           int nPad = width - length;

  27966.           for(i=width; i>=nPad; i--){

  27967.             bufpt[i] = bufpt[i-nPad];

  27968.           }

  27969.           i = prefix!=0;

  27970.           while( nPad-- ) bufpt[i++] = '0';

  27971.           length = width;

  27972.         }

  27973. #endif /* !defined(SQLITE_OMIT_FLOATING_POINT) */

  27974.         break;

  27975.       case etSIZE:

  27976.         if( !bArgList ){

  27977.           *(va_arg(ap,int*)) = pAccum->nChar;

  27978.         }

  27979.         length = width = 0;

  27980.         break;

  27981.       case etPERCENT:

  27982.         buf[0] = '%';

  27983.         bufpt = buf;

  27984.         length = 1;

  27985.         break;

  27986.       case etCHARX:

  27987.         if( bArgList ){

  27988.           bufpt = getTextArg(pArgList);

  27989.           length = 1;

  27990.           if( bufpt ){

  27991.             buf[0] = c = *(bufpt++);

  27992.             if( (c&0xc0)==0xc0 ){

  27993.               while( length<4 && (bufpt[0]&0xc0)==0x80 ){

  27994.                 buf[length++] = *(bufpt++);

  27995.               }

  27996.             }

  27997.           }else{

  27998.             buf[0] = 0;

  27999.           }

  28000.         }else{

  28001.           unsigned int ch = va_arg(ap,unsigned int);

  28002.           if( ch<0x00080 ){

  28003.             buf[0] = ch & 0xff;

  28004.             length = 1;

  28005.           }else if( ch<0x00800 ){

  28006.             buf[0] = 0xc0 + (u8)((ch>>6)&0x1f);

  28007.             buf[1] = 0x80 + (u8)(ch & 0x3f);

  28008.             length = 2;

  28009.           }else if( ch<0x10000 ){

  28010.             buf[0] = 0xe0 + (u8)((ch>>12)&0x0f);

  28011.             buf[1] = 0x80 + (u8)((ch>>6) & 0x3f);

  28012.             buf[2] = 0x80 + (u8)(ch & 0x3f);

  28013.             length = 3;

  28014.           }else{

  28015.             buf[0] = 0xf0 + (u8)((ch>>18) & 0x07);

  28016.             buf[1] = 0x80 + (u8)((ch>>12) & 0x3f);

  28017.             buf[2] = 0x80 + (u8)((ch>>6) & 0x3f);

  28018.             buf[3] = 0x80 + (u8)(ch & 0x3f);

  28019.             length = 4;

  28020.           }

  28021.         }

  28022.         if( precision>1 ){

  28023.           width -= precision-1;

  28024.           if( width>1 && !flag_leftjustify ){

  28025.             sqlite3_str_appendchar(pAccum, width-1, ' ');

  28026.             width = 0;

  28027.           }

  28028.           while( precision-- > 1 ){

  28029.             sqlite3_str_append(pAccum, buf, length);

  28030.           }

  28031.         }

  28032.         bufpt = buf;

  28033.         flag_altform2 = 1;

  28034.         goto adjust_width_for_utf8;

  28035.       case etSTRING:

  28036.       case etDYNSTRING:

  28037.         if( bArgList ){

  28038.           bufpt = getTextArg(pArgList);

  28039.           xtype = etSTRING;

  28040.         }else{

  28041.           bufpt = va_arg(ap,char*);

  28042.         }

  28043.         if( bufpt==0 ){

  28044.           bufpt = "";

  28045.         }else if( xtype==etDYNSTRING ){

  28046.           if( pAccum->nChar==0

  28047.            && pAccum->mxAlloc

  28048.            && width==0

  28049.            && precision<0

  28050.            && pAccum->accError==0

  28051.           ){

  28052.             /* Special optimization for sqlite3_mprintf("%z..."):

  28053.             ** Extend an existing memory allocation rather than creating

  28054.             ** a new one. */

  28055.             assert( (pAccum->printfFlags&SQLITE_PRINTF_MALLOCED)==0 );

  28056.             pAccum->zText = bufpt;

  28057.             pAccum->nAlloc = sqlite3DbMallocSize(pAccum->db, bufpt);

  28058.             pAccum->nChar = 0x7fffffff & (int)strlen(bufpt);

  28059.             pAccum->printfFlags |= SQLITE_PRINTF_MALLOCED;

  28060.             length = 0;

  28061.             break;

  28062.           }

  28063.           zExtra = bufpt;

  28064.         }

  28065.         if( precision>=0 ){

  28066.           if( flag_altform2 ){

  28067.             /* Set length to the number of bytes needed in order to display

  28068.             ** precision characters */

  28069.             unsigned char *z = (unsigned char*)bufpt;

  28070.             while( precision-- > 0 && z[0] ){

  28071.               SQLITE_SKIP_UTF8(z);

  28072.             }

  28073.             length = (int)(z - (unsigned char*)bufpt);

  28074.           }else{

  28075.             for(length=0; length<precision && bufpt[length]; length++){}

  28076.           }

  28077.         }else{

  28078.           length = 0x7fffffff & (int)strlen(bufpt);

  28079.         }

  28080.       adjust_width_for_utf8:

  28081.         if( flag_altform2 && width>0 ){

  28082.           /* Adjust width to account for extra bytes in UTF-8 characters */

  28083.           int ii = length - 1;

  28084.           while( ii>=0 ) if( (bufpt[ii--] & 0xc0)==0x80 ) width++;

  28085.         }

  28086.         break;

  28087.       case etSQLESCAPE:           /* %q: Escape ' characters */

  28088.       case etSQLESCAPE2:          /* %Q: Escape ' and enclose in '...' */

  28089.       case etSQLESCAPE3: {        /* %w: Escape " characters */

  28090.         int i, j, k, n, isnull;

  28091.         int needQuote;

  28092.         char ch;

  28093.         char q = ((xtype==etSQLESCAPE3)?'"':'\'');   /* Quote character */

  28094.         char *escarg;

  28095. 

  28096.         if( bArgList ){

  28097.           escarg = getTextArg(pArgList);

  28098.         }else{

  28099.           escarg = va_arg(ap,char*);

  28100.         }

  28101.         isnull = escarg==0;

  28102.         if( isnull ) escarg = (xtype==etSQLESCAPE2 ? "NULL" : "(NULL)");

  28103.         /* For %q, %Q, and %w, the precision is the number of byte (or

  28104.         ** characters if the ! flags is present) to use from the input.

  28105.         ** Because of the extra quoting characters inserted, the number

  28106.         ** of output characters may be larger than the precision.

  28107.         */

  28108.         k = precision;

  28109.         for(i=n=0; k!=0 && (ch=escarg[i])!=0; i++, k--){

  28110.           if( ch==q )  n++;

  28111.           if( flag_altform2 && (ch&0xc0)==0xc0 ){

  28112.             while( (escarg[i+1]&0xc0)==0x80 ){ i++; }

  28113.           }

  28114.         }

  28115.         needQuote = !isnull && xtype==etSQLESCAPE2;

  28116.         n += i + 3;

  28117.         if( n>etBUFSIZE ){

  28118.           bufpt = zExtra = printfTempBuf(pAccum, n);

  28119.           if( bufpt==0 ) return;

  28120.         }else{

  28121.           bufpt = buf;

  28122.         }

  28123.         j = 0;

  28124.         if( needQuote ) bufpt[j++] = q;

  28125.         k = i;

  28126.         for(i=0; i<k; i++){

  28127.           bufpt[j++] = ch = escarg[i];

  28128.           if( ch==q ) bufpt[j++] = ch;

  28129.         }

  28130.         if( needQuote ) bufpt[j++] = q;

  28131.         bufpt[j] = 0;

  28132.         length = j;

  28133.         goto adjust_width_for_utf8;

  28134.       }

  28135.       case etTOKEN: {

  28136.         Token *pToken;

  28137.         if( (pAccum->printfFlags & SQLITE_PRINTF_INTERNAL)==0 ) return;

  28138.         pToken = va_arg(ap, Token*);

  28139.         assert( bArgList==0 );

  28140.         if( pToken && pToken->n ){

  28141.           sqlite3_str_append(pAccum, (const char*)pToken->z, pToken->n);

  28142.         }

  28143.         length = width = 0;

  28144.         break;

  28145.       }

  28146.       case etSRCLIST: {

  28147.         SrcList *pSrc;

  28148.         int k;

  28149.         struct SrcList_item *pItem;

  28150.         if( (pAccum->printfFlags & SQLITE_PRINTF_INTERNAL)==0 ) return;

  28151.         pSrc = va_arg(ap, SrcList*);

  28152.         k = va_arg(ap, int);

  28153.         pItem = &pSrc->a[k];

  28154.         assert( bArgList==0 );

  28155.         assert( k>=0 && k<pSrc->nSrc );

  28156.         if( pItem->zDatabase ){

  28157.           sqlite3_str_appendall(pAccum, pItem->zDatabase);

  28158.           sqlite3_str_append(pAccum, ".", 1);

  28159.         }

  28160.         sqlite3_str_appendall(pAccum, pItem->zName);

  28161.         length = width = 0;

  28162.         break;

  28163.       }

  28164.       default: {

  28165.         assert( xtype==etINVALID );

  28166.         return;

  28167.       }

  28168.     }/* End switch over the format type */

  28169.     /*

  28170.     ** The text of the conversion is pointed to by "bufpt" and is

  28171.     ** "length" characters long.  The field width is "width".  Do

  28172.     ** the output.  Both length and width are in bytes, not characters,

  28173.     ** at this point.  If the "!" flag was present on string conversions

  28174.     ** indicating that width and precision should be expressed in characters,

  28175.     ** then the values have been translated prior to reaching this point.

  28176.     */

  28177.     width -= length;

  28178.     if( width>0 ){

  28179.       if( !flag_leftjustify ) sqlite3_str_appendchar(pAccum, width, ' ');

  28180.       sqlite3_str_append(pAccum, bufpt, length);

  28181.       if( flag_leftjustify ) sqlite3_str_appendchar(pAccum, width, ' ');

  28182.     }else{

  28183.       sqlite3_str_append(pAccum, bufpt, length);

  28184.     }

  28185. 

  28186.     if( zExtra ){

  28187.       sqlite3DbFree(pAccum->db, zExtra);

  28188.       zExtra = 0;

  28189.     }

  28190.   }/* End for loop over the format string */

  28191. } /* End of function */

  28192. 

  28193. /*

  28194. ** Enlarge the memory allocation on a StrAccum object so that it is

  28195. ** able to accept at least N more bytes of text.

  28196. **

  28197. ** Return the number of bytes of text that StrAccum is able to accept

  28198. ** after the attempted enlargement.  The value returned might be zero.

  28199. */

  28200. static int sqlite3StrAccumEnlarge(StrAccum *p, int N){

  28201.   char *zNew;

  28202.   assert( p->nChar+(i64)N >= p->nAlloc ); /* Only called if really needed */

  28203.   if( p->accError ){

  28204.     testcase(p->accError==SQLITE_TOOBIG);

  28205.     testcase(p->accError==SQLITE_NOMEM);

  28206.     return 0;

  28207.   }

  28208.   if( p->mxAlloc==0 ){

  28209.     setStrAccumError(p, SQLITE_TOOBIG);

  28210.     return p->nAlloc - p->nChar - 1;

  28211.   }else{

  28212.     char *zOld = isMalloced(p) ? p->zText : 0;

  28213.     i64 szNew = p->nChar;

  28214.     szNew += N + 1;

  28215.     if( szNew+p->nChar<=p->mxAlloc ){

  28216.       /* Force exponential buffer size growth as long as it does not overflow,

  28217.       ** to avoid having to call this routine too often */

  28218.       szNew += p->nChar;

  28219.     }

  28220.     if( szNew > p->mxAlloc ){

  28221.       sqlite3_str_reset(p);

  28222.       setStrAccumError(p, SQLITE_TOOBIG);

  28223.       return 0;

  28224.     }else{

  28225.       p->nAlloc = (int)szNew;

  28226.     }

  28227.     if( p->db ){

  28228.       zNew = sqlite3DbRealloc(p->db, zOld, p->nAlloc);

  28229.     }else{

  28230.       zNew = sqlite3_realloc64(zOld, p->nAlloc);

  28231.     }

  28232.     if( zNew ){

  28233.       assert( p->zText!=0 || p->nChar==0 );

  28234.       if( !isMalloced(p) && p->nChar>0 ) memcpy(zNew, p->zText, p->nChar);

  28235.       p->zText = zNew;

  28236.       p->nAlloc = sqlite3DbMallocSize(p->db, zNew);

  28237.       p->printfFlags |= SQLITE_PRINTF_MALLOCED;

  28238.     }else{

  28239.       sqlite3_str_reset(p);

  28240.       setStrAccumError(p, SQLITE_NOMEM);

  28241.       return 0;

  28242.     }

  28243.   }

  28244.   return N;

  28245. }

  28246. 

  28247. /*

  28248. ** Append N copies of character c to the given string buffer.

  28249. */

  28250. SQLITE_API void sqlite3_str_appendchar(sqlite3_str *p, int N, char c){

  28251.   testcase( p->nChar + (i64)N > 0x7fffffff );

  28252.   if( p->nChar+(i64)N >= p->nAlloc && (N = sqlite3StrAccumEnlarge(p, N))<=0 ){

  28253.     return;

  28254.   }

  28255.   while( (N--)>0 ) p->zText[p->nChar++] = c;

  28256. }

  28257. 

  28258. /*

  28259. ** The StrAccum "p" is not large enough to accept N new bytes of z[].

  28260. ** So enlarge if first, then do the append.

  28261. **

  28262. ** This is a helper routine to sqlite3_str_append() that does special-case

  28263. ** work (enlarging the buffer) using tail recursion, so that the

  28264. ** sqlite3_str_append() routine can use fast calling semantics.

  28265. */

  28266. static void SQLITE_NOINLINE enlargeAndAppend(StrAccum *p, const char *z, int N){

  28267.   N = sqlite3StrAccumEnlarge(p, N);

  28268.   if( N>0 ){

  28269.     memcpy(&p->zText[p->nChar], z, N);

  28270.     p->nChar += N;

  28271.   }

  28272. }

  28273. 

  28274. /*

  28275. ** Append N bytes of text from z to the StrAccum object.  Increase the

  28276. ** size of the memory allocation for StrAccum if necessary.

  28277. */

  28278. SQLITE_API void sqlite3_str_append(sqlite3_str *p, const char *z, int N){

  28279.   assert( z!=0 || N==0 );

  28280.   assert( p->zText!=0 || p->nChar==0 || p->accError );

  28281.   assert( N>=0 );

  28282.   assert( p->accError==0 || p->nAlloc==0 || p->mxAlloc==0 );

  28283.   if( p->nChar+N >= p->nAlloc ){

  28284.     enlargeAndAppend(p,z,N);

  28285.   }else if( N ){

  28286.     assert( p->zText );

  28287.     p->nChar += N;

  28288.     memcpy(&p->zText[p->nChar-N], z, N);

  28289.   }

  28290. }

  28291. 

  28292. /*

  28293. ** Append the complete text of zero-terminated string z[] to the p string.

  28294. */

  28295. SQLITE_API void sqlite3_str_appendall(sqlite3_str *p, const char *z){

  28296.   sqlite3_str_append(p, z, sqlite3Strlen30(z));

  28297. }

  28298. 

  28299. 

  28300. /*

  28301. ** Finish off a string by making sure it is zero-terminated.

  28302. ** Return a pointer to the resulting string.  Return a NULL

  28303. ** pointer if any kind of error was encountered.

  28304. */

  28305. static SQLITE_NOINLINE char *strAccumFinishRealloc(StrAccum *p){

  28306.   char *zText;

  28307.   assert( p->mxAlloc>0 && !isMalloced(p) );

  28308.   zText = sqlite3DbMallocRaw(p->db, p->nChar+1 );

  28309.   if( zText ){

  28310.     memcpy(zText, p->zText, p->nChar+1);

  28311.     p->printfFlags |= SQLITE_PRINTF_MALLOCED;

  28312.   }else{

  28313.     setStrAccumError(p, SQLITE_NOMEM);

  28314.   }

  28315.   p->zText = zText;

  28316.   return zText;

  28317. }

  28318. SQLITE_PRIVATE char *sqlite3StrAccumFinish(StrAccum *p){

  28319.   if( p->zText ){

  28320.     p->zText[p->nChar] = 0;

  28321.     if( p->mxAlloc>0 && !isMalloced(p) ){

  28322.       return strAccumFinishRealloc(p);

  28323.     }

  28324.   }

  28325.   return p->zText;

  28326. }

  28327. 

  28328. /*

  28329. ** This singleton is an sqlite3_str object that is returned if

  28330. ** sqlite3_malloc() fails to provide space for a real one.  This

  28331. ** sqlite3_str object accepts no new text and always returns

  28332. ** an SQLITE_NOMEM error.

  28333. */

  28334. static sqlite3_str sqlite3OomStr = {

  28335.    0, 0, 0, 0, 0, SQLITE_NOMEM, 0

  28336. };

  28337. 

  28338. /* Finalize a string created using sqlite3_str_new().

  28339. */

  28340. SQLITE_API char *sqlite3_str_finish(sqlite3_str *p){

  28341.   char *z;

  28342.   if( p!=0 && p!=&sqlite3OomStr ){

  28343.     z = sqlite3StrAccumFinish(p);

  28344.     sqlite3_free(p);

  28345.   }else{

  28346.     z = 0;

  28347.   }

  28348.   return z;

  28349. }

  28350. 

  28351. /* Return any error code associated with p */

  28352. SQLITE_API int sqlite3_str_errcode(sqlite3_str *p){

  28353.   return p ? p->accError : SQLITE_NOMEM;

  28354. }

  28355. 

  28356. /* Return the current length of p in bytes */

  28357. SQLITE_API int sqlite3_str_length(sqlite3_str *p){

  28358.   return p ? p->nChar : 0;

  28359. }

  28360. 

  28361. /* Return the current value for p */

  28362. SQLITE_API char *sqlite3_str_value(sqlite3_str *p){

  28363.   if( p==0 || p->nChar==0 ) return 0;

  28364.   p->zText[p->nChar] = 0;

  28365.   return p->zText;

  28366. }

  28367. 

  28368. /*

  28369. ** Reset an StrAccum string.  Reclaim all malloced memory.

  28370. */

  28371. SQLITE_API void sqlite3_str_reset(StrAccum *p){

  28372.   if( isMalloced(p) ){

  28373.     sqlite3DbFree(p->db, p->zText);

  28374.     p->printfFlags &= ~SQLITE_PRINTF_MALLOCED;

  28375.   }

  28376.   p->nAlloc = 0;

  28377.   p->nChar = 0;

  28378.   p->zText = 0;

  28379. }

  28380. 

  28381. /*

  28382. ** Initialize a string accumulator.

  28383. **

  28384. ** p:     The accumulator to be initialized.

  28385. ** db:    Pointer to a database connection.  May be NULL.  Lookaside

  28386. **        memory is used if not NULL. db->mallocFailed is set appropriately

  28387. **        when not NULL.

  28388. ** zBase: An initial buffer.  May be NULL in which case the initial buffer

  28389. **        is malloced.

  28390. ** n:     Size of zBase in bytes.  If total space requirements never exceed

  28391. **        n then no memory allocations ever occur.

  28392. ** mx:    Maximum number of bytes to accumulate.  If mx==0 then no memory

  28393. **        allocations will ever occur.

  28394. */

  28395. SQLITE_PRIVATE void sqlite3StrAccumInit(StrAccum *p, sqlite3 *db, char *zBase, int n, int mx){

  28396.   p->zText = zBase;

  28397.   p->db = db;

  28398.   p->nAlloc = n;

  28399.   p->mxAlloc = mx;

  28400.   p->nChar = 0;

  28401.   p->accError = 0;

  28402.   p->printfFlags = 0;

  28403. }

  28404. 

  28405. /* Allocate and initialize a new dynamic string object */

  28406. SQLITE_API sqlite3_str *sqlite3_str_new(sqlite3 *db){

  28407.   sqlite3_str *p = sqlite3_malloc64(sizeof(*p));

  28408.   if( p ){

  28409.     sqlite3StrAccumInit(p, 0, 0, 0,

  28410.             db ? db->aLimit[SQLITE_LIMIT_LENGTH] : SQLITE_MAX_LENGTH);

  28411.   }else{

  28412.     p = &sqlite3OomStr;

  28413.   }

  28414.   return p;

  28415. }

  28416. 

  28417. /*

  28418. ** Print into memory obtained from sqliteMalloc().  Use the internal

  28419. ** %-conversion extensions.

  28420. */

  28421. SQLITE_PRIVATE char *sqlite3VMPrintf(sqlite3 *db, const char *zFormat, va_list ap){

  28422.   char *z;

  28423.   char zBase[SQLITE_PRINT_BUF_SIZE];

  28424.   StrAccum acc;

  28425.   assert( db!=0 );

  28426.   sqlite3StrAccumInit(&acc, db, zBase, sizeof(zBase),

  28427.                       db->aLimit[SQLITE_LIMIT_LENGTH]);

  28428.   acc.printfFlags = SQLITE_PRINTF_INTERNAL;

  28429.   sqlite3_str_vappendf(&acc, zFormat, ap);

  28430.   z = sqlite3StrAccumFinish(&acc);

  28431.   if( acc.accError==SQLITE_NOMEM ){

  28432.     sqlite3OomFault(db);

  28433.   }

  28434.   return z;

  28435. }

  28436. 

  28437. /*

  28438. ** Print into memory obtained from sqliteMalloc().  Use the internal

  28439. ** %-conversion extensions.

  28440. */

  28441. SQLITE_PRIVATE char *sqlite3MPrintf(sqlite3 *db, const char *zFormat, ...){

  28442.   va_list ap;

  28443.   char *z;

  28444.   va_start(ap, zFormat);

  28445.   z = sqlite3VMPrintf(db, zFormat, ap);

  28446.   va_end(ap);

  28447.   return z;

  28448. }

  28449. 

  28450. /*

  28451. ** Print into memory obtained from sqlite3_malloc().  Omit the internal

  28452. ** %-conversion extensions.

  28453. */

  28454. SQLITE_API char *sqlite3_vmprintf(const char *zFormat, va_list ap){

  28455.   char *z;

  28456.   char zBase[SQLITE_PRINT_BUF_SIZE];

  28457.   StrAccum acc;

  28458. 

  28459. #ifdef SQLITE_ENABLE_API_ARMOR  

  28460.   if( zFormat==0 ){

  28461.     (void)SQLITE_MISUSE_BKPT;

  28462.     return 0;

  28463.   }

  28464. #endif

  28465. #ifndef SQLITE_OMIT_AUTOINIT

  28466.   if( sqlite3_initialize() ) return 0;

  28467. #endif

  28468.   sqlite3StrAccumInit(&acc, 0, zBase, sizeof(zBase), SQLITE_MAX_LENGTH);

  28469.   sqlite3_str_vappendf(&acc, zFormat, ap);

  28470.   z = sqlite3StrAccumFinish(&acc);

  28471.   return z;

  28472. }

  28473. 

  28474. /*

  28475. ** Print into memory obtained from sqlite3_malloc()().  Omit the internal

  28476. ** %-conversion extensions.

  28477. */

  28478. SQLITE_API char *sqlite3_mprintf(const char *zFormat, ...){

  28479.   va_list ap;

  28480.   char *z;

  28481. #ifndef SQLITE_OMIT_AUTOINIT

  28482.   if( sqlite3_initialize() ) return 0;

  28483. #endif

  28484.   va_start(ap, zFormat);

  28485.   z = sqlite3_vmprintf(zFormat, ap);

  28486.   va_end(ap);

  28487.   return z;

  28488. }

  28489. 

  28490. /*

  28491. ** sqlite3_snprintf() works like snprintf() except that it ignores the

  28492. ** current locale settings.  This is important for SQLite because we

  28493. ** are not able to use a "," as the decimal point in place of "." as

  28494. ** specified by some locales.

  28495. **

  28496. ** Oops:  The first two arguments of sqlite3_snprintf() are backwards

  28497. ** from the snprintf() standard.  Unfortunately, it is too late to change

  28498. ** this without breaking compatibility, so we just have to live with the

  28499. ** mistake.

  28500. **

  28501. ** sqlite3_vsnprintf() is the varargs version.

  28502. */

  28503. SQLITE_API char *sqlite3_vsnprintf(int n, char *zBuf, const char *zFormat, va_list ap){

  28504.   StrAccum acc;

  28505.   if( n<=0 ) return zBuf;

  28506. #ifdef SQLITE_ENABLE_API_ARMOR

  28507.   if( zBuf==0 || zFormat==0 ) {

  28508.     (void)SQLITE_MISUSE_BKPT;

  28509.     if( zBuf ) zBuf[0] = 0;

  28510.     return zBuf;

  28511.   }

  28512. #endif

  28513.   sqlite3StrAccumInit(&acc, 0, zBuf, n, 0);

  28514.   sqlite3_str_vappendf(&acc, zFormat, ap);

  28515.   zBuf[acc.nChar] = 0;

  28516.   return zBuf;

  28517. }

  28518. SQLITE_API char *sqlite3_snprintf(int n, char *zBuf, const char *zFormat, ...){

  28519.   char *z;

  28520.   va_list ap;

  28521.   va_start(ap,zFormat);

  28522.   z = sqlite3_vsnprintf(n, zBuf, zFormat, ap);

  28523.   va_end(ap);

  28524.   return z;

  28525. }

  28526. 

  28527. /*

  28528. ** This is the routine that actually formats the sqlite3_log() message.

  28529. ** We house it in a separate routine from sqlite3_log() to avoid using

  28530. ** stack space on small-stack systems when logging is disabled.

  28531. **

  28532. ** sqlite3_log() must render into a static buffer.  It cannot dynamically

  28533. ** allocate memory because it might be called while the memory allocator

  28534. ** mutex is held.

  28535. **

  28536. ** sqlite3_str_vappendf() might ask for *temporary* memory allocations for

  28537. ** certain format characters (%q) or for very large precisions or widths.

  28538. ** Care must be taken that any sqlite3_log() calls that occur while the

  28539. ** memory mutex is held do not use these mechanisms.

  28540. */

  28541. static void renderLogMsg(int iErrCode, const char *zFormat, va_list ap){

  28542.   StrAccum acc;                          /* String accumulator */

  28543.   char zMsg[SQLITE_PRINT_BUF_SIZE*3];    /* Complete log message */

  28544. 

  28545.   sqlite3StrAccumInit(&acc, 0, zMsg, sizeof(zMsg), 0);

  28546.   sqlite3_str_vappendf(&acc, zFormat, ap);

  28547.   sqlite3GlobalConfig.xLog(sqlite3GlobalConfig.pLogArg, iErrCode,

  28548.                            sqlite3StrAccumFinish(&acc));

  28549. }

  28550. 

  28551. /*

  28552. ** Format and write a message to the log if logging is enabled.

  28553. */

  28554. SQLITE_API void sqlite3_log(int iErrCode, const char *zFormat, ...){

  28555.   va_list ap;                             /* Vararg list */

  28556.   if( sqlite3GlobalConfig.xLog ){

  28557.     va_start(ap, zFormat);

  28558.     renderLogMsg(iErrCode, zFormat, ap);

  28559.     va_end(ap);

  28560.   }

  28561. }

  28562. 

  28563. #if defined(SQLITE_DEBUG) || defined(SQLITE_HAVE_OS_TRACE)

  28564. /*

  28565. ** A version of printf() that understands %lld.  Used for debugging.

  28566. ** The printf() built into some versions of windows does not understand %lld

  28567. ** and segfaults if you give it a long long int.

  28568. */

  28569. SQLITE_PRIVATE void sqlite3DebugPrintf(const char *zFormat, ...){

  28570.   va_list ap;

  28571.   StrAccum acc;

  28572.   char zBuf[500];

  28573.   sqlite3StrAccumInit(&acc, 0, zBuf, sizeof(zBuf), 0);

  28574.   va_start(ap,zFormat);

  28575.   sqlite3_str_vappendf(&acc, zFormat, ap);

  28576.   va_end(ap);

  28577.   sqlite3StrAccumFinish(&acc);

  28578. #ifdef SQLITE_OS_TRACE_PROC

  28579.   {

  28580.     extern void SQLITE_OS_TRACE_PROC(const char *zBuf, int nBuf);

  28581.     SQLITE_OS_TRACE_PROC(zBuf, sizeof(zBuf));

  28582.   }

  28583. #else

  28584.   fprintf(stdout,"%s", zBuf);

  28585.   fflush(stdout);

  28586. #endif

  28587. }

  28588. #endif

  28589. 

  28590. 

  28591. /*

  28592. ** variable-argument wrapper around sqlite3_str_vappendf(). The bFlags argument

  28593. ** can contain the bit SQLITE_PRINTF_INTERNAL enable internal formats.

  28594. */

  28595. SQLITE_API void sqlite3_str_appendf(StrAccum *p, const char *zFormat, ...){

  28596.   va_list ap;

  28597.   va_start(ap,zFormat);

  28598.   sqlite3_str_vappendf(p, zFormat, ap);

  28599.   va_end(ap);

  28600. }

  28601. 

  28602. /************** End of printf.c **********************************************/

  28603. /************** Begin file treeview.c ****************************************/

  28604. /*

  28605. ** 2015-06-08

  28606. **

  28607. ** The author disclaims copyright to this source code.  In place of

  28608. ** a legal notice, here is a blessing:

  28609. **

  28610. **    May you do good and not evil.

  28611. **    May you find forgiveness for yourself and forgive others.

  28612. **    May you share freely, never taking more than you give.

  28613. **

  28614. *************************************************************************

  28615. **

  28616. ** This file contains C code to implement the TreeView debugging routines.

  28617. ** These routines print a parse tree to standard output for debugging and

  28618. ** analysis. 

  28619. **

  28620. ** The interfaces in this file is only available when compiling

  28621. ** with SQLITE_DEBUG.

  28622. */

  28623. /* #include "sqliteInt.h" */

  28624. #ifdef SQLITE_DEBUG

  28625. 

  28626. /*

  28627. ** Add a new subitem to the tree.  The moreToFollow flag indicates that this

  28628. ** is not the last item in the tree.

  28629. */

  28630. static TreeView *sqlite3TreeViewPush(TreeView *p, u8 moreToFollow){

  28631.   if( p==0 ){

  28632.     p = sqlite3_malloc64( sizeof(*p) );

  28633.     if( p==0 ) return 0;

  28634.     memset(p, 0, sizeof(*p));

  28635.   }else{

  28636.     p->iLevel++;

  28637.   }

  28638.   assert( moreToFollow==0 || moreToFollow==1 );

  28639.   if( p->iLevel<sizeof(p->bLine) ) p->bLine[p->iLevel] = moreToFollow;

  28640.   return p;

  28641. }

  28642. 

  28643. /*

  28644. ** Finished with one layer of the tree

  28645. */

  28646. static void sqlite3TreeViewPop(TreeView *p){

  28647.   if( p==0 ) return;

  28648.   p->iLevel--;

  28649.   if( p->iLevel<0 ) sqlite3_free(p);

  28650. }

  28651. 

  28652. /*

  28653. ** Generate a single line of output for the tree, with a prefix that contains

  28654. ** all the appropriate tree lines

  28655. */

  28656. static void sqlite3TreeViewLine(TreeView *p, const char *zFormat, ...){

  28657.   va_list ap;

  28658.   int i;

  28659.   StrAccum acc;

  28660.   char zBuf[500];

  28661.   sqlite3StrAccumInit(&acc, 0, zBuf, sizeof(zBuf), 0);

  28662.   if( p ){

  28663.     for(i=0; i<p->iLevel && i<sizeof(p->bLine)-1; i++){

  28664.       sqlite3_str_append(&acc, p->bLine[i] ? "|   " : "    ", 4);

  28665.     }

  28666.     sqlite3_str_append(&acc, p->bLine[i] ? "|-- " : "'-- ", 4);

  28667.   }

  28668.   if( zFormat!=0 ){

  28669.     va_start(ap, zFormat);

  28670.     sqlite3_str_vappendf(&acc, zFormat, ap);

  28671.     va_end(ap);

  28672.     assert( acc.nChar>0 );

  28673.     sqlite3_str_append(&acc, "\n", 1);

  28674.   }

  28675.   sqlite3StrAccumFinish(&acc);

  28676.   fprintf(stdout,"%s", zBuf);

  28677.   fflush(stdout);

  28678. }

  28679. 

  28680. /*

  28681. ** Shorthand for starting a new tree item that consists of a single label

  28682. */

  28683. static void sqlite3TreeViewItem(TreeView *p, const char *zLabel,u8 moreFollows){

  28684.   p = sqlite3TreeViewPush(p, moreFollows);

  28685.   sqlite3TreeViewLine(p, "%s", zLabel);

  28686. }

  28687. 

  28688. /*

  28689. ** Generate a human-readable description of a WITH clause.

  28690. */

  28691. SQLITE_PRIVATE void sqlite3TreeViewWith(TreeView *pView, const With *pWith, u8 moreToFollow){

  28692.   int i;

  28693.   if( pWith==0 ) return;

  28694.   if( pWith->nCte==0 ) return;

  28695.   if( pWith->pOuter ){

  28696.     sqlite3TreeViewLine(pView, "WITH (0x%p, pOuter=0x%p)",pWith,pWith->pOuter);

  28697.   }else{

  28698.     sqlite3TreeViewLine(pView, "WITH (0x%p)", pWith);

  28699.   }

  28700.   if( pWith->nCte>0 ){

  28701.     pView = sqlite3TreeViewPush(pView, 1);

  28702.     for(i=0; i<pWith->nCte; i++){

  28703.       StrAccum x;

  28704.       char zLine[1000];

  28705.       const struct Cte *pCte = &pWith->a[i];

  28706.       sqlite3StrAccumInit(&x, 0, zLine, sizeof(zLine), 0);

  28707.       sqlite3_str_appendf(&x, "%s", pCte->zName);

  28708.       if( pCte->pCols && pCte->pCols->nExpr>0 ){

  28709.         char cSep = '(';

  28710.         int j;

  28711.         for(j=0; j<pCte->pCols->nExpr; j++){

  28712.           sqlite3_str_appendf(&x, "%c%s", cSep, pCte->pCols->a[j].zName);

  28713.           cSep = ',';

  28714.         }

  28715.         sqlite3_str_appendf(&x, ")");

  28716.       }

  28717.       sqlite3_str_appendf(&x, " AS");

  28718.       sqlite3StrAccumFinish(&x);

  28719.       sqlite3TreeViewItem(pView, zLine, i<pWith->nCte-1);

  28720.       sqlite3TreeViewSelect(pView, pCte->pSelect, 0);

  28721.       sqlite3TreeViewPop(pView);

  28722.     }

  28723.     sqlite3TreeViewPop(pView);

  28724.   }

  28725. }

  28726. 

  28727. /*

  28728. ** Generate a human-readable description of a SrcList object.

  28729. */

  28730. SQLITE_PRIVATE void sqlite3TreeViewSrcList(TreeView *pView, const SrcList *pSrc){

  28731.   int i;

  28732.   for(i=0; i<pSrc->nSrc; i++){

  28733.     const struct SrcList_item *pItem = &pSrc->a[i];

  28734.     StrAccum x;

  28735.     char zLine[100];

  28736.     sqlite3StrAccumInit(&x, 0, zLine, sizeof(zLine), 0);

  28737.     sqlite3_str_appendf(&x, "{%d,*}", pItem->iCursor);

  28738.     if( pItem->zDatabase ){

  28739.       sqlite3_str_appendf(&x, " %s.%s", pItem->zDatabase, pItem->zName);

  28740.     }else if( pItem->zName ){

  28741.       sqlite3_str_appendf(&x, " %s", pItem->zName);

  28742.     }

  28743.     if( pItem->pTab ){

  28744.       sqlite3_str_appendf(&x, " tab=%Q nCol=%d ptr=%p",

  28745.            pItem->pTab->zName, pItem->pTab->nCol, pItem->pTab);

  28746.     }

  28747.     if( pItem->zAlias ){

  28748.       sqlite3_str_appendf(&x, " (AS %s)", pItem->zAlias);

  28749.     }

  28750.     if( pItem->fg.jointype & JT_LEFT ){

  28751.       sqlite3_str_appendf(&x, " LEFT-JOIN");

  28752.     }

  28753.     sqlite3StrAccumFinish(&x);

  28754.     sqlite3TreeViewItem(pView, zLine, i<pSrc->nSrc-1); 

  28755.     if( pItem->pSelect ){

  28756.       sqlite3TreeViewSelect(pView, pItem->pSelect, 0);

  28757.     }

  28758.     if( pItem->fg.isTabFunc ){

  28759.       sqlite3TreeViewExprList(pView, pItem->u1.pFuncArg, 0, "func-args:");

  28760.     }

  28761.     sqlite3TreeViewPop(pView);

  28762.   }

  28763. }

  28764. 

  28765. /*

  28766. ** Generate a human-readable description of a Select object.

  28767. */

  28768. SQLITE_PRIVATE void sqlite3TreeViewSelect(TreeView *pView, const Select *p, u8 moreToFollow){

  28769.   int n = 0;

  28770.   int cnt = 0;

  28771.   if( p==0 ){

  28772.     sqlite3TreeViewLine(pView, "nil-SELECT");

  28773.     return;

  28774.   } 

  28775.   pView = sqlite3TreeViewPush(pView, moreToFollow);

  28776.   if( p->pWith ){

  28777.     sqlite3TreeViewWith(pView, p->pWith, 1);

  28778.     cnt = 1;

  28779.     sqlite3TreeViewPush(pView, 1);

  28780.   }

  28781.   do{

  28782.     sqlite3TreeViewLine(pView,

  28783.       "SELECT%s%s (%u/%p) selFlags=0x%x nSelectRow=%d",

  28784.       ((p->selFlags & SF_Distinct) ? " DISTINCT" : ""),

  28785.       ((p->selFlags & SF_Aggregate) ? " agg_flag" : ""),

  28786.       p->selId, p, p->selFlags,

  28787.       (int)p->nSelectRow

  28788.     );

  28789.     if( cnt++ ) sqlite3TreeViewPop(pView);

  28790.     if( p->pPrior ){

  28791.       n = 1000;

  28792.     }else{

  28793.       n = 0;

  28794.       if( p->pSrc && p->pSrc->nSrc ) n++;

  28795.       if( p->pWhere ) n++;

  28796.       if( p->pGroupBy ) n++;

  28797.       if( p->pHaving ) n++;

  28798.       if( p->pOrderBy ) n++;

  28799.       if( p->pLimit ) n++;

  28800. #ifndef SQLITE_OMIT_WINDOWFUNC

  28801.       if( p->pWin ) n++;

  28802.       if( p->pWinDefn ) n++;

  28803. #endif

  28804.     }

  28805.     sqlite3TreeViewExprList(pView, p->pEList, (n--)>0, "result-set");

  28806. #ifndef SQLITE_OMIT_WINDOWFUNC

  28807.     if( p->pWin ){

  28808.       Window *pX;

  28809.       pView = sqlite3TreeViewPush(pView, (n--)>0);

  28810.       sqlite3TreeViewLine(pView, "window-functions");

  28811.       for(pX=p->pWin; pX; pX=pX->pNextWin){

  28812.         sqlite3TreeViewWinFunc(pView, pX, pX->pNextWin!=0);

  28813.       }

  28814.       sqlite3TreeViewPop(pView);

  28815.     }

  28816. #endif

  28817.     if( p->pSrc && p->pSrc->nSrc ){

  28818.       pView = sqlite3TreeViewPush(pView, (n--)>0);

  28819.       sqlite3TreeViewLine(pView, "FROM");

  28820.       sqlite3TreeViewSrcList(pView, p->pSrc);

  28821.       sqlite3TreeViewPop(pView);

  28822.     }

  28823.     if( p->pWhere ){

  28824.       sqlite3TreeViewItem(pView, "WHERE", (n--)>0);

  28825.       sqlite3TreeViewExpr(pView, p->pWhere, 0);

  28826.       sqlite3TreeViewPop(pView);

  28827.     }

  28828.     if( p->pGroupBy ){

  28829.       sqlite3TreeViewExprList(pView, p->pGroupBy, (n--)>0, "GROUPBY");

  28830.     }

  28831.     if( p->pHaving ){

  28832.       sqlite3TreeViewItem(pView, "HAVING", (n--)>0);

  28833.       sqlite3TreeViewExpr(pView, p->pHaving, 0);

  28834.       sqlite3TreeViewPop(pView);

  28835.     }

  28836. #ifndef SQLITE_OMIT_WINDOWFUNC

  28837.     if( p->pWinDefn ){

  28838.       Window *pX;

  28839.       sqlite3TreeViewItem(pView, "WINDOW", (n--)>0);

  28840.       for(pX=p->pWinDefn; pX; pX=pX->pNextWin){

  28841.         sqlite3TreeViewWindow(pView, pX, pX->pNextWin!=0);

  28842.       }

  28843.       sqlite3TreeViewPop(pView);

  28844.     }

  28845. #endif

  28846.     if( p->pOrderBy ){

  28847.       sqlite3TreeViewExprList(pView, p->pOrderBy, (n--)>0, "ORDERBY");

  28848.     }

  28849.     if( p->pLimit ){

  28850.       sqlite3TreeViewItem(pView, "LIMIT", (n--)>0);

  28851.       sqlite3TreeViewExpr(pView, p->pLimit->pLeft, p->pLimit->pRight!=0);

  28852.       if( p->pLimit->pRight ){

  28853.         sqlite3TreeViewItem(pView, "OFFSET", (n--)>0);

  28854.         sqlite3TreeViewExpr(pView, p->pLimit->pRight, 0);

  28855.         sqlite3TreeViewPop(pView);

  28856.       }

  28857.       sqlite3TreeViewPop(pView);

  28858.     }

  28859.     if( p->pPrior ){

  28860.       const char *zOp = "UNION";

  28861.       switch( p->op ){

  28862.         case TK_ALL:         zOp = "UNION ALL";  break;

  28863.         case TK_INTERSECT:   zOp = "INTERSECT";  break;

  28864.         case TK_EXCEPT:      zOp = "EXCEPT";     break;

  28865.       }

  28866.       sqlite3TreeViewItem(pView, zOp, 1);

  28867.     }

  28868.     p = p->pPrior;

  28869.   }while( p!=0 );

  28870.   sqlite3TreeViewPop(pView);

  28871. }

  28872. 

  28873. #ifndef SQLITE_OMIT_WINDOWFUNC

  28874. /*

  28875. ** Generate a description of starting or stopping bounds

  28876. */

  28877. SQLITE_PRIVATE void sqlite3TreeViewBound(

  28878.   TreeView *pView,        /* View context */

  28879.   u8 eBound,              /* UNBOUNDED, CURRENT, PRECEDING, FOLLOWING */

  28880.   Expr *pExpr,            /* Value for PRECEDING or FOLLOWING */

  28881.   u8 moreToFollow         /* True if more to follow */

  28882. ){

  28883.   switch( eBound ){

  28884.     case TK_UNBOUNDED: {

  28885.       sqlite3TreeViewItem(pView, "UNBOUNDED", moreToFollow);

  28886.       sqlite3TreeViewPop(pView);

  28887.       break;

  28888.     }

  28889.     case TK_CURRENT: {

  28890.       sqlite3TreeViewItem(pView, "CURRENT", moreToFollow);

  28891.       sqlite3TreeViewPop(pView);

  28892.       break;

  28893.     }

  28894.     case TK_PRECEDING: {

  28895.       sqlite3TreeViewItem(pView, "PRECEDING", moreToFollow);

  28896.       sqlite3TreeViewExpr(pView, pExpr, 0);

  28897.       sqlite3TreeViewPop(pView);

  28898.       break;

  28899.     }

  28900.     case TK_FOLLOWING: {

  28901.       sqlite3TreeViewItem(pView, "FOLLOWING", moreToFollow);

  28902.       sqlite3TreeViewExpr(pView, pExpr, 0);

  28903.       sqlite3TreeViewPop(pView);

  28904.       break;

  28905.     }

  28906.   }

  28907. }

  28908. #endif /* SQLITE_OMIT_WINDOWFUNC */

  28909. 

  28910. #ifndef SQLITE_OMIT_WINDOWFUNC

  28911. /*

  28912. ** Generate a human-readable explanation for a Window object

  28913. */

  28914. SQLITE_PRIVATE void sqlite3TreeViewWindow(TreeView *pView, const Window *pWin, u8 more){

  28915.   int nElement = 0;

  28916.   if( pWin->pFilter ){

  28917.     sqlite3TreeViewItem(pView, "FILTER", 1);

  28918.     sqlite3TreeViewExpr(pView, pWin->pFilter, 0);

  28919.     sqlite3TreeViewPop(pView);

  28920.   }

  28921.   pView = sqlite3TreeViewPush(pView, more);

  28922.   if( pWin->zName ){

  28923.     sqlite3TreeViewLine(pView, "OVER %s (%p)", pWin->zName, pWin);

  28924.   }else{

  28925.     sqlite3TreeViewLine(pView, "OVER (%p)", pWin);

  28926.   }

  28927.   if( pWin->zBase )    nElement++;

  28928.   if( pWin->pOrderBy ) nElement++;

  28929.   if( pWin->eFrmType ) nElement++;

  28930.   if( pWin->eExclude ) nElement++;

  28931.   if( pWin->zBase ){

  28932.     sqlite3TreeViewPush(pView, (--nElement)>0);

  28933.     sqlite3TreeViewLine(pView, "window: %s", pWin->zBase);

  28934.     sqlite3TreeViewPop(pView);

  28935.   }

  28936.   if( pWin->pPartition ){

  28937.     sqlite3TreeViewExprList(pView, pWin->pPartition, nElement>0,"PARTITION-BY");

  28938.   }

  28939.   if( pWin->pOrderBy ){

  28940.     sqlite3TreeViewExprList(pView, pWin->pOrderBy, (--nElement)>0, "ORDER-BY");

  28941.   }

  28942.   if( pWin->eFrmType ){

  28943.     char zBuf[30];

  28944.     const char *zFrmType = "ROWS";

  28945.     if( pWin->eFrmType==TK_RANGE ) zFrmType = "RANGE";

  28946.     if( pWin->eFrmType==TK_GROUPS ) zFrmType = "GROUPS";

  28947.     sqlite3_snprintf(sizeof(zBuf),zBuf,"%s%s",zFrmType,

  28948.         pWin->bImplicitFrame ? " (implied)" : "");

  28949.     sqlite3TreeViewItem(pView, zBuf, (--nElement)>0);

  28950.     sqlite3TreeViewBound(pView, pWin->eStart, pWin->pStart, 1);

  28951.     sqlite3TreeViewBound(pView, pWin->eEnd, pWin->pEnd, 0);

  28952.     sqlite3TreeViewPop(pView);

  28953.   }

  28954.   if( pWin->eExclude ){

  28955.     char zBuf[30];

  28956.     const char *zExclude;

  28957.     switch( pWin->eExclude ){

  28958.       case TK_NO:      zExclude = "NO OTHERS";   break;

  28959.       case TK_CURRENT: zExclude = "CURRENT ROW"; break;

  28960.       case TK_GROUP:   zExclude = "GROUP";       break;

  28961.       case TK_TIES:    zExclude = "TIES";        break;

  28962.       default:

  28963.         sqlite3_snprintf(sizeof(zBuf),zBuf,"invalid(%d)", pWin->eExclude);

  28964.         zExclude = zBuf;

  28965.         break;

  28966.     }

  28967.     sqlite3TreeViewPush(pView, 0);

  28968.     sqlite3TreeViewLine(pView, "EXCLUDE %s", zExclude);

  28969.     sqlite3TreeViewPop(pView);

  28970.   }

  28971.   sqlite3TreeViewPop(pView);

  28972. }

  28973. #endif /* SQLITE_OMIT_WINDOWFUNC */

  28974. 

  28975. #ifndef SQLITE_OMIT_WINDOWFUNC

  28976. /*

  28977. ** Generate a human-readable explanation for a Window Function object

  28978. */

  28979. SQLITE_PRIVATE void sqlite3TreeViewWinFunc(TreeView *pView, const Window *pWin, u8 more){

  28980.   pView = sqlite3TreeViewPush(pView, more);

  28981.   sqlite3TreeViewLine(pView, "WINFUNC %s(%d)",

  28982.                        pWin->pFunc->zName, pWin->pFunc->nArg);

  28983.   sqlite3TreeViewWindow(pView, pWin, 0);

  28984.   sqlite3TreeViewPop(pView);

  28985. }

  28986. #endif /* SQLITE_OMIT_WINDOWFUNC */

  28987. 

  28988. /*

  28989. ** Generate a human-readable explanation of an expression tree.

  28990. */

  28991. SQLITE_PRIVATE void sqlite3TreeViewExpr(TreeView *pView, const Expr *pExpr, u8 moreToFollow){

  28992.   const char *zBinOp = 0;   /* Binary operator */

  28993.   const char *zUniOp = 0;   /* Unary operator */

  28994.   char zFlgs[60];

  28995.   pView = sqlite3TreeViewPush(pView, moreToFollow);

  28996.   if( pExpr==0 ){

  28997.     sqlite3TreeViewLine(pView, "nil");

  28998.     sqlite3TreeViewPop(pView);

  28999.     return;

  29000.   }

  29001.   if( pExpr->flags ){

  29002.     if( ExprHasProperty(pExpr, EP_FromJoin) ){

  29003.       sqlite3_snprintf(sizeof(zFlgs),zFlgs,"  flags=0x%x iRJT=%d",

  29004.                        pExpr->flags, pExpr->iRightJoinTable);

  29005.     }else{

  29006.       sqlite3_snprintf(sizeof(zFlgs),zFlgs,"  flags=0x%x",pExpr->flags);

  29007.     }

  29008.   }else{

  29009.     zFlgs[0] = 0;

  29010.   }

  29011.   switch( pExpr->op ){

  29012.     case TK_AGG_COLUMN: {

  29013.       sqlite3TreeViewLine(pView, "AGG{%d:%d}%s",

  29014.             pExpr->iTable, pExpr->iColumn, zFlgs);

  29015.       break;

  29016.     }

  29017.     case TK_COLUMN: {

  29018.       if( pExpr->iTable<0 ){

  29019.         /* This only happens when coding check constraints */

  29020.         sqlite3TreeViewLine(pView, "COLUMN(%d)%s", pExpr->iColumn, zFlgs);

  29021.       }else{

  29022.         sqlite3TreeViewLine(pView, "{%d:%d}%s",

  29023.                              pExpr->iTable, pExpr->iColumn, zFlgs);

  29024.       }

  29025.       if( ExprHasProperty(pExpr, EP_FixedCol) ){

  29026.         sqlite3TreeViewExpr(pView, pExpr->pLeft, 0);

  29027.       }

  29028.       break;

  29029.     }

  29030.     case TK_INTEGER: {

  29031.       if( pExpr->flags & EP_IntValue ){

  29032.         sqlite3TreeViewLine(pView, "%d", pExpr->u.iValue);

  29033.       }else{

  29034.         sqlite3TreeViewLine(pView, "%s", pExpr->u.zToken);

  29035.       }

  29036.       break;

  29037.     }

  29038. #ifndef SQLITE_OMIT_FLOATING_POINT

  29039.     case TK_FLOAT: {

  29040.       sqlite3TreeViewLine(pView,"%s", pExpr->u.zToken);

  29041.       break;

  29042.     }

  29043. #endif

  29044.     case TK_STRING: {

  29045.       sqlite3TreeViewLine(pView,"%Q", pExpr->u.zToken);

  29046.       break;

  29047.     }

  29048.     case TK_NULL: {

  29049.       sqlite3TreeViewLine(pView,"NULL");

  29050.       break;

  29051.     }

  29052.     case TK_TRUEFALSE: {

  29053.       sqlite3TreeViewLine(pView,

  29054.          sqlite3ExprTruthValue(pExpr) ? "TRUE" : "FALSE");

  29055.       break;

  29056.     }

  29057. #ifndef SQLITE_OMIT_BLOB_LITERAL

  29058.     case TK_BLOB: {

  29059.       sqlite3TreeViewLine(pView,"%s", pExpr->u.zToken);

  29060.       break;

  29061.     }

  29062. #endif

  29063.     case TK_VARIABLE: {

  29064.       sqlite3TreeViewLine(pView,"VARIABLE(%s,%d)",

  29065.                           pExpr->u.zToken, pExpr->iColumn);

  29066.       break;

  29067.     }

  29068.     case TK_REGISTER: {

  29069.       sqlite3TreeViewLine(pView,"REGISTER(%d)", pExpr->iTable);

  29070.       break;

  29071.     }

  29072.     case TK_ID: {

  29073.       sqlite3TreeViewLine(pView,"ID \"%w\"", pExpr->u.zToken);

  29074.       break;

  29075.     }

  29076. #ifndef SQLITE_OMIT_CAST

  29077.     case TK_CAST: {

  29078.       /* Expressions of the form:   CAST(pLeft AS token) */

  29079.       sqlite3TreeViewLine(pView,"CAST %Q", pExpr->u.zToken);

  29080.       sqlite3TreeViewExpr(pView, pExpr->pLeft, 0);

  29081.       break;

  29082.     }

  29083. #endif /* SQLITE_OMIT_CAST */

  29084.     case TK_LT:      zBinOp = "LT";     break;

  29085.     case TK_LE:      zBinOp = "LE";     break;

  29086.     case TK_GT:      zBinOp = "GT";     break;

  29087.     case TK_GE:      zBinOp = "GE";     break;

  29088.     case TK_NE:      zBinOp = "NE";     break;

  29089.     case TK_EQ:      zBinOp = "EQ";     break;

  29090.     case TK_IS:      zBinOp = "IS";     break;

  29091.     case TK_ISNOT:   zBinOp = "ISNOT";  break;

  29092.     case TK_AND:     zBinOp = "AND";    break;

  29093.     case TK_OR:      zBinOp = "OR";     break;

  29094.     case TK_PLUS:    zBinOp = "ADD";    break;

  29095.     case TK_STAR:    zBinOp = "MUL";    break;

  29096.     case TK_MINUS:   zBinOp = "SUB";    break;

  29097.     case TK_REM:     zBinOp = "REM";    break;

  29098.     case TK_BITAND:  zBinOp = "BITAND"; break;

  29099.     case TK_BITOR:   zBinOp = "BITOR";  break;

  29100.     case TK_SLASH:   zBinOp = "DIV";    break;

  29101.     case TK_LSHIFT:  zBinOp = "LSHIFT"; break;

  29102.     case TK_RSHIFT:  zBinOp = "RSHIFT"; break;

  29103.     case TK_CONCAT:  zBinOp = "CONCAT"; break;

  29104.     case TK_DOT:     zBinOp = "DOT";    break;

  29105. 

  29106.     case TK_UMINUS:  zUniOp = "UMINUS"; break;

  29107.     case TK_UPLUS:   zUniOp = "UPLUS";  break;

  29108.     case TK_BITNOT:  zUniOp = "BITNOT"; break;

  29109.     case TK_NOT:     zUniOp = "NOT";    break;

  29110.     case TK_ISNULL:  zUniOp = "ISNULL"; break;

  29111.     case TK_NOTNULL: zUniOp = "NOTNULL"; break;

  29112. 

  29113.     case TK_TRUTH: {

  29114.       int x;

  29115.       const char *azOp[] = {

  29116.          "IS-FALSE", "IS-TRUE", "IS-NOT-FALSE", "IS-NOT-TRUE"

  29117.       };

  29118.       assert( pExpr->op2==TK_IS || pExpr->op2==TK_ISNOT );

  29119.       assert( pExpr->pRight );

  29120.       assert( sqlite3ExprSkipCollate(pExpr->pRight)->op==TK_TRUEFALSE );

  29121.       x = (pExpr->op2==TK_ISNOT)*2 + sqlite3ExprTruthValue(pExpr->pRight);

  29122.       zUniOp = azOp[x];

  29123.       break;

  29124.     }

  29125. 

  29126.     case TK_SPAN: {

  29127.       sqlite3TreeViewLine(pView, "SPAN %Q", pExpr->u.zToken);

  29128.       sqlite3TreeViewExpr(pView, pExpr->pLeft, 0);

  29129.       break;

  29130.     }

  29131. 

  29132.     case TK_COLLATE: {

  29133.       sqlite3TreeViewLine(pView, "COLLATE %Q", pExpr->u.zToken);

  29134.       sqlite3TreeViewExpr(pView, pExpr->pLeft, 0);

  29135.       break;

  29136.     }

  29137. 

  29138.     case TK_AGG_FUNCTION:

  29139.     case TK_FUNCTION: {

  29140.       ExprList *pFarg;       /* List of function arguments */

  29141.       Window *pWin;

  29142.       if( ExprHasProperty(pExpr, EP_TokenOnly) ){

  29143.         pFarg = 0;

  29144.         pWin = 0;

  29145.       }else{

  29146.         pFarg = pExpr->x.pList;

  29147. #ifndef SQLITE_OMIT_WINDOWFUNC

  29148.         pWin = pExpr->y.pWin;

  29149. #else

  29150.         pWin = 0;

  29151. #endif 

  29152.       }

  29153.       if( pExpr->op==TK_AGG_FUNCTION ){

  29154.         sqlite3TreeViewLine(pView, "AGG_FUNCTION%d %Q",

  29155.                              pExpr->op2, pExpr->u.zToken);

  29156.       }else{

  29157.         sqlite3TreeViewLine(pView, "FUNCTION %Q", pExpr->u.zToken);

  29158.       }

  29159.       if( pFarg ){

  29160.         sqlite3TreeViewExprList(pView, pFarg, pWin!=0, 0);

  29161.       }

  29162. #ifndef SQLITE_OMIT_WINDOWFUNC

  29163.       if( pWin ){

  29164.         sqlite3TreeViewWindow(pView, pWin, 0);

  29165.       }

  29166. #endif

  29167.       break;

  29168.     }

  29169. #ifndef SQLITE_OMIT_SUBQUERY

  29170.     case TK_EXISTS: {

  29171.       sqlite3TreeViewLine(pView, "EXISTS-expr flags=0x%x", pExpr->flags);

  29172.       sqlite3TreeViewSelect(pView, pExpr->x.pSelect, 0);

  29173.       break;

  29174.     }

  29175.     case TK_SELECT: {

  29176.       sqlite3TreeViewLine(pView, "SELECT-expr flags=0x%x", pExpr->flags);

  29177.       sqlite3TreeViewSelect(pView, pExpr->x.pSelect, 0);

  29178.       break;

  29179.     }

  29180.     case TK_IN: {

  29181.       sqlite3TreeViewLine(pView, "IN flags=0x%x", pExpr->flags);

  29182.       sqlite3TreeViewExpr(pView, pExpr->pLeft, 1);

  29183.       if( ExprHasProperty(pExpr, EP_xIsSelect) ){

  29184.         sqlite3TreeViewSelect(pView, pExpr->x.pSelect, 0);

  29185.       }else{

  29186.         sqlite3TreeViewExprList(pView, pExpr->x.pList, 0, 0);

  29187.       }

  29188.       break;

  29189.     }

  29190. #endif /* SQLITE_OMIT_SUBQUERY */

  29191. 

  29192.     /*

  29193.     **    x BETWEEN y AND z

  29194.     **

  29195.     ** This is equivalent to

  29196.     **

  29197.     **    x>=y AND x<=z

  29198.     **

  29199.     ** X is stored in pExpr->pLeft.

  29200.     ** Y is stored in pExpr->pList->a[0].pExpr.

  29201.     ** Z is stored in pExpr->pList->a[1].pExpr.

  29202.     */

  29203.     case TK_BETWEEN: {

  29204.       Expr *pX = pExpr->pLeft;

  29205.       Expr *pY = pExpr->x.pList->a[0].pExpr;

  29206.       Expr *pZ = pExpr->x.pList->a[1].pExpr;

  29207.       sqlite3TreeViewLine(pView, "BETWEEN");

  29208.       sqlite3TreeViewExpr(pView, pX, 1);

  29209.       sqlite3TreeViewExpr(pView, pY, 1);

  29210.       sqlite3TreeViewExpr(pView, pZ, 0);

  29211.       break;

  29212.     }

  29213.     case TK_TRIGGER: {

  29214.       /* If the opcode is TK_TRIGGER, then the expression is a reference

  29215.       ** to a column in the new.* or old.* pseudo-tables available to

  29216.       ** trigger programs. In this case Expr.iTable is set to 1 for the

  29217.       ** new.* pseudo-table, or 0 for the old.* pseudo-table. Expr.iColumn

  29218.       ** is set to the column of the pseudo-table to read, or to -1 to

  29219.       ** read the rowid field.

  29220.       */

  29221.       sqlite3TreeViewLine(pView, "%s(%d)", 

  29222.           pExpr->iTable ? "NEW" : "OLD", pExpr->iColumn);

  29223.       break;

  29224.     }

  29225.     case TK_CASE: {

  29226.       sqlite3TreeViewLine(pView, "CASE");

  29227.       sqlite3TreeViewExpr(pView, pExpr->pLeft, 1);

  29228.       sqlite3TreeViewExprList(pView, pExpr->x.pList, 0, 0);

  29229.       break;

  29230.     }

  29231. #ifndef SQLITE_OMIT_TRIGGER

  29232.     case TK_RAISE: {

  29233.       const char *zType = "unk";

  29234.       switch( pExpr->affinity ){

  29235.         case OE_Rollback:   zType = "rollback";  break;

  29236.         case OE_Abort:      zType = "abort";     break;

  29237.         case OE_Fail:       zType = "fail";      break;

  29238.         case OE_Ignore:     zType = "ignore";    break;

  29239.       }

  29240.       sqlite3TreeViewLine(pView, "RAISE %s(%Q)", zType, pExpr->u.zToken);

  29241.       break;

  29242.     }

  29243. #endif

  29244.     case TK_MATCH: {

  29245.       sqlite3TreeViewLine(pView, "MATCH {%d:%d}%s",

  29246.                           pExpr->iTable, pExpr->iColumn, zFlgs);

  29247.       sqlite3TreeViewExpr(pView, pExpr->pRight, 0);

  29248.       break;

  29249.     }

  29250.     case TK_VECTOR: {

  29251.       sqlite3TreeViewBareExprList(pView, pExpr->x.pList, "VECTOR");

  29252.       break;

  29253.     }

  29254.     case TK_SELECT_COLUMN: {

  29255.       sqlite3TreeViewLine(pView, "SELECT-COLUMN %d", pExpr->iColumn);

  29256.       sqlite3TreeViewSelect(pView, pExpr->pLeft->x.pSelect, 0);

  29257.       break;

  29258.     }

  29259.     case TK_IF_NULL_ROW: {

  29260.       sqlite3TreeViewLine(pView, "IF-NULL-ROW %d", pExpr->iTable);

  29261.       sqlite3TreeViewExpr(pView, pExpr->pLeft, 0);

  29262.       break;

  29263.     }

  29264.     default: {

  29265.       sqlite3TreeViewLine(pView, "op=%d", pExpr->op);

  29266.       break;

  29267.     }

  29268.   }

  29269.   if( zBinOp ){

  29270.     sqlite3TreeViewLine(pView, "%s%s", zBinOp, zFlgs);

  29271.     sqlite3TreeViewExpr(pView, pExpr->pLeft, 1);

  29272.     sqlite3TreeViewExpr(pView, pExpr->pRight, 0);

  29273.   }else if( zUniOp ){

  29274.     sqlite3TreeViewLine(pView, "%s%s", zUniOp, zFlgs);

  29275.     sqlite3TreeViewExpr(pView, pExpr->pLeft, 0);

  29276.   }

  29277.   sqlite3TreeViewPop(pView);

  29278. }

  29279. 

  29280. 

  29281. /*

  29282. ** Generate a human-readable explanation of an expression list.

  29283. */

  29284. SQLITE_PRIVATE void sqlite3TreeViewBareExprList(

  29285.   TreeView *pView,

  29286.   const ExprList *pList,

  29287.   const char *zLabel

  29288. ){

  29289.   if( zLabel==0 || zLabel[0]==0 ) zLabel = "LIST";

  29290.   if( pList==0 ){

  29291.     sqlite3TreeViewLine(pView, "%s (empty)", zLabel);

  29292.   }else{

  29293.     int i;

  29294.     sqlite3TreeViewLine(pView, "%s", zLabel);

  29295.     for(i=0; i<pList->nExpr; i++){

  29296.       int j = pList->a[i].u.x.iOrderByCol;

  29297.       char *zName = pList->a[i].zName;

  29298.       int moreToFollow = i<pList->nExpr - 1;

  29299.       if( j || zName ){

  29300.         sqlite3TreeViewPush(pView, moreToFollow);

  29301.         moreToFollow = 0;

  29302.         sqlite3TreeViewLine(pView, 0);

  29303.         if( zName ){

  29304.           fprintf(stdout, "AS %s ", zName);

  29305.         }

  29306.         if( j ){

  29307.           fprintf(stdout, "iOrderByCol=%d", j);

  29308.         }

  29309.         fprintf(stdout, "\n");

  29310.         fflush(stdout);

  29311.       }

  29312.       sqlite3TreeViewExpr(pView, pList->a[i].pExpr, moreToFollow);

  29313.       if( j || zName ){

  29314.         sqlite3TreeViewPop(pView);

  29315.       }

  29316.     }

  29317.   }

  29318. }

  29319. SQLITE_PRIVATE void sqlite3TreeViewExprList(

  29320.   TreeView *pView,

  29321.   const ExprList *pList,

  29322.   u8 moreToFollow,

  29323.   const char *zLabel

  29324. ){

  29325.   pView = sqlite3TreeViewPush(pView, moreToFollow);

  29326.   sqlite3TreeViewBareExprList(pView, pList, zLabel);

  29327.   sqlite3TreeViewPop(pView);

  29328. }

  29329. 

  29330. #endif /* SQLITE_DEBUG */

  29331. 

  29332. /************** End of treeview.c ********************************************/

  29333. /************** Begin file random.c ******************************************/

  29334. /*

  29335. ** 2001 September 15

  29336. **

  29337. ** The author disclaims copyright to this source code.  In place of

  29338. ** a legal notice, here is a blessing:

  29339. **

  29340. **    May you do good and not evil.

  29341. **    May you find forgiveness for yourself and forgive others.

  29342. **    May you share freely, never taking more than you give.

  29343. **

  29344. *************************************************************************

  29345. ** This file contains code to implement a pseudo-random number

  29346. ** generator (PRNG) for SQLite.

  29347. **

  29348. ** Random numbers are used by some of the database backends in order

  29349. ** to generate random integer keys for tables or random filenames.

  29350. */

  29351. /* #include "sqliteInt.h" */

  29352. 

  29353. 

  29354. /* All threads share a single random number generator.

  29355. ** This structure is the current state of the generator.

  29356. */

  29357. static SQLITE_WSD struct sqlite3PrngType {

  29358.   unsigned char isInit;          /* True if initialized */

  29359.   unsigned char i, j;            /* State variables */

  29360.   unsigned char s[256];          /* State variables */

  29361. } sqlite3Prng;

  29362. 

  29363. /*

  29364. ** Return N random bytes.

  29365. */

  29366. SQLITE_API void sqlite3_randomness(int N, void *pBuf){

  29367.   unsigned char t;

  29368.   unsigned char *zBuf = pBuf;

  29369. 

  29370.   /* The "wsdPrng" macro will resolve to the pseudo-random number generator

  29371.   ** state vector.  If writable static data is unsupported on the target,

  29372.   ** we have to locate the state vector at run-time.  In the more common

  29373.   ** case where writable static data is supported, wsdPrng can refer directly

  29374.   ** to the "sqlite3Prng" state vector declared above.

  29375.   */

  29376. #ifdef SQLITE_OMIT_WSD

  29377.   struct sqlite3PrngType *p = &GLOBAL(struct sqlite3PrngType, sqlite3Prng);

  29378. # define wsdPrng p[0]

  29379. #else

  29380. # define wsdPrng sqlite3Prng

  29381. #endif

  29382. 

  29383. #if SQLITE_THREADSAFE

  29384.   sqlite3_mutex *mutex;

  29385. #endif

  29386. 

  29387. #ifndef SQLITE_OMIT_AUTOINIT

  29388.   if( sqlite3_initialize() ) return;

  29389. #endif

  29390. 

  29391. #if SQLITE_THREADSAFE

  29392.   mutex = sqlite3MutexAlloc(SQLITE_MUTEX_STATIC_PRNG);

  29393. #endif

  29394. 

  29395.   sqlite3_mutex_enter(mutex);

  29396.   if( N<=0 || pBuf==0 ){

  29397.     wsdPrng.isInit = 0;

  29398.     sqlite3_mutex_leave(mutex);

  29399.     return;

  29400.   }

  29401. 

  29402.   /* Initialize the state of the random number generator once,

  29403.   ** the first time this routine is called.  The seed value does

  29404.   ** not need to contain a lot of randomness since we are not

  29405.   ** trying to do secure encryption or anything like that...

  29406.   **

  29407.   ** Nothing in this file or anywhere else in SQLite does any kind of

  29408.   ** encryption.  The RC4 algorithm is being used as a PRNG (pseudo-random

  29409.   ** number generator) not as an encryption device.

  29410.   */

  29411.   if( !wsdPrng.isInit ){

  29412.     int i;

  29413.     char k[256];

  29414.     wsdPrng.j = 0;

  29415.     wsdPrng.i = 0;

  29416.     sqlite3OsRandomness(sqlite3_vfs_find(0), 256, k);

  29417.     for(i=0; i<256; i++){

  29418.       wsdPrng.s[i] = (u8)i;

  29419.     }

  29420.     for(i=0; i<256; i++){

  29421.       wsdPrng.j += wsdPrng.s[i] + k[i];

  29422.       t = wsdPrng.s[wsdPrng.j];

  29423.       wsdPrng.s[wsdPrng.j] = wsdPrng.s[i];

  29424.       wsdPrng.s[i] = t;

  29425.     }

  29426.     wsdPrng.isInit = 1;

  29427.   }

  29428. 

  29429.   assert( N>0 );

  29430.   do{

  29431.     wsdPrng.i++;

  29432.     t = wsdPrng.s[wsdPrng.i];

  29433.     wsdPrng.j += t;

  29434.     wsdPrng.s[wsdPrng.i] = wsdPrng.s[wsdPrng.j];

  29435.     wsdPrng.s[wsdPrng.j] = t;

  29436.     t += wsdPrng.s[wsdPrng.i];

  29437.     *(zBuf++) = wsdPrng.s[t];

  29438.   }while( --N );

  29439.   sqlite3_mutex_leave(mutex);

  29440. }

  29441. 

  29442. #ifndef SQLITE_UNTESTABLE

  29443. /*

  29444. ** For testing purposes, we sometimes want to preserve the state of

  29445. ** PRNG and restore the PRNG to its saved state at a later time, or

  29446. ** to reset the PRNG to its initial state.  These routines accomplish

  29447. ** those tasks.

  29448. **

  29449. ** The sqlite3_test_control() interface calls these routines to

  29450. ** control the PRNG.

  29451. */

  29452. static SQLITE_WSD struct sqlite3PrngType sqlite3SavedPrng;

  29453. SQLITE_PRIVATE void sqlite3PrngSaveState(void){

  29454.   memcpy(

  29455.     &GLOBAL(struct sqlite3PrngType, sqlite3SavedPrng),

  29456.     &GLOBAL(struct sqlite3PrngType, sqlite3Prng),

  29457.     sizeof(sqlite3Prng)

  29458.   );

  29459. }

  29460. SQLITE_PRIVATE void sqlite3PrngRestoreState(void){

  29461.   memcpy(

  29462.     &GLOBAL(struct sqlite3PrngType, sqlite3Prng),

  29463.     &GLOBAL(struct sqlite3PrngType, sqlite3SavedPrng),

  29464.     sizeof(sqlite3Prng)

  29465.   );

  29466. }

  29467. #endif /* SQLITE_UNTESTABLE */

  29468. 

  29469. /************** End of random.c **********************************************/

  29470. /************** Begin file threads.c *****************************************/

  29471. /*

  29472. ** 2012 July 21

  29473. **

  29474. ** The author disclaims copyright to this source code.  In place of

  29475. ** a legal notice, here is a blessing:

  29476. **

  29477. **    May you do good and not evil.

  29478. **    May you find forgiveness for yourself and forgive others.

  29479. **    May you share freely, never taking more than you give.

  29480. **

  29481. ******************************************************************************

  29482. **

  29483. ** This file presents a simple cross-platform threading interface for

  29484. ** use internally by SQLite.

  29485. **

  29486. ** A "thread" can be created using sqlite3ThreadCreate().  This thread

  29487. ** runs independently of its creator until it is joined using

  29488. ** sqlite3ThreadJoin(), at which point it terminates.

  29489. **

  29490. ** Threads do not have to be real.  It could be that the work of the

  29491. ** "thread" is done by the main thread at either the sqlite3ThreadCreate()

  29492. ** or sqlite3ThreadJoin() call.  This is, in fact, what happens in

  29493. ** single threaded systems.  Nothing in SQLite requires multiple threads.

  29494. ** This interface exists so that applications that want to take advantage

  29495. ** of multiple cores can do so, while also allowing applications to stay

  29496. ** single-threaded if desired.

  29497. */

  29498. /* #include "sqliteInt.h" */

  29499. #if SQLITE_OS_WIN

  29500. /* #  include "os_win.h" */

  29501. #endif

  29502. 

  29503. #if SQLITE_MAX_WORKER_THREADS>0

  29504. 

  29505. /********************************* Unix Pthreads ****************************/

  29506. #if SQLITE_OS_UNIX && defined(SQLITE_MUTEX_PTHREADS) && SQLITE_THREADSAFE>0

  29507. 

  29508. #define SQLITE_THREADS_IMPLEMENTED 1  /* Prevent the single-thread code below */

  29509. /* #include <pthread.h> */

  29510. 

  29511. /* A running thread */

  29512. struct SQLiteThread {

  29513.   pthread_t tid;                 /* Thread ID */

  29514.   int done;                      /* Set to true when thread finishes */

  29515.   void *pOut;                    /* Result returned by the thread */

  29516.   void *(*xTask)(void*);         /* The thread routine */

  29517.   void *pIn;                     /* Argument to the thread */

  29518. };

  29519. 

  29520. /* Create a new thread */

  29521. SQLITE_PRIVATE int sqlite3ThreadCreate(

  29522.   SQLiteThread **ppThread,  /* OUT: Write the thread object here */

  29523.   void *(*xTask)(void*),    /* Routine to run in a separate thread */

  29524.   void *pIn                 /* Argument passed into xTask() */

  29525. ){

  29526.   SQLiteThread *p;

  29527.   int rc;

  29528. 

  29529.   assert( ppThread!=0 );

  29530.   assert( xTask!=0 );

  29531.   /* This routine is never used in single-threaded mode */

  29532.   assert( sqlite3GlobalConfig.bCoreMutex!=0 );

  29533. 

  29534.   *ppThread = 0;

  29535.   p = sqlite3Malloc(sizeof(*p));

  29536.   if( p==0 ) return SQLITE_NOMEM_BKPT;

  29537.   memset(p, 0, sizeof(*p));

  29538.   p->xTask = xTask;

  29539.   p->pIn = pIn;

  29540.   /* If the SQLITE_TESTCTRL_FAULT_INSTALL callback is registered to a 

  29541.   ** function that returns SQLITE_ERROR when passed the argument 200, that

  29542.   ** forces worker threads to run sequentially and deterministically 

  29543.   ** for testing purposes. */

  29544.   if( sqlite3FaultSim(200) ){

  29545.     rc = 1;

  29546.   }else{    

  29547.     rc = pthread_create(&p->tid, 0, xTask, pIn);

  29548.   }

  29549.   if( rc ){

  29550.     p->done = 1;

  29551.     p->pOut = xTask(pIn);

  29552.   }

  29553.   *ppThread = p;

  29554.   return SQLITE_OK;

  29555. }

  29556. 

  29557. /* Get the results of the thread */

  29558. SQLITE_PRIVATE int sqlite3ThreadJoin(SQLiteThread *p, void **ppOut){

  29559.   int rc;

  29560. 

  29561.   assert( ppOut!=0 );

  29562.   if( NEVER(p==0) ) return SQLITE_NOMEM_BKPT;

  29563.   if( p->done ){

  29564.     *ppOut = p->pOut;

  29565.     rc = SQLITE_OK;

  29566.   }else{

  29567.     rc = pthread_join(p->tid, ppOut) ? SQLITE_ERROR : SQLITE_OK;

  29568.   }

  29569.   sqlite3_free(p);

  29570.   return rc;

  29571. }

  29572. 

  29573. #endif /* SQLITE_OS_UNIX && defined(SQLITE_MUTEX_PTHREADS) */

  29574. /******************************** End Unix Pthreads *************************/

  29575. 

  29576. 

  29577. /********************************* Win32 Threads ****************************/

  29578. #if SQLITE_OS_WIN_THREADS

  29579. 

  29580. #define SQLITE_THREADS_IMPLEMENTED 1  /* Prevent the single-thread code below */

  29581. #include <process.h>

  29582. 

  29583. /* A running thread */

  29584. struct SQLiteThread {

  29585.   void *tid;               /* The thread handle */

  29586.   unsigned id;             /* The thread identifier */

  29587.   void *(*xTask)(void*);   /* The routine to run as a thread */

  29588.   void *pIn;               /* Argument to xTask */

  29589.   void *pResult;           /* Result of xTask */

  29590. };

  29591. 

  29592. /* Thread procedure Win32 compatibility shim */

  29593. static unsigned __stdcall sqlite3ThreadProc(

  29594.   void *pArg  /* IN: Pointer to the SQLiteThread structure */

  29595. ){

  29596.   SQLiteThread *p = (SQLiteThread *)pArg;

  29597. 

  29598.   assert( p!=0 );

  29599. #if 0

  29600.   /*

  29601.   ** This assert appears to trigger spuriously on certain

  29602.   ** versions of Windows, possibly due to _beginthreadex()

  29603.   ** and/or CreateThread() not fully setting their thread

  29604.   ** ID parameter before starting the thread.

  29605.   */

  29606.   assert( p->id==GetCurrentThreadId() );

  29607. #endif

  29608.   assert( p->xTask!=0 );

  29609.   p->pResult = p->xTask(p->pIn);

  29610. 

  29611.   _endthreadex(0);

  29612.   return 0; /* NOT REACHED */

  29613. }

  29614. 

  29615. /* Create a new thread */

  29616. SQLITE_PRIVATE int sqlite3ThreadCreate(

  29617.   SQLiteThread **ppThread,  /* OUT: Write the thread object here */

  29618.   void *(*xTask)(void*),    /* Routine to run in a separate thread */

  29619.   void *pIn                 /* Argument passed into xTask() */

  29620. ){

  29621.   SQLiteThread *p;

  29622. 

  29623.   assert( ppThread!=0 );

  29624.   assert( xTask!=0 );

  29625.   *ppThread = 0;

  29626.   p = sqlite3Malloc(sizeof(*p));

  29627.   if( p==0 ) return SQLITE_NOMEM_BKPT;

  29628.   /* If the SQLITE_TESTCTRL_FAULT_INSTALL callback is registered to a 

  29629.   ** function that returns SQLITE_ERROR when passed the argument 200, that

  29630.   ** forces worker threads to run sequentially and deterministically 

  29631.   ** (via the sqlite3FaultSim() term of the conditional) for testing

  29632.   ** purposes. */

  29633.   if( sqlite3GlobalConfig.bCoreMutex==0 || sqlite3FaultSim(200) ){

  29634.     memset(p, 0, sizeof(*p));

  29635.   }else{

  29636.     p->xTask = xTask;

  29637.     p->pIn = pIn;

  29638.     p->tid = (void*)_beginthreadex(0, 0, sqlite3ThreadProc, p, 0, &p->id);

  29639.     if( p->tid==0 ){

  29640.       memset(p, 0, sizeof(*p));

  29641.     }

  29642.   }

  29643.   if( p->xTask==0 ){

  29644.     p->id = GetCurrentThreadId();

  29645.     p->pResult = xTask(pIn);

  29646.   }

  29647.   *ppThread = p;

  29648.   return SQLITE_OK;

  29649. }

  29650. 

  29651. SQLITE_PRIVATE DWORD sqlite3Win32Wait(HANDLE hObject); /* os_win.c */

  29652. 

  29653. /* Get the results of the thread */

  29654. SQLITE_PRIVATE int sqlite3ThreadJoin(SQLiteThread *p, void **ppOut){

  29655.   DWORD rc;

  29656.   BOOL bRc;

  29657. 

  29658.   assert( ppOut!=0 );

  29659.   if( NEVER(p==0) ) return SQLITE_NOMEM_BKPT;

  29660.   if( p->xTask==0 ){

  29661.     /* assert( p->id==GetCurrentThreadId() ); */

  29662.     rc = WAIT_OBJECT_0;

  29663.     assert( p->tid==0 );

  29664.   }else{

  29665.     assert( p->id!=0 && p->id!=GetCurrentThreadId() );

  29666.     rc = sqlite3Win32Wait((HANDLE)p->tid);

  29667.     assert( rc!=WAIT_IO_COMPLETION );

  29668.     bRc = CloseHandle((HANDLE)p->tid);

  29669.     assert( bRc );

  29670.   }

  29671.   if( rc==WAIT_OBJECT_0 ) *ppOut = p->pResult;

  29672.   sqlite3_free(p);

  29673.   return (rc==WAIT_OBJECT_0) ? SQLITE_OK : SQLITE_ERROR;

  29674. }

  29675. 

  29676. #endif /* SQLITE_OS_WIN_THREADS */

  29677. /******************************** End Win32 Threads *************************/

  29678. 

  29679. 

  29680. /********************************* Single-Threaded **************************/

  29681. #ifndef SQLITE_THREADS_IMPLEMENTED

  29682. /*

  29683. ** This implementation does not actually create a new thread.  It does the

  29684. ** work of the thread in the main thread, when either the thread is created

  29685. ** or when it is joined

  29686. */

  29687. 

  29688. /* A running thread */

  29689. struct SQLiteThread {

  29690.   void *(*xTask)(void*);   /* The routine to run as a thread */

  29691.   void *pIn;               /* Argument to xTask */

  29692.   void *pResult;           /* Result of xTask */

  29693. };

  29694. 

  29695. /* Create a new thread */

  29696. SQLITE_PRIVATE int sqlite3ThreadCreate(

  29697.   SQLiteThread **ppThread,  /* OUT: Write the thread object here */

  29698.   void *(*xTask)(void*),    /* Routine to run in a separate thread */

  29699.   void *pIn                 /* Argument passed into xTask() */

  29700. ){

  29701.   SQLiteThread *p;

  29702. 

  29703.   assert( ppThread!=0 );

  29704.   assert( xTask!=0 );

  29705.   *ppThread = 0;

  29706.   p = sqlite3Malloc(sizeof(*p));

  29707.   if( p==0 ) return SQLITE_NOMEM_BKPT;

  29708.   if( (SQLITE_PTR_TO_INT(p)/17)&1 ){

  29709.     p->xTask = xTask;

  29710.     p->pIn = pIn;

  29711.   }else{

  29712.     p->xTask = 0;

  29713.     p->pResult = xTask(pIn);

  29714.   }

  29715.   *ppThread = p;

  29716.   return SQLITE_OK;

  29717. }

  29718. 

  29719. /* Get the results of the thread */

  29720. SQLITE_PRIVATE int sqlite3ThreadJoin(SQLiteThread *p, void **ppOut){

  29721. 

  29722.   assert( ppOut!=0 );

  29723.   if( NEVER(p==0) ) return SQLITE_NOMEM_BKPT;

  29724.   if( p->xTask ){

  29725.     *ppOut = p->xTask(p->pIn);

  29726.   }else{

  29727.     *ppOut = p->pResult;

  29728.   }

  29729.   sqlite3_free(p);

  29730. 

  29731. #if defined(SQLITE_TEST)

  29732.   {

  29733.     void *pTstAlloc = sqlite3Malloc(10);

  29734.     if (!pTstAlloc) return SQLITE_NOMEM_BKPT;

  29735.     sqlite3_free(pTstAlloc);

  29736.   }

  29737. #endif

  29738. 

  29739.   return SQLITE_OK;

  29740. }

  29741. 

  29742. #endif /* !defined(SQLITE_THREADS_IMPLEMENTED) */

  29743. /****************************** End Single-Threaded *************************/

  29744. #endif /* SQLITE_MAX_WORKER_THREADS>0 */

  29745. 

  29746. /************** End of threads.c *********************************************/

  29747. /************** Begin file utf.c *********************************************/

  29748. /*

  29749. ** 2004 April 13

  29750. **

  29751. ** The author disclaims copyright to this source code.  In place of

  29752. ** a legal notice, here is a blessing:

  29753. **

  29754. **    May you do good and not evil.

  29755. **    May you find forgiveness for yourself and forgive others.

  29756. **    May you share freely, never taking more than you give.

  29757. **

  29758. *************************************************************************

  29759. ** This file contains routines used to translate between UTF-8, 

  29760. ** UTF-16, UTF-16BE, and UTF-16LE.

  29761. **

  29762. ** Notes on UTF-8:

  29763. **

  29764. **   Byte-0    Byte-1    Byte-2    Byte-3    Value

  29765. **  0xxxxxxx                                 00000000 00000000 0xxxxxxx

  29766. **  110yyyyy  10xxxxxx                       00000000 00000yyy yyxxxxxx

  29767. **  1110zzzz  10yyyyyy  10xxxxxx             00000000 zzzzyyyy yyxxxxxx

  29768. **  11110uuu  10uuzzzz  10yyyyyy  10xxxxxx   000uuuuu zzzzyyyy yyxxxxxx

  29769. **

  29770. **

  29771. ** Notes on UTF-16:  (with wwww+1==uuuuu)

  29772. **

  29773. **      Word-0               Word-1          Value

  29774. **  110110ww wwzzzzyy   110111yy yyxxxxxx    000uuuuu zzzzyyyy yyxxxxxx

  29775. **  zzzzyyyy yyxxxxxx                        00000000 zzzzyyyy yyxxxxxx

  29776. **

  29777. **

  29778. ** BOM or Byte Order Mark:

  29779. **     0xff 0xfe   little-endian utf-16 follows

  29780. **     0xfe 0xff   big-endian utf-16 follows

  29781. **

  29782. */

  29783. /* #include "sqliteInt.h" */

  29784. /* #include <assert.h> */

  29785. /* #include "vdbeInt.h" */

  29786. 

  29787. #if !defined(SQLITE_AMALGAMATION) && SQLITE_BYTEORDER==0

  29788. /*

  29789. ** The following constant value is used by the SQLITE_BIGENDIAN and

  29790. ** SQLITE_LITTLEENDIAN macros.

  29791. */

  29792. SQLITE_PRIVATE const int sqlite3one = 1;

  29793. #endif /* SQLITE_AMALGAMATION && SQLITE_BYTEORDER==0 */

  29794. 

  29795. /*

  29796. ** This lookup table is used to help decode the first byte of

  29797. ** a multi-byte UTF8 character.

  29798. */

  29799. static const unsigned char sqlite3Utf8Trans1[] = {

  29800.   0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07,

  29801.   0x08, 0x09, 0x0a, 0x0b, 0x0c, 0x0d, 0x0e, 0x0f,

  29802.   0x10, 0x11, 0x12, 0x13, 0x14, 0x15, 0x16, 0x17,

  29803.   0x18, 0x19, 0x1a, 0x1b, 0x1c, 0x1d, 0x1e, 0x1f,

  29804.   0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07,

  29805.   0x08, 0x09, 0x0a, 0x0b, 0x0c, 0x0d, 0x0e, 0x0f,

  29806.   0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07,

  29807.   0x00, 0x01, 0x02, 0x03, 0x00, 0x01, 0x00, 0x00,

  29808. };

  29809. 

  29810. 

  29811. #define WRITE_UTF8(zOut, c) {                          \

  29812.   if( c<0x00080 ){                                     \

  29813.     *zOut++ = (u8)(c&0xFF);                            \

  29814.   }                                                    \

  29815.   else if( c<0x00800 ){                                \

  29816.     *zOut++ = 0xC0 + (u8)((c>>6)&0x1F);                \

  29817.     *zOut++ = 0x80 + (u8)(c & 0x3F);                   \

  29818.   }                                                    \

  29819.   else if( c<0x10000 ){                                \

  29820.     *zOut++ = 0xE0 + (u8)((c>>12)&0x0F);               \

  29821.     *zOut++ = 0x80 + (u8)((c>>6) & 0x3F);              \

  29822.     *zOut++ = 0x80 + (u8)(c & 0x3F);                   \

  29823.   }else{                                               \

  29824.     *zOut++ = 0xF0 + (u8)((c>>18) & 0x07);             \

  29825.     *zOut++ = 0x80 + (u8)((c>>12) & 0x3F);             \

  29826.     *zOut++ = 0x80 + (u8)((c>>6) & 0x3F);              \

  29827.     *zOut++ = 0x80 + (u8)(c & 0x3F);                   \

  29828.   }                                                    \

  29829. }

  29830. 

  29831. #define WRITE_UTF16LE(zOut, c) {                                    \

  29832.   if( c<=0xFFFF ){                                                  \

  29833.     *zOut++ = (u8)(c&0x00FF);                                       \

  29834.     *zOut++ = (u8)((c>>8)&0x00FF);                                  \

  29835.   }else{                                                            \

  29836.     *zOut++ = (u8)(((c>>10)&0x003F) + (((c-0x10000)>>10)&0x00C0));  \

  29837.     *zOut++ = (u8)(0x00D8 + (((c-0x10000)>>18)&0x03));              \

  29838.     *zOut++ = (u8)(c&0x00FF);                                       \

  29839.     *zOut++ = (u8)(0x00DC + ((c>>8)&0x03));                         \

  29840.   }                                                                 \

  29841. }

  29842. 

  29843. #define WRITE_UTF16BE(zOut, c) {                                    \

  29844.   if( c<=0xFFFF ){                                                  \

  29845.     *zOut++ = (u8)((c>>8)&0x00FF);                                  \

  29846.     *zOut++ = (u8)(c&0x00FF);                                       \

  29847.   }else{                                                            \

  29848.     *zOut++ = (u8)(0x00D8 + (((c-0x10000)>>18)&0x03));              \

  29849.     *zOut++ = (u8)(((c>>10)&0x003F) + (((c-0x10000)>>10)&0x00C0));  \

  29850.     *zOut++ = (u8)(0x00DC + ((c>>8)&0x03));                         \

  29851.     *zOut++ = (u8)(c&0x00FF);                                       \

  29852.   }                                                                 \

  29853. }

  29854. 

  29855. #define READ_UTF16LE(zIn, TERM, c){                                   \

  29856.   c = (*zIn++);                                                       \

  29857.   c += ((*zIn++)<<8);                                                 \

  29858.   if( c>=0xD800 && c<0xE000 && TERM ){                                \

  29859.     int c2 = (*zIn++);                                                \

  29860.     c2 += ((*zIn++)<<8);                                              \

  29861.     c = (c2&0x03FF) + ((c&0x003F)<<10) + (((c&0x03C0)+0x0040)<<10);   \

  29862.   }                                                                   \

  29863. }

  29864. 

  29865. #define READ_UTF16BE(zIn, TERM, c){                                   \

  29866.   c = ((*zIn++)<<8);                                                  \

  29867.   c += (*zIn++);                                                      \

  29868.   if( c>=0xD800 && c<0xE000 && TERM ){                                \

  29869.     int c2 = ((*zIn++)<<8);                                           \

  29870.     c2 += (*zIn++);                                                   \

  29871.     c = (c2&0x03FF) + ((c&0x003F)<<10) + (((c&0x03C0)+0x0040)<<10);   \

  29872.   }                                                                   \

  29873. }

  29874. 

  29875. /*

  29876. ** Translate a single UTF-8 character.  Return the unicode value.

  29877. **

  29878. ** During translation, assume that the byte that zTerm points

  29879. ** is a 0x00.

  29880. **

  29881. ** Write a pointer to the next unread byte back into *pzNext.

  29882. **

  29883. ** Notes On Invalid UTF-8:

  29884. **

  29885. **  *  This routine never allows a 7-bit character (0x00 through 0x7f) to

  29886. **     be encoded as a multi-byte character.  Any multi-byte character that

  29887. **     attempts to encode a value between 0x00 and 0x7f is rendered as 0xfffd.

  29888. **

  29889. **  *  This routine never allows a UTF16 surrogate value to be encoded.

  29890. **     If a multi-byte character attempts to encode a value between

  29891. **     0xd800 and 0xe000 then it is rendered as 0xfffd.

  29892. **

  29893. **  *  Bytes in the range of 0x80 through 0xbf which occur as the first

  29894. **     byte of a character are interpreted as single-byte characters

  29895. **     and rendered as themselves even though they are technically

  29896. **     invalid characters.

  29897. **

  29898. **  *  This routine accepts over-length UTF8 encodings

  29899. **     for unicode values 0x80 and greater.  It does not change over-length

  29900. **     encodings to 0xfffd as some systems recommend.

  29901. */

  29902. #define READ_UTF8(zIn, zTerm, c)                           \

  29903.   c = *(zIn++);                                            \

  29904.   if( c>=0xc0 ){                                           \

  29905.     c = sqlite3Utf8Trans1[c-0xc0];                         \

  29906.     while( zIn!=zTerm && (*zIn & 0xc0)==0x80 ){            \

  29907.       c = (c<<6) + (0x3f & *(zIn++));                      \

  29908.     }                                                      \

  29909.     if( c<0x80                                             \

  29910.         || (c&0xFFFFF800)==0xD800                          \

  29911.         || (c&0xFFFFFFFE)==0xFFFE ){  c = 0xFFFD; }        \

  29912.   }

  29913. SQLITE_PRIVATE u32 sqlite3Utf8Read(

  29914.   const unsigned char **pz    /* Pointer to string from which to read char */

  29915. ){

  29916.   unsigned int c;

  29917. 

  29918.   /* Same as READ_UTF8() above but without the zTerm parameter.

  29919.   ** For this routine, we assume the UTF8 string is always zero-terminated.

  29920.   */

  29921.   c = *((*pz)++);

  29922.   if( c>=0xc0 ){

  29923.     c = sqlite3Utf8Trans1[c-0xc0];

  29924.     while( (*(*pz) & 0xc0)==0x80 ){

  29925.       c = (c<<6) + (0x3f & *((*pz)++));

  29926.     }

  29927.     if( c<0x80

  29928.         || (c&0xFFFFF800)==0xD800

  29929.         || (c&0xFFFFFFFE)==0xFFFE ){  c = 0xFFFD; }

  29930.   }

  29931.   return c;

  29932. }

  29933. 

  29934. 

  29935. 

  29936. 

  29937. /*

  29938. ** If the TRANSLATE_TRACE macro is defined, the value of each Mem is

  29939. ** printed on stderr on the way into and out of sqlite3VdbeMemTranslate().

  29940. */ 

  29941. /* #define TRANSLATE_TRACE 1 */

  29942. 

  29943. #ifndef SQLITE_OMIT_UTF16

  29944. /*

  29945. ** This routine transforms the internal text encoding used by pMem to

  29946. ** desiredEnc. It is an error if the string is already of the desired

  29947. ** encoding, or if *pMem does not contain a string value.

  29948. */

  29949. SQLITE_PRIVATE SQLITE_NOINLINE int sqlite3VdbeMemTranslate(Mem *pMem, u8 desiredEnc){

  29950.   sqlite3_int64 len;          /* Maximum length of output string in bytes */

  29951.   unsigned char *zOut;        /* Output buffer */

  29952.   unsigned char *zIn;         /* Input iterator */

  29953.   unsigned char *zTerm;       /* End of input */

  29954.   unsigned char *z;           /* Output iterator */

  29955.   unsigned int c;

  29956. 

  29957.   assert( pMem->db==0 || sqlite3_mutex_held(pMem->db->mutex) );

  29958.   assert( pMem->flags&MEM_Str );

  29959.   assert( pMem->enc!=desiredEnc );

  29960.   assert( pMem->enc!=0 );

  29961.   assert( pMem->n>=0 );

  29962. 

  29963. #if defined(TRANSLATE_TRACE) && defined(SQLITE_DEBUG)

  29964.   {

  29965.     char zBuf[100];

  29966.     sqlite3VdbeMemPrettyPrint(pMem, zBuf);

  29967.     fprintf(stderr, "INPUT:  %s\n", zBuf);

  29968.   }

  29969. #endif

  29970. 

  29971.   /* If the translation is between UTF-16 little and big endian, then 

  29972.   ** all that is required is to swap the byte order. This case is handled

  29973.   ** differently from the others.

  29974.   */

  29975.   if( pMem->enc!=SQLITE_UTF8 && desiredEnc!=SQLITE_UTF8 ){

  29976.     u8 temp;

  29977.     int rc;

  29978.     rc = sqlite3VdbeMemMakeWriteable(pMem);

  29979.     if( rc!=SQLITE_OK ){

  29980.       assert( rc==SQLITE_NOMEM );

  29981.       return SQLITE_NOMEM_BKPT;

  29982.     }

  29983.     zIn = (u8*)pMem->z;

  29984.     zTerm = &zIn[pMem->n&~1];

  29985.     while( zIn<zTerm ){

  29986.       temp = *zIn;

  29987.       *zIn = *(zIn+1);

  29988.       zIn++;

  29989.       *zIn++ = temp;

  29990.     }

  29991.     pMem->enc = desiredEnc;

  29992.     goto translate_out;

  29993.   }

  29994. 

  29995.   /* Set len to the maximum number of bytes required in the output buffer. */

  29996.   if( desiredEnc==SQLITE_UTF8 ){

  29997.     /* When converting from UTF-16, the maximum growth results from

  29998.     ** translating a 2-byte character to a 4-byte UTF-8 character.

  29999.     ** A single byte is required for the output string

  30000.     ** nul-terminator.

  30001.     */

  30002.     pMem->n &= ~1;

  30003.     len = 2 * (sqlite3_int64)pMem->n + 1;

  30004.   }else{

  30005.     /* When converting from UTF-8 to UTF-16 the maximum growth is caused

  30006.     ** when a 1-byte UTF-8 character is translated into a 2-byte UTF-16

  30007.     ** character. Two bytes are required in the output buffer for the

  30008.     ** nul-terminator.

  30009.     */

  30010.     len = 2 * (sqlite3_int64)pMem->n + 2;

  30011.   }

  30012. 

  30013.   /* Set zIn to point at the start of the input buffer and zTerm to point 1

  30014.   ** byte past the end.

  30015.   **

  30016.   ** Variable zOut is set to point at the output buffer, space obtained

  30017.   ** from sqlite3_malloc().

  30018.   */

  30019.   zIn = (u8*)pMem->z;

  30020.   zTerm = &zIn[pMem->n];

  30021.   zOut = sqlite3DbMallocRaw(pMem->db, len);

  30022.   if( !zOut ){

  30023.     return SQLITE_NOMEM_BKPT;

  30024.   }

  30025.   z = zOut;

  30026. 

  30027.   if( pMem->enc==SQLITE_UTF8 ){

  30028.     if( desiredEnc==SQLITE_UTF16LE ){

  30029.       /* UTF-8 -> UTF-16 Little-endian */

  30030.       while( zIn<zTerm ){

  30031.         READ_UTF8(zIn, zTerm, c);

  30032.         WRITE_UTF16LE(z, c);

  30033.       }

  30034.     }else{

  30035.       assert( desiredEnc==SQLITE_UTF16BE );

  30036.       /* UTF-8 -> UTF-16 Big-endian */

  30037.       while( zIn<zTerm ){

  30038.         READ_UTF8(zIn, zTerm, c);

  30039.         WRITE_UTF16BE(z, c);

  30040.       }

  30041.     }

  30042.     pMem->n = (int)(z - zOut);

  30043.     *z++ = 0;

  30044.   }else{

  30045.     assert( desiredEnc==SQLITE_UTF8 );

  30046.     if( pMem->enc==SQLITE_UTF16LE ){

  30047.       /* UTF-16 Little-endian -> UTF-8 */

  30048.       while( zIn<zTerm ){

  30049.         READ_UTF16LE(zIn, zIn<zTerm, c); 

  30050.         WRITE_UTF8(z, c);

  30051.       }

  30052.     }else{

  30053.       /* UTF-16 Big-endian -> UTF-8 */

  30054.       while( zIn<zTerm ){

  30055.         READ_UTF16BE(zIn, zIn<zTerm, c); 

  30056.         WRITE_UTF8(z, c);

  30057.       }

  30058.     }

  30059.     pMem->n = (int)(z - zOut);

  30060.   }

  30061.   *z = 0;

  30062.   assert( (pMem->n+(desiredEnc==SQLITE_UTF8?1:2))<=len );

  30063. 

  30064.   c = pMem->flags;

  30065.   sqlite3VdbeMemRelease(pMem);

  30066.   pMem->flags = MEM_Str|MEM_Term|(c&(MEM_AffMask|MEM_Subtype));

  30067.   pMem->enc = desiredEnc;

  30068.   pMem->z = (char*)zOut;

  30069.   pMem->zMalloc = pMem->z;

  30070.   pMem->szMalloc = sqlite3DbMallocSize(pMem->db, pMem->z);

  30071. 

  30072. translate_out:

  30073. #if defined(TRANSLATE_TRACE) && defined(SQLITE_DEBUG)

  30074.   {

  30075.     char zBuf[100];

  30076.     sqlite3VdbeMemPrettyPrint(pMem, zBuf);

  30077.     fprintf(stderr, "OUTPUT: %s\n", zBuf);

  30078.   }

  30079. #endif

  30080.   return SQLITE_OK;

  30081. }

  30082. #endif /* SQLITE_OMIT_UTF16 */

  30083. 

  30084. #ifndef SQLITE_OMIT_UTF16

  30085. /*

  30086. ** This routine checks for a byte-order mark at the beginning of the 

  30087. ** UTF-16 string stored in *pMem. If one is present, it is removed and

  30088. ** the encoding of the Mem adjusted. This routine does not do any

  30089. ** byte-swapping, it just sets Mem.enc appropriately.

  30090. **

  30091. ** The allocation (static, dynamic etc.) and encoding of the Mem may be

  30092. ** changed by this function.

  30093. */

  30094. SQLITE_PRIVATE int sqlite3VdbeMemHandleBom(Mem *pMem){

  30095.   int rc = SQLITE_OK;

  30096.   u8 bom = 0;

  30097. 

  30098.   assert( pMem->n>=0 );

  30099.   if( pMem->n>1 ){

  30100.     u8 b1 = *(u8 *)pMem->z;

  30101.     u8 b2 = *(((u8 *)pMem->z) + 1);

  30102.     if( b1==0xFE && b2==0xFF ){

  30103.       bom = SQLITE_UTF16BE;

  30104.     }

  30105.     if( b1==0xFF && b2==0xFE ){

  30106.       bom = SQLITE_UTF16LE;

  30107.     }

  30108.   }

  30109.   

  30110.   if( bom ){

  30111.     rc = sqlite3VdbeMemMakeWriteable(pMem);

  30112.     if( rc==SQLITE_OK ){

  30113.       pMem->n -= 2;

  30114.       memmove(pMem->z, &pMem->z[2], pMem->n);

  30115.       pMem->z[pMem->n] = '\0';

  30116.       pMem->z[pMem->n+1] = '\0';

  30117.       pMem->flags |= MEM_Term;

  30118.       pMem->enc = bom;

  30119.     }

  30120.   }

  30121.   return rc;

  30122. }

  30123. #endif /* SQLITE_OMIT_UTF16 */

  30124. 

  30125. /*

  30126. ** pZ is a UTF-8 encoded unicode string. If nByte is less than zero,

  30127. ** return the number of unicode characters in pZ up to (but not including)

  30128. ** the first 0x00 byte. If nByte is not less than zero, return the

  30129. ** number of unicode characters in the first nByte of pZ (or up to 

  30130. ** the first 0x00, whichever comes first).

  30131. */

  30132. SQLITE_PRIVATE int sqlite3Utf8CharLen(const char *zIn, int nByte){

  30133.   int r = 0;

  30134.   const u8 *z = (const u8*)zIn;

  30135.   const u8 *zTerm;

  30136.   if( nByte>=0 ){

  30137.     zTerm = &z[nByte];

  30138.   }else{

  30139.     zTerm = (const u8*)(-1);

  30140.   }

  30141.   assert( z<=zTerm );

  30142.   while( *z!=0 && z<zTerm ){

  30143.     SQLITE_SKIP_UTF8(z);

  30144.     r++;

  30145.   }

  30146.   return r;

  30147. }

  30148. 

  30149. /* This test function is not currently used by the automated test-suite. 

  30150. ** Hence it is only available in debug builds.

  30151. */

  30152. #if defined(SQLITE_TEST) && defined(SQLITE_DEBUG)

  30153. /*

  30154. ** Translate UTF-8 to UTF-8.

  30155. **

  30156. ** This has the effect of making sure that the string is well-formed

  30157. ** UTF-8.  Miscoded characters are removed.

  30158. **

  30159. ** The translation is done in-place and aborted if the output

  30160. ** overruns the input.

  30161. */

  30162. SQLITE_PRIVATE int sqlite3Utf8To8(unsigned char *zIn){

  30163.   unsigned char *zOut = zIn;

  30164.   unsigned char *zStart = zIn;

  30165.   u32 c;

  30166. 

  30167.   while( zIn[0] && zOut<=zIn ){

  30168.     c = sqlite3Utf8Read((const u8**)&zIn);

  30169.     if( c!=0xfffd ){

  30170.       WRITE_UTF8(zOut, c);

  30171.     }

  30172.   }

  30173.   *zOut = 0;

  30174.   return (int)(zOut - zStart);

  30175. }

  30176. #endif

  30177. 

  30178. #ifndef SQLITE_OMIT_UTF16

  30179. /*

  30180. ** Convert a UTF-16 string in the native encoding into a UTF-8 string.

  30181. ** Memory to hold the UTF-8 string is obtained from sqlite3_malloc and must

  30182. ** be freed by the calling function.

  30183. **

  30184. ** NULL is returned if there is an allocation error.

  30185. */

  30186. SQLITE_PRIVATE char *sqlite3Utf16to8(sqlite3 *db, const void *z, int nByte, u8 enc){

  30187.   Mem m;

  30188.   memset(&m, 0, sizeof(m));

  30189.   m.db = db;

  30190.   sqlite3VdbeMemSetStr(&m, z, nByte, enc, SQLITE_STATIC);

  30191.   sqlite3VdbeChangeEncoding(&m, SQLITE_UTF8);

  30192.   if( db->mallocFailed ){

  30193.     sqlite3VdbeMemRelease(&m);

  30194.     m.z = 0;

  30195.   }

  30196.   assert( (m.flags & MEM_Term)!=0 || db->mallocFailed );

  30197.   assert( (m.flags & MEM_Str)!=0 || db->mallocFailed );

  30198.   assert( m.z || db->mallocFailed );

  30199.   return m.z;

  30200. }

  30201. 

  30202. /*

  30203. ** zIn is a UTF-16 encoded unicode string at least nChar characters long.

  30204. ** Return the number of bytes in the first nChar unicode characters

  30205. ** in pZ.  nChar must be non-negative.

  30206. */

  30207. SQLITE_PRIVATE int sqlite3Utf16ByteLen(const void *zIn, int nChar){

  30208.   int c;

  30209.   unsigned char const *z = zIn;

  30210.   int n = 0;

  30211.   

  30212.   if( SQLITE_UTF16NATIVE==SQLITE_UTF16BE ){

  30213.     while( n<nChar ){

  30214.       READ_UTF16BE(z, 1, c);

  30215.       n++;

  30216.     }

  30217.   }else{

  30218.     while( n<nChar ){

  30219.       READ_UTF16LE(z, 1, c);

  30220.       n++;

  30221.     }

  30222.   }

  30223.   return (int)(z-(unsigned char const *)zIn);

  30224. }

  30225. 

  30226. #if defined(SQLITE_TEST)

  30227. /*

  30228. ** This routine is called from the TCL test function "translate_selftest".

  30229. ** It checks that the primitives for serializing and deserializing

  30230. ** characters in each encoding are inverses of each other.

  30231. */

  30232. SQLITE_PRIVATE void sqlite3UtfSelfTest(void){

  30233.   unsigned int i, t;

  30234.   unsigned char zBuf[20];

  30235.   unsigned char *z;

  30236.   int n;

  30237.   unsigned int c;

  30238. 

  30239.   for(i=0; i<0x00110000; i++){

  30240.     z = zBuf;

  30241.     WRITE_UTF8(z, i);

  30242.     n = (int)(z-zBuf);

  30243.     assert( n>0 && n<=4 );

  30244.     z[0] = 0;

  30245.     z = zBuf;

  30246.     c = sqlite3Utf8Read((const u8**)&z);

  30247.     t = i;

  30248.     if( i>=0xD800 && i<=0xDFFF ) t = 0xFFFD;

  30249.     if( (i&0xFFFFFFFE)==0xFFFE ) t = 0xFFFD;

  30250.     assert( c==t );

  30251.     assert( (z-zBuf)==n );

  30252.   }

  30253.   for(i=0; i<0x00110000; i++){

  30254.     if( i>=0xD800 && i<0xE000 ) continue;

  30255.     z = zBuf;

  30256.     WRITE_UTF16LE(z, i);

  30257.     n = (int)(z-zBuf);

  30258.     assert( n>0 && n<=4 );

  30259.     z[0] = 0;

  30260.     z = zBuf;

  30261.     READ_UTF16LE(z, 1, c);

  30262.     assert( c==i );

  30263.     assert( (z-zBuf)==n );

  30264.   }

  30265.   for(i=0; i<0x00110000; i++){

  30266.     if( i>=0xD800 && i<0xE000 ) continue;

  30267.     z = zBuf;

  30268.     WRITE_UTF16BE(z, i);

  30269.     n = (int)(z-zBuf);

  30270.     assert( n>0 && n<=4 );

  30271.     z[0] = 0;

  30272.     z = zBuf;

  30273.     READ_UTF16BE(z, 1, c);

  30274.     assert( c==i );

  30275.     assert( (z-zBuf)==n );

  30276.   }

  30277. }

  30278. #endif /* SQLITE_TEST */

  30279. #endif /* SQLITE_OMIT_UTF16 */

  30280. 

  30281. /************** End of utf.c *************************************************/

  30282. /************** Begin file util.c ********************************************/

  30283. /*

  30284. ** 2001 September 15

  30285. **

  30286. ** The author disclaims copyright to this source code.  In place of

  30287. ** a legal notice, here is a blessing:

  30288. **

  30289. **    May you do good and not evil.

  30290. **    May you find forgiveness for yourself and forgive others.

  30291. **    May you share freely, never taking more than you give.

  30292. **

  30293. *************************************************************************

  30294. ** Utility functions used throughout sqlite.

  30295. **

  30296. ** This file contains functions for allocating memory, comparing

  30297. ** strings, and stuff like that.

  30298. **

  30299. */

  30300. /* #include "sqliteInt.h" */

  30301. /* #include <stdarg.h> */

  30302. #include <math.h>

  30303. 

  30304. /*

  30305. ** Routine needed to support the testcase() macro.

  30306. */

  30307. #ifdef SQLITE_COVERAGE_TEST

  30308. SQLITE_PRIVATE void sqlite3Coverage(int x){

  30309.   static unsigned dummy = 0;

  30310.   dummy += (unsigned)x;

  30311. }

  30312. #endif

  30313. 

  30314. /*

  30315. ** Calls to sqlite3FaultSim() are used to simulate a failure during testing,

  30316. ** or to bypass normal error detection during testing in order to let 

  30317. ** execute proceed futher downstream.

  30318. **

  30319. ** In deployment, sqlite3FaultSim() *always* return SQLITE_OK (0).  The

  30320. ** sqlite3FaultSim() function only returns non-zero during testing.

  30321. **

  30322. ** During testing, if the test harness has set a fault-sim callback using

  30323. ** a call to sqlite3_test_control(SQLITE_TESTCTRL_FAULT_INSTALL), then

  30324. ** each call to sqlite3FaultSim() is relayed to that application-supplied

  30325. ** callback and the integer return value form the application-supplied

  30326. ** callback is returned by sqlite3FaultSim().

  30327. **

  30328. ** The integer argument to sqlite3FaultSim() is a code to identify which

  30329. ** sqlite3FaultSim() instance is being invoked. Each call to sqlite3FaultSim()

  30330. ** should have a unique code.  To prevent legacy testing applications from

  30331. ** breaking, the codes should not be changed or reused.

  30332. */

  30333. #ifndef SQLITE_UNTESTABLE

  30334. SQLITE_PRIVATE int sqlite3FaultSim(int iTest){

  30335.   int (*xCallback)(int) = sqlite3GlobalConfig.xTestCallback;

  30336.   return xCallback ? xCallback(iTest) : SQLITE_OK;

  30337. }

  30338. #endif

  30339. 

  30340. #ifndef SQLITE_OMIT_FLOATING_POINT

  30341. /*

  30342. ** Return true if the floating point value is Not a Number (NaN).

  30343. */

  30344. SQLITE_PRIVATE int sqlite3IsNaN(double x){

  30345.   u64 y;

  30346.   memcpy(&y,&x,sizeof(y));

  30347.   return IsNaN(y);

  30348. }

  30349. #endif /* SQLITE_OMIT_FLOATING_POINT */

  30350. 

  30351. /*

  30352. ** Compute a string length that is limited to what can be stored in

  30353. ** lower 30 bits of a 32-bit signed integer.

  30354. **

  30355. ** The value returned will never be negative.  Nor will it ever be greater

  30356. ** than the actual length of the string.  For very long strings (greater

  30357. ** than 1GiB) the value returned might be less than the true string length.

  30358. */

  30359. SQLITE_PRIVATE int sqlite3Strlen30(const char *z){

  30360.   if( z==0 ) return 0;

  30361.   return 0x3fffffff & (int)strlen(z);

  30362. }

  30363. 

  30364. /*

  30365. ** Return the declared type of a column.  Or return zDflt if the column 

  30366. ** has no declared type.

  30367. **

  30368. ** The column type is an extra string stored after the zero-terminator on

  30369. ** the column name if and only if the COLFLAG_HASTYPE flag is set.

  30370. */

  30371. SQLITE_PRIVATE char *sqlite3ColumnType(Column *pCol, char *zDflt){

  30372.   if( (pCol->colFlags & COLFLAG_HASTYPE)==0 ) return zDflt;

  30373.   return pCol->zName + strlen(pCol->zName) + 1;

  30374. }

  30375. 

  30376. /*

  30377. ** Helper function for sqlite3Error() - called rarely.  Broken out into

  30378. ** a separate routine to avoid unnecessary register saves on entry to

  30379. ** sqlite3Error().

  30380. */

  30381. static SQLITE_NOINLINE void  sqlite3ErrorFinish(sqlite3 *db, int err_code){

  30382.   if( db->pErr ) sqlite3ValueSetNull(db->pErr);

  30383.   sqlite3SystemError(db, err_code);

  30384. }

  30385. 

  30386. /*

  30387. ** Set the current error code to err_code and clear any prior error message.

  30388. ** Also set iSysErrno (by calling sqlite3System) if the err_code indicates

  30389. ** that would be appropriate.

  30390. */

  30391. SQLITE_PRIVATE void sqlite3Error(sqlite3 *db, int err_code){

  30392.   assert( db!=0 );

  30393.   db->errCode = err_code;

  30394.   if( err_code || db->pErr ) sqlite3ErrorFinish(db, err_code);

  30395. }

  30396. 

  30397. /*

  30398. ** Load the sqlite3.iSysErrno field if that is an appropriate thing

  30399. ** to do based on the SQLite error code in rc.

  30400. */

  30401. SQLITE_PRIVATE void sqlite3SystemError(sqlite3 *db, int rc){

  30402.   if( rc==SQLITE_IOERR_NOMEM ) return;

  30403.   rc &= 0xff;

  30404.   if( rc==SQLITE_CANTOPEN || rc==SQLITE_IOERR ){

  30405.     db->iSysErrno = sqlite3OsGetLastError(db->pVfs);

  30406.   }

  30407. }

  30408. 

  30409. /*

  30410. ** Set the most recent error code and error string for the sqlite

  30411. ** handle "db". The error code is set to "err_code".

  30412. **

  30413. ** If it is not NULL, string zFormat specifies the format of the

  30414. ** error string in the style of the printf functions: The following

  30415. ** format characters are allowed:

  30416. **

  30417. **      %s      Insert a string

  30418. **      %z      A string that should be freed after use

  30419. **      %d      Insert an integer

  30420. **      %T      Insert a token

  30421. **      %S      Insert the first element of a SrcList

  30422. **

  30423. ** zFormat and any string tokens that follow it are assumed to be

  30424. ** encoded in UTF-8.

  30425. **

  30426. ** To clear the most recent error for sqlite handle "db", sqlite3Error

  30427. ** should be called with err_code set to SQLITE_OK and zFormat set

  30428. ** to NULL.

  30429. */

  30430. SQLITE_PRIVATE void sqlite3ErrorWithMsg(sqlite3 *db, int err_code, const char *zFormat, ...){

  30431.   assert( db!=0 );

  30432.   db->errCode = err_code;

  30433.   sqlite3SystemError(db, err_code);

  30434.   if( zFormat==0 ){

  30435.     sqlite3Error(db, err_code);

  30436.   }else if( db->pErr || (db->pErr = sqlite3ValueNew(db))!=0 ){

  30437.     char *z;

  30438.     va_list ap;

  30439.     va_start(ap, zFormat);

  30440.     z = sqlite3VMPrintf(db, zFormat, ap);

  30441.     va_end(ap);

  30442.     sqlite3ValueSetStr(db->pErr, -1, z, SQLITE_UTF8, SQLITE_DYNAMIC);

  30443.   }

  30444. }

  30445. 

  30446. /*

  30447. ** Add an error message to pParse->zErrMsg and increment pParse->nErr.

  30448. ** The following formatting characters are allowed:

  30449. **

  30450. **      %s      Insert a string

  30451. **      %z      A string that should be freed after use

  30452. **      %d      Insert an integer

  30453. **      %T      Insert a token

  30454. **      %S      Insert the first element of a SrcList

  30455. **

  30456. ** This function should be used to report any error that occurs while

  30457. ** compiling an SQL statement (i.e. within sqlite3_prepare()). The

  30458. ** last thing the sqlite3_prepare() function does is copy the error

  30459. ** stored by this function into the database handle using sqlite3Error().

  30460. ** Functions sqlite3Error() or sqlite3ErrorWithMsg() should be used

  30461. ** during statement execution (sqlite3_step() etc.).

  30462. */

  30463. SQLITE_PRIVATE void sqlite3ErrorMsg(Parse *pParse, const char *zFormat, ...){

  30464.   char *zMsg;

  30465.   va_list ap;

  30466.   sqlite3 *db = pParse->db;

  30467.   va_start(ap, zFormat);

  30468.   zMsg = sqlite3VMPrintf(db, zFormat, ap);

  30469.   va_end(ap);

  30470.   if( db->suppressErr ){

  30471.     sqlite3DbFree(db, zMsg);

  30472.   }else{

  30473.     pParse->nErr++;

  30474.     sqlite3DbFree(db, pParse->zErrMsg);

  30475.     pParse->zErrMsg = zMsg;

  30476.     pParse->rc = SQLITE_ERROR;

  30477.   }

  30478. }

  30479. 

  30480. /*

  30481. ** If database connection db is currently parsing SQL, then transfer

  30482. ** error code errCode to that parser if the parser has not already

  30483. ** encountered some other kind of error.

  30484. */

  30485. SQLITE_PRIVATE int sqlite3ErrorToParser(sqlite3 *db, int errCode){

  30486.   Parse *pParse;

  30487.   if( db==0 || (pParse = db->pParse)==0 ) return errCode;

  30488.   pParse->rc = errCode;

  30489.   pParse->nErr++;

  30490.   return errCode;

  30491. }

  30492. 

  30493. /*

  30494. ** Convert an SQL-style quoted string into a normal string by removing

  30495. ** the quote characters.  The conversion is done in-place.  If the

  30496. ** input does not begin with a quote character, then this routine

  30497. ** is a no-op.

  30498. **

  30499. ** The input string must be zero-terminated.  A new zero-terminator

  30500. ** is added to the dequoted string.

  30501. **

  30502. ** The return value is -1 if no dequoting occurs or the length of the

  30503. ** dequoted string, exclusive of the zero terminator, if dequoting does

  30504. ** occur.

  30505. **

  30506. ** 2002-02-14: This routine is extended to remove MS-Access style

  30507. ** brackets from around identifiers.  For example:  "[a-b-c]" becomes

  30508. ** "a-b-c".

  30509. */

  30510. SQLITE_PRIVATE void sqlite3Dequote(char *z){

  30511.   char quote;

  30512.   int i, j;

  30513.   if( z==0 ) return;

  30514.   quote = z[0];

  30515.   if( !sqlite3Isquote(quote) ) return;

  30516.   if( quote=='[' ) quote = ']';

  30517.   for(i=1, j=0;; i++){

  30518.     assert( z[i] );

  30519.     if( z[i]==quote ){

  30520.       if( z[i+1]==quote ){

  30521.         z[j++] = quote;

  30522.         i++;

  30523.       }else{

  30524.         break;

  30525.       }

  30526.     }else{

  30527.       z[j++] = z[i];

  30528.     }

  30529.   }

  30530.   z[j] = 0;

  30531. }

  30532. SQLITE_PRIVATE void sqlite3DequoteExpr(Expr *p){

  30533.   assert( sqlite3Isquote(p->u.zToken[0]) );

  30534.   p->flags |= p->u.zToken[0]=='"' ? EP_Quoted|EP_DblQuoted : EP_Quoted;

  30535.   sqlite3Dequote(p->u.zToken);

  30536. }

  30537. 

  30538. /*

  30539. ** Generate a Token object from a string

  30540. */

  30541. SQLITE_PRIVATE void sqlite3TokenInit(Token *p, char *z){

  30542.   p->z = z;

  30543.   p->n = sqlite3Strlen30(z);

  30544. }

  30545. 

  30546. /* Convenient short-hand */

  30547. #define UpperToLower sqlite3UpperToLower

  30548. 

  30549. /*

  30550. ** Some systems have stricmp().  Others have strcasecmp().  Because

  30551. ** there is no consistency, we will define our own.

  30552. **

  30553. ** IMPLEMENTATION-OF: R-30243-02494 The sqlite3_stricmp() and

  30554. ** sqlite3_strnicmp() APIs allow applications and extensions to compare

  30555. ** the contents of two buffers containing UTF-8 strings in a

  30556. ** case-independent fashion, using the same definition of "case

  30557. ** independence" that SQLite uses internally when comparing identifiers.

  30558. */

  30559. SQLITE_API int sqlite3_stricmp(const char *zLeft, const char *zRight){

  30560.   if( zLeft==0 ){

  30561.     return zRight ? -1 : 0;

  30562.   }else if( zRight==0 ){

  30563.     return 1;

  30564.   }

  30565.   return sqlite3StrICmp(zLeft, zRight);

  30566. }

  30567. SQLITE_PRIVATE int sqlite3StrICmp(const char *zLeft, const char *zRight){

  30568.   unsigned char *a, *b;

  30569.   int c, x;

  30570.   a = (unsigned char *)zLeft;

  30571.   b = (unsigned char *)zRight;

  30572.   for(;;){

  30573.     c = *a;

  30574.     x = *b;

  30575.     if( c==x ){

  30576.       if( c==0 ) break;

  30577.     }else{

  30578.       c = (int)UpperToLower[c] - (int)UpperToLower[x];

  30579.       if( c ) break;

  30580.     }

  30581.     a++;

  30582.     b++;

  30583.   }

  30584.   return c;

  30585. }

  30586. SQLITE_API int sqlite3_strnicmp(const char *zLeft, const char *zRight, int N){

  30587.   register unsigned char *a, *b;

  30588.   if( zLeft==0 ){

  30589.     return zRight ? -1 : 0;

  30590.   }else if( zRight==0 ){

  30591.     return 1;

  30592.   }

  30593.   a = (unsigned char *)zLeft;

  30594.   b = (unsigned char *)zRight;

  30595.   while( N-- > 0 && *a!=0 && UpperToLower[*a]==UpperToLower[*b]){ a++; b++; }

  30596.   return N<0 ? 0 : UpperToLower[*a] - UpperToLower[*b];

  30597. }

  30598. 

  30599. /*

  30600. ** Compute 10 to the E-th power.  Examples:  E==1 results in 10.

  30601. ** E==2 results in 100.  E==50 results in 1.0e50.

  30602. **

  30603. ** This routine only works for values of E between 1 and 341.

  30604. */

  30605. static LONGDOUBLE_TYPE sqlite3Pow10(int E){

  30606. #if defined(_MSC_VER)

  30607.   static const LONGDOUBLE_TYPE x[] = {

  30608.     1.0e+001L,

  30609.     1.0e+002L,

  30610.     1.0e+004L,

  30611.     1.0e+008L,

  30612.     1.0e+016L,

  30613.     1.0e+032L,

  30614.     1.0e+064L,

  30615.     1.0e+128L,

  30616.     1.0e+256L

  30617.   };

  30618.   LONGDOUBLE_TYPE r = 1.0;

  30619.   int i;

  30620.   assert( E>=0 && E<=307 );

  30621.   for(i=0; E!=0; i++, E >>=1){

  30622.     if( E & 1 ) r *= x[i];

  30623.   }

  30624.   return r;

  30625. #else

  30626.   LONGDOUBLE_TYPE x = 10.0;

  30627.   LONGDOUBLE_TYPE r = 1.0;

  30628.   while(1){

  30629.     if( E & 1 ) r *= x;

  30630.     E >>= 1;

  30631.     if( E==0 ) break;

  30632.     x *= x;

  30633.   }

  30634.   return r; 

  30635. #endif

  30636. }

  30637. 

  30638. /*

  30639. ** The string z[] is an text representation of a real number.

  30640. ** Convert this string to a double and write it into *pResult.

  30641. **

  30642. ** The string z[] is length bytes in length (bytes, not characters) and

  30643. ** uses the encoding enc.  The string is not necessarily zero-terminated.

  30644. **

  30645. ** Return TRUE if the result is a valid real number (or integer) and FALSE

  30646. ** if the string is empty or contains extraneous text.  More specifically

  30647. ** return

  30648. **      1          =>  The input string is a pure integer

  30649. **      2 or more  =>  The input has a decimal point or eNNN clause

  30650. **      0 or less  =>  The input string is not a valid number

  30651. **     -1          =>  Not a valid number, but has a valid prefix which 

  30652. **                     includes a decimal point and/or an eNNN clause

  30653. **

  30654. ** Valid numbers are in one of these formats:

  30655. **

  30656. **    [+-]digits[E[+-]digits]

  30657. **    [+-]digits.[digits][E[+-]digits]

  30658. **    [+-].digits[E[+-]digits]

  30659. **

  30660. ** Leading and trailing whitespace is ignored for the purpose of determining

  30661. ** validity.

  30662. **

  30663. ** If some prefix of the input string is a valid number, this routine

  30664. ** returns FALSE but it still converts the prefix and writes the result

  30665. ** into *pResult.

  30666. */

  30667. SQLITE_PRIVATE int sqlite3AtoF(const char *z, double *pResult, int length, u8 enc){

  30668. #ifndef SQLITE_OMIT_FLOATING_POINT

  30669.   int incr;

  30670.   const char *zEnd = z + length;

  30671.   /* sign * significand * (10 ^ (esign * exponent)) */

  30672.   int sign = 1;    /* sign of significand */

  30673.   i64 s = 0;       /* significand */

  30674.   int d = 0;       /* adjust exponent for shifting decimal point */

  30675.   int esign = 1;   /* sign of exponent */

  30676.   int e = 0;       /* exponent */

  30677.   int eValid = 1;  /* True exponent is either not used or is well-formed */

  30678.   double result;

  30679.   int nDigit = 0;  /* Number of digits processed */

  30680.   int eType = 1;   /* 1: pure integer,  2+: fractional  -1 or less: bad UTF16 */

  30681. 

  30682.   assert( enc==SQLITE_UTF8 || enc==SQLITE_UTF16LE || enc==SQLITE_UTF16BE );

  30683.   *pResult = 0.0;   /* Default return value, in case of an error */

  30684. 

  30685.   if( enc==SQLITE_UTF8 ){

  30686.     incr = 1;

  30687.   }else{

  30688.     int i;

  30689.     incr = 2;

  30690.     assert( SQLITE_UTF16LE==2 && SQLITE_UTF16BE==3 );

  30691.     testcase( enc==SQLITE_UTF16LE );

  30692.     testcase( enc==SQLITE_UTF16BE );

  30693.     for(i=3-enc; i<length && z[i]==0; i+=2){}

  30694.     if( i<length ) eType = -100;

  30695.     zEnd = &z[i^1];

  30696.     z += (enc&1);

  30697.   }

  30698. 

  30699.   /* skip leading spaces */

  30700.   while( z<zEnd && sqlite3Isspace(*z) ) z+=incr;

  30701.   if( z>=zEnd ) return 0;

  30702. 

  30703.   /* get sign of significand */

  30704.   if( *z=='-' ){

  30705.     sign = -1;

  30706.     z+=incr;

  30707.   }else if( *z=='+' ){

  30708.     z+=incr;

  30709.   }

  30710. 

  30711.   /* copy max significant digits to significand */

  30712.   while( z<zEnd && sqlite3Isdigit(*z) ){

  30713.     s = s*10 + (*z - '0');

  30714.     z+=incr; nDigit++;

  30715.     if( s>=((LARGEST_INT64-9)/10) ){

  30716.       /* skip non-significant significand digits

  30717.       ** (increase exponent by d to shift decimal left) */

  30718.       while( z<zEnd && sqlite3Isdigit(*z) ){ z+=incr; d++; }

  30719.     }

  30720.   }

  30721.   if( z>=zEnd ) goto do_atof_calc;

  30722. 

  30723.   /* if decimal point is present */

  30724.   if( *z=='.' ){

  30725.     z+=incr;

  30726.     eType++;

  30727.     /* copy digits from after decimal to significand

  30728.     ** (decrease exponent by d to shift decimal right) */

  30729.     while( z<zEnd && sqlite3Isdigit(*z) ){

  30730.       if( s<((LARGEST_INT64-9)/10) ){

  30731.         s = s*10 + (*z - '0');

  30732.         d--;

  30733.         nDigit++;

  30734.       }

  30735.       z+=incr;

  30736.     }

  30737.   }

  30738.   if( z>=zEnd ) goto do_atof_calc;

  30739. 

  30740.   /* if exponent is present */

  30741.   if( *z=='e' || *z=='E' ){

  30742.     z+=incr;

  30743.     eValid = 0;

  30744.     eType++;

  30745. 

  30746.     /* This branch is needed to avoid a (harmless) buffer overread.  The 

  30747.     ** special comment alerts the mutation tester that the correct answer

  30748.     ** is obtained even if the branch is omitted */

  30749.     if( z>=zEnd ) goto do_atof_calc;              /*PREVENTS-HARMLESS-OVERREAD*/

  30750. 

  30751.     /* get sign of exponent */

  30752.     if( *z=='-' ){

  30753.       esign = -1;

  30754.       z+=incr;

  30755.     }else if( *z=='+' ){

  30756.       z+=incr;

  30757.     }

  30758.     /* copy digits to exponent */

  30759.     while( z<zEnd && sqlite3Isdigit(*z) ){

  30760.       e = e<10000 ? (e*10 + (*z - '0')) : 10000;

  30761.       z+=incr;

  30762.       eValid = 1;

  30763.     }

  30764.   }

  30765. 

  30766.   /* skip trailing spaces */

  30767.   while( z<zEnd && sqlite3Isspace(*z) ) z+=incr;

  30768. 

  30769. do_atof_calc:

  30770.   /* adjust exponent by d, and update sign */

  30771.   e = (e*esign) + d;

  30772.   if( e<0 ) {

  30773.     esign = -1;

  30774.     e *= -1;

  30775.   } else {

  30776.     esign = 1;

  30777.   }

  30778. 

  30779.   if( s==0 ) {

  30780.     /* In the IEEE 754 standard, zero is signed. */

  30781.     result = sign<0 ? -(double)0 : (double)0;

  30782.   } else {

  30783.     /* Attempt to reduce exponent.

  30784.     **

  30785.     ** Branches that are not required for the correct answer but which only

  30786.     ** help to obtain the correct answer faster are marked with special

  30787.     ** comments, as a hint to the mutation tester.

  30788.     */

  30789.     while( e>0 ){                                       /*OPTIMIZATION-IF-TRUE*/

  30790.       if( esign>0 ){

  30791.         if( s>=(LARGEST_INT64/10) ) break;             /*OPTIMIZATION-IF-FALSE*/

  30792.         s *= 10;

  30793.       }else{

  30794.         if( s%10!=0 ) break;                           /*OPTIMIZATION-IF-FALSE*/

  30795.         s /= 10;

  30796.       }

  30797.       e--;

  30798.     }

  30799. 

  30800.     /* adjust the sign of significand */

  30801.     s = sign<0 ? -s : s;

  30802. 

  30803.     if( e==0 ){                                         /*OPTIMIZATION-IF-TRUE*/

  30804.       result = (double)s;

  30805.     }else{

  30806.       /* attempt to handle extremely small/large numbers better */

  30807.       if( e>307 ){                                      /*OPTIMIZATION-IF-TRUE*/

  30808.         if( e<342 ){                                    /*OPTIMIZATION-IF-TRUE*/

  30809.           LONGDOUBLE_TYPE scale = sqlite3Pow10(e-308);

  30810.           if( esign<0 ){

  30811.             result = s / scale;

  30812.             result /= 1.0e+308;

  30813.           }else{

  30814.             result = s * scale;

  30815.             result *= 1.0e+308;

  30816.           }

  30817.         }else{ assert( e>=342 );

  30818.           if( esign<0 ){

  30819.             result = 0.0*s;

  30820.           }else{

  30821. #ifdef INFINITY

  30822.             result = INFINITY*s;

  30823. #else

  30824.             result = 1e308*1e308*s;  /* Infinity */

  30825. #endif

  30826.           }

  30827.         }

  30828.       }else{

  30829.         LONGDOUBLE_TYPE scale = sqlite3Pow10(e);

  30830.         if( esign<0 ){

  30831.           result = s / scale;

  30832.         }else{

  30833.           result = s * scale;

  30834.         }

  30835.       }

  30836.     }

  30837.   }

  30838. 

  30839.   /* store the result */

  30840.   *pResult = result;

  30841. 

  30842.   /* return true if number and no extra non-whitespace chracters after */

  30843.   if( z==zEnd && nDigit>0 && eValid && eType>0 ){

  30844.     return eType;

  30845.   }else if( eType>=2 && (eType==3 || eValid) && nDigit>0 ){

  30846.     return -1;

  30847.   }else{

  30848.     return 0;

  30849.   }

  30850. #else

  30851.   return !sqlite3Atoi64(z, pResult, length, enc);

  30852. #endif /* SQLITE_OMIT_FLOATING_POINT */

  30853. }

  30854. 

  30855. /*

  30856. ** Compare the 19-character string zNum against the text representation

  30857. ** value 2^63:  9223372036854775808.  Return negative, zero, or positive

  30858. ** if zNum is less than, equal to, or greater than the string.

  30859. ** Note that zNum must contain exactly 19 characters.

  30860. **

  30861. ** Unlike memcmp() this routine is guaranteed to return the difference

  30862. ** in the values of the last digit if the only difference is in the

  30863. ** last digit.  So, for example,

  30864. **

  30865. **      compare2pow63("9223372036854775800", 1)

  30866. **

  30867. ** will return -8.

  30868. */

  30869. static int compare2pow63(const char *zNum, int incr){

  30870.   int c = 0;

  30871.   int i;

  30872.                     /* 012345678901234567 */

  30873.   const char *pow63 = "922337203685477580";

  30874.   for(i=0; c==0 && i<18; i++){

  30875.     c = (zNum[i*incr]-pow63[i])*10;

  30876.   }

  30877.   if( c==0 ){

  30878.     c = zNum[18*incr] - '8';

  30879.     testcase( c==(-1) );

  30880.     testcase( c==0 );

  30881.     testcase( c==(+1) );

  30882.   }

  30883.   return c;

  30884. }

  30885. 

  30886. /*

  30887. ** Convert zNum to a 64-bit signed integer.  zNum must be decimal. This

  30888. ** routine does *not* accept hexadecimal notation.

  30889. **

  30890. ** Returns:

  30891. **

  30892. **    -1    Not even a prefix of the input text looks like an integer

  30893. **     0    Successful transformation.  Fits in a 64-bit signed integer.

  30894. **     1    Excess non-space text after the integer value

  30895. **     2    Integer too large for a 64-bit signed integer or is malformed

  30896. **     3    Special case of 9223372036854775808

  30897. **

  30898. ** length is the number of bytes in the string (bytes, not characters).

  30899. ** The string is not necessarily zero-terminated.  The encoding is

  30900. ** given by enc.

  30901. */

  30902. SQLITE_PRIVATE int sqlite3Atoi64(const char *zNum, i64 *pNum, int length, u8 enc){

  30903.   int incr;

  30904.   u64 u = 0;

  30905.   int neg = 0; /* assume positive */

  30906.   int i;

  30907.   int c = 0;

  30908.   int nonNum = 0;  /* True if input contains UTF16 with high byte non-zero */

  30909.   int rc;          /* Baseline return code */

  30910.   const char *zStart;

  30911.   const char *zEnd = zNum + length;

  30912.   assert( enc==SQLITE_UTF8 || enc==SQLITE_UTF16LE || enc==SQLITE_UTF16BE );

  30913.   if( enc==SQLITE_UTF8 ){

  30914.     incr = 1;

  30915.   }else{

  30916.     incr = 2;

  30917.     assert( SQLITE_UTF16LE==2 && SQLITE_UTF16BE==3 );

  30918.     for(i=3-enc; i<length && zNum[i]==0; i+=2){}

  30919.     nonNum = i<length;

  30920.     zEnd = &zNum[i^1];

  30921.     zNum += (enc&1);

  30922.   }

  30923.   while( zNum<zEnd && sqlite3Isspace(*zNum) ) zNum+=incr;

  30924.   if( zNum<zEnd ){

  30925.     if( *zNum=='-' ){

  30926.       neg = 1;

  30927.       zNum+=incr;

  30928.     }else if( *zNum=='+' ){

  30929.       zNum+=incr;

  30930.     }

  30931.   }

  30932.   zStart = zNum;

  30933.   while( zNum<zEnd && zNum[0]=='0' ){ zNum+=incr; } /* Skip leading zeros. */

  30934.   for(i=0; &zNum[i]<zEnd && (c=zNum[i])>='0' && c<='9'; i+=incr){

  30935.     u = u*10 + c - '0';

  30936.   }

  30937.   testcase( i==18*incr );

  30938.   testcase( i==19*incr );

  30939.   testcase( i==20*incr );

  30940.   if( u>LARGEST_INT64 ){

  30941.     /* This test and assignment is needed only to suppress UB warnings

  30942.     ** from clang and -fsanitize=undefined.  This test and assignment make

  30943.     ** the code a little larger and slower, and no harm comes from omitting

  30944.     ** them, but we must appaise the undefined-behavior pharisees. */

  30945.     *pNum = neg ? SMALLEST_INT64 : LARGEST_INT64;

  30946.   }else if( neg ){

  30947.     *pNum = -(i64)u;

  30948.   }else{

  30949.     *pNum = (i64)u;

  30950.   }

  30951.   rc = 0;

  30952.   if( i==0 && zStart==zNum ){    /* No digits */

  30953.     rc = -1;

  30954.   }else if( nonNum ){            /* UTF16 with high-order bytes non-zero */

  30955.     rc = 1;

  30956.   }else if( &zNum[i]<zEnd ){     /* Extra bytes at the end */

  30957.     int jj = i;

  30958.     do{

  30959.       if( !sqlite3Isspace(zNum[jj]) ){

  30960.         rc = 1;          /* Extra non-space text after the integer */

  30961.         break;

  30962.       }

  30963.       jj += incr;

  30964.     }while( &zNum[jj]<zEnd );

  30965.   }

  30966.   if( i<19*incr ){

  30967.     /* Less than 19 digits, so we know that it fits in 64 bits */

  30968.     assert( u<=LARGEST_INT64 );

  30969.     return rc;

  30970.   }else{

  30971.     /* zNum is a 19-digit numbers.  Compare it against 9223372036854775808. */

  30972.     c = i>19*incr ? 1 : compare2pow63(zNum, incr);

  30973.     if( c<0 ){

  30974.       /* zNum is less than 9223372036854775808 so it fits */

  30975.       assert( u<=LARGEST_INT64 );

  30976.       return rc;

  30977.     }else{

  30978.       *pNum = neg ? SMALLEST_INT64 : LARGEST_INT64;

  30979.       if( c>0 ){

  30980.         /* zNum is greater than 9223372036854775808 so it overflows */

  30981.         return 2;

  30982.       }else{

  30983.         /* zNum is exactly 9223372036854775808.  Fits if negative.  The

  30984.         ** special case 2 overflow if positive */

  30985.         assert( u-1==LARGEST_INT64 );

  30986.         return neg ? rc : 3;

  30987.       }

  30988.     }

  30989.   }

  30990. }

  30991. 

  30992. /*

  30993. ** Transform a UTF-8 integer literal, in either decimal or hexadecimal,

  30994. ** into a 64-bit signed integer.  This routine accepts hexadecimal literals,

  30995. ** whereas sqlite3Atoi64() does not.

  30996. **

  30997. ** Returns:

  30998. **

  30999. **     0    Successful transformation.  Fits in a 64-bit signed integer.

  31000. **     1    Excess text after the integer value

  31001. **     2    Integer too large for a 64-bit signed integer or is malformed

  31002. **     3    Special case of 9223372036854775808

  31003. */

  31004. SQLITE_PRIVATE int sqlite3DecOrHexToI64(const char *z, i64 *pOut){

  31005. #ifndef SQLITE_OMIT_HEX_INTEGER

  31006.   if( z[0]=='0'

  31007.    && (z[1]=='x' || z[1]=='X')

  31008.   ){

  31009.     u64 u = 0;

  31010.     int i, k;

  31011.     for(i=2; z[i]=='0'; i++){}

  31012.     for(k=i; sqlite3Isxdigit(z[k]); k++){

  31013.       u = u*16 + sqlite3HexToInt(z[k]);

  31014.     }

  31015.     memcpy(pOut, &u, 8);

  31016.     return (z[k]==0 && k-i<=16) ? 0 : 2;

  31017.   }else

  31018. #endif /* SQLITE_OMIT_HEX_INTEGER */

  31019.   {

  31020.     return sqlite3Atoi64(z, pOut, sqlite3Strlen30(z), SQLITE_UTF8);

  31021.   }

  31022. }

  31023. 

  31024. /*

  31025. ** If zNum represents an integer that will fit in 32-bits, then set

  31026. ** *pValue to that integer and return true.  Otherwise return false.

  31027. **

  31028. ** This routine accepts both decimal and hexadecimal notation for integers.

  31029. **

  31030. ** Any non-numeric characters that following zNum are ignored.

  31031. ** This is different from sqlite3Atoi64() which requires the

  31032. ** input number to be zero-terminated.

  31033. */

  31034. SQLITE_PRIVATE int sqlite3GetInt32(const char *zNum, int *pValue){

  31035.   sqlite_int64 v = 0;

  31036.   int i, c;

  31037.   int neg = 0;

  31038.   if( zNum[0]=='-' ){

  31039.     neg = 1;

  31040.     zNum++;

  31041.   }else if( zNum[0]=='+' ){

  31042.     zNum++;

  31043.   }

  31044. #ifndef SQLITE_OMIT_HEX_INTEGER

  31045.   else if( zNum[0]=='0'

  31046.         && (zNum[1]=='x' || zNum[1]=='X')

  31047.         && sqlite3Isxdigit(zNum[2])

  31048.   ){

  31049.     u32 u = 0;

  31050.     zNum += 2;

  31051.     while( zNum[0]=='0' ) zNum++;

  31052.     for(i=0; sqlite3Isxdigit(zNum[i]) && i<8; i++){

  31053.       u = u*16 + sqlite3HexToInt(zNum[i]);

  31054.     }

  31055.     if( (u&0x80000000)==0 && sqlite3Isxdigit(zNum[i])==0 ){

  31056.       memcpy(pValue, &u, 4);

  31057.       return 1;

  31058.     }else{

  31059.       return 0;

  31060.     }

  31061.   }

  31062. #endif

  31063.   if( !sqlite3Isdigit(zNum[0]) ) return 0;

  31064.   while( zNum[0]=='0' ) zNum++;

  31065.   for(i=0; i<11 && (c = zNum[i] - '0')>=0 && c<=9; i++){

  31066.     v = v*10 + c;

  31067.   }

  31068. 

  31069.   /* The longest decimal representation of a 32 bit integer is 10 digits:

  31070.   **

  31071.   **             1234567890

  31072.   **     2^31 -> 2147483648

  31073.   */

  31074.   testcase( i==10 );

  31075.   if( i>10 ){

  31076.     return 0;

  31077.   }

  31078.   testcase( v-neg==2147483647 );

  31079.   if( v-neg>2147483647 ){

  31080.     return 0;

  31081.   }

  31082.   if( neg ){

  31083.     v = -v;

  31084.   }

  31085.   *pValue = (int)v;

  31086.   return 1;

  31087. }

  31088. 

  31089. /*

  31090. ** Return a 32-bit integer value extracted from a string.  If the

  31091. ** string is not an integer, just return 0.

  31092. */

  31093. SQLITE_PRIVATE int sqlite3Atoi(const char *z){

  31094.   int x = 0;

  31095.   if( z ) sqlite3GetInt32(z, &x);

  31096.   return x;

  31097. }

  31098. 

  31099. /*

  31100. ** The variable-length integer encoding is as follows:

  31101. **

  31102. ** KEY:

  31103. **         A = 0xxxxxxx    7 bits of data and one flag bit

  31104. **         B = 1xxxxxxx    7 bits of data and one flag bit

  31105. **         C = xxxxxxxx    8 bits of data

  31106. **

  31107. **  7 bits - A

  31108. ** 14 bits - BA

  31109. ** 21 bits - BBA

  31110. ** 28 bits - BBBA

  31111. ** 35 bits - BBBBA

  31112. ** 42 bits - BBBBBA

  31113. ** 49 bits - BBBBBBA

  31114. ** 56 bits - BBBBBBBA

  31115. ** 64 bits - BBBBBBBBC

  31116. */

  31117. 

  31118. /*

  31119. ** Write a 64-bit variable-length integer to memory starting at p[0].

  31120. ** The length of data write will be between 1 and 9 bytes.  The number

  31121. ** of bytes written is returned.

  31122. **

  31123. ** A variable-length integer consists of the lower 7 bits of each byte

  31124. ** for all bytes that have the 8th bit set and one byte with the 8th

  31125. ** bit clear.  Except, if we get to the 9th byte, it stores the full

  31126. ** 8 bits and is the last byte.

  31127. */

  31128. static int SQLITE_NOINLINE putVarint64(unsigned char *p, u64 v){

  31129.   int i, j, n;

  31130.   u8 buf[10];

  31131.   if( v & (((u64)0xff000000)<<32) ){

  31132.     p[8] = (u8)v;

  31133.     v >>= 8;

  31134.     for(i=7; i>=0; i--){

  31135.       p[i] = (u8)((v & 0x7f) | 0x80);

  31136.       v >>= 7;

  31137.     }

  31138.     return 9;

  31139.   }    

  31140.   n = 0;

  31141.   do{

  31142.     buf[n++] = (u8)((v & 0x7f) | 0x80);

  31143.     v >>= 7;

  31144.   }while( v!=0 );

  31145.   buf[0] &= 0x7f;

  31146.   assert( n<=9 );

  31147.   for(i=0, j=n-1; j>=0; j--, i++){

  31148.     p[i] = buf[j];

  31149.   }

  31150.   return n;

  31151. }

  31152. SQLITE_PRIVATE int sqlite3PutVarint(unsigned char *p, u64 v){

  31153.   if( v<=0x7f ){

  31154.     p[0] = v&0x7f;

  31155.     return 1;

  31156.   }

  31157.   if( v<=0x3fff ){

  31158.     p[0] = ((v>>7)&0x7f)|0x80;

  31159.     p[1] = v&0x7f;

  31160.     return 2;

  31161.   }

  31162.   return putVarint64(p,v);

  31163. }

  31164. 

  31165. /*

  31166. ** Bitmasks used by sqlite3GetVarint().  These precomputed constants

  31167. ** are defined here rather than simply putting the constant expressions

  31168. ** inline in order to work around bugs in the RVT compiler.

  31169. **

  31170. ** SLOT_2_0     A mask for  (0x7f<<14) | 0x7f

  31171. **

  31172. ** SLOT_4_2_0   A mask for  (0x7f<<28) | SLOT_2_0

  31173. */

  31174. #define SLOT_2_0     0x001fc07f

  31175. #define SLOT_4_2_0   0xf01fc07f

  31176. 

  31177. 

  31178. /*

  31179. ** Read a 64-bit variable-length integer from memory starting at p[0].

  31180. ** Return the number of bytes read.  The value is stored in *v.

  31181. */

  31182. SQLITE_PRIVATE u8 sqlite3GetVarint(const unsigned char *p, u64 *v){

  31183.   u32 a,b,s;

  31184. 

  31185.   if( ((signed char*)p)[0]>=0 ){

  31186.     *v = *p;

  31187.     return 1;

  31188.   }

  31189.   if( ((signed char*)p)[1]>=0 ){

  31190.     *v = ((u32)(p[0]&0x7f)<<7) | p[1];

  31191.     return 2;

  31192.   }

  31193. 

  31194.   /* Verify that constants are precomputed correctly */

  31195.   assert( SLOT_2_0 == ((0x7f<<14) | (0x7f)) );

  31196.   assert( SLOT_4_2_0 == ((0xfU<<28) | (0x7f<<14) | (0x7f)) );

  31197. 

  31198.   a = ((u32)p[0])<<14;

  31199.   b = p[1];

  31200.   p += 2;

  31201.   a |= *p;

  31202.   /* a: p0<<14 | p2 (unmasked) */

  31203.   if (!(a&0x80))

  31204.   {

  31205.     a &= SLOT_2_0;

  31206.     b &= 0x7f;

  31207.     b = b<<7;

  31208.     a |= b;

  31209.     *v = a;

  31210.     return 3;

  31211.   }

  31212. 

  31213.   /* CSE1 from below */

  31214.   a &= SLOT_2_0;

  31215.   p++;

  31216.   b = b<<14;

  31217.   b |= *p;

  31218.   /* b: p1<<14 | p3 (unmasked) */

  31219.   if (!(b&0x80))

  31220.   {

  31221.     b &= SLOT_2_0;

  31222.     /* moved CSE1 up */

  31223.     /* a &= (0x7f<<14)|(0x7f); */

  31224.     a = a<<7;

  31225.     a |= b;

  31226.     *v = a;

  31227.     return 4;

  31228.   }

  31229. 

  31230.   /* a: p0<<14 | p2 (masked) */

  31231.   /* b: p1<<14 | p3 (unmasked) */

  31232.   /* 1:save off p0<<21 | p1<<14 | p2<<7 | p3 (masked) */

  31233.   /* moved CSE1 up */

  31234.   /* a &= (0x7f<<14)|(0x7f); */

  31235.   b &= SLOT_2_0;

  31236.   s = a;

  31237.   /* s: p0<<14 | p2 (masked) */

  31238. 

  31239.   p++;

  31240.   a = a<<14;

  31241.   a |= *p;

  31242.   /* a: p0<<28 | p2<<14 | p4 (unmasked) */

  31243.   if (!(a&0x80))

  31244.   {

  31245.     /* we can skip these cause they were (effectively) done above

  31246.     ** while calculating s */

  31247.     /* a &= (0x7f<<28)|(0x7f<<14)|(0x7f); */

  31248.     /* b &= (0x7f<<14)|(0x7f); */

  31249.     b = b<<7;

  31250.     a |= b;

  31251.     s = s>>18;

  31252.     *v = ((u64)s)<<32 | a;

  31253.     return 5;

  31254.   }

  31255. 

  31256.   /* 2:save off p0<<21 | p1<<14 | p2<<7 | p3 (masked) */

  31257.   s = s<<7;

  31258.   s |= b;

  31259.   /* s: p0<<21 | p1<<14 | p2<<7 | p3 (masked) */

  31260. 

  31261.   p++;

  31262.   b = b<<14;

  31263.   b |= *p;

  31264.   /* b: p1<<28 | p3<<14 | p5 (unmasked) */

  31265.   if (!(b&0x80))

  31266.   {

  31267.     /* we can skip this cause it was (effectively) done above in calc'ing s */

  31268.     /* b &= (0x7f<<28)|(0x7f<<14)|(0x7f); */

  31269.     a &= SLOT_2_0;

  31270.     a = a<<7;

  31271.     a |= b;

  31272.     s = s>>18;

  31273.     *v = ((u64)s)<<32 | a;

  31274.     return 6;

  31275.   }

  31276. 

  31277.   p++;

  31278.   a = a<<14;

  31279.   a |= *p;

  31280.   /* a: p2<<28 | p4<<14 | p6 (unmasked) */

  31281.   if (!(a&0x80))

  31282.   {

  31283.     a &= SLOT_4_2_0;

  31284.     b &= SLOT_2_0;

  31285.     b = b<<7;

  31286.     a |= b;

  31287.     s = s>>11;

  31288.     *v = ((u64)s)<<32 | a;

  31289.     return 7;

  31290.   }

  31291. 

  31292.   /* CSE2 from below */

  31293.   a &= SLOT_2_0;

  31294.   p++;

  31295.   b = b<<14;

  31296.   b |= *p;

  31297.   /* b: p3<<28 | p5<<14 | p7 (unmasked) */

  31298.   if (!(b&0x80))

  31299.   {

  31300.     b &= SLOT_4_2_0;

  31301.     /* moved CSE2 up */

  31302.     /* a &= (0x7f<<14)|(0x7f); */

  31303.     a = a<<7;

  31304.     a |= b;

  31305.     s = s>>4;

  31306.     *v = ((u64)s)<<32 | a;

  31307.     return 8;

  31308.   }

  31309. 

  31310.   p++;

  31311.   a = a<<15;

  31312.   a |= *p;

  31313.   /* a: p4<<29 | p6<<15 | p8 (unmasked) */

  31314. 

  31315.   /* moved CSE2 up */

  31316.   /* a &= (0x7f<<29)|(0x7f<<15)|(0xff); */

  31317.   b &= SLOT_2_0;

  31318.   b = b<<8;

  31319.   a |= b;

  31320. 

  31321.   s = s<<4;

  31322.   b = p[-4];

  31323.   b &= 0x7f;

  31324.   b = b>>3;

  31325.   s |= b;

  31326. 

  31327.   *v = ((u64)s)<<32 | a;

  31328. 

  31329.   return 9;

  31330. }

  31331. 

  31332. /*

  31333. ** Read a 32-bit variable-length integer from memory starting at p[0].

  31334. ** Return the number of bytes read.  The value is stored in *v.

  31335. **

  31336. ** If the varint stored in p[0] is larger than can fit in a 32-bit unsigned

  31337. ** integer, then set *v to 0xffffffff.

  31338. **

  31339. ** A MACRO version, getVarint32, is provided which inlines the 

  31340. ** single-byte case.  All code should use the MACRO version as 

  31341. ** this function assumes the single-byte case has already been handled.

  31342. */

  31343. SQLITE_PRIVATE u8 sqlite3GetVarint32(const unsigned char *p, u32 *v){

  31344.   u32 a,b;

  31345. 

  31346.   /* The 1-byte case.  Overwhelmingly the most common.  Handled inline

  31347.   ** by the getVarin32() macro */

  31348.   a = *p;

  31349.   /* a: p0 (unmasked) */

  31350. #ifndef getVarint32

  31351.   if (!(a&0x80))

  31352.   {

  31353.     /* Values between 0 and 127 */

  31354.     *v = a;

  31355.     return 1;

  31356.   }

  31357. #endif

  31358. 

  31359.   /* The 2-byte case */

  31360.   p++;

  31361.   b = *p;

  31362.   /* b: p1 (unmasked) */

  31363.   if (!(b&0x80))

  31364.   {

  31365.     /* Values between 128 and 16383 */

  31366.     a &= 0x7f;

  31367.     a = a<<7;

  31368.     *v = a | b;

  31369.     return 2;

  31370.   }

  31371. 

  31372.   /* The 3-byte case */

  31373.   p++;

  31374.   a = a<<14;

  31375.   a |= *p;

  31376.   /* a: p0<<14 | p2 (unmasked) */

  31377.   if (!(a&0x80))

  31378.   {

  31379.     /* Values between 16384 and 2097151 */

  31380.     a &= (0x7f<<14)|(0x7f);

  31381.     b &= 0x7f;

  31382.     b = b<<7;

  31383.     *v = a | b;

  31384.     return 3;

  31385.   }

  31386. 

  31387.   /* A 32-bit varint is used to store size information in btrees.

  31388.   ** Objects are rarely larger than 2MiB limit of a 3-byte varint.

  31389.   ** A 3-byte varint is sufficient, for example, to record the size

  31390.   ** of a 1048569-byte BLOB or string.

  31391.   **

  31392.   ** We only unroll the first 1-, 2-, and 3- byte cases.  The very

  31393.   ** rare larger cases can be handled by the slower 64-bit varint

  31394.   ** routine.

  31395.   */

  31396. #if 1

  31397.   {

  31398.     u64 v64;

  31399.     u8 n;

  31400. 

  31401.     p -= 2;

  31402.     n = sqlite3GetVarint(p, &v64);

  31403.     assert( n>3 && n<=9 );

  31404.     if( (v64 & SQLITE_MAX_U32)!=v64 ){

  31405.       *v = 0xffffffff;

  31406.     }else{

  31407.       *v = (u32)v64;

  31408.     }

  31409.     return n;

  31410.   }

  31411. 

  31412. #else

  31413.   /* For following code (kept for historical record only) shows an

  31414.   ** unrolling for the 3- and 4-byte varint cases.  This code is

  31415.   ** slightly faster, but it is also larger and much harder to test.

  31416.   */

  31417.   p++;

  31418.   b = b<<14;

  31419.   b |= *p;

  31420.   /* b: p1<<14 | p3 (unmasked) */

  31421.   if (!(b&0x80))

  31422.   {

  31423.     /* Values between 2097152 and 268435455 */

  31424.     b &= (0x7f<<14)|(0x7f);

  31425.     a &= (0x7f<<14)|(0x7f);

  31426.     a = a<<7;

  31427.     *v = a | b;

  31428.     return 4;

  31429.   }

  31430. 

  31431.   p++;

  31432.   a = a<<14;

  31433.   a |= *p;

  31434.   /* a: p0<<28 | p2<<14 | p4 (unmasked) */

  31435.   if (!(a&0x80))

  31436.   {

  31437.     /* Values  between 268435456 and 34359738367 */

  31438.     a &= SLOT_4_2_0;

  31439.     b &= SLOT_4_2_0;

  31440.     b = b<<7;

  31441.     *v = a | b;

  31442.     return 5;

  31443.   }

  31444. 

  31445.   /* We can only reach this point when reading a corrupt database

  31446.   ** file.  In that case we are not in any hurry.  Use the (relatively

  31447.   ** slow) general-purpose sqlite3GetVarint() routine to extract the

  31448.   ** value. */

  31449.   {

  31450.     u64 v64;

  31451.     u8 n;

  31452. 

  31453.     p -= 4;

  31454.     n = sqlite3GetVarint(p, &v64);

  31455.     assert( n>5 && n<=9 );

  31456.     *v = (u32)v64;

  31457.     return n;

  31458.   }

  31459. #endif

  31460. }

  31461. 

  31462. /*

  31463. ** Return the number of bytes that will be needed to store the given

  31464. ** 64-bit integer.

  31465. */

  31466. SQLITE_PRIVATE int sqlite3VarintLen(u64 v){

  31467.   int i;

  31468.   for(i=1; (v >>= 7)!=0; i++){ assert( i<10 ); }

  31469.   return i;

  31470. }

  31471. 

  31472. 

  31473. /*

  31474. ** Read or write a four-byte big-endian integer value.

  31475. */

  31476. SQLITE_PRIVATE u32 sqlite3Get4byte(const u8 *p){

  31477. #if SQLITE_BYTEORDER==4321

  31478.   u32 x;

  31479.   memcpy(&x,p,4);

  31480.   return x;

  31481. #elif SQLITE_BYTEORDER==1234 && GCC_VERSION>=4003000

  31482.   u32 x;

  31483.   memcpy(&x,p,4);

  31484.   return __builtin_bswap32(x);

  31485. #elif SQLITE_BYTEORDER==1234 && MSVC_VERSION>=1300

  31486.   u32 x;

  31487.   memcpy(&x,p,4);

  31488.   return _byteswap_ulong(x);

  31489. #else

  31490.   testcase( p[0]&0x80 );

  31491.   return ((unsigned)p[0]<<24) | (p[1]<<16) | (p[2]<<8) | p[3];

  31492. #endif

  31493. }

  31494. SQLITE_PRIVATE void sqlite3Put4byte(unsigned char *p, u32 v){

  31495. #if SQLITE_BYTEORDER==4321

  31496.   memcpy(p,&v,4);

  31497. #elif SQLITE_BYTEORDER==1234 && GCC_VERSION>=4003000

  31498.   u32 x = __builtin_bswap32(v);

  31499.   memcpy(p,&x,4);

  31500. #elif SQLITE_BYTEORDER==1234 && MSVC_VERSION>=1300

  31501.   u32 x = _byteswap_ulong(v);

  31502.   memcpy(p,&x,4);

  31503. #else

  31504.   p[0] = (u8)(v>>24);

  31505.   p[1] = (u8)(v>>16);

  31506.   p[2] = (u8)(v>>8);

  31507.   p[3] = (u8)v;

  31508. #endif

  31509. }

  31510. 

  31511. 

  31512. 

  31513. /*

  31514. ** Translate a single byte of Hex into an integer.

  31515. ** This routine only works if h really is a valid hexadecimal

  31516. ** character:  0..9a..fA..F

  31517. */

  31518. SQLITE_PRIVATE u8 sqlite3HexToInt(int h){

  31519.   assert( (h>='0' && h<='9') ||  (h>='a' && h<='f') ||  (h>='A' && h<='F') );

  31520. #ifdef SQLITE_ASCII

  31521.   h += 9*(1&(h>>6));

  31522. #endif

  31523. #ifdef SQLITE_EBCDIC

  31524.   h += 9*(1&~(h>>4));

  31525. #endif

  31526.   return (u8)(h & 0xf);

  31527. }

  31528. 

  31529. #if !defined(SQLITE_OMIT_BLOB_LITERAL) || defined(SQLITE_HAS_CODEC)

  31530. /*

  31531. ** Convert a BLOB literal of the form "x'hhhhhh'" into its binary

  31532. ** value.  Return a pointer to its binary value.  Space to hold the

  31533. ** binary value has been obtained from malloc and must be freed by

  31534. ** the calling routine.

  31535. */

  31536. SQLITE_PRIVATE void *sqlite3HexToBlob(sqlite3 *db, const char *z, int n){

  31537.   char *zBlob;

  31538.   int i;

  31539. 

  31540.   zBlob = (char *)sqlite3DbMallocRawNN(db, n/2 + 1);

  31541.   n--;

  31542.   if( zBlob ){

  31543.     for(i=0; i<n; i+=2){

  31544.       zBlob[i/2] = (sqlite3HexToInt(z[i])<<4) | sqlite3HexToInt(z[i+1]);

  31545.     }

  31546.     zBlob[i/2] = 0;

  31547.   }

  31548.   return zBlob;

  31549. }

  31550. #endif /* !SQLITE_OMIT_BLOB_LITERAL || SQLITE_HAS_CODEC */

  31551. 

  31552. /*

  31553. ** Log an error that is an API call on a connection pointer that should

  31554. ** not have been used.  The "type" of connection pointer is given as the

  31555. ** argument.  The zType is a word like "NULL" or "closed" or "invalid".

  31556. */

  31557. static void logBadConnection(const char *zType){

  31558.   sqlite3_log(SQLITE_MISUSE, 

  31559.      "API call with %s database connection pointer",

  31560.      zType

  31561.   );

  31562. }

  31563. 

  31564. /*

  31565. ** Check to make sure we have a valid db pointer.  This test is not

  31566. ** foolproof but it does provide some measure of protection against

  31567. ** misuse of the interface such as passing in db pointers that are

  31568. ** NULL or which have been previously closed.  If this routine returns

  31569. ** 1 it means that the db pointer is valid and 0 if it should not be

  31570. ** dereferenced for any reason.  The calling function should invoke

  31571. ** SQLITE_MISUSE immediately.

  31572. **

  31573. ** sqlite3SafetyCheckOk() requires that the db pointer be valid for

  31574. ** use.  sqlite3SafetyCheckSickOrOk() allows a db pointer that failed to

  31575. ** open properly and is not fit for general use but which can be

  31576. ** used as an argument to sqlite3_errmsg() or sqlite3_close().

  31577. */

  31578. SQLITE_PRIVATE int sqlite3SafetyCheckOk(sqlite3 *db){

  31579.   u32 magic;

  31580.   if( db==0 ){

  31581.     logBadConnection("NULL");

  31582.     return 0;

  31583.   }

  31584.   magic = db->magic;

  31585.   if( magic!=SQLITE_MAGIC_OPEN ){

  31586.     if( sqlite3SafetyCheckSickOrOk(db) ){

  31587.       testcase( sqlite3GlobalConfig.xLog!=0 );

  31588.       logBadConnection("unopened");

  31589.     }

  31590.     return 0;

  31591.   }else{

  31592.     return 1;

  31593.   }

  31594. }

  31595. SQLITE_PRIVATE int sqlite3SafetyCheckSickOrOk(sqlite3 *db){

  31596.   u32 magic;

  31597.   magic = db->magic;

  31598.   if( magic!=SQLITE_MAGIC_SICK &&

  31599.       magic!=SQLITE_MAGIC_OPEN &&

  31600.       magic!=SQLITE_MAGIC_BUSY ){

  31601.     testcase( sqlite3GlobalConfig.xLog!=0 );

  31602.     logBadConnection("invalid");

  31603.     return 0;

  31604.   }else{

  31605.     return 1;

  31606.   }

  31607. }

  31608. 

  31609. /*

  31610. ** Attempt to add, substract, or multiply the 64-bit signed value iB against

  31611. ** the other 64-bit signed integer at *pA and store the result in *pA.

  31612. ** Return 0 on success.  Or if the operation would have resulted in an

  31613. ** overflow, leave *pA unchanged and return 1.

  31614. */

  31615. SQLITE_PRIVATE int sqlite3AddInt64(i64 *pA, i64 iB){

  31616. #if GCC_VERSION>=5004000 && !defined(__INTEL_COMPILER)

  31617.   return __builtin_add_overflow(*pA, iB, pA);

  31618. #else

  31619.   i64 iA = *pA;

  31620.   testcase( iA==0 ); testcase( iA==1 );

  31621.   testcase( iB==-1 ); testcase( iB==0 );

  31622.   if( iB>=0 ){

  31623.     testcase( iA>0 && LARGEST_INT64 - iA == iB );

  31624.     testcase( iA>0 && LARGEST_INT64 - iA == iB - 1 );

  31625.     if( iA>0 && LARGEST_INT64 - iA < iB ) return 1;

  31626.   }else{

  31627.     testcase( iA<0 && -(iA + LARGEST_INT64) == iB + 1 );

  31628.     testcase( iA<0 && -(iA + LARGEST_INT64) == iB + 2 );

  31629.     if( iA<0 && -(iA + LARGEST_INT64) > iB + 1 ) return 1;

  31630.   }

  31631.   *pA += iB;

  31632.   return 0; 

  31633. #endif

  31634. }

  31635. SQLITE_PRIVATE int sqlite3SubInt64(i64 *pA, i64 iB){

  31636. #if GCC_VERSION>=5004000 && !defined(__INTEL_COMPILER)

  31637.   return __builtin_sub_overflow(*pA, iB, pA);

  31638. #else

  31639.   testcase( iB==SMALLEST_INT64+1 );

  31640.   if( iB==SMALLEST_INT64 ){

  31641.     testcase( (*pA)==(-1) ); testcase( (*pA)==0 );

  31642.     if( (*pA)>=0 ) return 1;

  31643.     *pA -= iB;

  31644.     return 0;

  31645.   }else{

  31646.     return sqlite3AddInt64(pA, -iB);

  31647.   }

  31648. #endif

  31649. }

  31650. SQLITE_PRIVATE int sqlite3MulInt64(i64 *pA, i64 iB){

  31651. #if GCC_VERSION>=5004000 && !defined(__INTEL_COMPILER)

  31652.   return __builtin_mul_overflow(*pA, iB, pA);

  31653. #else

  31654.   i64 iA = *pA;

  31655.   if( iB>0 ){

  31656.     if( iA>LARGEST_INT64/iB ) return 1;

  31657.     if( iA<SMALLEST_INT64/iB ) return 1;

  31658.   }else if( iB<0 ){

  31659.     if( iA>0 ){

  31660.       if( iB<SMALLEST_INT64/iA ) return 1;

  31661.     }else if( iA<0 ){

  31662.       if( iB==SMALLEST_INT64 ) return 1;

  31663.       if( iA==SMALLEST_INT64 ) return 1;

  31664.       if( -iA>LARGEST_INT64/-iB ) return 1;

  31665.     }

  31666.   }

  31667.   *pA = iA*iB;

  31668.   return 0;

  31669. #endif

  31670. }

  31671. 

  31672. /*

  31673. ** Compute the absolute value of a 32-bit signed integer, of possible.  Or 

  31674. ** if the integer has a value of -2147483648, return +2147483647

  31675. */

  31676. SQLITE_PRIVATE int sqlite3AbsInt32(int x){

  31677.   if( x>=0 ) return x;

  31678.   if( x==(int)0x80000000 ) return 0x7fffffff;

  31679.   return -x;

  31680. }

  31681. 

  31682. #ifdef SQLITE_ENABLE_8_3_NAMES

  31683. /*

  31684. ** If SQLITE_ENABLE_8_3_NAMES is set at compile-time and if the database

  31685. ** filename in zBaseFilename is a URI with the "8_3_names=1" parameter and

  31686. ** if filename in z[] has a suffix (a.k.a. "extension") that is longer than

  31687. ** three characters, then shorten the suffix on z[] to be the last three

  31688. ** characters of the original suffix.

  31689. **

  31690. ** If SQLITE_ENABLE_8_3_NAMES is set to 2 at compile-time, then always

  31691. ** do the suffix shortening regardless of URI parameter.

  31692. **

  31693. ** Examples:

  31694. **

  31695. **     test.db-journal    =>   test.nal

  31696. **     test.db-wal        =>   test.wal

  31697. **     test.db-shm        =>   test.shm

  31698. **     test.db-mj7f3319fa =>   test.9fa

  31699. */

  31700. SQLITE_PRIVATE void sqlite3FileSuffix3(const char *zBaseFilename, char *z){

  31701. #if SQLITE_ENABLE_8_3_NAMES<2

  31702.   if( sqlite3_uri_boolean(zBaseFilename, "8_3_names", 0) )

  31703. #endif

  31704.   {

  31705.     int i, sz;

  31706.     sz = sqlite3Strlen30(z);

  31707.     for(i=sz-1; i>0 && z[i]!='/' && z[i]!='.'; i--){}

  31708.     if( z[i]=='.' && ALWAYS(sz>i+4) ) memmove(&z[i+1], &z[sz-3], 4);

  31709.   }

  31710. }

  31711. #endif

  31712. 

  31713. /* 

  31714. ** Find (an approximate) sum of two LogEst values.  This computation is

  31715. ** not a simple "+" operator because LogEst is stored as a logarithmic

  31716. ** value.

  31717. ** 

  31718. */

  31719. SQLITE_PRIVATE LogEst sqlite3LogEstAdd(LogEst a, LogEst b){

  31720.   static const unsigned char x[] = {

  31721.      10, 10,                         /* 0,1 */

  31722.       9, 9,                          /* 2,3 */

  31723.       8, 8,                          /* 4,5 */

  31724.       7, 7, 7,                       /* 6,7,8 */

  31725.       6, 6, 6,                       /* 9,10,11 */

  31726.       5, 5, 5,                       /* 12-14 */

  31727.       4, 4, 4, 4,                    /* 15-18 */

  31728.       3, 3, 3, 3, 3, 3,              /* 19-24 */

  31729.       2, 2, 2, 2, 2, 2, 2,           /* 25-31 */

  31730.   };

  31731.   if( a>=b ){

  31732.     if( a>b+49 ) return a;

  31733.     if( a>b+31 ) return a+1;

  31734.     return a+x[a-b];

  31735.   }else{

  31736.     if( b>a+49 ) return b;

  31737.     if( b>a+31 ) return b+1;

  31738.     return b+x[b-a];

  31739.   }

  31740. }

  31741. 

  31742. /*

  31743. ** Convert an integer into a LogEst.  In other words, compute an

  31744. ** approximation for 10*log2(x).

  31745. */

  31746. SQLITE_PRIVATE LogEst sqlite3LogEst(u64 x){

  31747.   static LogEst a[] = { 0, 2, 3, 5, 6, 7, 8, 9 };

  31748.   LogEst y = 40;

  31749.   if( x<8 ){

  31750.     if( x<2 ) return 0;

  31751.     while( x<8 ){  y -= 10; x <<= 1; }

  31752.   }else{

  31753. #if GCC_VERSION>=5004000

  31754.     int i = 60 - __builtin_clzll(x);

  31755.     y += i*10;

  31756.     x >>= i;

  31757. #else

  31758.     while( x>255 ){ y += 40; x >>= 4; }  /*OPTIMIZATION-IF-TRUE*/

  31759.     while( x>15 ){  y += 10; x >>= 1; }

  31760. #endif

  31761.   }

  31762.   return a[x&7] + y - 10;

  31763. }

  31764. 

  31765. #ifndef SQLITE_OMIT_VIRTUALTABLE

  31766. /*

  31767. ** Convert a double into a LogEst

  31768. ** In other words, compute an approximation for 10*log2(x).

  31769. */

  31770. SQLITE_PRIVATE LogEst sqlite3LogEstFromDouble(double x){

  31771.   u64 a;

  31772.   LogEst e;

  31773.   assert( sizeof(x)==8 && sizeof(a)==8 );

  31774.   if( x<=1 ) return 0;

  31775.   if( x<=2000000000 ) return sqlite3LogEst((u64)x);

  31776.   memcpy(&a, &x, 8);

  31777.   e = (a>>52) - 1022;

  31778.   return e*10;

  31779. }

  31780. #endif /* SQLITE_OMIT_VIRTUALTABLE */

  31781. 

  31782. #if defined(SQLITE_ENABLE_STMT_SCANSTATUS) || \

  31783.     defined(SQLITE_ENABLE_STAT3_OR_STAT4) || \

  31784.     defined(SQLITE_EXPLAIN_ESTIMATED_ROWS)

  31785. /*

  31786. ** Convert a LogEst into an integer.

  31787. **

  31788. ** Note that this routine is only used when one or more of various

  31789. ** non-standard compile-time options is enabled.

  31790. */

  31791. SQLITE_PRIVATE u64 sqlite3LogEstToInt(LogEst x){

  31792.   u64 n;

  31793.   n = x%10;

  31794.   x /= 10;

  31795.   if( n>=5 ) n -= 2;

  31796.   else if( n>=1 ) n -= 1;

  31797. #if defined(SQLITE_ENABLE_STMT_SCANSTATUS) || \

  31798.     defined(SQLITE_EXPLAIN_ESTIMATED_ROWS)

  31799.   if( x>60 ) return (u64)LARGEST_INT64;

  31800. #else

  31801.   /* If only SQLITE_ENABLE_STAT3_OR_STAT4 is on, then the largest input

  31802.   ** possible to this routine is 310, resulting in a maximum x of 31 */

  31803.   assert( x<=60 );

  31804. #endif

  31805.   return x>=3 ? (n+8)<<(x-3) : (n+8)>>(3-x);

  31806. }

  31807. #endif /* defined SCANSTAT or STAT4 or ESTIMATED_ROWS */

  31808. 

  31809. /*

  31810. ** Add a new name/number pair to a VList.  This might require that the

  31811. ** VList object be reallocated, so return the new VList.  If an OOM

  31812. ** error occurs, the original VList returned and the

  31813. ** db->mallocFailed flag is set.

  31814. **

  31815. ** A VList is really just an array of integers.  To destroy a VList,

  31816. ** simply pass it to sqlite3DbFree().

  31817. **

  31818. ** The first integer is the number of integers allocated for the whole

  31819. ** VList.  The second integer is the number of integers actually used.

  31820. ** Each name/number pair is encoded by subsequent groups of 3 or more

  31821. ** integers.

  31822. **

  31823. ** Each name/number pair starts with two integers which are the numeric

  31824. ** value for the pair and the size of the name/number pair, respectively.

  31825. ** The text name overlays one or more following integers.  The text name

  31826. ** is always zero-terminated.

  31827. **

  31828. ** Conceptually:

  31829. **

  31830. **    struct VList {

  31831. **      int nAlloc;   // Number of allocated slots 

  31832. **      int nUsed;    // Number of used slots 

  31833. **      struct VListEntry {

  31834. **        int iValue;    // Value for this entry

  31835. **        int nSlot;     // Slots used by this entry

  31836. **        // ... variable name goes here

  31837. **      } a[0];

  31838. **    }

  31839. **

  31840. ** During code generation, pointers to the variable names within the

  31841. ** VList are taken.  When that happens, nAlloc is set to zero as an 

  31842. ** indication that the VList may never again be enlarged, since the

  31843. ** accompanying realloc() would invalidate the pointers.

  31844. */

  31845. SQLITE_PRIVATE VList *sqlite3VListAdd(

  31846.   sqlite3 *db,           /* The database connection used for malloc() */

  31847.   VList *pIn,            /* The input VList.  Might be NULL */

  31848.   const char *zName,     /* Name of symbol to add */

  31849.   int nName,             /* Bytes of text in zName */

  31850.   int iVal               /* Value to associate with zName */

  31851. ){

  31852.   int nInt;              /* number of sizeof(int) objects needed for zName */

  31853.   char *z;               /* Pointer to where zName will be stored */

  31854.   int i;                 /* Index in pIn[] where zName is stored */

  31855. 

  31856.   nInt = nName/4 + 3;

  31857.   assert( pIn==0 || pIn[0]>=3 );  /* Verify ok to add new elements */

  31858.   if( pIn==0 || pIn[1]+nInt > pIn[0] ){

  31859.     /* Enlarge the allocation */

  31860.     sqlite3_int64 nAlloc = (pIn ? 2*(sqlite3_int64)pIn[0] : 10) + nInt;

  31861.     VList *pOut = sqlite3DbRealloc(db, pIn, nAlloc*sizeof(int));

  31862.     if( pOut==0 ) return pIn;

  31863.     if( pIn==0 ) pOut[1] = 2;

  31864.     pIn = pOut;

  31865.     pIn[0] = nAlloc;

  31866.   }

  31867.   i = pIn[1];

  31868.   pIn[i] = iVal;

  31869.   pIn[i+1] = nInt;

  31870.   z = (char*)&pIn[i+2];

  31871.   pIn[1] = i+nInt;

  31872.   assert( pIn[1]<=pIn[0] );

  31873.   memcpy(z, zName, nName);

  31874.   z[nName] = 0;

  31875.   return pIn;

  31876. }

  31877. 

  31878. /*

  31879. ** Return a pointer to the name of a variable in the given VList that

  31880. ** has the value iVal.  Or return a NULL if there is no such variable in

  31881. ** the list

  31882. */

  31883. SQLITE_PRIVATE const char *sqlite3VListNumToName(VList *pIn, int iVal){

  31884.   int i, mx;

  31885.   if( pIn==0 ) return 0;

  31886.   mx = pIn[1];

  31887.   i = 2;

  31888.   do{

  31889.     if( pIn[i]==iVal ) return (char*)&pIn[i+2];

  31890.     i += pIn[i+1];

  31891.   }while( i<mx );

  31892.   return 0;

  31893. }

  31894. 

  31895. /*

  31896. ** Return the number of the variable named zName, if it is in VList.

  31897. ** or return 0 if there is no such variable.

  31898. */

  31899. SQLITE_PRIVATE int sqlite3VListNameToNum(VList *pIn, const char *zName, int nName){

  31900.   int i, mx;

  31901.   if( pIn==0 ) return 0;

  31902.   mx = pIn[1];

  31903.   i = 2;

  31904.   do{

  31905.     const char *z = (const char*)&pIn[i+2];

  31906.     if( strncmp(z,zName,nName)==0 && z[nName]==0 ) return pIn[i];

  31907.     i += pIn[i+1];

  31908.   }while( i<mx );

  31909.   return 0;

  31910. }

  31911. 

  31912. /************** End of util.c ************************************************/

  31913. /************** Begin file hash.c ********************************************/

  31914. /*

  31915. ** 2001 September 22

  31916. **

  31917. ** The author disclaims copyright to this source code.  In place of

  31918. ** a legal notice, here is a blessing:

  31919. **

  31920. **    May you do good and not evil.

  31921. **    May you find forgiveness for yourself and forgive others.

  31922. **    May you share freely, never taking more than you give.

  31923. **

  31924. *************************************************************************

  31925. ** This is the implementation of generic hash-tables

  31926. ** used in SQLite.

  31927. */

  31928. /* #include "sqliteInt.h" */

  31929. /* #include <assert.h> */

  31930. 

  31931. /* Turn bulk memory into a hash table object by initializing the

  31932. ** fields of the Hash structure.

  31933. **

  31934. ** "pNew" is a pointer to the hash table that is to be initialized.

  31935. */

  31936. SQLITE_PRIVATE void sqlite3HashInit(Hash *pNew){

  31937.   assert( pNew!=0 );

  31938.   pNew->first = 0;

  31939.   pNew->count = 0;

  31940.   pNew->htsize = 0;

  31941.   pNew->ht = 0;

  31942. }

  31943. 

  31944. /* Remove all entries from a hash table.  Reclaim all memory.

  31945. ** Call this routine to delete a hash table or to reset a hash table

  31946. ** to the empty state.

  31947. */

  31948. SQLITE_PRIVATE void sqlite3HashClear(Hash *pH){

  31949.   HashElem *elem;         /* For looping over all elements of the table */

  31950. 

  31951.   assert( pH!=0 );

  31952.   elem = pH->first;

  31953.   pH->first = 0;

  31954.   sqlite3_free(pH->ht);

  31955.   pH->ht = 0;

  31956.   pH->htsize = 0;

  31957.   while( elem ){

  31958.     HashElem *next_elem = elem->next;

  31959.     sqlite3_free(elem);

  31960.     elem = next_elem;

  31961.   }

  31962.   pH->count = 0;

  31963. }

  31964. 

  31965. /*

  31966. ** The hashing function.

  31967. */

  31968. static unsigned int strHash(const char *z){

  31969.   unsigned int h = 0;

  31970.   unsigned char c;

  31971.   while( (c = (unsigned char)*z++)!=0 ){     /*OPTIMIZATION-IF-TRUE*/

  31972.     /* Knuth multiplicative hashing.  (Sorting & Searching, p. 510).

  31973.     ** 0x9e3779b1 is 2654435761 which is the closest prime number to

  31974.     ** (2**32)*golden_ratio, where golden_ratio = (sqrt(5) - 1)/2. */

  31975.     h += sqlite3UpperToLower[c];

  31976.     h *= 0x9e3779b1;

  31977.   }

  31978.   return h;

  31979. }

  31980. 

  31981. 

  31982. /* Link pNew element into the hash table pH.  If pEntry!=0 then also

  31983. ** insert pNew into the pEntry hash bucket.

  31984. */

  31985. static void insertElement(

  31986.   Hash *pH,              /* The complete hash table */

  31987.   struct _ht *pEntry,    /* The entry into which pNew is inserted */

  31988.   HashElem *pNew         /* The element to be inserted */

  31989. ){

  31990.   HashElem *pHead;       /* First element already in pEntry */

  31991.   if( pEntry ){

  31992.     pHead = pEntry->count ? pEntry->chain : 0;

  31993.     pEntry->count++;

  31994.     pEntry->chain = pNew;

  31995.   }else{

  31996.     pHead = 0;

  31997.   }

  31998.   if( pHead ){

  31999.     pNew->next = pHead;

  32000.     pNew->prev = pHead->prev;

  32001.     if( pHead->prev ){ pHead->prev->next = pNew; }

  32002.     else             { pH->first = pNew; }

  32003.     pHead->prev = pNew;

  32004.   }else{

  32005.     pNew->next = pH->first;

  32006.     if( pH->first ){ pH->first->prev = pNew; }

  32007.     pNew->prev = 0;

  32008.     pH->first = pNew;

  32009.   }

  32010. }

  32011. 

  32012. 

  32013. /* Resize the hash table so that it cantains "new_size" buckets.

  32014. **

  32015. ** The hash table might fail to resize if sqlite3_malloc() fails or

  32016. ** if the new size is the same as the prior size.

  32017. ** Return TRUE if the resize occurs and false if not.

  32018. */

  32019. static int rehash(Hash *pH, unsigned int new_size){

  32020.   struct _ht *new_ht;            /* The new hash table */

  32021.   HashElem *elem, *next_elem;    /* For looping over existing elements */

  32022. 

  32023. #if SQLITE_MALLOC_SOFT_LIMIT>0

  32024.   if( new_size*sizeof(struct _ht)>SQLITE_MALLOC_SOFT_LIMIT ){

  32025.     new_size = SQLITE_MALLOC_SOFT_LIMIT/sizeof(struct _ht);

  32026.   }

  32027.   if( new_size==pH->htsize ) return 0;

  32028. #endif

  32029. 

  32030.   /* The inability to allocates space for a larger hash table is

  32031.   ** a performance hit but it is not a fatal error.  So mark the

  32032.   ** allocation as a benign. Use sqlite3Malloc()/memset(0) instead of 

  32033.   ** sqlite3MallocZero() to make the allocation, as sqlite3MallocZero()

  32034.   ** only zeroes the requested number of bytes whereas this module will

  32035.   ** use the actual amount of space allocated for the hash table (which

  32036.   ** may be larger than the requested amount).

  32037.   */

  32038.   sqlite3BeginBenignMalloc();

  32039.   new_ht = (struct _ht *)sqlite3Malloc( new_size*sizeof(struct _ht) );

  32040.   sqlite3EndBenignMalloc();

  32041. 

  32042.   if( new_ht==0 ) return 0;

  32043.   sqlite3_free(pH->ht);

  32044.   pH->ht = new_ht;

  32045.   pH->htsize = new_size = sqlite3MallocSize(new_ht)/sizeof(struct _ht);

  32046.   memset(new_ht, 0, new_size*sizeof(struct _ht));

  32047.   for(elem=pH->first, pH->first=0; elem; elem = next_elem){

  32048.     unsigned int h = strHash(elem->pKey) % new_size;

  32049.     next_elem = elem->next;

  32050.     insertElement(pH, &new_ht[h], elem);

  32051.   }

  32052.   return 1;

  32053. }

  32054. 

  32055. /* This function (for internal use only) locates an element in an

  32056. ** hash table that matches the given key.  If no element is found,

  32057. ** a pointer to a static null element with HashElem.data==0 is returned.

  32058. ** If pH is not NULL, then the hash for this key is written to *pH.

  32059. */

  32060. static HashElem *findElementWithHash(

  32061.   const Hash *pH,     /* The pH to be searched */

  32062.   const char *pKey,   /* The key we are searching for */

  32063.   unsigned int *pHash /* Write the hash value here */

  32064. ){

  32065.   HashElem *elem;                /* Used to loop thru the element list */

  32066.   unsigned int count;            /* Number of elements left to test */

  32067.   unsigned int h;                /* The computed hash */

  32068.   static HashElem nullElement = { 0, 0, 0, 0 };

  32069. 

  32070.   if( pH->ht ){   /*OPTIMIZATION-IF-TRUE*/

  32071.     struct _ht *pEntry;

  32072.     h = strHash(pKey) % pH->htsize;

  32073.     pEntry = &pH->ht[h];

  32074.     elem = pEntry->chain;

  32075.     count = pEntry->count;

  32076.   }else{

  32077.     h = 0;

  32078.     elem = pH->first;

  32079.     count = pH->count;

  32080.   }

  32081.   if( pHash ) *pHash = h;

  32082.   while( count-- ){

  32083.     assert( elem!=0 );

  32084.     if( sqlite3StrICmp(elem->pKey,pKey)==0 ){ 

  32085.       return elem;

  32086.     }

  32087.     elem = elem->next;

  32088.   }

  32089.   return &nullElement;

  32090. }

  32091. 

  32092. /* Remove a single entry from the hash table given a pointer to that

  32093. ** element and a hash on the element's key.

  32094. */

  32095. static void removeElementGivenHash(

  32096.   Hash *pH,         /* The pH containing "elem" */

  32097.   HashElem* elem,   /* The element to be removed from the pH */

  32098.   unsigned int h    /* Hash value for the element */

  32099. ){

  32100.   struct _ht *pEntry;

  32101.   if( elem->prev ){

  32102.     elem->prev->next = elem->next; 

  32103.   }else{

  32104.     pH->first = elem->next;

  32105.   }

  32106.   if( elem->next ){

  32107.     elem->next->prev = elem->prev;

  32108.   }

  32109.   if( pH->ht ){

  32110.     pEntry = &pH->ht[h];

  32111.     if( pEntry->chain==elem ){

  32112.       pEntry->chain = elem->next;

  32113.     }

  32114.     assert( pEntry->count>0 );

  32115.     pEntry->count--;

  32116.   }

  32117.   sqlite3_free( elem );

  32118.   pH->count--;

  32119.   if( pH->count==0 ){

  32120.     assert( pH->first==0 );

  32121.     assert( pH->count==0 );

  32122.     sqlite3HashClear(pH);

  32123.   }

  32124. }

  32125. 

  32126. /* Attempt to locate an element of the hash table pH with a key

  32127. ** that matches pKey.  Return the data for this element if it is

  32128. ** found, or NULL if there is no match.

  32129. */

  32130. SQLITE_PRIVATE void *sqlite3HashFind(const Hash *pH, const char *pKey){

  32131.   assert( pH!=0 );

  32132.   assert( pKey!=0 );

  32133.   return findElementWithHash(pH, pKey, 0)->data;

  32134. }

  32135. 

  32136. /* Insert an element into the hash table pH.  The key is pKey

  32137. ** and the data is "data".

  32138. **

  32139. ** If no element exists with a matching key, then a new

  32140. ** element is created and NULL is returned.

  32141. **

  32142. ** If another element already exists with the same key, then the

  32143. ** new data replaces the old data and the old data is returned.

  32144. ** The key is not copied in this instance.  If a malloc fails, then

  32145. ** the new data is returned and the hash table is unchanged.

  32146. **

  32147. ** If the "data" parameter to this function is NULL, then the

  32148. ** element corresponding to "key" is removed from the hash table.

  32149. */

  32150. SQLITE_PRIVATE void *sqlite3HashInsert(Hash *pH, const char *pKey, void *data){

  32151.   unsigned int h;       /* the hash of the key modulo hash table size */

  32152.   HashElem *elem;       /* Used to loop thru the element list */

  32153.   HashElem *new_elem;   /* New element added to the pH */

  32154. 

  32155.   assert( pH!=0 );

  32156.   assert( pKey!=0 );

  32157.   elem = findElementWithHash(pH,pKey,&h);

  32158.   if( elem->data ){

  32159.     void *old_data = elem->data;

  32160.     if( data==0 ){

  32161.       removeElementGivenHash(pH,elem,h);

  32162.     }else{

  32163.       elem->data = data;

  32164.       elem->pKey = pKey;

  32165.     }

  32166.     return old_data;

  32167.   }

  32168.   if( data==0 ) return 0;

  32169.   new_elem = (HashElem*)sqlite3Malloc( sizeof(HashElem) );

  32170.   if( new_elem==0 ) return data;

  32171.   new_elem->pKey = pKey;

  32172.   new_elem->data = data;

  32173.   pH->count++;

  32174.   if( pH->count>=10 && pH->count > 2*pH->htsize ){

  32175.     if( rehash(pH, pH->count*2) ){

  32176.       assert( pH->htsize>0 );

  32177.       h = strHash(pKey) % pH->htsize;

  32178.     }

  32179.   }

  32180.   insertElement(pH, pH->ht ? &pH->ht[h] : 0, new_elem);

  32181.   return 0;

  32182. }

  32183. 

  32184. /************** End of hash.c ************************************************/

  32185. /************** Begin file opcodes.c *****************************************/

  32186. /* Automatically generated.  Do not edit */

  32187. /* See the tool/mkopcodec.tcl script for details. */

  32188. #if !defined(SQLITE_OMIT_EXPLAIN) \

  32189.  || defined(VDBE_PROFILE) \

  32190.  || defined(SQLITE_DEBUG)

  32191. #if defined(SQLITE_ENABLE_EXPLAIN_COMMENTS) || defined(SQLITE_DEBUG)

  32192. # define OpHelp(X) "\0" X

  32193. #else

  32194. # define OpHelp(X)

  32195. #endif

  32196. SQLITE_PRIVATE const char *sqlite3OpcodeName(int i){

  32197.  static const char *const azName[] = {

  32198.     /*   0 */ "Savepoint"        OpHelp(""),

  32199.     /*   1 */ "AutoCommit"       OpHelp(""),

  32200.     /*   2 */ "Transaction"      OpHelp(""),

  32201.     /*   3 */ "SorterNext"       OpHelp(""),

  32202.     /*   4 */ "Prev"             OpHelp(""),

  32203.     /*   5 */ "Next"             OpHelp(""),

  32204.     /*   6 */ "Checkpoint"       OpHelp(""),

  32205.     /*   7 */ "JournalMode"      OpHelp(""),

  32206.     /*   8 */ "Vacuum"           OpHelp(""),

  32207.     /*   9 */ "VFilter"          OpHelp("iplan=r[P3] zplan='P4'"),

  32208.     /*  10 */ "VUpdate"          OpHelp("data=r[P3@P2]"),

  32209.     /*  11 */ "Goto"             OpHelp(""),

  32210.     /*  12 */ "Gosub"            OpHelp(""),

  32211.     /*  13 */ "InitCoroutine"    OpHelp(""),

  32212.     /*  14 */ "Yield"            OpHelp(""),

  32213.     /*  15 */ "MustBeInt"        OpHelp(""),

  32214.     /*  16 */ "Jump"             OpHelp(""),

  32215.     /*  17 */ "Once"             OpHelp(""),

  32216.     /*  18 */ "If"               OpHelp(""),

  32217.     /*  19 */ "Not"              OpHelp("r[P2]= !r[P1]"),

  32218.     /*  20 */ "IfNot"            OpHelp(""),

  32219.     /*  21 */ "IfNullRow"        OpHelp("if P1.nullRow then r[P3]=NULL, goto P2"),

  32220.     /*  22 */ "SeekLT"           OpHelp("key=r[P3@P4]"),

  32221.     /*  23 */ "SeekLE"           OpHelp("key=r[P3@P4]"),

  32222.     /*  24 */ "SeekGE"           OpHelp("key=r[P3@P4]"),

  32223.     /*  25 */ "SeekGT"           OpHelp("key=r[P3@P4]"),

  32224.     /*  26 */ "IfNoHope"         OpHelp("key=r[P3@P4]"),

  32225.     /*  27 */ "NoConflict"       OpHelp("key=r[P3@P4]"),

  32226.     /*  28 */ "NotFound"         OpHelp("key=r[P3@P4]"),

  32227.     /*  29 */ "Found"            OpHelp("key=r[P3@P4]"),

  32228.     /*  30 */ "SeekRowid"        OpHelp("intkey=r[P3]"),

  32229.     /*  31 */ "NotExists"        OpHelp("intkey=r[P3]"),

  32230.     /*  32 */ "Last"             OpHelp(""),

  32231.     /*  33 */ "IfSmaller"        OpHelp(""),

  32232.     /*  34 */ "SorterSort"       OpHelp(""),

  32233.     /*  35 */ "Sort"             OpHelp(""),

  32234.     /*  36 */ "Rewind"           OpHelp(""),

  32235.     /*  37 */ "IdxLE"            OpHelp("key=r[P3@P4]"),

  32236.     /*  38 */ "IdxGT"            OpHelp("key=r[P3@P4]"),

  32237.     /*  39 */ "IdxLT"            OpHelp("key=r[P3@P4]"),

  32238.     /*  40 */ "IdxGE"            OpHelp("key=r[P3@P4]"),

  32239.     /*  41 */ "RowSetRead"       OpHelp("r[P3]=rowset(P1)"),

  32240.     /*  42 */ "RowSetTest"       OpHelp("if r[P3] in rowset(P1) goto P2"),

  32241.     /*  43 */ "Or"               OpHelp("r[P3]=(r[P1] || r[P2])"),

  32242.     /*  44 */ "And"              OpHelp("r[P3]=(r[P1] && r[P2])"),

  32243.     /*  45 */ "Program"          OpHelp(""),

  32244.     /*  46 */ "FkIfZero"         OpHelp("if fkctr[P1]==0 goto P2"),

  32245.     /*  47 */ "IfPos"            OpHelp("if r[P1]>0 then r[P1]-=P3, goto P2"),

  32246.     /*  48 */ "IfNotZero"        OpHelp("if r[P1]!=0 then r[P1]--, goto P2"),

  32247.     /*  49 */ "DecrJumpZero"     OpHelp("if (--r[P1])==0 goto P2"),

  32248.     /*  50 */ "IsNull"           OpHelp("if r[P1]==NULL goto P2"),

  32249.     /*  51 */ "NotNull"          OpHelp("if r[P1]!=NULL goto P2"),

  32250.     /*  52 */ "Ne"               OpHelp("IF r[P3]!=r[P1]"),

  32251.     /*  53 */ "Eq"               OpHelp("IF r[P3]==r[P1]"),

  32252.     /*  54 */ "Gt"               OpHelp("IF r[P3]>r[P1]"),

  32253.     /*  55 */ "Le"               OpHelp("IF r[P3]<=r[P1]"),

  32254.     /*  56 */ "Lt"               OpHelp("IF r[P3]<r[P1]"),

  32255.     /*  57 */ "Ge"               OpHelp("IF r[P3]>=r[P1]"),

  32256.     /*  58 */ "ElseNotEq"        OpHelp(""),

  32257.     /*  59 */ "IncrVacuum"       OpHelp(""),

  32258.     /*  60 */ "VNext"            OpHelp(""),

  32259.     /*  61 */ "Init"             OpHelp("Start at P2"),

  32260.     /*  62 */ "PureFunc0"        OpHelp(""),

  32261.     /*  63 */ "Function0"        OpHelp("r[P3]=func(r[P2@P5])"),

  32262.     /*  64 */ "PureFunc"         OpHelp(""),

  32263.     /*  65 */ "Function"         OpHelp("r[P3]=func(r[P2@P5])"),

  32264.     /*  66 */ "Return"           OpHelp(""),

  32265.     /*  67 */ "EndCoroutine"     OpHelp(""),

  32266.     /*  68 */ "HaltIfNull"       OpHelp("if r[P3]=null halt"),

  32267.     /*  69 */ "Halt"             OpHelp(""),

  32268.     /*  70 */ "Integer"          OpHelp("r[P2]=P1"),

  32269.     /*  71 */ "Int64"            OpHelp("r[P2]=P4"),

  32270.     /*  72 */ "String"           OpHelp("r[P2]='P4' (len=P1)"),

  32271.     /*  73 */ "Null"             OpHelp("r[P2..P3]=NULL"),

  32272.     /*  74 */ "SoftNull"         OpHelp("r[P1]=NULL"),

  32273.     /*  75 */ "Blob"             OpHelp("r[P2]=P4 (len=P1)"),

  32274.     /*  76 */ "Variable"         OpHelp("r[P2]=parameter(P1,P4)"),

  32275.     /*  77 */ "Move"             OpHelp("r[P2@P3]=r[P1@P3]"),

  32276.     /*  78 */ "Copy"             OpHelp("r[P2@P3+1]=r[P1@P3+1]"),

  32277.     /*  79 */ "SCopy"            OpHelp("r[P2]=r[P1]"),

  32278.     /*  80 */ "IntCopy"          OpHelp("r[P2]=r[P1]"),

  32279.     /*  81 */ "ResultRow"        OpHelp("output=r[P1@P2]"),

  32280.     /*  82 */ "CollSeq"          OpHelp(""),

  32281.     /*  83 */ "AddImm"           OpHelp("r[P1]=r[P1]+P2"),

  32282.     /*  84 */ "RealAffinity"     OpHelp(""),

  32283.     /*  85 */ "Cast"             OpHelp("affinity(r[P1])"),

  32284.     /*  86 */ "Permutation"      OpHelp(""),

  32285.     /*  87 */ "Compare"          OpHelp("r[P1@P3] <-> r[P2@P3]"),

  32286.     /*  88 */ "IsTrue"           OpHelp("r[P2] = coalesce(r[P1]==TRUE,P3) ^ P4"),

  32287.     /*  89 */ "Offset"           OpHelp("r[P3] = sqlite_offset(P1)"),

  32288.     /*  90 */ "Column"           OpHelp("r[P3]=PX"),

  32289.     /*  91 */ "Affinity"         OpHelp("affinity(r[P1@P2])"),

  32290.     /*  92 */ "MakeRecord"       OpHelp("r[P3]=mkrec(r[P1@P2])"),

  32291.     /*  93 */ "Count"            OpHelp("r[P2]=count()"),

  32292.     /*  94 */ "ReadCookie"       OpHelp(""),

  32293.     /*  95 */ "SetCookie"        OpHelp(""),

  32294.     /*  96 */ "BitAnd"           OpHelp("r[P3]=r[P1]&r[P2]"),

  32295.     /*  97 */ "BitOr"            OpHelp("r[P3]=r[P1]|r[P2]"),

  32296.     /*  98 */ "ShiftLeft"        OpHelp("r[P3]=r[P2]<<r[P1]"),

  32297.     /*  99 */ "ShiftRight"       OpHelp("r[P3]=r[P2]>>r[P1]"),

  32298.     /* 100 */ "Add"              OpHelp("r[P3]=r[P1]+r[P2]"),

  32299.     /* 101 */ "Subtract"         OpHelp("r[P3]=r[P2]-r[P1]"),

  32300.     /* 102 */ "Multiply"         OpHelp("r[P3]=r[P1]*r[P2]"),

  32301.     /* 103 */ "Divide"           OpHelp("r[P3]=r[P2]/r[P1]"),

  32302.     /* 104 */ "Remainder"        OpHelp("r[P3]=r[P2]%r[P1]"),

  32303.     /* 105 */ "Concat"           OpHelp("r[P3]=r[P2]+r[P1]"),

  32304.     /* 106 */ "ReopenIdx"        OpHelp("root=P2 iDb=P3"),

  32305.     /* 107 */ "BitNot"           OpHelp("r[P2]= ~r[P1]"),

  32306.     /* 108 */ "OpenRead"         OpHelp("root=P2 iDb=P3"),

  32307.     /* 109 */ "OpenWrite"        OpHelp("root=P2 iDb=P3"),

  32308.     /* 110 */ "String8"          OpHelp("r[P2]='P4'"),

  32309.     /* 111 */ "OpenDup"          OpHelp(""),

  32310.     /* 112 */ "OpenAutoindex"    OpHelp("nColumn=P2"),

  32311.     /* 113 */ "OpenEphemeral"    OpHelp("nColumn=P2"),

  32312.     /* 114 */ "SorterOpen"       OpHelp(""),

  32313.     /* 115 */ "SequenceTest"     OpHelp("if( cursor[P1].ctr++ ) pc = P2"),

  32314.     /* 116 */ "OpenPseudo"       OpHelp("P3 columns in r[P2]"),

  32315.     /* 117 */ "Close"            OpHelp(""),

  32316.     /* 118 */ "ColumnsUsed"      OpHelp(""),

  32317.     /* 119 */ "SeekHit"          OpHelp("seekHit=P2"),

  32318.     /* 120 */ "Sequence"         OpHelp("r[P2]=cursor[P1].ctr++"),

  32319.     /* 121 */ "NewRowid"         OpHelp("r[P2]=rowid"),

  32320.     /* 122 */ "Insert"           OpHelp("intkey=r[P3] data=r[P2]"),

  32321.     /* 123 */ "Delete"           OpHelp(""),

  32322.     /* 124 */ "ResetCount"       OpHelp(""),

  32323.     /* 125 */ "SorterCompare"    OpHelp("if key(P1)!=trim(r[P3],P4) goto P2"),

  32324.     /* 126 */ "SorterData"       OpHelp("r[P2]=data"),

  32325.     /* 127 */ "RowData"          OpHelp("r[P2]=data"),

  32326.     /* 128 */ "Rowid"            OpHelp("r[P2]=rowid"),

  32327.     /* 129 */ "NullRow"          OpHelp(""),

  32328.     /* 130 */ "SeekEnd"          OpHelp(""),

  32329.     /* 131 */ "SorterInsert"     OpHelp("key=r[P2]"),

  32330.     /* 132 */ "IdxInsert"        OpHelp("key=r[P2]"),

  32331.     /* 133 */ "IdxDelete"        OpHelp("key=r[P2@P3]"),

  32332.     /* 134 */ "DeferredSeek"     OpHelp("Move P3 to P1.rowid if needed"),

  32333.     /* 135 */ "IdxRowid"         OpHelp("r[P2]=rowid"),

  32334.     /* 136 */ "Destroy"          OpHelp(""),

  32335.     /* 137 */ "Clear"            OpHelp(""),

  32336.     /* 138 */ "ResetSorter"      OpHelp(""),

  32337.     /* 139 */ "CreateBtree"      OpHelp("r[P2]=root iDb=P1 flags=P3"),

  32338.     /* 140 */ "SqlExec"          OpHelp(""),

  32339.     /* 141 */ "ParseSchema"      OpHelp(""),

  32340.     /* 142 */ "LoadAnalysis"     OpHelp(""),

  32341.     /* 143 */ "DropTable"        OpHelp(""),

  32342.     /* 144 */ "DropIndex"        OpHelp(""),

  32343.     /* 145 */ "Real"             OpHelp("r[P2]=P4"),

  32344.     /* 146 */ "DropTrigger"      OpHelp(""),

  32345.     /* 147 */ "IntegrityCk"      OpHelp(""),

  32346.     /* 148 */ "RowSetAdd"        OpHelp("rowset(P1)=r[P2]"),

  32347.     /* 149 */ "Param"            OpHelp(""),

  32348.     /* 150 */ "FkCounter"        OpHelp("fkctr[P1]+=P2"),

  32349.     /* 151 */ "MemMax"           OpHelp("r[P1]=max(r[P1],r[P2])"),

  32350.     /* 152 */ "OffsetLimit"      OpHelp("if r[P1]>0 then r[P2]=r[P1]+max(0,r[P3]) else r[P2]=(-1)"),

  32351.     /* 153 */ "AggInverse"       OpHelp("accum=r[P3] inverse(r[P2@P5])"),

  32352.     /* 154 */ "AggStep"          OpHelp("accum=r[P3] step(r[P2@P5])"),

  32353.     /* 155 */ "AggStep1"         OpHelp("accum=r[P3] step(r[P2@P5])"),

  32354.     /* 156 */ "AggValue"         OpHelp("r[P3]=value N=P2"),

  32355.     /* 157 */ "AggFinal"         OpHelp("accum=r[P1] N=P2"),

  32356.     /* 158 */ "Expire"           OpHelp(""),

  32357.     /* 159 */ "TableLock"        OpHelp("iDb=P1 root=P2 write=P3"),

  32358.     /* 160 */ "VBegin"           OpHelp(""),

  32359.     /* 161 */ "VCreate"          OpHelp(""),

  32360.     /* 162 */ "VDestroy"         OpHelp(""),

  32361.     /* 163 */ "VOpen"            OpHelp(""),

  32362.     /* 164 */ "VColumn"          OpHelp("r[P3]=vcolumn(P2)"),

  32363.     /* 165 */ "VRename"          OpHelp(""),

  32364.     /* 166 */ "Pagecount"        OpHelp(""),

  32365.     /* 167 */ "MaxPgcnt"         OpHelp(""),

  32366.     /* 168 */ "Trace"            OpHelp(""),

  32367.     /* 169 */ "CursorHint"       OpHelp(""),

  32368.     /* 170 */ "Noop"             OpHelp(""),

  32369.     /* 171 */ "Explain"          OpHelp(""),

  32370.     /* 172 */ "Abortable"        OpHelp(""),

  32371.   };

  32372.   return azName[i];

  32373. }

  32374. #endif

  32375. 

  32376. /************** End of opcodes.c *********************************************/

  32377. /************** Begin file os_unix.c *****************************************/

  32378. /*

  32379. ** 2004 May 22

  32380. **

  32381. ** The author disclaims copyright to this source code.  In place of

  32382. ** a legal notice, here is a blessing:

  32383. **

  32384. **    May you do good and not evil.

  32385. **    May you find forgiveness for yourself and forgive others.

  32386. **    May you share freely, never taking more than you give.

  32387. **

  32388. ******************************************************************************

  32389. **

  32390. ** This file contains the VFS implementation for unix-like operating systems

  32391. ** include Linux, MacOSX, *BSD, QNX, VxWorks, AIX, HPUX, and others.

  32392. **

  32393. ** There are actually several different VFS implementations in this file.

  32394. ** The differences are in the way that file locking is done.  The default

  32395. ** implementation uses Posix Advisory Locks.  Alternative implementations

  32396. ** use flock(), dot-files, various proprietary locking schemas, or simply

  32397. ** skip locking all together.

  32398. **

  32399. ** This source file is organized into divisions where the logic for various

  32400. ** subfunctions is contained within the appropriate division.  PLEASE

  32401. ** KEEP THE STRUCTURE OF THIS FILE INTACT.  New code should be placed

  32402. ** in the correct division and should be clearly labeled.

  32403. **

  32404. ** The layout of divisions is as follows:

  32405. **

  32406. **   *  General-purpose declarations and utility functions.

  32407. **   *  Unique file ID logic used by VxWorks.

  32408. **   *  Various locking primitive implementations (all except proxy locking):

  32409. **      + for Posix Advisory Locks

  32410. **      + for no-op locks

  32411. **      + for dot-file locks

  32412. **      + for flock() locking

  32413. **      + for named semaphore locks (VxWorks only)

  32414. **      + for AFP filesystem locks (MacOSX only)

  32415. **   *  sqlite3_file methods not associated with locking.

  32416. **   *  Definitions of sqlite3_io_methods objects for all locking

  32417. **      methods plus "finder" functions for each locking method.

  32418. **   *  sqlite3_vfs method implementations.

  32419. **   *  Locking primitives for the proxy uber-locking-method. (MacOSX only)

  32420. **   *  Definitions of sqlite3_vfs objects for all locking methods

  32421. **      plus implementations of sqlite3_os_init() and sqlite3_os_end().

  32422. */

  32423. /* #include "sqliteInt.h" */

  32424. #if SQLITE_OS_UNIX              /* This file is used on unix only */

  32425. 

  32426. /*

  32427. ** There are various methods for file locking used for concurrency

  32428. ** control:

  32429. **

  32430. **   1. POSIX locking (the default),

  32431. **   2. No locking,

  32432. **   3. Dot-file locking,

  32433. **   4. flock() locking,

  32434. **   5. AFP locking (OSX only),

  32435. **   6. Named POSIX semaphores (VXWorks only),

  32436. **   7. proxy locking. (OSX only)

  32437. **

  32438. ** Styles 4, 5, and 7 are only available of SQLITE_ENABLE_LOCKING_STYLE

  32439. ** is defined to 1.  The SQLITE_ENABLE_LOCKING_STYLE also enables automatic

  32440. ** selection of the appropriate locking style based on the filesystem

  32441. ** where the database is located.  

  32442. */

  32443. #if !defined(SQLITE_ENABLE_LOCKING_STYLE)

  32444. #  if defined(__APPLE__)

  32445. #    define SQLITE_ENABLE_LOCKING_STYLE 1

  32446. #  else

  32447. #    define SQLITE_ENABLE_LOCKING_STYLE 0

  32448. #  endif

  32449. #endif

  32450. 

  32451. /* Use pread() and pwrite() if they are available */

  32452. #if defined(__APPLE__)

  32453. # define HAVE_PREAD 1

  32454. # define HAVE_PWRITE 1

  32455. #endif

  32456. #if defined(HAVE_PREAD64) && defined(HAVE_PWRITE64)

  32457. # undef USE_PREAD

  32458. # define USE_PREAD64 1

  32459. #elif defined(HAVE_PREAD) && defined(HAVE_PWRITE)

  32460. # undef USE_PREAD64

  32461. # define USE_PREAD 1

  32462. #endif

  32463. 

  32464. /*

  32465. ** standard include files.

  32466. */

  32467. #include <sys/types.h>

  32468. #include <sys/stat.h>

  32469. #include <fcntl.h>

  32470. #include <sys/ioctl.h>

  32471. #include <unistd.h>

  32472. /* #include <time.h> */

  32473. #include <sys/time.h>

  32474. #include <errno.h>

  32475. #if !defined(SQLITE_OMIT_WAL) || SQLITE_MAX_MMAP_SIZE>0

  32476. # include <sys/mman.h>

  32477. #endif

  32478. 

  32479. #if SQLITE_ENABLE_LOCKING_STYLE

  32480. /* # include <sys/ioctl.h> */

  32481. # include <sys/file.h>

  32482. # include <sys/param.h>

  32483. #endif /* SQLITE_ENABLE_LOCKING_STYLE */

  32484. 

  32485. #if defined(__APPLE__) && ((__MAC_OS_X_VERSION_MIN_REQUIRED > 1050) || \

  32486.                            (__IPHONE_OS_VERSION_MIN_REQUIRED > 2000))

  32487. #  if (!defined(TARGET_OS_EMBEDDED) || (TARGET_OS_EMBEDDED==0)) \

  32488.        && (!defined(TARGET_IPHONE_SIMULATOR) || (TARGET_IPHONE_SIMULATOR==0))

  32489. #    define HAVE_GETHOSTUUID 1

  32490. #  else

  32491. #    warning "gethostuuid() is disabled."

  32492. #  endif

  32493. #endif

  32494. 

  32495. 

  32496. #if OS_VXWORKS

  32497. /* # include <sys/ioctl.h> */

  32498. # include <semaphore.h>

  32499. # include <limits.h>

  32500. #endif /* OS_VXWORKS */

  32501. 

  32502. #if defined(__APPLE__) || SQLITE_ENABLE_LOCKING_STYLE

  32503. # include <sys/mount.h>

  32504. #endif

  32505. 

  32506. #ifdef HAVE_UTIME

  32507. # include <utime.h>

  32508. #endif

  32509. 

  32510. /*

  32511. ** Allowed values of unixFile.fsFlags

  32512. */

  32513. #define SQLITE_FSFLAGS_IS_MSDOS     0x1

  32514. 

  32515. /*

  32516. ** If we are to be thread-safe, include the pthreads header.

  32517. */

  32518. #if SQLITE_THREADSAFE

  32519. /* # include <pthread.h> */

  32520. #endif

  32521. 

  32522. /*

  32523. ** Default permissions when creating a new file

  32524. */

  32525. #ifndef SQLITE_DEFAULT_FILE_PERMISSIONS

  32526. # define SQLITE_DEFAULT_FILE_PERMISSIONS 0644

  32527. #endif

  32528. 

  32529. /*

  32530. ** Default permissions when creating auto proxy dir

  32531. */

  32532. #ifndef SQLITE_DEFAULT_PROXYDIR_PERMISSIONS

  32533. # define SQLITE_DEFAULT_PROXYDIR_PERMISSIONS 0755

  32534. #endif

  32535. 

  32536. /*

  32537. ** Maximum supported path-length.

  32538. */

  32539. #define MAX_PATHNAME 512

  32540. 

  32541. /*

  32542. ** Maximum supported symbolic links

  32543. */

  32544. #define SQLITE_MAX_SYMLINKS 100

  32545. 

  32546. /* Always cast the getpid() return type for compatibility with

  32547. ** kernel modules in VxWorks. */

  32548. #define osGetpid(X) (pid_t)getpid()

  32549. 

  32550. /*

  32551. ** Only set the lastErrno if the error code is a real error and not 

  32552. ** a normal expected return code of SQLITE_BUSY or SQLITE_OK

  32553. */

  32554. #define IS_LOCK_ERROR(x)  ((x != SQLITE_OK) && (x != SQLITE_BUSY))

  32555. 

  32556. /* Forward references */

  32557. typedef struct unixShm unixShm;               /* Connection shared memory */

  32558. typedef struct unixShmNode unixShmNode;       /* Shared memory instance */

  32559. typedef struct unixInodeInfo unixInodeInfo;   /* An i-node */

  32560. typedef struct UnixUnusedFd UnixUnusedFd;     /* An unused file descriptor */

  32561. 

  32562. /*

  32563. ** Sometimes, after a file handle is closed by SQLite, the file descriptor

  32564. ** cannot be closed immediately. In these cases, instances of the following

  32565. ** structure are used to store the file descriptor while waiting for an

  32566. ** opportunity to either close or reuse it.

  32567. */

  32568. struct UnixUnusedFd {

  32569.   int fd;                   /* File descriptor to close */

  32570.   int flags;                /* Flags this file descriptor was opened with */

  32571.   UnixUnusedFd *pNext;      /* Next unused file descriptor on same file */

  32572. };

  32573. 

  32574. /*

  32575. ** The unixFile structure is subclass of sqlite3_file specific to the unix

  32576. ** VFS implementations.

  32577. */

  32578. typedef struct unixFile unixFile;

  32579. struct unixFile {

  32580.   sqlite3_io_methods const *pMethod;  /* Always the first entry */

  32581.   sqlite3_vfs *pVfs;                  /* The VFS that created this unixFile */

  32582.   unixInodeInfo *pInode;              /* Info about locks on this inode */

  32583.   int h;                              /* The file descriptor */

  32584.   unsigned char eFileLock;            /* The type of lock held on this fd */

  32585.   unsigned short int ctrlFlags;       /* Behavioral bits.  UNIXFILE_* flags */

  32586.   int lastErrno;                      /* The unix errno from last I/O error */

  32587.   void *lockingContext;               /* Locking style specific state */

  32588.   UnixUnusedFd *pPreallocatedUnused;  /* Pre-allocated UnixUnusedFd */

  32589.   const char *zPath;                  /* Name of the file */

  32590.   unixShm *pShm;                      /* Shared memory segment information */

  32591.   int szChunk;                        /* Configured by FCNTL_CHUNK_SIZE */

  32592. #if SQLITE_MAX_MMAP_SIZE>0

  32593.   int nFetchOut;                      /* Number of outstanding xFetch refs */

  32594.   sqlite3_int64 mmapSize;             /* Usable size of mapping at pMapRegion */

  32595.   sqlite3_int64 mmapSizeActual;       /* Actual size of mapping at pMapRegion */

  32596.   sqlite3_int64 mmapSizeMax;          /* Configured FCNTL_MMAP_SIZE value */

  32597.   void *pMapRegion;                   /* Memory mapped region */

  32598. #endif

  32599.   int sectorSize;                     /* Device sector size */

  32600.   int deviceCharacteristics;          /* Precomputed device characteristics */

  32601. #if SQLITE_ENABLE_LOCKING_STYLE

  32602.   int openFlags;                      /* The flags specified at open() */

  32603. #endif

  32604. #if SQLITE_ENABLE_LOCKING_STYLE || defined(__APPLE__)

  32605.   unsigned fsFlags;                   /* cached details from statfs() */

  32606. #endif

  32607. #ifdef SQLITE_ENABLE_SETLK_TIMEOUT

  32608.   unsigned iBusyTimeout;              /* Wait this many millisec on locks */

  32609. #endif

  32610. #if OS_VXWORKS

  32611.   struct vxworksFileId *pId;          /* Unique file ID */

  32612. #endif

  32613. #ifdef SQLITE_DEBUG

  32614.   /* The next group of variables are used to track whether or not the

  32615.   ** transaction counter in bytes 24-27 of database files are updated

  32616.   ** whenever any part of the database changes.  An assertion fault will

  32617.   ** occur if a file is updated without also updating the transaction

  32618.   ** counter.  This test is made to avoid new problems similar to the

  32619.   ** one described by ticket #3584. 

  32620.   */

  32621.   unsigned char transCntrChng;   /* True if the transaction counter changed */

  32622.   unsigned char dbUpdate;        /* True if any part of database file changed */

  32623.   unsigned char inNormalWrite;   /* True if in a normal write operation */

  32624. 

  32625. #endif

  32626. 

  32627. #ifdef SQLITE_TEST

  32628.   /* In test mode, increase the size of this structure a bit so that 

  32629.   ** it is larger than the struct CrashFile defined in test6.c.

  32630.   */

  32631.   char aPadding[32];

  32632. #endif

  32633. };

  32634. 

  32635. /* This variable holds the process id (pid) from when the xRandomness()

  32636. ** method was called.  If xOpen() is called from a different process id,

  32637. ** indicating that a fork() has occurred, the PRNG will be reset.

  32638. */

  32639. static pid_t randomnessPid = 0;

  32640. 

  32641. /*

  32642. ** Allowed values for the unixFile.ctrlFlags bitmask:

  32643. */

  32644. #define UNIXFILE_EXCL        0x01     /* Connections from one process only */

  32645. #define UNIXFILE_RDONLY      0x02     /* Connection is read only */

  32646. #define UNIXFILE_PERSIST_WAL 0x04     /* Persistent WAL mode */

  32647. #ifndef SQLITE_DISABLE_DIRSYNC

  32648. # define UNIXFILE_DIRSYNC    0x08     /* Directory sync needed */

  32649. #else

  32650. # define UNIXFILE_DIRSYNC    0x00

  32651. #endif

  32652. #define UNIXFILE_PSOW        0x10     /* SQLITE_IOCAP_POWERSAFE_OVERWRITE */

  32653. #define UNIXFILE_DELETE      0x20     /* Delete on close */

  32654. #define UNIXFILE_URI         0x40     /* Filename might have query parameters */

  32655. #define UNIXFILE_NOLOCK      0x80     /* Do no file locking */

  32656. 

  32657. /*

  32658. ** Include code that is common to all os_*.c files

  32659. */

  32660. /************** Include os_common.h in the middle of os_unix.c ***************/

  32661. /************** Begin file os_common.h ***************************************/

  32662. /*

  32663. ** 2004 May 22

  32664. **

  32665. ** The author disclaims copyright to this source code.  In place of

  32666. ** a legal notice, here is a blessing:

  32667. **

  32668. **    May you do good and not evil.

  32669. **    May you find forgiveness for yourself and forgive others.

  32670. **    May you share freely, never taking more than you give.

  32671. **

  32672. ******************************************************************************

  32673. **

  32674. ** This file contains macros and a little bit of code that is common to

  32675. ** all of the platform-specific files (os_*.c) and is #included into those

  32676. ** files.

  32677. **

  32678. ** This file should be #included by the os_*.c files only.  It is not a

  32679. ** general purpose header file.

  32680. */

  32681. #ifndef _OS_COMMON_H_

  32682. #define _OS_COMMON_H_

  32683. 

  32684. /*

  32685. ** At least two bugs have slipped in because we changed the MEMORY_DEBUG

  32686. ** macro to SQLITE_DEBUG and some older makefiles have not yet made the

  32687. ** switch.  The following code should catch this problem at compile-time.

  32688. */

  32689. #ifdef MEMORY_DEBUG

  32690. # error "The MEMORY_DEBUG macro is obsolete.  Use SQLITE_DEBUG instead."

  32691. #endif

  32692. 

  32693. /*

  32694. ** Macros for performance tracing.  Normally turned off.  Only works

  32695. ** on i486 hardware.

  32696. */

  32697. #ifdef SQLITE_PERFORMANCE_TRACE

  32698. 

  32699. /*

  32700. ** hwtime.h contains inline assembler code for implementing

  32701. ** high-performance timing routines.

  32702. */

  32703. /************** Include hwtime.h in the middle of os_common.h ****************/

  32704. /************** Begin file hwtime.h ******************************************/

  32705. /*

  32706. ** 2008 May 27

  32707. **

  32708. ** The author disclaims copyright to this source code.  In place of

  32709. ** a legal notice, here is a blessing:

  32710. **

  32711. **    May you do good and not evil.

  32712. **    May you find forgiveness for yourself and forgive others.

  32713. **    May you share freely, never taking more than you give.

  32714. **

  32715. ******************************************************************************

  32716. **

  32717. ** This file contains inline asm code for retrieving "high-performance"

  32718. ** counters for x86 class CPUs.

  32719. */

  32720. #ifndef SQLITE_HWTIME_H

  32721. #define SQLITE_HWTIME_H

  32722. 

  32723. /*

  32724. ** The following routine only works on pentium-class (or newer) processors.

  32725. ** It uses the RDTSC opcode to read the cycle count value out of the

  32726. ** processor and returns that value.  This can be used for high-res

  32727. ** profiling.

  32728. */

  32729. #if (defined(__GNUC__) || defined(_MSC_VER)) && \

  32730.       (defined(i386) || defined(__i386__) || defined(_M_IX86))

  32731. 

  32732.   #if defined(__GNUC__)

  32733. 

  32734.   __inline__ sqlite_uint64 sqlite3Hwtime(void){

  32735.      unsigned int lo, hi;

  32736.      __asm__ __volatile__ ("rdtsc" : "=a" (lo), "=d" (hi));

  32737.      return (sqlite_uint64)hi << 32 | lo;

  32738.   }

  32739. 

  32740.   #elif defined(_MSC_VER)

  32741. 

  32742.   __declspec(naked) __inline sqlite_uint64 __cdecl sqlite3Hwtime(void){

  32743.      __asm {

  32744.         rdtsc

  32745.         ret       ; return value at EDX:EAX

  32746.      }

  32747.   }

  32748. 

  32749.   #endif

  32750. 

  32751. #elif (defined(__GNUC__) && defined(__x86_64__))

  32752. 

  32753.   __inline__ sqlite_uint64 sqlite3Hwtime(void){

  32754.       unsigned long val;

  32755.       __asm__ __volatile__ ("rdtsc" : "=A" (val));

  32756.       return val;

  32757.   }

  32758.  

  32759. #elif (defined(__GNUC__) && defined(__ppc__))

  32760. 

  32761.   __inline__ sqlite_uint64 sqlite3Hwtime(void){

  32762.       unsigned long long retval;

  32763.       unsigned long junk;

  32764.       __asm__ __volatile__ ("\n\

  32765.           1:      mftbu   %1\n\

  32766.                   mftb    %L0\n\

  32767.                   mftbu   %0\n\

  32768.                   cmpw    %0,%1\n\

  32769.                   bne     1b"

  32770.                   : "=r" (retval), "=r" (junk));

  32771.       return retval;

  32772.   }

  32773. 

  32774. #else

  32775. 

  32776.   #error Need implementation of sqlite3Hwtime() for your platform.

  32777. 

  32778.   /*

  32779.   ** To compile without implementing sqlite3Hwtime() for your platform,

  32780.   ** you can remove the above #error and use the following

  32781.   ** stub function.  You will lose timing support for many

  32782.   ** of the debugging and testing utilities, but it should at

  32783.   ** least compile and run.

  32784.   */

  32785. SQLITE_PRIVATE   sqlite_uint64 sqlite3Hwtime(void){ return ((sqlite_uint64)0); }

  32786. 

  32787. #endif

  32788. 

  32789. #endif /* !defined(SQLITE_HWTIME_H) */

  32790. 

  32791. /************** End of hwtime.h **********************************************/

  32792. /************** Continuing where we left off in os_common.h ******************/

  32793. 

  32794. static sqlite_uint64 g_start;

  32795. static sqlite_uint64 g_elapsed;

  32796. #define TIMER_START       g_start=sqlite3Hwtime()

  32797. #define TIMER_END         g_elapsed=sqlite3Hwtime()-g_start

  32798. #define TIMER_ELAPSED     g_elapsed

  32799. #else

  32800. #define TIMER_START

  32801. #define TIMER_END

  32802. #define TIMER_ELAPSED     ((sqlite_uint64)0)

  32803. #endif

  32804. 

  32805. /*

  32806. ** If we compile with the SQLITE_TEST macro set, then the following block

  32807. ** of code will give us the ability to simulate a disk I/O error.  This

  32808. ** is used for testing the I/O recovery logic.

  32809. */

  32810. #if defined(SQLITE_TEST)

  32811. SQLITE_API extern int sqlite3_io_error_hit;

  32812. SQLITE_API extern int sqlite3_io_error_hardhit;

  32813. SQLITE_API extern int sqlite3_io_error_pending;

  32814. SQLITE_API extern int sqlite3_io_error_persist;

  32815. SQLITE_API extern int sqlite3_io_error_benign;

  32816. SQLITE_API extern int sqlite3_diskfull_pending;

  32817. SQLITE_API extern int sqlite3_diskfull;

  32818. #define SimulateIOErrorBenign(X) sqlite3_io_error_benign=(X)

  32819. #define SimulateIOError(CODE)  \

  32820.   if( (sqlite3_io_error_persist && sqlite3_io_error_hit) \

  32821.        || sqlite3_io_error_pending-- == 1 )  \

  32822.               { local_ioerr(); CODE; }

  32823. static void local_ioerr(){

  32824.   IOTRACE(("IOERR\n"));

  32825.   sqlite3_io_error_hit++;

  32826.   if( !sqlite3_io_error_benign ) sqlite3_io_error_hardhit++;

  32827. }

  32828. #define SimulateDiskfullError(CODE) \

  32829.    if( sqlite3_diskfull_pending ){ \

  32830.      if( sqlite3_diskfull_pending == 1 ){ \

  32831.        local_ioerr(); \

  32832.        sqlite3_diskfull = 1; \

  32833.        sqlite3_io_error_hit = 1; \

  32834.        CODE; \

  32835.      }else{ \

  32836.        sqlite3_diskfull_pending--; \

  32837.      } \

  32838.    }

  32839. #else

  32840. #define SimulateIOErrorBenign(X)

  32841. #define SimulateIOError(A)

  32842. #define SimulateDiskfullError(A)

  32843. #endif /* defined(SQLITE_TEST) */

  32844. 

  32845. /*

  32846. ** When testing, keep a count of the number of open files.

  32847. */

  32848. #if defined(SQLITE_TEST)

  32849. SQLITE_API extern int sqlite3_open_file_count;

  32850. #define OpenCounter(X)  sqlite3_open_file_count+=(X)

  32851. #else

  32852. #define OpenCounter(X)

  32853. #endif /* defined(SQLITE_TEST) */

  32854. 

  32855. #endif /* !defined(_OS_COMMON_H_) */

  32856. 

  32857. /************** End of os_common.h *******************************************/

  32858. /************** Continuing where we left off in os_unix.c ********************/

  32859. 

  32860. /*

  32861. ** Define various macros that are missing from some systems.

  32862. */

  32863. #ifndef O_LARGEFILE

  32864. # define O_LARGEFILE 0

  32865. #endif

  32866. #ifdef SQLITE_DISABLE_LFS

  32867. # undef O_LARGEFILE

  32868. # define O_LARGEFILE 0

  32869. #endif

  32870. #ifndef O_NOFOLLOW

  32871. # define O_NOFOLLOW 0

  32872. #endif

  32873. #ifndef O_BINARY

  32874. # define O_BINARY 0

  32875. #endif

  32876. 

  32877. /*

  32878. ** The threadid macro resolves to the thread-id or to 0.  Used for

  32879. ** testing and debugging only.

  32880. */

  32881. #if SQLITE_THREADSAFE

  32882. #define threadid pthread_self()

  32883. #else

  32884. #define threadid 0

  32885. #endif

  32886. 

  32887. /*

  32888. ** HAVE_MREMAP defaults to true on Linux and false everywhere else.

  32889. */

  32890. #if !defined(HAVE_MREMAP)

  32891. # if defined(__linux__) && defined(_GNU_SOURCE)

  32892. #  define HAVE_MREMAP 1

  32893. # else

  32894. #  define HAVE_MREMAP 0

  32895. # endif

  32896. #endif

  32897. 

  32898. /*

  32899. ** Explicitly call the 64-bit version of lseek() on Android. Otherwise, lseek()

  32900. ** is the 32-bit version, even if _FILE_OFFSET_BITS=64 is defined.

  32901. */

  32902. #ifdef __ANDROID__

  32903. # define lseek lseek64

  32904. #endif

  32905. 

  32906. #ifdef __linux__

  32907. /*

  32908. ** Linux-specific IOCTL magic numbers used for controlling F2FS

  32909. */

  32910. #define F2FS_IOCTL_MAGIC        0xf5

  32911. #define F2FS_IOC_START_ATOMIC_WRITE     _IO(F2FS_IOCTL_MAGIC, 1)

  32912. #define F2FS_IOC_COMMIT_ATOMIC_WRITE    _IO(F2FS_IOCTL_MAGIC, 2)

  32913. #define F2FS_IOC_START_VOLATILE_WRITE   _IO(F2FS_IOCTL_MAGIC, 3)

  32914. #define F2FS_IOC_ABORT_VOLATILE_WRITE   _IO(F2FS_IOCTL_MAGIC, 5)

  32915. #define F2FS_IOC_GET_FEATURES           _IOR(F2FS_IOCTL_MAGIC, 12, u32)

  32916. #define F2FS_FEATURE_ATOMIC_WRITE 0x0004

  32917. #endif /* __linux__ */

  32918. 

  32919. 

  32920. /*

  32921. ** Different Unix systems declare open() in different ways.  Same use

  32922. ** open(const char*,int,mode_t).  Others use open(const char*,int,...).

  32923. ** The difference is important when using a pointer to the function.

  32924. **

  32925. ** The safest way to deal with the problem is to always use this wrapper

  32926. ** which always has the same well-defined interface.

  32927. */

  32928. static int posixOpen(const char *zFile, int flags, int mode){

  32929.   return open(zFile, flags, mode);

  32930. }

  32931. 

  32932. /* Forward reference */

  32933. static int openDirectory(const char*, int*);

  32934. static int unixGetpagesize(void);

  32935. 

  32936. /*

  32937. ** Many system calls are accessed through pointer-to-functions so that

  32938. ** they may be overridden at runtime to facilitate fault injection during

  32939. ** testing and sandboxing.  The following array holds the names and pointers

  32940. ** to all overrideable system calls.

  32941. */

  32942. static struct unix_syscall {

  32943.   const char *zName;            /* Name of the system call */

  32944.   sqlite3_syscall_ptr pCurrent; /* Current value of the system call */

  32945.   sqlite3_syscall_ptr pDefault; /* Default value */

  32946. } aSyscall[] = {

  32947.   { "open",         (sqlite3_syscall_ptr)posixOpen,  0  },

  32948. #define osOpen      ((int(*)(const char*,int,int))aSyscall[0].pCurrent)

  32949. 

  32950.   { "close",        (sqlite3_syscall_ptr)close,      0  },

  32951. #define osClose     ((int(*)(int))aSyscall[1].pCurrent)

  32952. 

  32953.   { "access",       (sqlite3_syscall_ptr)access,     0  },

  32954. #define osAccess    ((int(*)(const char*,int))aSyscall[2].pCurrent)

  32955. 

  32956.   { "getcwd",       (sqlite3_syscall_ptr)getcwd,     0  },

  32957. #define osGetcwd    ((char*(*)(char*,size_t))aSyscall[3].pCurrent)

  32958. 

  32959.   { "stat",         (sqlite3_syscall_ptr)stat,       0  },

  32960. #define osStat      ((int(*)(const char*,struct stat*))aSyscall[4].pCurrent)

  32961. 

  32962. /*

  32963. ** The DJGPP compiler environment looks mostly like Unix, but it

  32964. ** lacks the fcntl() system call.  So redefine fcntl() to be something

  32965. ** that always succeeds.  This means that locking does not occur under

  32966. ** DJGPP.  But it is DOS - what did you expect?

  32967. */

  32968. #ifdef __DJGPP__

  32969.   { "fstat",        0,                 0  },

  32970. #define osFstat(a,b,c)    0

  32971. #else     

  32972.   { "fstat",        (sqlite3_syscall_ptr)fstat,      0  },

  32973. #define osFstat     ((int(*)(int,struct stat*))aSyscall[5].pCurrent)

  32974. #endif

  32975. 

  32976.   { "ftruncate",    (sqlite3_syscall_ptr)ftruncate,  0  },

  32977. #define osFtruncate ((int(*)(int,off_t))aSyscall[6].pCurrent)

  32978. 

  32979.   { "fcntl",        (sqlite3_syscall_ptr)fcntl,      0  },

  32980. #define osFcntl     ((int(*)(int,int,...))aSyscall[7].pCurrent)

  32981. 

  32982.   { "read",         (sqlite3_syscall_ptr)read,       0  },

  32983. #define osRead      ((ssize_t(*)(int,void*,size_t))aSyscall[8].pCurrent)

  32984. 

  32985. #if defined(USE_PREAD) || SQLITE_ENABLE_LOCKING_STYLE

  32986.   { "pread",        (sqlite3_syscall_ptr)pread,      0  },

  32987. #else

  32988.   { "pread",        (sqlite3_syscall_ptr)0,          0  },

  32989. #endif

  32990. #define osPread     ((ssize_t(*)(int,void*,size_t,off_t))aSyscall[9].pCurrent)

  32991. 

  32992. #if defined(USE_PREAD64)

  32993.   { "pread64",      (sqlite3_syscall_ptr)pread64,    0  },

  32994. #else

  32995.   { "pread64",      (sqlite3_syscall_ptr)0,          0  },

  32996. #endif

  32997. #define osPread64 ((ssize_t(*)(int,void*,size_t,off64_t))aSyscall[10].pCurrent)

  32998. 

  32999.   { "write",        (sqlite3_syscall_ptr)write,      0  },

  33000. #define osWrite     ((ssize_t(*)(int,const void*,size_t))aSyscall[11].pCurrent)

  33001. 

  33002. #if defined(USE_PREAD) || SQLITE_ENABLE_LOCKING_STYLE

  33003.   { "pwrite",       (sqlite3_syscall_ptr)pwrite,     0  },

  33004. #else

  33005.   { "pwrite",       (sqlite3_syscall_ptr)0,          0  },

  33006. #endif

  33007. #define osPwrite    ((ssize_t(*)(int,const void*,size_t,off_t))\

  33008.                     aSyscall[12].pCurrent)

  33009. 

  33010. #if defined(USE_PREAD64)

  33011.   { "pwrite64",     (sqlite3_syscall_ptr)pwrite64,   0  },

  33012. #else

  33013.   { "pwrite64",     (sqlite3_syscall_ptr)0,          0  },

  33014. #endif

  33015. #define osPwrite64  ((ssize_t(*)(int,const void*,size_t,off64_t))\

  33016.                     aSyscall[13].pCurrent)

  33017. 

  33018.   { "fchmod",       (sqlite3_syscall_ptr)fchmod,          0  },

  33019. #define osFchmod    ((int(*)(int,mode_t))aSyscall[14].pCurrent)

  33020. 

  33021. #if defined(HAVE_POSIX_FALLOCATE) && HAVE_POSIX_FALLOCATE

  33022.   { "fallocate",    (sqlite3_syscall_ptr)posix_fallocate,  0 },

  33023. #else

  33024.   { "fallocate",    (sqlite3_syscall_ptr)0,                0 },

  33025. #endif

  33026. #define osFallocate ((int(*)(int,off_t,off_t))aSyscall[15].pCurrent)

  33027. 

  33028.   { "unlink",       (sqlite3_syscall_ptr)unlink,           0 },

  33029. #define osUnlink    ((int(*)(const char*))aSyscall[16].pCurrent)

  33030. 

  33031.   { "openDirectory",    (sqlite3_syscall_ptr)openDirectory,      0 },

  33032. #define osOpenDirectory ((int(*)(const char*,int*))aSyscall[17].pCurrent)

  33033. 

  33034.   { "mkdir",        (sqlite3_syscall_ptr)mkdir,           0 },

  33035. #define osMkdir     ((int(*)(const char*,mode_t))aSyscall[18].pCurrent)

  33036. 

  33037.   { "rmdir",        (sqlite3_syscall_ptr)rmdir,           0 },

  33038. #define osRmdir     ((int(*)(const char*))aSyscall[19].pCurrent)

  33039. 

  33040. #if defined(HAVE_FCHOWN)

  33041.   { "fchown",       (sqlite3_syscall_ptr)fchown,          0 },

  33042. #else

  33043.   { "fchown",       (sqlite3_syscall_ptr)0,               0 },

  33044. #endif

  33045. #define osFchown    ((int(*)(int,uid_t,gid_t))aSyscall[20].pCurrent)

  33046. 

  33047. #if defined(HAVE_FCHOWN)

  33048.   { "geteuid",      (sqlite3_syscall_ptr)geteuid,         0 },

  33049. #else

  33050.   { "geteuid",      (sqlite3_syscall_ptr)0,               0 },

  33051. #endif

  33052. #define osGeteuid   ((uid_t(*)(void))aSyscall[21].pCurrent)

  33053. 

  33054. #if !defined(SQLITE_OMIT_WAL) || SQLITE_MAX_MMAP_SIZE>0

  33055.   { "mmap",         (sqlite3_syscall_ptr)mmap,            0 },

  33056. #else

  33057.   { "mmap",         (sqlite3_syscall_ptr)0,               0 },

  33058. #endif

  33059. #define osMmap ((void*(*)(void*,size_t,int,int,int,off_t))aSyscall[22].pCurrent)

  33060. 

  33061. #if !defined(SQLITE_OMIT_WAL) || SQLITE_MAX_MMAP_SIZE>0

  33062.   { "munmap",       (sqlite3_syscall_ptr)munmap,          0 },

  33063. #else

  33064.   { "munmap",       (sqlite3_syscall_ptr)0,               0 },

  33065. #endif

  33066. #define osMunmap ((int(*)(void*,size_t))aSyscall[23].pCurrent)

  33067. 

  33068. #if HAVE_MREMAP && (!defined(SQLITE_OMIT_WAL) || SQLITE_MAX_MMAP_SIZE>0)

  33069.   { "mremap",       (sqlite3_syscall_ptr)mremap,          0 },

  33070. #else

  33071.   { "mremap",       (sqlite3_syscall_ptr)0,               0 },

  33072. #endif

  33073. #define osMremap ((void*(*)(void*,size_t,size_t,int,...))aSyscall[24].pCurrent)

  33074. 

  33075. #if !defined(SQLITE_OMIT_WAL) || SQLITE_MAX_MMAP_SIZE>0

  33076.   { "getpagesize",  (sqlite3_syscall_ptr)unixGetpagesize, 0 },

  33077. #else

  33078.   { "getpagesize",  (sqlite3_syscall_ptr)0,               0 },

  33079. #endif

  33080. #define osGetpagesize ((int(*)(void))aSyscall[25].pCurrent)

  33081. 

  33082. #if defined(HAVE_READLINK)

  33083.   { "readlink",     (sqlite3_syscall_ptr)readlink,        0 },

  33084. #else

  33085.   { "readlink",     (sqlite3_syscall_ptr)0,               0 },

  33086. #endif

  33087. #define osReadlink ((ssize_t(*)(const char*,char*,size_t))aSyscall[26].pCurrent)

  33088. 

  33089. #if defined(HAVE_LSTAT)

  33090.   { "lstat",         (sqlite3_syscall_ptr)lstat,          0 },

  33091. #else

  33092.   { "lstat",         (sqlite3_syscall_ptr)0,              0 },

  33093. #endif

  33094. #define osLstat      ((int(*)(const char*,struct stat*))aSyscall[27].pCurrent)

  33095. 

  33096. #if defined(__linux__) && defined(SQLITE_ENABLE_BATCH_ATOMIC_WRITE)

  33097. # ifdef __ANDROID__

  33098.   { "ioctl", (sqlite3_syscall_ptr)(int(*)(int, int, ...))ioctl, 0 },

  33099. # else

  33100.   { "ioctl",         (sqlite3_syscall_ptr)ioctl,          0 },

  33101. # endif

  33102. #else

  33103.   { "ioctl",         (sqlite3_syscall_ptr)0,              0 },

  33104. #endif

  33105. #define osIoctl ((int(*)(int,int,...))aSyscall[28].pCurrent)

  33106. 

  33107. }; /* End of the overrideable system calls */

  33108. 

  33109. 

  33110. /*

  33111. ** On some systems, calls to fchown() will trigger a message in a security

  33112. ** log if they come from non-root processes.  So avoid calling fchown() if

  33113. ** we are not running as root.

  33114. */

  33115. static int robustFchown(int fd, uid_t uid, gid_t gid){

  33116. #if defined(HAVE_FCHOWN)

  33117.   return osGeteuid() ? 0 : osFchown(fd,uid,gid);

  33118. #else

  33119.   return 0;

  33120. #endif

  33121. }

  33122. 

  33123. /*

  33124. ** This is the xSetSystemCall() method of sqlite3_vfs for all of the

  33125. ** "unix" VFSes.  Return SQLITE_OK opon successfully updating the

  33126. ** system call pointer, or SQLITE_NOTFOUND if there is no configurable

  33127. ** system call named zName.

  33128. */

  33129. static int unixSetSystemCall(

  33130.   sqlite3_vfs *pNotUsed,        /* The VFS pointer.  Not used */

  33131.   const char *zName,            /* Name of system call to override */

  33132.   sqlite3_syscall_ptr pNewFunc  /* Pointer to new system call value */

  33133. ){

  33134.   unsigned int i;

  33135.   int rc = SQLITE_NOTFOUND;

  33136. 

  33137.   UNUSED_PARAMETER(pNotUsed);

  33138.   if( zName==0 ){

  33139.     /* If no zName is given, restore all system calls to their default

  33140.     ** settings and return NULL

  33141.     */

  33142.     rc = SQLITE_OK;

  33143.     for(i=0; i<sizeof(aSyscall)/sizeof(aSyscall[0]); i++){

  33144.       if( aSyscall[i].pDefault ){

  33145.         aSyscall[i].pCurrent = aSyscall[i].pDefault;

  33146.       }

  33147.     }

  33148.   }else{

  33149.     /* If zName is specified, operate on only the one system call

  33150.     ** specified.

  33151.     */

  33152.     for(i=0; i<sizeof(aSyscall)/sizeof(aSyscall[0]); i++){

  33153.       if( strcmp(zName, aSyscall[i].zName)==0 ){

  33154.         if( aSyscall[i].pDefault==0 ){

  33155.           aSyscall[i].pDefault = aSyscall[i].pCurrent;

  33156.         }

  33157.         rc = SQLITE_OK;

  33158.         if( pNewFunc==0 ) pNewFunc = aSyscall[i].pDefault;

  33159.         aSyscall[i].pCurrent = pNewFunc;

  33160.         break;

  33161.       }

  33162.     }

  33163.   }

  33164.   return rc;

  33165. }

  33166. 

  33167. /*

  33168. ** Return the value of a system call.  Return NULL if zName is not a

  33169. ** recognized system call name.  NULL is also returned if the system call

  33170. ** is currently undefined.

  33171. */

  33172. static sqlite3_syscall_ptr unixGetSystemCall(

  33173.   sqlite3_vfs *pNotUsed,

  33174.   const char *zName

  33175. ){

  33176.   unsigned int i;

  33177. 

  33178.   UNUSED_PARAMETER(pNotUsed);

  33179.   for(i=0; i<sizeof(aSyscall)/sizeof(aSyscall[0]); i++){

  33180.     if( strcmp(zName, aSyscall[i].zName)==0 ) return aSyscall[i].pCurrent;

  33181.   }

  33182.   return 0;

  33183. }

  33184. 

  33185. /*

  33186. ** Return the name of the first system call after zName.  If zName==NULL

  33187. ** then return the name of the first system call.  Return NULL if zName

  33188. ** is the last system call or if zName is not the name of a valid

  33189. ** system call.

  33190. */

  33191. static const char *unixNextSystemCall(sqlite3_vfs *p, const char *zName){

  33192.   int i = -1;

  33193. 

  33194.   UNUSED_PARAMETER(p);

  33195.   if( zName ){

  33196.     for(i=0; i<ArraySize(aSyscall)-1; i++){

  33197.       if( strcmp(zName, aSyscall[i].zName)==0 ) break;

  33198.     }

  33199.   }

  33200.   for(i++; i<ArraySize(aSyscall); i++){

  33201.     if( aSyscall[i].pCurrent!=0 ) return aSyscall[i].zName;

  33202.   }

  33203.   return 0;

  33204. }

  33205. 

  33206. /*

  33207. ** Do not accept any file descriptor less than this value, in order to avoid

  33208. ** opening database file using file descriptors that are commonly used for 

  33209. ** standard input, output, and error.

  33210. */

  33211. #ifndef SQLITE_MINIMUM_FILE_DESCRIPTOR

  33212. # define SQLITE_MINIMUM_FILE_DESCRIPTOR 3

  33213. #endif

  33214. 

  33215. /*

  33216. ** Invoke open().  Do so multiple times, until it either succeeds or

  33217. ** fails for some reason other than EINTR.

  33218. **

  33219. ** If the file creation mode "m" is 0 then set it to the default for

  33220. ** SQLite.  The default is SQLITE_DEFAULT_FILE_PERMISSIONS (normally

  33221. ** 0644) as modified by the system umask.  If m is not 0, then

  33222. ** make the file creation mode be exactly m ignoring the umask.

  33223. **

  33224. ** The m parameter will be non-zero only when creating -wal, -journal,

  33225. ** and -shm files.  We want those files to have *exactly* the same

  33226. ** permissions as their original database, unadulterated by the umask.

  33227. ** In that way, if a database file is -rw-rw-rw or -rw-rw-r-, and a

  33228. ** transaction crashes and leaves behind hot journals, then any

  33229. ** process that is able to write to the database will also be able to

  33230. ** recover the hot journals.

  33231. */

  33232. static int robust_open(const char *z, int f, mode_t m){

  33233.   int fd;

  33234.   mode_t m2 = m ? m : SQLITE_DEFAULT_FILE_PERMISSIONS;

  33235.   while(1){

  33236. #if defined(O_CLOEXEC)

  33237.     fd = osOpen(z,f|O_CLOEXEC,m2);

  33238. #else

  33239.     fd = osOpen(z,f,m2);

  33240. #endif

  33241.     if( fd<0 ){

  33242.       if( errno==EINTR ) continue;

  33243.       break;

  33244.     }

  33245.     if( fd>=SQLITE_MINIMUM_FILE_DESCRIPTOR ) break;

  33246.     osClose(fd);

  33247.     sqlite3_log(SQLITE_WARNING, 

  33248.                 "attempt to open \"%s\" as file descriptor %d", z, fd);

  33249.     fd = -1;

  33250.     if( osOpen("/dev/null", f, m)<0 ) break;

  33251.   }

  33252.   if( fd>=0 ){

  33253.     if( m!=0 ){

  33254.       struct stat statbuf;

  33255.       if( osFstat(fd, &statbuf)==0 

  33256.        && statbuf.st_size==0

  33257.        && (statbuf.st_mode&0777)!=m 

  33258.       ){

  33259.         osFchmod(fd, m);

  33260.       }

  33261.     }

  33262. #if defined(FD_CLOEXEC) && (!defined(O_CLOEXEC) || O_CLOEXEC==0)

  33263.     osFcntl(fd, F_SETFD, osFcntl(fd, F_GETFD, 0) | FD_CLOEXEC);

  33264. #endif

  33265.   }

  33266.   return fd;

  33267. }

  33268. 

  33269. /*

  33270. ** Helper functions to obtain and relinquish the global mutex. The

  33271. ** global mutex is used to protect the unixInodeInfo and

  33272. ** vxworksFileId objects used by this file, all of which may be 

  33273. ** shared by multiple threads.

  33274. **

  33275. ** Function unixMutexHeld() is used to assert() that the global mutex 

  33276. ** is held when required. This function is only used as part of assert() 

  33277. ** statements. e.g.

  33278. **

  33279. **   unixEnterMutex()

  33280. **     assert( unixMutexHeld() );

  33281. **   unixEnterLeave()

  33282. **

  33283. ** To prevent deadlock, the global unixBigLock must must be acquired

  33284. ** before the unixInodeInfo.pLockMutex mutex, if both are held.  It is

  33285. ** OK to get the pLockMutex without holding unixBigLock first, but if

  33286. ** that happens, the unixBigLock mutex must not be acquired until after

  33287. ** pLockMutex is released.

  33288. **

  33289. **      OK:     enter(unixBigLock),  enter(pLockInfo)

  33290. **      OK:     enter(unixBigLock)

  33291. **      OK:     enter(pLockInfo)

  33292. **   ERROR:     enter(pLockInfo), enter(unixBigLock)

  33293. */

  33294. static sqlite3_mutex *unixBigLock = 0;

  33295. static void unixEnterMutex(void){

  33296.   assert( sqlite3_mutex_notheld(unixBigLock) );  /* Not a recursive mutex */

  33297.   sqlite3_mutex_enter(unixBigLock);

  33298. }

  33299. static void unixLeaveMutex(void){

  33300.   assert( sqlite3_mutex_held(unixBigLock) );

  33301.   sqlite3_mutex_leave(unixBigLock);

  33302. }

  33303. #ifdef SQLITE_DEBUG

  33304. static int unixMutexHeld(void) {

  33305.   return sqlite3_mutex_held(unixBigLock);

  33306. }

  33307. #endif

  33308. 

  33309. 

  33310. #ifdef SQLITE_HAVE_OS_TRACE

  33311. /*

  33312. ** Helper function for printing out trace information from debugging

  33313. ** binaries. This returns the string representation of the supplied

  33314. ** integer lock-type.

  33315. */

  33316. static const char *azFileLock(int eFileLock){

  33317.   switch( eFileLock ){

  33318.     case NO_LOCK: return "NONE";

  33319.     case SHARED_LOCK: return "SHARED";

  33320.     case RESERVED_LOCK: return "RESERVED";

  33321.     case PENDING_LOCK: return "PENDING";

  33322.     case EXCLUSIVE_LOCK: return "EXCLUSIVE";

  33323.   }

  33324.   return "ERROR";

  33325. }

  33326. #endif

  33327. 

  33328. #ifdef SQLITE_LOCK_TRACE

  33329. /*

  33330. ** Print out information about all locking operations.

  33331. **

  33332. ** This routine is used for troubleshooting locks on multithreaded

  33333. ** platforms.  Enable by compiling with the -DSQLITE_LOCK_TRACE

  33334. ** command-line option on the compiler.  This code is normally

  33335. ** turned off.

  33336. */

  33337. static int lockTrace(int fd, int op, struct flock *p){

  33338.   char *zOpName, *zType;

  33339.   int s;

  33340.   int savedErrno;

  33341.   if( op==F_GETLK ){

  33342.     zOpName = "GETLK";

  33343.   }else if( op==F_SETLK ){

  33344.     zOpName = "SETLK";

  33345.   }else{

  33346.     s = osFcntl(fd, op, p);

  33347.     sqlite3DebugPrintf("fcntl unknown %d %d %d\n", fd, op, s);

  33348.     return s;

  33349.   }

  33350.   if( p->l_type==F_RDLCK ){

  33351.     zType = "RDLCK";

  33352.   }else if( p->l_type==F_WRLCK ){

  33353.     zType = "WRLCK";

  33354.   }else if( p->l_type==F_UNLCK ){

  33355.     zType = "UNLCK";

  33356.   }else{

  33357.     assert( 0 );

  33358.   }

  33359.   assert( p->l_whence==SEEK_SET );

  33360.   s = osFcntl(fd, op, p);

  33361.   savedErrno = errno;

  33362.   sqlite3DebugPrintf("fcntl %d %d %s %s %d %d %d %d\n",

  33363.      threadid, fd, zOpName, zType, (int)p->l_start, (int)p->l_len,

  33364.      (int)p->l_pid, s);

  33365.   if( s==(-1) && op==F_SETLK && (p->l_type==F_RDLCK || p->l_type==F_WRLCK) ){

  33366.     struct flock l2;

  33367.     l2 = *p;

  33368.     osFcntl(fd, F_GETLK, &l2);

  33369.     if( l2.l_type==F_RDLCK ){

  33370.       zType = "RDLCK";

  33371.     }else if( l2.l_type==F_WRLCK ){

  33372.       zType = "WRLCK";

  33373.     }else if( l2.l_type==F_UNLCK ){

  33374.       zType = "UNLCK";

  33375.     }else{

  33376.       assert( 0 );

  33377.     }

  33378.     sqlite3DebugPrintf("fcntl-failure-reason: %s %d %d %d\n",

  33379.        zType, (int)l2.l_start, (int)l2.l_len, (int)l2.l_pid);

  33380.   }

  33381.   errno = savedErrno;

  33382.   return s;

  33383. }

  33384. #undef osFcntl

  33385. #define osFcntl lockTrace

  33386. #endif /* SQLITE_LOCK_TRACE */

  33387. 

  33388. /*

  33389. ** Retry ftruncate() calls that fail due to EINTR

  33390. **

  33391. ** All calls to ftruncate() within this file should be made through

  33392. ** this wrapper.  On the Android platform, bypassing the logic below

  33393. ** could lead to a corrupt database.

  33394. */

  33395. static int robust_ftruncate(int h, sqlite3_int64 sz){

  33396.   int rc;

  33397. #ifdef __ANDROID__

  33398.   /* On Android, ftruncate() always uses 32-bit offsets, even if 

  33399.   ** _FILE_OFFSET_BITS=64 is defined. This means it is unsafe to attempt to

  33400.   ** truncate a file to any size larger than 2GiB. Silently ignore any

  33401.   ** such attempts.  */

  33402.   if( sz>(sqlite3_int64)0x7FFFFFFF ){

  33403.     rc = SQLITE_OK;

  33404.   }else

  33405. #endif

  33406.   do{ rc = osFtruncate(h,sz); }while( rc<0 && errno==EINTR );

  33407.   return rc;

  33408. }

  33409. 

  33410. /*

  33411. ** This routine translates a standard POSIX errno code into something

  33412. ** useful to the clients of the sqlite3 functions.  Specifically, it is

  33413. ** intended to translate a variety of "try again" errors into SQLITE_BUSY

  33414. ** and a variety of "please close the file descriptor NOW" errors into 

  33415. ** SQLITE_IOERR

  33416. ** 

  33417. ** Errors during initialization of locks, or file system support for locks,

  33418. ** should handle ENOLCK, ENOTSUP, EOPNOTSUPP separately.

  33419. */

  33420. static int sqliteErrorFromPosixError(int posixError, int sqliteIOErr) {

  33421.   assert( (sqliteIOErr == SQLITE_IOERR_LOCK) || 

  33422.           (sqliteIOErr == SQLITE_IOERR_UNLOCK) || 

  33423.           (sqliteIOErr == SQLITE_IOERR_RDLOCK) ||

  33424.           (sqliteIOErr == SQLITE_IOERR_CHECKRESERVEDLOCK) );

  33425.   switch (posixError) {

  33426.   case EACCES: 

  33427.   case EAGAIN:

  33428.   case ETIMEDOUT:

  33429.   case EBUSY:

  33430.   case EINTR:

  33431.   case ENOLCK:  

  33432.     /* random NFS retry error, unless during file system support 

  33433.      * introspection, in which it actually means what it says */

  33434.     return SQLITE_BUSY;

  33435.     

  33436.   case EPERM: 

  33437.     return SQLITE_PERM;

  33438.     

  33439.   default: 

  33440.     return sqliteIOErr;

  33441.   }

  33442. }

  33443. 

  33444. 

  33445. /******************************************************************************

  33446. ****************** Begin Unique File ID Utility Used By VxWorks ***************

  33447. **

  33448. ** On most versions of unix, we can get a unique ID for a file by concatenating

  33449. ** the device number and the inode number.  But this does not work on VxWorks.

  33450. ** On VxWorks, a unique file id must be based on the canonical filename.

  33451. **

  33452. ** A pointer to an instance of the following structure can be used as a

  33453. ** unique file ID in VxWorks.  Each instance of this structure contains

  33454. ** a copy of the canonical filename.  There is also a reference count.  

  33455. ** The structure is reclaimed when the number of pointers to it drops to

  33456. ** zero.

  33457. **

  33458. ** There are never very many files open at one time and lookups are not

  33459. ** a performance-critical path, so it is sufficient to put these

  33460. ** structures on a linked list.

  33461. */

  33462. struct vxworksFileId {

  33463.   struct vxworksFileId *pNext;  /* Next in a list of them all */

  33464.   int nRef;                     /* Number of references to this one */

  33465.   int nName;                    /* Length of the zCanonicalName[] string */

  33466.   char *zCanonicalName;         /* Canonical filename */

  33467. };

  33468. 

  33469. #if OS_VXWORKS

  33470. /* 

  33471. ** All unique filenames are held on a linked list headed by this

  33472. ** variable:

  33473. */

  33474. static struct vxworksFileId *vxworksFileList = 0;

  33475. 

  33476. /*

  33477. ** Simplify a filename into its canonical form

  33478. ** by making the following changes:

  33479. **

  33480. **  * removing any trailing and duplicate /

  33481. **  * convert /./ into just /

  33482. **  * convert /A/../ where A is any simple name into just /

  33483. **

  33484. ** Changes are made in-place.  Return the new name length.

  33485. **

  33486. ** The original filename is in z[0..n-1].  Return the number of

  33487. ** characters in the simplified name.

  33488. */

  33489. static int vxworksSimplifyName(char *z, int n){

  33490.   int i, j;

  33491.   while( n>1 && z[n-1]=='/' ){ n--; }

  33492.   for(i=j=0; i<n; i++){

  33493.     if( z[i]=='/' ){

  33494.       if( z[i+1]=='/' ) continue;

  33495.       if( z[i+1]=='.' && i+2<n && z[i+2]=='/' ){

  33496.         i += 1;

  33497.         continue;

  33498.       }

  33499.       if( z[i+1]=='.' && i+3<n && z[i+2]=='.' && z[i+3]=='/' ){

  33500.         while( j>0 && z[j-1]!='/' ){ j--; }

  33501.         if( j>0 ){ j--; }

  33502.         i += 2;

  33503.         continue;

  33504.       }

  33505.     }

  33506.     z[j++] = z[i];

  33507.   }

  33508.   z[j] = 0;

  33509.   return j;

  33510. }

  33511. 

  33512. /*

  33513. ** Find a unique file ID for the given absolute pathname.  Return

  33514. ** a pointer to the vxworksFileId object.  This pointer is the unique

  33515. ** file ID.

  33516. **

  33517. ** The nRef field of the vxworksFileId object is incremented before

  33518. ** the object is returned.  A new vxworksFileId object is created

  33519. ** and added to the global list if necessary.

  33520. **

  33521. ** If a memory allocation error occurs, return NULL.

  33522. */

  33523. static struct vxworksFileId *vxworksFindFileId(const char *zAbsoluteName){

  33524.   struct vxworksFileId *pNew;         /* search key and new file ID */

  33525.   struct vxworksFileId *pCandidate;   /* For looping over existing file IDs */

  33526.   int n;                              /* Length of zAbsoluteName string */

  33527. 

  33528.   assert( zAbsoluteName[0]=='/' );

  33529.   n = (int)strlen(zAbsoluteName);

  33530.   pNew = sqlite3_malloc64( sizeof(*pNew) + (n+1) );

  33531.   if( pNew==0 ) return 0;

  33532.   pNew->zCanonicalName = (char*)&pNew[1];

  33533.   memcpy(pNew->zCanonicalName, zAbsoluteName, n+1);

  33534.   n = vxworksSimplifyName(pNew->zCanonicalName, n);

  33535. 

  33536.   /* Search for an existing entry that matching the canonical name.

  33537.   ** If found, increment the reference count and return a pointer to

  33538.   ** the existing file ID.

  33539.   */

  33540.   unixEnterMutex();

  33541.   for(pCandidate=vxworksFileList; pCandidate; pCandidate=pCandidate->pNext){

  33542.     if( pCandidate->nName==n 

  33543.      && memcmp(pCandidate->zCanonicalName, pNew->zCanonicalName, n)==0

  33544.     ){

  33545.        sqlite3_free(pNew);

  33546.        pCandidate->nRef++;

  33547.        unixLeaveMutex();

  33548.        return pCandidate;

  33549.     }

  33550.   }

  33551. 

  33552.   /* No match was found.  We will make a new file ID */

  33553.   pNew->nRef = 1;

  33554.   pNew->nName = n;

  33555.   pNew->pNext = vxworksFileList;

  33556.   vxworksFileList = pNew;

  33557.   unixLeaveMutex();

  33558.   return pNew;

  33559. }

  33560. 

  33561. /*

  33562. ** Decrement the reference count on a vxworksFileId object.  Free

  33563. ** the object when the reference count reaches zero.

  33564. */

  33565. static void vxworksReleaseFileId(struct vxworksFileId *pId){

  33566.   unixEnterMutex();

  33567.   assert( pId->nRef>0 );

  33568.   pId->nRef--;

  33569.   if( pId->nRef==0 ){

  33570.     struct vxworksFileId **pp;

  33571.     for(pp=&vxworksFileList; *pp && *pp!=pId; pp = &((*pp)->pNext)){}

  33572.     assert( *pp==pId );

  33573.     *pp = pId->pNext;

  33574.     sqlite3_free(pId);

  33575.   }

  33576.   unixLeaveMutex();

  33577. }

  33578. #endif /* OS_VXWORKS */

  33579. /*************** End of Unique File ID Utility Used By VxWorks ****************

  33580. ******************************************************************************/

  33581. 

  33582. 

  33583. /******************************************************************************

  33584. *************************** Posix Advisory Locking ****************************

  33585. **

  33586. ** POSIX advisory locks are broken by design.  ANSI STD 1003.1 (1996)

  33587. ** section 6.5.2.2 lines 483 through 490 specify that when a process

  33588. ** sets or clears a lock, that operation overrides any prior locks set

  33589. ** by the same process.  It does not explicitly say so, but this implies

  33590. ** that it overrides locks set by the same process using a different

  33591. ** file descriptor.  Consider this test case:

  33592. **

  33593. **       int fd1 = open("./file1", O_RDWR|O_CREAT, 0644);

  33594. **       int fd2 = open("./file2", O_RDWR|O_CREAT, 0644);

  33595. **

  33596. ** Suppose ./file1 and ./file2 are really the same file (because

  33597. ** one is a hard or symbolic link to the other) then if you set

  33598. ** an exclusive lock on fd1, then try to get an exclusive lock

  33599. ** on fd2, it works.  I would have expected the second lock to

  33600. ** fail since there was already a lock on the file due to fd1.

  33601. ** But not so.  Since both locks came from the same process, the

  33602. ** second overrides the first, even though they were on different

  33603. ** file descriptors opened on different file names.

  33604. **

  33605. ** This means that we cannot use POSIX locks to synchronize file access

  33606. ** among competing threads of the same process.  POSIX locks will work fine

  33607. ** to synchronize access for threads in separate processes, but not

  33608. ** threads within the same process.

  33609. **

  33610. ** To work around the problem, SQLite has to manage file locks internally

  33611. ** on its own.  Whenever a new database is opened, we have to find the

  33612. ** specific inode of the database file (the inode is determined by the

  33613. ** st_dev and st_ino fields of the stat structure that fstat() fills in)

  33614. ** and check for locks already existing on that inode.  When locks are

  33615. ** created or removed, we have to look at our own internal record of the

  33616. ** locks to see if another thread has previously set a lock on that same

  33617. ** inode.

  33618. **

  33619. ** (Aside: The use of inode numbers as unique IDs does not work on VxWorks.

  33620. ** For VxWorks, we have to use the alternative unique ID system based on

  33621. ** canonical filename and implemented in the previous division.)

  33622. **

  33623. ** The sqlite3_file structure for POSIX is no longer just an integer file

  33624. ** descriptor.  It is now a structure that holds the integer file

  33625. ** descriptor and a pointer to a structure that describes the internal

  33626. ** locks on the corresponding inode.  There is one locking structure

  33627. ** per inode, so if the same inode is opened twice, both unixFile structures

  33628. ** point to the same locking structure.  The locking structure keeps

  33629. ** a reference count (so we will know when to delete it) and a "cnt"

  33630. ** field that tells us its internal lock status.  cnt==0 means the

  33631. ** file is unlocked.  cnt==-1 means the file has an exclusive lock.

  33632. ** cnt>0 means there are cnt shared locks on the file.

  33633. **

  33634. ** Any attempt to lock or unlock a file first checks the locking

  33635. ** structure.  The fcntl() system call is only invoked to set a 

  33636. ** POSIX lock if the internal lock structure transitions between

  33637. ** a locked and an unlocked state.

  33638. **

  33639. ** But wait:  there are yet more problems with POSIX advisory locks.

  33640. **

  33641. ** If you close a file descriptor that points to a file that has locks,

  33642. ** all locks on that file that are owned by the current process are

  33643. ** released.  To work around this problem, each unixInodeInfo object

  33644. ** maintains a count of the number of pending locks on tha inode.

  33645. ** When an attempt is made to close an unixFile, if there are

  33646. ** other unixFile open on the same inode that are holding locks, the call

  33647. ** to close() the file descriptor is deferred until all of the locks clear.

  33648. ** The unixInodeInfo structure keeps a list of file descriptors that need to

  33649. ** be closed and that list is walked (and cleared) when the last lock

  33650. ** clears.

  33651. **

  33652. ** Yet another problem:  LinuxThreads do not play well with posix locks.

  33653. **

  33654. ** Many older versions of linux use the LinuxThreads library which is

  33655. ** not posix compliant.  Under LinuxThreads, a lock created by thread

  33656. ** A cannot be modified or overridden by a different thread B.

  33657. ** Only thread A can modify the lock.  Locking behavior is correct

  33658. ** if the appliation uses the newer Native Posix Thread Library (NPTL)

  33659. ** on linux - with NPTL a lock created by thread A can override locks

  33660. ** in thread B.  But there is no way to know at compile-time which

  33661. ** threading library is being used.  So there is no way to know at

  33662. ** compile-time whether or not thread A can override locks on thread B.

  33663. ** One has to do a run-time check to discover the behavior of the

  33664. ** current process.

  33665. **

  33666. ** SQLite used to support LinuxThreads.  But support for LinuxThreads

  33667. ** was dropped beginning with version 3.7.0.  SQLite will still work with

  33668. ** LinuxThreads provided that (1) there is no more than one connection 

  33669. ** per database file in the same process and (2) database connections

  33670. ** do not move across threads.

  33671. */

  33672. 

  33673. /*

  33674. ** An instance of the following structure serves as the key used

  33675. ** to locate a particular unixInodeInfo object.

  33676. */

  33677. struct unixFileId {

  33678.   dev_t dev;                  /* Device number */

  33679. #if OS_VXWORKS

  33680.   struct vxworksFileId *pId;  /* Unique file ID for vxworks. */

  33681. #else

  33682.   /* We are told that some versions of Android contain a bug that

  33683.   ** sizes ino_t at only 32-bits instead of 64-bits. (See

  33684.   ** https://android-review.googlesource.com/#/c/115351/3/dist/sqlite3.c)

  33685.   ** To work around this, always allocate 64-bits for the inode number.  

  33686.   ** On small machines that only have 32-bit inodes, this wastes 4 bytes,

  33687.   ** but that should not be a big deal. */

  33688.   /* WAS:  ino_t ino;   */

  33689.   u64 ino;                   /* Inode number */

  33690. #endif

  33691. };

  33692. 

  33693. /*

  33694. ** An instance of the following structure is allocated for each open

  33695. ** inode.

  33696. **

  33697. ** A single inode can have multiple file descriptors, so each unixFile

  33698. ** structure contains a pointer to an instance of this object and this

  33699. ** object keeps a count of the number of unixFile pointing to it.

  33700. **

  33701. ** Mutex rules:

  33702. **

  33703. **  (1) Only the pLockMutex mutex must be held in order to read or write

  33704. **      any of the locking fields:

  33705. **          nShared, nLock, eFileLock, bProcessLock, pUnused

  33706. **

  33707. **  (2) When nRef>0, then the following fields are unchanging and can

  33708. **      be read (but not written) without holding any mutex:

  33709. **          fileId, pLockMutex

  33710. **

  33711. **  (3) With the exceptions above, all the fields may only be read

  33712. **      or written while holding the global unixBigLock mutex.

  33713. **

  33714. ** Deadlock prevention:  The global unixBigLock mutex may not

  33715. ** be acquired while holding the pLockMutex mutex.  If both unixBigLock

  33716. ** and pLockMutex are needed, then unixBigLock must be acquired first.

  33717. */

  33718. struct unixInodeInfo {

  33719.   struct unixFileId fileId;       /* The lookup key */

  33720.   sqlite3_mutex *pLockMutex;      /* Hold this mutex for... */

  33721.   int nShared;                      /* Number of SHARED locks held */

  33722.   int nLock;                        /* Number of outstanding file locks */

  33723.   unsigned char eFileLock;          /* One of SHARED_LOCK, RESERVED_LOCK etc. */

  33724.   unsigned char bProcessLock;       /* An exclusive process lock is held */

  33725.   UnixUnusedFd *pUnused;            /* Unused file descriptors to close */

  33726.   int nRef;                       /* Number of pointers to this structure */

  33727.   unixShmNode *pShmNode;          /* Shared memory associated with this inode */

  33728.   unixInodeInfo *pNext;           /* List of all unixInodeInfo objects */

  33729.   unixInodeInfo *pPrev;           /*    .... doubly linked */

  33730. #if SQLITE_ENABLE_LOCKING_STYLE

  33731.   unsigned long long sharedByte;  /* for AFP simulated shared lock */

  33732. #endif

  33733. #if OS_VXWORKS

  33734.   sem_t *pSem;                    /* Named POSIX semaphore */

  33735.   char aSemName[MAX_PATHNAME+2];  /* Name of that semaphore */

  33736. #endif

  33737. };

  33738. 

  33739. /*

  33740. ** A lists of all unixInodeInfo objects.

  33741. **

  33742. ** Must hold unixBigLock in order to read or write this variable.

  33743. */

  33744. static unixInodeInfo *inodeList = 0;  /* All unixInodeInfo objects */

  33745. 

  33746. #ifdef SQLITE_DEBUG

  33747. /*

  33748. ** True if the inode mutex (on the unixFile.pFileMutex field) is held, or not.

  33749. ** This routine is used only within assert() to help verify correct mutex

  33750. ** usage.

  33751. */

  33752. int unixFileMutexHeld(unixFile *pFile){

  33753.   assert( pFile->pInode );

  33754.   return sqlite3_mutex_held(pFile->pInode->pLockMutex);

  33755. }

  33756. int unixFileMutexNotheld(unixFile *pFile){

  33757.   assert( pFile->pInode );

  33758.   return sqlite3_mutex_notheld(pFile->pInode->pLockMutex);

  33759. }

  33760. #endif

  33761. 

  33762. /*

  33763. **

  33764. ** This function - unixLogErrorAtLine(), is only ever called via the macro

  33765. ** unixLogError().

  33766. **

  33767. ** It is invoked after an error occurs in an OS function and errno has been

  33768. ** set. It logs a message using sqlite3_log() containing the current value of

  33769. ** errno and, if possible, the human-readable equivalent from strerror() or

  33770. ** strerror_r().

  33771. **

  33772. ** The first argument passed to the macro should be the error code that

  33773. ** will be returned to SQLite (e.g. SQLITE_IOERR_DELETE, SQLITE_CANTOPEN). 

  33774. ** The two subsequent arguments should be the name of the OS function that

  33775. ** failed (e.g. "unlink", "open") and the associated file-system path,

  33776. ** if any.

  33777. */

  33778. #define unixLogError(a,b,c)     unixLogErrorAtLine(a,b,c,__LINE__)

  33779. static int unixLogErrorAtLine(

  33780.   int errcode,                    /* SQLite error code */

  33781.   const char *zFunc,              /* Name of OS function that failed */

  33782.   const char *zPath,              /* File path associated with error */

  33783.   int iLine                       /* Source line number where error occurred */

  33784. ){

  33785.   char *zErr;                     /* Message from strerror() or equivalent */

  33786.   int iErrno = errno;             /* Saved syscall error number */

  33787. 

  33788.   /* If this is not a threadsafe build (SQLITE_THREADSAFE==0), then use

  33789.   ** the strerror() function to obtain the human-readable error message

  33790.   ** equivalent to errno. Otherwise, use strerror_r().

  33791.   */ 

  33792. #if SQLITE_THREADSAFE && defined(HAVE_STRERROR_R)

  33793.   char aErr[80];

  33794.   memset(aErr, 0, sizeof(aErr));

  33795.   zErr = aErr;

  33796. 

  33797.   /* If STRERROR_R_CHAR_P (set by autoconf scripts) or __USE_GNU is defined,

  33798.   ** assume that the system provides the GNU version of strerror_r() that

  33799.   ** returns a pointer to a buffer containing the error message. That pointer 

  33800.   ** may point to aErr[], or it may point to some static storage somewhere. 

  33801.   ** Otherwise, assume that the system provides the POSIX version of 

  33802.   ** strerror_r(), which always writes an error message into aErr[].

  33803.   **

  33804.   ** If the code incorrectly assumes that it is the POSIX version that is

  33805.   ** available, the error message will often be an empty string. Not a

  33806.   ** huge problem. Incorrectly concluding that the GNU version is available 

  33807.   ** could lead to a segfault though.

  33808.   */

  33809. #if defined(STRERROR_R_CHAR_P) || defined(__USE_GNU)

  33810.   zErr = 

  33811. # endif

  33812.   strerror_r(iErrno, aErr, sizeof(aErr)-1);

  33813. 

  33814. #elif SQLITE_THREADSAFE

  33815.   /* This is a threadsafe build, but strerror_r() is not available. */

  33816.   zErr = "";

  33817. #else

  33818.   /* Non-threadsafe build, use strerror(). */

  33819.   zErr = strerror(iErrno);

  33820. #endif

  33821. 

  33822.   if( zPath==0 ) zPath = "";

  33823.   sqlite3_log(errcode,

  33824.       "os_unix.c:%d: (%d) %s(%s) - %s",

  33825.       iLine, iErrno, zFunc, zPath, zErr

  33826.   );

  33827. 

  33828.   return errcode;

  33829. }

  33830. 

  33831. /*

  33832. ** Close a file descriptor.

  33833. **

  33834. ** We assume that close() almost always works, since it is only in a

  33835. ** very sick application or on a very sick platform that it might fail.

  33836. ** If it does fail, simply leak the file descriptor, but do log the

  33837. ** error.

  33838. **

  33839. ** Note that it is not safe to retry close() after EINTR since the

  33840. ** file descriptor might have already been reused by another thread.

  33841. ** So we don't even try to recover from an EINTR.  Just log the error

  33842. ** and move on.

  33843. */

  33844. static void robust_close(unixFile *pFile, int h, int lineno){

  33845.   if( osClose(h) ){

  33846.     unixLogErrorAtLine(SQLITE_IOERR_CLOSE, "close",

  33847.                        pFile ? pFile->zPath : 0, lineno);

  33848.   }

  33849. }

  33850. 

  33851. /*

  33852. ** Set the pFile->lastErrno.  Do this in a subroutine as that provides

  33853. ** a convenient place to set a breakpoint.

  33854. */

  33855. static void storeLastErrno(unixFile *pFile, int error){

  33856.   pFile->lastErrno = error;

  33857. }

  33858. 

  33859. /*

  33860. ** Close all file descriptors accumuated in the unixInodeInfo->pUnused list.

  33861. */ 

  33862. static void closePendingFds(unixFile *pFile){

  33863.   unixInodeInfo *pInode = pFile->pInode;

  33864.   UnixUnusedFd *p;

  33865.   UnixUnusedFd *pNext;

  33866.   assert( unixFileMutexHeld(pFile) );

  33867.   for(p=pInode->pUnused; p; p=pNext){

  33868.     pNext = p->pNext;

  33869.     robust_close(pFile, p->fd, __LINE__);

  33870.     sqlite3_free(p);

  33871.   }

  33872.   pInode->pUnused = 0;

  33873. }

  33874. 

  33875. /*

  33876. ** Release a unixInodeInfo structure previously allocated by findInodeInfo().

  33877. **

  33878. ** The global mutex must be held when this routine is called, but the mutex

  33879. ** on the inode being deleted must NOT be held.

  33880. */

  33881. static void releaseInodeInfo(unixFile *pFile){

  33882.   unixInodeInfo *pInode = pFile->pInode;

  33883.   assert( unixMutexHeld() );

  33884.   assert( unixFileMutexNotheld(pFile) );

  33885.   if( ALWAYS(pInode) ){

  33886.     pInode->nRef--;

  33887.     if( pInode->nRef==0 ){

  33888.       assert( pInode->pShmNode==0 );

  33889.       sqlite3_mutex_enter(pInode->pLockMutex);

  33890.       closePendingFds(pFile);

  33891.       sqlite3_mutex_leave(pInode->pLockMutex);

  33892.       if( pInode->pPrev ){

  33893.         assert( pInode->pPrev->pNext==pInode );

  33894.         pInode->pPrev->pNext = pInode->pNext;

  33895.       }else{

  33896.         assert( inodeList==pInode );

  33897.         inodeList = pInode->pNext;

  33898.       }

  33899.       if( pInode->pNext ){

  33900.         assert( pInode->pNext->pPrev==pInode );

  33901.         pInode->pNext->pPrev = pInode->pPrev;

  33902.       }

  33903.       sqlite3_mutex_free(pInode->pLockMutex);

  33904.       sqlite3_free(pInode);

  33905.     }

  33906.   }

  33907. }

  33908. 

  33909. /*

  33910. ** Given a file descriptor, locate the unixInodeInfo object that

  33911. ** describes that file descriptor.  Create a new one if necessary.  The

  33912. ** return value might be uninitialized if an error occurs.

  33913. **

  33914. ** The global mutex must held when calling this routine.

  33915. **

  33916. ** Return an appropriate error code.

  33917. */

  33918. static int findInodeInfo(

  33919.   unixFile *pFile,               /* Unix file with file desc used in the key */

  33920.   unixInodeInfo **ppInode        /* Return the unixInodeInfo object here */

  33921. ){

  33922.   int rc;                        /* System call return code */

  33923.   int fd;                        /* The file descriptor for pFile */

  33924.   struct unixFileId fileId;      /* Lookup key for the unixInodeInfo */

  33925.   struct stat statbuf;           /* Low-level file information */

  33926.   unixInodeInfo *pInode = 0;     /* Candidate unixInodeInfo object */

  33927. 

  33928.   assert( unixMutexHeld() );

  33929. 

  33930.   /* Get low-level information about the file that we can used to

  33931.   ** create a unique name for the file.

  33932.   */

  33933.   fd = pFile->h;

  33934.   rc = osFstat(fd, &statbuf);

  33935.   if( rc!=0 ){

  33936.     storeLastErrno(pFile, errno);

  33937. #if defined(EOVERFLOW) && defined(SQLITE_DISABLE_LFS)

  33938.     if( pFile->lastErrno==EOVERFLOW ) return SQLITE_NOLFS;

  33939. #endif

  33940.     return SQLITE_IOERR;

  33941.   }

  33942. 

  33943. #ifdef __APPLE__

  33944.   /* On OS X on an msdos filesystem, the inode number is reported

  33945.   ** incorrectly for zero-size files.  See ticket #3260.  To work

  33946.   ** around this problem (we consider it a bug in OS X, not SQLite)

  33947.   ** we always increase the file size to 1 by writing a single byte

  33948.   ** prior to accessing the inode number.  The one byte written is

  33949.   ** an ASCII 'S' character which also happens to be the first byte

  33950.   ** in the header of every SQLite database.  In this way, if there

  33951.   ** is a race condition such that another thread has already populated

  33952.   ** the first page of the database, no damage is done.

  33953.   */

  33954.   if( statbuf.st_size==0 && (pFile->fsFlags & SQLITE_FSFLAGS_IS_MSDOS)!=0 ){

  33955.     do{ rc = osWrite(fd, "S", 1); }while( rc<0 && errno==EINTR );

  33956.     if( rc!=1 ){

  33957.       storeLastErrno(pFile, errno);

  33958.       return SQLITE_IOERR;

  33959.     }

  33960.     rc = osFstat(fd, &statbuf);

  33961.     if( rc!=0 ){

  33962.       storeLastErrno(pFile, errno);

  33963.       return SQLITE_IOERR;

  33964.     }

  33965.   }

  33966. #endif

  33967. 

  33968.   memset(&fileId, 0, sizeof(fileId));

  33969.   fileId.dev = statbuf.st_dev;

  33970. #if OS_VXWORKS

  33971.   fileId.pId = pFile->pId;

  33972. #else

  33973.   fileId.ino = (u64)statbuf.st_ino;

  33974. #endif

  33975.   assert( unixMutexHeld() );

  33976.   pInode = inodeList;

  33977.   while( pInode && memcmp(&fileId, &pInode->fileId, sizeof(fileId)) ){

  33978.     pInode = pInode->pNext;

  33979.   }

  33980.   if( pInode==0 ){

  33981.     pInode = sqlite3_malloc64( sizeof(*pInode) );

  33982.     if( pInode==0 ){

  33983.       return SQLITE_NOMEM_BKPT;

  33984.     }

  33985.     memset(pInode, 0, sizeof(*pInode));

  33986.     memcpy(&pInode->fileId, &fileId, sizeof(fileId));

  33987.     if( sqlite3GlobalConfig.bCoreMutex ){

  33988.       pInode->pLockMutex = sqlite3_mutex_alloc(SQLITE_MUTEX_FAST);

  33989.       if( pInode->pLockMutex==0 ){

  33990.         sqlite3_free(pInode);

  33991.         return SQLITE_NOMEM_BKPT;

  33992.       }

  33993.     }

  33994.     pInode->nRef = 1;

  33995.     assert( unixMutexHeld() );

  33996.     pInode->pNext = inodeList;

  33997.     pInode->pPrev = 0;

  33998.     if( inodeList ) inodeList->pPrev = pInode;

  33999.     inodeList = pInode;

  34000.   }else{

  34001.     pInode->nRef++;

  34002.   }

  34003.   *ppInode = pInode;

  34004.   return SQLITE_OK;

  34005. }

  34006. 

  34007. /*

  34008. ** Return TRUE if pFile has been renamed or unlinked since it was first opened.

  34009. */

  34010. static int fileHasMoved(unixFile *pFile){

  34011. #if OS_VXWORKS

  34012.   return pFile->pInode!=0 && pFile->pId!=pFile->pInode->fileId.pId;

  34013. #else

  34014.   struct stat buf;

  34015.   return pFile->pInode!=0 &&

  34016.       (osStat(pFile->zPath, &buf)!=0 

  34017.          || (u64)buf.st_ino!=pFile->pInode->fileId.ino);

  34018. #endif

  34019. }

  34020. 

  34021. 

  34022. /*

  34023. ** Check a unixFile that is a database.  Verify the following:

  34024. **

  34025. ** (1) There is exactly one hard link on the file

  34026. ** (2) The file is not a symbolic link

  34027. ** (3) The file has not been renamed or unlinked

  34028. **

  34029. ** Issue sqlite3_log(SQLITE_WARNING,...) messages if anything is not right.

  34030. */

  34031. static void verifyDbFile(unixFile *pFile){

  34032.   struct stat buf;

  34033.   int rc;

  34034. 

  34035.   /* These verifications occurs for the main database only */

  34036.   if( pFile->ctrlFlags & UNIXFILE_NOLOCK ) return;

  34037. 

  34038.   rc = osFstat(pFile->h, &buf);

  34039.   if( rc!=0 ){

  34040.     sqlite3_log(SQLITE_WARNING, "cannot fstat db file %s", pFile->zPath);

  34041.     return;

  34042.   }

  34043.   if( buf.st_nlink==0 ){

  34044.     sqlite3_log(SQLITE_WARNING, "file unlinked while open: %s", pFile->zPath);

  34045.     return;

  34046.   }

  34047.   if( buf.st_nlink>1 ){

  34048.     sqlite3_log(SQLITE_WARNING, "multiple links to file: %s", pFile->zPath);

  34049.     return;

  34050.   }

  34051.   if( fileHasMoved(pFile) ){

  34052.     sqlite3_log(SQLITE_WARNING, "file renamed while open: %s", pFile->zPath);

  34053.     return;

  34054.   }

  34055. }

  34056. 

  34057. 

  34058. /*

  34059. ** This routine checks if there is a RESERVED lock held on the specified

  34060. ** file by this or any other process. If such a lock is held, set *pResOut

  34061. ** to a non-zero value otherwise *pResOut is set to zero.  The return value

  34062. ** is set to SQLITE_OK unless an I/O error occurs during lock checking.

  34063. */

  34064. static int unixCheckReservedLock(sqlite3_file *id, int *pResOut){

  34065.   int rc = SQLITE_OK;

  34066.   int reserved = 0;

  34067.   unixFile *pFile = (unixFile*)id;

  34068. 

  34069.   SimulateIOError( return SQLITE_IOERR_CHECKRESERVEDLOCK; );

  34070. 

  34071.   assert( pFile );

  34072.   assert( pFile->eFileLock<=SHARED_LOCK );

  34073.   sqlite3_mutex_enter(pFile->pInode->pLockMutex);

  34074. 

  34075.   /* Check if a thread in this process holds such a lock */

  34076.   if( pFile->pInode->eFileLock>SHARED_LOCK ){

  34077.     reserved = 1;

  34078.   }

  34079. 

  34080.   /* Otherwise see if some other process holds it.

  34081.   */

  34082. #ifndef __DJGPP__

  34083.   if( !reserved && !pFile->pInode->bProcessLock ){

  34084.     struct flock lock;

  34085.     lock.l_whence = SEEK_SET;

  34086.     lock.l_start = RESERVED_BYTE;

  34087.     lock.l_len = 1;

  34088.     lock.l_type = F_WRLCK;

  34089.     if( osFcntl(pFile->h, F_GETLK, &lock) ){

  34090.       rc = SQLITE_IOERR_CHECKRESERVEDLOCK;

  34091.       storeLastErrno(pFile, errno);

  34092.     } else if( lock.l_type!=F_UNLCK ){

  34093.       reserved = 1;

  34094.     }

  34095.   }

  34096. #endif

  34097.   

  34098.   sqlite3_mutex_leave(pFile->pInode->pLockMutex);

  34099.   OSTRACE(("TEST WR-LOCK %d %d %d (unix)\n", pFile->h, rc, reserved));

  34100. 

  34101.   *pResOut = reserved;

  34102.   return rc;

  34103. }

  34104. 

  34105. /*

  34106. ** Set a posix-advisory-lock.

  34107. **

  34108. ** There are two versions of this routine.  If compiled with

  34109. ** SQLITE_ENABLE_SETLK_TIMEOUT then the routine has an extra parameter

  34110. ** which is a pointer to a unixFile.  If the unixFile->iBusyTimeout

  34111. ** value is set, then it is the number of milliseconds to wait before

  34112. ** failing the lock.  The iBusyTimeout value is always reset back to

  34113. ** zero on each call.

  34114. **

  34115. ** If SQLITE_ENABLE_SETLK_TIMEOUT is not defined, then do a non-blocking

  34116. ** attempt to set the lock.

  34117. */

  34118. #ifndef SQLITE_ENABLE_SETLK_TIMEOUT

  34119. # define osSetPosixAdvisoryLock(h,x,t) osFcntl(h,F_SETLK,x)

  34120. #else

  34121. static int osSetPosixAdvisoryLock(

  34122.   int h,                /* The file descriptor on which to take the lock */

  34123.   struct flock *pLock,  /* The description of the lock */

  34124.   unixFile *pFile       /* Structure holding timeout value */

  34125. ){

  34126.   int rc = osFcntl(h,F_SETLK,pLock);

  34127.   while( rc<0 && pFile->iBusyTimeout>0 ){

  34128.     /* On systems that support some kind of blocking file lock with a timeout,

  34129.     ** make appropriate changes here to invoke that blocking file lock.  On

  34130.     ** generic posix, however, there is no such API.  So we simply try the

  34131.     ** lock once every millisecond until either the timeout expires, or until

  34132.     ** the lock is obtained. */

  34133.     usleep(1000);

  34134.     rc = osFcntl(h,F_SETLK,pLock);

  34135.     pFile->iBusyTimeout--;

  34136.   }

  34137.   return rc;

  34138. }

  34139. #endif /* SQLITE_ENABLE_SETLK_TIMEOUT */

  34140. 

  34141. 

  34142. /*

  34143. ** Attempt to set a system-lock on the file pFile.  The lock is 

  34144. ** described by pLock.

  34145. **

  34146. ** If the pFile was opened read/write from unix-excl, then the only lock

  34147. ** ever obtained is an exclusive lock, and it is obtained exactly once

  34148. ** the first time any lock is attempted.  All subsequent system locking

  34149. ** operations become no-ops.  Locking operations still happen internally,

  34150. ** in order to coordinate access between separate database connections

  34151. ** within this process, but all of that is handled in memory and the

  34152. ** operating system does not participate.

  34153. **

  34154. ** This function is a pass-through to fcntl(F_SETLK) if pFile is using

  34155. ** any VFS other than "unix-excl" or if pFile is opened on "unix-excl"

  34156. ** and is read-only.

  34157. **

  34158. ** Zero is returned if the call completes successfully, or -1 if a call

  34159. ** to fcntl() fails. In this case, errno is set appropriately (by fcntl()).

  34160. */

  34161. static int unixFileLock(unixFile *pFile, struct flock *pLock){

  34162.   int rc;

  34163.   unixInodeInfo *pInode = pFile->pInode;

  34164.   assert( pInode!=0 );

  34165.   assert( sqlite3_mutex_held(pInode->pLockMutex) );

  34166.   if( (pFile->ctrlFlags & (UNIXFILE_EXCL|UNIXFILE_RDONLY))==UNIXFILE_EXCL ){

  34167.     if( pInode->bProcessLock==0 ){

  34168.       struct flock lock;

  34169.       assert( pInode->nLock==0 );

  34170.       lock.l_whence = SEEK_SET;

  34171.       lock.l_start = SHARED_FIRST;

  34172.       lock.l_len = SHARED_SIZE;

  34173.       lock.l_type = F_WRLCK;

  34174.       rc = osSetPosixAdvisoryLock(pFile->h, &lock, pFile);

  34175.       if( rc<0 ) return rc;

  34176.       pInode->bProcessLock = 1;

  34177.       pInode->nLock++;

  34178.     }else{

  34179.       rc = 0;

  34180.     }

  34181.   }else{

  34182.     rc = osSetPosixAdvisoryLock(pFile->h, pLock, pFile);

  34183.   }

  34184.   return rc;

  34185. }

  34186. 

  34187. /*

  34188. ** Lock the file with the lock specified by parameter eFileLock - one

  34189. ** of the following:

  34190. **

  34191. **     (1) SHARED_LOCK

  34192. **     (2) RESERVED_LOCK

  34193. **     (3) PENDING_LOCK

  34194. **     (4) EXCLUSIVE_LOCK

  34195. **

  34196. ** Sometimes when requesting one lock state, additional lock states

  34197. ** are inserted in between.  The locking might fail on one of the later

  34198. ** transitions leaving the lock state different from what it started but

  34199. ** still short of its goal.  The following chart shows the allowed

  34200. ** transitions and the inserted intermediate states:

  34201. **

  34202. **    UNLOCKED -> SHARED

  34203. **    SHARED -> RESERVED

  34204. **    SHARED -> (PENDING) -> EXCLUSIVE

  34205. **    RESERVED -> (PENDING) -> EXCLUSIVE

  34206. **    PENDING -> EXCLUSIVE

  34207. **

  34208. ** This routine will only increase a lock.  Use the sqlite3OsUnlock()

  34209. ** routine to lower a locking level.

  34210. */

  34211. static int unixLock(sqlite3_file *id, int eFileLock){

  34212.   /* The following describes the implementation of the various locks and

  34213.   ** lock transitions in terms of the POSIX advisory shared and exclusive

  34214.   ** lock primitives (called read-locks and write-locks below, to avoid

  34215.   ** confusion with SQLite lock names). The algorithms are complicated

  34216.   ** slightly in order to be compatible with Windows95 systems simultaneously

  34217.   ** accessing the same database file, in case that is ever required.

  34218.   **

  34219.   ** Symbols defined in os.h indentify the 'pending byte' and the 'reserved

  34220.   ** byte', each single bytes at well known offsets, and the 'shared byte

  34221.   ** range', a range of 510 bytes at a well known offset.

  34222.   **

  34223.   ** To obtain a SHARED lock, a read-lock is obtained on the 'pending

  34224.   ** byte'.  If this is successful, 'shared byte range' is read-locked

  34225.   ** and the lock on the 'pending byte' released.  (Legacy note:  When

  34226.   ** SQLite was first developed, Windows95 systems were still very common,

  34227.   ** and Widnows95 lacks a shared-lock capability.  So on Windows95, a

  34228.   ** single randomly selected by from the 'shared byte range' is locked.

  34229.   ** Windows95 is now pretty much extinct, but this work-around for the

  34230.   ** lack of shared-locks on Windows95 lives on, for backwards

  34231.   ** compatibility.)

  34232.   **

  34233.   ** A process may only obtain a RESERVED lock after it has a SHARED lock.

  34234.   ** A RESERVED lock is implemented by grabbing a write-lock on the

  34235.   ** 'reserved byte'. 

  34236.   **

  34237.   ** A process may only obtain a PENDING lock after it has obtained a

  34238.   ** SHARED lock. A PENDING lock is implemented by obtaining a write-lock

  34239.   ** on the 'pending byte'. This ensures that no new SHARED locks can be

  34240.   ** obtained, but existing SHARED locks are allowed to persist. A process

  34241.   ** does not have to obtain a RESERVED lock on the way to a PENDING lock.

  34242.   ** This property is used by the algorithm for rolling back a journal file

  34243.   ** after a crash.

  34244.   **

  34245.   ** An EXCLUSIVE lock, obtained after a PENDING lock is held, is

  34246.   ** implemented by obtaining a write-lock on the entire 'shared byte

  34247.   ** range'. Since all other locks require a read-lock on one of the bytes

  34248.   ** within this range, this ensures that no other locks are held on the

  34249.   ** database. 

  34250.   */

  34251.   int rc = SQLITE_OK;

  34252.   unixFile *pFile = (unixFile*)id;

  34253.   unixInodeInfo *pInode;

  34254.   struct flock lock;

  34255.   int tErrno = 0;

  34256. 

  34257.   assert( pFile );

  34258.   OSTRACE(("LOCK    %d %s was %s(%s,%d) pid=%d (unix)\n", pFile->h,

  34259.       azFileLock(eFileLock), azFileLock(pFile->eFileLock),

  34260.       azFileLock(pFile->pInode->eFileLock), pFile->pInode->nShared,

  34261.       osGetpid(0)));

  34262. 

  34263.   /* If there is already a lock of this type or more restrictive on the

  34264.   ** unixFile, do nothing. Don't use the end_lock: exit path, as

  34265.   ** unixEnterMutex() hasn't been called yet.

  34266.   */

  34267.   if( pFile->eFileLock>=eFileLock ){

  34268.     OSTRACE(("LOCK    %d %s ok (already held) (unix)\n", pFile->h,

  34269.             azFileLock(eFileLock)));

  34270.     return SQLITE_OK;

  34271.   }

  34272. 

  34273.   /* Make sure the locking sequence is correct.

  34274.   **  (1) We never move from unlocked to anything higher than shared lock.

  34275.   **  (2) SQLite never explicitly requests a pendig lock.

  34276.   **  (3) A shared lock is always held when a reserve lock is requested.

  34277.   */

  34278.   assert( pFile->eFileLock!=NO_LOCK || eFileLock==SHARED_LOCK );

  34279.   assert( eFileLock!=PENDING_LOCK );

  34280.   assert( eFileLock!=RESERVED_LOCK || pFile->eFileLock==SHARED_LOCK );

  34281. 

  34282.   /* This mutex is needed because pFile->pInode is shared across threads

  34283.   */

  34284.   pInode = pFile->pInode;

  34285.   sqlite3_mutex_enter(pInode->pLockMutex);

  34286. 

  34287.   /* If some thread using this PID has a lock via a different unixFile*

  34288.   ** handle that precludes the requested lock, return BUSY.

  34289.   */

  34290.   if( (pFile->eFileLock!=pInode->eFileLock && 

  34291.           (pInode->eFileLock>=PENDING_LOCK || eFileLock>SHARED_LOCK))

  34292.   ){

  34293.     rc = SQLITE_BUSY;

  34294.     goto end_lock;

  34295.   }

  34296. 

  34297.   /* If a SHARED lock is requested, and some thread using this PID already

  34298.   ** has a SHARED or RESERVED lock, then increment reference counts and

  34299.   ** return SQLITE_OK.

  34300.   */

  34301.   if( eFileLock==SHARED_LOCK && 

  34302.       (pInode->eFileLock==SHARED_LOCK || pInode->eFileLock==RESERVED_LOCK) ){

  34303.     assert( eFileLock==SHARED_LOCK );

  34304.     assert( pFile->eFileLock==0 );

  34305.     assert( pInode->nShared>0 );

  34306.     pFile->eFileLock = SHARED_LOCK;

  34307.     pInode->nShared++;

  34308.     pInode->nLock++;

  34309.     goto end_lock;

  34310.   }

  34311. 

  34312. 

  34313.   /* A PENDING lock is needed before acquiring a SHARED lock and before

  34314.   ** acquiring an EXCLUSIVE lock.  For the SHARED lock, the PENDING will

  34315.   ** be released.

  34316.   */

  34317.   lock.l_len = 1L;

  34318.   lock.l_whence = SEEK_SET;

  34319.   if( eFileLock==SHARED_LOCK 

  34320.       || (eFileLock==EXCLUSIVE_LOCK && pFile->eFileLock<PENDING_LOCK)

  34321.   ){

  34322.     lock.l_type = (eFileLock==SHARED_LOCK?F_RDLCK:F_WRLCK);

  34323.     lock.l_start = PENDING_BYTE;

  34324.     if( unixFileLock(pFile, &lock) ){

  34325.       tErrno = errno;

  34326.       rc = sqliteErrorFromPosixError(tErrno, SQLITE_IOERR_LOCK);

  34327.       if( rc!=SQLITE_BUSY ){

  34328.         storeLastErrno(pFile, tErrno);

  34329.       }

  34330.       goto end_lock;

  34331.     }

  34332.   }

  34333. 

  34334. 

  34335.   /* If control gets to this point, then actually go ahead and make

  34336.   ** operating system calls for the specified lock.

  34337.   */

  34338.   if( eFileLock==SHARED_LOCK ){

  34339.     assert( pInode->nShared==0 );

  34340.     assert( pInode->eFileLock==0 );

  34341.     assert( rc==SQLITE_OK );

  34342. 

  34343.     /* Now get the read-lock */

  34344.     lock.l_start = SHARED_FIRST;

  34345.     lock.l_len = SHARED_SIZE;

  34346.     if( unixFileLock(pFile, &lock) ){

  34347.       tErrno = errno;

  34348.       rc = sqliteErrorFromPosixError(tErrno, SQLITE_IOERR_LOCK);

  34349.     }

  34350. 

  34351.     /* Drop the temporary PENDING lock */

  34352.     lock.l_start = PENDING_BYTE;

  34353.     lock.l_len = 1L;

  34354.     lock.l_type = F_UNLCK;

  34355.     if( unixFileLock(pFile, &lock) && rc==SQLITE_OK ){

  34356.       /* This could happen with a network mount */

  34357.       tErrno = errno;

  34358.       rc = SQLITE_IOERR_UNLOCK; 

  34359.     }

  34360. 

  34361.     if( rc ){

  34362.       if( rc!=SQLITE_BUSY ){

  34363.         storeLastErrno(pFile, tErrno);

  34364.       }

  34365.       goto end_lock;

  34366.     }else{

  34367.       pFile->eFileLock = SHARED_LOCK;

  34368.       pInode->nLock++;

  34369.       pInode->nShared = 1;

  34370.     }

  34371.   }else if( eFileLock==EXCLUSIVE_LOCK && pInode->nShared>1 ){

  34372.     /* We are trying for an exclusive lock but another thread in this

  34373.     ** same process is still holding a shared lock. */

  34374.     rc = SQLITE_BUSY;

  34375.   }else{

  34376.     /* The request was for a RESERVED or EXCLUSIVE lock.  It is

  34377.     ** assumed that there is a SHARED or greater lock on the file

  34378.     ** already.

  34379.     */

  34380.     assert( 0!=pFile->eFileLock );

  34381.     lock.l_type = F_WRLCK;

  34382. 

  34383.     assert( eFileLock==RESERVED_LOCK || eFileLock==EXCLUSIVE_LOCK );

  34384.     if( eFileLock==RESERVED_LOCK ){

  34385.       lock.l_start = RESERVED_BYTE;

  34386.       lock.l_len = 1L;

  34387.     }else{

  34388.       lock.l_start = SHARED_FIRST;

  34389.       lock.l_len = SHARED_SIZE;

  34390.     }

  34391. 

  34392.     if( unixFileLock(pFile, &lock) ){

  34393.       tErrno = errno;

  34394.       rc = sqliteErrorFromPosixError(tErrno, SQLITE_IOERR_LOCK);

  34395.       if( rc!=SQLITE_BUSY ){

  34396.         storeLastErrno(pFile, tErrno);

  34397.       }

  34398.     }

  34399.   }

  34400.   

  34401. 

  34402. #ifdef SQLITE_DEBUG

  34403.   /* Set up the transaction-counter change checking flags when

  34404.   ** transitioning from a SHARED to a RESERVED lock.  The change

  34405.   ** from SHARED to RESERVED marks the beginning of a normal

  34406.   ** write operation (not a hot journal rollback).

  34407.   */

  34408.   if( rc==SQLITE_OK

  34409.    && pFile->eFileLock<=SHARED_LOCK

  34410.    && eFileLock==RESERVED_LOCK

  34411.   ){

  34412.     pFile->transCntrChng = 0;

  34413.     pFile->dbUpdate = 0;

  34414.     pFile->inNormalWrite = 1;

  34415.   }

  34416. #endif

  34417. 

  34418. 

  34419.   if( rc==SQLITE_OK ){

  34420.     pFile->eFileLock = eFileLock;

  34421.     pInode->eFileLock = eFileLock;

  34422.   }else if( eFileLock==EXCLUSIVE_LOCK ){

  34423.     pFile->eFileLock = PENDING_LOCK;

  34424.     pInode->eFileLock = PENDING_LOCK;

  34425.   }

  34426. 

  34427. end_lock:

  34428.   sqlite3_mutex_leave(pInode->pLockMutex);

  34429.   OSTRACE(("LOCK    %d %s %s (unix)\n", pFile->h, azFileLock(eFileLock), 

  34430.       rc==SQLITE_OK ? "ok" : "failed"));

  34431.   return rc;

  34432. }

  34433. 

  34434. /*

  34435. ** Add the file descriptor used by file handle pFile to the corresponding

  34436. ** pUnused list.

  34437. */

  34438. static void setPendingFd(unixFile *pFile){

  34439.   unixInodeInfo *pInode = pFile->pInode;

  34440.   UnixUnusedFd *p = pFile->pPreallocatedUnused;

  34441.   assert( unixFileMutexHeld(pFile) );

  34442.   p->pNext = pInode->pUnused;

  34443.   pInode->pUnused = p;

  34444.   pFile->h = -1;

  34445.   pFile->pPreallocatedUnused = 0;

  34446. }

  34447. 

  34448. /*

  34449. ** Lower the locking level on file descriptor pFile to eFileLock.  eFileLock

  34450. ** must be either NO_LOCK or SHARED_LOCK.

  34451. **

  34452. ** If the locking level of the file descriptor is already at or below

  34453. ** the requested locking level, this routine is a no-op.

  34454. ** 

  34455. ** If handleNFSUnlock is true, then on downgrading an EXCLUSIVE_LOCK to SHARED

  34456. ** the byte range is divided into 2 parts and the first part is unlocked then

  34457. ** set to a read lock, then the other part is simply unlocked.  This works 

  34458. ** around a bug in BSD NFS lockd (also seen on MacOSX 10.3+) that fails to 

  34459. ** remove the write lock on a region when a read lock is set.

  34460. */

  34461. static int posixUnlock(sqlite3_file *id, int eFileLock, int handleNFSUnlock){

  34462.   unixFile *pFile = (unixFile*)id;

  34463.   unixInodeInfo *pInode;

  34464.   struct flock lock;

  34465.   int rc = SQLITE_OK;

  34466. 

  34467.   assert( pFile );

  34468.   OSTRACE(("UNLOCK  %d %d was %d(%d,%d) pid=%d (unix)\n", pFile->h, eFileLock,

  34469.       pFile->eFileLock, pFile->pInode->eFileLock, pFile->pInode->nShared,

  34470.       osGetpid(0)));

  34471. 

  34472.   assert( eFileLock<=SHARED_LOCK );

  34473.   if( pFile->eFileLock<=eFileLock ){

  34474.     return SQLITE_OK;

  34475.   }

  34476.   pInode = pFile->pInode;

  34477.   sqlite3_mutex_enter(pInode->pLockMutex);

  34478.   assert( pInode->nShared!=0 );

  34479.   if( pFile->eFileLock>SHARED_LOCK ){

  34480.     assert( pInode->eFileLock==pFile->eFileLock );

  34481. 

  34482. #ifdef SQLITE_DEBUG

  34483.     /* When reducing a lock such that other processes can start

  34484.     ** reading the database file again, make sure that the

  34485.     ** transaction counter was updated if any part of the database

  34486.     ** file changed.  If the transaction counter is not updated,

  34487.     ** other connections to the same file might not realize that

  34488.     ** the file has changed and hence might not know to flush their

  34489.     ** cache.  The use of a stale cache can lead to database corruption.

  34490.     */

  34491.     pFile->inNormalWrite = 0;

  34492. #endif

  34493. 

  34494.     /* downgrading to a shared lock on NFS involves clearing the write lock

  34495.     ** before establishing the readlock - to avoid a race condition we downgrade

  34496.     ** the lock in 2 blocks, so that part of the range will be covered by a 

  34497.     ** write lock until the rest is covered by a read lock:

  34498.     **  1:   [WWWWW]

  34499.     **  2:   [....W]

  34500.     **  3:   [RRRRW]

  34501.     **  4:   [RRRR.]

  34502.     */

  34503.     if( eFileLock==SHARED_LOCK ){

  34504. #if !defined(__APPLE__) || !SQLITE_ENABLE_LOCKING_STYLE

  34505.       (void)handleNFSUnlock;

  34506.       assert( handleNFSUnlock==0 );

  34507. #endif

  34508. #if defined(__APPLE__) && SQLITE_ENABLE_LOCKING_STYLE

  34509.       if( handleNFSUnlock ){

  34510.         int tErrno;               /* Error code from system call errors */

  34511.         off_t divSize = SHARED_SIZE - 1;

  34512.         

  34513.         lock.l_type = F_UNLCK;

  34514.         lock.l_whence = SEEK_SET;

  34515.         lock.l_start = SHARED_FIRST;

  34516.         lock.l_len = divSize;

  34517.         if( unixFileLock(pFile, &lock)==(-1) ){

  34518.           tErrno = errno;

  34519.           rc = SQLITE_IOERR_UNLOCK;

  34520.           storeLastErrno(pFile, tErrno);

  34521.           goto end_unlock;

  34522.         }

  34523.         lock.l_type = F_RDLCK;

  34524.         lock.l_whence = SEEK_SET;

  34525.         lock.l_start = SHARED_FIRST;

  34526.         lock.l_len = divSize;

  34527.         if( unixFileLock(pFile, &lock)==(-1) ){

  34528.           tErrno = errno;

  34529.           rc = sqliteErrorFromPosixError(tErrno, SQLITE_IOERR_RDLOCK);

  34530.           if( IS_LOCK_ERROR(rc) ){

  34531.             storeLastErrno(pFile, tErrno);

  34532.           }

  34533.           goto end_unlock;

  34534.         }

  34535.         lock.l_type = F_UNLCK;

  34536.         lock.l_whence = SEEK_SET;

  34537.         lock.l_start = SHARED_FIRST+divSize;

  34538.         lock.l_len = SHARED_SIZE-divSize;

  34539.         if( unixFileLock(pFile, &lock)==(-1) ){

  34540.           tErrno = errno;

  34541.           rc = SQLITE_IOERR_UNLOCK;

  34542.           storeLastErrno(pFile, tErrno);

  34543.           goto end_unlock;

  34544.         }

  34545.       }else

  34546. #endif /* defined(__APPLE__) && SQLITE_ENABLE_LOCKING_STYLE */

  34547.       {

  34548.         lock.l_type = F_RDLCK;

  34549.         lock.l_whence = SEEK_SET;

  34550.         lock.l_start = SHARED_FIRST;

  34551.         lock.l_len = SHARED_SIZE;

  34552.         if( unixFileLock(pFile, &lock) ){

  34553.           /* In theory, the call to unixFileLock() cannot fail because another

  34554.           ** process is holding an incompatible lock. If it does, this 

  34555.           ** indicates that the other process is not following the locking

  34556.           ** protocol. If this happens, return SQLITE_IOERR_RDLOCK. Returning

  34557.           ** SQLITE_BUSY would confuse the upper layer (in practice it causes 

  34558.           ** an assert to fail). */ 

  34559.           rc = SQLITE_IOERR_RDLOCK;

  34560.           storeLastErrno(pFile, errno);

  34561.           goto end_unlock;

  34562.         }

  34563.       }

  34564.     }

  34565.     lock.l_type = F_UNLCK;

  34566.     lock.l_whence = SEEK_SET;

  34567.     lock.l_start = PENDING_BYTE;

  34568.     lock.l_len = 2L;  assert( PENDING_BYTE+1==RESERVED_BYTE );

  34569.     if( unixFileLock(pFile, &lock)==0 ){

  34570.       pInode->eFileLock = SHARED_LOCK;

  34571.     }else{

  34572.       rc = SQLITE_IOERR_UNLOCK;

  34573.       storeLastErrno(pFile, errno);

  34574.       goto end_unlock;

  34575.     }

  34576.   }

  34577.   if( eFileLock==NO_LOCK ){

  34578.     /* Decrement the shared lock counter.  Release the lock using an

  34579.     ** OS call only when all threads in this same process have released

  34580.     ** the lock.

  34581.     */

  34582.     pInode->nShared--;

  34583.     if( pInode->nShared==0 ){

  34584.       lock.l_type = F_UNLCK;

  34585.       lock.l_whence = SEEK_SET;

  34586.       lock.l_start = lock.l_len = 0L;

  34587.       if( unixFileLock(pFile, &lock)==0 ){

  34588.         pInode->eFileLock = NO_LOCK;

  34589.       }else{

  34590.         rc = SQLITE_IOERR_UNLOCK;

  34591.         storeLastErrno(pFile, errno);

  34592.         pInode->eFileLock = NO_LOCK;

  34593.         pFile->eFileLock = NO_LOCK;

  34594.       }

  34595.     }

  34596. 

  34597.     /* Decrement the count of locks against this same file.  When the

  34598.     ** count reaches zero, close any other file descriptors whose close

  34599.     ** was deferred because of outstanding locks.

  34600.     */

  34601.     pInode->nLock--;

  34602.     assert( pInode->nLock>=0 );

  34603.     if( pInode->nLock==0 ) closePendingFds(pFile);

  34604.   }

  34605. 

  34606. end_unlock:

  34607.   sqlite3_mutex_leave(pInode->pLockMutex);

  34608.   if( rc==SQLITE_OK ){

  34609.     pFile->eFileLock = eFileLock;

  34610.   }

  34611.   return rc;

  34612. }

  34613. 

  34614. /*

  34615. ** Lower the locking level on file descriptor pFile to eFileLock.  eFileLock

  34616. ** must be either NO_LOCK or SHARED_LOCK.

  34617. **

  34618. ** If the locking level of the file descriptor is already at or below

  34619. ** the requested locking level, this routine is a no-op.

  34620. */

  34621. static int unixUnlock(sqlite3_file *id, int eFileLock){

  34622. #if SQLITE_MAX_MMAP_SIZE>0

  34623.   assert( eFileLock==SHARED_LOCK || ((unixFile *)id)->nFetchOut==0 );

  34624. #endif

  34625.   return posixUnlock(id, eFileLock, 0);

  34626. }

  34627. 

  34628. #if SQLITE_MAX_MMAP_SIZE>0

  34629. static int unixMapfile(unixFile *pFd, i64 nByte);

  34630. static void unixUnmapfile(unixFile *pFd);

  34631. #endif

  34632. 

  34633. /*

  34634. ** This function performs the parts of the "close file" operation 

  34635. ** common to all locking schemes. It closes the directory and file

  34636. ** handles, if they are valid, and sets all fields of the unixFile

  34637. ** structure to 0.

  34638. **

  34639. ** It is *not* necessary to hold the mutex when this routine is called,

  34640. ** even on VxWorks.  A mutex will be acquired on VxWorks by the

  34641. ** vxworksReleaseFileId() routine.

  34642. */

  34643. static int closeUnixFile(sqlite3_file *id){

  34644.   unixFile *pFile = (unixFile*)id;

  34645. #if SQLITE_MAX_MMAP_SIZE>0

  34646.   unixUnmapfile(pFile);

  34647. #endif

  34648.   if( pFile->h>=0 ){

  34649.     robust_close(pFile, pFile->h, __LINE__);

  34650.     pFile->h = -1;

  34651.   }

  34652. #if OS_VXWORKS

  34653.   if( pFile->pId ){

  34654.     if( pFile->ctrlFlags & UNIXFILE_DELETE ){

  34655.       osUnlink(pFile->pId->zCanonicalName);

  34656.     }

  34657.     vxworksReleaseFileId(pFile->pId);

  34658.     pFile->pId = 0;

  34659.   }

  34660. #endif

  34661. #ifdef SQLITE_UNLINK_AFTER_CLOSE

  34662.   if( pFile->ctrlFlags & UNIXFILE_DELETE ){

  34663.     osUnlink(pFile->zPath);

  34664.     sqlite3_free(*(char**)&pFile->zPath);

  34665.     pFile->zPath = 0;

  34666.   }

  34667. #endif

  34668.   OSTRACE(("CLOSE   %-3d\n", pFile->h));

  34669.   OpenCounter(-1);

  34670.   sqlite3_free(pFile->pPreallocatedUnused);

  34671.   memset(pFile, 0, sizeof(unixFile));

  34672.   return SQLITE_OK;

  34673. }

  34674. 

  34675. /*

  34676. ** Close a file.

  34677. */

  34678. static int unixClose(sqlite3_file *id){

  34679.   int rc = SQLITE_OK;

  34680.   unixFile *pFile = (unixFile *)id;

  34681.   unixInodeInfo *pInode = pFile->pInode;

  34682. 

  34683.   assert( pInode!=0 );

  34684.   verifyDbFile(pFile);

  34685.   unixUnlock(id, NO_LOCK);

  34686.   assert( unixFileMutexNotheld(pFile) );

  34687.   unixEnterMutex();

  34688. 

  34689.   /* unixFile.pInode is always valid here. Otherwise, a different close

  34690.   ** routine (e.g. nolockClose()) would be called instead.

  34691.   */

  34692.   assert( pFile->pInode->nLock>0 || pFile->pInode->bProcessLock==0 );

  34693.   sqlite3_mutex_enter(pInode->pLockMutex);

  34694.   if( pInode->nLock ){

  34695.     /* If there are outstanding locks, do not actually close the file just

  34696.     ** yet because that would clear those locks.  Instead, add the file

  34697.     ** descriptor to pInode->pUnused list.  It will be automatically closed 

  34698.     ** when the last lock is cleared.

  34699.     */

  34700.     setPendingFd(pFile);

  34701.   }

  34702.   sqlite3_mutex_leave(pInode->pLockMutex);

  34703.   releaseInodeInfo(pFile);

  34704.   rc = closeUnixFile(id);

  34705.   unixLeaveMutex();

  34706.   return rc;

  34707. }

  34708. 

  34709. /************** End of the posix advisory lock implementation *****************

  34710. ******************************************************************************/

  34711. 

  34712. /******************************************************************************

  34713. ****************************** No-op Locking **********************************

  34714. **

  34715. ** Of the various locking implementations available, this is by far the

  34716. ** simplest:  locking is ignored.  No attempt is made to lock the database

  34717. ** file for reading or writing.

  34718. **

  34719. ** This locking mode is appropriate for use on read-only databases

  34720. ** (ex: databases that are burned into CD-ROM, for example.)  It can

  34721. ** also be used if the application employs some external mechanism to

  34722. ** prevent simultaneous access of the same database by two or more

  34723. ** database connections.  But there is a serious risk of database

  34724. ** corruption if this locking mode is used in situations where multiple

  34725. ** database connections are accessing the same database file at the same

  34726. ** time and one or more of those connections are writing.

  34727. */

  34728. 

  34729. static int nolockCheckReservedLock(sqlite3_file *NotUsed, int *pResOut){

  34730.   UNUSED_PARAMETER(NotUsed);

  34731.   *pResOut = 0;

  34732.   return SQLITE_OK;

  34733. }

  34734. static int nolockLock(sqlite3_file *NotUsed, int NotUsed2){

  34735.   UNUSED_PARAMETER2(NotUsed, NotUsed2);

  34736.   return SQLITE_OK;

  34737. }

  34738. static int nolockUnlock(sqlite3_file *NotUsed, int NotUsed2){

  34739.   UNUSED_PARAMETER2(NotUsed, NotUsed2);

  34740.   return SQLITE_OK;

  34741. }

  34742. 

  34743. /*

  34744. ** Close the file.

  34745. */

  34746. static int nolockClose(sqlite3_file *id) {

  34747.   return closeUnixFile(id);

  34748. }

  34749. 

  34750. /******************* End of the no-op lock implementation *********************

  34751. ******************************************************************************/

  34752. 

  34753. /******************************************************************************

  34754. ************************* Begin dot-file Locking ******************************

  34755. **

  34756. ** The dotfile locking implementation uses the existence of separate lock

  34757. ** files (really a directory) to control access to the database.  This works

  34758. ** on just about every filesystem imaginable.  But there are serious downsides:

  34759. **

  34760. **    (1)  There is zero concurrency.  A single reader blocks all other

  34761. **         connections from reading or writing the database.

  34762. **

  34763. **    (2)  An application crash or power loss can leave stale lock files

  34764. **         sitting around that need to be cleared manually.

  34765. **

  34766. ** Nevertheless, a dotlock is an appropriate locking mode for use if no

  34767. ** other locking strategy is available.

  34768. **

  34769. ** Dotfile locking works by creating a subdirectory in the same directory as

  34770. ** the database and with the same name but with a ".lock" extension added.

  34771. ** The existence of a lock directory implies an EXCLUSIVE lock.  All other

  34772. ** lock types (SHARED, RESERVED, PENDING) are mapped into EXCLUSIVE.

  34773. */

  34774. 

  34775. /*

  34776. ** The file suffix added to the data base filename in order to create the

  34777. ** lock directory.

  34778. */

  34779. #define DOTLOCK_SUFFIX ".lock"

  34780. 

  34781. /*

  34782. ** This routine checks if there is a RESERVED lock held on the specified

  34783. ** file by this or any other process. If such a lock is held, set *pResOut

  34784. ** to a non-zero value otherwise *pResOut is set to zero.  The return value

  34785. ** is set to SQLITE_OK unless an I/O error occurs during lock checking.

  34786. **

  34787. ** In dotfile locking, either a lock exists or it does not.  So in this

  34788. ** variation of CheckReservedLock(), *pResOut is set to true if any lock

  34789. ** is held on the file and false if the file is unlocked.

  34790. */

  34791. static int dotlockCheckReservedLock(sqlite3_file *id, int *pResOut) {

  34792.   int rc = SQLITE_OK;

  34793.   int reserved = 0;

  34794.   unixFile *pFile = (unixFile*)id;

  34795. 

  34796.   SimulateIOError( return SQLITE_IOERR_CHECKRESERVEDLOCK; );

  34797.   

  34798.   assert( pFile );

  34799.   reserved = osAccess((const char*)pFile->lockingContext, 0)==0;

  34800.   OSTRACE(("TEST WR-LOCK %d %d %d (dotlock)\n", pFile->h, rc, reserved));

  34801.   *pResOut = reserved;

  34802.   return rc;

  34803. }

  34804. 

  34805. /*

  34806. ** Lock the file with the lock specified by parameter eFileLock - one

  34807. ** of the following:

  34808. **

  34809. **     (1) SHARED_LOCK

  34810. **     (2) RESERVED_LOCK

  34811. **     (3) PENDING_LOCK

  34812. **     (4) EXCLUSIVE_LOCK

  34813. **

  34814. ** Sometimes when requesting one lock state, additional lock states

  34815. ** are inserted in between.  The locking might fail on one of the later

  34816. ** transitions leaving the lock state different from what it started but

  34817. ** still short of its goal.  The following chart shows the allowed

  34818. ** transitions and the inserted intermediate states:

  34819. **

  34820. **    UNLOCKED -> SHARED

  34821. **    SHARED -> RESERVED

  34822. **    SHARED -> (PENDING) -> EXCLUSIVE

  34823. **    RESERVED -> (PENDING) -> EXCLUSIVE

  34824. **    PENDING -> EXCLUSIVE

  34825. **

  34826. ** This routine will only increase a lock.  Use the sqlite3OsUnlock()

  34827. ** routine to lower a locking level.

  34828. **

  34829. ** With dotfile locking, we really only support state (4): EXCLUSIVE.

  34830. ** But we track the other locking levels internally.

  34831. */

  34832. static int dotlockLock(sqlite3_file *id, int eFileLock) {

  34833.   unixFile *pFile = (unixFile*)id;

  34834.   char *zLockFile = (char *)pFile->lockingContext;

  34835.   int rc = SQLITE_OK;

  34836. 

  34837. 

  34838.   /* If we have any lock, then the lock file already exists.  All we have

  34839.   ** to do is adjust our internal record of the lock level.

  34840.   */

  34841.   if( pFile->eFileLock > NO_LOCK ){

  34842.     pFile->eFileLock = eFileLock;

  34843.     /* Always update the timestamp on the old file */

  34844. #ifdef HAVE_UTIME

  34845.     utime(zLockFile, NULL);

  34846. #else

  34847.     utimes(zLockFile, NULL);

  34848. #endif

  34849.     return SQLITE_OK;

  34850.   }

  34851.   

  34852.   /* grab an exclusive lock */

  34853.   rc = osMkdir(zLockFile, 0777);

  34854.   if( rc<0 ){

  34855.     /* failed to open/create the lock directory */

  34856.     int tErrno = errno;

  34857.     if( EEXIST == tErrno ){

  34858.       rc = SQLITE_BUSY;

  34859.     } else {

  34860.       rc = sqliteErrorFromPosixError(tErrno, SQLITE_IOERR_LOCK);

  34861.       if( rc!=SQLITE_BUSY ){

  34862.         storeLastErrno(pFile, tErrno);

  34863.       }

  34864.     }

  34865.     return rc;

  34866.   } 

  34867.   

  34868.   /* got it, set the type and return ok */

  34869.   pFile->eFileLock = eFileLock;

  34870.   return rc;

  34871. }

  34872. 

  34873. /*

  34874. ** Lower the locking level on file descriptor pFile to eFileLock.  eFileLock

  34875. ** must be either NO_LOCK or SHARED_LOCK.

  34876. **

  34877. ** If the locking level of the file descriptor is already at or below

  34878. ** the requested locking level, this routine is a no-op.

  34879. **

  34880. ** When the locking level reaches NO_LOCK, delete the lock file.

  34881. */

  34882. static int dotlockUnlock(sqlite3_file *id, int eFileLock) {

  34883.   unixFile *pFile = (unixFile*)id;

  34884.   char *zLockFile = (char *)pFile->lockingContext;

  34885.   int rc;

  34886. 

  34887.   assert( pFile );

  34888.   OSTRACE(("UNLOCK  %d %d was %d pid=%d (dotlock)\n", pFile->h, eFileLock,

  34889.            pFile->eFileLock, osGetpid(0)));

  34890.   assert( eFileLock<=SHARED_LOCK );

  34891.   

  34892.   /* no-op if possible */

  34893.   if( pFile->eFileLock==eFileLock ){

  34894.     return SQLITE_OK;

  34895.   }

  34896. 

  34897.   /* To downgrade to shared, simply update our internal notion of the

  34898.   ** lock state.  No need to mess with the file on disk.

  34899.   */

  34900.   if( eFileLock==SHARED_LOCK ){

  34901.     pFile->eFileLock = SHARED_LOCK;

  34902.     return SQLITE_OK;

  34903.   }

  34904.   

  34905.   /* To fully unlock the database, delete the lock file */

  34906.   assert( eFileLock==NO_LOCK );

  34907.   rc = osRmdir(zLockFile);

  34908.   if( rc<0 ){

  34909.     int tErrno = errno;

  34910.     if( tErrno==ENOENT ){

  34911.       rc = SQLITE_OK;

  34912.     }else{

  34913.       rc = SQLITE_IOERR_UNLOCK;

  34914.       storeLastErrno(pFile, tErrno);

  34915.     }

  34916.     return rc; 

  34917.   }

  34918.   pFile->eFileLock = NO_LOCK;

  34919.   return SQLITE_OK;

  34920. }

  34921. 

  34922. /*

  34923. ** Close a file.  Make sure the lock has been released before closing.

  34924. */

  34925. static int dotlockClose(sqlite3_file *id) {

  34926.   unixFile *pFile = (unixFile*)id;

  34927.   assert( id!=0 );

  34928.   dotlockUnlock(id, NO_LOCK);

  34929.   sqlite3_free(pFile->lockingContext);

  34930.   return closeUnixFile(id);

  34931. }

  34932. /****************** End of the dot-file lock implementation *******************

  34933. ******************************************************************************/

  34934. 

  34935. /******************************************************************************

  34936. ************************** Begin flock Locking ********************************

  34937. **

  34938. ** Use the flock() system call to do file locking.

  34939. **

  34940. ** flock() locking is like dot-file locking in that the various

  34941. ** fine-grain locking levels supported by SQLite are collapsed into

  34942. ** a single exclusive lock.  In other words, SHARED, RESERVED, and

  34943. ** PENDING locks are the same thing as an EXCLUSIVE lock.  SQLite

  34944. ** still works when you do this, but concurrency is reduced since

  34945. ** only a single process can be reading the database at a time.

  34946. **

  34947. ** Omit this section if SQLITE_ENABLE_LOCKING_STYLE is turned off

  34948. */

  34949. #if SQLITE_ENABLE_LOCKING_STYLE

  34950. 

  34951. /*

  34952. ** Retry flock() calls that fail with EINTR

  34953. */

  34954. #ifdef EINTR

  34955. static int robust_flock(int fd, int op){

  34956.   int rc;

  34957.   do{ rc = flock(fd,op); }while( rc<0 && errno==EINTR );

  34958.   return rc;

  34959. }

  34960. #else

  34961. # define robust_flock(a,b) flock(a,b)

  34962. #endif

  34963.      

  34964. 

  34965. /*

  34966. ** This routine checks if there is a RESERVED lock held on the specified

  34967. ** file by this or any other process. If such a lock is held, set *pResOut

  34968. ** to a non-zero value otherwise *pResOut is set to zero.  The return value

  34969. ** is set to SQLITE_OK unless an I/O error occurs during lock checking.

  34970. */

  34971. static int flockCheckReservedLock(sqlite3_file *id, int *pResOut){

  34972.   int rc = SQLITE_OK;

  34973.   int reserved = 0;

  34974.   unixFile *pFile = (unixFile*)id;

  34975.   

  34976.   SimulateIOError( return SQLITE_IOERR_CHECKRESERVEDLOCK; );

  34977.   

  34978.   assert( pFile );

  34979.   

  34980.   /* Check if a thread in this process holds such a lock */

  34981.   if( pFile->eFileLock>SHARED_LOCK ){

  34982.     reserved = 1;

  34983.   }

  34984.   

  34985.   /* Otherwise see if some other process holds it. */

  34986.   if( !reserved ){

  34987.     /* attempt to get the lock */

  34988.     int lrc = robust_flock(pFile->h, LOCK_EX | LOCK_NB);

  34989.     if( !lrc ){

  34990.       /* got the lock, unlock it */

  34991.       lrc = robust_flock(pFile->h, LOCK_UN);

  34992.       if ( lrc ) {

  34993.         int tErrno = errno;

  34994.         /* unlock failed with an error */

  34995.         lrc = SQLITE_IOERR_UNLOCK; 

  34996.         storeLastErrno(pFile, tErrno);

  34997.         rc = lrc;

  34998.       }

  34999.     } else {

  35000.       int tErrno = errno;

  35001.       reserved = 1;

  35002.       /* someone else might have it reserved */

  35003.       lrc = sqliteErrorFromPosixError(tErrno, SQLITE_IOERR_LOCK); 

  35004.       if( IS_LOCK_ERROR(lrc) ){

  35005.         storeLastErrno(pFile, tErrno);

  35006.         rc = lrc;

  35007.       }

  35008.     }

  35009.   }

  35010.   OSTRACE(("TEST WR-LOCK %d %d %d (flock)\n", pFile->h, rc, reserved));

  35011. 

  35012. #ifdef SQLITE_IGNORE_FLOCK_LOCK_ERRORS

  35013.   if( (rc & 0xff) == SQLITE_IOERR ){

  35014.     rc = SQLITE_OK;

  35015.     reserved=1;

  35016.   }

  35017. #endif /* SQLITE_IGNORE_FLOCK_LOCK_ERRORS */

  35018.   *pResOut = reserved;

  35019.   return rc;

  35020. }

  35021. 

  35022. /*

  35023. ** Lock the file with the lock specified by parameter eFileLock - one

  35024. ** of the following:

  35025. **

  35026. **     (1) SHARED_LOCK

  35027. **     (2) RESERVED_LOCK

  35028. **     (3) PENDING_LOCK

  35029. **     (4) EXCLUSIVE_LOCK

  35030. **

  35031. ** Sometimes when requesting one lock state, additional lock states

  35032. ** are inserted in between.  The locking might fail on one of the later

  35033. ** transitions leaving the lock state different from what it started but

  35034. ** still short of its goal.  The following chart shows the allowed

  35035. ** transitions and the inserted intermediate states:

  35036. **

  35037. **    UNLOCKED -> SHARED

  35038. **    SHARED -> RESERVED

  35039. **    SHARED -> (PENDING) -> EXCLUSIVE

  35040. **    RESERVED -> (PENDING) -> EXCLUSIVE

  35041. **    PENDING -> EXCLUSIVE

  35042. **

  35043. ** flock() only really support EXCLUSIVE locks.  We track intermediate

  35044. ** lock states in the sqlite3_file structure, but all locks SHARED or

  35045. ** above are really EXCLUSIVE locks and exclude all other processes from

  35046. ** access the file.

  35047. **

  35048. ** This routine will only increase a lock.  Use the sqlite3OsUnlock()

  35049. ** routine to lower a locking level.

  35050. */

  35051. static int flockLock(sqlite3_file *id, int eFileLock) {

  35052.   int rc = SQLITE_OK;

  35053.   unixFile *pFile = (unixFile*)id;

  35054. 

  35055.   assert( pFile );

  35056. 

  35057.   /* if we already have a lock, it is exclusive.  

  35058.   ** Just adjust level and punt on outta here. */

  35059.   if (pFile->eFileLock > NO_LOCK) {

  35060.     pFile->eFileLock = eFileLock;

  35061.     return SQLITE_OK;

  35062.   }

  35063.   

  35064.   /* grab an exclusive lock */

  35065.   

  35066.   if (robust_flock(pFile->h, LOCK_EX | LOCK_NB)) {

  35067.     int tErrno = errno;

  35068.     /* didn't get, must be busy */

  35069.     rc = sqliteErrorFromPosixError(tErrno, SQLITE_IOERR_LOCK);

  35070.     if( IS_LOCK_ERROR(rc) ){

  35071.       storeLastErrno(pFile, tErrno);

  35072.     }

  35073.   } else {

  35074.     /* got it, set the type and return ok */

  35075.     pFile->eFileLock = eFileLock;

  35076.   }

  35077.   OSTRACE(("LOCK    %d %s %s (flock)\n", pFile->h, azFileLock(eFileLock), 

  35078.            rc==SQLITE_OK ? "ok" : "failed"));

  35079. #ifdef SQLITE_IGNORE_FLOCK_LOCK_ERRORS

  35080.   if( (rc & 0xff) == SQLITE_IOERR ){

  35081.     rc = SQLITE_BUSY;

  35082.   }

  35083. #endif /* SQLITE_IGNORE_FLOCK_LOCK_ERRORS */

  35084.   return rc;

  35085. }

  35086. 

  35087. 

  35088. /*

  35089. ** Lower the locking level on file descriptor pFile to eFileLock.  eFileLock

  35090. ** must be either NO_LOCK or SHARED_LOCK.

  35091. **

  35092. ** If the locking level of the file descriptor is already at or below

  35093. ** the requested locking level, this routine is a no-op.

  35094. */

  35095. static int flockUnlock(sqlite3_file *id, int eFileLock) {

  35096.   unixFile *pFile = (unixFile*)id;

  35097.   

  35098.   assert( pFile );

  35099.   OSTRACE(("UNLOCK  %d %d was %d pid=%d (flock)\n", pFile->h, eFileLock,

  35100.            pFile->eFileLock, osGetpid(0)));

  35101.   assert( eFileLock<=SHARED_LOCK );

  35102.   

  35103.   /* no-op if possible */

  35104.   if( pFile->eFileLock==eFileLock ){

  35105.     return SQLITE_OK;

  35106.   }

  35107.   

  35108.   /* shared can just be set because we always have an exclusive */

  35109.   if (eFileLock==SHARED_LOCK) {

  35110.     pFile->eFileLock = eFileLock;

  35111.     return SQLITE_OK;

  35112.   }

  35113.   

  35114.   /* no, really, unlock. */

  35115.   if( robust_flock(pFile->h, LOCK_UN) ){

  35116. #ifdef SQLITE_IGNORE_FLOCK_LOCK_ERRORS

  35117.     return SQLITE_OK;

  35118. #endif /* SQLITE_IGNORE_FLOCK_LOCK_ERRORS */

  35119.     return SQLITE_IOERR_UNLOCK;

  35120.   }else{

  35121.     pFile->eFileLock = NO_LOCK;

  35122.     return SQLITE_OK;

  35123.   }

  35124. }

  35125. 

  35126. /*

  35127. ** Close a file.

  35128. */

  35129. static int flockClose(sqlite3_file *id) {

  35130.   assert( id!=0 );

  35131.   flockUnlock(id, NO_LOCK);

  35132.   return closeUnixFile(id);

  35133. }

  35134. 

  35135. #endif /* SQLITE_ENABLE_LOCKING_STYLE && !OS_VXWORK */

  35136. 

  35137. /******************* End of the flock lock implementation *********************

  35138. ******************************************************************************/

  35139. 

  35140. /******************************************************************************

  35141. ************************ Begin Named Semaphore Locking ************************

  35142. **

  35143. ** Named semaphore locking is only supported on VxWorks.

  35144. **

  35145. ** Semaphore locking is like dot-lock and flock in that it really only

  35146. ** supports EXCLUSIVE locking.  Only a single process can read or write

  35147. ** the database file at a time.  This reduces potential concurrency, but

  35148. ** makes the lock implementation much easier.

  35149. */

  35150. #if OS_VXWORKS

  35151. 

  35152. /*

  35153. ** This routine checks if there is a RESERVED lock held on the specified

  35154. ** file by this or any other process. If such a lock is held, set *pResOut

  35155. ** to a non-zero value otherwise *pResOut is set to zero.  The return value

  35156. ** is set to SQLITE_OK unless an I/O error occurs during lock checking.

  35157. */

  35158. static int semXCheckReservedLock(sqlite3_file *id, int *pResOut) {

  35159.   int rc = SQLITE_OK;

  35160.   int reserved = 0;

  35161.   unixFile *pFile = (unixFile*)id;

  35162. 

  35163.   SimulateIOError( return SQLITE_IOERR_CHECKRESERVEDLOCK; );

  35164.   

  35165.   assert( pFile );

  35166. 

  35167.   /* Check if a thread in this process holds such a lock */

  35168.   if( pFile->eFileLock>SHARED_LOCK ){

  35169.     reserved = 1;

  35170.   }

  35171.   

  35172.   /* Otherwise see if some other process holds it. */

  35173.   if( !reserved ){

  35174.     sem_t *pSem = pFile->pInode->pSem;

  35175. 

  35176.     if( sem_trywait(pSem)==-1 ){

  35177.       int tErrno = errno;

  35178.       if( EAGAIN != tErrno ){

  35179.         rc = sqliteErrorFromPosixError(tErrno, SQLITE_IOERR_CHECKRESERVEDLOCK);

  35180.         storeLastErrno(pFile, tErrno);

  35181.       } else {

  35182.         /* someone else has the lock when we are in NO_LOCK */

  35183.         reserved = (pFile->eFileLock < SHARED_LOCK);

  35184.       }

  35185.     }else{

  35186.       /* we could have it if we want it */

  35187.       sem_post(pSem);

  35188.     }

  35189.   }

  35190.   OSTRACE(("TEST WR-LOCK %d %d %d (sem)\n", pFile->h, rc, reserved));

  35191. 

  35192.   *pResOut = reserved;

  35193.   return rc;

  35194. }

  35195. 

  35196. /*

  35197. ** Lock the file with the lock specified by parameter eFileLock - one

  35198. ** of the following:

  35199. **

  35200. **     (1) SHARED_LOCK

  35201. **     (2) RESERVED_LOCK

  35202. **     (3) PENDING_LOCK

  35203. **     (4) EXCLUSIVE_LOCK

  35204. **

  35205. ** Sometimes when requesting one lock state, additional lock states

  35206. ** are inserted in between.  The locking might fail on one of the later

  35207. ** transitions leaving the lock state different from what it started but

  35208. ** still short of its goal.  The following chart shows the allowed

  35209. ** transitions and the inserted intermediate states:

  35210. **

  35211. **    UNLOCKED -> SHARED

  35212. **    SHARED -> RESERVED

  35213. **    SHARED -> (PENDING) -> EXCLUSIVE

  35214. **    RESERVED -> (PENDING) -> EXCLUSIVE

  35215. **    PENDING -> EXCLUSIVE

  35216. **

  35217. ** Semaphore locks only really support EXCLUSIVE locks.  We track intermediate

  35218. ** lock states in the sqlite3_file structure, but all locks SHARED or

  35219. ** above are really EXCLUSIVE locks and exclude all other processes from

  35220. ** access the file.

  35221. **

  35222. ** This routine will only increase a lock.  Use the sqlite3OsUnlock()

  35223. ** routine to lower a locking level.

  35224. */

  35225. static int semXLock(sqlite3_file *id, int eFileLock) {

  35226.   unixFile *pFile = (unixFile*)id;

  35227.   sem_t *pSem = pFile->pInode->pSem;

  35228.   int rc = SQLITE_OK;

  35229. 

  35230.   /* if we already have a lock, it is exclusive.  

  35231.   ** Just adjust level and punt on outta here. */

  35232.   if (pFile->eFileLock > NO_LOCK) {

  35233.     pFile->eFileLock = eFileLock;

  35234.     rc = SQLITE_OK;

  35235.     goto sem_end_lock;

  35236.   }

  35237.   

  35238.   /* lock semaphore now but bail out when already locked. */

  35239.   if( sem_trywait(pSem)==-1 ){

  35240.     rc = SQLITE_BUSY;

  35241.     goto sem_end_lock;

  35242.   }

  35243. 

  35244.   /* got it, set the type and return ok */

  35245.   pFile->eFileLock = eFileLock;

  35246. 

  35247.  sem_end_lock:

  35248.   return rc;

  35249. }

  35250. 

  35251. /*

  35252. ** Lower the locking level on file descriptor pFile to eFileLock.  eFileLock

  35253. ** must be either NO_LOCK or SHARED_LOCK.

  35254. **

  35255. ** If the locking level of the file descriptor is already at or below

  35256. ** the requested locking level, this routine is a no-op.

  35257. */

  35258. static int semXUnlock(sqlite3_file *id, int eFileLock) {

  35259.   unixFile *pFile = (unixFile*)id;

  35260.   sem_t *pSem = pFile->pInode->pSem;

  35261. 

  35262.   assert( pFile );

  35263.   assert( pSem );

  35264.   OSTRACE(("UNLOCK  %d %d was %d pid=%d (sem)\n", pFile->h, eFileLock,

  35265.            pFile->eFileLock, osGetpid(0)));

  35266.   assert( eFileLock<=SHARED_LOCK );

  35267.   

  35268.   /* no-op if possible */

  35269.   if( pFile->eFileLock==eFileLock ){

  35270.     return SQLITE_OK;

  35271.   }

  35272.   

  35273.   /* shared can just be set because we always have an exclusive */

  35274.   if (eFileLock==SHARED_LOCK) {

  35275.     pFile->eFileLock = eFileLock;

  35276.     return SQLITE_OK;

  35277.   }

  35278.   

  35279.   /* no, really unlock. */

  35280.   if ( sem_post(pSem)==-1 ) {

  35281.     int rc, tErrno = errno;

  35282.     rc = sqliteErrorFromPosixError(tErrno, SQLITE_IOERR_UNLOCK);

  35283.     if( IS_LOCK_ERROR(rc) ){

  35284.       storeLastErrno(pFile, tErrno);

  35285.     }

  35286.     return rc; 

  35287.   }

  35288.   pFile->eFileLock = NO_LOCK;

  35289.   return SQLITE_OK;

  35290. }

  35291. 

  35292. /*

  35293.  ** Close a file.

  35294.  */

  35295. static int semXClose(sqlite3_file *id) {

  35296.   if( id ){

  35297.     unixFile *pFile = (unixFile*)id;

  35298.     semXUnlock(id, NO_LOCK);

  35299.     assert( pFile );

  35300.     assert( unixFileMutexNotheld(pFile) );

  35301.     unixEnterMutex();

  35302.     releaseInodeInfo(pFile);

  35303.     unixLeaveMutex();

  35304.     closeUnixFile(id);

  35305.   }

  35306.   return SQLITE_OK;

  35307. }

  35308. 

  35309. #endif /* OS_VXWORKS */

  35310. /*

  35311. ** Named semaphore locking is only available on VxWorks.

  35312. **

  35313. *************** End of the named semaphore lock implementation ****************

  35314. ******************************************************************************/

  35315. 

  35316. 

  35317. /******************************************************************************

  35318. *************************** Begin AFP Locking *********************************

  35319. **

  35320. ** AFP is the Apple Filing Protocol.  AFP is a network filesystem found

  35321. ** on Apple Macintosh computers - both OS9 and OSX.

  35322. **

  35323. ** Third-party implementations of AFP are available.  But this code here

  35324. ** only works on OSX.

  35325. */

  35326. 

  35327. #if defined(__APPLE__) && SQLITE_ENABLE_LOCKING_STYLE

  35328. /*

  35329. ** The afpLockingContext structure contains all afp lock specific state

  35330. */

  35331. typedef struct afpLockingContext afpLockingContext;

  35332. struct afpLockingContext {

  35333.   int reserved;

  35334.   const char *dbPath;             /* Name of the open file */

  35335. };

  35336. 

  35337. struct ByteRangeLockPB2

  35338. {

  35339.   unsigned long long offset;        /* offset to first byte to lock */

  35340.   unsigned long long length;        /* nbr of bytes to lock */

  35341.   unsigned long long retRangeStart; /* nbr of 1st byte locked if successful */

  35342.   unsigned char unLockFlag;         /* 1 = unlock, 0 = lock */

  35343.   unsigned char startEndFlag;       /* 1=rel to end of fork, 0=rel to start */

  35344.   int fd;                           /* file desc to assoc this lock with */

  35345. };

  35346. 

  35347. #define afpfsByteRangeLock2FSCTL        _IOWR('z', 23, struct ByteRangeLockPB2)

  35348. 

  35349. /*

  35350. ** This is a utility for setting or clearing a bit-range lock on an

  35351. ** AFP filesystem.

  35352. ** 

  35353. ** Return SQLITE_OK on success, SQLITE_BUSY on failure.

  35354. */

  35355. static int afpSetLock(

  35356.   const char *path,              /* Name of the file to be locked or unlocked */

  35357.   unixFile *pFile,               /* Open file descriptor on path */

  35358.   unsigned long long offset,     /* First byte to be locked */

  35359.   unsigned long long length,     /* Number of bytes to lock */

  35360.   int setLockFlag                /* True to set lock.  False to clear lock */

  35361. ){

  35362.   struct ByteRangeLockPB2 pb;

  35363.   int err;

  35364.   

  35365.   pb.unLockFlag = setLockFlag ? 0 : 1;

  35366.   pb.startEndFlag = 0;

  35367.   pb.offset = offset;

  35368.   pb.length = length; 

  35369.   pb.fd = pFile->h;

  35370.   

  35371.   OSTRACE(("AFPSETLOCK [%s] for %d%s in range %llx:%llx\n", 

  35372.     (setLockFlag?"ON":"OFF"), pFile->h, (pb.fd==-1?"[testval-1]":""),

  35373.     offset, length));

  35374.   err = fsctl(path, afpfsByteRangeLock2FSCTL, &pb, 0);

  35375.   if ( err==-1 ) {

  35376.     int rc;

  35377.     int tErrno = errno;

  35378.     OSTRACE(("AFPSETLOCK failed to fsctl() '%s' %d %s\n",

  35379.              path, tErrno, strerror(tErrno)));

  35380. #ifdef SQLITE_IGNORE_AFP_LOCK_ERRORS

  35381.     rc = SQLITE_BUSY;

  35382. #else

  35383.     rc = sqliteErrorFromPosixError(tErrno,

  35384.                     setLockFlag ? SQLITE_IOERR_LOCK : SQLITE_IOERR_UNLOCK);

  35385. #endif /* SQLITE_IGNORE_AFP_LOCK_ERRORS */

  35386.     if( IS_LOCK_ERROR(rc) ){

  35387.       storeLastErrno(pFile, tErrno);

  35388.     }

  35389.     return rc;

  35390.   } else {

  35391.     return SQLITE_OK;

  35392.   }

  35393. }

  35394. 

  35395. /*

  35396. ** This routine checks if there is a RESERVED lock held on the specified

  35397. ** file by this or any other process. If such a lock is held, set *pResOut

  35398. ** to a non-zero value otherwise *pResOut is set to zero.  The return value

  35399. ** is set to SQLITE_OK unless an I/O error occurs during lock checking.

  35400. */

  35401. static int afpCheckReservedLock(sqlite3_file *id, int *pResOut){

  35402.   int rc = SQLITE_OK;

  35403.   int reserved = 0;

  35404.   unixFile *pFile = (unixFile*)id;

  35405.   afpLockingContext *context;

  35406.   

  35407.   SimulateIOError( return SQLITE_IOERR_CHECKRESERVEDLOCK; );

  35408.   

  35409.   assert( pFile );

  35410.   context = (afpLockingContext *) pFile->lockingContext;

  35411.   if( context->reserved ){

  35412.     *pResOut = 1;

  35413.     return SQLITE_OK;

  35414.   }

  35415.   sqlite3_mutex_enter(pFile->pInode->pLockMutex);

  35416.   /* Check if a thread in this process holds such a lock */

  35417.   if( pFile->pInode->eFileLock>SHARED_LOCK ){

  35418.     reserved = 1;

  35419.   }

  35420.   

  35421.   /* Otherwise see if some other process holds it.

  35422.    */

  35423.   if( !reserved ){

  35424.     /* lock the RESERVED byte */

  35425.     int lrc = afpSetLock(context->dbPath, pFile, RESERVED_BYTE, 1,1);  

  35426.     if( SQLITE_OK==lrc ){

  35427.       /* if we succeeded in taking the reserved lock, unlock it to restore

  35428.       ** the original state */

  35429.       lrc = afpSetLock(context->dbPath, pFile, RESERVED_BYTE, 1, 0);

  35430.     } else {

  35431.       /* if we failed to get the lock then someone else must have it */

  35432.       reserved = 1;

  35433.     }

  35434.     if( IS_LOCK_ERROR(lrc) ){

  35435.       rc=lrc;

  35436.     }

  35437.   }

  35438.   

  35439.   sqlite3_mutex_leave(pFile->pInode->pLockMutex);

  35440.   OSTRACE(("TEST WR-LOCK %d %d %d (afp)\n", pFile->h, rc, reserved));

  35441.   

  35442.   *pResOut = reserved;

  35443.   return rc;

  35444. }

  35445. 

  35446. /*

  35447. ** Lock the file with the lock specified by parameter eFileLock - one

  35448. ** of the following:

  35449. **

  35450. **     (1) SHARED_LOCK

  35451. **     (2) RESERVED_LOCK

  35452. **     (3) PENDING_LOCK

  35453. **     (4) EXCLUSIVE_LOCK

  35454. **

  35455. ** Sometimes when requesting one lock state, additional lock states

  35456. ** are inserted in between.  The locking might fail on one of the later

  35457. ** transitions leaving the lock state different from what it started but

  35458. ** still short of its goal.  The following chart shows the allowed

  35459. ** transitions and the inserted intermediate states:

  35460. **

  35461. **    UNLOCKED -> SHARED

  35462. **    SHARED -> RESERVED

  35463. **    SHARED -> (PENDING) -> EXCLUSIVE

  35464. **    RESERVED -> (PENDING) -> EXCLUSIVE

  35465. **    PENDING -> EXCLUSIVE

  35466. **

  35467. ** This routine will only increase a lock.  Use the sqlite3OsUnlock()

  35468. ** routine to lower a locking level.

  35469. */

  35470. static int afpLock(sqlite3_file *id, int eFileLock){

  35471.   int rc = SQLITE_OK;

  35472.   unixFile *pFile = (unixFile*)id;

  35473.   unixInodeInfo *pInode = pFile->pInode;

  35474.   afpLockingContext *context = (afpLockingContext *) pFile->lockingContext;

  35475.   

  35476.   assert( pFile );

  35477.   OSTRACE(("LOCK    %d %s was %s(%s,%d) pid=%d (afp)\n", pFile->h,

  35478.            azFileLock(eFileLock), azFileLock(pFile->eFileLock),

  35479.            azFileLock(pInode->eFileLock), pInode->nShared , osGetpid(0)));

  35480. 

  35481.   /* If there is already a lock of this type or more restrictive on the

  35482.   ** unixFile, do nothing. Don't use the afp_end_lock: exit path, as

  35483.   ** unixEnterMutex() hasn't been called yet.

  35484.   */

  35485.   if( pFile->eFileLock>=eFileLock ){

  35486.     OSTRACE(("LOCK    %d %s ok (already held) (afp)\n", pFile->h,

  35487.            azFileLock(eFileLock)));

  35488.     return SQLITE_OK;

  35489.   }

  35490. 

  35491.   /* Make sure the locking sequence is correct

  35492.   **  (1) We never move from unlocked to anything higher than shared lock.

  35493.   **  (2) SQLite never explicitly requests a pendig lock.

  35494.   **  (3) A shared lock is always held when a reserve lock is requested.

  35495.   */

  35496.   assert( pFile->eFileLock!=NO_LOCK || eFileLock==SHARED_LOCK );

  35497.   assert( eFileLock!=PENDING_LOCK );

  35498.   assert( eFileLock!=RESERVED_LOCK || pFile->eFileLock==SHARED_LOCK );

  35499.   

  35500.   /* This mutex is needed because pFile->pInode is shared across threads

  35501.   */

  35502.   pInode = pFile->pInode;

  35503.   sqlite3_mutex_enter(pInode->pLockMutex);

  35504. 

  35505.   /* If some thread using this PID has a lock via a different unixFile*

  35506.   ** handle that precludes the requested lock, return BUSY.

  35507.   */

  35508.   if( (pFile->eFileLock!=pInode->eFileLock && 

  35509.        (pInode->eFileLock>=PENDING_LOCK || eFileLock>SHARED_LOCK))

  35510.      ){

  35511.     rc = SQLITE_BUSY;

  35512.     goto afp_end_lock;

  35513.   }

  35514.   

  35515.   /* If a SHARED lock is requested, and some thread using this PID already

  35516.   ** has a SHARED or RESERVED lock, then increment reference counts and

  35517.   ** return SQLITE_OK.

  35518.   */

  35519.   if( eFileLock==SHARED_LOCK && 

  35520.      (pInode->eFileLock==SHARED_LOCK || pInode->eFileLock==RESERVED_LOCK) ){

  35521.     assert( eFileLock==SHARED_LOCK );

  35522.     assert( pFile->eFileLock==0 );

  35523.     assert( pInode->nShared>0 );

  35524.     pFile->eFileLock = SHARED_LOCK;

  35525.     pInode->nShared++;

  35526.     pInode->nLock++;

  35527.     goto afp_end_lock;

  35528.   }

  35529.     

  35530.   /* A PENDING lock is needed before acquiring a SHARED lock and before

  35531.   ** acquiring an EXCLUSIVE lock.  For the SHARED lock, the PENDING will

  35532.   ** be released.

  35533.   */

  35534.   if( eFileLock==SHARED_LOCK 

  35535.       || (eFileLock==EXCLUSIVE_LOCK && pFile->eFileLock<PENDING_LOCK)

  35536.   ){

  35537.     int failed;

  35538.     failed = afpSetLock(context->dbPath, pFile, PENDING_BYTE, 1, 1);

  35539.     if (failed) {

  35540.       rc = failed;

  35541.       goto afp_end_lock;

  35542.     }

  35543.   }

  35544.   

  35545.   /* If control gets to this point, then actually go ahead and make

  35546.   ** operating system calls for the specified lock.

  35547.   */

  35548.   if( eFileLock==SHARED_LOCK ){

  35549.     int lrc1, lrc2, lrc1Errno = 0;

  35550.     long lk, mask;

  35551.     

  35552.     assert( pInode->nShared==0 );

  35553.     assert( pInode->eFileLock==0 );

  35554.         

  35555.     mask = (sizeof(long)==8) ? LARGEST_INT64 : 0x7fffffff;

  35556.     /* Now get the read-lock SHARED_LOCK */

  35557.     /* note that the quality of the randomness doesn't matter that much */

  35558.     lk = random(); 

  35559.     pInode->sharedByte = (lk & mask)%(SHARED_SIZE - 1);

  35560.     lrc1 = afpSetLock(context->dbPath, pFile, 

  35561.           SHARED_FIRST+pInode->sharedByte, 1, 1);

  35562.     if( IS_LOCK_ERROR(lrc1) ){

  35563.       lrc1Errno = pFile->lastErrno;

  35564.     }

  35565.     /* Drop the temporary PENDING lock */

  35566.     lrc2 = afpSetLock(context->dbPath, pFile, PENDING_BYTE, 1, 0);

  35567.     

  35568.     if( IS_LOCK_ERROR(lrc1) ) {

  35569.       storeLastErrno(pFile, lrc1Errno);

  35570.       rc = lrc1;

  35571.       goto afp_end_lock;

  35572.     } else if( IS_LOCK_ERROR(lrc2) ){

  35573.       rc = lrc2;

  35574.       goto afp_end_lock;

  35575.     } else if( lrc1 != SQLITE_OK ) {

  35576.       rc = lrc1;

  35577.     } else {

  35578.       pFile->eFileLock = SHARED_LOCK;

  35579.       pInode->nLock++;

  35580.       pInode->nShared = 1;

  35581.     }

  35582.   }else if( eFileLock==EXCLUSIVE_LOCK && pInode->nShared>1 ){

  35583.     /* We are trying for an exclusive lock but another thread in this

  35584.      ** same process is still holding a shared lock. */

  35585.     rc = SQLITE_BUSY;

  35586.   }else{

  35587.     /* The request was for a RESERVED or EXCLUSIVE lock.  It is

  35588.     ** assumed that there is a SHARED or greater lock on the file

  35589.     ** already.

  35590.     */

  35591.     int failed = 0;

  35592.     assert( 0!=pFile->eFileLock );

  35593.     if (eFileLock >= RESERVED_LOCK && pFile->eFileLock < RESERVED_LOCK) {

  35594.         /* Acquire a RESERVED lock */

  35595.         failed = afpSetLock(context->dbPath, pFile, RESERVED_BYTE, 1,1);

  35596.       if( !failed ){

  35597.         context->reserved = 1;

  35598.       }

  35599.     }

  35600.     if (!failed && eFileLock == EXCLUSIVE_LOCK) {

  35601.       /* Acquire an EXCLUSIVE lock */

  35602.         

  35603.       /* Remove the shared lock before trying the range.  we'll need to 

  35604.       ** reestablish the shared lock if we can't get the  afpUnlock

  35605.       */

  35606.       if( !(failed = afpSetLock(context->dbPath, pFile, SHARED_FIRST +

  35607.                          pInode->sharedByte, 1, 0)) ){

  35608.         int failed2 = SQLITE_OK;

  35609.         /* now attemmpt to get the exclusive lock range */

  35610.         failed = afpSetLock(context->dbPath, pFile, SHARED_FIRST, 

  35611.                                SHARED_SIZE, 1);

  35612.         if( failed && (failed2 = afpSetLock(context->dbPath, pFile, 

  35613.                        SHARED_FIRST + pInode->sharedByte, 1, 1)) ){

  35614.           /* Can't reestablish the shared lock.  Sqlite can't deal, this is

  35615.           ** a critical I/O error

  35616.           */

  35617.           rc = ((failed & 0xff) == SQLITE_IOERR) ? failed2 : 

  35618.                SQLITE_IOERR_LOCK;

  35619.           goto afp_end_lock;

  35620.         } 

  35621.       }else{

  35622.         rc = failed; 

  35623.       }

  35624.     }

  35625.     if( failed ){

  35626.       rc = failed;

  35627.     }

  35628.   }

  35629.   

  35630.   if( rc==SQLITE_OK ){

  35631.     pFile->eFileLock = eFileLock;

  35632.     pInode->eFileLock = eFileLock;

  35633.   }else if( eFileLock==EXCLUSIVE_LOCK ){

  35634.     pFile->eFileLock = PENDING_LOCK;

  35635.     pInode->eFileLock = PENDING_LOCK;

  35636.   }

  35637.   

  35638. afp_end_lock:

  35639.   sqlite3_mutex_leave(pInode->pLockMutex);

  35640.   OSTRACE(("LOCK    %d %s %s (afp)\n", pFile->h, azFileLock(eFileLock), 

  35641.          rc==SQLITE_OK ? "ok" : "failed"));

  35642.   return rc;

  35643. }

  35644. 

  35645. /*

  35646. ** Lower the locking level on file descriptor pFile to eFileLock.  eFileLock

  35647. ** must be either NO_LOCK or SHARED_LOCK.

  35648. **

  35649. ** If the locking level of the file descriptor is already at or below

  35650. ** the requested locking level, this routine is a no-op.

  35651. */

  35652. static int afpUnlock(sqlite3_file *id, int eFileLock) {

  35653.   int rc = SQLITE_OK;

  35654.   unixFile *pFile = (unixFile*)id;

  35655.   unixInodeInfo *pInode;

  35656.   afpLockingContext *context = (afpLockingContext *) pFile->lockingContext;

  35657.   int skipShared = 0;

  35658. #ifdef SQLITE_TEST

  35659.   int h = pFile->h;

  35660. #endif

  35661. 

  35662.   assert( pFile );

  35663.   OSTRACE(("UNLOCK  %d %d was %d(%d,%d) pid=%d (afp)\n", pFile->h, eFileLock,

  35664.            pFile->eFileLock, pFile->pInode->eFileLock, pFile->pInode->nShared,

  35665.            osGetpid(0)));

  35666. 

  35667.   assert( eFileLock<=SHARED_LOCK );

  35668.   if( pFile->eFileLock<=eFileLock ){

  35669.     return SQLITE_OK;

  35670.   }

  35671.   pInode = pFile->pInode;

  35672.   sqlite3_mutex_enter(pInode->pLockMutex);

  35673.   assert( pInode->nShared!=0 );

  35674.   if( pFile->eFileLock>SHARED_LOCK ){

  35675.     assert( pInode->eFileLock==pFile->eFileLock );

  35676.     SimulateIOErrorBenign(1);

  35677.     SimulateIOError( h=(-1) )

  35678.     SimulateIOErrorBenign(0);

  35679.     

  35680. #ifdef SQLITE_DEBUG

  35681.     /* When reducing a lock such that other processes can start

  35682.     ** reading the database file again, make sure that the

  35683.     ** transaction counter was updated if any part of the database

  35684.     ** file changed.  If the transaction counter is not updated,

  35685.     ** other connections to the same file might not realize that

  35686.     ** the file has changed and hence might not know to flush their

  35687.     ** cache.  The use of a stale cache can lead to database corruption.

  35688.     */

  35689.     assert( pFile->inNormalWrite==0

  35690.            || pFile->dbUpdate==0

  35691.            || pFile->transCntrChng==1 );

  35692.     pFile->inNormalWrite = 0;

  35693. #endif

  35694.     

  35695.     if( pFile->eFileLock==EXCLUSIVE_LOCK ){

  35696.       rc = afpSetLock(context->dbPath, pFile, SHARED_FIRST, SHARED_SIZE, 0);

  35697.       if( rc==SQLITE_OK && (eFileLock==SHARED_LOCK || pInode->nShared>1) ){

  35698.         /* only re-establish the shared lock if necessary */

  35699.         int sharedLockByte = SHARED_FIRST+pInode->sharedByte;

  35700.         rc = afpSetLock(context->dbPath, pFile, sharedLockByte, 1, 1);

  35701.       } else {

  35702.         skipShared = 1;

  35703.       }

  35704.     }

  35705.     if( rc==SQLITE_OK && pFile->eFileLock>=PENDING_LOCK ){

  35706.       rc = afpSetLock(context->dbPath, pFile, PENDING_BYTE, 1, 0);

  35707.     } 

  35708.     if( rc==SQLITE_OK && pFile->eFileLock>=RESERVED_LOCK && context->reserved ){

  35709.       rc = afpSetLock(context->dbPath, pFile, RESERVED_BYTE, 1, 0);

  35710.       if( !rc ){ 

  35711.         context->reserved = 0; 

  35712.       }

  35713.     }

  35714.     if( rc==SQLITE_OK && (eFileLock==SHARED_LOCK || pInode->nShared>1)){

  35715.       pInode->eFileLock = SHARED_LOCK;

  35716.     }

  35717.   }

  35718.   if( rc==SQLITE_OK && eFileLock==NO_LOCK ){

  35719. 

  35720.     /* Decrement the shared lock counter.  Release the lock using an

  35721.     ** OS call only when all threads in this same process have released

  35722.     ** the lock.

  35723.     */

  35724.     unsigned long long sharedLockByte = SHARED_FIRST+pInode->sharedByte;

  35725.     pInode->nShared--;

  35726.     if( pInode->nShared==0 ){

  35727.       SimulateIOErrorBenign(1);

  35728.       SimulateIOError( h=(-1) )

  35729.       SimulateIOErrorBenign(0);

  35730.       if( !skipShared ){

  35731.         rc = afpSetLock(context->dbPath, pFile, sharedLockByte, 1, 0);

  35732.       }

  35733.       if( !rc ){

  35734.         pInode->eFileLock = NO_LOCK;

  35735.         pFile->eFileLock = NO_LOCK;

  35736.       }

  35737.     }

  35738.     if( rc==SQLITE_OK ){

  35739.       pInode->nLock--;

  35740.       assert( pInode->nLock>=0 );

  35741.       if( pInode->nLock==0 ) closePendingFds(pFile);

  35742.     }

  35743.   }

  35744.   

  35745.   sqlite3_mutex_leave(pInode->pLockMutex);

  35746.   if( rc==SQLITE_OK ){

  35747.     pFile->eFileLock = eFileLock;

  35748.   }

  35749.   return rc;

  35750. }

  35751. 

  35752. /*

  35753. ** Close a file & cleanup AFP specific locking context 

  35754. */

  35755. static int afpClose(sqlite3_file *id) {

  35756.   int rc = SQLITE_OK;

  35757.   unixFile *pFile = (unixFile*)id;

  35758.   assert( id!=0 );

  35759.   afpUnlock(id, NO_LOCK);

  35760.   assert( unixFileMutexNotheld(pFile) );

  35761.   unixEnterMutex();

  35762.   if( pFile->pInode ){

  35763.     unixInodeInfo *pInode = pFile->pInode;

  35764.     sqlite3_mutex_enter(pInode->pLockMutex);

  35765.     if( pInode->nLock ){

  35766.       /* If there are outstanding locks, do not actually close the file just

  35767.       ** yet because that would clear those locks.  Instead, add the file

  35768.       ** descriptor to pInode->aPending.  It will be automatically closed when

  35769.       ** the last lock is cleared.

  35770.       */

  35771.       setPendingFd(pFile);

  35772.     }

  35773.     sqlite3_mutex_leave(pInode->pLockMutex);

  35774.   }

  35775.   releaseInodeInfo(pFile);

  35776.   sqlite3_free(pFile->lockingContext);

  35777.   rc = closeUnixFile(id);

  35778.   unixLeaveMutex();

  35779.   return rc;

  35780. }

  35781. 

  35782. #endif /* defined(__APPLE__) && SQLITE_ENABLE_LOCKING_STYLE */

  35783. /*

  35784. ** The code above is the AFP lock implementation.  The code is specific

  35785. ** to MacOSX and does not work on other unix platforms.  No alternative

  35786. ** is available.  If you don't compile for a mac, then the "unix-afp"

  35787. ** VFS is not available.

  35788. **

  35789. ********************* End of the AFP lock implementation **********************

  35790. ******************************************************************************/

  35791. 

  35792. /******************************************************************************

  35793. *************************** Begin NFS Locking ********************************/

  35794. 

  35795. #if defined(__APPLE__) && SQLITE_ENABLE_LOCKING_STYLE

  35796. /*

  35797.  ** Lower the locking level on file descriptor pFile to eFileLock.  eFileLock

  35798.  ** must be either NO_LOCK or SHARED_LOCK.

  35799.  **

  35800.  ** If the locking level of the file descriptor is already at or below

  35801.  ** the requested locking level, this routine is a no-op.

  35802.  */

  35803. static int nfsUnlock(sqlite3_file *id, int eFileLock){

  35804.   return posixUnlock(id, eFileLock, 1);

  35805. }

  35806. 

  35807. #endif /* defined(__APPLE__) && SQLITE_ENABLE_LOCKING_STYLE */

  35808. /*

  35809. ** The code above is the NFS lock implementation.  The code is specific

  35810. ** to MacOSX and does not work on other unix platforms.  No alternative

  35811. ** is available.  

  35812. **

  35813. ********************* End of the NFS lock implementation **********************

  35814. ******************************************************************************/

  35815. 

  35816. /******************************************************************************

  35817. **************** Non-locking sqlite3_file methods *****************************

  35818. **

  35819. ** The next division contains implementations for all methods of the 

  35820. ** sqlite3_file object other than the locking methods.  The locking

  35821. ** methods were defined in divisions above (one locking method per

  35822. ** division).  Those methods that are common to all locking modes

  35823. ** are gather together into this division.

  35824. */

  35825. 

  35826. /*

  35827. ** Seek to the offset passed as the second argument, then read cnt 

  35828. ** bytes into pBuf. Return the number of bytes actually read.

  35829. **

  35830. ** NB:  If you define USE_PREAD or USE_PREAD64, then it might also

  35831. ** be necessary to define _XOPEN_SOURCE to be 500.  This varies from

  35832. ** one system to another.  Since SQLite does not define USE_PREAD

  35833. ** in any form by default, we will not attempt to define _XOPEN_SOURCE.

  35834. ** See tickets #2741 and #2681.

  35835. **

  35836. ** To avoid stomping the errno value on a failed read the lastErrno value

  35837. ** is set before returning.

  35838. */

  35839. static int seekAndRead(unixFile *id, sqlite3_int64 offset, void *pBuf, int cnt){

  35840.   int got;

  35841.   int prior = 0;

  35842. #if (!defined(USE_PREAD) && !defined(USE_PREAD64))

  35843.   i64 newOffset;

  35844. #endif

  35845.   TIMER_START;

  35846.   assert( cnt==(cnt&0x1ffff) );

  35847.   assert( id->h>2 );

  35848.   do{

  35849. #if defined(USE_PREAD)

  35850.     got = osPread(id->h, pBuf, cnt, offset);

  35851.     SimulateIOError( got = -1 );

  35852. #elif defined(USE_PREAD64)

  35853.     got = osPread64(id->h, pBuf, cnt, offset);

  35854.     SimulateIOError( got = -1 );

  35855. #else

  35856.     newOffset = lseek(id->h, offset, SEEK_SET);

  35857.     SimulateIOError( newOffset = -1 );

  35858.     if( newOffset<0 ){

  35859.       storeLastErrno((unixFile*)id, errno);

  35860.       return -1;

  35861.     }

  35862.     got = osRead(id->h, pBuf, cnt);

  35863. #endif

  35864.     if( got==cnt ) break;

  35865.     if( got<0 ){

  35866.       if( errno==EINTR ){ got = 1; continue; }

  35867.       prior = 0;

  35868.       storeLastErrno((unixFile*)id,  errno);

  35869.       break;

  35870.     }else if( got>0 ){

  35871.       cnt -= got;

  35872.       offset += got;

  35873.       prior += got;

  35874.       pBuf = (void*)(got + (char*)pBuf);

  35875.     }

  35876.   }while( got>0 );

  35877.   TIMER_END;

  35878.   OSTRACE(("READ    %-3d %5d %7lld %llu\n",

  35879.             id->h, got+prior, offset-prior, TIMER_ELAPSED));

  35880.   return got+prior;

  35881. }

  35882. 

  35883. /*

  35884. ** Read data from a file into a buffer.  Return SQLITE_OK if all

  35885. ** bytes were read successfully and SQLITE_IOERR if anything goes

  35886. ** wrong.

  35887. */

  35888. static int unixRead(

  35889.   sqlite3_file *id, 

  35890.   void *pBuf, 

  35891.   int amt,

  35892.   sqlite3_int64 offset

  35893. ){

  35894.   unixFile *pFile = (unixFile *)id;

  35895.   int got;

  35896.   assert( id );

  35897.   assert( offset>=0 );

  35898.   assert( amt>0 );

  35899. 

  35900.   /* If this is a database file (not a journal, master-journal or temp

  35901.   ** file), the bytes in the locking range should never be read or written. */

  35902. #if 0

  35903.   assert( pFile->pPreallocatedUnused==0

  35904.        || offset>=PENDING_BYTE+512

  35905.        || offset+amt<=PENDING_BYTE 

  35906.   );

  35907. #endif

  35908. 

  35909. #if SQLITE_MAX_MMAP_SIZE>0

  35910.   /* Deal with as much of this read request as possible by transfering

  35911.   ** data from the memory mapping using memcpy().  */

  35912.   if( offset<pFile->mmapSize ){

  35913.     if( offset+amt <= pFile->mmapSize ){

  35914.       memcpy(pBuf, &((u8 *)(pFile->pMapRegion))[offset], amt);

  35915.       return SQLITE_OK;

  35916.     }else{

  35917.       int nCopy = pFile->mmapSize - offset;

  35918.       memcpy(pBuf, &((u8 *)(pFile->pMapRegion))[offset], nCopy);

  35919.       pBuf = &((u8 *)pBuf)[nCopy];

  35920.       amt -= nCopy;

  35921.       offset += nCopy;

  35922.     }

  35923.   }

  35924. #endif

  35925. 

  35926.   got = seekAndRead(pFile, offset, pBuf, amt);

  35927.   if( got==amt ){

  35928.     return SQLITE_OK;

  35929.   }else if( got<0 ){

  35930.     /* lastErrno set by seekAndRead */

  35931.     return SQLITE_IOERR_READ;

  35932.   }else{

  35933.     storeLastErrno(pFile, 0);   /* not a system error */

  35934.     /* Unread parts of the buffer must be zero-filled */

  35935.     memset(&((char*)pBuf)[got], 0, amt-got);

  35936.     return SQLITE_IOERR_SHORT_READ;

  35937.   }

  35938. }

  35939. 

  35940. /*

  35941. ** Attempt to seek the file-descriptor passed as the first argument to

  35942. ** absolute offset iOff, then attempt to write nBuf bytes of data from

  35943. ** pBuf to it. If an error occurs, return -1 and set *piErrno. Otherwise, 

  35944. ** return the actual number of bytes written (which may be less than

  35945. ** nBuf).

  35946. */

  35947. static int seekAndWriteFd(

  35948.   int fd,                         /* File descriptor to write to */

  35949.   i64 iOff,                       /* File offset to begin writing at */

  35950.   const void *pBuf,               /* Copy data from this buffer to the file */

  35951.   int nBuf,                       /* Size of buffer pBuf in bytes */

  35952.   int *piErrno                    /* OUT: Error number if error occurs */

  35953. ){

  35954.   int rc = 0;                     /* Value returned by system call */

  35955. 

  35956.   assert( nBuf==(nBuf&0x1ffff) );

  35957.   assert( fd>2 );

  35958.   assert( piErrno!=0 );

  35959.   nBuf &= 0x1ffff;

  35960.   TIMER_START;

  35961. 

  35962. #if defined(USE_PREAD)

  35963.   do{ rc = (int)osPwrite(fd, pBuf, nBuf, iOff); }while( rc<0 && errno==EINTR );

  35964. #elif defined(USE_PREAD64)

  35965.   do{ rc = (int)osPwrite64(fd, pBuf, nBuf, iOff);}while( rc<0 && errno==EINTR);

  35966. #else

  35967.   do{

  35968.     i64 iSeek = lseek(fd, iOff, SEEK_SET);

  35969.     SimulateIOError( iSeek = -1 );

  35970.     if( iSeek<0 ){

  35971.       rc = -1;

  35972.       break;

  35973.     }

  35974.     rc = osWrite(fd, pBuf, nBuf);

  35975.   }while( rc<0 && errno==EINTR );

  35976. #endif

  35977. 

  35978.   TIMER_END;

  35979.   OSTRACE(("WRITE   %-3d %5d %7lld %llu\n", fd, rc, iOff, TIMER_ELAPSED));

  35980. 

  35981.   if( rc<0 ) *piErrno = errno;

  35982.   return rc;

  35983. }

  35984. 

  35985. 

  35986. /*

  35987. ** Seek to the offset in id->offset then read cnt bytes into pBuf.

  35988. ** Return the number of bytes actually read.  Update the offset.

  35989. **

  35990. ** To avoid stomping the errno value on a failed write the lastErrno value

  35991. ** is set before returning.

  35992. */

  35993. static int seekAndWrite(unixFile *id, i64 offset, const void *pBuf, int cnt){

  35994.   return seekAndWriteFd(id->h, offset, pBuf, cnt, &id->lastErrno);

  35995. }

  35996. 

  35997. 

  35998. /*

  35999. ** Write data from a buffer into a file.  Return SQLITE_OK on success

  36000. ** or some other error code on failure.

  36001. */

  36002. static int unixWrite(

  36003.   sqlite3_file *id, 

  36004.   const void *pBuf, 

  36005.   int amt,

  36006.   sqlite3_int64 offset 

  36007. ){

  36008.   unixFile *pFile = (unixFile*)id;

  36009.   int wrote = 0;

  36010.   assert( id );

  36011.   assert( amt>0 );

  36012. 

  36013.   /* If this is a database file (not a journal, master-journal or temp

  36014.   ** file), the bytes in the locking range should never be read or written. */

  36015. #if 0

  36016.   assert( pFile->pPreallocatedUnused==0

  36017.        || offset>=PENDING_BYTE+512

  36018.        || offset+amt<=PENDING_BYTE 

  36019.   );

  36020. #endif

  36021. 

  36022. #ifdef SQLITE_DEBUG

  36023.   /* If we are doing a normal write to a database file (as opposed to

  36024.   ** doing a hot-journal rollback or a write to some file other than a

  36025.   ** normal database file) then record the fact that the database

  36026.   ** has changed.  If the transaction counter is modified, record that

  36027.   ** fact too.

  36028.   */

  36029.   if( pFile->inNormalWrite ){

  36030.     pFile->dbUpdate = 1;  /* The database has been modified */

  36031.     if( offset<=24 && offset+amt>=27 ){

  36032.       int rc;

  36033.       char oldCntr[4];

  36034.       SimulateIOErrorBenign(1);

  36035.       rc = seekAndRead(pFile, 24, oldCntr, 4);

  36036.       SimulateIOErrorBenign(0);

  36037.       if( rc!=4 || memcmp(oldCntr, &((char*)pBuf)[24-offset], 4)!=0 ){

  36038.         pFile->transCntrChng = 1;  /* The transaction counter has changed */

  36039.       }

  36040.     }

  36041.   }

  36042. #endif

  36043. 

  36044. #if defined(SQLITE_MMAP_READWRITE) && SQLITE_MAX_MMAP_SIZE>0

  36045.   /* Deal with as much of this write request as possible by transfering

  36046.   ** data from the memory mapping using memcpy().  */

  36047.   if( offset<pFile->mmapSize ){

  36048.     if( offset+amt <= pFile->mmapSize ){

  36049.       memcpy(&((u8 *)(pFile->pMapRegion))[offset], pBuf, amt);

  36050.       return SQLITE_OK;

  36051.     }else{

  36052.       int nCopy = pFile->mmapSize - offset;

  36053.       memcpy(&((u8 *)(pFile->pMapRegion))[offset], pBuf, nCopy);

  36054.       pBuf = &((u8 *)pBuf)[nCopy];

  36055.       amt -= nCopy;

  36056.       offset += nCopy;

  36057.     }

  36058.   }

  36059. #endif

  36060.  

  36061.   while( (wrote = seekAndWrite(pFile, offset, pBuf, amt))<amt && wrote>0 ){

  36062.     amt -= wrote;

  36063.     offset += wrote;

  36064.     pBuf = &((char*)pBuf)[wrote];

  36065.   }

  36066.   SimulateIOError(( wrote=(-1), amt=1 ));

  36067.   SimulateDiskfullError(( wrote=0, amt=1 ));

  36068. 

  36069.   if( amt>wrote ){

  36070.     if( wrote<0 && pFile->lastErrno!=ENOSPC ){

  36071.       /* lastErrno set by seekAndWrite */

  36072.       return SQLITE_IOERR_WRITE;

  36073.     }else{

  36074.       storeLastErrno(pFile, 0); /* not a system error */

  36075.       return SQLITE_FULL;

  36076.     }

  36077.   }

  36078. 

  36079.   return SQLITE_OK;

  36080. }

  36081. 

  36082. #ifdef SQLITE_TEST

  36083. /*

  36084. ** Count the number of fullsyncs and normal syncs.  This is used to test

  36085. ** that syncs and fullsyncs are occurring at the right times.

  36086. */

  36087. SQLITE_API int sqlite3_sync_count = 0;

  36088. SQLITE_API int sqlite3_fullsync_count = 0;

  36089. #endif

  36090. 

  36091. /*

  36092. ** We do not trust systems to provide a working fdatasync().  Some do.

  36093. ** Others do no.  To be safe, we will stick with the (slightly slower)

  36094. ** fsync(). If you know that your system does support fdatasync() correctly,

  36095. ** then simply compile with -Dfdatasync=fdatasync or -DHAVE_FDATASYNC

  36096. */

  36097. #if !defined(fdatasync) && !HAVE_FDATASYNC

  36098. # define fdatasync fsync

  36099. #endif

  36100. 

  36101. /*

  36102. ** Define HAVE_FULLFSYNC to 0 or 1 depending on whether or not

  36103. ** the F_FULLFSYNC macro is defined.  F_FULLFSYNC is currently

  36104. ** only available on Mac OS X.  But that could change.

  36105. */

  36106. #ifdef F_FULLFSYNC

  36107. # define HAVE_FULLFSYNC 1

  36108. #else

  36109. # define HAVE_FULLFSYNC 0

  36110. #endif

  36111. 

  36112. 

  36113. /*

  36114. ** The fsync() system call does not work as advertised on many

  36115. ** unix systems.  The following procedure is an attempt to make

  36116. ** it work better.

  36117. **

  36118. ** The SQLITE_NO_SYNC macro disables all fsync()s.  This is useful

  36119. ** for testing when we want to run through the test suite quickly.

  36120. ** You are strongly advised *not* to deploy with SQLITE_NO_SYNC

  36121. ** enabled, however, since with SQLITE_NO_SYNC enabled, an OS crash

  36122. ** or power failure will likely corrupt the database file.

  36123. **

  36124. ** SQLite sets the dataOnly flag if the size of the file is unchanged.

  36125. ** The idea behind dataOnly is that it should only write the file content

  36126. ** to disk, not the inode.  We only set dataOnly if the file size is 

  36127. ** unchanged since the file size is part of the inode.  However, 

  36128. ** Ted Ts'o tells us that fdatasync() will also write the inode if the

  36129. ** file size has changed.  The only real difference between fdatasync()

  36130. ** and fsync(), Ted tells us, is that fdatasync() will not flush the

  36131. ** inode if the mtime or owner or other inode attributes have changed.

  36132. ** We only care about the file size, not the other file attributes, so

  36133. ** as far as SQLite is concerned, an fdatasync() is always adequate.

  36134. ** So, we always use fdatasync() if it is available, regardless of

  36135. ** the value of the dataOnly flag.

  36136. */

  36137. static int full_fsync(int fd, int fullSync, int dataOnly){

  36138.   int rc;

  36139. 

  36140.   /* The following "ifdef/elif/else/" block has the same structure as

  36141.   ** the one below. It is replicated here solely to avoid cluttering 

  36142.   ** up the real code with the UNUSED_PARAMETER() macros.

  36143.   */

  36144. #ifdef SQLITE_NO_SYNC

  36145.   UNUSED_PARAMETER(fd);

  36146.   UNUSED_PARAMETER(fullSync);

  36147.   UNUSED_PARAMETER(dataOnly);

  36148. #elif HAVE_FULLFSYNC

  36149.   UNUSED_PARAMETER(dataOnly);

  36150. #else

  36151.   UNUSED_PARAMETER(fullSync);

  36152.   UNUSED_PARAMETER(dataOnly);

  36153. #endif

  36154. 

  36155.   /* Record the number of times that we do a normal fsync() and 

  36156.   ** FULLSYNC.  This is used during testing to verify that this procedure

  36157.   ** gets called with the correct arguments.

  36158.   */

  36159. #ifdef SQLITE_TEST

  36160.   if( fullSync ) sqlite3_fullsync_count++;

  36161.   sqlite3_sync_count++;

  36162. #endif

  36163. 

  36164.   /* If we compiled with the SQLITE_NO_SYNC flag, then syncing is a

  36165.   ** no-op.  But go ahead and call fstat() to validate the file

  36166.   ** descriptor as we need a method to provoke a failure during

  36167.   ** coverate testing.

  36168.   */

  36169. #ifdef SQLITE_NO_SYNC

  36170.   {

  36171.     struct stat buf;

  36172.     rc = osFstat(fd, &buf);

  36173.   }

  36174. #elif HAVE_FULLFSYNC

  36175.   if( fullSync ){

  36176.     rc = osFcntl(fd, F_FULLFSYNC, 0);

  36177.   }else{

  36178.     rc = 1;

  36179.   }

  36180.   /* If the FULLFSYNC failed, fall back to attempting an fsync().

  36181.   ** It shouldn't be possible for fullfsync to fail on the local 

  36182.   ** file system (on OSX), so failure indicates that FULLFSYNC

  36183.   ** isn't supported for this file system. So, attempt an fsync 

  36184.   ** and (for now) ignore the overhead of a superfluous fcntl call.  

  36185.   ** It'd be better to detect fullfsync support once and avoid 

  36186.   ** the fcntl call every time sync is called.

  36187.   */

  36188.   if( rc ) rc = fsync(fd);

  36189. 

  36190. #elif defined(__APPLE__)

  36191.   /* fdatasync() on HFS+ doesn't yet flush the file size if it changed correctly

  36192.   ** so currently we default to the macro that redefines fdatasync to fsync

  36193.   */

  36194.   rc = fsync(fd);

  36195. #else 

  36196.   rc = fdatasync(fd);

  36197. #if OS_VXWORKS

  36198.   if( rc==-1 && errno==ENOTSUP ){

  36199.     rc = fsync(fd);

  36200.   }

  36201. #endif /* OS_VXWORKS */

  36202. #endif /* ifdef SQLITE_NO_SYNC elif HAVE_FULLFSYNC */

  36203. 

  36204.   if( OS_VXWORKS && rc!= -1 ){

  36205.     rc = 0;

  36206.   }

  36207.   return rc;

  36208. }

  36209. 

  36210. /*

  36211. ** Open a file descriptor to the directory containing file zFilename.

  36212. ** If successful, *pFd is set to the opened file descriptor and

  36213. ** SQLITE_OK is returned. If an error occurs, either SQLITE_NOMEM

  36214. ** or SQLITE_CANTOPEN is returned and *pFd is set to an undefined

  36215. ** value.

  36216. **

  36217. ** The directory file descriptor is used for only one thing - to

  36218. ** fsync() a directory to make sure file creation and deletion events

  36219. ** are flushed to disk.  Such fsyncs are not needed on newer

  36220. ** journaling filesystems, but are required on older filesystems.

  36221. **

  36222. ** This routine can be overridden using the xSetSysCall interface.

  36223. ** The ability to override this routine was added in support of the

  36224. ** chromium sandbox.  Opening a directory is a security risk (we are

  36225. ** told) so making it overrideable allows the chromium sandbox to

  36226. ** replace this routine with a harmless no-op.  To make this routine

  36227. ** a no-op, replace it with a stub that returns SQLITE_OK but leaves

  36228. ** *pFd set to a negative number.

  36229. **

  36230. ** If SQLITE_OK is returned, the caller is responsible for closing

  36231. ** the file descriptor *pFd using close().

  36232. */

  36233. static int openDirectory(const char *zFilename, int *pFd){

  36234.   int ii;

  36235.   int fd = -1;

  36236.   char zDirname[MAX_PATHNAME+1];

  36237. 

  36238.   sqlite3_snprintf(MAX_PATHNAME, zDirname, "%s", zFilename);

  36239.   for(ii=(int)strlen(zDirname); ii>0 && zDirname[ii]!='/'; ii--);

  36240.   if( ii>0 ){

  36241.     zDirname[ii] = '\0';

  36242.   }else{

  36243.     if( zDirname[0]!='/' ) zDirname[0] = '.';

  36244.     zDirname[1] = 0;

  36245.   }

  36246.   fd = robust_open(zDirname, O_RDONLY|O_BINARY, 0);

  36247.   if( fd>=0 ){

  36248.     OSTRACE(("OPENDIR %-3d %s\n", fd, zDirname));

  36249.   }

  36250.   *pFd = fd;

  36251.   if( fd>=0 ) return SQLITE_OK;

  36252.   return unixLogError(SQLITE_CANTOPEN_BKPT, "openDirectory", zDirname);

  36253. }

  36254. 

  36255. /*

  36256. ** Make sure all writes to a particular file are committed to disk.

  36257. **

  36258. ** If dataOnly==0 then both the file itself and its metadata (file

  36259. ** size, access time, etc) are synced.  If dataOnly!=0 then only the

  36260. ** file data is synced.

  36261. **

  36262. ** Under Unix, also make sure that the directory entry for the file

  36263. ** has been created by fsync-ing the directory that contains the file.

  36264. ** If we do not do this and we encounter a power failure, the directory

  36265. ** entry for the journal might not exist after we reboot.  The next

  36266. ** SQLite to access the file will not know that the journal exists (because

  36267. ** the directory entry for the journal was never created) and the transaction

  36268. ** will not roll back - possibly leading to database corruption.

  36269. */

  36270. static int unixSync(sqlite3_file *id, int flags){

  36271.   int rc;

  36272.   unixFile *pFile = (unixFile*)id;

  36273. 

  36274.   int isDataOnly = (flags&SQLITE_SYNC_DATAONLY);

  36275.   int isFullsync = (flags&0x0F)==SQLITE_SYNC_FULL;

  36276. 

  36277.   /* Check that one of SQLITE_SYNC_NORMAL or FULL was passed */

  36278.   assert((flags&0x0F)==SQLITE_SYNC_NORMAL

  36279.       || (flags&0x0F)==SQLITE_SYNC_FULL

  36280.   );

  36281. 

  36282.   /* Unix cannot, but some systems may return SQLITE_FULL from here. This

  36283.   ** line is to test that doing so does not cause any problems.

  36284.   */

  36285.   SimulateDiskfullError( return SQLITE_FULL );

  36286. 

  36287.   assert( pFile );

  36288.   OSTRACE(("SYNC    %-3d\n", pFile->h));

  36289.   rc = full_fsync(pFile->h, isFullsync, isDataOnly);

  36290.   SimulateIOError( rc=1 );

  36291.   if( rc ){

  36292.     storeLastErrno(pFile, errno);

  36293.     return unixLogError(SQLITE_IOERR_FSYNC, "full_fsync", pFile->zPath);

  36294.   }

  36295. 

  36296.   /* Also fsync the directory containing the file if the DIRSYNC flag

  36297.   ** is set.  This is a one-time occurrence.  Many systems (examples: AIX)

  36298.   ** are unable to fsync a directory, so ignore errors on the fsync.

  36299.   */

  36300.   if( pFile->ctrlFlags & UNIXFILE_DIRSYNC ){

  36301.     int dirfd;

  36302.     OSTRACE(("DIRSYNC %s (have_fullfsync=%d fullsync=%d)\n", pFile->zPath,

  36303.             HAVE_FULLFSYNC, isFullsync));

  36304.     rc = osOpenDirectory(pFile->zPath, &dirfd);

  36305.     if( rc==SQLITE_OK ){

  36306.       full_fsync(dirfd, 0, 0);

  36307.       robust_close(pFile, dirfd, __LINE__);

  36308.     }else{

  36309.       assert( rc==SQLITE_CANTOPEN );

  36310.       rc = SQLITE_OK;

  36311.     }

  36312.     pFile->ctrlFlags &= ~UNIXFILE_DIRSYNC;

  36313.   }

  36314.   return rc;

  36315. }

  36316. 

  36317. /*

  36318. ** Truncate an open file to a specified size

  36319. */

  36320. static int unixTruncate(sqlite3_file *id, i64 nByte){

  36321.   unixFile *pFile = (unixFile *)id;

  36322.   int rc;

  36323.   assert( pFile );

  36324.   SimulateIOError( return SQLITE_IOERR_TRUNCATE );

  36325. 

  36326.   /* If the user has configured a chunk-size for this file, truncate the

  36327.   ** file so that it consists of an integer number of chunks (i.e. the

  36328.   ** actual file size after the operation may be larger than the requested

  36329.   ** size).

  36330.   */

  36331.   if( pFile->szChunk>0 ){

  36332.     nByte = ((nByte + pFile->szChunk - 1)/pFile->szChunk) * pFile->szChunk;

  36333.   }

  36334. 

  36335.   rc = robust_ftruncate(pFile->h, nByte);

  36336.   if( rc ){

  36337.     storeLastErrno(pFile, errno);

  36338.     return unixLogError(SQLITE_IOERR_TRUNCATE, "ftruncate", pFile->zPath);

  36339.   }else{

  36340. #ifdef SQLITE_DEBUG

  36341.     /* If we are doing a normal write to a database file (as opposed to

  36342.     ** doing a hot-journal rollback or a write to some file other than a

  36343.     ** normal database file) and we truncate the file to zero length,

  36344.     ** that effectively updates the change counter.  This might happen

  36345.     ** when restoring a database using the backup API from a zero-length

  36346.     ** source.

  36347.     */

  36348.     if( pFile->inNormalWrite && nByte==0 ){

  36349.       pFile->transCntrChng = 1;

  36350.     }

  36351. #endif

  36352. 

  36353. #if SQLITE_MAX_MMAP_SIZE>0

  36354.     /* If the file was just truncated to a size smaller than the currently

  36355.     ** mapped region, reduce the effective mapping size as well. SQLite will

  36356.     ** use read() and write() to access data beyond this point from now on.  

  36357.     */

  36358.     if( nByte<pFile->mmapSize ){

  36359.       pFile->mmapSize = nByte;

  36360.     }

  36361. #endif

  36362. 

  36363.     return SQLITE_OK;

  36364.   }

  36365. }

  36366. 

  36367. /*

  36368. ** Determine the current size of a file in bytes

  36369. */

  36370. static int unixFileSize(sqlite3_file *id, i64 *pSize){

  36371.   int rc;

  36372.   struct stat buf;

  36373.   assert( id );

  36374.   rc = osFstat(((unixFile*)id)->h, &buf);

  36375.   SimulateIOError( rc=1 );

  36376.   if( rc!=0 ){

  36377.     storeLastErrno((unixFile*)id, errno);

  36378.     return SQLITE_IOERR_FSTAT;

  36379.   }

  36380.   *pSize = buf.st_size;

  36381. 

  36382.   /* When opening a zero-size database, the findInodeInfo() procedure

  36383.   ** writes a single byte into that file in order to work around a bug

  36384.   ** in the OS-X msdos filesystem.  In order to avoid problems with upper

  36385.   ** layers, we need to report this file size as zero even though it is

  36386.   ** really 1.   Ticket #3260.

  36387.   */

  36388.   if( *pSize==1 ) *pSize = 0;

  36389. 

  36390. 

  36391.   return SQLITE_OK;

  36392. }

  36393. 

  36394. #if SQLITE_ENABLE_LOCKING_STYLE && defined(__APPLE__)

  36395. /*

  36396. ** Handler for proxy-locking file-control verbs.  Defined below in the

  36397. ** proxying locking division.

  36398. */

  36399. static int proxyFileControl(sqlite3_file*,int,void*);

  36400. #endif

  36401. 

  36402. /* 

  36403. ** This function is called to handle the SQLITE_FCNTL_SIZE_HINT 

  36404. ** file-control operation.  Enlarge the database to nBytes in size

  36405. ** (rounded up to the next chunk-size).  If the database is already

  36406. ** nBytes or larger, this routine is a no-op.

  36407. */

  36408. static int fcntlSizeHint(unixFile *pFile, i64 nByte){

  36409.   if( pFile->szChunk>0 ){

  36410.     i64 nSize;                    /* Required file size */

  36411.     struct stat buf;              /* Used to hold return values of fstat() */

  36412.    

  36413.     if( osFstat(pFile->h, &buf) ){

  36414.       return SQLITE_IOERR_FSTAT;

  36415.     }

  36416. 

  36417.     nSize = ((nByte+pFile->szChunk-1) / pFile->szChunk) * pFile->szChunk;

  36418.     if( nSize>(i64)buf.st_size ){

  36419. 

  36420. #if defined(HAVE_POSIX_FALLOCATE) && HAVE_POSIX_FALLOCATE

  36421.       /* The code below is handling the return value of osFallocate() 

  36422.       ** correctly. posix_fallocate() is defined to "returns zero on success, 

  36423.       ** or an error number on  failure". See the manpage for details. */

  36424.       int err;

  36425.       do{

  36426.         err = osFallocate(pFile->h, buf.st_size, nSize-buf.st_size);

  36427.       }while( err==EINTR );

  36428.       if( err && err!=EINVAL ) return SQLITE_IOERR_WRITE;

  36429. #else

  36430.       /* If the OS does not have posix_fallocate(), fake it. Write a 

  36431.       ** single byte to the last byte in each block that falls entirely

  36432.       ** within the extended region. Then, if required, a single byte

  36433.       ** at offset (nSize-1), to set the size of the file correctly.

  36434.       ** This is a similar technique to that used by glibc on systems

  36435.       ** that do not have a real fallocate() call.

  36436.       */

  36437.       int nBlk = buf.st_blksize;  /* File-system block size */

  36438.       int nWrite = 0;             /* Number of bytes written by seekAndWrite */

  36439.       i64 iWrite;                 /* Next offset to write to */

  36440. 

  36441.       iWrite = (buf.st_size/nBlk)*nBlk + nBlk - 1;

  36442.       assert( iWrite>=buf.st_size );

  36443.       assert( ((iWrite+1)%nBlk)==0 );

  36444.       for(/*no-op*/; iWrite<nSize+nBlk-1; iWrite+=nBlk ){

  36445.         if( iWrite>=nSize ) iWrite = nSize - 1;

  36446.         nWrite = seekAndWrite(pFile, iWrite, "", 1);

  36447.         if( nWrite!=1 ) return SQLITE_IOERR_WRITE;

  36448.       }

  36449. #endif

  36450.     }

  36451.   }

  36452. 

  36453. #if SQLITE_MAX_MMAP_SIZE>0

  36454.   if( pFile->mmapSizeMax>0 && nByte>pFile->mmapSize ){

  36455.     int rc;

  36456.     if( pFile->szChunk<=0 ){

  36457.       if( robust_ftruncate(pFile->h, nByte) ){

  36458.         storeLastErrno(pFile, errno);

  36459.         return unixLogError(SQLITE_IOERR_TRUNCATE, "ftruncate", pFile->zPath);

  36460.       }

  36461.     }

  36462. 

  36463.     rc = unixMapfile(pFile, nByte);

  36464.     return rc;

  36465.   }

  36466. #endif

  36467. 

  36468.   return SQLITE_OK;

  36469. }

  36470. 

  36471. /*

  36472. ** If *pArg is initially negative then this is a query.  Set *pArg to

  36473. ** 1 or 0 depending on whether or not bit mask of pFile->ctrlFlags is set.

  36474. **

  36475. ** If *pArg is 0 or 1, then clear or set the mask bit of pFile->ctrlFlags.

  36476. */

  36477. static void unixModeBit(unixFile *pFile, unsigned char mask, int *pArg){

  36478.   if( *pArg<0 ){

  36479.     *pArg = (pFile->ctrlFlags & mask)!=0;

  36480.   }else if( (*pArg)==0 ){

  36481.     pFile->ctrlFlags &= ~mask;

  36482.   }else{

  36483.     pFile->ctrlFlags |= mask;

  36484.   }

  36485. }

  36486. 

  36487. /* Forward declaration */

  36488. static int unixGetTempname(int nBuf, char *zBuf);

  36489. 

  36490. /*

  36491. ** Information and control of an open file handle.

  36492. */

  36493. static int unixFileControl(sqlite3_file *id, int op, void *pArg){

  36494.   unixFile *pFile = (unixFile*)id;

  36495.   switch( op ){

  36496. #if defined(__linux__) && defined(SQLITE_ENABLE_BATCH_ATOMIC_WRITE)

  36497.     case SQLITE_FCNTL_BEGIN_ATOMIC_WRITE: {

  36498.       int rc = osIoctl(pFile->h, F2FS_IOC_START_ATOMIC_WRITE);

  36499.       return rc ? SQLITE_IOERR_BEGIN_ATOMIC : SQLITE_OK;

  36500.     }

  36501.     case SQLITE_FCNTL_COMMIT_ATOMIC_WRITE: {

  36502.       int rc = osIoctl(pFile->h, F2FS_IOC_COMMIT_ATOMIC_WRITE);

  36503.       return rc ? SQLITE_IOERR_COMMIT_ATOMIC : SQLITE_OK;

  36504.     }

  36505.     case SQLITE_FCNTL_ROLLBACK_ATOMIC_WRITE: {

  36506.       int rc = osIoctl(pFile->h, F2FS_IOC_ABORT_VOLATILE_WRITE);

  36507.       return rc ? SQLITE_IOERR_ROLLBACK_ATOMIC : SQLITE_OK;

  36508.     }

  36509. #endif /* __linux__ && SQLITE_ENABLE_BATCH_ATOMIC_WRITE */

  36510. 

  36511.     case SQLITE_FCNTL_LOCKSTATE: {

  36512.       *(int*)pArg = pFile->eFileLock;

  36513.       return SQLITE_OK;

  36514.     }

  36515.     case SQLITE_FCNTL_LAST_ERRNO: {

  36516.       *(int*)pArg = pFile->lastErrno;

  36517.       return SQLITE_OK;

  36518.     }

  36519.     case SQLITE_FCNTL_CHUNK_SIZE: {

  36520.       pFile->szChunk = *(int *)pArg;

  36521.       return SQLITE_OK;

  36522.     }

  36523.     case SQLITE_FCNTL_SIZE_HINT: {

  36524.       int rc;

  36525.       SimulateIOErrorBenign(1);

  36526.       rc = fcntlSizeHint(pFile, *(i64 *)pArg);

  36527.       SimulateIOErrorBenign(0);

  36528.       return rc;

  36529.     }

  36530.     case SQLITE_FCNTL_PERSIST_WAL: {

  36531.       unixModeBit(pFile, UNIXFILE_PERSIST_WAL, (int*)pArg);

  36532.       return SQLITE_OK;

  36533.     }

  36534.     case SQLITE_FCNTL_POWERSAFE_OVERWRITE: {

  36535.       unixModeBit(pFile, UNIXFILE_PSOW, (int*)pArg);

  36536.       return SQLITE_OK;

  36537.     }

  36538.     case SQLITE_FCNTL_VFSNAME: {

  36539.       *(char**)pArg = sqlite3_mprintf("%s", pFile->pVfs->zName);

  36540.       return SQLITE_OK;

  36541.     }

  36542.     case SQLITE_FCNTL_TEMPFILENAME: {

  36543.       char *zTFile = sqlite3_malloc64( pFile->pVfs->mxPathname );

  36544.       if( zTFile ){

  36545.         unixGetTempname(pFile->pVfs->mxPathname, zTFile);

  36546.         *(char**)pArg = zTFile;

  36547.       }

  36548.       return SQLITE_OK;

  36549.     }

  36550.     case SQLITE_FCNTL_HAS_MOVED: {

  36551.       *(int*)pArg = fileHasMoved(pFile);

  36552.       return SQLITE_OK;

  36553.     }

  36554. #ifdef SQLITE_ENABLE_SETLK_TIMEOUT

  36555.     case SQLITE_FCNTL_LOCK_TIMEOUT: {

  36556.       pFile->iBusyTimeout = *(int*)pArg;

  36557.       return SQLITE_OK;

  36558.     }

  36559. #endif

  36560. #if SQLITE_MAX_MMAP_SIZE>0

  36561.     case SQLITE_FCNTL_MMAP_SIZE: {

  36562.       i64 newLimit = *(i64*)pArg;

  36563.       int rc = SQLITE_OK;

  36564.       if( newLimit>sqlite3GlobalConfig.mxMmap ){

  36565.         newLimit = sqlite3GlobalConfig.mxMmap;

  36566.       }

  36567. 

  36568.       /* The value of newLimit may be eventually cast to (size_t) and passed

  36569.       ** to mmap(). Restrict its value to 2GB if (size_t) is not at least a

  36570.       ** 64-bit type. */

  36571.       if( newLimit>0 && sizeof(size_t)<8 ){

  36572.         newLimit = (newLimit & 0x7FFFFFFF);

  36573.       }

  36574. 

  36575.       *(i64*)pArg = pFile->mmapSizeMax;

  36576.       if( newLimit>=0 && newLimit!=pFile->mmapSizeMax && pFile->nFetchOut==0 ){

  36577.         pFile->mmapSizeMax = newLimit;

  36578.         if( pFile->mmapSize>0 ){

  36579.           unixUnmapfile(pFile);

  36580.           rc = unixMapfile(pFile, -1);

  36581.         }

  36582.       }

  36583.       return rc;

  36584.     }

  36585. #endif

  36586. #ifdef SQLITE_DEBUG

  36587.     /* The pager calls this method to signal that it has done

  36588.     ** a rollback and that the database is therefore unchanged and

  36589.     ** it hence it is OK for the transaction change counter to be

  36590.     ** unchanged.

  36591.     */

  36592.     case SQLITE_FCNTL_DB_UNCHANGED: {

  36593.       ((unixFile*)id)->dbUpdate = 0;

  36594.       return SQLITE_OK;

  36595.     }

  36596. #endif

  36597. #if SQLITE_ENABLE_LOCKING_STYLE && defined(__APPLE__)

  36598.     case SQLITE_FCNTL_SET_LOCKPROXYFILE:

  36599.     case SQLITE_FCNTL_GET_LOCKPROXYFILE: {

  36600.       return proxyFileControl(id,op,pArg);

  36601.     }

  36602. #endif /* SQLITE_ENABLE_LOCKING_STYLE && defined(__APPLE__) */

  36603.   }

  36604.   return SQLITE_NOTFOUND;

  36605. }

  36606. 

  36607. /*

  36608. ** If pFd->sectorSize is non-zero when this function is called, it is a

  36609. ** no-op. Otherwise, the values of pFd->sectorSize and 

  36610. ** pFd->deviceCharacteristics are set according to the file-system 

  36611. ** characteristics. 

  36612. **

  36613. ** There are two versions of this function. One for QNX and one for all

  36614. ** other systems.

  36615. */

  36616. #ifndef __QNXNTO__

  36617. static void setDeviceCharacteristics(unixFile *pFd){

  36618.   assert( pFd->deviceCharacteristics==0 || pFd->sectorSize!=0 );

  36619.   if( pFd->sectorSize==0 ){

  36620. #if defined(__linux__) && defined(SQLITE_ENABLE_BATCH_ATOMIC_WRITE)

  36621.     int res;

  36622.     u32 f = 0;

  36623. 

  36624.     /* Check for support for F2FS atomic batch writes. */

  36625.     res = osIoctl(pFd->h, F2FS_IOC_GET_FEATURES, &f);

  36626.     if( res==0 && (f & F2FS_FEATURE_ATOMIC_WRITE) ){

  36627.       pFd->deviceCharacteristics = SQLITE_IOCAP_BATCH_ATOMIC;

  36628.     }

  36629. #endif /* __linux__ && SQLITE_ENABLE_BATCH_ATOMIC_WRITE */

  36630. 

  36631.     /* Set the POWERSAFE_OVERWRITE flag if requested. */

  36632.     if( pFd->ctrlFlags & UNIXFILE_PSOW ){

  36633.       pFd->deviceCharacteristics |= SQLITE_IOCAP_POWERSAFE_OVERWRITE;

  36634.     }

  36635. 

  36636.     pFd->sectorSize = SQLITE_DEFAULT_SECTOR_SIZE;

  36637.   }

  36638. }

  36639. #else

  36640. #include <sys/dcmd_blk.h>

  36641. #include <sys/statvfs.h>

  36642. static void setDeviceCharacteristics(unixFile *pFile){

  36643.   if( pFile->sectorSize == 0 ){

  36644.     struct statvfs fsInfo;

  36645.        

  36646.     /* Set defaults for non-supported filesystems */

  36647.     pFile->sectorSize = SQLITE_DEFAULT_SECTOR_SIZE;

  36648.     pFile->deviceCharacteristics = 0;

  36649.     if( fstatvfs(pFile->h, &fsInfo) == -1 ) {

  36650.       return;

  36651.     }

  36652. 

  36653.     if( !strcmp(fsInfo.f_basetype, "tmp") ) {

  36654.       pFile->sectorSize = fsInfo.f_bsize;

  36655.       pFile->deviceCharacteristics =

  36656.         SQLITE_IOCAP_ATOMIC4K |       /* All ram filesystem writes are atomic */

  36657.         SQLITE_IOCAP_SAFE_APPEND |    /* growing the file does not occur until

  36658.                                       ** the write succeeds */

  36659.         SQLITE_IOCAP_SEQUENTIAL |     /* The ram filesystem has no write behind

  36660.                                       ** so it is ordered */

  36661.         0;

  36662.     }else if( strstr(fsInfo.f_basetype, "etfs") ){

  36663.       pFile->sectorSize = fsInfo.f_bsize;

  36664.       pFile->deviceCharacteristics =

  36665.         /* etfs cluster size writes are atomic */

  36666.         (pFile->sectorSize / 512 * SQLITE_IOCAP_ATOMIC512) |

  36667.         SQLITE_IOCAP_SAFE_APPEND |    /* growing the file does not occur until

  36668.                                       ** the write succeeds */

  36669.         SQLITE_IOCAP_SEQUENTIAL |     /* The ram filesystem has no write behind

  36670.                                       ** so it is ordered */

  36671.         0;

  36672.     }else if( !strcmp(fsInfo.f_basetype, "qnx6") ){

  36673.       pFile->sectorSize = fsInfo.f_bsize;

  36674.       pFile->deviceCharacteristics =

  36675.         SQLITE_IOCAP_ATOMIC |         /* All filesystem writes are atomic */

  36676.         SQLITE_IOCAP_SAFE_APPEND |    /* growing the file does not occur until

  36677.                                       ** the write succeeds */

  36678.         SQLITE_IOCAP_SEQUENTIAL |     /* The ram filesystem has no write behind

  36679.                                       ** so it is ordered */

  36680.         0;

  36681.     }else if( !strcmp(fsInfo.f_basetype, "qnx4") ){

  36682.       pFile->sectorSize = fsInfo.f_bsize;

  36683.       pFile->deviceCharacteristics =

  36684.         /* full bitset of atomics from max sector size and smaller */

  36685.         ((pFile->sectorSize / 512 * SQLITE_IOCAP_ATOMIC512) << 1) - 2 |

  36686.         SQLITE_IOCAP_SEQUENTIAL |     /* The ram filesystem has no write behind

  36687.                                       ** so it is ordered */

  36688.         0;

  36689.     }else if( strstr(fsInfo.f_basetype, "dos") ){

  36690.       pFile->sectorSize = fsInfo.f_bsize;

  36691.       pFile->deviceCharacteristics =

  36692.         /* full bitset of atomics from max sector size and smaller */

  36693.         ((pFile->sectorSize / 512 * SQLITE_IOCAP_ATOMIC512) << 1) - 2 |

  36694.         SQLITE_IOCAP_SEQUENTIAL |     /* The ram filesystem has no write behind

  36695.                                       ** so it is ordered */

  36696.         0;

  36697.     }else{

  36698.       pFile->deviceCharacteristics =

  36699.         SQLITE_IOCAP_ATOMIC512 |      /* blocks are atomic */

  36700.         SQLITE_IOCAP_SAFE_APPEND |    /* growing the file does not occur until

  36701.                                       ** the write succeeds */

  36702.         0;

  36703.     }

  36704.   }

  36705.   /* Last chance verification.  If the sector size isn't a multiple of 512

  36706.   ** then it isn't valid.*/

  36707.   if( pFile->sectorSize % 512 != 0 ){

  36708.     pFile->deviceCharacteristics = 0;

  36709.     pFile->sectorSize = SQLITE_DEFAULT_SECTOR_SIZE;

  36710.   }

  36711. }

  36712. #endif

  36713. 

  36714. /*

  36715. ** Return the sector size in bytes of the underlying block device for

  36716. ** the specified file. This is almost always 512 bytes, but may be

  36717. ** larger for some devices.

  36718. **

  36719. ** SQLite code assumes this function cannot fail. It also assumes that

  36720. ** if two files are created in the same file-system directory (i.e.

  36721. ** a database and its journal file) that the sector size will be the

  36722. ** same for both.

  36723. */

  36724. static int unixSectorSize(sqlite3_file *id){

  36725.   unixFile *pFd = (unixFile*)id;

  36726.   setDeviceCharacteristics(pFd);

  36727.   return pFd->sectorSize;

  36728. }

  36729. 

  36730. /*

  36731. ** Return the device characteristics for the file.

  36732. **

  36733. ** This VFS is set up to return SQLITE_IOCAP_POWERSAFE_OVERWRITE by default.

  36734. ** However, that choice is controversial since technically the underlying

  36735. ** file system does not always provide powersafe overwrites.  (In other

  36736. ** words, after a power-loss event, parts of the file that were never

  36737. ** written might end up being altered.)  However, non-PSOW behavior is very,

  36738. ** very rare.  And asserting PSOW makes a large reduction in the amount

  36739. ** of required I/O for journaling, since a lot of padding is eliminated.

  36740. **  Hence, while POWERSAFE_OVERWRITE is on by default, there is a file-control

  36741. ** available to turn it off and URI query parameter available to turn it off.

  36742. */

  36743. static int unixDeviceCharacteristics(sqlite3_file *id){

  36744.   unixFile *pFd = (unixFile*)id;

  36745.   setDeviceCharacteristics(pFd);

  36746.   return pFd->deviceCharacteristics;

  36747. }

  36748. 

  36749. #if !defined(SQLITE_OMIT_WAL) || SQLITE_MAX_MMAP_SIZE>0

  36750. 

  36751. /*

  36752. ** Return the system page size.

  36753. **

  36754. ** This function should not be called directly by other code in this file. 

  36755. ** Instead, it should be called via macro osGetpagesize().

  36756. */

  36757. static int unixGetpagesize(void){

  36758. #if OS_VXWORKS

  36759.   return 1024;

  36760. #elif defined(_BSD_SOURCE)

  36761.   return getpagesize();

  36762. #else

  36763.   return (int)sysconf(_SC_PAGESIZE);

  36764. #endif

  36765. }

  36766. 

  36767. #endif /* !defined(SQLITE_OMIT_WAL) || SQLITE_MAX_MMAP_SIZE>0 */

  36768. 

  36769. #ifndef SQLITE_OMIT_WAL

  36770. 

  36771. /*

  36772. ** Object used to represent an shared memory buffer.  

  36773. **

  36774. ** When multiple threads all reference the same wal-index, each thread

  36775. ** has its own unixShm object, but they all point to a single instance

  36776. ** of this unixShmNode object.  In other words, each wal-index is opened

  36777. ** only once per process.

  36778. **

  36779. ** Each unixShmNode object is connected to a single unixInodeInfo object.

  36780. ** We could coalesce this object into unixInodeInfo, but that would mean

  36781. ** every open file that does not use shared memory (in other words, most

  36782. ** open files) would have to carry around this extra information.  So

  36783. ** the unixInodeInfo object contains a pointer to this unixShmNode object

  36784. ** and the unixShmNode object is created only when needed.

  36785. **

  36786. ** unixMutexHeld() must be true when creating or destroying

  36787. ** this object or while reading or writing the following fields:

  36788. **

  36789. **      nRef

  36790. **

  36791. ** The following fields are read-only after the object is created:

  36792. ** 

  36793. **      hShm

  36794. **      zFilename

  36795. **

  36796. ** Either unixShmNode.pShmMutex must be held or unixShmNode.nRef==0 and

  36797. ** unixMutexHeld() is true when reading or writing any other field

  36798. ** in this structure.

  36799. */

  36800. struct unixShmNode {

  36801.   unixInodeInfo *pInode;     /* unixInodeInfo that owns this SHM node */

  36802.   sqlite3_mutex *pShmMutex;  /* Mutex to access this object */

  36803.   char *zFilename;           /* Name of the mmapped file */

  36804.   int hShm;                  /* Open file descriptor */

  36805.   int szRegion;              /* Size of shared-memory regions */

  36806.   u16 nRegion;               /* Size of array apRegion */

  36807.   u8 isReadonly;             /* True if read-only */

  36808.   u8 isUnlocked;             /* True if no DMS lock held */

  36809.   char **apRegion;           /* Array of mapped shared-memory regions */

  36810.   int nRef;                  /* Number of unixShm objects pointing to this */

  36811.   unixShm *pFirst;           /* All unixShm objects pointing to this */

  36812. #ifdef SQLITE_DEBUG

  36813.   u8 exclMask;               /* Mask of exclusive locks held */

  36814.   u8 sharedMask;             /* Mask of shared locks held */

  36815.   u8 nextShmId;              /* Next available unixShm.id value */

  36816. #endif

  36817. };

  36818. 

  36819. /*

  36820. ** Structure used internally by this VFS to record the state of an

  36821. ** open shared memory connection.

  36822. **

  36823. ** The following fields are initialized when this object is created and

  36824. ** are read-only thereafter:

  36825. **

  36826. **    unixShm.pShmNode

  36827. **    unixShm.id

  36828. **

  36829. ** All other fields are read/write.  The unixShm.pShmNode->pShmMutex must

  36830. ** be held while accessing any read/write fields.

  36831. */

  36832. struct unixShm {

  36833.   unixShmNode *pShmNode;     /* The underlying unixShmNode object */

  36834.   unixShm *pNext;            /* Next unixShm with the same unixShmNode */

  36835.   u8 hasMutex;               /* True if holding the unixShmNode->pShmMutex */

  36836.   u8 id;                     /* Id of this connection within its unixShmNode */

  36837.   u16 sharedMask;            /* Mask of shared locks held */

  36838.   u16 exclMask;              /* Mask of exclusive locks held */

  36839. };

  36840. 

  36841. /*

  36842. ** Constants used for locking

  36843. */

  36844. #define UNIX_SHM_BASE   ((22+SQLITE_SHM_NLOCK)*4)         /* first lock byte */

  36845. #define UNIX_SHM_DMS    (UNIX_SHM_BASE+SQLITE_SHM_NLOCK)  /* deadman switch */

  36846. 

  36847. /*

  36848. ** Apply posix advisory locks for all bytes from ofst through ofst+n-1.

  36849. **

  36850. ** Locks block if the mask is exactly UNIX_SHM_C and are non-blocking

  36851. ** otherwise.

  36852. */

  36853. static int unixShmSystemLock(

  36854.   unixFile *pFile,       /* Open connection to the WAL file */

  36855.   int lockType,          /* F_UNLCK, F_RDLCK, or F_WRLCK */

  36856.   int ofst,              /* First byte of the locking range */

  36857.   int n                  /* Number of bytes to lock */

  36858. ){

  36859.   unixShmNode *pShmNode; /* Apply locks to this open shared-memory segment */

  36860.   struct flock f;        /* The posix advisory locking structure */

  36861.   int rc = SQLITE_OK;    /* Result code form fcntl() */

  36862. 

  36863.   /* Access to the unixShmNode object is serialized by the caller */

  36864.   pShmNode = pFile->pInode->pShmNode;

  36865.   assert( pShmNode->nRef==0 || sqlite3_mutex_held(pShmNode->pShmMutex) );

  36866.   assert( pShmNode->nRef>0 || unixMutexHeld() );

  36867. 

  36868.   /* Shared locks never span more than one byte */

  36869.   assert( n==1 || lockType!=F_RDLCK );

  36870. 

  36871.   /* Locks are within range */

  36872.   assert( n>=1 && n<=SQLITE_SHM_NLOCK );

  36873. 

  36874.   if( pShmNode->hShm>=0 ){

  36875.     /* Initialize the locking parameters */

  36876.     f.l_type = lockType;

  36877.     f.l_whence = SEEK_SET;

  36878.     f.l_start = ofst;

  36879.     f.l_len = n;

  36880.     rc = osSetPosixAdvisoryLock(pShmNode->hShm, &f, pFile);

  36881.     rc = (rc!=(-1)) ? SQLITE_OK : SQLITE_BUSY;

  36882.   }

  36883. 

  36884.   /* Update the global lock state and do debug tracing */

  36885. #ifdef SQLITE_DEBUG

  36886.   { u16 mask;

  36887.   OSTRACE(("SHM-LOCK "));

  36888.   mask = ofst>31 ? 0xffff : (1<<(ofst+n)) - (1<<ofst);

  36889.   if( rc==SQLITE_OK ){

  36890.     if( lockType==F_UNLCK ){

  36891.       OSTRACE(("unlock %d ok", ofst));

  36892.       pShmNode->exclMask &= ~mask;

  36893.       pShmNode->sharedMask &= ~mask;

  36894.     }else if( lockType==F_RDLCK ){

  36895.       OSTRACE(("read-lock %d ok", ofst));

  36896.       pShmNode->exclMask &= ~mask;

  36897.       pShmNode->sharedMask |= mask;

  36898.     }else{

  36899.       assert( lockType==F_WRLCK );

  36900.       OSTRACE(("write-lock %d ok", ofst));

  36901.       pShmNode->exclMask |= mask;

  36902.       pShmNode->sharedMask &= ~mask;

  36903.     }

  36904.   }else{

  36905.     if( lockType==F_UNLCK ){

  36906.       OSTRACE(("unlock %d failed", ofst));

  36907.     }else if( lockType==F_RDLCK ){

  36908.       OSTRACE(("read-lock failed"));

  36909.     }else{

  36910.       assert( lockType==F_WRLCK );

  36911.       OSTRACE(("write-lock %d failed", ofst));

  36912.     }

  36913.   }

  36914.   OSTRACE((" - afterwards %03x,%03x\n",

  36915.            pShmNode->sharedMask, pShmNode->exclMask));

  36916.   }

  36917. #endif

  36918. 

  36919.   return rc;        

  36920. }

  36921. 

  36922. /*

  36923. ** Return the minimum number of 32KB shm regions that should be mapped at

  36924. ** a time, assuming that each mapping must be an integer multiple of the

  36925. ** current system page-size.

  36926. **

  36927. ** Usually, this is 1. The exception seems to be systems that are configured

  36928. ** to use 64KB pages - in this case each mapping must cover at least two

  36929. ** shm regions.

  36930. */

  36931. static int unixShmRegionPerMap(void){

  36932.   int shmsz = 32*1024;            /* SHM region size */

  36933.   int pgsz = osGetpagesize();   /* System page size */

  36934.   assert( ((pgsz-1)&pgsz)==0 );   /* Page size must be a power of 2 */

  36935.   if( pgsz<shmsz ) return 1;

  36936.   return pgsz/shmsz;

  36937. }

  36938. 

  36939. /*

  36940. ** Purge the unixShmNodeList list of all entries with unixShmNode.nRef==0.

  36941. **

  36942. ** This is not a VFS shared-memory method; it is a utility function called

  36943. ** by VFS shared-memory methods.

  36944. */

  36945. static void unixShmPurge(unixFile *pFd){

  36946.   unixShmNode *p = pFd->pInode->pShmNode;

  36947.   assert( unixMutexHeld() );

  36948.   if( p && ALWAYS(p->nRef==0) ){

  36949.     int nShmPerMap = unixShmRegionPerMap();

  36950.     int i;

  36951.     assert( p->pInode==pFd->pInode );

  36952.     sqlite3_mutex_free(p->pShmMutex);

  36953.     for(i=0; i<p->nRegion; i+=nShmPerMap){

  36954.       if( p->hShm>=0 ){

  36955.         osMunmap(p->apRegion[i], p->szRegion);

  36956.       }else{

  36957.         sqlite3_free(p->apRegion[i]);

  36958.       }

  36959.     }

  36960.     sqlite3_free(p->apRegion);

  36961.     if( p->hShm>=0 ){

  36962.       robust_close(pFd, p->hShm, __LINE__);

  36963.       p->hShm = -1;

  36964.     }

  36965.     p->pInode->pShmNode = 0;

  36966.     sqlite3_free(p);

  36967.   }

  36968. }

  36969. 

  36970. /*

  36971. ** The DMS lock has not yet been taken on shm file pShmNode. Attempt to

  36972. ** take it now. Return SQLITE_OK if successful, or an SQLite error

  36973. ** code otherwise.

  36974. **

  36975. ** If the DMS cannot be locked because this is a readonly_shm=1 

  36976. ** connection and no other process already holds a lock, return

  36977. ** SQLITE_READONLY_CANTINIT and set pShmNode->isUnlocked=1.

  36978. */

  36979. static int unixLockSharedMemory(unixFile *pDbFd, unixShmNode *pShmNode){

  36980.   struct flock lock;

  36981.   int rc = SQLITE_OK;

  36982. 

  36983.   /* Use F_GETLK to determine the locks other processes are holding

  36984.   ** on the DMS byte. If it indicates that another process is holding

  36985.   ** a SHARED lock, then this process may also take a SHARED lock

  36986.   ** and proceed with opening the *-shm file. 

  36987.   **

  36988.   ** Or, if no other process is holding any lock, then this process

  36989.   ** is the first to open it. In this case take an EXCLUSIVE lock on the

  36990.   ** DMS byte and truncate the *-shm file to zero bytes in size. Then

  36991.   ** downgrade to a SHARED lock on the DMS byte.

  36992.   **

  36993.   ** If another process is holding an EXCLUSIVE lock on the DMS byte,

  36994.   ** return SQLITE_BUSY to the caller (it will try again). An earlier

  36995.   ** version of this code attempted the SHARED lock at this point. But

  36996.   ** this introduced a subtle race condition: if the process holding

  36997.   ** EXCLUSIVE failed just before truncating the *-shm file, then this

  36998.   ** process might open and use the *-shm file without truncating it.

  36999.   ** And if the *-shm file has been corrupted by a power failure or

  37000.   ** system crash, the database itself may also become corrupt.  */

  37001.   lock.l_whence = SEEK_SET;

  37002.   lock.l_start = UNIX_SHM_DMS;

  37003.   lock.l_len = 1;

  37004.   lock.l_type = F_WRLCK;

  37005.   if( osFcntl(pShmNode->hShm, F_GETLK, &lock)!=0 ) {

  37006.     rc = SQLITE_IOERR_LOCK;

  37007.   }else if( lock.l_type==F_UNLCK ){

  37008.     if( pShmNode->isReadonly ){

  37009.       pShmNode->isUnlocked = 1;

  37010.       rc = SQLITE_READONLY_CANTINIT;

  37011.     }else{

  37012.       rc = unixShmSystemLock(pDbFd, F_WRLCK, UNIX_SHM_DMS, 1);

  37013.       /* The first connection to attach must truncate the -shm file.  We

  37014.       ** truncate to 3 bytes (an arbitrary small number, less than the

  37015.       ** -shm header size) rather than 0 as a system debugging aid, to

  37016.       ** help detect if a -shm file truncation is legitimate or is the work

  37017.       ** or a rogue process. */

  37018.       if( rc==SQLITE_OK && robust_ftruncate(pShmNode->hShm, 3) ){

  37019.         rc = unixLogError(SQLITE_IOERR_SHMOPEN,"ftruncate",pShmNode->zFilename);

  37020.       }

  37021.     }

  37022.   }else if( lock.l_type==F_WRLCK ){

  37023.     rc = SQLITE_BUSY;

  37024.   }

  37025. 

  37026.   if( rc==SQLITE_OK ){

  37027.     assert( lock.l_type==F_UNLCK || lock.l_type==F_RDLCK );

  37028.     rc = unixShmSystemLock(pDbFd, F_RDLCK, UNIX_SHM_DMS, 1);

  37029.   }

  37030.   return rc;

  37031. }

  37032. 

  37033. /*

  37034. ** Open a shared-memory area associated with open database file pDbFd.  

  37035. ** This particular implementation uses mmapped files.

  37036. **

  37037. ** The file used to implement shared-memory is in the same directory

  37038. ** as the open database file and has the same name as the open database

  37039. ** file with the "-shm" suffix added.  For example, if the database file

  37040. ** is "/home/user1/config.db" then the file that is created and mmapped

  37041. ** for shared memory will be called "/home/user1/config.db-shm".  

  37042. **

  37043. ** Another approach to is to use files in /dev/shm or /dev/tmp or an

  37044. ** some other tmpfs mount. But if a file in a different directory

  37045. ** from the database file is used, then differing access permissions

  37046. ** or a chroot() might cause two different processes on the same

  37047. ** database to end up using different files for shared memory - 

  37048. ** meaning that their memory would not really be shared - resulting

  37049. ** in database corruption.  Nevertheless, this tmpfs file usage

  37050. ** can be enabled at compile-time using -DSQLITE_SHM_DIRECTORY="/dev/shm"

  37051. ** or the equivalent.  The use of the SQLITE_SHM_DIRECTORY compile-time

  37052. ** option results in an incompatible build of SQLite;  builds of SQLite

  37053. ** that with differing SQLITE_SHM_DIRECTORY settings attempt to use the

  37054. ** same database file at the same time, database corruption will likely

  37055. ** result. The SQLITE_SHM_DIRECTORY compile-time option is considered

  37056. ** "unsupported" and may go away in a future SQLite release.

  37057. **

  37058. ** When opening a new shared-memory file, if no other instances of that

  37059. ** file are currently open, in this process or in other processes, then

  37060. ** the file must be truncated to zero length or have its header cleared.

  37061. **

  37062. ** If the original database file (pDbFd) is using the "unix-excl" VFS

  37063. ** that means that an exclusive lock is held on the database file and

  37064. ** that no other processes are able to read or write the database.  In

  37065. ** that case, we do not really need shared memory.  No shared memory

  37066. ** file is created.  The shared memory will be simulated with heap memory.

  37067. */

  37068. static int unixOpenSharedMemory(unixFile *pDbFd){

  37069.   struct unixShm *p = 0;          /* The connection to be opened */

  37070.   struct unixShmNode *pShmNode;   /* The underlying mmapped file */

  37071.   int rc = SQLITE_OK;             /* Result code */

  37072.   unixInodeInfo *pInode;          /* The inode of fd */

  37073.   char *zShm;             /* Name of the file used for SHM */

  37074.   int nShmFilename;               /* Size of the SHM filename in bytes */

  37075. 

  37076.   /* Allocate space for the new unixShm object. */

  37077.   p = sqlite3_malloc64( sizeof(*p) );

  37078.   if( p==0 ) return SQLITE_NOMEM_BKPT;

  37079.   memset(p, 0, sizeof(*p));

  37080.   assert( pDbFd->pShm==0 );

  37081. 

  37082.   /* Check to see if a unixShmNode object already exists. Reuse an existing

  37083.   ** one if present. Create a new one if necessary.

  37084.   */

  37085.   assert( unixFileMutexNotheld(pDbFd) );

  37086.   unixEnterMutex();

  37087.   pInode = pDbFd->pInode;

  37088.   pShmNode = pInode->pShmNode;

  37089.   if( pShmNode==0 ){

  37090.     struct stat sStat;                 /* fstat() info for database file */

  37091. #ifndef SQLITE_SHM_DIRECTORY

  37092.     const char *zBasePath = pDbFd->zPath;

  37093. #endif

  37094. 

  37095.     /* Call fstat() to figure out the permissions on the database file. If

  37096.     ** a new *-shm file is created, an attempt will be made to create it

  37097.     ** with the same permissions.

  37098.     */

  37099.     if( osFstat(pDbFd->h, &sStat) ){

  37100.       rc = SQLITE_IOERR_FSTAT;

  37101.       goto shm_open_err;

  37102.     }

  37103. 

  37104. #ifdef SQLITE_SHM_DIRECTORY

  37105.     nShmFilename = sizeof(SQLITE_SHM_DIRECTORY) + 31;

  37106. #else

  37107.     nShmFilename = 6 + (int)strlen(zBasePath);

  37108. #endif

  37109.     pShmNode = sqlite3_malloc64( sizeof(*pShmNode) + nShmFilename );

  37110.     if( pShmNode==0 ){

  37111.       rc = SQLITE_NOMEM_BKPT;

  37112.       goto shm_open_err;

  37113.     }

  37114.     memset(pShmNode, 0, sizeof(*pShmNode)+nShmFilename);

  37115.     zShm = pShmNode->zFilename = (char*)&pShmNode[1];

  37116. #ifdef SQLITE_SHM_DIRECTORY

  37117.     sqlite3_snprintf(nShmFilename, zShm, 

  37118.                      SQLITE_SHM_DIRECTORY "/sqlite-shm-%x-%x",

  37119.                      (u32)sStat.st_ino, (u32)sStat.st_dev);

  37120. #else

  37121.     sqlite3_snprintf(nShmFilename, zShm, "%s-shm", zBasePath);

  37122.     sqlite3FileSuffix3(pDbFd->zPath, zShm);

  37123. #endif

  37124.     pShmNode->hShm = -1;

  37125.     pDbFd->pInode->pShmNode = pShmNode;

  37126.     pShmNode->pInode = pDbFd->pInode;

  37127.     if( sqlite3GlobalConfig.bCoreMutex ){

  37128.       pShmNode->pShmMutex = sqlite3_mutex_alloc(SQLITE_MUTEX_FAST);

  37129.       if( pShmNode->pShmMutex==0 ){

  37130.         rc = SQLITE_NOMEM_BKPT;

  37131.         goto shm_open_err;

  37132.       }

  37133.     }

  37134. 

  37135.     if( pInode->bProcessLock==0 ){

  37136.       if( 0==sqlite3_uri_boolean(pDbFd->zPath, "readonly_shm", 0) ){

  37137.         pShmNode->hShm = robust_open(zShm, O_RDWR|O_CREAT,(sStat.st_mode&0777));

  37138.       }

  37139.       if( pShmNode->hShm<0 ){

  37140.         pShmNode->hShm = robust_open(zShm, O_RDONLY, (sStat.st_mode&0777));

  37141.         if( pShmNode->hShm<0 ){

  37142.           rc = unixLogError(SQLITE_CANTOPEN_BKPT, "open", zShm);

  37143.           goto shm_open_err;

  37144.         }

  37145.         pShmNode->isReadonly = 1;

  37146.       }

  37147. 

  37148.       /* If this process is running as root, make sure that the SHM file

  37149.       ** is owned by the same user that owns the original database.  Otherwise,

  37150.       ** the original owner will not be able to connect.

  37151.       */

  37152.       robustFchown(pShmNode->hShm, sStat.st_uid, sStat.st_gid);

  37153. 

  37154.       rc = unixLockSharedMemory(pDbFd, pShmNode);

  37155.       if( rc!=SQLITE_OK && rc!=SQLITE_READONLY_CANTINIT ) goto shm_open_err;

  37156.     }

  37157.   }

  37158. 

  37159.   /* Make the new connection a child of the unixShmNode */

  37160.   p->pShmNode = pShmNode;

  37161. #ifdef SQLITE_DEBUG

  37162.   p->id = pShmNode->nextShmId++;

  37163. #endif

  37164.   pShmNode->nRef++;

  37165.   pDbFd->pShm = p;

  37166.   unixLeaveMutex();

  37167. 

  37168.   /* The reference count on pShmNode has already been incremented under

  37169.   ** the cover of the unixEnterMutex() mutex and the pointer from the

  37170.   ** new (struct unixShm) object to the pShmNode has been set. All that is

  37171.   ** left to do is to link the new object into the linked list starting

  37172.   ** at pShmNode->pFirst. This must be done while holding the

  37173.   ** pShmNode->pShmMutex.

  37174.   */

  37175.   sqlite3_mutex_enter(pShmNode->pShmMutex);

  37176.   p->pNext = pShmNode->pFirst;

  37177.   pShmNode->pFirst = p;

  37178.   sqlite3_mutex_leave(pShmNode->pShmMutex);

  37179.   return rc;

  37180. 

  37181.   /* Jump here on any error */

  37182. shm_open_err:

  37183.   unixShmPurge(pDbFd);       /* This call frees pShmNode if required */

  37184.   sqlite3_free(p);

  37185.   unixLeaveMutex();

  37186.   return rc;

  37187. }

  37188. 

  37189. /*

  37190. ** This function is called to obtain a pointer to region iRegion of the 

  37191. ** shared-memory associated with the database file fd. Shared-memory regions 

  37192. ** are numbered starting from zero. Each shared-memory region is szRegion 

  37193. ** bytes in size.

  37194. **

  37195. ** If an error occurs, an error code is returned and *pp is set to NULL.

  37196. **

  37197. ** Otherwise, if the bExtend parameter is 0 and the requested shared-memory

  37198. ** region has not been allocated (by any client, including one running in a

  37199. ** separate process), then *pp is set to NULL and SQLITE_OK returned. If 

  37200. ** bExtend is non-zero and the requested shared-memory region has not yet 

  37201. ** been allocated, it is allocated by this function.

  37202. **

  37203. ** If the shared-memory region has already been allocated or is allocated by

  37204. ** this call as described above, then it is mapped into this processes 

  37205. ** address space (if it is not already), *pp is set to point to the mapped 

  37206. ** memory and SQLITE_OK returned.

  37207. */

  37208. static int unixShmMap(

  37209.   sqlite3_file *fd,               /* Handle open on database file */

  37210.   int iRegion,                    /* Region to retrieve */

  37211.   int szRegion,                   /* Size of regions */

  37212.   int bExtend,                    /* True to extend file if necessary */

  37213.   void volatile **pp              /* OUT: Mapped memory */

  37214. ){

  37215.   unixFile *pDbFd = (unixFile*)fd;

  37216.   unixShm *p;

  37217.   unixShmNode *pShmNode;

  37218.   int rc = SQLITE_OK;

  37219.   int nShmPerMap = unixShmRegionPerMap();

  37220.   int nReqRegion;

  37221. 

  37222.   /* If the shared-memory file has not yet been opened, open it now. */

  37223.   if( pDbFd->pShm==0 ){

  37224.     rc = unixOpenSharedMemory(pDbFd);

  37225.     if( rc!=SQLITE_OK ) return rc;

  37226.   }

  37227. 

  37228.   p = pDbFd->pShm;

  37229.   pShmNode = p->pShmNode;

  37230.   sqlite3_mutex_enter(pShmNode->pShmMutex);

  37231.   if( pShmNode->isUnlocked ){

  37232.     rc = unixLockSharedMemory(pDbFd, pShmNode);

  37233.     if( rc!=SQLITE_OK ) goto shmpage_out;

  37234.     pShmNode->isUnlocked = 0;

  37235.   }

  37236.   assert( szRegion==pShmNode->szRegion || pShmNode->nRegion==0 );

  37237.   assert( pShmNode->pInode==pDbFd->pInode );

  37238.   assert( pShmNode->hShm>=0 || pDbFd->pInode->bProcessLock==1 );

  37239.   assert( pShmNode->hShm<0 || pDbFd->pInode->bProcessLock==0 );

  37240. 

  37241.   /* Minimum number of regions required to be mapped. */

  37242.   nReqRegion = ((iRegion+nShmPerMap) / nShmPerMap) * nShmPerMap;

  37243. 

  37244.   if( pShmNode->nRegion<nReqRegion ){

  37245.     char **apNew;                      /* New apRegion[] array */

  37246.     int nByte = nReqRegion*szRegion;   /* Minimum required file size */

  37247.     struct stat sStat;                 /* Used by fstat() */

  37248. 

  37249.     pShmNode->szRegion = szRegion;

  37250. 

  37251.     if( pShmNode->hShm>=0 ){

  37252.       /* The requested region is not mapped into this processes address space.

  37253.       ** Check to see if it has been allocated (i.e. if the wal-index file is

  37254.       ** large enough to contain the requested region).

  37255.       */

  37256.       if( osFstat(pShmNode->hShm, &sStat) ){

  37257.         rc = SQLITE_IOERR_SHMSIZE;

  37258.         goto shmpage_out;

  37259.       }

  37260.   

  37261.       if( sStat.st_size<nByte ){

  37262.         /* The requested memory region does not exist. If bExtend is set to

  37263.         ** false, exit early. *pp will be set to NULL and SQLITE_OK returned.

  37264.         */

  37265.         if( !bExtend ){

  37266.           goto shmpage_out;

  37267.         }

  37268. 

  37269.         /* Alternatively, if bExtend is true, extend the file. Do this by

  37270.         ** writing a single byte to the end of each (OS) page being

  37271.         ** allocated or extended. Technically, we need only write to the

  37272.         ** last page in order to extend the file. But writing to all new

  37273.         ** pages forces the OS to allocate them immediately, which reduces

  37274.         ** the chances of SIGBUS while accessing the mapped region later on.

  37275.         */

  37276.         else{

  37277.           static const int pgsz = 4096;

  37278.           int iPg;

  37279. 

  37280.           /* Write to the last byte of each newly allocated or extended page */

  37281.           assert( (nByte % pgsz)==0 );

  37282.           for(iPg=(sStat.st_size/pgsz); iPg<(nByte/pgsz); iPg++){

  37283.             int x = 0;

  37284.             if( seekAndWriteFd(pShmNode->hShm, iPg*pgsz + pgsz-1,"",1,&x)!=1 ){

  37285.               const char *zFile = pShmNode->zFilename;

  37286.               rc = unixLogError(SQLITE_IOERR_SHMSIZE, "write", zFile);

  37287.               goto shmpage_out;

  37288.             }

  37289.           }

  37290.         }

  37291.       }

  37292.     }

  37293. 

  37294.     /* Map the requested memory region into this processes address space. */

  37295.     apNew = (char **)sqlite3_realloc(

  37296.         pShmNode->apRegion, nReqRegion*sizeof(char *)

  37297.     );

  37298.     if( !apNew ){

  37299.       rc = SQLITE_IOERR_NOMEM_BKPT;

  37300.       goto shmpage_out;

  37301.     }

  37302.     pShmNode->apRegion = apNew;

  37303.     while( pShmNode->nRegion<nReqRegion ){

  37304.       int nMap = szRegion*nShmPerMap;

  37305.       int i;

  37306.       void *pMem;

  37307.       if( pShmNode->hShm>=0 ){

  37308.         pMem = osMmap(0, nMap,

  37309.             pShmNode->isReadonly ? PROT_READ : PROT_READ|PROT_WRITE, 

  37310.             MAP_SHARED, pShmNode->hShm, szRegion*(i64)pShmNode->nRegion

  37311.         );

  37312.         if( pMem==MAP_FAILED ){

  37313.           rc = unixLogError(SQLITE_IOERR_SHMMAP, "mmap", pShmNode->zFilename);

  37314.           goto shmpage_out;

  37315.         }

  37316.       }else{

  37317.         pMem = sqlite3_malloc64(nMap);

  37318.         if( pMem==0 ){

  37319.           rc = SQLITE_NOMEM_BKPT;

  37320.           goto shmpage_out;

  37321.         }

  37322.         memset(pMem, 0, nMap);

  37323.       }

  37324. 

  37325.       for(i=0; i<nShmPerMap; i++){

  37326.         pShmNode->apRegion[pShmNode->nRegion+i] = &((char*)pMem)[szRegion*i];

  37327.       }

  37328.       pShmNode->nRegion += nShmPerMap;

  37329.     }

  37330.   }

  37331. 

  37332. shmpage_out:

  37333.   if( pShmNode->nRegion>iRegion ){

  37334.     *pp = pShmNode->apRegion[iRegion];

  37335.   }else{

  37336.     *pp = 0;

  37337.   }

  37338.   if( pShmNode->isReadonly && rc==SQLITE_OK ) rc = SQLITE_READONLY;

  37339.   sqlite3_mutex_leave(pShmNode->pShmMutex);

  37340.   return rc;

  37341. }

  37342. 

  37343. /*

  37344. ** Change the lock state for a shared-memory segment.

  37345. **

  37346. ** Note that the relationship between SHAREd and EXCLUSIVE locks is a little

  37347. ** different here than in posix.  In xShmLock(), one can go from unlocked

  37348. ** to shared and back or from unlocked to exclusive and back.  But one may

  37349. ** not go from shared to exclusive or from exclusive to shared.

  37350. */

  37351. static int unixShmLock(

  37352.   sqlite3_file *fd,          /* Database file holding the shared memory */

  37353.   int ofst,                  /* First lock to acquire or release */

  37354.   int n,                     /* Number of locks to acquire or release */

  37355.   int flags                  /* What to do with the lock */

  37356. ){

  37357.   unixFile *pDbFd = (unixFile*)fd;      /* Connection holding shared memory */

  37358.   unixShm *p = pDbFd->pShm;             /* The shared memory being locked */

  37359.   unixShm *pX;                          /* For looping over all siblings */

  37360.   unixShmNode *pShmNode = p->pShmNode;  /* The underlying file iNode */

  37361.   int rc = SQLITE_OK;                   /* Result code */

  37362.   u16 mask;                             /* Mask of locks to take or release */

  37363. 

  37364.   assert( pShmNode==pDbFd->pInode->pShmNode );

  37365.   assert( pShmNode->pInode==pDbFd->pInode );

  37366.   assert( ofst>=0 && ofst+n<=SQLITE_SHM_NLOCK );

  37367.   assert( n>=1 );

  37368.   assert( flags==(SQLITE_SHM_LOCK | SQLITE_SHM_SHARED)

  37369.        || flags==(SQLITE_SHM_LOCK | SQLITE_SHM_EXCLUSIVE)

  37370.        || flags==(SQLITE_SHM_UNLOCK | SQLITE_SHM_SHARED)

  37371.        || flags==(SQLITE_SHM_UNLOCK | SQLITE_SHM_EXCLUSIVE) );

  37372.   assert( n==1 || (flags & SQLITE_SHM_EXCLUSIVE)!=0 );

  37373.   assert( pShmNode->hShm>=0 || pDbFd->pInode->bProcessLock==1 );

  37374.   assert( pShmNode->hShm<0 || pDbFd->pInode->bProcessLock==0 );

  37375. 

  37376.   mask = (1<<(ofst+n)) - (1<<ofst);

  37377.   assert( n>1 || mask==(1<<ofst) );

  37378.   sqlite3_mutex_enter(pShmNode->pShmMutex);

  37379.   if( flags & SQLITE_SHM_UNLOCK ){

  37380.     u16 allMask = 0; /* Mask of locks held by siblings */

  37381. 

  37382.     /* See if any siblings hold this same lock */

  37383.     for(pX=pShmNode->pFirst; pX; pX=pX->pNext){

  37384.       if( pX==p ) continue;

  37385.       assert( (pX->exclMask & (p->exclMask|p->sharedMask))==0 );

  37386.       allMask |= pX->sharedMask;

  37387.     }

  37388. 

  37389.     /* Unlock the system-level locks */

  37390.     if( (mask & allMask)==0 ){

  37391.       rc = unixShmSystemLock(pDbFd, F_UNLCK, ofst+UNIX_SHM_BASE, n);

  37392.     }else{

  37393.       rc = SQLITE_OK;

  37394.     }

  37395. 

  37396.     /* Undo the local locks */

  37397.     if( rc==SQLITE_OK ){

  37398.       p->exclMask &= ~mask;

  37399.       p->sharedMask &= ~mask;

  37400.     } 

  37401.   }else if( flags & SQLITE_SHM_SHARED ){

  37402.     u16 allShared = 0;  /* Union of locks held by connections other than "p" */

  37403. 

  37404.     /* Find out which shared locks are already held by sibling connections.

  37405.     ** If any sibling already holds an exclusive lock, go ahead and return

  37406.     ** SQLITE_BUSY.

  37407.     */

  37408.     for(pX=pShmNode->pFirst; pX; pX=pX->pNext){

  37409.       if( (pX->exclMask & mask)!=0 ){

  37410.         rc = SQLITE_BUSY;

  37411.         break;

  37412.       }

  37413.       allShared |= pX->sharedMask;

  37414.     }

  37415. 

  37416.     /* Get shared locks at the system level, if necessary */

  37417.     if( rc==SQLITE_OK ){

  37418.       if( (allShared & mask)==0 ){

  37419.         rc = unixShmSystemLock(pDbFd, F_RDLCK, ofst+UNIX_SHM_BASE, n);

  37420.       }else{

  37421.         rc = SQLITE_OK;

  37422.       }

  37423.     }

  37424. 

  37425.     /* Get the local shared locks */

  37426.     if( rc==SQLITE_OK ){

  37427.       p->sharedMask |= mask;

  37428.     }

  37429.   }else{

  37430.     /* Make sure no sibling connections hold locks that will block this

  37431.     ** lock.  If any do, return SQLITE_BUSY right away.

  37432.     */

  37433.     for(pX=pShmNode->pFirst; pX; pX=pX->pNext){

  37434.       if( (pX->exclMask & mask)!=0 || (pX->sharedMask & mask)!=0 ){

  37435.         rc = SQLITE_BUSY;

  37436.         break;

  37437.       }

  37438.     }

  37439.   

  37440.     /* Get the exclusive locks at the system level.  Then if successful

  37441.     ** also mark the local connection as being locked.

  37442.     */

  37443.     if( rc==SQLITE_OK ){

  37444.       rc = unixShmSystemLock(pDbFd, F_WRLCK, ofst+UNIX_SHM_BASE, n);

  37445.       if( rc==SQLITE_OK ){

  37446.         assert( (p->sharedMask & mask)==0 );

  37447.         p->exclMask |= mask;

  37448.       }

  37449.     }

  37450.   }

  37451.   sqlite3_mutex_leave(pShmNode->pShmMutex);

  37452.   OSTRACE(("SHM-LOCK shmid-%d, pid-%d got %03x,%03x\n",

  37453.            p->id, osGetpid(0), p->sharedMask, p->exclMask));

  37454.   return rc;

  37455. }

  37456. 

  37457. /*

  37458. ** Implement a memory barrier or memory fence on shared memory.  

  37459. **

  37460. ** All loads and stores begun before the barrier must complete before

  37461. ** any load or store begun after the barrier.

  37462. */

  37463. static void unixShmBarrier(

  37464.   sqlite3_file *fd                /* Database file holding the shared memory */

  37465. ){

  37466.   UNUSED_PARAMETER(fd);

  37467.   sqlite3MemoryBarrier();         /* compiler-defined memory barrier */

  37468.   assert( fd->pMethods->xLock==nolockLock 

  37469.        || unixFileMutexNotheld((unixFile*)fd) 

  37470.   );

  37471.   unixEnterMutex();               /* Also mutex, for redundancy */

  37472.   unixLeaveMutex();

  37473. }

  37474. 

  37475. /*

  37476. ** Close a connection to shared-memory.  Delete the underlying 

  37477. ** storage if deleteFlag is true.

  37478. **

  37479. ** If there is no shared memory associated with the connection then this

  37480. ** routine is a harmless no-op.

  37481. */

  37482. static int unixShmUnmap(

  37483.   sqlite3_file *fd,               /* The underlying database file */

  37484.   int deleteFlag                  /* Delete shared-memory if true */

  37485. ){

  37486.   unixShm *p;                     /* The connection to be closed */

  37487.   unixShmNode *pShmNode;          /* The underlying shared-memory file */

  37488.   unixShm **pp;                   /* For looping over sibling connections */

  37489.   unixFile *pDbFd;                /* The underlying database file */

  37490. 

  37491.   pDbFd = (unixFile*)fd;

  37492.   p = pDbFd->pShm;

  37493.   if( p==0 ) return SQLITE_OK;

  37494.   pShmNode = p->pShmNode;

  37495. 

  37496.   assert( pShmNode==pDbFd->pInode->pShmNode );

  37497.   assert( pShmNode->pInode==pDbFd->pInode );

  37498. 

  37499.   /* Remove connection p from the set of connections associated

  37500.   ** with pShmNode */

  37501.   sqlite3_mutex_enter(pShmNode->pShmMutex);

  37502.   for(pp=&pShmNode->pFirst; (*pp)!=p; pp = &(*pp)->pNext){}

  37503.   *pp = p->pNext;

  37504. 

  37505.   /* Free the connection p */

  37506.   sqlite3_free(p);

  37507.   pDbFd->pShm = 0;

  37508.   sqlite3_mutex_leave(pShmNode->pShmMutex);

  37509. 

  37510.   /* If pShmNode->nRef has reached 0, then close the underlying

  37511.   ** shared-memory file, too */

  37512.   assert( unixFileMutexNotheld(pDbFd) );

  37513.   unixEnterMutex();

  37514.   assert( pShmNode->nRef>0 );

  37515.   pShmNode->nRef--;

  37516.   if( pShmNode->nRef==0 ){

  37517.     if( deleteFlag && pShmNode->hShm>=0 ){

  37518.       osUnlink(pShmNode->zFilename);

  37519.     }

  37520.     unixShmPurge(pDbFd);

  37521.   }

  37522.   unixLeaveMutex();

  37523. 

  37524.   return SQLITE_OK;

  37525. }

  37526. 

  37527. 

  37528. #else

  37529. # define unixShmMap     0

  37530. # define unixShmLock    0

  37531. # define unixShmBarrier 0

  37532. # define unixShmUnmap   0

  37533. #endif /* #ifndef SQLITE_OMIT_WAL */

  37534. 

  37535. #if SQLITE_MAX_MMAP_SIZE>0

  37536. /*

  37537. ** If it is currently memory mapped, unmap file pFd.

  37538. */

  37539. static void unixUnmapfile(unixFile *pFd){

  37540.   assert( pFd->nFetchOut==0 );

  37541.   if( pFd->pMapRegion ){

  37542.     osMunmap(pFd->pMapRegion, pFd->mmapSizeActual);

  37543.     pFd->pMapRegion = 0;

  37544.     pFd->mmapSize = 0;

  37545.     pFd->mmapSizeActual = 0;

  37546.   }

  37547. }

  37548. 

  37549. /*

  37550. ** Attempt to set the size of the memory mapping maintained by file 

  37551. ** descriptor pFd to nNew bytes. Any existing mapping is discarded.

  37552. **

  37553. ** If successful, this function sets the following variables:

  37554. **

  37555. **       unixFile.pMapRegion

  37556. **       unixFile.mmapSize

  37557. **       unixFile.mmapSizeActual

  37558. **

  37559. ** If unsuccessful, an error message is logged via sqlite3_log() and

  37560. ** the three variables above are zeroed. In this case SQLite should

  37561. ** continue accessing the database using the xRead() and xWrite()

  37562. ** methods.

  37563. */

  37564. static void unixRemapfile(

  37565.   unixFile *pFd,                  /* File descriptor object */

  37566.   i64 nNew                        /* Required mapping size */

  37567. ){

  37568.   const char *zErr = "mmap";

  37569.   int h = pFd->h;                      /* File descriptor open on db file */

  37570.   u8 *pOrig = (u8 *)pFd->pMapRegion;   /* Pointer to current file mapping */

  37571.   i64 nOrig = pFd->mmapSizeActual;     /* Size of pOrig region in bytes */

  37572.   u8 *pNew = 0;                        /* Location of new mapping */

  37573.   int flags = PROT_READ;               /* Flags to pass to mmap() */

  37574. 

  37575.   assert( pFd->nFetchOut==0 );

  37576.   assert( nNew>pFd->mmapSize );

  37577.   assert( nNew<=pFd->mmapSizeMax );

  37578.   assert( nNew>0 );

  37579.   assert( pFd->mmapSizeActual>=pFd->mmapSize );

  37580.   assert( MAP_FAILED!=0 );

  37581. 

  37582. #ifdef SQLITE_MMAP_READWRITE

  37583.   if( (pFd->ctrlFlags & UNIXFILE_RDONLY)==0 ) flags |= PROT_WRITE;

  37584. #endif

  37585. 

  37586.   if( pOrig ){

  37587. #if HAVE_MREMAP

  37588.     i64 nReuse = pFd->mmapSize;

  37589. #else

  37590.     const int szSyspage = osGetpagesize();

  37591.     i64 nReuse = (pFd->mmapSize & ~(szSyspage-1));

  37592. #endif

  37593.     u8 *pReq = &pOrig[nReuse];

  37594. 

  37595.     /* Unmap any pages of the existing mapping that cannot be reused. */

  37596.     if( nReuse!=nOrig ){

  37597.       osMunmap(pReq, nOrig-nReuse);

  37598.     }

  37599. 

  37600. #if HAVE_MREMAP

  37601.     pNew = osMremap(pOrig, nReuse, nNew, MREMAP_MAYMOVE);

  37602.     zErr = "mremap";

  37603. #else

  37604.     pNew = osMmap(pReq, nNew-nReuse, flags, MAP_SHARED, h, nReuse);

  37605.     if( pNew!=MAP_FAILED ){

  37606.       if( pNew!=pReq ){

  37607.         osMunmap(pNew, nNew - nReuse);

  37608.         pNew = 0;

  37609.       }else{

  37610.         pNew = pOrig;

  37611.       }

  37612.     }

  37613. #endif

  37614. 

  37615.     /* The attempt to extend the existing mapping failed. Free it. */

  37616.     if( pNew==MAP_FAILED || pNew==0 ){

  37617.       osMunmap(pOrig, nReuse);

  37618.     }

  37619.   }

  37620. 

  37621.   /* If pNew is still NULL, try to create an entirely new mapping. */

  37622.   if( pNew==0 ){

  37623.     pNew = osMmap(0, nNew, flags, MAP_SHARED, h, 0);

  37624.   }

  37625. 

  37626.   if( pNew==MAP_FAILED ){

  37627.     pNew = 0;

  37628.     nNew = 0;

  37629.     unixLogError(SQLITE_OK, zErr, pFd->zPath);

  37630. 

  37631.     /* If the mmap() above failed, assume that all subsequent mmap() calls

  37632.     ** will probably fail too. Fall back to using xRead/xWrite exclusively

  37633.     ** in this case.  */

  37634.     pFd->mmapSizeMax = 0;

  37635.   }

  37636.   pFd->pMapRegion = (void *)pNew;

  37637.   pFd->mmapSize = pFd->mmapSizeActual = nNew;

  37638. }

  37639. 

  37640. /*

  37641. ** Memory map or remap the file opened by file-descriptor pFd (if the file

  37642. ** is already mapped, the existing mapping is replaced by the new). Or, if 

  37643. ** there already exists a mapping for this file, and there are still 

  37644. ** outstanding xFetch() references to it, this function is a no-op.

  37645. **

  37646. ** If parameter nByte is non-negative, then it is the requested size of 

  37647. ** the mapping to create. Otherwise, if nByte is less than zero, then the 

  37648. ** requested size is the size of the file on disk. The actual size of the

  37649. ** created mapping is either the requested size or the value configured 

  37650. ** using SQLITE_FCNTL_MMAP_LIMIT, whichever is smaller.

  37651. **

  37652. ** SQLITE_OK is returned if no error occurs (even if the mapping is not

  37653. ** recreated as a result of outstanding references) or an SQLite error

  37654. ** code otherwise.

  37655. */

  37656. static int unixMapfile(unixFile *pFd, i64 nMap){

  37657.   assert( nMap>=0 || pFd->nFetchOut==0 );

  37658.   assert( nMap>0 || (pFd->mmapSize==0 && pFd->pMapRegion==0) );

  37659.   if( pFd->nFetchOut>0 ) return SQLITE_OK;

  37660. 

  37661.   if( nMap<0 ){

  37662.     struct stat statbuf;          /* Low-level file information */

  37663.     if( osFstat(pFd->h, &statbuf) ){

  37664.       return SQLITE_IOERR_FSTAT;

  37665.     }

  37666.     nMap = statbuf.st_size;

  37667.   }

  37668.   if( nMap>pFd->mmapSizeMax ){

  37669.     nMap = pFd->mmapSizeMax;

  37670.   }

  37671. 

  37672.   assert( nMap>0 || (pFd->mmapSize==0 && pFd->pMapRegion==0) );

  37673.   if( nMap!=pFd->mmapSize ){

  37674.     unixRemapfile(pFd, nMap);

  37675.   }

  37676. 

  37677.   return SQLITE_OK;

  37678. }

  37679. #endif /* SQLITE_MAX_MMAP_SIZE>0 */

  37680. 

  37681. /*

  37682. ** If possible, return a pointer to a mapping of file fd starting at offset

  37683. ** iOff. The mapping must be valid for at least nAmt bytes.

  37684. **

  37685. ** If such a pointer can be obtained, store it in *pp and return SQLITE_OK.

  37686. ** Or, if one cannot but no error occurs, set *pp to 0 and return SQLITE_OK.

  37687. ** Finally, if an error does occur, return an SQLite error code. The final

  37688. ** value of *pp is undefined in this case.

  37689. **

  37690. ** If this function does return a pointer, the caller must eventually 

  37691. ** release the reference by calling unixUnfetch().

  37692. */

  37693. static int unixFetch(sqlite3_file *fd, i64 iOff, int nAmt, void **pp){

  37694. #if SQLITE_MAX_MMAP_SIZE>0

  37695.   unixFile *pFd = (unixFile *)fd;   /* The underlying database file */

  37696. #endif

  37697.   *pp = 0;

  37698. 

  37699. #if SQLITE_MAX_MMAP_SIZE>0

  37700.   if( pFd->mmapSizeMax>0 ){

  37701.     if( pFd->pMapRegion==0 ){

  37702.       int rc = unixMapfile(pFd, -1);

  37703.       if( rc!=SQLITE_OK ) return rc;

  37704.     }

  37705.     if( pFd->mmapSize >= iOff+nAmt ){

  37706.       *pp = &((u8 *)pFd->pMapRegion)[iOff];

  37707.       pFd->nFetchOut++;

  37708.     }

  37709.   }

  37710. #endif

  37711.   return SQLITE_OK;

  37712. }

  37713. 

  37714. /*

  37715. ** If the third argument is non-NULL, then this function releases a 

  37716. ** reference obtained by an earlier call to unixFetch(). The second

  37717. ** argument passed to this function must be the same as the corresponding

  37718. ** argument that was passed to the unixFetch() invocation. 

  37719. **

  37720. ** Or, if the third argument is NULL, then this function is being called 

  37721. ** to inform the VFS layer that, according to POSIX, any existing mapping 

  37722. ** may now be invalid and should be unmapped.

  37723. */

  37724. static int unixUnfetch(sqlite3_file *fd, i64 iOff, void *p){

  37725. #if SQLITE_MAX_MMAP_SIZE>0

  37726.   unixFile *pFd = (unixFile *)fd;   /* The underlying database file */

  37727.   UNUSED_PARAMETER(iOff);

  37728. 

  37729.   /* If p==0 (unmap the entire file) then there must be no outstanding 

  37730.   ** xFetch references. Or, if p!=0 (meaning it is an xFetch reference),

  37731.   ** then there must be at least one outstanding.  */

  37732.   assert( (p==0)==(pFd->nFetchOut==0) );

  37733. 

  37734.   /* If p!=0, it must match the iOff value. */

  37735.   assert( p==0 || p==&((u8 *)pFd->pMapRegion)[iOff] );

  37736. 

  37737.   if( p ){

  37738.     pFd->nFetchOut--;

  37739.   }else{

  37740.     unixUnmapfile(pFd);

  37741.   }

  37742. 

  37743.   assert( pFd->nFetchOut>=0 );

  37744. #else

  37745.   UNUSED_PARAMETER(fd);

  37746.   UNUSED_PARAMETER(p);

  37747.   UNUSED_PARAMETER(iOff);

  37748. #endif

  37749.   return SQLITE_OK;

  37750. }

  37751. 

  37752. /*

  37753. ** Here ends the implementation of all sqlite3_file methods.

  37754. **

  37755. ********************** End sqlite3_file Methods *******************************

  37756. ******************************************************************************/

  37757. 

  37758. /*

  37759. ** This division contains definitions of sqlite3_io_methods objects that

  37760. ** implement various file locking strategies.  It also contains definitions

  37761. ** of "finder" functions.  A finder-function is used to locate the appropriate

  37762. ** sqlite3_io_methods object for a particular database file.  The pAppData

  37763. ** field of the sqlite3_vfs VFS objects are initialized to be pointers to

  37764. ** the correct finder-function for that VFS.

  37765. **

  37766. ** Most finder functions return a pointer to a fixed sqlite3_io_methods

  37767. ** object.  The only interesting finder-function is autolockIoFinder, which

  37768. ** looks at the filesystem type and tries to guess the best locking

  37769. ** strategy from that.

  37770. **

  37771. ** For finder-function F, two objects are created:

  37772. **

  37773. **    (1) The real finder-function named "FImpt()".

  37774. **

  37775. **    (2) A constant pointer to this function named just "F".

  37776. **

  37777. **

  37778. ** A pointer to the F pointer is used as the pAppData value for VFS

  37779. ** objects.  We have to do this instead of letting pAppData point

  37780. ** directly at the finder-function since C90 rules prevent a void*

  37781. ** from be cast into a function pointer.

  37782. **

  37783. **

  37784. ** Each instance of this macro generates two objects:

  37785. **

  37786. **   *  A constant sqlite3_io_methods object call METHOD that has locking

  37787. **      methods CLOSE, LOCK, UNLOCK, CKRESLOCK.

  37788. **

  37789. **   *  An I/O method finder function called FINDER that returns a pointer

  37790. **      to the METHOD object in the previous bullet.

  37791. */

  37792. #define IOMETHODS(FINDER,METHOD,VERSION,CLOSE,LOCK,UNLOCK,CKLOCK,SHMMAP)     \

  37793. static const sqlite3_io_methods METHOD = {                                   \

  37794.    VERSION,                    /* iVersion */                                \

  37795.    CLOSE,                      /* xClose */                                  \

  37796.    unixRead,                   /* xRead */                                   \

  37797.    unixWrite,                  /* xWrite */                                  \

  37798.    unixTruncate,               /* xTruncate */                               \

  37799.    unixSync,                   /* xSync */                                   \

  37800.    unixFileSize,               /* xFileSize */                               \

  37801.    LOCK,                       /* xLock */                                   \

  37802.    UNLOCK,                     /* xUnlock */                                 \

  37803.    CKLOCK,                     /* xCheckReservedLock */                      \

  37804.    unixFileControl,            /* xFileControl */                            \

  37805.    unixSectorSize,             /* xSectorSize */                             \

  37806.    unixDeviceCharacteristics,  /* xDeviceCapabilities */                     \

  37807.    SHMMAP,                     /* xShmMap */                                 \

  37808.    unixShmLock,                /* xShmLock */                                \

  37809.    unixShmBarrier,             /* xShmBarrier */                             \

  37810.    unixShmUnmap,               /* xShmUnmap */                               \

  37811.    unixFetch,                  /* xFetch */                                  \

  37812.    unixUnfetch,                /* xUnfetch */                                \

  37813. };                                                                           \

  37814. static const sqlite3_io_methods *FINDER##Impl(const char *z, unixFile *p){   \

  37815.   UNUSED_PARAMETER(z); UNUSED_PARAMETER(p);                                  \

  37816.   return &METHOD;                                                            \

  37817. }                                                                            \

  37818. static const sqlite3_io_methods *(*const FINDER)(const char*,unixFile *p)    \

  37819.     = FINDER##Impl;

  37820. 

  37821. /*

  37822. ** Here are all of the sqlite3_io_methods objects for each of the

  37823. ** locking strategies.  Functions that return pointers to these methods

  37824. ** are also created.

  37825. */

  37826. IOMETHODS(

  37827.   posixIoFinder,            /* Finder function name */

  37828.   posixIoMethods,           /* sqlite3_io_methods object name */

  37829.   3,                        /* shared memory and mmap are enabled */

  37830.   unixClose,                /* xClose method */

  37831.   unixLock,                 /* xLock method */

  37832.   unixUnlock,               /* xUnlock method */

  37833.   unixCheckReservedLock,    /* xCheckReservedLock method */

  37834.   unixShmMap                /* xShmMap method */

  37835. )

  37836. IOMETHODS(

  37837.   nolockIoFinder,           /* Finder function name */

  37838.   nolockIoMethods,          /* sqlite3_io_methods object name */

  37839.   3,                        /* shared memory and mmap are enabled */

  37840.   nolockClose,              /* xClose method */

  37841.   nolockLock,               /* xLock method */

  37842.   nolockUnlock,             /* xUnlock method */

  37843.   nolockCheckReservedLock,  /* xCheckReservedLock method */

  37844.   0                         /* xShmMap method */

  37845. )

  37846. IOMETHODS(

  37847.   dotlockIoFinder,          /* Finder function name */

  37848.   dotlockIoMethods,         /* sqlite3_io_methods object name */

  37849.   1,                        /* shared memory is disabled */

  37850.   dotlockClose,             /* xClose method */

  37851.   dotlockLock,              /* xLock method */

  37852.   dotlockUnlock,            /* xUnlock method */

  37853.   dotlockCheckReservedLock, /* xCheckReservedLock method */

  37854.   0                         /* xShmMap method */

  37855. )

  37856. 

  37857. #if SQLITE_ENABLE_LOCKING_STYLE

  37858. IOMETHODS(

  37859.   flockIoFinder,            /* Finder function name */

  37860.   flockIoMethods,           /* sqlite3_io_methods object name */

  37861.   1,                        /* shared memory is disabled */

  37862.   flockClose,               /* xClose method */

  37863.   flockLock,                /* xLock method */

  37864.   flockUnlock,              /* xUnlock method */

  37865.   flockCheckReservedLock,   /* xCheckReservedLock method */

  37866.   0                         /* xShmMap method */

  37867. )

  37868. #endif

  37869. 

  37870. #if OS_VXWORKS

  37871. IOMETHODS(

  37872.   semIoFinder,              /* Finder function name */

  37873.   semIoMethods,             /* sqlite3_io_methods object name */

  37874.   1,                        /* shared memory is disabled */

  37875.   semXClose,                /* xClose method */

  37876.   semXLock,                 /* xLock method */

  37877.   semXUnlock,               /* xUnlock method */

  37878.   semXCheckReservedLock,    /* xCheckReservedLock method */

  37879.   0                         /* xShmMap method */

  37880. )

  37881. #endif

  37882. 

  37883. #if defined(__APPLE__) && SQLITE_ENABLE_LOCKING_STYLE

  37884. IOMETHODS(

  37885.   afpIoFinder,              /* Finder function name */

  37886.   afpIoMethods,             /* sqlite3_io_methods object name */

  37887.   1,                        /* shared memory is disabled */

  37888.   afpClose,                 /* xClose method */

  37889.   afpLock,                  /* xLock method */

  37890.   afpUnlock,                /* xUnlock method */

  37891.   afpCheckReservedLock,     /* xCheckReservedLock method */

  37892.   0                         /* xShmMap method */

  37893. )

  37894. #endif

  37895. 

  37896. /*

  37897. ** The proxy locking method is a "super-method" in the sense that it

  37898. ** opens secondary file descriptors for the conch and lock files and

  37899. ** it uses proxy, dot-file, AFP, and flock() locking methods on those

  37900. ** secondary files.  For this reason, the division that implements

  37901. ** proxy locking is located much further down in the file.  But we need

  37902. ** to go ahead and define the sqlite3_io_methods and finder function

  37903. ** for proxy locking here.  So we forward declare the I/O methods.

  37904. */

  37905. #if defined(__APPLE__) && SQLITE_ENABLE_LOCKING_STYLE

  37906. static int proxyClose(sqlite3_file*);

  37907. static int proxyLock(sqlite3_file*, int);

  37908. static int proxyUnlock(sqlite3_file*, int);

  37909. static int proxyCheckReservedLock(sqlite3_file*, int*);

  37910. IOMETHODS(

  37911.   proxyIoFinder,            /* Finder function name */

  37912.   proxyIoMethods,           /* sqlite3_io_methods object name */

  37913.   1,                        /* shared memory is disabled */

  37914.   proxyClose,               /* xClose method */

  37915.   proxyLock,                /* xLock method */

  37916.   proxyUnlock,              /* xUnlock method */

  37917.   proxyCheckReservedLock,   /* xCheckReservedLock method */

  37918.   0                         /* xShmMap method */

  37919. )

  37920. #endif

  37921. 

  37922. /* nfs lockd on OSX 10.3+ doesn't clear write locks when a read lock is set */

  37923. #if defined(__APPLE__) && SQLITE_ENABLE_LOCKING_STYLE

  37924. IOMETHODS(

  37925.   nfsIoFinder,               /* Finder function name */

  37926.   nfsIoMethods,              /* sqlite3_io_methods object name */

  37927.   1,                         /* shared memory is disabled */

  37928.   unixClose,                 /* xClose method */

  37929.   unixLock,                  /* xLock method */

  37930.   nfsUnlock,                 /* xUnlock method */

  37931.   unixCheckReservedLock,     /* xCheckReservedLock method */

  37932.   0                          /* xShmMap method */

  37933. )

  37934. #endif

  37935. 

  37936. #if defined(__APPLE__) && SQLITE_ENABLE_LOCKING_STYLE

  37937. /* 

  37938. ** This "finder" function attempts to determine the best locking strategy 

  37939. ** for the database file "filePath".  It then returns the sqlite3_io_methods

  37940. ** object that implements that strategy.

  37941. **

  37942. ** This is for MacOSX only.

  37943. */

  37944. static const sqlite3_io_methods *autolockIoFinderImpl(

  37945.   const char *filePath,    /* name of the database file */

  37946.   unixFile *pNew           /* open file object for the database file */

  37947. ){

  37948.   static const struct Mapping {

  37949.     const char *zFilesystem;              /* Filesystem type name */

  37950.     const sqlite3_io_methods *pMethods;   /* Appropriate locking method */

  37951.   } aMap[] = {

  37952.     { "hfs",    &posixIoMethods },

  37953.     { "ufs",    &posixIoMethods },

  37954.     { "afpfs",  &afpIoMethods },

  37955.     { "smbfs",  &afpIoMethods },

  37956.     { "webdav", &nolockIoMethods },

  37957.     { 0, 0 }

  37958.   };

  37959.   int i;

  37960.   struct statfs fsInfo;

  37961.   struct flock lockInfo;

  37962. 

  37963.   if( !filePath ){

  37964.     /* If filePath==NULL that means we are dealing with a transient file

  37965.     ** that does not need to be locked. */

  37966.     return &nolockIoMethods;

  37967.   }

  37968.   if( statfs(filePath, &fsInfo) != -1 ){

  37969.     if( fsInfo.f_flags & MNT_RDONLY ){

  37970.       return &nolockIoMethods;

  37971.     }

  37972.     for(i=0; aMap[i].zFilesystem; i++){

  37973.       if( strcmp(fsInfo.f_fstypename, aMap[i].zFilesystem)==0 ){

  37974.         return aMap[i].pMethods;

  37975.       }

  37976.     }

  37977.   }

  37978. 

  37979.   /* Default case. Handles, amongst others, "nfs".

  37980.   ** Test byte-range lock using fcntl(). If the call succeeds, 

  37981.   ** assume that the file-system supports POSIX style locks. 

  37982.   */

  37983.   lockInfo.l_len = 1;

  37984.   lockInfo.l_start = 0;

  37985.   lockInfo.l_whence = SEEK_SET;

  37986.   lockInfo.l_type = F_RDLCK;

  37987.   if( osFcntl(pNew->h, F_GETLK, &lockInfo)!=-1 ) {

  37988.     if( strcmp(fsInfo.f_fstypename, "nfs")==0 ){

  37989.       return &nfsIoMethods;

  37990.     } else {

  37991.       return &posixIoMethods;

  37992.     }

  37993.   }else{

  37994.     return &dotlockIoMethods;

  37995.   }

  37996. }

  37997. static const sqlite3_io_methods 

  37998.   *(*const autolockIoFinder)(const char*,unixFile*) = autolockIoFinderImpl;

  37999. 

  38000. #endif /* defined(__APPLE__) && SQLITE_ENABLE_LOCKING_STYLE */

  38001. 

  38002. #if OS_VXWORKS

  38003. /*

  38004. ** This "finder" function for VxWorks checks to see if posix advisory

  38005. ** locking works.  If it does, then that is what is used.  If it does not

  38006. ** work, then fallback to named semaphore locking.

  38007. */

  38008. static const sqlite3_io_methods *vxworksIoFinderImpl(

  38009.   const char *filePath,    /* name of the database file */

  38010.   unixFile *pNew           /* the open file object */

  38011. ){

  38012.   struct flock lockInfo;

  38013. 

  38014.   if( !filePath ){

  38015.     /* If filePath==NULL that means we are dealing with a transient file

  38016.     ** that does not need to be locked. */

  38017.     return &nolockIoMethods;

  38018.   }

  38019. 

  38020.   /* Test if fcntl() is supported and use POSIX style locks.

  38021.   ** Otherwise fall back to the named semaphore method.

  38022.   */

  38023.   lockInfo.l_len = 1;

  38024.   lockInfo.l_start = 0;

  38025.   lockInfo.l_whence = SEEK_SET;

  38026.   lockInfo.l_type = F_RDLCK;

  38027.   if( osFcntl(pNew->h, F_GETLK, &lockInfo)!=-1 ) {

  38028.     return &posixIoMethods;

  38029.   }else{

  38030.     return &semIoMethods;

  38031.   }

  38032. }

  38033. static const sqlite3_io_methods 

  38034.   *(*const vxworksIoFinder)(const char*,unixFile*) = vxworksIoFinderImpl;

  38035. 

  38036. #endif /* OS_VXWORKS */

  38037. 

  38038. /*

  38039. ** An abstract type for a pointer to an IO method finder function:

  38040. */

  38041. typedef const sqlite3_io_methods *(*finder_type)(const char*,unixFile*);

  38042. 

  38043. 

  38044. /****************************************************************************

  38045. **************************** sqlite3_vfs methods ****************************

  38046. **

  38047. ** This division contains the implementation of methods on the

  38048. ** sqlite3_vfs object.

  38049. */

  38050. 

  38051. /*

  38052. ** Initialize the contents of the unixFile structure pointed to by pId.

  38053. */

  38054. static int fillInUnixFile(

  38055.   sqlite3_vfs *pVfs,      /* Pointer to vfs object */

  38056.   int h,                  /* Open file descriptor of file being opened */

  38057.   sqlite3_file *pId,      /* Write to the unixFile structure here */

  38058.   const char *zFilename,  /* Name of the file being opened */

  38059.   int ctrlFlags           /* Zero or more UNIXFILE_* values */

  38060. ){

  38061.   const sqlite3_io_methods *pLockingStyle;

  38062.   unixFile *pNew = (unixFile *)pId;

  38063.   int rc = SQLITE_OK;

  38064. 

  38065.   assert( pNew->pInode==NULL );

  38066. 

  38067.   /* No locking occurs in temporary files */

  38068.   assert( zFilename!=0 || (ctrlFlags & UNIXFILE_NOLOCK)!=0 );

  38069. 

  38070.   OSTRACE(("OPEN    %-3d %s\n", h, zFilename));

  38071.   pNew->h = h;

  38072.   pNew->pVfs = pVfs;

  38073.   pNew->zPath = zFilename;

  38074.   pNew->ctrlFlags = (u8)ctrlFlags;

  38075. #if SQLITE_MAX_MMAP_SIZE>0

  38076.   pNew->mmapSizeMax = sqlite3GlobalConfig.szMmap;

  38077. #endif

  38078.   if( sqlite3_uri_boolean(((ctrlFlags & UNIXFILE_URI) ? zFilename : 0),

  38079.                            "psow", SQLITE_POWERSAFE_OVERWRITE) ){

  38080.     pNew->ctrlFlags |= UNIXFILE_PSOW;

  38081.   }

  38082.   if( strcmp(pVfs->zName,"unix-excl")==0 ){

  38083.     pNew->ctrlFlags |= UNIXFILE_EXCL;

  38084.   }

  38085. 

  38086. #if OS_VXWORKS

  38087.   pNew->pId = vxworksFindFileId(zFilename);

  38088.   if( pNew->pId==0 ){

  38089.     ctrlFlags |= UNIXFILE_NOLOCK;

  38090.     rc = SQLITE_NOMEM_BKPT;

  38091.   }

  38092. #endif

  38093. 

  38094.   if( ctrlFlags & UNIXFILE_NOLOCK ){

  38095.     pLockingStyle = &nolockIoMethods;

  38096.   }else{

  38097.     pLockingStyle = (**(finder_type*)pVfs->pAppData)(zFilename, pNew);

  38098. #if SQLITE_ENABLE_LOCKING_STYLE

  38099.     /* Cache zFilename in the locking context (AFP and dotlock override) for

  38100.     ** proxyLock activation is possible (remote proxy is based on db name)

  38101.     ** zFilename remains valid until file is closed, to support */

  38102.     pNew->lockingContext = (void*)zFilename;

  38103. #endif

  38104.   }

  38105. 

  38106.   if( pLockingStyle == &posixIoMethods

  38107. #if defined(__APPLE__) && SQLITE_ENABLE_LOCKING_STYLE

  38108.     || pLockingStyle == &nfsIoMethods

  38109. #endif

  38110.   ){

  38111.     unixEnterMutex();

  38112.     rc = findInodeInfo(pNew, &pNew->pInode);

  38113.     if( rc!=SQLITE_OK ){

  38114.       /* If an error occurred in findInodeInfo(), close the file descriptor

  38115.       ** immediately, before releasing the mutex. findInodeInfo() may fail

  38116.       ** in two scenarios:

  38117.       **

  38118.       **   (a) A call to fstat() failed.

  38119.       **   (b) A malloc failed.

  38120.       **

  38121.       ** Scenario (b) may only occur if the process is holding no other

  38122.       ** file descriptors open on the same file. If there were other file

  38123.       ** descriptors on this file, then no malloc would be required by

  38124.       ** findInodeInfo(). If this is the case, it is quite safe to close

  38125.       ** handle h - as it is guaranteed that no posix locks will be released

  38126.       ** by doing so.

  38127.       **

  38128.       ** If scenario (a) caused the error then things are not so safe. The

  38129.       ** implicit assumption here is that if fstat() fails, things are in

  38130.       ** such bad shape that dropping a lock or two doesn't matter much.

  38131.       */

  38132.       robust_close(pNew, h, __LINE__);

  38133.       h = -1;

  38134.     }

  38135.     unixLeaveMutex();

  38136.   }

  38137. 

  38138. #if SQLITE_ENABLE_LOCKING_STYLE && defined(__APPLE__)

  38139.   else if( pLockingStyle == &afpIoMethods ){

  38140.     /* AFP locking uses the file path so it needs to be included in

  38141.     ** the afpLockingContext.

  38142.     */

  38143.     afpLockingContext *pCtx;

  38144.     pNew->lockingContext = pCtx = sqlite3_malloc64( sizeof(*pCtx) );

  38145.     if( pCtx==0 ){

  38146.       rc = SQLITE_NOMEM_BKPT;

  38147.     }else{

  38148.       /* NB: zFilename exists and remains valid until the file is closed

  38149.       ** according to requirement F11141.  So we do not need to make a

  38150.       ** copy of the filename. */

  38151.       pCtx->dbPath = zFilename;

  38152.       pCtx->reserved = 0;

  38153.       srandomdev();

  38154.       unixEnterMutex();

  38155.       rc = findInodeInfo(pNew, &pNew->pInode);

  38156.       if( rc!=SQLITE_OK ){

  38157.         sqlite3_free(pNew->lockingContext);

  38158.         robust_close(pNew, h, __LINE__);

  38159.         h = -1;

  38160.       }

  38161.       unixLeaveMutex();        

  38162.     }

  38163.   }

  38164. #endif

  38165. 

  38166.   else if( pLockingStyle == &dotlockIoMethods ){

  38167.     /* Dotfile locking uses the file path so it needs to be included in

  38168.     ** the dotlockLockingContext 

  38169.     */

  38170.     char *zLockFile;

  38171.     int nFilename;

  38172.     assert( zFilename!=0 );

  38173.     nFilename = (int)strlen(zFilename) + 6;

  38174.     zLockFile = (char *)sqlite3_malloc64(nFilename);

  38175.     if( zLockFile==0 ){

  38176.       rc = SQLITE_NOMEM_BKPT;

  38177.     }else{

  38178.       sqlite3_snprintf(nFilename, zLockFile, "%s" DOTLOCK_SUFFIX, zFilename);

  38179.     }

  38180.     pNew->lockingContext = zLockFile;

  38181.   }

  38182. 

  38183. #if OS_VXWORKS

  38184.   else if( pLockingStyle == &semIoMethods ){

  38185.     /* Named semaphore locking uses the file path so it needs to be

  38186.     ** included in the semLockingContext

  38187.     */

  38188.     unixEnterMutex();

  38189.     rc = findInodeInfo(pNew, &pNew->pInode);

  38190.     if( (rc==SQLITE_OK) && (pNew->pInode->pSem==NULL) ){

  38191.       char *zSemName = pNew->pInode->aSemName;

  38192.       int n;

  38193.       sqlite3_snprintf(MAX_PATHNAME, zSemName, "/%s.sem",

  38194.                        pNew->pId->zCanonicalName);

  38195.       for( n=1; zSemName[n]; n++ )

  38196.         if( zSemName[n]=='/' ) zSemName[n] = '_';

  38197.       pNew->pInode->pSem = sem_open(zSemName, O_CREAT, 0666, 1);

  38198.       if( pNew->pInode->pSem == SEM_FAILED ){

  38199.         rc = SQLITE_NOMEM_BKPT;

  38200.         pNew->pInode->aSemName[0] = '\0';

  38201.       }

  38202.     }

  38203.     unixLeaveMutex();

  38204.   }

  38205. #endif

  38206.   

  38207.   storeLastErrno(pNew, 0);

  38208. #if OS_VXWORKS

  38209.   if( rc!=SQLITE_OK ){

  38210.     if( h>=0 ) robust_close(pNew, h, __LINE__);

  38211.     h = -1;

  38212.     osUnlink(zFilename);

  38213.     pNew->ctrlFlags |= UNIXFILE_DELETE;

  38214.   }

  38215. #endif

  38216.   if( rc!=SQLITE_OK ){

  38217.     if( h>=0 ) robust_close(pNew, h, __LINE__);

  38218.   }else{

  38219.     pNew->pMethod = pLockingStyle;

  38220.     OpenCounter(+1);

  38221.     verifyDbFile(pNew);

  38222.   }

  38223.   return rc;

  38224. }

  38225. 

  38226. /*

  38227. ** Return the name of a directory in which to put temporary files.

  38228. ** If no suitable temporary file directory can be found, return NULL.

  38229. */

  38230. static const char *unixTempFileDir(void){

  38231.   static const char *azDirs[] = {

  38232.      0,

  38233.      0,

  38234.      "/var/tmp",

  38235.      "/usr/tmp",

  38236.      "/tmp",

  38237.      "."

  38238.   };

  38239.   unsigned int i = 0;

  38240.   struct stat buf;

  38241.   const char *zDir = sqlite3_temp_directory;

  38242. 

  38243.   if( !azDirs[0] ) azDirs[0] = getenv("SQLITE_TMPDIR");

  38244.   if( !azDirs[1] ) azDirs[1] = getenv("TMPDIR");

  38245.   while(1){

  38246.     if( zDir!=0

  38247.      && osStat(zDir, &buf)==0

  38248.      && S_ISDIR(buf.st_mode)

  38249.      && osAccess(zDir, 03)==0

  38250.     ){

  38251.       return zDir;

  38252.     }

  38253.     if( i>=sizeof(azDirs)/sizeof(azDirs[0]) ) break;

  38254.     zDir = azDirs[i++];

  38255.   }

  38256.   return 0;

  38257. }

  38258. 

  38259. /*

  38260. ** Create a temporary file name in zBuf.  zBuf must be allocated

  38261. ** by the calling process and must be big enough to hold at least

  38262. ** pVfs->mxPathname bytes.

  38263. */

  38264. static int unixGetTempname(int nBuf, char *zBuf){

  38265.   const char *zDir;

  38266.   int iLimit = 0;

  38267. 

  38268.   /* It's odd to simulate an io-error here, but really this is just

  38269.   ** using the io-error infrastructure to test that SQLite handles this

  38270.   ** function failing. 

  38271.   */

  38272.   zBuf[0] = 0;

  38273.   SimulateIOError( return SQLITE_IOERR );

  38274. 

  38275.   zDir = unixTempFileDir();

  38276.   if( zDir==0 ) return SQLITE_IOERR_GETTEMPPATH;

  38277.   do{

  38278.     u64 r;

  38279.     sqlite3_randomness(sizeof(r), &r);

  38280.     assert( nBuf>2 );

  38281.     zBuf[nBuf-2] = 0;

  38282.     sqlite3_snprintf(nBuf, zBuf, "%s/"SQLITE_TEMP_FILE_PREFIX"%llx%c",

  38283.                      zDir, r, 0);

  38284.     if( zBuf[nBuf-2]!=0 || (iLimit++)>10 ) return SQLITE_ERROR;

  38285.   }while( osAccess(zBuf,0)==0 );

  38286.   return SQLITE_OK;

  38287. }

  38288. 

  38289. #if SQLITE_ENABLE_LOCKING_STYLE && defined(__APPLE__)

  38290. /*

  38291. ** Routine to transform a unixFile into a proxy-locking unixFile.

  38292. ** Implementation in the proxy-lock division, but used by unixOpen()

  38293. ** if SQLITE_PREFER_PROXY_LOCKING is defined.

  38294. */

  38295. static int proxyTransformUnixFile(unixFile*, const char*);

  38296. #endif

  38297. 

  38298. /*

  38299. ** Search for an unused file descriptor that was opened on the database 

  38300. ** file (not a journal or master-journal file) identified by pathname

  38301. ** zPath with SQLITE_OPEN_XXX flags matching those passed as the second

  38302. ** argument to this function.

  38303. **

  38304. ** Such a file descriptor may exist if a database connection was closed

  38305. ** but the associated file descriptor could not be closed because some

  38306. ** other file descriptor open on the same file is holding a file-lock.

  38307. ** Refer to comments in the unixClose() function and the lengthy comment

  38308. ** describing "Posix Advisory Locking" at the start of this file for 

  38309. ** further details. Also, ticket #4018.

  38310. **

  38311. ** If a suitable file descriptor is found, then it is returned. If no

  38312. ** such file descriptor is located, -1 is returned.

  38313. */

  38314. static UnixUnusedFd *findReusableFd(const char *zPath, int flags){

  38315.   UnixUnusedFd *pUnused = 0;

  38316. 

  38317.   /* Do not search for an unused file descriptor on vxworks. Not because

  38318.   ** vxworks would not benefit from the change (it might, we're not sure),

  38319.   ** but because no way to test it is currently available. It is better 

  38320.   ** not to risk breaking vxworks support for the sake of such an obscure 

  38321.   ** feature.  */

  38322. #if !OS_VXWORKS

  38323.   struct stat sStat;                   /* Results of stat() call */

  38324. 

  38325.   unixEnterMutex();

  38326. 

  38327.   /* A stat() call may fail for various reasons. If this happens, it is

  38328.   ** almost certain that an open() call on the same path will also fail.

  38329.   ** For this reason, if an error occurs in the stat() call here, it is

  38330.   ** ignored and -1 is returned. The caller will try to open a new file

  38331.   ** descriptor on the same path, fail, and return an error to SQLite.

  38332.   **

  38333.   ** Even if a subsequent open() call does succeed, the consequences of

  38334.   ** not searching for a reusable file descriptor are not dire.  */

  38335.   if( inodeList!=0 && 0==osStat(zPath, &sStat) ){

  38336.     unixInodeInfo *pInode;

  38337. 

  38338.     pInode = inodeList;

  38339.     while( pInode && (pInode->fileId.dev!=sStat.st_dev

  38340.                      || pInode->fileId.ino!=(u64)sStat.st_ino) ){

  38341.        pInode = pInode->pNext;

  38342.     }

  38343.     if( pInode ){

  38344.       UnixUnusedFd **pp;

  38345.       assert( sqlite3_mutex_notheld(pInode->pLockMutex) );

  38346.       sqlite3_mutex_enter(pInode->pLockMutex);

  38347.       for(pp=&pInode->pUnused; *pp && (*pp)->flags!=flags; pp=&((*pp)->pNext));

  38348.       pUnused = *pp;

  38349.       if( pUnused ){

  38350.         *pp = pUnused->pNext;

  38351.       }

  38352.       sqlite3_mutex_leave(pInode->pLockMutex);

  38353.     }

  38354.   }

  38355.   unixLeaveMutex();

  38356. #endif    /* if !OS_VXWORKS */

  38357.   return pUnused;

  38358. }

  38359. 

  38360. /*

  38361. ** Find the mode, uid and gid of file zFile. 

  38362. */

  38363. static int getFileMode(

  38364.   const char *zFile,              /* File name */

  38365.   mode_t *pMode,                  /* OUT: Permissions of zFile */

  38366.   uid_t *pUid,                    /* OUT: uid of zFile. */

  38367.   gid_t *pGid                     /* OUT: gid of zFile. */

  38368. ){

  38369.   struct stat sStat;              /* Output of stat() on database file */

  38370.   int rc = SQLITE_OK;

  38371.   if( 0==osStat(zFile, &sStat) ){

  38372.     *pMode = sStat.st_mode & 0777;

  38373.     *pUid = sStat.st_uid;

  38374.     *pGid = sStat.st_gid;

  38375.   }else{

  38376.     rc = SQLITE_IOERR_FSTAT;

  38377.   }

  38378.   return rc;

  38379. }

  38380. 

  38381. /*

  38382. ** This function is called by unixOpen() to determine the unix permissions

  38383. ** to create new files with. If no error occurs, then SQLITE_OK is returned

  38384. ** and a value suitable for passing as the third argument to open(2) is

  38385. ** written to *pMode. If an IO error occurs, an SQLite error code is 

  38386. ** returned and the value of *pMode is not modified.

  38387. **

  38388. ** In most cases, this routine sets *pMode to 0, which will become

  38389. ** an indication to robust_open() to create the file using

  38390. ** SQLITE_DEFAULT_FILE_PERMISSIONS adjusted by the umask.

  38391. ** But if the file being opened is a WAL or regular journal file, then 

  38392. ** this function queries the file-system for the permissions on the 

  38393. ** corresponding database file and sets *pMode to this value. Whenever 

  38394. ** possible, WAL and journal files are created using the same permissions 

  38395. ** as the associated database file.

  38396. **

  38397. ** If the SQLITE_ENABLE_8_3_NAMES option is enabled, then the

  38398. ** original filename is unavailable.  But 8_3_NAMES is only used for

  38399. ** FAT filesystems and permissions do not matter there, so just use

  38400. ** the default permissions.

  38401. */

  38402. static int findCreateFileMode(

  38403.   const char *zPath,              /* Path of file (possibly) being created */

  38404.   int flags,                      /* Flags passed as 4th argument to xOpen() */

  38405.   mode_t *pMode,                  /* OUT: Permissions to open file with */

  38406.   uid_t *pUid,                    /* OUT: uid to set on the file */

  38407.   gid_t *pGid                     /* OUT: gid to set on the file */

  38408. ){

  38409.   int rc = SQLITE_OK;             /* Return Code */

  38410.   *pMode = 0;

  38411.   *pUid = 0;

  38412.   *pGid = 0;

  38413.   if( flags & (SQLITE_OPEN_WAL|SQLITE_OPEN_MAIN_JOURNAL) ){

  38414.     char zDb[MAX_PATHNAME+1];     /* Database file path */

  38415.     int nDb;                      /* Number of valid bytes in zDb */

  38416. 

  38417.     /* zPath is a path to a WAL or journal file. The following block derives

  38418.     ** the path to the associated database file from zPath. This block handles

  38419.     ** the following naming conventions:

  38420.     **

  38421.     **   "<path to db>-journal"

  38422.     **   "<path to db>-wal"

  38423.     **   "<path to db>-journalNN"

  38424.     **   "<path to db>-walNN"

  38425.     **

  38426.     ** where NN is a decimal number. The NN naming schemes are 

  38427.     ** used by the test_multiplex.c module.

  38428.     */

  38429.     nDb = sqlite3Strlen30(zPath) - 1; 

  38430.     while( zPath[nDb]!='-' ){

  38431.       /* In normal operation, the journal file name will always contain

  38432.       ** a '-' character.  However in 8+3 filename mode, or if a corrupt

  38433.       ** rollback journal specifies a master journal with a goofy name, then

  38434.       ** the '-' might be missing. */

  38435.       if( nDb==0 || zPath[nDb]=='.' ) return SQLITE_OK;

  38436.       nDb--;

  38437.     }

  38438.     memcpy(zDb, zPath, nDb);

  38439.     zDb[nDb] = '\0';

  38440. 

  38441.     rc = getFileMode(zDb, pMode, pUid, pGid);

  38442.   }else if( flags & SQLITE_OPEN_DELETEONCLOSE ){

  38443.     *pMode = 0600;

  38444.   }else if( flags & SQLITE_OPEN_URI ){

  38445.     /* If this is a main database file and the file was opened using a URI

  38446.     ** filename, check for the "modeof" parameter. If present, interpret

  38447.     ** its value as a filename and try to copy the mode, uid and gid from

  38448.     ** that file.  */

  38449.     const char *z = sqlite3_uri_parameter(zPath, "modeof");

  38450.     if( z ){

  38451.       rc = getFileMode(z, pMode, pUid, pGid);

  38452.     }

  38453.   }

  38454.   return rc;

  38455. }

  38456. 

  38457. /*

  38458. ** Open the file zPath.

  38459. ** 

  38460. ** Previously, the SQLite OS layer used three functions in place of this

  38461. ** one:

  38462. **

  38463. **     sqlite3OsOpenReadWrite();

  38464. **     sqlite3OsOpenReadOnly();

  38465. **     sqlite3OsOpenExclusive();

  38466. **

  38467. ** These calls correspond to the following combinations of flags:

  38468. **

  38469. **     ReadWrite() ->     (READWRITE | CREATE)

  38470. **     ReadOnly()  ->     (READONLY) 

  38471. **     OpenExclusive() -> (READWRITE | CREATE | EXCLUSIVE)

  38472. **

  38473. ** The old OpenExclusive() accepted a boolean argument - "delFlag". If

  38474. ** true, the file was configured to be automatically deleted when the

  38475. ** file handle closed. To achieve the same effect using this new 

  38476. ** interface, add the DELETEONCLOSE flag to those specified above for 

  38477. ** OpenExclusive().

  38478. */

  38479. static int unixOpen(

  38480.   sqlite3_vfs *pVfs,           /* The VFS for which this is the xOpen method */

  38481.   const char *zPath,           /* Pathname of file to be opened */

  38482.   sqlite3_file *pFile,         /* The file descriptor to be filled in */

  38483.   int flags,                   /* Input flags to control the opening */

  38484.   int *pOutFlags               /* Output flags returned to SQLite core */

  38485. ){

  38486.   unixFile *p = (unixFile *)pFile;

  38487.   int fd = -1;                   /* File descriptor returned by open() */

  38488.   int openFlags = 0;             /* Flags to pass to open() */

  38489.   int eType = flags&0xFFFFFF00;  /* Type of file to open */

  38490.   int noLock;                    /* True to omit locking primitives */

  38491.   int rc = SQLITE_OK;            /* Function Return Code */

  38492.   int ctrlFlags = 0;             /* UNIXFILE_* flags */

  38493. 

  38494.   int isExclusive  = (flags & SQLITE_OPEN_EXCLUSIVE);

  38495.   int isDelete     = (flags & SQLITE_OPEN_DELETEONCLOSE);

  38496.   int isCreate     = (flags & SQLITE_OPEN_CREATE);

  38497.   int isReadonly   = (flags & SQLITE_OPEN_READONLY);

  38498.   int isReadWrite  = (flags & SQLITE_OPEN_READWRITE);

  38499. #if SQLITE_ENABLE_LOCKING_STYLE

  38500.   int isAutoProxy  = (flags & SQLITE_OPEN_AUTOPROXY);

  38501. #endif

  38502. #if defined(__APPLE__) || SQLITE_ENABLE_LOCKING_STYLE

  38503.   struct statfs fsInfo;

  38504. #endif

  38505. 

  38506.   /* If creating a master or main-file journal, this function will open

  38507.   ** a file-descriptor on the directory too. The first time unixSync()

  38508.   ** is called the directory file descriptor will be fsync()ed and close()d.

  38509.   */

  38510.   int isNewJrnl = (isCreate && (

  38511.         eType==SQLITE_OPEN_MASTER_JOURNAL 

  38512.      || eType==SQLITE_OPEN_MAIN_JOURNAL 

  38513.      || eType==SQLITE_OPEN_WAL

  38514.   ));

  38515. 

  38516.   /* If argument zPath is a NULL pointer, this function is required to open

  38517.   ** a temporary file. Use this buffer to store the file name in.

  38518.   */

  38519.   char zTmpname[MAX_PATHNAME+2];

  38520.   const char *zName = zPath;

  38521. 

  38522.   /* Check the following statements are true: 

  38523.   **

  38524.   **   (a) Exactly one of the READWRITE and READONLY flags must be set, and 

  38525.   **   (b) if CREATE is set, then READWRITE must also be set, and

  38526.   **   (c) if EXCLUSIVE is set, then CREATE must also be set.

  38527.   **   (d) if DELETEONCLOSE is set, then CREATE must also be set.

  38528.   */

  38529.   assert((isReadonly==0 || isReadWrite==0) && (isReadWrite || isReadonly));

  38530.   assert(isCreate==0 || isReadWrite);

  38531.   assert(isExclusive==0 || isCreate);

  38532.   assert(isDelete==0 || isCreate);

  38533. 

  38534.   /* The main DB, main journal, WAL file and master journal are never 

  38535.   ** automatically deleted. Nor are they ever temporary files.  */

  38536.   assert( (!isDelete && zName) || eType!=SQLITE_OPEN_MAIN_DB );

  38537.   assert( (!isDelete && zName) || eType!=SQLITE_OPEN_MAIN_JOURNAL );

  38538.   assert( (!isDelete && zName) || eType!=SQLITE_OPEN_MASTER_JOURNAL );

  38539.   assert( (!isDelete && zName) || eType!=SQLITE_OPEN_WAL );

  38540. 

  38541.   /* Assert that the upper layer has set one of the "file-type" flags. */

  38542.   assert( eType==SQLITE_OPEN_MAIN_DB      || eType==SQLITE_OPEN_TEMP_DB 

  38543.        || eType==SQLITE_OPEN_MAIN_JOURNAL || eType==SQLITE_OPEN_TEMP_JOURNAL 

  38544.        || eType==SQLITE_OPEN_SUBJOURNAL   || eType==SQLITE_OPEN_MASTER_JOURNAL 

  38545.        || eType==SQLITE_OPEN_TRANSIENT_DB || eType==SQLITE_OPEN_WAL

  38546.   );

  38547. 

  38548.   /* Detect a pid change and reset the PRNG.  There is a race condition

  38549.   ** here such that two or more threads all trying to open databases at

  38550.   ** the same instant might all reset the PRNG.  But multiple resets

  38551.   ** are harmless.

  38552.   */

  38553.   if( randomnessPid!=osGetpid(0) ){

  38554.     randomnessPid = osGetpid(0);

  38555.     sqlite3_randomness(0,0);

  38556.   }

  38557.   memset(p, 0, sizeof(unixFile));

  38558. 

  38559.   if( eType==SQLITE_OPEN_MAIN_DB ){

  38560.     UnixUnusedFd *pUnused;

  38561.     pUnused = findReusableFd(zName, flags);

  38562.     if( pUnused ){

  38563.       fd = pUnused->fd;

  38564.     }else{

  38565.       pUnused = sqlite3_malloc64(sizeof(*pUnused));

  38566.       if( !pUnused ){

  38567.         return SQLITE_NOMEM_BKPT;

  38568.       }

  38569.     }

  38570.     p->pPreallocatedUnused = pUnused;

  38571. 

  38572.     /* Database filenames are double-zero terminated if they are not

  38573.     ** URIs with parameters.  Hence, they can always be passed into

  38574.     ** sqlite3_uri_parameter(). */

  38575.     assert( (flags & SQLITE_OPEN_URI) || zName[strlen(zName)+1]==0 );

  38576. 

  38577.   }else if( !zName ){

  38578.     /* If zName is NULL, the upper layer is requesting a temp file. */

  38579.     assert(isDelete && !isNewJrnl);

  38580.     rc = unixGetTempname(pVfs->mxPathname, zTmpname);

  38581.     if( rc!=SQLITE_OK ){

  38582.       return rc;

  38583.     }

  38584.     zName = zTmpname;

  38585. 

  38586.     /* Generated temporary filenames are always double-zero terminated

  38587.     ** for use by sqlite3_uri_parameter(). */

  38588.     assert( zName[strlen(zName)+1]==0 );

  38589.   }

  38590. 

  38591.   /* Determine the value of the flags parameter passed to POSIX function

  38592.   ** open(). These must be calculated even if open() is not called, as

  38593.   ** they may be stored as part of the file handle and used by the 

  38594.   ** 'conch file' locking functions later on.  */

  38595.   if( isReadonly )  openFlags |= O_RDONLY;

  38596.   if( isReadWrite ) openFlags |= O_RDWR;

  38597.   if( isCreate )    openFlags |= O_CREAT;

  38598.   if( isExclusive ) openFlags |= (O_EXCL|O_NOFOLLOW);

  38599.   openFlags |= (O_LARGEFILE|O_BINARY);

  38600. 

  38601.   if( fd<0 ){

  38602.     mode_t openMode;              /* Permissions to create file with */

  38603.     uid_t uid;                    /* Userid for the file */

  38604.     gid_t gid;                    /* Groupid for the file */

  38605.     rc = findCreateFileMode(zName, flags, &openMode, &uid, &gid);

  38606.     if( rc!=SQLITE_OK ){

  38607.       assert( !p->pPreallocatedUnused );

  38608.       assert( eType==SQLITE_OPEN_WAL || eType==SQLITE_OPEN_MAIN_JOURNAL );

  38609.       return rc;

  38610.     }

  38611.     fd = robust_open(zName, openFlags, openMode);

  38612.     OSTRACE(("OPENX   %-3d %s 0%o\n", fd, zName, openFlags));

  38613.     assert( !isExclusive || (openFlags & O_CREAT)!=0 );

  38614.     if( fd<0 ){

  38615.       if( isNewJrnl && errno==EACCES && osAccess(zName, F_OK) ){

  38616.         /* If unable to create a journal because the directory is not

  38617.         ** writable, change the error code to indicate that. */

  38618.         rc = SQLITE_READONLY_DIRECTORY;

  38619.       }else if( errno!=EISDIR && isReadWrite ){

  38620.         /* Failed to open the file for read/write access. Try read-only. */

  38621.         flags &= ~(SQLITE_OPEN_READWRITE|SQLITE_OPEN_CREATE);

  38622.         openFlags &= ~(O_RDWR|O_CREAT);

  38623.         flags |= SQLITE_OPEN_READONLY;

  38624.         openFlags |= O_RDONLY;

  38625.         isReadonly = 1;

  38626.         fd = robust_open(zName, openFlags, openMode);

  38627.       }

  38628.     }

  38629.     if( fd<0 ){

  38630.       int rc2 = unixLogError(SQLITE_CANTOPEN_BKPT, "open", zName);

  38631.       if( rc==SQLITE_OK ) rc = rc2;

  38632.       goto open_finished;

  38633.     }

  38634. 

  38635.     /* If this process is running as root and if creating a new rollback

  38636.     ** journal or WAL file, set the ownership of the journal or WAL to be

  38637.     ** the same as the original database.

  38638.     */

  38639.     if( flags & (SQLITE_OPEN_WAL|SQLITE_OPEN_MAIN_JOURNAL) ){

  38640.       robustFchown(fd, uid, gid);

  38641.     }

  38642.   }

  38643.   assert( fd>=0 );

  38644.   if( pOutFlags ){

  38645.     *pOutFlags = flags;

  38646.   }

  38647. 

  38648.   if( p->pPreallocatedUnused ){

  38649.     p->pPreallocatedUnused->fd = fd;

  38650.     p->pPreallocatedUnused->flags = flags;

  38651.   }

  38652. 

  38653.   if( isDelete ){

  38654. #if OS_VXWORKS

  38655.     zPath = zName;

  38656. #elif defined(SQLITE_UNLINK_AFTER_CLOSE)

  38657.     zPath = sqlite3_mprintf("%s", zName);

  38658.     if( zPath==0 ){

  38659.       robust_close(p, fd, __LINE__);

  38660.       return SQLITE_NOMEM_BKPT;

  38661.     }

  38662. #else

  38663.     osUnlink(zName);

  38664. #endif

  38665.   }

  38666. #if SQLITE_ENABLE_LOCKING_STYLE

  38667.   else{

  38668.     p->openFlags = openFlags;

  38669.   }

  38670. #endif

  38671.   

  38672. #if defined(__APPLE__) || SQLITE_ENABLE_LOCKING_STYLE

  38673.   if( fstatfs(fd, &fsInfo) == -1 ){

  38674.     storeLastErrno(p, errno);

  38675.     robust_close(p, fd, __LINE__);

  38676.     return SQLITE_IOERR_ACCESS;

  38677.   }

  38678.   if (0 == strncmp("msdos", fsInfo.f_fstypename, 5)) {

  38679.     ((unixFile*)pFile)->fsFlags |= SQLITE_FSFLAGS_IS_MSDOS;

  38680.   }

  38681.   if (0 == strncmp("exfat", fsInfo.f_fstypename, 5)) {

  38682.     ((unixFile*)pFile)->fsFlags |= SQLITE_FSFLAGS_IS_MSDOS;

  38683.   }

  38684. #endif

  38685. 

  38686.   /* Set up appropriate ctrlFlags */

  38687.   if( isDelete )                ctrlFlags |= UNIXFILE_DELETE;

  38688.   if( isReadonly )              ctrlFlags |= UNIXFILE_RDONLY;

  38689.   noLock = eType!=SQLITE_OPEN_MAIN_DB;

  38690.   if( noLock )                  ctrlFlags |= UNIXFILE_NOLOCK;

  38691.   if( isNewJrnl )               ctrlFlags |= UNIXFILE_DIRSYNC;

  38692.   if( flags & SQLITE_OPEN_URI ) ctrlFlags |= UNIXFILE_URI;

  38693. 

  38694. #if SQLITE_ENABLE_LOCKING_STYLE

  38695. #if SQLITE_PREFER_PROXY_LOCKING

  38696.   isAutoProxy = 1;

  38697. #endif

  38698.   if( isAutoProxy && (zPath!=NULL) && (!noLock) && pVfs->xOpen ){

  38699.     char *envforce = getenv("SQLITE_FORCE_PROXY_LOCKING");

  38700.     int useProxy = 0;

  38701. 

  38702.     /* SQLITE_FORCE_PROXY_LOCKING==1 means force always use proxy, 0 means 

  38703.     ** never use proxy, NULL means use proxy for non-local files only.  */

  38704.     if( envforce!=NULL ){

  38705.       useProxy = atoi(envforce)>0;

  38706.     }else{

  38707.       useProxy = !(fsInfo.f_flags&MNT_LOCAL);

  38708.     }

  38709.     if( useProxy ){

  38710.       rc = fillInUnixFile(pVfs, fd, pFile, zPath, ctrlFlags);

  38711.       if( rc==SQLITE_OK ){

  38712.         rc = proxyTransformUnixFile((unixFile*)pFile, ":auto:");

  38713.         if( rc!=SQLITE_OK ){

  38714.           /* Use unixClose to clean up the resources added in fillInUnixFile 

  38715.           ** and clear all the structure's references.  Specifically, 

  38716.           ** pFile->pMethods will be NULL so sqlite3OsClose will be a no-op 

  38717.           */

  38718.           unixClose(pFile);

  38719.           return rc;

  38720.         }

  38721.       }

  38722.       goto open_finished;

  38723.     }

  38724.   }

  38725. #endif

  38726.   

  38727.   assert( zPath==0 || zPath[0]=='/' 

  38728.       || eType==SQLITE_OPEN_MASTER_JOURNAL || eType==SQLITE_OPEN_MAIN_JOURNAL 

  38729.   );

  38730.   rc = fillInUnixFile(pVfs, fd, pFile, zPath, ctrlFlags);

  38731. 

  38732. open_finished:

  38733.   if( rc!=SQLITE_OK ){

  38734.     sqlite3_free(p->pPreallocatedUnused);

  38735.   }

  38736.   return rc;

  38737. }

  38738. 

  38739. 

  38740. /*

  38741. ** Delete the file at zPath. If the dirSync argument is true, fsync()

  38742. ** the directory after deleting the file.

  38743. */

  38744. static int unixDelete(

  38745.   sqlite3_vfs *NotUsed,     /* VFS containing this as the xDelete method */

  38746.   const char *zPath,        /* Name of file to be deleted */

  38747.   int dirSync               /* If true, fsync() directory after deleting file */

  38748. ){

  38749.   int rc = SQLITE_OK;

  38750.   UNUSED_PARAMETER(NotUsed);

  38751.   SimulateIOError(return SQLITE_IOERR_DELETE);

  38752.   if( osUnlink(zPath)==(-1) ){

  38753.     if( errno==ENOENT

  38754. #if OS_VXWORKS

  38755.         || osAccess(zPath,0)!=0

  38756. #endif

  38757.     ){

  38758.       rc = SQLITE_IOERR_DELETE_NOENT;

  38759.     }else{

  38760.       rc = unixLogError(SQLITE_IOERR_DELETE, "unlink", zPath);

  38761.     }

  38762.     return rc;

  38763.   }

  38764. #ifndef SQLITE_DISABLE_DIRSYNC

  38765.   if( (dirSync & 1)!=0 ){

  38766.     int fd;

  38767.     rc = osOpenDirectory(zPath, &fd);

  38768.     if( rc==SQLITE_OK ){

  38769.       if( full_fsync(fd,0,0) ){

  38770.         rc = unixLogError(SQLITE_IOERR_DIR_FSYNC, "fsync", zPath);

  38771.       }

  38772.       robust_close(0, fd, __LINE__);

  38773.     }else{

  38774.       assert( rc==SQLITE_CANTOPEN );

  38775.       rc = SQLITE_OK;

  38776.     }

  38777.   }

  38778. #endif

  38779.   return rc;

  38780. }

  38781. 

  38782. /*

  38783. ** Test the existence of or access permissions of file zPath. The

  38784. ** test performed depends on the value of flags:

  38785. **

  38786. **     SQLITE_ACCESS_EXISTS: Return 1 if the file exists

  38787. **     SQLITE_ACCESS_READWRITE: Return 1 if the file is read and writable.

  38788. **     SQLITE_ACCESS_READONLY: Return 1 if the file is readable.

  38789. **

  38790. ** Otherwise return 0.

  38791. */

  38792. static int unixAccess(

  38793.   sqlite3_vfs *NotUsed,   /* The VFS containing this xAccess method */

  38794.   const char *zPath,      /* Path of the file to examine */

  38795.   int flags,              /* What do we want to learn about the zPath file? */

  38796.   int *pResOut            /* Write result boolean here */

  38797. ){

  38798.   UNUSED_PARAMETER(NotUsed);

  38799.   SimulateIOError( return SQLITE_IOERR_ACCESS; );

  38800.   assert( pResOut!=0 );

  38801. 

  38802.   /* The spec says there are three possible values for flags.  But only

  38803.   ** two of them are actually used */

  38804.   assert( flags==SQLITE_ACCESS_EXISTS || flags==SQLITE_ACCESS_READWRITE );

  38805. 

  38806.   if( flags==SQLITE_ACCESS_EXISTS ){

  38807.     struct stat buf;

  38808.     *pResOut = (0==osStat(zPath, &buf) && buf.st_size>0);

  38809.   }else{

  38810.     *pResOut = osAccess(zPath, W_OK|R_OK)==0;

  38811.   }

  38812.   return SQLITE_OK;

  38813. }

  38814. 

  38815. /*

  38816. **

  38817. */

  38818. static int mkFullPathname(

  38819.   const char *zPath,              /* Input path */

  38820.   char *zOut,                     /* Output buffer */

  38821.   int nOut                        /* Allocated size of buffer zOut */

  38822. ){

  38823.   int nPath = sqlite3Strlen30(zPath);

  38824.   int iOff = 0;

  38825.   if( zPath[0]!='/' ){

  38826.     if( osGetcwd(zOut, nOut-2)==0 ){

  38827.       return unixLogError(SQLITE_CANTOPEN_BKPT, "getcwd", zPath);

  38828.     }

  38829.     iOff = sqlite3Strlen30(zOut);

  38830.     zOut[iOff++] = '/';

  38831.   }

  38832.   if( (iOff+nPath+1)>nOut ){

  38833.     /* SQLite assumes that xFullPathname() nul-terminates the output buffer

  38834.     ** even if it returns an error.  */

  38835.     zOut[iOff] = '\0';

  38836.     return SQLITE_CANTOPEN_BKPT;

  38837.   }

  38838.   sqlite3_snprintf(nOut-iOff, &zOut[iOff], "%s", zPath);

  38839.   return SQLITE_OK;

  38840. }

  38841. 

  38842. /*

  38843. ** Turn a relative pathname into a full pathname. The relative path

  38844. ** is stored as a nul-terminated string in the buffer pointed to by

  38845. ** zPath. 

  38846. **

  38847. ** zOut points to a buffer of at least sqlite3_vfs.mxPathname bytes 

  38848. ** (in this case, MAX_PATHNAME bytes). The full-path is written to

  38849. ** this buffer before returning.

  38850. */

  38851. static int unixFullPathname(

  38852.   sqlite3_vfs *pVfs,            /* Pointer to vfs object */

  38853.   const char *zPath,            /* Possibly relative input path */

  38854.   int nOut,                     /* Size of output buffer in bytes */

  38855.   char *zOut                    /* Output buffer */

  38856. ){

  38857. #if !defined(HAVE_READLINK) || !defined(HAVE_LSTAT)

  38858.   return mkFullPathname(zPath, zOut, nOut);

  38859. #else

  38860.   int rc = SQLITE_OK;

  38861.   int nByte;

  38862.   int nLink = 1;                /* Number of symbolic links followed so far */

  38863.   const char *zIn = zPath;      /* Input path for each iteration of loop */

  38864.   char *zDel = 0;

  38865. 

  38866.   assert( pVfs->mxPathname==MAX_PATHNAME );

  38867.   UNUSED_PARAMETER(pVfs);

  38868. 

  38869.   /* It's odd to simulate an io-error here, but really this is just

  38870.   ** using the io-error infrastructure to test that SQLite handles this

  38871.   ** function failing. This function could fail if, for example, the

  38872.   ** current working directory has been unlinked.

  38873.   */

  38874.   SimulateIOError( return SQLITE_ERROR );

  38875. 

  38876.   do {

  38877. 

  38878.     /* Call stat() on path zIn. Set bLink to true if the path is a symbolic

  38879.     ** link, or false otherwise.  */

  38880.     int bLink = 0;

  38881.     struct stat buf;

  38882.     if( osLstat(zIn, &buf)!=0 ){

  38883.       if( errno!=ENOENT ){

  38884.         rc = unixLogError(SQLITE_CANTOPEN_BKPT, "lstat", zIn);

  38885.       }

  38886.     }else{

  38887.       bLink = S_ISLNK(buf.st_mode);

  38888.     }

  38889. 

  38890.     if( bLink ){

  38891.       if( zDel==0 ){

  38892.         zDel = sqlite3_malloc(nOut);

  38893.         if( zDel==0 ) rc = SQLITE_NOMEM_BKPT;

  38894.       }else if( ++nLink>SQLITE_MAX_SYMLINKS ){

  38895.         rc = SQLITE_CANTOPEN_BKPT;

  38896.       }

  38897. 

  38898.       if( rc==SQLITE_OK ){

  38899.         nByte = osReadlink(zIn, zDel, nOut-1);

  38900.         if( nByte<0 ){

  38901.           rc = unixLogError(SQLITE_CANTOPEN_BKPT, "readlink", zIn);

  38902.         }else{

  38903.           if( zDel[0]!='/' ){

  38904.             int n;

  38905.             for(n = sqlite3Strlen30(zIn); n>0 && zIn[n-1]!='/'; n--);

  38906.             if( nByte+n+1>nOut ){

  38907.               rc = SQLITE_CANTOPEN_BKPT;

  38908.             }else{

  38909.               memmove(&zDel[n], zDel, nByte+1);

  38910.               memcpy(zDel, zIn, n);

  38911.               nByte += n;

  38912.             }

  38913.           }

  38914.           zDel[nByte] = '\0';

  38915.         }

  38916.       }

  38917. 

  38918.       zIn = zDel;

  38919.     }

  38920. 

  38921.     assert( rc!=SQLITE_OK || zIn!=zOut || zIn[0]=='/' );

  38922.     if( rc==SQLITE_OK && zIn!=zOut ){

  38923.       rc = mkFullPathname(zIn, zOut, nOut);

  38924.     }

  38925.     if( bLink==0 ) break;

  38926.     zIn = zOut;

  38927.   }while( rc==SQLITE_OK );

  38928. 

  38929.   sqlite3_free(zDel);

  38930.   return rc;

  38931. #endif   /* HAVE_READLINK && HAVE_LSTAT */

  38932. }

  38933. 

  38934. 

  38935. #ifndef SQLITE_OMIT_LOAD_EXTENSION

  38936. /*

  38937. ** Interfaces for opening a shared library, finding entry points

  38938. ** within the shared library, and closing the shared library.

  38939. */

  38940. #include <dlfcn.h>

  38941. static void *unixDlOpen(sqlite3_vfs *NotUsed, const char *zFilename){

  38942.   UNUSED_PARAMETER(NotUsed);

  38943.   return dlopen(zFilename, RTLD_NOW | RTLD_GLOBAL);

  38944. }

  38945. 

  38946. /*

  38947. ** SQLite calls this function immediately after a call to unixDlSym() or

  38948. ** unixDlOpen() fails (returns a null pointer). If a more detailed error

  38949. ** message is available, it is written to zBufOut. If no error message

  38950. ** is available, zBufOut is left unmodified and SQLite uses a default

  38951. ** error message.

  38952. */

  38953. static void unixDlError(sqlite3_vfs *NotUsed, int nBuf, char *zBufOut){

  38954.   const char *zErr;

  38955.   UNUSED_PARAMETER(NotUsed);

  38956.   unixEnterMutex();

  38957.   zErr = dlerror();

  38958.   if( zErr ){

  38959.     sqlite3_snprintf(nBuf, zBufOut, "%s", zErr);

  38960.   }

  38961.   unixLeaveMutex();

  38962. }

  38963. static void (*unixDlSym(sqlite3_vfs *NotUsed, void *p, const char*zSym))(void){

  38964.   /* 

  38965.   ** GCC with -pedantic-errors says that C90 does not allow a void* to be

  38966.   ** cast into a pointer to a function.  And yet the library dlsym() routine

  38967.   ** returns a void* which is really a pointer to a function.  So how do we

  38968.   ** use dlsym() with -pedantic-errors?

  38969.   **

  38970.   ** Variable x below is defined to be a pointer to a function taking

  38971.   ** parameters void* and const char* and returning a pointer to a function.

  38972.   ** We initialize x by assigning it a pointer to the dlsym() function.

  38973.   ** (That assignment requires a cast.)  Then we call the function that

  38974.   ** x points to.  

  38975.   **

  38976.   ** This work-around is unlikely to work correctly on any system where

  38977.   ** you really cannot cast a function pointer into void*.  But then, on the

  38978.   ** other hand, dlsym() will not work on such a system either, so we have

  38979.   ** not really lost anything.

  38980.   */

  38981.   void (*(*x)(void*,const char*))(void);

  38982.   UNUSED_PARAMETER(NotUsed);

  38983.   x = (void(*(*)(void*,const char*))(void))dlsym;

  38984.   return (*x)(p, zSym);

  38985. }

  38986. static void unixDlClose(sqlite3_vfs *NotUsed, void *pHandle){

  38987.   UNUSED_PARAMETER(NotUsed);

  38988.   dlclose(pHandle);

  38989. }

  38990. #else /* if SQLITE_OMIT_LOAD_EXTENSION is defined: */

  38991.   #define unixDlOpen  0

  38992.   #define unixDlError 0

  38993.   #define unixDlSym   0

  38994.   #define unixDlClose 0

  38995. #endif

  38996. 

  38997. /*

  38998. ** Write nBuf bytes of random data to the supplied buffer zBuf.

  38999. */

  39000. static int unixRandomness(sqlite3_vfs *NotUsed, int nBuf, char *zBuf){

  39001.   UNUSED_PARAMETER(NotUsed);

  39002.   assert((size_t)nBuf>=(sizeof(time_t)+sizeof(int)));

  39003. 

  39004.   /* We have to initialize zBuf to prevent valgrind from reporting

  39005.   ** errors.  The reports issued by valgrind are incorrect - we would

  39006.   ** prefer that the randomness be increased by making use of the

  39007.   ** uninitialized space in zBuf - but valgrind errors tend to worry

  39008.   ** some users.  Rather than argue, it seems easier just to initialize

  39009.   ** the whole array and silence valgrind, even if that means less randomness

  39010.   ** in the random seed.

  39011.   **

  39012.   ** When testing, initializing zBuf[] to zero is all we do.  That means

  39013.   ** that we always use the same random number sequence.  This makes the

  39014.   ** tests repeatable.

  39015.   */

  39016.   memset(zBuf, 0, nBuf);

  39017.   randomnessPid = osGetpid(0);  

  39018. #if !defined(SQLITE_TEST) && !defined(SQLITE_OMIT_RANDOMNESS)

  39019.   {

  39020.     int fd, got;

  39021.     fd = robust_open("/dev/urandom", O_RDONLY, 0);

  39022.     if( fd<0 ){

  39023.       time_t t;

  39024.       time(&t);

  39025.       memcpy(zBuf, &t, sizeof(t));

  39026.       memcpy(&zBuf[sizeof(t)], &randomnessPid, sizeof(randomnessPid));

  39027.       assert( sizeof(t)+sizeof(randomnessPid)<=(size_t)nBuf );

  39028.       nBuf = sizeof(t) + sizeof(randomnessPid);

  39029.     }else{

  39030.       do{ got = osRead(fd, zBuf, nBuf); }while( got<0 && errno==EINTR );

  39031.       robust_close(0, fd, __LINE__);

  39032.     }

  39033.   }

  39034. #endif

  39035.   return nBuf;

  39036. }

  39037. 

  39038. 

  39039. /*

  39040. ** Sleep for a little while.  Return the amount of time slept.

  39041. ** The argument is the number of microseconds we want to sleep.

  39042. ** The return value is the number of microseconds of sleep actually

  39043. ** requested from the underlying operating system, a number which

  39044. ** might be greater than or equal to the argument, but not less

  39045. ** than the argument.

  39046. */

  39047. static int unixSleep(sqlite3_vfs *NotUsed, int microseconds){

  39048. #if OS_VXWORKS

  39049.   struct timespec sp;

  39050. 

  39051.   sp.tv_sec = microseconds / 1000000;

  39052.   sp.tv_nsec = (microseconds % 1000000) * 1000;

  39053.   nanosleep(&sp, NULL);

  39054.   UNUSED_PARAMETER(NotUsed);

  39055.   return microseconds;

  39056. #elif defined(HAVE_USLEEP) && HAVE_USLEEP

  39057.   usleep(microseconds);

  39058.   UNUSED_PARAMETER(NotUsed);

  39059.   return microseconds;

  39060. #else

  39061.   int seconds = (microseconds+999999)/1000000;

  39062.   sleep(seconds);

  39063.   UNUSED_PARAMETER(NotUsed);

  39064.   return seconds*1000000;

  39065. #endif

  39066. }

  39067. 

  39068. /*

  39069. ** The following variable, if set to a non-zero value, is interpreted as

  39070. ** the number of seconds since 1970 and is used to set the result of

  39071. ** sqlite3OsCurrentTime() during testing.

  39072. */

  39073. #ifdef SQLITE_TEST

  39074. SQLITE_API int sqlite3_current_time = 0;  /* Fake system time in seconds since 1970. */

  39075. #endif

  39076. 

  39077. /*

  39078. ** Find the current time (in Universal Coordinated Time).  Write into *piNow

  39079. ** the current time and date as a Julian Day number times 86_400_000.  In

  39080. ** other words, write into *piNow the number of milliseconds since the Julian

  39081. ** epoch of noon in Greenwich on November 24, 4714 B.C according to the

  39082. ** proleptic Gregorian calendar.

  39083. **

  39084. ** On success, return SQLITE_OK.  Return SQLITE_ERROR if the time and date 

  39085. ** cannot be found.

  39086. */

  39087. static int unixCurrentTimeInt64(sqlite3_vfs *NotUsed, sqlite3_int64 *piNow){

  39088.   static const sqlite3_int64 unixEpoch = 24405875*(sqlite3_int64)8640000;

  39089.   int rc = SQLITE_OK;

  39090. #if defined(NO_GETTOD)

  39091.   time_t t;

  39092.   time(&t);

  39093.   *piNow = ((sqlite3_int64)t)*1000 + unixEpoch;

  39094. #elif OS_VXWORKS

  39095.   struct timespec sNow;

  39096.   clock_gettime(CLOCK_REALTIME, &sNow);

  39097.   *piNow = unixEpoch + 1000*(sqlite3_int64)sNow.tv_sec + sNow.tv_nsec/1000000;

  39098. #else

  39099.   struct timeval sNow;

  39100.   (void)gettimeofday(&sNow, 0);  /* Cannot fail given valid arguments */

  39101.   *piNow = unixEpoch + 1000*(sqlite3_int64)sNow.tv_sec + sNow.tv_usec/1000;

  39102. #endif

  39103. 

  39104. #ifdef SQLITE_TEST

  39105.   if( sqlite3_current_time ){

  39106.     *piNow = 1000*(sqlite3_int64)sqlite3_current_time + unixEpoch;

  39107.   }

  39108. #endif

  39109.   UNUSED_PARAMETER(NotUsed);

  39110.   return rc;

  39111. }

  39112. 

  39113. #ifndef SQLITE_OMIT_DEPRECATED

  39114. /*

  39115. ** Find the current time (in Universal Coordinated Time).  Write the

  39116. ** current time and date as a Julian Day number into *prNow and

  39117. ** return 0.  Return 1 if the time and date cannot be found.

  39118. */

  39119. static int unixCurrentTime(sqlite3_vfs *NotUsed, double *prNow){

  39120.   sqlite3_int64 i = 0;

  39121.   int rc;

  39122.   UNUSED_PARAMETER(NotUsed);

  39123.   rc = unixCurrentTimeInt64(0, &i);

  39124.   *prNow = i/86400000.0;

  39125.   return rc;

  39126. }

  39127. #else

  39128. # define unixCurrentTime 0

  39129. #endif

  39130. 

  39131. /*

  39132. ** The xGetLastError() method is designed to return a better

  39133. ** low-level error message when operating-system problems come up

  39134. ** during SQLite operation.  Only the integer return code is currently

  39135. ** used.

  39136. */

  39137. static int unixGetLastError(sqlite3_vfs *NotUsed, int NotUsed2, char *NotUsed3){

  39138.   UNUSED_PARAMETER(NotUsed);

  39139.   UNUSED_PARAMETER(NotUsed2);

  39140.   UNUSED_PARAMETER(NotUsed3);

  39141.   return errno;

  39142. }

  39143. 

  39144. 

  39145. /*

  39146. ************************ End of sqlite3_vfs methods ***************************

  39147. ******************************************************************************/

  39148. 

  39149. /******************************************************************************

  39150. ************************** Begin Proxy Locking ********************************

  39151. **

  39152. ** Proxy locking is a "uber-locking-method" in this sense:  It uses the

  39153. ** other locking methods on secondary lock files.  Proxy locking is a

  39154. ** meta-layer over top of the primitive locking implemented above.  For

  39155. ** this reason, the division that implements of proxy locking is deferred

  39156. ** until late in the file (here) after all of the other I/O methods have

  39157. ** been defined - so that the primitive locking methods are available

  39158. ** as services to help with the implementation of proxy locking.

  39159. **

  39160. ****

  39161. **

  39162. ** The default locking schemes in SQLite use byte-range locks on the

  39163. ** database file to coordinate safe, concurrent access by multiple readers

  39164. ** and writers [http://sqlite.org/lockingv3.html].  The five file locking

  39165. ** states (UNLOCKED, PENDING, SHARED, RESERVED, EXCLUSIVE) are implemented

  39166. ** as POSIX read & write locks over fixed set of locations (via fsctl),

  39167. ** on AFP and SMB only exclusive byte-range locks are available via fsctl

  39168. ** with _IOWR('z', 23, struct ByteRangeLockPB2) to track the same 5 states.

  39169. ** To simulate a F_RDLCK on the shared range, on AFP a randomly selected

  39170. ** address in the shared range is taken for a SHARED lock, the entire

  39171. ** shared range is taken for an EXCLUSIVE lock):

  39172. **

  39173. **      PENDING_BYTE        0x40000000

  39174. **      RESERVED_BYTE       0x40000001

  39175. **      SHARED_RANGE        0x40000002 -> 0x40000200

  39176. **

  39177. ** This works well on the local file system, but shows a nearly 100x

  39178. ** slowdown in read performance on AFP because the AFP client disables

  39179. ** the read cache when byte-range locks are present.  Enabling the read

  39180. ** cache exposes a cache coherency problem that is present on all OS X

  39181. ** supported network file systems.  NFS and AFP both observe the

  39182. ** close-to-open semantics for ensuring cache coherency

  39183. ** [http://nfs.sourceforge.net/#faq_a8], which does not effectively

  39184. ** address the requirements for concurrent database access by multiple

  39185. ** readers and writers

  39186. ** [http://www.nabble.com/SQLite-on-NFS-cache-coherency-td15655701.html].

  39187. **

  39188. ** To address the performance and cache coherency issues, proxy file locking

  39189. ** changes the way database access is controlled by limiting access to a

  39190. ** single host at a time and moving file locks off of the database file

  39191. ** and onto a proxy file on the local file system.  

  39192. **

  39193. **

  39194. ** Using proxy locks

  39195. ** -----------------

  39196. **

  39197. ** C APIs

  39198. **

  39199. **  sqlite3_file_control(db, dbname, SQLITE_FCNTL_SET_LOCKPROXYFILE,

  39200. **                       <proxy_path> | ":auto:");

  39201. **  sqlite3_file_control(db, dbname, SQLITE_FCNTL_GET_LOCKPROXYFILE,

  39202. **                       &<proxy_path>);

  39203. **

  39204. **

  39205. ** SQL pragmas

  39206. **

  39207. **  PRAGMA [database.]lock_proxy_file=<proxy_path> | :auto:

  39208. **  PRAGMA [database.]lock_proxy_file

  39209. **

  39210. ** Specifying ":auto:" means that if there is a conch file with a matching

  39211. ** host ID in it, the proxy path in the conch file will be used, otherwise

  39212. ** a proxy path based on the user's temp dir

  39213. ** (via confstr(_CS_DARWIN_USER_TEMP_DIR,...)) will be used and the

  39214. ** actual proxy file name is generated from the name and path of the

  39215. ** database file.  For example:

  39216. **

  39217. **       For database path "/Users/me/foo.db" 

  39218. **       The lock path will be "<tmpdir>/sqliteplocks/_Users_me_foo.db:auto:")

  39219. **

  39220. ** Once a lock proxy is configured for a database connection, it can not

  39221. ** be removed, however it may be switched to a different proxy path via

  39222. ** the above APIs (assuming the conch file is not being held by another

  39223. ** connection or process). 

  39224. **

  39225. **

  39226. ** How proxy locking works

  39227. ** -----------------------

  39228. **

  39229. ** Proxy file locking relies primarily on two new supporting files: 

  39230. **

  39231. **   *  conch file to limit access to the database file to a single host

  39232. **      at a time

  39233. **

  39234. **   *  proxy file to act as a proxy for the advisory locks normally

  39235. **      taken on the database

  39236. **

  39237. ** The conch file - to use a proxy file, sqlite must first "hold the conch"

  39238. ** by taking an sqlite-style shared lock on the conch file, reading the

  39239. ** contents and comparing the host's unique host ID (see below) and lock

  39240. ** proxy path against the values stored in the conch.  The conch file is

  39241. ** stored in the same directory as the database file and the file name

  39242. ** is patterned after the database file name as ".<databasename>-conch".

  39243. ** If the conch file does not exist, or its contents do not match the

  39244. ** host ID and/or proxy path, then the lock is escalated to an exclusive

  39245. ** lock and the conch file contents is updated with the host ID and proxy

  39246. ** path and the lock is downgraded to a shared lock again.  If the conch

  39247. ** is held by another process (with a shared lock), the exclusive lock

  39248. ** will fail and SQLITE_BUSY is returned.

  39249. **

  39250. ** The proxy file - a single-byte file used for all advisory file locks

  39251. ** normally taken on the database file.   This allows for safe sharing

  39252. ** of the database file for multiple readers and writers on the same

  39253. ** host (the conch ensures that they all use the same local lock file).

  39254. **

  39255. ** Requesting the lock proxy does not immediately take the conch, it is

  39256. ** only taken when the first request to lock database file is made.  

  39257. ** This matches the semantics of the traditional locking behavior, where

  39258. ** opening a connection to a database file does not take a lock on it.

  39259. ** The shared lock and an open file descriptor are maintained until 

  39260. ** the connection to the database is closed. 

  39261. **

  39262. ** The proxy file and the lock file are never deleted so they only need

  39263. ** to be created the first time they are used.

  39264. **

  39265. ** Configuration options

  39266. ** ---------------------

  39267. **

  39268. **  SQLITE_PREFER_PROXY_LOCKING

  39269. **

  39270. **       Database files accessed on non-local file systems are

  39271. **       automatically configured for proxy locking, lock files are

  39272. **       named automatically using the same logic as

  39273. **       PRAGMA lock_proxy_file=":auto:"

  39274. **    

  39275. **  SQLITE_PROXY_DEBUG

  39276. **

  39277. **       Enables the logging of error messages during host id file

  39278. **       retrieval and creation

  39279. **

  39280. **  LOCKPROXYDIR

  39281. **

  39282. **       Overrides the default directory used for lock proxy files that

  39283. **       are named automatically via the ":auto:" setting

  39284. **

  39285. **  SQLITE_DEFAULT_PROXYDIR_PERMISSIONS

  39286. **

  39287. **       Permissions to use when creating a directory for storing the

  39288. **       lock proxy files, only used when LOCKPROXYDIR is not set.

  39289. **    

  39290. **    

  39291. ** As mentioned above, when compiled with SQLITE_PREFER_PROXY_LOCKING,

  39292. ** setting the environment variable SQLITE_FORCE_PROXY_LOCKING to 1 will

  39293. ** force proxy locking to be used for every database file opened, and 0

  39294. ** will force automatic proxy locking to be disabled for all database

  39295. ** files (explicitly calling the SQLITE_FCNTL_SET_LOCKPROXYFILE pragma or

  39296. ** sqlite_file_control API is not affected by SQLITE_FORCE_PROXY_LOCKING).

  39297. */

  39298. 

  39299. /*

  39300. ** Proxy locking is only available on MacOSX 

  39301. */

  39302. #if defined(__APPLE__) && SQLITE_ENABLE_LOCKING_STYLE

  39303. 

  39304. /*

  39305. ** The proxyLockingContext has the path and file structures for the remote 

  39306. ** and local proxy files in it

  39307. */

  39308. typedef struct proxyLockingContext proxyLockingContext;

  39309. struct proxyLockingContext {

  39310.   unixFile *conchFile;         /* Open conch file */

  39311.   char *conchFilePath;         /* Name of the conch file */

  39312.   unixFile *lockProxy;         /* Open proxy lock file */

  39313.   char *lockProxyPath;         /* Name of the proxy lock file */

  39314.   char *dbPath;                /* Name of the open file */

  39315.   int conchHeld;               /* 1 if the conch is held, -1 if lockless */

  39316.   int nFails;                  /* Number of conch taking failures */

  39317.   void *oldLockingContext;     /* Original lockingcontext to restore on close */

  39318.   sqlite3_io_methods const *pOldMethod;     /* Original I/O methods for close */

  39319. };

  39320. 

  39321. /* 

  39322. ** The proxy lock file path for the database at dbPath is written into lPath, 

  39323. ** which must point to valid, writable memory large enough for a maxLen length

  39324. ** file path. 

  39325. */

  39326. static int proxyGetLockPath(const char *dbPath, char *lPath, size_t maxLen){

  39327.   int len;

  39328.   int dbLen;

  39329.   int i;

  39330. 

  39331. #ifdef LOCKPROXYDIR

  39332.   len = strlcpy(lPath, LOCKPROXYDIR, maxLen);

  39333. #else

  39334. # ifdef _CS_DARWIN_USER_TEMP_DIR

  39335.   {

  39336.     if( !confstr(_CS_DARWIN_USER_TEMP_DIR, lPath, maxLen) ){

  39337.       OSTRACE(("GETLOCKPATH  failed %s errno=%d pid=%d\n",

  39338.                lPath, errno, osGetpid(0)));

  39339.       return SQLITE_IOERR_LOCK;

  39340.     }

  39341.     len = strlcat(lPath, "sqliteplocks", maxLen);    

  39342.   }

  39343. # else

  39344.   len = strlcpy(lPath, "/tmp/", maxLen);

  39345. # endif

  39346. #endif

  39347. 

  39348.   if( lPath[len-1]!='/' ){

  39349.     len = strlcat(lPath, "/", maxLen);

  39350.   }

  39351.   

  39352.   /* transform the db path to a unique cache name */

  39353.   dbLen = (int)strlen(dbPath);

  39354.   for( i=0; i<dbLen && (i+len+7)<(int)maxLen; i++){

  39355.     char c = dbPath[i];

  39356.     lPath[i+len] = (c=='/')?'_':c;

  39357.   }

  39358.   lPath[i+len]='\0';

  39359.   strlcat(lPath, ":auto:", maxLen);

  39360.   OSTRACE(("GETLOCKPATH  proxy lock path=%s pid=%d\n", lPath, osGetpid(0)));

  39361.   return SQLITE_OK;

  39362. }

  39363. 

  39364. /* 

  39365.  ** Creates the lock file and any missing directories in lockPath

  39366.  */

  39367. static int proxyCreateLockPath(const char *lockPath){

  39368.   int i, len;

  39369.   char buf[MAXPATHLEN];

  39370.   int start = 0;

  39371.   

  39372.   assert(lockPath!=NULL);

  39373.   /* try to create all the intermediate directories */

  39374.   len = (int)strlen(lockPath);

  39375.   buf[0] = lockPath[0];

  39376.   for( i=1; i<len; i++ ){

  39377.     if( lockPath[i] == '/' && (i - start > 0) ){

  39378.       /* only mkdir if leaf dir != "." or "/" or ".." */

  39379.       if( i-start>2 || (i-start==1 && buf[start] != '.' && buf[start] != '/') 

  39380.          || (i-start==2 && buf[start] != '.' && buf[start+1] != '.') ){

  39381.         buf[i]='\0';

  39382.         if( osMkdir(buf, SQLITE_DEFAULT_PROXYDIR_PERMISSIONS) ){

  39383.           int err=errno;

  39384.           if( err!=EEXIST ) {

  39385.             OSTRACE(("CREATELOCKPATH  FAILED creating %s, "

  39386.                      "'%s' proxy lock path=%s pid=%d\n",

  39387.                      buf, strerror(err), lockPath, osGetpid(0)));

  39388.             return err;

  39389.           }

  39390.         }

  39391.       }

  39392.       start=i+1;

  39393.     }

  39394.     buf[i] = lockPath[i];

  39395.   }

  39396.   OSTRACE(("CREATELOCKPATH  proxy lock path=%s pid=%d\n",lockPath,osGetpid(0)));

  39397.   return 0;

  39398. }

  39399. 

  39400. /*

  39401. ** Create a new VFS file descriptor (stored in memory obtained from

  39402. ** sqlite3_malloc) and open the file named "path" in the file descriptor.

  39403. **

  39404. ** The caller is responsible not only for closing the file descriptor

  39405. ** but also for freeing the memory associated with the file descriptor.

  39406. */

  39407. static int proxyCreateUnixFile(

  39408.     const char *path,        /* path for the new unixFile */

  39409.     unixFile **ppFile,       /* unixFile created and returned by ref */

  39410.     int islockfile           /* if non zero missing dirs will be created */

  39411. ) {

  39412.   int fd = -1;

  39413.   unixFile *pNew;

  39414.   int rc = SQLITE_OK;

  39415.   int openFlags = O_RDWR | O_CREAT;

  39416.   sqlite3_vfs dummyVfs;

  39417.   int terrno = 0;

  39418.   UnixUnusedFd *pUnused = NULL;

  39419. 

  39420.   /* 1. first try to open/create the file

  39421.   ** 2. if that fails, and this is a lock file (not-conch), try creating

  39422.   ** the parent directories and then try again.

  39423.   ** 3. if that fails, try to open the file read-only

  39424.   ** otherwise return BUSY (if lock file) or CANTOPEN for the conch file

  39425.   */

  39426.   pUnused = findReusableFd(path, openFlags);

  39427.   if( pUnused ){

  39428.     fd = pUnused->fd;

  39429.   }else{

  39430.     pUnused = sqlite3_malloc64(sizeof(*pUnused));

  39431.     if( !pUnused ){

  39432.       return SQLITE_NOMEM_BKPT;

  39433.     }

  39434.   }

  39435.   if( fd<0 ){

  39436.     fd = robust_open(path, openFlags, 0);

  39437.     terrno = errno;

  39438.     if( fd<0 && errno==ENOENT && islockfile ){

  39439.       if( proxyCreateLockPath(path) == SQLITE_OK ){

  39440.         fd = robust_open(path, openFlags, 0);

  39441.       }

  39442.     }

  39443.   }

  39444.   if( fd<0 ){

  39445.     openFlags = O_RDONLY;

  39446.     fd = robust_open(path, openFlags, 0);

  39447.     terrno = errno;

  39448.   }

  39449.   if( fd<0 ){

  39450.     if( islockfile ){

  39451.       return SQLITE_BUSY;

  39452.     }

  39453.     switch (terrno) {

  39454.       case EACCES:

  39455.         return SQLITE_PERM;

  39456.       case EIO: 

  39457.         return SQLITE_IOERR_LOCK; /* even though it is the conch */

  39458.       default:

  39459.         return SQLITE_CANTOPEN_BKPT;

  39460.     }

  39461.   }

  39462.   

  39463.   pNew = (unixFile *)sqlite3_malloc64(sizeof(*pNew));

  39464.   if( pNew==NULL ){

  39465.     rc = SQLITE_NOMEM_BKPT;

  39466.     goto end_create_proxy;

  39467.   }

  39468.   memset(pNew, 0, sizeof(unixFile));

  39469.   pNew->openFlags = openFlags;

  39470.   memset(&dummyVfs, 0, sizeof(dummyVfs));

  39471.   dummyVfs.pAppData = (void*)&autolockIoFinder;

  39472.   dummyVfs.zName = "dummy";

  39473.   pUnused->fd = fd;

  39474.   pUnused->flags = openFlags;

  39475.   pNew->pPreallocatedUnused = pUnused;

  39476.   

  39477.   rc = fillInUnixFile(&dummyVfs, fd, (sqlite3_file*)pNew, path, 0);

  39478.   if( rc==SQLITE_OK ){

  39479.     *ppFile = pNew;

  39480.     return SQLITE_OK;

  39481.   }

  39482. end_create_proxy:    

  39483.   robust_close(pNew, fd, __LINE__);

  39484.   sqlite3_free(pNew);

  39485.   sqlite3_free(pUnused);

  39486.   return rc;

  39487. }

  39488. 

  39489. #ifdef SQLITE_TEST

  39490. /* simulate multiple hosts by creating unique hostid file paths */

  39491. SQLITE_API int sqlite3_hostid_num = 0;

  39492. #endif

  39493. 

  39494. #define PROXY_HOSTIDLEN    16  /* conch file host id length */

  39495. 

  39496. #ifdef HAVE_GETHOSTUUID

  39497. /* Not always defined in the headers as it ought to be */

  39498. extern int gethostuuid(uuid_t id, const struct timespec *wait);

  39499. #endif

  39500. 

  39501. /* get the host ID via gethostuuid(), pHostID must point to PROXY_HOSTIDLEN 

  39502. ** bytes of writable memory.

  39503. */

  39504. static int proxyGetHostID(unsigned char *pHostID, int *pError){

  39505.   assert(PROXY_HOSTIDLEN == sizeof(uuid_t));

  39506.   memset(pHostID, 0, PROXY_HOSTIDLEN);

  39507. #ifdef HAVE_GETHOSTUUID

  39508.   {

  39509.     struct timespec timeout = {1, 0}; /* 1 sec timeout */

  39510.     if( gethostuuid(pHostID, &timeout) ){

  39511.       int err = errno;

  39512.       if( pError ){

  39513.         *pError = err;

  39514.       }

  39515.       return SQLITE_IOERR;

  39516.     }

  39517.   }

  39518. #else

  39519.   UNUSED_PARAMETER(pError);

  39520. #endif

  39521. #ifdef SQLITE_TEST

  39522.   /* simulate multiple hosts by creating unique hostid file paths */

  39523.   if( sqlite3_hostid_num != 0){

  39524.     pHostID[0] = (char)(pHostID[0] + (char)(sqlite3_hostid_num & 0xFF));

  39525.   }

  39526. #endif

  39527.   

  39528.   return SQLITE_OK;

  39529. }

  39530. 

  39531. /* The conch file contains the header, host id and lock file path

  39532.  */

  39533. #define PROXY_CONCHVERSION 2   /* 1-byte header, 16-byte host id, path */

  39534. #define PROXY_HEADERLEN    1   /* conch file header length */

  39535. #define PROXY_PATHINDEX    (PROXY_HEADERLEN+PROXY_HOSTIDLEN)

  39536. #define PROXY_MAXCONCHLEN  (PROXY_HEADERLEN+PROXY_HOSTIDLEN+MAXPATHLEN)

  39537. 

  39538. /* 

  39539. ** Takes an open conch file, copies the contents to a new path and then moves 

  39540. ** it back.  The newly created file's file descriptor is assigned to the

  39541. ** conch file structure and finally the original conch file descriptor is 

  39542. ** closed.  Returns zero if successful.

  39543. */

  39544. static int proxyBreakConchLock(unixFile *pFile, uuid_t myHostID){

  39545.   proxyLockingContext *pCtx = (proxyLockingContext *)pFile->lockingContext; 

  39546.   unixFile *conchFile = pCtx->conchFile;

  39547.   char tPath[MAXPATHLEN];

  39548.   char buf[PROXY_MAXCONCHLEN];

  39549.   char *cPath = pCtx->conchFilePath;

  39550.   size_t readLen = 0;

  39551.   size_t pathLen = 0;

  39552.   char errmsg[64] = "";

  39553.   int fd = -1;

  39554.   int rc = -1;

  39555.   UNUSED_PARAMETER(myHostID);

  39556. 

  39557.   /* create a new path by replace the trailing '-conch' with '-break' */

  39558.   pathLen = strlcpy(tPath, cPath, MAXPATHLEN);

  39559.   if( pathLen>MAXPATHLEN || pathLen<6 || 

  39560.      (strlcpy(&tPath[pathLen-5], "break", 6) != 5) ){

  39561.     sqlite3_snprintf(sizeof(errmsg),errmsg,"path error (len %d)",(int)pathLen);

  39562.     goto end_breaklock;

  39563.   }

  39564.   /* read the conch content */

  39565.   readLen = osPread(conchFile->h, buf, PROXY_MAXCONCHLEN, 0);

  39566.   if( readLen<PROXY_PATHINDEX ){

  39567.     sqlite3_snprintf(sizeof(errmsg),errmsg,"read error (len %d)",(int)readLen);

  39568.     goto end_breaklock;

  39569.   }

  39570.   /* write it out to the temporary break file */

  39571.   fd = robust_open(tPath, (O_RDWR|O_CREAT|O_EXCL), 0);

  39572.   if( fd<0 ){

  39573.     sqlite3_snprintf(sizeof(errmsg), errmsg, "create failed (%d)", errno);

  39574.     goto end_breaklock;

  39575.   }

  39576.   if( osPwrite(fd, buf, readLen, 0) != (ssize_t)readLen ){

  39577.     sqlite3_snprintf(sizeof(errmsg), errmsg, "write failed (%d)", errno);

  39578.     goto end_breaklock;

  39579.   }

  39580.   if( rename(tPath, cPath) ){

  39581.     sqlite3_snprintf(sizeof(errmsg), errmsg, "rename failed (%d)", errno);

  39582.     goto end_breaklock;

  39583.   }

  39584.   rc = 0;

  39585.   fprintf(stderr, "broke stale lock on %s\n", cPath);

  39586.   robust_close(pFile, conchFile->h, __LINE__);

  39587.   conchFile->h = fd;

  39588.   conchFile->openFlags = O_RDWR | O_CREAT;

  39589. 

  39590. end_breaklock:

  39591.   if( rc ){

  39592.     if( fd>=0 ){

  39593.       osUnlink(tPath);

  39594.       robust_close(pFile, fd, __LINE__);

  39595.     }

  39596.     fprintf(stderr, "failed to break stale lock on %s, %s\n", cPath, errmsg);

  39597.   }

  39598.   return rc;

  39599. }

  39600. 

  39601. /* Take the requested lock on the conch file and break a stale lock if the 

  39602. ** host id matches.

  39603. */

  39604. static int proxyConchLock(unixFile *pFile, uuid_t myHostID, int lockType){

  39605.   proxyLockingContext *pCtx = (proxyLockingContext *)pFile->lockingContext; 

  39606.   unixFile *conchFile = pCtx->conchFile;

  39607.   int rc = SQLITE_OK;

  39608.   int nTries = 0;

  39609.   struct timespec conchModTime;

  39610.   

  39611.   memset(&conchModTime, 0, sizeof(conchModTime));

  39612.   do {

  39613.     rc = conchFile->pMethod->xLock((sqlite3_file*)conchFile, lockType);

  39614.     nTries ++;

  39615.     if( rc==SQLITE_BUSY ){

  39616.       /* If the lock failed (busy):

  39617.        * 1st try: get the mod time of the conch, wait 0.5s and try again. 

  39618.        * 2nd try: fail if the mod time changed or host id is different, wait 

  39619.        *           10 sec and try again

  39620.        * 3rd try: break the lock unless the mod time has changed.

  39621.        */

  39622.       struct stat buf;

  39623.       if( osFstat(conchFile->h, &buf) ){

  39624.         storeLastErrno(pFile, errno);

  39625.         return SQLITE_IOERR_LOCK;

  39626.       }

  39627.       

  39628.       if( nTries==1 ){

  39629.         conchModTime = buf.st_mtimespec;

  39630.         usleep(500000); /* wait 0.5 sec and try the lock again*/

  39631.         continue;  

  39632.       }

  39633. 

  39634.       assert( nTries>1 );

  39635.       if( conchModTime.tv_sec != buf.st_mtimespec.tv_sec || 

  39636.          conchModTime.tv_nsec != buf.st_mtimespec.tv_nsec ){

  39637.         return SQLITE_BUSY;

  39638.       }

  39639.       

  39640.       if( nTries==2 ){  

  39641.         char tBuf[PROXY_MAXCONCHLEN];

  39642.         int len = osPread(conchFile->h, tBuf, PROXY_MAXCONCHLEN, 0);

  39643.         if( len<0 ){

  39644.           storeLastErrno(pFile, errno);

  39645.           return SQLITE_IOERR_LOCK;

  39646.         }

  39647.         if( len>PROXY_PATHINDEX && tBuf[0]==(char)PROXY_CONCHVERSION){

  39648.           /* don't break the lock if the host id doesn't match */

  39649.           if( 0!=memcmp(&tBuf[PROXY_HEADERLEN], myHostID, PROXY_HOSTIDLEN) ){

  39650.             return SQLITE_BUSY;

  39651.           }

  39652.         }else{

  39653.           /* don't break the lock on short read or a version mismatch */

  39654.           return SQLITE_BUSY;

  39655.         }

  39656.         usleep(10000000); /* wait 10 sec and try the lock again */

  39657.         continue; 

  39658.       }

  39659.       

  39660.       assert( nTries==3 );

  39661.       if( 0==proxyBreakConchLock(pFile, myHostID) ){

  39662.         rc = SQLITE_OK;

  39663.         if( lockType==EXCLUSIVE_LOCK ){

  39664.           rc = conchFile->pMethod->xLock((sqlite3_file*)conchFile, SHARED_LOCK);

  39665.         }

  39666.         if( !rc ){

  39667.           rc = conchFile->pMethod->xLock((sqlite3_file*)conchFile, lockType);

  39668.         }

  39669.       }

  39670.     }

  39671.   } while( rc==SQLITE_BUSY && nTries<3 );

  39672.   

  39673.   return rc;

  39674. }

  39675. 

  39676. /* Takes the conch by taking a shared lock and read the contents conch, if 

  39677. ** lockPath is non-NULL, the host ID and lock file path must match.  A NULL 

  39678. ** lockPath means that the lockPath in the conch file will be used if the 

  39679. ** host IDs match, or a new lock path will be generated automatically 

  39680. ** and written to the conch file.

  39681. */

  39682. static int proxyTakeConch(unixFile *pFile){

  39683.   proxyLockingContext *pCtx = (proxyLockingContext *)pFile->lockingContext; 

  39684.   

  39685.   if( pCtx->conchHeld!=0 ){

  39686.     return SQLITE_OK;

  39687.   }else{

  39688.     unixFile *conchFile = pCtx->conchFile;

  39689.     uuid_t myHostID;

  39690.     int pError = 0;

  39691.     char readBuf[PROXY_MAXCONCHLEN];

  39692.     char lockPath[MAXPATHLEN];

  39693.     char *tempLockPath = NULL;

  39694.     int rc = SQLITE_OK;

  39695.     int createConch = 0;

  39696.     int hostIdMatch = 0;

  39697.     int readLen = 0;

  39698.     int tryOldLockPath = 0;

  39699.     int forceNewLockPath = 0;

  39700.     

  39701.     OSTRACE(("TAKECONCH  %d for %s pid=%d\n", conchFile->h,

  39702.              (pCtx->lockProxyPath ? pCtx->lockProxyPath : ":auto:"),

  39703.              osGetpid(0)));

  39704. 

  39705.     rc = proxyGetHostID(myHostID, &pError);

  39706.     if( (rc&0xff)==SQLITE_IOERR ){

  39707.       storeLastErrno(pFile, pError);

  39708.       goto end_takeconch;

  39709.     }

  39710.     rc = proxyConchLock(pFile, myHostID, SHARED_LOCK);

  39711.     if( rc!=SQLITE_OK ){

  39712.       goto end_takeconch;

  39713.     }

  39714.     /* read the existing conch file */

  39715.     readLen = seekAndRead((unixFile*)conchFile, 0, readBuf, PROXY_MAXCONCHLEN);

  39716.     if( readLen<0 ){

  39717.       /* I/O error: lastErrno set by seekAndRead */

  39718.       storeLastErrno(pFile, conchFile->lastErrno);

  39719.       rc = SQLITE_IOERR_READ;

  39720.       goto end_takeconch;

  39721.     }else if( readLen<=(PROXY_HEADERLEN+PROXY_HOSTIDLEN) || 

  39722.              readBuf[0]!=(char)PROXY_CONCHVERSION ){

  39723.       /* a short read or version format mismatch means we need to create a new 

  39724.       ** conch file. 

  39725.       */

  39726.       createConch = 1;

  39727.     }

  39728.     /* if the host id matches and the lock path already exists in the conch

  39729.     ** we'll try to use the path there, if we can't open that path, we'll 

  39730.     ** retry with a new auto-generated path 

  39731.     */

  39732.     do { /* in case we need to try again for an :auto: named lock file */

  39733. 

  39734.       if( !createConch && !forceNewLockPath ){

  39735.         hostIdMatch = !memcmp(&readBuf[PROXY_HEADERLEN], myHostID, 

  39736.                                   PROXY_HOSTIDLEN);

  39737.         /* if the conch has data compare the contents */

  39738.         if( !pCtx->lockProxyPath ){

  39739.           /* for auto-named local lock file, just check the host ID and we'll

  39740.            ** use the local lock file path that's already in there

  39741.            */

  39742.           if( hostIdMatch ){

  39743.             size_t pathLen = (readLen - PROXY_PATHINDEX);

  39744.             

  39745.             if( pathLen>=MAXPATHLEN ){

  39746.               pathLen=MAXPATHLEN-1;

  39747.             }

  39748.             memcpy(lockPath, &readBuf[PROXY_PATHINDEX], pathLen);

  39749.             lockPath[pathLen] = 0;

  39750.             tempLockPath = lockPath;

  39751.             tryOldLockPath = 1;

  39752.             /* create a copy of the lock path if the conch is taken */

  39753.             goto end_takeconch;

  39754.           }

  39755.         }else if( hostIdMatch

  39756.                && !strncmp(pCtx->lockProxyPath, &readBuf[PROXY_PATHINDEX],

  39757.                            readLen-PROXY_PATHINDEX)

  39758.         ){

  39759.           /* conch host and lock path match */

  39760.           goto end_takeconch; 

  39761.         }

  39762.       }

  39763.       

  39764.       /* if the conch isn't writable and doesn't match, we can't take it */

  39765.       if( (conchFile->openFlags&O_RDWR) == 0 ){

  39766.         rc = SQLITE_BUSY;

  39767.         goto end_takeconch;

  39768.       }

  39769.       

  39770.       /* either the conch didn't match or we need to create a new one */

  39771.       if( !pCtx->lockProxyPath ){

  39772.         proxyGetLockPath(pCtx->dbPath, lockPath, MAXPATHLEN);

  39773.         tempLockPath = lockPath;

  39774.         /* create a copy of the lock path _only_ if the conch is taken */

  39775.       }

  39776.       

  39777.       /* update conch with host and path (this will fail if other process

  39778.       ** has a shared lock already), if the host id matches, use the big

  39779.       ** stick.

  39780.       */

  39781.       futimes(conchFile->h, NULL);

  39782.       if( hostIdMatch && !createConch ){

  39783.         if( conchFile->pInode && conchFile->pInode->nShared>1 ){

  39784.           /* We are trying for an exclusive lock but another thread in this

  39785.            ** same process is still holding a shared lock. */

  39786.           rc = SQLITE_BUSY;

  39787.         } else {          

  39788.           rc = proxyConchLock(pFile, myHostID, EXCLUSIVE_LOCK);

  39789.         }

  39790.       }else{

  39791.         rc = proxyConchLock(pFile, myHostID, EXCLUSIVE_LOCK);

  39792.       }

  39793.       if( rc==SQLITE_OK ){

  39794.         char writeBuffer[PROXY_MAXCONCHLEN];

  39795.         int writeSize = 0;

  39796.         

  39797.         writeBuffer[0] = (char)PROXY_CONCHVERSION;

  39798.         memcpy(&writeBuffer[PROXY_HEADERLEN], myHostID, PROXY_HOSTIDLEN);

  39799.         if( pCtx->lockProxyPath!=NULL ){

  39800.           strlcpy(&writeBuffer[PROXY_PATHINDEX], pCtx->lockProxyPath,

  39801.                   MAXPATHLEN);

  39802.         }else{

  39803.           strlcpy(&writeBuffer[PROXY_PATHINDEX], tempLockPath, MAXPATHLEN);

  39804.         }

  39805.         writeSize = PROXY_PATHINDEX + strlen(&writeBuffer[PROXY_PATHINDEX]);

  39806.         robust_ftruncate(conchFile->h, writeSize);

  39807.         rc = unixWrite((sqlite3_file *)conchFile, writeBuffer, writeSize, 0);

  39808.         full_fsync(conchFile->h,0,0);

  39809.         /* If we created a new conch file (not just updated the contents of a 

  39810.          ** valid conch file), try to match the permissions of the database 

  39811.          */

  39812.         if( rc==SQLITE_OK && createConch ){

  39813.           struct stat buf;

  39814.           int err = osFstat(pFile->h, &buf);

  39815.           if( err==0 ){

  39816.             mode_t cmode = buf.st_mode&(S_IRUSR|S_IWUSR | S_IRGRP|S_IWGRP |

  39817.                                         S_IROTH|S_IWOTH);

  39818.             /* try to match the database file R/W permissions, ignore failure */

  39819. #ifndef SQLITE_PROXY_DEBUG

  39820.             osFchmod(conchFile->h, cmode);

  39821. #else

  39822.             do{

  39823.               rc = osFchmod(conchFile->h, cmode);

  39824.             }while( rc==(-1) && errno==EINTR );

  39825.             if( rc!=0 ){

  39826.               int code = errno;

  39827.               fprintf(stderr, "fchmod %o FAILED with %d %s\n",

  39828.                       cmode, code, strerror(code));

  39829.             } else {

  39830.               fprintf(stderr, "fchmod %o SUCCEDED\n",cmode);

  39831.             }

  39832.           }else{

  39833.             int code = errno;

  39834.             fprintf(stderr, "STAT FAILED[%d] with %d %s\n", 

  39835.                     err, code, strerror(code));

  39836. #endif

  39837.           }

  39838.         }

  39839.       }

  39840.       conchFile->pMethod->xUnlock((sqlite3_file*)conchFile, SHARED_LOCK);

  39841.       

  39842.     end_takeconch:

  39843.       OSTRACE(("TRANSPROXY: CLOSE  %d\n", pFile->h));

  39844.       if( rc==SQLITE_OK && pFile->openFlags ){

  39845.         int fd;

  39846.         if( pFile->h>=0 ){

  39847.           robust_close(pFile, pFile->h, __LINE__);

  39848.         }

  39849.         pFile->h = -1;

  39850.         fd = robust_open(pCtx->dbPath, pFile->openFlags, 0);

  39851.         OSTRACE(("TRANSPROXY: OPEN  %d\n", fd));

  39852.         if( fd>=0 ){

  39853.           pFile->h = fd;

  39854.         }else{

  39855.           rc=SQLITE_CANTOPEN_BKPT; /* SQLITE_BUSY? proxyTakeConch called

  39856.            during locking */

  39857.         }

  39858.       }

  39859.       if( rc==SQLITE_OK && !pCtx->lockProxy ){

  39860.         char *path = tempLockPath ? tempLockPath : pCtx->lockProxyPath;

  39861.         rc = proxyCreateUnixFile(path, &pCtx->lockProxy, 1);

  39862.         if( rc!=SQLITE_OK && rc!=SQLITE_NOMEM && tryOldLockPath ){

  39863.           /* we couldn't create the proxy lock file with the old lock file path

  39864.            ** so try again via auto-naming 

  39865.            */

  39866.           forceNewLockPath = 1;

  39867.           tryOldLockPath = 0;

  39868.           continue; /* go back to the do {} while start point, try again */

  39869.         }

  39870.       }

  39871.       if( rc==SQLITE_OK ){

  39872.         /* Need to make a copy of path if we extracted the value

  39873.          ** from the conch file or the path was allocated on the stack

  39874.          */

  39875.         if( tempLockPath ){

  39876.           pCtx->lockProxyPath = sqlite3DbStrDup(0, tempLockPath);

  39877.           if( !pCtx->lockProxyPath ){

  39878.             rc = SQLITE_NOMEM_BKPT;

  39879.           }

  39880.         }

  39881.       }

  39882.       if( rc==SQLITE_OK ){

  39883.         pCtx->conchHeld = 1;

  39884.         

  39885.         if( pCtx->lockProxy->pMethod == &afpIoMethods ){

  39886.           afpLockingContext *afpCtx;

  39887.           afpCtx = (afpLockingContext *)pCtx->lockProxy->lockingContext;

  39888.           afpCtx->dbPath = pCtx->lockProxyPath;

  39889.         }

  39890.       } else {

  39891.         conchFile->pMethod->xUnlock((sqlite3_file*)conchFile, NO_LOCK);

  39892.       }

  39893.       OSTRACE(("TAKECONCH  %d %s\n", conchFile->h,

  39894.                rc==SQLITE_OK?"ok":"failed"));

  39895.       return rc;

  39896.     } while (1); /* in case we need to retry the :auto: lock file - 

  39897.                  ** we should never get here except via the 'continue' call. */

  39898.   }

  39899. }

  39900. 

  39901. /*

  39902. ** If pFile holds a lock on a conch file, then release that lock.

  39903. */

  39904. static int proxyReleaseConch(unixFile *pFile){

  39905.   int rc = SQLITE_OK;         /* Subroutine return code */

  39906.   proxyLockingContext *pCtx;  /* The locking context for the proxy lock */

  39907.   unixFile *conchFile;        /* Name of the conch file */

  39908. 

  39909.   pCtx = (proxyLockingContext *)pFile->lockingContext;

  39910.   conchFile = pCtx->conchFile;

  39911.   OSTRACE(("RELEASECONCH  %d for %s pid=%d\n", conchFile->h,

  39912.            (pCtx->lockProxyPath ? pCtx->lockProxyPath : ":auto:"), 

  39913.            osGetpid(0)));

  39914.   if( pCtx->conchHeld>0 ){

  39915.     rc = conchFile->pMethod->xUnlock((sqlite3_file*)conchFile, NO_LOCK);

  39916.   }

  39917.   pCtx->conchHeld = 0;

  39918.   OSTRACE(("RELEASECONCH  %d %s\n", conchFile->h,

  39919.            (rc==SQLITE_OK ? "ok" : "failed")));

  39920.   return rc;

  39921. }

  39922. 

  39923. /*

  39924. ** Given the name of a database file, compute the name of its conch file.

  39925. ** Store the conch filename in memory obtained from sqlite3_malloc64().

  39926. ** Make *pConchPath point to the new name.  Return SQLITE_OK on success

  39927. ** or SQLITE_NOMEM if unable to obtain memory.

  39928. **

  39929. ** The caller is responsible for ensuring that the allocated memory

  39930. ** space is eventually freed.

  39931. **

  39932. ** *pConchPath is set to NULL if a memory allocation error occurs.

  39933. */

  39934. static int proxyCreateConchPathname(char *dbPath, char **pConchPath){

  39935.   int i;                        /* Loop counter */

  39936.   int len = (int)strlen(dbPath); /* Length of database filename - dbPath */

  39937.   char *conchPath;              /* buffer in which to construct conch name */

  39938. 

  39939.   /* Allocate space for the conch filename and initialize the name to

  39940.   ** the name of the original database file. */  

  39941.   *pConchPath = conchPath = (char *)sqlite3_malloc64(len + 8);

  39942.   if( conchPath==0 ){

  39943.     return SQLITE_NOMEM_BKPT;

  39944.   }

  39945.   memcpy(conchPath, dbPath, len+1);

  39946.   

  39947.   /* now insert a "." before the last / character */

  39948.   for( i=(len-1); i>=0; i-- ){

  39949.     if( conchPath[i]=='/' ){

  39950.       i++;

  39951.       break;

  39952.     }

  39953.   }

  39954.   conchPath[i]='.';

  39955.   while ( i<len ){

  39956.     conchPath[i+1]=dbPath[i];

  39957.     i++;

  39958.   }

  39959. 

  39960.   /* append the "-conch" suffix to the file */

  39961.   memcpy(&conchPath[i+1], "-conch", 7);

  39962.   assert( (int)strlen(conchPath) == len+7 );

  39963. 

  39964.   return SQLITE_OK;

  39965. }

  39966. 

  39967. 

  39968. /* Takes a fully configured proxy locking-style unix file and switches

  39969. ** the local lock file path 

  39970. */

  39971. static int switchLockProxyPath(unixFile *pFile, const char *path) {

  39972.   proxyLockingContext *pCtx = (proxyLockingContext*)pFile->lockingContext;

  39973.   char *oldPath = pCtx->lockProxyPath;

  39974.   int rc = SQLITE_OK;

  39975. 

  39976.   if( pFile->eFileLock!=NO_LOCK ){

  39977.     return SQLITE_BUSY;

  39978.   }  

  39979. 

  39980.   /* nothing to do if the path is NULL, :auto: or matches the existing path */

  39981.   if( !path || path[0]=='\0' || !strcmp(path, ":auto:") ||

  39982.     (oldPath && !strncmp(oldPath, path, MAXPATHLEN)) ){

  39983.     return SQLITE_OK;

  39984.   }else{

  39985.     unixFile *lockProxy = pCtx->lockProxy;

  39986.     pCtx->lockProxy=NULL;

  39987.     pCtx->conchHeld = 0;

  39988.     if( lockProxy!=NULL ){

  39989.       rc=lockProxy->pMethod->xClose((sqlite3_file *)lockProxy);

  39990.       if( rc ) return rc;

  39991.       sqlite3_free(lockProxy);

  39992.     }

  39993.     sqlite3_free(oldPath);

  39994.     pCtx->lockProxyPath = sqlite3DbStrDup(0, path);

  39995.   }

  39996.   

  39997.   return rc;

  39998. }

  39999. 

  40000. /*

  40001. ** pFile is a file that has been opened by a prior xOpen call.  dbPath

  40002. ** is a string buffer at least MAXPATHLEN+1 characters in size.

  40003. **

  40004. ** This routine find the filename associated with pFile and writes it

  40005. ** int dbPath.

  40006. */

  40007. static int proxyGetDbPathForUnixFile(unixFile *pFile, char *dbPath){

  40008. #if defined(__APPLE__)

  40009.   if( pFile->pMethod == &afpIoMethods ){

  40010.     /* afp style keeps a reference to the db path in the filePath field 

  40011.     ** of the struct */

  40012.     assert( (int)strlen((char*)pFile->lockingContext)<=MAXPATHLEN );

  40013.     strlcpy(dbPath, ((afpLockingContext *)pFile->lockingContext)->dbPath,

  40014.             MAXPATHLEN);

  40015.   } else

  40016. #endif

  40017.   if( pFile->pMethod == &dotlockIoMethods ){

  40018.     /* dot lock style uses the locking context to store the dot lock

  40019.     ** file path */

  40020.     int len = strlen((char *)pFile->lockingContext) - strlen(DOTLOCK_SUFFIX);

  40021.     memcpy(dbPath, (char *)pFile->lockingContext, len + 1);

  40022.   }else{

  40023.     /* all other styles use the locking context to store the db file path */

  40024.     assert( strlen((char*)pFile->lockingContext)<=MAXPATHLEN );

  40025.     strlcpy(dbPath, (char *)pFile->lockingContext, MAXPATHLEN);

  40026.   }

  40027.   return SQLITE_OK;

  40028. }

  40029. 

  40030. /*

  40031. ** Takes an already filled in unix file and alters it so all file locking 

  40032. ** will be performed on the local proxy lock file.  The following fields

  40033. ** are preserved in the locking context so that they can be restored and 

  40034. ** the unix structure properly cleaned up at close time:

  40035. **  ->lockingContext

  40036. **  ->pMethod

  40037. */

  40038. static int proxyTransformUnixFile(unixFile *pFile, const char *path) {

  40039.   proxyLockingContext *pCtx;

  40040.   char dbPath[MAXPATHLEN+1];       /* Name of the database file */

  40041.   char *lockPath=NULL;

  40042.   int rc = SQLITE_OK;

  40043.   

  40044.   if( pFile->eFileLock!=NO_LOCK ){

  40045.     return SQLITE_BUSY;

  40046.   }

  40047.   proxyGetDbPathForUnixFile(pFile, dbPath);

  40048.   if( !path || path[0]=='\0' || !strcmp(path, ":auto:") ){

  40049.     lockPath=NULL;

  40050.   }else{

  40051.     lockPath=(char *)path;

  40052.   }

  40053.   

  40054.   OSTRACE(("TRANSPROXY  %d for %s pid=%d\n", pFile->h,

  40055.            (lockPath ? lockPath : ":auto:"), osGetpid(0)));

  40056. 

  40057.   pCtx = sqlite3_malloc64( sizeof(*pCtx) );

  40058.   if( pCtx==0 ){

  40059.     return SQLITE_NOMEM_BKPT;

  40060.   }

  40061.   memset(pCtx, 0, sizeof(*pCtx));

  40062. 

  40063.   rc = proxyCreateConchPathname(dbPath, &pCtx->conchFilePath);

  40064.   if( rc==SQLITE_OK ){

  40065.     rc = proxyCreateUnixFile(pCtx->conchFilePath, &pCtx->conchFile, 0);

  40066.     if( rc==SQLITE_CANTOPEN && ((pFile->openFlags&O_RDWR) == 0) ){

  40067.       /* if (a) the open flags are not O_RDWR, (b) the conch isn't there, and

  40068.       ** (c) the file system is read-only, then enable no-locking access.

  40069.       ** Ugh, since O_RDONLY==0x0000 we test for !O_RDWR since unixOpen asserts

  40070.       ** that openFlags will have only one of O_RDONLY or O_RDWR.

  40071.       */

  40072.       struct statfs fsInfo;

  40073.       struct stat conchInfo;

  40074.       int goLockless = 0;

  40075. 

  40076.       if( osStat(pCtx->conchFilePath, &conchInfo) == -1 ) {

  40077.         int err = errno;

  40078.         if( (err==ENOENT) && (statfs(dbPath, &fsInfo) != -1) ){

  40079.           goLockless = (fsInfo.f_flags&MNT_RDONLY) == MNT_RDONLY;

  40080.         }

  40081.       }

  40082.       if( goLockless ){

  40083.         pCtx->conchHeld = -1; /* read only FS/ lockless */

  40084.         rc = SQLITE_OK;

  40085.       }

  40086.     }

  40087.   }  

  40088.   if( rc==SQLITE_OK && lockPath ){

  40089.     pCtx->lockProxyPath = sqlite3DbStrDup(0, lockPath);

  40090.   }

  40091. 

  40092.   if( rc==SQLITE_OK ){

  40093.     pCtx->dbPath = sqlite3DbStrDup(0, dbPath);

  40094.     if( pCtx->dbPath==NULL ){

  40095.       rc = SQLITE_NOMEM_BKPT;

  40096.     }

  40097.   }

  40098.   if( rc==SQLITE_OK ){

  40099.     /* all memory is allocated, proxys are created and assigned, 

  40100.     ** switch the locking context and pMethod then return.

  40101.     */

  40102.     pCtx->oldLockingContext = pFile->lockingContext;

  40103.     pFile->lockingContext = pCtx;

  40104.     pCtx->pOldMethod = pFile->pMethod;

  40105.     pFile->pMethod = &proxyIoMethods;

  40106.   }else{

  40107.     if( pCtx->conchFile ){ 

  40108.       pCtx->conchFile->pMethod->xClose((sqlite3_file *)pCtx->conchFile);

  40109.       sqlite3_free(pCtx->conchFile);

  40110.     }

  40111.     sqlite3DbFree(0, pCtx->lockProxyPath);

  40112.     sqlite3_free(pCtx->conchFilePath); 

  40113.     sqlite3_free(pCtx);

  40114.   }

  40115.   OSTRACE(("TRANSPROXY  %d %s\n", pFile->h,

  40116.            (rc==SQLITE_OK ? "ok" : "failed")));

  40117.   return rc;

  40118. }

  40119. 

  40120. 

  40121. /*

  40122. ** This routine handles sqlite3_file_control() calls that are specific

  40123. ** to proxy locking.

  40124. */

  40125. static int proxyFileControl(sqlite3_file *id, int op, void *pArg){

  40126.   switch( op ){

  40127.     case SQLITE_FCNTL_GET_LOCKPROXYFILE: {

  40128.       unixFile *pFile = (unixFile*)id;

  40129.       if( pFile->pMethod == &proxyIoMethods ){

  40130.         proxyLockingContext *pCtx = (proxyLockingContext*)pFile->lockingContext;

  40131.         proxyTakeConch(pFile);

  40132.         if( pCtx->lockProxyPath ){

  40133.           *(const char **)pArg = pCtx->lockProxyPath;

  40134.         }else{

  40135.           *(const char **)pArg = ":auto: (not held)";

  40136.         }

  40137.       } else {

  40138.         *(const char **)pArg = NULL;

  40139.       }

  40140.       return SQLITE_OK;

  40141.     }

  40142.     case SQLITE_FCNTL_SET_LOCKPROXYFILE: {

  40143.       unixFile *pFile = (unixFile*)id;

  40144.       int rc = SQLITE_OK;

  40145.       int isProxyStyle = (pFile->pMethod == &proxyIoMethods);

  40146.       if( pArg==NULL || (const char *)pArg==0 ){

  40147.         if( isProxyStyle ){

  40148.           /* turn off proxy locking - not supported.  If support is added for

  40149.           ** switching proxy locking mode off then it will need to fail if

  40150.           ** the journal mode is WAL mode. 

  40151.           */

  40152.           rc = SQLITE_ERROR /*SQLITE_PROTOCOL? SQLITE_MISUSE?*/;

  40153.         }else{

  40154.           /* turn off proxy locking - already off - NOOP */

  40155.           rc = SQLITE_OK;

  40156.         }

  40157.       }else{

  40158.         const char *proxyPath = (const char *)pArg;

  40159.         if( isProxyStyle ){

  40160.           proxyLockingContext *pCtx = 

  40161.             (proxyLockingContext*)pFile->lockingContext;

  40162.           if( !strcmp(pArg, ":auto:") 

  40163.            || (pCtx->lockProxyPath &&

  40164.                !strncmp(pCtx->lockProxyPath, proxyPath, MAXPATHLEN))

  40165.           ){

  40166.             rc = SQLITE_OK;

  40167.           }else{

  40168.             rc = switchLockProxyPath(pFile, proxyPath);

  40169.           }

  40170.         }else{

  40171.           /* turn on proxy file locking */

  40172.           rc = proxyTransformUnixFile(pFile, proxyPath);

  40173.         }

  40174.       }

  40175.       return rc;

  40176.     }

  40177.     default: {

  40178.       assert( 0 );  /* The call assures that only valid opcodes are sent */

  40179.     }

  40180.   }

  40181.   /*NOTREACHED*/

  40182.   return SQLITE_ERROR;

  40183. }

  40184. 

  40185. /*

  40186. ** Within this division (the proxying locking implementation) the procedures

  40187. ** above this point are all utilities.  The lock-related methods of the

  40188. ** proxy-locking sqlite3_io_method object follow.

  40189. */

  40190. 

  40191. 

  40192. /*

  40193. ** This routine checks if there is a RESERVED lock held on the specified

  40194. ** file by this or any other process. If such a lock is held, set *pResOut

  40195. ** to a non-zero value otherwise *pResOut is set to zero.  The return value

  40196. ** is set to SQLITE_OK unless an I/O error occurs during lock checking.

  40197. */

  40198. static int proxyCheckReservedLock(sqlite3_file *id, int *pResOut) {

  40199.   unixFile *pFile = (unixFile*)id;

  40200.   int rc = proxyTakeConch(pFile);

  40201.   if( rc==SQLITE_OK ){

  40202.     proxyLockingContext *pCtx = (proxyLockingContext *)pFile->lockingContext;

  40203.     if( pCtx->conchHeld>0 ){

  40204.       unixFile *proxy = pCtx->lockProxy;

  40205.       return proxy->pMethod->xCheckReservedLock((sqlite3_file*)proxy, pResOut);

  40206.     }else{ /* conchHeld < 0 is lockless */

  40207.       pResOut=0;

  40208.     }

  40209.   }

  40210.   return rc;

  40211. }

  40212. 

  40213. /*

  40214. ** Lock the file with the lock specified by parameter eFileLock - one

  40215. ** of the following:

  40216. **

  40217. **     (1) SHARED_LOCK

  40218. **     (2) RESERVED_LOCK

  40219. **     (3) PENDING_LOCK

  40220. **     (4) EXCLUSIVE_LOCK

  40221. **

  40222. ** Sometimes when requesting one lock state, additional lock states

  40223. ** are inserted in between.  The locking might fail on one of the later

  40224. ** transitions leaving the lock state different from what it started but

  40225. ** still short of its goal.  The following chart shows the allowed

  40226. ** transitions and the inserted intermediate states:

  40227. **

  40228. **    UNLOCKED -> SHARED

  40229. **    SHARED -> RESERVED

  40230. **    SHARED -> (PENDING) -> EXCLUSIVE

  40231. **    RESERVED -> (PENDING) -> EXCLUSIVE

  40232. **    PENDING -> EXCLUSIVE

  40233. **

  40234. ** This routine will only increase a lock.  Use the sqlite3OsUnlock()

  40235. ** routine to lower a locking level.

  40236. */

  40237. static int proxyLock(sqlite3_file *id, int eFileLock) {

  40238.   unixFile *pFile = (unixFile*)id;

  40239.   int rc = proxyTakeConch(pFile);

  40240.   if( rc==SQLITE_OK ){

  40241.     proxyLockingContext *pCtx = (proxyLockingContext *)pFile->lockingContext;

  40242.     if( pCtx->conchHeld>0 ){

  40243.       unixFile *proxy = pCtx->lockProxy;

  40244.       rc = proxy->pMethod->xLock((sqlite3_file*)proxy, eFileLock);

  40245.       pFile->eFileLock = proxy->eFileLock;

  40246.     }else{

  40247.       /* conchHeld < 0 is lockless */

  40248.     }

  40249.   }

  40250.   return rc;

  40251. }

  40252. 

  40253. 

  40254. /*

  40255. ** Lower the locking level on file descriptor pFile to eFileLock.  eFileLock

  40256. ** must be either NO_LOCK or SHARED_LOCK.

  40257. **

  40258. ** If the locking level of the file descriptor is already at or below

  40259. ** the requested locking level, this routine is a no-op.

  40260. */

  40261. static int proxyUnlock(sqlite3_file *id, int eFileLock) {

  40262.   unixFile *pFile = (unixFile*)id;

  40263.   int rc = proxyTakeConch(pFile);

  40264.   if( rc==SQLITE_OK ){

  40265.     proxyLockingContext *pCtx = (proxyLockingContext *)pFile->lockingContext;

  40266.     if( pCtx->conchHeld>0 ){

  40267.       unixFile *proxy = pCtx->lockProxy;

  40268.       rc = proxy->pMethod->xUnlock((sqlite3_file*)proxy, eFileLock);

  40269.       pFile->eFileLock = proxy->eFileLock;

  40270.     }else{

  40271.       /* conchHeld < 0 is lockless */

  40272.     }

  40273.   }

  40274.   return rc;

  40275. }

  40276. 

  40277. /*

  40278. ** Close a file that uses proxy locks.

  40279. */

  40280. static int proxyClose(sqlite3_file *id) {

  40281.   if( ALWAYS(id) ){

  40282.     unixFile *pFile = (unixFile*)id;

  40283.     proxyLockingContext *pCtx = (proxyLockingContext *)pFile->lockingContext;

  40284.     unixFile *lockProxy = pCtx->lockProxy;

  40285.     unixFile *conchFile = pCtx->conchFile;

  40286.     int rc = SQLITE_OK;

  40287.     

  40288.     if( lockProxy ){

  40289.       rc = lockProxy->pMethod->xUnlock((sqlite3_file*)lockProxy, NO_LOCK);

  40290.       if( rc ) return rc;

  40291.       rc = lockProxy->pMethod->xClose((sqlite3_file*)lockProxy);

  40292.       if( rc ) return rc;

  40293.       sqlite3_free(lockProxy);

  40294.       pCtx->lockProxy = 0;

  40295.     }

  40296.     if( conchFile ){

  40297.       if( pCtx->conchHeld ){

  40298.         rc = proxyReleaseConch(pFile);

  40299.         if( rc ) return rc;

  40300.       }

  40301.       rc = conchFile->pMethod->xClose((sqlite3_file*)conchFile);

  40302.       if( rc ) return rc;

  40303.       sqlite3_free(conchFile);

  40304.     }

  40305.     sqlite3DbFree(0, pCtx->lockProxyPath);

  40306.     sqlite3_free(pCtx->conchFilePath);

  40307.     sqlite3DbFree(0, pCtx->dbPath);

  40308.     /* restore the original locking context and pMethod then close it */

  40309.     pFile->lockingContext = pCtx->oldLockingContext;

  40310.     pFile->pMethod = pCtx->pOldMethod;

  40311.     sqlite3_free(pCtx);

  40312.     return pFile->pMethod->xClose(id);

  40313.   }

  40314.   return SQLITE_OK;

  40315. }

  40316. 

  40317. 

  40318. 

  40319. #endif /* defined(__APPLE__) && SQLITE_ENABLE_LOCKING_STYLE */

  40320. /*

  40321. ** The proxy locking style is intended for use with AFP filesystems.

  40322. ** And since AFP is only supported on MacOSX, the proxy locking is also

  40323. ** restricted to MacOSX.

  40324. ** 

  40325. **

  40326. ******************* End of the proxy lock implementation **********************

  40327. ******************************************************************************/

  40328. 

  40329. /*

  40330. ** Initialize the operating system interface.

  40331. **

  40332. ** This routine registers all VFS implementations for unix-like operating

  40333. ** systems.  This routine, and the sqlite3_os_end() routine that follows,

  40334. ** should be the only routines in this file that are visible from other

  40335. ** files.

  40336. **

  40337. ** This routine is called once during SQLite initialization and by a

  40338. ** single thread.  The memory allocation and mutex subsystems have not

  40339. ** necessarily been initialized when this routine is called, and so they

  40340. ** should not be used.

  40341. */

  40342. SQLITE_API int sqlite3_os_init(void){ 

  40343.   /* 

  40344.   ** The following macro defines an initializer for an sqlite3_vfs object.

  40345.   ** The name of the VFS is NAME.  The pAppData is a pointer to a pointer

  40346.   ** to the "finder" function.  (pAppData is a pointer to a pointer because

  40347.   ** silly C90 rules prohibit a void* from being cast to a function pointer

  40348.   ** and so we have to go through the intermediate pointer to avoid problems

  40349.   ** when compiling with -pedantic-errors on GCC.)

  40350.   **

  40351.   ** The FINDER parameter to this macro is the name of the pointer to the

  40352.   ** finder-function.  The finder-function returns a pointer to the

  40353.   ** sqlite_io_methods object that implements the desired locking

  40354.   ** behaviors.  See the division above that contains the IOMETHODS

  40355.   ** macro for addition information on finder-functions.

  40356.   **

  40357.   ** Most finders simply return a pointer to a fixed sqlite3_io_methods

  40358.   ** object.  But the "autolockIoFinder" available on MacOSX does a little

  40359.   ** more than that; it looks at the filesystem type that hosts the 

  40360.   ** database file and tries to choose an locking method appropriate for

  40361.   ** that filesystem time.

  40362.   */

  40363.   #define UNIXVFS(VFSNAME, FINDER) {                        \

  40364.     3,                    /* iVersion */                    \

  40365.     sizeof(unixFile),     /* szOsFile */                    \

  40366.     MAX_PATHNAME,         /* mxPathname */                  \

  40367.     0,                    /* pNext */                       \

  40368.     VFSNAME,              /* zName */                       \

  40369.     (void*)&FINDER,       /* pAppData */                    \

  40370.     unixOpen,             /* xOpen */                       \

  40371.     unixDelete,           /* xDelete */                     \

  40372.     unixAccess,           /* xAccess */                     \

  40373.     unixFullPathname,     /* xFullPathname */               \

  40374.     unixDlOpen,           /* xDlOpen */                     \

  40375.     unixDlError,          /* xDlError */                    \

  40376.     unixDlSym,            /* xDlSym */                      \

  40377.     unixDlClose,          /* xDlClose */                    \

  40378.     unixRandomness,       /* xRandomness */                 \

  40379.     unixSleep,            /* xSleep */                      \

  40380.     unixCurrentTime,      /* xCurrentTime */                \

  40381.     unixGetLastError,     /* xGetLastError */               \

  40382.     unixCurrentTimeInt64, /* xCurrentTimeInt64 */           \

  40383.     unixSetSystemCall,    /* xSetSystemCall */              \

  40384.     unixGetSystemCall,    /* xGetSystemCall */              \

  40385.     unixNextSystemCall,   /* xNextSystemCall */             \

  40386.   }

  40387. 

  40388.   /*

  40389.   ** All default VFSes for unix are contained in the following array.

  40390.   **

  40391.   ** Note that the sqlite3_vfs.pNext field of the VFS object is modified

  40392.   ** by the SQLite core when the VFS is registered.  So the following

  40393.   ** array cannot be const.

  40394.   */

  40395.   static sqlite3_vfs aVfs[] = {

  40396. #if SQLITE_ENABLE_LOCKING_STYLE && defined(__APPLE__)

  40397.     UNIXVFS("unix",          autolockIoFinder ),

  40398. #elif OS_VXWORKS

  40399.     UNIXVFS("unix",          vxworksIoFinder ),

  40400. #else

  40401.     UNIXVFS("unix",          posixIoFinder ),

  40402. #endif

  40403.     UNIXVFS("unix-none",     nolockIoFinder ),

  40404.     UNIXVFS("unix-dotfile",  dotlockIoFinder ),

  40405.     UNIXVFS("unix-excl",     posixIoFinder ),

  40406. #if OS_VXWORKS

  40407.     UNIXVFS("unix-namedsem", semIoFinder ),

  40408. #endif

  40409. #if SQLITE_ENABLE_LOCKING_STYLE || OS_VXWORKS

  40410.     UNIXVFS("unix-posix",    posixIoFinder ),

  40411. #endif

  40412. #if SQLITE_ENABLE_LOCKING_STYLE

  40413.     UNIXVFS("unix-flock",    flockIoFinder ),

  40414. #endif

  40415. #if SQLITE_ENABLE_LOCKING_STYLE && defined(__APPLE__)

  40416.     UNIXVFS("unix-afp",      afpIoFinder ),

  40417.     UNIXVFS("unix-nfs",      nfsIoFinder ),

  40418.     UNIXVFS("unix-proxy",    proxyIoFinder ),

  40419. #endif

  40420.   };

  40421.   unsigned int i;          /* Loop counter */

  40422. 

  40423.   /* Double-check that the aSyscall[] array has been constructed

  40424.   ** correctly.  See ticket [bb3a86e890c8e96ab] */

  40425.   assert( ArraySize(aSyscall)==29 );

  40426. 

  40427.   /* Register all VFSes defined in the aVfs[] array */

  40428.   for(i=0; i<(sizeof(aVfs)/sizeof(sqlite3_vfs)); i++){

  40429.     sqlite3_vfs_register(&aVfs[i], i==0);

  40430.   }

  40431.   unixBigLock = sqlite3MutexAlloc(SQLITE_MUTEX_STATIC_VFS1);

  40432.   return SQLITE_OK; 

  40433. }

  40434. 

  40435. /*

  40436. ** Shutdown the operating system interface.

  40437. **

  40438. ** Some operating systems might need to do some cleanup in this routine,

  40439. ** to release dynamically allocated objects.  But not on unix.

  40440. ** This routine is a no-op for unix.

  40441. */

  40442. SQLITE_API int sqlite3_os_end(void){ 

  40443.   unixBigLock = 0;

  40444.   return SQLITE_OK; 

  40445. }

  40446.  

  40447. #endif /* SQLITE_OS_UNIX */

  40448. 

  40449. /************** End of os_unix.c *********************************************/

  40450. /************** Begin file os_win.c ******************************************/

  40451. /*

  40452. ** 2004 May 22

  40453. **

  40454. ** The author disclaims copyright to this source code.  In place of

  40455. ** a legal notice, here is a blessing:

  40456. **

  40457. **    May you do good and not evil.

  40458. **    May you find forgiveness for yourself and forgive others.

  40459. **    May you share freely, never taking more than you give.

  40460. **

  40461. ******************************************************************************

  40462. **

  40463. ** This file contains code that is specific to Windows.

  40464. */

  40465. /* #include "sqliteInt.h" */

  40466. #if SQLITE_OS_WIN               /* This file is used for Windows only */

  40467. 

  40468. /*

  40469. ** Include code that is common to all os_*.c files

  40470. */

  40471. /************** Include os_common.h in the middle of os_win.c ****************/

  40472. /************** Begin file os_common.h ***************************************/

  40473. /*

  40474. ** 2004 May 22

  40475. **

  40476. ** The author disclaims copyright to this source code.  In place of

  40477. ** a legal notice, here is a blessing:

  40478. **

  40479. **    May you do good and not evil.

  40480. **    May you find forgiveness for yourself and forgive others.

  40481. **    May you share freely, never taking more than you give.

  40482. **

  40483. ******************************************************************************

  40484. **

  40485. ** This file contains macros and a little bit of code that is common to

  40486. ** all of the platform-specific files (os_*.c) and is #included into those

  40487. ** files.

  40488. **

  40489. ** This file should be #included by the os_*.c files only.  It is not a

  40490. ** general purpose header file.

  40491. */

  40492. #ifndef _OS_COMMON_H_

  40493. #define _OS_COMMON_H_

  40494. 

  40495. /*

  40496. ** At least two bugs have slipped in because we changed the MEMORY_DEBUG

  40497. ** macro to SQLITE_DEBUG and some older makefiles have not yet made the

  40498. ** switch.  The following code should catch this problem at compile-time.

  40499. */

  40500. #ifdef MEMORY_DEBUG

  40501. # error "The MEMORY_DEBUG macro is obsolete.  Use SQLITE_DEBUG instead."

  40502. #endif

  40503. 

  40504. /*

  40505. ** Macros for performance tracing.  Normally turned off.  Only works

  40506. ** on i486 hardware.

  40507. */

  40508. #ifdef SQLITE_PERFORMANCE_TRACE

  40509. 

  40510. /*

  40511. ** hwtime.h contains inline assembler code for implementing

  40512. ** high-performance timing routines.

  40513. */

  40514. /************** Include hwtime.h in the middle of os_common.h ****************/

  40515. /************** Begin file hwtime.h ******************************************/

  40516. /*

  40517. ** 2008 May 27

  40518. **

  40519. ** The author disclaims copyright to this source code.  In place of

  40520. ** a legal notice, here is a blessing:

  40521. **

  40522. **    May you do good and not evil.

  40523. **    May you find forgiveness for yourself and forgive others.

  40524. **    May you share freely, never taking more than you give.

  40525. **

  40526. ******************************************************************************

  40527. **

  40528. ** This file contains inline asm code for retrieving "high-performance"

  40529. ** counters for x86 class CPUs.

  40530. */

  40531. #ifndef SQLITE_HWTIME_H

  40532. #define SQLITE_HWTIME_H

  40533. 

  40534. /*

  40535. ** The following routine only works on pentium-class (or newer) processors.

  40536. ** It uses the RDTSC opcode to read the cycle count value out of the

  40537. ** processor and returns that value.  This can be used for high-res

  40538. ** profiling.

  40539. */

  40540. #if (defined(__GNUC__) || defined(_MSC_VER)) && \

  40541.       (defined(i386) || defined(__i386__) || defined(_M_IX86))

  40542. 

  40543.   #if defined(__GNUC__)

  40544. 

  40545.   __inline__ sqlite_uint64 sqlite3Hwtime(void){

  40546.      unsigned int lo, hi;

  40547.      __asm__ __volatile__ ("rdtsc" : "=a" (lo), "=d" (hi));

  40548.      return (sqlite_uint64)hi << 32 | lo;

  40549.   }

  40550. 

  40551.   #elif defined(_MSC_VER)

  40552. 

  40553.   __declspec(naked) __inline sqlite_uint64 __cdecl sqlite3Hwtime(void){

  40554.      __asm {

  40555.         rdtsc

  40556.         ret       ; return value at EDX:EAX

  40557.      }

  40558.   }

  40559. 

  40560.   #endif

  40561. 

  40562. #elif (defined(__GNUC__) && defined(__x86_64__))

  40563. 

  40564.   __inline__ sqlite_uint64 sqlite3Hwtime(void){

  40565.       unsigned long val;

  40566.       __asm__ __volatile__ ("rdtsc" : "=A" (val));

  40567.       return val;

  40568.   }

  40569.  

  40570. #elif (defined(__GNUC__) && defined(__ppc__))

  40571. 

  40572.   __inline__ sqlite_uint64 sqlite3Hwtime(void){

  40573.       unsigned long long retval;

  40574.       unsigned long junk;

  40575.       __asm__ __volatile__ ("\n\

  40576.           1:      mftbu   %1\n\

  40577.                   mftb    %L0\n\

  40578.                   mftbu   %0\n\

  40579.                   cmpw    %0,%1\n\

  40580.                   bne     1b"

  40581.                   : "=r" (retval), "=r" (junk));

  40582.       return retval;

  40583.   }

  40584. 

  40585. #else

  40586. 

  40587.   #error Need implementation of sqlite3Hwtime() for your platform.

  40588. 

  40589.   /*

  40590.   ** To compile without implementing sqlite3Hwtime() for your platform,

  40591.   ** you can remove the above #error and use the following

  40592.   ** stub function.  You will lose timing support for many

  40593.   ** of the debugging and testing utilities, but it should at

  40594.   ** least compile and run.

  40595.   */

  40596. SQLITE_PRIVATE   sqlite_uint64 sqlite3Hwtime(void){ return ((sqlite_uint64)0); }

  40597. 

  40598. #endif

  40599. 

  40600. #endif /* !defined(SQLITE_HWTIME_H) */

  40601. 

  40602. /************** End of hwtime.h **********************************************/

  40603. /************** Continuing where we left off in os_common.h ******************/

  40604. 

  40605. static sqlite_uint64 g_start;

  40606. static sqlite_uint64 g_elapsed;

  40607. #define TIMER_START       g_start=sqlite3Hwtime()

  40608. #define TIMER_END         g_elapsed=sqlite3Hwtime()-g_start

  40609. #define TIMER_ELAPSED     g_elapsed

  40610. #else

  40611. #define TIMER_START

  40612. #define TIMER_END

  40613. #define TIMER_ELAPSED     ((sqlite_uint64)0)

  40614. #endif

  40615. 

  40616. /*

  40617. ** If we compile with the SQLITE_TEST macro set, then the following block

  40618. ** of code will give us the ability to simulate a disk I/O error.  This

  40619. ** is used for testing the I/O recovery logic.

  40620. */

  40621. #if defined(SQLITE_TEST)

  40622. SQLITE_API extern int sqlite3_io_error_hit;

  40623. SQLITE_API extern int sqlite3_io_error_hardhit;

  40624. SQLITE_API extern int sqlite3_io_error_pending;

  40625. SQLITE_API extern int sqlite3_io_error_persist;

  40626. SQLITE_API extern int sqlite3_io_error_benign;

  40627. SQLITE_API extern int sqlite3_diskfull_pending;

  40628. SQLITE_API extern int sqlite3_diskfull;

  40629. #define SimulateIOErrorBenign(X) sqlite3_io_error_benign=(X)

  40630. #define SimulateIOError(CODE)  \

  40631.   if( (sqlite3_io_error_persist && sqlite3_io_error_hit) \

  40632.        || sqlite3_io_error_pending-- == 1 )  \

  40633.               { local_ioerr(); CODE; }

  40634. static void local_ioerr(){

  40635.   IOTRACE(("IOERR\n"));

  40636.   sqlite3_io_error_hit++;

  40637.   if( !sqlite3_io_error_benign ) sqlite3_io_error_hardhit++;

  40638. }

  40639. #define SimulateDiskfullError(CODE) \

  40640.    if( sqlite3_diskfull_pending ){ \

  40641.      if( sqlite3_diskfull_pending == 1 ){ \

  40642.        local_ioerr(); \

  40643.        sqlite3_diskfull = 1; \

  40644.        sqlite3_io_error_hit = 1; \

  40645.        CODE; \

  40646.      }else{ \

  40647.        sqlite3_diskfull_pending--; \

  40648.      } \

  40649.    }

  40650. #else

  40651. #define SimulateIOErrorBenign(X)

  40652. #define SimulateIOError(A)

  40653. #define SimulateDiskfullError(A)

  40654. #endif /* defined(SQLITE_TEST) */

  40655. 

  40656. /*

  40657. ** When testing, keep a count of the number of open files.

  40658. */

  40659. #if defined(SQLITE_TEST)

  40660. SQLITE_API extern int sqlite3_open_file_count;

  40661. #define OpenCounter(X)  sqlite3_open_file_count+=(X)

  40662. #else

  40663. #define OpenCounter(X)

  40664. #endif /* defined(SQLITE_TEST) */

  40665. 

  40666. #endif /* !defined(_OS_COMMON_H_) */

  40667. 

  40668. /************** End of os_common.h *******************************************/

  40669. /************** Continuing where we left off in os_win.c *********************/

  40670. 

  40671. /*

  40672. ** Include the header file for the Windows VFS.

  40673. */

  40674. /* #include "os_win.h" */

  40675. 

  40676. /*

  40677. ** Compiling and using WAL mode requires several APIs that are only

  40678. ** available in Windows platforms based on the NT kernel.

  40679. */

  40680. #if !SQLITE_OS_WINNT && !defined(SQLITE_OMIT_WAL)

  40681. #  error "WAL mode requires support from the Windows NT kernel, compile\

  40682.  with SQLITE_OMIT_WAL."

  40683. #endif

  40684. 

  40685. #if !SQLITE_OS_WINNT && SQLITE_MAX_MMAP_SIZE>0

  40686. #  error "Memory mapped files require support from the Windows NT kernel,\

  40687.  compile with SQLITE_MAX_MMAP_SIZE=0."

  40688. #endif

  40689. 

  40690. /*

  40691. ** Are most of the Win32 ANSI APIs available (i.e. with certain exceptions

  40692. ** based on the sub-platform)?

  40693. */

  40694. #if !SQLITE_OS_WINCE && !SQLITE_OS_WINRT && !defined(SQLITE_WIN32_NO_ANSI)

  40695. #  define SQLITE_WIN32_HAS_ANSI

  40696. #endif

  40697. 

  40698. /*

  40699. ** Are most of the Win32 Unicode APIs available (i.e. with certain exceptions

  40700. ** based on the sub-platform)?

  40701. */

  40702. #if (SQLITE_OS_WINCE || SQLITE_OS_WINNT || SQLITE_OS_WINRT) && \

  40703.     !defined(SQLITE_WIN32_NO_WIDE)

  40704. #  define SQLITE_WIN32_HAS_WIDE

  40705. #endif

  40706. 

  40707. /*

  40708. ** Make sure at least one set of Win32 APIs is available.

  40709. */

  40710. #if !defined(SQLITE_WIN32_HAS_ANSI) && !defined(SQLITE_WIN32_HAS_WIDE)

  40711. #  error "At least one of SQLITE_WIN32_HAS_ANSI and SQLITE_WIN32_HAS_WIDE\

  40712.  must be defined."

  40713. #endif

  40714. 

  40715. /*

  40716. ** Define the required Windows SDK version constants if they are not

  40717. ** already available.

  40718. */

  40719. #ifndef NTDDI_WIN8

  40720. #  define NTDDI_WIN8                        0x06020000

  40721. #endif

  40722. 

  40723. #ifndef NTDDI_WINBLUE

  40724. #  define NTDDI_WINBLUE                     0x06030000

  40725. #endif

  40726. 

  40727. #ifndef NTDDI_WINTHRESHOLD

  40728. #  define NTDDI_WINTHRESHOLD                0x06040000

  40729. #endif

  40730. 

  40731. /*

  40732. ** Check to see if the GetVersionEx[AW] functions are deprecated on the

  40733. ** target system.  GetVersionEx was first deprecated in Win8.1.

  40734. */

  40735. #ifndef SQLITE_WIN32_GETVERSIONEX

  40736. #  if defined(NTDDI_VERSION) && NTDDI_VERSION >= NTDDI_WINBLUE

  40737. #    define SQLITE_WIN32_GETVERSIONEX   0   /* GetVersionEx() is deprecated */

  40738. #  else

  40739. #    define SQLITE_WIN32_GETVERSIONEX   1   /* GetVersionEx() is current */

  40740. #  endif

  40741. #endif

  40742. 

  40743. /*

  40744. ** Check to see if the CreateFileMappingA function is supported on the

  40745. ** target system.  It is unavailable when using "mincore.lib" on Win10.

  40746. ** When compiling for Windows 10, always assume "mincore.lib" is in use.

  40747. */

  40748. #ifndef SQLITE_WIN32_CREATEFILEMAPPINGA

  40749. #  if defined(NTDDI_VERSION) && NTDDI_VERSION >= NTDDI_WINTHRESHOLD

  40750. #    define SQLITE_WIN32_CREATEFILEMAPPINGA   0

  40751. #  else

  40752. #    define SQLITE_WIN32_CREATEFILEMAPPINGA   1

  40753. #  endif

  40754. #endif

  40755. 

  40756. /*

  40757. ** This constant should already be defined (in the "WinDef.h" SDK file).

  40758. */

  40759. #ifndef MAX_PATH

  40760. #  define MAX_PATH                      (260)

  40761. #endif

  40762. 

  40763. /*

  40764. ** Maximum pathname length (in chars) for Win32.  This should normally be

  40765. ** MAX_PATH.

  40766. */

  40767. #ifndef SQLITE_WIN32_MAX_PATH_CHARS

  40768. #  define SQLITE_WIN32_MAX_PATH_CHARS   (MAX_PATH)

  40769. #endif

  40770. 

  40771. /*

  40772. ** This constant should already be defined (in the "WinNT.h" SDK file).

  40773. */

  40774. #ifndef UNICODE_STRING_MAX_CHARS

  40775. #  define UNICODE_STRING_MAX_CHARS      (32767)

  40776. #endif

  40777. 

  40778. /*

  40779. ** Maximum pathname length (in chars) for WinNT.  This should normally be

  40780. ** UNICODE_STRING_MAX_CHARS.

  40781. */

  40782. #ifndef SQLITE_WINNT_MAX_PATH_CHARS

  40783. #  define SQLITE_WINNT_MAX_PATH_CHARS   (UNICODE_STRING_MAX_CHARS)

  40784. #endif

  40785. 

  40786. /*

  40787. ** Maximum pathname length (in bytes) for Win32.  The MAX_PATH macro is in

  40788. ** characters, so we allocate 4 bytes per character assuming worst-case of

  40789. ** 4-bytes-per-character for UTF8.

  40790. */

  40791. #ifndef SQLITE_WIN32_MAX_PATH_BYTES

  40792. #  define SQLITE_WIN32_MAX_PATH_BYTES   (SQLITE_WIN32_MAX_PATH_CHARS*4)

  40793. #endif

  40794. 

  40795. /*

  40796. ** Maximum pathname length (in bytes) for WinNT.  This should normally be

  40797. ** UNICODE_STRING_MAX_CHARS * sizeof(WCHAR).

  40798. */

  40799. #ifndef SQLITE_WINNT_MAX_PATH_BYTES

  40800. #  define SQLITE_WINNT_MAX_PATH_BYTES   \

  40801.                             (sizeof(WCHAR) * SQLITE_WINNT_MAX_PATH_CHARS)

  40802. #endif

  40803. 

  40804. /*

  40805. ** Maximum error message length (in chars) for WinRT.

  40806. */

  40807. #ifndef SQLITE_WIN32_MAX_ERRMSG_CHARS

  40808. #  define SQLITE_WIN32_MAX_ERRMSG_CHARS (1024)

  40809. #endif

  40810. 

  40811. /*

  40812. ** Returns non-zero if the character should be treated as a directory

  40813. ** separator.

  40814. */

  40815. #ifndef winIsDirSep

  40816. #  define winIsDirSep(a)                (((a) == '/') || ((a) == '\\'))

  40817. #endif

  40818. 

  40819. /*

  40820. ** This macro is used when a local variable is set to a value that is

  40821. ** [sometimes] not used by the code (e.g. via conditional compilation).

  40822. */

  40823. #ifndef UNUSED_VARIABLE_VALUE

  40824. #  define UNUSED_VARIABLE_VALUE(x)      (void)(x)

  40825. #endif

  40826. 

  40827. /*

  40828. ** Returns the character that should be used as the directory separator.

  40829. */

  40830. #ifndef winGetDirSep

  40831. #  define winGetDirSep()                '\\'

  40832. #endif

  40833. 

  40834. /*

  40835. ** Do we need to manually define the Win32 file mapping APIs for use with WAL

  40836. ** mode or memory mapped files (e.g. these APIs are available in the Windows

  40837. ** CE SDK; however, they are not present in the header file)?

  40838. */

  40839. #if SQLITE_WIN32_FILEMAPPING_API && \

  40840.         (!defined(SQLITE_OMIT_WAL) || SQLITE_MAX_MMAP_SIZE>0)

  40841. /*

  40842. ** Two of the file mapping APIs are different under WinRT.  Figure out which

  40843. ** set we need.

  40844. */

  40845. #if SQLITE_OS_WINRT

  40846. WINBASEAPI HANDLE WINAPI CreateFileMappingFromApp(HANDLE, \

  40847.         LPSECURITY_ATTRIBUTES, ULONG, ULONG64, LPCWSTR);

  40848. 

  40849. WINBASEAPI LPVOID WINAPI MapViewOfFileFromApp(HANDLE, ULONG, ULONG64, SIZE_T);

  40850. #else

  40851. #if defined(SQLITE_WIN32_HAS_ANSI)

  40852. WINBASEAPI HANDLE WINAPI CreateFileMappingA(HANDLE, LPSECURITY_ATTRIBUTES, \

  40853.         DWORD, DWORD, DWORD, LPCSTR);

  40854. #endif /* defined(SQLITE_WIN32_HAS_ANSI) */

  40855. 

  40856. #if defined(SQLITE_WIN32_HAS_WIDE)

  40857. WINBASEAPI HANDLE WINAPI CreateFileMappingW(HANDLE, LPSECURITY_ATTRIBUTES, \

  40858.         DWORD, DWORD, DWORD, LPCWSTR);

  40859. #endif /* defined(SQLITE_WIN32_HAS_WIDE) */

  40860. 

  40861. WINBASEAPI LPVOID WINAPI MapViewOfFile(HANDLE, DWORD, DWORD, DWORD, SIZE_T);

  40862. #endif /* SQLITE_OS_WINRT */

  40863. 

  40864. /*

  40865. ** These file mapping APIs are common to both Win32 and WinRT.

  40866. */

  40867. 

  40868. WINBASEAPI BOOL WINAPI FlushViewOfFile(LPCVOID, SIZE_T);

  40869. WINBASEAPI BOOL WINAPI UnmapViewOfFile(LPCVOID);

  40870. #endif /* SQLITE_WIN32_FILEMAPPING_API */

  40871. 

  40872. /*

  40873. ** Some Microsoft compilers lack this definition.

  40874. */

  40875. #ifndef INVALID_FILE_ATTRIBUTES

  40876. # define INVALID_FILE_ATTRIBUTES ((DWORD)-1)

  40877. #endif

  40878. 

  40879. #ifndef FILE_FLAG_MASK

  40880. # define FILE_FLAG_MASK          (0xFF3C0000)

  40881. #endif

  40882. 

  40883. #ifndef FILE_ATTRIBUTE_MASK

  40884. # define FILE_ATTRIBUTE_MASK     (0x0003FFF7)

  40885. #endif

  40886. 

  40887. #ifndef SQLITE_OMIT_WAL

  40888. /* Forward references to structures used for WAL */

  40889. typedef struct winShm winShm;           /* A connection to shared-memory */

  40890. typedef struct winShmNode winShmNode;   /* A region of shared-memory */

  40891. #endif

  40892. 

  40893. /*

  40894. ** WinCE lacks native support for file locking so we have to fake it

  40895. ** with some code of our own.

  40896. */

  40897. #if SQLITE_OS_WINCE

  40898. typedef struct winceLock {

  40899.   int nReaders;       /* Number of reader locks obtained */

  40900.   BOOL bPending;      /* Indicates a pending lock has been obtained */

  40901.   BOOL bReserved;     /* Indicates a reserved lock has been obtained */

  40902.   BOOL bExclusive;    /* Indicates an exclusive lock has been obtained */

  40903. } winceLock;

  40904. #endif

  40905. 

  40906. /*

  40907. ** The winFile structure is a subclass of sqlite3_file* specific to the win32

  40908. ** portability layer.

  40909. */

  40910. typedef struct winFile winFile;

  40911. struct winFile {

  40912.   const sqlite3_io_methods *pMethod; /*** Must be first ***/

  40913.   sqlite3_vfs *pVfs;      /* The VFS used to open this file */

  40914.   HANDLE h;               /* Handle for accessing the file */

  40915.   u8 locktype;            /* Type of lock currently held on this file */

  40916.   short sharedLockByte;   /* Randomly chosen byte used as a shared lock */

  40917.   u8 ctrlFlags;           /* Flags.  See WINFILE_* below */

  40918.   DWORD lastErrno;        /* The Windows errno from the last I/O error */

  40919. #ifndef SQLITE_OMIT_WAL

  40920.   winShm *pShm;           /* Instance of shared memory on this file */

  40921. #endif

  40922.   const char *zPath;      /* Full pathname of this file */

  40923.   int szChunk;            /* Chunk size configured by FCNTL_CHUNK_SIZE */

  40924. #if SQLITE_OS_WINCE

  40925.   LPWSTR zDeleteOnClose;  /* Name of file to delete when closing */

  40926.   HANDLE hMutex;          /* Mutex used to control access to shared lock */

  40927.   HANDLE hShared;         /* Shared memory segment used for locking */

  40928.   winceLock local;        /* Locks obtained by this instance of winFile */

  40929.   winceLock *shared;      /* Global shared lock memory for the file  */

  40930. #endif

  40931. #if SQLITE_MAX_MMAP_SIZE>0

  40932.   int nFetchOut;                /* Number of outstanding xFetch references */

  40933.   HANDLE hMap;                  /* Handle for accessing memory mapping */

  40934.   void *pMapRegion;             /* Area memory mapped */

  40935.   sqlite3_int64 mmapSize;       /* Size of mapped region */

  40936.   sqlite3_int64 mmapSizeMax;    /* Configured FCNTL_MMAP_SIZE value */

  40937. #endif

  40938. };

  40939. 

  40940. /*

  40941. ** The winVfsAppData structure is used for the pAppData member for all of the

  40942. ** Win32 VFS variants.

  40943. */

  40944. typedef struct winVfsAppData winVfsAppData;

  40945. struct winVfsAppData {

  40946.   const sqlite3_io_methods *pMethod; /* The file I/O methods to use. */

  40947.   void *pAppData;                    /* The extra pAppData, if any. */

  40948.   BOOL bNoLock;                      /* Non-zero if locking is disabled. */

  40949. };

  40950. 

  40951. /*

  40952. ** Allowed values for winFile.ctrlFlags

  40953. */

  40954. #define WINFILE_RDONLY          0x02   /* Connection is read only */

  40955. #define WINFILE_PERSIST_WAL     0x04   /* Persistent WAL mode */

  40956. #define WINFILE_PSOW            0x10   /* SQLITE_IOCAP_POWERSAFE_OVERWRITE */

  40957. 

  40958. /*

  40959.  * The size of the buffer used by sqlite3_win32_write_debug().

  40960.  */

  40961. #ifndef SQLITE_WIN32_DBG_BUF_SIZE

  40962. #  define SQLITE_WIN32_DBG_BUF_SIZE   ((int)(4096-sizeof(DWORD)))

  40963. #endif

  40964. 

  40965. /*

  40966.  * If compiled with SQLITE_WIN32_MALLOC on Windows, we will use the

  40967.  * various Win32 API heap functions instead of our own.

  40968.  */

  40969. #ifdef SQLITE_WIN32_MALLOC

  40970. 

  40971. /*

  40972.  * If this is non-zero, an isolated heap will be created by the native Win32

  40973.  * allocator subsystem; otherwise, the default process heap will be used.  This

  40974.  * setting has no effect when compiling for WinRT.  By default, this is enabled

  40975.  * and an isolated heap will be created to store all allocated data.

  40976.  *

  40977.  ******************************************************************************

  40978.  * WARNING: It is important to note that when this setting is non-zero and the

  40979.  *          winMemShutdown function is called (e.g. by the sqlite3_shutdown

  40980.  *          function), all data that was allocated using the isolated heap will

  40981.  *          be freed immediately and any attempt to access any of that freed

  40982.  *          data will almost certainly result in an immediate access violation.

  40983.  ******************************************************************************

  40984.  */

  40985. #ifndef SQLITE_WIN32_HEAP_CREATE

  40986. #  define SQLITE_WIN32_HEAP_CREATE        (TRUE)

  40987. #endif

  40988. 

  40989. /*

  40990.  * This is the maximum possible initial size of the Win32-specific heap, in

  40991.  * bytes.

  40992.  */

  40993. #ifndef SQLITE_WIN32_HEAP_MAX_INIT_SIZE

  40994. #  define SQLITE_WIN32_HEAP_MAX_INIT_SIZE (4294967295U)

  40995. #endif

  40996. 

  40997. /*

  40998.  * This is the extra space for the initial size of the Win32-specific heap,

  40999.  * in bytes.  This value may be zero.

  41000.  */

  41001. #ifndef SQLITE_WIN32_HEAP_INIT_EXTRA

  41002. #  define SQLITE_WIN32_HEAP_INIT_EXTRA  (4194304)

  41003. #endif

  41004. 

  41005. /*

  41006.  * Calculate the maximum legal cache size, in pages, based on the maximum

  41007.  * possible initial heap size and the default page size, setting aside the

  41008.  * needed extra space.

  41009.  */

  41010. #ifndef SQLITE_WIN32_MAX_CACHE_SIZE

  41011. #  define SQLITE_WIN32_MAX_CACHE_SIZE   (((SQLITE_WIN32_HEAP_MAX_INIT_SIZE) - \

  41012.                                           (SQLITE_WIN32_HEAP_INIT_EXTRA)) / \

  41013.                                          (SQLITE_DEFAULT_PAGE_SIZE))

  41014. #endif

  41015. 

  41016. /*

  41017.  * This is cache size used in the calculation of the initial size of the

  41018.  * Win32-specific heap.  It cannot be negative.

  41019.  */

  41020. #ifndef SQLITE_WIN32_CACHE_SIZE

  41021. #  if SQLITE_DEFAULT_CACHE_SIZE>=0

  41022. #    define SQLITE_WIN32_CACHE_SIZE     (SQLITE_DEFAULT_CACHE_SIZE)

  41023. #  else

  41024. #    define SQLITE_WIN32_CACHE_SIZE     (-(SQLITE_DEFAULT_CACHE_SIZE))

  41025. #  endif

  41026. #endif

  41027. 

  41028. /*

  41029.  * Make sure that the calculated cache size, in pages, cannot cause the

  41030.  * initial size of the Win32-specific heap to exceed the maximum amount

  41031.  * of memory that can be specified in the call to HeapCreate.

  41032.  */

  41033. #if SQLITE_WIN32_CACHE_SIZE>SQLITE_WIN32_MAX_CACHE_SIZE

  41034. #  undef SQLITE_WIN32_CACHE_SIZE

  41035. #  define SQLITE_WIN32_CACHE_SIZE       (2000)

  41036. #endif

  41037. 

  41038. /*

  41039.  * The initial size of the Win32-specific heap.  This value may be zero.

  41040.  */

  41041. #ifndef SQLITE_WIN32_HEAP_INIT_SIZE

  41042. #  define SQLITE_WIN32_HEAP_INIT_SIZE   ((SQLITE_WIN32_CACHE_SIZE) * \

  41043.                                          (SQLITE_DEFAULT_PAGE_SIZE) + \

  41044.                                          (SQLITE_WIN32_HEAP_INIT_EXTRA))

  41045. #endif

  41046. 

  41047. /*

  41048.  * The maximum size of the Win32-specific heap.  This value may be zero.

  41049.  */

  41050. #ifndef SQLITE_WIN32_HEAP_MAX_SIZE

  41051. #  define SQLITE_WIN32_HEAP_MAX_SIZE    (0)

  41052. #endif

  41053. 

  41054. /*

  41055.  * The extra flags to use in calls to the Win32 heap APIs.  This value may be

  41056.  * zero for the default behavior.

  41057.  */

  41058. #ifndef SQLITE_WIN32_HEAP_FLAGS

  41059. #  define SQLITE_WIN32_HEAP_FLAGS       (0)

  41060. #endif

  41061. 

  41062. 

  41063. /*

  41064. ** The winMemData structure stores information required by the Win32-specific

  41065. ** sqlite3_mem_methods implementation.

  41066. */

  41067. typedef struct winMemData winMemData;

  41068. struct winMemData {

  41069. #ifndef NDEBUG

  41070.   u32 magic1;   /* Magic number to detect structure corruption. */

  41071. #endif

  41072.   HANDLE hHeap; /* The handle to our heap. */

  41073.   BOOL bOwned;  /* Do we own the heap (i.e. destroy it on shutdown)? */

  41074. #ifndef NDEBUG

  41075.   u32 magic2;   /* Magic number to detect structure corruption. */

  41076. #endif

  41077. };

  41078. 

  41079. #ifndef NDEBUG

  41080. #define WINMEM_MAGIC1     0x42b2830b

  41081. #define WINMEM_MAGIC2     0xbd4d7cf4

  41082. #endif

  41083. 

  41084. static struct winMemData win_mem_data = {

  41085. #ifndef NDEBUG

  41086.   WINMEM_MAGIC1,

  41087. #endif

  41088.   NULL, FALSE

  41089. #ifndef NDEBUG

  41090.   ,WINMEM_MAGIC2

  41091. #endif

  41092. };

  41093. 

  41094. #ifndef NDEBUG

  41095. #define winMemAssertMagic1() assert( win_mem_data.magic1==WINMEM_MAGIC1 )

  41096. #define winMemAssertMagic2() assert( win_mem_data.magic2==WINMEM_MAGIC2 )

  41097. #define winMemAssertMagic()  winMemAssertMagic1(); winMemAssertMagic2();

  41098. #else

  41099. #define winMemAssertMagic()

  41100. #endif

  41101. 

  41102. #define winMemGetDataPtr()  &win_mem_data

  41103. #define winMemGetHeap()     win_mem_data.hHeap

  41104. #define winMemGetOwned()    win_mem_data.bOwned

  41105. 

  41106. static void *winMemMalloc(int nBytes);

  41107. static void winMemFree(void *pPrior);

  41108. static void *winMemRealloc(void *pPrior, int nBytes);

  41109. static int winMemSize(void *p);

  41110. static int winMemRoundup(int n);

  41111. static int winMemInit(void *pAppData);

  41112. static void winMemShutdown(void *pAppData);

  41113. 

  41114. SQLITE_PRIVATE const sqlite3_mem_methods *sqlite3MemGetWin32(void);

  41115. #endif /* SQLITE_WIN32_MALLOC */

  41116. 

  41117. /*

  41118. ** The following variable is (normally) set once and never changes

  41119. ** thereafter.  It records whether the operating system is Win9x

  41120. ** or WinNT.

  41121. **

  41122. ** 0:   Operating system unknown.

  41123. ** 1:   Operating system is Win9x.

  41124. ** 2:   Operating system is WinNT.

  41125. **

  41126. ** In order to facilitate testing on a WinNT system, the test fixture

  41127. ** can manually set this value to 1 to emulate Win98 behavior.

  41128. */

  41129. #ifdef SQLITE_TEST

  41130. SQLITE_API LONG SQLITE_WIN32_VOLATILE sqlite3_os_type = 0;

  41131. #else

  41132. static LONG SQLITE_WIN32_VOLATILE sqlite3_os_type = 0;

  41133. #endif

  41134. 

  41135. #ifndef SYSCALL

  41136. #  define SYSCALL sqlite3_syscall_ptr

  41137. #endif

  41138. 

  41139. /*

  41140. ** This function is not available on Windows CE or WinRT.

  41141.  */

  41142. 

  41143. #if SQLITE_OS_WINCE || SQLITE_OS_WINRT

  41144. #  define osAreFileApisANSI()       1

  41145. #endif

  41146. 

  41147. /*

  41148. ** Many system calls are accessed through pointer-to-functions so that

  41149. ** they may be overridden at runtime to facilitate fault injection during

  41150. ** testing and sandboxing.  The following array holds the names and pointers

  41151. ** to all overrideable system calls.

  41152. */

  41153. static struct win_syscall {

  41154.   const char *zName;            /* Name of the system call */

  41155.   sqlite3_syscall_ptr pCurrent; /* Current value of the system call */

  41156.   sqlite3_syscall_ptr pDefault; /* Default value */

  41157. } aSyscall[] = {

  41158. #if !SQLITE_OS_WINCE && !SQLITE_OS_WINRT

  41159.   { "AreFileApisANSI",         (SYSCALL)AreFileApisANSI,         0 },

  41160. #else

  41161.   { "AreFileApisANSI",         (SYSCALL)0,                       0 },

  41162. #endif

  41163. 

  41164. #ifndef osAreFileApisANSI

  41165. #define osAreFileApisANSI ((BOOL(WINAPI*)(VOID))aSyscall[0].pCurrent)

  41166. #endif

  41167. 

  41168. #if SQLITE_OS_WINCE && defined(SQLITE_WIN32_HAS_WIDE)

  41169.   { "CharLowerW",              (SYSCALL)CharLowerW,              0 },

  41170. #else

  41171.   { "CharLowerW",              (SYSCALL)0,                       0 },

  41172. #endif

  41173. 

  41174. #define osCharLowerW ((LPWSTR(WINAPI*)(LPWSTR))aSyscall[1].pCurrent)

  41175. 

  41176. #if SQLITE_OS_WINCE && defined(SQLITE_WIN32_HAS_WIDE)

  41177.   { "CharUpperW",              (SYSCALL)CharUpperW,              0 },

  41178. #else

  41179.   { "CharUpperW",              (SYSCALL)0,                       0 },

  41180. #endif

  41181. 

  41182. #define osCharUpperW ((LPWSTR(WINAPI*)(LPWSTR))aSyscall[2].pCurrent)

  41183. 

  41184.   { "CloseHandle",             (SYSCALL)CloseHandle,             0 },

  41185. 

  41186. #define osCloseHandle ((BOOL(WINAPI*)(HANDLE))aSyscall[3].pCurrent)

  41187. 

  41188. #if defined(SQLITE_WIN32_HAS_ANSI)

  41189.   { "CreateFileA",             (SYSCALL)CreateFileA,             0 },

  41190. #else

  41191.   { "CreateFileA",             (SYSCALL)0,                       0 },

  41192. #endif

  41193. 

  41194. #define osCreateFileA ((HANDLE(WINAPI*)(LPCSTR,DWORD,DWORD, \

  41195.         LPSECURITY_ATTRIBUTES,DWORD,DWORD,HANDLE))aSyscall[4].pCurrent)

  41196. 

  41197. #if !SQLITE_OS_WINRT && defined(SQLITE_WIN32_HAS_WIDE)

  41198.   { "CreateFileW",             (SYSCALL)CreateFileW,             0 },

  41199. #else

  41200.   { "CreateFileW",             (SYSCALL)0,                       0 },

  41201. #endif

  41202. 

  41203. #define osCreateFileW ((HANDLE(WINAPI*)(LPCWSTR,DWORD,DWORD, \

  41204.         LPSECURITY_ATTRIBUTES,DWORD,DWORD,HANDLE))aSyscall[5].pCurrent)

  41205. 

  41206. #if !SQLITE_OS_WINRT && defined(SQLITE_WIN32_HAS_ANSI) && \

  41207.         (!defined(SQLITE_OMIT_WAL) || SQLITE_MAX_MMAP_SIZE>0) && \

  41208.         SQLITE_WIN32_CREATEFILEMAPPINGA

  41209.   { "CreateFileMappingA",      (SYSCALL)CreateFileMappingA,      0 },

  41210. #else

  41211.   { "CreateFileMappingA",      (SYSCALL)0,                       0 },

  41212. #endif

  41213. 

  41214. #define osCreateFileMappingA ((HANDLE(WINAPI*)(HANDLE,LPSECURITY_ATTRIBUTES, \

  41215.         DWORD,DWORD,DWORD,LPCSTR))aSyscall[6].pCurrent)

  41216. 

  41217. #if SQLITE_OS_WINCE || (!SQLITE_OS_WINRT && defined(SQLITE_WIN32_HAS_WIDE) && \

  41218.         (!defined(SQLITE_OMIT_WAL) || SQLITE_MAX_MMAP_SIZE>0))

  41219.   { "CreateFileMappingW",      (SYSCALL)CreateFileMappingW,      0 },

  41220. #else

  41221.   { "CreateFileMappingW",      (SYSCALL)0,                       0 },

  41222. #endif

  41223. 

  41224. #define osCreateFileMappingW ((HANDLE(WINAPI*)(HANDLE,LPSECURITY_ATTRIBUTES, \

  41225.         DWORD,DWORD,DWORD,LPCWSTR))aSyscall[7].pCurrent)

  41226. 

  41227. #if !SQLITE_OS_WINRT && defined(SQLITE_WIN32_HAS_WIDE)

  41228.   { "CreateMutexW",            (SYSCALL)CreateMutexW,            0 },

  41229. #else

  41230.   { "CreateMutexW",            (SYSCALL)0,                       0 },

  41231. #endif

  41232. 

  41233. #define osCreateMutexW ((HANDLE(WINAPI*)(LPSECURITY_ATTRIBUTES,BOOL, \

  41234.         LPCWSTR))aSyscall[8].pCurrent)

  41235. 

  41236. #if defined(SQLITE_WIN32_HAS_ANSI)

  41237.   { "DeleteFileA",             (SYSCALL)DeleteFileA,             0 },

  41238. #else

  41239.   { "DeleteFileA",             (SYSCALL)0,                       0 },

  41240. #endif

  41241. 

  41242. #define osDeleteFileA ((BOOL(WINAPI*)(LPCSTR))aSyscall[9].pCurrent)

  41243. 

  41244. #if defined(SQLITE_WIN32_HAS_WIDE)

  41245.   { "DeleteFileW",             (SYSCALL)DeleteFileW,             0 },

  41246. #else

  41247.   { "DeleteFileW",             (SYSCALL)0,                       0 },

  41248. #endif

  41249. 

  41250. #define osDeleteFileW ((BOOL(WINAPI*)(LPCWSTR))aSyscall[10].pCurrent)

  41251. 

  41252. #if SQLITE_OS_WINCE

  41253.   { "FileTimeToLocalFileTime", (SYSCALL)FileTimeToLocalFileTime, 0 },

  41254. #else

  41255.   { "FileTimeToLocalFileTime", (SYSCALL)0,                       0 },

  41256. #endif

  41257. 

  41258. #define osFileTimeToLocalFileTime ((BOOL(WINAPI*)(CONST FILETIME*, \

  41259.         LPFILETIME))aSyscall[11].pCurrent)

  41260. 

  41261. #if SQLITE_OS_WINCE

  41262.   { "FileTimeToSystemTime",    (SYSCALL)FileTimeToSystemTime,    0 },

  41263. #else

  41264.   { "FileTimeToSystemTime",    (SYSCALL)0,                       0 },

  41265. #endif

  41266. 

  41267. #define osFileTimeToSystemTime ((BOOL(WINAPI*)(CONST FILETIME*, \

  41268.         LPSYSTEMTIME))aSyscall[12].pCurrent)

  41269. 

  41270.   { "FlushFileBuffers",        (SYSCALL)FlushFileBuffers,        0 },

  41271. 

  41272. #define osFlushFileBuffers ((BOOL(WINAPI*)(HANDLE))aSyscall[13].pCurrent)

  41273. 

  41274. #if defined(SQLITE_WIN32_HAS_ANSI)

  41275.   { "FormatMessageA",          (SYSCALL)FormatMessageA,          0 },

  41276. #else

  41277.   { "FormatMessageA",          (SYSCALL)0,                       0 },

  41278. #endif

  41279. 

  41280. #define osFormatMessageA ((DWORD(WINAPI*)(DWORD,LPCVOID,DWORD,DWORD,LPSTR, \

  41281.         DWORD,va_list*))aSyscall[14].pCurrent)

  41282. 

  41283. #if defined(SQLITE_WIN32_HAS_WIDE)

  41284.   { "FormatMessageW",          (SYSCALL)FormatMessageW,          0 },

  41285. #else

  41286.   { "FormatMessageW",          (SYSCALL)0,                       0 },

  41287. #endif

  41288. 

  41289. #define osFormatMessageW ((DWORD(WINAPI*)(DWORD,LPCVOID,DWORD,DWORD,LPWSTR, \

  41290.         DWORD,va_list*))aSyscall[15].pCurrent)

  41291. 

  41292. #if !defined(SQLITE_OMIT_LOAD_EXTENSION)

  41293.   { "FreeLibrary",             (SYSCALL)FreeLibrary,             0 },

  41294. #else

  41295.   { "FreeLibrary",             (SYSCALL)0,                       0 },

  41296. #endif

  41297. 

  41298. #define osFreeLibrary ((BOOL(WINAPI*)(HMODULE))aSyscall[16].pCurrent)

  41299. 

  41300.   { "GetCurrentProcessId",     (SYSCALL)GetCurrentProcessId,     0 },

  41301. 

  41302. #define osGetCurrentProcessId ((DWORD(WINAPI*)(VOID))aSyscall[17].pCurrent)

  41303. 

  41304. #if !SQLITE_OS_WINCE && defined(SQLITE_WIN32_HAS_ANSI)

  41305.   { "GetDiskFreeSpaceA",       (SYSCALL)GetDiskFreeSpaceA,       0 },

  41306. #else

  41307.   { "GetDiskFreeSpaceA",       (SYSCALL)0,                       0 },

  41308. #endif

  41309. 

  41310. #define osGetDiskFreeSpaceA ((BOOL(WINAPI*)(LPCSTR,LPDWORD,LPDWORD,LPDWORD, \

  41311.         LPDWORD))aSyscall[18].pCurrent)

  41312. 

  41313. #if !SQLITE_OS_WINCE && !SQLITE_OS_WINRT && defined(SQLITE_WIN32_HAS_WIDE)

  41314.   { "GetDiskFreeSpaceW",       (SYSCALL)GetDiskFreeSpaceW,       0 },

  41315. #else

  41316.   { "GetDiskFreeSpaceW",       (SYSCALL)0,                       0 },

  41317. #endif

  41318. 

  41319. #define osGetDiskFreeSpaceW ((BOOL(WINAPI*)(LPCWSTR,LPDWORD,LPDWORD,LPDWORD, \

  41320.         LPDWORD))aSyscall[19].pCurrent)

  41321. 

  41322. #if defined(SQLITE_WIN32_HAS_ANSI)

  41323.   { "GetFileAttributesA",      (SYSCALL)GetFileAttributesA,      0 },

  41324. #else

  41325.   { "GetFileAttributesA",      (SYSCALL)0,                       0 },

  41326. #endif

  41327. 

  41328. #define osGetFileAttributesA ((DWORD(WINAPI*)(LPCSTR))aSyscall[20].pCurrent)

  41329. 

  41330. #if !SQLITE_OS_WINRT && defined(SQLITE_WIN32_HAS_WIDE)

  41331.   { "GetFileAttributesW",      (SYSCALL)GetFileAttributesW,      0 },

  41332. #else

  41333.   { "GetFileAttributesW",      (SYSCALL)0,                       0 },

  41334. #endif

  41335. 

  41336. #define osGetFileAttributesW ((DWORD(WINAPI*)(LPCWSTR))aSyscall[21].pCurrent)

  41337. 

  41338. #if defined(SQLITE_WIN32_HAS_WIDE)

  41339.   { "GetFileAttributesExW",    (SYSCALL)GetFileAttributesExW,    0 },

  41340. #else

  41341.   { "GetFileAttributesExW",    (SYSCALL)0,                       0 },

  41342. #endif

  41343. 

  41344. #define osGetFileAttributesExW ((BOOL(WINAPI*)(LPCWSTR,GET_FILEEX_INFO_LEVELS, \

  41345.         LPVOID))aSyscall[22].pCurrent)

  41346. 

  41347. #if !SQLITE_OS_WINRT

  41348.   { "GetFileSize",             (SYSCALL)GetFileSize,             0 },

  41349. #else

  41350.   { "GetFileSize",             (SYSCALL)0,                       0 },

  41351. #endif

  41352. 

  41353. #define osGetFileSize ((DWORD(WINAPI*)(HANDLE,LPDWORD))aSyscall[23].pCurrent)

  41354. 

  41355. #if !SQLITE_OS_WINCE && defined(SQLITE_WIN32_HAS_ANSI)

  41356.   { "GetFullPathNameA",        (SYSCALL)GetFullPathNameA,        0 },

  41357. #else

  41358.   { "GetFullPathNameA",        (SYSCALL)0,                       0 },

  41359. #endif

  41360. 

  41361. #define osGetFullPathNameA ((DWORD(WINAPI*)(LPCSTR,DWORD,LPSTR, \

  41362.         LPSTR*))aSyscall[24].pCurrent)

  41363. 

  41364. #if !SQLITE_OS_WINCE && !SQLITE_OS_WINRT && defined(SQLITE_WIN32_HAS_WIDE)

  41365.   { "GetFullPathNameW",        (SYSCALL)GetFullPathNameW,        0 },

  41366. #else

  41367.   { "GetFullPathNameW",        (SYSCALL)0,                       0 },

  41368. #endif

  41369. 

  41370. #define osGetFullPathNameW ((DWORD(WINAPI*)(LPCWSTR,DWORD,LPWSTR, \

  41371.         LPWSTR*))aSyscall[25].pCurrent)

  41372. 

  41373.   { "GetLastError",            (SYSCALL)GetLastError,            0 },

  41374. 

  41375. #define osGetLastError ((DWORD(WINAPI*)(VOID))aSyscall[26].pCurrent)

  41376. 

  41377. #if !defined(SQLITE_OMIT_LOAD_EXTENSION)

  41378. #if SQLITE_OS_WINCE

  41379.   /* The GetProcAddressA() routine is only available on Windows CE. */

  41380.   { "GetProcAddressA",         (SYSCALL)GetProcAddressA,         0 },

  41381. #else

  41382.   /* All other Windows platforms expect GetProcAddress() to take

  41383.   ** an ANSI string regardless of the _UNICODE setting */

  41384.   { "GetProcAddressA",         (SYSCALL)GetProcAddress,          0 },

  41385. #endif

  41386. #else

  41387.   { "GetProcAddressA",         (SYSCALL)0,                       0 },

  41388. #endif

  41389. 

  41390. #define osGetProcAddressA ((FARPROC(WINAPI*)(HMODULE, \

  41391.         LPCSTR))aSyscall[27].pCurrent)

  41392. 

  41393. #if !SQLITE_OS_WINRT

  41394.   { "GetSystemInfo",           (SYSCALL)GetSystemInfo,           0 },

  41395. #else

  41396.   { "GetSystemInfo",           (SYSCALL)0,                       0 },

  41397. #endif

  41398. 

  41399. #define osGetSystemInfo ((VOID(WINAPI*)(LPSYSTEM_INFO))aSyscall[28].pCurrent)

  41400. 

  41401.   { "GetSystemTime",           (SYSCALL)GetSystemTime,           0 },

  41402. 

  41403. #define osGetSystemTime ((VOID(WINAPI*)(LPSYSTEMTIME))aSyscall[29].pCurrent)

  41404. 

  41405. #if !SQLITE_OS_WINCE

  41406.   { "GetSystemTimeAsFileTime", (SYSCALL)GetSystemTimeAsFileTime, 0 },

  41407. #else

  41408.   { "GetSystemTimeAsFileTime", (SYSCALL)0,                       0 },

  41409. #endif

  41410. 

  41411. #define osGetSystemTimeAsFileTime ((VOID(WINAPI*)( \

  41412.         LPFILETIME))aSyscall[30].pCurrent)

  41413. 

  41414. #if defined(SQLITE_WIN32_HAS_ANSI)

  41415.   { "GetTempPathA",            (SYSCALL)GetTempPathA,            0 },

  41416. #else

  41417.   { "GetTempPathA",            (SYSCALL)0,                       0 },

  41418. #endif

  41419. 

  41420. #define osGetTempPathA ((DWORD(WINAPI*)(DWORD,LPSTR))aSyscall[31].pCurrent)

  41421. 

  41422. #if !SQLITE_OS_WINRT && defined(SQLITE_WIN32_HAS_WIDE)

  41423.   { "GetTempPathW",            (SYSCALL)GetTempPathW,            0 },

  41424. #else

  41425.   { "GetTempPathW",            (SYSCALL)0,                       0 },

  41426. #endif

  41427. 

  41428. #define osGetTempPathW ((DWORD(WINAPI*)(DWORD,LPWSTR))aSyscall[32].pCurrent)

  41429. 

  41430. #if !SQLITE_OS_WINRT

  41431.   { "GetTickCount",            (SYSCALL)GetTickCount,            0 },

  41432. #else

  41433.   { "GetTickCount",            (SYSCALL)0,                       0 },

  41434. #endif

  41435. 

  41436. #define osGetTickCount ((DWORD(WINAPI*)(VOID))aSyscall[33].pCurrent)

  41437. 

  41438. #if defined(SQLITE_WIN32_HAS_ANSI) && SQLITE_WIN32_GETVERSIONEX

  41439.   { "GetVersionExA",           (SYSCALL)GetVersionExA,           0 },

  41440. #else

  41441.   { "GetVersionExA",           (SYSCALL)0,                       0 },

  41442. #endif

  41443. 

  41444. #define osGetVersionExA ((BOOL(WINAPI*)( \

  41445.         LPOSVERSIONINFOA))aSyscall[34].pCurrent)

  41446. 

  41447. #if !SQLITE_OS_WINRT && defined(SQLITE_WIN32_HAS_WIDE) && \

  41448.         SQLITE_WIN32_GETVERSIONEX

  41449.   { "GetVersionExW",           (SYSCALL)GetVersionExW,           0 },

  41450. #else

  41451.   { "GetVersionExW",           (SYSCALL)0,                       0 },

  41452. #endif

  41453. 

  41454. #define osGetVersionExW ((BOOL(WINAPI*)( \

  41455.         LPOSVERSIONINFOW))aSyscall[35].pCurrent)

  41456. 

  41457.   { "HeapAlloc",               (SYSCALL)HeapAlloc,               0 },

  41458. 

  41459. #define osHeapAlloc ((LPVOID(WINAPI*)(HANDLE,DWORD, \

  41460.         SIZE_T))aSyscall[36].pCurrent)

  41461. 

  41462. #if !SQLITE_OS_WINRT

  41463.   { "HeapCreate",              (SYSCALL)HeapCreate,              0 },

  41464. #else

  41465.   { "HeapCreate",              (SYSCALL)0,                       0 },

  41466. #endif

  41467. 

  41468. #define osHeapCreate ((HANDLE(WINAPI*)(DWORD,SIZE_T, \

  41469.         SIZE_T))aSyscall[37].pCurrent)

  41470. 

  41471. #if !SQLITE_OS_WINRT

  41472.   { "HeapDestroy",             (SYSCALL)HeapDestroy,             0 },

  41473. #else

  41474.   { "HeapDestroy",             (SYSCALL)0,                       0 },

  41475. #endif

  41476. 

  41477. #define osHeapDestroy ((BOOL(WINAPI*)(HANDLE))aSyscall[38].pCurrent)

  41478. 

  41479.   { "HeapFree",                (SYSCALL)HeapFree,                0 },

  41480. 

  41481. #define osHeapFree ((BOOL(WINAPI*)(HANDLE,DWORD,LPVOID))aSyscall[39].pCurrent)

  41482. 

  41483.   { "HeapReAlloc",             (SYSCALL)HeapReAlloc,             0 },

  41484. 

  41485. #define osHeapReAlloc ((LPVOID(WINAPI*)(HANDLE,DWORD,LPVOID, \

  41486.         SIZE_T))aSyscall[40].pCurrent)

  41487. 

  41488.   { "HeapSize",                (SYSCALL)HeapSize,                0 },

  41489. 

  41490. #define osHeapSize ((SIZE_T(WINAPI*)(HANDLE,DWORD, \

  41491.         LPCVOID))aSyscall[41].pCurrent)

  41492. 

  41493. #if !SQLITE_OS_WINRT

  41494.   { "HeapValidate",            (SYSCALL)HeapValidate,            0 },

  41495. #else

  41496.   { "HeapValidate",            (SYSCALL)0,                       0 },

  41497. #endif

  41498. 

  41499. #define osHeapValidate ((BOOL(WINAPI*)(HANDLE,DWORD, \

  41500.         LPCVOID))aSyscall[42].pCurrent)

  41501. 

  41502. #if !SQLITE_OS_WINCE && !SQLITE_OS_WINRT

  41503.   { "HeapCompact",             (SYSCALL)HeapCompact,             0 },

  41504. #else

  41505.   { "HeapCompact",             (SYSCALL)0,                       0 },

  41506. #endif

  41507. 

  41508. #define osHeapCompact ((UINT(WINAPI*)(HANDLE,DWORD))aSyscall[43].pCurrent)

  41509. 

  41510. #if defined(SQLITE_WIN32_HAS_ANSI) && !defined(SQLITE_OMIT_LOAD_EXTENSION)

  41511.   { "LoadLibraryA",            (SYSCALL)LoadLibraryA,            0 },

  41512. #else

  41513.   { "LoadLibraryA",            (SYSCALL)0,                       0 },

  41514. #endif

  41515. 

  41516. #define osLoadLibraryA ((HMODULE(WINAPI*)(LPCSTR))aSyscall[44].pCurrent)

  41517. 

  41518. #if !SQLITE_OS_WINRT && defined(SQLITE_WIN32_HAS_WIDE) && \

  41519.         !defined(SQLITE_OMIT_LOAD_EXTENSION)

  41520.   { "LoadLibraryW",            (SYSCALL)LoadLibraryW,            0 },

  41521. #else

  41522.   { "LoadLibraryW",            (SYSCALL)0,                       0 },

  41523. #endif

  41524. 

  41525. #define osLoadLibraryW ((HMODULE(WINAPI*)(LPCWSTR))aSyscall[45].pCurrent)

  41526. 

  41527. #if !SQLITE_OS_WINRT

  41528.   { "LocalFree",               (SYSCALL)LocalFree,               0 },

  41529. #else

  41530.   { "LocalFree",               (SYSCALL)0,                       0 },

  41531. #endif

  41532. 

  41533. #define osLocalFree ((HLOCAL(WINAPI*)(HLOCAL))aSyscall[46].pCurrent)

  41534. 

  41535. #if !SQLITE_OS_WINCE && !SQLITE_OS_WINRT

  41536.   { "LockFile",                (SYSCALL)LockFile,                0 },

  41537. #else

  41538.   { "LockFile",                (SYSCALL)0,                       0 },

  41539. #endif

  41540. 

  41541. #ifndef osLockFile

  41542. #define osLockFile ((BOOL(WINAPI*)(HANDLE,DWORD,DWORD,DWORD, \

  41543.         DWORD))aSyscall[47].pCurrent)

  41544. #endif

  41545. 

  41546. #if !SQLITE_OS_WINCE

  41547.   { "LockFileEx",              (SYSCALL)LockFileEx,              0 },

  41548. #else

  41549.   { "LockFileEx",              (SYSCALL)0,                       0 },

  41550. #endif

  41551. 

  41552. #ifndef osLockFileEx

  41553. #define osLockFileEx ((BOOL(WINAPI*)(HANDLE,DWORD,DWORD,DWORD,DWORD, \

  41554.         LPOVERLAPPED))aSyscall[48].pCurrent)

  41555. #endif

  41556. 

  41557. #if SQLITE_OS_WINCE || (!SQLITE_OS_WINRT && \

  41558.         (!defined(SQLITE_OMIT_WAL) || SQLITE_MAX_MMAP_SIZE>0))

  41559.   { "MapViewOfFile",           (SYSCALL)MapViewOfFile,           0 },

  41560. #else

  41561.   { "MapViewOfFile",           (SYSCALL)0,                       0 },

  41562. #endif

  41563. 

  41564. #define osMapViewOfFile ((LPVOID(WINAPI*)(HANDLE,DWORD,DWORD,DWORD, \

  41565.         SIZE_T))aSyscall[49].pCurrent)

  41566. 

  41567.   { "MultiByteToWideChar",     (SYSCALL)MultiByteToWideChar,     0 },

  41568. 

  41569. #define osMultiByteToWideChar ((int(WINAPI*)(UINT,DWORD,LPCSTR,int,LPWSTR, \

  41570.         int))aSyscall[50].pCurrent)

  41571. 

  41572.   { "QueryPerformanceCounter", (SYSCALL)QueryPerformanceCounter, 0 },

  41573. 

  41574. #define osQueryPerformanceCounter ((BOOL(WINAPI*)( \

  41575.         LARGE_INTEGER*))aSyscall[51].pCurrent)

  41576. 

  41577.   { "ReadFile",                (SYSCALL)ReadFile,                0 },

  41578. 

  41579. #define osReadFile ((BOOL(WINAPI*)(HANDLE,LPVOID,DWORD,LPDWORD, \

  41580.         LPOVERLAPPED))aSyscall[52].pCurrent)

  41581. 

  41582.   { "SetEndOfFile",            (SYSCALL)SetEndOfFile,            0 },

  41583. 

  41584. #define osSetEndOfFile ((BOOL(WINAPI*)(HANDLE))aSyscall[53].pCurrent)

  41585. 

  41586. #if !SQLITE_OS_WINRT

  41587.   { "SetFilePointer",          (SYSCALL)SetFilePointer,          0 },

  41588. #else

  41589.   { "SetFilePointer",          (SYSCALL)0,                       0 },

  41590. #endif

  41591. 

  41592. #define osSetFilePointer ((DWORD(WINAPI*)(HANDLE,LONG,PLONG, \

  41593.         DWORD))aSyscall[54].pCurrent)

  41594. 

  41595. #if !SQLITE_OS_WINRT

  41596.   { "Sleep",                   (SYSCALL)Sleep,                   0 },

  41597. #else

  41598.   { "Sleep",                   (SYSCALL)0,                       0 },

  41599. #endif

  41600. 

  41601. #define osSleep ((VOID(WINAPI*)(DWORD))aSyscall[55].pCurrent)

  41602. 

  41603.   { "SystemTimeToFileTime",    (SYSCALL)SystemTimeToFileTime,    0 },

  41604. 

  41605. #define osSystemTimeToFileTime ((BOOL(WINAPI*)(CONST SYSTEMTIME*, \

  41606.         LPFILETIME))aSyscall[56].pCurrent)

  41607. 

  41608. #if !SQLITE_OS_WINCE && !SQLITE_OS_WINRT

  41609.   { "UnlockFile",              (SYSCALL)UnlockFile,              0 },

  41610. #else

  41611.   { "UnlockFile",              (SYSCALL)0,                       0 },

  41612. #endif

  41613. 

  41614. #ifndef osUnlockFile

  41615. #define osUnlockFile ((BOOL(WINAPI*)(HANDLE,DWORD,DWORD,DWORD, \

  41616.         DWORD))aSyscall[57].pCurrent)

  41617. #endif

  41618. 

  41619. #if !SQLITE_OS_WINCE

  41620.   { "UnlockFileEx",            (SYSCALL)UnlockFileEx,            0 },

  41621. #else

  41622.   { "UnlockFileEx",            (SYSCALL)0,                       0 },

  41623. #endif

  41624. 

  41625. #define osUnlockFileEx ((BOOL(WINAPI*)(HANDLE,DWORD,DWORD,DWORD, \

  41626.         LPOVERLAPPED))aSyscall[58].pCurrent)

  41627. 

  41628. #if SQLITE_OS_WINCE || !defined(SQLITE_OMIT_WAL) || SQLITE_MAX_MMAP_SIZE>0

  41629.   { "UnmapViewOfFile",         (SYSCALL)UnmapViewOfFile,         0 },

  41630. #else

  41631.   { "UnmapViewOfFile",         (SYSCALL)0,                       0 },

  41632. #endif

  41633. 

  41634. #define osUnmapViewOfFile ((BOOL(WINAPI*)(LPCVOID))aSyscall[59].pCurrent)

  41635. 

  41636.   { "WideCharToMultiByte",     (SYSCALL)WideCharToMultiByte,     0 },

  41637. 

  41638. #define osWideCharToMultiByte ((int(WINAPI*)(UINT,DWORD,LPCWSTR,int,LPSTR,int, \

  41639.         LPCSTR,LPBOOL))aSyscall[60].pCurrent)

  41640. 

  41641.   { "WriteFile",               (SYSCALL)WriteFile,               0 },

  41642. 

  41643. #define osWriteFile ((BOOL(WINAPI*)(HANDLE,LPCVOID,DWORD,LPDWORD, \

  41644.         LPOVERLAPPED))aSyscall[61].pCurrent)

  41645. 

  41646. #if SQLITE_OS_WINRT

  41647.   { "CreateEventExW",          (SYSCALL)CreateEventExW,          0 },

  41648. #else

  41649.   { "CreateEventExW",          (SYSCALL)0,                       0 },

  41650. #endif

  41651. 

  41652. #define osCreateEventExW ((HANDLE(WINAPI*)(LPSECURITY_ATTRIBUTES,LPCWSTR, \

  41653.         DWORD,DWORD))aSyscall[62].pCurrent)

  41654. 

  41655. #if !SQLITE_OS_WINRT

  41656.   { "WaitForSingleObject",     (SYSCALL)WaitForSingleObject,     0 },

  41657. #else

  41658.   { "WaitForSingleObject",     (SYSCALL)0,                       0 },

  41659. #endif

  41660. 

  41661. #define osWaitForSingleObject ((DWORD(WINAPI*)(HANDLE, \

  41662.         DWORD))aSyscall[63].pCurrent)

  41663. 

  41664. #if !SQLITE_OS_WINCE

  41665.   { "WaitForSingleObjectEx",   (SYSCALL)WaitForSingleObjectEx,   0 },

  41666. #else

  41667.   { "WaitForSingleObjectEx",   (SYSCALL)0,                       0 },

  41668. #endif

  41669. 

  41670. #define osWaitForSingleObjectEx ((DWORD(WINAPI*)(HANDLE,DWORD, \

  41671.         BOOL))aSyscall[64].pCurrent)

  41672. 

  41673. #if SQLITE_OS_WINRT

  41674.   { "SetFilePointerEx",        (SYSCALL)SetFilePointerEx,        0 },

  41675. #else

  41676.   { "SetFilePointerEx",        (SYSCALL)0,                       0 },

  41677. #endif

  41678. 

  41679. #define osSetFilePointerEx ((BOOL(WINAPI*)(HANDLE,LARGE_INTEGER, \

  41680.         PLARGE_INTEGER,DWORD))aSyscall[65].pCurrent)

  41681. 

  41682. #if SQLITE_OS_WINRT

  41683.   { "GetFileInformationByHandleEx", (SYSCALL)GetFileInformationByHandleEx, 0 },

  41684. #else

  41685.   { "GetFileInformationByHandleEx", (SYSCALL)0,                  0 },

  41686. #endif

  41687. 

  41688. #define osGetFileInformationByHandleEx ((BOOL(WINAPI*)(HANDLE, \

  41689.         FILE_INFO_BY_HANDLE_CLASS,LPVOID,DWORD))aSyscall[66].pCurrent)

  41690. 

  41691. #if SQLITE_OS_WINRT && (!defined(SQLITE_OMIT_WAL) || SQLITE_MAX_MMAP_SIZE>0)

  41692.   { "MapViewOfFileFromApp",    (SYSCALL)MapViewOfFileFromApp,    0 },

  41693. #else

  41694.   { "MapViewOfFileFromApp",    (SYSCALL)0,                       0 },

  41695. #endif

  41696. 

  41697. #define osMapViewOfFileFromApp ((LPVOID(WINAPI*)(HANDLE,ULONG,ULONG64, \

  41698.         SIZE_T))aSyscall[67].pCurrent)

  41699. 

  41700. #if SQLITE_OS_WINRT

  41701.   { "CreateFile2",             (SYSCALL)CreateFile2,             0 },

  41702. #else

  41703.   { "CreateFile2",             (SYSCALL)0,                       0 },

  41704. #endif

  41705. 

  41706. #define osCreateFile2 ((HANDLE(WINAPI*)(LPCWSTR,DWORD,DWORD,DWORD, \

  41707.         LPCREATEFILE2_EXTENDED_PARAMETERS))aSyscall[68].pCurrent)

  41708. 

  41709. #if SQLITE_OS_WINRT && !defined(SQLITE_OMIT_LOAD_EXTENSION)

  41710.   { "LoadPackagedLibrary",     (SYSCALL)LoadPackagedLibrary,     0 },

  41711. #else

  41712.   { "LoadPackagedLibrary",     (SYSCALL)0,                       0 },

  41713. #endif

  41714. 

  41715. #define osLoadPackagedLibrary ((HMODULE(WINAPI*)(LPCWSTR, \

  41716.         DWORD))aSyscall[69].pCurrent)

  41717. 

  41718. #if SQLITE_OS_WINRT

  41719.   { "GetTickCount64",          (SYSCALL)GetTickCount64,          0 },

  41720. #else

  41721.   { "GetTickCount64",          (SYSCALL)0,                       0 },

  41722. #endif

  41723. 

  41724. #define osGetTickCount64 ((ULONGLONG(WINAPI*)(VOID))aSyscall[70].pCurrent)

  41725. 

  41726. #if SQLITE_OS_WINRT

  41727.   { "GetNativeSystemInfo",     (SYSCALL)GetNativeSystemInfo,     0 },

  41728. #else

  41729.   { "GetNativeSystemInfo",     (SYSCALL)0,                       0 },

  41730. #endif

  41731. 

  41732. #define osGetNativeSystemInfo ((VOID(WINAPI*)( \

  41733.         LPSYSTEM_INFO))aSyscall[71].pCurrent)

  41734. 

  41735. #if defined(SQLITE_WIN32_HAS_ANSI)

  41736.   { "OutputDebugStringA",      (SYSCALL)OutputDebugStringA,      0 },

  41737. #else

  41738.   { "OutputDebugStringA",      (SYSCALL)0,                       0 },

  41739. #endif

  41740. 

  41741. #define osOutputDebugStringA ((VOID(WINAPI*)(LPCSTR))aSyscall[72].pCurrent)

  41742. 

  41743. #if defined(SQLITE_WIN32_HAS_WIDE)

  41744.   { "OutputDebugStringW",      (SYSCALL)OutputDebugStringW,      0 },

  41745. #else

  41746.   { "OutputDebugStringW",      (SYSCALL)0,                       0 },

  41747. #endif

  41748. 

  41749. #define osOutputDebugStringW ((VOID(WINAPI*)(LPCWSTR))aSyscall[73].pCurrent)

  41750. 

  41751.   { "GetProcessHeap",          (SYSCALL)GetProcessHeap,          0 },

  41752. 

  41753. #define osGetProcessHeap ((HANDLE(WINAPI*)(VOID))aSyscall[74].pCurrent)

  41754. 

  41755. #if SQLITE_OS_WINRT && (!defined(SQLITE_OMIT_WAL) || SQLITE_MAX_MMAP_SIZE>0)

  41756.   { "CreateFileMappingFromApp", (SYSCALL)CreateFileMappingFromApp, 0 },

  41757. #else

  41758.   { "CreateFileMappingFromApp", (SYSCALL)0,                      0 },

  41759. #endif

  41760. 

  41761. #define osCreateFileMappingFromApp ((HANDLE(WINAPI*)(HANDLE, \

  41762.         LPSECURITY_ATTRIBUTES,ULONG,ULONG64,LPCWSTR))aSyscall[75].pCurrent)

  41763. 

  41764. /*

  41765. ** NOTE: On some sub-platforms, the InterlockedCompareExchange "function"

  41766. **       is really just a macro that uses a compiler intrinsic (e.g. x64).

  41767. **       So do not try to make this is into a redefinable interface.

  41768. */

  41769. #if defined(InterlockedCompareExchange)

  41770.   { "InterlockedCompareExchange", (SYSCALL)0,                    0 },

  41771. 

  41772. #define osInterlockedCompareExchange InterlockedCompareExchange

  41773. #else

  41774.   { "InterlockedCompareExchange", (SYSCALL)InterlockedCompareExchange, 0 },

  41775. 

  41776. #define osInterlockedCompareExchange ((LONG(WINAPI*)(LONG \

  41777.         SQLITE_WIN32_VOLATILE*, LONG,LONG))aSyscall[76].pCurrent)

  41778. #endif /* defined(InterlockedCompareExchange) */

  41779. 

  41780. #if !SQLITE_OS_WINCE && !SQLITE_OS_WINRT && SQLITE_WIN32_USE_UUID

  41781.   { "UuidCreate",               (SYSCALL)UuidCreate,             0 },

  41782. #else

  41783.   { "UuidCreate",               (SYSCALL)0,                      0 },

  41784. #endif

  41785. 

  41786. #define osUuidCreate ((RPC_STATUS(RPC_ENTRY*)(UUID*))aSyscall[77].pCurrent)

  41787. 

  41788. #if !SQLITE_OS_WINCE && !SQLITE_OS_WINRT && SQLITE_WIN32_USE_UUID

  41789.   { "UuidCreateSequential",     (SYSCALL)UuidCreateSequential,   0 },

  41790. #else

  41791.   { "UuidCreateSequential",     (SYSCALL)0,                      0 },

  41792. #endif

  41793. 

  41794. #define osUuidCreateSequential \

  41795.         ((RPC_STATUS(RPC_ENTRY*)(UUID*))aSyscall[78].pCurrent)

  41796. 

  41797. #if !defined(SQLITE_NO_SYNC) && SQLITE_MAX_MMAP_SIZE>0

  41798.   { "FlushViewOfFile",          (SYSCALL)FlushViewOfFile,        0 },

  41799. #else

  41800.   { "FlushViewOfFile",          (SYSCALL)0,                      0 },

  41801. #endif

  41802. 

  41803. #define osFlushViewOfFile \

  41804.         ((BOOL(WINAPI*)(LPCVOID,SIZE_T))aSyscall[79].pCurrent)

  41805. 

  41806. }; /* End of the overrideable system calls */

  41807. 

  41808. /*

  41809. ** This is the xSetSystemCall() method of sqlite3_vfs for all of the

  41810. ** "win32" VFSes.  Return SQLITE_OK opon successfully updating the

  41811. ** system call pointer, or SQLITE_NOTFOUND if there is no configurable

  41812. ** system call named zName.

  41813. */

  41814. static int winSetSystemCall(

  41815.   sqlite3_vfs *pNotUsed,        /* The VFS pointer.  Not used */

  41816.   const char *zName,            /* Name of system call to override */

  41817.   sqlite3_syscall_ptr pNewFunc  /* Pointer to new system call value */

  41818. ){

  41819.   unsigned int i;

  41820.   int rc = SQLITE_NOTFOUND;

  41821. 

  41822.   UNUSED_PARAMETER(pNotUsed);

  41823.   if( zName==0 ){

  41824.     /* If no zName is given, restore all system calls to their default

  41825.     ** settings and return NULL

  41826.     */

  41827.     rc = SQLITE_OK;

  41828.     for(i=0; i<sizeof(aSyscall)/sizeof(aSyscall[0]); i++){

  41829.       if( aSyscall[i].pDefault ){

  41830.         aSyscall[i].pCurrent = aSyscall[i].pDefault;

  41831.       }

  41832.     }

  41833.   }else{

  41834.     /* If zName is specified, operate on only the one system call

  41835.     ** specified.

  41836.     */

  41837.     for(i=0; i<sizeof(aSyscall)/sizeof(aSyscall[0]); i++){

  41838.       if( strcmp(zName, aSyscall[i].zName)==0 ){

  41839.         if( aSyscall[i].pDefault==0 ){

  41840.           aSyscall[i].pDefault = aSyscall[i].pCurrent;

  41841.         }

  41842.         rc = SQLITE_OK;

  41843.         if( pNewFunc==0 ) pNewFunc = aSyscall[i].pDefault;

  41844.         aSyscall[i].pCurrent = pNewFunc;

  41845.         break;

  41846.       }

  41847.     }

  41848.   }

  41849.   return rc;

  41850. }

  41851. 

  41852. /*

  41853. ** Return the value of a system call.  Return NULL if zName is not a

  41854. ** recognized system call name.  NULL is also returned if the system call

  41855. ** is currently undefined.

  41856. */

  41857. static sqlite3_syscall_ptr winGetSystemCall(

  41858.   sqlite3_vfs *pNotUsed,

  41859.   const char *zName

  41860. ){

  41861.   unsigned int i;

  41862. 

  41863.   UNUSED_PARAMETER(pNotUsed);

  41864.   for(i=0; i<sizeof(aSyscall)/sizeof(aSyscall[0]); i++){

  41865.     if( strcmp(zName, aSyscall[i].zName)==0 ) return aSyscall[i].pCurrent;

  41866.   }

  41867.   return 0;

  41868. }

  41869. 

  41870. /*

  41871. ** Return the name of the first system call after zName.  If zName==NULL

  41872. ** then return the name of the first system call.  Return NULL if zName

  41873. ** is the last system call or if zName is not the name of a valid

  41874. ** system call.

  41875. */

  41876. static const char *winNextSystemCall(sqlite3_vfs *p, const char *zName){

  41877.   int i = -1;

  41878. 

  41879.   UNUSED_PARAMETER(p);

  41880.   if( zName ){

  41881.     for(i=0; i<ArraySize(aSyscall)-1; i++){

  41882.       if( strcmp(zName, aSyscall[i].zName)==0 ) break;

  41883.     }

  41884.   }

  41885.   for(i++; i<ArraySize(aSyscall); i++){

  41886.     if( aSyscall[i].pCurrent!=0 ) return aSyscall[i].zName;

  41887.   }

  41888.   return 0;

  41889. }

  41890. 

  41891. #ifdef SQLITE_WIN32_MALLOC

  41892. /*

  41893. ** If a Win32 native heap has been configured, this function will attempt to

  41894. ** compact it.  Upon success, SQLITE_OK will be returned.  Upon failure, one

  41895. ** of SQLITE_NOMEM, SQLITE_ERROR, or SQLITE_NOTFOUND will be returned.  The

  41896. ** "pnLargest" argument, if non-zero, will be used to return the size of the

  41897. ** largest committed free block in the heap, in bytes.

  41898. */

  41899. SQLITE_API int sqlite3_win32_compact_heap(LPUINT pnLargest){

  41900.   int rc = SQLITE_OK;

  41901.   UINT nLargest = 0;

  41902.   HANDLE hHeap;

  41903. 

  41904.   winMemAssertMagic();

  41905.   hHeap = winMemGetHeap();

  41906.   assert( hHeap!=0 );

  41907.   assert( hHeap!=INVALID_HANDLE_VALUE );

  41908. #if !SQLITE_OS_WINRT && defined(SQLITE_WIN32_MALLOC_VALIDATE)

  41909.   assert( osHeapValidate(hHeap, SQLITE_WIN32_HEAP_FLAGS, NULL) );

  41910. #endif

  41911. #if !SQLITE_OS_WINCE && !SQLITE_OS_WINRT

  41912.   if( (nLargest=osHeapCompact(hHeap, SQLITE_WIN32_HEAP_FLAGS))==0 ){

  41913.     DWORD lastErrno = osGetLastError();

  41914.     if( lastErrno==NO_ERROR ){

  41915.       sqlite3_log(SQLITE_NOMEM, "failed to HeapCompact (no space), heap=%p",

  41916.                   (void*)hHeap);

  41917.       rc = SQLITE_NOMEM_BKPT;

  41918.     }else{

  41919.       sqlite3_log(SQLITE_ERROR, "failed to HeapCompact (%lu), heap=%p",

  41920.                   osGetLastError(), (void*)hHeap);

  41921.       rc = SQLITE_ERROR;

  41922.     }

  41923.   }

  41924. #else

  41925.   sqlite3_log(SQLITE_NOTFOUND, "failed to HeapCompact, heap=%p",

  41926.               (void*)hHeap);

  41927.   rc = SQLITE_NOTFOUND;

  41928. #endif

  41929.   if( pnLargest ) *pnLargest = nLargest;

  41930.   return rc;

  41931. }

  41932. 

  41933. /*

  41934. ** If a Win32 native heap has been configured, this function will attempt to

  41935. ** destroy and recreate it.  If the Win32 native heap is not isolated and/or

  41936. ** the sqlite3_memory_used() function does not return zero, SQLITE_BUSY will

  41937. ** be returned and no changes will be made to the Win32 native heap.

  41938. */

  41939. SQLITE_API int sqlite3_win32_reset_heap(){

  41940.   int rc;

  41941.   MUTEX_LOGIC( sqlite3_mutex *pMaster; ) /* The main static mutex */

  41942.   MUTEX_LOGIC( sqlite3_mutex *pMem; )    /* The memsys static mutex */

  41943.   MUTEX_LOGIC( pMaster = sqlite3MutexAlloc(SQLITE_MUTEX_STATIC_MASTER); )

  41944.   MUTEX_LOGIC( pMem = sqlite3MutexAlloc(SQLITE_MUTEX_STATIC_MEM); )

  41945.   sqlite3_mutex_enter(pMaster);

  41946.   sqlite3_mutex_enter(pMem);

  41947.   winMemAssertMagic();

  41948.   if( winMemGetHeap()!=NULL && winMemGetOwned() && sqlite3_memory_used()==0 ){

  41949.     /*

  41950.     ** At this point, there should be no outstanding memory allocations on

  41951.     ** the heap.  Also, since both the master and memsys locks are currently

  41952.     ** being held by us, no other function (i.e. from another thread) should

  41953.     ** be able to even access the heap.  Attempt to destroy and recreate our

  41954.     ** isolated Win32 native heap now.

  41955.     */

  41956.     assert( winMemGetHeap()!=NULL );

  41957.     assert( winMemGetOwned() );

  41958.     assert( sqlite3_memory_used()==0 );

  41959.     winMemShutdown(winMemGetDataPtr());

  41960.     assert( winMemGetHeap()==NULL );

  41961.     assert( !winMemGetOwned() );

  41962.     assert( sqlite3_memory_used()==0 );

  41963.     rc = winMemInit(winMemGetDataPtr());

  41964.     assert( rc!=SQLITE_OK || winMemGetHeap()!=NULL );

  41965.     assert( rc!=SQLITE_OK || winMemGetOwned() );

  41966.     assert( rc!=SQLITE_OK || sqlite3_memory_used()==0 );

  41967.   }else{

  41968.     /*

  41969.     ** The Win32 native heap cannot be modified because it may be in use.

  41970.     */

  41971.     rc = SQLITE_BUSY;

  41972.   }

  41973.   sqlite3_mutex_leave(pMem);

  41974.   sqlite3_mutex_leave(pMaster);

  41975.   return rc;

  41976. }

  41977. #endif /* SQLITE_WIN32_MALLOC */

  41978. 

  41979. /*

  41980. ** This function outputs the specified (ANSI) string to the Win32 debugger

  41981. ** (if available).

  41982. */

  41983. 

  41984. SQLITE_API void sqlite3_win32_write_debug(const char *zBuf, int nBuf){

  41985.   char zDbgBuf[SQLITE_WIN32_DBG_BUF_SIZE];

  41986.   int nMin = MIN(nBuf, (SQLITE_WIN32_DBG_BUF_SIZE - 1)); /* may be negative. */

  41987.   if( nMin<-1 ) nMin = -1; /* all negative values become -1. */

  41988.   assert( nMin==-1 || nMin==0 || nMin<SQLITE_WIN32_DBG_BUF_SIZE );

  41989. #ifdef SQLITE_ENABLE_API_ARMOR

  41990.   if( !zBuf ){

  41991.     (void)SQLITE_MISUSE_BKPT;

  41992.     return;

  41993.   }

  41994. #endif

  41995. #if defined(SQLITE_WIN32_HAS_ANSI)

  41996.   if( nMin>0 ){

  41997.     memset(zDbgBuf, 0, SQLITE_WIN32_DBG_BUF_SIZE);

  41998.     memcpy(zDbgBuf, zBuf, nMin);

  41999.     osOutputDebugStringA(zDbgBuf);

  42000.   }else{

  42001.     osOutputDebugStringA(zBuf);

  42002.   }

  42003. #elif defined(SQLITE_WIN32_HAS_WIDE)

  42004.   memset(zDbgBuf, 0, SQLITE_WIN32_DBG_BUF_SIZE);

  42005.   if ( osMultiByteToWideChar(

  42006.           osAreFileApisANSI() ? CP_ACP : CP_OEMCP, 0, zBuf,

  42007.           nMin, (LPWSTR)zDbgBuf, SQLITE_WIN32_DBG_BUF_SIZE/sizeof(WCHAR))<=0 ){

  42008.     return;

  42009.   }

  42010.   osOutputDebugStringW((LPCWSTR)zDbgBuf);

  42011. #else

  42012.   if( nMin>0 ){

  42013.     memset(zDbgBuf, 0, SQLITE_WIN32_DBG_BUF_SIZE);

  42014.     memcpy(zDbgBuf, zBuf, nMin);

  42015.     fprintf(stderr, "%s", zDbgBuf);

  42016.   }else{

  42017.     fprintf(stderr, "%s", zBuf);

  42018.   }

  42019. #endif

  42020. }

  42021. 

  42022. /*

  42023. ** The following routine suspends the current thread for at least ms

  42024. ** milliseconds.  This is equivalent to the Win32 Sleep() interface.

  42025. */

  42026. #if SQLITE_OS_WINRT

  42027. static HANDLE sleepObj = NULL;

  42028. #endif

  42029. 

  42030. SQLITE_API void sqlite3_win32_sleep(DWORD milliseconds){

  42031. #if SQLITE_OS_WINRT

  42032.   if ( sleepObj==NULL ){

  42033.     sleepObj = osCreateEventExW(NULL, NULL, CREATE_EVENT_MANUAL_RESET,

  42034.                                 SYNCHRONIZE);

  42035.   }

  42036.   assert( sleepObj!=NULL );

  42037.   osWaitForSingleObjectEx(sleepObj, milliseconds, FALSE);

  42038. #else

  42039.   osSleep(milliseconds);

  42040. #endif

  42041. }

  42042. 

  42043. #if SQLITE_MAX_WORKER_THREADS>0 && !SQLITE_OS_WINCE && !SQLITE_OS_WINRT && \

  42044.         SQLITE_THREADSAFE>0

  42045. SQLITE_PRIVATE DWORD sqlite3Win32Wait(HANDLE hObject){

  42046.   DWORD rc;

  42047.   while( (rc = osWaitForSingleObjectEx(hObject, INFINITE,

  42048.                                        TRUE))==WAIT_IO_COMPLETION ){}

  42049.   return rc;

  42050. }

  42051. #endif

  42052. 

  42053. /*

  42054. ** Return true (non-zero) if we are running under WinNT, Win2K, WinXP,

  42055. ** or WinCE.  Return false (zero) for Win95, Win98, or WinME.

  42056. **

  42057. ** Here is an interesting observation:  Win95, Win98, and WinME lack

  42058. ** the LockFileEx() API.  But we can still statically link against that

  42059. ** API as long as we don't call it when running Win95/98/ME.  A call to

  42060. ** this routine is used to determine if the host is Win95/98/ME or

  42061. ** WinNT/2K/XP so that we will know whether or not we can safely call

  42062. ** the LockFileEx() API.

  42063. */

  42064. 

  42065. #if !SQLITE_WIN32_GETVERSIONEX

  42066. # define osIsNT()  (1)

  42067. #elif SQLITE_OS_WINCE || SQLITE_OS_WINRT || !defined(SQLITE_WIN32_HAS_ANSI)

  42068. # define osIsNT()  (1)

  42069. #elif !defined(SQLITE_WIN32_HAS_WIDE)

  42070. # define osIsNT()  (0)

  42071. #else

  42072. # define osIsNT()  ((sqlite3_os_type==2) || sqlite3_win32_is_nt())

  42073. #endif

  42074. 

  42075. /*

  42076. ** This function determines if the machine is running a version of Windows

  42077. ** based on the NT kernel.

  42078. */

  42079. SQLITE_API int sqlite3_win32_is_nt(void){

  42080. #if SQLITE_OS_WINRT

  42081.   /*

  42082.   ** NOTE: The WinRT sub-platform is always assumed to be based on the NT

  42083.   **       kernel.

  42084.   */

  42085.   return 1;

  42086. #elif SQLITE_WIN32_GETVERSIONEX

  42087.   if( osInterlockedCompareExchange(&sqlite3_os_type, 0, 0)==0 ){

  42088. #if defined(SQLITE_WIN32_HAS_ANSI)

  42089.     OSVERSIONINFOA sInfo;

  42090.     sInfo.dwOSVersionInfoSize = sizeof(sInfo);

  42091.     osGetVersionExA(&sInfo);

  42092.     osInterlockedCompareExchange(&sqlite3_os_type,

  42093.         (sInfo.dwPlatformId == VER_PLATFORM_WIN32_NT) ? 2 : 1, 0);

  42094. #elif defined(SQLITE_WIN32_HAS_WIDE)

  42095.     OSVERSIONINFOW sInfo;

  42096.     sInfo.dwOSVersionInfoSize = sizeof(sInfo);

  42097.     osGetVersionExW(&sInfo);

  42098.     osInterlockedCompareExchange(&sqlite3_os_type,

  42099.         (sInfo.dwPlatformId == VER_PLATFORM_WIN32_NT) ? 2 : 1, 0);

  42100. #endif

  42101.   }

  42102.   return osInterlockedCompareExchange(&sqlite3_os_type, 2, 2)==2;

  42103. #elif SQLITE_TEST

  42104.   return osInterlockedCompareExchange(&sqlite3_os_type, 2, 2)==2;

  42105. #else

  42106.   /*

  42107.   ** NOTE: All sub-platforms where the GetVersionEx[AW] functions are

  42108.   **       deprecated are always assumed to be based on the NT kernel.

  42109.   */

  42110.   return 1;

  42111. #endif

  42112. }

  42113. 

  42114. #ifdef SQLITE_WIN32_MALLOC

  42115. /*

  42116. ** Allocate nBytes of memory.

  42117. */

  42118. static void *winMemMalloc(int nBytes){

  42119.   HANDLE hHeap;

  42120.   void *p;

  42121. 

  42122.   winMemAssertMagic();

  42123.   hHeap = winMemGetHeap();

  42124.   assert( hHeap!=0 );

  42125.   assert( hHeap!=INVALID_HANDLE_VALUE );

  42126. #if !SQLITE_OS_WINRT && defined(SQLITE_WIN32_MALLOC_VALIDATE)

  42127.   assert( osHeapValidate(hHeap, SQLITE_WIN32_HEAP_FLAGS, NULL) );

  42128. #endif

  42129.   assert( nBytes>=0 );

  42130.   p = osHeapAlloc(hHeap, SQLITE_WIN32_HEAP_FLAGS, (SIZE_T)nBytes);

  42131.   if( !p ){

  42132.     sqlite3_log(SQLITE_NOMEM, "failed to HeapAlloc %u bytes (%lu), heap=%p",

  42133.                 nBytes, osGetLastError(), (void*)hHeap);

  42134.   }

  42135.   return p;

  42136. }

  42137. 

  42138. /*

  42139. ** Free memory.

  42140. */

  42141. static void winMemFree(void *pPrior){

  42142.   HANDLE hHeap;

  42143. 

  42144.   winMemAssertMagic();

  42145.   hHeap = winMemGetHeap();

  42146.   assert( hHeap!=0 );

  42147.   assert( hHeap!=INVALID_HANDLE_VALUE );

  42148. #if !SQLITE_OS_WINRT && defined(SQLITE_WIN32_MALLOC_VALIDATE)

  42149.   assert( osHeapValidate(hHeap, SQLITE_WIN32_HEAP_FLAGS, pPrior) );

  42150. #endif

  42151.   if( !pPrior ) return; /* Passing NULL to HeapFree is undefined. */

  42152.   if( !osHeapFree(hHeap, SQLITE_WIN32_HEAP_FLAGS, pPrior) ){

  42153.     sqlite3_log(SQLITE_NOMEM, "failed to HeapFree block %p (%lu), heap=%p",

  42154.                 pPrior, osGetLastError(), (void*)hHeap);

  42155.   }

  42156. }

  42157. 

  42158. /*

  42159. ** Change the size of an existing memory allocation

  42160. */

  42161. static void *winMemRealloc(void *pPrior, int nBytes){

  42162.   HANDLE hHeap;

  42163.   void *p;

  42164. 

  42165.   winMemAssertMagic();

  42166.   hHeap = winMemGetHeap();

  42167.   assert( hHeap!=0 );

  42168.   assert( hHeap!=INVALID_HANDLE_VALUE );

  42169. #if !SQLITE_OS_WINRT && defined(SQLITE_WIN32_MALLOC_VALIDATE)

  42170.   assert( osHeapValidate(hHeap, SQLITE_WIN32_HEAP_FLAGS, pPrior) );

  42171. #endif

  42172.   assert( nBytes>=0 );

  42173.   if( !pPrior ){

  42174.     p = osHeapAlloc(hHeap, SQLITE_WIN32_HEAP_FLAGS, (SIZE_T)nBytes);

  42175.   }else{

  42176.     p = osHeapReAlloc(hHeap, SQLITE_WIN32_HEAP_FLAGS, pPrior, (SIZE_T)nBytes);

  42177.   }

  42178.   if( !p ){

  42179.     sqlite3_log(SQLITE_NOMEM, "failed to %s %u bytes (%lu), heap=%p",

  42180.                 pPrior ? "HeapReAlloc" : "HeapAlloc", nBytes, osGetLastError(),

  42181.                 (void*)hHeap);

  42182.   }

  42183.   return p;

  42184. }

  42185. 

  42186. /*

  42187. ** Return the size of an outstanding allocation, in bytes.

  42188. */

  42189. static int winMemSize(void *p){

  42190.   HANDLE hHeap;

  42191.   SIZE_T n;

  42192. 

  42193.   winMemAssertMagic();

  42194.   hHeap = winMemGetHeap();

  42195.   assert( hHeap!=0 );

  42196.   assert( hHeap!=INVALID_HANDLE_VALUE );

  42197. #if !SQLITE_OS_WINRT && defined(SQLITE_WIN32_MALLOC_VALIDATE)

  42198.   assert( osHeapValidate(hHeap, SQLITE_WIN32_HEAP_FLAGS, p) );

  42199. #endif

  42200.   if( !p ) return 0;

  42201.   n = osHeapSize(hHeap, SQLITE_WIN32_HEAP_FLAGS, p);

  42202.   if( n==(SIZE_T)-1 ){

  42203.     sqlite3_log(SQLITE_NOMEM, "failed to HeapSize block %p (%lu), heap=%p",

  42204.                 p, osGetLastError(), (void*)hHeap);

  42205.     return 0;

  42206.   }

  42207.   return (int)n;

  42208. }

  42209. 

  42210. /*

  42211. ** Round up a request size to the next valid allocation size.

  42212. */

  42213. static int winMemRoundup(int n){

  42214.   return n;

  42215. }

  42216. 

  42217. /*

  42218. ** Initialize this module.

  42219. */

  42220. static int winMemInit(void *pAppData){

  42221.   winMemData *pWinMemData = (winMemData *)pAppData;

  42222. 

  42223.   if( !pWinMemData ) return SQLITE_ERROR;

  42224.   assert( pWinMemData->magic1==WINMEM_MAGIC1 );

  42225.   assert( pWinMemData->magic2==WINMEM_MAGIC2 );

  42226. 

  42227. #if !SQLITE_OS_WINRT && SQLITE_WIN32_HEAP_CREATE

  42228.   if( !pWinMemData->hHeap ){

  42229.     DWORD dwInitialSize = SQLITE_WIN32_HEAP_INIT_SIZE;

  42230.     DWORD dwMaximumSize = (DWORD)sqlite3GlobalConfig.nHeap;

  42231.     if( dwMaximumSize==0 ){

  42232.       dwMaximumSize = SQLITE_WIN32_HEAP_MAX_SIZE;

  42233.     }else if( dwInitialSize>dwMaximumSize ){

  42234.       dwInitialSize = dwMaximumSize;

  42235.     }

  42236.     pWinMemData->hHeap = osHeapCreate(SQLITE_WIN32_HEAP_FLAGS,

  42237.                                       dwInitialSize, dwMaximumSize);

  42238.     if( !pWinMemData->hHeap ){

  42239.       sqlite3_log(SQLITE_NOMEM,

  42240.           "failed to HeapCreate (%lu), flags=%u, initSize=%lu, maxSize=%lu",

  42241.           osGetLastError(), SQLITE_WIN32_HEAP_FLAGS, dwInitialSize,

  42242.           dwMaximumSize);

  42243.       return SQLITE_NOMEM_BKPT;

  42244.     }

  42245.     pWinMemData->bOwned = TRUE;

  42246.     assert( pWinMemData->bOwned );

  42247.   }

  42248. #else

  42249.   pWinMemData->hHeap = osGetProcessHeap();

  42250.   if( !pWinMemData->hHeap ){

  42251.     sqlite3_log(SQLITE_NOMEM,

  42252.         "failed to GetProcessHeap (%lu)", osGetLastError());

  42253.     return SQLITE_NOMEM_BKPT;

  42254.   }

  42255.   pWinMemData->bOwned = FALSE;

  42256.   assert( !pWinMemData->bOwned );

  42257. #endif

  42258.   assert( pWinMemData->hHeap!=0 );

  42259.   assert( pWinMemData->hHeap!=INVALID_HANDLE_VALUE );

  42260. #if !SQLITE_OS_WINRT && defined(SQLITE_WIN32_MALLOC_VALIDATE)

  42261.   assert( osHeapValidate(pWinMemData->hHeap, SQLITE_WIN32_HEAP_FLAGS, NULL) );

  42262. #endif

  42263.   return SQLITE_OK;

  42264. }

  42265. 

  42266. /*

  42267. ** Deinitialize this module.

  42268. */

  42269. static void winMemShutdown(void *pAppData){

  42270.   winMemData *pWinMemData = (winMemData *)pAppData;

  42271. 

  42272.   if( !pWinMemData ) return;

  42273.   assert( pWinMemData->magic1==WINMEM_MAGIC1 );

  42274.   assert( pWinMemData->magic2==WINMEM_MAGIC2 );

  42275. 

  42276.   if( pWinMemData->hHeap ){

  42277.     assert( pWinMemData->hHeap!=INVALID_HANDLE_VALUE );

  42278. #if !SQLITE_OS_WINRT && defined(SQLITE_WIN32_MALLOC_VALIDATE)

  42279.     assert( osHeapValidate(pWinMemData->hHeap, SQLITE_WIN32_HEAP_FLAGS, NULL) );

  42280. #endif

  42281.     if( pWinMemData->bOwned ){

  42282.       if( !osHeapDestroy(pWinMemData->hHeap) ){

  42283.         sqlite3_log(SQLITE_NOMEM, "failed to HeapDestroy (%lu), heap=%p",

  42284.                     osGetLastError(), (void*)pWinMemData->hHeap);

  42285.       }

  42286.       pWinMemData->bOwned = FALSE;

  42287.     }

  42288.     pWinMemData->hHeap = NULL;

  42289.   }

  42290. }

  42291. 

  42292. /*

  42293. ** Populate the low-level memory allocation function pointers in

  42294. ** sqlite3GlobalConfig.m with pointers to the routines in this file. The

  42295. ** arguments specify the block of memory to manage.

  42296. **

  42297. ** This routine is only called by sqlite3_config(), and therefore

  42298. ** is not required to be threadsafe (it is not).

  42299. */

  42300. SQLITE_PRIVATE const sqlite3_mem_methods *sqlite3MemGetWin32(void){

  42301.   static const sqlite3_mem_methods winMemMethods = {

  42302.     winMemMalloc,

  42303.     winMemFree,

  42304.     winMemRealloc,

  42305.     winMemSize,

  42306.     winMemRoundup,

  42307.     winMemInit,

  42308.     winMemShutdown,

  42309.     &win_mem_data

  42310.   };

  42311.   return &winMemMethods;

  42312. }

  42313. 

  42314. SQLITE_PRIVATE void sqlite3MemSetDefault(void){

  42315.   sqlite3_config(SQLITE_CONFIG_MALLOC, sqlite3MemGetWin32());

  42316. }

  42317. #endif /* SQLITE_WIN32_MALLOC */

  42318. 

  42319. /*

  42320. ** Convert a UTF-8 string to Microsoft Unicode.

  42321. **

  42322. ** Space to hold the returned string is obtained from sqlite3_malloc().

  42323. */

  42324. static LPWSTR winUtf8ToUnicode(const char *zText){

  42325.   int nChar;

  42326.   LPWSTR zWideText;

  42327. 

  42328.   nChar = osMultiByteToWideChar(CP_UTF8, 0, zText, -1, NULL, 0);

  42329.   if( nChar==0 ){

  42330.     return 0;

  42331.   }

  42332.   zWideText = sqlite3MallocZero( nChar*sizeof(WCHAR) );

  42333.   if( zWideText==0 ){

  42334.     return 0;

  42335.   }

  42336.   nChar = osMultiByteToWideChar(CP_UTF8, 0, zText, -1, zWideText,

  42337.                                 nChar);

  42338.   if( nChar==0 ){

  42339.     sqlite3_free(zWideText);

  42340.     zWideText = 0;

  42341.   }

  42342.   return zWideText;

  42343. }

  42344. 

  42345. /*

  42346. ** Convert a Microsoft Unicode string to UTF-8.

  42347. **

  42348. ** Space to hold the returned string is obtained from sqlite3_malloc().

  42349. */

  42350. static char *winUnicodeToUtf8(LPCWSTR zWideText){

  42351.   int nByte;

  42352.   char *zText;

  42353. 

  42354.   nByte = osWideCharToMultiByte(CP_UTF8, 0, zWideText, -1, 0, 0, 0, 0);

  42355.   if( nByte == 0 ){

  42356.     return 0;

  42357.   }

  42358.   zText = sqlite3MallocZero( nByte );

  42359.   if( zText==0 ){

  42360.     return 0;

  42361.   }

  42362.   nByte = osWideCharToMultiByte(CP_UTF8, 0, zWideText, -1, zText, nByte,

  42363.                                 0, 0);

  42364.   if( nByte == 0 ){

  42365.     sqlite3_free(zText);

  42366.     zText = 0;

  42367.   }

  42368.   return zText;

  42369. }

  42370. 

  42371. /*

  42372. ** Convert an ANSI string to Microsoft Unicode, using the ANSI or OEM

  42373. ** code page.

  42374. **

  42375. ** Space to hold the returned string is obtained from sqlite3_malloc().

  42376. */

  42377. static LPWSTR winMbcsToUnicode(const char *zText, int useAnsi){

  42378.   int nByte;

  42379.   LPWSTR zMbcsText;

  42380.   int codepage = useAnsi ? CP_ACP : CP_OEMCP;

  42381. 

  42382.   nByte = osMultiByteToWideChar(codepage, 0, zText, -1, NULL,

  42383.                                 0)*sizeof(WCHAR);

  42384.   if( nByte==0 ){

  42385.     return 0;

  42386.   }

  42387.   zMbcsText = sqlite3MallocZero( nByte*sizeof(WCHAR) );

  42388.   if( zMbcsText==0 ){

  42389.     return 0;

  42390.   }

  42391.   nByte = osMultiByteToWideChar(codepage, 0, zText, -1, zMbcsText,

  42392.                                 nByte);

  42393.   if( nByte==0 ){

  42394.     sqlite3_free(zMbcsText);

  42395.     zMbcsText = 0;

  42396.   }

  42397.   return zMbcsText;

  42398. }

  42399. 

  42400. /*

  42401. ** Convert a Microsoft Unicode string to a multi-byte character string,

  42402. ** using the ANSI or OEM code page.

  42403. **

  42404. ** Space to hold the returned string is obtained from sqlite3_malloc().

  42405. */

  42406. static char *winUnicodeToMbcs(LPCWSTR zWideText, int useAnsi){

  42407.   int nByte;

  42408.   char *zText;

  42409.   int codepage = useAnsi ? CP_ACP : CP_OEMCP;

  42410. 

  42411.   nByte = osWideCharToMultiByte(codepage, 0, zWideText, -1, 0, 0, 0, 0);

  42412.   if( nByte == 0 ){

  42413.     return 0;

  42414.   }

  42415.   zText = sqlite3MallocZero( nByte );

  42416.   if( zText==0 ){

  42417.     return 0;

  42418.   }

  42419.   nByte = osWideCharToMultiByte(codepage, 0, zWideText, -1, zText,

  42420.                                 nByte, 0, 0);

  42421.   if( nByte == 0 ){

  42422.     sqlite3_free(zText);

  42423.     zText = 0;

  42424.   }

  42425.   return zText;

  42426. }

  42427. 

  42428. /*

  42429. ** Convert a multi-byte character string to UTF-8.

  42430. **

  42431. ** Space to hold the returned string is obtained from sqlite3_malloc().

  42432. */

  42433. static char *winMbcsToUtf8(const char *zText, int useAnsi){

  42434.   char *zTextUtf8;

  42435.   LPWSTR zTmpWide;

  42436. 

  42437.   zTmpWide = winMbcsToUnicode(zText, useAnsi);

  42438.   if( zTmpWide==0 ){

  42439.     return 0;

  42440.   }

  42441.   zTextUtf8 = winUnicodeToUtf8(zTmpWide);

  42442.   sqlite3_free(zTmpWide);

  42443.   return zTextUtf8;

  42444. }

  42445. 

  42446. /*

  42447. ** Convert a UTF-8 string to a multi-byte character string.

  42448. **

  42449. ** Space to hold the returned string is obtained from sqlite3_malloc().

  42450. */

  42451. static char *winUtf8ToMbcs(const char *zText, int useAnsi){

  42452.   char *zTextMbcs;

  42453.   LPWSTR zTmpWide;

  42454. 

  42455.   zTmpWide = winUtf8ToUnicode(zText);

  42456.   if( zTmpWide==0 ){

  42457.     return 0;

  42458.   }

  42459.   zTextMbcs = winUnicodeToMbcs(zTmpWide, useAnsi);

  42460.   sqlite3_free(zTmpWide);

  42461.   return zTextMbcs;

  42462. }

  42463. 

  42464. /*

  42465. ** This is a public wrapper for the winUtf8ToUnicode() function.

  42466. */

  42467. SQLITE_API LPWSTR sqlite3_win32_utf8_to_unicode(const char *zText){

  42468. #ifdef SQLITE_ENABLE_API_ARMOR

  42469.   if( !zText ){

  42470.     (void)SQLITE_MISUSE_BKPT;

  42471.     return 0;

  42472.   }

  42473. #endif

  42474. #ifndef SQLITE_OMIT_AUTOINIT

  42475.   if( sqlite3_initialize() ) return 0;

  42476. #endif

  42477.   return winUtf8ToUnicode(zText);

  42478. }

  42479. 

  42480. /*

  42481. ** This is a public wrapper for the winUnicodeToUtf8() function.

  42482. */

  42483. SQLITE_API char *sqlite3_win32_unicode_to_utf8(LPCWSTR zWideText){

  42484. #ifdef SQLITE_ENABLE_API_ARMOR

  42485.   if( !zWideText ){

  42486.     (void)SQLITE_MISUSE_BKPT;

  42487.     return 0;

  42488.   }

  42489. #endif

  42490. #ifndef SQLITE_OMIT_AUTOINIT

  42491.   if( sqlite3_initialize() ) return 0;

  42492. #endif

  42493.   return winUnicodeToUtf8(zWideText);

  42494. }

  42495. 

  42496. /*

  42497. ** This is a public wrapper for the winMbcsToUtf8() function.

  42498. */

  42499. SQLITE_API char *sqlite3_win32_mbcs_to_utf8(const char *zText){

  42500. #ifdef SQLITE_ENABLE_API_ARMOR

  42501.   if( !zText ){

  42502.     (void)SQLITE_MISUSE_BKPT;

  42503.     return 0;

  42504.   }

  42505. #endif

  42506. #ifndef SQLITE_OMIT_AUTOINIT

  42507.   if( sqlite3_initialize() ) return 0;

  42508. #endif

  42509.   return winMbcsToUtf8(zText, osAreFileApisANSI());

  42510. }

  42511. 

  42512. /*

  42513. ** This is a public wrapper for the winMbcsToUtf8() function.

  42514. */

  42515. SQLITE_API char *sqlite3_win32_mbcs_to_utf8_v2(const char *zText, int useAnsi){

  42516. #ifdef SQLITE_ENABLE_API_ARMOR

  42517.   if( !zText ){

  42518.     (void)SQLITE_MISUSE_BKPT;

  42519.     return 0;

  42520.   }

  42521. #endif

  42522. #ifndef SQLITE_OMIT_AUTOINIT

  42523.   if( sqlite3_initialize() ) return 0;

  42524. #endif

  42525.   return winMbcsToUtf8(zText, useAnsi);

  42526. }

  42527. 

  42528. /*

  42529. ** This is a public wrapper for the winUtf8ToMbcs() function.

  42530. */

  42531. SQLITE_API char *sqlite3_win32_utf8_to_mbcs(const char *zText){

  42532. #ifdef SQLITE_ENABLE_API_ARMOR

  42533.   if( !zText ){

  42534.     (void)SQLITE_MISUSE_BKPT;

  42535.     return 0;

  42536.   }

  42537. #endif

  42538. #ifndef SQLITE_OMIT_AUTOINIT

  42539.   if( sqlite3_initialize() ) return 0;

  42540. #endif

  42541.   return winUtf8ToMbcs(zText, osAreFileApisANSI());

  42542. }

  42543. 

  42544. /*

  42545. ** This is a public wrapper for the winUtf8ToMbcs() function.

  42546. */

  42547. SQLITE_API char *sqlite3_win32_utf8_to_mbcs_v2(const char *zText, int useAnsi){

  42548. #ifdef SQLITE_ENABLE_API_ARMOR

  42549.   if( !zText ){

  42550.     (void)SQLITE_MISUSE_BKPT;

  42551.     return 0;

  42552.   }

  42553. #endif

  42554. #ifndef SQLITE_OMIT_AUTOINIT

  42555.   if( sqlite3_initialize() ) return 0;

  42556. #endif

  42557.   return winUtf8ToMbcs(zText, useAnsi);

  42558. }

  42559. 

  42560. /*

  42561. ** This function is the same as sqlite3_win32_set_directory (below); however,

  42562. ** it accepts a UTF-8 string.

  42563. */

  42564. SQLITE_API int sqlite3_win32_set_directory8(

  42565.   unsigned long type, /* Identifier for directory being set or reset */

  42566.   const char *zValue  /* New value for directory being set or reset */

  42567. ){

  42568.   char **ppDirectory = 0;

  42569. #ifndef SQLITE_OMIT_AUTOINIT

  42570.   int rc = sqlite3_initialize();

  42571.   if( rc ) return rc;

  42572. #endif

  42573.   if( type==SQLITE_WIN32_DATA_DIRECTORY_TYPE ){

  42574.     ppDirectory = &sqlite3_data_directory;

  42575.   }else if( type==SQLITE_WIN32_TEMP_DIRECTORY_TYPE ){

  42576.     ppDirectory = &sqlite3_temp_directory;

  42577.   }

  42578.   assert( !ppDirectory || type==SQLITE_WIN32_DATA_DIRECTORY_TYPE

  42579.           || type==SQLITE_WIN32_TEMP_DIRECTORY_TYPE

  42580.   );

  42581.   assert( !ppDirectory || sqlite3MemdebugHasType(*ppDirectory, MEMTYPE_HEAP) );

  42582.   if( ppDirectory ){

  42583.     char *zCopy = 0;

  42584.     if( zValue && zValue[0] ){

  42585.       zCopy = sqlite3_mprintf("%s", zValue);

  42586.       if ( zCopy==0 ){

  42587.         return SQLITE_NOMEM_BKPT;

  42588.       }

  42589.     }

  42590.     sqlite3_free(*ppDirectory);

  42591.     *ppDirectory = zCopy;

  42592.     return SQLITE_OK;

  42593.   }

  42594.   return SQLITE_ERROR;

  42595. }

  42596. 

  42597. /*

  42598. ** This function is the same as sqlite3_win32_set_directory (below); however,

  42599. ** it accepts a UTF-16 string.

  42600. */

  42601. SQLITE_API int sqlite3_win32_set_directory16(

  42602.   unsigned long type, /* Identifier for directory being set or reset */

  42603.   const void *zValue  /* New value for directory being set or reset */

  42604. ){

  42605.   int rc;

  42606.   char *zUtf8 = 0;

  42607.   if( zValue ){

  42608.     zUtf8 = sqlite3_win32_unicode_to_utf8(zValue);

  42609.     if( zUtf8==0 ) return SQLITE_NOMEM_BKPT;

  42610.   }

  42611.   rc = sqlite3_win32_set_directory8(type, zUtf8);

  42612.   if( zUtf8 ) sqlite3_free(zUtf8);

  42613.   return rc;

  42614. }

  42615. 

  42616. /*

  42617. ** This function sets the data directory or the temporary directory based on

  42618. ** the provided arguments.  The type argument must be 1 in order to set the

  42619. ** data directory or 2 in order to set the temporary directory.  The zValue

  42620. ** argument is the name of the directory to use.  The return value will be

  42621. ** SQLITE_OK if successful.

  42622. */

  42623. SQLITE_API int sqlite3_win32_set_directory(

  42624.   unsigned long type, /* Identifier for directory being set or reset */

  42625.   void *zValue        /* New value for directory being set or reset */

  42626. ){

  42627.   return sqlite3_win32_set_directory16(type, zValue);

  42628. }

  42629. 

  42630. /*

  42631. ** The return value of winGetLastErrorMsg

  42632. ** is zero if the error message fits in the buffer, or non-zero

  42633. ** otherwise (if the message was truncated).

  42634. */

  42635. static int winGetLastErrorMsg(DWORD lastErrno, int nBuf, char *zBuf){

  42636.   /* FormatMessage returns 0 on failure.  Otherwise it

  42637.   ** returns the number of TCHARs written to the output

  42638.   ** buffer, excluding the terminating null char.

  42639.   */

  42640.   DWORD dwLen = 0;

  42641.   char *zOut = 0;

  42642. 

  42643.   if( osIsNT() ){

  42644. #if SQLITE_OS_WINRT

  42645.     WCHAR zTempWide[SQLITE_WIN32_MAX_ERRMSG_CHARS+1];

  42646.     dwLen = osFormatMessageW(FORMAT_MESSAGE_FROM_SYSTEM |

  42647.                              FORMAT_MESSAGE_IGNORE_INSERTS,

  42648.                              NULL,

  42649.                              lastErrno,

  42650.                              0,

  42651.                              zTempWide,

  42652.                              SQLITE_WIN32_MAX_ERRMSG_CHARS,

  42653.                              0);

  42654. #else

  42655.     LPWSTR zTempWide = NULL;

  42656.     dwLen = osFormatMessageW(FORMAT_MESSAGE_ALLOCATE_BUFFER |

  42657.                              FORMAT_MESSAGE_FROM_SYSTEM |

  42658.                              FORMAT_MESSAGE_IGNORE_INSERTS,

  42659.                              NULL,

  42660.                              lastErrno,

  42661.                              0,

  42662.                              (LPWSTR) &zTempWide,

  42663.                              0,

  42664.                              0);

  42665. #endif

  42666.     if( dwLen > 0 ){

  42667.       /* allocate a buffer and convert to UTF8 */

  42668.       sqlite3BeginBenignMalloc();

  42669.       zOut = winUnicodeToUtf8(zTempWide);

  42670.       sqlite3EndBenignMalloc();

  42671. #if !SQLITE_OS_WINRT

  42672.       /* free the system buffer allocated by FormatMessage */

  42673.       osLocalFree(zTempWide);

  42674. #endif

  42675.     }

  42676.   }

  42677. #ifdef SQLITE_WIN32_HAS_ANSI

  42678.   else{

  42679.     char *zTemp = NULL;

  42680.     dwLen = osFormatMessageA(FORMAT_MESSAGE_ALLOCATE_BUFFER |

  42681.                              FORMAT_MESSAGE_FROM_SYSTEM |

  42682.                              FORMAT_MESSAGE_IGNORE_INSERTS,

  42683.                              NULL,

  42684.                              lastErrno,

  42685.                              0,

  42686.                              (LPSTR) &zTemp,

  42687.                              0,

  42688.                              0);

  42689.     if( dwLen > 0 ){

  42690.       /* allocate a buffer and convert to UTF8 */

  42691.       sqlite3BeginBenignMalloc();

  42692.       zOut = winMbcsToUtf8(zTemp, osAreFileApisANSI());

  42693.       sqlite3EndBenignMalloc();

  42694.       /* free the system buffer allocated by FormatMessage */

  42695.       osLocalFree(zTemp);

  42696.     }

  42697.   }

  42698. #endif

  42699.   if( 0 == dwLen ){

  42700.     sqlite3_snprintf(nBuf, zBuf, "OsError 0x%lx (%lu)", lastErrno, lastErrno);

  42701.   }else{

  42702.     /* copy a maximum of nBuf chars to output buffer */

  42703.     sqlite3_snprintf(nBuf, zBuf, "%s", zOut);

  42704.     /* free the UTF8 buffer */

  42705.     sqlite3_free(zOut);

  42706.   }

  42707.   return 0;

  42708. }

  42709. 

  42710. /*

  42711. **

  42712. ** This function - winLogErrorAtLine() - is only ever called via the macro

  42713. ** winLogError().

  42714. **

  42715. ** This routine is invoked after an error occurs in an OS function.

  42716. ** It logs a message using sqlite3_log() containing the current value of

  42717. ** error code and, if possible, the human-readable equivalent from

  42718. ** FormatMessage.

  42719. **

  42720. ** The first argument passed to the macro should be the error code that

  42721. ** will be returned to SQLite (e.g. SQLITE_IOERR_DELETE, SQLITE_CANTOPEN).

  42722. ** The two subsequent arguments should be the name of the OS function that

  42723. ** failed and the associated file-system path, if any.

  42724. */

  42725. #define winLogError(a,b,c,d)   winLogErrorAtLine(a,b,c,d,__LINE__)

  42726. static int winLogErrorAtLine(

  42727.   int errcode,                    /* SQLite error code */

  42728.   DWORD lastErrno,                /* Win32 last error */

  42729.   const char *zFunc,              /* Name of OS function that failed */

  42730.   const char *zPath,              /* File path associated with error */

  42731.   int iLine                       /* Source line number where error occurred */

  42732. ){

  42733.   char zMsg[500];                 /* Human readable error text */

  42734.   int i;                          /* Loop counter */

  42735. 

  42736.   zMsg[0] = 0;

  42737.   winGetLastErrorMsg(lastErrno, sizeof(zMsg), zMsg);

  42738.   assert( errcode!=SQLITE_OK );

  42739.   if( zPath==0 ) zPath = "";

  42740.   for(i=0; zMsg[i] && zMsg[i]!='\r' && zMsg[i]!='\n'; i++){}

  42741.   zMsg[i] = 0;

  42742.   sqlite3_log(errcode,

  42743.       "os_win.c:%d: (%lu) %s(%s) - %s",

  42744.       iLine, lastErrno, zFunc, zPath, zMsg

  42745.   );

  42746. 

  42747.   return errcode;

  42748. }

  42749. 

  42750. /*

  42751. ** The number of times that a ReadFile(), WriteFile(), and DeleteFile()

  42752. ** will be retried following a locking error - probably caused by

  42753. ** antivirus software.  Also the initial delay before the first retry.

  42754. ** The delay increases linearly with each retry.

  42755. */

  42756. #ifndef SQLITE_WIN32_IOERR_RETRY

  42757. # define SQLITE_WIN32_IOERR_RETRY 10

  42758. #endif

  42759. #ifndef SQLITE_WIN32_IOERR_RETRY_DELAY

  42760. # define SQLITE_WIN32_IOERR_RETRY_DELAY 25

  42761. #endif

  42762. static int winIoerrRetry = SQLITE_WIN32_IOERR_RETRY;

  42763. static int winIoerrRetryDelay = SQLITE_WIN32_IOERR_RETRY_DELAY;

  42764. 

  42765. /*

  42766. ** The "winIoerrCanRetry1" macro is used to determine if a particular I/O

  42767. ** error code obtained via GetLastError() is eligible to be retried.  It

  42768. ** must accept the error code DWORD as its only argument and should return

  42769. ** non-zero if the error code is transient in nature and the operation

  42770. ** responsible for generating the original error might succeed upon being

  42771. ** retried.  The argument to this macro should be a variable.

  42772. **

  42773. ** Additionally, a macro named "winIoerrCanRetry2" may be defined.  If it

  42774. ** is defined, it will be consulted only when the macro "winIoerrCanRetry1"

  42775. ** returns zero.  The "winIoerrCanRetry2" macro is completely optional and

  42776. ** may be used to include additional error codes in the set that should

  42777. ** result in the failing I/O operation being retried by the caller.  If

  42778. ** defined, the "winIoerrCanRetry2" macro must exhibit external semantics

  42779. ** identical to those of the "winIoerrCanRetry1" macro.

  42780. */

  42781. #if !defined(winIoerrCanRetry1)

  42782. #define winIoerrCanRetry1(a) (((a)==ERROR_ACCESS_DENIED)        || \

  42783.                               ((a)==ERROR_SHARING_VIOLATION)    || \

  42784.                               ((a)==ERROR_LOCK_VIOLATION)       || \

  42785.                               ((a)==ERROR_DEV_NOT_EXIST)        || \

  42786.                               ((a)==ERROR_NETNAME_DELETED)      || \

  42787.                               ((a)==ERROR_SEM_TIMEOUT)          || \

  42788.                               ((a)==ERROR_NETWORK_UNREACHABLE))

  42789. #endif

  42790. 

  42791. /*

  42792. ** If a ReadFile() or WriteFile() error occurs, invoke this routine

  42793. ** to see if it should be retried.  Return TRUE to retry.  Return FALSE

  42794. ** to give up with an error.

  42795. */

  42796. static int winRetryIoerr(int *pnRetry, DWORD *pError){

  42797.   DWORD e = osGetLastError();

  42798.   if( *pnRetry>=winIoerrRetry ){

  42799.     if( pError ){

  42800.       *pError = e;

  42801.     }

  42802.     return 0;

  42803.   }

  42804.   if( winIoerrCanRetry1(e) ){

  42805.     sqlite3_win32_sleep(winIoerrRetryDelay*(1+*pnRetry));

  42806.     ++*pnRetry;

  42807.     return 1;

  42808.   }

  42809. #if defined(winIoerrCanRetry2)

  42810.   else if( winIoerrCanRetry2(e) ){

  42811.     sqlite3_win32_sleep(winIoerrRetryDelay*(1+*pnRetry));

  42812.     ++*pnRetry;

  42813.     return 1;

  42814.   }

  42815. #endif

  42816.   if( pError ){

  42817.     *pError = e;

  42818.   }

  42819.   return 0;

  42820. }

  42821. 

  42822. /*

  42823. ** Log a I/O error retry episode.

  42824. */

  42825. static void winLogIoerr(int nRetry, int lineno){

  42826.   if( nRetry ){

  42827.     sqlite3_log(SQLITE_NOTICE,

  42828.       "delayed %dms for lock/sharing conflict at line %d",

  42829.       winIoerrRetryDelay*nRetry*(nRetry+1)/2, lineno

  42830.     );

  42831.   }

  42832. }

  42833. 

  42834. /*

  42835. ** This #if does not rely on the SQLITE_OS_WINCE define because the

  42836. ** corresponding section in "date.c" cannot use it.

  42837. */

  42838. #if !defined(SQLITE_OMIT_LOCALTIME) && defined(_WIN32_WCE) && \

  42839.     (!defined(SQLITE_MSVC_LOCALTIME_API) || !SQLITE_MSVC_LOCALTIME_API)

  42840. /*

  42841. ** The MSVC CRT on Windows CE may not have a localtime() function.

  42842. ** So define a substitute.

  42843. */

  42844. /* #  include <time.h> */

  42845. struct tm *__cdecl localtime(const time_t *t)

  42846. {

  42847.   static struct tm y;

  42848.   FILETIME uTm, lTm;

  42849.   SYSTEMTIME pTm;

  42850.   sqlite3_int64 t64;

  42851.   t64 = *t;

  42852.   t64 = (t64 + 11644473600)*10000000;

  42853.   uTm.dwLowDateTime = (DWORD)(t64 & 0xFFFFFFFF);

  42854.   uTm.dwHighDateTime= (DWORD)(t64 >> 32);

  42855.   osFileTimeToLocalFileTime(&uTm,&lTm);

  42856.   osFileTimeToSystemTime(&lTm,&pTm);

  42857.   y.tm_year = pTm.wYear - 1900;

  42858.   y.tm_mon = pTm.wMonth - 1;

  42859.   y.tm_wday = pTm.wDayOfWeek;

  42860.   y.tm_mday = pTm.wDay;

  42861.   y.tm_hour = pTm.wHour;

  42862.   y.tm_min = pTm.wMinute;

  42863.   y.tm_sec = pTm.wSecond;

  42864.   return &y;

  42865. }

  42866. #endif

  42867. 

  42868. #if SQLITE_OS_WINCE

  42869. /*************************************************************************

  42870. ** This section contains code for WinCE only.

  42871. */

  42872. #define HANDLE_TO_WINFILE(a) (winFile*)&((char*)a)[-(int)offsetof(winFile,h)]

  42873. 

  42874. /*

  42875. ** Acquire a lock on the handle h

  42876. */

  42877. static void winceMutexAcquire(HANDLE h){

  42878.    DWORD dwErr;

  42879.    do {

  42880.      dwErr = osWaitForSingleObject(h, INFINITE);

  42881.    } while (dwErr != WAIT_OBJECT_0 && dwErr != WAIT_ABANDONED);

  42882. }

  42883. /*

  42884. ** Release a lock acquired by winceMutexAcquire()

  42885. */

  42886. #define winceMutexRelease(h) ReleaseMutex(h)

  42887. 

  42888. /*

  42889. ** Create the mutex and shared memory used for locking in the file

  42890. ** descriptor pFile

  42891. */

  42892. static int winceCreateLock(const char *zFilename, winFile *pFile){

  42893.   LPWSTR zTok;

  42894.   LPWSTR zName;

  42895.   DWORD lastErrno;

  42896.   BOOL bLogged = FALSE;

  42897.   BOOL bInit = TRUE;

  42898. 

  42899.   zName = winUtf8ToUnicode(zFilename);

  42900.   if( zName==0 ){

  42901.     /* out of memory */

  42902.     return SQLITE_IOERR_NOMEM_BKPT;

  42903.   }

  42904. 

  42905.   /* Initialize the local lockdata */

  42906.   memset(&pFile->local, 0, sizeof(pFile->local));

  42907. 

  42908.   /* Replace the backslashes from the filename and lowercase it

  42909.   ** to derive a mutex name. */

  42910.   zTok = osCharLowerW(zName);

  42911.   for (;*zTok;zTok++){

  42912.     if (*zTok == '\\') *zTok = '_';

  42913.   }

  42914. 

  42915.   /* Create/open the named mutex */

  42916.   pFile->hMutex = osCreateMutexW(NULL, FALSE, zName);

  42917.   if (!pFile->hMutex){

  42918.     pFile->lastErrno = osGetLastError();

  42919.     sqlite3_free(zName);

  42920.     return winLogError(SQLITE_IOERR, pFile->lastErrno,

  42921.                        "winceCreateLock1", zFilename);

  42922.   }

  42923. 

  42924.   /* Acquire the mutex before continuing */

  42925.   winceMutexAcquire(pFile->hMutex);

  42926. 

  42927.   /* Since the names of named mutexes, semaphores, file mappings etc are

  42928.   ** case-sensitive, take advantage of that by uppercasing the mutex name

  42929.   ** and using that as the shared filemapping name.

  42930.   */

  42931.   osCharUpperW(zName);

  42932.   pFile->hShared = osCreateFileMappingW(INVALID_HANDLE_VALUE, NULL,

  42933.                                         PAGE_READWRITE, 0, sizeof(winceLock),

  42934.                                         zName);

  42935. 

  42936.   /* Set a flag that indicates we're the first to create the memory so it

  42937.   ** must be zero-initialized */

  42938.   lastErrno = osGetLastError();

  42939.   if (lastErrno == ERROR_ALREADY_EXISTS){

  42940.     bInit = FALSE;

  42941.   }

  42942. 

  42943.   sqlite3_free(zName);

  42944. 

  42945.   /* If we succeeded in making the shared memory handle, map it. */

  42946.   if( pFile->hShared ){

  42947.     pFile->shared = (winceLock*)osMapViewOfFile(pFile->hShared,

  42948.              FILE_MAP_READ|FILE_MAP_WRITE, 0, 0, sizeof(winceLock));

  42949.     /* If mapping failed, close the shared memory handle and erase it */

  42950.     if( !pFile->shared ){

  42951.       pFile->lastErrno = osGetLastError();

  42952.       winLogError(SQLITE_IOERR, pFile->lastErrno,

  42953.                   "winceCreateLock2", zFilename);

  42954.       bLogged = TRUE;

  42955.       osCloseHandle(pFile->hShared);

  42956.       pFile->hShared = NULL;

  42957.     }

  42958.   }

  42959. 

  42960.   /* If shared memory could not be created, then close the mutex and fail */

  42961.   if( pFile->hShared==NULL ){

  42962.     if( !bLogged ){

  42963.       pFile->lastErrno = lastErrno;

  42964.       winLogError(SQLITE_IOERR, pFile->lastErrno,

  42965.                   "winceCreateLock3", zFilename);

  42966.       bLogged = TRUE;

  42967.     }

  42968.     winceMutexRelease(pFile->hMutex);

  42969.     osCloseHandle(pFile->hMutex);

  42970.     pFile->hMutex = NULL;

  42971.     return SQLITE_IOERR;

  42972.   }

  42973. 

  42974.   /* Initialize the shared memory if we're supposed to */

  42975.   if( bInit ){

  42976.     memset(pFile->shared, 0, sizeof(winceLock));

  42977.   }

  42978. 

  42979.   winceMutexRelease(pFile->hMutex);

  42980.   return SQLITE_OK;

  42981. }

  42982. 

  42983. /*

  42984. ** Destroy the part of winFile that deals with wince locks

  42985. */

  42986. static void winceDestroyLock(winFile *pFile){

  42987.   if (pFile->hMutex){

  42988.     /* Acquire the mutex */

  42989.     winceMutexAcquire(pFile->hMutex);

  42990. 

  42991.     /* The following blocks should probably assert in debug mode, but they

  42992.        are to cleanup in case any locks remained open */

  42993.     if (pFile->local.nReaders){

  42994.       pFile->shared->nReaders --;

  42995.     }

  42996.     if (pFile->local.bReserved){

  42997.       pFile->shared->bReserved = FALSE;

  42998.     }

  42999.     if (pFile->local.bPending){

  43000.       pFile->shared->bPending = FALSE;

  43001.     }

  43002.     if (pFile->local.bExclusive){

  43003.       pFile->shared->bExclusive = FALSE;

  43004.     }

  43005. 

  43006.     /* De-reference and close our copy of the shared memory handle */

  43007.     osUnmapViewOfFile(pFile->shared);

  43008.     osCloseHandle(pFile->hShared);

  43009. 

  43010.     /* Done with the mutex */

  43011.     winceMutexRelease(pFile->hMutex);

  43012.     osCloseHandle(pFile->hMutex);

  43013.     pFile->hMutex = NULL;

  43014.   }

  43015. }

  43016. 

  43017. /*

  43018. ** An implementation of the LockFile() API of Windows for CE

  43019. */

  43020. static BOOL winceLockFile(

  43021.   LPHANDLE phFile,

  43022.   DWORD dwFileOffsetLow,

  43023.   DWORD dwFileOffsetHigh,

  43024.   DWORD nNumberOfBytesToLockLow,

  43025.   DWORD nNumberOfBytesToLockHigh

  43026. ){

  43027.   winFile *pFile = HANDLE_TO_WINFILE(phFile);

  43028.   BOOL bReturn = FALSE;

  43029. 

  43030.   UNUSED_PARAMETER(dwFileOffsetHigh);

  43031.   UNUSED_PARAMETER(nNumberOfBytesToLockHigh);

  43032. 

  43033.   if (!pFile->hMutex) return TRUE;

  43034.   winceMutexAcquire(pFile->hMutex);

  43035. 

  43036.   /* Wanting an exclusive lock? */

  43037.   if (dwFileOffsetLow == (DWORD)SHARED_FIRST

  43038.        && nNumberOfBytesToLockLow == (DWORD)SHARED_SIZE){

  43039.     if (pFile->shared->nReaders == 0 && pFile->shared->bExclusive == 0){

  43040.        pFile->shared->bExclusive = TRUE;

  43041.        pFile->local.bExclusive = TRUE;

  43042.        bReturn = TRUE;

  43043.     }

  43044.   }

  43045. 

  43046.   /* Want a read-only lock? */

  43047.   else if (dwFileOffsetLow == (DWORD)SHARED_FIRST &&

  43048.            nNumberOfBytesToLockLow == 1){

  43049.     if (pFile->shared->bExclusive == 0){

  43050.       pFile->local.nReaders ++;

  43051.       if (pFile->local.nReaders == 1){

  43052.         pFile->shared->nReaders ++;

  43053.       }

  43054.       bReturn = TRUE;

  43055.     }

  43056.   }

  43057. 

  43058.   /* Want a pending lock? */

  43059.   else if (dwFileOffsetLow == (DWORD)PENDING_BYTE

  43060.            && nNumberOfBytesToLockLow == 1){

  43061.     /* If no pending lock has been acquired, then acquire it */

  43062.     if (pFile->shared->bPending == 0) {

  43063.       pFile->shared->bPending = TRUE;

  43064.       pFile->local.bPending = TRUE;

  43065.       bReturn = TRUE;

  43066.     }

  43067.   }

  43068. 

  43069.   /* Want a reserved lock? */

  43070.   else if (dwFileOffsetLow == (DWORD)RESERVED_BYTE

  43071.            && nNumberOfBytesToLockLow == 1){

  43072.     if (pFile->shared->bReserved == 0) {

  43073.       pFile->shared->bReserved = TRUE;

  43074.       pFile->local.bReserved = TRUE;

  43075.       bReturn = TRUE;

  43076.     }

  43077.   }

  43078. 

  43079.   winceMutexRelease(pFile->hMutex);

  43080.   return bReturn;

  43081. }

  43082. 

  43083. /*

  43084. ** An implementation of the UnlockFile API of Windows for CE

  43085. */

  43086. static BOOL winceUnlockFile(

  43087.   LPHANDLE phFile,

  43088.   DWORD dwFileOffsetLow,

  43089.   DWORD dwFileOffsetHigh,

  43090.   DWORD nNumberOfBytesToUnlockLow,

  43091.   DWORD nNumberOfBytesToUnlockHigh

  43092. ){

  43093.   winFile *pFile = HANDLE_TO_WINFILE(phFile);

  43094.   BOOL bReturn = FALSE;

  43095. 

  43096.   UNUSED_PARAMETER(dwFileOffsetHigh);

  43097.   UNUSED_PARAMETER(nNumberOfBytesToUnlockHigh);

  43098. 

  43099.   if (!pFile->hMutex) return TRUE;

  43100.   winceMutexAcquire(pFile->hMutex);

  43101. 

  43102.   /* Releasing a reader lock or an exclusive lock */

  43103.   if (dwFileOffsetLow == (DWORD)SHARED_FIRST){

  43104.     /* Did we have an exclusive lock? */

  43105.     if (pFile->local.bExclusive){

  43106.       assert(nNumberOfBytesToUnlockLow == (DWORD)SHARED_SIZE);

  43107.       pFile->local.bExclusive = FALSE;

  43108.       pFile->shared->bExclusive = FALSE;

  43109.       bReturn = TRUE;

  43110.     }

  43111. 

  43112.     /* Did we just have a reader lock? */

  43113.     else if (pFile->local.nReaders){

  43114.       assert(nNumberOfBytesToUnlockLow == (DWORD)SHARED_SIZE

  43115.              || nNumberOfBytesToUnlockLow == 1);

  43116.       pFile->local.nReaders --;

  43117.       if (pFile->local.nReaders == 0)

  43118.       {

  43119.         pFile->shared->nReaders --;

  43120.       }

  43121.       bReturn = TRUE;

  43122.     }

  43123.   }

  43124. 

  43125.   /* Releasing a pending lock */

  43126.   else if (dwFileOffsetLow == (DWORD)PENDING_BYTE

  43127.            && nNumberOfBytesToUnlockLow == 1){

  43128.     if (pFile->local.bPending){

  43129.       pFile->local.bPending = FALSE;

  43130.       pFile->shared->bPending = FALSE;

  43131.       bReturn = TRUE;

  43132.     }

  43133.   }

  43134.   /* Releasing a reserved lock */

  43135.   else if (dwFileOffsetLow == (DWORD)RESERVED_BYTE

  43136.            && nNumberOfBytesToUnlockLow == 1){

  43137.     if (pFile->local.bReserved) {

  43138.       pFile->local.bReserved = FALSE;

  43139.       pFile->shared->bReserved = FALSE;

  43140.       bReturn = TRUE;

  43141.     }

  43142.   }

  43143. 

  43144.   winceMutexRelease(pFile->hMutex);

  43145.   return bReturn;

  43146. }

  43147. /*

  43148. ** End of the special code for wince

  43149. *****************************************************************************/

  43150. #endif /* SQLITE_OS_WINCE */

  43151. 

  43152. /*

  43153. ** Lock a file region.

  43154. */

  43155. static BOOL winLockFile(

  43156.   LPHANDLE phFile,

  43157.   DWORD flags,

  43158.   DWORD offsetLow,

  43159.   DWORD offsetHigh,

  43160.   DWORD numBytesLow,

  43161.   DWORD numBytesHigh

  43162. ){

  43163. #if SQLITE_OS_WINCE

  43164.   /*

  43165.   ** NOTE: Windows CE is handled differently here due its lack of the Win32

  43166.   **       API LockFile.

  43167.   */

  43168.   return winceLockFile(phFile, offsetLow, offsetHigh,

  43169.                        numBytesLow, numBytesHigh);

  43170. #else

  43171.   if( osIsNT() ){

  43172.     OVERLAPPED ovlp;

  43173.     memset(&ovlp, 0, sizeof(OVERLAPPED));

  43174.     ovlp.Offset = offsetLow;

  43175.     ovlp.OffsetHigh = offsetHigh;

  43176.     return osLockFileEx(*phFile, flags, 0, numBytesLow, numBytesHigh, &ovlp);

  43177.   }else{

  43178.     return osLockFile(*phFile, offsetLow, offsetHigh, numBytesLow,

  43179.                       numBytesHigh);

  43180.   }

  43181. #endif

  43182. }

  43183. 

  43184. /*

  43185. ** Unlock a file region.

  43186.  */

  43187. static BOOL winUnlockFile(

  43188.   LPHANDLE phFile,

  43189.   DWORD offsetLow,

  43190.   DWORD offsetHigh,

  43191.   DWORD numBytesLow,

  43192.   DWORD numBytesHigh

  43193. ){

  43194. #if SQLITE_OS_WINCE

  43195.   /*

  43196.   ** NOTE: Windows CE is handled differently here due its lack of the Win32

  43197.   **       API UnlockFile.

  43198.   */

  43199.   return winceUnlockFile(phFile, offsetLow, offsetHigh,

  43200.                          numBytesLow, numBytesHigh);

  43201. #else

  43202.   if( osIsNT() ){

  43203.     OVERLAPPED ovlp;

  43204.     memset(&ovlp, 0, sizeof(OVERLAPPED));

  43205.     ovlp.Offset = offsetLow;

  43206.     ovlp.OffsetHigh = offsetHigh;

  43207.     return osUnlockFileEx(*phFile, 0, numBytesLow, numBytesHigh, &ovlp);

  43208.   }else{

  43209.     return osUnlockFile(*phFile, offsetLow, offsetHigh, numBytesLow,

  43210.                         numBytesHigh);

  43211.   }

  43212. #endif

  43213. }

  43214. 

  43215. /*****************************************************************************

  43216. ** The next group of routines implement the I/O methods specified

  43217. ** by the sqlite3_io_methods object.

  43218. ******************************************************************************/

  43219. 

  43220. /*

  43221. ** Some Microsoft compilers lack this definition.

  43222. */

  43223. #ifndef INVALID_SET_FILE_POINTER

  43224. # define INVALID_SET_FILE_POINTER ((DWORD)-1)

  43225. #endif

  43226. 

  43227. /*

  43228. ** Move the current position of the file handle passed as the first

  43229. ** argument to offset iOffset within the file. If successful, return 0.

  43230. ** Otherwise, set pFile->lastErrno and return non-zero.

  43231. */

  43232. static int winSeekFile(winFile *pFile, sqlite3_int64 iOffset){

  43233. #if !SQLITE_OS_WINRT

  43234.   LONG upperBits;                 /* Most sig. 32 bits of new offset */

  43235.   LONG lowerBits;                 /* Least sig. 32 bits of new offset */

  43236.   DWORD dwRet;                    /* Value returned by SetFilePointer() */

  43237.   DWORD lastErrno;                /* Value returned by GetLastError() */

  43238. 

  43239.   OSTRACE(("SEEK file=%p, offset=%lld\n", pFile->h, iOffset));

  43240. 

  43241.   upperBits = (LONG)((iOffset>>32) & 0x7fffffff);

  43242.   lowerBits = (LONG)(iOffset & 0xffffffff);

  43243. 

  43244.   /* API oddity: If successful, SetFilePointer() returns a dword

  43245.   ** containing the lower 32-bits of the new file-offset. Or, if it fails,

  43246.   ** it returns INVALID_SET_FILE_POINTER. However according to MSDN,

  43247.   ** INVALID_SET_FILE_POINTER may also be a valid new offset. So to determine

  43248.   ** whether an error has actually occurred, it is also necessary to call

  43249.   ** GetLastError().

  43250.   */

  43251.   dwRet = osSetFilePointer(pFile->h, lowerBits, &upperBits, FILE_BEGIN);

  43252. 

  43253.   if( (dwRet==INVALID_SET_FILE_POINTER

  43254.       && ((lastErrno = osGetLastError())!=NO_ERROR)) ){

  43255.     pFile->lastErrno = lastErrno;

  43256.     winLogError(SQLITE_IOERR_SEEK, pFile->lastErrno,

  43257.                 "winSeekFile", pFile->zPath);

  43258.     OSTRACE(("SEEK file=%p, rc=SQLITE_IOERR_SEEK\n", pFile->h));

  43259.     return 1;

  43260.   }

  43261. 

  43262.   OSTRACE(("SEEK file=%p, rc=SQLITE_OK\n", pFile->h));

  43263.   return 0;

  43264. #else

  43265.   /*

  43266.   ** Same as above, except that this implementation works for WinRT.

  43267.   */

  43268. 

  43269.   LARGE_INTEGER x;                /* The new offset */

  43270.   BOOL bRet;                      /* Value returned by SetFilePointerEx() */

  43271. 

  43272.   x.QuadPart = iOffset;

  43273.   bRet = osSetFilePointerEx(pFile->h, x, 0, FILE_BEGIN);

  43274. 

  43275.   if(!bRet){

  43276.     pFile->lastErrno = osGetLastError();

  43277.     winLogError(SQLITE_IOERR_SEEK, pFile->lastErrno,

  43278.                 "winSeekFile", pFile->zPath);

  43279.     OSTRACE(("SEEK file=%p, rc=SQLITE_IOERR_SEEK\n", pFile->h));

  43280.     return 1;

  43281.   }

  43282. 

  43283.   OSTRACE(("SEEK file=%p, rc=SQLITE_OK\n", pFile->h));

  43284.   return 0;

  43285. #endif

  43286. }

  43287. 

  43288. #if SQLITE_MAX_MMAP_SIZE>0

  43289. /* Forward references to VFS helper methods used for memory mapped files */

  43290. static int winMapfile(winFile*, sqlite3_int64);

  43291. static int winUnmapfile(winFile*);

  43292. #endif

  43293. 

  43294. /*

  43295. ** Close a file.

  43296. **

  43297. ** It is reported that an attempt to close a handle might sometimes

  43298. ** fail.  This is a very unreasonable result, but Windows is notorious

  43299. ** for being unreasonable so I do not doubt that it might happen.  If

  43300. ** the close fails, we pause for 100 milliseconds and try again.  As

  43301. ** many as MX_CLOSE_ATTEMPT attempts to close the handle are made before

  43302. ** giving up and returning an error.

  43303. */

  43304. #define MX_CLOSE_ATTEMPT 3

  43305. static int winClose(sqlite3_file *id){

  43306.   int rc, cnt = 0;

  43307.   winFile *pFile = (winFile*)id;

  43308. 

  43309.   assert( id!=0 );

  43310. #ifndef SQLITE_OMIT_WAL

  43311.   assert( pFile->pShm==0 );

  43312. #endif

  43313.   assert( pFile->h!=NULL && pFile->h!=INVALID_HANDLE_VALUE );

  43314.   OSTRACE(("CLOSE pid=%lu, pFile=%p, file=%p\n",

  43315.            osGetCurrentProcessId(), pFile, pFile->h));

  43316. 

  43317. #if SQLITE_MAX_MMAP_SIZE>0

  43318.   winUnmapfile(pFile);

  43319. #endif

  43320. 

  43321.   do{

  43322.     rc = osCloseHandle(pFile->h);

  43323.     /* SimulateIOError( rc=0; cnt=MX_CLOSE_ATTEMPT; ); */

  43324.   }while( rc==0 && ++cnt < MX_CLOSE_ATTEMPT && (sqlite3_win32_sleep(100), 1) );

  43325. #if SQLITE_OS_WINCE

  43326. #define WINCE_DELETION_ATTEMPTS 3

  43327.   {

  43328.     winVfsAppData *pAppData = (winVfsAppData*)pFile->pVfs->pAppData;

  43329.     if( pAppData==NULL || !pAppData->bNoLock ){

  43330.       winceDestroyLock(pFile);

  43331.     }

  43332.   }

  43333.   if( pFile->zDeleteOnClose ){

  43334.     int cnt = 0;

  43335.     while(

  43336.            osDeleteFileW(pFile->zDeleteOnClose)==0

  43337.         && osGetFileAttributesW(pFile->zDeleteOnClose)!=0xffffffff

  43338.         && cnt++ < WINCE_DELETION_ATTEMPTS

  43339.     ){

  43340.        sqlite3_win32_sleep(100);  /* Wait a little before trying again */

  43341.     }

  43342.     sqlite3_free(pFile->zDeleteOnClose);

  43343.   }

  43344. #endif

  43345.   if( rc ){

  43346.     pFile->h = NULL;

  43347.   }

  43348.   OpenCounter(-1);

  43349.   OSTRACE(("CLOSE pid=%lu, pFile=%p, file=%p, rc=%s\n",

  43350.            osGetCurrentProcessId(), pFile, pFile->h, rc ? "ok" : "failed"));

  43351.   return rc ? SQLITE_OK

  43352.             : winLogError(SQLITE_IOERR_CLOSE, osGetLastError(),

  43353.                           "winClose", pFile->zPath);

  43354. }

  43355. 

  43356. /*

  43357. ** Read data from a file into a buffer.  Return SQLITE_OK if all

  43358. ** bytes were read successfully and SQLITE_IOERR if anything goes

  43359. ** wrong.

  43360. */

  43361. static int winRead(

  43362.   sqlite3_file *id,          /* File to read from */

  43363.   void *pBuf,                /* Write content into this buffer */

  43364.   int amt,                   /* Number of bytes to read */

  43365.   sqlite3_int64 offset       /* Begin reading at this offset */

  43366. ){

  43367. #if !SQLITE_OS_WINCE && !defined(SQLITE_WIN32_NO_OVERLAPPED)

  43368.   OVERLAPPED overlapped;          /* The offset for ReadFile. */

  43369. #endif

  43370.   winFile *pFile = (winFile*)id;  /* file handle */

  43371.   DWORD nRead;                    /* Number of bytes actually read from file */

  43372.   int nRetry = 0;                 /* Number of retrys */

  43373. 

  43374.   assert( id!=0 );

  43375.   assert( amt>0 );

  43376.   assert( offset>=0 );

  43377.   SimulateIOError(return SQLITE_IOERR_READ);

  43378.   OSTRACE(("READ pid=%lu, pFile=%p, file=%p, buffer=%p, amount=%d, "

  43379.            "offset=%lld, lock=%d\n", osGetCurrentProcessId(), pFile,

  43380.            pFile->h, pBuf, amt, offset, pFile->locktype));

  43381. 

  43382. #if SQLITE_MAX_MMAP_SIZE>0

  43383.   /* Deal with as much of this read request as possible by transfering

  43384.   ** data from the memory mapping using memcpy().  */

  43385.   if( offset<pFile->mmapSize ){

  43386.     if( offset+amt <= pFile->mmapSize ){

  43387.       memcpy(pBuf, &((u8 *)(pFile->pMapRegion))[offset], amt);

  43388.       OSTRACE(("READ-MMAP pid=%lu, pFile=%p, file=%p, rc=SQLITE_OK\n",

  43389.                osGetCurrentProcessId(), pFile, pFile->h));

  43390.       return SQLITE_OK;

  43391.     }else{

  43392.       int nCopy = (int)(pFile->mmapSize - offset);

  43393.       memcpy(pBuf, &((u8 *)(pFile->pMapRegion))[offset], nCopy);

  43394.       pBuf = &((u8 *)pBuf)[nCopy];

  43395.       amt -= nCopy;

  43396.       offset += nCopy;

  43397.     }

  43398.   }

  43399. #endif

  43400. 

  43401. #if SQLITE_OS_WINCE || defined(SQLITE_WIN32_NO_OVERLAPPED)

  43402.   if( winSeekFile(pFile, offset) ){

  43403.     OSTRACE(("READ pid=%lu, pFile=%p, file=%p, rc=SQLITE_FULL\n",

  43404.              osGetCurrentProcessId(), pFile, pFile->h));

  43405.     return SQLITE_FULL;

  43406.   }

  43407.   while( !osReadFile(pFile->h, pBuf, amt, &nRead, 0) ){

  43408. #else

  43409.   memset(&overlapped, 0, sizeof(OVERLAPPED));

  43410.   overlapped.Offset = (LONG)(offset & 0xffffffff);

  43411.   overlapped.OffsetHigh = (LONG)((offset>>32) & 0x7fffffff);

  43412.   while( !osReadFile(pFile->h, pBuf, amt, &nRead, &overlapped) &&

  43413.          osGetLastError()!=ERROR_HANDLE_EOF ){

  43414. #endif

  43415.     DWORD lastErrno;

  43416.     if( winRetryIoerr(&nRetry, &lastErrno) ) continue;

  43417.     pFile->lastErrno = lastErrno;

  43418.     OSTRACE(("READ pid=%lu, pFile=%p, file=%p, rc=SQLITE_IOERR_READ\n",

  43419.              osGetCurrentProcessId(), pFile, pFile->h));

  43420.     return winLogError(SQLITE_IOERR_READ, pFile->lastErrno,

  43421.                        "winRead", pFile->zPath);

  43422.   }

  43423.   winLogIoerr(nRetry, __LINE__);

  43424.   if( nRead<(DWORD)amt ){

  43425.     /* Unread parts of the buffer must be zero-filled */

  43426.     memset(&((char*)pBuf)[nRead], 0, amt-nRead);

  43427.     OSTRACE(("READ pid=%lu, pFile=%p, file=%p, rc=SQLITE_IOERR_SHORT_READ\n",

  43428.              osGetCurrentProcessId(), pFile, pFile->h));

  43429.     return SQLITE_IOERR_SHORT_READ;

  43430.   }

  43431. 

  43432.   OSTRACE(("READ pid=%lu, pFile=%p, file=%p, rc=SQLITE_OK\n",

  43433.            osGetCurrentProcessId(), pFile, pFile->h));

  43434.   return SQLITE_OK;

  43435. }

  43436. 

  43437. /*

  43438. ** Write data from a buffer into a file.  Return SQLITE_OK on success

  43439. ** or some other error code on failure.

  43440. */

  43441. static int winWrite(

  43442.   sqlite3_file *id,               /* File to write into */

  43443.   const void *pBuf,               /* The bytes to be written */

  43444.   int amt,                        /* Number of bytes to write */

  43445.   sqlite3_int64 offset            /* Offset into the file to begin writing at */

  43446. ){

  43447.   int rc = 0;                     /* True if error has occurred, else false */

  43448.   winFile *pFile = (winFile*)id;  /* File handle */

  43449.   int nRetry = 0;                 /* Number of retries */

  43450. 

  43451.   assert( amt>0 );

  43452.   assert( pFile );

  43453.   SimulateIOError(return SQLITE_IOERR_WRITE);

  43454.   SimulateDiskfullError(return SQLITE_FULL);

  43455. 

  43456.   OSTRACE(("WRITE pid=%lu, pFile=%p, file=%p, buffer=%p, amount=%d, "

  43457.            "offset=%lld, lock=%d\n", osGetCurrentProcessId(), pFile,

  43458.            pFile->h, pBuf, amt, offset, pFile->locktype));

  43459. 

  43460. #if defined(SQLITE_MMAP_READWRITE) && SQLITE_MAX_MMAP_SIZE>0

  43461.   /* Deal with as much of this write request as possible by transfering

  43462.   ** data from the memory mapping using memcpy().  */

  43463.   if( offset<pFile->mmapSize ){

  43464.     if( offset+amt <= pFile->mmapSize ){

  43465.       memcpy(&((u8 *)(pFile->pMapRegion))[offset], pBuf, amt);

  43466.       OSTRACE(("WRITE-MMAP pid=%lu, pFile=%p, file=%p, rc=SQLITE_OK\n",

  43467.                osGetCurrentProcessId(), pFile, pFile->h));

  43468.       return SQLITE_OK;

  43469.     }else{

  43470.       int nCopy = (int)(pFile->mmapSize - offset);

  43471.       memcpy(&((u8 *)(pFile->pMapRegion))[offset], pBuf, nCopy);

  43472.       pBuf = &((u8 *)pBuf)[nCopy];

  43473.       amt -= nCopy;

  43474.       offset += nCopy;

  43475.     }

  43476.   }

  43477. #endif

  43478. 

  43479. #if SQLITE_OS_WINCE || defined(SQLITE_WIN32_NO_OVERLAPPED)

  43480.   rc = winSeekFile(pFile, offset);

  43481.   if( rc==0 ){

  43482. #else

  43483.   {

  43484. #endif

  43485. #if !SQLITE_OS_WINCE && !defined(SQLITE_WIN32_NO_OVERLAPPED)

  43486.     OVERLAPPED overlapped;        /* The offset for WriteFile. */

  43487. #endif

  43488.     u8 *aRem = (u8 *)pBuf;        /* Data yet to be written */

  43489.     int nRem = amt;               /* Number of bytes yet to be written */

  43490.     DWORD nWrite;                 /* Bytes written by each WriteFile() call */

  43491.     DWORD lastErrno = NO_ERROR;   /* Value returned by GetLastError() */

  43492. 

  43493. #if !SQLITE_OS_WINCE && !defined(SQLITE_WIN32_NO_OVERLAPPED)

  43494.     memset(&overlapped, 0, sizeof(OVERLAPPED));

  43495.     overlapped.Offset = (LONG)(offset & 0xffffffff);

  43496.     overlapped.OffsetHigh = (LONG)((offset>>32) & 0x7fffffff);

  43497. #endif

  43498. 

  43499.     while( nRem>0 ){

  43500. #if SQLITE_OS_WINCE || defined(SQLITE_WIN32_NO_OVERLAPPED)

  43501.       if( !osWriteFile(pFile->h, aRem, nRem, &nWrite, 0) ){

  43502. #else

  43503.       if( !osWriteFile(pFile->h, aRem, nRem, &nWrite, &overlapped) ){

  43504. #endif

  43505.         if( winRetryIoerr(&nRetry, &lastErrno) ) continue;

  43506.         break;

  43507.       }

  43508.       assert( nWrite==0 || nWrite<=(DWORD)nRem );

  43509.       if( nWrite==0 || nWrite>(DWORD)nRem ){

  43510.         lastErrno = osGetLastError();

  43511.         break;

  43512.       }

  43513. #if !SQLITE_OS_WINCE && !defined(SQLITE_WIN32_NO_OVERLAPPED)

  43514.       offset += nWrite;

  43515.       overlapped.Offset = (LONG)(offset & 0xffffffff);

  43516.       overlapped.OffsetHigh = (LONG)((offset>>32) & 0x7fffffff);

  43517. #endif

  43518.       aRem += nWrite;

  43519.       nRem -= nWrite;

  43520.     }

  43521.     if( nRem>0 ){

  43522.       pFile->lastErrno = lastErrno;

  43523.       rc = 1;

  43524.     }

  43525.   }

  43526. 

  43527.   if( rc ){

  43528.     if(   ( pFile->lastErrno==ERROR_HANDLE_DISK_FULL )

  43529.        || ( pFile->lastErrno==ERROR_DISK_FULL )){

  43530.       OSTRACE(("WRITE pid=%lu, pFile=%p, file=%p, rc=SQLITE_FULL\n",

  43531.                osGetCurrentProcessId(), pFile, pFile->h));

  43532.       return winLogError(SQLITE_FULL, pFile->lastErrno,

  43533.                          "winWrite1", pFile->zPath);

  43534.     }

  43535.     OSTRACE(("WRITE pid=%lu, pFile=%p, file=%p, rc=SQLITE_IOERR_WRITE\n",

  43536.              osGetCurrentProcessId(), pFile, pFile->h));

  43537.     return winLogError(SQLITE_IOERR_WRITE, pFile->lastErrno,

  43538.                        "winWrite2", pFile->zPath);

  43539.   }else{

  43540.     winLogIoerr(nRetry, __LINE__);

  43541.   }

  43542.   OSTRACE(("WRITE pid=%lu, pFile=%p, file=%p, rc=SQLITE_OK\n",

  43543.            osGetCurrentProcessId(), pFile, pFile->h));

  43544.   return SQLITE_OK;

  43545. }

  43546. 

  43547. /*

  43548. ** Truncate an open file to a specified size

  43549. */

  43550. static int winTruncate(sqlite3_file *id, sqlite3_int64 nByte){

  43551.   winFile *pFile = (winFile*)id;  /* File handle object */

  43552.   int rc = SQLITE_OK;             /* Return code for this function */

  43553.   DWORD lastErrno;

  43554. #if SQLITE_MAX_MMAP_SIZE>0

  43555.   sqlite3_int64 oldMmapSize;

  43556.   if( pFile->nFetchOut>0 ){

  43557.     /* File truncation is a no-op if there are outstanding memory mapped

  43558.     ** pages.  This is because truncating the file means temporarily unmapping

  43559.     ** the file, and that might delete memory out from under existing cursors.

  43560.     **

  43561.     ** This can result in incremental vacuum not truncating the file,

  43562.     ** if there is an active read cursor when the incremental vacuum occurs.

  43563.     ** No real harm comes of this - the database file is not corrupted,

  43564.     ** though some folks might complain that the file is bigger than it

  43565.     ** needs to be.

  43566.     **

  43567.     ** The only feasible work-around is to defer the truncation until after

  43568.     ** all references to memory-mapped content are closed.  That is doable,

  43569.     ** but involves adding a few branches in the common write code path which

  43570.     ** could slow down normal operations slightly.  Hence, we have decided for

  43571.     ** now to simply make trancations a no-op if there are pending reads.  We

  43572.     ** can maybe revisit this decision in the future.

  43573.     */

  43574.     return SQLITE_OK;

  43575.   }

  43576. #endif

  43577. 

  43578.   assert( pFile );

  43579.   SimulateIOError(return SQLITE_IOERR_TRUNCATE);

  43580.   OSTRACE(("TRUNCATE pid=%lu, pFile=%p, file=%p, size=%lld, lock=%d\n",

  43581.            osGetCurrentProcessId(), pFile, pFile->h, nByte, pFile->locktype));

  43582. 

  43583.   /* If the user has configured a chunk-size for this file, truncate the

  43584.   ** file so that it consists of an integer number of chunks (i.e. the

  43585.   ** actual file size after the operation may be larger than the requested

  43586.   ** size).

  43587.   */

  43588.   if( pFile->szChunk>0 ){

  43589.     nByte = ((nByte + pFile->szChunk - 1)/pFile->szChunk) * pFile->szChunk;

  43590.   }

  43591. 

  43592. #if SQLITE_MAX_MMAP_SIZE>0

  43593.   if( pFile->pMapRegion ){

  43594.     oldMmapSize = pFile->mmapSize;

  43595.   }else{

  43596.     oldMmapSize = 0;

  43597.   }

  43598.   winUnmapfile(pFile);

  43599. #endif

  43600. 

  43601.   /* SetEndOfFile() returns non-zero when successful, or zero when it fails. */

  43602.   if( winSeekFile(pFile, nByte) ){

  43603.     rc = winLogError(SQLITE_IOERR_TRUNCATE, pFile->lastErrno,

  43604.                      "winTruncate1", pFile->zPath);

  43605.   }else if( 0==osSetEndOfFile(pFile->h) &&

  43606.             ((lastErrno = osGetLastError())!=ERROR_USER_MAPPED_FILE) ){

  43607.     pFile->lastErrno = lastErrno;

  43608.     rc = winLogError(SQLITE_IOERR_TRUNCATE, pFile->lastErrno,

  43609.                      "winTruncate2", pFile->zPath);

  43610.   }

  43611. 

  43612. #if SQLITE_MAX_MMAP_SIZE>0

  43613.   if( rc==SQLITE_OK && oldMmapSize>0 ){

  43614.     if( oldMmapSize>nByte ){

  43615.       winMapfile(pFile, -1);

  43616.     }else{

  43617.       winMapfile(pFile, oldMmapSize);

  43618.     }

  43619.   }

  43620. #endif

  43621. 

  43622.   OSTRACE(("TRUNCATE pid=%lu, pFile=%p, file=%p, rc=%s\n",

  43623.            osGetCurrentProcessId(), pFile, pFile->h, sqlite3ErrName(rc)));

  43624.   return rc;

  43625. }

  43626. 

  43627. #ifdef SQLITE_TEST

  43628. /*

  43629. ** Count the number of fullsyncs and normal syncs.  This is used to test

  43630. ** that syncs and fullsyncs are occuring at the right times.

  43631. */

  43632. SQLITE_API int sqlite3_sync_count = 0;

  43633. SQLITE_API int sqlite3_fullsync_count = 0;

  43634. #endif

  43635. 

  43636. /*

  43637. ** Make sure all writes to a particular file are committed to disk.

  43638. */

  43639. static int winSync(sqlite3_file *id, int flags){

  43640. #ifndef SQLITE_NO_SYNC

  43641.   /*

  43642.   ** Used only when SQLITE_NO_SYNC is not defined.

  43643.    */

  43644.   BOOL rc;

  43645. #endif

  43646. #if !defined(NDEBUG) || !defined(SQLITE_NO_SYNC) || \

  43647.     defined(SQLITE_HAVE_OS_TRACE)

  43648.   /*

  43649.   ** Used when SQLITE_NO_SYNC is not defined and by the assert() and/or

  43650.   ** OSTRACE() macros.

  43651.    */

  43652.   winFile *pFile = (winFile*)id;

  43653. #else

  43654.   UNUSED_PARAMETER(id);

  43655. #endif

  43656. 

  43657.   assert( pFile );

  43658.   /* Check that one of SQLITE_SYNC_NORMAL or FULL was passed */

  43659.   assert((flags&0x0F)==SQLITE_SYNC_NORMAL

  43660.       || (flags&0x0F)==SQLITE_SYNC_FULL

  43661.   );

  43662. 

  43663.   /* Unix cannot, but some systems may return SQLITE_FULL from here. This

  43664.   ** line is to test that doing so does not cause any problems.

  43665.   */

  43666.   SimulateDiskfullError( return SQLITE_FULL );

  43667. 

  43668.   OSTRACE(("SYNC pid=%lu, pFile=%p, file=%p, flags=%x, lock=%d\n",

  43669.            osGetCurrentProcessId(), pFile, pFile->h, flags,

  43670.            pFile->locktype));

  43671. 

  43672. #ifndef SQLITE_TEST

  43673.   UNUSED_PARAMETER(flags);

  43674. #else

  43675.   if( (flags&0x0F)==SQLITE_SYNC_FULL ){

  43676.     sqlite3_fullsync_count++;

  43677.   }

  43678.   sqlite3_sync_count++;

  43679. #endif

  43680. 

  43681.   /* If we compiled with the SQLITE_NO_SYNC flag, then syncing is a

  43682.   ** no-op

  43683.   */

  43684. #ifdef SQLITE_NO_SYNC

  43685.   OSTRACE(("SYNC-NOP pid=%lu, pFile=%p, file=%p, rc=SQLITE_OK\n",

  43686.            osGetCurrentProcessId(), pFile, pFile->h));

  43687.   return SQLITE_OK;

  43688. #else

  43689. #if SQLITE_MAX_MMAP_SIZE>0

  43690.   if( pFile->pMapRegion ){

  43691.     if( osFlushViewOfFile(pFile->pMapRegion, 0) ){

  43692.       OSTRACE(("SYNC-MMAP pid=%lu, pFile=%p, pMapRegion=%p, "

  43693.                "rc=SQLITE_OK\n", osGetCurrentProcessId(),

  43694.                pFile, pFile->pMapRegion));

  43695.     }else{

  43696.       pFile->lastErrno = osGetLastError();

  43697.       OSTRACE(("SYNC-MMAP pid=%lu, pFile=%p, pMapRegion=%p, "

  43698.                "rc=SQLITE_IOERR_MMAP\n", osGetCurrentProcessId(),

  43699.                pFile, pFile->pMapRegion));

  43700.       return winLogError(SQLITE_IOERR_MMAP, pFile->lastErrno,

  43701.                          "winSync1", pFile->zPath);

  43702.     }

  43703.   }

  43704. #endif

  43705.   rc = osFlushFileBuffers(pFile->h);

  43706.   SimulateIOError( rc=FALSE );

  43707.   if( rc ){

  43708.     OSTRACE(("SYNC pid=%lu, pFile=%p, file=%p, rc=SQLITE_OK\n",

  43709.              osGetCurrentProcessId(), pFile, pFile->h));

  43710.     return SQLITE_OK;

  43711.   }else{

  43712.     pFile->lastErrno = osGetLastError();

  43713.     OSTRACE(("SYNC pid=%lu, pFile=%p, file=%p, rc=SQLITE_IOERR_FSYNC\n",

  43714.              osGetCurrentProcessId(), pFile, pFile->h));

  43715.     return winLogError(SQLITE_IOERR_FSYNC, pFile->lastErrno,

  43716.                        "winSync2", pFile->zPath);

  43717.   }

  43718. #endif

  43719. }

  43720. 

  43721. /*

  43722. ** Determine the current size of a file in bytes

  43723. */

  43724. static int winFileSize(sqlite3_file *id, sqlite3_int64 *pSize){

  43725.   winFile *pFile = (winFile*)id;

  43726.   int rc = SQLITE_OK;

  43727. 

  43728.   assert( id!=0 );

  43729.   assert( pSize!=0 );

  43730.   SimulateIOError(return SQLITE_IOERR_FSTAT);

  43731.   OSTRACE(("SIZE file=%p, pSize=%p\n", pFile->h, pSize));

  43732. 

  43733. #if SQLITE_OS_WINRT

  43734.   {

  43735.     FILE_STANDARD_INFO info;

  43736.     if( osGetFileInformationByHandleEx(pFile->h, FileStandardInfo,

  43737.                                      &info, sizeof(info)) ){

  43738.       *pSize = info.EndOfFile.QuadPart;

  43739.     }else{

  43740.       pFile->lastErrno = osGetLastError();

  43741.       rc = winLogError(SQLITE_IOERR_FSTAT, pFile->lastErrno,

  43742.                        "winFileSize", pFile->zPath);

  43743.     }

  43744.   }

  43745. #else

  43746.   {

  43747.     DWORD upperBits;

  43748.     DWORD lowerBits;

  43749.     DWORD lastErrno;

  43750. 

  43751.     lowerBits = osGetFileSize(pFile->h, &upperBits);

  43752.     *pSize = (((sqlite3_int64)upperBits)<<32) + lowerBits;

  43753.     if(   (lowerBits == INVALID_FILE_SIZE)

  43754.        && ((lastErrno = osGetLastError())!=NO_ERROR) ){

  43755.       pFile->lastErrno = lastErrno;

  43756.       rc = winLogError(SQLITE_IOERR_FSTAT, pFile->lastErrno,

  43757.                        "winFileSize", pFile->zPath);

  43758.     }

  43759.   }

  43760. #endif

  43761.   OSTRACE(("SIZE file=%p, pSize=%p, *pSize=%lld, rc=%s\n",

  43762.            pFile->h, pSize, *pSize, sqlite3ErrName(rc)));

  43763.   return rc;

  43764. }

  43765. 

  43766. /*

  43767. ** LOCKFILE_FAIL_IMMEDIATELY is undefined on some Windows systems.

  43768. */

  43769. #ifndef LOCKFILE_FAIL_IMMEDIATELY

  43770. # define LOCKFILE_FAIL_IMMEDIATELY 1

  43771. #endif

  43772. 

  43773. #ifndef LOCKFILE_EXCLUSIVE_LOCK

  43774. # define LOCKFILE_EXCLUSIVE_LOCK 2

  43775. #endif

  43776. 

  43777. /*

  43778. ** Historically, SQLite has used both the LockFile and LockFileEx functions.

  43779. ** When the LockFile function was used, it was always expected to fail

  43780. ** immediately if the lock could not be obtained.  Also, it always expected to

  43781. ** obtain an exclusive lock.  These flags are used with the LockFileEx function

  43782. ** and reflect those expectations; therefore, they should not be changed.

  43783. */

  43784. #ifndef SQLITE_LOCKFILE_FLAGS

  43785. # define SQLITE_LOCKFILE_FLAGS   (LOCKFILE_FAIL_IMMEDIATELY | \

  43786.                                   LOCKFILE_EXCLUSIVE_LOCK)

  43787. #endif

  43788. 

  43789. /*

  43790. ** Currently, SQLite never calls the LockFileEx function without wanting the

  43791. ** call to fail immediately if the lock cannot be obtained.

  43792. */

  43793. #ifndef SQLITE_LOCKFILEEX_FLAGS

  43794. # define SQLITE_LOCKFILEEX_FLAGS (LOCKFILE_FAIL_IMMEDIATELY)

  43795. #endif

  43796. 

  43797. /*

  43798. ** Acquire a reader lock.

  43799. ** Different API routines are called depending on whether or not this

  43800. ** is Win9x or WinNT.

  43801. */

  43802. static int winGetReadLock(winFile *pFile){

  43803.   int res;

  43804.   OSTRACE(("READ-LOCK file=%p, lock=%d\n", pFile->h, pFile->locktype));

  43805.   if( osIsNT() ){

  43806. #if SQLITE_OS_WINCE

  43807.     /*

  43808.     ** NOTE: Windows CE is handled differently here due its lack of the Win32

  43809.     **       API LockFileEx.

  43810.     */

  43811.     res = winceLockFile(&pFile->h, SHARED_FIRST, 0, 1, 0);

  43812. #else

  43813.     res = winLockFile(&pFile->h, SQLITE_LOCKFILEEX_FLAGS, SHARED_FIRST, 0,

  43814.                       SHARED_SIZE, 0);

  43815. #endif

  43816.   }

  43817. #ifdef SQLITE_WIN32_HAS_ANSI

  43818.   else{

  43819.     int lk;

  43820.     sqlite3_randomness(sizeof(lk), &lk);

  43821.     pFile->sharedLockByte = (short)((lk & 0x7fffffff)%(SHARED_SIZE - 1));

  43822.     res = winLockFile(&pFile->h, SQLITE_LOCKFILE_FLAGS,

  43823.                       SHARED_FIRST+pFile->sharedLockByte, 0, 1, 0);

  43824.   }

  43825. #endif

  43826.   if( res == 0 ){

  43827.     pFile->lastErrno = osGetLastError();

  43828.     /* No need to log a failure to lock */

  43829.   }

  43830.   OSTRACE(("READ-LOCK file=%p, result=%d\n", pFile->h, res));

  43831.   return res;

  43832. }

  43833. 

  43834. /*

  43835. ** Undo a readlock

  43836. */

  43837. static int winUnlockReadLock(winFile *pFile){

  43838.   int res;

  43839.   DWORD lastErrno;

  43840.   OSTRACE(("READ-UNLOCK file=%p, lock=%d\n", pFile->h, pFile->locktype));

  43841.   if( osIsNT() ){

  43842.     res = winUnlockFile(&pFile->h, SHARED_FIRST, 0, SHARED_SIZE, 0);

  43843.   }

  43844. #ifdef SQLITE_WIN32_HAS_ANSI

  43845.   else{

  43846.     res = winUnlockFile(&pFile->h, SHARED_FIRST+pFile->sharedLockByte, 0, 1, 0);

  43847.   }

  43848. #endif

  43849.   if( res==0 && ((lastErrno = osGetLastError())!=ERROR_NOT_LOCKED) ){

  43850.     pFile->lastErrno = lastErrno;

  43851.     winLogError(SQLITE_IOERR_UNLOCK, pFile->lastErrno,

  43852.                 "winUnlockReadLock", pFile->zPath);

  43853.   }

  43854.   OSTRACE(("READ-UNLOCK file=%p, result=%d\n", pFile->h, res));

  43855.   return res;

  43856. }

  43857. 

  43858. /*

  43859. ** Lock the file with the lock specified by parameter locktype - one

  43860. ** of the following:

  43861. **

  43862. **     (1) SHARED_LOCK

  43863. **     (2) RESERVED_LOCK

  43864. **     (3) PENDING_LOCK

  43865. **     (4) EXCLUSIVE_LOCK

  43866. **

  43867. ** Sometimes when requesting one lock state, additional lock states

  43868. ** are inserted in between.  The locking might fail on one of the later

  43869. ** transitions leaving the lock state different from what it started but

  43870. ** still short of its goal.  The following chart shows the allowed

  43871. ** transitions and the inserted intermediate states:

  43872. **

  43873. **    UNLOCKED -> SHARED

  43874. **    SHARED -> RESERVED

  43875. **    SHARED -> (PENDING) -> EXCLUSIVE

  43876. **    RESERVED -> (PENDING) -> EXCLUSIVE

  43877. **    PENDING -> EXCLUSIVE

  43878. **

  43879. ** This routine will only increase a lock.  The winUnlock() routine

  43880. ** erases all locks at once and returns us immediately to locking level 0.

  43881. ** It is not possible to lower the locking level one step at a time.  You

  43882. ** must go straight to locking level 0.

  43883. */

  43884. static int winLock(sqlite3_file *id, int locktype){

  43885.   int rc = SQLITE_OK;    /* Return code from subroutines */

  43886.   int res = 1;           /* Result of a Windows lock call */

  43887.   int newLocktype;       /* Set pFile->locktype to this value before exiting */

  43888.   int gotPendingLock = 0;/* True if we acquired a PENDING lock this time */

  43889.   winFile *pFile = (winFile*)id;

  43890.   DWORD lastErrno = NO_ERROR;

  43891. 

  43892.   assert( id!=0 );

  43893.   OSTRACE(("LOCK file=%p, oldLock=%d(%d), newLock=%d\n",

  43894.            pFile->h, pFile->locktype, pFile->sharedLockByte, locktype));

  43895. 

  43896.   /* If there is already a lock of this type or more restrictive on the

  43897.   ** OsFile, do nothing. Don't use the end_lock: exit path, as

  43898.   ** sqlite3OsEnterMutex() hasn't been called yet.

  43899.   */

  43900.   if( pFile->locktype>=locktype ){

  43901.     OSTRACE(("LOCK-HELD file=%p, rc=SQLITE_OK\n", pFile->h));

  43902.     return SQLITE_OK;

  43903.   }

  43904. 

  43905.   /* Do not allow any kind of write-lock on a read-only database

  43906.   */

  43907.   if( (pFile->ctrlFlags & WINFILE_RDONLY)!=0 && locktype>=RESERVED_LOCK ){

  43908.     return SQLITE_IOERR_LOCK;

  43909.   }

  43910. 

  43911.   /* Make sure the locking sequence is correct

  43912.   */

  43913.   assert( pFile->locktype!=NO_LOCK || locktype==SHARED_LOCK );

  43914.   assert( locktype!=PENDING_LOCK );

  43915.   assert( locktype!=RESERVED_LOCK || pFile->locktype==SHARED_LOCK );

  43916. 

  43917.   /* Lock the PENDING_LOCK byte if we need to acquire a PENDING lock or

  43918.   ** a SHARED lock.  If we are acquiring a SHARED lock, the acquisition of

  43919.   ** the PENDING_LOCK byte is temporary.

  43920.   */

  43921.   newLocktype = pFile->locktype;

  43922.   if( pFile->locktype==NO_LOCK

  43923.    || (locktype==EXCLUSIVE_LOCK && pFile->locktype<=RESERVED_LOCK)

  43924.   ){

  43925.     int cnt = 3;

  43926.     while( cnt-->0 && (res = winLockFile(&pFile->h, SQLITE_LOCKFILE_FLAGS,

  43927.                                          PENDING_BYTE, 0, 1, 0))==0 ){

  43928.       /* Try 3 times to get the pending lock.  This is needed to work

  43929.       ** around problems caused by indexing and/or anti-virus software on

  43930.       ** Windows systems.

  43931.       ** If you are using this code as a model for alternative VFSes, do not

  43932.       ** copy this retry logic.  It is a hack intended for Windows only.

  43933.       */

  43934.       lastErrno = osGetLastError();

  43935.       OSTRACE(("LOCK-PENDING-FAIL file=%p, count=%d, result=%d\n",

  43936.                pFile->h, cnt, res));

  43937.       if( lastErrno==ERROR_INVALID_HANDLE ){

  43938.         pFile->lastErrno = lastErrno;

  43939.         rc = SQLITE_IOERR_LOCK;

  43940.         OSTRACE(("LOCK-FAIL file=%p, count=%d, rc=%s\n",

  43941.                  pFile->h, cnt, sqlite3ErrName(rc)));

  43942.         return rc;

  43943.       }

  43944.       if( cnt ) sqlite3_win32_sleep(1);

  43945.     }

  43946.     gotPendingLock = res;

  43947.     if( !res ){

  43948.       lastErrno = osGetLastError();

  43949.     }

  43950.   }

  43951. 

  43952.   /* Acquire a shared lock

  43953.   */

  43954.   if( locktype==SHARED_LOCK && res ){

  43955.     assert( pFile->locktype==NO_LOCK );

  43956.     res = winGetReadLock(pFile);

  43957.     if( res ){

  43958.       newLocktype = SHARED_LOCK;

  43959.     }else{

  43960.       lastErrno = osGetLastError();

  43961.     }

  43962.   }

  43963. 

  43964.   /* Acquire a RESERVED lock

  43965.   */

  43966.   if( locktype==RESERVED_LOCK && res ){

  43967.     assert( pFile->locktype==SHARED_LOCK );

  43968.     res = winLockFile(&pFile->h, SQLITE_LOCKFILE_FLAGS, RESERVED_BYTE, 0, 1, 0);

  43969.     if( res ){

  43970.       newLocktype = RESERVED_LOCK;

  43971.     }else{

  43972.       lastErrno = osGetLastError();

  43973.     }

  43974.   }

  43975. 

  43976.   /* Acquire a PENDING lock

  43977.   */

  43978.   if( locktype==EXCLUSIVE_LOCK && res ){

  43979.     newLocktype = PENDING_LOCK;

  43980.     gotPendingLock = 0;

  43981.   }

  43982. 

  43983.   /* Acquire an EXCLUSIVE lock

  43984.   */

  43985.   if( locktype==EXCLUSIVE_LOCK && res ){

  43986.     assert( pFile->locktype>=SHARED_LOCK );

  43987.     res = winUnlockReadLock(pFile);

  43988.     res = winLockFile(&pFile->h, SQLITE_LOCKFILE_FLAGS, SHARED_FIRST, 0,

  43989.                       SHARED_SIZE, 0);

  43990.     if( res ){

  43991.       newLocktype = EXCLUSIVE_LOCK;

  43992.     }else{

  43993.       lastErrno = osGetLastError();

  43994.       winGetReadLock(pFile);

  43995.     }

  43996.   }

  43997. 

  43998.   /* If we are holding a PENDING lock that ought to be released, then

  43999.   ** release it now.

  44000.   */

  44001.   if( gotPendingLock && locktype==SHARED_LOCK ){

  44002.     winUnlockFile(&pFile->h, PENDING_BYTE, 0, 1, 0);

  44003.   }

  44004. 

  44005.   /* Update the state of the lock has held in the file descriptor then

  44006.   ** return the appropriate result code.

  44007.   */

  44008.   if( res ){

  44009.     rc = SQLITE_OK;

  44010.   }else{

  44011.     pFile->lastErrno = lastErrno;

  44012.     rc = SQLITE_BUSY;

  44013.     OSTRACE(("LOCK-FAIL file=%p, wanted=%d, got=%d\n",

  44014.              pFile->h, locktype, newLocktype));

  44015.   }

  44016.   pFile->locktype = (u8)newLocktype;

  44017.   OSTRACE(("LOCK file=%p, lock=%d, rc=%s\n",

  44018.            pFile->h, pFile->locktype, sqlite3ErrName(rc)));

  44019.   return rc;

  44020. }

  44021. 

  44022. /*

  44023. ** This routine checks if there is a RESERVED lock held on the specified

  44024. ** file by this or any other process. If such a lock is held, return

  44025. ** non-zero, otherwise zero.

  44026. */

  44027. static int winCheckReservedLock(sqlite3_file *id, int *pResOut){

  44028.   int res;

  44029.   winFile *pFile = (winFile*)id;

  44030. 

  44031.   SimulateIOError( return SQLITE_IOERR_CHECKRESERVEDLOCK; );

  44032.   OSTRACE(("TEST-WR-LOCK file=%p, pResOut=%p\n", pFile->h, pResOut));

  44033. 

  44034.   assert( id!=0 );

  44035.   if( pFile->locktype>=RESERVED_LOCK ){

  44036.     res = 1;

  44037.     OSTRACE(("TEST-WR-LOCK file=%p, result=%d (local)\n", pFile->h, res));

  44038.   }else{

  44039.     res = winLockFile(&pFile->h, SQLITE_LOCKFILEEX_FLAGS,RESERVED_BYTE,0,1,0);

  44040.     if( res ){

  44041.       winUnlockFile(&pFile->h, RESERVED_BYTE, 0, 1, 0);

  44042.     }

  44043.     res = !res;

  44044.     OSTRACE(("TEST-WR-LOCK file=%p, result=%d (remote)\n", pFile->h, res));

  44045.   }

  44046.   *pResOut = res;

  44047.   OSTRACE(("TEST-WR-LOCK file=%p, pResOut=%p, *pResOut=%d, rc=SQLITE_OK\n",

  44048.            pFile->h, pResOut, *pResOut));

  44049.   return SQLITE_OK;

  44050. }

  44051. 

  44052. /*

  44053. ** Lower the locking level on file descriptor id to locktype.  locktype

  44054. ** must be either NO_LOCK or SHARED_LOCK.

  44055. **

  44056. ** If the locking level of the file descriptor is already at or below

  44057. ** the requested locking level, this routine is a no-op.

  44058. **

  44059. ** It is not possible for this routine to fail if the second argument

  44060. ** is NO_LOCK.  If the second argument is SHARED_LOCK then this routine

  44061. ** might return SQLITE_IOERR;

  44062. */

  44063. static int winUnlock(sqlite3_file *id, int locktype){

  44064.   int type;

  44065.   winFile *pFile = (winFile*)id;

  44066.   int rc = SQLITE_OK;

  44067.   assert( pFile!=0 );

  44068.   assert( locktype<=SHARED_LOCK );

  44069.   OSTRACE(("UNLOCK file=%p, oldLock=%d(%d), newLock=%d\n",

  44070.            pFile->h, pFile->locktype, pFile->sharedLockByte, locktype));

  44071.   type = pFile->locktype;

  44072.   if( type>=EXCLUSIVE_LOCK ){

  44073.     winUnlockFile(&pFile->h, SHARED_FIRST, 0, SHARED_SIZE, 0);

  44074.     if( locktype==SHARED_LOCK && !winGetReadLock(pFile) ){

  44075.       /* This should never happen.  We should always be able to

  44076.       ** reacquire the read lock */

  44077.       rc = winLogError(SQLITE_IOERR_UNLOCK, osGetLastError(),

  44078.                        "winUnlock", pFile->zPath);

  44079.     }

  44080.   }

  44081.   if( type>=RESERVED_LOCK ){

  44082.     winUnlockFile(&pFile->h, RESERVED_BYTE, 0, 1, 0);

  44083.   }

  44084.   if( locktype==NO_LOCK && type>=SHARED_LOCK ){

  44085.     winUnlockReadLock(pFile);

  44086.   }

  44087.   if( type>=PENDING_LOCK ){

  44088.     winUnlockFile(&pFile->h, PENDING_BYTE, 0, 1, 0);

  44089.   }

  44090.   pFile->locktype = (u8)locktype;

  44091.   OSTRACE(("UNLOCK file=%p, lock=%d, rc=%s\n",

  44092.            pFile->h, pFile->locktype, sqlite3ErrName(rc)));

  44093.   return rc;

  44094. }

  44095. 

  44096. /******************************************************************************

  44097. ****************************** No-op Locking **********************************

  44098. **

  44099. ** Of the various locking implementations available, this is by far the

  44100. ** simplest:  locking is ignored.  No attempt is made to lock the database

  44101. ** file for reading or writing.

  44102. **

  44103. ** This locking mode is appropriate for use on read-only databases

  44104. ** (ex: databases that are burned into CD-ROM, for example.)  It can

  44105. ** also be used if the application employs some external mechanism to

  44106. ** prevent simultaneous access of the same database by two or more

  44107. ** database connections.  But there is a serious risk of database

  44108. ** corruption if this locking mode is used in situations where multiple

  44109. ** database connections are accessing the same database file at the same

  44110. ** time and one or more of those connections are writing.

  44111. */

  44112. 

  44113. static int winNolockLock(sqlite3_file *id, int locktype){

  44114.   UNUSED_PARAMETER(id);

  44115.   UNUSED_PARAMETER(locktype);

  44116.   return SQLITE_OK;

  44117. }

  44118. 

  44119. static int winNolockCheckReservedLock(sqlite3_file *id, int *pResOut){

  44120.   UNUSED_PARAMETER(id);

  44121.   UNUSED_PARAMETER(pResOut);

  44122.   return SQLITE_OK;

  44123. }

  44124. 

  44125. static int winNolockUnlock(sqlite3_file *id, int locktype){

  44126.   UNUSED_PARAMETER(id);

  44127.   UNUSED_PARAMETER(locktype);

  44128.   return SQLITE_OK;

  44129. }

  44130. 

  44131. /******************* End of the no-op lock implementation *********************

  44132. ******************************************************************************/

  44133. 

  44134. /*

  44135. ** If *pArg is initially negative then this is a query.  Set *pArg to

  44136. ** 1 or 0 depending on whether or not bit mask of pFile->ctrlFlags is set.

  44137. **

  44138. ** If *pArg is 0 or 1, then clear or set the mask bit of pFile->ctrlFlags.

  44139. */

  44140. static void winModeBit(winFile *pFile, unsigned char mask, int *pArg){

  44141.   if( *pArg<0 ){

  44142.     *pArg = (pFile->ctrlFlags & mask)!=0;

  44143.   }else if( (*pArg)==0 ){

  44144.     pFile->ctrlFlags &= ~mask;

  44145.   }else{

  44146.     pFile->ctrlFlags |= mask;

  44147.   }

  44148. }

  44149. 

  44150. /* Forward references to VFS helper methods used for temporary files */

  44151. static int winGetTempname(sqlite3_vfs *, char **);

  44152. static int winIsDir(const void *);

  44153. static BOOL winIsDriveLetterAndColon(const char *);

  44154. 

  44155. /*

  44156. ** Control and query of the open file handle.

  44157. */

  44158. static int winFileControl(sqlite3_file *id, int op, void *pArg){

  44159.   winFile *pFile = (winFile*)id;

  44160.   OSTRACE(("FCNTL file=%p, op=%d, pArg=%p\n", pFile->h, op, pArg));

  44161.   switch( op ){

  44162.     case SQLITE_FCNTL_LOCKSTATE: {

  44163.       *(int*)pArg = pFile->locktype;

  44164.       OSTRACE(("FCNTL file=%p, rc=SQLITE_OK\n", pFile->h));

  44165.       return SQLITE_OK;

  44166.     }

  44167.     case SQLITE_FCNTL_LAST_ERRNO: {

  44168.       *(int*)pArg = (int)pFile->lastErrno;

  44169.       OSTRACE(("FCNTL file=%p, rc=SQLITE_OK\n", pFile->h));

  44170.       return SQLITE_OK;

  44171.     }

  44172.     case SQLITE_FCNTL_CHUNK_SIZE: {

  44173.       pFile->szChunk = *(int *)pArg;

  44174.       OSTRACE(("FCNTL file=%p, rc=SQLITE_OK\n", pFile->h));

  44175.       return SQLITE_OK;

  44176.     }

  44177.     case SQLITE_FCNTL_SIZE_HINT: {

  44178.       if( pFile->szChunk>0 ){

  44179.         sqlite3_int64 oldSz;

  44180.         int rc = winFileSize(id, &oldSz);

  44181.         if( rc==SQLITE_OK ){

  44182.           sqlite3_int64 newSz = *(sqlite3_int64*)pArg;

  44183.           if( newSz>oldSz ){

  44184.             SimulateIOErrorBenign(1);

  44185.             rc = winTruncate(id, newSz);

  44186.             SimulateIOErrorBenign(0);

  44187.           }

  44188.         }

  44189.         OSTRACE(("FCNTL file=%p, rc=%s\n", pFile->h, sqlite3ErrName(rc)));

  44190.         return rc;

  44191.       }

  44192.       OSTRACE(("FCNTL file=%p, rc=SQLITE_OK\n", pFile->h));

  44193.       return SQLITE_OK;

  44194.     }

  44195.     case SQLITE_FCNTL_PERSIST_WAL: {

  44196.       winModeBit(pFile, WINFILE_PERSIST_WAL, (int*)pArg);

  44197.       OSTRACE(("FCNTL file=%p, rc=SQLITE_OK\n", pFile->h));

  44198.       return SQLITE_OK;

  44199.     }

  44200.     case SQLITE_FCNTL_POWERSAFE_OVERWRITE: {

  44201.       winModeBit(pFile, WINFILE_PSOW, (int*)pArg);

  44202.       OSTRACE(("FCNTL file=%p, rc=SQLITE_OK\n", pFile->h));

  44203.       return SQLITE_OK;

  44204.     }

  44205.     case SQLITE_FCNTL_VFSNAME: {

  44206.       *(char**)pArg = sqlite3_mprintf("%s", pFile->pVfs->zName);

  44207.       OSTRACE(("FCNTL file=%p, rc=SQLITE_OK\n", pFile->h));

  44208.       return SQLITE_OK;

  44209.     }

  44210.     case SQLITE_FCNTL_WIN32_AV_RETRY: {

  44211.       int *a = (int*)pArg;

  44212.       if( a[0]>0 ){

  44213.         winIoerrRetry = a[0];

  44214.       }else{

  44215.         a[0] = winIoerrRetry;

  44216.       }

  44217.       if( a[1]>0 ){

  44218.         winIoerrRetryDelay = a[1];

  44219.       }else{

  44220.         a[1] = winIoerrRetryDelay;

  44221.       }

  44222.       OSTRACE(("FCNTL file=%p, rc=SQLITE_OK\n", pFile->h));

  44223.       return SQLITE_OK;

  44224.     }

  44225.     case SQLITE_FCNTL_WIN32_GET_HANDLE: {

  44226.       LPHANDLE phFile = (LPHANDLE)pArg;

  44227.       *phFile = pFile->h;

  44228.       OSTRACE(("FCNTL file=%p, rc=SQLITE_OK\n", pFile->h));

  44229.       return SQLITE_OK;

  44230.     }

  44231. #ifdef SQLITE_TEST

  44232.     case SQLITE_FCNTL_WIN32_SET_HANDLE: {

  44233.       LPHANDLE phFile = (LPHANDLE)pArg;

  44234.       HANDLE hOldFile = pFile->h;

  44235.       pFile->h = *phFile;

  44236.       *phFile = hOldFile;

  44237.       OSTRACE(("FCNTL oldFile=%p, newFile=%p, rc=SQLITE_OK\n",

  44238.                hOldFile, pFile->h));

  44239.       return SQLITE_OK;

  44240.     }

  44241. #endif

  44242.     case SQLITE_FCNTL_TEMPFILENAME: {

  44243.       char *zTFile = 0;

  44244.       int rc = winGetTempname(pFile->pVfs, &zTFile);

  44245.       if( rc==SQLITE_OK ){

  44246.         *(char**)pArg = zTFile;

  44247.       }

  44248.       OSTRACE(("FCNTL file=%p, rc=%s\n", pFile->h, sqlite3ErrName(rc)));

  44249.       return rc;

  44250.     }

  44251. #if SQLITE_MAX_MMAP_SIZE>0

  44252.     case SQLITE_FCNTL_MMAP_SIZE: {

  44253.       i64 newLimit = *(i64*)pArg;

  44254.       int rc = SQLITE_OK;

  44255.       if( newLimit>sqlite3GlobalConfig.mxMmap ){

  44256.         newLimit = sqlite3GlobalConfig.mxMmap;

  44257.       }

  44258. 

  44259.       /* The value of newLimit may be eventually cast to (SIZE_T) and passed

  44260.       ** to MapViewOfFile(). Restrict its value to 2GB if (SIZE_T) is not at

  44261.       ** least a 64-bit type. */

  44262.       if( newLimit>0 && sizeof(SIZE_T)<8 ){

  44263.         newLimit = (newLimit & 0x7FFFFFFF);

  44264.       }

  44265. 

  44266.       *(i64*)pArg = pFile->mmapSizeMax;

  44267.       if( newLimit>=0 && newLimit!=pFile->mmapSizeMax && pFile->nFetchOut==0 ){

  44268.         pFile->mmapSizeMax = newLimit;

  44269.         if( pFile->mmapSize>0 ){

  44270.           winUnmapfile(pFile);

  44271.           rc = winMapfile(pFile, -1);

  44272.         }

  44273.       }

  44274.       OSTRACE(("FCNTL file=%p, rc=%s\n", pFile->h, sqlite3ErrName(rc)));

  44275.       return rc;

  44276.     }

  44277. #endif

  44278.   }

  44279.   OSTRACE(("FCNTL file=%p, rc=SQLITE_NOTFOUND\n", pFile->h));

  44280.   return SQLITE_NOTFOUND;

  44281. }

  44282. 

  44283. /*

  44284. ** Return the sector size in bytes of the underlying block device for

  44285. ** the specified file. This is almost always 512 bytes, but may be

  44286. ** larger for some devices.

  44287. **

  44288. ** SQLite code assumes this function cannot fail. It also assumes that

  44289. ** if two files are created in the same file-system directory (i.e.

  44290. ** a database and its journal file) that the sector size will be the

  44291. ** same for both.

  44292. */

  44293. static int winSectorSize(sqlite3_file *id){

  44294.   (void)id;

  44295.   return SQLITE_DEFAULT_SECTOR_SIZE;

  44296. }

  44297. 

  44298. /*

  44299. ** Return a vector of device characteristics.

  44300. */

  44301. static int winDeviceCharacteristics(sqlite3_file *id){

  44302.   winFile *p = (winFile*)id;

  44303.   return SQLITE_IOCAP_UNDELETABLE_WHEN_OPEN |

  44304.          ((p->ctrlFlags & WINFILE_PSOW)?SQLITE_IOCAP_POWERSAFE_OVERWRITE:0);

  44305. }

  44306. 

  44307. /*

  44308. ** Windows will only let you create file view mappings

  44309. ** on allocation size granularity boundaries.

  44310. ** During sqlite3_os_init() we do a GetSystemInfo()

  44311. ** to get the granularity size.

  44312. */

  44313. static SYSTEM_INFO winSysInfo;

  44314. 

  44315. #ifndef SQLITE_OMIT_WAL

  44316. 

  44317. /*

  44318. ** Helper functions to obtain and relinquish the global mutex. The

  44319. ** global mutex is used to protect the winLockInfo objects used by

  44320. ** this file, all of which may be shared by multiple threads.

  44321. **

  44322. ** Function winShmMutexHeld() is used to assert() that the global mutex

  44323. ** is held when required. This function is only used as part of assert()

  44324. ** statements. e.g.

  44325. **

  44326. **   winShmEnterMutex()

  44327. **     assert( winShmMutexHeld() );

  44328. **   winShmLeaveMutex()

  44329. */

  44330. static sqlite3_mutex *winBigLock = 0;

  44331. static void winShmEnterMutex(void){

  44332.   sqlite3_mutex_enter(winBigLock);

  44333. }

  44334. static void winShmLeaveMutex(void){

  44335.   sqlite3_mutex_leave(winBigLock);

  44336. }

  44337. #ifndef NDEBUG

  44338. static int winShmMutexHeld(void) {

  44339.   return sqlite3_mutex_held(winBigLock);

  44340. }

  44341. #endif

  44342. 

  44343. /*

  44344. ** Object used to represent a single file opened and mmapped to provide

  44345. ** shared memory.  When multiple threads all reference the same

  44346. ** log-summary, each thread has its own winFile object, but they all

  44347. ** point to a single instance of this object.  In other words, each

  44348. ** log-summary is opened only once per process.

  44349. **

  44350. ** winShmMutexHeld() must be true when creating or destroying

  44351. ** this object or while reading or writing the following fields:

  44352. **

  44353. **      nRef

  44354. **      pNext

  44355. **

  44356. ** The following fields are read-only after the object is created:

  44357. **

  44358. **      fid

  44359. **      zFilename

  44360. **

  44361. ** Either winShmNode.mutex must be held or winShmNode.nRef==0 and

  44362. ** winShmMutexHeld() is true when reading or writing any other field

  44363. ** in this structure.

  44364. **

  44365. */

  44366. struct winShmNode {

  44367.   sqlite3_mutex *mutex;      /* Mutex to access this object */

  44368.   char *zFilename;           /* Name of the file */

  44369.   winFile hFile;             /* File handle from winOpen */

  44370. 

  44371.   int szRegion;              /* Size of shared-memory regions */

  44372.   int nRegion;               /* Size of array apRegion */

  44373.   u8 isReadonly;             /* True if read-only */

  44374.   u8 isUnlocked;             /* True if no DMS lock held */

  44375. 

  44376.   struct ShmRegion {

  44377.     HANDLE hMap;             /* File handle from CreateFileMapping */

  44378.     void *pMap;

  44379.   } *aRegion;

  44380.   DWORD lastErrno;           /* The Windows errno from the last I/O error */

  44381. 

  44382.   int nRef;                  /* Number of winShm objects pointing to this */

  44383.   winShm *pFirst;            /* All winShm objects pointing to this */

  44384.   winShmNode *pNext;         /* Next in list of all winShmNode objects */

  44385. #if defined(SQLITE_DEBUG) || defined(SQLITE_HAVE_OS_TRACE)

  44386.   u8 nextShmId;              /* Next available winShm.id value */

  44387. #endif

  44388. };

  44389. 

  44390. /*

  44391. ** A global array of all winShmNode objects.

  44392. **

  44393. ** The winShmMutexHeld() must be true while reading or writing this list.

  44394. */

  44395. static winShmNode *winShmNodeList = 0;

  44396. 

  44397. /*

  44398. ** Structure used internally by this VFS to record the state of an

  44399. ** open shared memory connection.

  44400. **

  44401. ** The following fields are initialized when this object is created and

  44402. ** are read-only thereafter:

  44403. **

  44404. **    winShm.pShmNode

  44405. **    winShm.id

  44406. **

  44407. ** All other fields are read/write.  The winShm.pShmNode->mutex must be held

  44408. ** while accessing any read/write fields.

  44409. */

  44410. struct winShm {

  44411.   winShmNode *pShmNode;      /* The underlying winShmNode object */

  44412.   winShm *pNext;             /* Next winShm with the same winShmNode */

  44413.   u8 hasMutex;               /* True if holding the winShmNode mutex */

  44414.   u16 sharedMask;            /* Mask of shared locks held */

  44415.   u16 exclMask;              /* Mask of exclusive locks held */

  44416. #if defined(SQLITE_DEBUG) || defined(SQLITE_HAVE_OS_TRACE)

  44417.   u8 id;                     /* Id of this connection with its winShmNode */

  44418. #endif

  44419. };

  44420. 

  44421. /*

  44422. ** Constants used for locking

  44423. */

  44424. #define WIN_SHM_BASE   ((22+SQLITE_SHM_NLOCK)*4)        /* first lock byte */

  44425. #define WIN_SHM_DMS    (WIN_SHM_BASE+SQLITE_SHM_NLOCK)  /* deadman switch */

  44426. 

  44427. /*

  44428. ** Apply advisory locks for all n bytes beginning at ofst.

  44429. */

  44430. #define WINSHM_UNLCK  1

  44431. #define WINSHM_RDLCK  2

  44432. #define WINSHM_WRLCK  3

  44433. static int winShmSystemLock(

  44434.   winShmNode *pFile,    /* Apply locks to this open shared-memory segment */

  44435.   int lockType,         /* WINSHM_UNLCK, WINSHM_RDLCK, or WINSHM_WRLCK */

  44436.   int ofst,             /* Offset to first byte to be locked/unlocked */

  44437.   int nByte             /* Number of bytes to lock or unlock */

  44438. ){

  44439.   int rc = 0;           /* Result code form Lock/UnlockFileEx() */

  44440. 

  44441.   /* Access to the winShmNode object is serialized by the caller */

  44442.   assert( pFile->nRef==0 || sqlite3_mutex_held(pFile->mutex) );

  44443. 

  44444.   OSTRACE(("SHM-LOCK file=%p, lock=%d, offset=%d, size=%d\n",

  44445.            pFile->hFile.h, lockType, ofst, nByte));

  44446. 

  44447.   /* Release/Acquire the system-level lock */

  44448.   if( lockType==WINSHM_UNLCK ){

  44449.     rc = winUnlockFile(&pFile->hFile.h, ofst, 0, nByte, 0);

  44450.   }else{

  44451.     /* Initialize the locking parameters */

  44452.     DWORD dwFlags = LOCKFILE_FAIL_IMMEDIATELY;

  44453.     if( lockType == WINSHM_WRLCK ) dwFlags |= LOCKFILE_EXCLUSIVE_LOCK;

  44454.     rc = winLockFile(&pFile->hFile.h, dwFlags, ofst, 0, nByte, 0);

  44455.   }

  44456. 

  44457.   if( rc!= 0 ){

  44458.     rc = SQLITE_OK;

  44459.   }else{

  44460.     pFile->lastErrno =  osGetLastError();

  44461.     rc = SQLITE_BUSY;

  44462.   }

  44463. 

  44464.   OSTRACE(("SHM-LOCK file=%p, func=%s, errno=%lu, rc=%s\n",

  44465.            pFile->hFile.h, (lockType == WINSHM_UNLCK) ? "winUnlockFile" :

  44466.            "winLockFile", pFile->lastErrno, sqlite3ErrName(rc)));

  44467. 

  44468.   return rc;

  44469. }

  44470. 

  44471. /* Forward references to VFS methods */

  44472. static int winOpen(sqlite3_vfs*,const char*,sqlite3_file*,int,int*);

  44473. static int winDelete(sqlite3_vfs *,const char*,int);

  44474. 

  44475. /*

  44476. ** Purge the winShmNodeList list of all entries with winShmNode.nRef==0.

  44477. **

  44478. ** This is not a VFS shared-memory method; it is a utility function called

  44479. ** by VFS shared-memory methods.

  44480. */

  44481. static void winShmPurge(sqlite3_vfs *pVfs, int deleteFlag){

  44482.   winShmNode **pp;

  44483.   winShmNode *p;

  44484.   assert( winShmMutexHeld() );

  44485.   OSTRACE(("SHM-PURGE pid=%lu, deleteFlag=%d\n",

  44486.            osGetCurrentProcessId(), deleteFlag));

  44487.   pp = &winShmNodeList;

  44488.   while( (p = *pp)!=0 ){

  44489.     if( p->nRef==0 ){

  44490.       int i;

  44491.       if( p->mutex ){ sqlite3_mutex_free(p->mutex); }

  44492.       for(i=0; i<p->nRegion; i++){

  44493.         BOOL bRc = osUnmapViewOfFile(p->aRegion[i].pMap);

  44494.         OSTRACE(("SHM-PURGE-UNMAP pid=%lu, region=%d, rc=%s\n",

  44495.                  osGetCurrentProcessId(), i, bRc ? "ok" : "failed"));

  44496.         UNUSED_VARIABLE_VALUE(bRc);

  44497.         bRc = osCloseHandle(p->aRegion[i].hMap);

  44498.         OSTRACE(("SHM-PURGE-CLOSE pid=%lu, region=%d, rc=%s\n",

  44499.                  osGetCurrentProcessId(), i, bRc ? "ok" : "failed"));

  44500.         UNUSED_VARIABLE_VALUE(bRc);

  44501.       }

  44502.       if( p->hFile.h!=NULL && p->hFile.h!=INVALID_HANDLE_VALUE ){

  44503.         SimulateIOErrorBenign(1);

  44504.         winClose((sqlite3_file *)&p->hFile);

  44505.         SimulateIOErrorBenign(0);

  44506.       }

  44507.       if( deleteFlag ){

  44508.         SimulateIOErrorBenign(1);

  44509.         sqlite3BeginBenignMalloc();

  44510.         winDelete(pVfs, p->zFilename, 0);

  44511.         sqlite3EndBenignMalloc();

  44512.         SimulateIOErrorBenign(0);

  44513.       }

  44514.       *pp = p->pNext;

  44515.       sqlite3_free(p->aRegion);

  44516.       sqlite3_free(p);

  44517.     }else{

  44518.       pp = &p->pNext;

  44519.     }

  44520.   }

  44521. }

  44522. 

  44523. /*

  44524. ** The DMS lock has not yet been taken on shm file pShmNode. Attempt to

  44525. ** take it now. Return SQLITE_OK if successful, or an SQLite error

  44526. ** code otherwise.

  44527. **

  44528. ** If the DMS cannot be locked because this is a readonly_shm=1

  44529. ** connection and no other process already holds a lock, return

  44530. ** SQLITE_READONLY_CANTINIT and set pShmNode->isUnlocked=1.

  44531. */

  44532. static int winLockSharedMemory(winShmNode *pShmNode){

  44533.   int rc = winShmSystemLock(pShmNode, WINSHM_WRLCK, WIN_SHM_DMS, 1);

  44534. 

  44535.   if( rc==SQLITE_OK ){

  44536.     if( pShmNode->isReadonly ){

  44537.       pShmNode->isUnlocked = 1;

  44538.       winShmSystemLock(pShmNode, WINSHM_UNLCK, WIN_SHM_DMS, 1);

  44539.       return SQLITE_READONLY_CANTINIT;

  44540.     }else if( winTruncate((sqlite3_file*)&pShmNode->hFile, 0) ){

  44541.       winShmSystemLock(pShmNode, WINSHM_UNLCK, WIN_SHM_DMS, 1);

  44542.       return winLogError(SQLITE_IOERR_SHMOPEN, osGetLastError(),

  44543.                          "winLockSharedMemory", pShmNode->zFilename);

  44544.     }

  44545.   }

  44546. 

  44547.   if( rc==SQLITE_OK ){

  44548.     winShmSystemLock(pShmNode, WINSHM_UNLCK, WIN_SHM_DMS, 1);

  44549.   }

  44550. 

  44551.   return winShmSystemLock(pShmNode, WINSHM_RDLCK, WIN_SHM_DMS, 1);

  44552. }

  44553. 

  44554. /*

  44555. ** Open the shared-memory area associated with database file pDbFd.

  44556. **

  44557. ** When opening a new shared-memory file, if no other instances of that

  44558. ** file are currently open, in this process or in other processes, then

  44559. ** the file must be truncated to zero length or have its header cleared.

  44560. */

  44561. static int winOpenSharedMemory(winFile *pDbFd){

  44562.   struct winShm *p;                  /* The connection to be opened */

  44563.   winShmNode *pShmNode = 0;          /* The underlying mmapped file */

  44564.   int rc = SQLITE_OK;                /* Result code */

  44565.   winShmNode *pNew;                  /* Newly allocated winShmNode */

  44566.   int nName;                         /* Size of zName in bytes */

  44567. 

  44568.   assert( pDbFd->pShm==0 );    /* Not previously opened */

  44569. 

  44570.   /* Allocate space for the new sqlite3_shm object.  Also speculatively

  44571.   ** allocate space for a new winShmNode and filename.

  44572.   */

  44573.   p = sqlite3MallocZero( sizeof(*p) );

  44574.   if( p==0 ) return SQLITE_IOERR_NOMEM_BKPT;

  44575.   nName = sqlite3Strlen30(pDbFd->zPath);

  44576.   pNew = sqlite3MallocZero( sizeof(*pShmNode) + nName + 17 );

  44577.   if( pNew==0 ){

  44578.     sqlite3_free(p);

  44579.     return SQLITE_IOERR_NOMEM_BKPT;

  44580.   }

  44581.   pNew->zFilename = (char*)&pNew[1];

  44582.   sqlite3_snprintf(nName+15, pNew->zFilename, "%s-shm", pDbFd->zPath);

  44583.   sqlite3FileSuffix3(pDbFd->zPath, pNew->zFilename);

  44584. 

  44585.   /* Look to see if there is an existing winShmNode that can be used.

  44586.   ** If no matching winShmNode currently exists, create a new one.

  44587.   */

  44588.   winShmEnterMutex();

  44589.   for(pShmNode = winShmNodeList; pShmNode; pShmNode=pShmNode->pNext){

  44590.     /* TBD need to come up with better match here.  Perhaps

  44591.     ** use FILE_ID_BOTH_DIR_INFO Structure.

  44592.     */

  44593.     if( sqlite3StrICmp(pShmNode->zFilename, pNew->zFilename)==0 ) break;

  44594.   }

  44595.   if( pShmNode ){

  44596.     sqlite3_free(pNew);

  44597.   }else{

  44598.     int inFlags = SQLITE_OPEN_WAL;

  44599.     int outFlags = 0;

  44600. 

  44601.     pShmNode = pNew;

  44602.     pNew = 0;

  44603.     ((winFile*)(&pShmNode->hFile))->h = INVALID_HANDLE_VALUE;

  44604.     pShmNode->pNext = winShmNodeList;

  44605.     winShmNodeList = pShmNode;

  44606. 

  44607.     if( sqlite3GlobalConfig.bCoreMutex ){

  44608.       pShmNode->mutex = sqlite3_mutex_alloc(SQLITE_MUTEX_FAST);

  44609.       if( pShmNode->mutex==0 ){

  44610.         rc = SQLITE_IOERR_NOMEM_BKPT;

  44611.         goto shm_open_err;

  44612.       }

  44613.     }

  44614. 

  44615.     if( 0==sqlite3_uri_boolean(pDbFd->zPath, "readonly_shm", 0) ){

  44616.       inFlags |= SQLITE_OPEN_READWRITE | SQLITE_OPEN_CREATE;

  44617.     }else{

  44618.       inFlags |= SQLITE_OPEN_READONLY;

  44619.     }

  44620.     rc = winOpen(pDbFd->pVfs, pShmNode->zFilename,

  44621.                  (sqlite3_file*)&pShmNode->hFile,

  44622.                  inFlags, &outFlags);

  44623.     if( rc!=SQLITE_OK ){

  44624.       rc = winLogError(rc, osGetLastError(), "winOpenShm",

  44625.                        pShmNode->zFilename);

  44626.       goto shm_open_err;

  44627.     }

  44628.     if( outFlags==SQLITE_OPEN_READONLY ) pShmNode->isReadonly = 1;

  44629. 

  44630.     rc = winLockSharedMemory(pShmNode);

  44631.     if( rc!=SQLITE_OK && rc!=SQLITE_READONLY_CANTINIT ) goto shm_open_err;

  44632.   }

  44633. 

  44634.   /* Make the new connection a child of the winShmNode */

  44635.   p->pShmNode = pShmNode;

  44636. #if defined(SQLITE_DEBUG) || defined(SQLITE_HAVE_OS_TRACE)

  44637.   p->id = pShmNode->nextShmId++;

  44638. #endif

  44639.   pShmNode->nRef++;

  44640.   pDbFd->pShm = p;

  44641.   winShmLeaveMutex();

  44642. 

  44643.   /* The reference count on pShmNode has already been incremented under

  44644.   ** the cover of the winShmEnterMutex() mutex and the pointer from the

  44645.   ** new (struct winShm) object to the pShmNode has been set. All that is

  44646.   ** left to do is to link the new object into the linked list starting

  44647.   ** at pShmNode->pFirst. This must be done while holding the pShmNode->mutex

  44648.   ** mutex.

  44649.   */

  44650.   sqlite3_mutex_enter(pShmNode->mutex);

  44651.   p->pNext = pShmNode->pFirst;

  44652.   pShmNode->pFirst = p;

  44653.   sqlite3_mutex_leave(pShmNode->mutex);

  44654.   return rc;

  44655. 

  44656.   /* Jump here on any error */

  44657. shm_open_err:

  44658.   winShmSystemLock(pShmNode, WINSHM_UNLCK, WIN_SHM_DMS, 1);

  44659.   winShmPurge(pDbFd->pVfs, 0);      /* This call frees pShmNode if required */

  44660.   sqlite3_free(p);

  44661.   sqlite3_free(pNew);

  44662.   winShmLeaveMutex();

  44663.   return rc;

  44664. }

  44665. 

  44666. /*

  44667. ** Close a connection to shared-memory.  Delete the underlying

  44668. ** storage if deleteFlag is true.

  44669. */

  44670. static int winShmUnmap(

  44671.   sqlite3_file *fd,          /* Database holding shared memory */

  44672.   int deleteFlag             /* Delete after closing if true */

  44673. ){

  44674.   winFile *pDbFd;       /* Database holding shared-memory */

  44675.   winShm *p;            /* The connection to be closed */

  44676.   winShmNode *pShmNode; /* The underlying shared-memory file */

  44677.   winShm **pp;          /* For looping over sibling connections */

  44678. 

  44679.   pDbFd = (winFile*)fd;

  44680.   p = pDbFd->pShm;

  44681.   if( p==0 ) return SQLITE_OK;

  44682.   pShmNode = p->pShmNode;

  44683. 

  44684.   /* Remove connection p from the set of connections associated

  44685.   ** with pShmNode */

  44686.   sqlite3_mutex_enter(pShmNode->mutex);

  44687.   for(pp=&pShmNode->pFirst; (*pp)!=p; pp = &(*pp)->pNext){}

  44688.   *pp = p->pNext;

  44689. 

  44690.   /* Free the connection p */

  44691.   sqlite3_free(p);

  44692.   pDbFd->pShm = 0;

  44693.   sqlite3_mutex_leave(pShmNode->mutex);

  44694. 

  44695.   /* If pShmNode->nRef has reached 0, then close the underlying

  44696.   ** shared-memory file, too */

  44697.   winShmEnterMutex();

  44698.   assert( pShmNode->nRef>0 );

  44699.   pShmNode->nRef--;

  44700.   if( pShmNode->nRef==0 ){

  44701.     winShmPurge(pDbFd->pVfs, deleteFlag);

  44702.   }

  44703.   winShmLeaveMutex();

  44704. 

  44705.   return SQLITE_OK;

  44706. }

  44707. 

  44708. /*

  44709. ** Change the lock state for a shared-memory segment.

  44710. */

  44711. static int winShmLock(

  44712.   sqlite3_file *fd,          /* Database file holding the shared memory */

  44713.   int ofst,                  /* First lock to acquire or release */

  44714.   int n,                     /* Number of locks to acquire or release */

  44715.   int flags                  /* What to do with the lock */

  44716. ){

  44717.   winFile *pDbFd = (winFile*)fd;        /* Connection holding shared memory */

  44718.   winShm *p = pDbFd->pShm;              /* The shared memory being locked */

  44719.   winShm *pX;                           /* For looping over all siblings */

  44720.   winShmNode *pShmNode = p->pShmNode;

  44721.   int rc = SQLITE_OK;                   /* Result code */

  44722.   u16 mask;                             /* Mask of locks to take or release */

  44723. 

  44724.   assert( ofst>=0 && ofst+n<=SQLITE_SHM_NLOCK );

  44725.   assert( n>=1 );

  44726.   assert( flags==(SQLITE_SHM_LOCK | SQLITE_SHM_SHARED)

  44727.        || flags==(SQLITE_SHM_LOCK | SQLITE_SHM_EXCLUSIVE)

  44728.        || flags==(SQLITE_SHM_UNLOCK | SQLITE_SHM_SHARED)

  44729.        || flags==(SQLITE_SHM_UNLOCK | SQLITE_SHM_EXCLUSIVE) );

  44730.   assert( n==1 || (flags & SQLITE_SHM_EXCLUSIVE)!=0 );

  44731. 

  44732.   mask = (u16)((1U<<(ofst+n)) - (1U<<ofst));

  44733.   assert( n>1 || mask==(1<<ofst) );

  44734.   sqlite3_mutex_enter(pShmNode->mutex);

  44735.   if( flags & SQLITE_SHM_UNLOCK ){

  44736.     u16 allMask = 0; /* Mask of locks held by siblings */

  44737. 

  44738.     /* See if any siblings hold this same lock */

  44739.     for(pX=pShmNode->pFirst; pX; pX=pX->pNext){

  44740.       if( pX==p ) continue;

  44741.       assert( (pX->exclMask & (p->exclMask|p->sharedMask))==0 );

  44742.       allMask |= pX->sharedMask;

  44743.     }

  44744. 

  44745.     /* Unlock the system-level locks */

  44746.     if( (mask & allMask)==0 ){

  44747.       rc = winShmSystemLock(pShmNode, WINSHM_UNLCK, ofst+WIN_SHM_BASE, n);

  44748.     }else{

  44749.       rc = SQLITE_OK;

  44750.     }

  44751. 

  44752.     /* Undo the local locks */

  44753.     if( rc==SQLITE_OK ){

  44754.       p->exclMask &= ~mask;

  44755.       p->sharedMask &= ~mask;

  44756.     }

  44757.   }else if( flags & SQLITE_SHM_SHARED ){

  44758.     u16 allShared = 0;  /* Union of locks held by connections other than "p" */

  44759. 

  44760.     /* Find out which shared locks are already held by sibling connections.

  44761.     ** If any sibling already holds an exclusive lock, go ahead and return

  44762.     ** SQLITE_BUSY.

  44763.     */

  44764.     for(pX=pShmNode->pFirst; pX; pX=pX->pNext){

  44765.       if( (pX->exclMask & mask)!=0 ){

  44766.         rc = SQLITE_BUSY;

  44767.         break;

  44768.       }

  44769.       allShared |= pX->sharedMask;

  44770.     }

  44771. 

  44772.     /* Get shared locks at the system level, if necessary */

  44773.     if( rc==SQLITE_OK ){

  44774.       if( (allShared & mask)==0 ){

  44775.         rc = winShmSystemLock(pShmNode, WINSHM_RDLCK, ofst+WIN_SHM_BASE, n);

  44776.       }else{

  44777.         rc = SQLITE_OK;

  44778.       }

  44779.     }

  44780. 

  44781.     /* Get the local shared locks */

  44782.     if( rc==SQLITE_OK ){

  44783.       p->sharedMask |= mask;

  44784.     }

  44785.   }else{

  44786.     /* Make sure no sibling connections hold locks that will block this

  44787.     ** lock.  If any do, return SQLITE_BUSY right away.

  44788.     */

  44789.     for(pX=pShmNode->pFirst; pX; pX=pX->pNext){

  44790.       if( (pX->exclMask & mask)!=0 || (pX->sharedMask & mask)!=0 ){

  44791.         rc = SQLITE_BUSY;

  44792.         break;

  44793.       }

  44794.     }

  44795. 

  44796.     /* Get the exclusive locks at the system level.  Then if successful

  44797.     ** also mark the local connection as being locked.

  44798.     */

  44799.     if( rc==SQLITE_OK ){

  44800.       rc = winShmSystemLock(pShmNode, WINSHM_WRLCK, ofst+WIN_SHM_BASE, n);

  44801.       if( rc==SQLITE_OK ){

  44802.         assert( (p->sharedMask & mask)==0 );

  44803.         p->exclMask |= mask;

  44804.       }

  44805.     }

  44806.   }

  44807.   sqlite3_mutex_leave(pShmNode->mutex);

  44808.   OSTRACE(("SHM-LOCK pid=%lu, id=%d, sharedMask=%03x, exclMask=%03x, rc=%s\n",

  44809.            osGetCurrentProcessId(), p->id, p->sharedMask, p->exclMask,

  44810.            sqlite3ErrName(rc)));

  44811.   return rc;

  44812. }

  44813. 

  44814. /*

  44815. ** Implement a memory barrier or memory fence on shared memory.

  44816. **

  44817. ** All loads and stores begun before the barrier must complete before

  44818. ** any load or store begun after the barrier.

  44819. */

  44820. static void winShmBarrier(

  44821.   sqlite3_file *fd          /* Database holding the shared memory */

  44822. ){

  44823.   UNUSED_PARAMETER(fd);

  44824.   sqlite3MemoryBarrier();   /* compiler-defined memory barrier */

  44825.   winShmEnterMutex();       /* Also mutex, for redundancy */

  44826.   winShmLeaveMutex();

  44827. }

  44828. 

  44829. /*

  44830. ** This function is called to obtain a pointer to region iRegion of the

  44831. ** shared-memory associated with the database file fd. Shared-memory regions

  44832. ** are numbered starting from zero. Each shared-memory region is szRegion

  44833. ** bytes in size.

  44834. **

  44835. ** If an error occurs, an error code is returned and *pp is set to NULL.

  44836. **

  44837. ** Otherwise, if the isWrite parameter is 0 and the requested shared-memory

  44838. ** region has not been allocated (by any client, including one running in a

  44839. ** separate process), then *pp is set to NULL and SQLITE_OK returned. If

  44840. ** isWrite is non-zero and the requested shared-memory region has not yet

  44841. ** been allocated, it is allocated by this function.

  44842. **

  44843. ** If the shared-memory region has already been allocated or is allocated by

  44844. ** this call as described above, then it is mapped into this processes

  44845. ** address space (if it is not already), *pp is set to point to the mapped

  44846. ** memory and SQLITE_OK returned.

  44847. */

  44848. static int winShmMap(

  44849.   sqlite3_file *fd,               /* Handle open on database file */

  44850.   int iRegion,                    /* Region to retrieve */

  44851.   int szRegion,                   /* Size of regions */

  44852.   int isWrite,                    /* True to extend file if necessary */

  44853.   void volatile **pp              /* OUT: Mapped memory */

  44854. ){

  44855.   winFile *pDbFd = (winFile*)fd;

  44856.   winShm *pShm = pDbFd->pShm;

  44857.   winShmNode *pShmNode;

  44858.   DWORD protect = PAGE_READWRITE;

  44859.   DWORD flags = FILE_MAP_WRITE | FILE_MAP_READ;

  44860.   int rc = SQLITE_OK;

  44861. 

  44862.   if( !pShm ){

  44863.     rc = winOpenSharedMemory(pDbFd);

  44864.     if( rc!=SQLITE_OK ) return rc;

  44865.     pShm = pDbFd->pShm;

  44866.   }

  44867.   pShmNode = pShm->pShmNode;

  44868. 

  44869.   sqlite3_mutex_enter(pShmNode->mutex);

  44870.   if( pShmNode->isUnlocked ){

  44871.     rc = winLockSharedMemory(pShmNode);

  44872.     if( rc!=SQLITE_OK ) goto shmpage_out;

  44873.     pShmNode->isUnlocked = 0;

  44874.   }

  44875.   assert( szRegion==pShmNode->szRegion || pShmNode->nRegion==0 );

  44876. 

  44877.   if( pShmNode->nRegion<=iRegion ){

  44878.     struct ShmRegion *apNew;           /* New aRegion[] array */

  44879.     int nByte = (iRegion+1)*szRegion;  /* Minimum required file size */

  44880.     sqlite3_int64 sz;                  /* Current size of wal-index file */

  44881. 

  44882.     pShmNode->szRegion = szRegion;

  44883. 

  44884.     /* The requested region is not mapped into this processes address space.

  44885.     ** Check to see if it has been allocated (i.e. if the wal-index file is

  44886.     ** large enough to contain the requested region).

  44887.     */

  44888.     rc = winFileSize((sqlite3_file *)&pShmNode->hFile, &sz);

  44889.     if( rc!=SQLITE_OK ){

  44890.       rc = winLogError(SQLITE_IOERR_SHMSIZE, osGetLastError(),

  44891.                        "winShmMap1", pDbFd->zPath);

  44892.       goto shmpage_out;

  44893.     }

  44894. 

  44895.     if( sz<nByte ){

  44896.       /* The requested memory region does not exist. If isWrite is set to

  44897.       ** zero, exit early. *pp will be set to NULL and SQLITE_OK returned.

  44898.       **

  44899.       ** Alternatively, if isWrite is non-zero, use ftruncate() to allocate

  44900.       ** the requested memory region.

  44901.       */

  44902.       if( !isWrite ) goto shmpage_out;

  44903.       rc = winTruncate((sqlite3_file *)&pShmNode->hFile, nByte);

  44904.       if( rc!=SQLITE_OK ){

  44905.         rc = winLogError(SQLITE_IOERR_SHMSIZE, osGetLastError(),

  44906.                          "winShmMap2", pDbFd->zPath);

  44907.         goto shmpage_out;

  44908.       }

  44909.     }

  44910. 

  44911.     /* Map the requested memory region into this processes address space. */

  44912.     apNew = (struct ShmRegion *)sqlite3_realloc64(

  44913.         pShmNode->aRegion, (iRegion+1)*sizeof(apNew[0])

  44914.     );

  44915.     if( !apNew ){

  44916.       rc = SQLITE_IOERR_NOMEM_BKPT;

  44917.       goto shmpage_out;

  44918.     }

  44919.     pShmNode->aRegion = apNew;

  44920. 

  44921.     if( pShmNode->isReadonly ){

  44922.       protect = PAGE_READONLY;

  44923.       flags = FILE_MAP_READ;

  44924.     }

  44925. 

  44926.     while( pShmNode->nRegion<=iRegion ){

  44927.       HANDLE hMap = NULL;         /* file-mapping handle */

  44928.       void *pMap = 0;             /* Mapped memory region */

  44929. 

  44930. #if SQLITE_OS_WINRT

  44931.       hMap = osCreateFileMappingFromApp(pShmNode->hFile.h,

  44932.           NULL, protect, nByte, NULL

  44933.       );

  44934. #elif defined(SQLITE_WIN32_HAS_WIDE)

  44935.       hMap = osCreateFileMappingW(pShmNode->hFile.h,

  44936.           NULL, protect, 0, nByte, NULL

  44937.       );

  44938. #elif defined(SQLITE_WIN32_HAS_ANSI) && SQLITE_WIN32_CREATEFILEMAPPINGA

  44939.       hMap = osCreateFileMappingA(pShmNode->hFile.h,

  44940.           NULL, protect, 0, nByte, NULL

  44941.       );

  44942. #endif

  44943.       OSTRACE(("SHM-MAP-CREATE pid=%lu, region=%d, size=%d, rc=%s\n",

  44944.                osGetCurrentProcessId(), pShmNode->nRegion, nByte,

  44945.                hMap ? "ok" : "failed"));

  44946.       if( hMap ){

  44947.         int iOffset = pShmNode->nRegion*szRegion;

  44948.         int iOffsetShift = iOffset % winSysInfo.dwAllocationGranularity;

  44949. #if SQLITE_OS_WINRT

  44950.         pMap = osMapViewOfFileFromApp(hMap, flags,

  44951.             iOffset - iOffsetShift, szRegion + iOffsetShift

  44952.         );

  44953. #else

  44954.         pMap = osMapViewOfFile(hMap, flags,

  44955.             0, iOffset - iOffsetShift, szRegion + iOffsetShift

  44956.         );

  44957. #endif

  44958.         OSTRACE(("SHM-MAP-MAP pid=%lu, region=%d, offset=%d, size=%d, rc=%s\n",

  44959.                  osGetCurrentProcessId(), pShmNode->nRegion, iOffset,

  44960.                  szRegion, pMap ? "ok" : "failed"));

  44961.       }

  44962.       if( !pMap ){

  44963.         pShmNode->lastErrno = osGetLastError();

  44964.         rc = winLogError(SQLITE_IOERR_SHMMAP, pShmNode->lastErrno,

  44965.                          "winShmMap3", pDbFd->zPath);

  44966.         if( hMap ) osCloseHandle(hMap);

  44967.         goto shmpage_out;

  44968.       }

  44969. 

  44970.       pShmNode->aRegion[pShmNode->nRegion].pMap = pMap;

  44971.       pShmNode->aRegion[pShmNode->nRegion].hMap = hMap;

  44972.       pShmNode->nRegion++;

  44973.     }

  44974.   }

  44975. 

  44976. shmpage_out:

  44977.   if( pShmNode->nRegion>iRegion ){

  44978.     int iOffset = iRegion*szRegion;

  44979.     int iOffsetShift = iOffset % winSysInfo.dwAllocationGranularity;

  44980.     char *p = (char *)pShmNode->aRegion[iRegion].pMap;

  44981.     *pp = (void *)&p[iOffsetShift];

  44982.   }else{

  44983.     *pp = 0;

  44984.   }

  44985.   if( pShmNode->isReadonly && rc==SQLITE_OK ) rc = SQLITE_READONLY;

  44986.   sqlite3_mutex_leave(pShmNode->mutex);

  44987.   return rc;

  44988. }

  44989. 

  44990. #else

  44991. # define winShmMap     0

  44992. # define winShmLock    0

  44993. # define winShmBarrier 0

  44994. # define winShmUnmap   0

  44995. #endif /* #ifndef SQLITE_OMIT_WAL */

  44996. 

  44997. /*

  44998. ** Cleans up the mapped region of the specified file, if any.

  44999. */

  45000. #if SQLITE_MAX_MMAP_SIZE>0

  45001. static int winUnmapfile(winFile *pFile){

  45002.   assert( pFile!=0 );

  45003.   OSTRACE(("UNMAP-FILE pid=%lu, pFile=%p, hMap=%p, pMapRegion=%p, "

  45004.            "mmapSize=%lld, mmapSizeMax=%lld\n",

  45005.            osGetCurrentProcessId(), pFile, pFile->hMap, pFile->pMapRegion,

  45006.            pFile->mmapSize, pFile->mmapSizeMax));

  45007.   if( pFile->pMapRegion ){

  45008.     if( !osUnmapViewOfFile(pFile->pMapRegion) ){

  45009.       pFile->lastErrno = osGetLastError();

  45010.       OSTRACE(("UNMAP-FILE pid=%lu, pFile=%p, pMapRegion=%p, "

  45011.                "rc=SQLITE_IOERR_MMAP\n", osGetCurrentProcessId(), pFile,

  45012.                pFile->pMapRegion));

  45013.       return winLogError(SQLITE_IOERR_MMAP, pFile->lastErrno,

  45014.                          "winUnmapfile1", pFile->zPath);

  45015.     }

  45016.     pFile->pMapRegion = 0;

  45017.     pFile->mmapSize = 0;

  45018.   }

  45019.   if( pFile->hMap!=NULL ){

  45020.     if( !osCloseHandle(pFile->hMap) ){

  45021.       pFile->lastErrno = osGetLastError();

  45022.       OSTRACE(("UNMAP-FILE pid=%lu, pFile=%p, hMap=%p, rc=SQLITE_IOERR_MMAP\n",

  45023.                osGetCurrentProcessId(), pFile, pFile->hMap));

  45024.       return winLogError(SQLITE_IOERR_MMAP, pFile->lastErrno,

  45025.                          "winUnmapfile2", pFile->zPath);

  45026.     }

  45027.     pFile->hMap = NULL;

  45028.   }

  45029.   OSTRACE(("UNMAP-FILE pid=%lu, pFile=%p, rc=SQLITE_OK\n",

  45030.            osGetCurrentProcessId(), pFile));

  45031.   return SQLITE_OK;

  45032. }

  45033. 

  45034. /*

  45035. ** Memory map or remap the file opened by file-descriptor pFd (if the file

  45036. ** is already mapped, the existing mapping is replaced by the new). Or, if

  45037. ** there already exists a mapping for this file, and there are still

  45038. ** outstanding xFetch() references to it, this function is a no-op.

  45039. **

  45040. ** If parameter nByte is non-negative, then it is the requested size of

  45041. ** the mapping to create. Otherwise, if nByte is less than zero, then the

  45042. ** requested size is the size of the file on disk. The actual size of the

  45043. ** created mapping is either the requested size or the value configured

  45044. ** using SQLITE_FCNTL_MMAP_SIZE, whichever is smaller.

  45045. **

  45046. ** SQLITE_OK is returned if no error occurs (even if the mapping is not

  45047. ** recreated as a result of outstanding references) or an SQLite error

  45048. ** code otherwise.

  45049. */

  45050. static int winMapfile(winFile *pFd, sqlite3_int64 nByte){

  45051.   sqlite3_int64 nMap = nByte;

  45052.   int rc;

  45053. 

  45054.   assert( nMap>=0 || pFd->nFetchOut==0 );

  45055.   OSTRACE(("MAP-FILE pid=%lu, pFile=%p, size=%lld\n",

  45056.            osGetCurrentProcessId(), pFd, nByte));

  45057. 

  45058.   if( pFd->nFetchOut>0 ) return SQLITE_OK;

  45059. 

  45060.   if( nMap<0 ){

  45061.     rc = winFileSize((sqlite3_file*)pFd, &nMap);

  45062.     if( rc ){

  45063.       OSTRACE(("MAP-FILE pid=%lu, pFile=%p, rc=SQLITE_IOERR_FSTAT\n",

  45064.                osGetCurrentProcessId(), pFd));

  45065.       return SQLITE_IOERR_FSTAT;

  45066.     }

  45067.   }

  45068.   if( nMap>pFd->mmapSizeMax ){

  45069.     nMap = pFd->mmapSizeMax;

  45070.   }

  45071.   nMap &= ~(sqlite3_int64)(winSysInfo.dwPageSize - 1);

  45072. 

  45073.   if( nMap==0 && pFd->mmapSize>0 ){

  45074.     winUnmapfile(pFd);

  45075.   }

  45076.   if( nMap!=pFd->mmapSize ){

  45077.     void *pNew = 0;

  45078.     DWORD protect = PAGE_READONLY;

  45079.     DWORD flags = FILE_MAP_READ;

  45080. 

  45081.     winUnmapfile(pFd);

  45082. #ifdef SQLITE_MMAP_READWRITE

  45083.     if( (pFd->ctrlFlags & WINFILE_RDONLY)==0 ){

  45084.       protect = PAGE_READWRITE;

  45085.       flags |= FILE_MAP_WRITE;

  45086.     }

  45087. #endif

  45088. #if SQLITE_OS_WINRT

  45089.     pFd->hMap = osCreateFileMappingFromApp(pFd->h, NULL, protect, nMap, NULL);

  45090. #elif defined(SQLITE_WIN32_HAS_WIDE)

  45091.     pFd->hMap = osCreateFileMappingW(pFd->h, NULL, protect,

  45092.                                 (DWORD)((nMap>>32) & 0xffffffff),

  45093.                                 (DWORD)(nMap & 0xffffffff), NULL);

  45094. #elif defined(SQLITE_WIN32_HAS_ANSI) && SQLITE_WIN32_CREATEFILEMAPPINGA

  45095.     pFd->hMap = osCreateFileMappingA(pFd->h, NULL, protect,

  45096.                                 (DWORD)((nMap>>32) & 0xffffffff),

  45097.                                 (DWORD)(nMap & 0xffffffff), NULL);

  45098. #endif

  45099.     if( pFd->hMap==NULL ){

  45100.       pFd->lastErrno = osGetLastError();

  45101.       rc = winLogError(SQLITE_IOERR_MMAP, pFd->lastErrno,

  45102.                        "winMapfile1", pFd->zPath);

  45103.       /* Log the error, but continue normal operation using xRead/xWrite */

  45104.       OSTRACE(("MAP-FILE-CREATE pid=%lu, pFile=%p, rc=%s\n",

  45105.                osGetCurrentProcessId(), pFd, sqlite3ErrName(rc)));

  45106.       return SQLITE_OK;

  45107.     }

  45108.     assert( (nMap % winSysInfo.dwPageSize)==0 );

  45109.     assert( sizeof(SIZE_T)==sizeof(sqlite3_int64) || nMap<=0xffffffff );

  45110. #if SQLITE_OS_WINRT

  45111.     pNew = osMapViewOfFileFromApp(pFd->hMap, flags, 0, (SIZE_T)nMap);

  45112. #else

  45113.     pNew = osMapViewOfFile(pFd->hMap, flags, 0, 0, (SIZE_T)nMap);

  45114. #endif

  45115.     if( pNew==NULL ){

  45116.       osCloseHandle(pFd->hMap);

  45117.       pFd->hMap = NULL;

  45118.       pFd->lastErrno = osGetLastError();

  45119.       rc = winLogError(SQLITE_IOERR_MMAP, pFd->lastErrno,

  45120.                        "winMapfile2", pFd->zPath);

  45121.       /* Log the error, but continue normal operation using xRead/xWrite */

  45122.       OSTRACE(("MAP-FILE-MAP pid=%lu, pFile=%p, rc=%s\n",

  45123.                osGetCurrentProcessId(), pFd, sqlite3ErrName(rc)));

  45124.       return SQLITE_OK;

  45125.     }

  45126.     pFd->pMapRegion = pNew;

  45127.     pFd->mmapSize = nMap;

  45128.   }

  45129. 

  45130.   OSTRACE(("MAP-FILE pid=%lu, pFile=%p, rc=SQLITE_OK\n",

  45131.            osGetCurrentProcessId(), pFd));

  45132.   return SQLITE_OK;

  45133. }

  45134. #endif /* SQLITE_MAX_MMAP_SIZE>0 */

  45135. 

  45136. /*

  45137. ** If possible, return a pointer to a mapping of file fd starting at offset

  45138. ** iOff. The mapping must be valid for at least nAmt bytes.

  45139. **

  45140. ** If such a pointer can be obtained, store it in *pp and return SQLITE_OK.

  45141. ** Or, if one cannot but no error occurs, set *pp to 0 and return SQLITE_OK.

  45142. ** Finally, if an error does occur, return an SQLite error code. The final

  45143. ** value of *pp is undefined in this case.

  45144. **

  45145. ** If this function does return a pointer, the caller must eventually

  45146. ** release the reference by calling winUnfetch().

  45147. */

  45148. static int winFetch(sqlite3_file *fd, i64 iOff, int nAmt, void **pp){

  45149. #if SQLITE_MAX_MMAP_SIZE>0

  45150.   winFile *pFd = (winFile*)fd;   /* The underlying database file */

  45151. #endif

  45152.   *pp = 0;

  45153. 

  45154.   OSTRACE(("FETCH pid=%lu, pFile=%p, offset=%lld, amount=%d, pp=%p\n",

  45155.            osGetCurrentProcessId(), fd, iOff, nAmt, pp));

  45156. 

  45157. #if SQLITE_MAX_MMAP_SIZE>0

  45158.   if( pFd->mmapSizeMax>0 ){

  45159.     if( pFd->pMapRegion==0 ){

  45160.       int rc = winMapfile(pFd, -1);

  45161.       if( rc!=SQLITE_OK ){

  45162.         OSTRACE(("FETCH pid=%lu, pFile=%p, rc=%s\n",

  45163.                  osGetCurrentProcessId(), pFd, sqlite3ErrName(rc)));

  45164.         return rc;

  45165.       }

  45166.     }

  45167.     if( pFd->mmapSize >= iOff+nAmt ){

  45168.       *pp = &((u8 *)pFd->pMapRegion)[iOff];

  45169.       pFd->nFetchOut++;

  45170.     }

  45171.   }

  45172. #endif

  45173. 

  45174.   OSTRACE(("FETCH pid=%lu, pFile=%p, pp=%p, *pp=%p, rc=SQLITE_OK\n",

  45175.            osGetCurrentProcessId(), fd, pp, *pp));

  45176.   return SQLITE_OK;

  45177. }

  45178. 

  45179. /*

  45180. ** If the third argument is non-NULL, then this function releases a

  45181. ** reference obtained by an earlier call to winFetch(). The second

  45182. ** argument passed to this function must be the same as the corresponding

  45183. ** argument that was passed to the winFetch() invocation.

  45184. **

  45185. ** Or, if the third argument is NULL, then this function is being called

  45186. ** to inform the VFS layer that, according to POSIX, any existing mapping

  45187. ** may now be invalid and should be unmapped.

  45188. */

  45189. static int winUnfetch(sqlite3_file *fd, i64 iOff, void *p){

  45190. #if SQLITE_MAX_MMAP_SIZE>0

  45191.   winFile *pFd = (winFile*)fd;   /* The underlying database file */

  45192. 

  45193.   /* If p==0 (unmap the entire file) then there must be no outstanding

  45194.   ** xFetch references. Or, if p!=0 (meaning it is an xFetch reference),

  45195.   ** then there must be at least one outstanding.  */

  45196.   assert( (p==0)==(pFd->nFetchOut==0) );

  45197. 

  45198.   /* If p!=0, it must match the iOff value. */

  45199.   assert( p==0 || p==&((u8 *)pFd->pMapRegion)[iOff] );

  45200. 

  45201.   OSTRACE(("UNFETCH pid=%lu, pFile=%p, offset=%lld, p=%p\n",

  45202.            osGetCurrentProcessId(), pFd, iOff, p));

  45203. 

  45204.   if( p ){

  45205.     pFd->nFetchOut--;

  45206.   }else{

  45207.     /* FIXME:  If Windows truly always prevents truncating or deleting a

  45208.     ** file while a mapping is held, then the following winUnmapfile() call

  45209.     ** is unnecessary can be omitted - potentially improving

  45210.     ** performance.  */

  45211.     winUnmapfile(pFd);

  45212.   }

  45213. 

  45214.   assert( pFd->nFetchOut>=0 );

  45215. #endif

  45216. 

  45217.   OSTRACE(("UNFETCH pid=%lu, pFile=%p, rc=SQLITE_OK\n",

  45218.            osGetCurrentProcessId(), fd));

  45219.   return SQLITE_OK;

  45220. }

  45221. 

  45222. /*

  45223. ** Here ends the implementation of all sqlite3_file methods.

  45224. **

  45225. ********************** End sqlite3_file Methods *******************************

  45226. ******************************************************************************/

  45227. 

  45228. /*

  45229. ** This vector defines all the methods that can operate on an

  45230. ** sqlite3_file for win32.

  45231. */

  45232. static const sqlite3_io_methods winIoMethod = {

  45233.   3,                              /* iVersion */

  45234.   winClose,                       /* xClose */

  45235.   winRead,                        /* xRead */

  45236.   winWrite,                       /* xWrite */

  45237.   winTruncate,                    /* xTruncate */

  45238.   winSync,                        /* xSync */

  45239.   winFileSize,                    /* xFileSize */

  45240.   winLock,                        /* xLock */

  45241.   winUnlock,                      /* xUnlock */

  45242.   winCheckReservedLock,           /* xCheckReservedLock */

  45243.   winFileControl,                 /* xFileControl */

  45244.   winSectorSize,                  /* xSectorSize */

  45245.   winDeviceCharacteristics,       /* xDeviceCharacteristics */

  45246.   winShmMap,                      /* xShmMap */

  45247.   winShmLock,                     /* xShmLock */

  45248.   winShmBarrier,                  /* xShmBarrier */

  45249.   winShmUnmap,                    /* xShmUnmap */

  45250.   winFetch,                       /* xFetch */

  45251.   winUnfetch                      /* xUnfetch */

  45252. };

  45253. 

  45254. /*

  45255. ** This vector defines all the methods that can operate on an

  45256. ** sqlite3_file for win32 without performing any locking.

  45257. */

  45258. static const sqlite3_io_methods winIoNolockMethod = {

  45259.   3,                              /* iVersion */

  45260.   winClose,                       /* xClose */

  45261.   winRead,                        /* xRead */

  45262.   winWrite,                       /* xWrite */

  45263.   winTruncate,                    /* xTruncate */

  45264.   winSync,                        /* xSync */

  45265.   winFileSize,                    /* xFileSize */

  45266.   winNolockLock,                  /* xLock */

  45267.   winNolockUnlock,                /* xUnlock */

  45268.   winNolockCheckReservedLock,     /* xCheckReservedLock */

  45269.   winFileControl,                 /* xFileControl */

  45270.   winSectorSize,                  /* xSectorSize */

  45271.   winDeviceCharacteristics,       /* xDeviceCharacteristics */

  45272.   winShmMap,                      /* xShmMap */

  45273.   winShmLock,                     /* xShmLock */

  45274.   winShmBarrier,                  /* xShmBarrier */

  45275.   winShmUnmap,                    /* xShmUnmap */

  45276.   winFetch,                       /* xFetch */

  45277.   winUnfetch                      /* xUnfetch */

  45278. };

  45279. 

  45280. static winVfsAppData winAppData = {

  45281.   &winIoMethod,       /* pMethod */

  45282.   0,                  /* pAppData */

  45283.   0                   /* bNoLock */

  45284. };

  45285. 

  45286. static winVfsAppData winNolockAppData = {

  45287.   &winIoNolockMethod, /* pMethod */

  45288.   0,                  /* pAppData */

  45289.   1                   /* bNoLock */

  45290. };

  45291. 

  45292. /****************************************************************************

  45293. **************************** sqlite3_vfs methods ****************************

  45294. **

  45295. ** This division contains the implementation of methods on the

  45296. ** sqlite3_vfs object.

  45297. */

  45298. 

  45299. #if defined(__CYGWIN__)

  45300. /*

  45301. ** Convert a filename from whatever the underlying operating system

  45302. ** supports for filenames into UTF-8.  Space to hold the result is

  45303. ** obtained from malloc and must be freed by the calling function.

  45304. */

  45305. static char *winConvertToUtf8Filename(const void *zFilename){

  45306.   char *zConverted = 0;

  45307.   if( osIsNT() ){

  45308.     zConverted = winUnicodeToUtf8(zFilename);

  45309.   }

  45310. #ifdef SQLITE_WIN32_HAS_ANSI

  45311.   else{

  45312.     zConverted = winMbcsToUtf8(zFilename, osAreFileApisANSI());

  45313.   }

  45314. #endif

  45315.   /* caller will handle out of memory */

  45316.   return zConverted;

  45317. }

  45318. #endif

  45319. 

  45320. /*

  45321. ** Convert a UTF-8 filename into whatever form the underlying

  45322. ** operating system wants filenames in.  Space to hold the result

  45323. ** is obtained from malloc and must be freed by the calling

  45324. ** function.

  45325. */

  45326. static void *winConvertFromUtf8Filename(const char *zFilename){

  45327.   void *zConverted = 0;

  45328.   if( osIsNT() ){

  45329.     zConverted = winUtf8ToUnicode(zFilename);

  45330.   }

  45331. #ifdef SQLITE_WIN32_HAS_ANSI

  45332.   else{

  45333.     zConverted = winUtf8ToMbcs(zFilename, osAreFileApisANSI());

  45334.   }

  45335. #endif

  45336.   /* caller will handle out of memory */

  45337.   return zConverted;

  45338. }

  45339. 

  45340. /*

  45341. ** This function returns non-zero if the specified UTF-8 string buffer

  45342. ** ends with a directory separator character or one was successfully

  45343. ** added to it.

  45344. */

  45345. static int winMakeEndInDirSep(int nBuf, char *zBuf){

  45346.   if( zBuf ){

  45347.     int nLen = sqlite3Strlen30(zBuf);

  45348.     if( nLen>0 ){

  45349.       if( winIsDirSep(zBuf[nLen-1]) ){

  45350.         return 1;

  45351.       }else if( nLen+1<nBuf ){

  45352.         zBuf[nLen] = winGetDirSep();

  45353.         zBuf[nLen+1] = '\0';

  45354.         return 1;

  45355.       }

  45356.     }

  45357.   }

  45358.   return 0;

  45359. }

  45360. 

  45361. /*

  45362. ** Create a temporary file name and store the resulting pointer into pzBuf.

  45363. ** The pointer returned in pzBuf must be freed via sqlite3_free().

  45364. */

  45365. static int winGetTempname(sqlite3_vfs *pVfs, char **pzBuf){

  45366.   static char zChars[] =

  45367.     "abcdefghijklmnopqrstuvwxyz"

  45368.     "ABCDEFGHIJKLMNOPQRSTUVWXYZ"

  45369.     "0123456789";

  45370.   size_t i, j;

  45371.   int nPre = sqlite3Strlen30(SQLITE_TEMP_FILE_PREFIX);

  45372.   int nMax, nBuf, nDir, nLen;

  45373.   char *zBuf;

  45374. 

  45375.   /* It's odd to simulate an io-error here, but really this is just

  45376.   ** using the io-error infrastructure to test that SQLite handles this

  45377.   ** function failing.

  45378.   */

  45379.   SimulateIOError( return SQLITE_IOERR );

  45380. 

  45381.   /* Allocate a temporary buffer to store the fully qualified file

  45382.   ** name for the temporary file.  If this fails, we cannot continue.

  45383.   */

  45384.   nMax = pVfs->mxPathname; nBuf = nMax + 2;

  45385.   zBuf = sqlite3MallocZero( nBuf );

  45386.   if( !zBuf ){

  45387.     OSTRACE(("TEMP-FILENAME rc=SQLITE_IOERR_NOMEM\n"));

  45388.     return SQLITE_IOERR_NOMEM_BKPT;

  45389.   }

  45390. 

  45391.   /* Figure out the effective temporary directory.  First, check if one

  45392.   ** has been explicitly set by the application; otherwise, use the one

  45393.   ** configured by the operating system.

  45394.   */

  45395.   nDir = nMax - (nPre + 15);

  45396.   assert( nDir>0 );

  45397.   if( sqlite3_temp_directory ){

  45398.     int nDirLen = sqlite3Strlen30(sqlite3_temp_directory);

  45399.     if( nDirLen>0 ){

  45400.       if( !winIsDirSep(sqlite3_temp_directory[nDirLen-1]) ){

  45401.         nDirLen++;

  45402.       }

  45403.       if( nDirLen>nDir ){

  45404.         sqlite3_free(zBuf);

  45405.         OSTRACE(("TEMP-FILENAME rc=SQLITE_ERROR\n"));

  45406.         return winLogError(SQLITE_ERROR, 0, "winGetTempname1", 0);

  45407.       }

  45408.       sqlite3_snprintf(nMax, zBuf, "%s", sqlite3_temp_directory);

  45409.     }

  45410.   }

  45411. #if defined(__CYGWIN__)

  45412.   else{

  45413.     static const char *azDirs[] = {

  45414.        0, /* getenv("SQLITE_TMPDIR") */

  45415.        0, /* getenv("TMPDIR") */

  45416.        0, /* getenv("TMP") */

  45417.        0, /* getenv("TEMP") */

  45418.        0, /* getenv("USERPROFILE") */

  45419.        "/var/tmp",

  45420.        "/usr/tmp",

  45421.        "/tmp",

  45422.        ".",

  45423.        0        /* List terminator */

  45424.     };

  45425.     unsigned int i;

  45426.     const char *zDir = 0;

  45427. 

  45428.     if( !azDirs[0] ) azDirs[0] = getenv("SQLITE_TMPDIR");

  45429.     if( !azDirs[1] ) azDirs[1] = getenv("TMPDIR");

  45430.     if( !azDirs[2] ) azDirs[2] = getenv("TMP");

  45431.     if( !azDirs[3] ) azDirs[3] = getenv("TEMP");

  45432.     if( !azDirs[4] ) azDirs[4] = getenv("USERPROFILE");

  45433.     for(i=0; i<sizeof(azDirs)/sizeof(azDirs[0]); zDir=azDirs[i++]){

  45434.       void *zConverted;

  45435.       if( zDir==0 ) continue;

  45436.       /* If the path starts with a drive letter followed by the colon

  45437.       ** character, assume it is already a native Win32 path; otherwise,

  45438.       ** it must be converted to a native Win32 path via the Cygwin API

  45439.       ** prior to using it.

  45440.       */

  45441.       if( winIsDriveLetterAndColon(zDir) ){

  45442.         zConverted = winConvertFromUtf8Filename(zDir);

  45443.         if( !zConverted ){

  45444.           sqlite3_free(zBuf);

  45445.           OSTRACE(("TEMP-FILENAME rc=SQLITE_IOERR_NOMEM\n"));

  45446.           return SQLITE_IOERR_NOMEM_BKPT;

  45447.         }

  45448.         if( winIsDir(zConverted) ){

  45449.           sqlite3_snprintf(nMax, zBuf, "%s", zDir);

  45450.           sqlite3_free(zConverted);

  45451.           break;

  45452.         }

  45453.         sqlite3_free(zConverted);

  45454.       }else{

  45455.         zConverted = sqlite3MallocZero( nMax+1 );

  45456.         if( !zConverted ){

  45457.           sqlite3_free(zBuf);

  45458.           OSTRACE(("TEMP-FILENAME rc=SQLITE_IOERR_NOMEM\n"));

  45459.           return SQLITE_IOERR_NOMEM_BKPT;

  45460.         }

  45461.         if( cygwin_conv_path(

  45462.                 osIsNT() ? CCP_POSIX_TO_WIN_W : CCP_POSIX_TO_WIN_A, zDir,

  45463.                 zConverted, nMax+1)<0 ){

  45464.           sqlite3_free(zConverted);

  45465.           sqlite3_free(zBuf);

  45466.           OSTRACE(("TEMP-FILENAME rc=SQLITE_IOERR_CONVPATH\n"));

  45467.           return winLogError(SQLITE_IOERR_CONVPATH, (DWORD)errno,

  45468.                              "winGetTempname2", zDir);

  45469.         }

  45470.         if( winIsDir(zConverted) ){

  45471.           /* At this point, we know the candidate directory exists and should

  45472.           ** be used.  However, we may need to convert the string containing

  45473.           ** its name into UTF-8 (i.e. if it is UTF-16 right now).

  45474.           */

  45475.           char *zUtf8 = winConvertToUtf8Filename(zConverted);

  45476.           if( !zUtf8 ){

  45477.             sqlite3_free(zConverted);

  45478.             sqlite3_free(zBuf);

  45479.             OSTRACE(("TEMP-FILENAME rc=SQLITE_IOERR_NOMEM\n"));

  45480.             return SQLITE_IOERR_NOMEM_BKPT;

  45481.           }

  45482.           sqlite3_snprintf(nMax, zBuf, "%s", zUtf8);

  45483.           sqlite3_free(zUtf8);

  45484.           sqlite3_free(zConverted);

  45485.           break;

  45486.         }

  45487.         sqlite3_free(zConverted);

  45488.       }

  45489.     }

  45490.   }

  45491. #elif !SQLITE_OS_WINRT && !defined(__CYGWIN__)

  45492.   else if( osIsNT() ){

  45493.     char *zMulti;

  45494.     LPWSTR zWidePath = sqlite3MallocZero( nMax*sizeof(WCHAR) );

  45495.     if( !zWidePath ){

  45496.       sqlite3_free(zBuf);

  45497.       OSTRACE(("TEMP-FILENAME rc=SQLITE_IOERR_NOMEM\n"));

  45498.       return SQLITE_IOERR_NOMEM_BKPT;

  45499.     }

  45500.     if( osGetTempPathW(nMax, zWidePath)==0 ){

  45501.       sqlite3_free(zWidePath);

  45502.       sqlite3_free(zBuf);

  45503.       OSTRACE(("TEMP-FILENAME rc=SQLITE_IOERR_GETTEMPPATH\n"));

  45504.       return winLogError(SQLITE_IOERR_GETTEMPPATH, osGetLastError(),

  45505.                          "winGetTempname2", 0);

  45506.     }

  45507.     zMulti = winUnicodeToUtf8(zWidePath);

  45508.     if( zMulti ){

  45509.       sqlite3_snprintf(nMax, zBuf, "%s", zMulti);

  45510.       sqlite3_free(zMulti);

  45511.       sqlite3_free(zWidePath);

  45512.     }else{

  45513.       sqlite3_free(zWidePath);

  45514.       sqlite3_free(zBuf);

  45515.       OSTRACE(("TEMP-FILENAME rc=SQLITE_IOERR_NOMEM\n"));

  45516.       return SQLITE_IOERR_NOMEM_BKPT;

  45517.     }

  45518.   }

  45519. #ifdef SQLITE_WIN32_HAS_ANSI

  45520.   else{

  45521.     char *zUtf8;

  45522.     char *zMbcsPath = sqlite3MallocZero( nMax );

  45523.     if( !zMbcsPath ){

  45524.       sqlite3_free(zBuf);

  45525.       OSTRACE(("TEMP-FILENAME rc=SQLITE_IOERR_NOMEM\n"));

  45526.       return SQLITE_IOERR_NOMEM_BKPT;

  45527.     }

  45528.     if( osGetTempPathA(nMax, zMbcsPath)==0 ){

  45529.       sqlite3_free(zBuf);

  45530.       OSTRACE(("TEMP-FILENAME rc=SQLITE_IOERR_GETTEMPPATH\n"));

  45531.       return winLogError(SQLITE_IOERR_GETTEMPPATH, osGetLastError(),

  45532.                          "winGetTempname3", 0);

  45533.     }

  45534.     zUtf8 = winMbcsToUtf8(zMbcsPath, osAreFileApisANSI());

  45535.     if( zUtf8 ){

  45536.       sqlite3_snprintf(nMax, zBuf, "%s", zUtf8);

  45537.       sqlite3_free(zUtf8);

  45538.     }else{

  45539.       sqlite3_free(zBuf);

  45540.       OSTRACE(("TEMP-FILENAME rc=SQLITE_IOERR_NOMEM\n"));

  45541.       return SQLITE_IOERR_NOMEM_BKPT;

  45542.     }

  45543.   }

  45544. #endif /* SQLITE_WIN32_HAS_ANSI */

  45545. #endif /* !SQLITE_OS_WINRT */

  45546. 

  45547.   /*

  45548.   ** Check to make sure the temporary directory ends with an appropriate

  45549.   ** separator.  If it does not and there is not enough space left to add

  45550.   ** one, fail.

  45551.   */

  45552.   if( !winMakeEndInDirSep(nDir+1, zBuf) ){

  45553.     sqlite3_free(zBuf);

  45554.     OSTRACE(("TEMP-FILENAME rc=SQLITE_ERROR\n"));

  45555.     return winLogError(SQLITE_ERROR, 0, "winGetTempname4", 0);

  45556.   }

  45557. 

  45558.   /*

  45559.   ** Check that the output buffer is large enough for the temporary file

  45560.   ** name in the following format:

  45561.   **

  45562.   **   "<temporary_directory>/etilqs_XXXXXXXXXXXXXXX\0\0"

  45563.   **

  45564.   ** If not, return SQLITE_ERROR.  The number 17 is used here in order to

  45565.   ** account for the space used by the 15 character random suffix and the

  45566.   ** two trailing NUL characters.  The final directory separator character

  45567.   ** has already added if it was not already present.

  45568.   */

  45569.   nLen = sqlite3Strlen30(zBuf);

  45570.   if( (nLen + nPre + 17) > nBuf ){

  45571.     sqlite3_free(zBuf);

  45572.     OSTRACE(("TEMP-FILENAME rc=SQLITE_ERROR\n"));

  45573.     return winLogError(SQLITE_ERROR, 0, "winGetTempname5", 0);

  45574.   }

  45575. 

  45576.   sqlite3_snprintf(nBuf-16-nLen, zBuf+nLen, SQLITE_TEMP_FILE_PREFIX);

  45577. 

  45578.   j = sqlite3Strlen30(zBuf);

  45579.   sqlite3_randomness(15, &zBuf[j]);

  45580.   for(i=0; i<15; i++, j++){

  45581.     zBuf[j] = (char)zChars[ ((unsigned char)zBuf[j])%(sizeof(zChars)-1) ];

  45582.   }

  45583.   zBuf[j] = 0;

  45584.   zBuf[j+1] = 0;

  45585.   *pzBuf = zBuf;

  45586. 

  45587.   OSTRACE(("TEMP-FILENAME name=%s, rc=SQLITE_OK\n", zBuf));

  45588.   return SQLITE_OK;

  45589. }

  45590. 

  45591. /*

  45592. ** Return TRUE if the named file is really a directory.  Return false if

  45593. ** it is something other than a directory, or if there is any kind of memory

  45594. ** allocation failure.

  45595. */

  45596. static int winIsDir(const void *zConverted){

  45597.   DWORD attr;

  45598.   int rc = 0;

  45599.   DWORD lastErrno;

  45600. 

  45601.   if( osIsNT() ){

  45602.     int cnt = 0;

  45603.     WIN32_FILE_ATTRIBUTE_DATA sAttrData;

  45604.     memset(&sAttrData, 0, sizeof(sAttrData));

  45605.     while( !(rc = osGetFileAttributesExW((LPCWSTR)zConverted,

  45606.                              GetFileExInfoStandard,

  45607.                              &sAttrData)) && winRetryIoerr(&cnt, &lastErrno) ){}

  45608.     if( !rc ){

  45609.       return 0; /* Invalid name? */

  45610.     }

  45611.     attr = sAttrData.dwFileAttributes;

  45612. #if SQLITE_OS_WINCE==0

  45613.   }else{

  45614.     attr = osGetFileAttributesA((char*)zConverted);

  45615. #endif

  45616.   }

  45617.   return (attr!=INVALID_FILE_ATTRIBUTES) && (attr&FILE_ATTRIBUTE_DIRECTORY);

  45618. }

  45619. 

  45620. /* forward reference */

  45621. static int winAccess(

  45622.   sqlite3_vfs *pVfs,         /* Not used on win32 */

  45623.   const char *zFilename,     /* Name of file to check */

  45624.   int flags,                 /* Type of test to make on this file */

  45625.   int *pResOut               /* OUT: Result */

  45626. );

  45627. 

  45628. /*

  45629. ** Open a file.

  45630. */

  45631. static int winOpen(

  45632.   sqlite3_vfs *pVfs,        /* Used to get maximum path length and AppData */

  45633.   const char *zName,        /* Name of the file (UTF-8) */

  45634.   sqlite3_file *id,         /* Write the SQLite file handle here */

  45635.   int flags,                /* Open mode flags */

  45636.   int *pOutFlags            /* Status return flags */

  45637. ){

  45638.   HANDLE h;

  45639.   DWORD lastErrno = 0;

  45640.   DWORD dwDesiredAccess;

  45641.   DWORD dwShareMode;

  45642.   DWORD dwCreationDisposition;

  45643.   DWORD dwFlagsAndAttributes = 0;

  45644. #if SQLITE_OS_WINCE

  45645.   int isTemp = 0;

  45646. #endif

  45647.   winVfsAppData *pAppData;

  45648.   winFile *pFile = (winFile*)id;

  45649.   void *zConverted;              /* Filename in OS encoding */

  45650.   const char *zUtf8Name = zName; /* Filename in UTF-8 encoding */

  45651.   int cnt = 0;

  45652. 

  45653.   /* If argument zPath is a NULL pointer, this function is required to open

  45654.   ** a temporary file. Use this buffer to store the file name in.

  45655.   */

  45656.   char *zTmpname = 0; /* For temporary filename, if necessary. */

  45657. 

  45658.   int rc = SQLITE_OK;            /* Function Return Code */

  45659. #if !defined(NDEBUG) || SQLITE_OS_WINCE

  45660.   int eType = flags&0xFFFFFF00;  /* Type of file to open */

  45661. #endif

  45662. 

  45663.   int isExclusive  = (flags & SQLITE_OPEN_EXCLUSIVE);

  45664.   int isDelete     = (flags & SQLITE_OPEN_DELETEONCLOSE);

  45665.   int isCreate     = (flags & SQLITE_OPEN_CREATE);

  45666.   int isReadonly   = (flags & SQLITE_OPEN_READONLY);

  45667.   int isReadWrite  = (flags & SQLITE_OPEN_READWRITE);

  45668. 

  45669. #ifndef NDEBUG

  45670.   int isOpenJournal = (isCreate && (

  45671.         eType==SQLITE_OPEN_MASTER_JOURNAL

  45672.      || eType==SQLITE_OPEN_MAIN_JOURNAL

  45673.      || eType==SQLITE_OPEN_WAL

  45674.   ));

  45675. #endif

  45676. 

  45677.   OSTRACE(("OPEN name=%s, pFile=%p, flags=%x, pOutFlags=%p\n",

  45678.            zUtf8Name, id, flags, pOutFlags));

  45679. 

  45680.   /* Check the following statements are true:

  45681.   **

  45682.   **   (a) Exactly one of the READWRITE and READONLY flags must be set, and

  45683.   **   (b) if CREATE is set, then READWRITE must also be set, and

  45684.   **   (c) if EXCLUSIVE is set, then CREATE must also be set.

  45685.   **   (d) if DELETEONCLOSE is set, then CREATE must also be set.

  45686.   */

  45687.   assert((isReadonly==0 || isReadWrite==0) && (isReadWrite || isReadonly));

  45688.   assert(isCreate==0 || isReadWrite);

  45689.   assert(isExclusive==0 || isCreate);

  45690.   assert(isDelete==0 || isCreate);

  45691. 

  45692.   /* The main DB, main journal, WAL file and master journal are never

  45693.   ** automatically deleted. Nor are they ever temporary files.  */

  45694.   assert( (!isDelete && zName) || eType!=SQLITE_OPEN_MAIN_DB );

  45695.   assert( (!isDelete && zName) || eType!=SQLITE_OPEN_MAIN_JOURNAL );

  45696.   assert( (!isDelete && zName) || eType!=SQLITE_OPEN_MASTER_JOURNAL );

  45697.   assert( (!isDelete && zName) || eType!=SQLITE_OPEN_WAL );

  45698. 

  45699.   /* Assert that the upper layer has set one of the "file-type" flags. */

  45700.   assert( eType==SQLITE_OPEN_MAIN_DB      || eType==SQLITE_OPEN_TEMP_DB

  45701.        || eType==SQLITE_OPEN_MAIN_JOURNAL || eType==SQLITE_OPEN_TEMP_JOURNAL

  45702.        || eType==SQLITE_OPEN_SUBJOURNAL   || eType==SQLITE_OPEN_MASTER_JOURNAL

  45703.        || eType==SQLITE_OPEN_TRANSIENT_DB || eType==SQLITE_OPEN_WAL

  45704.   );

  45705. 

  45706.   assert( pFile!=0 );

  45707.   memset(pFile, 0, sizeof(winFile));

  45708.   pFile->h = INVALID_HANDLE_VALUE;

  45709. 

  45710. #if SQLITE_OS_WINRT

  45711.   if( !zUtf8Name && !sqlite3_temp_directory ){

  45712.     sqlite3_log(SQLITE_ERROR,

  45713.         "sqlite3_temp_directory variable should be set for WinRT");

  45714.   }

  45715. #endif

  45716. 

  45717.   /* If the second argument to this function is NULL, generate a

  45718.   ** temporary file name to use

  45719.   */

  45720.   if( !zUtf8Name ){

  45721.     assert( isDelete && !isOpenJournal );

  45722.     rc = winGetTempname(pVfs, &zTmpname);

  45723.     if( rc!=SQLITE_OK ){

  45724.       OSTRACE(("OPEN name=%s, rc=%s", zUtf8Name, sqlite3ErrName(rc)));

  45725.       return rc;

  45726.     }

  45727.     zUtf8Name = zTmpname;

  45728.   }

  45729. 

  45730.   /* Database filenames are double-zero terminated if they are not

  45731.   ** URIs with parameters.  Hence, they can always be passed into

  45732.   ** sqlite3_uri_parameter().

  45733.   */

  45734.   assert( (eType!=SQLITE_OPEN_MAIN_DB) || (flags & SQLITE_OPEN_URI) ||

  45735.        zUtf8Name[sqlite3Strlen30(zUtf8Name)+1]==0 );

  45736. 

  45737.   /* Convert the filename to the system encoding. */

  45738.   zConverted = winConvertFromUtf8Filename(zUtf8Name);

  45739.   if( zConverted==0 ){

  45740.     sqlite3_free(zTmpname);

  45741.     OSTRACE(("OPEN name=%s, rc=SQLITE_IOERR_NOMEM", zUtf8Name));

  45742.     return SQLITE_IOERR_NOMEM_BKPT;

  45743.   }

  45744. 

  45745.   if( winIsDir(zConverted) ){

  45746.     sqlite3_free(zConverted);

  45747.     sqlite3_free(zTmpname);

  45748.     OSTRACE(("OPEN name=%s, rc=SQLITE_CANTOPEN_ISDIR", zUtf8Name));

  45749.     return SQLITE_CANTOPEN_ISDIR;

  45750.   }

  45751. 

  45752.   if( isReadWrite ){

  45753.     dwDesiredAccess = GENERIC_READ | GENERIC_WRITE;

  45754.   }else{

  45755.     dwDesiredAccess = GENERIC_READ;

  45756.   }

  45757. 

  45758.   /* SQLITE_OPEN_EXCLUSIVE is used to make sure that a new file is

  45759.   ** created. SQLite doesn't use it to indicate "exclusive access"

  45760.   ** as it is usually understood.

  45761.   */

  45762.   if( isExclusive ){

  45763.     /* Creates a new file, only if it does not already exist. */

  45764.     /* If the file exists, it fails. */

  45765.     dwCreationDisposition = CREATE_NEW;

  45766.   }else if( isCreate ){

  45767.     /* Open existing file, or create if it doesn't exist */

  45768.     dwCreationDisposition = OPEN_ALWAYS;

  45769.   }else{

  45770.     /* Opens a file, only if it exists. */

  45771.     dwCreationDisposition = OPEN_EXISTING;

  45772.   }

  45773. 

  45774.   dwShareMode = FILE_SHARE_READ | FILE_SHARE_WRITE;

  45775. 

  45776.   if( isDelete ){

  45777. #if SQLITE_OS_WINCE

  45778.     dwFlagsAndAttributes = FILE_ATTRIBUTE_HIDDEN;

  45779.     isTemp = 1;

  45780. #else

  45781.     dwFlagsAndAttributes = FILE_ATTRIBUTE_TEMPORARY

  45782.                                | FILE_ATTRIBUTE_HIDDEN

  45783.                                | FILE_FLAG_DELETE_ON_CLOSE;

  45784. #endif

  45785.   }else{

  45786.     dwFlagsAndAttributes = FILE_ATTRIBUTE_NORMAL;

  45787.   }

  45788.   /* Reports from the internet are that performance is always

  45789.   ** better if FILE_FLAG_RANDOM_ACCESS is used.  Ticket #2699. */

  45790. #if SQLITE_OS_WINCE

  45791.   dwFlagsAndAttributes |= FILE_FLAG_RANDOM_ACCESS;

  45792. #endif

  45793. 

  45794.   if( osIsNT() ){

  45795. #if SQLITE_OS_WINRT

  45796.     CREATEFILE2_EXTENDED_PARAMETERS extendedParameters;

  45797.     extendedParameters.dwSize = sizeof(CREATEFILE2_EXTENDED_PARAMETERS);

  45798.     extendedParameters.dwFileAttributes =

  45799.             dwFlagsAndAttributes & FILE_ATTRIBUTE_MASK;

  45800.     extendedParameters.dwFileFlags = dwFlagsAndAttributes & FILE_FLAG_MASK;

  45801.     extendedParameters.dwSecurityQosFlags = SECURITY_ANONYMOUS;

  45802.     extendedParameters.lpSecurityAttributes = NULL;

  45803.     extendedParameters.hTemplateFile = NULL;

  45804.     do{

  45805.       h = osCreateFile2((LPCWSTR)zConverted,

  45806.                         dwDesiredAccess,

  45807.                         dwShareMode,

  45808.                         dwCreationDisposition,

  45809.                         &extendedParameters);

  45810.       if( h!=INVALID_HANDLE_VALUE ) break;

  45811.       if( isReadWrite ){

  45812.         int rc2, isRO = 0;

  45813.         sqlite3BeginBenignMalloc();

  45814.         rc2 = winAccess(pVfs, zName, SQLITE_ACCESS_READ, &isRO);

  45815.         sqlite3EndBenignMalloc();

  45816.         if( rc2==SQLITE_OK && isRO ) break;

  45817.       }

  45818.     }while( winRetryIoerr(&cnt, &lastErrno) );

  45819. #else

  45820.     do{

  45821.       h = osCreateFileW((LPCWSTR)zConverted,

  45822.                         dwDesiredAccess,

  45823.                         dwShareMode, NULL,

  45824.                         dwCreationDisposition,

  45825.                         dwFlagsAndAttributes,

  45826.                         NULL);

  45827.       if( h!=INVALID_HANDLE_VALUE ) break;

  45828.       if( isReadWrite ){

  45829.         int rc2, isRO = 0;

  45830.         sqlite3BeginBenignMalloc();

  45831.         rc2 = winAccess(pVfs, zName, SQLITE_ACCESS_READ, &isRO);

  45832.         sqlite3EndBenignMalloc();

  45833.         if( rc2==SQLITE_OK && isRO ) break;

  45834.       }

  45835.     }while( winRetryIoerr(&cnt, &lastErrno) );

  45836. #endif

  45837.   }

  45838. #ifdef SQLITE_WIN32_HAS_ANSI

  45839.   else{

  45840.     do{

  45841.       h = osCreateFileA((LPCSTR)zConverted,

  45842.                         dwDesiredAccess,

  45843.                         dwShareMode, NULL,

  45844.                         dwCreationDisposition,

  45845.                         dwFlagsAndAttributes,

  45846.                         NULL);

  45847.       if( h!=INVALID_HANDLE_VALUE ) break;

  45848.       if( isReadWrite ){

  45849.         int rc2, isRO = 0;

  45850.         sqlite3BeginBenignMalloc();

  45851.         rc2 = winAccess(pVfs, zName, SQLITE_ACCESS_READ, &isRO);

  45852.         sqlite3EndBenignMalloc();

  45853.         if( rc2==SQLITE_OK && isRO ) break;

  45854.       }

  45855.     }while( winRetryIoerr(&cnt, &lastErrno) );

  45856.   }

  45857. #endif

  45858.   winLogIoerr(cnt, __LINE__);

  45859. 

  45860.   OSTRACE(("OPEN file=%p, name=%s, access=%lx, rc=%s\n", h, zUtf8Name,

  45861.            dwDesiredAccess, (h==INVALID_HANDLE_VALUE) ? "failed" : "ok"));

  45862. 

  45863.   if( h==INVALID_HANDLE_VALUE ){

  45864.     sqlite3_free(zConverted);

  45865.     sqlite3_free(zTmpname);

  45866.     if( isReadWrite && !isExclusive ){

  45867.       return winOpen(pVfs, zName, id,

  45868.          ((flags|SQLITE_OPEN_READONLY) &

  45869.                      ~(SQLITE_OPEN_CREATE|SQLITE_OPEN_READWRITE)),

  45870.          pOutFlags);

  45871.     }else{

  45872.       pFile->lastErrno = lastErrno;

  45873.       winLogError(SQLITE_CANTOPEN, pFile->lastErrno, "winOpen", zUtf8Name);

  45874.       return SQLITE_CANTOPEN_BKPT;

  45875.     }

  45876.   }

  45877. 

  45878.   if( pOutFlags ){

  45879.     if( isReadWrite ){

  45880.       *pOutFlags = SQLITE_OPEN_READWRITE;

  45881.     }else{

  45882.       *pOutFlags = SQLITE_OPEN_READONLY;

  45883.     }

  45884.   }

  45885. 

  45886.   OSTRACE(("OPEN file=%p, name=%s, access=%lx, pOutFlags=%p, *pOutFlags=%d, "

  45887.            "rc=%s\n", h, zUtf8Name, dwDesiredAccess, pOutFlags, pOutFlags ?

  45888.            *pOutFlags : 0, (h==INVALID_HANDLE_VALUE) ? "failed" : "ok"));

  45889. 

  45890.   pAppData = (winVfsAppData*)pVfs->pAppData;

  45891. 

  45892. #if SQLITE_OS_WINCE

  45893.   {

  45894.     if( isReadWrite && eType==SQLITE_OPEN_MAIN_DB

  45895.          && ((pAppData==NULL) || !pAppData->bNoLock)

  45896.          && (rc = winceCreateLock(zName, pFile))!=SQLITE_OK

  45897.     ){

  45898.       osCloseHandle(h);

  45899.       sqlite3_free(zConverted);

  45900.       sqlite3_free(zTmpname);

  45901.       OSTRACE(("OPEN-CE-LOCK name=%s, rc=%s\n", zName, sqlite3ErrName(rc)));

  45902.       return rc;

  45903.     }

  45904.   }

  45905.   if( isTemp ){

  45906.     pFile->zDeleteOnClose = zConverted;

  45907.   }else

  45908. #endif

  45909.   {

  45910.     sqlite3_free(zConverted);

  45911.   }

  45912. 

  45913.   sqlite3_free(zTmpname);

  45914.   pFile->pMethod = pAppData ? pAppData->pMethod : &winIoMethod;

  45915.   pFile->pVfs = pVfs;

  45916.   pFile->h = h;

  45917.   if( isReadonly ){

  45918.     pFile->ctrlFlags |= WINFILE_RDONLY;

  45919.   }

  45920.   if( sqlite3_uri_boolean(zName, "psow", SQLITE_POWERSAFE_OVERWRITE) ){

  45921.     pFile->ctrlFlags |= WINFILE_PSOW;

  45922.   }

  45923.   pFile->lastErrno = NO_ERROR;

  45924.   pFile->zPath = zName;

  45925. #if SQLITE_MAX_MMAP_SIZE>0

  45926.   pFile->hMap = NULL;

  45927.   pFile->pMapRegion = 0;

  45928.   pFile->mmapSize = 0;

  45929.   pFile->mmapSizeMax = sqlite3GlobalConfig.szMmap;

  45930. #endif

  45931. 

  45932.   OpenCounter(+1);

  45933.   return rc;

  45934. }

  45935. 

  45936. /*

  45937. ** Delete the named file.

  45938. **

  45939. ** Note that Windows does not allow a file to be deleted if some other

  45940. ** process has it open.  Sometimes a virus scanner or indexing program

  45941. ** will open a journal file shortly after it is created in order to do

  45942. ** whatever it does.  While this other process is holding the

  45943. ** file open, we will be unable to delete it.  To work around this

  45944. ** problem, we delay 100 milliseconds and try to delete again.  Up

  45945. ** to MX_DELETION_ATTEMPTs deletion attempts are run before giving

  45946. ** up and returning an error.

  45947. */

  45948. static int winDelete(

  45949.   sqlite3_vfs *pVfs,          /* Not used on win32 */

  45950.   const char *zFilename,      /* Name of file to delete */

  45951.   int syncDir                 /* Not used on win32 */

  45952. ){

  45953.   int cnt = 0;

  45954.   int rc;

  45955.   DWORD attr;

  45956.   DWORD lastErrno = 0;

  45957.   void *zConverted;

  45958.   UNUSED_PARAMETER(pVfs);

  45959.   UNUSED_PARAMETER(syncDir);

  45960. 

  45961.   SimulateIOError(return SQLITE_IOERR_DELETE);

  45962.   OSTRACE(("DELETE name=%s, syncDir=%d\n", zFilename, syncDir));

  45963. 

  45964.   zConverted = winConvertFromUtf8Filename(zFilename);

  45965.   if( zConverted==0 ){

  45966.     OSTRACE(("DELETE name=%s, rc=SQLITE_IOERR_NOMEM\n", zFilename));

  45967.     return SQLITE_IOERR_NOMEM_BKPT;

  45968.   }

  45969.   if( osIsNT() ){

  45970.     do {

  45971. #if SQLITE_OS_WINRT

  45972.       WIN32_FILE_ATTRIBUTE_DATA sAttrData;

  45973.       memset(&sAttrData, 0, sizeof(sAttrData));

  45974.       if ( osGetFileAttributesExW(zConverted, GetFileExInfoStandard,

  45975.                                   &sAttrData) ){

  45976.         attr = sAttrData.dwFileAttributes;

  45977.       }else{

  45978.         lastErrno = osGetLastError();

  45979.         if( lastErrno==ERROR_FILE_NOT_FOUND

  45980.          || lastErrno==ERROR_PATH_NOT_FOUND ){

  45981.           rc = SQLITE_IOERR_DELETE_NOENT; /* Already gone? */

  45982.         }else{

  45983.           rc = SQLITE_ERROR;

  45984.         }

  45985.         break;

  45986.       }

  45987. #else

  45988.       attr = osGetFileAttributesW(zConverted);

  45989. #endif

  45990.       if ( attr==INVALID_FILE_ATTRIBUTES ){

  45991.         lastErrno = osGetLastError();

  45992.         if( lastErrno==ERROR_FILE_NOT_FOUND

  45993.          || lastErrno==ERROR_PATH_NOT_FOUND ){

  45994.           rc = SQLITE_IOERR_DELETE_NOENT; /* Already gone? */

  45995.         }else{

  45996.           rc = SQLITE_ERROR;

  45997.         }

  45998.         break;

  45999.       }

  46000.       if ( attr&FILE_ATTRIBUTE_DIRECTORY ){

  46001.         rc = SQLITE_ERROR; /* Files only. */

  46002.         break;

  46003.       }

  46004.       if ( osDeleteFileW(zConverted) ){

  46005.         rc = SQLITE_OK; /* Deleted OK. */

  46006.         break;

  46007.       }

  46008.       if ( !winRetryIoerr(&cnt, &lastErrno) ){

  46009.         rc = SQLITE_ERROR; /* No more retries. */

  46010.         break;

  46011.       }

  46012.     } while(1);

  46013.   }

  46014. #ifdef SQLITE_WIN32_HAS_ANSI

  46015.   else{

  46016.     do {

  46017.       attr = osGetFileAttributesA(zConverted);

  46018.       if ( attr==INVALID_FILE_ATTRIBUTES ){

  46019.         lastErrno = osGetLastError();

  46020.         if( lastErrno==ERROR_FILE_NOT_FOUND

  46021.          || lastErrno==ERROR_PATH_NOT_FOUND ){

  46022.           rc = SQLITE_IOERR_DELETE_NOENT; /* Already gone? */

  46023.         }else{

  46024.           rc = SQLITE_ERROR;

  46025.         }

  46026.         break;

  46027.       }

  46028.       if ( attr&FILE_ATTRIBUTE_DIRECTORY ){

  46029.         rc = SQLITE_ERROR; /* Files only. */

  46030.         break;

  46031.       }

  46032.       if ( osDeleteFileA(zConverted) ){

  46033.         rc = SQLITE_OK; /* Deleted OK. */

  46034.         break;

  46035.       }

  46036.       if ( !winRetryIoerr(&cnt, &lastErrno) ){

  46037.         rc = SQLITE_ERROR; /* No more retries. */

  46038.         break;

  46039.       }

  46040.     } while(1);

  46041.   }

  46042. #endif

  46043.   if( rc && rc!=SQLITE_IOERR_DELETE_NOENT ){

  46044.     rc = winLogError(SQLITE_IOERR_DELETE, lastErrno, "winDelete", zFilename);

  46045.   }else{

  46046.     winLogIoerr(cnt, __LINE__);

  46047.   }

  46048.   sqlite3_free(zConverted);

  46049.   OSTRACE(("DELETE name=%s, rc=%s\n", zFilename, sqlite3ErrName(rc)));

  46050.   return rc;

  46051. }

  46052. 

  46053. /*

  46054. ** Check the existence and status of a file.

  46055. */

  46056. static int winAccess(

  46057.   sqlite3_vfs *pVfs,         /* Not used on win32 */

  46058.   const char *zFilename,     /* Name of file to check */

  46059.   int flags,                 /* Type of test to make on this file */

  46060.   int *pResOut               /* OUT: Result */

  46061. ){

  46062.   DWORD attr;

  46063.   int rc = 0;

  46064.   DWORD lastErrno = 0;

  46065.   void *zConverted;

  46066.   UNUSED_PARAMETER(pVfs);

  46067. 

  46068.   SimulateIOError( return SQLITE_IOERR_ACCESS; );

  46069.   OSTRACE(("ACCESS name=%s, flags=%x, pResOut=%p\n",

  46070.            zFilename, flags, pResOut));

  46071. 

  46072.   zConverted = winConvertFromUtf8Filename(zFilename);

  46073.   if( zConverted==0 ){

  46074.     OSTRACE(("ACCESS name=%s, rc=SQLITE_IOERR_NOMEM\n", zFilename));

  46075.     return SQLITE_IOERR_NOMEM_BKPT;

  46076.   }

  46077.   if( osIsNT() ){

  46078.     int cnt = 0;

  46079.     WIN32_FILE_ATTRIBUTE_DATA sAttrData;

  46080.     memset(&sAttrData, 0, sizeof(sAttrData));

  46081.     while( !(rc = osGetFileAttributesExW((LPCWSTR)zConverted,

  46082.                              GetFileExInfoStandard,

  46083.                              &sAttrData)) && winRetryIoerr(&cnt, &lastErrno) ){}

  46084.     if( rc ){

  46085.       /* For an SQLITE_ACCESS_EXISTS query, treat a zero-length file

  46086.       ** as if it does not exist.

  46087.       */

  46088.       if(    flags==SQLITE_ACCESS_EXISTS

  46089.           && sAttrData.nFileSizeHigh==0

  46090.           && sAttrData.nFileSizeLow==0 ){

  46091.         attr = INVALID_FILE_ATTRIBUTES;

  46092.       }else{

  46093.         attr = sAttrData.dwFileAttributes;

  46094.       }

  46095.     }else{

  46096.       winLogIoerr(cnt, __LINE__);

  46097.       if( lastErrno!=ERROR_FILE_NOT_FOUND && lastErrno!=ERROR_PATH_NOT_FOUND ){

  46098.         sqlite3_free(zConverted);

  46099.         return winLogError(SQLITE_IOERR_ACCESS, lastErrno, "winAccess",

  46100.                            zFilename);

  46101.       }else{

  46102.         attr = INVALID_FILE_ATTRIBUTES;

  46103.       }

  46104.     }

  46105.   }

  46106. #ifdef SQLITE_WIN32_HAS_ANSI

  46107.   else{

  46108.     attr = osGetFileAttributesA((char*)zConverted);

  46109.   }

  46110. #endif

  46111.   sqlite3_free(zConverted);

  46112.   switch( flags ){

  46113.     case SQLITE_ACCESS_READ:

  46114.     case SQLITE_ACCESS_EXISTS:

  46115.       rc = attr!=INVALID_FILE_ATTRIBUTES;

  46116.       break;

  46117.     case SQLITE_ACCESS_READWRITE:

  46118.       rc = attr!=INVALID_FILE_ATTRIBUTES &&

  46119.              (attr & FILE_ATTRIBUTE_READONLY)==0;

  46120.       break;

  46121.     default:

  46122.       assert(!"Invalid flags argument");

  46123.   }

  46124.   *pResOut = rc;

  46125.   OSTRACE(("ACCESS name=%s, pResOut=%p, *pResOut=%d, rc=SQLITE_OK\n",

  46126.            zFilename, pResOut, *pResOut));

  46127.   return SQLITE_OK;

  46128. }

  46129. 

  46130. /*

  46131. ** Returns non-zero if the specified path name starts with a drive letter

  46132. ** followed by a colon character.

  46133. */

  46134. static BOOL winIsDriveLetterAndColon(

  46135.   const char *zPathname

  46136. ){

  46137.   return ( sqlite3Isalpha(zPathname[0]) && zPathname[1]==':' );

  46138. }

  46139. 

  46140. /*

  46141. ** Returns non-zero if the specified path name should be used verbatim.  If

  46142. ** non-zero is returned from this function, the calling function must simply

  46143. ** use the provided path name verbatim -OR- resolve it into a full path name

  46144. ** using the GetFullPathName Win32 API function (if available).

  46145. */

  46146. static BOOL winIsVerbatimPathname(

  46147.   const char *zPathname

  46148. ){

  46149.   /*

  46150.   ** If the path name starts with a forward slash or a backslash, it is either

  46151.   ** a legal UNC name, a volume relative path, or an absolute path name in the

  46152.   ** "Unix" format on Windows.  There is no easy way to differentiate between

  46153.   ** the final two cases; therefore, we return the safer return value of TRUE

  46154.   ** so that callers of this function will simply use it verbatim.

  46155.   */

  46156.   if ( winIsDirSep(zPathname[0]) ){

  46157.     return TRUE;

  46158.   }

  46159. 

  46160.   /*

  46161.   ** If the path name starts with a letter and a colon it is either a volume

  46162.   ** relative path or an absolute path.  Callers of this function must not

  46163.   ** attempt to treat it as a relative path name (i.e. they should simply use

  46164.   ** it verbatim).

  46165.   */

  46166.   if ( winIsDriveLetterAndColon(zPathname) ){

  46167.     return TRUE;

  46168.   }

  46169. 

  46170.   /*

  46171.   ** If we get to this point, the path name should almost certainly be a purely

  46172.   ** relative one (i.e. not a UNC name, not absolute, and not volume relative).

  46173.   */

  46174.   return FALSE;

  46175. }

  46176. 

  46177. /*

  46178. ** Turn a relative pathname into a full pathname.  Write the full

  46179. ** pathname into zOut[].  zOut[] will be at least pVfs->mxPathname

  46180. ** bytes in size.

  46181. */

  46182. static int winFullPathname(

  46183.   sqlite3_vfs *pVfs,            /* Pointer to vfs object */

  46184.   const char *zRelative,        /* Possibly relative input path */

  46185.   int nFull,                    /* Size of output buffer in bytes */

  46186.   char *zFull                   /* Output buffer */

  46187. ){

  46188. #if !SQLITE_OS_WINCE && !SQLITE_OS_WINRT && !defined(__CYGWIN__)

  46189.   DWORD nByte;

  46190.   void *zConverted;

  46191.   char *zOut;

  46192. #endif

  46193. 

  46194.   /* If this path name begins with "/X:", where "X" is any alphabetic

  46195.   ** character, discard the initial "/" from the pathname.

  46196.   */

  46197.   if( zRelative[0]=='/' && winIsDriveLetterAndColon(zRelative+1) ){

  46198.     zRelative++;

  46199.   }

  46200. 

  46201. #if defined(__CYGWIN__)

  46202.   SimulateIOError( return SQLITE_ERROR );

  46203.   UNUSED_PARAMETER(nFull);

  46204.   assert( nFull>=pVfs->mxPathname );

  46205.   if ( sqlite3_data_directory && !winIsVerbatimPathname(zRelative) ){

  46206.     /*

  46207.     ** NOTE: We are dealing with a relative path name and the data

  46208.     **       directory has been set.  Therefore, use it as the basis

  46209.     **       for converting the relative path name to an absolute

  46210.     **       one by prepending the data directory and a slash.

  46211.     */

  46212.     char *zOut = sqlite3MallocZero( pVfs->mxPathname+1 );

  46213.     if( !zOut ){

  46214.       return SQLITE_IOERR_NOMEM_BKPT;

  46215.     }

  46216.     if( cygwin_conv_path(

  46217.             (osIsNT() ? CCP_POSIX_TO_WIN_W : CCP_POSIX_TO_WIN_A) |

  46218.             CCP_RELATIVE, zRelative, zOut, pVfs->mxPathname+1)<0 ){

  46219.       sqlite3_free(zOut);

  46220.       return winLogError(SQLITE_CANTOPEN_CONVPATH, (DWORD)errno,

  46221.                          "winFullPathname1", zRelative);

  46222.     }else{

  46223.       char *zUtf8 = winConvertToUtf8Filename(zOut);

  46224.       if( !zUtf8 ){

  46225.         sqlite3_free(zOut);

  46226.         return SQLITE_IOERR_NOMEM_BKPT;

  46227.       }

  46228.       sqlite3_snprintf(MIN(nFull, pVfs->mxPathname), zFull, "%s%c%s",

  46229.                        sqlite3_data_directory, winGetDirSep(), zUtf8);

  46230.       sqlite3_free(zUtf8);

  46231.       sqlite3_free(zOut);

  46232.     }

  46233.   }else{

  46234.     char *zOut = sqlite3MallocZero( pVfs->mxPathname+1 );

  46235.     if( !zOut ){

  46236.       return SQLITE_IOERR_NOMEM_BKPT;

  46237.     }

  46238.     if( cygwin_conv_path(

  46239.             (osIsNT() ? CCP_POSIX_TO_WIN_W : CCP_POSIX_TO_WIN_A),

  46240.             zRelative, zOut, pVfs->mxPathname+1)<0 ){

  46241.       sqlite3_free(zOut);

  46242.       return winLogError(SQLITE_CANTOPEN_CONVPATH, (DWORD)errno,

  46243.                          "winFullPathname2", zRelative);

  46244.     }else{

  46245.       char *zUtf8 = winConvertToUtf8Filename(zOut);

  46246.       if( !zUtf8 ){

  46247.         sqlite3_free(zOut);

  46248.         return SQLITE_IOERR_NOMEM_BKPT;

  46249.       }

  46250.       sqlite3_snprintf(MIN(nFull, pVfs->mxPathname), zFull, "%s", zUtf8);

  46251.       sqlite3_free(zUtf8);

  46252.       sqlite3_free(zOut);

  46253.     }

  46254.   }

  46255.   return SQLITE_OK;

  46256. #endif

  46257. 

  46258. #if (SQLITE_OS_WINCE || SQLITE_OS_WINRT) && !defined(__CYGWIN__)

  46259.   SimulateIOError( return SQLITE_ERROR );

  46260.   /* WinCE has no concept of a relative pathname, or so I am told. */

  46261.   /* WinRT has no way to convert a relative path to an absolute one. */

  46262.   if ( sqlite3_data_directory && !winIsVerbatimPathname(zRelative) ){

  46263.     /*

  46264.     ** NOTE: We are dealing with a relative path name and the data

  46265.     **       directory has been set.  Therefore, use it as the basis

  46266.     **       for converting the relative path name to an absolute

  46267.     **       one by prepending the data directory and a backslash.

  46268.     */

  46269.     sqlite3_snprintf(MIN(nFull, pVfs->mxPathname), zFull, "%s%c%s",

  46270.                      sqlite3_data_directory, winGetDirSep(), zRelative);

  46271.   }else{

  46272.     sqlite3_snprintf(MIN(nFull, pVfs->mxPathname), zFull, "%s", zRelative);

  46273.   }

  46274.   return SQLITE_OK;

  46275. #endif

  46276. 

  46277. #if !SQLITE_OS_WINCE && !SQLITE_OS_WINRT && !defined(__CYGWIN__)

  46278.   /* It's odd to simulate an io-error here, but really this is just

  46279.   ** using the io-error infrastructure to test that SQLite handles this

  46280.   ** function failing. This function could fail if, for example, the

  46281.   ** current working directory has been unlinked.

  46282.   */

  46283.   SimulateIOError( return SQLITE_ERROR );

  46284.   if ( sqlite3_data_directory && !winIsVerbatimPathname(zRelative) ){

  46285.     /*

  46286.     ** NOTE: We are dealing with a relative path name and the data

  46287.     **       directory has been set.  Therefore, use it as the basis

  46288.     **       for converting the relative path name to an absolute

  46289.     **       one by prepending the data directory and a backslash.

  46290.     */

  46291.     sqlite3_snprintf(MIN(nFull, pVfs->mxPathname), zFull, "%s%c%s",

  46292.                      sqlite3_data_directory, winGetDirSep(), zRelative);

  46293.     return SQLITE_OK;

  46294.   }

  46295.   zConverted = winConvertFromUtf8Filename(zRelative);

  46296.   if( zConverted==0 ){

  46297.     return SQLITE_IOERR_NOMEM_BKPT;

  46298.   }

  46299.   if( osIsNT() ){

  46300.     LPWSTR zTemp;

  46301.     nByte = osGetFullPathNameW((LPCWSTR)zConverted, 0, 0, 0);

  46302.     if( nByte==0 ){

  46303.       sqlite3_free(zConverted);

  46304.       return winLogError(SQLITE_CANTOPEN_FULLPATH, osGetLastError(),

  46305.                          "winFullPathname1", zRelative);

  46306.     }

  46307.     nByte += 3;

  46308.     zTemp = sqlite3MallocZero( nByte*sizeof(zTemp[0]) );

  46309.     if( zTemp==0 ){

  46310.       sqlite3_free(zConverted);

  46311.       return SQLITE_IOERR_NOMEM_BKPT;

  46312.     }

  46313.     nByte = osGetFullPathNameW((LPCWSTR)zConverted, nByte, zTemp, 0);

  46314.     if( nByte==0 ){

  46315.       sqlite3_free(zConverted);

  46316.       sqlite3_free(zTemp);

  46317.       return winLogError(SQLITE_CANTOPEN_FULLPATH, osGetLastError(),

  46318.                          "winFullPathname2", zRelative);

  46319.     }

  46320.     sqlite3_free(zConverted);

  46321.     zOut = winUnicodeToUtf8(zTemp);

  46322.     sqlite3_free(zTemp);

  46323.   }

  46324. #ifdef SQLITE_WIN32_HAS_ANSI

  46325.   else{

  46326.     char *zTemp;

  46327.     nByte = osGetFullPathNameA((char*)zConverted, 0, 0, 0);

  46328.     if( nByte==0 ){

  46329.       sqlite3_free(zConverted);

  46330.       return winLogError(SQLITE_CANTOPEN_FULLPATH, osGetLastError(),

  46331.                          "winFullPathname3", zRelative);

  46332.     }

  46333.     nByte += 3;

  46334.     zTemp = sqlite3MallocZero( nByte*sizeof(zTemp[0]) );

  46335.     if( zTemp==0 ){

  46336.       sqlite3_free(zConverted);

  46337.       return SQLITE_IOERR_NOMEM_BKPT;

  46338.     }

  46339.     nByte = osGetFullPathNameA((char*)zConverted, nByte, zTemp, 0);

  46340.     if( nByte==0 ){

  46341.       sqlite3_free(zConverted);

  46342.       sqlite3_free(zTemp);

  46343.       return winLogError(SQLITE_CANTOPEN_FULLPATH, osGetLastError(),

  46344.                          "winFullPathname4", zRelative);

  46345.     }

  46346.     sqlite3_free(zConverted);

  46347.     zOut = winMbcsToUtf8(zTemp, osAreFileApisANSI());

  46348.     sqlite3_free(zTemp);

  46349.   }

  46350. #endif

  46351.   if( zOut ){

  46352.     sqlite3_snprintf(MIN(nFull, pVfs->mxPathname), zFull, "%s", zOut);

  46353.     sqlite3_free(zOut);

  46354.     return SQLITE_OK;

  46355.   }else{

  46356.     return SQLITE_IOERR_NOMEM_BKPT;

  46357.   }

  46358. #endif

  46359. }

  46360. 

  46361. #ifndef SQLITE_OMIT_LOAD_EXTENSION

  46362. /*

  46363. ** Interfaces for opening a shared library, finding entry points

  46364. ** within the shared library, and closing the shared library.

  46365. */

  46366. static void *winDlOpen(sqlite3_vfs *pVfs, const char *zFilename){

  46367.   HANDLE h;

  46368. #if defined(__CYGWIN__)

  46369.   int nFull = pVfs->mxPathname+1;

  46370.   char *zFull = sqlite3MallocZero( nFull );

  46371.   void *zConverted = 0;

  46372.   if( zFull==0 ){

  46373.     OSTRACE(("DLOPEN name=%s, handle=%p\n", zFilename, (void*)0));

  46374.     return 0;

  46375.   }

  46376.   if( winFullPathname(pVfs, zFilename, nFull, zFull)!=SQLITE_OK ){

  46377.     sqlite3_free(zFull);

  46378.     OSTRACE(("DLOPEN name=%s, handle=%p\n", zFilename, (void*)0));

  46379.     return 0;

  46380.   }

  46381.   zConverted = winConvertFromUtf8Filename(zFull);

  46382.   sqlite3_free(zFull);

  46383. #else

  46384.   void *zConverted = winConvertFromUtf8Filename(zFilename);

  46385.   UNUSED_PARAMETER(pVfs);

  46386. #endif

  46387.   if( zConverted==0 ){

  46388.     OSTRACE(("DLOPEN name=%s, handle=%p\n", zFilename, (void*)0));

  46389.     return 0;

  46390.   }

  46391.   if( osIsNT() ){

  46392. #if SQLITE_OS_WINRT

  46393.     h = osLoadPackagedLibrary((LPCWSTR)zConverted, 0);

  46394. #else

  46395.     h = osLoadLibraryW((LPCWSTR)zConverted);

  46396. #endif

  46397.   }

  46398. #ifdef SQLITE_WIN32_HAS_ANSI

  46399.   else{

  46400.     h = osLoadLibraryA((char*)zConverted);

  46401.   }

  46402. #endif

  46403.   OSTRACE(("DLOPEN name=%s, handle=%p\n", zFilename, (void*)h));

  46404.   sqlite3_free(zConverted);

  46405.   return (void*)h;

  46406. }

  46407. static void winDlError(sqlite3_vfs *pVfs, int nBuf, char *zBufOut){

  46408.   UNUSED_PARAMETER(pVfs);

  46409.   winGetLastErrorMsg(osGetLastError(), nBuf, zBufOut);

  46410. }

  46411. static void (*winDlSym(sqlite3_vfs *pVfs,void *pH,const char *zSym))(void){

  46412.   FARPROC proc;

  46413.   UNUSED_PARAMETER(pVfs);

  46414.   proc = osGetProcAddressA((HANDLE)pH, zSym);

  46415.   OSTRACE(("DLSYM handle=%p, symbol=%s, address=%p\n",

  46416.            (void*)pH, zSym, (void*)proc));

  46417.   return (void(*)(void))proc;

  46418. }

  46419. static void winDlClose(sqlite3_vfs *pVfs, void *pHandle){

  46420.   UNUSED_PARAMETER(pVfs);

  46421.   osFreeLibrary((HANDLE)pHandle);

  46422.   OSTRACE(("DLCLOSE handle=%p\n", (void*)pHandle));

  46423. }

  46424. #else /* if SQLITE_OMIT_LOAD_EXTENSION is defined: */

  46425.   #define winDlOpen  0

  46426.   #define winDlError 0

  46427.   #define winDlSym   0

  46428.   #define winDlClose 0

  46429. #endif

  46430. 

  46431. /* State information for the randomness gatherer. */

  46432. typedef struct EntropyGatherer EntropyGatherer;

  46433. struct EntropyGatherer {

  46434.   unsigned char *a;   /* Gather entropy into this buffer */

  46435.   int na;             /* Size of a[] in bytes */

  46436.   int i;              /* XOR next input into a[i] */

  46437.   int nXor;           /* Number of XOR operations done */

  46438. };

  46439. 

  46440. #if !defined(SQLITE_TEST) && !defined(SQLITE_OMIT_RANDOMNESS)

  46441. /* Mix sz bytes of entropy into p. */

  46442. static void xorMemory(EntropyGatherer *p, unsigned char *x, int sz){

  46443.   int j, k;

  46444.   for(j=0, k=p->i; j<sz; j++){

  46445.     p->a[k++] ^= x[j];

  46446.     if( k>=p->na ) k = 0;

  46447.   }

  46448.   p->i = k;

  46449.   p->nXor += sz;

  46450. }

  46451. #endif /* !defined(SQLITE_TEST) && !defined(SQLITE_OMIT_RANDOMNESS) */

  46452. 

  46453. /*

  46454. ** Write up to nBuf bytes of randomness into zBuf.

  46455. */

  46456. static int winRandomness(sqlite3_vfs *pVfs, int nBuf, char *zBuf){

  46457. #if defined(SQLITE_TEST) || defined(SQLITE_OMIT_RANDOMNESS)

  46458.   UNUSED_PARAMETER(pVfs);

  46459.   memset(zBuf, 0, nBuf);

  46460.   return nBuf;

  46461. #else

  46462.   EntropyGatherer e;

  46463.   UNUSED_PARAMETER(pVfs);

  46464.   memset(zBuf, 0, nBuf);

  46465.   e.a = (unsigned char*)zBuf;

  46466.   e.na = nBuf;

  46467.   e.nXor = 0;

  46468.   e.i = 0;

  46469.   {

  46470.     SYSTEMTIME x;

  46471.     osGetSystemTime(&x);

  46472.     xorMemory(&e, (unsigned char*)&x, sizeof(SYSTEMTIME));

  46473.   }

  46474.   {

  46475.     DWORD pid = osGetCurrentProcessId();

  46476.     xorMemory(&e, (unsigned char*)&pid, sizeof(DWORD));

  46477.   }

  46478. #if SQLITE_OS_WINRT

  46479.   {

  46480.     ULONGLONG cnt = osGetTickCount64();

  46481.     xorMemory(&e, (unsigned char*)&cnt, sizeof(ULONGLONG));

  46482.   }

  46483. #else

  46484.   {

  46485.     DWORD cnt = osGetTickCount();

  46486.     xorMemory(&e, (unsigned char*)&cnt, sizeof(DWORD));

  46487.   }

  46488. #endif /* SQLITE_OS_WINRT */

  46489.   {

  46490.     LARGE_INTEGER i;

  46491.     osQueryPerformanceCounter(&i);

  46492.     xorMemory(&e, (unsigned char*)&i, sizeof(LARGE_INTEGER));

  46493.   }

  46494. #if !SQLITE_OS_WINCE && !SQLITE_OS_WINRT && SQLITE_WIN32_USE_UUID

  46495.   {

  46496.     UUID id;

  46497.     memset(&id, 0, sizeof(UUID));

  46498.     osUuidCreate(&id);

  46499.     xorMemory(&e, (unsigned char*)&id, sizeof(UUID));

  46500.     memset(&id, 0, sizeof(UUID));

  46501.     osUuidCreateSequential(&id);

  46502.     xorMemory(&e, (unsigned char*)&id, sizeof(UUID));

  46503.   }

  46504. #endif /* !SQLITE_OS_WINCE && !SQLITE_OS_WINRT && SQLITE_WIN32_USE_UUID */

  46505.   return e.nXor>nBuf ? nBuf : e.nXor;

  46506. #endif /* defined(SQLITE_TEST) || defined(SQLITE_OMIT_RANDOMNESS) */

  46507. }

  46508. 

  46509. 

  46510. /*

  46511. ** Sleep for a little while.  Return the amount of time slept.

  46512. */

  46513. static int winSleep(sqlite3_vfs *pVfs, int microsec){

  46514.   sqlite3_win32_sleep((microsec+999)/1000);

  46515.   UNUSED_PARAMETER(pVfs);

  46516.   return ((microsec+999)/1000)*1000;

  46517. }

  46518. 

  46519. /*

  46520. ** The following variable, if set to a non-zero value, is interpreted as

  46521. ** the number of seconds since 1970 and is used to set the result of

  46522. ** sqlite3OsCurrentTime() during testing.

  46523. */

  46524. #ifdef SQLITE_TEST

  46525. SQLITE_API int sqlite3_current_time = 0;  /* Fake system time in seconds since 1970. */

  46526. #endif

  46527. 

  46528. /*

  46529. ** Find the current time (in Universal Coordinated Time).  Write into *piNow

  46530. ** the current time and date as a Julian Day number times 86_400_000.  In

  46531. ** other words, write into *piNow the number of milliseconds since the Julian

  46532. ** epoch of noon in Greenwich on November 24, 4714 B.C according to the

  46533. ** proleptic Gregorian calendar.

  46534. **

  46535. ** On success, return SQLITE_OK.  Return SQLITE_ERROR if the time and date

  46536. ** cannot be found.

  46537. */

  46538. static int winCurrentTimeInt64(sqlite3_vfs *pVfs, sqlite3_int64 *piNow){

  46539.   /* FILETIME structure is a 64-bit value representing the number of

  46540.      100-nanosecond intervals since January 1, 1601 (= JD 2305813.5).

  46541.   */

  46542.   FILETIME ft;

  46543.   static const sqlite3_int64 winFiletimeEpoch = 23058135*(sqlite3_int64)8640000;

  46544. #ifdef SQLITE_TEST

  46545.   static const sqlite3_int64 unixEpoch = 24405875*(sqlite3_int64)8640000;

  46546. #endif

  46547.   /* 2^32 - to avoid use of LL and warnings in gcc */

  46548.   static const sqlite3_int64 max32BitValue =

  46549.       (sqlite3_int64)2000000000 + (sqlite3_int64)2000000000 +

  46550.       (sqlite3_int64)294967296;

  46551. 

  46552. #if SQLITE_OS_WINCE

  46553.   SYSTEMTIME time;

  46554.   osGetSystemTime(&time);

  46555.   /* if SystemTimeToFileTime() fails, it returns zero. */

  46556.   if (!osSystemTimeToFileTime(&time,&ft)){

  46557.     return SQLITE_ERROR;

  46558.   }

  46559. #else

  46560.   osGetSystemTimeAsFileTime( &ft );

  46561. #endif

  46562. 

  46563.   *piNow = winFiletimeEpoch +

  46564.             ((((sqlite3_int64)ft.dwHighDateTime)*max32BitValue) +

  46565.                (sqlite3_int64)ft.dwLowDateTime)/(sqlite3_int64)10000;

  46566. 

  46567. #ifdef SQLITE_TEST

  46568.   if( sqlite3_current_time ){

  46569.     *piNow = 1000*(sqlite3_int64)sqlite3_current_time + unixEpoch;

  46570.   }

  46571. #endif

  46572.   UNUSED_PARAMETER(pVfs);

  46573.   return SQLITE_OK;

  46574. }

  46575. 

  46576. /*

  46577. ** Find the current time (in Universal Coordinated Time).  Write the

  46578. ** current time and date as a Julian Day number into *prNow and

  46579. ** return 0.  Return 1 if the time and date cannot be found.

  46580. */

  46581. static int winCurrentTime(sqlite3_vfs *pVfs, double *prNow){

  46582.   int rc;

  46583.   sqlite3_int64 i;

  46584.   rc = winCurrentTimeInt64(pVfs, &i);

  46585.   if( !rc ){

  46586.     *prNow = i/86400000.0;

  46587.   }

  46588.   return rc;

  46589. }

  46590. 

  46591. /*

  46592. ** The idea is that this function works like a combination of

  46593. ** GetLastError() and FormatMessage() on Windows (or errno and

  46594. ** strerror_r() on Unix). After an error is returned by an OS

  46595. ** function, SQLite calls this function with zBuf pointing to

  46596. ** a buffer of nBuf bytes. The OS layer should populate the

  46597. ** buffer with a nul-terminated UTF-8 encoded error message

  46598. ** describing the last IO error to have occurred within the calling

  46599. ** thread.

  46600. **

  46601. ** If the error message is too large for the supplied buffer,

  46602. ** it should be truncated. The return value of xGetLastError

  46603. ** is zero if the error message fits in the buffer, or non-zero

  46604. ** otherwise (if the message was truncated). If non-zero is returned,

  46605. ** then it is not necessary to include the nul-terminator character

  46606. ** in the output buffer.

  46607. **

  46608. ** Not supplying an error message will have no adverse effect

  46609. ** on SQLite. It is fine to have an implementation that never

  46610. ** returns an error message:

  46611. **

  46612. **   int xGetLastError(sqlite3_vfs *pVfs, int nBuf, char *zBuf){

  46613. **     assert(zBuf[0]=='\0');

  46614. **     return 0;

  46615. **   }

  46616. **

  46617. ** However if an error message is supplied, it will be incorporated

  46618. ** by sqlite into the error message available to the user using

  46619. ** sqlite3_errmsg(), possibly making IO errors easier to debug.

  46620. */

  46621. static int winGetLastError(sqlite3_vfs *pVfs, int nBuf, char *zBuf){

  46622.   DWORD e = osGetLastError();

  46623.   UNUSED_PARAMETER(pVfs);

  46624.   if( nBuf>0 ) winGetLastErrorMsg(e, nBuf, zBuf);

  46625.   return e;

  46626. }

  46627. 

  46628. /*

  46629. ** Initialize and deinitialize the operating system interface.

  46630. */

  46631. SQLITE_API int sqlite3_os_init(void){

  46632.   static sqlite3_vfs winVfs = {

  46633.     3,                     /* iVersion */

  46634.     sizeof(winFile),       /* szOsFile */

  46635.     SQLITE_WIN32_MAX_PATH_BYTES, /* mxPathname */

  46636.     0,                     /* pNext */

  46637.     "win32",               /* zName */

  46638.     &winAppData,           /* pAppData */

  46639.     winOpen,               /* xOpen */

  46640.     winDelete,             /* xDelete */

  46641.     winAccess,             /* xAccess */

  46642.     winFullPathname,       /* xFullPathname */

  46643.     winDlOpen,             /* xDlOpen */

  46644.     winDlError,            /* xDlError */

  46645.     winDlSym,              /* xDlSym */

  46646.     winDlClose,            /* xDlClose */

  46647.     winRandomness,         /* xRandomness */

  46648.     winSleep,              /* xSleep */

  46649.     winCurrentTime,        /* xCurrentTime */

  46650.     winGetLastError,       /* xGetLastError */

  46651.     winCurrentTimeInt64,   /* xCurrentTimeInt64 */

  46652.     winSetSystemCall,      /* xSetSystemCall */

  46653.     winGetSystemCall,      /* xGetSystemCall */

  46654.     winNextSystemCall,     /* xNextSystemCall */

  46655.   };

  46656. #if defined(SQLITE_WIN32_HAS_WIDE)

  46657.   static sqlite3_vfs winLongPathVfs = {

  46658.     3,                     /* iVersion */

  46659.     sizeof(winFile),       /* szOsFile */

  46660.     SQLITE_WINNT_MAX_PATH_BYTES, /* mxPathname */

  46661.     0,                     /* pNext */

  46662.     "win32-longpath",      /* zName */

  46663.     &winAppData,           /* pAppData */

  46664.     winOpen,               /* xOpen */

  46665.     winDelete,             /* xDelete */

  46666.     winAccess,             /* xAccess */

  46667.     winFullPathname,       /* xFullPathname */

  46668.     winDlOpen,             /* xDlOpen */

  46669.     winDlError,            /* xDlError */

  46670.     winDlSym,              /* xDlSym */

  46671.     winDlClose,            /* xDlClose */

  46672.     winRandomness,         /* xRandomness */

  46673.     winSleep,              /* xSleep */

  46674.     winCurrentTime,        /* xCurrentTime */

  46675.     winGetLastError,       /* xGetLastError */

  46676.     winCurrentTimeInt64,   /* xCurrentTimeInt64 */

  46677.     winSetSystemCall,      /* xSetSystemCall */

  46678.     winGetSystemCall,      /* xGetSystemCall */

  46679.     winNextSystemCall,     /* xNextSystemCall */

  46680.   };

  46681. #endif

  46682.   static sqlite3_vfs winNolockVfs = {

  46683.     3,                     /* iVersion */

  46684.     sizeof(winFile),       /* szOsFile */

  46685.     SQLITE_WIN32_MAX_PATH_BYTES, /* mxPathname */

  46686.     0,                     /* pNext */

  46687.     "win32-none",          /* zName */

  46688.     &winNolockAppData,     /* pAppData */

  46689.     winOpen,               /* xOpen */

  46690.     winDelete,             /* xDelete */

  46691.     winAccess,             /* xAccess */

  46692.     winFullPathname,       /* xFullPathname */

  46693.     winDlOpen,             /* xDlOpen */

  46694.     winDlError,            /* xDlError */

  46695.     winDlSym,              /* xDlSym */

  46696.     winDlClose,            /* xDlClose */

  46697.     winRandomness,         /* xRandomness */

  46698.     winSleep,              /* xSleep */

  46699.     winCurrentTime,        /* xCurrentTime */

  46700.     winGetLastError,       /* xGetLastError */

  46701.     winCurrentTimeInt64,   /* xCurrentTimeInt64 */

  46702.     winSetSystemCall,      /* xSetSystemCall */

  46703.     winGetSystemCall,      /* xGetSystemCall */

  46704.     winNextSystemCall,     /* xNextSystemCall */

  46705.   };

  46706. #if defined(SQLITE_WIN32_HAS_WIDE)

  46707.   static sqlite3_vfs winLongPathNolockVfs = {

  46708.     3,                     /* iVersion */

  46709.     sizeof(winFile),       /* szOsFile */

  46710.     SQLITE_WINNT_MAX_PATH_BYTES, /* mxPathname */

  46711.     0,                     /* pNext */

  46712.     "win32-longpath-none", /* zName */

  46713.     &winNolockAppData,     /* pAppData */

  46714.     winOpen,               /* xOpen */

  46715.     winDelete,             /* xDelete */

  46716.     winAccess,             /* xAccess */

  46717.     winFullPathname,       /* xFullPathname */

  46718.     winDlOpen,             /* xDlOpen */

  46719.     winDlError,            /* xDlError */

  46720.     winDlSym,              /* xDlSym */

  46721.     winDlClose,            /* xDlClose */

  46722.     winRandomness,         /* xRandomness */

  46723.     winSleep,              /* xSleep */

  46724.     winCurrentTime,        /* xCurrentTime */

  46725.     winGetLastError,       /* xGetLastError */

  46726.     winCurrentTimeInt64,   /* xCurrentTimeInt64 */

  46727.     winSetSystemCall,      /* xSetSystemCall */

  46728.     winGetSystemCall,      /* xGetSystemCall */

  46729.     winNextSystemCall,     /* xNextSystemCall */

  46730.   };

  46731. #endif

  46732. 

  46733.   /* Double-check that the aSyscall[] array has been constructed

  46734.   ** correctly.  See ticket [bb3a86e890c8e96ab] */

  46735.   assert( ArraySize(aSyscall)==80 );

  46736. 

  46737.   /* get memory map allocation granularity */

  46738.   memset(&winSysInfo, 0, sizeof(SYSTEM_INFO));

  46739. #if SQLITE_OS_WINRT

  46740.   osGetNativeSystemInfo(&winSysInfo);

  46741. #else

  46742.   osGetSystemInfo(&winSysInfo);

  46743. #endif

  46744.   assert( winSysInfo.dwAllocationGranularity>0 );

  46745.   assert( winSysInfo.dwPageSize>0 );

  46746. 

  46747.   sqlite3_vfs_register(&winVfs, 1);

  46748. 

  46749. #if defined(SQLITE_WIN32_HAS_WIDE)

  46750.   sqlite3_vfs_register(&winLongPathVfs, 0);

  46751. #endif

  46752. 

  46753.   sqlite3_vfs_register(&winNolockVfs, 0);

  46754. 

  46755. #if defined(SQLITE_WIN32_HAS_WIDE)

  46756.   sqlite3_vfs_register(&winLongPathNolockVfs, 0);

  46757. #endif

  46758. 

  46759. #ifndef SQLITE_OMIT_WAL

  46760.   winBigLock = sqlite3MutexAlloc(SQLITE_MUTEX_STATIC_VFS1);

  46761. #endif

  46762. 

  46763.   return SQLITE_OK;

  46764. }

  46765. 

  46766. SQLITE_API int sqlite3_os_end(void){

  46767. #if SQLITE_OS_WINRT

  46768.   if( sleepObj!=NULL ){

  46769.     osCloseHandle(sleepObj);

  46770.     sleepObj = NULL;

  46771.   }

  46772. #endif

  46773. 

  46774. #ifndef SQLITE_OMIT_WAL

  46775.   winBigLock = 0;

  46776. #endif

  46777. 

  46778.   return SQLITE_OK;

  46779. }

  46780. 

  46781. #endif /* SQLITE_OS_WIN */

  46782. 

  46783. /************** End of os_win.c **********************************************/

  46784. /************** Begin file memdb.c *******************************************/

  46785. /*

  46786. ** 2016-09-07

  46787. **

  46788. ** The author disclaims copyright to this source code.  In place of

  46789. ** a legal notice, here is a blessing:

  46790. **

  46791. **    May you do good and not evil.

  46792. **    May you find forgiveness for yourself and forgive others.

  46793. **    May you share freely, never taking more than you give.

  46794. **

  46795. ******************************************************************************

  46796. **

  46797. ** This file implements an in-memory VFS. A database is held as a contiguous

  46798. ** block of memory.

  46799. **

  46800. ** This file also implements interface sqlite3_serialize() and

  46801. ** sqlite3_deserialize().

  46802. */

  46803. /* #include "sqliteInt.h" */

  46804. #ifdef SQLITE_ENABLE_DESERIALIZE

  46805. 

  46806. /*

  46807. ** Forward declaration of objects used by this utility

  46808. */

  46809. typedef struct sqlite3_vfs MemVfs;

  46810. typedef struct MemFile MemFile;

  46811. 

  46812. /* Access to a lower-level VFS that (might) implement dynamic loading,

  46813. ** access to randomness, etc.

  46814. */

  46815. #define ORIGVFS(p) ((sqlite3_vfs*)((p)->pAppData))

  46816. 

  46817. /* An open file */

  46818. struct MemFile {

  46819.   sqlite3_file base;              /* IO methods */

  46820.   sqlite3_int64 sz;               /* Size of the file */

  46821.   sqlite3_int64 szAlloc;          /* Space allocated to aData */

  46822.   sqlite3_int64 szMax;            /* Maximum allowed size of the file */

  46823.   unsigned char *aData;           /* content of the file */

  46824.   int nMmap;                      /* Number of memory mapped pages */

  46825.   unsigned mFlags;                /* Flags */

  46826.   int eLock;                      /* Most recent lock against this file */

  46827. };

  46828. 

  46829. /*

  46830. ** Methods for MemFile

  46831. */

  46832. static int memdbClose(sqlite3_file*);

  46833. static int memdbRead(sqlite3_file*, void*, int iAmt, sqlite3_int64 iOfst);

  46834. static int memdbWrite(sqlite3_file*,const void*,int iAmt, sqlite3_int64 iOfst);

  46835. static int memdbTruncate(sqlite3_file*, sqlite3_int64 size);

  46836. static int memdbSync(sqlite3_file*, int flags);

  46837. static int memdbFileSize(sqlite3_file*, sqlite3_int64 *pSize);

  46838. static int memdbLock(sqlite3_file*, int);

  46839. /* static int memdbCheckReservedLock(sqlite3_file*, int *pResOut);// not used */

  46840. static int memdbFileControl(sqlite3_file*, int op, void *pArg);

  46841. /* static int memdbSectorSize(sqlite3_file*); // not used */

  46842. static int memdbDeviceCharacteristics(sqlite3_file*);

  46843. static int memdbFetch(sqlite3_file*, sqlite3_int64 iOfst, int iAmt, void **pp);

  46844. static int memdbUnfetch(sqlite3_file*, sqlite3_int64 iOfst, void *p);

  46845. 

  46846. /*

  46847. ** Methods for MemVfs

  46848. */

  46849. static int memdbOpen(sqlite3_vfs*, const char *, sqlite3_file*, int , int *);

  46850. /* static int memdbDelete(sqlite3_vfs*, const char *zName, int syncDir); */

  46851. static int memdbAccess(sqlite3_vfs*, const char *zName, int flags, int *);

  46852. static int memdbFullPathname(sqlite3_vfs*, const char *zName, int, char *zOut);

  46853. static void *memdbDlOpen(sqlite3_vfs*, const char *zFilename);

  46854. static void memdbDlError(sqlite3_vfs*, int nByte, char *zErrMsg);

  46855. static void (*memdbDlSym(sqlite3_vfs *pVfs, void *p, const char*zSym))(void);

  46856. static void memdbDlClose(sqlite3_vfs*, void*);

  46857. static int memdbRandomness(sqlite3_vfs*, int nByte, char *zOut);

  46858. static int memdbSleep(sqlite3_vfs*, int microseconds);

  46859. /* static int memdbCurrentTime(sqlite3_vfs*, double*); */

  46860. static int memdbGetLastError(sqlite3_vfs*, int, char *);

  46861. static int memdbCurrentTimeInt64(sqlite3_vfs*, sqlite3_int64*);

  46862. 

  46863. static sqlite3_vfs memdb_vfs = {

  46864.   2,                           /* iVersion */

  46865.   0,                           /* szOsFile (set when registered) */

  46866.   1024,                        /* mxPathname */

  46867.   0,                           /* pNext */

  46868.   "memdb",                     /* zName */

  46869.   0,                           /* pAppData (set when registered) */ 

  46870.   memdbOpen,                   /* xOpen */

  46871.   0, /* memdbDelete, */        /* xDelete */

  46872.   memdbAccess,                 /* xAccess */

  46873.   memdbFullPathname,           /* xFullPathname */

  46874.   memdbDlOpen,                 /* xDlOpen */

  46875.   memdbDlError,                /* xDlError */

  46876.   memdbDlSym,                  /* xDlSym */

  46877.   memdbDlClose,                /* xDlClose */

  46878.   memdbRandomness,             /* xRandomness */

  46879.   memdbSleep,                  /* xSleep */

  46880.   0, /* memdbCurrentTime, */   /* xCurrentTime */

  46881.   memdbGetLastError,           /* xGetLastError */

  46882.   memdbCurrentTimeInt64        /* xCurrentTimeInt64 */

  46883. };

  46884. 

  46885. static const sqlite3_io_methods memdb_io_methods = {

  46886.   3,                              /* iVersion */

  46887.   memdbClose,                      /* xClose */

  46888.   memdbRead,                       /* xRead */

  46889.   memdbWrite,                      /* xWrite */

  46890.   memdbTruncate,                   /* xTruncate */

  46891.   memdbSync,                       /* xSync */

  46892.   memdbFileSize,                   /* xFileSize */

  46893.   memdbLock,                       /* xLock */

  46894.   memdbLock,                       /* xUnlock - same as xLock in this case */ 

  46895.   0, /* memdbCheckReservedLock, */ /* xCheckReservedLock */

  46896.   memdbFileControl,                /* xFileControl */

  46897.   0, /* memdbSectorSize,*/         /* xSectorSize */

  46898.   memdbDeviceCharacteristics,      /* xDeviceCharacteristics */

  46899.   0,                               /* xShmMap */

  46900.   0,                               /* xShmLock */

  46901.   0,                               /* xShmBarrier */

  46902.   0,                               /* xShmUnmap */

  46903.   memdbFetch,                      /* xFetch */

  46904.   memdbUnfetch                     /* xUnfetch */

  46905. };

  46906. 

  46907. 

  46908. 

  46909. /*

  46910. ** Close an memdb-file.

  46911. **

  46912. ** The pData pointer is owned by the application, so there is nothing

  46913. ** to free.

  46914. */

  46915. static int memdbClose(sqlite3_file *pFile){

  46916.   MemFile *p = (MemFile *)pFile;

  46917.   if( p->mFlags & SQLITE_DESERIALIZE_FREEONCLOSE ) sqlite3_free(p->aData);

  46918.   return SQLITE_OK;

  46919. }

  46920. 

  46921. /*

  46922. ** Read data from an memdb-file.

  46923. */

  46924. static int memdbRead(

  46925.   sqlite3_file *pFile, 

  46926.   void *zBuf, 

  46927.   int iAmt, 

  46928.   sqlite_int64 iOfst

  46929. ){

  46930.   MemFile *p = (MemFile *)pFile;

  46931.   if( iOfst+iAmt>p->sz ){

  46932.     memset(zBuf, 0, iAmt);

  46933.     if( iOfst<p->sz ) memcpy(zBuf, p->aData+iOfst, p->sz - iOfst);

  46934.     return SQLITE_IOERR_SHORT_READ;

  46935.   }

  46936.   memcpy(zBuf, p->aData+iOfst, iAmt);

  46937.   return SQLITE_OK;

  46938. }

  46939. 

  46940. /*

  46941. ** Try to enlarge the memory allocation to hold at least sz bytes

  46942. */

  46943. static int memdbEnlarge(MemFile *p, sqlite3_int64 newSz){

  46944.   unsigned char *pNew;

  46945.   if( (p->mFlags & SQLITE_DESERIALIZE_RESIZEABLE)==0 || p->nMmap>0 ){

  46946.     return SQLITE_FULL;

  46947.   }

  46948.   if( newSz>p->szMax ){

  46949.     return SQLITE_FULL;

  46950.   }

  46951.   newSz *= 2;

  46952.   if( newSz>p->szMax ) newSz = p->szMax;

  46953.   pNew = sqlite3_realloc64(p->aData, newSz);

  46954.   if( pNew==0 ) return SQLITE_NOMEM;

  46955.   p->aData = pNew;

  46956.   p->szAlloc = newSz;

  46957.   return SQLITE_OK;

  46958. }

  46959. 

  46960. /*

  46961. ** Write data to an memdb-file.

  46962. */

  46963. static int memdbWrite(

  46964.   sqlite3_file *pFile,

  46965.   const void *z,

  46966.   int iAmt,

  46967.   sqlite_int64 iOfst

  46968. ){

  46969.   MemFile *p = (MemFile *)pFile;

  46970.   if( NEVER(p->mFlags & SQLITE_DESERIALIZE_READONLY) ) return SQLITE_READONLY;

  46971.   if( iOfst+iAmt>p->sz ){

  46972.     int rc;

  46973.     if( iOfst+iAmt>p->szAlloc

  46974.      && (rc = memdbEnlarge(p, iOfst+iAmt))!=SQLITE_OK

  46975.     ){

  46976.       return rc;

  46977.     }

  46978.     if( iOfst>p->sz ) memset(p->aData+p->sz, 0, iOfst-p->sz);

  46979.     p->sz = iOfst+iAmt;

  46980.   }

  46981.   memcpy(p->aData+iOfst, z, iAmt);

  46982.   return SQLITE_OK;

  46983. }

  46984. 

  46985. /*

  46986. ** Truncate an memdb-file.

  46987. **

  46988. ** In rollback mode (which is always the case for memdb, as it does not

  46989. ** support WAL mode) the truncate() method is only used to reduce

  46990. ** the size of a file, never to increase the size.

  46991. */

  46992. static int memdbTruncate(sqlite3_file *pFile, sqlite_int64 size){

  46993.   MemFile *p = (MemFile *)pFile;

  46994.   if( NEVER(size>p->sz) ) return SQLITE_FULL;

  46995.   p->sz = size; 

  46996.   return SQLITE_OK;

  46997. }

  46998. 

  46999. /*

  47000. ** Sync an memdb-file.

  47001. */

  47002. static int memdbSync(sqlite3_file *pFile, int flags){

  47003.   return SQLITE_OK;

  47004. }

  47005. 

  47006. /*

  47007. ** Return the current file-size of an memdb-file.

  47008. */

  47009. static int memdbFileSize(sqlite3_file *pFile, sqlite_int64 *pSize){

  47010.   MemFile *p = (MemFile *)pFile;

  47011.   *pSize = p->sz;

  47012.   return SQLITE_OK;

  47013. }

  47014. 

  47015. /*

  47016. ** Lock an memdb-file.

  47017. */

  47018. static int memdbLock(sqlite3_file *pFile, int eLock){

  47019.   MemFile *p = (MemFile *)pFile;

  47020.   if( eLock>SQLITE_LOCK_SHARED 

  47021.    && (p->mFlags & SQLITE_DESERIALIZE_READONLY)!=0

  47022.   ){

  47023.     return SQLITE_READONLY;

  47024.   }

  47025.   p->eLock = eLock;

  47026.   return SQLITE_OK;

  47027. }

  47028. 

  47029. #if 0 /* Never used because memdbAccess() always returns false */

  47030. /*

  47031. ** Check if another file-handle holds a RESERVED lock on an memdb-file.

  47032. */

  47033. static int memdbCheckReservedLock(sqlite3_file *pFile, int *pResOut){

  47034.   *pResOut = 0;

  47035.   return SQLITE_OK;

  47036. }

  47037. #endif

  47038. 

  47039. /*

  47040. ** File control method. For custom operations on an memdb-file.

  47041. */

  47042. static int memdbFileControl(sqlite3_file *pFile, int op, void *pArg){

  47043.   MemFile *p = (MemFile *)pFile;

  47044.   int rc = SQLITE_NOTFOUND;

  47045.   if( op==SQLITE_FCNTL_VFSNAME ){

  47046.     *(char**)pArg = sqlite3_mprintf("memdb(%p,%lld)", p->aData, p->sz);

  47047.     rc = SQLITE_OK;

  47048.   }

  47049.   if( op==SQLITE_FCNTL_SIZE_LIMIT ){

  47050.     sqlite3_int64 iLimit = *(sqlite3_int64*)pArg;

  47051.     if( iLimit<p->sz ){

  47052.       if( iLimit<0 ){

  47053.         iLimit = p->szMax;

  47054.       }else{

  47055.         iLimit = p->sz;

  47056.       }

  47057.     }

  47058.     p->szMax = iLimit;

  47059.     *(sqlite3_int64*)pArg = iLimit;

  47060.     rc = SQLITE_OK;

  47061.   }

  47062.   return rc;

  47063. }

  47064. 

  47065. #if 0  /* Not used because of SQLITE_IOCAP_POWERSAFE_OVERWRITE */

  47066. /*

  47067. ** Return the sector-size in bytes for an memdb-file.

  47068. */

  47069. static int memdbSectorSize(sqlite3_file *pFile){

  47070.   return 1024;

  47071. }

  47072. #endif

  47073. 

  47074. /*

  47075. ** Return the device characteristic flags supported by an memdb-file.

  47076. */

  47077. static int memdbDeviceCharacteristics(sqlite3_file *pFile){

  47078.   return SQLITE_IOCAP_ATOMIC | 

  47079.          SQLITE_IOCAP_POWERSAFE_OVERWRITE |

  47080.          SQLITE_IOCAP_SAFE_APPEND |

  47081.          SQLITE_IOCAP_SEQUENTIAL;

  47082. }

  47083. 

  47084. /* Fetch a page of a memory-mapped file */

  47085. static int memdbFetch(

  47086.   sqlite3_file *pFile,

  47087.   sqlite3_int64 iOfst,

  47088.   int iAmt,

  47089.   void **pp

  47090. ){

  47091.   MemFile *p = (MemFile *)pFile;

  47092.   if( iOfst+iAmt>p->sz ){

  47093.     *pp = 0;

  47094.   }else{

  47095.     p->nMmap++;

  47096.     *pp = (void*)(p->aData + iOfst);

  47097.   }

  47098.   return SQLITE_OK;

  47099. }

  47100. 

  47101. /* Release a memory-mapped page */

  47102. static int memdbUnfetch(sqlite3_file *pFile, sqlite3_int64 iOfst, void *pPage){

  47103.   MemFile *p = (MemFile *)pFile;

  47104.   p->nMmap--;

  47105.   return SQLITE_OK;

  47106. }

  47107. 

  47108. /*

  47109. ** Open an mem file handle.

  47110. */

  47111. static int memdbOpen(

  47112.   sqlite3_vfs *pVfs,

  47113.   const char *zName,

  47114.   sqlite3_file *pFile,

  47115.   int flags,

  47116.   int *pOutFlags

  47117. ){

  47118.   MemFile *p = (MemFile*)pFile;

  47119.   if( (flags & SQLITE_OPEN_MAIN_DB)==0 ){

  47120.     return ORIGVFS(pVfs)->xOpen(ORIGVFS(pVfs), zName, pFile, flags, pOutFlags);

  47121.   }

  47122.   memset(p, 0, sizeof(*p));

  47123.   p->mFlags = SQLITE_DESERIALIZE_RESIZEABLE | SQLITE_DESERIALIZE_FREEONCLOSE;

  47124.   assert( pOutFlags!=0 );  /* True because flags==SQLITE_OPEN_MAIN_DB */

  47125.   *pOutFlags = flags | SQLITE_OPEN_MEMORY;

  47126.   p->base.pMethods = &memdb_io_methods;

  47127.   p->szMax = sqlite3GlobalConfig.mxMemdbSize;

  47128.   return SQLITE_OK;

  47129. }

  47130. 

  47131. #if 0 /* Only used to delete rollback journals, master journals, and WAL

  47132.       ** files, none of which exist in memdb.  So this routine is never used */

  47133. /*

  47134. ** Delete the file located at zPath. If the dirSync argument is true,

  47135. ** ensure the file-system modifications are synced to disk before

  47136. ** returning.

  47137. */

  47138. static int memdbDelete(sqlite3_vfs *pVfs, const char *zPath, int dirSync){

  47139.   return SQLITE_IOERR_DELETE;

  47140. }

  47141. #endif

  47142. 

  47143. /*

  47144. ** Test for access permissions. Return true if the requested permission

  47145. ** is available, or false otherwise.

  47146. **

  47147. ** With memdb, no files ever exist on disk.  So always return false.

  47148. */

  47149. static int memdbAccess(

  47150.   sqlite3_vfs *pVfs, 

  47151.   const char *zPath, 

  47152.   int flags, 

  47153.   int *pResOut

  47154. ){

  47155.   *pResOut = 0;

  47156.   return SQLITE_OK;

  47157. }

  47158. 

  47159. /*

  47160. ** Populate buffer zOut with the full canonical pathname corresponding

  47161. ** to the pathname in zPath. zOut is guaranteed to point to a buffer

  47162. ** of at least (INST_MAX_PATHNAME+1) bytes.

  47163. */

  47164. static int memdbFullPathname(

  47165.   sqlite3_vfs *pVfs, 

  47166.   const char *zPath, 

  47167.   int nOut, 

  47168.   char *zOut

  47169. ){

  47170.   sqlite3_snprintf(nOut, zOut, "%s", zPath);

  47171.   return SQLITE_OK;

  47172. }

  47173. 

  47174. /*

  47175. ** Open the dynamic library located at zPath and return a handle.

  47176. */

  47177. static void *memdbDlOpen(sqlite3_vfs *pVfs, const char *zPath){

  47178.   return ORIGVFS(pVfs)->xDlOpen(ORIGVFS(pVfs), zPath);

  47179. }

  47180. 

  47181. /*

  47182. ** Populate the buffer zErrMsg (size nByte bytes) with a human readable

  47183. ** utf-8 string describing the most recent error encountered associated 

  47184. ** with dynamic libraries.

  47185. */

  47186. static void memdbDlError(sqlite3_vfs *pVfs, int nByte, char *zErrMsg){

  47187.   ORIGVFS(pVfs)->xDlError(ORIGVFS(pVfs), nByte, zErrMsg);

  47188. }

  47189. 

  47190. /*

  47191. ** Return a pointer to the symbol zSymbol in the dynamic library pHandle.

  47192. */

  47193. static void (*memdbDlSym(sqlite3_vfs *pVfs, void *p, const char *zSym))(void){

  47194.   return ORIGVFS(pVfs)->xDlSym(ORIGVFS(pVfs), p, zSym);

  47195. }

  47196. 

  47197. /*

  47198. ** Close the dynamic library handle pHandle.

  47199. */

  47200. static void memdbDlClose(sqlite3_vfs *pVfs, void *pHandle){

  47201.   ORIGVFS(pVfs)->xDlClose(ORIGVFS(pVfs), pHandle);

  47202. }

  47203. 

  47204. /*

  47205. ** Populate the buffer pointed to by zBufOut with nByte bytes of 

  47206. ** random data.

  47207. */

  47208. static int memdbRandomness(sqlite3_vfs *pVfs, int nByte, char *zBufOut){

  47209.   return ORIGVFS(pVfs)->xRandomness(ORIGVFS(pVfs), nByte, zBufOut);

  47210. }

  47211. 

  47212. /*

  47213. ** Sleep for nMicro microseconds. Return the number of microseconds 

  47214. ** actually slept.

  47215. */

  47216. static int memdbSleep(sqlite3_vfs *pVfs, int nMicro){

  47217.   return ORIGVFS(pVfs)->xSleep(ORIGVFS(pVfs), nMicro);

  47218. }

  47219. 

  47220. #if 0  /* Never used.  Modern cores only call xCurrentTimeInt64() */

  47221. /*

  47222. ** Return the current time as a Julian Day number in *pTimeOut.

  47223. */

  47224. static int memdbCurrentTime(sqlite3_vfs *pVfs, double *pTimeOut){

  47225.   return ORIGVFS(pVfs)->xCurrentTime(ORIGVFS(pVfs), pTimeOut);

  47226. }

  47227. #endif

  47228. 

  47229. static int memdbGetLastError(sqlite3_vfs *pVfs, int a, char *b){

  47230.   return ORIGVFS(pVfs)->xGetLastError(ORIGVFS(pVfs), a, b);

  47231. }

  47232. static int memdbCurrentTimeInt64(sqlite3_vfs *pVfs, sqlite3_int64 *p){

  47233.   return ORIGVFS(pVfs)->xCurrentTimeInt64(ORIGVFS(pVfs), p);

  47234. }

  47235. 

  47236. /*

  47237. ** Translate a database connection pointer and schema name into a

  47238. ** MemFile pointer.

  47239. */

  47240. static MemFile *memdbFromDbSchema(sqlite3 *db, const char *zSchema){

  47241.   MemFile *p = 0;

  47242.   int rc = sqlite3_file_control(db, zSchema, SQLITE_FCNTL_FILE_POINTER, &p);

  47243.   if( rc ) return 0;

  47244.   if( p->base.pMethods!=&memdb_io_methods ) return 0;

  47245.   return p;

  47246. }

  47247. 

  47248. /*

  47249. ** Return the serialization of a database

  47250. */

  47251. SQLITE_API unsigned char *sqlite3_serialize(

  47252.   sqlite3 *db,              /* The database connection */

  47253.   const char *zSchema,      /* Which database within the connection */

  47254.   sqlite3_int64 *piSize,    /* Write size here, if not NULL */

  47255.   unsigned int mFlags       /* Maybe SQLITE_SERIALIZE_NOCOPY */

  47256. ){

  47257.   MemFile *p;

  47258.   int iDb;

  47259.   Btree *pBt;

  47260.   sqlite3_int64 sz;

  47261.   int szPage = 0;

  47262.   sqlite3_stmt *pStmt = 0;

  47263.   unsigned char *pOut;

  47264.   char *zSql;

  47265.   int rc;

  47266. 

  47267. #ifdef SQLITE_ENABLE_API_ARMOR

  47268.   if( !sqlite3SafetyCheckOk(db) ){

  47269.     (void)SQLITE_MISUSE_BKPT;

  47270.     return 0;

  47271.   }

  47272. #endif

  47273. 

  47274.   if( zSchema==0 ) zSchema = db->aDb[0].zDbSName;

  47275.   p = memdbFromDbSchema(db, zSchema);

  47276.   iDb = sqlite3FindDbName(db, zSchema);

  47277.   if( piSize ) *piSize = -1;

  47278.   if( iDb<0 ) return 0;

  47279.   if( p ){

  47280.     if( piSize ) *piSize = p->sz;

  47281.     if( mFlags & SQLITE_SERIALIZE_NOCOPY ){

  47282.       pOut = p->aData;

  47283.     }else{

  47284.       pOut = sqlite3_malloc64( p->sz );

  47285.       if( pOut ) memcpy(pOut, p->aData, p->sz);

  47286.     }

  47287.     return pOut;

  47288.   }

  47289.   pBt = db->aDb[iDb].pBt;

  47290.   if( pBt==0 ) return 0;

  47291.   szPage = sqlite3BtreeGetPageSize(pBt);

  47292.   zSql = sqlite3_mprintf("PRAGMA \"%w\".page_count", zSchema);

  47293.   rc = zSql ? sqlite3_prepare_v2(db, zSql, -1, &pStmt, 0) : SQLITE_NOMEM;

  47294.   sqlite3_free(zSql);

  47295.   if( rc ) return 0;

  47296.   rc = sqlite3_step(pStmt);

  47297.   if( rc!=SQLITE_ROW ){

  47298.     pOut = 0;

  47299.   }else{

  47300.     sz = sqlite3_column_int64(pStmt, 0)*szPage;

  47301.     if( piSize ) *piSize = sz;

  47302.     if( mFlags & SQLITE_SERIALIZE_NOCOPY ){

  47303.       pOut = 0;

  47304.     }else{

  47305.       pOut = sqlite3_malloc64( sz );

  47306.       if( pOut ){

  47307.         int nPage = sqlite3_column_int(pStmt, 0);

  47308.         Pager *pPager = sqlite3BtreePager(pBt);

  47309.         int pgno;

  47310.         for(pgno=1; pgno<=nPage; pgno++){

  47311.           DbPage *pPage = 0;

  47312.           unsigned char *pTo = pOut + szPage*(sqlite3_int64)(pgno-1);

  47313.           rc = sqlite3PagerGet(pPager, pgno, (DbPage**)&pPage, 0);

  47314.           if( rc==SQLITE_OK ){

  47315.             memcpy(pTo, sqlite3PagerGetData(pPage), szPage);

  47316.           }else{

  47317.             memset(pTo, 0, szPage);

  47318.           }

  47319.           sqlite3PagerUnref(pPage);       

  47320.         }

  47321.       }

  47322.     }

  47323.   }

  47324.   sqlite3_finalize(pStmt);

  47325.   return pOut;

  47326. }

  47327. 

  47328. /* Convert zSchema to a MemDB and initialize its content.

  47329. */

  47330. SQLITE_API int sqlite3_deserialize(

  47331.   sqlite3 *db,            /* The database connection */

  47332.   const char *zSchema,    /* Which DB to reopen with the deserialization */

  47333.   unsigned char *pData,   /* The serialized database content */

  47334.   sqlite3_int64 szDb,     /* Number bytes in the deserialization */

  47335.   sqlite3_int64 szBuf,    /* Total size of buffer pData[] */

  47336.   unsigned mFlags         /* Zero or more SQLITE_DESERIALIZE_* flags */

  47337. ){

  47338.   MemFile *p;

  47339.   char *zSql;

  47340.   sqlite3_stmt *pStmt = 0;

  47341.   int rc;

  47342.   int iDb;

  47343. 

  47344. #ifdef SQLITE_ENABLE_API_ARMOR

  47345.   if( !sqlite3SafetyCheckOk(db) ){

  47346.     return SQLITE_MISUSE_BKPT;

  47347.   }

  47348.   if( szDb<0 ) return SQLITE_MISUSE_BKPT;

  47349.   if( szBuf<0 ) return SQLITE_MISUSE_BKPT;

  47350. #endif

  47351. 

  47352.   sqlite3_mutex_enter(db->mutex);

  47353.   if( zSchema==0 ) zSchema = db->aDb[0].zDbSName;

  47354.   iDb = sqlite3FindDbName(db, zSchema);

  47355.   if( iDb<0 ){

  47356.     rc = SQLITE_ERROR;

  47357.     goto end_deserialize;

  47358.   }    

  47359.   zSql = sqlite3_mprintf("ATTACH x AS %Q", zSchema);

  47360.   rc = sqlite3_prepare_v2(db, zSql, -1, &pStmt, 0);

  47361.   sqlite3_free(zSql);

  47362.   if( rc ) goto end_deserialize;

  47363.   db->init.iDb = (u8)iDb;

  47364.   db->init.reopenMemdb = 1;

  47365.   rc = sqlite3_step(pStmt);

  47366.   db->init.reopenMemdb = 0;

  47367.   if( rc!=SQLITE_DONE ){

  47368.     rc = SQLITE_ERROR;

  47369.     goto end_deserialize;

  47370.   }

  47371.   p = memdbFromDbSchema(db, zSchema);

  47372.   if( p==0 ){

  47373.     rc = SQLITE_ERROR;

  47374.   }else{

  47375.     p->aData = pData;

  47376.     p->sz = szDb;

  47377.     p->szAlloc = szBuf;

  47378.     p->szMax = szBuf;

  47379.     if( p->szMax<sqlite3GlobalConfig.mxMemdbSize ){

  47380.       p->szMax = sqlite3GlobalConfig.mxMemdbSize;

  47381.     }

  47382.     p->mFlags = mFlags;

  47383.     rc = SQLITE_OK;

  47384.   }

  47385. 

  47386. end_deserialize:

  47387.   sqlite3_finalize(pStmt);

  47388.   sqlite3_mutex_leave(db->mutex);

  47389.   return rc;

  47390. }

  47391. 

  47392. /* 

  47393. ** This routine is called when the extension is loaded.

  47394. ** Register the new VFS.

  47395. */

  47396. SQLITE_PRIVATE int sqlite3MemdbInit(void){

  47397.   sqlite3_vfs *pLower = sqlite3_vfs_find(0);

  47398.   int sz = pLower->szOsFile;

  47399.   memdb_vfs.pAppData = pLower;

  47400.   /* In all known configurations of SQLite, the size of a default

  47401.   ** sqlite3_file is greater than the size of a memdb sqlite3_file.

  47402.   ** Should that ever change, remove the following NEVER() */

  47403.   if( NEVER(sz<sizeof(MemFile)) ) sz = sizeof(MemFile);

  47404.   memdb_vfs.szOsFile = sz;

  47405.   return sqlite3_vfs_register(&memdb_vfs, 0);

  47406. }

  47407. #endif /* SQLITE_ENABLE_DESERIALIZE */

  47408. 

  47409. /************** End of memdb.c ***********************************************/

  47410. /************** Begin file bitvec.c ******************************************/

  47411. /*

  47412. ** 2008 February 16

  47413. **

  47414. ** The author disclaims copyright to this source code.  In place of

  47415. ** a legal notice, here is a blessing:

  47416. **

  47417. **    May you do good and not evil.

  47418. **    May you find forgiveness for yourself and forgive others.

  47419. **    May you share freely, never taking more than you give.

  47420. **

  47421. *************************************************************************

  47422. ** This file implements an object that represents a fixed-length

  47423. ** bitmap.  Bits are numbered starting with 1.

  47424. **

  47425. ** A bitmap is used to record which pages of a database file have been

  47426. ** journalled during a transaction, or which pages have the "dont-write"

  47427. ** property.  Usually only a few pages are meet either condition.

  47428. ** So the bitmap is usually sparse and has low cardinality.

  47429. ** But sometimes (for example when during a DROP of a large table) most

  47430. ** or all of the pages in a database can get journalled.  In those cases, 

  47431. ** the bitmap becomes dense with high cardinality.  The algorithm needs 

  47432. ** to handle both cases well.

  47433. **

  47434. ** The size of the bitmap is fixed when the object is created.

  47435. **

  47436. ** All bits are clear when the bitmap is created.  Individual bits

  47437. ** may be set or cleared one at a time.

  47438. **

  47439. ** Test operations are about 100 times more common that set operations.

  47440. ** Clear operations are exceedingly rare.  There are usually between

  47441. ** 5 and 500 set operations per Bitvec object, though the number of sets can

  47442. ** sometimes grow into tens of thousands or larger.  The size of the

  47443. ** Bitvec object is the number of pages in the database file at the

  47444. ** start of a transaction, and is thus usually less than a few thousand,

  47445. ** but can be as large as 2 billion for a really big database.

  47446. */

  47447. /* #include "sqliteInt.h" */

  47448. 

  47449. /* Size of the Bitvec structure in bytes. */

  47450. #define BITVEC_SZ        512

  47451. 

  47452. /* Round the union size down to the nearest pointer boundary, since that's how 

  47453. ** it will be aligned within the Bitvec struct. */

  47454. #define BITVEC_USIZE \

  47455.     (((BITVEC_SZ-(3*sizeof(u32)))/sizeof(Bitvec*))*sizeof(Bitvec*))

  47456. 

  47457. /* Type of the array "element" for the bitmap representation. 

  47458. ** Should be a power of 2, and ideally, evenly divide into BITVEC_USIZE. 

  47459. ** Setting this to the "natural word" size of your CPU may improve

  47460. ** performance. */

  47461. #define BITVEC_TELEM     u8

  47462. /* Size, in bits, of the bitmap element. */

  47463. #define BITVEC_SZELEM    8

  47464. /* Number of elements in a bitmap array. */

  47465. #define BITVEC_NELEM     (BITVEC_USIZE/sizeof(BITVEC_TELEM))

  47466. /* Number of bits in the bitmap array. */

  47467. #define BITVEC_NBIT      (BITVEC_NELEM*BITVEC_SZELEM)

  47468. 

  47469. /* Number of u32 values in hash table. */

  47470. #define BITVEC_NINT      (BITVEC_USIZE/sizeof(u32))

  47471. /* Maximum number of entries in hash table before 

  47472. ** sub-dividing and re-hashing. */

  47473. #define BITVEC_MXHASH    (BITVEC_NINT/2)

  47474. /* Hashing function for the aHash representation.

  47475. ** Empirical testing showed that the *37 multiplier 

  47476. ** (an arbitrary prime)in the hash function provided 

  47477. ** no fewer collisions than the no-op *1. */

  47478. #define BITVEC_HASH(X)   (((X)*1)%BITVEC_NINT)

  47479. 

  47480. #define BITVEC_NPTR      (BITVEC_USIZE/sizeof(Bitvec *))

  47481. 

  47482. 

  47483. /*

  47484. ** A bitmap is an instance of the following structure.

  47485. **

  47486. ** This bitmap records the existence of zero or more bits

  47487. ** with values between 1 and iSize, inclusive.

  47488. **

  47489. ** There are three possible representations of the bitmap.

  47490. ** If iSize<=BITVEC_NBIT, then Bitvec.u.aBitmap[] is a straight

  47491. ** bitmap.  The least significant bit is bit 1.

  47492. **

  47493. ** If iSize>BITVEC_NBIT and iDivisor==0 then Bitvec.u.aHash[] is

  47494. ** a hash table that will hold up to BITVEC_MXHASH distinct values.

  47495. **

  47496. ** Otherwise, the value i is redirected into one of BITVEC_NPTR

  47497. ** sub-bitmaps pointed to by Bitvec.u.apSub[].  Each subbitmap

  47498. ** handles up to iDivisor separate values of i.  apSub[0] holds

  47499. ** values between 1 and iDivisor.  apSub[1] holds values between

  47500. ** iDivisor+1 and 2*iDivisor.  apSub[N] holds values between

  47501. ** N*iDivisor+1 and (N+1)*iDivisor.  Each subbitmap is normalized

  47502. ** to hold deal with values between 1 and iDivisor.

  47503. */

  47504. struct Bitvec {

  47505.   u32 iSize;      /* Maximum bit index.  Max iSize is 4,294,967,296. */

  47506.   u32 nSet;       /* Number of bits that are set - only valid for aHash

  47507.                   ** element.  Max is BITVEC_NINT.  For BITVEC_SZ of 512,

  47508.                   ** this would be 125. */

  47509.   u32 iDivisor;   /* Number of bits handled by each apSub[] entry. */

  47510.                   /* Should >=0 for apSub element. */

  47511.                   /* Max iDivisor is max(u32) / BITVEC_NPTR + 1.  */

  47512.                   /* For a BITVEC_SZ of 512, this would be 34,359,739. */

  47513.   union {

  47514.     BITVEC_TELEM aBitmap[BITVEC_NELEM];    /* Bitmap representation */

  47515.     u32 aHash[BITVEC_NINT];      /* Hash table representation */

  47516.     Bitvec *apSub[BITVEC_NPTR];  /* Recursive representation */

  47517.   } u;

  47518. };

  47519. 

  47520. /*

  47521. ** Create a new bitmap object able to handle bits between 0 and iSize,

  47522. ** inclusive.  Return a pointer to the new object.  Return NULL if 

  47523. ** malloc fails.

  47524. */

  47525. SQLITE_PRIVATE Bitvec *sqlite3BitvecCreate(u32 iSize){

  47526.   Bitvec *p;

  47527.   assert( sizeof(*p)==BITVEC_SZ );

  47528.   p = sqlite3MallocZero( sizeof(*p) );

  47529.   if( p ){

  47530.     p->iSize = iSize;

  47531.   }

  47532.   return p;

  47533. }

  47534. 

  47535. /*

  47536. ** Check to see if the i-th bit is set.  Return true or false.

  47537. ** If p is NULL (if the bitmap has not been created) or if

  47538. ** i is out of range, then return false.

  47539. */

  47540. SQLITE_PRIVATE int sqlite3BitvecTestNotNull(Bitvec *p, u32 i){

  47541.   assert( p!=0 );

  47542.   i--;

  47543.   if( i>=p->iSize ) return 0;

  47544.   while( p->iDivisor ){

  47545.     u32 bin = i/p->iDivisor;

  47546.     i = i%p->iDivisor;

  47547.     p = p->u.apSub[bin];

  47548.     if (!p) {

  47549.       return 0;

  47550.     }

  47551.   }

  47552.   if( p->iSize<=BITVEC_NBIT ){

  47553.     return (p->u.aBitmap[i/BITVEC_SZELEM] & (1<<(i&(BITVEC_SZELEM-1))))!=0;

  47554.   } else{

  47555.     u32 h = BITVEC_HASH(i++);

  47556.     while( p->u.aHash[h] ){

  47557.       if( p->u.aHash[h]==i ) return 1;

  47558.       h = (h+1) % BITVEC_NINT;

  47559.     }

  47560.     return 0;

  47561.   }

  47562. }

  47563. SQLITE_PRIVATE int sqlite3BitvecTest(Bitvec *p, u32 i){

  47564.   return p!=0 && sqlite3BitvecTestNotNull(p,i);

  47565. }

  47566. 

  47567. /*

  47568. ** Set the i-th bit.  Return 0 on success and an error code if

  47569. ** anything goes wrong.

  47570. **

  47571. ** This routine might cause sub-bitmaps to be allocated.  Failing

  47572. ** to get the memory needed to hold the sub-bitmap is the only

  47573. ** that can go wrong with an insert, assuming p and i are valid.

  47574. **

  47575. ** The calling function must ensure that p is a valid Bitvec object

  47576. ** and that the value for "i" is within range of the Bitvec object.

  47577. ** Otherwise the behavior is undefined.

  47578. */

  47579. SQLITE_PRIVATE int sqlite3BitvecSet(Bitvec *p, u32 i){

  47580.   u32 h;

  47581.   if( p==0 ) return SQLITE_OK;

  47582.   assert( i>0 );

  47583.   assert( i<=p->iSize );

  47584.   i--;

  47585.   while((p->iSize > BITVEC_NBIT) && p->iDivisor) {

  47586.     u32 bin = i/p->iDivisor;

  47587.     i = i%p->iDivisor;

  47588.     if( p->u.apSub[bin]==0 ){

  47589.       p->u.apSub[bin] = sqlite3BitvecCreate( p->iDivisor );

  47590.       if( p->u.apSub[bin]==0 ) return SQLITE_NOMEM_BKPT;

  47591.     }

  47592.     p = p->u.apSub[bin];

  47593.   }

  47594.   if( p->iSize<=BITVEC_NBIT ){

  47595.     p->u.aBitmap[i/BITVEC_SZELEM] |= 1 << (i&(BITVEC_SZELEM-1));

  47596.     return SQLITE_OK;

  47597.   }

  47598.   h = BITVEC_HASH(i++);

  47599.   /* if there wasn't a hash collision, and this doesn't */

  47600.   /* completely fill the hash, then just add it without */

  47601.   /* worring about sub-dividing and re-hashing. */

  47602.   if( !p->u.aHash[h] ){

  47603.     if (p->nSet<(BITVEC_NINT-1)) {

  47604.       goto bitvec_set_end;

  47605.     } else {

  47606.       goto bitvec_set_rehash;

  47607.     }

  47608.   }

  47609.   /* there was a collision, check to see if it's already */

  47610.   /* in hash, if not, try to find a spot for it */

  47611.   do {

  47612.     if( p->u.aHash[h]==i ) return SQLITE_OK;

  47613.     h++;

  47614.     if( h>=BITVEC_NINT ) h = 0;

  47615.   } while( p->u.aHash[h] );

  47616.   /* we didn't find it in the hash.  h points to the first */

  47617.   /* available free spot. check to see if this is going to */

  47618.   /* make our hash too "full".  */

  47619. bitvec_set_rehash:

  47620.   if( p->nSet>=BITVEC_MXHASH ){

  47621.     unsigned int j;

  47622.     int rc;

  47623.     u32 *aiValues = sqlite3StackAllocRaw(0, sizeof(p->u.aHash));

  47624.     if( aiValues==0 ){

  47625.       return SQLITE_NOMEM_BKPT;

  47626.     }else{

  47627.       memcpy(aiValues, p->u.aHash, sizeof(p->u.aHash));

  47628.       memset(p->u.apSub, 0, sizeof(p->u.apSub));

  47629.       p->iDivisor = (p->iSize + BITVEC_NPTR - 1)/BITVEC_NPTR;

  47630.       rc = sqlite3BitvecSet(p, i);

  47631.       for(j=0; j<BITVEC_NINT; j++){

  47632.         if( aiValues[j] ) rc |= sqlite3BitvecSet(p, aiValues[j]);

  47633.       }

  47634.       sqlite3StackFree(0, aiValues);

  47635.       return rc;

  47636.     }

  47637.   }

  47638. bitvec_set_end:

  47639.   p->nSet++;

  47640.   p->u.aHash[h] = i;

  47641.   return SQLITE_OK;

  47642. }

  47643. 

  47644. /*

  47645. ** Clear the i-th bit.

  47646. **

  47647. ** pBuf must be a pointer to at least BITVEC_SZ bytes of temporary storage

  47648. ** that BitvecClear can use to rebuilt its hash table.

  47649. */

  47650. SQLITE_PRIVATE void sqlite3BitvecClear(Bitvec *p, u32 i, void *pBuf){

  47651.   if( p==0 ) return;

  47652.   assert( i>0 );

  47653.   i--;

  47654.   while( p->iDivisor ){

  47655.     u32 bin = i/p->iDivisor;

  47656.     i = i%p->iDivisor;

  47657.     p = p->u.apSub[bin];

  47658.     if (!p) {

  47659.       return;

  47660.     }

  47661.   }

  47662.   if( p->iSize<=BITVEC_NBIT ){

  47663.     p->u.aBitmap[i/BITVEC_SZELEM] &= ~(1 << (i&(BITVEC_SZELEM-1)));

  47664.   }else{

  47665.     unsigned int j;

  47666.     u32 *aiValues = pBuf;

  47667.     memcpy(aiValues, p->u.aHash, sizeof(p->u.aHash));

  47668.     memset(p->u.aHash, 0, sizeof(p->u.aHash));

  47669.     p->nSet = 0;

  47670.     for(j=0; j<BITVEC_NINT; j++){

  47671.       if( aiValues[j] && aiValues[j]!=(i+1) ){

  47672.         u32 h = BITVEC_HASH(aiValues[j]-1);

  47673.         p->nSet++;

  47674.         while( p->u.aHash[h] ){

  47675.           h++;

  47676.           if( h>=BITVEC_NINT ) h = 0;

  47677.         }

  47678.         p->u.aHash[h] = aiValues[j];

  47679.       }

  47680.     }

  47681.   }

  47682. }

  47683. 

  47684. /*

  47685. ** Destroy a bitmap object.  Reclaim all memory used.

  47686. */

  47687. SQLITE_PRIVATE void sqlite3BitvecDestroy(Bitvec *p){

  47688.   if( p==0 ) return;

  47689.   if( p->iDivisor ){

  47690.     unsigned int i;

  47691.     for(i=0; i<BITVEC_NPTR; i++){

  47692.       sqlite3BitvecDestroy(p->u.apSub[i]);

  47693.     }

  47694.   }

  47695.   sqlite3_free(p);

  47696. }

  47697. 

  47698. /*

  47699. ** Return the value of the iSize parameter specified when Bitvec *p

  47700. ** was created.

  47701. */

  47702. SQLITE_PRIVATE u32 sqlite3BitvecSize(Bitvec *p){

  47703.   return p->iSize;

  47704. }

  47705. 

  47706. #ifndef SQLITE_UNTESTABLE

  47707. /*

  47708. ** Let V[] be an array of unsigned characters sufficient to hold

  47709. ** up to N bits.  Let I be an integer between 0 and N.  0<=I<N.

  47710. ** Then the following macros can be used to set, clear, or test

  47711. ** individual bits within V.

  47712. */

  47713. #define SETBIT(V,I)      V[I>>3] |= (1<<(I&7))

  47714. #define CLEARBIT(V,I)    V[I>>3] &= ~(1<<(I&7))

  47715. #define TESTBIT(V,I)     (V[I>>3]&(1<<(I&7)))!=0

  47716. 

  47717. /*

  47718. ** This routine runs an extensive test of the Bitvec code.

  47719. **

  47720. ** The input is an array of integers that acts as a program

  47721. ** to test the Bitvec.  The integers are opcodes followed

  47722. ** by 0, 1, or 3 operands, depending on the opcode.  Another

  47723. ** opcode follows immediately after the last operand.

  47724. **

  47725. ** There are 6 opcodes numbered from 0 through 5.  0 is the

  47726. ** "halt" opcode and causes the test to end.

  47727. **

  47728. **    0          Halt and return the number of errors

  47729. **    1 N S X    Set N bits beginning with S and incrementing by X

  47730. **    2 N S X    Clear N bits beginning with S and incrementing by X

  47731. **    3 N        Set N randomly chosen bits

  47732. **    4 N        Clear N randomly chosen bits

  47733. **    5 N S X    Set N bits from S increment X in array only, not in bitvec

  47734. **

  47735. ** The opcodes 1 through 4 perform set and clear operations are performed

  47736. ** on both a Bitvec object and on a linear array of bits obtained from malloc.

  47737. ** Opcode 5 works on the linear array only, not on the Bitvec.

  47738. ** Opcode 5 is used to deliberately induce a fault in order to

  47739. ** confirm that error detection works.

  47740. **

  47741. ** At the conclusion of the test the linear array is compared

  47742. ** against the Bitvec object.  If there are any differences,

  47743. ** an error is returned.  If they are the same, zero is returned.

  47744. **

  47745. ** If a memory allocation error occurs, return -1.

  47746. */

  47747. SQLITE_PRIVATE int sqlite3BitvecBuiltinTest(int sz, int *aOp){

  47748.   Bitvec *pBitvec = 0;

  47749.   unsigned char *pV = 0;

  47750.   int rc = -1;

  47751.   int i, nx, pc, op;

  47752.   void *pTmpSpace;

  47753. 

  47754.   /* Allocate the Bitvec to be tested and a linear array of

  47755.   ** bits to act as the reference */

  47756.   pBitvec = sqlite3BitvecCreate( sz );

  47757.   pV = sqlite3MallocZero( (sz+7)/8 + 1 );

  47758.   pTmpSpace = sqlite3_malloc64(BITVEC_SZ);

  47759.   if( pBitvec==0 || pV==0 || pTmpSpace==0  ) goto bitvec_end;

  47760. 

  47761.   /* NULL pBitvec tests */

  47762.   sqlite3BitvecSet(0, 1);

  47763.   sqlite3BitvecClear(0, 1, pTmpSpace);

  47764. 

  47765.   /* Run the program */

  47766.   pc = 0;

  47767.   while( (op = aOp[pc])!=0 ){

  47768.     switch( op ){

  47769.       case 1:

  47770.       case 2:

  47771.       case 5: {

  47772.         nx = 4;

  47773.         i = aOp[pc+2] - 1;

  47774.         aOp[pc+2] += aOp[pc+3];

  47775.         break;

  47776.       }

  47777.       case 3:

  47778.       case 4: 

  47779.       default: {

  47780.         nx = 2;

  47781.         sqlite3_randomness(sizeof(i), &i);

  47782.         break;

  47783.       }

  47784.     }

  47785.     if( (--aOp[pc+1]) > 0 ) nx = 0;

  47786.     pc += nx;

  47787.     i = (i & 0x7fffffff)%sz;

  47788.     if( (op & 1)!=0 ){

  47789.       SETBIT(pV, (i+1));

  47790.       if( op!=5 ){

  47791.         if( sqlite3BitvecSet(pBitvec, i+1) ) goto bitvec_end;

  47792.       }

  47793.     }else{

  47794.       CLEARBIT(pV, (i+1));

  47795.       sqlite3BitvecClear(pBitvec, i+1, pTmpSpace);

  47796.     }

  47797.   }

  47798. 

  47799.   /* Test to make sure the linear array exactly matches the

  47800.   ** Bitvec object.  Start with the assumption that they do

  47801.   ** match (rc==0).  Change rc to non-zero if a discrepancy

  47802.   ** is found.

  47803.   */

  47804.   rc = sqlite3BitvecTest(0,0) + sqlite3BitvecTest(pBitvec, sz+1)

  47805.           + sqlite3BitvecTest(pBitvec, 0)

  47806.           + (sqlite3BitvecSize(pBitvec) - sz);

  47807.   for(i=1; i<=sz; i++){

  47808.     if(  (TESTBIT(pV,i))!=sqlite3BitvecTest(pBitvec,i) ){

  47809.       rc = i;

  47810.       break;

  47811.     }

  47812.   }

  47813. 

  47814.   /* Free allocated structure */

  47815. bitvec_end:

  47816.   sqlite3_free(pTmpSpace);

  47817.   sqlite3_free(pV);

  47818.   sqlite3BitvecDestroy(pBitvec);

  47819.   return rc;

  47820. }

  47821. #endif /* SQLITE_UNTESTABLE */

  47822. 

  47823. /************** End of bitvec.c **********************************************/

  47824. /************** Begin file pcache.c ******************************************/

  47825. /*

  47826. ** 2008 August 05

  47827. **

  47828. ** The author disclaims copyright to this source code.  In place of

  47829. ** a legal notice, here is a blessing:

  47830. **

  47831. **    May you do good and not evil.

  47832. **    May you find forgiveness for yourself and forgive others.

  47833. **    May you share freely, never taking more than you give.

  47834. **

  47835. *************************************************************************

  47836. ** This file implements that page cache.

  47837. */

  47838. /* #include "sqliteInt.h" */

  47839. 

  47840. /*

  47841. ** A complete page cache is an instance of this structure.  Every

  47842. ** entry in the cache holds a single page of the database file.  The

  47843. ** btree layer only operates on the cached copy of the database pages.

  47844. **

  47845. ** A page cache entry is "clean" if it exactly matches what is currently

  47846. ** on disk.  A page is "dirty" if it has been modified and needs to be

  47847. ** persisted to disk.

  47848. **

  47849. ** pDirty, pDirtyTail, pSynced:

  47850. **   All dirty pages are linked into the doubly linked list using

  47851. **   PgHdr.pDirtyNext and pDirtyPrev. The list is maintained in LRU order

  47852. **   such that p was added to the list more recently than p->pDirtyNext.

  47853. **   PCache.pDirty points to the first (newest) element in the list and

  47854. **   pDirtyTail to the last (oldest).

  47855. **

  47856. **   The PCache.pSynced variable is used to optimize searching for a dirty

  47857. **   page to eject from the cache mid-transaction. It is better to eject

  47858. **   a page that does not require a journal sync than one that does. 

  47859. **   Therefore, pSynced is maintained so that it *almost* always points

  47860. **   to either the oldest page in the pDirty/pDirtyTail list that has a

  47861. **   clear PGHDR_NEED_SYNC flag or to a page that is older than this one

  47862. **   (so that the right page to eject can be found by following pDirtyPrev

  47863. **   pointers).

  47864. */

  47865. struct PCache {

  47866.   PgHdr *pDirty, *pDirtyTail;         /* List of dirty pages in LRU order */

  47867.   PgHdr *pSynced;                     /* Last synced page in dirty page list */

  47868.   int nRefSum;                        /* Sum of ref counts over all pages */

  47869.   int szCache;                        /* Configured cache size */

  47870.   int szSpill;                        /* Size before spilling occurs */

  47871.   int szPage;                         /* Size of every page in this cache */

  47872.   int szExtra;                        /* Size of extra space for each page */

  47873.   u8 bPurgeable;                      /* True if pages are on backing store */

  47874.   u8 eCreate;                         /* eCreate value for for xFetch() */

  47875.   int (*xStress)(void*,PgHdr*);       /* Call to try make a page clean */

  47876.   void *pStress;                      /* Argument to xStress */

  47877.   sqlite3_pcache *pCache;             /* Pluggable cache module */

  47878. };

  47879. 

  47880. /********************************** Test and Debug Logic **********************/

  47881. /*

  47882. ** Debug tracing macros.  Enable by by changing the "0" to "1" and

  47883. ** recompiling.

  47884. **

  47885. ** When sqlite3PcacheTrace is 1, single line trace messages are issued.

  47886. ** When sqlite3PcacheTrace is 2, a dump of the pcache showing all cache entries

  47887. ** is displayed for many operations, resulting in a lot of output.

  47888. */

  47889. #if defined(SQLITE_DEBUG) && 0

  47890.   int sqlite3PcacheTrace = 2;       /* 0: off  1: simple  2: cache dumps */

  47891.   int sqlite3PcacheMxDump = 9999;   /* Max cache entries for pcacheDump() */

  47892. # define pcacheTrace(X) if(sqlite3PcacheTrace){sqlite3DebugPrintf X;}

  47893.   void pcacheDump(PCache *pCache){

  47894.     int N;

  47895.     int i, j;

  47896.     sqlite3_pcache_page *pLower;

  47897.     PgHdr *pPg;

  47898.     unsigned char *a;

  47899.   

  47900.     if( sqlite3PcacheTrace<2 ) return;

  47901.     if( pCache->pCache==0 ) return;

  47902.     N = sqlite3PcachePagecount(pCache);

  47903.     if( N>sqlite3PcacheMxDump ) N = sqlite3PcacheMxDump;

  47904.     for(i=1; i<=N; i++){

  47905.        pLower = sqlite3GlobalConfig.pcache2.xFetch(pCache->pCache, i, 0);

  47906.        if( pLower==0 ) continue;

  47907.        pPg = (PgHdr*)pLower->pExtra;

  47908.        printf("%3d: nRef %2d flgs %02x data ", i, pPg->nRef, pPg->flags);

  47909.        a = (unsigned char *)pLower->pBuf;

  47910.        for(j=0; j<12; j++) printf("%02x", a[j]);

  47911.        printf("\n");

  47912.        if( pPg->pPage==0 ){

  47913.          sqlite3GlobalConfig.pcache2.xUnpin(pCache->pCache, pLower, 0);

  47914.        }

  47915.     }

  47916.   }

  47917.   #else

  47918. # define pcacheTrace(X)

  47919. # define pcacheDump(X)

  47920. #endif

  47921. 

  47922. /*

  47923. ** Check invariants on a PgHdr entry.  Return true if everything is OK.

  47924. ** Return false if any invariant is violated.

  47925. **

  47926. ** This routine is for use inside of assert() statements only.  For

  47927. ** example:

  47928. **

  47929. **          assert( sqlite3PcachePageSanity(pPg) );

  47930. */

  47931. #ifdef SQLITE_DEBUG

  47932. SQLITE_PRIVATE int sqlite3PcachePageSanity(PgHdr *pPg){

  47933.   PCache *pCache;

  47934.   assert( pPg!=0 );

  47935.   assert( pPg->pgno>0 || pPg->pPager==0 );    /* Page number is 1 or more */

  47936.   pCache = pPg->pCache;

  47937.   assert( pCache!=0 );      /* Every page has an associated PCache */

  47938.   if( pPg->flags & PGHDR_CLEAN ){

  47939.     assert( (pPg->flags & PGHDR_DIRTY)==0 );/* Cannot be both CLEAN and DIRTY */

  47940.     assert( pCache->pDirty!=pPg );          /* CLEAN pages not on dirty list */

  47941.     assert( pCache->pDirtyTail!=pPg );

  47942.   }

  47943.   /* WRITEABLE pages must also be DIRTY */

  47944.   if( pPg->flags & PGHDR_WRITEABLE ){

  47945.     assert( pPg->flags & PGHDR_DIRTY );     /* WRITEABLE implies DIRTY */

  47946.   }

  47947.   /* NEED_SYNC can be set independently of WRITEABLE.  This can happen,

  47948.   ** for example, when using the sqlite3PagerDontWrite() optimization:

  47949.   **    (1)  Page X is journalled, and gets WRITEABLE and NEED_SEEK.

  47950.   **    (2)  Page X moved to freelist, WRITEABLE is cleared

  47951.   **    (3)  Page X reused, WRITEABLE is set again

  47952.   ** If NEED_SYNC had been cleared in step 2, then it would not be reset

  47953.   ** in step 3, and page might be written into the database without first

  47954.   ** syncing the rollback journal, which might cause corruption on a power

  47955.   ** loss.

  47956.   **

  47957.   ** Another example is when the database page size is smaller than the

  47958.   ** disk sector size.  When any page of a sector is journalled, all pages

  47959.   ** in that sector are marked NEED_SYNC even if they are still CLEAN, just

  47960.   ** in case they are later modified, since all pages in the same sector

  47961.   ** must be journalled and synced before any of those pages can be safely

  47962.   ** written.

  47963.   */

  47964.   return 1;

  47965. }

  47966. #endif /* SQLITE_DEBUG */

  47967. 

  47968. 

  47969. /********************************** Linked List Management ********************/

  47970. 

  47971. /* Allowed values for second argument to pcacheManageDirtyList() */

  47972. #define PCACHE_DIRTYLIST_REMOVE   1    /* Remove pPage from dirty list */

  47973. #define PCACHE_DIRTYLIST_ADD      2    /* Add pPage to the dirty list */

  47974. #define PCACHE_DIRTYLIST_FRONT    3    /* Move pPage to the front of the list */

  47975. 

  47976. /*

  47977. ** Manage pPage's participation on the dirty list.  Bits of the addRemove

  47978. ** argument determines what operation to do.  The 0x01 bit means first

  47979. ** remove pPage from the dirty list.  The 0x02 means add pPage back to

  47980. ** the dirty list.  Doing both moves pPage to the front of the dirty list.

  47981. */

  47982. static void pcacheManageDirtyList(PgHdr *pPage, u8 addRemove){

  47983.   PCache *p = pPage->pCache;

  47984. 

  47985.   pcacheTrace(("%p.DIRTYLIST.%s %d\n", p,

  47986.                 addRemove==1 ? "REMOVE" : addRemove==2 ? "ADD" : "FRONT",

  47987.                 pPage->pgno));

  47988.   if( addRemove & PCACHE_DIRTYLIST_REMOVE ){

  47989.     assert( pPage->pDirtyNext || pPage==p->pDirtyTail );

  47990.     assert( pPage->pDirtyPrev || pPage==p->pDirty );

  47991.   

  47992.     /* Update the PCache1.pSynced variable if necessary. */

  47993.     if( p->pSynced==pPage ){

  47994.       p->pSynced = pPage->pDirtyPrev;

  47995.     }

  47996.   

  47997.     if( pPage->pDirtyNext ){

  47998.       pPage->pDirtyNext->pDirtyPrev = pPage->pDirtyPrev;

  47999.     }else{

  48000.       assert( pPage==p->pDirtyTail );

  48001.       p->pDirtyTail = pPage->pDirtyPrev;

  48002.     }

  48003.     if( pPage->pDirtyPrev ){

  48004.       pPage->pDirtyPrev->pDirtyNext = pPage->pDirtyNext;

  48005.     }else{

  48006.       /* If there are now no dirty pages in the cache, set eCreate to 2. 

  48007.       ** This is an optimization that allows sqlite3PcacheFetch() to skip

  48008.       ** searching for a dirty page to eject from the cache when it might

  48009.       ** otherwise have to.  */

  48010.       assert( pPage==p->pDirty );

  48011.       p->pDirty = pPage->pDirtyNext;

  48012.       assert( p->bPurgeable || p->eCreate==2 );

  48013.       if( p->pDirty==0 ){         /*OPTIMIZATION-IF-TRUE*/

  48014.         assert( p->bPurgeable==0 || p->eCreate==1 );

  48015.         p->eCreate = 2;

  48016.       }

  48017.     }

  48018.   }

  48019.   if( addRemove & PCACHE_DIRTYLIST_ADD ){

  48020.     pPage->pDirtyPrev = 0;

  48021.     pPage->pDirtyNext = p->pDirty;

  48022.     if( pPage->pDirtyNext ){

  48023.       assert( pPage->pDirtyNext->pDirtyPrev==0 );

  48024.       pPage->pDirtyNext->pDirtyPrev = pPage;

  48025.     }else{

  48026.       p->pDirtyTail = pPage;

  48027.       if( p->bPurgeable ){

  48028.         assert( p->eCreate==2 );

  48029.         p->eCreate = 1;

  48030.       }

  48031.     }

  48032.     p->pDirty = pPage;

  48033. 

  48034.     /* If pSynced is NULL and this page has a clear NEED_SYNC flag, set

  48035.     ** pSynced to point to it. Checking the NEED_SYNC flag is an 

  48036.     ** optimization, as if pSynced points to a page with the NEED_SYNC

  48037.     ** flag set sqlite3PcacheFetchStress() searches through all newer 

  48038.     ** entries of the dirty-list for a page with NEED_SYNC clear anyway.  */

  48039.     if( !p->pSynced 

  48040.      && 0==(pPage->flags&PGHDR_NEED_SYNC)   /*OPTIMIZATION-IF-FALSE*/

  48041.     ){

  48042.       p->pSynced = pPage;

  48043.     }

  48044.   }

  48045.   pcacheDump(p);

  48046. }

  48047. 

  48048. /*

  48049. ** Wrapper around the pluggable caches xUnpin method. If the cache is

  48050. ** being used for an in-memory database, this function is a no-op.

  48051. */

  48052. static void pcacheUnpin(PgHdr *p){

  48053.   if( p->pCache->bPurgeable ){

  48054.     pcacheTrace(("%p.UNPIN %d\n", p->pCache, p->pgno));

  48055.     sqlite3GlobalConfig.pcache2.xUnpin(p->pCache->pCache, p->pPage, 0);

  48056.     pcacheDump(p->pCache);

  48057.   }

  48058. }

  48059. 

  48060. /*

  48061. ** Compute the number of pages of cache requested.   p->szCache is the

  48062. ** cache size requested by the "PRAGMA cache_size" statement.

  48063. */

  48064. static int numberOfCachePages(PCache *p){

  48065.   if( p->szCache>=0 ){

  48066.     /* IMPLEMENTATION-OF: R-42059-47211 If the argument N is positive then the

  48067.     ** suggested cache size is set to N. */

  48068.     return p->szCache;

  48069.   }else{

  48070.     /* IMPLEMANTATION-OF: R-59858-46238 If the argument N is negative, then the

  48071.     ** number of cache pages is adjusted to be a number of pages that would

  48072.     ** use approximately abs(N*1024) bytes of memory based on the current

  48073.     ** page size. */

  48074.     return (int)((-1024*(i64)p->szCache)/(p->szPage+p->szExtra));

  48075.   }

  48076. }

  48077. 

  48078. /*************************************************** General Interfaces ******

  48079. **

  48080. ** Initialize and shutdown the page cache subsystem. Neither of these 

  48081. ** functions are threadsafe.

  48082. */

  48083. SQLITE_PRIVATE int sqlite3PcacheInitialize(void){

  48084.   if( sqlite3GlobalConfig.pcache2.xInit==0 ){

  48085.     /* IMPLEMENTATION-OF: R-26801-64137 If the xInit() method is NULL, then the

  48086.     ** built-in default page cache is used instead of the application defined

  48087.     ** page cache. */

  48088.     sqlite3PCacheSetDefault();

  48089.   }

  48090.   return sqlite3GlobalConfig.pcache2.xInit(sqlite3GlobalConfig.pcache2.pArg);

  48091. }

  48092. SQLITE_PRIVATE void sqlite3PcacheShutdown(void){

  48093.   if( sqlite3GlobalConfig.pcache2.xShutdown ){

  48094.     /* IMPLEMENTATION-OF: R-26000-56589 The xShutdown() method may be NULL. */

  48095.     sqlite3GlobalConfig.pcache2.xShutdown(sqlite3GlobalConfig.pcache2.pArg);

  48096.   }

  48097. }

  48098. 

  48099. /*

  48100. ** Return the size in bytes of a PCache object.

  48101. */

  48102. SQLITE_PRIVATE int sqlite3PcacheSize(void){ return sizeof(PCache); }

  48103. 

  48104. /*

  48105. ** Create a new PCache object. Storage space to hold the object

  48106. ** has already been allocated and is passed in as the p pointer. 

  48107. ** The caller discovers how much space needs to be allocated by 

  48108. ** calling sqlite3PcacheSize().

  48109. **

  48110. ** szExtra is some extra space allocated for each page.  The first

  48111. ** 8 bytes of the extra space will be zeroed as the page is allocated,

  48112. ** but remaining content will be uninitialized.  Though it is opaque

  48113. ** to this module, the extra space really ends up being the MemPage

  48114. ** structure in the pager.

  48115. */

  48116. SQLITE_PRIVATE int sqlite3PcacheOpen(

  48117.   int szPage,                  /* Size of every page */

  48118.   int szExtra,                 /* Extra space associated with each page */

  48119.   int bPurgeable,              /* True if pages are on backing store */

  48120.   int (*xStress)(void*,PgHdr*),/* Call to try to make pages clean */

  48121.   void *pStress,               /* Argument to xStress */

  48122.   PCache *p                    /* Preallocated space for the PCache */

  48123. ){

  48124.   memset(p, 0, sizeof(PCache));

  48125.   p->szPage = 1;

  48126.   p->szExtra = szExtra;

  48127.   assert( szExtra>=8 );  /* First 8 bytes will be zeroed */

  48128.   p->bPurgeable = bPurgeable;

  48129.   p->eCreate = 2;

  48130.   p->xStress = xStress;

  48131.   p->pStress = pStress;

  48132.   p->szCache = 100;

  48133.   p->szSpill = 1;

  48134.   pcacheTrace(("%p.OPEN szPage %d bPurgeable %d\n",p,szPage,bPurgeable));

  48135.   return sqlite3PcacheSetPageSize(p, szPage);

  48136. }

  48137. 

  48138. /*

  48139. ** Change the page size for PCache object. The caller must ensure that there

  48140. ** are no outstanding page references when this function is called.

  48141. */

  48142. SQLITE_PRIVATE int sqlite3PcacheSetPageSize(PCache *pCache, int szPage){

  48143.   assert( pCache->nRefSum==0 && pCache->pDirty==0 );

  48144.   if( pCache->szPage ){

  48145.     sqlite3_pcache *pNew;

  48146.     pNew = sqlite3GlobalConfig.pcache2.xCreate(

  48147.                 szPage, pCache->szExtra + ROUND8(sizeof(PgHdr)),

  48148.                 pCache->bPurgeable

  48149.     );

  48150.     if( pNew==0 ) return SQLITE_NOMEM_BKPT;

  48151.     sqlite3GlobalConfig.pcache2.xCachesize(pNew, numberOfCachePages(pCache));

  48152.     if( pCache->pCache ){

  48153.       sqlite3GlobalConfig.pcache2.xDestroy(pCache->pCache);

  48154.     }

  48155.     pCache->pCache = pNew;

  48156.     pCache->szPage = szPage;

  48157.     pcacheTrace(("%p.PAGESIZE %d\n",pCache,szPage));

  48158.   }

  48159.   return SQLITE_OK;

  48160. }

  48161. 

  48162. /*

  48163. ** Try to obtain a page from the cache.

  48164. **

  48165. ** This routine returns a pointer to an sqlite3_pcache_page object if

  48166. ** such an object is already in cache, or if a new one is created.

  48167. ** This routine returns a NULL pointer if the object was not in cache

  48168. ** and could not be created.

  48169. **

  48170. ** The createFlags should be 0 to check for existing pages and should

  48171. ** be 3 (not 1, but 3) to try to create a new page.

  48172. **

  48173. ** If the createFlag is 0, then NULL is always returned if the page

  48174. ** is not already in the cache.  If createFlag is 1, then a new page

  48175. ** is created only if that can be done without spilling dirty pages

  48176. ** and without exceeding the cache size limit.

  48177. **

  48178. ** The caller needs to invoke sqlite3PcacheFetchFinish() to properly

  48179. ** initialize the sqlite3_pcache_page object and convert it into a

  48180. ** PgHdr object.  The sqlite3PcacheFetch() and sqlite3PcacheFetchFinish()

  48181. ** routines are split this way for performance reasons. When separated

  48182. ** they can both (usually) operate without having to push values to

  48183. ** the stack on entry and pop them back off on exit, which saves a

  48184. ** lot of pushing and popping.

  48185. */

  48186. SQLITE_PRIVATE sqlite3_pcache_page *sqlite3PcacheFetch(

  48187.   PCache *pCache,       /* Obtain the page from this cache */

  48188.   Pgno pgno,            /* Page number to obtain */

  48189.   int createFlag        /* If true, create page if it does not exist already */

  48190. ){

  48191.   int eCreate;

  48192.   sqlite3_pcache_page *pRes;

  48193. 

  48194.   assert( pCache!=0 );

  48195.   assert( pCache->pCache!=0 );

  48196.   assert( createFlag==3 || createFlag==0 );

  48197.   assert( pCache->eCreate==((pCache->bPurgeable && pCache->pDirty) ? 1 : 2) );

  48198. 

  48199.   /* eCreate defines what to do if the page does not exist.

  48200.   **    0     Do not allocate a new page.  (createFlag==0)

  48201.   **    1     Allocate a new page if doing so is inexpensive.

  48202.   **          (createFlag==1 AND bPurgeable AND pDirty)

  48203.   **    2     Allocate a new page even it doing so is difficult.

  48204.   **          (createFlag==1 AND !(bPurgeable AND pDirty)

  48205.   */

  48206.   eCreate = createFlag & pCache->eCreate;

  48207.   assert( eCreate==0 || eCreate==1 || eCreate==2 );

  48208.   assert( createFlag==0 || pCache->eCreate==eCreate );

  48209.   assert( createFlag==0 || eCreate==1+(!pCache->bPurgeable||!pCache->pDirty) );

  48210.   pRes = sqlite3GlobalConfig.pcache2.xFetch(pCache->pCache, pgno, eCreate);

  48211.   pcacheTrace(("%p.FETCH %d%s (result: %p)\n",pCache,pgno,

  48212.                createFlag?" create":"",pRes));

  48213.   return pRes;

  48214. }

  48215. 

  48216. /*

  48217. ** If the sqlite3PcacheFetch() routine is unable to allocate a new

  48218. ** page because no clean pages are available for reuse and the cache

  48219. ** size limit has been reached, then this routine can be invoked to 

  48220. ** try harder to allocate a page.  This routine might invoke the stress

  48221. ** callback to spill dirty pages to the journal.  It will then try to

  48222. ** allocate the new page and will only fail to allocate a new page on

  48223. ** an OOM error.

  48224. **

  48225. ** This routine should be invoked only after sqlite3PcacheFetch() fails.

  48226. */

  48227. SQLITE_PRIVATE int sqlite3PcacheFetchStress(

  48228.   PCache *pCache,                 /* Obtain the page from this cache */

  48229.   Pgno pgno,                      /* Page number to obtain */

  48230.   sqlite3_pcache_page **ppPage    /* Write result here */

  48231. ){

  48232.   PgHdr *pPg;

  48233.   if( pCache->eCreate==2 ) return 0;

  48234. 

  48235.   if( sqlite3PcachePagecount(pCache)>pCache->szSpill ){

  48236.     /* Find a dirty page to write-out and recycle. First try to find a 

  48237.     ** page that does not require a journal-sync (one with PGHDR_NEED_SYNC

  48238.     ** cleared), but if that is not possible settle for any other 

  48239.     ** unreferenced dirty page.

  48240.     **

  48241.     ** If the LRU page in the dirty list that has a clear PGHDR_NEED_SYNC

  48242.     ** flag is currently referenced, then the following may leave pSynced

  48243.     ** set incorrectly (pointing to other than the LRU page with NEED_SYNC

  48244.     ** cleared). This is Ok, as pSynced is just an optimization.  */

  48245.     for(pPg=pCache->pSynced; 

  48246.         pPg && (pPg->nRef || (pPg->flags&PGHDR_NEED_SYNC)); 

  48247.         pPg=pPg->pDirtyPrev

  48248.     );

  48249.     pCache->pSynced = pPg;

  48250.     if( !pPg ){

  48251.       for(pPg=pCache->pDirtyTail; pPg && pPg->nRef; pPg=pPg->pDirtyPrev);

  48252.     }

  48253.     if( pPg ){

  48254.       int rc;

  48255. #ifdef SQLITE_LOG_CACHE_SPILL

  48256.       sqlite3_log(SQLITE_FULL, 

  48257.                   "spill page %d making room for %d - cache used: %d/%d",

  48258.                   pPg->pgno, pgno,

  48259.                   sqlite3GlobalConfig.pcache2.xPagecount(pCache->pCache),

  48260.                 numberOfCachePages(pCache));

  48261. #endif

  48262.       pcacheTrace(("%p.SPILL %d\n",pCache,pPg->pgno));

  48263.       rc = pCache->xStress(pCache->pStress, pPg);

  48264.       pcacheDump(pCache);

  48265.       if( rc!=SQLITE_OK && rc!=SQLITE_BUSY ){

  48266.         return rc;

  48267.       }

  48268.     }

  48269.   }

  48270.   *ppPage = sqlite3GlobalConfig.pcache2.xFetch(pCache->pCache, pgno, 2);

  48271.   return *ppPage==0 ? SQLITE_NOMEM_BKPT : SQLITE_OK;

  48272. }

  48273. 

  48274. /*

  48275. ** This is a helper routine for sqlite3PcacheFetchFinish()

  48276. **

  48277. ** In the uncommon case where the page being fetched has not been

  48278. ** initialized, this routine is invoked to do the initialization.

  48279. ** This routine is broken out into a separate function since it

  48280. ** requires extra stack manipulation that can be avoided in the common

  48281. ** case.

  48282. */

  48283. static SQLITE_NOINLINE PgHdr *pcacheFetchFinishWithInit(

  48284.   PCache *pCache,             /* Obtain the page from this cache */

  48285.   Pgno pgno,                  /* Page number obtained */

  48286.   sqlite3_pcache_page *pPage  /* Page obtained by prior PcacheFetch() call */

  48287. ){

  48288.   PgHdr *pPgHdr;

  48289.   assert( pPage!=0 );

  48290.   pPgHdr = (PgHdr*)pPage->pExtra;

  48291.   assert( pPgHdr->pPage==0 );

  48292.   memset(&pPgHdr->pDirty, 0, sizeof(PgHdr) - offsetof(PgHdr,pDirty));

  48293.   pPgHdr->pPage = pPage;

  48294.   pPgHdr->pData = pPage->pBuf;

  48295.   pPgHdr->pExtra = (void *)&pPgHdr[1];

  48296.   memset(pPgHdr->pExtra, 0, 8);

  48297.   pPgHdr->pCache = pCache;

  48298.   pPgHdr->pgno = pgno;

  48299.   pPgHdr->flags = PGHDR_CLEAN;

  48300.   return sqlite3PcacheFetchFinish(pCache,pgno,pPage);

  48301. }

  48302. 

  48303. /*

  48304. ** This routine converts the sqlite3_pcache_page object returned by

  48305. ** sqlite3PcacheFetch() into an initialized PgHdr object.  This routine

  48306. ** must be called after sqlite3PcacheFetch() in order to get a usable

  48307. ** result.

  48308. */

  48309. SQLITE_PRIVATE PgHdr *sqlite3PcacheFetchFinish(

  48310.   PCache *pCache,             /* Obtain the page from this cache */

  48311.   Pgno pgno,                  /* Page number obtained */

  48312.   sqlite3_pcache_page *pPage  /* Page obtained by prior PcacheFetch() call */

  48313. ){

  48314.   PgHdr *pPgHdr;

  48315. 

  48316.   assert( pPage!=0 );

  48317.   pPgHdr = (PgHdr *)pPage->pExtra;

  48318. 

  48319.   if( !pPgHdr->pPage ){

  48320.     return pcacheFetchFinishWithInit(pCache, pgno, pPage);

  48321.   }

  48322.   pCache->nRefSum++;

  48323.   pPgHdr->nRef++;

  48324.   assert( sqlite3PcachePageSanity(pPgHdr) );

  48325.   return pPgHdr;

  48326. }

  48327. 

  48328. /*

  48329. ** Decrement the reference count on a page. If the page is clean and the

  48330. ** reference count drops to 0, then it is made eligible for recycling.

  48331. */

  48332. SQLITE_PRIVATE void SQLITE_NOINLINE sqlite3PcacheRelease(PgHdr *p){

  48333.   assert( p->nRef>0 );

  48334.   p->pCache->nRefSum--;

  48335.   if( (--p->nRef)==0 ){

  48336.     if( p->flags&PGHDR_CLEAN ){

  48337.       pcacheUnpin(p);

  48338.     }else{

  48339.       pcacheManageDirtyList(p, PCACHE_DIRTYLIST_FRONT);

  48340.     }

  48341.   }

  48342. }

  48343. 

  48344. /*

  48345. ** Increase the reference count of a supplied page by 1.

  48346. */

  48347. SQLITE_PRIVATE void sqlite3PcacheRef(PgHdr *p){

  48348.   assert(p->nRef>0);

  48349.   assert( sqlite3PcachePageSanity(p) );

  48350.   p->nRef++;

  48351.   p->pCache->nRefSum++;

  48352. }

  48353. 

  48354. /*

  48355. ** Drop a page from the cache. There must be exactly one reference to the

  48356. ** page. This function deletes that reference, so after it returns the

  48357. ** page pointed to by p is invalid.

  48358. */

  48359. SQLITE_PRIVATE void sqlite3PcacheDrop(PgHdr *p){

  48360.   assert( p->nRef==1 );

  48361.   assert( sqlite3PcachePageSanity(p) );

  48362.   if( p->flags&PGHDR_DIRTY ){

  48363.     pcacheManageDirtyList(p, PCACHE_DIRTYLIST_REMOVE);

  48364.   }

  48365.   p->pCache->nRefSum--;

  48366.   sqlite3GlobalConfig.pcache2.xUnpin(p->pCache->pCache, p->pPage, 1);

  48367. }

  48368. 

  48369. /*

  48370. ** Make sure the page is marked as dirty. If it isn't dirty already,

  48371. ** make it so.

  48372. */

  48373. SQLITE_PRIVATE void sqlite3PcacheMakeDirty(PgHdr *p){

  48374.   assert( p->nRef>0 );

  48375.   assert( sqlite3PcachePageSanity(p) );

  48376.   if( p->flags & (PGHDR_CLEAN|PGHDR_DONT_WRITE) ){    /*OPTIMIZATION-IF-FALSE*/

  48377.     p->flags &= ~PGHDR_DONT_WRITE;

  48378.     if( p->flags & PGHDR_CLEAN ){

  48379.       p->flags ^= (PGHDR_DIRTY|PGHDR_CLEAN);

  48380.       pcacheTrace(("%p.DIRTY %d\n",p->pCache,p->pgno));

  48381.       assert( (p->flags & (PGHDR_DIRTY|PGHDR_CLEAN))==PGHDR_DIRTY );

  48382.       pcacheManageDirtyList(p, PCACHE_DIRTYLIST_ADD);

  48383.     }

  48384.     assert( sqlite3PcachePageSanity(p) );

  48385.   }

  48386. }

  48387. 

  48388. /*

  48389. ** Make sure the page is marked as clean. If it isn't clean already,

  48390. ** make it so.

  48391. */

  48392. SQLITE_PRIVATE void sqlite3PcacheMakeClean(PgHdr *p){

  48393.   assert( sqlite3PcachePageSanity(p) );

  48394.   assert( (p->flags & PGHDR_DIRTY)!=0 );

  48395.   assert( (p->flags & PGHDR_CLEAN)==0 );

  48396.   pcacheManageDirtyList(p, PCACHE_DIRTYLIST_REMOVE);

  48397.   p->flags &= ~(PGHDR_DIRTY|PGHDR_NEED_SYNC|PGHDR_WRITEABLE);

  48398.   p->flags |= PGHDR_CLEAN;

  48399.   pcacheTrace(("%p.CLEAN %d\n",p->pCache,p->pgno));

  48400.   assert( sqlite3PcachePageSanity(p) );

  48401.   if( p->nRef==0 ){

  48402.     pcacheUnpin(p);

  48403.   }

  48404. }

  48405. 

  48406. /*

  48407. ** Make every page in the cache clean.

  48408. */

  48409. SQLITE_PRIVATE void sqlite3PcacheCleanAll(PCache *pCache){

  48410.   PgHdr *p;

  48411.   pcacheTrace(("%p.CLEAN-ALL\n",pCache));

  48412.   while( (p = pCache->pDirty)!=0 ){

  48413.     sqlite3PcacheMakeClean(p);

  48414.   }

  48415. }

  48416. 

  48417. /*

  48418. ** Clear the PGHDR_NEED_SYNC and PGHDR_WRITEABLE flag from all dirty pages.

  48419. */

  48420. SQLITE_PRIVATE void sqlite3PcacheClearWritable(PCache *pCache){

  48421.   PgHdr *p;

  48422.   pcacheTrace(("%p.CLEAR-WRITEABLE\n",pCache));

  48423.   for(p=pCache->pDirty; p; p=p->pDirtyNext){

  48424.     p->flags &= ~(PGHDR_NEED_SYNC|PGHDR_WRITEABLE);

  48425.   }

  48426.   pCache->pSynced = pCache->pDirtyTail;

  48427. }

  48428. 

  48429. /*

  48430. ** Clear the PGHDR_NEED_SYNC flag from all dirty pages.

  48431. */

  48432. SQLITE_PRIVATE void sqlite3PcacheClearSyncFlags(PCache *pCache){

  48433.   PgHdr *p;

  48434.   for(p=pCache->pDirty; p; p=p->pDirtyNext){

  48435.     p->flags &= ~PGHDR_NEED_SYNC;

  48436.   }

  48437.   pCache->pSynced = pCache->pDirtyTail;

  48438. }

  48439. 

  48440. /*

  48441. ** Change the page number of page p to newPgno. 

  48442. */

  48443. SQLITE_PRIVATE void sqlite3PcacheMove(PgHdr *p, Pgno newPgno){

  48444.   PCache *pCache = p->pCache;

  48445.   assert( p->nRef>0 );

  48446.   assert( newPgno>0 );

  48447.   assert( sqlite3PcachePageSanity(p) );

  48448.   pcacheTrace(("%p.MOVE %d -> %d\n",pCache,p->pgno,newPgno));

  48449.   sqlite3GlobalConfig.pcache2.xRekey(pCache->pCache, p->pPage, p->pgno,newPgno);

  48450.   p->pgno = newPgno;

  48451.   if( (p->flags&PGHDR_DIRTY) && (p->flags&PGHDR_NEED_SYNC) ){

  48452.     pcacheManageDirtyList(p, PCACHE_DIRTYLIST_FRONT);

  48453.   }

  48454. }

  48455. 

  48456. /*

  48457. ** Drop every cache entry whose page number is greater than "pgno". The

  48458. ** caller must ensure that there are no outstanding references to any pages

  48459. ** other than page 1 with a page number greater than pgno.

  48460. **

  48461. ** If there is a reference to page 1 and the pgno parameter passed to this

  48462. ** function is 0, then the data area associated with page 1 is zeroed, but

  48463. ** the page object is not dropped.

  48464. */

  48465. SQLITE_PRIVATE void sqlite3PcacheTruncate(PCache *pCache, Pgno pgno){

  48466.   if( pCache->pCache ){

  48467.     PgHdr *p;

  48468.     PgHdr *pNext;

  48469.     pcacheTrace(("%p.TRUNCATE %d\n",pCache,pgno));

  48470.     for(p=pCache->pDirty; p; p=pNext){

  48471.       pNext = p->pDirtyNext;

  48472.       /* This routine never gets call with a positive pgno except right

  48473.       ** after sqlite3PcacheCleanAll().  So if there are dirty pages,

  48474.       ** it must be that pgno==0.

  48475.       */

  48476.       assert( p->pgno>0 );

  48477.       if( p->pgno>pgno ){

  48478.         assert( p->flags&PGHDR_DIRTY );

  48479.         sqlite3PcacheMakeClean(p);

  48480.       }

  48481.     }

  48482.     if( pgno==0 && pCache->nRefSum ){

  48483.       sqlite3_pcache_page *pPage1;

  48484.       pPage1 = sqlite3GlobalConfig.pcache2.xFetch(pCache->pCache,1,0);

  48485.       if( ALWAYS(pPage1) ){  /* Page 1 is always available in cache, because

  48486.                              ** pCache->nRefSum>0 */

  48487.         memset(pPage1->pBuf, 0, pCache->szPage);

  48488.         pgno = 1;

  48489.       }

  48490.     }

  48491.     sqlite3GlobalConfig.pcache2.xTruncate(pCache->pCache, pgno+1);

  48492.   }

  48493. }

  48494. 

  48495. /*

  48496. ** Close a cache.

  48497. */

  48498. SQLITE_PRIVATE void sqlite3PcacheClose(PCache *pCache){

  48499.   assert( pCache->pCache!=0 );

  48500.   pcacheTrace(("%p.CLOSE\n",pCache));

  48501.   sqlite3GlobalConfig.pcache2.xDestroy(pCache->pCache);

  48502. }

  48503. 

  48504. /* 

  48505. ** Discard the contents of the cache.

  48506. */

  48507. SQLITE_PRIVATE void sqlite3PcacheClear(PCache *pCache){

  48508.   sqlite3PcacheTruncate(pCache, 0);

  48509. }

  48510. 

  48511. /*

  48512. ** Merge two lists of pages connected by pDirty and in pgno order.

  48513. ** Do not bother fixing the pDirtyPrev pointers.

  48514. */

  48515. static PgHdr *pcacheMergeDirtyList(PgHdr *pA, PgHdr *pB){

  48516.   PgHdr result, *pTail;

  48517.   pTail = &result;

  48518.   assert( pA!=0 && pB!=0 );

  48519.   for(;;){

  48520.     if( pA->pgno<pB->pgno ){

  48521.       pTail->pDirty = pA;

  48522.       pTail = pA;

  48523.       pA = pA->pDirty;

  48524.       if( pA==0 ){

  48525.         pTail->pDirty = pB;

  48526.         break;

  48527.       }

  48528.     }else{

  48529.       pTail->pDirty = pB;

  48530.       pTail = pB;

  48531.       pB = pB->pDirty;

  48532.       if( pB==0 ){

  48533.         pTail->pDirty = pA;

  48534.         break;

  48535.       }

  48536.     }

  48537.   }

  48538.   return result.pDirty;

  48539. }

  48540. 

  48541. /*

  48542. ** Sort the list of pages in accending order by pgno.  Pages are

  48543. ** connected by pDirty pointers.  The pDirtyPrev pointers are

  48544. ** corrupted by this sort.

  48545. **

  48546. ** Since there cannot be more than 2^31 distinct pages in a database,

  48547. ** there cannot be more than 31 buckets required by the merge sorter.

  48548. ** One extra bucket is added to catch overflow in case something

  48549. ** ever changes to make the previous sentence incorrect.

  48550. */

  48551. #define N_SORT_BUCKET  32

  48552. static PgHdr *pcacheSortDirtyList(PgHdr *pIn){

  48553.   PgHdr *a[N_SORT_BUCKET], *p;

  48554.   int i;

  48555.   memset(a, 0, sizeof(a));

  48556.   while( pIn ){

  48557.     p = pIn;

  48558.     pIn = p->pDirty;

  48559.     p->pDirty = 0;

  48560.     for(i=0; ALWAYS(i<N_SORT_BUCKET-1); i++){

  48561.       if( a[i]==0 ){

  48562.         a[i] = p;

  48563.         break;

  48564.       }else{

  48565.         p = pcacheMergeDirtyList(a[i], p);

  48566.         a[i] = 0;

  48567.       }

  48568.     }

  48569.     if( NEVER(i==N_SORT_BUCKET-1) ){

  48570.       /* To get here, there need to be 2^(N_SORT_BUCKET) elements in

  48571.       ** the input list.  But that is impossible.

  48572.       */

  48573.       a[i] = pcacheMergeDirtyList(a[i], p);

  48574.     }

  48575.   }

  48576.   p = a[0];

  48577.   for(i=1; i<N_SORT_BUCKET; i++){

  48578.     if( a[i]==0 ) continue;

  48579.     p = p ? pcacheMergeDirtyList(p, a[i]) : a[i];

  48580.   }

  48581.   return p;

  48582. }

  48583. 

  48584. /*

  48585. ** Return a list of all dirty pages in the cache, sorted by page number.

  48586. */

  48587. SQLITE_PRIVATE PgHdr *sqlite3PcacheDirtyList(PCache *pCache){

  48588.   PgHdr *p;

  48589.   for(p=pCache->pDirty; p; p=p->pDirtyNext){

  48590.     p->pDirty = p->pDirtyNext;

  48591.   }

  48592.   return pcacheSortDirtyList(pCache->pDirty);

  48593. }

  48594. 

  48595. /* 

  48596. ** Return the total number of references to all pages held by the cache.

  48597. **

  48598. ** This is not the total number of pages referenced, but the sum of the

  48599. ** reference count for all pages.

  48600. */

  48601. SQLITE_PRIVATE int sqlite3PcacheRefCount(PCache *pCache){

  48602.   return pCache->nRefSum;

  48603. }

  48604. 

  48605. /*

  48606. ** Return the number of references to the page supplied as an argument.

  48607. */

  48608. SQLITE_PRIVATE int sqlite3PcachePageRefcount(PgHdr *p){

  48609.   return p->nRef;

  48610. }

  48611. 

  48612. /* 

  48613. ** Return the total number of pages in the cache.

  48614. */

  48615. SQLITE_PRIVATE int sqlite3PcachePagecount(PCache *pCache){

  48616.   assert( pCache->pCache!=0 );

  48617.   return sqlite3GlobalConfig.pcache2.xPagecount(pCache->pCache);

  48618. }

  48619. 

  48620. #ifdef SQLITE_TEST

  48621. /*

  48622. ** Get the suggested cache-size value.

  48623. */

  48624. SQLITE_PRIVATE int sqlite3PcacheGetCachesize(PCache *pCache){

  48625.   return numberOfCachePages(pCache);

  48626. }

  48627. #endif

  48628. 

  48629. /*

  48630. ** Set the suggested cache-size value.

  48631. */

  48632. SQLITE_PRIVATE void sqlite3PcacheSetCachesize(PCache *pCache, int mxPage){

  48633.   assert( pCache->pCache!=0 );

  48634.   pCache->szCache = mxPage;

  48635.   sqlite3GlobalConfig.pcache2.xCachesize(pCache->pCache,

  48636.                                          numberOfCachePages(pCache));

  48637. }

  48638. 

  48639. /*

  48640. ** Set the suggested cache-spill value.  Make no changes if if the

  48641. ** argument is zero.  Return the effective cache-spill size, which will

  48642. ** be the larger of the szSpill and szCache.

  48643. */

  48644. SQLITE_PRIVATE int sqlite3PcacheSetSpillsize(PCache *p, int mxPage){

  48645.   int res;

  48646.   assert( p->pCache!=0 );

  48647.   if( mxPage ){

  48648.     if( mxPage<0 ){

  48649.       mxPage = (int)((-1024*(i64)mxPage)/(p->szPage+p->szExtra));

  48650.     }

  48651.     p->szSpill = mxPage;

  48652.   }

  48653.   res = numberOfCachePages(p);

  48654.   if( res<p->szSpill ) res = p->szSpill; 

  48655.   return res;

  48656. }

  48657. 

  48658. /*

  48659. ** Free up as much memory as possible from the page cache.

  48660. */

  48661. SQLITE_PRIVATE void sqlite3PcacheShrink(PCache *pCache){

  48662.   assert( pCache->pCache!=0 );

  48663.   sqlite3GlobalConfig.pcache2.xShrink(pCache->pCache);

  48664. }

  48665. 

  48666. /*

  48667. ** Return the size of the header added by this middleware layer

  48668. ** in the page-cache hierarchy.

  48669. */

  48670. SQLITE_PRIVATE int sqlite3HeaderSizePcache(void){ return ROUND8(sizeof(PgHdr)); }

  48671. 

  48672. /*

  48673. ** Return the number of dirty pages currently in the cache, as a percentage

  48674. ** of the configured cache size.

  48675. */

  48676. SQLITE_PRIVATE int sqlite3PCachePercentDirty(PCache *pCache){

  48677.   PgHdr *pDirty;

  48678.   int nDirty = 0;

  48679.   int nCache = numberOfCachePages(pCache);

  48680.   for(pDirty=pCache->pDirty; pDirty; pDirty=pDirty->pDirtyNext) nDirty++;

  48681.   return nCache ? (int)(((i64)nDirty * 100) / nCache) : 0;

  48682. }

  48683. 

  48684. #ifdef SQLITE_DIRECT_OVERFLOW_READ

  48685. /* 

  48686. ** Return true if there are one or more dirty pages in the cache. Else false.

  48687. */

  48688. SQLITE_PRIVATE int sqlite3PCacheIsDirty(PCache *pCache){

  48689.   return (pCache->pDirty!=0);

  48690. }

  48691. #endif

  48692. 

  48693. #if defined(SQLITE_CHECK_PAGES) || defined(SQLITE_DEBUG)

  48694. /*

  48695. ** For all dirty pages currently in the cache, invoke the specified

  48696. ** callback. This is only used if the SQLITE_CHECK_PAGES macro is

  48697. ** defined.

  48698. */

  48699. SQLITE_PRIVATE void sqlite3PcacheIterateDirty(PCache *pCache, void (*xIter)(PgHdr *)){

  48700.   PgHdr *pDirty;

  48701.   for(pDirty=pCache->pDirty; pDirty; pDirty=pDirty->pDirtyNext){

  48702.     xIter(pDirty);

  48703.   }

  48704. }

  48705. #endif

  48706. 

  48707. /************** End of pcache.c **********************************************/

  48708. /************** Begin file pcache1.c *****************************************/

  48709. /*

  48710. ** 2008 November 05

  48711. **

  48712. ** The author disclaims copyright to this source code.  In place of

  48713. ** a legal notice, here is a blessing:

  48714. **

  48715. **    May you do good and not evil.

  48716. **    May you find forgiveness for yourself and forgive others.

  48717. **    May you share freely, never taking more than you give.

  48718. **

  48719. *************************************************************************

  48720. **

  48721. ** This file implements the default page cache implementation (the

  48722. ** sqlite3_pcache interface). It also contains part of the implementation

  48723. ** of the SQLITE_CONFIG_PAGECACHE and sqlite3_release_memory() features.

  48724. ** If the default page cache implementation is overridden, then neither of

  48725. ** these two features are available.

  48726. **

  48727. ** A Page cache line looks like this:

  48728. **

  48729. **  -------------------------------------------------------------

  48730. **  |  database page content   |  PgHdr1  |  MemPage  |  PgHdr  |

  48731. **  -------------------------------------------------------------

  48732. **

  48733. ** The database page content is up front (so that buffer overreads tend to

  48734. ** flow harmlessly into the PgHdr1, MemPage, and PgHdr extensions).   MemPage

  48735. ** is the extension added by the btree.c module containing information such

  48736. ** as the database page number and how that database page is used.  PgHdr

  48737. ** is added by the pcache.c layer and contains information used to keep track

  48738. ** of which pages are "dirty".  PgHdr1 is an extension added by this

  48739. ** module (pcache1.c).  The PgHdr1 header is a subclass of sqlite3_pcache_page.

  48740. ** PgHdr1 contains information needed to look up a page by its page number.

  48741. ** The superclass sqlite3_pcache_page.pBuf points to the start of the

  48742. ** database page content and sqlite3_pcache_page.pExtra points to PgHdr.

  48743. **

  48744. ** The size of the extension (MemPage+PgHdr+PgHdr1) can be determined at

  48745. ** runtime using sqlite3_config(SQLITE_CONFIG_PCACHE_HDRSZ, &size).  The

  48746. ** sizes of the extensions sum to 272 bytes on x64 for 3.8.10, but this

  48747. ** size can vary according to architecture, compile-time options, and

  48748. ** SQLite library version number.

  48749. **

  48750. ** If SQLITE_PCACHE_SEPARATE_HEADER is defined, then the extension is obtained

  48751. ** using a separate memory allocation from the database page content.  This

  48752. ** seeks to overcome the "clownshoe" problem (also called "internal

  48753. ** fragmentation" in academic literature) of allocating a few bytes more

  48754. ** than a power of two with the memory allocator rounding up to the next

  48755. ** power of two, and leaving the rounded-up space unused.

  48756. **

  48757. ** This module tracks pointers to PgHdr1 objects.  Only pcache.c communicates

  48758. ** with this module.  Information is passed back and forth as PgHdr1 pointers.

  48759. **

  48760. ** The pcache.c and pager.c modules deal pointers to PgHdr objects.

  48761. ** The btree.c module deals with pointers to MemPage objects.

  48762. **

  48763. ** SOURCE OF PAGE CACHE MEMORY:

  48764. **

  48765. ** Memory for a page might come from any of three sources:

  48766. **

  48767. **    (1)  The general-purpose memory allocator - sqlite3Malloc()

  48768. **    (2)  Global page-cache memory provided using sqlite3_config() with

  48769. **         SQLITE_CONFIG_PAGECACHE.

  48770. **    (3)  PCache-local bulk allocation.

  48771. **

  48772. ** The third case is a chunk of heap memory (defaulting to 100 pages worth)

  48773. ** that is allocated when the page cache is created.  The size of the local

  48774. ** bulk allocation can be adjusted using 

  48775. **

  48776. **     sqlite3_config(SQLITE_CONFIG_PAGECACHE, (void*)0, 0, N).

  48777. **

  48778. ** If N is positive, then N pages worth of memory are allocated using a single

  48779. ** sqlite3Malloc() call and that memory is used for the first N pages allocated.

  48780. ** Or if N is negative, then -1024*N bytes of memory are allocated and used

  48781. ** for as many pages as can be accomodated.

  48782. **

  48783. ** Only one of (2) or (3) can be used.  Once the memory available to (2) or

  48784. ** (3) is exhausted, subsequent allocations fail over to the general-purpose

  48785. ** memory allocator (1).

  48786. **

  48787. ** Earlier versions of SQLite used only methods (1) and (2).  But experiments

  48788. ** show that method (3) with N==100 provides about a 5% performance boost for

  48789. ** common workloads.

  48790. */

  48791. /* #include "sqliteInt.h" */

  48792. 

  48793. typedef struct PCache1 PCache1;

  48794. typedef struct PgHdr1 PgHdr1;

  48795. typedef struct PgFreeslot PgFreeslot;

  48796. typedef struct PGroup PGroup;

  48797. 

  48798. /*

  48799. ** Each cache entry is represented by an instance of the following 

  48800. ** structure. Unless SQLITE_PCACHE_SEPARATE_HEADER is defined, a buffer of

  48801. ** PgHdr1.pCache->szPage bytes is allocated directly before this structure 

  48802. ** in memory.

  48803. **

  48804. ** Note: Variables isBulkLocal and isAnchor were once type "u8". That works,

  48805. ** but causes a 2-byte gap in the structure for most architectures (since 

  48806. ** pointers must be either 4 or 8-byte aligned). As this structure is located

  48807. ** in memory directly after the associated page data, if the database is

  48808. ** corrupt, code at the b-tree layer may overread the page buffer and 

  48809. ** read part of this structure before the corruption is detected. This

  48810. ** can cause a valgrind error if the unitialized gap is accessed. Using u16

  48811. ** ensures there is no such gap, and therefore no bytes of unitialized memory

  48812. ** in the structure.

  48813. */

  48814. struct PgHdr1 {

  48815.   sqlite3_pcache_page page;      /* Base class. Must be first. pBuf & pExtra */

  48816.   unsigned int iKey;             /* Key value (page number) */

  48817.   u16 isBulkLocal;               /* This page from bulk local storage */

  48818.   u16 isAnchor;                  /* This is the PGroup.lru element */

  48819.   PgHdr1 *pNext;                 /* Next in hash table chain */

  48820.   PCache1 *pCache;               /* Cache that currently owns this page */

  48821.   PgHdr1 *pLruNext;              /* Next in LRU list of unpinned pages */

  48822.   PgHdr1 *pLruPrev;              /* Previous in LRU list of unpinned pages */

  48823.                                  /* NB: pLruPrev is only valid if pLruNext!=0 */

  48824. };

  48825. 

  48826. /*

  48827. ** A page is pinned if it is not on the LRU list.  To be "pinned" means

  48828. ** that the page is in active use and must not be deallocated.

  48829. */

  48830. #define PAGE_IS_PINNED(p)    ((p)->pLruNext==0)

  48831. #define PAGE_IS_UNPINNED(p)  ((p)->pLruNext!=0)

  48832. 

  48833. /* Each page cache (or PCache) belongs to a PGroup.  A PGroup is a set 

  48834. ** of one or more PCaches that are able to recycle each other's unpinned

  48835. ** pages when they are under memory pressure.  A PGroup is an instance of

  48836. ** the following object.

  48837. **

  48838. ** This page cache implementation works in one of two modes:

  48839. **

  48840. **   (1)  Every PCache is the sole member of its own PGroup.  There is

  48841. **        one PGroup per PCache.

  48842. **

  48843. **   (2)  There is a single global PGroup that all PCaches are a member

  48844. **        of.

  48845. **

  48846. ** Mode 1 uses more memory (since PCache instances are not able to rob

  48847. ** unused pages from other PCaches) but it also operates without a mutex,

  48848. ** and is therefore often faster.  Mode 2 requires a mutex in order to be

  48849. ** threadsafe, but recycles pages more efficiently.

  48850. **

  48851. ** For mode (1), PGroup.mutex is NULL.  For mode (2) there is only a single

  48852. ** PGroup which is the pcache1.grp global variable and its mutex is

  48853. ** SQLITE_MUTEX_STATIC_LRU.

  48854. */

  48855. struct PGroup {

  48856.   sqlite3_mutex *mutex;          /* MUTEX_STATIC_LRU or NULL */

  48857.   unsigned int nMaxPage;         /* Sum of nMax for purgeable caches */

  48858.   unsigned int nMinPage;         /* Sum of nMin for purgeable caches */

  48859.   unsigned int mxPinned;         /* nMaxpage + 10 - nMinPage */

  48860.   unsigned int nPurgeable;       /* Number of purgeable pages allocated */

  48861.   PgHdr1 lru;                    /* The beginning and end of the LRU list */

  48862. };

  48863. 

  48864. /* Each page cache is an instance of the following object.  Every

  48865. ** open database file (including each in-memory database and each

  48866. ** temporary or transient database) has a single page cache which

  48867. ** is an instance of this object.

  48868. **

  48869. ** Pointers to structures of this type are cast and returned as 

  48870. ** opaque sqlite3_pcache* handles.

  48871. */

  48872. struct PCache1 {

  48873.   /* Cache configuration parameters. Page size (szPage) and the purgeable

  48874.   ** flag (bPurgeable) and the pnPurgeable pointer are all set when the

  48875.   ** cache is created and are never changed thereafter. nMax may be 

  48876.   ** modified at any time by a call to the pcache1Cachesize() method.

  48877.   ** The PGroup mutex must be held when accessing nMax.

  48878.   */

  48879.   PGroup *pGroup;                     /* PGroup this cache belongs to */

  48880.   unsigned int *pnPurgeable;          /* Pointer to pGroup->nPurgeable */

  48881.   int szPage;                         /* Size of database content section */

  48882.   int szExtra;                        /* sizeof(MemPage)+sizeof(PgHdr) */

  48883.   int szAlloc;                        /* Total size of one pcache line */

  48884.   int bPurgeable;                     /* True if cache is purgeable */

  48885.   unsigned int nMin;                  /* Minimum number of pages reserved */

  48886.   unsigned int nMax;                  /* Configured "cache_size" value */

  48887.   unsigned int n90pct;                /* nMax*9/10 */

  48888.   unsigned int iMaxKey;               /* Largest key seen since xTruncate() */

  48889.   unsigned int nPurgeableDummy;       /* pnPurgeable points here when not used*/

  48890. 

  48891.   /* Hash table of all pages. The following variables may only be accessed

  48892.   ** when the accessor is holding the PGroup mutex.

  48893.   */

  48894.   unsigned int nRecyclable;           /* Number of pages in the LRU list */

  48895.   unsigned int nPage;                 /* Total number of pages in apHash */

  48896.   unsigned int nHash;                 /* Number of slots in apHash[] */

  48897.   PgHdr1 **apHash;                    /* Hash table for fast lookup by key */

  48898.   PgHdr1 *pFree;                      /* List of unused pcache-local pages */

  48899.   void *pBulk;                        /* Bulk memory used by pcache-local */

  48900. };

  48901. 

  48902. /*

  48903. ** Free slots in the allocator used to divide up the global page cache

  48904. ** buffer provided using the SQLITE_CONFIG_PAGECACHE mechanism.

  48905. */

  48906. struct PgFreeslot {

  48907.   PgFreeslot *pNext;  /* Next free slot */

  48908. };

  48909. 

  48910. /*

  48911. ** Global data used by this cache.

  48912. */

  48913. static SQLITE_WSD struct PCacheGlobal {

  48914.   PGroup grp;                    /* The global PGroup for mode (2) */

  48915. 

  48916.   /* Variables related to SQLITE_CONFIG_PAGECACHE settings.  The

  48917.   ** szSlot, nSlot, pStart, pEnd, nReserve, and isInit values are all

  48918.   ** fixed at sqlite3_initialize() time and do not require mutex protection.

  48919.   ** The nFreeSlot and pFree values do require mutex protection.

  48920.   */

  48921.   int isInit;                    /* True if initialized */

  48922.   int separateCache;             /* Use a new PGroup for each PCache */

  48923.   int nInitPage;                 /* Initial bulk allocation size */   

  48924.   int szSlot;                    /* Size of each free slot */

  48925.   int nSlot;                     /* The number of pcache slots */

  48926.   int nReserve;                  /* Try to keep nFreeSlot above this */

  48927.   void *pStart, *pEnd;           /* Bounds of global page cache memory */

  48928.   /* Above requires no mutex.  Use mutex below for variable that follow. */

  48929.   sqlite3_mutex *mutex;          /* Mutex for accessing the following: */

  48930.   PgFreeslot *pFree;             /* Free page blocks */

  48931.   int nFreeSlot;                 /* Number of unused pcache slots */

  48932.   /* The following value requires a mutex to change.  We skip the mutex on

  48933.   ** reading because (1) most platforms read a 32-bit integer atomically and

  48934.   ** (2) even if an incorrect value is read, no great harm is done since this

  48935.   ** is really just an optimization. */

  48936.   int bUnderPressure;            /* True if low on PAGECACHE memory */

  48937. } pcache1_g;

  48938. 

  48939. /*

  48940. ** All code in this file should access the global structure above via the

  48941. ** alias "pcache1". This ensures that the WSD emulation is used when

  48942. ** compiling for systems that do not support real WSD.

  48943. */

  48944. #define pcache1 (GLOBAL(struct PCacheGlobal, pcache1_g))

  48945. 

  48946. /*

  48947. ** Macros to enter and leave the PCache LRU mutex.

  48948. */

  48949. #if !defined(SQLITE_ENABLE_MEMORY_MANAGEMENT) || SQLITE_THREADSAFE==0

  48950. # define pcache1EnterMutex(X)  assert((X)->mutex==0)

  48951. # define pcache1LeaveMutex(X)  assert((X)->mutex==0)

  48952. # define PCACHE1_MIGHT_USE_GROUP_MUTEX 0

  48953. #else

  48954. # define pcache1EnterMutex(X) sqlite3_mutex_enter((X)->mutex)

  48955. # define pcache1LeaveMutex(X) sqlite3_mutex_leave((X)->mutex)

  48956. # define PCACHE1_MIGHT_USE_GROUP_MUTEX 1

  48957. #endif

  48958. 

  48959. /******************************************************************************/

  48960. /******** Page Allocation/SQLITE_CONFIG_PCACHE Related Functions **************/

  48961. 

  48962. 

  48963. /*

  48964. ** This function is called during initialization if a static buffer is 

  48965. ** supplied to use for the page-cache by passing the SQLITE_CONFIG_PAGECACHE

  48966. ** verb to sqlite3_config(). Parameter pBuf points to an allocation large

  48967. ** enough to contain 'n' buffers of 'sz' bytes each.

  48968. **

  48969. ** This routine is called from sqlite3_initialize() and so it is guaranteed

  48970. ** to be serialized already.  There is no need for further mutexing.

  48971. */

  48972. SQLITE_PRIVATE void sqlite3PCacheBufferSetup(void *pBuf, int sz, int n){

  48973.   if( pcache1.isInit ){

  48974.     PgFreeslot *p;

  48975.     if( pBuf==0 ) sz = n = 0;

  48976.     if( n==0 ) sz = 0;

  48977.     sz = ROUNDDOWN8(sz);

  48978.     pcache1.szSlot = sz;

  48979.     pcache1.nSlot = pcache1.nFreeSlot = n;

  48980.     pcache1.nReserve = n>90 ? 10 : (n/10 + 1);

  48981.     pcache1.pStart = pBuf;

  48982.     pcache1.pFree = 0;

  48983.     pcache1.bUnderPressure = 0;

  48984.     while( n-- ){

  48985.       p = (PgFreeslot*)pBuf;

  48986.       p->pNext = pcache1.pFree;

  48987.       pcache1.pFree = p;

  48988.       pBuf = (void*)&((char*)pBuf)[sz];

  48989.     }

  48990.     pcache1.pEnd = pBuf;

  48991.   }

  48992. }

  48993. 

  48994. /*

  48995. ** Try to initialize the pCache->pFree and pCache->pBulk fields.  Return

  48996. ** true if pCache->pFree ends up containing one or more free pages.

  48997. */

  48998. static int pcache1InitBulk(PCache1 *pCache){

  48999.   i64 szBulk;

  49000.   char *zBulk;

  49001.   if( pcache1.nInitPage==0 ) return 0;

  49002.   /* Do not bother with a bulk allocation if the cache size very small */

  49003.   if( pCache->nMax<3 ) return 0;

  49004.   sqlite3BeginBenignMalloc();

  49005.   if( pcache1.nInitPage>0 ){

  49006.     szBulk = pCache->szAlloc * (i64)pcache1.nInitPage;

  49007.   }else{

  49008.     szBulk = -1024 * (i64)pcache1.nInitPage;

  49009.   }

  49010.   if( szBulk > pCache->szAlloc*(i64)pCache->nMax ){

  49011.     szBulk = pCache->szAlloc*(i64)pCache->nMax;

  49012.   }

  49013.   zBulk = pCache->pBulk = sqlite3Malloc( szBulk );

  49014.   sqlite3EndBenignMalloc();

  49015.   if( zBulk ){

  49016.     int nBulk = sqlite3MallocSize(zBulk)/pCache->szAlloc;

  49017.     do{

  49018.       PgHdr1 *pX = (PgHdr1*)&zBulk[pCache->szPage];

  49019.       pX->page.pBuf = zBulk;

  49020.       pX->page.pExtra = &pX[1];

  49021.       pX->isBulkLocal = 1;

  49022.       pX->isAnchor = 0;

  49023.       pX->pNext = pCache->pFree;

  49024.       pX->pLruPrev = 0;           /* Initializing this saves a valgrind error */

  49025.       pCache->pFree = pX;

  49026.       zBulk += pCache->szAlloc;

  49027.     }while( --nBulk );

  49028.   }

  49029.   return pCache->pFree!=0;

  49030. }

  49031. 

  49032. /*

  49033. ** Malloc function used within this file to allocate space from the buffer

  49034. ** configured using sqlite3_config(SQLITE_CONFIG_PAGECACHE) option. If no 

  49035. ** such buffer exists or there is no space left in it, this function falls 

  49036. ** back to sqlite3Malloc().

  49037. **

  49038. ** Multiple threads can run this routine at the same time.  Global variables

  49039. ** in pcache1 need to be protected via mutex.

  49040. */

  49041. static void *pcache1Alloc(int nByte){

  49042.   void *p = 0;

  49043.   assert( sqlite3_mutex_notheld(pcache1.grp.mutex) );

  49044.   if( nByte<=pcache1.szSlot ){

  49045.     sqlite3_mutex_enter(pcache1.mutex);

  49046.     p = (PgHdr1 *)pcache1.pFree;

  49047.     if( p ){

  49048.       pcache1.pFree = pcache1.pFree->pNext;

  49049.       pcache1.nFreeSlot--;

  49050.       pcache1.bUnderPressure = pcache1.nFreeSlot<pcache1.nReserve;

  49051.       assert( pcache1.nFreeSlot>=0 );

  49052.       sqlite3StatusHighwater(SQLITE_STATUS_PAGECACHE_SIZE, nByte);

  49053.       sqlite3StatusUp(SQLITE_STATUS_PAGECACHE_USED, 1);

  49054.     }

  49055.     sqlite3_mutex_leave(pcache1.mutex);

  49056.   }

  49057.   if( p==0 ){

  49058.     /* Memory is not available in the SQLITE_CONFIG_PAGECACHE pool.  Get

  49059.     ** it from sqlite3Malloc instead.

  49060.     */

  49061.     p = sqlite3Malloc(nByte);

  49062. #ifndef SQLITE_DISABLE_PAGECACHE_OVERFLOW_STATS

  49063.     if( p ){

  49064.       int sz = sqlite3MallocSize(p);

  49065.       sqlite3_mutex_enter(pcache1.mutex);

  49066.       sqlite3StatusHighwater(SQLITE_STATUS_PAGECACHE_SIZE, nByte);

  49067.       sqlite3StatusUp(SQLITE_STATUS_PAGECACHE_OVERFLOW, sz);

  49068.       sqlite3_mutex_leave(pcache1.mutex);

  49069.     }

  49070. #endif

  49071.     sqlite3MemdebugSetType(p, MEMTYPE_PCACHE);

  49072.   }

  49073.   return p;

  49074. }

  49075. 

  49076. /*

  49077. ** Free an allocated buffer obtained from pcache1Alloc().

  49078. */

  49079. static void pcache1Free(void *p){

  49080.   if( p==0 ) return;

  49081.   if( SQLITE_WITHIN(p, pcache1.pStart, pcache1.pEnd) ){

  49082.     PgFreeslot *pSlot;

  49083.     sqlite3_mutex_enter(pcache1.mutex);

  49084.     sqlite3StatusDown(SQLITE_STATUS_PAGECACHE_USED, 1);

  49085.     pSlot = (PgFreeslot*)p;

  49086.     pSlot->pNext = pcache1.pFree;

  49087.     pcache1.pFree = pSlot;

  49088.     pcache1.nFreeSlot++;

  49089.     pcache1.bUnderPressure = pcache1.nFreeSlot<pcache1.nReserve;

  49090.     assert( pcache1.nFreeSlot<=pcache1.nSlot );

  49091.     sqlite3_mutex_leave(pcache1.mutex);

  49092.   }else{

  49093.     assert( sqlite3MemdebugHasType(p, MEMTYPE_PCACHE) );

  49094.     sqlite3MemdebugSetType(p, MEMTYPE_HEAP);

  49095. #ifndef SQLITE_DISABLE_PAGECACHE_OVERFLOW_STATS

  49096.     {

  49097.       int nFreed = 0;

  49098.       nFreed = sqlite3MallocSize(p);

  49099.       sqlite3_mutex_enter(pcache1.mutex);

  49100.       sqlite3StatusDown(SQLITE_STATUS_PAGECACHE_OVERFLOW, nFreed);

  49101.       sqlite3_mutex_leave(pcache1.mutex);

  49102.     }

  49103. #endif

  49104.     sqlite3_free(p);

  49105.   }

  49106. }

  49107. 

  49108. #ifdef SQLITE_ENABLE_MEMORY_MANAGEMENT

  49109. /*

  49110. ** Return the size of a pcache allocation

  49111. */

  49112. static int pcache1MemSize(void *p){

  49113.   if( p>=pcache1.pStart && p<pcache1.pEnd ){

  49114.     return pcache1.szSlot;

  49115.   }else{

  49116.     int iSize;

  49117.     assert( sqlite3MemdebugHasType(p, MEMTYPE_PCACHE) );

  49118.     sqlite3MemdebugSetType(p, MEMTYPE_HEAP);

  49119.     iSize = sqlite3MallocSize(p);

  49120.     sqlite3MemdebugSetType(p, MEMTYPE_PCACHE);

  49121.     return iSize;

  49122.   }

  49123. }

  49124. #endif /* SQLITE_ENABLE_MEMORY_MANAGEMENT */

  49125. 

  49126. /*

  49127. ** Allocate a new page object initially associated with cache pCache.

  49128. */

  49129. static PgHdr1 *pcache1AllocPage(PCache1 *pCache, int benignMalloc){

  49130.   PgHdr1 *p = 0;

  49131.   void *pPg;

  49132. 

  49133.   assert( sqlite3_mutex_held(pCache->pGroup->mutex) );

  49134.   if( pCache->pFree || (pCache->nPage==0 && pcache1InitBulk(pCache)) ){

  49135.     p = pCache->pFree;

  49136.     pCache->pFree = p->pNext;

  49137.     p->pNext = 0;

  49138.   }else{

  49139. #ifdef SQLITE_ENABLE_MEMORY_MANAGEMENT

  49140.     /* The group mutex must be released before pcache1Alloc() is called. This

  49141.     ** is because it might call sqlite3_release_memory(), which assumes that 

  49142.     ** this mutex is not held. */

  49143.     assert( pcache1.separateCache==0 );

  49144.     assert( pCache->pGroup==&pcache1.grp );

  49145.     pcache1LeaveMutex(pCache->pGroup);

  49146. #endif

  49147.     if( benignMalloc ){ sqlite3BeginBenignMalloc(); }

  49148. #ifdef SQLITE_PCACHE_SEPARATE_HEADER

  49149.     pPg = pcache1Alloc(pCache->szPage);

  49150.     p = sqlite3Malloc(sizeof(PgHdr1) + pCache->szExtra);

  49151.     if( !pPg || !p ){

  49152.       pcache1Free(pPg);

  49153.       sqlite3_free(p);

  49154.       pPg = 0;

  49155.     }

  49156. #else

  49157.     pPg = pcache1Alloc(pCache->szAlloc);

  49158.     p = (PgHdr1 *)&((u8 *)pPg)[pCache->szPage];

  49159. #endif

  49160.     if( benignMalloc ){ sqlite3EndBenignMalloc(); }

  49161. #ifdef SQLITE_ENABLE_MEMORY_MANAGEMENT

  49162.     pcache1EnterMutex(pCache->pGroup);

  49163. #endif

  49164.     if( pPg==0 ) return 0;

  49165.     p->page.pBuf = pPg;

  49166.     p->page.pExtra = &p[1];

  49167.     p->isBulkLocal = 0;

  49168.     p->isAnchor = 0;

  49169.   }

  49170.   (*pCache->pnPurgeable)++;

  49171.   return p;

  49172. }

  49173. 

  49174. /*

  49175. ** Free a page object allocated by pcache1AllocPage().

  49176. */

  49177. static void pcache1FreePage(PgHdr1 *p){

  49178.   PCache1 *pCache;

  49179.   assert( p!=0 );

  49180.   pCache = p->pCache;

  49181.   assert( sqlite3_mutex_held(p->pCache->pGroup->mutex) );

  49182.   if( p->isBulkLocal ){

  49183.     p->pNext = pCache->pFree;

  49184.     pCache->pFree = p;

  49185.   }else{

  49186.     pcache1Free(p->page.pBuf);

  49187. #ifdef SQLITE_PCACHE_SEPARATE_HEADER

  49188.     sqlite3_free(p);

  49189. #endif

  49190.   }

  49191.   (*pCache->pnPurgeable)--;

  49192. }

  49193. 

  49194. /*

  49195. ** Malloc function used by SQLite to obtain space from the buffer configured

  49196. ** using sqlite3_config(SQLITE_CONFIG_PAGECACHE) option. If no such buffer

  49197. ** exists, this function falls back to sqlite3Malloc().

  49198. */

  49199. SQLITE_PRIVATE void *sqlite3PageMalloc(int sz){

  49200.   assert( sz<=65536+8 ); /* These allocations are never very large */

  49201.   return pcache1Alloc(sz);

  49202. }

  49203. 

  49204. /*

  49205. ** Free an allocated buffer obtained from sqlite3PageMalloc().

  49206. */

  49207. SQLITE_PRIVATE void sqlite3PageFree(void *p){

  49208.   pcache1Free(p);

  49209. }

  49210. 

  49211. 

  49212. /*

  49213. ** Return true if it desirable to avoid allocating a new page cache

  49214. ** entry.

  49215. **

  49216. ** If memory was allocated specifically to the page cache using

  49217. ** SQLITE_CONFIG_PAGECACHE but that memory has all been used, then

  49218. ** it is desirable to avoid allocating a new page cache entry because

  49219. ** presumably SQLITE_CONFIG_PAGECACHE was suppose to be sufficient

  49220. ** for all page cache needs and we should not need to spill the

  49221. ** allocation onto the heap.

  49222. **

  49223. ** Or, the heap is used for all page cache memory but the heap is

  49224. ** under memory pressure, then again it is desirable to avoid

  49225. ** allocating a new page cache entry in order to avoid stressing

  49226. ** the heap even further.

  49227. */

  49228. static int pcache1UnderMemoryPressure(PCache1 *pCache){

  49229.   if( pcache1.nSlot && (pCache->szPage+pCache->szExtra)<=pcache1.szSlot ){

  49230.     return pcache1.bUnderPressure;

  49231.   }else{

  49232.     return sqlite3HeapNearlyFull();

  49233.   }

  49234. }

  49235. 

  49236. /******************************************************************************/

  49237. /******** General Implementation Functions ************************************/

  49238. 

  49239. /*

  49240. ** This function is used to resize the hash table used by the cache passed

  49241. ** as the first argument.

  49242. **

  49243. ** The PCache mutex must be held when this function is called.

  49244. */

  49245. static void pcache1ResizeHash(PCache1 *p){

  49246.   PgHdr1 **apNew;

  49247.   unsigned int nNew;

  49248.   unsigned int i;

  49249. 

  49250.   assert( sqlite3_mutex_held(p->pGroup->mutex) );

  49251. 

  49252.   nNew = p->nHash*2;

  49253.   if( nNew<256 ){

  49254.     nNew = 256;

  49255.   }

  49256. 

  49257.   pcache1LeaveMutex(p->pGroup);

  49258.   if( p->nHash ){ sqlite3BeginBenignMalloc(); }

  49259.   apNew = (PgHdr1 **)sqlite3MallocZero(sizeof(PgHdr1 *)*nNew);

  49260.   if( p->nHash ){ sqlite3EndBenignMalloc(); }

  49261.   pcache1EnterMutex(p->pGroup);

  49262.   if( apNew ){

  49263.     for(i=0; i<p->nHash; i++){

  49264.       PgHdr1 *pPage;

  49265.       PgHdr1 *pNext = p->apHash[i];

  49266.       while( (pPage = pNext)!=0 ){

  49267.         unsigned int h = pPage->iKey % nNew;

  49268.         pNext = pPage->pNext;

  49269.         pPage->pNext = apNew[h];

  49270.         apNew[h] = pPage;

  49271.       }

  49272.     }

  49273.     sqlite3_free(p->apHash);

  49274.     p->apHash = apNew;

  49275.     p->nHash = nNew;

  49276.   }

  49277. }

  49278. 

  49279. /*

  49280. ** This function is used internally to remove the page pPage from the 

  49281. ** PGroup LRU list, if is part of it. If pPage is not part of the PGroup

  49282. ** LRU list, then this function is a no-op.

  49283. **

  49284. ** The PGroup mutex must be held when this function is called.

  49285. */

  49286. static PgHdr1 *pcache1PinPage(PgHdr1 *pPage){

  49287.   assert( pPage!=0 );

  49288.   assert( PAGE_IS_UNPINNED(pPage) );

  49289.   assert( pPage->pLruNext );

  49290.   assert( pPage->pLruPrev );

  49291.   assert( sqlite3_mutex_held(pPage->pCache->pGroup->mutex) );

  49292.   pPage->pLruPrev->pLruNext = pPage->pLruNext;

  49293.   pPage->pLruNext->pLruPrev = pPage->pLruPrev;

  49294.   pPage->pLruNext = 0;

  49295.   /* pPage->pLruPrev = 0;

  49296.   ** No need to clear pLruPrev as it is never accessed if pLruNext is 0 */

  49297.   assert( pPage->isAnchor==0 );

  49298.   assert( pPage->pCache->pGroup->lru.isAnchor==1 );

  49299.   pPage->pCache->nRecyclable--;

  49300.   return pPage;

  49301. }

  49302. 

  49303. 

  49304. /*

  49305. ** Remove the page supplied as an argument from the hash table 

  49306. ** (PCache1.apHash structure) that it is currently stored in.

  49307. ** Also free the page if freePage is true.

  49308. **

  49309. ** The PGroup mutex must be held when this function is called.

  49310. */

  49311. static void pcache1RemoveFromHash(PgHdr1 *pPage, int freeFlag){

  49312.   unsigned int h;

  49313.   PCache1 *pCache = pPage->pCache;

  49314.   PgHdr1 **pp;

  49315. 

  49316.   assert( sqlite3_mutex_held(pCache->pGroup->mutex) );

  49317.   h = pPage->iKey % pCache->nHash;

  49318.   for(pp=&pCache->apHash[h]; (*pp)!=pPage; pp=&(*pp)->pNext);

  49319.   *pp = (*pp)->pNext;

  49320. 

  49321.   pCache->nPage--;

  49322.   if( freeFlag ) pcache1FreePage(pPage);

  49323. }

  49324. 

  49325. /*

  49326. ** If there are currently more than nMaxPage pages allocated, try

  49327. ** to recycle pages to reduce the number allocated to nMaxPage.

  49328. */

  49329. static void pcache1EnforceMaxPage(PCache1 *pCache){

  49330.   PGroup *pGroup = pCache->pGroup;

  49331.   PgHdr1 *p;

  49332.   assert( sqlite3_mutex_held(pGroup->mutex) );

  49333.   while( pGroup->nPurgeable>pGroup->nMaxPage

  49334.       && (p=pGroup->lru.pLruPrev)->isAnchor==0

  49335.   ){

  49336.     assert( p->pCache->pGroup==pGroup );

  49337.     assert( PAGE_IS_UNPINNED(p) );

  49338.     pcache1PinPage(p);

  49339.     pcache1RemoveFromHash(p, 1);

  49340.   }

  49341.   if( pCache->nPage==0 && pCache->pBulk ){

  49342.     sqlite3_free(pCache->pBulk);

  49343.     pCache->pBulk = pCache->pFree = 0;

  49344.   }

  49345. }

  49346. 

  49347. /*

  49348. ** Discard all pages from cache pCache with a page number (key value) 

  49349. ** greater than or equal to iLimit. Any pinned pages that meet this 

  49350. ** criteria are unpinned before they are discarded.

  49351. **

  49352. ** The PCache mutex must be held when this function is called.

  49353. */

  49354. static void pcache1TruncateUnsafe(

  49355.   PCache1 *pCache,             /* The cache to truncate */

  49356.   unsigned int iLimit          /* Drop pages with this pgno or larger */

  49357. ){

  49358.   TESTONLY( int nPage = 0; )  /* To assert pCache->nPage is correct */

  49359.   unsigned int h, iStop;

  49360.   assert( sqlite3_mutex_held(pCache->pGroup->mutex) );

  49361.   assert( pCache->iMaxKey >= iLimit );

  49362.   assert( pCache->nHash > 0 );

  49363.   if( pCache->iMaxKey - iLimit < pCache->nHash ){

  49364.     /* If we are just shaving the last few pages off the end of the

  49365.     ** cache, then there is no point in scanning the entire hash table.

  49366.     ** Only scan those hash slots that might contain pages that need to

  49367.     ** be removed. */

  49368.     h = iLimit % pCache->nHash;

  49369.     iStop = pCache->iMaxKey % pCache->nHash;

  49370.     TESTONLY( nPage = -10; )  /* Disable the pCache->nPage validity check */

  49371.   }else{

  49372.     /* This is the general case where many pages are being removed.

  49373.     ** It is necessary to scan the entire hash table */

  49374.     h = pCache->nHash/2;

  49375.     iStop = h - 1;

  49376.   }

  49377.   for(;;){

  49378.     PgHdr1 **pp;

  49379.     PgHdr1 *pPage;

  49380.     assert( h<pCache->nHash );

  49381.     pp = &pCache->apHash[h]; 

  49382.     while( (pPage = *pp)!=0 ){

  49383.       if( pPage->iKey>=iLimit ){

  49384.         pCache->nPage--;

  49385.         *pp = pPage->pNext;

  49386.         if( PAGE_IS_UNPINNED(pPage) ) pcache1PinPage(pPage);

  49387.         pcache1FreePage(pPage);

  49388.       }else{

  49389.         pp = &pPage->pNext;

  49390.         TESTONLY( if( nPage>=0 ) nPage++; )

  49391.       }

  49392.     }

  49393.     if( h==iStop ) break;

  49394.     h = (h+1) % pCache->nHash;

  49395.   }

  49396.   assert( nPage<0 || pCache->nPage==(unsigned)nPage );

  49397. }

  49398. 

  49399. /******************************************************************************/

  49400. /******** sqlite3_pcache Methods **********************************************/

  49401. 

  49402. /*

  49403. ** Implementation of the sqlite3_pcache.xInit method.

  49404. */

  49405. static int pcache1Init(void *NotUsed){

  49406.   UNUSED_PARAMETER(NotUsed);

  49407.   assert( pcache1.isInit==0 );

  49408.   memset(&pcache1, 0, sizeof(pcache1));

  49409. 

  49410. 

  49411.   /*

  49412.   ** The pcache1.separateCache variable is true if each PCache has its own

  49413.   ** private PGroup (mode-1).  pcache1.separateCache is false if the single

  49414.   ** PGroup in pcache1.grp is used for all page caches (mode-2).

  49415.   **

  49416.   **   *  Always use a unified cache (mode-2) if ENABLE_MEMORY_MANAGEMENT

  49417.   **

  49418.   **   *  Use a unified cache in single-threaded applications that have

  49419.   **      configured a start-time buffer for use as page-cache memory using

  49420.   **      sqlite3_config(SQLITE_CONFIG_PAGECACHE, pBuf, sz, N) with non-NULL 

  49421.   **      pBuf argument.

  49422.   **

  49423.   **   *  Otherwise use separate caches (mode-1)

  49424.   */

  49425. #if defined(SQLITE_ENABLE_MEMORY_MANAGEMENT)

  49426.   pcache1.separateCache = 0;

  49427. #elif SQLITE_THREADSAFE

  49428.   pcache1.separateCache = sqlite3GlobalConfig.pPage==0

  49429.                           || sqlite3GlobalConfig.bCoreMutex>0;

  49430. #else

  49431.   pcache1.separateCache = sqlite3GlobalConfig.pPage==0;

  49432. #endif

  49433. 

  49434. #if SQLITE_THREADSAFE

  49435.   if( sqlite3GlobalConfig.bCoreMutex ){

  49436.     pcache1.grp.mutex = sqlite3MutexAlloc(SQLITE_MUTEX_STATIC_LRU);

  49437.     pcache1.mutex = sqlite3MutexAlloc(SQLITE_MUTEX_STATIC_PMEM);

  49438.   }

  49439. #endif

  49440.   if( pcache1.separateCache

  49441.    && sqlite3GlobalConfig.nPage!=0

  49442.    && sqlite3GlobalConfig.pPage==0

  49443.   ){

  49444.     pcache1.nInitPage = sqlite3GlobalConfig.nPage;

  49445.   }else{

  49446.     pcache1.nInitPage = 0;

  49447.   }

  49448.   pcache1.grp.mxPinned = 10;

  49449.   pcache1.isInit = 1;

  49450.   return SQLITE_OK;

  49451. }

  49452. 

  49453. /*

  49454. ** Implementation of the sqlite3_pcache.xShutdown method.

  49455. ** Note that the static mutex allocated in xInit does 

  49456. ** not need to be freed.

  49457. */

  49458. static void pcache1Shutdown(void *NotUsed){

  49459.   UNUSED_PARAMETER(NotUsed);

  49460.   assert( pcache1.isInit!=0 );

  49461.   memset(&pcache1, 0, sizeof(pcache1));

  49462. }

  49463. 

  49464. /* forward declaration */

  49465. static void pcache1Destroy(sqlite3_pcache *p);

  49466. 

  49467. /*

  49468. ** Implementation of the sqlite3_pcache.xCreate method.

  49469. **

  49470. ** Allocate a new cache.

  49471. */

  49472. static sqlite3_pcache *pcache1Create(int szPage, int szExtra, int bPurgeable){

  49473.   PCache1 *pCache;      /* The newly created page cache */

  49474.   PGroup *pGroup;       /* The group the new page cache will belong to */

  49475.   int sz;               /* Bytes of memory required to allocate the new cache */

  49476. 

  49477.   assert( (szPage & (szPage-1))==0 && szPage>=512 && szPage<=65536 );

  49478.   assert( szExtra < 300 );

  49479. 

  49480.   sz = sizeof(PCache1) + sizeof(PGroup)*pcache1.separateCache;

  49481.   pCache = (PCache1 *)sqlite3MallocZero(sz);

  49482.   if( pCache ){

  49483.     if( pcache1.separateCache ){

  49484.       pGroup = (PGroup*)&pCache[1];

  49485.       pGroup->mxPinned = 10;

  49486.     }else{

  49487.       pGroup = &pcache1.grp;

  49488.     }

  49489.     pcache1EnterMutex(pGroup);

  49490.     if( pGroup->lru.isAnchor==0 ){

  49491.       pGroup->lru.isAnchor = 1;

  49492.       pGroup->lru.pLruPrev = pGroup->lru.pLruNext = &pGroup->lru;

  49493.     }

  49494.     pCache->pGroup = pGroup;

  49495.     pCache->szPage = szPage;

  49496.     pCache->szExtra = szExtra;

  49497.     pCache->szAlloc = szPage + szExtra + ROUND8(sizeof(PgHdr1));

  49498.     pCache->bPurgeable = (bPurgeable ? 1 : 0);

  49499.     pcache1ResizeHash(pCache);

  49500.     if( bPurgeable ){

  49501.       pCache->nMin = 10;

  49502.       pGroup->nMinPage += pCache->nMin;

  49503.       pGroup->mxPinned = pGroup->nMaxPage + 10 - pGroup->nMinPage;

  49504.       pCache->pnPurgeable = &pGroup->nPurgeable;

  49505.     }else{

  49506.       pCache->pnPurgeable = &pCache->nPurgeableDummy;

  49507.     }

  49508.     pcache1LeaveMutex(pGroup);

  49509.     if( pCache->nHash==0 ){

  49510.       pcache1Destroy((sqlite3_pcache*)pCache);

  49511.       pCache = 0;

  49512.     }

  49513.   }

  49514.   return (sqlite3_pcache *)pCache;

  49515. }

  49516. 

  49517. /*

  49518. ** Implementation of the sqlite3_pcache.xCachesize method. 

  49519. **

  49520. ** Configure the cache_size limit for a cache.

  49521. */

  49522. static void pcache1Cachesize(sqlite3_pcache *p, int nMax){

  49523.   PCache1 *pCache = (PCache1 *)p;

  49524.   if( pCache->bPurgeable ){

  49525.     PGroup *pGroup = pCache->pGroup;

  49526.     pcache1EnterMutex(pGroup);

  49527.     pGroup->nMaxPage += (nMax - pCache->nMax);

  49528.     pGroup->mxPinned = pGroup->nMaxPage + 10 - pGroup->nMinPage;

  49529.     pCache->nMax = nMax;

  49530.     pCache->n90pct = pCache->nMax*9/10;

  49531.     pcache1EnforceMaxPage(pCache);

  49532.     pcache1LeaveMutex(pGroup);

  49533.   }

  49534. }

  49535. 

  49536. /*

  49537. ** Implementation of the sqlite3_pcache.xShrink method. 

  49538. **

  49539. ** Free up as much memory as possible.

  49540. */

  49541. static void pcache1Shrink(sqlite3_pcache *p){

  49542.   PCache1 *pCache = (PCache1*)p;

  49543.   if( pCache->bPurgeable ){

  49544.     PGroup *pGroup = pCache->pGroup;

  49545.     int savedMaxPage;

  49546.     pcache1EnterMutex(pGroup);

  49547.     savedMaxPage = pGroup->nMaxPage;

  49548.     pGroup->nMaxPage = 0;

  49549.     pcache1EnforceMaxPage(pCache);

  49550.     pGroup->nMaxPage = savedMaxPage;

  49551.     pcache1LeaveMutex(pGroup);

  49552.   }

  49553. }

  49554. 

  49555. /*

  49556. ** Implementation of the sqlite3_pcache.xPagecount method. 

  49557. */

  49558. static int pcache1Pagecount(sqlite3_pcache *p){

  49559.   int n;

  49560.   PCache1 *pCache = (PCache1*)p;

  49561.   pcache1EnterMutex(pCache->pGroup);

  49562.   n = pCache->nPage;

  49563.   pcache1LeaveMutex(pCache->pGroup);

  49564.   return n;

  49565. }

  49566. 

  49567. 

  49568. /*

  49569. ** Implement steps 3, 4, and 5 of the pcache1Fetch() algorithm described

  49570. ** in the header of the pcache1Fetch() procedure.

  49571. **

  49572. ** This steps are broken out into a separate procedure because they are

  49573. ** usually not needed, and by avoiding the stack initialization required

  49574. ** for these steps, the main pcache1Fetch() procedure can run faster.

  49575. */

  49576. static SQLITE_NOINLINE PgHdr1 *pcache1FetchStage2(

  49577.   PCache1 *pCache, 

  49578.   unsigned int iKey, 

  49579.   int createFlag

  49580. ){

  49581.   unsigned int nPinned;

  49582.   PGroup *pGroup = pCache->pGroup;

  49583.   PgHdr1 *pPage = 0;

  49584. 

  49585.   /* Step 3: Abort if createFlag is 1 but the cache is nearly full */

  49586.   assert( pCache->nPage >= pCache->nRecyclable );

  49587.   nPinned = pCache->nPage - pCache->nRecyclable;

  49588.   assert( pGroup->mxPinned == pGroup->nMaxPage + 10 - pGroup->nMinPage );

  49589.   assert( pCache->n90pct == pCache->nMax*9/10 );

  49590.   if( createFlag==1 && (

  49591.         nPinned>=pGroup->mxPinned

  49592.      || nPinned>=pCache->n90pct

  49593.      || (pcache1UnderMemoryPressure(pCache) && pCache->nRecyclable<nPinned)

  49594.   )){

  49595.     return 0;

  49596.   }

  49597. 

  49598.   if( pCache->nPage>=pCache->nHash ) pcache1ResizeHash(pCache);

  49599.   assert( pCache->nHash>0 && pCache->apHash );

  49600. 

  49601.   /* Step 4. Try to recycle a page. */

  49602.   if( pCache->bPurgeable

  49603.    && !pGroup->lru.pLruPrev->isAnchor

  49604.    && ((pCache->nPage+1>=pCache->nMax) || pcache1UnderMemoryPressure(pCache))

  49605.   ){

  49606.     PCache1 *pOther;

  49607.     pPage = pGroup->lru.pLruPrev;

  49608.     assert( PAGE_IS_UNPINNED(pPage) );

  49609.     pcache1RemoveFromHash(pPage, 0);

  49610.     pcache1PinPage(pPage);

  49611.     pOther = pPage->pCache;

  49612.     if( pOther->szAlloc != pCache->szAlloc ){

  49613.       pcache1FreePage(pPage);

  49614.       pPage = 0;

  49615.     }else{

  49616.       pGroup->nPurgeable -= (pOther->bPurgeable - pCache->bPurgeable);

  49617.     }

  49618.   }

  49619. 

  49620.   /* Step 5. If a usable page buffer has still not been found, 

  49621.   ** attempt to allocate a new one. 

  49622.   */

  49623.   if( !pPage ){

  49624.     pPage = pcache1AllocPage(pCache, createFlag==1);

  49625.   }

  49626. 

  49627.   if( pPage ){

  49628.     unsigned int h = iKey % pCache->nHash;

  49629.     pCache->nPage++;

  49630.     pPage->iKey = iKey;

  49631.     pPage->pNext = pCache->apHash[h];

  49632.     pPage->pCache = pCache;

  49633.     pPage->pLruNext = 0;

  49634.     /* pPage->pLruPrev = 0;

  49635.     ** No need to clear pLruPrev since it is not accessed when pLruNext==0 */

  49636.     *(void **)pPage->page.pExtra = 0;

  49637.     pCache->apHash[h] = pPage;

  49638.     if( iKey>pCache->iMaxKey ){

  49639.       pCache->iMaxKey = iKey;

  49640.     }

  49641.   }

  49642.   return pPage;

  49643. }

  49644. 

  49645. /*

  49646. ** Implementation of the sqlite3_pcache.xFetch method. 

  49647. **

  49648. ** Fetch a page by key value.

  49649. **

  49650. ** Whether or not a new page may be allocated by this function depends on

  49651. ** the value of the createFlag argument.  0 means do not allocate a new

  49652. ** page.  1 means allocate a new page if space is easily available.  2 

  49653. ** means to try really hard to allocate a new page.

  49654. **

  49655. ** For a non-purgeable cache (a cache used as the storage for an in-memory

  49656. ** database) there is really no difference between createFlag 1 and 2.  So

  49657. ** the calling function (pcache.c) will never have a createFlag of 1 on

  49658. ** a non-purgeable cache.

  49659. **

  49660. ** There are three different approaches to obtaining space for a page,

  49661. ** depending on the value of parameter createFlag (which may be 0, 1 or 2).

  49662. **

  49663. **   1. Regardless of the value of createFlag, the cache is searched for a 

  49664. **      copy of the requested page. If one is found, it is returned.

  49665. **

  49666. **   2. If createFlag==0 and the page is not already in the cache, NULL is

  49667. **      returned.

  49668. **

  49669. **   3. If createFlag is 1, and the page is not already in the cache, then

  49670. **      return NULL (do not allocate a new page) if any of the following

  49671. **      conditions are true:

  49672. **

  49673. **       (a) the number of pages pinned by the cache is greater than

  49674. **           PCache1.nMax, or

  49675. **

  49676. **       (b) the number of pages pinned by the cache is greater than

  49677. **           the sum of nMax for all purgeable caches, less the sum of 

  49678. **           nMin for all other purgeable caches, or

  49679. **

  49680. **   4. If none of the first three conditions apply and the cache is marked

  49681. **      as purgeable, and if one of the following is true:

  49682. **

  49683. **       (a) The number of pages allocated for the cache is already 

  49684. **           PCache1.nMax, or

  49685. **

  49686. **       (b) The number of pages allocated for all purgeable caches is

  49687. **           already equal to or greater than the sum of nMax for all

  49688. **           purgeable caches,

  49689. **

  49690. **       (c) The system is under memory pressure and wants to avoid

  49691. **           unnecessary pages cache entry allocations

  49692. **

  49693. **      then attempt to recycle a page from the LRU list. If it is the right

  49694. **      size, return the recycled buffer. Otherwise, free the buffer and

  49695. **      proceed to step 5. 

  49696. **

  49697. **   5. Otherwise, allocate and return a new page buffer.

  49698. **

  49699. ** There are two versions of this routine.  pcache1FetchWithMutex() is

  49700. ** the general case.  pcache1FetchNoMutex() is a faster implementation for

  49701. ** the common case where pGroup->mutex is NULL.  The pcache1Fetch() wrapper

  49702. ** invokes the appropriate routine.

  49703. */

  49704. static PgHdr1 *pcache1FetchNoMutex(

  49705.   sqlite3_pcache *p, 

  49706.   unsigned int iKey, 

  49707.   int createFlag

  49708. ){

  49709.   PCache1 *pCache = (PCache1 *)p;

  49710.   PgHdr1 *pPage = 0;

  49711. 

  49712.   /* Step 1: Search the hash table for an existing entry. */

  49713.   pPage = pCache->apHash[iKey % pCache->nHash];

  49714.   while( pPage && pPage->iKey!=iKey ){ pPage = pPage->pNext; }

  49715. 

  49716.   /* Step 2: If the page was found in the hash table, then return it.

  49717.   ** If the page was not in the hash table and createFlag is 0, abort.

  49718.   ** Otherwise (page not in hash and createFlag!=0) continue with

  49719.   ** subsequent steps to try to create the page. */

  49720.   if( pPage ){

  49721.     if( PAGE_IS_UNPINNED(pPage) ){

  49722.       return pcache1PinPage(pPage);

  49723.     }else{

  49724.       return pPage;

  49725.     }

  49726.   }else if( createFlag ){

  49727.     /* Steps 3, 4, and 5 implemented by this subroutine */

  49728.     return pcache1FetchStage2(pCache, iKey, createFlag);

  49729.   }else{

  49730.     return 0;

  49731.   }

  49732. }

  49733. #if PCACHE1_MIGHT_USE_GROUP_MUTEX

  49734. static PgHdr1 *pcache1FetchWithMutex(

  49735.   sqlite3_pcache *p, 

  49736.   unsigned int iKey, 

  49737.   int createFlag

  49738. ){

  49739.   PCache1 *pCache = (PCache1 *)p;

  49740.   PgHdr1 *pPage;

  49741. 

  49742.   pcache1EnterMutex(pCache->pGroup);

  49743.   pPage = pcache1FetchNoMutex(p, iKey, createFlag);

  49744.   assert( pPage==0 || pCache->iMaxKey>=iKey );

  49745.   pcache1LeaveMutex(pCache->pGroup);

  49746.   return pPage;

  49747. }

  49748. #endif

  49749. static sqlite3_pcache_page *pcache1Fetch(

  49750.   sqlite3_pcache *p, 

  49751.   unsigned int iKey, 

  49752.   int createFlag

  49753. ){

  49754. #if PCACHE1_MIGHT_USE_GROUP_MUTEX || defined(SQLITE_DEBUG)

  49755.   PCache1 *pCache = (PCache1 *)p;

  49756. #endif

  49757. 

  49758.   assert( offsetof(PgHdr1,page)==0 );

  49759.   assert( pCache->bPurgeable || createFlag!=1 );

  49760.   assert( pCache->bPurgeable || pCache->nMin==0 );

  49761.   assert( pCache->bPurgeable==0 || pCache->nMin==10 );

  49762.   assert( pCache->nMin==0 || pCache->bPurgeable );

  49763.   assert( pCache->nHash>0 );

  49764. #if PCACHE1_MIGHT_USE_GROUP_MUTEX

  49765.   if( pCache->pGroup->mutex ){

  49766.     return (sqlite3_pcache_page*)pcache1FetchWithMutex(p, iKey, createFlag);

  49767.   }else

  49768. #endif

  49769.   {

  49770.     return (sqlite3_pcache_page*)pcache1FetchNoMutex(p, iKey, createFlag);

  49771.   }

  49772. }

  49773. 

  49774. 

  49775. /*

  49776. ** Implementation of the sqlite3_pcache.xUnpin method.

  49777. **

  49778. ** Mark a page as unpinned (eligible for asynchronous recycling).

  49779. */

  49780. static void pcache1Unpin(

  49781.   sqlite3_pcache *p, 

  49782.   sqlite3_pcache_page *pPg, 

  49783.   int reuseUnlikely

  49784. ){

  49785.   PCache1 *pCache = (PCache1 *)p;

  49786.   PgHdr1 *pPage = (PgHdr1 *)pPg;

  49787.   PGroup *pGroup = pCache->pGroup;

  49788.  

  49789.   assert( pPage->pCache==pCache );

  49790.   pcache1EnterMutex(pGroup);

  49791. 

  49792.   /* It is an error to call this function if the page is already 

  49793.   ** part of the PGroup LRU list.

  49794.   */

  49795.   assert( pPage->pLruNext==0 );

  49796.   assert( PAGE_IS_PINNED(pPage) );

  49797. 

  49798.   if( reuseUnlikely || pGroup->nPurgeable>pGroup->nMaxPage ){

  49799.     pcache1RemoveFromHash(pPage, 1);

  49800.   }else{

  49801.     /* Add the page to the PGroup LRU list. */

  49802.     PgHdr1 **ppFirst = &pGroup->lru.pLruNext;

  49803.     pPage->pLruPrev = &pGroup->lru;

  49804.     (pPage->pLruNext = *ppFirst)->pLruPrev = pPage;

  49805.     *ppFirst = pPage;

  49806.     pCache->nRecyclable++;

  49807.   }

  49808. 

  49809.   pcache1LeaveMutex(pCache->pGroup);

  49810. }

  49811. 

  49812. /*

  49813. ** Implementation of the sqlite3_pcache.xRekey method. 

  49814. */

  49815. static void pcache1Rekey(

  49816.   sqlite3_pcache *p,

  49817.   sqlite3_pcache_page *pPg,

  49818.   unsigned int iOld,

  49819.   unsigned int iNew

  49820. ){

  49821.   PCache1 *pCache = (PCache1 *)p;

  49822.   PgHdr1 *pPage = (PgHdr1 *)pPg;

  49823.   PgHdr1 **pp;

  49824.   unsigned int h; 

  49825.   assert( pPage->iKey==iOld );

  49826.   assert( pPage->pCache==pCache );

  49827. 

  49828.   pcache1EnterMutex(pCache->pGroup);

  49829. 

  49830.   h = iOld%pCache->nHash;

  49831.   pp = &pCache->apHash[h];

  49832.   while( (*pp)!=pPage ){

  49833.     pp = &(*pp)->pNext;

  49834.   }

  49835.   *pp = pPage->pNext;

  49836. 

  49837.   h = iNew%pCache->nHash;

  49838.   pPage->iKey = iNew;

  49839.   pPage->pNext = pCache->apHash[h];

  49840.   pCache->apHash[h] = pPage;

  49841.   if( iNew>pCache->iMaxKey ){

  49842.     pCache->iMaxKey = iNew;

  49843.   }

  49844. 

  49845.   pcache1LeaveMutex(pCache->pGroup);

  49846. }

  49847. 

  49848. /*

  49849. ** Implementation of the sqlite3_pcache.xTruncate method. 

  49850. **

  49851. ** Discard all unpinned pages in the cache with a page number equal to

  49852. ** or greater than parameter iLimit. Any pinned pages with a page number

  49853. ** equal to or greater than iLimit are implicitly unpinned.

  49854. */

  49855. static void pcache1Truncate(sqlite3_pcache *p, unsigned int iLimit){

  49856.   PCache1 *pCache = (PCache1 *)p;

  49857.   pcache1EnterMutex(pCache->pGroup);

  49858.   if( iLimit<=pCache->iMaxKey ){

  49859.     pcache1TruncateUnsafe(pCache, iLimit);

  49860.     pCache->iMaxKey = iLimit-1;

  49861.   }

  49862.   pcache1LeaveMutex(pCache->pGroup);

  49863. }

  49864. 

  49865. /*

  49866. ** Implementation of the sqlite3_pcache.xDestroy method. 

  49867. **

  49868. ** Destroy a cache allocated using pcache1Create().

  49869. */

  49870. static void pcache1Destroy(sqlite3_pcache *p){

  49871.   PCache1 *pCache = (PCache1 *)p;

  49872.   PGroup *pGroup = pCache->pGroup;

  49873.   assert( pCache->bPurgeable || (pCache->nMax==0 && pCache->nMin==0) );

  49874.   pcache1EnterMutex(pGroup);

  49875.   if( pCache->nPage ) pcache1TruncateUnsafe(pCache, 0);

  49876.   assert( pGroup->nMaxPage >= pCache->nMax );

  49877.   pGroup->nMaxPage -= pCache->nMax;

  49878.   assert( pGroup->nMinPage >= pCache->nMin );

  49879.   pGroup->nMinPage -= pCache->nMin;

  49880.   pGroup->mxPinned = pGroup->nMaxPage + 10 - pGroup->nMinPage;

  49881.   pcache1EnforceMaxPage(pCache);

  49882.   pcache1LeaveMutex(pGroup);

  49883.   sqlite3_free(pCache->pBulk);

  49884.   sqlite3_free(pCache->apHash);

  49885.   sqlite3_free(pCache);

  49886. }

  49887. 

  49888. /*

  49889. ** This function is called during initialization (sqlite3_initialize()) to

  49890. ** install the default pluggable cache module, assuming the user has not

  49891. ** already provided an alternative.

  49892. */

  49893. SQLITE_PRIVATE void sqlite3PCacheSetDefault(void){

  49894.   static const sqlite3_pcache_methods2 defaultMethods = {

  49895.     1,                       /* iVersion */

  49896.     0,                       /* pArg */

  49897.     pcache1Init,             /* xInit */

  49898.     pcache1Shutdown,         /* xShutdown */

  49899.     pcache1Create,           /* xCreate */

  49900.     pcache1Cachesize,        /* xCachesize */

  49901.     pcache1Pagecount,        /* xPagecount */

  49902.     pcache1Fetch,            /* xFetch */

  49903.     pcache1Unpin,            /* xUnpin */

  49904.     pcache1Rekey,            /* xRekey */

  49905.     pcache1Truncate,         /* xTruncate */

  49906.     pcache1Destroy,          /* xDestroy */

  49907.     pcache1Shrink            /* xShrink */

  49908.   };

  49909.   sqlite3_config(SQLITE_CONFIG_PCACHE2, &defaultMethods);

  49910. }

  49911. 

  49912. /*

  49913. ** Return the size of the header on each page of this PCACHE implementation.

  49914. */

  49915. SQLITE_PRIVATE int sqlite3HeaderSizePcache1(void){ return ROUND8(sizeof(PgHdr1)); }

  49916. 

  49917. /*

  49918. ** Return the global mutex used by this PCACHE implementation.  The

  49919. ** sqlite3_status() routine needs access to this mutex.

  49920. */

  49921. SQLITE_PRIVATE sqlite3_mutex *sqlite3Pcache1Mutex(void){

  49922.   return pcache1.mutex;

  49923. }

  49924. 

  49925. #ifdef SQLITE_ENABLE_MEMORY_MANAGEMENT

  49926. /*

  49927. ** This function is called to free superfluous dynamically allocated memory

  49928. ** held by the pager system. Memory in use by any SQLite pager allocated

  49929. ** by the current thread may be sqlite3_free()ed.

  49930. **

  49931. ** nReq is the number of bytes of memory required. Once this much has

  49932. ** been released, the function returns. The return value is the total number 

  49933. ** of bytes of memory released.

  49934. */

  49935. SQLITE_PRIVATE int sqlite3PcacheReleaseMemory(int nReq){

  49936.   int nFree = 0;

  49937.   assert( sqlite3_mutex_notheld(pcache1.grp.mutex) );

  49938.   assert( sqlite3_mutex_notheld(pcache1.mutex) );

  49939.   if( sqlite3GlobalConfig.pPage==0 ){

  49940.     PgHdr1 *p;

  49941.     pcache1EnterMutex(&pcache1.grp);

  49942.     while( (nReq<0 || nFree<nReq)

  49943.        &&  (p=pcache1.grp.lru.pLruPrev)!=0

  49944.        &&  p->isAnchor==0

  49945.     ){

  49946.       nFree += pcache1MemSize(p->page.pBuf);

  49947. #ifdef SQLITE_PCACHE_SEPARATE_HEADER

  49948.       nFree += sqlite3MemSize(p);

  49949. #endif

  49950.       assert( PAGE_IS_UNPINNED(p) );

  49951.       pcache1PinPage(p);

  49952.       pcache1RemoveFromHash(p, 1);

  49953.     }

  49954.     pcache1LeaveMutex(&pcache1.grp);

  49955.   }

  49956.   return nFree;

  49957. }

  49958. #endif /* SQLITE_ENABLE_MEMORY_MANAGEMENT */

  49959. 

  49960. #ifdef SQLITE_TEST

  49961. /*

  49962. ** This function is used by test procedures to inspect the internal state

  49963. ** of the global cache.

  49964. */

  49965. SQLITE_PRIVATE void sqlite3PcacheStats(

  49966.   int *pnCurrent,      /* OUT: Total number of pages cached */

  49967.   int *pnMax,          /* OUT: Global maximum cache size */

  49968.   int *pnMin,          /* OUT: Sum of PCache1.nMin for purgeable caches */

  49969.   int *pnRecyclable    /* OUT: Total number of pages available for recycling */

  49970. ){

  49971.   PgHdr1 *p;

  49972.   int nRecyclable = 0;

  49973.   for(p=pcache1.grp.lru.pLruNext; p && !p->isAnchor; p=p->pLruNext){

  49974.     assert( PAGE_IS_UNPINNED(p) );

  49975.     nRecyclable++;

  49976.   }

  49977.   *pnCurrent = pcache1.grp.nPurgeable;

  49978.   *pnMax = (int)pcache1.grp.nMaxPage;

  49979.   *pnMin = (int)pcache1.grp.nMinPage;

  49980.   *pnRecyclable = nRecyclable;

  49981. }

  49982. #endif

  49983. 

  49984. /************** End of pcache1.c *********************************************/

  49985. /************** Begin file rowset.c ******************************************/

  49986. /*

  49987. ** 2008 December 3

  49988. **

  49989. ** The author disclaims copyright to this source code.  In place of

  49990. ** a legal notice, here is a blessing:

  49991. **

  49992. **    May you do good and not evil.

  49993. **    May you find forgiveness for yourself and forgive others.

  49994. **    May you share freely, never taking more than you give.

  49995. **

  49996. *************************************************************************

  49997. **

  49998. ** This module implements an object we call a "RowSet".

  49999. **

  50000. ** The RowSet object is a collection of rowids.  Rowids

  50001. ** are inserted into the RowSet in an arbitrary order.  Inserts

  50002. ** can be intermixed with tests to see if a given rowid has been

  50003. ** previously inserted into the RowSet.

  50004. **

  50005. ** After all inserts are finished, it is possible to extract the

  50006. ** elements of the RowSet in sorted order.  Once this extraction

  50007. ** process has started, no new elements may be inserted.

  50008. **

  50009. ** Hence, the primitive operations for a RowSet are:

  50010. **

  50011. **    CREATE

  50012. **    INSERT

  50013. **    TEST

  50014. **    SMALLEST

  50015. **    DESTROY

  50016. **

  50017. ** The CREATE and DESTROY primitives are the constructor and destructor,

  50018. ** obviously.  The INSERT primitive adds a new element to the RowSet.

  50019. ** TEST checks to see if an element is already in the RowSet.  SMALLEST

  50020. ** extracts the least value from the RowSet.

  50021. **

  50022. ** The INSERT primitive might allocate additional memory.  Memory is

  50023. ** allocated in chunks so most INSERTs do no allocation.  There is an 

  50024. ** upper bound on the size of allocated memory.  No memory is freed

  50025. ** until DESTROY.

  50026. **

  50027. ** The TEST primitive includes a "batch" number.  The TEST primitive

  50028. ** will only see elements that were inserted before the last change

  50029. ** in the batch number.  In other words, if an INSERT occurs between

  50030. ** two TESTs where the TESTs have the same batch nubmer, then the

  50031. ** value added by the INSERT will not be visible to the second TEST.

  50032. ** The initial batch number is zero, so if the very first TEST contains

  50033. ** a non-zero batch number, it will see all prior INSERTs.

  50034. **

  50035. ** No INSERTs may occurs after a SMALLEST.  An assertion will fail if

  50036. ** that is attempted.

  50037. **

  50038. ** The cost of an INSERT is roughly constant.  (Sometimes new memory

  50039. ** has to be allocated on an INSERT.)  The cost of a TEST with a new

  50040. ** batch number is O(NlogN) where N is the number of elements in the RowSet.

  50041. ** The cost of a TEST using the same batch number is O(logN).  The cost

  50042. ** of the first SMALLEST is O(NlogN).  Second and subsequent SMALLEST

  50043. ** primitives are constant time.  The cost of DESTROY is O(N).

  50044. **

  50045. ** TEST and SMALLEST may not be used by the same RowSet.  This used to

  50046. ** be possible, but the feature was not used, so it was removed in order

  50047. ** to simplify the code.

  50048. */

  50049. /* #include "sqliteInt.h" */

  50050. 

  50051. 

  50052. /*

  50053. ** Target size for allocation chunks.

  50054. */

  50055. #define ROWSET_ALLOCATION_SIZE 1024

  50056. 

  50057. /*

  50058. ** The number of rowset entries per allocation chunk.

  50059. */

  50060. #define ROWSET_ENTRY_PER_CHUNK  \

  50061.                        ((ROWSET_ALLOCATION_SIZE-8)/sizeof(struct RowSetEntry))

  50062. 

  50063. /*

  50064. ** Each entry in a RowSet is an instance of the following object.

  50065. **

  50066. ** This same object is reused to store a linked list of trees of RowSetEntry

  50067. ** objects.  In that alternative use, pRight points to the next entry

  50068. ** in the list, pLeft points to the tree, and v is unused.  The

  50069. ** RowSet.pForest value points to the head of this forest list.

  50070. */

  50071. struct RowSetEntry {            

  50072.   i64 v;                        /* ROWID value for this entry */

  50073.   struct RowSetEntry *pRight;   /* Right subtree (larger entries) or list */

  50074.   struct RowSetEntry *pLeft;    /* Left subtree (smaller entries) */

  50075. };

  50076. 

  50077. /*

  50078. ** RowSetEntry objects are allocated in large chunks (instances of the

  50079. ** following structure) to reduce memory allocation overhead.  The

  50080. ** chunks are kept on a linked list so that they can be deallocated

  50081. ** when the RowSet is destroyed.

  50082. */

  50083. struct RowSetChunk {

  50084.   struct RowSetChunk *pNextChunk;        /* Next chunk on list of them all */

  50085.   struct RowSetEntry aEntry[ROWSET_ENTRY_PER_CHUNK]; /* Allocated entries */

  50086. };

  50087. 

  50088. /*

  50089. ** A RowSet in an instance of the following structure.

  50090. **

  50091. ** A typedef of this structure if found in sqliteInt.h.

  50092. */

  50093. struct RowSet {

  50094.   struct RowSetChunk *pChunk;    /* List of all chunk allocations */

  50095.   sqlite3 *db;                   /* The database connection */

  50096.   struct RowSetEntry *pEntry;    /* List of entries using pRight */

  50097.   struct RowSetEntry *pLast;     /* Last entry on the pEntry list */

  50098.   struct RowSetEntry *pFresh;    /* Source of new entry objects */

  50099.   struct RowSetEntry *pForest;   /* List of binary trees of entries */

  50100.   u16 nFresh;                    /* Number of objects on pFresh */

  50101.   u16 rsFlags;                   /* Various flags */

  50102.   int iBatch;                    /* Current insert batch */

  50103. };

  50104. 

  50105. /*

  50106. ** Allowed values for RowSet.rsFlags

  50107. */

  50108. #define ROWSET_SORTED  0x01   /* True if RowSet.pEntry is sorted */

  50109. #define ROWSET_NEXT    0x02   /* True if sqlite3RowSetNext() has been called */

  50110. 

  50111. /*

  50112. ** Allocate a RowSet object.  Return NULL if a memory allocation

  50113. ** error occurs.

  50114. */

  50115. SQLITE_PRIVATE RowSet *sqlite3RowSetInit(sqlite3 *db){

  50116.   RowSet *p = sqlite3DbMallocRawNN(db, sizeof(*p));

  50117.   if( p ){

  50118.     int N = sqlite3DbMallocSize(db, p);

  50119.     p->pChunk = 0;

  50120.     p->db = db;

  50121.     p->pEntry = 0;

  50122.     p->pLast = 0;

  50123.     p->pForest = 0;

  50124.     p->pFresh = (struct RowSetEntry*)(ROUND8(sizeof(*p)) + (char*)p);

  50125.     p->nFresh = (u16)((N - ROUND8(sizeof(*p)))/sizeof(struct RowSetEntry));

  50126.     p->rsFlags = ROWSET_SORTED;

  50127.     p->iBatch = 0;

  50128.   }

  50129.   return p;

  50130. }

  50131. 

  50132. /*

  50133. ** Deallocate all chunks from a RowSet.  This frees all memory that

  50134. ** the RowSet has allocated over its lifetime.  This routine is

  50135. ** the destructor for the RowSet.

  50136. */

  50137. SQLITE_PRIVATE void sqlite3RowSetClear(void *pArg){

  50138.   RowSet *p = (RowSet*)pArg;

  50139.   struct RowSetChunk *pChunk, *pNextChunk;

  50140.   for(pChunk=p->pChunk; pChunk; pChunk = pNextChunk){

  50141.     pNextChunk = pChunk->pNextChunk;

  50142.     sqlite3DbFree(p->db, pChunk);

  50143.   }

  50144.   p->pChunk = 0;

  50145.   p->nFresh = 0;

  50146.   p->pEntry = 0;

  50147.   p->pLast = 0;

  50148.   p->pForest = 0;

  50149.   p->rsFlags = ROWSET_SORTED;

  50150. }

  50151. 

  50152. /*

  50153. ** Deallocate all chunks from a RowSet.  This frees all memory that

  50154. ** the RowSet has allocated over its lifetime.  This routine is

  50155. ** the destructor for the RowSet.

  50156. */

  50157. SQLITE_PRIVATE void sqlite3RowSetDelete(void *pArg){

  50158.   sqlite3RowSetClear(pArg);

  50159.   sqlite3DbFree(((RowSet*)pArg)->db, pArg);

  50160. }

  50161. 

  50162. /*

  50163. ** Allocate a new RowSetEntry object that is associated with the

  50164. ** given RowSet.  Return a pointer to the new and completely uninitialized

  50165. ** objected.

  50166. **

  50167. ** In an OOM situation, the RowSet.db->mallocFailed flag is set and this

  50168. ** routine returns NULL.

  50169. */

  50170. static struct RowSetEntry *rowSetEntryAlloc(RowSet *p){

  50171.   assert( p!=0 );

  50172.   if( p->nFresh==0 ){  /*OPTIMIZATION-IF-FALSE*/

  50173.     /* We could allocate a fresh RowSetEntry each time one is needed, but it

  50174.     ** is more efficient to pull a preallocated entry from the pool */

  50175.     struct RowSetChunk *pNew;

  50176.     pNew = sqlite3DbMallocRawNN(p->db, sizeof(*pNew));

  50177.     if( pNew==0 ){

  50178.       return 0;

  50179.     }

  50180.     pNew->pNextChunk = p->pChunk;

  50181.     p->pChunk = pNew;

  50182.     p->pFresh = pNew->aEntry;

  50183.     p->nFresh = ROWSET_ENTRY_PER_CHUNK;

  50184.   }

  50185.   p->nFresh--;

  50186.   return p->pFresh++;

  50187. }

  50188. 

  50189. /*

  50190. ** Insert a new value into a RowSet.

  50191. **

  50192. ** The mallocFailed flag of the database connection is set if a

  50193. ** memory allocation fails.

  50194. */

  50195. SQLITE_PRIVATE void sqlite3RowSetInsert(RowSet *p, i64 rowid){

  50196.   struct RowSetEntry *pEntry;  /* The new entry */

  50197.   struct RowSetEntry *pLast;   /* The last prior entry */

  50198. 

  50199.   /* This routine is never called after sqlite3RowSetNext() */

  50200.   assert( p!=0 && (p->rsFlags & ROWSET_NEXT)==0 );

  50201. 

  50202.   pEntry = rowSetEntryAlloc(p);

  50203.   if( pEntry==0 ) return;

  50204.   pEntry->v = rowid;

  50205.   pEntry->pRight = 0;

  50206.   pLast = p->pLast;

  50207.   if( pLast ){

  50208.     if( rowid<=pLast->v ){  /*OPTIMIZATION-IF-FALSE*/

  50209.       /* Avoid unnecessary sorts by preserving the ROWSET_SORTED flags

  50210.       ** where possible */

  50211.       p->rsFlags &= ~ROWSET_SORTED;

  50212.     }

  50213.     pLast->pRight = pEntry;

  50214.   }else{

  50215.     p->pEntry = pEntry;

  50216.   }

  50217.   p->pLast = pEntry;

  50218. }

  50219. 

  50220. /*

  50221. ** Merge two lists of RowSetEntry objects.  Remove duplicates.

  50222. **

  50223. ** The input lists are connected via pRight pointers and are 

  50224. ** assumed to each already be in sorted order.

  50225. */

  50226. static struct RowSetEntry *rowSetEntryMerge(

  50227.   struct RowSetEntry *pA,    /* First sorted list to be merged */

  50228.   struct RowSetEntry *pB     /* Second sorted list to be merged */

  50229. ){

  50230.   struct RowSetEntry head;

  50231.   struct RowSetEntry *pTail;

  50232. 

  50233.   pTail = &head;

  50234.   assert( pA!=0 && pB!=0 );

  50235.   for(;;){

  50236.     assert( pA->pRight==0 || pA->v<=pA->pRight->v );

  50237.     assert( pB->pRight==0 || pB->v<=pB->pRight->v );

  50238.     if( pA->v<=pB->v ){

  50239.       if( pA->v<pB->v ) pTail = pTail->pRight = pA;

  50240.       pA = pA->pRight;

  50241.       if( pA==0 ){

  50242.         pTail->pRight = pB;

  50243.         break;

  50244.       }

  50245.     }else{

  50246.       pTail = pTail->pRight = pB;

  50247.       pB = pB->pRight;

  50248.       if( pB==0 ){

  50249.         pTail->pRight = pA;

  50250.         break;

  50251.       }

  50252.     }

  50253.   }

  50254.   return head.pRight;

  50255. }

  50256. 

  50257. /*

  50258. ** Sort all elements on the list of RowSetEntry objects into order of

  50259. ** increasing v.

  50260. */ 

  50261. static struct RowSetEntry *rowSetEntrySort(struct RowSetEntry *pIn){

  50262.   unsigned int i;

  50263.   struct RowSetEntry *pNext, *aBucket[40];

  50264. 

  50265.   memset(aBucket, 0, sizeof(aBucket));

  50266.   while( pIn ){

  50267.     pNext = pIn->pRight;

  50268.     pIn->pRight = 0;

  50269.     for(i=0; aBucket[i]; i++){

  50270.       pIn = rowSetEntryMerge(aBucket[i], pIn);

  50271.       aBucket[i] = 0;

  50272.     }

  50273.     aBucket[i] = pIn;

  50274.     pIn = pNext;

  50275.   }

  50276.   pIn = aBucket[0];

  50277.   for(i=1; i<sizeof(aBucket)/sizeof(aBucket[0]); i++){

  50278.     if( aBucket[i]==0 ) continue;

  50279.     pIn = pIn ? rowSetEntryMerge(pIn, aBucket[i]) : aBucket[i];

  50280.   }

  50281.   return pIn;

  50282. }

  50283. 

  50284. 

  50285. /*

  50286. ** The input, pIn, is a binary tree (or subtree) of RowSetEntry objects.

  50287. ** Convert this tree into a linked list connected by the pRight pointers

  50288. ** and return pointers to the first and last elements of the new list.

  50289. */

  50290. static void rowSetTreeToList(

  50291.   struct RowSetEntry *pIn,         /* Root of the input tree */

  50292.   struct RowSetEntry **ppFirst,    /* Write head of the output list here */

  50293.   struct RowSetEntry **ppLast      /* Write tail of the output list here */

  50294. ){

  50295.   assert( pIn!=0 );

  50296.   if( pIn->pLeft ){

  50297.     struct RowSetEntry *p;

  50298.     rowSetTreeToList(pIn->pLeft, ppFirst, &p);

  50299.     p->pRight = pIn;

  50300.   }else{

  50301.     *ppFirst = pIn;

  50302.   }

  50303.   if( pIn->pRight ){

  50304.     rowSetTreeToList(pIn->pRight, &pIn->pRight, ppLast);

  50305.   }else{

  50306.     *ppLast = pIn;

  50307.   }

  50308.   assert( (*ppLast)->pRight==0 );

  50309. }

  50310. 

  50311. 

  50312. /*

  50313. ** Convert a sorted list of elements (connected by pRight) into a binary

  50314. ** tree with depth of iDepth.  A depth of 1 means the tree contains a single

  50315. ** node taken from the head of *ppList.  A depth of 2 means a tree with

  50316. ** three nodes.  And so forth.

  50317. **

  50318. ** Use as many entries from the input list as required and update the

  50319. ** *ppList to point to the unused elements of the list.  If the input

  50320. ** list contains too few elements, then construct an incomplete tree

  50321. ** and leave *ppList set to NULL.

  50322. **

  50323. ** Return a pointer to the root of the constructed binary tree.

  50324. */

  50325. static struct RowSetEntry *rowSetNDeepTree(

  50326.   struct RowSetEntry **ppList,

  50327.   int iDepth

  50328. ){

  50329.   struct RowSetEntry *p;         /* Root of the new tree */

  50330.   struct RowSetEntry *pLeft;     /* Left subtree */

  50331.   if( *ppList==0 ){ /*OPTIMIZATION-IF-TRUE*/

  50332.     /* Prevent unnecessary deep recursion when we run out of entries */

  50333.     return 0; 

  50334.   }

  50335.   if( iDepth>1 ){   /*OPTIMIZATION-IF-TRUE*/

  50336.     /* This branch causes a *balanced* tree to be generated.  A valid tree

  50337.     ** is still generated without this branch, but the tree is wildly

  50338.     ** unbalanced and inefficient. */

  50339.     pLeft = rowSetNDeepTree(ppList, iDepth-1);

  50340.     p = *ppList;

  50341.     if( p==0 ){     /*OPTIMIZATION-IF-FALSE*/

  50342.       /* It is safe to always return here, but the resulting tree

  50343.       ** would be unbalanced */

  50344.       return pLeft;

  50345.     }

  50346.     p->pLeft = pLeft;

  50347.     *ppList = p->pRight;

  50348.     p->pRight = rowSetNDeepTree(ppList, iDepth-1);

  50349.   }else{

  50350.     p = *ppList;

  50351.     *ppList = p->pRight;

  50352.     p->pLeft = p->pRight = 0;

  50353.   }

  50354.   return p;

  50355. }

  50356. 

  50357. /*

  50358. ** Convert a sorted list of elements into a binary tree. Make the tree

  50359. ** as deep as it needs to be in order to contain the entire list.

  50360. */

  50361. static struct RowSetEntry *rowSetListToTree(struct RowSetEntry *pList){

  50362.   int iDepth;           /* Depth of the tree so far */

  50363.   struct RowSetEntry *p;       /* Current tree root */

  50364.   struct RowSetEntry *pLeft;   /* Left subtree */

  50365. 

  50366.   assert( pList!=0 );

  50367.   p = pList;

  50368.   pList = p->pRight;

  50369.   p->pLeft = p->pRight = 0;

  50370.   for(iDepth=1; pList; iDepth++){

  50371.     pLeft = p;

  50372.     p = pList;

  50373.     pList = p->pRight;

  50374.     p->pLeft = pLeft;

  50375.     p->pRight = rowSetNDeepTree(&pList, iDepth);

  50376.   }

  50377.   return p;

  50378. }

  50379. 

  50380. /*

  50381. ** Extract the smallest element from the RowSet.

  50382. ** Write the element into *pRowid.  Return 1 on success.  Return

  50383. ** 0 if the RowSet is already empty.

  50384. **

  50385. ** After this routine has been called, the sqlite3RowSetInsert()

  50386. ** routine may not be called again.

  50387. **

  50388. ** This routine may not be called after sqlite3RowSetTest() has

  50389. ** been used.  Older versions of RowSet allowed that, but as the

  50390. ** capability was not used by the code generator, it was removed

  50391. ** for code economy.

  50392. */

  50393. SQLITE_PRIVATE int sqlite3RowSetNext(RowSet *p, i64 *pRowid){

  50394.   assert( p!=0 );

  50395.   assert( p->pForest==0 );  /* Cannot be used with sqlite3RowSetText() */

  50396. 

  50397.   /* Merge the forest into a single sorted list on first call */

  50398.   if( (p->rsFlags & ROWSET_NEXT)==0 ){  /*OPTIMIZATION-IF-FALSE*/

  50399.     if( (p->rsFlags & ROWSET_SORTED)==0 ){  /*OPTIMIZATION-IF-FALSE*/

  50400.       p->pEntry = rowSetEntrySort(p->pEntry);

  50401.     }

  50402.     p->rsFlags |= ROWSET_SORTED|ROWSET_NEXT;

  50403.   }

  50404. 

  50405.   /* Return the next entry on the list */

  50406.   if( p->pEntry ){

  50407.     *pRowid = p->pEntry->v;

  50408.     p->pEntry = p->pEntry->pRight;

  50409.     if( p->pEntry==0 ){ /*OPTIMIZATION-IF-TRUE*/

  50410.       /* Free memory immediately, rather than waiting on sqlite3_finalize() */

  50411.       sqlite3RowSetClear(p);

  50412.     }

  50413.     return 1;

  50414.   }else{

  50415.     return 0;

  50416.   }

  50417. }

  50418. 

  50419. /*

  50420. ** Check to see if element iRowid was inserted into the rowset as

  50421. ** part of any insert batch prior to iBatch.  Return 1 or 0.

  50422. **

  50423. ** If this is the first test of a new batch and if there exist entries

  50424. ** on pRowSet->pEntry, then sort those entries into the forest at

  50425. ** pRowSet->pForest so that they can be tested.

  50426. */

  50427. SQLITE_PRIVATE int sqlite3RowSetTest(RowSet *pRowSet, int iBatch, sqlite3_int64 iRowid){

  50428.   struct RowSetEntry *p, *pTree;

  50429. 

  50430.   /* This routine is never called after sqlite3RowSetNext() */

  50431.   assert( pRowSet!=0 && (pRowSet->rsFlags & ROWSET_NEXT)==0 );

  50432. 

  50433.   /* Sort entries into the forest on the first test of a new batch.

  50434.   ** To save unnecessary work, only do this when the batch number changes.

  50435.   */

  50436.   if( iBatch!=pRowSet->iBatch ){  /*OPTIMIZATION-IF-FALSE*/

  50437.     p = pRowSet->pEntry;

  50438.     if( p ){

  50439.       struct RowSetEntry **ppPrevTree = &pRowSet->pForest;

  50440.       if( (pRowSet->rsFlags & ROWSET_SORTED)==0 ){ /*OPTIMIZATION-IF-FALSE*/

  50441.         /* Only sort the current set of entiries if they need it */

  50442.         p = rowSetEntrySort(p);

  50443.       }

  50444.       for(pTree = pRowSet->pForest; pTree; pTree=pTree->pRight){

  50445.         ppPrevTree = &pTree->pRight;

  50446.         if( pTree->pLeft==0 ){

  50447.           pTree->pLeft = rowSetListToTree(p);

  50448.           break;

  50449.         }else{

  50450.           struct RowSetEntry *pAux, *pTail;

  50451.           rowSetTreeToList(pTree->pLeft, &pAux, &pTail);

  50452.           pTree->pLeft = 0;

  50453.           p = rowSetEntryMerge(pAux, p);

  50454.         }

  50455.       }

  50456.       if( pTree==0 ){

  50457.         *ppPrevTree = pTree = rowSetEntryAlloc(pRowSet);

  50458.         if( pTree ){

  50459.           pTree->v = 0;

  50460.           pTree->pRight = 0;

  50461.           pTree->pLeft = rowSetListToTree(p);

  50462.         }

  50463.       }

  50464.       pRowSet->pEntry = 0;

  50465.       pRowSet->pLast = 0;

  50466.       pRowSet->rsFlags |= ROWSET_SORTED;

  50467.     }

  50468.     pRowSet->iBatch = iBatch;

  50469.   }

  50470. 

  50471.   /* Test to see if the iRowid value appears anywhere in the forest.

  50472.   ** Return 1 if it does and 0 if not.

  50473.   */

  50474.   for(pTree = pRowSet->pForest; pTree; pTree=pTree->pRight){

  50475.     p = pTree->pLeft;

  50476.     while( p ){

  50477.       if( p->v<iRowid ){

  50478.         p = p->pRight;

  50479.       }else if( p->v>iRowid ){

  50480.         p = p->pLeft;

  50481.       }else{

  50482.         return 1;

  50483.       }

  50484.     }

  50485.   }

  50486.   return 0;

  50487. }

  50488. 

  50489. /************** End of rowset.c **********************************************/

  50490. /************** Begin file pager.c *******************************************/

  50491. /*

  50492. ** 2001 September 15

  50493. **

  50494. ** The author disclaims copyright to this source code.  In place of

  50495. ** a legal notice, here is a blessing:

  50496. **

  50497. **    May you do good and not evil.

  50498. **    May you find forgiveness for yourself and forgive others.

  50499. **    May you share freely, never taking more than you give.

  50500. **

  50501. *************************************************************************

  50502. ** This is the implementation of the page cache subsystem or "pager".

  50503. ** 

  50504. ** The pager is used to access a database disk file.  It implements

  50505. ** atomic commit and rollback through the use of a journal file that

  50506. ** is separate from the database file.  The pager also implements file

  50507. ** locking to prevent two processes from writing the same database

  50508. ** file simultaneously, or one process from reading the database while

  50509. ** another is writing.

  50510. */

  50511. #ifndef SQLITE_OMIT_DISKIO

  50512. /* #include "sqliteInt.h" */

  50513. /************** Include wal.h in the middle of pager.c ***********************/

  50514. /************** Begin file wal.h *********************************************/

  50515. /*

  50516. ** 2010 February 1

  50517. **

  50518. ** The author disclaims copyright to this source code.  In place of

  50519. ** a legal notice, here is a blessing:

  50520. **

  50521. **    May you do good and not evil.

  50522. **    May you find forgiveness for yourself and forgive others.

  50523. **    May you share freely, never taking more than you give.

  50524. **

  50525. *************************************************************************

  50526. ** This header file defines the interface to the write-ahead logging 

  50527. ** system. Refer to the comments below and the header comment attached to 

  50528. ** the implementation of each function in log.c for further details.

  50529. */

  50530. 

  50531. #ifndef SQLITE_WAL_H

  50532. #define SQLITE_WAL_H

  50533. 

  50534. /* #include "sqliteInt.h" */

  50535. 

  50536. /* Macros for extracting appropriate sync flags for either transaction

  50537. ** commits (WAL_SYNC_FLAGS(X)) or for checkpoint ops (CKPT_SYNC_FLAGS(X)):

  50538. */

  50539. #define WAL_SYNC_FLAGS(X)   ((X)&0x03)

  50540. #define CKPT_SYNC_FLAGS(X)  (((X)>>2)&0x03)

  50541. 

  50542. #ifdef SQLITE_OMIT_WAL

  50543. # define sqlite3WalOpen(x,y,z)                   0

  50544. # define sqlite3WalLimit(x,y)

  50545. # define sqlite3WalClose(v,w,x,y,z)              0

  50546. # define sqlite3WalBeginReadTransaction(y,z)     0

  50547. # define sqlite3WalEndReadTransaction(z)

  50548. # define sqlite3WalDbsize(y)                     0

  50549. # define sqlite3WalBeginWriteTransaction(y)      0

  50550. # define sqlite3WalEndWriteTransaction(x)        0

  50551. # define sqlite3WalUndo(x,y,z)                   0

  50552. # define sqlite3WalSavepoint(y,z)

  50553. # define sqlite3WalSavepointUndo(y,z)            0

  50554. # define sqlite3WalFrames(u,v,w,x,y,z)           0

  50555. # define sqlite3WalCheckpoint(q,r,s,t,u,v,w,x,y,z) 0

  50556. # define sqlite3WalCallback(z)                   0

  50557. # define sqlite3WalExclusiveMode(y,z)            0

  50558. # define sqlite3WalHeapMemory(z)                 0

  50559. # define sqlite3WalFramesize(z)                  0

  50560. # define sqlite3WalFindFrame(x,y,z)              0

  50561. # define sqlite3WalFile(x)                       0

  50562. #else

  50563. 

  50564. #define WAL_SAVEPOINT_NDATA 4

  50565. 

  50566. /* Connection to a write-ahead log (WAL) file. 

  50567. ** There is one object of this type for each pager. 

  50568. */

  50569. typedef struct Wal Wal;

  50570. 

  50571. /* Open and close a connection to a write-ahead log. */

  50572. SQLITE_PRIVATE int sqlite3WalOpen(sqlite3_vfs*, sqlite3_file*, const char *, int, i64, Wal**);

  50573. SQLITE_PRIVATE int sqlite3WalClose(Wal *pWal, sqlite3*, int sync_flags, int, u8 *);

  50574. 

  50575. /* Set the limiting size of a WAL file. */

  50576. SQLITE_PRIVATE void sqlite3WalLimit(Wal*, i64);

  50577. 

  50578. /* Used by readers to open (lock) and close (unlock) a snapshot.  A 

  50579. ** snapshot is like a read-transaction.  It is the state of the database

  50580. ** at an instant in time.  sqlite3WalOpenSnapshot gets a read lock and

  50581. ** preserves the current state even if the other threads or processes

  50582. ** write to or checkpoint the WAL.  sqlite3WalCloseSnapshot() closes the

  50583. ** transaction and releases the lock.

  50584. */

  50585. SQLITE_PRIVATE int sqlite3WalBeginReadTransaction(Wal *pWal, int *);

  50586. SQLITE_PRIVATE void sqlite3WalEndReadTransaction(Wal *pWal);

  50587. 

  50588. /* Read a page from the write-ahead log, if it is present. */

  50589. SQLITE_PRIVATE int sqlite3WalFindFrame(Wal *, Pgno, u32 *);

  50590. SQLITE_PRIVATE int sqlite3WalReadFrame(Wal *, u32, int, u8 *);

  50591. 

  50592. /* If the WAL is not empty, return the size of the database. */

  50593. SQLITE_PRIVATE Pgno sqlite3WalDbsize(Wal *pWal);

  50594. 

  50595. /* Obtain or release the WRITER lock. */

  50596. SQLITE_PRIVATE int sqlite3WalBeginWriteTransaction(Wal *pWal);

  50597. SQLITE_PRIVATE int sqlite3WalEndWriteTransaction(Wal *pWal);

  50598. 

  50599. /* Undo any frames written (but not committed) to the log */

  50600. SQLITE_PRIVATE int sqlite3WalUndo(Wal *pWal, int (*xUndo)(void *, Pgno), void *pUndoCtx);

  50601. 

  50602. /* Return an integer that records the current (uncommitted) write

  50603. ** position in the WAL */

  50604. SQLITE_PRIVATE void sqlite3WalSavepoint(Wal *pWal, u32 *aWalData);

  50605. 

  50606. /* Move the write position of the WAL back to iFrame.  Called in

  50607. ** response to a ROLLBACK TO command. */

  50608. SQLITE_PRIVATE int sqlite3WalSavepointUndo(Wal *pWal, u32 *aWalData);

  50609. 

  50610. /* Write a frame or frames to the log. */

  50611. SQLITE_PRIVATE int sqlite3WalFrames(Wal *pWal, int, PgHdr *, Pgno, int, int);

  50612. 

  50613. /* Copy pages from the log to the database file */ 

  50614. SQLITE_PRIVATE int sqlite3WalCheckpoint(

  50615.   Wal *pWal,                      /* Write-ahead log connection */

  50616.   sqlite3 *db,                    /* Check this handle's interrupt flag */

  50617.   int eMode,                      /* One of PASSIVE, FULL and RESTART */

  50618.   int (*xBusy)(void*),            /* Function to call when busy */

  50619.   void *pBusyArg,                 /* Context argument for xBusyHandler */

  50620.   int sync_flags,                 /* Flags to sync db file with (or 0) */

  50621.   int nBuf,                       /* Size of buffer nBuf */

  50622.   u8 *zBuf,                       /* Temporary buffer to use */

  50623.   int *pnLog,                     /* OUT: Number of frames in WAL */

  50624.   int *pnCkpt                     /* OUT: Number of backfilled frames in WAL */

  50625. );

  50626. 

  50627. /* Return the value to pass to a sqlite3_wal_hook callback, the

  50628. ** number of frames in the WAL at the point of the last commit since

  50629. ** sqlite3WalCallback() was called.  If no commits have occurred since

  50630. ** the last call, then return 0.

  50631. */

  50632. SQLITE_PRIVATE int sqlite3WalCallback(Wal *pWal);

  50633. 

  50634. /* Tell the wal layer that an EXCLUSIVE lock has been obtained (or released)

  50635. ** by the pager layer on the database file.

  50636. */

  50637. SQLITE_PRIVATE int sqlite3WalExclusiveMode(Wal *pWal, int op);

  50638. 

  50639. /* Return true if the argument is non-NULL and the WAL module is using

  50640. ** heap-memory for the wal-index. Otherwise, if the argument is NULL or the

  50641. ** WAL module is using shared-memory, return false. 

  50642. */

  50643. SQLITE_PRIVATE int sqlite3WalHeapMemory(Wal *pWal);

  50644. 

  50645. #ifdef SQLITE_ENABLE_SNAPSHOT

  50646. SQLITE_PRIVATE int sqlite3WalSnapshotGet(Wal *pWal, sqlite3_snapshot **ppSnapshot);

  50647. SQLITE_PRIVATE void sqlite3WalSnapshotOpen(Wal *pWal, sqlite3_snapshot *pSnapshot);

  50648. SQLITE_PRIVATE int sqlite3WalSnapshotRecover(Wal *pWal);

  50649. SQLITE_PRIVATE int sqlite3WalSnapshotCheck(Wal *pWal, sqlite3_snapshot *pSnapshot);

  50650. SQLITE_PRIVATE void sqlite3WalSnapshotUnlock(Wal *pWal);

  50651. #endif

  50652. 

  50653. #ifdef SQLITE_ENABLE_ZIPVFS

  50654. /* If the WAL file is not empty, return the number of bytes of content

  50655. ** stored in each frame (i.e. the db page-size when the WAL was created).

  50656. */

  50657. SQLITE_PRIVATE int sqlite3WalFramesize(Wal *pWal);

  50658. #endif

  50659. 

  50660. /* Return the sqlite3_file object for the WAL file */

  50661. SQLITE_PRIVATE sqlite3_file *sqlite3WalFile(Wal *pWal);

  50662. 

  50663. #endif /* ifndef SQLITE_OMIT_WAL */

  50664. #endif /* SQLITE_WAL_H */

  50665. 

  50666. /************** End of wal.h *************************************************/

  50667. /************** Continuing where we left off in pager.c **********************/

  50668. 

  50669. 

  50670. /******************* NOTES ON THE DESIGN OF THE PAGER ************************

  50671. **

  50672. ** This comment block describes invariants that hold when using a rollback

  50673. ** journal.  These invariants do not apply for journal_mode=WAL,

  50674. ** journal_mode=MEMORY, or journal_mode=OFF.

  50675. **

  50676. ** Within this comment block, a page is deemed to have been synced

  50677. ** automatically as soon as it is written when PRAGMA synchronous=OFF.

  50678. ** Otherwise, the page is not synced until the xSync method of the VFS

  50679. ** is called successfully on the file containing the page.

  50680. **

  50681. ** Definition:  A page of the database file is said to be "overwriteable" if

  50682. ** one or more of the following are true about the page:

  50683. ** 

  50684. **     (a)  The original content of the page as it was at the beginning of

  50685. **          the transaction has been written into the rollback journal and

  50686. **          synced.

  50687. ** 

  50688. **     (b)  The page was a freelist leaf page at the start of the transaction.

  50689. ** 

  50690. **     (c)  The page number is greater than the largest page that existed in

  50691. **          the database file at the start of the transaction.

  50692. ** 

  50693. ** (1) A page of the database file is never overwritten unless one of the

  50694. **     following are true:

  50695. ** 

  50696. **     (a) The page and all other pages on the same sector are overwriteable.

  50697. ** 

  50698. **     (b) The atomic page write optimization is enabled, and the entire

  50699. **         transaction other than the update of the transaction sequence

  50700. **         number consists of a single page change.

  50701. ** 

  50702. ** (2) The content of a page written into the rollback journal exactly matches

  50703. **     both the content in the database when the rollback journal was written

  50704. **     and the content in the database at the beginning of the current

  50705. **     transaction.

  50706. ** 

  50707. ** (3) Writes to the database file are an integer multiple of the page size

  50708. **     in length and are aligned on a page boundary.

  50709. ** 

  50710. ** (4) Reads from the database file are either aligned on a page boundary and

  50711. **     an integer multiple of the page size in length or are taken from the

  50712. **     first 100 bytes of the database file.

  50713. ** 

  50714. ** (5) All writes to the database file are synced prior to the rollback journal

  50715. **     being deleted, truncated, or zeroed.

  50716. ** 

  50717. ** (6) If a master journal file is used, then all writes to the database file

  50718. **     are synced prior to the master journal being deleted.

  50719. ** 

  50720. ** Definition: Two databases (or the same database at two points it time)

  50721. ** are said to be "logically equivalent" if they give the same answer to

  50722. ** all queries.  Note in particular the content of freelist leaf

  50723. ** pages can be changed arbitrarily without affecting the logical equivalence

  50724. ** of the database.

  50725. ** 

  50726. ** (7) At any time, if any subset, including the empty set and the total set,

  50727. **     of the unsynced changes to a rollback journal are removed and the 

  50728. **     journal is rolled back, the resulting database file will be logically

  50729. **     equivalent to the database file at the beginning of the transaction.

  50730. ** 

  50731. ** (8) When a transaction is rolled back, the xTruncate method of the VFS

  50732. **     is called to restore the database file to the same size it was at

  50733. **     the beginning of the transaction.  (In some VFSes, the xTruncate

  50734. **     method is a no-op, but that does not change the fact the SQLite will

  50735. **     invoke it.)

  50736. ** 

  50737. ** (9) Whenever the database file is modified, at least one bit in the range

  50738. **     of bytes from 24 through 39 inclusive will be changed prior to releasing

  50739. **     the EXCLUSIVE lock, thus signaling other connections on the same

  50740. **     database to flush their caches.

  50741. **

  50742. ** (10) The pattern of bits in bytes 24 through 39 shall not repeat in less

  50743. **      than one billion transactions.

  50744. **

  50745. ** (11) A database file is well-formed at the beginning and at the conclusion

  50746. **      of every transaction.

  50747. **

  50748. ** (12) An EXCLUSIVE lock is held on the database file when writing to

  50749. **      the database file.

  50750. **

  50751. ** (13) A SHARED lock is held on the database file while reading any

  50752. **      content out of the database file.

  50753. **

  50754. ******************************************************************************/

  50755. 

  50756. /*

  50757. ** Macros for troubleshooting.  Normally turned off

  50758. */

  50759. #if 0

  50760. int sqlite3PagerTrace=1;  /* True to enable tracing */

  50761. #define sqlite3DebugPrintf printf

  50762. #define PAGERTRACE(X)     if( sqlite3PagerTrace ){ sqlite3DebugPrintf X; }

  50763. #else

  50764. #define PAGERTRACE(X)

  50765. #endif

  50766. 

  50767. /*

  50768. ** The following two macros are used within the PAGERTRACE() macros above

  50769. ** to print out file-descriptors. 

  50770. **

  50771. ** PAGERID() takes a pointer to a Pager struct as its argument. The

  50772. ** associated file-descriptor is returned. FILEHANDLEID() takes an sqlite3_file

  50773. ** struct as its argument.

  50774. */

  50775. #define PAGERID(p) (SQLITE_PTR_TO_INT(p->fd))

  50776. #define FILEHANDLEID(fd) (SQLITE_PTR_TO_INT(fd))

  50777. 

  50778. /*

  50779. ** The Pager.eState variable stores the current 'state' of a pager. A

  50780. ** pager may be in any one of the seven states shown in the following

  50781. ** state diagram.

  50782. **

  50783. **                            OPEN <------+------+

  50784. **                              |         |      |

  50785. **                              V         |      |

  50786. **               +---------> READER-------+      |

  50787. **               |              |                |

  50788. **               |              V                |

  50789. **               |<-------WRITER_LOCKED------> ERROR

  50790. **               |              |                ^  

  50791. **               |              V                |

  50792. **               |<------WRITER_CACHEMOD-------->|

  50793. **               |              |                |

  50794. **               |              V                |

  50795. **               |<-------WRITER_DBMOD---------->|

  50796. **               |              |                |

  50797. **               |              V                |

  50798. **               +<------WRITER_FINISHED-------->+

  50799. **

  50800. **

  50801. ** List of state transitions and the C [function] that performs each:

  50802. ** 

  50803. **   OPEN              -> READER              [sqlite3PagerSharedLock]

  50804. **   READER            -> OPEN                [pager_unlock]

  50805. **

  50806. **   READER            -> WRITER_LOCKED       [sqlite3PagerBegin]

  50807. **   WRITER_LOCKED     -> WRITER_CACHEMOD     [pager_open_journal]

  50808. **   WRITER_CACHEMOD   -> WRITER_DBMOD        [syncJournal]

  50809. **   WRITER_DBMOD      -> WRITER_FINISHED     [sqlite3PagerCommitPhaseOne]

  50810. **   WRITER_***        -> READER              [pager_end_transaction]

  50811. **

  50812. **   WRITER_***        -> ERROR               [pager_error]

  50813. **   ERROR             -> OPEN                [pager_unlock]

  50814. ** 

  50815. **

  50816. **  OPEN:

  50817. **

  50818. **    The pager starts up in this state. Nothing is guaranteed in this

  50819. **    state - the file may or may not be locked and the database size is

  50820. **    unknown. The database may not be read or written.

  50821. **

  50822. **    * No read or write transaction is active.

  50823. **    * Any lock, or no lock at all, may be held on the database file.

  50824. **    * The dbSize, dbOrigSize and dbFileSize variables may not be trusted.

  50825. **

  50826. **  READER:

  50827. **

  50828. **    In this state all the requirements for reading the database in 

  50829. **    rollback (non-WAL) mode are met. Unless the pager is (or recently

  50830. **    was) in exclusive-locking mode, a user-level read transaction is 

  50831. **    open. The database size is known in this state.

  50832. **

  50833. **    A connection running with locking_mode=normal enters this state when

  50834. **    it opens a read-transaction on the database and returns to state

  50835. **    OPEN after the read-transaction is completed. However a connection

  50836. **    running in locking_mode=exclusive (including temp databases) remains in

  50837. **    this state even after the read-transaction is closed. The only way

  50838. **    a locking_mode=exclusive connection can transition from READER to OPEN

  50839. **    is via the ERROR state (see below).

  50840. ** 

  50841. **    * A read transaction may be active (but a write-transaction cannot).

  50842. **    * A SHARED or greater lock is held on the database file.

  50843. **    * The dbSize variable may be trusted (even if a user-level read 

  50844. **      transaction is not active). The dbOrigSize and dbFileSize variables

  50845. **      may not be trusted at this point.

  50846. **    * If the database is a WAL database, then the WAL connection is open.

  50847. **    * Even if a read-transaction is not open, it is guaranteed that 

  50848. **      there is no hot-journal in the file-system.

  50849. **

  50850. **  WRITER_LOCKED:

  50851. **

  50852. **    The pager moves to this state from READER when a write-transaction

  50853. **    is first opened on the database. In WRITER_LOCKED state, all locks 

  50854. **    required to start a write-transaction are held, but no actual 

  50855. **    modifications to the cache or database have taken place.

  50856. **

  50857. **    In rollback mode, a RESERVED or (if the transaction was opened with 

  50858. **    BEGIN EXCLUSIVE) EXCLUSIVE lock is obtained on the database file when

  50859. **    moving to this state, but the journal file is not written to or opened 

  50860. **    to in this state. If the transaction is committed or rolled back while 

  50861. **    in WRITER_LOCKED state, all that is required is to unlock the database 

  50862. **    file.

  50863. **

  50864. **    IN WAL mode, WalBeginWriteTransaction() is called to lock the log file.

  50865. **    If the connection is running with locking_mode=exclusive, an attempt

  50866. **    is made to obtain an EXCLUSIVE lock on the database file.

  50867. **

  50868. **    * A write transaction is active.

  50869. **    * If the connection is open in rollback-mode, a RESERVED or greater 

  50870. **      lock is held on the database file.

  50871. **    * If the connection is open in WAL-mode, a WAL write transaction

  50872. **      is open (i.e. sqlite3WalBeginWriteTransaction() has been successfully

  50873. **      called).

  50874. **    * The dbSize, dbOrigSize and dbFileSize variables are all valid.

  50875. **    * The contents of the pager cache have not been modified.

  50876. **    * The journal file may or may not be open.

  50877. **    * Nothing (not even the first header) has been written to the journal.

  50878. **

  50879. **  WRITER_CACHEMOD:

  50880. **

  50881. **    A pager moves from WRITER_LOCKED state to this state when a page is

  50882. **    first modified by the upper layer. In rollback mode the journal file

  50883. **    is opened (if it is not already open) and a header written to the

  50884. **    start of it. The database file on disk has not been modified.

  50885. **

  50886. **    * A write transaction is active.

  50887. **    * A RESERVED or greater lock is held on the database file.

  50888. **    * The journal file is open and the first header has been written 

  50889. **      to it, but the header has not been synced to disk.

  50890. **    * The contents of the page cache have been modified.

  50891. **

  50892. **  WRITER_DBMOD:

  50893. **

  50894. **    The pager transitions from WRITER_CACHEMOD into WRITER_DBMOD state

  50895. **    when it modifies the contents of the database file. WAL connections

  50896. **    never enter this state (since they do not modify the database file,

  50897. **    just the log file).

  50898. **

  50899. **    * A write transaction is active.

  50900. **    * An EXCLUSIVE or greater lock is held on the database file.

  50901. **    * The journal file is open and the first header has been written 

  50902. **      and synced to disk.

  50903. **    * The contents of the page cache have been modified (and possibly

  50904. **      written to disk).

  50905. **

  50906. **  WRITER_FINISHED:

  50907. **

  50908. **    It is not possible for a WAL connection to enter this state.

  50909. **

  50910. **    A rollback-mode pager changes to WRITER_FINISHED state from WRITER_DBMOD

  50911. **    state after the entire transaction has been successfully written into the

  50912. **    database file. In this state the transaction may be committed simply

  50913. **    by finalizing the journal file. Once in WRITER_FINISHED state, it is 

  50914. **    not possible to modify the database further. At this point, the upper 

  50915. **    layer must either commit or rollback the transaction.

  50916. **

  50917. **    * A write transaction is active.

  50918. **    * An EXCLUSIVE or greater lock is held on the database file.

  50919. **    * All writing and syncing of journal and database data has finished.

  50920. **      If no error occurred, all that remains is to finalize the journal to

  50921. **      commit the transaction. If an error did occur, the caller will need

  50922. **      to rollback the transaction. 

  50923. **

  50924. **  ERROR:

  50925. **

  50926. **    The ERROR state is entered when an IO or disk-full error (including

  50927. **    SQLITE_IOERR_NOMEM) occurs at a point in the code that makes it 

  50928. **    difficult to be sure that the in-memory pager state (cache contents, 

  50929. **    db size etc.) are consistent with the contents of the file-system.

  50930. **

  50931. **    Temporary pager files may enter the ERROR state, but in-memory pagers

  50932. **    cannot.

  50933. **

  50934. **    For example, if an IO error occurs while performing a rollback, 

  50935. **    the contents of the page-cache may be left in an inconsistent state.

  50936. **    At this point it would be dangerous to change back to READER state

  50937. **    (as usually happens after a rollback). Any subsequent readers might

  50938. **    report database corruption (due to the inconsistent cache), and if

  50939. **    they upgrade to writers, they may inadvertently corrupt the database

  50940. **    file. To avoid this hazard, the pager switches into the ERROR state

  50941. **    instead of READER following such an error.

  50942. **

  50943. **    Once it has entered the ERROR state, any attempt to use the pager

  50944. **    to read or write data returns an error. Eventually, once all 

  50945. **    outstanding transactions have been abandoned, the pager is able to

  50946. **    transition back to OPEN state, discarding the contents of the 

  50947. **    page-cache and any other in-memory state at the same time. Everything

  50948. **    is reloaded from disk (and, if necessary, hot-journal rollback peformed)

  50949. **    when a read-transaction is next opened on the pager (transitioning

  50950. **    the pager into READER state). At that point the system has recovered 

  50951. **    from the error.

  50952. **

  50953. **    Specifically, the pager jumps into the ERROR state if:

  50954. **

  50955. **      1. An error occurs while attempting a rollback. This happens in

  50956. **         function sqlite3PagerRollback().

  50957. **

  50958. **      2. An error occurs while attempting to finalize a journal file

  50959. **         following a commit in function sqlite3PagerCommitPhaseTwo().

  50960. **

  50961. **      3. An error occurs while attempting to write to the journal or

  50962. **         database file in function pagerStress() in order to free up

  50963. **         memory.

  50964. **

  50965. **    In other cases, the error is returned to the b-tree layer. The b-tree

  50966. **    layer then attempts a rollback operation. If the error condition 

  50967. **    persists, the pager enters the ERROR state via condition (1) above.

  50968. **

  50969. **    Condition (3) is necessary because it can be triggered by a read-only

  50970. **    statement executed within a transaction. In this case, if the error

  50971. **    code were simply returned to the user, the b-tree layer would not

  50972. **    automatically attempt a rollback, as it assumes that an error in a

  50973. **    read-only statement cannot leave the pager in an internally inconsistent 

  50974. **    state.

  50975. **

  50976. **    * The Pager.errCode variable is set to something other than SQLITE_OK.

  50977. **    * There are one or more outstanding references to pages (after the

  50978. **      last reference is dropped the pager should move back to OPEN state).

  50979. **    * The pager is not an in-memory pager.

  50980. **    

  50981. **

  50982. ** Notes:

  50983. **

  50984. **   * A pager is never in WRITER_DBMOD or WRITER_FINISHED state if the

  50985. **     connection is open in WAL mode. A WAL connection is always in one

  50986. **     of the first four states.

  50987. **

  50988. **   * Normally, a connection open in exclusive mode is never in PAGER_OPEN

  50989. **     state. There are two exceptions: immediately after exclusive-mode has

  50990. **     been turned on (and before any read or write transactions are 

  50991. **     executed), and when the pager is leaving the "error state".

  50992. **

  50993. **   * See also: assert_pager_state().

  50994. */

  50995. #define PAGER_OPEN                  0

  50996. #define PAGER_READER                1

  50997. #define PAGER_WRITER_LOCKED         2

  50998. #define PAGER_WRITER_CACHEMOD       3

  50999. #define PAGER_WRITER_DBMOD          4

  51000. #define PAGER_WRITER_FINISHED       5

  51001. #define PAGER_ERROR                 6

  51002. 

  51003. /*

  51004. ** The Pager.eLock variable is almost always set to one of the 

  51005. ** following locking-states, according to the lock currently held on

  51006. ** the database file: NO_LOCK, SHARED_LOCK, RESERVED_LOCK or EXCLUSIVE_LOCK.

  51007. ** This variable is kept up to date as locks are taken and released by

  51008. ** the pagerLockDb() and pagerUnlockDb() wrappers.

  51009. **

  51010. ** If the VFS xLock() or xUnlock() returns an error other than SQLITE_BUSY

  51011. ** (i.e. one of the SQLITE_IOERR subtypes), it is not clear whether or not

  51012. ** the operation was successful. In these circumstances pagerLockDb() and

  51013. ** pagerUnlockDb() take a conservative approach - eLock is always updated

  51014. ** when unlocking the file, and only updated when locking the file if the

  51015. ** VFS call is successful. This way, the Pager.eLock variable may be set

  51016. ** to a less exclusive (lower) value than the lock that is actually held

  51017. ** at the system level, but it is never set to a more exclusive value.

  51018. **

  51019. ** This is usually safe. If an xUnlock fails or appears to fail, there may 

  51020. ** be a few redundant xLock() calls or a lock may be held for longer than

  51021. ** required, but nothing really goes wrong.

  51022. **

  51023. ** The exception is when the database file is unlocked as the pager moves

  51024. ** from ERROR to OPEN state. At this point there may be a hot-journal file 

  51025. ** in the file-system that needs to be rolled back (as part of an OPEN->SHARED

  51026. ** transition, by the same pager or any other). If the call to xUnlock()

  51027. ** fails at this point and the pager is left holding an EXCLUSIVE lock, this

  51028. ** can confuse the call to xCheckReservedLock() call made later as part

  51029. ** of hot-journal detection.

  51030. **

  51031. ** xCheckReservedLock() is defined as returning true "if there is a RESERVED 

  51032. ** lock held by this process or any others". So xCheckReservedLock may 

  51033. ** return true because the caller itself is holding an EXCLUSIVE lock (but

  51034. ** doesn't know it because of a previous error in xUnlock). If this happens

  51035. ** a hot-journal may be mistaken for a journal being created by an active

  51036. ** transaction in another process, causing SQLite to read from the database

  51037. ** without rolling it back.

  51038. **

  51039. ** To work around this, if a call to xUnlock() fails when unlocking the

  51040. ** database in the ERROR state, Pager.eLock is set to UNKNOWN_LOCK. It

  51041. ** is only changed back to a real locking state after a successful call

  51042. ** to xLock(EXCLUSIVE). Also, the code to do the OPEN->SHARED state transition

  51043. ** omits the check for a hot-journal if Pager.eLock is set to UNKNOWN_LOCK 

  51044. ** lock. Instead, it assumes a hot-journal exists and obtains an EXCLUSIVE

  51045. ** lock on the database file before attempting to roll it back. See function

  51046. ** PagerSharedLock() for more detail.

  51047. **

  51048. ** Pager.eLock may only be set to UNKNOWN_LOCK when the pager is in 

  51049. ** PAGER_OPEN state.

  51050. */

  51051. #define UNKNOWN_LOCK                (EXCLUSIVE_LOCK+1)

  51052. 

  51053. /*

  51054. ** A macro used for invoking the codec if there is one

  51055. */

  51056. #ifdef SQLITE_HAS_CODEC

  51057. # define CODEC1(P,D,N,X,E) \

  51058.     if( P->xCodec && P->xCodec(P->pCodec,D,N,X)==0 ){ E; }

  51059. # define CODEC2(P,D,N,X,E,O) \

  51060.     if( P->xCodec==0 ){ O=(char*)D; }else \

  51061.     if( (O=(char*)(P->xCodec(P->pCodec,D,N,X)))==0 ){ E; }

  51062. #else

  51063. # define CODEC1(P,D,N,X,E)   /* NO-OP */

  51064. # define CODEC2(P,D,N,X,E,O) O=(char*)D

  51065. #endif

  51066. 

  51067. /*

  51068. ** The maximum allowed sector size. 64KiB. If the xSectorsize() method 

  51069. ** returns a value larger than this, then MAX_SECTOR_SIZE is used instead.

  51070. ** This could conceivably cause corruption following a power failure on

  51071. ** such a system. This is currently an undocumented limit.

  51072. */

  51073. #define MAX_SECTOR_SIZE 0x10000

  51074. 

  51075. 

  51076. /*

  51077. ** An instance of the following structure is allocated for each active

  51078. ** savepoint and statement transaction in the system. All such structures

  51079. ** are stored in the Pager.aSavepoint[] array, which is allocated and

  51080. ** resized using sqlite3Realloc().

  51081. **

  51082. ** When a savepoint is created, the PagerSavepoint.iHdrOffset field is

  51083. ** set to 0. If a journal-header is written into the main journal while

  51084. ** the savepoint is active, then iHdrOffset is set to the byte offset 

  51085. ** immediately following the last journal record written into the main

  51086. ** journal before the journal-header. This is required during savepoint

  51087. ** rollback (see pagerPlaybackSavepoint()).

  51088. */

  51089. typedef struct PagerSavepoint PagerSavepoint;

  51090. struct PagerSavepoint {

  51091.   i64 iOffset;                 /* Starting offset in main journal */

  51092.   i64 iHdrOffset;              /* See above */

  51093.   Bitvec *pInSavepoint;        /* Set of pages in this savepoint */

  51094.   Pgno nOrig;                  /* Original number of pages in file */

  51095.   Pgno iSubRec;                /* Index of first record in sub-journal */

  51096. #ifndef SQLITE_OMIT_WAL

  51097.   u32 aWalData[WAL_SAVEPOINT_NDATA];        /* WAL savepoint context */

  51098. #endif

  51099. };

  51100. 

  51101. /*

  51102. ** Bits of the Pager.doNotSpill flag.  See further description below.

  51103. */

  51104. #define SPILLFLAG_OFF         0x01 /* Never spill cache.  Set via pragma */

  51105. #define SPILLFLAG_ROLLBACK    0x02 /* Current rolling back, so do not spill */

  51106. #define SPILLFLAG_NOSYNC      0x04 /* Spill is ok, but do not sync */

  51107. 

  51108. /*

  51109. ** An open page cache is an instance of struct Pager. A description of

  51110. ** some of the more important member variables follows:

  51111. **

  51112. ** eState

  51113. **

  51114. **   The current 'state' of the pager object. See the comment and state

  51115. **   diagram above for a description of the pager state.

  51116. **

  51117. ** eLock

  51118. **

  51119. **   For a real on-disk database, the current lock held on the database file -

  51120. **   NO_LOCK, SHARED_LOCK, RESERVED_LOCK or EXCLUSIVE_LOCK.

  51121. **

  51122. **   For a temporary or in-memory database (neither of which require any

  51123. **   locks), this variable is always set to EXCLUSIVE_LOCK. Since such

  51124. **   databases always have Pager.exclusiveMode==1, this tricks the pager

  51125. **   logic into thinking that it already has all the locks it will ever

  51126. **   need (and no reason to release them).

  51127. **

  51128. **   In some (obscure) circumstances, this variable may also be set to

  51129. **   UNKNOWN_LOCK. See the comment above the #define of UNKNOWN_LOCK for

  51130. **   details.

  51131. **

  51132. ** changeCountDone

  51133. **

  51134. **   This boolean variable is used to make sure that the change-counter 

  51135. **   (the 4-byte header field at byte offset 24 of the database file) is 

  51136. **   not updated more often than necessary. 

  51137. **

  51138. **   It is set to true when the change-counter field is updated, which 

  51139. **   can only happen if an exclusive lock is held on the database file.

  51140. **   It is cleared (set to false) whenever an exclusive lock is 

  51141. **   relinquished on the database file. Each time a transaction is committed,

  51142. **   The changeCountDone flag is inspected. If it is true, the work of

  51143. **   updating the change-counter is omitted for the current transaction.

  51144. **

  51145. **   This mechanism means that when running in exclusive mode, a connection 

  51146. **   need only update the change-counter once, for the first transaction

  51147. **   committed.

  51148. **

  51149. ** setMaster

  51150. **

  51151. **   When PagerCommitPhaseOne() is called to commit a transaction, it may

  51152. **   (or may not) specify a master-journal name to be written into the 

  51153. **   journal file before it is synced to disk.

  51154. **

  51155. **   Whether or not a journal file contains a master-journal pointer affects 

  51156. **   the way in which the journal file is finalized after the transaction is 

  51157. **   committed or rolled back when running in "journal_mode=PERSIST" mode.

  51158. **   If a journal file does not contain a master-journal pointer, it is

  51159. **   finalized by overwriting the first journal header with zeroes. If

  51160. **   it does contain a master-journal pointer the journal file is finalized 

  51161. **   by truncating it to zero bytes, just as if the connection were 

  51162. **   running in "journal_mode=truncate" mode.

  51163. **

  51164. **   Journal files that contain master journal pointers cannot be finalized

  51165. **   simply by overwriting the first journal-header with zeroes, as the

  51166. **   master journal pointer could interfere with hot-journal rollback of any

  51167. **   subsequently interrupted transaction that reuses the journal file.

  51168. **

  51169. **   The flag is cleared as soon as the journal file is finalized (either

  51170. **   by PagerCommitPhaseTwo or PagerRollback). If an IO error prevents the

  51171. **   journal file from being successfully finalized, the setMaster flag

  51172. **   is cleared anyway (and the pager will move to ERROR state).

  51173. **

  51174. ** doNotSpill

  51175. **

  51176. **   This variables control the behavior of cache-spills  (calls made by

  51177. **   the pcache module to the pagerStress() routine to write cached data

  51178. **   to the file-system in order to free up memory).

  51179. **

  51180. **   When bits SPILLFLAG_OFF or SPILLFLAG_ROLLBACK of doNotSpill are set,

  51181. **   writing to the database from pagerStress() is disabled altogether.

  51182. **   The SPILLFLAG_ROLLBACK case is done in a very obscure case that

  51183. **   comes up during savepoint rollback that requires the pcache module

  51184. **   to allocate a new page to prevent the journal file from being written

  51185. **   while it is being traversed by code in pager_playback().  The SPILLFLAG_OFF

  51186. **   case is a user preference.

  51187. ** 

  51188. **   If the SPILLFLAG_NOSYNC bit is set, writing to the database from

  51189. **   pagerStress() is permitted, but syncing the journal file is not.

  51190. **   This flag is set by sqlite3PagerWrite() when the file-system sector-size

  51191. **   is larger than the database page-size in order to prevent a journal sync

  51192. **   from happening in between the journalling of two pages on the same sector. 

  51193. **

  51194. ** subjInMemory

  51195. **

  51196. **   This is a boolean variable. If true, then any required sub-journal

  51197. **   is opened as an in-memory journal file. If false, then in-memory

  51198. **   sub-journals are only used for in-memory pager files.

  51199. **

  51200. **   This variable is updated by the upper layer each time a new 

  51201. **   write-transaction is opened.

  51202. **

  51203. ** dbSize, dbOrigSize, dbFileSize

  51204. **

  51205. **   Variable dbSize is set to the number of pages in the database file.

  51206. **   It is valid in PAGER_READER and higher states (all states except for

  51207. **   OPEN and ERROR). 

  51208. **

  51209. **   dbSize is set based on the size of the database file, which may be 

  51210. **   larger than the size of the database (the value stored at offset

  51211. **   28 of the database header by the btree). If the size of the file

  51212. **   is not an integer multiple of the page-size, the value stored in

  51213. **   dbSize is rounded down (i.e. a 5KB file with 2K page-size has dbSize==2).

  51214. **   Except, any file that is greater than 0 bytes in size is considered

  51215. **   to have at least one page. (i.e. a 1KB file with 2K page-size leads

  51216. **   to dbSize==1).

  51217. **

  51218. **   During a write-transaction, if pages with page-numbers greater than

  51219. **   dbSize are modified in the cache, dbSize is updated accordingly.

  51220. **   Similarly, if the database is truncated using PagerTruncateImage(), 

  51221. **   dbSize is updated.

  51222. **

  51223. **   Variables dbOrigSize and dbFileSize are valid in states 

  51224. **   PAGER_WRITER_LOCKED and higher. dbOrigSize is a copy of the dbSize

  51225. **   variable at the start of the transaction. It is used during rollback,

  51226. **   and to determine whether or not pages need to be journalled before

  51227. **   being modified.

  51228. **

  51229. **   Throughout a write-transaction, dbFileSize contains the size of

  51230. **   the file on disk in pages. It is set to a copy of dbSize when the

  51231. **   write-transaction is first opened, and updated when VFS calls are made

  51232. **   to write or truncate the database file on disk. 

  51233. **

  51234. **   The only reason the dbFileSize variable is required is to suppress 

  51235. **   unnecessary calls to xTruncate() after committing a transaction. If, 

  51236. **   when a transaction is committed, the dbFileSize variable indicates 

  51237. **   that the database file is larger than the database image (Pager.dbSize), 

  51238. **   pager_truncate() is called. The pager_truncate() call uses xFilesize()

  51239. **   to measure the database file on disk, and then truncates it if required.

  51240. **   dbFileSize is not used when rolling back a transaction. In this case

  51241. **   pager_truncate() is called unconditionally (which means there may be

  51242. **   a call to xFilesize() that is not strictly required). In either case,

  51243. **   pager_truncate() may cause the file to become smaller or larger.

  51244. **

  51245. ** dbHintSize

  51246. **

  51247. **   The dbHintSize variable is used to limit the number of calls made to

  51248. **   the VFS xFileControl(FCNTL_SIZE_HINT) method. 

  51249. **

  51250. **   dbHintSize is set to a copy of the dbSize variable when a

  51251. **   write-transaction is opened (at the same time as dbFileSize and

  51252. **   dbOrigSize). If the xFileControl(FCNTL_SIZE_HINT) method is called,

  51253. **   dbHintSize is increased to the number of pages that correspond to the

  51254. **   size-hint passed to the method call. See pager_write_pagelist() for 

  51255. **   details.

  51256. **

  51257. ** errCode

  51258. **

  51259. **   The Pager.errCode variable is only ever used in PAGER_ERROR state. It

  51260. **   is set to zero in all other states. In PAGER_ERROR state, Pager.errCode 

  51261. **   is always set to SQLITE_FULL, SQLITE_IOERR or one of the SQLITE_IOERR_XXX 

  51262. **   sub-codes.

  51263. **

  51264. ** syncFlags, walSyncFlags

  51265. **

  51266. **   syncFlags is either SQLITE_SYNC_NORMAL (0x02) or SQLITE_SYNC_FULL (0x03).

  51267. **   syncFlags is used for rollback mode.  walSyncFlags is used for WAL mode

  51268. **   and contains the flags used to sync the checkpoint operations in the

  51269. **   lower two bits, and sync flags used for transaction commits in the WAL

  51270. **   file in bits 0x04 and 0x08.  In other words, to get the correct sync flags

  51271. **   for checkpoint operations, use (walSyncFlags&0x03) and to get the correct

  51272. **   sync flags for transaction commit, use ((walSyncFlags>>2)&0x03).  Note

  51273. **   that with synchronous=NORMAL in WAL mode, transaction commit is not synced

  51274. **   meaning that the 0x04 and 0x08 bits are both zero.

  51275. */

  51276. struct Pager {

  51277.   sqlite3_vfs *pVfs;          /* OS functions to use for IO */

  51278.   u8 exclusiveMode;           /* Boolean. True if locking_mode==EXCLUSIVE */

  51279.   u8 journalMode;             /* One of the PAGER_JOURNALMODE_* values */

  51280.   u8 useJournal;              /* Use a rollback journal on this file */

  51281.   u8 noSync;                  /* Do not sync the journal if true */

  51282.   u8 fullSync;                /* Do extra syncs of the journal for robustness */

  51283.   u8 extraSync;               /* sync directory after journal delete */

  51284.   u8 syncFlags;               /* SYNC_NORMAL or SYNC_FULL otherwise */

  51285.   u8 walSyncFlags;            /* See description above */

  51286.   u8 tempFile;                /* zFilename is a temporary or immutable file */

  51287.   u8 noLock;                  /* Do not lock (except in WAL mode) */

  51288.   u8 readOnly;                /* True for a read-only database */

  51289.   u8 memDb;                   /* True to inhibit all file I/O */

  51290. 

  51291.   /**************************************************************************

  51292.   ** The following block contains those class members that change during

  51293.   ** routine operation.  Class members not in this block are either fixed

  51294.   ** when the pager is first created or else only change when there is a

  51295.   ** significant mode change (such as changing the page_size, locking_mode,

  51296.   ** or the journal_mode).  From another view, these class members describe

  51297.   ** the "state" of the pager, while other class members describe the

  51298.   ** "configuration" of the pager.

  51299.   */

  51300.   u8 eState;                  /* Pager state (OPEN, READER, WRITER_LOCKED..) */

  51301.   u8 eLock;                   /* Current lock held on database file */

  51302.   u8 changeCountDone;         /* Set after incrementing the change-counter */

  51303.   u8 setMaster;               /* True if a m-j name has been written to jrnl */

  51304.   u8 doNotSpill;              /* Do not spill the cache when non-zero */

  51305.   u8 subjInMemory;            /* True to use in-memory sub-journals */

  51306.   u8 bUseFetch;               /* True to use xFetch() */

  51307.   u8 hasHeldSharedLock;       /* True if a shared lock has ever been held */

  51308.   Pgno dbSize;                /* Number of pages in the database */

  51309.   Pgno dbOrigSize;            /* dbSize before the current transaction */

  51310.   Pgno dbFileSize;            /* Number of pages in the database file */

  51311.   Pgno dbHintSize;            /* Value passed to FCNTL_SIZE_HINT call */

  51312.   int errCode;                /* One of several kinds of errors */

  51313.   int nRec;                   /* Pages journalled since last j-header written */

  51314.   u32 cksumInit;              /* Quasi-random value added to every checksum */

  51315.   u32 nSubRec;                /* Number of records written to sub-journal */

  51316.   Bitvec *pInJournal;         /* One bit for each page in the database file */

  51317.   sqlite3_file *fd;           /* File descriptor for database */

  51318.   sqlite3_file *jfd;          /* File descriptor for main journal */

  51319.   sqlite3_file *sjfd;         /* File descriptor for sub-journal */

  51320.   i64 journalOff;             /* Current write offset in the journal file */

  51321.   i64 journalHdr;             /* Byte offset to previous journal header */

  51322.   sqlite3_backup *pBackup;    /* Pointer to list of ongoing backup processes */

  51323.   PagerSavepoint *aSavepoint; /* Array of active savepoints */

  51324.   int nSavepoint;             /* Number of elements in aSavepoint[] */

  51325.   u32 iDataVersion;           /* Changes whenever database content changes */

  51326.   char dbFileVers[16];        /* Changes whenever database file changes */

  51327. 

  51328.   int nMmapOut;               /* Number of mmap pages currently outstanding */

  51329.   sqlite3_int64 szMmap;       /* Desired maximum mmap size */

  51330.   PgHdr *pMmapFreelist;       /* List of free mmap page headers (pDirty) */

  51331.   /*

  51332.   ** End of the routinely-changing class members

  51333.   ***************************************************************************/

  51334. 

  51335.   u16 nExtra;                 /* Add this many bytes to each in-memory page */

  51336.   i16 nReserve;               /* Number of unused bytes at end of each page */

  51337.   u32 vfsFlags;               /* Flags for sqlite3_vfs.xOpen() */

  51338.   u32 sectorSize;             /* Assumed sector size during rollback */

  51339.   int pageSize;               /* Number of bytes in a page */

  51340.   Pgno mxPgno;                /* Maximum allowed size of the database */

  51341.   i64 journalSizeLimit;       /* Size limit for persistent journal files */

  51342.   char *zFilename;            /* Name of the database file */

  51343.   char *zJournal;             /* Name of the journal file */

  51344.   int (*xBusyHandler)(void*); /* Function to call when busy */

  51345.   void *pBusyHandlerArg;      /* Context argument for xBusyHandler */

  51346.   int aStat[4];               /* Total cache hits, misses, writes, spills */

  51347. #ifdef SQLITE_TEST

  51348.   int nRead;                  /* Database pages read */

  51349. #endif

  51350.   void (*xReiniter)(DbPage*); /* Call this routine when reloading pages */

  51351.   int (*xGet)(Pager*,Pgno,DbPage**,int); /* Routine to fetch a patch */

  51352. #ifdef SQLITE_HAS_CODEC

  51353.   void *(*xCodec)(void*,void*,Pgno,int); /* Routine for en/decoding data */

  51354.   void (*xCodecSizeChng)(void*,int,int); /* Notify of page size changes */

  51355.   void (*xCodecFree)(void*);             /* Destructor for the codec */

  51356.   void *pCodec;               /* First argument to xCodec... methods */

  51357. #endif

  51358.   char *pTmpSpace;            /* Pager.pageSize bytes of space for tmp use */

  51359.   PCache *pPCache;            /* Pointer to page cache object */

  51360. #ifndef SQLITE_OMIT_WAL

  51361.   Wal *pWal;                  /* Write-ahead log used by "journal_mode=wal" */

  51362.   char *zWal;                 /* File name for write-ahead log */

  51363. #endif

  51364. };

  51365. 

  51366. /*

  51367. ** Indexes for use with Pager.aStat[]. The Pager.aStat[] array contains

  51368. ** the values accessed by passing SQLITE_DBSTATUS_CACHE_HIT, CACHE_MISS 

  51369. ** or CACHE_WRITE to sqlite3_db_status().

  51370. */

  51371. #define PAGER_STAT_HIT   0

  51372. #define PAGER_STAT_MISS  1

  51373. #define PAGER_STAT_WRITE 2

  51374. #define PAGER_STAT_SPILL 3

  51375. 

  51376. /*

  51377. ** The following global variables hold counters used for

  51378. ** testing purposes only.  These variables do not exist in

  51379. ** a non-testing build.  These variables are not thread-safe.

  51380. */

  51381. #ifdef SQLITE_TEST

  51382. SQLITE_API int sqlite3_pager_readdb_count = 0;    /* Number of full pages read from DB */

  51383. SQLITE_API int sqlite3_pager_writedb_count = 0;   /* Number of full pages written to DB */

  51384. SQLITE_API int sqlite3_pager_writej_count = 0;    /* Number of pages written to journal */

  51385. # define PAGER_INCR(v)  v++

  51386. #else

  51387. # define PAGER_INCR(v)

  51388. #endif

  51389. 

  51390. 

  51391. 

  51392. /*

  51393. ** Journal files begin with the following magic string.  The data

  51394. ** was obtained from /dev/random.  It is used only as a sanity check.

  51395. **

  51396. ** Since version 2.8.0, the journal format contains additional sanity

  51397. ** checking information.  If the power fails while the journal is being

  51398. ** written, semi-random garbage data might appear in the journal

  51399. ** file after power is restored.  If an attempt is then made

  51400. ** to roll the journal back, the database could be corrupted.  The additional

  51401. ** sanity checking data is an attempt to discover the garbage in the

  51402. ** journal and ignore it.

  51403. **

  51404. ** The sanity checking information for the new journal format consists

  51405. ** of a 32-bit checksum on each page of data.  The checksum covers both

  51406. ** the page number and the pPager->pageSize bytes of data for the page.

  51407. ** This cksum is initialized to a 32-bit random value that appears in the

  51408. ** journal file right after the header.  The random initializer is important,

  51409. ** because garbage data that appears at the end of a journal is likely

  51410. ** data that was once in other files that have now been deleted.  If the

  51411. ** garbage data came from an obsolete journal file, the checksums might

  51412. ** be correct.  But by initializing the checksum to random value which

  51413. ** is different for every journal, we minimize that risk.

  51414. */

  51415. static const unsigned char aJournalMagic[] = {

  51416.   0xd9, 0xd5, 0x05, 0xf9, 0x20, 0xa1, 0x63, 0xd7,

  51417. };

  51418. 

  51419. /*

  51420. ** The size of the of each page record in the journal is given by

  51421. ** the following macro.

  51422. */

  51423. #define JOURNAL_PG_SZ(pPager)  ((pPager->pageSize) + 8)

  51424. 

  51425. /*

  51426. ** The journal header size for this pager. This is usually the same 

  51427. ** size as a single disk sector. See also setSectorSize().

  51428. */

  51429. #define JOURNAL_HDR_SZ(pPager) (pPager->sectorSize)

  51430. 

  51431. /*

  51432. ** The macro MEMDB is true if we are dealing with an in-memory database.

  51433. ** We do this as a macro so that if the SQLITE_OMIT_MEMORYDB macro is set,

  51434. ** the value of MEMDB will be a constant and the compiler will optimize

  51435. ** out code that would never execute.

  51436. */

  51437. #ifdef SQLITE_OMIT_MEMORYDB

  51438. # define MEMDB 0

  51439. #else

  51440. # define MEMDB pPager->memDb

  51441. #endif

  51442. 

  51443. /*

  51444. ** The macro USEFETCH is true if we are allowed to use the xFetch and xUnfetch

  51445. ** interfaces to access the database using memory-mapped I/O.

  51446. */

  51447. #if SQLITE_MAX_MMAP_SIZE>0

  51448. # define USEFETCH(x) ((x)->bUseFetch)

  51449. #else

  51450. # define USEFETCH(x) 0

  51451. #endif

  51452. 

  51453. /*

  51454. ** The maximum legal page number is (2^31 - 1).

  51455. */

  51456. #define PAGER_MAX_PGNO 2147483647

  51457. 

  51458. /*

  51459. ** The argument to this macro is a file descriptor (type sqlite3_file*).

  51460. ** Return 0 if it is not open, or non-zero (but not 1) if it is.

  51461. **

  51462. ** This is so that expressions can be written as:

  51463. **

  51464. **   if( isOpen(pPager->jfd) ){ ...

  51465. **

  51466. ** instead of

  51467. **

  51468. **   if( pPager->jfd->pMethods ){ ...

  51469. */

  51470. #define isOpen(pFd) ((pFd)->pMethods!=0)

  51471. 

  51472. #ifdef SQLITE_DIRECT_OVERFLOW_READ

  51473. /*

  51474. ** Return true if page pgno can be read directly from the database file

  51475. ** by the b-tree layer. This is the case if:

  51476. **

  51477. **   * the database file is open,

  51478. **   * there are no dirty pages in the cache, and

  51479. **   * the desired page is not currently in the wal file.

  51480. */

  51481. SQLITE_PRIVATE int sqlite3PagerDirectReadOk(Pager *pPager, Pgno pgno){

  51482.   if( pPager->fd->pMethods==0 ) return 0;

  51483.   if( sqlite3PCacheIsDirty(pPager->pPCache) ) return 0;

  51484. #ifdef SQLITE_HAS_CODEC

  51485.   if( pPager->xCodec!=0 ) return 0;

  51486. #endif

  51487. #ifndef SQLITE_OMIT_WAL

  51488.   if( pPager->pWal ){

  51489.     u32 iRead = 0;

  51490.     int rc;

  51491.     rc = sqlite3WalFindFrame(pPager->pWal, pgno, &iRead);

  51492.     return (rc==SQLITE_OK && iRead==0);

  51493.   }

  51494. #endif

  51495.   return 1;

  51496. }

  51497. #endif

  51498. 

  51499. #ifndef SQLITE_OMIT_WAL

  51500. # define pagerUseWal(x) ((x)->pWal!=0)

  51501. #else

  51502. # define pagerUseWal(x) 0

  51503. # define pagerRollbackWal(x) 0

  51504. # define pagerWalFrames(v,w,x,y) 0

  51505. # define pagerOpenWalIfPresent(z) SQLITE_OK

  51506. # define pagerBeginReadTransaction(z) SQLITE_OK

  51507. #endif

  51508. 

  51509. #ifndef NDEBUG 

  51510. /*

  51511. ** Usage:

  51512. **

  51513. **   assert( assert_pager_state(pPager) );

  51514. **

  51515. ** This function runs many asserts to try to find inconsistencies in

  51516. ** the internal state of the Pager object.

  51517. */

  51518. static int assert_pager_state(Pager *p){

  51519.   Pager *pPager = p;

  51520. 

  51521.   /* State must be valid. */

  51522.   assert( p->eState==PAGER_OPEN

  51523.        || p->eState==PAGER_READER

  51524.        || p->eState==PAGER_WRITER_LOCKED

  51525.        || p->eState==PAGER_WRITER_CACHEMOD

  51526.        || p->eState==PAGER_WRITER_DBMOD

  51527.        || p->eState==PAGER_WRITER_FINISHED

  51528.        || p->eState==PAGER_ERROR

  51529.   );

  51530. 

  51531.   /* Regardless of the current state, a temp-file connection always behaves

  51532.   ** as if it has an exclusive lock on the database file. It never updates

  51533.   ** the change-counter field, so the changeCountDone flag is always set.

  51534.   */

  51535.   assert( p->tempFile==0 || p->eLock==EXCLUSIVE_LOCK );

  51536.   assert( p->tempFile==0 || pPager->changeCountDone );

  51537. 

  51538.   /* If the useJournal flag is clear, the journal-mode must be "OFF". 

  51539.   ** And if the journal-mode is "OFF", the journal file must not be open.

  51540.   */

  51541.   assert( p->journalMode==PAGER_JOURNALMODE_OFF || p->useJournal );

  51542.   assert( p->journalMode!=PAGER_JOURNALMODE_OFF || !isOpen(p->jfd) );

  51543. 

  51544.   /* Check that MEMDB implies noSync. And an in-memory journal. Since 

  51545.   ** this means an in-memory pager performs no IO at all, it cannot encounter 

  51546.   ** either SQLITE_IOERR or SQLITE_FULL during rollback or while finalizing 

  51547.   ** a journal file. (although the in-memory journal implementation may 

  51548.   ** return SQLITE_IOERR_NOMEM while the journal file is being written). It 

  51549.   ** is therefore not possible for an in-memory pager to enter the ERROR 

  51550.   ** state.

  51551.   */

  51552.   if( MEMDB ){

  51553.     assert( !isOpen(p->fd) );

  51554.     assert( p->noSync );

  51555.     assert( p->journalMode==PAGER_JOURNALMODE_OFF 

  51556.          || p->journalMode==PAGER_JOURNALMODE_MEMORY 

  51557.     );

  51558.     assert( p->eState!=PAGER_ERROR && p->eState!=PAGER_OPEN );

  51559.     assert( pagerUseWal(p)==0 );

  51560.   }

  51561. 

  51562.   /* If changeCountDone is set, a RESERVED lock or greater must be held

  51563.   ** on the file.

  51564.   */

  51565.   assert( pPager->changeCountDone==0 || pPager->eLock>=RESERVED_LOCK );

  51566.   assert( p->eLock!=PENDING_LOCK );

  51567. 

  51568.   switch( p->eState ){

  51569.     case PAGER_OPEN:

  51570.       assert( !MEMDB );

  51571.       assert( pPager->errCode==SQLITE_OK );

  51572.       assert( sqlite3PcacheRefCount(pPager->pPCache)==0 || pPager->tempFile );

  51573.       break;

  51574. 

  51575.     case PAGER_READER:

  51576.       assert( pPager->errCode==SQLITE_OK );

  51577.       assert( p->eLock!=UNKNOWN_LOCK );

  51578.       assert( p->eLock>=SHARED_LOCK );

  51579.       break;

  51580. 

  51581.     case PAGER_WRITER_LOCKED:

  51582.       assert( p->eLock!=UNKNOWN_LOCK );

  51583.       assert( pPager->errCode==SQLITE_OK );

  51584.       if( !pagerUseWal(pPager) ){

  51585.         assert( p->eLock>=RESERVED_LOCK );

  51586.       }

  51587.       assert( pPager->dbSize==pPager->dbOrigSize );

  51588.       assert( pPager->dbOrigSize==pPager->dbFileSize );

  51589.       assert( pPager->dbOrigSize==pPager->dbHintSize );

  51590.       assert( pPager->setMaster==0 );

  51591.       break;

  51592. 

  51593.     case PAGER_WRITER_CACHEMOD:

  51594.       assert( p->eLock!=UNKNOWN_LOCK );

  51595.       assert( pPager->errCode==SQLITE_OK );

  51596.       if( !pagerUseWal(pPager) ){

  51597.         /* It is possible that if journal_mode=wal here that neither the

  51598.         ** journal file nor the WAL file are open. This happens during

  51599.         ** a rollback transaction that switches from journal_mode=off

  51600.         ** to journal_mode=wal.

  51601.         */

  51602.         assert( p->eLock>=RESERVED_LOCK );

  51603.         assert( isOpen(p->jfd) 

  51604.              || p->journalMode==PAGER_JOURNALMODE_OFF 

  51605.              || p->journalMode==PAGER_JOURNALMODE_WAL 

  51606.         );

  51607.       }

  51608.       assert( pPager->dbOrigSize==pPager->dbFileSize );

  51609.       assert( pPager->dbOrigSize==pPager->dbHintSize );

  51610.       break;

  51611. 

  51612.     case PAGER_WRITER_DBMOD:

  51613.       assert( p->eLock==EXCLUSIVE_LOCK );

  51614.       assert( pPager->errCode==SQLITE_OK );

  51615.       assert( !pagerUseWal(pPager) );

  51616.       assert( p->eLock>=EXCLUSIVE_LOCK );

  51617.       assert( isOpen(p->jfd) 

  51618.            || p->journalMode==PAGER_JOURNALMODE_OFF 

  51619.            || p->journalMode==PAGER_JOURNALMODE_WAL 

  51620.            || (sqlite3OsDeviceCharacteristics(p->fd)&SQLITE_IOCAP_BATCH_ATOMIC)

  51621.       );

  51622.       assert( pPager->dbOrigSize<=pPager->dbHintSize );

  51623.       break;

  51624. 

  51625.     case PAGER_WRITER_FINISHED:

  51626.       assert( p->eLock==EXCLUSIVE_LOCK );

  51627.       assert( pPager->errCode==SQLITE_OK );

  51628.       assert( !pagerUseWal(pPager) );

  51629.       assert( isOpen(p->jfd) 

  51630.            || p->journalMode==PAGER_JOURNALMODE_OFF 

  51631.            || p->journalMode==PAGER_JOURNALMODE_WAL 

  51632.            || (sqlite3OsDeviceCharacteristics(p->fd)&SQLITE_IOCAP_BATCH_ATOMIC)

  51633.       );

  51634.       break;

  51635. 

  51636.     case PAGER_ERROR:

  51637.       /* There must be at least one outstanding reference to the pager if

  51638.       ** in ERROR state. Otherwise the pager should have already dropped

  51639.       ** back to OPEN state.

  51640.       */

  51641.       assert( pPager->errCode!=SQLITE_OK );

  51642.       assert( sqlite3PcacheRefCount(pPager->pPCache)>0 || pPager->tempFile );

  51643.       break;

  51644.   }

  51645. 

  51646.   return 1;

  51647. }

  51648. #endif /* ifndef NDEBUG */

  51649. 

  51650. #ifdef SQLITE_DEBUG 

  51651. /*

  51652. ** Return a pointer to a human readable string in a static buffer

  51653. ** containing the state of the Pager object passed as an argument. This

  51654. ** is intended to be used within debuggers. For example, as an alternative

  51655. ** to "print *pPager" in gdb:

  51656. **

  51657. ** (gdb) printf "%s", print_pager_state(pPager)

  51658. **

  51659. ** This routine has external linkage in order to suppress compiler warnings

  51660. ** about an unused function.  It is enclosed within SQLITE_DEBUG and so does

  51661. ** not appear in normal builds.

  51662. */

  51663. char *print_pager_state(Pager *p){

  51664.   static char zRet[1024];

  51665. 

  51666.   sqlite3_snprintf(1024, zRet,

  51667.       "Filename:      %s\n"

  51668.       "State:         %s errCode=%d\n"

  51669.       "Lock:          %s\n"

  51670.       "Locking mode:  locking_mode=%s\n"

  51671.       "Journal mode:  journal_mode=%s\n"

  51672.       "Backing store: tempFile=%d memDb=%d useJournal=%d\n"

  51673.       "Journal:       journalOff=%lld journalHdr=%lld\n"

  51674.       "Size:          dbsize=%d dbOrigSize=%d dbFileSize=%d\n"

  51675.       , p->zFilename

  51676.       , p->eState==PAGER_OPEN            ? "OPEN" :

  51677.         p->eState==PAGER_READER          ? "READER" :

  51678.         p->eState==PAGER_WRITER_LOCKED   ? "WRITER_LOCKED" :

  51679.         p->eState==PAGER_WRITER_CACHEMOD ? "WRITER_CACHEMOD" :

  51680.         p->eState==PAGER_WRITER_DBMOD    ? "WRITER_DBMOD" :

  51681.         p->eState==PAGER_WRITER_FINISHED ? "WRITER_FINISHED" :

  51682.         p->eState==PAGER_ERROR           ? "ERROR" : "?error?"

  51683.       , (int)p->errCode

  51684.       , p->eLock==NO_LOCK         ? "NO_LOCK" :

  51685.         p->eLock==RESERVED_LOCK   ? "RESERVED" :

  51686.         p->eLock==EXCLUSIVE_LOCK  ? "EXCLUSIVE" :

  51687.         p->eLock==SHARED_LOCK     ? "SHARED" :

  51688.         p->eLock==UNKNOWN_LOCK    ? "UNKNOWN" : "?error?"

  51689.       , p->exclusiveMode ? "exclusive" : "normal"

  51690.       , p->journalMode==PAGER_JOURNALMODE_MEMORY   ? "memory" :

  51691.         p->journalMode==PAGER_JOURNALMODE_OFF      ? "off" :

  51692.         p->journalMode==PAGER_JOURNALMODE_DELETE   ? "delete" :

  51693.         p->journalMode==PAGER_JOURNALMODE_PERSIST  ? "persist" :

  51694.         p->journalMode==PAGER_JOURNALMODE_TRUNCATE ? "truncate" :

  51695.         p->journalMode==PAGER_JOURNALMODE_WAL      ? "wal" : "?error?"

  51696.       , (int)p->tempFile, (int)p->memDb, (int)p->useJournal

  51697.       , p->journalOff, p->journalHdr

  51698.       , (int)p->dbSize, (int)p->dbOrigSize, (int)p->dbFileSize

  51699.   );

  51700. 

  51701.   return zRet;

  51702. }

  51703. #endif

  51704. 

  51705. /* Forward references to the various page getters */

  51706. static int getPageNormal(Pager*,Pgno,DbPage**,int);

  51707. static int getPageError(Pager*,Pgno,DbPage**,int);

  51708. #if SQLITE_MAX_MMAP_SIZE>0

  51709. static int getPageMMap(Pager*,Pgno,DbPage**,int);

  51710. #endif

  51711. 

  51712. /*

  51713. ** Set the Pager.xGet method for the appropriate routine used to fetch

  51714. ** content from the pager.

  51715. */

  51716. static void setGetterMethod(Pager *pPager){

  51717.   if( pPager->errCode ){

  51718.     pPager->xGet = getPageError;

  51719. #if SQLITE_MAX_MMAP_SIZE>0

  51720.   }else if( USEFETCH(pPager)

  51721. #ifdef SQLITE_HAS_CODEC

  51722.    && pPager->xCodec==0

  51723. #endif

  51724.   ){

  51725.     pPager->xGet = getPageMMap;

  51726. #endif /* SQLITE_MAX_MMAP_SIZE>0 */

  51727.   }else{

  51728.     pPager->xGet = getPageNormal;

  51729.   }

  51730. }

  51731. 

  51732. /*

  51733. ** Return true if it is necessary to write page *pPg into the sub-journal.

  51734. ** A page needs to be written into the sub-journal if there exists one

  51735. ** or more open savepoints for which:

  51736. **

  51737. **   * The page-number is less than or equal to PagerSavepoint.nOrig, and

  51738. **   * The bit corresponding to the page-number is not set in

  51739. **     PagerSavepoint.pInSavepoint.

  51740. */

  51741. static int subjRequiresPage(PgHdr *pPg){

  51742.   Pager *pPager = pPg->pPager;

  51743.   PagerSavepoint *p;

  51744.   Pgno pgno = pPg->pgno;

  51745.   int i;

  51746.   for(i=0; i<pPager->nSavepoint; i++){

  51747.     p = &pPager->aSavepoint[i];

  51748.     if( p->nOrig>=pgno && 0==sqlite3BitvecTestNotNull(p->pInSavepoint, pgno) ){

  51749.       return 1;

  51750.     }

  51751.   }

  51752.   return 0;

  51753. }

  51754. 

  51755. #ifdef SQLITE_DEBUG

  51756. /*

  51757. ** Return true if the page is already in the journal file.

  51758. */

  51759. static int pageInJournal(Pager *pPager, PgHdr *pPg){

  51760.   return sqlite3BitvecTest(pPager->pInJournal, pPg->pgno);

  51761. }

  51762. #endif

  51763. 

  51764. /*

  51765. ** Read a 32-bit integer from the given file descriptor.  Store the integer

  51766. ** that is read in *pRes.  Return SQLITE_OK if everything worked, or an

  51767. ** error code is something goes wrong.

  51768. **

  51769. ** All values are stored on disk as big-endian.

  51770. */

  51771. static int read32bits(sqlite3_file *fd, i64 offset, u32 *pRes){

  51772.   unsigned char ac[4];

  51773.   int rc = sqlite3OsRead(fd, ac, sizeof(ac), offset);

  51774.   if( rc==SQLITE_OK ){

  51775.     *pRes = sqlite3Get4byte(ac);

  51776.   }

  51777.   return rc;

  51778. }

  51779. 

  51780. /*

  51781. ** Write a 32-bit integer into a string buffer in big-endian byte order.

  51782. */

  51783. #define put32bits(A,B)  sqlite3Put4byte((u8*)A,B)

  51784. 

  51785. 

  51786. /*

  51787. ** Write a 32-bit integer into the given file descriptor.  Return SQLITE_OK

  51788. ** on success or an error code is something goes wrong.

  51789. */

  51790. static int write32bits(sqlite3_file *fd, i64 offset, u32 val){

  51791.   char ac[4];

  51792.   put32bits(ac, val);

  51793.   return sqlite3OsWrite(fd, ac, 4, offset);

  51794. }

  51795. 

  51796. /*

  51797. ** Unlock the database file to level eLock, which must be either NO_LOCK

  51798. ** or SHARED_LOCK. Regardless of whether or not the call to xUnlock()

  51799. ** succeeds, set the Pager.eLock variable to match the (attempted) new lock.

  51800. **

  51801. ** Except, if Pager.eLock is set to UNKNOWN_LOCK when this function is

  51802. ** called, do not modify it. See the comment above the #define of 

  51803. ** UNKNOWN_LOCK for an explanation of this.

  51804. */

  51805. static int pagerUnlockDb(Pager *pPager, int eLock){

  51806.   int rc = SQLITE_OK;

  51807. 

  51808.   assert( !pPager->exclusiveMode || pPager->eLock==eLock );

  51809.   assert( eLock==NO_LOCK || eLock==SHARED_LOCK );

  51810.   assert( eLock!=NO_LOCK || pagerUseWal(pPager)==0 );

  51811.   if( isOpen(pPager->fd) ){

  51812.     assert( pPager->eLock>=eLock );

  51813.     rc = pPager->noLock ? SQLITE_OK : sqlite3OsUnlock(pPager->fd, eLock);

  51814.     if( pPager->eLock!=UNKNOWN_LOCK ){

  51815.       pPager->eLock = (u8)eLock;

  51816.     }

  51817.     IOTRACE(("UNLOCK %p %d\n", pPager, eLock))

  51818.   }

  51819.   return rc;

  51820. }

  51821. 

  51822. /*

  51823. ** Lock the database file to level eLock, which must be either SHARED_LOCK,

  51824. ** RESERVED_LOCK or EXCLUSIVE_LOCK. If the caller is successful, set the

  51825. ** Pager.eLock variable to the new locking state. 

  51826. **

  51827. ** Except, if Pager.eLock is set to UNKNOWN_LOCK when this function is 

  51828. ** called, do not modify it unless the new locking state is EXCLUSIVE_LOCK. 

  51829. ** See the comment above the #define of UNKNOWN_LOCK for an explanation 

  51830. ** of this.

  51831. */

  51832. static int pagerLockDb(Pager *pPager, int eLock){

  51833.   int rc = SQLITE_OK;

  51834. 

  51835.   assert( eLock==SHARED_LOCK || eLock==RESERVED_LOCK || eLock==EXCLUSIVE_LOCK );

  51836.   if( pPager->eLock<eLock || pPager->eLock==UNKNOWN_LOCK ){

  51837.     rc = pPager->noLock ? SQLITE_OK : sqlite3OsLock(pPager->fd, eLock);

  51838.     if( rc==SQLITE_OK && (pPager->eLock!=UNKNOWN_LOCK||eLock==EXCLUSIVE_LOCK) ){

  51839.       pPager->eLock = (u8)eLock;

  51840.       IOTRACE(("LOCK %p %d\n", pPager, eLock))

  51841.     }

  51842.   }

  51843.   return rc;

  51844. }

  51845. 

  51846. /*

  51847. ** This function determines whether or not the atomic-write or

  51848. ** atomic-batch-write optimizations can be used with this pager. The

  51849. ** atomic-write optimization can be used if:

  51850. **

  51851. **  (a) the value returned by OsDeviceCharacteristics() indicates that

  51852. **      a database page may be written atomically, and

  51853. **  (b) the value returned by OsSectorSize() is less than or equal

  51854. **      to the page size.

  51855. **

  51856. ** If it can be used, then the value returned is the size of the journal 

  51857. ** file when it contains rollback data for exactly one page.

  51858. **

  51859. ** The atomic-batch-write optimization can be used if OsDeviceCharacteristics()

  51860. ** returns a value with the SQLITE_IOCAP_BATCH_ATOMIC bit set. -1 is

  51861. ** returned in this case.

  51862. **

  51863. ** If neither optimization can be used, 0 is returned.

  51864. */

  51865. static int jrnlBufferSize(Pager *pPager){

  51866.   assert( !MEMDB );

  51867. 

  51868. #if defined(SQLITE_ENABLE_ATOMIC_WRITE) \

  51869.  || defined(SQLITE_ENABLE_BATCH_ATOMIC_WRITE)

  51870.   int dc;                           /* Device characteristics */

  51871. 

  51872.   assert( isOpen(pPager->fd) );

  51873.   dc = sqlite3OsDeviceCharacteristics(pPager->fd);

  51874. #else

  51875.   UNUSED_PARAMETER(pPager);

  51876. #endif

  51877. 

  51878. #ifdef SQLITE_ENABLE_BATCH_ATOMIC_WRITE

  51879.   if( pPager->dbSize>0 && (dc&SQLITE_IOCAP_BATCH_ATOMIC) ){

  51880.     return -1;

  51881.   }

  51882. #endif

  51883. 

  51884. #ifdef SQLITE_ENABLE_ATOMIC_WRITE

  51885.   {

  51886.     int nSector = pPager->sectorSize;

  51887.     int szPage = pPager->pageSize;

  51888. 

  51889.     assert(SQLITE_IOCAP_ATOMIC512==(512>>8));

  51890.     assert(SQLITE_IOCAP_ATOMIC64K==(65536>>8));

  51891.     if( 0==(dc&(SQLITE_IOCAP_ATOMIC|(szPage>>8)) || nSector>szPage) ){

  51892.       return 0;

  51893.     }

  51894.   }

  51895. 

  51896.   return JOURNAL_HDR_SZ(pPager) + JOURNAL_PG_SZ(pPager);

  51897. #endif

  51898. 

  51899.   return 0;

  51900. }

  51901. 

  51902. /*

  51903. ** If SQLITE_CHECK_PAGES is defined then we do some sanity checking

  51904. ** on the cache using a hash function.  This is used for testing

  51905. ** and debugging only.

  51906. */

  51907. #ifdef SQLITE_CHECK_PAGES

  51908. /*

  51909. ** Return a 32-bit hash of the page data for pPage.

  51910. */

  51911. static u32 pager_datahash(int nByte, unsigned char *pData){

  51912.   u32 hash = 0;

  51913.   int i;

  51914.   for(i=0; i<nByte; i++){

  51915.     hash = (hash*1039) + pData[i];

  51916.   }

  51917.   return hash;

  51918. }

  51919. static u32 pager_pagehash(PgHdr *pPage){

  51920.   return pager_datahash(pPage->pPager->pageSize, (unsigned char *)pPage->pData);

  51921. }

  51922. static void pager_set_pagehash(PgHdr *pPage){

  51923.   pPage->pageHash = pager_pagehash(pPage);

  51924. }

  51925. 

  51926. /*

  51927. ** The CHECK_PAGE macro takes a PgHdr* as an argument. If SQLITE_CHECK_PAGES

  51928. ** is defined, and NDEBUG is not defined, an assert() statement checks

  51929. ** that the page is either dirty or still matches the calculated page-hash.

  51930. */

  51931. #define CHECK_PAGE(x) checkPage(x)

  51932. static void checkPage(PgHdr *pPg){

  51933.   Pager *pPager = pPg->pPager;

  51934.   assert( pPager->eState!=PAGER_ERROR );

  51935.   assert( (pPg->flags&PGHDR_DIRTY) || pPg->pageHash==pager_pagehash(pPg) );

  51936. }

  51937. 

  51938. #else

  51939. #define pager_datahash(X,Y)  0

  51940. #define pager_pagehash(X)  0

  51941. #define pager_set_pagehash(X)

  51942. #define CHECK_PAGE(x)

  51943. #endif  /* SQLITE_CHECK_PAGES */

  51944. 

  51945. /*

  51946. ** When this is called the journal file for pager pPager must be open.

  51947. ** This function attempts to read a master journal file name from the 

  51948. ** end of the file and, if successful, copies it into memory supplied 

  51949. ** by the caller. See comments above writeMasterJournal() for the format

  51950. ** used to store a master journal file name at the end of a journal file.

  51951. **

  51952. ** zMaster must point to a buffer of at least nMaster bytes allocated by

  51953. ** the caller. This should be sqlite3_vfs.mxPathname+1 (to ensure there is

  51954. ** enough space to write the master journal name). If the master journal

  51955. ** name in the journal is longer than nMaster bytes (including a

  51956. ** nul-terminator), then this is handled as if no master journal name

  51957. ** were present in the journal.

  51958. **

  51959. ** If a master journal file name is present at the end of the journal

  51960. ** file, then it is copied into the buffer pointed to by zMaster. A

  51961. ** nul-terminator byte is appended to the buffer following the master

  51962. ** journal file name.

  51963. **

  51964. ** If it is determined that no master journal file name is present 

  51965. ** zMaster[0] is set to 0 and SQLITE_OK returned.

  51966. **

  51967. ** If an error occurs while reading from the journal file, an SQLite

  51968. ** error code is returned.

  51969. */

  51970. static int readMasterJournal(sqlite3_file *pJrnl, char *zMaster, u32 nMaster){

  51971.   int rc;                    /* Return code */

  51972.   u32 len;                   /* Length in bytes of master journal name */

  51973.   i64 szJ;                   /* Total size in bytes of journal file pJrnl */

  51974.   u32 cksum;                 /* MJ checksum value read from journal */

  51975.   u32 u;                     /* Unsigned loop counter */

  51976.   unsigned char aMagic[8];   /* A buffer to hold the magic header */

  51977.   zMaster[0] = '\0';

  51978. 

  51979.   if( SQLITE_OK!=(rc = sqlite3OsFileSize(pJrnl, &szJ))

  51980.    || szJ<16

  51981.    || SQLITE_OK!=(rc = read32bits(pJrnl, szJ-16, &len))

  51982.    || len>=nMaster 

  51983.    || len>szJ-16

  51984.    || len==0 

  51985.    || SQLITE_OK!=(rc = read32bits(pJrnl, szJ-12, &cksum))

  51986.    || SQLITE_OK!=(rc = sqlite3OsRead(pJrnl, aMagic, 8, szJ-8))

  51987.    || memcmp(aMagic, aJournalMagic, 8)

  51988.    || SQLITE_OK!=(rc = sqlite3OsRead(pJrnl, zMaster, len, szJ-16-len))

  51989.   ){

  51990.     return rc;

  51991.   }

  51992. 

  51993.   /* See if the checksum matches the master journal name */

  51994.   for(u=0; u<len; u++){

  51995.     cksum -= zMaster[u];

  51996.   }

  51997.   if( cksum ){

  51998.     /* If the checksum doesn't add up, then one or more of the disk sectors

  51999.     ** containing the master journal filename is corrupted. This means

  52000.     ** definitely roll back, so just return SQLITE_OK and report a (nul)

  52001.     ** master-journal filename.

  52002.     */

  52003.     len = 0;

  52004.   }

  52005.   zMaster[len] = '\0';

  52006.    

  52007.   return SQLITE_OK;

  52008. }

  52009. 

  52010. /*

  52011. ** Return the offset of the sector boundary at or immediately 

  52012. ** following the value in pPager->journalOff, assuming a sector 

  52013. ** size of pPager->sectorSize bytes.

  52014. **

  52015. ** i.e for a sector size of 512:

  52016. **

  52017. **   Pager.journalOff          Return value

  52018. **   ---------------------------------------

  52019. **   0                         0

  52020. **   512                       512

  52021. **   100                       512

  52022. **   2000                      2048

  52023. ** 

  52024. */

  52025. static i64 journalHdrOffset(Pager *pPager){

  52026.   i64 offset = 0;

  52027.   i64 c = pPager->journalOff;

  52028.   if( c ){

  52029.     offset = ((c-1)/JOURNAL_HDR_SZ(pPager) + 1) * JOURNAL_HDR_SZ(pPager);

  52030.   }

  52031.   assert( offset%JOURNAL_HDR_SZ(pPager)==0 );

  52032.   assert( offset>=c );

  52033.   assert( (offset-c)<JOURNAL_HDR_SZ(pPager) );

  52034.   return offset;

  52035. }

  52036. 

  52037. /*

  52038. ** The journal file must be open when this function is called.

  52039. **

  52040. ** This function is a no-op if the journal file has not been written to

  52041. ** within the current transaction (i.e. if Pager.journalOff==0).

  52042. **

  52043. ** If doTruncate is non-zero or the Pager.journalSizeLimit variable is

  52044. ** set to 0, then truncate the journal file to zero bytes in size. Otherwise,

  52045. ** zero the 28-byte header at the start of the journal file. In either case, 

  52046. ** if the pager is not in no-sync mode, sync the journal file immediately 

  52047. ** after writing or truncating it.

  52048. **

  52049. ** If Pager.journalSizeLimit is set to a positive, non-zero value, and

  52050. ** following the truncation or zeroing described above the size of the 

  52051. ** journal file in bytes is larger than this value, then truncate the

  52052. ** journal file to Pager.journalSizeLimit bytes. The journal file does

  52053. ** not need to be synced following this operation.

  52054. **

  52055. ** If an IO error occurs, abandon processing and return the IO error code.

  52056. ** Otherwise, return SQLITE_OK.

  52057. */

  52058. static int zeroJournalHdr(Pager *pPager, int doTruncate){

  52059.   int rc = SQLITE_OK;                               /* Return code */

  52060.   assert( isOpen(pPager->jfd) );

  52061.   assert( !sqlite3JournalIsInMemory(pPager->jfd) );

  52062.   if( pPager->journalOff ){

  52063.     const i64 iLimit = pPager->journalSizeLimit;    /* Local cache of jsl */

  52064. 

  52065.     IOTRACE(("JZEROHDR %p\n", pPager))

  52066.     if( doTruncate || iLimit==0 ){

  52067.       rc = sqlite3OsTruncate(pPager->jfd, 0);

  52068.     }else{

  52069.       static const char zeroHdr[28] = {0};

  52070.       rc = sqlite3OsWrite(pPager->jfd, zeroHdr, sizeof(zeroHdr), 0);

  52071.     }

  52072.     if( rc==SQLITE_OK && !pPager->noSync ){

  52073.       rc = sqlite3OsSync(pPager->jfd, SQLITE_SYNC_DATAONLY|pPager->syncFlags);

  52074.     }

  52075. 

  52076.     /* At this point the transaction is committed but the write lock 

  52077.     ** is still held on the file. If there is a size limit configured for 

  52078.     ** the persistent journal and the journal file currently consumes more

  52079.     ** space than that limit allows for, truncate it now. There is no need

  52080.     ** to sync the file following this operation.

  52081.     */

  52082.     if( rc==SQLITE_OK && iLimit>0 ){

  52083.       i64 sz;

  52084.       rc = sqlite3OsFileSize(pPager->jfd, &sz);

  52085.       if( rc==SQLITE_OK && sz>iLimit ){

  52086.         rc = sqlite3OsTruncate(pPager->jfd, iLimit);

  52087.       }

  52088.     }

  52089.   }

  52090.   return rc;

  52091. }

  52092. 

  52093. /*

  52094. ** The journal file must be open when this routine is called. A journal

  52095. ** header (JOURNAL_HDR_SZ bytes) is written into the journal file at the

  52096. ** current location.

  52097. **

  52098. ** The format for the journal header is as follows:

  52099. ** - 8 bytes: Magic identifying journal format.

  52100. ** - 4 bytes: Number of records in journal, or -1 no-sync mode is on.

  52101. ** - 4 bytes: Random number used for page hash.

  52102. ** - 4 bytes: Initial database page count.

  52103. ** - 4 bytes: Sector size used by the process that wrote this journal.

  52104. ** - 4 bytes: Database page size.

  52105. ** 

  52106. ** Followed by (JOURNAL_HDR_SZ - 28) bytes of unused space.

  52107. */

  52108. static int writeJournalHdr(Pager *pPager){

  52109.   int rc = SQLITE_OK;                 /* Return code */

  52110.   char *zHeader = pPager->pTmpSpace;  /* Temporary space used to build header */

  52111.   u32 nHeader = (u32)pPager->pageSize;/* Size of buffer pointed to by zHeader */

  52112.   u32 nWrite;                         /* Bytes of header sector written */

  52113.   int ii;                             /* Loop counter */

  52114. 

  52115.   assert( isOpen(pPager->jfd) );      /* Journal file must be open. */

  52116. 

  52117.   if( nHeader>JOURNAL_HDR_SZ(pPager) ){

  52118.     nHeader = JOURNAL_HDR_SZ(pPager);

  52119.   }

  52120. 

  52121.   /* If there are active savepoints and any of them were created 

  52122.   ** since the most recent journal header was written, update the 

  52123.   ** PagerSavepoint.iHdrOffset fields now.

  52124.   */

  52125.   for(ii=0; ii<pPager->nSavepoint; ii++){

  52126.     if( pPager->aSavepoint[ii].iHdrOffset==0 ){

  52127.       pPager->aSavepoint[ii].iHdrOffset = pPager->journalOff;

  52128.     }

  52129.   }

  52130. 

  52131.   pPager->journalHdr = pPager->journalOff = journalHdrOffset(pPager);

  52132. 

  52133.   /* 

  52134.   ** Write the nRec Field - the number of page records that follow this

  52135.   ** journal header. Normally, zero is written to this value at this time.

  52136.   ** After the records are added to the journal (and the journal synced, 

  52137.   ** if in full-sync mode), the zero is overwritten with the true number

  52138.   ** of records (see syncJournal()).

  52139.   **

  52140.   ** A faster alternative is to write 0xFFFFFFFF to the nRec field. When

  52141.   ** reading the journal this value tells SQLite to assume that the

  52142.   ** rest of the journal file contains valid page records. This assumption

  52143.   ** is dangerous, as if a failure occurred whilst writing to the journal

  52144.   ** file it may contain some garbage data. There are two scenarios

  52145.   ** where this risk can be ignored:

  52146.   **

  52147.   **   * When the pager is in no-sync mode. Corruption can follow a

  52148.   **     power failure in this case anyway.

  52149.   **

  52150.   **   * When the SQLITE_IOCAP_SAFE_APPEND flag is set. This guarantees

  52151.   **     that garbage data is never appended to the journal file.

  52152.   */

  52153.   assert( isOpen(pPager->fd) || pPager->noSync );

  52154.   if( pPager->noSync || (pPager->journalMode==PAGER_JOURNALMODE_MEMORY)

  52155.    || (sqlite3OsDeviceCharacteristics(pPager->fd)&SQLITE_IOCAP_SAFE_APPEND) 

  52156.   ){

  52157.     memcpy(zHeader, aJournalMagic, sizeof(aJournalMagic));

  52158.     put32bits(&zHeader[sizeof(aJournalMagic)], 0xffffffff);

  52159.   }else{

  52160.     memset(zHeader, 0, sizeof(aJournalMagic)+4);

  52161.   }

  52162. 

  52163.   /* The random check-hash initializer */ 

  52164.   sqlite3_randomness(sizeof(pPager->cksumInit), &pPager->cksumInit);

  52165.   put32bits(&zHeader[sizeof(aJournalMagic)+4], pPager->cksumInit);

  52166.   /* The initial database size */

  52167.   put32bits(&zHeader[sizeof(aJournalMagic)+8], pPager->dbOrigSize);

  52168.   /* The assumed sector size for this process */

  52169.   put32bits(&zHeader[sizeof(aJournalMagic)+12], pPager->sectorSize);

  52170. 

  52171.   /* The page size */

  52172.   put32bits(&zHeader[sizeof(aJournalMagic)+16], pPager->pageSize);

  52173. 

  52174.   /* Initializing the tail of the buffer is not necessary.  Everything

  52175.   ** works find if the following memset() is omitted.  But initializing

  52176.   ** the memory prevents valgrind from complaining, so we are willing to

  52177.   ** take the performance hit.

  52178.   */

  52179.   memset(&zHeader[sizeof(aJournalMagic)+20], 0,

  52180.          nHeader-(sizeof(aJournalMagic)+20));

  52181. 

  52182.   /* In theory, it is only necessary to write the 28 bytes that the 

  52183.   ** journal header consumes to the journal file here. Then increment the 

  52184.   ** Pager.journalOff variable by JOURNAL_HDR_SZ so that the next 

  52185.   ** record is written to the following sector (leaving a gap in the file

  52186.   ** that will be implicitly filled in by the OS).

  52187.   **

  52188.   ** However it has been discovered that on some systems this pattern can 

  52189.   ** be significantly slower than contiguously writing data to the file,

  52190.   ** even if that means explicitly writing data to the block of 

  52191.   ** (JOURNAL_HDR_SZ - 28) bytes that will not be used. So that is what

  52192.   ** is done. 

  52193.   **

  52194.   ** The loop is required here in case the sector-size is larger than the 

  52195.   ** database page size. Since the zHeader buffer is only Pager.pageSize

  52196.   ** bytes in size, more than one call to sqlite3OsWrite() may be required

  52197.   ** to populate the entire journal header sector.

  52198.   */ 

  52199.   for(nWrite=0; rc==SQLITE_OK&&nWrite<JOURNAL_HDR_SZ(pPager); nWrite+=nHeader){

  52200.     IOTRACE(("JHDR %p %lld %d\n", pPager, pPager->journalHdr, nHeader))

  52201.     rc = sqlite3OsWrite(pPager->jfd, zHeader, nHeader, pPager->journalOff);

  52202.     assert( pPager->journalHdr <= pPager->journalOff );

  52203.     pPager->journalOff += nHeader;

  52204.   }

  52205. 

  52206.   return rc;

  52207. }

  52208. 

  52209. /*

  52210. ** The journal file must be open when this is called. A journal header file

  52211. ** (JOURNAL_HDR_SZ bytes) is read from the current location in the journal

  52212. ** file. The current location in the journal file is given by

  52213. ** pPager->journalOff. See comments above function writeJournalHdr() for

  52214. ** a description of the journal header format.

  52215. **

  52216. ** If the header is read successfully, *pNRec is set to the number of

  52217. ** page records following this header and *pDbSize is set to the size of the

  52218. ** database before the transaction began, in pages. Also, pPager->cksumInit

  52219. ** is set to the value read from the journal header. SQLITE_OK is returned

  52220. ** in this case.

  52221. **

  52222. ** If the journal header file appears to be corrupted, SQLITE_DONE is

  52223. ** returned and *pNRec and *PDbSize are undefined.  If JOURNAL_HDR_SZ bytes

  52224. ** cannot be read from the journal file an error code is returned.

  52225. */

  52226. static int readJournalHdr(

  52227.   Pager *pPager,               /* Pager object */

  52228.   int isHot,

  52229.   i64 journalSize,             /* Size of the open journal file in bytes */

  52230.   u32 *pNRec,                  /* OUT: Value read from the nRec field */

  52231.   u32 *pDbSize                 /* OUT: Value of original database size field */

  52232. ){

  52233.   int rc;                      /* Return code */

  52234.   unsigned char aMagic[8];     /* A buffer to hold the magic header */

  52235.   i64 iHdrOff;                 /* Offset of journal header being read */

  52236. 

  52237.   assert( isOpen(pPager->jfd) );      /* Journal file must be open. */

  52238. 

  52239.   /* Advance Pager.journalOff to the start of the next sector. If the

  52240.   ** journal file is too small for there to be a header stored at this

  52241.   ** point, return SQLITE_DONE.

  52242.   */

  52243.   pPager->journalOff = journalHdrOffset(pPager);

  52244.   if( pPager->journalOff+JOURNAL_HDR_SZ(pPager) > journalSize ){

  52245.     return SQLITE_DONE;

  52246.   }

  52247.   iHdrOff = pPager->journalOff;

  52248. 

  52249.   /* Read in the first 8 bytes of the journal header. If they do not match

  52250.   ** the  magic string found at the start of each journal header, return

  52251.   ** SQLITE_DONE. If an IO error occurs, return an error code. Otherwise,

  52252.   ** proceed.

  52253.   */

  52254.   if( isHot || iHdrOff!=pPager->journalHdr ){

  52255.     rc = sqlite3OsRead(pPager->jfd, aMagic, sizeof(aMagic), iHdrOff);

  52256.     if( rc ){

  52257.       return rc;

  52258.     }

  52259.     if( memcmp(aMagic, aJournalMagic, sizeof(aMagic))!=0 ){

  52260.       return SQLITE_DONE;

  52261.     }

  52262.   }

  52263. 

  52264.   /* Read the first three 32-bit fields of the journal header: The nRec

  52265.   ** field, the checksum-initializer and the database size at the start

  52266.   ** of the transaction. Return an error code if anything goes wrong.

  52267.   */

  52268.   if( SQLITE_OK!=(rc = read32bits(pPager->jfd, iHdrOff+8, pNRec))

  52269.    || SQLITE_OK!=(rc = read32bits(pPager->jfd, iHdrOff+12, &pPager->cksumInit))

  52270.    || SQLITE_OK!=(rc = read32bits(pPager->jfd, iHdrOff+16, pDbSize))

  52271.   ){

  52272.     return rc;

  52273.   }

  52274. 

  52275.   if( pPager->journalOff==0 ){

  52276.     u32 iPageSize;               /* Page-size field of journal header */

  52277.     u32 iSectorSize;             /* Sector-size field of journal header */

  52278. 

  52279.     /* Read the page-size and sector-size journal header fields. */

  52280.     if( SQLITE_OK!=(rc = read32bits(pPager->jfd, iHdrOff+20, &iSectorSize))

  52281.      || SQLITE_OK!=(rc = read32bits(pPager->jfd, iHdrOff+24, &iPageSize))

  52282.     ){

  52283.       return rc;

  52284.     }

  52285. 

  52286.     /* Versions of SQLite prior to 3.5.8 set the page-size field of the

  52287.     ** journal header to zero. In this case, assume that the Pager.pageSize

  52288.     ** variable is already set to the correct page size.

  52289.     */

  52290.     if( iPageSize==0 ){

  52291.       iPageSize = pPager->pageSize;

  52292.     }

  52293. 

  52294.     /* Check that the values read from the page-size and sector-size fields

  52295.     ** are within range. To be 'in range', both values need to be a power

  52296.     ** of two greater than or equal to 512 or 32, and not greater than their 

  52297.     ** respective compile time maximum limits.

  52298.     */

  52299.     if( iPageSize<512                  || iSectorSize<32

  52300.      || iPageSize>SQLITE_MAX_PAGE_SIZE || iSectorSize>MAX_SECTOR_SIZE

  52301.      || ((iPageSize-1)&iPageSize)!=0   || ((iSectorSize-1)&iSectorSize)!=0 

  52302.     ){

  52303.       /* If the either the page-size or sector-size in the journal-header is 

  52304.       ** invalid, then the process that wrote the journal-header must have 

  52305.       ** crashed before the header was synced. In this case stop reading 

  52306.       ** the journal file here.

  52307.       */

  52308.       return SQLITE_DONE;

  52309.     }

  52310. 

  52311.     /* Update the page-size to match the value read from the journal. 

  52312.     ** Use a testcase() macro to make sure that malloc failure within 

  52313.     ** PagerSetPagesize() is tested.

  52314.     */

  52315.     rc = sqlite3PagerSetPagesize(pPager, &iPageSize, -1);

  52316.     testcase( rc!=SQLITE_OK );

  52317. 

  52318.     /* Update the assumed sector-size to match the value used by 

  52319.     ** the process that created this journal. If this journal was

  52320.     ** created by a process other than this one, then this routine

  52321.     ** is being called from within pager_playback(). The local value

  52322.     ** of Pager.sectorSize is restored at the end of that routine.

  52323.     */

  52324.     pPager->sectorSize = iSectorSize;

  52325.   }

  52326. 

  52327.   pPager->journalOff += JOURNAL_HDR_SZ(pPager);

  52328.   return rc;

  52329. }

  52330. 

  52331. 

  52332. /*

  52333. ** Write the supplied master journal name into the journal file for pager

  52334. ** pPager at the current location. The master journal name must be the last

  52335. ** thing written to a journal file. If the pager is in full-sync mode, the

  52336. ** journal file descriptor is advanced to the next sector boundary before

  52337. ** anything is written. The format is:

  52338. **

  52339. **   + 4 bytes: PAGER_MJ_PGNO.

  52340. **   + N bytes: Master journal filename in utf-8.

  52341. **   + 4 bytes: N (length of master journal name in bytes, no nul-terminator).

  52342. **   + 4 bytes: Master journal name checksum.

  52343. **   + 8 bytes: aJournalMagic[].

  52344. **

  52345. ** The master journal page checksum is the sum of the bytes in the master

  52346. ** journal name, where each byte is interpreted as a signed 8-bit integer.

  52347. **

  52348. ** If zMaster is a NULL pointer (occurs for a single database transaction), 

  52349. ** this call is a no-op.

  52350. */

  52351. static int writeMasterJournal(Pager *pPager, const char *zMaster){

  52352.   int rc;                          /* Return code */

  52353.   int nMaster;                     /* Length of string zMaster */

  52354.   i64 iHdrOff;                     /* Offset of header in journal file */

  52355.   i64 jrnlSize;                    /* Size of journal file on disk */

  52356.   u32 cksum = 0;                   /* Checksum of string zMaster */

  52357. 

  52358.   assert( pPager->setMaster==0 );

  52359.   assert( !pagerUseWal(pPager) );

  52360. 

  52361.   if( !zMaster 

  52362.    || pPager->journalMode==PAGER_JOURNALMODE_MEMORY 

  52363.    || !isOpen(pPager->jfd)

  52364.   ){

  52365.     return SQLITE_OK;

  52366.   }

  52367.   pPager->setMaster = 1;

  52368.   assert( pPager->journalHdr <= pPager->journalOff );

  52369. 

  52370.   /* Calculate the length in bytes and the checksum of zMaster */

  52371.   for(nMaster=0; zMaster[nMaster]; nMaster++){

  52372.     cksum += zMaster[nMaster];

  52373.   }

  52374. 

  52375.   /* If in full-sync mode, advance to the next disk sector before writing

  52376.   ** the master journal name. This is in case the previous page written to

  52377.   ** the journal has already been synced.

  52378.   */

  52379.   if( pPager->fullSync ){

  52380.     pPager->journalOff = journalHdrOffset(pPager);

  52381.   }

  52382.   iHdrOff = pPager->journalOff;

  52383. 

  52384.   /* Write the master journal data to the end of the journal file. If

  52385.   ** an error occurs, return the error code to the caller.

  52386.   */

  52387.   if( (0 != (rc = write32bits(pPager->jfd, iHdrOff, PAGER_MJ_PGNO(pPager))))

  52388.    || (0 != (rc = sqlite3OsWrite(pPager->jfd, zMaster, nMaster, iHdrOff+4)))

  52389.    || (0 != (rc = write32bits(pPager->jfd, iHdrOff+4+nMaster, nMaster)))

  52390.    || (0 != (rc = write32bits(pPager->jfd, iHdrOff+4+nMaster+4, cksum)))

  52391.    || (0 != (rc = sqlite3OsWrite(pPager->jfd, aJournalMagic, 8,

  52392.                                  iHdrOff+4+nMaster+8)))

  52393.   ){

  52394.     return rc;

  52395.   }

  52396.   pPager->journalOff += (nMaster+20);

  52397. 

  52398.   /* If the pager is in peristent-journal mode, then the physical 

  52399.   ** journal-file may extend past the end of the master-journal name

  52400.   ** and 8 bytes of magic data just written to the file. This is 

  52401.   ** dangerous because the code to rollback a hot-journal file

  52402.   ** will not be able to find the master-journal name to determine 

  52403.   ** whether or not the journal is hot. 

  52404.   **

  52405.   ** Easiest thing to do in this scenario is to truncate the journal 

  52406.   ** file to the required size.

  52407.   */ 

  52408.   if( SQLITE_OK==(rc = sqlite3OsFileSize(pPager->jfd, &jrnlSize))

  52409.    && jrnlSize>pPager->journalOff

  52410.   ){

  52411.     rc = sqlite3OsTruncate(pPager->jfd, pPager->journalOff);

  52412.   }

  52413.   return rc;

  52414. }

  52415. 

  52416. /*

  52417. ** Discard the entire contents of the in-memory page-cache.

  52418. */

  52419. static void pager_reset(Pager *pPager){

  52420.   pPager->iDataVersion++;

  52421.   sqlite3BackupRestart(pPager->pBackup);

  52422.   sqlite3PcacheClear(pPager->pPCache);

  52423. }

  52424. 

  52425. /*

  52426. ** Return the pPager->iDataVersion value

  52427. */

  52428. SQLITE_PRIVATE u32 sqlite3PagerDataVersion(Pager *pPager){

  52429.   return pPager->iDataVersion;

  52430. }

  52431. 

  52432. /*

  52433. ** Free all structures in the Pager.aSavepoint[] array and set both

  52434. ** Pager.aSavepoint and Pager.nSavepoint to zero. Close the sub-journal

  52435. ** if it is open and the pager is not in exclusive mode.

  52436. */

  52437. static void releaseAllSavepoints(Pager *pPager){

  52438.   int ii;               /* Iterator for looping through Pager.aSavepoint */

  52439.   for(ii=0; ii<pPager->nSavepoint; ii++){

  52440.     sqlite3BitvecDestroy(pPager->aSavepoint[ii].pInSavepoint);

  52441.   }

  52442.   if( !pPager->exclusiveMode || sqlite3JournalIsInMemory(pPager->sjfd) ){

  52443.     sqlite3OsClose(pPager->sjfd);

  52444.   }

  52445.   sqlite3_free(pPager->aSavepoint);

  52446.   pPager->aSavepoint = 0;

  52447.   pPager->nSavepoint = 0;

  52448.   pPager->nSubRec = 0;

  52449. }

  52450. 

  52451. /*

  52452. ** Set the bit number pgno in the PagerSavepoint.pInSavepoint 

  52453. ** bitvecs of all open savepoints. Return SQLITE_OK if successful

  52454. ** or SQLITE_NOMEM if a malloc failure occurs.

  52455. */

  52456. static int addToSavepointBitvecs(Pager *pPager, Pgno pgno){

  52457.   int ii;                   /* Loop counter */

  52458.   int rc = SQLITE_OK;       /* Result code */

  52459. 

  52460.   for(ii=0; ii<pPager->nSavepoint; ii++){

  52461.     PagerSavepoint *p = &pPager->aSavepoint[ii];

  52462.     if( pgno<=p->nOrig ){

  52463.       rc |= sqlite3BitvecSet(p->pInSavepoint, pgno);

  52464.       testcase( rc==SQLITE_NOMEM );

  52465.       assert( rc==SQLITE_OK || rc==SQLITE_NOMEM );

  52466.     }

  52467.   }

  52468.   return rc;

  52469. }

  52470. 

  52471. /*

  52472. ** This function is a no-op if the pager is in exclusive mode and not

  52473. ** in the ERROR state. Otherwise, it switches the pager to PAGER_OPEN

  52474. ** state.

  52475. **

  52476. ** If the pager is not in exclusive-access mode, the database file is

  52477. ** completely unlocked. If the file is unlocked and the file-system does

  52478. ** not exhibit the UNDELETABLE_WHEN_OPEN property, the journal file is

  52479. ** closed (if it is open).

  52480. **

  52481. ** If the pager is in ERROR state when this function is called, the 

  52482. ** contents of the pager cache are discarded before switching back to 

  52483. ** the OPEN state. Regardless of whether the pager is in exclusive-mode

  52484. ** or not, any journal file left in the file-system will be treated

  52485. ** as a hot-journal and rolled back the next time a read-transaction

  52486. ** is opened (by this or by any other connection).

  52487. */

  52488. static void pager_unlock(Pager *pPager){

  52489. 

  52490.   assert( pPager->eState==PAGER_READER 

  52491.        || pPager->eState==PAGER_OPEN 

  52492.        || pPager->eState==PAGER_ERROR 

  52493.   );

  52494. 

  52495.   sqlite3BitvecDestroy(pPager->pInJournal);

  52496.   pPager->pInJournal = 0;

  52497.   releaseAllSavepoints(pPager);

  52498. 

  52499.   if( pagerUseWal(pPager) ){

  52500.     assert( !isOpen(pPager->jfd) );

  52501.     sqlite3WalEndReadTransaction(pPager->pWal);

  52502.     pPager->eState = PAGER_OPEN;

  52503.   }else if( !pPager->exclusiveMode ){

  52504.     int rc;                       /* Error code returned by pagerUnlockDb() */

  52505.     int iDc = isOpen(pPager->fd)?sqlite3OsDeviceCharacteristics(pPager->fd):0;

  52506. 

  52507.     /* If the operating system support deletion of open files, then

  52508.     ** close the journal file when dropping the database lock.  Otherwise

  52509.     ** another connection with journal_mode=delete might delete the file

  52510.     ** out from under us.

  52511.     */

  52512.     assert( (PAGER_JOURNALMODE_MEMORY   & 5)!=1 );

  52513.     assert( (PAGER_JOURNALMODE_OFF      & 5)!=1 );

  52514.     assert( (PAGER_JOURNALMODE_WAL      & 5)!=1 );

  52515.     assert( (PAGER_JOURNALMODE_DELETE   & 5)!=1 );

  52516.     assert( (PAGER_JOURNALMODE_TRUNCATE & 5)==1 );

  52517.     assert( (PAGER_JOURNALMODE_PERSIST  & 5)==1 );

  52518.     if( 0==(iDc & SQLITE_IOCAP_UNDELETABLE_WHEN_OPEN)

  52519.      || 1!=(pPager->journalMode & 5)

  52520.     ){

  52521.       sqlite3OsClose(pPager->jfd);

  52522.     }

  52523. 

  52524.     /* If the pager is in the ERROR state and the call to unlock the database

  52525.     ** file fails, set the current lock to UNKNOWN_LOCK. See the comment

  52526.     ** above the #define for UNKNOWN_LOCK for an explanation of why this

  52527.     ** is necessary.

  52528.     */

  52529.     rc = pagerUnlockDb(pPager, NO_LOCK);

  52530.     if( rc!=SQLITE_OK && pPager->eState==PAGER_ERROR ){

  52531.       pPager->eLock = UNKNOWN_LOCK;

  52532.     }

  52533. 

  52534.     /* The pager state may be changed from PAGER_ERROR to PAGER_OPEN here

  52535.     ** without clearing the error code. This is intentional - the error

  52536.     ** code is cleared and the cache reset in the block below.

  52537.     */

  52538.     assert( pPager->errCode || pPager->eState!=PAGER_ERROR );

  52539.     pPager->changeCountDone = 0;

  52540.     pPager->eState = PAGER_OPEN;

  52541.   }

  52542. 

  52543.   /* If Pager.errCode is set, the contents of the pager cache cannot be

  52544.   ** trusted. Now that there are no outstanding references to the pager,

  52545.   ** it can safely move back to PAGER_OPEN state. This happens in both

  52546.   ** normal and exclusive-locking mode.

  52547.   */

  52548.   assert( pPager->errCode==SQLITE_OK || !MEMDB );

  52549.   if( pPager->errCode ){

  52550.     if( pPager->tempFile==0 ){

  52551.       pager_reset(pPager);

  52552.       pPager->changeCountDone = 0;

  52553.       pPager->eState = PAGER_OPEN;

  52554.     }else{

  52555.       pPager->eState = (isOpen(pPager->jfd) ? PAGER_OPEN : PAGER_READER);

  52556.     }

  52557.     if( USEFETCH(pPager) ) sqlite3OsUnfetch(pPager->fd, 0, 0);

  52558.     pPager->errCode = SQLITE_OK;

  52559.     setGetterMethod(pPager);

  52560.   }

  52561. 

  52562.   pPager->journalOff = 0;

  52563.   pPager->journalHdr = 0;

  52564.   pPager->setMaster = 0;

  52565. }

  52566. 

  52567. /*

  52568. ** This function is called whenever an IOERR or FULL error that requires

  52569. ** the pager to transition into the ERROR state may ahve occurred.

  52570. ** The first argument is a pointer to the pager structure, the second 

  52571. ** the error-code about to be returned by a pager API function. The 

  52572. ** value returned is a copy of the second argument to this function. 

  52573. **

  52574. ** If the second argument is SQLITE_FULL, SQLITE_IOERR or one of the

  52575. ** IOERR sub-codes, the pager enters the ERROR state and the error code

  52576. ** is stored in Pager.errCode. While the pager remains in the ERROR state,

  52577. ** all major API calls on the Pager will immediately return Pager.errCode.

  52578. **

  52579. ** The ERROR state indicates that the contents of the pager-cache 

  52580. ** cannot be trusted. This state can be cleared by completely discarding 

  52581. ** the contents of the pager-cache. If a transaction was active when

  52582. ** the persistent error occurred, then the rollback journal may need

  52583. ** to be replayed to restore the contents of the database file (as if

  52584. ** it were a hot-journal).

  52585. */

  52586. static int pager_error(Pager *pPager, int rc){

  52587.   int rc2 = rc & 0xff;

  52588.   assert( rc==SQLITE_OK || !MEMDB );

  52589.   assert(

  52590.        pPager->errCode==SQLITE_FULL ||

  52591.        pPager->errCode==SQLITE_OK ||

  52592.        (pPager->errCode & 0xff)==SQLITE_IOERR

  52593.   );

  52594.   if( rc2==SQLITE_FULL || rc2==SQLITE_IOERR ){

  52595.     pPager->errCode = rc;

  52596.     pPager->eState = PAGER_ERROR;

  52597.     setGetterMethod(pPager);

  52598.   }

  52599.   return rc;

  52600. }

  52601. 

  52602. static int pager_truncate(Pager *pPager, Pgno nPage);

  52603. 

  52604. /*

  52605. ** The write transaction open on pPager is being committed (bCommit==1)

  52606. ** or rolled back (bCommit==0).

  52607. **

  52608. ** Return TRUE if and only if all dirty pages should be flushed to disk.

  52609. **

  52610. ** Rules:

  52611. **

  52612. **   *  For non-TEMP databases, always sync to disk.  This is necessary

  52613. **      for transactions to be durable.

  52614. **

  52615. **   *  Sync TEMP database only on a COMMIT (not a ROLLBACK) when the backing

  52616. **      file has been created already (via a spill on pagerStress()) and

  52617. **      when the number of dirty pages in memory exceeds 25% of the total

  52618. **      cache size.

  52619. */

  52620. static int pagerFlushOnCommit(Pager *pPager, int bCommit){

  52621.   if( pPager->tempFile==0 ) return 1;

  52622.   if( !bCommit ) return 0;

  52623.   if( !isOpen(pPager->fd) ) return 0;

  52624.   return (sqlite3PCachePercentDirty(pPager->pPCache)>=25);

  52625. }

  52626. 

  52627. /*

  52628. ** This routine ends a transaction. A transaction is usually ended by 

  52629. ** either a COMMIT or a ROLLBACK operation. This routine may be called 

  52630. ** after rollback of a hot-journal, or if an error occurs while opening

  52631. ** the journal file or writing the very first journal-header of a

  52632. ** database transaction.

  52633. ** 

  52634. ** This routine is never called in PAGER_ERROR state. If it is called

  52635. ** in PAGER_NONE or PAGER_SHARED state and the lock held is less

  52636. ** exclusive than a RESERVED lock, it is a no-op.

  52637. **

  52638. ** Otherwise, any active savepoints are released.

  52639. **

  52640. ** If the journal file is open, then it is "finalized". Once a journal 

  52641. ** file has been finalized it is not possible to use it to roll back a 

  52642. ** transaction. Nor will it be considered to be a hot-journal by this

  52643. ** or any other database connection. Exactly how a journal is finalized

  52644. ** depends on whether or not the pager is running in exclusive mode and

  52645. ** the current journal-mode (Pager.journalMode value), as follows:

  52646. **

  52647. **   journalMode==MEMORY

  52648. **     Journal file descriptor is simply closed. This destroys an 

  52649. **     in-memory journal.

  52650. **

  52651. **   journalMode==TRUNCATE

  52652. **     Journal file is truncated to zero bytes in size.

  52653. **

  52654. **   journalMode==PERSIST

  52655. **     The first 28 bytes of the journal file are zeroed. This invalidates

  52656. **     the first journal header in the file, and hence the entire journal

  52657. **     file. An invalid journal file cannot be rolled back.

  52658. **

  52659. **   journalMode==DELETE

  52660. **     The journal file is closed and deleted using sqlite3OsDelete().

  52661. **

  52662. **     If the pager is running in exclusive mode, this method of finalizing

  52663. **     the journal file is never used. Instead, if the journalMode is

  52664. **     DELETE and the pager is in exclusive mode, the method described under

  52665. **     journalMode==PERSIST is used instead.

  52666. **

  52667. ** After the journal is finalized, the pager moves to PAGER_READER state.

  52668. ** If running in non-exclusive rollback mode, the lock on the file is 

  52669. ** downgraded to a SHARED_LOCK.

  52670. **

  52671. ** SQLITE_OK is returned if no error occurs. If an error occurs during

  52672. ** any of the IO operations to finalize the journal file or unlock the

  52673. ** database then the IO error code is returned to the user. If the 

  52674. ** operation to finalize the journal file fails, then the code still

  52675. ** tries to unlock the database file if not in exclusive mode. If the

  52676. ** unlock operation fails as well, then the first error code related

  52677. ** to the first error encountered (the journal finalization one) is

  52678. ** returned.

  52679. */

  52680. static int pager_end_transaction(Pager *pPager, int hasMaster, int bCommit){

  52681.   int rc = SQLITE_OK;      /* Error code from journal finalization operation */

  52682.   int rc2 = SQLITE_OK;     /* Error code from db file unlock operation */

  52683. 

  52684.   /* Do nothing if the pager does not have an open write transaction

  52685.   ** or at least a RESERVED lock. This function may be called when there

  52686.   ** is no write-transaction active but a RESERVED or greater lock is

  52687.   ** held under two circumstances:

  52688.   **

  52689.   **   1. After a successful hot-journal rollback, it is called with

  52690.   **      eState==PAGER_NONE and eLock==EXCLUSIVE_LOCK.

  52691.   **

  52692.   **   2. If a connection with locking_mode=exclusive holding an EXCLUSIVE 

  52693.   **      lock switches back to locking_mode=normal and then executes a

  52694.   **      read-transaction, this function is called with eState==PAGER_READER 

  52695.   **      and eLock==EXCLUSIVE_LOCK when the read-transaction is closed.

  52696.   */

  52697.   assert( assert_pager_state(pPager) );

  52698.   assert( pPager->eState!=PAGER_ERROR );

  52699.   if( pPager->eState<PAGER_WRITER_LOCKED && pPager->eLock<RESERVED_LOCK ){

  52700.     return SQLITE_OK;

  52701.   }

  52702. 

  52703.   releaseAllSavepoints(pPager);

  52704.   assert( isOpen(pPager->jfd) || pPager->pInJournal==0 

  52705.       || (sqlite3OsDeviceCharacteristics(pPager->fd)&SQLITE_IOCAP_BATCH_ATOMIC)

  52706.   );

  52707.   if( isOpen(pPager->jfd) ){

  52708.     assert( !pagerUseWal(pPager) );

  52709. 

  52710.     /* Finalize the journal file. */

  52711.     if( sqlite3JournalIsInMemory(pPager->jfd) ){

  52712.       /* assert( pPager->journalMode==PAGER_JOURNALMODE_MEMORY ); */

  52713.       sqlite3OsClose(pPager->jfd);

  52714.     }else if( pPager->journalMode==PAGER_JOURNALMODE_TRUNCATE ){

  52715.       if( pPager->journalOff==0 ){

  52716.         rc = SQLITE_OK;

  52717.       }else{

  52718.         rc = sqlite3OsTruncate(pPager->jfd, 0);

  52719.         if( rc==SQLITE_OK && pPager->fullSync ){

  52720.           /* Make sure the new file size is written into the inode right away.

  52721.           ** Otherwise the journal might resurrect following a power loss and

  52722.           ** cause the last transaction to roll back.  See

  52723.           ** https://bugzilla.mozilla.org/show_bug.cgi?id=1072773

  52724.           */

  52725.           rc = sqlite3OsSync(pPager->jfd, pPager->syncFlags);

  52726.         }

  52727.       }

  52728.       pPager->journalOff = 0;

  52729.     }else if( pPager->journalMode==PAGER_JOURNALMODE_PERSIST

  52730.       || (pPager->exclusiveMode && pPager->journalMode!=PAGER_JOURNALMODE_WAL)

  52731.     ){

  52732.       rc = zeroJournalHdr(pPager, hasMaster||pPager->tempFile);

  52733.       pPager->journalOff = 0;

  52734.     }else{

  52735.       /* This branch may be executed with Pager.journalMode==MEMORY if

  52736.       ** a hot-journal was just rolled back. In this case the journal

  52737.       ** file should be closed and deleted. If this connection writes to

  52738.       ** the database file, it will do so using an in-memory journal.

  52739.       */

  52740.       int bDelete = !pPager->tempFile;

  52741.       assert( sqlite3JournalIsInMemory(pPager->jfd)==0 );

  52742.       assert( pPager->journalMode==PAGER_JOURNALMODE_DELETE 

  52743.            || pPager->journalMode==PAGER_JOURNALMODE_MEMORY 

  52744.            || pPager->journalMode==PAGER_JOURNALMODE_WAL 

  52745.       );

  52746.       sqlite3OsClose(pPager->jfd);

  52747.       if( bDelete ){

  52748.         rc = sqlite3OsDelete(pPager->pVfs, pPager->zJournal, pPager->extraSync);

  52749.       }

  52750.     }

  52751.   }

  52752. 

  52753. #ifdef SQLITE_CHECK_PAGES

  52754.   sqlite3PcacheIterateDirty(pPager->pPCache, pager_set_pagehash);

  52755.   if( pPager->dbSize==0 && sqlite3PcacheRefCount(pPager->pPCache)>0 ){

  52756.     PgHdr *p = sqlite3PagerLookup(pPager, 1);

  52757.     if( p ){

  52758.       p->pageHash = 0;

  52759.       sqlite3PagerUnrefNotNull(p);

  52760.     }

  52761.   }

  52762. #endif

  52763. 

  52764.   sqlite3BitvecDestroy(pPager->pInJournal);

  52765.   pPager->pInJournal = 0;

  52766.   pPager->nRec = 0;

  52767.   if( rc==SQLITE_OK ){

  52768.     if( MEMDB || pagerFlushOnCommit(pPager, bCommit) ){

  52769.       sqlite3PcacheCleanAll(pPager->pPCache);

  52770.     }else{

  52771.       sqlite3PcacheClearWritable(pPager->pPCache);

  52772.     }

  52773.     sqlite3PcacheTruncate(pPager->pPCache, pPager->dbSize);

  52774.   }

  52775. 

  52776.   if( pagerUseWal(pPager) ){

  52777.     /* Drop the WAL write-lock, if any. Also, if the connection was in 

  52778.     ** locking_mode=exclusive mode but is no longer, drop the EXCLUSIVE 

  52779.     ** lock held on the database file.

  52780.     */

  52781.     rc2 = sqlite3WalEndWriteTransaction(pPager->pWal);

  52782.     assert( rc2==SQLITE_OK );

  52783.   }else if( rc==SQLITE_OK && bCommit && pPager->dbFileSize>pPager->dbSize ){

  52784.     /* This branch is taken when committing a transaction in rollback-journal

  52785.     ** mode if the database file on disk is larger than the database image.

  52786.     ** At this point the journal has been finalized and the transaction 

  52787.     ** successfully committed, but the EXCLUSIVE lock is still held on the

  52788.     ** file. So it is safe to truncate the database file to its minimum

  52789.     ** required size.  */

  52790.     assert( pPager->eLock==EXCLUSIVE_LOCK );

  52791.     rc = pager_truncate(pPager, pPager->dbSize);

  52792.   }

  52793. 

  52794.   if( rc==SQLITE_OK && bCommit ){

  52795.     rc = sqlite3OsFileControl(pPager->fd, SQLITE_FCNTL_COMMIT_PHASETWO, 0);

  52796.     if( rc==SQLITE_NOTFOUND ) rc = SQLITE_OK;

  52797.   }

  52798. 

  52799.   if( !pPager->exclusiveMode 

  52800.    && (!pagerUseWal(pPager) || sqlite3WalExclusiveMode(pPager->pWal, 0))

  52801.   ){

  52802.     rc2 = pagerUnlockDb(pPager, SHARED_LOCK);

  52803.     pPager->changeCountDone = 0;

  52804.   }

  52805.   pPager->eState = PAGER_READER;

  52806.   pPager->setMaster = 0;

  52807. 

  52808.   return (rc==SQLITE_OK?rc2:rc);

  52809. }

  52810. 

  52811. /*

  52812. ** Execute a rollback if a transaction is active and unlock the 

  52813. ** database file. 

  52814. **

  52815. ** If the pager has already entered the ERROR state, do not attempt 

  52816. ** the rollback at this time. Instead, pager_unlock() is called. The

  52817. ** call to pager_unlock() will discard all in-memory pages, unlock

  52818. ** the database file and move the pager back to OPEN state. If this 

  52819. ** means that there is a hot-journal left in the file-system, the next 

  52820. ** connection to obtain a shared lock on the pager (which may be this one) 

  52821. ** will roll it back.

  52822. **

  52823. ** If the pager has not already entered the ERROR state, but an IO or

  52824. ** malloc error occurs during a rollback, then this will itself cause 

  52825. ** the pager to enter the ERROR state. Which will be cleared by the

  52826. ** call to pager_unlock(), as described above.

  52827. */

  52828. static void pagerUnlockAndRollback(Pager *pPager){

  52829.   if( pPager->eState!=PAGER_ERROR && pPager->eState!=PAGER_OPEN ){

  52830.     assert( assert_pager_state(pPager) );

  52831.     if( pPager->eState>=PAGER_WRITER_LOCKED ){

  52832.       sqlite3BeginBenignMalloc();

  52833.       sqlite3PagerRollback(pPager);

  52834.       sqlite3EndBenignMalloc();

  52835.     }else if( !pPager->exclusiveMode ){

  52836.       assert( pPager->eState==PAGER_READER );

  52837.       pager_end_transaction(pPager, 0, 0);

  52838.     }

  52839.   }

  52840.   pager_unlock(pPager);

  52841. }

  52842. 

  52843. /*

  52844. ** Parameter aData must point to a buffer of pPager->pageSize bytes

  52845. ** of data. Compute and return a checksum based ont the contents of the 

  52846. ** page of data and the current value of pPager->cksumInit.

  52847. **

  52848. ** This is not a real checksum. It is really just the sum of the 

  52849. ** random initial value (pPager->cksumInit) and every 200th byte

  52850. ** of the page data, starting with byte offset (pPager->pageSize%200).

  52851. ** Each byte is interpreted as an 8-bit unsigned integer.

  52852. **

  52853. ** Changing the formula used to compute this checksum results in an

  52854. ** incompatible journal file format.

  52855. **

  52856. ** If journal corruption occurs due to a power failure, the most likely 

  52857. ** scenario is that one end or the other of the record will be changed. 

  52858. ** It is much less likely that the two ends of the journal record will be

  52859. ** correct and the middle be corrupt.  Thus, this "checksum" scheme,

  52860. ** though fast and simple, catches the mostly likely kind of corruption.

  52861. */

  52862. static u32 pager_cksum(Pager *pPager, const u8 *aData){

  52863.   u32 cksum = pPager->cksumInit;         /* Checksum value to return */

  52864.   int i = pPager->pageSize-200;          /* Loop counter */

  52865.   while( i>0 ){

  52866.     cksum += aData[i];

  52867.     i -= 200;

  52868.   }

  52869.   return cksum;

  52870. }

  52871. 

  52872. /*

  52873. ** Report the current page size and number of reserved bytes back

  52874. ** to the codec.

  52875. */

  52876. #ifdef SQLITE_HAS_CODEC

  52877. static void pagerReportSize(Pager *pPager){

  52878.   if( pPager->xCodecSizeChng ){

  52879.     pPager->xCodecSizeChng(pPager->pCodec, pPager->pageSize,

  52880.                            (int)pPager->nReserve);

  52881.   }

  52882. }

  52883. #else

  52884. # define pagerReportSize(X)     /* No-op if we do not support a codec */

  52885. #endif

  52886. 

  52887. #ifdef SQLITE_HAS_CODEC

  52888. /*

  52889. ** Make sure the number of reserved bits is the same in the destination

  52890. ** pager as it is in the source.  This comes up when a VACUUM changes the

  52891. ** number of reserved bits to the "optimal" amount.

  52892. */

  52893. SQLITE_PRIVATE void sqlite3PagerAlignReserve(Pager *pDest, Pager *pSrc){

  52894.   if( pDest->nReserve!=pSrc->nReserve ){

  52895.     pDest->nReserve = pSrc->nReserve;

  52896.     pagerReportSize(pDest);

  52897.   }

  52898. }

  52899. #endif

  52900. 

  52901. /*

  52902. ** Read a single page from either the journal file (if isMainJrnl==1) or

  52903. ** from the sub-journal (if isMainJrnl==0) and playback that page.

  52904. ** The page begins at offset *pOffset into the file. The *pOffset

  52905. ** value is increased to the start of the next page in the journal.

  52906. **

  52907. ** The main rollback journal uses checksums - the statement journal does 

  52908. ** not.

  52909. **

  52910. ** If the page number of the page record read from the (sub-)journal file

  52911. ** is greater than the current value of Pager.dbSize, then playback is

  52912. ** skipped and SQLITE_OK is returned.

  52913. **

  52914. ** If pDone is not NULL, then it is a record of pages that have already

  52915. ** been played back.  If the page at *pOffset has already been played back

  52916. ** (if the corresponding pDone bit is set) then skip the playback.

  52917. ** Make sure the pDone bit corresponding to the *pOffset page is set

  52918. ** prior to returning.

  52919. **

  52920. ** If the page record is successfully read from the (sub-)journal file

  52921. ** and played back, then SQLITE_OK is returned. If an IO error occurs

  52922. ** while reading the record from the (sub-)journal file or while writing

  52923. ** to the database file, then the IO error code is returned. If data

  52924. ** is successfully read from the (sub-)journal file but appears to be

  52925. ** corrupted, SQLITE_DONE is returned. Data is considered corrupted in

  52926. ** two circumstances:

  52927. ** 

  52928. **   * If the record page-number is illegal (0 or PAGER_MJ_PGNO), or

  52929. **   * If the record is being rolled back from the main journal file

  52930. **     and the checksum field does not match the record content.

  52931. **

  52932. ** Neither of these two scenarios are possible during a savepoint rollback.

  52933. **

  52934. ** If this is a savepoint rollback, then memory may have to be dynamically

  52935. ** allocated by this function. If this is the case and an allocation fails,

  52936. ** SQLITE_NOMEM is returned.

  52937. */

  52938. static int pager_playback_one_page(

  52939.   Pager *pPager,                /* The pager being played back */

  52940.   i64 *pOffset,                 /* Offset of record to playback */

  52941.   Bitvec *pDone,                /* Bitvec of pages already played back */

  52942.   int isMainJrnl,               /* 1 -> main journal. 0 -> sub-journal. */

  52943.   int isSavepnt                 /* True for a savepoint rollback */

  52944. ){

  52945.   int rc;

  52946.   PgHdr *pPg;                   /* An existing page in the cache */

  52947.   Pgno pgno;                    /* The page number of a page in journal */

  52948.   u32 cksum;                    /* Checksum used for sanity checking */

  52949.   char *aData;                  /* Temporary storage for the page */

  52950.   sqlite3_file *jfd;            /* The file descriptor for the journal file */

  52951.   int isSynced;                 /* True if journal page is synced */

  52952. #ifdef SQLITE_HAS_CODEC

  52953.   /* The jrnlEnc flag is true if Journal pages should be passed through

  52954.   ** the codec.  It is false for pure in-memory journals. */

  52955.   const int jrnlEnc = (isMainJrnl || pPager->subjInMemory==0);

  52956. #endif

  52957. 

  52958.   assert( (isMainJrnl&~1)==0 );      /* isMainJrnl is 0 or 1 */

  52959.   assert( (isSavepnt&~1)==0 );       /* isSavepnt is 0 or 1 */

  52960.   assert( isMainJrnl || pDone );     /* pDone always used on sub-journals */

  52961.   assert( isSavepnt || pDone==0 );   /* pDone never used on non-savepoint */

  52962. 

  52963.   aData = pPager->pTmpSpace;

  52964.   assert( aData );         /* Temp storage must have already been allocated */

  52965.   assert( pagerUseWal(pPager)==0 || (!isMainJrnl && isSavepnt) );

  52966. 

  52967.   /* Either the state is greater than PAGER_WRITER_CACHEMOD (a transaction 

  52968.   ** or savepoint rollback done at the request of the caller) or this is

  52969.   ** a hot-journal rollback. If it is a hot-journal rollback, the pager

  52970.   ** is in state OPEN and holds an EXCLUSIVE lock. Hot-journal rollback

  52971.   ** only reads from the main journal, not the sub-journal.

  52972.   */

  52973.   assert( pPager->eState>=PAGER_WRITER_CACHEMOD

  52974.        || (pPager->eState==PAGER_OPEN && pPager->eLock==EXCLUSIVE_LOCK)

  52975.   );

  52976.   assert( pPager->eState>=PAGER_WRITER_CACHEMOD || isMainJrnl );

  52977. 

  52978.   /* Read the page number and page data from the journal or sub-journal

  52979.   ** file. Return an error code to the caller if an IO error occurs.

  52980.   */

  52981.   jfd = isMainJrnl ? pPager->jfd : pPager->sjfd;

  52982.   rc = read32bits(jfd, *pOffset, &pgno);

  52983.   if( rc!=SQLITE_OK ) return rc;

  52984.   rc = sqlite3OsRead(jfd, (u8*)aData, pPager->pageSize, (*pOffset)+4);

  52985.   if( rc!=SQLITE_OK ) return rc;

  52986.   *pOffset += pPager->pageSize + 4 + isMainJrnl*4;

  52987. 

  52988.   /* Sanity checking on the page.  This is more important that I originally

  52989.   ** thought.  If a power failure occurs while the journal is being written,

  52990.   ** it could cause invalid data to be written into the journal.  We need to

  52991.   ** detect this invalid data (with high probability) and ignore it.

  52992.   */

  52993.   if( pgno==0 || pgno==PAGER_MJ_PGNO(pPager) ){

  52994.     assert( !isSavepnt );

  52995.     return SQLITE_DONE;

  52996.   }

  52997.   if( pgno>(Pgno)pPager->dbSize || sqlite3BitvecTest(pDone, pgno) ){

  52998.     return SQLITE_OK;

  52999.   }

  53000.   if( isMainJrnl ){

  53001.     rc = read32bits(jfd, (*pOffset)-4, &cksum);

  53002.     if( rc ) return rc;

  53003.     if( !isSavepnt && pager_cksum(pPager, (u8*)aData)!=cksum ){

  53004.       return SQLITE_DONE;

  53005.     }

  53006.   }

  53007. 

  53008.   /* If this page has already been played back before during the current

  53009.   ** rollback, then don't bother to play it back again.

  53010.   */

  53011.   if( pDone && (rc = sqlite3BitvecSet(pDone, pgno))!=SQLITE_OK ){

  53012.     return rc;

  53013.   }

  53014. 

  53015.   /* When playing back page 1, restore the nReserve setting

  53016.   */

  53017.   if( pgno==1 && pPager->nReserve!=((u8*)aData)[20] ){

  53018.     pPager->nReserve = ((u8*)aData)[20];

  53019.     pagerReportSize(pPager);

  53020.   }

  53021. 

  53022.   /* If the pager is in CACHEMOD state, then there must be a copy of this

  53023.   ** page in the pager cache. In this case just update the pager cache,

  53024.   ** not the database file. The page is left marked dirty in this case.

  53025.   **

  53026.   ** An exception to the above rule: If the database is in no-sync mode

  53027.   ** and a page is moved during an incremental vacuum then the page may

  53028.   ** not be in the pager cache. Later: if a malloc() or IO error occurs

  53029.   ** during a Movepage() call, then the page may not be in the cache

  53030.   ** either. So the condition described in the above paragraph is not

  53031.   ** assert()able.

  53032.   **

  53033.   ** If in WRITER_DBMOD, WRITER_FINISHED or OPEN state, then we update the

  53034.   ** pager cache if it exists and the main file. The page is then marked 

  53035.   ** not dirty. Since this code is only executed in PAGER_OPEN state for

  53036.   ** a hot-journal rollback, it is guaranteed that the page-cache is empty

  53037.   ** if the pager is in OPEN state.

  53038.   **

  53039.   ** Ticket #1171:  The statement journal might contain page content that is

  53040.   ** different from the page content at the start of the transaction.

  53041.   ** This occurs when a page is changed prior to the start of a statement

  53042.   ** then changed again within the statement.  When rolling back such a

  53043.   ** statement we must not write to the original database unless we know

  53044.   ** for certain that original page contents are synced into the main rollback

  53045.   ** journal.  Otherwise, a power loss might leave modified data in the

  53046.   ** database file without an entry in the rollback journal that can

  53047.   ** restore the database to its original form.  Two conditions must be

  53048.   ** met before writing to the database files. (1) the database must be

  53049.   ** locked.  (2) we know that the original page content is fully synced

  53050.   ** in the main journal either because the page is not in cache or else

  53051.   ** the page is marked as needSync==0.

  53052.   **

  53053.   ** 2008-04-14:  When attempting to vacuum a corrupt database file, it

  53054.   ** is possible to fail a statement on a database that does not yet exist.

  53055.   ** Do not attempt to write if database file has never been opened.

  53056.   */

  53057.   if( pagerUseWal(pPager) ){

  53058.     pPg = 0;

  53059.   }else{

  53060.     pPg = sqlite3PagerLookup(pPager, pgno);

  53061.   }

  53062.   assert( pPg || !MEMDB );

  53063.   assert( pPager->eState!=PAGER_OPEN || pPg==0 || pPager->tempFile );

  53064.   PAGERTRACE(("PLAYBACK %d page %d hash(%08x) %s\n",

  53065.            PAGERID(pPager), pgno, pager_datahash(pPager->pageSize, (u8*)aData),

  53066.            (isMainJrnl?"main-journal":"sub-journal")

  53067.   ));

  53068.   if( isMainJrnl ){

  53069.     isSynced = pPager->noSync || (*pOffset <= pPager->journalHdr);

  53070.   }else{

  53071.     isSynced = (pPg==0 || 0==(pPg->flags & PGHDR_NEED_SYNC));

  53072.   }

  53073.   if( isOpen(pPager->fd)

  53074.    && (pPager->eState>=PAGER_WRITER_DBMOD || pPager->eState==PAGER_OPEN)

  53075.    && isSynced

  53076.   ){

  53077.     i64 ofst = (pgno-1)*(i64)pPager->pageSize;

  53078.     testcase( !isSavepnt && pPg!=0 && (pPg->flags&PGHDR_NEED_SYNC)!=0 );

  53079.     assert( !pagerUseWal(pPager) );

  53080. 

  53081.     /* Write the data read from the journal back into the database file.

  53082.     ** This is usually safe even for an encrypted database - as the data

  53083.     ** was encrypted before it was written to the journal file. The exception

  53084.     ** is if the data was just read from an in-memory sub-journal. In that

  53085.     ** case it must be encrypted here before it is copied into the database

  53086.     ** file.  */

  53087. #ifdef SQLITE_HAS_CODEC

  53088.     if( !jrnlEnc ){

  53089.       CODEC2(pPager, aData, pgno, 7, rc=SQLITE_NOMEM_BKPT, aData);

  53090.       rc = sqlite3OsWrite(pPager->fd, (u8 *)aData, pPager->pageSize, ofst);

  53091.       CODEC1(pPager, aData, pgno, 3, rc=SQLITE_NOMEM_BKPT);

  53092.     }else

  53093. #endif

  53094.     rc = sqlite3OsWrite(pPager->fd, (u8 *)aData, pPager->pageSize, ofst);

  53095. 

  53096.     if( pgno>pPager->dbFileSize ){

  53097.       pPager->dbFileSize = pgno;

  53098.     }

  53099.     if( pPager->pBackup ){

  53100. #ifdef SQLITE_HAS_CODEC

  53101.       if( jrnlEnc ){

  53102.         CODEC1(pPager, aData, pgno, 3, rc=SQLITE_NOMEM_BKPT);

  53103.         sqlite3BackupUpdate(pPager->pBackup, pgno, (u8*)aData);

  53104.         CODEC2(pPager, aData, pgno, 7, rc=SQLITE_NOMEM_BKPT,aData);

  53105.       }else

  53106. #endif

  53107.       sqlite3BackupUpdate(pPager->pBackup, pgno, (u8*)aData);

  53108.     }

  53109.   }else if( !isMainJrnl && pPg==0 ){

  53110.     /* If this is a rollback of a savepoint and data was not written to

  53111.     ** the database and the page is not in-memory, there is a potential

  53112.     ** problem. When the page is next fetched by the b-tree layer, it 

  53113.     ** will be read from the database file, which may or may not be 

  53114.     ** current. 

  53115.     **

  53116.     ** There are a couple of different ways this can happen. All are quite

  53117.     ** obscure. When running in synchronous mode, this can only happen 

  53118.     ** if the page is on the free-list at the start of the transaction, then

  53119.     ** populated, then moved using sqlite3PagerMovepage().

  53120.     **

  53121.     ** The solution is to add an in-memory page to the cache containing

  53122.     ** the data just read from the sub-journal. Mark the page as dirty 

  53123.     ** and if the pager requires a journal-sync, then mark the page as 

  53124.     ** requiring a journal-sync before it is written.

  53125.     */

  53126.     assert( isSavepnt );

  53127.     assert( (pPager->doNotSpill & SPILLFLAG_ROLLBACK)==0 );

  53128.     pPager->doNotSpill |= SPILLFLAG_ROLLBACK;

  53129.     rc = sqlite3PagerGet(pPager, pgno, &pPg, 1);

  53130.     assert( (pPager->doNotSpill & SPILLFLAG_ROLLBACK)!=0 );

  53131.     pPager->doNotSpill &= ~SPILLFLAG_ROLLBACK;

  53132.     if( rc!=SQLITE_OK ) return rc;

  53133.     sqlite3PcacheMakeDirty(pPg);

  53134.   }

  53135.   if( pPg ){

  53136.     /* No page should ever be explicitly rolled back that is in use, except

  53137.     ** for page 1 which is held in use in order to keep the lock on the

  53138.     ** database active. However such a page may be rolled back as a result

  53139.     ** of an internal error resulting in an automatic call to

  53140.     ** sqlite3PagerRollback().

  53141.     */

  53142.     void *pData;

  53143.     pData = pPg->pData;

  53144.     memcpy(pData, (u8*)aData, pPager->pageSize);

  53145.     pPager->xReiniter(pPg);

  53146.     /* It used to be that sqlite3PcacheMakeClean(pPg) was called here.  But

  53147.     ** that call was dangerous and had no detectable benefit since the cache

  53148.     ** is normally cleaned by sqlite3PcacheCleanAll() after rollback and so

  53149.     ** has been removed. */

  53150.     pager_set_pagehash(pPg);

  53151. 

  53152.     /* If this was page 1, then restore the value of Pager.dbFileVers.

  53153.     ** Do this before any decoding. */

  53154.     if( pgno==1 ){

  53155.       memcpy(&pPager->dbFileVers, &((u8*)pData)[24],sizeof(pPager->dbFileVers));

  53156.     }

  53157. 

  53158.     /* Decode the page just read from disk */

  53159. #if SQLITE_HAS_CODEC

  53160.     if( jrnlEnc ){ CODEC1(pPager, pData, pPg->pgno, 3, rc=SQLITE_NOMEM_BKPT); }

  53161. #endif

  53162.     sqlite3PcacheRelease(pPg);

  53163.   }

  53164.   return rc;

  53165. }

  53166. 

  53167. /*

  53168. ** Parameter zMaster is the name of a master journal file. A single journal

  53169. ** file that referred to the master journal file has just been rolled back.

  53170. ** This routine checks if it is possible to delete the master journal file,

  53171. ** and does so if it is.

  53172. **

  53173. ** Argument zMaster may point to Pager.pTmpSpace. So that buffer is not 

  53174. ** available for use within this function.

  53175. **

  53176. ** When a master journal file is created, it is populated with the names 

  53177. ** of all of its child journals, one after another, formatted as utf-8 

  53178. ** encoded text. The end of each child journal file is marked with a 

  53179. ** nul-terminator byte (0x00). i.e. the entire contents of a master journal

  53180. ** file for a transaction involving two databases might be:

  53181. **

  53182. **   "/home/bill/a.db-journal\x00/home/bill/b.db-journal\x00"

  53183. **

  53184. ** A master journal file may only be deleted once all of its child 

  53185. ** journals have been rolled back.

  53186. **

  53187. ** This function reads the contents of the master-journal file into 

  53188. ** memory and loops through each of the child journal names. For

  53189. ** each child journal, it checks if:

  53190. **

  53191. **   * if the child journal exists, and if so

  53192. **   * if the child journal contains a reference to master journal 

  53193. **     file zMaster

  53194. **

  53195. ** If a child journal can be found that matches both of the criteria

  53196. ** above, this function returns without doing anything. Otherwise, if

  53197. ** no such child journal can be found, file zMaster is deleted from

  53198. ** the file-system using sqlite3OsDelete().

  53199. **

  53200. ** If an IO error within this function, an error code is returned. This

  53201. ** function allocates memory by calling sqlite3Malloc(). If an allocation

  53202. ** fails, SQLITE_NOMEM is returned. Otherwise, if no IO or malloc errors 

  53203. ** occur, SQLITE_OK is returned.

  53204. **

  53205. ** TODO: This function allocates a single block of memory to load

  53206. ** the entire contents of the master journal file. This could be

  53207. ** a couple of kilobytes or so - potentially larger than the page 

  53208. ** size.

  53209. */

  53210. static int pager_delmaster(Pager *pPager, const char *zMaster){

  53211.   sqlite3_vfs *pVfs = pPager->pVfs;

  53212.   int rc;                   /* Return code */

  53213.   sqlite3_file *pMaster;    /* Malloc'd master-journal file descriptor */

  53214.   sqlite3_file *pJournal;   /* Malloc'd child-journal file descriptor */

  53215.   char *zMasterJournal = 0; /* Contents of master journal file */

  53216.   i64 nMasterJournal;       /* Size of master journal file */

  53217.   char *zJournal;           /* Pointer to one journal within MJ file */

  53218.   char *zMasterPtr;         /* Space to hold MJ filename from a journal file */

  53219.   int nMasterPtr;           /* Amount of space allocated to zMasterPtr[] */

  53220. 

  53221.   /* Allocate space for both the pJournal and pMaster file descriptors.

  53222.   ** If successful, open the master journal file for reading.

  53223.   */

  53224.   pMaster = (sqlite3_file *)sqlite3MallocZero(pVfs->szOsFile * 2);

  53225.   pJournal = (sqlite3_file *)(((u8 *)pMaster) + pVfs->szOsFile);

  53226.   if( !pMaster ){

  53227.     rc = SQLITE_NOMEM_BKPT;

  53228.   }else{

  53229.     const int flags = (SQLITE_OPEN_READONLY|SQLITE_OPEN_MASTER_JOURNAL);

  53230.     rc = sqlite3OsOpen(pVfs, zMaster, pMaster, flags, 0);

  53231.   }

  53232.   if( rc!=SQLITE_OK ) goto delmaster_out;

  53233. 

  53234.   /* Load the entire master journal file into space obtained from

  53235.   ** sqlite3_malloc() and pointed to by zMasterJournal.   Also obtain

  53236.   ** sufficient space (in zMasterPtr) to hold the names of master

  53237.   ** journal files extracted from regular rollback-journals.

  53238.   */

  53239.   rc = sqlite3OsFileSize(pMaster, &nMasterJournal);

  53240.   if( rc!=SQLITE_OK ) goto delmaster_out;

  53241.   nMasterPtr = pVfs->mxPathname+1;

  53242.   zMasterJournal = sqlite3Malloc(nMasterJournal + nMasterPtr + 1);

  53243.   if( !zMasterJournal ){

  53244.     rc = SQLITE_NOMEM_BKPT;

  53245.     goto delmaster_out;

  53246.   }

  53247.   zMasterPtr = &zMasterJournal[nMasterJournal+1];

  53248.   rc = sqlite3OsRead(pMaster, zMasterJournal, (int)nMasterJournal, 0);

  53249.   if( rc!=SQLITE_OK ) goto delmaster_out;

  53250.   zMasterJournal[nMasterJournal] = 0;

  53251. 

  53252.   zJournal = zMasterJournal;

  53253.   while( (zJournal-zMasterJournal)<nMasterJournal ){

  53254.     int exists;

  53255.     rc = sqlite3OsAccess(pVfs, zJournal, SQLITE_ACCESS_EXISTS, &exists);

  53256.     if( rc!=SQLITE_OK ){

  53257.       goto delmaster_out;

  53258.     }

  53259.     if( exists ){

  53260.       /* One of the journals pointed to by the master journal exists.

  53261.       ** Open it and check if it points at the master journal. If

  53262.       ** so, return without deleting the master journal file.

  53263.       */

  53264.       int c;

  53265.       int flags = (SQLITE_OPEN_READONLY|SQLITE_OPEN_MAIN_JOURNAL);

  53266.       rc = sqlite3OsOpen(pVfs, zJournal, pJournal, flags, 0);

  53267.       if( rc!=SQLITE_OK ){

  53268.         goto delmaster_out;

  53269.       }

  53270. 

  53271.       rc = readMasterJournal(pJournal, zMasterPtr, nMasterPtr);

  53272.       sqlite3OsClose(pJournal);

  53273.       if( rc!=SQLITE_OK ){

  53274.         goto delmaster_out;

  53275.       }

  53276. 

  53277.       c = zMasterPtr[0]!=0 && strcmp(zMasterPtr, zMaster)==0;

  53278.       if( c ){

  53279.         /* We have a match. Do not delete the master journal file. */

  53280.         goto delmaster_out;

  53281.       }

  53282.     }

  53283.     zJournal += (sqlite3Strlen30(zJournal)+1);

  53284.   }

  53285.  

  53286.   sqlite3OsClose(pMaster);

  53287.   rc = sqlite3OsDelete(pVfs, zMaster, 0);

  53288. 

  53289. delmaster_out:

  53290.   sqlite3_free(zMasterJournal);

  53291.   if( pMaster ){

  53292.     sqlite3OsClose(pMaster);

  53293.     assert( !isOpen(pJournal) );

  53294.     sqlite3_free(pMaster);

  53295.   }

  53296.   return rc;

  53297. }

  53298. 

  53299. 

  53300. /*

  53301. ** This function is used to change the actual size of the database 

  53302. ** file in the file-system. This only happens when committing a transaction,

  53303. ** or rolling back a transaction (including rolling back a hot-journal).

  53304. **

  53305. ** If the main database file is not open, or the pager is not in either

  53306. ** DBMOD or OPEN state, this function is a no-op. Otherwise, the size 

  53307. ** of the file is changed to nPage pages (nPage*pPager->pageSize bytes). 

  53308. ** If the file on disk is currently larger than nPage pages, then use the VFS

  53309. ** xTruncate() method to truncate it.

  53310. **

  53311. ** Or, it might be the case that the file on disk is smaller than 

  53312. ** nPage pages. Some operating system implementations can get confused if 

  53313. ** you try to truncate a file to some size that is larger than it 

  53314. ** currently is, so detect this case and write a single zero byte to 

  53315. ** the end of the new file instead.

  53316. **

  53317. ** If successful, return SQLITE_OK. If an IO error occurs while modifying

  53318. ** the database file, return the error code to the caller.

  53319. */

  53320. static int pager_truncate(Pager *pPager, Pgno nPage){

  53321.   int rc = SQLITE_OK;

  53322.   assert( pPager->eState!=PAGER_ERROR );

  53323.   assert( pPager->eState!=PAGER_READER );

  53324.   

  53325.   if( isOpen(pPager->fd) 

  53326.    && (pPager->eState>=PAGER_WRITER_DBMOD || pPager->eState==PAGER_OPEN) 

  53327.   ){

  53328.     i64 currentSize, newSize;

  53329.     int szPage = pPager->pageSize;

  53330.     assert( pPager->eLock==EXCLUSIVE_LOCK );

  53331.     /* TODO: Is it safe to use Pager.dbFileSize here? */

  53332.     rc = sqlite3OsFileSize(pPager->fd, &currentSize);

  53333.     newSize = szPage*(i64)nPage;

  53334.     if( rc==SQLITE_OK && currentSize!=newSize ){

  53335.       if( currentSize>newSize ){

  53336.         rc = sqlite3OsTruncate(pPager->fd, newSize);

  53337.       }else if( (currentSize+szPage)<=newSize ){

  53338.         char *pTmp = pPager->pTmpSpace;

  53339.         memset(pTmp, 0, szPage);

  53340.         testcase( (newSize-szPage) == currentSize );

  53341.         testcase( (newSize-szPage) >  currentSize );

  53342.         rc = sqlite3OsWrite(pPager->fd, pTmp, szPage, newSize-szPage);

  53343.       }

  53344.       if( rc==SQLITE_OK ){

  53345.         pPager->dbFileSize = nPage;

  53346.       }

  53347.     }

  53348.   }

  53349.   return rc;

  53350. }

  53351. 

  53352. /*

  53353. ** Return a sanitized version of the sector-size of OS file pFile. The

  53354. ** return value is guaranteed to lie between 32 and MAX_SECTOR_SIZE.

  53355. */

  53356. SQLITE_PRIVATE int sqlite3SectorSize(sqlite3_file *pFile){

  53357.   int iRet = sqlite3OsSectorSize(pFile);

  53358.   if( iRet<32 ){

  53359.     iRet = 512;

  53360.   }else if( iRet>MAX_SECTOR_SIZE ){

  53361.     assert( MAX_SECTOR_SIZE>=512 );

  53362.     iRet = MAX_SECTOR_SIZE;

  53363.   }

  53364.   return iRet;

  53365. }

  53366. 

  53367. /*

  53368. ** Set the value of the Pager.sectorSize variable for the given

  53369. ** pager based on the value returned by the xSectorSize method

  53370. ** of the open database file. The sector size will be used 

  53371. ** to determine the size and alignment of journal header and 

  53372. ** master journal pointers within created journal files.

  53373. **

  53374. ** For temporary files the effective sector size is always 512 bytes.

  53375. **

  53376. ** Otherwise, for non-temporary files, the effective sector size is

  53377. ** the value returned by the xSectorSize() method rounded up to 32 if

  53378. ** it is less than 32, or rounded down to MAX_SECTOR_SIZE if it

  53379. ** is greater than MAX_SECTOR_SIZE.

  53380. **

  53381. ** If the file has the SQLITE_IOCAP_POWERSAFE_OVERWRITE property, then set

  53382. ** the effective sector size to its minimum value (512).  The purpose of

  53383. ** pPager->sectorSize is to define the "blast radius" of bytes that

  53384. ** might change if a crash occurs while writing to a single byte in

  53385. ** that range.  But with POWERSAFE_OVERWRITE, the blast radius is zero

  53386. ** (that is what POWERSAFE_OVERWRITE means), so we minimize the sector

  53387. ** size.  For backwards compatibility of the rollback journal file format,

  53388. ** we cannot reduce the effective sector size below 512.

  53389. */

  53390. static void setSectorSize(Pager *pPager){

  53391.   assert( isOpen(pPager->fd) || pPager->tempFile );

  53392. 

  53393.   if( pPager->tempFile

  53394.    || (sqlite3OsDeviceCharacteristics(pPager->fd) & 

  53395.               SQLITE_IOCAP_POWERSAFE_OVERWRITE)!=0

  53396.   ){

  53397.     /* Sector size doesn't matter for temporary files. Also, the file

  53398.     ** may not have been opened yet, in which case the OsSectorSize()

  53399.     ** call will segfault. */

  53400.     pPager->sectorSize = 512;

  53401.   }else{

  53402.     pPager->sectorSize = sqlite3SectorSize(pPager->fd);

  53403.   }

  53404. }

  53405. 

  53406. /*

  53407. ** Playback the journal and thus restore the database file to

  53408. ** the state it was in before we started making changes.  

  53409. **

  53410. ** The journal file format is as follows: 

  53411. **

  53412. **  (1)  8 byte prefix.  A copy of aJournalMagic[].

  53413. **  (2)  4 byte big-endian integer which is the number of valid page records

  53414. **       in the journal.  If this value is 0xffffffff, then compute the

  53415. **       number of page records from the journal size.

  53416. **  (3)  4 byte big-endian integer which is the initial value for the 

  53417. **       sanity checksum.

  53418. **  (4)  4 byte integer which is the number of pages to truncate the

  53419. **       database to during a rollback.

  53420. **  (5)  4 byte big-endian integer which is the sector size.  The header

  53421. **       is this many bytes in size.

  53422. **  (6)  4 byte big-endian integer which is the page size.

  53423. **  (7)  zero padding out to the next sector size.

  53424. **  (8)  Zero or more pages instances, each as follows:

  53425. **        +  4 byte page number.

  53426. **        +  pPager->pageSize bytes of data.

  53427. **        +  4 byte checksum

  53428. **

  53429. ** When we speak of the journal header, we mean the first 7 items above.

  53430. ** Each entry in the journal is an instance of the 8th item.

  53431. **

  53432. ** Call the value from the second bullet "nRec".  nRec is the number of

  53433. ** valid page entries in the journal.  In most cases, you can compute the

  53434. ** value of nRec from the size of the journal file.  But if a power

  53435. ** failure occurred while the journal was being written, it could be the

  53436. ** case that the size of the journal file had already been increased but

  53437. ** the extra entries had not yet made it safely to disk.  In such a case,

  53438. ** the value of nRec computed from the file size would be too large.  For

  53439. ** that reason, we always use the nRec value in the header.

  53440. **

  53441. ** If the nRec value is 0xffffffff it means that nRec should be computed

  53442. ** from the file size.  This value is used when the user selects the

  53443. ** no-sync option for the journal.  A power failure could lead to corruption

  53444. ** in this case.  But for things like temporary table (which will be

  53445. ** deleted when the power is restored) we don't care.  

  53446. **

  53447. ** If the file opened as the journal file is not a well-formed

  53448. ** journal file then all pages up to the first corrupted page are rolled

  53449. ** back (or no pages if the journal header is corrupted). The journal file

  53450. ** is then deleted and SQLITE_OK returned, just as if no corruption had

  53451. ** been encountered.

  53452. **

  53453. ** If an I/O or malloc() error occurs, the journal-file is not deleted

  53454. ** and an error code is returned.

  53455. **

  53456. ** The isHot parameter indicates that we are trying to rollback a journal

  53457. ** that might be a hot journal.  Or, it could be that the journal is 

  53458. ** preserved because of JOURNALMODE_PERSIST or JOURNALMODE_TRUNCATE.

  53459. ** If the journal really is hot, reset the pager cache prior rolling

  53460. ** back any content.  If the journal is merely persistent, no reset is

  53461. ** needed.

  53462. */

  53463. static int pager_playback(Pager *pPager, int isHot){

  53464.   sqlite3_vfs *pVfs = pPager->pVfs;

  53465.   i64 szJ;                 /* Size of the journal file in bytes */

  53466.   u32 nRec;                /* Number of Records in the journal */

  53467.   u32 u;                   /* Unsigned loop counter */

  53468.   Pgno mxPg = 0;           /* Size of the original file in pages */

  53469.   int rc;                  /* Result code of a subroutine */

  53470.   int res = 1;             /* Value returned by sqlite3OsAccess() */

  53471.   char *zMaster = 0;       /* Name of master journal file if any */

  53472.   int needPagerReset;      /* True to reset page prior to first page rollback */

  53473.   int nPlayback = 0;       /* Total number of pages restored from journal */

  53474.   u32 savedPageSize = pPager->pageSize;

  53475. 

  53476.   /* Figure out how many records are in the journal.  Abort early if

  53477.   ** the journal is empty.

  53478.   */

  53479.   assert( isOpen(pPager->jfd) );

  53480.   rc = sqlite3OsFileSize(pPager->jfd, &szJ);

  53481.   if( rc!=SQLITE_OK ){

  53482.     goto end_playback;

  53483.   }

  53484. 

  53485.   /* Read the master journal name from the journal, if it is present.

  53486.   ** If a master journal file name is specified, but the file is not

  53487.   ** present on disk, then the journal is not hot and does not need to be

  53488.   ** played back.

  53489.   **

  53490.   ** TODO: Technically the following is an error because it assumes that

  53491.   ** buffer Pager.pTmpSpace is (mxPathname+1) bytes or larger. i.e. that

  53492.   ** (pPager->pageSize >= pPager->pVfs->mxPathname+1). Using os_unix.c,

  53493.   ** mxPathname is 512, which is the same as the minimum allowable value

  53494.   ** for pageSize.

  53495.   */

  53496.   zMaster = pPager->pTmpSpace;

  53497.   rc = readMasterJournal(pPager->jfd, zMaster, pPager->pVfs->mxPathname+1);

  53498.   if( rc==SQLITE_OK && zMaster[0] ){

  53499.     rc = sqlite3OsAccess(pVfs, zMaster, SQLITE_ACCESS_EXISTS, &res);

  53500.   }

  53501.   zMaster = 0;

  53502.   if( rc!=SQLITE_OK || !res ){

  53503.     goto end_playback;

  53504.   }

  53505.   pPager->journalOff = 0;

  53506.   needPagerReset = isHot;

  53507. 

  53508.   /* This loop terminates either when a readJournalHdr() or 

  53509.   ** pager_playback_one_page() call returns SQLITE_DONE or an IO error 

  53510.   ** occurs. 

  53511.   */

  53512.   while( 1 ){

  53513.     /* Read the next journal header from the journal file.  If there are

  53514.     ** not enough bytes left in the journal file for a complete header, or

  53515.     ** it is corrupted, then a process must have failed while writing it.

  53516.     ** This indicates nothing more needs to be rolled back.

  53517.     */

  53518.     rc = readJournalHdr(pPager, isHot, szJ, &nRec, &mxPg);

  53519.     if( rc!=SQLITE_OK ){ 

  53520.       if( rc==SQLITE_DONE ){

  53521.         rc = SQLITE_OK;

  53522.       }

  53523.       goto end_playback;

  53524.     }

  53525. 

  53526.     /* If nRec is 0xffffffff, then this journal was created by a process

  53527.     ** working in no-sync mode. This means that the rest of the journal

  53528.     ** file consists of pages, there are no more journal headers. Compute

  53529.     ** the value of nRec based on this assumption.

  53530.     */

  53531.     if( nRec==0xffffffff ){

  53532.       assert( pPager->journalOff==JOURNAL_HDR_SZ(pPager) );

  53533.       nRec = (int)((szJ - JOURNAL_HDR_SZ(pPager))/JOURNAL_PG_SZ(pPager));

  53534.     }

  53535. 

  53536.     /* If nRec is 0 and this rollback is of a transaction created by this

  53537.     ** process and if this is the final header in the journal, then it means

  53538.     ** that this part of the journal was being filled but has not yet been

  53539.     ** synced to disk.  Compute the number of pages based on the remaining

  53540.     ** size of the file.

  53541.     **

  53542.     ** The third term of the test was added to fix ticket #2565.

  53543.     ** When rolling back a hot journal, nRec==0 always means that the next

  53544.     ** chunk of the journal contains zero pages to be rolled back.  But

  53545.     ** when doing a ROLLBACK and the nRec==0 chunk is the last chunk in

  53546.     ** the journal, it means that the journal might contain additional

  53547.     ** pages that need to be rolled back and that the number of pages 

  53548.     ** should be computed based on the journal file size.

  53549.     */

  53550.     if( nRec==0 && !isHot &&

  53551.         pPager->journalHdr+JOURNAL_HDR_SZ(pPager)==pPager->journalOff ){

  53552.       nRec = (int)((szJ - pPager->journalOff) / JOURNAL_PG_SZ(pPager));

  53553.     }

  53554. 

  53555.     /* If this is the first header read from the journal, truncate the

  53556.     ** database file back to its original size.

  53557.     */

  53558.     if( pPager->journalOff==JOURNAL_HDR_SZ(pPager) ){

  53559.       rc = pager_truncate(pPager, mxPg);

  53560.       if( rc!=SQLITE_OK ){

  53561.         goto end_playback;

  53562.       }

  53563.       pPager->dbSize = mxPg;

  53564.     }

  53565. 

  53566.     /* Copy original pages out of the journal and back into the 

  53567.     ** database file and/or page cache.

  53568.     */

  53569.     for(u=0; u<nRec; u++){

  53570.       if( needPagerReset ){

  53571.         pager_reset(pPager);

  53572.         needPagerReset = 0;

  53573.       }

  53574.       rc = pager_playback_one_page(pPager,&pPager->journalOff,0,1,0);

  53575.       if( rc==SQLITE_OK ){

  53576.         nPlayback++;

  53577.       }else{

  53578.         if( rc==SQLITE_DONE ){

  53579.           pPager->journalOff = szJ;

  53580.           break;

  53581.         }else if( rc==SQLITE_IOERR_SHORT_READ ){

  53582.           /* If the journal has been truncated, simply stop reading and

  53583.           ** processing the journal. This might happen if the journal was

  53584.           ** not completely written and synced prior to a crash.  In that

  53585.           ** case, the database should have never been written in the

  53586.           ** first place so it is OK to simply abandon the rollback. */

  53587.           rc = SQLITE_OK;

  53588.           goto end_playback;

  53589.         }else{

  53590.           /* If we are unable to rollback, quit and return the error

  53591.           ** code.  This will cause the pager to enter the error state

  53592.           ** so that no further harm will be done.  Perhaps the next

  53593.           ** process to come along will be able to rollback the database.

  53594.           */

  53595.           goto end_playback;

  53596.         }

  53597.       }

  53598.     }

  53599.   }

  53600.   /*NOTREACHED*/

  53601.   assert( 0 );

  53602. 

  53603. end_playback:

  53604.   if( rc==SQLITE_OK ){

  53605.     rc = sqlite3PagerSetPagesize(pPager, &savedPageSize, -1);

  53606.   }

  53607.   /* Following a rollback, the database file should be back in its original

  53608.   ** state prior to the start of the transaction, so invoke the

  53609.   ** SQLITE_FCNTL_DB_UNCHANGED file-control method to disable the

  53610.   ** assertion that the transaction counter was modified.

  53611.   */

  53612. #ifdef SQLITE_DEBUG

  53613.   sqlite3OsFileControlHint(pPager->fd,SQLITE_FCNTL_DB_UNCHANGED,0);

  53614. #endif

  53615. 

  53616.   /* If this playback is happening automatically as a result of an IO or 

  53617.   ** malloc error that occurred after the change-counter was updated but 

  53618.   ** before the transaction was committed, then the change-counter 

  53619.   ** modification may just have been reverted. If this happens in exclusive 

  53620.   ** mode, then subsequent transactions performed by the connection will not

  53621.   ** update the change-counter at all. This may lead to cache inconsistency

  53622.   ** problems for other processes at some point in the future. So, just

  53623.   ** in case this has happened, clear the changeCountDone flag now.

  53624.   */

  53625.   pPager->changeCountDone = pPager->tempFile;

  53626. 

  53627.   if( rc==SQLITE_OK ){

  53628.     zMaster = pPager->pTmpSpace;

  53629.     rc = readMasterJournal(pPager->jfd, zMaster, pPager->pVfs->mxPathname+1);

  53630.     testcase( rc!=SQLITE_OK );

  53631.   }

  53632.   if( rc==SQLITE_OK

  53633.    && (pPager->eState>=PAGER_WRITER_DBMOD || pPager->eState==PAGER_OPEN)

  53634.   ){

  53635.     rc = sqlite3PagerSync(pPager, 0);

  53636.   }

  53637.   if( rc==SQLITE_OK ){

  53638.     rc = pager_end_transaction(pPager, zMaster[0]!='\0', 0);

  53639.     testcase( rc!=SQLITE_OK );

  53640.   }

  53641.   if( rc==SQLITE_OK && zMaster[0] && res ){

  53642.     /* If there was a master journal and this routine will return success,

  53643.     ** see if it is possible to delete the master journal.

  53644.     */

  53645.     rc = pager_delmaster(pPager, zMaster);

  53646.     testcase( rc!=SQLITE_OK );

  53647.   }

  53648.   if( isHot && nPlayback ){

  53649.     sqlite3_log(SQLITE_NOTICE_RECOVER_ROLLBACK, "recovered %d pages from %s",

  53650.                 nPlayback, pPager->zJournal);

  53651.   }

  53652. 

  53653.   /* The Pager.sectorSize variable may have been updated while rolling

  53654.   ** back a journal created by a process with a different sector size

  53655.   ** value. Reset it to the correct value for this process.

  53656.   */

  53657.   setSectorSize(pPager);

  53658.   return rc;

  53659. }

  53660. 

  53661. 

  53662. /*

  53663. ** Read the content for page pPg out of the database file (or out of

  53664. ** the WAL if that is where the most recent copy if found) into 

  53665. ** pPg->pData. A shared lock or greater must be held on the database

  53666. ** file before this function is called.

  53667. **

  53668. ** If page 1 is read, then the value of Pager.dbFileVers[] is set to

  53669. ** the value read from the database file.

  53670. **

  53671. ** If an IO error occurs, then the IO error is returned to the caller.

  53672. ** Otherwise, SQLITE_OK is returned.

  53673. */

  53674. static int readDbPage(PgHdr *pPg){

  53675.   Pager *pPager = pPg->pPager; /* Pager object associated with page pPg */

  53676.   int rc = SQLITE_OK;          /* Return code */

  53677. 

  53678. #ifndef SQLITE_OMIT_WAL

  53679.   u32 iFrame = 0;              /* Frame of WAL containing pgno */

  53680. 

  53681.   assert( pPager->eState>=PAGER_READER && !MEMDB );

  53682.   assert( isOpen(pPager->fd) );

  53683. 

  53684.   if( pagerUseWal(pPager) ){

  53685.     rc = sqlite3WalFindFrame(pPager->pWal, pPg->pgno, &iFrame);

  53686.     if( rc ) return rc;

  53687.   }

  53688.   if( iFrame ){

  53689.     rc = sqlite3WalReadFrame(pPager->pWal, iFrame,pPager->pageSize,pPg->pData);

  53690.   }else

  53691. #endif

  53692.   {

  53693.     i64 iOffset = (pPg->pgno-1)*(i64)pPager->pageSize;

  53694.     rc = sqlite3OsRead(pPager->fd, pPg->pData, pPager->pageSize, iOffset);

  53695.     if( rc==SQLITE_IOERR_SHORT_READ ){

  53696.       rc = SQLITE_OK;

  53697.     }

  53698.   }

  53699. 

  53700.   if( pPg->pgno==1 ){

  53701.     if( rc ){

  53702.       /* If the read is unsuccessful, set the dbFileVers[] to something

  53703.       ** that will never be a valid file version.  dbFileVers[] is a copy

  53704.       ** of bytes 24..39 of the database.  Bytes 28..31 should always be

  53705.       ** zero or the size of the database in page. Bytes 32..35 and 35..39

  53706.       ** should be page numbers which are never 0xffffffff.  So filling

  53707.       ** pPager->dbFileVers[] with all 0xff bytes should suffice.

  53708.       **

  53709.       ** For an encrypted database, the situation is more complex:  bytes

  53710.       ** 24..39 of the database are white noise.  But the probability of

  53711.       ** white noise equaling 16 bytes of 0xff is vanishingly small so

  53712.       ** we should still be ok.

  53713.       */

  53714.       memset(pPager->dbFileVers, 0xff, sizeof(pPager->dbFileVers));

  53715.     }else{

  53716.       u8 *dbFileVers = &((u8*)pPg->pData)[24];

  53717.       memcpy(&pPager->dbFileVers, dbFileVers, sizeof(pPager->dbFileVers));

  53718.     }

  53719.   }

  53720.   CODEC1(pPager, pPg->pData, pPg->pgno, 3, rc = SQLITE_NOMEM_BKPT);

  53721. 

  53722.   PAGER_INCR(sqlite3_pager_readdb_count);

  53723.   PAGER_INCR(pPager->nRead);

  53724.   IOTRACE(("PGIN %p %d\n", pPager, pPg->pgno));

  53725.   PAGERTRACE(("FETCH %d page %d hash(%08x)\n",

  53726.                PAGERID(pPager), pPg->pgno, pager_pagehash(pPg)));

  53727. 

  53728.   return rc;

  53729. }

  53730. 

  53731. /*

  53732. ** Update the value of the change-counter at offsets 24 and 92 in

  53733. ** the header and the sqlite version number at offset 96.

  53734. **

  53735. ** This is an unconditional update.  See also the pager_incr_changecounter()

  53736. ** routine which only updates the change-counter if the update is actually

  53737. ** needed, as determined by the pPager->changeCountDone state variable.

  53738. */

  53739. static void pager_write_changecounter(PgHdr *pPg){

  53740.   u32 change_counter;

  53741. 

  53742.   /* Increment the value just read and write it back to byte 24. */

  53743.   change_counter = sqlite3Get4byte((u8*)pPg->pPager->dbFileVers)+1;

  53744.   put32bits(((char*)pPg->pData)+24, change_counter);

  53745. 

  53746.   /* Also store the SQLite version number in bytes 96..99 and in

  53747.   ** bytes 92..95 store the change counter for which the version number

  53748.   ** is valid. */

  53749.   put32bits(((char*)pPg->pData)+92, change_counter);

  53750.   put32bits(((char*)pPg->pData)+96, SQLITE_VERSION_NUMBER);

  53751. }

  53752. 

  53753. #ifndef SQLITE_OMIT_WAL

  53754. /*

  53755. ** This function is invoked once for each page that has already been 

  53756. ** written into the log file when a WAL transaction is rolled back.

  53757. ** Parameter iPg is the page number of said page. The pCtx argument 

  53758. ** is actually a pointer to the Pager structure.

  53759. **

  53760. ** If page iPg is present in the cache, and has no outstanding references,

  53761. ** it is discarded. Otherwise, if there are one or more outstanding

  53762. ** references, the page content is reloaded from the database. If the

  53763. ** attempt to reload content from the database is required and fails, 

  53764. ** return an SQLite error code. Otherwise, SQLITE_OK.

  53765. */

  53766. static int pagerUndoCallback(void *pCtx, Pgno iPg){

  53767.   int rc = SQLITE_OK;

  53768.   Pager *pPager = (Pager *)pCtx;

  53769.   PgHdr *pPg;

  53770. 

  53771.   assert( pagerUseWal(pPager) );

  53772.   pPg = sqlite3PagerLookup(pPager, iPg);

  53773.   if( pPg ){

  53774.     if( sqlite3PcachePageRefcount(pPg)==1 ){

  53775.       sqlite3PcacheDrop(pPg);

  53776.     }else{

  53777.       rc = readDbPage(pPg);

  53778.       if( rc==SQLITE_OK ){

  53779.         pPager->xReiniter(pPg);

  53780.       }

  53781.       sqlite3PagerUnrefNotNull(pPg);

  53782.     }

  53783.   }

  53784. 

  53785.   /* Normally, if a transaction is rolled back, any backup processes are

  53786.   ** updated as data is copied out of the rollback journal and into the

  53787.   ** database. This is not generally possible with a WAL database, as

  53788.   ** rollback involves simply truncating the log file. Therefore, if one

  53789.   ** or more frames have already been written to the log (and therefore 

  53790.   ** also copied into the backup databases) as part of this transaction,

  53791.   ** the backups must be restarted.

  53792.   */

  53793.   sqlite3BackupRestart(pPager->pBackup);

  53794. 

  53795.   return rc;

  53796. }

  53797. 

  53798. /*

  53799. ** This function is called to rollback a transaction on a WAL database.

  53800. */

  53801. static int pagerRollbackWal(Pager *pPager){

  53802.   int rc;                         /* Return Code */

  53803.   PgHdr *pList;                   /* List of dirty pages to revert */

  53804. 

  53805.   /* For all pages in the cache that are currently dirty or have already

  53806.   ** been written (but not committed) to the log file, do one of the 

  53807.   ** following:

  53808.   **

  53809.   **   + Discard the cached page (if refcount==0), or

  53810.   **   + Reload page content from the database (if refcount>0).

  53811.   */

  53812.   pPager->dbSize = pPager->dbOrigSize;

  53813.   rc = sqlite3WalUndo(pPager->pWal, pagerUndoCallback, (void *)pPager);

  53814.   pList = sqlite3PcacheDirtyList(pPager->pPCache);

  53815.   while( pList && rc==SQLITE_OK ){

  53816.     PgHdr *pNext = pList->pDirty;

  53817.     rc = pagerUndoCallback((void *)pPager, pList->pgno);

  53818.     pList = pNext;

  53819.   }

  53820. 

  53821.   return rc;

  53822. }

  53823. 

  53824. /*

  53825. ** This function is a wrapper around sqlite3WalFrames(). As well as logging

  53826. ** the contents of the list of pages headed by pList (connected by pDirty),

  53827. ** this function notifies any active backup processes that the pages have

  53828. ** changed. 

  53829. **

  53830. ** The list of pages passed into this routine is always sorted by page number.

  53831. ** Hence, if page 1 appears anywhere on the list, it will be the first page.

  53832. */ 

  53833. static int pagerWalFrames(

  53834.   Pager *pPager,                  /* Pager object */

  53835.   PgHdr *pList,                   /* List of frames to log */

  53836.   Pgno nTruncate,                 /* Database size after this commit */

  53837.   int isCommit                    /* True if this is a commit */

  53838. ){

  53839.   int rc;                         /* Return code */

  53840.   int nList;                      /* Number of pages in pList */

  53841.   PgHdr *p;                       /* For looping over pages */

  53842. 

  53843.   assert( pPager->pWal );

  53844.   assert( pList );

  53845. #ifdef SQLITE_DEBUG

  53846.   /* Verify that the page list is in accending order */

  53847.   for(p=pList; p && p->pDirty; p=p->pDirty){

  53848.     assert( p->pgno < p->pDirty->pgno );

  53849.   }

  53850. #endif

  53851. 

  53852.   assert( pList->pDirty==0 || isCommit );

  53853.   if( isCommit ){

  53854.     /* If a WAL transaction is being committed, there is no point in writing

  53855.     ** any pages with page numbers greater than nTruncate into the WAL file.

  53856.     ** They will never be read by any client. So remove them from the pDirty

  53857.     ** list here. */

  53858.     PgHdr **ppNext = &pList;

  53859.     nList = 0;

  53860.     for(p=pList; (*ppNext = p)!=0; p=p->pDirty){

  53861.       if( p->pgno<=nTruncate ){

  53862.         ppNext = &p->pDirty;

  53863.         nList++;

  53864.       }

  53865.     }

  53866.     assert( pList );

  53867.   }else{

  53868.     nList = 1;

  53869.   }

  53870.   pPager->aStat[PAGER_STAT_WRITE] += nList;

  53871. 

  53872.   if( pList->pgno==1 ) pager_write_changecounter(pList);

  53873.   rc = sqlite3WalFrames(pPager->pWal, 

  53874.       pPager->pageSize, pList, nTruncate, isCommit, pPager->walSyncFlags

  53875.   );

  53876.   if( rc==SQLITE_OK && pPager->pBackup ){

  53877.     for(p=pList; p; p=p->pDirty){

  53878.       sqlite3BackupUpdate(pPager->pBackup, p->pgno, (u8 *)p->pData);

  53879.     }

  53880.   }

  53881. 

  53882. #ifdef SQLITE_CHECK_PAGES

  53883.   pList = sqlite3PcacheDirtyList(pPager->pPCache);

  53884.   for(p=pList; p; p=p->pDirty){

  53885.     pager_set_pagehash(p);

  53886.   }

  53887. #endif

  53888. 

  53889.   return rc;

  53890. }

  53891. 

  53892. /*

  53893. ** Begin a read transaction on the WAL.

  53894. **

  53895. ** This routine used to be called "pagerOpenSnapshot()" because it essentially

  53896. ** makes a snapshot of the database at the current point in time and preserves

  53897. ** that snapshot for use by the reader in spite of concurrently changes by

  53898. ** other writers or checkpointers.

  53899. */

  53900. static int pagerBeginReadTransaction(Pager *pPager){

  53901.   int rc;                         /* Return code */

  53902.   int changed = 0;                /* True if cache must be reset */

  53903. 

  53904.   assert( pagerUseWal(pPager) );

  53905.   assert( pPager->eState==PAGER_OPEN || pPager->eState==PAGER_READER );

  53906. 

  53907.   /* sqlite3WalEndReadTransaction() was not called for the previous

  53908.   ** transaction in locking_mode=EXCLUSIVE.  So call it now.  If we

  53909.   ** are in locking_mode=NORMAL and EndRead() was previously called,

  53910.   ** the duplicate call is harmless.

  53911.   */

  53912.   sqlite3WalEndReadTransaction(pPager->pWal);

  53913. 

  53914.   rc = sqlite3WalBeginReadTransaction(pPager->pWal, &changed);

  53915.   if( rc!=SQLITE_OK || changed ){

  53916.     pager_reset(pPager);

  53917.     if( USEFETCH(pPager) ) sqlite3OsUnfetch(pPager->fd, 0, 0);

  53918.   }

  53919. 

  53920.   return rc;

  53921. }

  53922. #endif

  53923. 

  53924. /*

  53925. ** This function is called as part of the transition from PAGER_OPEN

  53926. ** to PAGER_READER state to determine the size of the database file

  53927. ** in pages (assuming the page size currently stored in Pager.pageSize).

  53928. **

  53929. ** If no error occurs, SQLITE_OK is returned and the size of the database

  53930. ** in pages is stored in *pnPage. Otherwise, an error code (perhaps

  53931. ** SQLITE_IOERR_FSTAT) is returned and *pnPage is left unmodified.

  53932. */

  53933. static int pagerPagecount(Pager *pPager, Pgno *pnPage){

  53934.   Pgno nPage;                     /* Value to return via *pnPage */

  53935. 

  53936.   /* Query the WAL sub-system for the database size. The WalDbsize()

  53937.   ** function returns zero if the WAL is not open (i.e. Pager.pWal==0), or

  53938.   ** if the database size is not available. The database size is not

  53939.   ** available from the WAL sub-system if the log file is empty or

  53940.   ** contains no valid committed transactions.

  53941.   */

  53942.   assert( pPager->eState==PAGER_OPEN );

  53943.   assert( pPager->eLock>=SHARED_LOCK );

  53944.   assert( isOpen(pPager->fd) );

  53945.   assert( pPager->tempFile==0 );

  53946.   nPage = sqlite3WalDbsize(pPager->pWal);

  53947. 

  53948.   /* If the number of pages in the database is not available from the

  53949.   ** WAL sub-system, determine the page count based on the size of

  53950.   ** the database file.  If the size of the database file is not an

  53951.   ** integer multiple of the page-size, round up the result.

  53952.   */

  53953.   if( nPage==0 && ALWAYS(isOpen(pPager->fd)) ){

  53954.     i64 n = 0;                    /* Size of db file in bytes */

  53955.     int rc = sqlite3OsFileSize(pPager->fd, &n);

  53956.     if( rc!=SQLITE_OK ){

  53957.       return rc;

  53958.     }

  53959.     nPage = (Pgno)((n+pPager->pageSize-1) / pPager->pageSize);

  53960.   }

  53961. 

  53962.   /* If the current number of pages in the file is greater than the

  53963.   ** configured maximum pager number, increase the allowed limit so

  53964.   ** that the file can be read.

  53965.   */

  53966.   if( nPage>pPager->mxPgno ){

  53967.     pPager->mxPgno = (Pgno)nPage;

  53968.   }

  53969. 

  53970.   *pnPage = nPage;

  53971.   return SQLITE_OK;

  53972. }

  53973. 

  53974. #ifndef SQLITE_OMIT_WAL

  53975. /*

  53976. ** Check if the *-wal file that corresponds to the database opened by pPager

  53977. ** exists if the database is not empy, or verify that the *-wal file does

  53978. ** not exist (by deleting it) if the database file is empty.

  53979. **

  53980. ** If the database is not empty and the *-wal file exists, open the pager

  53981. ** in WAL mode.  If the database is empty or if no *-wal file exists and

  53982. ** if no error occurs, make sure Pager.journalMode is not set to

  53983. ** PAGER_JOURNALMODE_WAL.

  53984. **

  53985. ** Return SQLITE_OK or an error code.

  53986. **

  53987. ** The caller must hold a SHARED lock on the database file to call this

  53988. ** function. Because an EXCLUSIVE lock on the db file is required to delete 

  53989. ** a WAL on a none-empty database, this ensures there is no race condition 

  53990. ** between the xAccess() below and an xDelete() being executed by some 

  53991. ** other connection.

  53992. */

  53993. static int pagerOpenWalIfPresent(Pager *pPager){

  53994.   int rc = SQLITE_OK;

  53995.   assert( pPager->eState==PAGER_OPEN );

  53996.   assert( pPager->eLock>=SHARED_LOCK );

  53997. 

  53998.   if( !pPager->tempFile ){

  53999.     int isWal;                    /* True if WAL file exists */

  54000.     rc = sqlite3OsAccess(

  54001.         pPager->pVfs, pPager->zWal, SQLITE_ACCESS_EXISTS, &isWal

  54002.     );

  54003.     if( rc==SQLITE_OK ){

  54004.       if( isWal ){

  54005.         Pgno nPage;                   /* Size of the database file */

  54006. 

  54007.         rc = pagerPagecount(pPager, &nPage);

  54008.         if( rc ) return rc;

  54009.         if( nPage==0 ){

  54010.           rc = sqlite3OsDelete(pPager->pVfs, pPager->zWal, 0);

  54011.         }else{

  54012.           testcase( sqlite3PcachePagecount(pPager->pPCache)==0 );

  54013.           rc = sqlite3PagerOpenWal(pPager, 0);

  54014.         }

  54015.       }else if( pPager->journalMode==PAGER_JOURNALMODE_WAL ){

  54016.         pPager->journalMode = PAGER_JOURNALMODE_DELETE;

  54017.       }

  54018.     }

  54019.   }

  54020.   return rc;

  54021. }

  54022. #endif

  54023. 

  54024. /*

  54025. ** Playback savepoint pSavepoint. Or, if pSavepoint==NULL, then playback

  54026. ** the entire master journal file. The case pSavepoint==NULL occurs when 

  54027. ** a ROLLBACK TO command is invoked on a SAVEPOINT that is a transaction 

  54028. ** savepoint.

  54029. **

  54030. ** When pSavepoint is not NULL (meaning a non-transaction savepoint is 

  54031. ** being rolled back), then the rollback consists of up to three stages,

  54032. ** performed in the order specified:

  54033. **

  54034. **   * Pages are played back from the main journal starting at byte

  54035. **     offset PagerSavepoint.iOffset and continuing to 

  54036. **     PagerSavepoint.iHdrOffset, or to the end of the main journal

  54037. **     file if PagerSavepoint.iHdrOffset is zero.

  54038. **

  54039. **   * If PagerSavepoint.iHdrOffset is not zero, then pages are played

  54040. **     back starting from the journal header immediately following 

  54041. **     PagerSavepoint.iHdrOffset to the end of the main journal file.

  54042. **

  54043. **   * Pages are then played back from the sub-journal file, starting

  54044. **     with the PagerSavepoint.iSubRec and continuing to the end of

  54045. **     the journal file.

  54046. **

  54047. ** Throughout the rollback process, each time a page is rolled back, the

  54048. ** corresponding bit is set in a bitvec structure (variable pDone in the

  54049. ** implementation below). This is used to ensure that a page is only

  54050. ** rolled back the first time it is encountered in either journal.

  54051. **

  54052. ** If pSavepoint is NULL, then pages are only played back from the main

  54053. ** journal file. There is no need for a bitvec in this case.

  54054. **

  54055. ** In either case, before playback commences the Pager.dbSize variable

  54056. ** is reset to the value that it held at the start of the savepoint 

  54057. ** (or transaction). No page with a page-number greater than this value

  54058. ** is played back. If one is encountered it is simply skipped.

  54059. */

  54060. static int pagerPlaybackSavepoint(Pager *pPager, PagerSavepoint *pSavepoint){

  54061.   i64 szJ;                 /* Effective size of the main journal */

  54062.   i64 iHdrOff;             /* End of first segment of main-journal records */

  54063.   int rc = SQLITE_OK;      /* Return code */

  54064.   Bitvec *pDone = 0;       /* Bitvec to ensure pages played back only once */

  54065. 

  54066.   assert( pPager->eState!=PAGER_ERROR );

  54067.   assert( pPager->eState>=PAGER_WRITER_LOCKED );

  54068. 

  54069.   /* Allocate a bitvec to use to store the set of pages rolled back */

  54070.   if( pSavepoint ){

  54071.     pDone = sqlite3BitvecCreate(pSavepoint->nOrig);

  54072.     if( !pDone ){

  54073.       return SQLITE_NOMEM_BKPT;

  54074.     }

  54075.   }

  54076. 

  54077.   /* Set the database size back to the value it was before the savepoint 

  54078.   ** being reverted was opened.

  54079.   */

  54080.   pPager->dbSize = pSavepoint ? pSavepoint->nOrig : pPager->dbOrigSize;

  54081.   pPager->changeCountDone = pPager->tempFile;

  54082. 

  54083.   if( !pSavepoint && pagerUseWal(pPager) ){

  54084.     return pagerRollbackWal(pPager);

  54085.   }

  54086. 

  54087.   /* Use pPager->journalOff as the effective size of the main rollback

  54088.   ** journal.  The actual file might be larger than this in

  54089.   ** PAGER_JOURNALMODE_TRUNCATE or PAGER_JOURNALMODE_PERSIST.  But anything

  54090.   ** past pPager->journalOff is off-limits to us.

  54091.   */

  54092.   szJ = pPager->journalOff;

  54093.   assert( pagerUseWal(pPager)==0 || szJ==0 );

  54094. 

  54095.   /* Begin by rolling back records from the main journal starting at

  54096.   ** PagerSavepoint.iOffset and continuing to the next journal header.

  54097.   ** There might be records in the main journal that have a page number

  54098.   ** greater than the current database size (pPager->dbSize) but those

  54099.   ** will be skipped automatically.  Pages are added to pDone as they

  54100.   ** are played back.

  54101.   */

  54102.   if( pSavepoint && !pagerUseWal(pPager) ){

  54103.     iHdrOff = pSavepoint->iHdrOffset ? pSavepoint->iHdrOffset : szJ;

  54104.     pPager->journalOff = pSavepoint->iOffset;

  54105.     while( rc==SQLITE_OK && pPager->journalOff<iHdrOff ){

  54106.       rc = pager_playback_one_page(pPager, &pPager->journalOff, pDone, 1, 1);

  54107.     }

  54108.     assert( rc!=SQLITE_DONE );

  54109.   }else{

  54110.     pPager->journalOff = 0;

  54111.   }

  54112. 

  54113.   /* Continue rolling back records out of the main journal starting at

  54114.   ** the first journal header seen and continuing until the effective end

  54115.   ** of the main journal file.  Continue to skip out-of-range pages and

  54116.   ** continue adding pages rolled back to pDone.

  54117.   */

  54118.   while( rc==SQLITE_OK && pPager->journalOff<szJ ){

  54119.     u32 ii;            /* Loop counter */

  54120.     u32 nJRec = 0;     /* Number of Journal Records */

  54121.     u32 dummy;

  54122.     rc = readJournalHdr(pPager, 0, szJ, &nJRec, &dummy);

  54123.     assert( rc!=SQLITE_DONE );

  54124. 

  54125.     /*

  54126.     ** The "pPager->journalHdr+JOURNAL_HDR_SZ(pPager)==pPager->journalOff"

  54127.     ** test is related to ticket #2565.  See the discussion in the

  54128.     ** pager_playback() function for additional information.

  54129.     */

  54130.     if( nJRec==0 

  54131.      && pPager->journalHdr+JOURNAL_HDR_SZ(pPager)==pPager->journalOff

  54132.     ){

  54133.       nJRec = (u32)((szJ - pPager->journalOff)/JOURNAL_PG_SZ(pPager));

  54134.     }

  54135.     for(ii=0; rc==SQLITE_OK && ii<nJRec && pPager->journalOff<szJ; ii++){

  54136.       rc = pager_playback_one_page(pPager, &pPager->journalOff, pDone, 1, 1);

  54137.     }

  54138.     assert( rc!=SQLITE_DONE );

  54139.   }

  54140.   assert( rc!=SQLITE_OK || pPager->journalOff>=szJ );

  54141. 

  54142.   /* Finally,  rollback pages from the sub-journal.  Page that were

  54143.   ** previously rolled back out of the main journal (and are hence in pDone)

  54144.   ** will be skipped.  Out-of-range pages are also skipped.

  54145.   */

  54146.   if( pSavepoint ){

  54147.     u32 ii;            /* Loop counter */

  54148.     i64 offset = (i64)pSavepoint->iSubRec*(4+pPager->pageSize);

  54149. 

  54150.     if( pagerUseWal(pPager) ){

  54151.       rc = sqlite3WalSavepointUndo(pPager->pWal, pSavepoint->aWalData);

  54152.     }

  54153.     for(ii=pSavepoint->iSubRec; rc==SQLITE_OK && ii<pPager->nSubRec; ii++){

  54154.       assert( offset==(i64)ii*(4+pPager->pageSize) );

  54155.       rc = pager_playback_one_page(pPager, &offset, pDone, 0, 1);

  54156.     }

  54157.     assert( rc!=SQLITE_DONE );

  54158.   }

  54159. 

  54160.   sqlite3BitvecDestroy(pDone);

  54161.   if( rc==SQLITE_OK ){

  54162.     pPager->journalOff = szJ;

  54163.   }

  54164. 

  54165.   return rc;

  54166. }

  54167. 

  54168. /*

  54169. ** Change the maximum number of in-memory pages that are allowed

  54170. ** before attempting to recycle clean and unused pages.

  54171. */

  54172. SQLITE_PRIVATE void sqlite3PagerSetCachesize(Pager *pPager, int mxPage){

  54173.   sqlite3PcacheSetCachesize(pPager->pPCache, mxPage);

  54174. }

  54175. 

  54176. /*

  54177. ** Change the maximum number of in-memory pages that are allowed

  54178. ** before attempting to spill pages to journal.

  54179. */

  54180. SQLITE_PRIVATE int sqlite3PagerSetSpillsize(Pager *pPager, int mxPage){

  54181.   return sqlite3PcacheSetSpillsize(pPager->pPCache, mxPage);

  54182. }

  54183. 

  54184. /*

  54185. ** Invoke SQLITE_FCNTL_MMAP_SIZE based on the current value of szMmap.

  54186. */

  54187. static void pagerFixMaplimit(Pager *pPager){

  54188. #if SQLITE_MAX_MMAP_SIZE>0

  54189.   sqlite3_file *fd = pPager->fd;

  54190.   if( isOpen(fd) && fd->pMethods->iVersion>=3 ){

  54191.     sqlite3_int64 sz;

  54192.     sz = pPager->szMmap;

  54193.     pPager->bUseFetch = (sz>0);

  54194.     setGetterMethod(pPager);

  54195.     sqlite3OsFileControlHint(pPager->fd, SQLITE_FCNTL_MMAP_SIZE, &sz);

  54196.   }

  54197. #endif

  54198. }

  54199. 

  54200. /*

  54201. ** Change the maximum size of any memory mapping made of the database file.

  54202. */

  54203. SQLITE_PRIVATE void sqlite3PagerSetMmapLimit(Pager *pPager, sqlite3_int64 szMmap){

  54204.   pPager->szMmap = szMmap;

  54205.   pagerFixMaplimit(pPager);

  54206. }

  54207. 

  54208. /*

  54209. ** Free as much memory as possible from the pager.

  54210. */

  54211. SQLITE_PRIVATE void sqlite3PagerShrink(Pager *pPager){

  54212.   sqlite3PcacheShrink(pPager->pPCache);

  54213. }

  54214. 

  54215. /*

  54216. ** Adjust settings of the pager to those specified in the pgFlags parameter.

  54217. **

  54218. ** The "level" in pgFlags & PAGER_SYNCHRONOUS_MASK sets the robustness

  54219. ** of the database to damage due to OS crashes or power failures by

  54220. ** changing the number of syncs()s when writing the journals.

  54221. ** There are four levels:

  54222. **

  54223. **    OFF       sqlite3OsSync() is never called.  This is the default

  54224. **              for temporary and transient files.

  54225. **

  54226. **    NORMAL    The journal is synced once before writes begin on the

  54227. **              database.  This is normally adequate protection, but

  54228. **              it is theoretically possible, though very unlikely,

  54229. **              that an inopertune power failure could leave the journal

  54230. **              in a state which would cause damage to the database

  54231. **              when it is rolled back.

  54232. **

  54233. **    FULL      The journal is synced twice before writes begin on the

  54234. **              database (with some additional information - the nRec field

  54235. **              of the journal header - being written in between the two

  54236. **              syncs).  If we assume that writing a

  54237. **              single disk sector is atomic, then this mode provides

  54238. **              assurance that the journal will not be corrupted to the

  54239. **              point of causing damage to the database during rollback.

  54240. **

  54241. **    EXTRA     This is like FULL except that is also syncs the directory

  54242. **              that contains the rollback journal after the rollback

  54243. **              journal is unlinked.

  54244. **

  54245. ** The above is for a rollback-journal mode.  For WAL mode, OFF continues

  54246. ** to mean that no syncs ever occur.  NORMAL means that the WAL is synced

  54247. ** prior to the start of checkpoint and that the database file is synced

  54248. ** at the conclusion of the checkpoint if the entire content of the WAL

  54249. ** was written back into the database.  But no sync operations occur for

  54250. ** an ordinary commit in NORMAL mode with WAL.  FULL means that the WAL

  54251. ** file is synced following each commit operation, in addition to the

  54252. ** syncs associated with NORMAL.  There is no difference between FULL

  54253. ** and EXTRA for WAL mode.

  54254. **

  54255. ** Do not confuse synchronous=FULL with SQLITE_SYNC_FULL.  The

  54256. ** SQLITE_SYNC_FULL macro means to use the MacOSX-style full-fsync

  54257. ** using fcntl(F_FULLFSYNC).  SQLITE_SYNC_NORMAL means to do an

  54258. ** ordinary fsync() call.  There is no difference between SQLITE_SYNC_FULL

  54259. ** and SQLITE_SYNC_NORMAL on platforms other than MacOSX.  But the

  54260. ** synchronous=FULL versus synchronous=NORMAL setting determines when

  54261. ** the xSync primitive is called and is relevant to all platforms.

  54262. **

  54263. ** Numeric values associated with these states are OFF==1, NORMAL=2,

  54264. ** and FULL=3.

  54265. */

  54266. #ifndef SQLITE_OMIT_PAGER_PRAGMAS

  54267. SQLITE_PRIVATE void sqlite3PagerSetFlags(

  54268.   Pager *pPager,        /* The pager to set safety level for */

  54269.   unsigned pgFlags      /* Various flags */

  54270. ){

  54271.   unsigned level = pgFlags & PAGER_SYNCHRONOUS_MASK;

  54272.   if( pPager->tempFile ){

  54273.     pPager->noSync = 1;

  54274.     pPager->fullSync = 0;

  54275.     pPager->extraSync = 0;

  54276.   }else{

  54277.     pPager->noSync =  level==PAGER_SYNCHRONOUS_OFF ?1:0;

  54278.     pPager->fullSync = level>=PAGER_SYNCHRONOUS_FULL ?1:0;

  54279.     pPager->extraSync = level==PAGER_SYNCHRONOUS_EXTRA ?1:0;

  54280.   }

  54281.   if( pPager->noSync ){

  54282.     pPager->syncFlags = 0;

  54283.   }else if( pgFlags & PAGER_FULLFSYNC ){

  54284.     pPager->syncFlags = SQLITE_SYNC_FULL;

  54285.   }else{

  54286.     pPager->syncFlags = SQLITE_SYNC_NORMAL;

  54287.   }

  54288.   pPager->walSyncFlags = (pPager->syncFlags<<2);

  54289.   if( pPager->fullSync ){

  54290.     pPager->walSyncFlags |= pPager->syncFlags;

  54291.   }

  54292.   if( (pgFlags & PAGER_CKPT_FULLFSYNC) && !pPager->noSync ){

  54293.     pPager->walSyncFlags |= (SQLITE_SYNC_FULL<<2);

  54294.   }

  54295.   if( pgFlags & PAGER_CACHESPILL ){

  54296.     pPager->doNotSpill &= ~SPILLFLAG_OFF;

  54297.   }else{

  54298.     pPager->doNotSpill |= SPILLFLAG_OFF;

  54299.   }

  54300. }

  54301. #endif

  54302. 

  54303. /*

  54304. ** The following global variable is incremented whenever the library

  54305. ** attempts to open a temporary file.  This information is used for

  54306. ** testing and analysis only.  

  54307. */

  54308. #ifdef SQLITE_TEST

  54309. SQLITE_API int sqlite3_opentemp_count = 0;

  54310. #endif

  54311. 

  54312. /*

  54313. ** Open a temporary file.

  54314. **

  54315. ** Write the file descriptor into *pFile. Return SQLITE_OK on success 

  54316. ** or some other error code if we fail. The OS will automatically 

  54317. ** delete the temporary file when it is closed.

  54318. **

  54319. ** The flags passed to the VFS layer xOpen() call are those specified

  54320. ** by parameter vfsFlags ORed with the following:

  54321. **

  54322. **     SQLITE_OPEN_READWRITE

  54323. **     SQLITE_OPEN_CREATE

  54324. **     SQLITE_OPEN_EXCLUSIVE

  54325. **     SQLITE_OPEN_DELETEONCLOSE

  54326. */

  54327. static int pagerOpentemp(

  54328.   Pager *pPager,        /* The pager object */

  54329.   sqlite3_file *pFile,  /* Write the file descriptor here */

  54330.   int vfsFlags          /* Flags passed through to the VFS */

  54331. ){

  54332.   int rc;               /* Return code */

  54333. 

  54334. #ifdef SQLITE_TEST

  54335.   sqlite3_opentemp_count++;  /* Used for testing and analysis only */

  54336. #endif

  54337. 

  54338.   vfsFlags |=  SQLITE_OPEN_READWRITE | SQLITE_OPEN_CREATE |

  54339.             SQLITE_OPEN_EXCLUSIVE | SQLITE_OPEN_DELETEONCLOSE;

  54340.   rc = sqlite3OsOpen(pPager->pVfs, 0, pFile, vfsFlags, 0);

  54341.   assert( rc!=SQLITE_OK || isOpen(pFile) );

  54342.   return rc;

  54343. }

  54344. 

  54345. /*

  54346. ** Set the busy handler function.

  54347. **

  54348. ** The pager invokes the busy-handler if sqlite3OsLock() returns 

  54349. ** SQLITE_BUSY when trying to upgrade from no-lock to a SHARED lock,

  54350. ** or when trying to upgrade from a RESERVED lock to an EXCLUSIVE 

  54351. ** lock. It does *not* invoke the busy handler when upgrading from

  54352. ** SHARED to RESERVED, or when upgrading from SHARED to EXCLUSIVE

  54353. ** (which occurs during hot-journal rollback). Summary:

  54354. **

  54355. **   Transition                        | Invokes xBusyHandler

  54356. **   --------------------------------------------------------

  54357. **   NO_LOCK       -> SHARED_LOCK      | Yes

  54358. **   SHARED_LOCK   -> RESERVED_LOCK    | No

  54359. **   SHARED_LOCK   -> EXCLUSIVE_LOCK   | No

  54360. **   RESERVED_LOCK -> EXCLUSIVE_LOCK   | Yes

  54361. **

  54362. ** If the busy-handler callback returns non-zero, the lock is 

  54363. ** retried. If it returns zero, then the SQLITE_BUSY error is

  54364. ** returned to the caller of the pager API function.

  54365. */

  54366. SQLITE_PRIVATE void sqlite3PagerSetBusyHandler(

  54367.   Pager *pPager,                       /* Pager object */

  54368.   int (*xBusyHandler)(void *),         /* Pointer to busy-handler function */

  54369.   void *pBusyHandlerArg                /* Argument to pass to xBusyHandler */

  54370. ){

  54371.   void **ap;

  54372.   pPager->xBusyHandler = xBusyHandler;

  54373.   pPager->pBusyHandlerArg = pBusyHandlerArg;

  54374.   ap = (void **)&pPager->xBusyHandler;

  54375.   assert( ((int(*)(void *))(ap[0]))==xBusyHandler );

  54376.   assert( ap[1]==pBusyHandlerArg );

  54377.   sqlite3OsFileControlHint(pPager->fd, SQLITE_FCNTL_BUSYHANDLER, (void *)ap);

  54378. }

  54379. 

  54380. /*

  54381. ** Change the page size used by the Pager object. The new page size 

  54382. ** is passed in *pPageSize.

  54383. **

  54384. ** If the pager is in the error state when this function is called, it

  54385. ** is a no-op. The value returned is the error state error code (i.e. 

  54386. ** one of SQLITE_IOERR, an SQLITE_IOERR_xxx sub-code or SQLITE_FULL).

  54387. **

  54388. ** Otherwise, if all of the following are true:

  54389. **

  54390. **   * the new page size (value of *pPageSize) is valid (a power 

  54391. **     of two between 512 and SQLITE_MAX_PAGE_SIZE, inclusive), and

  54392. **

  54393. **   * there are no outstanding page references, and

  54394. **

  54395. **   * the database is either not an in-memory database or it is

  54396. **     an in-memory database that currently consists of zero pages.

  54397. **

  54398. ** then the pager object page size is set to *pPageSize.

  54399. **

  54400. ** If the page size is changed, then this function uses sqlite3PagerMalloc() 

  54401. ** to obtain a new Pager.pTmpSpace buffer. If this allocation attempt 

  54402. ** fails, SQLITE_NOMEM is returned and the page size remains unchanged. 

  54403. ** In all other cases, SQLITE_OK is returned.

  54404. **

  54405. ** If the page size is not changed, either because one of the enumerated

  54406. ** conditions above is not true, the pager was in error state when this

  54407. ** function was called, or because the memory allocation attempt failed, 

  54408. ** then *pPageSize is set to the old, retained page size before returning.

  54409. */

  54410. SQLITE_PRIVATE int sqlite3PagerSetPagesize(Pager *pPager, u32 *pPageSize, int nReserve){

  54411.   int rc = SQLITE_OK;

  54412. 

  54413.   /* It is not possible to do a full assert_pager_state() here, as this

  54414.   ** function may be called from within PagerOpen(), before the state

  54415.   ** of the Pager object is internally consistent.

  54416.   **

  54417.   ** At one point this function returned an error if the pager was in 

  54418.   ** PAGER_ERROR state. But since PAGER_ERROR state guarantees that

  54419.   ** there is at least one outstanding page reference, this function

  54420.   ** is a no-op for that case anyhow.

  54421.   */

  54422. 

  54423.   u32 pageSize = *pPageSize;

  54424.   assert( pageSize==0 || (pageSize>=512 && pageSize<=SQLITE_MAX_PAGE_SIZE) );

  54425.   if( (pPager->memDb==0 || pPager->dbSize==0)

  54426.    && sqlite3PcacheRefCount(pPager->pPCache)==0 

  54427.    && pageSize && pageSize!=(u32)pPager->pageSize 

  54428.   ){

  54429.     char *pNew = NULL;             /* New temp space */

  54430.     i64 nByte = 0;

  54431. 

  54432.     if( pPager->eState>PAGER_OPEN && isOpen(pPager->fd) ){

  54433.       rc = sqlite3OsFileSize(pPager->fd, &nByte);

  54434.     }

  54435.     if( rc==SQLITE_OK ){

  54436.       /* 8 bytes of zeroed overrun space is sufficient so that the b-tree

  54437.       * cell header parser will never run off the end of the allocation */

  54438.       pNew = (char *)sqlite3PageMalloc(pageSize+8);

  54439.       if( !pNew ){

  54440.         rc = SQLITE_NOMEM_BKPT;

  54441.       }else{

  54442.         memset(pNew+pageSize, 0, 8);

  54443.       }

  54444.     }

  54445. 

  54446.     if( rc==SQLITE_OK ){

  54447.       pager_reset(pPager);

  54448.       rc = sqlite3PcacheSetPageSize(pPager->pPCache, pageSize);

  54449.     }

  54450.     if( rc==SQLITE_OK ){

  54451.       sqlite3PageFree(pPager->pTmpSpace);

  54452.       pPager->pTmpSpace = pNew;

  54453.       pPager->dbSize = (Pgno)((nByte+pageSize-1)/pageSize);

  54454.       pPager->pageSize = pageSize;

  54455.     }else{

  54456.       sqlite3PageFree(pNew);

  54457.     }

  54458.   }

  54459. 

  54460.   *pPageSize = pPager->pageSize;

  54461.   if( rc==SQLITE_OK ){

  54462.     if( nReserve<0 ) nReserve = pPager->nReserve;

  54463.     assert( nReserve>=0 && nReserve<1000 );

  54464.     pPager->nReserve = (i16)nReserve;

  54465.     pagerReportSize(pPager);

  54466.     pagerFixMaplimit(pPager);

  54467.   }

  54468.   return rc;

  54469. }

  54470. 

  54471. /*

  54472. ** Return a pointer to the "temporary page" buffer held internally

  54473. ** by the pager.  This is a buffer that is big enough to hold the

  54474. ** entire content of a database page.  This buffer is used internally

  54475. ** during rollback and will be overwritten whenever a rollback

  54476. ** occurs.  But other modules are free to use it too, as long as

  54477. ** no rollbacks are happening.

  54478. */

  54479. SQLITE_PRIVATE void *sqlite3PagerTempSpace(Pager *pPager){

  54480.   return pPager->pTmpSpace;

  54481. }

  54482. 

  54483. /*

  54484. ** Attempt to set the maximum database page count if mxPage is positive. 

  54485. ** Make no changes if mxPage is zero or negative.  And never reduce the

  54486. ** maximum page count below the current size of the database.

  54487. **

  54488. ** Regardless of mxPage, return the current maximum page count.

  54489. */

  54490. SQLITE_PRIVATE int sqlite3PagerMaxPageCount(Pager *pPager, int mxPage){

  54491.   if( mxPage>0 ){

  54492.     pPager->mxPgno = mxPage;

  54493.   }

  54494.   assert( pPager->eState!=PAGER_OPEN );      /* Called only by OP_MaxPgcnt */

  54495.   /* assert( pPager->mxPgno>=pPager->dbSize ); */

  54496.   /* OP_MaxPgcnt ensures that the parameter passed to this function is not

  54497.   ** less than the total number of valid pages in the database. But this

  54498.   ** may be less than Pager.dbSize, and so the assert() above is not valid */

  54499.   return pPager->mxPgno;

  54500. }

  54501. 

  54502. /*

  54503. ** The following set of routines are used to disable the simulated

  54504. ** I/O error mechanism.  These routines are used to avoid simulated

  54505. ** errors in places where we do not care about errors.

  54506. **

  54507. ** Unless -DSQLITE_TEST=1 is used, these routines are all no-ops

  54508. ** and generate no code.

  54509. */

  54510. #ifdef SQLITE_TEST

  54511. SQLITE_API extern int sqlite3_io_error_pending;

  54512. SQLITE_API extern int sqlite3_io_error_hit;

  54513. static int saved_cnt;

  54514. void disable_simulated_io_errors(void){

  54515.   saved_cnt = sqlite3_io_error_pending;

  54516.   sqlite3_io_error_pending = -1;

  54517. }

  54518. void enable_simulated_io_errors(void){

  54519.   sqlite3_io_error_pending = saved_cnt;

  54520. }

  54521. #else

  54522. # define disable_simulated_io_errors()

  54523. # define enable_simulated_io_errors()

  54524. #endif

  54525. 

  54526. /*

  54527. ** Read the first N bytes from the beginning of the file into memory

  54528. ** that pDest points to. 

  54529. **

  54530. ** If the pager was opened on a transient file (zFilename==""), or

  54531. ** opened on a file less than N bytes in size, the output buffer is

  54532. ** zeroed and SQLITE_OK returned. The rationale for this is that this 

  54533. ** function is used to read database headers, and a new transient or

  54534. ** zero sized database has a header than consists entirely of zeroes.

  54535. **

  54536. ** If any IO error apart from SQLITE_IOERR_SHORT_READ is encountered,

  54537. ** the error code is returned to the caller and the contents of the

  54538. ** output buffer undefined.

  54539. */

  54540. SQLITE_PRIVATE int sqlite3PagerReadFileheader(Pager *pPager, int N, unsigned char *pDest){

  54541.   int rc = SQLITE_OK;

  54542.   memset(pDest, 0, N);

  54543.   assert( isOpen(pPager->fd) || pPager->tempFile );

  54544. 

  54545.   /* This routine is only called by btree immediately after creating

  54546.   ** the Pager object.  There has not been an opportunity to transition

  54547.   ** to WAL mode yet.

  54548.   */

  54549.   assert( !pagerUseWal(pPager) );

  54550. 

  54551.   if( isOpen(pPager->fd) ){

  54552.     IOTRACE(("DBHDR %p 0 %d\n", pPager, N))

  54553.     rc = sqlite3OsRead(pPager->fd, pDest, N, 0);

  54554.     if( rc==SQLITE_IOERR_SHORT_READ ){

  54555.       rc = SQLITE_OK;

  54556.     }

  54557.   }

  54558.   return rc;

  54559. }

  54560. 

  54561. /*

  54562. ** This function may only be called when a read-transaction is open on

  54563. ** the pager. It returns the total number of pages in the database.

  54564. **

  54565. ** However, if the file is between 1 and <page-size> bytes in size, then 

  54566. ** this is considered a 1 page file.

  54567. */

  54568. SQLITE_PRIVATE void sqlite3PagerPagecount(Pager *pPager, int *pnPage){

  54569.   assert( pPager->eState>=PAGER_READER );

  54570.   assert( pPager->eState!=PAGER_WRITER_FINISHED );

  54571.   *pnPage = (int)pPager->dbSize;

  54572. }

  54573. 

  54574. 

  54575. /*

  54576. ** Try to obtain a lock of type locktype on the database file. If

  54577. ** a similar or greater lock is already held, this function is a no-op

  54578. ** (returning SQLITE_OK immediately).

  54579. **

  54580. ** Otherwise, attempt to obtain the lock using sqlite3OsLock(). Invoke 

  54581. ** the busy callback if the lock is currently not available. Repeat 

  54582. ** until the busy callback returns false or until the attempt to 

  54583. ** obtain the lock succeeds.

  54584. **

  54585. ** Return SQLITE_OK on success and an error code if we cannot obtain

  54586. ** the lock. If the lock is obtained successfully, set the Pager.state 

  54587. ** variable to locktype before returning.

  54588. */

  54589. static int pager_wait_on_lock(Pager *pPager, int locktype){

  54590.   int rc;                              /* Return code */

  54591. 

  54592.   /* Check that this is either a no-op (because the requested lock is 

  54593.   ** already held), or one of the transitions that the busy-handler

  54594.   ** may be invoked during, according to the comment above

  54595.   ** sqlite3PagerSetBusyhandler().

  54596.   */

  54597.   assert( (pPager->eLock>=locktype)

  54598.        || (pPager->eLock==NO_LOCK && locktype==SHARED_LOCK)

  54599.        || (pPager->eLock==RESERVED_LOCK && locktype==EXCLUSIVE_LOCK)

  54600.   );

  54601. 

  54602.   do {

  54603.     rc = pagerLockDb(pPager, locktype);

  54604.   }while( rc==SQLITE_BUSY && pPager->xBusyHandler(pPager->pBusyHandlerArg) );

  54605.   return rc;

  54606. }

  54607. 

  54608. /*

  54609. ** Function assertTruncateConstraint(pPager) checks that one of the 

  54610. ** following is true for all dirty pages currently in the page-cache:

  54611. **

  54612. **   a) The page number is less than or equal to the size of the 

  54613. **      current database image, in pages, OR

  54614. **

  54615. **   b) if the page content were written at this time, it would not

  54616. **      be necessary to write the current content out to the sub-journal

  54617. **      (as determined by function subjRequiresPage()).

  54618. **

  54619. ** If the condition asserted by this function were not true, and the

  54620. ** dirty page were to be discarded from the cache via the pagerStress()

  54621. ** routine, pagerStress() would not write the current page content to

  54622. ** the database file. If a savepoint transaction were rolled back after

  54623. ** this happened, the correct behavior would be to restore the current

  54624. ** content of the page. However, since this content is not present in either

  54625. ** the database file or the portion of the rollback journal and 

  54626. ** sub-journal rolled back the content could not be restored and the

  54627. ** database image would become corrupt. It is therefore fortunate that 

  54628. ** this circumstance cannot arise.

  54629. */

  54630. #if defined(SQLITE_DEBUG)

  54631. static void assertTruncateConstraintCb(PgHdr *pPg){

  54632.   assert( pPg->flags&PGHDR_DIRTY );

  54633.   assert( !subjRequiresPage(pPg) || pPg->pgno<=pPg->pPager->dbSize );

  54634. }

  54635. static void assertTruncateConstraint(Pager *pPager){

  54636.   sqlite3PcacheIterateDirty(pPager->pPCache, assertTruncateConstraintCb);

  54637. }

  54638. #else

  54639. # define assertTruncateConstraint(pPager)

  54640. #endif

  54641. 

  54642. /*

  54643. ** Truncate the in-memory database file image to nPage pages. This 

  54644. ** function does not actually modify the database file on disk. It 

  54645. ** just sets the internal state of the pager object so that the 

  54646. ** truncation will be done when the current transaction is committed.

  54647. **

  54648. ** This function is only called right before committing a transaction.

  54649. ** Once this function has been called, the transaction must either be

  54650. ** rolled back or committed. It is not safe to call this function and

  54651. ** then continue writing to the database.

  54652. */

  54653. SQLITE_PRIVATE void sqlite3PagerTruncateImage(Pager *pPager, Pgno nPage){

  54654.   assert( pPager->dbSize>=nPage );

  54655.   assert( pPager->eState>=PAGER_WRITER_CACHEMOD );

  54656.   pPager->dbSize = nPage;

  54657. 

  54658.   /* At one point the code here called assertTruncateConstraint() to

  54659.   ** ensure that all pages being truncated away by this operation are,

  54660.   ** if one or more savepoints are open, present in the savepoint 

  54661.   ** journal so that they can be restored if the savepoint is rolled

  54662.   ** back. This is no longer necessary as this function is now only

  54663.   ** called right before committing a transaction. So although the 

  54664.   ** Pager object may still have open savepoints (Pager.nSavepoint!=0), 

  54665.   ** they cannot be rolled back. So the assertTruncateConstraint() call

  54666.   ** is no longer correct. */

  54667. }

  54668. 

  54669. 

  54670. /*

  54671. ** This function is called before attempting a hot-journal rollback. It

  54672. ** syncs the journal file to disk, then sets pPager->journalHdr to the

  54673. ** size of the journal file so that the pager_playback() routine knows

  54674. ** that the entire journal file has been synced.

  54675. **

  54676. ** Syncing a hot-journal to disk before attempting to roll it back ensures 

  54677. ** that if a power-failure occurs during the rollback, the process that

  54678. ** attempts rollback following system recovery sees the same journal

  54679. ** content as this process.

  54680. **

  54681. ** If everything goes as planned, SQLITE_OK is returned. Otherwise, 

  54682. ** an SQLite error code.

  54683. */

  54684. static int pagerSyncHotJournal(Pager *pPager){

  54685.   int rc = SQLITE_OK;

  54686.   if( !pPager->noSync ){

  54687.     rc = sqlite3OsSync(pPager->jfd, SQLITE_SYNC_NORMAL);

  54688.   }

  54689.   if( rc==SQLITE_OK ){

  54690.     rc = sqlite3OsFileSize(pPager->jfd, &pPager->journalHdr);

  54691.   }

  54692.   return rc;

  54693. }

  54694. 

  54695. #if SQLITE_MAX_MMAP_SIZE>0

  54696. /*

  54697. ** Obtain a reference to a memory mapped page object for page number pgno. 

  54698. ** The new object will use the pointer pData, obtained from xFetch().

  54699. ** If successful, set *ppPage to point to the new page reference

  54700. ** and return SQLITE_OK. Otherwise, return an SQLite error code and set

  54701. ** *ppPage to zero.

  54702. **

  54703. ** Page references obtained by calling this function should be released

  54704. ** by calling pagerReleaseMapPage().

  54705. */

  54706. static int pagerAcquireMapPage(

  54707.   Pager *pPager,                  /* Pager object */

  54708.   Pgno pgno,                      /* Page number */

  54709.   void *pData,                    /* xFetch()'d data for this page */

  54710.   PgHdr **ppPage                  /* OUT: Acquired page object */

  54711. ){

  54712.   PgHdr *p;                       /* Memory mapped page to return */

  54713.   

  54714.   if( pPager->pMmapFreelist ){

  54715.     *ppPage = p = pPager->pMmapFreelist;

  54716.     pPager->pMmapFreelist = p->pDirty;

  54717.     p->pDirty = 0;

  54718.     assert( pPager->nExtra>=8 );

  54719.     memset(p->pExtra, 0, 8);

  54720.   }else{

  54721.     *ppPage = p = (PgHdr *)sqlite3MallocZero(sizeof(PgHdr) + pPager->nExtra);

  54722.     if( p==0 ){

  54723.       sqlite3OsUnfetch(pPager->fd, (i64)(pgno-1) * pPager->pageSize, pData);

  54724.       return SQLITE_NOMEM_BKPT;

  54725.     }

  54726.     p->pExtra = (void *)&p[1];

  54727.     p->flags = PGHDR_MMAP;

  54728.     p->nRef = 1;

  54729.     p->pPager = pPager;

  54730.   }

  54731. 

  54732.   assert( p->pExtra==(void *)&p[1] );

  54733.   assert( p->pPage==0 );

  54734.   assert( p->flags==PGHDR_MMAP );

  54735.   assert( p->pPager==pPager );

  54736.   assert( p->nRef==1 );

  54737. 

  54738.   p->pgno = pgno;

  54739.   p->pData = pData;

  54740.   pPager->nMmapOut++;

  54741. 

  54742.   return SQLITE_OK;

  54743. }

  54744. #endif

  54745. 

  54746. /*

  54747. ** Release a reference to page pPg. pPg must have been returned by an 

  54748. ** earlier call to pagerAcquireMapPage().

  54749. */

  54750. static void pagerReleaseMapPage(PgHdr *pPg){

  54751.   Pager *pPager = pPg->pPager;

  54752.   pPager->nMmapOut--;

  54753.   pPg->pDirty = pPager->pMmapFreelist;

  54754.   pPager->pMmapFreelist = pPg;

  54755. 

  54756.   assert( pPager->fd->pMethods->iVersion>=3 );

  54757.   sqlite3OsUnfetch(pPager->fd, (i64)(pPg->pgno-1)*pPager->pageSize, pPg->pData);

  54758. }

  54759. 

  54760. /*

  54761. ** Free all PgHdr objects stored in the Pager.pMmapFreelist list.

  54762. */

  54763. static void pagerFreeMapHdrs(Pager *pPager){

  54764.   PgHdr *p;

  54765.   PgHdr *pNext;

  54766.   for(p=pPager->pMmapFreelist; p; p=pNext){

  54767.     pNext = p->pDirty;

  54768.     sqlite3_free(p);

  54769.   }

  54770. }

  54771. 

  54772. /* Verify that the database file has not be deleted or renamed out from

  54773. ** under the pager.  Return SQLITE_OK if the database is still where it ought

  54774. ** to be on disk.  Return non-zero (SQLITE_READONLY_DBMOVED or some other error

  54775. ** code from sqlite3OsAccess()) if the database has gone missing.

  54776. */

  54777. static int databaseIsUnmoved(Pager *pPager){

  54778.   int bHasMoved = 0;

  54779.   int rc;

  54780. 

  54781.   if( pPager->tempFile ) return SQLITE_OK;

  54782.   if( pPager->dbSize==0 ) return SQLITE_OK;

  54783.   assert( pPager->zFilename && pPager->zFilename[0] );

  54784.   rc = sqlite3OsFileControl(pPager->fd, SQLITE_FCNTL_HAS_MOVED, &bHasMoved);

  54785.   if( rc==SQLITE_NOTFOUND ){

  54786.     /* If the HAS_MOVED file-control is unimplemented, assume that the file

  54787.     ** has not been moved.  That is the historical behavior of SQLite: prior to

  54788.     ** version 3.8.3, it never checked */

  54789.     rc = SQLITE_OK;

  54790.   }else if( rc==SQLITE_OK && bHasMoved ){

  54791.     rc = SQLITE_READONLY_DBMOVED;

  54792.   }

  54793.   return rc;

  54794. }

  54795. 

  54796. 

  54797. /*

  54798. ** Shutdown the page cache.  Free all memory and close all files.

  54799. **

  54800. ** If a transaction was in progress when this routine is called, that

  54801. ** transaction is rolled back.  All outstanding pages are invalidated

  54802. ** and their memory is freed.  Any attempt to use a page associated

  54803. ** with this page cache after this function returns will likely

  54804. ** result in a coredump.

  54805. **

  54806. ** This function always succeeds. If a transaction is active an attempt

  54807. ** is made to roll it back. If an error occurs during the rollback 

  54808. ** a hot journal may be left in the filesystem but no error is returned

  54809. ** to the caller.

  54810. */

  54811. SQLITE_PRIVATE int sqlite3PagerClose(Pager *pPager, sqlite3 *db){

  54812.   u8 *pTmp = (u8*)pPager->pTmpSpace;

  54813.   assert( db || pagerUseWal(pPager)==0 );

  54814.   assert( assert_pager_state(pPager) );

  54815.   disable_simulated_io_errors();

  54816.   sqlite3BeginBenignMalloc();

  54817.   pagerFreeMapHdrs(pPager);

  54818.   /* pPager->errCode = 0; */

  54819.   pPager->exclusiveMode = 0;

  54820. #ifndef SQLITE_OMIT_WAL

  54821.   {

  54822.     u8 *a = 0;

  54823.     assert( db || pPager->pWal==0 );

  54824.     if( db && 0==(db->flags & SQLITE_NoCkptOnClose) 

  54825.      && SQLITE_OK==databaseIsUnmoved(pPager)

  54826.     ){

  54827.       a = pTmp;

  54828.     }

  54829.     sqlite3WalClose(pPager->pWal, db, pPager->walSyncFlags, pPager->pageSize,a);

  54830.     pPager->pWal = 0;

  54831.   }

  54832. #endif

  54833.   pager_reset(pPager);

  54834.   if( MEMDB ){

  54835.     pager_unlock(pPager);

  54836.   }else{

  54837.     /* If it is open, sync the journal file before calling UnlockAndRollback.

  54838.     ** If this is not done, then an unsynced portion of the open journal 

  54839.     ** file may be played back into the database. If a power failure occurs 

  54840.     ** while this is happening, the database could become corrupt.

  54841.     **

  54842.     ** If an error occurs while trying to sync the journal, shift the pager

  54843.     ** into the ERROR state. This causes UnlockAndRollback to unlock the

  54844.     ** database and close the journal file without attempting to roll it

  54845.     ** back or finalize it. The next database user will have to do hot-journal

  54846.     ** rollback before accessing the database file.

  54847.     */

  54848.     if( isOpen(pPager->jfd) ){

  54849.       pager_error(pPager, pagerSyncHotJournal(pPager));

  54850.     }

  54851.     pagerUnlockAndRollback(pPager);

  54852.   }

  54853.   sqlite3EndBenignMalloc();

  54854.   enable_simulated_io_errors();

  54855.   PAGERTRACE(("CLOSE %d\n", PAGERID(pPager)));

  54856.   IOTRACE(("CLOSE %p\n", pPager))

  54857.   sqlite3OsClose(pPager->jfd);

  54858.   sqlite3OsClose(pPager->fd);

  54859.   sqlite3PageFree(pTmp);

  54860.   sqlite3PcacheClose(pPager->pPCache);

  54861. 

  54862. #ifdef SQLITE_HAS_CODEC

  54863.   if( pPager->xCodecFree ) pPager->xCodecFree(pPager->pCodec);

  54864. #endif

  54865. 

  54866.   assert( !pPager->aSavepoint && !pPager->pInJournal );

  54867.   assert( !isOpen(pPager->jfd) && !isOpen(pPager->sjfd) );

  54868. 

  54869.   sqlite3_free(pPager);

  54870.   return SQLITE_OK;

  54871. }

  54872. 

  54873. #if !defined(NDEBUG) || defined(SQLITE_TEST)

  54874. /*

  54875. ** Return the page number for page pPg.

  54876. */

  54877. SQLITE_PRIVATE Pgno sqlite3PagerPagenumber(DbPage *pPg){

  54878.   return pPg->pgno;

  54879. }

  54880. #endif

  54881. 

  54882. /*

  54883. ** Increment the reference count for page pPg.

  54884. */

  54885. SQLITE_PRIVATE void sqlite3PagerRef(DbPage *pPg){

  54886.   sqlite3PcacheRef(pPg);

  54887. }

  54888. 

  54889. /*

  54890. ** Sync the journal. In other words, make sure all the pages that have

  54891. ** been written to the journal have actually reached the surface of the

  54892. ** disk and can be restored in the event of a hot-journal rollback.

  54893. **

  54894. ** If the Pager.noSync flag is set, then this function is a no-op.

  54895. ** Otherwise, the actions required depend on the journal-mode and the 

  54896. ** device characteristics of the file-system, as follows:

  54897. **

  54898. **   * If the journal file is an in-memory journal file, no action need

  54899. **     be taken.

  54900. **

  54901. **   * Otherwise, if the device does not support the SAFE_APPEND property,

  54902. **     then the nRec field of the most recently written journal header

  54903. **     is updated to contain the number of journal records that have

  54904. **     been written following it. If the pager is operating in full-sync

  54905. **     mode, then the journal file is synced before this field is updated.

  54906. **

  54907. **   * If the device does not support the SEQUENTIAL property, then 

  54908. **     journal file is synced.

  54909. **

  54910. ** Or, in pseudo-code:

  54911. **

  54912. **   if( NOT <in-memory journal> ){

  54913. **     if( NOT SAFE_APPEND ){

  54914. **       if( <full-sync mode> ) xSync(<journal file>);

  54915. **       <update nRec field>

  54916. **     } 

  54917. **     if( NOT SEQUENTIAL ) xSync(<journal file>);

  54918. **   }

  54919. **

  54920. ** If successful, this routine clears the PGHDR_NEED_SYNC flag of every 

  54921. ** page currently held in memory before returning SQLITE_OK. If an IO

  54922. ** error is encountered, then the IO error code is returned to the caller.

  54923. */

  54924. static int syncJournal(Pager *pPager, int newHdr){

  54925.   int rc;                         /* Return code */

  54926. 

  54927.   assert( pPager->eState==PAGER_WRITER_CACHEMOD

  54928.        || pPager->eState==PAGER_WRITER_DBMOD

  54929.   );

  54930.   assert( assert_pager_state(pPager) );

  54931.   assert( !pagerUseWal(pPager) );

  54932. 

  54933.   rc = sqlite3PagerExclusiveLock(pPager);

  54934.   if( rc!=SQLITE_OK ) return rc;

  54935. 

  54936.   if( !pPager->noSync ){

  54937.     assert( !pPager->tempFile );

  54938.     if( isOpen(pPager->jfd) && pPager->journalMode!=PAGER_JOURNALMODE_MEMORY ){

  54939.       const int iDc = sqlite3OsDeviceCharacteristics(pPager->fd);

  54940.       assert( isOpen(pPager->jfd) );

  54941. 

  54942.       if( 0==(iDc&SQLITE_IOCAP_SAFE_APPEND) ){

  54943.         /* This block deals with an obscure problem. If the last connection

  54944.         ** that wrote to this database was operating in persistent-journal

  54945.         ** mode, then the journal file may at this point actually be larger

  54946.         ** than Pager.journalOff bytes. If the next thing in the journal

  54947.         ** file happens to be a journal-header (written as part of the

  54948.         ** previous connection's transaction), and a crash or power-failure 

  54949.         ** occurs after nRec is updated but before this connection writes 

  54950.         ** anything else to the journal file (or commits/rolls back its 

  54951.         ** transaction), then SQLite may become confused when doing the 

  54952.         ** hot-journal rollback following recovery. It may roll back all

  54953.         ** of this connections data, then proceed to rolling back the old,

  54954.         ** out-of-date data that follows it. Database corruption.

  54955.         **

  54956.         ** To work around this, if the journal file does appear to contain

  54957.         ** a valid header following Pager.journalOff, then write a 0x00

  54958.         ** byte to the start of it to prevent it from being recognized.

  54959.         **

  54960.         ** Variable iNextHdrOffset is set to the offset at which this

  54961.         ** problematic header will occur, if it exists. aMagic is used 

  54962.         ** as a temporary buffer to inspect the first couple of bytes of

  54963.         ** the potential journal header.

  54964.         */

  54965.         i64 iNextHdrOffset;

  54966.         u8 aMagic[8];

  54967.         u8 zHeader[sizeof(aJournalMagic)+4];

  54968. 

  54969.         memcpy(zHeader, aJournalMagic, sizeof(aJournalMagic));

  54970.         put32bits(&zHeader[sizeof(aJournalMagic)], pPager->nRec);

  54971. 

  54972.         iNextHdrOffset = journalHdrOffset(pPager);

  54973.         rc = sqlite3OsRead(pPager->jfd, aMagic, 8, iNextHdrOffset);

  54974.         if( rc==SQLITE_OK && 0==memcmp(aMagic, aJournalMagic, 8) ){

  54975.           static const u8 zerobyte = 0;

  54976.           rc = sqlite3OsWrite(pPager->jfd, &zerobyte, 1, iNextHdrOffset);

  54977.         }

  54978.         if( rc!=SQLITE_OK && rc!=SQLITE_IOERR_SHORT_READ ){

  54979.           return rc;

  54980.         }

  54981. 

  54982.         /* Write the nRec value into the journal file header. If in

  54983.         ** full-synchronous mode, sync the journal first. This ensures that

  54984.         ** all data has really hit the disk before nRec is updated to mark

  54985.         ** it as a candidate for rollback.

  54986.         **

  54987.         ** This is not required if the persistent media supports the

  54988.         ** SAFE_APPEND property. Because in this case it is not possible 

  54989.         ** for garbage data to be appended to the file, the nRec field

  54990.         ** is populated with 0xFFFFFFFF when the journal header is written

  54991.         ** and never needs to be updated.

  54992.         */

  54993.         if( pPager->fullSync && 0==(iDc&SQLITE_IOCAP_SEQUENTIAL) ){

  54994.           PAGERTRACE(("SYNC journal of %d\n", PAGERID(pPager)));

  54995.           IOTRACE(("JSYNC %p\n", pPager))

  54996.           rc = sqlite3OsSync(pPager->jfd, pPager->syncFlags);

  54997.           if( rc!=SQLITE_OK ) return rc;

  54998.         }

  54999.         IOTRACE(("JHDR %p %lld\n", pPager, pPager->journalHdr));

  55000.         rc = sqlite3OsWrite(

  55001.             pPager->jfd, zHeader, sizeof(zHeader), pPager->journalHdr

  55002.         );

  55003.         if( rc!=SQLITE_OK ) return rc;

  55004.       }

  55005.       if( 0==(iDc&SQLITE_IOCAP_SEQUENTIAL) ){

  55006.         PAGERTRACE(("SYNC journal of %d\n", PAGERID(pPager)));

  55007.         IOTRACE(("JSYNC %p\n", pPager))

  55008.         rc = sqlite3OsSync(pPager->jfd, pPager->syncFlags| 

  55009.           (pPager->syncFlags==SQLITE_SYNC_FULL?SQLITE_SYNC_DATAONLY:0)

  55010.         );

  55011.         if( rc!=SQLITE_OK ) return rc;

  55012.       }

  55013. 

  55014.       pPager->journalHdr = pPager->journalOff;

  55015.       if( newHdr && 0==(iDc&SQLITE_IOCAP_SAFE_APPEND) ){

  55016.         pPager->nRec = 0;

  55017.         rc = writeJournalHdr(pPager);

  55018.         if( rc!=SQLITE_OK ) return rc;

  55019.       }

  55020.     }else{

  55021.       pPager->journalHdr = pPager->journalOff;

  55022.     }

  55023.   }

  55024. 

  55025.   /* Unless the pager is in noSync mode, the journal file was just 

  55026.   ** successfully synced. Either way, clear the PGHDR_NEED_SYNC flag on 

  55027.   ** all pages.

  55028.   */

  55029.   sqlite3PcacheClearSyncFlags(pPager->pPCache);

  55030.   pPager->eState = PAGER_WRITER_DBMOD;

  55031.   assert( assert_pager_state(pPager) );

  55032.   return SQLITE_OK;

  55033. }

  55034. 

  55035. /*

  55036. ** The argument is the first in a linked list of dirty pages connected

  55037. ** by the PgHdr.pDirty pointer. This function writes each one of the

  55038. ** in-memory pages in the list to the database file. The argument may

  55039. ** be NULL, representing an empty list. In this case this function is

  55040. ** a no-op.

  55041. **

  55042. ** The pager must hold at least a RESERVED lock when this function

  55043. ** is called. Before writing anything to the database file, this lock

  55044. ** is upgraded to an EXCLUSIVE lock. If the lock cannot be obtained,

  55045. ** SQLITE_BUSY is returned and no data is written to the database file.

  55046. ** 

  55047. ** If the pager is a temp-file pager and the actual file-system file

  55048. ** is not yet open, it is created and opened before any data is 

  55049. ** written out.

  55050. **

  55051. ** Once the lock has been upgraded and, if necessary, the file opened,

  55052. ** the pages are written out to the database file in list order. Writing

  55053. ** a page is skipped if it meets either of the following criteria:

  55054. **

  55055. **   * The page number is greater than Pager.dbSize, or

  55056. **   * The PGHDR_DONT_WRITE flag is set on the page.

  55057. **

  55058. ** If writing out a page causes the database file to grow, Pager.dbFileSize

  55059. ** is updated accordingly. If page 1 is written out, then the value cached

  55060. ** in Pager.dbFileVers[] is updated to match the new value stored in

  55061. ** the database file.

  55062. **

  55063. ** If everything is successful, SQLITE_OK is returned. If an IO error 

  55064. ** occurs, an IO error code is returned. Or, if the EXCLUSIVE lock cannot

  55065. ** be obtained, SQLITE_BUSY is returned.

  55066. */

  55067. static int pager_write_pagelist(Pager *pPager, PgHdr *pList){

  55068.   int rc = SQLITE_OK;                  /* Return code */

  55069. 

  55070.   /* This function is only called for rollback pagers in WRITER_DBMOD state. */

  55071.   assert( !pagerUseWal(pPager) );

  55072.   assert( pPager->tempFile || pPager->eState==PAGER_WRITER_DBMOD );

  55073.   assert( pPager->eLock==EXCLUSIVE_LOCK );

  55074.   assert( isOpen(pPager->fd) || pList->pDirty==0 );

  55075. 

  55076.   /* If the file is a temp-file has not yet been opened, open it now. It

  55077.   ** is not possible for rc to be other than SQLITE_OK if this branch

  55078.   ** is taken, as pager_wait_on_lock() is a no-op for temp-files.

  55079.   */

  55080.   if( !isOpen(pPager->fd) ){

  55081.     assert( pPager->tempFile && rc==SQLITE_OK );

  55082.     rc = pagerOpentemp(pPager, pPager->fd, pPager->vfsFlags);

  55083.   }

  55084. 

  55085.   /* Before the first write, give the VFS a hint of what the final

  55086.   ** file size will be.

  55087.   */

  55088.   assert( rc!=SQLITE_OK || isOpen(pPager->fd) );

  55089.   if( rc==SQLITE_OK 

  55090.    && pPager->dbHintSize<pPager->dbSize

  55091.    && (pList->pDirty || pList->pgno>pPager->dbHintSize)

  55092.   ){

  55093.     sqlite3_int64 szFile = pPager->pageSize * (sqlite3_int64)pPager->dbSize;

  55094.     sqlite3OsFileControlHint(pPager->fd, SQLITE_FCNTL_SIZE_HINT, &szFile);

  55095.     pPager->dbHintSize = pPager->dbSize;

  55096.   }

  55097. 

  55098.   while( rc==SQLITE_OK && pList ){

  55099.     Pgno pgno = pList->pgno;

  55100. 

  55101.     /* If there are dirty pages in the page cache with page numbers greater

  55102.     ** than Pager.dbSize, this means sqlite3PagerTruncateImage() was called to

  55103.     ** make the file smaller (presumably by auto-vacuum code). Do not write

  55104.     ** any such pages to the file.

  55105.     **

  55106.     ** Also, do not write out any page that has the PGHDR_DONT_WRITE flag

  55107.     ** set (set by sqlite3PagerDontWrite()).

  55108.     */

  55109.     if( pgno<=pPager->dbSize && 0==(pList->flags&PGHDR_DONT_WRITE) ){

  55110.       i64 offset = (pgno-1)*(i64)pPager->pageSize;   /* Offset to write */

  55111.       char *pData;                                   /* Data to write */    

  55112. 

  55113.       assert( (pList->flags&PGHDR_NEED_SYNC)==0 );

  55114.       if( pList->pgno==1 ) pager_write_changecounter(pList);

  55115. 

  55116.       /* Encode the database */

  55117.       CODEC2(pPager, pList->pData, pgno, 6, return SQLITE_NOMEM_BKPT, pData);

  55118. 

  55119.       /* Write out the page data. */

  55120.       rc = sqlite3OsWrite(pPager->fd, pData, pPager->pageSize, offset);

  55121. 

  55122.       /* If page 1 was just written, update Pager.dbFileVers to match

  55123.       ** the value now stored in the database file. If writing this 

  55124.       ** page caused the database file to grow, update dbFileSize. 

  55125.       */

  55126.       if( pgno==1 ){

  55127.         memcpy(&pPager->dbFileVers, &pData[24], sizeof(pPager->dbFileVers));

  55128.       }

  55129.       if( pgno>pPager->dbFileSize ){

  55130.         pPager->dbFileSize = pgno;

  55131.       }

  55132.       pPager->aStat[PAGER_STAT_WRITE]++;

  55133. 

  55134.       /* Update any backup objects copying the contents of this pager. */

  55135.       sqlite3BackupUpdate(pPager->pBackup, pgno, (u8*)pList->pData);

  55136. 

  55137.       PAGERTRACE(("STORE %d page %d hash(%08x)\n",

  55138.                    PAGERID(pPager), pgno, pager_pagehash(pList)));

  55139.       IOTRACE(("PGOUT %p %d\n", pPager, pgno));

  55140.       PAGER_INCR(sqlite3_pager_writedb_count);

  55141.     }else{

  55142.       PAGERTRACE(("NOSTORE %d page %d\n", PAGERID(pPager), pgno));

  55143.     }

  55144.     pager_set_pagehash(pList);

  55145.     pList = pList->pDirty;

  55146.   }

  55147. 

  55148.   return rc;

  55149. }

  55150. 

  55151. /*

  55152. ** Ensure that the sub-journal file is open. If it is already open, this 

  55153. ** function is a no-op.

  55154. **

  55155. ** SQLITE_OK is returned if everything goes according to plan. An 

  55156. ** SQLITE_IOERR_XXX error code is returned if a call to sqlite3OsOpen() 

  55157. ** fails.

  55158. */

  55159. static int openSubJournal(Pager *pPager){

  55160.   int rc = SQLITE_OK;

  55161.   if( !isOpen(pPager->sjfd) ){

  55162.     const int flags =  SQLITE_OPEN_SUBJOURNAL | SQLITE_OPEN_READWRITE 

  55163.       | SQLITE_OPEN_CREATE | SQLITE_OPEN_EXCLUSIVE 

  55164.       | SQLITE_OPEN_DELETEONCLOSE;

  55165.     int nStmtSpill = sqlite3Config.nStmtSpill;

  55166.     if( pPager->journalMode==PAGER_JOURNALMODE_MEMORY || pPager->subjInMemory ){

  55167.       nStmtSpill = -1;

  55168.     }

  55169.     rc = sqlite3JournalOpen(pPager->pVfs, 0, pPager->sjfd, flags, nStmtSpill);

  55170.   }

  55171.   return rc;

  55172. }

  55173. 

  55174. /*

  55175. ** Append a record of the current state of page pPg to the sub-journal. 

  55176. **

  55177. ** If successful, set the bit corresponding to pPg->pgno in the bitvecs

  55178. ** for all open savepoints before returning.

  55179. **

  55180. ** This function returns SQLITE_OK if everything is successful, an IO

  55181. ** error code if the attempt to write to the sub-journal fails, or 

  55182. ** SQLITE_NOMEM if a malloc fails while setting a bit in a savepoint

  55183. ** bitvec.

  55184. */

  55185. static int subjournalPage(PgHdr *pPg){

  55186.   int rc = SQLITE_OK;

  55187.   Pager *pPager = pPg->pPager;

  55188.   if( pPager->journalMode!=PAGER_JOURNALMODE_OFF ){

  55189. 

  55190.     /* Open the sub-journal, if it has not already been opened */

  55191.     assert( pPager->useJournal );

  55192.     assert( isOpen(pPager->jfd) || pagerUseWal(pPager) );

  55193.     assert( isOpen(pPager->sjfd) || pPager->nSubRec==0 );

  55194.     assert( pagerUseWal(pPager) 

  55195.          || pageInJournal(pPager, pPg) 

  55196.          || pPg->pgno>pPager->dbOrigSize 

  55197.     );

  55198.     rc = openSubJournal(pPager);

  55199. 

  55200.     /* If the sub-journal was opened successfully (or was already open),

  55201.     ** write the journal record into the file.  */

  55202.     if( rc==SQLITE_OK ){

  55203.       void *pData = pPg->pData;

  55204.       i64 offset = (i64)pPager->nSubRec*(4+pPager->pageSize);

  55205.       char *pData2;

  55206. 

  55207. #if SQLITE_HAS_CODEC   

  55208.       if( !pPager->subjInMemory ){

  55209.         CODEC2(pPager, pData, pPg->pgno, 7, return SQLITE_NOMEM_BKPT, pData2);

  55210.       }else

  55211. #endif

  55212.       pData2 = pData;

  55213.       PAGERTRACE(("STMT-JOURNAL %d page %d\n", PAGERID(pPager), pPg->pgno));

  55214.       rc = write32bits(pPager->sjfd, offset, pPg->pgno);

  55215.       if( rc==SQLITE_OK ){

  55216.         rc = sqlite3OsWrite(pPager->sjfd, pData2, pPager->pageSize, offset+4);

  55217.       }

  55218.     }

  55219.   }

  55220.   if( rc==SQLITE_OK ){

  55221.     pPager->nSubRec++;

  55222.     assert( pPager->nSavepoint>0 );

  55223.     rc = addToSavepointBitvecs(pPager, pPg->pgno);

  55224.   }

  55225.   return rc;

  55226. }

  55227. static int subjournalPageIfRequired(PgHdr *pPg){

  55228.   if( subjRequiresPage(pPg) ){

  55229.     return subjournalPage(pPg);

  55230.   }else{

  55231.     return SQLITE_OK;

  55232.   }

  55233. }

  55234. 

  55235. /*

  55236. ** This function is called by the pcache layer when it has reached some

  55237. ** soft memory limit. The first argument is a pointer to a Pager object

  55238. ** (cast as a void*). The pager is always 'purgeable' (not an in-memory

  55239. ** database). The second argument is a reference to a page that is 

  55240. ** currently dirty but has no outstanding references. The page

  55241. ** is always associated with the Pager object passed as the first 

  55242. ** argument.

  55243. **

  55244. ** The job of this function is to make pPg clean by writing its contents

  55245. ** out to the database file, if possible. This may involve syncing the

  55246. ** journal file. 

  55247. **

  55248. ** If successful, sqlite3PcacheMakeClean() is called on the page and

  55249. ** SQLITE_OK returned. If an IO error occurs while trying to make the

  55250. ** page clean, the IO error code is returned. If the page cannot be

  55251. ** made clean for some other reason, but no error occurs, then SQLITE_OK

  55252. ** is returned by sqlite3PcacheMakeClean() is not called.

  55253. */

  55254. static int pagerStress(void *p, PgHdr *pPg){

  55255.   Pager *pPager = (Pager *)p;

  55256.   int rc = SQLITE_OK;

  55257. 

  55258.   assert( pPg->pPager==pPager );

  55259.   assert( pPg->flags&PGHDR_DIRTY );

  55260. 

  55261.   /* The doNotSpill NOSYNC bit is set during times when doing a sync of

  55262.   ** journal (and adding a new header) is not allowed.  This occurs

  55263.   ** during calls to sqlite3PagerWrite() while trying to journal multiple

  55264.   ** pages belonging to the same sector.

  55265.   **

  55266.   ** The doNotSpill ROLLBACK and OFF bits inhibits all cache spilling

  55267.   ** regardless of whether or not a sync is required.  This is set during

  55268.   ** a rollback or by user request, respectively.

  55269.   **

  55270.   ** Spilling is also prohibited when in an error state since that could

  55271.   ** lead to database corruption.   In the current implementation it 

  55272.   ** is impossible for sqlite3PcacheFetch() to be called with createFlag==3

  55273.   ** while in the error state, hence it is impossible for this routine to

  55274.   ** be called in the error state.  Nevertheless, we include a NEVER()

  55275.   ** test for the error state as a safeguard against future changes.

  55276.   */

  55277.   if( NEVER(pPager->errCode) ) return SQLITE_OK;

  55278.   testcase( pPager->doNotSpill & SPILLFLAG_ROLLBACK );

  55279.   testcase( pPager->doNotSpill & SPILLFLAG_OFF );

  55280.   testcase( pPager->doNotSpill & SPILLFLAG_NOSYNC );

  55281.   if( pPager->doNotSpill

  55282.    && ((pPager->doNotSpill & (SPILLFLAG_ROLLBACK|SPILLFLAG_OFF))!=0

  55283.       || (pPg->flags & PGHDR_NEED_SYNC)!=0)

  55284.   ){

  55285.     return SQLITE_OK;

  55286.   }

  55287. 

  55288.   pPager->aStat[PAGER_STAT_SPILL]++;

  55289.   pPg->pDirty = 0;

  55290.   if( pagerUseWal(pPager) ){

  55291.     /* Write a single frame for this page to the log. */

  55292.     rc = subjournalPageIfRequired(pPg); 

  55293.     if( rc==SQLITE_OK ){

  55294.       rc = pagerWalFrames(pPager, pPg, 0, 0);

  55295.     }

  55296.   }else{

  55297.     

  55298. #ifdef SQLITE_ENABLE_BATCH_ATOMIC_WRITE

  55299.     if( pPager->tempFile==0 ){

  55300.       rc = sqlite3JournalCreate(pPager->jfd);

  55301.       if( rc!=SQLITE_OK ) return pager_error(pPager, rc);

  55302.     }

  55303. #endif

  55304.   

  55305.     /* Sync the journal file if required. */

  55306.     if( pPg->flags&PGHDR_NEED_SYNC 

  55307.      || pPager->eState==PAGER_WRITER_CACHEMOD

  55308.     ){

  55309.       rc = syncJournal(pPager, 1);

  55310.     }

  55311.   

  55312.     /* Write the contents of the page out to the database file. */

  55313.     if( rc==SQLITE_OK ){

  55314.       assert( (pPg->flags&PGHDR_NEED_SYNC)==0 );

  55315.       rc = pager_write_pagelist(pPager, pPg);

  55316.     }

  55317.   }

  55318. 

  55319.   /* Mark the page as clean. */

  55320.   if( rc==SQLITE_OK ){

  55321.     PAGERTRACE(("STRESS %d page %d\n", PAGERID(pPager), pPg->pgno));

  55322.     sqlite3PcacheMakeClean(pPg);

  55323.   }

  55324. 

  55325.   return pager_error(pPager, rc); 

  55326. }

  55327. 

  55328. /*

  55329. ** Flush all unreferenced dirty pages to disk.

  55330. */

  55331. SQLITE_PRIVATE int sqlite3PagerFlush(Pager *pPager){

  55332.   int rc = pPager->errCode;

  55333.   if( !MEMDB ){

  55334.     PgHdr *pList = sqlite3PcacheDirtyList(pPager->pPCache);

  55335.     assert( assert_pager_state(pPager) );

  55336.     while( rc==SQLITE_OK && pList ){

  55337.       PgHdr *pNext = pList->pDirty;

  55338.       if( pList->nRef==0 ){

  55339.         rc = pagerStress((void*)pPager, pList);

  55340.       }

  55341.       pList = pNext;

  55342.     }

  55343.   }

  55344. 

  55345.   return rc;

  55346. }

  55347. 

  55348. /*

  55349. ** Allocate and initialize a new Pager object and put a pointer to it

  55350. ** in *ppPager. The pager should eventually be freed by passing it

  55351. ** to sqlite3PagerClose().

  55352. **

  55353. ** The zFilename argument is the path to the database file to open.

  55354. ** If zFilename is NULL then a randomly-named temporary file is created

  55355. ** and used as the file to be cached. Temporary files are be deleted

  55356. ** automatically when they are closed. If zFilename is ":memory:" then 

  55357. ** all information is held in cache. It is never written to disk. 

  55358. ** This can be used to implement an in-memory database.

  55359. **

  55360. ** The nExtra parameter specifies the number of bytes of space allocated

  55361. ** along with each page reference. This space is available to the user

  55362. ** via the sqlite3PagerGetExtra() API.  When a new page is allocated, the

  55363. ** first 8 bytes of this space are zeroed but the remainder is uninitialized.

  55364. ** (The extra space is used by btree as the MemPage object.)

  55365. **

  55366. ** The flags argument is used to specify properties that affect the

  55367. ** operation of the pager. It should be passed some bitwise combination

  55368. ** of the PAGER_* flags.

  55369. **

  55370. ** The vfsFlags parameter is a bitmask to pass to the flags parameter

  55371. ** of the xOpen() method of the supplied VFS when opening files. 

  55372. **

  55373. ** If the pager object is allocated and the specified file opened 

  55374. ** successfully, SQLITE_OK is returned and *ppPager set to point to

  55375. ** the new pager object. If an error occurs, *ppPager is set to NULL

  55376. ** and error code returned. This function may return SQLITE_NOMEM

  55377. ** (sqlite3Malloc() is used to allocate memory), SQLITE_CANTOPEN or 

  55378. ** various SQLITE_IO_XXX errors.

  55379. */

  55380. SQLITE_PRIVATE int sqlite3PagerOpen(

  55381.   sqlite3_vfs *pVfs,       /* The virtual file system to use */

  55382.   Pager **ppPager,         /* OUT: Return the Pager structure here */

  55383.   const char *zFilename,   /* Name of the database file to open */

  55384.   int nExtra,              /* Extra bytes append to each in-memory page */

  55385.   int flags,               /* flags controlling this file */

  55386.   int vfsFlags,            /* flags passed through to sqlite3_vfs.xOpen() */

  55387.   void (*xReinit)(DbPage*) /* Function to reinitialize pages */

  55388. ){

  55389.   u8 *pPtr;

  55390.   Pager *pPager = 0;       /* Pager object to allocate and return */

  55391.   int rc = SQLITE_OK;      /* Return code */

  55392.   int tempFile = 0;        /* True for temp files (incl. in-memory files) */

  55393.   int memDb = 0;           /* True if this is an in-memory file */

  55394. #ifdef SQLITE_ENABLE_DESERIALIZE

  55395.   int memJM = 0;           /* Memory journal mode */

  55396. #else

  55397. # define memJM 0

  55398. #endif

  55399.   int readOnly = 0;        /* True if this is a read-only file */

  55400.   int journalFileSize;     /* Bytes to allocate for each journal fd */

  55401.   char *zPathname = 0;     /* Full path to database file */

  55402.   int nPathname = 0;       /* Number of bytes in zPathname */

  55403.   int useJournal = (flags & PAGER_OMIT_JOURNAL)==0; /* False to omit journal */

  55404.   int pcacheSize = sqlite3PcacheSize();       /* Bytes to allocate for PCache */

  55405.   u32 szPageDflt = SQLITE_DEFAULT_PAGE_SIZE;  /* Default page size */

  55406.   const char *zUri = 0;    /* URI args to copy */

  55407.   int nUri = 0;            /* Number of bytes of URI args at *zUri */

  55408. 

  55409.   /* Figure out how much space is required for each journal file-handle

  55410.   ** (there are two of them, the main journal and the sub-journal).  */

  55411.   journalFileSize = ROUND8(sqlite3JournalSize(pVfs));

  55412. 

  55413.   /* Set the output variable to NULL in case an error occurs. */

  55414.   *ppPager = 0;

  55415. 

  55416. #ifndef SQLITE_OMIT_MEMORYDB

  55417.   if( flags & PAGER_MEMORY ){

  55418.     memDb = 1;

  55419.     if( zFilename && zFilename[0] ){

  55420.       zPathname = sqlite3DbStrDup(0, zFilename);

  55421.       if( zPathname==0  ) return SQLITE_NOMEM_BKPT;

  55422.       nPathname = sqlite3Strlen30(zPathname);

  55423.       zFilename = 0;

  55424.     }

  55425.   }

  55426. #endif

  55427. 

  55428.   /* Compute and store the full pathname in an allocated buffer pointed

  55429.   ** to by zPathname, length nPathname. Or, if this is a temporary file,

  55430.   ** leave both nPathname and zPathname set to 0.

  55431.   */

  55432.   if( zFilename && zFilename[0] ){

  55433.     const char *z;

  55434.     nPathname = pVfs->mxPathname+1;

  55435.     zPathname = sqlite3DbMallocRaw(0, nPathname*2);

  55436.     if( zPathname==0 ){

  55437.       return SQLITE_NOMEM_BKPT;

  55438.     }

  55439.     zPathname[0] = 0; /* Make sure initialized even if FullPathname() fails */

  55440.     rc = sqlite3OsFullPathname(pVfs, zFilename, nPathname, zPathname);

  55441.     nPathname = sqlite3Strlen30(zPathname);

  55442.     z = zUri = &zFilename[sqlite3Strlen30(zFilename)+1];

  55443.     while( *z ){

  55444.       z += sqlite3Strlen30(z)+1;

  55445.       z += sqlite3Strlen30(z)+1;

  55446.     }

  55447.     nUri = (int)(&z[1] - zUri);

  55448.     assert( nUri>=0 );

  55449.     if( rc==SQLITE_OK && nPathname+8>pVfs->mxPathname ){

  55450.       /* This branch is taken when the journal path required by

  55451.       ** the database being opened will be more than pVfs->mxPathname

  55452.       ** bytes in length. This means the database cannot be opened,

  55453.       ** as it will not be possible to open the journal file or even

  55454.       ** check for a hot-journal before reading.

  55455.       */

  55456.       rc = SQLITE_CANTOPEN_BKPT;

  55457.     }

  55458.     if( rc!=SQLITE_OK ){

  55459.       sqlite3DbFree(0, zPathname);

  55460.       return rc;

  55461.     }

  55462.   }

  55463. 

  55464.   /* Allocate memory for the Pager structure, PCache object, the

  55465.   ** three file descriptors, the database file name and the journal 

  55466.   ** file name. The layout in memory is as follows:

  55467.   **

  55468.   **     Pager object                    (sizeof(Pager) bytes)

  55469.   **     PCache object                   (sqlite3PcacheSize() bytes)

  55470.   **     Database file handle            (pVfs->szOsFile bytes)

  55471.   **     Sub-journal file handle         (journalFileSize bytes)

  55472.   **     Main journal file handle        (journalFileSize bytes)

  55473.   **     Database file name              (nPathname+1 bytes)

  55474.   **     Journal file name               (nPathname+8+1 bytes)

  55475.   */

  55476.   pPtr = (u8 *)sqlite3MallocZero(

  55477.     ROUND8(sizeof(*pPager)) +      /* Pager structure */

  55478.     ROUND8(pcacheSize) +           /* PCache object */

  55479.     ROUND8(pVfs->szOsFile) +       /* The main db file */

  55480.     journalFileSize * 2 +          /* The two journal files */ 

  55481.     nPathname + 1 + nUri +         /* zFilename */

  55482.     nPathname + 8 + 2              /* zJournal */

  55483. #ifndef SQLITE_OMIT_WAL

  55484.     + nPathname + 4 + 2            /* zWal */

  55485. #endif

  55486.   );

  55487.   assert( EIGHT_BYTE_ALIGNMENT(SQLITE_INT_TO_PTR(journalFileSize)) );

  55488.   if( !pPtr ){

  55489.     sqlite3DbFree(0, zPathname);

  55490.     return SQLITE_NOMEM_BKPT;

  55491.   }

  55492.   pPager =              (Pager*)(pPtr);

  55493.   pPager->pPCache =    (PCache*)(pPtr += ROUND8(sizeof(*pPager)));

  55494.   pPager->fd =   (sqlite3_file*)(pPtr += ROUND8(pcacheSize));

  55495.   pPager->sjfd = (sqlite3_file*)(pPtr += ROUND8(pVfs->szOsFile));

  55496.   pPager->jfd =  (sqlite3_file*)(pPtr += journalFileSize);

  55497.   pPager->zFilename =    (char*)(pPtr += journalFileSize);

  55498.   assert( EIGHT_BYTE_ALIGNMENT(pPager->jfd) );

  55499. 

  55500.   /* Fill in the Pager.zFilename and Pager.zJournal buffers, if required. */

  55501.   if( zPathname ){

  55502.     assert( nPathname>0 );

  55503.     pPager->zJournal =   (char*)(pPtr += nPathname + 1 + nUri);

  55504.     memcpy(pPager->zFilename, zPathname, nPathname);

  55505.     if( nUri ) memcpy(&pPager->zFilename[nPathname+1], zUri, nUri);

  55506.     memcpy(pPager->zJournal, zPathname, nPathname);

  55507.     memcpy(&pPager->zJournal[nPathname], "-journal\000", 8+2);

  55508.     sqlite3FileSuffix3(pPager->zFilename, pPager->zJournal);

  55509. #ifndef SQLITE_OMIT_WAL

  55510.     pPager->zWal = &pPager->zJournal[nPathname+8+1];

  55511.     memcpy(pPager->zWal, zPathname, nPathname);

  55512.     memcpy(&pPager->zWal[nPathname], "-wal\000", 4+1);

  55513.     sqlite3FileSuffix3(pPager->zFilename, pPager->zWal);

  55514. #endif

  55515.     sqlite3DbFree(0, zPathname);

  55516.   }

  55517.   pPager->pVfs = pVfs;

  55518.   pPager->vfsFlags = vfsFlags;

  55519. 

  55520.   /* Open the pager file.

  55521.   */

  55522.   if( zFilename && zFilename[0] ){

  55523.     int fout = 0;                    /* VFS flags returned by xOpen() */

  55524.     rc = sqlite3OsOpen(pVfs, pPager->zFilename, pPager->fd, vfsFlags, &fout);

  55525.     assert( !memDb );

  55526. #ifdef SQLITE_ENABLE_DESERIALIZE

  55527.     memJM = (fout&SQLITE_OPEN_MEMORY)!=0;

  55528. #endif

  55529.     readOnly = (fout&SQLITE_OPEN_READONLY)!=0;

  55530. 

  55531.     /* If the file was successfully opened for read/write access,

  55532.     ** choose a default page size in case we have to create the

  55533.     ** database file. The default page size is the maximum of:

  55534.     **

  55535.     **    + SQLITE_DEFAULT_PAGE_SIZE,

  55536.     **    + The value returned by sqlite3OsSectorSize()

  55537.     **    + The largest page size that can be written atomically.

  55538.     */

  55539.     if( rc==SQLITE_OK ){

  55540.       int iDc = sqlite3OsDeviceCharacteristics(pPager->fd);

  55541.       if( !readOnly ){

  55542.         setSectorSize(pPager);

  55543.         assert(SQLITE_DEFAULT_PAGE_SIZE<=SQLITE_MAX_DEFAULT_PAGE_SIZE);

  55544.         if( szPageDflt<pPager->sectorSize ){

  55545.           if( pPager->sectorSize>SQLITE_MAX_DEFAULT_PAGE_SIZE ){

  55546.             szPageDflt = SQLITE_MAX_DEFAULT_PAGE_SIZE;

  55547.           }else{

  55548.             szPageDflt = (u32)pPager->sectorSize;

  55549.           }

  55550.         }

  55551. #ifdef SQLITE_ENABLE_ATOMIC_WRITE

  55552.         {

  55553.           int ii;

  55554.           assert(SQLITE_IOCAP_ATOMIC512==(512>>8));

  55555.           assert(SQLITE_IOCAP_ATOMIC64K==(65536>>8));

  55556.           assert(SQLITE_MAX_DEFAULT_PAGE_SIZE<=65536);

  55557.           for(ii=szPageDflt; ii<=SQLITE_MAX_DEFAULT_PAGE_SIZE; ii=ii*2){

  55558.             if( iDc&(SQLITE_IOCAP_ATOMIC|(ii>>8)) ){

  55559.               szPageDflt = ii;

  55560.             }

  55561.           }

  55562.         }

  55563. #endif

  55564.       }

  55565.       pPager->noLock = sqlite3_uri_boolean(zFilename, "nolock", 0);

  55566.       if( (iDc & SQLITE_IOCAP_IMMUTABLE)!=0

  55567.        || sqlite3_uri_boolean(zFilename, "immutable", 0) ){

  55568.           vfsFlags |= SQLITE_OPEN_READONLY;

  55569.           goto act_like_temp_file;

  55570.       }

  55571.     }

  55572.   }else{

  55573.     /* If a temporary file is requested, it is not opened immediately.

  55574.     ** In this case we accept the default page size and delay actually

  55575.     ** opening the file until the first call to OsWrite().

  55576.     **

  55577.     ** This branch is also run for an in-memory database. An in-memory

  55578.     ** database is the same as a temp-file that is never written out to

  55579.     ** disk and uses an in-memory rollback journal.

  55580.     **

  55581.     ** This branch also runs for files marked as immutable.

  55582.     */ 

  55583. act_like_temp_file:

  55584.     tempFile = 1;

  55585.     pPager->eState = PAGER_READER;     /* Pretend we already have a lock */

  55586.     pPager->eLock = EXCLUSIVE_LOCK;    /* Pretend we are in EXCLUSIVE mode */

  55587.     pPager->noLock = 1;                /* Do no locking */

  55588.     readOnly = (vfsFlags&SQLITE_OPEN_READONLY);

  55589.   }

  55590. 

  55591.   /* The following call to PagerSetPagesize() serves to set the value of 

  55592.   ** Pager.pageSize and to allocate the Pager.pTmpSpace buffer.

  55593.   */

  55594.   if( rc==SQLITE_OK ){

  55595.     assert( pPager->memDb==0 );

  55596.     rc = sqlite3PagerSetPagesize(pPager, &szPageDflt, -1);

  55597.     testcase( rc!=SQLITE_OK );

  55598.   }

  55599. 

  55600.   /* Initialize the PCache object. */

  55601.   if( rc==SQLITE_OK ){

  55602.     nExtra = ROUND8(nExtra);

  55603.     assert( nExtra>=8 && nExtra<1000 );

  55604.     rc = sqlite3PcacheOpen(szPageDflt, nExtra, !memDb,

  55605.                        !memDb?pagerStress:0, (void *)pPager, pPager->pPCache);

  55606.   }

  55607. 

  55608.   /* If an error occurred above, free the  Pager structure and close the file.

  55609.   */

  55610.   if( rc!=SQLITE_OK ){

  55611.     sqlite3OsClose(pPager->fd);

  55612.     sqlite3PageFree(pPager->pTmpSpace);

  55613.     sqlite3_free(pPager);

  55614.     return rc;

  55615.   }

  55616. 

  55617.   PAGERTRACE(("OPEN %d %s\n", FILEHANDLEID(pPager->fd), pPager->zFilename));

  55618.   IOTRACE(("OPEN %p %s\n", pPager, pPager->zFilename))

  55619. 

  55620.   pPager->useJournal = (u8)useJournal;

  55621.   /* pPager->stmtOpen = 0; */

  55622.   /* pPager->stmtInUse = 0; */

  55623.   /* pPager->nRef = 0; */

  55624.   /* pPager->stmtSize = 0; */

  55625.   /* pPager->stmtJSize = 0; */

  55626.   /* pPager->nPage = 0; */

  55627.   pPager->mxPgno = SQLITE_MAX_PAGE_COUNT;

  55628.   /* pPager->state = PAGER_UNLOCK; */

  55629.   /* pPager->errMask = 0; */

  55630.   pPager->tempFile = (u8)tempFile;

  55631.   assert( tempFile==PAGER_LOCKINGMODE_NORMAL 

  55632.           || tempFile==PAGER_LOCKINGMODE_EXCLUSIVE );

  55633.   assert( PAGER_LOCKINGMODE_EXCLUSIVE==1 );

  55634.   pPager->exclusiveMode = (u8)tempFile; 

  55635.   pPager->changeCountDone = pPager->tempFile;

  55636.   pPager->memDb = (u8)memDb;

  55637.   pPager->readOnly = (u8)readOnly;

  55638.   assert( useJournal || pPager->tempFile );

  55639.   pPager->noSync = pPager->tempFile;

  55640.   if( pPager->noSync ){

  55641.     assert( pPager->fullSync==0 );

  55642.     assert( pPager->extraSync==0 );

  55643.     assert( pPager->syncFlags==0 );

  55644.     assert( pPager->walSyncFlags==0 );

  55645.   }else{

  55646.     pPager->fullSync = 1;

  55647.     pPager->extraSync = 0;

  55648.     pPager->syncFlags = SQLITE_SYNC_NORMAL;

  55649.     pPager->walSyncFlags = SQLITE_SYNC_NORMAL | (SQLITE_SYNC_NORMAL<<2);

  55650.   }

  55651.   /* pPager->pFirst = 0; */

  55652.   /* pPager->pFirstSynced = 0; */

  55653.   /* pPager->pLast = 0; */

  55654.   pPager->nExtra = (u16)nExtra;

  55655.   pPager->journalSizeLimit = SQLITE_DEFAULT_JOURNAL_SIZE_LIMIT;

  55656.   assert( isOpen(pPager->fd) || tempFile );

  55657.   setSectorSize(pPager);

  55658.   if( !useJournal ){

  55659.     pPager->journalMode = PAGER_JOURNALMODE_OFF;

  55660.   }else if( memDb || memJM ){

  55661.     pPager->journalMode = PAGER_JOURNALMODE_MEMORY;

  55662.   }

  55663.   /* pPager->xBusyHandler = 0; */

  55664.   /* pPager->pBusyHandlerArg = 0; */

  55665.   pPager->xReiniter = xReinit;

  55666.   setGetterMethod(pPager);

  55667.   /* memset(pPager->aHash, 0, sizeof(pPager->aHash)); */

  55668.   /* pPager->szMmap = SQLITE_DEFAULT_MMAP_SIZE // will be set by btree.c */

  55669. 

  55670.   *ppPager = pPager;

  55671.   return SQLITE_OK;

  55672. }

  55673. 

  55674. 

  55675. 

  55676. /*

  55677. ** This function is called after transitioning from PAGER_UNLOCK to

  55678. ** PAGER_SHARED state. It tests if there is a hot journal present in

  55679. ** the file-system for the given pager. A hot journal is one that 

  55680. ** needs to be played back. According to this function, a hot-journal

  55681. ** file exists if the following criteria are met:

  55682. **

  55683. **   * The journal file exists in the file system, and

  55684. **   * No process holds a RESERVED or greater lock on the database file, and

  55685. **   * The database file itself is greater than 0 bytes in size, and

  55686. **   * The first byte of the journal file exists and is not 0x00.

  55687. **

  55688. ** If the current size of the database file is 0 but a journal file

  55689. ** exists, that is probably an old journal left over from a prior

  55690. ** database with the same name. In this case the journal file is

  55691. ** just deleted using OsDelete, *pExists is set to 0 and SQLITE_OK

  55692. ** is returned.

  55693. **

  55694. ** This routine does not check if there is a master journal filename

  55695. ** at the end of the file. If there is, and that master journal file

  55696. ** does not exist, then the journal file is not really hot. In this

  55697. ** case this routine will return a false-positive. The pager_playback()

  55698. ** routine will discover that the journal file is not really hot and 

  55699. ** will not roll it back. 

  55700. **

  55701. ** If a hot-journal file is found to exist, *pExists is set to 1 and 

  55702. ** SQLITE_OK returned. If no hot-journal file is present, *pExists is

  55703. ** set to 0 and SQLITE_OK returned. If an IO error occurs while trying

  55704. ** to determine whether or not a hot-journal file exists, the IO error

  55705. ** code is returned and the value of *pExists is undefined.

  55706. */

  55707. static int hasHotJournal(Pager *pPager, int *pExists){

  55708.   sqlite3_vfs * const pVfs = pPager->pVfs;

  55709.   int rc = SQLITE_OK;           /* Return code */

  55710.   int exists = 1;               /* True if a journal file is present */

  55711.   int jrnlOpen = !!isOpen(pPager->jfd);

  55712. 

  55713.   assert( pPager->useJournal );

  55714.   assert( isOpen(pPager->fd) );

  55715.   assert( pPager->eState==PAGER_OPEN );

  55716. 

  55717.   assert( jrnlOpen==0 || ( sqlite3OsDeviceCharacteristics(pPager->jfd) &

  55718.     SQLITE_IOCAP_UNDELETABLE_WHEN_OPEN

  55719.   ));

  55720. 

  55721.   *pExists = 0;

  55722.   if( !jrnlOpen ){

  55723.     rc = sqlite3OsAccess(pVfs, pPager->zJournal, SQLITE_ACCESS_EXISTS, &exists);

  55724.   }

  55725.   if( rc==SQLITE_OK && exists ){

  55726.     int locked = 0;             /* True if some process holds a RESERVED lock */

  55727. 

  55728.     /* Race condition here:  Another process might have been holding the

  55729.     ** the RESERVED lock and have a journal open at the sqlite3OsAccess() 

  55730.     ** call above, but then delete the journal and drop the lock before

  55731.     ** we get to the following sqlite3OsCheckReservedLock() call.  If that

  55732.     ** is the case, this routine might think there is a hot journal when

  55733.     ** in fact there is none.  This results in a false-positive which will

  55734.     ** be dealt with by the playback routine.  Ticket #3883.

  55735.     */

  55736.     rc = sqlite3OsCheckReservedLock(pPager->fd, &locked);

  55737.     if( rc==SQLITE_OK && !locked ){

  55738.       Pgno nPage;                 /* Number of pages in database file */

  55739. 

  55740.       assert( pPager->tempFile==0 );

  55741.       rc = pagerPagecount(pPager, &nPage);

  55742.       if( rc==SQLITE_OK ){

  55743.         /* If the database is zero pages in size, that means that either (1) the

  55744.         ** journal is a remnant from a prior database with the same name where

  55745.         ** the database file but not the journal was deleted, or (2) the initial

  55746.         ** transaction that populates a new database is being rolled back.

  55747.         ** In either case, the journal file can be deleted.  However, take care

  55748.         ** not to delete the journal file if it is already open due to

  55749.         ** journal_mode=PERSIST.

  55750.         */

  55751.         if( nPage==0 && !jrnlOpen ){

  55752.           sqlite3BeginBenignMalloc();

  55753.           if( pagerLockDb(pPager, RESERVED_LOCK)==SQLITE_OK ){

  55754.             sqlite3OsDelete(pVfs, pPager->zJournal, 0);

  55755.             if( !pPager->exclusiveMode ) pagerUnlockDb(pPager, SHARED_LOCK);

  55756.           }

  55757.           sqlite3EndBenignMalloc();

  55758.         }else{

  55759.           /* The journal file exists and no other connection has a reserved

  55760.           ** or greater lock on the database file. Now check that there is

  55761.           ** at least one non-zero bytes at the start of the journal file.

  55762.           ** If there is, then we consider this journal to be hot. If not, 

  55763.           ** it can be ignored.

  55764.           */

  55765.           if( !jrnlOpen ){

  55766.             int f = SQLITE_OPEN_READONLY|SQLITE_OPEN_MAIN_JOURNAL;

  55767.             rc = sqlite3OsOpen(pVfs, pPager->zJournal, pPager->jfd, f, &f);

  55768.           }

  55769.           if( rc==SQLITE_OK ){

  55770.             u8 first = 0;

  55771.             rc = sqlite3OsRead(pPager->jfd, (void *)&first, 1, 0);

  55772.             if( rc==SQLITE_IOERR_SHORT_READ ){

  55773.               rc = SQLITE_OK;

  55774.             }

  55775.             if( !jrnlOpen ){

  55776.               sqlite3OsClose(pPager->jfd);

  55777.             }

  55778.             *pExists = (first!=0);

  55779.           }else if( rc==SQLITE_CANTOPEN ){

  55780.             /* If we cannot open the rollback journal file in order to see if

  55781.             ** it has a zero header, that might be due to an I/O error, or

  55782.             ** it might be due to the race condition described above and in

  55783.             ** ticket #3883.  Either way, assume that the journal is hot.

  55784.             ** This might be a false positive.  But if it is, then the

  55785.             ** automatic journal playback and recovery mechanism will deal

  55786.             ** with it under an EXCLUSIVE lock where we do not need to

  55787.             ** worry so much with race conditions.

  55788.             */

  55789.             *pExists = 1;

  55790.             rc = SQLITE_OK;

  55791.           }

  55792.         }

  55793.       }

  55794.     }

  55795.   }

  55796. 

  55797.   return rc;

  55798. }

  55799. 

  55800. /*

  55801. ** This function is called to obtain a shared lock on the database file.

  55802. ** It is illegal to call sqlite3PagerGet() until after this function

  55803. ** has been successfully called. If a shared-lock is already held when

  55804. ** this function is called, it is a no-op.

  55805. **

  55806. ** The following operations are also performed by this function.

  55807. **

  55808. **   1) If the pager is currently in PAGER_OPEN state (no lock held

  55809. **      on the database file), then an attempt is made to obtain a

  55810. **      SHARED lock on the database file. Immediately after obtaining

  55811. **      the SHARED lock, the file-system is checked for a hot-journal,

  55812. **      which is played back if present. Following any hot-journal 

  55813. **      rollback, the contents of the cache are validated by checking

  55814. **      the 'change-counter' field of the database file header and

  55815. **      discarded if they are found to be invalid.

  55816. **

  55817. **   2) If the pager is running in exclusive-mode, and there are currently

  55818. **      no outstanding references to any pages, and is in the error state,

  55819. **      then an attempt is made to clear the error state by discarding

  55820. **      the contents of the page cache and rolling back any open journal

  55821. **      file.

  55822. **

  55823. ** If everything is successful, SQLITE_OK is returned. If an IO error 

  55824. ** occurs while locking the database, checking for a hot-journal file or 

  55825. ** rolling back a journal file, the IO error code is returned.

  55826. */

  55827. SQLITE_PRIVATE int sqlite3PagerSharedLock(Pager *pPager){

  55828.   int rc = SQLITE_OK;                /* Return code */

  55829. 

  55830.   /* This routine is only called from b-tree and only when there are no

  55831.   ** outstanding pages. This implies that the pager state should either

  55832.   ** be OPEN or READER. READER is only possible if the pager is or was in 

  55833.   ** exclusive access mode.  */

  55834.   assert( sqlite3PcacheRefCount(pPager->pPCache)==0 );

  55835.   assert( assert_pager_state(pPager) );

  55836.   assert( pPager->eState==PAGER_OPEN || pPager->eState==PAGER_READER );

  55837.   assert( pPager->errCode==SQLITE_OK );

  55838. 

  55839.   if( !pagerUseWal(pPager) && pPager->eState==PAGER_OPEN ){

  55840.     int bHotJournal = 1;          /* True if there exists a hot journal-file */

  55841. 

  55842.     assert( !MEMDB );

  55843.     assert( pPager->tempFile==0 || pPager->eLock==EXCLUSIVE_LOCK );

  55844. 

  55845.     rc = pager_wait_on_lock(pPager, SHARED_LOCK);

  55846.     if( rc!=SQLITE_OK ){

  55847.       assert( pPager->eLock==NO_LOCK || pPager->eLock==UNKNOWN_LOCK );

  55848.       goto failed;

  55849.     }

  55850. 

  55851.     /* If a journal file exists, and there is no RESERVED lock on the

  55852.     ** database file, then it either needs to be played back or deleted.

  55853.     */

  55854.     if( pPager->eLock<=SHARED_LOCK ){

  55855.       rc = hasHotJournal(pPager, &bHotJournal);

  55856.     }

  55857.     if( rc!=SQLITE_OK ){

  55858.       goto failed;

  55859.     }

  55860.     if( bHotJournal ){

  55861.       if( pPager->readOnly ){

  55862.         rc = SQLITE_READONLY_ROLLBACK;

  55863.         goto failed;

  55864.       }

  55865. 

  55866.       /* Get an EXCLUSIVE lock on the database file. At this point it is

  55867.       ** important that a RESERVED lock is not obtained on the way to the

  55868.       ** EXCLUSIVE lock. If it were, another process might open the

  55869.       ** database file, detect the RESERVED lock, and conclude that the

  55870.       ** database is safe to read while this process is still rolling the 

  55871.       ** hot-journal back.

  55872.       ** 

  55873.       ** Because the intermediate RESERVED lock is not requested, any

  55874.       ** other process attempting to access the database file will get to 

  55875.       ** this point in the code and fail to obtain its own EXCLUSIVE lock 

  55876.       ** on the database file.

  55877.       **

  55878.       ** Unless the pager is in locking_mode=exclusive mode, the lock is

  55879.       ** downgraded to SHARED_LOCK before this function returns.

  55880.       */

  55881.       rc = pagerLockDb(pPager, EXCLUSIVE_LOCK);

  55882.       if( rc!=SQLITE_OK ){

  55883.         goto failed;

  55884.       }

  55885.  

  55886.       /* If it is not already open and the file exists on disk, open the 

  55887.       ** journal for read/write access. Write access is required because 

  55888.       ** in exclusive-access mode the file descriptor will be kept open 

  55889.       ** and possibly used for a transaction later on. Also, write-access 

  55890.       ** is usually required to finalize the journal in journal_mode=persist 

  55891.       ** mode (and also for journal_mode=truncate on some systems).

  55892.       **

  55893.       ** If the journal does not exist, it usually means that some 

  55894.       ** other connection managed to get in and roll it back before 

  55895.       ** this connection obtained the exclusive lock above. Or, it 

  55896.       ** may mean that the pager was in the error-state when this

  55897.       ** function was called and the journal file does not exist.

  55898.       */

  55899.       if( !isOpen(pPager->jfd) ){

  55900.         sqlite3_vfs * const pVfs = pPager->pVfs;

  55901.         int bExists;              /* True if journal file exists */

  55902.         rc = sqlite3OsAccess(

  55903.             pVfs, pPager->zJournal, SQLITE_ACCESS_EXISTS, &bExists);

  55904.         if( rc==SQLITE_OK && bExists ){

  55905.           int fout = 0;

  55906.           int f = SQLITE_OPEN_READWRITE|SQLITE_OPEN_MAIN_JOURNAL;

  55907.           assert( !pPager->tempFile );

  55908.           rc = sqlite3OsOpen(pVfs, pPager->zJournal, pPager->jfd, f, &fout);

  55909.           assert( rc!=SQLITE_OK || isOpen(pPager->jfd) );

  55910.           if( rc==SQLITE_OK && fout&SQLITE_OPEN_READONLY ){

  55911.             rc = SQLITE_CANTOPEN_BKPT;

  55912.             sqlite3OsClose(pPager->jfd);

  55913.           }

  55914.         }

  55915.       }

  55916.  

  55917.       /* Playback and delete the journal.  Drop the database write

  55918.       ** lock and reacquire the read lock. Purge the cache before

  55919.       ** playing back the hot-journal so that we don't end up with

  55920.       ** an inconsistent cache.  Sync the hot journal before playing

  55921.       ** it back since the process that crashed and left the hot journal

  55922.       ** probably did not sync it and we are required to always sync

  55923.       ** the journal before playing it back.

  55924.       */

  55925.       if( isOpen(pPager->jfd) ){

  55926.         assert( rc==SQLITE_OK );

  55927.         rc = pagerSyncHotJournal(pPager);

  55928.         if( rc==SQLITE_OK ){

  55929.           rc = pager_playback(pPager, !pPager->tempFile);

  55930.           pPager->eState = PAGER_OPEN;

  55931.         }

  55932.       }else if( !pPager->exclusiveMode ){

  55933.         pagerUnlockDb(pPager, SHARED_LOCK);

  55934.       }

  55935. 

  55936.       if( rc!=SQLITE_OK ){

  55937.         /* This branch is taken if an error occurs while trying to open

  55938.         ** or roll back a hot-journal while holding an EXCLUSIVE lock. The

  55939.         ** pager_unlock() routine will be called before returning to unlock

  55940.         ** the file. If the unlock attempt fails, then Pager.eLock must be

  55941.         ** set to UNKNOWN_LOCK (see the comment above the #define for 

  55942.         ** UNKNOWN_LOCK above for an explanation). 

  55943.         **

  55944.         ** In order to get pager_unlock() to do this, set Pager.eState to

  55945.         ** PAGER_ERROR now. This is not actually counted as a transition

  55946.         ** to ERROR state in the state diagram at the top of this file,

  55947.         ** since we know that the same call to pager_unlock() will very

  55948.         ** shortly transition the pager object to the OPEN state. Calling

  55949.         ** assert_pager_state() would fail now, as it should not be possible

  55950.         ** to be in ERROR state when there are zero outstanding page 

  55951.         ** references.

  55952.         */

  55953.         pager_error(pPager, rc);

  55954.         goto failed;

  55955.       }

  55956. 

  55957.       assert( pPager->eState==PAGER_OPEN );

  55958.       assert( (pPager->eLock==SHARED_LOCK)

  55959.            || (pPager->exclusiveMode && pPager->eLock>SHARED_LOCK)

  55960.       );

  55961.     }

  55962. 

  55963.     if( !pPager->tempFile && pPager->hasHeldSharedLock ){

  55964.       /* The shared-lock has just been acquired then check to

  55965.       ** see if the database has been modified.  If the database has changed,

  55966.       ** flush the cache.  The hasHeldSharedLock flag prevents this from

  55967.       ** occurring on the very first access to a file, in order to save a

  55968.       ** single unnecessary sqlite3OsRead() call at the start-up.

  55969.       **

  55970.       ** Database changes are detected by looking at 15 bytes beginning

  55971.       ** at offset 24 into the file.  The first 4 of these 16 bytes are

  55972.       ** a 32-bit counter that is incremented with each change.  The

  55973.       ** other bytes change randomly with each file change when

  55974.       ** a codec is in use.

  55975.       ** 

  55976.       ** There is a vanishingly small chance that a change will not be 

  55977.       ** detected.  The chance of an undetected change is so small that

  55978.       ** it can be neglected.

  55979.       */

  55980.       char dbFileVers[sizeof(pPager->dbFileVers)];

  55981. 

  55982.       IOTRACE(("CKVERS %p %d\n", pPager, sizeof(dbFileVers)));

  55983.       rc = sqlite3OsRead(pPager->fd, &dbFileVers, sizeof(dbFileVers), 24);

  55984.       if( rc!=SQLITE_OK ){

  55985.         if( rc!=SQLITE_IOERR_SHORT_READ ){

  55986.           goto failed;

  55987.         }

  55988.         memset(dbFileVers, 0, sizeof(dbFileVers));

  55989.       }

  55990. 

  55991.       if( memcmp(pPager->dbFileVers, dbFileVers, sizeof(dbFileVers))!=0 ){

  55992.         pager_reset(pPager);

  55993. 

  55994.         /* Unmap the database file. It is possible that external processes

  55995.         ** may have truncated the database file and then extended it back

  55996.         ** to its original size while this process was not holding a lock.

  55997.         ** In this case there may exist a Pager.pMap mapping that appears

  55998.         ** to be the right size but is not actually valid. Avoid this

  55999.         ** possibility by unmapping the db here. */

  56000.         if( USEFETCH(pPager) ){

  56001.           sqlite3OsUnfetch(pPager->fd, 0, 0);

  56002.         }

  56003.       }

  56004.     }

  56005. 

  56006.     /* If there is a WAL file in the file-system, open this database in WAL

  56007.     ** mode. Otherwise, the following function call is a no-op.

  56008.     */

  56009.     rc = pagerOpenWalIfPresent(pPager);

  56010. #ifndef SQLITE_OMIT_WAL

  56011.     assert( pPager->pWal==0 || rc==SQLITE_OK );

  56012. #endif

  56013.   }

  56014. 

  56015.   if( pagerUseWal(pPager) ){

  56016.     assert( rc==SQLITE_OK );

  56017.     rc = pagerBeginReadTransaction(pPager);

  56018.   }

  56019. 

  56020.   if( pPager->tempFile==0 && pPager->eState==PAGER_OPEN && rc==SQLITE_OK ){

  56021.     rc = pagerPagecount(pPager, &pPager->dbSize);

  56022.   }

  56023. 

  56024.  failed:

  56025.   if( rc!=SQLITE_OK ){

  56026.     assert( !MEMDB );

  56027.     pager_unlock(pPager);

  56028.     assert( pPager->eState==PAGER_OPEN );

  56029.   }else{

  56030.     pPager->eState = PAGER_READER;

  56031.     pPager->hasHeldSharedLock = 1;

  56032.   }

  56033.   return rc;

  56034. }

  56035. 

  56036. /*

  56037. ** If the reference count has reached zero, rollback any active

  56038. ** transaction and unlock the pager.

  56039. **

  56040. ** Except, in locking_mode=EXCLUSIVE when there is nothing to in

  56041. ** the rollback journal, the unlock is not performed and there is

  56042. ** nothing to rollback, so this routine is a no-op.

  56043. */ 

  56044. static void pagerUnlockIfUnused(Pager *pPager){

  56045.   if( sqlite3PcacheRefCount(pPager->pPCache)==0 ){

  56046.     assert( pPager->nMmapOut==0 ); /* because page1 is never memory mapped */

  56047.     pagerUnlockAndRollback(pPager);

  56048.   }

  56049. }

  56050. 

  56051. /*

  56052. ** The page getter methods each try to acquire a reference to a

  56053. ** page with page number pgno. If the requested reference is 

  56054. ** successfully obtained, it is copied to *ppPage and SQLITE_OK returned.

  56055. **

  56056. ** There are different implementations of the getter method depending

  56057. ** on the current state of the pager.

  56058. **

  56059. **     getPageNormal()         --  The normal getter

  56060. **     getPageError()          --  Used if the pager is in an error state

  56061. **     getPageMmap()           --  Used if memory-mapped I/O is enabled

  56062. **

  56063. ** If the requested page is already in the cache, it is returned. 

  56064. ** Otherwise, a new page object is allocated and populated with data

  56065. ** read from the database file. In some cases, the pcache module may

  56066. ** choose not to allocate a new page object and may reuse an existing

  56067. ** object with no outstanding references.

  56068. **

  56069. ** The extra data appended to a page is always initialized to zeros the 

  56070. ** first time a page is loaded into memory. If the page requested is 

  56071. ** already in the cache when this function is called, then the extra

  56072. ** data is left as it was when the page object was last used.

  56073. **

  56074. ** If the database image is smaller than the requested page or if 

  56075. ** the flags parameter contains the PAGER_GET_NOCONTENT bit and the 

  56076. ** requested page is not already stored in the cache, then no 

  56077. ** actual disk read occurs. In this case the memory image of the 

  56078. ** page is initialized to all zeros. 

  56079. **

  56080. ** If PAGER_GET_NOCONTENT is true, it means that we do not care about

  56081. ** the contents of the page. This occurs in two scenarios:

  56082. **

  56083. **   a) When reading a free-list leaf page from the database, and

  56084. **

  56085. **   b) When a savepoint is being rolled back and we need to load

  56086. **      a new page into the cache to be filled with the data read

  56087. **      from the savepoint journal.

  56088. **

  56089. ** If PAGER_GET_NOCONTENT is true, then the data returned is zeroed instead

  56090. ** of being read from the database. Additionally, the bits corresponding

  56091. ** to pgno in Pager.pInJournal (bitvec of pages already written to the

  56092. ** journal file) and the PagerSavepoint.pInSavepoint bitvecs of any open

  56093. ** savepoints are set. This means if the page is made writable at any

  56094. ** point in the future, using a call to sqlite3PagerWrite(), its contents

  56095. ** will not be journaled. This saves IO.

  56096. **

  56097. ** The acquisition might fail for several reasons.  In all cases,

  56098. ** an appropriate error code is returned and *ppPage is set to NULL.

  56099. **

  56100. ** See also sqlite3PagerLookup().  Both this routine and Lookup() attempt

  56101. ** to find a page in the in-memory cache first.  If the page is not already

  56102. ** in memory, this routine goes to disk to read it in whereas Lookup()

  56103. ** just returns 0.  This routine acquires a read-lock the first time it

  56104. ** has to go to disk, and could also playback an old journal if necessary.

  56105. ** Since Lookup() never goes to disk, it never has to deal with locks

  56106. ** or journal files.

  56107. */

  56108. static int getPageNormal(

  56109.   Pager *pPager,      /* The pager open on the database file */

  56110.   Pgno pgno,          /* Page number to fetch */

  56111.   DbPage **ppPage,    /* Write a pointer to the page here */

  56112.   int flags           /* PAGER_GET_XXX flags */

  56113. ){

  56114.   int rc = SQLITE_OK;

  56115.   PgHdr *pPg;

  56116.   u8 noContent;                   /* True if PAGER_GET_NOCONTENT is set */

  56117.   sqlite3_pcache_page *pBase;

  56118. 

  56119.   assert( pPager->errCode==SQLITE_OK );

  56120.   assert( pPager->eState>=PAGER_READER );

  56121.   assert( assert_pager_state(pPager) );

  56122.   assert( pPager->hasHeldSharedLock==1 );

  56123. 

  56124.   if( pgno==0 ) return SQLITE_CORRUPT_BKPT;

  56125.   pBase = sqlite3PcacheFetch(pPager->pPCache, pgno, 3);

  56126.   if( pBase==0 ){

  56127.     pPg = 0;

  56128.     rc = sqlite3PcacheFetchStress(pPager->pPCache, pgno, &pBase);

  56129.     if( rc!=SQLITE_OK ) goto pager_acquire_err;

  56130.     if( pBase==0 ){

  56131.       rc = SQLITE_NOMEM_BKPT;

  56132.       goto pager_acquire_err;

  56133.     }

  56134.   }

  56135.   pPg = *ppPage = sqlite3PcacheFetchFinish(pPager->pPCache, pgno, pBase);

  56136.   assert( pPg==(*ppPage) );

  56137.   assert( pPg->pgno==pgno );

  56138.   assert( pPg->pPager==pPager || pPg->pPager==0 );

  56139. 

  56140.   noContent = (flags & PAGER_GET_NOCONTENT)!=0;

  56141.   if( pPg->pPager && !noContent ){

  56142.     /* In this case the pcache already contains an initialized copy of

  56143.     ** the page. Return without further ado.  */

  56144.     assert( pgno<=PAGER_MAX_PGNO && pgno!=PAGER_MJ_PGNO(pPager) );

  56145.     pPager->aStat[PAGER_STAT_HIT]++;

  56146.     return SQLITE_OK;

  56147. 

  56148.   }else{

  56149.     /* The pager cache has created a new page. Its content needs to 

  56150.     ** be initialized. But first some error checks:

  56151.     **

  56152.     ** (1) The maximum page number is 2^31

  56153.     ** (2) Never try to fetch the locking page

  56154.     */

  56155.     if( pgno>PAGER_MAX_PGNO || pgno==PAGER_MJ_PGNO(pPager) ){

  56156.       rc = SQLITE_CORRUPT_BKPT;

  56157.       goto pager_acquire_err;

  56158.     }

  56159. 

  56160.     pPg->pPager = pPager;

  56161. 

  56162.     assert( !isOpen(pPager->fd) || !MEMDB );

  56163.     if( !isOpen(pPager->fd) || pPager->dbSize<pgno || noContent ){

  56164.       if( pgno>pPager->mxPgno ){

  56165.         rc = SQLITE_FULL;

  56166.         goto pager_acquire_err;

  56167.       }

  56168.       if( noContent ){

  56169.         /* Failure to set the bits in the InJournal bit-vectors is benign.

  56170.         ** It merely means that we might do some extra work to journal a 

  56171.         ** page that does not need to be journaled.  Nevertheless, be sure 

  56172.         ** to test the case where a malloc error occurs while trying to set 

  56173.         ** a bit in a bit vector.

  56174.         */

  56175.         sqlite3BeginBenignMalloc();

  56176.         if( pgno<=pPager->dbOrigSize ){

  56177.           TESTONLY( rc = ) sqlite3BitvecSet(pPager->pInJournal, pgno);

  56178.           testcase( rc==SQLITE_NOMEM );

  56179.         }

  56180.         TESTONLY( rc = ) addToSavepointBitvecs(pPager, pgno);

  56181.         testcase( rc==SQLITE_NOMEM );

  56182.         sqlite3EndBenignMalloc();

  56183.       }

  56184.       memset(pPg->pData, 0, pPager->pageSize);

  56185.       IOTRACE(("ZERO %p %d\n", pPager, pgno));

  56186.     }else{

  56187.       assert( pPg->pPager==pPager );

  56188.       pPager->aStat[PAGER_STAT_MISS]++;

  56189.       rc = readDbPage(pPg);

  56190.       if( rc!=SQLITE_OK ){

  56191.         goto pager_acquire_err;

  56192.       }

  56193.     }

  56194.     pager_set_pagehash(pPg);

  56195.   }

  56196.   return SQLITE_OK;

  56197. 

  56198. pager_acquire_err:

  56199.   assert( rc!=SQLITE_OK );

  56200.   if( pPg ){

  56201.     sqlite3PcacheDrop(pPg);

  56202.   }

  56203.   pagerUnlockIfUnused(pPager);

  56204.   *ppPage = 0;

  56205.   return rc;

  56206. }

  56207. 

  56208. #if SQLITE_MAX_MMAP_SIZE>0

  56209. /* The page getter for when memory-mapped I/O is enabled */

  56210. static int getPageMMap(

  56211.   Pager *pPager,      /* The pager open on the database file */

  56212.   Pgno pgno,          /* Page number to fetch */

  56213.   DbPage **ppPage,    /* Write a pointer to the page here */

  56214.   int flags           /* PAGER_GET_XXX flags */

  56215. ){

  56216.   int rc = SQLITE_OK;

  56217.   PgHdr *pPg = 0;

  56218.   u32 iFrame = 0;                 /* Frame to read from WAL file */

  56219. 

  56220.   /* It is acceptable to use a read-only (mmap) page for any page except

  56221.   ** page 1 if there is no write-transaction open or the ACQUIRE_READONLY

  56222.   ** flag was specified by the caller. And so long as the db is not a 

  56223.   ** temporary or in-memory database.  */

  56224.   const int bMmapOk = (pgno>1

  56225.    && (pPager->eState==PAGER_READER || (flags & PAGER_GET_READONLY))

  56226.   );

  56227. 

  56228.   assert( USEFETCH(pPager) );

  56229. #ifdef SQLITE_HAS_CODEC

  56230.   assert( pPager->xCodec==0 );

  56231. #endif

  56232. 

  56233.   /* Optimization note:  Adding the "pgno<=1" term before "pgno==0" here

  56234.   ** allows the compiler optimizer to reuse the results of the "pgno>1"

  56235.   ** test in the previous statement, and avoid testing pgno==0 in the

  56236.   ** common case where pgno is large. */

  56237.   if( pgno<=1 && pgno==0 ){

  56238.     return SQLITE_CORRUPT_BKPT;

  56239.   }

  56240.   assert( pPager->eState>=PAGER_READER );

  56241.   assert( assert_pager_state(pPager) );

  56242.   assert( pPager->hasHeldSharedLock==1 );

  56243.   assert( pPager->errCode==SQLITE_OK );

  56244. 

  56245.   if( bMmapOk && pagerUseWal(pPager) ){

  56246.     rc = sqlite3WalFindFrame(pPager->pWal, pgno, &iFrame);

  56247.     if( rc!=SQLITE_OK ){

  56248.       *ppPage = 0;

  56249.       return rc;

  56250.     }

  56251.   }

  56252.   if( bMmapOk && iFrame==0 ){

  56253.     void *pData = 0;

  56254.     rc = sqlite3OsFetch(pPager->fd, 

  56255.         (i64)(pgno-1) * pPager->pageSize, pPager->pageSize, &pData

  56256.     );

  56257.     if( rc==SQLITE_OK && pData ){

  56258.       if( pPager->eState>PAGER_READER || pPager->tempFile ){

  56259.         pPg = sqlite3PagerLookup(pPager, pgno);

  56260.       }

  56261.       if( pPg==0 ){

  56262.         rc = pagerAcquireMapPage(pPager, pgno, pData, &pPg);

  56263.       }else{

  56264.         sqlite3OsUnfetch(pPager->fd, (i64)(pgno-1)*pPager->pageSize, pData);

  56265.       }

  56266.       if( pPg ){

  56267.         assert( rc==SQLITE_OK );

  56268.         *ppPage = pPg;

  56269.         return SQLITE_OK;

  56270.       }

  56271.     }

  56272.     if( rc!=SQLITE_OK ){

  56273.       *ppPage = 0;

  56274.       return rc;

  56275.     }

  56276.   }

  56277.   return getPageNormal(pPager, pgno, ppPage, flags);

  56278. }

  56279. #endif /* SQLITE_MAX_MMAP_SIZE>0 */

  56280. 

  56281. /* The page getter method for when the pager is an error state */

  56282. static int getPageError(

  56283.   Pager *pPager,      /* The pager open on the database file */

  56284.   Pgno pgno,          /* Page number to fetch */

  56285.   DbPage **ppPage,    /* Write a pointer to the page here */

  56286.   int flags           /* PAGER_GET_XXX flags */

  56287. ){

  56288.   UNUSED_PARAMETER(pgno);

  56289.   UNUSED_PARAMETER(flags);

  56290.   assert( pPager->errCode!=SQLITE_OK );

  56291.   *ppPage = 0;

  56292.   return pPager->errCode;

  56293. }

  56294. 

  56295. 

  56296. /* Dispatch all page fetch requests to the appropriate getter method.

  56297. */

  56298. SQLITE_PRIVATE int sqlite3PagerGet(

  56299.   Pager *pPager,      /* The pager open on the database file */

  56300.   Pgno pgno,          /* Page number to fetch */

  56301.   DbPage **ppPage,    /* Write a pointer to the page here */

  56302.   int flags           /* PAGER_GET_XXX flags */

  56303. ){

  56304.   return pPager->xGet(pPager, pgno, ppPage, flags);

  56305. }

  56306. 

  56307. /*

  56308. ** Acquire a page if it is already in the in-memory cache.  Do

  56309. ** not read the page from disk.  Return a pointer to the page,

  56310. ** or 0 if the page is not in cache. 

  56311. **

  56312. ** See also sqlite3PagerGet().  The difference between this routine

  56313. ** and sqlite3PagerGet() is that _get() will go to the disk and read

  56314. ** in the page if the page is not already in cache.  This routine

  56315. ** returns NULL if the page is not in cache or if a disk I/O error 

  56316. ** has ever happened.

  56317. */

  56318. SQLITE_PRIVATE DbPage *sqlite3PagerLookup(Pager *pPager, Pgno pgno){

  56319.   sqlite3_pcache_page *pPage;

  56320.   assert( pPager!=0 );

  56321.   assert( pgno!=0 );

  56322.   assert( pPager->pPCache!=0 );

  56323.   pPage = sqlite3PcacheFetch(pPager->pPCache, pgno, 0);

  56324.   assert( pPage==0 || pPager->hasHeldSharedLock );

  56325.   if( pPage==0 ) return 0;

  56326.   return sqlite3PcacheFetchFinish(pPager->pPCache, pgno, pPage);

  56327. }

  56328. 

  56329. /*

  56330. ** Release a page reference.

  56331. **

  56332. ** The sqlite3PagerUnref() and sqlite3PagerUnrefNotNull() may only be

  56333. ** used if we know that the page being released is not the last page.

  56334. ** The btree layer always holds page1 open until the end, so these first

  56335. ** to routines can be used to release any page other than BtShared.pPage1.

  56336. **

  56337. ** Use sqlite3PagerUnrefPageOne() to release page1.  This latter routine

  56338. ** checks the total number of outstanding pages and if the number of

  56339. ** pages reaches zero it drops the database lock.

  56340. */

  56341. SQLITE_PRIVATE void sqlite3PagerUnrefNotNull(DbPage *pPg){

  56342.   TESTONLY( Pager *pPager = pPg->pPager; )

  56343.   assert( pPg!=0 );

  56344.   if( pPg->flags & PGHDR_MMAP ){

  56345.     assert( pPg->pgno!=1 );  /* Page1 is never memory mapped */

  56346.     pagerReleaseMapPage(pPg);

  56347.   }else{

  56348.     sqlite3PcacheRelease(pPg);

  56349.   }

  56350.   /* Do not use this routine to release the last reference to page1 */

  56351.   assert( sqlite3PcacheRefCount(pPager->pPCache)>0 );

  56352. }

  56353. SQLITE_PRIVATE void sqlite3PagerUnref(DbPage *pPg){

  56354.   if( pPg ) sqlite3PagerUnrefNotNull(pPg);

  56355. }

  56356. SQLITE_PRIVATE void sqlite3PagerUnrefPageOne(DbPage *pPg){

  56357.   Pager *pPager;

  56358.   assert( pPg!=0 );

  56359.   assert( pPg->pgno==1 );

  56360.   assert( (pPg->flags & PGHDR_MMAP)==0 ); /* Page1 is never memory mapped */

  56361.   pPager = pPg->pPager;

  56362.   sqlite3PagerResetLockTimeout(pPager);

  56363.   sqlite3PcacheRelease(pPg);

  56364.   pagerUnlockIfUnused(pPager);

  56365. }

  56366. 

  56367. /*

  56368. ** This function is called at the start of every write transaction.

  56369. ** There must already be a RESERVED or EXCLUSIVE lock on the database 

  56370. ** file when this routine is called.

  56371. **

  56372. ** Open the journal file for pager pPager and write a journal header

  56373. ** to the start of it. If there are active savepoints, open the sub-journal

  56374. ** as well. This function is only used when the journal file is being 

  56375. ** opened to write a rollback log for a transaction. It is not used 

  56376. ** when opening a hot journal file to roll it back.

  56377. **

  56378. ** If the journal file is already open (as it may be in exclusive mode),

  56379. ** then this function just writes a journal header to the start of the

  56380. ** already open file. 

  56381. **

  56382. ** Whether or not the journal file is opened by this function, the

  56383. ** Pager.pInJournal bitvec structure is allocated.

  56384. **

  56385. ** Return SQLITE_OK if everything is successful. Otherwise, return 

  56386. ** SQLITE_NOMEM if the attempt to allocate Pager.pInJournal fails, or 

  56387. ** an IO error code if opening or writing the journal file fails.

  56388. */

  56389. static int pager_open_journal(Pager *pPager){

  56390.   int rc = SQLITE_OK;                        /* Return code */

  56391.   sqlite3_vfs * const pVfs = pPager->pVfs;   /* Local cache of vfs pointer */

  56392. 

  56393.   assert( pPager->eState==PAGER_WRITER_LOCKED );

  56394.   assert( assert_pager_state(pPager) );

  56395.   assert( pPager->pInJournal==0 );

  56396.   

  56397.   /* If already in the error state, this function is a no-op.  But on

  56398.   ** the other hand, this routine is never called if we are already in

  56399.   ** an error state. */

  56400.   if( NEVER(pPager->errCode) ) return pPager->errCode;

  56401. 

  56402.   if( !pagerUseWal(pPager) && pPager->journalMode!=PAGER_JOURNALMODE_OFF ){

  56403.     pPager->pInJournal = sqlite3BitvecCreate(pPager->dbSize);

  56404.     if( pPager->pInJournal==0 ){

  56405.       return SQLITE_NOMEM_BKPT;

  56406.     }

  56407.   

  56408.     /* Open the journal file if it is not already open. */

  56409.     if( !isOpen(pPager->jfd) ){

  56410.       if( pPager->journalMode==PAGER_JOURNALMODE_MEMORY ){

  56411.         sqlite3MemJournalOpen(pPager->jfd);

  56412.       }else{

  56413.         int flags = SQLITE_OPEN_READWRITE|SQLITE_OPEN_CREATE;

  56414.         int nSpill;

  56415. 

  56416.         if( pPager->tempFile ){

  56417.           flags |= (SQLITE_OPEN_DELETEONCLOSE|SQLITE_OPEN_TEMP_JOURNAL);

  56418.           nSpill = sqlite3Config.nStmtSpill;

  56419.         }else{

  56420.           flags |= SQLITE_OPEN_MAIN_JOURNAL;

  56421.           nSpill = jrnlBufferSize(pPager);

  56422.         }

  56423.           

  56424.         /* Verify that the database still has the same name as it did when

  56425.         ** it was originally opened. */

  56426.         rc = databaseIsUnmoved(pPager);

  56427.         if( rc==SQLITE_OK ){

  56428.           rc = sqlite3JournalOpen (

  56429.               pVfs, pPager->zJournal, pPager->jfd, flags, nSpill

  56430.           );

  56431.         }

  56432.       }

  56433.       assert( rc!=SQLITE_OK || isOpen(pPager->jfd) );

  56434.     }

  56435.   

  56436.   

  56437.     /* Write the first journal header to the journal file and open 

  56438.     ** the sub-journal if necessary.

  56439.     */

  56440.     if( rc==SQLITE_OK ){

  56441.       /* TODO: Check if all of these are really required. */

  56442.       pPager->nRec = 0;

  56443.       pPager->journalOff = 0;

  56444.       pPager->setMaster = 0;

  56445.       pPager->journalHdr = 0;

  56446.       rc = writeJournalHdr(pPager);

  56447.     }

  56448.   }

  56449. 

  56450.   if( rc!=SQLITE_OK ){

  56451.     sqlite3BitvecDestroy(pPager->pInJournal);

  56452.     pPager->pInJournal = 0;

  56453.   }else{

  56454.     assert( pPager->eState==PAGER_WRITER_LOCKED );

  56455.     pPager->eState = PAGER_WRITER_CACHEMOD;

  56456.   }

  56457. 

  56458.   return rc;

  56459. }

  56460. 

  56461. /*

  56462. ** Begin a write-transaction on the specified pager object. If a 

  56463. ** write-transaction has already been opened, this function is a no-op.

  56464. **

  56465. ** If the exFlag argument is false, then acquire at least a RESERVED

  56466. ** lock on the database file. If exFlag is true, then acquire at least

  56467. ** an EXCLUSIVE lock. If such a lock is already held, no locking 

  56468. ** functions need be called.

  56469. **

  56470. ** If the subjInMemory argument is non-zero, then any sub-journal opened

  56471. ** within this transaction will be opened as an in-memory file. This

  56472. ** has no effect if the sub-journal is already opened (as it may be when

  56473. ** running in exclusive mode) or if the transaction does not require a

  56474. ** sub-journal. If the subjInMemory argument is zero, then any required

  56475. ** sub-journal is implemented in-memory if pPager is an in-memory database, 

  56476. ** or using a temporary file otherwise.

  56477. */

  56478. SQLITE_PRIVATE int sqlite3PagerBegin(Pager *pPager, int exFlag, int subjInMemory){

  56479.   int rc = SQLITE_OK;

  56480. 

  56481.   if( pPager->errCode ) return pPager->errCode;

  56482.   assert( pPager->eState>=PAGER_READER && pPager->eState<PAGER_ERROR );

  56483.   pPager->subjInMemory = (u8)subjInMemory;

  56484. 

  56485.   if( ALWAYS(pPager->eState==PAGER_READER) ){

  56486.     assert( pPager->pInJournal==0 );

  56487. 

  56488.     if( pagerUseWal(pPager) ){

  56489.       /* If the pager is configured to use locking_mode=exclusive, and an

  56490.       ** exclusive lock on the database is not already held, obtain it now.

  56491.       */

  56492.       if( pPager->exclusiveMode && sqlite3WalExclusiveMode(pPager->pWal, -1) ){

  56493.         rc = pagerLockDb(pPager, EXCLUSIVE_LOCK);

  56494.         if( rc!=SQLITE_OK ){

  56495.           return rc;

  56496.         }

  56497.         (void)sqlite3WalExclusiveMode(pPager->pWal, 1);

  56498.       }

  56499. 

  56500.       /* Grab the write lock on the log file. If successful, upgrade to

  56501.       ** PAGER_RESERVED state. Otherwise, return an error code to the caller.

  56502.       ** The busy-handler is not invoked if another connection already

  56503.       ** holds the write-lock. If possible, the upper layer will call it.

  56504.       */

  56505.       rc = sqlite3WalBeginWriteTransaction(pPager->pWal);

  56506.     }else{

  56507.       /* Obtain a RESERVED lock on the database file. If the exFlag parameter

  56508.       ** is true, then immediately upgrade this to an EXCLUSIVE lock. The

  56509.       ** busy-handler callback can be used when upgrading to the EXCLUSIVE

  56510.       ** lock, but not when obtaining the RESERVED lock.

  56511.       */

  56512.       rc = pagerLockDb(pPager, RESERVED_LOCK);

  56513.       if( rc==SQLITE_OK && exFlag ){

  56514.         rc = pager_wait_on_lock(pPager, EXCLUSIVE_LOCK);

  56515.       }

  56516.     }

  56517. 

  56518.     if( rc==SQLITE_OK ){

  56519.       /* Change to WRITER_LOCKED state.

  56520.       **

  56521.       ** WAL mode sets Pager.eState to PAGER_WRITER_LOCKED or CACHEMOD

  56522.       ** when it has an open transaction, but never to DBMOD or FINISHED.

  56523.       ** This is because in those states the code to roll back savepoint 

  56524.       ** transactions may copy data from the sub-journal into the database 

  56525.       ** file as well as into the page cache. Which would be incorrect in 

  56526.       ** WAL mode.

  56527.       */

  56528.       pPager->eState = PAGER_WRITER_LOCKED;

  56529.       pPager->dbHintSize = pPager->dbSize;

  56530.       pPager->dbFileSize = pPager->dbSize;

  56531.       pPager->dbOrigSize = pPager->dbSize;

  56532.       pPager->journalOff = 0;

  56533.     }

  56534. 

  56535.     assert( rc==SQLITE_OK || pPager->eState==PAGER_READER );

  56536.     assert( rc!=SQLITE_OK || pPager->eState==PAGER_WRITER_LOCKED );

  56537.     assert( assert_pager_state(pPager) );

  56538.   }

  56539. 

  56540.   PAGERTRACE(("TRANSACTION %d\n", PAGERID(pPager)));

  56541.   return rc;

  56542. }

  56543. 

  56544. /*

  56545. ** Write page pPg onto the end of the rollback journal.

  56546. */

  56547. static SQLITE_NOINLINE int pagerAddPageToRollbackJournal(PgHdr *pPg){

  56548.   Pager *pPager = pPg->pPager;

  56549.   int rc;

  56550.   u32 cksum;

  56551.   char *pData2;

  56552.   i64 iOff = pPager->journalOff;

  56553. 

  56554.   /* We should never write to the journal file the page that

  56555.   ** contains the database locks.  The following assert verifies

  56556.   ** that we do not. */

  56557.   assert( pPg->pgno!=PAGER_MJ_PGNO(pPager) );

  56558. 

  56559.   assert( pPager->journalHdr<=pPager->journalOff );

  56560.   CODEC2(pPager, pPg->pData, pPg->pgno, 7, return SQLITE_NOMEM_BKPT, pData2);

  56561.   cksum = pager_cksum(pPager, (u8*)pData2);

  56562. 

  56563.   /* Even if an IO or diskfull error occurs while journalling the

  56564.   ** page in the block above, set the need-sync flag for the page.

  56565.   ** Otherwise, when the transaction is rolled back, the logic in

  56566.   ** playback_one_page() will think that the page needs to be restored

  56567.   ** in the database file. And if an IO error occurs while doing so,

  56568.   ** then corruption may follow.

  56569.   */

  56570.   pPg->flags |= PGHDR_NEED_SYNC;

  56571. 

  56572.   rc = write32bits(pPager->jfd, iOff, pPg->pgno);

  56573.   if( rc!=SQLITE_OK ) return rc;

  56574.   rc = sqlite3OsWrite(pPager->jfd, pData2, pPager->pageSize, iOff+4);

  56575.   if( rc!=SQLITE_OK ) return rc;

  56576.   rc = write32bits(pPager->jfd, iOff+pPager->pageSize+4, cksum);

  56577.   if( rc!=SQLITE_OK ) return rc;

  56578. 

  56579.   IOTRACE(("JOUT %p %d %lld %d\n", pPager, pPg->pgno, 

  56580.            pPager->journalOff, pPager->pageSize));

  56581.   PAGER_INCR(sqlite3_pager_writej_count);

  56582.   PAGERTRACE(("JOURNAL %d page %d needSync=%d hash(%08x)\n",

  56583.        PAGERID(pPager), pPg->pgno, 

  56584.        ((pPg->flags&PGHDR_NEED_SYNC)?1:0), pager_pagehash(pPg)));

  56585. 

  56586.   pPager->journalOff += 8 + pPager->pageSize;

  56587.   pPager->nRec++;

  56588.   assert( pPager->pInJournal!=0 );

  56589.   rc = sqlite3BitvecSet(pPager->pInJournal, pPg->pgno);

  56590.   testcase( rc==SQLITE_NOMEM );

  56591.   assert( rc==SQLITE_OK || rc==SQLITE_NOMEM );

  56592.   rc |= addToSavepointBitvecs(pPager, pPg->pgno);

  56593.   assert( rc==SQLITE_OK || rc==SQLITE_NOMEM );

  56594.   return rc;

  56595. }

  56596. 

  56597. /*

  56598. ** Mark a single data page as writeable. The page is written into the 

  56599. ** main journal or sub-journal as required. If the page is written into

  56600. ** one of the journals, the corresponding bit is set in the 

  56601. ** Pager.pInJournal bitvec and the PagerSavepoint.pInSavepoint bitvecs

  56602. ** of any open savepoints as appropriate.

  56603. */

  56604. static int pager_write(PgHdr *pPg){

  56605.   Pager *pPager = pPg->pPager;

  56606.   int rc = SQLITE_OK;

  56607. 

  56608.   /* This routine is not called unless a write-transaction has already 

  56609.   ** been started. The journal file may or may not be open at this point.

  56610.   ** It is never called in the ERROR state.

  56611.   */

  56612.   assert( pPager->eState==PAGER_WRITER_LOCKED

  56613.        || pPager->eState==PAGER_WRITER_CACHEMOD

  56614.        || pPager->eState==PAGER_WRITER_DBMOD

  56615.   );

  56616.   assert( assert_pager_state(pPager) );

  56617.   assert( pPager->errCode==0 );

  56618.   assert( pPager->readOnly==0 );

  56619.   CHECK_PAGE(pPg);

  56620. 

  56621.   /* The journal file needs to be opened. Higher level routines have already

  56622.   ** obtained the necessary locks to begin the write-transaction, but the

  56623.   ** rollback journal might not yet be open. Open it now if this is the case.

  56624.   **

  56625.   ** This is done before calling sqlite3PcacheMakeDirty() on the page. 

  56626.   ** Otherwise, if it were done after calling sqlite3PcacheMakeDirty(), then

  56627.   ** an error might occur and the pager would end up in WRITER_LOCKED state

  56628.   ** with pages marked as dirty in the cache.

  56629.   */

  56630.   if( pPager->eState==PAGER_WRITER_LOCKED ){

  56631.     rc = pager_open_journal(pPager);

  56632.     if( rc!=SQLITE_OK ) return rc;

  56633.   }

  56634.   assert( pPager->eState>=PAGER_WRITER_CACHEMOD );

  56635.   assert( assert_pager_state(pPager) );

  56636. 

  56637.   /* Mark the page that is about to be modified as dirty. */

  56638.   sqlite3PcacheMakeDirty(pPg);

  56639. 

  56640.   /* If a rollback journal is in use, them make sure the page that is about

  56641.   ** to change is in the rollback journal, or if the page is a new page off

  56642.   ** then end of the file, make sure it is marked as PGHDR_NEED_SYNC.

  56643.   */

  56644.   assert( (pPager->pInJournal!=0) == isOpen(pPager->jfd) );

  56645.   if( pPager->pInJournal!=0

  56646.    && sqlite3BitvecTestNotNull(pPager->pInJournal, pPg->pgno)==0

  56647.   ){

  56648.     assert( pagerUseWal(pPager)==0 );

  56649.     if( pPg->pgno<=pPager->dbOrigSize ){

  56650.       rc = pagerAddPageToRollbackJournal(pPg);

  56651.       if( rc!=SQLITE_OK ){

  56652.         return rc;

  56653.       }

  56654.     }else{

  56655.       if( pPager->eState!=PAGER_WRITER_DBMOD ){

  56656.         pPg->flags |= PGHDR_NEED_SYNC;

  56657.       }

  56658.       PAGERTRACE(("APPEND %d page %d needSync=%d\n",

  56659.               PAGERID(pPager), pPg->pgno,

  56660.              ((pPg->flags&PGHDR_NEED_SYNC)?1:0)));

  56661.     }

  56662.   }

  56663. 

  56664.   /* The PGHDR_DIRTY bit is set above when the page was added to the dirty-list

  56665.   ** and before writing the page into the rollback journal.  Wait until now,

  56666.   ** after the page has been successfully journalled, before setting the

  56667.   ** PGHDR_WRITEABLE bit that indicates that the page can be safely modified.

  56668.   */

  56669.   pPg->flags |= PGHDR_WRITEABLE;

  56670.   

  56671.   /* If the statement journal is open and the page is not in it,

  56672.   ** then write the page into the statement journal.

  56673.   */

  56674.   if( pPager->nSavepoint>0 ){

  56675.     rc = subjournalPageIfRequired(pPg);

  56676.   }

  56677. 

  56678.   /* Update the database size and return. */

  56679.   if( pPager->dbSize<pPg->pgno ){

  56680.     pPager->dbSize = pPg->pgno;

  56681.   }

  56682.   return rc;

  56683. }

  56684. 

  56685. /*

  56686. ** This is a variant of sqlite3PagerWrite() that runs when the sector size

  56687. ** is larger than the page size.  SQLite makes the (reasonable) assumption that

  56688. ** all bytes of a sector are written together by hardware.  Hence, all bytes of

  56689. ** a sector need to be journalled in case of a power loss in the middle of

  56690. ** a write.

  56691. **

  56692. ** Usually, the sector size is less than or equal to the page size, in which

  56693. ** case pages can be individually written.  This routine only runs in the

  56694. ** exceptional case where the page size is smaller than the sector size.

  56695. */

  56696. static SQLITE_NOINLINE int pagerWriteLargeSector(PgHdr *pPg){

  56697.   int rc = SQLITE_OK;          /* Return code */

  56698.   Pgno nPageCount;             /* Total number of pages in database file */

  56699.   Pgno pg1;                    /* First page of the sector pPg is located on. */

  56700.   int nPage = 0;               /* Number of pages starting at pg1 to journal */

  56701.   int ii;                      /* Loop counter */

  56702.   int needSync = 0;            /* True if any page has PGHDR_NEED_SYNC */

  56703.   Pager *pPager = pPg->pPager; /* The pager that owns pPg */

  56704.   Pgno nPagePerSector = (pPager->sectorSize/pPager->pageSize);

  56705. 

  56706.   /* Set the doNotSpill NOSYNC bit to 1. This is because we cannot allow

  56707.   ** a journal header to be written between the pages journaled by

  56708.   ** this function.

  56709.   */

  56710.   assert( !MEMDB );

  56711.   assert( (pPager->doNotSpill & SPILLFLAG_NOSYNC)==0 );

  56712.   pPager->doNotSpill |= SPILLFLAG_NOSYNC;

  56713. 

  56714.   /* This trick assumes that both the page-size and sector-size are

  56715.   ** an integer power of 2. It sets variable pg1 to the identifier

  56716.   ** of the first page of the sector pPg is located on.

  56717.   */

  56718.   pg1 = ((pPg->pgno-1) & ~(nPagePerSector-1)) + 1;

  56719. 

  56720.   nPageCount = pPager->dbSize;

  56721.   if( pPg->pgno>nPageCount ){

  56722.     nPage = (pPg->pgno - pg1)+1;

  56723.   }else if( (pg1+nPagePerSector-1)>nPageCount ){

  56724.     nPage = nPageCount+1-pg1;

  56725.   }else{

  56726.     nPage = nPagePerSector;

  56727.   }

  56728.   assert(nPage>0);

  56729.   assert(pg1<=pPg->pgno);

  56730.   assert((pg1+nPage)>pPg->pgno);

  56731. 

  56732.   for(ii=0; ii<nPage && rc==SQLITE_OK; ii++){

  56733.     Pgno pg = pg1+ii;

  56734.     PgHdr *pPage;

  56735.     if( pg==pPg->pgno || !sqlite3BitvecTest(pPager->pInJournal, pg) ){

  56736.       if( pg!=PAGER_MJ_PGNO(pPager) ){

  56737.         rc = sqlite3PagerGet(pPager, pg, &pPage, 0);

  56738.         if( rc==SQLITE_OK ){

  56739.           rc = pager_write(pPage);

  56740.           if( pPage->flags&PGHDR_NEED_SYNC ){

  56741.             needSync = 1;

  56742.           }

  56743.           sqlite3PagerUnrefNotNull(pPage);

  56744.         }

  56745.       }

  56746.     }else if( (pPage = sqlite3PagerLookup(pPager, pg))!=0 ){

  56747.       if( pPage->flags&PGHDR_NEED_SYNC ){

  56748.         needSync = 1;

  56749.       }

  56750.       sqlite3PagerUnrefNotNull(pPage);

  56751.     }

  56752.   }

  56753. 

  56754.   /* If the PGHDR_NEED_SYNC flag is set for any of the nPage pages 

  56755.   ** starting at pg1, then it needs to be set for all of them. Because

  56756.   ** writing to any of these nPage pages may damage the others, the

  56757.   ** journal file must contain sync()ed copies of all of them

  56758.   ** before any of them can be written out to the database file.

  56759.   */

  56760.   if( rc==SQLITE_OK && needSync ){

  56761.     assert( !MEMDB );

  56762.     for(ii=0; ii<nPage; ii++){

  56763.       PgHdr *pPage = sqlite3PagerLookup(pPager, pg1+ii);

  56764.       if( pPage ){

  56765.         pPage->flags |= PGHDR_NEED_SYNC;

  56766.         sqlite3PagerUnrefNotNull(pPage);

  56767.       }

  56768.     }

  56769.   }

  56770. 

  56771.   assert( (pPager->doNotSpill & SPILLFLAG_NOSYNC)!=0 );

  56772.   pPager->doNotSpill &= ~SPILLFLAG_NOSYNC;

  56773.   return rc;

  56774. }

  56775. 

  56776. /*

  56777. ** Mark a data page as writeable. This routine must be called before 

  56778. ** making changes to a page. The caller must check the return value 

  56779. ** of this function and be careful not to change any page data unless 

  56780. ** this routine returns SQLITE_OK.

  56781. **

  56782. ** The difference between this function and pager_write() is that this

  56783. ** function also deals with the special case where 2 or more pages

  56784. ** fit on a single disk sector. In this case all co-resident pages

  56785. ** must have been written to the journal file before returning.

  56786. **

  56787. ** If an error occurs, SQLITE_NOMEM or an IO error code is returned

  56788. ** as appropriate. Otherwise, SQLITE_OK.

  56789. */

  56790. SQLITE_PRIVATE int sqlite3PagerWrite(PgHdr *pPg){

  56791.   Pager *pPager = pPg->pPager;

  56792.   assert( (pPg->flags & PGHDR_MMAP)==0 );

  56793.   assert( pPager->eState>=PAGER_WRITER_LOCKED );

  56794.   assert( assert_pager_state(pPager) );

  56795.   if( (pPg->flags & PGHDR_WRITEABLE)!=0 && pPager->dbSize>=pPg->pgno ){

  56796.     if( pPager->nSavepoint ) return subjournalPageIfRequired(pPg);

  56797.     return SQLITE_OK;

  56798.   }else if( pPager->errCode ){

  56799.     return pPager->errCode;

  56800.   }else if( pPager->sectorSize > (u32)pPager->pageSize ){

  56801.     assert( pPager->tempFile==0 );

  56802.     return pagerWriteLargeSector(pPg);

  56803.   }else{

  56804.     return pager_write(pPg);

  56805.   }

  56806. }

  56807. 

  56808. /*

  56809. ** Return TRUE if the page given in the argument was previously passed

  56810. ** to sqlite3PagerWrite().  In other words, return TRUE if it is ok

  56811. ** to change the content of the page.

  56812. */

  56813. #ifndef NDEBUG

  56814. SQLITE_PRIVATE int sqlite3PagerIswriteable(DbPage *pPg){

  56815.   return pPg->flags & PGHDR_WRITEABLE;

  56816. }

  56817. #endif

  56818. 

  56819. /*

  56820. ** A call to this routine tells the pager that it is not necessary to

  56821. ** write the information on page pPg back to the disk, even though

  56822. ** that page might be marked as dirty.  This happens, for example, when

  56823. ** the page has been added as a leaf of the freelist and so its

  56824. ** content no longer matters.

  56825. **

  56826. ** The overlying software layer calls this routine when all of the data

  56827. ** on the given page is unused. The pager marks the page as clean so

  56828. ** that it does not get written to disk.

  56829. **

  56830. ** Tests show that this optimization can quadruple the speed of large 

  56831. ** DELETE operations.

  56832. **

  56833. ** This optimization cannot be used with a temp-file, as the page may

  56834. ** have been dirty at the start of the transaction. In that case, if

  56835. ** memory pressure forces page pPg out of the cache, the data does need 

  56836. ** to be written out to disk so that it may be read back in if the 

  56837. ** current transaction is rolled back.

  56838. */

  56839. SQLITE_PRIVATE void sqlite3PagerDontWrite(PgHdr *pPg){

  56840.   Pager *pPager = pPg->pPager;

  56841.   if( !pPager->tempFile && (pPg->flags&PGHDR_DIRTY) && pPager->nSavepoint==0 ){

  56842.     PAGERTRACE(("DONT_WRITE page %d of %d\n", pPg->pgno, PAGERID(pPager)));

  56843.     IOTRACE(("CLEAN %p %d\n", pPager, pPg->pgno))

  56844.     pPg->flags |= PGHDR_DONT_WRITE;

  56845.     pPg->flags &= ~PGHDR_WRITEABLE;

  56846.     testcase( pPg->flags & PGHDR_NEED_SYNC );

  56847.     pager_set_pagehash(pPg);

  56848.   }

  56849. }

  56850. 

  56851. /*

  56852. ** This routine is called to increment the value of the database file 

  56853. ** change-counter, stored as a 4-byte big-endian integer starting at 

  56854. ** byte offset 24 of the pager file.  The secondary change counter at

  56855. ** 92 is also updated, as is the SQLite version number at offset 96.

  56856. **

  56857. ** But this only happens if the pPager->changeCountDone flag is false.

  56858. ** To avoid excess churning of page 1, the update only happens once.

  56859. ** See also the pager_write_changecounter() routine that does an 

  56860. ** unconditional update of the change counters.

  56861. **

  56862. ** If the isDirectMode flag is zero, then this is done by calling 

  56863. ** sqlite3PagerWrite() on page 1, then modifying the contents of the

  56864. ** page data. In this case the file will be updated when the current

  56865. ** transaction is committed.

  56866. **

  56867. ** The isDirectMode flag may only be non-zero if the library was compiled

  56868. ** with the SQLITE_ENABLE_ATOMIC_WRITE macro defined. In this case,

  56869. ** if isDirect is non-zero, then the database file is updated directly

  56870. ** by writing an updated version of page 1 using a call to the 

  56871. ** sqlite3OsWrite() function.

  56872. */

  56873. static int pager_incr_changecounter(Pager *pPager, int isDirectMode){

  56874.   int rc = SQLITE_OK;

  56875. 

  56876.   assert( pPager->eState==PAGER_WRITER_CACHEMOD

  56877.        || pPager->eState==PAGER_WRITER_DBMOD

  56878.   );

  56879.   assert( assert_pager_state(pPager) );

  56880. 

  56881.   /* Declare and initialize constant integer 'isDirect'. If the

  56882.   ** atomic-write optimization is enabled in this build, then isDirect

  56883.   ** is initialized to the value passed as the isDirectMode parameter

  56884.   ** to this function. Otherwise, it is always set to zero.

  56885.   **

  56886.   ** The idea is that if the atomic-write optimization is not

  56887.   ** enabled at compile time, the compiler can omit the tests of

  56888.   ** 'isDirect' below, as well as the block enclosed in the

  56889.   ** "if( isDirect )" condition.

  56890.   */

  56891. #ifndef SQLITE_ENABLE_ATOMIC_WRITE

  56892. # define DIRECT_MODE 0

  56893.   assert( isDirectMode==0 );

  56894.   UNUSED_PARAMETER(isDirectMode);

  56895. #else

  56896. # define DIRECT_MODE isDirectMode

  56897. #endif

  56898. 

  56899.   if( !pPager->changeCountDone && ALWAYS(pPager->dbSize>0) ){

  56900.     PgHdr *pPgHdr;                /* Reference to page 1 */

  56901. 

  56902.     assert( !pPager->tempFile && isOpen(pPager->fd) );

  56903. 

  56904.     /* Open page 1 of the file for writing. */

  56905.     rc = sqlite3PagerGet(pPager, 1, &pPgHdr, 0);

  56906.     assert( pPgHdr==0 || rc==SQLITE_OK );

  56907. 

  56908.     /* If page one was fetched successfully, and this function is not

  56909.     ** operating in direct-mode, make page 1 writable.  When not in 

  56910.     ** direct mode, page 1 is always held in cache and hence the PagerGet()

  56911.     ** above is always successful - hence the ALWAYS on rc==SQLITE_OK.

  56912.     */

  56913.     if( !DIRECT_MODE && ALWAYS(rc==SQLITE_OK) ){

  56914.       rc = sqlite3PagerWrite(pPgHdr);

  56915.     }

  56916. 

  56917.     if( rc==SQLITE_OK ){

  56918.       /* Actually do the update of the change counter */

  56919.       pager_write_changecounter(pPgHdr);

  56920. 

  56921.       /* If running in direct mode, write the contents of page 1 to the file. */

  56922.       if( DIRECT_MODE ){

  56923.         const void *zBuf;

  56924.         assert( pPager->dbFileSize>0 );

  56925.         CODEC2(pPager, pPgHdr->pData, 1, 6, rc=SQLITE_NOMEM_BKPT, zBuf);

  56926.         if( rc==SQLITE_OK ){

  56927.           rc = sqlite3OsWrite(pPager->fd, zBuf, pPager->pageSize, 0);

  56928.           pPager->aStat[PAGER_STAT_WRITE]++;

  56929.         }

  56930.         if( rc==SQLITE_OK ){

  56931.           /* Update the pager's copy of the change-counter. Otherwise, the

  56932.           ** next time a read transaction is opened the cache will be

  56933.           ** flushed (as the change-counter values will not match).  */

  56934.           const void *pCopy = (const void *)&((const char *)zBuf)[24];

  56935.           memcpy(&pPager->dbFileVers, pCopy, sizeof(pPager->dbFileVers));

  56936.           pPager->changeCountDone = 1;

  56937.         }

  56938.       }else{

  56939.         pPager->changeCountDone = 1;

  56940.       }

  56941.     }

  56942. 

  56943.     /* Release the page reference. */

  56944.     sqlite3PagerUnref(pPgHdr);

  56945.   }

  56946.   return rc;

  56947. }

  56948. 

  56949. /*

  56950. ** Sync the database file to disk. This is a no-op for in-memory databases

  56951. ** or pages with the Pager.noSync flag set.

  56952. **

  56953. ** If successful, or if called on a pager for which it is a no-op, this

  56954. ** function returns SQLITE_OK. Otherwise, an IO error code is returned.

  56955. */

  56956. SQLITE_PRIVATE int sqlite3PagerSync(Pager *pPager, const char *zMaster){

  56957.   int rc = SQLITE_OK;

  56958.   void *pArg = (void*)zMaster;

  56959.   rc = sqlite3OsFileControl(pPager->fd, SQLITE_FCNTL_SYNC, pArg);

  56960.   if( rc==SQLITE_NOTFOUND ) rc = SQLITE_OK;

  56961.   if( rc==SQLITE_OK && !pPager->noSync ){

  56962.     assert( !MEMDB );

  56963.     rc = sqlite3OsSync(pPager->fd, pPager->syncFlags);

  56964.   }

  56965.   return rc;

  56966. }

  56967. 

  56968. /*

  56969. ** This function may only be called while a write-transaction is active in

  56970. ** rollback. If the connection is in WAL mode, this call is a no-op. 

  56971. ** Otherwise, if the connection does not already have an EXCLUSIVE lock on 

  56972. ** the database file, an attempt is made to obtain one.

  56973. **

  56974. ** If the EXCLUSIVE lock is already held or the attempt to obtain it is

  56975. ** successful, or the connection is in WAL mode, SQLITE_OK is returned.

  56976. ** Otherwise, either SQLITE_BUSY or an SQLITE_IOERR_XXX error code is 

  56977. ** returned.

  56978. */

  56979. SQLITE_PRIVATE int sqlite3PagerExclusiveLock(Pager *pPager){

  56980.   int rc = pPager->errCode;

  56981.   assert( assert_pager_state(pPager) );

  56982.   if( rc==SQLITE_OK ){

  56983.     assert( pPager->eState==PAGER_WRITER_CACHEMOD 

  56984.          || pPager->eState==PAGER_WRITER_DBMOD 

  56985.          || pPager->eState==PAGER_WRITER_LOCKED 

  56986.     );

  56987.     assert( assert_pager_state(pPager) );

  56988.     if( 0==pagerUseWal(pPager) ){

  56989.       rc = pager_wait_on_lock(pPager, EXCLUSIVE_LOCK);

  56990.     }

  56991.   }

  56992.   return rc;

  56993. }

  56994. 

  56995. /*

  56996. ** Sync the database file for the pager pPager. zMaster points to the name

  56997. ** of a master journal file that should be written into the individual

  56998. ** journal file. zMaster may be NULL, which is interpreted as no master

  56999. ** journal (a single database transaction).

  57000. **

  57001. ** This routine ensures that:

  57002. **

  57003. **   * The database file change-counter is updated,

  57004. **   * the journal is synced (unless the atomic-write optimization is used),

  57005. **   * all dirty pages are written to the database file, 

  57006. **   * the database file is truncated (if required), and

  57007. **   * the database file synced. 

  57008. **

  57009. ** The only thing that remains to commit the transaction is to finalize 

  57010. ** (delete, truncate or zero the first part of) the journal file (or 

  57011. ** delete the master journal file if specified).

  57012. **

  57013. ** Note that if zMaster==NULL, this does not overwrite a previous value

  57014. ** passed to an sqlite3PagerCommitPhaseOne() call.

  57015. **

  57016. ** If the final parameter - noSync - is true, then the database file itself

  57017. ** is not synced. The caller must call sqlite3PagerSync() directly to

  57018. ** sync the database file before calling CommitPhaseTwo() to delete the

  57019. ** journal file in this case.

  57020. */

  57021. SQLITE_PRIVATE int sqlite3PagerCommitPhaseOne(

  57022.   Pager *pPager,                  /* Pager object */

  57023.   const char *zMaster,            /* If not NULL, the master journal name */

  57024.   int noSync                      /* True to omit the xSync on the db file */

  57025. ){

  57026.   int rc = SQLITE_OK;             /* Return code */

  57027. 

  57028.   assert( pPager->eState==PAGER_WRITER_LOCKED

  57029.        || pPager->eState==PAGER_WRITER_CACHEMOD

  57030.        || pPager->eState==PAGER_WRITER_DBMOD

  57031.        || pPager->eState==PAGER_ERROR

  57032.   );

  57033.   assert( assert_pager_state(pPager) );

  57034. 

  57035.   /* If a prior error occurred, report that error again. */

  57036.   if( NEVER(pPager->errCode) ) return pPager->errCode;

  57037. 

  57038.   /* Provide the ability to easily simulate an I/O error during testing */

  57039.   if( sqlite3FaultSim(400) ) return SQLITE_IOERR;

  57040. 

  57041.   PAGERTRACE(("DATABASE SYNC: File=%s zMaster=%s nSize=%d\n", 

  57042.       pPager->zFilename, zMaster, pPager->dbSize));

  57043. 

  57044.   /* If no database changes have been made, return early. */

  57045.   if( pPager->eState<PAGER_WRITER_CACHEMOD ) return SQLITE_OK;

  57046. 

  57047.   assert( MEMDB==0 || pPager->tempFile );

  57048.   assert( isOpen(pPager->fd) || pPager->tempFile );

  57049.   if( 0==pagerFlushOnCommit(pPager, 1) ){

  57050.     /* If this is an in-memory db, or no pages have been written to, or this

  57051.     ** function has already been called, it is mostly a no-op.  However, any

  57052.     ** backup in progress needs to be restarted.  */

  57053.     sqlite3BackupRestart(pPager->pBackup);

  57054.   }else{

  57055.     PgHdr *pList;

  57056.     if( pagerUseWal(pPager) ){

  57057.       PgHdr *pPageOne = 0;

  57058.       pList = sqlite3PcacheDirtyList(pPager->pPCache);

  57059.       if( pList==0 ){

  57060.         /* Must have at least one page for the WAL commit flag.

  57061.         ** Ticket [2d1a5c67dfc2363e44f29d9bbd57f] 2011-05-18 */

  57062.         rc = sqlite3PagerGet(pPager, 1, &pPageOne, 0);

  57063.         pList = pPageOne;

  57064.         pList->pDirty = 0;

  57065.       }

  57066.       assert( rc==SQLITE_OK );

  57067.       if( ALWAYS(pList) ){

  57068.         rc = pagerWalFrames(pPager, pList, pPager->dbSize, 1);

  57069.       }

  57070.       sqlite3PagerUnref(pPageOne);

  57071.       if( rc==SQLITE_OK ){

  57072.         sqlite3PcacheCleanAll(pPager->pPCache);

  57073.       }

  57074.     }else{

  57075.       /* The bBatch boolean is true if the batch-atomic-write commit method

  57076.       ** should be used.  No rollback journal is created if batch-atomic-write

  57077.       ** is enabled.

  57078.       */

  57079. #ifdef SQLITE_ENABLE_BATCH_ATOMIC_WRITE

  57080.       sqlite3_file *fd = pPager->fd;

  57081.       int bBatch = zMaster==0    /* An SQLITE_IOCAP_BATCH_ATOMIC commit */

  57082.         && (sqlite3OsDeviceCharacteristics(fd) & SQLITE_IOCAP_BATCH_ATOMIC)

  57083.         && !pPager->noSync

  57084.         && sqlite3JournalIsInMemory(pPager->jfd);

  57085. #else

  57086. #     define bBatch 0

  57087. #endif

  57088. 

  57089. #ifdef SQLITE_ENABLE_ATOMIC_WRITE

  57090.       /* The following block updates the change-counter. Exactly how it

  57091.       ** does this depends on whether or not the atomic-update optimization

  57092.       ** was enabled at compile time, and if this transaction meets the 

  57093.       ** runtime criteria to use the operation: 

  57094.       **

  57095.       **    * The file-system supports the atomic-write property for

  57096.       **      blocks of size page-size, and 

  57097.       **    * This commit is not part of a multi-file transaction, and

  57098.       **    * Exactly one page has been modified and store in the journal file.

  57099.       **

  57100.       ** If the optimization was not enabled at compile time, then the

  57101.       ** pager_incr_changecounter() function is called to update the change

  57102.       ** counter in 'indirect-mode'. If the optimization is compiled in but

  57103.       ** is not applicable to this transaction, call sqlite3JournalCreate()

  57104.       ** to make sure the journal file has actually been created, then call

  57105.       ** pager_incr_changecounter() to update the change-counter in indirect

  57106.       ** mode. 

  57107.       **

  57108.       ** Otherwise, if the optimization is both enabled and applicable,

  57109.       ** then call pager_incr_changecounter() to update the change-counter

  57110.       ** in 'direct' mode. In this case the journal file will never be

  57111.       ** created for this transaction.

  57112.       */

  57113.       if( bBatch==0 ){

  57114.         PgHdr *pPg;

  57115.         assert( isOpen(pPager->jfd) 

  57116.             || pPager->journalMode==PAGER_JOURNALMODE_OFF 

  57117.             || pPager->journalMode==PAGER_JOURNALMODE_WAL 

  57118.             );

  57119.         if( !zMaster && isOpen(pPager->jfd) 

  57120.          && pPager->journalOff==jrnlBufferSize(pPager) 

  57121.          && pPager->dbSize>=pPager->dbOrigSize

  57122.          && (!(pPg = sqlite3PcacheDirtyList(pPager->pPCache)) || 0==pPg->pDirty)

  57123.         ){

  57124.           /* Update the db file change counter via the direct-write method. The 

  57125.           ** following call will modify the in-memory representation of page 1 

  57126.           ** to include the updated change counter and then write page 1 

  57127.           ** directly to the database file. Because of the atomic-write 

  57128.           ** property of the host file-system, this is safe.

  57129.           */

  57130.           rc = pager_incr_changecounter(pPager, 1);

  57131.         }else{

  57132.           rc = sqlite3JournalCreate(pPager->jfd);

  57133.           if( rc==SQLITE_OK ){

  57134.             rc = pager_incr_changecounter(pPager, 0);

  57135.           }

  57136.         }

  57137.       }

  57138. #else  /* SQLITE_ENABLE_ATOMIC_WRITE */

  57139. #ifdef SQLITE_ENABLE_BATCH_ATOMIC_WRITE

  57140.       if( zMaster ){

  57141.         rc = sqlite3JournalCreate(pPager->jfd);

  57142.         if( rc!=SQLITE_OK ) goto commit_phase_one_exit;

  57143.         assert( bBatch==0 );

  57144.       }

  57145. #endif

  57146.       rc = pager_incr_changecounter(pPager, 0);

  57147. #endif /* !SQLITE_ENABLE_ATOMIC_WRITE */

  57148.       if( rc!=SQLITE_OK ) goto commit_phase_one_exit;

  57149.   

  57150.       /* Write the master journal name into the journal file. If a master 

  57151.       ** journal file name has already been written to the journal file, 

  57152.       ** or if zMaster is NULL (no master journal), then this call is a no-op.

  57153.       */

  57154.       rc = writeMasterJournal(pPager, zMaster);

  57155.       if( rc!=SQLITE_OK ) goto commit_phase_one_exit;

  57156.   

  57157.       /* Sync the journal file and write all dirty pages to the database.

  57158.       ** If the atomic-update optimization is being used, this sync will not 

  57159.       ** create the journal file or perform any real IO.

  57160.       **

  57161.       ** Because the change-counter page was just modified, unless the

  57162.       ** atomic-update optimization is used it is almost certain that the

  57163.       ** journal requires a sync here. However, in locking_mode=exclusive

  57164.       ** on a system under memory pressure it is just possible that this is 

  57165.       ** not the case. In this case it is likely enough that the redundant

  57166.       ** xSync() call will be changed to a no-op by the OS anyhow. 

  57167.       */

  57168.       rc = syncJournal(pPager, 0);

  57169.       if( rc!=SQLITE_OK ) goto commit_phase_one_exit;

  57170. 

  57171.       pList = sqlite3PcacheDirtyList(pPager->pPCache);

  57172. #ifdef SQLITE_ENABLE_BATCH_ATOMIC_WRITE

  57173.       if( bBatch ){

  57174.         rc = sqlite3OsFileControl(fd, SQLITE_FCNTL_BEGIN_ATOMIC_WRITE, 0);

  57175.         if( rc==SQLITE_OK ){

  57176.           rc = pager_write_pagelist(pPager, pList);

  57177.           if( rc==SQLITE_OK ){

  57178.             rc = sqlite3OsFileControl(fd, SQLITE_FCNTL_COMMIT_ATOMIC_WRITE, 0);

  57179.           }

  57180.           if( rc!=SQLITE_OK ){

  57181.             sqlite3OsFileControlHint(fd, SQLITE_FCNTL_ROLLBACK_ATOMIC_WRITE, 0);

  57182.           }

  57183.         }

  57184. 

  57185.         if( (rc&0xFF)==SQLITE_IOERR && rc!=SQLITE_IOERR_NOMEM ){

  57186.           rc = sqlite3JournalCreate(pPager->jfd);

  57187.           if( rc!=SQLITE_OK ){

  57188.             sqlite3OsClose(pPager->jfd);

  57189.             goto commit_phase_one_exit;

  57190.           }

  57191.           bBatch = 0;

  57192.         }else{

  57193.           sqlite3OsClose(pPager->jfd);

  57194.         }

  57195.       }

  57196. #endif /* SQLITE_ENABLE_BATCH_ATOMIC_WRITE */

  57197. 

  57198.       if( bBatch==0 ){

  57199.         rc = pager_write_pagelist(pPager, pList);

  57200.       }

  57201.       if( rc!=SQLITE_OK ){

  57202.         assert( rc!=SQLITE_IOERR_BLOCKED );

  57203.         goto commit_phase_one_exit;

  57204.       }

  57205.       sqlite3PcacheCleanAll(pPager->pPCache);

  57206. 

  57207.       /* If the file on disk is smaller than the database image, use 

  57208.       ** pager_truncate to grow the file here. This can happen if the database

  57209.       ** image was extended as part of the current transaction and then the

  57210.       ** last page in the db image moved to the free-list. In this case the

  57211.       ** last page is never written out to disk, leaving the database file

  57212.       ** undersized. Fix this now if it is the case.  */

  57213.       if( pPager->dbSize>pPager->dbFileSize ){

  57214.         Pgno nNew = pPager->dbSize - (pPager->dbSize==PAGER_MJ_PGNO(pPager));

  57215.         assert( pPager->eState==PAGER_WRITER_DBMOD );

  57216.         rc = pager_truncate(pPager, nNew);

  57217.         if( rc!=SQLITE_OK ) goto commit_phase_one_exit;

  57218.       }

  57219.   

  57220.       /* Finally, sync the database file. */

  57221.       if( !noSync ){

  57222.         rc = sqlite3PagerSync(pPager, zMaster);

  57223.       }

  57224.       IOTRACE(("DBSYNC %p\n", pPager))

  57225.     }

  57226.   }

  57227. 

  57228. commit_phase_one_exit:

  57229.   if( rc==SQLITE_OK && !pagerUseWal(pPager) ){

  57230.     pPager->eState = PAGER_WRITER_FINISHED;

  57231.   }

  57232.   return rc;

  57233. }

  57234. 

  57235. 

  57236. /*

  57237. ** When this function is called, the database file has been completely

  57238. ** updated to reflect the changes made by the current transaction and

  57239. ** synced to disk. The journal file still exists in the file-system 

  57240. ** though, and if a failure occurs at this point it will eventually

  57241. ** be used as a hot-journal and the current transaction rolled back.

  57242. **

  57243. ** This function finalizes the journal file, either by deleting, 

  57244. ** truncating or partially zeroing it, so that it cannot be used 

  57245. ** for hot-journal rollback. Once this is done the transaction is

  57246. ** irrevocably committed.

  57247. **

  57248. ** If an error occurs, an IO error code is returned and the pager

  57249. ** moves into the error state. Otherwise, SQLITE_OK is returned.

  57250. */

  57251. SQLITE_PRIVATE int sqlite3PagerCommitPhaseTwo(Pager *pPager){

  57252.   int rc = SQLITE_OK;                  /* Return code */

  57253. 

  57254.   /* This routine should not be called if a prior error has occurred.

  57255.   ** But if (due to a coding error elsewhere in the system) it does get

  57256.   ** called, just return the same error code without doing anything. */

  57257.   if( NEVER(pPager->errCode) ) return pPager->errCode;

  57258. 

  57259.   assert( pPager->eState==PAGER_WRITER_LOCKED

  57260.        || pPager->eState==PAGER_WRITER_FINISHED

  57261.        || (pagerUseWal(pPager) && pPager->eState==PAGER_WRITER_CACHEMOD)

  57262.   );

  57263.   assert( assert_pager_state(pPager) );

  57264. 

  57265.   /* An optimization. If the database was not actually modified during

  57266.   ** this transaction, the pager is running in exclusive-mode and is

  57267.   ** using persistent journals, then this function is a no-op.

  57268.   **

  57269.   ** The start of the journal file currently contains a single journal 

  57270.   ** header with the nRec field set to 0. If such a journal is used as

  57271.   ** a hot-journal during hot-journal rollback, 0 changes will be made

  57272.   ** to the database file. So there is no need to zero the journal 

  57273.   ** header. Since the pager is in exclusive mode, there is no need

  57274.   ** to drop any locks either.

  57275.   */

  57276.   if( pPager->eState==PAGER_WRITER_LOCKED 

  57277.    && pPager->exclusiveMode 

  57278.    && pPager->journalMode==PAGER_JOURNALMODE_PERSIST

  57279.   ){

  57280.     assert( pPager->journalOff==JOURNAL_HDR_SZ(pPager) || !pPager->journalOff );

  57281.     pPager->eState = PAGER_READER;

  57282.     return SQLITE_OK;

  57283.   }

  57284. 

  57285.   PAGERTRACE(("COMMIT %d\n", PAGERID(pPager)));

  57286.   pPager->iDataVersion++;

  57287.   rc = pager_end_transaction(pPager, pPager->setMaster, 1);

  57288.   return pager_error(pPager, rc);

  57289. }

  57290. 

  57291. /*

  57292. ** If a write transaction is open, then all changes made within the 

  57293. ** transaction are reverted and the current write-transaction is closed.

  57294. ** The pager falls back to PAGER_READER state if successful, or PAGER_ERROR

  57295. ** state if an error occurs.

  57296. **

  57297. ** If the pager is already in PAGER_ERROR state when this function is called,

  57298. ** it returns Pager.errCode immediately. No work is performed in this case.

  57299. **

  57300. ** Otherwise, in rollback mode, this function performs two functions:

  57301. **

  57302. **   1) It rolls back the journal file, restoring all database file and 

  57303. **      in-memory cache pages to the state they were in when the transaction

  57304. **      was opened, and

  57305. **

  57306. **   2) It finalizes the journal file, so that it is not used for hot

  57307. **      rollback at any point in the future.

  57308. **

  57309. ** Finalization of the journal file (task 2) is only performed if the 

  57310. ** rollback is successful.

  57311. **

  57312. ** In WAL mode, all cache-entries containing data modified within the

  57313. ** current transaction are either expelled from the cache or reverted to

  57314. ** their pre-transaction state by re-reading data from the database or

  57315. ** WAL files. The WAL transaction is then closed.

  57316. */

  57317. SQLITE_PRIVATE int sqlite3PagerRollback(Pager *pPager){

  57318.   int rc = SQLITE_OK;                  /* Return code */

  57319.   PAGERTRACE(("ROLLBACK %d\n", PAGERID(pPager)));

  57320. 

  57321.   /* PagerRollback() is a no-op if called in READER or OPEN state. If

  57322.   ** the pager is already in the ERROR state, the rollback is not 

  57323.   ** attempted here. Instead, the error code is returned to the caller.

  57324.   */

  57325.   assert( assert_pager_state(pPager) );

  57326.   if( pPager->eState==PAGER_ERROR ) return pPager->errCode;

  57327.   if( pPager->eState<=PAGER_READER ) return SQLITE_OK;

  57328. 

  57329.   if( pagerUseWal(pPager) ){

  57330.     int rc2;

  57331.     rc = sqlite3PagerSavepoint(pPager, SAVEPOINT_ROLLBACK, -1);

  57332.     rc2 = pager_end_transaction(pPager, pPager->setMaster, 0);

  57333.     if( rc==SQLITE_OK ) rc = rc2;

  57334.   }else if( !isOpen(pPager->jfd) || pPager->eState==PAGER_WRITER_LOCKED ){

  57335.     int eState = pPager->eState;

  57336.     rc = pager_end_transaction(pPager, 0, 0);

  57337.     if( !MEMDB && eState>PAGER_WRITER_LOCKED ){

  57338.       /* This can happen using journal_mode=off. Move the pager to the error 

  57339.       ** state to indicate that the contents of the cache may not be trusted.

  57340.       ** Any active readers will get SQLITE_ABORT.

  57341.       */

  57342.       pPager->errCode = SQLITE_ABORT;

  57343.       pPager->eState = PAGER_ERROR;

  57344.       setGetterMethod(pPager);

  57345.       return rc;

  57346.     }

  57347.   }else{

  57348.     rc = pager_playback(pPager, 0);

  57349.   }

  57350. 

  57351.   assert( pPager->eState==PAGER_READER || rc!=SQLITE_OK );

  57352.   assert( rc==SQLITE_OK || rc==SQLITE_FULL || rc==SQLITE_CORRUPT

  57353.           || rc==SQLITE_NOMEM || (rc&0xFF)==SQLITE_IOERR 

  57354.           || rc==SQLITE_CANTOPEN

  57355.   );

  57356. 

  57357.   /* If an error occurs during a ROLLBACK, we can no longer trust the pager

  57358.   ** cache. So call pager_error() on the way out to make any error persistent.

  57359.   */

  57360.   return pager_error(pPager, rc);

  57361. }

  57362. 

  57363. /*

  57364. ** Return TRUE if the database file is opened read-only.  Return FALSE

  57365. ** if the database is (in theory) writable.

  57366. */

  57367. SQLITE_PRIVATE u8 sqlite3PagerIsreadonly(Pager *pPager){

  57368.   return pPager->readOnly;

  57369. }

  57370. 

  57371. #ifdef SQLITE_DEBUG

  57372. /*

  57373. ** Return the sum of the reference counts for all pages held by pPager.

  57374. */

  57375. SQLITE_PRIVATE int sqlite3PagerRefcount(Pager *pPager){

  57376.   return sqlite3PcacheRefCount(pPager->pPCache);

  57377. }

  57378. #endif

  57379. 

  57380. /*

  57381. ** Return the approximate number of bytes of memory currently

  57382. ** used by the pager and its associated cache.

  57383. */

  57384. SQLITE_PRIVATE int sqlite3PagerMemUsed(Pager *pPager){

  57385.   int perPageSize = pPager->pageSize + pPager->nExtra + sizeof(PgHdr)

  57386.                                      + 5*sizeof(void*);

  57387.   return perPageSize*sqlite3PcachePagecount(pPager->pPCache)

  57388.            + sqlite3MallocSize(pPager)

  57389.            + pPager->pageSize;

  57390. }

  57391. 

  57392. /*

  57393. ** Return the number of references to the specified page.

  57394. */

  57395. SQLITE_PRIVATE int sqlite3PagerPageRefcount(DbPage *pPage){

  57396.   return sqlite3PcachePageRefcount(pPage);

  57397. }

  57398. 

  57399. #ifdef SQLITE_TEST

  57400. /*

  57401. ** This routine is used for testing and analysis only.

  57402. */

  57403. SQLITE_PRIVATE int *sqlite3PagerStats(Pager *pPager){

  57404.   static int a[11];

  57405.   a[0] = sqlite3PcacheRefCount(pPager->pPCache);

  57406.   a[1] = sqlite3PcachePagecount(pPager->pPCache);

  57407.   a[2] = sqlite3PcacheGetCachesize(pPager->pPCache);

  57408.   a[3] = pPager->eState==PAGER_OPEN ? -1 : (int) pPager->dbSize;

  57409.   a[4] = pPager->eState;

  57410.   a[5] = pPager->errCode;

  57411.   a[6] = pPager->aStat[PAGER_STAT_HIT];

  57412.   a[7] = pPager->aStat[PAGER_STAT_MISS];

  57413.   a[8] = 0;  /* Used to be pPager->nOvfl */

  57414.   a[9] = pPager->nRead;

  57415.   a[10] = pPager->aStat[PAGER_STAT_WRITE];

  57416.   return a;

  57417. }

  57418. #endif

  57419. 

  57420. /*

  57421. ** Parameter eStat must be one of SQLITE_DBSTATUS_CACHE_HIT, _MISS, _WRITE,

  57422. ** or _WRITE+1.  The SQLITE_DBSTATUS_CACHE_WRITE+1 case is a translation

  57423. ** of SQLITE_DBSTATUS_CACHE_SPILL.  The _SPILL case is not contiguous because

  57424. ** it was added later.

  57425. **

  57426. ** Before returning, *pnVal is incremented by the

  57427. ** current cache hit or miss count, according to the value of eStat. If the 

  57428. ** reset parameter is non-zero, the cache hit or miss count is zeroed before 

  57429. ** returning.

  57430. */

  57431. SQLITE_PRIVATE void sqlite3PagerCacheStat(Pager *pPager, int eStat, int reset, int *pnVal){

  57432. 

  57433.   assert( eStat==SQLITE_DBSTATUS_CACHE_HIT

  57434.        || eStat==SQLITE_DBSTATUS_CACHE_MISS

  57435.        || eStat==SQLITE_DBSTATUS_CACHE_WRITE

  57436.        || eStat==SQLITE_DBSTATUS_CACHE_WRITE+1

  57437.   );

  57438. 

  57439.   assert( SQLITE_DBSTATUS_CACHE_HIT+1==SQLITE_DBSTATUS_CACHE_MISS );

  57440.   assert( SQLITE_DBSTATUS_CACHE_HIT+2==SQLITE_DBSTATUS_CACHE_WRITE );

  57441.   assert( PAGER_STAT_HIT==0 && PAGER_STAT_MISS==1

  57442.            && PAGER_STAT_WRITE==2 && PAGER_STAT_SPILL==3 );

  57443. 

  57444.   eStat -= SQLITE_DBSTATUS_CACHE_HIT;

  57445.   *pnVal += pPager->aStat[eStat];

  57446.   if( reset ){

  57447.     pPager->aStat[eStat] = 0;

  57448.   }

  57449. }

  57450. 

  57451. /*

  57452. ** Return true if this is an in-memory or temp-file backed pager.

  57453. */

  57454. SQLITE_PRIVATE int sqlite3PagerIsMemdb(Pager *pPager){

  57455.   return pPager->tempFile;

  57456. }

  57457. 

  57458. /*

  57459. ** Check that there are at least nSavepoint savepoints open. If there are

  57460. ** currently less than nSavepoints open, then open one or more savepoints

  57461. ** to make up the difference. If the number of savepoints is already

  57462. ** equal to nSavepoint, then this function is a no-op.

  57463. **

  57464. ** If a memory allocation fails, SQLITE_NOMEM is returned. If an error 

  57465. ** occurs while opening the sub-journal file, then an IO error code is

  57466. ** returned. Otherwise, SQLITE_OK.

  57467. */

  57468. static SQLITE_NOINLINE int pagerOpenSavepoint(Pager *pPager, int nSavepoint){

  57469.   int rc = SQLITE_OK;                       /* Return code */

  57470.   int nCurrent = pPager->nSavepoint;        /* Current number of savepoints */

  57471.   int ii;                                   /* Iterator variable */

  57472.   PagerSavepoint *aNew;                     /* New Pager.aSavepoint array */

  57473. 

  57474.   assert( pPager->eState>=PAGER_WRITER_LOCKED );

  57475.   assert( assert_pager_state(pPager) );

  57476.   assert( nSavepoint>nCurrent && pPager->useJournal );

  57477. 

  57478.   /* Grow the Pager.aSavepoint array using realloc(). Return SQLITE_NOMEM

  57479.   ** if the allocation fails. Otherwise, zero the new portion in case a 

  57480.   ** malloc failure occurs while populating it in the for(...) loop below.

  57481.   */

  57482.   aNew = (PagerSavepoint *)sqlite3Realloc(

  57483.       pPager->aSavepoint, sizeof(PagerSavepoint)*nSavepoint

  57484.   );

  57485.   if( !aNew ){

  57486.     return SQLITE_NOMEM_BKPT;

  57487.   }

  57488.   memset(&aNew[nCurrent], 0, (nSavepoint-nCurrent) * sizeof(PagerSavepoint));

  57489.   pPager->aSavepoint = aNew;

  57490. 

  57491.   /* Populate the PagerSavepoint structures just allocated. */

  57492.   for(ii=nCurrent; ii<nSavepoint; ii++){

  57493.     aNew[ii].nOrig = pPager->dbSize;

  57494.     if( isOpen(pPager->jfd) && pPager->journalOff>0 ){

  57495.       aNew[ii].iOffset = pPager->journalOff;

  57496.     }else{

  57497.       aNew[ii].iOffset = JOURNAL_HDR_SZ(pPager);

  57498.     }

  57499.     aNew[ii].iSubRec = pPager->nSubRec;

  57500.     aNew[ii].pInSavepoint = sqlite3BitvecCreate(pPager->dbSize);

  57501.     if( !aNew[ii].pInSavepoint ){

  57502.       return SQLITE_NOMEM_BKPT;

  57503.     }

  57504.     if( pagerUseWal(pPager) ){

  57505.       sqlite3WalSavepoint(pPager->pWal, aNew[ii].aWalData);

  57506.     }

  57507.     pPager->nSavepoint = ii+1;

  57508.   }

  57509.   assert( pPager->nSavepoint==nSavepoint );

  57510.   assertTruncateConstraint(pPager);

  57511.   return rc;

  57512. }

  57513. SQLITE_PRIVATE int sqlite3PagerOpenSavepoint(Pager *pPager, int nSavepoint){

  57514.   assert( pPager->eState>=PAGER_WRITER_LOCKED );

  57515.   assert( assert_pager_state(pPager) );

  57516. 

  57517.   if( nSavepoint>pPager->nSavepoint && pPager->useJournal ){

  57518.     return pagerOpenSavepoint(pPager, nSavepoint);

  57519.   }else{

  57520.     return SQLITE_OK;

  57521.   }

  57522. }

  57523. 

  57524. 

  57525. /*

  57526. ** This function is called to rollback or release (commit) a savepoint.

  57527. ** The savepoint to release or rollback need not be the most recently 

  57528. ** created savepoint.

  57529. **

  57530. ** Parameter op is always either SAVEPOINT_ROLLBACK or SAVEPOINT_RELEASE.

  57531. ** If it is SAVEPOINT_RELEASE, then release and destroy the savepoint with

  57532. ** index iSavepoint. If it is SAVEPOINT_ROLLBACK, then rollback all changes

  57533. ** that have occurred since the specified savepoint was created.

  57534. **

  57535. ** The savepoint to rollback or release is identified by parameter 

  57536. ** iSavepoint. A value of 0 means to operate on the outermost savepoint

  57537. ** (the first created). A value of (Pager.nSavepoint-1) means operate

  57538. ** on the most recently created savepoint. If iSavepoint is greater than

  57539. ** (Pager.nSavepoint-1), then this function is a no-op.

  57540. **

  57541. ** If a negative value is passed to this function, then the current

  57542. ** transaction is rolled back. This is different to calling 

  57543. ** sqlite3PagerRollback() because this function does not terminate

  57544. ** the transaction or unlock the database, it just restores the 

  57545. ** contents of the database to its original state. 

  57546. **

  57547. ** In any case, all savepoints with an index greater than iSavepoint 

  57548. ** are destroyed. If this is a release operation (op==SAVEPOINT_RELEASE),

  57549. ** then savepoint iSavepoint is also destroyed.

  57550. **

  57551. ** This function may return SQLITE_NOMEM if a memory allocation fails,

  57552. ** or an IO error code if an IO error occurs while rolling back a 

  57553. ** savepoint. If no errors occur, SQLITE_OK is returned.

  57554. */ 

  57555. SQLITE_PRIVATE int sqlite3PagerSavepoint(Pager *pPager, int op, int iSavepoint){

  57556.   int rc = pPager->errCode;

  57557.   

  57558. #ifdef SQLITE_ENABLE_ZIPVFS

  57559.   if( op==SAVEPOINT_RELEASE ) rc = SQLITE_OK;

  57560. #endif

  57561. 

  57562.   assert( op==SAVEPOINT_RELEASE || op==SAVEPOINT_ROLLBACK );

  57563.   assert( iSavepoint>=0 || op==SAVEPOINT_ROLLBACK );

  57564. 

  57565.   if( rc==SQLITE_OK && iSavepoint<pPager->nSavepoint ){

  57566.     int ii;            /* Iterator variable */

  57567.     int nNew;          /* Number of remaining savepoints after this op. */

  57568. 

  57569.     /* Figure out how many savepoints will still be active after this

  57570.     ** operation. Store this value in nNew. Then free resources associated 

  57571.     ** with any savepoints that are destroyed by this operation.

  57572.     */

  57573.     nNew = iSavepoint + (( op==SAVEPOINT_RELEASE ) ? 0 : 1);

  57574.     for(ii=nNew; ii<pPager->nSavepoint; ii++){

  57575.       sqlite3BitvecDestroy(pPager->aSavepoint[ii].pInSavepoint);

  57576.     }

  57577.     pPager->nSavepoint = nNew;

  57578. 

  57579.     /* If this is a release of the outermost savepoint, truncate 

  57580.     ** the sub-journal to zero bytes in size. */

  57581.     if( op==SAVEPOINT_RELEASE ){

  57582.       if( nNew==0 && isOpen(pPager->sjfd) ){

  57583.         /* Only truncate if it is an in-memory sub-journal. */

  57584.         if( sqlite3JournalIsInMemory(pPager->sjfd) ){

  57585.           rc = sqlite3OsTruncate(pPager->sjfd, 0);

  57586.           assert( rc==SQLITE_OK );

  57587.         }

  57588.         pPager->nSubRec = 0;

  57589.       }

  57590.     }

  57591.     /* Else this is a rollback operation, playback the specified savepoint.

  57592.     ** If this is a temp-file, it is possible that the journal file has

  57593.     ** not yet been opened. In this case there have been no changes to

  57594.     ** the database file, so the playback operation can be skipped.

  57595.     */

  57596.     else if( pagerUseWal(pPager) || isOpen(pPager->jfd) ){

  57597.       PagerSavepoint *pSavepoint = (nNew==0)?0:&pPager->aSavepoint[nNew-1];

  57598.       rc = pagerPlaybackSavepoint(pPager, pSavepoint);

  57599.       assert(rc!=SQLITE_DONE);

  57600.     }

  57601.     

  57602. #ifdef SQLITE_ENABLE_ZIPVFS

  57603.     /* If the cache has been modified but the savepoint cannot be rolled 

  57604.     ** back journal_mode=off, put the pager in the error state. This way,

  57605.     ** if the VFS used by this pager includes ZipVFS, the entire transaction

  57606.     ** can be rolled back at the ZipVFS level.  */

  57607.     else if( 

  57608.         pPager->journalMode==PAGER_JOURNALMODE_OFF 

  57609.      && pPager->eState>=PAGER_WRITER_CACHEMOD

  57610.     ){

  57611.       pPager->errCode = SQLITE_ABORT;

  57612.       pPager->eState = PAGER_ERROR;

  57613.       setGetterMethod(pPager);

  57614.     }

  57615. #endif

  57616.   }

  57617. 

  57618.   return rc;

  57619. }

  57620. 

  57621. /*

  57622. ** Return the full pathname of the database file.

  57623. **

  57624. ** Except, if the pager is in-memory only, then return an empty string if

  57625. ** nullIfMemDb is true.  This routine is called with nullIfMemDb==1 when

  57626. ** used to report the filename to the user, for compatibility with legacy

  57627. ** behavior.  But when the Btree needs to know the filename for matching to

  57628. ** shared cache, it uses nullIfMemDb==0 so that in-memory databases can

  57629. ** participate in shared-cache.

  57630. */

  57631. SQLITE_PRIVATE const char *sqlite3PagerFilename(Pager *pPager, int nullIfMemDb){

  57632.   return (nullIfMemDb && pPager->memDb) ? "" : pPager->zFilename;

  57633. }

  57634. 

  57635. /*

  57636. ** Return the VFS structure for the pager.

  57637. */

  57638. SQLITE_PRIVATE sqlite3_vfs *sqlite3PagerVfs(Pager *pPager){

  57639.   return pPager->pVfs;

  57640. }

  57641. 

  57642. /*

  57643. ** Return the file handle for the database file associated

  57644. ** with the pager.  This might return NULL if the file has

  57645. ** not yet been opened.

  57646. */

  57647. SQLITE_PRIVATE sqlite3_file *sqlite3PagerFile(Pager *pPager){

  57648.   return pPager->fd;

  57649. }

  57650. 

  57651. #ifdef SQLITE_ENABLE_SETLK_TIMEOUT

  57652. /*

  57653. ** Reset the lock timeout for pager.

  57654. */

  57655. SQLITE_PRIVATE void sqlite3PagerResetLockTimeout(Pager *pPager){

  57656.   int x = 0;

  57657.   sqlite3OsFileControl(pPager->fd, SQLITE_FCNTL_LOCK_TIMEOUT, &x);

  57658. }

  57659. #endif

  57660. 

  57661. /*

  57662. ** Return the file handle for the journal file (if it exists).

  57663. ** This will be either the rollback journal or the WAL file.

  57664. */

  57665. SQLITE_PRIVATE sqlite3_file *sqlite3PagerJrnlFile(Pager *pPager){

  57666. #if SQLITE_OMIT_WAL

  57667.   return pPager->jfd;

  57668. #else

  57669.   return pPager->pWal ? sqlite3WalFile(pPager->pWal) : pPager->jfd;

  57670. #endif

  57671. }

  57672. 

  57673. /*

  57674. ** Return the full pathname of the journal file.

  57675. */

  57676. SQLITE_PRIVATE const char *sqlite3PagerJournalname(Pager *pPager){

  57677.   return pPager->zJournal;

  57678. }

  57679. 

  57680. #ifdef SQLITE_HAS_CODEC

  57681. /*

  57682. ** Set or retrieve the codec for this pager

  57683. */

  57684. SQLITE_PRIVATE void sqlite3PagerSetCodec(

  57685.   Pager *pPager,

  57686.   void *(*xCodec)(void*,void*,Pgno,int),

  57687.   void (*xCodecSizeChng)(void*,int,int),

  57688.   void (*xCodecFree)(void*),

  57689.   void *pCodec

  57690. ){

  57691.   if( pPager->xCodecFree ){

  57692.     pPager->xCodecFree(pPager->pCodec);

  57693.   }else{

  57694.     pager_reset(pPager);

  57695.   }

  57696.   pPager->xCodec = pPager->memDb ? 0 : xCodec;

  57697.   pPager->xCodecSizeChng = xCodecSizeChng;

  57698.   pPager->xCodecFree = xCodecFree;

  57699.   pPager->pCodec = pCodec;

  57700.   setGetterMethod(pPager);

  57701.   pagerReportSize(pPager);

  57702. }

  57703. SQLITE_PRIVATE void *sqlite3PagerGetCodec(Pager *pPager){

  57704.   return pPager->pCodec;

  57705. }

  57706. 

  57707. /*

  57708. ** This function is called by the wal module when writing page content

  57709. ** into the log file.

  57710. **

  57711. ** This function returns a pointer to a buffer containing the encrypted

  57712. ** page content. If a malloc fails, this function may return NULL.

  57713. */

  57714. SQLITE_PRIVATE void *sqlite3PagerCodec(PgHdr *pPg){

  57715.   void *aData = 0;

  57716.   CODEC2(pPg->pPager, pPg->pData, pPg->pgno, 6, return 0, aData);

  57717.   return aData;

  57718. }

  57719. 

  57720. /*

  57721. ** Return the current pager state

  57722. */

  57723. SQLITE_PRIVATE int sqlite3PagerState(Pager *pPager){

  57724.   return pPager->eState;

  57725. }

  57726. #endif /* SQLITE_HAS_CODEC */

  57727. 

  57728. #ifndef SQLITE_OMIT_AUTOVACUUM

  57729. /*

  57730. ** Move the page pPg to location pgno in the file.

  57731. **

  57732. ** There must be no references to the page previously located at

  57733. ** pgno (which we call pPgOld) though that page is allowed to be

  57734. ** in cache.  If the page previously located at pgno is not already

  57735. ** in the rollback journal, it is not put there by by this routine.

  57736. **

  57737. ** References to the page pPg remain valid. Updating any

  57738. ** meta-data associated with pPg (i.e. data stored in the nExtra bytes

  57739. ** allocated along with the page) is the responsibility of the caller.

  57740. **

  57741. ** A transaction must be active when this routine is called. It used to be

  57742. ** required that a statement transaction was not active, but this restriction

  57743. ** has been removed (CREATE INDEX needs to move a page when a statement

  57744. ** transaction is active).

  57745. **

  57746. ** If the fourth argument, isCommit, is non-zero, then this page is being

  57747. ** moved as part of a database reorganization just before the transaction 

  57748. ** is being committed. In this case, it is guaranteed that the database page 

  57749. ** pPg refers to will not be written to again within this transaction.

  57750. **

  57751. ** This function may return SQLITE_NOMEM or an IO error code if an error

  57752. ** occurs. Otherwise, it returns SQLITE_OK.

  57753. */

  57754. SQLITE_PRIVATE int sqlite3PagerMovepage(Pager *pPager, DbPage *pPg, Pgno pgno, int isCommit){

  57755.   PgHdr *pPgOld;               /* The page being overwritten. */

  57756.   Pgno needSyncPgno = 0;       /* Old value of pPg->pgno, if sync is required */

  57757.   int rc;                      /* Return code */

  57758.   Pgno origPgno;               /* The original page number */

  57759. 

  57760.   assert( pPg->nRef>0 );

  57761.   assert( pPager->eState==PAGER_WRITER_CACHEMOD

  57762.        || pPager->eState==PAGER_WRITER_DBMOD

  57763.   );

  57764.   assert( assert_pager_state(pPager) );

  57765. 

  57766.   /* In order to be able to rollback, an in-memory database must journal

  57767.   ** the page we are moving from.

  57768.   */

  57769.   assert( pPager->tempFile || !MEMDB );

  57770.   if( pPager->tempFile ){

  57771.     rc = sqlite3PagerWrite(pPg);

  57772.     if( rc ) return rc;

  57773.   }

  57774. 

  57775.   /* If the page being moved is dirty and has not been saved by the latest

  57776.   ** savepoint, then save the current contents of the page into the 

  57777.   ** sub-journal now. This is required to handle the following scenario:

  57778.   **

  57779.   **   BEGIN;

  57780.   **     <journal page X, then modify it in memory>

  57781.   **     SAVEPOINT one;

  57782.   **       <Move page X to location Y>

  57783.   **     ROLLBACK TO one;

  57784.   **

  57785.   ** If page X were not written to the sub-journal here, it would not

  57786.   ** be possible to restore its contents when the "ROLLBACK TO one"

  57787.   ** statement were is processed.

  57788.   **

  57789.   ** subjournalPage() may need to allocate space to store pPg->pgno into

  57790.   ** one or more savepoint bitvecs. This is the reason this function

  57791.   ** may return SQLITE_NOMEM.

  57792.   */

  57793.   if( (pPg->flags & PGHDR_DIRTY)!=0

  57794.    && SQLITE_OK!=(rc = subjournalPageIfRequired(pPg))

  57795.   ){

  57796.     return rc;

  57797.   }

  57798. 

  57799.   PAGERTRACE(("MOVE %d page %d (needSync=%d) moves to %d\n", 

  57800.       PAGERID(pPager), pPg->pgno, (pPg->flags&PGHDR_NEED_SYNC)?1:0, pgno));

  57801.   IOTRACE(("MOVE %p %d %d\n", pPager, pPg->pgno, pgno))

  57802. 

  57803.   /* If the journal needs to be sync()ed before page pPg->pgno can

  57804.   ** be written to, store pPg->pgno in local variable needSyncPgno.

  57805.   **

  57806.   ** If the isCommit flag is set, there is no need to remember that

  57807.   ** the journal needs to be sync()ed before database page pPg->pgno 

  57808.   ** can be written to. The caller has already promised not to write to it.

  57809.   */

  57810.   if( (pPg->flags&PGHDR_NEED_SYNC) && !isCommit ){

  57811.     needSyncPgno = pPg->pgno;

  57812.     assert( pPager->journalMode==PAGER_JOURNALMODE_OFF ||

  57813.             pageInJournal(pPager, pPg) || pPg->pgno>pPager->dbOrigSize );

  57814.     assert( pPg->flags&PGHDR_DIRTY );

  57815.   }

  57816. 

  57817.   /* If the cache contains a page with page-number pgno, remove it

  57818.   ** from its hash chain. Also, if the PGHDR_NEED_SYNC flag was set for 

  57819.   ** page pgno before the 'move' operation, it needs to be retained 

  57820.   ** for the page moved there.

  57821.   */

  57822.   pPg->flags &= ~PGHDR_NEED_SYNC;

  57823.   pPgOld = sqlite3PagerLookup(pPager, pgno);

  57824.   assert( !pPgOld || pPgOld->nRef==1 || CORRUPT_DB );

  57825.   if( pPgOld ){

  57826.     if( pPgOld->nRef>1 ){

  57827.       sqlite3PagerUnrefNotNull(pPgOld);

  57828.       return SQLITE_CORRUPT_BKPT;

  57829.     }

  57830.     pPg->flags |= (pPgOld->flags&PGHDR_NEED_SYNC);

  57831.     if( pPager->tempFile ){

  57832.       /* Do not discard pages from an in-memory database since we might

  57833.       ** need to rollback later.  Just move the page out of the way. */

  57834.       sqlite3PcacheMove(pPgOld, pPager->dbSize+1);

  57835.     }else{

  57836.       sqlite3PcacheDrop(pPgOld);

  57837.     }

  57838.   }

  57839. 

  57840.   origPgno = pPg->pgno;

  57841.   sqlite3PcacheMove(pPg, pgno);

  57842.   sqlite3PcacheMakeDirty(pPg);

  57843. 

  57844.   /* For an in-memory database, make sure the original page continues

  57845.   ** to exist, in case the transaction needs to roll back.  Use pPgOld

  57846.   ** as the original page since it has already been allocated.

  57847.   */

  57848.   if( pPager->tempFile && pPgOld ){

  57849.     sqlite3PcacheMove(pPgOld, origPgno);

  57850.     sqlite3PagerUnrefNotNull(pPgOld);

  57851.   }

  57852. 

  57853.   if( needSyncPgno ){

  57854.     /* If needSyncPgno is non-zero, then the journal file needs to be 

  57855.     ** sync()ed before any data is written to database file page needSyncPgno.

  57856.     ** Currently, no such page exists in the page-cache and the 

  57857.     ** "is journaled" bitvec flag has been set. This needs to be remedied by

  57858.     ** loading the page into the pager-cache and setting the PGHDR_NEED_SYNC

  57859.     ** flag.

  57860.     **

  57861.     ** If the attempt to load the page into the page-cache fails, (due

  57862.     ** to a malloc() or IO failure), clear the bit in the pInJournal[]

  57863.     ** array. Otherwise, if the page is loaded and written again in

  57864.     ** this transaction, it may be written to the database file before

  57865.     ** it is synced into the journal file. This way, it may end up in

  57866.     ** the journal file twice, but that is not a problem.

  57867.     */

  57868.     PgHdr *pPgHdr;

  57869.     rc = sqlite3PagerGet(pPager, needSyncPgno, &pPgHdr, 0);

  57870.     if( rc!=SQLITE_OK ){

  57871.       if( needSyncPgno<=pPager->dbOrigSize ){

  57872.         assert( pPager->pTmpSpace!=0 );

  57873.         sqlite3BitvecClear(pPager->pInJournal, needSyncPgno, pPager->pTmpSpace);

  57874.       }

  57875.       return rc;

  57876.     }

  57877.     pPgHdr->flags |= PGHDR_NEED_SYNC;

  57878.     sqlite3PcacheMakeDirty(pPgHdr);

  57879.     sqlite3PagerUnrefNotNull(pPgHdr);

  57880.   }

  57881. 

  57882.   return SQLITE_OK;

  57883. }

  57884. #endif

  57885. 

  57886. /*

  57887. ** The page handle passed as the first argument refers to a dirty page 

  57888. ** with a page number other than iNew. This function changes the page's 

  57889. ** page number to iNew and sets the value of the PgHdr.flags field to 

  57890. ** the value passed as the third parameter.

  57891. */

  57892. SQLITE_PRIVATE void sqlite3PagerRekey(DbPage *pPg, Pgno iNew, u16 flags){

  57893.   assert( pPg->pgno!=iNew );

  57894.   pPg->flags = flags;

  57895.   sqlite3PcacheMove(pPg, iNew);

  57896. }

  57897. 

  57898. /*

  57899. ** Return a pointer to the data for the specified page.

  57900. */

  57901. SQLITE_PRIVATE void *sqlite3PagerGetData(DbPage *pPg){

  57902.   assert( pPg->nRef>0 || pPg->pPager->memDb );

  57903.   return pPg->pData;

  57904. }

  57905. 

  57906. /*

  57907. ** Return a pointer to the Pager.nExtra bytes of "extra" space 

  57908. ** allocated along with the specified page.

  57909. */

  57910. SQLITE_PRIVATE void *sqlite3PagerGetExtra(DbPage *pPg){

  57911.   return pPg->pExtra;

  57912. }

  57913. 

  57914. /*

  57915. ** Get/set the locking-mode for this pager. Parameter eMode must be one

  57916. ** of PAGER_LOCKINGMODE_QUERY, PAGER_LOCKINGMODE_NORMAL or 

  57917. ** PAGER_LOCKINGMODE_EXCLUSIVE. If the parameter is not _QUERY, then

  57918. ** the locking-mode is set to the value specified.

  57919. **

  57920. ** The returned value is either PAGER_LOCKINGMODE_NORMAL or

  57921. ** PAGER_LOCKINGMODE_EXCLUSIVE, indicating the current (possibly updated)

  57922. ** locking-mode.

  57923. */

  57924. SQLITE_PRIVATE int sqlite3PagerLockingMode(Pager *pPager, int eMode){

  57925.   assert( eMode==PAGER_LOCKINGMODE_QUERY

  57926.             || eMode==PAGER_LOCKINGMODE_NORMAL

  57927.             || eMode==PAGER_LOCKINGMODE_EXCLUSIVE );

  57928.   assert( PAGER_LOCKINGMODE_QUERY<0 );

  57929.   assert( PAGER_LOCKINGMODE_NORMAL>=0 && PAGER_LOCKINGMODE_EXCLUSIVE>=0 );

  57930.   assert( pPager->exclusiveMode || 0==sqlite3WalHeapMemory(pPager->pWal) );

  57931.   if( eMode>=0 && !pPager->tempFile && !sqlite3WalHeapMemory(pPager->pWal) ){

  57932.     pPager->exclusiveMode = (u8)eMode;

  57933.   }

  57934.   return (int)pPager->exclusiveMode;

  57935. }

  57936. 

  57937. /*

  57938. ** Set the journal-mode for this pager. Parameter eMode must be one of:

  57939. **

  57940. **    PAGER_JOURNALMODE_DELETE

  57941. **    PAGER_JOURNALMODE_TRUNCATE

  57942. **    PAGER_JOURNALMODE_PERSIST

  57943. **    PAGER_JOURNALMODE_OFF

  57944. **    PAGER_JOURNALMODE_MEMORY

  57945. **    PAGER_JOURNALMODE_WAL

  57946. **

  57947. ** The journalmode is set to the value specified if the change is allowed.

  57948. ** The change may be disallowed for the following reasons:

  57949. **

  57950. **   *  An in-memory database can only have its journal_mode set to _OFF

  57951. **      or _MEMORY.

  57952. **

  57953. **   *  Temporary databases cannot have _WAL journalmode.

  57954. **

  57955. ** The returned indicate the current (possibly updated) journal-mode.

  57956. */

  57957. SQLITE_PRIVATE int sqlite3PagerSetJournalMode(Pager *pPager, int eMode){

  57958.   u8 eOld = pPager->journalMode;    /* Prior journalmode */

  57959. 

  57960.   /* The eMode parameter is always valid */

  57961.   assert(      eMode==PAGER_JOURNALMODE_DELETE

  57962.             || eMode==PAGER_JOURNALMODE_TRUNCATE

  57963.             || eMode==PAGER_JOURNALMODE_PERSIST

  57964.             || eMode==PAGER_JOURNALMODE_OFF 

  57965.             || eMode==PAGER_JOURNALMODE_WAL 

  57966.             || eMode==PAGER_JOURNALMODE_MEMORY );

  57967. 

  57968.   /* This routine is only called from the OP_JournalMode opcode, and

  57969.   ** the logic there will never allow a temporary file to be changed

  57970.   ** to WAL mode.

  57971.   */

  57972.   assert( pPager->tempFile==0 || eMode!=PAGER_JOURNALMODE_WAL );

  57973. 

  57974.   /* Do allow the journalmode of an in-memory database to be set to

  57975.   ** anything other than MEMORY or OFF

  57976.   */

  57977.   if( MEMDB ){

  57978.     assert( eOld==PAGER_JOURNALMODE_MEMORY || eOld==PAGER_JOURNALMODE_OFF );

  57979.     if( eMode!=PAGER_JOURNALMODE_MEMORY && eMode!=PAGER_JOURNALMODE_OFF ){

  57980.       eMode = eOld;

  57981.     }

  57982.   }

  57983. 

  57984.   if( eMode!=eOld ){

  57985. 

  57986.     /* Change the journal mode. */

  57987.     assert( pPager->eState!=PAGER_ERROR );

  57988.     pPager->journalMode = (u8)eMode;

  57989. 

  57990.     /* When transistioning from TRUNCATE or PERSIST to any other journal

  57991.     ** mode except WAL, unless the pager is in locking_mode=exclusive mode,

  57992.     ** delete the journal file.

  57993.     */

  57994.     assert( (PAGER_JOURNALMODE_TRUNCATE & 5)==1 );

  57995.     assert( (PAGER_JOURNALMODE_PERSIST & 5)==1 );

  57996.     assert( (PAGER_JOURNALMODE_DELETE & 5)==0 );

  57997.     assert( (PAGER_JOURNALMODE_MEMORY & 5)==4 );

  57998.     assert( (PAGER_JOURNALMODE_OFF & 5)==0 );

  57999.     assert( (PAGER_JOURNALMODE_WAL & 5)==5 );

  58000. 

  58001.     assert( isOpen(pPager->fd) || pPager->exclusiveMode );

  58002.     if( !pPager->exclusiveMode && (eOld & 5)==1 && (eMode & 1)==0 ){

  58003. 

  58004.       /* In this case we would like to delete the journal file. If it is

  58005.       ** not possible, then that is not a problem. Deleting the journal file

  58006.       ** here is an optimization only.

  58007.       **

  58008.       ** Before deleting the journal file, obtain a RESERVED lock on the

  58009.       ** database file. This ensures that the journal file is not deleted

  58010.       ** while it is in use by some other client.

  58011.       */

  58012.       sqlite3OsClose(pPager->jfd);

  58013.       if( pPager->eLock>=RESERVED_LOCK ){

  58014.         sqlite3OsDelete(pPager->pVfs, pPager->zJournal, 0);

  58015.       }else{

  58016.         int rc = SQLITE_OK;

  58017.         int state = pPager->eState;

  58018.         assert( state==PAGER_OPEN || state==PAGER_READER );

  58019.         if( state==PAGER_OPEN ){

  58020.           rc = sqlite3PagerSharedLock(pPager);

  58021.         }

  58022.         if( pPager->eState==PAGER_READER ){

  58023.           assert( rc==SQLITE_OK );

  58024.           rc = pagerLockDb(pPager, RESERVED_LOCK);

  58025.         }

  58026.         if( rc==SQLITE_OK ){

  58027.           sqlite3OsDelete(pPager->pVfs, pPager->zJournal, 0);

  58028.         }

  58029.         if( rc==SQLITE_OK && state==PAGER_READER ){

  58030.           pagerUnlockDb(pPager, SHARED_LOCK);

  58031.         }else if( state==PAGER_OPEN ){

  58032.           pager_unlock(pPager);

  58033.         }

  58034.         assert( state==pPager->eState );

  58035.       }

  58036.     }else if( eMode==PAGER_JOURNALMODE_OFF ){

  58037.       sqlite3OsClose(pPager->jfd);

  58038.     }

  58039.   }

  58040. 

  58041.   /* Return the new journal mode */

  58042.   return (int)pPager->journalMode;

  58043. }

  58044. 

  58045. /*

  58046. ** Return the current journal mode.

  58047. */

  58048. SQLITE_PRIVATE int sqlite3PagerGetJournalMode(Pager *pPager){

  58049.   return (int)pPager->journalMode;

  58050. }

  58051. 

  58052. /*

  58053. ** Return TRUE if the pager is in a state where it is OK to change the

  58054. ** journalmode.  Journalmode changes can only happen when the database

  58055. ** is unmodified.

  58056. */

  58057. SQLITE_PRIVATE int sqlite3PagerOkToChangeJournalMode(Pager *pPager){

  58058.   assert( assert_pager_state(pPager) );

  58059.   if( pPager->eState>=PAGER_WRITER_CACHEMOD ) return 0;

  58060.   if( NEVER(isOpen(pPager->jfd) && pPager->journalOff>0) ) return 0;

  58061.   return 1;

  58062. }

  58063. 

  58064. /*

  58065. ** Get/set the size-limit used for persistent journal files.

  58066. **

  58067. ** Setting the size limit to -1 means no limit is enforced.

  58068. ** An attempt to set a limit smaller than -1 is a no-op.

  58069. */

  58070. SQLITE_PRIVATE i64 sqlite3PagerJournalSizeLimit(Pager *pPager, i64 iLimit){

  58071.   if( iLimit>=-1 ){

  58072.     pPager->journalSizeLimit = iLimit;

  58073.     sqlite3WalLimit(pPager->pWal, iLimit);

  58074.   }

  58075.   return pPager->journalSizeLimit;

  58076. }

  58077. 

  58078. /*

  58079. ** Return a pointer to the pPager->pBackup variable. The backup module

  58080. ** in backup.c maintains the content of this variable. This module

  58081. ** uses it opaquely as an argument to sqlite3BackupRestart() and

  58082. ** sqlite3BackupUpdate() only.

  58083. */

  58084. SQLITE_PRIVATE sqlite3_backup **sqlite3PagerBackupPtr(Pager *pPager){

  58085.   return &pPager->pBackup;

  58086. }

  58087. 

  58088. #ifndef SQLITE_OMIT_VACUUM

  58089. /*

  58090. ** Unless this is an in-memory or temporary database, clear the pager cache.

  58091. */

  58092. SQLITE_PRIVATE void sqlite3PagerClearCache(Pager *pPager){

  58093.   assert( MEMDB==0 || pPager->tempFile );

  58094.   if( pPager->tempFile==0 ) pager_reset(pPager);

  58095. }

  58096. #endif

  58097. 

  58098. 

  58099. #ifndef SQLITE_OMIT_WAL

  58100. /*

  58101. ** This function is called when the user invokes "PRAGMA wal_checkpoint",

  58102. ** "PRAGMA wal_blocking_checkpoint" or calls the sqlite3_wal_checkpoint()

  58103. ** or wal_blocking_checkpoint() API functions.

  58104. **

  58105. ** Parameter eMode is one of SQLITE_CHECKPOINT_PASSIVE, FULL or RESTART.

  58106. */

  58107. SQLITE_PRIVATE int sqlite3PagerCheckpoint(

  58108.   Pager *pPager,                  /* Checkpoint on this pager */

  58109.   sqlite3 *db,                    /* Db handle used to check for interrupts */

  58110.   int eMode,                      /* Type of checkpoint */

  58111.   int *pnLog,                     /* OUT: Final number of frames in log */

  58112.   int *pnCkpt                     /* OUT: Final number of checkpointed frames */

  58113. ){

  58114.   int rc = SQLITE_OK;

  58115.   if( pPager->pWal ){

  58116.     rc = sqlite3WalCheckpoint(pPager->pWal, db, eMode,

  58117.         (eMode==SQLITE_CHECKPOINT_PASSIVE ? 0 : pPager->xBusyHandler),

  58118.         pPager->pBusyHandlerArg,

  58119.         pPager->walSyncFlags, pPager->pageSize, (u8 *)pPager->pTmpSpace,

  58120.         pnLog, pnCkpt

  58121.     );

  58122.     sqlite3PagerResetLockTimeout(pPager);

  58123.   }

  58124.   return rc;

  58125. }

  58126. 

  58127. SQLITE_PRIVATE int sqlite3PagerWalCallback(Pager *pPager){

  58128.   return sqlite3WalCallback(pPager->pWal);

  58129. }

  58130. 

  58131. /*

  58132. ** Return true if the underlying VFS for the given pager supports the

  58133. ** primitives necessary for write-ahead logging.

  58134. */

  58135. SQLITE_PRIVATE int sqlite3PagerWalSupported(Pager *pPager){

  58136.   const sqlite3_io_methods *pMethods = pPager->fd->pMethods;

  58137.   if( pPager->noLock ) return 0;

  58138.   return pPager->exclusiveMode || (pMethods->iVersion>=2 && pMethods->xShmMap);

  58139. }

  58140. 

  58141. /*

  58142. ** Attempt to take an exclusive lock on the database file. If a PENDING lock

  58143. ** is obtained instead, immediately release it.

  58144. */

  58145. static int pagerExclusiveLock(Pager *pPager){

  58146.   int rc;                         /* Return code */

  58147. 

  58148.   assert( pPager->eLock==SHARED_LOCK || pPager->eLock==EXCLUSIVE_LOCK );

  58149.   rc = pagerLockDb(pPager, EXCLUSIVE_LOCK);

  58150.   if( rc!=SQLITE_OK ){

  58151.     /* If the attempt to grab the exclusive lock failed, release the 

  58152.     ** pending lock that may have been obtained instead.  */

  58153.     pagerUnlockDb(pPager, SHARED_LOCK);

  58154.   }

  58155. 

  58156.   return rc;

  58157. }

  58158. 

  58159. /*

  58160. ** Call sqlite3WalOpen() to open the WAL handle. If the pager is in 

  58161. ** exclusive-locking mode when this function is called, take an EXCLUSIVE

  58162. ** lock on the database file and use heap-memory to store the wal-index

  58163. ** in. Otherwise, use the normal shared-memory.

  58164. */

  58165. static int pagerOpenWal(Pager *pPager){

  58166.   int rc = SQLITE_OK;

  58167. 

  58168.   assert( pPager->pWal==0 && pPager->tempFile==0 );

  58169.   assert( pPager->eLock==SHARED_LOCK || pPager->eLock==EXCLUSIVE_LOCK );

  58170. 

  58171.   /* If the pager is already in exclusive-mode, the WAL module will use 

  58172.   ** heap-memory for the wal-index instead of the VFS shared-memory 

  58173.   ** implementation. Take the exclusive lock now, before opening the WAL

  58174.   ** file, to make sure this is safe.

  58175.   */

  58176.   if( pPager->exclusiveMode ){

  58177.     rc = pagerExclusiveLock(pPager);

  58178.   }

  58179. 

  58180.   /* Open the connection to the log file. If this operation fails, 

  58181.   ** (e.g. due to malloc() failure), return an error code.

  58182.   */

  58183.   if( rc==SQLITE_OK ){

  58184.     rc = sqlite3WalOpen(pPager->pVfs,

  58185.         pPager->fd, pPager->zWal, pPager->exclusiveMode,

  58186.         pPager->journalSizeLimit, &pPager->pWal

  58187.     );

  58188.   }

  58189.   pagerFixMaplimit(pPager);

  58190. 

  58191.   return rc;

  58192. }

  58193. 

  58194. 

  58195. /*

  58196. ** The caller must be holding a SHARED lock on the database file to call

  58197. ** this function.

  58198. **

  58199. ** If the pager passed as the first argument is open on a real database

  58200. ** file (not a temp file or an in-memory database), and the WAL file

  58201. ** is not already open, make an attempt to open it now. If successful,

  58202. ** return SQLITE_OK. If an error occurs or the VFS used by the pager does 

  58203. ** not support the xShmXXX() methods, return an error code. *pbOpen is

  58204. ** not modified in either case.

  58205. **

  58206. ** If the pager is open on a temp-file (or in-memory database), or if

  58207. ** the WAL file is already open, set *pbOpen to 1 and return SQLITE_OK

  58208. ** without doing anything.

  58209. */

  58210. SQLITE_PRIVATE int sqlite3PagerOpenWal(

  58211.   Pager *pPager,                  /* Pager object */

  58212.   int *pbOpen                     /* OUT: Set to true if call is a no-op */

  58213. ){

  58214.   int rc = SQLITE_OK;             /* Return code */

  58215. 

  58216.   assert( assert_pager_state(pPager) );

  58217.   assert( pPager->eState==PAGER_OPEN   || pbOpen );

  58218.   assert( pPager->eState==PAGER_READER || !pbOpen );

  58219.   assert( pbOpen==0 || *pbOpen==0 );

  58220.   assert( pbOpen!=0 || (!pPager->tempFile && !pPager->pWal) );

  58221. 

  58222.   if( !pPager->tempFile && !pPager->pWal ){

  58223.     if( !sqlite3PagerWalSupported(pPager) ) return SQLITE_CANTOPEN;

  58224. 

  58225.     /* Close any rollback journal previously open */

  58226.     sqlite3OsClose(pPager->jfd);

  58227. 

  58228.     rc = pagerOpenWal(pPager);

  58229.     if( rc==SQLITE_OK ){

  58230.       pPager->journalMode = PAGER_JOURNALMODE_WAL;

  58231.       pPager->eState = PAGER_OPEN;

  58232.     }

  58233.   }else{

  58234.     *pbOpen = 1;

  58235.   }

  58236. 

  58237.   return rc;

  58238. }

  58239. 

  58240. /*

  58241. ** This function is called to close the connection to the log file prior

  58242. ** to switching from WAL to rollback mode.

  58243. **

  58244. ** Before closing the log file, this function attempts to take an 

  58245. ** EXCLUSIVE lock on the database file. If this cannot be obtained, an

  58246. ** error (SQLITE_BUSY) is returned and the log connection is not closed.

  58247. ** If successful, the EXCLUSIVE lock is not released before returning.

  58248. */

  58249. SQLITE_PRIVATE int sqlite3PagerCloseWal(Pager *pPager, sqlite3 *db){

  58250.   int rc = SQLITE_OK;

  58251. 

  58252.   assert( pPager->journalMode==PAGER_JOURNALMODE_WAL );

  58253. 

  58254.   /* If the log file is not already open, but does exist in the file-system,

  58255.   ** it may need to be checkpointed before the connection can switch to

  58256.   ** rollback mode. Open it now so this can happen.

  58257.   */

  58258.   if( !pPager->pWal ){

  58259.     int logexists = 0;

  58260.     rc = pagerLockDb(pPager, SHARED_LOCK);

  58261.     if( rc==SQLITE_OK ){

  58262.       rc = sqlite3OsAccess(

  58263.           pPager->pVfs, pPager->zWal, SQLITE_ACCESS_EXISTS, &logexists

  58264.       );

  58265.     }

  58266.     if( rc==SQLITE_OK && logexists ){

  58267.       rc = pagerOpenWal(pPager);

  58268.     }

  58269.   }

  58270.     

  58271.   /* Checkpoint and close the log. Because an EXCLUSIVE lock is held on

  58272.   ** the database file, the log and log-summary files will be deleted.

  58273.   */

  58274.   if( rc==SQLITE_OK && pPager->pWal ){

  58275.     rc = pagerExclusiveLock(pPager);

  58276.     if( rc==SQLITE_OK ){

  58277.       rc = sqlite3WalClose(pPager->pWal, db, pPager->walSyncFlags,

  58278.                            pPager->pageSize, (u8*)pPager->pTmpSpace);

  58279.       pPager->pWal = 0;

  58280.       pagerFixMaplimit(pPager);

  58281.       if( rc && !pPager->exclusiveMode ) pagerUnlockDb(pPager, SHARED_LOCK);

  58282.     }

  58283.   }

  58284.   return rc;

  58285. }

  58286. 

  58287. #ifdef SQLITE_ENABLE_SNAPSHOT

  58288. /*

  58289. ** If this is a WAL database, obtain a snapshot handle for the snapshot

  58290. ** currently open. Otherwise, return an error.

  58291. */

  58292. SQLITE_PRIVATE int sqlite3PagerSnapshotGet(Pager *pPager, sqlite3_snapshot **ppSnapshot){

  58293.   int rc = SQLITE_ERROR;

  58294.   if( pPager->pWal ){

  58295.     rc = sqlite3WalSnapshotGet(pPager->pWal, ppSnapshot);

  58296.   }

  58297.   return rc;

  58298. }

  58299. 

  58300. /*

  58301. ** If this is a WAL database, store a pointer to pSnapshot. Next time a

  58302. ** read transaction is opened, attempt to read from the snapshot it 

  58303. ** identifies. If this is not a WAL database, return an error.

  58304. */

  58305. SQLITE_PRIVATE int sqlite3PagerSnapshotOpen(Pager *pPager, sqlite3_snapshot *pSnapshot){

  58306.   int rc = SQLITE_OK;

  58307.   if( pPager->pWal ){

  58308.     sqlite3WalSnapshotOpen(pPager->pWal, pSnapshot);

  58309.   }else{

  58310.     rc = SQLITE_ERROR;

  58311.   }

  58312.   return rc;

  58313. }

  58314. 

  58315. /*

  58316. ** If this is a WAL database, call sqlite3WalSnapshotRecover(). If this 

  58317. ** is not a WAL database, return an error.

  58318. */

  58319. SQLITE_PRIVATE int sqlite3PagerSnapshotRecover(Pager *pPager){

  58320.   int rc;

  58321.   if( pPager->pWal ){

  58322.     rc = sqlite3WalSnapshotRecover(pPager->pWal);

  58323.   }else{

  58324.     rc = SQLITE_ERROR;

  58325.   }

  58326.   return rc;

  58327. }

  58328. 

  58329. /*

  58330. ** The caller currently has a read transaction open on the database.

  58331. ** If this is not a WAL database, SQLITE_ERROR is returned. Otherwise,

  58332. ** this function takes a SHARED lock on the CHECKPOINTER slot and then

  58333. ** checks if the snapshot passed as the second argument is still 

  58334. ** available. If so, SQLITE_OK is returned.

  58335. **

  58336. ** If the snapshot is not available, SQLITE_ERROR is returned. Or, if

  58337. ** the CHECKPOINTER lock cannot be obtained, SQLITE_BUSY. If any error

  58338. ** occurs (any value other than SQLITE_OK is returned), the CHECKPOINTER

  58339. ** lock is released before returning.

  58340. */

  58341. SQLITE_PRIVATE int sqlite3PagerSnapshotCheck(Pager *pPager, sqlite3_snapshot *pSnapshot){

  58342.   int rc;

  58343.   if( pPager->pWal ){

  58344.     rc = sqlite3WalSnapshotCheck(pPager->pWal, pSnapshot);

  58345.   }else{

  58346.     rc = SQLITE_ERROR;

  58347.   }

  58348.   return rc;

  58349. }

  58350. 

  58351. /*

  58352. ** Release a lock obtained by an earlier successful call to

  58353. ** sqlite3PagerSnapshotCheck().

  58354. */

  58355. SQLITE_PRIVATE void sqlite3PagerSnapshotUnlock(Pager *pPager){

  58356.   assert( pPager->pWal );

  58357.   sqlite3WalSnapshotUnlock(pPager->pWal);

  58358. }

  58359. 

  58360. #endif /* SQLITE_ENABLE_SNAPSHOT */

  58361. #endif /* !SQLITE_OMIT_WAL */

  58362. 

  58363. #ifdef SQLITE_ENABLE_ZIPVFS

  58364. /*

  58365. ** A read-lock must be held on the pager when this function is called. If

  58366. ** the pager is in WAL mode and the WAL file currently contains one or more

  58367. ** frames, return the size in bytes of the page images stored within the

  58368. ** WAL frames. Otherwise, if this is not a WAL database or the WAL file

  58369. ** is empty, return 0.

  58370. */

  58371. SQLITE_PRIVATE int sqlite3PagerWalFramesize(Pager *pPager){

  58372.   assert( pPager->eState>=PAGER_READER );

  58373.   return sqlite3WalFramesize(pPager->pWal);

  58374. }

  58375. #endif

  58376. 

  58377. #endif /* SQLITE_OMIT_DISKIO */

  58378. 

  58379. /************** End of pager.c ***********************************************/

  58380. /************** Begin file wal.c *********************************************/

  58381. /*

  58382. ** 2010 February 1

  58383. **

  58384. ** The author disclaims copyright to this source code.  In place of

  58385. ** a legal notice, here is a blessing:

  58386. **

  58387. **    May you do good and not evil.

  58388. **    May you find forgiveness for yourself and forgive others.

  58389. **    May you share freely, never taking more than you give.

  58390. **

  58391. *************************************************************************

  58392. **

  58393. ** This file contains the implementation of a write-ahead log (WAL) used in 

  58394. ** "journal_mode=WAL" mode.

  58395. **

  58396. ** WRITE-AHEAD LOG (WAL) FILE FORMAT

  58397. **

  58398. ** A WAL file consists of a header followed by zero or more "frames".

  58399. ** Each frame records the revised content of a single page from the

  58400. ** database file.  All changes to the database are recorded by writing

  58401. ** frames into the WAL.  Transactions commit when a frame is written that

  58402. ** contains a commit marker.  A single WAL can and usually does record 

  58403. ** multiple transactions.  Periodically, the content of the WAL is

  58404. ** transferred back into the database file in an operation called a

  58405. ** "checkpoint".

  58406. **

  58407. ** A single WAL file can be used multiple times.  In other words, the

  58408. ** WAL can fill up with frames and then be checkpointed and then new

  58409. ** frames can overwrite the old ones.  A WAL always grows from beginning

  58410. ** toward the end.  Checksums and counters attached to each frame are

  58411. ** used to determine which frames within the WAL are valid and which

  58412. ** are leftovers from prior checkpoints.

  58413. **

  58414. ** The WAL header is 32 bytes in size and consists of the following eight

  58415. ** big-endian 32-bit unsigned integer values:

  58416. **

  58417. **     0: Magic number.  0x377f0682 or 0x377f0683

  58418. **     4: File format version.  Currently 3007000

  58419. **     8: Database page size.  Example: 1024

  58420. **    12: Checkpoint sequence number

  58421. **    16: Salt-1, random integer incremented with each checkpoint

  58422. **    20: Salt-2, a different random integer changing with each ckpt

  58423. **    24: Checksum-1 (first part of checksum for first 24 bytes of header).

  58424. **    28: Checksum-2 (second part of checksum for first 24 bytes of header).

  58425. **

  58426. ** Immediately following the wal-header are zero or more frames. Each

  58427. ** frame consists of a 24-byte frame-header followed by a <page-size> bytes

  58428. ** of page data. The frame-header is six big-endian 32-bit unsigned 

  58429. ** integer values, as follows:

  58430. **

  58431. **     0: Page number.

  58432. **     4: For commit records, the size of the database image in pages 

  58433. **        after the commit. For all other records, zero.

  58434. **     8: Salt-1 (copied from the header)

  58435. **    12: Salt-2 (copied from the header)

  58436. **    16: Checksum-1.

  58437. **    20: Checksum-2.

  58438. **

  58439. ** A frame is considered valid if and only if the following conditions are

  58440. ** true:

  58441. **

  58442. **    (1) The salt-1 and salt-2 values in the frame-header match

  58443. **        salt values in the wal-header

  58444. **

  58445. **    (2) The checksum values in the final 8 bytes of the frame-header

  58446. **        exactly match the checksum computed consecutively on the

  58447. **        WAL header and the first 8 bytes and the content of all frames

  58448. **        up to and including the current frame.

  58449. **

  58450. ** The checksum is computed using 32-bit big-endian integers if the

  58451. ** magic number in the first 4 bytes of the WAL is 0x377f0683 and it

  58452. ** is computed using little-endian if the magic number is 0x377f0682.

  58453. ** The checksum values are always stored in the frame header in a

  58454. ** big-endian format regardless of which byte order is used to compute

  58455. ** the checksum.  The checksum is computed by interpreting the input as

  58456. ** an even number of unsigned 32-bit integers: x[0] through x[N].  The

  58457. ** algorithm used for the checksum is as follows:

  58458. ** 

  58459. **   for i from 0 to n-1 step 2:

  58460. **     s0 += x[i] + s1;

  58461. **     s1 += x[i+1] + s0;

  58462. **   endfor

  58463. **

  58464. ** Note that s0 and s1 are both weighted checksums using fibonacci weights

  58465. ** in reverse order (the largest fibonacci weight occurs on the first element

  58466. ** of the sequence being summed.)  The s1 value spans all 32-bit 

  58467. ** terms of the sequence whereas s0 omits the final term.

  58468. **

  58469. ** On a checkpoint, the WAL is first VFS.xSync-ed, then valid content of the

  58470. ** WAL is transferred into the database, then the database is VFS.xSync-ed.

  58471. ** The VFS.xSync operations serve as write barriers - all writes launched

  58472. ** before the xSync must complete before any write that launches after the

  58473. ** xSync begins.

  58474. **

  58475. ** After each checkpoint, the salt-1 value is incremented and the salt-2

  58476. ** value is randomized.  This prevents old and new frames in the WAL from

  58477. ** being considered valid at the same time and being checkpointing together

  58478. ** following a crash.

  58479. **

  58480. ** READER ALGORITHM

  58481. **

  58482. ** To read a page from the database (call it page number P), a reader

  58483. ** first checks the WAL to see if it contains page P.  If so, then the

  58484. ** last valid instance of page P that is a followed by a commit frame

  58485. ** or is a commit frame itself becomes the value read.  If the WAL

  58486. ** contains no copies of page P that are valid and which are a commit

  58487. ** frame or are followed by a commit frame, then page P is read from

  58488. ** the database file.

  58489. **

  58490. ** To start a read transaction, the reader records the index of the last

  58491. ** valid frame in the WAL.  The reader uses this recorded "mxFrame" value

  58492. ** for all subsequent read operations.  New transactions can be appended

  58493. ** to the WAL, but as long as the reader uses its original mxFrame value

  58494. ** and ignores the newly appended content, it will see a consistent snapshot

  58495. ** of the database from a single point in time.  This technique allows

  58496. ** multiple concurrent readers to view different versions of the database

  58497. ** content simultaneously.

  58498. **

  58499. ** The reader algorithm in the previous paragraphs works correctly, but 

  58500. ** because frames for page P can appear anywhere within the WAL, the

  58501. ** reader has to scan the entire WAL looking for page P frames.  If the

  58502. ** WAL is large (multiple megabytes is typical) that scan can be slow,

  58503. ** and read performance suffers.  To overcome this problem, a separate

  58504. ** data structure called the wal-index is maintained to expedite the

  58505. ** search for frames of a particular page.

  58506. ** 

  58507. ** WAL-INDEX FORMAT

  58508. **

  58509. ** Conceptually, the wal-index is shared memory, though VFS implementations

  58510. ** might choose to implement the wal-index using a mmapped file.  Because

  58511. ** the wal-index is shared memory, SQLite does not support journal_mode=WAL 

  58512. ** on a network filesystem.  All users of the database must be able to

  58513. ** share memory.

  58514. **

  58515. ** In the default unix and windows implementation, the wal-index is a mmapped

  58516. ** file whose name is the database name with a "-shm" suffix added.  For that

  58517. ** reason, the wal-index is sometimes called the "shm" file.

  58518. **

  58519. ** The wal-index is transient.  After a crash, the wal-index can (and should

  58520. ** be) reconstructed from the original WAL file.  In fact, the VFS is required

  58521. ** to either truncate or zero the header of the wal-index when the last

  58522. ** connection to it closes.  Because the wal-index is transient, it can

  58523. ** use an architecture-specific format; it does not have to be cross-platform.

  58524. ** Hence, unlike the database and WAL file formats which store all values

  58525. ** as big endian, the wal-index can store multi-byte values in the native

  58526. ** byte order of the host computer.

  58527. **

  58528. ** The purpose of the wal-index is to answer this question quickly:  Given

  58529. ** a page number P and a maximum frame index M, return the index of the 

  58530. ** last frame in the wal before frame M for page P in the WAL, or return

  58531. ** NULL if there are no frames for page P in the WAL prior to M.

  58532. **

  58533. ** The wal-index consists of a header region, followed by an one or

  58534. ** more index blocks.  

  58535. **

  58536. ** The wal-index header contains the total number of frames within the WAL

  58537. ** in the mxFrame field.

  58538. **

  58539. ** Each index block except for the first contains information on 

  58540. ** HASHTABLE_NPAGE frames. The first index block contains information on

  58541. ** HASHTABLE_NPAGE_ONE frames. The values of HASHTABLE_NPAGE_ONE and 

  58542. ** HASHTABLE_NPAGE are selected so that together the wal-index header and

  58543. ** first index block are the same size as all other index blocks in the

  58544. ** wal-index.

  58545. **

  58546. ** Each index block contains two sections, a page-mapping that contains the

  58547. ** database page number associated with each wal frame, and a hash-table 

  58548. ** that allows readers to query an index block for a specific page number.

  58549. ** The page-mapping is an array of HASHTABLE_NPAGE (or HASHTABLE_NPAGE_ONE

  58550. ** for the first index block) 32-bit page numbers. The first entry in the 

  58551. ** first index-block contains the database page number corresponding to the

  58552. ** first frame in the WAL file. The first entry in the second index block

  58553. ** in the WAL file corresponds to the (HASHTABLE_NPAGE_ONE+1)th frame in

  58554. ** the log, and so on.

  58555. **

  58556. ** The last index block in a wal-index usually contains less than the full

  58557. ** complement of HASHTABLE_NPAGE (or HASHTABLE_NPAGE_ONE) page-numbers,

  58558. ** depending on the contents of the WAL file. This does not change the

  58559. ** allocated size of the page-mapping array - the page-mapping array merely

  58560. ** contains unused entries.

  58561. **

  58562. ** Even without using the hash table, the last frame for page P

  58563. ** can be found by scanning the page-mapping sections of each index block

  58564. ** starting with the last index block and moving toward the first, and

  58565. ** within each index block, starting at the end and moving toward the

  58566. ** beginning.  The first entry that equals P corresponds to the frame

  58567. ** holding the content for that page.

  58568. **

  58569. ** The hash table consists of HASHTABLE_NSLOT 16-bit unsigned integers.

  58570. ** HASHTABLE_NSLOT = 2*HASHTABLE_NPAGE, and there is one entry in the

  58571. ** hash table for each page number in the mapping section, so the hash 

  58572. ** table is never more than half full.  The expected number of collisions 

  58573. ** prior to finding a match is 1.  Each entry of the hash table is an

  58574. ** 1-based index of an entry in the mapping section of the same

  58575. ** index block.   Let K be the 1-based index of the largest entry in

  58576. ** the mapping section.  (For index blocks other than the last, K will

  58577. ** always be exactly HASHTABLE_NPAGE (4096) and for the last index block

  58578. ** K will be (mxFrame%HASHTABLE_NPAGE).)  Unused slots of the hash table

  58579. ** contain a value of 0.

  58580. **

  58581. ** To look for page P in the hash table, first compute a hash iKey on

  58582. ** P as follows:

  58583. **

  58584. **      iKey = (P * 383) % HASHTABLE_NSLOT

  58585. **

  58586. ** Then start scanning entries of the hash table, starting with iKey

  58587. ** (wrapping around to the beginning when the end of the hash table is

  58588. ** reached) until an unused hash slot is found. Let the first unused slot

  58589. ** be at index iUnused.  (iUnused might be less than iKey if there was

  58590. ** wrap-around.) Because the hash table is never more than half full,

  58591. ** the search is guaranteed to eventually hit an unused entry.  Let 

  58592. ** iMax be the value between iKey and iUnused, closest to iUnused,

  58593. ** where aHash[iMax]==P.  If there is no iMax entry (if there exists

  58594. ** no hash slot such that aHash[i]==p) then page P is not in the

  58595. ** current index block.  Otherwise the iMax-th mapping entry of the

  58596. ** current index block corresponds to the last entry that references 

  58597. ** page P.

  58598. **

  58599. ** A hash search begins with the last index block and moves toward the

  58600. ** first index block, looking for entries corresponding to page P.  On

  58601. ** average, only two or three slots in each index block need to be

  58602. ** examined in order to either find the last entry for page P, or to

  58603. ** establish that no such entry exists in the block.  Each index block

  58604. ** holds over 4000 entries.  So two or three index blocks are sufficient

  58605. ** to cover a typical 10 megabyte WAL file, assuming 1K pages.  8 or 10

  58606. ** comparisons (on average) suffice to either locate a frame in the

  58607. ** WAL or to establish that the frame does not exist in the WAL.  This

  58608. ** is much faster than scanning the entire 10MB WAL.

  58609. **

  58610. ** Note that entries are added in order of increasing K.  Hence, one

  58611. ** reader might be using some value K0 and a second reader that started

  58612. ** at a later time (after additional transactions were added to the WAL

  58613. ** and to the wal-index) might be using a different value K1, where K1>K0.

  58614. ** Both readers can use the same hash table and mapping section to get

  58615. ** the correct result.  There may be entries in the hash table with

  58616. ** K>K0 but to the first reader, those entries will appear to be unused

  58617. ** slots in the hash table and so the first reader will get an answer as

  58618. ** if no values greater than K0 had ever been inserted into the hash table

  58619. ** in the first place - which is what reader one wants.  Meanwhile, the

  58620. ** second reader using K1 will see additional values that were inserted

  58621. ** later, which is exactly what reader two wants.  

  58622. **

  58623. ** When a rollback occurs, the value of K is decreased. Hash table entries

  58624. ** that correspond to frames greater than the new K value are removed

  58625. ** from the hash table at this point.

  58626. */

  58627. #ifndef SQLITE_OMIT_WAL

  58628. 

  58629. /* #include "wal.h" */

  58630. 

  58631. /*

  58632. ** Trace output macros

  58633. */

  58634. #if defined(SQLITE_TEST) && defined(SQLITE_DEBUG)

  58635. SQLITE_PRIVATE int sqlite3WalTrace = 0;

  58636. # define WALTRACE(X)  if(sqlite3WalTrace) sqlite3DebugPrintf X

  58637. #else

  58638. # define WALTRACE(X)

  58639. #endif

  58640. 

  58641. /*

  58642. ** WAL mode depends on atomic aligned 32-bit loads and stores in a few

  58643. ** places.  The following macros try to make this explicit.

  58644. */

  58645. #if GCC_VESRION>=5004000

  58646. # define AtomicLoad(PTR)       __atomic_load_n((PTR),__ATOMIC_RELAXED)

  58647. # define AtomicStore(PTR,VAL)  __atomic_store_n((PTR),(VAL),__ATOMIC_RELAXED)

  58648. #else

  58649. # define AtomicLoad(PTR)       (*(PTR))

  58650. # define AtomicStore(PTR,VAL)  (*(PTR) = (VAL))

  58651. #endif

  58652. 

  58653. /*

  58654. ** The maximum (and only) versions of the wal and wal-index formats

  58655. ** that may be interpreted by this version of SQLite.

  58656. **

  58657. ** If a client begins recovering a WAL file and finds that (a) the checksum

  58658. ** values in the wal-header are correct and (b) the version field is not

  58659. ** WAL_MAX_VERSION, recovery fails and SQLite returns SQLITE_CANTOPEN.

  58660. **

  58661. ** Similarly, if a client successfully reads a wal-index header (i.e. the 

  58662. ** checksum test is successful) and finds that the version field is not

  58663. ** WALINDEX_MAX_VERSION, then no read-transaction is opened and SQLite

  58664. ** returns SQLITE_CANTOPEN.

  58665. */

  58666. #define WAL_MAX_VERSION      3007000

  58667. #define WALINDEX_MAX_VERSION 3007000

  58668. 

  58669. /*

  58670. ** Index numbers for various locking bytes.   WAL_NREADER is the number

  58671. ** of available reader locks and should be at least 3.  The default

  58672. ** is SQLITE_SHM_NLOCK==8 and  WAL_NREADER==5.

  58673. **

  58674. ** Technically, the various VFSes are free to implement these locks however

  58675. ** they see fit.  However, compatibility is encouraged so that VFSes can

  58676. ** interoperate.  The standard implemention used on both unix and windows

  58677. ** is for the index number to indicate a byte offset into the

  58678. ** WalCkptInfo.aLock[] array in the wal-index header.  In other words, all

  58679. ** locks are on the shm file.  The WALINDEX_LOCK_OFFSET constant (which

  58680. ** should be 120) is the location in the shm file for the first locking

  58681. ** byte.

  58682. */

  58683. #define WAL_WRITE_LOCK         0

  58684. #define WAL_ALL_BUT_WRITE      1

  58685. #define WAL_CKPT_LOCK          1

  58686. #define WAL_RECOVER_LOCK       2

  58687. #define WAL_READ_LOCK(I)       (3+(I))

  58688. #define WAL_NREADER            (SQLITE_SHM_NLOCK-3)

  58689. 

  58690. 

  58691. /* Object declarations */

  58692. typedef struct WalIndexHdr WalIndexHdr;

  58693. typedef struct WalIterator WalIterator;

  58694. typedef struct WalCkptInfo WalCkptInfo;

  58695. 

  58696. 

  58697. /*

  58698. ** The following object holds a copy of the wal-index header content.

  58699. **

  58700. ** The actual header in the wal-index consists of two copies of this

  58701. ** object followed by one instance of the WalCkptInfo object.

  58702. ** For all versions of SQLite through 3.10.0 and probably beyond,

  58703. ** the locking bytes (WalCkptInfo.aLock) start at offset 120 and

  58704. ** the total header size is 136 bytes.

  58705. **

  58706. ** The szPage value can be any power of 2 between 512 and 32768, inclusive.

  58707. ** Or it can be 1 to represent a 65536-byte page.  The latter case was

  58708. ** added in 3.7.1 when support for 64K pages was added.  

  58709. */

  58710. struct WalIndexHdr {

  58711.   u32 iVersion;                   /* Wal-index version */

  58712.   u32 unused;                     /* Unused (padding) field */

  58713.   u32 iChange;                    /* Counter incremented each transaction */

  58714.   u8 isInit;                      /* 1 when initialized */

  58715.   u8 bigEndCksum;                 /* True if checksums in WAL are big-endian */

  58716.   u16 szPage;                     /* Database page size in bytes. 1==64K */

  58717.   u32 mxFrame;                    /* Index of last valid frame in the WAL */

  58718.   u32 nPage;                      /* Size of database in pages */

  58719.   u32 aFrameCksum[2];             /* Checksum of last frame in log */

  58720.   u32 aSalt[2];                   /* Two salt values copied from WAL header */

  58721.   u32 aCksum[2];                  /* Checksum over all prior fields */

  58722. };

  58723. 

  58724. /*

  58725. ** A copy of the following object occurs in the wal-index immediately

  58726. ** following the second copy of the WalIndexHdr.  This object stores

  58727. ** information used by checkpoint.

  58728. **

  58729. ** nBackfill is the number of frames in the WAL that have been written

  58730. ** back into the database. (We call the act of moving content from WAL to

  58731. ** database "backfilling".)  The nBackfill number is never greater than

  58732. ** WalIndexHdr.mxFrame.  nBackfill can only be increased by threads

  58733. ** holding the WAL_CKPT_LOCK lock (which includes a recovery thread).

  58734. ** However, a WAL_WRITE_LOCK thread can move the value of nBackfill from

  58735. ** mxFrame back to zero when the WAL is reset.

  58736. **

  58737. ** nBackfillAttempted is the largest value of nBackfill that a checkpoint

  58738. ** has attempted to achieve.  Normally nBackfill==nBackfillAtempted, however

  58739. ** the nBackfillAttempted is set before any backfilling is done and the

  58740. ** nBackfill is only set after all backfilling completes.  So if a checkpoint

  58741. ** crashes, nBackfillAttempted might be larger than nBackfill.  The

  58742. ** WalIndexHdr.mxFrame must never be less than nBackfillAttempted.

  58743. **

  58744. ** The aLock[] field is a set of bytes used for locking.  These bytes should

  58745. ** never be read or written.

  58746. **

  58747. ** There is one entry in aReadMark[] for each reader lock.  If a reader

  58748. ** holds read-lock K, then the value in aReadMark[K] is no greater than

  58749. ** the mxFrame for that reader.  The value READMARK_NOT_USED (0xffffffff)

  58750. ** for any aReadMark[] means that entry is unused.  aReadMark[0] is 

  58751. ** a special case; its value is never used and it exists as a place-holder

  58752. ** to avoid having to offset aReadMark[] indexs by one.  Readers holding

  58753. ** WAL_READ_LOCK(0) always ignore the entire WAL and read all content

  58754. ** directly from the database.

  58755. **

  58756. ** The value of aReadMark[K] may only be changed by a thread that

  58757. ** is holding an exclusive lock on WAL_READ_LOCK(K).  Thus, the value of

  58758. ** aReadMark[K] cannot changed while there is a reader is using that mark

  58759. ** since the reader will be holding a shared lock on WAL_READ_LOCK(K).

  58760. **

  58761. ** The checkpointer may only transfer frames from WAL to database where

  58762. ** the frame numbers are less than or equal to every aReadMark[] that is

  58763. ** in use (that is, every aReadMark[j] for which there is a corresponding

  58764. ** WAL_READ_LOCK(j)).  New readers (usually) pick the aReadMark[] with the

  58765. ** largest value and will increase an unused aReadMark[] to mxFrame if there

  58766. ** is not already an aReadMark[] equal to mxFrame.  The exception to the

  58767. ** previous sentence is when nBackfill equals mxFrame (meaning that everything

  58768. ** in the WAL has been backfilled into the database) then new readers

  58769. ** will choose aReadMark[0] which has value 0 and hence such reader will

  58770. ** get all their all content directly from the database file and ignore 

  58771. ** the WAL.

  58772. **

  58773. ** Writers normally append new frames to the end of the WAL.  However,

  58774. ** if nBackfill equals mxFrame (meaning that all WAL content has been

  58775. ** written back into the database) and if no readers are using the WAL

  58776. ** (in other words, if there are no WAL_READ_LOCK(i) where i>0) then

  58777. ** the writer will first "reset" the WAL back to the beginning and start

  58778. ** writing new content beginning at frame 1.

  58779. **

  58780. ** We assume that 32-bit loads are atomic and so no locks are needed in

  58781. ** order to read from any aReadMark[] entries.

  58782. */

  58783. struct WalCkptInfo {

  58784.   u32 nBackfill;                  /* Number of WAL frames backfilled into DB */

  58785.   u32 aReadMark[WAL_NREADER];     /* Reader marks */

  58786.   u8 aLock[SQLITE_SHM_NLOCK];     /* Reserved space for locks */

  58787.   u32 nBackfillAttempted;         /* WAL frames perhaps written, or maybe not */

  58788.   u32 notUsed0;                   /* Available for future enhancements */

  58789. };

  58790. #define READMARK_NOT_USED  0xffffffff

  58791. 

  58792. 

  58793. /* A block of WALINDEX_LOCK_RESERVED bytes beginning at

  58794. ** WALINDEX_LOCK_OFFSET is reserved for locks. Since some systems

  58795. ** only support mandatory file-locks, we do not read or write data

  58796. ** from the region of the file on which locks are applied.

  58797. */

  58798. #define WALINDEX_LOCK_OFFSET (sizeof(WalIndexHdr)*2+offsetof(WalCkptInfo,aLock))

  58799. #define WALINDEX_HDR_SIZE    (sizeof(WalIndexHdr)*2+sizeof(WalCkptInfo))

  58800. 

  58801. /* Size of header before each frame in wal */

  58802. #define WAL_FRAME_HDRSIZE 24

  58803. 

  58804. /* Size of write ahead log header, including checksum. */

  58805. #define WAL_HDRSIZE 32

  58806. 

  58807. /* WAL magic value. Either this value, or the same value with the least

  58808. ** significant bit also set (WAL_MAGIC | 0x00000001) is stored in 32-bit

  58809. ** big-endian format in the first 4 bytes of a WAL file.

  58810. **

  58811. ** If the LSB is set, then the checksums for each frame within the WAL

  58812. ** file are calculated by treating all data as an array of 32-bit 

  58813. ** big-endian words. Otherwise, they are calculated by interpreting 

  58814. ** all data as 32-bit little-endian words.

  58815. */

  58816. #define WAL_MAGIC 0x377f0682

  58817. 

  58818. /*

  58819. ** Return the offset of frame iFrame in the write-ahead log file, 

  58820. ** assuming a database page size of szPage bytes. The offset returned

  58821. ** is to the start of the write-ahead log frame-header.

  58822. */

  58823. #define walFrameOffset(iFrame, szPage) (                               \

  58824.   WAL_HDRSIZE + ((iFrame)-1)*(i64)((szPage)+WAL_FRAME_HDRSIZE)         \

  58825. )

  58826. 

  58827. /*

  58828. ** An open write-ahead log file is represented by an instance of the

  58829. ** following object.

  58830. */

  58831. struct Wal {

  58832.   sqlite3_vfs *pVfs;         /* The VFS used to create pDbFd */

  58833.   sqlite3_file *pDbFd;       /* File handle for the database file */

  58834.   sqlite3_file *pWalFd;      /* File handle for WAL file */

  58835.   u32 iCallback;             /* Value to pass to log callback (or 0) */

  58836.   i64 mxWalSize;             /* Truncate WAL to this size upon reset */

  58837.   int nWiData;               /* Size of array apWiData */

  58838.   int szFirstBlock;          /* Size of first block written to WAL file */

  58839.   volatile u32 **apWiData;   /* Pointer to wal-index content in memory */

  58840.   u32 szPage;                /* Database page size */

  58841.   i16 readLock;              /* Which read lock is being held.  -1 for none */

  58842.   u8 syncFlags;              /* Flags to use to sync header writes */

  58843.   u8 exclusiveMode;          /* Non-zero if connection is in exclusive mode */

  58844.   u8 writeLock;              /* True if in a write transaction */

  58845.   u8 ckptLock;               /* True if holding a checkpoint lock */

  58846.   u8 readOnly;               /* WAL_RDWR, WAL_RDONLY, or WAL_SHM_RDONLY */

  58847.   u8 truncateOnCommit;       /* True to truncate WAL file on commit */

  58848.   u8 syncHeader;             /* Fsync the WAL header if true */

  58849.   u8 padToSectorBoundary;    /* Pad transactions out to the next sector */

  58850.   u8 bShmUnreliable;         /* SHM content is read-only and unreliable */

  58851.   WalIndexHdr hdr;           /* Wal-index header for current transaction */

  58852.   u32 minFrame;              /* Ignore wal frames before this one */

  58853.   u32 iReCksum;              /* On commit, recalculate checksums from here */

  58854.   const char *zWalName;      /* Name of WAL file */

  58855.   u32 nCkpt;                 /* Checkpoint sequence counter in the wal-header */

  58856. #ifdef SQLITE_DEBUG

  58857.   u8 lockError;              /* True if a locking error has occurred */

  58858. #endif

  58859. #ifdef SQLITE_ENABLE_SNAPSHOT

  58860.   WalIndexHdr *pSnapshot;    /* Start transaction here if not NULL */

  58861. #endif

  58862. };

  58863. 

  58864. /*

  58865. ** Candidate values for Wal.exclusiveMode.

  58866. */

  58867. #define WAL_NORMAL_MODE     0

  58868. #define WAL_EXCLUSIVE_MODE  1     

  58869. #define WAL_HEAPMEMORY_MODE 2

  58870. 

  58871. /*

  58872. ** Possible values for WAL.readOnly

  58873. */

  58874. #define WAL_RDWR        0    /* Normal read/write connection */

  58875. #define WAL_RDONLY      1    /* The WAL file is readonly */

  58876. #define WAL_SHM_RDONLY  2    /* The SHM file is readonly */

  58877. 

  58878. /*

  58879. ** Each page of the wal-index mapping contains a hash-table made up of

  58880. ** an array of HASHTABLE_NSLOT elements of the following type.

  58881. */

  58882. typedef u16 ht_slot;

  58883. 

  58884. /*

  58885. ** This structure is used to implement an iterator that loops through

  58886. ** all frames in the WAL in database page order. Where two or more frames

  58887. ** correspond to the same database page, the iterator visits only the 

  58888. ** frame most recently written to the WAL (in other words, the frame with

  58889. ** the largest index).

  58890. **

  58891. ** The internals of this structure are only accessed by:

  58892. **

  58893. **   walIteratorInit() - Create a new iterator,

  58894. **   walIteratorNext() - Step an iterator,

  58895. **   walIteratorFree() - Free an iterator.

  58896. **

  58897. ** This functionality is used by the checkpoint code (see walCheckpoint()).

  58898. */

  58899. struct WalIterator {

  58900.   int iPrior;                     /* Last result returned from the iterator */

  58901.   int nSegment;                   /* Number of entries in aSegment[] */

  58902.   struct WalSegment {

  58903.     int iNext;                    /* Next slot in aIndex[] not yet returned */

  58904.     ht_slot *aIndex;              /* i0, i1, i2... such that aPgno[iN] ascend */

  58905.     u32 *aPgno;                   /* Array of page numbers. */

  58906.     int nEntry;                   /* Nr. of entries in aPgno[] and aIndex[] */

  58907.     int iZero;                    /* Frame number associated with aPgno[0] */

  58908.   } aSegment[1];                  /* One for every 32KB page in the wal-index */

  58909. };

  58910. 

  58911. /*

  58912. ** Define the parameters of the hash tables in the wal-index file. There

  58913. ** is a hash-table following every HASHTABLE_NPAGE page numbers in the

  58914. ** wal-index.

  58915. **

  58916. ** Changing any of these constants will alter the wal-index format and

  58917. ** create incompatibilities.

  58918. */

  58919. #define HASHTABLE_NPAGE      4096                 /* Must be power of 2 */

  58920. #define HASHTABLE_HASH_1     383                  /* Should be prime */

  58921. #define HASHTABLE_NSLOT      (HASHTABLE_NPAGE*2)  /* Must be a power of 2 */

  58922. 

  58923. /* 

  58924. ** The block of page numbers associated with the first hash-table in a

  58925. ** wal-index is smaller than usual. This is so that there is a complete

  58926. ** hash-table on each aligned 32KB page of the wal-index.

  58927. */

  58928. #define HASHTABLE_NPAGE_ONE  (HASHTABLE_NPAGE - (WALINDEX_HDR_SIZE/sizeof(u32)))

  58929. 

  58930. /* The wal-index is divided into pages of WALINDEX_PGSZ bytes each. */

  58931. #define WALINDEX_PGSZ   (                                         \

  58932.     sizeof(ht_slot)*HASHTABLE_NSLOT + HASHTABLE_NPAGE*sizeof(u32) \

  58933. )

  58934. 

  58935. /*

  58936. ** Obtain a pointer to the iPage'th page of the wal-index. The wal-index

  58937. ** is broken into pages of WALINDEX_PGSZ bytes. Wal-index pages are

  58938. ** numbered from zero.

  58939. **

  58940. ** If the wal-index is currently smaller the iPage pages then the size

  58941. ** of the wal-index might be increased, but only if it is safe to do

  58942. ** so.  It is safe to enlarge the wal-index if pWal->writeLock is true

  58943. ** or pWal->exclusiveMode==WAL_HEAPMEMORY_MODE.

  58944. **

  58945. ** If this call is successful, *ppPage is set to point to the wal-index

  58946. ** page and SQLITE_OK is returned. If an error (an OOM or VFS error) occurs,

  58947. ** then an SQLite error code is returned and *ppPage is set to 0.

  58948. */

  58949. static SQLITE_NOINLINE int walIndexPageRealloc(

  58950.   Wal *pWal,               /* The WAL context */

  58951.   int iPage,               /* The page we seek */

  58952.   volatile u32 **ppPage    /* Write the page pointer here */

  58953. ){

  58954.   int rc = SQLITE_OK;

  58955. 

  58956.   /* Enlarge the pWal->apWiData[] array if required */

  58957.   if( pWal->nWiData<=iPage ){

  58958.     sqlite3_int64 nByte = sizeof(u32*)*(iPage+1);

  58959.     volatile u32 **apNew;

  58960.     apNew = (volatile u32 **)sqlite3_realloc64((void *)pWal->apWiData, nByte);

  58961.     if( !apNew ){

  58962.       *ppPage = 0;

  58963.       return SQLITE_NOMEM_BKPT;

  58964.     }

  58965.     memset((void*)&apNew[pWal->nWiData], 0,

  58966.            sizeof(u32*)*(iPage+1-pWal->nWiData));

  58967.     pWal->apWiData = apNew;

  58968.     pWal->nWiData = iPage+1;

  58969.   }

  58970. 

  58971.   /* Request a pointer to the required page from the VFS */

  58972.   assert( pWal->apWiData[iPage]==0 );

  58973.   if( pWal->exclusiveMode==WAL_HEAPMEMORY_MODE ){

  58974.     pWal->apWiData[iPage] = (u32 volatile *)sqlite3MallocZero(WALINDEX_PGSZ);

  58975.     if( !pWal->apWiData[iPage] ) rc = SQLITE_NOMEM_BKPT;

  58976.   }else{

  58977.     rc = sqlite3OsShmMap(pWal->pDbFd, iPage, WALINDEX_PGSZ, 

  58978.         pWal->writeLock, (void volatile **)&pWal->apWiData[iPage]

  58979.     );

  58980.     assert( pWal->apWiData[iPage]!=0 || rc!=SQLITE_OK || pWal->writeLock==0 );

  58981.     testcase( pWal->apWiData[iPage]==0 && rc==SQLITE_OK );

  58982.     if( (rc&0xff)==SQLITE_READONLY ){

  58983.       pWal->readOnly |= WAL_SHM_RDONLY;

  58984.       if( rc==SQLITE_READONLY ){

  58985.         rc = SQLITE_OK;

  58986.       }

  58987.     }

  58988.   }

  58989. 

  58990.   *ppPage = pWal->apWiData[iPage];

  58991.   assert( iPage==0 || *ppPage || rc!=SQLITE_OK );

  58992.   return rc;

  58993. }

  58994. static int walIndexPage(

  58995.   Wal *pWal,               /* The WAL context */

  58996.   int iPage,               /* The page we seek */

  58997.   volatile u32 **ppPage    /* Write the page pointer here */

  58998. ){

  58999.   if( pWal->nWiData<=iPage || (*ppPage = pWal->apWiData[iPage])==0 ){

  59000.     return walIndexPageRealloc(pWal, iPage, ppPage);

  59001.   }

  59002.   return SQLITE_OK;

  59003. }

  59004. 

  59005. /*

  59006. ** Return a pointer to the WalCkptInfo structure in the wal-index.

  59007. */

  59008. static volatile WalCkptInfo *walCkptInfo(Wal *pWal){

  59009.   assert( pWal->nWiData>0 && pWal->apWiData[0] );

  59010.   return (volatile WalCkptInfo*)&(pWal->apWiData[0][sizeof(WalIndexHdr)/2]);

  59011. }

  59012. 

  59013. /*

  59014. ** Return a pointer to the WalIndexHdr structure in the wal-index.

  59015. */

  59016. static volatile WalIndexHdr *walIndexHdr(Wal *pWal){

  59017.   assert( pWal->nWiData>0 && pWal->apWiData[0] );

  59018.   return (volatile WalIndexHdr*)pWal->apWiData[0];

  59019. }

  59020. 

  59021. /*

  59022. ** The argument to this macro must be of type u32. On a little-endian

  59023. ** architecture, it returns the u32 value that results from interpreting

  59024. ** the 4 bytes as a big-endian value. On a big-endian architecture, it

  59025. ** returns the value that would be produced by interpreting the 4 bytes

  59026. ** of the input value as a little-endian integer.

  59027. */

  59028. #define BYTESWAP32(x) ( \

  59029.     (((x)&0x000000FF)<<24) + (((x)&0x0000FF00)<<8)  \

  59030.   + (((x)&0x00FF0000)>>8)  + (((x)&0xFF000000)>>24) \

  59031. )

  59032. 

  59033. /*

  59034. ** Generate or extend an 8 byte checksum based on the data in 

  59035. ** array aByte[] and the initial values of aIn[0] and aIn[1] (or

  59036. ** initial values of 0 and 0 if aIn==NULL).

  59037. **

  59038. ** The checksum is written back into aOut[] before returning.

  59039. **

  59040. ** nByte must be a positive multiple of 8.

  59041. */

  59042. static void walChecksumBytes(

  59043.   int nativeCksum, /* True for native byte-order, false for non-native */

  59044.   u8 *a,           /* Content to be checksummed */

  59045.   int nByte,       /* Bytes of content in a[].  Must be a multiple of 8. */

  59046.   const u32 *aIn,  /* Initial checksum value input */

  59047.   u32 *aOut        /* OUT: Final checksum value output */

  59048. ){

  59049.   u32 s1, s2;

  59050.   u32 *aData = (u32 *)a;

  59051.   u32 *aEnd = (u32 *)&a[nByte];

  59052. 

  59053.   if( aIn ){

  59054.     s1 = aIn[0];

  59055.     s2 = aIn[1];

  59056.   }else{

  59057.     s1 = s2 = 0;

  59058.   }

  59059. 

  59060.   assert( nByte>=8 );

  59061.   assert( (nByte&0x00000007)==0 );

  59062.   assert( nByte<=65536 );

  59063. 

  59064.   if( nativeCksum ){

  59065.     do {

  59066.       s1 += *aData++ + s2;

  59067.       s2 += *aData++ + s1;

  59068.     }while( aData<aEnd );

  59069.   }else{

  59070.     do {

  59071.       s1 += BYTESWAP32(aData[0]) + s2;

  59072.       s2 += BYTESWAP32(aData[1]) + s1;

  59073.       aData += 2;

  59074.     }while( aData<aEnd );

  59075.   }

  59076. 

  59077.   aOut[0] = s1;

  59078.   aOut[1] = s2;

  59079. }

  59080. 

  59081. static void walShmBarrier(Wal *pWal){

  59082.   if( pWal->exclusiveMode!=WAL_HEAPMEMORY_MODE ){

  59083.     sqlite3OsShmBarrier(pWal->pDbFd);

  59084.   }

  59085. }

  59086. 

  59087. /*

  59088. ** Write the header information in pWal->hdr into the wal-index.

  59089. **

  59090. ** The checksum on pWal->hdr is updated before it is written.

  59091. */

  59092. static void walIndexWriteHdr(Wal *pWal){

  59093.   volatile WalIndexHdr *aHdr = walIndexHdr(pWal);

  59094.   const int nCksum = offsetof(WalIndexHdr, aCksum);

  59095. 

  59096.   assert( pWal->writeLock );

  59097.   pWal->hdr.isInit = 1;

  59098.   pWal->hdr.iVersion = WALINDEX_MAX_VERSION;

  59099.   walChecksumBytes(1, (u8*)&pWal->hdr, nCksum, 0, pWal->hdr.aCksum);

  59100.   memcpy((void*)&aHdr[1], (const void*)&pWal->hdr, sizeof(WalIndexHdr));

  59101.   walShmBarrier(pWal);

  59102.   memcpy((void*)&aHdr[0], (const void*)&pWal->hdr, sizeof(WalIndexHdr));

  59103. }

  59104. 

  59105. /*

  59106. ** This function encodes a single frame header and writes it to a buffer

  59107. ** supplied by the caller. A frame-header is made up of a series of 

  59108. ** 4-byte big-endian integers, as follows:

  59109. **

  59110. **     0: Page number.

  59111. **     4: For commit records, the size of the database image in pages 

  59112. **        after the commit. For all other records, zero.

  59113. **     8: Salt-1 (copied from the wal-header)

  59114. **    12: Salt-2 (copied from the wal-header)

  59115. **    16: Checksum-1.

  59116. **    20: Checksum-2.

  59117. */

  59118. static void walEncodeFrame(

  59119.   Wal *pWal,                      /* The write-ahead log */

  59120.   u32 iPage,                      /* Database page number for frame */

  59121.   u32 nTruncate,                  /* New db size (or 0 for non-commit frames) */

  59122.   u8 *aData,                      /* Pointer to page data */

  59123.   u8 *aFrame                      /* OUT: Write encoded frame here */

  59124. ){

  59125.   int nativeCksum;                /* True for native byte-order checksums */

  59126.   u32 *aCksum = pWal->hdr.aFrameCksum;

  59127.   assert( WAL_FRAME_HDRSIZE==24 );

  59128.   sqlite3Put4byte(&aFrame[0], iPage);

  59129.   sqlite3Put4byte(&aFrame[4], nTruncate);

  59130.   if( pWal->iReCksum==0 ){

  59131.     memcpy(&aFrame[8], pWal->hdr.aSalt, 8);

  59132. 

  59133.     nativeCksum = (pWal->hdr.bigEndCksum==SQLITE_BIGENDIAN);

  59134.     walChecksumBytes(nativeCksum, aFrame, 8, aCksum, aCksum);

  59135.     walChecksumBytes(nativeCksum, aData, pWal->szPage, aCksum, aCksum);

  59136. 

  59137.     sqlite3Put4byte(&aFrame[16], aCksum[0]);

  59138.     sqlite3Put4byte(&aFrame[20], aCksum[1]);

  59139.   }else{

  59140.     memset(&aFrame[8], 0, 16);

  59141.   }

  59142. }

  59143. 

  59144. /*

  59145. ** Check to see if the frame with header in aFrame[] and content

  59146. ** in aData[] is valid.  If it is a valid frame, fill *piPage and

  59147. ** *pnTruncate and return true.  Return if the frame is not valid.

  59148. */

  59149. static int walDecodeFrame(

  59150.   Wal *pWal,                      /* The write-ahead log */

  59151.   u32 *piPage,                    /* OUT: Database page number for frame */

  59152.   u32 *pnTruncate,                /* OUT: New db size (or 0 if not commit) */

  59153.   u8 *aData,                      /* Pointer to page data (for checksum) */

  59154.   u8 *aFrame                      /* Frame data */

  59155. ){

  59156.   int nativeCksum;                /* True for native byte-order checksums */

  59157.   u32 *aCksum = pWal->hdr.aFrameCksum;

  59158.   u32 pgno;                       /* Page number of the frame */

  59159.   assert( WAL_FRAME_HDRSIZE==24 );

  59160. 

  59161.   /* A frame is only valid if the salt values in the frame-header

  59162.   ** match the salt values in the wal-header. 

  59163.   */

  59164.   if( memcmp(&pWal->hdr.aSalt, &aFrame[8], 8)!=0 ){

  59165.     return 0;

  59166.   }

  59167. 

  59168.   /* A frame is only valid if the page number is creater than zero.

  59169.   */

  59170.   pgno = sqlite3Get4byte(&aFrame[0]);

  59171.   if( pgno==0 ){

  59172.     return 0;

  59173.   }

  59174. 

  59175.   /* A frame is only valid if a checksum of the WAL header,

  59176.   ** all prior frams, the first 16 bytes of this frame-header, 

  59177.   ** and the frame-data matches the checksum in the last 8 

  59178.   ** bytes of this frame-header.

  59179.   */

  59180.   nativeCksum = (pWal->hdr.bigEndCksum==SQLITE_BIGENDIAN);

  59181.   walChecksumBytes(nativeCksum, aFrame, 8, aCksum, aCksum);

  59182.   walChecksumBytes(nativeCksum, aData, pWal->szPage, aCksum, aCksum);

  59183.   if( aCksum[0]!=sqlite3Get4byte(&aFrame[16]) 

  59184.    || aCksum[1]!=sqlite3Get4byte(&aFrame[20]) 

  59185.   ){

  59186.     /* Checksum failed. */

  59187.     return 0;

  59188.   }

  59189. 

  59190.   /* If we reach this point, the frame is valid.  Return the page number

  59191.   ** and the new database size.

  59192.   */

  59193.   *piPage = pgno;

  59194.   *pnTruncate = sqlite3Get4byte(&aFrame[4]);

  59195.   return 1;

  59196. }

  59197. 

  59198. 

  59199. #if defined(SQLITE_TEST) && defined(SQLITE_DEBUG)

  59200. /*

  59201. ** Names of locks.  This routine is used to provide debugging output and is not

  59202. ** a part of an ordinary build.

  59203. */

  59204. static const char *walLockName(int lockIdx){

  59205.   if( lockIdx==WAL_WRITE_LOCK ){

  59206.     return "WRITE-LOCK";

  59207.   }else if( lockIdx==WAL_CKPT_LOCK ){

  59208.     return "CKPT-LOCK";

  59209.   }else if( lockIdx==WAL_RECOVER_LOCK ){

  59210.     return "RECOVER-LOCK";

  59211.   }else{

  59212.     static char zName[15];

  59213.     sqlite3_snprintf(sizeof(zName), zName, "READ-LOCK[%d]",

  59214.                      lockIdx-WAL_READ_LOCK(0));

  59215.     return zName;

  59216.   }

  59217. }

  59218. #endif /*defined(SQLITE_TEST) || defined(SQLITE_DEBUG) */

  59219.     

  59220. 

  59221. /*

  59222. ** Set or release locks on the WAL.  Locks are either shared or exclusive.

  59223. ** A lock cannot be moved directly between shared and exclusive - it must go

  59224. ** through the unlocked state first.

  59225. **

  59226. ** In locking_mode=EXCLUSIVE, all of these routines become no-ops.

  59227. */

  59228. static int walLockShared(Wal *pWal, int lockIdx){

  59229.   int rc;

  59230.   if( pWal->exclusiveMode ) return SQLITE_OK;

  59231.   rc = sqlite3OsShmLock(pWal->pDbFd, lockIdx, 1,

  59232.                         SQLITE_SHM_LOCK | SQLITE_SHM_SHARED);

  59233.   WALTRACE(("WAL%p: acquire SHARED-%s %s\n", pWal,

  59234.             walLockName(lockIdx), rc ? "failed" : "ok"));

  59235.   VVA_ONLY( pWal->lockError = (u8)(rc!=SQLITE_OK && rc!=SQLITE_BUSY); )

  59236.   return rc;

  59237. }

  59238. static void walUnlockShared(Wal *pWal, int lockIdx){

  59239.   if( pWal->exclusiveMode ) return;

  59240.   (void)sqlite3OsShmLock(pWal->pDbFd, lockIdx, 1,

  59241.                          SQLITE_SHM_UNLOCK | SQLITE_SHM_SHARED);

  59242.   WALTRACE(("WAL%p: release SHARED-%s\n", pWal, walLockName(lockIdx)));

  59243. }

  59244. static int walLockExclusive(Wal *pWal, int lockIdx, int n){

  59245.   int rc;

  59246.   if( pWal->exclusiveMode ) return SQLITE_OK;

  59247.   rc = sqlite3OsShmLock(pWal->pDbFd, lockIdx, n,

  59248.                         SQLITE_SHM_LOCK | SQLITE_SHM_EXCLUSIVE);

  59249.   WALTRACE(("WAL%p: acquire EXCLUSIVE-%s cnt=%d %s\n", pWal,

  59250.             walLockName(lockIdx), n, rc ? "failed" : "ok"));

  59251.   VVA_ONLY( pWal->lockError = (u8)(rc!=SQLITE_OK && rc!=SQLITE_BUSY); )

  59252.   return rc;

  59253. }

  59254. static void walUnlockExclusive(Wal *pWal, int lockIdx, int n){

  59255.   if( pWal->exclusiveMode ) return;

  59256.   (void)sqlite3OsShmLock(pWal->pDbFd, lockIdx, n,

  59257.                          SQLITE_SHM_UNLOCK | SQLITE_SHM_EXCLUSIVE);

  59258.   WALTRACE(("WAL%p: release EXCLUSIVE-%s cnt=%d\n", pWal,

  59259.              walLockName(lockIdx), n));

  59260. }

  59261. 

  59262. /*

  59263. ** Compute a hash on a page number.  The resulting hash value must land

  59264. ** between 0 and (HASHTABLE_NSLOT-1).  The walHashNext() function advances

  59265. ** the hash to the next value in the event of a collision.

  59266. */

  59267. static int walHash(u32 iPage){

  59268.   assert( iPage>0 );

  59269.   assert( (HASHTABLE_NSLOT & (HASHTABLE_NSLOT-1))==0 );

  59270.   return (iPage*HASHTABLE_HASH_1) & (HASHTABLE_NSLOT-1);

  59271. }

  59272. static int walNextHash(int iPriorHash){

  59273.   return (iPriorHash+1)&(HASHTABLE_NSLOT-1);

  59274. }

  59275. 

  59276. /*

  59277. ** An instance of the WalHashLoc object is used to describe the location

  59278. ** of a page hash table in the wal-index.  This becomes the return value

  59279. ** from walHashGet().

  59280. */

  59281. typedef struct WalHashLoc WalHashLoc;

  59282. struct WalHashLoc {

  59283.   volatile ht_slot *aHash;  /* Start of the wal-index hash table */

  59284.   volatile u32 *aPgno;      /* aPgno[1] is the page of first frame indexed */

  59285.   u32 iZero;                /* One less than the frame number of first indexed*/

  59286. };

  59287. 

  59288. /* 

  59289. ** Return pointers to the hash table and page number array stored on

  59290. ** page iHash of the wal-index. The wal-index is broken into 32KB pages

  59291. ** numbered starting from 0.

  59292. **

  59293. ** Set output variable pLoc->aHash to point to the start of the hash table

  59294. ** in the wal-index file. Set pLoc->iZero to one less than the frame 

  59295. ** number of the first frame indexed by this hash table. If a

  59296. ** slot in the hash table is set to N, it refers to frame number 

  59297. ** (pLoc->iZero+N) in the log.

  59298. **

  59299. ** Finally, set pLoc->aPgno so that pLoc->aPgno[1] is the page number of the

  59300. ** first frame indexed by the hash table, frame (pLoc->iZero+1).

  59301. */

  59302. static int walHashGet(

  59303.   Wal *pWal,                      /* WAL handle */

  59304.   int iHash,                      /* Find the iHash'th table */

  59305.   WalHashLoc *pLoc                /* OUT: Hash table location */

  59306. ){

  59307.   int rc;                         /* Return code */

  59308. 

  59309.   rc = walIndexPage(pWal, iHash, &pLoc->aPgno);

  59310.   assert( rc==SQLITE_OK || iHash>0 );

  59311. 

  59312.   if( rc==SQLITE_OK ){

  59313.     pLoc->aHash = (volatile ht_slot *)&pLoc->aPgno[HASHTABLE_NPAGE];

  59314.     if( iHash==0 ){

  59315.       pLoc->aPgno = &pLoc->aPgno[WALINDEX_HDR_SIZE/sizeof(u32)];

  59316.       pLoc->iZero = 0;

  59317.     }else{

  59318.       pLoc->iZero = HASHTABLE_NPAGE_ONE + (iHash-1)*HASHTABLE_NPAGE;

  59319.     }

  59320.     pLoc->aPgno = &pLoc->aPgno[-1];

  59321.   }

  59322.   return rc;

  59323. }

  59324. 

  59325. /*

  59326. ** Return the number of the wal-index page that contains the hash-table

  59327. ** and page-number array that contain entries corresponding to WAL frame

  59328. ** iFrame. The wal-index is broken up into 32KB pages. Wal-index pages 

  59329. ** are numbered starting from 0.

  59330. */

  59331. static int walFramePage(u32 iFrame){

  59332.   int iHash = (iFrame+HASHTABLE_NPAGE-HASHTABLE_NPAGE_ONE-1) / HASHTABLE_NPAGE;

  59333.   assert( (iHash==0 || iFrame>HASHTABLE_NPAGE_ONE)

  59334.        && (iHash>=1 || iFrame<=HASHTABLE_NPAGE_ONE)

  59335.        && (iHash<=1 || iFrame>(HASHTABLE_NPAGE_ONE+HASHTABLE_NPAGE))

  59336.        && (iHash>=2 || iFrame<=HASHTABLE_NPAGE_ONE+HASHTABLE_NPAGE)

  59337.        && (iHash<=2 || iFrame>(HASHTABLE_NPAGE_ONE+2*HASHTABLE_NPAGE))

  59338.   );

  59339.   return iHash;

  59340. }

  59341. 

  59342. /*

  59343. ** Return the page number associated with frame iFrame in this WAL.

  59344. */

  59345. static u32 walFramePgno(Wal *pWal, u32 iFrame){

  59346.   int iHash = walFramePage(iFrame);

  59347.   if( iHash==0 ){

  59348.     return pWal->apWiData[0][WALINDEX_HDR_SIZE/sizeof(u32) + iFrame - 1];

  59349.   }

  59350.   return pWal->apWiData[iHash][(iFrame-1-HASHTABLE_NPAGE_ONE)%HASHTABLE_NPAGE];

  59351. }

  59352. 

  59353. /*

  59354. ** Remove entries from the hash table that point to WAL slots greater

  59355. ** than pWal->hdr.mxFrame.

  59356. **

  59357. ** This function is called whenever pWal->hdr.mxFrame is decreased due

  59358. ** to a rollback or savepoint.

  59359. **

  59360. ** At most only the hash table containing pWal->hdr.mxFrame needs to be

  59361. ** updated.  Any later hash tables will be automatically cleared when

  59362. ** pWal->hdr.mxFrame advances to the point where those hash tables are

  59363. ** actually needed.

  59364. */

  59365. static void walCleanupHash(Wal *pWal){

  59366.   WalHashLoc sLoc;                /* Hash table location */

  59367.   int iLimit = 0;                 /* Zero values greater than this */

  59368.   int nByte;                      /* Number of bytes to zero in aPgno[] */

  59369.   int i;                          /* Used to iterate through aHash[] */

  59370.   int rc;                         /* Return code form walHashGet() */

  59371. 

  59372.   assert( pWal->writeLock );

  59373.   testcase( pWal->hdr.mxFrame==HASHTABLE_NPAGE_ONE-1 );

  59374.   testcase( pWal->hdr.mxFrame==HASHTABLE_NPAGE_ONE );

  59375.   testcase( pWal->hdr.mxFrame==HASHTABLE_NPAGE_ONE+1 );

  59376. 

  59377.   if( pWal->hdr.mxFrame==0 ) return;

  59378. 

  59379.   /* Obtain pointers to the hash-table and page-number array containing 

  59380.   ** the entry that corresponds to frame pWal->hdr.mxFrame. It is guaranteed

  59381.   ** that the page said hash-table and array reside on is already mapped.(1)

  59382.   */

  59383.   assert( pWal->nWiData>walFramePage(pWal->hdr.mxFrame) );

  59384.   assert( pWal->apWiData[walFramePage(pWal->hdr.mxFrame)] );

  59385.   rc = walHashGet(pWal, walFramePage(pWal->hdr.mxFrame), &sLoc);

  59386.   if( NEVER(rc) ) return; /* Defense-in-depth, in case (1) above is wrong */

  59387. 

  59388.   /* Zero all hash-table entries that correspond to frame numbers greater

  59389.   ** than pWal->hdr.mxFrame.

  59390.   */

  59391.   iLimit = pWal->hdr.mxFrame - sLoc.iZero;

  59392.   assert( iLimit>0 );

  59393.   for(i=0; i<HASHTABLE_NSLOT; i++){

  59394.     if( sLoc.aHash[i]>iLimit ){

  59395.       sLoc.aHash[i] = 0;

  59396.     }

  59397.   }

  59398.   

  59399.   /* Zero the entries in the aPgno array that correspond to frames with

  59400.   ** frame numbers greater than pWal->hdr.mxFrame. 

  59401.   */

  59402.   nByte = (int)((char *)sLoc.aHash - (char *)&sLoc.aPgno[iLimit+1]);

  59403.   memset((void *)&sLoc.aPgno[iLimit+1], 0, nByte);

  59404. 

  59405. #ifdef SQLITE_ENABLE_EXPENSIVE_ASSERT

  59406.   /* Verify that the every entry in the mapping region is still reachable

  59407.   ** via the hash table even after the cleanup.

  59408.   */

  59409.   if( iLimit ){

  59410.     int j;           /* Loop counter */

  59411.     int iKey;        /* Hash key */

  59412.     for(j=1; j<=iLimit; j++){

  59413.       for(iKey=walHash(sLoc.aPgno[j]);sLoc.aHash[iKey];iKey=walNextHash(iKey)){

  59414.         if( sLoc.aHash[iKey]==j ) break;

  59415.       }

  59416.       assert( sLoc.aHash[iKey]==j );

  59417.     }

  59418.   }

  59419. #endif /* SQLITE_ENABLE_EXPENSIVE_ASSERT */

  59420. }

  59421. 

  59422. 

  59423. /*

  59424. ** Set an entry in the wal-index that will map database page number

  59425. ** pPage into WAL frame iFrame.

  59426. */

  59427. static int walIndexAppend(Wal *pWal, u32 iFrame, u32 iPage){

  59428.   int rc;                         /* Return code */

  59429.   WalHashLoc sLoc;                /* Wal-index hash table location */

  59430. 

  59431.   rc = walHashGet(pWal, walFramePage(iFrame), &sLoc);

  59432. 

  59433.   /* Assuming the wal-index file was successfully mapped, populate the

  59434.   ** page number array and hash table entry.

  59435.   */

  59436.   if( rc==SQLITE_OK ){

  59437.     int iKey;                     /* Hash table key */

  59438.     int idx;                      /* Value to write to hash-table slot */

  59439.     int nCollide;                 /* Number of hash collisions */

  59440. 

  59441.     idx = iFrame - sLoc.iZero;

  59442.     assert( idx <= HASHTABLE_NSLOT/2 + 1 );

  59443.     

  59444.     /* If this is the first entry to be added to this hash-table, zero the

  59445.     ** entire hash table and aPgno[] array before proceeding. 

  59446.     */

  59447.     if( idx==1 ){

  59448.       int nByte = (int)((u8 *)&sLoc.aHash[HASHTABLE_NSLOT]

  59449.                                - (u8 *)&sLoc.aPgno[1]);

  59450.       memset((void*)&sLoc.aPgno[1], 0, nByte);

  59451.     }

  59452. 

  59453.     /* If the entry in aPgno[] is already set, then the previous writer

  59454.     ** must have exited unexpectedly in the middle of a transaction (after

  59455.     ** writing one or more dirty pages to the WAL to free up memory). 

  59456.     ** Remove the remnants of that writers uncommitted transaction from 

  59457.     ** the hash-table before writing any new entries.

  59458.     */

  59459.     if( sLoc.aPgno[idx] ){

  59460.       walCleanupHash(pWal);

  59461.       assert( !sLoc.aPgno[idx] );

  59462.     }

  59463. 

  59464.     /* Write the aPgno[] array entry and the hash-table slot. */

  59465.     nCollide = idx;

  59466.     for(iKey=walHash(iPage); sLoc.aHash[iKey]; iKey=walNextHash(iKey)){

  59467.       if( (nCollide--)==0 ) return SQLITE_CORRUPT_BKPT;

  59468.     }

  59469.     sLoc.aPgno[idx] = iPage;

  59470.     sLoc.aHash[iKey] = (ht_slot)idx;

  59471. 

  59472. #ifdef SQLITE_ENABLE_EXPENSIVE_ASSERT

  59473.     /* Verify that the number of entries in the hash table exactly equals

  59474.     ** the number of entries in the mapping region.

  59475.     */

  59476.     {

  59477.       int i;           /* Loop counter */

  59478.       int nEntry = 0;  /* Number of entries in the hash table */

  59479.       for(i=0; i<HASHTABLE_NSLOT; i++){ if( sLoc.aHash[i] ) nEntry++; }

  59480.       assert( nEntry==idx );

  59481.     }

  59482. 

  59483.     /* Verify that the every entry in the mapping region is reachable

  59484.     ** via the hash table.  This turns out to be a really, really expensive

  59485.     ** thing to check, so only do this occasionally - not on every

  59486.     ** iteration.

  59487.     */

  59488.     if( (idx&0x3ff)==0 ){

  59489.       int i;           /* Loop counter */

  59490.       for(i=1; i<=idx; i++){

  59491.         for(iKey=walHash(sLoc.aPgno[i]);

  59492.             sLoc.aHash[iKey];

  59493.             iKey=walNextHash(iKey)){

  59494.           if( sLoc.aHash[iKey]==i ) break;

  59495.         }

  59496.         assert( sLoc.aHash[iKey]==i );

  59497.       }

  59498.     }

  59499. #endif /* SQLITE_ENABLE_EXPENSIVE_ASSERT */

  59500.   }

  59501. 

  59502. 

  59503.   return rc;

  59504. }

  59505. 

  59506. 

  59507. /*

  59508. ** Recover the wal-index by reading the write-ahead log file. 

  59509. **

  59510. ** This routine first tries to establish an exclusive lock on the

  59511. ** wal-index to prevent other threads/processes from doing anything

  59512. ** with the WAL or wal-index while recovery is running.  The

  59513. ** WAL_RECOVER_LOCK is also held so that other threads will know

  59514. ** that this thread is running recovery.  If unable to establish

  59515. ** the necessary locks, this routine returns SQLITE_BUSY.

  59516. */

  59517. static int walIndexRecover(Wal *pWal){

  59518.   int rc;                         /* Return Code */

  59519.   i64 nSize;                      /* Size of log file */

  59520.   u32 aFrameCksum[2] = {0, 0};

  59521.   int iLock;                      /* Lock offset to lock for checkpoint */

  59522. 

  59523.   /* Obtain an exclusive lock on all byte in the locking range not already

  59524.   ** locked by the caller. The caller is guaranteed to have locked the

  59525.   ** WAL_WRITE_LOCK byte, and may have also locked the WAL_CKPT_LOCK byte.

  59526.   ** If successful, the same bytes that are locked here are unlocked before

  59527.   ** this function returns.

  59528.   */

  59529.   assert( pWal->ckptLock==1 || pWal->ckptLock==0 );

  59530.   assert( WAL_ALL_BUT_WRITE==WAL_WRITE_LOCK+1 );

  59531.   assert( WAL_CKPT_LOCK==WAL_ALL_BUT_WRITE );

  59532.   assert( pWal->writeLock );

  59533.   iLock = WAL_ALL_BUT_WRITE + pWal->ckptLock;

  59534.   rc = walLockExclusive(pWal, iLock, WAL_READ_LOCK(0)-iLock);

  59535.   if( rc==SQLITE_OK ){

  59536.     rc = walLockExclusive(pWal, WAL_READ_LOCK(1), WAL_NREADER-1);

  59537.     if( rc!=SQLITE_OK ){

  59538.       walUnlockExclusive(pWal, iLock, WAL_READ_LOCK(0)-iLock);

  59539.     }

  59540.   }

  59541.   if( rc ){

  59542.     return rc;

  59543.   }

  59544. 

  59545.   WALTRACE(("WAL%p: recovery begin...\n", pWal));

  59546. 

  59547.   memset(&pWal->hdr, 0, sizeof(WalIndexHdr));

  59548. 

  59549.   rc = sqlite3OsFileSize(pWal->pWalFd, &nSize);

  59550.   if( rc!=SQLITE_OK ){

  59551.     goto recovery_error;

  59552.   }

  59553. 

  59554.   if( nSize>WAL_HDRSIZE ){

  59555.     u8 aBuf[WAL_HDRSIZE];         /* Buffer to load WAL header into */

  59556.     u8 *aFrame = 0;               /* Malloc'd buffer to load entire frame */

  59557.     int szFrame;                  /* Number of bytes in buffer aFrame[] */

  59558.     u8 *aData;                    /* Pointer to data part of aFrame buffer */

  59559.     int iFrame;                   /* Index of last frame read */

  59560.     i64 iOffset;                  /* Next offset to read from log file */

  59561.     int szPage;                   /* Page size according to the log */

  59562.     u32 magic;                    /* Magic value read from WAL header */

  59563.     u32 version;                  /* Magic value read from WAL header */

  59564.     int isValid;                  /* True if this frame is valid */

  59565. 

  59566.     /* Read in the WAL header. */

  59567.     rc = sqlite3OsRead(pWal->pWalFd, aBuf, WAL_HDRSIZE, 0);

  59568.     if( rc!=SQLITE_OK ){

  59569.       goto recovery_error;

  59570.     }

  59571. 

  59572.     /* If the database page size is not a power of two, or is greater than

  59573.     ** SQLITE_MAX_PAGE_SIZE, conclude that the WAL file contains no valid 

  59574.     ** data. Similarly, if the 'magic' value is invalid, ignore the whole

  59575.     ** WAL file.

  59576.     */

  59577.     magic = sqlite3Get4byte(&aBuf[0]);

  59578.     szPage = sqlite3Get4byte(&aBuf[8]);

  59579.     if( (magic&0xFFFFFFFE)!=WAL_MAGIC 

  59580.      || szPage&(szPage-1) 

  59581.      || szPage>SQLITE_MAX_PAGE_SIZE 

  59582.      || szPage<512 

  59583.     ){

  59584.       goto finished;

  59585.     }

  59586.     pWal->hdr.bigEndCksum = (u8)(magic&0x00000001);

  59587.     pWal->szPage = szPage;

  59588.     pWal->nCkpt = sqlite3Get4byte(&aBuf[12]);

  59589.     memcpy(&pWal->hdr.aSalt, &aBuf[16], 8);

  59590. 

  59591.     /* Verify that the WAL header checksum is correct */

  59592.     walChecksumBytes(pWal->hdr.bigEndCksum==SQLITE_BIGENDIAN, 

  59593.         aBuf, WAL_HDRSIZE-2*4, 0, pWal->hdr.aFrameCksum

  59594.     );

  59595.     if( pWal->hdr.aFrameCksum[0]!=sqlite3Get4byte(&aBuf[24])

  59596.      || pWal->hdr.aFrameCksum[1]!=sqlite3Get4byte(&aBuf[28])

  59597.     ){

  59598.       goto finished;

  59599.     }

  59600. 

  59601.     /* Verify that the version number on the WAL format is one that

  59602.     ** are able to understand */

  59603.     version = sqlite3Get4byte(&aBuf[4]);

  59604.     if( version!=WAL_MAX_VERSION ){

  59605.       rc = SQLITE_CANTOPEN_BKPT;

  59606.       goto finished;

  59607.     }

  59608. 

  59609.     /* Malloc a buffer to read frames into. */

  59610.     szFrame = szPage + WAL_FRAME_HDRSIZE;

  59611.     aFrame = (u8 *)sqlite3_malloc64(szFrame);

  59612.     if( !aFrame ){

  59613.       rc = SQLITE_NOMEM_BKPT;

  59614.       goto recovery_error;

  59615.     }

  59616.     aData = &aFrame[WAL_FRAME_HDRSIZE];

  59617. 

  59618.     /* Read all frames from the log file. */

  59619.     iFrame = 0;

  59620.     for(iOffset=WAL_HDRSIZE; (iOffset+szFrame)<=nSize; iOffset+=szFrame){

  59621.       u32 pgno;                   /* Database page number for frame */

  59622.       u32 nTruncate;              /* dbsize field from frame header */

  59623. 

  59624.       /* Read and decode the next log frame. */

  59625.       iFrame++;

  59626.       rc = sqlite3OsRead(pWal->pWalFd, aFrame, szFrame, iOffset);

  59627.       if( rc!=SQLITE_OK ) break;

  59628.       isValid = walDecodeFrame(pWal, &pgno, &nTruncate, aData, aFrame);

  59629.       if( !isValid ) break;

  59630.       rc = walIndexAppend(pWal, iFrame, pgno);

  59631.       if( rc!=SQLITE_OK ) break;

  59632. 

  59633.       /* If nTruncate is non-zero, this is a commit record. */

  59634.       if( nTruncate ){

  59635.         pWal->hdr.mxFrame = iFrame;

  59636.         pWal->hdr.nPage = nTruncate;

  59637.         pWal->hdr.szPage = (u16)((szPage&0xff00) | (szPage>>16));

  59638.         testcase( szPage<=32768 );

  59639.         testcase( szPage>=65536 );

  59640.         aFrameCksum[0] = pWal->hdr.aFrameCksum[0];

  59641.         aFrameCksum[1] = pWal->hdr.aFrameCksum[1];

  59642.       }

  59643.     }

  59644. 

  59645.     sqlite3_free(aFrame);

  59646.   }

  59647. 

  59648. finished:

  59649.   if( rc==SQLITE_OK ){

  59650.     volatile WalCkptInfo *pInfo;

  59651.     int i;

  59652.     pWal->hdr.aFrameCksum[0] = aFrameCksum[0];

  59653.     pWal->hdr.aFrameCksum[1] = aFrameCksum[1];

  59654.     walIndexWriteHdr(pWal);

  59655. 

  59656.     /* Reset the checkpoint-header. This is safe because this thread is 

  59657.     ** currently holding locks that exclude all other readers, writers and

  59658.     ** checkpointers.

  59659.     */

  59660.     pInfo = walCkptInfo(pWal);

  59661.     pInfo->nBackfill = 0;

  59662.     pInfo->nBackfillAttempted = pWal->hdr.mxFrame;

  59663.     pInfo->aReadMark[0] = 0;

  59664.     for(i=1; i<WAL_NREADER; i++) pInfo->aReadMark[i] = READMARK_NOT_USED;

  59665.     if( pWal->hdr.mxFrame ) pInfo->aReadMark[1] = pWal->hdr.mxFrame;

  59666. 

  59667.     /* If more than one frame was recovered from the log file, report an

  59668.     ** event via sqlite3_log(). This is to help with identifying performance

  59669.     ** problems caused by applications routinely shutting down without

  59670.     ** checkpointing the log file.

  59671.     */

  59672.     if( pWal->hdr.nPage ){

  59673.       sqlite3_log(SQLITE_NOTICE_RECOVER_WAL,

  59674.           "recovered %d frames from WAL file %s",

  59675.           pWal->hdr.mxFrame, pWal->zWalName

  59676.       );

  59677.     }

  59678.   }

  59679. 

  59680. recovery_error:

  59681.   WALTRACE(("WAL%p: recovery %s\n", pWal, rc ? "failed" : "ok"));

  59682.   walUnlockExclusive(pWal, iLock, WAL_READ_LOCK(0)-iLock);

  59683.   walUnlockExclusive(pWal, WAL_READ_LOCK(1), WAL_NREADER-1);

  59684.   return rc;

  59685. }

  59686. 

  59687. /*

  59688. ** Close an open wal-index.

  59689. */

  59690. static void walIndexClose(Wal *pWal, int isDelete){

  59691.   if( pWal->exclusiveMode==WAL_HEAPMEMORY_MODE || pWal->bShmUnreliable ){

  59692.     int i;

  59693.     for(i=0; i<pWal->nWiData; i++){

  59694.       sqlite3_free((void *)pWal->apWiData[i]);

  59695.       pWal->apWiData[i] = 0;

  59696.     }

  59697.   }

  59698.   if( pWal->exclusiveMode!=WAL_HEAPMEMORY_MODE ){

  59699.     sqlite3OsShmUnmap(pWal->pDbFd, isDelete);

  59700.   }

  59701. }

  59702. 

  59703. /* 

  59704. ** Open a connection to the WAL file zWalName. The database file must 

  59705. ** already be opened on connection pDbFd. The buffer that zWalName points

  59706. ** to must remain valid for the lifetime of the returned Wal* handle.

  59707. **

  59708. ** A SHARED lock should be held on the database file when this function

  59709. ** is called. The purpose of this SHARED lock is to prevent any other

  59710. ** client from unlinking the WAL or wal-index file. If another process

  59711. ** were to do this just after this client opened one of these files, the

  59712. ** system would be badly broken.

  59713. **

  59714. ** If the log file is successfully opened, SQLITE_OK is returned and 

  59715. ** *ppWal is set to point to a new WAL handle. If an error occurs,

  59716. ** an SQLite error code is returned and *ppWal is left unmodified.

  59717. */

  59718. SQLITE_PRIVATE int sqlite3WalOpen(

  59719.   sqlite3_vfs *pVfs,              /* vfs module to open wal and wal-index */

  59720.   sqlite3_file *pDbFd,            /* The open database file */

  59721.   const char *zWalName,           /* Name of the WAL file */

  59722.   int bNoShm,                     /* True to run in heap-memory mode */

  59723.   i64 mxWalSize,                  /* Truncate WAL to this size on reset */

  59724.   Wal **ppWal                     /* OUT: Allocated Wal handle */

  59725. ){

  59726.   int rc;                         /* Return Code */

  59727.   Wal *pRet;                      /* Object to allocate and return */

  59728.   int flags;                      /* Flags passed to OsOpen() */

  59729. 

  59730.   assert( zWalName && zWalName[0] );

  59731.   assert( pDbFd );

  59732. 

  59733.   /* In the amalgamation, the os_unix.c and os_win.c source files come before

  59734.   ** this source file.  Verify that the #defines of the locking byte offsets

  59735.   ** in os_unix.c and os_win.c agree with the WALINDEX_LOCK_OFFSET value.

  59736.   ** For that matter, if the lock offset ever changes from its initial design

  59737.   ** value of 120, we need to know that so there is an assert() to check it.

  59738.   */

  59739.   assert( 120==WALINDEX_LOCK_OFFSET );

  59740.   assert( 136==WALINDEX_HDR_SIZE );

  59741. #ifdef WIN_SHM_BASE

  59742.   assert( WIN_SHM_BASE==WALINDEX_LOCK_OFFSET );

  59743. #endif

  59744. #ifdef UNIX_SHM_BASE

  59745.   assert( UNIX_SHM_BASE==WALINDEX_LOCK_OFFSET );

  59746. #endif

  59747. 

  59748. 

  59749.   /* Allocate an instance of struct Wal to return. */

  59750.   *ppWal = 0;

  59751.   pRet = (Wal*)sqlite3MallocZero(sizeof(Wal) + pVfs->szOsFile);

  59752.   if( !pRet ){

  59753.     return SQLITE_NOMEM_BKPT;

  59754.   }

  59755. 

  59756.   pRet->pVfs = pVfs;

  59757.   pRet->pWalFd = (sqlite3_file *)&pRet[1];

  59758.   pRet->pDbFd = pDbFd;

  59759.   pRet->readLock = -1;

  59760.   pRet->mxWalSize = mxWalSize;

  59761.   pRet->zWalName = zWalName;

  59762.   pRet->syncHeader = 1;

  59763.   pRet->padToSectorBoundary = 1;

  59764.   pRet->exclusiveMode = (bNoShm ? WAL_HEAPMEMORY_MODE: WAL_NORMAL_MODE);

  59765. 

  59766.   /* Open file handle on the write-ahead log file. */

  59767.   flags = (SQLITE_OPEN_READWRITE|SQLITE_OPEN_CREATE|SQLITE_OPEN_WAL);

  59768.   rc = sqlite3OsOpen(pVfs, zWalName, pRet->pWalFd, flags, &flags);

  59769.   if( rc==SQLITE_OK && flags&SQLITE_OPEN_READONLY ){

  59770.     pRet->readOnly = WAL_RDONLY;

  59771.   }

  59772. 

  59773.   if( rc!=SQLITE_OK ){

  59774.     walIndexClose(pRet, 0);

  59775.     sqlite3OsClose(pRet->pWalFd);

  59776.     sqlite3_free(pRet);

  59777.   }else{

  59778.     int iDC = sqlite3OsDeviceCharacteristics(pDbFd);

  59779.     if( iDC & SQLITE_IOCAP_SEQUENTIAL ){ pRet->syncHeader = 0; }

  59780.     if( iDC & SQLITE_IOCAP_POWERSAFE_OVERWRITE ){

  59781.       pRet->padToSectorBoundary = 0;

  59782.     }

  59783.     *ppWal = pRet;

  59784.     WALTRACE(("WAL%d: opened\n", pRet));

  59785.   }

  59786.   return rc;

  59787. }

  59788. 

  59789. /*

  59790. ** Change the size to which the WAL file is trucated on each reset.

  59791. */

  59792. SQLITE_PRIVATE void sqlite3WalLimit(Wal *pWal, i64 iLimit){

  59793.   if( pWal ) pWal->mxWalSize = iLimit;

  59794. }

  59795. 

  59796. /*

  59797. ** Find the smallest page number out of all pages held in the WAL that

  59798. ** has not been returned by any prior invocation of this method on the

  59799. ** same WalIterator object.   Write into *piFrame the frame index where

  59800. ** that page was last written into the WAL.  Write into *piPage the page

  59801. ** number.

  59802. **

  59803. ** Return 0 on success.  If there are no pages in the WAL with a page

  59804. ** number larger than *piPage, then return 1.

  59805. */

  59806. static int walIteratorNext(

  59807.   WalIterator *p,               /* Iterator */

  59808.   u32 *piPage,                  /* OUT: The page number of the next page */

  59809.   u32 *piFrame                  /* OUT: Wal frame index of next page */

  59810. ){

  59811.   u32 iMin;                     /* Result pgno must be greater than iMin */

  59812.   u32 iRet = 0xFFFFFFFF;        /* 0xffffffff is never a valid page number */

  59813.   int i;                        /* For looping through segments */

  59814. 

  59815.   iMin = p->iPrior;

  59816.   assert( iMin<0xffffffff );

  59817.   for(i=p->nSegment-1; i>=0; i--){

  59818.     struct WalSegment *pSegment = &p->aSegment[i];

  59819.     while( pSegment->iNext<pSegment->nEntry ){

  59820.       u32 iPg = pSegment->aPgno[pSegment->aIndex[pSegment->iNext]];

  59821.       if( iPg>iMin ){

  59822.         if( iPg<iRet ){

  59823.           iRet = iPg;

  59824.           *piFrame = pSegment->iZero + pSegment->aIndex[pSegment->iNext];

  59825.         }

  59826.         break;

  59827.       }

  59828.       pSegment->iNext++;

  59829.     }

  59830.   }

  59831. 

  59832.   *piPage = p->iPrior = iRet;

  59833.   return (iRet==0xFFFFFFFF);

  59834. }

  59835. 

  59836. /*

  59837. ** This function merges two sorted lists into a single sorted list.

  59838. **

  59839. ** aLeft[] and aRight[] are arrays of indices.  The sort key is

  59840. ** aContent[aLeft[]] and aContent[aRight[]].  Upon entry, the following

  59841. ** is guaranteed for all J<K:

  59842. **

  59843. **        aContent[aLeft[J]] < aContent[aLeft[K]]

  59844. **        aContent[aRight[J]] < aContent[aRight[K]]

  59845. **

  59846. ** This routine overwrites aRight[] with a new (probably longer) sequence

  59847. ** of indices such that the aRight[] contains every index that appears in

  59848. ** either aLeft[] or the old aRight[] and such that the second condition

  59849. ** above is still met.

  59850. **

  59851. ** The aContent[aLeft[X]] values will be unique for all X.  And the

  59852. ** aContent[aRight[X]] values will be unique too.  But there might be

  59853. ** one or more combinations of X and Y such that

  59854. **

  59855. **      aLeft[X]!=aRight[Y]  &&  aContent[aLeft[X]] == aContent[aRight[Y]]

  59856. **

  59857. ** When that happens, omit the aLeft[X] and use the aRight[Y] index.

  59858. */

  59859. static void walMerge(

  59860.   const u32 *aContent,            /* Pages in wal - keys for the sort */

  59861.   ht_slot *aLeft,                 /* IN: Left hand input list */

  59862.   int nLeft,                      /* IN: Elements in array *paLeft */

  59863.   ht_slot **paRight,              /* IN/OUT: Right hand input list */

  59864.   int *pnRight,                   /* IN/OUT: Elements in *paRight */

  59865.   ht_slot *aTmp                   /* Temporary buffer */

  59866. ){

  59867.   int iLeft = 0;                  /* Current index in aLeft */

  59868.   int iRight = 0;                 /* Current index in aRight */

  59869.   int iOut = 0;                   /* Current index in output buffer */

  59870.   int nRight = *pnRight;

  59871.   ht_slot *aRight = *paRight;

  59872. 

  59873.   assert( nLeft>0 && nRight>0 );

  59874.   while( iRight<nRight || iLeft<nLeft ){

  59875.     ht_slot logpage;

  59876.     Pgno dbpage;

  59877. 

  59878.     if( (iLeft<nLeft) 

  59879.      && (iRight>=nRight || aContent[aLeft[iLeft]]<aContent[aRight[iRight]])

  59880.     ){

  59881.       logpage = aLeft[iLeft++];

  59882.     }else{

  59883.       logpage = aRight[iRight++];

  59884.     }

  59885.     dbpage = aContent[logpage];

  59886. 

  59887.     aTmp[iOut++] = logpage;

  59888.     if( iLeft<nLeft && aContent[aLeft[iLeft]]==dbpage ) iLeft++;

  59889. 

  59890.     assert( iLeft>=nLeft || aContent[aLeft[iLeft]]>dbpage );

  59891.     assert( iRight>=nRight || aContent[aRight[iRight]]>dbpage );

  59892.   }

  59893. 

  59894.   *paRight = aLeft;

  59895.   *pnRight = iOut;

  59896.   memcpy(aLeft, aTmp, sizeof(aTmp[0])*iOut);

  59897. }

  59898. 

  59899. /*

  59900. ** Sort the elements in list aList using aContent[] as the sort key.

  59901. ** Remove elements with duplicate keys, preferring to keep the

  59902. ** larger aList[] values.

  59903. **

  59904. ** The aList[] entries are indices into aContent[].  The values in

  59905. ** aList[] are to be sorted so that for all J<K:

  59906. **

  59907. **      aContent[aList[J]] < aContent[aList[K]]

  59908. **

  59909. ** For any X and Y such that

  59910. **

  59911. **      aContent[aList[X]] == aContent[aList[Y]]

  59912. **

  59913. ** Keep the larger of the two values aList[X] and aList[Y] and discard

  59914. ** the smaller.

  59915. */

  59916. static void walMergesort(

  59917.   const u32 *aContent,            /* Pages in wal */

  59918.   ht_slot *aBuffer,               /* Buffer of at least *pnList items to use */

  59919.   ht_slot *aList,                 /* IN/OUT: List to sort */

  59920.   int *pnList                     /* IN/OUT: Number of elements in aList[] */

  59921. ){

  59922.   struct Sublist {

  59923.     int nList;                    /* Number of elements in aList */

  59924.     ht_slot *aList;               /* Pointer to sub-list content */

  59925.   };

  59926. 

  59927.   const int nList = *pnList;      /* Size of input list */

  59928.   int nMerge = 0;                 /* Number of elements in list aMerge */

  59929.   ht_slot *aMerge = 0;            /* List to be merged */

  59930.   int iList;                      /* Index into input list */

  59931.   u32 iSub = 0;                   /* Index into aSub array */

  59932.   struct Sublist aSub[13];        /* Array of sub-lists */

  59933. 

  59934.   memset(aSub, 0, sizeof(aSub));

  59935.   assert( nList<=HASHTABLE_NPAGE && nList>0 );

  59936.   assert( HASHTABLE_NPAGE==(1<<(ArraySize(aSub)-1)) );

  59937. 

  59938.   for(iList=0; iList<nList; iList++){

  59939.     nMerge = 1;

  59940.     aMerge = &aList[iList];

  59941.     for(iSub=0; iList & (1<<iSub); iSub++){

  59942.       struct Sublist *p;

  59943.       assert( iSub<ArraySize(aSub) );

  59944.       p = &aSub[iSub];

  59945.       assert( p->aList && p->nList<=(1<<iSub) );

  59946.       assert( p->aList==&aList[iList&~((2<<iSub)-1)] );

  59947.       walMerge(aContent, p->aList, p->nList, &aMerge, &nMerge, aBuffer);

  59948.     }

  59949.     aSub[iSub].aList = aMerge;

  59950.     aSub[iSub].nList = nMerge;

  59951.   }

  59952. 

  59953.   for(iSub++; iSub<ArraySize(aSub); iSub++){

  59954.     if( nList & (1<<iSub) ){

  59955.       struct Sublist *p;

  59956.       assert( iSub<ArraySize(aSub) );

  59957.       p = &aSub[iSub];

  59958.       assert( p->nList<=(1<<iSub) );

  59959.       assert( p->aList==&aList[nList&~((2<<iSub)-1)] );

  59960.       walMerge(aContent, p->aList, p->nList, &aMerge, &nMerge, aBuffer);

  59961.     }

  59962.   }

  59963.   assert( aMerge==aList );

  59964.   *pnList = nMerge;

  59965. 

  59966. #ifdef SQLITE_DEBUG

  59967.   {

  59968.     int i;

  59969.     for(i=1; i<*pnList; i++){

  59970.       assert( aContent[aList[i]] > aContent[aList[i-1]] );

  59971.     }

  59972.   }

  59973. #endif

  59974. }

  59975. 

  59976. /* 

  59977. ** Free an iterator allocated by walIteratorInit().

  59978. */

  59979. static void walIteratorFree(WalIterator *p){

  59980.   sqlite3_free(p);

  59981. }

  59982. 

  59983. /*

  59984. ** Construct a WalInterator object that can be used to loop over all 

  59985. ** pages in the WAL following frame nBackfill in ascending order. Frames

  59986. ** nBackfill or earlier may be included - excluding them is an optimization

  59987. ** only. The caller must hold the checkpoint lock.

  59988. **

  59989. ** On success, make *pp point to the newly allocated WalInterator object

  59990. ** return SQLITE_OK. Otherwise, return an error code. If this routine

  59991. ** returns an error, the value of *pp is undefined.

  59992. **

  59993. ** The calling routine should invoke walIteratorFree() to destroy the

  59994. ** WalIterator object when it has finished with it.

  59995. */

  59996. static int walIteratorInit(Wal *pWal, u32 nBackfill, WalIterator **pp){

  59997.   WalIterator *p;                 /* Return value */

  59998.   int nSegment;                   /* Number of segments to merge */

  59999.   u32 iLast;                      /* Last frame in log */

  60000.   sqlite3_int64 nByte;            /* Number of bytes to allocate */

  60001.   int i;                          /* Iterator variable */

  60002.   ht_slot *aTmp;                  /* Temp space used by merge-sort */

  60003.   int rc = SQLITE_OK;             /* Return Code */

  60004. 

  60005.   /* This routine only runs while holding the checkpoint lock. And

  60006.   ** it only runs if there is actually content in the log (mxFrame>0).

  60007.   */

  60008.   assert( pWal->ckptLock && pWal->hdr.mxFrame>0 );

  60009.   iLast = pWal->hdr.mxFrame;

  60010. 

  60011.   /* Allocate space for the WalIterator object. */

  60012.   nSegment = walFramePage(iLast) + 1;

  60013.   nByte = sizeof(WalIterator) 

  60014.         + (nSegment-1)*sizeof(struct WalSegment)

  60015.         + iLast*sizeof(ht_slot);

  60016.   p = (WalIterator *)sqlite3_malloc64(nByte);

  60017.   if( !p ){

  60018.     return SQLITE_NOMEM_BKPT;

  60019.   }

  60020.   memset(p, 0, nByte);

  60021.   p->nSegment = nSegment;

  60022. 

  60023.   /* Allocate temporary space used by the merge-sort routine. This block

  60024.   ** of memory will be freed before this function returns.

  60025.   */

  60026.   aTmp = (ht_slot *)sqlite3_malloc64(

  60027.       sizeof(ht_slot) * (iLast>HASHTABLE_NPAGE?HASHTABLE_NPAGE:iLast)

  60028.   );

  60029.   if( !aTmp ){

  60030.     rc = SQLITE_NOMEM_BKPT;

  60031.   }

  60032. 

  60033.   for(i=walFramePage(nBackfill+1); rc==SQLITE_OK && i<nSegment; i++){

  60034.     WalHashLoc sLoc;

  60035. 

  60036.     rc = walHashGet(pWal, i, &sLoc);

  60037.     if( rc==SQLITE_OK ){

  60038.       int j;                      /* Counter variable */

  60039.       int nEntry;                 /* Number of entries in this segment */

  60040.       ht_slot *aIndex;            /* Sorted index for this segment */

  60041. 

  60042.       sLoc.aPgno++;

  60043.       if( (i+1)==nSegment ){

  60044.         nEntry = (int)(iLast - sLoc.iZero);

  60045.       }else{

  60046.         nEntry = (int)((u32*)sLoc.aHash - (u32*)sLoc.aPgno);

  60047.       }

  60048.       aIndex = &((ht_slot *)&p->aSegment[p->nSegment])[sLoc.iZero];

  60049.       sLoc.iZero++;

  60050.   

  60051.       for(j=0; j<nEntry; j++){

  60052.         aIndex[j] = (ht_slot)j;

  60053.       }

  60054.       walMergesort((u32 *)sLoc.aPgno, aTmp, aIndex, &nEntry);

  60055.       p->aSegment[i].iZero = sLoc.iZero;

  60056.       p->aSegment[i].nEntry = nEntry;

  60057.       p->aSegment[i].aIndex = aIndex;

  60058.       p->aSegment[i].aPgno = (u32 *)sLoc.aPgno;

  60059.     }

  60060.   }

  60061.   sqlite3_free(aTmp);

  60062. 

  60063.   if( rc!=SQLITE_OK ){

  60064.     walIteratorFree(p);

  60065.     p = 0;

  60066.   }

  60067.   *pp = p;

  60068.   return rc;

  60069. }

  60070. 

  60071. /*

  60072. ** Attempt to obtain the exclusive WAL lock defined by parameters lockIdx and

  60073. ** n. If the attempt fails and parameter xBusy is not NULL, then it is a

  60074. ** busy-handler function. Invoke it and retry the lock until either the

  60075. ** lock is successfully obtained or the busy-handler returns 0.

  60076. */

  60077. static int walBusyLock(

  60078.   Wal *pWal,                      /* WAL connection */

  60079.   int (*xBusy)(void*),            /* Function to call when busy */

  60080.   void *pBusyArg,                 /* Context argument for xBusyHandler */

  60081.   int lockIdx,                    /* Offset of first byte to lock */

  60082.   int n                           /* Number of bytes to lock */

  60083. ){

  60084.   int rc;

  60085.   do {

  60086.     rc = walLockExclusive(pWal, lockIdx, n);

  60087.   }while( xBusy && rc==SQLITE_BUSY && xBusy(pBusyArg) );

  60088.   return rc;

  60089. }

  60090. 

  60091. /*

  60092. ** The cache of the wal-index header must be valid to call this function.

  60093. ** Return the page-size in bytes used by the database.

  60094. */

  60095. static int walPagesize(Wal *pWal){

  60096.   return (pWal->hdr.szPage&0xfe00) + ((pWal->hdr.szPage&0x0001)<<16);

  60097. }

  60098. 

  60099. /*

  60100. ** The following is guaranteed when this function is called:

  60101. **

  60102. **   a) the WRITER lock is held,

  60103. **   b) the entire log file has been checkpointed, and

  60104. **   c) any existing readers are reading exclusively from the database

  60105. **      file - there are no readers that may attempt to read a frame from

  60106. **      the log file.

  60107. **

  60108. ** This function updates the shared-memory structures so that the next

  60109. ** client to write to the database (which may be this one) does so by

  60110. ** writing frames into the start of the log file.

  60111. **

  60112. ** The value of parameter salt1 is used as the aSalt[1] value in the 

  60113. ** new wal-index header. It should be passed a pseudo-random value (i.e. 

  60114. ** one obtained from sqlite3_randomness()).

  60115. */

  60116. static void walRestartHdr(Wal *pWal, u32 salt1){

  60117.   volatile WalCkptInfo *pInfo = walCkptInfo(pWal);

  60118.   int i;                          /* Loop counter */

  60119.   u32 *aSalt = pWal->hdr.aSalt;   /* Big-endian salt values */

  60120.   pWal->nCkpt++;

  60121.   pWal->hdr.mxFrame = 0;

  60122.   sqlite3Put4byte((u8*)&aSalt[0], 1 + sqlite3Get4byte((u8*)&aSalt[0]));

  60123.   memcpy(&pWal->hdr.aSalt[1], &salt1, 4);

  60124.   walIndexWriteHdr(pWal);

  60125.   pInfo->nBackfill = 0;

  60126.   pInfo->nBackfillAttempted = 0;

  60127.   pInfo->aReadMark[1] = 0;

  60128.   for(i=2; i<WAL_NREADER; i++) pInfo->aReadMark[i] = READMARK_NOT_USED;

  60129.   assert( pInfo->aReadMark[0]==0 );

  60130. }

  60131. 

  60132. /*

  60133. ** Copy as much content as we can from the WAL back into the database file

  60134. ** in response to an sqlite3_wal_checkpoint() request or the equivalent.

  60135. **

  60136. ** The amount of information copies from WAL to database might be limited

  60137. ** by active readers.  This routine will never overwrite a database page

  60138. ** that a concurrent reader might be using.

  60139. **

  60140. ** All I/O barrier operations (a.k.a fsyncs) occur in this routine when

  60141. ** SQLite is in WAL-mode in synchronous=NORMAL.  That means that if 

  60142. ** checkpoints are always run by a background thread or background 

  60143. ** process, foreground threads will never block on a lengthy fsync call.

  60144. **

  60145. ** Fsync is called on the WAL before writing content out of the WAL and

  60146. ** into the database.  This ensures that if the new content is persistent

  60147. ** in the WAL and can be recovered following a power-loss or hard reset.

  60148. **

  60149. ** Fsync is also called on the database file if (and only if) the entire

  60150. ** WAL content is copied into the database file.  This second fsync makes

  60151. ** it safe to delete the WAL since the new content will persist in the

  60152. ** database file.

  60153. **

  60154. ** This routine uses and updates the nBackfill field of the wal-index header.

  60155. ** This is the only routine that will increase the value of nBackfill.  

  60156. ** (A WAL reset or recovery will revert nBackfill to zero, but not increase

  60157. ** its value.)

  60158. **

  60159. ** The caller must be holding sufficient locks to ensure that no other

  60160. ** checkpoint is running (in any other thread or process) at the same

  60161. ** time.

  60162. */

  60163. static int walCheckpoint(

  60164.   Wal *pWal,                      /* Wal connection */

  60165.   sqlite3 *db,                    /* Check for interrupts on this handle */

  60166.   int eMode,                      /* One of PASSIVE, FULL or RESTART */

  60167.   int (*xBusy)(void*),            /* Function to call when busy */

  60168.   void *pBusyArg,                 /* Context argument for xBusyHandler */

  60169.   int sync_flags,                 /* Flags for OsSync() (or 0) */

  60170.   u8 *zBuf                        /* Temporary buffer to use */

  60171. ){

  60172.   int rc = SQLITE_OK;             /* Return code */

  60173.   int szPage;                     /* Database page-size */

  60174.   WalIterator *pIter = 0;         /* Wal iterator context */

  60175.   u32 iDbpage = 0;                /* Next database page to write */

  60176.   u32 iFrame = 0;                 /* Wal frame containing data for iDbpage */

  60177.   u32 mxSafeFrame;                /* Max frame that can be backfilled */

  60178.   u32 mxPage;                     /* Max database page to write */

  60179.   int i;                          /* Loop counter */

  60180.   volatile WalCkptInfo *pInfo;    /* The checkpoint status information */

  60181. 

  60182.   szPage = walPagesize(pWal);

  60183.   testcase( szPage<=32768 );

  60184.   testcase( szPage>=65536 );

  60185.   pInfo = walCkptInfo(pWal);

  60186.   if( pInfo->nBackfill<pWal->hdr.mxFrame ){

  60187. 

  60188.     /* EVIDENCE-OF: R-62920-47450 The busy-handler callback is never invoked

  60189.     ** in the SQLITE_CHECKPOINT_PASSIVE mode. */

  60190.     assert( eMode!=SQLITE_CHECKPOINT_PASSIVE || xBusy==0 );

  60191. 

  60192.     /* Compute in mxSafeFrame the index of the last frame of the WAL that is

  60193.     ** safe to write into the database.  Frames beyond mxSafeFrame might

  60194.     ** overwrite database pages that are in use by active readers and thus

  60195.     ** cannot be backfilled from the WAL.

  60196.     */

  60197.     mxSafeFrame = pWal->hdr.mxFrame;

  60198.     mxPage = pWal->hdr.nPage;

  60199.     for(i=1; i<WAL_NREADER; i++){

  60200.       /* Thread-sanitizer reports that the following is an unsafe read,

  60201.       ** as some other thread may be in the process of updating the value

  60202.       ** of the aReadMark[] slot. The assumption here is that if that is

  60203.       ** happening, the other client may only be increasing the value,

  60204.       ** not decreasing it. So assuming either that either the "old" or

  60205.       ** "new" version of the value is read, and not some arbitrary value

  60206.       ** that would never be written by a real client, things are still 

  60207.       ** safe.  */

  60208.       u32 y = pInfo->aReadMark[i];

  60209.       if( mxSafeFrame>y ){

  60210.         assert( y<=pWal->hdr.mxFrame );

  60211.         rc = walBusyLock(pWal, xBusy, pBusyArg, WAL_READ_LOCK(i), 1);

  60212.         if( rc==SQLITE_OK ){

  60213.           pInfo->aReadMark[i] = (i==1 ? mxSafeFrame : READMARK_NOT_USED);

  60214.           walUnlockExclusive(pWal, WAL_READ_LOCK(i), 1);

  60215.         }else if( rc==SQLITE_BUSY ){

  60216.           mxSafeFrame = y;

  60217.           xBusy = 0;

  60218.         }else{

  60219.           goto walcheckpoint_out;

  60220.         }

  60221.       }

  60222.     }

  60223. 

  60224.     /* Allocate the iterator */

  60225.     if( pInfo->nBackfill<mxSafeFrame ){

  60226.       rc = walIteratorInit(pWal, pInfo->nBackfill, &pIter);

  60227.       assert( rc==SQLITE_OK || pIter==0 );

  60228.     }

  60229. 

  60230.     if( pIter

  60231.      && (rc = walBusyLock(pWal, xBusy, pBusyArg, WAL_READ_LOCK(0),1))==SQLITE_OK

  60232.     ){

  60233.       u32 nBackfill = pInfo->nBackfill;

  60234. 

  60235.       pInfo->nBackfillAttempted = mxSafeFrame;

  60236. 

  60237.       /* Sync the WAL to disk */

  60238.       rc = sqlite3OsSync(pWal->pWalFd, CKPT_SYNC_FLAGS(sync_flags));

  60239. 

  60240.       /* If the database may grow as a result of this checkpoint, hint

  60241.       ** about the eventual size of the db file to the VFS layer.

  60242.       */

  60243.       if( rc==SQLITE_OK ){

  60244.         i64 nReq = ((i64)mxPage * szPage);

  60245.         i64 nSize;                    /* Current size of database file */

  60246.         rc = sqlite3OsFileSize(pWal->pDbFd, &nSize);

  60247.         if( rc==SQLITE_OK && nSize<nReq ){

  60248.           sqlite3OsFileControlHint(pWal->pDbFd, SQLITE_FCNTL_SIZE_HINT, &nReq);

  60249.         }

  60250.       }

  60251. 

  60252. 

  60253.       /* Iterate through the contents of the WAL, copying data to the db file */

  60254.       while( rc==SQLITE_OK && 0==walIteratorNext(pIter, &iDbpage, &iFrame) ){

  60255.         i64 iOffset;

  60256.         assert( walFramePgno(pWal, iFrame)==iDbpage );

  60257.         if( db->u1.isInterrupted ){

  60258.           rc = db->mallocFailed ? SQLITE_NOMEM_BKPT : SQLITE_INTERRUPT;

  60259.           break;

  60260.         }

  60261.         if( iFrame<=nBackfill || iFrame>mxSafeFrame || iDbpage>mxPage ){

  60262.           continue;

  60263.         }

  60264.         iOffset = walFrameOffset(iFrame, szPage) + WAL_FRAME_HDRSIZE;

  60265.         /* testcase( IS_BIG_INT(iOffset) ); // requires a 4GiB WAL file */

  60266.         rc = sqlite3OsRead(pWal->pWalFd, zBuf, szPage, iOffset);

  60267.         if( rc!=SQLITE_OK ) break;

  60268.         iOffset = (iDbpage-1)*(i64)szPage;

  60269.         testcase( IS_BIG_INT(iOffset) );

  60270.         rc = sqlite3OsWrite(pWal->pDbFd, zBuf, szPage, iOffset);

  60271.         if( rc!=SQLITE_OK ) break;

  60272.       }

  60273. 

  60274.       /* If work was actually accomplished... */

  60275.       if( rc==SQLITE_OK ){

  60276.         if( mxSafeFrame==walIndexHdr(pWal)->mxFrame ){

  60277.           i64 szDb = pWal->hdr.nPage*(i64)szPage;

  60278.           testcase( IS_BIG_INT(szDb) );

  60279.           rc = sqlite3OsTruncate(pWal->pDbFd, szDb);

  60280.           if( rc==SQLITE_OK ){

  60281.             rc = sqlite3OsSync(pWal->pDbFd, CKPT_SYNC_FLAGS(sync_flags));

  60282.           }

  60283.         }

  60284.         if( rc==SQLITE_OK ){

  60285.           pInfo->nBackfill = mxSafeFrame;

  60286.         }

  60287.       }

  60288. 

  60289.       /* Release the reader lock held while backfilling */

  60290.       walUnlockExclusive(pWal, WAL_READ_LOCK(0), 1);

  60291.     }

  60292. 

  60293.     if( rc==SQLITE_BUSY ){

  60294.       /* Reset the return code so as not to report a checkpoint failure

  60295.       ** just because there are active readers.  */

  60296.       rc = SQLITE_OK;

  60297.     }

  60298.   }

  60299. 

  60300.   /* If this is an SQLITE_CHECKPOINT_RESTART or TRUNCATE operation, and the

  60301.   ** entire wal file has been copied into the database file, then block 

  60302.   ** until all readers have finished using the wal file. This ensures that 

  60303.   ** the next process to write to the database restarts the wal file.

  60304.   */

  60305.   if( rc==SQLITE_OK && eMode!=SQLITE_CHECKPOINT_PASSIVE ){

  60306.     assert( pWal->writeLock );

  60307.     if( pInfo->nBackfill<pWal->hdr.mxFrame ){

  60308.       rc = SQLITE_BUSY;

  60309.     }else if( eMode>=SQLITE_CHECKPOINT_RESTART ){

  60310.       u32 salt1;

  60311.       sqlite3_randomness(4, &salt1);

  60312.       assert( pInfo->nBackfill==pWal->hdr.mxFrame );

  60313.       rc = walBusyLock(pWal, xBusy, pBusyArg, WAL_READ_LOCK(1), WAL_NREADER-1);

  60314.       if( rc==SQLITE_OK ){

  60315.         if( eMode==SQLITE_CHECKPOINT_TRUNCATE ){

  60316.           /* IMPLEMENTATION-OF: R-44699-57140 This mode works the same way as

  60317.           ** SQLITE_CHECKPOINT_RESTART with the addition that it also

  60318.           ** truncates the log file to zero bytes just prior to a

  60319.           ** successful return.

  60320.           **

  60321.           ** In theory, it might be safe to do this without updating the

  60322.           ** wal-index header in shared memory, as all subsequent reader or

  60323.           ** writer clients should see that the entire log file has been

  60324.           ** checkpointed and behave accordingly. This seems unsafe though,

  60325.           ** as it would leave the system in a state where the contents of

  60326.           ** the wal-index header do not match the contents of the 

  60327.           ** file-system. To avoid this, update the wal-index header to

  60328.           ** indicate that the log file contains zero valid frames.  */

  60329.           walRestartHdr(pWal, salt1);

  60330.           rc = sqlite3OsTruncate(pWal->pWalFd, 0);

  60331.         }

  60332.         walUnlockExclusive(pWal, WAL_READ_LOCK(1), WAL_NREADER-1);

  60333.       }

  60334.     }

  60335.   }

  60336. 

  60337.  walcheckpoint_out:

  60338.   walIteratorFree(pIter);

  60339.   return rc;

  60340. }

  60341. 

  60342. /*

  60343. ** If the WAL file is currently larger than nMax bytes in size, truncate

  60344. ** it to exactly nMax bytes. If an error occurs while doing so, ignore it.

  60345. */

  60346. static void walLimitSize(Wal *pWal, i64 nMax){

  60347.   i64 sz;

  60348.   int rx;

  60349.   sqlite3BeginBenignMalloc();

  60350.   rx = sqlite3OsFileSize(pWal->pWalFd, &sz);

  60351.   if( rx==SQLITE_OK && (sz > nMax ) ){

  60352.     rx = sqlite3OsTruncate(pWal->pWalFd, nMax);

  60353.   }

  60354.   sqlite3EndBenignMalloc();

  60355.   if( rx ){

  60356.     sqlite3_log(rx, "cannot limit WAL size: %s", pWal->zWalName);

  60357.   }

  60358. }

  60359. 

  60360. /*

  60361. ** Close a connection to a log file.

  60362. */

  60363. SQLITE_PRIVATE int sqlite3WalClose(

  60364.   Wal *pWal,                      /* Wal to close */

  60365.   sqlite3 *db,                    /* For interrupt flag */

  60366.   int sync_flags,                 /* Flags to pass to OsSync() (or 0) */

  60367.   int nBuf,

  60368.   u8 *zBuf                        /* Buffer of at least nBuf bytes */

  60369. ){

  60370.   int rc = SQLITE_OK;

  60371.   if( pWal ){

  60372.     int isDelete = 0;             /* True to unlink wal and wal-index files */

  60373. 

  60374.     /* If an EXCLUSIVE lock can be obtained on the database file (using the

  60375.     ** ordinary, rollback-mode locking methods, this guarantees that the

  60376.     ** connection associated with this log file is the only connection to

  60377.     ** the database. In this case checkpoint the database and unlink both

  60378.     ** the wal and wal-index files.

  60379.     **

  60380.     ** The EXCLUSIVE lock is not released before returning.

  60381.     */

  60382.     if( zBuf!=0

  60383.      && SQLITE_OK==(rc = sqlite3OsLock(pWal->pDbFd, SQLITE_LOCK_EXCLUSIVE))

  60384.     ){

  60385.       if( pWal->exclusiveMode==WAL_NORMAL_MODE ){

  60386.         pWal->exclusiveMode = WAL_EXCLUSIVE_MODE;

  60387.       }

  60388.       rc = sqlite3WalCheckpoint(pWal, db, 

  60389.           SQLITE_CHECKPOINT_PASSIVE, 0, 0, sync_flags, nBuf, zBuf, 0, 0

  60390.       );

  60391.       if( rc==SQLITE_OK ){

  60392.         int bPersist = -1;

  60393.         sqlite3OsFileControlHint(

  60394.             pWal->pDbFd, SQLITE_FCNTL_PERSIST_WAL, &bPersist

  60395.         );

  60396.         if( bPersist!=1 ){

  60397.           /* Try to delete the WAL file if the checkpoint completed and

  60398.           ** fsyned (rc==SQLITE_OK) and if we are not in persistent-wal

  60399.           ** mode (!bPersist) */

  60400.           isDelete = 1;

  60401.         }else if( pWal->mxWalSize>=0 ){

  60402.           /* Try to truncate the WAL file to zero bytes if the checkpoint

  60403.           ** completed and fsynced (rc==SQLITE_OK) and we are in persistent

  60404.           ** WAL mode (bPersist) and if the PRAGMA journal_size_limit is a

  60405.           ** non-negative value (pWal->mxWalSize>=0).  Note that we truncate

  60406.           ** to zero bytes as truncating to the journal_size_limit might

  60407.           ** leave a corrupt WAL file on disk. */

  60408.           walLimitSize(pWal, 0);

  60409.         }

  60410.       }

  60411.     }

  60412. 

  60413.     walIndexClose(pWal, isDelete);

  60414.     sqlite3OsClose(pWal->pWalFd);

  60415.     if( isDelete ){

  60416.       sqlite3BeginBenignMalloc();

  60417.       sqlite3OsDelete(pWal->pVfs, pWal->zWalName, 0);

  60418.       sqlite3EndBenignMalloc();

  60419.     }

  60420.     WALTRACE(("WAL%p: closed\n", pWal));

  60421.     sqlite3_free((void *)pWal->apWiData);

  60422.     sqlite3_free(pWal);

  60423.   }

  60424.   return rc;

  60425. }

  60426. 

  60427. /*

  60428. ** Try to read the wal-index header.  Return 0 on success and 1 if

  60429. ** there is a problem.

  60430. **

  60431. ** The wal-index is in shared memory.  Another thread or process might

  60432. ** be writing the header at the same time this procedure is trying to

  60433. ** read it, which might result in inconsistency.  A dirty read is detected

  60434. ** by verifying that both copies of the header are the same and also by

  60435. ** a checksum on the header.

  60436. **

  60437. ** If and only if the read is consistent and the header is different from

  60438. ** pWal->hdr, then pWal->hdr is updated to the content of the new header

  60439. ** and *pChanged is set to 1.

  60440. **

  60441. ** If the checksum cannot be verified return non-zero. If the header

  60442. ** is read successfully and the checksum verified, return zero.

  60443. */

  60444. static int walIndexTryHdr(Wal *pWal, int *pChanged){

  60445.   u32 aCksum[2];                  /* Checksum on the header content */

  60446.   WalIndexHdr h1, h2;             /* Two copies of the header content */

  60447.   WalIndexHdr volatile *aHdr;     /* Header in shared memory */

  60448. 

  60449.   /* The first page of the wal-index must be mapped at this point. */

  60450.   assert( pWal->nWiData>0 && pWal->apWiData[0] );

  60451. 

  60452.   /* Read the header. This might happen concurrently with a write to the

  60453.   ** same area of shared memory on a different CPU in a SMP,

  60454.   ** meaning it is possible that an inconsistent snapshot is read

  60455.   ** from the file. If this happens, return non-zero.

  60456.   **

  60457.   ** There are two copies of the header at the beginning of the wal-index.

  60458.   ** When reading, read [0] first then [1].  Writes are in the reverse order.

  60459.   ** Memory barriers are used to prevent the compiler or the hardware from

  60460.   ** reordering the reads and writes.

  60461.   */

  60462.   aHdr = walIndexHdr(pWal);

  60463.   memcpy(&h1, (void *)&aHdr[0], sizeof(h1));

  60464.   walShmBarrier(pWal);

  60465.   memcpy(&h2, (void *)&aHdr[1], sizeof(h2));

  60466. 

  60467.   if( memcmp(&h1, &h2, sizeof(h1))!=0 ){

  60468.     return 1;   /* Dirty read */

  60469.   }  

  60470.   if( h1.isInit==0 ){

  60471.     return 1;   /* Malformed header - probably all zeros */

  60472.   }

  60473.   walChecksumBytes(1, (u8*)&h1, sizeof(h1)-sizeof(h1.aCksum), 0, aCksum);

  60474.   if( aCksum[0]!=h1.aCksum[0] || aCksum[1]!=h1.aCksum[1] ){

  60475.     return 1;   /* Checksum does not match */

  60476.   }

  60477. 

  60478.   if( memcmp(&pWal->hdr, &h1, sizeof(WalIndexHdr)) ){

  60479.     *pChanged = 1;

  60480.     memcpy(&pWal->hdr, &h1, sizeof(WalIndexHdr));

  60481.     pWal->szPage = (pWal->hdr.szPage&0xfe00) + ((pWal->hdr.szPage&0x0001)<<16);

  60482.     testcase( pWal->szPage<=32768 );

  60483.     testcase( pWal->szPage>=65536 );

  60484.   }

  60485. 

  60486.   /* The header was successfully read. Return zero. */

  60487.   return 0;

  60488. }

  60489. 

  60490. /*

  60491. ** This is the value that walTryBeginRead returns when it needs to

  60492. ** be retried.

  60493. */

  60494. #define WAL_RETRY  (-1)

  60495. 

  60496. /*

  60497. ** Read the wal-index header from the wal-index and into pWal->hdr.

  60498. ** If the wal-header appears to be corrupt, try to reconstruct the

  60499. ** wal-index from the WAL before returning.

  60500. **

  60501. ** Set *pChanged to 1 if the wal-index header value in pWal->hdr is

  60502. ** changed by this operation.  If pWal->hdr is unchanged, set *pChanged

  60503. ** to 0.

  60504. **

  60505. ** If the wal-index header is successfully read, return SQLITE_OK. 

  60506. ** Otherwise an SQLite error code.

  60507. */

  60508. static int walIndexReadHdr(Wal *pWal, int *pChanged){

  60509.   int rc;                         /* Return code */

  60510.   int badHdr;                     /* True if a header read failed */

  60511.   volatile u32 *page0;            /* Chunk of wal-index containing header */

  60512. 

  60513.   /* Ensure that page 0 of the wal-index (the page that contains the 

  60514.   ** wal-index header) is mapped. Return early if an error occurs here.

  60515.   */

  60516.   assert( pChanged );

  60517.   rc = walIndexPage(pWal, 0, &page0);

  60518.   if( rc!=SQLITE_OK ){

  60519.     assert( rc!=SQLITE_READONLY ); /* READONLY changed to OK in walIndexPage */

  60520.     if( rc==SQLITE_READONLY_CANTINIT ){

  60521.       /* The SQLITE_READONLY_CANTINIT return means that the shared-memory

  60522.       ** was openable but is not writable, and this thread is unable to

  60523.       ** confirm that another write-capable connection has the shared-memory

  60524.       ** open, and hence the content of the shared-memory is unreliable,

  60525.       ** since the shared-memory might be inconsistent with the WAL file

  60526.       ** and there is no writer on hand to fix it. */

  60527.       assert( page0==0 );

  60528.       assert( pWal->writeLock==0 );

  60529.       assert( pWal->readOnly & WAL_SHM_RDONLY );

  60530.       pWal->bShmUnreliable = 1;

  60531.       pWal->exclusiveMode = WAL_HEAPMEMORY_MODE;

  60532.       *pChanged = 1;

  60533.     }else{

  60534.       return rc; /* Any other non-OK return is just an error */

  60535.     }

  60536.   }else{

  60537.     /* page0 can be NULL if the SHM is zero bytes in size and pWal->writeLock

  60538.     ** is zero, which prevents the SHM from growing */

  60539.     testcase( page0!=0 );

  60540.   }

  60541.   assert( page0!=0 || pWal->writeLock==0 );

  60542. 

  60543.   /* If the first page of the wal-index has been mapped, try to read the

  60544.   ** wal-index header immediately, without holding any lock. This usually

  60545.   ** works, but may fail if the wal-index header is corrupt or currently 

  60546.   ** being modified by another thread or process.

  60547.   */

  60548.   badHdr = (page0 ? walIndexTryHdr(pWal, pChanged) : 1);

  60549. 

  60550.   /* If the first attempt failed, it might have been due to a race

  60551.   ** with a writer.  So get a WRITE lock and try again.

  60552.   */

  60553.   assert( badHdr==0 || pWal->writeLock==0 );

  60554.   if( badHdr ){

  60555.     if( pWal->bShmUnreliable==0 && (pWal->readOnly & WAL_SHM_RDONLY) ){

  60556.       if( SQLITE_OK==(rc = walLockShared(pWal, WAL_WRITE_LOCK)) ){

  60557.         walUnlockShared(pWal, WAL_WRITE_LOCK);

  60558.         rc = SQLITE_READONLY_RECOVERY;

  60559.       }

  60560.     }else if( SQLITE_OK==(rc = walLockExclusive(pWal, WAL_WRITE_LOCK, 1)) ){

  60561.       pWal->writeLock = 1;

  60562.       if( SQLITE_OK==(rc = walIndexPage(pWal, 0, &page0)) ){

  60563.         badHdr = walIndexTryHdr(pWal, pChanged);

  60564.         if( badHdr ){

  60565.           /* If the wal-index header is still malformed even while holding

  60566.           ** a WRITE lock, it can only mean that the header is corrupted and

  60567.           ** needs to be reconstructed.  So run recovery to do exactly that.

  60568.           */

  60569.           rc = walIndexRecover(pWal);

  60570.           *pChanged = 1;

  60571.         }

  60572.       }

  60573.       pWal->writeLock = 0;

  60574.       walUnlockExclusive(pWal, WAL_WRITE_LOCK, 1);

  60575.     }

  60576.   }

  60577. 

  60578.   /* If the header is read successfully, check the version number to make

  60579.   ** sure the wal-index was not constructed with some future format that

  60580.   ** this version of SQLite cannot understand.

  60581.   */

  60582.   if( badHdr==0 && pWal->hdr.iVersion!=WALINDEX_MAX_VERSION ){

  60583.     rc = SQLITE_CANTOPEN_BKPT;

  60584.   }

  60585.   if( pWal->bShmUnreliable ){

  60586.     if( rc!=SQLITE_OK ){

  60587.       walIndexClose(pWal, 0);

  60588.       pWal->bShmUnreliable = 0;

  60589.       assert( pWal->nWiData>0 && pWal->apWiData[0]==0 );

  60590.       /* walIndexRecover() might have returned SHORT_READ if a concurrent

  60591.       ** writer truncated the WAL out from under it.  If that happens, it

  60592.       ** indicates that a writer has fixed the SHM file for us, so retry */

  60593.       if( rc==SQLITE_IOERR_SHORT_READ ) rc = WAL_RETRY;

  60594.     }

  60595.     pWal->exclusiveMode = WAL_NORMAL_MODE;

  60596.   }

  60597. 

  60598.   return rc;

  60599. }

  60600. 

  60601. /*

  60602. ** Open a transaction in a connection where the shared-memory is read-only

  60603. ** and where we cannot verify that there is a separate write-capable connection

  60604. ** on hand to keep the shared-memory up-to-date with the WAL file.

  60605. **

  60606. ** This can happen, for example, when the shared-memory is implemented by

  60607. ** memory-mapping a *-shm file, where a prior writer has shut down and

  60608. ** left the *-shm file on disk, and now the present connection is trying

  60609. ** to use that database but lacks write permission on the *-shm file.

  60610. ** Other scenarios are also possible, depending on the VFS implementation.

  60611. **

  60612. ** Precondition:

  60613. **

  60614. **    The *-wal file has been read and an appropriate wal-index has been

  60615. **    constructed in pWal->apWiData[] using heap memory instead of shared

  60616. **    memory. 

  60617. **

  60618. ** If this function returns SQLITE_OK, then the read transaction has

  60619. ** been successfully opened. In this case output variable (*pChanged) 

  60620. ** is set to true before returning if the caller should discard the

  60621. ** contents of the page cache before proceeding. Or, if it returns 

  60622. ** WAL_RETRY, then the heap memory wal-index has been discarded and 

  60623. ** the caller should retry opening the read transaction from the 

  60624. ** beginning (including attempting to map the *-shm file). 

  60625. **

  60626. ** If an error occurs, an SQLite error code is returned.

  60627. */

  60628. static int walBeginShmUnreliable(Wal *pWal, int *pChanged){

  60629.   i64 szWal;                      /* Size of wal file on disk in bytes */

  60630.   i64 iOffset;                    /* Current offset when reading wal file */

  60631.   u8 aBuf[WAL_HDRSIZE];           /* Buffer to load WAL header into */

  60632.   u8 *aFrame = 0;                 /* Malloc'd buffer to load entire frame */

  60633.   int szFrame;                    /* Number of bytes in buffer aFrame[] */

  60634.   u8 *aData;                      /* Pointer to data part of aFrame buffer */

  60635.   volatile void *pDummy;          /* Dummy argument for xShmMap */

  60636.   int rc;                         /* Return code */

  60637.   u32 aSaveCksum[2];              /* Saved copy of pWal->hdr.aFrameCksum */

  60638. 

  60639.   assert( pWal->bShmUnreliable );

  60640.   assert( pWal->readOnly & WAL_SHM_RDONLY );

  60641.   assert( pWal->nWiData>0 && pWal->apWiData[0] );

  60642. 

  60643.   /* Take WAL_READ_LOCK(0). This has the effect of preventing any

  60644.   ** writers from running a checkpoint, but does not stop them

  60645.   ** from running recovery.  */

  60646.   rc = walLockShared(pWal, WAL_READ_LOCK(0));

  60647.   if( rc!=SQLITE_OK ){

  60648.     if( rc==SQLITE_BUSY ) rc = WAL_RETRY;

  60649.     goto begin_unreliable_shm_out;

  60650.   }

  60651.   pWal->readLock = 0;

  60652. 

  60653.   /* Check to see if a separate writer has attached to the shared-memory area,

  60654.   ** thus making the shared-memory "reliable" again.  Do this by invoking

  60655.   ** the xShmMap() routine of the VFS and looking to see if the return

  60656.   ** is SQLITE_READONLY instead of SQLITE_READONLY_CANTINIT.

  60657.   **

  60658.   ** If the shared-memory is now "reliable" return WAL_RETRY, which will

  60659.   ** cause the heap-memory WAL-index to be discarded and the actual

  60660.   ** shared memory to be used in its place.

  60661.   **

  60662.   ** This step is important because, even though this connection is holding

  60663.   ** the WAL_READ_LOCK(0) which prevents a checkpoint, a writer might

  60664.   ** have already checkpointed the WAL file and, while the current

  60665.   ** is active, wrap the WAL and start overwriting frames that this

  60666.   ** process wants to use.

  60667.   **

  60668.   ** Once sqlite3OsShmMap() has been called for an sqlite3_file and has

  60669.   ** returned any SQLITE_READONLY value, it must return only SQLITE_READONLY

  60670.   ** or SQLITE_READONLY_CANTINIT or some error for all subsequent invocations,

  60671.   ** even if some external agent does a "chmod" to make the shared-memory

  60672.   ** writable by us, until sqlite3OsShmUnmap() has been called.

  60673.   ** This is a requirement on the VFS implementation.

  60674.    */

  60675.   rc = sqlite3OsShmMap(pWal->pDbFd, 0, WALINDEX_PGSZ, 0, &pDummy);

  60676.   assert( rc!=SQLITE_OK ); /* SQLITE_OK not possible for read-only connection */

  60677.   if( rc!=SQLITE_READONLY_CANTINIT ){

  60678.     rc = (rc==SQLITE_READONLY ? WAL_RETRY : rc);

  60679.     goto begin_unreliable_shm_out;

  60680.   }

  60681. 

  60682.   /* We reach this point only if the real shared-memory is still unreliable.

  60683.   ** Assume the in-memory WAL-index substitute is correct and load it

  60684.   ** into pWal->hdr.

  60685.   */

  60686.   memcpy(&pWal->hdr, (void*)walIndexHdr(pWal), sizeof(WalIndexHdr));

  60687. 

  60688.   /* Make sure some writer hasn't come in and changed the WAL file out

  60689.   ** from under us, then disconnected, while we were not looking.

  60690.   */

  60691.   rc = sqlite3OsFileSize(pWal->pWalFd, &szWal);

  60692.   if( rc!=SQLITE_OK ){

  60693.     goto begin_unreliable_shm_out;

  60694.   }

  60695.   if( szWal<WAL_HDRSIZE ){

  60696.     /* If the wal file is too small to contain a wal-header and the

  60697.     ** wal-index header has mxFrame==0, then it must be safe to proceed

  60698.     ** reading the database file only. However, the page cache cannot

  60699.     ** be trusted, as a read/write connection may have connected, written

  60700.     ** the db, run a checkpoint, truncated the wal file and disconnected

  60701.     ** since this client's last read transaction.  */

  60702.     *pChanged = 1;

  60703.     rc = (pWal->hdr.mxFrame==0 ? SQLITE_OK : WAL_RETRY);

  60704.     goto begin_unreliable_shm_out;

  60705.   }

  60706. 

  60707.   /* Check the salt keys at the start of the wal file still match. */

  60708.   rc = sqlite3OsRead(pWal->pWalFd, aBuf, WAL_HDRSIZE, 0);

  60709.   if( rc!=SQLITE_OK ){

  60710.     goto begin_unreliable_shm_out;

  60711.   }

  60712.   if( memcmp(&pWal->hdr.aSalt, &aBuf[16], 8) ){

  60713.     /* Some writer has wrapped the WAL file while we were not looking.

  60714.     ** Return WAL_RETRY which will cause the in-memory WAL-index to be

  60715.     ** rebuilt. */

  60716.     rc = WAL_RETRY;

  60717.     goto begin_unreliable_shm_out;

  60718.   }

  60719. 

  60720.   /* Allocate a buffer to read frames into */

  60721.   szFrame = pWal->hdr.szPage + WAL_FRAME_HDRSIZE;

  60722.   aFrame = (u8 *)sqlite3_malloc64(szFrame);

  60723.   if( aFrame==0 ){

  60724.     rc = SQLITE_NOMEM_BKPT;

  60725.     goto begin_unreliable_shm_out;

  60726.   }

  60727.   aData = &aFrame[WAL_FRAME_HDRSIZE];

  60728. 

  60729.   /* Check to see if a complete transaction has been appended to the

  60730.   ** wal file since the heap-memory wal-index was created. If so, the

  60731.   ** heap-memory wal-index is discarded and WAL_RETRY returned to

  60732.   ** the caller.  */

  60733.   aSaveCksum[0] = pWal->hdr.aFrameCksum[0];

  60734.   aSaveCksum[1] = pWal->hdr.aFrameCksum[1];

  60735.   for(iOffset=walFrameOffset(pWal->hdr.mxFrame+1, pWal->hdr.szPage); 

  60736.       iOffset+szFrame<=szWal; 

  60737.       iOffset+=szFrame

  60738.   ){

  60739.     u32 pgno;                   /* Database page number for frame */

  60740.     u32 nTruncate;              /* dbsize field from frame header */

  60741. 

  60742.     /* Read and decode the next log frame. */

  60743.     rc = sqlite3OsRead(pWal->pWalFd, aFrame, szFrame, iOffset);

  60744.     if( rc!=SQLITE_OK ) break;

  60745.     if( !walDecodeFrame(pWal, &pgno, &nTruncate, aData, aFrame) ) break;

  60746. 

  60747.     /* If nTruncate is non-zero, then a complete transaction has been

  60748.     ** appended to this wal file. Set rc to WAL_RETRY and break out of

  60749.     ** the loop.  */

  60750.     if( nTruncate ){

  60751.       rc = WAL_RETRY;

  60752.       break;

  60753.     }

  60754.   }

  60755.   pWal->hdr.aFrameCksum[0] = aSaveCksum[0];

  60756.   pWal->hdr.aFrameCksum[1] = aSaveCksum[1];

  60757. 

  60758.  begin_unreliable_shm_out:

  60759.   sqlite3_free(aFrame);

  60760.   if( rc!=SQLITE_OK ){

  60761.     int i;

  60762.     for(i=0; i<pWal->nWiData; i++){

  60763.       sqlite3_free((void*)pWal->apWiData[i]);

  60764.       pWal->apWiData[i] = 0;

  60765.     }

  60766.     pWal->bShmUnreliable = 0;

  60767.     sqlite3WalEndReadTransaction(pWal);

  60768.     *pChanged = 1;

  60769.   }

  60770.   return rc;

  60771. }

  60772. 

  60773. /*

  60774. ** Attempt to start a read transaction.  This might fail due to a race or

  60775. ** other transient condition.  When that happens, it returns WAL_RETRY to

  60776. ** indicate to the caller that it is safe to retry immediately.

  60777. **

  60778. ** On success return SQLITE_OK.  On a permanent failure (such an

  60779. ** I/O error or an SQLITE_BUSY because another process is running

  60780. ** recovery) return a positive error code.

  60781. **

  60782. ** The useWal parameter is true to force the use of the WAL and disable

  60783. ** the case where the WAL is bypassed because it has been completely

  60784. ** checkpointed.  If useWal==0 then this routine calls walIndexReadHdr() 

  60785. ** to make a copy of the wal-index header into pWal->hdr.  If the 

  60786. ** wal-index header has changed, *pChanged is set to 1 (as an indication 

  60787. ** to the caller that the local page cache is obsolete and needs to be 

  60788. ** flushed.)  When useWal==1, the wal-index header is assumed to already

  60789. ** be loaded and the pChanged parameter is unused.

  60790. **

  60791. ** The caller must set the cnt parameter to the number of prior calls to

  60792. ** this routine during the current read attempt that returned WAL_RETRY.

  60793. ** This routine will start taking more aggressive measures to clear the

  60794. ** race conditions after multiple WAL_RETRY returns, and after an excessive

  60795. ** number of errors will ultimately return SQLITE_PROTOCOL.  The

  60796. ** SQLITE_PROTOCOL return indicates that some other process has gone rogue

  60797. ** and is not honoring the locking protocol.  There is a vanishingly small

  60798. ** chance that SQLITE_PROTOCOL could be returned because of a run of really

  60799. ** bad luck when there is lots of contention for the wal-index, but that

  60800. ** possibility is so small that it can be safely neglected, we believe.

  60801. **

  60802. ** On success, this routine obtains a read lock on 

  60803. ** WAL_READ_LOCK(pWal->readLock).  The pWal->readLock integer is

  60804. ** in the range 0 <= pWal->readLock < WAL_NREADER.  If pWal->readLock==(-1)

  60805. ** that means the Wal does not hold any read lock.  The reader must not

  60806. ** access any database page that is modified by a WAL frame up to and

  60807. ** including frame number aReadMark[pWal->readLock].  The reader will

  60808. ** use WAL frames up to and including pWal->hdr.mxFrame if pWal->readLock>0

  60809. ** Or if pWal->readLock==0, then the reader will ignore the WAL

  60810. ** completely and get all content directly from the database file.

  60811. ** If the useWal parameter is 1 then the WAL will never be ignored and

  60812. ** this routine will always set pWal->readLock>0 on success.

  60813. ** When the read transaction is completed, the caller must release the

  60814. ** lock on WAL_READ_LOCK(pWal->readLock) and set pWal->readLock to -1.

  60815. **

  60816. ** This routine uses the nBackfill and aReadMark[] fields of the header

  60817. ** to select a particular WAL_READ_LOCK() that strives to let the

  60818. ** checkpoint process do as much work as possible.  This routine might

  60819. ** update values of the aReadMark[] array in the header, but if it does

  60820. ** so it takes care to hold an exclusive lock on the corresponding

  60821. ** WAL_READ_LOCK() while changing values.

  60822. */

  60823. static int walTryBeginRead(Wal *pWal, int *pChanged, int useWal, int cnt){

  60824.   volatile WalCkptInfo *pInfo;    /* Checkpoint information in wal-index */

  60825.   u32 mxReadMark;                 /* Largest aReadMark[] value */

  60826.   int mxI;                        /* Index of largest aReadMark[] value */

  60827.   int i;                          /* Loop counter */

  60828.   int rc = SQLITE_OK;             /* Return code  */

  60829.   u32 mxFrame;                    /* Wal frame to lock to */

  60830. 

  60831.   assert( pWal->readLock<0 );     /* Not currently locked */

  60832. 

  60833.   /* useWal may only be set for read/write connections */

  60834.   assert( (pWal->readOnly & WAL_SHM_RDONLY)==0 || useWal==0 );

  60835. 

  60836.   /* Take steps to avoid spinning forever if there is a protocol error.

  60837.   **

  60838.   ** Circumstances that cause a RETRY should only last for the briefest

  60839.   ** instances of time.  No I/O or other system calls are done while the

  60840.   ** locks are held, so the locks should not be held for very long. But 

  60841.   ** if we are unlucky, another process that is holding a lock might get

  60842.   ** paged out or take a page-fault that is time-consuming to resolve, 

  60843.   ** during the few nanoseconds that it is holding the lock.  In that case,

  60844.   ** it might take longer than normal for the lock to free.

  60845.   **

  60846.   ** After 5 RETRYs, we begin calling sqlite3OsSleep().  The first few

  60847.   ** calls to sqlite3OsSleep() have a delay of 1 microsecond.  Really this

  60848.   ** is more of a scheduler yield than an actual delay.  But on the 10th

  60849.   ** an subsequent retries, the delays start becoming longer and longer, 

  60850.   ** so that on the 100th (and last) RETRY we delay for 323 milliseconds.

  60851.   ** The total delay time before giving up is less than 10 seconds.

  60852.   */

  60853.   if( cnt>5 ){

  60854.     int nDelay = 1;                      /* Pause time in microseconds */

  60855.     if( cnt>100 ){

  60856.       VVA_ONLY( pWal->lockError = 1; )

  60857.       return SQLITE_PROTOCOL;

  60858.     }

  60859.     if( cnt>=10 ) nDelay = (cnt-9)*(cnt-9)*39;

  60860.     sqlite3OsSleep(pWal->pVfs, nDelay);

  60861.   }

  60862. 

  60863.   if( !useWal ){

  60864.     assert( rc==SQLITE_OK );

  60865.     if( pWal->bShmUnreliable==0 ){

  60866.       rc = walIndexReadHdr(pWal, pChanged);

  60867.     }

  60868.     if( rc==SQLITE_BUSY ){

  60869.       /* If there is not a recovery running in another thread or process

  60870.       ** then convert BUSY errors to WAL_RETRY.  If recovery is known to

  60871.       ** be running, convert BUSY to BUSY_RECOVERY.  There is a race here

  60872.       ** which might cause WAL_RETRY to be returned even if BUSY_RECOVERY

  60873.       ** would be technically correct.  But the race is benign since with

  60874.       ** WAL_RETRY this routine will be called again and will probably be

  60875.       ** right on the second iteration.

  60876.       */

  60877.       if( pWal->apWiData[0]==0 ){

  60878.         /* This branch is taken when the xShmMap() method returns SQLITE_BUSY.

  60879.         ** We assume this is a transient condition, so return WAL_RETRY. The

  60880.         ** xShmMap() implementation used by the default unix and win32 VFS 

  60881.         ** modules may return SQLITE_BUSY due to a race condition in the 

  60882.         ** code that determines whether or not the shared-memory region 

  60883.         ** must be zeroed before the requested page is returned.

  60884.         */

  60885.         rc = WAL_RETRY;

  60886.       }else if( SQLITE_OK==(rc = walLockShared(pWal, WAL_RECOVER_LOCK)) ){

  60887.         walUnlockShared(pWal, WAL_RECOVER_LOCK);

  60888.         rc = WAL_RETRY;

  60889.       }else if( rc==SQLITE_BUSY ){

  60890.         rc = SQLITE_BUSY_RECOVERY;

  60891.       }

  60892.     }

  60893.     if( rc!=SQLITE_OK ){

  60894.       return rc;

  60895.     }

  60896.     else if( pWal->bShmUnreliable ){

  60897.       return walBeginShmUnreliable(pWal, pChanged);

  60898.     }

  60899.   }

  60900. 

  60901.   assert( pWal->nWiData>0 );

  60902.   assert( pWal->apWiData[0]!=0 );

  60903.   pInfo = walCkptInfo(pWal);

  60904.   if( !useWal && pInfo->nBackfill==pWal->hdr.mxFrame

  60905. #ifdef SQLITE_ENABLE_SNAPSHOT

  60906.    && (pWal->pSnapshot==0 || pWal->hdr.mxFrame==0)

  60907. #endif

  60908.   ){

  60909.     /* The WAL has been completely backfilled (or it is empty).

  60910.     ** and can be safely ignored.

  60911.     */

  60912.     rc = walLockShared(pWal, WAL_READ_LOCK(0));

  60913.     walShmBarrier(pWal);

  60914.     if( rc==SQLITE_OK ){

  60915.       if( memcmp((void *)walIndexHdr(pWal), &pWal->hdr, sizeof(WalIndexHdr)) ){

  60916.         /* It is not safe to allow the reader to continue here if frames

  60917.         ** may have been appended to the log before READ_LOCK(0) was obtained.

  60918.         ** When holding READ_LOCK(0), the reader ignores the entire log file,

  60919.         ** which implies that the database file contains a trustworthy

  60920.         ** snapshot. Since holding READ_LOCK(0) prevents a checkpoint from

  60921.         ** happening, this is usually correct.

  60922.         **

  60923.         ** However, if frames have been appended to the log (or if the log 

  60924.         ** is wrapped and written for that matter) before the READ_LOCK(0)

  60925.         ** is obtained, that is not necessarily true. A checkpointer may

  60926.         ** have started to backfill the appended frames but crashed before

  60927.         ** it finished. Leaving a corrupt image in the database file.

  60928.         */

  60929.         walUnlockShared(pWal, WAL_READ_LOCK(0));

  60930.         return WAL_RETRY;

  60931.       }

  60932.       pWal->readLock = 0;

  60933.       return SQLITE_OK;

  60934.     }else if( rc!=SQLITE_BUSY ){

  60935.       return rc;

  60936.     }

  60937.   }

  60938. 

  60939.   /* If we get this far, it means that the reader will want to use

  60940.   ** the WAL to get at content from recent commits.  The job now is

  60941.   ** to select one of the aReadMark[] entries that is closest to

  60942.   ** but not exceeding pWal->hdr.mxFrame and lock that entry.

  60943.   */

  60944.   mxReadMark = 0;

  60945.   mxI = 0;

  60946.   mxFrame = pWal->hdr.mxFrame;

  60947. #ifdef SQLITE_ENABLE_SNAPSHOT

  60948.   if( pWal->pSnapshot && pWal->pSnapshot->mxFrame<mxFrame ){

  60949.     mxFrame = pWal->pSnapshot->mxFrame;

  60950.   }

  60951. #endif

  60952.   for(i=1; i<WAL_NREADER; i++){

  60953.     u32 thisMark = AtomicLoad(pInfo->aReadMark+i);

  60954.     if( mxReadMark<=thisMark && thisMark<=mxFrame ){

  60955.       assert( thisMark!=READMARK_NOT_USED );

  60956.       mxReadMark = thisMark;

  60957.       mxI = i;

  60958.     }

  60959.   }

  60960.   if( (pWal->readOnly & WAL_SHM_RDONLY)==0

  60961.    && (mxReadMark<mxFrame || mxI==0)

  60962.   ){

  60963.     for(i=1; i<WAL_NREADER; i++){

  60964.       rc = walLockExclusive(pWal, WAL_READ_LOCK(i), 1);

  60965.       if( rc==SQLITE_OK ){

  60966.         mxReadMark = AtomicStore(pInfo->aReadMark+i,mxFrame);

  60967.         mxI = i;

  60968.         walUnlockExclusive(pWal, WAL_READ_LOCK(i), 1);

  60969.         break;

  60970.       }else if( rc!=SQLITE_BUSY ){

  60971.         return rc;

  60972.       }

  60973.     }

  60974.   }

  60975.   if( mxI==0 ){

  60976.     assert( rc==SQLITE_BUSY || (pWal->readOnly & WAL_SHM_RDONLY)!=0 );

  60977.     return rc==SQLITE_BUSY ? WAL_RETRY : SQLITE_READONLY_CANTINIT;

  60978.   }

  60979. 

  60980.   rc = walLockShared(pWal, WAL_READ_LOCK(mxI));

  60981.   if( rc ){

  60982.     return rc==SQLITE_BUSY ? WAL_RETRY : rc;

  60983.   }

  60984.   /* Now that the read-lock has been obtained, check that neither the

  60985.   ** value in the aReadMark[] array or the contents of the wal-index

  60986.   ** header have changed.

  60987.   **

  60988.   ** It is necessary to check that the wal-index header did not change

  60989.   ** between the time it was read and when the shared-lock was obtained

  60990.   ** on WAL_READ_LOCK(mxI) was obtained to account for the possibility

  60991.   ** that the log file may have been wrapped by a writer, or that frames

  60992.   ** that occur later in the log than pWal->hdr.mxFrame may have been

  60993.   ** copied into the database by a checkpointer. If either of these things

  60994.   ** happened, then reading the database with the current value of

  60995.   ** pWal->hdr.mxFrame risks reading a corrupted snapshot. So, retry

  60996.   ** instead.

  60997.   **

  60998.   ** Before checking that the live wal-index header has not changed

  60999.   ** since it was read, set Wal.minFrame to the first frame in the wal

  61000.   ** file that has not yet been checkpointed. This client will not need

  61001.   ** to read any frames earlier than minFrame from the wal file - they

  61002.   ** can be safely read directly from the database file.

  61003.   **

  61004.   ** Because a ShmBarrier() call is made between taking the copy of 

  61005.   ** nBackfill and checking that the wal-header in shared-memory still

  61006.   ** matches the one cached in pWal->hdr, it is guaranteed that the 

  61007.   ** checkpointer that set nBackfill was not working with a wal-index

  61008.   ** header newer than that cached in pWal->hdr. If it were, that could

  61009.   ** cause a problem. The checkpointer could omit to checkpoint

  61010.   ** a version of page X that lies before pWal->minFrame (call that version

  61011.   ** A) on the basis that there is a newer version (version B) of the same

  61012.   ** page later in the wal file. But if version B happens to like past

  61013.   ** frame pWal->hdr.mxFrame - then the client would incorrectly assume

  61014.   ** that it can read version A from the database file. However, since

  61015.   ** we can guarantee that the checkpointer that set nBackfill could not

  61016.   ** see any pages past pWal->hdr.mxFrame, this problem does not come up.

  61017.   */

  61018.   pWal->minFrame = AtomicLoad(&pInfo->nBackfill)+1;

  61019.   walShmBarrier(pWal);

  61020.   if( AtomicLoad(pInfo->aReadMark+mxI)!=mxReadMark

  61021.    || memcmp((void *)walIndexHdr(pWal), &pWal->hdr, sizeof(WalIndexHdr))

  61022.   ){

  61023.     walUnlockShared(pWal, WAL_READ_LOCK(mxI));

  61024.     return WAL_RETRY;

  61025.   }else{

  61026.     assert( mxReadMark<=pWal->hdr.mxFrame );

  61027.     pWal->readLock = (i16)mxI;

  61028.   }

  61029.   return rc;

  61030. }

  61031. 

  61032. #ifdef SQLITE_ENABLE_SNAPSHOT

  61033. /*

  61034. ** Attempt to reduce the value of the WalCkptInfo.nBackfillAttempted 

  61035. ** variable so that older snapshots can be accessed. To do this, loop

  61036. ** through all wal frames from nBackfillAttempted to (nBackfill+1), 

  61037. ** comparing their content to the corresponding page with the database

  61038. ** file, if any. Set nBackfillAttempted to the frame number of the

  61039. ** first frame for which the wal file content matches the db file.

  61040. **

  61041. ** This is only really safe if the file-system is such that any page 

  61042. ** writes made by earlier checkpointers were atomic operations, which 

  61043. ** is not always true. It is also possible that nBackfillAttempted

  61044. ** may be left set to a value larger than expected, if a wal frame

  61045. ** contains content that duplicate of an earlier version of the same

  61046. ** page.

  61047. **

  61048. ** SQLITE_OK is returned if successful, or an SQLite error code if an

  61049. ** error occurs. It is not an error if nBackfillAttempted cannot be

  61050. ** decreased at all.

  61051. */

  61052. SQLITE_PRIVATE int sqlite3WalSnapshotRecover(Wal *pWal){

  61053.   int rc;

  61054. 

  61055.   assert( pWal->readLock>=0 );

  61056.   rc = walLockExclusive(pWal, WAL_CKPT_LOCK, 1);

  61057.   if( rc==SQLITE_OK ){

  61058.     volatile WalCkptInfo *pInfo = walCkptInfo(pWal);

  61059.     int szPage = (int)pWal->szPage;

  61060.     i64 szDb;                   /* Size of db file in bytes */

  61061. 

  61062.     rc = sqlite3OsFileSize(pWal->pDbFd, &szDb);

  61063.     if( rc==SQLITE_OK ){

  61064.       void *pBuf1 = sqlite3_malloc(szPage);

  61065.       void *pBuf2 = sqlite3_malloc(szPage);

  61066.       if( pBuf1==0 || pBuf2==0 ){

  61067.         rc = SQLITE_NOMEM;

  61068.       }else{

  61069.         u32 i = pInfo->nBackfillAttempted;

  61070.         for(i=pInfo->nBackfillAttempted; i>pInfo->nBackfill; i--){

  61071.           WalHashLoc sLoc;          /* Hash table location */

  61072.           u32 pgno;                 /* Page number in db file */

  61073.           i64 iDbOff;               /* Offset of db file entry */

  61074.           i64 iWalOff;              /* Offset of wal file entry */

  61075. 

  61076.           rc = walHashGet(pWal, walFramePage(i), &sLoc);

  61077.           if( rc!=SQLITE_OK ) break;

  61078.           pgno = sLoc.aPgno[i-sLoc.iZero];

  61079.           iDbOff = (i64)(pgno-1) * szPage;

  61080. 

  61081.           if( iDbOff+szPage<=szDb ){

  61082.             iWalOff = walFrameOffset(i, szPage) + WAL_FRAME_HDRSIZE;

  61083.             rc = sqlite3OsRead(pWal->pWalFd, pBuf1, szPage, iWalOff);

  61084. 

  61085.             if( rc==SQLITE_OK ){

  61086.               rc = sqlite3OsRead(pWal->pDbFd, pBuf2, szPage, iDbOff);

  61087.             }

  61088. 

  61089.             if( rc!=SQLITE_OK || 0==memcmp(pBuf1, pBuf2, szPage) ){

  61090.               break;

  61091.             }

  61092.           }

  61093. 

  61094.           pInfo->nBackfillAttempted = i-1;

  61095.         }

  61096.       }

  61097. 

  61098.       sqlite3_free(pBuf1);

  61099.       sqlite3_free(pBuf2);

  61100.     }

  61101.     walUnlockExclusive(pWal, WAL_CKPT_LOCK, 1);

  61102.   }

  61103. 

  61104.   return rc;

  61105. }

  61106. #endif /* SQLITE_ENABLE_SNAPSHOT */

  61107. 

  61108. /*

  61109. ** Begin a read transaction on the database.

  61110. **

  61111. ** This routine used to be called sqlite3OpenSnapshot() and with good reason:

  61112. ** it takes a snapshot of the state of the WAL and wal-index for the current

  61113. ** instant in time.  The current thread will continue to use this snapshot.

  61114. ** Other threads might append new content to the WAL and wal-index but

  61115. ** that extra content is ignored by the current thread.

  61116. **

  61117. ** If the database contents have changes since the previous read

  61118. ** transaction, then *pChanged is set to 1 before returning.  The

  61119. ** Pager layer will use this to know that its cache is stale and

  61120. ** needs to be flushed.

  61121. */

  61122. SQLITE_PRIVATE int sqlite3WalBeginReadTransaction(Wal *pWal, int *pChanged){

  61123.   int rc;                         /* Return code */

  61124.   int cnt = 0;                    /* Number of TryBeginRead attempts */

  61125. 

  61126. #ifdef SQLITE_ENABLE_SNAPSHOT

  61127.   int bChanged = 0;

  61128.   WalIndexHdr *pSnapshot = pWal->pSnapshot;

  61129.   if( pSnapshot && memcmp(pSnapshot, &pWal->hdr, sizeof(WalIndexHdr))!=0 ){

  61130.     bChanged = 1;

  61131.   }

  61132. #endif

  61133. 

  61134.   do{

  61135.     rc = walTryBeginRead(pWal, pChanged, 0, ++cnt);

  61136.   }while( rc==WAL_RETRY );

  61137.   testcase( (rc&0xff)==SQLITE_BUSY );

  61138.   testcase( (rc&0xff)==SQLITE_IOERR );

  61139.   testcase( rc==SQLITE_PROTOCOL );

  61140.   testcase( rc==SQLITE_OK );

  61141. 

  61142. #ifdef SQLITE_ENABLE_SNAPSHOT

  61143.   if( rc==SQLITE_OK ){

  61144.     if( pSnapshot && memcmp(pSnapshot, &pWal->hdr, sizeof(WalIndexHdr))!=0 ){

  61145.       /* At this point the client has a lock on an aReadMark[] slot holding

  61146.       ** a value equal to or smaller than pSnapshot->mxFrame, but pWal->hdr

  61147.       ** is populated with the wal-index header corresponding to the head

  61148.       ** of the wal file. Verify that pSnapshot is still valid before

  61149.       ** continuing.  Reasons why pSnapshot might no longer be valid:

  61150.       **

  61151.       **    (1)  The WAL file has been reset since the snapshot was taken.

  61152.       **         In this case, the salt will have changed.

  61153.       **

  61154.       **    (2)  A checkpoint as been attempted that wrote frames past

  61155.       **         pSnapshot->mxFrame into the database file.  Note that the

  61156.       **         checkpoint need not have completed for this to cause problems.

  61157.       */

  61158.       volatile WalCkptInfo *pInfo = walCkptInfo(pWal);

  61159. 

  61160.       assert( pWal->readLock>0 || pWal->hdr.mxFrame==0 );

  61161.       assert( pInfo->aReadMark[pWal->readLock]<=pSnapshot->mxFrame );

  61162. 

  61163.       /* It is possible that there is a checkpointer thread running 

  61164.       ** concurrent with this code. If this is the case, it may be that the

  61165.       ** checkpointer has already determined that it will checkpoint 

  61166.       ** snapshot X, where X is later in the wal file than pSnapshot, but 

  61167.       ** has not yet set the pInfo->nBackfillAttempted variable to indicate 

  61168.       ** its intent. To avoid the race condition this leads to, ensure that

  61169.       ** there is no checkpointer process by taking a shared CKPT lock 

  61170.       ** before checking pInfo->nBackfillAttempted.  

  61171.       **

  61172.       ** TODO: Does the aReadMark[] lock prevent a checkpointer from doing

  61173.       **       this already?

  61174.       */

  61175.       rc = walLockShared(pWal, WAL_CKPT_LOCK);

  61176. 

  61177.       if( rc==SQLITE_OK ){

  61178.         /* Check that the wal file has not been wrapped. Assuming that it has

  61179.         ** not, also check that no checkpointer has attempted to checkpoint any

  61180.         ** frames beyond pSnapshot->mxFrame. If either of these conditions are

  61181.         ** true, return SQLITE_ERROR_SNAPSHOT. Otherwise, overwrite pWal->hdr

  61182.         ** with *pSnapshot and set *pChanged as appropriate for opening the

  61183.         ** snapshot.  */

  61184.         if( !memcmp(pSnapshot->aSalt, pWal->hdr.aSalt, sizeof(pWal->hdr.aSalt))

  61185.          && pSnapshot->mxFrame>=pInfo->nBackfillAttempted

  61186.         ){

  61187.           assert( pWal->readLock>0 );

  61188.           memcpy(&pWal->hdr, pSnapshot, sizeof(WalIndexHdr));

  61189.           *pChanged = bChanged;

  61190.         }else{

  61191.           rc = SQLITE_ERROR_SNAPSHOT;

  61192.         }

  61193. 

  61194.         /* Release the shared CKPT lock obtained above. */

  61195.         walUnlockShared(pWal, WAL_CKPT_LOCK);

  61196.         pWal->minFrame = 1;

  61197.       }

  61198. 

  61199. 

  61200.       if( rc!=SQLITE_OK ){

  61201.         sqlite3WalEndReadTransaction(pWal);

  61202.       }

  61203.     }

  61204.   }

  61205. #endif

  61206.   return rc;

  61207. }

  61208. 

  61209. /*

  61210. ** Finish with a read transaction.  All this does is release the

  61211. ** read-lock.

  61212. */

  61213. SQLITE_PRIVATE void sqlite3WalEndReadTransaction(Wal *pWal){

  61214.   sqlite3WalEndWriteTransaction(pWal);

  61215.   if( pWal->readLock>=0 ){

  61216.     walUnlockShared(pWal, WAL_READ_LOCK(pWal->readLock));

  61217.     pWal->readLock = -1;

  61218.   }

  61219. }

  61220. 

  61221. /*

  61222. ** Search the wal file for page pgno. If found, set *piRead to the frame that

  61223. ** contains the page. Otherwise, if pgno is not in the wal file, set *piRead

  61224. ** to zero.

  61225. **

  61226. ** Return SQLITE_OK if successful, or an error code if an error occurs. If an

  61227. ** error does occur, the final value of *piRead is undefined.

  61228. */

  61229. SQLITE_PRIVATE int sqlite3WalFindFrame(

  61230.   Wal *pWal,                      /* WAL handle */

  61231.   Pgno pgno,                      /* Database page number to read data for */

  61232.   u32 *piRead                     /* OUT: Frame number (or zero) */

  61233. ){

  61234.   u32 iRead = 0;                  /* If !=0, WAL frame to return data from */

  61235.   u32 iLast = pWal->hdr.mxFrame;  /* Last page in WAL for this reader */

  61236.   int iHash;                      /* Used to loop through N hash tables */

  61237.   int iMinHash;

  61238. 

  61239.   /* This routine is only be called from within a read transaction. */

  61240.   assert( pWal->readLock>=0 || pWal->lockError );

  61241. 

  61242.   /* If the "last page" field of the wal-index header snapshot is 0, then

  61243.   ** no data will be read from the wal under any circumstances. Return early

  61244.   ** in this case as an optimization.  Likewise, if pWal->readLock==0, 

  61245.   ** then the WAL is ignored by the reader so return early, as if the 

  61246.   ** WAL were empty.

  61247.   */

  61248.   if( iLast==0 || (pWal->readLock==0 && pWal->bShmUnreliable==0) ){

  61249.     *piRead = 0;

  61250.     return SQLITE_OK;

  61251.   }

  61252. 

  61253.   /* Search the hash table or tables for an entry matching page number

  61254.   ** pgno. Each iteration of the following for() loop searches one

  61255.   ** hash table (each hash table indexes up to HASHTABLE_NPAGE frames).

  61256.   **

  61257.   ** This code might run concurrently to the code in walIndexAppend()

  61258.   ** that adds entries to the wal-index (and possibly to this hash 

  61259.   ** table). This means the value just read from the hash 

  61260.   ** slot (aHash[iKey]) may have been added before or after the 

  61261.   ** current read transaction was opened. Values added after the

  61262.   ** read transaction was opened may have been written incorrectly -

  61263.   ** i.e. these slots may contain garbage data. However, we assume

  61264.   ** that any slots written before the current read transaction was

  61265.   ** opened remain unmodified.

  61266.   **

  61267.   ** For the reasons above, the if(...) condition featured in the inner

  61268.   ** loop of the following block is more stringent that would be required 

  61269.   ** if we had exclusive access to the hash-table:

  61270.   **

  61271.   **   (aPgno[iFrame]==pgno): 

  61272.   **     This condition filters out normal hash-table collisions.

  61273.   **

  61274.   **   (iFrame<=iLast): 

  61275.   **     This condition filters out entries that were added to the hash

  61276.   **     table after the current read-transaction had started.

  61277.   */

  61278.   iMinHash = walFramePage(pWal->minFrame);

  61279.   for(iHash=walFramePage(iLast); iHash>=iMinHash; iHash--){

  61280.     WalHashLoc sLoc;              /* Hash table location */

  61281.     int iKey;                     /* Hash slot index */

  61282.     int nCollide;                 /* Number of hash collisions remaining */

  61283.     int rc;                       /* Error code */

  61284. 

  61285.     rc = walHashGet(pWal, iHash, &sLoc);

  61286.     if( rc!=SQLITE_OK ){

  61287.       return rc;

  61288.     }

  61289.     nCollide = HASHTABLE_NSLOT;

  61290.     for(iKey=walHash(pgno); sLoc.aHash[iKey]; iKey=walNextHash(iKey)){

  61291.       u32 iH = sLoc.aHash[iKey];

  61292.       u32 iFrame = iH + sLoc.iZero;

  61293.       if( iFrame<=iLast && iFrame>=pWal->minFrame && sLoc.aPgno[iH]==pgno ){

  61294.         assert( iFrame>iRead || CORRUPT_DB );

  61295.         iRead = iFrame;

  61296.       }

  61297.       if( (nCollide--)==0 ){

  61298.         return SQLITE_CORRUPT_BKPT;

  61299.       }

  61300.     }

  61301.     if( iRead ) break;

  61302.   }

  61303. 

  61304. #ifdef SQLITE_ENABLE_EXPENSIVE_ASSERT

  61305.   /* If expensive assert() statements are available, do a linear search

  61306.   ** of the wal-index file content. Make sure the results agree with the

  61307.   ** result obtained using the hash indexes above.  */

  61308.   {

  61309.     u32 iRead2 = 0;

  61310.     u32 iTest;

  61311.     assert( pWal->bShmUnreliable || pWal->minFrame>0 );

  61312.     for(iTest=iLast; iTest>=pWal->minFrame && iTest>0; iTest--){

  61313.       if( walFramePgno(pWal, iTest)==pgno ){

  61314.         iRead2 = iTest;

  61315.         break;

  61316.       }

  61317.     }

  61318.     assert( iRead==iRead2 );

  61319.   }

  61320. #endif

  61321. 

  61322.   *piRead = iRead;

  61323.   return SQLITE_OK;

  61324. }

  61325. 

  61326. /*

  61327. ** Read the contents of frame iRead from the wal file into buffer pOut

  61328. ** (which is nOut bytes in size). Return SQLITE_OK if successful, or an

  61329. ** error code otherwise.

  61330. */

  61331. SQLITE_PRIVATE int sqlite3WalReadFrame(

  61332.   Wal *pWal,                      /* WAL handle */

  61333.   u32 iRead,                      /* Frame to read */

  61334.   int nOut,                       /* Size of buffer pOut in bytes */

  61335.   u8 *pOut                        /* Buffer to write page data to */

  61336. ){

  61337.   int sz;

  61338.   i64 iOffset;

  61339.   sz = pWal->hdr.szPage;

  61340.   sz = (sz&0xfe00) + ((sz&0x0001)<<16);

  61341.   testcase( sz<=32768 );

  61342.   testcase( sz>=65536 );

  61343.   iOffset = walFrameOffset(iRead, sz) + WAL_FRAME_HDRSIZE;

  61344.   /* testcase( IS_BIG_INT(iOffset) ); // requires a 4GiB WAL */

  61345.   return sqlite3OsRead(pWal->pWalFd, pOut, (nOut>sz ? sz : nOut), iOffset);

  61346. }

  61347. 

  61348. /* 

  61349. ** Return the size of the database in pages (or zero, if unknown).

  61350. */

  61351. SQLITE_PRIVATE Pgno sqlite3WalDbsize(Wal *pWal){

  61352.   if( pWal && ALWAYS(pWal->readLock>=0) ){

  61353.     return pWal->hdr.nPage;

  61354.   }

  61355.   return 0;

  61356. }

  61357. 

  61358. 

  61359. /* 

  61360. ** This function starts a write transaction on the WAL.

  61361. **

  61362. ** A read transaction must have already been started by a prior call

  61363. ** to sqlite3WalBeginReadTransaction().

  61364. **

  61365. ** If another thread or process has written into the database since

  61366. ** the read transaction was started, then it is not possible for this

  61367. ** thread to write as doing so would cause a fork.  So this routine

  61368. ** returns SQLITE_BUSY in that case and no write transaction is started.

  61369. **

  61370. ** There can only be a single writer active at a time.

  61371. */

  61372. SQLITE_PRIVATE int sqlite3WalBeginWriteTransaction(Wal *pWal){

  61373.   int rc;

  61374. 

  61375.   /* Cannot start a write transaction without first holding a read

  61376.   ** transaction. */

  61377.   assert( pWal->readLock>=0 );

  61378.   assert( pWal->writeLock==0 && pWal->iReCksum==0 );

  61379. 

  61380.   if( pWal->readOnly ){

  61381.     return SQLITE_READONLY;

  61382.   }

  61383. 

  61384.   /* Only one writer allowed at a time.  Get the write lock.  Return

  61385.   ** SQLITE_BUSY if unable.

  61386.   */

  61387.   rc = walLockExclusive(pWal, WAL_WRITE_LOCK, 1);

  61388.   if( rc ){

  61389.     return rc;

  61390.   }

  61391.   pWal->writeLock = 1;

  61392. 

  61393.   /* If another connection has written to the database file since the

  61394.   ** time the read transaction on this connection was started, then

  61395.   ** the write is disallowed.

  61396.   */

  61397.   if( memcmp(&pWal->hdr, (void *)walIndexHdr(pWal), sizeof(WalIndexHdr))!=0 ){

  61398.     walUnlockExclusive(pWal, WAL_WRITE_LOCK, 1);

  61399.     pWal->writeLock = 0;

  61400.     rc = SQLITE_BUSY_SNAPSHOT;

  61401.   }

  61402. 

  61403.   return rc;

  61404. }

  61405. 

  61406. /*

  61407. ** End a write transaction.  The commit has already been done.  This

  61408. ** routine merely releases the lock.

  61409. */

  61410. SQLITE_PRIVATE int sqlite3WalEndWriteTransaction(Wal *pWal){

  61411.   if( pWal->writeLock ){

  61412.     walUnlockExclusive(pWal, WAL_WRITE_LOCK, 1);

  61413.     pWal->writeLock = 0;

  61414.     pWal->iReCksum = 0;

  61415.     pWal->truncateOnCommit = 0;

  61416.   }

  61417.   return SQLITE_OK;

  61418. }

  61419. 

  61420. /*

  61421. ** If any data has been written (but not committed) to the log file, this

  61422. ** function moves the write-pointer back to the start of the transaction.

  61423. **

  61424. ** Additionally, the callback function is invoked for each frame written

  61425. ** to the WAL since the start of the transaction. If the callback returns

  61426. ** other than SQLITE_OK, it is not invoked again and the error code is

  61427. ** returned to the caller.

  61428. **

  61429. ** Otherwise, if the callback function does not return an error, this

  61430. ** function returns SQLITE_OK.

  61431. */

  61432. SQLITE_PRIVATE int sqlite3WalUndo(Wal *pWal, int (*xUndo)(void *, Pgno), void *pUndoCtx){

  61433.   int rc = SQLITE_OK;

  61434.   if( ALWAYS(pWal->writeLock) ){

  61435.     Pgno iMax = pWal->hdr.mxFrame;

  61436.     Pgno iFrame;

  61437.   

  61438.     /* Restore the clients cache of the wal-index header to the state it

  61439.     ** was in before the client began writing to the database. 

  61440.     */

  61441.     memcpy(&pWal->hdr, (void *)walIndexHdr(pWal), sizeof(WalIndexHdr));

  61442. 

  61443.     for(iFrame=pWal->hdr.mxFrame+1; 

  61444.         ALWAYS(rc==SQLITE_OK) && iFrame<=iMax; 

  61445.         iFrame++

  61446.     ){

  61447.       /* This call cannot fail. Unless the page for which the page number

  61448.       ** is passed as the second argument is (a) in the cache and 

  61449.       ** (b) has an outstanding reference, then xUndo is either a no-op

  61450.       ** (if (a) is false) or simply expels the page from the cache (if (b)

  61451.       ** is false).

  61452.       **

  61453.       ** If the upper layer is doing a rollback, it is guaranteed that there

  61454.       ** are no outstanding references to any page other than page 1. And

  61455.       ** page 1 is never written to the log until the transaction is

  61456.       ** committed. As a result, the call to xUndo may not fail.

  61457.       */

  61458.       assert( walFramePgno(pWal, iFrame)!=1 );

  61459.       rc = xUndo(pUndoCtx, walFramePgno(pWal, iFrame));

  61460.     }

  61461.     if( iMax!=pWal->hdr.mxFrame ) walCleanupHash(pWal);

  61462.   }

  61463.   return rc;

  61464. }

  61465. 

  61466. /* 

  61467. ** Argument aWalData must point to an array of WAL_SAVEPOINT_NDATA u32 

  61468. ** values. This function populates the array with values required to 

  61469. ** "rollback" the write position of the WAL handle back to the current 

  61470. ** point in the event of a savepoint rollback (via WalSavepointUndo()).

  61471. */

  61472. SQLITE_PRIVATE void sqlite3WalSavepoint(Wal *pWal, u32 *aWalData){

  61473.   assert( pWal->writeLock );

  61474.   aWalData[0] = pWal->hdr.mxFrame;

  61475.   aWalData[1] = pWal->hdr.aFrameCksum[0];

  61476.   aWalData[2] = pWal->hdr.aFrameCksum[1];

  61477.   aWalData[3] = pWal->nCkpt;

  61478. }

  61479. 

  61480. /* 

  61481. ** Move the write position of the WAL back to the point identified by

  61482. ** the values in the aWalData[] array. aWalData must point to an array

  61483. ** of WAL_SAVEPOINT_NDATA u32 values that has been previously populated

  61484. ** by a call to WalSavepoint().

  61485. */

  61486. SQLITE_PRIVATE int sqlite3WalSavepointUndo(Wal *pWal, u32 *aWalData){

  61487.   int rc = SQLITE_OK;

  61488. 

  61489.   assert( pWal->writeLock );

  61490.   assert( aWalData[3]!=pWal->nCkpt || aWalData[0]<=pWal->hdr.mxFrame );

  61491. 

  61492.   if( aWalData[3]!=pWal->nCkpt ){

  61493.     /* This savepoint was opened immediately after the write-transaction

  61494.     ** was started. Right after that, the writer decided to wrap around

  61495.     ** to the start of the log. Update the savepoint values to match.

  61496.     */

  61497.     aWalData[0] = 0;

  61498.     aWalData[3] = pWal->nCkpt;

  61499.   }

  61500. 

  61501.   if( aWalData[0]<pWal->hdr.mxFrame ){

  61502.     pWal->hdr.mxFrame = aWalData[0];

  61503.     pWal->hdr.aFrameCksum[0] = aWalData[1];

  61504.     pWal->hdr.aFrameCksum[1] = aWalData[2];

  61505.     walCleanupHash(pWal);

  61506.   }

  61507. 

  61508.   return rc;

  61509. }

  61510. 

  61511. /*

  61512. ** This function is called just before writing a set of frames to the log

  61513. ** file (see sqlite3WalFrames()). It checks to see if, instead of appending

  61514. ** to the current log file, it is possible to overwrite the start of the

  61515. ** existing log file with the new frames (i.e. "reset" the log). If so,

  61516. ** it sets pWal->hdr.mxFrame to 0. Otherwise, pWal->hdr.mxFrame is left

  61517. ** unchanged.

  61518. **

  61519. ** SQLITE_OK is returned if no error is encountered (regardless of whether

  61520. ** or not pWal->hdr.mxFrame is modified). An SQLite error code is returned

  61521. ** if an error occurs.

  61522. */

  61523. static int walRestartLog(Wal *pWal){

  61524.   int rc = SQLITE_OK;

  61525.   int cnt;

  61526. 

  61527.   if( pWal->readLock==0 ){

  61528.     volatile WalCkptInfo *pInfo = walCkptInfo(pWal);

  61529.     assert( pInfo->nBackfill==pWal->hdr.mxFrame );

  61530.     if( pInfo->nBackfill>0 ){

  61531.       u32 salt1;

  61532.       sqlite3_randomness(4, &salt1);

  61533.       rc = walLockExclusive(pWal, WAL_READ_LOCK(1), WAL_NREADER-1);

  61534.       if( rc==SQLITE_OK ){

  61535.         /* If all readers are using WAL_READ_LOCK(0) (in other words if no

  61536.         ** readers are currently using the WAL), then the transactions

  61537.         ** frames will overwrite the start of the existing log. Update the

  61538.         ** wal-index header to reflect this.

  61539.         **

  61540.         ** In theory it would be Ok to update the cache of the header only

  61541.         ** at this point. But updating the actual wal-index header is also

  61542.         ** safe and means there is no special case for sqlite3WalUndo()

  61543.         ** to handle if this transaction is rolled back.  */

  61544.         walRestartHdr(pWal, salt1);

  61545.         walUnlockExclusive(pWal, WAL_READ_LOCK(1), WAL_NREADER-1);

  61546.       }else if( rc!=SQLITE_BUSY ){

  61547.         return rc;

  61548.       }

  61549.     }

  61550.     walUnlockShared(pWal, WAL_READ_LOCK(0));

  61551.     pWal->readLock = -1;

  61552.     cnt = 0;

  61553.     do{

  61554.       int notUsed;

  61555.       rc = walTryBeginRead(pWal, &notUsed, 1, ++cnt);

  61556.     }while( rc==WAL_RETRY );

  61557.     assert( (rc&0xff)!=SQLITE_BUSY ); /* BUSY not possible when useWal==1 */

  61558.     testcase( (rc&0xff)==SQLITE_IOERR );

  61559.     testcase( rc==SQLITE_PROTOCOL );

  61560.     testcase( rc==SQLITE_OK );

  61561.   }

  61562.   return rc;

  61563. }

  61564. 

  61565. /*

  61566. ** Information about the current state of the WAL file and where

  61567. ** the next fsync should occur - passed from sqlite3WalFrames() into

  61568. ** walWriteToLog().

  61569. */

  61570. typedef struct WalWriter {

  61571.   Wal *pWal;                   /* The complete WAL information */

  61572.   sqlite3_file *pFd;           /* The WAL file to which we write */

  61573.   sqlite3_int64 iSyncPoint;    /* Fsync at this offset */

  61574.   int syncFlags;               /* Flags for the fsync */

  61575.   int szPage;                  /* Size of one page */

  61576. } WalWriter;

  61577. 

  61578. /*

  61579. ** Write iAmt bytes of content into the WAL file beginning at iOffset.

  61580. ** Do a sync when crossing the p->iSyncPoint boundary.

  61581. **

  61582. ** In other words, if iSyncPoint is in between iOffset and iOffset+iAmt,

  61583. ** first write the part before iSyncPoint, then sync, then write the

  61584. ** rest.

  61585. */

  61586. static int walWriteToLog(

  61587.   WalWriter *p,              /* WAL to write to */

  61588.   void *pContent,            /* Content to be written */

  61589.   int iAmt,                  /* Number of bytes to write */

  61590.   sqlite3_int64 iOffset      /* Start writing at this offset */

  61591. ){

  61592.   int rc;

  61593.   if( iOffset<p->iSyncPoint && iOffset+iAmt>=p->iSyncPoint ){

  61594.     int iFirstAmt = (int)(p->iSyncPoint - iOffset);

  61595.     rc = sqlite3OsWrite(p->pFd, pContent, iFirstAmt, iOffset);

  61596.     if( rc ) return rc;

  61597.     iOffset += iFirstAmt;

  61598.     iAmt -= iFirstAmt;

  61599.     pContent = (void*)(iFirstAmt + (char*)pContent);

  61600.     assert( WAL_SYNC_FLAGS(p->syncFlags)!=0 );

  61601.     rc = sqlite3OsSync(p->pFd, WAL_SYNC_FLAGS(p->syncFlags));

  61602.     if( iAmt==0 || rc ) return rc;

  61603.   }

  61604.   rc = sqlite3OsWrite(p->pFd, pContent, iAmt, iOffset);

  61605.   return rc;

  61606. }

  61607. 

  61608. /*

  61609. ** Write out a single frame of the WAL

  61610. */

  61611. static int walWriteOneFrame(

  61612.   WalWriter *p,               /* Where to write the frame */

  61613.   PgHdr *pPage,               /* The page of the frame to be written */

  61614.   int nTruncate,              /* The commit flag.  Usually 0.  >0 for commit */

  61615.   sqlite3_int64 iOffset       /* Byte offset at which to write */

  61616. ){

  61617.   int rc;                         /* Result code from subfunctions */

  61618.   void *pData;                    /* Data actually written */

  61619.   u8 aFrame[WAL_FRAME_HDRSIZE];   /* Buffer to assemble frame-header in */

  61620. #if defined(SQLITE_HAS_CODEC)

  61621.   if( (pData = sqlite3PagerCodec(pPage))==0 ) return SQLITE_NOMEM_BKPT;

  61622. #else

  61623.   pData = pPage->pData;

  61624. #endif

  61625.   walEncodeFrame(p->pWal, pPage->pgno, nTruncate, pData, aFrame);

  61626.   rc = walWriteToLog(p, aFrame, sizeof(aFrame), iOffset);

  61627.   if( rc ) return rc;

  61628.   /* Write the page data */

  61629.   rc = walWriteToLog(p, pData, p->szPage, iOffset+sizeof(aFrame));

  61630.   return rc;

  61631. }

  61632. 

  61633. /*

  61634. ** This function is called as part of committing a transaction within which

  61635. ** one or more frames have been overwritten. It updates the checksums for

  61636. ** all frames written to the wal file by the current transaction starting

  61637. ** with the earliest to have been overwritten.

  61638. **

  61639. ** SQLITE_OK is returned if successful, or an SQLite error code otherwise.

  61640. */

  61641. static int walRewriteChecksums(Wal *pWal, u32 iLast){

  61642.   const int szPage = pWal->szPage;/* Database page size */

  61643.   int rc = SQLITE_OK;             /* Return code */

  61644.   u8 *aBuf;                       /* Buffer to load data from wal file into */

  61645.   u8 aFrame[WAL_FRAME_HDRSIZE];   /* Buffer to assemble frame-headers in */

  61646.   u32 iRead;                      /* Next frame to read from wal file */

  61647.   i64 iCksumOff;

  61648. 

  61649.   aBuf = sqlite3_malloc(szPage + WAL_FRAME_HDRSIZE);

  61650.   if( aBuf==0 ) return SQLITE_NOMEM_BKPT;

  61651. 

  61652.   /* Find the checksum values to use as input for the recalculating the

  61653.   ** first checksum. If the first frame is frame 1 (implying that the current

  61654.   ** transaction restarted the wal file), these values must be read from the

  61655.   ** wal-file header. Otherwise, read them from the frame header of the

  61656.   ** previous frame.  */

  61657.   assert( pWal->iReCksum>0 );

  61658.   if( pWal->iReCksum==1 ){

  61659.     iCksumOff = 24;

  61660.   }else{

  61661.     iCksumOff = walFrameOffset(pWal->iReCksum-1, szPage) + 16;

  61662.   }

  61663.   rc = sqlite3OsRead(pWal->pWalFd, aBuf, sizeof(u32)*2, iCksumOff);

  61664.   pWal->hdr.aFrameCksum[0] = sqlite3Get4byte(aBuf);

  61665.   pWal->hdr.aFrameCksum[1] = sqlite3Get4byte(&aBuf[sizeof(u32)]);

  61666. 

  61667.   iRead = pWal->iReCksum;

  61668.   pWal->iReCksum = 0;

  61669.   for(; rc==SQLITE_OK && iRead<=iLast; iRead++){

  61670.     i64 iOff = walFrameOffset(iRead, szPage);

  61671.     rc = sqlite3OsRead(pWal->pWalFd, aBuf, szPage+WAL_FRAME_HDRSIZE, iOff);

  61672.     if( rc==SQLITE_OK ){

  61673.       u32 iPgno, nDbSize;

  61674.       iPgno = sqlite3Get4byte(aBuf);

  61675.       nDbSize = sqlite3Get4byte(&aBuf[4]);

  61676. 

  61677.       walEncodeFrame(pWal, iPgno, nDbSize, &aBuf[WAL_FRAME_HDRSIZE], aFrame);

  61678.       rc = sqlite3OsWrite(pWal->pWalFd, aFrame, sizeof(aFrame), iOff);

  61679.     }

  61680.   }

  61681. 

  61682.   sqlite3_free(aBuf);

  61683.   return rc;

  61684. }

  61685. 

  61686. /* 

  61687. ** Write a set of frames to the log. The caller must hold the write-lock

  61688. ** on the log file (obtained using sqlite3WalBeginWriteTransaction()).

  61689. */

  61690. SQLITE_PRIVATE int sqlite3WalFrames(

  61691.   Wal *pWal,                      /* Wal handle to write to */

  61692.   int szPage,                     /* Database page-size in bytes */

  61693.   PgHdr *pList,                   /* List of dirty pages to write */

  61694.   Pgno nTruncate,                 /* Database size after this commit */

  61695.   int isCommit,                   /* True if this is a commit */

  61696.   int sync_flags                  /* Flags to pass to OsSync() (or 0) */

  61697. ){

  61698.   int rc;                         /* Used to catch return codes */

  61699.   u32 iFrame;                     /* Next frame address */

  61700.   PgHdr *p;                       /* Iterator to run through pList with. */

  61701.   PgHdr *pLast = 0;               /* Last frame in list */

  61702.   int nExtra = 0;                 /* Number of extra copies of last page */

  61703.   int szFrame;                    /* The size of a single frame */

  61704.   i64 iOffset;                    /* Next byte to write in WAL file */

  61705.   WalWriter w;                    /* The writer */

  61706.   u32 iFirst = 0;                 /* First frame that may be overwritten */

  61707.   WalIndexHdr *pLive;             /* Pointer to shared header */

  61708. 

  61709.   assert( pList );

  61710.   assert( pWal->writeLock );

  61711. 

  61712.   /* If this frame set completes a transaction, then nTruncate>0.  If

  61713.   ** nTruncate==0 then this frame set does not complete the transaction. */

  61714.   assert( (isCommit!=0)==(nTruncate!=0) );

  61715. 

  61716. #if defined(SQLITE_TEST) && defined(SQLITE_DEBUG)

  61717.   { int cnt; for(cnt=0, p=pList; p; p=p->pDirty, cnt++){}

  61718.     WALTRACE(("WAL%p: frame write begin. %d frames. mxFrame=%d. %s\n",

  61719.               pWal, cnt, pWal->hdr.mxFrame, isCommit ? "Commit" : "Spill"));

  61720.   }

  61721. #endif

  61722. 

  61723.   pLive = (WalIndexHdr*)walIndexHdr(pWal);

  61724.   if( memcmp(&pWal->hdr, (void *)pLive, sizeof(WalIndexHdr))!=0 ){

  61725.     iFirst = pLive->mxFrame+1;

  61726.   }

  61727. 

  61728.   /* See if it is possible to write these frames into the start of the

  61729.   ** log file, instead of appending to it at pWal->hdr.mxFrame.

  61730.   */

  61731.   if( SQLITE_OK!=(rc = walRestartLog(pWal)) ){

  61732.     return rc;

  61733.   }

  61734. 

  61735.   /* If this is the first frame written into the log, write the WAL

  61736.   ** header to the start of the WAL file. See comments at the top of

  61737.   ** this source file for a description of the WAL header format.

  61738.   */

  61739.   iFrame = pWal->hdr.mxFrame;

  61740.   if( iFrame==0 ){

  61741.     u8 aWalHdr[WAL_HDRSIZE];      /* Buffer to assemble wal-header in */

  61742.     u32 aCksum[2];                /* Checksum for wal-header */

  61743. 

  61744.     sqlite3Put4byte(&aWalHdr[0], (WAL_MAGIC | SQLITE_BIGENDIAN));

  61745.     sqlite3Put4byte(&aWalHdr[4], WAL_MAX_VERSION);

  61746.     sqlite3Put4byte(&aWalHdr[8], szPage);

  61747.     sqlite3Put4byte(&aWalHdr[12], pWal->nCkpt);

  61748.     if( pWal->nCkpt==0 ) sqlite3_randomness(8, pWal->hdr.aSalt);

  61749.     memcpy(&aWalHdr[16], pWal->hdr.aSalt, 8);

  61750.     walChecksumBytes(1, aWalHdr, WAL_HDRSIZE-2*4, 0, aCksum);

  61751.     sqlite3Put4byte(&aWalHdr[24], aCksum[0]);

  61752.     sqlite3Put4byte(&aWalHdr[28], aCksum[1]);

  61753.     

  61754.     pWal->szPage = szPage;

  61755.     pWal->hdr.bigEndCksum = SQLITE_BIGENDIAN;

  61756.     pWal->hdr.aFrameCksum[0] = aCksum[0];

  61757.     pWal->hdr.aFrameCksum[1] = aCksum[1];

  61758.     pWal->truncateOnCommit = 1;

  61759. 

  61760.     rc = sqlite3OsWrite(pWal->pWalFd, aWalHdr, sizeof(aWalHdr), 0);

  61761.     WALTRACE(("WAL%p: wal-header write %s\n", pWal, rc ? "failed" : "ok"));

  61762.     if( rc!=SQLITE_OK ){

  61763.       return rc;

  61764.     }

  61765. 

  61766.     /* Sync the header (unless SQLITE_IOCAP_SEQUENTIAL is true or unless

  61767.     ** all syncing is turned off by PRAGMA synchronous=OFF).  Otherwise

  61768.     ** an out-of-order write following a WAL restart could result in

  61769.     ** database corruption.  See the ticket:

  61770.     **

  61771.     **     https://sqlite.org/src/info/ff5be73dee

  61772.     */

  61773.     if( pWal->syncHeader ){

  61774.       rc = sqlite3OsSync(pWal->pWalFd, CKPT_SYNC_FLAGS(sync_flags));

  61775.       if( rc ) return rc;

  61776.     }

  61777.   }

  61778.   assert( (int)pWal->szPage==szPage );

  61779. 

  61780.   /* Setup information needed to write frames into the WAL */

  61781.   w.pWal = pWal;

  61782.   w.pFd = pWal->pWalFd;

  61783.   w.iSyncPoint = 0;

  61784.   w.syncFlags = sync_flags;

  61785.   w.szPage = szPage;

  61786.   iOffset = walFrameOffset(iFrame+1, szPage);

  61787.   szFrame = szPage + WAL_FRAME_HDRSIZE;

  61788. 

  61789.   /* Write all frames into the log file exactly once */

  61790.   for(p=pList; p; p=p->pDirty){

  61791.     int nDbSize;   /* 0 normally.  Positive == commit flag */

  61792. 

  61793.     /* Check if this page has already been written into the wal file by

  61794.     ** the current transaction. If so, overwrite the existing frame and

  61795.     ** set Wal.writeLock to WAL_WRITELOCK_RECKSUM - indicating that 

  61796.     ** checksums must be recomputed when the transaction is committed.  */

  61797.     if( iFirst && (p->pDirty || isCommit==0) ){

  61798.       u32 iWrite = 0;

  61799.       VVA_ONLY(rc =) sqlite3WalFindFrame(pWal, p->pgno, &iWrite);

  61800.       assert( rc==SQLITE_OK || iWrite==0 );

  61801.       if( iWrite>=iFirst ){

  61802.         i64 iOff = walFrameOffset(iWrite, szPage) + WAL_FRAME_HDRSIZE;

  61803.         void *pData;

  61804.         if( pWal->iReCksum==0 || iWrite<pWal->iReCksum ){

  61805.           pWal->iReCksum = iWrite;

  61806.         }

  61807. #if defined(SQLITE_HAS_CODEC)

  61808.         if( (pData = sqlite3PagerCodec(p))==0 ) return SQLITE_NOMEM;

  61809. #else

  61810.         pData = p->pData;

  61811. #endif

  61812.         rc = sqlite3OsWrite(pWal->pWalFd, pData, szPage, iOff);

  61813.         if( rc ) return rc;

  61814.         p->flags &= ~PGHDR_WAL_APPEND;

  61815.         continue;

  61816.       }

  61817.     }

  61818. 

  61819.     iFrame++;

  61820.     assert( iOffset==walFrameOffset(iFrame, szPage) );

  61821.     nDbSize = (isCommit && p->pDirty==0) ? nTruncate : 0;

  61822.     rc = walWriteOneFrame(&w, p, nDbSize, iOffset);

  61823.     if( rc ) return rc;

  61824.     pLast = p;

  61825.     iOffset += szFrame;

  61826.     p->flags |= PGHDR_WAL_APPEND;

  61827.   }

  61828. 

  61829.   /* Recalculate checksums within the wal file if required. */

  61830.   if( isCommit && pWal->iReCksum ){

  61831.     rc = walRewriteChecksums(pWal, iFrame);

  61832.     if( rc ) return rc;

  61833.   }

  61834. 

  61835.   /* If this is the end of a transaction, then we might need to pad

  61836.   ** the transaction and/or sync the WAL file.

  61837.   **

  61838.   ** Padding and syncing only occur if this set of frames complete a

  61839.   ** transaction and if PRAGMA synchronous=FULL.  If synchronous==NORMAL

  61840.   ** or synchronous==OFF, then no padding or syncing are needed.

  61841.   **

  61842.   ** If SQLITE_IOCAP_POWERSAFE_OVERWRITE is defined, then padding is not

  61843.   ** needed and only the sync is done.  If padding is needed, then the

  61844.   ** final frame is repeated (with its commit mark) until the next sector

  61845.   ** boundary is crossed.  Only the part of the WAL prior to the last

  61846.   ** sector boundary is synced; the part of the last frame that extends

  61847.   ** past the sector boundary is written after the sync.

  61848.   */

  61849.   if( isCommit && WAL_SYNC_FLAGS(sync_flags)!=0 ){

  61850.     int bSync = 1;

  61851.     if( pWal->padToSectorBoundary ){

  61852.       int sectorSize = sqlite3SectorSize(pWal->pWalFd);

  61853.       w.iSyncPoint = ((iOffset+sectorSize-1)/sectorSize)*sectorSize;

  61854.       bSync = (w.iSyncPoint==iOffset);

  61855.       testcase( bSync );

  61856.       while( iOffset<w.iSyncPoint ){

  61857.         rc = walWriteOneFrame(&w, pLast, nTruncate, iOffset);

  61858.         if( rc ) return rc;

  61859.         iOffset += szFrame;

  61860.         nExtra++;

  61861.       }

  61862.     }

  61863.     if( bSync ){

  61864.       assert( rc==SQLITE_OK );

  61865.       rc = sqlite3OsSync(w.pFd, WAL_SYNC_FLAGS(sync_flags));

  61866.     }

  61867.   }

  61868. 

  61869.   /* If this frame set completes the first transaction in the WAL and

  61870.   ** if PRAGMA journal_size_limit is set, then truncate the WAL to the

  61871.   ** journal size limit, if possible.

  61872.   */

  61873.   if( isCommit && pWal->truncateOnCommit && pWal->mxWalSize>=0 ){

  61874.     i64 sz = pWal->mxWalSize;

  61875.     if( walFrameOffset(iFrame+nExtra+1, szPage)>pWal->mxWalSize ){

  61876.       sz = walFrameOffset(iFrame+nExtra+1, szPage);

  61877.     }

  61878.     walLimitSize(pWal, sz);

  61879.     pWal->truncateOnCommit = 0;

  61880.   }

  61881. 

  61882.   /* Append data to the wal-index. It is not necessary to lock the 

  61883.   ** wal-index to do this as the SQLITE_SHM_WRITE lock held on the wal-index

  61884.   ** guarantees that there are no other writers, and no data that may

  61885.   ** be in use by existing readers is being overwritten.

  61886.   */

  61887.   iFrame = pWal->hdr.mxFrame;

  61888.   for(p=pList; p && rc==SQLITE_OK; p=p->pDirty){

  61889.     if( (p->flags & PGHDR_WAL_APPEND)==0 ) continue;

  61890.     iFrame++;

  61891.     rc = walIndexAppend(pWal, iFrame, p->pgno);

  61892.   }

  61893.   while( rc==SQLITE_OK && nExtra>0 ){

  61894.     iFrame++;

  61895.     nExtra--;

  61896.     rc = walIndexAppend(pWal, iFrame, pLast->pgno);

  61897.   }

  61898. 

  61899.   if( rc==SQLITE_OK ){

  61900.     /* Update the private copy of the header. */

  61901.     pWal->hdr.szPage = (u16)((szPage&0xff00) | (szPage>>16));

  61902.     testcase( szPage<=32768 );

  61903.     testcase( szPage>=65536 );

  61904.     pWal->hdr.mxFrame = iFrame;

  61905.     if( isCommit ){

  61906.       pWal->hdr.iChange++;

  61907.       pWal->hdr.nPage = nTruncate;

  61908.     }

  61909.     /* If this is a commit, update the wal-index header too. */

  61910.     if( isCommit ){

  61911.       walIndexWriteHdr(pWal);

  61912.       pWal->iCallback = iFrame;

  61913.     }

  61914.   }

  61915. 

  61916.   WALTRACE(("WAL%p: frame write %s\n", pWal, rc ? "failed" : "ok"));

  61917.   return rc;

  61918. }

  61919. 

  61920. /* 

  61921. ** This routine is called to implement sqlite3_wal_checkpoint() and

  61922. ** related interfaces.

  61923. **

  61924. ** Obtain a CHECKPOINT lock and then backfill as much information as

  61925. ** we can from WAL into the database.

  61926. **

  61927. ** If parameter xBusy is not NULL, it is a pointer to a busy-handler

  61928. ** callback. In this case this function runs a blocking checkpoint.

  61929. */

  61930. SQLITE_PRIVATE int sqlite3WalCheckpoint(

  61931.   Wal *pWal,                      /* Wal connection */

  61932.   sqlite3 *db,                    /* Check this handle's interrupt flag */

  61933.   int eMode,                      /* PASSIVE, FULL, RESTART, or TRUNCATE */

  61934.   int (*xBusy)(void*),            /* Function to call when busy */

  61935.   void *pBusyArg,                 /* Context argument for xBusyHandler */

  61936.   int sync_flags,                 /* Flags to sync db file with (or 0) */

  61937.   int nBuf,                       /* Size of temporary buffer */

  61938.   u8 *zBuf,                       /* Temporary buffer to use */

  61939.   int *pnLog,                     /* OUT: Number of frames in WAL */

  61940.   int *pnCkpt                     /* OUT: Number of backfilled frames in WAL */

  61941. ){

  61942.   int rc;                         /* Return code */

  61943.   int isChanged = 0;              /* True if a new wal-index header is loaded */

  61944.   int eMode2 = eMode;             /* Mode to pass to walCheckpoint() */

  61945.   int (*xBusy2)(void*) = xBusy;   /* Busy handler for eMode2 */

  61946. 

  61947.   assert( pWal->ckptLock==0 );

  61948.   assert( pWal->writeLock==0 );

  61949. 

  61950.   /* EVIDENCE-OF: R-62920-47450 The busy-handler callback is never invoked

  61951.   ** in the SQLITE_CHECKPOINT_PASSIVE mode. */

  61952.   assert( eMode!=SQLITE_CHECKPOINT_PASSIVE || xBusy==0 );

  61953. 

  61954.   if( pWal->readOnly ) return SQLITE_READONLY;

  61955.   WALTRACE(("WAL%p: checkpoint begins\n", pWal));

  61956. 

  61957.   /* IMPLEMENTATION-OF: R-62028-47212 All calls obtain an exclusive 

  61958.   ** "checkpoint" lock on the database file. */

  61959.   rc = walLockExclusive(pWal, WAL_CKPT_LOCK, 1);

  61960.   if( rc ){

  61961.     /* EVIDENCE-OF: R-10421-19736 If any other process is running a

  61962.     ** checkpoint operation at the same time, the lock cannot be obtained and

  61963.     ** SQLITE_BUSY is returned.

  61964.     ** EVIDENCE-OF: R-53820-33897 Even if there is a busy-handler configured,

  61965.     ** it will not be invoked in this case.

  61966.     */

  61967.     testcase( rc==SQLITE_BUSY );

  61968.     testcase( xBusy!=0 );

  61969.     return rc;

  61970.   }

  61971.   pWal->ckptLock = 1;

  61972. 

  61973.   /* IMPLEMENTATION-OF: R-59782-36818 The SQLITE_CHECKPOINT_FULL, RESTART and

  61974.   ** TRUNCATE modes also obtain the exclusive "writer" lock on the database

  61975.   ** file.

  61976.   **

  61977.   ** EVIDENCE-OF: R-60642-04082 If the writer lock cannot be obtained

  61978.   ** immediately, and a busy-handler is configured, it is invoked and the

  61979.   ** writer lock retried until either the busy-handler returns 0 or the

  61980.   ** lock is successfully obtained.

  61981.   */

  61982.   if( eMode!=SQLITE_CHECKPOINT_PASSIVE ){

  61983.     rc = walBusyLock(pWal, xBusy, pBusyArg, WAL_WRITE_LOCK, 1);

  61984.     if( rc==SQLITE_OK ){

  61985.       pWal->writeLock = 1;

  61986.     }else if( rc==SQLITE_BUSY ){

  61987.       eMode2 = SQLITE_CHECKPOINT_PASSIVE;

  61988.       xBusy2 = 0;

  61989.       rc = SQLITE_OK;

  61990.     }

  61991.   }

  61992. 

  61993.   /* Read the wal-index header. */

  61994.   if( rc==SQLITE_OK ){

  61995.     rc = walIndexReadHdr(pWal, &isChanged);

  61996.     if( isChanged && pWal->pDbFd->pMethods->iVersion>=3 ){

  61997.       sqlite3OsUnfetch(pWal->pDbFd, 0, 0);

  61998.     }

  61999.   }

  62000. 

  62001.   /* Copy data from the log to the database file. */

  62002.   if( rc==SQLITE_OK ){

  62003. 

  62004.     if( pWal->hdr.mxFrame && walPagesize(pWal)!=nBuf ){

  62005.       rc = SQLITE_CORRUPT_BKPT;

  62006.     }else{

  62007.       rc = walCheckpoint(pWal, db, eMode2, xBusy2, pBusyArg, sync_flags, zBuf);

  62008.     }

  62009. 

  62010.     /* If no error occurred, set the output variables. */

  62011.     if( rc==SQLITE_OK || rc==SQLITE_BUSY ){

  62012.       if( pnLog ) *pnLog = (int)pWal->hdr.mxFrame;

  62013.       if( pnCkpt ) *pnCkpt = (int)(walCkptInfo(pWal)->nBackfill);

  62014.     }

  62015.   }

  62016. 

  62017.   if( isChanged ){

  62018.     /* If a new wal-index header was loaded before the checkpoint was 

  62019.     ** performed, then the pager-cache associated with pWal is now

  62020.     ** out of date. So zero the cached wal-index header to ensure that

  62021.     ** next time the pager opens a snapshot on this database it knows that

  62022.     ** the cache needs to be reset.

  62023.     */

  62024.     memset(&pWal->hdr, 0, sizeof(WalIndexHdr));

  62025.   }

  62026. 

  62027.   /* Release the locks. */

  62028.   sqlite3WalEndWriteTransaction(pWal);

  62029.   walUnlockExclusive(pWal, WAL_CKPT_LOCK, 1);

  62030.   pWal->ckptLock = 0;

  62031.   WALTRACE(("WAL%p: checkpoint %s\n", pWal, rc ? "failed" : "ok"));

  62032.   return (rc==SQLITE_OK && eMode!=eMode2 ? SQLITE_BUSY : rc);

  62033. }

  62034. 

  62035. /* Return the value to pass to a sqlite3_wal_hook callback, the

  62036. ** number of frames in the WAL at the point of the last commit since

  62037. ** sqlite3WalCallback() was called.  If no commits have occurred since

  62038. ** the last call, then return 0.

  62039. */

  62040. SQLITE_PRIVATE int sqlite3WalCallback(Wal *pWal){

  62041.   u32 ret = 0;

  62042.   if( pWal ){

  62043.     ret = pWal->iCallback;

  62044.     pWal->iCallback = 0;

  62045.   }

  62046.   return (int)ret;

  62047. }

  62048. 

  62049. /*

  62050. ** This function is called to change the WAL subsystem into or out

  62051. ** of locking_mode=EXCLUSIVE.

  62052. **

  62053. ** If op is zero, then attempt to change from locking_mode=EXCLUSIVE

  62054. ** into locking_mode=NORMAL.  This means that we must acquire a lock

  62055. ** on the pWal->readLock byte.  If the WAL is already in locking_mode=NORMAL

  62056. ** or if the acquisition of the lock fails, then return 0.  If the

  62057. ** transition out of exclusive-mode is successful, return 1.  This

  62058. ** operation must occur while the pager is still holding the exclusive

  62059. ** lock on the main database file.

  62060. **

  62061. ** If op is one, then change from locking_mode=NORMAL into 

  62062. ** locking_mode=EXCLUSIVE.  This means that the pWal->readLock must

  62063. ** be released.  Return 1 if the transition is made and 0 if the

  62064. ** WAL is already in exclusive-locking mode - meaning that this

  62065. ** routine is a no-op.  The pager must already hold the exclusive lock

  62066. ** on the main database file before invoking this operation.

  62067. **

  62068. ** If op is negative, then do a dry-run of the op==1 case but do

  62069. ** not actually change anything. The pager uses this to see if it

  62070. ** should acquire the database exclusive lock prior to invoking

  62071. ** the op==1 case.

  62072. */

  62073. SQLITE_PRIVATE int sqlite3WalExclusiveMode(Wal *pWal, int op){

  62074.   int rc;

  62075.   assert( pWal->writeLock==0 );

  62076.   assert( pWal->exclusiveMode!=WAL_HEAPMEMORY_MODE || op==-1 );

  62077. 

  62078.   /* pWal->readLock is usually set, but might be -1 if there was a 

  62079.   ** prior error while attempting to acquire are read-lock. This cannot 

  62080.   ** happen if the connection is actually in exclusive mode (as no xShmLock

  62081.   ** locks are taken in this case). Nor should the pager attempt to

  62082.   ** upgrade to exclusive-mode following such an error.

  62083.   */

  62084.   assert( pWal->readLock>=0 || pWal->lockError );

  62085.   assert( pWal->readLock>=0 || (op<=0 && pWal->exclusiveMode==0) );

  62086. 

  62087.   if( op==0 ){

  62088.     if( pWal->exclusiveMode!=WAL_NORMAL_MODE ){

  62089.       pWal->exclusiveMode = WAL_NORMAL_MODE;

  62090.       if( walLockShared(pWal, WAL_READ_LOCK(pWal->readLock))!=SQLITE_OK ){

  62091.         pWal->exclusiveMode = WAL_EXCLUSIVE_MODE;

  62092.       }

  62093.       rc = pWal->exclusiveMode==WAL_NORMAL_MODE;

  62094.     }else{

  62095.       /* Already in locking_mode=NORMAL */

  62096.       rc = 0;

  62097.     }

  62098.   }else if( op>0 ){

  62099.     assert( pWal->exclusiveMode==WAL_NORMAL_MODE );

  62100.     assert( pWal->readLock>=0 );

  62101.     walUnlockShared(pWal, WAL_READ_LOCK(pWal->readLock));

  62102.     pWal->exclusiveMode = WAL_EXCLUSIVE_MODE;

  62103.     rc = 1;

  62104.   }else{

  62105.     rc = pWal->exclusiveMode==WAL_NORMAL_MODE;

  62106.   }

  62107.   return rc;

  62108. }

  62109. 

  62110. /* 

  62111. ** Return true if the argument is non-NULL and the WAL module is using

  62112. ** heap-memory for the wal-index. Otherwise, if the argument is NULL or the

  62113. ** WAL module is using shared-memory, return false. 

  62114. */

  62115. SQLITE_PRIVATE int sqlite3WalHeapMemory(Wal *pWal){

  62116.   return (pWal && pWal->exclusiveMode==WAL_HEAPMEMORY_MODE );

  62117. }

  62118. 

  62119. #ifdef SQLITE_ENABLE_SNAPSHOT

  62120. /* Create a snapshot object.  The content of a snapshot is opaque to

  62121. ** every other subsystem, so the WAL module can put whatever it needs

  62122. ** in the object.

  62123. */

  62124. SQLITE_PRIVATE int sqlite3WalSnapshotGet(Wal *pWal, sqlite3_snapshot **ppSnapshot){

  62125.   int rc = SQLITE_OK;

  62126.   WalIndexHdr *pRet;

  62127.   static const u32 aZero[4] = { 0, 0, 0, 0 };

  62128. 

  62129.   assert( pWal->readLock>=0 && pWal->writeLock==0 );

  62130. 

  62131.   if( memcmp(&pWal->hdr.aFrameCksum[0],aZero,16)==0 ){

  62132.     *ppSnapshot = 0;

  62133.     return SQLITE_ERROR;

  62134.   }

  62135.   pRet = (WalIndexHdr*)sqlite3_malloc(sizeof(WalIndexHdr));

  62136.   if( pRet==0 ){

  62137.     rc = SQLITE_NOMEM_BKPT;

  62138.   }else{

  62139.     memcpy(pRet, &pWal->hdr, sizeof(WalIndexHdr));

  62140.     *ppSnapshot = (sqlite3_snapshot*)pRet;

  62141.   }

  62142. 

  62143.   return rc;

  62144. }

  62145. 

  62146. /* Try to open on pSnapshot when the next read-transaction starts

  62147. */

  62148. SQLITE_PRIVATE void sqlite3WalSnapshotOpen(Wal *pWal, sqlite3_snapshot *pSnapshot){

  62149.   pWal->pSnapshot = (WalIndexHdr*)pSnapshot;

  62150. }

  62151. 

  62152. /* 

  62153. ** Return a +ve value if snapshot p1 is newer than p2. A -ve value if

  62154. ** p1 is older than p2 and zero if p1 and p2 are the same snapshot.

  62155. */

  62156. SQLITE_API int sqlite3_snapshot_cmp(sqlite3_snapshot *p1, sqlite3_snapshot *p2){

  62157.   WalIndexHdr *pHdr1 = (WalIndexHdr*)p1;

  62158.   WalIndexHdr *pHdr2 = (WalIndexHdr*)p2;

  62159. 

  62160.   /* aSalt[0] is a copy of the value stored in the wal file header. It

  62161.   ** is incremented each time the wal file is restarted.  */

  62162.   if( pHdr1->aSalt[0]<pHdr2->aSalt[0] ) return -1;

  62163.   if( pHdr1->aSalt[0]>pHdr2->aSalt[0] ) return +1;

  62164.   if( pHdr1->mxFrame<pHdr2->mxFrame ) return -1;

  62165.   if( pHdr1->mxFrame>pHdr2->mxFrame ) return +1;

  62166.   return 0;

  62167. }

  62168. 

  62169. /*

  62170. ** The caller currently has a read transaction open on the database.

  62171. ** This function takes a SHARED lock on the CHECKPOINTER slot and then

  62172. ** checks if the snapshot passed as the second argument is still 

  62173. ** available. If so, SQLITE_OK is returned.

  62174. **

  62175. ** If the snapshot is not available, SQLITE_ERROR is returned. Or, if

  62176. ** the CHECKPOINTER lock cannot be obtained, SQLITE_BUSY. If any error

  62177. ** occurs (any value other than SQLITE_OK is returned), the CHECKPOINTER

  62178. ** lock is released before returning.

  62179. */

  62180. SQLITE_PRIVATE int sqlite3WalSnapshotCheck(Wal *pWal, sqlite3_snapshot *pSnapshot){

  62181.   int rc;

  62182.   rc = walLockShared(pWal, WAL_CKPT_LOCK);

  62183.   if( rc==SQLITE_OK ){

  62184.     WalIndexHdr *pNew = (WalIndexHdr*)pSnapshot;

  62185.     if( memcmp(pNew->aSalt, pWal->hdr.aSalt, sizeof(pWal->hdr.aSalt))

  62186.      || pNew->mxFrame<walCkptInfo(pWal)->nBackfillAttempted

  62187.     ){

  62188.       rc = SQLITE_ERROR_SNAPSHOT;

  62189.       walUnlockShared(pWal, WAL_CKPT_LOCK);

  62190.     }

  62191.   }

  62192.   return rc;

  62193. }

  62194. 

  62195. /*

  62196. ** Release a lock obtained by an earlier successful call to

  62197. ** sqlite3WalSnapshotCheck().

  62198. */

  62199. SQLITE_PRIVATE void sqlite3WalSnapshotUnlock(Wal *pWal){

  62200.   assert( pWal );

  62201.   walUnlockShared(pWal, WAL_CKPT_LOCK);

  62202. }

  62203. 

  62204. 

  62205. #endif /* SQLITE_ENABLE_SNAPSHOT */

  62206. 

  62207. #ifdef SQLITE_ENABLE_ZIPVFS

  62208. /*

  62209. ** If the argument is not NULL, it points to a Wal object that holds a

  62210. ** read-lock. This function returns the database page-size if it is known,

  62211. ** or zero if it is not (or if pWal is NULL).

  62212. */

  62213. SQLITE_PRIVATE int sqlite3WalFramesize(Wal *pWal){

  62214.   assert( pWal==0 || pWal->readLock>=0 );

  62215.   return (pWal ? pWal->szPage : 0);

  62216. }

  62217. #endif

  62218. 

  62219. /* Return the sqlite3_file object for the WAL file

  62220. */

  62221. SQLITE_PRIVATE sqlite3_file *sqlite3WalFile(Wal *pWal){

  62222.   return pWal->pWalFd;

  62223. }

  62224. 

  62225. #endif /* #ifndef SQLITE_OMIT_WAL */

  62226. 

  62227. /************** End of wal.c *************************************************/

  62228. /************** Begin file btmutex.c *****************************************/

  62229. /*

  62230. ** 2007 August 27

  62231. **

  62232. ** The author disclaims copyright to this source code.  In place of

  62233. ** a legal notice, here is a blessing:

  62234. **

  62235. **    May you do good and not evil.

  62236. **    May you find forgiveness for yourself and forgive others.

  62237. **    May you share freely, never taking more than you give.

  62238. **

  62239. *************************************************************************

  62240. **

  62241. ** This file contains code used to implement mutexes on Btree objects.

  62242. ** This code really belongs in btree.c.  But btree.c is getting too

  62243. ** big and we want to break it down some.  This packaged seemed like

  62244. ** a good breakout.

  62245. */

  62246. /************** Include btreeInt.h in the middle of btmutex.c ****************/

  62247. /************** Begin file btreeInt.h ****************************************/

  62248. /*

  62249. ** 2004 April 6

  62250. **

  62251. ** The author disclaims copyright to this source code.  In place of

  62252. ** a legal notice, here is a blessing:

  62253. **

  62254. **    May you do good and not evil.

  62255. **    May you find forgiveness for yourself and forgive others.

  62256. **    May you share freely, never taking more than you give.

  62257. **

  62258. *************************************************************************

  62259. ** This file implements an external (disk-based) database using BTrees.

  62260. ** For a detailed discussion of BTrees, refer to

  62261. **

  62262. **     Donald E. Knuth, THE ART OF COMPUTER PROGRAMMING, Volume 3:

  62263. **     "Sorting And Searching", pages 473-480. Addison-Wesley

  62264. **     Publishing Company, Reading, Massachusetts.

  62265. **

  62266. ** The basic idea is that each page of the file contains N database

  62267. ** entries and N+1 pointers to subpages.

  62268. **

  62269. **   ----------------------------------------------------------------

  62270. **   |  Ptr(0) | Key(0) | Ptr(1) | Key(1) | ... | Key(N-1) | Ptr(N) |

  62271. **   ----------------------------------------------------------------

  62272. **

  62273. ** All of the keys on the page that Ptr(0) points to have values less

  62274. ** than Key(0).  All of the keys on page Ptr(1) and its subpages have

  62275. ** values greater than Key(0) and less than Key(1).  All of the keys

  62276. ** on Ptr(N) and its subpages have values greater than Key(N-1).  And

  62277. ** so forth.

  62278. **

  62279. ** Finding a particular key requires reading O(log(M)) pages from the 

  62280. ** disk where M is the number of entries in the tree.

  62281. **

  62282. ** In this implementation, a single file can hold one or more separate 

  62283. ** BTrees.  Each BTree is identified by the index of its root page.  The

  62284. ** key and data for any entry are combined to form the "payload".  A

  62285. ** fixed amount of payload can be carried directly on the database

  62286. ** page.  If the payload is larger than the preset amount then surplus

  62287. ** bytes are stored on overflow pages.  The payload for an entry

  62288. ** and the preceding pointer are combined to form a "Cell".  Each 

  62289. ** page has a small header which contains the Ptr(N) pointer and other

  62290. ** information such as the size of key and data.

  62291. **

  62292. ** FORMAT DETAILS

  62293. **

  62294. ** The file is divided into pages.  The first page is called page 1,

  62295. ** the second is page 2, and so forth.  A page number of zero indicates

  62296. ** "no such page".  The page size can be any power of 2 between 512 and 65536.

  62297. ** Each page can be either a btree page, a freelist page, an overflow

  62298. ** page, or a pointer-map page.

  62299. **

  62300. ** The first page is always a btree page.  The first 100 bytes of the first

  62301. ** page contain a special header (the "file header") that describes the file.

  62302. ** The format of the file header is as follows:

  62303. **

  62304. **   OFFSET   SIZE    DESCRIPTION

  62305. **      0      16     Header string: "SQLite format 3\000"

  62306. **     16       2     Page size in bytes.  (1 means 65536)

  62307. **     18       1     File format write version

  62308. **     19       1     File format read version

  62309. **     20       1     Bytes of unused space at the end of each page

  62310. **     21       1     Max embedded payload fraction (must be 64)

  62311. **     22       1     Min embedded payload fraction (must be 32)

  62312. **     23       1     Min leaf payload fraction (must be 32)

  62313. **     24       4     File change counter

  62314. **     28       4     Reserved for future use

  62315. **     32       4     First freelist page

  62316. **     36       4     Number of freelist pages in the file

  62317. **     40      60     15 4-byte meta values passed to higher layers

  62318. **

  62319. **     40       4     Schema cookie

  62320. **     44       4     File format of schema layer

  62321. **     48       4     Size of page cache

  62322. **     52       4     Largest root-page (auto/incr_vacuum)

  62323. **     56       4     1=UTF-8 2=UTF16le 3=UTF16be

  62324. **     60       4     User version

  62325. **     64       4     Incremental vacuum mode

  62326. **     68       4     Application-ID

  62327. **     72      20     unused

  62328. **     92       4     The version-valid-for number

  62329. **     96       4     SQLITE_VERSION_NUMBER

  62330. **

  62331. ** All of the integer values are big-endian (most significant byte first).

  62332. **

  62333. ** The file change counter is incremented when the database is changed

  62334. ** This counter allows other processes to know when the file has changed

  62335. ** and thus when they need to flush their cache.

  62336. **

  62337. ** The max embedded payload fraction is the amount of the total usable

  62338. ** space in a page that can be consumed by a single cell for standard

  62339. ** B-tree (non-LEAFDATA) tables.  A value of 255 means 100%.  The default

  62340. ** is to limit the maximum cell size so that at least 4 cells will fit

  62341. ** on one page.  Thus the default max embedded payload fraction is 64.

  62342. **

  62343. ** If the payload for a cell is larger than the max payload, then extra

  62344. ** payload is spilled to overflow pages.  Once an overflow page is allocated,

  62345. ** as many bytes as possible are moved into the overflow pages without letting

  62346. ** the cell size drop below the min embedded payload fraction.

  62347. **

  62348. ** The min leaf payload fraction is like the min embedded payload fraction

  62349. ** except that it applies to leaf nodes in a LEAFDATA tree.  The maximum

  62350. ** payload fraction for a LEAFDATA tree is always 100% (or 255) and it

  62351. ** not specified in the header.

  62352. **

  62353. ** Each btree pages is divided into three sections:  The header, the

  62354. ** cell pointer array, and the cell content area.  Page 1 also has a 100-byte

  62355. ** file header that occurs before the page header.

  62356. **

  62357. **      |----------------|

  62358. **      | file header    |   100 bytes.  Page 1 only.

  62359. **      |----------------|

  62360. **      | page header    |   8 bytes for leaves.  12 bytes for interior nodes

  62361. **      |----------------|

  62362. **      | cell pointer   |   |  2 bytes per cell.  Sorted order.

  62363. **      | array          |   |  Grows downward

  62364. **      |                |   v

  62365. **      |----------------|

  62366. **      | unallocated    |

  62367. **      | space          |

  62368. **      |----------------|   ^  Grows upwards

  62369. **      | cell content   |   |  Arbitrary order interspersed with freeblocks.

  62370. **      | area           |   |  and free space fragments.

  62371. **      |----------------|

  62372. **

  62373. ** The page headers looks like this:

  62374. **

  62375. **   OFFSET   SIZE     DESCRIPTION

  62376. **      0       1      Flags. 1: intkey, 2: zerodata, 4: leafdata, 8: leaf

  62377. **      1       2      byte offset to the first freeblock

  62378. **      3       2      number of cells on this page

  62379. **      5       2      first byte of the cell content area

  62380. **      7       1      number of fragmented free bytes

  62381. **      8       4      Right child (the Ptr(N) value).  Omitted on leaves.

  62382. **

  62383. ** The flags define the format of this btree page.  The leaf flag means that

  62384. ** this page has no children.  The zerodata flag means that this page carries

  62385. ** only keys and no data.  The intkey flag means that the key is an integer

  62386. ** which is stored in the key size entry of the cell header rather than in

  62387. ** the payload area.

  62388. **

  62389. ** The cell pointer array begins on the first byte after the page header.

  62390. ** The cell pointer array contains zero or more 2-byte numbers which are

  62391. ** offsets from the beginning of the page to the cell content in the cell

  62392. ** content area.  The cell pointers occur in sorted order.  The system strives

  62393. ** to keep free space after the last cell pointer so that new cells can

  62394. ** be easily added without having to defragment the page.

  62395. **

  62396. ** Cell content is stored at the very end of the page and grows toward the

  62397. ** beginning of the page.

  62398. **

  62399. ** Unused space within the cell content area is collected into a linked list of

  62400. ** freeblocks.  Each freeblock is at least 4 bytes in size.  The byte offset

  62401. ** to the first freeblock is given in the header.  Freeblocks occur in

  62402. ** increasing order.  Because a freeblock must be at least 4 bytes in size,

  62403. ** any group of 3 or fewer unused bytes in the cell content area cannot

  62404. ** exist on the freeblock chain.  A group of 3 or fewer free bytes is called

  62405. ** a fragment.  The total number of bytes in all fragments is recorded.

  62406. ** in the page header at offset 7.

  62407. **

  62408. **    SIZE    DESCRIPTION

  62409. **      2     Byte offset of the next freeblock

  62410. **      2     Bytes in this freeblock

  62411. **

  62412. ** Cells are of variable length.  Cells are stored in the cell content area at

  62413. ** the end of the page.  Pointers to the cells are in the cell pointer array

  62414. ** that immediately follows the page header.  Cells is not necessarily

  62415. ** contiguous or in order, but cell pointers are contiguous and in order.

  62416. **

  62417. ** Cell content makes use of variable length integers.  A variable

  62418. ** length integer is 1 to 9 bytes where the lower 7 bits of each 

  62419. ** byte are used.  The integer consists of all bytes that have bit 8 set and

  62420. ** the first byte with bit 8 clear.  The most significant byte of the integer

  62421. ** appears first.  A variable-length integer may not be more than 9 bytes long.

  62422. ** As a special case, all 8 bytes of the 9th byte are used as data.  This

  62423. ** allows a 64-bit integer to be encoded in 9 bytes.

  62424. **

  62425. **    0x00                      becomes  0x00000000

  62426. **    0x7f                      becomes  0x0000007f

  62427. **    0x81 0x00                 becomes  0x00000080

  62428. **    0x82 0x00                 becomes  0x00000100

  62429. **    0x80 0x7f                 becomes  0x0000007f

  62430. **    0x8a 0x91 0xd1 0xac 0x78  becomes  0x12345678

  62431. **    0x81 0x81 0x81 0x81 0x01  becomes  0x10204081

  62432. **

  62433. ** Variable length integers are used for rowids and to hold the number of

  62434. ** bytes of key and data in a btree cell.

  62435. **

  62436. ** The content of a cell looks like this:

  62437. **

  62438. **    SIZE    DESCRIPTION

  62439. **      4     Page number of the left child. Omitted if leaf flag is set.

  62440. **     var    Number of bytes of data. Omitted if the zerodata flag is set.

  62441. **     var    Number of bytes of key. Or the key itself if intkey flag is set.

  62442. **      *     Payload

  62443. **      4     First page of the overflow chain.  Omitted if no overflow

  62444. **

  62445. ** Overflow pages form a linked list.  Each page except the last is completely

  62446. ** filled with data (pagesize - 4 bytes).  The last page can have as little

  62447. ** as 1 byte of data.

  62448. **

  62449. **    SIZE    DESCRIPTION

  62450. **      4     Page number of next overflow page

  62451. **      *     Data

  62452. **

  62453. ** Freelist pages come in two subtypes: trunk pages and leaf pages.  The

  62454. ** file header points to the first in a linked list of trunk page.  Each trunk

  62455. ** page points to multiple leaf pages.  The content of a leaf page is

  62456. ** unspecified.  A trunk page looks like this:

  62457. **

  62458. **    SIZE    DESCRIPTION

  62459. **      4     Page number of next trunk page

  62460. **      4     Number of leaf pointers on this page

  62461. **      *     zero or more pages numbers of leaves

  62462. */

  62463. /* #include "sqliteInt.h" */

  62464. 

  62465. 

  62466. /* The following value is the maximum cell size assuming a maximum page

  62467. ** size give above.

  62468. */

  62469. #define MX_CELL_SIZE(pBt)  ((int)(pBt->pageSize-8))

  62470. 

  62471. /* The maximum number of cells on a single page of the database.  This

  62472. ** assumes a minimum cell size of 6 bytes  (4 bytes for the cell itself

  62473. ** plus 2 bytes for the index to the cell in the page header).  Such

  62474. ** small cells will be rare, but they are possible.

  62475. */

  62476. #define MX_CELL(pBt) ((pBt->pageSize-8)/6)

  62477. 

  62478. /* Forward declarations */

  62479. typedef struct MemPage MemPage;

  62480. typedef struct BtLock BtLock;

  62481. typedef struct CellInfo CellInfo;

  62482. 

  62483. /*

  62484. ** This is a magic string that appears at the beginning of every

  62485. ** SQLite database in order to identify the file as a real database.

  62486. **

  62487. ** You can change this value at compile-time by specifying a

  62488. ** -DSQLITE_FILE_HEADER="..." on the compiler command-line.  The

  62489. ** header must be exactly 16 bytes including the zero-terminator so

  62490. ** the string itself should be 15 characters long.  If you change

  62491. ** the header, then your custom library will not be able to read 

  62492. ** databases generated by the standard tools and the standard tools

  62493. ** will not be able to read databases created by your custom library.

  62494. */

  62495. #ifndef SQLITE_FILE_HEADER /* 123456789 123456 */

  62496. #  define SQLITE_FILE_HEADER "SQLite format 3"

  62497. #endif

  62498. 

  62499. /*

  62500. ** Page type flags.  An ORed combination of these flags appear as the

  62501. ** first byte of on-disk image of every BTree page.

  62502. */

  62503. #define PTF_INTKEY    0x01

  62504. #define PTF_ZERODATA  0x02

  62505. #define PTF_LEAFDATA  0x04

  62506. #define PTF_LEAF      0x08

  62507. 

  62508. /*

  62509. ** An instance of this object stores information about each a single database

  62510. ** page that has been loaded into memory.  The information in this object

  62511. ** is derived from the raw on-disk page content.

  62512. **

  62513. ** As each database page is loaded into memory, the pager allocats an

  62514. ** instance of this object and zeros the first 8 bytes.  (This is the

  62515. ** "extra" information associated with each page of the pager.)

  62516. **

  62517. ** Access to all fields of this structure is controlled by the mutex

  62518. ** stored in MemPage.pBt->mutex.

  62519. */

  62520. struct MemPage {

  62521.   u8 isInit;           /* True if previously initialized. MUST BE FIRST! */

  62522.   u8 bBusy;            /* Prevent endless loops on corrupt database files */

  62523.   u8 intKey;           /* True if table b-trees.  False for index b-trees */

  62524.   u8 intKeyLeaf;       /* True if the leaf of an intKey table */

  62525.   Pgno pgno;           /* Page number for this page */

  62526.   /* Only the first 8 bytes (above) are zeroed by pager.c when a new page

  62527.   ** is allocated. All fields that follow must be initialized before use */

  62528.   u8 leaf;             /* True if a leaf page */

  62529.   u8 hdrOffset;        /* 100 for page 1.  0 otherwise */

  62530.   u8 childPtrSize;     /* 0 if leaf==1.  4 if leaf==0 */

  62531.   u8 max1bytePayload;  /* min(maxLocal,127) */

  62532.   u8 nOverflow;        /* Number of overflow cell bodies in aCell[] */

  62533.   u16 maxLocal;        /* Copy of BtShared.maxLocal or BtShared.maxLeaf */

  62534.   u16 minLocal;        /* Copy of BtShared.minLocal or BtShared.minLeaf */

  62535.   u16 cellOffset;      /* Index in aData of first cell pointer */

  62536.   int nFree;           /* Number of free bytes on the page. -1 for unknown */

  62537.   u16 nCell;           /* Number of cells on this page, local and ovfl */

  62538.   u16 maskPage;        /* Mask for page offset */

  62539.   u16 aiOvfl[4];       /* Insert the i-th overflow cell before the aiOvfl-th

  62540.                        ** non-overflow cell */

  62541.   u8 *apOvfl[4];       /* Pointers to the body of overflow cells */

  62542.   BtShared *pBt;       /* Pointer to BtShared that this page is part of */

  62543.   u8 *aData;           /* Pointer to disk image of the page data */

  62544.   u8 *aDataEnd;        /* One byte past the end of usable data */

  62545.   u8 *aCellIdx;        /* The cell index area */

  62546.   u8 *aDataOfst;       /* Same as aData for leaves.  aData+4 for interior */

  62547.   DbPage *pDbPage;     /* Pager page handle */

  62548.   u16 (*xCellSize)(MemPage*,u8*);             /* cellSizePtr method */

  62549.   void (*xParseCell)(MemPage*,u8*,CellInfo*); /* btreeParseCell method */

  62550. };

  62551. 

  62552. /*

  62553. ** A linked list of the following structures is stored at BtShared.pLock.

  62554. ** Locks are added (or upgraded from READ_LOCK to WRITE_LOCK) when a cursor 

  62555. ** is opened on the table with root page BtShared.iTable. Locks are removed

  62556. ** from this list when a transaction is committed or rolled back, or when

  62557. ** a btree handle is closed.

  62558. */

  62559. struct BtLock {

  62560.   Btree *pBtree;        /* Btree handle holding this lock */

  62561.   Pgno iTable;          /* Root page of table */

  62562.   u8 eLock;             /* READ_LOCK or WRITE_LOCK */

  62563.   BtLock *pNext;        /* Next in BtShared.pLock list */

  62564. };

  62565. 

  62566. /* Candidate values for BtLock.eLock */

  62567. #define READ_LOCK     1

  62568. #define WRITE_LOCK    2

  62569. 

  62570. /* A Btree handle

  62571. **

  62572. ** A database connection contains a pointer to an instance of

  62573. ** this object for every database file that it has open.  This structure

  62574. ** is opaque to the database connection.  The database connection cannot

  62575. ** see the internals of this structure and only deals with pointers to

  62576. ** this structure.

  62577. **

  62578. ** For some database files, the same underlying database cache might be 

  62579. ** shared between multiple connections.  In that case, each connection

  62580. ** has it own instance of this object.  But each instance of this object

  62581. ** points to the same BtShared object.  The database cache and the

  62582. ** schema associated with the database file are all contained within

  62583. ** the BtShared object.

  62584. **

  62585. ** All fields in this structure are accessed under sqlite3.mutex.

  62586. ** The pBt pointer itself may not be changed while there exists cursors 

  62587. ** in the referenced BtShared that point back to this Btree since those

  62588. ** cursors have to go through this Btree to find their BtShared and

  62589. ** they often do so without holding sqlite3.mutex.

  62590. */

  62591. struct Btree {

  62592.   sqlite3 *db;       /* The database connection holding this btree */

  62593.   BtShared *pBt;     /* Sharable content of this btree */

  62594.   u8 inTrans;        /* TRANS_NONE, TRANS_READ or TRANS_WRITE */

  62595.   u8 sharable;       /* True if we can share pBt with another db */

  62596.   u8 locked;         /* True if db currently has pBt locked */

  62597.   u8 hasIncrblobCur; /* True if there are one or more Incrblob cursors */

  62598.   int wantToLock;    /* Number of nested calls to sqlite3BtreeEnter() */

  62599.   int nBackup;       /* Number of backup operations reading this btree */

  62600.   u32 iDataVersion;  /* Combines with pBt->pPager->iDataVersion */

  62601.   Btree *pNext;      /* List of other sharable Btrees from the same db */

  62602.   Btree *pPrev;      /* Back pointer of the same list */

  62603. #ifndef SQLITE_OMIT_SHARED_CACHE

  62604.   BtLock lock;       /* Object used to lock page 1 */

  62605. #endif

  62606. };

  62607. 

  62608. /*

  62609. ** Btree.inTrans may take one of the following values.

  62610. **

  62611. ** If the shared-data extension is enabled, there may be multiple users

  62612. ** of the Btree structure. At most one of these may open a write transaction,

  62613. ** but any number may have active read transactions.

  62614. */

  62615. #define TRANS_NONE  0

  62616. #define TRANS_READ  1

  62617. #define TRANS_WRITE 2

  62618. 

  62619. /*

  62620. ** An instance of this object represents a single database file.

  62621. ** 

  62622. ** A single database file can be in use at the same time by two

  62623. ** or more database connections.  When two or more connections are

  62624. ** sharing the same database file, each connection has it own

  62625. ** private Btree object for the file and each of those Btrees points

  62626. ** to this one BtShared object.  BtShared.nRef is the number of

  62627. ** connections currently sharing this database file.

  62628. **

  62629. ** Fields in this structure are accessed under the BtShared.mutex

  62630. ** mutex, except for nRef and pNext which are accessed under the

  62631. ** global SQLITE_MUTEX_STATIC_MASTER mutex.  The pPager field

  62632. ** may not be modified once it is initially set as long as nRef>0.

  62633. ** The pSchema field may be set once under BtShared.mutex and

  62634. ** thereafter is unchanged as long as nRef>0.

  62635. **

  62636. ** isPending:

  62637. **

  62638. **   If a BtShared client fails to obtain a write-lock on a database

  62639. **   table (because there exists one or more read-locks on the table),

  62640. **   the shared-cache enters 'pending-lock' state and isPending is

  62641. **   set to true.

  62642. **

  62643. **   The shared-cache leaves the 'pending lock' state when either of

  62644. **   the following occur:

  62645. **

  62646. **     1) The current writer (BtShared.pWriter) concludes its transaction, OR

  62647. **     2) The number of locks held by other connections drops to zero.

  62648. **

  62649. **   while in the 'pending-lock' state, no connection may start a new

  62650. **   transaction.

  62651. **

  62652. **   This feature is included to help prevent writer-starvation.

  62653. */

  62654. struct BtShared {

  62655.   Pager *pPager;        /* The page cache */

  62656.   sqlite3 *db;          /* Database connection currently using this Btree */

  62657.   BtCursor *pCursor;    /* A list of all open cursors */

  62658.   MemPage *pPage1;      /* First page of the database */

  62659.   u8 openFlags;         /* Flags to sqlite3BtreeOpen() */

  62660. #ifndef SQLITE_OMIT_AUTOVACUUM

  62661.   u8 autoVacuum;        /* True if auto-vacuum is enabled */

  62662.   u8 incrVacuum;        /* True if incr-vacuum is enabled */

  62663.   u8 bDoTruncate;       /* True to truncate db on commit */

  62664. #endif

  62665.   u8 inTransaction;     /* Transaction state */

  62666.   u8 max1bytePayload;   /* Maximum first byte of cell for a 1-byte payload */

  62667. #ifdef SQLITE_HAS_CODEC

  62668.   u8 optimalReserve;    /* Desired amount of reserved space per page */

  62669. #endif

  62670.   u16 btsFlags;         /* Boolean parameters.  See BTS_* macros below */

  62671.   u16 maxLocal;         /* Maximum local payload in non-LEAFDATA tables */

  62672.   u16 minLocal;         /* Minimum local payload in non-LEAFDATA tables */

  62673.   u16 maxLeaf;          /* Maximum local payload in a LEAFDATA table */

  62674.   u16 minLeaf;          /* Minimum local payload in a LEAFDATA table */

  62675.   u32 pageSize;         /* Total number of bytes on a page */

  62676.   u32 usableSize;       /* Number of usable bytes on each page */

  62677.   int nTransaction;     /* Number of open transactions (read + write) */

  62678.   u32 nPage;            /* Number of pages in the database */

  62679.   void *pSchema;        /* Pointer to space allocated by sqlite3BtreeSchema() */

  62680.   void (*xFreeSchema)(void*);  /* Destructor for BtShared.pSchema */

  62681.   sqlite3_mutex *mutex; /* Non-recursive mutex required to access this object */

  62682.   Bitvec *pHasContent;  /* Set of pages moved to free-list this transaction */

  62683. #ifndef SQLITE_OMIT_SHARED_CACHE

  62684.   int nRef;             /* Number of references to this structure */

  62685.   BtShared *pNext;      /* Next on a list of sharable BtShared structs */

  62686.   BtLock *pLock;        /* List of locks held on this shared-btree struct */

  62687.   Btree *pWriter;       /* Btree with currently open write transaction */

  62688. #endif

  62689.   u8 *pTmpSpace;        /* Temp space sufficient to hold a single cell */

  62690. };

  62691. 

  62692. /*

  62693. ** Allowed values for BtShared.btsFlags

  62694. */

  62695. #define BTS_READ_ONLY        0x0001   /* Underlying file is readonly */

  62696. #define BTS_PAGESIZE_FIXED   0x0002   /* Page size can no longer be changed */

  62697. #define BTS_SECURE_DELETE    0x0004   /* PRAGMA secure_delete is enabled */

  62698. #define BTS_OVERWRITE        0x0008   /* Overwrite deleted content with zeros */

  62699. #define BTS_FAST_SECURE      0x000c   /* Combination of the previous two */

  62700. #define BTS_INITIALLY_EMPTY  0x0010   /* Database was empty at trans start */

  62701. #define BTS_NO_WAL           0x0020   /* Do not open write-ahead-log files */

  62702. #define BTS_EXCLUSIVE        0x0040   /* pWriter has an exclusive lock */

  62703. #define BTS_PENDING          0x0080   /* Waiting for read-locks to clear */

  62704. 

  62705. /*

  62706. ** An instance of the following structure is used to hold information

  62707. ** about a cell.  The parseCellPtr() function fills in this structure

  62708. ** based on information extract from the raw disk page.

  62709. */

  62710. struct CellInfo {

  62711.   i64 nKey;      /* The key for INTKEY tables, or nPayload otherwise */

  62712.   u8 *pPayload;  /* Pointer to the start of payload */

  62713.   u32 nPayload;  /* Bytes of payload */

  62714.   u16 nLocal;    /* Amount of payload held locally, not on overflow */

  62715.   u16 nSize;     /* Size of the cell content on the main b-tree page */

  62716. };

  62717. 

  62718. /*

  62719. ** Maximum depth of an SQLite B-Tree structure. Any B-Tree deeper than

  62720. ** this will be declared corrupt. This value is calculated based on a

  62721. ** maximum database size of 2^31 pages a minimum fanout of 2 for a

  62722. ** root-node and 3 for all other internal nodes.

  62723. **

  62724. ** If a tree that appears to be taller than this is encountered, it is

  62725. ** assumed that the database is corrupt.

  62726. */

  62727. #define BTCURSOR_MAX_DEPTH 20

  62728. 

  62729. /*

  62730. ** A cursor is a pointer to a particular entry within a particular

  62731. ** b-tree within a database file.

  62732. **

  62733. ** The entry is identified by its MemPage and the index in

  62734. ** MemPage.aCell[] of the entry.

  62735. **

  62736. ** A single database file can be shared by two more database connections,

  62737. ** but cursors cannot be shared.  Each cursor is associated with a

  62738. ** particular database connection identified BtCursor.pBtree.db.

  62739. **

  62740. ** Fields in this structure are accessed under the BtShared.mutex

  62741. ** found at self->pBt->mutex. 

  62742. **

  62743. ** skipNext meaning:

  62744. ** The meaning of skipNext depends on the value of eState:

  62745. **

  62746. **   eState            Meaning of skipNext

  62747. **   VALID             skipNext is meaningless and is ignored

  62748. **   INVALID           skipNext is meaningless and is ignored

  62749. **   SKIPNEXT          sqlite3BtreeNext() is a no-op if skipNext>0 and

  62750. **                     sqlite3BtreePrevious() is no-op if skipNext<0.

  62751. **   REQUIRESEEK       restoreCursorPosition() restores the cursor to

  62752. **                     eState=SKIPNEXT if skipNext!=0

  62753. **   FAULT             skipNext holds the cursor fault error code.

  62754. */

  62755. struct BtCursor {

  62756.   u8 eState;                /* One of the CURSOR_XXX constants (see below) */

  62757.   u8 curFlags;              /* zero or more BTCF_* flags defined below */

  62758.   u8 curPagerFlags;         /* Flags to send to sqlite3PagerGet() */

  62759.   u8 hints;                 /* As configured by CursorSetHints() */

  62760.   int skipNext;    /* Prev() is noop if negative. Next() is noop if positive.

  62761.                    ** Error code if eState==CURSOR_FAULT */

  62762.   Btree *pBtree;            /* The Btree to which this cursor belongs */

  62763.   Pgno *aOverflow;          /* Cache of overflow page locations */

  62764.   void *pKey;               /* Saved key that was cursor last known position */

  62765.   /* All fields above are zeroed when the cursor is allocated.  See

  62766.   ** sqlite3BtreeCursorZero().  Fields that follow must be manually

  62767.   ** initialized. */

  62768. #define BTCURSOR_FIRST_UNINIT pBt   /* Name of first uninitialized field */

  62769.   BtShared *pBt;            /* The BtShared this cursor points to */

  62770.   BtCursor *pNext;          /* Forms a linked list of all cursors */

  62771.   CellInfo info;            /* A parse of the cell we are pointing at */

  62772.   i64 nKey;                 /* Size of pKey, or last integer key */

  62773.   Pgno pgnoRoot;            /* The root page of this tree */

  62774.   i8 iPage;                 /* Index of current page in apPage */

  62775.   u8 curIntKey;             /* Value of apPage[0]->intKey */

  62776.   u16 ix;                   /* Current index for apPage[iPage] */

  62777.   u16 aiIdx[BTCURSOR_MAX_DEPTH-1];     /* Current index in apPage[i] */

  62778.   struct KeyInfo *pKeyInfo;            /* Arg passed to comparison function */

  62779.   MemPage *pPage;                        /* Current page */

  62780.   MemPage *apPage[BTCURSOR_MAX_DEPTH-1]; /* Stack of parents of current page */

  62781. };

  62782. 

  62783. /*

  62784. ** Legal values for BtCursor.curFlags

  62785. */

  62786. #define BTCF_WriteFlag    0x01   /* True if a write cursor */

  62787. #define BTCF_ValidNKey    0x02   /* True if info.nKey is valid */

  62788. #define BTCF_ValidOvfl    0x04   /* True if aOverflow is valid */

  62789. #define BTCF_AtLast       0x08   /* Cursor is pointing ot the last entry */

  62790. #define BTCF_Incrblob     0x10   /* True if an incremental I/O handle */

  62791. #define BTCF_Multiple     0x20   /* Maybe another cursor on the same btree */

  62792. 

  62793. /*

  62794. ** Potential values for BtCursor.eState.

  62795. **

  62796. ** CURSOR_INVALID:

  62797. **   Cursor does not point to a valid entry. This can happen (for example) 

  62798. **   because the table is empty or because BtreeCursorFirst() has not been

  62799. **   called.

  62800. **

  62801. ** CURSOR_VALID:

  62802. **   Cursor points to a valid entry. getPayload() etc. may be called.

  62803. **

  62804. ** CURSOR_SKIPNEXT:

  62805. **   Cursor is valid except that the Cursor.skipNext field is non-zero

  62806. **   indicating that the next sqlite3BtreeNext() or sqlite3BtreePrevious()

  62807. **   operation should be a no-op.

  62808. **

  62809. ** CURSOR_REQUIRESEEK:

  62810. **   The table that this cursor was opened on still exists, but has been 

  62811. **   modified since the cursor was last used. The cursor position is saved

  62812. **   in variables BtCursor.pKey and BtCursor.nKey. When a cursor is in 

  62813. **   this state, restoreCursorPosition() can be called to attempt to

  62814. **   seek the cursor to the saved position.

  62815. **

  62816. ** CURSOR_FAULT:

  62817. **   An unrecoverable error (an I/O error or a malloc failure) has occurred

  62818. **   on a different connection that shares the BtShared cache with this

  62819. **   cursor.  The error has left the cache in an inconsistent state.

  62820. **   Do nothing else with this cursor.  Any attempt to use the cursor

  62821. **   should return the error code stored in BtCursor.skipNext

  62822. */

  62823. #define CURSOR_VALID             0

  62824. #define CURSOR_INVALID           1

  62825. #define CURSOR_SKIPNEXT          2

  62826. #define CURSOR_REQUIRESEEK       3

  62827. #define CURSOR_FAULT             4

  62828. 

  62829. /* 

  62830. ** The database page the PENDING_BYTE occupies. This page is never used.

  62831. */

  62832. # define PENDING_BYTE_PAGE(pBt) PAGER_MJ_PGNO(pBt)

  62833. 

  62834. /*

  62835. ** These macros define the location of the pointer-map entry for a 

  62836. ** database page. The first argument to each is the number of usable

  62837. ** bytes on each page of the database (often 1024). The second is the

  62838. ** page number to look up in the pointer map.

  62839. **

  62840. ** PTRMAP_PAGENO returns the database page number of the pointer-map

  62841. ** page that stores the required pointer. PTRMAP_PTROFFSET returns

  62842. ** the offset of the requested map entry.

  62843. **

  62844. ** If the pgno argument passed to PTRMAP_PAGENO is a pointer-map page,

  62845. ** then pgno is returned. So (pgno==PTRMAP_PAGENO(pgsz, pgno)) can be

  62846. ** used to test if pgno is a pointer-map page. PTRMAP_ISPAGE implements

  62847. ** this test.

  62848. */

  62849. #define PTRMAP_PAGENO(pBt, pgno) ptrmapPageno(pBt, pgno)

  62850. #define PTRMAP_PTROFFSET(pgptrmap, pgno) (5*(pgno-pgptrmap-1))

  62851. #define PTRMAP_ISPAGE(pBt, pgno) (PTRMAP_PAGENO((pBt),(pgno))==(pgno))

  62852. 

  62853. /*

  62854. ** The pointer map is a lookup table that identifies the parent page for

  62855. ** each child page in the database file.  The parent page is the page that

  62856. ** contains a pointer to the child.  Every page in the database contains

  62857. ** 0 or 1 parent pages.  (In this context 'database page' refers

  62858. ** to any page that is not part of the pointer map itself.)  Each pointer map

  62859. ** entry consists of a single byte 'type' and a 4 byte parent page number.

  62860. ** The PTRMAP_XXX identifiers below are the valid types.

  62861. **

  62862. ** The purpose of the pointer map is to facility moving pages from one

  62863. ** position in the file to another as part of autovacuum.  When a page

  62864. ** is moved, the pointer in its parent must be updated to point to the

  62865. ** new location.  The pointer map is used to locate the parent page quickly.

  62866. **

  62867. ** PTRMAP_ROOTPAGE: The database page is a root-page. The page-number is not

  62868. **                  used in this case.

  62869. **

  62870. ** PTRMAP_FREEPAGE: The database page is an unused (free) page. The page-number 

  62871. **                  is not used in this case.

  62872. **

  62873. ** PTRMAP_OVERFLOW1: The database page is the first page in a list of 

  62874. **                   overflow pages. The page number identifies the page that

  62875. **                   contains the cell with a pointer to this overflow page.

  62876. **

  62877. ** PTRMAP_OVERFLOW2: The database page is the second or later page in a list of

  62878. **                   overflow pages. The page-number identifies the previous

  62879. **                   page in the overflow page list.

  62880. **

  62881. ** PTRMAP_BTREE: The database page is a non-root btree page. The page number

  62882. **               identifies the parent page in the btree.

  62883. */

  62884. #define PTRMAP_ROOTPAGE 1

  62885. #define PTRMAP_FREEPAGE 2

  62886. #define PTRMAP_OVERFLOW1 3

  62887. #define PTRMAP_OVERFLOW2 4

  62888. #define PTRMAP_BTREE 5

  62889. 

  62890. /* A bunch of assert() statements to check the transaction state variables

  62891. ** of handle p (type Btree*) are internally consistent.

  62892. */

  62893. #define btreeIntegrity(p) \

  62894.   assert( p->pBt->inTransaction!=TRANS_NONE || p->pBt->nTransaction==0 ); \

  62895.   assert( p->pBt->inTransaction>=p->inTrans ); 

  62896. 

  62897. 

  62898. /*

  62899. ** The ISAUTOVACUUM macro is used within balance_nonroot() to determine

  62900. ** if the database supports auto-vacuum or not. Because it is used

  62901. ** within an expression that is an argument to another macro 

  62902. ** (sqliteMallocRaw), it is not possible to use conditional compilation.

  62903. ** So, this macro is defined instead.

  62904. */

  62905. #ifndef SQLITE_OMIT_AUTOVACUUM

  62906. #define ISAUTOVACUUM (pBt->autoVacuum)

  62907. #else

  62908. #define ISAUTOVACUUM 0

  62909. #endif

  62910. 

  62911. 

  62912. /*

  62913. ** This structure is passed around through all the sanity checking routines

  62914. ** in order to keep track of some global state information.

  62915. **

  62916. ** The aRef[] array is allocated so that there is 1 bit for each page in

  62917. ** the database. As the integrity-check proceeds, for each page used in

  62918. ** the database the corresponding bit is set. This allows integrity-check to 

  62919. ** detect pages that are used twice and orphaned pages (both of which 

  62920. ** indicate corruption).

  62921. */

  62922. typedef struct IntegrityCk IntegrityCk;

  62923. struct IntegrityCk {

  62924.   BtShared *pBt;    /* The tree being checked out */

  62925.   Pager *pPager;    /* The associated pager.  Also accessible by pBt->pPager */

  62926.   u8 *aPgRef;       /* 1 bit per page in the db (see above) */

  62927.   Pgno nPage;       /* Number of pages in the database */

  62928.   int mxErr;        /* Stop accumulating errors when this reaches zero */

  62929.   int nErr;         /* Number of messages written to zErrMsg so far */

  62930.   int mallocFailed; /* A memory allocation error has occurred */

  62931.   const char *zPfx; /* Error message prefix */

  62932.   int v1, v2;       /* Values for up to two %d fields in zPfx */

  62933.   StrAccum errMsg;  /* Accumulate the error message text here */

  62934.   u32 *heap;        /* Min-heap used for analyzing cell coverage */

  62935. };

  62936. 

  62937. /*

  62938. ** Routines to read or write a two- and four-byte big-endian integer values.

  62939. */

  62940. #define get2byte(x)   ((x)[0]<<8 | (x)[1])

  62941. #define put2byte(p,v) ((p)[0] = (u8)((v)>>8), (p)[1] = (u8)(v))

  62942. #define get4byte sqlite3Get4byte

  62943. #define put4byte sqlite3Put4byte

  62944. 

  62945. /*

  62946. ** get2byteAligned(), unlike get2byte(), requires that its argument point to a

  62947. ** two-byte aligned address.  get2bytea() is only used for accessing the

  62948. ** cell addresses in a btree header.

  62949. */

  62950. #if SQLITE_BYTEORDER==4321

  62951. # define get2byteAligned(x)  (*(u16*)(x))

  62952. #elif SQLITE_BYTEORDER==1234 && GCC_VERSION>=4008000

  62953. # define get2byteAligned(x)  __builtin_bswap16(*(u16*)(x))

  62954. #elif SQLITE_BYTEORDER==1234 && MSVC_VERSION>=1300

  62955. # define get2byteAligned(x)  _byteswap_ushort(*(u16*)(x))

  62956. #else

  62957. # define get2byteAligned(x)  ((x)[0]<<8 | (x)[1])

  62958. #endif

  62959. 

  62960. /************** End of btreeInt.h ********************************************/

  62961. /************** Continuing where we left off in btmutex.c ********************/

  62962. #ifndef SQLITE_OMIT_SHARED_CACHE

  62963. #if SQLITE_THREADSAFE

  62964. 

  62965. /*

  62966. ** Obtain the BtShared mutex associated with B-Tree handle p. Also,

  62967. ** set BtShared.db to the database handle associated with p and the

  62968. ** p->locked boolean to true.

  62969. */

  62970. static void lockBtreeMutex(Btree *p){

  62971.   assert( p->locked==0 );

  62972.   assert( sqlite3_mutex_notheld(p->pBt->mutex) );

  62973.   assert( sqlite3_mutex_held(p->db->mutex) );

  62974. 

  62975.   sqlite3_mutex_enter(p->pBt->mutex);

  62976.   p->pBt->db = p->db;

  62977.   p->locked = 1;

  62978. }

  62979. 

  62980. /*

  62981. ** Release the BtShared mutex associated with B-Tree handle p and

  62982. ** clear the p->locked boolean.

  62983. */

  62984. static void SQLITE_NOINLINE unlockBtreeMutex(Btree *p){

  62985.   BtShared *pBt = p->pBt;

  62986.   assert( p->locked==1 );

  62987.   assert( sqlite3_mutex_held(pBt->mutex) );

  62988.   assert( sqlite3_mutex_held(p->db->mutex) );

  62989.   assert( p->db==pBt->db );

  62990. 

  62991.   sqlite3_mutex_leave(pBt->mutex);

  62992.   p->locked = 0;

  62993. }

  62994. 

  62995. /* Forward reference */

  62996. static void SQLITE_NOINLINE btreeLockCarefully(Btree *p);

  62997. 

  62998. /*

  62999. ** Enter a mutex on the given BTree object.

  63000. **

  63001. ** If the object is not sharable, then no mutex is ever required

  63002. ** and this routine is a no-op.  The underlying mutex is non-recursive.

  63003. ** But we keep a reference count in Btree.wantToLock so the behavior

  63004. ** of this interface is recursive.

  63005. **

  63006. ** To avoid deadlocks, multiple Btrees are locked in the same order

  63007. ** by all database connections.  The p->pNext is a list of other

  63008. ** Btrees belonging to the same database connection as the p Btree

  63009. ** which need to be locked after p.  If we cannot get a lock on

  63010. ** p, then first unlock all of the others on p->pNext, then wait

  63011. ** for the lock to become available on p, then relock all of the

  63012. ** subsequent Btrees that desire a lock.

  63013. */

  63014. SQLITE_PRIVATE void sqlite3BtreeEnter(Btree *p){

  63015.   /* Some basic sanity checking on the Btree.  The list of Btrees

  63016.   ** connected by pNext and pPrev should be in sorted order by

  63017.   ** Btree.pBt value. All elements of the list should belong to

  63018.   ** the same connection. Only shared Btrees are on the list. */

  63019.   assert( p->pNext==0 || p->pNext->pBt>p->pBt );

  63020.   assert( p->pPrev==0 || p->pPrev->pBt<p->pBt );

  63021.   assert( p->pNext==0 || p->pNext->db==p->db );

  63022.   assert( p->pPrev==0 || p->pPrev->db==p->db );

  63023.   assert( p->sharable || (p->pNext==0 && p->pPrev==0) );

  63024. 

  63025.   /* Check for locking consistency */

  63026.   assert( !p->locked || p->wantToLock>0 );

  63027.   assert( p->sharable || p->wantToLock==0 );

  63028. 

  63029.   /* We should already hold a lock on the database connection */

  63030.   assert( sqlite3_mutex_held(p->db->mutex) );

  63031. 

  63032.   /* Unless the database is sharable and unlocked, then BtShared.db

  63033.   ** should already be set correctly. */

  63034.   assert( (p->locked==0 && p->sharable) || p->pBt->db==p->db );

  63035. 

  63036.   if( !p->sharable ) return;

  63037.   p->wantToLock++;

  63038.   if( p->locked ) return;

  63039.   btreeLockCarefully(p);

  63040. }

  63041. 

  63042. /* This is a helper function for sqlite3BtreeLock(). By moving

  63043. ** complex, but seldom used logic, out of sqlite3BtreeLock() and

  63044. ** into this routine, we avoid unnecessary stack pointer changes

  63045. ** and thus help the sqlite3BtreeLock() routine to run much faster

  63046. ** in the common case.

  63047. */

  63048. static void SQLITE_NOINLINE btreeLockCarefully(Btree *p){

  63049.   Btree *pLater;

  63050. 

  63051.   /* In most cases, we should be able to acquire the lock we

  63052.   ** want without having to go through the ascending lock

  63053.   ** procedure that follows.  Just be sure not to block.

  63054.   */

  63055.   if( sqlite3_mutex_try(p->pBt->mutex)==SQLITE_OK ){

  63056.     p->pBt->db = p->db;

  63057.     p->locked = 1;

  63058.     return;

  63059.   }

  63060. 

  63061.   /* To avoid deadlock, first release all locks with a larger

  63062.   ** BtShared address.  Then acquire our lock.  Then reacquire

  63063.   ** the other BtShared locks that we used to hold in ascending

  63064.   ** order.

  63065.   */

  63066.   for(pLater=p->pNext; pLater; pLater=pLater->pNext){

  63067.     assert( pLater->sharable );

  63068.     assert( pLater->pNext==0 || pLater->pNext->pBt>pLater->pBt );

  63069.     assert( !pLater->locked || pLater->wantToLock>0 );

  63070.     if( pLater->locked ){

  63071.       unlockBtreeMutex(pLater);

  63072.     }

  63073.   }

  63074.   lockBtreeMutex(p);

  63075.   for(pLater=p->pNext; pLater; pLater=pLater->pNext){

  63076.     if( pLater->wantToLock ){

  63077.       lockBtreeMutex(pLater);

  63078.     }

  63079.   }

  63080. }

  63081. 

  63082. 

  63083. /*

  63084. ** Exit the recursive mutex on a Btree.

  63085. */

  63086. SQLITE_PRIVATE void sqlite3BtreeLeave(Btree *p){

  63087.   assert( sqlite3_mutex_held(p->db->mutex) );

  63088.   if( p->sharable ){

  63089.     assert( p->wantToLock>0 );

  63090.     p->wantToLock--;

  63091.     if( p->wantToLock==0 ){

  63092.       unlockBtreeMutex(p);

  63093.     }

  63094.   }

  63095. }

  63096. 

  63097. #ifndef NDEBUG

  63098. /*

  63099. ** Return true if the BtShared mutex is held on the btree, or if the

  63100. ** B-Tree is not marked as sharable.

  63101. **

  63102. ** This routine is used only from within assert() statements.

  63103. */

  63104. SQLITE_PRIVATE int sqlite3BtreeHoldsMutex(Btree *p){

  63105.   assert( p->sharable==0 || p->locked==0 || p->wantToLock>0 );

  63106.   assert( p->sharable==0 || p->locked==0 || p->db==p->pBt->db );

  63107.   assert( p->sharable==0 || p->locked==0 || sqlite3_mutex_held(p->pBt->mutex) );

  63108.   assert( p->sharable==0 || p->locked==0 || sqlite3_mutex_held(p->db->mutex) );

  63109. 

  63110.   return (p->sharable==0 || p->locked);

  63111. }

  63112. #endif

  63113. 

  63114. 

  63115. /*

  63116. ** Enter the mutex on every Btree associated with a database

  63117. ** connection.  This is needed (for example) prior to parsing

  63118. ** a statement since we will be comparing table and column names

  63119. ** against all schemas and we do not want those schemas being

  63120. ** reset out from under us.

  63121. **

  63122. ** There is a corresponding leave-all procedures.

  63123. **

  63124. ** Enter the mutexes in accending order by BtShared pointer address

  63125. ** to avoid the possibility of deadlock when two threads with

  63126. ** two or more btrees in common both try to lock all their btrees

  63127. ** at the same instant.

  63128. */

  63129. static void SQLITE_NOINLINE btreeEnterAll(sqlite3 *db){

  63130.   int i;

  63131.   int skipOk = 1;

  63132.   Btree *p;

  63133.   assert( sqlite3_mutex_held(db->mutex) );

  63134.   for(i=0; i<db->nDb; i++){

  63135.     p = db->aDb[i].pBt;

  63136.     if( p && p->sharable ){

  63137.       sqlite3BtreeEnter(p);

  63138.       skipOk = 0;

  63139.     }

  63140.   }

  63141.   db->noSharedCache = skipOk;

  63142. }

  63143. SQLITE_PRIVATE void sqlite3BtreeEnterAll(sqlite3 *db){

  63144.   if( db->noSharedCache==0 ) btreeEnterAll(db);

  63145. }

  63146. static void SQLITE_NOINLINE btreeLeaveAll(sqlite3 *db){

  63147.   int i;

  63148.   Btree *p;

  63149.   assert( sqlite3_mutex_held(db->mutex) );

  63150.   for(i=0; i<db->nDb; i++){

  63151.     p = db->aDb[i].pBt;

  63152.     if( p ) sqlite3BtreeLeave(p);

  63153.   }

  63154. }

  63155. SQLITE_PRIVATE void sqlite3BtreeLeaveAll(sqlite3 *db){

  63156.   if( db->noSharedCache==0 ) btreeLeaveAll(db);

  63157. }

  63158. 

  63159. #ifndef NDEBUG

  63160. /*

  63161. ** Return true if the current thread holds the database connection

  63162. ** mutex and all required BtShared mutexes.

  63163. **

  63164. ** This routine is used inside assert() statements only.

  63165. */

  63166. SQLITE_PRIVATE int sqlite3BtreeHoldsAllMutexes(sqlite3 *db){

  63167.   int i;

  63168.   if( !sqlite3_mutex_held(db->mutex) ){

  63169.     return 0;

  63170.   }

  63171.   for(i=0; i<db->nDb; i++){

  63172.     Btree *p;

  63173.     p = db->aDb[i].pBt;

  63174.     if( p && p->sharable &&

  63175.          (p->wantToLock==0 || !sqlite3_mutex_held(p->pBt->mutex)) ){

  63176.       return 0;

  63177.     }

  63178.   }

  63179.   return 1;

  63180. }

  63181. #endif /* NDEBUG */

  63182. 

  63183. #ifndef NDEBUG

  63184. /*

  63185. ** Return true if the correct mutexes are held for accessing the

  63186. ** db->aDb[iDb].pSchema structure.  The mutexes required for schema

  63187. ** access are:

  63188. **

  63189. **   (1) The mutex on db

  63190. **   (2) if iDb!=1, then the mutex on db->aDb[iDb].pBt.

  63191. **

  63192. ** If pSchema is not NULL, then iDb is computed from pSchema and

  63193. ** db using sqlite3SchemaToIndex().

  63194. */

  63195. SQLITE_PRIVATE int sqlite3SchemaMutexHeld(sqlite3 *db, int iDb, Schema *pSchema){

  63196.   Btree *p;

  63197.   assert( db!=0 );

  63198.   if( pSchema ) iDb = sqlite3SchemaToIndex(db, pSchema);

  63199.   assert( iDb>=0 && iDb<db->nDb );

  63200.   if( !sqlite3_mutex_held(db->mutex) ) return 0;

  63201.   if( iDb==1 ) return 1;

  63202.   p = db->aDb[iDb].pBt;

  63203.   assert( p!=0 );

  63204.   return p->sharable==0 || p->locked==1;

  63205. }

  63206. #endif /* NDEBUG */

  63207. 

  63208. #else /* SQLITE_THREADSAFE>0 above.  SQLITE_THREADSAFE==0 below */

  63209. /*

  63210. ** The following are special cases for mutex enter routines for use

  63211. ** in single threaded applications that use shared cache.  Except for

  63212. ** these two routines, all mutex operations are no-ops in that case and

  63213. ** are null #defines in btree.h.

  63214. **

  63215. ** If shared cache is disabled, then all btree mutex routines, including

  63216. ** the ones below, are no-ops and are null #defines in btree.h.

  63217. */

  63218. 

  63219. SQLITE_PRIVATE void sqlite3BtreeEnter(Btree *p){

  63220.   p->pBt->db = p->db;

  63221. }

  63222. SQLITE_PRIVATE void sqlite3BtreeEnterAll(sqlite3 *db){

  63223.   int i;

  63224.   for(i=0; i<db->nDb; i++){

  63225.     Btree *p = db->aDb[i].pBt;

  63226.     if( p ){

  63227.       p->pBt->db = p->db;

  63228.     }

  63229.   }

  63230. }

  63231. #endif /* if SQLITE_THREADSAFE */

  63232. 

  63233. #ifndef SQLITE_OMIT_INCRBLOB

  63234. /*

  63235. ** Enter a mutex on a Btree given a cursor owned by that Btree. 

  63236. **

  63237. ** These entry points are used by incremental I/O only. Enter() is required 

  63238. ** any time OMIT_SHARED_CACHE is not defined, regardless of whether or not 

  63239. ** the build is threadsafe. Leave() is only required by threadsafe builds.

  63240. */

  63241. SQLITE_PRIVATE void sqlite3BtreeEnterCursor(BtCursor *pCur){

  63242.   sqlite3BtreeEnter(pCur->pBtree);

  63243. }

  63244. # if SQLITE_THREADSAFE

  63245. SQLITE_PRIVATE void sqlite3BtreeLeaveCursor(BtCursor *pCur){

  63246.   sqlite3BtreeLeave(pCur->pBtree);

  63247. }

  63248. # endif

  63249. #endif /* ifndef SQLITE_OMIT_INCRBLOB */

  63250. 

  63251. #endif /* ifndef SQLITE_OMIT_SHARED_CACHE */

  63252. 

  63253. /************** End of btmutex.c *********************************************/

  63254. /************** Begin file btree.c *******************************************/

  63255. /*

  63256. ** 2004 April 6

  63257. **

  63258. ** The author disclaims copyright to this source code.  In place of

  63259. ** a legal notice, here is a blessing:

  63260. **

  63261. **    May you do good and not evil.

  63262. **    May you find forgiveness for yourself and forgive others.

  63263. **    May you share freely, never taking more than you give.

  63264. **

  63265. *************************************************************************

  63266. ** This file implements an external (disk-based) database using BTrees.

  63267. ** See the header comment on "btreeInt.h" for additional information.

  63268. ** Including a description of file format and an overview of operation.

  63269. */

  63270. /* #include "btreeInt.h" */

  63271. 

  63272. /*

  63273. ** The header string that appears at the beginning of every

  63274. ** SQLite database.

  63275. */

  63276. static const char zMagicHeader[] = SQLITE_FILE_HEADER;

  63277. 

  63278. /*

  63279. ** Set this global variable to 1 to enable tracing using the TRACE

  63280. ** macro.

  63281. */

  63282. #if 0

  63283. int sqlite3BtreeTrace=1;  /* True to enable tracing */

  63284. # define TRACE(X)  if(sqlite3BtreeTrace){printf X;fflush(stdout);}

  63285. #else

  63286. # define TRACE(X)

  63287. #endif

  63288. 

  63289. /*

  63290. ** Extract a 2-byte big-endian integer from an array of unsigned bytes.

  63291. ** But if the value is zero, make it 65536.

  63292. **

  63293. ** This routine is used to extract the "offset to cell content area" value

  63294. ** from the header of a btree page.  If the page size is 65536 and the page

  63295. ** is empty, the offset should be 65536, but the 2-byte value stores zero.

  63296. ** This routine makes the necessary adjustment to 65536.

  63297. */

  63298. #define get2byteNotZero(X)  (((((int)get2byte(X))-1)&0xffff)+1)

  63299. 

  63300. /*

  63301. ** Values passed as the 5th argument to allocateBtreePage()

  63302. */

  63303. #define BTALLOC_ANY   0           /* Allocate any page */

  63304. #define BTALLOC_EXACT 1           /* Allocate exact page if possible */

  63305. #define BTALLOC_LE    2           /* Allocate any page <= the parameter */

  63306. 

  63307. /*

  63308. ** Macro IfNotOmitAV(x) returns (x) if SQLITE_OMIT_AUTOVACUUM is not 

  63309. ** defined, or 0 if it is. For example:

  63310. **

  63311. **   bIncrVacuum = IfNotOmitAV(pBtShared->incrVacuum);

  63312. */

  63313. #ifndef SQLITE_OMIT_AUTOVACUUM

  63314. #define IfNotOmitAV(expr) (expr)

  63315. #else

  63316. #define IfNotOmitAV(expr) 0

  63317. #endif

  63318. 

  63319. #ifndef SQLITE_OMIT_SHARED_CACHE

  63320. /*

  63321. ** A list of BtShared objects that are eligible for participation

  63322. ** in shared cache.  This variable has file scope during normal builds,

  63323. ** but the test harness needs to access it so we make it global for 

  63324. ** test builds.

  63325. **

  63326. ** Access to this variable is protected by SQLITE_MUTEX_STATIC_MASTER.

  63327. */

  63328. #ifdef SQLITE_TEST

  63329. SQLITE_PRIVATE BtShared *SQLITE_WSD sqlite3SharedCacheList = 0;

  63330. #else

  63331. static BtShared *SQLITE_WSD sqlite3SharedCacheList = 0;

  63332. #endif

  63333. #endif /* SQLITE_OMIT_SHARED_CACHE */

  63334. 

  63335. #ifndef SQLITE_OMIT_SHARED_CACHE

  63336. /*

  63337. ** Enable or disable the shared pager and schema features.

  63338. **

  63339. ** This routine has no effect on existing database connections.

  63340. ** The shared cache setting effects only future calls to

  63341. ** sqlite3_open(), sqlite3_open16(), or sqlite3_open_v2().

  63342. */

  63343. SQLITE_API int sqlite3_enable_shared_cache(int enable){

  63344.   sqlite3GlobalConfig.sharedCacheEnabled = enable;

  63345.   return SQLITE_OK;

  63346. }

  63347. #endif

  63348. 

  63349. 

  63350. 

  63351. #ifdef SQLITE_OMIT_SHARED_CACHE

  63352.   /*

  63353.   ** The functions querySharedCacheTableLock(), setSharedCacheTableLock(),

  63354.   ** and clearAllSharedCacheTableLocks()

  63355.   ** manipulate entries in the BtShared.pLock linked list used to store

  63356.   ** shared-cache table level locks. If the library is compiled with the

  63357.   ** shared-cache feature disabled, then there is only ever one user

  63358.   ** of each BtShared structure and so this locking is not necessary. 

  63359.   ** So define the lock related functions as no-ops.

  63360.   */

  63361.   #define querySharedCacheTableLock(a,b,c) SQLITE_OK

  63362.   #define setSharedCacheTableLock(a,b,c) SQLITE_OK

  63363.   #define clearAllSharedCacheTableLocks(a)

  63364.   #define downgradeAllSharedCacheTableLocks(a)

  63365.   #define hasSharedCacheTableLock(a,b,c,d) 1

  63366.   #define hasReadConflicts(a, b) 0

  63367. #endif

  63368. 

  63369. /*

  63370. ** Implementation of the SQLITE_CORRUPT_PAGE() macro. Takes a single

  63371. ** (MemPage*) as an argument. The (MemPage*) must not be NULL.

  63372. **

  63373. ** If SQLITE_DEBUG is not defined, then this macro is equivalent to

  63374. ** SQLITE_CORRUPT_BKPT. Or, if SQLITE_DEBUG is set, then the log message

  63375. ** normally produced as a side-effect of SQLITE_CORRUPT_BKPT is augmented

  63376. ** with the page number and filename associated with the (MemPage*).

  63377. */

  63378. #ifdef SQLITE_DEBUG

  63379. int corruptPageError(int lineno, MemPage *p){

  63380.   char *zMsg;

  63381.   sqlite3BeginBenignMalloc();

  63382.   zMsg = sqlite3_mprintf("database corruption page %d of %s",

  63383.       (int)p->pgno, sqlite3PagerFilename(p->pBt->pPager, 0)

  63384.   );

  63385.   sqlite3EndBenignMalloc();

  63386.   if( zMsg ){

  63387.     sqlite3ReportError(SQLITE_CORRUPT, lineno, zMsg);

  63388.   }

  63389.   sqlite3_free(zMsg);

  63390.   return SQLITE_CORRUPT_BKPT;

  63391. }

  63392. # define SQLITE_CORRUPT_PAGE(pMemPage) corruptPageError(__LINE__, pMemPage)

  63393. #else

  63394. # define SQLITE_CORRUPT_PAGE(pMemPage) SQLITE_CORRUPT_PGNO(pMemPage->pgno)

  63395. #endif

  63396. 

  63397. #ifndef SQLITE_OMIT_SHARED_CACHE

  63398. 

  63399. #ifdef SQLITE_DEBUG

  63400. /*

  63401. **** This function is only used as part of an assert() statement. ***

  63402. **

  63403. ** Check to see if pBtree holds the required locks to read or write to the 

  63404. ** table with root page iRoot.   Return 1 if it does and 0 if not.

  63405. **

  63406. ** For example, when writing to a table with root-page iRoot via 

  63407. ** Btree connection pBtree:

  63408. **

  63409. **    assert( hasSharedCacheTableLock(pBtree, iRoot, 0, WRITE_LOCK) );

  63410. **

  63411. ** When writing to an index that resides in a sharable database, the 

  63412. ** caller should have first obtained a lock specifying the root page of

  63413. ** the corresponding table. This makes things a bit more complicated,

  63414. ** as this module treats each table as a separate structure. To determine

  63415. ** the table corresponding to the index being written, this

  63416. ** function has to search through the database schema.

  63417. **

  63418. ** Instead of a lock on the table/index rooted at page iRoot, the caller may

  63419. ** hold a write-lock on the schema table (root page 1). This is also

  63420. ** acceptable.

  63421. */

  63422. static int hasSharedCacheTableLock(

  63423.   Btree *pBtree,         /* Handle that must hold lock */

  63424.   Pgno iRoot,            /* Root page of b-tree */

  63425.   int isIndex,           /* True if iRoot is the root of an index b-tree */

  63426.   int eLockType          /* Required lock type (READ_LOCK or WRITE_LOCK) */

  63427. ){

  63428.   Schema *pSchema = (Schema *)pBtree->pBt->pSchema;

  63429.   Pgno iTab = 0;

  63430.   BtLock *pLock;

  63431. 

  63432.   /* If this database is not shareable, or if the client is reading

  63433.   ** and has the read-uncommitted flag set, then no lock is required. 

  63434.   ** Return true immediately.

  63435.   */

  63436.   if( (pBtree->sharable==0)

  63437.    || (eLockType==READ_LOCK && (pBtree->db->flags & SQLITE_ReadUncommit))

  63438.   ){

  63439.     return 1;

  63440.   }

  63441. 

  63442.   /* If the client is reading  or writing an index and the schema is

  63443.   ** not loaded, then it is too difficult to actually check to see if

  63444.   ** the correct locks are held.  So do not bother - just return true.

  63445.   ** This case does not come up very often anyhow.

  63446.   */

  63447.   if( isIndex && (!pSchema || (pSchema->schemaFlags&DB_SchemaLoaded)==0) ){

  63448.     return 1;

  63449.   }

  63450. 

  63451.   /* Figure out the root-page that the lock should be held on. For table

  63452.   ** b-trees, this is just the root page of the b-tree being read or

  63453.   ** written. For index b-trees, it is the root page of the associated

  63454.   ** table.  */

  63455.   if( isIndex ){

  63456.     HashElem *p;

  63457.     for(p=sqliteHashFirst(&pSchema->idxHash); p; p=sqliteHashNext(p)){

  63458.       Index *pIdx = (Index *)sqliteHashData(p);

  63459.       if( pIdx->tnum==(int)iRoot ){

  63460.         if( iTab ){

  63461.           /* Two or more indexes share the same root page.  There must

  63462.           ** be imposter tables.  So just return true.  The assert is not

  63463.           ** useful in that case. */

  63464.           return 1;

  63465.         }

  63466.         iTab = pIdx->pTable->tnum;

  63467.       }

  63468.     }

  63469.   }else{

  63470.     iTab = iRoot;

  63471.   }

  63472. 

  63473.   /* Search for the required lock. Either a write-lock on root-page iTab, a 

  63474.   ** write-lock on the schema table, or (if the client is reading) a

  63475.   ** read-lock on iTab will suffice. Return 1 if any of these are found.  */

  63476.   for(pLock=pBtree->pBt->pLock; pLock; pLock=pLock->pNext){

  63477.     if( pLock->pBtree==pBtree 

  63478.      && (pLock->iTable==iTab || (pLock->eLock==WRITE_LOCK && pLock->iTable==1))

  63479.      && pLock->eLock>=eLockType 

  63480.     ){

  63481.       return 1;

  63482.     }

  63483.   }

  63484. 

  63485.   /* Failed to find the required lock. */

  63486.   return 0;

  63487. }

  63488. #endif /* SQLITE_DEBUG */

  63489. 

  63490. #ifdef SQLITE_DEBUG

  63491. /*

  63492. **** This function may be used as part of assert() statements only. ****

  63493. **

  63494. ** Return true if it would be illegal for pBtree to write into the

  63495. ** table or index rooted at iRoot because other shared connections are

  63496. ** simultaneously reading that same table or index.

  63497. **

  63498. ** It is illegal for pBtree to write if some other Btree object that

  63499. ** shares the same BtShared object is currently reading or writing

  63500. ** the iRoot table.  Except, if the other Btree object has the

  63501. ** read-uncommitted flag set, then it is OK for the other object to

  63502. ** have a read cursor.

  63503. **

  63504. ** For example, before writing to any part of the table or index

  63505. ** rooted at page iRoot, one should call:

  63506. **

  63507. **    assert( !hasReadConflicts(pBtree, iRoot) );

  63508. */

  63509. static int hasReadConflicts(Btree *pBtree, Pgno iRoot){

  63510.   BtCursor *p;

  63511.   for(p=pBtree->pBt->pCursor; p; p=p->pNext){

  63512.     if( p->pgnoRoot==iRoot 

  63513.      && p->pBtree!=pBtree

  63514.      && 0==(p->pBtree->db->flags & SQLITE_ReadUncommit)

  63515.     ){

  63516.       return 1;

  63517.     }

  63518.   }

  63519.   return 0;

  63520. }

  63521. #endif    /* #ifdef SQLITE_DEBUG */

  63522. 

  63523. /*

  63524. ** Query to see if Btree handle p may obtain a lock of type eLock 

  63525. ** (READ_LOCK or WRITE_LOCK) on the table with root-page iTab. Return

  63526. ** SQLITE_OK if the lock may be obtained (by calling

  63527. ** setSharedCacheTableLock()), or SQLITE_LOCKED if not.

  63528. */

  63529. static int querySharedCacheTableLock(Btree *p, Pgno iTab, u8 eLock){

  63530.   BtShared *pBt = p->pBt;

  63531.   BtLock *pIter;

  63532. 

  63533.   assert( sqlite3BtreeHoldsMutex(p) );

  63534.   assert( eLock==READ_LOCK || eLock==WRITE_LOCK );

  63535.   assert( p->db!=0 );

  63536.   assert( !(p->db->flags&SQLITE_ReadUncommit)||eLock==WRITE_LOCK||iTab==1 );

  63537.   

  63538.   /* If requesting a write-lock, then the Btree must have an open write

  63539.   ** transaction on this file. And, obviously, for this to be so there 

  63540.   ** must be an open write transaction on the file itself.

  63541.   */

  63542.   assert( eLock==READ_LOCK || (p==pBt->pWriter && p->inTrans==TRANS_WRITE) );

  63543.   assert( eLock==READ_LOCK || pBt->inTransaction==TRANS_WRITE );

  63544.   

  63545.   /* This routine is a no-op if the shared-cache is not enabled */

  63546.   if( !p->sharable ){

  63547.     return SQLITE_OK;

  63548.   }

  63549. 

  63550.   /* If some other connection is holding an exclusive lock, the

  63551.   ** requested lock may not be obtained.

  63552.   */

  63553.   if( pBt->pWriter!=p && (pBt->btsFlags & BTS_EXCLUSIVE)!=0 ){

  63554.     sqlite3ConnectionBlocked(p->db, pBt->pWriter->db);

  63555.     return SQLITE_LOCKED_SHAREDCACHE;

  63556.   }

  63557. 

  63558.   for(pIter=pBt->pLock; pIter; pIter=pIter->pNext){

  63559.     /* The condition (pIter->eLock!=eLock) in the following if(...) 

  63560.     ** statement is a simplification of:

  63561.     **

  63562.     **   (eLock==WRITE_LOCK || pIter->eLock==WRITE_LOCK)

  63563.     **

  63564.     ** since we know that if eLock==WRITE_LOCK, then no other connection

  63565.     ** may hold a WRITE_LOCK on any table in this file (since there can

  63566.     ** only be a single writer).

  63567.     */

  63568.     assert( pIter->eLock==READ_LOCK || pIter->eLock==WRITE_LOCK );

  63569.     assert( eLock==READ_LOCK || pIter->pBtree==p || pIter->eLock==READ_LOCK);

  63570.     if( pIter->pBtree!=p && pIter->iTable==iTab && pIter->eLock!=eLock ){

  63571.       sqlite3ConnectionBlocked(p->db, pIter->pBtree->db);

  63572.       if( eLock==WRITE_LOCK ){

  63573.         assert( p==pBt->pWriter );

  63574.         pBt->btsFlags |= BTS_PENDING;

  63575.       }

  63576.       return SQLITE_LOCKED_SHAREDCACHE;

  63577.     }

  63578.   }

  63579.   return SQLITE_OK;

  63580. }

  63581. #endif /* !SQLITE_OMIT_SHARED_CACHE */

  63582. 

  63583. #ifndef SQLITE_OMIT_SHARED_CACHE

  63584. /*

  63585. ** Add a lock on the table with root-page iTable to the shared-btree used

  63586. ** by Btree handle p. Parameter eLock must be either READ_LOCK or 

  63587. ** WRITE_LOCK.

  63588. **

  63589. ** This function assumes the following:

  63590. **

  63591. **   (a) The specified Btree object p is connected to a sharable

  63592. **       database (one with the BtShared.sharable flag set), and

  63593. **

  63594. **   (b) No other Btree objects hold a lock that conflicts

  63595. **       with the requested lock (i.e. querySharedCacheTableLock() has

  63596. **       already been called and returned SQLITE_OK).

  63597. **

  63598. ** SQLITE_OK is returned if the lock is added successfully. SQLITE_NOMEM 

  63599. ** is returned if a malloc attempt fails.

  63600. */

  63601. static int setSharedCacheTableLock(Btree *p, Pgno iTable, u8 eLock){

  63602.   BtShared *pBt = p->pBt;

  63603.   BtLock *pLock = 0;

  63604.   BtLock *pIter;

  63605. 

  63606.   assert( sqlite3BtreeHoldsMutex(p) );

  63607.   assert( eLock==READ_LOCK || eLock==WRITE_LOCK );

  63608.   assert( p->db!=0 );

  63609. 

  63610.   /* A connection with the read-uncommitted flag set will never try to

  63611.   ** obtain a read-lock using this function. The only read-lock obtained

  63612.   ** by a connection in read-uncommitted mode is on the sqlite_master 

  63613.   ** table, and that lock is obtained in BtreeBeginTrans().  */

  63614.   assert( 0==(p->db->flags&SQLITE_ReadUncommit) || eLock==WRITE_LOCK );

  63615. 

  63616.   /* This function should only be called on a sharable b-tree after it 

  63617.   ** has been determined that no other b-tree holds a conflicting lock.  */

  63618.   assert( p->sharable );

  63619.   assert( SQLITE_OK==querySharedCacheTableLock(p, iTable, eLock) );

  63620. 

  63621.   /* First search the list for an existing lock on this table. */

  63622.   for(pIter=pBt->pLock; pIter; pIter=pIter->pNext){

  63623.     if( pIter->iTable==iTable && pIter->pBtree==p ){

  63624.       pLock = pIter;

  63625.       break;

  63626.     }

  63627.   }

  63628. 

  63629.   /* If the above search did not find a BtLock struct associating Btree p

  63630.   ** with table iTable, allocate one and link it into the list.

  63631.   */

  63632.   if( !pLock ){

  63633.     pLock = (BtLock *)sqlite3MallocZero(sizeof(BtLock));

  63634.     if( !pLock ){

  63635.       return SQLITE_NOMEM_BKPT;

  63636.     }

  63637.     pLock->iTable = iTable;

  63638.     pLock->pBtree = p;

  63639.     pLock->pNext = pBt->pLock;

  63640.     pBt->pLock = pLock;

  63641.   }

  63642. 

  63643.   /* Set the BtLock.eLock variable to the maximum of the current lock

  63644.   ** and the requested lock. This means if a write-lock was already held

  63645.   ** and a read-lock requested, we don't incorrectly downgrade the lock.

  63646.   */

  63647.   assert( WRITE_LOCK>READ_LOCK );

  63648.   if( eLock>pLock->eLock ){

  63649.     pLock->eLock = eLock;

  63650.   }

  63651. 

  63652.   return SQLITE_OK;

  63653. }

  63654. #endif /* !SQLITE_OMIT_SHARED_CACHE */

  63655. 

  63656. #ifndef SQLITE_OMIT_SHARED_CACHE

  63657. /*

  63658. ** Release all the table locks (locks obtained via calls to

  63659. ** the setSharedCacheTableLock() procedure) held by Btree object p.

  63660. **

  63661. ** This function assumes that Btree p has an open read or write 

  63662. ** transaction. If it does not, then the BTS_PENDING flag

  63663. ** may be incorrectly cleared.

  63664. */

  63665. static void clearAllSharedCacheTableLocks(Btree *p){

  63666.   BtShared *pBt = p->pBt;

  63667.   BtLock **ppIter = &pBt->pLock;

  63668. 

  63669.   assert( sqlite3BtreeHoldsMutex(p) );

  63670.   assert( p->sharable || 0==*ppIter );

  63671.   assert( p->inTrans>0 );

  63672. 

  63673.   while( *ppIter ){

  63674.     BtLock *pLock = *ppIter;

  63675.     assert( (pBt->btsFlags & BTS_EXCLUSIVE)==0 || pBt->pWriter==pLock->pBtree );

  63676.     assert( pLock->pBtree->inTrans>=pLock->eLock );

  63677.     if( pLock->pBtree==p ){

  63678.       *ppIter = pLock->pNext;

  63679.       assert( pLock->iTable!=1 || pLock==&p->lock );

  63680.       if( pLock->iTable!=1 ){

  63681.         sqlite3_free(pLock);

  63682.       }

  63683.     }else{

  63684.       ppIter = &pLock->pNext;

  63685.     }

  63686.   }

  63687. 

  63688.   assert( (pBt->btsFlags & BTS_PENDING)==0 || pBt->pWriter );

  63689.   if( pBt->pWriter==p ){

  63690.     pBt->pWriter = 0;

  63691.     pBt->btsFlags &= ~(BTS_EXCLUSIVE|BTS_PENDING);

  63692.   }else if( pBt->nTransaction==2 ){

  63693.     /* This function is called when Btree p is concluding its 

  63694.     ** transaction. If there currently exists a writer, and p is not

  63695.     ** that writer, then the number of locks held by connections other

  63696.     ** than the writer must be about to drop to zero. In this case

  63697.     ** set the BTS_PENDING flag to 0.

  63698.     **

  63699.     ** If there is not currently a writer, then BTS_PENDING must

  63700.     ** be zero already. So this next line is harmless in that case.

  63701.     */

  63702.     pBt->btsFlags &= ~BTS_PENDING;

  63703.   }

  63704. }

  63705. 

  63706. /*

  63707. ** This function changes all write-locks held by Btree p into read-locks.

  63708. */

  63709. static void downgradeAllSharedCacheTableLocks(Btree *p){

  63710.   BtShared *pBt = p->pBt;

  63711.   if( pBt->pWriter==p ){

  63712.     BtLock *pLock;

  63713.     pBt->pWriter = 0;

  63714.     pBt->btsFlags &= ~(BTS_EXCLUSIVE|BTS_PENDING);

  63715.     for(pLock=pBt->pLock; pLock; pLock=pLock->pNext){

  63716.       assert( pLock->eLock==READ_LOCK || pLock->pBtree==p );

  63717.       pLock->eLock = READ_LOCK;

  63718.     }

  63719.   }

  63720. }

  63721. 

  63722. #endif /* SQLITE_OMIT_SHARED_CACHE */

  63723. 

  63724. static void releasePage(MemPage *pPage);         /* Forward reference */

  63725. static void releasePageOne(MemPage *pPage);      /* Forward reference */

  63726. static void releasePageNotNull(MemPage *pPage);  /* Forward reference */

  63727. 

  63728. /*

  63729. ***** This routine is used inside of assert() only ****

  63730. **

  63731. ** Verify that the cursor holds the mutex on its BtShared

  63732. */

  63733. #ifdef SQLITE_DEBUG

  63734. static int cursorHoldsMutex(BtCursor *p){

  63735.   return sqlite3_mutex_held(p->pBt->mutex);

  63736. }

  63737. 

  63738. /* Verify that the cursor and the BtShared agree about what is the current

  63739. ** database connetion. This is important in shared-cache mode. If the database 

  63740. ** connection pointers get out-of-sync, it is possible for routines like

  63741. ** btreeInitPage() to reference an stale connection pointer that references a

  63742. ** a connection that has already closed.  This routine is used inside assert()

  63743. ** statements only and for the purpose of double-checking that the btree code

  63744. ** does keep the database connection pointers up-to-date.

  63745. */

  63746. static int cursorOwnsBtShared(BtCursor *p){

  63747.   assert( cursorHoldsMutex(p) );

  63748.   return (p->pBtree->db==p->pBt->db);

  63749. }

  63750. #endif

  63751. 

  63752. /*

  63753. ** Invalidate the overflow cache of the cursor passed as the first argument.

  63754. ** on the shared btree structure pBt.

  63755. */

  63756. #define invalidateOverflowCache(pCur) (pCur->curFlags &= ~BTCF_ValidOvfl)

  63757. 

  63758. /*

  63759. ** Invalidate the overflow page-list cache for all cursors opened

  63760. ** on the shared btree structure pBt.

  63761. */

  63762. static void invalidateAllOverflowCache(BtShared *pBt){

  63763.   BtCursor *p;

  63764.   assert( sqlite3_mutex_held(pBt->mutex) );

  63765.   for(p=pBt->pCursor; p; p=p->pNext){

  63766.     invalidateOverflowCache(p);

  63767.   }

  63768. }

  63769. 

  63770. #ifndef SQLITE_OMIT_INCRBLOB

  63771. /*

  63772. ** This function is called before modifying the contents of a table

  63773. ** to invalidate any incrblob cursors that are open on the

  63774. ** row or one of the rows being modified.

  63775. **

  63776. ** If argument isClearTable is true, then the entire contents of the

  63777. ** table is about to be deleted. In this case invalidate all incrblob

  63778. ** cursors open on any row within the table with root-page pgnoRoot.

  63779. **

  63780. ** Otherwise, if argument isClearTable is false, then the row with

  63781. ** rowid iRow is being replaced or deleted. In this case invalidate

  63782. ** only those incrblob cursors open on that specific row.

  63783. */

  63784. static void invalidateIncrblobCursors(

  63785.   Btree *pBtree,          /* The database file to check */

  63786.   Pgno pgnoRoot,          /* The table that might be changing */

  63787.   i64 iRow,               /* The rowid that might be changing */

  63788.   int isClearTable        /* True if all rows are being deleted */

  63789. ){

  63790.   BtCursor *p;

  63791.   if( pBtree->hasIncrblobCur==0 ) return;

  63792.   assert( sqlite3BtreeHoldsMutex(pBtree) );

  63793.   pBtree->hasIncrblobCur = 0;

  63794.   for(p=pBtree->pBt->pCursor; p; p=p->pNext){

  63795.     if( (p->curFlags & BTCF_Incrblob)!=0 ){

  63796.       pBtree->hasIncrblobCur = 1;

  63797.       if( p->pgnoRoot==pgnoRoot && (isClearTable || p->info.nKey==iRow) ){

  63798.         p->eState = CURSOR_INVALID;

  63799.       }

  63800.     }

  63801.   }

  63802. }

  63803. 

  63804. #else

  63805.   /* Stub function when INCRBLOB is omitted */

  63806.   #define invalidateIncrblobCursors(w,x,y,z)

  63807. #endif /* SQLITE_OMIT_INCRBLOB */

  63808. 

  63809. /*

  63810. ** Set bit pgno of the BtShared.pHasContent bitvec. This is called 

  63811. ** when a page that previously contained data becomes a free-list leaf 

  63812. ** page.

  63813. **

  63814. ** The BtShared.pHasContent bitvec exists to work around an obscure

  63815. ** bug caused by the interaction of two useful IO optimizations surrounding

  63816. ** free-list leaf pages:

  63817. **

  63818. **   1) When all data is deleted from a page and the page becomes

  63819. **      a free-list leaf page, the page is not written to the database

  63820. **      (as free-list leaf pages contain no meaningful data). Sometimes

  63821. **      such a page is not even journalled (as it will not be modified,

  63822. **      why bother journalling it?).

  63823. **

  63824. **   2) When a free-list leaf page is reused, its content is not read

  63825. **      from the database or written to the journal file (why should it

  63826. **      be, if it is not at all meaningful?).

  63827. **

  63828. ** By themselves, these optimizations work fine and provide a handy

  63829. ** performance boost to bulk delete or insert operations. However, if

  63830. ** a page is moved to the free-list and then reused within the same

  63831. ** transaction, a problem comes up. If the page is not journalled when

  63832. ** it is moved to the free-list and it is also not journalled when it

  63833. ** is extracted from the free-list and reused, then the original data

  63834. ** may be lost. In the event of a rollback, it may not be possible

  63835. ** to restore the database to its original configuration.

  63836. **

  63837. ** The solution is the BtShared.pHasContent bitvec. Whenever a page is 

  63838. ** moved to become a free-list leaf page, the corresponding bit is

  63839. ** set in the bitvec. Whenever a leaf page is extracted from the free-list,

  63840. ** optimization 2 above is omitted if the corresponding bit is already

  63841. ** set in BtShared.pHasContent. The contents of the bitvec are cleared

  63842. ** at the end of every transaction.

  63843. */

  63844. static int btreeSetHasContent(BtShared *pBt, Pgno pgno){

  63845.   int rc = SQLITE_OK;

  63846.   if( !pBt->pHasContent ){

  63847.     assert( pgno<=pBt->nPage );

  63848.     pBt->pHasContent = sqlite3BitvecCreate(pBt->nPage);

  63849.     if( !pBt->pHasContent ){

  63850.       rc = SQLITE_NOMEM_BKPT;

  63851.     }

  63852.   }

  63853.   if( rc==SQLITE_OK && pgno<=sqlite3BitvecSize(pBt->pHasContent) ){

  63854.     rc = sqlite3BitvecSet(pBt->pHasContent, pgno);

  63855.   }

  63856.   return rc;

  63857. }

  63858. 

  63859. /*

  63860. ** Query the BtShared.pHasContent vector.

  63861. **

  63862. ** This function is called when a free-list leaf page is removed from the

  63863. ** free-list for reuse. It returns false if it is safe to retrieve the

  63864. ** page from the pager layer with the 'no-content' flag set. True otherwise.

  63865. */

  63866. static int btreeGetHasContent(BtShared *pBt, Pgno pgno){

  63867.   Bitvec *p = pBt->pHasContent;

  63868.   return (p && (pgno>sqlite3BitvecSize(p) || sqlite3BitvecTest(p, pgno)));

  63869. }

  63870. 

  63871. /*

  63872. ** Clear (destroy) the BtShared.pHasContent bitvec. This should be

  63873. ** invoked at the conclusion of each write-transaction.

  63874. */

  63875. static void btreeClearHasContent(BtShared *pBt){

  63876.   sqlite3BitvecDestroy(pBt->pHasContent);

  63877.   pBt->pHasContent = 0;

  63878. }

  63879. 

  63880. /*

  63881. ** Release all of the apPage[] pages for a cursor.

  63882. */

  63883. static void btreeReleaseAllCursorPages(BtCursor *pCur){

  63884.   int i;

  63885.   if( pCur->iPage>=0 ){

  63886.     for(i=0; i<pCur->iPage; i++){

  63887.       releasePageNotNull(pCur->apPage[i]);

  63888.     }

  63889.     releasePageNotNull(pCur->pPage);

  63890.     pCur->iPage = -1;

  63891.   }

  63892. }

  63893. 

  63894. /*

  63895. ** The cursor passed as the only argument must point to a valid entry

  63896. ** when this function is called (i.e. have eState==CURSOR_VALID). This

  63897. ** function saves the current cursor key in variables pCur->nKey and

  63898. ** pCur->pKey. SQLITE_OK is returned if successful or an SQLite error 

  63899. ** code otherwise.

  63900. **

  63901. ** If the cursor is open on an intkey table, then the integer key

  63902. ** (the rowid) is stored in pCur->nKey and pCur->pKey is left set to

  63903. ** NULL. If the cursor is open on a non-intkey table, then pCur->pKey is 

  63904. ** set to point to a malloced buffer pCur->nKey bytes in size containing 

  63905. ** the key.

  63906. */

  63907. static int saveCursorKey(BtCursor *pCur){

  63908.   int rc = SQLITE_OK;

  63909.   assert( CURSOR_VALID==pCur->eState );

  63910.   assert( 0==pCur->pKey );

  63911.   assert( cursorHoldsMutex(pCur) );

  63912. 

  63913.   if( pCur->curIntKey ){

  63914.     /* Only the rowid is required for a table btree */

  63915.     pCur->nKey = sqlite3BtreeIntegerKey(pCur);

  63916.   }else{

  63917.     /* For an index btree, save the complete key content. It is possible

  63918.     ** that the current key is corrupt. In that case, it is possible that

  63919.     ** the sqlite3VdbeRecordUnpack() function may overread the buffer by

  63920.     ** up to the size of 1 varint plus 1 8-byte value when the cursor 

  63921.     ** position is restored. Hence the 17 bytes of padding allocated 

  63922.     ** below. */

  63923.     void *pKey;

  63924.     pCur->nKey = sqlite3BtreePayloadSize(pCur);

  63925.     pKey = sqlite3Malloc( pCur->nKey + 9 + 8 );

  63926.     if( pKey ){

  63927.       rc = sqlite3BtreePayload(pCur, 0, (int)pCur->nKey, pKey);

  63928.       if( rc==SQLITE_OK ){

  63929.         memset(((u8*)pKey)+pCur->nKey, 0, 9+8);

  63930.         pCur->pKey = pKey;

  63931.       }else{

  63932.         sqlite3_free(pKey);

  63933.       }

  63934.     }else{

  63935.       rc = SQLITE_NOMEM_BKPT;

  63936.     }

  63937.   }

  63938.   assert( !pCur->curIntKey || !pCur->pKey );

  63939.   return rc;

  63940. }

  63941. 

  63942. /*

  63943. ** Save the current cursor position in the variables BtCursor.nKey 

  63944. ** and BtCursor.pKey. The cursor's state is set to CURSOR_REQUIRESEEK.

  63945. **

  63946. ** The caller must ensure that the cursor is valid (has eState==CURSOR_VALID)

  63947. ** prior to calling this routine.  

  63948. */

  63949. static int saveCursorPosition(BtCursor *pCur){

  63950.   int rc;

  63951. 

  63952.   assert( CURSOR_VALID==pCur->eState || CURSOR_SKIPNEXT==pCur->eState );

  63953.   assert( 0==pCur->pKey );

  63954.   assert( cursorHoldsMutex(pCur) );

  63955. 

  63956.   if( pCur->eState==CURSOR_SKIPNEXT ){

  63957.     pCur->eState = CURSOR_VALID;

  63958.   }else{

  63959.     pCur->skipNext = 0;

  63960.   }

  63961. 

  63962.   rc = saveCursorKey(pCur);

  63963.   if( rc==SQLITE_OK ){

  63964.     btreeReleaseAllCursorPages(pCur);

  63965.     pCur->eState = CURSOR_REQUIRESEEK;

  63966.   }

  63967. 

  63968.   pCur->curFlags &= ~(BTCF_ValidNKey|BTCF_ValidOvfl|BTCF_AtLast);

  63969.   return rc;

  63970. }

  63971. 

  63972. /* Forward reference */

  63973. static int SQLITE_NOINLINE saveCursorsOnList(BtCursor*,Pgno,BtCursor*);

  63974. 

  63975. /*

  63976. ** Save the positions of all cursors (except pExcept) that are open on

  63977. ** the table with root-page iRoot.  "Saving the cursor position" means that

  63978. ** the location in the btree is remembered in such a way that it can be

  63979. ** moved back to the same spot after the btree has been modified.  This

  63980. ** routine is called just before cursor pExcept is used to modify the

  63981. ** table, for example in BtreeDelete() or BtreeInsert().

  63982. **

  63983. ** If there are two or more cursors on the same btree, then all such 

  63984. ** cursors should have their BTCF_Multiple flag set.  The btreeCursor()

  63985. ** routine enforces that rule.  This routine only needs to be called in

  63986. ** the uncommon case when pExpect has the BTCF_Multiple flag set.

  63987. **

  63988. ** If pExpect!=NULL and if no other cursors are found on the same root-page,

  63989. ** then the BTCF_Multiple flag on pExpect is cleared, to avoid another

  63990. ** pointless call to this routine.

  63991. **

  63992. ** Implementation note:  This routine merely checks to see if any cursors

  63993. ** need to be saved.  It calls out to saveCursorsOnList() in the (unusual)

  63994. ** event that cursors are in need to being saved.

  63995. */

  63996. static int saveAllCursors(BtShared *pBt, Pgno iRoot, BtCursor *pExcept){

  63997.   BtCursor *p;

  63998.   assert( sqlite3_mutex_held(pBt->mutex) );

  63999.   assert( pExcept==0 || pExcept->pBt==pBt );

  64000.   for(p=pBt->pCursor; p; p=p->pNext){

  64001.     if( p!=pExcept && (0==iRoot || p->pgnoRoot==iRoot) ) break;

  64002.   }

  64003.   if( p ) return saveCursorsOnList(p, iRoot, pExcept);

  64004.   if( pExcept ) pExcept->curFlags &= ~BTCF_Multiple;

  64005.   return SQLITE_OK;

  64006. }

  64007. 

  64008. /* This helper routine to saveAllCursors does the actual work of saving

  64009. ** the cursors if and when a cursor is found that actually requires saving.

  64010. ** The common case is that no cursors need to be saved, so this routine is

  64011. ** broken out from its caller to avoid unnecessary stack pointer movement.

  64012. */

  64013. static int SQLITE_NOINLINE saveCursorsOnList(

  64014.   BtCursor *p,         /* The first cursor that needs saving */

  64015.   Pgno iRoot,          /* Only save cursor with this iRoot. Save all if zero */

  64016.   BtCursor *pExcept    /* Do not save this cursor */

  64017. ){

  64018.   do{

  64019.     if( p!=pExcept && (0==iRoot || p->pgnoRoot==iRoot) ){

  64020.       if( p->eState==CURSOR_VALID || p->eState==CURSOR_SKIPNEXT ){

  64021.         int rc = saveCursorPosition(p);

  64022.         if( SQLITE_OK!=rc ){

  64023.           return rc;

  64024.         }

  64025.       }else{

  64026.         testcase( p->iPage>=0 );

  64027.         btreeReleaseAllCursorPages(p);

  64028.       }

  64029.     }

  64030.     p = p->pNext;

  64031.   }while( p );

  64032.   return SQLITE_OK;

  64033. }

  64034. 

  64035. /*

  64036. ** Clear the current cursor position.

  64037. */

  64038. SQLITE_PRIVATE void sqlite3BtreeClearCursor(BtCursor *pCur){

  64039.   assert( cursorHoldsMutex(pCur) );

  64040.   sqlite3_free(pCur->pKey);

  64041.   pCur->pKey = 0;

  64042.   pCur->eState = CURSOR_INVALID;

  64043. }

  64044. 

  64045. /*

  64046. ** In this version of BtreeMoveto, pKey is a packed index record

  64047. ** such as is generated by the OP_MakeRecord opcode.  Unpack the

  64048. ** record and then call BtreeMovetoUnpacked() to do the work.

  64049. */

  64050. static int btreeMoveto(

  64051.   BtCursor *pCur,     /* Cursor open on the btree to be searched */

  64052.   const void *pKey,   /* Packed key if the btree is an index */

  64053.   i64 nKey,           /* Integer key for tables.  Size of pKey for indices */

  64054.   int bias,           /* Bias search to the high end */

  64055.   int *pRes           /* Write search results here */

  64056. ){

  64057.   int rc;                    /* Status code */

  64058.   UnpackedRecord *pIdxKey;   /* Unpacked index key */

  64059. 

  64060.   if( pKey ){

  64061.     KeyInfo *pKeyInfo = pCur->pKeyInfo;

  64062.     assert( nKey==(i64)(int)nKey );

  64063.     pIdxKey = sqlite3VdbeAllocUnpackedRecord(pKeyInfo);

  64064.     if( pIdxKey==0 ) return SQLITE_NOMEM_BKPT;

  64065.     sqlite3VdbeRecordUnpack(pKeyInfo, (int)nKey, pKey, pIdxKey);

  64066.     if( pIdxKey->nField==0 || pIdxKey->nField>pKeyInfo->nAllField ){

  64067.       rc = SQLITE_CORRUPT_BKPT;

  64068.       goto moveto_done;

  64069.     }

  64070.   }else{

  64071.     pIdxKey = 0;

  64072.   }

  64073.   rc = sqlite3BtreeMovetoUnpacked(pCur, pIdxKey, nKey, bias, pRes);

  64074. moveto_done:

  64075.   if( pIdxKey ){

  64076.     sqlite3DbFree(pCur->pKeyInfo->db, pIdxKey);

  64077.   }

  64078.   return rc;

  64079. }

  64080. 

  64081. /*

  64082. ** Restore the cursor to the position it was in (or as close to as possible)

  64083. ** when saveCursorPosition() was called. Note that this call deletes the 

  64084. ** saved position info stored by saveCursorPosition(), so there can be

  64085. ** at most one effective restoreCursorPosition() call after each 

  64086. ** saveCursorPosition().

  64087. */

  64088. static int btreeRestoreCursorPosition(BtCursor *pCur){

  64089.   int rc;

  64090.   int skipNext = 0;

  64091.   assert( cursorOwnsBtShared(pCur) );

  64092.   assert( pCur->eState>=CURSOR_REQUIRESEEK );

  64093.   if( pCur->eState==CURSOR_FAULT ){

  64094.     return pCur->skipNext;

  64095.   }

  64096.   pCur->eState = CURSOR_INVALID;

  64097.   if( sqlite3FaultSim(410) ){

  64098.     rc = SQLITE_IOERR;

  64099.   }else{

  64100.     rc = btreeMoveto(pCur, pCur->pKey, pCur->nKey, 0, &skipNext);

  64101.   }

  64102.   if( rc==SQLITE_OK ){

  64103.     sqlite3_free(pCur->pKey);

  64104.     pCur->pKey = 0;

  64105.     assert( pCur->eState==CURSOR_VALID || pCur->eState==CURSOR_INVALID );

  64106.     if( skipNext ) pCur->skipNext = skipNext;

  64107.     if( pCur->skipNext && pCur->eState==CURSOR_VALID ){

  64108.       pCur->eState = CURSOR_SKIPNEXT;

  64109.     }

  64110.   }

  64111.   return rc;

  64112. }

  64113. 

  64114. #define restoreCursorPosition(p) \

  64115.   (p->eState>=CURSOR_REQUIRESEEK ? \

  64116.          btreeRestoreCursorPosition(p) : \

  64117.          SQLITE_OK)

  64118. 

  64119. /*

  64120. ** Determine whether or not a cursor has moved from the position where

  64121. ** it was last placed, or has been invalidated for any other reason.

  64122. ** Cursors can move when the row they are pointing at is deleted out

  64123. ** from under them, for example.  Cursor might also move if a btree

  64124. ** is rebalanced.

  64125. **

  64126. ** Calling this routine with a NULL cursor pointer returns false.

  64127. **

  64128. ** Use the separate sqlite3BtreeCursorRestore() routine to restore a cursor

  64129. ** back to where it ought to be if this routine returns true.

  64130. */

  64131. SQLITE_PRIVATE int sqlite3BtreeCursorHasMoved(BtCursor *pCur){

  64132.   assert( EIGHT_BYTE_ALIGNMENT(pCur)

  64133.        || pCur==sqlite3BtreeFakeValidCursor() );

  64134.   assert( offsetof(BtCursor, eState)==0 );

  64135.   assert( sizeof(pCur->eState)==1 );

  64136.   return CURSOR_VALID != *(u8*)pCur;

  64137. }

  64138. 

  64139. /*

  64140. ** Return a pointer to a fake BtCursor object that will always answer

  64141. ** false to the sqlite3BtreeCursorHasMoved() routine above.  The fake

  64142. ** cursor returned must not be used with any other Btree interface.

  64143. */

  64144. SQLITE_PRIVATE BtCursor *sqlite3BtreeFakeValidCursor(void){

  64145.   static u8 fakeCursor = CURSOR_VALID;

  64146.   assert( offsetof(BtCursor, eState)==0 );

  64147.   return (BtCursor*)&fakeCursor;

  64148. }

  64149. 

  64150. /*

  64151. ** This routine restores a cursor back to its original position after it

  64152. ** has been moved by some outside activity (such as a btree rebalance or

  64153. ** a row having been deleted out from under the cursor).  

  64154. **

  64155. ** On success, the *pDifferentRow parameter is false if the cursor is left

  64156. ** pointing at exactly the same row.  *pDifferntRow is the row the cursor

  64157. ** was pointing to has been deleted, forcing the cursor to point to some

  64158. ** nearby row.

  64159. **

  64160. ** This routine should only be called for a cursor that just returned

  64161. ** TRUE from sqlite3BtreeCursorHasMoved().

  64162. */

  64163. SQLITE_PRIVATE int sqlite3BtreeCursorRestore(BtCursor *pCur, int *pDifferentRow){

  64164.   int rc;

  64165. 

  64166.   assert( pCur!=0 );

  64167.   assert( pCur->eState!=CURSOR_VALID );

  64168.   rc = restoreCursorPosition(pCur);

  64169.   if( rc ){

  64170.     *pDifferentRow = 1;

  64171.     return rc;

  64172.   }

  64173.   if( pCur->eState!=CURSOR_VALID ){

  64174.     *pDifferentRow = 1;

  64175.   }else{

  64176.     *pDifferentRow = 0;

  64177.   }

  64178.   return SQLITE_OK;

  64179. }

  64180. 

  64181. #ifdef SQLITE_ENABLE_CURSOR_HINTS

  64182. /*

  64183. ** Provide hints to the cursor.  The particular hint given (and the type

  64184. ** and number of the varargs parameters) is determined by the eHintType

  64185. ** parameter.  See the definitions of the BTREE_HINT_* macros for details.

  64186. */

  64187. SQLITE_PRIVATE void sqlite3BtreeCursorHint(BtCursor *pCur, int eHintType, ...){

  64188.   /* Used only by system that substitute their own storage engine */

  64189. }

  64190. #endif

  64191. 

  64192. /*

  64193. ** Provide flag hints to the cursor.

  64194. */

  64195. SQLITE_PRIVATE void sqlite3BtreeCursorHintFlags(BtCursor *pCur, unsigned x){

  64196.   assert( x==BTREE_SEEK_EQ || x==BTREE_BULKLOAD || x==0 );

  64197.   pCur->hints = x;

  64198. }

  64199. 

  64200. 

  64201. #ifndef SQLITE_OMIT_AUTOVACUUM

  64202. /*

  64203. ** Given a page number of a regular database page, return the page

  64204. ** number for the pointer-map page that contains the entry for the

  64205. ** input page number.

  64206. **

  64207. ** Return 0 (not a valid page) for pgno==1 since there is

  64208. ** no pointer map associated with page 1.  The integrity_check logic

  64209. ** requires that ptrmapPageno(*,1)!=1.

  64210. */

  64211. static Pgno ptrmapPageno(BtShared *pBt, Pgno pgno){

  64212.   int nPagesPerMapPage;

  64213.   Pgno iPtrMap, ret;

  64214.   assert( sqlite3_mutex_held(pBt->mutex) );

  64215.   if( pgno<2 ) return 0;

  64216.   nPagesPerMapPage = (pBt->usableSize/5)+1;

  64217.   iPtrMap = (pgno-2)/nPagesPerMapPage;

  64218.   ret = (iPtrMap*nPagesPerMapPage) + 2; 

  64219.   if( ret==PENDING_BYTE_PAGE(pBt) ){

  64220.     ret++;

  64221.   }

  64222.   return ret;

  64223. }

  64224. 

  64225. /*

  64226. ** Write an entry into the pointer map.

  64227. **

  64228. ** This routine updates the pointer map entry for page number 'key'

  64229. ** so that it maps to type 'eType' and parent page number 'pgno'.

  64230. **

  64231. ** If *pRC is initially non-zero (non-SQLITE_OK) then this routine is

  64232. ** a no-op.  If an error occurs, the appropriate error code is written

  64233. ** into *pRC.

  64234. */

  64235. static void ptrmapPut(BtShared *pBt, Pgno key, u8 eType, Pgno parent, int *pRC){

  64236.   DbPage *pDbPage;  /* The pointer map page */

  64237.   u8 *pPtrmap;      /* The pointer map data */

  64238.   Pgno iPtrmap;     /* The pointer map page number */

  64239.   int offset;       /* Offset in pointer map page */

  64240.   int rc;           /* Return code from subfunctions */

  64241. 

  64242.   if( *pRC ) return;

  64243. 

  64244.   assert( sqlite3_mutex_held(pBt->mutex) );

  64245.   /* The master-journal page number must never be used as a pointer map page */

  64246.   assert( 0==PTRMAP_ISPAGE(pBt, PENDING_BYTE_PAGE(pBt)) );

  64247. 

  64248.   assert( pBt->autoVacuum );

  64249.   if( key==0 ){

  64250.     *pRC = SQLITE_CORRUPT_BKPT;

  64251.     return;

  64252.   }

  64253.   iPtrmap = PTRMAP_PAGENO(pBt, key);

  64254.   rc = sqlite3PagerGet(pBt->pPager, iPtrmap, &pDbPage, 0);

  64255.   if( rc!=SQLITE_OK ){

  64256.     *pRC = rc;

  64257.     return;

  64258.   }

  64259.   if( ((char*)sqlite3PagerGetExtra(pDbPage))[0]!=0 ){

  64260.     /* The first byte of the extra data is the MemPage.isInit byte.

  64261.     ** If that byte is set, it means this page is also being used

  64262.     ** as a btree page. */

  64263.     *pRC = SQLITE_CORRUPT_BKPT;

  64264.     goto ptrmap_exit;

  64265.   }

  64266.   offset = PTRMAP_PTROFFSET(iPtrmap, key);

  64267.   if( offset<0 ){

  64268.     *pRC = SQLITE_CORRUPT_BKPT;

  64269.     goto ptrmap_exit;

  64270.   }

  64271.   assert( offset <= (int)pBt->usableSize-5 );

  64272.   pPtrmap = (u8 *)sqlite3PagerGetData(pDbPage);

  64273. 

  64274.   if( eType!=pPtrmap[offset] || get4byte(&pPtrmap[offset+1])!=parent ){

  64275.     TRACE(("PTRMAP_UPDATE: %d->(%d,%d)\n", key, eType, parent));

  64276.     *pRC= rc = sqlite3PagerWrite(pDbPage);

  64277.     if( rc==SQLITE_OK ){

  64278.       pPtrmap[offset] = eType;

  64279.       put4byte(&pPtrmap[offset+1], parent);

  64280.     }

  64281.   }

  64282. 

  64283. ptrmap_exit:

  64284.   sqlite3PagerUnref(pDbPage);

  64285. }

  64286. 

  64287. /*

  64288. ** Read an entry from the pointer map.

  64289. **

  64290. ** This routine retrieves the pointer map entry for page 'key', writing

  64291. ** the type and parent page number to *pEType and *pPgno respectively.

  64292. ** An error code is returned if something goes wrong, otherwise SQLITE_OK.

  64293. */

  64294. static int ptrmapGet(BtShared *pBt, Pgno key, u8 *pEType, Pgno *pPgno){

  64295.   DbPage *pDbPage;   /* The pointer map page */

  64296.   int iPtrmap;       /* Pointer map page index */

  64297.   u8 *pPtrmap;       /* Pointer map page data */

  64298.   int offset;        /* Offset of entry in pointer map */

  64299.   int rc;

  64300. 

  64301.   assert( sqlite3_mutex_held(pBt->mutex) );

  64302. 

  64303.   iPtrmap = PTRMAP_PAGENO(pBt, key);

  64304.   rc = sqlite3PagerGet(pBt->pPager, iPtrmap, &pDbPage, 0);

  64305.   if( rc!=0 ){

  64306.     return rc;

  64307.   }

  64308.   pPtrmap = (u8 *)sqlite3PagerGetData(pDbPage);

  64309. 

  64310.   offset = PTRMAP_PTROFFSET(iPtrmap, key);

  64311.   if( offset<0 ){

  64312.     sqlite3PagerUnref(pDbPage);

  64313.     return SQLITE_CORRUPT_BKPT;

  64314.   }

  64315.   assert( offset <= (int)pBt->usableSize-5 );

  64316.   assert( pEType!=0 );

  64317.   *pEType = pPtrmap[offset];

  64318.   if( pPgno ) *pPgno = get4byte(&pPtrmap[offset+1]);

  64319. 

  64320.   sqlite3PagerUnref(pDbPage);

  64321.   if( *pEType<1 || *pEType>5 ) return SQLITE_CORRUPT_PGNO(iPtrmap);

  64322.   return SQLITE_OK;

  64323. }

  64324. 

  64325. #else /* if defined SQLITE_OMIT_AUTOVACUUM */

  64326.   #define ptrmapPut(w,x,y,z,rc)

  64327.   #define ptrmapGet(w,x,y,z) SQLITE_OK

  64328.   #define ptrmapPutOvflPtr(x, y, z, rc)

  64329. #endif

  64330. 

  64331. /*

  64332. ** Given a btree page and a cell index (0 means the first cell on

  64333. ** the page, 1 means the second cell, and so forth) return a pointer

  64334. ** to the cell content.

  64335. **

  64336. ** findCellPastPtr() does the same except it skips past the initial

  64337. ** 4-byte child pointer found on interior pages, if there is one.

  64338. **

  64339. ** This routine works only for pages that do not contain overflow cells.

  64340. */

  64341. #define findCell(P,I) \

  64342.   ((P)->aData + ((P)->maskPage & get2byteAligned(&(P)->aCellIdx[2*(I)])))

  64343. #define findCellPastPtr(P,I) \

  64344.   ((P)->aDataOfst + ((P)->maskPage & get2byteAligned(&(P)->aCellIdx[2*(I)])))

  64345. 

  64346. 

  64347. /*

  64348. ** This is common tail processing for btreeParseCellPtr() and

  64349. ** btreeParseCellPtrIndex() for the case when the cell does not fit entirely

  64350. ** on a single B-tree page.  Make necessary adjustments to the CellInfo

  64351. ** structure.

  64352. */

  64353. static SQLITE_NOINLINE void btreeParseCellAdjustSizeForOverflow(

  64354.   MemPage *pPage,         /* Page containing the cell */

  64355.   u8 *pCell,              /* Pointer to the cell text. */

  64356.   CellInfo *pInfo         /* Fill in this structure */

  64357. ){

  64358.   /* If the payload will not fit completely on the local page, we have

  64359.   ** to decide how much to store locally and how much to spill onto

  64360.   ** overflow pages.  The strategy is to minimize the amount of unused

  64361.   ** space on overflow pages while keeping the amount of local storage

  64362.   ** in between minLocal and maxLocal.

  64363.   **

  64364.   ** Warning:  changing the way overflow payload is distributed in any

  64365.   ** way will result in an incompatible file format.

  64366.   */

  64367.   int minLocal;  /* Minimum amount of payload held locally */

  64368.   int maxLocal;  /* Maximum amount of payload held locally */

  64369.   int surplus;   /* Overflow payload available for local storage */

  64370. 

  64371.   minLocal = pPage->minLocal;

  64372.   maxLocal = pPage->maxLocal;

  64373.   surplus = minLocal + (pInfo->nPayload - minLocal)%(pPage->pBt->usableSize-4);

  64374.   testcase( surplus==maxLocal );

  64375.   testcase( surplus==maxLocal+1 );

  64376.   if( surplus <= maxLocal ){

  64377.     pInfo->nLocal = (u16)surplus;

  64378.   }else{

  64379.     pInfo->nLocal = (u16)minLocal;

  64380.   }

  64381.   pInfo->nSize = (u16)(&pInfo->pPayload[pInfo->nLocal] - pCell) + 4;

  64382. }

  64383. 

  64384. /*

  64385. ** The following routines are implementations of the MemPage.xParseCell()

  64386. ** method.

  64387. **

  64388. ** Parse a cell content block and fill in the CellInfo structure.

  64389. **

  64390. ** btreeParseCellPtr()        =>   table btree leaf nodes

  64391. ** btreeParseCellNoPayload()  =>   table btree internal nodes

  64392. ** btreeParseCellPtrIndex()   =>   index btree nodes

  64393. **

  64394. ** There is also a wrapper function btreeParseCell() that works for

  64395. ** all MemPage types and that references the cell by index rather than

  64396. ** by pointer.

  64397. */

  64398. static void btreeParseCellPtrNoPayload(

  64399.   MemPage *pPage,         /* Page containing the cell */

  64400.   u8 *pCell,              /* Pointer to the cell text. */

  64401.   CellInfo *pInfo         /* Fill in this structure */

  64402. ){

  64403.   assert( sqlite3_mutex_held(pPage->pBt->mutex) );

  64404.   assert( pPage->leaf==0 );

  64405.   assert( pPage->childPtrSize==4 );

  64406. #ifndef SQLITE_DEBUG

  64407.   UNUSED_PARAMETER(pPage);

  64408. #endif

  64409.   pInfo->nSize = 4 + getVarint(&pCell[4], (u64*)&pInfo->nKey);

  64410.   pInfo->nPayload = 0;

  64411.   pInfo->nLocal = 0;

  64412.   pInfo->pPayload = 0;

  64413.   return;

  64414. }

  64415. static void btreeParseCellPtr(

  64416.   MemPage *pPage,         /* Page containing the cell */

  64417.   u8 *pCell,              /* Pointer to the cell text. */

  64418.   CellInfo *pInfo         /* Fill in this structure */

  64419. ){

  64420.   u8 *pIter;              /* For scanning through pCell */

  64421.   u32 nPayload;           /* Number of bytes of cell payload */

  64422.   u64 iKey;               /* Extracted Key value */

  64423. 

  64424.   assert( sqlite3_mutex_held(pPage->pBt->mutex) );

  64425.   assert( pPage->leaf==0 || pPage->leaf==1 );

  64426.   assert( pPage->intKeyLeaf );

  64427.   assert( pPage->childPtrSize==0 );

  64428.   pIter = pCell;

  64429. 

  64430.   /* The next block of code is equivalent to:

  64431.   **

  64432.   **     pIter += getVarint32(pIter, nPayload);

  64433.   **

  64434.   ** The code is inlined to avoid a function call.

  64435.   */

  64436.   nPayload = *pIter;

  64437.   if( nPayload>=0x80 ){

  64438.     u8 *pEnd = &pIter[8];

  64439.     nPayload &= 0x7f;

  64440.     do{

  64441.       nPayload = (nPayload<<7) | (*++pIter & 0x7f);

  64442.     }while( (*pIter)>=0x80 && pIter<pEnd );

  64443.   }

  64444.   pIter++;

  64445. 

  64446.   /* The next block of code is equivalent to:

  64447.   **

  64448.   **     pIter += getVarint(pIter, (u64*)&pInfo->nKey);

  64449.   **

  64450.   ** The code is inlined to avoid a function call.

  64451.   */

  64452.   iKey = *pIter;

  64453.   if( iKey>=0x80 ){

  64454.     u8 *pEnd = &pIter[7];

  64455.     iKey &= 0x7f;

  64456.     while(1){

  64457.       iKey = (iKey<<7) | (*++pIter & 0x7f);

  64458.       if( (*pIter)<0x80 ) break;

  64459.       if( pIter>=pEnd ){

  64460.         iKey = (iKey<<8) | *++pIter;

  64461.         break;

  64462.       }

  64463.     }

  64464.   }

  64465.   pIter++;

  64466. 

  64467.   pInfo->nKey = *(i64*)&iKey;

  64468.   pInfo->nPayload = nPayload;

  64469.   pInfo->pPayload = pIter;

  64470.   testcase( nPayload==pPage->maxLocal );

  64471.   testcase( nPayload==pPage->maxLocal+1 );

  64472.   if( nPayload<=pPage->maxLocal ){

  64473.     /* This is the (easy) common case where the entire payload fits

  64474.     ** on the local page.  No overflow is required.

  64475.     */

  64476.     pInfo->nSize = nPayload + (u16)(pIter - pCell);

  64477.     if( pInfo->nSize<4 ) pInfo->nSize = 4;

  64478.     pInfo->nLocal = (u16)nPayload;

  64479.   }else{

  64480.     btreeParseCellAdjustSizeForOverflow(pPage, pCell, pInfo);

  64481.   }

  64482. }

  64483. static void btreeParseCellPtrIndex(

  64484.   MemPage *pPage,         /* Page containing the cell */

  64485.   u8 *pCell,              /* Pointer to the cell text. */

  64486.   CellInfo *pInfo         /* Fill in this structure */

  64487. ){

  64488.   u8 *pIter;              /* For scanning through pCell */

  64489.   u32 nPayload;           /* Number of bytes of cell payload */

  64490. 

  64491.   assert( sqlite3_mutex_held(pPage->pBt->mutex) );

  64492.   assert( pPage->leaf==0 || pPage->leaf==1 );

  64493.   assert( pPage->intKeyLeaf==0 );

  64494.   pIter = pCell + pPage->childPtrSize;

  64495.   nPayload = *pIter;

  64496.   if( nPayload>=0x80 ){

  64497.     u8 *pEnd = &pIter[8];

  64498.     nPayload &= 0x7f;

  64499.     do{

  64500.       nPayload = (nPayload<<7) | (*++pIter & 0x7f);

  64501.     }while( *(pIter)>=0x80 && pIter<pEnd );

  64502.   }

  64503.   pIter++;

  64504.   pInfo->nKey = nPayload;

  64505.   pInfo->nPayload = nPayload;

  64506.   pInfo->pPayload = pIter;

  64507.   testcase( nPayload==pPage->maxLocal );

  64508.   testcase( nPayload==pPage->maxLocal+1 );

  64509.   if( nPayload<=pPage->maxLocal ){

  64510.     /* This is the (easy) common case where the entire payload fits

  64511.     ** on the local page.  No overflow is required.

  64512.     */

  64513.     pInfo->nSize = nPayload + (u16)(pIter - pCell);

  64514.     if( pInfo->nSize<4 ) pInfo->nSize = 4;

  64515.     pInfo->nLocal = (u16)nPayload;

  64516.   }else{

  64517.     btreeParseCellAdjustSizeForOverflow(pPage, pCell, pInfo);

  64518.   }

  64519. }

  64520. static void btreeParseCell(

  64521.   MemPage *pPage,         /* Page containing the cell */

  64522.   int iCell,              /* The cell index.  First cell is 0 */

  64523.   CellInfo *pInfo         /* Fill in this structure */

  64524. ){

  64525.   pPage->xParseCell(pPage, findCell(pPage, iCell), pInfo);

  64526. }

  64527. 

  64528. /*

  64529. ** The following routines are implementations of the MemPage.xCellSize

  64530. ** method.

  64531. **

  64532. ** Compute the total number of bytes that a Cell needs in the cell

  64533. ** data area of the btree-page.  The return number includes the cell

  64534. ** data header and the local payload, but not any overflow page or

  64535. ** the space used by the cell pointer.

  64536. **

  64537. ** cellSizePtrNoPayload()    =>   table internal nodes

  64538. ** cellSizePtr()             =>   all index nodes & table leaf nodes

  64539. */

  64540. static u16 cellSizePtr(MemPage *pPage, u8 *pCell){

  64541.   u8 *pIter = pCell + pPage->childPtrSize; /* For looping over bytes of pCell */

  64542.   u8 *pEnd;                                /* End mark for a varint */

  64543.   u32 nSize;                               /* Size value to return */

  64544. 

  64545. #ifdef SQLITE_DEBUG

  64546.   /* The value returned by this function should always be the same as

  64547.   ** the (CellInfo.nSize) value found by doing a full parse of the

  64548.   ** cell. If SQLITE_DEBUG is defined, an assert() at the bottom of

  64549.   ** this function verifies that this invariant is not violated. */

  64550.   CellInfo debuginfo;

  64551.   pPage->xParseCell(pPage, pCell, &debuginfo);

  64552. #endif

  64553. 

  64554.   nSize = *pIter;

  64555.   if( nSize>=0x80 ){

  64556.     pEnd = &pIter[8];

  64557.     nSize &= 0x7f;

  64558.     do{

  64559.       nSize = (nSize<<7) | (*++pIter & 0x7f);

  64560.     }while( *(pIter)>=0x80 && pIter<pEnd );

  64561.   }

  64562.   pIter++;

  64563.   if( pPage->intKey ){

  64564.     /* pIter now points at the 64-bit integer key value, a variable length 

  64565.     ** integer. The following block moves pIter to point at the first byte

  64566.     ** past the end of the key value. */

  64567.     pEnd = &pIter[9];

  64568.     while( (*pIter++)&0x80 && pIter<pEnd );

  64569.   }

  64570.   testcase( nSize==pPage->maxLocal );

  64571.   testcase( nSize==pPage->maxLocal+1 );

  64572.   if( nSize<=pPage->maxLocal ){

  64573.     nSize += (u32)(pIter - pCell);

  64574.     if( nSize<4 ) nSize = 4;

  64575.   }else{

  64576.     int minLocal = pPage->minLocal;

  64577.     nSize = minLocal + (nSize - minLocal) % (pPage->pBt->usableSize - 4);

  64578.     testcase( nSize==pPage->maxLocal );

  64579.     testcase( nSize==pPage->maxLocal+1 );

  64580.     if( nSize>pPage->maxLocal ){

  64581.       nSize = minLocal;

  64582.     }

  64583.     nSize += 4 + (u16)(pIter - pCell);

  64584.   }

  64585.   assert( nSize==debuginfo.nSize || CORRUPT_DB );

  64586.   return (u16)nSize;

  64587. }

  64588. static u16 cellSizePtrNoPayload(MemPage *pPage, u8 *pCell){

  64589.   u8 *pIter = pCell + 4; /* For looping over bytes of pCell */

  64590.   u8 *pEnd;              /* End mark for a varint */

  64591. 

  64592. #ifdef SQLITE_DEBUG

  64593.   /* The value returned by this function should always be the same as

  64594.   ** the (CellInfo.nSize) value found by doing a full parse of the

  64595.   ** cell. If SQLITE_DEBUG is defined, an assert() at the bottom of

  64596.   ** this function verifies that this invariant is not violated. */

  64597.   CellInfo debuginfo;

  64598.   pPage->xParseCell(pPage, pCell, &debuginfo);

  64599. #else

  64600.   UNUSED_PARAMETER(pPage);

  64601. #endif

  64602. 

  64603.   assert( pPage->childPtrSize==4 );

  64604.   pEnd = pIter + 9;

  64605.   while( (*pIter++)&0x80 && pIter<pEnd );

  64606.   assert( debuginfo.nSize==(u16)(pIter - pCell) || CORRUPT_DB );

  64607.   return (u16)(pIter - pCell);

  64608. }

  64609. 

  64610. 

  64611. #ifdef SQLITE_DEBUG

  64612. /* This variation on cellSizePtr() is used inside of assert() statements

  64613. ** only. */

  64614. static u16 cellSize(MemPage *pPage, int iCell){

  64615.   return pPage->xCellSize(pPage, findCell(pPage, iCell));

  64616. }

  64617. #endif

  64618. 

  64619. #ifndef SQLITE_OMIT_AUTOVACUUM

  64620. /*

  64621. ** The cell pCell is currently part of page pSrc but will ultimately be part

  64622. ** of pPage.  (pSrc and pPager are often the same.)  If pCell contains a

  64623. ** pointer to an overflow page, insert an entry into the pointer-map for

  64624. ** the overflow page that will be valid after pCell has been moved to pPage.

  64625. */

  64626. static void ptrmapPutOvflPtr(MemPage *pPage, MemPage *pSrc, u8 *pCell,int *pRC){

  64627.   CellInfo info;

  64628.   if( *pRC ) return;

  64629.   assert( pCell!=0 );

  64630.   pPage->xParseCell(pPage, pCell, &info);

  64631.   if( info.nLocal<info.nPayload ){

  64632.     Pgno ovfl;

  64633.     if( SQLITE_WITHIN(pSrc->aDataEnd, pCell, pCell+info.nLocal) ){

  64634.       testcase( pSrc!=pPage );

  64635.       *pRC = SQLITE_CORRUPT_BKPT;

  64636.       return;

  64637.     }

  64638.     ovfl = get4byte(&pCell[info.nSize-4]);

  64639.     ptrmapPut(pPage->pBt, ovfl, PTRMAP_OVERFLOW1, pPage->pgno, pRC);

  64640.   }

  64641. }

  64642. #endif

  64643. 

  64644. 

  64645. /*

  64646. ** Defragment the page given. This routine reorganizes cells within the

  64647. ** page so that there are no free-blocks on the free-block list.

  64648. **

  64649. ** Parameter nMaxFrag is the maximum amount of fragmented space that may be

  64650. ** present in the page after this routine returns.

  64651. **

  64652. ** EVIDENCE-OF: R-44582-60138 SQLite may from time to time reorganize a

  64653. ** b-tree page so that there are no freeblocks or fragment bytes, all

  64654. ** unused bytes are contained in the unallocated space region, and all

  64655. ** cells are packed tightly at the end of the page.

  64656. */

  64657. static int defragmentPage(MemPage *pPage, int nMaxFrag){

  64658.   int i;                     /* Loop counter */

  64659.   int pc;                    /* Address of the i-th cell */

  64660.   int hdr;                   /* Offset to the page header */

  64661.   int size;                  /* Size of a cell */

  64662.   int usableSize;            /* Number of usable bytes on a page */

  64663.   int cellOffset;            /* Offset to the cell pointer array */

  64664.   int cbrk;                  /* Offset to the cell content area */

  64665.   int nCell;                 /* Number of cells on the page */

  64666.   unsigned char *data;       /* The page data */

  64667.   unsigned char *temp;       /* Temp area for cell content */

  64668.   unsigned char *src;        /* Source of content */

  64669.   int iCellFirst;            /* First allowable cell index */

  64670.   int iCellLast;             /* Last possible cell index */

  64671. 

  64672.   assert( sqlite3PagerIswriteable(pPage->pDbPage) );

  64673.   assert( pPage->pBt!=0 );

  64674.   assert( pPage->pBt->usableSize <= SQLITE_MAX_PAGE_SIZE );

  64675.   assert( pPage->nOverflow==0 );

  64676.   assert( sqlite3_mutex_held(pPage->pBt->mutex) );

  64677.   temp = 0;

  64678.   src = data = pPage->aData;

  64679.   hdr = pPage->hdrOffset;

  64680.   cellOffset = pPage->cellOffset;

  64681.   nCell = pPage->nCell;

  64682.   assert( nCell==get2byte(&data[hdr+3]) || CORRUPT_DB );

  64683.   iCellFirst = cellOffset + 2*nCell;

  64684.   usableSize = pPage->pBt->usableSize;

  64685. 

  64686.   /* This block handles pages with two or fewer free blocks and nMaxFrag

  64687.   ** or fewer fragmented bytes. In this case it is faster to move the

  64688.   ** two (or one) blocks of cells using memmove() and add the required

  64689.   ** offsets to each pointer in the cell-pointer array than it is to 

  64690.   ** reconstruct the entire page.  */

  64691.   if( (int)data[hdr+7]<=nMaxFrag ){

  64692.     int iFree = get2byte(&data[hdr+1]);

  64693.     if( iFree>usableSize-4 ) return SQLITE_CORRUPT_PAGE(pPage);

  64694.     if( iFree ){

  64695.       int iFree2 = get2byte(&data[iFree]);

  64696.       if( iFree2>usableSize-4 ) return SQLITE_CORRUPT_PAGE(pPage);

  64697.       if( 0==iFree2 || (data[iFree2]==0 && data[iFree2+1]==0) ){

  64698.         u8 *pEnd = &data[cellOffset + nCell*2];

  64699.         u8 *pAddr;

  64700.         int sz2 = 0;

  64701.         int sz = get2byte(&data[iFree+2]);

  64702.         int top = get2byte(&data[hdr+5]);

  64703.         if( top>=iFree ){

  64704.           return SQLITE_CORRUPT_PAGE(pPage);

  64705.         }

  64706.         if( iFree2 ){

  64707.           if( iFree+sz>iFree2 ) return SQLITE_CORRUPT_PAGE(pPage);

  64708.           sz2 = get2byte(&data[iFree2+2]);

  64709.           if( iFree2+sz2 > usableSize ) return SQLITE_CORRUPT_PAGE(pPage);

  64710.           memmove(&data[iFree+sz+sz2], &data[iFree+sz], iFree2-(iFree+sz));

  64711.           sz += sz2;

  64712.         }else if( iFree+sz>usableSize ){

  64713.           return SQLITE_CORRUPT_PAGE(pPage);

  64714.         }

  64715. 

  64716.         cbrk = top+sz;

  64717.         assert( cbrk+(iFree-top) <= usableSize );

  64718.         memmove(&data[cbrk], &data[top], iFree-top);

  64719.         for(pAddr=&data[cellOffset]; pAddr<pEnd; pAddr+=2){

  64720.           pc = get2byte(pAddr);

  64721.           if( pc<iFree ){ put2byte(pAddr, pc+sz); }

  64722.           else if( pc<iFree2 ){ put2byte(pAddr, pc+sz2); }

  64723.         }

  64724.         goto defragment_out;

  64725.       }

  64726.     }

  64727.   }

  64728. 

  64729.   cbrk = usableSize;

  64730.   iCellLast = usableSize - 4;

  64731.   for(i=0; i<nCell; i++){

  64732.     u8 *pAddr;     /* The i-th cell pointer */

  64733.     pAddr = &data[cellOffset + i*2];

  64734.     pc = get2byte(pAddr);

  64735.     testcase( pc==iCellFirst );

  64736.     testcase( pc==iCellLast );

  64737.     /* These conditions have already been verified in btreeInitPage()

  64738.     ** if PRAGMA cell_size_check=ON.

  64739.     */

  64740.     if( pc<iCellFirst || pc>iCellLast ){

  64741.       return SQLITE_CORRUPT_PAGE(pPage);

  64742.     }

  64743.     assert( pc>=iCellFirst && pc<=iCellLast );

  64744.     size = pPage->xCellSize(pPage, &src[pc]);

  64745.     cbrk -= size;

  64746.     if( cbrk<iCellFirst || pc+size>usableSize ){

  64747.       return SQLITE_CORRUPT_PAGE(pPage);

  64748.     }

  64749.     assert( cbrk+size<=usableSize && cbrk>=iCellFirst );

  64750.     testcase( cbrk+size==usableSize );

  64751.     testcase( pc+size==usableSize );

  64752.     put2byte(pAddr, cbrk);

  64753.     if( temp==0 ){

  64754.       int x;

  64755.       if( cbrk==pc ) continue;

  64756.       temp = sqlite3PagerTempSpace(pPage->pBt->pPager);

  64757.       x = get2byte(&data[hdr+5]);

  64758.       memcpy(&temp[x], &data[x], (cbrk+size) - x);

  64759.       src = temp;

  64760.     }

  64761.     memcpy(&data[cbrk], &src[pc], size);

  64762.   }

  64763.   data[hdr+7] = 0;

  64764. 

  64765.  defragment_out:

  64766.   assert( pPage->nFree>=0 );

  64767.   if( data[hdr+7]+cbrk-iCellFirst!=pPage->nFree ){

  64768.     return SQLITE_CORRUPT_PAGE(pPage);

  64769.   }

  64770.   assert( cbrk>=iCellFirst );

  64771.   put2byte(&data[hdr+5], cbrk);

  64772.   data[hdr+1] = 0;

  64773.   data[hdr+2] = 0;

  64774.   memset(&data[iCellFirst], 0, cbrk-iCellFirst);

  64775.   assert( sqlite3PagerIswriteable(pPage->pDbPage) );

  64776.   return SQLITE_OK;

  64777. }

  64778. 

  64779. /*

  64780. ** Search the free-list on page pPg for space to store a cell nByte bytes in

  64781. ** size. If one can be found, return a pointer to the space and remove it

  64782. ** from the free-list.

  64783. **

  64784. ** If no suitable space can be found on the free-list, return NULL.

  64785. **

  64786. ** This function may detect corruption within pPg.  If corruption is

  64787. ** detected then *pRc is set to SQLITE_CORRUPT and NULL is returned.

  64788. **

  64789. ** Slots on the free list that are between 1 and 3 bytes larger than nByte

  64790. ** will be ignored if adding the extra space to the fragmentation count

  64791. ** causes the fragmentation count to exceed 60.

  64792. */

  64793. static u8 *pageFindSlot(MemPage *pPg, int nByte, int *pRc){

  64794.   const int hdr = pPg->hdrOffset;            /* Offset to page header */

  64795.   u8 * const aData = pPg->aData;             /* Page data */

  64796.   int iAddr = hdr + 1;                       /* Address of ptr to pc */

  64797.   int pc = get2byte(&aData[iAddr]);          /* Address of a free slot */

  64798.   int x;                                     /* Excess size of the slot */

  64799.   int maxPC = pPg->pBt->usableSize - nByte;  /* Max address for a usable slot */

  64800.   int size;                                  /* Size of the free slot */

  64801. 

  64802.   assert( pc>0 );

  64803.   while( pc<=maxPC ){

  64804.     /* EVIDENCE-OF: R-22710-53328 The third and fourth bytes of each

  64805.     ** freeblock form a big-endian integer which is the size of the freeblock

  64806.     ** in bytes, including the 4-byte header. */

  64807.     size = get2byte(&aData[pc+2]);

  64808.     if( (x = size - nByte)>=0 ){

  64809.       testcase( x==4 );

  64810.       testcase( x==3 );

  64811.       if( x<4 ){

  64812.         /* EVIDENCE-OF: R-11498-58022 In a well-formed b-tree page, the total

  64813.         ** number of bytes in fragments may not exceed 60. */

  64814.         if( aData[hdr+7]>57 ) return 0;

  64815. 

  64816.         /* Remove the slot from the free-list. Update the number of

  64817.         ** fragmented bytes within the page. */

  64818.         memcpy(&aData[iAddr], &aData[pc], 2);

  64819.         aData[hdr+7] += (u8)x;

  64820.       }else if( x+pc > maxPC ){

  64821.         /* This slot extends off the end of the usable part of the page */

  64822.         *pRc = SQLITE_CORRUPT_PAGE(pPg);

  64823.         return 0;

  64824.       }else{

  64825.         /* The slot remains on the free-list. Reduce its size to account

  64826.         ** for the portion used by the new allocation. */

  64827.         put2byte(&aData[pc+2], x);

  64828.       }

  64829.       return &aData[pc + x];

  64830.     }

  64831.     iAddr = pc;

  64832.     pc = get2byte(&aData[pc]);

  64833.     if( pc<=iAddr+size ){

  64834.       if( pc ){

  64835.         /* The next slot in the chain is not past the end of the current slot */

  64836.         *pRc = SQLITE_CORRUPT_PAGE(pPg);

  64837.       }

  64838.       return 0;

  64839.     }

  64840.   }

  64841.   if( pc>maxPC+nByte-4 ){

  64842.     /* The free slot chain extends off the end of the page */

  64843.     *pRc = SQLITE_CORRUPT_PAGE(pPg);

  64844.   }

  64845.   return 0;

  64846. }

  64847. 

  64848. /*

  64849. ** Allocate nByte bytes of space from within the B-Tree page passed

  64850. ** as the first argument. Write into *pIdx the index into pPage->aData[]

  64851. ** of the first byte of allocated space. Return either SQLITE_OK or

  64852. ** an error code (usually SQLITE_CORRUPT).

  64853. **

  64854. ** The caller guarantees that there is sufficient space to make the

  64855. ** allocation.  This routine might need to defragment in order to bring

  64856. ** all the space together, however.  This routine will avoid using

  64857. ** the first two bytes past the cell pointer area since presumably this

  64858. ** allocation is being made in order to insert a new cell, so we will

  64859. ** also end up needing a new cell pointer.

  64860. */

  64861. static int allocateSpace(MemPage *pPage, int nByte, int *pIdx){

  64862.   const int hdr = pPage->hdrOffset;    /* Local cache of pPage->hdrOffset */

  64863.   u8 * const data = pPage->aData;      /* Local cache of pPage->aData */

  64864.   int top;                             /* First byte of cell content area */

  64865.   int rc = SQLITE_OK;                  /* Integer return code */

  64866.   int gap;        /* First byte of gap between cell pointers and cell content */

  64867.   

  64868.   assert( sqlite3PagerIswriteable(pPage->pDbPage) );

  64869.   assert( pPage->pBt );

  64870.   assert( sqlite3_mutex_held(pPage->pBt->mutex) );

  64871.   assert( nByte>=0 );  /* Minimum cell size is 4 */

  64872.   assert( pPage->nFree>=nByte );

  64873.   assert( pPage->nOverflow==0 );

  64874.   assert( nByte < (int)(pPage->pBt->usableSize-8) );

  64875. 

  64876.   assert( pPage->cellOffset == hdr + 12 - 4*pPage->leaf );

  64877.   gap = pPage->cellOffset + 2*pPage->nCell;

  64878.   assert( gap<=65536 );

  64879.   /* EVIDENCE-OF: R-29356-02391 If the database uses a 65536-byte page size

  64880.   ** and the reserved space is zero (the usual value for reserved space)

  64881.   ** then the cell content offset of an empty page wants to be 65536.

  64882.   ** However, that integer is too large to be stored in a 2-byte unsigned

  64883.   ** integer, so a value of 0 is used in its place. */

  64884.   top = get2byte(&data[hdr+5]);

  64885.   assert( top<=(int)pPage->pBt->usableSize ); /* by btreeComputeFreeSpace() */

  64886.   if( gap>top ){

  64887.     if( top==0 && pPage->pBt->usableSize==65536 ){

  64888.       top = 65536;

  64889.     }else{

  64890.       return SQLITE_CORRUPT_PAGE(pPage);

  64891.     }

  64892.   }

  64893. 

  64894.   /* If there is enough space between gap and top for one more cell pointer,

  64895.   ** and if the freelist is not empty, then search the

  64896.   ** freelist looking for a slot big enough to satisfy the request.

  64897.   */

  64898.   testcase( gap+2==top );

  64899.   testcase( gap+1==top );

  64900.   testcase( gap==top );

  64901.   if( (data[hdr+2] || data[hdr+1]) && gap+2<=top ){

  64902.     u8 *pSpace = pageFindSlot(pPage, nByte, &rc);

  64903.     if( pSpace ){

  64904.       assert( pSpace>=data && (pSpace - data)<65536 );

  64905.       *pIdx = (int)(pSpace - data);

  64906.       return SQLITE_OK;

  64907.     }else if( rc ){

  64908.       return rc;

  64909.     }

  64910.   }

  64911. 

  64912.   /* The request could not be fulfilled using a freelist slot.  Check

  64913.   ** to see if defragmentation is necessary.

  64914.   */

  64915.   testcase( gap+2+nByte==top );

  64916.   if( gap+2+nByte>top ){

  64917.     assert( pPage->nCell>0 || CORRUPT_DB );

  64918.     assert( pPage->nFree>=0 );

  64919.     rc = defragmentPage(pPage, MIN(4, pPage->nFree - (2+nByte)));

  64920.     if( rc ) return rc;

  64921.     top = get2byteNotZero(&data[hdr+5]);

  64922.     assert( gap+2+nByte<=top );

  64923.   }

  64924. 

  64925. 

  64926.   /* Allocate memory from the gap in between the cell pointer array

  64927.   ** and the cell content area.  The btreeComputeFreeSpace() call has already

  64928.   ** validated the freelist.  Given that the freelist is valid, there

  64929.   ** is no way that the allocation can extend off the end of the page.

  64930.   ** The assert() below verifies the previous sentence.

  64931.   */

  64932.   top -= nByte;

  64933.   put2byte(&data[hdr+5], top);

  64934.   assert( top+nByte <= (int)pPage->pBt->usableSize );

  64935.   *pIdx = top;

  64936.   return SQLITE_OK;

  64937. }

  64938. 

  64939. /*

  64940. ** Return a section of the pPage->aData to the freelist.

  64941. ** The first byte of the new free block is pPage->aData[iStart]

  64942. ** and the size of the block is iSize bytes.

  64943. **

  64944. ** Adjacent freeblocks are coalesced.

  64945. **

  64946. ** Even though the freeblock list was checked by btreeComputeFreeSpace(),

  64947. ** that routine will not detect overlap between cells or freeblocks.  Nor

  64948. ** does it detect cells or freeblocks that encrouch into the reserved bytes

  64949. ** at the end of the page.  So do additional corruption checks inside this

  64950. ** routine and return SQLITE_CORRUPT if any problems are found.

  64951. */

  64952. static int freeSpace(MemPage *pPage, u16 iStart, u16 iSize){

  64953.   u16 iPtr;                             /* Address of ptr to next freeblock */

  64954.   u16 iFreeBlk;                         /* Address of the next freeblock */

  64955.   u8 hdr;                               /* Page header size.  0 or 100 */

  64956.   u8 nFrag = 0;                         /* Reduction in fragmentation */

  64957.   u16 iOrigSize = iSize;                /* Original value of iSize */

  64958.   u16 x;                                /* Offset to cell content area */

  64959.   u32 iEnd = iStart + iSize;            /* First byte past the iStart buffer */

  64960.   unsigned char *data = pPage->aData;   /* Page content */

  64961. 

  64962.   assert( pPage->pBt!=0 );

  64963.   assert( sqlite3PagerIswriteable(pPage->pDbPage) );

  64964.   assert( CORRUPT_DB || iStart>=pPage->hdrOffset+6+pPage->childPtrSize );

  64965.   assert( CORRUPT_DB || iEnd <= pPage->pBt->usableSize );

  64966.   assert( sqlite3_mutex_held(pPage->pBt->mutex) );

  64967.   assert( iSize>=4 );   /* Minimum cell size is 4 */

  64968.   assert( iStart<=pPage->pBt->usableSize-4 );

  64969. 

  64970.   /* The list of freeblocks must be in ascending order.  Find the 

  64971.   ** spot on the list where iStart should be inserted.

  64972.   */

  64973.   hdr = pPage->hdrOffset;

  64974.   iPtr = hdr + 1;

  64975.   if( data[iPtr+1]==0 && data[iPtr]==0 ){

  64976.     iFreeBlk = 0;  /* Shortcut for the case when the freelist is empty */

  64977.   }else{

  64978.     while( (iFreeBlk = get2byte(&data[iPtr]))<iStart ){

  64979.       if( iFreeBlk<iPtr+4 ){

  64980.         if( iFreeBlk==0 ) break;

  64981.         return SQLITE_CORRUPT_PAGE(pPage);

  64982.       }

  64983.       iPtr = iFreeBlk;

  64984.     }

  64985.     if( iFreeBlk>pPage->pBt->usableSize-4 ){

  64986.       return SQLITE_CORRUPT_PAGE(pPage);

  64987.     }

  64988.     assert( iFreeBlk>iPtr || iFreeBlk==0 );

  64989.   

  64990.     /* At this point:

  64991.     **    iFreeBlk:   First freeblock after iStart, or zero if none

  64992.     **    iPtr:       The address of a pointer to iFreeBlk

  64993.     **

  64994.     ** Check to see if iFreeBlk should be coalesced onto the end of iStart.

  64995.     */

  64996.     if( iFreeBlk && iEnd+3>=iFreeBlk ){

  64997.       nFrag = iFreeBlk - iEnd;

  64998.       if( iEnd>iFreeBlk ) return SQLITE_CORRUPT_PAGE(pPage);

  64999.       iEnd = iFreeBlk + get2byte(&data[iFreeBlk+2]);

  65000.       if( iEnd > pPage->pBt->usableSize ){

  65001.         return SQLITE_CORRUPT_PAGE(pPage);

  65002.       }

  65003.       iSize = iEnd - iStart;

  65004.       iFreeBlk = get2byte(&data[iFreeBlk]);

  65005.     }

  65006.   

  65007.     /* If iPtr is another freeblock (that is, if iPtr is not the freelist

  65008.     ** pointer in the page header) then check to see if iStart should be

  65009.     ** coalesced onto the end of iPtr.

  65010.     */

  65011.     if( iPtr>hdr+1 ){

  65012.       int iPtrEnd = iPtr + get2byte(&data[iPtr+2]);

  65013.       if( iPtrEnd+3>=iStart ){

  65014.         if( iPtrEnd>iStart ) return SQLITE_CORRUPT_PAGE(pPage);

  65015.         nFrag += iStart - iPtrEnd;

  65016.         iSize = iEnd - iPtr;

  65017.         iStart = iPtr;

  65018.       }

  65019.     }

  65020.     if( nFrag>data[hdr+7] ) return SQLITE_CORRUPT_PAGE(pPage);

  65021.     data[hdr+7] -= nFrag;

  65022.   }

  65023.   x = get2byte(&data[hdr+5]);

  65024.   if( iStart<=x ){

  65025.     /* The new freeblock is at the beginning of the cell content area,

  65026.     ** so just extend the cell content area rather than create another

  65027.     ** freelist entry */

  65028.     if( iStart<x || iPtr!=hdr+1 ) return SQLITE_CORRUPT_PAGE(pPage);

  65029.     put2byte(&data[hdr+1], iFreeBlk);

  65030.     put2byte(&data[hdr+5], iEnd);

  65031.   }else{

  65032.     /* Insert the new freeblock into the freelist */

  65033.     put2byte(&data[iPtr], iStart);

  65034.   }

  65035.   if( pPage->pBt->btsFlags & BTS_FAST_SECURE ){

  65036.     /* Overwrite deleted information with zeros when the secure_delete

  65037.     ** option is enabled */

  65038.     memset(&data[iStart], 0, iSize);

  65039.   }

  65040.   put2byte(&data[iStart], iFreeBlk);

  65041.   put2byte(&data[iStart+2], iSize);

  65042.   pPage->nFree += iOrigSize;

  65043.   return SQLITE_OK;

  65044. }

  65045. 

  65046. /*

  65047. ** Decode the flags byte (the first byte of the header) for a page

  65048. ** and initialize fields of the MemPage structure accordingly.

  65049. **

  65050. ** Only the following combinations are supported.  Anything different

  65051. ** indicates a corrupt database files:

  65052. **

  65053. **         PTF_ZERODATA

  65054. **         PTF_ZERODATA | PTF_LEAF

  65055. **         PTF_LEAFDATA | PTF_INTKEY

  65056. **         PTF_LEAFDATA | PTF_INTKEY | PTF_LEAF

  65057. */

  65058. static int decodeFlags(MemPage *pPage, int flagByte){

  65059.   BtShared *pBt;     /* A copy of pPage->pBt */

  65060. 

  65061.   assert( pPage->hdrOffset==(pPage->pgno==1 ? 100 : 0) );

  65062.   assert( sqlite3_mutex_held(pPage->pBt->mutex) );

  65063.   pPage->leaf = (u8)(flagByte>>3);  assert( PTF_LEAF == 1<<3 );

  65064.   flagByte &= ~PTF_LEAF;

  65065.   pPage->childPtrSize = 4-4*pPage->leaf;

  65066.   pPage->xCellSize = cellSizePtr;

  65067.   pBt = pPage->pBt;

  65068.   if( flagByte==(PTF_LEAFDATA | PTF_INTKEY) ){

  65069.     /* EVIDENCE-OF: R-07291-35328 A value of 5 (0x05) means the page is an

  65070.     ** interior table b-tree page. */

  65071.     assert( (PTF_LEAFDATA|PTF_INTKEY)==5 );

  65072.     /* EVIDENCE-OF: R-26900-09176 A value of 13 (0x0d) means the page is a

  65073.     ** leaf table b-tree page. */

  65074.     assert( (PTF_LEAFDATA|PTF_INTKEY|PTF_LEAF)==13 );

  65075.     pPage->intKey = 1;

  65076.     if( pPage->leaf ){

  65077.       pPage->intKeyLeaf = 1;

  65078.       pPage->xParseCell = btreeParseCellPtr;

  65079.     }else{

  65080.       pPage->intKeyLeaf = 0;

  65081.       pPage->xCellSize = cellSizePtrNoPayload;

  65082.       pPage->xParseCell = btreeParseCellPtrNoPayload;

  65083.     }

  65084.     pPage->maxLocal = pBt->maxLeaf;

  65085.     pPage->minLocal = pBt->minLeaf;

  65086.   }else if( flagByte==PTF_ZERODATA ){

  65087.     /* EVIDENCE-OF: R-43316-37308 A value of 2 (0x02) means the page is an

  65088.     ** interior index b-tree page. */

  65089.     assert( (PTF_ZERODATA)==2 );

  65090.     /* EVIDENCE-OF: R-59615-42828 A value of 10 (0x0a) means the page is a

  65091.     ** leaf index b-tree page. */

  65092.     assert( (PTF_ZERODATA|PTF_LEAF)==10 );

  65093.     pPage->intKey = 0;

  65094.     pPage->intKeyLeaf = 0;

  65095.     pPage->xParseCell = btreeParseCellPtrIndex;

  65096.     pPage->maxLocal = pBt->maxLocal;

  65097.     pPage->minLocal = pBt->minLocal;

  65098.   }else{

  65099.     /* EVIDENCE-OF: R-47608-56469 Any other value for the b-tree page type is

  65100.     ** an error. */

  65101.     return SQLITE_CORRUPT_PAGE(pPage);

  65102.   }

  65103.   pPage->max1bytePayload = pBt->max1bytePayload;

  65104.   return SQLITE_OK;

  65105. }

  65106. 

  65107. /*

  65108. ** Compute the amount of freespace on the page.  In other words, fill

  65109. ** in the pPage->nFree field.

  65110. */

  65111. static int btreeComputeFreeSpace(MemPage *pPage){

  65112.   int pc;            /* Address of a freeblock within pPage->aData[] */

  65113.   u8 hdr;            /* Offset to beginning of page header */

  65114.   u8 *data;          /* Equal to pPage->aData */

  65115.   int usableSize;    /* Amount of usable space on each page */

  65116.   int nFree;         /* Number of unused bytes on the page */

  65117.   int top;           /* First byte of the cell content area */

  65118.   int iCellFirst;    /* First allowable cell or freeblock offset */

  65119.   int iCellLast;     /* Last possible cell or freeblock offset */

  65120. 

  65121.   assert( pPage->pBt!=0 );

  65122.   assert( pPage->pBt->db!=0 );

  65123.   assert( sqlite3_mutex_held(pPage->pBt->mutex) );

  65124.   assert( pPage->pgno==sqlite3PagerPagenumber(pPage->pDbPage) );

  65125.   assert( pPage == sqlite3PagerGetExtra(pPage->pDbPage) );

  65126.   assert( pPage->aData == sqlite3PagerGetData(pPage->pDbPage) );

  65127.   assert( pPage->isInit==1 );

  65128.   assert( pPage->nFree<0 );

  65129. 

  65130.   usableSize = pPage->pBt->usableSize;

  65131.   hdr = pPage->hdrOffset;

  65132.   data = pPage->aData;

  65133.   /* EVIDENCE-OF: R-58015-48175 The two-byte integer at offset 5 designates

  65134.   ** the start of the cell content area. A zero value for this integer is

  65135.   ** interpreted as 65536. */

  65136.   top = get2byteNotZero(&data[hdr+5]);

  65137.   iCellFirst = hdr + 8 + pPage->childPtrSize + 2*pPage->nCell;

  65138.   iCellLast = usableSize - 4;

  65139. 

  65140.   /* Compute the total free space on the page

  65141.   ** EVIDENCE-OF: R-23588-34450 The two-byte integer at offset 1 gives the

  65142.   ** start of the first freeblock on the page, or is zero if there are no

  65143.   ** freeblocks. */

  65144.   pc = get2byte(&data[hdr+1]);

  65145.   nFree = data[hdr+7] + top;  /* Init nFree to non-freeblock free space */

  65146.   if( pc>0 ){

  65147.     u32 next, size;

  65148.     if( pc<iCellFirst ){

  65149.       /* EVIDENCE-OF: R-55530-52930 In a well-formed b-tree page, there will

  65150.       ** always be at least one cell before the first freeblock.

  65151.       */

  65152.       return SQLITE_CORRUPT_PAGE(pPage); 

  65153.     }

  65154.     while( 1 ){

  65155.       if( pc>iCellLast ){

  65156.         /* Freeblock off the end of the page */

  65157.         return SQLITE_CORRUPT_PAGE(pPage);

  65158.       }

  65159.       next = get2byte(&data[pc]);

  65160.       size = get2byte(&data[pc+2]);

  65161.       nFree = nFree + size;

  65162.       if( next<=pc+size+3 ) break;

  65163.       pc = next;

  65164.     }

  65165.     if( next>0 ){

  65166.       /* Freeblock not in ascending order */

  65167.       return SQLITE_CORRUPT_PAGE(pPage);

  65168.     }

  65169.     if( pc+size>(unsigned int)usableSize ){

  65170.       /* Last freeblock extends past page end */

  65171.       return SQLITE_CORRUPT_PAGE(pPage);

  65172.     }

  65173.   }

  65174. 

  65175.   /* At this point, nFree contains the sum of the offset to the start

  65176.   ** of the cell-content area plus the number of free bytes within

  65177.   ** the cell-content area. If this is greater than the usable-size

  65178.   ** of the page, then the page must be corrupted. This check also

  65179.   ** serves to verify that the offset to the start of the cell-content

  65180.   ** area, according to the page header, lies within the page.

  65181.   */

  65182.   if( nFree>usableSize || nFree<iCellFirst ){

  65183.     return SQLITE_CORRUPT_PAGE(pPage);

  65184.   }

  65185.   pPage->nFree = (u16)(nFree - iCellFirst);

  65186.   return SQLITE_OK;

  65187. }

  65188. 

  65189. /*

  65190. ** Do additional sanity check after btreeInitPage() if

  65191. ** PRAGMA cell_size_check=ON 

  65192. */

  65193. static SQLITE_NOINLINE int btreeCellSizeCheck(MemPage *pPage){

  65194.   int iCellFirst;    /* First allowable cell or freeblock offset */

  65195.   int iCellLast;     /* Last possible cell or freeblock offset */

  65196.   int i;             /* Index into the cell pointer array */

  65197.   int sz;            /* Size of a cell */

  65198.   int pc;            /* Address of a freeblock within pPage->aData[] */

  65199.   u8 *data;          /* Equal to pPage->aData */

  65200.   int usableSize;    /* Maximum usable space on the page */

  65201.   int cellOffset;    /* Start of cell content area */

  65202. 

  65203.   iCellFirst = pPage->cellOffset + 2*pPage->nCell;

  65204.   usableSize = pPage->pBt->usableSize;

  65205.   iCellLast = usableSize - 4;

  65206.   data = pPage->aData;

  65207.   cellOffset = pPage->cellOffset;

  65208.   if( !pPage->leaf ) iCellLast--;

  65209.   for(i=0; i<pPage->nCell; i++){

  65210.     pc = get2byteAligned(&data[cellOffset+i*2]);

  65211.     testcase( pc==iCellFirst );

  65212.     testcase( pc==iCellLast );

  65213.     if( pc<iCellFirst || pc>iCellLast ){

  65214.       return SQLITE_CORRUPT_PAGE(pPage);

  65215.     }

  65216.     sz = pPage->xCellSize(pPage, &data[pc]);

  65217.     testcase( pc+sz==usableSize );

  65218.     if( pc+sz>usableSize ){

  65219.       return SQLITE_CORRUPT_PAGE(pPage);

  65220.     }

  65221.   }

  65222.   return SQLITE_OK;

  65223. }

  65224. 

  65225. /*

  65226. ** Initialize the auxiliary information for a disk block.

  65227. **

  65228. ** Return SQLITE_OK on success.  If we see that the page does

  65229. ** not contain a well-formed database page, then return 

  65230. ** SQLITE_CORRUPT.  Note that a return of SQLITE_OK does not

  65231. ** guarantee that the page is well-formed.  It only shows that

  65232. ** we failed to detect any corruption.

  65233. */

  65234. static int btreeInitPage(MemPage *pPage){

  65235.   u8 *data;          /* Equal to pPage->aData */

  65236.   BtShared *pBt;        /* The main btree structure */

  65237. 

  65238.   assert( pPage->pBt!=0 );

  65239.   assert( pPage->pBt->db!=0 );

  65240.   assert( sqlite3_mutex_held(pPage->pBt->mutex) );

  65241.   assert( pPage->pgno==sqlite3PagerPagenumber(pPage->pDbPage) );

  65242.   assert( pPage == sqlite3PagerGetExtra(pPage->pDbPage) );

  65243.   assert( pPage->aData == sqlite3PagerGetData(pPage->pDbPage) );

  65244.   assert( pPage->isInit==0 );

  65245. 

  65246.   pBt = pPage->pBt;

  65247.   data = pPage->aData + pPage->hdrOffset;

  65248.   /* EVIDENCE-OF: R-28594-02890 The one-byte flag at offset 0 indicating

  65249.   ** the b-tree page type. */

  65250.   if( decodeFlags(pPage, data[0]) ){

  65251.     return SQLITE_CORRUPT_PAGE(pPage);

  65252.   }

  65253.   assert( pBt->pageSize>=512 && pBt->pageSize<=65536 );

  65254.   pPage->maskPage = (u16)(pBt->pageSize - 1);

  65255.   pPage->nOverflow = 0;

  65256.   pPage->cellOffset = pPage->hdrOffset + 8 + pPage->childPtrSize;

  65257.   pPage->aCellIdx = data + pPage->childPtrSize + 8;

  65258.   pPage->aDataEnd = pPage->aData + pBt->usableSize;

  65259.   pPage->aDataOfst = pPage->aData + pPage->childPtrSize;

  65260.   /* EVIDENCE-OF: R-37002-32774 The two-byte integer at offset 3 gives the

  65261.   ** number of cells on the page. */

  65262.   pPage->nCell = get2byte(&data[3]);

  65263.   if( pPage->nCell>MX_CELL(pBt) ){

  65264.     /* To many cells for a single page.  The page must be corrupt */

  65265.     return SQLITE_CORRUPT_PAGE(pPage);

  65266.   }

  65267.   testcase( pPage->nCell==MX_CELL(pBt) );

  65268.   /* EVIDENCE-OF: R-24089-57979 If a page contains no cells (which is only

  65269.   ** possible for a root page of a table that contains no rows) then the

  65270.   ** offset to the cell content area will equal the page size minus the

  65271.   ** bytes of reserved space. */

  65272.   assert( pPage->nCell>0

  65273.        || get2byteNotZero(&data[5])==(int)pBt->usableSize

  65274.        || CORRUPT_DB );

  65275.   pPage->nFree = -1;  /* Indicate that this value is yet uncomputed */

  65276.   pPage->isInit = 1;

  65277.   if( pBt->db->flags & SQLITE_CellSizeCk ){

  65278.     return btreeCellSizeCheck(pPage);

  65279.   }

  65280.   return SQLITE_OK;

  65281. }

  65282. 

  65283. /*

  65284. ** Set up a raw page so that it looks like a database page holding

  65285. ** no entries.

  65286. */

  65287. static void zeroPage(MemPage *pPage, int flags){

  65288.   unsigned char *data = pPage->aData;

  65289.   BtShared *pBt = pPage->pBt;

  65290.   u8 hdr = pPage->hdrOffset;

  65291.   u16 first;

  65292. 

  65293.   assert( sqlite3PagerPagenumber(pPage->pDbPage)==pPage->pgno );

  65294.   assert( sqlite3PagerGetExtra(pPage->pDbPage) == (void*)pPage );

  65295.   assert( sqlite3PagerGetData(pPage->pDbPage) == data );

  65296.   assert( sqlite3PagerIswriteable(pPage->pDbPage) );

  65297.   assert( sqlite3_mutex_held(pBt->mutex) );

  65298.   if( pBt->btsFlags & BTS_FAST_SECURE ){

  65299.     memset(&data[hdr], 0, pBt->usableSize - hdr);

  65300.   }

  65301.   data[hdr] = (char)flags;

  65302.   first = hdr + ((flags&PTF_LEAF)==0 ? 12 : 8);

  65303.   memset(&data[hdr+1], 0, 4);

  65304.   data[hdr+7] = 0;

  65305.   put2byte(&data[hdr+5], pBt->usableSize);

  65306.   pPage->nFree = (u16)(pBt->usableSize - first);

  65307.   decodeFlags(pPage, flags);

  65308.   pPage->cellOffset = first;

  65309.   pPage->aDataEnd = &data[pBt->usableSize];

  65310.   pPage->aCellIdx = &data[first];

  65311.   pPage->aDataOfst = &data[pPage->childPtrSize];

  65312.   pPage->nOverflow = 0;

  65313.   assert( pBt->pageSize>=512 && pBt->pageSize<=65536 );

  65314.   pPage->maskPage = (u16)(pBt->pageSize - 1);

  65315.   pPage->nCell = 0;

  65316.   pPage->isInit = 1;

  65317. }

  65318. 

  65319. 

  65320. /*

  65321. ** Convert a DbPage obtained from the pager into a MemPage used by

  65322. ** the btree layer.

  65323. */

  65324. static MemPage *btreePageFromDbPage(DbPage *pDbPage, Pgno pgno, BtShared *pBt){

  65325.   MemPage *pPage = (MemPage*)sqlite3PagerGetExtra(pDbPage);

  65326.   if( pgno!=pPage->pgno ){

  65327.     pPage->aData = sqlite3PagerGetData(pDbPage);

  65328.     pPage->pDbPage = pDbPage;

  65329.     pPage->pBt = pBt;

  65330.     pPage->pgno = pgno;

  65331.     pPage->hdrOffset = pgno==1 ? 100 : 0;

  65332.   }

  65333.   assert( pPage->aData==sqlite3PagerGetData(pDbPage) );

  65334.   return pPage; 

  65335. }

  65336. 

  65337. /*

  65338. ** Get a page from the pager.  Initialize the MemPage.pBt and

  65339. ** MemPage.aData elements if needed.  See also: btreeGetUnusedPage().

  65340. **

  65341. ** If the PAGER_GET_NOCONTENT flag is set, it means that we do not care

  65342. ** about the content of the page at this time.  So do not go to the disk

  65343. ** to fetch the content.  Just fill in the content with zeros for now.

  65344. ** If in the future we call sqlite3PagerWrite() on this page, that

  65345. ** means we have started to be concerned about content and the disk

  65346. ** read should occur at that point.

  65347. */

  65348. static int btreeGetPage(

  65349.   BtShared *pBt,       /* The btree */

  65350.   Pgno pgno,           /* Number of the page to fetch */

  65351.   MemPage **ppPage,    /* Return the page in this parameter */

  65352.   int flags            /* PAGER_GET_NOCONTENT or PAGER_GET_READONLY */

  65353. ){

  65354.   int rc;

  65355.   DbPage *pDbPage;

  65356. 

  65357.   assert( flags==0 || flags==PAGER_GET_NOCONTENT || flags==PAGER_GET_READONLY );

  65358.   assert( sqlite3_mutex_held(pBt->mutex) );

  65359.   rc = sqlite3PagerGet(pBt->pPager, pgno, (DbPage**)&pDbPage, flags);

  65360.   if( rc ) return rc;

  65361.   *ppPage = btreePageFromDbPage(pDbPage, pgno, pBt);

  65362.   return SQLITE_OK;

  65363. }

  65364. 

  65365. /*

  65366. ** Retrieve a page from the pager cache. If the requested page is not

  65367. ** already in the pager cache return NULL. Initialize the MemPage.pBt and

  65368. ** MemPage.aData elements if needed.

  65369. */

  65370. static MemPage *btreePageLookup(BtShared *pBt, Pgno pgno){

  65371.   DbPage *pDbPage;

  65372.   assert( sqlite3_mutex_held(pBt->mutex) );

  65373.   pDbPage = sqlite3PagerLookup(pBt->pPager, pgno);

  65374.   if( pDbPage ){

  65375.     return btreePageFromDbPage(pDbPage, pgno, pBt);

  65376.   }

  65377.   return 0;

  65378. }

  65379. 

  65380. /*

  65381. ** Return the size of the database file in pages. If there is any kind of

  65382. ** error, return ((unsigned int)-1).

  65383. */

  65384. static Pgno btreePagecount(BtShared *pBt){

  65385.   return pBt->nPage;

  65386. }

  65387. SQLITE_PRIVATE u32 sqlite3BtreeLastPage(Btree *p){

  65388.   assert( sqlite3BtreeHoldsMutex(p) );

  65389.   assert( ((p->pBt->nPage)&0x80000000)==0 );

  65390.   return btreePagecount(p->pBt);

  65391. }

  65392. 

  65393. /*

  65394. ** Get a page from the pager and initialize it.

  65395. **

  65396. ** If pCur!=0 then the page is being fetched as part of a moveToChild()

  65397. ** call.  Do additional sanity checking on the page in this case.

  65398. ** And if the fetch fails, this routine must decrement pCur->iPage.

  65399. **

  65400. ** The page is fetched as read-write unless pCur is not NULL and is

  65401. ** a read-only cursor.

  65402. **

  65403. ** If an error occurs, then *ppPage is undefined. It

  65404. ** may remain unchanged, or it may be set to an invalid value.

  65405. */

  65406. static int getAndInitPage(

  65407.   BtShared *pBt,                  /* The database file */

  65408.   Pgno pgno,                      /* Number of the page to get */

  65409.   MemPage **ppPage,               /* Write the page pointer here */

  65410.   BtCursor *pCur,                 /* Cursor to receive the page, or NULL */

  65411.   int bReadOnly                   /* True for a read-only page */

  65412. ){

  65413.   int rc;

  65414.   DbPage *pDbPage;

  65415.   assert( sqlite3_mutex_held(pBt->mutex) );

  65416.   assert( pCur==0 || ppPage==&pCur->pPage );

  65417.   assert( pCur==0 || bReadOnly==pCur->curPagerFlags );

  65418.   assert( pCur==0 || pCur->iPage>0 );

  65419. 

  65420.   if( pgno>btreePagecount(pBt) ){

  65421.     rc = SQLITE_CORRUPT_BKPT;

  65422.     goto getAndInitPage_error1;

  65423.   }

  65424.   rc = sqlite3PagerGet(pBt->pPager, pgno, (DbPage**)&pDbPage, bReadOnly);

  65425.   if( rc ){

  65426.     goto getAndInitPage_error1;

  65427.   }

  65428.   *ppPage = (MemPage*)sqlite3PagerGetExtra(pDbPage);

  65429.   if( (*ppPage)->isInit==0 ){

  65430.     btreePageFromDbPage(pDbPage, pgno, pBt);

  65431.     rc = btreeInitPage(*ppPage);

  65432.     if( rc!=SQLITE_OK ){

  65433.       goto getAndInitPage_error2;

  65434.     }

  65435.   }

  65436.   assert( (*ppPage)->pgno==pgno );

  65437.   assert( (*ppPage)->aData==sqlite3PagerGetData(pDbPage) );

  65438. 

  65439.   /* If obtaining a child page for a cursor, we must verify that the page is

  65440.   ** compatible with the root page. */

  65441.   if( pCur && ((*ppPage)->nCell<1 || (*ppPage)->intKey!=pCur->curIntKey) ){

  65442.     rc = SQLITE_CORRUPT_PGNO(pgno);

  65443.     goto getAndInitPage_error2;

  65444.   }

  65445.   return SQLITE_OK;

  65446. 

  65447. getAndInitPage_error2:

  65448.   releasePage(*ppPage);

  65449. getAndInitPage_error1:

  65450.   if( pCur ){

  65451.     pCur->iPage--;

  65452.     pCur->pPage = pCur->apPage[pCur->iPage];

  65453.   }

  65454.   testcase( pgno==0 );

  65455.   assert( pgno!=0 || rc==SQLITE_CORRUPT );

  65456.   return rc;

  65457. }

  65458. 

  65459. /*

  65460. ** Release a MemPage.  This should be called once for each prior

  65461. ** call to btreeGetPage.

  65462. **

  65463. ** Page1 is a special case and must be released using releasePageOne().

  65464. */

  65465. static void releasePageNotNull(MemPage *pPage){

  65466.   assert( pPage->aData );

  65467.   assert( pPage->pBt );

  65468.   assert( pPage->pDbPage!=0 );

  65469.   assert( sqlite3PagerGetExtra(pPage->pDbPage) == (void*)pPage );

  65470.   assert( sqlite3PagerGetData(pPage->pDbPage)==pPage->aData );

  65471.   assert( sqlite3_mutex_held(pPage->pBt->mutex) );

  65472.   sqlite3PagerUnrefNotNull(pPage->pDbPage);

  65473. }

  65474. static void releasePage(MemPage *pPage){

  65475.   if( pPage ) releasePageNotNull(pPage);

  65476. }

  65477. static void releasePageOne(MemPage *pPage){

  65478.   assert( pPage!=0 );

  65479.   assert( pPage->aData );

  65480.   assert( pPage->pBt );

  65481.   assert( pPage->pDbPage!=0 );

  65482.   assert( sqlite3PagerGetExtra(pPage->pDbPage) == (void*)pPage );

  65483.   assert( sqlite3PagerGetData(pPage->pDbPage)==pPage->aData );

  65484.   assert( sqlite3_mutex_held(pPage->pBt->mutex) );

  65485.   sqlite3PagerUnrefPageOne(pPage->pDbPage);

  65486. }

  65487. 

  65488. /*

  65489. ** Get an unused page.

  65490. **

  65491. ** This works just like btreeGetPage() with the addition:

  65492. **

  65493. **   *  If the page is already in use for some other purpose, immediately

  65494. **      release it and return an SQLITE_CURRUPT error.

  65495. **   *  Make sure the isInit flag is clear

  65496. */

  65497. static int btreeGetUnusedPage(

  65498.   BtShared *pBt,       /* The btree */

  65499.   Pgno pgno,           /* Number of the page to fetch */

  65500.   MemPage **ppPage,    /* Return the page in this parameter */

  65501.   int flags            /* PAGER_GET_NOCONTENT or PAGER_GET_READONLY */

  65502. ){

  65503.   int rc = btreeGetPage(pBt, pgno, ppPage, flags);

  65504.   if( rc==SQLITE_OK ){

  65505.     if( sqlite3PagerPageRefcount((*ppPage)->pDbPage)>1 ){

  65506.       releasePage(*ppPage);

  65507.       *ppPage = 0;

  65508.       return SQLITE_CORRUPT_BKPT;

  65509.     }

  65510.     (*ppPage)->isInit = 0;

  65511.   }else{

  65512.     *ppPage = 0;

  65513.   }

  65514.   return rc;

  65515. }

  65516. 

  65517. 

  65518. /*

  65519. ** During a rollback, when the pager reloads information into the cache

  65520. ** so that the cache is restored to its original state at the start of

  65521. ** the transaction, for each page restored this routine is called.

  65522. **

  65523. ** This routine needs to reset the extra data section at the end of the

  65524. ** page to agree with the restored data.

  65525. */

  65526. static void pageReinit(DbPage *pData){

  65527.   MemPage *pPage;

  65528.   pPage = (MemPage *)sqlite3PagerGetExtra(pData);

  65529.   assert( sqlite3PagerPageRefcount(pData)>0 );

  65530.   if( pPage->isInit ){

  65531.     assert( sqlite3_mutex_held(pPage->pBt->mutex) );

  65532.     pPage->isInit = 0;

  65533.     if( sqlite3PagerPageRefcount(pData)>1 ){

  65534.       /* pPage might not be a btree page;  it might be an overflow page

  65535.       ** or ptrmap page or a free page.  In those cases, the following

  65536.       ** call to btreeInitPage() will likely return SQLITE_CORRUPT.

  65537.       ** But no harm is done by this.  And it is very important that

  65538.       ** btreeInitPage() be called on every btree page so we make

  65539.       ** the call for every page that comes in for re-initing. */

  65540.       btreeInitPage(pPage);

  65541.     }

  65542.   }

  65543. }

  65544. 

  65545. /*

  65546. ** Invoke the busy handler for a btree.

  65547. */

  65548. static int btreeInvokeBusyHandler(void *pArg){

  65549.   BtShared *pBt = (BtShared*)pArg;

  65550.   assert( pBt->db );

  65551.   assert( sqlite3_mutex_held(pBt->db->mutex) );

  65552.   return sqlite3InvokeBusyHandler(&pBt->db->busyHandler,

  65553.                                   sqlite3PagerFile(pBt->pPager));

  65554. }

  65555. 

  65556. /*

  65557. ** Open a database file.

  65558. ** 

  65559. ** zFilename is the name of the database file.  If zFilename is NULL

  65560. ** then an ephemeral database is created.  The ephemeral database might

  65561. ** be exclusively in memory, or it might use a disk-based memory cache.

  65562. ** Either way, the ephemeral database will be automatically deleted 

  65563. ** when sqlite3BtreeClose() is called.

  65564. **

  65565. ** If zFilename is ":memory:" then an in-memory database is created

  65566. ** that is automatically destroyed when it is closed.

  65567. **

  65568. ** The "flags" parameter is a bitmask that might contain bits like

  65569. ** BTREE_OMIT_JOURNAL and/or BTREE_MEMORY.

  65570. **

  65571. ** If the database is already opened in the same database connection

  65572. ** and we are in shared cache mode, then the open will fail with an

  65573. ** SQLITE_CONSTRAINT error.  We cannot allow two or more BtShared

  65574. ** objects in the same database connection since doing so will lead

  65575. ** to problems with locking.

  65576. */

  65577. SQLITE_PRIVATE int sqlite3BtreeOpen(

  65578.   sqlite3_vfs *pVfs,      /* VFS to use for this b-tree */

  65579.   const char *zFilename,  /* Name of the file containing the BTree database */

  65580.   sqlite3 *db,            /* Associated database handle */

  65581.   Btree **ppBtree,        /* Pointer to new Btree object written here */

  65582.   int flags,              /* Options */

  65583.   int vfsFlags            /* Flags passed through to sqlite3_vfs.xOpen() */

  65584. ){

  65585.   BtShared *pBt = 0;             /* Shared part of btree structure */

  65586.   Btree *p;                      /* Handle to return */

  65587.   sqlite3_mutex *mutexOpen = 0;  /* Prevents a race condition. Ticket #3537 */

  65588.   int rc = SQLITE_OK;            /* Result code from this function */

  65589.   u8 nReserve;                   /* Byte of unused space on each page */

  65590.   unsigned char zDbHeader[100];  /* Database header content */

  65591. 

  65592.   /* True if opening an ephemeral, temporary database */

  65593.   const int isTempDb = zFilename==0 || zFilename[0]==0;

  65594. 

  65595.   /* Set the variable isMemdb to true for an in-memory database, or 

  65596.   ** false for a file-based database.

  65597.   */

  65598. #ifdef SQLITE_OMIT_MEMORYDB

  65599.   const int isMemdb = 0;

  65600. #else

  65601.   const int isMemdb = (zFilename && strcmp(zFilename, ":memory:")==0)

  65602.                        || (isTempDb && sqlite3TempInMemory(db))

  65603.                        || (vfsFlags & SQLITE_OPEN_MEMORY)!=0;

  65604. #endif

  65605. 

  65606.   assert( db!=0 );

  65607.   assert( pVfs!=0 );

  65608.   assert( sqlite3_mutex_held(db->mutex) );

  65609.   assert( (flags&0xff)==flags );   /* flags fit in 8 bits */

  65610. 

  65611.   /* Only a BTREE_SINGLE database can be BTREE_UNORDERED */

  65612.   assert( (flags & BTREE_UNORDERED)==0 || (flags & BTREE_SINGLE)!=0 );

  65613. 

  65614.   /* A BTREE_SINGLE database is always a temporary and/or ephemeral */

  65615.   assert( (flags & BTREE_SINGLE)==0 || isTempDb );

  65616. 

  65617.   if( isMemdb ){

  65618.     flags |= BTREE_MEMORY;

  65619.   }

  65620.   if( (vfsFlags & SQLITE_OPEN_MAIN_DB)!=0 && (isMemdb || isTempDb) ){

  65621.     vfsFlags = (vfsFlags & ~SQLITE_OPEN_MAIN_DB) | SQLITE_OPEN_TEMP_DB;

  65622.   }

  65623.   p = sqlite3MallocZero(sizeof(Btree));

  65624.   if( !p ){

  65625.     return SQLITE_NOMEM_BKPT;

  65626.   }

  65627.   p->inTrans = TRANS_NONE;

  65628.   p->db = db;

  65629. #ifndef SQLITE_OMIT_SHARED_CACHE

  65630.   p->lock.pBtree = p;

  65631.   p->lock.iTable = 1;

  65632. #endif

  65633. 

  65634. #if !defined(SQLITE_OMIT_SHARED_CACHE) && !defined(SQLITE_OMIT_DISKIO)

  65635.   /*

  65636.   ** If this Btree is a candidate for shared cache, try to find an

  65637.   ** existing BtShared object that we can share with

  65638.   */

  65639.   if( isTempDb==0 && (isMemdb==0 || (vfsFlags&SQLITE_OPEN_URI)!=0) ){

  65640.     if( vfsFlags & SQLITE_OPEN_SHAREDCACHE ){

  65641.       int nFilename = sqlite3Strlen30(zFilename)+1;

  65642.       int nFullPathname = pVfs->mxPathname+1;

  65643.       char *zFullPathname = sqlite3Malloc(MAX(nFullPathname,nFilename));

  65644.       MUTEX_LOGIC( sqlite3_mutex *mutexShared; )

  65645. 

  65646.       p->sharable = 1;

  65647.       if( !zFullPathname ){

  65648.         sqlite3_free(p);

  65649.         return SQLITE_NOMEM_BKPT;

  65650.       }

  65651.       if( isMemdb ){

  65652.         memcpy(zFullPathname, zFilename, nFilename);

  65653.       }else{

  65654.         rc = sqlite3OsFullPathname(pVfs, zFilename,

  65655.                                    nFullPathname, zFullPathname);

  65656.         if( rc ){

  65657.           sqlite3_free(zFullPathname);

  65658.           sqlite3_free(p);

  65659.           return rc;

  65660.         }

  65661.       }

  65662. #if SQLITE_THREADSAFE

  65663.       mutexOpen = sqlite3MutexAlloc(SQLITE_MUTEX_STATIC_OPEN);

  65664.       sqlite3_mutex_enter(mutexOpen);

  65665.       mutexShared = sqlite3MutexAlloc(SQLITE_MUTEX_STATIC_MASTER);

  65666.       sqlite3_mutex_enter(mutexShared);

  65667. #endif

  65668.       for(pBt=GLOBAL(BtShared*,sqlite3SharedCacheList); pBt; pBt=pBt->pNext){

  65669.         assert( pBt->nRef>0 );

  65670.         if( 0==strcmp(zFullPathname, sqlite3PagerFilename(pBt->pPager, 0))

  65671.                  && sqlite3PagerVfs(pBt->pPager)==pVfs ){

  65672.           int iDb;

  65673.           for(iDb=db->nDb-1; iDb>=0; iDb--){

  65674.             Btree *pExisting = db->aDb[iDb].pBt;

  65675.             if( pExisting && pExisting->pBt==pBt ){

  65676.               sqlite3_mutex_leave(mutexShared);

  65677.               sqlite3_mutex_leave(mutexOpen);

  65678.               sqlite3_free(zFullPathname);

  65679.               sqlite3_free(p);

  65680.               return SQLITE_CONSTRAINT;

  65681.             }

  65682.           }

  65683.           p->pBt = pBt;

  65684.           pBt->nRef++;

  65685.           break;

  65686.         }

  65687.       }

  65688.       sqlite3_mutex_leave(mutexShared);

  65689.       sqlite3_free(zFullPathname);

  65690.     }

  65691. #ifdef SQLITE_DEBUG

  65692.     else{

  65693.       /* In debug mode, we mark all persistent databases as sharable

  65694.       ** even when they are not.  This exercises the locking code and

  65695.       ** gives more opportunity for asserts(sqlite3_mutex_held())

  65696.       ** statements to find locking problems.

  65697.       */

  65698.       p->sharable = 1;

  65699.     }

  65700. #endif

  65701.   }

  65702. #endif

  65703.   if( pBt==0 ){

  65704.     /*

  65705.     ** The following asserts make sure that structures used by the btree are

  65706.     ** the right size.  This is to guard against size changes that result

  65707.     ** when compiling on a different architecture.

  65708.     */

  65709.     assert( sizeof(i64)==8 );

  65710.     assert( sizeof(u64)==8 );

  65711.     assert( sizeof(u32)==4 );

  65712.     assert( sizeof(u16)==2 );

  65713.     assert( sizeof(Pgno)==4 );

  65714.   

  65715.     pBt = sqlite3MallocZero( sizeof(*pBt) );

  65716.     if( pBt==0 ){

  65717.       rc = SQLITE_NOMEM_BKPT;

  65718.       goto btree_open_out;

  65719.     }

  65720.     rc = sqlite3PagerOpen(pVfs, &pBt->pPager, zFilename,

  65721.                           sizeof(MemPage), flags, vfsFlags, pageReinit);

  65722.     if( rc==SQLITE_OK ){

  65723.       sqlite3PagerSetMmapLimit(pBt->pPager, db->szMmap);

  65724.       rc = sqlite3PagerReadFileheader(pBt->pPager,sizeof(zDbHeader),zDbHeader);

  65725.     }

  65726.     if( rc!=SQLITE_OK ){

  65727.       goto btree_open_out;

  65728.     }

  65729.     pBt->openFlags = (u8)flags;

  65730.     pBt->db = db;

  65731.     sqlite3PagerSetBusyHandler(pBt->pPager, btreeInvokeBusyHandler, pBt);

  65732.     p->pBt = pBt;

  65733.   

  65734.     pBt->pCursor = 0;

  65735.     pBt->pPage1 = 0;

  65736.     if( sqlite3PagerIsreadonly(pBt->pPager) ) pBt->btsFlags |= BTS_READ_ONLY;

  65737. #if defined(SQLITE_SECURE_DELETE)

  65738.     pBt->btsFlags |= BTS_SECURE_DELETE;

  65739. #elif defined(SQLITE_FAST_SECURE_DELETE)

  65740.     pBt->btsFlags |= BTS_OVERWRITE;

  65741. #endif

  65742.     /* EVIDENCE-OF: R-51873-39618 The page size for a database file is

  65743.     ** determined by the 2-byte integer located at an offset of 16 bytes from

  65744.     ** the beginning of the database file. */

  65745.     pBt->pageSize = (zDbHeader[16]<<8) | (zDbHeader[17]<<16);

  65746.     if( pBt->pageSize<512 || pBt->pageSize>SQLITE_MAX_PAGE_SIZE

  65747.          || ((pBt->pageSize-1)&pBt->pageSize)!=0 ){

  65748.       pBt->pageSize = 0;

  65749. #ifndef SQLITE_OMIT_AUTOVACUUM

  65750.       /* If the magic name ":memory:" will create an in-memory database, then

  65751.       ** leave the autoVacuum mode at 0 (do not auto-vacuum), even if

  65752.       ** SQLITE_DEFAULT_AUTOVACUUM is true. On the other hand, if

  65753.       ** SQLITE_OMIT_MEMORYDB has been defined, then ":memory:" is just a

  65754.       ** regular file-name. In this case the auto-vacuum applies as per normal.

  65755.       */

  65756.       if( zFilename && !isMemdb ){

  65757.         pBt->autoVacuum = (SQLITE_DEFAULT_AUTOVACUUM ? 1 : 0);

  65758.         pBt->incrVacuum = (SQLITE_DEFAULT_AUTOVACUUM==2 ? 1 : 0);

  65759.       }

  65760. #endif

  65761.       nReserve = 0;

  65762.     }else{

  65763.       /* EVIDENCE-OF: R-37497-42412 The size of the reserved region is

  65764.       ** determined by the one-byte unsigned integer found at an offset of 20

  65765.       ** into the database file header. */

  65766.       nReserve = zDbHeader[20];

  65767.       pBt->btsFlags |= BTS_PAGESIZE_FIXED;

  65768. #ifndef SQLITE_OMIT_AUTOVACUUM

  65769.       pBt->autoVacuum = (get4byte(&zDbHeader[36 + 4*4])?1:0);

  65770.       pBt->incrVacuum = (get4byte(&zDbHeader[36 + 7*4])?1:0);

  65771. #endif

  65772.     }

  65773.     rc = sqlite3PagerSetPagesize(pBt->pPager, &pBt->pageSize, nReserve);

  65774.     if( rc ) goto btree_open_out;

  65775.     pBt->usableSize = pBt->pageSize - nReserve;

  65776.     assert( (pBt->pageSize & 7)==0 );  /* 8-byte alignment of pageSize */

  65777.    

  65778. #if !defined(SQLITE_OMIT_SHARED_CACHE) && !defined(SQLITE_OMIT_DISKIO)

  65779.     /* Add the new BtShared object to the linked list sharable BtShareds.

  65780.     */

  65781.     pBt->nRef = 1;

  65782.     if( p->sharable ){

  65783.       MUTEX_LOGIC( sqlite3_mutex *mutexShared; )

  65784.       MUTEX_LOGIC( mutexShared = sqlite3MutexAlloc(SQLITE_MUTEX_STATIC_MASTER);)

  65785.       if( SQLITE_THREADSAFE && sqlite3GlobalConfig.bCoreMutex ){

  65786.         pBt->mutex = sqlite3MutexAlloc(SQLITE_MUTEX_FAST);

  65787.         if( pBt->mutex==0 ){

  65788.           rc = SQLITE_NOMEM_BKPT;

  65789.           goto btree_open_out;

  65790.         }

  65791.       }

  65792.       sqlite3_mutex_enter(mutexShared);

  65793.       pBt->pNext = GLOBAL(BtShared*,sqlite3SharedCacheList);

  65794.       GLOBAL(BtShared*,sqlite3SharedCacheList) = pBt;

  65795.       sqlite3_mutex_leave(mutexShared);

  65796.     }

  65797. #endif

  65798.   }

  65799. 

  65800. #if !defined(SQLITE_OMIT_SHARED_CACHE) && !defined(SQLITE_OMIT_DISKIO)

  65801.   /* If the new Btree uses a sharable pBtShared, then link the new

  65802.   ** Btree into the list of all sharable Btrees for the same connection.

  65803.   ** The list is kept in ascending order by pBt address.

  65804.   */

  65805.   if( p->sharable ){

  65806.     int i;

  65807.     Btree *pSib;

  65808.     for(i=0; i<db->nDb; i++){

  65809.       if( (pSib = db->aDb[i].pBt)!=0 && pSib->sharable ){

  65810.         while( pSib->pPrev ){ pSib = pSib->pPrev; }

  65811.         if( (uptr)p->pBt<(uptr)pSib->pBt ){

  65812.           p->pNext = pSib;

  65813.           p->pPrev = 0;

  65814.           pSib->pPrev = p;

  65815.         }else{

  65816.           while( pSib->pNext && (uptr)pSib->pNext->pBt<(uptr)p->pBt ){

  65817.             pSib = pSib->pNext;

  65818.           }

  65819.           p->pNext = pSib->pNext;

  65820.           p->pPrev = pSib;

  65821.           if( p->pNext ){

  65822.             p->pNext->pPrev = p;

  65823.           }

  65824.           pSib->pNext = p;

  65825.         }

  65826.         break;

  65827.       }

  65828.     }

  65829.   }

  65830. #endif

  65831.   *ppBtree = p;

  65832. 

  65833. btree_open_out:

  65834.   if( rc!=SQLITE_OK ){

  65835.     if( pBt && pBt->pPager ){

  65836.       sqlite3PagerClose(pBt->pPager, 0);

  65837.     }

  65838.     sqlite3_free(pBt);

  65839.     sqlite3_free(p);

  65840.     *ppBtree = 0;

  65841.   }else{

  65842.     sqlite3_file *pFile;

  65843. 

  65844.     /* If the B-Tree was successfully opened, set the pager-cache size to the

  65845.     ** default value. Except, when opening on an existing shared pager-cache,

  65846.     ** do not change the pager-cache size.

  65847.     */

  65848.     if( sqlite3BtreeSchema(p, 0, 0)==0 ){

  65849.       sqlite3PagerSetCachesize(p->pBt->pPager, SQLITE_DEFAULT_CACHE_SIZE);

  65850.     }

  65851. 

  65852.     pFile = sqlite3PagerFile(pBt->pPager);

  65853.     if( pFile->pMethods ){

  65854.       sqlite3OsFileControlHint(pFile, SQLITE_FCNTL_PDB, (void*)&pBt->db);

  65855.     }

  65856.   }

  65857.   if( mutexOpen ){

  65858.     assert( sqlite3_mutex_held(mutexOpen) );

  65859.     sqlite3_mutex_leave(mutexOpen);

  65860.   }

  65861.   assert( rc!=SQLITE_OK || sqlite3BtreeConnectionCount(*ppBtree)>0 );

  65862.   return rc;

  65863. }

  65864. 

  65865. /*

  65866. ** Decrement the BtShared.nRef counter.  When it reaches zero,

  65867. ** remove the BtShared structure from the sharing list.  Return

  65868. ** true if the BtShared.nRef counter reaches zero and return

  65869. ** false if it is still positive.

  65870. */

  65871. static int removeFromSharingList(BtShared *pBt){

  65872. #ifndef SQLITE_OMIT_SHARED_CACHE

  65873.   MUTEX_LOGIC( sqlite3_mutex *pMaster; )

  65874.   BtShared *pList;

  65875.   int removed = 0;

  65876. 

  65877.   assert( sqlite3_mutex_notheld(pBt->mutex) );

  65878.   MUTEX_LOGIC( pMaster = sqlite3MutexAlloc(SQLITE_MUTEX_STATIC_MASTER); )

  65879.   sqlite3_mutex_enter(pMaster);

  65880.   pBt->nRef--;

  65881.   if( pBt->nRef<=0 ){

  65882.     if( GLOBAL(BtShared*,sqlite3SharedCacheList)==pBt ){

  65883.       GLOBAL(BtShared*,sqlite3SharedCacheList) = pBt->pNext;

  65884.     }else{

  65885.       pList = GLOBAL(BtShared*,sqlite3SharedCacheList);

  65886.       while( ALWAYS(pList) && pList->pNext!=pBt ){

  65887.         pList=pList->pNext;

  65888.       }

  65889.       if( ALWAYS(pList) ){

  65890.         pList->pNext = pBt->pNext;

  65891.       }

  65892.     }

  65893.     if( SQLITE_THREADSAFE ){

  65894.       sqlite3_mutex_free(pBt->mutex);

  65895.     }

  65896.     removed = 1;

  65897.   }

  65898.   sqlite3_mutex_leave(pMaster);

  65899.   return removed;

  65900. #else

  65901.   return 1;

  65902. #endif

  65903. }

  65904. 

  65905. /*

  65906. ** Make sure pBt->pTmpSpace points to an allocation of 

  65907. ** MX_CELL_SIZE(pBt) bytes with a 4-byte prefix for a left-child

  65908. ** pointer.

  65909. */

  65910. static void allocateTempSpace(BtShared *pBt){

  65911.   if( !pBt->pTmpSpace ){

  65912.     pBt->pTmpSpace = sqlite3PageMalloc( pBt->pageSize );

  65913. 

  65914.     /* One of the uses of pBt->pTmpSpace is to format cells before

  65915.     ** inserting them into a leaf page (function fillInCell()). If

  65916.     ** a cell is less than 4 bytes in size, it is rounded up to 4 bytes

  65917.     ** by the various routines that manipulate binary cells. Which

  65918.     ** can mean that fillInCell() only initializes the first 2 or 3

  65919.     ** bytes of pTmpSpace, but that the first 4 bytes are copied from

  65920.     ** it into a database page. This is not actually a problem, but it

  65921.     ** does cause a valgrind error when the 1 or 2 bytes of unitialized 

  65922.     ** data is passed to system call write(). So to avoid this error,

  65923.     ** zero the first 4 bytes of temp space here.

  65924.     **

  65925.     ** Also:  Provide four bytes of initialized space before the

  65926.     ** beginning of pTmpSpace as an area available to prepend the

  65927.     ** left-child pointer to the beginning of a cell.

  65928.     */

  65929.     if( pBt->pTmpSpace ){

  65930.       memset(pBt->pTmpSpace, 0, 8);

  65931.       pBt->pTmpSpace += 4;

  65932.     }

  65933.   }

  65934. }

  65935. 

  65936. /*

  65937. ** Free the pBt->pTmpSpace allocation

  65938. */

  65939. static void freeTempSpace(BtShared *pBt){

  65940.   if( pBt->pTmpSpace ){

  65941.     pBt->pTmpSpace -= 4;

  65942.     sqlite3PageFree(pBt->pTmpSpace);

  65943.     pBt->pTmpSpace = 0;

  65944.   }

  65945. }

  65946. 

  65947. /*

  65948. ** Close an open database and invalidate all cursors.

  65949. */

  65950. SQLITE_PRIVATE int sqlite3BtreeClose(Btree *p){

  65951.   BtShared *pBt = p->pBt;

  65952.   BtCursor *pCur;

  65953. 

  65954.   /* Close all cursors opened via this handle.  */

  65955.   assert( sqlite3_mutex_held(p->db->mutex) );

  65956.   sqlite3BtreeEnter(p);

  65957.   pCur = pBt->pCursor;

  65958.   while( pCur ){

  65959.     BtCursor *pTmp = pCur;

  65960.     pCur = pCur->pNext;

  65961.     if( pTmp->pBtree==p ){

  65962.       sqlite3BtreeCloseCursor(pTmp);

  65963.     }

  65964.   }

  65965. 

  65966.   /* Rollback any active transaction and free the handle structure.

  65967.   ** The call to sqlite3BtreeRollback() drops any table-locks held by

  65968.   ** this handle.

  65969.   */

  65970.   sqlite3BtreeRollback(p, SQLITE_OK, 0);

  65971.   sqlite3BtreeLeave(p);

  65972. 

  65973.   /* If there are still other outstanding references to the shared-btree

  65974.   ** structure, return now. The remainder of this procedure cleans 

  65975.   ** up the shared-btree.

  65976.   */

  65977.   assert( p->wantToLock==0 && p->locked==0 );

  65978.   if( !p->sharable || removeFromSharingList(pBt) ){

  65979.     /* The pBt is no longer on the sharing list, so we can access

  65980.     ** it without having to hold the mutex.

  65981.     **

  65982.     ** Clean out and delete the BtShared object.

  65983.     */

  65984.     assert( !pBt->pCursor );

  65985.     sqlite3PagerClose(pBt->pPager, p->db);

  65986.     if( pBt->xFreeSchema && pBt->pSchema ){

  65987.       pBt->xFreeSchema(pBt->pSchema);

  65988.     }

  65989.     sqlite3DbFree(0, pBt->pSchema);

  65990.     freeTempSpace(pBt);

  65991.     sqlite3_free(pBt);

  65992.   }

  65993. 

  65994. #ifndef SQLITE_OMIT_SHARED_CACHE

  65995.   assert( p->wantToLock==0 );

  65996.   assert( p->locked==0 );

  65997.   if( p->pPrev ) p->pPrev->pNext = p->pNext;

  65998.   if( p->pNext ) p->pNext->pPrev = p->pPrev;

  65999. #endif

  66000. 

  66001.   sqlite3_free(p);

  66002.   return SQLITE_OK;

  66003. }

  66004. 

  66005. /*

  66006. ** Change the "soft" limit on the number of pages in the cache.

  66007. ** Unused and unmodified pages will be recycled when the number of

  66008. ** pages in the cache exceeds this soft limit.  But the size of the

  66009. ** cache is allowed to grow larger than this limit if it contains

  66010. ** dirty pages or pages still in active use.

  66011. */

  66012. SQLITE_PRIVATE int sqlite3BtreeSetCacheSize(Btree *p, int mxPage){

  66013.   BtShared *pBt = p->pBt;

  66014.   assert( sqlite3_mutex_held(p->db->mutex) );

  66015.   sqlite3BtreeEnter(p);

  66016.   sqlite3PagerSetCachesize(pBt->pPager, mxPage);

  66017.   sqlite3BtreeLeave(p);

  66018.   return SQLITE_OK;

  66019. }

  66020. 

  66021. /*

  66022. ** Change the "spill" limit on the number of pages in the cache.

  66023. ** If the number of pages exceeds this limit during a write transaction,

  66024. ** the pager might attempt to "spill" pages to the journal early in

  66025. ** order to free up memory.

  66026. **

  66027. ** The value returned is the current spill size.  If zero is passed

  66028. ** as an argument, no changes are made to the spill size setting, so

  66029. ** using mxPage of 0 is a way to query the current spill size.

  66030. */

  66031. SQLITE_PRIVATE int sqlite3BtreeSetSpillSize(Btree *p, int mxPage){

  66032.   BtShared *pBt = p->pBt;

  66033.   int res;

  66034.   assert( sqlite3_mutex_held(p->db->mutex) );

  66035.   sqlite3BtreeEnter(p);

  66036.   res = sqlite3PagerSetSpillsize(pBt->pPager, mxPage);

  66037.   sqlite3BtreeLeave(p);

  66038.   return res;

  66039. }

  66040. 

  66041. #if SQLITE_MAX_MMAP_SIZE>0

  66042. /*

  66043. ** Change the limit on the amount of the database file that may be

  66044. ** memory mapped.

  66045. */

  66046. SQLITE_PRIVATE int sqlite3BtreeSetMmapLimit(Btree *p, sqlite3_int64 szMmap){

  66047.   BtShared *pBt = p->pBt;

  66048.   assert( sqlite3_mutex_held(p->db->mutex) );

  66049.   sqlite3BtreeEnter(p);

  66050.   sqlite3PagerSetMmapLimit(pBt->pPager, szMmap);

  66051.   sqlite3BtreeLeave(p);

  66052.   return SQLITE_OK;

  66053. }

  66054. #endif /* SQLITE_MAX_MMAP_SIZE>0 */

  66055. 

  66056. /*

  66057. ** Change the way data is synced to disk in order to increase or decrease

  66058. ** how well the database resists damage due to OS crashes and power

  66059. ** failures.  Level 1 is the same as asynchronous (no syncs() occur and

  66060. ** there is a high probability of damage)  Level 2 is the default.  There

  66061. ** is a very low but non-zero probability of damage.  Level 3 reduces the

  66062. ** probability of damage to near zero but with a write performance reduction.

  66063. */

  66064. #ifndef SQLITE_OMIT_PAGER_PRAGMAS

  66065. SQLITE_PRIVATE int sqlite3BtreeSetPagerFlags(

  66066.   Btree *p,              /* The btree to set the safety level on */

  66067.   unsigned pgFlags       /* Various PAGER_* flags */

  66068. ){

  66069.   BtShared *pBt = p->pBt;

  66070.   assert( sqlite3_mutex_held(p->db->mutex) );

  66071.   sqlite3BtreeEnter(p);

  66072.   sqlite3PagerSetFlags(pBt->pPager, pgFlags);

  66073.   sqlite3BtreeLeave(p);

  66074.   return SQLITE_OK;

  66075. }

  66076. #endif

  66077. 

  66078. /*

  66079. ** Change the default pages size and the number of reserved bytes per page.

  66080. ** Or, if the page size has already been fixed, return SQLITE_READONLY 

  66081. ** without changing anything.

  66082. **

  66083. ** The page size must be a power of 2 between 512 and 65536.  If the page

  66084. ** size supplied does not meet this constraint then the page size is not

  66085. ** changed.

  66086. **

  66087. ** Page sizes are constrained to be a power of two so that the region

  66088. ** of the database file used for locking (beginning at PENDING_BYTE,

  66089. ** the first byte past the 1GB boundary, 0x40000000) needs to occur

  66090. ** at the beginning of a page.

  66091. **

  66092. ** If parameter nReserve is less than zero, then the number of reserved

  66093. ** bytes per page is left unchanged.

  66094. **

  66095. ** If the iFix!=0 then the BTS_PAGESIZE_FIXED flag is set so that the page size

  66096. ** and autovacuum mode can no longer be changed.

  66097. */

  66098. SQLITE_PRIVATE int sqlite3BtreeSetPageSize(Btree *p, int pageSize, int nReserve, int iFix){

  66099.   int rc = SQLITE_OK;

  66100.   BtShared *pBt = p->pBt;

  66101.   assert( nReserve>=-1 && nReserve<=255 );

  66102.   sqlite3BtreeEnter(p);

  66103. #if SQLITE_HAS_CODEC

  66104.   if( nReserve>pBt->optimalReserve ) pBt->optimalReserve = (u8)nReserve;

  66105. #endif

  66106.   if( pBt->btsFlags & BTS_PAGESIZE_FIXED ){

  66107.     sqlite3BtreeLeave(p);

  66108.     return SQLITE_READONLY;

  66109.   }

  66110.   if( nReserve<0 ){

  66111.     nReserve = pBt->pageSize - pBt->usableSize;

  66112.   }

  66113.   assert( nReserve>=0 && nReserve<=255 );

  66114.   if( pageSize>=512 && pageSize<=SQLITE_MAX_PAGE_SIZE &&

  66115.         ((pageSize-1)&pageSize)==0 ){

  66116.     assert( (pageSize & 7)==0 );

  66117.     assert( !pBt->pCursor );

  66118.     pBt->pageSize = (u32)pageSize;

  66119.     freeTempSpace(pBt);

  66120.   }

  66121.   rc = sqlite3PagerSetPagesize(pBt->pPager, &pBt->pageSize, nReserve);

  66122.   pBt->usableSize = pBt->pageSize - (u16)nReserve;

  66123.   if( iFix ) pBt->btsFlags |= BTS_PAGESIZE_FIXED;

  66124.   sqlite3BtreeLeave(p);

  66125.   return rc;

  66126. }

  66127. 

  66128. /*

  66129. ** Return the currently defined page size

  66130. */

  66131. SQLITE_PRIVATE int sqlite3BtreeGetPageSize(Btree *p){

  66132.   return p->pBt->pageSize;

  66133. }

  66134. 

  66135. /*

  66136. ** This function is similar to sqlite3BtreeGetReserve(), except that it

  66137. ** may only be called if it is guaranteed that the b-tree mutex is already

  66138. ** held.

  66139. **

  66140. ** This is useful in one special case in the backup API code where it is

  66141. ** known that the shared b-tree mutex is held, but the mutex on the 

  66142. ** database handle that owns *p is not. In this case if sqlite3BtreeEnter()

  66143. ** were to be called, it might collide with some other operation on the

  66144. ** database handle that owns *p, causing undefined behavior.

  66145. */

  66146. SQLITE_PRIVATE int sqlite3BtreeGetReserveNoMutex(Btree *p){

  66147.   int n;

  66148.   assert( sqlite3_mutex_held(p->pBt->mutex) );

  66149.   n = p->pBt->pageSize - p->pBt->usableSize;

  66150.   return n;

  66151. }

  66152. 

  66153. /*

  66154. ** Return the number of bytes of space at the end of every page that

  66155. ** are intentually left unused.  This is the "reserved" space that is

  66156. ** sometimes used by extensions.

  66157. **

  66158. ** If SQLITE_HAS_MUTEX is defined then the number returned is the

  66159. ** greater of the current reserved space and the maximum requested

  66160. ** reserve space.

  66161. */

  66162. SQLITE_PRIVATE int sqlite3BtreeGetOptimalReserve(Btree *p){

  66163.   int n;

  66164.   sqlite3BtreeEnter(p);

  66165.   n = sqlite3BtreeGetReserveNoMutex(p);

  66166. #ifdef SQLITE_HAS_CODEC

  66167.   if( n<p->pBt->optimalReserve ) n = p->pBt->optimalReserve;

  66168. #endif

  66169.   sqlite3BtreeLeave(p);

  66170.   return n;

  66171. }

  66172. 

  66173. 

  66174. /*

  66175. ** Set the maximum page count for a database if mxPage is positive.

  66176. ** No changes are made if mxPage is 0 or negative.

  66177. ** Regardless of the value of mxPage, return the maximum page count.

  66178. */

  66179. SQLITE_PRIVATE int sqlite3BtreeMaxPageCount(Btree *p, int mxPage){

  66180.   int n;

  66181.   sqlite3BtreeEnter(p);

  66182.   n = sqlite3PagerMaxPageCount(p->pBt->pPager, mxPage);

  66183.   sqlite3BtreeLeave(p);

  66184.   return n;

  66185. }

  66186. 

  66187. /*

  66188. ** Change the values for the BTS_SECURE_DELETE and BTS_OVERWRITE flags:

  66189. **

  66190. **    newFlag==0       Both BTS_SECURE_DELETE and BTS_OVERWRITE are cleared

  66191. **    newFlag==1       BTS_SECURE_DELETE set and BTS_OVERWRITE is cleared

  66192. **    newFlag==2       BTS_SECURE_DELETE cleared and BTS_OVERWRITE is set

  66193. **    newFlag==(-1)    No changes

  66194. **

  66195. ** This routine acts as a query if newFlag is less than zero

  66196. **

  66197. ** With BTS_OVERWRITE set, deleted content is overwritten by zeros, but

  66198. ** freelist leaf pages are not written back to the database.  Thus in-page

  66199. ** deleted content is cleared, but freelist deleted content is not.

  66200. **

  66201. ** With BTS_SECURE_DELETE, operation is like BTS_OVERWRITE with the addition

  66202. ** that freelist leaf pages are written back into the database, increasing

  66203. ** the amount of disk I/O.

  66204. */

  66205. SQLITE_PRIVATE int sqlite3BtreeSecureDelete(Btree *p, int newFlag){

  66206.   int b;

  66207.   if( p==0 ) return 0;

  66208.   sqlite3BtreeEnter(p);

  66209.   assert( BTS_OVERWRITE==BTS_SECURE_DELETE*2 );

  66210.   assert( BTS_FAST_SECURE==(BTS_OVERWRITE|BTS_SECURE_DELETE) );

  66211.   if( newFlag>=0 ){

  66212.     p->pBt->btsFlags &= ~BTS_FAST_SECURE;

  66213.     p->pBt->btsFlags |= BTS_SECURE_DELETE*newFlag;

  66214.   }

  66215.   b = (p->pBt->btsFlags & BTS_FAST_SECURE)/BTS_SECURE_DELETE;

  66216.   sqlite3BtreeLeave(p);

  66217.   return b;

  66218. }

  66219. 

  66220. /*

  66221. ** Change the 'auto-vacuum' property of the database. If the 'autoVacuum'

  66222. ** parameter is non-zero, then auto-vacuum mode is enabled. If zero, it

  66223. ** is disabled. The default value for the auto-vacuum property is 

  66224. ** determined by the SQLITE_DEFAULT_AUTOVACUUM macro.

  66225. */

  66226. SQLITE_PRIVATE int sqlite3BtreeSetAutoVacuum(Btree *p, int autoVacuum){

  66227. #ifdef SQLITE_OMIT_AUTOVACUUM

  66228.   return SQLITE_READONLY;

  66229. #else

  66230.   BtShared *pBt = p->pBt;

  66231.   int rc = SQLITE_OK;

  66232.   u8 av = (u8)autoVacuum;

  66233. 

  66234.   sqlite3BtreeEnter(p);

  66235.   if( (pBt->btsFlags & BTS_PAGESIZE_FIXED)!=0 && (av ?1:0)!=pBt->autoVacuum ){

  66236.     rc = SQLITE_READONLY;

  66237.   }else{

  66238.     pBt->autoVacuum = av ?1:0;

  66239.     pBt->incrVacuum = av==2 ?1:0;

  66240.   }

  66241.   sqlite3BtreeLeave(p);

  66242.   return rc;

  66243. #endif

  66244. }

  66245. 

  66246. /*

  66247. ** Return the value of the 'auto-vacuum' property. If auto-vacuum is 

  66248. ** enabled 1 is returned. Otherwise 0.

  66249. */

  66250. SQLITE_PRIVATE int sqlite3BtreeGetAutoVacuum(Btree *p){

  66251. #ifdef SQLITE_OMIT_AUTOVACUUM

  66252.   return BTREE_AUTOVACUUM_NONE;

  66253. #else

  66254.   int rc;

  66255.   sqlite3BtreeEnter(p);

  66256.   rc = (

  66257.     (!p->pBt->autoVacuum)?BTREE_AUTOVACUUM_NONE:

  66258.     (!p->pBt->incrVacuum)?BTREE_AUTOVACUUM_FULL:

  66259.     BTREE_AUTOVACUUM_INCR

  66260.   );

  66261.   sqlite3BtreeLeave(p);

  66262.   return rc;

  66263. #endif

  66264. }

  66265. 

  66266. /*

  66267. ** If the user has not set the safety-level for this database connection

  66268. ** using "PRAGMA synchronous", and if the safety-level is not already

  66269. ** set to the value passed to this function as the second parameter,

  66270. ** set it so.

  66271. */

  66272. #if SQLITE_DEFAULT_SYNCHRONOUS!=SQLITE_DEFAULT_WAL_SYNCHRONOUS \

  66273.     && !defined(SQLITE_OMIT_WAL)

  66274. static void setDefaultSyncFlag(BtShared *pBt, u8 safety_level){

  66275.   sqlite3 *db;

  66276.   Db *pDb;

  66277.   if( (db=pBt->db)!=0 && (pDb=db->aDb)!=0 ){

  66278.     while( pDb->pBt==0 || pDb->pBt->pBt!=pBt ){ pDb++; }

  66279.     if( pDb->bSyncSet==0 

  66280.      && pDb->safety_level!=safety_level 

  66281.      && pDb!=&db->aDb[1] 

  66282.     ){

  66283.       pDb->safety_level = safety_level;

  66284.       sqlite3PagerSetFlags(pBt->pPager,

  66285.           pDb->safety_level | (db->flags & PAGER_FLAGS_MASK));

  66286.     }

  66287.   }

  66288. }

  66289. #else

  66290. # define setDefaultSyncFlag(pBt,safety_level)

  66291. #endif

  66292. 

  66293. /* Forward declaration */

  66294. static int newDatabase(BtShared*);

  66295. 

  66296. 

  66297. /*

  66298. ** Get a reference to pPage1 of the database file.  This will

  66299. ** also acquire a readlock on that file.

  66300. **

  66301. ** SQLITE_OK is returned on success.  If the file is not a

  66302. ** well-formed database file, then SQLITE_CORRUPT is returned.

  66303. ** SQLITE_BUSY is returned if the database is locked.  SQLITE_NOMEM

  66304. ** is returned if we run out of memory. 

  66305. */

  66306. static int lockBtree(BtShared *pBt){

  66307.   int rc;              /* Result code from subfunctions */

  66308.   MemPage *pPage1;     /* Page 1 of the database file */

  66309.   u32 nPage;           /* Number of pages in the database */

  66310.   u32 nPageFile = 0;   /* Number of pages in the database file */

  66311.   u32 nPageHeader;     /* Number of pages in the database according to hdr */

  66312. 

  66313.   assert( sqlite3_mutex_held(pBt->mutex) );

  66314.   assert( pBt->pPage1==0 );

  66315.   rc = sqlite3PagerSharedLock(pBt->pPager);

  66316.   if( rc!=SQLITE_OK ) return rc;

  66317.   rc = btreeGetPage(pBt, 1, &pPage1, 0);

  66318.   if( rc!=SQLITE_OK ) return rc;

  66319. 

  66320.   /* Do some checking to help insure the file we opened really is

  66321.   ** a valid database file. 

  66322.   */

  66323.   nPage = nPageHeader = get4byte(28+(u8*)pPage1->aData);

  66324.   sqlite3PagerPagecount(pBt->pPager, (int*)&nPageFile);

  66325.   if( nPage==0 || memcmp(24+(u8*)pPage1->aData, 92+(u8*)pPage1->aData,4)!=0 ){

  66326.     nPage = nPageFile;

  66327.   }

  66328.   if( (pBt->db->flags & SQLITE_ResetDatabase)!=0 ){

  66329.     nPage = 0;

  66330.   }

  66331.   if( nPage>0 ){

  66332.     u32 pageSize;

  66333.     u32 usableSize;

  66334.     u8 *page1 = pPage1->aData;

  66335.     rc = SQLITE_NOTADB;

  66336.     /* EVIDENCE-OF: R-43737-39999 Every valid SQLite database file begins

  66337.     ** with the following 16 bytes (in hex): 53 51 4c 69 74 65 20 66 6f 72 6d

  66338.     ** 61 74 20 33 00. */

  66339.     if( memcmp(page1, zMagicHeader, 16)!=0 ){

  66340.       goto page1_init_failed;

  66341.     }

  66342. 

  66343. #ifdef SQLITE_OMIT_WAL

  66344.     if( page1[18]>1 ){

  66345.       pBt->btsFlags |= BTS_READ_ONLY;

  66346.     }

  66347.     if( page1[19]>1 ){

  66348.       goto page1_init_failed;

  66349.     }

  66350. #else

  66351.     if( page1[18]>2 ){

  66352.       pBt->btsFlags |= BTS_READ_ONLY;

  66353.     }

  66354.     if( page1[19]>2 ){

  66355.       goto page1_init_failed;

  66356.     }

  66357. 

  66358.     /* If the write version is set to 2, this database should be accessed

  66359.     ** in WAL mode. If the log is not already open, open it now. Then 

  66360.     ** return SQLITE_OK and return without populating BtShared.pPage1.

  66361.     ** The caller detects this and calls this function again. This is

  66362.     ** required as the version of page 1 currently in the page1 buffer

  66363.     ** may not be the latest version - there may be a newer one in the log

  66364.     ** file.

  66365.     */

  66366.     if( page1[19]==2 && (pBt->btsFlags & BTS_NO_WAL)==0 ){

  66367.       int isOpen = 0;

  66368.       rc = sqlite3PagerOpenWal(pBt->pPager, &isOpen);

  66369.       if( rc!=SQLITE_OK ){

  66370.         goto page1_init_failed;

  66371.       }else{

  66372.         setDefaultSyncFlag(pBt, SQLITE_DEFAULT_WAL_SYNCHRONOUS+1);

  66373.         if( isOpen==0 ){

  66374.           releasePageOne(pPage1);

  66375.           return SQLITE_OK;

  66376.         }

  66377.       }

  66378.       rc = SQLITE_NOTADB;

  66379.     }else{

  66380.       setDefaultSyncFlag(pBt, SQLITE_DEFAULT_SYNCHRONOUS+1);

  66381.     }

  66382. #endif

  66383. 

  66384.     /* EVIDENCE-OF: R-15465-20813 The maximum and minimum embedded payload

  66385.     ** fractions and the leaf payload fraction values must be 64, 32, and 32.

  66386.     **

  66387.     ** The original design allowed these amounts to vary, but as of

  66388.     ** version 3.6.0, we require them to be fixed.

  66389.     */

  66390.     if( memcmp(&page1[21], "\100\040\040",3)!=0 ){

  66391.       goto page1_init_failed;

  66392.     }

  66393.     /* EVIDENCE-OF: R-51873-39618 The page size for a database file is

  66394.     ** determined by the 2-byte integer located at an offset of 16 bytes from

  66395.     ** the beginning of the database file. */

  66396.     pageSize = (page1[16]<<8) | (page1[17]<<16);

  66397.     /* EVIDENCE-OF: R-25008-21688 The size of a page is a power of two

  66398.     ** between 512 and 65536 inclusive. */

  66399.     if( ((pageSize-1)&pageSize)!=0

  66400.      || pageSize>SQLITE_MAX_PAGE_SIZE 

  66401.      || pageSize<=256 

  66402.     ){

  66403.       goto page1_init_failed;

  66404.     }

  66405.     pBt->btsFlags |= BTS_PAGESIZE_FIXED;

  66406.     assert( (pageSize & 7)==0 );

  66407.     /* EVIDENCE-OF: R-59310-51205 The "reserved space" size in the 1-byte

  66408.     ** integer at offset 20 is the number of bytes of space at the end of

  66409.     ** each page to reserve for extensions. 

  66410.     **

  66411.     ** EVIDENCE-OF: R-37497-42412 The size of the reserved region is

  66412.     ** determined by the one-byte unsigned integer found at an offset of 20

  66413.     ** into the database file header. */

  66414.     usableSize = pageSize - page1[20];

  66415.     if( (u32)pageSize!=pBt->pageSize ){

  66416.       /* After reading the first page of the database assuming a page size

  66417.       ** of BtShared.pageSize, we have discovered that the page-size is

  66418.       ** actually pageSize. Unlock the database, leave pBt->pPage1 at

  66419.       ** zero and return SQLITE_OK. The caller will call this function

  66420.       ** again with the correct page-size.

  66421.       */

  66422.       releasePageOne(pPage1);

  66423.       pBt->usableSize = usableSize;

  66424.       pBt->pageSize = pageSize;

  66425.       freeTempSpace(pBt);

  66426.       rc = sqlite3PagerSetPagesize(pBt->pPager, &pBt->pageSize,

  66427.                                    pageSize-usableSize);

  66428.       return rc;

  66429.     }

  66430.     if( sqlite3WritableSchema(pBt->db)==0 && nPage>nPageFile ){

  66431.       rc = SQLITE_CORRUPT_BKPT;

  66432.       goto page1_init_failed;

  66433.     }

  66434.     /* EVIDENCE-OF: R-28312-64704 However, the usable size is not allowed to

  66435.     ** be less than 480. In other words, if the page size is 512, then the

  66436.     ** reserved space size cannot exceed 32. */

  66437.     if( usableSize<480 ){

  66438.       goto page1_init_failed;

  66439.     }

  66440.     pBt->pageSize = pageSize;

  66441.     pBt->usableSize = usableSize;

  66442. #ifndef SQLITE_OMIT_AUTOVACUUM

  66443.     pBt->autoVacuum = (get4byte(&page1[36 + 4*4])?1:0);

  66444.     pBt->incrVacuum = (get4byte(&page1[36 + 7*4])?1:0);

  66445. #endif

  66446.   }

  66447. 

  66448.   /* maxLocal is the maximum amount of payload to store locally for

  66449.   ** a cell.  Make sure it is small enough so that at least minFanout

  66450.   ** cells can will fit on one page.  We assume a 10-byte page header.

  66451.   ** Besides the payload, the cell must store:

  66452.   **     2-byte pointer to the cell

  66453.   **     4-byte child pointer

  66454.   **     9-byte nKey value

  66455.   **     4-byte nData value

  66456.   **     4-byte overflow page pointer

  66457.   ** So a cell consists of a 2-byte pointer, a header which is as much as

  66458.   ** 17 bytes long, 0 to N bytes of payload, and an optional 4 byte overflow

  66459.   ** page pointer.

  66460.   */

  66461.   pBt->maxLocal = (u16)((pBt->usableSize-12)*64/255 - 23);

  66462.   pBt->minLocal = (u16)((pBt->usableSize-12)*32/255 - 23);

  66463.   pBt->maxLeaf = (u16)(pBt->usableSize - 35);

  66464.   pBt->minLeaf = (u16)((pBt->usableSize-12)*32/255 - 23);

  66465.   if( pBt->maxLocal>127 ){

  66466.     pBt->max1bytePayload = 127;

  66467.   }else{

  66468.     pBt->max1bytePayload = (u8)pBt->maxLocal;

  66469.   }

  66470.   assert( pBt->maxLeaf + 23 <= MX_CELL_SIZE(pBt) );

  66471.   pBt->pPage1 = pPage1;

  66472.   pBt->nPage = nPage;

  66473.   return SQLITE_OK;

  66474. 

  66475. page1_init_failed:

  66476.   releasePageOne(pPage1);

  66477.   pBt->pPage1 = 0;

  66478.   return rc;

  66479. }

  66480. 

  66481. #ifndef NDEBUG

  66482. /*

  66483. ** Return the number of cursors open on pBt. This is for use

  66484. ** in assert() expressions, so it is only compiled if NDEBUG is not

  66485. ** defined.

  66486. **

  66487. ** Only write cursors are counted if wrOnly is true.  If wrOnly is

  66488. ** false then all cursors are counted.

  66489. **

  66490. ** For the purposes of this routine, a cursor is any cursor that

  66491. ** is capable of reading or writing to the database.  Cursors that

  66492. ** have been tripped into the CURSOR_FAULT state are not counted.

  66493. */

  66494. static int countValidCursors(BtShared *pBt, int wrOnly){

  66495.   BtCursor *pCur;

  66496.   int r = 0;

  66497.   for(pCur=pBt->pCursor; pCur; pCur=pCur->pNext){

  66498.     if( (wrOnly==0 || (pCur->curFlags & BTCF_WriteFlag)!=0)

  66499.      && pCur->eState!=CURSOR_FAULT ) r++; 

  66500.   }

  66501.   return r;

  66502. }

  66503. #endif

  66504. 

  66505. /*

  66506. ** If there are no outstanding cursors and we are not in the middle

  66507. ** of a transaction but there is a read lock on the database, then

  66508. ** this routine unrefs the first page of the database file which 

  66509. ** has the effect of releasing the read lock.

  66510. **

  66511. ** If there is a transaction in progress, this routine is a no-op.

  66512. */

  66513. static void unlockBtreeIfUnused(BtShared *pBt){

  66514.   assert( sqlite3_mutex_held(pBt->mutex) );

  66515.   assert( countValidCursors(pBt,0)==0 || pBt->inTransaction>TRANS_NONE );

  66516.   if( pBt->inTransaction==TRANS_NONE && pBt->pPage1!=0 ){

  66517.     MemPage *pPage1 = pBt->pPage1;

  66518.     assert( pPage1->aData );

  66519.     assert( sqlite3PagerRefcount(pBt->pPager)==1 );

  66520.     pBt->pPage1 = 0;

  66521.     releasePageOne(pPage1);

  66522.   }

  66523. }

  66524. 

  66525. /*

  66526. ** If pBt points to an empty file then convert that empty file

  66527. ** into a new empty database by initializing the first page of

  66528. ** the database.

  66529. */

  66530. static int newDatabase(BtShared *pBt){

  66531.   MemPage *pP1;

  66532.   unsigned char *data;

  66533.   int rc;

  66534. 

  66535.   assert( sqlite3_mutex_held(pBt->mutex) );

  66536.   if( pBt->nPage>0 ){

  66537.     return SQLITE_OK;

  66538.   }

  66539.   pP1 = pBt->pPage1;

  66540.   assert( pP1!=0 );

  66541.   data = pP1->aData;

  66542.   rc = sqlite3PagerWrite(pP1->pDbPage);

  66543.   if( rc ) return rc;

  66544.   memcpy(data, zMagicHeader, sizeof(zMagicHeader));

  66545.   assert( sizeof(zMagicHeader)==16 );

  66546.   data[16] = (u8)((pBt->pageSize>>8)&0xff);

  66547.   data[17] = (u8)((pBt->pageSize>>16)&0xff);

  66548.   data[18] = 1;

  66549.   data[19] = 1;

  66550.   assert( pBt->usableSize<=pBt->pageSize && pBt->usableSize+255>=pBt->pageSize);

  66551.   data[20] = (u8)(pBt->pageSize - pBt->usableSize);

  66552.   data[21] = 64;

  66553.   data[22] = 32;

  66554.   data[23] = 32;

  66555.   memset(&data[24], 0, 100-24);

  66556.   zeroPage(pP1, PTF_INTKEY|PTF_LEAF|PTF_LEAFDATA );

  66557.   pBt->btsFlags |= BTS_PAGESIZE_FIXED;

  66558. #ifndef SQLITE_OMIT_AUTOVACUUM

  66559.   assert( pBt->autoVacuum==1 || pBt->autoVacuum==0 );

  66560.   assert( pBt->incrVacuum==1 || pBt->incrVacuum==0 );

  66561.   put4byte(&data[36 + 4*4], pBt->autoVacuum);

  66562.   put4byte(&data[36 + 7*4], pBt->incrVacuum);

  66563. #endif

  66564.   pBt->nPage = 1;

  66565.   data[31] = 1;

  66566.   return SQLITE_OK;

  66567. }

  66568. 

  66569. /*

  66570. ** Initialize the first page of the database file (creating a database

  66571. ** consisting of a single page and no schema objects). Return SQLITE_OK

  66572. ** if successful, or an SQLite error code otherwise.

  66573. */

  66574. SQLITE_PRIVATE int sqlite3BtreeNewDb(Btree *p){

  66575.   int rc;

  66576.   sqlite3BtreeEnter(p);

  66577.   p->pBt->nPage = 0;

  66578.   rc = newDatabase(p->pBt);

  66579.   sqlite3BtreeLeave(p);

  66580.   return rc;

  66581. }

  66582. 

  66583. /*

  66584. ** Attempt to start a new transaction. A write-transaction

  66585. ** is started if the second argument is nonzero, otherwise a read-

  66586. ** transaction.  If the second argument is 2 or more and exclusive

  66587. ** transaction is started, meaning that no other process is allowed

  66588. ** to access the database.  A preexisting transaction may not be

  66589. ** upgraded to exclusive by calling this routine a second time - the

  66590. ** exclusivity flag only works for a new transaction.

  66591. **

  66592. ** A write-transaction must be started before attempting any 

  66593. ** changes to the database.  None of the following routines 

  66594. ** will work unless a transaction is started first:

  66595. **

  66596. **      sqlite3BtreeCreateTable()

  66597. **      sqlite3BtreeCreateIndex()

  66598. **      sqlite3BtreeClearTable()

  66599. **      sqlite3BtreeDropTable()

  66600. **      sqlite3BtreeInsert()

  66601. **      sqlite3BtreeDelete()

  66602. **      sqlite3BtreeUpdateMeta()

  66603. **

  66604. ** If an initial attempt to acquire the lock fails because of lock contention

  66605. ** and the database was previously unlocked, then invoke the busy handler

  66606. ** if there is one.  But if there was previously a read-lock, do not

  66607. ** invoke the busy handler - just return SQLITE_BUSY.  SQLITE_BUSY is 

  66608. ** returned when there is already a read-lock in order to avoid a deadlock.

  66609. **

  66610. ** Suppose there are two processes A and B.  A has a read lock and B has

  66611. ** a reserved lock.  B tries to promote to exclusive but is blocked because

  66612. ** of A's read lock.  A tries to promote to reserved but is blocked by B.

  66613. ** One or the other of the two processes must give way or there can be

  66614. ** no progress.  By returning SQLITE_BUSY and not invoking the busy callback

  66615. ** when A already has a read lock, we encourage A to give up and let B

  66616. ** proceed.

  66617. */

  66618. SQLITE_PRIVATE int sqlite3BtreeBeginTrans(Btree *p, int wrflag, int *pSchemaVersion){

  66619.   BtShared *pBt = p->pBt;

  66620.   int rc = SQLITE_OK;

  66621. 

  66622.   sqlite3BtreeEnter(p);

  66623.   btreeIntegrity(p);

  66624. 

  66625.   /* If the btree is already in a write-transaction, or it

  66626.   ** is already in a read-transaction and a read-transaction

  66627.   ** is requested, this is a no-op.

  66628.   */

  66629.   if( p->inTrans==TRANS_WRITE || (p->inTrans==TRANS_READ && !wrflag) ){

  66630.     goto trans_begun;

  66631.   }

  66632.   assert( pBt->inTransaction==TRANS_WRITE || IfNotOmitAV(pBt->bDoTruncate)==0 );

  66633. 

  66634.   if( (p->db->flags & SQLITE_ResetDatabase) 

  66635.    && sqlite3PagerIsreadonly(pBt->pPager)==0 

  66636.   ){

  66637.     pBt->btsFlags &= ~BTS_READ_ONLY;

  66638.   }

  66639. 

  66640.   /* Write transactions are not possible on a read-only database */

  66641.   if( (pBt->btsFlags & BTS_READ_ONLY)!=0 && wrflag ){

  66642.     rc = SQLITE_READONLY;

  66643.     goto trans_begun;

  66644.   }

  66645. 

  66646. #ifndef SQLITE_OMIT_SHARED_CACHE

  66647.   {

  66648.     sqlite3 *pBlock = 0;

  66649.     /* If another database handle has already opened a write transaction 

  66650.     ** on this shared-btree structure and a second write transaction is

  66651.     ** requested, return SQLITE_LOCKED.

  66652.     */

  66653.     if( (wrflag && pBt->inTransaction==TRANS_WRITE)

  66654.      || (pBt->btsFlags & BTS_PENDING)!=0

  66655.     ){

  66656.       pBlock = pBt->pWriter->db;

  66657.     }else if( wrflag>1 ){

  66658.       BtLock *pIter;

  66659.       for(pIter=pBt->pLock; pIter; pIter=pIter->pNext){

  66660.         if( pIter->pBtree!=p ){

  66661.           pBlock = pIter->pBtree->db;

  66662.           break;

  66663.         }

  66664.       }

  66665.     }

  66666.     if( pBlock ){

  66667.       sqlite3ConnectionBlocked(p->db, pBlock);

  66668.       rc = SQLITE_LOCKED_SHAREDCACHE;

  66669.       goto trans_begun;

  66670.     }

  66671.   }

  66672. #endif

  66673. 

  66674.   /* Any read-only or read-write transaction implies a read-lock on 

  66675.   ** page 1. So if some other shared-cache client already has a write-lock 

  66676.   ** on page 1, the transaction cannot be opened. */

  66677.   rc = querySharedCacheTableLock(p, MASTER_ROOT, READ_LOCK);

  66678.   if( SQLITE_OK!=rc ) goto trans_begun;

  66679. 

  66680.   pBt->btsFlags &= ~BTS_INITIALLY_EMPTY;

  66681.   if( pBt->nPage==0 ) pBt->btsFlags |= BTS_INITIALLY_EMPTY;

  66682.   do {

  66683.     /* Call lockBtree() until either pBt->pPage1 is populated or

  66684.     ** lockBtree() returns something other than SQLITE_OK. lockBtree()

  66685.     ** may return SQLITE_OK but leave pBt->pPage1 set to 0 if after

  66686.     ** reading page 1 it discovers that the page-size of the database 

  66687.     ** file is not pBt->pageSize. In this case lockBtree() will update

  66688.     ** pBt->pageSize to the page-size of the file on disk.

  66689.     */

  66690.     while( pBt->pPage1==0 && SQLITE_OK==(rc = lockBtree(pBt)) );

  66691. 

  66692.     if( rc==SQLITE_OK && wrflag ){

  66693.       if( (pBt->btsFlags & BTS_READ_ONLY)!=0 ){

  66694.         rc = SQLITE_READONLY;

  66695.       }else{

  66696.         rc = sqlite3PagerBegin(pBt->pPager,wrflag>1,sqlite3TempInMemory(p->db));

  66697.         if( rc==SQLITE_OK ){

  66698.           rc = newDatabase(pBt);

  66699.         }else if( rc==SQLITE_BUSY_SNAPSHOT && pBt->inTransaction==TRANS_NONE ){

  66700.           /* if there was no transaction opened when this function was

  66701.           ** called and SQLITE_BUSY_SNAPSHOT is returned, change the error

  66702.           ** code to SQLITE_BUSY. */

  66703.           rc = SQLITE_BUSY;

  66704.         }

  66705.       }

  66706.     }

  66707.   

  66708.     if( rc!=SQLITE_OK ){

  66709.       unlockBtreeIfUnused(pBt);

  66710.     }

  66711.   }while( (rc&0xFF)==SQLITE_BUSY && pBt->inTransaction==TRANS_NONE &&

  66712.           btreeInvokeBusyHandler(pBt) );

  66713.   sqlite3PagerResetLockTimeout(pBt->pPager);

  66714. 

  66715.   if( rc==SQLITE_OK ){

  66716.     if( p->inTrans==TRANS_NONE ){

  66717.       pBt->nTransaction++;

  66718. #ifndef SQLITE_OMIT_SHARED_CACHE

  66719.       if( p->sharable ){

  66720.         assert( p->lock.pBtree==p && p->lock.iTable==1 );

  66721.         p->lock.eLock = READ_LOCK;

  66722.         p->lock.pNext = pBt->pLock;

  66723.         pBt->pLock = &p->lock;

  66724.       }

  66725. #endif

  66726.     }

  66727.     p->inTrans = (wrflag?TRANS_WRITE:TRANS_READ);

  66728.     if( p->inTrans>pBt->inTransaction ){

  66729.       pBt->inTransaction = p->inTrans;

  66730.     }

  66731.     if( wrflag ){

  66732.       MemPage *pPage1 = pBt->pPage1;

  66733. #ifndef SQLITE_OMIT_SHARED_CACHE

  66734.       assert( !pBt->pWriter );

  66735.       pBt->pWriter = p;

  66736.       pBt->btsFlags &= ~BTS_EXCLUSIVE;

  66737.       if( wrflag>1 ) pBt->btsFlags |= BTS_EXCLUSIVE;

  66738. #endif

  66739. 

  66740.       /* If the db-size header field is incorrect (as it may be if an old

  66741.       ** client has been writing the database file), update it now. Doing

  66742.       ** this sooner rather than later means the database size can safely 

  66743.       ** re-read the database size from page 1 if a savepoint or transaction

  66744.       ** rollback occurs within the transaction.

  66745.       */

  66746.       if( pBt->nPage!=get4byte(&pPage1->aData[28]) ){

  66747.         rc = sqlite3PagerWrite(pPage1->pDbPage);

  66748.         if( rc==SQLITE_OK ){

  66749.           put4byte(&pPage1->aData[28], pBt->nPage);

  66750.         }

  66751.       }

  66752.     }

  66753.   }

  66754. 

  66755. trans_begun:

  66756.   if( rc==SQLITE_OK ){

  66757.     if( pSchemaVersion ){

  66758.       *pSchemaVersion = get4byte(&pBt->pPage1->aData[40]);

  66759.     }

  66760.     if( wrflag ){

  66761.       /* This call makes sure that the pager has the correct number of

  66762.       ** open savepoints. If the second parameter is greater than 0 and

  66763.       ** the sub-journal is not already open, then it will be opened here.

  66764.       */

  66765.       rc = sqlite3PagerOpenSavepoint(pBt->pPager, p->db->nSavepoint);

  66766.     }

  66767.   }

  66768. 

  66769.   btreeIntegrity(p);

  66770.   sqlite3BtreeLeave(p);

  66771.   return rc;

  66772. }

  66773. 

  66774. #ifndef SQLITE_OMIT_AUTOVACUUM

  66775. 

  66776. /*

  66777. ** Set the pointer-map entries for all children of page pPage. Also, if

  66778. ** pPage contains cells that point to overflow pages, set the pointer

  66779. ** map entries for the overflow pages as well.

  66780. */

  66781. static int setChildPtrmaps(MemPage *pPage){

  66782.   int i;                             /* Counter variable */

  66783.   int nCell;                         /* Number of cells in page pPage */

  66784.   int rc;                            /* Return code */

  66785.   BtShared *pBt = pPage->pBt;

  66786.   Pgno pgno = pPage->pgno;

  66787. 

  66788.   assert( sqlite3_mutex_held(pPage->pBt->mutex) );

  66789.   rc = pPage->isInit ? SQLITE_OK : btreeInitPage(pPage);

  66790.   if( rc!=SQLITE_OK ) return rc;

  66791.   nCell = pPage->nCell;

  66792. 

  66793.   for(i=0; i<nCell; i++){

  66794.     u8 *pCell = findCell(pPage, i);

  66795. 

  66796.     ptrmapPutOvflPtr(pPage, pPage, pCell, &rc);

  66797. 

  66798.     if( !pPage->leaf ){

  66799.       Pgno childPgno = get4byte(pCell);

  66800.       ptrmapPut(pBt, childPgno, PTRMAP_BTREE, pgno, &rc);

  66801.     }

  66802.   }

  66803. 

  66804.   if( !pPage->leaf ){

  66805.     Pgno childPgno = get4byte(&pPage->aData[pPage->hdrOffset+8]);

  66806.     ptrmapPut(pBt, childPgno, PTRMAP_BTREE, pgno, &rc);

  66807.   }

  66808. 

  66809.   return rc;

  66810. }

  66811. 

  66812. /*

  66813. ** Somewhere on pPage is a pointer to page iFrom.  Modify this pointer so

  66814. ** that it points to iTo. Parameter eType describes the type of pointer to

  66815. ** be modified, as  follows:

  66816. **

  66817. ** PTRMAP_BTREE:     pPage is a btree-page. The pointer points at a child 

  66818. **                   page of pPage.

  66819. **

  66820. ** PTRMAP_OVERFLOW1: pPage is a btree-page. The pointer points at an overflow

  66821. **                   page pointed to by one of the cells on pPage.

  66822. **

  66823. ** PTRMAP_OVERFLOW2: pPage is an overflow-page. The pointer points at the next

  66824. **                   overflow page in the list.

  66825. */

  66826. static int modifyPagePointer(MemPage *pPage, Pgno iFrom, Pgno iTo, u8 eType){

  66827.   assert( sqlite3_mutex_held(pPage->pBt->mutex) );

  66828.   assert( sqlite3PagerIswriteable(pPage->pDbPage) );

  66829.   if( eType==PTRMAP_OVERFLOW2 ){

  66830.     /* The pointer is always the first 4 bytes of the page in this case.  */

  66831.     if( get4byte(pPage->aData)!=iFrom ){

  66832.       return SQLITE_CORRUPT_PAGE(pPage);

  66833.     }

  66834.     put4byte(pPage->aData, iTo);

  66835.   }else{

  66836.     int i;

  66837.     int nCell;

  66838.     int rc;

  66839. 

  66840.     rc = pPage->isInit ? SQLITE_OK : btreeInitPage(pPage);

  66841.     if( rc ) return rc;

  66842.     nCell = pPage->nCell;

  66843. 

  66844.     for(i=0; i<nCell; i++){

  66845.       u8 *pCell = findCell(pPage, i);

  66846.       if( eType==PTRMAP_OVERFLOW1 ){

  66847.         CellInfo info;

  66848.         pPage->xParseCell(pPage, pCell, &info);

  66849.         if( info.nLocal<info.nPayload ){

  66850.           if( pCell+info.nSize > pPage->aData+pPage->pBt->usableSize ){

  66851.             return SQLITE_CORRUPT_PAGE(pPage);

  66852.           }

  66853.           if( iFrom==get4byte(pCell+info.nSize-4) ){

  66854.             put4byte(pCell+info.nSize-4, iTo);

  66855.             break;

  66856.           }

  66857.         }

  66858.       }else{

  66859.         if( get4byte(pCell)==iFrom ){

  66860.           put4byte(pCell, iTo);

  66861.           break;

  66862.         }

  66863.       }

  66864.     }

  66865.   

  66866.     if( i==nCell ){

  66867.       if( eType!=PTRMAP_BTREE || 

  66868.           get4byte(&pPage->aData[pPage->hdrOffset+8])!=iFrom ){

  66869.         return SQLITE_CORRUPT_PAGE(pPage);

  66870.       }

  66871.       put4byte(&pPage->aData[pPage->hdrOffset+8], iTo);

  66872.     }

  66873.   }

  66874.   return SQLITE_OK;

  66875. }

  66876. 

  66877. 

  66878. /*

  66879. ** Move the open database page pDbPage to location iFreePage in the 

  66880. ** database. The pDbPage reference remains valid.

  66881. **

  66882. ** The isCommit flag indicates that there is no need to remember that

  66883. ** the journal needs to be sync()ed before database page pDbPage->pgno 

  66884. ** can be written to. The caller has already promised not to write to that

  66885. ** page.

  66886. */

  66887. static int relocatePage(

  66888.   BtShared *pBt,           /* Btree */

  66889.   MemPage *pDbPage,        /* Open page to move */

  66890.   u8 eType,                /* Pointer map 'type' entry for pDbPage */

  66891.   Pgno iPtrPage,           /* Pointer map 'page-no' entry for pDbPage */

  66892.   Pgno iFreePage,          /* The location to move pDbPage to */

  66893.   int isCommit             /* isCommit flag passed to sqlite3PagerMovepage */

  66894. ){

  66895.   MemPage *pPtrPage;   /* The page that contains a pointer to pDbPage */

  66896.   Pgno iDbPage = pDbPage->pgno;

  66897.   Pager *pPager = pBt->pPager;

  66898.   int rc;

  66899. 

  66900.   assert( eType==PTRMAP_OVERFLOW2 || eType==PTRMAP_OVERFLOW1 || 

  66901.       eType==PTRMAP_BTREE || eType==PTRMAP_ROOTPAGE );

  66902.   assert( sqlite3_mutex_held(pBt->mutex) );

  66903.   assert( pDbPage->pBt==pBt );

  66904.   if( iDbPage<3 ) return SQLITE_CORRUPT_BKPT;

  66905. 

  66906.   /* Move page iDbPage from its current location to page number iFreePage */

  66907.   TRACE(("AUTOVACUUM: Moving %d to free page %d (ptr page %d type %d)\n", 

  66908.       iDbPage, iFreePage, iPtrPage, eType));

  66909.   rc = sqlite3PagerMovepage(pPager, pDbPage->pDbPage, iFreePage, isCommit);

  66910.   if( rc!=SQLITE_OK ){

  66911.     return rc;

  66912.   }

  66913.   pDbPage->pgno = iFreePage;

  66914. 

  66915.   /* If pDbPage was a btree-page, then it may have child pages and/or cells

  66916.   ** that point to overflow pages. The pointer map entries for all these

  66917.   ** pages need to be changed.

  66918.   **

  66919.   ** If pDbPage is an overflow page, then the first 4 bytes may store a

  66920.   ** pointer to a subsequent overflow page. If this is the case, then

  66921.   ** the pointer map needs to be updated for the subsequent overflow page.

  66922.   */

  66923.   if( eType==PTRMAP_BTREE || eType==PTRMAP_ROOTPAGE ){

  66924.     rc = setChildPtrmaps(pDbPage);

  66925.     if( rc!=SQLITE_OK ){

  66926.       return rc;

  66927.     }

  66928.   }else{

  66929.     Pgno nextOvfl = get4byte(pDbPage->aData);

  66930.     if( nextOvfl!=0 ){

  66931.       ptrmapPut(pBt, nextOvfl, PTRMAP_OVERFLOW2, iFreePage, &rc);

  66932.       if( rc!=SQLITE_OK ){

  66933.         return rc;

  66934.       }

  66935.     }

  66936.   }

  66937. 

  66938.   /* Fix the database pointer on page iPtrPage that pointed at iDbPage so

  66939.   ** that it points at iFreePage. Also fix the pointer map entry for

  66940.   ** iPtrPage.

  66941.   */

  66942.   if( eType!=PTRMAP_ROOTPAGE ){

  66943.     rc = btreeGetPage(pBt, iPtrPage, &pPtrPage, 0);

  66944.     if( rc!=SQLITE_OK ){

  66945.       return rc;

  66946.     }

  66947.     rc = sqlite3PagerWrite(pPtrPage->pDbPage);

  66948.     if( rc!=SQLITE_OK ){

  66949.       releasePage(pPtrPage);

  66950.       return rc;

  66951.     }

  66952.     rc = modifyPagePointer(pPtrPage, iDbPage, iFreePage, eType);

  66953.     releasePage(pPtrPage);

  66954.     if( rc==SQLITE_OK ){

  66955.       ptrmapPut(pBt, iFreePage, eType, iPtrPage, &rc);

  66956.     }

  66957.   }

  66958.   return rc;

  66959. }

  66960. 

  66961. /* Forward declaration required by incrVacuumStep(). */

  66962. static int allocateBtreePage(BtShared *, MemPage **, Pgno *, Pgno, u8);

  66963. 

  66964. /*

  66965. ** Perform a single step of an incremental-vacuum. If successful, return

  66966. ** SQLITE_OK. If there is no work to do (and therefore no point in 

  66967. ** calling this function again), return SQLITE_DONE. Or, if an error 

  66968. ** occurs, return some other error code.

  66969. **

  66970. ** More specifically, this function attempts to re-organize the database so 

  66971. ** that the last page of the file currently in use is no longer in use.

  66972. **

  66973. ** Parameter nFin is the number of pages that this database would contain

  66974. ** were this function called until it returns SQLITE_DONE.

  66975. **

  66976. ** If the bCommit parameter is non-zero, this function assumes that the 

  66977. ** caller will keep calling incrVacuumStep() until it returns SQLITE_DONE 

  66978. ** or an error. bCommit is passed true for an auto-vacuum-on-commit 

  66979. ** operation, or false for an incremental vacuum.

  66980. */

  66981. static int incrVacuumStep(BtShared *pBt, Pgno nFin, Pgno iLastPg, int bCommit){

  66982.   Pgno nFreeList;           /* Number of pages still on the free-list */

  66983.   int rc;

  66984. 

  66985.   assert( sqlite3_mutex_held(pBt->mutex) );

  66986.   assert( iLastPg>nFin );

  66987. 

  66988.   if( !PTRMAP_ISPAGE(pBt, iLastPg) && iLastPg!=PENDING_BYTE_PAGE(pBt) ){

  66989.     u8 eType;

  66990.     Pgno iPtrPage;

  66991. 

  66992.     nFreeList = get4byte(&pBt->pPage1->aData[36]);

  66993.     if( nFreeList==0 ){

  66994.       return SQLITE_DONE;

  66995.     }

  66996. 

  66997.     rc = ptrmapGet(pBt, iLastPg, &eType, &iPtrPage);

  66998.     if( rc!=SQLITE_OK ){

  66999.       return rc;

  67000.     }

  67001.     if( eType==PTRMAP_ROOTPAGE ){

  67002.       return SQLITE_CORRUPT_BKPT;

  67003.     }

  67004. 

  67005.     if( eType==PTRMAP_FREEPAGE ){

  67006.       if( bCommit==0 ){

  67007.         /* Remove the page from the files free-list. This is not required

  67008.         ** if bCommit is non-zero. In that case, the free-list will be

  67009.         ** truncated to zero after this function returns, so it doesn't 

  67010.         ** matter if it still contains some garbage entries.

  67011.         */

  67012.         Pgno iFreePg;

  67013.         MemPage *pFreePg;

  67014.         rc = allocateBtreePage(pBt, &pFreePg, &iFreePg, iLastPg, BTALLOC_EXACT);

  67015.         if( rc!=SQLITE_OK ){

  67016.           return rc;

  67017.         }

  67018.         assert( iFreePg==iLastPg );

  67019.         releasePage(pFreePg);

  67020.       }

  67021.     } else {

  67022.       Pgno iFreePg;             /* Index of free page to move pLastPg to */

  67023.       MemPage *pLastPg;

  67024.       u8 eMode = BTALLOC_ANY;   /* Mode parameter for allocateBtreePage() */

  67025.       Pgno iNear = 0;           /* nearby parameter for allocateBtreePage() */

  67026. 

  67027.       rc = btreeGetPage(pBt, iLastPg, &pLastPg, 0);

  67028.       if( rc!=SQLITE_OK ){

  67029.         return rc;

  67030.       }

  67031. 

  67032.       /* If bCommit is zero, this loop runs exactly once and page pLastPg

  67033.       ** is swapped with the first free page pulled off the free list.

  67034.       **

  67035.       ** On the other hand, if bCommit is greater than zero, then keep

  67036.       ** looping until a free-page located within the first nFin pages

  67037.       ** of the file is found.

  67038.       */

  67039.       if( bCommit==0 ){

  67040.         eMode = BTALLOC_LE;

  67041.         iNear = nFin;

  67042.       }

  67043.       do {

  67044.         MemPage *pFreePg;

  67045.         rc = allocateBtreePage(pBt, &pFreePg, &iFreePg, iNear, eMode);

  67046.         if( rc!=SQLITE_OK ){

  67047.           releasePage(pLastPg);

  67048.           return rc;

  67049.         }

  67050.         releasePage(pFreePg);

  67051.       }while( bCommit && iFreePg>nFin );

  67052.       assert( iFreePg<iLastPg );

  67053.       

  67054.       rc = relocatePage(pBt, pLastPg, eType, iPtrPage, iFreePg, bCommit);

  67055.       releasePage(pLastPg);

  67056.       if( rc!=SQLITE_OK ){

  67057.         return rc;

  67058.       }

  67059.     }

  67060.   }

  67061. 

  67062.   if( bCommit==0 ){

  67063.     do {

  67064.       iLastPg--;

  67065.     }while( iLastPg==PENDING_BYTE_PAGE(pBt) || PTRMAP_ISPAGE(pBt, iLastPg) );

  67066.     pBt->bDoTruncate = 1;

  67067.     pBt->nPage = iLastPg;

  67068.   }

  67069.   return SQLITE_OK;

  67070. }

  67071. 

  67072. /*

  67073. ** The database opened by the first argument is an auto-vacuum database

  67074. ** nOrig pages in size containing nFree free pages. Return the expected 

  67075. ** size of the database in pages following an auto-vacuum operation.

  67076. */

  67077. static Pgno finalDbSize(BtShared *pBt, Pgno nOrig, Pgno nFree){

  67078.   int nEntry;                     /* Number of entries on one ptrmap page */

  67079.   Pgno nPtrmap;                   /* Number of PtrMap pages to be freed */

  67080.   Pgno nFin;                      /* Return value */

  67081. 

  67082.   nEntry = pBt->usableSize/5;

  67083.   nPtrmap = (nFree-nOrig+PTRMAP_PAGENO(pBt, nOrig)+nEntry)/nEntry;

  67084.   nFin = nOrig - nFree - nPtrmap;

  67085.   if( nOrig>PENDING_BYTE_PAGE(pBt) && nFin<PENDING_BYTE_PAGE(pBt) ){

  67086.     nFin--;

  67087.   }

  67088.   while( PTRMAP_ISPAGE(pBt, nFin) || nFin==PENDING_BYTE_PAGE(pBt) ){

  67089.     nFin--;

  67090.   }

  67091. 

  67092.   return nFin;

  67093. }

  67094. 

  67095. /*

  67096. ** A write-transaction must be opened before calling this function.

  67097. ** It performs a single unit of work towards an incremental vacuum.

  67098. **

  67099. ** If the incremental vacuum is finished after this function has run,

  67100. ** SQLITE_DONE is returned. If it is not finished, but no error occurred,

  67101. ** SQLITE_OK is returned. Otherwise an SQLite error code. 

  67102. */

  67103. SQLITE_PRIVATE int sqlite3BtreeIncrVacuum(Btree *p){

  67104.   int rc;

  67105.   BtShared *pBt = p->pBt;

  67106. 

  67107.   sqlite3BtreeEnter(p);

  67108.   assert( pBt->inTransaction==TRANS_WRITE && p->inTrans==TRANS_WRITE );

  67109.   if( !pBt->autoVacuum ){

  67110.     rc = SQLITE_DONE;

  67111.   }else{

  67112.     Pgno nOrig = btreePagecount(pBt);

  67113.     Pgno nFree = get4byte(&pBt->pPage1->aData[36]);

  67114.     Pgno nFin = finalDbSize(pBt, nOrig, nFree);

  67115. 

  67116.     if( nOrig<nFin ){

  67117.       rc = SQLITE_CORRUPT_BKPT;

  67118.     }else if( nFree>0 ){

  67119.       rc = saveAllCursors(pBt, 0, 0);

  67120.       if( rc==SQLITE_OK ){

  67121.         invalidateAllOverflowCache(pBt);

  67122.         rc = incrVacuumStep(pBt, nFin, nOrig, 0);

  67123.       }

  67124.       if( rc==SQLITE_OK ){

  67125.         rc = sqlite3PagerWrite(pBt->pPage1->pDbPage);

  67126.         put4byte(&pBt->pPage1->aData[28], pBt->nPage);

  67127.       }

  67128.     }else{

  67129.       rc = SQLITE_DONE;

  67130.     }

  67131.   }

  67132.   sqlite3BtreeLeave(p);

  67133.   return rc;

  67134. }

  67135. 

  67136. /*

  67137. ** This routine is called prior to sqlite3PagerCommit when a transaction

  67138. ** is committed for an auto-vacuum database.

  67139. **

  67140. ** If SQLITE_OK is returned, then *pnTrunc is set to the number of pages

  67141. ** the database file should be truncated to during the commit process. 

  67142. ** i.e. the database has been reorganized so that only the first *pnTrunc

  67143. ** pages are in use.

  67144. */

  67145. static int autoVacuumCommit(BtShared *pBt){

  67146.   int rc = SQLITE_OK;

  67147.   Pager *pPager = pBt->pPager;

  67148.   VVA_ONLY( int nRef = sqlite3PagerRefcount(pPager); )

  67149. 

  67150.   assert( sqlite3_mutex_held(pBt->mutex) );

  67151.   invalidateAllOverflowCache(pBt);

  67152.   assert(pBt->autoVacuum);

  67153.   if( !pBt->incrVacuum ){

  67154.     Pgno nFin;         /* Number of pages in database after autovacuuming */

  67155.     Pgno nFree;        /* Number of pages on the freelist initially */

  67156.     Pgno iFree;        /* The next page to be freed */

  67157.     Pgno nOrig;        /* Database size before freeing */

  67158. 

  67159.     nOrig = btreePagecount(pBt);

  67160.     if( PTRMAP_ISPAGE(pBt, nOrig) || nOrig==PENDING_BYTE_PAGE(pBt) ){

  67161.       /* It is not possible to create a database for which the final page

  67162.       ** is either a pointer-map page or the pending-byte page. If one

  67163.       ** is encountered, this indicates corruption.

  67164.       */

  67165.       return SQLITE_CORRUPT_BKPT;

  67166.     }

  67167. 

  67168.     nFree = get4byte(&pBt->pPage1->aData[36]);

  67169.     nFin = finalDbSize(pBt, nOrig, nFree);

  67170.     if( nFin>nOrig ) return SQLITE_CORRUPT_BKPT;

  67171.     if( nFin<nOrig ){

  67172.       rc = saveAllCursors(pBt, 0, 0);

  67173.     }

  67174.     for(iFree=nOrig; iFree>nFin && rc==SQLITE_OK; iFree--){

  67175.       rc = incrVacuumStep(pBt, nFin, iFree, 1);

  67176.     }

  67177.     if( (rc==SQLITE_DONE || rc==SQLITE_OK) && nFree>0 ){

  67178.       rc = sqlite3PagerWrite(pBt->pPage1->pDbPage);

  67179.       put4byte(&pBt->pPage1->aData[32], 0);

  67180.       put4byte(&pBt->pPage1->aData[36], 0);

  67181.       put4byte(&pBt->pPage1->aData[28], nFin);

  67182.       pBt->bDoTruncate = 1;

  67183.       pBt->nPage = nFin;

  67184.     }

  67185.     if( rc!=SQLITE_OK ){

  67186.       sqlite3PagerRollback(pPager);

  67187.     }

  67188.   }

  67189. 

  67190.   assert( nRef>=sqlite3PagerRefcount(pPager) );

  67191.   return rc;

  67192. }

  67193. 

  67194. #else /* ifndef SQLITE_OMIT_AUTOVACUUM */

  67195. # define setChildPtrmaps(x) SQLITE_OK

  67196. #endif

  67197. 

  67198. /*

  67199. ** This routine does the first phase of a two-phase commit.  This routine

  67200. ** causes a rollback journal to be created (if it does not already exist)

  67201. ** and populated with enough information so that if a power loss occurs

  67202. ** the database can be restored to its original state by playing back

  67203. ** the journal.  Then the contents of the journal are flushed out to

  67204. ** the disk.  After the journal is safely on oxide, the changes to the

  67205. ** database are written into the database file and flushed to oxide.

  67206. ** At the end of this call, the rollback journal still exists on the

  67207. ** disk and we are still holding all locks, so the transaction has not

  67208. ** committed.  See sqlite3BtreeCommitPhaseTwo() for the second phase of the

  67209. ** commit process.

  67210. **

  67211. ** This call is a no-op if no write-transaction is currently active on pBt.

  67212. **

  67213. ** Otherwise, sync the database file for the btree pBt. zMaster points to

  67214. ** the name of a master journal file that should be written into the

  67215. ** individual journal file, or is NULL, indicating no master journal file 

  67216. ** (single database transaction).

  67217. **

  67218. ** When this is called, the master journal should already have been

  67219. ** created, populated with this journal pointer and synced to disk.

  67220. **

  67221. ** Once this is routine has returned, the only thing required to commit

  67222. ** the write-transaction for this database file is to delete the journal.

  67223. */

  67224. SQLITE_PRIVATE int sqlite3BtreeCommitPhaseOne(Btree *p, const char *zMaster){

  67225.   int rc = SQLITE_OK;

  67226.   if( p->inTrans==TRANS_WRITE ){

  67227.     BtShared *pBt = p->pBt;

  67228.     sqlite3BtreeEnter(p);

  67229. #ifndef SQLITE_OMIT_AUTOVACUUM

  67230.     if( pBt->autoVacuum ){

  67231.       rc = autoVacuumCommit(pBt);

  67232.       if( rc!=SQLITE_OK ){

  67233.         sqlite3BtreeLeave(p);

  67234.         return rc;

  67235.       }

  67236.     }

  67237.     if( pBt->bDoTruncate ){

  67238.       sqlite3PagerTruncateImage(pBt->pPager, pBt->nPage);

  67239.     }

  67240. #endif

  67241.     rc = sqlite3PagerCommitPhaseOne(pBt->pPager, zMaster, 0);

  67242.     sqlite3BtreeLeave(p);

  67243.   }

  67244.   return rc;

  67245. }

  67246. 

  67247. /*

  67248. ** This function is called from both BtreeCommitPhaseTwo() and BtreeRollback()

  67249. ** at the conclusion of a transaction.

  67250. */

  67251. static void btreeEndTransaction(Btree *p){

  67252.   BtShared *pBt = p->pBt;

  67253.   sqlite3 *db = p->db;

  67254.   assert( sqlite3BtreeHoldsMutex(p) );

  67255. 

  67256. #ifndef SQLITE_OMIT_AUTOVACUUM

  67257.   pBt->bDoTruncate = 0;

  67258. #endif

  67259.   if( p->inTrans>TRANS_NONE && db->nVdbeRead>1 ){

  67260.     /* If there are other active statements that belong to this database

  67261.     ** handle, downgrade to a read-only transaction. The other statements

  67262.     ** may still be reading from the database.  */

  67263.     downgradeAllSharedCacheTableLocks(p);

  67264.     p->inTrans = TRANS_READ;

  67265.   }else{

  67266.     /* If the handle had any kind of transaction open, decrement the 

  67267.     ** transaction count of the shared btree. If the transaction count 

  67268.     ** reaches 0, set the shared state to TRANS_NONE. The unlockBtreeIfUnused()

  67269.     ** call below will unlock the pager.  */

  67270.     if( p->inTrans!=TRANS_NONE ){

  67271.       clearAllSharedCacheTableLocks(p);

  67272.       pBt->nTransaction--;

  67273.       if( 0==pBt->nTransaction ){

  67274.         pBt->inTransaction = TRANS_NONE;

  67275.       }

  67276.     }

  67277. 

  67278.     /* Set the current transaction state to TRANS_NONE and unlock the 

  67279.     ** pager if this call closed the only read or write transaction.  */

  67280.     p->inTrans = TRANS_NONE;

  67281.     unlockBtreeIfUnused(pBt);

  67282.   }

  67283. 

  67284.   btreeIntegrity(p);

  67285. }

  67286. 

  67287. /*

  67288. ** Commit the transaction currently in progress.

  67289. **

  67290. ** This routine implements the second phase of a 2-phase commit.  The

  67291. ** sqlite3BtreeCommitPhaseOne() routine does the first phase and should

  67292. ** be invoked prior to calling this routine.  The sqlite3BtreeCommitPhaseOne()

  67293. ** routine did all the work of writing information out to disk and flushing the

  67294. ** contents so that they are written onto the disk platter.  All this

  67295. ** routine has to do is delete or truncate or zero the header in the

  67296. ** the rollback journal (which causes the transaction to commit) and

  67297. ** drop locks.

  67298. **

  67299. ** Normally, if an error occurs while the pager layer is attempting to 

  67300. ** finalize the underlying journal file, this function returns an error and

  67301. ** the upper layer will attempt a rollback. However, if the second argument

  67302. ** is non-zero then this b-tree transaction is part of a multi-file 

  67303. ** transaction. In this case, the transaction has already been committed 

  67304. ** (by deleting a master journal file) and the caller will ignore this 

  67305. ** functions return code. So, even if an error occurs in the pager layer,

  67306. ** reset the b-tree objects internal state to indicate that the write

  67307. ** transaction has been closed. This is quite safe, as the pager will have

  67308. ** transitioned to the error state.

  67309. **

  67310. ** This will release the write lock on the database file.  If there

  67311. ** are no active cursors, it also releases the read lock.

  67312. */

  67313. SQLITE_PRIVATE int sqlite3BtreeCommitPhaseTwo(Btree *p, int bCleanup){

  67314. 

  67315.   if( p->inTrans==TRANS_NONE ) return SQLITE_OK;

  67316.   sqlite3BtreeEnter(p);

  67317.   btreeIntegrity(p);

  67318. 

  67319.   /* If the handle has a write-transaction open, commit the shared-btrees 

  67320.   ** transaction and set the shared state to TRANS_READ.

  67321.   */

  67322.   if( p->inTrans==TRANS_WRITE ){

  67323.     int rc;

  67324.     BtShared *pBt = p->pBt;

  67325.     assert( pBt->inTransaction==TRANS_WRITE );

  67326.     assert( pBt->nTransaction>0 );

  67327.     rc = sqlite3PagerCommitPhaseTwo(pBt->pPager);

  67328.     if( rc!=SQLITE_OK && bCleanup==0 ){

  67329.       sqlite3BtreeLeave(p);

  67330.       return rc;

  67331.     }

  67332.     p->iDataVersion--;  /* Compensate for pPager->iDataVersion++; */

  67333.     pBt->inTransaction = TRANS_READ;

  67334.     btreeClearHasContent(pBt);

  67335.   }

  67336. 

  67337.   btreeEndTransaction(p);

  67338.   sqlite3BtreeLeave(p);

  67339.   return SQLITE_OK;

  67340. }

  67341. 

  67342. /*

  67343. ** Do both phases of a commit.

  67344. */

  67345. SQLITE_PRIVATE int sqlite3BtreeCommit(Btree *p){

  67346.   int rc;

  67347.   sqlite3BtreeEnter(p);

  67348.   rc = sqlite3BtreeCommitPhaseOne(p, 0);

  67349.   if( rc==SQLITE_OK ){

  67350.     rc = sqlite3BtreeCommitPhaseTwo(p, 0);

  67351.   }

  67352.   sqlite3BtreeLeave(p);

  67353.   return rc;

  67354. }

  67355. 

  67356. /*

  67357. ** This routine sets the state to CURSOR_FAULT and the error

  67358. ** code to errCode for every cursor on any BtShared that pBtree

  67359. ** references.  Or if the writeOnly flag is set to 1, then only

  67360. ** trip write cursors and leave read cursors unchanged.

  67361. **

  67362. ** Every cursor is a candidate to be tripped, including cursors

  67363. ** that belong to other database connections that happen to be

  67364. ** sharing the cache with pBtree.

  67365. **

  67366. ** This routine gets called when a rollback occurs. If the writeOnly

  67367. ** flag is true, then only write-cursors need be tripped - read-only

  67368. ** cursors save their current positions so that they may continue 

  67369. ** following the rollback. Or, if writeOnly is false, all cursors are 

  67370. ** tripped. In general, writeOnly is false if the transaction being

  67371. ** rolled back modified the database schema. In this case b-tree root

  67372. ** pages may be moved or deleted from the database altogether, making

  67373. ** it unsafe for read cursors to continue.

  67374. **

  67375. ** If the writeOnly flag is true and an error is encountered while 

  67376. ** saving the current position of a read-only cursor, all cursors, 

  67377. ** including all read-cursors are tripped.

  67378. **

  67379. ** SQLITE_OK is returned if successful, or if an error occurs while

  67380. ** saving a cursor position, an SQLite error code.

  67381. */

  67382. SQLITE_PRIVATE int sqlite3BtreeTripAllCursors(Btree *pBtree, int errCode, int writeOnly){

  67383.   BtCursor *p;

  67384.   int rc = SQLITE_OK;

  67385. 

  67386.   assert( (writeOnly==0 || writeOnly==1) && BTCF_WriteFlag==1 );

  67387.   if( pBtree ){

  67388.     sqlite3BtreeEnter(pBtree);

  67389.     for(p=pBtree->pBt->pCursor; p; p=p->pNext){

  67390.       if( writeOnly && (p->curFlags & BTCF_WriteFlag)==0 ){

  67391.         if( p->eState==CURSOR_VALID || p->eState==CURSOR_SKIPNEXT ){

  67392.           rc = saveCursorPosition(p);

  67393.           if( rc!=SQLITE_OK ){

  67394.             (void)sqlite3BtreeTripAllCursors(pBtree, rc, 0);

  67395.             break;

  67396.           }

  67397.         }

  67398.       }else{

  67399.         sqlite3BtreeClearCursor(p);

  67400.         p->eState = CURSOR_FAULT;

  67401.         p->skipNext = errCode;

  67402.       }

  67403.       btreeReleaseAllCursorPages(p);

  67404.     }

  67405.     sqlite3BtreeLeave(pBtree);

  67406.   }

  67407.   return rc;

  67408. }

  67409. 

  67410. /*

  67411. ** Set the pBt->nPage field correctly, according to the current

  67412. ** state of the database.  Assume pBt->pPage1 is valid.

  67413. */

  67414. static void btreeSetNPage(BtShared *pBt, MemPage *pPage1){

  67415.   int nPage = get4byte(&pPage1->aData[28]);

  67416.   testcase( nPage==0 );

  67417.   if( nPage==0 ) sqlite3PagerPagecount(pBt->pPager, &nPage);

  67418.   testcase( pBt->nPage!=nPage );

  67419.   pBt->nPage = nPage;

  67420. }

  67421. 

  67422. /*

  67423. ** Rollback the transaction in progress.

  67424. **

  67425. ** If tripCode is not SQLITE_OK then cursors will be invalidated (tripped).

  67426. ** Only write cursors are tripped if writeOnly is true but all cursors are

  67427. ** tripped if writeOnly is false.  Any attempt to use

  67428. ** a tripped cursor will result in an error.

  67429. **

  67430. ** This will release the write lock on the database file.  If there

  67431. ** are no active cursors, it also releases the read lock.

  67432. */

  67433. SQLITE_PRIVATE int sqlite3BtreeRollback(Btree *p, int tripCode, int writeOnly){

  67434.   int rc;

  67435.   BtShared *pBt = p->pBt;

  67436.   MemPage *pPage1;

  67437. 

  67438.   assert( writeOnly==1 || writeOnly==0 );

  67439.   assert( tripCode==SQLITE_ABORT_ROLLBACK || tripCode==SQLITE_OK );

  67440.   sqlite3BtreeEnter(p);

  67441.   if( tripCode==SQLITE_OK ){

  67442.     rc = tripCode = saveAllCursors(pBt, 0, 0);

  67443.     if( rc ) writeOnly = 0;

  67444.   }else{

  67445.     rc = SQLITE_OK;

  67446.   }

  67447.   if( tripCode ){

  67448.     int rc2 = sqlite3BtreeTripAllCursors(p, tripCode, writeOnly);

  67449.     assert( rc==SQLITE_OK || (writeOnly==0 && rc2==SQLITE_OK) );

  67450.     if( rc2!=SQLITE_OK ) rc = rc2;

  67451.   }

  67452.   btreeIntegrity(p);

  67453. 

  67454.   if( p->inTrans==TRANS_WRITE ){

  67455.     int rc2;

  67456. 

  67457.     assert( TRANS_WRITE==pBt->inTransaction );

  67458.     rc2 = sqlite3PagerRollback(pBt->pPager);

  67459.     if( rc2!=SQLITE_OK ){

  67460.       rc = rc2;

  67461.     }

  67462. 

  67463.     /* The rollback may have destroyed the pPage1->aData value.  So

  67464.     ** call btreeGetPage() on page 1 again to make

  67465.     ** sure pPage1->aData is set correctly. */

  67466.     if( btreeGetPage(pBt, 1, &pPage1, 0)==SQLITE_OK ){

  67467.       btreeSetNPage(pBt, pPage1);

  67468.       releasePageOne(pPage1);

  67469.     }

  67470.     assert( countValidCursors(pBt, 1)==0 );

  67471.     pBt->inTransaction = TRANS_READ;

  67472.     btreeClearHasContent(pBt);

  67473.   }

  67474. 

  67475.   btreeEndTransaction(p);

  67476.   sqlite3BtreeLeave(p);

  67477.   return rc;

  67478. }

  67479. 

  67480. /*

  67481. ** Start a statement subtransaction. The subtransaction can be rolled

  67482. ** back independently of the main transaction. You must start a transaction 

  67483. ** before starting a subtransaction. The subtransaction is ended automatically 

  67484. ** if the main transaction commits or rolls back.

  67485. **

  67486. ** Statement subtransactions are used around individual SQL statements

  67487. ** that are contained within a BEGIN...COMMIT block.  If a constraint

  67488. ** error occurs within the statement, the effect of that one statement

  67489. ** can be rolled back without having to rollback the entire transaction.

  67490. **

  67491. ** A statement sub-transaction is implemented as an anonymous savepoint. The

  67492. ** value passed as the second parameter is the total number of savepoints,

  67493. ** including the new anonymous savepoint, open on the B-Tree. i.e. if there

  67494. ** are no active savepoints and no other statement-transactions open,

  67495. ** iStatement is 1. This anonymous savepoint can be released or rolled back

  67496. ** using the sqlite3BtreeSavepoint() function.

  67497. */

  67498. SQLITE_PRIVATE int sqlite3BtreeBeginStmt(Btree *p, int iStatement){

  67499.   int rc;

  67500.   BtShared *pBt = p->pBt;

  67501.   sqlite3BtreeEnter(p);

  67502.   assert( p->inTrans==TRANS_WRITE );

  67503.   assert( (pBt->btsFlags & BTS_READ_ONLY)==0 );

  67504.   assert( iStatement>0 );

  67505.   assert( iStatement>p->db->nSavepoint );

  67506.   assert( pBt->inTransaction==TRANS_WRITE );

  67507.   /* At the pager level, a statement transaction is a savepoint with

  67508.   ** an index greater than all savepoints created explicitly using

  67509.   ** SQL statements. It is illegal to open, release or rollback any

  67510.   ** such savepoints while the statement transaction savepoint is active.

  67511.   */

  67512.   rc = sqlite3PagerOpenSavepoint(pBt->pPager, iStatement);

  67513.   sqlite3BtreeLeave(p);

  67514.   return rc;

  67515. }

  67516. 

  67517. /*

  67518. ** The second argument to this function, op, is always SAVEPOINT_ROLLBACK

  67519. ** or SAVEPOINT_RELEASE. This function either releases or rolls back the

  67520. ** savepoint identified by parameter iSavepoint, depending on the value 

  67521. ** of op.

  67522. **

  67523. ** Normally, iSavepoint is greater than or equal to zero. However, if op is

  67524. ** SAVEPOINT_ROLLBACK, then iSavepoint may also be -1. In this case the 

  67525. ** contents of the entire transaction are rolled back. This is different

  67526. ** from a normal transaction rollback, as no locks are released and the

  67527. ** transaction remains open.

  67528. */

  67529. SQLITE_PRIVATE int sqlite3BtreeSavepoint(Btree *p, int op, int iSavepoint){

  67530.   int rc = SQLITE_OK;

  67531.   if( p && p->inTrans==TRANS_WRITE ){

  67532.     BtShared *pBt = p->pBt;

  67533.     assert( op==SAVEPOINT_RELEASE || op==SAVEPOINT_ROLLBACK );

  67534.     assert( iSavepoint>=0 || (iSavepoint==-1 && op==SAVEPOINT_ROLLBACK) );

  67535.     sqlite3BtreeEnter(p);

  67536.     if( op==SAVEPOINT_ROLLBACK ){

  67537.       rc = saveAllCursors(pBt, 0, 0);

  67538.     }

  67539.     if( rc==SQLITE_OK ){

  67540.       rc = sqlite3PagerSavepoint(pBt->pPager, op, iSavepoint);

  67541.     }

  67542.     if( rc==SQLITE_OK ){

  67543.       if( iSavepoint<0 && (pBt->btsFlags & BTS_INITIALLY_EMPTY)!=0 ){

  67544.         pBt->nPage = 0;

  67545.       }

  67546.       rc = newDatabase(pBt);

  67547.       btreeSetNPage(pBt, pBt->pPage1);

  67548. 

  67549.       /* pBt->nPage might be zero if the database was corrupt when 

  67550.       ** the transaction was started. Otherwise, it must be at least 1.  */

  67551.       assert( CORRUPT_DB || pBt->nPage>0 );

  67552.     }

  67553.     sqlite3BtreeLeave(p);

  67554.   }

  67555.   return rc;

  67556. }

  67557. 

  67558. /*

  67559. ** Create a new cursor for the BTree whose root is on the page

  67560. ** iTable. If a read-only cursor is requested, it is assumed that

  67561. ** the caller already has at least a read-only transaction open

  67562. ** on the database already. If a write-cursor is requested, then

  67563. ** the caller is assumed to have an open write transaction.

  67564. **

  67565. ** If the BTREE_WRCSR bit of wrFlag is clear, then the cursor can only

  67566. ** be used for reading.  If the BTREE_WRCSR bit is set, then the cursor

  67567. ** can be used for reading or for writing if other conditions for writing

  67568. ** are also met.  These are the conditions that must be met in order

  67569. ** for writing to be allowed:

  67570. **

  67571. ** 1:  The cursor must have been opened with wrFlag containing BTREE_WRCSR

  67572. **

  67573. ** 2:  Other database connections that share the same pager cache

  67574. **     but which are not in the READ_UNCOMMITTED state may not have

  67575. **     cursors open with wrFlag==0 on the same table.  Otherwise

  67576. **     the changes made by this write cursor would be visible to

  67577. **     the read cursors in the other database connection.

  67578. **

  67579. ** 3:  The database must be writable (not on read-only media)

  67580. **

  67581. ** 4:  There must be an active transaction.

  67582. **

  67583. ** The BTREE_FORDELETE bit of wrFlag may optionally be set if BTREE_WRCSR

  67584. ** is set.  If FORDELETE is set, that is a hint to the implementation that

  67585. ** this cursor will only be used to seek to and delete entries of an index

  67586. ** as part of a larger DELETE statement.  The FORDELETE hint is not used by

  67587. ** this implementation.  But in a hypothetical alternative storage engine 

  67588. ** in which index entries are automatically deleted when corresponding table

  67589. ** rows are deleted, the FORDELETE flag is a hint that all SEEK and DELETE

  67590. ** operations on this cursor can be no-ops and all READ operations can 

  67591. ** return a null row (2-bytes: 0x01 0x00).

  67592. **

  67593. ** No checking is done to make sure that page iTable really is the

  67594. ** root page of a b-tree.  If it is not, then the cursor acquired

  67595. ** will not work correctly.

  67596. **

  67597. ** It is assumed that the sqlite3BtreeCursorZero() has been called

  67598. ** on pCur to initialize the memory space prior to invoking this routine.

  67599. */

  67600. static int btreeCursor(

  67601.   Btree *p,                              /* The btree */

  67602.   int iTable,                            /* Root page of table to open */

  67603.   int wrFlag,                            /* 1 to write. 0 read-only */

  67604.   struct KeyInfo *pKeyInfo,              /* First arg to comparison function */

  67605.   BtCursor *pCur                         /* Space for new cursor */

  67606. ){

  67607.   BtShared *pBt = p->pBt;                /* Shared b-tree handle */

  67608.   BtCursor *pX;                          /* Looping over other all cursors */

  67609. 

  67610.   assert( sqlite3BtreeHoldsMutex(p) );

  67611.   assert( wrFlag==0 

  67612.        || wrFlag==BTREE_WRCSR 

  67613.        || wrFlag==(BTREE_WRCSR|BTREE_FORDELETE) 

  67614.   );

  67615. 

  67616.   /* The following assert statements verify that if this is a sharable 

  67617.   ** b-tree database, the connection is holding the required table locks, 

  67618.   ** and that no other connection has any open cursor that conflicts with 

  67619.   ** this lock.  */

  67620.   assert( hasSharedCacheTableLock(p, iTable, pKeyInfo!=0, (wrFlag?2:1)) );

  67621.   assert( wrFlag==0 || !hasReadConflicts(p, iTable) );

  67622. 

  67623.   /* Assert that the caller has opened the required transaction. */

  67624.   assert( p->inTrans>TRANS_NONE );

  67625.   assert( wrFlag==0 || p->inTrans==TRANS_WRITE );

  67626.   assert( pBt->pPage1 && pBt->pPage1->aData );

  67627.   assert( wrFlag==0 || (pBt->btsFlags & BTS_READ_ONLY)==0 );

  67628. 

  67629.   if( wrFlag ){

  67630.     allocateTempSpace(pBt);

  67631.     if( pBt->pTmpSpace==0 ) return SQLITE_NOMEM_BKPT;

  67632.   }

  67633.   if( iTable==1 && btreePagecount(pBt)==0 ){

  67634.     assert( wrFlag==0 );

  67635.     iTable = 0;

  67636.   }

  67637. 

  67638.   /* Now that no other errors can occur, finish filling in the BtCursor

  67639.   ** variables and link the cursor into the BtShared list.  */

  67640.   pCur->pgnoRoot = (Pgno)iTable;

  67641.   pCur->iPage = -1;

  67642.   pCur->pKeyInfo = pKeyInfo;

  67643.   pCur->pBtree = p;

  67644.   pCur->pBt = pBt;

  67645.   pCur->curFlags = wrFlag ? BTCF_WriteFlag : 0;

  67646.   pCur->curPagerFlags = wrFlag ? 0 : PAGER_GET_READONLY;

  67647.   /* If there are two or more cursors on the same btree, then all such

  67648.   ** cursors *must* have the BTCF_Multiple flag set. */

  67649.   for(pX=pBt->pCursor; pX; pX=pX->pNext){

  67650.     if( pX->pgnoRoot==(Pgno)iTable ){

  67651.       pX->curFlags |= BTCF_Multiple;

  67652.       pCur->curFlags |= BTCF_Multiple;

  67653.     }

  67654.   }

  67655.   pCur->pNext = pBt->pCursor;

  67656.   pBt->pCursor = pCur;

  67657.   pCur->eState = CURSOR_INVALID;

  67658.   return SQLITE_OK;

  67659. }

  67660. SQLITE_PRIVATE int sqlite3BtreeCursor(

  67661.   Btree *p,                                   /* The btree */

  67662.   int iTable,                                 /* Root page of table to open */

  67663.   int wrFlag,                                 /* 1 to write. 0 read-only */

  67664.   struct KeyInfo *pKeyInfo,                   /* First arg to xCompare() */

  67665.   BtCursor *pCur                              /* Write new cursor here */

  67666. ){

  67667.   int rc;

  67668.   if( iTable<1 ){

  67669.     rc = SQLITE_CORRUPT_BKPT;

  67670.   }else{

  67671.     sqlite3BtreeEnter(p);

  67672.     rc = btreeCursor(p, iTable, wrFlag, pKeyInfo, pCur);

  67673.     sqlite3BtreeLeave(p);

  67674.   }

  67675.   return rc;

  67676. }

  67677. 

  67678. /*

  67679. ** Return the size of a BtCursor object in bytes.

  67680. **

  67681. ** This interfaces is needed so that users of cursors can preallocate

  67682. ** sufficient storage to hold a cursor.  The BtCursor object is opaque

  67683. ** to users so they cannot do the sizeof() themselves - they must call

  67684. ** this routine.

  67685. */

  67686. SQLITE_PRIVATE int sqlite3BtreeCursorSize(void){

  67687.   return ROUND8(sizeof(BtCursor));

  67688. }

  67689. 

  67690. /*

  67691. ** Initialize memory that will be converted into a BtCursor object.

  67692. **

  67693. ** The simple approach here would be to memset() the entire object

  67694. ** to zero.  But it turns out that the apPage[] and aiIdx[] arrays

  67695. ** do not need to be zeroed and they are large, so we can save a lot

  67696. ** of run-time by skipping the initialization of those elements.

  67697. */

  67698. SQLITE_PRIVATE void sqlite3BtreeCursorZero(BtCursor *p){

  67699.   memset(p, 0, offsetof(BtCursor, BTCURSOR_FIRST_UNINIT));

  67700. }

  67701. 

  67702. /*

  67703. ** Close a cursor.  The read lock on the database file is released

  67704. ** when the last cursor is closed.

  67705. */

  67706. SQLITE_PRIVATE int sqlite3BtreeCloseCursor(BtCursor *pCur){

  67707.   Btree *pBtree = pCur->pBtree;

  67708.   if( pBtree ){

  67709.     BtShared *pBt = pCur->pBt;

  67710.     sqlite3BtreeEnter(pBtree);

  67711.     assert( pBt->pCursor!=0 );

  67712.     if( pBt->pCursor==pCur ){

  67713.       pBt->pCursor = pCur->pNext;

  67714.     }else{

  67715.       BtCursor *pPrev = pBt->pCursor;

  67716.       do{

  67717.         if( pPrev->pNext==pCur ){

  67718.           pPrev->pNext = pCur->pNext;

  67719.           break;

  67720.         }

  67721.         pPrev = pPrev->pNext;

  67722.       }while( ALWAYS(pPrev) );

  67723.     }

  67724.     btreeReleaseAllCursorPages(pCur);

  67725.     unlockBtreeIfUnused(pBt);

  67726.     sqlite3_free(pCur->aOverflow);

  67727.     sqlite3_free(pCur->pKey);

  67728.     sqlite3BtreeLeave(pBtree);

  67729.     pCur->pBtree = 0;

  67730.   }

  67731.   return SQLITE_OK;

  67732. }

  67733. 

  67734. /*

  67735. ** Make sure the BtCursor* given in the argument has a valid

  67736. ** BtCursor.info structure.  If it is not already valid, call

  67737. ** btreeParseCell() to fill it in.

  67738. **

  67739. ** BtCursor.info is a cache of the information in the current cell.

  67740. ** Using this cache reduces the number of calls to btreeParseCell().

  67741. */

  67742. #ifndef NDEBUG

  67743.   static int cellInfoEqual(CellInfo *a, CellInfo *b){

  67744.     if( a->nKey!=b->nKey ) return 0;

  67745.     if( a->pPayload!=b->pPayload ) return 0;

  67746.     if( a->nPayload!=b->nPayload ) return 0;

  67747.     if( a->nLocal!=b->nLocal ) return 0;

  67748.     if( a->nSize!=b->nSize ) return 0;

  67749.     return 1;

  67750.   }

  67751.   static void assertCellInfo(BtCursor *pCur){

  67752.     CellInfo info;

  67753.     memset(&info, 0, sizeof(info));

  67754.     btreeParseCell(pCur->pPage, pCur->ix, &info);

  67755.     assert( CORRUPT_DB || cellInfoEqual(&info, &pCur->info) );

  67756.   }

  67757. #else

  67758.   #define assertCellInfo(x)

  67759. #endif

  67760. static SQLITE_NOINLINE void getCellInfo(BtCursor *pCur){

  67761.   if( pCur->info.nSize==0 ){

  67762.     pCur->curFlags |= BTCF_ValidNKey;

  67763.     btreeParseCell(pCur->pPage,pCur->ix,&pCur->info);

  67764.   }else{

  67765.     assertCellInfo(pCur);

  67766.   }

  67767. }

  67768. 

  67769. #ifndef NDEBUG  /* The next routine used only within assert() statements */

  67770. /*

  67771. ** Return true if the given BtCursor is valid.  A valid cursor is one

  67772. ** that is currently pointing to a row in a (non-empty) table.

  67773. ** This is a verification routine is used only within assert() statements.

  67774. */

  67775. SQLITE_PRIVATE int sqlite3BtreeCursorIsValid(BtCursor *pCur){

  67776.   return pCur && pCur->eState==CURSOR_VALID;

  67777. }

  67778. #endif /* NDEBUG */

  67779. SQLITE_PRIVATE int sqlite3BtreeCursorIsValidNN(BtCursor *pCur){

  67780.   assert( pCur!=0 );

  67781.   return pCur->eState==CURSOR_VALID;

  67782. }

  67783. 

  67784. /*

  67785. ** Return the value of the integer key or "rowid" for a table btree.

  67786. ** This routine is only valid for a cursor that is pointing into a

  67787. ** ordinary table btree.  If the cursor points to an index btree or

  67788. ** is invalid, the result of this routine is undefined.

  67789. */

  67790. SQLITE_PRIVATE i64 sqlite3BtreeIntegerKey(BtCursor *pCur){

  67791.   assert( cursorHoldsMutex(pCur) );

  67792.   assert( pCur->eState==CURSOR_VALID );

  67793.   assert( pCur->curIntKey );

  67794.   getCellInfo(pCur);

  67795.   return pCur->info.nKey;

  67796. }

  67797. 

  67798. #ifdef SQLITE_ENABLE_OFFSET_SQL_FUNC

  67799. /*

  67800. ** Return the offset into the database file for the start of the

  67801. ** payload to which the cursor is pointing.

  67802. */

  67803. SQLITE_PRIVATE i64 sqlite3BtreeOffset(BtCursor *pCur){

  67804.   assert( cursorHoldsMutex(pCur) );

  67805.   assert( pCur->eState==CURSOR_VALID );

  67806.   getCellInfo(pCur);

  67807.   return (i64)pCur->pBt->pageSize*((i64)pCur->pPage->pgno - 1) +

  67808.          (i64)(pCur->info.pPayload - pCur->pPage->aData);

  67809. }

  67810. #endif /* SQLITE_ENABLE_OFFSET_SQL_FUNC */

  67811. 

  67812. /*

  67813. ** Return the number of bytes of payload for the entry that pCur is

  67814. ** currently pointing to.  For table btrees, this will be the amount

  67815. ** of data.  For index btrees, this will be the size of the key.

  67816. **

  67817. ** The caller must guarantee that the cursor is pointing to a non-NULL

  67818. ** valid entry.  In other words, the calling procedure must guarantee

  67819. ** that the cursor has Cursor.eState==CURSOR_VALID.

  67820. */

  67821. SQLITE_PRIVATE u32 sqlite3BtreePayloadSize(BtCursor *pCur){

  67822.   assert( cursorHoldsMutex(pCur) );

  67823.   assert( pCur->eState==CURSOR_VALID );

  67824.   getCellInfo(pCur);

  67825.   return pCur->info.nPayload;

  67826. }

  67827. 

  67828. /*

  67829. ** Return an upper bound on the size of any record for the table

  67830. ** that the cursor is pointing into.

  67831. **

  67832. ** This is an optimization.  Everything will still work if this

  67833. ** routine always returns 2147483647 (which is the largest record

  67834. ** that SQLite can handle) or more.  But returning a smaller value might

  67835. ** prevent large memory allocations when trying to interpret a

  67836. ** corrupt datrabase.

  67837. **

  67838. ** The current implementation merely returns the size of the underlying

  67839. ** database file.

  67840. */

  67841. SQLITE_PRIVATE sqlite3_int64 sqlite3BtreeMaxRecordSize(BtCursor *pCur){

  67842.   assert( cursorHoldsMutex(pCur) );

  67843.   assert( pCur->eState==CURSOR_VALID );

  67844.   return pCur->pBt->pageSize * (sqlite3_int64)pCur->pBt->nPage;

  67845. }

  67846. 

  67847. /*

  67848. ** Given the page number of an overflow page in the database (parameter

  67849. ** ovfl), this function finds the page number of the next page in the 

  67850. ** linked list of overflow pages. If possible, it uses the auto-vacuum

  67851. ** pointer-map data instead of reading the content of page ovfl to do so. 

  67852. **

  67853. ** If an error occurs an SQLite error code is returned. Otherwise:

  67854. **

  67855. ** The page number of the next overflow page in the linked list is 

  67856. ** written to *pPgnoNext. If page ovfl is the last page in its linked 

  67857. ** list, *pPgnoNext is set to zero. 

  67858. **

  67859. ** If ppPage is not NULL, and a reference to the MemPage object corresponding

  67860. ** to page number pOvfl was obtained, then *ppPage is set to point to that

  67861. ** reference. It is the responsibility of the caller to call releasePage()

  67862. ** on *ppPage to free the reference. In no reference was obtained (because

  67863. ** the pointer-map was used to obtain the value for *pPgnoNext), then

  67864. ** *ppPage is set to zero.

  67865. */

  67866. static int getOverflowPage(

  67867.   BtShared *pBt,               /* The database file */

  67868.   Pgno ovfl,                   /* Current overflow page number */

  67869.   MemPage **ppPage,            /* OUT: MemPage handle (may be NULL) */

  67870.   Pgno *pPgnoNext              /* OUT: Next overflow page number */

  67871. ){

  67872.   Pgno next = 0;

  67873.   MemPage *pPage = 0;

  67874.   int rc = SQLITE_OK;

  67875. 

  67876.   assert( sqlite3_mutex_held(pBt->mutex) );

  67877.   assert(pPgnoNext);

  67878. 

  67879. #ifndef SQLITE_OMIT_AUTOVACUUM

  67880.   /* Try to find the next page in the overflow list using the

  67881.   ** autovacuum pointer-map pages. Guess that the next page in 

  67882.   ** the overflow list is page number (ovfl+1). If that guess turns 

  67883.   ** out to be wrong, fall back to loading the data of page 

  67884.   ** number ovfl to determine the next page number.

  67885.   */

  67886.   if( pBt->autoVacuum ){

  67887.     Pgno pgno;

  67888.     Pgno iGuess = ovfl+1;

  67889.     u8 eType;

  67890. 

  67891.     while( PTRMAP_ISPAGE(pBt, iGuess) || iGuess==PENDING_BYTE_PAGE(pBt) ){

  67892.       iGuess++;

  67893.     }

  67894. 

  67895.     if( iGuess<=btreePagecount(pBt) ){

  67896.       rc = ptrmapGet(pBt, iGuess, &eType, &pgno);

  67897.       if( rc==SQLITE_OK && eType==PTRMAP_OVERFLOW2 && pgno==ovfl ){

  67898.         next = iGuess;

  67899.         rc = SQLITE_DONE;

  67900.       }

  67901.     }

  67902.   }

  67903. #endif

  67904. 

  67905.   assert( next==0 || rc==SQLITE_DONE );

  67906.   if( rc==SQLITE_OK ){

  67907.     rc = btreeGetPage(pBt, ovfl, &pPage, (ppPage==0) ? PAGER_GET_READONLY : 0);

  67908.     assert( rc==SQLITE_OK || pPage==0 );

  67909.     if( rc==SQLITE_OK ){

  67910.       next = get4byte(pPage->aData);

  67911.     }

  67912.   }

  67913. 

  67914.   *pPgnoNext = next;

  67915.   if( ppPage ){

  67916.     *ppPage = pPage;

  67917.   }else{

  67918.     releasePage(pPage);

  67919.   }

  67920.   return (rc==SQLITE_DONE ? SQLITE_OK : rc);

  67921. }

  67922. 

  67923. /*

  67924. ** Copy data from a buffer to a page, or from a page to a buffer.

  67925. **

  67926. ** pPayload is a pointer to data stored on database page pDbPage.

  67927. ** If argument eOp is false, then nByte bytes of data are copied

  67928. ** from pPayload to the buffer pointed at by pBuf. If eOp is true,

  67929. ** then sqlite3PagerWrite() is called on pDbPage and nByte bytes

  67930. ** of data are copied from the buffer pBuf to pPayload.

  67931. **

  67932. ** SQLITE_OK is returned on success, otherwise an error code.

  67933. */

  67934. static int copyPayload(

  67935.   void *pPayload,           /* Pointer to page data */

  67936.   void *pBuf,               /* Pointer to buffer */

  67937.   int nByte,                /* Number of bytes to copy */

  67938.   int eOp,                  /* 0 -> copy from page, 1 -> copy to page */

  67939.   DbPage *pDbPage           /* Page containing pPayload */

  67940. ){

  67941.   if( eOp ){

  67942.     /* Copy data from buffer to page (a write operation) */

  67943.     int rc = sqlite3PagerWrite(pDbPage);

  67944.     if( rc!=SQLITE_OK ){

  67945.       return rc;

  67946.     }

  67947.     memcpy(pPayload, pBuf, nByte);

  67948.   }else{

  67949.     /* Copy data from page to buffer (a read operation) */

  67950.     memcpy(pBuf, pPayload, nByte);

  67951.   }

  67952.   return SQLITE_OK;

  67953. }

  67954. 

  67955. /*

  67956. ** This function is used to read or overwrite payload information

  67957. ** for the entry that the pCur cursor is pointing to. The eOp

  67958. ** argument is interpreted as follows:

  67959. **

  67960. **   0: The operation is a read. Populate the overflow cache.

  67961. **   1: The operation is a write. Populate the overflow cache.

  67962. **

  67963. ** A total of "amt" bytes are read or written beginning at "offset".

  67964. ** Data is read to or from the buffer pBuf.

  67965. **

  67966. ** The content being read or written might appear on the main page

  67967. ** or be scattered out on multiple overflow pages.

  67968. **

  67969. ** If the current cursor entry uses one or more overflow pages

  67970. ** this function may allocate space for and lazily populate

  67971. ** the overflow page-list cache array (BtCursor.aOverflow). 

  67972. ** Subsequent calls use this cache to make seeking to the supplied offset 

  67973. ** more efficient.

  67974. **

  67975. ** Once an overflow page-list cache has been allocated, it must be

  67976. ** invalidated if some other cursor writes to the same table, or if

  67977. ** the cursor is moved to a different row. Additionally, in auto-vacuum

  67978. ** mode, the following events may invalidate an overflow page-list cache.

  67979. **

  67980. **   * An incremental vacuum,

  67981. **   * A commit in auto_vacuum="full" mode,

  67982. **   * Creating a table (may require moving an overflow page).

  67983. */

  67984. static int accessPayload(

  67985.   BtCursor *pCur,      /* Cursor pointing to entry to read from */

  67986.   u32 offset,          /* Begin reading this far into payload */

  67987.   u32 amt,             /* Read this many bytes */

  67988.   unsigned char *pBuf, /* Write the bytes into this buffer */ 

  67989.   int eOp              /* zero to read. non-zero to write. */

  67990. ){

  67991.   unsigned char *aPayload;

  67992.   int rc = SQLITE_OK;

  67993.   int iIdx = 0;

  67994.   MemPage *pPage = pCur->pPage;               /* Btree page of current entry */

  67995.   BtShared *pBt = pCur->pBt;                  /* Btree this cursor belongs to */

  67996. #ifdef SQLITE_DIRECT_OVERFLOW_READ

  67997.   unsigned char * const pBufStart = pBuf;     /* Start of original out buffer */

  67998. #endif

  67999. 

  68000.   assert( pPage );

  68001.   assert( eOp==0 || eOp==1 );

  68002.   assert( pCur->eState==CURSOR_VALID );

  68003.   assert( pCur->ix<pPage->nCell );

  68004.   assert( cursorHoldsMutex(pCur) );

  68005. 

  68006.   getCellInfo(pCur);

  68007.   aPayload = pCur->info.pPayload;

  68008.   assert( offset+amt <= pCur->info.nPayload );

  68009. 

  68010.   assert( aPayload > pPage->aData );

  68011.   if( (uptr)(aPayload - pPage->aData) > (pBt->usableSize - pCur->info.nLocal) ){

  68012.     /* Trying to read or write past the end of the data is an error.  The

  68013.     ** conditional above is really:

  68014.     **    &aPayload[pCur->info.nLocal] > &pPage->aData[pBt->usableSize]

  68015.     ** but is recast into its current form to avoid integer overflow problems

  68016.     */

  68017.     return SQLITE_CORRUPT_PAGE(pPage);

  68018.   }

  68019. 

  68020.   /* Check if data must be read/written to/from the btree page itself. */

  68021.   if( offset<pCur->info.nLocal ){

  68022.     int a = amt;

  68023.     if( a+offset>pCur->info.nLocal ){

  68024.       a = pCur->info.nLocal - offset;

  68025.     }

  68026.     rc = copyPayload(&aPayload[offset], pBuf, a, eOp, pPage->pDbPage);

  68027.     offset = 0;

  68028.     pBuf += a;

  68029.     amt -= a;

  68030.   }else{

  68031.     offset -= pCur->info.nLocal;

  68032.   }

  68033. 

  68034. 

  68035.   if( rc==SQLITE_OK && amt>0 ){

  68036.     const u32 ovflSize = pBt->usableSize - 4;  /* Bytes content per ovfl page */

  68037.     Pgno nextPage;

  68038. 

  68039.     nextPage = get4byte(&aPayload[pCur->info.nLocal]);

  68040. 

  68041.     /* If the BtCursor.aOverflow[] has not been allocated, allocate it now.

  68042.     **

  68043.     ** The aOverflow[] array is sized at one entry for each overflow page

  68044.     ** in the overflow chain. The page number of the first overflow page is

  68045.     ** stored in aOverflow[0], etc. A value of 0 in the aOverflow[] array

  68046.     ** means "not yet known" (the cache is lazily populated).

  68047.     */

  68048.     if( (pCur->curFlags & BTCF_ValidOvfl)==0 ){

  68049.       int nOvfl = (pCur->info.nPayload-pCur->info.nLocal+ovflSize-1)/ovflSize;

  68050.       if( pCur->aOverflow==0

  68051.        || nOvfl*(int)sizeof(Pgno) > sqlite3MallocSize(pCur->aOverflow)

  68052.       ){

  68053.         Pgno *aNew = (Pgno*)sqlite3Realloc(

  68054.             pCur->aOverflow, nOvfl*2*sizeof(Pgno)

  68055.         );

  68056.         if( aNew==0 ){

  68057.           return SQLITE_NOMEM_BKPT;

  68058.         }else{

  68059.           pCur->aOverflow = aNew;

  68060.         }

  68061.       }

  68062.       memset(pCur->aOverflow, 0, nOvfl*sizeof(Pgno));

  68063.       pCur->curFlags |= BTCF_ValidOvfl;

  68064.     }else{

  68065.       /* If the overflow page-list cache has been allocated and the

  68066.       ** entry for the first required overflow page is valid, skip

  68067.       ** directly to it.

  68068.       */

  68069.       if( pCur->aOverflow[offset/ovflSize] ){

  68070.         iIdx = (offset/ovflSize);

  68071.         nextPage = pCur->aOverflow[iIdx];

  68072.         offset = (offset%ovflSize);

  68073.       }

  68074.     }

  68075. 

  68076.     assert( rc==SQLITE_OK && amt>0 );

  68077.     while( nextPage ){

  68078.       /* If required, populate the overflow page-list cache. */

  68079.       assert( pCur->aOverflow[iIdx]==0

  68080.               || pCur->aOverflow[iIdx]==nextPage

  68081.               || CORRUPT_DB );

  68082.       pCur->aOverflow[iIdx] = nextPage;

  68083. 

  68084.       if( offset>=ovflSize ){

  68085.         /* The only reason to read this page is to obtain the page

  68086.         ** number for the next page in the overflow chain. The page

  68087.         ** data is not required. So first try to lookup the overflow

  68088.         ** page-list cache, if any, then fall back to the getOverflowPage()

  68089.         ** function.

  68090.         */

  68091.         assert( pCur->curFlags & BTCF_ValidOvfl );

  68092.         assert( pCur->pBtree->db==pBt->db );

  68093.         if( pCur->aOverflow[iIdx+1] ){

  68094.           nextPage = pCur->aOverflow[iIdx+1];

  68095.         }else{

  68096.           rc = getOverflowPage(pBt, nextPage, 0, &nextPage);

  68097.         }

  68098.         offset -= ovflSize;

  68099.       }else{

  68100.         /* Need to read this page properly. It contains some of the

  68101.         ** range of data that is being read (eOp==0) or written (eOp!=0).

  68102.         */

  68103.         int a = amt;

  68104.         if( a + offset > ovflSize ){

  68105.           a = ovflSize - offset;

  68106.         }

  68107. 

  68108. #ifdef SQLITE_DIRECT_OVERFLOW_READ

  68109.         /* If all the following are true:

  68110.         **

  68111.         **   1) this is a read operation, and 

  68112.         **   2) data is required from the start of this overflow page, and

  68113.         **   3) there are no dirty pages in the page-cache

  68114.         **   4) the database is file-backed, and

  68115.         **   5) the page is not in the WAL file

  68116.         **   6) at least 4 bytes have already been read into the output buffer 

  68117.         **

  68118.         ** then data can be read directly from the database file into the

  68119.         ** output buffer, bypassing the page-cache altogether. This speeds

  68120.         ** up loading large records that span many overflow pages.

  68121.         */

  68122.         if( eOp==0                                             /* (1) */

  68123.          && offset==0                                          /* (2) */

  68124.          && sqlite3PagerDirectReadOk(pBt->pPager, nextPage)    /* (3,4,5) */

  68125.          && &pBuf[-4]>=pBufStart                               /* (6) */

  68126.         ){

  68127.           sqlite3_file *fd = sqlite3PagerFile(pBt->pPager);

  68128.           u8 aSave[4];

  68129.           u8 *aWrite = &pBuf[-4];

  68130.           assert( aWrite>=pBufStart );                         /* due to (6) */

  68131.           memcpy(aSave, aWrite, 4);

  68132.           rc = sqlite3OsRead(fd, aWrite, a+4, (i64)pBt->pageSize*(nextPage-1));

  68133.           nextPage = get4byte(aWrite);

  68134.           memcpy(aWrite, aSave, 4);

  68135.         }else

  68136. #endif

  68137. 

  68138.         {

  68139.           DbPage *pDbPage;

  68140.           rc = sqlite3PagerGet(pBt->pPager, nextPage, &pDbPage,

  68141.               (eOp==0 ? PAGER_GET_READONLY : 0)

  68142.           );

  68143.           if( rc==SQLITE_OK ){

  68144.             aPayload = sqlite3PagerGetData(pDbPage);

  68145.             nextPage = get4byte(aPayload);

  68146.             rc = copyPayload(&aPayload[offset+4], pBuf, a, eOp, pDbPage);

  68147.             sqlite3PagerUnref(pDbPage);

  68148.             offset = 0;

  68149.           }

  68150.         }

  68151.         amt -= a;

  68152.         if( amt==0 ) return rc;

  68153.         pBuf += a;

  68154.       }

  68155.       if( rc ) break;

  68156.       iIdx++;

  68157.     }

  68158.   }

  68159. 

  68160.   if( rc==SQLITE_OK && amt>0 ){

  68161.     /* Overflow chain ends prematurely */

  68162.     return SQLITE_CORRUPT_PAGE(pPage);

  68163.   }

  68164.   return rc;

  68165. }

  68166. 

  68167. /*

  68168. ** Read part of the payload for the row at which that cursor pCur is currently

  68169. ** pointing.  "amt" bytes will be transferred into pBuf[].  The transfer

  68170. ** begins at "offset".

  68171. **

  68172. ** pCur can be pointing to either a table or an index b-tree.

  68173. ** If pointing to a table btree, then the content section is read.  If

  68174. ** pCur is pointing to an index b-tree then the key section is read.

  68175. **

  68176. ** For sqlite3BtreePayload(), the caller must ensure that pCur is pointing

  68177. ** to a valid row in the table.  For sqlite3BtreePayloadChecked(), the

  68178. ** cursor might be invalid or might need to be restored before being read.

  68179. **

  68180. ** Return SQLITE_OK on success or an error code if anything goes

  68181. ** wrong.  An error is returned if "offset+amt" is larger than

  68182. ** the available payload.

  68183. */

  68184. SQLITE_PRIVATE int sqlite3BtreePayload(BtCursor *pCur, u32 offset, u32 amt, void *pBuf){

  68185.   assert( cursorHoldsMutex(pCur) );

  68186.   assert( pCur->eState==CURSOR_VALID );

  68187.   assert( pCur->iPage>=0 && pCur->pPage );

  68188.   assert( pCur->ix<pCur->pPage->nCell );

  68189.   return accessPayload(pCur, offset, amt, (unsigned char*)pBuf, 0);

  68190. }

  68191. 

  68192. /*

  68193. ** This variant of sqlite3BtreePayload() works even if the cursor has not

  68194. ** in the CURSOR_VALID state.  It is only used by the sqlite3_blob_read()

  68195. ** interface.

  68196. */

  68197. #ifndef SQLITE_OMIT_INCRBLOB

  68198. static SQLITE_NOINLINE int accessPayloadChecked(

  68199.   BtCursor *pCur,

  68200.   u32 offset,

  68201.   u32 amt,

  68202.   void *pBuf

  68203. ){

  68204.   int rc;

  68205.   if ( pCur->eState==CURSOR_INVALID ){

  68206.     return SQLITE_ABORT;

  68207.   }

  68208.   assert( cursorOwnsBtShared(pCur) );

  68209.   rc = btreeRestoreCursorPosition(pCur);

  68210.   return rc ? rc : accessPayload(pCur, offset, amt, pBuf, 0);

  68211. }

  68212. SQLITE_PRIVATE int sqlite3BtreePayloadChecked(BtCursor *pCur, u32 offset, u32 amt, void *pBuf){

  68213.   if( pCur->eState==CURSOR_VALID ){

  68214.     assert( cursorOwnsBtShared(pCur) );

  68215.     return accessPayload(pCur, offset, amt, pBuf, 0);

  68216.   }else{

  68217.     return accessPayloadChecked(pCur, offset, amt, pBuf);

  68218.   }

  68219. }

  68220. #endif /* SQLITE_OMIT_INCRBLOB */

  68221. 

  68222. /*

  68223. ** Return a pointer to payload information from the entry that the 

  68224. ** pCur cursor is pointing to.  The pointer is to the beginning of

  68225. ** the key if index btrees (pPage->intKey==0) and is the data for

  68226. ** table btrees (pPage->intKey==1). The number of bytes of available

  68227. ** key/data is written into *pAmt.  If *pAmt==0, then the value

  68228. ** returned will not be a valid pointer.

  68229. **

  68230. ** This routine is an optimization.  It is common for the entire key

  68231. ** and data to fit on the local page and for there to be no overflow

  68232. ** pages.  When that is so, this routine can be used to access the

  68233. ** key and data without making a copy.  If the key and/or data spills

  68234. ** onto overflow pages, then accessPayload() must be used to reassemble

  68235. ** the key/data and copy it into a preallocated buffer.

  68236. **

  68237. ** The pointer returned by this routine looks directly into the cached

  68238. ** page of the database.  The data might change or move the next time

  68239. ** any btree routine is called.

  68240. */

  68241. static const void *fetchPayload(

  68242.   BtCursor *pCur,      /* Cursor pointing to entry to read from */

  68243.   u32 *pAmt            /* Write the number of available bytes here */

  68244. ){

  68245.   int amt;

  68246.   assert( pCur!=0 && pCur->iPage>=0 && pCur->pPage);

  68247.   assert( pCur->eState==CURSOR_VALID );

  68248.   assert( sqlite3_mutex_held(pCur->pBtree->db->mutex) );

  68249.   assert( cursorOwnsBtShared(pCur) );

  68250.   assert( pCur->ix<pCur->pPage->nCell );

  68251.   assert( pCur->info.nSize>0 );

  68252.   assert( pCur->info.pPayload>pCur->pPage->aData || CORRUPT_DB );

  68253.   assert( pCur->info.pPayload<pCur->pPage->aDataEnd ||CORRUPT_DB);

  68254.   amt = pCur->info.nLocal;

  68255.   if( amt>(int)(pCur->pPage->aDataEnd - pCur->info.pPayload) ){

  68256.     /* There is too little space on the page for the expected amount

  68257.     ** of local content. Database must be corrupt. */

  68258.     assert( CORRUPT_DB );

  68259.     amt = MAX(0, (int)(pCur->pPage->aDataEnd - pCur->info.pPayload));

  68260.   }

  68261.   *pAmt = (u32)amt;

  68262.   return (void*)pCur->info.pPayload;

  68263. }

  68264. 

  68265. 

  68266. /*

  68267. ** For the entry that cursor pCur is point to, return as

  68268. ** many bytes of the key or data as are available on the local

  68269. ** b-tree page.  Write the number of available bytes into *pAmt.

  68270. **

  68271. ** The pointer returned is ephemeral.  The key/data may move

  68272. ** or be destroyed on the next call to any Btree routine,

  68273. ** including calls from other threads against the same cache.

  68274. ** Hence, a mutex on the BtShared should be held prior to calling

  68275. ** this routine.

  68276. **

  68277. ** These routines is used to get quick access to key and data

  68278. ** in the common case where no overflow pages are used.

  68279. */

  68280. SQLITE_PRIVATE const void *sqlite3BtreePayloadFetch(BtCursor *pCur, u32 *pAmt){

  68281.   return fetchPayload(pCur, pAmt);

  68282. }

  68283. 

  68284. 

  68285. /*

  68286. ** Move the cursor down to a new child page.  The newPgno argument is the

  68287. ** page number of the child page to move to.

  68288. **

  68289. ** This function returns SQLITE_CORRUPT if the page-header flags field of

  68290. ** the new child page does not match the flags field of the parent (i.e.

  68291. ** if an intkey page appears to be the parent of a non-intkey page, or

  68292. ** vice-versa).

  68293. */

  68294. static int moveToChild(BtCursor *pCur, u32 newPgno){

  68295.   BtShared *pBt = pCur->pBt;

  68296. 

  68297.   assert( cursorOwnsBtShared(pCur) );

  68298.   assert( pCur->eState==CURSOR_VALID );

  68299.   assert( pCur->iPage<BTCURSOR_MAX_DEPTH );

  68300.   assert( pCur->iPage>=0 );

  68301.   if( pCur->iPage>=(BTCURSOR_MAX_DEPTH-1) ){

  68302.     return SQLITE_CORRUPT_BKPT;

  68303.   }

  68304.   pCur->info.nSize = 0;

  68305.   pCur->curFlags &= ~(BTCF_ValidNKey|BTCF_ValidOvfl);

  68306.   pCur->aiIdx[pCur->iPage] = pCur->ix;

  68307.   pCur->apPage[pCur->iPage] = pCur->pPage;

  68308.   pCur->ix = 0;

  68309.   pCur->iPage++;

  68310.   return getAndInitPage(pBt, newPgno, &pCur->pPage, pCur, pCur->curPagerFlags);

  68311. }

  68312. 

  68313. #ifdef SQLITE_DEBUG

  68314. /*

  68315. ** Page pParent is an internal (non-leaf) tree page. This function 

  68316. ** asserts that page number iChild is the left-child if the iIdx'th

  68317. ** cell in page pParent. Or, if iIdx is equal to the total number of

  68318. ** cells in pParent, that page number iChild is the right-child of

  68319. ** the page.

  68320. */

  68321. static void assertParentIndex(MemPage *pParent, int iIdx, Pgno iChild){

  68322.   if( CORRUPT_DB ) return;  /* The conditions tested below might not be true

  68323.                             ** in a corrupt database */

  68324.   assert( iIdx<=pParent->nCell );

  68325.   if( iIdx==pParent->nCell ){

  68326.     assert( get4byte(&pParent->aData[pParent->hdrOffset+8])==iChild );

  68327.   }else{

  68328.     assert( get4byte(findCell(pParent, iIdx))==iChild );

  68329.   }

  68330. }

  68331. #else

  68332. #  define assertParentIndex(x,y,z) 

  68333. #endif

  68334. 

  68335. /*

  68336. ** Move the cursor up to the parent page.

  68337. **

  68338. ** pCur->idx is set to the cell index that contains the pointer

  68339. ** to the page we are coming from.  If we are coming from the

  68340. ** right-most child page then pCur->idx is set to one more than

  68341. ** the largest cell index.

  68342. */

  68343. static void moveToParent(BtCursor *pCur){

  68344.   MemPage *pLeaf;

  68345.   assert( cursorOwnsBtShared(pCur) );

  68346.   assert( pCur->eState==CURSOR_VALID );

  68347.   assert( pCur->iPage>0 );

  68348.   assert( pCur->pPage );

  68349.   assertParentIndex(

  68350.     pCur->apPage[pCur->iPage-1], 

  68351.     pCur->aiIdx[pCur->iPage-1], 

  68352.     pCur->pPage->pgno

  68353.   );

  68354.   testcase( pCur->aiIdx[pCur->iPage-1] > pCur->apPage[pCur->iPage-1]->nCell );

  68355.   pCur->info.nSize = 0;

  68356.   pCur->curFlags &= ~(BTCF_ValidNKey|BTCF_ValidOvfl);

  68357.   pCur->ix = pCur->aiIdx[pCur->iPage-1];

  68358.   pLeaf = pCur->pPage;

  68359.   pCur->pPage = pCur->apPage[--pCur->iPage];

  68360.   releasePageNotNull(pLeaf);

  68361. }

  68362. 

  68363. /*

  68364. ** Move the cursor to point to the root page of its b-tree structure.

  68365. **

  68366. ** If the table has a virtual root page, then the cursor is moved to point

  68367. ** to the virtual root page instead of the actual root page. A table has a

  68368. ** virtual root page when the actual root page contains no cells and a 

  68369. ** single child page. This can only happen with the table rooted at page 1.

  68370. **

  68371. ** If the b-tree structure is empty, the cursor state is set to 

  68372. ** CURSOR_INVALID and this routine returns SQLITE_EMPTY. Otherwise,

  68373. ** the cursor is set to point to the first cell located on the root

  68374. ** (or virtual root) page and the cursor state is set to CURSOR_VALID.

  68375. **

  68376. ** If this function returns successfully, it may be assumed that the

  68377. ** page-header flags indicate that the [virtual] root-page is the expected 

  68378. ** kind of b-tree page (i.e. if when opening the cursor the caller did not

  68379. ** specify a KeyInfo structure the flags byte is set to 0x05 or 0x0D,

  68380. ** indicating a table b-tree, or if the caller did specify a KeyInfo 

  68381. ** structure the flags byte is set to 0x02 or 0x0A, indicating an index

  68382. ** b-tree).

  68383. */

  68384. static int moveToRoot(BtCursor *pCur){

  68385.   MemPage *pRoot;

  68386.   int rc = SQLITE_OK;

  68387. 

  68388.   assert( cursorOwnsBtShared(pCur) );

  68389.   assert( CURSOR_INVALID < CURSOR_REQUIRESEEK );

  68390.   assert( CURSOR_VALID   < CURSOR_REQUIRESEEK );

  68391.   assert( CURSOR_FAULT   > CURSOR_REQUIRESEEK );

  68392.   assert( pCur->eState < CURSOR_REQUIRESEEK || pCur->iPage<0 );

  68393.   assert( pCur->pgnoRoot>0 || pCur->iPage<0 );

  68394. 

  68395.   if( pCur->iPage>=0 ){

  68396.     if( pCur->iPage ){

  68397.       releasePageNotNull(pCur->pPage);

  68398.       while( --pCur->iPage ){

  68399.         releasePageNotNull(pCur->apPage[pCur->iPage]);

  68400.       }

  68401.       pCur->pPage = pCur->apPage[0];

  68402.       goto skip_init;

  68403.     }

  68404.   }else if( pCur->pgnoRoot==0 ){

  68405.     pCur->eState = CURSOR_INVALID;

  68406.     return SQLITE_EMPTY;

  68407.   }else{

  68408.     assert( pCur->iPage==(-1) );

  68409.     if( pCur->eState>=CURSOR_REQUIRESEEK ){

  68410.       if( pCur->eState==CURSOR_FAULT ){

  68411.         assert( pCur->skipNext!=SQLITE_OK );

  68412.         return pCur->skipNext;

  68413.       }

  68414.       sqlite3BtreeClearCursor(pCur);

  68415.     }

  68416.     rc = getAndInitPage(pCur->pBtree->pBt, pCur->pgnoRoot, &pCur->pPage,

  68417.                         0, pCur->curPagerFlags);

  68418.     if( rc!=SQLITE_OK ){

  68419.       pCur->eState = CURSOR_INVALID;

  68420.       return rc;

  68421.     }

  68422.     pCur->iPage = 0;

  68423.     pCur->curIntKey = pCur->pPage->intKey;

  68424.   }

  68425.   pRoot = pCur->pPage;

  68426.   assert( pRoot->pgno==pCur->pgnoRoot );

  68427. 

  68428.   /* If pCur->pKeyInfo is not NULL, then the caller that opened this cursor

  68429.   ** expected to open it on an index b-tree. Otherwise, if pKeyInfo is

  68430.   ** NULL, the caller expects a table b-tree. If this is not the case,

  68431.   ** return an SQLITE_CORRUPT error. 

  68432.   **

  68433.   ** Earlier versions of SQLite assumed that this test could not fail

  68434.   ** if the root page was already loaded when this function was called (i.e.

  68435.   ** if pCur->iPage>=0). But this is not so if the database is corrupted 

  68436.   ** in such a way that page pRoot is linked into a second b-tree table 

  68437.   ** (or the freelist).  */

  68438.   assert( pRoot->intKey==1 || pRoot->intKey==0 );

  68439.   if( pRoot->isInit==0 || (pCur->pKeyInfo==0)!=pRoot->intKey ){

  68440.     return SQLITE_CORRUPT_PAGE(pCur->pPage);

  68441.   }

  68442. 

  68443. skip_init:  

  68444.   pCur->ix = 0;

  68445.   pCur->info.nSize = 0;

  68446.   pCur->curFlags &= ~(BTCF_AtLast|BTCF_ValidNKey|BTCF_ValidOvfl);

  68447. 

  68448.   pRoot = pCur->pPage;

  68449.   if( pRoot->nCell>0 ){

  68450.     pCur->eState = CURSOR_VALID;

  68451.   }else if( !pRoot->leaf ){

  68452.     Pgno subpage;

  68453.     if( pRoot->pgno!=1 ) return SQLITE_CORRUPT_BKPT;

  68454.     subpage = get4byte(&pRoot->aData[pRoot->hdrOffset+8]);

  68455.     pCur->eState = CURSOR_VALID;

  68456.     rc = moveToChild(pCur, subpage);

  68457.   }else{

  68458.     pCur->eState = CURSOR_INVALID;

  68459.     rc = SQLITE_EMPTY;

  68460.   }

  68461.   return rc;

  68462. }

  68463. 

  68464. /*

  68465. ** Move the cursor down to the left-most leaf entry beneath the

  68466. ** entry to which it is currently pointing.

  68467. **

  68468. ** The left-most leaf is the one with the smallest key - the first

  68469. ** in ascending order.

  68470. */

  68471. static int moveToLeftmost(BtCursor *pCur){

  68472.   Pgno pgno;

  68473.   int rc = SQLITE_OK;

  68474.   MemPage *pPage;

  68475. 

  68476.   assert( cursorOwnsBtShared(pCur) );

  68477.   assert( pCur->eState==CURSOR_VALID );

  68478.   while( rc==SQLITE_OK && !(pPage = pCur->pPage)->leaf ){

  68479.     assert( pCur->ix<pPage->nCell );

  68480.     pgno = get4byte(findCell(pPage, pCur->ix));

  68481.     rc = moveToChild(pCur, pgno);

  68482.   }

  68483.   return rc;

  68484. }

  68485. 

  68486. /*

  68487. ** Move the cursor down to the right-most leaf entry beneath the

  68488. ** page to which it is currently pointing.  Notice the difference

  68489. ** between moveToLeftmost() and moveToRightmost().  moveToLeftmost()

  68490. ** finds the left-most entry beneath the *entry* whereas moveToRightmost()

  68491. ** finds the right-most entry beneath the *page*.

  68492. **

  68493. ** The right-most entry is the one with the largest key - the last

  68494. ** key in ascending order.

  68495. */

  68496. static int moveToRightmost(BtCursor *pCur){

  68497.   Pgno pgno;

  68498.   int rc = SQLITE_OK;

  68499.   MemPage *pPage = 0;

  68500. 

  68501.   assert( cursorOwnsBtShared(pCur) );

  68502.   assert( pCur->eState==CURSOR_VALID );

  68503.   while( !(pPage = pCur->pPage)->leaf ){

  68504.     pgno = get4byte(&pPage->aData[pPage->hdrOffset+8]);

  68505.     pCur->ix = pPage->nCell;

  68506.     rc = moveToChild(pCur, pgno);

  68507.     if( rc ) return rc;

  68508.   }

  68509.   pCur->ix = pPage->nCell-1;

  68510.   assert( pCur->info.nSize==0 );

  68511.   assert( (pCur->curFlags & BTCF_ValidNKey)==0 );

  68512.   return SQLITE_OK;

  68513. }

  68514. 

  68515. /* Move the cursor to the first entry in the table.  Return SQLITE_OK

  68516. ** on success.  Set *pRes to 0 if the cursor actually points to something

  68517. ** or set *pRes to 1 if the table is empty.

  68518. */

  68519. SQLITE_PRIVATE int sqlite3BtreeFirst(BtCursor *pCur, int *pRes){

  68520.   int rc;

  68521. 

  68522.   assert( cursorOwnsBtShared(pCur) );

  68523.   assert( sqlite3_mutex_held(pCur->pBtree->db->mutex) );

  68524.   rc = moveToRoot(pCur);

  68525.   if( rc==SQLITE_OK ){

  68526.     assert( pCur->pPage->nCell>0 );

  68527.     *pRes = 0;

  68528.     rc = moveToLeftmost(pCur);

  68529.   }else if( rc==SQLITE_EMPTY ){

  68530.     assert( pCur->pgnoRoot==0 || pCur->pPage->nCell==0 );

  68531.     *pRes = 1;

  68532.     rc = SQLITE_OK;

  68533.   }

  68534.   return rc;

  68535. }

  68536. 

  68537. /* Move the cursor to the last entry in the table.  Return SQLITE_OK

  68538. ** on success.  Set *pRes to 0 if the cursor actually points to something

  68539. ** or set *pRes to 1 if the table is empty.

  68540. */

  68541. SQLITE_PRIVATE int sqlite3BtreeLast(BtCursor *pCur, int *pRes){

  68542.   int rc;

  68543.  

  68544.   assert( cursorOwnsBtShared(pCur) );

  68545.   assert( sqlite3_mutex_held(pCur->pBtree->db->mutex) );

  68546. 

  68547.   /* If the cursor already points to the last entry, this is a no-op. */

  68548.   if( CURSOR_VALID==pCur->eState && (pCur->curFlags & BTCF_AtLast)!=0 ){

  68549. #ifdef SQLITE_DEBUG

  68550.     /* This block serves to assert() that the cursor really does point 

  68551.     ** to the last entry in the b-tree. */

  68552.     int ii;

  68553.     for(ii=0; ii<pCur->iPage; ii++){

  68554.       assert( pCur->aiIdx[ii]==pCur->apPage[ii]->nCell );

  68555.     }

  68556.     assert( pCur->ix==pCur->pPage->nCell-1 );

  68557.     assert( pCur->pPage->leaf );

  68558. #endif

  68559.     *pRes = 0;

  68560.     return SQLITE_OK;

  68561.   }

  68562. 

  68563.   rc = moveToRoot(pCur);

  68564.   if( rc==SQLITE_OK ){

  68565.     assert( pCur->eState==CURSOR_VALID );

  68566.     *pRes = 0;

  68567.     rc = moveToRightmost(pCur);

  68568.     if( rc==SQLITE_OK ){

  68569.       pCur->curFlags |= BTCF_AtLast;

  68570.     }else{

  68571.       pCur->curFlags &= ~BTCF_AtLast;

  68572.     }

  68573.   }else if( rc==SQLITE_EMPTY ){

  68574.     assert( pCur->pgnoRoot==0 || pCur->pPage->nCell==0 );

  68575.     *pRes = 1;

  68576.     rc = SQLITE_OK;

  68577.   }

  68578.   return rc;

  68579. }

  68580. 

  68581. /* Move the cursor so that it points to an entry near the key 

  68582. ** specified by pIdxKey or intKey.   Return a success code.

  68583. **

  68584. ** For INTKEY tables, the intKey parameter is used.  pIdxKey 

  68585. ** must be NULL.  For index tables, pIdxKey is used and intKey

  68586. ** is ignored.

  68587. **

  68588. ** If an exact match is not found, then the cursor is always

  68589. ** left pointing at a leaf page which would hold the entry if it

  68590. ** were present.  The cursor might point to an entry that comes

  68591. ** before or after the key.

  68592. **

  68593. ** An integer is written into *pRes which is the result of

  68594. ** comparing the key with the entry to which the cursor is 

  68595. ** pointing.  The meaning of the integer written into

  68596. ** *pRes is as follows:

  68597. **

  68598. **     *pRes<0      The cursor is left pointing at an entry that

  68599. **                  is smaller than intKey/pIdxKey or if the table is empty

  68600. **                  and the cursor is therefore left point to nothing.

  68601. **

  68602. **     *pRes==0     The cursor is left pointing at an entry that

  68603. **                  exactly matches intKey/pIdxKey.

  68604. **

  68605. **     *pRes>0      The cursor is left pointing at an entry that

  68606. **                  is larger than intKey/pIdxKey.

  68607. **

  68608. ** For index tables, the pIdxKey->eqSeen field is set to 1 if there

  68609. ** exists an entry in the table that exactly matches pIdxKey.  

  68610. */

  68611. SQLITE_PRIVATE int sqlite3BtreeMovetoUnpacked(

  68612.   BtCursor *pCur,          /* The cursor to be moved */

  68613.   UnpackedRecord *pIdxKey, /* Unpacked index key */

  68614.   i64 intKey,              /* The table key */

  68615.   int biasRight,           /* If true, bias the search to the high end */

  68616.   int *pRes                /* Write search results here */

  68617. ){

  68618.   int rc;

  68619.   RecordCompare xRecordCompare;

  68620. 

  68621.   assert( cursorOwnsBtShared(pCur) );

  68622.   assert( sqlite3_mutex_held(pCur->pBtree->db->mutex) );

  68623.   assert( pRes );

  68624.   assert( (pIdxKey==0)==(pCur->pKeyInfo==0) );

  68625.   assert( pCur->eState!=CURSOR_VALID || (pIdxKey==0)==(pCur->curIntKey!=0) );

  68626. 

  68627.   /* If the cursor is already positioned at the point we are trying

  68628.   ** to move to, then just return without doing any work */

  68629.   if( pIdxKey==0

  68630.    && pCur->eState==CURSOR_VALID && (pCur->curFlags & BTCF_ValidNKey)!=0

  68631.   ){

  68632.     if( pCur->info.nKey==intKey ){

  68633.       *pRes = 0;

  68634.       return SQLITE_OK;

  68635.     }

  68636.     if( pCur->info.nKey<intKey ){

  68637.       if( (pCur->curFlags & BTCF_AtLast)!=0 ){

  68638.         *pRes = -1;

  68639.         return SQLITE_OK;

  68640.       }

  68641.       /* If the requested key is one more than the previous key, then

  68642.       ** try to get there using sqlite3BtreeNext() rather than a full

  68643.       ** binary search.  This is an optimization only.  The correct answer

  68644.       ** is still obtained without this case, only a little more slowely */

  68645.       if( pCur->info.nKey+1==intKey ){

  68646.         *pRes = 0;

  68647.         rc = sqlite3BtreeNext(pCur, 0);

  68648.         if( rc==SQLITE_OK ){

  68649.           getCellInfo(pCur);

  68650.           if( pCur->info.nKey==intKey ){

  68651.             return SQLITE_OK;

  68652.           }

  68653.         }else if( rc==SQLITE_DONE ){

  68654.           rc = SQLITE_OK;

  68655.         }else{

  68656.           return rc;

  68657.         }

  68658.       }

  68659.     }

  68660.   }

  68661. 

  68662.   if( pIdxKey ){

  68663.     xRecordCompare = sqlite3VdbeFindCompare(pIdxKey);

  68664.     pIdxKey->errCode = 0;

  68665.     assert( pIdxKey->default_rc==1 

  68666.          || pIdxKey->default_rc==0 

  68667.          || pIdxKey->default_rc==-1

  68668.     );

  68669.   }else{

  68670.     xRecordCompare = 0; /* All keys are integers */

  68671.   }

  68672. 

  68673.   rc = moveToRoot(pCur);

  68674.   if( rc ){

  68675.     if( rc==SQLITE_EMPTY ){

  68676.       assert( pCur->pgnoRoot==0 || pCur->pPage->nCell==0 );

  68677.       *pRes = -1;

  68678.       return SQLITE_OK;

  68679.     }

  68680.     return rc;

  68681.   }

  68682.   assert( pCur->pPage );

  68683.   assert( pCur->pPage->isInit );

  68684.   assert( pCur->eState==CURSOR_VALID );

  68685.   assert( pCur->pPage->nCell > 0 );

  68686.   assert( pCur->iPage==0 || pCur->apPage[0]->intKey==pCur->curIntKey );

  68687.   assert( pCur->curIntKey || pIdxKey );

  68688.   for(;;){

  68689.     int lwr, upr, idx, c;

  68690.     Pgno chldPg;

  68691.     MemPage *pPage = pCur->pPage;

  68692.     u8 *pCell;                          /* Pointer to current cell in pPage */

  68693. 

  68694.     /* pPage->nCell must be greater than zero. If this is the root-page

  68695.     ** the cursor would have been INVALID above and this for(;;) loop

  68696.     ** not run. If this is not the root-page, then the moveToChild() routine

  68697.     ** would have already detected db corruption. Similarly, pPage must

  68698.     ** be the right kind (index or table) of b-tree page. Otherwise

  68699.     ** a moveToChild() or moveToRoot() call would have detected corruption.  */

  68700.     assert( pPage->nCell>0 );

  68701.     assert( pPage->intKey==(pIdxKey==0) );

  68702.     lwr = 0;

  68703.     upr = pPage->nCell-1;

  68704.     assert( biasRight==0 || biasRight==1 );

  68705.     idx = upr>>(1-biasRight); /* idx = biasRight ? upr : (lwr+upr)/2; */

  68706.     pCur->ix = (u16)idx;

  68707.     if( xRecordCompare==0 ){

  68708.       for(;;){

  68709.         i64 nCellKey;

  68710.         pCell = findCellPastPtr(pPage, idx);

  68711.         if( pPage->intKeyLeaf ){

  68712.           while( 0x80 <= *(pCell++) ){

  68713.             if( pCell>=pPage->aDataEnd ){

  68714.               return SQLITE_CORRUPT_PAGE(pPage);

  68715.             }

  68716.           }

  68717.         }

  68718.         getVarint(pCell, (u64*)&nCellKey);

  68719.         if( nCellKey<intKey ){

  68720.           lwr = idx+1;

  68721.           if( lwr>upr ){ c = -1; break; }

  68722.         }else if( nCellKey>intKey ){

  68723.           upr = idx-1;

  68724.           if( lwr>upr ){ c = +1; break; }

  68725.         }else{

  68726.           assert( nCellKey==intKey );

  68727.           pCur->ix = (u16)idx;

  68728.           if( !pPage->leaf ){

  68729.             lwr = idx;

  68730.             goto moveto_next_layer;

  68731.           }else{

  68732.             pCur->curFlags |= BTCF_ValidNKey;

  68733.             pCur->info.nKey = nCellKey;

  68734.             pCur->info.nSize = 0;

  68735.             *pRes = 0;

  68736.             return SQLITE_OK;

  68737.           }

  68738.         }

  68739.         assert( lwr+upr>=0 );

  68740.         idx = (lwr+upr)>>1;  /* idx = (lwr+upr)/2; */

  68741.       }

  68742.     }else{

  68743.       for(;;){

  68744.         int nCell;  /* Size of the pCell cell in bytes */

  68745.         pCell = findCellPastPtr(pPage, idx);

  68746. 

  68747.         /* The maximum supported page-size is 65536 bytes. This means that

  68748.         ** the maximum number of record bytes stored on an index B-Tree

  68749.         ** page is less than 16384 bytes and may be stored as a 2-byte

  68750.         ** varint. This information is used to attempt to avoid parsing 

  68751.         ** the entire cell by checking for the cases where the record is 

  68752.         ** stored entirely within the b-tree page by inspecting the first 

  68753.         ** 2 bytes of the cell.

  68754.         */

  68755.         nCell = pCell[0];

  68756.         if( nCell<=pPage->max1bytePayload ){

  68757.           /* This branch runs if the record-size field of the cell is a

  68758.           ** single byte varint and the record fits entirely on the main

  68759.           ** b-tree page.  */

  68760.           testcase( pCell+nCell+1==pPage->aDataEnd );

  68761.           c = xRecordCompare(nCell, (void*)&pCell[1], pIdxKey);

  68762.         }else if( !(pCell[1] & 0x80) 

  68763.           && (nCell = ((nCell&0x7f)<<7) + pCell[1])<=pPage->maxLocal

  68764.         ){

  68765.           /* The record-size field is a 2 byte varint and the record 

  68766.           ** fits entirely on the main b-tree page.  */

  68767.           testcase( pCell+nCell+2==pPage->aDataEnd );

  68768.           c = xRecordCompare(nCell, (void*)&pCell[2], pIdxKey);

  68769.         }else{

  68770.           /* The record flows over onto one or more overflow pages. In

  68771.           ** this case the whole cell needs to be parsed, a buffer allocated

  68772.           ** and accessPayload() used to retrieve the record into the

  68773.           ** buffer before VdbeRecordCompare() can be called. 

  68774.           **

  68775.           ** If the record is corrupt, the xRecordCompare routine may read

  68776.           ** up to two varints past the end of the buffer. An extra 18 

  68777.           ** bytes of padding is allocated at the end of the buffer in

  68778.           ** case this happens.  */

  68779.           void *pCellKey;

  68780.           u8 * const pCellBody = pCell - pPage->childPtrSize;

  68781.           const int nOverrun = 18;  /* Size of the overrun padding */

  68782.           pPage->xParseCell(pPage, pCellBody, &pCur->info);

  68783.           nCell = (int)pCur->info.nKey;

  68784.           testcase( nCell<0 );   /* True if key size is 2^32 or more */

  68785.           testcase( nCell==0 );  /* Invalid key size:  0x80 0x80 0x00 */

  68786.           testcase( nCell==1 );  /* Invalid key size:  0x80 0x80 0x01 */

  68787.           testcase( nCell==2 );  /* Minimum legal index key size */

  68788.           if( nCell<2 || nCell/pCur->pBt->usableSize>pCur->pBt->nPage ){

  68789.             rc = SQLITE_CORRUPT_PAGE(pPage);

  68790.             goto moveto_finish;

  68791.           }

  68792.           pCellKey = sqlite3Malloc( nCell+nOverrun );

  68793.           if( pCellKey==0 ){

  68794.             rc = SQLITE_NOMEM_BKPT;

  68795.             goto moveto_finish;

  68796.           }

  68797.           pCur->ix = (u16)idx;

  68798.           rc = accessPayload(pCur, 0, nCell, (unsigned char*)pCellKey, 0);

  68799.           memset(((u8*)pCellKey)+nCell,0,nOverrun); /* Fix uninit warnings */

  68800.           pCur->curFlags &= ~BTCF_ValidOvfl;

  68801.           if( rc ){

  68802.             sqlite3_free(pCellKey);

  68803.             goto moveto_finish;

  68804.           }

  68805.           c = sqlite3VdbeRecordCompare(nCell, pCellKey, pIdxKey);

  68806.           sqlite3_free(pCellKey);

  68807.         }

  68808.         assert( 

  68809.             (pIdxKey->errCode!=SQLITE_CORRUPT || c==0)

  68810.          && (pIdxKey->errCode!=SQLITE_NOMEM || pCur->pBtree->db->mallocFailed)

  68811.         );

  68812.         if( c<0 ){

  68813.           lwr = idx+1;

  68814.         }else if( c>0 ){

  68815.           upr = idx-1;

  68816.         }else{

  68817.           assert( c==0 );

  68818.           *pRes = 0;

  68819.           rc = SQLITE_OK;

  68820.           pCur->ix = (u16)idx;

  68821.           if( pIdxKey->errCode ) rc = SQLITE_CORRUPT_BKPT;

  68822.           goto moveto_finish;

  68823.         }

  68824.         if( lwr>upr ) break;

  68825.         assert( lwr+upr>=0 );

  68826.         idx = (lwr+upr)>>1;  /* idx = (lwr+upr)/2 */

  68827.       }

  68828.     }

  68829.     assert( lwr==upr+1 || (pPage->intKey && !pPage->leaf) );

  68830.     assert( pPage->isInit );

  68831.     if( pPage->leaf ){

  68832.       assert( pCur->ix<pCur->pPage->nCell );

  68833.       pCur->ix = (u16)idx;

  68834.       *pRes = c;

  68835.       rc = SQLITE_OK;

  68836.       goto moveto_finish;

  68837.     }

  68838. moveto_next_layer:

  68839.     if( lwr>=pPage->nCell ){

  68840.       chldPg = get4byte(&pPage->aData[pPage->hdrOffset+8]);

  68841.     }else{

  68842.       chldPg = get4byte(findCell(pPage, lwr));

  68843.     }

  68844.     pCur->ix = (u16)lwr;

  68845.     rc = moveToChild(pCur, chldPg);

  68846.     if( rc ) break;

  68847.   }

  68848. moveto_finish:

  68849.   pCur->info.nSize = 0;

  68850.   assert( (pCur->curFlags & BTCF_ValidOvfl)==0 );

  68851.   return rc;

  68852. }

  68853. 

  68854. 

  68855. /*

  68856. ** Return TRUE if the cursor is not pointing at an entry of the table.

  68857. **

  68858. ** TRUE will be returned after a call to sqlite3BtreeNext() moves

  68859. ** past the last entry in the table or sqlite3BtreePrev() moves past

  68860. ** the first entry.  TRUE is also returned if the table is empty.

  68861. */

  68862. SQLITE_PRIVATE int sqlite3BtreeEof(BtCursor *pCur){

  68863.   /* TODO: What if the cursor is in CURSOR_REQUIRESEEK but all table entries

  68864.   ** have been deleted? This API will need to change to return an error code

  68865.   ** as well as the boolean result value.

  68866.   */

  68867.   return (CURSOR_VALID!=pCur->eState);

  68868. }

  68869. 

  68870. /*

  68871. ** Return an estimate for the number of rows in the table that pCur is

  68872. ** pointing to.  Return a negative number if no estimate is currently 

  68873. ** available.

  68874. */

  68875. SQLITE_PRIVATE i64 sqlite3BtreeRowCountEst(BtCursor *pCur){

  68876.   i64 n;

  68877.   u8 i;

  68878. 

  68879.   assert( cursorOwnsBtShared(pCur) );

  68880.   assert( sqlite3_mutex_held(pCur->pBtree->db->mutex) );

  68881. 

  68882.   /* Currently this interface is only called by the OP_IfSmaller

  68883.   ** opcode, and it that case the cursor will always be valid and

  68884.   ** will always point to a leaf node. */

  68885.   if( NEVER(pCur->eState!=CURSOR_VALID) ) return -1;

  68886.   if( NEVER(pCur->pPage->leaf==0) ) return -1;

  68887. 

  68888.   n = pCur->pPage->nCell;

  68889.   for(i=0; i<pCur->iPage; i++){

  68890.     n *= pCur->apPage[i]->nCell;

  68891.   }

  68892.   return n;

  68893. }

  68894. 

  68895. /*

  68896. ** Advance the cursor to the next entry in the database. 

  68897. ** Return value:

  68898. **

  68899. **    SQLITE_OK        success

  68900. **    SQLITE_DONE      cursor is already pointing at the last element

  68901. **    otherwise        some kind of error occurred

  68902. **

  68903. ** The main entry point is sqlite3BtreeNext().  That routine is optimized

  68904. ** for the common case of merely incrementing the cell counter BtCursor.aiIdx

  68905. ** to the next cell on the current page.  The (slower) btreeNext() helper

  68906. ** routine is called when it is necessary to move to a different page or

  68907. ** to restore the cursor.

  68908. **

  68909. ** If bit 0x01 of the F argument in sqlite3BtreeNext(C,F) is 1, then the

  68910. ** cursor corresponds to an SQL index and this routine could have been

  68911. ** skipped if the SQL index had been a unique index.  The F argument

  68912. ** is a hint to the implement.  SQLite btree implementation does not use

  68913. ** this hint, but COMDB2 does.

  68914. */

  68915. static SQLITE_NOINLINE int btreeNext(BtCursor *pCur){

  68916.   int rc;

  68917.   int idx;

  68918.   MemPage *pPage;

  68919. 

  68920.   assert( cursorOwnsBtShared(pCur) );

  68921.   if( pCur->eState!=CURSOR_VALID ){

  68922.     assert( (pCur->curFlags & BTCF_ValidOvfl)==0 );

  68923.     rc = restoreCursorPosition(pCur);

  68924.     if( rc!=SQLITE_OK ){

  68925.       return rc;

  68926.     }

  68927.     if( CURSOR_INVALID==pCur->eState ){

  68928.       return SQLITE_DONE;

  68929.     }

  68930.     if( pCur->eState==CURSOR_SKIPNEXT ){

  68931.       pCur->eState = CURSOR_VALID;

  68932.       if( pCur->skipNext>0 ) return SQLITE_OK;

  68933.     }

  68934.   }

  68935. 

  68936.   pPage = pCur->pPage;

  68937.   idx = ++pCur->ix;

  68938.   if( !pPage->isInit ){

  68939.     /* The only known way for this to happen is for there to be a

  68940.     ** recursive SQL function that does a DELETE operation as part of a

  68941.     ** SELECT which deletes content out from under an active cursor

  68942.     ** in a corrupt database file where the table being DELETE-ed from

  68943.     ** has pages in common with the table being queried.  See TH3

  68944.     ** module cov1/btree78.test testcase 220 (2018-06-08) for an

  68945.     ** example. */

  68946.     return SQLITE_CORRUPT_BKPT;

  68947.   }

  68948. 

  68949.   /* If the database file is corrupt, it is possible for the value of idx 

  68950.   ** to be invalid here. This can only occur if a second cursor modifies

  68951.   ** the page while cursor pCur is holding a reference to it. Which can

  68952.   ** only happen if the database is corrupt in such a way as to link the

  68953.   ** page into more than one b-tree structure. */

  68954.   testcase( idx>pPage->nCell );

  68955. 

  68956.   if( idx>=pPage->nCell ){

  68957.     if( !pPage->leaf ){

  68958.       rc = moveToChild(pCur, get4byte(&pPage->aData[pPage->hdrOffset+8]));

  68959.       if( rc ) return rc;

  68960.       return moveToLeftmost(pCur);

  68961.     }

  68962.     do{

  68963.       if( pCur->iPage==0 ){

  68964.         pCur->eState = CURSOR_INVALID;

  68965.         return SQLITE_DONE;

  68966.       }

  68967.       moveToParent(pCur);

  68968.       pPage = pCur->pPage;

  68969.     }while( pCur->ix>=pPage->nCell );

  68970.     if( pPage->intKey ){

  68971.       return sqlite3BtreeNext(pCur, 0);

  68972.     }else{

  68973.       return SQLITE_OK;

  68974.     }

  68975.   }

  68976.   if( pPage->leaf ){

  68977.     return SQLITE_OK;

  68978.   }else{

  68979.     return moveToLeftmost(pCur);

  68980.   }

  68981. }

  68982. SQLITE_PRIVATE int sqlite3BtreeNext(BtCursor *pCur, int flags){

  68983.   MemPage *pPage;

  68984.   UNUSED_PARAMETER( flags );  /* Used in COMDB2 but not native SQLite */

  68985.   assert( cursorOwnsBtShared(pCur) );

  68986.   assert( flags==0 || flags==1 );

  68987.   pCur->info.nSize = 0;

  68988.   pCur->curFlags &= ~(BTCF_ValidNKey|BTCF_ValidOvfl);

  68989.   if( pCur->eState!=CURSOR_VALID ) return btreeNext(pCur);

  68990.   pPage = pCur->pPage;

  68991.   if( (++pCur->ix)>=pPage->nCell ){

  68992.     pCur->ix--;

  68993.     return btreeNext(pCur);

  68994.   }

  68995.   if( pPage->leaf ){

  68996.     return SQLITE_OK;

  68997.   }else{

  68998.     return moveToLeftmost(pCur);

  68999.   }

  69000. }

  69001. 

  69002. /*

  69003. ** Step the cursor to the back to the previous entry in the database.

  69004. ** Return values:

  69005. **

  69006. **     SQLITE_OK     success

  69007. **     SQLITE_DONE   the cursor is already on the first element of the table

  69008. **     otherwise     some kind of error occurred

  69009. **

  69010. ** The main entry point is sqlite3BtreePrevious().  That routine is optimized

  69011. ** for the common case of merely decrementing the cell counter BtCursor.aiIdx

  69012. ** to the previous cell on the current page.  The (slower) btreePrevious()

  69013. ** helper routine is called when it is necessary to move to a different page

  69014. ** or to restore the cursor.

  69015. **

  69016. ** If bit 0x01 of the F argument to sqlite3BtreePrevious(C,F) is 1, then

  69017. ** the cursor corresponds to an SQL index and this routine could have been

  69018. ** skipped if the SQL index had been a unique index.  The F argument is a

  69019. ** hint to the implement.  The native SQLite btree implementation does not

  69020. ** use this hint, but COMDB2 does.

  69021. */

  69022. static SQLITE_NOINLINE int btreePrevious(BtCursor *pCur){

  69023.   int rc;

  69024.   MemPage *pPage;

  69025. 

  69026.   assert( cursorOwnsBtShared(pCur) );

  69027.   assert( (pCur->curFlags & (BTCF_AtLast|BTCF_ValidOvfl|BTCF_ValidNKey))==0 );

  69028.   assert( pCur->info.nSize==0 );

  69029.   if( pCur->eState!=CURSOR_VALID ){

  69030.     rc = restoreCursorPosition(pCur);

  69031.     if( rc!=SQLITE_OK ){

  69032.       return rc;

  69033.     }

  69034.     if( CURSOR_INVALID==pCur->eState ){

  69035.       return SQLITE_DONE;

  69036.     }

  69037.     if( CURSOR_SKIPNEXT==pCur->eState ){

  69038.       pCur->eState = CURSOR_VALID;

  69039.       if( pCur->skipNext<0 ) return SQLITE_OK;

  69040.     }

  69041.   }

  69042. 

  69043.   pPage = pCur->pPage;

  69044.   assert( pPage->isInit );

  69045.   if( !pPage->leaf ){

  69046.     int idx = pCur->ix;

  69047.     rc = moveToChild(pCur, get4byte(findCell(pPage, idx)));

  69048.     if( rc ) return rc;

  69049.     rc = moveToRightmost(pCur);

  69050.   }else{

  69051.     while( pCur->ix==0 ){

  69052.       if( pCur->iPage==0 ){

  69053.         pCur->eState = CURSOR_INVALID;

  69054.         return SQLITE_DONE;

  69055.       }

  69056.       moveToParent(pCur);

  69057.     }

  69058.     assert( pCur->info.nSize==0 );

  69059.     assert( (pCur->curFlags & (BTCF_ValidOvfl))==0 );

  69060. 

  69061.     pCur->ix--;

  69062.     pPage = pCur->pPage;

  69063.     if( pPage->intKey && !pPage->leaf ){

  69064.       rc = sqlite3BtreePrevious(pCur, 0);

  69065.     }else{

  69066.       rc = SQLITE_OK;

  69067.     }

  69068.   }

  69069.   return rc;

  69070. }

  69071. SQLITE_PRIVATE int sqlite3BtreePrevious(BtCursor *pCur, int flags){

  69072.   assert( cursorOwnsBtShared(pCur) );

  69073.   assert( flags==0 || flags==1 );

  69074.   UNUSED_PARAMETER( flags );  /* Used in COMDB2 but not native SQLite */

  69075.   pCur->curFlags &= ~(BTCF_AtLast|BTCF_ValidOvfl|BTCF_ValidNKey);

  69076.   pCur->info.nSize = 0;

  69077.   if( pCur->eState!=CURSOR_VALID

  69078.    || pCur->ix==0

  69079.    || pCur->pPage->leaf==0

  69080.   ){

  69081.     return btreePrevious(pCur);

  69082.   }

  69083.   pCur->ix--;

  69084.   return SQLITE_OK;

  69085. }

  69086. 

  69087. /*

  69088. ** Allocate a new page from the database file.

  69089. **

  69090. ** The new page is marked as dirty.  (In other words, sqlite3PagerWrite()

  69091. ** has already been called on the new page.)  The new page has also

  69092. ** been referenced and the calling routine is responsible for calling

  69093. ** sqlite3PagerUnref() on the new page when it is done.

  69094. **

  69095. ** SQLITE_OK is returned on success.  Any other return value indicates

  69096. ** an error.  *ppPage is set to NULL in the event of an error.

  69097. **

  69098. ** If the "nearby" parameter is not 0, then an effort is made to 

  69099. ** locate a page close to the page number "nearby".  This can be used in an

  69100. ** attempt to keep related pages close to each other in the database file,

  69101. ** which in turn can make database access faster.

  69102. **

  69103. ** If the eMode parameter is BTALLOC_EXACT and the nearby page exists

  69104. ** anywhere on the free-list, then it is guaranteed to be returned.  If

  69105. ** eMode is BTALLOC_LT then the page returned will be less than or equal

  69106. ** to nearby if any such page exists.  If eMode is BTALLOC_ANY then there

  69107. ** are no restrictions on which page is returned.

  69108. */

  69109. static int allocateBtreePage(

  69110.   BtShared *pBt,         /* The btree */

  69111.   MemPage **ppPage,      /* Store pointer to the allocated page here */

  69112.   Pgno *pPgno,           /* Store the page number here */

  69113.   Pgno nearby,           /* Search for a page near this one */

  69114.   u8 eMode               /* BTALLOC_EXACT, BTALLOC_LT, or BTALLOC_ANY */

  69115. ){

  69116.   MemPage *pPage1;

  69117.   int rc;

  69118.   u32 n;     /* Number of pages on the freelist */

  69119.   u32 k;     /* Number of leaves on the trunk of the freelist */

  69120.   MemPage *pTrunk = 0;

  69121.   MemPage *pPrevTrunk = 0;

  69122.   Pgno mxPage;     /* Total size of the database file */

  69123. 

  69124.   assert( sqlite3_mutex_held(pBt->mutex) );

  69125.   assert( eMode==BTALLOC_ANY || (nearby>0 && IfNotOmitAV(pBt->autoVacuum)) );

  69126.   pPage1 = pBt->pPage1;

  69127.   mxPage = btreePagecount(pBt);

  69128.   /* EVIDENCE-OF: R-05119-02637 The 4-byte big-endian integer at offset 36

  69129.   ** stores stores the total number of pages on the freelist. */

  69130.   n = get4byte(&pPage1->aData[36]);

  69131.   testcase( n==mxPage-1 );

  69132.   if( n>=mxPage ){

  69133.     return SQLITE_CORRUPT_BKPT;

  69134.   }

  69135.   if( n>0 ){

  69136.     /* There are pages on the freelist.  Reuse one of those pages. */

  69137.     Pgno iTrunk;

  69138.     u8 searchList = 0; /* If the free-list must be searched for 'nearby' */

  69139.     u32 nSearch = 0;   /* Count of the number of search attempts */

  69140.     

  69141.     /* If eMode==BTALLOC_EXACT and a query of the pointer-map

  69142.     ** shows that the page 'nearby' is somewhere on the free-list, then

  69143.     ** the entire-list will be searched for that page.

  69144.     */

  69145. #ifndef SQLITE_OMIT_AUTOVACUUM

  69146.     if( eMode==BTALLOC_EXACT ){

  69147.       if( nearby<=mxPage ){

  69148.         u8 eType;

  69149.         assert( nearby>0 );

  69150.         assert( pBt->autoVacuum );

  69151.         rc = ptrmapGet(pBt, nearby, &eType, 0);

  69152.         if( rc ) return rc;

  69153.         if( eType==PTRMAP_FREEPAGE ){

  69154.           searchList = 1;

  69155.         }

  69156.       }

  69157.     }else if( eMode==BTALLOC_LE ){

  69158.       searchList = 1;

  69159.     }

  69160. #endif

  69161. 

  69162.     /* Decrement the free-list count by 1. Set iTrunk to the index of the

  69163.     ** first free-list trunk page. iPrevTrunk is initially 1.

  69164.     */

  69165.     rc = sqlite3PagerWrite(pPage1->pDbPage);

  69166.     if( rc ) return rc;

  69167.     put4byte(&pPage1->aData[36], n-1);

  69168. 

  69169.     /* The code within this loop is run only once if the 'searchList' variable

  69170.     ** is not true. Otherwise, it runs once for each trunk-page on the

  69171.     ** free-list until the page 'nearby' is located (eMode==BTALLOC_EXACT)

  69172.     ** or until a page less than 'nearby' is located (eMode==BTALLOC_LT)

  69173.     */

  69174.     do {

  69175.       pPrevTrunk = pTrunk;

  69176.       if( pPrevTrunk ){

  69177.         /* EVIDENCE-OF: R-01506-11053 The first integer on a freelist trunk page

  69178.         ** is the page number of the next freelist trunk page in the list or

  69179.         ** zero if this is the last freelist trunk page. */

  69180.         iTrunk = get4byte(&pPrevTrunk->aData[0]);

  69181.       }else{

  69182.         /* EVIDENCE-OF: R-59841-13798 The 4-byte big-endian integer at offset 32

  69183.         ** stores the page number of the first page of the freelist, or zero if

  69184.         ** the freelist is empty. */

  69185.         iTrunk = get4byte(&pPage1->aData[32]);

  69186.       }

  69187.       testcase( iTrunk==mxPage );

  69188.       if( iTrunk>mxPage || nSearch++ > n ){

  69189.         rc = SQLITE_CORRUPT_PGNO(pPrevTrunk ? pPrevTrunk->pgno : 1);

  69190.       }else{

  69191.         rc = btreeGetUnusedPage(pBt, iTrunk, &pTrunk, 0);

  69192.       }

  69193.       if( rc ){

  69194.         pTrunk = 0;

  69195.         goto end_allocate_page;

  69196.       }

  69197.       assert( pTrunk!=0 );

  69198.       assert( pTrunk->aData!=0 );

  69199.       /* EVIDENCE-OF: R-13523-04394 The second integer on a freelist trunk page

  69200.       ** is the number of leaf page pointers to follow. */

  69201.       k = get4byte(&pTrunk->aData[4]);

  69202.       if( k==0 && !searchList ){

  69203.         /* The trunk has no leaves and the list is not being searched. 

  69204.         ** So extract the trunk page itself and use it as the newly 

  69205.         ** allocated page */

  69206.         assert( pPrevTrunk==0 );

  69207.         rc = sqlite3PagerWrite(pTrunk->pDbPage);

  69208.         if( rc ){

  69209.           goto end_allocate_page;

  69210.         }

  69211.         *pPgno = iTrunk;

  69212.         memcpy(&pPage1->aData[32], &pTrunk->aData[0], 4);

  69213.         *ppPage = pTrunk;

  69214.         pTrunk = 0;

  69215.         TRACE(("ALLOCATE: %d trunk - %d free pages left\n", *pPgno, n-1));

  69216.       }else if( k>(u32)(pBt->usableSize/4 - 2) ){

  69217.         /* Value of k is out of range.  Database corruption */

  69218.         rc = SQLITE_CORRUPT_PGNO(iTrunk);

  69219.         goto end_allocate_page;

  69220. #ifndef SQLITE_OMIT_AUTOVACUUM

  69221.       }else if( searchList 

  69222.             && (nearby==iTrunk || (iTrunk<nearby && eMode==BTALLOC_LE)) 

  69223.       ){

  69224.         /* The list is being searched and this trunk page is the page

  69225.         ** to allocate, regardless of whether it has leaves.

  69226.         */

  69227.         *pPgno = iTrunk;

  69228.         *ppPage = pTrunk;

  69229.         searchList = 0;

  69230.         rc = sqlite3PagerWrite(pTrunk->pDbPage);

  69231.         if( rc ){

  69232.           goto end_allocate_page;

  69233.         }

  69234.         if( k==0 ){

  69235.           if( !pPrevTrunk ){

  69236.             memcpy(&pPage1->aData[32], &pTrunk->aData[0], 4);

  69237.           }else{

  69238.             rc = sqlite3PagerWrite(pPrevTrunk->pDbPage);

  69239.             if( rc!=SQLITE_OK ){

  69240.               goto end_allocate_page;

  69241.             }

  69242.             memcpy(&pPrevTrunk->aData[0], &pTrunk->aData[0], 4);

  69243.           }

  69244.         }else{

  69245.           /* The trunk page is required by the caller but it contains 

  69246.           ** pointers to free-list leaves. The first leaf becomes a trunk

  69247.           ** page in this case.

  69248.           */

  69249.           MemPage *pNewTrunk;

  69250.           Pgno iNewTrunk = get4byte(&pTrunk->aData[8]);

  69251.           if( iNewTrunk>mxPage ){ 

  69252.             rc = SQLITE_CORRUPT_PGNO(iTrunk);

  69253.             goto end_allocate_page;

  69254.           }

  69255.           testcase( iNewTrunk==mxPage );

  69256.           rc = btreeGetUnusedPage(pBt, iNewTrunk, &pNewTrunk, 0);

  69257.           if( rc!=SQLITE_OK ){

  69258.             goto end_allocate_page;

  69259.           }

  69260.           rc = sqlite3PagerWrite(pNewTrunk->pDbPage);

  69261.           if( rc!=SQLITE_OK ){

  69262.             releasePage(pNewTrunk);

  69263.             goto end_allocate_page;

  69264.           }

  69265.           memcpy(&pNewTrunk->aData[0], &pTrunk->aData[0], 4);

  69266.           put4byte(&pNewTrunk->aData[4], k-1);

  69267.           memcpy(&pNewTrunk->aData[8], &pTrunk->aData[12], (k-1)*4);

  69268.           releasePage(pNewTrunk);

  69269.           if( !pPrevTrunk ){

  69270.             assert( sqlite3PagerIswriteable(pPage1->pDbPage) );

  69271.             put4byte(&pPage1->aData[32], iNewTrunk);

  69272.           }else{

  69273.             rc = sqlite3PagerWrite(pPrevTrunk->pDbPage);

  69274.             if( rc ){

  69275.               goto end_allocate_page;

  69276.             }

  69277.             put4byte(&pPrevTrunk->aData[0], iNewTrunk);

  69278.           }

  69279.         }

  69280.         pTrunk = 0;

  69281.         TRACE(("ALLOCATE: %d trunk - %d free pages left\n", *pPgno, n-1));

  69282. #endif

  69283.       }else if( k>0 ){

  69284.         /* Extract a leaf from the trunk */

  69285.         u32 closest;

  69286.         Pgno iPage;

  69287.         unsigned char *aData = pTrunk->aData;

  69288.         if( nearby>0 ){

  69289.           u32 i;

  69290.           closest = 0;

  69291.           if( eMode==BTALLOC_LE ){

  69292.             for(i=0; i<k; i++){

  69293.               iPage = get4byte(&aData[8+i*4]);

  69294.               if( iPage<=nearby ){

  69295.                 closest = i;

  69296.                 break;

  69297.               }

  69298.             }

  69299.           }else{

  69300.             int dist;

  69301.             dist = sqlite3AbsInt32(get4byte(&aData[8]) - nearby);

  69302.             for(i=1; i<k; i++){

  69303.               int d2 = sqlite3AbsInt32(get4byte(&aData[8+i*4]) - nearby);

  69304.               if( d2<dist ){

  69305.                 closest = i;

  69306.                 dist = d2;

  69307.               }

  69308.             }

  69309.           }

  69310.         }else{

  69311.           closest = 0;

  69312.         }

  69313. 

  69314.         iPage = get4byte(&aData[8+closest*4]);

  69315.         testcase( iPage==mxPage );

  69316.         if( iPage>mxPage ){

  69317.           rc = SQLITE_CORRUPT_PGNO(iTrunk);

  69318.           goto end_allocate_page;

  69319.         }

  69320.         testcase( iPage==mxPage );

  69321.         if( !searchList 

  69322.          || (iPage==nearby || (iPage<nearby && eMode==BTALLOC_LE)) 

  69323.         ){

  69324.           int noContent;

  69325.           *pPgno = iPage;

  69326.           TRACE(("ALLOCATE: %d was leaf %d of %d on trunk %d"

  69327.                  ": %d more free pages\n",

  69328.                  *pPgno, closest+1, k, pTrunk->pgno, n-1));

  69329.           rc = sqlite3PagerWrite(pTrunk->pDbPage);

  69330.           if( rc ) goto end_allocate_page;

  69331.           if( closest<k-1 ){

  69332.             memcpy(&aData[8+closest*4], &aData[4+k*4], 4);

  69333.           }

  69334.           put4byte(&aData[4], k-1);

  69335.           noContent = !btreeGetHasContent(pBt, *pPgno)? PAGER_GET_NOCONTENT : 0;

  69336.           rc = btreeGetUnusedPage(pBt, *pPgno, ppPage, noContent);

  69337.           if( rc==SQLITE_OK ){

  69338.             rc = sqlite3PagerWrite((*ppPage)->pDbPage);

  69339.             if( rc!=SQLITE_OK ){

  69340.               releasePage(*ppPage);

  69341.               *ppPage = 0;

  69342.             }

  69343.           }

  69344.           searchList = 0;

  69345.         }

  69346.       }

  69347.       releasePage(pPrevTrunk);

  69348.       pPrevTrunk = 0;

  69349.     }while( searchList );

  69350.   }else{

  69351.     /* There are no pages on the freelist, so append a new page to the

  69352.     ** database image.

  69353.     **

  69354.     ** Normally, new pages allocated by this block can be requested from the

  69355.     ** pager layer with the 'no-content' flag set. This prevents the pager

  69356.     ** from trying to read the pages content from disk. However, if the

  69357.     ** current transaction has already run one or more incremental-vacuum

  69358.     ** steps, then the page we are about to allocate may contain content

  69359.     ** that is required in the event of a rollback. In this case, do

  69360.     ** not set the no-content flag. This causes the pager to load and journal

  69361.     ** the current page content before overwriting it.

  69362.     **

  69363.     ** Note that the pager will not actually attempt to load or journal 

  69364.     ** content for any page that really does lie past the end of the database

  69365.     ** file on disk. So the effects of disabling the no-content optimization

  69366.     ** here are confined to those pages that lie between the end of the

  69367.     ** database image and the end of the database file.

  69368.     */

  69369.     int bNoContent = (0==IfNotOmitAV(pBt->bDoTruncate))? PAGER_GET_NOCONTENT:0;

  69370. 

  69371.     rc = sqlite3PagerWrite(pBt->pPage1->pDbPage);

  69372.     if( rc ) return rc;

  69373.     pBt->nPage++;

  69374.     if( pBt->nPage==PENDING_BYTE_PAGE(pBt) ) pBt->nPage++;

  69375. 

  69376. #ifndef SQLITE_OMIT_AUTOVACUUM

  69377.     if( pBt->autoVacuum && PTRMAP_ISPAGE(pBt, pBt->nPage) ){

  69378.       /* If *pPgno refers to a pointer-map page, allocate two new pages

  69379.       ** at the end of the file instead of one. The first allocated page

  69380.       ** becomes a new pointer-map page, the second is used by the caller.

  69381.       */

  69382.       MemPage *pPg = 0;

  69383.       TRACE(("ALLOCATE: %d from end of file (pointer-map page)\n", pBt->nPage));

  69384.       assert( pBt->nPage!=PENDING_BYTE_PAGE(pBt) );

  69385.       rc = btreeGetUnusedPage(pBt, pBt->nPage, &pPg, bNoContent);

  69386.       if( rc==SQLITE_OK ){

  69387.         rc = sqlite3PagerWrite(pPg->pDbPage);

  69388.         releasePage(pPg);

  69389.       }

  69390.       if( rc ) return rc;

  69391.       pBt->nPage++;

  69392.       if( pBt->nPage==PENDING_BYTE_PAGE(pBt) ){ pBt->nPage++; }

  69393.     }

  69394. #endif

  69395.     put4byte(28 + (u8*)pBt->pPage1->aData, pBt->nPage);

  69396.     *pPgno = pBt->nPage;

  69397. 

  69398.     assert( *pPgno!=PENDING_BYTE_PAGE(pBt) );

  69399.     rc = btreeGetUnusedPage(pBt, *pPgno, ppPage, bNoContent);

  69400.     if( rc ) return rc;

  69401.     rc = sqlite3PagerWrite((*ppPage)->pDbPage);

  69402.     if( rc!=SQLITE_OK ){

  69403.       releasePage(*ppPage);

  69404.       *ppPage = 0;

  69405.     }

  69406.     TRACE(("ALLOCATE: %d from end of file\n", *pPgno));

  69407.   }

  69408. 

  69409.   assert( CORRUPT_DB || *pPgno!=PENDING_BYTE_PAGE(pBt) );

  69410. 

  69411. end_allocate_page:

  69412.   releasePage(pTrunk);

  69413.   releasePage(pPrevTrunk);

  69414.   assert( rc!=SQLITE_OK || sqlite3PagerPageRefcount((*ppPage)->pDbPage)<=1 );

  69415.   assert( rc!=SQLITE_OK || (*ppPage)->isInit==0 );

  69416.   return rc;

  69417. }

  69418. 

  69419. /*

  69420. ** This function is used to add page iPage to the database file free-list. 

  69421. ** It is assumed that the page is not already a part of the free-list.

  69422. **

  69423. ** The value passed as the second argument to this function is optional.

  69424. ** If the caller happens to have a pointer to the MemPage object 

  69425. ** corresponding to page iPage handy, it may pass it as the second value. 

  69426. ** Otherwise, it may pass NULL.

  69427. **

  69428. ** If a pointer to a MemPage object is passed as the second argument,

  69429. ** its reference count is not altered by this function.

  69430. */

  69431. static int freePage2(BtShared *pBt, MemPage *pMemPage, Pgno iPage){

  69432.   MemPage *pTrunk = 0;                /* Free-list trunk page */

  69433.   Pgno iTrunk = 0;                    /* Page number of free-list trunk page */ 

  69434.   MemPage *pPage1 = pBt->pPage1;      /* Local reference to page 1 */

  69435.   MemPage *pPage;                     /* Page being freed. May be NULL. */

  69436.   int rc;                             /* Return Code */

  69437.   u32 nFree;                          /* Initial number of pages on free-list */

  69438. 

  69439.   assert( sqlite3_mutex_held(pBt->mutex) );

  69440.   assert( CORRUPT_DB || iPage>1 );

  69441.   assert( !pMemPage || pMemPage->pgno==iPage );

  69442. 

  69443.   if( iPage<2 || iPage>pBt->nPage ){

  69444.     return SQLITE_CORRUPT_BKPT;

  69445.   }

  69446.   if( pMemPage ){

  69447.     pPage = pMemPage;

  69448.     sqlite3PagerRef(pPage->pDbPage);

  69449.   }else{

  69450.     pPage = btreePageLookup(pBt, iPage);

  69451.   }

  69452. 

  69453.   /* Increment the free page count on pPage1 */

  69454.   rc = sqlite3PagerWrite(pPage1->pDbPage);

  69455.   if( rc ) goto freepage_out;

  69456.   nFree = get4byte(&pPage1->aData[36]);

  69457.   put4byte(&pPage1->aData[36], nFree+1);

  69458. 

  69459.   if( pBt->btsFlags & BTS_SECURE_DELETE ){

  69460.     /* If the secure_delete option is enabled, then

  69461.     ** always fully overwrite deleted information with zeros.

  69462.     */

  69463.     if( (!pPage && ((rc = btreeGetPage(pBt, iPage, &pPage, 0))!=0) )

  69464.      ||            ((rc = sqlite3PagerWrite(pPage->pDbPage))!=0)

  69465.     ){

  69466.       goto freepage_out;

  69467.     }

  69468.     memset(pPage->aData, 0, pPage->pBt->pageSize);

  69469.   }

  69470. 

  69471.   /* If the database supports auto-vacuum, write an entry in the pointer-map

  69472.   ** to indicate that the page is free.

  69473.   */

  69474.   if( ISAUTOVACUUM ){

  69475.     ptrmapPut(pBt, iPage, PTRMAP_FREEPAGE, 0, &rc);

  69476.     if( rc ) goto freepage_out;

  69477.   }

  69478. 

  69479.   /* Now manipulate the actual database free-list structure. There are two

  69480.   ** possibilities. If the free-list is currently empty, or if the first

  69481.   ** trunk page in the free-list is full, then this page will become a

  69482.   ** new free-list trunk page. Otherwise, it will become a leaf of the

  69483.   ** first trunk page in the current free-list. This block tests if it

  69484.   ** is possible to add the page as a new free-list leaf.

  69485.   */

  69486.   if( nFree!=0 ){

  69487.     u32 nLeaf;                /* Initial number of leaf cells on trunk page */

  69488. 

  69489.     iTrunk = get4byte(&pPage1->aData[32]);

  69490.     rc = btreeGetPage(pBt, iTrunk, &pTrunk, 0);

  69491.     if( rc!=SQLITE_OK ){

  69492.       goto freepage_out;

  69493.     }

  69494. 

  69495.     nLeaf = get4byte(&pTrunk->aData[4]);

  69496.     assert( pBt->usableSize>32 );

  69497.     if( nLeaf > (u32)pBt->usableSize/4 - 2 ){

  69498.       rc = SQLITE_CORRUPT_BKPT;

  69499.       goto freepage_out;

  69500.     }

  69501.     if( nLeaf < (u32)pBt->usableSize/4 - 8 ){

  69502.       /* In this case there is room on the trunk page to insert the page

  69503.       ** being freed as a new leaf.

  69504.       **

  69505.       ** Note that the trunk page is not really full until it contains

  69506.       ** usableSize/4 - 2 entries, not usableSize/4 - 8 entries as we have

  69507.       ** coded.  But due to a coding error in versions of SQLite prior to

  69508.       ** 3.6.0, databases with freelist trunk pages holding more than

  69509.       ** usableSize/4 - 8 entries will be reported as corrupt.  In order

  69510.       ** to maintain backwards compatibility with older versions of SQLite,

  69511.       ** we will continue to restrict the number of entries to usableSize/4 - 8

  69512.       ** for now.  At some point in the future (once everyone has upgraded

  69513.       ** to 3.6.0 or later) we should consider fixing the conditional above

  69514.       ** to read "usableSize/4-2" instead of "usableSize/4-8".

  69515.       **

  69516.       ** EVIDENCE-OF: R-19920-11576 However, newer versions of SQLite still

  69517.       ** avoid using the last six entries in the freelist trunk page array in

  69518.       ** order that database files created by newer versions of SQLite can be

  69519.       ** read by older versions of SQLite.

  69520.       */

  69521.       rc = sqlite3PagerWrite(pTrunk->pDbPage);

  69522.       if( rc==SQLITE_OK ){

  69523.         put4byte(&pTrunk->aData[4], nLeaf+1);

  69524.         put4byte(&pTrunk->aData[8+nLeaf*4], iPage);

  69525.         if( pPage && (pBt->btsFlags & BTS_SECURE_DELETE)==0 ){

  69526.           sqlite3PagerDontWrite(pPage->pDbPage);

  69527.         }

  69528.         rc = btreeSetHasContent(pBt, iPage);

  69529.       }

  69530.       TRACE(("FREE-PAGE: %d leaf on trunk page %d\n",pPage->pgno,pTrunk->pgno));

  69531.       goto freepage_out;

  69532.     }

  69533.   }

  69534. 

  69535.   /* If control flows to this point, then it was not possible to add the

  69536.   ** the page being freed as a leaf page of the first trunk in the free-list.

  69537.   ** Possibly because the free-list is empty, or possibly because the 

  69538.   ** first trunk in the free-list is full. Either way, the page being freed

  69539.   ** will become the new first trunk page in the free-list.

  69540.   */

  69541.   if( pPage==0 && SQLITE_OK!=(rc = btreeGetPage(pBt, iPage, &pPage, 0)) ){

  69542.     goto freepage_out;

  69543.   }

  69544.   rc = sqlite3PagerWrite(pPage->pDbPage);

  69545.   if( rc!=SQLITE_OK ){

  69546.     goto freepage_out;

  69547.   }

  69548.   put4byte(pPage->aData, iTrunk);

  69549.   put4byte(&pPage->aData[4], 0);

  69550.   put4byte(&pPage1->aData[32], iPage);

  69551.   TRACE(("FREE-PAGE: %d new trunk page replacing %d\n", pPage->pgno, iTrunk));

  69552. 

  69553. freepage_out:

  69554.   if( pPage ){

  69555.     pPage->isInit = 0;

  69556.   }

  69557.   releasePage(pPage);

  69558.   releasePage(pTrunk);

  69559.   return rc;

  69560. }

  69561. static void freePage(MemPage *pPage, int *pRC){

  69562.   if( (*pRC)==SQLITE_OK ){

  69563.     *pRC = freePage2(pPage->pBt, pPage, pPage->pgno);

  69564.   }

  69565. }

  69566. 

  69567. /*

  69568. ** Free any overflow pages associated with the given Cell.  Store

  69569. ** size information about the cell in pInfo.

  69570. */

  69571. static int clearCell(

  69572.   MemPage *pPage,          /* The page that contains the Cell */

  69573.   unsigned char *pCell,    /* First byte of the Cell */

  69574.   CellInfo *pInfo          /* Size information about the cell */

  69575. ){

  69576.   BtShared *pBt;

  69577.   Pgno ovflPgno;

  69578.   int rc;

  69579.   int nOvfl;

  69580.   u32 ovflPageSize;

  69581. 

  69582.   assert( sqlite3_mutex_held(pPage->pBt->mutex) );

  69583.   pPage->xParseCell(pPage, pCell, pInfo);

  69584.   if( pInfo->nLocal==pInfo->nPayload ){

  69585.     return SQLITE_OK;  /* No overflow pages. Return without doing anything */

  69586.   }

  69587.   testcase( pCell + pInfo->nSize == pPage->aDataEnd );

  69588.   testcase( pCell + (pInfo->nSize-1) == pPage->aDataEnd );

  69589.   if( pCell + pInfo->nSize > pPage->aDataEnd ){

  69590.     /* Cell extends past end of page */

  69591.     return SQLITE_CORRUPT_PAGE(pPage);

  69592.   }

  69593.   ovflPgno = get4byte(pCell + pInfo->nSize - 4);

  69594.   pBt = pPage->pBt;

  69595.   assert( pBt->usableSize > 4 );

  69596.   ovflPageSize = pBt->usableSize - 4;

  69597.   nOvfl = (pInfo->nPayload - pInfo->nLocal + ovflPageSize - 1)/ovflPageSize;

  69598.   assert( nOvfl>0 || 

  69599.     (CORRUPT_DB && (pInfo->nPayload + ovflPageSize)<ovflPageSize)

  69600.   );

  69601.   while( nOvfl-- ){

  69602.     Pgno iNext = 0;

  69603.     MemPage *pOvfl = 0;

  69604.     if( ovflPgno<2 || ovflPgno>btreePagecount(pBt) ){

  69605.       /* 0 is not a legal page number and page 1 cannot be an 

  69606.       ** overflow page. Therefore if ovflPgno<2 or past the end of the 

  69607.       ** file the database must be corrupt. */

  69608.       return SQLITE_CORRUPT_BKPT;

  69609.     }

  69610.     if( nOvfl ){

  69611.       rc = getOverflowPage(pBt, ovflPgno, &pOvfl, &iNext);

  69612.       if( rc ) return rc;

  69613.     }

  69614. 

  69615.     if( ( pOvfl || ((pOvfl = btreePageLookup(pBt, ovflPgno))!=0) )

  69616.      && sqlite3PagerPageRefcount(pOvfl->pDbPage)!=1

  69617.     ){

  69618.       /* There is no reason any cursor should have an outstanding reference 

  69619.       ** to an overflow page belonging to a cell that is being deleted/updated.

  69620.       ** So if there exists more than one reference to this page, then it 

  69621.       ** must not really be an overflow page and the database must be corrupt. 

  69622.       ** It is helpful to detect this before calling freePage2(), as 

  69623.       ** freePage2() may zero the page contents if secure-delete mode is

  69624.       ** enabled. If this 'overflow' page happens to be a page that the

  69625.       ** caller is iterating through or using in some other way, this

  69626.       ** can be problematic.

  69627.       */

  69628.       rc = SQLITE_CORRUPT_BKPT;

  69629.     }else{

  69630.       rc = freePage2(pBt, pOvfl, ovflPgno);

  69631.     }

  69632. 

  69633.     if( pOvfl ){

  69634.       sqlite3PagerUnref(pOvfl->pDbPage);

  69635.     }

  69636.     if( rc ) return rc;

  69637.     ovflPgno = iNext;

  69638.   }

  69639.   return SQLITE_OK;

  69640. }

  69641. 

  69642. /*

  69643. ** Create the byte sequence used to represent a cell on page pPage

  69644. ** and write that byte sequence into pCell[].  Overflow pages are

  69645. ** allocated and filled in as necessary.  The calling procedure

  69646. ** is responsible for making sure sufficient space has been allocated

  69647. ** for pCell[].

  69648. **

  69649. ** Note that pCell does not necessary need to point to the pPage->aData

  69650. ** area.  pCell might point to some temporary storage.  The cell will

  69651. ** be constructed in this temporary area then copied into pPage->aData

  69652. ** later.

  69653. */

  69654. static int fillInCell(

  69655.   MemPage *pPage,                /* The page that contains the cell */

  69656.   unsigned char *pCell,          /* Complete text of the cell */

  69657.   const BtreePayload *pX,        /* Payload with which to construct the cell */

  69658.   int *pnSize                    /* Write cell size here */

  69659. ){

  69660.   int nPayload;

  69661.   const u8 *pSrc;

  69662.   int nSrc, n, rc, mn;

  69663.   int spaceLeft;

  69664.   MemPage *pToRelease;

  69665.   unsigned char *pPrior;

  69666.   unsigned char *pPayload;

  69667.   BtShared *pBt;

  69668.   Pgno pgnoOvfl;

  69669.   int nHeader;

  69670. 

  69671.   assert( sqlite3_mutex_held(pPage->pBt->mutex) );

  69672. 

  69673.   /* pPage is not necessarily writeable since pCell might be auxiliary

  69674.   ** buffer space that is separate from the pPage buffer area */

  69675.   assert( pCell<pPage->aData || pCell>=&pPage->aData[pPage->pBt->pageSize]

  69676.             || sqlite3PagerIswriteable(pPage->pDbPage) );

  69677. 

  69678.   /* Fill in the header. */

  69679.   nHeader = pPage->childPtrSize;

  69680.   if( pPage->intKey ){

  69681.     nPayload = pX->nData + pX->nZero;

  69682.     pSrc = pX->pData;

  69683.     nSrc = pX->nData;

  69684.     assert( pPage->intKeyLeaf ); /* fillInCell() only called for leaves */

  69685.     nHeader += putVarint32(&pCell[nHeader], nPayload);

  69686.     nHeader += putVarint(&pCell[nHeader], *(u64*)&pX->nKey);

  69687.   }else{

  69688.     assert( pX->nKey<=0x7fffffff && pX->pKey!=0 );

  69689.     nSrc = nPayload = (int)pX->nKey;

  69690.     pSrc = pX->pKey;

  69691.     nHeader += putVarint32(&pCell[nHeader], nPayload);

  69692.   }

  69693.   

  69694.   /* Fill in the payload */

  69695.   pPayload = &pCell[nHeader];

  69696.   if( nPayload<=pPage->maxLocal ){

  69697.     /* This is the common case where everything fits on the btree page

  69698.     ** and no overflow pages are required. */

  69699.     n = nHeader + nPayload;

  69700.     testcase( n==3 );

  69701.     testcase( n==4 );

  69702.     if( n<4 ) n = 4;

  69703.     *pnSize = n;

  69704.     assert( nSrc<=nPayload );

  69705.     testcase( nSrc<nPayload );

  69706.     memcpy(pPayload, pSrc, nSrc);

  69707.     memset(pPayload+nSrc, 0, nPayload-nSrc);

  69708.     return SQLITE_OK;

  69709.   }

  69710. 

  69711.   /* If we reach this point, it means that some of the content will need

  69712.   ** to spill onto overflow pages.

  69713.   */

  69714.   mn = pPage->minLocal;

  69715.   n = mn + (nPayload - mn) % (pPage->pBt->usableSize - 4);

  69716.   testcase( n==pPage->maxLocal );

  69717.   testcase( n==pPage->maxLocal+1 );

  69718.   if( n > pPage->maxLocal ) n = mn;

  69719.   spaceLeft = n;

  69720.   *pnSize = n + nHeader + 4;

  69721.   pPrior = &pCell[nHeader+n];

  69722.   pToRelease = 0;

  69723.   pgnoOvfl = 0;

  69724.   pBt = pPage->pBt;

  69725. 

  69726.   /* At this point variables should be set as follows:

  69727.   **

  69728.   **   nPayload           Total payload size in bytes

  69729.   **   pPayload           Begin writing payload here

  69730.   **   spaceLeft          Space available at pPayload.  If nPayload>spaceLeft,

  69731.   **                      that means content must spill into overflow pages.

  69732.   **   *pnSize            Size of the local cell (not counting overflow pages)

  69733.   **   pPrior             Where to write the pgno of the first overflow page

  69734.   **

  69735.   ** Use a call to btreeParseCellPtr() to verify that the values above

  69736.   ** were computed correctly.

  69737.   */

  69738. #ifdef SQLITE_DEBUG

  69739.   {

  69740.     CellInfo info;

  69741.     pPage->xParseCell(pPage, pCell, &info);

  69742.     assert( nHeader==(int)(info.pPayload - pCell) );

  69743.     assert( info.nKey==pX->nKey );

  69744.     assert( *pnSize == info.nSize );

  69745.     assert( spaceLeft == info.nLocal );

  69746.   }

  69747. #endif

  69748. 

  69749.   /* Write the payload into the local Cell and any extra into overflow pages */

  69750.   while( 1 ){

  69751.     n = nPayload;

  69752.     if( n>spaceLeft ) n = spaceLeft;

  69753. 

  69754.     /* If pToRelease is not zero than pPayload points into the data area

  69755.     ** of pToRelease.  Make sure pToRelease is still writeable. */

  69756.     assert( pToRelease==0 || sqlite3PagerIswriteable(pToRelease->pDbPage) );

  69757. 

  69758.     /* If pPayload is part of the data area of pPage, then make sure pPage

  69759.     ** is still writeable */

  69760.     assert( pPayload<pPage->aData || pPayload>=&pPage->aData[pBt->pageSize]

  69761.             || sqlite3PagerIswriteable(pPage->pDbPage) );

  69762. 

  69763.     if( nSrc>=n ){

  69764.       memcpy(pPayload, pSrc, n);

  69765.     }else if( nSrc>0 ){

  69766.       n = nSrc;

  69767.       memcpy(pPayload, pSrc, n);

  69768.     }else{

  69769.       memset(pPayload, 0, n);

  69770.     }

  69771.     nPayload -= n;

  69772.     if( nPayload<=0 ) break;

  69773.     pPayload += n;

  69774.     pSrc += n;

  69775.     nSrc -= n;

  69776.     spaceLeft -= n;

  69777.     if( spaceLeft==0 ){

  69778.       MemPage *pOvfl = 0;

  69779. #ifndef SQLITE_OMIT_AUTOVACUUM

  69780.       Pgno pgnoPtrmap = pgnoOvfl; /* Overflow page pointer-map entry page */

  69781.       if( pBt->autoVacuum ){

  69782.         do{

  69783.           pgnoOvfl++;

  69784.         } while( 

  69785.           PTRMAP_ISPAGE(pBt, pgnoOvfl) || pgnoOvfl==PENDING_BYTE_PAGE(pBt) 

  69786.         );

  69787.       }

  69788. #endif

  69789.       rc = allocateBtreePage(pBt, &pOvfl, &pgnoOvfl, pgnoOvfl, 0);

  69790. #ifndef SQLITE_OMIT_AUTOVACUUM

  69791.       /* If the database supports auto-vacuum, and the second or subsequent

  69792.       ** overflow page is being allocated, add an entry to the pointer-map

  69793.       ** for that page now. 

  69794.       **

  69795.       ** If this is the first overflow page, then write a partial entry 

  69796.       ** to the pointer-map. If we write nothing to this pointer-map slot,

  69797.       ** then the optimistic overflow chain processing in clearCell()

  69798.       ** may misinterpret the uninitialized values and delete the

  69799.       ** wrong pages from the database.

  69800.       */

  69801.       if( pBt->autoVacuum && rc==SQLITE_OK ){

  69802.         u8 eType = (pgnoPtrmap?PTRMAP_OVERFLOW2:PTRMAP_OVERFLOW1);

  69803.         ptrmapPut(pBt, pgnoOvfl, eType, pgnoPtrmap, &rc);

  69804.         if( rc ){

  69805.           releasePage(pOvfl);

  69806.         }

  69807.       }

  69808. #endif

  69809.       if( rc ){

  69810.         releasePage(pToRelease);

  69811.         return rc;

  69812.       }

  69813. 

  69814.       /* If pToRelease is not zero than pPrior points into the data area

  69815.       ** of pToRelease.  Make sure pToRelease is still writeable. */

  69816.       assert( pToRelease==0 || sqlite3PagerIswriteable(pToRelease->pDbPage) );

  69817. 

  69818.       /* If pPrior is part of the data area of pPage, then make sure pPage

  69819.       ** is still writeable */

  69820.       assert( pPrior<pPage->aData || pPrior>=&pPage->aData[pBt->pageSize]

  69821.             || sqlite3PagerIswriteable(pPage->pDbPage) );

  69822. 

  69823.       put4byte(pPrior, pgnoOvfl);

  69824.       releasePage(pToRelease);

  69825.       pToRelease = pOvfl;

  69826.       pPrior = pOvfl->aData;

  69827.       put4byte(pPrior, 0);

  69828.       pPayload = &pOvfl->aData[4];

  69829.       spaceLeft = pBt->usableSize - 4;

  69830.     }

  69831.   }

  69832.   releasePage(pToRelease);

  69833.   return SQLITE_OK;

  69834. }

  69835. 

  69836. /*

  69837. ** Remove the i-th cell from pPage.  This routine effects pPage only.

  69838. ** The cell content is not freed or deallocated.  It is assumed that

  69839. ** the cell content has been copied someplace else.  This routine just

  69840. ** removes the reference to the cell from pPage.

  69841. **

  69842. ** "sz" must be the number of bytes in the cell.

  69843. */

  69844. static void dropCell(MemPage *pPage, int idx, int sz, int *pRC){

  69845.   u32 pc;         /* Offset to cell content of cell being deleted */

  69846.   u8 *data;       /* pPage->aData */

  69847.   u8 *ptr;        /* Used to move bytes around within data[] */

  69848.   int rc;         /* The return code */

  69849.   int hdr;        /* Beginning of the header.  0 most pages.  100 page 1 */

  69850. 

  69851.   if( *pRC ) return;

  69852.   assert( idx>=0 && idx<pPage->nCell );

  69853.   assert( CORRUPT_DB || sz==cellSize(pPage, idx) );

  69854.   assert( sqlite3PagerIswriteable(pPage->pDbPage) );

  69855.   assert( sqlite3_mutex_held(pPage->pBt->mutex) );

  69856.   assert( pPage->nFree>=0 );

  69857.   data = pPage->aData;

  69858.   ptr = &pPage->aCellIdx[2*idx];

  69859.   pc = get2byte(ptr);

  69860.   hdr = pPage->hdrOffset;

  69861.   testcase( pc==get2byte(&data[hdr+5]) );

  69862.   testcase( pc+sz==pPage->pBt->usableSize );

  69863.   if( pc+sz > pPage->pBt->usableSize ){

  69864.     *pRC = SQLITE_CORRUPT_BKPT;

  69865.     return;

  69866.   }

  69867.   rc = freeSpace(pPage, pc, sz);

  69868.   if( rc ){

  69869.     *pRC = rc;

  69870.     return;

  69871.   }

  69872.   pPage->nCell--;

  69873.   if( pPage->nCell==0 ){

  69874.     memset(&data[hdr+1], 0, 4);

  69875.     data[hdr+7] = 0;

  69876.     put2byte(&data[hdr+5], pPage->pBt->usableSize);

  69877.     pPage->nFree = pPage->pBt->usableSize - pPage->hdrOffset

  69878.                        - pPage->childPtrSize - 8;

  69879.   }else{

  69880.     memmove(ptr, ptr+2, 2*(pPage->nCell - idx));

  69881.     put2byte(&data[hdr+3], pPage->nCell);

  69882.     pPage->nFree += 2;

  69883.   }

  69884. }

  69885. 

  69886. /*

  69887. ** Insert a new cell on pPage at cell index "i".  pCell points to the

  69888. ** content of the cell.

  69889. **

  69890. ** If the cell content will fit on the page, then put it there.  If it

  69891. ** will not fit, then make a copy of the cell content into pTemp if

  69892. ** pTemp is not null.  Regardless of pTemp, allocate a new entry

  69893. ** in pPage->apOvfl[] and make it point to the cell content (either

  69894. ** in pTemp or the original pCell) and also record its index. 

  69895. ** Allocating a new entry in pPage->aCell[] implies that 

  69896. ** pPage->nOverflow is incremented.

  69897. **

  69898. ** *pRC must be SQLITE_OK when this routine is called.

  69899. */

  69900. static void insertCell(

  69901.   MemPage *pPage,   /* Page into which we are copying */

  69902.   int i,            /* New cell becomes the i-th cell of the page */

  69903.   u8 *pCell,        /* Content of the new cell */

  69904.   int sz,           /* Bytes of content in pCell */

  69905.   u8 *pTemp,        /* Temp storage space for pCell, if needed */

  69906.   Pgno iChild,      /* If non-zero, replace first 4 bytes with this value */

  69907.   int *pRC          /* Read and write return code from here */

  69908. ){

  69909.   int idx = 0;      /* Where to write new cell content in data[] */

  69910.   int j;            /* Loop counter */

  69911.   u8 *data;         /* The content of the whole page */

  69912.   u8 *pIns;         /* The point in pPage->aCellIdx[] where no cell inserted */

  69913. 

  69914.   assert( *pRC==SQLITE_OK );

  69915.   assert( i>=0 && i<=pPage->nCell+pPage->nOverflow );

  69916.   assert( MX_CELL(pPage->pBt)<=10921 );

  69917.   assert( pPage->nCell<=MX_CELL(pPage->pBt) || CORRUPT_DB );

  69918.   assert( pPage->nOverflow<=ArraySize(pPage->apOvfl) );

  69919.   assert( ArraySize(pPage->apOvfl)==ArraySize(pPage->aiOvfl) );

  69920.   assert( sqlite3_mutex_held(pPage->pBt->mutex) );

  69921.   /* The cell should normally be sized correctly.  However, when moving a

  69922.   ** malformed cell from a leaf page to an interior page, if the cell size

  69923.   ** wanted to be less than 4 but got rounded up to 4 on the leaf, then size

  69924.   ** might be less than 8 (leaf-size + pointer) on the interior node.  Hence

  69925.   ** the term after the || in the following assert(). */

  69926.   assert( sz==pPage->xCellSize(pPage, pCell) || (sz==8 && iChild>0) );

  69927.   assert( pPage->nFree>=0 );

  69928.   if( pPage->nOverflow || sz+2>pPage->nFree ){

  69929.     if( pTemp ){

  69930.       memcpy(pTemp, pCell, sz);

  69931.       pCell = pTemp;

  69932.     }

  69933.     if( iChild ){

  69934.       put4byte(pCell, iChild);

  69935.     }

  69936.     j = pPage->nOverflow++;

  69937.     /* Comparison against ArraySize-1 since we hold back one extra slot

  69938.     ** as a contingency.  In other words, never need more than 3 overflow

  69939.     ** slots but 4 are allocated, just to be safe. */

  69940.     assert( j < ArraySize(pPage->apOvfl)-1 );

  69941.     pPage->apOvfl[j] = pCell;

  69942.     pPage->aiOvfl[j] = (u16)i;

  69943. 

  69944.     /* When multiple overflows occur, they are always sequential and in

  69945.     ** sorted order.  This invariants arise because multiple overflows can

  69946.     ** only occur when inserting divider cells into the parent page during

  69947.     ** balancing, and the dividers are adjacent and sorted.

  69948.     */

  69949.     assert( j==0 || pPage->aiOvfl[j-1]<(u16)i ); /* Overflows in sorted order */

  69950.     assert( j==0 || i==pPage->aiOvfl[j-1]+1 );   /* Overflows are sequential */

  69951.   }else{

  69952.     int rc = sqlite3PagerWrite(pPage->pDbPage);

  69953.     if( rc!=SQLITE_OK ){

  69954.       *pRC = rc;

  69955.       return;

  69956.     }

  69957.     assert( sqlite3PagerIswriteable(pPage->pDbPage) );

  69958.     data = pPage->aData;

  69959.     assert( &data[pPage->cellOffset]==pPage->aCellIdx );

  69960.     rc = allocateSpace(pPage, sz, &idx);

  69961.     if( rc ){ *pRC = rc; return; }

  69962.     /* The allocateSpace() routine guarantees the following properties

  69963.     ** if it returns successfully */

  69964.     assert( idx >= 0 );

  69965.     assert( idx >= pPage->cellOffset+2*pPage->nCell+2 || CORRUPT_DB );

  69966.     assert( idx+sz <= (int)pPage->pBt->usableSize );

  69967.     pPage->nFree -= (u16)(2 + sz);

  69968.     if( iChild ){

  69969.       /* In a corrupt database where an entry in the cell index section of

  69970.       ** a btree page has a value of 3 or less, the pCell value might point

  69971.       ** as many as 4 bytes in front of the start of the aData buffer for

  69972.       ** the source page.  Make sure this does not cause problems by not

  69973.       ** reading the first 4 bytes */

  69974.       memcpy(&data[idx+4], pCell+4, sz-4);

  69975.       put4byte(&data[idx], iChild);

  69976.     }else{

  69977.       memcpy(&data[idx], pCell, sz);

  69978.     }

  69979.     pIns = pPage->aCellIdx + i*2;

  69980.     memmove(pIns+2, pIns, 2*(pPage->nCell - i));

  69981.     put2byte(pIns, idx);

  69982.     pPage->nCell++;

  69983.     /* increment the cell count */

  69984.     if( (++data[pPage->hdrOffset+4])==0 ) data[pPage->hdrOffset+3]++;

  69985.     assert( get2byte(&data[pPage->hdrOffset+3])==pPage->nCell || CORRUPT_DB );

  69986. #ifndef SQLITE_OMIT_AUTOVACUUM

  69987.     if( pPage->pBt->autoVacuum ){

  69988.       /* The cell may contain a pointer to an overflow page. If so, write

  69989.       ** the entry for the overflow page into the pointer map.

  69990.       */

  69991.       ptrmapPutOvflPtr(pPage, pPage, pCell, pRC);

  69992.     }

  69993. #endif

  69994.   }

  69995. }

  69996. 

  69997. /*

  69998. ** The following parameters determine how many adjacent pages get involved

  69999. ** in a balancing operation.  NN is the number of neighbors on either side

  70000. ** of the page that participate in the balancing operation.  NB is the

  70001. ** total number of pages that participate, including the target page and

  70002. ** NN neighbors on either side.

  70003. **

  70004. ** The minimum value of NN is 1 (of course).  Increasing NN above 1

  70005. ** (to 2 or 3) gives a modest improvement in SELECT and DELETE performance

  70006. ** in exchange for a larger degradation in INSERT and UPDATE performance.

  70007. ** The value of NN appears to give the best results overall.

  70008. **

  70009. ** (Later:) The description above makes it seem as if these values are

  70010. ** tunable - as if you could change them and recompile and it would all work.

  70011. ** But that is unlikely.  NB has been 3 since the inception of SQLite and

  70012. ** we have never tested any other value.

  70013. */

  70014. #define NN 1             /* Number of neighbors on either side of pPage */

  70015. #define NB 3             /* (NN*2+1): Total pages involved in the balance */

  70016. 

  70017. /*

  70018. ** A CellArray object contains a cache of pointers and sizes for a

  70019. ** consecutive sequence of cells that might be held on multiple pages.

  70020. **

  70021. ** The cells in this array are the divider cell or cells from the pParent

  70022. ** page plus up to three child pages.  There are a total of nCell cells.

  70023. **

  70024. ** pRef is a pointer to one of the pages that contributes cells.  This is

  70025. ** used to access information such as MemPage.intKey and MemPage.pBt->pageSize

  70026. ** which should be common to all pages that contribute cells to this array.

  70027. **

  70028. ** apCell[] and szCell[] hold, respectively, pointers to the start of each

  70029. ** cell and the size of each cell.  Some of the apCell[] pointers might refer

  70030. ** to overflow cells.  In other words, some apCel[] pointers might not point

  70031. ** to content area of the pages.

  70032. **

  70033. ** A szCell[] of zero means the size of that cell has not yet been computed.

  70034. **

  70035. ** The cells come from as many as four different pages:

  70036. **

  70037. **             -----------

  70038. **             | Parent  |

  70039. **             -----------

  70040. **            /     |     \

  70041. **           /      |      \

  70042. **  ---------   ---------   ---------

  70043. **  |Child-1|   |Child-2|   |Child-3|

  70044. **  ---------   ---------   ---------

  70045. **

  70046. ** The order of cells is in the array is for an index btree is:

  70047. **

  70048. **       1.  All cells from Child-1 in order

  70049. **       2.  The first divider cell from Parent

  70050. **       3.  All cells from Child-2 in order

  70051. **       4.  The second divider cell from Parent

  70052. **       5.  All cells from Child-3 in order

  70053. **

  70054. ** For a table-btree (with rowids) the items 2 and 4 are empty because

  70055. ** content exists only in leaves and there are no divider cells.

  70056. **

  70057. ** For an index btree, the apEnd[] array holds pointer to the end of page

  70058. ** for Child-1, the Parent, Child-2, the Parent (again), and Child-3,

  70059. ** respectively. The ixNx[] array holds the number of cells contained in

  70060. ** each of these 5 stages, and all stages to the left.  Hence:

  70061. **

  70062. **    ixNx[0] = Number of cells in Child-1.

  70063. **    ixNx[1] = Number of cells in Child-1 plus 1 for first divider.

  70064. **    ixNx[2] = Number of cells in Child-1 and Child-2 + 1 for 1st divider.

  70065. **    ixNx[3] = Number of cells in Child-1 and Child-2 + both divider cells

  70066. **    ixNx[4] = Total number of cells.

  70067. **

  70068. ** For a table-btree, the concept is similar, except only apEnd[0]..apEnd[2]

  70069. ** are used and they point to the leaf pages only, and the ixNx value are:

  70070. **

  70071. **    ixNx[0] = Number of cells in Child-1.

  70072. **    ixNx[1] = Number of cells in Child-1 and Child-2.

  70073. **    ixNx[2] = Total number of cells.

  70074. **

  70075. ** Sometimes when deleting, a child page can have zero cells.  In those

  70076. ** cases, ixNx[] entries with higher indexes, and the corresponding apEnd[]

  70077. ** entries, shift down.  The end result is that each ixNx[] entry should

  70078. ** be larger than the previous

  70079. */

  70080. typedef struct CellArray CellArray;

  70081. struct CellArray {

  70082.   int nCell;              /* Number of cells in apCell[] */

  70083.   MemPage *pRef;          /* Reference page */

  70084.   u8 **apCell;            /* All cells begin balanced */

  70085.   u16 *szCell;            /* Local size of all cells in apCell[] */

  70086.   u8 *apEnd[NB*2];        /* MemPage.aDataEnd values */

  70087.   int ixNx[NB*2];         /* Index of at which we move to the next apEnd[] */

  70088. };

  70089. 

  70090. /*

  70091. ** Make sure the cell sizes at idx, idx+1, ..., idx+N-1 have been

  70092. ** computed.

  70093. */

  70094. static void populateCellCache(CellArray *p, int idx, int N){

  70095.   assert( idx>=0 && idx+N<=p->nCell );

  70096.   while( N>0 ){

  70097.     assert( p->apCell[idx]!=0 );

  70098.     if( p->szCell[idx]==0 ){

  70099.       p->szCell[idx] = p->pRef->xCellSize(p->pRef, p->apCell[idx]);

  70100.     }else{

  70101.       assert( CORRUPT_DB ||

  70102.               p->szCell[idx]==p->pRef->xCellSize(p->pRef, p->apCell[idx]) );

  70103.     }

  70104.     idx++;

  70105.     N--;

  70106.   }

  70107. }

  70108. 

  70109. /*

  70110. ** Return the size of the Nth element of the cell array

  70111. */

  70112. static SQLITE_NOINLINE u16 computeCellSize(CellArray *p, int N){

  70113.   assert( N>=0 && N<p->nCell );

  70114.   assert( p->szCell[N]==0 );

  70115.   p->szCell[N] = p->pRef->xCellSize(p->pRef, p->apCell[N]);

  70116.   return p->szCell[N];

  70117. }

  70118. static u16 cachedCellSize(CellArray *p, int N){

  70119.   assert( N>=0 && N<p->nCell );

  70120.   if( p->szCell[N] ) return p->szCell[N];

  70121.   return computeCellSize(p, N);

  70122. }

  70123. 

  70124. /*

  70125. ** Array apCell[] contains pointers to nCell b-tree page cells. The 

  70126. ** szCell[] array contains the size in bytes of each cell. This function

  70127. ** replaces the current contents of page pPg with the contents of the cell

  70128. ** array.

  70129. **

  70130. ** Some of the cells in apCell[] may currently be stored in pPg. This

  70131. ** function works around problems caused by this by making a copy of any 

  70132. ** such cells before overwriting the page data.

  70133. **

  70134. ** The MemPage.nFree field is invalidated by this function. It is the 

  70135. ** responsibility of the caller to set it correctly.

  70136. */

  70137. static int rebuildPage(

  70138.   CellArray *pCArray,             /* Content to be added to page pPg */

  70139.   int iFirst,                     /* First cell in pCArray to use */

  70140.   int nCell,                      /* Final number of cells on page */

  70141.   MemPage *pPg                    /* The page to be reconstructed */

  70142. ){

  70143.   const int hdr = pPg->hdrOffset;          /* Offset of header on pPg */

  70144.   u8 * const aData = pPg->aData;           /* Pointer to data for pPg */

  70145.   const int usableSize = pPg->pBt->usableSize;

  70146.   u8 * const pEnd = &aData[usableSize];

  70147.   int i = iFirst;                 /* Which cell to copy from pCArray*/

  70148.   u32 j;                          /* Start of cell content area */

  70149.   int iEnd = i+nCell;             /* Loop terminator */

  70150.   u8 *pCellptr = pPg->aCellIdx;

  70151.   u8 *pTmp = sqlite3PagerTempSpace(pPg->pBt->pPager);

  70152.   u8 *pData;

  70153.   int k;                          /* Current slot in pCArray->apEnd[] */

  70154.   u8 *pSrcEnd;                    /* Current pCArray->apEnd[k] value */

  70155. 

  70156.   assert( i<iEnd );

  70157.   j = get2byte(&aData[hdr+5]);

  70158.   if( NEVER(j>(u32)usableSize) ){ j = 0; }

  70159.   memcpy(&pTmp[j], &aData[j], usableSize - j);

  70160. 

  70161.   for(k=0; pCArray->ixNx[k]<=i && ALWAYS(k<NB*2); k++){}

  70162.   pSrcEnd = pCArray->apEnd[k];

  70163. 

  70164.   pData = pEnd;

  70165.   while( 1/*exit by break*/ ){

  70166.     u8 *pCell = pCArray->apCell[i];

  70167.     u16 sz = pCArray->szCell[i];

  70168.     assert( sz>0 );

  70169.     if( SQLITE_WITHIN(pCell,aData,pEnd) ){

  70170.       if( ((uptr)(pCell+sz))>(uptr)pEnd ) return SQLITE_CORRUPT_BKPT;

  70171.       pCell = &pTmp[pCell - aData];

  70172.     }else if( (uptr)(pCell+sz)>(uptr)pSrcEnd

  70173.            && (uptr)(pCell)<(uptr)pSrcEnd

  70174.     ){

  70175.       return SQLITE_CORRUPT_BKPT;

  70176.     }

  70177. 

  70178.     pData -= sz;

  70179.     put2byte(pCellptr, (pData - aData));

  70180.     pCellptr += 2;

  70181.     if( pData < pCellptr ) return SQLITE_CORRUPT_BKPT;

  70182.     memcpy(pData, pCell, sz);

  70183.     assert( sz==pPg->xCellSize(pPg, pCell) || CORRUPT_DB );

  70184.     testcase( sz!=pPg->xCellSize(pPg,pCell) );

  70185.     i++;

  70186.     if( i>=iEnd ) break;

  70187.     if( pCArray->ixNx[k]<=i ){

  70188.       k++;

  70189.       pSrcEnd = pCArray->apEnd[k];

  70190.     }

  70191.   }

  70192. 

  70193.   /* The pPg->nFree field is now set incorrectly. The caller will fix it. */

  70194.   pPg->nCell = nCell;

  70195.   pPg->nOverflow = 0;

  70196. 

  70197.   put2byte(&aData[hdr+1], 0);

  70198.   put2byte(&aData[hdr+3], pPg->nCell);

  70199.   put2byte(&aData[hdr+5], pData - aData);

  70200.   aData[hdr+7] = 0x00;

  70201.   return SQLITE_OK;

  70202. }

  70203. 

  70204. /*

  70205. ** The pCArray objects contains pointers to b-tree cells and the cell sizes.

  70206. ** This function attempts to add the cells stored in the array to page pPg.

  70207. ** If it cannot (because the page needs to be defragmented before the cells

  70208. ** will fit), non-zero is returned. Otherwise, if the cells are added

  70209. ** successfully, zero is returned.

  70210. **

  70211. ** Argument pCellptr points to the first entry in the cell-pointer array

  70212. ** (part of page pPg) to populate. After cell apCell[0] is written to the

  70213. ** page body, a 16-bit offset is written to pCellptr. And so on, for each

  70214. ** cell in the array. It is the responsibility of the caller to ensure

  70215. ** that it is safe to overwrite this part of the cell-pointer array.

  70216. **

  70217. ** When this function is called, *ppData points to the start of the 

  70218. ** content area on page pPg. If the size of the content area is extended,

  70219. ** *ppData is updated to point to the new start of the content area

  70220. ** before returning.

  70221. **

  70222. ** Finally, argument pBegin points to the byte immediately following the

  70223. ** end of the space required by this page for the cell-pointer area (for

  70224. ** all cells - not just those inserted by the current call). If the content

  70225. ** area must be extended to before this point in order to accomodate all

  70226. ** cells in apCell[], then the cells do not fit and non-zero is returned.

  70227. */

  70228. static int pageInsertArray(

  70229.   MemPage *pPg,                   /* Page to add cells to */

  70230.   u8 *pBegin,                     /* End of cell-pointer array */

  70231.   u8 **ppData,                    /* IN/OUT: Page content-area pointer */

  70232.   u8 *pCellptr,                   /* Pointer to cell-pointer area */

  70233.   int iFirst,                     /* Index of first cell to add */

  70234.   int nCell,                      /* Number of cells to add to pPg */

  70235.   CellArray *pCArray              /* Array of cells */

  70236. ){

  70237.   int i = iFirst;                 /* Loop counter - cell index to insert */

  70238.   u8 *aData = pPg->aData;         /* Complete page */

  70239.   u8 *pData = *ppData;            /* Content area.  A subset of aData[] */

  70240.   int iEnd = iFirst + nCell;      /* End of loop. One past last cell to ins */

  70241.   int k;                          /* Current slot in pCArray->apEnd[] */

  70242.   u8 *pEnd;                       /* Maximum extent of cell data */

  70243.   assert( CORRUPT_DB || pPg->hdrOffset==0 );    /* Never called on page 1 */

  70244.   if( iEnd<=iFirst ) return 0;

  70245.   for(k=0; pCArray->ixNx[k]<=i && ALWAYS(k<NB*2); k++){}

  70246.   pEnd = pCArray->apEnd[k];

  70247.   while( 1 /*Exit by break*/ ){

  70248.     int sz, rc;

  70249.     u8 *pSlot;

  70250.     sz = cachedCellSize(pCArray, i);

  70251.     if( (aData[1]==0 && aData[2]==0) || (pSlot = pageFindSlot(pPg,sz,&rc))==0 ){

  70252.       if( (pData - pBegin)<sz ) return 1;

  70253.       pData -= sz;

  70254.       pSlot = pData;

  70255.     }

  70256.     /* pSlot and pCArray->apCell[i] will never overlap on a well-formed

  70257.     ** database.  But they might for a corrupt database.  Hence use memmove()

  70258.     ** since memcpy() sends SIGABORT with overlapping buffers on OpenBSD */

  70259.     assert( (pSlot+sz)<=pCArray->apCell[i]

  70260.          || pSlot>=(pCArray->apCell[i]+sz)

  70261.          || CORRUPT_DB );

  70262.     if( (uptr)(pCArray->apCell[i]+sz)>(uptr)pEnd

  70263.      && (uptr)(pCArray->apCell[i])<(uptr)pEnd

  70264.     ){

  70265.       assert( CORRUPT_DB );

  70266.       (void)SQLITE_CORRUPT_BKPT;

  70267.       return 1;

  70268.     }

  70269.     memmove(pSlot, pCArray->apCell[i], sz);

  70270.     put2byte(pCellptr, (pSlot - aData));

  70271.     pCellptr += 2;

  70272.     i++;

  70273.     if( i>=iEnd ) break;

  70274.     if( pCArray->ixNx[k]<=i ){

  70275.       k++;

  70276.       pEnd = pCArray->apEnd[k];

  70277.     }

  70278.   }

  70279.   *ppData = pData;

  70280.   return 0;

  70281. }

  70282. 

  70283. /*

  70284. ** The pCArray object contains pointers to b-tree cells and their sizes.

  70285. **

  70286. ** This function adds the space associated with each cell in the array

  70287. ** that is currently stored within the body of pPg to the pPg free-list.

  70288. ** The cell-pointers and other fields of the page are not updated.

  70289. **

  70290. ** This function returns the total number of cells added to the free-list.

  70291. */

  70292. static int pageFreeArray(

  70293.   MemPage *pPg,                   /* Page to edit */

  70294.   int iFirst,                     /* First cell to delete */

  70295.   int nCell,                      /* Cells to delete */

  70296.   CellArray *pCArray              /* Array of cells */

  70297. ){

  70298.   u8 * const aData = pPg->aData;

  70299.   u8 * const pEnd = &aData[pPg->pBt->usableSize];

  70300.   u8 * const pStart = &aData[pPg->hdrOffset + 8 + pPg->childPtrSize];

  70301.   int nRet = 0;

  70302.   int i;

  70303.   int iEnd = iFirst + nCell;

  70304.   u8 *pFree = 0;

  70305.   int szFree = 0;

  70306. 

  70307.   for(i=iFirst; i<iEnd; i++){

  70308.     u8 *pCell = pCArray->apCell[i];

  70309.     if( SQLITE_WITHIN(pCell, pStart, pEnd) ){

  70310.       int sz;

  70311.       /* No need to use cachedCellSize() here.  The sizes of all cells that

  70312.       ** are to be freed have already been computing while deciding which

  70313.       ** cells need freeing */

  70314.       sz = pCArray->szCell[i];  assert( sz>0 );

  70315.       if( pFree!=(pCell + sz) ){

  70316.         if( pFree ){

  70317.           assert( pFree>aData && (pFree - aData)<65536 );

  70318.           freeSpace(pPg, (u16)(pFree - aData), szFree);

  70319.         }

  70320.         pFree = pCell;

  70321.         szFree = sz;

  70322.         if( pFree+sz>pEnd ) return 0;

  70323.       }else{

  70324.         pFree = pCell;

  70325.         szFree += sz;

  70326.       }

  70327.       nRet++;

  70328.     }

  70329.   }

  70330.   if( pFree ){

  70331.     assert( pFree>aData && (pFree - aData)<65536 );

  70332.     freeSpace(pPg, (u16)(pFree - aData), szFree);

  70333.   }

  70334.   return nRet;

  70335. }

  70336. 

  70337. /*

  70338. ** pCArray contains pointers to and sizes of all cells in the page being

  70339. ** balanced.  The current page, pPg, has pPg->nCell cells starting with

  70340. ** pCArray->apCell[iOld].  After balancing, this page should hold nNew cells

  70341. ** starting at apCell[iNew].

  70342. **

  70343. ** This routine makes the necessary adjustments to pPg so that it contains

  70344. ** the correct cells after being balanced.

  70345. **

  70346. ** The pPg->nFree field is invalid when this function returns. It is the

  70347. ** responsibility of the caller to set it correctly.

  70348. */

  70349. static int editPage(

  70350.   MemPage *pPg,                   /* Edit this page */

  70351.   int iOld,                       /* Index of first cell currently on page */

  70352.   int iNew,                       /* Index of new first cell on page */

  70353.   int nNew,                       /* Final number of cells on page */

  70354.   CellArray *pCArray              /* Array of cells and sizes */

  70355. ){

  70356.   u8 * const aData = pPg->aData;

  70357.   const int hdr = pPg->hdrOffset;

  70358.   u8 *pBegin = &pPg->aCellIdx[nNew * 2];

  70359.   int nCell = pPg->nCell;       /* Cells stored on pPg */

  70360.   u8 *pData;

  70361.   u8 *pCellptr;

  70362.   int i;

  70363.   int iOldEnd = iOld + pPg->nCell + pPg->nOverflow;

  70364.   int iNewEnd = iNew + nNew;

  70365. 

  70366. #ifdef SQLITE_DEBUG

  70367.   u8 *pTmp = sqlite3PagerTempSpace(pPg->pBt->pPager);

  70368.   memcpy(pTmp, aData, pPg->pBt->usableSize);

  70369. #endif

  70370. 

  70371.   /* Remove cells from the start and end of the page */

  70372.   assert( nCell>=0 );

  70373.   if( iOld<iNew ){

  70374.     int nShift = pageFreeArray(pPg, iOld, iNew-iOld, pCArray);

  70375.     if( nShift>nCell ) return SQLITE_CORRUPT_BKPT;

  70376.     memmove(pPg->aCellIdx, &pPg->aCellIdx[nShift*2], nCell*2);

  70377.     nCell -= nShift;

  70378.   }

  70379.   if( iNewEnd < iOldEnd ){

  70380.     int nTail = pageFreeArray(pPg, iNewEnd, iOldEnd - iNewEnd, pCArray);

  70381.     assert( nCell>=nTail );

  70382.     nCell -= nTail;

  70383.   }

  70384. 

  70385.   pData = &aData[get2byteNotZero(&aData[hdr+5])];

  70386.   if( pData<pBegin ) goto editpage_fail;

  70387. 

  70388.   /* Add cells to the start of the page */

  70389.   if( iNew<iOld ){

  70390.     int nAdd = MIN(nNew,iOld-iNew);

  70391.     assert( (iOld-iNew)<nNew || nCell==0 || CORRUPT_DB );

  70392.     assert( nAdd>=0 );

  70393.     pCellptr = pPg->aCellIdx;

  70394.     memmove(&pCellptr[nAdd*2], pCellptr, nCell*2);

  70395.     if( pageInsertArray(

  70396.           pPg, pBegin, &pData, pCellptr,

  70397.           iNew, nAdd, pCArray

  70398.     ) ) goto editpage_fail;

  70399.     nCell += nAdd;

  70400.   }

  70401. 

  70402.   /* Add any overflow cells */

  70403.   for(i=0; i<pPg->nOverflow; i++){

  70404.     int iCell = (iOld + pPg->aiOvfl[i]) - iNew;

  70405.     if( iCell>=0 && iCell<nNew ){

  70406.       pCellptr = &pPg->aCellIdx[iCell * 2];

  70407.       if( nCell>iCell ){

  70408.         memmove(&pCellptr[2], pCellptr, (nCell - iCell) * 2);

  70409.       }

  70410.       nCell++;

  70411.       if( pageInsertArray(

  70412.             pPg, pBegin, &pData, pCellptr,

  70413.             iCell+iNew, 1, pCArray

  70414.       ) ) goto editpage_fail;

  70415.     }

  70416.   }

  70417. 

  70418.   /* Append cells to the end of the page */

  70419.   assert( nCell>=0 );

  70420.   pCellptr = &pPg->aCellIdx[nCell*2];

  70421.   if( pageInsertArray(

  70422.         pPg, pBegin, &pData, pCellptr,

  70423.         iNew+nCell, nNew-nCell, pCArray

  70424.   ) ) goto editpage_fail;

  70425. 

  70426.   pPg->nCell = nNew;

  70427.   pPg->nOverflow = 0;

  70428. 

  70429.   put2byte(&aData[hdr+3], pPg->nCell);

  70430.   put2byte(&aData[hdr+5], pData - aData);

  70431. 

  70432. #ifdef SQLITE_DEBUG

  70433.   for(i=0; i<nNew && !CORRUPT_DB; i++){

  70434.     u8 *pCell = pCArray->apCell[i+iNew];

  70435.     int iOff = get2byteAligned(&pPg->aCellIdx[i*2]);

  70436.     if( SQLITE_WITHIN(pCell, aData, &aData[pPg->pBt->usableSize]) ){

  70437.       pCell = &pTmp[pCell - aData];

  70438.     }

  70439.     assert( 0==memcmp(pCell, &aData[iOff],

  70440.             pCArray->pRef->xCellSize(pCArray->pRef, pCArray->apCell[i+iNew])) );

  70441.   }

  70442. #endif

  70443. 

  70444.   return SQLITE_OK;

  70445.  editpage_fail:

  70446.   /* Unable to edit this page. Rebuild it from scratch instead. */

  70447.   populateCellCache(pCArray, iNew, nNew);

  70448.   return rebuildPage(pCArray, iNew, nNew, pPg);

  70449. }

  70450. 

  70451. 

  70452. #ifndef SQLITE_OMIT_QUICKBALANCE

  70453. /*

  70454. ** This version of balance() handles the common special case where

  70455. ** a new entry is being inserted on the extreme right-end of the

  70456. ** tree, in other words, when the new entry will become the largest

  70457. ** entry in the tree.

  70458. **

  70459. ** Instead of trying to balance the 3 right-most leaf pages, just add

  70460. ** a new page to the right-hand side and put the one new entry in

  70461. ** that page.  This leaves the right side of the tree somewhat

  70462. ** unbalanced.  But odds are that we will be inserting new entries

  70463. ** at the end soon afterwards so the nearly empty page will quickly

  70464. ** fill up.  On average.

  70465. **

  70466. ** pPage is the leaf page which is the right-most page in the tree.

  70467. ** pParent is its parent.  pPage must have a single overflow entry

  70468. ** which is also the right-most entry on the page.

  70469. **

  70470. ** The pSpace buffer is used to store a temporary copy of the divider

  70471. ** cell that will be inserted into pParent. Such a cell consists of a 4

  70472. ** byte page number followed by a variable length integer. In other

  70473. ** words, at most 13 bytes. Hence the pSpace buffer must be at

  70474. ** least 13 bytes in size.

  70475. */

  70476. static int balance_quick(MemPage *pParent, MemPage *pPage, u8 *pSpace){

  70477.   BtShared *const pBt = pPage->pBt;    /* B-Tree Database */

  70478.   MemPage *pNew;                       /* Newly allocated page */

  70479.   int rc;                              /* Return Code */

  70480.   Pgno pgnoNew;                        /* Page number of pNew */

  70481. 

  70482.   assert( sqlite3_mutex_held(pPage->pBt->mutex) );

  70483.   assert( sqlite3PagerIswriteable(pParent->pDbPage) );

  70484.   assert( pPage->nOverflow==1 );

  70485.   

  70486.   if( pPage->nCell==0 ) return SQLITE_CORRUPT_BKPT;  /* dbfuzz001.test */

  70487.   assert( pPage->nFree>=0 );

  70488.   assert( pParent->nFree>=0 );

  70489. 

  70490.   /* Allocate a new page. This page will become the right-sibling of 

  70491.   ** pPage. Make the parent page writable, so that the new divider cell

  70492.   ** may be inserted. If both these operations are successful, proceed.

  70493.   */

  70494.   rc = allocateBtreePage(pBt, &pNew, &pgnoNew, 0, 0);

  70495. 

  70496.   if( rc==SQLITE_OK ){

  70497. 

  70498.     u8 *pOut = &pSpace[4];

  70499.     u8 *pCell = pPage->apOvfl[0];

  70500.     u16 szCell = pPage->xCellSize(pPage, pCell);

  70501.     u8 *pStop;

  70502.     CellArray b;

  70503. 

  70504.     assert( sqlite3PagerIswriteable(pNew->pDbPage) );

  70505.     assert( CORRUPT_DB || pPage->aData[0]==(PTF_INTKEY|PTF_LEAFDATA|PTF_LEAF) );

  70506.     zeroPage(pNew, PTF_INTKEY|PTF_LEAFDATA|PTF_LEAF);

  70507.     b.nCell = 1;

  70508.     b.pRef = pPage;

  70509.     b.apCell = &pCell;

  70510.     b.szCell = &szCell;

  70511.     b.apEnd[0] = pPage->aDataEnd;

  70512.     b.ixNx[0] = 2;

  70513.     rc = rebuildPage(&b, 0, 1, pNew);

  70514.     if( NEVER(rc) ){

  70515.       releasePage(pNew);

  70516.       return rc;

  70517.     }

  70518.     pNew->nFree = pBt->usableSize - pNew->cellOffset - 2 - szCell;

  70519. 

  70520.     /* If this is an auto-vacuum database, update the pointer map

  70521.     ** with entries for the new page, and any pointer from the 

  70522.     ** cell on the page to an overflow page. If either of these

  70523.     ** operations fails, the return code is set, but the contents

  70524.     ** of the parent page are still manipulated by thh code below.

  70525.     ** That is Ok, at this point the parent page is guaranteed to

  70526.     ** be marked as dirty. Returning an error code will cause a

  70527.     ** rollback, undoing any changes made to the parent page.

  70528.     */

  70529.     if( ISAUTOVACUUM ){

  70530.       ptrmapPut(pBt, pgnoNew, PTRMAP_BTREE, pParent->pgno, &rc);

  70531.       if( szCell>pNew->minLocal ){

  70532.         ptrmapPutOvflPtr(pNew, pNew, pCell, &rc);

  70533.       }

  70534.     }

  70535.   

  70536.     /* Create a divider cell to insert into pParent. The divider cell

  70537.     ** consists of a 4-byte page number (the page number of pPage) and

  70538.     ** a variable length key value (which must be the same value as the

  70539.     ** largest key on pPage).

  70540.     **

  70541.     ** To find the largest key value on pPage, first find the right-most 

  70542.     ** cell on pPage. The first two fields of this cell are the 

  70543.     ** record-length (a variable length integer at most 32-bits in size)

  70544.     ** and the key value (a variable length integer, may have any value).

  70545.     ** The first of the while(...) loops below skips over the record-length

  70546.     ** field. The second while(...) loop copies the key value from the

  70547.     ** cell on pPage into the pSpace buffer.

  70548.     */

  70549.     pCell = findCell(pPage, pPage->nCell-1);

  70550.     pStop = &pCell[9];

  70551.     while( (*(pCell++)&0x80) && pCell<pStop );

  70552.     pStop = &pCell[9];

  70553.     while( ((*(pOut++) = *(pCell++))&0x80) && pCell<pStop );

  70554. 

  70555.     /* Insert the new divider cell into pParent. */

  70556.     if( rc==SQLITE_OK ){

  70557.       insertCell(pParent, pParent->nCell, pSpace, (int)(pOut-pSpace),

  70558.                    0, pPage->pgno, &rc);

  70559.     }

  70560. 

  70561.     /* Set the right-child pointer of pParent to point to the new page. */

  70562.     put4byte(&pParent->aData[pParent->hdrOffset+8], pgnoNew);

  70563.   

  70564.     /* Release the reference to the new page. */

  70565.     releasePage(pNew);

  70566.   }

  70567. 

  70568.   return rc;

  70569. }

  70570. #endif /* SQLITE_OMIT_QUICKBALANCE */

  70571. 

  70572. #if 0

  70573. /*

  70574. ** This function does not contribute anything to the operation of SQLite.

  70575. ** it is sometimes activated temporarily while debugging code responsible 

  70576. ** for setting pointer-map entries.

  70577. */

  70578. static int ptrmapCheckPages(MemPage **apPage, int nPage){

  70579.   int i, j;

  70580.   for(i=0; i<nPage; i++){

  70581.     Pgno n;

  70582.     u8 e;

  70583.     MemPage *pPage = apPage[i];

  70584.     BtShared *pBt = pPage->pBt;

  70585.     assert( pPage->isInit );

  70586. 

  70587.     for(j=0; j<pPage->nCell; j++){

  70588.       CellInfo info;

  70589.       u8 *z;

  70590.      

  70591.       z = findCell(pPage, j);

  70592.       pPage->xParseCell(pPage, z, &info);

  70593.       if( info.nLocal<info.nPayload ){

  70594.         Pgno ovfl = get4byte(&z[info.nSize-4]);

  70595.         ptrmapGet(pBt, ovfl, &e, &n);

  70596.         assert( n==pPage->pgno && e==PTRMAP_OVERFLOW1 );

  70597.       }

  70598.       if( !pPage->leaf ){

  70599.         Pgno child = get4byte(z);

  70600.         ptrmapGet(pBt, child, &e, &n);

  70601.         assert( n==pPage->pgno && e==PTRMAP_BTREE );

  70602.       }

  70603.     }

  70604.     if( !pPage->leaf ){

  70605.       Pgno child = get4byte(&pPage->aData[pPage->hdrOffset+8]);

  70606.       ptrmapGet(pBt, child, &e, &n);

  70607.       assert( n==pPage->pgno && e==PTRMAP_BTREE );

  70608.     }

  70609.   }

  70610.   return 1;

  70611. }

  70612. #endif

  70613. 

  70614. /*

  70615. ** This function is used to copy the contents of the b-tree node stored 

  70616. ** on page pFrom to page pTo. If page pFrom was not a leaf page, then

  70617. ** the pointer-map entries for each child page are updated so that the

  70618. ** parent page stored in the pointer map is page pTo. If pFrom contained

  70619. ** any cells with overflow page pointers, then the corresponding pointer

  70620. ** map entries are also updated so that the parent page is page pTo.

  70621. **

  70622. ** If pFrom is currently carrying any overflow cells (entries in the

  70623. ** MemPage.apOvfl[] array), they are not copied to pTo. 

  70624. **

  70625. ** Before returning, page pTo is reinitialized using btreeInitPage().

  70626. **

  70627. ** The performance of this function is not critical. It is only used by 

  70628. ** the balance_shallower() and balance_deeper() procedures, neither of

  70629. ** which are called often under normal circumstances.

  70630. */

  70631. static void copyNodeContent(MemPage *pFrom, MemPage *pTo, int *pRC){

  70632.   if( (*pRC)==SQLITE_OK ){

  70633.     BtShared * const pBt = pFrom->pBt;

  70634.     u8 * const aFrom = pFrom->aData;

  70635.     u8 * const aTo = pTo->aData;

  70636.     int const iFromHdr = pFrom->hdrOffset;

  70637.     int const iToHdr = ((pTo->pgno==1) ? 100 : 0);

  70638.     int rc;

  70639.     int iData;

  70640.   

  70641.   

  70642.     assert( pFrom->isInit );

  70643.     assert( pFrom->nFree>=iToHdr );

  70644.     assert( get2byte(&aFrom[iFromHdr+5]) <= (int)pBt->usableSize );

  70645.   

  70646.     /* Copy the b-tree node content from page pFrom to page pTo. */

  70647.     iData = get2byte(&aFrom[iFromHdr+5]);

  70648.     memcpy(&aTo[iData], &aFrom[iData], pBt->usableSize-iData);

  70649.     memcpy(&aTo[iToHdr], &aFrom[iFromHdr], pFrom->cellOffset + 2*pFrom->nCell);

  70650.   

  70651.     /* Reinitialize page pTo so that the contents of the MemPage structure

  70652.     ** match the new data. The initialization of pTo can actually fail under

  70653.     ** fairly obscure circumstances, even though it is a copy of initialized 

  70654.     ** page pFrom.

  70655.     */

  70656.     pTo->isInit = 0;

  70657.     rc = btreeInitPage(pTo);

  70658.     if( rc==SQLITE_OK ) rc = btreeComputeFreeSpace(pTo);

  70659.     if( rc!=SQLITE_OK ){

  70660.       *pRC = rc;

  70661.       return;

  70662.     }

  70663.   

  70664.     /* If this is an auto-vacuum database, update the pointer-map entries

  70665.     ** for any b-tree or overflow pages that pTo now contains the pointers to.

  70666.     */

  70667.     if( ISAUTOVACUUM ){

  70668.       *pRC = setChildPtrmaps(pTo);

  70669.     }

  70670.   }

  70671. }

  70672. 

  70673. /*

  70674. ** This routine redistributes cells on the iParentIdx'th child of pParent

  70675. ** (hereafter "the page") and up to 2 siblings so that all pages have about the

  70676. ** same amount of free space. Usually a single sibling on either side of the

  70677. ** page are used in the balancing, though both siblings might come from one

  70678. ** side if the page is the first or last child of its parent. If the page 

  70679. ** has fewer than 2 siblings (something which can only happen if the page

  70680. ** is a root page or a child of a root page) then all available siblings

  70681. ** participate in the balancing.

  70682. **

  70683. ** The number of siblings of the page might be increased or decreased by 

  70684. ** one or two in an effort to keep pages nearly full but not over full. 

  70685. **

  70686. ** Note that when this routine is called, some of the cells on the page

  70687. ** might not actually be stored in MemPage.aData[]. This can happen

  70688. ** if the page is overfull. This routine ensures that all cells allocated

  70689. ** to the page and its siblings fit into MemPage.aData[] before returning.

  70690. **

  70691. ** In the course of balancing the page and its siblings, cells may be

  70692. ** inserted into or removed from the parent page (pParent). Doing so

  70693. ** may cause the parent page to become overfull or underfull. If this

  70694. ** happens, it is the responsibility of the caller to invoke the correct

  70695. ** balancing routine to fix this problem (see the balance() routine). 

  70696. **

  70697. ** If this routine fails for any reason, it might leave the database

  70698. ** in a corrupted state. So if this routine fails, the database should

  70699. ** be rolled back.

  70700. **

  70701. ** The third argument to this function, aOvflSpace, is a pointer to a

  70702. ** buffer big enough to hold one page. If while inserting cells into the parent

  70703. ** page (pParent) the parent page becomes overfull, this buffer is

  70704. ** used to store the parent's overflow cells. Because this function inserts

  70705. ** a maximum of four divider cells into the parent page, and the maximum

  70706. ** size of a cell stored within an internal node is always less than 1/4

  70707. ** of the page-size, the aOvflSpace[] buffer is guaranteed to be large

  70708. ** enough for all overflow cells.

  70709. **

  70710. ** If aOvflSpace is set to a null pointer, this function returns 

  70711. ** SQLITE_NOMEM.

  70712. */

  70713. static int balance_nonroot(

  70714.   MemPage *pParent,               /* Parent page of siblings being balanced */

  70715.   int iParentIdx,                 /* Index of "the page" in pParent */

  70716.   u8 *aOvflSpace,                 /* page-size bytes of space for parent ovfl */

  70717.   int isRoot,                     /* True if pParent is a root-page */

  70718.   int bBulk                       /* True if this call is part of a bulk load */

  70719. ){

  70720.   BtShared *pBt;               /* The whole database */

  70721.   int nMaxCells = 0;           /* Allocated size of apCell, szCell, aFrom. */

  70722.   int nNew = 0;                /* Number of pages in apNew[] */

  70723.   int nOld;                    /* Number of pages in apOld[] */

  70724.   int i, j, k;                 /* Loop counters */

  70725.   int nxDiv;                   /* Next divider slot in pParent->aCell[] */

  70726.   int rc = SQLITE_OK;          /* The return code */

  70727.   u16 leafCorrection;          /* 4 if pPage is a leaf.  0 if not */

  70728.   int leafData;                /* True if pPage is a leaf of a LEAFDATA tree */

  70729.   int usableSpace;             /* Bytes in pPage beyond the header */

  70730.   int pageFlags;               /* Value of pPage->aData[0] */

  70731.   int iSpace1 = 0;             /* First unused byte of aSpace1[] */

  70732.   int iOvflSpace = 0;          /* First unused byte of aOvflSpace[] */

  70733.   int szScratch;               /* Size of scratch memory requested */

  70734.   MemPage *apOld[NB];          /* pPage and up to two siblings */

  70735.   MemPage *apNew[NB+2];        /* pPage and up to NB siblings after balancing */

  70736.   u8 *pRight;                  /* Location in parent of right-sibling pointer */

  70737.   u8 *apDiv[NB-1];             /* Divider cells in pParent */

  70738.   int cntNew[NB+2];            /* Index in b.paCell[] of cell after i-th page */

  70739.   int cntOld[NB+2];            /* Old index in b.apCell[] */

  70740.   int szNew[NB+2];             /* Combined size of cells placed on i-th page */

  70741.   u8 *aSpace1;                 /* Space for copies of dividers cells */

  70742.   Pgno pgno;                   /* Temp var to store a page number in */

  70743.   u8 abDone[NB+2];             /* True after i'th new page is populated */

  70744.   Pgno aPgno[NB+2];            /* Page numbers of new pages before shuffling */

  70745.   Pgno aPgOrder[NB+2];         /* Copy of aPgno[] used for sorting pages */

  70746.   u16 aPgFlags[NB+2];          /* flags field of new pages before shuffling */

  70747.   CellArray b;                  /* Parsed information on cells being balanced */

  70748. 

  70749.   memset(abDone, 0, sizeof(abDone));

  70750.   b.nCell = 0;

  70751.   b.apCell = 0;

  70752.   pBt = pParent->pBt;

  70753.   assert( sqlite3_mutex_held(pBt->mutex) );

  70754.   assert( sqlite3PagerIswriteable(pParent->pDbPage) );

  70755. 

  70756.   /* At this point pParent may have at most one overflow cell. And if

  70757.   ** this overflow cell is present, it must be the cell with 

  70758.   ** index iParentIdx. This scenario comes about when this function

  70759.   ** is called (indirectly) from sqlite3BtreeDelete().

  70760.   */

  70761.   assert( pParent->nOverflow==0 || pParent->nOverflow==1 );

  70762.   assert( pParent->nOverflow==0 || pParent->aiOvfl[0]==iParentIdx );

  70763. 

  70764.   if( !aOvflSpace ){

  70765.     return SQLITE_NOMEM_BKPT;

  70766.   }

  70767.   assert( pParent->nFree>=0 );

  70768. 

  70769.   /* Find the sibling pages to balance. Also locate the cells in pParent 

  70770.   ** that divide the siblings. An attempt is made to find NN siblings on 

  70771.   ** either side of pPage. More siblings are taken from one side, however, 

  70772.   ** if there are fewer than NN siblings on the other side. If pParent

  70773.   ** has NB or fewer children then all children of pParent are taken.  

  70774.   **

  70775.   ** This loop also drops the divider cells from the parent page. This

  70776.   ** way, the remainder of the function does not have to deal with any

  70777.   ** overflow cells in the parent page, since if any existed they will

  70778.   ** have already been removed.

  70779.   */

  70780.   i = pParent->nOverflow + pParent->nCell;

  70781.   if( i<2 ){

  70782.     nxDiv = 0;

  70783.   }else{

  70784.     assert( bBulk==0 || bBulk==1 );

  70785.     if( iParentIdx==0 ){                 

  70786.       nxDiv = 0;

  70787.     }else if( iParentIdx==i ){

  70788.       nxDiv = i-2+bBulk;

  70789.     }else{

  70790.       nxDiv = iParentIdx-1;

  70791.     }

  70792.     i = 2-bBulk;

  70793.   }

  70794.   nOld = i+1;

  70795.   if( (i+nxDiv-pParent->nOverflow)==pParent->nCell ){

  70796.     pRight = &pParent->aData[pParent->hdrOffset+8];

  70797.   }else{

  70798.     pRight = findCell(pParent, i+nxDiv-pParent->nOverflow);

  70799.   }

  70800.   pgno = get4byte(pRight);

  70801.   while( 1 ){

  70802.     rc = getAndInitPage(pBt, pgno, &apOld[i], 0, 0);

  70803.     if( rc ){

  70804.       memset(apOld, 0, (i+1)*sizeof(MemPage*));

  70805.       goto balance_cleanup;

  70806.     }

  70807.     if( apOld[i]->nFree<0 ){

  70808.       rc = btreeComputeFreeSpace(apOld[i]);

  70809.       if( rc ){

  70810.         memset(apOld, 0, (i)*sizeof(MemPage*));

  70811.         goto balance_cleanup;

  70812.       }

  70813.     }

  70814.     if( (i--)==0 ) break;

  70815. 

  70816.     if( pParent->nOverflow && i+nxDiv==pParent->aiOvfl[0] ){

  70817.       apDiv[i] = pParent->apOvfl[0];

  70818.       pgno = get4byte(apDiv[i]);

  70819.       szNew[i] = pParent->xCellSize(pParent, apDiv[i]);

  70820.       pParent->nOverflow = 0;

  70821.     }else{

  70822.       apDiv[i] = findCell(pParent, i+nxDiv-pParent->nOverflow);

  70823.       pgno = get4byte(apDiv[i]);

  70824.       szNew[i] = pParent->xCellSize(pParent, apDiv[i]);

  70825. 

  70826.       /* Drop the cell from the parent page. apDiv[i] still points to

  70827.       ** the cell within the parent, even though it has been dropped.

  70828.       ** This is safe because dropping a cell only overwrites the first

  70829.       ** four bytes of it, and this function does not need the first

  70830.       ** four bytes of the divider cell. So the pointer is safe to use

  70831.       ** later on.  

  70832.       **

  70833.       ** But not if we are in secure-delete mode. In secure-delete mode,

  70834.       ** the dropCell() routine will overwrite the entire cell with zeroes.

  70835.       ** In this case, temporarily copy the cell into the aOvflSpace[]

  70836.       ** buffer. It will be copied out again as soon as the aSpace[] buffer

  70837.       ** is allocated.  */

  70838.       if( pBt->btsFlags & BTS_FAST_SECURE ){

  70839.         int iOff;

  70840. 

  70841.         iOff = SQLITE_PTR_TO_INT(apDiv[i]) - SQLITE_PTR_TO_INT(pParent->aData);

  70842.         if( (iOff+szNew[i])>(int)pBt->usableSize ){

  70843.           rc = SQLITE_CORRUPT_BKPT;

  70844.           memset(apOld, 0, (i+1)*sizeof(MemPage*));

  70845.           goto balance_cleanup;

  70846.         }else{

  70847.           memcpy(&aOvflSpace[iOff], apDiv[i], szNew[i]);

  70848.           apDiv[i] = &aOvflSpace[apDiv[i]-pParent->aData];

  70849.         }

  70850.       }

  70851.       dropCell(pParent, i+nxDiv-pParent->nOverflow, szNew[i], &rc);

  70852.     }

  70853.   }

  70854. 

  70855.   /* Make nMaxCells a multiple of 4 in order to preserve 8-byte

  70856.   ** alignment */

  70857.   nMaxCells = nOld*(MX_CELL(pBt) + ArraySize(pParent->apOvfl));

  70858.   nMaxCells = (nMaxCells + 3)&~3;

  70859. 

  70860.   /*

  70861.   ** Allocate space for memory structures

  70862.   */

  70863.   szScratch =

  70864.        nMaxCells*sizeof(u8*)                       /* b.apCell */

  70865.      + nMaxCells*sizeof(u16)                       /* b.szCell */

  70866.      + pBt->pageSize;                              /* aSpace1 */

  70867. 

  70868.   assert( szScratch<=7*(int)pBt->pageSize );

  70869.   b.apCell = sqlite3StackAllocRaw(0, szScratch );

  70870.   if( b.apCell==0 ){

  70871.     rc = SQLITE_NOMEM_BKPT;

  70872.     goto balance_cleanup;

  70873.   }

  70874.   b.szCell = (u16*)&b.apCell[nMaxCells];

  70875.   aSpace1 = (u8*)&b.szCell[nMaxCells];

  70876.   assert( EIGHT_BYTE_ALIGNMENT(aSpace1) );

  70877. 

  70878.   /*

  70879.   ** Load pointers to all cells on sibling pages and the divider cells

  70880.   ** into the local b.apCell[] array.  Make copies of the divider cells

  70881.   ** into space obtained from aSpace1[]. The divider cells have already

  70882.   ** been removed from pParent.

  70883.   **

  70884.   ** If the siblings are on leaf pages, then the child pointers of the

  70885.   ** divider cells are stripped from the cells before they are copied

  70886.   ** into aSpace1[].  In this way, all cells in b.apCell[] are without

  70887.   ** child pointers.  If siblings are not leaves, then all cell in

  70888.   ** b.apCell[] include child pointers.  Either way, all cells in b.apCell[]

  70889.   ** are alike.

  70890.   **

  70891.   ** leafCorrection:  4 if pPage is a leaf.  0 if pPage is not a leaf.

  70892.   **       leafData:  1 if pPage holds key+data and pParent holds only keys.

  70893.   */

  70894.   b.pRef = apOld[0];

  70895.   leafCorrection = b.pRef->leaf*4;

  70896.   leafData = b.pRef->intKeyLeaf;

  70897.   for(i=0; i<nOld; i++){

  70898.     MemPage *pOld = apOld[i];

  70899.     int limit = pOld->nCell;

  70900.     u8 *aData = pOld->aData;

  70901.     u16 maskPage = pOld->maskPage;

  70902.     u8 *piCell = aData + pOld->cellOffset;

  70903.     u8 *piEnd;

  70904.     VVA_ONLY( int nCellAtStart = b.nCell; )

  70905. 

  70906.     /* Verify that all sibling pages are of the same "type" (table-leaf,

  70907.     ** table-interior, index-leaf, or index-interior).

  70908.     */

  70909.     if( pOld->aData[0]!=apOld[0]->aData[0] ){

  70910.       rc = SQLITE_CORRUPT_BKPT;

  70911.       goto balance_cleanup;

  70912.     }

  70913. 

  70914.     /* Load b.apCell[] with pointers to all cells in pOld.  If pOld

  70915.     ** contains overflow cells, include them in the b.apCell[] array

  70916.     ** in the correct spot.

  70917.     **

  70918.     ** Note that when there are multiple overflow cells, it is always the

  70919.     ** case that they are sequential and adjacent.  This invariant arises

  70920.     ** because multiple overflows can only occurs when inserting divider

  70921.     ** cells into a parent on a prior balance, and divider cells are always

  70922.     ** adjacent and are inserted in order.  There is an assert() tagged

  70923.     ** with "NOTE 1" in the overflow cell insertion loop to prove this

  70924.     ** invariant.

  70925.     **

  70926.     ** This must be done in advance.  Once the balance starts, the cell

  70927.     ** offset section of the btree page will be overwritten and we will no

  70928.     ** long be able to find the cells if a pointer to each cell is not saved

  70929.     ** first.

  70930.     */

  70931.     memset(&b.szCell[b.nCell], 0, sizeof(b.szCell[0])*(limit+pOld->nOverflow));

  70932.     if( pOld->nOverflow>0 ){

  70933.       if( limit<pOld->aiOvfl[0] ){

  70934.         rc = SQLITE_CORRUPT_BKPT;

  70935.         goto balance_cleanup;

  70936.       }

  70937.       limit = pOld->aiOvfl[0];

  70938.       for(j=0; j<limit; j++){

  70939.         b.apCell[b.nCell] = aData + (maskPage & get2byteAligned(piCell));

  70940.         piCell += 2;

  70941.         b.nCell++;

  70942.       }

  70943.       for(k=0; k<pOld->nOverflow; k++){

  70944.         assert( k==0 || pOld->aiOvfl[k-1]+1==pOld->aiOvfl[k] );/* NOTE 1 */

  70945.         b.apCell[b.nCell] = pOld->apOvfl[k];

  70946.         b.nCell++;

  70947.       }

  70948.     }

  70949.     piEnd = aData + pOld->cellOffset + 2*pOld->nCell;

  70950.     while( piCell<piEnd ){

  70951.       assert( b.nCell<nMaxCells );

  70952.       b.apCell[b.nCell] = aData + (maskPage & get2byteAligned(piCell));

  70953.       piCell += 2;

  70954.       b.nCell++;

  70955.     }

  70956.     assert( (b.nCell-nCellAtStart)==(pOld->nCell+pOld->nOverflow) );

  70957. 

  70958.     cntOld[i] = b.nCell;

  70959.     if( i<nOld-1 && !leafData){

  70960.       u16 sz = (u16)szNew[i];

  70961.       u8 *pTemp;

  70962.       assert( b.nCell<nMaxCells );

  70963.       b.szCell[b.nCell] = sz;

  70964.       pTemp = &aSpace1[iSpace1];

  70965.       iSpace1 += sz;

  70966.       assert( sz<=pBt->maxLocal+23 );

  70967.       assert( iSpace1 <= (int)pBt->pageSize );

  70968.       memcpy(pTemp, apDiv[i], sz);

  70969.       b.apCell[b.nCell] = pTemp+leafCorrection;

  70970.       assert( leafCorrection==0 || leafCorrection==4 );

  70971.       b.szCell[b.nCell] = b.szCell[b.nCell] - leafCorrection;

  70972.       if( !pOld->leaf ){

  70973.         assert( leafCorrection==0 );

  70974.         assert( pOld->hdrOffset==0 );

  70975.         /* The right pointer of the child page pOld becomes the left

  70976.         ** pointer of the divider cell */

  70977.         memcpy(b.apCell[b.nCell], &pOld->aData[8], 4);

  70978.       }else{

  70979.         assert( leafCorrection==4 );

  70980.         while( b.szCell[b.nCell]<4 ){

  70981.           /* Do not allow any cells smaller than 4 bytes. If a smaller cell

  70982.           ** does exist, pad it with 0x00 bytes. */

  70983.           assert( b.szCell[b.nCell]==3 || CORRUPT_DB );

  70984.           assert( b.apCell[b.nCell]==&aSpace1[iSpace1-3] || CORRUPT_DB );

  70985.           aSpace1[iSpace1++] = 0x00;

  70986.           b.szCell[b.nCell]++;

  70987.         }

  70988.       }

  70989.       b.nCell++;

  70990.     }

  70991.   }

  70992. 

  70993.   /*

  70994.   ** Figure out the number of pages needed to hold all b.nCell cells.

  70995.   ** Store this number in "k".  Also compute szNew[] which is the total

  70996.   ** size of all cells on the i-th page and cntNew[] which is the index

  70997.   ** in b.apCell[] of the cell that divides page i from page i+1.  

  70998.   ** cntNew[k] should equal b.nCell.

  70999.   **

  71000.   ** Values computed by this block:

  71001.   **

  71002.   **           k: The total number of sibling pages

  71003.   **    szNew[i]: Spaced used on the i-th sibling page.

  71004.   **   cntNew[i]: Index in b.apCell[] and b.szCell[] for the first cell to

  71005.   **              the right of the i-th sibling page.

  71006.   ** usableSpace: Number of bytes of space available on each sibling.

  71007.   ** 

  71008.   */

  71009.   usableSpace = pBt->usableSize - 12 + leafCorrection;

  71010.   for(i=k=0; i<nOld; i++, k++){

  71011.     MemPage *p = apOld[i];

  71012.     b.apEnd[k] = p->aDataEnd;

  71013.     b.ixNx[k] = cntOld[i];

  71014.     if( k && b.ixNx[k]==b.ixNx[k-1] ){

  71015.       k--;  /* Omit b.ixNx[] entry for child pages with no cells */

  71016.     }

  71017.     if( !leafData ){

  71018.       k++;

  71019.       b.apEnd[k] = pParent->aDataEnd;

  71020.       b.ixNx[k] = cntOld[i]+1;

  71021.     }

  71022.     assert( p->nFree>=0 );

  71023.     szNew[i] = usableSpace - p->nFree;

  71024.     for(j=0; j<p->nOverflow; j++){

  71025.       szNew[i] += 2 + p->xCellSize(p, p->apOvfl[j]);

  71026.     }

  71027.     cntNew[i] = cntOld[i];

  71028.   }

  71029.   k = nOld;

  71030.   for(i=0; i<k; i++){

  71031.     int sz;

  71032.     while( szNew[i]>usableSpace ){

  71033.       if( i+1>=k ){

  71034.         k = i+2;

  71035.         if( k>NB+2 ){ rc = SQLITE_CORRUPT_BKPT; goto balance_cleanup; }

  71036.         szNew[k-1] = 0;

  71037.         cntNew[k-1] = b.nCell;

  71038.       }

  71039.       sz = 2 + cachedCellSize(&b, cntNew[i]-1);

  71040.       szNew[i] -= sz;

  71041.       if( !leafData ){

  71042.         if( cntNew[i]<b.nCell ){

  71043.           sz = 2 + cachedCellSize(&b, cntNew[i]);

  71044.         }else{

  71045.           sz = 0;

  71046.         }

  71047.       }

  71048.       szNew[i+1] += sz;

  71049.       cntNew[i]--;

  71050.     }

  71051.     while( cntNew[i]<b.nCell ){

  71052.       sz = 2 + cachedCellSize(&b, cntNew[i]);

  71053.       if( szNew[i]+sz>usableSpace ) break;

  71054.       szNew[i] += sz;

  71055.       cntNew[i]++;

  71056.       if( !leafData ){

  71057.         if( cntNew[i]<b.nCell ){

  71058.           sz = 2 + cachedCellSize(&b, cntNew[i]);

  71059.         }else{

  71060.           sz = 0;

  71061.         }

  71062.       }

  71063.       szNew[i+1] -= sz;

  71064.     }

  71065.     if( cntNew[i]>=b.nCell ){

  71066.       k = i+1;

  71067.     }else if( cntNew[i] <= (i>0 ? cntNew[i-1] : 0) ){

  71068.       rc = SQLITE_CORRUPT_BKPT;

  71069.       goto balance_cleanup;

  71070.     }

  71071.   }

  71072. 

  71073.   /*

  71074.   ** The packing computed by the previous block is biased toward the siblings

  71075.   ** on the left side (siblings with smaller keys). The left siblings are

  71076.   ** always nearly full, while the right-most sibling might be nearly empty.

  71077.   ** The next block of code attempts to adjust the packing of siblings to

  71078.   ** get a better balance.

  71079.   **

  71080.   ** This adjustment is more than an optimization.  The packing above might

  71081.   ** be so out of balance as to be illegal.  For example, the right-most

  71082.   ** sibling might be completely empty.  This adjustment is not optional.

  71083.   */

  71084.   for(i=k-1; i>0; i--){

  71085.     int szRight = szNew[i];  /* Size of sibling on the right */

  71086.     int szLeft = szNew[i-1]; /* Size of sibling on the left */

  71087.     int r;              /* Index of right-most cell in left sibling */

  71088.     int d;              /* Index of first cell to the left of right sibling */

  71089. 

  71090.     r = cntNew[i-1] - 1;

  71091.     d = r + 1 - leafData;

  71092.     (void)cachedCellSize(&b, d);

  71093.     do{

  71094.       assert( d<nMaxCells );

  71095.       assert( r<nMaxCells );

  71096.       (void)cachedCellSize(&b, r);

  71097.       if( szRight!=0

  71098.        && (bBulk || szRight+b.szCell[d]+2 > szLeft-(b.szCell[r]+(i==k-1?0:2)))){

  71099.         break;

  71100.       }

  71101.       szRight += b.szCell[d] + 2;

  71102.       szLeft -= b.szCell[r] + 2;

  71103.       cntNew[i-1] = r;

  71104.       r--;

  71105.       d--;

  71106.     }while( r>=0 );

  71107.     szNew[i] = szRight;

  71108.     szNew[i-1] = szLeft;

  71109.     if( cntNew[i-1] <= (i>1 ? cntNew[i-2] : 0) ){

  71110.       rc = SQLITE_CORRUPT_BKPT;

  71111.       goto balance_cleanup;

  71112.     }

  71113.   }

  71114. 

  71115.   /* Sanity check:  For a non-corrupt database file one of the follwing

  71116.   ** must be true:

  71117.   **    (1) We found one or more cells (cntNew[0])>0), or

  71118.   **    (2) pPage is a virtual root page.  A virtual root page is when

  71119.   **        the real root page is page 1 and we are the only child of

  71120.   **        that page.

  71121.   */

  71122.   assert( cntNew[0]>0 || (pParent->pgno==1 && pParent->nCell==0) || CORRUPT_DB);

  71123.   TRACE(("BALANCE: old: %d(nc=%d) %d(nc=%d) %d(nc=%d)\n",

  71124.     apOld[0]->pgno, apOld[0]->nCell,

  71125.     nOld>=2 ? apOld[1]->pgno : 0, nOld>=2 ? apOld[1]->nCell : 0,

  71126.     nOld>=3 ? apOld[2]->pgno : 0, nOld>=3 ? apOld[2]->nCell : 0

  71127.   ));

  71128. 

  71129.   /*

  71130.   ** Allocate k new pages.  Reuse old pages where possible.

  71131.   */

  71132.   pageFlags = apOld[0]->aData[0];

  71133.   for(i=0; i<k; i++){

  71134.     MemPage *pNew;

  71135.     if( i<nOld ){

  71136.       pNew = apNew[i] = apOld[i];

  71137.       apOld[i] = 0;

  71138.       rc = sqlite3PagerWrite(pNew->pDbPage);

  71139.       nNew++;

  71140.       if( rc ) goto balance_cleanup;

  71141.     }else{

  71142.       assert( i>0 );

  71143.       rc = allocateBtreePage(pBt, &pNew, &pgno, (bBulk ? 1 : pgno), 0);

  71144.       if( rc ) goto balance_cleanup;

  71145.       zeroPage(pNew, pageFlags);

  71146.       apNew[i] = pNew;

  71147.       nNew++;

  71148.       cntOld[i] = b.nCell;

  71149. 

  71150.       /* Set the pointer-map entry for the new sibling page. */

  71151.       if( ISAUTOVACUUM ){

  71152.         ptrmapPut(pBt, pNew->pgno, PTRMAP_BTREE, pParent->pgno, &rc);

  71153.         if( rc!=SQLITE_OK ){

  71154.           goto balance_cleanup;

  71155.         }

  71156.       }

  71157.     }

  71158.   }

  71159. 

  71160.   /*

  71161.   ** Reassign page numbers so that the new pages are in ascending order. 

  71162.   ** This helps to keep entries in the disk file in order so that a scan

  71163.   ** of the table is closer to a linear scan through the file. That in turn 

  71164.   ** helps the operating system to deliver pages from the disk more rapidly.

  71165.   **

  71166.   ** An O(n^2) insertion sort algorithm is used, but since n is never more 

  71167.   ** than (NB+2) (a small constant), that should not be a problem.

  71168.   **

  71169.   ** When NB==3, this one optimization makes the database about 25% faster 

  71170.   ** for large insertions and deletions.

  71171.   */

  71172.   for(i=0; i<nNew; i++){

  71173.     aPgOrder[i] = aPgno[i] = apNew[i]->pgno;

  71174.     aPgFlags[i] = apNew[i]->pDbPage->flags;

  71175.     for(j=0; j<i; j++){

  71176.       if( aPgno[j]==aPgno[i] ){

  71177.         /* This branch is taken if the set of sibling pages somehow contains

  71178.         ** duplicate entries. This can happen if the database is corrupt. 

  71179.         ** It would be simpler to detect this as part of the loop below, but

  71180.         ** we do the detection here in order to avoid populating the pager

  71181.         ** cache with two separate objects associated with the same

  71182.         ** page number.  */

  71183.         assert( CORRUPT_DB );

  71184.         rc = SQLITE_CORRUPT_BKPT;

  71185.         goto balance_cleanup;

  71186.       }

  71187.     }

  71188.   }

  71189.   for(i=0; i<nNew; i++){

  71190.     int iBest = 0;                /* aPgno[] index of page number to use */

  71191.     for(j=1; j<nNew; j++){

  71192.       if( aPgOrder[j]<aPgOrder[iBest] ) iBest = j;

  71193.     }

  71194.     pgno = aPgOrder[iBest];

  71195.     aPgOrder[iBest] = 0xffffffff;

  71196.     if( iBest!=i ){

  71197.       if( iBest>i ){

  71198.         sqlite3PagerRekey(apNew[iBest]->pDbPage, pBt->nPage+iBest+1, 0);

  71199.       }

  71200.       sqlite3PagerRekey(apNew[i]->pDbPage, pgno, aPgFlags[iBest]);

  71201.       apNew[i]->pgno = pgno;

  71202.     }

  71203.   }

  71204. 

  71205.   TRACE(("BALANCE: new: %d(%d nc=%d) %d(%d nc=%d) %d(%d nc=%d) "

  71206.          "%d(%d nc=%d) %d(%d nc=%d)\n",

  71207.     apNew[0]->pgno, szNew[0], cntNew[0],

  71208.     nNew>=2 ? apNew[1]->pgno : 0, nNew>=2 ? szNew[1] : 0,

  71209.     nNew>=2 ? cntNew[1] - cntNew[0] - !leafData : 0,

  71210.     nNew>=3 ? apNew[2]->pgno : 0, nNew>=3 ? szNew[2] : 0,

  71211.     nNew>=3 ? cntNew[2] - cntNew[1] - !leafData : 0,

  71212.     nNew>=4 ? apNew[3]->pgno : 0, nNew>=4 ? szNew[3] : 0,

  71213.     nNew>=4 ? cntNew[3] - cntNew[2] - !leafData : 0,

  71214.     nNew>=5 ? apNew[4]->pgno : 0, nNew>=5 ? szNew[4] : 0,

  71215.     nNew>=5 ? cntNew[4] - cntNew[3] - !leafData : 0

  71216.   ));

  71217. 

  71218.   assert( sqlite3PagerIswriteable(pParent->pDbPage) );

  71219.   put4byte(pRight, apNew[nNew-1]->pgno);

  71220. 

  71221.   /* If the sibling pages are not leaves, ensure that the right-child pointer

  71222.   ** of the right-most new sibling page is set to the value that was 

  71223.   ** originally in the same field of the right-most old sibling page. */

  71224.   if( (pageFlags & PTF_LEAF)==0 && nOld!=nNew ){

  71225.     MemPage *pOld = (nNew>nOld ? apNew : apOld)[nOld-1];

  71226.     memcpy(&apNew[nNew-1]->aData[8], &pOld->aData[8], 4);

  71227.   }

  71228. 

  71229.   /* Make any required updates to pointer map entries associated with 

  71230.   ** cells stored on sibling pages following the balance operation. Pointer

  71231.   ** map entries associated with divider cells are set by the insertCell()

  71232.   ** routine. The associated pointer map entries are:

  71233.   **

  71234.   **   a) if the cell contains a reference to an overflow chain, the

  71235.   **      entry associated with the first page in the overflow chain, and

  71236.   **

  71237.   **   b) if the sibling pages are not leaves, the child page associated

  71238.   **      with the cell.

  71239.   **

  71240.   ** If the sibling pages are not leaves, then the pointer map entry 

  71241.   ** associated with the right-child of each sibling may also need to be 

  71242.   ** updated. This happens below, after the sibling pages have been 

  71243.   ** populated, not here.

  71244.   */

  71245.   if( ISAUTOVACUUM ){

  71246.     MemPage *pOld;

  71247.     MemPage *pNew = pOld = apNew[0];

  71248.     int cntOldNext = pNew->nCell + pNew->nOverflow;

  71249.     int iNew = 0;

  71250.     int iOld = 0;

  71251. 

  71252.     for(i=0; i<b.nCell; i++){

  71253.       u8 *pCell = b.apCell[i];

  71254.       while( i==cntOldNext ){

  71255.         iOld++;

  71256.         assert( iOld<nNew || iOld<nOld );

  71257.         assert( iOld>=0 && iOld<NB );

  71258.         pOld = iOld<nNew ? apNew[iOld] : apOld[iOld];

  71259.         cntOldNext += pOld->nCell + pOld->nOverflow + !leafData;

  71260.       }

  71261.       if( i==cntNew[iNew] ){

  71262.         pNew = apNew[++iNew];

  71263.         if( !leafData ) continue;

  71264.       }

  71265. 

  71266.       /* Cell pCell is destined for new sibling page pNew. Originally, it

  71267.       ** was either part of sibling page iOld (possibly an overflow cell), 

  71268.       ** or else the divider cell to the left of sibling page iOld. So,

  71269.       ** if sibling page iOld had the same page number as pNew, and if

  71270.       ** pCell really was a part of sibling page iOld (not a divider or

  71271.       ** overflow cell), we can skip updating the pointer map entries.  */

  71272.       if( iOld>=nNew

  71273.        || pNew->pgno!=aPgno[iOld]

  71274.        || !SQLITE_WITHIN(pCell,pOld->aData,pOld->aDataEnd)

  71275.       ){

  71276.         if( !leafCorrection ){

  71277.           ptrmapPut(pBt, get4byte(pCell), PTRMAP_BTREE, pNew->pgno, &rc);

  71278.         }

  71279.         if( cachedCellSize(&b,i)>pNew->minLocal ){

  71280.           ptrmapPutOvflPtr(pNew, pOld, pCell, &rc);

  71281.         }

  71282.         if( rc ) goto balance_cleanup;

  71283.       }

  71284.     }

  71285.   }

  71286. 

  71287.   /* Insert new divider cells into pParent. */

  71288.   for(i=0; i<nNew-1; i++){

  71289.     u8 *pCell;

  71290.     u8 *pTemp;

  71291.     int sz;

  71292.     MemPage *pNew = apNew[i];

  71293.     j = cntNew[i];

  71294. 

  71295.     assert( j<nMaxCells );

  71296.     assert( b.apCell[j]!=0 );

  71297.     pCell = b.apCell[j];

  71298.     sz = b.szCell[j] + leafCorrection;

  71299.     pTemp = &aOvflSpace[iOvflSpace];

  71300.     if( !pNew->leaf ){

  71301.       memcpy(&pNew->aData[8], pCell, 4);

  71302.     }else if( leafData ){

  71303.       /* If the tree is a leaf-data tree, and the siblings are leaves, 

  71304.       ** then there is no divider cell in b.apCell[]. Instead, the divider 

  71305.       ** cell consists of the integer key for the right-most cell of 

  71306.       ** the sibling-page assembled above only.

  71307.       */

  71308.       CellInfo info;

  71309.       j--;

  71310.       pNew->xParseCell(pNew, b.apCell[j], &info);

  71311.       pCell = pTemp;

  71312.       sz = 4 + putVarint(&pCell[4], info.nKey);

  71313.       pTemp = 0;

  71314.     }else{

  71315.       pCell -= 4;

  71316.       /* Obscure case for non-leaf-data trees: If the cell at pCell was

  71317.       ** previously stored on a leaf node, and its reported size was 4

  71318.       ** bytes, then it may actually be smaller than this 

  71319.       ** (see btreeParseCellPtr(), 4 bytes is the minimum size of

  71320.       ** any cell). But it is important to pass the correct size to 

  71321.       ** insertCell(), so reparse the cell now.

  71322.       **

  71323.       ** This can only happen for b-trees used to evaluate "IN (SELECT ...)"

  71324.       ** and WITHOUT ROWID tables with exactly one column which is the

  71325.       ** primary key.

  71326.       */

  71327.       if( b.szCell[j]==4 ){

  71328.         assert(leafCorrection==4);

  71329.         sz = pParent->xCellSize(pParent, pCell);

  71330.       }

  71331.     }

  71332.     iOvflSpace += sz;

  71333.     assert( sz<=pBt->maxLocal+23 );

  71334.     assert( iOvflSpace <= (int)pBt->pageSize );

  71335.     insertCell(pParent, nxDiv+i, pCell, sz, pTemp, pNew->pgno, &rc);

  71336.     if( rc!=SQLITE_OK ) goto balance_cleanup;

  71337.     assert( sqlite3PagerIswriteable(pParent->pDbPage) );

  71338.   }

  71339. 

  71340.   /* Now update the actual sibling pages. The order in which they are updated

  71341.   ** is important, as this code needs to avoid disrupting any page from which

  71342.   ** cells may still to be read. In practice, this means:

  71343.   **

  71344.   **  (1) If cells are moving left (from apNew[iPg] to apNew[iPg-1])

  71345.   **      then it is not safe to update page apNew[iPg] until after

  71346.   **      the left-hand sibling apNew[iPg-1] has been updated.

  71347.   **

  71348.   **  (2) If cells are moving right (from apNew[iPg] to apNew[iPg+1])

  71349.   **      then it is not safe to update page apNew[iPg] until after

  71350.   **      the right-hand sibling apNew[iPg+1] has been updated.

  71351.   **

  71352.   ** If neither of the above apply, the page is safe to update.

  71353.   **

  71354.   ** The iPg value in the following loop starts at nNew-1 goes down

  71355.   ** to 0, then back up to nNew-1 again, thus making two passes over

  71356.   ** the pages.  On the initial downward pass, only condition (1) above

  71357.   ** needs to be tested because (2) will always be true from the previous

  71358.   ** step.  On the upward pass, both conditions are always true, so the

  71359.   ** upwards pass simply processes pages that were missed on the downward

  71360.   ** pass.

  71361.   */

  71362.   for(i=1-nNew; i<nNew; i++){

  71363.     int iPg = i<0 ? -i : i;

  71364.     assert( iPg>=0 && iPg<nNew );

  71365.     if( abDone[iPg] ) continue;         /* Skip pages already processed */

  71366.     if( i>=0                            /* On the upwards pass, or... */

  71367.      || cntOld[iPg-1]>=cntNew[iPg-1]    /* Condition (1) is true */

  71368.     ){

  71369.       int iNew;

  71370.       int iOld;

  71371.       int nNewCell;

  71372. 

  71373.       /* Verify condition (1):  If cells are moving left, update iPg

  71374.       ** only after iPg-1 has already been updated. */

  71375.       assert( iPg==0 || cntOld[iPg-1]>=cntNew[iPg-1] || abDone[iPg-1] );

  71376. 

  71377.       /* Verify condition (2):  If cells are moving right, update iPg

  71378.       ** only after iPg+1 has already been updated. */

  71379.       assert( cntNew[iPg]>=cntOld[iPg] || abDone[iPg+1] );

  71380. 

  71381.       if( iPg==0 ){

  71382.         iNew = iOld = 0;

  71383.         nNewCell = cntNew[0];

  71384.       }else{

  71385.         iOld = iPg<nOld ? (cntOld[iPg-1] + !leafData) : b.nCell;

  71386.         iNew = cntNew[iPg-1] + !leafData;

  71387.         nNewCell = cntNew[iPg] - iNew;

  71388.       }

  71389. 

  71390.       rc = editPage(apNew[iPg], iOld, iNew, nNewCell, &b);

  71391.       if( rc ) goto balance_cleanup;

  71392.       abDone[iPg]++;

  71393.       apNew[iPg]->nFree = usableSpace-szNew[iPg];

  71394.       assert( apNew[iPg]->nOverflow==0 );

  71395.       assert( apNew[iPg]->nCell==nNewCell );

  71396.     }

  71397.   }

  71398. 

  71399.   /* All pages have been processed exactly once */

  71400.   assert( memcmp(abDone, "\01\01\01\01\01", nNew)==0 );

  71401. 

  71402.   assert( nOld>0 );

  71403.   assert( nNew>0 );

  71404. 

  71405.   if( isRoot && pParent->nCell==0 && pParent->hdrOffset<=apNew[0]->nFree ){

  71406.     /* The root page of the b-tree now contains no cells. The only sibling

  71407.     ** page is the right-child of the parent. Copy the contents of the

  71408.     ** child page into the parent, decreasing the overall height of the

  71409.     ** b-tree structure by one. This is described as the "balance-shallower"

  71410.     ** sub-algorithm in some documentation.

  71411.     **

  71412.     ** If this is an auto-vacuum database, the call to copyNodeContent() 

  71413.     ** sets all pointer-map entries corresponding to database image pages 

  71414.     ** for which the pointer is stored within the content being copied.

  71415.     **

  71416.     ** It is critical that the child page be defragmented before being

  71417.     ** copied into the parent, because if the parent is page 1 then it will

  71418.     ** by smaller than the child due to the database header, and so all the

  71419.     ** free space needs to be up front.

  71420.     */

  71421.     assert( nNew==1 || CORRUPT_DB );

  71422.     rc = defragmentPage(apNew[0], -1);

  71423.     testcase( rc!=SQLITE_OK );

  71424.     assert( apNew[0]->nFree == 

  71425.         (get2byteNotZero(&apNew[0]->aData[5]) - apNew[0]->cellOffset

  71426.           - apNew[0]->nCell*2)

  71427.       || rc!=SQLITE_OK

  71428.     );

  71429.     copyNodeContent(apNew[0], pParent, &rc);

  71430.     freePage(apNew[0], &rc);

  71431.   }else if( ISAUTOVACUUM && !leafCorrection ){

  71432.     /* Fix the pointer map entries associated with the right-child of each

  71433.     ** sibling page. All other pointer map entries have already been taken

  71434.     ** care of.  */

  71435.     for(i=0; i<nNew; i++){

  71436.       u32 key = get4byte(&apNew[i]->aData[8]);

  71437.       ptrmapPut(pBt, key, PTRMAP_BTREE, apNew[i]->pgno, &rc);

  71438.     }

  71439.   }

  71440. 

  71441.   assert( pParent->isInit );

  71442.   TRACE(("BALANCE: finished: old=%d new=%d cells=%d\n",

  71443.           nOld, nNew, b.nCell));

  71444. 

  71445.   /* Free any old pages that were not reused as new pages.

  71446.   */

  71447.   for(i=nNew; i<nOld; i++){

  71448.     freePage(apOld[i], &rc);

  71449.   }

  71450. 

  71451. #if 0

  71452.   if( ISAUTOVACUUM && rc==SQLITE_OK && apNew[0]->isInit ){

  71453.     /* The ptrmapCheckPages() contains assert() statements that verify that

  71454.     ** all pointer map pages are set correctly. This is helpful while 

  71455.     ** debugging. This is usually disabled because a corrupt database may

  71456.     ** cause an assert() statement to fail.  */

  71457.     ptrmapCheckPages(apNew, nNew);

  71458.     ptrmapCheckPages(&pParent, 1);

  71459.   }

  71460. #endif

  71461. 

  71462.   /*

  71463.   ** Cleanup before returning.

  71464.   */

  71465. balance_cleanup:

  71466.   sqlite3StackFree(0, b.apCell);

  71467.   for(i=0; i<nOld; i++){

  71468.     releasePage(apOld[i]);

  71469.   }

  71470.   for(i=0; i<nNew; i++){

  71471.     releasePage(apNew[i]);

  71472.   }

  71473. 

  71474.   return rc;

  71475. }

  71476. 

  71477. 

  71478. /*

  71479. ** This function is called when the root page of a b-tree structure is

  71480. ** overfull (has one or more overflow pages).

  71481. **

  71482. ** A new child page is allocated and the contents of the current root

  71483. ** page, including overflow cells, are copied into the child. The root

  71484. ** page is then overwritten to make it an empty page with the right-child 

  71485. ** pointer pointing to the new page.

  71486. **

  71487. ** Before returning, all pointer-map entries corresponding to pages 

  71488. ** that the new child-page now contains pointers to are updated. The

  71489. ** entry corresponding to the new right-child pointer of the root

  71490. ** page is also updated.

  71491. **

  71492. ** If successful, *ppChild is set to contain a reference to the child 

  71493. ** page and SQLITE_OK is returned. In this case the caller is required

  71494. ** to call releasePage() on *ppChild exactly once. If an error occurs,

  71495. ** an error code is returned and *ppChild is set to 0.

  71496. */

  71497. static int balance_deeper(MemPage *pRoot, MemPage **ppChild){

  71498.   int rc;                        /* Return value from subprocedures */

  71499.   MemPage *pChild = 0;           /* Pointer to a new child page */

  71500.   Pgno pgnoChild = 0;            /* Page number of the new child page */

  71501.   BtShared *pBt = pRoot->pBt;    /* The BTree */

  71502. 

  71503.   assert( pRoot->nOverflow>0 );

  71504.   assert( sqlite3_mutex_held(pBt->mutex) );

  71505. 

  71506.   /* Make pRoot, the root page of the b-tree, writable. Allocate a new 

  71507.   ** page that will become the new right-child of pPage. Copy the contents

  71508.   ** of the node stored on pRoot into the new child page.

  71509.   */

  71510.   rc = sqlite3PagerWrite(pRoot->pDbPage);

  71511.   if( rc==SQLITE_OK ){

  71512.     rc = allocateBtreePage(pBt,&pChild,&pgnoChild,pRoot->pgno,0);

  71513.     copyNodeContent(pRoot, pChild, &rc);

  71514.     if( ISAUTOVACUUM ){

  71515.       ptrmapPut(pBt, pgnoChild, PTRMAP_BTREE, pRoot->pgno, &rc);

  71516.     }

  71517.   }

  71518.   if( rc ){

  71519.     *ppChild = 0;

  71520.     releasePage(pChild);

  71521.     return rc;

  71522.   }

  71523.   assert( sqlite3PagerIswriteable(pChild->pDbPage) );

  71524.   assert( sqlite3PagerIswriteable(pRoot->pDbPage) );

  71525.   assert( pChild->nCell==pRoot->nCell || CORRUPT_DB );

  71526. 

  71527.   TRACE(("BALANCE: copy root %d into %d\n", pRoot->pgno, pChild->pgno));

  71528. 

  71529.   /* Copy the overflow cells from pRoot to pChild */

  71530.   memcpy(pChild->aiOvfl, pRoot->aiOvfl,

  71531.          pRoot->nOverflow*sizeof(pRoot->aiOvfl[0]));

  71532.   memcpy(pChild->apOvfl, pRoot->apOvfl,

  71533.          pRoot->nOverflow*sizeof(pRoot->apOvfl[0]));

  71534.   pChild->nOverflow = pRoot->nOverflow;

  71535. 

  71536.   /* Zero the contents of pRoot. Then install pChild as the right-child. */

  71537.   zeroPage(pRoot, pChild->aData[0] & ~PTF_LEAF);

  71538.   put4byte(&pRoot->aData[pRoot->hdrOffset+8], pgnoChild);

  71539. 

  71540.   *ppChild = pChild;

  71541.   return SQLITE_OK;

  71542. }

  71543. 

  71544. /*

  71545. ** The page that pCur currently points to has just been modified in

  71546. ** some way. This function figures out if this modification means the

  71547. ** tree needs to be balanced, and if so calls the appropriate balancing 

  71548. ** routine. Balancing routines are:

  71549. **

  71550. **   balance_quick()

  71551. **   balance_deeper()

  71552. **   balance_nonroot()

  71553. */

  71554. static int balance(BtCursor *pCur){

  71555.   int rc = SQLITE_OK;

  71556.   const int nMin = pCur->pBt->usableSize * 2 / 3;

  71557.   u8 aBalanceQuickSpace[13];

  71558.   u8 *pFree = 0;

  71559. 

  71560.   VVA_ONLY( int balance_quick_called = 0 );

  71561.   VVA_ONLY( int balance_deeper_called = 0 );

  71562. 

  71563.   do {

  71564.     int iPage = pCur->iPage;

  71565.     MemPage *pPage = pCur->pPage;

  71566. 

  71567.     if( NEVER(pPage->nFree<0) && btreeComputeFreeSpace(pPage) ) break;

  71568.     if( iPage==0 ){

  71569.       if( pPage->nOverflow ){

  71570.         /* The root page of the b-tree is overfull. In this case call the

  71571.         ** balance_deeper() function to create a new child for the root-page

  71572.         ** and copy the current contents of the root-page to it. The

  71573.         ** next iteration of the do-loop will balance the child page.

  71574.         */ 

  71575.         assert( balance_deeper_called==0 );

  71576.         VVA_ONLY( balance_deeper_called++ );

  71577.         rc = balance_deeper(pPage, &pCur->apPage[1]);

  71578.         if( rc==SQLITE_OK ){

  71579.           pCur->iPage = 1;

  71580.           pCur->ix = 0;

  71581.           pCur->aiIdx[0] = 0;

  71582.           pCur->apPage[0] = pPage;

  71583.           pCur->pPage = pCur->apPage[1];

  71584.           assert( pCur->pPage->nOverflow );

  71585.         }

  71586.       }else{

  71587.         break;

  71588.       }

  71589.     }else if( pPage->nOverflow==0 && pPage->nFree<=nMin ){

  71590.       break;

  71591.     }else{

  71592.       MemPage * const pParent = pCur->apPage[iPage-1];

  71593.       int const iIdx = pCur->aiIdx[iPage-1];

  71594. 

  71595.       rc = sqlite3PagerWrite(pParent->pDbPage);

  71596.       if( rc==SQLITE_OK && pParent->nFree<0 ){

  71597.         rc = btreeComputeFreeSpace(pParent);

  71598.       }

  71599.       if( rc==SQLITE_OK ){

  71600. #ifndef SQLITE_OMIT_QUICKBALANCE

  71601.         if( pPage->intKeyLeaf

  71602.          && pPage->nOverflow==1

  71603.          && pPage->aiOvfl[0]==pPage->nCell

  71604.          && pParent->pgno!=1

  71605.          && pParent->nCell==iIdx

  71606.         ){

  71607.           /* Call balance_quick() to create a new sibling of pPage on which

  71608.           ** to store the overflow cell. balance_quick() inserts a new cell

  71609.           ** into pParent, which may cause pParent overflow. If this

  71610.           ** happens, the next iteration of the do-loop will balance pParent 

  71611.           ** use either balance_nonroot() or balance_deeper(). Until this

  71612.           ** happens, the overflow cell is stored in the aBalanceQuickSpace[]

  71613.           ** buffer. 

  71614.           **

  71615.           ** The purpose of the following assert() is to check that only a

  71616.           ** single call to balance_quick() is made for each call to this

  71617.           ** function. If this were not verified, a subtle bug involving reuse

  71618.           ** of the aBalanceQuickSpace[] might sneak in.

  71619.           */

  71620.           assert( balance_quick_called==0 ); 

  71621.           VVA_ONLY( balance_quick_called++ );

  71622.           rc = balance_quick(pParent, pPage, aBalanceQuickSpace);

  71623.         }else

  71624. #endif

  71625.         {

  71626.           /* In this case, call balance_nonroot() to redistribute cells

  71627.           ** between pPage and up to 2 of its sibling pages. This involves

  71628.           ** modifying the contents of pParent, which may cause pParent to

  71629.           ** become overfull or underfull. The next iteration of the do-loop

  71630.           ** will balance the parent page to correct this.

  71631.           ** 

  71632.           ** If the parent page becomes overfull, the overflow cell or cells

  71633.           ** are stored in the pSpace buffer allocated immediately below. 

  71634.           ** A subsequent iteration of the do-loop will deal with this by

  71635.           ** calling balance_nonroot() (balance_deeper() may be called first,

  71636.           ** but it doesn't deal with overflow cells - just moves them to a

  71637.           ** different page). Once this subsequent call to balance_nonroot() 

  71638.           ** has completed, it is safe to release the pSpace buffer used by

  71639.           ** the previous call, as the overflow cell data will have been 

  71640.           ** copied either into the body of a database page or into the new

  71641.           ** pSpace buffer passed to the latter call to balance_nonroot().

  71642.           */

  71643.           u8 *pSpace = sqlite3PageMalloc(pCur->pBt->pageSize);

  71644.           rc = balance_nonroot(pParent, iIdx, pSpace, iPage==1,

  71645.                                pCur->hints&BTREE_BULKLOAD);

  71646.           if( pFree ){

  71647.             /* If pFree is not NULL, it points to the pSpace buffer used 

  71648.             ** by a previous call to balance_nonroot(). Its contents are

  71649.             ** now stored either on real database pages or within the 

  71650.             ** new pSpace buffer, so it may be safely freed here. */

  71651.             sqlite3PageFree(pFree);

  71652.           }

  71653. 

  71654.           /* The pSpace buffer will be freed after the next call to

  71655.           ** balance_nonroot(), or just before this function returns, whichever

  71656.           ** comes first. */

  71657.           pFree = pSpace;

  71658.         }

  71659.       }

  71660. 

  71661.       pPage->nOverflow = 0;

  71662. 

  71663.       /* The next iteration of the do-loop balances the parent page. */

  71664.       releasePage(pPage);

  71665.       pCur->iPage--;

  71666.       assert( pCur->iPage>=0 );

  71667.       pCur->pPage = pCur->apPage[pCur->iPage];

  71668.     }

  71669.   }while( rc==SQLITE_OK );

  71670. 

  71671.   if( pFree ){

  71672.     sqlite3PageFree(pFree);

  71673.   }

  71674.   return rc;

  71675. }

  71676. 

  71677. /* Overwrite content from pX into pDest.  Only do the write if the

  71678. ** content is different from what is already there.

  71679. */

  71680. static int btreeOverwriteContent(

  71681.   MemPage *pPage,           /* MemPage on which writing will occur */

  71682.   u8 *pDest,                /* Pointer to the place to start writing */

  71683.   const BtreePayload *pX,   /* Source of data to write */

  71684.   int iOffset,              /* Offset of first byte to write */

  71685.   int iAmt                  /* Number of bytes to be written */

  71686. ){

  71687.   int nData = pX->nData - iOffset;

  71688.   if( nData<=0 ){

  71689.     /* Overwritting with zeros */

  71690.     int i;

  71691.     for(i=0; i<iAmt && pDest[i]==0; i++){}

  71692.     if( i<iAmt ){

  71693.       int rc = sqlite3PagerWrite(pPage->pDbPage);

  71694.       if( rc ) return rc;

  71695.       memset(pDest + i, 0, iAmt - i);

  71696.     }

  71697.   }else{

  71698.     if( nData<iAmt ){

  71699.       /* Mixed read data and zeros at the end.  Make a recursive call

  71700.       ** to write the zeros then fall through to write the real data */

  71701.       int rc = btreeOverwriteContent(pPage, pDest+nData, pX, iOffset+nData,

  71702.                                  iAmt-nData);

  71703.       if( rc ) return rc;

  71704.       iAmt = nData;

  71705.     }

  71706.     if( memcmp(pDest, ((u8*)pX->pData) + iOffset, iAmt)!=0 ){

  71707.       int rc = sqlite3PagerWrite(pPage->pDbPage);

  71708.       if( rc ) return rc;

  71709.       /* In a corrupt database, it is possible for the source and destination

  71710.       ** buffers to overlap.  This is harmless since the database is already

  71711.       ** corrupt but it does cause valgrind and ASAN warnings.  So use

  71712.       ** memmove(). */

  71713.       memmove(pDest, ((u8*)pX->pData) + iOffset, iAmt);

  71714.     }

  71715.   }

  71716.   return SQLITE_OK;

  71717. }

  71718. 

  71719. /*

  71720. ** Overwrite the cell that cursor pCur is pointing to with fresh content

  71721. ** contained in pX.

  71722. */

  71723. static int btreeOverwriteCell(BtCursor *pCur, const BtreePayload *pX){

  71724.   int iOffset;                        /* Next byte of pX->pData to write */

  71725.   int nTotal = pX->nData + pX->nZero; /* Total bytes of to write */

  71726.   int rc;                             /* Return code */

  71727.   MemPage *pPage = pCur->pPage;       /* Page being written */

  71728.   BtShared *pBt;                      /* Btree */

  71729.   Pgno ovflPgno;                      /* Next overflow page to write */

  71730.   u32 ovflPageSize;                   /* Size to write on overflow page */

  71731. 

  71732.   if( pCur->info.pPayload + pCur->info.nLocal > pPage->aDataEnd ){

  71733.     return SQLITE_CORRUPT_BKPT;

  71734.   }

  71735.   /* Overwrite the local portion first */

  71736.   rc = btreeOverwriteContent(pPage, pCur->info.pPayload, pX,

  71737.                              0, pCur->info.nLocal);

  71738.   if( rc ) return rc;

  71739.   if( pCur->info.nLocal==nTotal ) return SQLITE_OK;

  71740. 

  71741.   /* Now overwrite the overflow pages */

  71742.   iOffset = pCur->info.nLocal;

  71743.   assert( nTotal>=0 );

  71744.   assert( iOffset>=0 );

  71745.   ovflPgno = get4byte(pCur->info.pPayload + iOffset);

  71746.   pBt = pPage->pBt;

  71747.   ovflPageSize = pBt->usableSize - 4;

  71748.   do{

  71749.     rc = btreeGetPage(pBt, ovflPgno, &pPage, 0);

  71750.     if( rc ) return rc;

  71751.     if( sqlite3PagerPageRefcount(pPage->pDbPage)!=1 ){

  71752.       rc = SQLITE_CORRUPT_BKPT;

  71753.     }else{

  71754.       if( iOffset+ovflPageSize<(u32)nTotal ){

  71755.         ovflPgno = get4byte(pPage->aData);

  71756.       }else{

  71757.         ovflPageSize = nTotal - iOffset;

  71758.       }

  71759.       rc = btreeOverwriteContent(pPage, pPage->aData+4, pX,

  71760.                                  iOffset, ovflPageSize);

  71761.     }

  71762.     sqlite3PagerUnref(pPage->pDbPage);

  71763.     if( rc ) return rc;

  71764.     iOffset += ovflPageSize;

  71765.   }while( iOffset<nTotal );

  71766.   return SQLITE_OK;    

  71767. }

  71768. 

  71769. 

  71770. /*

  71771. ** Insert a new record into the BTree.  The content of the new record

  71772. ** is described by the pX object.  The pCur cursor is used only to

  71773. ** define what table the record should be inserted into, and is left

  71774. ** pointing at a random location.

  71775. **

  71776. ** For a table btree (used for rowid tables), only the pX.nKey value of

  71777. ** the key is used. The pX.pKey value must be NULL.  The pX.nKey is the

  71778. ** rowid or INTEGER PRIMARY KEY of the row.  The pX.nData,pData,nZero fields

  71779. ** hold the content of the row.

  71780. **

  71781. ** For an index btree (used for indexes and WITHOUT ROWID tables), the

  71782. ** key is an arbitrary byte sequence stored in pX.pKey,nKey.  The 

  71783. ** pX.pData,nData,nZero fields must be zero.

  71784. **

  71785. ** If the seekResult parameter is non-zero, then a successful call to

  71786. ** MovetoUnpacked() to seek cursor pCur to (pKey,nKey) has already

  71787. ** been performed.  In other words, if seekResult!=0 then the cursor

  71788. ** is currently pointing to a cell that will be adjacent to the cell

  71789. ** to be inserted.  If seekResult<0 then pCur points to a cell that is

  71790. ** smaller then (pKey,nKey).  If seekResult>0 then pCur points to a cell

  71791. ** that is larger than (pKey,nKey).

  71792. **

  71793. ** If seekResult==0, that means pCur is pointing at some unknown location.

  71794. ** In that case, this routine must seek the cursor to the correct insertion

  71795. ** point for (pKey,nKey) before doing the insertion.  For index btrees,

  71796. ** if pX->nMem is non-zero, then pX->aMem contains pointers to the unpacked

  71797. ** key values and pX->aMem can be used instead of pX->pKey to avoid having

  71798. ** to decode the key.

  71799. */

  71800. SQLITE_PRIVATE int sqlite3BtreeInsert(

  71801.   BtCursor *pCur,                /* Insert data into the table of this cursor */

  71802.   const BtreePayload *pX,        /* Content of the row to be inserted */

  71803.   int flags,                     /* True if this is likely an append */

  71804.   int seekResult                 /* Result of prior MovetoUnpacked() call */

  71805. ){

  71806.   int rc;

  71807.   int loc = seekResult;          /* -1: before desired location  +1: after */

  71808.   int szNew = 0;

  71809.   int idx;

  71810.   MemPage *pPage;

  71811.   Btree *p = pCur->pBtree;

  71812.   BtShared *pBt = p->pBt;

  71813.   unsigned char *oldCell;

  71814.   unsigned char *newCell = 0;

  71815. 

  71816.   assert( (flags & (BTREE_SAVEPOSITION|BTREE_APPEND))==flags );

  71817. 

  71818.   if( pCur->eState==CURSOR_FAULT ){

  71819.     assert( pCur->skipNext!=SQLITE_OK );

  71820.     return pCur->skipNext;

  71821.   }

  71822. 

  71823.   assert( cursorOwnsBtShared(pCur) );

  71824.   assert( (pCur->curFlags & BTCF_WriteFlag)!=0

  71825.               && pBt->inTransaction==TRANS_WRITE

  71826.               && (pBt->btsFlags & BTS_READ_ONLY)==0 );

  71827.   assert( hasSharedCacheTableLock(p, pCur->pgnoRoot, pCur->pKeyInfo!=0, 2) );

  71828. 

  71829.   /* Assert that the caller has been consistent. If this cursor was opened

  71830.   ** expecting an index b-tree, then the caller should be inserting blob

  71831.   ** keys with no associated data. If the cursor was opened expecting an

  71832.   ** intkey table, the caller should be inserting integer keys with a

  71833.   ** blob of associated data.  */

  71834.   assert( (pX->pKey==0)==(pCur->pKeyInfo==0) );

  71835. 

  71836.   /* Save the positions of any other cursors open on this table.

  71837.   **

  71838.   ** In some cases, the call to btreeMoveto() below is a no-op. For

  71839.   ** example, when inserting data into a table with auto-generated integer

  71840.   ** keys, the VDBE layer invokes sqlite3BtreeLast() to figure out the 

  71841.   ** integer key to use. It then calls this function to actually insert the 

  71842.   ** data into the intkey B-Tree. In this case btreeMoveto() recognizes

  71843.   ** that the cursor is already where it needs to be and returns without

  71844.   ** doing any work. To avoid thwarting these optimizations, it is important

  71845.   ** not to clear the cursor here.

  71846.   */

  71847.   if( pCur->curFlags & BTCF_Multiple ){

  71848.     rc = saveAllCursors(pBt, pCur->pgnoRoot, pCur);

  71849.     if( rc ) return rc;

  71850.   }

  71851. 

  71852.   if( pCur->pKeyInfo==0 ){

  71853.     assert( pX->pKey==0 );

  71854.     /* If this is an insert into a table b-tree, invalidate any incrblob 

  71855.     ** cursors open on the row being replaced */

  71856.     invalidateIncrblobCursors(p, pCur->pgnoRoot, pX->nKey, 0);

  71857. 

  71858.     /* If BTREE_SAVEPOSITION is set, the cursor must already be pointing 

  71859.     ** to a row with the same key as the new entry being inserted.

  71860.     */

  71861. #ifdef SQLITE_DEBUG

  71862.     if( flags & BTREE_SAVEPOSITION ){

  71863.       assert( pCur->curFlags & BTCF_ValidNKey );

  71864.       assert( pX->nKey==pCur->info.nKey );

  71865.       assert( pCur->info.nSize!=0 );

  71866.       assert( loc==0 );

  71867.     }

  71868. #endif

  71869. 

  71870.     /* On the other hand, BTREE_SAVEPOSITION==0 does not imply

  71871.     ** that the cursor is not pointing to a row to be overwritten.

  71872.     ** So do a complete check.

  71873.     */

  71874.     if( (pCur->curFlags&BTCF_ValidNKey)!=0 && pX->nKey==pCur->info.nKey ){

  71875.       /* The cursor is pointing to the entry that is to be

  71876.       ** overwritten */

  71877.       assert( pX->nData>=0 && pX->nZero>=0 );

  71878.       if( pCur->info.nSize!=0

  71879.        && pCur->info.nPayload==(u32)pX->nData+pX->nZero

  71880.       ){

  71881.         /* New entry is the same size as the old.  Do an overwrite */

  71882.         return btreeOverwriteCell(pCur, pX);

  71883.       }

  71884.       assert( loc==0 );

  71885.     }else if( loc==0 ){

  71886.       /* The cursor is *not* pointing to the cell to be overwritten, nor

  71887.       ** to an adjacent cell.  Move the cursor so that it is pointing either

  71888.       ** to the cell to be overwritten or an adjacent cell.

  71889.       */

  71890.       rc = sqlite3BtreeMovetoUnpacked(pCur, 0, pX->nKey, flags!=0, &loc);

  71891.       if( rc ) return rc;

  71892.     }

  71893.   }else{

  71894.     /* This is an index or a WITHOUT ROWID table */

  71895. 

  71896.     /* If BTREE_SAVEPOSITION is set, the cursor must already be pointing 

  71897.     ** to a row with the same key as the new entry being inserted.

  71898.     */

  71899.     assert( (flags & BTREE_SAVEPOSITION)==0 || loc==0 );

  71900. 

  71901.     /* If the cursor is not already pointing either to the cell to be

  71902.     ** overwritten, or if a new cell is being inserted, if the cursor is

  71903.     ** not pointing to an immediately adjacent cell, then move the cursor

  71904.     ** so that it does.

  71905.     */

  71906.     if( loc==0 && (flags & BTREE_SAVEPOSITION)==0 ){

  71907.       if( pX->nMem ){

  71908.         UnpackedRecord r;

  71909.         r.pKeyInfo = pCur->pKeyInfo;

  71910.         r.aMem = pX->aMem;

  71911.         r.nField = pX->nMem;

  71912.         r.default_rc = 0;

  71913.         r.errCode = 0;

  71914.         r.r1 = 0;

  71915.         r.r2 = 0;

  71916.         r.eqSeen = 0;

  71917.         rc = sqlite3BtreeMovetoUnpacked(pCur, &r, 0, flags!=0, &loc);

  71918.       }else{

  71919.         rc = btreeMoveto(pCur, pX->pKey, pX->nKey, flags!=0, &loc);

  71920.       }

  71921.       if( rc ) return rc;

  71922.     }

  71923. 

  71924.     /* If the cursor is currently pointing to an entry to be overwritten

  71925.     ** and the new content is the same as as the old, then use the

  71926.     ** overwrite optimization.

  71927.     */

  71928.     if( loc==0 ){

  71929.       getCellInfo(pCur);

  71930.       if( pCur->info.nKey==pX->nKey ){

  71931.         BtreePayload x2;

  71932.         x2.pData = pX->pKey;

  71933.         x2.nData = pX->nKey;

  71934.         x2.nZero = 0;

  71935.         return btreeOverwriteCell(pCur, &x2);

  71936.       }

  71937.     }

  71938. 

  71939.   }

  71940.   assert( pCur->eState==CURSOR_VALID || (pCur->eState==CURSOR_INVALID && loc) );

  71941. 

  71942.   pPage = pCur->pPage;

  71943.   assert( pPage->intKey || pX->nKey>=0 );

  71944.   assert( pPage->leaf || !pPage->intKey );

  71945.   if( pPage->nFree<0 ){

  71946.     rc = btreeComputeFreeSpace(pPage);

  71947.     if( rc ) return rc;

  71948.   }

  71949. 

  71950.   TRACE(("INSERT: table=%d nkey=%lld ndata=%d page=%d %s\n",

  71951.           pCur->pgnoRoot, pX->nKey, pX->nData, pPage->pgno,

  71952.           loc==0 ? "overwrite" : "new entry"));

  71953.   assert( pPage->isInit );

  71954.   newCell = pBt->pTmpSpace;

  71955.   assert( newCell!=0 );

  71956.   rc = fillInCell(pPage, newCell, pX, &szNew);

  71957.   if( rc ) goto end_insert;

  71958.   assert( szNew==pPage->xCellSize(pPage, newCell) );

  71959.   assert( szNew <= MX_CELL_SIZE(pBt) );

  71960.   idx = pCur->ix;

  71961.   if( loc==0 ){

  71962.     CellInfo info;

  71963.     assert( idx<pPage->nCell );

  71964.     rc = sqlite3PagerWrite(pPage->pDbPage);

  71965.     if( rc ){

  71966.       goto end_insert;

  71967.     }

  71968.     oldCell = findCell(pPage, idx);

  71969.     if( !pPage->leaf ){

  71970.       memcpy(newCell, oldCell, 4);

  71971.     }

  71972.     rc = clearCell(pPage, oldCell, &info);

  71973.     if( info.nSize==szNew && info.nLocal==info.nPayload 

  71974.      && (!ISAUTOVACUUM || szNew<pPage->minLocal)

  71975.     ){

  71976.       /* Overwrite the old cell with the new if they are the same size.

  71977.       ** We could also try to do this if the old cell is smaller, then add

  71978.       ** the leftover space to the free list.  But experiments show that

  71979.       ** doing that is no faster then skipping this optimization and just

  71980.       ** calling dropCell() and insertCell(). 

  71981.       **

  71982.       ** This optimization cannot be used on an autovacuum database if the

  71983.       ** new entry uses overflow pages, as the insertCell() call below is

  71984.       ** necessary to add the PTRMAP_OVERFLOW1 pointer-map entry.  */

  71985.       assert( rc==SQLITE_OK ); /* clearCell never fails when nLocal==nPayload */

  71986.       if( oldCell+szNew > pPage->aDataEnd ) return SQLITE_CORRUPT_BKPT;

  71987.       memcpy(oldCell, newCell, szNew);

  71988.       return SQLITE_OK;

  71989.     }

  71990.     dropCell(pPage, idx, info.nSize, &rc);

  71991.     if( rc ) goto end_insert;

  71992.   }else if( loc<0 && pPage->nCell>0 ){

  71993.     assert( pPage->leaf );

  71994.     idx = ++pCur->ix;

  71995.     pCur->curFlags &= ~BTCF_ValidNKey;

  71996.   }else{

  71997.     assert( pPage->leaf );

  71998.   }

  71999.   insertCell(pPage, idx, newCell, szNew, 0, 0, &rc);

  72000.   assert( pPage->nOverflow==0 || rc==SQLITE_OK );

  72001.   assert( rc!=SQLITE_OK || pPage->nCell>0 || pPage->nOverflow>0 );

  72002. 

  72003.   /* If no error has occurred and pPage has an overflow cell, call balance() 

  72004.   ** to redistribute the cells within the tree. Since balance() may move

  72005.   ** the cursor, zero the BtCursor.info.nSize and BTCF_ValidNKey

  72006.   ** variables.

  72007.   **

  72008.   ** Previous versions of SQLite called moveToRoot() to move the cursor

  72009.   ** back to the root page as balance() used to invalidate the contents

  72010.   ** of BtCursor.apPage[] and BtCursor.aiIdx[]. Instead of doing that,

  72011.   ** set the cursor state to "invalid". This makes common insert operations

  72012.   ** slightly faster.

  72013.   **

  72014.   ** There is a subtle but important optimization here too. When inserting

  72015.   ** multiple records into an intkey b-tree using a single cursor (as can

  72016.   ** happen while processing an "INSERT INTO ... SELECT" statement), it

  72017.   ** is advantageous to leave the cursor pointing to the last entry in

  72018.   ** the b-tree if possible. If the cursor is left pointing to the last

  72019.   ** entry in the table, and the next row inserted has an integer key

  72020.   ** larger than the largest existing key, it is possible to insert the

  72021.   ** row without seeking the cursor. This can be a big performance boost.

  72022.   */

  72023.   pCur->info.nSize = 0;

  72024.   if( pPage->nOverflow ){

  72025.     assert( rc==SQLITE_OK );

  72026.     pCur->curFlags &= ~(BTCF_ValidNKey);

  72027.     rc = balance(pCur);

  72028. 

  72029.     /* Must make sure nOverflow is reset to zero even if the balance()

  72030.     ** fails. Internal data structure corruption will result otherwise. 

  72031.     ** Also, set the cursor state to invalid. This stops saveCursorPosition()

  72032.     ** from trying to save the current position of the cursor.  */

  72033.     pCur->pPage->nOverflow = 0;

  72034.     pCur->eState = CURSOR_INVALID;

  72035.     if( (flags & BTREE_SAVEPOSITION) && rc==SQLITE_OK ){

  72036.       btreeReleaseAllCursorPages(pCur);

  72037.       if( pCur->pKeyInfo ){

  72038.         assert( pCur->pKey==0 );

  72039.         pCur->pKey = sqlite3Malloc( pX->nKey );

  72040.         if( pCur->pKey==0 ){

  72041.           rc = SQLITE_NOMEM;

  72042.         }else{

  72043.           memcpy(pCur->pKey, pX->pKey, pX->nKey);

  72044.         }

  72045.       }

  72046.       pCur->eState = CURSOR_REQUIRESEEK;

  72047.       pCur->nKey = pX->nKey;

  72048.     }

  72049.   }

  72050.   assert( pCur->iPage<0 || pCur->pPage->nOverflow==0 );

  72051. 

  72052. end_insert:

  72053.   return rc;

  72054. }

  72055. 

  72056. /*

  72057. ** Delete the entry that the cursor is pointing to. 

  72058. **

  72059. ** If the BTREE_SAVEPOSITION bit of the flags parameter is zero, then

  72060. ** the cursor is left pointing at an arbitrary location after the delete.

  72061. ** But if that bit is set, then the cursor is left in a state such that

  72062. ** the next call to BtreeNext() or BtreePrev() moves it to the same row

  72063. ** as it would have been on if the call to BtreeDelete() had been omitted.

  72064. **

  72065. ** The BTREE_AUXDELETE bit of flags indicates that is one of several deletes

  72066. ** associated with a single table entry and its indexes.  Only one of those

  72067. ** deletes is considered the "primary" delete.  The primary delete occurs

  72068. ** on a cursor that is not a BTREE_FORDELETE cursor.  All but one delete

  72069. ** operation on non-FORDELETE cursors is tagged with the AUXDELETE flag.

  72070. ** The BTREE_AUXDELETE bit is a hint that is not used by this implementation,

  72071. ** but which might be used by alternative storage engines.

  72072. */

  72073. SQLITE_PRIVATE int sqlite3BtreeDelete(BtCursor *pCur, u8 flags){

  72074.   Btree *p = pCur->pBtree;

  72075.   BtShared *pBt = p->pBt;              

  72076.   int rc;                              /* Return code */

  72077.   MemPage *pPage;                      /* Page to delete cell from */

  72078.   unsigned char *pCell;                /* Pointer to cell to delete */

  72079.   int iCellIdx;                        /* Index of cell to delete */

  72080.   int iCellDepth;                      /* Depth of node containing pCell */ 

  72081.   CellInfo info;                       /* Size of the cell being deleted */

  72082.   int bSkipnext = 0;                   /* Leaf cursor in SKIPNEXT state */

  72083.   u8 bPreserve = flags & BTREE_SAVEPOSITION;  /* Keep cursor valid */

  72084. 

  72085.   assert( cursorOwnsBtShared(pCur) );

  72086.   assert( pBt->inTransaction==TRANS_WRITE );

  72087.   assert( (pBt->btsFlags & BTS_READ_ONLY)==0 );

  72088.   assert( pCur->curFlags & BTCF_WriteFlag );

  72089.   assert( hasSharedCacheTableLock(p, pCur->pgnoRoot, pCur->pKeyInfo!=0, 2) );

  72090.   assert( !hasReadConflicts(p, pCur->pgnoRoot) );

  72091.   assert( (flags & ~(BTREE_SAVEPOSITION | BTREE_AUXDELETE))==0 );

  72092.   if( pCur->eState==CURSOR_REQUIRESEEK ){

  72093.     rc = btreeRestoreCursorPosition(pCur);

  72094.     if( rc ) return rc;

  72095.   }

  72096.   assert( pCur->eState==CURSOR_VALID );

  72097. 

  72098.   iCellDepth = pCur->iPage;

  72099.   iCellIdx = pCur->ix;

  72100.   pPage = pCur->pPage;

  72101.   pCell = findCell(pPage, iCellIdx);

  72102.   if( pPage->nFree<0 && btreeComputeFreeSpace(pPage) ) return SQLITE_CORRUPT;

  72103. 

  72104.   /* If the bPreserve flag is set to true, then the cursor position must

  72105.   ** be preserved following this delete operation. If the current delete

  72106.   ** will cause a b-tree rebalance, then this is done by saving the cursor

  72107.   ** key and leaving the cursor in CURSOR_REQUIRESEEK state before 

  72108.   ** returning. 

  72109.   **

  72110.   ** Or, if the current delete will not cause a rebalance, then the cursor

  72111.   ** will be left in CURSOR_SKIPNEXT state pointing to the entry immediately

  72112.   ** before or after the deleted entry. In this case set bSkipnext to true.  */

  72113.   if( bPreserve ){

  72114.     if( !pPage->leaf 

  72115.      || (pPage->nFree+cellSizePtr(pPage,pCell)+2)>(int)(pBt->usableSize*2/3)

  72116.      || pPage->nCell==1  /* See dbfuzz001.test for a test case */

  72117.     ){

  72118.       /* A b-tree rebalance will be required after deleting this entry.

  72119.       ** Save the cursor key.  */

  72120.       rc = saveCursorKey(pCur);

  72121.       if( rc ) return rc;

  72122.     }else{

  72123.       bSkipnext = 1;

  72124.     }

  72125.   }

  72126. 

  72127.   /* If the page containing the entry to delete is not a leaf page, move

  72128.   ** the cursor to the largest entry in the tree that is smaller than

  72129.   ** the entry being deleted. This cell will replace the cell being deleted

  72130.   ** from the internal node. The 'previous' entry is used for this instead

  72131.   ** of the 'next' entry, as the previous entry is always a part of the

  72132.   ** sub-tree headed by the child page of the cell being deleted. This makes

  72133.   ** balancing the tree following the delete operation easier.  */

  72134.   if( !pPage->leaf ){

  72135.     rc = sqlite3BtreePrevious(pCur, 0);

  72136.     assert( rc!=SQLITE_DONE );

  72137.     if( rc ) return rc;

  72138.   }

  72139. 

  72140.   /* Save the positions of any other cursors open on this table before

  72141.   ** making any modifications.  */

  72142.   if( pCur->curFlags & BTCF_Multiple ){

  72143.     rc = saveAllCursors(pBt, pCur->pgnoRoot, pCur);

  72144.     if( rc ) return rc;

  72145.   }

  72146. 

  72147.   /* If this is a delete operation to remove a row from a table b-tree,

  72148.   ** invalidate any incrblob cursors open on the row being deleted.  */

  72149.   if( pCur->pKeyInfo==0 ){

  72150.     invalidateIncrblobCursors(p, pCur->pgnoRoot, pCur->info.nKey, 0);

  72151.   }

  72152. 

  72153.   /* Make the page containing the entry to be deleted writable. Then free any

  72154.   ** overflow pages associated with the entry and finally remove the cell

  72155.   ** itself from within the page.  */

  72156.   rc = sqlite3PagerWrite(pPage->pDbPage);

  72157.   if( rc ) return rc;

  72158.   rc = clearCell(pPage, pCell, &info);

  72159.   dropCell(pPage, iCellIdx, info.nSize, &rc);

  72160.   if( rc ) return rc;

  72161. 

  72162.   /* If the cell deleted was not located on a leaf page, then the cursor

  72163.   ** is currently pointing to the largest entry in the sub-tree headed

  72164.   ** by the child-page of the cell that was just deleted from an internal

  72165.   ** node. The cell from the leaf node needs to be moved to the internal

  72166.   ** node to replace the deleted cell.  */

  72167.   if( !pPage->leaf ){

  72168.     MemPage *pLeaf = pCur->pPage;

  72169.     int nCell;

  72170.     Pgno n;

  72171.     unsigned char *pTmp;

  72172. 

  72173.     if( pLeaf->nFree<0 ){

  72174.       rc = btreeComputeFreeSpace(pLeaf);

  72175.       if( rc ) return rc;

  72176.     }

  72177.     if( iCellDepth<pCur->iPage-1 ){

  72178.       n = pCur->apPage[iCellDepth+1]->pgno;

  72179.     }else{

  72180.       n = pCur->pPage->pgno;

  72181.     }

  72182.     pCell = findCell(pLeaf, pLeaf->nCell-1);

  72183.     if( pCell<&pLeaf->aData[4] ) return SQLITE_CORRUPT_BKPT;

  72184.     nCell = pLeaf->xCellSize(pLeaf, pCell);

  72185.     assert( MX_CELL_SIZE(pBt) >= nCell );

  72186.     pTmp = pBt->pTmpSpace;

  72187.     assert( pTmp!=0 );

  72188.     rc = sqlite3PagerWrite(pLeaf->pDbPage);

  72189.     if( rc==SQLITE_OK ){

  72190.       insertCell(pPage, iCellIdx, pCell-4, nCell+4, pTmp, n, &rc);

  72191.     }

  72192.     dropCell(pLeaf, pLeaf->nCell-1, nCell, &rc);

  72193.     if( rc ) return rc;

  72194.   }

  72195. 

  72196.   /* Balance the tree. If the entry deleted was located on a leaf page,

  72197.   ** then the cursor still points to that page. In this case the first

  72198.   ** call to balance() repairs the tree, and the if(...) condition is

  72199.   ** never true.

  72200.   **

  72201.   ** Otherwise, if the entry deleted was on an internal node page, then

  72202.   ** pCur is pointing to the leaf page from which a cell was removed to

  72203.   ** replace the cell deleted from the internal node. This is slightly

  72204.   ** tricky as the leaf node may be underfull, and the internal node may

  72205.   ** be either under or overfull. In this case run the balancing algorithm

  72206.   ** on the leaf node first. If the balance proceeds far enough up the

  72207.   ** tree that we can be sure that any problem in the internal node has

  72208.   ** been corrected, so be it. Otherwise, after balancing the leaf node,

  72209.   ** walk the cursor up the tree to the internal node and balance it as 

  72210.   ** well.  */

  72211.   rc = balance(pCur);

  72212.   if( rc==SQLITE_OK && pCur->iPage>iCellDepth ){

  72213.     releasePageNotNull(pCur->pPage);

  72214.     pCur->iPage--;

  72215.     while( pCur->iPage>iCellDepth ){

  72216.       releasePage(pCur->apPage[pCur->iPage--]);

  72217.     }

  72218.     pCur->pPage = pCur->apPage[pCur->iPage];

  72219.     rc = balance(pCur);

  72220.   }

  72221. 

  72222.   if( rc==SQLITE_OK ){

  72223.     if( bSkipnext ){

  72224.       assert( bPreserve && (pCur->iPage==iCellDepth || CORRUPT_DB) );

  72225.       assert( pPage==pCur->pPage || CORRUPT_DB );

  72226.       assert( (pPage->nCell>0 || CORRUPT_DB) && iCellIdx<=pPage->nCell );

  72227.       pCur->eState = CURSOR_SKIPNEXT;

  72228.       if( iCellIdx>=pPage->nCell ){

  72229.         pCur->skipNext = -1;

  72230.         pCur->ix = pPage->nCell-1;

  72231.       }else{

  72232.         pCur->skipNext = 1;

  72233.       }

  72234.     }else{

  72235.       rc = moveToRoot(pCur);

  72236.       if( bPreserve ){

  72237.         btreeReleaseAllCursorPages(pCur);

  72238.         pCur->eState = CURSOR_REQUIRESEEK;

  72239.       }

  72240.       if( rc==SQLITE_EMPTY ) rc = SQLITE_OK;

  72241.     }

  72242.   }

  72243.   return rc;

  72244. }

  72245. 

  72246. /*

  72247. ** Create a new BTree table.  Write into *piTable the page

  72248. ** number for the root page of the new table.

  72249. **

  72250. ** The type of type is determined by the flags parameter.  Only the

  72251. ** following values of flags are currently in use.  Other values for

  72252. ** flags might not work:

  72253. **

  72254. **     BTREE_INTKEY|BTREE_LEAFDATA     Used for SQL tables with rowid keys

  72255. **     BTREE_ZERODATA                  Used for SQL indices

  72256. */

  72257. static int btreeCreateTable(Btree *p, int *piTable, int createTabFlags){

  72258.   BtShared *pBt = p->pBt;

  72259.   MemPage *pRoot;

  72260.   Pgno pgnoRoot;

  72261.   int rc;

  72262.   int ptfFlags;          /* Page-type flage for the root page of new table */

  72263. 

  72264.   assert( sqlite3BtreeHoldsMutex(p) );

  72265.   assert( pBt->inTransaction==TRANS_WRITE );

  72266.   assert( (pBt->btsFlags & BTS_READ_ONLY)==0 );

  72267. 

  72268. #ifdef SQLITE_OMIT_AUTOVACUUM

  72269.   rc = allocateBtreePage(pBt, &pRoot, &pgnoRoot, 1, 0);

  72270.   if( rc ){

  72271.     return rc;

  72272.   }

  72273. #else

  72274.   if( pBt->autoVacuum ){

  72275.     Pgno pgnoMove;      /* Move a page here to make room for the root-page */

  72276.     MemPage *pPageMove; /* The page to move to. */

  72277. 

  72278.     /* Creating a new table may probably require moving an existing database

  72279.     ** to make room for the new tables root page. In case this page turns

  72280.     ** out to be an overflow page, delete all overflow page-map caches

  72281.     ** held by open cursors.

  72282.     */

  72283.     invalidateAllOverflowCache(pBt);

  72284. 

  72285.     /* Read the value of meta[3] from the database to determine where the

  72286.     ** root page of the new table should go. meta[3] is the largest root-page

  72287.     ** created so far, so the new root-page is (meta[3]+1).

  72288.     */

  72289.     sqlite3BtreeGetMeta(p, BTREE_LARGEST_ROOT_PAGE, &pgnoRoot);

  72290.     pgnoRoot++;

  72291. 

  72292.     /* The new root-page may not be allocated on a pointer-map page, or the

  72293.     ** PENDING_BYTE page.

  72294.     */

  72295.     while( pgnoRoot==PTRMAP_PAGENO(pBt, pgnoRoot) ||

  72296.         pgnoRoot==PENDING_BYTE_PAGE(pBt) ){

  72297.       pgnoRoot++;

  72298.     }

  72299.     assert( pgnoRoot>=3 || CORRUPT_DB );

  72300.     testcase( pgnoRoot<3 );

  72301. 

  72302.     /* Allocate a page. The page that currently resides at pgnoRoot will

  72303.     ** be moved to the allocated page (unless the allocated page happens

  72304.     ** to reside at pgnoRoot).

  72305.     */

  72306.     rc = allocateBtreePage(pBt, &pPageMove, &pgnoMove, pgnoRoot, BTALLOC_EXACT);

  72307.     if( rc!=SQLITE_OK ){

  72308.       return rc;

  72309.     }

  72310. 

  72311.     if( pgnoMove!=pgnoRoot ){

  72312.       /* pgnoRoot is the page that will be used for the root-page of

  72313.       ** the new table (assuming an error did not occur). But we were

  72314.       ** allocated pgnoMove. If required (i.e. if it was not allocated

  72315.       ** by extending the file), the current page at position pgnoMove

  72316.       ** is already journaled.

  72317.       */

  72318.       u8 eType = 0;

  72319.       Pgno iPtrPage = 0;

  72320. 

  72321.       /* Save the positions of any open cursors. This is required in

  72322.       ** case they are holding a reference to an xFetch reference

  72323.       ** corresponding to page pgnoRoot.  */

  72324.       rc = saveAllCursors(pBt, 0, 0);

  72325.       releasePage(pPageMove);

  72326.       if( rc!=SQLITE_OK ){

  72327.         return rc;

  72328.       }

  72329. 

  72330.       /* Move the page currently at pgnoRoot to pgnoMove. */

  72331.       rc = btreeGetPage(pBt, pgnoRoot, &pRoot, 0);

  72332.       if( rc!=SQLITE_OK ){

  72333.         return rc;

  72334.       }

  72335.       rc = ptrmapGet(pBt, pgnoRoot, &eType, &iPtrPage);

  72336.       if( eType==PTRMAP_ROOTPAGE || eType==PTRMAP_FREEPAGE ){

  72337.         rc = SQLITE_CORRUPT_BKPT;

  72338.       }

  72339.       if( rc!=SQLITE_OK ){

  72340.         releasePage(pRoot);

  72341.         return rc;

  72342.       }

  72343.       assert( eType!=PTRMAP_ROOTPAGE );

  72344.       assert( eType!=PTRMAP_FREEPAGE );

  72345.       rc = relocatePage(pBt, pRoot, eType, iPtrPage, pgnoMove, 0);

  72346.       releasePage(pRoot);

  72347. 

  72348.       /* Obtain the page at pgnoRoot */

  72349.       if( rc!=SQLITE_OK ){

  72350.         return rc;

  72351.       }

  72352.       rc = btreeGetPage(pBt, pgnoRoot, &pRoot, 0);

  72353.       if( rc!=SQLITE_OK ){

  72354.         return rc;

  72355.       }

  72356.       rc = sqlite3PagerWrite(pRoot->pDbPage);

  72357.       if( rc!=SQLITE_OK ){

  72358.         releasePage(pRoot);

  72359.         return rc;

  72360.       }

  72361.     }else{

  72362.       pRoot = pPageMove;

  72363.     } 

  72364. 

  72365.     /* Update the pointer-map and meta-data with the new root-page number. */

  72366.     ptrmapPut(pBt, pgnoRoot, PTRMAP_ROOTPAGE, 0, &rc);

  72367.     if( rc ){

  72368.       releasePage(pRoot);

  72369.       return rc;

  72370.     }

  72371. 

  72372.     /* When the new root page was allocated, page 1 was made writable in

  72373.     ** order either to increase the database filesize, or to decrement the

  72374.     ** freelist count.  Hence, the sqlite3BtreeUpdateMeta() call cannot fail.

  72375.     */

  72376.     assert( sqlite3PagerIswriteable(pBt->pPage1->pDbPage) );

  72377.     rc = sqlite3BtreeUpdateMeta(p, 4, pgnoRoot);

  72378.     if( NEVER(rc) ){

  72379.       releasePage(pRoot);

  72380.       return rc;

  72381.     }

  72382. 

  72383.   }else{

  72384.     rc = allocateBtreePage(pBt, &pRoot, &pgnoRoot, 1, 0);

  72385.     if( rc ) return rc;

  72386.   }

  72387. #endif

  72388.   assert( sqlite3PagerIswriteable(pRoot->pDbPage) );

  72389.   if( createTabFlags & BTREE_INTKEY ){

  72390.     ptfFlags = PTF_INTKEY | PTF_LEAFDATA | PTF_LEAF;

  72391.   }else{

  72392.     ptfFlags = PTF_ZERODATA | PTF_LEAF;

  72393.   }

  72394.   zeroPage(pRoot, ptfFlags);

  72395.   sqlite3PagerUnref(pRoot->pDbPage);

  72396.   assert( (pBt->openFlags & BTREE_SINGLE)==0 || pgnoRoot==2 );

  72397.   *piTable = (int)pgnoRoot;

  72398.   return SQLITE_OK;

  72399. }

  72400. SQLITE_PRIVATE int sqlite3BtreeCreateTable(Btree *p, int *piTable, int flags){

  72401.   int rc;

  72402.   sqlite3BtreeEnter(p);

  72403.   rc = btreeCreateTable(p, piTable, flags);

  72404.   sqlite3BtreeLeave(p);

  72405.   return rc;

  72406. }

  72407. 

  72408. /*

  72409. ** Erase the given database page and all its children.  Return

  72410. ** the page to the freelist.

  72411. */

  72412. static int clearDatabasePage(

  72413.   BtShared *pBt,           /* The BTree that contains the table */

  72414.   Pgno pgno,               /* Page number to clear */

  72415.   int freePageFlag,        /* Deallocate page if true */

  72416.   int *pnChange            /* Add number of Cells freed to this counter */

  72417. ){

  72418.   MemPage *pPage;

  72419.   int rc;

  72420.   unsigned char *pCell;

  72421.   int i;

  72422.   int hdr;

  72423.   CellInfo info;

  72424. 

  72425.   assert( sqlite3_mutex_held(pBt->mutex) );

  72426.   if( pgno>btreePagecount(pBt) ){

  72427.     return SQLITE_CORRUPT_BKPT;

  72428.   }

  72429.   rc = getAndInitPage(pBt, pgno, &pPage, 0, 0);

  72430.   if( rc ) return rc;

  72431.   if( pPage->bBusy ){

  72432.     rc = SQLITE_CORRUPT_BKPT;

  72433.     goto cleardatabasepage_out;

  72434.   }

  72435.   pPage->bBusy = 1;

  72436.   hdr = pPage->hdrOffset;

  72437.   for(i=0; i<pPage->nCell; i++){

  72438.     pCell = findCell(pPage, i);

  72439.     if( !pPage->leaf ){

  72440.       rc = clearDatabasePage(pBt, get4byte(pCell), 1, pnChange);

  72441.       if( rc ) goto cleardatabasepage_out;

  72442.     }

  72443.     rc = clearCell(pPage, pCell, &info);

  72444.     if( rc ) goto cleardatabasepage_out;

  72445.   }

  72446.   if( !pPage->leaf ){

  72447.     rc = clearDatabasePage(pBt, get4byte(&pPage->aData[hdr+8]), 1, pnChange);

  72448.     if( rc ) goto cleardatabasepage_out;

  72449.   }else if( pnChange ){

  72450.     assert( pPage->intKey || CORRUPT_DB );

  72451.     testcase( !pPage->intKey );

  72452.     *pnChange += pPage->nCell;

  72453.   }

  72454.   if( freePageFlag ){

  72455.     freePage(pPage, &rc);

  72456.   }else if( (rc = sqlite3PagerWrite(pPage->pDbPage))==0 ){

  72457.     zeroPage(pPage, pPage->aData[hdr] | PTF_LEAF);

  72458.   }

  72459. 

  72460. cleardatabasepage_out:

  72461.   pPage->bBusy = 0;

  72462.   releasePage(pPage);

  72463.   return rc;

  72464. }

  72465. 

  72466. /*

  72467. ** Delete all information from a single table in the database.  iTable is

  72468. ** the page number of the root of the table.  After this routine returns,

  72469. ** the root page is empty, but still exists.

  72470. **

  72471. ** This routine will fail with SQLITE_LOCKED if there are any open

  72472. ** read cursors on the table.  Open write cursors are moved to the

  72473. ** root of the table.

  72474. **

  72475. ** If pnChange is not NULL, then table iTable must be an intkey table. The

  72476. ** integer value pointed to by pnChange is incremented by the number of

  72477. ** entries in the table.

  72478. */

  72479. SQLITE_PRIVATE int sqlite3BtreeClearTable(Btree *p, int iTable, int *pnChange){

  72480.   int rc;

  72481.   BtShared *pBt = p->pBt;

  72482.   sqlite3BtreeEnter(p);

  72483.   assert( p->inTrans==TRANS_WRITE );

  72484. 

  72485.   rc = saveAllCursors(pBt, (Pgno)iTable, 0);

  72486. 

  72487.   if( SQLITE_OK==rc ){

  72488.     /* Invalidate all incrblob cursors open on table iTable (assuming iTable

  72489.     ** is the root of a table b-tree - if it is not, the following call is

  72490.     ** a no-op).  */

  72491.     invalidateIncrblobCursors(p, (Pgno)iTable, 0, 1);

  72492.     rc = clearDatabasePage(pBt, (Pgno)iTable, 0, pnChange);

  72493.   }

  72494.   sqlite3BtreeLeave(p);

  72495.   return rc;

  72496. }

  72497. 

  72498. /*

  72499. ** Delete all information from the single table that pCur is open on.

  72500. **

  72501. ** This routine only work for pCur on an ephemeral table.

  72502. */

  72503. SQLITE_PRIVATE int sqlite3BtreeClearTableOfCursor(BtCursor *pCur){

  72504.   return sqlite3BtreeClearTable(pCur->pBtree, pCur->pgnoRoot, 0);

  72505. }

  72506. 

  72507. /*

  72508. ** Erase all information in a table and add the root of the table to

  72509. ** the freelist.  Except, the root of the principle table (the one on

  72510. ** page 1) is never added to the freelist.

  72511. **

  72512. ** This routine will fail with SQLITE_LOCKED if there are any open

  72513. ** cursors on the table.

  72514. **

  72515. ** If AUTOVACUUM is enabled and the page at iTable is not the last

  72516. ** root page in the database file, then the last root page 

  72517. ** in the database file is moved into the slot formerly occupied by

  72518. ** iTable and that last slot formerly occupied by the last root page

  72519. ** is added to the freelist instead of iTable.  In this say, all

  72520. ** root pages are kept at the beginning of the database file, which

  72521. ** is necessary for AUTOVACUUM to work right.  *piMoved is set to the 

  72522. ** page number that used to be the last root page in the file before

  72523. ** the move.  If no page gets moved, *piMoved is set to 0.

  72524. ** The last root page is recorded in meta[3] and the value of

  72525. ** meta[3] is updated by this procedure.

  72526. */

  72527. static int btreeDropTable(Btree *p, Pgno iTable, int *piMoved){

  72528.   int rc;

  72529.   MemPage *pPage = 0;

  72530.   BtShared *pBt = p->pBt;

  72531. 

  72532.   assert( sqlite3BtreeHoldsMutex(p) );

  72533.   assert( p->inTrans==TRANS_WRITE );

  72534.   assert( iTable>=2 );

  72535.   if( iTable>btreePagecount(pBt) ){

  72536.     return SQLITE_CORRUPT_BKPT;

  72537.   }

  72538. 

  72539.   rc = btreeGetPage(pBt, (Pgno)iTable, &pPage, 0);

  72540.   if( rc ) return rc;

  72541.   rc = sqlite3BtreeClearTable(p, iTable, 0);

  72542.   if( rc ){

  72543.     releasePage(pPage);

  72544.     return rc;

  72545.   }

  72546. 

  72547.   *piMoved = 0;

  72548. 

  72549. #ifdef SQLITE_OMIT_AUTOVACUUM

  72550.   freePage(pPage, &rc);

  72551.   releasePage(pPage);

  72552. #else

  72553.   if( pBt->autoVacuum ){

  72554.     Pgno maxRootPgno;

  72555.     sqlite3BtreeGetMeta(p, BTREE_LARGEST_ROOT_PAGE, &maxRootPgno);

  72556. 

  72557.     if( iTable==maxRootPgno ){

  72558.       /* If the table being dropped is the table with the largest root-page

  72559.       ** number in the database, put the root page on the free list. 

  72560.       */

  72561.       freePage(pPage, &rc);

  72562.       releasePage(pPage);

  72563.       if( rc!=SQLITE_OK ){

  72564.         return rc;

  72565.       }

  72566.     }else{

  72567.       /* The table being dropped does not have the largest root-page

  72568.       ** number in the database. So move the page that does into the 

  72569.       ** gap left by the deleted root-page.

  72570.       */

  72571.       MemPage *pMove;

  72572.       releasePage(pPage);

  72573.       rc = btreeGetPage(pBt, maxRootPgno, &pMove, 0);

  72574.       if( rc!=SQLITE_OK ){

  72575.         return rc;

  72576.       }

  72577.       rc = relocatePage(pBt, pMove, PTRMAP_ROOTPAGE, 0, iTable, 0);

  72578.       releasePage(pMove);

  72579.       if( rc!=SQLITE_OK ){

  72580.         return rc;

  72581.       }

  72582.       pMove = 0;

  72583.       rc = btreeGetPage(pBt, maxRootPgno, &pMove, 0);

  72584.       freePage(pMove, &rc);

  72585.       releasePage(pMove);

  72586.       if( rc!=SQLITE_OK ){

  72587.         return rc;

  72588.       }

  72589.       *piMoved = maxRootPgno;

  72590.     }

  72591. 

  72592.     /* Set the new 'max-root-page' value in the database header. This

  72593.     ** is the old value less one, less one more if that happens to

  72594.     ** be a root-page number, less one again if that is the

  72595.     ** PENDING_BYTE_PAGE.

  72596.     */

  72597.     maxRootPgno--;

  72598.     while( maxRootPgno==PENDING_BYTE_PAGE(pBt)

  72599.            || PTRMAP_ISPAGE(pBt, maxRootPgno) ){

  72600.       maxRootPgno--;

  72601.     }

  72602.     assert( maxRootPgno!=PENDING_BYTE_PAGE(pBt) );

  72603. 

  72604.     rc = sqlite3BtreeUpdateMeta(p, 4, maxRootPgno);

  72605.   }else{

  72606.     freePage(pPage, &rc);

  72607.     releasePage(pPage);

  72608.   }

  72609. #endif

  72610.   return rc;  

  72611. }

  72612. SQLITE_PRIVATE int sqlite3BtreeDropTable(Btree *p, int iTable, int *piMoved){

  72613.   int rc;

  72614.   sqlite3BtreeEnter(p);

  72615.   rc = btreeDropTable(p, iTable, piMoved);

  72616.   sqlite3BtreeLeave(p);

  72617.   return rc;

  72618. }

  72619. 

  72620. 

  72621. /*

  72622. ** This function may only be called if the b-tree connection already

  72623. ** has a read or write transaction open on the database.

  72624. **

  72625. ** Read the meta-information out of a database file.  Meta[0]

  72626. ** is the number of free pages currently in the database.  Meta[1]

  72627. ** through meta[15] are available for use by higher layers.  Meta[0]

  72628. ** is read-only, the others are read/write.

  72629. ** 

  72630. ** The schema layer numbers meta values differently.  At the schema

  72631. ** layer (and the SetCookie and ReadCookie opcodes) the number of

  72632. ** free pages is not visible.  So Cookie[0] is the same as Meta[1].

  72633. **

  72634. ** This routine treats Meta[BTREE_DATA_VERSION] as a special case.  Instead

  72635. ** of reading the value out of the header, it instead loads the "DataVersion"

  72636. ** from the pager.  The BTREE_DATA_VERSION value is not actually stored in the

  72637. ** database file.  It is a number computed by the pager.  But its access

  72638. ** pattern is the same as header meta values, and so it is convenient to

  72639. ** read it from this routine.

  72640. */

  72641. SQLITE_PRIVATE void sqlite3BtreeGetMeta(Btree *p, int idx, u32 *pMeta){

  72642.   BtShared *pBt = p->pBt;

  72643. 

  72644.   sqlite3BtreeEnter(p);

  72645.   assert( p->inTrans>TRANS_NONE );

  72646.   assert( SQLITE_OK==querySharedCacheTableLock(p, MASTER_ROOT, READ_LOCK) );

  72647.   assert( pBt->pPage1 );

  72648.   assert( idx>=0 && idx<=15 );

  72649. 

  72650.   if( idx==BTREE_DATA_VERSION ){

  72651.     *pMeta = sqlite3PagerDataVersion(pBt->pPager) + p->iDataVersion;

  72652.   }else{

  72653.     *pMeta = get4byte(&pBt->pPage1->aData[36 + idx*4]);

  72654.   }

  72655. 

  72656.   /* If auto-vacuum is disabled in this build and this is an auto-vacuum

  72657.   ** database, mark the database as read-only.  */

  72658. #ifdef SQLITE_OMIT_AUTOVACUUM

  72659.   if( idx==BTREE_LARGEST_ROOT_PAGE && *pMeta>0 ){

  72660.     pBt->btsFlags |= BTS_READ_ONLY;

  72661.   }

  72662. #endif

  72663. 

  72664.   sqlite3BtreeLeave(p);

  72665. }

  72666. 

  72667. /*

  72668. ** Write meta-information back into the database.  Meta[0] is

  72669. ** read-only and may not be written.

  72670. */

  72671. SQLITE_PRIVATE int sqlite3BtreeUpdateMeta(Btree *p, int idx, u32 iMeta){

  72672.   BtShared *pBt = p->pBt;

  72673.   unsigned char *pP1;

  72674.   int rc;

  72675.   assert( idx>=1 && idx<=15 );

  72676.   sqlite3BtreeEnter(p);

  72677.   assert( p->inTrans==TRANS_WRITE );

  72678.   assert( pBt->pPage1!=0 );

  72679.   pP1 = pBt->pPage1->aData;

  72680.   rc = sqlite3PagerWrite(pBt->pPage1->pDbPage);

  72681.   if( rc==SQLITE_OK ){

  72682.     put4byte(&pP1[36 + idx*4], iMeta);

  72683. #ifndef SQLITE_OMIT_AUTOVACUUM

  72684.     if( idx==BTREE_INCR_VACUUM ){

  72685.       assert( pBt->autoVacuum || iMeta==0 );

  72686.       assert( iMeta==0 || iMeta==1 );

  72687.       pBt->incrVacuum = (u8)iMeta;

  72688.     }

  72689. #endif

  72690.   }

  72691.   sqlite3BtreeLeave(p);

  72692.   return rc;

  72693. }

  72694. 

  72695. #ifndef SQLITE_OMIT_BTREECOUNT

  72696. /*

  72697. ** The first argument, pCur, is a cursor opened on some b-tree. Count the

  72698. ** number of entries in the b-tree and write the result to *pnEntry.

  72699. **

  72700. ** SQLITE_OK is returned if the operation is successfully executed. 

  72701. ** Otherwise, if an error is encountered (i.e. an IO error or database

  72702. ** corruption) an SQLite error code is returned.

  72703. */

  72704. SQLITE_PRIVATE int sqlite3BtreeCount(BtCursor *pCur, i64 *pnEntry){

  72705.   i64 nEntry = 0;                      /* Value to return in *pnEntry */

  72706.   int rc;                              /* Return code */

  72707. 

  72708.   rc = moveToRoot(pCur);

  72709.   if( rc==SQLITE_EMPTY ){

  72710.     *pnEntry = 0;

  72711.     return SQLITE_OK;

  72712.   }

  72713. 

  72714.   /* Unless an error occurs, the following loop runs one iteration for each

  72715.   ** page in the B-Tree structure (not including overflow pages). 

  72716.   */

  72717.   while( rc==SQLITE_OK ){

  72718.     int iIdx;                          /* Index of child node in parent */

  72719.     MemPage *pPage;                    /* Current page of the b-tree */

  72720. 

  72721.     /* If this is a leaf page or the tree is not an int-key tree, then 

  72722.     ** this page contains countable entries. Increment the entry counter

  72723.     ** accordingly.

  72724.     */

  72725.     pPage = pCur->pPage;

  72726.     if( pPage->leaf || !pPage->intKey ){

  72727.       nEntry += pPage->nCell;

  72728.     }

  72729. 

  72730.     /* pPage is a leaf node. This loop navigates the cursor so that it 

  72731.     ** points to the first interior cell that it points to the parent of

  72732.     ** the next page in the tree that has not yet been visited. The

  72733.     ** pCur->aiIdx[pCur->iPage] value is set to the index of the parent cell

  72734.     ** of the page, or to the number of cells in the page if the next page

  72735.     ** to visit is the right-child of its parent.

  72736.     **

  72737.     ** If all pages in the tree have been visited, return SQLITE_OK to the

  72738.     ** caller.

  72739.     */

  72740.     if( pPage->leaf ){

  72741.       do {

  72742.         if( pCur->iPage==0 ){

  72743.           /* All pages of the b-tree have been visited. Return successfully. */

  72744.           *pnEntry = nEntry;

  72745.           return moveToRoot(pCur);

  72746.         }

  72747.         moveToParent(pCur);

  72748.       }while ( pCur->ix>=pCur->pPage->nCell );

  72749. 

  72750.       pCur->ix++;

  72751.       pPage = pCur->pPage;

  72752.     }

  72753. 

  72754.     /* Descend to the child node of the cell that the cursor currently 

  72755.     ** points at. This is the right-child if (iIdx==pPage->nCell).

  72756.     */

  72757.     iIdx = pCur->ix;

  72758.     if( iIdx==pPage->nCell ){

  72759.       rc = moveToChild(pCur, get4byte(&pPage->aData[pPage->hdrOffset+8]));

  72760.     }else{

  72761.       rc = moveToChild(pCur, get4byte(findCell(pPage, iIdx)));

  72762.     }

  72763.   }

  72764. 

  72765.   /* An error has occurred. Return an error code. */

  72766.   return rc;

  72767. }

  72768. #endif

  72769. 

  72770. /*

  72771. ** Return the pager associated with a BTree.  This routine is used for

  72772. ** testing and debugging only.

  72773. */

  72774. SQLITE_PRIVATE Pager *sqlite3BtreePager(Btree *p){

  72775.   return p->pBt->pPager;

  72776. }

  72777. 

  72778. #ifndef SQLITE_OMIT_INTEGRITY_CHECK

  72779. /*

  72780. ** Append a message to the error message string.

  72781. */

  72782. static void checkAppendMsg(

  72783.   IntegrityCk *pCheck,

  72784.   const char *zFormat,

  72785.   ...

  72786. ){

  72787.   va_list ap;

  72788.   if( !pCheck->mxErr ) return;

  72789.   pCheck->mxErr--;

  72790.   pCheck->nErr++;

  72791.   va_start(ap, zFormat);

  72792.   if( pCheck->errMsg.nChar ){

  72793.     sqlite3_str_append(&pCheck->errMsg, "\n", 1);

  72794.   }

  72795.   if( pCheck->zPfx ){

  72796.     sqlite3_str_appendf(&pCheck->errMsg, pCheck->zPfx, pCheck->v1, pCheck->v2);

  72797.   }

  72798.   sqlite3_str_vappendf(&pCheck->errMsg, zFormat, ap);

  72799.   va_end(ap);

  72800.   if( pCheck->errMsg.accError==SQLITE_NOMEM ){

  72801.     pCheck->mallocFailed = 1;

  72802.   }

  72803. }

  72804. #endif /* SQLITE_OMIT_INTEGRITY_CHECK */

  72805. 

  72806. #ifndef SQLITE_OMIT_INTEGRITY_CHECK

  72807. 

  72808. /*

  72809. ** Return non-zero if the bit in the IntegrityCk.aPgRef[] array that

  72810. ** corresponds to page iPg is already set.

  72811. */

  72812. static int getPageReferenced(IntegrityCk *pCheck, Pgno iPg){

  72813.   assert( iPg<=pCheck->nPage && sizeof(pCheck->aPgRef[0])==1 );

  72814.   return (pCheck->aPgRef[iPg/8] & (1 << (iPg & 0x07)));

  72815. }

  72816. 

  72817. /*

  72818. ** Set the bit in the IntegrityCk.aPgRef[] array that corresponds to page iPg.

  72819. */

  72820. static void setPageReferenced(IntegrityCk *pCheck, Pgno iPg){

  72821.   assert( iPg<=pCheck->nPage && sizeof(pCheck->aPgRef[0])==1 );

  72822.   pCheck->aPgRef[iPg/8] |= (1 << (iPg & 0x07));

  72823. }

  72824. 

  72825. 

  72826. /*

  72827. ** Add 1 to the reference count for page iPage.  If this is the second

  72828. ** reference to the page, add an error message to pCheck->zErrMsg.

  72829. ** Return 1 if there are 2 or more references to the page and 0 if

  72830. ** if this is the first reference to the page.

  72831. **

  72832. ** Also check that the page number is in bounds.

  72833. */

  72834. static int checkRef(IntegrityCk *pCheck, Pgno iPage){

  72835.   if( iPage>pCheck->nPage || iPage==0 ){

  72836.     checkAppendMsg(pCheck, "invalid page number %d", iPage);

  72837.     return 1;

  72838.   }

  72839.   if( getPageReferenced(pCheck, iPage) ){

  72840.     checkAppendMsg(pCheck, "2nd reference to page %d", iPage);

  72841.     return 1;

  72842.   }

  72843.   setPageReferenced(pCheck, iPage);

  72844.   return 0;

  72845. }

  72846. 

  72847. #ifndef SQLITE_OMIT_AUTOVACUUM

  72848. /*

  72849. ** Check that the entry in the pointer-map for page iChild maps to 

  72850. ** page iParent, pointer type ptrType. If not, append an error message

  72851. ** to pCheck.

  72852. */

  72853. static void checkPtrmap(

  72854.   IntegrityCk *pCheck,   /* Integrity check context */

  72855.   Pgno iChild,           /* Child page number */

  72856.   u8 eType,              /* Expected pointer map type */

  72857.   Pgno iParent           /* Expected pointer map parent page number */

  72858. ){

  72859.   int rc;

  72860.   u8 ePtrmapType;

  72861.   Pgno iPtrmapParent;

  72862. 

  72863.   rc = ptrmapGet(pCheck->pBt, iChild, &ePtrmapType, &iPtrmapParent);

  72864.   if( rc!=SQLITE_OK ){

  72865.     if( rc==SQLITE_NOMEM || rc==SQLITE_IOERR_NOMEM ) pCheck->mallocFailed = 1;

  72866.     checkAppendMsg(pCheck, "Failed to read ptrmap key=%d", iChild);

  72867.     return;

  72868.   }

  72869. 

  72870.   if( ePtrmapType!=eType || iPtrmapParent!=iParent ){

  72871.     checkAppendMsg(pCheck,

  72872.       "Bad ptr map entry key=%d expected=(%d,%d) got=(%d,%d)", 

  72873.       iChild, eType, iParent, ePtrmapType, iPtrmapParent);

  72874.   }

  72875. }

  72876. #endif

  72877. 

  72878. /*

  72879. ** Check the integrity of the freelist or of an overflow page list.

  72880. ** Verify that the number of pages on the list is N.

  72881. */

  72882. static void checkList(

  72883.   IntegrityCk *pCheck,  /* Integrity checking context */

  72884.   int isFreeList,       /* True for a freelist.  False for overflow page list */

  72885.   int iPage,            /* Page number for first page in the list */

  72886.   u32 N                 /* Expected number of pages in the list */

  72887. ){

  72888.   int i;

  72889.   u32 expected = N;

  72890.   int nErrAtStart = pCheck->nErr;

  72891.   while( iPage!=0 && pCheck->mxErr ){

  72892.     DbPage *pOvflPage;

  72893.     unsigned char *pOvflData;

  72894.     if( checkRef(pCheck, iPage) ) break;

  72895.     N--;

  72896.     if( sqlite3PagerGet(pCheck->pPager, (Pgno)iPage, &pOvflPage, 0) ){

  72897.       checkAppendMsg(pCheck, "failed to get page %d", iPage);

  72898.       break;

  72899.     }

  72900.     pOvflData = (unsigned char *)sqlite3PagerGetData(pOvflPage);

  72901.     if( isFreeList ){

  72902.       u32 n = (u32)get4byte(&pOvflData[4]);

  72903. #ifndef SQLITE_OMIT_AUTOVACUUM

  72904.       if( pCheck->pBt->autoVacuum ){

  72905.         checkPtrmap(pCheck, iPage, PTRMAP_FREEPAGE, 0);

  72906.       }

  72907. #endif

  72908.       if( n>pCheck->pBt->usableSize/4-2 ){

  72909.         checkAppendMsg(pCheck,

  72910.            "freelist leaf count too big on page %d", iPage);

  72911.         N--;

  72912.       }else{

  72913.         for(i=0; i<(int)n; i++){

  72914.           Pgno iFreePage = get4byte(&pOvflData[8+i*4]);

  72915. #ifndef SQLITE_OMIT_AUTOVACUUM

  72916.           if( pCheck->pBt->autoVacuum ){

  72917.             checkPtrmap(pCheck, iFreePage, PTRMAP_FREEPAGE, 0);

  72918.           }

  72919. #endif

  72920.           checkRef(pCheck, iFreePage);

  72921.         }

  72922.         N -= n;

  72923.       }

  72924.     }

  72925. #ifndef SQLITE_OMIT_AUTOVACUUM

  72926.     else{

  72927.       /* If this database supports auto-vacuum and iPage is not the last

  72928.       ** page in this overflow list, check that the pointer-map entry for

  72929.       ** the following page matches iPage.

  72930.       */

  72931.       if( pCheck->pBt->autoVacuum && N>0 ){

  72932.         i = get4byte(pOvflData);

  72933.         checkPtrmap(pCheck, i, PTRMAP_OVERFLOW2, iPage);

  72934.       }

  72935.     }

  72936. #endif

  72937.     iPage = get4byte(pOvflData);

  72938.     sqlite3PagerUnref(pOvflPage);

  72939.   }

  72940.   if( N && nErrAtStart==pCheck->nErr ){

  72941.     checkAppendMsg(pCheck,

  72942.       "%s is %d but should be %d",

  72943.       isFreeList ? "size" : "overflow list length",

  72944.       expected-N, expected);

  72945.   }

  72946. }

  72947. #endif /* SQLITE_OMIT_INTEGRITY_CHECK */

  72948. 

  72949. /*

  72950. ** An implementation of a min-heap.

  72951. **

  72952. ** aHeap[0] is the number of elements on the heap.  aHeap[1] is the

  72953. ** root element.  The daughter nodes of aHeap[N] are aHeap[N*2]

  72954. ** and aHeap[N*2+1].

  72955. **

  72956. ** The heap property is this:  Every node is less than or equal to both

  72957. ** of its daughter nodes.  A consequence of the heap property is that the

  72958. ** root node aHeap[1] is always the minimum value currently in the heap.

  72959. **

  72960. ** The btreeHeapInsert() routine inserts an unsigned 32-bit number onto

  72961. ** the heap, preserving the heap property.  The btreeHeapPull() routine

  72962. ** removes the root element from the heap (the minimum value in the heap)

  72963. ** and then moves other nodes around as necessary to preserve the heap

  72964. ** property.

  72965. **

  72966. ** This heap is used for cell overlap and coverage testing.  Each u32

  72967. ** entry represents the span of a cell or freeblock on a btree page.  

  72968. ** The upper 16 bits are the index of the first byte of a range and the

  72969. ** lower 16 bits are the index of the last byte of that range.

  72970. */

  72971. static void btreeHeapInsert(u32 *aHeap, u32 x){

  72972.   u32 j, i = ++aHeap[0];

  72973.   aHeap[i] = x;

  72974.   while( (j = i/2)>0 && aHeap[j]>aHeap[i] ){

  72975.     x = aHeap[j];

  72976.     aHeap[j] = aHeap[i];

  72977.     aHeap[i] = x;

  72978.     i = j;

  72979.   }

  72980. }

  72981. static int btreeHeapPull(u32 *aHeap, u32 *pOut){

  72982.   u32 j, i, x;

  72983.   if( (x = aHeap[0])==0 ) return 0;

  72984.   *pOut = aHeap[1];

  72985.   aHeap[1] = aHeap[x];

  72986.   aHeap[x] = 0xffffffff;

  72987.   aHeap[0]--;

  72988.   i = 1;

  72989.   while( (j = i*2)<=aHeap[0] ){

  72990.     if( aHeap[j]>aHeap[j+1] ) j++;

  72991.     if( aHeap[i]<aHeap[j] ) break;

  72992.     x = aHeap[i];

  72993.     aHeap[i] = aHeap[j];

  72994.     aHeap[j] = x;

  72995.     i = j;

  72996.   }

  72997.   return 1;  

  72998. }

  72999. 

  73000. #ifndef SQLITE_OMIT_INTEGRITY_CHECK

  73001. /*

  73002. ** Do various sanity checks on a single page of a tree.  Return

  73003. ** the tree depth.  Root pages return 0.  Parents of root pages

  73004. ** return 1, and so forth.

  73005. ** 

  73006. ** These checks are done:

  73007. **

  73008. **      1.  Make sure that cells and freeblocks do not overlap

  73009. **          but combine to completely cover the page.

  73010. **      2.  Make sure integer cell keys are in order.

  73011. **      3.  Check the integrity of overflow pages.

  73012. **      4.  Recursively call checkTreePage on all children.

  73013. **      5.  Verify that the depth of all children is the same.

  73014. */

  73015. static int checkTreePage(

  73016.   IntegrityCk *pCheck,  /* Context for the sanity check */

  73017.   int iPage,            /* Page number of the page to check */

  73018.   i64 *piMinKey,        /* Write minimum integer primary key here */

  73019.   i64 maxKey            /* Error if integer primary key greater than this */

  73020. ){

  73021.   MemPage *pPage = 0;      /* The page being analyzed */

  73022.   int i;                   /* Loop counter */

  73023.   int rc;                  /* Result code from subroutine call */

  73024.   int depth = -1, d2;      /* Depth of a subtree */

  73025.   int pgno;                /* Page number */

  73026.   int nFrag;               /* Number of fragmented bytes on the page */

  73027.   int hdr;                 /* Offset to the page header */

  73028.   int cellStart;           /* Offset to the start of the cell pointer array */

  73029.   int nCell;               /* Number of cells */

  73030.   int doCoverageCheck = 1; /* True if cell coverage checking should be done */

  73031.   int keyCanBeEqual = 1;   /* True if IPK can be equal to maxKey

  73032.                            ** False if IPK must be strictly less than maxKey */

  73033.   u8 *data;                /* Page content */

  73034.   u8 *pCell;               /* Cell content */

  73035.   u8 *pCellIdx;            /* Next element of the cell pointer array */

  73036.   BtShared *pBt;           /* The BtShared object that owns pPage */

  73037.   u32 pc;                  /* Address of a cell */

  73038.   u32 usableSize;          /* Usable size of the page */

  73039.   u32 contentOffset;       /* Offset to the start of the cell content area */

  73040.   u32 *heap = 0;           /* Min-heap used for checking cell coverage */

  73041.   u32 x, prev = 0;         /* Next and previous entry on the min-heap */

  73042.   const char *saved_zPfx = pCheck->zPfx;

  73043.   int saved_v1 = pCheck->v1;

  73044.   int saved_v2 = pCheck->v2;

  73045.   u8 savedIsInit = 0;

  73046. 

  73047.   /* Check that the page exists

  73048.   */

  73049.   pBt = pCheck->pBt;

  73050.   usableSize = pBt->usableSize;

  73051.   if( iPage==0 ) return 0;

  73052.   if( checkRef(pCheck, iPage) ) return 0;

  73053.   pCheck->zPfx = "Page %d: ";

  73054.   pCheck->v1 = iPage;

  73055.   if( (rc = btreeGetPage(pBt, (Pgno)iPage, &pPage, 0))!=0 ){

  73056.     checkAppendMsg(pCheck,

  73057.        "unable to get the page. error code=%d", rc);

  73058.     goto end_of_check;

  73059.   }

  73060. 

  73061.   /* Clear MemPage.isInit to make sure the corruption detection code in

  73062.   ** btreeInitPage() is executed.  */

  73063.   savedIsInit = pPage->isInit;

  73064.   pPage->isInit = 0;

  73065.   if( (rc = btreeInitPage(pPage))!=0 ){

  73066.     assert( rc==SQLITE_CORRUPT );  /* The only possible error from InitPage */

  73067.     checkAppendMsg(pCheck,

  73068.                    "btreeInitPage() returns error code %d", rc);

  73069.     goto end_of_check;

  73070.   }

  73071.   if( (rc = btreeComputeFreeSpace(pPage))!=0 ){

  73072.     assert( rc==SQLITE_CORRUPT );

  73073.     checkAppendMsg(pCheck, "free space corruption", rc);

  73074.     goto end_of_check;

  73075.   }

  73076.   data = pPage->aData;

  73077.   hdr = pPage->hdrOffset;

  73078. 

  73079.   /* Set up for cell analysis */

  73080.   pCheck->zPfx = "On tree page %d cell %d: ";

  73081.   contentOffset = get2byteNotZero(&data[hdr+5]);

  73082.   assert( contentOffset<=usableSize );  /* Enforced by btreeInitPage() */

  73083. 

  73084.   /* EVIDENCE-OF: R-37002-32774 The two-byte integer at offset 3 gives the

  73085.   ** number of cells on the page. */

  73086.   nCell = get2byte(&data[hdr+3]);

  73087.   assert( pPage->nCell==nCell );

  73088. 

  73089.   /* EVIDENCE-OF: R-23882-45353 The cell pointer array of a b-tree page

  73090.   ** immediately follows the b-tree page header. */

  73091.   cellStart = hdr + 12 - 4*pPage->leaf;

  73092.   assert( pPage->aCellIdx==&data[cellStart] );

  73093.   pCellIdx = &data[cellStart + 2*(nCell-1)];

  73094. 

  73095.   if( !pPage->leaf ){

  73096.     /* Analyze the right-child page of internal pages */

  73097.     pgno = get4byte(&data[hdr+8]);

  73098. #ifndef SQLITE_OMIT_AUTOVACUUM

  73099.     if( pBt->autoVacuum ){

  73100.       pCheck->zPfx = "On page %d at right child: ";

  73101.       checkPtrmap(pCheck, pgno, PTRMAP_BTREE, iPage);

  73102.     }

  73103. #endif

  73104.     depth = checkTreePage(pCheck, pgno, &maxKey, maxKey);

  73105.     keyCanBeEqual = 0;

  73106.   }else{

  73107.     /* For leaf pages, the coverage check will occur in the same loop

  73108.     ** as the other cell checks, so initialize the heap.  */

  73109.     heap = pCheck->heap;

  73110.     heap[0] = 0;

  73111.   }

  73112. 

  73113.   /* EVIDENCE-OF: R-02776-14802 The cell pointer array consists of K 2-byte

  73114.   ** integer offsets to the cell contents. */

  73115.   for(i=nCell-1; i>=0 && pCheck->mxErr; i--){

  73116.     CellInfo info;

  73117. 

  73118.     /* Check cell size */

  73119.     pCheck->v2 = i;

  73120.     assert( pCellIdx==&data[cellStart + i*2] );

  73121.     pc = get2byteAligned(pCellIdx);

  73122.     pCellIdx -= 2;

  73123.     if( pc<contentOffset || pc>usableSize-4 ){

  73124.       checkAppendMsg(pCheck, "Offset %d out of range %d..%d",

  73125.                              pc, contentOffset, usableSize-4);

  73126.       doCoverageCheck = 0;

  73127.       continue;

  73128.     }

  73129.     pCell = &data[pc];

  73130.     pPage->xParseCell(pPage, pCell, &info);

  73131.     if( pc+info.nSize>usableSize ){

  73132.       checkAppendMsg(pCheck, "Extends off end of page");

  73133.       doCoverageCheck = 0;

  73134.       continue;

  73135.     }

  73136. 

  73137.     /* Check for integer primary key out of range */

  73138.     if( pPage->intKey ){

  73139.       if( keyCanBeEqual ? (info.nKey > maxKey) : (info.nKey >= maxKey) ){

  73140.         checkAppendMsg(pCheck, "Rowid %lld out of order", info.nKey);

  73141.       }

  73142.       maxKey = info.nKey;

  73143.       keyCanBeEqual = 0;     /* Only the first key on the page may ==maxKey */

  73144.     }

  73145. 

  73146.     /* Check the content overflow list */

  73147.     if( info.nPayload>info.nLocal ){

  73148.       u32 nPage;       /* Number of pages on the overflow chain */

  73149.       Pgno pgnoOvfl;   /* First page of the overflow chain */

  73150.       assert( pc + info.nSize - 4 <= usableSize );

  73151.       nPage = (info.nPayload - info.nLocal + usableSize - 5)/(usableSize - 4);

  73152.       pgnoOvfl = get4byte(&pCell[info.nSize - 4]);

  73153. #ifndef SQLITE_OMIT_AUTOVACUUM

  73154.       if( pBt->autoVacuum ){

  73155.         checkPtrmap(pCheck, pgnoOvfl, PTRMAP_OVERFLOW1, iPage);

  73156.       }

  73157. #endif

  73158.       checkList(pCheck, 0, pgnoOvfl, nPage);

  73159.     }

  73160. 

  73161.     if( !pPage->leaf ){

  73162.       /* Check sanity of left child page for internal pages */

  73163.       pgno = get4byte(pCell);

  73164. #ifndef SQLITE_OMIT_AUTOVACUUM

  73165.       if( pBt->autoVacuum ){

  73166.         checkPtrmap(pCheck, pgno, PTRMAP_BTREE, iPage);

  73167.       }

  73168. #endif

  73169.       d2 = checkTreePage(pCheck, pgno, &maxKey, maxKey);

  73170.       keyCanBeEqual = 0;

  73171.       if( d2!=depth ){

  73172.         checkAppendMsg(pCheck, "Child page depth differs");

  73173.         depth = d2;

  73174.       }

  73175.     }else{

  73176.       /* Populate the coverage-checking heap for leaf pages */

  73177.       btreeHeapInsert(heap, (pc<<16)|(pc+info.nSize-1));

  73178.     }

  73179.   }

  73180.   *piMinKey = maxKey;

  73181. 

  73182.   /* Check for complete coverage of the page

  73183.   */

  73184.   pCheck->zPfx = 0;

  73185.   if( doCoverageCheck && pCheck->mxErr>0 ){

  73186.     /* For leaf pages, the min-heap has already been initialized and the

  73187.     ** cells have already been inserted.  But for internal pages, that has

  73188.     ** not yet been done, so do it now */

  73189.     if( !pPage->leaf ){

  73190.       heap = pCheck->heap;

  73191.       heap[0] = 0;

  73192.       for(i=nCell-1; i>=0; i--){

  73193.         u32 size;

  73194.         pc = get2byteAligned(&data[cellStart+i*2]);

  73195.         size = pPage->xCellSize(pPage, &data[pc]);

  73196.         btreeHeapInsert(heap, (pc<<16)|(pc+size-1));

  73197.       }

  73198.     }

  73199.     /* Add the freeblocks to the min-heap

  73200.     **

  73201.     ** EVIDENCE-OF: R-20690-50594 The second field of the b-tree page header

  73202.     ** is the offset of the first freeblock, or zero if there are no

  73203.     ** freeblocks on the page. 

  73204.     */

  73205.     i = get2byte(&data[hdr+1]);

  73206.     while( i>0 ){

  73207.       int size, j;

  73208.       assert( (u32)i<=usableSize-4 ); /* Enforced by btreeComputeFreeSpace() */

  73209.       size = get2byte(&data[i+2]);

  73210.       assert( (u32)(i+size)<=usableSize ); /* due to btreeComputeFreeSpace() */

  73211.       btreeHeapInsert(heap, (((u32)i)<<16)|(i+size-1));

  73212.       /* EVIDENCE-OF: R-58208-19414 The first 2 bytes of a freeblock are a

  73213.       ** big-endian integer which is the offset in the b-tree page of the next

  73214.       ** freeblock in the chain, or zero if the freeblock is the last on the

  73215.       ** chain. */

  73216.       j = get2byte(&data[i]);

  73217.       /* EVIDENCE-OF: R-06866-39125 Freeblocks are always connected in order of

  73218.       ** increasing offset. */

  73219.       assert( j==0 || j>i+size );     /* Enforced by btreeComputeFreeSpace() */

  73220.       assert( (u32)j<=usableSize-4 ); /* Enforced by btreeComputeFreeSpace() */

  73221.       i = j;

  73222.     }

  73223.     /* Analyze the min-heap looking for overlap between cells and/or 

  73224.     ** freeblocks, and counting the number of untracked bytes in nFrag.

  73225.     ** 

  73226.     ** Each min-heap entry is of the form:    (start_address<<16)|end_address.

  73227.     ** There is an implied first entry the covers the page header, the cell

  73228.     ** pointer index, and the gap between the cell pointer index and the start

  73229.     ** of cell content.  

  73230.     **

  73231.     ** The loop below pulls entries from the min-heap in order and compares

  73232.     ** the start_address against the previous end_address.  If there is an

  73233.     ** overlap, that means bytes are used multiple times.  If there is a gap,

  73234.     ** that gap is added to the fragmentation count.

  73235.     */

  73236.     nFrag = 0;

  73237.     prev = contentOffset - 1;   /* Implied first min-heap entry */

  73238.     while( btreeHeapPull(heap,&x) ){

  73239.       if( (prev&0xffff)>=(x>>16) ){

  73240.         checkAppendMsg(pCheck,

  73241.           "Multiple uses for byte %u of page %d", x>>16, iPage);

  73242.         break;

  73243.       }else{

  73244.         nFrag += (x>>16) - (prev&0xffff) - 1;

  73245.         prev = x;

  73246.       }

  73247.     }

  73248.     nFrag += usableSize - (prev&0xffff) - 1;

  73249.     /* EVIDENCE-OF: R-43263-13491 The total number of bytes in all fragments

  73250.     ** is stored in the fifth field of the b-tree page header.

  73251.     ** EVIDENCE-OF: R-07161-27322 The one-byte integer at offset 7 gives the

  73252.     ** number of fragmented free bytes within the cell content area.

  73253.     */

  73254.     if( heap[0]==0 && nFrag!=data[hdr+7] ){

  73255.       checkAppendMsg(pCheck,

  73256.           "Fragmentation of %d bytes reported as %d on page %d",

  73257.           nFrag, data[hdr+7], iPage);

  73258.     }

  73259.   }

  73260. 

  73261. end_of_check:

  73262.   if( !doCoverageCheck ) pPage->isInit = savedIsInit;

  73263.   releasePage(pPage);

  73264.   pCheck->zPfx = saved_zPfx;

  73265.   pCheck->v1 = saved_v1;

  73266.   pCheck->v2 = saved_v2;

  73267.   return depth+1;

  73268. }

  73269. #endif /* SQLITE_OMIT_INTEGRITY_CHECK */

  73270. 

  73271. #ifndef SQLITE_OMIT_INTEGRITY_CHECK

  73272. /*

  73273. ** This routine does a complete check of the given BTree file.  aRoot[] is

  73274. ** an array of pages numbers were each page number is the root page of

  73275. ** a table.  nRoot is the number of entries in aRoot.

  73276. **

  73277. ** A read-only or read-write transaction must be opened before calling

  73278. ** this function.

  73279. **

  73280. ** Write the number of error seen in *pnErr.  Except for some memory

  73281. ** allocation errors,  an error message held in memory obtained from

  73282. ** malloc is returned if *pnErr is non-zero.  If *pnErr==0 then NULL is

  73283. ** returned.  If a memory allocation error occurs, NULL is returned.

  73284. */

  73285. SQLITE_PRIVATE char *sqlite3BtreeIntegrityCheck(

  73286.   Btree *p,     /* The btree to be checked */

  73287.   int *aRoot,   /* An array of root pages numbers for individual trees */

  73288.   int nRoot,    /* Number of entries in aRoot[] */

  73289.   int mxErr,    /* Stop reporting errors after this many */

  73290.   int *pnErr    /* Write number of errors seen to this variable */

  73291. ){

  73292.   Pgno i;

  73293.   IntegrityCk sCheck;

  73294.   BtShared *pBt = p->pBt;

  73295.   u64 savedDbFlags = pBt->db->flags;

  73296.   char zErr[100];

  73297.   VVA_ONLY( int nRef );

  73298. 

  73299.   sqlite3BtreeEnter(p);

  73300.   assert( p->inTrans>TRANS_NONE && pBt->inTransaction>TRANS_NONE );

  73301.   VVA_ONLY( nRef = sqlite3PagerRefcount(pBt->pPager) );

  73302.   assert( nRef>=0 );

  73303.   sCheck.pBt = pBt;

  73304.   sCheck.pPager = pBt->pPager;

  73305.   sCheck.nPage = btreePagecount(sCheck.pBt);

  73306.   sCheck.mxErr = mxErr;

  73307.   sCheck.nErr = 0;

  73308.   sCheck.mallocFailed = 0;

  73309.   sCheck.zPfx = 0;

  73310.   sCheck.v1 = 0;

  73311.   sCheck.v2 = 0;

  73312.   sCheck.aPgRef = 0;

  73313.   sCheck.heap = 0;

  73314.   sqlite3StrAccumInit(&sCheck.errMsg, 0, zErr, sizeof(zErr), SQLITE_MAX_LENGTH);

  73315.   sCheck.errMsg.printfFlags = SQLITE_PRINTF_INTERNAL;

  73316.   if( sCheck.nPage==0 ){

  73317.     goto integrity_ck_cleanup;

  73318.   }

  73319. 

  73320.   sCheck.aPgRef = sqlite3MallocZero((sCheck.nPage / 8)+ 1);

  73321.   if( !sCheck.aPgRef ){

  73322.     sCheck.mallocFailed = 1;

  73323.     goto integrity_ck_cleanup;

  73324.   }

  73325.   sCheck.heap = (u32*)sqlite3PageMalloc( pBt->pageSize );

  73326.   if( sCheck.heap==0 ){

  73327.     sCheck.mallocFailed = 1;

  73328.     goto integrity_ck_cleanup;

  73329.   }

  73330. 

  73331.   i = PENDING_BYTE_PAGE(pBt);

  73332.   if( i<=sCheck.nPage ) setPageReferenced(&sCheck, i);

  73333. 

  73334.   /* Check the integrity of the freelist

  73335.   */

  73336.   sCheck.zPfx = "Main freelist: ";

  73337.   checkList(&sCheck, 1, get4byte(&pBt->pPage1->aData[32]),

  73338.             get4byte(&pBt->pPage1->aData[36]));

  73339.   sCheck.zPfx = 0;

  73340. 

  73341.   /* Check all the tables.

  73342.   */

  73343. #ifndef SQLITE_OMIT_AUTOVACUUM

  73344.   if( pBt->autoVacuum ){

  73345.     int mx = 0;

  73346.     int mxInHdr;

  73347.     for(i=0; (int)i<nRoot; i++) if( mx<aRoot[i] ) mx = aRoot[i];

  73348.     mxInHdr = get4byte(&pBt->pPage1->aData[52]);

  73349.     if( mx!=mxInHdr ){

  73350.       checkAppendMsg(&sCheck,

  73351.         "max rootpage (%d) disagrees with header (%d)",

  73352.         mx, mxInHdr

  73353.       );

  73354.     }

  73355.   }else if( get4byte(&pBt->pPage1->aData[64])!=0 ){

  73356.     checkAppendMsg(&sCheck,

  73357.       "incremental_vacuum enabled with a max rootpage of zero"

  73358.     );

  73359.   }

  73360. #endif

  73361.   testcase( pBt->db->flags & SQLITE_CellSizeCk );

  73362.   pBt->db->flags &= ~(u64)SQLITE_CellSizeCk;

  73363.   for(i=0; (int)i<nRoot && sCheck.mxErr; i++){

  73364.     i64 notUsed;

  73365.     if( aRoot[i]==0 ) continue;

  73366. #ifndef SQLITE_OMIT_AUTOVACUUM

  73367.     if( pBt->autoVacuum && aRoot[i]>1 ){

  73368.       checkPtrmap(&sCheck, aRoot[i], PTRMAP_ROOTPAGE, 0);

  73369.     }

  73370. #endif

  73371.     checkTreePage(&sCheck, aRoot[i], &notUsed, LARGEST_INT64);

  73372.   }

  73373.   pBt->db->flags = savedDbFlags;

  73374. 

  73375.   /* Make sure every page in the file is referenced

  73376.   */

  73377.   for(i=1; i<=sCheck.nPage && sCheck.mxErr; i++){

  73378. #ifdef SQLITE_OMIT_AUTOVACUUM

  73379.     if( getPageReferenced(&sCheck, i)==0 ){

  73380.       checkAppendMsg(&sCheck, "Page %d is never used", i);

  73381.     }

  73382. #else

  73383.     /* If the database supports auto-vacuum, make sure no tables contain

  73384.     ** references to pointer-map pages.

  73385.     */

  73386.     if( getPageReferenced(&sCheck, i)==0 && 

  73387.        (PTRMAP_PAGENO(pBt, i)!=i || !pBt->autoVacuum) ){

  73388.       checkAppendMsg(&sCheck, "Page %d is never used", i);

  73389.     }

  73390.     if( getPageReferenced(&sCheck, i)!=0 && 

  73391.        (PTRMAP_PAGENO(pBt, i)==i && pBt->autoVacuum) ){

  73392.       checkAppendMsg(&sCheck, "Pointer map page %d is referenced", i);

  73393.     }

  73394. #endif

  73395.   }

  73396. 

  73397.   /* Clean  up and report errors.

  73398.   */

  73399. integrity_ck_cleanup:

  73400.   sqlite3PageFree(sCheck.heap);

  73401.   sqlite3_free(sCheck.aPgRef);

  73402.   if( sCheck.mallocFailed ){

  73403.     sqlite3_str_reset(&sCheck.errMsg);

  73404.     sCheck.nErr++;

  73405.   }

  73406.   *pnErr = sCheck.nErr;

  73407.   if( sCheck.nErr==0 ) sqlite3_str_reset(&sCheck.errMsg);

  73408.   /* Make sure this analysis did not leave any unref() pages. */

  73409.   assert( nRef==sqlite3PagerRefcount(pBt->pPager) );

  73410.   sqlite3BtreeLeave(p);

  73411.   return sqlite3StrAccumFinish(&sCheck.errMsg);

  73412. }

  73413. #endif /* SQLITE_OMIT_INTEGRITY_CHECK */

  73414. 

  73415. /*

  73416. ** Return the full pathname of the underlying database file.  Return

  73417. ** an empty string if the database is in-memory or a TEMP database.

  73418. **

  73419. ** The pager filename is invariant as long as the pager is

  73420. ** open so it is safe to access without the BtShared mutex.

  73421. */

  73422. SQLITE_PRIVATE const char *sqlite3BtreeGetFilename(Btree *p){

  73423.   assert( p->pBt->pPager!=0 );

  73424.   return sqlite3PagerFilename(p->pBt->pPager, 1);

  73425. }

  73426. 

  73427. /*

  73428. ** Return the pathname of the journal file for this database. The return

  73429. ** value of this routine is the same regardless of whether the journal file

  73430. ** has been created or not.

  73431. **

  73432. ** The pager journal filename is invariant as long as the pager is

  73433. ** open so it is safe to access without the BtShared mutex.

  73434. */

  73435. SQLITE_PRIVATE const char *sqlite3BtreeGetJournalname(Btree *p){

  73436.   assert( p->pBt->pPager!=0 );

  73437.   return sqlite3PagerJournalname(p->pBt->pPager);

  73438. }

  73439. 

  73440. /*

  73441. ** Return non-zero if a transaction is active.

  73442. */

  73443. SQLITE_PRIVATE int sqlite3BtreeIsInTrans(Btree *p){

  73444.   assert( p==0 || sqlite3_mutex_held(p->db->mutex) );

  73445.   return (p && (p->inTrans==TRANS_WRITE));

  73446. }

  73447. 

  73448. #ifndef SQLITE_OMIT_WAL

  73449. /*

  73450. ** Run a checkpoint on the Btree passed as the first argument.

  73451. **

  73452. ** Return SQLITE_LOCKED if this or any other connection has an open 

  73453. ** transaction on the shared-cache the argument Btree is connected to.

  73454. **

  73455. ** Parameter eMode is one of SQLITE_CHECKPOINT_PASSIVE, FULL or RESTART.

  73456. */

  73457. SQLITE_PRIVATE int sqlite3BtreeCheckpoint(Btree *p, int eMode, int *pnLog, int *pnCkpt){

  73458.   int rc = SQLITE_OK;

  73459.   if( p ){

  73460.     BtShared *pBt = p->pBt;

  73461.     sqlite3BtreeEnter(p);

  73462.     if( pBt->inTransaction!=TRANS_NONE ){

  73463.       rc = SQLITE_LOCKED;

  73464.     }else{

  73465.       rc = sqlite3PagerCheckpoint(pBt->pPager, p->db, eMode, pnLog, pnCkpt);

  73466.     }

  73467.     sqlite3BtreeLeave(p);

  73468.   }

  73469.   return rc;

  73470. }

  73471. #endif

  73472. 

  73473. /*

  73474. ** Return non-zero if a read (or write) transaction is active.

  73475. */

  73476. SQLITE_PRIVATE int sqlite3BtreeIsInReadTrans(Btree *p){

  73477.   assert( p );

  73478.   assert( sqlite3_mutex_held(p->db->mutex) );

  73479.   return p->inTrans!=TRANS_NONE;

  73480. }

  73481. 

  73482. SQLITE_PRIVATE int sqlite3BtreeIsInBackup(Btree *p){

  73483.   assert( p );

  73484.   assert( sqlite3_mutex_held(p->db->mutex) );

  73485.   return p->nBackup!=0;

  73486. }

  73487. 

  73488. /*

  73489. ** This function returns a pointer to a blob of memory associated with

  73490. ** a single shared-btree. The memory is used by client code for its own

  73491. ** purposes (for example, to store a high-level schema associated with 

  73492. ** the shared-btree). The btree layer manages reference counting issues.

  73493. **

  73494. ** The first time this is called on a shared-btree, nBytes bytes of memory

  73495. ** are allocated, zeroed, and returned to the caller. For each subsequent 

  73496. ** call the nBytes parameter is ignored and a pointer to the same blob

  73497. ** of memory returned. 

  73498. **

  73499. ** If the nBytes parameter is 0 and the blob of memory has not yet been

  73500. ** allocated, a null pointer is returned. If the blob has already been

  73501. ** allocated, it is returned as normal.

  73502. **

  73503. ** Just before the shared-btree is closed, the function passed as the 

  73504. ** xFree argument when the memory allocation was made is invoked on the 

  73505. ** blob of allocated memory. The xFree function should not call sqlite3_free()

  73506. ** on the memory, the btree layer does that.

  73507. */

  73508. SQLITE_PRIVATE void *sqlite3BtreeSchema(Btree *p, int nBytes, void(*xFree)(void *)){

  73509.   BtShared *pBt = p->pBt;

  73510.   sqlite3BtreeEnter(p);

  73511.   if( !pBt->pSchema && nBytes ){

  73512.     pBt->pSchema = sqlite3DbMallocZero(0, nBytes);

  73513.     pBt->xFreeSchema = xFree;

  73514.   }

  73515.   sqlite3BtreeLeave(p);

  73516.   return pBt->pSchema;

  73517. }

  73518. 

  73519. /*

  73520. ** Return SQLITE_LOCKED_SHAREDCACHE if another user of the same shared 

  73521. ** btree as the argument handle holds an exclusive lock on the 

  73522. ** sqlite_master table. Otherwise SQLITE_OK.

  73523. */

  73524. SQLITE_PRIVATE int sqlite3BtreeSchemaLocked(Btree *p){

  73525.   int rc;

  73526.   assert( sqlite3_mutex_held(p->db->mutex) );

  73527.   sqlite3BtreeEnter(p);

  73528.   rc = querySharedCacheTableLock(p, MASTER_ROOT, READ_LOCK);

  73529.   assert( rc==SQLITE_OK || rc==SQLITE_LOCKED_SHAREDCACHE );

  73530.   sqlite3BtreeLeave(p);

  73531.   return rc;

  73532. }

  73533. 

  73534. 

  73535. #ifndef SQLITE_OMIT_SHARED_CACHE

  73536. /*

  73537. ** Obtain a lock on the table whose root page is iTab.  The

  73538. ** lock is a write lock if isWritelock is true or a read lock

  73539. ** if it is false.

  73540. */

  73541. SQLITE_PRIVATE int sqlite3BtreeLockTable(Btree *p, int iTab, u8 isWriteLock){

  73542.   int rc = SQLITE_OK;

  73543.   assert( p->inTrans!=TRANS_NONE );

  73544.   if( p->sharable ){

  73545.     u8 lockType = READ_LOCK + isWriteLock;

  73546.     assert( READ_LOCK+1==WRITE_LOCK );

  73547.     assert( isWriteLock==0 || isWriteLock==1 );

  73548. 

  73549.     sqlite3BtreeEnter(p);

  73550.     rc = querySharedCacheTableLock(p, iTab, lockType);

  73551.     if( rc==SQLITE_OK ){

  73552.       rc = setSharedCacheTableLock(p, iTab, lockType);

  73553.     }

  73554.     sqlite3BtreeLeave(p);

  73555.   }

  73556.   return rc;

  73557. }

  73558. #endif

  73559. 

  73560. #ifndef SQLITE_OMIT_INCRBLOB

  73561. /*

  73562. ** Argument pCsr must be a cursor opened for writing on an 

  73563. ** INTKEY table currently pointing at a valid table entry. 

  73564. ** This function modifies the data stored as part of that entry.

  73565. **

  73566. ** Only the data content may only be modified, it is not possible to 

  73567. ** change the length of the data stored. If this function is called with

  73568. ** parameters that attempt to write past the end of the existing data,

  73569. ** no modifications are made and SQLITE_CORRUPT is returned.

  73570. */

  73571. SQLITE_PRIVATE int sqlite3BtreePutData(BtCursor *pCsr, u32 offset, u32 amt, void *z){

  73572.   int rc;

  73573.   assert( cursorOwnsBtShared(pCsr) );

  73574.   assert( sqlite3_mutex_held(pCsr->pBtree->db->mutex) );

  73575.   assert( pCsr->curFlags & BTCF_Incrblob );

  73576. 

  73577.   rc = restoreCursorPosition(pCsr);

  73578.   if( rc!=SQLITE_OK ){

  73579.     return rc;

  73580.   }

  73581.   assert( pCsr->eState!=CURSOR_REQUIRESEEK );

  73582.   if( pCsr->eState!=CURSOR_VALID ){

  73583.     return SQLITE_ABORT;

  73584.   }

  73585. 

  73586.   /* Save the positions of all other cursors open on this table. This is

  73587.   ** required in case any of them are holding references to an xFetch

  73588.   ** version of the b-tree page modified by the accessPayload call below.

  73589.   **

  73590.   ** Note that pCsr must be open on a INTKEY table and saveCursorPosition()

  73591.   ** and hence saveAllCursors() cannot fail on a BTREE_INTKEY table, hence

  73592.   ** saveAllCursors can only return SQLITE_OK.

  73593.   */

  73594.   VVA_ONLY(rc =) saveAllCursors(pCsr->pBt, pCsr->pgnoRoot, pCsr);

  73595.   assert( rc==SQLITE_OK );

  73596. 

  73597.   /* Check some assumptions: 

  73598.   **   (a) the cursor is open for writing,

  73599.   **   (b) there is a read/write transaction open,

  73600.   **   (c) the connection holds a write-lock on the table (if required),

  73601.   **   (d) there are no conflicting read-locks, and

  73602.   **   (e) the cursor points at a valid row of an intKey table.

  73603.   */

  73604.   if( (pCsr->curFlags & BTCF_WriteFlag)==0 ){

  73605.     return SQLITE_READONLY;

  73606.   }

  73607.   assert( (pCsr->pBt->btsFlags & BTS_READ_ONLY)==0

  73608.               && pCsr->pBt->inTransaction==TRANS_WRITE );

  73609.   assert( hasSharedCacheTableLock(pCsr->pBtree, pCsr->pgnoRoot, 0, 2) );

  73610.   assert( !hasReadConflicts(pCsr->pBtree, pCsr->pgnoRoot) );

  73611.   assert( pCsr->pPage->intKey );

  73612. 

  73613.   return accessPayload(pCsr, offset, amt, (unsigned char *)z, 1);

  73614. }

  73615. 

  73616. /* 

  73617. ** Mark this cursor as an incremental blob cursor.

  73618. */

  73619. SQLITE_PRIVATE void sqlite3BtreeIncrblobCursor(BtCursor *pCur){

  73620.   pCur->curFlags |= BTCF_Incrblob;

  73621.   pCur->pBtree->hasIncrblobCur = 1;

  73622. }

  73623. #endif

  73624. 

  73625. /*

  73626. ** Set both the "read version" (single byte at byte offset 18) and 

  73627. ** "write version" (single byte at byte offset 19) fields in the database

  73628. ** header to iVersion.

  73629. */

  73630. SQLITE_PRIVATE int sqlite3BtreeSetVersion(Btree *pBtree, int iVersion){

  73631.   BtShared *pBt = pBtree->pBt;

  73632.   int rc;                         /* Return code */

  73633.  

  73634.   assert( iVersion==1 || iVersion==2 );

  73635. 

  73636.   /* If setting the version fields to 1, do not automatically open the

  73637.   ** WAL connection, even if the version fields are currently set to 2.

  73638.   */

  73639.   pBt->btsFlags &= ~BTS_NO_WAL;

  73640.   if( iVersion==1 ) pBt->btsFlags |= BTS_NO_WAL;

  73641. 

  73642.   rc = sqlite3BtreeBeginTrans(pBtree, 0, 0);

  73643.   if( rc==SQLITE_OK ){

  73644.     u8 *aData = pBt->pPage1->aData;

  73645.     if( aData[18]!=(u8)iVersion || aData[19]!=(u8)iVersion ){

  73646.       rc = sqlite3BtreeBeginTrans(pBtree, 2, 0);

  73647.       if( rc==SQLITE_OK ){

  73648.         rc = sqlite3PagerWrite(pBt->pPage1->pDbPage);

  73649.         if( rc==SQLITE_OK ){

  73650.           aData[18] = (u8)iVersion;

  73651.           aData[19] = (u8)iVersion;

  73652.         }

  73653.       }

  73654.     }

  73655.   }

  73656. 

  73657.   pBt->btsFlags &= ~BTS_NO_WAL;

  73658.   return rc;

  73659. }

  73660. 

  73661. /*

  73662. ** Return true if the cursor has a hint specified.  This routine is

  73663. ** only used from within assert() statements

  73664. */

  73665. SQLITE_PRIVATE int sqlite3BtreeCursorHasHint(BtCursor *pCsr, unsigned int mask){

  73666.   return (pCsr->hints & mask)!=0;

  73667. }

  73668. 

  73669. /*

  73670. ** Return true if the given Btree is read-only.

  73671. */

  73672. SQLITE_PRIVATE int sqlite3BtreeIsReadonly(Btree *p){

  73673.   return (p->pBt->btsFlags & BTS_READ_ONLY)!=0;

  73674. }

  73675. 

  73676. /*

  73677. ** Return the size of the header added to each page by this module.

  73678. */

  73679. SQLITE_PRIVATE int sqlite3HeaderSizeBtree(void){ return ROUND8(sizeof(MemPage)); }

  73680. 

  73681. #if !defined(SQLITE_OMIT_SHARED_CACHE)

  73682. /*

  73683. ** Return true if the Btree passed as the only argument is sharable.

  73684. */

  73685. SQLITE_PRIVATE int sqlite3BtreeSharable(Btree *p){

  73686.   return p->sharable;

  73687. }

  73688. 

  73689. /*

  73690. ** Return the number of connections to the BtShared object accessed by

  73691. ** the Btree handle passed as the only argument. For private caches 

  73692. ** this is always 1. For shared caches it may be 1 or greater.

  73693. */

  73694. SQLITE_PRIVATE int sqlite3BtreeConnectionCount(Btree *p){

  73695.   testcase( p->sharable );

  73696.   return p->pBt->nRef;

  73697. }

  73698. #endif

  73699. 

  73700. /************** End of btree.c ***********************************************/

  73701. /************** Begin file backup.c ******************************************/

  73702. /*

  73703. ** 2009 January 28

  73704. **

  73705. ** The author disclaims copyright to this source code.  In place of

  73706. ** a legal notice, here is a blessing:

  73707. **

  73708. **    May you do good and not evil.

  73709. **    May you find forgiveness for yourself and forgive others.

  73710. **    May you share freely, never taking more than you give.

  73711. **

  73712. *************************************************************************

  73713. ** This file contains the implementation of the sqlite3_backup_XXX() 

  73714. ** API functions and the related features.

  73715. */

  73716. /* #include "sqliteInt.h" */

  73717. /* #include "btreeInt.h" */

  73718. 

  73719. /*

  73720. ** Structure allocated for each backup operation.

  73721. */

  73722. struct sqlite3_backup {

  73723.   sqlite3* pDestDb;        /* Destination database handle */

  73724.   Btree *pDest;            /* Destination b-tree file */

  73725.   u32 iDestSchema;         /* Original schema cookie in destination */

  73726.   int bDestLocked;         /* True once a write-transaction is open on pDest */

  73727. 

  73728.   Pgno iNext;              /* Page number of the next source page to copy */

  73729.   sqlite3* pSrcDb;         /* Source database handle */

  73730.   Btree *pSrc;             /* Source b-tree file */

  73731. 

  73732.   int rc;                  /* Backup process error code */

  73733. 

  73734.   /* These two variables are set by every call to backup_step(). They are

  73735.   ** read by calls to backup_remaining() and backup_pagecount().

  73736.   */

  73737.   Pgno nRemaining;         /* Number of pages left to copy */

  73738.   Pgno nPagecount;         /* Total number of pages to copy */

  73739. 

  73740.   int isAttached;          /* True once backup has been registered with pager */

  73741.   sqlite3_backup *pNext;   /* Next backup associated with source pager */

  73742. };

  73743. 

  73744. /*

  73745. ** THREAD SAFETY NOTES:

  73746. **

  73747. **   Once it has been created using backup_init(), a single sqlite3_backup

  73748. **   structure may be accessed via two groups of thread-safe entry points:

  73749. **

  73750. **     * Via the sqlite3_backup_XXX() API function backup_step() and 

  73751. **       backup_finish(). Both these functions obtain the source database

  73752. **       handle mutex and the mutex associated with the source BtShared 

  73753. **       structure, in that order.

  73754. **

  73755. **     * Via the BackupUpdate() and BackupRestart() functions, which are

  73756. **       invoked by the pager layer to report various state changes in

  73757. **       the page cache associated with the source database. The mutex

  73758. **       associated with the source database BtShared structure will always 

  73759. **       be held when either of these functions are invoked.

  73760. **

  73761. **   The other sqlite3_backup_XXX() API functions, backup_remaining() and

  73762. **   backup_pagecount() are not thread-safe functions. If they are called

  73763. **   while some other thread is calling backup_step() or backup_finish(),

  73764. **   the values returned may be invalid. There is no way for a call to

  73765. **   BackupUpdate() or BackupRestart() to interfere with backup_remaining()

  73766. **   or backup_pagecount().

  73767. **

  73768. **   Depending on the SQLite configuration, the database handles and/or

  73769. **   the Btree objects may have their own mutexes that require locking.

  73770. **   Non-sharable Btrees (in-memory databases for example), do not have

  73771. **   associated mutexes.

  73772. */

  73773. 

  73774. /*

  73775. ** Return a pointer corresponding to database zDb (i.e. "main", "temp")

  73776. ** in connection handle pDb. If such a database cannot be found, return

  73777. ** a NULL pointer and write an error message to pErrorDb.

  73778. **

  73779. ** If the "temp" database is requested, it may need to be opened by this 

  73780. ** function. If an error occurs while doing so, return 0 and write an 

  73781. ** error message to pErrorDb.

  73782. */

  73783. static Btree *findBtree(sqlite3 *pErrorDb, sqlite3 *pDb, const char *zDb){

  73784.   int i = sqlite3FindDbName(pDb, zDb);

  73785. 

  73786.   if( i==1 ){

  73787.     Parse sParse;

  73788.     int rc = 0;

  73789.     memset(&sParse, 0, sizeof(sParse));

  73790.     sParse.db = pDb;

  73791.     if( sqlite3OpenTempDatabase(&sParse) ){

  73792.       sqlite3ErrorWithMsg(pErrorDb, sParse.rc, "%s", sParse.zErrMsg);

  73793.       rc = SQLITE_ERROR;

  73794.     }

  73795.     sqlite3DbFree(pErrorDb, sParse.zErrMsg);

  73796.     sqlite3ParserReset(&sParse);

  73797.     if( rc ){

  73798.       return 0;

  73799.     }

  73800.   }

  73801. 

  73802.   if( i<0 ){

  73803.     sqlite3ErrorWithMsg(pErrorDb, SQLITE_ERROR, "unknown database %s", zDb);

  73804.     return 0;

  73805.   }

  73806. 

  73807.   return pDb->aDb[i].pBt;

  73808. }

  73809. 

  73810. /*

  73811. ** Attempt to set the page size of the destination to match the page size

  73812. ** of the source.

  73813. */

  73814. static int setDestPgsz(sqlite3_backup *p){

  73815.   int rc;

  73816.   rc = sqlite3BtreeSetPageSize(p->pDest,sqlite3BtreeGetPageSize(p->pSrc),-1,0);

  73817.   return rc;

  73818. }

  73819. 

  73820. /*

  73821. ** Check that there is no open read-transaction on the b-tree passed as the

  73822. ** second argument. If there is not, return SQLITE_OK. Otherwise, if there

  73823. ** is an open read-transaction, return SQLITE_ERROR and leave an error 

  73824. ** message in database handle db.

  73825. */

  73826. static int checkReadTransaction(sqlite3 *db, Btree *p){

  73827.   if( sqlite3BtreeIsInReadTrans(p) ){

  73828.     sqlite3ErrorWithMsg(db, SQLITE_ERROR, "destination database is in use");

  73829.     return SQLITE_ERROR;

  73830.   }

  73831.   return SQLITE_OK;

  73832. }

  73833. 

  73834. /*

  73835. ** Create an sqlite3_backup process to copy the contents of zSrcDb from

  73836. ** connection handle pSrcDb to zDestDb in pDestDb. If successful, return

  73837. ** a pointer to the new sqlite3_backup object.

  73838. **

  73839. ** If an error occurs, NULL is returned and an error code and error message

  73840. ** stored in database handle pDestDb.

  73841. */

  73842. SQLITE_API sqlite3_backup *sqlite3_backup_init(

  73843.   sqlite3* pDestDb,                     /* Database to write to */

  73844.   const char *zDestDb,                  /* Name of database within pDestDb */

  73845.   sqlite3* pSrcDb,                      /* Database connection to read from */

  73846.   const char *zSrcDb                    /* Name of database within pSrcDb */

  73847. ){

  73848.   sqlite3_backup *p;                    /* Value to return */

  73849. 

  73850. #ifdef SQLITE_ENABLE_API_ARMOR

  73851.   if( !sqlite3SafetyCheckOk(pSrcDb)||!sqlite3SafetyCheckOk(pDestDb) ){

  73852.     (void)SQLITE_MISUSE_BKPT;

  73853.     return 0;

  73854.   }

  73855. #endif

  73856. 

  73857.   /* Lock the source database handle. The destination database

  73858.   ** handle is not locked in this routine, but it is locked in

  73859.   ** sqlite3_backup_step(). The user is required to ensure that no

  73860.   ** other thread accesses the destination handle for the duration

  73861.   ** of the backup operation.  Any attempt to use the destination

  73862.   ** database connection while a backup is in progress may cause

  73863.   ** a malfunction or a deadlock.

  73864.   */

  73865.   sqlite3_mutex_enter(pSrcDb->mutex);

  73866.   sqlite3_mutex_enter(pDestDb->mutex);

  73867. 

  73868.   if( pSrcDb==pDestDb ){

  73869.     sqlite3ErrorWithMsg(

  73870.         pDestDb, SQLITE_ERROR, "source and destination must be distinct"

  73871.     );

  73872.     p = 0;

  73873.   }else {

  73874.     /* Allocate space for a new sqlite3_backup object...

  73875.     ** EVIDENCE-OF: R-64852-21591 The sqlite3_backup object is created by a

  73876.     ** call to sqlite3_backup_init() and is destroyed by a call to

  73877.     ** sqlite3_backup_finish(). */

  73878.     p = (sqlite3_backup *)sqlite3MallocZero(sizeof(sqlite3_backup));

  73879.     if( !p ){

  73880.       sqlite3Error(pDestDb, SQLITE_NOMEM_BKPT);

  73881.     }

  73882.   }

  73883. 

  73884.   /* If the allocation succeeded, populate the new object. */

  73885.   if( p ){

  73886.     p->pSrc = findBtree(pDestDb, pSrcDb, zSrcDb);

  73887.     p->pDest = findBtree(pDestDb, pDestDb, zDestDb);

  73888.     p->pDestDb = pDestDb;

  73889.     p->pSrcDb = pSrcDb;

  73890.     p->iNext = 1;

  73891.     p->isAttached = 0;

  73892. 

  73893.     if( 0==p->pSrc || 0==p->pDest 

  73894.      || checkReadTransaction(pDestDb, p->pDest)!=SQLITE_OK 

  73895.      ){

  73896.       /* One (or both) of the named databases did not exist or an OOM

  73897.       ** error was hit. Or there is a transaction open on the destination

  73898.       ** database. The error has already been written into the pDestDb 

  73899.       ** handle. All that is left to do here is free the sqlite3_backup 

  73900.       ** structure.  */

  73901.       sqlite3_free(p);

  73902.       p = 0;

  73903.     }

  73904.   }

  73905.   if( p ){

  73906.     p->pSrc->nBackup++;

  73907.   }

  73908. 

  73909.   sqlite3_mutex_leave(pDestDb->mutex);

  73910.   sqlite3_mutex_leave(pSrcDb->mutex);

  73911.   return p;

  73912. }

  73913. 

  73914. /*

  73915. ** Argument rc is an SQLite error code. Return true if this error is 

  73916. ** considered fatal if encountered during a backup operation. All errors

  73917. ** are considered fatal except for SQLITE_BUSY and SQLITE_LOCKED.

  73918. */

  73919. static int isFatalError(int rc){

  73920.   return (rc!=SQLITE_OK && rc!=SQLITE_BUSY && ALWAYS(rc!=SQLITE_LOCKED));

  73921. }

  73922. 

  73923. /*

  73924. ** Parameter zSrcData points to a buffer containing the data for 

  73925. ** page iSrcPg from the source database. Copy this data into the 

  73926. ** destination database.

  73927. */

  73928. static int backupOnePage(

  73929.   sqlite3_backup *p,              /* Backup handle */

  73930.   Pgno iSrcPg,                    /* Source database page to backup */

  73931.   const u8 *zSrcData,             /* Source database page data */

  73932.   int bUpdate                     /* True for an update, false otherwise */

  73933. ){

  73934.   Pager * const pDestPager = sqlite3BtreePager(p->pDest);

  73935.   const int nSrcPgsz = sqlite3BtreeGetPageSize(p->pSrc);

  73936.   int nDestPgsz = sqlite3BtreeGetPageSize(p->pDest);

  73937.   const int nCopy = MIN(nSrcPgsz, nDestPgsz);

  73938.   const i64 iEnd = (i64)iSrcPg*(i64)nSrcPgsz;

  73939. #ifdef SQLITE_HAS_CODEC

  73940.   /* Use BtreeGetReserveNoMutex() for the source b-tree, as although it is

  73941.   ** guaranteed that the shared-mutex is held by this thread, handle

  73942.   ** p->pSrc may not actually be the owner.  */

  73943.   int nSrcReserve = sqlite3BtreeGetReserveNoMutex(p->pSrc);

  73944.   int nDestReserve = sqlite3BtreeGetOptimalReserve(p->pDest);

  73945. #endif

  73946.   int rc = SQLITE_OK;

  73947.   i64 iOff;

  73948. 

  73949.   assert( sqlite3BtreeGetReserveNoMutex(p->pSrc)>=0 );

  73950.   assert( p->bDestLocked );

  73951.   assert( !isFatalError(p->rc) );

  73952.   assert( iSrcPg!=PENDING_BYTE_PAGE(p->pSrc->pBt) );

  73953.   assert( zSrcData );

  73954. 

  73955.   /* Catch the case where the destination is an in-memory database and the

  73956.   ** page sizes of the source and destination differ. 

  73957.   */

  73958.   if( nSrcPgsz!=nDestPgsz && sqlite3PagerIsMemdb(pDestPager) ){

  73959.     rc = SQLITE_READONLY;

  73960.   }

  73961. 

  73962. #ifdef SQLITE_HAS_CODEC

  73963.   /* Backup is not possible if the page size of the destination is changing

  73964.   ** and a codec is in use.

  73965.   */

  73966.   if( nSrcPgsz!=nDestPgsz && sqlite3PagerGetCodec(pDestPager)!=0 ){

  73967.     rc = SQLITE_READONLY;

  73968.   }

  73969. 

  73970.   /* Backup is not possible if the number of bytes of reserve space differ

  73971.   ** between source and destination.  If there is a difference, try to

  73972.   ** fix the destination to agree with the source.  If that is not possible,

  73973.   ** then the backup cannot proceed.

  73974.   */

  73975.   if( nSrcReserve!=nDestReserve ){

  73976.     u32 newPgsz = nSrcPgsz;

  73977.     rc = sqlite3PagerSetPagesize(pDestPager, &newPgsz, nSrcReserve);

  73978.     if( rc==SQLITE_OK && newPgsz!=(u32)nSrcPgsz ) rc = SQLITE_READONLY;

  73979.   }

  73980. #endif

  73981. 

  73982.   /* This loop runs once for each destination page spanned by the source 

  73983.   ** page. For each iteration, variable iOff is set to the byte offset

  73984.   ** of the destination page.

  73985.   */

  73986.   for(iOff=iEnd-(i64)nSrcPgsz; rc==SQLITE_OK && iOff<iEnd; iOff+=nDestPgsz){

  73987.     DbPage *pDestPg = 0;

  73988.     Pgno iDest = (Pgno)(iOff/nDestPgsz)+1;

  73989.     if( iDest==PENDING_BYTE_PAGE(p->pDest->pBt) ) continue;

  73990.     if( SQLITE_OK==(rc = sqlite3PagerGet(pDestPager, iDest, &pDestPg, 0))

  73991.      && SQLITE_OK==(rc = sqlite3PagerWrite(pDestPg))

  73992.     ){

  73993.       const u8 *zIn = &zSrcData[iOff%nSrcPgsz];

  73994.       u8 *zDestData = sqlite3PagerGetData(pDestPg);

  73995.       u8 *zOut = &zDestData[iOff%nDestPgsz];

  73996. 

  73997.       /* Copy the data from the source page into the destination page.

  73998.       ** Then clear the Btree layer MemPage.isInit flag. Both this module

  73999.       ** and the pager code use this trick (clearing the first byte

  74000.       ** of the page 'extra' space to invalidate the Btree layers

  74001.       ** cached parse of the page). MemPage.isInit is marked 

  74002.       ** "MUST BE FIRST" for this purpose.

  74003.       */

  74004.       memcpy(zOut, zIn, nCopy);

  74005.       ((u8 *)sqlite3PagerGetExtra(pDestPg))[0] = 0;

  74006.       if( iOff==0 && bUpdate==0 ){

  74007.         sqlite3Put4byte(&zOut[28], sqlite3BtreeLastPage(p->pSrc));

  74008.       }

  74009.     }

  74010.     sqlite3PagerUnref(pDestPg);

  74011.   }

  74012. 

  74013.   return rc;

  74014. }

  74015. 

  74016. /*

  74017. ** If pFile is currently larger than iSize bytes, then truncate it to

  74018. ** exactly iSize bytes. If pFile is not larger than iSize bytes, then

  74019. ** this function is a no-op.

  74020. **

  74021. ** Return SQLITE_OK if everything is successful, or an SQLite error 

  74022. ** code if an error occurs.

  74023. */

  74024. static int backupTruncateFile(sqlite3_file *pFile, i64 iSize){

  74025.   i64 iCurrent;

  74026.   int rc = sqlite3OsFileSize(pFile, &iCurrent);

  74027.   if( rc==SQLITE_OK && iCurrent>iSize ){

  74028.     rc = sqlite3OsTruncate(pFile, iSize);

  74029.   }

  74030.   return rc;

  74031. }

  74032. 

  74033. /*

  74034. ** Register this backup object with the associated source pager for

  74035. ** callbacks when pages are changed or the cache invalidated.

  74036. */

  74037. static void attachBackupObject(sqlite3_backup *p){

  74038.   sqlite3_backup **pp;

  74039.   assert( sqlite3BtreeHoldsMutex(p->pSrc) );

  74040.   pp = sqlite3PagerBackupPtr(sqlite3BtreePager(p->pSrc));

  74041.   p->pNext = *pp;

  74042.   *pp = p;

  74043.   p->isAttached = 1;

  74044. }

  74045. 

  74046. /*

  74047. ** Copy nPage pages from the source b-tree to the destination.

  74048. */

  74049. SQLITE_API int sqlite3_backup_step(sqlite3_backup *p, int nPage){

  74050.   int rc;

  74051.   int destMode;       /* Destination journal mode */

  74052.   int pgszSrc = 0;    /* Source page size */

  74053.   int pgszDest = 0;   /* Destination page size */

  74054. 

  74055. #ifdef SQLITE_ENABLE_API_ARMOR

  74056.   if( p==0 ) return SQLITE_MISUSE_BKPT;

  74057. #endif

  74058.   sqlite3_mutex_enter(p->pSrcDb->mutex);

  74059.   sqlite3BtreeEnter(p->pSrc);

  74060.   if( p->pDestDb ){

  74061.     sqlite3_mutex_enter(p->pDestDb->mutex);

  74062.   }

  74063. 

  74064.   rc = p->rc;

  74065.   if( !isFatalError(rc) ){

  74066.     Pager * const pSrcPager = sqlite3BtreePager(p->pSrc);     /* Source pager */

  74067.     Pager * const pDestPager = sqlite3BtreePager(p->pDest);   /* Dest pager */

  74068.     int ii;                            /* Iterator variable */

  74069.     int nSrcPage = -1;                 /* Size of source db in pages */

  74070.     int bCloseTrans = 0;               /* True if src db requires unlocking */

  74071. 

  74072.     /* If the source pager is currently in a write-transaction, return

  74073.     ** SQLITE_BUSY immediately.

  74074.     */

  74075.     if( p->pDestDb && p->pSrc->pBt->inTransaction==TRANS_WRITE ){

  74076.       rc = SQLITE_BUSY;

  74077.     }else{

  74078.       rc = SQLITE_OK;

  74079.     }

  74080. 

  74081.     /* If there is no open read-transaction on the source database, open

  74082.     ** one now. If a transaction is opened here, then it will be closed

  74083.     ** before this function exits.

  74084.     */

  74085.     if( rc==SQLITE_OK && 0==sqlite3BtreeIsInReadTrans(p->pSrc) ){

  74086.       rc = sqlite3BtreeBeginTrans(p->pSrc, 0, 0);

  74087.       bCloseTrans = 1;

  74088.     }

  74089. 

  74090.     /* If the destination database has not yet been locked (i.e. if this

  74091.     ** is the first call to backup_step() for the current backup operation),

  74092.     ** try to set its page size to the same as the source database. This

  74093.     ** is especially important on ZipVFS systems, as in that case it is

  74094.     ** not possible to create a database file that uses one page size by

  74095.     ** writing to it with another.  */

  74096.     if( p->bDestLocked==0 && rc==SQLITE_OK && setDestPgsz(p)==SQLITE_NOMEM ){

  74097.       rc = SQLITE_NOMEM;

  74098.     }

  74099. 

  74100.     /* Lock the destination database, if it is not locked already. */

  74101.     if( SQLITE_OK==rc && p->bDestLocked==0

  74102.      && SQLITE_OK==(rc = sqlite3BtreeBeginTrans(p->pDest, 2,

  74103.                                                 (int*)&p->iDestSchema)) 

  74104.     ){

  74105.       p->bDestLocked = 1;

  74106.     }

  74107. 

  74108.     /* Do not allow backup if the destination database is in WAL mode

  74109.     ** and the page sizes are different between source and destination */

  74110.     pgszSrc = sqlite3BtreeGetPageSize(p->pSrc);

  74111.     pgszDest = sqlite3BtreeGetPageSize(p->pDest);

  74112.     destMode = sqlite3PagerGetJournalMode(sqlite3BtreePager(p->pDest));

  74113.     if( SQLITE_OK==rc && destMode==PAGER_JOURNALMODE_WAL && pgszSrc!=pgszDest ){

  74114.       rc = SQLITE_READONLY;

  74115.     }

  74116.   

  74117.     /* Now that there is a read-lock on the source database, query the

  74118.     ** source pager for the number of pages in the database.

  74119.     */

  74120.     nSrcPage = (int)sqlite3BtreeLastPage(p->pSrc);

  74121.     assert( nSrcPage>=0 );

  74122.     for(ii=0; (nPage<0 || ii<nPage) && p->iNext<=(Pgno)nSrcPage && !rc; ii++){

  74123.       const Pgno iSrcPg = p->iNext;                 /* Source page number */

  74124.       if( iSrcPg!=PENDING_BYTE_PAGE(p->pSrc->pBt) ){

  74125.         DbPage *pSrcPg;                             /* Source page object */

  74126.         rc = sqlite3PagerGet(pSrcPager, iSrcPg, &pSrcPg,PAGER_GET_READONLY);

  74127.         if( rc==SQLITE_OK ){

  74128.           rc = backupOnePage(p, iSrcPg, sqlite3PagerGetData(pSrcPg), 0);

  74129.           sqlite3PagerUnref(pSrcPg);

  74130.         }

  74131.       }

  74132.       p->iNext++;

  74133.     }

  74134.     if( rc==SQLITE_OK ){

  74135.       p->nPagecount = nSrcPage;

  74136.       p->nRemaining = nSrcPage+1-p->iNext;

  74137.       if( p->iNext>(Pgno)nSrcPage ){

  74138.         rc = SQLITE_DONE;

  74139.       }else if( !p->isAttached ){

  74140.         attachBackupObject(p);

  74141.       }

  74142.     }

  74143.   

  74144.     /* Update the schema version field in the destination database. This

  74145.     ** is to make sure that the schema-version really does change in

  74146.     ** the case where the source and destination databases have the

  74147.     ** same schema version.

  74148.     */

  74149.     if( rc==SQLITE_DONE ){

  74150.       if( nSrcPage==0 ){

  74151.         rc = sqlite3BtreeNewDb(p->pDest);

  74152.         nSrcPage = 1;

  74153.       }

  74154.       if( rc==SQLITE_OK || rc==SQLITE_DONE ){

  74155.         rc = sqlite3BtreeUpdateMeta(p->pDest,1,p->iDestSchema+1);

  74156.       }

  74157.       if( rc==SQLITE_OK ){

  74158.         if( p->pDestDb ){

  74159.           sqlite3ResetAllSchemasOfConnection(p->pDestDb);

  74160.         }

  74161.         if( destMode==PAGER_JOURNALMODE_WAL ){

  74162.           rc = sqlite3BtreeSetVersion(p->pDest, 2);

  74163.         }

  74164.       }

  74165.       if( rc==SQLITE_OK ){

  74166.         int nDestTruncate;

  74167.         /* Set nDestTruncate to the final number of pages in the destination

  74168.         ** database. The complication here is that the destination page

  74169.         ** size may be different to the source page size. 

  74170.         **

  74171.         ** If the source page size is smaller than the destination page size, 

  74172.         ** round up. In this case the call to sqlite3OsTruncate() below will

  74173.         ** fix the size of the file. However it is important to call

  74174.         ** sqlite3PagerTruncateImage() here so that any pages in the 

  74175.         ** destination file that lie beyond the nDestTruncate page mark are

  74176.         ** journalled by PagerCommitPhaseOne() before they are destroyed

  74177.         ** by the file truncation.

  74178.         */

  74179.         assert( pgszSrc==sqlite3BtreeGetPageSize(p->pSrc) );

  74180.         assert( pgszDest==sqlite3BtreeGetPageSize(p->pDest) );

  74181.         if( pgszSrc<pgszDest ){

  74182.           int ratio = pgszDest/pgszSrc;

  74183.           nDestTruncate = (nSrcPage+ratio-1)/ratio;

  74184.           if( nDestTruncate==(int)PENDING_BYTE_PAGE(p->pDest->pBt) ){

  74185.             nDestTruncate--;

  74186.           }

  74187.         }else{

  74188.           nDestTruncate = nSrcPage * (pgszSrc/pgszDest);

  74189.         }

  74190.         assert( nDestTruncate>0 );

  74191. 

  74192.         if( pgszSrc<pgszDest ){

  74193.           /* If the source page-size is smaller than the destination page-size,

  74194.           ** two extra things may need to happen:

  74195.           **

  74196.           **   * The destination may need to be truncated, and

  74197.           **

  74198.           **   * Data stored on the pages immediately following the 

  74199.           **     pending-byte page in the source database may need to be

  74200.           **     copied into the destination database.

  74201.           */

  74202.           const i64 iSize = (i64)pgszSrc * (i64)nSrcPage;

  74203.           sqlite3_file * const pFile = sqlite3PagerFile(pDestPager);

  74204.           Pgno iPg;

  74205.           int nDstPage;

  74206.           i64 iOff;

  74207.           i64 iEnd;

  74208. 

  74209.           assert( pFile );

  74210.           assert( nDestTruncate==0 

  74211.               || (i64)nDestTruncate*(i64)pgszDest >= iSize || (

  74212.                 nDestTruncate==(int)(PENDING_BYTE_PAGE(p->pDest->pBt)-1)

  74213.              && iSize>=PENDING_BYTE && iSize<=PENDING_BYTE+pgszDest

  74214.           ));

  74215. 

  74216.           /* This block ensures that all data required to recreate the original

  74217.           ** database has been stored in the journal for pDestPager and the

  74218.           ** journal synced to disk. So at this point we may safely modify

  74219.           ** the database file in any way, knowing that if a power failure

  74220.           ** occurs, the original database will be reconstructed from the 

  74221.           ** journal file.  */

  74222.           sqlite3PagerPagecount(pDestPager, &nDstPage);

  74223.           for(iPg=nDestTruncate; rc==SQLITE_OK && iPg<=(Pgno)nDstPage; iPg++){

  74224.             if( iPg!=PENDING_BYTE_PAGE(p->pDest->pBt) ){

  74225.               DbPage *pPg;

  74226.               rc = sqlite3PagerGet(pDestPager, iPg, &pPg, 0);

  74227.               if( rc==SQLITE_OK ){

  74228.                 rc = sqlite3PagerWrite(pPg);

  74229.                 sqlite3PagerUnref(pPg);

  74230.               }

  74231.             }

  74232.           }

  74233.           if( rc==SQLITE_OK ){

  74234.             rc = sqlite3PagerCommitPhaseOne(pDestPager, 0, 1);

  74235.           }

  74236. 

  74237.           /* Write the extra pages and truncate the database file as required */

  74238.           iEnd = MIN(PENDING_BYTE + pgszDest, iSize);

  74239.           for(

  74240.             iOff=PENDING_BYTE+pgszSrc; 

  74241.             rc==SQLITE_OK && iOff<iEnd; 

  74242.             iOff+=pgszSrc

  74243.           ){

  74244.             PgHdr *pSrcPg = 0;

  74245.             const Pgno iSrcPg = (Pgno)((iOff/pgszSrc)+1);

  74246.             rc = sqlite3PagerGet(pSrcPager, iSrcPg, &pSrcPg, 0);

  74247.             if( rc==SQLITE_OK ){

  74248.               u8 *zData = sqlite3PagerGetData(pSrcPg);

  74249.               rc = sqlite3OsWrite(pFile, zData, pgszSrc, iOff);

  74250.             }

  74251.             sqlite3PagerUnref(pSrcPg);

  74252.           }

  74253.           if( rc==SQLITE_OK ){

  74254.             rc = backupTruncateFile(pFile, iSize);

  74255.           }

  74256. 

  74257.           /* Sync the database file to disk. */

  74258.           if( rc==SQLITE_OK ){

  74259.             rc = sqlite3PagerSync(pDestPager, 0);

  74260.           }

  74261.         }else{

  74262.           sqlite3PagerTruncateImage(pDestPager, nDestTruncate);

  74263.           rc = sqlite3PagerCommitPhaseOne(pDestPager, 0, 0);

  74264.         }

  74265.     

  74266.         /* Finish committing the transaction to the destination database. */

  74267.         if( SQLITE_OK==rc

  74268.          && SQLITE_OK==(rc = sqlite3BtreeCommitPhaseTwo(p->pDest, 0))

  74269.         ){

  74270.           rc = SQLITE_DONE;

  74271.         }

  74272.       }

  74273.     }

  74274.   

  74275.     /* If bCloseTrans is true, then this function opened a read transaction

  74276.     ** on the source database. Close the read transaction here. There is

  74277.     ** no need to check the return values of the btree methods here, as

  74278.     ** "committing" a read-only transaction cannot fail.

  74279.     */

  74280.     if( bCloseTrans ){

  74281.       TESTONLY( int rc2 );

  74282.       TESTONLY( rc2  = ) sqlite3BtreeCommitPhaseOne(p->pSrc, 0);

  74283.       TESTONLY( rc2 |= ) sqlite3BtreeCommitPhaseTwo(p->pSrc, 0);

  74284.       assert( rc2==SQLITE_OK );

  74285.     }

  74286.   

  74287.     if( rc==SQLITE_IOERR_NOMEM ){

  74288.       rc = SQLITE_NOMEM_BKPT;

  74289.     }

  74290.     p->rc = rc;

  74291.   }

  74292.   if( p->pDestDb ){

  74293.     sqlite3_mutex_leave(p->pDestDb->mutex);

  74294.   }

  74295.   sqlite3BtreeLeave(p->pSrc);

  74296.   sqlite3_mutex_leave(p->pSrcDb->mutex);

  74297.   return rc;

  74298. }

  74299. 

  74300. /*

  74301. ** Release all resources associated with an sqlite3_backup* handle.

  74302. */

  74303. SQLITE_API int sqlite3_backup_finish(sqlite3_backup *p){

  74304.   sqlite3_backup **pp;                 /* Ptr to head of pagers backup list */

  74305.   sqlite3 *pSrcDb;                     /* Source database connection */

  74306.   int rc;                              /* Value to return */

  74307. 

  74308.   /* Enter the mutexes */

  74309.   if( p==0 ) return SQLITE_OK;

  74310.   pSrcDb = p->pSrcDb;

  74311.   sqlite3_mutex_enter(pSrcDb->mutex);

  74312.   sqlite3BtreeEnter(p->pSrc);

  74313.   if( p->pDestDb ){

  74314.     sqlite3_mutex_enter(p->pDestDb->mutex);

  74315.   }

  74316. 

  74317.   /* Detach this backup from the source pager. */

  74318.   if( p->pDestDb ){

  74319.     p->pSrc->nBackup--;

  74320.   }

  74321.   if( p->isAttached ){

  74322.     pp = sqlite3PagerBackupPtr(sqlite3BtreePager(p->pSrc));

  74323.     while( *pp!=p ){

  74324.       pp = &(*pp)->pNext;

  74325.     }

  74326.     *pp = p->pNext;

  74327.   }

  74328. 

  74329.   /* If a transaction is still open on the Btree, roll it back. */

  74330.   sqlite3BtreeRollback(p->pDest, SQLITE_OK, 0);

  74331. 

  74332.   /* Set the error code of the destination database handle. */

  74333.   rc = (p->rc==SQLITE_DONE) ? SQLITE_OK : p->rc;

  74334.   if( p->pDestDb ){

  74335.     sqlite3Error(p->pDestDb, rc);

  74336. 

  74337.     /* Exit the mutexes and free the backup context structure. */

  74338.     sqlite3LeaveMutexAndCloseZombie(p->pDestDb);

  74339.   }

  74340.   sqlite3BtreeLeave(p->pSrc);

  74341.   if( p->pDestDb ){

  74342.     /* EVIDENCE-OF: R-64852-21591 The sqlite3_backup object is created by a

  74343.     ** call to sqlite3_backup_init() and is destroyed by a call to

  74344.     ** sqlite3_backup_finish(). */

  74345.     sqlite3_free(p);

  74346.   }

  74347.   sqlite3LeaveMutexAndCloseZombie(pSrcDb);

  74348.   return rc;

  74349. }

  74350. 

  74351. /*

  74352. ** Return the number of pages still to be backed up as of the most recent

  74353. ** call to sqlite3_backup_step().

  74354. */

  74355. SQLITE_API int sqlite3_backup_remaining(sqlite3_backup *p){

  74356. #ifdef SQLITE_ENABLE_API_ARMOR

  74357.   if( p==0 ){

  74358.     (void)SQLITE_MISUSE_BKPT;

  74359.     return 0;

  74360.   }

  74361. #endif

  74362.   return p->nRemaining;

  74363. }

  74364. 

  74365. /*

  74366. ** Return the total number of pages in the source database as of the most 

  74367. ** recent call to sqlite3_backup_step().

  74368. */

  74369. SQLITE_API int sqlite3_backup_pagecount(sqlite3_backup *p){

  74370. #ifdef SQLITE_ENABLE_API_ARMOR

  74371.   if( p==0 ){

  74372.     (void)SQLITE_MISUSE_BKPT;

  74373.     return 0;

  74374.   }

  74375. #endif

  74376.   return p->nPagecount;

  74377. }

  74378. 

  74379. /*

  74380. ** This function is called after the contents of page iPage of the

  74381. ** source database have been modified. If page iPage has already been 

  74382. ** copied into the destination database, then the data written to the

  74383. ** destination is now invalidated. The destination copy of iPage needs

  74384. ** to be updated with the new data before the backup operation is

  74385. ** complete.

  74386. **

  74387. ** It is assumed that the mutex associated with the BtShared object

  74388. ** corresponding to the source database is held when this function is

  74389. ** called.

  74390. */

  74391. static SQLITE_NOINLINE void backupUpdate(

  74392.   sqlite3_backup *p,

  74393.   Pgno iPage,

  74394.   const u8 *aData

  74395. ){

  74396.   assert( p!=0 );

  74397.   do{

  74398.     assert( sqlite3_mutex_held(p->pSrc->pBt->mutex) );

  74399.     if( !isFatalError(p->rc) && iPage<p->iNext ){

  74400.       /* The backup process p has already copied page iPage. But now it

  74401.       ** has been modified by a transaction on the source pager. Copy

  74402.       ** the new data into the backup.

  74403.       */

  74404.       int rc;

  74405.       assert( p->pDestDb );

  74406.       sqlite3_mutex_enter(p->pDestDb->mutex);

  74407.       rc = backupOnePage(p, iPage, aData, 1);

  74408.       sqlite3_mutex_leave(p->pDestDb->mutex);

  74409.       assert( rc!=SQLITE_BUSY && rc!=SQLITE_LOCKED );

  74410.       if( rc!=SQLITE_OK ){

  74411.         p->rc = rc;

  74412.       }

  74413.     }

  74414.   }while( (p = p->pNext)!=0 );

  74415. }

  74416. SQLITE_PRIVATE void sqlite3BackupUpdate(sqlite3_backup *pBackup, Pgno iPage, const u8 *aData){

  74417.   if( pBackup ) backupUpdate(pBackup, iPage, aData);

  74418. }

  74419. 

  74420. /*

  74421. ** Restart the backup process. This is called when the pager layer

  74422. ** detects that the database has been modified by an external database

  74423. ** connection. In this case there is no way of knowing which of the

  74424. ** pages that have been copied into the destination database are still 

  74425. ** valid and which are not, so the entire process needs to be restarted.

  74426. **

  74427. ** It is assumed that the mutex associated with the BtShared object

  74428. ** corresponding to the source database is held when this function is

  74429. ** called.

  74430. */

  74431. SQLITE_PRIVATE void sqlite3BackupRestart(sqlite3_backup *pBackup){

  74432.   sqlite3_backup *p;                   /* Iterator variable */

  74433.   for(p=pBackup; p; p=p->pNext){

  74434.     assert( sqlite3_mutex_held(p->pSrc->pBt->mutex) );

  74435.     p->iNext = 1;

  74436.   }

  74437. }

  74438. 

  74439. #ifndef SQLITE_OMIT_VACUUM

  74440. /*

  74441. ** Copy the complete content of pBtFrom into pBtTo.  A transaction

  74442. ** must be active for both files.

  74443. **

  74444. ** The size of file pTo may be reduced by this operation. If anything 

  74445. ** goes wrong, the transaction on pTo is rolled back. If successful, the 

  74446. ** transaction is committed before returning.

  74447. */

  74448. SQLITE_PRIVATE int sqlite3BtreeCopyFile(Btree *pTo, Btree *pFrom){

  74449.   int rc;

  74450.   sqlite3_file *pFd;              /* File descriptor for database pTo */

  74451.   sqlite3_backup b;

  74452.   sqlite3BtreeEnter(pTo);

  74453.   sqlite3BtreeEnter(pFrom);

  74454. 

  74455.   assert( sqlite3BtreeIsInTrans(pTo) );

  74456.   pFd = sqlite3PagerFile(sqlite3BtreePager(pTo));

  74457.   if( pFd->pMethods ){

  74458.     i64 nByte = sqlite3BtreeGetPageSize(pFrom)*(i64)sqlite3BtreeLastPage(pFrom);

  74459.     rc = sqlite3OsFileControl(pFd, SQLITE_FCNTL_OVERWRITE, &nByte);

  74460.     if( rc==SQLITE_NOTFOUND ) rc = SQLITE_OK;

  74461.     if( rc ) goto copy_finished;

  74462.   }

  74463. 

  74464.   /* Set up an sqlite3_backup object. sqlite3_backup.pDestDb must be set

  74465.   ** to 0. This is used by the implementations of sqlite3_backup_step()

  74466.   ** and sqlite3_backup_finish() to detect that they are being called

  74467.   ** from this function, not directly by the user.

  74468.   */

  74469.   memset(&b, 0, sizeof(b));

  74470.   b.pSrcDb = pFrom->db;

  74471.   b.pSrc = pFrom;

  74472.   b.pDest = pTo;

  74473.   b.iNext = 1;

  74474. 

  74475. #ifdef SQLITE_HAS_CODEC

  74476.   sqlite3PagerAlignReserve(sqlite3BtreePager(pTo), sqlite3BtreePager(pFrom));

  74477. #endif

  74478. 

  74479.   /* 0x7FFFFFFF is the hard limit for the number of pages in a database

  74480.   ** file. By passing this as the number of pages to copy to

  74481.   ** sqlite3_backup_step(), we can guarantee that the copy finishes 

  74482.   ** within a single call (unless an error occurs). The assert() statement

  74483.   ** checks this assumption - (p->rc) should be set to either SQLITE_DONE 

  74484.   ** or an error code.  */

  74485.   sqlite3_backup_step(&b, 0x7FFFFFFF);

  74486.   assert( b.rc!=SQLITE_OK );

  74487. 

  74488.   rc = sqlite3_backup_finish(&b);

  74489.   if( rc==SQLITE_OK ){

  74490.     pTo->pBt->btsFlags &= ~BTS_PAGESIZE_FIXED;

  74491.   }else{

  74492.     sqlite3PagerClearCache(sqlite3BtreePager(b.pDest));

  74493.   }

  74494. 

  74495.   assert( sqlite3BtreeIsInTrans(pTo)==0 );

  74496. copy_finished:

  74497.   sqlite3BtreeLeave(pFrom);

  74498.   sqlite3BtreeLeave(pTo);

  74499.   return rc;

  74500. }

  74501. #endif /* SQLITE_OMIT_VACUUM */

  74502. 

  74503. /************** End of backup.c **********************************************/

  74504. /************** Begin file vdbemem.c *****************************************/

  74505. /*

  74506. ** 2004 May 26

  74507. **

  74508. ** The author disclaims copyright to this source code.  In place of

  74509. ** a legal notice, here is a blessing:

  74510. **

  74511. **    May you do good and not evil.

  74512. **    May you find forgiveness for yourself and forgive others.

  74513. **    May you share freely, never taking more than you give.

  74514. **

  74515. *************************************************************************

  74516. **

  74517. ** This file contains code use to manipulate "Mem" structure.  A "Mem"

  74518. ** stores a single value in the VDBE.  Mem is an opaque structure visible

  74519. ** only within the VDBE.  Interface routines refer to a Mem using the

  74520. ** name sqlite_value

  74521. */

  74522. /* #include "sqliteInt.h" */

  74523. /* #include "vdbeInt.h" */

  74524. 

  74525. /* True if X is a power of two.  0 is considered a power of two here.

  74526. ** In other words, return true if X has at most one bit set.

  74527. */

  74528. #define ISPOWEROF2(X)  (((X)&((X)-1))==0)

  74529. 

  74530. #ifdef SQLITE_DEBUG

  74531. /*

  74532. ** Check invariants on a Mem object.

  74533. **

  74534. ** This routine is intended for use inside of assert() statements, like

  74535. ** this:    assert( sqlite3VdbeCheckMemInvariants(pMem) );

  74536. */

  74537. SQLITE_PRIVATE int sqlite3VdbeCheckMemInvariants(Mem *p){

  74538.   /* If MEM_Dyn is set then Mem.xDel!=0.  

  74539.   ** Mem.xDel might not be initialized if MEM_Dyn is clear.

  74540.   */

  74541.   assert( (p->flags & MEM_Dyn)==0 || p->xDel!=0 );

  74542. 

  74543.   /* MEM_Dyn may only be set if Mem.szMalloc==0.  In this way we

  74544.   ** ensure that if Mem.szMalloc>0 then it is safe to do

  74545.   ** Mem.z = Mem.zMalloc without having to check Mem.flags&MEM_Dyn.

  74546.   ** That saves a few cycles in inner loops. */

  74547.   assert( (p->flags & MEM_Dyn)==0 || p->szMalloc==0 );

  74548. 

  74549.   /* Cannot have more than one of MEM_Int, MEM_Real, or MEM_IntReal */

  74550.   assert( ISPOWEROF2(p->flags & (MEM_Int|MEM_Real|MEM_IntReal)) );

  74551. 

  74552.   if( p->flags & MEM_Null ){

  74553.     /* Cannot be both MEM_Null and some other type */

  74554.     assert( (p->flags & (MEM_Int|MEM_Real|MEM_Str|MEM_Blob|MEM_Agg))==0 );

  74555. 

  74556.     /* If MEM_Null is set, then either the value is a pure NULL (the usual

  74557.     ** case) or it is a pointer set using sqlite3_bind_pointer() or

  74558.     ** sqlite3_result_pointer().  If a pointer, then MEM_Term must also be

  74559.     ** set.

  74560.     */

  74561.     if( (p->flags & (MEM_Term|MEM_Subtype))==(MEM_Term|MEM_Subtype) ){

  74562.       /* This is a pointer type.  There may be a flag to indicate what to

  74563.       ** do with the pointer. */

  74564.       assert( ((p->flags&MEM_Dyn)!=0 ? 1 : 0) +

  74565.               ((p->flags&MEM_Ephem)!=0 ? 1 : 0) +

  74566.               ((p->flags&MEM_Static)!=0 ? 1 : 0) <= 1 );

  74567. 

  74568.       /* No other bits set */

  74569.       assert( (p->flags & ~(MEM_Null|MEM_Term|MEM_Subtype|MEM_FromBind

  74570.                            |MEM_Dyn|MEM_Ephem|MEM_Static))==0 );

  74571.     }else{

  74572.       /* A pure NULL might have other flags, such as MEM_Static, MEM_Dyn,

  74573.       ** MEM_Ephem, MEM_Cleared, or MEM_Subtype */

  74574.     }

  74575.   }else{

  74576.     /* The MEM_Cleared bit is only allowed on NULLs */

  74577.     assert( (p->flags & MEM_Cleared)==0 );

  74578.   }

  74579. 

  74580.   /* The szMalloc field holds the correct memory allocation size */

  74581.   assert( p->szMalloc==0

  74582.        || p->szMalloc==sqlite3DbMallocSize(p->db,p->zMalloc) );

  74583. 

  74584.   /* If p holds a string or blob, the Mem.z must point to exactly

  74585.   ** one of the following:

  74586.   **

  74587.   **   (1) Memory in Mem.zMalloc and managed by the Mem object

  74588.   **   (2) Memory to be freed using Mem.xDel

  74589.   **   (3) An ephemeral string or blob

  74590.   **   (4) A static string or blob

  74591.   */

  74592.   if( (p->flags & (MEM_Str|MEM_Blob)) && p->n>0 ){

  74593.     assert( 

  74594.       ((p->szMalloc>0 && p->z==p->zMalloc)? 1 : 0) +

  74595.       ((p->flags&MEM_Dyn)!=0 ? 1 : 0) +

  74596.       ((p->flags&MEM_Ephem)!=0 ? 1 : 0) +

  74597.       ((p->flags&MEM_Static)!=0 ? 1 : 0) == 1

  74598.     );

  74599.   }

  74600.   return 1;

  74601. }

  74602. #endif

  74603. 

  74604. /*

  74605. ** Render a Mem object which is one of MEM_Int, MEM_Real, or MEM_IntReal

  74606. ** into a buffer.

  74607. */

  74608. static void vdbeMemRenderNum(int sz, char *zBuf, Mem *p){

  74609.   StrAccum acc;

  74610.   assert( p->flags & (MEM_Int|MEM_Real|MEM_IntReal) );

  74611.   sqlite3StrAccumInit(&acc, 0, zBuf, sz, 0);

  74612.   if( p->flags & MEM_Int ){

  74613.     sqlite3_str_appendf(&acc, "%lld", p->u.i);

  74614.   }else if( p->flags & MEM_IntReal ){

  74615.     sqlite3_str_appendf(&acc, "%!.15g", (double)p->u.i);

  74616.   }else{

  74617.     sqlite3_str_appendf(&acc, "%!.15g", p->u.r);

  74618.   }

  74619.   assert( acc.zText==zBuf && acc.mxAlloc<=0 );

  74620.   zBuf[acc.nChar] = 0; /* Fast version of sqlite3StrAccumFinish(&acc) */

  74621. }

  74622. 

  74623. #ifdef SQLITE_DEBUG

  74624. /*

  74625. ** Validity checks on pMem.  pMem holds a string.

  74626. **

  74627. ** (1) Check that string value of pMem agrees with its integer or real value.

  74628. ** (2) Check that the string is correctly zero terminated

  74629. **

  74630. ** A single int or real value always converts to the same strings.  But

  74631. ** many different strings can be converted into the same int or real.

  74632. ** If a table contains a numeric value and an index is based on the

  74633. ** corresponding string value, then it is important that the string be

  74634. ** derived from the numeric value, not the other way around, to ensure

  74635. ** that the index and table are consistent.  See ticket

  74636. ** https://www.sqlite.org/src/info/343634942dd54ab (2018-01-31) for

  74637. ** an example.

  74638. **

  74639. ** This routine looks at pMem to verify that if it has both a numeric

  74640. ** representation and a string representation then the string rep has

  74641. ** been derived from the numeric and not the other way around.  It returns

  74642. ** true if everything is ok and false if there is a problem.

  74643. **

  74644. ** This routine is for use inside of assert() statements only.

  74645. */

  74646. SQLITE_PRIVATE int sqlite3VdbeMemValidStrRep(Mem *p){

  74647.   char zBuf[100];

  74648.   char *z;

  74649.   int i, j, incr;

  74650.   if( (p->flags & MEM_Str)==0 ) return 1;

  74651.   if( p->flags & MEM_Term ){

  74652.     /* Insure that the string is properly zero-terminated.  Pay particular

  74653.     ** attention to the case where p->n is odd */

  74654.     if( p->szMalloc>0 && p->z==p->zMalloc ){

  74655.       assert( p->enc==SQLITE_UTF8 || p->szMalloc >= ((p->n+1)&~1)+2 );

  74656.       assert( p->enc!=SQLITE_UTF8 || p->szMalloc >= p->n+1 );

  74657.     }

  74658.     assert( p->z[p->n]==0 );

  74659.     assert( p->enc==SQLITE_UTF8 || p->z[(p->n+1)&~1]==0 );

  74660.     assert( p->enc==SQLITE_UTF8 || p->z[((p->n+1)&~1)+1]==0 );

  74661.   }

  74662.   if( (p->flags & (MEM_Int|MEM_Real|MEM_IntReal))==0 ) return 1;

  74663.   vdbeMemRenderNum(sizeof(zBuf), zBuf, p);

  74664.   z = p->z;

  74665.   i = j = 0;

  74666.   incr = 1;

  74667.   if( p->enc!=SQLITE_UTF8 ){

  74668.     incr = 2;

  74669.     if( p->enc==SQLITE_UTF16BE ) z++;

  74670.   }

  74671.   while( zBuf[j] ){

  74672.     if( zBuf[j++]!=z[i] ) return 0;

  74673.     i += incr;

  74674.   }

  74675.   return 1;

  74676. }

  74677. #endif /* SQLITE_DEBUG */

  74678. 

  74679. /*

  74680. ** If pMem is an object with a valid string representation, this routine

  74681. ** ensures the internal encoding for the string representation is

  74682. ** 'desiredEnc', one of SQLITE_UTF8, SQLITE_UTF16LE or SQLITE_UTF16BE.

  74683. **

  74684. ** If pMem is not a string object, or the encoding of the string

  74685. ** representation is already stored using the requested encoding, then this

  74686. ** routine is a no-op.

  74687. **

  74688. ** SQLITE_OK is returned if the conversion is successful (or not required).

  74689. ** SQLITE_NOMEM may be returned if a malloc() fails during conversion

  74690. ** between formats.

  74691. */

  74692. SQLITE_PRIVATE int sqlite3VdbeChangeEncoding(Mem *pMem, int desiredEnc){

  74693. #ifndef SQLITE_OMIT_UTF16

  74694.   int rc;

  74695. #endif

  74696.   assert( !sqlite3VdbeMemIsRowSet(pMem) );

  74697.   assert( desiredEnc==SQLITE_UTF8 || desiredEnc==SQLITE_UTF16LE

  74698.            || desiredEnc==SQLITE_UTF16BE );

  74699.   if( !(pMem->flags&MEM_Str) || pMem->enc==desiredEnc ){

  74700.     return SQLITE_OK;

  74701.   }

  74702.   assert( pMem->db==0 || sqlite3_mutex_held(pMem->db->mutex) );

  74703. #ifdef SQLITE_OMIT_UTF16

  74704.   return SQLITE_ERROR;

  74705. #else

  74706. 

  74707.   /* MemTranslate() may return SQLITE_OK or SQLITE_NOMEM. If NOMEM is returned,

  74708.   ** then the encoding of the value may not have changed.

  74709.   */

  74710.   rc = sqlite3VdbeMemTranslate(pMem, (u8)desiredEnc);

  74711.   assert(rc==SQLITE_OK    || rc==SQLITE_NOMEM);

  74712.   assert(rc==SQLITE_OK    || pMem->enc!=desiredEnc);

  74713.   assert(rc==SQLITE_NOMEM || pMem->enc==desiredEnc);

  74714.   return rc;

  74715. #endif

  74716. }

  74717. 

  74718. /*

  74719. ** Make sure pMem->z points to a writable allocation of at least n bytes.

  74720. **

  74721. ** If the bPreserve argument is true, then copy of the content of

  74722. ** pMem->z into the new allocation.  pMem must be either a string or

  74723. ** blob if bPreserve is true.  If bPreserve is false, any prior content

  74724. ** in pMem->z is discarded.

  74725. */

  74726. SQLITE_PRIVATE SQLITE_NOINLINE int sqlite3VdbeMemGrow(Mem *pMem, int n, int bPreserve){

  74727.   assert( sqlite3VdbeCheckMemInvariants(pMem) );

  74728.   assert( !sqlite3VdbeMemIsRowSet(pMem) );

  74729.   testcase( pMem->db==0 );

  74730. 

  74731.   /* If the bPreserve flag is set to true, then the memory cell must already

  74732.   ** contain a valid string or blob value.  */

  74733.   assert( bPreserve==0 || pMem->flags&(MEM_Blob|MEM_Str) );

  74734.   testcase( bPreserve && pMem->z==0 );

  74735. 

  74736.   assert( pMem->szMalloc==0

  74737.        || pMem->szMalloc==sqlite3DbMallocSize(pMem->db, pMem->zMalloc) );

  74738.   if( pMem->szMalloc>0 && bPreserve && pMem->z==pMem->zMalloc ){

  74739.     pMem->z = pMem->zMalloc = sqlite3DbReallocOrFree(pMem->db, pMem->z, n);

  74740.     bPreserve = 0;

  74741.   }else{

  74742.     if( pMem->szMalloc>0 ) sqlite3DbFreeNN(pMem->db, pMem->zMalloc);

  74743.     pMem->zMalloc = sqlite3DbMallocRaw(pMem->db, n);

  74744.   }

  74745.   if( pMem->zMalloc==0 ){

  74746.     sqlite3VdbeMemSetNull(pMem);

  74747.     pMem->z = 0;

  74748.     pMem->szMalloc = 0;

  74749.     return SQLITE_NOMEM_BKPT;

  74750.   }else{

  74751.     pMem->szMalloc = sqlite3DbMallocSize(pMem->db, pMem->zMalloc);

  74752.   }

  74753. 

  74754.   if( bPreserve && pMem->z ){

  74755.     assert( pMem->z!=pMem->zMalloc );

  74756.     memcpy(pMem->zMalloc, pMem->z, pMem->n);

  74757.   }

  74758.   if( (pMem->flags&MEM_Dyn)!=0 ){

  74759.     assert( pMem->xDel!=0 && pMem->xDel!=SQLITE_DYNAMIC );

  74760.     pMem->xDel((void *)(pMem->z));

  74761.   }

  74762. 

  74763.   pMem->z = pMem->zMalloc;

  74764.   pMem->flags &= ~(MEM_Dyn|MEM_Ephem|MEM_Static);

  74765.   return SQLITE_OK;

  74766. }

  74767. 

  74768. /*

  74769. ** Change the pMem->zMalloc allocation to be at least szNew bytes.

  74770. ** If pMem->zMalloc already meets or exceeds the requested size, this

  74771. ** routine is a no-op.

  74772. **

  74773. ** Any prior string or blob content in the pMem object may be discarded.

  74774. ** The pMem->xDel destructor is called, if it exists.  Though MEM_Str

  74775. ** and MEM_Blob values may be discarded, MEM_Int, MEM_Real, MEM_IntReal,

  74776. ** and MEM_Null values are preserved.

  74777. **

  74778. ** Return SQLITE_OK on success or an error code (probably SQLITE_NOMEM)

  74779. ** if unable to complete the resizing.

  74780. */

  74781. SQLITE_PRIVATE int sqlite3VdbeMemClearAndResize(Mem *pMem, int szNew){

  74782.   assert( CORRUPT_DB || szNew>0 );

  74783.   assert( (pMem->flags & MEM_Dyn)==0 || pMem->szMalloc==0 );

  74784.   if( pMem->szMalloc<szNew ){

  74785.     return sqlite3VdbeMemGrow(pMem, szNew, 0);

  74786.   }

  74787.   assert( (pMem->flags & MEM_Dyn)==0 );

  74788.   pMem->z = pMem->zMalloc;

  74789.   pMem->flags &= (MEM_Null|MEM_Int|MEM_Real|MEM_IntReal);

  74790.   return SQLITE_OK;

  74791. }

  74792. 

  74793. /*

  74794. ** It is already known that pMem contains an unterminated string.

  74795. ** Add the zero terminator.

  74796. **

  74797. ** Three bytes of zero are added.  In this way, there is guaranteed

  74798. ** to be a double-zero byte at an even byte boundary in order to

  74799. ** terminate a UTF16 string, even if the initial size of the buffer

  74800. ** is an odd number of bytes.

  74801. */

  74802. static SQLITE_NOINLINE int vdbeMemAddTerminator(Mem *pMem){

  74803.   if( sqlite3VdbeMemGrow(pMem, pMem->n+3, 1) ){

  74804.     return SQLITE_NOMEM_BKPT;

  74805.   }

  74806.   pMem->z[pMem->n] = 0;

  74807.   pMem->z[pMem->n+1] = 0;

  74808.   pMem->z[pMem->n+2] = 0;

  74809.   pMem->flags |= MEM_Term;

  74810.   return SQLITE_OK;

  74811. }

  74812. 

  74813. /*

  74814. ** Change pMem so that its MEM_Str or MEM_Blob value is stored in

  74815. ** MEM.zMalloc, where it can be safely written.

  74816. **

  74817. ** Return SQLITE_OK on success or SQLITE_NOMEM if malloc fails.

  74818. */

  74819. SQLITE_PRIVATE int sqlite3VdbeMemMakeWriteable(Mem *pMem){

  74820.   assert( pMem->db==0 || sqlite3_mutex_held(pMem->db->mutex) );

  74821.   assert( !sqlite3VdbeMemIsRowSet(pMem) );

  74822.   if( (pMem->flags & (MEM_Str|MEM_Blob))!=0 ){

  74823.     if( ExpandBlob(pMem) ) return SQLITE_NOMEM;

  74824.     if( pMem->szMalloc==0 || pMem->z!=pMem->zMalloc ){

  74825.       int rc = vdbeMemAddTerminator(pMem);

  74826.       if( rc ) return rc;

  74827.     }

  74828.   }

  74829.   pMem->flags &= ~MEM_Ephem;

  74830. #ifdef SQLITE_DEBUG

  74831.   pMem->pScopyFrom = 0;

  74832. #endif

  74833. 

  74834.   return SQLITE_OK;

  74835. }

  74836. 

  74837. /*

  74838. ** If the given Mem* has a zero-filled tail, turn it into an ordinary

  74839. ** blob stored in dynamically allocated space.

  74840. */

  74841. #ifndef SQLITE_OMIT_INCRBLOB

  74842. SQLITE_PRIVATE int sqlite3VdbeMemExpandBlob(Mem *pMem){

  74843.   int nByte;

  74844.   assert( pMem->flags & MEM_Zero );

  74845.   assert( (pMem->flags&MEM_Blob)!=0 || MemNullNochng(pMem) );

  74846.   testcase( sqlite3_value_nochange(pMem) );

  74847.   assert( !sqlite3VdbeMemIsRowSet(pMem) );

  74848.   assert( pMem->db==0 || sqlite3_mutex_held(pMem->db->mutex) );

  74849. 

  74850.   /* Set nByte to the number of bytes required to store the expanded blob. */

  74851.   nByte = pMem->n + pMem->u.nZero;

  74852.   if( nByte<=0 ){

  74853.     if( (pMem->flags & MEM_Blob)==0 ) return SQLITE_OK;

  74854.     nByte = 1;

  74855.   }

  74856.   if( sqlite3VdbeMemGrow(pMem, nByte, 1) ){

  74857.     return SQLITE_NOMEM_BKPT;

  74858.   }

  74859. 

  74860.   memset(&pMem->z[pMem->n], 0, pMem->u.nZero);

  74861.   pMem->n += pMem->u.nZero;

  74862.   pMem->flags &= ~(MEM_Zero|MEM_Term);

  74863.   return SQLITE_OK;

  74864. }

  74865. #endif

  74866. 

  74867. /*

  74868. ** Make sure the given Mem is \u0000 terminated.

  74869. */

  74870. SQLITE_PRIVATE int sqlite3VdbeMemNulTerminate(Mem *pMem){

  74871.   assert( pMem->db==0 || sqlite3_mutex_held(pMem->db->mutex) );

  74872.   testcase( (pMem->flags & (MEM_Term|MEM_Str))==(MEM_Term|MEM_Str) );

  74873.   testcase( (pMem->flags & (MEM_Term|MEM_Str))==0 );

  74874.   if( (pMem->flags & (MEM_Term|MEM_Str))!=MEM_Str ){

  74875.     return SQLITE_OK;   /* Nothing to do */

  74876.   }else{

  74877.     return vdbeMemAddTerminator(pMem);

  74878.   }

  74879. }

  74880. 

  74881. /*

  74882. ** Add MEM_Str to the set of representations for the given Mem.  This

  74883. ** routine is only called if pMem is a number of some kind, not a NULL

  74884. ** or a BLOB.

  74885. **

  74886. ** Existing representations MEM_Int, MEM_Real, or MEM_IntReal are invalidated

  74887. ** if bForce is true but are retained if bForce is false.

  74888. **

  74889. ** A MEM_Null value will never be passed to this function. This function is

  74890. ** used for converting values to text for returning to the user (i.e. via

  74891. ** sqlite3_value_text()), or for ensuring that values to be used as btree

  74892. ** keys are strings. In the former case a NULL pointer is returned the

  74893. ** user and the latter is an internal programming error.

  74894. */

  74895. SQLITE_PRIVATE int sqlite3VdbeMemStringify(Mem *pMem, u8 enc, u8 bForce){

  74896.   const int nByte = 32;

  74897. 

  74898.   assert( pMem->db==0 || sqlite3_mutex_held(pMem->db->mutex) );

  74899.   assert( !(pMem->flags&MEM_Zero) );

  74900.   assert( !(pMem->flags&(MEM_Str|MEM_Blob)) );

  74901.   assert( pMem->flags&(MEM_Int|MEM_Real|MEM_IntReal) );

  74902.   assert( !sqlite3VdbeMemIsRowSet(pMem) );

  74903.   assert( EIGHT_BYTE_ALIGNMENT(pMem) );

  74904. 

  74905. 

  74906.   if( sqlite3VdbeMemClearAndResize(pMem, nByte) ){

  74907.     pMem->enc = 0;

  74908.     return SQLITE_NOMEM_BKPT;

  74909.   }

  74910. 

  74911.   vdbeMemRenderNum(nByte, pMem->z, pMem);

  74912.   assert( pMem->z!=0 );

  74913.   pMem->n = sqlite3Strlen30NN(pMem->z);

  74914.   pMem->enc = SQLITE_UTF8;

  74915.   pMem->flags |= MEM_Str|MEM_Term;

  74916.   if( bForce ) pMem->flags &= ~(MEM_Int|MEM_Real|MEM_IntReal);

  74917.   sqlite3VdbeChangeEncoding(pMem, enc);

  74918.   return SQLITE_OK;

  74919. }

  74920. 

  74921. /*

  74922. ** Memory cell pMem contains the context of an aggregate function.

  74923. ** This routine calls the finalize method for that function.  The

  74924. ** result of the aggregate is stored back into pMem.

  74925. **

  74926. ** Return SQLITE_ERROR if the finalizer reports an error.  SQLITE_OK

  74927. ** otherwise.

  74928. */

  74929. SQLITE_PRIVATE int sqlite3VdbeMemFinalize(Mem *pMem, FuncDef *pFunc){

  74930.   sqlite3_context ctx;

  74931.   Mem t;

  74932.   assert( pFunc!=0 );

  74933.   assert( pFunc->xFinalize!=0 );

  74934.   assert( (pMem->flags & MEM_Null)!=0 || pFunc==pMem->u.pDef );

  74935.   assert( pMem->db==0 || sqlite3_mutex_held(pMem->db->mutex) );

  74936.   memset(&ctx, 0, sizeof(ctx));

  74937.   memset(&t, 0, sizeof(t));

  74938.   t.flags = MEM_Null;

  74939.   t.db = pMem->db;

  74940.   ctx.pOut = &t;

  74941.   ctx.pMem = pMem;

  74942.   ctx.pFunc = pFunc;

  74943.   pFunc->xFinalize(&ctx); /* IMP: R-24505-23230 */

  74944.   assert( (pMem->flags & MEM_Dyn)==0 );

  74945.   if( pMem->szMalloc>0 ) sqlite3DbFreeNN(pMem->db, pMem->zMalloc);

  74946.   memcpy(pMem, &t, sizeof(t));

  74947.   return ctx.isError;

  74948. }

  74949. 

  74950. /*

  74951. ** Memory cell pAccum contains the context of an aggregate function.

  74952. ** This routine calls the xValue method for that function and stores

  74953. ** the results in memory cell pMem.

  74954. **

  74955. ** SQLITE_ERROR is returned if xValue() reports an error. SQLITE_OK 

  74956. ** otherwise.

  74957. */

  74958. #ifndef SQLITE_OMIT_WINDOWFUNC

  74959. SQLITE_PRIVATE int sqlite3VdbeMemAggValue(Mem *pAccum, Mem *pOut, FuncDef *pFunc){

  74960.   sqlite3_context ctx;

  74961.   Mem t;

  74962.   assert( pFunc!=0 );

  74963.   assert( pFunc->xValue!=0 );

  74964.   assert( (pAccum->flags & MEM_Null)!=0 || pFunc==pAccum->u.pDef );

  74965.   assert( pAccum->db==0 || sqlite3_mutex_held(pAccum->db->mutex) );

  74966.   memset(&ctx, 0, sizeof(ctx));

  74967.   memset(&t, 0, sizeof(t));

  74968.   t.flags = MEM_Null;

  74969.   t.db = pAccum->db;

  74970.   sqlite3VdbeMemSetNull(pOut);

  74971.   ctx.pOut = pOut;

  74972.   ctx.pMem = pAccum;

  74973.   ctx.pFunc = pFunc;

  74974.   pFunc->xValue(&ctx);

  74975.   return ctx.isError;

  74976. }

  74977. #endif /* SQLITE_OMIT_WINDOWFUNC */

  74978. 

  74979. /*

  74980. ** If the memory cell contains a value that must be freed by

  74981. ** invoking the external callback in Mem.xDel, then this routine

  74982. ** will free that value.  It also sets Mem.flags to MEM_Null.

  74983. **

  74984. ** This is a helper routine for sqlite3VdbeMemSetNull() and

  74985. ** for sqlite3VdbeMemRelease().  Use those other routines as the

  74986. ** entry point for releasing Mem resources.

  74987. */

  74988. static SQLITE_NOINLINE void vdbeMemClearExternAndSetNull(Mem *p){

  74989.   assert( p->db==0 || sqlite3_mutex_held(p->db->mutex) );

  74990.   assert( VdbeMemDynamic(p) );

  74991.   if( p->flags&MEM_Agg ){

  74992.     sqlite3VdbeMemFinalize(p, p->u.pDef);

  74993.     assert( (p->flags & MEM_Agg)==0 );

  74994.     testcase( p->flags & MEM_Dyn );

  74995.   }

  74996.   if( p->flags&MEM_Dyn ){

  74997.     assert( p->xDel!=SQLITE_DYNAMIC && p->xDel!=0 );

  74998.     p->xDel((void *)p->z);

  74999.   }

  75000.   p->flags = MEM_Null;

  75001. }

  75002. 

  75003. /*

  75004. ** Release memory held by the Mem p, both external memory cleared

  75005. ** by p->xDel and memory in p->zMalloc.

  75006. **

  75007. ** This is a helper routine invoked by sqlite3VdbeMemRelease() in

  75008. ** the unusual case where there really is memory in p that needs

  75009. ** to be freed.

  75010. */

  75011. static SQLITE_NOINLINE void vdbeMemClear(Mem *p){

  75012.   if( VdbeMemDynamic(p) ){

  75013.     vdbeMemClearExternAndSetNull(p);

  75014.   }

  75015.   if( p->szMalloc ){

  75016.     sqlite3DbFreeNN(p->db, p->zMalloc);

  75017.     p->szMalloc = 0;

  75018.   }

  75019.   p->z = 0;

  75020. }

  75021. 

  75022. /*

  75023. ** Release any memory resources held by the Mem.  Both the memory that is

  75024. ** free by Mem.xDel and the Mem.zMalloc allocation are freed.

  75025. **

  75026. ** Use this routine prior to clean up prior to abandoning a Mem, or to

  75027. ** reset a Mem back to its minimum memory utilization.

  75028. **

  75029. ** Use sqlite3VdbeMemSetNull() to release just the Mem.xDel space

  75030. ** prior to inserting new content into the Mem.

  75031. */

  75032. SQLITE_PRIVATE void sqlite3VdbeMemRelease(Mem *p){

  75033.   assert( sqlite3VdbeCheckMemInvariants(p) );

  75034.   if( VdbeMemDynamic(p) || p->szMalloc ){

  75035.     vdbeMemClear(p);

  75036.   }

  75037. }

  75038. 

  75039. /*

  75040. ** Convert a 64-bit IEEE double into a 64-bit signed integer.

  75041. ** If the double is out of range of a 64-bit signed integer then

  75042. ** return the closest available 64-bit signed integer.

  75043. */

  75044. static SQLITE_NOINLINE i64 doubleToInt64(double r){

  75045. #ifdef SQLITE_OMIT_FLOATING_POINT

  75046.   /* When floating-point is omitted, double and int64 are the same thing */

  75047.   return r;

  75048. #else

  75049.   /*

  75050.   ** Many compilers we encounter do not define constants for the

  75051.   ** minimum and maximum 64-bit integers, or they define them

  75052.   ** inconsistently.  And many do not understand the "LL" notation.

  75053.   ** So we define our own static constants here using nothing

  75054.   ** larger than a 32-bit integer constant.

  75055.   */

  75056.   static const i64 maxInt = LARGEST_INT64;

  75057.   static const i64 minInt = SMALLEST_INT64;

  75058. 

  75059.   if( r<=(double)minInt ){

  75060.     return minInt;

  75061.   }else if( r>=(double)maxInt ){

  75062.     return maxInt;

  75063.   }else{

  75064.     return (i64)r;

  75065.   }

  75066. #endif

  75067. }

  75068. 

  75069. /*

  75070. ** Return some kind of integer value which is the best we can do

  75071. ** at representing the value that *pMem describes as an integer.

  75072. ** If pMem is an integer, then the value is exact.  If pMem is

  75073. ** a floating-point then the value returned is the integer part.

  75074. ** If pMem is a string or blob, then we make an attempt to convert

  75075. ** it into an integer and return that.  If pMem represents an

  75076. ** an SQL-NULL value, return 0.

  75077. **

  75078. ** If pMem represents a string value, its encoding might be changed.

  75079. */

  75080. static SQLITE_NOINLINE i64 memIntValue(Mem *pMem){

  75081.   i64 value = 0;

  75082.   sqlite3Atoi64(pMem->z, &value, pMem->n, pMem->enc);

  75083.   return value;

  75084. }

  75085. SQLITE_PRIVATE i64 sqlite3VdbeIntValue(Mem *pMem){

  75086.   int flags;

  75087.   assert( pMem->db==0 || sqlite3_mutex_held(pMem->db->mutex) );

  75088.   assert( EIGHT_BYTE_ALIGNMENT(pMem) );

  75089.   flags = pMem->flags;

  75090.   if( flags & (MEM_Int|MEM_IntReal) ){

  75091.     testcase( flags & MEM_IntReal );

  75092.     return pMem->u.i;

  75093.   }else if( flags & MEM_Real ){

  75094.     return doubleToInt64(pMem->u.r);

  75095.   }else if( flags & (MEM_Str|MEM_Blob) ){

  75096.     assert( pMem->z || pMem->n==0 );

  75097.     return memIntValue(pMem);

  75098.   }else{

  75099.     return 0;

  75100.   }

  75101. }

  75102. 

  75103. /*

  75104. ** Return the best representation of pMem that we can get into a

  75105. ** double.  If pMem is already a double or an integer, return its

  75106. ** value.  If it is a string or blob, try to convert it to a double.

  75107. ** If it is a NULL, return 0.0.

  75108. */

  75109. static SQLITE_NOINLINE double memRealValue(Mem *pMem){

  75110.   /* (double)0 In case of SQLITE_OMIT_FLOATING_POINT... */

  75111.   double val = (double)0;

  75112.   sqlite3AtoF(pMem->z, &val, pMem->n, pMem->enc);

  75113.   return val;

  75114. }

  75115. SQLITE_PRIVATE double sqlite3VdbeRealValue(Mem *pMem){

  75116.   assert( pMem->db==0 || sqlite3_mutex_held(pMem->db->mutex) );

  75117.   assert( EIGHT_BYTE_ALIGNMENT(pMem) );

  75118.   if( pMem->flags & MEM_Real ){

  75119.     return pMem->u.r;

  75120.   }else if( pMem->flags & (MEM_Int|MEM_IntReal) ){

  75121.     testcase( pMem->flags & MEM_IntReal );

  75122.     return (double)pMem->u.i;

  75123.   }else if( pMem->flags & (MEM_Str|MEM_Blob) ){

  75124.     return memRealValue(pMem);

  75125.   }else{

  75126.     /* (double)0 In case of SQLITE_OMIT_FLOATING_POINT... */

  75127.     return (double)0;

  75128.   }

  75129. }

  75130. 

  75131. /*

  75132. ** Return 1 if pMem represents true, and return 0 if pMem represents false.

  75133. ** Return the value ifNull if pMem is NULL.  

  75134. */

  75135. SQLITE_PRIVATE int sqlite3VdbeBooleanValue(Mem *pMem, int ifNull){

  75136.   testcase( pMem->flags & MEM_IntReal );

  75137.   if( pMem->flags & (MEM_Int|MEM_IntReal) ) return pMem->u.i!=0;

  75138.   if( pMem->flags & MEM_Null ) return ifNull;

  75139.   return sqlite3VdbeRealValue(pMem)!=0.0;

  75140. }

  75141. 

  75142. /*

  75143. ** The MEM structure is already a MEM_Real.  Try to also make it a

  75144. ** MEM_Int if we can.

  75145. */

  75146. SQLITE_PRIVATE void sqlite3VdbeIntegerAffinity(Mem *pMem){

  75147.   i64 ix;

  75148.   assert( pMem->flags & MEM_Real );

  75149.   assert( !sqlite3VdbeMemIsRowSet(pMem) );

  75150.   assert( pMem->db==0 || sqlite3_mutex_held(pMem->db->mutex) );

  75151.   assert( EIGHT_BYTE_ALIGNMENT(pMem) );

  75152. 

  75153.   ix = doubleToInt64(pMem->u.r);

  75154. 

  75155.   /* Only mark the value as an integer if

  75156.   **

  75157.   **    (1) the round-trip conversion real->int->real is a no-op, and

  75158.   **    (2) The integer is neither the largest nor the smallest

  75159.   **        possible integer (ticket #3922)

  75160.   **

  75161.   ** The second and third terms in the following conditional enforces

  75162.   ** the second condition under the assumption that addition overflow causes

  75163.   ** values to wrap around.

  75164.   */

  75165.   if( pMem->u.r==ix && ix>SMALLEST_INT64 && ix<LARGEST_INT64 ){

  75166.     pMem->u.i = ix;

  75167.     MemSetTypeFlag(pMem, MEM_Int);

  75168.   }

  75169. }

  75170. 

  75171. /*

  75172. ** Convert pMem to type integer.  Invalidate any prior representations.

  75173. */

  75174. SQLITE_PRIVATE int sqlite3VdbeMemIntegerify(Mem *pMem){

  75175.   assert( pMem->db==0 || sqlite3_mutex_held(pMem->db->mutex) );

  75176.   assert( !sqlite3VdbeMemIsRowSet(pMem) );

  75177.   assert( EIGHT_BYTE_ALIGNMENT(pMem) );

  75178. 

  75179.   pMem->u.i = sqlite3VdbeIntValue(pMem);

  75180.   MemSetTypeFlag(pMem, MEM_Int);

  75181.   return SQLITE_OK;

  75182. }

  75183. 

  75184. /*

  75185. ** Convert pMem so that it is of type MEM_Real.

  75186. ** Invalidate any prior representations.

  75187. */

  75188. SQLITE_PRIVATE int sqlite3VdbeMemRealify(Mem *pMem){

  75189.   assert( pMem->db==0 || sqlite3_mutex_held(pMem->db->mutex) );

  75190.   assert( EIGHT_BYTE_ALIGNMENT(pMem) );

  75191. 

  75192.   pMem->u.r = sqlite3VdbeRealValue(pMem);

  75193.   MemSetTypeFlag(pMem, MEM_Real);

  75194.   return SQLITE_OK;

  75195. }

  75196. 

  75197. /* Compare a floating point value to an integer.  Return true if the two

  75198. ** values are the same within the precision of the floating point value.

  75199. **

  75200. ** This function assumes that i was obtained by assignment from r1.

  75201. **

  75202. ** For some versions of GCC on 32-bit machines, if you do the more obvious

  75203. ** comparison of "r1==(double)i" you sometimes get an answer of false even

  75204. ** though the r1 and (double)i values are bit-for-bit the same.

  75205. */

  75206. SQLITE_PRIVATE int sqlite3RealSameAsInt(double r1, sqlite3_int64 i){

  75207.   double r2 = (double)i;

  75208.   return r1==0.0

  75209.       || (memcmp(&r1, &r2, sizeof(r1))==0

  75210.           && i >= -2251799813685248LL && i < 2251799813685248LL);

  75211. }

  75212. 

  75213. /*

  75214. ** Convert pMem so that it has type MEM_Real or MEM_Int.

  75215. ** Invalidate any prior representations.

  75216. **

  75217. ** Every effort is made to force the conversion, even if the input

  75218. ** is a string that does not look completely like a number.  Convert

  75219. ** as much of the string as we can and ignore the rest.

  75220. */

  75221. SQLITE_PRIVATE int sqlite3VdbeMemNumerify(Mem *pMem){

  75222.   testcase( pMem->flags & MEM_Int );

  75223.   testcase( pMem->flags & MEM_Real );

  75224.   testcase( pMem->flags & MEM_IntReal );

  75225.   testcase( pMem->flags & MEM_Null );

  75226.   if( (pMem->flags & (MEM_Int|MEM_Real|MEM_IntReal|MEM_Null))==0 ){

  75227.     int rc;

  75228.     sqlite3_int64 ix;

  75229.     assert( (pMem->flags & (MEM_Blob|MEM_Str))!=0 );

  75230.     assert( pMem->db==0 || sqlite3_mutex_held(pMem->db->mutex) );

  75231.     rc = sqlite3AtoF(pMem->z, &pMem->u.r, pMem->n, pMem->enc);

  75232.     if( ((rc==0 || rc==1) && sqlite3Atoi64(pMem->z, &ix, pMem->n, pMem->enc)<=1)

  75233.      || sqlite3RealSameAsInt(pMem->u.r, (ix = (i64)pMem->u.r))

  75234.     ){

  75235.       pMem->u.i = ix;

  75236.       MemSetTypeFlag(pMem, MEM_Int);

  75237.     }else{

  75238.       MemSetTypeFlag(pMem, MEM_Real);

  75239.     }

  75240.   }

  75241.   assert( (pMem->flags & (MEM_Int|MEM_Real|MEM_IntReal|MEM_Null))!=0 );

  75242.   pMem->flags &= ~(MEM_Str|MEM_Blob|MEM_Zero);

  75243.   return SQLITE_OK;

  75244. }

  75245. 

  75246. /*

  75247. ** Cast the datatype of the value in pMem according to the affinity

  75248. ** "aff".  Casting is different from applying affinity in that a cast

  75249. ** is forced.  In other words, the value is converted into the desired

  75250. ** affinity even if that results in loss of data.  This routine is

  75251. ** used (for example) to implement the SQL "cast()" operator.

  75252. */

  75253. SQLITE_PRIVATE void sqlite3VdbeMemCast(Mem *pMem, u8 aff, u8 encoding){

  75254.   if( pMem->flags & MEM_Null ) return;

  75255.   switch( aff ){

  75256.     case SQLITE_AFF_BLOB: {   /* Really a cast to BLOB */

  75257.       if( (pMem->flags & MEM_Blob)==0 ){

  75258.         sqlite3ValueApplyAffinity(pMem, SQLITE_AFF_TEXT, encoding);

  75259.         assert( pMem->flags & MEM_Str || pMem->db->mallocFailed );

  75260.         if( pMem->flags & MEM_Str ) MemSetTypeFlag(pMem, MEM_Blob);

  75261.       }else{

  75262.         pMem->flags &= ~(MEM_TypeMask&~MEM_Blob);

  75263.       }

  75264.       break;

  75265.     }

  75266.     case SQLITE_AFF_NUMERIC: {

  75267.       sqlite3VdbeMemNumerify(pMem);

  75268.       break;

  75269.     }

  75270.     case SQLITE_AFF_INTEGER: {

  75271.       sqlite3VdbeMemIntegerify(pMem);

  75272.       break;

  75273.     }

  75274.     case SQLITE_AFF_REAL: {

  75275.       sqlite3VdbeMemRealify(pMem);

  75276.       break;

  75277.     }

  75278.     default: {

  75279.       assert( aff==SQLITE_AFF_TEXT );

  75280.       assert( MEM_Str==(MEM_Blob>>3) );

  75281.       pMem->flags |= (pMem->flags&MEM_Blob)>>3;

  75282.       sqlite3ValueApplyAffinity(pMem, SQLITE_AFF_TEXT, encoding);

  75283.       assert( pMem->flags & MEM_Str || pMem->db->mallocFailed );

  75284.       pMem->flags &= ~(MEM_Int|MEM_Real|MEM_IntReal|MEM_Blob|MEM_Zero);

  75285.       break;

  75286.     }

  75287.   }

  75288. }

  75289. 

  75290. /*

  75291. ** Initialize bulk memory to be a consistent Mem object.

  75292. **

  75293. ** The minimum amount of initialization feasible is performed.

  75294. */

  75295. SQLITE_PRIVATE void sqlite3VdbeMemInit(Mem *pMem, sqlite3 *db, u16 flags){

  75296.   assert( (flags & ~MEM_TypeMask)==0 );

  75297.   pMem->flags = flags;

  75298.   pMem->db = db;

  75299.   pMem->szMalloc = 0;

  75300. }

  75301. 

  75302. 

  75303. /*

  75304. ** Delete any previous value and set the value stored in *pMem to NULL.

  75305. **

  75306. ** This routine calls the Mem.xDel destructor to dispose of values that

  75307. ** require the destructor.  But it preserves the Mem.zMalloc memory allocation.

  75308. ** To free all resources, use sqlite3VdbeMemRelease(), which both calls this

  75309. ** routine to invoke the destructor and deallocates Mem.zMalloc.

  75310. **

  75311. ** Use this routine to reset the Mem prior to insert a new value.

  75312. **

  75313. ** Use sqlite3VdbeMemRelease() to complete erase the Mem prior to abandoning it.

  75314. */

  75315. SQLITE_PRIVATE void sqlite3VdbeMemSetNull(Mem *pMem){

  75316.   if( VdbeMemDynamic(pMem) ){

  75317.     vdbeMemClearExternAndSetNull(pMem);

  75318.   }else{

  75319.     pMem->flags = MEM_Null;

  75320.   }

  75321. }

  75322. SQLITE_PRIVATE void sqlite3ValueSetNull(sqlite3_value *p){

  75323.   sqlite3VdbeMemSetNull((Mem*)p); 

  75324. }

  75325. 

  75326. /*

  75327. ** Delete any previous value and set the value to be a BLOB of length

  75328. ** n containing all zeros.

  75329. */

  75330. SQLITE_PRIVATE void sqlite3VdbeMemSetZeroBlob(Mem *pMem, int n){

  75331.   sqlite3VdbeMemRelease(pMem);

  75332.   pMem->flags = MEM_Blob|MEM_Zero;

  75333.   pMem->n = 0;

  75334.   if( n<0 ) n = 0;

  75335.   pMem->u.nZero = n;

  75336.   pMem->enc = SQLITE_UTF8;

  75337.   pMem->z = 0;

  75338. }

  75339. 

  75340. /*

  75341. ** The pMem is known to contain content that needs to be destroyed prior

  75342. ** to a value change.  So invoke the destructor, then set the value to

  75343. ** a 64-bit integer.

  75344. */

  75345. static SQLITE_NOINLINE void vdbeReleaseAndSetInt64(Mem *pMem, i64 val){

  75346.   sqlite3VdbeMemSetNull(pMem);

  75347.   pMem->u.i = val;

  75348.   pMem->flags = MEM_Int;

  75349. }

  75350. 

  75351. /*

  75352. ** Delete any previous value and set the value stored in *pMem to val,

  75353. ** manifest type INTEGER.

  75354. */

  75355. SQLITE_PRIVATE void sqlite3VdbeMemSetInt64(Mem *pMem, i64 val){

  75356.   if( VdbeMemDynamic(pMem) ){

  75357.     vdbeReleaseAndSetInt64(pMem, val);

  75358.   }else{

  75359.     pMem->u.i = val;

  75360.     pMem->flags = MEM_Int;

  75361.   }

  75362. }

  75363. 

  75364. /* A no-op destructor */

  75365. SQLITE_PRIVATE void sqlite3NoopDestructor(void *p){ UNUSED_PARAMETER(p); }

  75366. 

  75367. /*

  75368. ** Set the value stored in *pMem should already be a NULL.

  75369. ** Also store a pointer to go with it.

  75370. */

  75371. SQLITE_PRIVATE void sqlite3VdbeMemSetPointer(

  75372.   Mem *pMem,

  75373.   void *pPtr,

  75374.   const char *zPType,

  75375.   void (*xDestructor)(void*)

  75376. ){

  75377.   assert( pMem->flags==MEM_Null );

  75378.   pMem->u.zPType = zPType ? zPType : "";

  75379.   pMem->z = pPtr;

  75380.   pMem->flags = MEM_Null|MEM_Dyn|MEM_Subtype|MEM_Term;

  75381.   pMem->eSubtype = 'p';

  75382.   pMem->xDel = xDestructor ? xDestructor : sqlite3NoopDestructor;

  75383. }

  75384. 

  75385. #ifndef SQLITE_OMIT_FLOATING_POINT

  75386. /*

  75387. ** Delete any previous value and set the value stored in *pMem to val,

  75388. ** manifest type REAL.

  75389. */

  75390. SQLITE_PRIVATE void sqlite3VdbeMemSetDouble(Mem *pMem, double val){

  75391.   sqlite3VdbeMemSetNull(pMem);

  75392.   if( !sqlite3IsNaN(val) ){

  75393.     pMem->u.r = val;

  75394.     pMem->flags = MEM_Real;

  75395.   }

  75396. }

  75397. #endif

  75398. 

  75399. #ifdef SQLITE_DEBUG

  75400. /*

  75401. ** Return true if the Mem holds a RowSet object.  This routine is intended

  75402. ** for use inside of assert() statements.

  75403. */

  75404. SQLITE_PRIVATE int sqlite3VdbeMemIsRowSet(const Mem *pMem){

  75405.   return (pMem->flags&(MEM_Blob|MEM_Dyn))==(MEM_Blob|MEM_Dyn)

  75406.          && pMem->xDel==sqlite3RowSetDelete;

  75407. }

  75408. #endif

  75409. 

  75410. /*

  75411. ** Delete any previous value and set the value of pMem to be an

  75412. ** empty boolean index.

  75413. **

  75414. ** Return SQLITE_OK on success and SQLITE_NOMEM if a memory allocation

  75415. ** error occurs.

  75416. */

  75417. SQLITE_PRIVATE int sqlite3VdbeMemSetRowSet(Mem *pMem){

  75418.   sqlite3 *db = pMem->db;

  75419.   RowSet *p;

  75420.   assert( db!=0 );

  75421.   assert( !sqlite3VdbeMemIsRowSet(pMem) );

  75422.   sqlite3VdbeMemRelease(pMem);

  75423.   p = sqlite3RowSetInit(db);

  75424.   if( p==0 ) return SQLITE_NOMEM;

  75425.   pMem->z = (char*)p;

  75426.   pMem->flags = MEM_Blob|MEM_Dyn;

  75427.   pMem->xDel = sqlite3RowSetDelete;

  75428.   return SQLITE_OK;

  75429. }

  75430. 

  75431. /*

  75432. ** Return true if the Mem object contains a TEXT or BLOB that is

  75433. ** too large - whose size exceeds SQLITE_MAX_LENGTH.

  75434. */

  75435. SQLITE_PRIVATE int sqlite3VdbeMemTooBig(Mem *p){

  75436.   assert( p->db!=0 );

  75437.   if( p->flags & (MEM_Str|MEM_Blob) ){

  75438.     int n = p->n;

  75439.     if( p->flags & MEM_Zero ){

  75440.       n += p->u.nZero;

  75441.     }

  75442.     return n>p->db->aLimit[SQLITE_LIMIT_LENGTH];

  75443.   }

  75444.   return 0; 

  75445. }

  75446. 

  75447. #ifdef SQLITE_DEBUG

  75448. /*

  75449. ** This routine prepares a memory cell for modification by breaking

  75450. ** its link to a shallow copy and by marking any current shallow

  75451. ** copies of this cell as invalid.

  75452. **

  75453. ** This is used for testing and debugging only - to make sure shallow

  75454. ** copies are not misused.

  75455. */

  75456. SQLITE_PRIVATE void sqlite3VdbeMemAboutToChange(Vdbe *pVdbe, Mem *pMem){

  75457.   int i;

  75458.   Mem *pX;

  75459.   for(i=0, pX=pVdbe->aMem; i<pVdbe->nMem; i++, pX++){

  75460.     if( pX->pScopyFrom==pMem ){

  75461.       /* If pX is marked as a shallow copy of pMem, then verify that

  75462.       ** no significant changes have been made to pX since the OP_SCopy.

  75463.       ** A significant change would indicated a missed call to this

  75464.       ** function for pX.  Minor changes, such as adding or removing a

  75465.       ** dual type, are allowed, as long as the underlying value is the

  75466.       ** same. */

  75467.       u16 mFlags = pMem->flags & pX->flags & pX->mScopyFlags;

  75468.       assert( (mFlags&(MEM_Int|MEM_IntReal))==0 || pMem->u.i==pX->u.i );

  75469.       assert( (mFlags&MEM_Real)==0 || pMem->u.r==pX->u.r );

  75470.       assert( (mFlags&MEM_Str)==0  || (pMem->n==pX->n && pMem->z==pX->z) );

  75471.       assert( (mFlags&MEM_Blob)==0  || sqlite3BlobCompare(pMem,pX)==0 );

  75472.       

  75473.       /* pMem is the register that is changing.  But also mark pX as

  75474.       ** undefined so that we can quickly detect the shallow-copy error */

  75475.       pX->flags = MEM_Undefined;

  75476.       pX->pScopyFrom = 0;

  75477.     }

  75478.   }

  75479.   pMem->pScopyFrom = 0;

  75480. }

  75481. #endif /* SQLITE_DEBUG */

  75482. 

  75483. 

  75484. /*

  75485. ** Make an shallow copy of pFrom into pTo.  Prior contents of

  75486. ** pTo are freed.  The pFrom->z field is not duplicated.  If

  75487. ** pFrom->z is used, then pTo->z points to the same thing as pFrom->z

  75488. ** and flags gets srcType (either MEM_Ephem or MEM_Static).

  75489. */

  75490. static SQLITE_NOINLINE void vdbeClrCopy(Mem *pTo, const Mem *pFrom, int eType){

  75491.   vdbeMemClearExternAndSetNull(pTo);

  75492.   assert( !VdbeMemDynamic(pTo) );

  75493.   sqlite3VdbeMemShallowCopy(pTo, pFrom, eType);

  75494. }

  75495. SQLITE_PRIVATE void sqlite3VdbeMemShallowCopy(Mem *pTo, const Mem *pFrom, int srcType){

  75496.   assert( !sqlite3VdbeMemIsRowSet(pFrom) );

  75497.   assert( pTo->db==pFrom->db );

  75498.   if( VdbeMemDynamic(pTo) ){ vdbeClrCopy(pTo,pFrom,srcType); return; }

  75499.   memcpy(pTo, pFrom, MEMCELLSIZE);

  75500.   if( (pFrom->flags&MEM_Static)==0 ){

  75501.     pTo->flags &= ~(MEM_Dyn|MEM_Static|MEM_Ephem);

  75502.     assert( srcType==MEM_Ephem || srcType==MEM_Static );

  75503.     pTo->flags |= srcType;

  75504.   }

  75505. }

  75506. 

  75507. /*

  75508. ** Make a full copy of pFrom into pTo.  Prior contents of pTo are

  75509. ** freed before the copy is made.

  75510. */

  75511. SQLITE_PRIVATE int sqlite3VdbeMemCopy(Mem *pTo, const Mem *pFrom){

  75512.   int rc = SQLITE_OK;

  75513. 

  75514.   assert( !sqlite3VdbeMemIsRowSet(pFrom) );

  75515.   if( VdbeMemDynamic(pTo) ) vdbeMemClearExternAndSetNull(pTo);

  75516.   memcpy(pTo, pFrom, MEMCELLSIZE);

  75517.   pTo->flags &= ~MEM_Dyn;

  75518.   if( pTo->flags&(MEM_Str|MEM_Blob) ){

  75519.     if( 0==(pFrom->flags&MEM_Static) ){

  75520.       pTo->flags |= MEM_Ephem;

  75521.       rc = sqlite3VdbeMemMakeWriteable(pTo);

  75522.     }

  75523.   }

  75524. 

  75525.   return rc;

  75526. }

  75527. 

  75528. /*

  75529. ** Transfer the contents of pFrom to pTo. Any existing value in pTo is

  75530. ** freed. If pFrom contains ephemeral data, a copy is made.

  75531. **

  75532. ** pFrom contains an SQL NULL when this routine returns.

  75533. */

  75534. SQLITE_PRIVATE void sqlite3VdbeMemMove(Mem *pTo, Mem *pFrom){

  75535.   assert( pFrom->db==0 || sqlite3_mutex_held(pFrom->db->mutex) );

  75536.   assert( pTo->db==0 || sqlite3_mutex_held(pTo->db->mutex) );

  75537.   assert( pFrom->db==0 || pTo->db==0 || pFrom->db==pTo->db );

  75538. 

  75539.   sqlite3VdbeMemRelease(pTo);

  75540.   memcpy(pTo, pFrom, sizeof(Mem));

  75541.   pFrom->flags = MEM_Null;

  75542.   pFrom->szMalloc = 0;

  75543. }

  75544. 

  75545. /*

  75546. ** Change the value of a Mem to be a string or a BLOB.

  75547. **

  75548. ** The memory management strategy depends on the value of the xDel

  75549. ** parameter. If the value passed is SQLITE_TRANSIENT, then the 

  75550. ** string is copied into a (possibly existing) buffer managed by the 

  75551. ** Mem structure. Otherwise, any existing buffer is freed and the

  75552. ** pointer copied.

  75553. **

  75554. ** If the string is too large (if it exceeds the SQLITE_LIMIT_LENGTH

  75555. ** size limit) then no memory allocation occurs.  If the string can be

  75556. ** stored without allocating memory, then it is.  If a memory allocation

  75557. ** is required to store the string, then value of pMem is unchanged.  In

  75558. ** either case, SQLITE_TOOBIG is returned.

  75559. */

  75560. SQLITE_PRIVATE int sqlite3VdbeMemSetStr(

  75561.   Mem *pMem,          /* Memory cell to set to string value */

  75562.   const char *z,      /* String pointer */

  75563.   int n,              /* Bytes in string, or negative */

  75564.   u8 enc,             /* Encoding of z.  0 for BLOBs */

  75565.   void (*xDel)(void*) /* Destructor function */

  75566. ){

  75567.   int nByte = n;      /* New value for pMem->n */

  75568.   int iLimit;         /* Maximum allowed string or blob size */

  75569.   u16 flags = 0;      /* New value for pMem->flags */

  75570. 

  75571.   assert( pMem->db==0 || sqlite3_mutex_held(pMem->db->mutex) );

  75572.   assert( !sqlite3VdbeMemIsRowSet(pMem) );

  75573. 

  75574.   /* If z is a NULL pointer, set pMem to contain an SQL NULL. */

  75575.   if( !z ){

  75576.     sqlite3VdbeMemSetNull(pMem);

  75577.     return SQLITE_OK;

  75578.   }

  75579. 

  75580.   if( pMem->db ){

  75581.     iLimit = pMem->db->aLimit[SQLITE_LIMIT_LENGTH];

  75582.   }else{

  75583.     iLimit = SQLITE_MAX_LENGTH;

  75584.   }

  75585.   flags = (enc==0?MEM_Blob:MEM_Str);

  75586.   if( nByte<0 ){

  75587.     assert( enc!=0 );

  75588.     if( enc==SQLITE_UTF8 ){

  75589.       nByte = 0x7fffffff & (int)strlen(z);

  75590.     }else{

  75591.       for(nByte=0; nByte<=iLimit && (z[nByte] | z[nByte+1]); nByte+=2){}

  75592.     }

  75593.     flags |= MEM_Term;

  75594.   }

  75595. 

  75596.   /* The following block sets the new values of Mem.z and Mem.xDel. It

  75597.   ** also sets a flag in local variable "flags" to indicate the memory

  75598.   ** management (one of MEM_Dyn or MEM_Static).

  75599.   */

  75600.   if( xDel==SQLITE_TRANSIENT ){

  75601.     u32 nAlloc = nByte;

  75602.     if( flags&MEM_Term ){

  75603.       nAlloc += (enc==SQLITE_UTF8?1:2);

  75604.     }

  75605.     if( nByte>iLimit ){

  75606.       return sqlite3ErrorToParser(pMem->db, SQLITE_TOOBIG);

  75607.     }

  75608.     testcase( nAlloc==0 );

  75609.     testcase( nAlloc==31 );

  75610.     testcase( nAlloc==32 );

  75611.     if( sqlite3VdbeMemClearAndResize(pMem, (int)MAX(nAlloc,32)) ){

  75612.       return SQLITE_NOMEM_BKPT;

  75613.     }

  75614.     memcpy(pMem->z, z, nAlloc);

  75615.   }else{

  75616.     sqlite3VdbeMemRelease(pMem);

  75617.     pMem->z = (char *)z;

  75618.     if( xDel==SQLITE_DYNAMIC ){

  75619.       pMem->zMalloc = pMem->z;

  75620.       pMem->szMalloc = sqlite3DbMallocSize(pMem->db, pMem->zMalloc);

  75621.     }else{

  75622.       pMem->xDel = xDel;

  75623.       flags |= ((xDel==SQLITE_STATIC)?MEM_Static:MEM_Dyn);

  75624.     }

  75625.   }

  75626. 

  75627.   pMem->n = nByte;

  75628.   pMem->flags = flags;

  75629.   pMem->enc = (enc==0 ? SQLITE_UTF8 : enc);

  75630. 

  75631. #ifndef SQLITE_OMIT_UTF16

  75632.   if( pMem->enc!=SQLITE_UTF8 && sqlite3VdbeMemHandleBom(pMem) ){

  75633.     return SQLITE_NOMEM_BKPT;

  75634.   }

  75635. #endif

  75636. 

  75637.   if( nByte>iLimit ){

  75638.     return SQLITE_TOOBIG;

  75639.   }

  75640. 

  75641.   return SQLITE_OK;

  75642. }

  75643. 

  75644. /*

  75645. ** Move data out of a btree key or data field and into a Mem structure.

  75646. ** The data is payload from the entry that pCur is currently pointing

  75647. ** to.  offset and amt determine what portion of the data or key to retrieve.

  75648. ** The result is written into the pMem element.

  75649. **

  75650. ** The pMem object must have been initialized.  This routine will use

  75651. ** pMem->zMalloc to hold the content from the btree, if possible.  New

  75652. ** pMem->zMalloc space will be allocated if necessary.  The calling routine

  75653. ** is responsible for making sure that the pMem object is eventually

  75654. ** destroyed.

  75655. **

  75656. ** If this routine fails for any reason (malloc returns NULL or unable

  75657. ** to read from the disk) then the pMem is left in an inconsistent state.

  75658. */

  75659. static SQLITE_NOINLINE int vdbeMemFromBtreeResize(

  75660.   BtCursor *pCur,   /* Cursor pointing at record to retrieve. */

  75661.   u32 offset,       /* Offset from the start of data to return bytes from. */

  75662.   u32 amt,          /* Number of bytes to return. */

  75663.   Mem *pMem         /* OUT: Return data in this Mem structure. */

  75664. ){

  75665.   int rc;

  75666.   pMem->flags = MEM_Null;

  75667.   if( sqlite3BtreeMaxRecordSize(pCur)<offset+amt ){

  75668.     return SQLITE_CORRUPT_BKPT;

  75669.   }

  75670.   if( SQLITE_OK==(rc = sqlite3VdbeMemClearAndResize(pMem, amt+1)) ){

  75671.     rc = sqlite3BtreePayload(pCur, offset, amt, pMem->z);

  75672.     if( rc==SQLITE_OK ){

  75673.       pMem->z[amt] = 0;   /* Overrun area used when reading malformed records */

  75674.       pMem->flags = MEM_Blob;

  75675.       pMem->n = (int)amt;

  75676.     }else{

  75677.       sqlite3VdbeMemRelease(pMem);

  75678.     }

  75679.   }

  75680.   return rc;

  75681. }

  75682. SQLITE_PRIVATE int sqlite3VdbeMemFromBtree(

  75683.   BtCursor *pCur,   /* Cursor pointing at record to retrieve. */

  75684.   u32 offset,       /* Offset from the start of data to return bytes from. */

  75685.   u32 amt,          /* Number of bytes to return. */

  75686.   Mem *pMem         /* OUT: Return data in this Mem structure. */

  75687. ){

  75688.   char *zData;        /* Data from the btree layer */

  75689.   u32 available = 0;  /* Number of bytes available on the local btree page */

  75690.   int rc = SQLITE_OK; /* Return code */

  75691. 

  75692.   assert( sqlite3BtreeCursorIsValid(pCur) );

  75693.   assert( !VdbeMemDynamic(pMem) );

  75694. 

  75695.   /* Note: the calls to BtreeKeyFetch() and DataFetch() below assert() 

  75696.   ** that both the BtShared and database handle mutexes are held. */

  75697.   assert( !sqlite3VdbeMemIsRowSet(pMem) );

  75698.   zData = (char *)sqlite3BtreePayloadFetch(pCur, &available);

  75699.   assert( zData!=0 );

  75700. 

  75701.   if( offset+amt<=available ){

  75702.     pMem->z = &zData[offset];

  75703.     pMem->flags = MEM_Blob|MEM_Ephem;

  75704.     pMem->n = (int)amt;

  75705.   }else{

  75706.     rc = vdbeMemFromBtreeResize(pCur, offset, amt, pMem);

  75707.   }

  75708. 

  75709.   return rc;

  75710. }

  75711. 

  75712. /*

  75713. ** The pVal argument is known to be a value other than NULL.

  75714. ** Convert it into a string with encoding enc and return a pointer

  75715. ** to a zero-terminated version of that string.

  75716. */

  75717. static SQLITE_NOINLINE const void *valueToText(sqlite3_value* pVal, u8 enc){

  75718.   assert( pVal!=0 );

  75719.   assert( pVal->db==0 || sqlite3_mutex_held(pVal->db->mutex) );

  75720.   assert( (enc&3)==(enc&~SQLITE_UTF16_ALIGNED) );

  75721.   assert( !sqlite3VdbeMemIsRowSet(pVal) );

  75722.   assert( (pVal->flags & (MEM_Null))==0 );

  75723.   if( pVal->flags & (MEM_Blob|MEM_Str) ){

  75724.     if( ExpandBlob(pVal) ) return 0;

  75725.     pVal->flags |= MEM_Str;

  75726.     if( pVal->enc != (enc & ~SQLITE_UTF16_ALIGNED) ){

  75727.       sqlite3VdbeChangeEncoding(pVal, enc & ~SQLITE_UTF16_ALIGNED);

  75728.     }

  75729.     if( (enc & SQLITE_UTF16_ALIGNED)!=0 && 1==(1&SQLITE_PTR_TO_INT(pVal->z)) ){

  75730.       assert( (pVal->flags & (MEM_Ephem|MEM_Static))!=0 );

  75731.       if( sqlite3VdbeMemMakeWriteable(pVal)!=SQLITE_OK ){

  75732.         return 0;

  75733.       }

  75734.     }

  75735.     sqlite3VdbeMemNulTerminate(pVal); /* IMP: R-31275-44060 */

  75736.   }else{

  75737.     sqlite3VdbeMemStringify(pVal, enc, 0);

  75738.     assert( 0==(1&SQLITE_PTR_TO_INT(pVal->z)) );

  75739.   }

  75740.   assert(pVal->enc==(enc & ~SQLITE_UTF16_ALIGNED) || pVal->db==0

  75741.               || pVal->db->mallocFailed );

  75742.   if( pVal->enc==(enc & ~SQLITE_UTF16_ALIGNED) ){

  75743.     assert( sqlite3VdbeMemValidStrRep(pVal) );

  75744.     return pVal->z;

  75745.   }else{

  75746.     return 0;

  75747.   }

  75748. }

  75749. 

  75750. /* This function is only available internally, it is not part of the

  75751. ** external API. It works in a similar way to sqlite3_value_text(),

  75752. ** except the data returned is in the encoding specified by the second

  75753. ** parameter, which must be one of SQLITE_UTF16BE, SQLITE_UTF16LE or

  75754. ** SQLITE_UTF8.

  75755. **

  75756. ** (2006-02-16:)  The enc value can be or-ed with SQLITE_UTF16_ALIGNED.

  75757. ** If that is the case, then the result must be aligned on an even byte

  75758. ** boundary.

  75759. */

  75760. SQLITE_PRIVATE const void *sqlite3ValueText(sqlite3_value* pVal, u8 enc){

  75761.   if( !pVal ) return 0;

  75762.   assert( pVal->db==0 || sqlite3_mutex_held(pVal->db->mutex) );

  75763.   assert( (enc&3)==(enc&~SQLITE_UTF16_ALIGNED) );

  75764.   assert( !sqlite3VdbeMemIsRowSet(pVal) );

  75765.   if( (pVal->flags&(MEM_Str|MEM_Term))==(MEM_Str|MEM_Term) && pVal->enc==enc ){

  75766.     assert( sqlite3VdbeMemValidStrRep(pVal) );

  75767.     return pVal->z;

  75768.   }

  75769.   if( pVal->flags&MEM_Null ){

  75770.     return 0;

  75771.   }

  75772.   return valueToText(pVal, enc);

  75773. }

  75774. 

  75775. /*

  75776. ** Create a new sqlite3_value object.

  75777. */

  75778. SQLITE_PRIVATE sqlite3_value *sqlite3ValueNew(sqlite3 *db){

  75779.   Mem *p = sqlite3DbMallocZero(db, sizeof(*p));

  75780.   if( p ){

  75781.     p->flags = MEM_Null;

  75782.     p->db = db;

  75783.   }

  75784.   return p;

  75785. }

  75786. 

  75787. /*

  75788. ** Context object passed by sqlite3Stat4ProbeSetValue() through to 

  75789. ** valueNew(). See comments above valueNew() for details.

  75790. */

  75791. struct ValueNewStat4Ctx {

  75792.   Parse *pParse;

  75793.   Index *pIdx;

  75794.   UnpackedRecord **ppRec;

  75795.   int iVal;

  75796. };

  75797. 

  75798. /*

  75799. ** Allocate and return a pointer to a new sqlite3_value object. If

  75800. ** the second argument to this function is NULL, the object is allocated

  75801. ** by calling sqlite3ValueNew().

  75802. **

  75803. ** Otherwise, if the second argument is non-zero, then this function is 

  75804. ** being called indirectly by sqlite3Stat4ProbeSetValue(). If it has not

  75805. ** already been allocated, allocate the UnpackedRecord structure that 

  75806. ** that function will return to its caller here. Then return a pointer to

  75807. ** an sqlite3_value within the UnpackedRecord.a[] array.

  75808. */

  75809. static sqlite3_value *valueNew(sqlite3 *db, struct ValueNewStat4Ctx *p){

  75810. #ifdef SQLITE_ENABLE_STAT3_OR_STAT4

  75811.   if( p ){

  75812.     UnpackedRecord *pRec = p->ppRec[0];

  75813. 

  75814.     if( pRec==0 ){

  75815.       Index *pIdx = p->pIdx;      /* Index being probed */

  75816.       int nByte;                  /* Bytes of space to allocate */

  75817.       int i;                      /* Counter variable */

  75818.       int nCol = pIdx->nColumn;   /* Number of index columns including rowid */

  75819.   

  75820.       nByte = sizeof(Mem) * nCol + ROUND8(sizeof(UnpackedRecord));

  75821.       pRec = (UnpackedRecord*)sqlite3DbMallocZero(db, nByte);

  75822.       if( pRec ){

  75823.         pRec->pKeyInfo = sqlite3KeyInfoOfIndex(p->pParse, pIdx);

  75824.         if( pRec->pKeyInfo ){

  75825.           assert( pRec->pKeyInfo->nAllField==nCol );

  75826.           assert( pRec->pKeyInfo->enc==ENC(db) );

  75827.           pRec->aMem = (Mem *)((u8*)pRec + ROUND8(sizeof(UnpackedRecord)));

  75828.           for(i=0; i<nCol; i++){

  75829.             pRec->aMem[i].flags = MEM_Null;

  75830.             pRec->aMem[i].db = db;

  75831.           }

  75832.         }else{

  75833.           sqlite3DbFreeNN(db, pRec);

  75834.           pRec = 0;

  75835.         }

  75836.       }

  75837.       if( pRec==0 ) return 0;

  75838.       p->ppRec[0] = pRec;

  75839.     }

  75840.   

  75841.     pRec->nField = p->iVal+1;

  75842.     return &pRec->aMem[p->iVal];

  75843.   }

  75844. #else

  75845.   UNUSED_PARAMETER(p);

  75846. #endif /* defined(SQLITE_ENABLE_STAT3_OR_STAT4) */

  75847.   return sqlite3ValueNew(db);

  75848. }

  75849. 

  75850. /*

  75851. ** The expression object indicated by the second argument is guaranteed

  75852. ** to be a scalar SQL function. If

  75853. **

  75854. **   * all function arguments are SQL literals,

  75855. **   * one of the SQLITE_FUNC_CONSTANT or _SLOCHNG function flags is set, and

  75856. **   * the SQLITE_FUNC_NEEDCOLL function flag is not set,

  75857. **

  75858. ** then this routine attempts to invoke the SQL function. Assuming no

  75859. ** error occurs, output parameter (*ppVal) is set to point to a value 

  75860. ** object containing the result before returning SQLITE_OK.

  75861. **

  75862. ** Affinity aff is applied to the result of the function before returning.

  75863. ** If the result is a text value, the sqlite3_value object uses encoding 

  75864. ** enc.

  75865. **

  75866. ** If the conditions above are not met, this function returns SQLITE_OK

  75867. ** and sets (*ppVal) to NULL. Or, if an error occurs, (*ppVal) is set to

  75868. ** NULL and an SQLite error code returned.

  75869. */

  75870. #ifdef SQLITE_ENABLE_STAT3_OR_STAT4

  75871. static int valueFromFunction(

  75872.   sqlite3 *db,                    /* The database connection */

  75873.   Expr *p,                        /* The expression to evaluate */

  75874.   u8 enc,                         /* Encoding to use */

  75875.   u8 aff,                         /* Affinity to use */

  75876.   sqlite3_value **ppVal,          /* Write the new value here */

  75877.   struct ValueNewStat4Ctx *pCtx   /* Second argument for valueNew() */

  75878. ){

  75879.   sqlite3_context ctx;            /* Context object for function invocation */

  75880.   sqlite3_value **apVal = 0;      /* Function arguments */

  75881.   int nVal = 0;                   /* Size of apVal[] array */

  75882.   FuncDef *pFunc = 0;             /* Function definition */

  75883.   sqlite3_value *pVal = 0;        /* New value */

  75884.   int rc = SQLITE_OK;             /* Return code */

  75885.   ExprList *pList = 0;            /* Function arguments */

  75886.   int i;                          /* Iterator variable */

  75887. 

  75888.   assert( pCtx!=0 );

  75889.   assert( (p->flags & EP_TokenOnly)==0 );

  75890.   pList = p->x.pList;

  75891.   if( pList ) nVal = pList->nExpr;

  75892.   pFunc = sqlite3FindFunction(db, p->u.zToken, nVal, enc, 0);

  75893.   assert( pFunc );

  75894.   if( (pFunc->funcFlags & (SQLITE_FUNC_CONSTANT|SQLITE_FUNC_SLOCHNG))==0 

  75895.    || (pFunc->funcFlags & SQLITE_FUNC_NEEDCOLL)

  75896.   ){

  75897.     return SQLITE_OK;

  75898.   }

  75899. 

  75900.   if( pList ){

  75901.     apVal = (sqlite3_value**)sqlite3DbMallocZero(db, sizeof(apVal[0]) * nVal);

  75902.     if( apVal==0 ){

  75903.       rc = SQLITE_NOMEM_BKPT;

  75904.       goto value_from_function_out;

  75905.     }

  75906.     for(i=0; i<nVal; i++){

  75907.       rc = sqlite3ValueFromExpr(db, pList->a[i].pExpr, enc, aff, &apVal[i]);

  75908.       if( apVal[i]==0 || rc!=SQLITE_OK ) goto value_from_function_out;

  75909.     }

  75910.   }

  75911. 

  75912.   pVal = valueNew(db, pCtx);

  75913.   if( pVal==0 ){

  75914.     rc = SQLITE_NOMEM_BKPT;

  75915.     goto value_from_function_out;

  75916.   }

  75917. 

  75918.   assert( pCtx->pParse->rc==SQLITE_OK );

  75919.   memset(&ctx, 0, sizeof(ctx));

  75920.   ctx.pOut = pVal;

  75921.   ctx.pFunc = pFunc;

  75922.   pFunc->xSFunc(&ctx, nVal, apVal);

  75923.   if( ctx.isError ){

  75924.     rc = ctx.isError;

  75925.     sqlite3ErrorMsg(pCtx->pParse, "%s", sqlite3_value_text(pVal));

  75926.   }else{

  75927.     sqlite3ValueApplyAffinity(pVal, aff, SQLITE_UTF8);

  75928.     assert( rc==SQLITE_OK );

  75929.     rc = sqlite3VdbeChangeEncoding(pVal, enc);

  75930.     if( rc==SQLITE_OK && sqlite3VdbeMemTooBig(pVal) ){

  75931.       rc = SQLITE_TOOBIG;

  75932.       pCtx->pParse->nErr++;

  75933.     }

  75934.   }

  75935.   pCtx->pParse->rc = rc;

  75936. 

  75937.  value_from_function_out:

  75938.   if( rc!=SQLITE_OK ){

  75939.     pVal = 0;

  75940.   }

  75941.   if( apVal ){

  75942.     for(i=0; i<nVal; i++){

  75943.       sqlite3ValueFree(apVal[i]);

  75944.     }

  75945.     sqlite3DbFreeNN(db, apVal);

  75946.   }

  75947. 

  75948.   *ppVal = pVal;

  75949.   return rc;

  75950. }

  75951. #else

  75952. # define valueFromFunction(a,b,c,d,e,f) SQLITE_OK

  75953. #endif /* defined(SQLITE_ENABLE_STAT3_OR_STAT4) */

  75954. 

  75955. /*

  75956. ** Extract a value from the supplied expression in the manner described

  75957. ** above sqlite3ValueFromExpr(). Allocate the sqlite3_value object

  75958. ** using valueNew().

  75959. **

  75960. ** If pCtx is NULL and an error occurs after the sqlite3_value object

  75961. ** has been allocated, it is freed before returning. Or, if pCtx is not

  75962. ** NULL, it is assumed that the caller will free any allocated object

  75963. ** in all cases.

  75964. */

  75965. static int valueFromExpr(

  75966.   sqlite3 *db,                    /* The database connection */

  75967.   Expr *pExpr,                    /* The expression to evaluate */

  75968.   u8 enc,                         /* Encoding to use */

  75969.   u8 affinity,                    /* Affinity to use */

  75970.   sqlite3_value **ppVal,          /* Write the new value here */

  75971.   struct ValueNewStat4Ctx *pCtx   /* Second argument for valueNew() */

  75972. ){

  75973.   int op;

  75974.   char *zVal = 0;

  75975.   sqlite3_value *pVal = 0;

  75976.   int negInt = 1;

  75977.   const char *zNeg = "";

  75978.   int rc = SQLITE_OK;

  75979. 

  75980.   assert( pExpr!=0 );

  75981.   while( (op = pExpr->op)==TK_UPLUS || op==TK_SPAN ) pExpr = pExpr->pLeft;

  75982. #if defined(SQLITE_ENABLE_STAT3_OR_STAT4)

  75983.   if( op==TK_REGISTER ) op = pExpr->op2;

  75984. #else

  75985.   if( NEVER(op==TK_REGISTER) ) op = pExpr->op2;

  75986. #endif

  75987. 

  75988.   /* Compressed expressions only appear when parsing the DEFAULT clause

  75989.   ** on a table column definition, and hence only when pCtx==0.  This

  75990.   ** check ensures that an EP_TokenOnly expression is never passed down

  75991.   ** into valueFromFunction(). */

  75992.   assert( (pExpr->flags & EP_TokenOnly)==0 || pCtx==0 );

  75993. 

  75994.   if( op==TK_CAST ){

  75995.     u8 aff = sqlite3AffinityType(pExpr->u.zToken,0);

  75996.     rc = valueFromExpr(db, pExpr->pLeft, enc, aff, ppVal, pCtx);

  75997.     testcase( rc!=SQLITE_OK );

  75998.     if( *ppVal ){

  75999.       sqlite3VdbeMemCast(*ppVal, aff, SQLITE_UTF8);

  76000.       sqlite3ValueApplyAffinity(*ppVal, affinity, SQLITE_UTF8);

  76001.     }

  76002.     return rc;

  76003.   }

  76004. 

  76005.   /* Handle negative integers in a single step.  This is needed in the

  76006.   ** case when the value is -9223372036854775808.

  76007.   */

  76008.   if( op==TK_UMINUS

  76009.    && (pExpr->pLeft->op==TK_INTEGER || pExpr->pLeft->op==TK_FLOAT) ){

  76010.     pExpr = pExpr->pLeft;

  76011.     op = pExpr->op;

  76012.     negInt = -1;

  76013.     zNeg = "-";

  76014.   }

  76015. 

  76016.   if( op==TK_STRING || op==TK_FLOAT || op==TK_INTEGER ){

  76017.     pVal = valueNew(db, pCtx);

  76018.     if( pVal==0 ) goto no_mem;

  76019.     if( ExprHasProperty(pExpr, EP_IntValue) ){

  76020.       sqlite3VdbeMemSetInt64(pVal, (i64)pExpr->u.iValue*negInt);

  76021.     }else{

  76022.       zVal = sqlite3MPrintf(db, "%s%s", zNeg, pExpr->u.zToken);

  76023.       if( zVal==0 ) goto no_mem;

  76024.       sqlite3ValueSetStr(pVal, -1, zVal, SQLITE_UTF8, SQLITE_DYNAMIC);

  76025.     }

  76026.     if( (op==TK_INTEGER || op==TK_FLOAT ) && affinity==SQLITE_AFF_BLOB ){

  76027.       sqlite3ValueApplyAffinity(pVal, SQLITE_AFF_NUMERIC, SQLITE_UTF8);

  76028.     }else{

  76029.       sqlite3ValueApplyAffinity(pVal, affinity, SQLITE_UTF8);

  76030.     }

  76031.     assert( (pVal->flags & MEM_IntReal)==0 );

  76032.     if( pVal->flags & (MEM_Int|MEM_IntReal|MEM_Real) ){

  76033.       testcase( pVal->flags & MEM_Int );

  76034.       testcase( pVal->flags & MEM_Real );

  76035.       pVal->flags &= ~MEM_Str;

  76036.     }

  76037.     if( enc!=SQLITE_UTF8 ){

  76038.       rc = sqlite3VdbeChangeEncoding(pVal, enc);

  76039.     }

  76040.   }else if( op==TK_UMINUS ) {

  76041.     /* This branch happens for multiple negative signs.  Ex: -(-5) */

  76042.     if( SQLITE_OK==valueFromExpr(db,pExpr->pLeft,enc,affinity,&pVal,pCtx) 

  76043.      && pVal!=0

  76044.     ){

  76045.       sqlite3VdbeMemNumerify(pVal);

  76046.       if( pVal->flags & MEM_Real ){

  76047.         pVal->u.r = -pVal->u.r;

  76048.       }else if( pVal->u.i==SMALLEST_INT64 ){

  76049.         pVal->u.r = -(double)SMALLEST_INT64;

  76050.         MemSetTypeFlag(pVal, MEM_Real);

  76051.       }else{

  76052.         pVal->u.i = -pVal->u.i;

  76053.       }

  76054.       sqlite3ValueApplyAffinity(pVal, affinity, enc);

  76055.     }

  76056.   }else if( op==TK_NULL ){

  76057.     pVal = valueNew(db, pCtx);

  76058.     if( pVal==0 ) goto no_mem;

  76059.     sqlite3VdbeMemSetNull(pVal);

  76060.   }

  76061. #ifndef SQLITE_OMIT_BLOB_LITERAL

  76062.   else if( op==TK_BLOB ){

  76063.     int nVal;

  76064.     assert( pExpr->u.zToken[0]=='x' || pExpr->u.zToken[0]=='X' );

  76065.     assert( pExpr->u.zToken[1]=='\'' );

  76066.     pVal = valueNew(db, pCtx);

  76067.     if( !pVal ) goto no_mem;

  76068.     zVal = &pExpr->u.zToken[2];

  76069.     nVal = sqlite3Strlen30(zVal)-1;

  76070.     assert( zVal[nVal]=='\'' );

  76071.     sqlite3VdbeMemSetStr(pVal, sqlite3HexToBlob(db, zVal, nVal), nVal/2,

  76072.                          0, SQLITE_DYNAMIC);

  76073.   }

  76074. #endif

  76075. #ifdef SQLITE_ENABLE_STAT3_OR_STAT4

  76076.   else if( op==TK_FUNCTION && pCtx!=0 ){

  76077.     rc = valueFromFunction(db, pExpr, enc, affinity, &pVal, pCtx);

  76078.   }

  76079. #endif

  76080.   else if( op==TK_TRUEFALSE ){

  76081.     pVal = valueNew(db, pCtx);

  76082.     if( pVal ){

  76083.       pVal->flags = MEM_Int;

  76084.       pVal->u.i = pExpr->u.zToken[4]==0;

  76085.     }

  76086.   }

  76087. 

  76088.   *ppVal = pVal;

  76089.   return rc;

  76090. 

  76091. no_mem:

  76092. #ifdef SQLITE_ENABLE_STAT3_OR_STAT4

  76093.   if( pCtx==0 || pCtx->pParse->nErr==0 )

  76094. #endif

  76095.     sqlite3OomFault(db);

  76096.   sqlite3DbFree(db, zVal);

  76097.   assert( *ppVal==0 );

  76098. #ifdef SQLITE_ENABLE_STAT3_OR_STAT4

  76099.   if( pCtx==0 ) sqlite3ValueFree(pVal);

  76100. #else

  76101.   assert( pCtx==0 ); sqlite3ValueFree(pVal);

  76102. #endif

  76103.   return SQLITE_NOMEM_BKPT;

  76104. }

  76105. 

  76106. /*

  76107. ** Create a new sqlite3_value object, containing the value of pExpr.

  76108. **

  76109. ** This only works for very simple expressions that consist of one constant

  76110. ** token (i.e. "5", "5.1", "'a string'"). If the expression can

  76111. ** be converted directly into a value, then the value is allocated and

  76112. ** a pointer written to *ppVal. The caller is responsible for deallocating

  76113. ** the value by passing it to sqlite3ValueFree() later on. If the expression

  76114. ** cannot be converted to a value, then *ppVal is set to NULL.

  76115. */

  76116. SQLITE_PRIVATE int sqlite3ValueFromExpr(

  76117.   sqlite3 *db,              /* The database connection */

  76118.   Expr *pExpr,              /* The expression to evaluate */

  76119.   u8 enc,                   /* Encoding to use */

  76120.   u8 affinity,              /* Affinity to use */

  76121.   sqlite3_value **ppVal     /* Write the new value here */

  76122. ){

  76123.   return pExpr ? valueFromExpr(db, pExpr, enc, affinity, ppVal, 0) : 0;

  76124. }

  76125. 

  76126. #ifdef SQLITE_ENABLE_STAT3_OR_STAT4

  76127. /*

  76128. ** The implementation of the sqlite_record() function. This function accepts

  76129. ** a single argument of any type. The return value is a formatted database 

  76130. ** record (a blob) containing the argument value.

  76131. **

  76132. ** This is used to convert the value stored in the 'sample' column of the

  76133. ** sqlite_stat3 table to the record format SQLite uses internally.

  76134. */

  76135. static void recordFunc(

  76136.   sqlite3_context *context,

  76137.   int argc,

  76138.   sqlite3_value **argv

  76139. ){

  76140.   const int file_format = 1;

  76141.   u32 iSerial;                    /* Serial type */

  76142.   int nSerial;                    /* Bytes of space for iSerial as varint */

  76143.   u32 nVal;                       /* Bytes of space required for argv[0] */

  76144.   int nRet;

  76145.   sqlite3 *db;

  76146.   u8 *aRet;

  76147. 

  76148.   UNUSED_PARAMETER( argc );

  76149.   iSerial = sqlite3VdbeSerialType(argv[0], file_format, &nVal);

  76150.   nSerial = sqlite3VarintLen(iSerial);

  76151.   db = sqlite3_context_db_handle(context);

  76152. 

  76153.   nRet = 1 + nSerial + nVal;

  76154.   aRet = sqlite3DbMallocRawNN(db, nRet);

  76155.   if( aRet==0 ){

  76156.     sqlite3_result_error_nomem(context);

  76157.   }else{

  76158.     aRet[0] = nSerial+1;

  76159.     putVarint32(&aRet[1], iSerial);

  76160.     sqlite3VdbeSerialPut(&aRet[1+nSerial], argv[0], iSerial);

  76161.     sqlite3_result_blob(context, aRet, nRet, SQLITE_TRANSIENT);

  76162.     sqlite3DbFreeNN(db, aRet);

  76163.   }

  76164. }

  76165. 

  76166. /*

  76167. ** Register built-in functions used to help read ANALYZE data.

  76168. */

  76169. SQLITE_PRIVATE void sqlite3AnalyzeFunctions(void){

  76170.   static FuncDef aAnalyzeTableFuncs[] = {

  76171.     FUNCTION(sqlite_record,   1, 0, 0, recordFunc),

  76172.   };

  76173.   sqlite3InsertBuiltinFuncs(aAnalyzeTableFuncs, ArraySize(aAnalyzeTableFuncs));

  76174. }

  76175. 

  76176. /*

  76177. ** Attempt to extract a value from pExpr and use it to construct *ppVal.

  76178. **

  76179. ** If pAlloc is not NULL, then an UnpackedRecord object is created for

  76180. ** pAlloc if one does not exist and the new value is added to the

  76181. ** UnpackedRecord object.

  76182. **

  76183. ** A value is extracted in the following cases:

  76184. **

  76185. **  * (pExpr==0). In this case the value is assumed to be an SQL NULL,

  76186. **

  76187. **  * The expression is a bound variable, and this is a reprepare, or

  76188. **

  76189. **  * The expression is a literal value.

  76190. **

  76191. ** On success, *ppVal is made to point to the extracted value.  The caller

  76192. ** is responsible for ensuring that the value is eventually freed.

  76193. */

  76194. static int stat4ValueFromExpr(

  76195.   Parse *pParse,                  /* Parse context */

  76196.   Expr *pExpr,                    /* The expression to extract a value from */

  76197.   u8 affinity,                    /* Affinity to use */

  76198.   struct ValueNewStat4Ctx *pAlloc,/* How to allocate space.  Or NULL */

  76199.   sqlite3_value **ppVal           /* OUT: New value object (or NULL) */

  76200. ){

  76201.   int rc = SQLITE_OK;

  76202.   sqlite3_value *pVal = 0;

  76203.   sqlite3 *db = pParse->db;

  76204. 

  76205.   /* Skip over any TK_COLLATE nodes */

  76206.   pExpr = sqlite3ExprSkipCollate(pExpr);

  76207. 

  76208.   assert( pExpr==0 || pExpr->op!=TK_REGISTER || pExpr->op2!=TK_VARIABLE );

  76209.   if( !pExpr ){

  76210.     pVal = valueNew(db, pAlloc);

  76211.     if( pVal ){

  76212.       sqlite3VdbeMemSetNull((Mem*)pVal);

  76213.     }

  76214.   }else if( pExpr->op==TK_VARIABLE && (db->flags & SQLITE_EnableQPSG)==0 ){

  76215.     Vdbe *v;

  76216.     int iBindVar = pExpr->iColumn;

  76217.     sqlite3VdbeSetVarmask(pParse->pVdbe, iBindVar);

  76218.     if( (v = pParse->pReprepare)!=0 ){

  76219.       pVal = valueNew(db, pAlloc);

  76220.       if( pVal ){

  76221.         rc = sqlite3VdbeMemCopy((Mem*)pVal, &v->aVar[iBindVar-1]);

  76222.         sqlite3ValueApplyAffinity(pVal, affinity, ENC(db));

  76223.         pVal->db = pParse->db;

  76224.       }

  76225.     }

  76226.   }else{

  76227.     rc = valueFromExpr(db, pExpr, ENC(db), affinity, &pVal, pAlloc);

  76228.   }

  76229. 

  76230.   assert( pVal==0 || pVal->db==db );

  76231.   *ppVal = pVal;

  76232.   return rc;

  76233. }

  76234. 

  76235. /*

  76236. ** This function is used to allocate and populate UnpackedRecord 

  76237. ** structures intended to be compared against sample index keys stored 

  76238. ** in the sqlite_stat4 table.

  76239. **

  76240. ** A single call to this function populates zero or more fields of the

  76241. ** record starting with field iVal (fields are numbered from left to

  76242. ** right starting with 0). A single field is populated if:

  76243. **

  76244. **  * (pExpr==0). In this case the value is assumed to be an SQL NULL,

  76245. **

  76246. **  * The expression is a bound variable, and this is a reprepare, or

  76247. **

  76248. **  * The sqlite3ValueFromExpr() function is able to extract a value 

  76249. **    from the expression (i.e. the expression is a literal value).

  76250. **

  76251. ** Or, if pExpr is a TK_VECTOR, one field is populated for each of the

  76252. ** vector components that match either of the two latter criteria listed

  76253. ** above.

  76254. **

  76255. ** Before any value is appended to the record, the affinity of the 

  76256. ** corresponding column within index pIdx is applied to it. Before

  76257. ** this function returns, output parameter *pnExtract is set to the

  76258. ** number of values appended to the record.

  76259. **

  76260. ** When this function is called, *ppRec must either point to an object

  76261. ** allocated by an earlier call to this function, or must be NULL. If it

  76262. ** is NULL and a value can be successfully extracted, a new UnpackedRecord

  76263. ** is allocated (and *ppRec set to point to it) before returning.

  76264. **

  76265. ** Unless an error is encountered, SQLITE_OK is returned. It is not an

  76266. ** error if a value cannot be extracted from pExpr. If an error does

  76267. ** occur, an SQLite error code is returned.

  76268. */

  76269. SQLITE_PRIVATE int sqlite3Stat4ProbeSetValue(

  76270.   Parse *pParse,                  /* Parse context */

  76271.   Index *pIdx,                    /* Index being probed */

  76272.   UnpackedRecord **ppRec,         /* IN/OUT: Probe record */

  76273.   Expr *pExpr,                    /* The expression to extract a value from */

  76274.   int nElem,                      /* Maximum number of values to append */

  76275.   int iVal,                       /* Array element to populate */

  76276.   int *pnExtract                  /* OUT: Values appended to the record */

  76277. ){

  76278.   int rc = SQLITE_OK;

  76279.   int nExtract = 0;

  76280. 

  76281.   if( pExpr==0 || pExpr->op!=TK_SELECT ){

  76282.     int i;

  76283.     struct ValueNewStat4Ctx alloc;

  76284. 

  76285.     alloc.pParse = pParse;

  76286.     alloc.pIdx = pIdx;

  76287.     alloc.ppRec = ppRec;

  76288. 

  76289.     for(i=0; i<nElem; i++){

  76290.       sqlite3_value *pVal = 0;

  76291.       Expr *pElem = (pExpr ? sqlite3VectorFieldSubexpr(pExpr, i) : 0);

  76292.       u8 aff = sqlite3IndexColumnAffinity(pParse->db, pIdx, iVal+i);

  76293.       alloc.iVal = iVal+i;

  76294.       rc = stat4ValueFromExpr(pParse, pElem, aff, &alloc, &pVal);

  76295.       if( !pVal ) break;

  76296.       nExtract++;

  76297.     }

  76298.   }

  76299. 

  76300.   *pnExtract = nExtract;

  76301.   return rc;

  76302. }

  76303. 

  76304. /*

  76305. ** Attempt to extract a value from expression pExpr using the methods

  76306. ** as described for sqlite3Stat4ProbeSetValue() above. 

  76307. **

  76308. ** If successful, set *ppVal to point to a new value object and return 

  76309. ** SQLITE_OK. If no value can be extracted, but no other error occurs

  76310. ** (e.g. OOM), return SQLITE_OK and set *ppVal to NULL. Or, if an error

  76311. ** does occur, return an SQLite error code. The final value of *ppVal

  76312. ** is undefined in this case.

  76313. */

  76314. SQLITE_PRIVATE int sqlite3Stat4ValueFromExpr(

  76315.   Parse *pParse,                  /* Parse context */

  76316.   Expr *pExpr,                    /* The expression to extract a value from */

  76317.   u8 affinity,                    /* Affinity to use */

  76318.   sqlite3_value **ppVal           /* OUT: New value object (or NULL) */

  76319. ){

  76320.   return stat4ValueFromExpr(pParse, pExpr, affinity, 0, ppVal);

  76321. }

  76322. 

  76323. /*

  76324. ** Extract the iCol-th column from the nRec-byte record in pRec.  Write

  76325. ** the column value into *ppVal.  If *ppVal is initially NULL then a new

  76326. ** sqlite3_value object is allocated.

  76327. **

  76328. ** If *ppVal is initially NULL then the caller is responsible for 

  76329. ** ensuring that the value written into *ppVal is eventually freed.

  76330. */

  76331. SQLITE_PRIVATE int sqlite3Stat4Column(

  76332.   sqlite3 *db,                    /* Database handle */

  76333.   const void *pRec,               /* Pointer to buffer containing record */

  76334.   int nRec,                       /* Size of buffer pRec in bytes */

  76335.   int iCol,                       /* Column to extract */

  76336.   sqlite3_value **ppVal           /* OUT: Extracted value */

  76337. ){

  76338.   u32 t = 0;                      /* a column type code */

  76339.   int nHdr;                       /* Size of the header in the record */

  76340.   int iHdr;                       /* Next unread header byte */

  76341.   int iField;                     /* Next unread data byte */

  76342.   int szField = 0;                /* Size of the current data field */

  76343.   int i;                          /* Column index */

  76344.   u8 *a = (u8*)pRec;              /* Typecast byte array */

  76345.   Mem *pMem = *ppVal;             /* Write result into this Mem object */

  76346. 

  76347.   assert( iCol>0 );

  76348.   iHdr = getVarint32(a, nHdr);

  76349.   if( nHdr>nRec || iHdr>=nHdr ) return SQLITE_CORRUPT_BKPT;

  76350.   iField = nHdr;

  76351.   for(i=0; i<=iCol; i++){

  76352.     iHdr += getVarint32(&a[iHdr], t);

  76353.     testcase( iHdr==nHdr );

  76354.     testcase( iHdr==nHdr+1 );

  76355.     if( iHdr>nHdr ) return SQLITE_CORRUPT_BKPT;

  76356.     szField = sqlite3VdbeSerialTypeLen(t);

  76357.     iField += szField;

  76358.   }

  76359.   testcase( iField==nRec );

  76360.   testcase( iField==nRec+1 );

  76361.   if( iField>nRec ) return SQLITE_CORRUPT_BKPT;

  76362.   if( pMem==0 ){

  76363.     pMem = *ppVal = sqlite3ValueNew(db);

  76364.     if( pMem==0 ) return SQLITE_NOMEM_BKPT;

  76365.   }

  76366.   sqlite3VdbeSerialGet(&a[iField-szField], t, pMem);

  76367.   pMem->enc = ENC(db);

  76368.   return SQLITE_OK;

  76369. }

  76370. 

  76371. /*

  76372. ** Unless it is NULL, the argument must be an UnpackedRecord object returned

  76373. ** by an earlier call to sqlite3Stat4ProbeSetValue(). This call deletes

  76374. ** the object.

  76375. */

  76376. SQLITE_PRIVATE void sqlite3Stat4ProbeFree(UnpackedRecord *pRec){

  76377.   if( pRec ){

  76378.     int i;

  76379.     int nCol = pRec->pKeyInfo->nAllField;

  76380.     Mem *aMem = pRec->aMem;

  76381.     sqlite3 *db = aMem[0].db;

  76382.     for(i=0; i<nCol; i++){

  76383.       sqlite3VdbeMemRelease(&aMem[i]);

  76384.     }

  76385.     sqlite3KeyInfoUnref(pRec->pKeyInfo);

  76386.     sqlite3DbFreeNN(db, pRec);

  76387.   }

  76388. }

  76389. #endif /* ifdef SQLITE_ENABLE_STAT4 */

  76390. 

  76391. /*

  76392. ** Change the string value of an sqlite3_value object

  76393. */

  76394. SQLITE_PRIVATE void sqlite3ValueSetStr(

  76395.   sqlite3_value *v,     /* Value to be set */

  76396.   int n,                /* Length of string z */

  76397.   const void *z,        /* Text of the new string */

  76398.   u8 enc,               /* Encoding to use */

  76399.   void (*xDel)(void*)   /* Destructor for the string */

  76400. ){

  76401.   if( v ) sqlite3VdbeMemSetStr((Mem *)v, z, n, enc, xDel);

  76402. }

  76403. 

  76404. /*

  76405. ** Free an sqlite3_value object

  76406. */

  76407. SQLITE_PRIVATE void sqlite3ValueFree(sqlite3_value *v){

  76408.   if( !v ) return;

  76409.   sqlite3VdbeMemRelease((Mem *)v);

  76410.   sqlite3DbFreeNN(((Mem*)v)->db, v);

  76411. }

  76412. 

  76413. /*

  76414. ** The sqlite3ValueBytes() routine returns the number of bytes in the

  76415. ** sqlite3_value object assuming that it uses the encoding "enc".

  76416. ** The valueBytes() routine is a helper function.

  76417. */

  76418. static SQLITE_NOINLINE int valueBytes(sqlite3_value *pVal, u8 enc){

  76419.   return valueToText(pVal, enc)!=0 ? pVal->n : 0;

  76420. }

  76421. SQLITE_PRIVATE int sqlite3ValueBytes(sqlite3_value *pVal, u8 enc){

  76422.   Mem *p = (Mem*)pVal;

  76423.   assert( (p->flags & MEM_Null)==0 || (p->flags & (MEM_Str|MEM_Blob))==0 );

  76424.   if( (p->flags & MEM_Str)!=0 && pVal->enc==enc ){

  76425.     return p->n;

  76426.   }

  76427.   if( (p->flags & MEM_Blob)!=0 ){

  76428.     if( p->flags & MEM_Zero ){

  76429.       return p->n + p->u.nZero;

  76430.     }else{

  76431.       return p->n;

  76432.     }

  76433.   }

  76434.   if( p->flags & MEM_Null ) return 0;

  76435.   return valueBytes(pVal, enc);

  76436. }

  76437. 

  76438. /************** End of vdbemem.c *********************************************/

  76439. /************** Begin file vdbeaux.c *****************************************/

  76440. /*

  76441. ** 2003 September 6

  76442. **

  76443. ** The author disclaims copyright to this source code.  In place of

  76444. ** a legal notice, here is a blessing:

  76445. **

  76446. **    May you do good and not evil.

  76447. **    May you find forgiveness for yourself and forgive others.

  76448. **    May you share freely, never taking more than you give.

  76449. **

  76450. *************************************************************************

  76451. ** This file contains code used for creating, destroying, and populating

  76452. ** a VDBE (or an "sqlite3_stmt" as it is known to the outside world.) 

  76453. */

  76454. /* #include "sqliteInt.h" */

  76455. /* #include "vdbeInt.h" */

  76456. 

  76457. /*

  76458. ** Create a new virtual database engine.

  76459. */

  76460. SQLITE_PRIVATE Vdbe *sqlite3VdbeCreate(Parse *pParse){

  76461.   sqlite3 *db = pParse->db;

  76462.   Vdbe *p;

  76463.   p = sqlite3DbMallocRawNN(db, sizeof(Vdbe) );

  76464.   if( p==0 ) return 0;

  76465.   memset(&p->aOp, 0, sizeof(Vdbe)-offsetof(Vdbe,aOp));

  76466.   p->db = db;

  76467.   if( db->pVdbe ){

  76468.     db->pVdbe->pPrev = p;

  76469.   }

  76470.   p->pNext = db->pVdbe;

  76471.   p->pPrev = 0;

  76472.   db->pVdbe = p;

  76473.   p->magic = VDBE_MAGIC_INIT;

  76474.   p->pParse = pParse;

  76475.   pParse->pVdbe = p;

  76476.   assert( pParse->aLabel==0 );

  76477.   assert( pParse->nLabel==0 );

  76478.   assert( p->nOpAlloc==0 );

  76479.   assert( pParse->szOpAlloc==0 );

  76480.   sqlite3VdbeAddOp2(p, OP_Init, 0, 1);

  76481.   return p;

  76482. }

  76483. 

  76484. /*

  76485. ** Change the error string stored in Vdbe.zErrMsg

  76486. */

  76487. SQLITE_PRIVATE void sqlite3VdbeError(Vdbe *p, const char *zFormat, ...){

  76488.   va_list ap;

  76489.   sqlite3DbFree(p->db, p->zErrMsg);

  76490.   va_start(ap, zFormat);

  76491.   p->zErrMsg = sqlite3VMPrintf(p->db, zFormat, ap);

  76492.   va_end(ap);

  76493. }

  76494. 

  76495. /*

  76496. ** Remember the SQL string for a prepared statement.

  76497. */

  76498. SQLITE_PRIVATE void sqlite3VdbeSetSql(Vdbe *p, const char *z, int n, u8 prepFlags){

  76499.   if( p==0 ) return;

  76500.   p->prepFlags = prepFlags;

  76501.   if( (prepFlags & SQLITE_PREPARE_SAVESQL)==0 ){

  76502.     p->expmask = 0;

  76503.   }

  76504.   assert( p->zSql==0 );

  76505.   p->zSql = sqlite3DbStrNDup(p->db, z, n);

  76506. }

  76507. 

  76508. #ifdef SQLITE_ENABLE_NORMALIZE

  76509. /*

  76510. ** Add a new element to the Vdbe->pDblStr list.

  76511. */

  76512. SQLITE_PRIVATE void sqlite3VdbeAddDblquoteStr(sqlite3 *db, Vdbe *p, const char *z){

  76513.   if( p ){

  76514.     int n = sqlite3Strlen30(z);

  76515.     DblquoteStr *pStr = sqlite3DbMallocRawNN(db,

  76516.                             sizeof(*pStr)+n+1-sizeof(pStr->z));

  76517.     if( pStr ){

  76518.       pStr->pNextStr = p->pDblStr;

  76519.       p->pDblStr = pStr;

  76520.       memcpy(pStr->z, z, n+1);

  76521.     }

  76522.   }

  76523. }

  76524. #endif

  76525. 

  76526. #ifdef SQLITE_ENABLE_NORMALIZE

  76527. /*

  76528. ** zId of length nId is a double-quoted identifier.  Check to see if

  76529. ** that identifier is really used as a string literal.

  76530. */

  76531. SQLITE_PRIVATE int sqlite3VdbeUsesDoubleQuotedString(

  76532.   Vdbe *pVdbe,            /* The prepared statement */

  76533.   const char *zId         /* The double-quoted identifier, already dequoted */

  76534. ){

  76535.   DblquoteStr *pStr;

  76536.   assert( zId!=0 );

  76537.   if( pVdbe->pDblStr==0 ) return 0;

  76538.   for(pStr=pVdbe->pDblStr; pStr; pStr=pStr->pNextStr){

  76539.     if( strcmp(zId, pStr->z)==0 ) return 1;

  76540.   }

  76541.   return 0;

  76542. }

  76543. #endif

  76544. 

  76545. /*

  76546. ** Swap all content between two VDBE structures.

  76547. */

  76548. SQLITE_PRIVATE void sqlite3VdbeSwap(Vdbe *pA, Vdbe *pB){

  76549.   Vdbe tmp, *pTmp;

  76550.   char *zTmp;

  76551.   assert( pA->db==pB->db );

  76552.   tmp = *pA;

  76553.   *pA = *pB;

  76554.   *pB = tmp;

  76555.   pTmp = pA->pNext;

  76556.   pA->pNext = pB->pNext;

  76557.   pB->pNext = pTmp;

  76558.   pTmp = pA->pPrev;

  76559.   pA->pPrev = pB->pPrev;

  76560.   pB->pPrev = pTmp;

  76561.   zTmp = pA->zSql;

  76562.   pA->zSql = pB->zSql;

  76563.   pB->zSql = zTmp;

  76564. #if 0

  76565.   zTmp = pA->zNormSql;

  76566.   pA->zNormSql = pB->zNormSql;

  76567.   pB->zNormSql = zTmp;

  76568. #endif

  76569.   pB->expmask = pA->expmask;

  76570.   pB->prepFlags = pA->prepFlags;

  76571.   memcpy(pB->aCounter, pA->aCounter, sizeof(pB->aCounter));

  76572.   pB->aCounter[SQLITE_STMTSTATUS_REPREPARE]++;

  76573. }

  76574. 

  76575. /*

  76576. ** Resize the Vdbe.aOp array so that it is at least nOp elements larger 

  76577. ** than its current size. nOp is guaranteed to be less than or equal

  76578. ** to 1024/sizeof(Op).

  76579. **

  76580. ** If an out-of-memory error occurs while resizing the array, return

  76581. ** SQLITE_NOMEM. In this case Vdbe.aOp and Vdbe.nOpAlloc remain 

  76582. ** unchanged (this is so that any opcodes already allocated can be 

  76583. ** correctly deallocated along with the rest of the Vdbe).

  76584. */

  76585. static int growOpArray(Vdbe *v, int nOp){

  76586.   VdbeOp *pNew;

  76587.   Parse *p = v->pParse;

  76588. 

  76589.   /* The SQLITE_TEST_REALLOC_STRESS compile-time option is designed to force

  76590.   ** more frequent reallocs and hence provide more opportunities for 

  76591.   ** simulated OOM faults.  SQLITE_TEST_REALLOC_STRESS is generally used

  76592.   ** during testing only.  With SQLITE_TEST_REALLOC_STRESS grow the op array

  76593.   ** by the minimum* amount required until the size reaches 512.  Normal

  76594.   ** operation (without SQLITE_TEST_REALLOC_STRESS) is to double the current

  76595.   ** size of the op array or add 1KB of space, whichever is smaller. */

  76596. #ifdef SQLITE_TEST_REALLOC_STRESS

  76597.   sqlite3_int64 nNew = (v->nOpAlloc>=512 ? 2*(sqlite3_int64)v->nOpAlloc

  76598.                         : (sqlite3_int64)v->nOpAlloc+nOp);

  76599. #else

  76600.   sqlite3_int64 nNew = (v->nOpAlloc ? 2*(sqlite3_int64)v->nOpAlloc

  76601.                         : (sqlite3_int64)(1024/sizeof(Op)));

  76602.   UNUSED_PARAMETER(nOp);

  76603. #endif

  76604. 

  76605.   /* Ensure that the size of a VDBE does not grow too large */

  76606.   if( nNew > p->db->aLimit[SQLITE_LIMIT_VDBE_OP] ){

  76607.     sqlite3OomFault(p->db);

  76608.     return SQLITE_NOMEM;

  76609.   }

  76610. 

  76611.   assert( nOp<=(1024/sizeof(Op)) );

  76612.   assert( nNew>=(v->nOpAlloc+nOp) );

  76613.   pNew = sqlite3DbRealloc(p->db, v->aOp, nNew*sizeof(Op));

  76614.   if( pNew ){

  76615.     p->szOpAlloc = sqlite3DbMallocSize(p->db, pNew);

  76616.     v->nOpAlloc = p->szOpAlloc/sizeof(Op);

  76617.     v->aOp = pNew;

  76618.   }

  76619.   return (pNew ? SQLITE_OK : SQLITE_NOMEM_BKPT);

  76620. }

  76621. 

  76622. #ifdef SQLITE_DEBUG

  76623. /* This routine is just a convenient place to set a breakpoint that will

  76624. ** fire after each opcode is inserted and displayed using

  76625. ** "PRAGMA vdbe_addoptrace=on".

  76626. */

  76627. static void test_addop_breakpoint(void){

  76628.   static int n = 0;

  76629.   n++;

  76630. }

  76631. #endif

  76632. 

  76633. /*

  76634. ** Add a new instruction to the list of instructions current in the

  76635. ** VDBE.  Return the address of the new instruction.

  76636. **

  76637. ** Parameters:

  76638. **

  76639. **    p               Pointer to the VDBE

  76640. **

  76641. **    op              The opcode for this instruction

  76642. **

  76643. **    p1, p2, p3      Operands

  76644. **

  76645. ** Use the sqlite3VdbeResolveLabel() function to fix an address and

  76646. ** the sqlite3VdbeChangeP4() function to change the value of the P4

  76647. ** operand.

  76648. */

  76649. static SQLITE_NOINLINE int growOp3(Vdbe *p, int op, int p1, int p2, int p3){

  76650.   assert( p->nOpAlloc<=p->nOp );

  76651.   if( growOpArray(p, 1) ) return 1;

  76652.   assert( p->nOpAlloc>p->nOp );

  76653.   return sqlite3VdbeAddOp3(p, op, p1, p2, p3);

  76654. }

  76655. SQLITE_PRIVATE int sqlite3VdbeAddOp3(Vdbe *p, int op, int p1, int p2, int p3){

  76656.   int i;

  76657.   VdbeOp *pOp;

  76658. 

  76659.   i = p->nOp;

  76660.   assert( p->magic==VDBE_MAGIC_INIT );

  76661.   assert( op>=0 && op<0xff );

  76662.   if( p->nOpAlloc<=i ){

  76663.     return growOp3(p, op, p1, p2, p3);

  76664.   }

  76665.   p->nOp++;

  76666.   pOp = &p->aOp[i];

  76667.   pOp->opcode = (u8)op;

  76668.   pOp->p5 = 0;

  76669.   pOp->p1 = p1;

  76670.   pOp->p2 = p2;

  76671.   pOp->p3 = p3;

  76672.   pOp->p4.p = 0;

  76673.   pOp->p4type = P4_NOTUSED;

  76674. #ifdef SQLITE_ENABLE_EXPLAIN_COMMENTS

  76675.   pOp->zComment = 0;

  76676. #endif

  76677. #ifdef SQLITE_DEBUG

  76678.   if( p->db->flags & SQLITE_VdbeAddopTrace ){

  76679.     sqlite3VdbePrintOp(0, i, &p->aOp[i]);

  76680.     test_addop_breakpoint();

  76681.   }

  76682. #endif

  76683. #ifdef VDBE_PROFILE

  76684.   pOp->cycles = 0;

  76685.   pOp->cnt = 0;

  76686. #endif

  76687. #ifdef SQLITE_VDBE_COVERAGE

  76688.   pOp->iSrcLine = 0;

  76689. #endif

  76690.   return i;

  76691. }

  76692. SQLITE_PRIVATE int sqlite3VdbeAddOp0(Vdbe *p, int op){

  76693.   return sqlite3VdbeAddOp3(p, op, 0, 0, 0);

  76694. }

  76695. SQLITE_PRIVATE int sqlite3VdbeAddOp1(Vdbe *p, int op, int p1){

  76696.   return sqlite3VdbeAddOp3(p, op, p1, 0, 0);

  76697. }

  76698. SQLITE_PRIVATE int sqlite3VdbeAddOp2(Vdbe *p, int op, int p1, int p2){

  76699.   return sqlite3VdbeAddOp3(p, op, p1, p2, 0);

  76700. }

  76701. 

  76702. /* Generate code for an unconditional jump to instruction iDest

  76703. */

  76704. SQLITE_PRIVATE int sqlite3VdbeGoto(Vdbe *p, int iDest){

  76705.   return sqlite3VdbeAddOp3(p, OP_Goto, 0, iDest, 0);

  76706. }

  76707. 

  76708. /* Generate code to cause the string zStr to be loaded into

  76709. ** register iDest

  76710. */

  76711. SQLITE_PRIVATE int sqlite3VdbeLoadString(Vdbe *p, int iDest, const char *zStr){

  76712.   return sqlite3VdbeAddOp4(p, OP_String8, 0, iDest, 0, zStr, 0);

  76713. }

  76714. 

  76715. /*

  76716. ** Generate code that initializes multiple registers to string or integer

  76717. ** constants.  The registers begin with iDest and increase consecutively.

  76718. ** One register is initialized for each characgter in zTypes[].  For each

  76719. ** "s" character in zTypes[], the register is a string if the argument is

  76720. ** not NULL, or OP_Null if the value is a null pointer.  For each "i" character

  76721. ** in zTypes[], the register is initialized to an integer.

  76722. **

  76723. ** If the input string does not end with "X" then an OP_ResultRow instruction

  76724. ** is generated for the values inserted.

  76725. */

  76726. SQLITE_PRIVATE void sqlite3VdbeMultiLoad(Vdbe *p, int iDest, const char *zTypes, ...){

  76727.   va_list ap;

  76728.   int i;

  76729.   char c;

  76730.   va_start(ap, zTypes);

  76731.   for(i=0; (c = zTypes[i])!=0; i++){

  76732.     if( c=='s' ){

  76733.       const char *z = va_arg(ap, const char*);

  76734.       sqlite3VdbeAddOp4(p, z==0 ? OP_Null : OP_String8, 0, iDest+i, 0, z, 0);

  76735.     }else if( c=='i' ){

  76736.       sqlite3VdbeAddOp2(p, OP_Integer, va_arg(ap, int), iDest+i);

  76737.     }else{

  76738.       goto skip_op_resultrow;

  76739.     }

  76740.   }

  76741.   sqlite3VdbeAddOp2(p, OP_ResultRow, iDest, i);

  76742. skip_op_resultrow:

  76743.   va_end(ap);

  76744. }

  76745. 

  76746. /*

  76747. ** Add an opcode that includes the p4 value as a pointer.

  76748. */

  76749. SQLITE_PRIVATE int sqlite3VdbeAddOp4(

  76750.   Vdbe *p,            /* Add the opcode to this VM */

  76751.   int op,             /* The new opcode */

  76752.   int p1,             /* The P1 operand */

  76753.   int p2,             /* The P2 operand */

  76754.   int p3,             /* The P3 operand */

  76755.   const char *zP4,    /* The P4 operand */

  76756.   int p4type          /* P4 operand type */

  76757. ){

  76758.   int addr = sqlite3VdbeAddOp3(p, op, p1, p2, p3);

  76759.   sqlite3VdbeChangeP4(p, addr, zP4, p4type);

  76760.   return addr;

  76761. }

  76762. 

  76763. /*

  76764. ** Add an opcode that includes the p4 value with a P4_INT64 or

  76765. ** P4_REAL type.

  76766. */

  76767. SQLITE_PRIVATE int sqlite3VdbeAddOp4Dup8(

  76768.   Vdbe *p,            /* Add the opcode to this VM */

  76769.   int op,             /* The new opcode */

  76770.   int p1,             /* The P1 operand */

  76771.   int p2,             /* The P2 operand */

  76772.   int p3,             /* The P3 operand */

  76773.   const u8 *zP4,      /* The P4 operand */

  76774.   int p4type          /* P4 operand type */

  76775. ){

  76776.   char *p4copy = sqlite3DbMallocRawNN(sqlite3VdbeDb(p), 8);

  76777.   if( p4copy ) memcpy(p4copy, zP4, 8);

  76778.   return sqlite3VdbeAddOp4(p, op, p1, p2, p3, p4copy, p4type);

  76779. }

  76780. 

  76781. #ifndef SQLITE_OMIT_EXPLAIN

  76782. /*

  76783. ** Return the address of the current EXPLAIN QUERY PLAN baseline.

  76784. ** 0 means "none".

  76785. */

  76786. SQLITE_PRIVATE int sqlite3VdbeExplainParent(Parse *pParse){

  76787.   VdbeOp *pOp;

  76788.   if( pParse->addrExplain==0 ) return 0;

  76789.   pOp = sqlite3VdbeGetOp(pParse->pVdbe, pParse->addrExplain);

  76790.   return pOp->p2;

  76791. }

  76792. 

  76793. /*

  76794. ** Set a debugger breakpoint on the following routine in order to

  76795. ** monitor the EXPLAIN QUERY PLAN code generation.

  76796. */

  76797. #if defined(SQLITE_DEBUG)

  76798. SQLITE_PRIVATE void sqlite3ExplainBreakpoint(const char *z1, const char *z2){

  76799.   (void)z1;

  76800.   (void)z2;

  76801. }

  76802. #endif

  76803. 

  76804. /*

  76805. ** Add a new OP_ opcode.

  76806. **

  76807. ** If the bPush flag is true, then make this opcode the parent for

  76808. ** subsequent Explains until sqlite3VdbeExplainPop() is called.

  76809. */

  76810. SQLITE_PRIVATE void sqlite3VdbeExplain(Parse *pParse, u8 bPush, const char *zFmt, ...){

  76811. #ifndef SQLITE_DEBUG

  76812.   /* Always include the OP_Explain opcodes if SQLITE_DEBUG is defined.

  76813.   ** But omit them (for performance) during production builds */

  76814.   if( pParse->explain==2 )

  76815. #endif

  76816.   {

  76817.     char *zMsg;

  76818.     Vdbe *v;

  76819.     va_list ap;

  76820.     int iThis;

  76821.     va_start(ap, zFmt);

  76822.     zMsg = sqlite3VMPrintf(pParse->db, zFmt, ap);

  76823.     va_end(ap);

  76824.     v = pParse->pVdbe;

  76825.     iThis = v->nOp;

  76826.     sqlite3VdbeAddOp4(v, OP_Explain, iThis, pParse->addrExplain, 0,

  76827.                       zMsg, P4_DYNAMIC);

  76828.     sqlite3ExplainBreakpoint(bPush?"PUSH":"", sqlite3VdbeGetOp(v,-1)->p4.z);

  76829.     if( bPush){

  76830.       pParse->addrExplain = iThis;

  76831.     }

  76832.   }

  76833. }

  76834. 

  76835. /*

  76836. ** Pop the EXPLAIN QUERY PLAN stack one level.

  76837. */

  76838. SQLITE_PRIVATE void sqlite3VdbeExplainPop(Parse *pParse){

  76839.   sqlite3ExplainBreakpoint("POP", 0);

  76840.   pParse->addrExplain = sqlite3VdbeExplainParent(pParse);

  76841. }

  76842. #endif /* SQLITE_OMIT_EXPLAIN */

  76843. 

  76844. /*

  76845. ** Add an OP_ParseSchema opcode.  This routine is broken out from

  76846. ** sqlite3VdbeAddOp4() since it needs to also needs to mark all btrees

  76847. ** as having been used.

  76848. **

  76849. ** The zWhere string must have been obtained from sqlite3_malloc().

  76850. ** This routine will take ownership of the allocated memory.

  76851. */

  76852. SQLITE_PRIVATE void sqlite3VdbeAddParseSchemaOp(Vdbe *p, int iDb, char *zWhere){

  76853.   int j;

  76854.   sqlite3VdbeAddOp4(p, OP_ParseSchema, iDb, 0, 0, zWhere, P4_DYNAMIC);

  76855.   for(j=0; j<p->db->nDb; j++) sqlite3VdbeUsesBtree(p, j);

  76856. }

  76857. 

  76858. /*

  76859. ** Add an opcode that includes the p4 value as an integer.

  76860. */

  76861. SQLITE_PRIVATE int sqlite3VdbeAddOp4Int(

  76862.   Vdbe *p,            /* Add the opcode to this VM */

  76863.   int op,             /* The new opcode */

  76864.   int p1,             /* The P1 operand */

  76865.   int p2,             /* The P2 operand */

  76866.   int p3,             /* The P3 operand */

  76867.   int p4              /* The P4 operand as an integer */

  76868. ){

  76869.   int addr = sqlite3VdbeAddOp3(p, op, p1, p2, p3);

  76870.   if( p->db->mallocFailed==0 ){

  76871.     VdbeOp *pOp = &p->aOp[addr];

  76872.     pOp->p4type = P4_INT32;

  76873.     pOp->p4.i = p4;

  76874.   }

  76875.   return addr;

  76876. }

  76877. 

  76878. /* Insert the end of a co-routine

  76879. */

  76880. SQLITE_PRIVATE void sqlite3VdbeEndCoroutine(Vdbe *v, int regYield){

  76881.   sqlite3VdbeAddOp1(v, OP_EndCoroutine, regYield);

  76882. 

  76883.   /* Clear the temporary register cache, thereby ensuring that each

  76884.   ** co-routine has its own independent set of registers, because co-routines

  76885.   ** might expect their registers to be preserved across an OP_Yield, and

  76886.   ** that could cause problems if two or more co-routines are using the same

  76887.   ** temporary register.

  76888.   */

  76889.   v->pParse->nTempReg = 0;

  76890.   v->pParse->nRangeReg = 0;

  76891. }

  76892. 

  76893. /*

  76894. ** Create a new symbolic label for an instruction that has yet to be

  76895. ** coded.  The symbolic label is really just a negative number.  The

  76896. ** label can be used as the P2 value of an operation.  Later, when

  76897. ** the label is resolved to a specific address, the VDBE will scan

  76898. ** through its operation list and change all values of P2 which match

  76899. ** the label into the resolved address.

  76900. **

  76901. ** The VDBE knows that a P2 value is a label because labels are

  76902. ** always negative and P2 values are suppose to be non-negative.

  76903. ** Hence, a negative P2 value is a label that has yet to be resolved.

  76904. ** (Later:) This is only true for opcodes that have the OPFLG_JUMP

  76905. ** property.

  76906. **

  76907. ** Variable usage notes:

  76908. **

  76909. **     Parse.aLabel[x]     Stores the address that the x-th label resolves

  76910. **                         into.  For testing (SQLITE_DEBUG), unresolved

  76911. **                         labels stores -1, but that is not required.

  76912. **     Parse.nLabelAlloc   Number of slots allocated to Parse.aLabel[]

  76913. **     Parse.nLabel        The *negative* of the number of labels that have

  76914. **                         been issued.  The negative is stored because

  76915. **                         that gives a performance improvement over storing

  76916. **                         the equivalent positive value.

  76917. */

  76918. SQLITE_PRIVATE int sqlite3VdbeMakeLabel(Parse *pParse){

  76919.   return --pParse->nLabel;

  76920. }

  76921. 

  76922. /*

  76923. ** Resolve label "x" to be the address of the next instruction to

  76924. ** be inserted.  The parameter "x" must have been obtained from

  76925. ** a prior call to sqlite3VdbeMakeLabel().

  76926. */

  76927. static SQLITE_NOINLINE void resizeResolveLabel(Parse *p, Vdbe *v, int j){

  76928.   int nNewSize = 10 - p->nLabel;

  76929.   p->aLabel = sqlite3DbReallocOrFree(p->db, p->aLabel,

  76930.                      nNewSize*sizeof(p->aLabel[0]));

  76931.   if( p->aLabel==0 ){

  76932.     p->nLabelAlloc = 0;

  76933.   }else{

  76934. #ifdef SQLITE_DEBUG

  76935.     int i;

  76936.     for(i=p->nLabelAlloc; i<nNewSize; i++) p->aLabel[i] = -1;

  76937. #endif

  76938.     p->nLabelAlloc = nNewSize;

  76939.     p->aLabel[j] = v->nOp;

  76940.   }

  76941. }

  76942. SQLITE_PRIVATE void sqlite3VdbeResolveLabel(Vdbe *v, int x){

  76943.   Parse *p = v->pParse;

  76944.   int j = ADDR(x);

  76945.   assert( v->magic==VDBE_MAGIC_INIT );

  76946.   assert( j<-p->nLabel );

  76947.   assert( j>=0 );

  76948. #ifdef SQLITE_DEBUG

  76949.   if( p->db->flags & SQLITE_VdbeAddopTrace ){

  76950.     printf("RESOLVE LABEL %d to %d\n", x, v->nOp);

  76951.   }

  76952. #endif

  76953.   if( p->nLabelAlloc + p->nLabel < 0 ){

  76954.     resizeResolveLabel(p,v,j);

  76955.   }else{

  76956.     assert( p->aLabel[j]==(-1) ); /* Labels may only be resolved once */

  76957.     p->aLabel[j] = v->nOp;

  76958.   }

  76959. }

  76960. 

  76961. /*

  76962. ** Mark the VDBE as one that can only be run one time.

  76963. */

  76964. SQLITE_PRIVATE void sqlite3VdbeRunOnlyOnce(Vdbe *p){

  76965.   p->runOnlyOnce = 1;

  76966. }

  76967. 

  76968. /*

  76969. ** Mark the VDBE as one that can only be run multiple times.

  76970. */

  76971. SQLITE_PRIVATE void sqlite3VdbeReusable(Vdbe *p){

  76972.   p->runOnlyOnce = 0;

  76973. }

  76974. 

  76975. #ifdef SQLITE_DEBUG /* sqlite3AssertMayAbort() logic */

  76976. 

  76977. /*

  76978. ** The following type and function are used to iterate through all opcodes

  76979. ** in a Vdbe main program and each of the sub-programs (triggers) it may 

  76980. ** invoke directly or indirectly. It should be used as follows:

  76981. **

  76982. **   Op *pOp;

  76983. **   VdbeOpIter sIter;

  76984. **

  76985. **   memset(&sIter, 0, sizeof(sIter));

  76986. **   sIter.v = v;                            // v is of type Vdbe* 

  76987. **   while( (pOp = opIterNext(&sIter)) ){

  76988. **     // Do something with pOp

  76989. **   }

  76990. **   sqlite3DbFree(v->db, sIter.apSub);

  76991. ** 

  76992. */

  76993. typedef struct VdbeOpIter VdbeOpIter;

  76994. struct VdbeOpIter {

  76995.   Vdbe *v;                   /* Vdbe to iterate through the opcodes of */

  76996.   SubProgram **apSub;        /* Array of subprograms */

  76997.   int nSub;                  /* Number of entries in apSub */

  76998.   int iAddr;                 /* Address of next instruction to return */

  76999.   int iSub;                  /* 0 = main program, 1 = first sub-program etc. */

  77000. };

  77001. static Op *opIterNext(VdbeOpIter *p){

  77002.   Vdbe *v = p->v;

  77003.   Op *pRet = 0;

  77004.   Op *aOp;

  77005.   int nOp;

  77006. 

  77007.   if( p->iSub<=p->nSub ){

  77008. 

  77009.     if( p->iSub==0 ){

  77010.       aOp = v->aOp;

  77011.       nOp = v->nOp;

  77012.     }else{

  77013.       aOp = p->apSub[p->iSub-1]->aOp;

  77014.       nOp = p->apSub[p->iSub-1]->nOp;

  77015.     }

  77016.     assert( p->iAddr<nOp );

  77017. 

  77018.     pRet = &aOp[p->iAddr];

  77019.     p->iAddr++;

  77020.     if( p->iAddr==nOp ){

  77021.       p->iSub++;

  77022.       p->iAddr = 0;

  77023.     }

  77024.   

  77025.     if( pRet->p4type==P4_SUBPROGRAM ){

  77026.       int nByte = (p->nSub+1)*sizeof(SubProgram*);

  77027.       int j;

  77028.       for(j=0; j<p->nSub; j++){

  77029.         if( p->apSub[j]==pRet->p4.pProgram ) break;

  77030.       }

  77031.       if( j==p->nSub ){

  77032.         p->apSub = sqlite3DbReallocOrFree(v->db, p->apSub, nByte);

  77033.         if( !p->apSub ){

  77034.           pRet = 0;

  77035.         }else{

  77036.           p->apSub[p->nSub++] = pRet->p4.pProgram;

  77037.         }

  77038.       }

  77039.     }

  77040.   }

  77041. 

  77042.   return pRet;

  77043. }

  77044. 

  77045. /*

  77046. ** Check if the program stored in the VM associated with pParse may

  77047. ** throw an ABORT exception (causing the statement, but not entire transaction

  77048. ** to be rolled back). This condition is true if the main program or any

  77049. ** sub-programs contains any of the following:

  77050. **

  77051. **   *  OP_Halt with P1=SQLITE_CONSTRAINT and P2=OE_Abort.

  77052. **   *  OP_HaltIfNull with P1=SQLITE_CONSTRAINT and P2=OE_Abort.

  77053. **   *  OP_Destroy

  77054. **   *  OP_VUpdate

  77055. **   *  OP_VRename

  77056. **   *  OP_FkCounter with P2==0 (immediate foreign key constraint)

  77057. **   *  OP_CreateBtree/BTREE_INTKEY and OP_InitCoroutine 

  77058. **      (for CREATE TABLE AS SELECT ...)

  77059. **

  77060. ** Then check that the value of Parse.mayAbort is true if an

  77061. ** ABORT may be thrown, or false otherwise. Return true if it does

  77062. ** match, or false otherwise. This function is intended to be used as

  77063. ** part of an assert statement in the compiler. Similar to:

  77064. **

  77065. **   assert( sqlite3VdbeAssertMayAbort(pParse->pVdbe, pParse->mayAbort) );

  77066. */

  77067. SQLITE_PRIVATE int sqlite3VdbeAssertMayAbort(Vdbe *v, int mayAbort){

  77068.   int hasAbort = 0;

  77069.   int hasFkCounter = 0;

  77070.   int hasCreateTable = 0;

  77071.   int hasCreateIndex = 0;

  77072.   int hasInitCoroutine = 0;

  77073.   Op *pOp;

  77074.   VdbeOpIter sIter;

  77075.   memset(&sIter, 0, sizeof(sIter));

  77076.   sIter.v = v;

  77077. 

  77078.   while( (pOp = opIterNext(&sIter))!=0 ){

  77079.     int opcode = pOp->opcode;

  77080.     if( opcode==OP_Destroy || opcode==OP_VUpdate || opcode==OP_VRename 

  77081.      || opcode==OP_VDestroy

  77082.      || (opcode==OP_Function0 && pOp->p4.pFunc->funcFlags&SQLITE_FUNC_INTERNAL)

  77083.      || ((opcode==OP_Halt || opcode==OP_HaltIfNull) 

  77084.       && ((pOp->p1)!=SQLITE_OK && pOp->p2==OE_Abort))

  77085.     ){

  77086.       hasAbort = 1;

  77087.       break;

  77088.     }

  77089.     if( opcode==OP_CreateBtree && pOp->p3==BTREE_INTKEY ) hasCreateTable = 1;

  77090.     if( mayAbort ){

  77091.       /* hasCreateIndex may also be set for some DELETE statements that use

  77092.       ** OP_Clear. So this routine may end up returning true in the case 

  77093.       ** where a "DELETE FROM tbl" has a statement-journal but does not

  77094.       ** require one. This is not so bad - it is an inefficiency, not a bug. */

  77095.       if( opcode==OP_CreateBtree && pOp->p3==BTREE_BLOBKEY ) hasCreateIndex = 1;

  77096.       if( opcode==OP_Clear ) hasCreateIndex = 1;

  77097.     }

  77098.     if( opcode==OP_InitCoroutine ) hasInitCoroutine = 1;

  77099. #ifndef SQLITE_OMIT_FOREIGN_KEY

  77100.     if( opcode==OP_FkCounter && pOp->p1==0 && pOp->p2==1 ){

  77101.       hasFkCounter = 1;

  77102.     }

  77103. #endif

  77104.   }

  77105.   sqlite3DbFree(v->db, sIter.apSub);

  77106. 

  77107.   /* Return true if hasAbort==mayAbort. Or if a malloc failure occurred.

  77108.   ** If malloc failed, then the while() loop above may not have iterated

  77109.   ** through all opcodes and hasAbort may be set incorrectly. Return

  77110.   ** true for this case to prevent the assert() in the callers frame

  77111.   ** from failing.  */

  77112.   return ( v->db->mallocFailed || hasAbort==mayAbort || hasFkCounter

  77113.         || (hasCreateTable && hasInitCoroutine) || hasCreateIndex

  77114.   );

  77115. }

  77116. #endif /* SQLITE_DEBUG - the sqlite3AssertMayAbort() function */

  77117. 

  77118. #ifdef SQLITE_DEBUG

  77119. /*

  77120. ** Increment the nWrite counter in the VDBE if the cursor is not an

  77121. ** ephemeral cursor, or if the cursor argument is NULL.

  77122. */

  77123. SQLITE_PRIVATE void sqlite3VdbeIncrWriteCounter(Vdbe *p, VdbeCursor *pC){

  77124.   if( pC==0

  77125.    || (pC->eCurType!=CURTYPE_SORTER

  77126.        && pC->eCurType!=CURTYPE_PSEUDO

  77127.        && !pC->isEphemeral)

  77128.   ){

  77129.     p->nWrite++;

  77130.   }

  77131. }

  77132. #endif

  77133. 

  77134. #ifdef SQLITE_DEBUG

  77135. /*

  77136. ** Assert if an Abort at this point in time might result in a corrupt

  77137. ** database.

  77138. */

  77139. SQLITE_PRIVATE void sqlite3VdbeAssertAbortable(Vdbe *p){

  77140.   assert( p->nWrite==0 || p->usesStmtJournal );

  77141. }

  77142. #endif

  77143. 

  77144. /*

  77145. ** This routine is called after all opcodes have been inserted.  It loops

  77146. ** through all the opcodes and fixes up some details.

  77147. **

  77148. ** (1) For each jump instruction with a negative P2 value (a label)

  77149. **     resolve the P2 value to an actual address.

  77150. **

  77151. ** (2) Compute the maximum number of arguments used by any SQL function

  77152. **     and store that value in *pMaxFuncArgs.

  77153. **

  77154. ** (3) Update the Vdbe.readOnly and Vdbe.bIsReader flags to accurately

  77155. **     indicate what the prepared statement actually does.

  77156. **

  77157. ** (4) Initialize the p4.xAdvance pointer on opcodes that use it.

  77158. **

  77159. ** (5) Reclaim the memory allocated for storing labels.

  77160. **

  77161. ** This routine will only function correctly if the mkopcodeh.tcl generator

  77162. ** script numbers the opcodes correctly.  Changes to this routine must be

  77163. ** coordinated with changes to mkopcodeh.tcl.

  77164. */

  77165. static void resolveP2Values(Vdbe *p, int *pMaxFuncArgs){

  77166.   int nMaxArgs = *pMaxFuncArgs;

  77167.   Op *pOp;

  77168.   Parse *pParse = p->pParse;

  77169.   int *aLabel = pParse->aLabel;

  77170.   p->readOnly = 1;

  77171.   p->bIsReader = 0;

  77172.   pOp = &p->aOp[p->nOp-1];

  77173.   while(1){

  77174. 

  77175.     /* Only JUMP opcodes and the short list of special opcodes in the switch

  77176.     ** below need to be considered.  The mkopcodeh.tcl generator script groups

  77177.     ** all these opcodes together near the front of the opcode list.  Skip

  77178.     ** any opcode that does not need processing by virtual of the fact that

  77179.     ** it is larger than SQLITE_MX_JUMP_OPCODE, as a performance optimization.

  77180.     */

  77181.     if( pOp->opcode<=SQLITE_MX_JUMP_OPCODE ){

  77182.       /* NOTE: Be sure to update mkopcodeh.tcl when adding or removing

  77183.       ** cases from this switch! */

  77184.       switch( pOp->opcode ){

  77185.         case OP_Transaction: {

  77186.           if( pOp->p2!=0 ) p->readOnly = 0;

  77187.           /* fall thru */

  77188.         }

  77189.         case OP_AutoCommit:

  77190.         case OP_Savepoint: {

  77191.           p->bIsReader = 1;

  77192.           break;

  77193.         }

  77194. #ifndef SQLITE_OMIT_WAL

  77195.         case OP_Checkpoint:

  77196. #endif

  77197.         case OP_Vacuum:

  77198.         case OP_JournalMode: {

  77199.           p->readOnly = 0;

  77200.           p->bIsReader = 1;

  77201.           break;

  77202.         }

  77203.         case OP_Next:

  77204.         case OP_SorterNext: {

  77205.           pOp->p4.xAdvance = sqlite3BtreeNext;

  77206.           pOp->p4type = P4_ADVANCE;

  77207.           /* The code generator never codes any of these opcodes as a jump

  77208.           ** to a label.  They are always coded as a jump backwards to a 

  77209.           ** known address */

  77210.           assert( pOp->p2>=0 );

  77211.           break;

  77212.         }

  77213.         case OP_Prev: {

  77214.           pOp->p4.xAdvance = sqlite3BtreePrevious;

  77215.           pOp->p4type = P4_ADVANCE;

  77216.           /* The code generator never codes any of these opcodes as a jump

  77217.           ** to a label.  They are always coded as a jump backwards to a 

  77218.           ** known address */

  77219.           assert( pOp->p2>=0 );

  77220.           break;

  77221.         }

  77222. #ifndef SQLITE_OMIT_VIRTUALTABLE

  77223.         case OP_VUpdate: {

  77224.           if( pOp->p2>nMaxArgs ) nMaxArgs = pOp->p2;

  77225.           break;

  77226.         }

  77227.         case OP_VFilter: {

  77228.           int n;

  77229.           assert( (pOp - p->aOp) >= 3 );

  77230.           assert( pOp[-1].opcode==OP_Integer );

  77231.           n = pOp[-1].p1;

  77232.           if( n>nMaxArgs ) nMaxArgs = n;

  77233.           /* Fall through into the default case */

  77234.         }

  77235. #endif

  77236.         default: {

  77237.           if( pOp->p2<0 ){

  77238.             /* The mkopcodeh.tcl script has so arranged things that the only

  77239.             ** non-jump opcodes less than SQLITE_MX_JUMP_CODE are guaranteed to

  77240.             ** have non-negative values for P2. */

  77241.             assert( (sqlite3OpcodeProperty[pOp->opcode] & OPFLG_JUMP)!=0 );

  77242.             assert( ADDR(pOp->p2)<-pParse->nLabel );

  77243.             pOp->p2 = aLabel[ADDR(pOp->p2)];

  77244.           }

  77245.           break;

  77246.         }

  77247.       }

  77248.       /* The mkopcodeh.tcl script has so arranged things that the only

  77249.       ** non-jump opcodes less than SQLITE_MX_JUMP_CODE are guaranteed to

  77250.       ** have non-negative values for P2. */

  77251.       assert( (sqlite3OpcodeProperty[pOp->opcode]&OPFLG_JUMP)==0 || pOp->p2>=0);

  77252.     }

  77253.     if( pOp==p->aOp ) break;

  77254.     pOp--;

  77255.   }

  77256.   sqlite3DbFree(p->db, pParse->aLabel);

  77257.   pParse->aLabel = 0;

  77258.   pParse->nLabel = 0;

  77259.   *pMaxFuncArgs = nMaxArgs;

  77260.   assert( p->bIsReader!=0 || DbMaskAllZero(p->btreeMask) );

  77261. }

  77262. 

  77263. /*

  77264. ** Return the address of the next instruction to be inserted.

  77265. */

  77266. SQLITE_PRIVATE int sqlite3VdbeCurrentAddr(Vdbe *p){

  77267.   assert( p->magic==VDBE_MAGIC_INIT );

  77268.   return p->nOp;

  77269. }

  77270. 

  77271. /*

  77272. ** Verify that at least N opcode slots are available in p without

  77273. ** having to malloc for more space (except when compiled using

  77274. ** SQLITE_TEST_REALLOC_STRESS).  This interface is used during testing

  77275. ** to verify that certain calls to sqlite3VdbeAddOpList() can never

  77276. ** fail due to a OOM fault and hence that the return value from

  77277. ** sqlite3VdbeAddOpList() will always be non-NULL.

  77278. */

  77279. #if defined(SQLITE_DEBUG) && !defined(SQLITE_TEST_REALLOC_STRESS)

  77280. SQLITE_PRIVATE void sqlite3VdbeVerifyNoMallocRequired(Vdbe *p, int N){

  77281.   assert( p->nOp + N <= p->nOpAlloc );

  77282. }

  77283. #endif

  77284. 

  77285. /*

  77286. ** Verify that the VM passed as the only argument does not contain

  77287. ** an OP_ResultRow opcode. Fail an assert() if it does. This is used

  77288. ** by code in pragma.c to ensure that the implementation of certain

  77289. ** pragmas comports with the flags specified in the mkpragmatab.tcl

  77290. ** script.

  77291. */

  77292. #if defined(SQLITE_DEBUG) && !defined(SQLITE_TEST_REALLOC_STRESS)

  77293. SQLITE_PRIVATE void sqlite3VdbeVerifyNoResultRow(Vdbe *p){

  77294.   int i;

  77295.   for(i=0; i<p->nOp; i++){

  77296.     assert( p->aOp[i].opcode!=OP_ResultRow );

  77297.   }

  77298. }

  77299. #endif

  77300. 

  77301. /*

  77302. ** Generate code (a single OP_Abortable opcode) that will

  77303. ** verify that the VDBE program can safely call Abort in the current

  77304. ** context.

  77305. */

  77306. #if defined(SQLITE_DEBUG)

  77307. SQLITE_PRIVATE void sqlite3VdbeVerifyAbortable(Vdbe *p, int onError){

  77308.   if( onError==OE_Abort ) sqlite3VdbeAddOp0(p, OP_Abortable);

  77309. }

  77310. #endif

  77311. 

  77312. /*

  77313. ** This function returns a pointer to the array of opcodes associated with

  77314. ** the Vdbe passed as the first argument. It is the callers responsibility

  77315. ** to arrange for the returned array to be eventually freed using the 

  77316. ** vdbeFreeOpArray() function.

  77317. **

  77318. ** Before returning, *pnOp is set to the number of entries in the returned

  77319. ** array. Also, *pnMaxArg is set to the larger of its current value and 

  77320. ** the number of entries in the Vdbe.apArg[] array required to execute the 

  77321. ** returned program.

  77322. */

  77323. SQLITE_PRIVATE VdbeOp *sqlite3VdbeTakeOpArray(Vdbe *p, int *pnOp, int *pnMaxArg){

  77324.   VdbeOp *aOp = p->aOp;

  77325.   assert( aOp && !p->db->mallocFailed );

  77326. 

  77327.   /* Check that sqlite3VdbeUsesBtree() was not called on this VM */

  77328.   assert( DbMaskAllZero(p->btreeMask) );

  77329. 

  77330.   resolveP2Values(p, pnMaxArg);

  77331.   *pnOp = p->nOp;

  77332.   p->aOp = 0;

  77333.   return aOp;

  77334. }

  77335. 

  77336. /*

  77337. ** Add a whole list of operations to the operation stack.  Return a

  77338. ** pointer to the first operation inserted.

  77339. **

  77340. ** Non-zero P2 arguments to jump instructions are automatically adjusted

  77341. ** so that the jump target is relative to the first operation inserted.

  77342. */

  77343. SQLITE_PRIVATE VdbeOp *sqlite3VdbeAddOpList(

  77344.   Vdbe *p,                     /* Add opcodes to the prepared statement */

  77345.   int nOp,                     /* Number of opcodes to add */

  77346.   VdbeOpList const *aOp,       /* The opcodes to be added */

  77347.   int iLineno                  /* Source-file line number of first opcode */

  77348. ){

  77349.   int i;

  77350.   VdbeOp *pOut, *pFirst;

  77351.   assert( nOp>0 );

  77352.   assert( p->magic==VDBE_MAGIC_INIT );

  77353.   if( p->nOp + nOp > p->nOpAlloc && growOpArray(p, nOp) ){

  77354.     return 0;

  77355.   }

  77356.   pFirst = pOut = &p->aOp[p->nOp];

  77357.   for(i=0; i<nOp; i++, aOp++, pOut++){

  77358.     pOut->opcode = aOp->opcode;

  77359.     pOut->p1 = aOp->p1;

  77360.     pOut->p2 = aOp->p2;

  77361.     assert( aOp->p2>=0 );

  77362.     if( (sqlite3OpcodeProperty[aOp->opcode] & OPFLG_JUMP)!=0 && aOp->p2>0 ){

  77363.       pOut->p2 += p->nOp;

  77364.     }

  77365.     pOut->p3 = aOp->p3;

  77366.     pOut->p4type = P4_NOTUSED;

  77367.     pOut->p4.p = 0;

  77368.     pOut->p5 = 0;

  77369. #ifdef SQLITE_ENABLE_EXPLAIN_COMMENTS

  77370.     pOut->zComment = 0;

  77371. #endif

  77372. #ifdef SQLITE_VDBE_COVERAGE

  77373.     pOut->iSrcLine = iLineno+i;

  77374. #else

  77375.     (void)iLineno;

  77376. #endif

  77377. #ifdef SQLITE_DEBUG

  77378.     if( p->db->flags & SQLITE_VdbeAddopTrace ){

  77379.       sqlite3VdbePrintOp(0, i+p->nOp, &p->aOp[i+p->nOp]);

  77380.     }

  77381. #endif

  77382.   }

  77383.   p->nOp += nOp;

  77384.   return pFirst;

  77385. }

  77386. 

  77387. #if defined(SQLITE_ENABLE_STMT_SCANSTATUS)

  77388. /*

  77389. ** Add an entry to the array of counters managed by sqlite3_stmt_scanstatus().

  77390. */

  77391. SQLITE_PRIVATE void sqlite3VdbeScanStatus(

  77392.   Vdbe *p,                        /* VM to add scanstatus() to */

  77393.   int addrExplain,                /* Address of OP_Explain (or 0) */

  77394.   int addrLoop,                   /* Address of loop counter */ 

  77395.   int addrVisit,                  /* Address of rows visited counter */

  77396.   LogEst nEst,                    /* Estimated number of output rows */

  77397.   const char *zName               /* Name of table or index being scanned */

  77398. ){

  77399.   sqlite3_int64 nByte = (p->nScan+1) * sizeof(ScanStatus);

  77400.   ScanStatus *aNew;

  77401.   aNew = (ScanStatus*)sqlite3DbRealloc(p->db, p->aScan, nByte);

  77402.   if( aNew ){

  77403.     ScanStatus *pNew = &aNew[p->nScan++];

  77404.     pNew->addrExplain = addrExplain;

  77405.     pNew->addrLoop = addrLoop;

  77406.     pNew->addrVisit = addrVisit;

  77407.     pNew->nEst = nEst;

  77408.     pNew->zName = sqlite3DbStrDup(p->db, zName);

  77409.     p->aScan = aNew;

  77410.   }

  77411. }

  77412. #endif

  77413. 

  77414. 

  77415. /*

  77416. ** Change the value of the opcode, or P1, P2, P3, or P5 operands

  77417. ** for a specific instruction.

  77418. */

  77419. SQLITE_PRIVATE void sqlite3VdbeChangeOpcode(Vdbe *p, u32 addr, u8 iNewOpcode){

  77420.   sqlite3VdbeGetOp(p,addr)->opcode = iNewOpcode;

  77421. }

  77422. SQLITE_PRIVATE void sqlite3VdbeChangeP1(Vdbe *p, u32 addr, int val){

  77423.   sqlite3VdbeGetOp(p,addr)->p1 = val;

  77424. }

  77425. SQLITE_PRIVATE void sqlite3VdbeChangeP2(Vdbe *p, u32 addr, int val){

  77426.   sqlite3VdbeGetOp(p,addr)->p2 = val;

  77427. }

  77428. SQLITE_PRIVATE void sqlite3VdbeChangeP3(Vdbe *p, u32 addr, int val){

  77429.   sqlite3VdbeGetOp(p,addr)->p3 = val;

  77430. }

  77431. SQLITE_PRIVATE void sqlite3VdbeChangeP5(Vdbe *p, u16 p5){

  77432.   assert( p->nOp>0 || p->db->mallocFailed );

  77433.   if( p->nOp>0 ) p->aOp[p->nOp-1].p5 = p5;

  77434. }

  77435. 

  77436. /*

  77437. ** Change the P2 operand of instruction addr so that it points to

  77438. ** the address of the next instruction to be coded.

  77439. */

  77440. SQLITE_PRIVATE void sqlite3VdbeJumpHere(Vdbe *p, int addr){

  77441.   sqlite3VdbeChangeP2(p, addr, p->nOp);

  77442. }

  77443. 

  77444. 

  77445. /*

  77446. ** If the input FuncDef structure is ephemeral, then free it.  If

  77447. ** the FuncDef is not ephermal, then do nothing.

  77448. */

  77449. static void freeEphemeralFunction(sqlite3 *db, FuncDef *pDef){

  77450.   if( (pDef->funcFlags & SQLITE_FUNC_EPHEM)!=0 ){

  77451.     sqlite3DbFreeNN(db, pDef);

  77452.   }

  77453. }

  77454. 

  77455. static void vdbeFreeOpArray(sqlite3 *, Op *, int);

  77456. 

  77457. /*

  77458. ** Delete a P4 value if necessary.

  77459. */

  77460. static SQLITE_NOINLINE void freeP4Mem(sqlite3 *db, Mem *p){

  77461.   if( p->szMalloc ) sqlite3DbFree(db, p->zMalloc);

  77462.   sqlite3DbFreeNN(db, p);

  77463. }

  77464. static SQLITE_NOINLINE void freeP4FuncCtx(sqlite3 *db, sqlite3_context *p){

  77465.   freeEphemeralFunction(db, p->pFunc);

  77466.  sqlite3DbFreeNN(db, p);

  77467. }

  77468. static void freeP4(sqlite3 *db, int p4type, void *p4){

  77469.   assert( db );

  77470.   switch( p4type ){

  77471.     case P4_FUNCCTX: {

  77472.       freeP4FuncCtx(db, (sqlite3_context*)p4);

  77473.       break;

  77474.     }

  77475.     case P4_REAL:

  77476.     case P4_INT64:

  77477.     case P4_DYNAMIC:

  77478.     case P4_DYNBLOB:

  77479.     case P4_INTARRAY: {

  77480.       sqlite3DbFree(db, p4);

  77481.       break;

  77482.     }

  77483.     case P4_KEYINFO: {

  77484.       if( db->pnBytesFreed==0 ) sqlite3KeyInfoUnref((KeyInfo*)p4);

  77485.       break;

  77486.     }

  77487. #ifdef SQLITE_ENABLE_CURSOR_HINTS

  77488.     case P4_EXPR: {

  77489.       sqlite3ExprDelete(db, (Expr*)p4);

  77490.       break;

  77491.     }

  77492. #endif

  77493.     case P4_FUNCDEF: {

  77494.       freeEphemeralFunction(db, (FuncDef*)p4);

  77495.       break;

  77496.     }

  77497.     case P4_MEM: {

  77498.       if( db->pnBytesFreed==0 ){

  77499.         sqlite3ValueFree((sqlite3_value*)p4);

  77500.       }else{

  77501.         freeP4Mem(db, (Mem*)p4);

  77502.       }

  77503.       break;

  77504.     }

  77505.     case P4_VTAB : {

  77506.       if( db->pnBytesFreed==0 ) sqlite3VtabUnlock((VTable *)p4);

  77507.       break;

  77508.     }

  77509.   }

  77510. }

  77511. 

  77512. /*

  77513. ** Free the space allocated for aOp and any p4 values allocated for the

  77514. ** opcodes contained within. If aOp is not NULL it is assumed to contain 

  77515. ** nOp entries. 

  77516. */

  77517. static void vdbeFreeOpArray(sqlite3 *db, Op *aOp, int nOp){

  77518.   if( aOp ){

  77519.     Op *pOp;

  77520.     for(pOp=&aOp[nOp-1]; pOp>=aOp; pOp--){

  77521.       if( pOp->p4type <= P4_FREE_IF_LE ) freeP4(db, pOp->p4type, pOp->p4.p);

  77522. #ifdef SQLITE_ENABLE_EXPLAIN_COMMENTS

  77523.       sqlite3DbFree(db, pOp->zComment);

  77524. #endif     

  77525.     }

  77526.     sqlite3DbFreeNN(db, aOp);

  77527.   }

  77528. }

  77529. 

  77530. /*

  77531. ** Link the SubProgram object passed as the second argument into the linked

  77532. ** list at Vdbe.pSubProgram. This list is used to delete all sub-program

  77533. ** objects when the VM is no longer required.

  77534. */

  77535. SQLITE_PRIVATE void sqlite3VdbeLinkSubProgram(Vdbe *pVdbe, SubProgram *p){

  77536.   p->pNext = pVdbe->pProgram;

  77537.   pVdbe->pProgram = p;

  77538. }

  77539. 

  77540. /*

  77541. ** Change the opcode at addr into OP_Noop

  77542. */

  77543. SQLITE_PRIVATE int sqlite3VdbeChangeToNoop(Vdbe *p, int addr){

  77544.   VdbeOp *pOp;

  77545.   if( p->db->mallocFailed ) return 0;

  77546.   assert( addr>=0 && addr<p->nOp );

  77547.   pOp = &p->aOp[addr];

  77548.   freeP4(p->db, pOp->p4type, pOp->p4.p);

  77549.   pOp->p4type = P4_NOTUSED;

  77550.   pOp->p4.z = 0;

  77551.   pOp->opcode = OP_Noop;

  77552.   return 1;

  77553. }

  77554. 

  77555. /*

  77556. ** If the last opcode is "op" and it is not a jump destination,

  77557. ** then remove it.  Return true if and only if an opcode was removed.

  77558. */

  77559. SQLITE_PRIVATE int sqlite3VdbeDeletePriorOpcode(Vdbe *p, u8 op){

  77560.   if( p->nOp>0 && p->aOp[p->nOp-1].opcode==op ){

  77561.     return sqlite3VdbeChangeToNoop(p, p->nOp-1);

  77562.   }else{

  77563.     return 0;

  77564.   }

  77565. }

  77566. 

  77567. /*

  77568. ** Change the value of the P4 operand for a specific instruction.

  77569. ** This routine is useful when a large program is loaded from a

  77570. ** static array using sqlite3VdbeAddOpList but we want to make a

  77571. ** few minor changes to the program.

  77572. **

  77573. ** If n>=0 then the P4 operand is dynamic, meaning that a copy of

  77574. ** the string is made into memory obtained from sqlite3_malloc().

  77575. ** A value of n==0 means copy bytes of zP4 up to and including the

  77576. ** first null byte.  If n>0 then copy n+1 bytes of zP4.

  77577. ** 

  77578. ** Other values of n (P4_STATIC, P4_COLLSEQ etc.) indicate that zP4 points

  77579. ** to a string or structure that is guaranteed to exist for the lifetime of

  77580. ** the Vdbe. In these cases we can just copy the pointer.

  77581. **

  77582. ** If addr<0 then change P4 on the most recently inserted instruction.

  77583. */

  77584. static void SQLITE_NOINLINE vdbeChangeP4Full(

  77585.   Vdbe *p,

  77586.   Op *pOp,

  77587.   const char *zP4,

  77588.   int n

  77589. ){

  77590.   if( pOp->p4type ){

  77591.     freeP4(p->db, pOp->p4type, pOp->p4.p);

  77592.     pOp->p4type = 0;

  77593.     pOp->p4.p = 0;

  77594.   }

  77595.   if( n<0 ){

  77596.     sqlite3VdbeChangeP4(p, (int)(pOp - p->aOp), zP4, n);

  77597.   }else{

  77598.     if( n==0 ) n = sqlite3Strlen30(zP4);

  77599.     pOp->p4.z = sqlite3DbStrNDup(p->db, zP4, n);

  77600.     pOp->p4type = P4_DYNAMIC;

  77601.   }

  77602. }

  77603. SQLITE_PRIVATE void sqlite3VdbeChangeP4(Vdbe *p, int addr, const char *zP4, int n){

  77604.   Op *pOp;

  77605.   sqlite3 *db;

  77606.   assert( p!=0 );

  77607.   db = p->db;

  77608.   assert( p->magic==VDBE_MAGIC_INIT );

  77609.   assert( p->aOp!=0 || db->mallocFailed );

  77610.   if( db->mallocFailed ){

  77611.     if( n!=P4_VTAB ) freeP4(db, n, (void*)*(char**)&zP4);

  77612.     return;

  77613.   }

  77614.   assert( p->nOp>0 );

  77615.   assert( addr<p->nOp );

  77616.   if( addr<0 ){

  77617.     addr = p->nOp - 1;

  77618.   }

  77619.   pOp = &p->aOp[addr];

  77620.   if( n>=0 || pOp->p4type ){

  77621.     vdbeChangeP4Full(p, pOp, zP4, n);

  77622.     return;

  77623.   }

  77624.   if( n==P4_INT32 ){

  77625.     /* Note: this cast is safe, because the origin data point was an int

  77626.     ** that was cast to a (const char *). */

  77627.     pOp->p4.i = SQLITE_PTR_TO_INT(zP4);

  77628.     pOp->p4type = P4_INT32;

  77629.   }else if( zP4!=0 ){

  77630.     assert( n<0 );

  77631.     pOp->p4.p = (void*)zP4;

  77632.     pOp->p4type = (signed char)n;

  77633.     if( n==P4_VTAB ) sqlite3VtabLock((VTable*)zP4);

  77634.   }

  77635. }

  77636. 

  77637. /*

  77638. ** Change the P4 operand of the most recently coded instruction 

  77639. ** to the value defined by the arguments.  This is a high-speed

  77640. ** version of sqlite3VdbeChangeP4().

  77641. **

  77642. ** The P4 operand must not have been previously defined.  And the new

  77643. ** P4 must not be P4_INT32.  Use sqlite3VdbeChangeP4() in either of

  77644. ** those cases.

  77645. */

  77646. SQLITE_PRIVATE void sqlite3VdbeAppendP4(Vdbe *p, void *pP4, int n){

  77647.   VdbeOp *pOp;

  77648.   assert( n!=P4_INT32 && n!=P4_VTAB );

  77649.   assert( n<=0 );

  77650.   if( p->db->mallocFailed ){

  77651.     freeP4(p->db, n, pP4);

  77652.   }else{

  77653.     assert( pP4!=0 );

  77654.     assert( p->nOp>0 );

  77655.     pOp = &p->aOp[p->nOp-1];

  77656.     assert( pOp->p4type==P4_NOTUSED );

  77657.     pOp->p4type = n;

  77658.     pOp->p4.p = pP4;

  77659.   }

  77660. }

  77661. 

  77662. /*

  77663. ** Set the P4 on the most recently added opcode to the KeyInfo for the

  77664. ** index given.

  77665. */

  77666. SQLITE_PRIVATE void sqlite3VdbeSetP4KeyInfo(Parse *pParse, Index *pIdx){

  77667.   Vdbe *v = pParse->pVdbe;

  77668.   KeyInfo *pKeyInfo;

  77669.   assert( v!=0 );

  77670.   assert( pIdx!=0 );

  77671.   pKeyInfo = sqlite3KeyInfoOfIndex(pParse, pIdx);

  77672.   if( pKeyInfo ) sqlite3VdbeAppendP4(v, pKeyInfo, P4_KEYINFO);

  77673. }

  77674. 

  77675. #ifdef SQLITE_ENABLE_EXPLAIN_COMMENTS

  77676. /*

  77677. ** Change the comment on the most recently coded instruction.  Or

  77678. ** insert a No-op and add the comment to that new instruction.  This

  77679. ** makes the code easier to read during debugging.  None of this happens

  77680. ** in a production build.

  77681. */

  77682. static void vdbeVComment(Vdbe *p, const char *zFormat, va_list ap){

  77683.   assert( p->nOp>0 || p->aOp==0 );

  77684.   assert( p->aOp==0 || p->aOp[p->nOp-1].zComment==0 || p->db->mallocFailed );

  77685.   if( p->nOp ){

  77686.     assert( p->aOp );

  77687.     sqlite3DbFree(p->db, p->aOp[p->nOp-1].zComment);

  77688.     p->aOp[p->nOp-1].zComment = sqlite3VMPrintf(p->db, zFormat, ap);

  77689.   }

  77690. }

  77691. SQLITE_PRIVATE void sqlite3VdbeComment(Vdbe *p, const char *zFormat, ...){

  77692.   va_list ap;

  77693.   if( p ){

  77694.     va_start(ap, zFormat);

  77695.     vdbeVComment(p, zFormat, ap);

  77696.     va_end(ap);

  77697.   }

  77698. }

  77699. SQLITE_PRIVATE void sqlite3VdbeNoopComment(Vdbe *p, const char *zFormat, ...){

  77700.   va_list ap;

  77701.   if( p ){

  77702.     sqlite3VdbeAddOp0(p, OP_Noop);

  77703.     va_start(ap, zFormat);

  77704.     vdbeVComment(p, zFormat, ap);

  77705.     va_end(ap);

  77706.   }

  77707. }

  77708. #endif  /* NDEBUG */

  77709. 

  77710. #ifdef SQLITE_VDBE_COVERAGE

  77711. /*

  77712. ** Set the value if the iSrcLine field for the previously coded instruction.

  77713. */

  77714. SQLITE_PRIVATE void sqlite3VdbeSetLineNumber(Vdbe *v, int iLine){

  77715.   sqlite3VdbeGetOp(v,-1)->iSrcLine = iLine;

  77716. }

  77717. #endif /* SQLITE_VDBE_COVERAGE */

  77718. 

  77719. /*

  77720. ** Return the opcode for a given address.  If the address is -1, then

  77721. ** return the most recently inserted opcode.

  77722. **

  77723. ** If a memory allocation error has occurred prior to the calling of this

  77724. ** routine, then a pointer to a dummy VdbeOp will be returned.  That opcode

  77725. ** is readable but not writable, though it is cast to a writable value.

  77726. ** The return of a dummy opcode allows the call to continue functioning

  77727. ** after an OOM fault without having to check to see if the return from 

  77728. ** this routine is a valid pointer.  But because the dummy.opcode is 0,

  77729. ** dummy will never be written to.  This is verified by code inspection and

  77730. ** by running with Valgrind.

  77731. */

  77732. SQLITE_PRIVATE VdbeOp *sqlite3VdbeGetOp(Vdbe *p, int addr){

  77733.   /* C89 specifies that the constant "dummy" will be initialized to all

  77734.   ** zeros, which is correct.  MSVC generates a warning, nevertheless. */

  77735.   static VdbeOp dummy;  /* Ignore the MSVC warning about no initializer */

  77736.   assert( p->magic==VDBE_MAGIC_INIT );

  77737.   if( addr<0 ){

  77738.     addr = p->nOp - 1;

  77739.   }

  77740.   assert( (addr>=0 && addr<p->nOp) || p->db->mallocFailed );

  77741.   if( p->db->mallocFailed ){

  77742.     return (VdbeOp*)&dummy;

  77743.   }else{

  77744.     return &p->aOp[addr];

  77745.   }

  77746. }

  77747. 

  77748. #if defined(SQLITE_ENABLE_EXPLAIN_COMMENTS)

  77749. /*

  77750. ** Return an integer value for one of the parameters to the opcode pOp

  77751. ** determined by character c.

  77752. */

  77753. static int translateP(char c, const Op *pOp){

  77754.   if( c=='1' ) return pOp->p1;

  77755.   if( c=='2' ) return pOp->p2;

  77756.   if( c=='3' ) return pOp->p3;

  77757.   if( c=='4' ) return pOp->p4.i;

  77758.   return pOp->p5;

  77759. }

  77760. 

  77761. /*

  77762. ** Compute a string for the "comment" field of a VDBE opcode listing.

  77763. **

  77764. ** The Synopsis: field in comments in the vdbe.c source file gets converted

  77765. ** to an extra string that is appended to the sqlite3OpcodeName().  In the

  77766. ** absence of other comments, this synopsis becomes the comment on the opcode.

  77767. ** Some translation occurs:

  77768. **

  77769. **       "PX"      ->  "r[X]"

  77770. **       "PX@PY"   ->  "r[X..X+Y-1]"  or "r[x]" if y is 0 or 1

  77771. **       "PX@PY+1" ->  "r[X..X+Y]"    or "r[x]" if y is 0

  77772. **       "PY..PY"  ->  "r[X..Y]"      or "r[x]" if y<=x

  77773. */

  77774. static int displayComment(

  77775.   const Op *pOp,     /* The opcode to be commented */

  77776.   const char *zP4,   /* Previously obtained value for P4 */

  77777.   char *zTemp,       /* Write result here */

  77778.   int nTemp          /* Space available in zTemp[] */

  77779. ){

  77780.   const char *zOpName;

  77781.   const char *zSynopsis;

  77782.   int nOpName;

  77783.   int ii, jj;

  77784.   char zAlt[50];

  77785.   zOpName = sqlite3OpcodeName(pOp->opcode);

  77786.   nOpName = sqlite3Strlen30(zOpName);

  77787.   if( zOpName[nOpName+1] ){

  77788.     int seenCom = 0;

  77789.     char c;

  77790.     zSynopsis = zOpName += nOpName + 1;

  77791.     if( strncmp(zSynopsis,"IF ",3)==0 ){

  77792.       if( pOp->p5 & SQLITE_STOREP2 ){

  77793.         sqlite3_snprintf(sizeof(zAlt), zAlt, "r[P2] = (%s)", zSynopsis+3);

  77794.       }else{

  77795.         sqlite3_snprintf(sizeof(zAlt), zAlt, "if %s goto P2", zSynopsis+3);

  77796.       }

  77797.       zSynopsis = zAlt;

  77798.     }

  77799.     for(ii=jj=0; jj<nTemp-1 && (c = zSynopsis[ii])!=0; ii++){

  77800.       if( c=='P' ){

  77801.         c = zSynopsis[++ii];

  77802.         if( c=='4' ){

  77803.           sqlite3_snprintf(nTemp-jj, zTemp+jj, "%s", zP4);

  77804.         }else if( c=='X' ){

  77805.           sqlite3_snprintf(nTemp-jj, zTemp+jj, "%s", pOp->zComment);

  77806.           seenCom = 1;

  77807.         }else{

  77808.           int v1 = translateP(c, pOp);

  77809.           int v2;

  77810.           sqlite3_snprintf(nTemp-jj, zTemp+jj, "%d", v1);

  77811.           if( strncmp(zSynopsis+ii+1, "@P", 2)==0 ){

  77812.             ii += 3;

  77813.             jj += sqlite3Strlen30(zTemp+jj);

  77814.             v2 = translateP(zSynopsis[ii], pOp);

  77815.             if( strncmp(zSynopsis+ii+1,"+1",2)==0 ){

  77816.               ii += 2;

  77817.               v2++;

  77818.             }

  77819.             if( v2>1 ){

  77820.               sqlite3_snprintf(nTemp-jj, zTemp+jj, "..%d", v1+v2-1);

  77821.             }

  77822.           }else if( strncmp(zSynopsis+ii+1, "..P3", 4)==0 && pOp->p3==0 ){

  77823.             ii += 4;

  77824.           }

  77825.         }

  77826.         jj += sqlite3Strlen30(zTemp+jj);

  77827.       }else{

  77828.         zTemp[jj++] = c;

  77829.       }

  77830.     }

  77831.     if( !seenCom && jj<nTemp-5 && pOp->zComment ){

  77832.       sqlite3_snprintf(nTemp-jj, zTemp+jj, "; %s", pOp->zComment);

  77833.       jj += sqlite3Strlen30(zTemp+jj);

  77834.     }

  77835.     if( jj<nTemp ) zTemp[jj] = 0;

  77836.   }else if( pOp->zComment ){

  77837.     sqlite3_snprintf(nTemp, zTemp, "%s", pOp->zComment);

  77838.     jj = sqlite3Strlen30(zTemp);

  77839.   }else{

  77840.     zTemp[0] = 0;

  77841.     jj = 0;

  77842.   }

  77843.   return jj;

  77844. }

  77845. #endif /* SQLITE_DEBUG */

  77846. 

  77847. #if VDBE_DISPLAY_P4 && defined(SQLITE_ENABLE_CURSOR_HINTS)

  77848. /*

  77849. ** Translate the P4.pExpr value for an OP_CursorHint opcode into text

  77850. ** that can be displayed in the P4 column of EXPLAIN output.

  77851. */

  77852. static void displayP4Expr(StrAccum *p, Expr *pExpr){

  77853.   const char *zOp = 0;

  77854.   switch( pExpr->op ){

  77855.     case TK_STRING:

  77856.       sqlite3_str_appendf(p, "%Q", pExpr->u.zToken);

  77857.       break;

  77858.     case TK_INTEGER:

  77859.       sqlite3_str_appendf(p, "%d", pExpr->u.iValue);

  77860.       break;

  77861.     case TK_NULL:

  77862.       sqlite3_str_appendf(p, "NULL");

  77863.       break;

  77864.     case TK_REGISTER: {

  77865.       sqlite3_str_appendf(p, "r[%d]", pExpr->iTable);

  77866.       break;

  77867.     }

  77868.     case TK_COLUMN: {

  77869.       if( pExpr->iColumn<0 ){

  77870.         sqlite3_str_appendf(p, "rowid");

  77871.       }else{

  77872.         sqlite3_str_appendf(p, "c%d", (int)pExpr->iColumn);

  77873.       }

  77874.       break;

  77875.     }

  77876.     case TK_LT:      zOp = "LT";      break;

  77877.     case TK_LE:      zOp = "LE";      break;

  77878.     case TK_GT:      zOp = "GT";      break;

  77879.     case TK_GE:      zOp = "GE";      break;

  77880.     case TK_NE:      zOp = "NE";      break;

  77881.     case TK_EQ:      zOp = "EQ";      break;

  77882.     case TK_IS:      zOp = "IS";      break;

  77883.     case TK_ISNOT:   zOp = "ISNOT";   break;

  77884.     case TK_AND:     zOp = "AND";     break;

  77885.     case TK_OR:      zOp = "OR";      break;

  77886.     case TK_PLUS:    zOp = "ADD";     break;

  77887.     case TK_STAR:    zOp = "MUL";     break;

  77888.     case TK_MINUS:   zOp = "SUB";     break;

  77889.     case TK_REM:     zOp = "REM";     break;

  77890.     case TK_BITAND:  zOp = "BITAND";  break;

  77891.     case TK_BITOR:   zOp = "BITOR";   break;

  77892.     case TK_SLASH:   zOp = "DIV";     break;

  77893.     case TK_LSHIFT:  zOp = "LSHIFT";  break;

  77894.     case TK_RSHIFT:  zOp = "RSHIFT";  break;

  77895.     case TK_CONCAT:  zOp = "CONCAT";  break;

  77896.     case TK_UMINUS:  zOp = "MINUS";   break;

  77897.     case TK_UPLUS:   zOp = "PLUS";    break;

  77898.     case TK_BITNOT:  zOp = "BITNOT";  break;

  77899.     case TK_NOT:     zOp = "NOT";     break;

  77900.     case TK_ISNULL:  zOp = "ISNULL";  break;

  77901.     case TK_NOTNULL: zOp = "NOTNULL"; break;

  77902. 

  77903.     default:

  77904.       sqlite3_str_appendf(p, "%s", "expr");

  77905.       break;

  77906.   }

  77907. 

  77908.   if( zOp ){

  77909.     sqlite3_str_appendf(p, "%s(", zOp);

  77910.     displayP4Expr(p, pExpr->pLeft);

  77911.     if( pExpr->pRight ){

  77912.       sqlite3_str_append(p, ",", 1);

  77913.       displayP4Expr(p, pExpr->pRight);

  77914.     }

  77915.     sqlite3_str_append(p, ")", 1);

  77916.   }

  77917. }

  77918. #endif /* VDBE_DISPLAY_P4 && defined(SQLITE_ENABLE_CURSOR_HINTS) */

  77919. 

  77920. 

  77921. #if VDBE_DISPLAY_P4

  77922. /*

  77923. ** Compute a string that describes the P4 parameter for an opcode.

  77924. ** Use zTemp for any required temporary buffer space.

  77925. */

  77926. static char *displayP4(Op *pOp, char *zTemp, int nTemp){

  77927.   char *zP4 = zTemp;

  77928.   StrAccum x;

  77929.   assert( nTemp>=20 );

  77930.   sqlite3StrAccumInit(&x, 0, zTemp, nTemp, 0);

  77931.   switch( pOp->p4type ){

  77932.     case P4_KEYINFO: {

  77933.       int j;

  77934.       KeyInfo *pKeyInfo = pOp->p4.pKeyInfo;

  77935.       assert( pKeyInfo->aSortOrder!=0 );

  77936.       sqlite3_str_appendf(&x, "k(%d", pKeyInfo->nKeyField);

  77937.       for(j=0; j<pKeyInfo->nKeyField; j++){

  77938.         CollSeq *pColl = pKeyInfo->aColl[j];

  77939.         const char *zColl = pColl ? pColl->zName : "";

  77940.         if( strcmp(zColl, "BINARY")==0 ) zColl = "B";

  77941.         sqlite3_str_appendf(&x, ",%s%s", 

  77942.                pKeyInfo->aSortOrder[j] ? "-" : "", zColl);

  77943.       }

  77944.       sqlite3_str_append(&x, ")", 1);

  77945.       break;

  77946.     }

  77947. #ifdef SQLITE_ENABLE_CURSOR_HINTS

  77948.     case P4_EXPR: {

  77949.       displayP4Expr(&x, pOp->p4.pExpr);

  77950.       break;

  77951.     }

  77952. #endif

  77953.     case P4_COLLSEQ: {

  77954.       CollSeq *pColl = pOp->p4.pColl;

  77955.       sqlite3_str_appendf(&x, "(%.20s)", pColl->zName);

  77956.       break;

  77957.     }

  77958.     case P4_FUNCDEF: {

  77959.       FuncDef *pDef = pOp->p4.pFunc;

  77960.       sqlite3_str_appendf(&x, "%s(%d)", pDef->zName, pDef->nArg);

  77961.       break;

  77962.     }

  77963. #if defined(SQLITE_DEBUG) || defined(VDBE_PROFILE)

  77964.     case P4_FUNCCTX: {

  77965.       FuncDef *pDef = pOp->p4.pCtx->pFunc;

  77966.       sqlite3_str_appendf(&x, "%s(%d)", pDef->zName, pDef->nArg);

  77967.       break;

  77968.     }

  77969. #endif

  77970.     case P4_INT64: {

  77971.       sqlite3_str_appendf(&x, "%lld", *pOp->p4.pI64);

  77972.       break;

  77973.     }

  77974.     case P4_INT32: {

  77975.       sqlite3_str_appendf(&x, "%d", pOp->p4.i);

  77976.       break;

  77977.     }

  77978.     case P4_REAL: {

  77979.       sqlite3_str_appendf(&x, "%.16g", *pOp->p4.pReal);

  77980.       break;

  77981.     }

  77982.     case P4_MEM: {

  77983.       Mem *pMem = pOp->p4.pMem;

  77984.       if( pMem->flags & MEM_Str ){

  77985.         zP4 = pMem->z;

  77986.       }else if( pMem->flags & (MEM_Int|MEM_IntReal) ){

  77987.         sqlite3_str_appendf(&x, "%lld", pMem->u.i);

  77988.       }else if( pMem->flags & MEM_Real ){

  77989.         sqlite3_str_appendf(&x, "%.16g", pMem->u.r);

  77990.       }else if( pMem->flags & MEM_Null ){

  77991.         zP4 = "NULL";

  77992.       }else{

  77993.         assert( pMem->flags & MEM_Blob );

  77994.         zP4 = "(blob)";

  77995.       }

  77996.       break;

  77997.     }

  77998. #ifndef SQLITE_OMIT_VIRTUALTABLE

  77999.     case P4_VTAB: {

  78000.       sqlite3_vtab *pVtab = pOp->p4.pVtab->pVtab;

  78001.       sqlite3_str_appendf(&x, "vtab:%p", pVtab);

  78002.       break;

  78003.     }

  78004. #endif

  78005.     case P4_INTARRAY: {

  78006.       int i;

  78007.       int *ai = pOp->p4.ai;

  78008.       int n = ai[0];   /* The first element of an INTARRAY is always the

  78009.                        ** count of the number of elements to follow */

  78010.       for(i=1; i<=n; i++){

  78011.         sqlite3_str_appendf(&x, ",%d", ai[i]);

  78012.       }

  78013.       zTemp[0] = '[';

  78014.       sqlite3_str_append(&x, "]", 1);

  78015.       break;

  78016.     }

  78017.     case P4_SUBPROGRAM: {

  78018.       sqlite3_str_appendf(&x, "program");

  78019.       break;

  78020.     }

  78021.     case P4_DYNBLOB:

  78022.     case P4_ADVANCE: {

  78023.       zTemp[0] = 0;

  78024.       break;

  78025.     }

  78026.     case P4_TABLE: {

  78027.       sqlite3_str_appendf(&x, "%s", pOp->p4.pTab->zName);

  78028.       break;

  78029.     }

  78030.     default: {

  78031.       zP4 = pOp->p4.z;

  78032.       if( zP4==0 ){

  78033.         zP4 = zTemp;

  78034.         zTemp[0] = 0;

  78035.       }

  78036.     }

  78037.   }

  78038.   sqlite3StrAccumFinish(&x);

  78039.   assert( zP4!=0 );

  78040.   return zP4;

  78041. }

  78042. #endif /* VDBE_DISPLAY_P4 */

  78043. 

  78044. /*

  78045. ** Declare to the Vdbe that the BTree object at db->aDb[i] is used.

  78046. **

  78047. ** The prepared statements need to know in advance the complete set of

  78048. ** attached databases that will be use.  A mask of these databases

  78049. ** is maintained in p->btreeMask.  The p->lockMask value is the subset of

  78050. ** p->btreeMask of databases that will require a lock.

  78051. */

  78052. SQLITE_PRIVATE void sqlite3VdbeUsesBtree(Vdbe *p, int i){

  78053.   assert( i>=0 && i<p->db->nDb && i<(int)sizeof(yDbMask)*8 );

  78054.   assert( i<(int)sizeof(p->btreeMask)*8 );

  78055.   DbMaskSet(p->btreeMask, i);

  78056.   if( i!=1 && sqlite3BtreeSharable(p->db->aDb[i].pBt) ){

  78057.     DbMaskSet(p->lockMask, i);

  78058.   }

  78059. }

  78060. 

  78061. #if !defined(SQLITE_OMIT_SHARED_CACHE)

  78062. /*

  78063. ** If SQLite is compiled to support shared-cache mode and to be threadsafe,

  78064. ** this routine obtains the mutex associated with each BtShared structure

  78065. ** that may be accessed by the VM passed as an argument. In doing so it also

  78066. ** sets the BtShared.db member of each of the BtShared structures, ensuring

  78067. ** that the correct busy-handler callback is invoked if required.

  78068. **

  78069. ** If SQLite is not threadsafe but does support shared-cache mode, then

  78070. ** sqlite3BtreeEnter() is invoked to set the BtShared.db variables

  78071. ** of all of BtShared structures accessible via the database handle 

  78072. ** associated with the VM.

  78073. **

  78074. ** If SQLite is not threadsafe and does not support shared-cache mode, this

  78075. ** function is a no-op.

  78076. **

  78077. ** The p->btreeMask field is a bitmask of all btrees that the prepared 

  78078. ** statement p will ever use.  Let N be the number of bits in p->btreeMask

  78079. ** corresponding to btrees that use shared cache.  Then the runtime of

  78080. ** this routine is N*N.  But as N is rarely more than 1, this should not

  78081. ** be a problem.

  78082. */

  78083. SQLITE_PRIVATE void sqlite3VdbeEnter(Vdbe *p){

  78084.   int i;

  78085.   sqlite3 *db;

  78086.   Db *aDb;

  78087.   int nDb;

  78088.   if( DbMaskAllZero(p->lockMask) ) return;  /* The common case */

  78089.   db = p->db;

  78090.   aDb = db->aDb;

  78091.   nDb = db->nDb;

  78092.   for(i=0; i<nDb; i++){

  78093.     if( i!=1 && DbMaskTest(p->lockMask,i) && ALWAYS(aDb[i].pBt!=0) ){

  78094.       sqlite3BtreeEnter(aDb[i].pBt);

  78095.     }

  78096.   }

  78097. }

  78098. #endif

  78099. 

  78100. #if !defined(SQLITE_OMIT_SHARED_CACHE) && SQLITE_THREADSAFE>0

  78101. /*

  78102. ** Unlock all of the btrees previously locked by a call to sqlite3VdbeEnter().

  78103. */

  78104. static SQLITE_NOINLINE void vdbeLeave(Vdbe *p){

  78105.   int i;

  78106.   sqlite3 *db;

  78107.   Db *aDb;

  78108.   int nDb;

  78109.   db = p->db;

  78110.   aDb = db->aDb;

  78111.   nDb = db->nDb;

  78112.   for(i=0; i<nDb; i++){

  78113.     if( i!=1 && DbMaskTest(p->lockMask,i) && ALWAYS(aDb[i].pBt!=0) ){

  78114.       sqlite3BtreeLeave(aDb[i].pBt);

  78115.     }

  78116.   }

  78117. }

  78118. SQLITE_PRIVATE void sqlite3VdbeLeave(Vdbe *p){

  78119.   if( DbMaskAllZero(p->lockMask) ) return;  /* The common case */

  78120.   vdbeLeave(p);

  78121. }

  78122. #endif

  78123. 

  78124. #if defined(VDBE_PROFILE) || defined(SQLITE_DEBUG)

  78125. /*

  78126. ** Print a single opcode.  This routine is used for debugging only.

  78127. */

  78128. SQLITE_PRIVATE void sqlite3VdbePrintOp(FILE *pOut, int pc, VdbeOp *pOp){

  78129.   char *zP4;

  78130.   char zPtr[50];

  78131.   char zCom[100];

  78132.   static const char *zFormat1 = "%4d %-13s %4d %4d %4d %-13s %.2X %s\n";

  78133.   if( pOut==0 ) pOut = stdout;

  78134.   zP4 = displayP4(pOp, zPtr, sizeof(zPtr));

  78135. #ifdef SQLITE_ENABLE_EXPLAIN_COMMENTS

  78136.   displayComment(pOp, zP4, zCom, sizeof(zCom));

  78137. #else

  78138.   zCom[0] = 0;

  78139. #endif

  78140.   /* NB:  The sqlite3OpcodeName() function is implemented by code created

  78141.   ** by the mkopcodeh.awk and mkopcodec.awk scripts which extract the

  78142.   ** information from the vdbe.c source text */

  78143.   fprintf(pOut, zFormat1, pc, 

  78144.       sqlite3OpcodeName(pOp->opcode), pOp->p1, pOp->p2, pOp->p3, zP4, pOp->p5,

  78145.       zCom

  78146.   );

  78147.   fflush(pOut);

  78148. }

  78149. #endif

  78150. 

  78151. /*

  78152. ** Initialize an array of N Mem element.

  78153. */

  78154. static void initMemArray(Mem *p, int N, sqlite3 *db, u16 flags){

  78155.   while( (N--)>0 ){

  78156.     p->db = db;

  78157.     p->flags = flags;

  78158.     p->szMalloc = 0;

  78159. #ifdef SQLITE_DEBUG

  78160.     p->pScopyFrom = 0;

  78161. #endif

  78162.     p++;

  78163.   }

  78164. }

  78165. 

  78166. /*

  78167. ** Release an array of N Mem elements

  78168. */

  78169. static void releaseMemArray(Mem *p, int N){

  78170.   if( p && N ){

  78171.     Mem *pEnd = &p[N];

  78172.     sqlite3 *db = p->db;

  78173.     if( db->pnBytesFreed ){

  78174.       do{

  78175.         if( p->szMalloc ) sqlite3DbFree(db, p->zMalloc);

  78176.       }while( (++p)<pEnd );

  78177.       return;

  78178.     }

  78179.     do{

  78180.       assert( (&p[1])==pEnd || p[0].db==p[1].db );

  78181.       assert( sqlite3VdbeCheckMemInvariants(p) );

  78182. 

  78183.       /* This block is really an inlined version of sqlite3VdbeMemRelease()

  78184.       ** that takes advantage of the fact that the memory cell value is 

  78185.       ** being set to NULL after releasing any dynamic resources.

  78186.       **

  78187.       ** The justification for duplicating code is that according to 

  78188.       ** callgrind, this causes a certain test case to hit the CPU 4.7 

  78189.       ** percent less (x86 linux, gcc version 4.1.2, -O6) than if 

  78190.       ** sqlite3MemRelease() were called from here. With -O2, this jumps

  78191.       ** to 6.6 percent. The test case is inserting 1000 rows into a table 

  78192.       ** with no indexes using a single prepared INSERT statement, bind() 

  78193.       ** and reset(). Inserts are grouped into a transaction.

  78194.       */

  78195.       testcase( p->flags & MEM_Agg );

  78196.       testcase( p->flags & MEM_Dyn );

  78197.       testcase( p->xDel==sqlite3VdbeFrameMemDel );

  78198.       if( p->flags&(MEM_Agg|MEM_Dyn) ){

  78199.         sqlite3VdbeMemRelease(p);

  78200.       }else if( p->szMalloc ){

  78201.         sqlite3DbFreeNN(db, p->zMalloc);

  78202.         p->szMalloc = 0;

  78203.       }

  78204. 

  78205.       p->flags = MEM_Undefined;

  78206.     }while( (++p)<pEnd );

  78207.   }

  78208. }

  78209. 

  78210. #ifdef SQLITE_DEBUG

  78211. /*

  78212. ** Verify that pFrame is a valid VdbeFrame pointer.  Return true if it is

  78213. ** and false if something is wrong.

  78214. **

  78215. ** This routine is intended for use inside of assert() statements only.

  78216. */

  78217. SQLITE_PRIVATE int sqlite3VdbeFrameIsValid(VdbeFrame *pFrame){

  78218.   if( pFrame->iFrameMagic!=SQLITE_FRAME_MAGIC ) return 0;

  78219.   return 1;

  78220. }

  78221. #endif

  78222. 

  78223. 

  78224. /*

  78225. ** This is a destructor on a Mem object (which is really an sqlite3_value)

  78226. ** that deletes the Frame object that is attached to it as a blob.

  78227. **

  78228. ** This routine does not delete the Frame right away.  It merely adds the

  78229. ** frame to a list of frames to be deleted when the Vdbe halts.

  78230. */

  78231. SQLITE_PRIVATE void sqlite3VdbeFrameMemDel(void *pArg){

  78232.   VdbeFrame *pFrame = (VdbeFrame*)pArg;

  78233.   assert( sqlite3VdbeFrameIsValid(pFrame) );

  78234.   pFrame->pParent = pFrame->v->pDelFrame;

  78235.   pFrame->v->pDelFrame = pFrame;

  78236. }

  78237. 

  78238. 

  78239. /*

  78240. ** Delete a VdbeFrame object and its contents. VdbeFrame objects are

  78241. ** allocated by the OP_Program opcode in sqlite3VdbeExec().

  78242. */

  78243. SQLITE_PRIVATE void sqlite3VdbeFrameDelete(VdbeFrame *p){

  78244.   int i;

  78245.   Mem *aMem = VdbeFrameMem(p);

  78246.   VdbeCursor **apCsr = (VdbeCursor **)&aMem[p->nChildMem];

  78247.   assert( sqlite3VdbeFrameIsValid(p) );

  78248.   for(i=0; i<p->nChildCsr; i++){

  78249.     sqlite3VdbeFreeCursor(p->v, apCsr[i]);

  78250.   }

  78251.   releaseMemArray(aMem, p->nChildMem);

  78252.   sqlite3VdbeDeleteAuxData(p->v->db, &p->pAuxData, -1, 0);

  78253.   sqlite3DbFree(p->v->db, p);

  78254. }

  78255. 

  78256. #ifndef SQLITE_OMIT_EXPLAIN

  78257. /*

  78258. ** Give a listing of the program in the virtual machine.

  78259. **

  78260. ** The interface is the same as sqlite3VdbeExec().  But instead of

  78261. ** running the code, it invokes the callback once for each instruction.

  78262. ** This feature is used to implement "EXPLAIN".

  78263. **

  78264. ** When p->explain==1, each instruction is listed.  When

  78265. ** p->explain==2, only OP_Explain instructions are listed and these

  78266. ** are shown in a different format.  p->explain==2 is used to implement

  78267. ** EXPLAIN QUERY PLAN.

  78268. ** 2018-04-24:  In p->explain==2 mode, the OP_Init opcodes of triggers

  78269. ** are also shown, so that the boundaries between the main program and

  78270. ** each trigger are clear.

  78271. **

  78272. ** When p->explain==1, first the main program is listed, then each of

  78273. ** the trigger subprograms are listed one by one.

  78274. */

  78275. SQLITE_PRIVATE int sqlite3VdbeList(

  78276.   Vdbe *p                   /* The VDBE */

  78277. ){

  78278.   int nRow;                            /* Stop when row count reaches this */

  78279.   int nSub = 0;                        /* Number of sub-vdbes seen so far */

  78280.   SubProgram **apSub = 0;              /* Array of sub-vdbes */

  78281.   Mem *pSub = 0;                       /* Memory cell hold array of subprogs */

  78282.   sqlite3 *db = p->db;                 /* The database connection */

  78283.   int i;                               /* Loop counter */

  78284.   int rc = SQLITE_OK;                  /* Return code */

  78285.   Mem *pMem = &p->aMem[1];             /* First Mem of result set */

  78286.   int bListSubprogs = (p->explain==1 || (db->flags & SQLITE_TriggerEQP)!=0);

  78287.   Op *pOp = 0;

  78288. 

  78289.   assert( p->explain );

  78290.   assert( p->magic==VDBE_MAGIC_RUN );

  78291.   assert( p->rc==SQLITE_OK || p->rc==SQLITE_BUSY || p->rc==SQLITE_NOMEM );

  78292. 

  78293.   /* Even though this opcode does not use dynamic strings for

  78294.   ** the result, result columns may become dynamic if the user calls

  78295.   ** sqlite3_column_text16(), causing a translation to UTF-16 encoding.

  78296.   */

  78297.   releaseMemArray(pMem, 8);

  78298.   p->pResultSet = 0;

  78299. 

  78300.   if( p->rc==SQLITE_NOMEM ){

  78301.     /* This happens if a malloc() inside a call to sqlite3_column_text() or

  78302.     ** sqlite3_column_text16() failed.  */

  78303.     sqlite3OomFault(db);

  78304.     return SQLITE_ERROR;

  78305.   }

  78306. 

  78307.   /* When the number of output rows reaches nRow, that means the

  78308.   ** listing has finished and sqlite3_step() should return SQLITE_DONE.

  78309.   ** nRow is the sum of the number of rows in the main program, plus

  78310.   ** the sum of the number of rows in all trigger subprograms encountered

  78311.   ** so far.  The nRow value will increase as new trigger subprograms are

  78312.   ** encountered, but p->pc will eventually catch up to nRow.

  78313.   */

  78314.   nRow = p->nOp;

  78315.   if( bListSubprogs ){

  78316.     /* The first 8 memory cells are used for the result set.  So we will

  78317.     ** commandeer the 9th cell to use as storage for an array of pointers

  78318.     ** to trigger subprograms.  The VDBE is guaranteed to have at least 9

  78319.     ** cells.  */

  78320.     assert( p->nMem>9 );

  78321.     pSub = &p->aMem[9];

  78322.     if( pSub->flags&MEM_Blob ){

  78323.       /* On the first call to sqlite3_step(), pSub will hold a NULL.  It is

  78324.       ** initialized to a BLOB by the P4_SUBPROGRAM processing logic below */

  78325.       nSub = pSub->n/sizeof(Vdbe*);

  78326.       apSub = (SubProgram **)pSub->z;

  78327.     }

  78328.     for(i=0; i<nSub; i++){

  78329.       nRow += apSub[i]->nOp;

  78330.     }

  78331.   }

  78332. 

  78333.   while(1){  /* Loop exits via break */

  78334.     i = p->pc++;

  78335.     if( i>=nRow ){

  78336.       p->rc = SQLITE_OK;

  78337.       rc = SQLITE_DONE;

  78338.       break;

  78339.     }

  78340.     if( i<p->nOp ){

  78341.       /* The output line number is small enough that we are still in the

  78342.       ** main program. */

  78343.       pOp = &p->aOp[i];

  78344.     }else{

  78345.       /* We are currently listing subprograms.  Figure out which one and

  78346.       ** pick up the appropriate opcode. */

  78347.       int j;

  78348.       i -= p->nOp;

  78349.       for(j=0; i>=apSub[j]->nOp; j++){

  78350.         i -= apSub[j]->nOp;

  78351.       }

  78352.       pOp = &apSub[j]->aOp[i];

  78353.     }

  78354. 

  78355.     /* When an OP_Program opcode is encounter (the only opcode that has

  78356.     ** a P4_SUBPROGRAM argument), expand the size of the array of subprograms

  78357.     ** kept in p->aMem[9].z to hold the new program - assuming this subprogram

  78358.     ** has not already been seen.

  78359.     */

  78360.     if( bListSubprogs && pOp->p4type==P4_SUBPROGRAM ){

  78361.       int nByte = (nSub+1)*sizeof(SubProgram*);

  78362.       int j;

  78363.       for(j=0; j<nSub; j++){

  78364.         if( apSub[j]==pOp->p4.pProgram ) break;

  78365.       }

  78366.       if( j==nSub ){

  78367.         p->rc = sqlite3VdbeMemGrow(pSub, nByte, nSub!=0);

  78368.         if( p->rc!=SQLITE_OK ){

  78369.           rc = SQLITE_ERROR;

  78370.           break;

  78371.         }

  78372.         apSub = (SubProgram **)pSub->z;

  78373.         apSub[nSub++] = pOp->p4.pProgram;

  78374.         pSub->flags |= MEM_Blob;

  78375.         pSub->n = nSub*sizeof(SubProgram*);

  78376.         nRow += pOp->p4.pProgram->nOp;

  78377.       }

  78378.     }

  78379.     if( p->explain<2 ) break;

  78380.     if( pOp->opcode==OP_Explain ) break;

  78381.     if( pOp->opcode==OP_Init && p->pc>1 ) break;

  78382.   }

  78383. 

  78384.   if( rc==SQLITE_OK ){

  78385.     if( db->u1.isInterrupted ){

  78386.       p->rc = SQLITE_INTERRUPT;

  78387.       rc = SQLITE_ERROR;

  78388.       sqlite3VdbeError(p, sqlite3ErrStr(p->rc));

  78389.     }else{

  78390.       char *zP4;

  78391.       if( p->explain==1 ){

  78392.         pMem->flags = MEM_Int;

  78393.         pMem->u.i = i;                                /* Program counter */

  78394.         pMem++;

  78395.     

  78396.         pMem->flags = MEM_Static|MEM_Str|MEM_Term;

  78397.         pMem->z = (char*)sqlite3OpcodeName(pOp->opcode); /* Opcode */

  78398.         assert( pMem->z!=0 );

  78399.         pMem->n = sqlite3Strlen30(pMem->z);

  78400.         pMem->enc = SQLITE_UTF8;

  78401.         pMem++;

  78402.       }

  78403. 

  78404.       pMem->flags = MEM_Int;

  78405.       pMem->u.i = pOp->p1;                          /* P1 */

  78406.       pMem++;

  78407. 

  78408.       pMem->flags = MEM_Int;

  78409.       pMem->u.i = pOp->p2;                          /* P2 */

  78410.       pMem++;

  78411. 

  78412.       pMem->flags = MEM_Int;

  78413.       pMem->u.i = pOp->p3;                          /* P3 */

  78414.       pMem++;

  78415. 

  78416.       if( sqlite3VdbeMemClearAndResize(pMem, 100) ){ /* P4 */

  78417.         assert( p->db->mallocFailed );

  78418.         return SQLITE_ERROR;

  78419.       }

  78420.       pMem->flags = MEM_Str|MEM_Term;

  78421.       zP4 = displayP4(pOp, pMem->z, pMem->szMalloc);

  78422.       if( zP4!=pMem->z ){

  78423.         pMem->n = 0;

  78424.         sqlite3VdbeMemSetStr(pMem, zP4, -1, SQLITE_UTF8, 0);

  78425.       }else{

  78426.         assert( pMem->z!=0 );

  78427.         pMem->n = sqlite3Strlen30(pMem->z);

  78428.         pMem->enc = SQLITE_UTF8;

  78429.       }

  78430.       pMem++;

  78431. 

  78432.       if( p->explain==1 ){

  78433.         if( sqlite3VdbeMemClearAndResize(pMem, 4) ){

  78434.           assert( p->db->mallocFailed );

  78435.           return SQLITE_ERROR;

  78436.         }

  78437.         pMem->flags = MEM_Str|MEM_Term;

  78438.         pMem->n = 2;

  78439.         sqlite3_snprintf(3, pMem->z, "%.2x", pOp->p5);   /* P5 */

  78440.         pMem->enc = SQLITE_UTF8;

  78441.         pMem++;

  78442.     

  78443. #ifdef SQLITE_ENABLE_EXPLAIN_COMMENTS

  78444.         if( sqlite3VdbeMemClearAndResize(pMem, 500) ){

  78445.           assert( p->db->mallocFailed );

  78446.           return SQLITE_ERROR;

  78447.         }

  78448.         pMem->flags = MEM_Str|MEM_Term;

  78449.         pMem->n = displayComment(pOp, zP4, pMem->z, 500);

  78450.         pMem->enc = SQLITE_UTF8;

  78451. #else

  78452.         pMem->flags = MEM_Null;                       /* Comment */

  78453. #endif

  78454.       }

  78455. 

  78456.       p->nResColumn = 8 - 4*(p->explain-1);

  78457.       p->pResultSet = &p->aMem[1];

  78458.       p->rc = SQLITE_OK;

  78459.       rc = SQLITE_ROW;

  78460.     }

  78461.   }

  78462.   return rc;

  78463. }

  78464. #endif /* SQLITE_OMIT_EXPLAIN */

  78465. 

  78466. #ifdef SQLITE_DEBUG

  78467. /*

  78468. ** Print the SQL that was used to generate a VDBE program.

  78469. */

  78470. SQLITE_PRIVATE void sqlite3VdbePrintSql(Vdbe *p){

  78471.   const char *z = 0;

  78472.   if( p->zSql ){

  78473.     z = p->zSql;

  78474.   }else if( p->nOp>=1 ){

  78475.     const VdbeOp *pOp = &p->aOp[0];

  78476.     if( pOp->opcode==OP_Init && pOp->p4.z!=0 ){

  78477.       z = pOp->p4.z;

  78478.       while( sqlite3Isspace(*z) ) z++;

  78479.     }

  78480.   }

  78481.   if( z ) printf("SQL: [%s]\n", z);

  78482. }

  78483. #endif

  78484. 

  78485. #if !defined(SQLITE_OMIT_TRACE) && defined(SQLITE_ENABLE_IOTRACE)

  78486. /*

  78487. ** Print an IOTRACE message showing SQL content.

  78488. */

  78489. SQLITE_PRIVATE void sqlite3VdbeIOTraceSql(Vdbe *p){

  78490.   int nOp = p->nOp;

  78491.   VdbeOp *pOp;

  78492.   if( sqlite3IoTrace==0 ) return;

  78493.   if( nOp<1 ) return;

  78494.   pOp = &p->aOp[0];

  78495.   if( pOp->opcode==OP_Init && pOp->p4.z!=0 ){

  78496.     int i, j;

  78497.     char z[1000];

  78498.     sqlite3_snprintf(sizeof(z), z, "%s", pOp->p4.z);

  78499.     for(i=0; sqlite3Isspace(z[i]); i++){}

  78500.     for(j=0; z[i]; i++){

  78501.       if( sqlite3Isspace(z[i]) ){

  78502.         if( z[i-1]!=' ' ){

  78503.           z[j++] = ' ';

  78504.         }

  78505.       }else{

  78506.         z[j++] = z[i];

  78507.       }

  78508.     }

  78509.     z[j] = 0;

  78510.     sqlite3IoTrace("SQL %s\n", z);

  78511.   }

  78512. }

  78513. #endif /* !SQLITE_OMIT_TRACE && SQLITE_ENABLE_IOTRACE */

  78514. 

  78515. /* An instance of this object describes bulk memory available for use

  78516. ** by subcomponents of a prepared statement.  Space is allocated out

  78517. ** of a ReusableSpace object by the allocSpace() routine below.

  78518. */

  78519. struct ReusableSpace {

  78520.   u8 *pSpace;            /* Available memory */

  78521.   sqlite3_int64 nFree;   /* Bytes of available memory */

  78522.   sqlite3_int64 nNeeded; /* Total bytes that could not be allocated */

  78523. };

  78524. 

  78525. /* Try to allocate nByte bytes of 8-byte aligned bulk memory for pBuf

  78526. ** from the ReusableSpace object.  Return a pointer to the allocated

  78527. ** memory on success.  If insufficient memory is available in the

  78528. ** ReusableSpace object, increase the ReusableSpace.nNeeded

  78529. ** value by the amount needed and return NULL.

  78530. **

  78531. ** If pBuf is not initially NULL, that means that the memory has already

  78532. ** been allocated by a prior call to this routine, so just return a copy

  78533. ** of pBuf and leave ReusableSpace unchanged.

  78534. **

  78535. ** This allocator is employed to repurpose unused slots at the end of the

  78536. ** opcode array of prepared state for other memory needs of the prepared

  78537. ** statement.

  78538. */

  78539. static void *allocSpace(

  78540.   struct ReusableSpace *p,  /* Bulk memory available for allocation */

  78541.   void *pBuf,               /* Pointer to a prior allocation */

  78542.   sqlite3_int64 nByte       /* Bytes of memory needed */

  78543. ){

  78544.   assert( EIGHT_BYTE_ALIGNMENT(p->pSpace) );

  78545.   if( pBuf==0 ){

  78546.     nByte = ROUND8(nByte);

  78547.     if( nByte <= p->nFree ){

  78548.       p->nFree -= nByte;

  78549.       pBuf = &p->pSpace[p->nFree];

  78550.     }else{

  78551.       p->nNeeded += nByte;

  78552.     }

  78553.   }

  78554.   assert( EIGHT_BYTE_ALIGNMENT(pBuf) );

  78555.   return pBuf;

  78556. }

  78557. 

  78558. /*

  78559. ** Rewind the VDBE back to the beginning in preparation for

  78560. ** running it.

  78561. */

  78562. SQLITE_PRIVATE void sqlite3VdbeRewind(Vdbe *p){

  78563. #if defined(SQLITE_DEBUG) || defined(VDBE_PROFILE)

  78564.   int i;

  78565. #endif

  78566.   assert( p!=0 );

  78567.   assert( p->magic==VDBE_MAGIC_INIT || p->magic==VDBE_MAGIC_RESET );

  78568. 

  78569.   /* There should be at least one opcode.

  78570.   */

  78571.   assert( p->nOp>0 );

  78572. 

  78573.   /* Set the magic to VDBE_MAGIC_RUN sooner rather than later. */

  78574.   p->magic = VDBE_MAGIC_RUN;

  78575. 

  78576. #ifdef SQLITE_DEBUG

  78577.   for(i=0; i<p->nMem; i++){

  78578.     assert( p->aMem[i].db==p->db );

  78579.   }

  78580. #endif

  78581.   p->pc = -1;

  78582.   p->rc = SQLITE_OK;

  78583.   p->errorAction = OE_Abort;

  78584.   p->nChange = 0;

  78585.   p->cacheCtr = 1;

  78586.   p->minWriteFileFormat = 255;

  78587.   p->iStatement = 0;

  78588.   p->nFkConstraint = 0;

  78589. #ifdef VDBE_PROFILE

  78590.   for(i=0; i<p->nOp; i++){

  78591.     p->aOp[i].cnt = 0;

  78592.     p->aOp[i].cycles = 0;

  78593.   }

  78594. #endif

  78595. }

  78596. 

  78597. /*

  78598. ** Prepare a virtual machine for execution for the first time after

  78599. ** creating the virtual machine.  This involves things such

  78600. ** as allocating registers and initializing the program counter.

  78601. ** After the VDBE has be prepped, it can be executed by one or more

  78602. ** calls to sqlite3VdbeExec().  

  78603. **

  78604. ** This function may be called exactly once on each virtual machine.

  78605. ** After this routine is called the VM has been "packaged" and is ready

  78606. ** to run.  After this routine is called, further calls to 

  78607. ** sqlite3VdbeAddOp() functions are prohibited.  This routine disconnects

  78608. ** the Vdbe from the Parse object that helped generate it so that the

  78609. ** the Vdbe becomes an independent entity and the Parse object can be

  78610. ** destroyed.

  78611. **

  78612. ** Use the sqlite3VdbeRewind() procedure to restore a virtual machine back

  78613. ** to its initial state after it has been run.

  78614. */

  78615. SQLITE_PRIVATE void sqlite3VdbeMakeReady(

  78616.   Vdbe *p,                       /* The VDBE */

  78617.   Parse *pParse                  /* Parsing context */

  78618. ){

  78619.   sqlite3 *db;                   /* The database connection */

  78620.   int nVar;                      /* Number of parameters */

  78621.   int nMem;                      /* Number of VM memory registers */

  78622.   int nCursor;                   /* Number of cursors required */

  78623.   int nArg;                      /* Number of arguments in subprograms */

  78624.   int n;                         /* Loop counter */

  78625.   struct ReusableSpace x;        /* Reusable bulk memory */

  78626. 

  78627.   assert( p!=0 );

  78628.   assert( p->nOp>0 );

  78629.   assert( pParse!=0 );

  78630.   assert( p->magic==VDBE_MAGIC_INIT );

  78631.   assert( pParse==p->pParse );

  78632.   db = p->db;

  78633.   assert( db->mallocFailed==0 );

  78634.   nVar = pParse->nVar;

  78635.   nMem = pParse->nMem;

  78636.   nCursor = pParse->nTab;

  78637.   nArg = pParse->nMaxArg;

  78638.   

  78639.   /* Each cursor uses a memory cell.  The first cursor (cursor 0) can

  78640.   ** use aMem[0] which is not otherwise used by the VDBE program.  Allocate

  78641.   ** space at the end of aMem[] for cursors 1 and greater.

  78642.   ** See also: allocateCursor().

  78643.   */

  78644.   nMem += nCursor;

  78645.   if( nCursor==0 && nMem>0 ) nMem++;  /* Space for aMem[0] even if not used */

  78646. 

  78647.   /* Figure out how much reusable memory is available at the end of the

  78648.   ** opcode array.  This extra memory will be reallocated for other elements

  78649.   ** of the prepared statement.

  78650.   */

  78651.   n = ROUND8(sizeof(Op)*p->nOp);              /* Bytes of opcode memory used */

  78652.   x.pSpace = &((u8*)p->aOp)[n];               /* Unused opcode memory */

  78653.   assert( EIGHT_BYTE_ALIGNMENT(x.pSpace) );

  78654.   x.nFree = ROUNDDOWN8(pParse->szOpAlloc - n);  /* Bytes of unused memory */

  78655.   assert( x.nFree>=0 );

  78656.   assert( EIGHT_BYTE_ALIGNMENT(&x.pSpace[x.nFree]) );

  78657. 

  78658.   resolveP2Values(p, &nArg);

  78659.   p->usesStmtJournal = (u8)(pParse->isMultiWrite && pParse->mayAbort);

  78660.   if( pParse->explain && nMem<10 ){

  78661.     nMem = 10;

  78662.   }

  78663.   p->expired = 0;

  78664. 

  78665.   /* Memory for registers, parameters, cursor, etc, is allocated in one or two

  78666.   ** passes.  On the first pass, we try to reuse unused memory at the 

  78667.   ** end of the opcode array.  If we are unable to satisfy all memory

  78668.   ** requirements by reusing the opcode array tail, then the second

  78669.   ** pass will fill in the remainder using a fresh memory allocation.  

  78670.   **

  78671.   ** This two-pass approach that reuses as much memory as possible from

  78672.   ** the leftover memory at the end of the opcode array.  This can significantly

  78673.   ** reduce the amount of memory held by a prepared statement.

  78674.   */

  78675.   x.nNeeded = 0;

  78676.   p->aMem = allocSpace(&x, 0, nMem*sizeof(Mem));

  78677.   p->aVar = allocSpace(&x, 0, nVar*sizeof(Mem));

  78678.   p->apArg = allocSpace(&x, 0, nArg*sizeof(Mem*));

  78679.   p->apCsr = allocSpace(&x, 0, nCursor*sizeof(VdbeCursor*));

  78680. #ifdef SQLITE_ENABLE_STMT_SCANSTATUS

  78681.   p->anExec = allocSpace(&x, 0, p->nOp*sizeof(i64));

  78682. #endif

  78683.   if( x.nNeeded ){

  78684.     x.pSpace = p->pFree = sqlite3DbMallocRawNN(db, x.nNeeded);

  78685.     x.nFree = x.nNeeded;

  78686.     if( !db->mallocFailed ){

  78687.       p->aMem = allocSpace(&x, p->aMem, nMem*sizeof(Mem));

  78688.       p->aVar = allocSpace(&x, p->aVar, nVar*sizeof(Mem));

  78689.       p->apArg = allocSpace(&x, p->apArg, nArg*sizeof(Mem*));

  78690.       p->apCsr = allocSpace(&x, p->apCsr, nCursor*sizeof(VdbeCursor*));

  78691. #ifdef SQLITE_ENABLE_STMT_SCANSTATUS

  78692.       p->anExec = allocSpace(&x, p->anExec, p->nOp*sizeof(i64));

  78693. #endif

  78694.     }

  78695.   }

  78696. 

  78697.   p->pVList = pParse->pVList;

  78698.   pParse->pVList =  0;

  78699.   p->explain = pParse->explain;

  78700.   if( db->mallocFailed ){

  78701.     p->nVar = 0;

  78702.     p->nCursor = 0;

  78703.     p->nMem = 0;

  78704.   }else{

  78705.     p->nCursor = nCursor;

  78706.     p->nVar = (ynVar)nVar;

  78707.     initMemArray(p->aVar, nVar, db, MEM_Null);

  78708.     p->nMem = nMem;

  78709.     initMemArray(p->aMem, nMem, db, MEM_Undefined);

  78710.     memset(p->apCsr, 0, nCursor*sizeof(VdbeCursor*));

  78711. #ifdef SQLITE_ENABLE_STMT_SCANSTATUS

  78712.     memset(p->anExec, 0, p->nOp*sizeof(i64));

  78713. #endif

  78714.   }

  78715.   sqlite3VdbeRewind(p);

  78716. }

  78717. 

  78718. /*

  78719. ** Close a VDBE cursor and release all the resources that cursor 

  78720. ** happens to hold.

  78721. */

  78722. SQLITE_PRIVATE void sqlite3VdbeFreeCursor(Vdbe *p, VdbeCursor *pCx){

  78723.   if( pCx==0 ){

  78724.     return;

  78725.   }

  78726.   assert( pCx->pBtx==0 || pCx->eCurType==CURTYPE_BTREE );

  78727.   switch( pCx->eCurType ){

  78728.     case CURTYPE_SORTER: {

  78729.       sqlite3VdbeSorterClose(p->db, pCx);

  78730.       break;

  78731.     }

  78732.     case CURTYPE_BTREE: {

  78733.       if( pCx->isEphemeral ){

  78734.         if( pCx->pBtx ) sqlite3BtreeClose(pCx->pBtx);

  78735.         /* The pCx->pCursor will be close automatically, if it exists, by

  78736.         ** the call above. */

  78737.       }else{

  78738.         assert( pCx->uc.pCursor!=0 );

  78739.         sqlite3BtreeCloseCursor(pCx->uc.pCursor);

  78740.       }

  78741.       break;

  78742.     }

  78743. #ifndef SQLITE_OMIT_VIRTUALTABLE

  78744.     case CURTYPE_VTAB: {

  78745.       sqlite3_vtab_cursor *pVCur = pCx->uc.pVCur;

  78746.       const sqlite3_module *pModule = pVCur->pVtab->pModule;

  78747.       assert( pVCur->pVtab->nRef>0 );

  78748.       pVCur->pVtab->nRef--;

  78749.       pModule->xClose(pVCur);

  78750.       break;

  78751.     }

  78752. #endif

  78753.   }

  78754. }

  78755. 

  78756. /*

  78757. ** Close all cursors in the current frame.

  78758. */

  78759. static void closeCursorsInFrame(Vdbe *p){

  78760.   if( p->apCsr ){

  78761.     int i;

  78762.     for(i=0; i<p->nCursor; i++){

  78763.       VdbeCursor *pC = p->apCsr[i];

  78764.       if( pC ){

  78765.         sqlite3VdbeFreeCursor(p, pC);

  78766.         p->apCsr[i] = 0;

  78767.       }

  78768.     }

  78769.   }

  78770. }

  78771. 

  78772. /*

  78773. ** Copy the values stored in the VdbeFrame structure to its Vdbe. This

  78774. ** is used, for example, when a trigger sub-program is halted to restore

  78775. ** control to the main program.

  78776. */

  78777. SQLITE_PRIVATE int sqlite3VdbeFrameRestore(VdbeFrame *pFrame){

  78778.   Vdbe *v = pFrame->v;

  78779.   closeCursorsInFrame(v);

  78780. #ifdef SQLITE_ENABLE_STMT_SCANSTATUS

  78781.   v->anExec = pFrame->anExec;

  78782. #endif

  78783.   v->aOp = pFrame->aOp;

  78784.   v->nOp = pFrame->nOp;

  78785.   v->aMem = pFrame->aMem;

  78786.   v->nMem = pFrame->nMem;

  78787.   v->apCsr = pFrame->apCsr;

  78788.   v->nCursor = pFrame->nCursor;

  78789.   v->db->lastRowid = pFrame->lastRowid;

  78790.   v->nChange = pFrame->nChange;

  78791.   v->db->nChange = pFrame->nDbChange;

  78792.   sqlite3VdbeDeleteAuxData(v->db, &v->pAuxData, -1, 0);

  78793.   v->pAuxData = pFrame->pAuxData;

  78794.   pFrame->pAuxData = 0;

  78795.   return pFrame->pc;

  78796. }

  78797. 

  78798. /*

  78799. ** Close all cursors.

  78800. **

  78801. ** Also release any dynamic memory held by the VM in the Vdbe.aMem memory 

  78802. ** cell array. This is necessary as the memory cell array may contain

  78803. ** pointers to VdbeFrame objects, which may in turn contain pointers to

  78804. ** open cursors.

  78805. */

  78806. static void closeAllCursors(Vdbe *p){

  78807.   if( p->pFrame ){

  78808.     VdbeFrame *pFrame;

  78809.     for(pFrame=p->pFrame; pFrame->pParent; pFrame=pFrame->pParent);

  78810.     sqlite3VdbeFrameRestore(pFrame);

  78811.     p->pFrame = 0;

  78812.     p->nFrame = 0;

  78813.   }

  78814.   assert( p->nFrame==0 );

  78815.   closeCursorsInFrame(p);

  78816.   if( p->aMem ){

  78817.     releaseMemArray(p->aMem, p->nMem);

  78818.   }

  78819.   while( p->pDelFrame ){

  78820.     VdbeFrame *pDel = p->pDelFrame;

  78821.     p->pDelFrame = pDel->pParent;

  78822.     sqlite3VdbeFrameDelete(pDel);

  78823.   }

  78824. 

  78825.   /* Delete any auxdata allocations made by the VM */

  78826.   if( p->pAuxData ) sqlite3VdbeDeleteAuxData(p->db, &p->pAuxData, -1, 0);

  78827.   assert( p->pAuxData==0 );

  78828. }

  78829. 

  78830. /*

  78831. ** Set the number of result columns that will be returned by this SQL

  78832. ** statement. This is now set at compile time, rather than during

  78833. ** execution of the vdbe program so that sqlite3_column_count() can

  78834. ** be called on an SQL statement before sqlite3_step().

  78835. */

  78836. SQLITE_PRIVATE void sqlite3VdbeSetNumCols(Vdbe *p, int nResColumn){

  78837.   int n;

  78838.   sqlite3 *db = p->db;

  78839. 

  78840.   if( p->nResColumn ){

  78841.     releaseMemArray(p->aColName, p->nResColumn*COLNAME_N);

  78842.     sqlite3DbFree(db, p->aColName);

  78843.   }

  78844.   n = nResColumn*COLNAME_N;

  78845.   p->nResColumn = (u16)nResColumn;

  78846.   p->aColName = (Mem*)sqlite3DbMallocRawNN(db, sizeof(Mem)*n );

  78847.   if( p->aColName==0 ) return;

  78848.   initMemArray(p->aColName, n, db, MEM_Null);

  78849. }

  78850. 

  78851. /*

  78852. ** Set the name of the idx'th column to be returned by the SQL statement.

  78853. ** zName must be a pointer to a nul terminated string.

  78854. **

  78855. ** This call must be made after a call to sqlite3VdbeSetNumCols().

  78856. **

  78857. ** The final parameter, xDel, must be one of SQLITE_DYNAMIC, SQLITE_STATIC

  78858. ** or SQLITE_TRANSIENT. If it is SQLITE_DYNAMIC, then the buffer pointed

  78859. ** to by zName will be freed by sqlite3DbFree() when the vdbe is destroyed.

  78860. */

  78861. SQLITE_PRIVATE int sqlite3VdbeSetColName(

  78862.   Vdbe *p,                         /* Vdbe being configured */

  78863.   int idx,                         /* Index of column zName applies to */

  78864.   int var,                         /* One of the COLNAME_* constants */

  78865.   const char *zName,               /* Pointer to buffer containing name */

  78866.   void (*xDel)(void*)              /* Memory management strategy for zName */

  78867. ){

  78868.   int rc;

  78869.   Mem *pColName;

  78870.   assert( idx<p->nResColumn );

  78871.   assert( var<COLNAME_N );

  78872.   if( p->db->mallocFailed ){

  78873.     assert( !zName || xDel!=SQLITE_DYNAMIC );

  78874.     return SQLITE_NOMEM_BKPT;

  78875.   }

  78876.   assert( p->aColName!=0 );

  78877.   pColName = &(p->aColName[idx+var*p->nResColumn]);

  78878.   rc = sqlite3VdbeMemSetStr(pColName, zName, -1, SQLITE_UTF8, xDel);

  78879.   assert( rc!=0 || !zName || (pColName->flags&MEM_Term)!=0 );

  78880.   return rc;

  78881. }

  78882. 

  78883. /*

  78884. ** A read or write transaction may or may not be active on database handle

  78885. ** db. If a transaction is active, commit it. If there is a

  78886. ** write-transaction spanning more than one database file, this routine

  78887. ** takes care of the master journal trickery.

  78888. */

  78889. static int vdbeCommit(sqlite3 *db, Vdbe *p){

  78890.   int i;

  78891.   int nTrans = 0;  /* Number of databases with an active write-transaction

  78892.                    ** that are candidates for a two-phase commit using a

  78893.                    ** master-journal */

  78894.   int rc = SQLITE_OK;

  78895.   int needXcommit = 0;

  78896. 

  78897. #ifdef SQLITE_OMIT_VIRTUALTABLE

  78898.   /* With this option, sqlite3VtabSync() is defined to be simply 

  78899.   ** SQLITE_OK so p is not used. 

  78900.   */

  78901.   UNUSED_PARAMETER(p);

  78902. #endif

  78903. 

  78904.   /* Before doing anything else, call the xSync() callback for any

  78905.   ** virtual module tables written in this transaction. This has to

  78906.   ** be done before determining whether a master journal file is 

  78907.   ** required, as an xSync() callback may add an attached database

  78908.   ** to the transaction.

  78909.   */

  78910.   rc = sqlite3VtabSync(db, p);

  78911. 

  78912.   /* This loop determines (a) if the commit hook should be invoked and

  78913.   ** (b) how many database files have open write transactions, not 

  78914.   ** including the temp database. (b) is important because if more than 

  78915.   ** one database file has an open write transaction, a master journal

  78916.   ** file is required for an atomic commit.

  78917.   */ 

  78918.   for(i=0; rc==SQLITE_OK && i<db->nDb; i++){ 

  78919.     Btree *pBt = db->aDb[i].pBt;

  78920.     if( sqlite3BtreeIsInTrans(pBt) ){

  78921.       /* Whether or not a database might need a master journal depends upon

  78922.       ** its journal mode (among other things).  This matrix determines which

  78923.       ** journal modes use a master journal and which do not */

  78924.       static const u8 aMJNeeded[] = {

  78925.         /* DELETE   */  1,

  78926.         /* PERSIST   */ 1,

  78927.         /* OFF       */ 0,

  78928.         /* TRUNCATE  */ 1,

  78929.         /* MEMORY    */ 0,

  78930.         /* WAL       */ 0

  78931.       };

  78932.       Pager *pPager;   /* Pager associated with pBt */

  78933.       needXcommit = 1;

  78934.       sqlite3BtreeEnter(pBt);

  78935.       pPager = sqlite3BtreePager(pBt);

  78936.       if( db->aDb[i].safety_level!=PAGER_SYNCHRONOUS_OFF

  78937.        && aMJNeeded[sqlite3PagerGetJournalMode(pPager)]

  78938.        && sqlite3PagerIsMemdb(pPager)==0

  78939.       ){ 

  78940.         assert( i!=1 );

  78941.         nTrans++;

  78942.       }

  78943.       rc = sqlite3PagerExclusiveLock(pPager);

  78944.       sqlite3BtreeLeave(pBt);

  78945.     }

  78946.   }

  78947.   if( rc!=SQLITE_OK ){

  78948.     return rc;

  78949.   }

  78950. 

  78951.   /* If there are any write-transactions at all, invoke the commit hook */

  78952.   if( needXcommit && db->xCommitCallback ){

  78953.     rc = db->xCommitCallback(db->pCommitArg);

  78954.     if( rc ){

  78955.       return SQLITE_CONSTRAINT_COMMITHOOK;

  78956.     }

  78957.   }

  78958. 

  78959.   /* The simple case - no more than one database file (not counting the

  78960.   ** TEMP database) has a transaction active.   There is no need for the

  78961.   ** master-journal.

  78962.   **

  78963.   ** If the return value of sqlite3BtreeGetFilename() is a zero length

  78964.   ** string, it means the main database is :memory: or a temp file.  In 

  78965.   ** that case we do not support atomic multi-file commits, so use the 

  78966.   ** simple case then too.

  78967.   */

  78968.   if( 0==sqlite3Strlen30(sqlite3BtreeGetFilename(db->aDb[0].pBt))

  78969.    || nTrans<=1

  78970.   ){

  78971.     for(i=0; rc==SQLITE_OK && i<db->nDb; i++){

  78972.       Btree *pBt = db->aDb[i].pBt;

  78973.       if( pBt ){

  78974.         rc = sqlite3BtreeCommitPhaseOne(pBt, 0);

  78975.       }

  78976.     }

  78977. 

  78978.     /* Do the commit only if all databases successfully complete phase 1. 

  78979.     ** If one of the BtreeCommitPhaseOne() calls fails, this indicates an

  78980.     ** IO error while deleting or truncating a journal file. It is unlikely,

  78981.     ** but could happen. In this case abandon processing and return the error.

  78982.     */

  78983.     for(i=0; rc==SQLITE_OK && i<db->nDb; i++){

  78984.       Btree *pBt = db->aDb[i].pBt;

  78985.       if( pBt ){

  78986.         rc = sqlite3BtreeCommitPhaseTwo(pBt, 0);

  78987.       }

  78988.     }

  78989.     if( rc==SQLITE_OK ){

  78990.       sqlite3VtabCommit(db);

  78991.     }

  78992.   }

  78993. 

  78994.   /* The complex case - There is a multi-file write-transaction active.

  78995.   ** This requires a master journal file to ensure the transaction is

  78996.   ** committed atomically.

  78997.   */

  78998. #ifndef SQLITE_OMIT_DISKIO

  78999.   else{

  79000.     sqlite3_vfs *pVfs = db->pVfs;

  79001.     char *zMaster = 0;   /* File-name for the master journal */

  79002.     char const *zMainFile = sqlite3BtreeGetFilename(db->aDb[0].pBt);

  79003.     sqlite3_file *pMaster = 0;

  79004.     i64 offset = 0;

  79005.     int res;

  79006.     int retryCount = 0;

  79007.     int nMainFile;

  79008. 

  79009.     /* Select a master journal file name */

  79010.     nMainFile = sqlite3Strlen30(zMainFile);

  79011.     zMaster = sqlite3MPrintf(db, "%s-mjXXXXXX9XXz", zMainFile);

  79012.     if( zMaster==0 ) return SQLITE_NOMEM_BKPT;

  79013.     do {

  79014.       u32 iRandom;

  79015.       if( retryCount ){

  79016.         if( retryCount>100 ){

  79017.           sqlite3_log(SQLITE_FULL, "MJ delete: %s", zMaster);

  79018.           sqlite3OsDelete(pVfs, zMaster, 0);

  79019.           break;

  79020.         }else if( retryCount==1 ){

  79021.           sqlite3_log(SQLITE_FULL, "MJ collide: %s", zMaster);

  79022.         }

  79023.       }

  79024.       retryCount++;

  79025.       sqlite3_randomness(sizeof(iRandom), &iRandom);

  79026.       sqlite3_snprintf(13, &zMaster[nMainFile], "-mj%06X9%02X",

  79027.                                (iRandom>>8)&0xffffff, iRandom&0xff);

  79028.       /* The antipenultimate character of the master journal name must

  79029.       ** be "9" to avoid name collisions when using 8+3 filenames. */

  79030.       assert( zMaster[sqlite3Strlen30(zMaster)-3]=='9' );

  79031.       sqlite3FileSuffix3(zMainFile, zMaster);

  79032.       rc = sqlite3OsAccess(pVfs, zMaster, SQLITE_ACCESS_EXISTS, &res);

  79033.     }while( rc==SQLITE_OK && res );

  79034.     if( rc==SQLITE_OK ){

  79035.       /* Open the master journal. */

  79036.       rc = sqlite3OsOpenMalloc(pVfs, zMaster, &pMaster, 

  79037.           SQLITE_OPEN_READWRITE|SQLITE_OPEN_CREATE|

  79038.           SQLITE_OPEN_EXCLUSIVE|SQLITE_OPEN_MASTER_JOURNAL, 0

  79039.       );

  79040.     }

  79041.     if( rc!=SQLITE_OK ){

  79042.       sqlite3DbFree(db, zMaster);

  79043.       return rc;

  79044.     }

  79045.  

  79046.     /* Write the name of each database file in the transaction into the new

  79047.     ** master journal file. If an error occurs at this point close

  79048.     ** and delete the master journal file. All the individual journal files

  79049.     ** still have 'null' as the master journal pointer, so they will roll

  79050.     ** back independently if a failure occurs.

  79051.     */

  79052.     for(i=0; i<db->nDb; i++){

  79053.       Btree *pBt = db->aDb[i].pBt;

  79054.       if( sqlite3BtreeIsInTrans(pBt) ){

  79055.         char const *zFile = sqlite3BtreeGetJournalname(pBt);

  79056.         if( zFile==0 ){

  79057.           continue;  /* Ignore TEMP and :memory: databases */

  79058.         }

  79059.         assert( zFile[0]!=0 );

  79060.         rc = sqlite3OsWrite(pMaster, zFile, sqlite3Strlen30(zFile)+1, offset);

  79061.         offset += sqlite3Strlen30(zFile)+1;

  79062.         if( rc!=SQLITE_OK ){

  79063.           sqlite3OsCloseFree(pMaster);

  79064.           sqlite3OsDelete(pVfs, zMaster, 0);

  79065.           sqlite3DbFree(db, zMaster);

  79066.           return rc;

  79067.         }

  79068.       }

  79069.     }

  79070. 

  79071.     /* Sync the master journal file. If the IOCAP_SEQUENTIAL device

  79072.     ** flag is set this is not required.

  79073.     */

  79074.     if( 0==(sqlite3OsDeviceCharacteristics(pMaster)&SQLITE_IOCAP_SEQUENTIAL)

  79075.      && SQLITE_OK!=(rc = sqlite3OsSync(pMaster, SQLITE_SYNC_NORMAL))

  79076.     ){

  79077.       sqlite3OsCloseFree(pMaster);

  79078.       sqlite3OsDelete(pVfs, zMaster, 0);

  79079.       sqlite3DbFree(db, zMaster);

  79080.       return rc;

  79081.     }

  79082. 

  79083.     /* Sync all the db files involved in the transaction. The same call

  79084.     ** sets the master journal pointer in each individual journal. If

  79085.     ** an error occurs here, do not delete the master journal file.

  79086.     **

  79087.     ** If the error occurs during the first call to

  79088.     ** sqlite3BtreeCommitPhaseOne(), then there is a chance that the

  79089.     ** master journal file will be orphaned. But we cannot delete it,

  79090.     ** in case the master journal file name was written into the journal

  79091.     ** file before the failure occurred.

  79092.     */

  79093.     for(i=0; rc==SQLITE_OK && i<db->nDb; i++){ 

  79094.       Btree *pBt = db->aDb[i].pBt;

  79095.       if( pBt ){

  79096.         rc = sqlite3BtreeCommitPhaseOne(pBt, zMaster);

  79097.       }

  79098.     }

  79099.     sqlite3OsCloseFree(pMaster);

  79100.     assert( rc!=SQLITE_BUSY );

  79101.     if( rc!=SQLITE_OK ){

  79102.       sqlite3DbFree(db, zMaster);

  79103.       return rc;

  79104.     }

  79105. 

  79106.     /* Delete the master journal file. This commits the transaction. After

  79107.     ** doing this the directory is synced again before any individual

  79108.     ** transaction files are deleted.

  79109.     */

  79110.     rc = sqlite3OsDelete(pVfs, zMaster, 1);

  79111.     sqlite3DbFree(db, zMaster);

  79112.     zMaster = 0;

  79113.     if( rc ){

  79114.       return rc;

  79115.     }

  79116. 

  79117.     /* All files and directories have already been synced, so the following

  79118.     ** calls to sqlite3BtreeCommitPhaseTwo() are only closing files and

  79119.     ** deleting or truncating journals. If something goes wrong while

  79120.     ** this is happening we don't really care. The integrity of the

  79121.     ** transaction is already guaranteed, but some stray 'cold' journals

  79122.     ** may be lying around. Returning an error code won't help matters.

  79123.     */

  79124.     disable_simulated_io_errors();

  79125.     sqlite3BeginBenignMalloc();

  79126.     for(i=0; i<db->nDb; i++){ 

  79127.       Btree *pBt = db->aDb[i].pBt;

  79128.       if( pBt ){

  79129.         sqlite3BtreeCommitPhaseTwo(pBt, 1);

  79130.       }

  79131.     }

  79132.     sqlite3EndBenignMalloc();

  79133.     enable_simulated_io_errors();

  79134. 

  79135.     sqlite3VtabCommit(db);

  79136.   }

  79137. #endif

  79138. 

  79139.   return rc;

  79140. }

  79141. 

  79142. /* 

  79143. ** This routine checks that the sqlite3.nVdbeActive count variable

  79144. ** matches the number of vdbe's in the list sqlite3.pVdbe that are

  79145. ** currently active. An assertion fails if the two counts do not match.

  79146. ** This is an internal self-check only - it is not an essential processing

  79147. ** step.

  79148. **

  79149. ** This is a no-op if NDEBUG is defined.

  79150. */

  79151. #ifndef NDEBUG

  79152. static void checkActiveVdbeCnt(sqlite3 *db){

  79153.   Vdbe *p;

  79154.   int cnt = 0;

  79155.   int nWrite = 0;

  79156.   int nRead = 0;

  79157.   p = db->pVdbe;

  79158.   while( p ){

  79159.     if( sqlite3_stmt_busy((sqlite3_stmt*)p) ){

  79160.       cnt++;

  79161.       if( p->readOnly==0 ) nWrite++;

  79162.       if( p->bIsReader ) nRead++;

  79163.     }

  79164.     p = p->pNext;

  79165.   }

  79166.   assert( cnt==db->nVdbeActive );

  79167.   assert( nWrite==db->nVdbeWrite );

  79168.   assert( nRead==db->nVdbeRead );

  79169. }

  79170. #else

  79171. #define checkActiveVdbeCnt(x)

  79172. #endif

  79173. 

  79174. /*

  79175. ** If the Vdbe passed as the first argument opened a statement-transaction,

  79176. ** close it now. Argument eOp must be either SAVEPOINT_ROLLBACK or

  79177. ** SAVEPOINT_RELEASE. If it is SAVEPOINT_ROLLBACK, then the statement

  79178. ** transaction is rolled back. If eOp is SAVEPOINT_RELEASE, then the 

  79179. ** statement transaction is committed.

  79180. **

  79181. ** If an IO error occurs, an SQLITE_IOERR_XXX error code is returned. 

  79182. ** Otherwise SQLITE_OK.

  79183. */

  79184. static SQLITE_NOINLINE int vdbeCloseStatement(Vdbe *p, int eOp){

  79185.   sqlite3 *const db = p->db;

  79186.   int rc = SQLITE_OK;

  79187.   int i;

  79188.   const int iSavepoint = p->iStatement-1;

  79189. 

  79190.   assert( eOp==SAVEPOINT_ROLLBACK || eOp==SAVEPOINT_RELEASE);

  79191.   assert( db->nStatement>0 );

  79192.   assert( p->iStatement==(db->nStatement+db->nSavepoint) );

  79193. 

  79194.   for(i=0; i<db->nDb; i++){ 

  79195.     int rc2 = SQLITE_OK;

  79196.     Btree *pBt = db->aDb[i].pBt;

  79197.     if( pBt ){

  79198.       if( eOp==SAVEPOINT_ROLLBACK ){

  79199.         rc2 = sqlite3BtreeSavepoint(pBt, SAVEPOINT_ROLLBACK, iSavepoint);

  79200.       }

  79201.       if( rc2==SQLITE_OK ){

  79202.         rc2 = sqlite3BtreeSavepoint(pBt, SAVEPOINT_RELEASE, iSavepoint);

  79203.       }

  79204.       if( rc==SQLITE_OK ){

  79205.         rc = rc2;

  79206.       }

  79207.     }

  79208.   }

  79209.   db->nStatement--;

  79210.   p->iStatement = 0;

  79211. 

  79212.   if( rc==SQLITE_OK ){

  79213.     if( eOp==SAVEPOINT_ROLLBACK ){

  79214.       rc = sqlite3VtabSavepoint(db, SAVEPOINT_ROLLBACK, iSavepoint);

  79215.     }

  79216.     if( rc==SQLITE_OK ){

  79217.       rc = sqlite3VtabSavepoint(db, SAVEPOINT_RELEASE, iSavepoint);

  79218.     }

  79219.   }

  79220. 

  79221.   /* If the statement transaction is being rolled back, also restore the 

  79222.   ** database handles deferred constraint counter to the value it had when 

  79223.   ** the statement transaction was opened.  */

  79224.   if( eOp==SAVEPOINT_ROLLBACK ){

  79225.     db->nDeferredCons = p->nStmtDefCons;

  79226.     db->nDeferredImmCons = p->nStmtDefImmCons;

  79227.   }

  79228.   return rc;

  79229. }

  79230. SQLITE_PRIVATE int sqlite3VdbeCloseStatement(Vdbe *p, int eOp){

  79231.   if( p->db->nStatement && p->iStatement ){

  79232.     return vdbeCloseStatement(p, eOp);

  79233.   }

  79234.   return SQLITE_OK;

  79235. }

  79236. 

  79237. 

  79238. /*

  79239. ** This function is called when a transaction opened by the database 

  79240. ** handle associated with the VM passed as an argument is about to be 

  79241. ** committed. If there are outstanding deferred foreign key constraint

  79242. ** violations, return SQLITE_ERROR. Otherwise, SQLITE_OK.

  79243. **

  79244. ** If there are outstanding FK violations and this function returns 

  79245. ** SQLITE_ERROR, set the result of the VM to SQLITE_CONSTRAINT_FOREIGNKEY

  79246. ** and write an error message to it. Then return SQLITE_ERROR.

  79247. */

  79248. #ifndef SQLITE_OMIT_FOREIGN_KEY

  79249. SQLITE_PRIVATE int sqlite3VdbeCheckFk(Vdbe *p, int deferred){

  79250.   sqlite3 *db = p->db;

  79251.   if( (deferred && (db->nDeferredCons+db->nDeferredImmCons)>0) 

  79252.    || (!deferred && p->nFkConstraint>0) 

  79253.   ){

  79254.     p->rc = SQLITE_CONSTRAINT_FOREIGNKEY;

  79255.     p->errorAction = OE_Abort;

  79256.     sqlite3VdbeError(p, "FOREIGN KEY constraint failed");

  79257.     return SQLITE_ERROR;

  79258.   }

  79259.   return SQLITE_OK;

  79260. }

  79261. #endif

  79262. 

  79263. /*

  79264. ** This routine is called the when a VDBE tries to halt.  If the VDBE

  79265. ** has made changes and is in autocommit mode, then commit those

  79266. ** changes.  If a rollback is needed, then do the rollback.

  79267. **

  79268. ** This routine is the only way to move the state of a VM from

  79269. ** SQLITE_MAGIC_RUN to SQLITE_MAGIC_HALT.  It is harmless to

  79270. ** call this on a VM that is in the SQLITE_MAGIC_HALT state.

  79271. **

  79272. ** Return an error code.  If the commit could not complete because of

  79273. ** lock contention, return SQLITE_BUSY.  If SQLITE_BUSY is returned, it

  79274. ** means the close did not happen and needs to be repeated.

  79275. */

  79276. SQLITE_PRIVATE int sqlite3VdbeHalt(Vdbe *p){

  79277.   int rc;                         /* Used to store transient return codes */

  79278.   sqlite3 *db = p->db;

  79279. 

  79280.   /* This function contains the logic that determines if a statement or

  79281.   ** transaction will be committed or rolled back as a result of the

  79282.   ** execution of this virtual machine. 

  79283.   **

  79284.   ** If any of the following errors occur:

  79285.   **

  79286.   **     SQLITE_NOMEM

  79287.   **     SQLITE_IOERR

  79288.   **     SQLITE_FULL

  79289.   **     SQLITE_INTERRUPT

  79290.   **

  79291.   ** Then the internal cache might have been left in an inconsistent

  79292.   ** state.  We need to rollback the statement transaction, if there is

  79293.   ** one, or the complete transaction if there is no statement transaction.

  79294.   */

  79295. 

  79296.   if( p->magic!=VDBE_MAGIC_RUN ){

  79297.     return SQLITE_OK;

  79298.   }

  79299.   if( db->mallocFailed ){

  79300.     p->rc = SQLITE_NOMEM_BKPT;

  79301.   }

  79302.   closeAllCursors(p);

  79303.   checkActiveVdbeCnt(db);

  79304. 

  79305.   /* No commit or rollback needed if the program never started or if the

  79306.   ** SQL statement does not read or write a database file.  */

  79307.   if( p->pc>=0 && p->bIsReader ){

  79308.     int mrc;   /* Primary error code from p->rc */

  79309.     int eStatementOp = 0;

  79310.     int isSpecialError;            /* Set to true if a 'special' error */

  79311. 

  79312.     /* Lock all btrees used by the statement */

  79313.     sqlite3VdbeEnter(p);

  79314. 

  79315.     /* Check for one of the special errors */

  79316.     mrc = p->rc & 0xff;

  79317.     isSpecialError = mrc==SQLITE_NOMEM || mrc==SQLITE_IOERR

  79318.                      || mrc==SQLITE_INTERRUPT || mrc==SQLITE_FULL;

  79319.     if( isSpecialError ){

  79320.       /* If the query was read-only and the error code is SQLITE_INTERRUPT, 

  79321.       ** no rollback is necessary. Otherwise, at least a savepoint 

  79322.       ** transaction must be rolled back to restore the database to a 

  79323.       ** consistent state.

  79324.       **

  79325.       ** Even if the statement is read-only, it is important to perform

  79326.       ** a statement or transaction rollback operation. If the error 

  79327.       ** occurred while writing to the journal, sub-journal or database

  79328.       ** file as part of an effort to free up cache space (see function

  79329.       ** pagerStress() in pager.c), the rollback is required to restore 

  79330.       ** the pager to a consistent state.

  79331.       */

  79332.       if( !p->readOnly || mrc!=SQLITE_INTERRUPT ){

  79333.         if( (mrc==SQLITE_NOMEM || mrc==SQLITE_FULL) && p->usesStmtJournal ){

  79334.           eStatementOp = SAVEPOINT_ROLLBACK;

  79335.         }else{

  79336.           /* We are forced to roll back the active transaction. Before doing

  79337.           ** so, abort any other statements this handle currently has active.

  79338.           */

  79339.           sqlite3RollbackAll(db, SQLITE_ABORT_ROLLBACK);

  79340.           sqlite3CloseSavepoints(db);

  79341.           db->autoCommit = 1;

  79342.           p->nChange = 0;

  79343.         }

  79344.       }

  79345.     }

  79346. 

  79347.     /* Check for immediate foreign key violations. */

  79348.     if( p->rc==SQLITE_OK || (p->errorAction==OE_Fail && !isSpecialError) ){

  79349.       sqlite3VdbeCheckFk(p, 0);

  79350.     }

  79351.   

  79352.     /* If the auto-commit flag is set and this is the only active writer 

  79353.     ** VM, then we do either a commit or rollback of the current transaction. 

  79354.     **

  79355.     ** Note: This block also runs if one of the special errors handled 

  79356.     ** above has occurred. 

  79357.     */

  79358.     if( !sqlite3VtabInSync(db) 

  79359.      && db->autoCommit 

  79360.      && db->nVdbeWrite==(p->readOnly==0) 

  79361.     ){

  79362.       if( p->rc==SQLITE_OK || (p->errorAction==OE_Fail && !isSpecialError) ){

  79363.         rc = sqlite3VdbeCheckFk(p, 1);

  79364.         if( rc!=SQLITE_OK ){

  79365.           if( NEVER(p->readOnly) ){

  79366.             sqlite3VdbeLeave(p);

  79367.             return SQLITE_ERROR;

  79368.           }

  79369.           rc = SQLITE_CONSTRAINT_FOREIGNKEY;

  79370.         }else{ 

  79371.           /* The auto-commit flag is true, the vdbe program was successful 

  79372.           ** or hit an 'OR FAIL' constraint and there are no deferred foreign

  79373.           ** key constraints to hold up the transaction. This means a commit 

  79374.           ** is required. */

  79375.           rc = vdbeCommit(db, p);

  79376.         }

  79377.         if( rc==SQLITE_BUSY && p->readOnly ){

  79378.           sqlite3VdbeLeave(p);

  79379.           return SQLITE_BUSY;

  79380.         }else if( rc!=SQLITE_OK ){

  79381.           p->rc = rc;

  79382.           sqlite3RollbackAll(db, SQLITE_OK);

  79383.           p->nChange = 0;

  79384.         }else{

  79385.           db->nDeferredCons = 0;

  79386.           db->nDeferredImmCons = 0;

  79387.           db->flags &= ~(u64)SQLITE_DeferFKs;

  79388.           sqlite3CommitInternalChanges(db);

  79389.         }

  79390.       }else{

  79391.         sqlite3RollbackAll(db, SQLITE_OK);

  79392.         p->nChange = 0;

  79393.       }

  79394.       db->nStatement = 0;

  79395.     }else if( eStatementOp==0 ){

  79396.       if( p->rc==SQLITE_OK || p->errorAction==OE_Fail ){

  79397.         eStatementOp = SAVEPOINT_RELEASE;

  79398.       }else if( p->errorAction==OE_Abort ){

  79399.         eStatementOp = SAVEPOINT_ROLLBACK;

  79400.       }else{

  79401.         sqlite3RollbackAll(db, SQLITE_ABORT_ROLLBACK);

  79402.         sqlite3CloseSavepoints(db);

  79403.         db->autoCommit = 1;

  79404.         p->nChange = 0;

  79405.       }

  79406.     }

  79407.   

  79408.     /* If eStatementOp is non-zero, then a statement transaction needs to

  79409.     ** be committed or rolled back. Call sqlite3VdbeCloseStatement() to

  79410.     ** do so. If this operation returns an error, and the current statement

  79411.     ** error code is SQLITE_OK or SQLITE_CONSTRAINT, then promote the

  79412.     ** current statement error code.

  79413.     */

  79414.     if( eStatementOp ){

  79415.       rc = sqlite3VdbeCloseStatement(p, eStatementOp);

  79416.       if( rc ){

  79417.         if( p->rc==SQLITE_OK || (p->rc&0xff)==SQLITE_CONSTRAINT ){

  79418.           p->rc = rc;

  79419.           sqlite3DbFree(db, p->zErrMsg);

  79420.           p->zErrMsg = 0;

  79421.         }

  79422.         sqlite3RollbackAll(db, SQLITE_ABORT_ROLLBACK);

  79423.         sqlite3CloseSavepoints(db);

  79424.         db->autoCommit = 1;

  79425.         p->nChange = 0;

  79426.       }

  79427.     }

  79428.   

  79429.     /* If this was an INSERT, UPDATE or DELETE and no statement transaction

  79430.     ** has been rolled back, update the database connection change-counter. 

  79431.     */

  79432.     if( p->changeCntOn ){

  79433.       if( eStatementOp!=SAVEPOINT_ROLLBACK ){

  79434.         sqlite3VdbeSetChanges(db, p->nChange);

  79435.       }else{

  79436.         sqlite3VdbeSetChanges(db, 0);

  79437.       }

  79438.       p->nChange = 0;

  79439.     }

  79440. 

  79441.     /* Release the locks */

  79442.     sqlite3VdbeLeave(p);

  79443.   }

  79444. 

  79445.   /* We have successfully halted and closed the VM.  Record this fact. */

  79446.   if( p->pc>=0 ){

  79447.     db->nVdbeActive--;

  79448.     if( !p->readOnly ) db->nVdbeWrite--;

  79449.     if( p->bIsReader ) db->nVdbeRead--;

  79450.     assert( db->nVdbeActive>=db->nVdbeRead );

  79451.     assert( db->nVdbeRead>=db->nVdbeWrite );

  79452.     assert( db->nVdbeWrite>=0 );

  79453.   }

  79454.   p->magic = VDBE_MAGIC_HALT;

  79455.   checkActiveVdbeCnt(db);

  79456.   if( db->mallocFailed ){

  79457.     p->rc = SQLITE_NOMEM_BKPT;

  79458.   }

  79459. 

  79460.   /* If the auto-commit flag is set to true, then any locks that were held

  79461.   ** by connection db have now been released. Call sqlite3ConnectionUnlocked() 

  79462.   ** to invoke any required unlock-notify callbacks.

  79463.   */

  79464.   if( db->autoCommit ){

  79465.     sqlite3ConnectionUnlocked(db);

  79466.   }

  79467. 

  79468.   assert( db->nVdbeActive>0 || db->autoCommit==0 || db->nStatement==0 );

  79469.   return (p->rc==SQLITE_BUSY ? SQLITE_BUSY : SQLITE_OK);

  79470. }

  79471. 

  79472. 

  79473. /*

  79474. ** Each VDBE holds the result of the most recent sqlite3_step() call

  79475. ** in p->rc.  This routine sets that result back to SQLITE_OK.

  79476. */

  79477. SQLITE_PRIVATE void sqlite3VdbeResetStepResult(Vdbe *p){

  79478.   p->rc = SQLITE_OK;

  79479. }

  79480. 

  79481. /*

  79482. ** Copy the error code and error message belonging to the VDBE passed

  79483. ** as the first argument to its database handle (so that they will be 

  79484. ** returned by calls to sqlite3_errcode() and sqlite3_errmsg()).

  79485. **

  79486. ** This function does not clear the VDBE error code or message, just

  79487. ** copies them to the database handle.

  79488. */

  79489. SQLITE_PRIVATE int sqlite3VdbeTransferError(Vdbe *p){

  79490.   sqlite3 *db = p->db;

  79491.   int rc = p->rc;

  79492.   if( p->zErrMsg ){

  79493.     db->bBenignMalloc++;

  79494.     sqlite3BeginBenignMalloc();

  79495.     if( db->pErr==0 ) db->pErr = sqlite3ValueNew(db);

  79496.     sqlite3ValueSetStr(db->pErr, -1, p->zErrMsg, SQLITE_UTF8, SQLITE_TRANSIENT);

  79497.     sqlite3EndBenignMalloc();

  79498.     db->bBenignMalloc--;

  79499.   }else if( db->pErr ){

  79500.     sqlite3ValueSetNull(db->pErr);

  79501.   }

  79502.   db->errCode = rc;

  79503.   return rc;

  79504. }

  79505. 

  79506. #ifdef SQLITE_ENABLE_SQLLOG

  79507. /*

  79508. ** If an SQLITE_CONFIG_SQLLOG hook is registered and the VM has been run, 

  79509. ** invoke it.

  79510. */

  79511. static void vdbeInvokeSqllog(Vdbe *v){

  79512.   if( sqlite3GlobalConfig.xSqllog && v->rc==SQLITE_OK && v->zSql && v->pc>=0 ){

  79513.     char *zExpanded = sqlite3VdbeExpandSql(v, v->zSql);

  79514.     assert( v->db->init.busy==0 );

  79515.     if( zExpanded ){

  79516.       sqlite3GlobalConfig.xSqllog(

  79517.           sqlite3GlobalConfig.pSqllogArg, v->db, zExpanded, 1

  79518.       );

  79519.       sqlite3DbFree(v->db, zExpanded);

  79520.     }

  79521.   }

  79522. }

  79523. #else

  79524. # define vdbeInvokeSqllog(x)

  79525. #endif

  79526. 

  79527. /*

  79528. ** Clean up a VDBE after execution but do not delete the VDBE just yet.

  79529. ** Write any error messages into *pzErrMsg.  Return the result code.

  79530. **

  79531. ** After this routine is run, the VDBE should be ready to be executed

  79532. ** again.

  79533. **

  79534. ** To look at it another way, this routine resets the state of the

  79535. ** virtual machine from VDBE_MAGIC_RUN or VDBE_MAGIC_HALT back to

  79536. ** VDBE_MAGIC_INIT.

  79537. */

  79538. SQLITE_PRIVATE int sqlite3VdbeReset(Vdbe *p){

  79539. #if defined(SQLITE_DEBUG) || defined(VDBE_PROFILE)

  79540.   int i;

  79541. #endif

  79542. 

  79543.   sqlite3 *db;

  79544.   db = p->db;

  79545. 

  79546.   /* If the VM did not run to completion or if it encountered an

  79547.   ** error, then it might not have been halted properly.  So halt

  79548.   ** it now.

  79549.   */

  79550.   sqlite3VdbeHalt(p);

  79551. 

  79552.   /* If the VDBE has been run even partially, then transfer the error code

  79553.   ** and error message from the VDBE into the main database structure.  But

  79554.   ** if the VDBE has just been set to run but has not actually executed any

  79555.   ** instructions yet, leave the main database error information unchanged.

  79556.   */

  79557.   if( p->pc>=0 ){

  79558.     vdbeInvokeSqllog(p);

  79559.     sqlite3VdbeTransferError(p);

  79560.     if( p->runOnlyOnce ) p->expired = 1;

  79561.   }else if( p->rc && p->expired ){

  79562.     /* The expired flag was set on the VDBE before the first call

  79563.     ** to sqlite3_step(). For consistency (since sqlite3_step() was

  79564.     ** called), set the database error in this case as well.

  79565.     */

  79566.     sqlite3ErrorWithMsg(db, p->rc, p->zErrMsg ? "%s" : 0, p->zErrMsg);

  79567.   }

  79568. 

  79569.   /* Reset register contents and reclaim error message memory.

  79570.   */

  79571. #ifdef SQLITE_DEBUG

  79572.   /* Execute assert() statements to ensure that the Vdbe.apCsr[] and 

  79573.   ** Vdbe.aMem[] arrays have already been cleaned up.  */

  79574.   if( p->apCsr ) for(i=0; i<p->nCursor; i++) assert( p->apCsr[i]==0 );

  79575.   if( p->aMem ){

  79576.     for(i=0; i<p->nMem; i++) assert( p->aMem[i].flags==MEM_Undefined );

  79577.   }

  79578. #endif

  79579.   sqlite3DbFree(db, p->zErrMsg);

  79580.   p->zErrMsg = 0;

  79581.   p->pResultSet = 0;

  79582. #ifdef SQLITE_DEBUG

  79583.   p->nWrite = 0;

  79584. #endif

  79585. 

  79586.   /* Save profiling information from this VDBE run.

  79587.   */

  79588. #ifdef VDBE_PROFILE

  79589.   {

  79590.     FILE *out = fopen("vdbe_profile.out", "a");

  79591.     if( out ){

  79592.       fprintf(out, "---- ");

  79593.       for(i=0; i<p->nOp; i++){

  79594.         fprintf(out, "%02x", p->aOp[i].opcode);

  79595.       }

  79596.       fprintf(out, "\n");

  79597.       if( p->zSql ){

  79598.         char c, pc = 0;

  79599.         fprintf(out, "-- ");

  79600.         for(i=0; (c = p->zSql[i])!=0; i++){

  79601.           if( pc=='\n' ) fprintf(out, "-- ");

  79602.           putc(c, out);

  79603.           pc = c;

  79604.         }

  79605.         if( pc!='\n' ) fprintf(out, "\n");

  79606.       }

  79607.       for(i=0; i<p->nOp; i++){

  79608.         char zHdr[100];

  79609.         sqlite3_snprintf(sizeof(zHdr), zHdr, "%6u %12llu %8llu ",

  79610.            p->aOp[i].cnt,

  79611.            p->aOp[i].cycles,

  79612.            p->aOp[i].cnt>0 ? p->aOp[i].cycles/p->aOp[i].cnt : 0

  79613.         );

  79614.         fprintf(out, "%s", zHdr);

  79615.         sqlite3VdbePrintOp(out, i, &p->aOp[i]);

  79616.       }

  79617.       fclose(out);

  79618.     }

  79619.   }

  79620. #endif

  79621.   p->magic = VDBE_MAGIC_RESET;

  79622.   return p->rc & db->errMask;

  79623. }

  79624.  

  79625. /*

  79626. ** Clean up and delete a VDBE after execution.  Return an integer which is

  79627. ** the result code.  Write any error message text into *pzErrMsg.

  79628. */

  79629. SQLITE_PRIVATE int sqlite3VdbeFinalize(Vdbe *p){

  79630.   int rc = SQLITE_OK;

  79631.   if( p->magic==VDBE_MAGIC_RUN || p->magic==VDBE_MAGIC_HALT ){

  79632.     rc = sqlite3VdbeReset(p);

  79633.     assert( (rc & p->db->errMask)==rc );

  79634.   }

  79635.   sqlite3VdbeDelete(p);

  79636.   return rc;

  79637. }

  79638. 

  79639. /*

  79640. ** If parameter iOp is less than zero, then invoke the destructor for

  79641. ** all auxiliary data pointers currently cached by the VM passed as

  79642. ** the first argument.

  79643. **

  79644. ** Or, if iOp is greater than or equal to zero, then the destructor is

  79645. ** only invoked for those auxiliary data pointers created by the user 

  79646. ** function invoked by the OP_Function opcode at instruction iOp of 

  79647. ** VM pVdbe, and only then if:

  79648. **

  79649. **    * the associated function parameter is the 32nd or later (counting

  79650. **      from left to right), or

  79651. **

  79652. **    * the corresponding bit in argument mask is clear (where the first

  79653. **      function parameter corresponds to bit 0 etc.).

  79654. */

  79655. SQLITE_PRIVATE void sqlite3VdbeDeleteAuxData(sqlite3 *db, AuxData **pp, int iOp, int mask){

  79656.   while( *pp ){

  79657.     AuxData *pAux = *pp;

  79658.     if( (iOp<0)

  79659.      || (pAux->iAuxOp==iOp

  79660.           && pAux->iAuxArg>=0

  79661.           && (pAux->iAuxArg>31 || !(mask & MASKBIT32(pAux->iAuxArg))))

  79662.     ){

  79663.       testcase( pAux->iAuxArg==31 );

  79664.       if( pAux->xDeleteAux ){

  79665.         pAux->xDeleteAux(pAux->pAux);

  79666.       }

  79667.       *pp = pAux->pNextAux;

  79668.       sqlite3DbFree(db, pAux);

  79669.     }else{

  79670.       pp= &pAux->pNextAux;

  79671.     }

  79672.   }

  79673. }

  79674. 

  79675. /*

  79676. ** Free all memory associated with the Vdbe passed as the second argument,

  79677. ** except for object itself, which is preserved.

  79678. **

  79679. ** The difference between this function and sqlite3VdbeDelete() is that

  79680. ** VdbeDelete() also unlinks the Vdbe from the list of VMs associated with

  79681. ** the database connection and frees the object itself.

  79682. */

  79683. SQLITE_PRIVATE void sqlite3VdbeClearObject(sqlite3 *db, Vdbe *p){

  79684.   SubProgram *pSub, *pNext;

  79685.   assert( p->db==0 || p->db==db );

  79686.   releaseMemArray(p->aColName, p->nResColumn*COLNAME_N);

  79687.   for(pSub=p->pProgram; pSub; pSub=pNext){

  79688.     pNext = pSub->pNext;

  79689.     vdbeFreeOpArray(db, pSub->aOp, pSub->nOp);

  79690.     sqlite3DbFree(db, pSub);

  79691.   }

  79692.   if( p->magic!=VDBE_MAGIC_INIT ){

  79693.     releaseMemArray(p->aVar, p->nVar);

  79694.     sqlite3DbFree(db, p->pVList);

  79695.     sqlite3DbFree(db, p->pFree);

  79696.   }

  79697.   vdbeFreeOpArray(db, p->aOp, p->nOp);

  79698.   sqlite3DbFree(db, p->aColName);

  79699.   sqlite3DbFree(db, p->zSql);

  79700. #ifdef SQLITE_ENABLE_NORMALIZE

  79701.   sqlite3DbFree(db, p->zNormSql);

  79702.   {

  79703.     DblquoteStr *pThis, *pNext;

  79704.     for(pThis=p->pDblStr; pThis; pThis=pNext){

  79705.       pNext = pThis->pNextStr;

  79706.       sqlite3DbFree(db, pThis);

  79707.     }

  79708.   }

  79709. #endif

  79710. #ifdef SQLITE_ENABLE_STMT_SCANSTATUS

  79711.   {

  79712.     int i;

  79713.     for(i=0; i<p->nScan; i++){

  79714.       sqlite3DbFree(db, p->aScan[i].zName);

  79715.     }

  79716.     sqlite3DbFree(db, p->aScan);

  79717.   }

  79718. #endif

  79719. }

  79720. 

  79721. /*

  79722. ** Delete an entire VDBE.

  79723. */

  79724. SQLITE_PRIVATE void sqlite3VdbeDelete(Vdbe *p){

  79725.   sqlite3 *db;

  79726. 

  79727.   assert( p!=0 );

  79728.   db = p->db;

  79729.   assert( sqlite3_mutex_held(db->mutex) );

  79730.   sqlite3VdbeClearObject(db, p);

  79731.   if( p->pPrev ){

  79732.     p->pPrev->pNext = p->pNext;

  79733.   }else{

  79734.     assert( db->pVdbe==p );

  79735.     db->pVdbe = p->pNext;

  79736.   }

  79737.   if( p->pNext ){

  79738.     p->pNext->pPrev = p->pPrev;

  79739.   }

  79740.   p->magic = VDBE_MAGIC_DEAD;

  79741.   p->db = 0;

  79742.   sqlite3DbFreeNN(db, p);

  79743. }

  79744. 

  79745. /*

  79746. ** The cursor "p" has a pending seek operation that has not yet been

  79747. ** carried out.  Seek the cursor now.  If an error occurs, return

  79748. ** the appropriate error code.

  79749. */

  79750. static int SQLITE_NOINLINE handleDeferredMoveto(VdbeCursor *p){

  79751.   int res, rc;

  79752. #ifdef SQLITE_TEST

  79753.   extern int sqlite3_search_count;

  79754. #endif

  79755.   assert( p->deferredMoveto );

  79756.   assert( p->isTable );

  79757.   assert( p->eCurType==CURTYPE_BTREE );

  79758.   rc = sqlite3BtreeMovetoUnpacked(p->uc.pCursor, 0, p->movetoTarget, 0, &res);

  79759.   if( rc ) return rc;

  79760.   if( res!=0 ) return SQLITE_CORRUPT_BKPT;

  79761. #ifdef SQLITE_TEST

  79762.   sqlite3_search_count++;

  79763. #endif

  79764.   p->deferredMoveto = 0;

  79765.   p->cacheStatus = CACHE_STALE;

  79766.   return SQLITE_OK;

  79767. }

  79768. 

  79769. /*

  79770. ** Something has moved cursor "p" out of place.  Maybe the row it was

  79771. ** pointed to was deleted out from under it.  Or maybe the btree was

  79772. ** rebalanced.  Whatever the cause, try to restore "p" to the place it

  79773. ** is supposed to be pointing.  If the row was deleted out from under the

  79774. ** cursor, set the cursor to point to a NULL row.

  79775. */

  79776. static int SQLITE_NOINLINE handleMovedCursor(VdbeCursor *p){

  79777.   int isDifferentRow, rc;

  79778.   assert( p->eCurType==CURTYPE_BTREE );

  79779.   assert( p->uc.pCursor!=0 );

  79780.   assert( sqlite3BtreeCursorHasMoved(p->uc.pCursor) );

  79781.   rc = sqlite3BtreeCursorRestore(p->uc.pCursor, &isDifferentRow);

  79782.   p->cacheStatus = CACHE_STALE;

  79783.   if( isDifferentRow ) p->nullRow = 1;

  79784.   return rc;

  79785. }

  79786. 

  79787. /*

  79788. ** Check to ensure that the cursor is valid.  Restore the cursor

  79789. ** if need be.  Return any I/O error from the restore operation.

  79790. */

  79791. SQLITE_PRIVATE int sqlite3VdbeCursorRestore(VdbeCursor *p){

  79792.   assert( p->eCurType==CURTYPE_BTREE );

  79793.   if( sqlite3BtreeCursorHasMoved(p->uc.pCursor) ){

  79794.     return handleMovedCursor(p);

  79795.   }

  79796.   return SQLITE_OK;

  79797. }

  79798. 

  79799. /*

  79800. ** Make sure the cursor p is ready to read or write the row to which it

  79801. ** was last positioned.  Return an error code if an OOM fault or I/O error

  79802. ** prevents us from positioning the cursor to its correct position.

  79803. **

  79804. ** If a MoveTo operation is pending on the given cursor, then do that

  79805. ** MoveTo now.  If no move is pending, check to see if the row has been

  79806. ** deleted out from under the cursor and if it has, mark the row as

  79807. ** a NULL row.

  79808. **

  79809. ** If the cursor is already pointing to the correct row and that row has

  79810. ** not been deleted out from under the cursor, then this routine is a no-op.

  79811. */

  79812. SQLITE_PRIVATE int sqlite3VdbeCursorMoveto(VdbeCursor **pp, int *piCol){

  79813.   VdbeCursor *p = *pp;

  79814.   assert( p->eCurType==CURTYPE_BTREE || p->eCurType==CURTYPE_PSEUDO );

  79815.   if( p->deferredMoveto ){

  79816.     int iMap;

  79817.     if( p->aAltMap && (iMap = p->aAltMap[1+*piCol])>0 ){

  79818.       *pp = p->pAltCursor;

  79819.       *piCol = iMap - 1;

  79820.       return SQLITE_OK;

  79821.     }

  79822.     return handleDeferredMoveto(p);

  79823.   }

  79824.   if( sqlite3BtreeCursorHasMoved(p->uc.pCursor) ){

  79825.     return handleMovedCursor(p);

  79826.   }

  79827.   return SQLITE_OK;

  79828. }

  79829. 

  79830. /*

  79831. ** The following functions:

  79832. **

  79833. ** sqlite3VdbeSerialType()

  79834. ** sqlite3VdbeSerialTypeLen()

  79835. ** sqlite3VdbeSerialLen()

  79836. ** sqlite3VdbeSerialPut()

  79837. ** sqlite3VdbeSerialGet()

  79838. **

  79839. ** encapsulate the code that serializes values for storage in SQLite

  79840. ** data and index records. Each serialized value consists of a

  79841. ** 'serial-type' and a blob of data. The serial type is an 8-byte unsigned

  79842. ** integer, stored as a varint.

  79843. **

  79844. ** In an SQLite index record, the serial type is stored directly before

  79845. ** the blob of data that it corresponds to. In a table record, all serial

  79846. ** types are stored at the start of the record, and the blobs of data at

  79847. ** the end. Hence these functions allow the caller to handle the

  79848. ** serial-type and data blob separately.

  79849. **

  79850. ** The following table describes the various storage classes for data:

  79851. **

  79852. **   serial type        bytes of data      type

  79853. **   --------------     ---------------    ---------------

  79854. **      0                     0            NULL

  79855. **      1                     1            signed integer

  79856. **      2                     2            signed integer

  79857. **      3                     3            signed integer

  79858. **      4                     4            signed integer

  79859. **      5                     6            signed integer

  79860. **      6                     8            signed integer

  79861. **      7                     8            IEEE float

  79862. **      8                     0            Integer constant 0

  79863. **      9                     0            Integer constant 1

  79864. **     10,11                               reserved for expansion

  79865. **    N>=12 and even       (N-12)/2        BLOB

  79866. **    N>=13 and odd        (N-13)/2        text

  79867. **

  79868. ** The 8 and 9 types were added in 3.3.0, file format 4.  Prior versions

  79869. ** of SQLite will not understand those serial types.

  79870. */

  79871. 

  79872. /*

  79873. ** Return the serial-type for the value stored in pMem.

  79874. **

  79875. ** This routine might convert a large MEM_IntReal value into MEM_Real.

  79876. */

  79877. SQLITE_PRIVATE u32 sqlite3VdbeSerialType(Mem *pMem, int file_format, u32 *pLen){

  79878.   int flags = pMem->flags;

  79879.   u32 n;

  79880. 

  79881.   assert( pLen!=0 );

  79882.   if( flags&MEM_Null ){

  79883.     *pLen = 0;

  79884.     return 0;

  79885.   }

  79886.   if( flags&(MEM_Int|MEM_IntReal) ){

  79887.     /* Figure out whether to use 1, 2, 4, 6 or 8 bytes. */

  79888. #   define MAX_6BYTE ((((i64)0x00008000)<<32)-1)

  79889.     i64 i = pMem->u.i;

  79890.     u64 u;

  79891.     testcase( flags & MEM_Int );

  79892.     testcase( flags & MEM_IntReal );

  79893.     if( i<0 ){

  79894.       u = ~i;

  79895.     }else{

  79896.       u = i;

  79897.     }

  79898.     if( u<=127 ){

  79899.       if( (i&1)==i && file_format>=4 ){

  79900.         *pLen = 0;

  79901.         return 8+(u32)u;

  79902.       }else{

  79903.         *pLen = 1;

  79904.         return 1;

  79905.       }

  79906.     }

  79907.     if( u<=32767 ){ *pLen = 2; return 2; }

  79908.     if( u<=8388607 ){ *pLen = 3; return 3; }

  79909.     if( u<=2147483647 ){ *pLen = 4; return 4; }

  79910.     if( u<=MAX_6BYTE ){ *pLen = 6; return 5; }

  79911.     *pLen = 8;

  79912.     if( flags&MEM_IntReal ){

  79913.       /* If the value is IntReal and is going to take up 8 bytes to store

  79914.       ** as an integer, then we might as well make it an 8-byte floating

  79915.       ** point value */

  79916.       pMem->u.r = (double)pMem->u.i;

  79917.       pMem->flags &= ~MEM_IntReal;

  79918.       pMem->flags |= MEM_Real;

  79919.       return 7;

  79920.     }

  79921.     return 6;

  79922.   }

  79923.   if( flags&MEM_Real ){

  79924.     *pLen = 8;

  79925.     return 7;

  79926.   }

  79927.   assert( pMem->db->mallocFailed || flags&(MEM_Str|MEM_Blob) );

  79928.   assert( pMem->n>=0 );

  79929.   n = (u32)pMem->n;

  79930.   if( flags & MEM_Zero ){

  79931.     n += pMem->u.nZero;

  79932.   }

  79933.   *pLen = n;

  79934.   return ((n*2) + 12 + ((flags&MEM_Str)!=0));

  79935. }

  79936. 

  79937. /*

  79938. ** The sizes for serial types less than 128

  79939. */

  79940. static const u8 sqlite3SmallTypeSizes[] = {

  79941.         /*  0   1   2   3   4   5   6   7   8   9 */   

  79942. /*   0 */   0,  1,  2,  3,  4,  6,  8,  8,  0,  0,

  79943. /*  10 */   0,  0,  0,  0,  1,  1,  2,  2,  3,  3,

  79944. /*  20 */   4,  4,  5,  5,  6,  6,  7,  7,  8,  8,

  79945. /*  30 */   9,  9, 10, 10, 11, 11, 12, 12, 13, 13,

  79946. /*  40 */  14, 14, 15, 15, 16, 16, 17, 17, 18, 18,

  79947. /*  50 */  19, 19, 20, 20, 21, 21, 22, 22, 23, 23,

  79948. /*  60 */  24, 24, 25, 25, 26, 26, 27, 27, 28, 28,

  79949. /*  70 */  29, 29, 30, 30, 31, 31, 32, 32, 33, 33,

  79950. /*  80 */  34, 34, 35, 35, 36, 36, 37, 37, 38, 38,

  79951. /*  90 */  39, 39, 40, 40, 41, 41, 42, 42, 43, 43,

  79952. /* 100 */  44, 44, 45, 45, 46, 46, 47, 47, 48, 48,

  79953. /* 110 */  49, 49, 50, 50, 51, 51, 52, 52, 53, 53,

  79954. /* 120 */  54, 54, 55, 55, 56, 56, 57, 57

  79955. };

  79956. 

  79957. /*

  79958. ** Return the length of the data corresponding to the supplied serial-type.

  79959. */

  79960. SQLITE_PRIVATE u32 sqlite3VdbeSerialTypeLen(u32 serial_type){

  79961.   if( serial_type>=128 ){

  79962.     return (serial_type-12)/2;

  79963.   }else{

  79964.     assert( serial_type<12 

  79965.             || sqlite3SmallTypeSizes[serial_type]==(serial_type - 12)/2 );

  79966.     return sqlite3SmallTypeSizes[serial_type];

  79967.   }

  79968. }

  79969. SQLITE_PRIVATE u8 sqlite3VdbeOneByteSerialTypeLen(u8 serial_type){

  79970.   assert( serial_type<128 );

  79971.   return sqlite3SmallTypeSizes[serial_type];  

  79972. }

  79973. 

  79974. /*

  79975. ** If we are on an architecture with mixed-endian floating 

  79976. ** points (ex: ARM7) then swap the lower 4 bytes with the 

  79977. ** upper 4 bytes.  Return the result.

  79978. **

  79979. ** For most architectures, this is a no-op.

  79980. **

  79981. ** (later):  It is reported to me that the mixed-endian problem

  79982. ** on ARM7 is an issue with GCC, not with the ARM7 chip.  It seems

  79983. ** that early versions of GCC stored the two words of a 64-bit

  79984. ** float in the wrong order.  And that error has been propagated

  79985. ** ever since.  The blame is not necessarily with GCC, though.

  79986. ** GCC might have just copying the problem from a prior compiler.

  79987. ** I am also told that newer versions of GCC that follow a different

  79988. ** ABI get the byte order right.

  79989. **

  79990. ** Developers using SQLite on an ARM7 should compile and run their

  79991. ** application using -DSQLITE_DEBUG=1 at least once.  With DEBUG

  79992. ** enabled, some asserts below will ensure that the byte order of

  79993. ** floating point values is correct.

  79994. **

  79995. ** (2007-08-30)  Frank van Vugt has studied this problem closely

  79996. ** and has send his findings to the SQLite developers.  Frank

  79997. ** writes that some Linux kernels offer floating point hardware

  79998. ** emulation that uses only 32-bit mantissas instead of a full 

  79999. ** 48-bits as required by the IEEE standard.  (This is the

  80000. ** CONFIG_FPE_FASTFPE option.)  On such systems, floating point

  80001. ** byte swapping becomes very complicated.  To avoid problems,

  80002. ** the necessary byte swapping is carried out using a 64-bit integer

  80003. ** rather than a 64-bit float.  Frank assures us that the code here

  80004. ** works for him.  We, the developers, have no way to independently

  80005. ** verify this, but Frank seems to know what he is talking about

  80006. ** so we trust him.

  80007. */

  80008. #ifdef SQLITE_MIXED_ENDIAN_64BIT_FLOAT

  80009. static u64 floatSwap(u64 in){

  80010.   union {

  80011.     u64 r;

  80012.     u32 i[2];

  80013.   } u;

  80014.   u32 t;

  80015. 

  80016.   u.r = in;

  80017.   t = u.i[0];

  80018.   u.i[0] = u.i[1];

  80019.   u.i[1] = t;

  80020.   return u.r;

  80021. }

  80022. # define swapMixedEndianFloat(X)  X = floatSwap(X)

  80023. #else

  80024. # define swapMixedEndianFloat(X)

  80025. #endif

  80026. 

  80027. /*

  80028. ** Write the serialized data blob for the value stored in pMem into 

  80029. ** buf. It is assumed that the caller has allocated sufficient space.

  80030. ** Return the number of bytes written.

  80031. **

  80032. ** nBuf is the amount of space left in buf[].  The caller is responsible

  80033. ** for allocating enough space to buf[] to hold the entire field, exclusive

  80034. ** of the pMem->u.nZero bytes for a MEM_Zero value.

  80035. **

  80036. ** Return the number of bytes actually written into buf[].  The number

  80037. ** of bytes in the zero-filled tail is included in the return value only

  80038. ** if those bytes were zeroed in buf[].

  80039. */ 

  80040. SQLITE_PRIVATE u32 sqlite3VdbeSerialPut(u8 *buf, Mem *pMem, u32 serial_type){

  80041.   u32 len;

  80042. 

  80043.   /* Integer and Real */

  80044.   if( serial_type<=7 && serial_type>0 ){

  80045.     u64 v;

  80046.     u32 i;

  80047.     if( serial_type==7 ){

  80048.       assert( sizeof(v)==sizeof(pMem->u.r) );

  80049.       memcpy(&v, &pMem->u.r, sizeof(v));

  80050.       swapMixedEndianFloat(v);

  80051.     }else{

  80052.       v = pMem->u.i;

  80053.     }

  80054.     len = i = sqlite3SmallTypeSizes[serial_type];

  80055.     assert( i>0 );

  80056.     do{

  80057.       buf[--i] = (u8)(v&0xFF);

  80058.       v >>= 8;

  80059.     }while( i );

  80060.     return len;

  80061.   }

  80062. 

  80063.   /* String or blob */

  80064.   if( serial_type>=12 ){

  80065.     assert( pMem->n + ((pMem->flags & MEM_Zero)?pMem->u.nZero:0)

  80066.              == (int)sqlite3VdbeSerialTypeLen(serial_type) );

  80067.     len = pMem->n;

  80068.     if( len>0 ) memcpy(buf, pMem->z, len);

  80069.     return len;

  80070.   }

  80071. 

  80072.   /* NULL or constants 0 or 1 */

  80073.   return 0;

  80074. }

  80075. 

  80076. /* Input "x" is a sequence of unsigned characters that represent a

  80077. ** big-endian integer.  Return the equivalent native integer

  80078. */

  80079. #define ONE_BYTE_INT(x)    ((i8)(x)[0])

  80080. #define TWO_BYTE_INT(x)    (256*(i8)((x)[0])|(x)[1])

  80081. #define THREE_BYTE_INT(x)  (65536*(i8)((x)[0])|((x)[1]<<8)|(x)[2])

  80082. #define FOUR_BYTE_UINT(x)  (((u32)(x)[0]<<24)|((x)[1]<<16)|((x)[2]<<8)|(x)[3])

  80083. #define FOUR_BYTE_INT(x) (16777216*(i8)((x)[0])|((x)[1]<<16)|((x)[2]<<8)|(x)[3])

  80084. 

  80085. /*

  80086. ** Deserialize the data blob pointed to by buf as serial type serial_type

  80087. ** and store the result in pMem.  Return the number of bytes read.

  80088. **

  80089. ** This function is implemented as two separate routines for performance.

  80090. ** The few cases that require local variables are broken out into a separate

  80091. ** routine so that in most cases the overhead of moving the stack pointer

  80092. ** is avoided.

  80093. */ 

  80094. static u32 serialGet(

  80095.   const unsigned char *buf,     /* Buffer to deserialize from */

  80096.   u32 serial_type,              /* Serial type to deserialize */

  80097.   Mem *pMem                     /* Memory cell to write value into */

  80098. ){

  80099.   u64 x = FOUR_BYTE_UINT(buf);

  80100.   u32 y = FOUR_BYTE_UINT(buf+4);

  80101.   x = (x<<32) + y;

  80102.   if( serial_type==6 ){

  80103.     /* EVIDENCE-OF: R-29851-52272 Value is a big-endian 64-bit

  80104.     ** twos-complement integer. */

  80105.     pMem->u.i = *(i64*)&x;

  80106.     pMem->flags = MEM_Int;

  80107.     testcase( pMem->u.i<0 );

  80108.   }else{

  80109.     /* EVIDENCE-OF: R-57343-49114 Value is a big-endian IEEE 754-2008 64-bit

  80110.     ** floating point number. */

  80111. #if !defined(NDEBUG) && !defined(SQLITE_OMIT_FLOATING_POINT)

  80112.     /* Verify that integers and floating point values use the same

  80113.     ** byte order.  Or, that if SQLITE_MIXED_ENDIAN_64BIT_FLOAT is

  80114.     ** defined that 64-bit floating point values really are mixed

  80115.     ** endian.

  80116.     */

  80117.     static const u64 t1 = ((u64)0x3ff00000)<<32;

  80118.     static const double r1 = 1.0;

  80119.     u64 t2 = t1;

  80120.     swapMixedEndianFloat(t2);

  80121.     assert( sizeof(r1)==sizeof(t2) && memcmp(&r1, &t2, sizeof(r1))==0 );

  80122. #endif

  80123.     assert( sizeof(x)==8 && sizeof(pMem->u.r)==8 );

  80124.     swapMixedEndianFloat(x);

  80125.     memcpy(&pMem->u.r, &x, sizeof(x));

  80126.     pMem->flags = IsNaN(x) ? MEM_Null : MEM_Real;

  80127.   }

  80128.   return 8;

  80129. }

  80130. SQLITE_PRIVATE u32 sqlite3VdbeSerialGet(

  80131.   const unsigned char *buf,     /* Buffer to deserialize from */

  80132.   u32 serial_type,              /* Serial type to deserialize */

  80133.   Mem *pMem                     /* Memory cell to write value into */

  80134. ){

  80135.   switch( serial_type ){

  80136.     case 10: { /* Internal use only: NULL with virtual table

  80137.                ** UPDATE no-change flag set */

  80138.       pMem->flags = MEM_Null|MEM_Zero;

  80139.       pMem->n = 0;

  80140.       pMem->u.nZero = 0;

  80141.       break;

  80142.     }

  80143.     case 11:   /* Reserved for future use */

  80144.     case 0: {  /* Null */

  80145.       /* EVIDENCE-OF: R-24078-09375 Value is a NULL. */

  80146.       pMem->flags = MEM_Null;

  80147.       break;

  80148.     }

  80149.     case 1: {

  80150.       /* EVIDENCE-OF: R-44885-25196 Value is an 8-bit twos-complement

  80151.       ** integer. */

  80152.       pMem->u.i = ONE_BYTE_INT(buf);

  80153.       pMem->flags = MEM_Int;

  80154.       testcase( pMem->u.i<0 );

  80155.       return 1;

  80156.     }

  80157.     case 2: { /* 2-byte signed integer */

  80158.       /* EVIDENCE-OF: R-49794-35026 Value is a big-endian 16-bit

  80159.       ** twos-complement integer. */

  80160.       pMem->u.i = TWO_BYTE_INT(buf);

  80161.       pMem->flags = MEM_Int;

  80162.       testcase( pMem->u.i<0 );

  80163.       return 2;

  80164.     }

  80165.     case 3: { /* 3-byte signed integer */

  80166.       /* EVIDENCE-OF: R-37839-54301 Value is a big-endian 24-bit

  80167.       ** twos-complement integer. */

  80168.       pMem->u.i = THREE_BYTE_INT(buf);

  80169.       pMem->flags = MEM_Int;

  80170.       testcase( pMem->u.i<0 );

  80171.       return 3;

  80172.     }

  80173.     case 4: { /* 4-byte signed integer */

  80174.       /* EVIDENCE-OF: R-01849-26079 Value is a big-endian 32-bit

  80175.       ** twos-complement integer. */

  80176.       pMem->u.i = FOUR_BYTE_INT(buf);

  80177. #ifdef __HP_cc 

  80178.       /* Work around a sign-extension bug in the HP compiler for HP/UX */

  80179.       if( buf[0]&0x80 ) pMem->u.i |= 0xffffffff80000000LL;

  80180. #endif

  80181.       pMem->flags = MEM_Int;

  80182.       testcase( pMem->u.i<0 );

  80183.       return 4;

  80184.     }

  80185.     case 5: { /* 6-byte signed integer */

  80186.       /* EVIDENCE-OF: R-50385-09674 Value is a big-endian 48-bit

  80187.       ** twos-complement integer. */

  80188.       pMem->u.i = FOUR_BYTE_UINT(buf+2) + (((i64)1)<<32)*TWO_BYTE_INT(buf);

  80189.       pMem->flags = MEM_Int;

  80190.       testcase( pMem->u.i<0 );

  80191.       return 6;

  80192.     }

  80193.     case 6:   /* 8-byte signed integer */

  80194.     case 7: { /* IEEE floating point */

  80195.       /* These use local variables, so do them in a separate routine

  80196.       ** to avoid having to move the frame pointer in the common case */

  80197.       return serialGet(buf,serial_type,pMem);

  80198.     }

  80199.     case 8:    /* Integer 0 */

  80200.     case 9: {  /* Integer 1 */

  80201.       /* EVIDENCE-OF: R-12976-22893 Value is the integer 0. */

  80202.       /* EVIDENCE-OF: R-18143-12121 Value is the integer 1. */

  80203.       pMem->u.i = serial_type-8;

  80204.       pMem->flags = MEM_Int;

  80205.       return 0;

  80206.     }

  80207.     default: {

  80208.       /* EVIDENCE-OF: R-14606-31564 Value is a BLOB that is (N-12)/2 bytes in

  80209.       ** length.

  80210.       ** EVIDENCE-OF: R-28401-00140 Value is a string in the text encoding and

  80211.       ** (N-13)/2 bytes in length. */

  80212.       static const u16 aFlag[] = { MEM_Blob|MEM_Ephem, MEM_Str|MEM_Ephem };

  80213.       pMem->z = (char *)buf;

  80214.       pMem->n = (serial_type-12)/2;

  80215.       pMem->flags = aFlag[serial_type&1];

  80216.       return pMem->n;

  80217.     }

  80218.   }

  80219.   return 0;

  80220. }

  80221. /*

  80222. ** This routine is used to allocate sufficient space for an UnpackedRecord

  80223. ** structure large enough to be used with sqlite3VdbeRecordUnpack() if

  80224. ** the first argument is a pointer to KeyInfo structure pKeyInfo.

  80225. **

  80226. ** The space is either allocated using sqlite3DbMallocRaw() or from within

  80227. ** the unaligned buffer passed via the second and third arguments (presumably

  80228. ** stack space). If the former, then *ppFree is set to a pointer that should

  80229. ** be eventually freed by the caller using sqlite3DbFree(). Or, if the 

  80230. ** allocation comes from the pSpace/szSpace buffer, *ppFree is set to NULL

  80231. ** before returning.

  80232. **

  80233. ** If an OOM error occurs, NULL is returned.

  80234. */

  80235. SQLITE_PRIVATE UnpackedRecord *sqlite3VdbeAllocUnpackedRecord(

  80236.   KeyInfo *pKeyInfo               /* Description of the record */

  80237. ){

  80238.   UnpackedRecord *p;              /* Unpacked record to return */

  80239.   int nByte;                      /* Number of bytes required for *p */

  80240.   nByte = ROUND8(sizeof(UnpackedRecord)) + sizeof(Mem)*(pKeyInfo->nKeyField+1);

  80241.   p = (UnpackedRecord *)sqlite3DbMallocRaw(pKeyInfo->db, nByte);

  80242.   if( !p ) return 0;

  80243.   p->aMem = (Mem*)&((char*)p)[ROUND8(sizeof(UnpackedRecord))];

  80244.   assert( pKeyInfo->aSortOrder!=0 );

  80245.   p->pKeyInfo = pKeyInfo;

  80246.   p->nField = pKeyInfo->nKeyField + 1;

  80247.   return p;

  80248. }

  80249. 

  80250. /*

  80251. ** Given the nKey-byte encoding of a record in pKey[], populate the 

  80252. ** UnpackedRecord structure indicated by the fourth argument with the

  80253. ** contents of the decoded record.

  80254. */ 

  80255. SQLITE_PRIVATE void sqlite3VdbeRecordUnpack(

  80256.   KeyInfo *pKeyInfo,     /* Information about the record format */

  80257.   int nKey,              /* Size of the binary record */

  80258.   const void *pKey,      /* The binary record */

  80259.   UnpackedRecord *p      /* Populate this structure before returning. */

  80260. ){

  80261.   const unsigned char *aKey = (const unsigned char *)pKey;

  80262.   u32 d; 

  80263.   u32 idx;                        /* Offset in aKey[] to read from */

  80264.   u16 u;                          /* Unsigned loop counter */

  80265.   u32 szHdr;

  80266.   Mem *pMem = p->aMem;

  80267. 

  80268.   p->default_rc = 0;

  80269.   assert( EIGHT_BYTE_ALIGNMENT(pMem) );

  80270.   idx = getVarint32(aKey, szHdr);

  80271.   d = szHdr;

  80272.   u = 0;

  80273.   while( idx<szHdr && d<=(u32)nKey ){

  80274.     u32 serial_type;

  80275. 

  80276.     idx += getVarint32(&aKey[idx], serial_type);

  80277.     pMem->enc = pKeyInfo->enc;

  80278.     pMem->db = pKeyInfo->db;

  80279.     /* pMem->flags = 0; // sqlite3VdbeSerialGet() will set this for us */

  80280.     pMem->szMalloc = 0;

  80281.     pMem->z = 0;

  80282.     d += sqlite3VdbeSerialGet(&aKey[d], serial_type, pMem);

  80283.     pMem++;

  80284.     if( (++u)>=p->nField ) break;

  80285.   }

  80286.   if( d>(u32)nKey && u ){

  80287.     assert( CORRUPT_DB );

  80288.     /* In a corrupt record entry, the last pMem might have been set up using 

  80289.     ** uninitialized memory. Overwrite its value with NULL, to prevent

  80290.     ** warnings from MSAN. */

  80291.     sqlite3VdbeMemSetNull(pMem-1);

  80292.   }

  80293.   assert( u<=pKeyInfo->nKeyField + 1 );

  80294.   p->nField = u;

  80295. }

  80296. 

  80297. #ifdef SQLITE_DEBUG

  80298. /*

  80299. ** This function compares two index or table record keys in the same way

  80300. ** as the sqlite3VdbeRecordCompare() routine. Unlike VdbeRecordCompare(),

  80301. ** this function deserializes and compares values using the

  80302. ** sqlite3VdbeSerialGet() and sqlite3MemCompare() functions. It is used

  80303. ** in assert() statements to ensure that the optimized code in

  80304. ** sqlite3VdbeRecordCompare() returns results with these two primitives.

  80305. **

  80306. ** Return true if the result of comparison is equivalent to desiredResult.

  80307. ** Return false if there is a disagreement.

  80308. */

  80309. static int vdbeRecordCompareDebug(

  80310.   int nKey1, const void *pKey1, /* Left key */

  80311.   const UnpackedRecord *pPKey2, /* Right key */

  80312.   int desiredResult             /* Correct answer */

  80313. ){

  80314.   u32 d1;            /* Offset into aKey[] of next data element */

  80315.   u32 idx1;          /* Offset into aKey[] of next header element */

  80316.   u32 szHdr1;        /* Number of bytes in header */

  80317.   int i = 0;

  80318.   int rc = 0;

  80319.   const unsigned char *aKey1 = (const unsigned char *)pKey1;

  80320.   KeyInfo *pKeyInfo;

  80321.   Mem mem1;

  80322. 

  80323.   pKeyInfo = pPKey2->pKeyInfo;

  80324.   if( pKeyInfo->db==0 ) return 1;

  80325.   mem1.enc = pKeyInfo->enc;

  80326.   mem1.db = pKeyInfo->db;

  80327.   /* mem1.flags = 0;  // Will be initialized by sqlite3VdbeSerialGet() */

  80328.   VVA_ONLY( mem1.szMalloc = 0; ) /* Only needed by assert() statements */

  80329. 

  80330.   /* Compilers may complain that mem1.u.i is potentially uninitialized.

  80331.   ** We could initialize it, as shown here, to silence those complaints.

  80332.   ** But in fact, mem1.u.i will never actually be used uninitialized, and doing 

  80333.   ** the unnecessary initialization has a measurable negative performance

  80334.   ** impact, since this routine is a very high runner.  And so, we choose

  80335.   ** to ignore the compiler warnings and leave this variable uninitialized.

  80336.   */

  80337.   /*  mem1.u.i = 0;  // not needed, here to silence compiler warning */

  80338.   

  80339.   idx1 = getVarint32(aKey1, szHdr1);

  80340.   if( szHdr1>98307 ) return SQLITE_CORRUPT;

  80341.   d1 = szHdr1;

  80342.   assert( pKeyInfo->nAllField>=pPKey2->nField || CORRUPT_DB );

  80343.   assert( pKeyInfo->aSortOrder!=0 );

  80344.   assert( pKeyInfo->nKeyField>0 );

  80345.   assert( idx1<=szHdr1 || CORRUPT_DB );

  80346.   do{

  80347.     u32 serial_type1;

  80348. 

  80349.     /* Read the serial types for the next element in each key. */

  80350.     idx1 += getVarint32( aKey1+idx1, serial_type1 );

  80351. 

  80352.     /* Verify that there is enough key space remaining to avoid

  80353.     ** a buffer overread.  The "d1+serial_type1+2" subexpression will

  80354.     ** always be greater than or equal to the amount of required key space.

  80355.     ** Use that approximation to avoid the more expensive call to

  80356.     ** sqlite3VdbeSerialTypeLen() in the common case.

  80357.     */

  80358.     if( d1+(u64)serial_type1+2>(u64)nKey1

  80359.      && d1+(u64)sqlite3VdbeSerialTypeLen(serial_type1)>(u64)nKey1 

  80360.     ){

  80361.       break;

  80362.     }

  80363. 

  80364.     /* Extract the values to be compared.

  80365.     */

  80366.     d1 += sqlite3VdbeSerialGet(&aKey1[d1], serial_type1, &mem1);

  80367. 

  80368.     /* Do the comparison

  80369.     */

  80370.     rc = sqlite3MemCompare(&mem1, &pPKey2->aMem[i],

  80371.                            pKeyInfo->nAllField>i ? pKeyInfo->aColl[i] : 0);

  80372.     if( rc!=0 ){

  80373.       assert( mem1.szMalloc==0 );  /* See comment below */

  80374.       if( pKeyInfo->aSortOrder[i] ){

  80375.         rc = -rc;  /* Invert the result for DESC sort order. */

  80376.       }

  80377.       goto debugCompareEnd;

  80378.     }

  80379.     i++;

  80380.   }while( idx1<szHdr1 && i<pPKey2->nField );

  80381. 

  80382.   /* No memory allocation is ever used on mem1.  Prove this using

  80383.   ** the following assert().  If the assert() fails, it indicates a

  80384.   ** memory leak and a need to call sqlite3VdbeMemRelease(&mem1).

  80385.   */

  80386.   assert( mem1.szMalloc==0 );

  80387. 

  80388.   /* rc==0 here means that one of the keys ran out of fields and

  80389.   ** all the fields up to that point were equal. Return the default_rc

  80390.   ** value.  */

  80391.   rc = pPKey2->default_rc;

  80392. 

  80393. debugCompareEnd:

  80394.   if( desiredResult==0 && rc==0 ) return 1;

  80395.   if( desiredResult<0 && rc<0 ) return 1;

  80396.   if( desiredResult>0 && rc>0 ) return 1;

  80397.   if( CORRUPT_DB ) return 1;

  80398.   if( pKeyInfo->db->mallocFailed ) return 1;

  80399.   return 0;

  80400. }

  80401. #endif

  80402. 

  80403. #ifdef SQLITE_DEBUG

  80404. /*

  80405. ** Count the number of fields (a.k.a. columns) in the record given by

  80406. ** pKey,nKey.  The verify that this count is less than or equal to the

  80407. ** limit given by pKeyInfo->nAllField.

  80408. **

  80409. ** If this constraint is not satisfied, it means that the high-speed

  80410. ** vdbeRecordCompareInt() and vdbeRecordCompareString() routines will

  80411. ** not work correctly.  If this assert() ever fires, it probably means

  80412. ** that the KeyInfo.nKeyField or KeyInfo.nAllField values were computed

  80413. ** incorrectly.

  80414. */

  80415. static void vdbeAssertFieldCountWithinLimits(

  80416.   int nKey, const void *pKey,   /* The record to verify */ 

  80417.   const KeyInfo *pKeyInfo       /* Compare size with this KeyInfo */

  80418. ){

  80419.   int nField = 0;

  80420.   u32 szHdr;

  80421.   u32 idx;

  80422.   u32 notUsed;

  80423.   const unsigned char *aKey = (const unsigned char*)pKey;

  80424. 

  80425.   if( CORRUPT_DB ) return;

  80426.   idx = getVarint32(aKey, szHdr);

  80427.   assert( nKey>=0 );

  80428.   assert( szHdr<=(u32)nKey );

  80429.   while( idx<szHdr ){

  80430.     idx += getVarint32(aKey+idx, notUsed);

  80431.     nField++;

  80432.   }

  80433.   assert( nField <= pKeyInfo->nAllField );

  80434. }

  80435. #else

  80436. # define vdbeAssertFieldCountWithinLimits(A,B,C)

  80437. #endif

  80438. 

  80439. /*

  80440. ** Both *pMem1 and *pMem2 contain string values. Compare the two values

  80441. ** using the collation sequence pColl. As usual, return a negative , zero

  80442. ** or positive value if *pMem1 is less than, equal to or greater than 

  80443. ** *pMem2, respectively. Similar in spirit to "rc = (*pMem1) - (*pMem2);".

  80444. */

  80445. static int vdbeCompareMemString(

  80446.   const Mem *pMem1,

  80447.   const Mem *pMem2,

  80448.   const CollSeq *pColl,

  80449.   u8 *prcErr                      /* If an OOM occurs, set to SQLITE_NOMEM */

  80450. ){

  80451.   if( pMem1->enc==pColl->enc ){

  80452.     /* The strings are already in the correct encoding.  Call the

  80453.      ** comparison function directly */

  80454.     return pColl->xCmp(pColl->pUser,pMem1->n,pMem1->z,pMem2->n,pMem2->z);

  80455.   }else{

  80456.     int rc;

  80457.     const void *v1, *v2;

  80458.     Mem c1;

  80459.     Mem c2;

  80460.     sqlite3VdbeMemInit(&c1, pMem1->db, MEM_Null);

  80461.     sqlite3VdbeMemInit(&c2, pMem1->db, MEM_Null);

  80462.     sqlite3VdbeMemShallowCopy(&c1, pMem1, MEM_Ephem);

  80463.     sqlite3VdbeMemShallowCopy(&c2, pMem2, MEM_Ephem);

  80464.     v1 = sqlite3ValueText((sqlite3_value*)&c1, pColl->enc);

  80465.     v2 = sqlite3ValueText((sqlite3_value*)&c2, pColl->enc);

  80466.     if( (v1==0 || v2==0) ){

  80467.       if( prcErr ) *prcErr = SQLITE_NOMEM_BKPT;

  80468.       rc = 0;

  80469.     }else{

  80470.       rc = pColl->xCmp(pColl->pUser, c1.n, v1, c2.n, v2);

  80471.     }

  80472.     sqlite3VdbeMemRelease(&c1);

  80473.     sqlite3VdbeMemRelease(&c2);

  80474.     return rc;

  80475.   }

  80476. }

  80477. 

  80478. /*

  80479. ** The input pBlob is guaranteed to be a Blob that is not marked

  80480. ** with MEM_Zero.  Return true if it could be a zero-blob.

  80481. */

  80482. static int isAllZero(const char *z, int n){

  80483.   int i;

  80484.   for(i=0; i<n; i++){

  80485.     if( z[i] ) return 0;

  80486.   }

  80487.   return 1;

  80488. }

  80489. 

  80490. /*

  80491. ** Compare two blobs.  Return negative, zero, or positive if the first

  80492. ** is less than, equal to, or greater than the second, respectively.

  80493. ** If one blob is a prefix of the other, then the shorter is the lessor.

  80494. */

  80495. SQLITE_PRIVATE SQLITE_NOINLINE int sqlite3BlobCompare(const Mem *pB1, const Mem *pB2){

  80496.   int c;

  80497.   int n1 = pB1->n;

  80498.   int n2 = pB2->n;

  80499. 

  80500.   /* It is possible to have a Blob value that has some non-zero content

  80501.   ** followed by zero content.  But that only comes up for Blobs formed

  80502.   ** by the OP_MakeRecord opcode, and such Blobs never get passed into

  80503.   ** sqlite3MemCompare(). */

  80504.   assert( (pB1->flags & MEM_Zero)==0 || n1==0 );

  80505.   assert( (pB2->flags & MEM_Zero)==0 || n2==0 );

  80506. 

  80507.   if( (pB1->flags|pB2->flags) & MEM_Zero ){

  80508.     if( pB1->flags & pB2->flags & MEM_Zero ){

  80509.       return pB1->u.nZero - pB2->u.nZero;

  80510.     }else if( pB1->flags & MEM_Zero ){

  80511.       if( !isAllZero(pB2->z, pB2->n) ) return -1;

  80512.       return pB1->u.nZero - n2;

  80513.     }else{

  80514.       if( !isAllZero(pB1->z, pB1->n) ) return +1;

  80515.       return n1 - pB2->u.nZero;

  80516.     }

  80517.   }

  80518.   c = memcmp(pB1->z, pB2->z, n1>n2 ? n2 : n1);

  80519.   if( c ) return c;

  80520.   return n1 - n2;

  80521. }

  80522. 

  80523. /*

  80524. ** Do a comparison between a 64-bit signed integer and a 64-bit floating-point

  80525. ** number.  Return negative, zero, or positive if the first (i64) is less than,

  80526. ** equal to, or greater than the second (double).

  80527. */

  80528. static int sqlite3IntFloatCompare(i64 i, double r){

  80529.   if( sizeof(LONGDOUBLE_TYPE)>8 ){

  80530.     LONGDOUBLE_TYPE x = (LONGDOUBLE_TYPE)i;

  80531.     if( x<r ) return -1;

  80532.     if( x>r ) return +1;

  80533.     return 0;

  80534.   }else{

  80535.     i64 y;

  80536.     double s;

  80537.     if( r<-9223372036854775808.0 ) return +1;

  80538.     if( r>=9223372036854775808.0 ) return -1;

  80539.     y = (i64)r;

  80540.     if( i<y ) return -1;

  80541.     if( i>y ) return +1;

  80542.     s = (double)i;

  80543.     if( s<r ) return -1;

  80544.     if( s>r ) return +1;

  80545.     return 0;

  80546.   }

  80547. }

  80548. 

  80549. /*

  80550. ** Compare the values contained by the two memory cells, returning

  80551. ** negative, zero or positive if pMem1 is less than, equal to, or greater

  80552. ** than pMem2. Sorting order is NULL's first, followed by numbers (integers

  80553. ** and reals) sorted numerically, followed by text ordered by the collating

  80554. ** sequence pColl and finally blob's ordered by memcmp().

  80555. **

  80556. ** Two NULL values are considered equal by this function.

  80557. */

  80558. SQLITE_PRIVATE int sqlite3MemCompare(const Mem *pMem1, const Mem *pMem2, const CollSeq *pColl){

  80559.   int f1, f2;

  80560.   int combined_flags;

  80561. 

  80562.   f1 = pMem1->flags;

  80563.   f2 = pMem2->flags;

  80564.   combined_flags = f1|f2;

  80565.   assert( !sqlite3VdbeMemIsRowSet(pMem1) && !sqlite3VdbeMemIsRowSet(pMem2) );

  80566.  

  80567.   /* If one value is NULL, it is less than the other. If both values

  80568.   ** are NULL, return 0.

  80569.   */

  80570.   if( combined_flags&MEM_Null ){

  80571.     return (f2&MEM_Null) - (f1&MEM_Null);

  80572.   }

  80573. 

  80574.   /* At least one of the two values is a number

  80575.   */

  80576.   if( combined_flags&(MEM_Int|MEM_Real|MEM_IntReal) ){

  80577.     testcase( combined_flags & MEM_Int );

  80578.     testcase( combined_flags & MEM_Real );

  80579.     testcase( combined_flags & MEM_IntReal );

  80580.     if( (f1 & f2 & (MEM_Int|MEM_IntReal))!=0 ){

  80581.       testcase( f1 & f2 & MEM_Int );

  80582.       testcase( f1 & f2 & MEM_IntReal );

  80583.       if( pMem1->u.i < pMem2->u.i ) return -1;

  80584.       if( pMem1->u.i > pMem2->u.i ) return +1;

  80585.       return 0;

  80586.     }

  80587.     if( (f1 & f2 & MEM_Real)!=0 ){

  80588.       if( pMem1->u.r < pMem2->u.r ) return -1;

  80589.       if( pMem1->u.r > pMem2->u.r ) return +1;

  80590.       return 0;

  80591.     }

  80592.     if( (f1&(MEM_Int|MEM_IntReal))!=0 ){

  80593.       testcase( f1 & MEM_Int );

  80594.       testcase( f1 & MEM_IntReal );

  80595.       if( (f2&MEM_Real)!=0 ){

  80596.         return sqlite3IntFloatCompare(pMem1->u.i, pMem2->u.r);

  80597.       }else if( (f2&(MEM_Int|MEM_IntReal))!=0 ){

  80598.         if( pMem1->u.i < pMem2->u.i ) return -1;

  80599.         if( pMem1->u.i > pMem2->u.i ) return +1;

  80600.         return 0;

  80601.       }else{

  80602.         return -1;

  80603.       }

  80604.     }

  80605.     if( (f1&MEM_Real)!=0 ){

  80606.       if( (f2&(MEM_Int|MEM_IntReal))!=0 ){

  80607.         testcase( f2 & MEM_Int );

  80608.         testcase( f2 & MEM_IntReal );

  80609.         return -sqlite3IntFloatCompare(pMem2->u.i, pMem1->u.r);

  80610.       }else{

  80611.         return -1;

  80612.       }

  80613.     }

  80614.     return +1;

  80615.   }

  80616. 

  80617.   /* If one value is a string and the other is a blob, the string is less.

  80618.   ** If both are strings, compare using the collating functions.

  80619.   */

  80620.   if( combined_flags&MEM_Str ){

  80621.     if( (f1 & MEM_Str)==0 ){

  80622.       return 1;

  80623.     }

  80624.     if( (f2 & MEM_Str)==0 ){

  80625.       return -1;

  80626.     }

  80627. 

  80628.     assert( pMem1->enc==pMem2->enc || pMem1->db->mallocFailed );

  80629.     assert( pMem1->enc==SQLITE_UTF8 || 

  80630.             pMem1->enc==SQLITE_UTF16LE || pMem1->enc==SQLITE_UTF16BE );

  80631. 

  80632.     /* The collation sequence must be defined at this point, even if

  80633.     ** the user deletes the collation sequence after the vdbe program is

  80634.     ** compiled (this was not always the case).

  80635.     */

  80636.     assert( !pColl || pColl->xCmp );

  80637. 

  80638.     if( pColl ){

  80639.       return vdbeCompareMemString(pMem1, pMem2, pColl, 0);

  80640.     }

  80641.     /* If a NULL pointer was passed as the collate function, fall through

  80642.     ** to the blob case and use memcmp().  */

  80643.   }

  80644.  

  80645.   /* Both values must be blobs.  Compare using memcmp().  */

  80646.   return sqlite3BlobCompare(pMem1, pMem2);

  80647. }

  80648. 

  80649. 

  80650. /*

  80651. ** The first argument passed to this function is a serial-type that

  80652. ** corresponds to an integer - all values between 1 and 9 inclusive 

  80653. ** except 7. The second points to a buffer containing an integer value

  80654. ** serialized according to serial_type. This function deserializes

  80655. ** and returns the value.

  80656. */

  80657. static i64 vdbeRecordDecodeInt(u32 serial_type, const u8 *aKey){

  80658.   u32 y;

  80659.   assert( CORRUPT_DB || (serial_type>=1 && serial_type<=9 && serial_type!=7) );

  80660.   switch( serial_type ){

  80661.     case 0:

  80662.     case 1:

  80663.       testcase( aKey[0]&0x80 );

  80664.       return ONE_BYTE_INT(aKey);

  80665.     case 2:

  80666.       testcase( aKey[0]&0x80 );

  80667.       return TWO_BYTE_INT(aKey);

  80668.     case 3:

  80669.       testcase( aKey[0]&0x80 );

  80670.       return THREE_BYTE_INT(aKey);

  80671.     case 4: {

  80672.       testcase( aKey[0]&0x80 );

  80673.       y = FOUR_BYTE_UINT(aKey);

  80674.       return (i64)*(int*)&y;

  80675.     }

  80676.     case 5: {

  80677.       testcase( aKey[0]&0x80 );

  80678.       return FOUR_BYTE_UINT(aKey+2) + (((i64)1)<<32)*TWO_BYTE_INT(aKey);

  80679.     }

  80680.     case 6: {

  80681.       u64 x = FOUR_BYTE_UINT(aKey);

  80682.       testcase( aKey[0]&0x80 );

  80683.       x = (x<<32) | FOUR_BYTE_UINT(aKey+4);

  80684.       return (i64)*(i64*)&x;

  80685.     }

  80686.   }

  80687. 

  80688.   return (serial_type - 8);

  80689. }

  80690. 

  80691. /*

  80692. ** This function compares the two table rows or index records

  80693. ** specified by {nKey1, pKey1} and pPKey2.  It returns a negative, zero

  80694. ** or positive integer if key1 is less than, equal to or 

  80695. ** greater than key2.  The {nKey1, pKey1} key must be a blob

  80696. ** created by the OP_MakeRecord opcode of the VDBE.  The pPKey2

  80697. ** key must be a parsed key such as obtained from

  80698. ** sqlite3VdbeParseRecord.

  80699. **

  80700. ** If argument bSkip is non-zero, it is assumed that the caller has already

  80701. ** determined that the first fields of the keys are equal.

  80702. **

  80703. ** Key1 and Key2 do not have to contain the same number of fields. If all 

  80704. ** fields that appear in both keys are equal, then pPKey2->default_rc is 

  80705. ** returned.

  80706. **

  80707. ** If database corruption is discovered, set pPKey2->errCode to 

  80708. ** SQLITE_CORRUPT and return 0. If an OOM error is encountered, 

  80709. ** pPKey2->errCode is set to SQLITE_NOMEM and, if it is not NULL, the

  80710. ** malloc-failed flag set on database handle (pPKey2->pKeyInfo->db).

  80711. */

  80712. SQLITE_PRIVATE int sqlite3VdbeRecordCompareWithSkip(

  80713.   int nKey1, const void *pKey1,   /* Left key */

  80714.   UnpackedRecord *pPKey2,         /* Right key */

  80715.   int bSkip                       /* If true, skip the first field */

  80716. ){

  80717.   u32 d1;                         /* Offset into aKey[] of next data element */

  80718.   int i;                          /* Index of next field to compare */

  80719.   u32 szHdr1;                     /* Size of record header in bytes */

  80720.   u32 idx1;                       /* Offset of first type in header */

  80721.   int rc = 0;                     /* Return value */

  80722.   Mem *pRhs = pPKey2->aMem;       /* Next field of pPKey2 to compare */

  80723.   KeyInfo *pKeyInfo;

  80724.   const unsigned char *aKey1 = (const unsigned char *)pKey1;

  80725.   Mem mem1;

  80726. 

  80727.   /* If bSkip is true, then the caller has already determined that the first

  80728.   ** two elements in the keys are equal. Fix the various stack variables so

  80729.   ** that this routine begins comparing at the second field. */

  80730.   if( bSkip ){

  80731.     u32 s1;

  80732.     idx1 = 1 + getVarint32(&aKey1[1], s1);

  80733.     szHdr1 = aKey1[0];

  80734.     d1 = szHdr1 + sqlite3VdbeSerialTypeLen(s1);

  80735.     i = 1;

  80736.     pRhs++;

  80737.   }else{

  80738.     idx1 = getVarint32(aKey1, szHdr1);

  80739.     d1 = szHdr1;

  80740.     i = 0;

  80741.   }

  80742.   if( d1>(unsigned)nKey1 ){ 

  80743.     pPKey2->errCode = (u8)SQLITE_CORRUPT_BKPT;

  80744.     return 0;  /* Corruption */

  80745.   }

  80746. 

  80747.   VVA_ONLY( mem1.szMalloc = 0; ) /* Only needed by assert() statements */

  80748.   assert( pPKey2->pKeyInfo->nAllField>=pPKey2->nField 

  80749.        || CORRUPT_DB );

  80750.   assert( pPKey2->pKeyInfo->aSortOrder!=0 );

  80751.   assert( pPKey2->pKeyInfo->nKeyField>0 );

  80752.   assert( idx1<=szHdr1 || CORRUPT_DB );

  80753.   do{

  80754.     u32 serial_type;

  80755. 

  80756.     /* RHS is an integer */

  80757.     if( pRhs->flags & (MEM_Int|MEM_IntReal) ){

  80758.       testcase( pRhs->flags & MEM_Int );

  80759.       testcase( pRhs->flags & MEM_IntReal );

  80760.       serial_type = aKey1[idx1];

  80761.       testcase( serial_type==12 );

  80762.       if( serial_type>=10 ){

  80763.         rc = +1;

  80764.       }else if( serial_type==0 ){

  80765.         rc = -1;

  80766.       }else if( serial_type==7 ){

  80767.         sqlite3VdbeSerialGet(&aKey1[d1], serial_type, &mem1);

  80768.         rc = -sqlite3IntFloatCompare(pRhs->u.i, mem1.u.r);

  80769.       }else{

  80770.         i64 lhs = vdbeRecordDecodeInt(serial_type, &aKey1[d1]);

  80771.         i64 rhs = pRhs->u.i;

  80772.         if( lhs<rhs ){

  80773.           rc = -1;

  80774.         }else if( lhs>rhs ){

  80775.           rc = +1;

  80776.         }

  80777.       }

  80778.     }

  80779. 

  80780.     /* RHS is real */

  80781.     else if( pRhs->flags & MEM_Real ){

  80782.       serial_type = aKey1[idx1];

  80783.       if( serial_type>=10 ){

  80784.         /* Serial types 12 or greater are strings and blobs (greater than

  80785.         ** numbers). Types 10 and 11 are currently "reserved for future 

  80786.         ** use", so it doesn't really matter what the results of comparing

  80787.         ** them to numberic values are.  */

  80788.         rc = +1;

  80789.       }else if( serial_type==0 ){

  80790.         rc = -1;

  80791.       }else{

  80792.         sqlite3VdbeSerialGet(&aKey1[d1], serial_type, &mem1);

  80793.         if( serial_type==7 ){

  80794.           if( mem1.u.r<pRhs->u.r ){

  80795.             rc = -1;

  80796.           }else if( mem1.u.r>pRhs->u.r ){

  80797.             rc = +1;

  80798.           }

  80799.         }else{

  80800.           rc = sqlite3IntFloatCompare(mem1.u.i, pRhs->u.r);

  80801.         }

  80802.       }

  80803.     }

  80804. 

  80805.     /* RHS is a string */

  80806.     else if( pRhs->flags & MEM_Str ){

  80807.       getVarint32(&aKey1[idx1], serial_type);

  80808.       testcase( serial_type==12 );

  80809.       if( serial_type<12 ){

  80810.         rc = -1;

  80811.       }else if( !(serial_type & 0x01) ){

  80812.         rc = +1;

  80813.       }else{

  80814.         mem1.n = (serial_type - 12) / 2;

  80815.         testcase( (d1+mem1.n)==(unsigned)nKey1 );

  80816.         testcase( (d1+mem1.n+1)==(unsigned)nKey1 );

  80817.         if( (d1+mem1.n) > (unsigned)nKey1

  80818.          || (pKeyInfo = pPKey2->pKeyInfo)->nAllField<=i

  80819.         ){

  80820.           pPKey2->errCode = (u8)SQLITE_CORRUPT_BKPT;

  80821.           return 0;                /* Corruption */

  80822.         }else if( pKeyInfo->aColl[i] ){

  80823.           mem1.enc = pKeyInfo->enc;

  80824.           mem1.db = pKeyInfo->db;

  80825.           mem1.flags = MEM_Str;

  80826.           mem1.z = (char*)&aKey1[d1];

  80827.           rc = vdbeCompareMemString(

  80828.               &mem1, pRhs, pKeyInfo->aColl[i], &pPKey2->errCode

  80829.           );

  80830.         }else{

  80831.           int nCmp = MIN(mem1.n, pRhs->n);

  80832.           rc = memcmp(&aKey1[d1], pRhs->z, nCmp);

  80833.           if( rc==0 ) rc = mem1.n - pRhs->n; 

  80834.         }

  80835.       }

  80836.     }

  80837. 

  80838.     /* RHS is a blob */

  80839.     else if( pRhs->flags & MEM_Blob ){

  80840.       assert( (pRhs->flags & MEM_Zero)==0 || pRhs->n==0 );

  80841.       getVarint32(&aKey1[idx1], serial_type);

  80842.       testcase( serial_type==12 );

  80843.       if( serial_type<12 || (serial_type & 0x01) ){

  80844.         rc = -1;

  80845.       }else{

  80846.         int nStr = (serial_type - 12) / 2;

  80847.         testcase( (d1+nStr)==(unsigned)nKey1 );

  80848.         testcase( (d1+nStr+1)==(unsigned)nKey1 );

  80849.         if( (d1+nStr) > (unsigned)nKey1 ){

  80850.           pPKey2->errCode = (u8)SQLITE_CORRUPT_BKPT;

  80851.           return 0;                /* Corruption */

  80852.         }else if( pRhs->flags & MEM_Zero ){

  80853.           if( !isAllZero((const char*)&aKey1[d1],nStr) ){

  80854.             rc = 1;

  80855.           }else{

  80856.             rc = nStr - pRhs->u.nZero;

  80857.           }

  80858.         }else{

  80859.           int nCmp = MIN(nStr, pRhs->n);

  80860.           rc = memcmp(&aKey1[d1], pRhs->z, nCmp);

  80861.           if( rc==0 ) rc = nStr - pRhs->n;

  80862.         }

  80863.       }

  80864.     }

  80865. 

  80866.     /* RHS is null */

  80867.     else{

  80868.       serial_type = aKey1[idx1];

  80869.       rc = (serial_type!=0);

  80870.     }

  80871. 

  80872.     if( rc!=0 ){

  80873.       if( pPKey2->pKeyInfo->aSortOrder[i] ){

  80874.         rc = -rc;

  80875.       }

  80876.       assert( vdbeRecordCompareDebug(nKey1, pKey1, pPKey2, rc) );

  80877.       assert( mem1.szMalloc==0 );  /* See comment below */

  80878.       return rc;

  80879.     }

  80880. 

  80881.     i++;

  80882.     if( i==pPKey2->nField ) break;

  80883.     pRhs++;

  80884.     d1 += sqlite3VdbeSerialTypeLen(serial_type);

  80885.     idx1 += sqlite3VarintLen(serial_type);

  80886.   }while( idx1<(unsigned)szHdr1 && d1<=(unsigned)nKey1 );

  80887. 

  80888.   /* No memory allocation is ever used on mem1.  Prove this using

  80889.   ** the following assert().  If the assert() fails, it indicates a

  80890.   ** memory leak and a need to call sqlite3VdbeMemRelease(&mem1).  */

  80891.   assert( mem1.szMalloc==0 );

  80892. 

  80893.   /* rc==0 here means that one or both of the keys ran out of fields and

  80894.   ** all the fields up to that point were equal. Return the default_rc

  80895.   ** value.  */

  80896.   assert( CORRUPT_DB 

  80897.        || vdbeRecordCompareDebug(nKey1, pKey1, pPKey2, pPKey2->default_rc) 

  80898.        || pPKey2->pKeyInfo->db->mallocFailed

  80899.   );

  80900.   pPKey2->eqSeen = 1;

  80901.   return pPKey2->default_rc;

  80902. }

  80903. SQLITE_PRIVATE int sqlite3VdbeRecordCompare(

  80904.   int nKey1, const void *pKey1,   /* Left key */

  80905.   UnpackedRecord *pPKey2          /* Right key */

  80906. ){

  80907.   return sqlite3VdbeRecordCompareWithSkip(nKey1, pKey1, pPKey2, 0);

  80908. }

  80909. 

  80910. 

  80911. /*

  80912. ** This function is an optimized version of sqlite3VdbeRecordCompare() 

  80913. ** that (a) the first field of pPKey2 is an integer, and (b) the 

  80914. ** size-of-header varint at the start of (pKey1/nKey1) fits in a single

  80915. ** byte (i.e. is less than 128).

  80916. **

  80917. ** To avoid concerns about buffer overreads, this routine is only used

  80918. ** on schemas where the maximum valid header size is 63 bytes or less.

  80919. */

  80920. static int vdbeRecordCompareInt(

  80921.   int nKey1, const void *pKey1, /* Left key */

  80922.   UnpackedRecord *pPKey2        /* Right key */

  80923. ){

  80924.   const u8 *aKey = &((const u8*)pKey1)[*(const u8*)pKey1 & 0x3F];

  80925.   int serial_type = ((const u8*)pKey1)[1];

  80926.   int res;

  80927.   u32 y;

  80928.   u64 x;

  80929.   i64 v;

  80930.   i64 lhs;

  80931. 

  80932.   vdbeAssertFieldCountWithinLimits(nKey1, pKey1, pPKey2->pKeyInfo);

  80933.   assert( (*(u8*)pKey1)<=0x3F || CORRUPT_DB );

  80934.   switch( serial_type ){

  80935.     case 1: { /* 1-byte signed integer */

  80936.       lhs = ONE_BYTE_INT(aKey);

  80937.       testcase( lhs<0 );

  80938.       break;

  80939.     }

  80940.     case 2: { /* 2-byte signed integer */

  80941.       lhs = TWO_BYTE_INT(aKey);

  80942.       testcase( lhs<0 );

  80943.       break;

  80944.     }

  80945.     case 3: { /* 3-byte signed integer */

  80946.       lhs = THREE_BYTE_INT(aKey);

  80947.       testcase( lhs<0 );

  80948.       break;

  80949.     }

  80950.     case 4: { /* 4-byte signed integer */

  80951.       y = FOUR_BYTE_UINT(aKey);

  80952.       lhs = (i64)*(int*)&y;

  80953.       testcase( lhs<0 );

  80954.       break;

  80955.     }

  80956.     case 5: { /* 6-byte signed integer */

  80957.       lhs = FOUR_BYTE_UINT(aKey+2) + (((i64)1)<<32)*TWO_BYTE_INT(aKey);

  80958.       testcase( lhs<0 );

  80959.       break;

  80960.     }

  80961.     case 6: { /* 8-byte signed integer */

  80962.       x = FOUR_BYTE_UINT(aKey);

  80963.       x = (x<<32) | FOUR_BYTE_UINT(aKey+4);

  80964.       lhs = *(i64*)&x;

  80965.       testcase( lhs<0 );

  80966.       break;

  80967.     }

  80968.     case 8: 

  80969.       lhs = 0;

  80970.       break;

  80971.     case 9:

  80972.       lhs = 1;

  80973.       break;

  80974. 

  80975.     /* This case could be removed without changing the results of running

  80976.     ** this code. Including it causes gcc to generate a faster switch 

  80977.     ** statement (since the range of switch targets now starts at zero and

  80978.     ** is contiguous) but does not cause any duplicate code to be generated

  80979.     ** (as gcc is clever enough to combine the two like cases). Other 

  80980.     ** compilers might be similar.  */ 

  80981.     case 0: case 7:

  80982.       return sqlite3VdbeRecordCompare(nKey1, pKey1, pPKey2);

  80983. 

  80984.     default:

  80985.       return sqlite3VdbeRecordCompare(nKey1, pKey1, pPKey2);

  80986.   }

  80987. 

  80988.   v = pPKey2->aMem[0].u.i;

  80989.   if( v>lhs ){

  80990.     res = pPKey2->r1;

  80991.   }else if( v<lhs ){

  80992.     res = pPKey2->r2;

  80993.   }else if( pPKey2->nField>1 ){

  80994.     /* The first fields of the two keys are equal. Compare the trailing 

  80995.     ** fields.  */

  80996.     res = sqlite3VdbeRecordCompareWithSkip(nKey1, pKey1, pPKey2, 1);

  80997.   }else{

  80998.     /* The first fields of the two keys are equal and there are no trailing

  80999.     ** fields. Return pPKey2->default_rc in this case. */

  81000.     res = pPKey2->default_rc;

  81001.     pPKey2->eqSeen = 1;

  81002.   }

  81003. 

  81004.   assert( vdbeRecordCompareDebug(nKey1, pKey1, pPKey2, res) );

  81005.   return res;

  81006. }

  81007. 

  81008. /*

  81009. ** This function is an optimized version of sqlite3VdbeRecordCompare() 

  81010. ** that (a) the first field of pPKey2 is a string, that (b) the first field

  81011. ** uses the collation sequence BINARY and (c) that the size-of-header varint 

  81012. ** at the start of (pKey1/nKey1) fits in a single byte.

  81013. */

  81014. static int vdbeRecordCompareString(

  81015.   int nKey1, const void *pKey1, /* Left key */

  81016.   UnpackedRecord *pPKey2        /* Right key */

  81017. ){

  81018.   const u8 *aKey1 = (const u8*)pKey1;

  81019.   int serial_type;

  81020.   int res;

  81021. 

  81022.   assert( pPKey2->aMem[0].flags & MEM_Str );

  81023.   vdbeAssertFieldCountWithinLimits(nKey1, pKey1, pPKey2->pKeyInfo);

  81024.   getVarint32(&aKey1[1], serial_type);

  81025.   if( serial_type<12 ){

  81026.     res = pPKey2->r1;      /* (pKey1/nKey1) is a number or a null */

  81027.   }else if( !(serial_type & 0x01) ){ 

  81028.     res = pPKey2->r2;      /* (pKey1/nKey1) is a blob */

  81029.   }else{

  81030.     int nCmp;

  81031.     int nStr;

  81032.     int szHdr = aKey1[0];

  81033. 

  81034.     nStr = (serial_type-12) / 2;

  81035.     if( (szHdr + nStr) > nKey1 ){

  81036.       pPKey2->errCode = (u8)SQLITE_CORRUPT_BKPT;

  81037.       return 0;    /* Corruption */

  81038.     }

  81039.     nCmp = MIN( pPKey2->aMem[0].n, nStr );

  81040.     res = memcmp(&aKey1[szHdr], pPKey2->aMem[0].z, nCmp);

  81041. 

  81042.     if( res==0 ){

  81043.       res = nStr - pPKey2->aMem[0].n;

  81044.       if( res==0 ){

  81045.         if( pPKey2->nField>1 ){

  81046.           res = sqlite3VdbeRecordCompareWithSkip(nKey1, pKey1, pPKey2, 1);

  81047.         }else{

  81048.           res = pPKey2->default_rc;

  81049.           pPKey2->eqSeen = 1;

  81050.         }

  81051.       }else if( res>0 ){

  81052.         res = pPKey2->r2;

  81053.       }else{

  81054.         res = pPKey2->r1;

  81055.       }

  81056.     }else if( res>0 ){

  81057.       res = pPKey2->r2;

  81058.     }else{

  81059.       res = pPKey2->r1;

  81060.     }

  81061.   }

  81062. 

  81063.   assert( vdbeRecordCompareDebug(nKey1, pKey1, pPKey2, res)

  81064.        || CORRUPT_DB

  81065.        || pPKey2->pKeyInfo->db->mallocFailed

  81066.   );

  81067.   return res;

  81068. }

  81069. 

  81070. /*

  81071. ** Return a pointer to an sqlite3VdbeRecordCompare() compatible function

  81072. ** suitable for comparing serialized records to the unpacked record passed

  81073. ** as the only argument.

  81074. */

  81075. SQLITE_PRIVATE RecordCompare sqlite3VdbeFindCompare(UnpackedRecord *p){

  81076.   /* varintRecordCompareInt() and varintRecordCompareString() both assume

  81077.   ** that the size-of-header varint that occurs at the start of each record

  81078.   ** fits in a single byte (i.e. is 127 or less). varintRecordCompareInt()

  81079.   ** also assumes that it is safe to overread a buffer by at least the 

  81080.   ** maximum possible legal header size plus 8 bytes. Because there is

  81081.   ** guaranteed to be at least 74 (but not 136) bytes of padding following each

  81082.   ** buffer passed to varintRecordCompareInt() this makes it convenient to

  81083.   ** limit the size of the header to 64 bytes in cases where the first field

  81084.   ** is an integer.

  81085.   **

  81086.   ** The easiest way to enforce this limit is to consider only records with

  81087.   ** 13 fields or less. If the first field is an integer, the maximum legal

  81088.   ** header size is (12*5 + 1 + 1) bytes.  */

  81089.   if( p->pKeyInfo->nAllField<=13 ){

  81090.     int flags = p->aMem[0].flags;

  81091.     if( p->pKeyInfo->aSortOrder[0] ){

  81092.       p->r1 = 1;

  81093.       p->r2 = -1;

  81094.     }else{

  81095.       p->r1 = -1;

  81096.       p->r2 = 1;

  81097.     }

  81098.     if( (flags & MEM_Int) ){

  81099.       return vdbeRecordCompareInt;

  81100.     }

  81101.     testcase( flags & MEM_Real );

  81102.     testcase( flags & MEM_Null );

  81103.     testcase( flags & MEM_Blob );

  81104.     if( (flags & (MEM_Real|MEM_IntReal|MEM_Null|MEM_Blob))==0

  81105.      && p->pKeyInfo->aColl[0]==0

  81106.     ){

  81107.       assert( flags & MEM_Str );

  81108.       return vdbeRecordCompareString;

  81109.     }

  81110.   }

  81111. 

  81112.   return sqlite3VdbeRecordCompare;

  81113. }

  81114. 

  81115. /*

  81116. ** pCur points at an index entry created using the OP_MakeRecord opcode.

  81117. ** Read the rowid (the last field in the record) and store it in *rowid.

  81118. ** Return SQLITE_OK if everything works, or an error code otherwise.

  81119. **

  81120. ** pCur might be pointing to text obtained from a corrupt database file.

  81121. ** So the content cannot be trusted.  Do appropriate checks on the content.

  81122. */

  81123. SQLITE_PRIVATE int sqlite3VdbeIdxRowid(sqlite3 *db, BtCursor *pCur, i64 *rowid){

  81124.   i64 nCellKey = 0;

  81125.   int rc;

  81126.   u32 szHdr;        /* Size of the header */

  81127.   u32 typeRowid;    /* Serial type of the rowid */

  81128.   u32 lenRowid;     /* Size of the rowid */

  81129.   Mem m, v;

  81130. 

  81131.   /* Get the size of the index entry.  Only indices entries of less

  81132.   ** than 2GiB are support - anything large must be database corruption.

  81133.   ** Any corruption is detected in sqlite3BtreeParseCellPtr(), though, so

  81134.   ** this code can safely assume that nCellKey is 32-bits  

  81135.   */

  81136.   assert( sqlite3BtreeCursorIsValid(pCur) );

  81137.   nCellKey = sqlite3BtreePayloadSize(pCur);

  81138.   assert( (nCellKey & SQLITE_MAX_U32)==(u64)nCellKey );

  81139. 

  81140.   /* Read in the complete content of the index entry */

  81141.   sqlite3VdbeMemInit(&m, db, 0);

  81142.   rc = sqlite3VdbeMemFromBtree(pCur, 0, (u32)nCellKey, &m);

  81143.   if( rc ){

  81144.     return rc;

  81145.   }

  81146. 

  81147.   /* The index entry must begin with a header size */

  81148.   (void)getVarint32((u8*)m.z, szHdr);

  81149.   testcase( szHdr==3 );

  81150.   testcase( szHdr==m.n );

  81151.   testcase( szHdr>0x7fffffff );

  81152.   assert( m.n>=0 );

  81153.   if( unlikely(szHdr<3 || szHdr>(unsigned)m.n) ){

  81154.     goto idx_rowid_corruption;

  81155.   }

  81156. 

  81157.   /* The last field of the index should be an integer - the ROWID.

  81158.   ** Verify that the last entry really is an integer. */

  81159.   (void)getVarint32((u8*)&m.z[szHdr-1], typeRowid);

  81160.   testcase( typeRowid==1 );

  81161.   testcase( typeRowid==2 );

  81162.   testcase( typeRowid==3 );

  81163.   testcase( typeRowid==4 );

  81164.   testcase( typeRowid==5 );

  81165.   testcase( typeRowid==6 );

  81166.   testcase( typeRowid==8 );

  81167.   testcase( typeRowid==9 );

  81168.   if( unlikely(typeRowid<1 || typeRowid>9 || typeRowid==7) ){

  81169.     goto idx_rowid_corruption;

  81170.   }

  81171.   lenRowid = sqlite3SmallTypeSizes[typeRowid];

  81172.   testcase( (u32)m.n==szHdr+lenRowid );

  81173.   if( unlikely((u32)m.n<szHdr+lenRowid) ){

  81174.     goto idx_rowid_corruption;

  81175.   }

  81176. 

  81177.   /* Fetch the integer off the end of the index record */

  81178.   sqlite3VdbeSerialGet((u8*)&m.z[m.n-lenRowid], typeRowid, &v);

  81179.   *rowid = v.u.i;

  81180.   sqlite3VdbeMemRelease(&m);

  81181.   return SQLITE_OK;

  81182. 

  81183.   /* Jump here if database corruption is detected after m has been

  81184.   ** allocated.  Free the m object and return SQLITE_CORRUPT. */

  81185. idx_rowid_corruption:

  81186.   testcase( m.szMalloc!=0 );

  81187.   sqlite3VdbeMemRelease(&m);

  81188.   return SQLITE_CORRUPT_BKPT;

  81189. }

  81190. 

  81191. /*

  81192. ** Compare the key of the index entry that cursor pC is pointing to against

  81193. ** the key string in pUnpacked.  Write into *pRes a number

  81194. ** that is negative, zero, or positive if pC is less than, equal to,

  81195. ** or greater than pUnpacked.  Return SQLITE_OK on success.

  81196. **

  81197. ** pUnpacked is either created without a rowid or is truncated so that it

  81198. ** omits the rowid at the end.  The rowid at the end of the index entry

  81199. ** is ignored as well.  Hence, this routine only compares the prefixes 

  81200. ** of the keys prior to the final rowid, not the entire key.

  81201. */

  81202. SQLITE_PRIVATE int sqlite3VdbeIdxKeyCompare(

  81203.   sqlite3 *db,                     /* Database connection */

  81204.   VdbeCursor *pC,                  /* The cursor to compare against */

  81205.   UnpackedRecord *pUnpacked,       /* Unpacked version of key */

  81206.   int *res                         /* Write the comparison result here */

  81207. ){

  81208.   i64 nCellKey = 0;

  81209.   int rc;

  81210.   BtCursor *pCur;

  81211.   Mem m;

  81212. 

  81213.   assert( pC->eCurType==CURTYPE_BTREE );

  81214.   pCur = pC->uc.pCursor;

  81215.   assert( sqlite3BtreeCursorIsValid(pCur) );

  81216.   nCellKey = sqlite3BtreePayloadSize(pCur);

  81217.   /* nCellKey will always be between 0 and 0xffffffff because of the way

  81218.   ** that btreeParseCellPtr() and sqlite3GetVarint32() are implemented */

  81219.   if( nCellKey<=0 || nCellKey>0x7fffffff ){

  81220.     *res = 0;

  81221.     return SQLITE_CORRUPT_BKPT;

  81222.   }

  81223.   sqlite3VdbeMemInit(&m, db, 0);

  81224.   rc = sqlite3VdbeMemFromBtree(pCur, 0, (u32)nCellKey, &m);

  81225.   if( rc ){

  81226.     return rc;

  81227.   }

  81228.   *res = sqlite3VdbeRecordCompareWithSkip(m.n, m.z, pUnpacked, 0);

  81229.   sqlite3VdbeMemRelease(&m);

  81230.   return SQLITE_OK;

  81231. }

  81232. 

  81233. /*

  81234. ** This routine sets the value to be returned by subsequent calls to

  81235. ** sqlite3_changes() on the database handle 'db'. 

  81236. */

  81237. SQLITE_PRIVATE void sqlite3VdbeSetChanges(sqlite3 *db, int nChange){

  81238.   assert( sqlite3_mutex_held(db->mutex) );

  81239.   db->nChange = nChange;

  81240.   db->nTotalChange += nChange;

  81241. }

  81242. 

  81243. /*

  81244. ** Set a flag in the vdbe to update the change counter when it is finalised

  81245. ** or reset.

  81246. */

  81247. SQLITE_PRIVATE void sqlite3VdbeCountChanges(Vdbe *v){

  81248.   v->changeCntOn = 1;

  81249. }

  81250. 

  81251. /*

  81252. ** Mark every prepared statement associated with a database connection

  81253. ** as expired.

  81254. **

  81255. ** An expired statement means that recompilation of the statement is

  81256. ** recommend.  Statements expire when things happen that make their

  81257. ** programs obsolete.  Removing user-defined functions or collating

  81258. ** sequences, or changing an authorization function are the types of

  81259. ** things that make prepared statements obsolete.

  81260. **

  81261. ** If iCode is 1, then expiration is advisory.  The statement should

  81262. ** be reprepared before being restarted, but if it is already running

  81263. ** it is allowed to run to completion.

  81264. **

  81265. ** Internally, this function just sets the Vdbe.expired flag on all

  81266. ** prepared statements.  The flag is set to 1 for an immediate expiration

  81267. ** and set to 2 for an advisory expiration.

  81268. */

  81269. SQLITE_PRIVATE void sqlite3ExpirePreparedStatements(sqlite3 *db, int iCode){

  81270.   Vdbe *p;

  81271.   for(p = db->pVdbe; p; p=p->pNext){

  81272.     p->expired = iCode+1;

  81273.   }

  81274. }

  81275. 

  81276. /*

  81277. ** Return the database associated with the Vdbe.

  81278. */

  81279. SQLITE_PRIVATE sqlite3 *sqlite3VdbeDb(Vdbe *v){

  81280.   return v->db;

  81281. }

  81282. 

  81283. /*

  81284. ** Return the SQLITE_PREPARE flags for a Vdbe.

  81285. */

  81286. SQLITE_PRIVATE u8 sqlite3VdbePrepareFlags(Vdbe *v){

  81287.   return v->prepFlags;

  81288. }

  81289. 

  81290. /*

  81291. ** Return a pointer to an sqlite3_value structure containing the value bound

  81292. ** parameter iVar of VM v. Except, if the value is an SQL NULL, return 

  81293. ** 0 instead. Unless it is NULL, apply affinity aff (one of the SQLITE_AFF_*

  81294. ** constants) to the value before returning it.

  81295. **

  81296. ** The returned value must be freed by the caller using sqlite3ValueFree().

  81297. */

  81298. SQLITE_PRIVATE sqlite3_value *sqlite3VdbeGetBoundValue(Vdbe *v, int iVar, u8 aff){

  81299.   assert( iVar>0 );

  81300.   if( v ){

  81301.     Mem *pMem = &v->aVar[iVar-1];

  81302.     assert( (v->db->flags & SQLITE_EnableQPSG)==0 );

  81303.     if( 0==(pMem->flags & MEM_Null) ){

  81304.       sqlite3_value *pRet = sqlite3ValueNew(v->db);

  81305.       if( pRet ){

  81306.         sqlite3VdbeMemCopy((Mem *)pRet, pMem);

  81307.         sqlite3ValueApplyAffinity(pRet, aff, SQLITE_UTF8);

  81308.       }

  81309.       return pRet;

  81310.     }

  81311.   }

  81312.   return 0;

  81313. }

  81314. 

  81315. /*

  81316. ** Configure SQL variable iVar so that binding a new value to it signals

  81317. ** to sqlite3_reoptimize() that re-preparing the statement may result

  81318. ** in a better query plan.

  81319. */

  81320. SQLITE_PRIVATE void sqlite3VdbeSetVarmask(Vdbe *v, int iVar){

  81321.   assert( iVar>0 );

  81322.   assert( (v->db->flags & SQLITE_EnableQPSG)==0 );

  81323.   if( iVar>=32 ){

  81324.     v->expmask |= 0x80000000;

  81325.   }else{

  81326.     v->expmask |= ((u32)1 << (iVar-1));

  81327.   }

  81328. }

  81329. 

  81330. /*

  81331. ** Cause a function to throw an error if it was call from OP_PureFunc

  81332. ** rather than OP_Function.

  81333. **

  81334. ** OP_PureFunc means that the function must be deterministic, and should

  81335. ** throw an error if it is given inputs that would make it non-deterministic.

  81336. ** This routine is invoked by date/time functions that use non-deterministic

  81337. ** features such as 'now'.

  81338. */

  81339. SQLITE_PRIVATE int sqlite3NotPureFunc(sqlite3_context *pCtx){

  81340. #ifdef SQLITE_ENABLE_STAT3_OR_STAT4

  81341.   if( pCtx->pVdbe==0 ) return 1;

  81342. #endif

  81343.   if( pCtx->pVdbe->aOp[pCtx->iOp].opcode==OP_PureFunc ){

  81344.     sqlite3_result_error(pCtx, 

  81345.        "non-deterministic function in index expression or CHECK constraint",

  81346.        -1);

  81347.     return 0;

  81348.   }

  81349.   return 1;

  81350. }

  81351. 

  81352. #ifndef SQLITE_OMIT_VIRTUALTABLE

  81353. /*

  81354. ** Transfer error message text from an sqlite3_vtab.zErrMsg (text stored

  81355. ** in memory obtained from sqlite3_malloc) into a Vdbe.zErrMsg (text stored

  81356. ** in memory obtained from sqlite3DbMalloc).

  81357. */

  81358. SQLITE_PRIVATE void sqlite3VtabImportErrmsg(Vdbe *p, sqlite3_vtab *pVtab){

  81359.   if( pVtab->zErrMsg ){

  81360.     sqlite3 *db = p->db;

  81361.     sqlite3DbFree(db, p->zErrMsg);

  81362.     p->zErrMsg = sqlite3DbStrDup(db, pVtab->zErrMsg);

  81363.     sqlite3_free(pVtab->zErrMsg);

  81364.     pVtab->zErrMsg = 0;

  81365.   }

  81366. }

  81367. #endif /* SQLITE_OMIT_VIRTUALTABLE */

  81368. 

  81369. #ifdef SQLITE_ENABLE_PREUPDATE_HOOK

  81370. 

  81371. /*

  81372. ** If the second argument is not NULL, release any allocations associated 

  81373. ** with the memory cells in the p->aMem[] array. Also free the UnpackedRecord

  81374. ** structure itself, using sqlite3DbFree().

  81375. **

  81376. ** This function is used to free UnpackedRecord structures allocated by

  81377. ** the vdbeUnpackRecord() function found in vdbeapi.c.

  81378. */

  81379. static void vdbeFreeUnpacked(sqlite3 *db, int nField, UnpackedRecord *p){

  81380.   if( p ){

  81381.     int i;

  81382.     for(i=0; i<nField; i++){

  81383.       Mem *pMem = &p->aMem[i];

  81384.       if( pMem->zMalloc ) sqlite3VdbeMemRelease(pMem);

  81385.     }

  81386.     sqlite3DbFreeNN(db, p);

  81387.   }

  81388. }

  81389. #endif /* SQLITE_ENABLE_PREUPDATE_HOOK */

  81390. 

  81391. #ifdef SQLITE_ENABLE_PREUPDATE_HOOK

  81392. /*

  81393. ** Invoke the pre-update hook. If this is an UPDATE or DELETE pre-update call,

  81394. ** then cursor passed as the second argument should point to the row about

  81395. ** to be update or deleted. If the application calls sqlite3_preupdate_old(),

  81396. ** the required value will be read from the row the cursor points to.

  81397. */

  81398. SQLITE_PRIVATE void sqlite3VdbePreUpdateHook(

  81399.   Vdbe *v,                        /* Vdbe pre-update hook is invoked by */

  81400.   VdbeCursor *pCsr,               /* Cursor to grab old.* values from */

  81401.   int op,                         /* SQLITE_INSERT, UPDATE or DELETE */

  81402.   const char *zDb,                /* Database name */

  81403.   Table *pTab,                    /* Modified table */

  81404.   i64 iKey1,                      /* Initial key value */

  81405.   int iReg                        /* Register for new.* record */

  81406. ){

  81407.   sqlite3 *db = v->db;

  81408.   i64 iKey2;

  81409.   PreUpdate preupdate;

  81410.   const char *zTbl = pTab->zName;

  81411.   static const u8 fakeSortOrder = 0;

  81412. 

  81413.   assert( db->pPreUpdate==0 );

  81414.   memset(&preupdate, 0, sizeof(PreUpdate));

  81415.   if( HasRowid(pTab)==0 ){

  81416.     iKey1 = iKey2 = 0;

  81417.     preupdate.pPk = sqlite3PrimaryKeyIndex(pTab);

  81418.   }else{

  81419.     if( op==SQLITE_UPDATE ){

  81420.       iKey2 = v->aMem[iReg].u.i;

  81421.     }else{

  81422.       iKey2 = iKey1;

  81423.     }

  81424.   }

  81425. 

  81426.   assert( pCsr->nField==pTab->nCol 

  81427.        || (pCsr->nField==pTab->nCol+1 && op==SQLITE_DELETE && iReg==-1)

  81428.   );

  81429. 

  81430.   preupdate.v = v;

  81431.   preupdate.pCsr = pCsr;

  81432.   preupdate.op = op;

  81433.   preupdate.iNewReg = iReg;

  81434.   preupdate.keyinfo.db = db;

  81435.   preupdate.keyinfo.enc = ENC(db);

  81436.   preupdate.keyinfo.nKeyField = pTab->nCol;

  81437.   preupdate.keyinfo.aSortOrder = (u8*)&fakeSortOrder;

  81438.   preupdate.iKey1 = iKey1;

  81439.   preupdate.iKey2 = iKey2;

  81440.   preupdate.pTab = pTab;

  81441. 

  81442.   db->pPreUpdate = &preupdate;

  81443.   db->xPreUpdateCallback(db->pPreUpdateArg, db, op, zDb, zTbl, iKey1, iKey2);

  81444.   db->pPreUpdate = 0;

  81445.   sqlite3DbFree(db, preupdate.aRecord);

  81446.   vdbeFreeUnpacked(db, preupdate.keyinfo.nKeyField+1, preupdate.pUnpacked);

  81447.   vdbeFreeUnpacked(db, preupdate.keyinfo.nKeyField+1, preupdate.pNewUnpacked);

  81448.   if( preupdate.aNew ){

  81449.     int i;

  81450.     for(i=0; i<pCsr->nField; i++){

  81451.       sqlite3VdbeMemRelease(&preupdate.aNew[i]);

  81452.     }

  81453.     sqlite3DbFreeNN(db, preupdate.aNew);

  81454.   }

  81455. }

  81456. #endif /* SQLITE_ENABLE_PREUPDATE_HOOK */

  81457. 

  81458. /************** End of vdbeaux.c *********************************************/

  81459. /************** Begin file vdbeapi.c *****************************************/

  81460. /*

  81461. ** 2004 May 26

  81462. **

  81463. ** The author disclaims copyright to this source code.  In place of

  81464. ** a legal notice, here is a blessing:

  81465. **

  81466. **    May you do good and not evil.

  81467. **    May you find forgiveness for yourself and forgive others.

  81468. **    May you share freely, never taking more than you give.

  81469. **

  81470. *************************************************************************

  81471. **

  81472. ** This file contains code use to implement APIs that are part of the

  81473. ** VDBE.

  81474. */

  81475. /* #include "sqliteInt.h" */

  81476. /* #include "vdbeInt.h" */

  81477. 

  81478. #ifndef SQLITE_OMIT_DEPRECATED

  81479. /*

  81480. ** Return TRUE (non-zero) of the statement supplied as an argument needs

  81481. ** to be recompiled.  A statement needs to be recompiled whenever the

  81482. ** execution environment changes in a way that would alter the program

  81483. ** that sqlite3_prepare() generates.  For example, if new functions or

  81484. ** collating sequences are registered or if an authorizer function is

  81485. ** added or changed.

  81486. */

  81487. SQLITE_API int sqlite3_expired(sqlite3_stmt *pStmt){

  81488.   Vdbe *p = (Vdbe*)pStmt;

  81489.   return p==0 || p->expired;

  81490. }

  81491. #endif

  81492. 

  81493. /*

  81494. ** Check on a Vdbe to make sure it has not been finalized.  Log

  81495. ** an error and return true if it has been finalized (or is otherwise

  81496. ** invalid).  Return false if it is ok.

  81497. */

  81498. static int vdbeSafety(Vdbe *p){

  81499.   if( p->db==0 ){

  81500.     sqlite3_log(SQLITE_MISUSE, "API called with finalized prepared statement");

  81501.     return 1;

  81502.   }else{

  81503.     return 0;

  81504.   }

  81505. }

  81506. static int vdbeSafetyNotNull(Vdbe *p){

  81507.   if( p==0 ){

  81508.     sqlite3_log(SQLITE_MISUSE, "API called with NULL prepared statement");

  81509.     return 1;

  81510.   }else{

  81511.     return vdbeSafety(p);

  81512.   }

  81513. }

  81514. 

  81515. #ifndef SQLITE_OMIT_TRACE

  81516. /*

  81517. ** Invoke the profile callback.  This routine is only called if we already

  81518. ** know that the profile callback is defined and needs to be invoked.

  81519. */

  81520. static SQLITE_NOINLINE void invokeProfileCallback(sqlite3 *db, Vdbe *p){

  81521.   sqlite3_int64 iNow;

  81522.   sqlite3_int64 iElapse;

  81523.   assert( p->startTime>0 );

  81524.   assert( (db->mTrace & (SQLITE_TRACE_PROFILE|SQLITE_TRACE_XPROFILE))!=0 );

  81525.   assert( db->init.busy==0 );

  81526.   assert( p->zSql!=0 );

  81527.   sqlite3OsCurrentTimeInt64(db->pVfs, &iNow);

  81528.   iElapse = (iNow - p->startTime)*1000000;

  81529. #ifndef SQLITE_OMIT_DEPRECATED

  81530.   if( db->xProfile ){

  81531.     db->xProfile(db->pProfileArg, p->zSql, iElapse);

  81532.   }

  81533. #endif

  81534.   if( db->mTrace & SQLITE_TRACE_PROFILE ){

  81535.     db->xTrace(SQLITE_TRACE_PROFILE, db->pTraceArg, p, (void*)&iElapse);

  81536.   }

  81537.   p->startTime = 0;

  81538. }

  81539. /*

  81540. ** The checkProfileCallback(DB,P) macro checks to see if a profile callback

  81541. ** is needed, and it invokes the callback if it is needed.

  81542. */

  81543. # define checkProfileCallback(DB,P) \

  81544.    if( ((P)->startTime)>0 ){ invokeProfileCallback(DB,P); }

  81545. #else

  81546. # define checkProfileCallback(DB,P)  /*no-op*/

  81547. #endif

  81548. 

  81549. /*

  81550. ** The following routine destroys a virtual machine that is created by

  81551. ** the sqlite3_compile() routine. The integer returned is an SQLITE_

  81552. ** success/failure code that describes the result of executing the virtual

  81553. ** machine.

  81554. **

  81555. ** This routine sets the error code and string returned by

  81556. ** sqlite3_errcode(), sqlite3_errmsg() and sqlite3_errmsg16().

  81557. */

  81558. SQLITE_API int sqlite3_finalize(sqlite3_stmt *pStmt){

  81559.   int rc;

  81560.   if( pStmt==0 ){

  81561.     /* IMPLEMENTATION-OF: R-57228-12904 Invoking sqlite3_finalize() on a NULL

  81562.     ** pointer is a harmless no-op. */

  81563.     rc = SQLITE_OK;

  81564.   }else{

  81565.     Vdbe *v = (Vdbe*)pStmt;

  81566.     sqlite3 *db = v->db;

  81567.     if( vdbeSafety(v) ) return SQLITE_MISUSE_BKPT;

  81568.     sqlite3_mutex_enter(db->mutex);

  81569.     checkProfileCallback(db, v);

  81570.     rc = sqlite3VdbeFinalize(v);

  81571.     rc = sqlite3ApiExit(db, rc);

  81572.     sqlite3LeaveMutexAndCloseZombie(db);

  81573.   }

  81574.   return rc;

  81575. }

  81576. 

  81577. /*

  81578. ** Terminate the current execution of an SQL statement and reset it

  81579. ** back to its starting state so that it can be reused. A success code from

  81580. ** the prior execution is returned.

  81581. **

  81582. ** This routine sets the error code and string returned by

  81583. ** sqlite3_errcode(), sqlite3_errmsg() and sqlite3_errmsg16().

  81584. */

  81585. SQLITE_API int sqlite3_reset(sqlite3_stmt *pStmt){

  81586.   int rc;

  81587.   if( pStmt==0 ){

  81588.     rc = SQLITE_OK;

  81589.   }else{

  81590.     Vdbe *v = (Vdbe*)pStmt;

  81591.     sqlite3 *db = v->db;

  81592.     sqlite3_mutex_enter(db->mutex);

  81593.     checkProfileCallback(db, v);

  81594.     rc = sqlite3VdbeReset(v);

  81595.     sqlite3VdbeRewind(v);

  81596.     assert( (rc & (db->errMask))==rc );

  81597.     rc = sqlite3ApiExit(db, rc);

  81598.     sqlite3_mutex_leave(db->mutex);

  81599.   }

  81600.   return rc;

  81601. }

  81602. 

  81603. /*

  81604. ** Set all the parameters in the compiled SQL statement to NULL.

  81605. */

  81606. SQLITE_API int sqlite3_clear_bindings(sqlite3_stmt *pStmt){

  81607.   int i;

  81608.   int rc = SQLITE_OK;

  81609.   Vdbe *p = (Vdbe*)pStmt;

  81610. #if SQLITE_THREADSAFE

  81611.   sqlite3_mutex *mutex = ((Vdbe*)pStmt)->db->mutex;

  81612. #endif

  81613.   sqlite3_mutex_enter(mutex);

  81614.   for(i=0; i<p->nVar; i++){

  81615.     sqlite3VdbeMemRelease(&p->aVar[i]);

  81616.     p->aVar[i].flags = MEM_Null;

  81617.   }

  81618.   assert( (p->prepFlags & SQLITE_PREPARE_SAVESQL)!=0 || p->expmask==0 );

  81619.   if( p->expmask ){

  81620.     p->expired = 1;

  81621.   }

  81622.   sqlite3_mutex_leave(mutex);

  81623.   return rc;

  81624. }

  81625. 

  81626. 

  81627. /**************************** sqlite3_value_  *******************************

  81628. ** The following routines extract information from a Mem or sqlite3_value

  81629. ** structure.

  81630. */

  81631. SQLITE_API const void *sqlite3_value_blob(sqlite3_value *pVal){

  81632.   Mem *p = (Mem*)pVal;

  81633.   if( p->flags & (MEM_Blob|MEM_Str) ){

  81634.     if( ExpandBlob(p)!=SQLITE_OK ){

  81635.       assert( p->flags==MEM_Null && p->z==0 );

  81636.       return 0;

  81637.     }

  81638.     p->flags |= MEM_Blob;

  81639.     return p->n ? p->z : 0;

  81640.   }else{

  81641.     return sqlite3_value_text(pVal);

  81642.   }

  81643. }

  81644. SQLITE_API int sqlite3_value_bytes(sqlite3_value *pVal){

  81645.   return sqlite3ValueBytes(pVal, SQLITE_UTF8);

  81646. }

  81647. SQLITE_API int sqlite3_value_bytes16(sqlite3_value *pVal){

  81648.   return sqlite3ValueBytes(pVal, SQLITE_UTF16NATIVE);

  81649. }

  81650. SQLITE_API double sqlite3_value_double(sqlite3_value *pVal){

  81651.   return sqlite3VdbeRealValue((Mem*)pVal);

  81652. }

  81653. SQLITE_API int sqlite3_value_int(sqlite3_value *pVal){

  81654.   return (int)sqlite3VdbeIntValue((Mem*)pVal);

  81655. }

  81656. SQLITE_API sqlite_int64 sqlite3_value_int64(sqlite3_value *pVal){

  81657.   return sqlite3VdbeIntValue((Mem*)pVal);

  81658. }

  81659. SQLITE_API unsigned int sqlite3_value_subtype(sqlite3_value *pVal){

  81660.   Mem *pMem = (Mem*)pVal;

  81661.   return ((pMem->flags & MEM_Subtype) ? pMem->eSubtype : 0);

  81662. }

  81663. SQLITE_API void *sqlite3_value_pointer(sqlite3_value *pVal, const char *zPType){

  81664.   Mem *p = (Mem*)pVal;

  81665.   if( (p->flags&(MEM_TypeMask|MEM_Term|MEM_Subtype)) ==

  81666.                  (MEM_Null|MEM_Term|MEM_Subtype)

  81667.    && zPType!=0

  81668.    && p->eSubtype=='p'

  81669.    && strcmp(p->u.zPType, zPType)==0

  81670.   ){

  81671.     return (void*)p->z;

  81672.   }else{

  81673.     return 0;

  81674.   }

  81675. }

  81676. SQLITE_API const unsigned char *sqlite3_value_text(sqlite3_value *pVal){

  81677.   return (const unsigned char *)sqlite3ValueText(pVal, SQLITE_UTF8);

  81678. }

  81679. #ifndef SQLITE_OMIT_UTF16

  81680. SQLITE_API const void *sqlite3_value_text16(sqlite3_value* pVal){

  81681.   return sqlite3ValueText(pVal, SQLITE_UTF16NATIVE);

  81682. }

  81683. SQLITE_API const void *sqlite3_value_text16be(sqlite3_value *pVal){

  81684.   return sqlite3ValueText(pVal, SQLITE_UTF16BE);

  81685. }

  81686. SQLITE_API const void *sqlite3_value_text16le(sqlite3_value *pVal){

  81687.   return sqlite3ValueText(pVal, SQLITE_UTF16LE);

  81688. }

  81689. #endif /* SQLITE_OMIT_UTF16 */

  81690. /* EVIDENCE-OF: R-12793-43283 Every value in SQLite has one of five

  81691. ** fundamental datatypes: 64-bit signed integer 64-bit IEEE floating

  81692. ** point number string BLOB NULL

  81693. */

  81694. SQLITE_API int sqlite3_value_type(sqlite3_value* pVal){

  81695.   static const u8 aType[] = {

  81696.      SQLITE_BLOB,     /* 0x00 (not possible) */

  81697.      SQLITE_NULL,     /* 0x01 NULL */

  81698.      SQLITE_TEXT,     /* 0x02 TEXT */

  81699.      SQLITE_NULL,     /* 0x03 (not possible) */

  81700.      SQLITE_INTEGER,  /* 0x04 INTEGER */

  81701.      SQLITE_NULL,     /* 0x05 (not possible) */

  81702.      SQLITE_INTEGER,  /* 0x06 INTEGER + TEXT */

  81703.      SQLITE_NULL,     /* 0x07 (not possible) */

  81704.      SQLITE_FLOAT,    /* 0x08 FLOAT */

  81705.      SQLITE_NULL,     /* 0x09 (not possible) */

  81706.      SQLITE_FLOAT,    /* 0x0a FLOAT + TEXT */

  81707.      SQLITE_NULL,     /* 0x0b (not possible) */

  81708.      SQLITE_INTEGER,  /* 0x0c (not possible) */

  81709.      SQLITE_NULL,     /* 0x0d (not possible) */

  81710.      SQLITE_INTEGER,  /* 0x0e (not possible) */

  81711.      SQLITE_NULL,     /* 0x0f (not possible) */

  81712.      SQLITE_BLOB,     /* 0x10 BLOB */

  81713.      SQLITE_NULL,     /* 0x11 (not possible) */

  81714.      SQLITE_TEXT,     /* 0x12 (not possible) */

  81715.      SQLITE_NULL,     /* 0x13 (not possible) */

  81716.      SQLITE_INTEGER,  /* 0x14 INTEGER + BLOB */

  81717.      SQLITE_NULL,     /* 0x15 (not possible) */

  81718.      SQLITE_INTEGER,  /* 0x16 (not possible) */

  81719.      SQLITE_NULL,     /* 0x17 (not possible) */

  81720.      SQLITE_FLOAT,    /* 0x18 FLOAT + BLOB */

  81721.      SQLITE_NULL,     /* 0x19 (not possible) */

  81722.      SQLITE_FLOAT,    /* 0x1a (not possible) */

  81723.      SQLITE_NULL,     /* 0x1b (not possible) */

  81724.      SQLITE_INTEGER,  /* 0x1c (not possible) */

  81725.      SQLITE_NULL,     /* 0x1d (not possible) */

  81726.      SQLITE_INTEGER,  /* 0x1e (not possible) */

  81727.      SQLITE_NULL,     /* 0x1f (not possible) */

  81728.      SQLITE_FLOAT,    /* 0x20 INTREAL */

  81729.      SQLITE_NULL,     /* 0x21 (not possible) */

  81730.      SQLITE_TEXT,     /* 0x22 INTREAL + TEXT */

  81731.      SQLITE_NULL,     /* 0x23 (not possible) */

  81732.      SQLITE_FLOAT,    /* 0x24 (not possible) */

  81733.      SQLITE_NULL,     /* 0x25 (not possible) */

  81734.      SQLITE_FLOAT,    /* 0x26 (not possible) */

  81735.      SQLITE_NULL,     /* 0x27 (not possible) */

  81736.      SQLITE_FLOAT,    /* 0x28 (not possible) */

  81737.      SQLITE_NULL,     /* 0x29 (not possible) */

  81738.      SQLITE_FLOAT,    /* 0x2a (not possible) */

  81739.      SQLITE_NULL,     /* 0x2b (not possible) */

  81740.      SQLITE_FLOAT,    /* 0x2c (not possible) */

  81741.      SQLITE_NULL,     /* 0x2d (not possible) */

  81742.      SQLITE_FLOAT,    /* 0x2e (not possible) */

  81743.      SQLITE_NULL,     /* 0x2f (not possible) */

  81744.      SQLITE_BLOB,     /* 0x30 (not possible) */

  81745.      SQLITE_NULL,     /* 0x31 (not possible) */

  81746.      SQLITE_TEXT,     /* 0x32 (not possible) */

  81747.      SQLITE_NULL,     /* 0x33 (not possible) */

  81748.      SQLITE_FLOAT,    /* 0x34 (not possible) */

  81749.      SQLITE_NULL,     /* 0x35 (not possible) */

  81750.      SQLITE_FLOAT,    /* 0x36 (not possible) */

  81751.      SQLITE_NULL,     /* 0x37 (not possible) */

  81752.      SQLITE_FLOAT,    /* 0x38 (not possible) */

  81753.      SQLITE_NULL,     /* 0x39 (not possible) */

  81754.      SQLITE_FLOAT,    /* 0x3a (not possible) */

  81755.      SQLITE_NULL,     /* 0x3b (not possible) */

  81756.      SQLITE_FLOAT,    /* 0x3c (not possible) */

  81757.      SQLITE_NULL,     /* 0x3d (not possible) */

  81758.      SQLITE_FLOAT,    /* 0x3e (not possible) */

  81759.      SQLITE_NULL,     /* 0x3f (not possible) */

  81760.   };

  81761. #ifdef SQLITE_DEBUG

  81762.   {

  81763.     int eType = SQLITE_BLOB;

  81764.     if( pVal->flags & MEM_Null ){

  81765.       eType = SQLITE_NULL;

  81766.     }else if( pVal->flags & (MEM_Real|MEM_IntReal) ){

  81767.       eType = SQLITE_FLOAT;

  81768.     }else if( pVal->flags & MEM_Int ){

  81769.       eType = SQLITE_INTEGER;

  81770.     }else if( pVal->flags & MEM_Str ){

  81771.       eType = SQLITE_TEXT;

  81772.     }

  81773.     assert( eType == aType[pVal->flags&MEM_AffMask] );

  81774.   }

  81775. #endif

  81776.   return aType[pVal->flags&MEM_AffMask];

  81777. }

  81778. 

  81779. /* Return true if a parameter to xUpdate represents an unchanged column */

  81780. SQLITE_API int sqlite3_value_nochange(sqlite3_value *pVal){

  81781.   return (pVal->flags&(MEM_Null|MEM_Zero))==(MEM_Null|MEM_Zero);

  81782. }

  81783. 

  81784. /* Return true if a parameter value originated from an sqlite3_bind() */

  81785. SQLITE_API int sqlite3_value_frombind(sqlite3_value *pVal){

  81786.   return (pVal->flags&MEM_FromBind)!=0;

  81787. }

  81788. 

  81789. /* Make a copy of an sqlite3_value object

  81790. */

  81791. SQLITE_API sqlite3_value *sqlite3_value_dup(const sqlite3_value *pOrig){

  81792.   sqlite3_value *pNew;

  81793.   if( pOrig==0 ) return 0;

  81794.   pNew = sqlite3_malloc( sizeof(*pNew) );

  81795.   if( pNew==0 ) return 0;

  81796.   memset(pNew, 0, sizeof(*pNew));

  81797.   memcpy(pNew, pOrig, MEMCELLSIZE);

  81798.   pNew->flags &= ~MEM_Dyn;

  81799.   pNew->db = 0;

  81800.   if( pNew->flags&(MEM_Str|MEM_Blob) ){

  81801.     pNew->flags &= ~(MEM_Static|MEM_Dyn);

  81802.     pNew->flags |= MEM_Ephem;

  81803.     if( sqlite3VdbeMemMakeWriteable(pNew)!=SQLITE_OK ){

  81804.       sqlite3ValueFree(pNew);

  81805.       pNew = 0;

  81806.     }

  81807.   }

  81808.   return pNew;

  81809. }

  81810. 

  81811. /* Destroy an sqlite3_value object previously obtained from

  81812. ** sqlite3_value_dup().

  81813. */

  81814. SQLITE_API void sqlite3_value_free(sqlite3_value *pOld){

  81815.   sqlite3ValueFree(pOld);

  81816. }

  81817.   

  81818. 

  81819. /**************************** sqlite3_result_  *******************************

  81820. ** The following routines are used by user-defined functions to specify

  81821. ** the function result.

  81822. **

  81823. ** The setStrOrError() function calls sqlite3VdbeMemSetStr() to store the

  81824. ** result as a string or blob but if the string or blob is too large, it

  81825. ** then sets the error code to SQLITE_TOOBIG

  81826. **

  81827. ** The invokeValueDestructor(P,X) routine invokes destructor function X()

  81828. ** on value P is not going to be used and need to be destroyed.

  81829. */

  81830. static void setResultStrOrError(

  81831.   sqlite3_context *pCtx,  /* Function context */

  81832.   const char *z,          /* String pointer */

  81833.   int n,                  /* Bytes in string, or negative */

  81834.   u8 enc,                 /* Encoding of z.  0 for BLOBs */

  81835.   void (*xDel)(void*)     /* Destructor function */

  81836. ){

  81837.   if( sqlite3VdbeMemSetStr(pCtx->pOut, z, n, enc, xDel)==SQLITE_TOOBIG ){

  81838.     sqlite3_result_error_toobig(pCtx);

  81839.   }

  81840. }

  81841. static int invokeValueDestructor(

  81842.   const void *p,             /* Value to destroy */

  81843.   void (*xDel)(void*),       /* The destructor */

  81844.   sqlite3_context *pCtx      /* Set a SQLITE_TOOBIG error if no NULL */

  81845. ){

  81846.   assert( xDel!=SQLITE_DYNAMIC );

  81847.   if( xDel==0 ){

  81848.     /* noop */

  81849.   }else if( xDel==SQLITE_TRANSIENT ){

  81850.     /* noop */

  81851.   }else{

  81852.     xDel((void*)p);

  81853.   }

  81854.   if( pCtx ) sqlite3_result_error_toobig(pCtx);

  81855.   return SQLITE_TOOBIG;

  81856. }

  81857. SQLITE_API void sqlite3_result_blob(

  81858.   sqlite3_context *pCtx, 

  81859.   const void *z, 

  81860.   int n, 

  81861.   void (*xDel)(void *)

  81862. ){

  81863.   assert( n>=0 );

  81864.   assert( sqlite3_mutex_held(pCtx->pOut->db->mutex) );

  81865.   setResultStrOrError(pCtx, z, n, 0, xDel);

  81866. }

  81867. SQLITE_API void sqlite3_result_blob64(

  81868.   sqlite3_context *pCtx, 

  81869.   const void *z, 

  81870.   sqlite3_uint64 n,

  81871.   void (*xDel)(void *)

  81872. ){

  81873.   assert( sqlite3_mutex_held(pCtx->pOut->db->mutex) );

  81874.   assert( xDel!=SQLITE_DYNAMIC );

  81875.   if( n>0x7fffffff ){

  81876.     (void)invokeValueDestructor(z, xDel, pCtx);

  81877.   }else{

  81878.     setResultStrOrError(pCtx, z, (int)n, 0, xDel);

  81879.   }

  81880. }

  81881. SQLITE_API void sqlite3_result_double(sqlite3_context *pCtx, double rVal){

  81882.   assert( sqlite3_mutex_held(pCtx->pOut->db->mutex) );

  81883.   sqlite3VdbeMemSetDouble(pCtx->pOut, rVal);

  81884. }

  81885. SQLITE_API void sqlite3_result_error(sqlite3_context *pCtx, const char *z, int n){

  81886.   assert( sqlite3_mutex_held(pCtx->pOut->db->mutex) );

  81887.   pCtx->isError = SQLITE_ERROR;

  81888.   sqlite3VdbeMemSetStr(pCtx->pOut, z, n, SQLITE_UTF8, SQLITE_TRANSIENT);

  81889. }

  81890. #ifndef SQLITE_OMIT_UTF16

  81891. SQLITE_API void sqlite3_result_error16(sqlite3_context *pCtx, const void *z, int n){

  81892.   assert( sqlite3_mutex_held(pCtx->pOut->db->mutex) );

  81893.   pCtx->isError = SQLITE_ERROR;

  81894.   sqlite3VdbeMemSetStr(pCtx->pOut, z, n, SQLITE_UTF16NATIVE, SQLITE_TRANSIENT);

  81895. }

  81896. #endif

  81897. SQLITE_API void sqlite3_result_int(sqlite3_context *pCtx, int iVal){

  81898.   assert( sqlite3_mutex_held(pCtx->pOut->db->mutex) );

  81899.   sqlite3VdbeMemSetInt64(pCtx->pOut, (i64)iVal);

  81900. }

  81901. SQLITE_API void sqlite3_result_int64(sqlite3_context *pCtx, i64 iVal){

  81902.   assert( sqlite3_mutex_held(pCtx->pOut->db->mutex) );

  81903.   sqlite3VdbeMemSetInt64(pCtx->pOut, iVal);

  81904. }

  81905. SQLITE_API void sqlite3_result_null(sqlite3_context *pCtx){

  81906.   assert( sqlite3_mutex_held(pCtx->pOut->db->mutex) );

  81907.   sqlite3VdbeMemSetNull(pCtx->pOut);

  81908. }

  81909. SQLITE_API void sqlite3_result_pointer(

  81910.   sqlite3_context *pCtx,

  81911.   void *pPtr,

  81912.   const char *zPType,

  81913.   void (*xDestructor)(void*)

  81914. ){

  81915.   Mem *pOut = pCtx->pOut;

  81916.   assert( sqlite3_mutex_held(pOut->db->mutex) );

  81917.   sqlite3VdbeMemRelease(pOut);

  81918.   pOut->flags = MEM_Null;

  81919.   sqlite3VdbeMemSetPointer(pOut, pPtr, zPType, xDestructor);

  81920. }

  81921. SQLITE_API void sqlite3_result_subtype(sqlite3_context *pCtx, unsigned int eSubtype){

  81922.   Mem *pOut = pCtx->pOut;

  81923.   assert( sqlite3_mutex_held(pOut->db->mutex) );

  81924.   pOut->eSubtype = eSubtype & 0xff;

  81925.   pOut->flags |= MEM_Subtype;

  81926. }

  81927. SQLITE_API void sqlite3_result_text(

  81928.   sqlite3_context *pCtx, 

  81929.   const char *z, 

  81930.   int n,

  81931.   void (*xDel)(void *)

  81932. ){

  81933.   assert( sqlite3_mutex_held(pCtx->pOut->db->mutex) );

  81934.   setResultStrOrError(pCtx, z, n, SQLITE_UTF8, xDel);

  81935. }

  81936. SQLITE_API void sqlite3_result_text64(

  81937.   sqlite3_context *pCtx, 

  81938.   const char *z, 

  81939.   sqlite3_uint64 n,

  81940.   void (*xDel)(void *),

  81941.   unsigned char enc

  81942. ){

  81943.   assert( sqlite3_mutex_held(pCtx->pOut->db->mutex) );

  81944.   assert( xDel!=SQLITE_DYNAMIC );

  81945.   if( enc==SQLITE_UTF16 ) enc = SQLITE_UTF16NATIVE;

  81946.   if( n>0x7fffffff ){

  81947.     (void)invokeValueDestructor(z, xDel, pCtx);

  81948.   }else{

  81949.     setResultStrOrError(pCtx, z, (int)n, enc, xDel);

  81950.   }

  81951. }

  81952. #ifndef SQLITE_OMIT_UTF16

  81953. SQLITE_API void sqlite3_result_text16(

  81954.   sqlite3_context *pCtx, 

  81955.   const void *z, 

  81956.   int n, 

  81957.   void (*xDel)(void *)

  81958. ){

  81959.   assert( sqlite3_mutex_held(pCtx->pOut->db->mutex) );

  81960.   setResultStrOrError(pCtx, z, n, SQLITE_UTF16NATIVE, xDel);

  81961. }

  81962. SQLITE_API void sqlite3_result_text16be(

  81963.   sqlite3_context *pCtx, 

  81964.   const void *z, 

  81965.   int n, 

  81966.   void (*xDel)(void *)

  81967. ){

  81968.   assert( sqlite3_mutex_held(pCtx->pOut->db->mutex) );

  81969.   setResultStrOrError(pCtx, z, n, SQLITE_UTF16BE, xDel);

  81970. }

  81971. SQLITE_API void sqlite3_result_text16le(

  81972.   sqlite3_context *pCtx, 

  81973.   const void *z, 

  81974.   int n, 

  81975.   void (*xDel)(void *)

  81976. ){

  81977.   assert( sqlite3_mutex_held(pCtx->pOut->db->mutex) );

  81978.   setResultStrOrError(pCtx, z, n, SQLITE_UTF16LE, xDel);

  81979. }

  81980. #endif /* SQLITE_OMIT_UTF16 */

  81981. SQLITE_API void sqlite3_result_value(sqlite3_context *pCtx, sqlite3_value *pValue){

  81982.   assert( sqlite3_mutex_held(pCtx->pOut->db->mutex) );

  81983.   sqlite3VdbeMemCopy(pCtx->pOut, pValue);

  81984. }

  81985. SQLITE_API void sqlite3_result_zeroblob(sqlite3_context *pCtx, int n){

  81986.   assert( sqlite3_mutex_held(pCtx->pOut->db->mutex) );

  81987.   sqlite3VdbeMemSetZeroBlob(pCtx->pOut, n);

  81988. }

  81989. SQLITE_API int sqlite3_result_zeroblob64(sqlite3_context *pCtx, u64 n){

  81990.   Mem *pOut = pCtx->pOut;

  81991.   assert( sqlite3_mutex_held(pOut->db->mutex) );

  81992.   if( n>(u64)pOut->db->aLimit[SQLITE_LIMIT_LENGTH] ){

  81993.     return SQLITE_TOOBIG;

  81994.   }

  81995.   sqlite3VdbeMemSetZeroBlob(pCtx->pOut, (int)n);

  81996.   return SQLITE_OK;

  81997. }

  81998. SQLITE_API void sqlite3_result_error_code(sqlite3_context *pCtx, int errCode){

  81999.   pCtx->isError = errCode ? errCode : -1;

  82000. #ifdef SQLITE_DEBUG

  82001.   if( pCtx->pVdbe ) pCtx->pVdbe->rcApp = errCode;

  82002. #endif

  82003.   if( pCtx->pOut->flags & MEM_Null ){

  82004.     sqlite3VdbeMemSetStr(pCtx->pOut, sqlite3ErrStr(errCode), -1, 

  82005.                          SQLITE_UTF8, SQLITE_STATIC);

  82006.   }

  82007. }

  82008. 

  82009. /* Force an SQLITE_TOOBIG error. */

  82010. SQLITE_API void sqlite3_result_error_toobig(sqlite3_context *pCtx){

  82011.   assert( sqlite3_mutex_held(pCtx->pOut->db->mutex) );

  82012.   pCtx->isError = SQLITE_TOOBIG;

  82013.   sqlite3VdbeMemSetStr(pCtx->pOut, "string or blob too big", -1, 

  82014.                        SQLITE_UTF8, SQLITE_STATIC);

  82015. }

  82016. 

  82017. /* An SQLITE_NOMEM error. */

  82018. SQLITE_API void sqlite3_result_error_nomem(sqlite3_context *pCtx){

  82019.   assert( sqlite3_mutex_held(pCtx->pOut->db->mutex) );

  82020.   sqlite3VdbeMemSetNull(pCtx->pOut);

  82021.   pCtx->isError = SQLITE_NOMEM_BKPT;

  82022.   sqlite3OomFault(pCtx->pOut->db);

  82023. }

  82024. 

  82025. #ifndef SQLITE_UNTESTABLE

  82026. /* Force the INT64 value currently stored as the result to be

  82027. ** a MEM_IntReal value.  See the SQLITE_TESTCTRL_RESULT_INTREAL

  82028. ** test-control.

  82029. */

  82030. SQLITE_PRIVATE void sqlite3ResultIntReal(sqlite3_context *pCtx){ 

  82031.   assert( sqlite3_mutex_held(pCtx->pOut->db->mutex) );

  82032.   if( pCtx->pOut->flags & MEM_Int ){

  82033.     pCtx->pOut->flags &= ~MEM_Int;

  82034.     pCtx->pOut->flags |= MEM_IntReal;

  82035.   }

  82036. }

  82037. #endif

  82038. 

  82039. 

  82040. /*

  82041. ** This function is called after a transaction has been committed. It 

  82042. ** invokes callbacks registered with sqlite3_wal_hook() as required.

  82043. */

  82044. static int doWalCallbacks(sqlite3 *db){

  82045.   int rc = SQLITE_OK;

  82046. #ifndef SQLITE_OMIT_WAL

  82047.   int i;

  82048.   for(i=0; i<db->nDb; i++){

  82049.     Btree *pBt = db->aDb[i].pBt;

  82050.     if( pBt ){

  82051.       int nEntry;

  82052.       sqlite3BtreeEnter(pBt);

  82053.       nEntry = sqlite3PagerWalCallback(sqlite3BtreePager(pBt));

  82054.       sqlite3BtreeLeave(pBt);

  82055.       if( nEntry>0 && db->xWalCallback && rc==SQLITE_OK ){

  82056.         rc = db->xWalCallback(db->pWalArg, db, db->aDb[i].zDbSName, nEntry);

  82057.       }

  82058.     }

  82059.   }

  82060. #endif

  82061.   return rc;

  82062. }

  82063. 

  82064. 

  82065. /*

  82066. ** Execute the statement pStmt, either until a row of data is ready, the

  82067. ** statement is completely executed or an error occurs.

  82068. **

  82069. ** This routine implements the bulk of the logic behind the sqlite_step()

  82070. ** API.  The only thing omitted is the automatic recompile if a 

  82071. ** schema change has occurred.  That detail is handled by the

  82072. ** outer sqlite3_step() wrapper procedure.

  82073. */

  82074. static int sqlite3Step(Vdbe *p){

  82075.   sqlite3 *db;

  82076.   int rc;

  82077. 

  82078.   assert(p);

  82079.   if( p->magic!=VDBE_MAGIC_RUN ){

  82080.     /* We used to require that sqlite3_reset() be called before retrying

  82081.     ** sqlite3_step() after any error or after SQLITE_DONE.  But beginning

  82082.     ** with version 3.7.0, we changed this so that sqlite3_reset() would

  82083.     ** be called automatically instead of throwing the SQLITE_MISUSE error.

  82084.     ** This "automatic-reset" change is not technically an incompatibility, 

  82085.     ** since any application that receives an SQLITE_MISUSE is broken by

  82086.     ** definition.

  82087.     **

  82088.     ** Nevertheless, some published applications that were originally written

  82089.     ** for version 3.6.23 or earlier do in fact depend on SQLITE_MISUSE 

  82090.     ** returns, and those were broken by the automatic-reset change.  As a

  82091.     ** a work-around, the SQLITE_OMIT_AUTORESET compile-time restores the

  82092.     ** legacy behavior of returning SQLITE_MISUSE for cases where the 

  82093.     ** previous sqlite3_step() returned something other than a SQLITE_LOCKED

  82094.     ** or SQLITE_BUSY error.

  82095.     */

  82096. #ifdef SQLITE_OMIT_AUTORESET

  82097.     if( (rc = p->rc&0xff)==SQLITE_BUSY || rc==SQLITE_LOCKED ){

  82098.       sqlite3_reset((sqlite3_stmt*)p);

  82099.     }else{

  82100.       return SQLITE_MISUSE_BKPT;

  82101.     }

  82102. #else

  82103.     sqlite3_reset((sqlite3_stmt*)p);

  82104. #endif

  82105.   }

  82106. 

  82107.   /* Check that malloc() has not failed. If it has, return early. */

  82108.   db = p->db;

  82109.   if( db->mallocFailed ){

  82110.     p->rc = SQLITE_NOMEM;

  82111.     return SQLITE_NOMEM_BKPT;

  82112.   }

  82113. 

  82114.   if( p->pc<0 && p->expired ){

  82115.     p->rc = SQLITE_SCHEMA;

  82116.     rc = SQLITE_ERROR;

  82117.     goto end_of_step;

  82118.   }

  82119.   if( p->pc<0 ){

  82120.     /* If there are no other statements currently running, then

  82121.     ** reset the interrupt flag.  This prevents a call to sqlite3_interrupt

  82122.     ** from interrupting a statement that has not yet started.

  82123.     */

  82124.     if( db->nVdbeActive==0 ){

  82125.       db->u1.isInterrupted = 0;

  82126.     }

  82127. 

  82128.     assert( db->nVdbeWrite>0 || db->autoCommit==0 

  82129.         || (db->nDeferredCons==0 && db->nDeferredImmCons==0)

  82130.     );

  82131. 

  82132. #ifndef SQLITE_OMIT_TRACE

  82133.     if( (db->mTrace & (SQLITE_TRACE_PROFILE|SQLITE_TRACE_XPROFILE))!=0

  82134.         && !db->init.busy && p->zSql ){

  82135.       sqlite3OsCurrentTimeInt64(db->pVfs, &p->startTime);

  82136.     }else{

  82137.       assert( p->startTime==0 );

  82138.     }

  82139. #endif

  82140. 

  82141.     db->nVdbeActive++;

  82142.     if( p->readOnly==0 ) db->nVdbeWrite++;

  82143.     if( p->bIsReader ) db->nVdbeRead++;

  82144.     p->pc = 0;

  82145.   }

  82146. #ifdef SQLITE_DEBUG

  82147.   p->rcApp = SQLITE_OK;

  82148. #endif

  82149. #ifndef SQLITE_OMIT_EXPLAIN

  82150.   if( p->explain ){

  82151.     rc = sqlite3VdbeList(p);

  82152.   }else

  82153. #endif /* SQLITE_OMIT_EXPLAIN */

  82154.   {

  82155.     db->nVdbeExec++;

  82156.     rc = sqlite3VdbeExec(p);

  82157.     db->nVdbeExec--;

  82158.   }

  82159. 

  82160.   if( rc!=SQLITE_ROW ){

  82161. #ifndef SQLITE_OMIT_TRACE

  82162.     /* If the statement completed successfully, invoke the profile callback */

  82163.     checkProfileCallback(db, p);

  82164. #endif

  82165. 

  82166.     if( rc==SQLITE_DONE && db->autoCommit ){

  82167.       assert( p->rc==SQLITE_OK );

  82168.       p->rc = doWalCallbacks(db);

  82169.       if( p->rc!=SQLITE_OK ){

  82170.         rc = SQLITE_ERROR;

  82171.       }

  82172.     }

  82173.   }

  82174. 

  82175.   db->errCode = rc;

  82176.   if( SQLITE_NOMEM==sqlite3ApiExit(p->db, p->rc) ){

  82177.     p->rc = SQLITE_NOMEM_BKPT;

  82178.   }

  82179. end_of_step:

  82180.   /* At this point local variable rc holds the value that should be 

  82181.   ** returned if this statement was compiled using the legacy 

  82182.   ** sqlite3_prepare() interface. According to the docs, this can only

  82183.   ** be one of the values in the first assert() below. Variable p->rc 

  82184.   ** contains the value that would be returned if sqlite3_finalize() 

  82185.   ** were called on statement p.

  82186.   */

  82187.   assert( rc==SQLITE_ROW  || rc==SQLITE_DONE   || rc==SQLITE_ERROR 

  82188.        || (rc&0xff)==SQLITE_BUSY || rc==SQLITE_MISUSE

  82189.   );

  82190.   assert( (p->rc!=SQLITE_ROW && p->rc!=SQLITE_DONE) || p->rc==p->rcApp );

  82191.   if( rc!=SQLITE_ROW 

  82192.    && rc!=SQLITE_DONE

  82193.    && (p->prepFlags & SQLITE_PREPARE_SAVESQL)!=0

  82194.   ){

  82195.     /* If this statement was prepared using saved SQL and an 

  82196.     ** error has occurred, then return the error code in p->rc to the

  82197.     ** caller. Set the error code in the database handle to the same value.

  82198.     */ 

  82199.     rc = sqlite3VdbeTransferError(p);

  82200.   }

  82201.   return (rc&db->errMask);

  82202. }

  82203. 

  82204. /*

  82205. ** This is the top-level implementation of sqlite3_step().  Call

  82206. ** sqlite3Step() to do most of the work.  If a schema error occurs,

  82207. ** call sqlite3Reprepare() and try again.

  82208. */

  82209. SQLITE_API int sqlite3_step(sqlite3_stmt *pStmt){

  82210.   int rc = SQLITE_OK;      /* Result from sqlite3Step() */

  82211.   Vdbe *v = (Vdbe*)pStmt;  /* the prepared statement */

  82212.   int cnt = 0;             /* Counter to prevent infinite loop of reprepares */

  82213.   sqlite3 *db;             /* The database connection */

  82214. 

  82215.   if( vdbeSafetyNotNull(v) ){

  82216.     return SQLITE_MISUSE_BKPT;

  82217.   }

  82218.   db = v->db;

  82219.   sqlite3_mutex_enter(db->mutex);

  82220.   v->doingRerun = 0;

  82221.   while( (rc = sqlite3Step(v))==SQLITE_SCHEMA

  82222.          && cnt++ < SQLITE_MAX_SCHEMA_RETRY ){

  82223.     int savedPc = v->pc;

  82224.     rc = sqlite3Reprepare(v);

  82225.     if( rc!=SQLITE_OK ){

  82226.       /* This case occurs after failing to recompile an sql statement. 

  82227.       ** The error message from the SQL compiler has already been loaded 

  82228.       ** into the database handle. This block copies the error message 

  82229.       ** from the database handle into the statement and sets the statement

  82230.       ** program counter to 0 to ensure that when the statement is 

  82231.       ** finalized or reset the parser error message is available via

  82232.       ** sqlite3_errmsg() and sqlite3_errcode().

  82233.       */

  82234.       const char *zErr = (const char *)sqlite3_value_text(db->pErr); 

  82235.       sqlite3DbFree(db, v->zErrMsg);

  82236.       if( !db->mallocFailed ){

  82237.         v->zErrMsg = sqlite3DbStrDup(db, zErr);

  82238.         v->rc = rc = sqlite3ApiExit(db, rc);

  82239.       } else {

  82240.         v->zErrMsg = 0;

  82241.         v->rc = rc = SQLITE_NOMEM_BKPT;

  82242.       }

  82243.       break;

  82244.     }

  82245.     sqlite3_reset(pStmt);

  82246.     if( savedPc>=0 ) v->doingRerun = 1;

  82247.     assert( v->expired==0 );

  82248.   }

  82249.   sqlite3_mutex_leave(db->mutex);

  82250.   return rc;

  82251. }

  82252. 

  82253. 

  82254. /*

  82255. ** Extract the user data from a sqlite3_context structure and return a

  82256. ** pointer to it.

  82257. */

  82258. SQLITE_API void *sqlite3_user_data(sqlite3_context *p){

  82259.   assert( p && p->pFunc );

  82260.   return p->pFunc->pUserData;

  82261. }

  82262. 

  82263. /*

  82264. ** Extract the user data from a sqlite3_context structure and return a

  82265. ** pointer to it.

  82266. **

  82267. ** IMPLEMENTATION-OF: R-46798-50301 The sqlite3_context_db_handle() interface

  82268. ** returns a copy of the pointer to the database connection (the 1st

  82269. ** parameter) of the sqlite3_create_function() and

  82270. ** sqlite3_create_function16() routines that originally registered the

  82271. ** application defined function.

  82272. */

  82273. SQLITE_API sqlite3 *sqlite3_context_db_handle(sqlite3_context *p){

  82274.   assert( p && p->pOut );

  82275.   return p->pOut->db;

  82276. }

  82277. 

  82278. /*

  82279. ** If this routine is invoked from within an xColumn method of a virtual

  82280. ** table, then it returns true if and only if the the call is during an

  82281. ** UPDATE operation and the value of the column will not be modified

  82282. ** by the UPDATE.

  82283. **

  82284. ** If this routine is called from any context other than within the

  82285. ** xColumn method of a virtual table, then the return value is meaningless

  82286. ** and arbitrary.

  82287. **

  82288. ** Virtual table implements might use this routine to optimize their

  82289. ** performance by substituting a NULL result, or some other light-weight

  82290. ** value, as a signal to the xUpdate routine that the column is unchanged.

  82291. */

  82292. SQLITE_API int sqlite3_vtab_nochange(sqlite3_context *p){

  82293.   assert( p );

  82294.   return sqlite3_value_nochange(p->pOut);

  82295. }

  82296. 

  82297. /*

  82298. ** Return the current time for a statement.  If the current time

  82299. ** is requested more than once within the same run of a single prepared

  82300. ** statement, the exact same time is returned for each invocation regardless

  82301. ** of the amount of time that elapses between invocations.  In other words,

  82302. ** the time returned is always the time of the first call.

  82303. */

  82304. SQLITE_PRIVATE sqlite3_int64 sqlite3StmtCurrentTime(sqlite3_context *p){

  82305.   int rc;

  82306. #ifndef SQLITE_ENABLE_STAT3_OR_STAT4

  82307.   sqlite3_int64 *piTime = &p->pVdbe->iCurrentTime;

  82308.   assert( p->pVdbe!=0 );

  82309. #else

  82310.   sqlite3_int64 iTime = 0;

  82311.   sqlite3_int64 *piTime = p->pVdbe!=0 ? &p->pVdbe->iCurrentTime : &iTime;

  82312. #endif

  82313.   if( *piTime==0 ){

  82314.     rc = sqlite3OsCurrentTimeInt64(p->pOut->db->pVfs, piTime);

  82315.     if( rc ) *piTime = 0;

  82316.   }

  82317.   return *piTime;

  82318. }

  82319. 

  82320. /*

  82321. ** Create a new aggregate context for p and return a pointer to

  82322. ** its pMem->z element.

  82323. */

  82324. static SQLITE_NOINLINE void *createAggContext(sqlite3_context *p, int nByte){

  82325.   Mem *pMem = p->pMem;

  82326.   assert( (pMem->flags & MEM_Agg)==0 );

  82327.   if( nByte<=0 ){

  82328.     sqlite3VdbeMemSetNull(pMem);

  82329.     pMem->z = 0;

  82330.   }else{

  82331.     sqlite3VdbeMemClearAndResize(pMem, nByte);

  82332.     pMem->flags = MEM_Agg;

  82333.     pMem->u.pDef = p->pFunc;

  82334.     if( pMem->z ){

  82335.       memset(pMem->z, 0, nByte);

  82336.     }

  82337.   }

  82338.   return (void*)pMem->z;

  82339. }

  82340. 

  82341. /*

  82342. ** Allocate or return the aggregate context for a user function.  A new

  82343. ** context is allocated on the first call.  Subsequent calls return the

  82344. ** same context that was returned on prior calls.

  82345. */

  82346. SQLITE_API void *sqlite3_aggregate_context(sqlite3_context *p, int nByte){

  82347.   assert( p && p->pFunc && p->pFunc->xFinalize );

  82348.   assert( sqlite3_mutex_held(p->pOut->db->mutex) );

  82349.   testcase( nByte<0 );

  82350.   if( (p->pMem->flags & MEM_Agg)==0 ){

  82351.     return createAggContext(p, nByte);

  82352.   }else{

  82353.     return (void*)p->pMem->z;

  82354.   }

  82355. }

  82356. 

  82357. /*

  82358. ** Return the auxiliary data pointer, if any, for the iArg'th argument to

  82359. ** the user-function defined by pCtx.

  82360. **

  82361. ** The left-most argument is 0.

  82362. **

  82363. ** Undocumented behavior:  If iArg is negative then access a cache of

  82364. ** auxiliary data pointers that is available to all functions within a

  82365. ** single prepared statement.  The iArg values must match.

  82366. */

  82367. SQLITE_API void *sqlite3_get_auxdata(sqlite3_context *pCtx, int iArg){

  82368.   AuxData *pAuxData;

  82369. 

  82370.   assert( sqlite3_mutex_held(pCtx->pOut->db->mutex) );

  82371. #if SQLITE_ENABLE_STAT3_OR_STAT4

  82372.   if( pCtx->pVdbe==0 ) return 0;

  82373. #else

  82374.   assert( pCtx->pVdbe!=0 );

  82375. #endif

  82376.   for(pAuxData=pCtx->pVdbe->pAuxData; pAuxData; pAuxData=pAuxData->pNextAux){

  82377.     if(  pAuxData->iAuxArg==iArg && (pAuxData->iAuxOp==pCtx->iOp || iArg<0) ){

  82378.       return pAuxData->pAux;

  82379.     }

  82380.   }

  82381.   return 0;

  82382. }

  82383. 

  82384. /*

  82385. ** Set the auxiliary data pointer and delete function, for the iArg'th

  82386. ** argument to the user-function defined by pCtx. Any previous value is

  82387. ** deleted by calling the delete function specified when it was set.

  82388. **

  82389. ** The left-most argument is 0.

  82390. **

  82391. ** Undocumented behavior:  If iArg is negative then make the data available

  82392. ** to all functions within the current prepared statement using iArg as an

  82393. ** access code.

  82394. */

  82395. SQLITE_API void sqlite3_set_auxdata(

  82396.   sqlite3_context *pCtx, 

  82397.   int iArg, 

  82398.   void *pAux, 

  82399.   void (*xDelete)(void*)

  82400. ){

  82401.   AuxData *pAuxData;

  82402.   Vdbe *pVdbe = pCtx->pVdbe;

  82403. 

  82404.   assert( sqlite3_mutex_held(pCtx->pOut->db->mutex) );

  82405. #ifdef SQLITE_ENABLE_STAT3_OR_STAT4

  82406.   if( pVdbe==0 ) goto failed;

  82407. #else

  82408.   assert( pVdbe!=0 );

  82409. #endif

  82410. 

  82411.   for(pAuxData=pVdbe->pAuxData; pAuxData; pAuxData=pAuxData->pNextAux){

  82412.     if( pAuxData->iAuxArg==iArg && (pAuxData->iAuxOp==pCtx->iOp || iArg<0) ){

  82413.       break;

  82414.     }

  82415.   }

  82416.   if( pAuxData==0 ){

  82417.     pAuxData = sqlite3DbMallocZero(pVdbe->db, sizeof(AuxData));

  82418.     if( !pAuxData ) goto failed;

  82419.     pAuxData->iAuxOp = pCtx->iOp;

  82420.     pAuxData->iAuxArg = iArg;

  82421.     pAuxData->pNextAux = pVdbe->pAuxData;

  82422.     pVdbe->pAuxData = pAuxData;

  82423.     if( pCtx->isError==0 ) pCtx->isError = -1;

  82424.   }else if( pAuxData->xDeleteAux ){

  82425.     pAuxData->xDeleteAux(pAuxData->pAux);

  82426.   }

  82427. 

  82428.   pAuxData->pAux = pAux;

  82429.   pAuxData->xDeleteAux = xDelete;

  82430.   return;

  82431. 

  82432. failed:

  82433.   if( xDelete ){

  82434.     xDelete(pAux);

  82435.   }

  82436. }

  82437. 

  82438. #ifndef SQLITE_OMIT_DEPRECATED

  82439. /*

  82440. ** Return the number of times the Step function of an aggregate has been 

  82441. ** called.

  82442. **

  82443. ** This function is deprecated.  Do not use it for new code.  It is

  82444. ** provide only to avoid breaking legacy code.  New aggregate function

  82445. ** implementations should keep their own counts within their aggregate

  82446. ** context.

  82447. */

  82448. SQLITE_API int sqlite3_aggregate_count(sqlite3_context *p){

  82449.   assert( p && p->pMem && p->pFunc && p->pFunc->xFinalize );

  82450.   return p->pMem->n;

  82451. }

  82452. #endif

  82453. 

  82454. /*

  82455. ** Return the number of columns in the result set for the statement pStmt.

  82456. */

  82457. SQLITE_API int sqlite3_column_count(sqlite3_stmt *pStmt){

  82458.   Vdbe *pVm = (Vdbe *)pStmt;

  82459.   return pVm ? pVm->nResColumn : 0;

  82460. }

  82461. 

  82462. /*

  82463. ** Return the number of values available from the current row of the

  82464. ** currently executing statement pStmt.

  82465. */

  82466. SQLITE_API int sqlite3_data_count(sqlite3_stmt *pStmt){

  82467.   Vdbe *pVm = (Vdbe *)pStmt;

  82468.   if( pVm==0 || pVm->pResultSet==0 ) return 0;

  82469.   return pVm->nResColumn;

  82470. }

  82471. 

  82472. /*

  82473. ** Return a pointer to static memory containing an SQL NULL value.

  82474. */

  82475. static const Mem *columnNullValue(void){

  82476.   /* Even though the Mem structure contains an element

  82477.   ** of type i64, on certain architectures (x86) with certain compiler

  82478.   ** switches (-Os), gcc may align this Mem object on a 4-byte boundary

  82479.   ** instead of an 8-byte one. This all works fine, except that when

  82480.   ** running with SQLITE_DEBUG defined the SQLite code sometimes assert()s

  82481.   ** that a Mem structure is located on an 8-byte boundary. To prevent

  82482.   ** these assert()s from failing, when building with SQLITE_DEBUG defined

  82483.   ** using gcc, we force nullMem to be 8-byte aligned using the magical

  82484.   ** __attribute__((aligned(8))) macro.  */

  82485.   static const Mem nullMem 

  82486. #if defined(SQLITE_DEBUG) && defined(__GNUC__)

  82487.     __attribute__((aligned(8))) 

  82488. #endif

  82489.     = {

  82490.         /* .u          = */ {0},

  82491.         /* .flags      = */ (u16)MEM_Null,

  82492.         /* .enc        = */ (u8)0,

  82493.         /* .eSubtype   = */ (u8)0,

  82494.         /* .n          = */ (int)0,

  82495.         /* .z          = */ (char*)0,

  82496.         /* .zMalloc    = */ (char*)0,

  82497.         /* .szMalloc   = */ (int)0,

  82498.         /* .uTemp      = */ (u32)0,

  82499.         /* .db         = */ (sqlite3*)0,

  82500.         /* .xDel       = */ (void(*)(void*))0,

  82501. #ifdef SQLITE_DEBUG

  82502.         /* .pScopyFrom = */ (Mem*)0,

  82503.         /* .mScopyFlags= */ 0,

  82504. #endif

  82505.       };

  82506.   return &nullMem;

  82507. }

  82508. 

  82509. /*

  82510. ** Check to see if column iCol of the given statement is valid.  If

  82511. ** it is, return a pointer to the Mem for the value of that column.

  82512. ** If iCol is not valid, return a pointer to a Mem which has a value

  82513. ** of NULL.

  82514. */

  82515. static Mem *columnMem(sqlite3_stmt *pStmt, int i){

  82516.   Vdbe *pVm;

  82517.   Mem *pOut;

  82518. 

  82519.   pVm = (Vdbe *)pStmt;

  82520.   if( pVm==0 ) return (Mem*)columnNullValue();

  82521.   assert( pVm->db );

  82522.   sqlite3_mutex_enter(pVm->db->mutex);

  82523.   if( pVm->pResultSet!=0 && i<pVm->nResColumn && i>=0 ){

  82524.     pOut = &pVm->pResultSet[i];

  82525.   }else{

  82526.     sqlite3Error(pVm->db, SQLITE_RANGE);

  82527.     pOut = (Mem*)columnNullValue();

  82528.   }

  82529.   return pOut;

  82530. }

  82531. 

  82532. /*

  82533. ** This function is called after invoking an sqlite3_value_XXX function on a 

  82534. ** column value (i.e. a value returned by evaluating an SQL expression in the

  82535. ** select list of a SELECT statement) that may cause a malloc() failure. If 

  82536. ** malloc() has failed, the threads mallocFailed flag is cleared and the result

  82537. ** code of statement pStmt set to SQLITE_NOMEM.

  82538. **

  82539. ** Specifically, this is called from within:

  82540. **

  82541. **     sqlite3_column_int()

  82542. **     sqlite3_column_int64()

  82543. **     sqlite3_column_text()

  82544. **     sqlite3_column_text16()

  82545. **     sqlite3_column_real()

  82546. **     sqlite3_column_bytes()

  82547. **     sqlite3_column_bytes16()

  82548. **     sqiite3_column_blob()

  82549. */

  82550. static void columnMallocFailure(sqlite3_stmt *pStmt)

  82551. {

  82552.   /* If malloc() failed during an encoding conversion within an

  82553.   ** sqlite3_column_XXX API, then set the return code of the statement to

  82554.   ** SQLITE_NOMEM. The next call to _step() (if any) will return SQLITE_ERROR

  82555.   ** and _finalize() will return NOMEM.

  82556.   */

  82557.   Vdbe *p = (Vdbe *)pStmt;

  82558.   if( p ){

  82559.     assert( p->db!=0 );

  82560.     assert( sqlite3_mutex_held(p->db->mutex) );

  82561.     p->rc = sqlite3ApiExit(p->db, p->rc);

  82562.     sqlite3_mutex_leave(p->db->mutex);

  82563.   }

  82564. }

  82565. 

  82566. /**************************** sqlite3_column_  *******************************

  82567. ** The following routines are used to access elements of the current row

  82568. ** in the result set.

  82569. */

  82570. SQLITE_API const void *sqlite3_column_blob(sqlite3_stmt *pStmt, int i){

  82571.   const void *val;

  82572.   val = sqlite3_value_blob( columnMem(pStmt,i) );

  82573.   /* Even though there is no encoding conversion, value_blob() might

  82574.   ** need to call malloc() to expand the result of a zeroblob() 

  82575.   ** expression. 

  82576.   */

  82577.   columnMallocFailure(pStmt);

  82578.   return val;

  82579. }

  82580. SQLITE_API int sqlite3_column_bytes(sqlite3_stmt *pStmt, int i){

  82581.   int val = sqlite3_value_bytes( columnMem(pStmt,i) );

  82582.   columnMallocFailure(pStmt);

  82583.   return val;

  82584. }

  82585. SQLITE_API int sqlite3_column_bytes16(sqlite3_stmt *pStmt, int i){

  82586.   int val = sqlite3_value_bytes16( columnMem(pStmt,i) );

  82587.   columnMallocFailure(pStmt);

  82588.   return val;

  82589. }

  82590. SQLITE_API double sqlite3_column_double(sqlite3_stmt *pStmt, int i){

  82591.   double val = sqlite3_value_double( columnMem(pStmt,i) );

  82592.   columnMallocFailure(pStmt);

  82593.   return val;

  82594. }

  82595. SQLITE_API int sqlite3_column_int(sqlite3_stmt *pStmt, int i){

  82596.   int val = sqlite3_value_int( columnMem(pStmt,i) );

  82597.   columnMallocFailure(pStmt);

  82598.   return val;

  82599. }

  82600. SQLITE_API sqlite_int64 sqlite3_column_int64(sqlite3_stmt *pStmt, int i){

  82601.   sqlite_int64 val = sqlite3_value_int64( columnMem(pStmt,i) );

  82602.   columnMallocFailure(pStmt);

  82603.   return val;

  82604. }

  82605. SQLITE_API const unsigned char *sqlite3_column_text(sqlite3_stmt *pStmt, int i){

  82606.   const unsigned char *val = sqlite3_value_text( columnMem(pStmt,i) );

  82607.   columnMallocFailure(pStmt);

  82608.   return val;

  82609. }

  82610. SQLITE_API sqlite3_value *sqlite3_column_value(sqlite3_stmt *pStmt, int i){

  82611.   Mem *pOut = columnMem(pStmt, i);

  82612.   if( pOut->flags&MEM_Static ){

  82613.     pOut->flags &= ~MEM_Static;

  82614.     pOut->flags |= MEM_Ephem;

  82615.   }

  82616.   columnMallocFailure(pStmt);

  82617.   return (sqlite3_value *)pOut;

  82618. }

  82619. #ifndef SQLITE_OMIT_UTF16

  82620. SQLITE_API const void *sqlite3_column_text16(sqlite3_stmt *pStmt, int i){

  82621.   const void *val = sqlite3_value_text16( columnMem(pStmt,i) );

  82622.   columnMallocFailure(pStmt);

  82623.   return val;

  82624. }

  82625. #endif /* SQLITE_OMIT_UTF16 */

  82626. SQLITE_API int sqlite3_column_type(sqlite3_stmt *pStmt, int i){

  82627.   int iType = sqlite3_value_type( columnMem(pStmt,i) );

  82628.   columnMallocFailure(pStmt);

  82629.   return iType;

  82630. }

  82631. 

  82632. /*

  82633. ** Convert the N-th element of pStmt->pColName[] into a string using

  82634. ** xFunc() then return that string.  If N is out of range, return 0.

  82635. **

  82636. ** There are up to 5 names for each column.  useType determines which

  82637. ** name is returned.  Here are the names:

  82638. **

  82639. **    0      The column name as it should be displayed for output

  82640. **    1      The datatype name for the column

  82641. **    2      The name of the database that the column derives from

  82642. **    3      The name of the table that the column derives from

  82643. **    4      The name of the table column that the result column derives from

  82644. **

  82645. ** If the result is not a simple column reference (if it is an expression

  82646. ** or a constant) then useTypes 2, 3, and 4 return NULL.

  82647. */

  82648. static const void *columnName(

  82649.   sqlite3_stmt *pStmt,     /* The statement */

  82650.   int N,                   /* Which column to get the name for */

  82651.   int useUtf16,            /* True to return the name as UTF16 */

  82652.   int useType              /* What type of name */

  82653. ){

  82654.   const void *ret;

  82655.   Vdbe *p;

  82656.   int n;

  82657.   sqlite3 *db;

  82658. #ifdef SQLITE_ENABLE_API_ARMOR

  82659.   if( pStmt==0 ){

  82660.     (void)SQLITE_MISUSE_BKPT;

  82661.     return 0;

  82662.   }

  82663. #endif

  82664.   ret = 0;

  82665.   p = (Vdbe *)pStmt;

  82666.   db = p->db;

  82667.   assert( db!=0 );

  82668.   n = sqlite3_column_count(pStmt);

  82669.   if( N<n && N>=0 ){

  82670.     N += useType*n;

  82671.     sqlite3_mutex_enter(db->mutex);

  82672.     assert( db->mallocFailed==0 );

  82673. #ifndef SQLITE_OMIT_UTF16

  82674.     if( useUtf16 ){

  82675.       ret = sqlite3_value_text16((sqlite3_value*)&p->aColName[N]);

  82676.     }else

  82677. #endif

  82678.     {

  82679.       ret = sqlite3_value_text((sqlite3_value*)&p->aColName[N]);

  82680.     }

  82681.     /* A malloc may have failed inside of the _text() call. If this

  82682.     ** is the case, clear the mallocFailed flag and return NULL.

  82683.     */

  82684.     if( db->mallocFailed ){

  82685.       sqlite3OomClear(db);

  82686.       ret = 0;

  82687.     }

  82688.     sqlite3_mutex_leave(db->mutex);

  82689.   }

  82690.   return ret;

  82691. }

  82692. 

  82693. /*

  82694. ** Return the name of the Nth column of the result set returned by SQL

  82695. ** statement pStmt.

  82696. */

  82697. SQLITE_API const char *sqlite3_column_name(sqlite3_stmt *pStmt, int N){

  82698.   return columnName(pStmt, N, 0, COLNAME_NAME);

  82699. }

  82700. #ifndef SQLITE_OMIT_UTF16

  82701. SQLITE_API const void *sqlite3_column_name16(sqlite3_stmt *pStmt, int N){

  82702.   return columnName(pStmt, N, 1, COLNAME_NAME);

  82703. }

  82704. #endif

  82705. 

  82706. /*

  82707. ** Constraint:  If you have ENABLE_COLUMN_METADATA then you must

  82708. ** not define OMIT_DECLTYPE.

  82709. */

  82710. #if defined(SQLITE_OMIT_DECLTYPE) && defined(SQLITE_ENABLE_COLUMN_METADATA)

  82711. # error "Must not define both SQLITE_OMIT_DECLTYPE \

  82712.          and SQLITE_ENABLE_COLUMN_METADATA"

  82713. #endif

  82714. 

  82715. #ifndef SQLITE_OMIT_DECLTYPE

  82716. /*

  82717. ** Return the column declaration type (if applicable) of the 'i'th column

  82718. ** of the result set of SQL statement pStmt.

  82719. */

  82720. SQLITE_API const char *sqlite3_column_decltype(sqlite3_stmt *pStmt, int N){

  82721.   return columnName(pStmt, N, 0, COLNAME_DECLTYPE);

  82722. }

  82723. #ifndef SQLITE_OMIT_UTF16

  82724. SQLITE_API const void *sqlite3_column_decltype16(sqlite3_stmt *pStmt, int N){

  82725.   return columnName(pStmt, N, 1, COLNAME_DECLTYPE);

  82726. }

  82727. #endif /* SQLITE_OMIT_UTF16 */

  82728. #endif /* SQLITE_OMIT_DECLTYPE */

  82729. 

  82730. #ifdef SQLITE_ENABLE_COLUMN_METADATA

  82731. /*

  82732. ** Return the name of the database from which a result column derives.

  82733. ** NULL is returned if the result column is an expression or constant or

  82734. ** anything else which is not an unambiguous reference to a database column.

  82735. */

  82736. SQLITE_API const char *sqlite3_column_database_name(sqlite3_stmt *pStmt, int N){

  82737.   return columnName(pStmt, N, 0, COLNAME_DATABASE);

  82738. }

  82739. #ifndef SQLITE_OMIT_UTF16

  82740. SQLITE_API const void *sqlite3_column_database_name16(sqlite3_stmt *pStmt, int N){

  82741.   return columnName(pStmt, N, 1, COLNAME_DATABASE);

  82742. }

  82743. #endif /* SQLITE_OMIT_UTF16 */

  82744. 

  82745. /*

  82746. ** Return the name of the table from which a result column derives.

  82747. ** NULL is returned if the result column is an expression or constant or

  82748. ** anything else which is not an unambiguous reference to a database column.

  82749. */

  82750. SQLITE_API const char *sqlite3_column_table_name(sqlite3_stmt *pStmt, int N){

  82751.   return columnName(pStmt, N, 0, COLNAME_TABLE);

  82752. }

  82753. #ifndef SQLITE_OMIT_UTF16

  82754. SQLITE_API const void *sqlite3_column_table_name16(sqlite3_stmt *pStmt, int N){

  82755.   return columnName(pStmt, N, 1, COLNAME_TABLE);

  82756. }

  82757. #endif /* SQLITE_OMIT_UTF16 */

  82758. 

  82759. /*

  82760. ** Return the name of the table column from which a result column derives.

  82761. ** NULL is returned if the result column is an expression or constant or

  82762. ** anything else which is not an unambiguous reference to a database column.

  82763. */

  82764. SQLITE_API const char *sqlite3_column_origin_name(sqlite3_stmt *pStmt, int N){

  82765.   return columnName(pStmt, N, 0, COLNAME_COLUMN);

  82766. }

  82767. #ifndef SQLITE_OMIT_UTF16

  82768. SQLITE_API const void *sqlite3_column_origin_name16(sqlite3_stmt *pStmt, int N){

  82769.   return columnName(pStmt, N, 1, COLNAME_COLUMN);

  82770. }

  82771. #endif /* SQLITE_OMIT_UTF16 */

  82772. #endif /* SQLITE_ENABLE_COLUMN_METADATA */

  82773. 

  82774. 

  82775. /******************************* sqlite3_bind_  ***************************

  82776. ** 

  82777. ** Routines used to attach values to wildcards in a compiled SQL statement.

  82778. */

  82779. /*

  82780. ** Unbind the value bound to variable i in virtual machine p. This is the 

  82781. ** the same as binding a NULL value to the column. If the "i" parameter is

  82782. ** out of range, then SQLITE_RANGE is returned. Othewise SQLITE_OK.

  82783. **

  82784. ** A successful evaluation of this routine acquires the mutex on p.

  82785. ** the mutex is released if any kind of error occurs.

  82786. **

  82787. ** The error code stored in database p->db is overwritten with the return

  82788. ** value in any case.

  82789. */

  82790. static int vdbeUnbind(Vdbe *p, int i){

  82791.   Mem *pVar;

  82792.   if( vdbeSafetyNotNull(p) ){

  82793.     return SQLITE_MISUSE_BKPT;

  82794.   }

  82795.   sqlite3_mutex_enter(p->db->mutex);

  82796.   if( p->magic!=VDBE_MAGIC_RUN || p->pc>=0 ){

  82797.     sqlite3Error(p->db, SQLITE_MISUSE);

  82798.     sqlite3_mutex_leave(p->db->mutex);

  82799.     sqlite3_log(SQLITE_MISUSE, 

  82800.         "bind on a busy prepared statement: [%s]", p->zSql);

  82801.     return SQLITE_MISUSE_BKPT;

  82802.   }

  82803.   if( i<1 || i>p->nVar ){

  82804.     sqlite3Error(p->db, SQLITE_RANGE);

  82805.     sqlite3_mutex_leave(p->db->mutex);

  82806.     return SQLITE_RANGE;

  82807.   }

  82808.   i--;

  82809.   pVar = &p->aVar[i];

  82810.   sqlite3VdbeMemRelease(pVar);

  82811.   pVar->flags = MEM_Null;

  82812.   p->db->errCode = SQLITE_OK;

  82813. 

  82814.   /* If the bit corresponding to this variable in Vdbe.expmask is set, then 

  82815.   ** binding a new value to this variable invalidates the current query plan.

  82816.   **

  82817.   ** IMPLEMENTATION-OF: R-48440-37595 If the specific value bound to host

  82818.   ** parameter in the WHERE clause might influence the choice of query plan

  82819.   ** for a statement, then the statement will be automatically recompiled,

  82820.   ** as if there had been a schema change, on the first sqlite3_step() call

  82821.   ** following any change to the bindings of that parameter.

  82822.   */

  82823.   assert( (p->prepFlags & SQLITE_PREPARE_SAVESQL)!=0 || p->expmask==0 );

  82824.   if( p->expmask!=0 && (p->expmask & (i>=31 ? 0x80000000 : (u32)1<<i))!=0 ){

  82825.     p->expired = 1;

  82826.   }

  82827.   return SQLITE_OK;

  82828. }

  82829. 

  82830. /*

  82831. ** Bind a text or BLOB value.

  82832. */

  82833. static int bindText(

  82834.   sqlite3_stmt *pStmt,   /* The statement to bind against */

  82835.   int i,                 /* Index of the parameter to bind */

  82836.   const void *zData,     /* Pointer to the data to be bound */

  82837.   int nData,             /* Number of bytes of data to be bound */

  82838.   void (*xDel)(void*),   /* Destructor for the data */

  82839.   u8 encoding            /* Encoding for the data */

  82840. ){

  82841.   Vdbe *p = (Vdbe *)pStmt;

  82842.   Mem *pVar;

  82843.   int rc;

  82844. 

  82845.   rc = vdbeUnbind(p, i);

  82846.   if( rc==SQLITE_OK ){

  82847.     if( zData!=0 ){

  82848.       pVar = &p->aVar[i-1];

  82849.       rc = sqlite3VdbeMemSetStr(pVar, zData, nData, encoding, xDel);

  82850.       if( rc==SQLITE_OK && encoding!=0 ){

  82851.         rc = sqlite3VdbeChangeEncoding(pVar, ENC(p->db));

  82852.       }

  82853.       if( rc ){

  82854.         sqlite3Error(p->db, rc);

  82855.         rc = sqlite3ApiExit(p->db, rc);

  82856.       }

  82857.     }

  82858.     sqlite3_mutex_leave(p->db->mutex);

  82859.   }else if( xDel!=SQLITE_STATIC && xDel!=SQLITE_TRANSIENT ){

  82860.     xDel((void*)zData);

  82861.   }

  82862.   return rc;

  82863. }

  82864. 

  82865. 

  82866. /*

  82867. ** Bind a blob value to an SQL statement variable.

  82868. */

  82869. SQLITE_API int sqlite3_bind_blob(

  82870.   sqlite3_stmt *pStmt, 

  82871.   int i, 

  82872.   const void *zData, 

  82873.   int nData, 

  82874.   void (*xDel)(void*)

  82875. ){

  82876. #ifdef SQLITE_ENABLE_API_ARMOR

  82877.   if( nData<0 ) return SQLITE_MISUSE_BKPT;

  82878. #endif

  82879.   return bindText(pStmt, i, zData, nData, xDel, 0);

  82880. }

  82881. SQLITE_API int sqlite3_bind_blob64(

  82882.   sqlite3_stmt *pStmt, 

  82883.   int i, 

  82884.   const void *zData, 

  82885.   sqlite3_uint64 nData, 

  82886.   void (*xDel)(void*)

  82887. ){

  82888.   assert( xDel!=SQLITE_DYNAMIC );

  82889.   if( nData>0x7fffffff ){

  82890.     return invokeValueDestructor(zData, xDel, 0);

  82891.   }else{

  82892.     return bindText(pStmt, i, zData, (int)nData, xDel, 0);

  82893.   }

  82894. }

  82895. SQLITE_API int sqlite3_bind_double(sqlite3_stmt *pStmt, int i, double rValue){

  82896.   int rc;

  82897.   Vdbe *p = (Vdbe *)pStmt;

  82898.   rc = vdbeUnbind(p, i);

  82899.   if( rc==SQLITE_OK ){

  82900.     sqlite3VdbeMemSetDouble(&p->aVar[i-1], rValue);

  82901.     sqlite3_mutex_leave(p->db->mutex);

  82902.   }

  82903.   return rc;

  82904. }

  82905. SQLITE_API int sqlite3_bind_int(sqlite3_stmt *p, int i, int iValue){

  82906.   return sqlite3_bind_int64(p, i, (i64)iValue);

  82907. }

  82908. SQLITE_API int sqlite3_bind_int64(sqlite3_stmt *pStmt, int i, sqlite_int64 iValue){

  82909.   int rc;

  82910.   Vdbe *p = (Vdbe *)pStmt;

  82911.   rc = vdbeUnbind(p, i);

  82912.   if( rc==SQLITE_OK ){

  82913.     sqlite3VdbeMemSetInt64(&p->aVar[i-1], iValue);

  82914.     sqlite3_mutex_leave(p->db->mutex);

  82915.   }

  82916.   return rc;

  82917. }

  82918. SQLITE_API int sqlite3_bind_null(sqlite3_stmt *pStmt, int i){

  82919.   int rc;

  82920.   Vdbe *p = (Vdbe*)pStmt;

  82921.   rc = vdbeUnbind(p, i);

  82922.   if( rc==SQLITE_OK ){

  82923.     sqlite3_mutex_leave(p->db->mutex);

  82924.   }

  82925.   return rc;

  82926. }

  82927. SQLITE_API int sqlite3_bind_pointer(

  82928.   sqlite3_stmt *pStmt,

  82929.   int i,

  82930.   void *pPtr,

  82931.   const char *zPTtype,

  82932.   void (*xDestructor)(void*)

  82933. ){

  82934.   int rc;

  82935.   Vdbe *p = (Vdbe*)pStmt;

  82936.   rc = vdbeUnbind(p, i);

  82937.   if( rc==SQLITE_OK ){

  82938.     sqlite3VdbeMemSetPointer(&p->aVar[i-1], pPtr, zPTtype, xDestructor);

  82939.     sqlite3_mutex_leave(p->db->mutex);

  82940.   }else if( xDestructor ){

  82941.     xDestructor(pPtr);

  82942.   }

  82943.   return rc;

  82944. }

  82945. SQLITE_API int sqlite3_bind_text( 

  82946.   sqlite3_stmt *pStmt, 

  82947.   int i, 

  82948.   const char *zData, 

  82949.   int nData, 

  82950.   void (*xDel)(void*)

  82951. ){

  82952.   return bindText(pStmt, i, zData, nData, xDel, SQLITE_UTF8);

  82953. }

  82954. SQLITE_API int sqlite3_bind_text64( 

  82955.   sqlite3_stmt *pStmt, 

  82956.   int i, 

  82957.   const char *zData, 

  82958.   sqlite3_uint64 nData, 

  82959.   void (*xDel)(void*),

  82960.   unsigned char enc

  82961. ){

  82962.   assert( xDel!=SQLITE_DYNAMIC );

  82963.   if( nData>0x7fffffff ){

  82964.     return invokeValueDestructor(zData, xDel, 0);

  82965.   }else{

  82966.     if( enc==SQLITE_UTF16 ) enc = SQLITE_UTF16NATIVE;

  82967.     return bindText(pStmt, i, zData, (int)nData, xDel, enc);

  82968.   }

  82969. }

  82970. #ifndef SQLITE_OMIT_UTF16

  82971. SQLITE_API int sqlite3_bind_text16(

  82972.   sqlite3_stmt *pStmt, 

  82973.   int i, 

  82974.   const void *zData, 

  82975.   int nData, 

  82976.   void (*xDel)(void*)

  82977. ){

  82978.   return bindText(pStmt, i, zData, nData, xDel, SQLITE_UTF16NATIVE);

  82979. }

  82980. #endif /* SQLITE_OMIT_UTF16 */

  82981. SQLITE_API int sqlite3_bind_value(sqlite3_stmt *pStmt, int i, const sqlite3_value *pValue){

  82982.   int rc;

  82983.   switch( sqlite3_value_type((sqlite3_value*)pValue) ){

  82984.     case SQLITE_INTEGER: {

  82985.       rc = sqlite3_bind_int64(pStmt, i, pValue->u.i);

  82986.       break;

  82987.     }

  82988.     case SQLITE_FLOAT: {

  82989.       rc = sqlite3_bind_double(pStmt, i, pValue->u.r);

  82990.       break;

  82991.     }

  82992.     case SQLITE_BLOB: {

  82993.       if( pValue->flags & MEM_Zero ){

  82994.         rc = sqlite3_bind_zeroblob(pStmt, i, pValue->u.nZero);

  82995.       }else{

  82996.         rc = sqlite3_bind_blob(pStmt, i, pValue->z, pValue->n,SQLITE_TRANSIENT);

  82997.       }

  82998.       break;

  82999.     }

  83000.     case SQLITE_TEXT: {

  83001.       rc = bindText(pStmt,i,  pValue->z, pValue->n, SQLITE_TRANSIENT,

  83002.                               pValue->enc);

  83003.       break;

  83004.     }

  83005.     default: {

  83006.       rc = sqlite3_bind_null(pStmt, i);

  83007.       break;

  83008.     }

  83009.   }

  83010.   return rc;

  83011. }

  83012. SQLITE_API int sqlite3_bind_zeroblob(sqlite3_stmt *pStmt, int i, int n){

  83013.   int rc;

  83014.   Vdbe *p = (Vdbe *)pStmt;

  83015.   rc = vdbeUnbind(p, i);

  83016.   if( rc==SQLITE_OK ){

  83017.     sqlite3VdbeMemSetZeroBlob(&p->aVar[i-1], n);

  83018.     sqlite3_mutex_leave(p->db->mutex);

  83019.   }

  83020.   return rc;

  83021. }

  83022. SQLITE_API int sqlite3_bind_zeroblob64(sqlite3_stmt *pStmt, int i, sqlite3_uint64 n){

  83023.   int rc;

  83024.   Vdbe *p = (Vdbe *)pStmt;

  83025.   sqlite3_mutex_enter(p->db->mutex);

  83026.   if( n>(u64)p->db->aLimit[SQLITE_LIMIT_LENGTH] ){

  83027.     rc = SQLITE_TOOBIG;

  83028.   }else{

  83029.     assert( (n & 0x7FFFFFFF)==n );

  83030.     rc = sqlite3_bind_zeroblob(pStmt, i, n);

  83031.   }

  83032.   rc = sqlite3ApiExit(p->db, rc);

  83033.   sqlite3_mutex_leave(p->db->mutex);

  83034.   return rc;

  83035. }

  83036. 

  83037. /*

  83038. ** Return the number of wildcards that can be potentially bound to.

  83039. ** This routine is added to support DBD::SQLite.  

  83040. */

  83041. SQLITE_API int sqlite3_bind_parameter_count(sqlite3_stmt *pStmt){

  83042.   Vdbe *p = (Vdbe*)pStmt;

  83043.   return p ? p->nVar : 0;

  83044. }

  83045. 

  83046. /*

  83047. ** Return the name of a wildcard parameter.  Return NULL if the index

  83048. ** is out of range or if the wildcard is unnamed.

  83049. **

  83050. ** The result is always UTF-8.

  83051. */

  83052. SQLITE_API const char *sqlite3_bind_parameter_name(sqlite3_stmt *pStmt, int i){

  83053.   Vdbe *p = (Vdbe*)pStmt;

  83054.   if( p==0 ) return 0;

  83055.   return sqlite3VListNumToName(p->pVList, i);

  83056. }

  83057. 

  83058. /*

  83059. ** Given a wildcard parameter name, return the index of the variable

  83060. ** with that name.  If there is no variable with the given name,

  83061. ** return 0.

  83062. */

  83063. SQLITE_PRIVATE int sqlite3VdbeParameterIndex(Vdbe *p, const char *zName, int nName){

  83064.   if( p==0 || zName==0 ) return 0;

  83065.   return sqlite3VListNameToNum(p->pVList, zName, nName);

  83066. }

  83067. SQLITE_API int sqlite3_bind_parameter_index(sqlite3_stmt *pStmt, const char *zName){

  83068.   return sqlite3VdbeParameterIndex((Vdbe*)pStmt, zName, sqlite3Strlen30(zName));

  83069. }

  83070. 

  83071. /*

  83072. ** Transfer all bindings from the first statement over to the second.

  83073. */

  83074. SQLITE_PRIVATE int sqlite3TransferBindings(sqlite3_stmt *pFromStmt, sqlite3_stmt *pToStmt){

  83075.   Vdbe *pFrom = (Vdbe*)pFromStmt;

  83076.   Vdbe *pTo = (Vdbe*)pToStmt;

  83077.   int i;

  83078.   assert( pTo->db==pFrom->db );

  83079.   assert( pTo->nVar==pFrom->nVar );

  83080.   sqlite3_mutex_enter(pTo->db->mutex);

  83081.   for(i=0; i<pFrom->nVar; i++){

  83082.     sqlite3VdbeMemMove(&pTo->aVar[i], &pFrom->aVar[i]);

  83083.   }

  83084.   sqlite3_mutex_leave(pTo->db->mutex);

  83085.   return SQLITE_OK;

  83086. }

  83087. 

  83088. #ifndef SQLITE_OMIT_DEPRECATED

  83089. /*

  83090. ** Deprecated external interface.  Internal/core SQLite code

  83091. ** should call sqlite3TransferBindings.

  83092. **

  83093. ** It is misuse to call this routine with statements from different

  83094. ** database connections.  But as this is a deprecated interface, we

  83095. ** will not bother to check for that condition.

  83096. **

  83097. ** If the two statements contain a different number of bindings, then

  83098. ** an SQLITE_ERROR is returned.  Nothing else can go wrong, so otherwise

  83099. ** SQLITE_OK is returned.

  83100. */

  83101. SQLITE_API int sqlite3_transfer_bindings(sqlite3_stmt *pFromStmt, sqlite3_stmt *pToStmt){

  83102.   Vdbe *pFrom = (Vdbe*)pFromStmt;

  83103.   Vdbe *pTo = (Vdbe*)pToStmt;

  83104.   if( pFrom->nVar!=pTo->nVar ){

  83105.     return SQLITE_ERROR;

  83106.   }

  83107.   assert( (pTo->prepFlags & SQLITE_PREPARE_SAVESQL)!=0 || pTo->expmask==0 );

  83108.   if( pTo->expmask ){

  83109.     pTo->expired = 1;

  83110.   }

  83111.   assert( (pFrom->prepFlags & SQLITE_PREPARE_SAVESQL)!=0 || pFrom->expmask==0 );

  83112.   if( pFrom->expmask ){

  83113.     pFrom->expired = 1;

  83114.   }

  83115.   return sqlite3TransferBindings(pFromStmt, pToStmt);

  83116. }

  83117. #endif

  83118. 

  83119. /*

  83120. ** Return the sqlite3* database handle to which the prepared statement given

  83121. ** in the argument belongs.  This is the same database handle that was

  83122. ** the first argument to the sqlite3_prepare() that was used to create

  83123. ** the statement in the first place.

  83124. */

  83125. SQLITE_API sqlite3 *sqlite3_db_handle(sqlite3_stmt *pStmt){

  83126.   return pStmt ? ((Vdbe*)pStmt)->db : 0;

  83127. }

  83128. 

  83129. /*

  83130. ** Return true if the prepared statement is guaranteed to not modify the

  83131. ** database.

  83132. */

  83133. SQLITE_API int sqlite3_stmt_readonly(sqlite3_stmt *pStmt){

  83134.   return pStmt ? ((Vdbe*)pStmt)->readOnly : 1;

  83135. }

  83136. 

  83137. /*

  83138. ** Return 1 if the statement is an EXPLAIN and return 2 if the

  83139. ** statement is an EXPLAIN QUERY PLAN

  83140. */

  83141. SQLITE_API int sqlite3_stmt_isexplain(sqlite3_stmt *pStmt){

  83142.   return pStmt ? ((Vdbe*)pStmt)->explain : 0;

  83143. }

  83144. 

  83145. /*

  83146. ** Return true if the prepared statement is in need of being reset.

  83147. */

  83148. SQLITE_API int sqlite3_stmt_busy(sqlite3_stmt *pStmt){

  83149.   Vdbe *v = (Vdbe*)pStmt;

  83150.   return v!=0 && v->magic==VDBE_MAGIC_RUN && v->pc>=0;

  83151. }

  83152. 

  83153. /*

  83154. ** Return a pointer to the next prepared statement after pStmt associated

  83155. ** with database connection pDb.  If pStmt is NULL, return the first

  83156. ** prepared statement for the database connection.  Return NULL if there

  83157. ** are no more.

  83158. */

  83159. SQLITE_API sqlite3_stmt *sqlite3_next_stmt(sqlite3 *pDb, sqlite3_stmt *pStmt){

  83160.   sqlite3_stmt *pNext;

  83161. #ifdef SQLITE_ENABLE_API_ARMOR

  83162.   if( !sqlite3SafetyCheckOk(pDb) ){

  83163.     (void)SQLITE_MISUSE_BKPT;

  83164.     return 0;

  83165.   }

  83166. #endif

  83167.   sqlite3_mutex_enter(pDb->mutex);

  83168.   if( pStmt==0 ){

  83169.     pNext = (sqlite3_stmt*)pDb->pVdbe;

  83170.   }else{

  83171.     pNext = (sqlite3_stmt*)((Vdbe*)pStmt)->pNext;

  83172.   }

  83173.   sqlite3_mutex_leave(pDb->mutex);

  83174.   return pNext;

  83175. }

  83176. 

  83177. /*

  83178. ** Return the value of a status counter for a prepared statement

  83179. */

  83180. SQLITE_API int sqlite3_stmt_status(sqlite3_stmt *pStmt, int op, int resetFlag){

  83181.   Vdbe *pVdbe = (Vdbe*)pStmt;

  83182.   u32 v;

  83183. #ifdef SQLITE_ENABLE_API_ARMOR

  83184.   if( !pStmt 

  83185.    || (op!=SQLITE_STMTSTATUS_MEMUSED && (op<0||op>=ArraySize(pVdbe->aCounter)))

  83186.   ){

  83187.     (void)SQLITE_MISUSE_BKPT;

  83188.     return 0;

  83189.   }

  83190. #endif

  83191.   if( op==SQLITE_STMTSTATUS_MEMUSED ){

  83192.     sqlite3 *db = pVdbe->db;

  83193.     sqlite3_mutex_enter(db->mutex);

  83194.     v = 0;

  83195.     db->pnBytesFreed = (int*)&v;

  83196.     sqlite3VdbeClearObject(db, pVdbe);

  83197.     sqlite3DbFree(db, pVdbe);

  83198.     db->pnBytesFreed = 0;

  83199.     sqlite3_mutex_leave(db->mutex);

  83200.   }else{

  83201.     v = pVdbe->aCounter[op];

  83202.     if( resetFlag ) pVdbe->aCounter[op] = 0;

  83203.   }

  83204.   return (int)v;

  83205. }

  83206. 

  83207. /*

  83208. ** Return the SQL associated with a prepared statement

  83209. */

  83210. SQLITE_API const char *sqlite3_sql(sqlite3_stmt *pStmt){

  83211.   Vdbe *p = (Vdbe *)pStmt;

  83212.   return p ? p->zSql : 0;

  83213. }

  83214. 

  83215. /*

  83216. ** Return the SQL associated with a prepared statement with

  83217. ** bound parameters expanded.  Space to hold the returned string is

  83218. ** obtained from sqlite3_malloc().  The caller is responsible for

  83219. ** freeing the returned string by passing it to sqlite3_free().

  83220. **

  83221. ** The SQLITE_TRACE_SIZE_LIMIT puts an upper bound on the size of

  83222. ** expanded bound parameters.

  83223. */

  83224. SQLITE_API char *sqlite3_expanded_sql(sqlite3_stmt *pStmt){

  83225. #ifdef SQLITE_OMIT_TRACE

  83226.   return 0;

  83227. #else

  83228.   char *z = 0;

  83229.   const char *zSql = sqlite3_sql(pStmt);

  83230.   if( zSql ){

  83231.     Vdbe *p = (Vdbe *)pStmt;

  83232.     sqlite3_mutex_enter(p->db->mutex);

  83233.     z = sqlite3VdbeExpandSql(p, zSql);

  83234.     sqlite3_mutex_leave(p->db->mutex);

  83235.   }

  83236.   return z;

  83237. #endif

  83238. }

  83239. 

  83240. #ifdef SQLITE_ENABLE_NORMALIZE

  83241. /*

  83242. ** Return the normalized SQL associated with a prepared statement.

  83243. */

  83244. SQLITE_API const char *sqlite3_normalized_sql(sqlite3_stmt *pStmt){

  83245.   Vdbe *p = (Vdbe *)pStmt;

  83246.   if( p==0 ) return 0;

  83247.   if( p->zNormSql==0 && ALWAYS(p->zSql!=0) ){

  83248.     sqlite3_mutex_enter(p->db->mutex);

  83249.     p->zNormSql = sqlite3Normalize(p, p->zSql);

  83250.     sqlite3_mutex_leave(p->db->mutex);

  83251.   }

  83252.   return p->zNormSql;

  83253. }

  83254. #endif /* SQLITE_ENABLE_NORMALIZE */

  83255. 

  83256. #ifdef SQLITE_ENABLE_PREUPDATE_HOOK

  83257. /*

  83258. ** Allocate and populate an UnpackedRecord structure based on the serialized

  83259. ** record in nKey/pKey. Return a pointer to the new UnpackedRecord structure

  83260. ** if successful, or a NULL pointer if an OOM error is encountered.

  83261. */

  83262. static UnpackedRecord *vdbeUnpackRecord(

  83263.   KeyInfo *pKeyInfo, 

  83264.   int nKey, 

  83265.   const void *pKey

  83266. ){

  83267.   UnpackedRecord *pRet;           /* Return value */

  83268. 

  83269.   pRet = sqlite3VdbeAllocUnpackedRecord(pKeyInfo);

  83270.   if( pRet ){

  83271.     memset(pRet->aMem, 0, sizeof(Mem)*(pKeyInfo->nKeyField+1));

  83272.     sqlite3VdbeRecordUnpack(pKeyInfo, nKey, pKey, pRet);

  83273.   }

  83274.   return pRet;

  83275. }

  83276. 

  83277. /*

  83278. ** This function is called from within a pre-update callback to retrieve

  83279. ** a field of the row currently being updated or deleted.

  83280. */

  83281. SQLITE_API int sqlite3_preupdate_old(sqlite3 *db, int iIdx, sqlite3_value **ppValue){

  83282.   PreUpdate *p = db->pPreUpdate;

  83283.   Mem *pMem;

  83284.   int rc = SQLITE_OK;

  83285. 

  83286.   /* Test that this call is being made from within an SQLITE_DELETE or

  83287.   ** SQLITE_UPDATE pre-update callback, and that iIdx is within range. */

  83288.   if( !p || p->op==SQLITE_INSERT ){

  83289.     rc = SQLITE_MISUSE_BKPT;

  83290.     goto preupdate_old_out;

  83291.   }

  83292.   if( p->pPk ){

  83293.     iIdx = sqlite3ColumnOfIndex(p->pPk, iIdx);

  83294.   }

  83295.   if( iIdx>=p->pCsr->nField || iIdx<0 ){

  83296.     rc = SQLITE_RANGE;

  83297.     goto preupdate_old_out;

  83298.   }

  83299. 

  83300.   /* If the old.* record has not yet been loaded into memory, do so now. */

  83301.   if( p->pUnpacked==0 ){

  83302.     u32 nRec;

  83303.     u8 *aRec;

  83304. 

  83305.     nRec = sqlite3BtreePayloadSize(p->pCsr->uc.pCursor);

  83306.     aRec = sqlite3DbMallocRaw(db, nRec);

  83307.     if( !aRec ) goto preupdate_old_out;

  83308.     rc = sqlite3BtreePayload(p->pCsr->uc.pCursor, 0, nRec, aRec);

  83309.     if( rc==SQLITE_OK ){

  83310.       p->pUnpacked = vdbeUnpackRecord(&p->keyinfo, nRec, aRec);

  83311.       if( !p->pUnpacked ) rc = SQLITE_NOMEM;

  83312.     }

  83313.     if( rc!=SQLITE_OK ){

  83314.       sqlite3DbFree(db, aRec);

  83315.       goto preupdate_old_out;

  83316.     }

  83317.     p->aRecord = aRec;

  83318.   }

  83319. 

  83320.   pMem = *ppValue = &p->pUnpacked->aMem[iIdx];

  83321.   if( iIdx==p->pTab->iPKey ){

  83322.     sqlite3VdbeMemSetInt64(pMem, p->iKey1);

  83323.   }else if( iIdx>=p->pUnpacked->nField ){

  83324.     *ppValue = (sqlite3_value *)columnNullValue();

  83325.   }else if( p->pTab->aCol[iIdx].affinity==SQLITE_AFF_REAL ){

  83326.     if( pMem->flags & (MEM_Int|MEM_IntReal) ){

  83327.       testcase( pMem->flags & MEM_Int );

  83328.       testcase( pMem->flags & MEM_IntReal );

  83329.       sqlite3VdbeMemRealify(pMem);

  83330.     }

  83331.   }

  83332. 

  83333.  preupdate_old_out:

  83334.   sqlite3Error(db, rc);

  83335.   return sqlite3ApiExit(db, rc);

  83336. }

  83337. #endif /* SQLITE_ENABLE_PREUPDATE_HOOK */

  83338. 

  83339. #ifdef SQLITE_ENABLE_PREUPDATE_HOOK

  83340. /*

  83341. ** This function is called from within a pre-update callback to retrieve

  83342. ** the number of columns in the row being updated, deleted or inserted.

  83343. */

  83344. SQLITE_API int sqlite3_preupdate_count(sqlite3 *db){

  83345.   PreUpdate *p = db->pPreUpdate;

  83346.   return (p ? p->keyinfo.nKeyField : 0);

  83347. }

  83348. #endif /* SQLITE_ENABLE_PREUPDATE_HOOK */

  83349. 

  83350. #ifdef SQLITE_ENABLE_PREUPDATE_HOOK

  83351. /*

  83352. ** This function is designed to be called from within a pre-update callback

  83353. ** only. It returns zero if the change that caused the callback was made

  83354. ** immediately by a user SQL statement. Or, if the change was made by a

  83355. ** trigger program, it returns the number of trigger programs currently

  83356. ** on the stack (1 for a top-level trigger, 2 for a trigger fired by a 

  83357. ** top-level trigger etc.).

  83358. **

  83359. ** For the purposes of the previous paragraph, a foreign key CASCADE, SET NULL

  83360. ** or SET DEFAULT action is considered a trigger.

  83361. */

  83362. SQLITE_API int sqlite3_preupdate_depth(sqlite3 *db){

  83363.   PreUpdate *p = db->pPreUpdate;

  83364.   return (p ? p->v->nFrame : 0);

  83365. }

  83366. #endif /* SQLITE_ENABLE_PREUPDATE_HOOK */

  83367. 

  83368. #ifdef SQLITE_ENABLE_PREUPDATE_HOOK

  83369. /*

  83370. ** This function is called from within a pre-update callback to retrieve

  83371. ** a field of the row currently being updated or inserted.

  83372. */

  83373. SQLITE_API int sqlite3_preupdate_new(sqlite3 *db, int iIdx, sqlite3_value **ppValue){

  83374.   PreUpdate *p = db->pPreUpdate;

  83375.   int rc = SQLITE_OK;

  83376.   Mem *pMem;

  83377. 

  83378.   if( !p || p->op==SQLITE_DELETE ){

  83379.     rc = SQLITE_MISUSE_BKPT;

  83380.     goto preupdate_new_out;

  83381.   }

  83382.   if( p->pPk && p->op!=SQLITE_UPDATE ){

  83383.     iIdx = sqlite3ColumnOfIndex(p->pPk, iIdx);

  83384.   }

  83385.   if( iIdx>=p->pCsr->nField || iIdx<0 ){

  83386.     rc = SQLITE_RANGE;

  83387.     goto preupdate_new_out;

  83388.   }

  83389. 

  83390.   if( p->op==SQLITE_INSERT ){

  83391.     /* For an INSERT, memory cell p->iNewReg contains the serialized record

  83392.     ** that is being inserted. Deserialize it. */

  83393.     UnpackedRecord *pUnpack = p->pNewUnpacked;

  83394.     if( !pUnpack ){

  83395.       Mem *pData = &p->v->aMem[p->iNewReg];

  83396.       rc = ExpandBlob(pData);

  83397.       if( rc!=SQLITE_OK ) goto preupdate_new_out;

  83398.       pUnpack = vdbeUnpackRecord(&p->keyinfo, pData->n, pData->z);

  83399.       if( !pUnpack ){

  83400.         rc = SQLITE_NOMEM;

  83401.         goto preupdate_new_out;

  83402.       }

  83403.       p->pNewUnpacked = pUnpack;

  83404.     }

  83405.     pMem = &pUnpack->aMem[iIdx];

  83406.     if( iIdx==p->pTab->iPKey ){

  83407.       sqlite3VdbeMemSetInt64(pMem, p->iKey2);

  83408.     }else if( iIdx>=pUnpack->nField ){

  83409.       pMem = (sqlite3_value *)columnNullValue();

  83410.     }

  83411.   }else{

  83412.     /* For an UPDATE, memory cell (p->iNewReg+1+iIdx) contains the required

  83413.     ** value. Make a copy of the cell contents and return a pointer to it.

  83414.     ** It is not safe to return a pointer to the memory cell itself as the

  83415.     ** caller may modify the value text encoding.

  83416.     */

  83417.     assert( p->op==SQLITE_UPDATE );

  83418.     if( !p->aNew ){

  83419.       p->aNew = (Mem *)sqlite3DbMallocZero(db, sizeof(Mem) * p->pCsr->nField);

  83420.       if( !p->aNew ){

  83421.         rc = SQLITE_NOMEM;

  83422.         goto preupdate_new_out;

  83423.       }

  83424.     }

  83425.     assert( iIdx>=0 && iIdx<p->pCsr->nField );

  83426.     pMem = &p->aNew[iIdx];

  83427.     if( pMem->flags==0 ){

  83428.       if( iIdx==p->pTab->iPKey ){

  83429.         sqlite3VdbeMemSetInt64(pMem, p->iKey2);

  83430.       }else{

  83431.         rc = sqlite3VdbeMemCopy(pMem, &p->v->aMem[p->iNewReg+1+iIdx]);

  83432.         if( rc!=SQLITE_OK ) goto preupdate_new_out;

  83433.       }

  83434.     }

  83435.   }

  83436.   *ppValue = pMem;

  83437. 

  83438.  preupdate_new_out:

  83439.   sqlite3Error(db, rc);

  83440.   return sqlite3ApiExit(db, rc);

  83441. }

  83442. #endif /* SQLITE_ENABLE_PREUPDATE_HOOK */

  83443. 

  83444. #ifdef SQLITE_ENABLE_STMT_SCANSTATUS

  83445. /*

  83446. ** Return status data for a single loop within query pStmt.

  83447. */

  83448. SQLITE_API int sqlite3_stmt_scanstatus(

  83449.   sqlite3_stmt *pStmt,            /* Prepared statement being queried */

  83450.   int idx,                        /* Index of loop to report on */

  83451.   int iScanStatusOp,              /* Which metric to return */

  83452.   void *pOut                      /* OUT: Write the answer here */

  83453. ){

  83454.   Vdbe *p = (Vdbe*)pStmt;

  83455.   ScanStatus *pScan;

  83456.   if( idx<0 || idx>=p->nScan ) return 1;

  83457.   pScan = &p->aScan[idx];

  83458.   switch( iScanStatusOp ){

  83459.     case SQLITE_SCANSTAT_NLOOP: {

  83460.       *(sqlite3_int64*)pOut = p->anExec[pScan->addrLoop];

  83461.       break;

  83462.     }

  83463.     case SQLITE_SCANSTAT_NVISIT: {

  83464.       *(sqlite3_int64*)pOut = p->anExec[pScan->addrVisit];

  83465.       break;

  83466.     }

  83467.     case SQLITE_SCANSTAT_EST: {

  83468.       double r = 1.0;

  83469.       LogEst x = pScan->nEst;

  83470.       while( x<100 ){

  83471.         x += 10;

  83472.         r *= 0.5;

  83473.       }

  83474.       *(double*)pOut = r*sqlite3LogEstToInt(x);

  83475.       break;

  83476.     }

  83477.     case SQLITE_SCANSTAT_NAME: {

  83478.       *(const char**)pOut = pScan->zName;

  83479.       break;

  83480.     }

  83481.     case SQLITE_SCANSTAT_EXPLAIN: {

  83482.       if( pScan->addrExplain ){

  83483.         *(const char**)pOut = p->aOp[ pScan->addrExplain ].p4.z;

  83484.       }else{

  83485.         *(const char**)pOut = 0;

  83486.       }

  83487.       break;

  83488.     }

  83489.     case SQLITE_SCANSTAT_SELECTID: {

  83490.       if( pScan->addrExplain ){

  83491.         *(int*)pOut = p->aOp[ pScan->addrExplain ].p1;

  83492.       }else{

  83493.         *(int*)pOut = -1;

  83494.       }

  83495.       break;

  83496.     }

  83497.     default: {

  83498.       return 1;

  83499.     }

  83500.   }

  83501.   return 0;

  83502. }

  83503. 

  83504. /*

  83505. ** Zero all counters associated with the sqlite3_stmt_scanstatus() data.

  83506. */

  83507. SQLITE_API void sqlite3_stmt_scanstatus_reset(sqlite3_stmt *pStmt){

  83508.   Vdbe *p = (Vdbe*)pStmt;

  83509.   memset(p->anExec, 0, p->nOp * sizeof(i64));

  83510. }

  83511. #endif /* SQLITE_ENABLE_STMT_SCANSTATUS */

  83512. 

  83513. /************** End of vdbeapi.c *********************************************/

  83514. /************** Begin file vdbetrace.c ***************************************/

  83515. /*

  83516. ** 2009 November 25

  83517. **

  83518. ** The author disclaims copyright to this source code.  In place of

  83519. ** a legal notice, here is a blessing:

  83520. **

  83521. **    May you do good and not evil.

  83522. **    May you find forgiveness for yourself and forgive others.

  83523. **    May you share freely, never taking more than you give.

  83524. **

  83525. *************************************************************************

  83526. **

  83527. ** This file contains code used to insert the values of host parameters

  83528. ** (aka "wildcards") into the SQL text output by sqlite3_trace().

  83529. **

  83530. ** The Vdbe parse-tree explainer is also found here.

  83531. */

  83532. /* #include "sqliteInt.h" */

  83533. /* #include "vdbeInt.h" */

  83534. 

  83535. #ifndef SQLITE_OMIT_TRACE

  83536. 

  83537. /*

  83538. ** zSql is a zero-terminated string of UTF-8 SQL text.  Return the number of

  83539. ** bytes in this text up to but excluding the first character in

  83540. ** a host parameter.  If the text contains no host parameters, return

  83541. ** the total number of bytes in the text.

  83542. */

  83543. static int findNextHostParameter(const char *zSql, int *pnToken){

  83544.   int tokenType;

  83545.   int nTotal = 0;

  83546.   int n;

  83547. 

  83548.   *pnToken = 0;

  83549.   while( zSql[0] ){

  83550.     n = sqlite3GetToken((u8*)zSql, &tokenType);

  83551.     assert( n>0 && tokenType!=TK_ILLEGAL );

  83552.     if( tokenType==TK_VARIABLE ){

  83553.       *pnToken = n;

  83554.       break;

  83555.     }

  83556.     nTotal += n;

  83557.     zSql += n;

  83558.   }

  83559.   return nTotal;

  83560. }

  83561. 

  83562. /*

  83563. ** This function returns a pointer to a nul-terminated string in memory

  83564. ** obtained from sqlite3DbMalloc(). If sqlite3.nVdbeExec is 1, then the

  83565. ** string contains a copy of zRawSql but with host parameters expanded to 

  83566. ** their current bindings. Or, if sqlite3.nVdbeExec is greater than 1, 

  83567. ** then the returned string holds a copy of zRawSql with "-- " prepended

  83568. ** to each line of text.

  83569. **

  83570. ** If the SQLITE_TRACE_SIZE_LIMIT macro is defined to an integer, then

  83571. ** then long strings and blobs are truncated to that many bytes.  This

  83572. ** can be used to prevent unreasonably large trace strings when dealing

  83573. ** with large (multi-megabyte) strings and blobs.

  83574. **

  83575. ** The calling function is responsible for making sure the memory returned

  83576. ** is eventually freed.

  83577. **

  83578. ** ALGORITHM:  Scan the input string looking for host parameters in any of

  83579. ** these forms:  ?, ?N, $A, @A, :A.  Take care to avoid text within

  83580. ** string literals, quoted identifier names, and comments.  For text forms,

  83581. ** the host parameter index is found by scanning the prepared

  83582. ** statement for the corresponding OP_Variable opcode.  Once the host

  83583. ** parameter index is known, locate the value in p->aVar[].  Then render

  83584. ** the value as a literal in place of the host parameter name.

  83585. */

  83586. SQLITE_PRIVATE char *sqlite3VdbeExpandSql(

  83587.   Vdbe *p,                 /* The prepared statement being evaluated */

  83588.   const char *zRawSql      /* Raw text of the SQL statement */

  83589. ){

  83590.   sqlite3 *db;             /* The database connection */

  83591.   int idx = 0;             /* Index of a host parameter */

  83592.   int nextIndex = 1;       /* Index of next ? host parameter */

  83593.   int n;                   /* Length of a token prefix */

  83594.   int nToken;              /* Length of the parameter token */

  83595.   int i;                   /* Loop counter */

  83596.   Mem *pVar;               /* Value of a host parameter */

  83597.   StrAccum out;            /* Accumulate the output here */

  83598. #ifndef SQLITE_OMIT_UTF16

  83599.   Mem utf8;                /* Used to convert UTF16 into UTF8 for display */

  83600. #endif

  83601.   char zBase[100];         /* Initial working space */

  83602. 

  83603.   db = p->db;

  83604.   sqlite3StrAccumInit(&out, 0, zBase, sizeof(zBase), 

  83605.                       db->aLimit[SQLITE_LIMIT_LENGTH]);

  83606.   if( db->nVdbeExec>1 ){

  83607.     while( *zRawSql ){

  83608.       const char *zStart = zRawSql;

  83609.       while( *(zRawSql++)!='\n' && *zRawSql );

  83610.       sqlite3_str_append(&out, "-- ", 3);

  83611.       assert( (zRawSql - zStart) > 0 );

  83612.       sqlite3_str_append(&out, zStart, (int)(zRawSql-zStart));

  83613.     }

  83614.   }else if( p->nVar==0 ){

  83615.     sqlite3_str_append(&out, zRawSql, sqlite3Strlen30(zRawSql));

  83616.   }else{

  83617.     while( zRawSql[0] ){

  83618.       n = findNextHostParameter(zRawSql, &nToken);

  83619.       assert( n>0 );

  83620.       sqlite3_str_append(&out, zRawSql, n);

  83621.       zRawSql += n;

  83622.       assert( zRawSql[0] || nToken==0 );

  83623.       if( nToken==0 ) break;

  83624.       if( zRawSql[0]=='?' ){

  83625.         if( nToken>1 ){

  83626.           assert( sqlite3Isdigit(zRawSql[1]) );

  83627.           sqlite3GetInt32(&zRawSql[1], &idx);

  83628.         }else{

  83629.           idx = nextIndex;

  83630.         }

  83631.       }else{

  83632.         assert( zRawSql[0]==':' || zRawSql[0]=='$' ||

  83633.                 zRawSql[0]=='@' || zRawSql[0]=='#' );

  83634.         testcase( zRawSql[0]==':' );

  83635.         testcase( zRawSql[0]=='$' );

  83636.         testcase( zRawSql[0]=='@' );

  83637.         testcase( zRawSql[0]=='#' );

  83638.         idx = sqlite3VdbeParameterIndex(p, zRawSql, nToken);

  83639.         assert( idx>0 );

  83640.       }

  83641.       zRawSql += nToken;

  83642.       nextIndex = idx + 1;

  83643.       assert( idx>0 && idx<=p->nVar );

  83644.       pVar = &p->aVar[idx-1];

  83645.       if( pVar->flags & MEM_Null ){

  83646.         sqlite3_str_append(&out, "NULL", 4);

  83647.       }else if( pVar->flags & (MEM_Int|MEM_IntReal) ){

  83648.         sqlite3_str_appendf(&out, "%lld", pVar->u.i);

  83649.       }else if( pVar->flags & MEM_Real ){

  83650.         sqlite3_str_appendf(&out, "%!.15g", pVar->u.r);

  83651.       }else if( pVar->flags & MEM_Str ){

  83652.         int nOut;  /* Number of bytes of the string text to include in output */

  83653. #ifndef SQLITE_OMIT_UTF16

  83654.         u8 enc = ENC(db);

  83655.         if( enc!=SQLITE_UTF8 ){

  83656.           memset(&utf8, 0, sizeof(utf8));

  83657.           utf8.db = db;

  83658.           sqlite3VdbeMemSetStr(&utf8, pVar->z, pVar->n, enc, SQLITE_STATIC);

  83659.           if( SQLITE_NOMEM==sqlite3VdbeChangeEncoding(&utf8, SQLITE_UTF8) ){

  83660.             out.accError = SQLITE_NOMEM;

  83661.             out.nAlloc = 0;

  83662.           }

  83663.           pVar = &utf8;

  83664.         }

  83665. #endif

  83666.         nOut = pVar->n;

  83667. #ifdef SQLITE_TRACE_SIZE_LIMIT

  83668.         if( nOut>SQLITE_TRACE_SIZE_LIMIT ){

  83669.           nOut = SQLITE_TRACE_SIZE_LIMIT;

  83670.           while( nOut<pVar->n && (pVar->z[nOut]&0xc0)==0x80 ){ nOut++; }

  83671.         }

  83672. #endif    

  83673.         sqlite3_str_appendf(&out, "'%.*q'", nOut, pVar->z);

  83674. #ifdef SQLITE_TRACE_SIZE_LIMIT

  83675.         if( nOut<pVar->n ){

  83676.           sqlite3_str_appendf(&out, "/*+%d bytes*/", pVar->n-nOut);

  83677.         }

  83678. #endif

  83679. #ifndef SQLITE_OMIT_UTF16

  83680.         if( enc!=SQLITE_UTF8 ) sqlite3VdbeMemRelease(&utf8);

  83681. #endif

  83682.       }else if( pVar->flags & MEM_Zero ){

  83683.         sqlite3_str_appendf(&out, "zeroblob(%d)", pVar->u.nZero);

  83684.       }else{

  83685.         int nOut;  /* Number of bytes of the blob to include in output */

  83686.         assert( pVar->flags & MEM_Blob );

  83687.         sqlite3_str_append(&out, "x'", 2);

  83688.         nOut = pVar->n;

  83689. #ifdef SQLITE_TRACE_SIZE_LIMIT

  83690.         if( nOut>SQLITE_TRACE_SIZE_LIMIT ) nOut = SQLITE_TRACE_SIZE_LIMIT;

  83691. #endif

  83692.         for(i=0; i<nOut; i++){

  83693.           sqlite3_str_appendf(&out, "%02x", pVar->z[i]&0xff);

  83694.         }

  83695.         sqlite3_str_append(&out, "'", 1);

  83696. #ifdef SQLITE_TRACE_SIZE_LIMIT

  83697.         if( nOut<pVar->n ){

  83698.           sqlite3_str_appendf(&out, "/*+%d bytes*/", pVar->n-nOut);

  83699.         }

  83700. #endif

  83701.       }

  83702.     }

  83703.   }

  83704.   if( out.accError ) sqlite3_str_reset(&out);

  83705.   return sqlite3StrAccumFinish(&out);

  83706. }

  83707. 

  83708. #endif /* #ifndef SQLITE_OMIT_TRACE */

  83709. 

  83710. /************** End of vdbetrace.c *******************************************/

  83711. /************** Begin file vdbe.c ********************************************/

  83712. /*

  83713. ** 2001 September 15

  83714. **

  83715. ** The author disclaims copyright to this source code.  In place of

  83716. ** a legal notice, here is a blessing:

  83717. **

  83718. **    May you do good and not evil.

  83719. **    May you find forgiveness for yourself and forgive others.

  83720. **    May you share freely, never taking more than you give.

  83721. **

  83722. *************************************************************************

  83723. ** The code in this file implements the function that runs the

  83724. ** bytecode of a prepared statement.

  83725. **

  83726. ** Various scripts scan this source file in order to generate HTML

  83727. ** documentation, headers files, or other derived files.  The formatting

  83728. ** of the code in this file is, therefore, important.  See other comments

  83729. ** in this file for details.  If in doubt, do not deviate from existing

  83730. ** commenting and indentation practices when changing or adding code.

  83731. */

  83732. /* #include "sqliteInt.h" */

  83733. /* #include "vdbeInt.h" */

  83734. 

  83735. /*

  83736. ** Invoke this macro on memory cells just prior to changing the

  83737. ** value of the cell.  This macro verifies that shallow copies are

  83738. ** not misused.  A shallow copy of a string or blob just copies a

  83739. ** pointer to the string or blob, not the content.  If the original

  83740. ** is changed while the copy is still in use, the string or blob might

  83741. ** be changed out from under the copy.  This macro verifies that nothing

  83742. ** like that ever happens.

  83743. */

  83744. #ifdef SQLITE_DEBUG

  83745. # define memAboutToChange(P,M) sqlite3VdbeMemAboutToChange(P,M)

  83746. #else

  83747. # define memAboutToChange(P,M)

  83748. #endif

  83749. 

  83750. /*

  83751. ** The following global variable is incremented every time a cursor

  83752. ** moves, either by the OP_SeekXX, OP_Next, or OP_Prev opcodes.  The test

  83753. ** procedures use this information to make sure that indices are

  83754. ** working correctly.  This variable has no function other than to

  83755. ** help verify the correct operation of the library.

  83756. */

  83757. #ifdef SQLITE_TEST

  83758. SQLITE_API int sqlite3_search_count = 0;

  83759. #endif

  83760. 

  83761. /*

  83762. ** When this global variable is positive, it gets decremented once before

  83763. ** each instruction in the VDBE.  When it reaches zero, the u1.isInterrupted

  83764. ** field of the sqlite3 structure is set in order to simulate an interrupt.

  83765. **

  83766. ** This facility is used for testing purposes only.  It does not function

  83767. ** in an ordinary build.

  83768. */

  83769. #ifdef SQLITE_TEST

  83770. SQLITE_API int sqlite3_interrupt_count = 0;

  83771. #endif

  83772. 

  83773. /*

  83774. ** The next global variable is incremented each type the OP_Sort opcode

  83775. ** is executed.  The test procedures use this information to make sure that

  83776. ** sorting is occurring or not occurring at appropriate times.   This variable

  83777. ** has no function other than to help verify the correct operation of the

  83778. ** library.

  83779. */

  83780. #ifdef SQLITE_TEST

  83781. SQLITE_API int sqlite3_sort_count = 0;

  83782. #endif

  83783. 

  83784. /*

  83785. ** The next global variable records the size of the largest MEM_Blob

  83786. ** or MEM_Str that has been used by a VDBE opcode.  The test procedures

  83787. ** use this information to make sure that the zero-blob functionality

  83788. ** is working correctly.   This variable has no function other than to

  83789. ** help verify the correct operation of the library.

  83790. */

  83791. #ifdef SQLITE_TEST

  83792. SQLITE_API int sqlite3_max_blobsize = 0;

  83793. static void updateMaxBlobsize(Mem *p){

  83794.   if( (p->flags & (MEM_Str|MEM_Blob))!=0 && p->n>sqlite3_max_blobsize ){

  83795.     sqlite3_max_blobsize = p->n;

  83796.   }

  83797. }

  83798. #endif

  83799. 

  83800. /*

  83801. ** This macro evaluates to true if either the update hook or the preupdate

  83802. ** hook are enabled for database connect DB.

  83803. */

  83804. #ifdef SQLITE_ENABLE_PREUPDATE_HOOK

  83805. # define HAS_UPDATE_HOOK(DB) ((DB)->xPreUpdateCallback||(DB)->xUpdateCallback)

  83806. #else

  83807. # define HAS_UPDATE_HOOK(DB) ((DB)->xUpdateCallback)

  83808. #endif

  83809. 

  83810. /*

  83811. ** The next global variable is incremented each time the OP_Found opcode

  83812. ** is executed. This is used to test whether or not the foreign key

  83813. ** operation implemented using OP_FkIsZero is working. This variable

  83814. ** has no function other than to help verify the correct operation of the

  83815. ** library.

  83816. */

  83817. #ifdef SQLITE_TEST

  83818. SQLITE_API int sqlite3_found_count = 0;

  83819. #endif

  83820. 

  83821. /*

  83822. ** Test a register to see if it exceeds the current maximum blob size.

  83823. ** If it does, record the new maximum blob size.

  83824. */

  83825. #if defined(SQLITE_TEST) && !defined(SQLITE_UNTESTABLE)

  83826. # define UPDATE_MAX_BLOBSIZE(P)  updateMaxBlobsize(P)

  83827. #else

  83828. # define UPDATE_MAX_BLOBSIZE(P)

  83829. #endif

  83830. 

  83831. /*

  83832. ** Invoke the VDBE coverage callback, if that callback is defined.  This

  83833. ** feature is used for test suite validation only and does not appear an

  83834. ** production builds.

  83835. **

  83836. ** M is the type of branch.  I is the direction taken for this instance of

  83837. ** the branch.

  83838. **

  83839. **   M: 2 - two-way branch (I=0: fall-thru   1: jump                )

  83840. **      3 - two-way + NULL (I=0: fall-thru   1: jump      2: NULL   )

  83841. **      4 - OP_Jump        (I=0: jump p1     1: jump p2   2: jump p3)

  83842. **

  83843. ** In other words, if M is 2, then I is either 0 (for fall-through) or

  83844. ** 1 (for when the branch is taken).  If M is 3, the I is 0 for an

  83845. ** ordinary fall-through, I is 1 if the branch was taken, and I is 2 

  83846. ** if the result of comparison is NULL.  For M=3, I=2 the jump may or

  83847. ** may not be taken, depending on the SQLITE_JUMPIFNULL flags in p5.

  83848. ** When M is 4, that means that an OP_Jump is being run.  I is 0, 1, or 2

  83849. ** depending on if the operands are less than, equal, or greater than.

  83850. **

  83851. ** iSrcLine is the source code line (from the __LINE__ macro) that

  83852. ** generated the VDBE instruction combined with flag bits.  The source

  83853. ** code line number is in the lower 24 bits of iSrcLine and the upper

  83854. ** 8 bytes are flags.  The lower three bits of the flags indicate

  83855. ** values for I that should never occur.  For example, if the branch is

  83856. ** always taken, the flags should be 0x05 since the fall-through and

  83857. ** alternate branch are never taken.  If a branch is never taken then

  83858. ** flags should be 0x06 since only the fall-through approach is allowed.

  83859. **

  83860. ** Bit 0x08 of the flags indicates an OP_Jump opcode that is only

  83861. ** interested in equal or not-equal.  In other words, I==0 and I==2

  83862. ** should be treated as equivalent

  83863. **

  83864. ** Since only a line number is retained, not the filename, this macro

  83865. ** only works for amalgamation builds.  But that is ok, since these macros

  83866. ** should be no-ops except for special builds used to measure test coverage.

  83867. */

  83868. #if !defined(SQLITE_VDBE_COVERAGE)

  83869. # define VdbeBranchTaken(I,M)

  83870. #else

  83871. # define VdbeBranchTaken(I,M) vdbeTakeBranch(pOp->iSrcLine,I,M)

  83872.   static void vdbeTakeBranch(u32 iSrcLine, u8 I, u8 M){

  83873.     u8 mNever;

  83874.     assert( I<=2 );  /* 0: fall through,  1: taken,  2: alternate taken */

  83875.     assert( M<=4 );  /* 2: two-way branch, 3: three-way branch, 4: OP_Jump */

  83876.     assert( I<M );   /* I can only be 2 if M is 3 or 4 */

  83877.     /* Transform I from a integer [0,1,2] into a bitmask of [1,2,4] */

  83878.     I = 1<<I;

  83879.     /* The upper 8 bits of iSrcLine are flags.  The lower three bits of

  83880.     ** the flags indicate directions that the branch can never go.  If

  83881.     ** a branch really does go in one of those directions, assert right

  83882.     ** away. */

  83883.     mNever = iSrcLine >> 24;

  83884.     assert( (I & mNever)==0 );

  83885.     if( sqlite3GlobalConfig.xVdbeBranch==0 ) return;  /*NO_TEST*/

  83886.     /* Invoke the branch coverage callback with three arguments:

  83887.     **    iSrcLine - the line number of the VdbeCoverage() macro, with

  83888.     **               flags removed.

  83889.     **    I        - Mask of bits 0x07 indicating which cases are are

  83890.     **               fulfilled by this instance of the jump.  0x01 means

  83891.     **               fall-thru, 0x02 means taken, 0x04 means NULL.  Any

  83892.     **               impossible cases (ex: if the comparison is never NULL)

  83893.     **               are filled in automatically so that the coverage

  83894.     **               measurement logic does not flag those impossible cases

  83895.     **               as missed coverage.

  83896.     **    M        - Type of jump.  Same as M argument above

  83897.     */

  83898.     I |= mNever;

  83899.     if( M==2 ) I |= 0x04;

  83900.     if( M==4 ){

  83901.       I |= 0x08;

  83902.       if( (mNever&0x08)!=0 && (I&0x05)!=0) I |= 0x05; /*NO_TEST*/

  83903.     }

  83904.     sqlite3GlobalConfig.xVdbeBranch(sqlite3GlobalConfig.pVdbeBranchArg,

  83905.                                     iSrcLine&0xffffff, I, M);

  83906.   }

  83907. #endif

  83908. 

  83909. /*

  83910. ** An ephemeral string value (signified by the MEM_Ephem flag) contains

  83911. ** a pointer to a dynamically allocated string where some other entity

  83912. ** is responsible for deallocating that string.  Because the register

  83913. ** does not control the string, it might be deleted without the register

  83914. ** knowing it.

  83915. **

  83916. ** This routine converts an ephemeral string into a dynamically allocated

  83917. ** string that the register itself controls.  In other words, it

  83918. ** converts an MEM_Ephem string into a string with P.z==P.zMalloc.

  83919. */

  83920. #define Deephemeralize(P) \

  83921.    if( ((P)->flags&MEM_Ephem)!=0 \

  83922.        && sqlite3VdbeMemMakeWriteable(P) ){ goto no_mem;}

  83923. 

  83924. /* Return true if the cursor was opened using the OP_OpenSorter opcode. */

  83925. #define isSorter(x) ((x)->eCurType==CURTYPE_SORTER)

  83926. 

  83927. /*

  83928. ** Allocate VdbeCursor number iCur.  Return a pointer to it.  Return NULL

  83929. ** if we run out of memory.

  83930. */

  83931. static VdbeCursor *allocateCursor(

  83932.   Vdbe *p,              /* The virtual machine */

  83933.   int iCur,             /* Index of the new VdbeCursor */

  83934.   int nField,           /* Number of fields in the table or index */

  83935.   int iDb,              /* Database the cursor belongs to, or -1 */

  83936.   u8 eCurType           /* Type of the new cursor */

  83937. ){

  83938.   /* Find the memory cell that will be used to store the blob of memory

  83939.   ** required for this VdbeCursor structure. It is convenient to use a 

  83940.   ** vdbe memory cell to manage the memory allocation required for a

  83941.   ** VdbeCursor structure for the following reasons:

  83942.   **

  83943.   **   * Sometimes cursor numbers are used for a couple of different

  83944.   **     purposes in a vdbe program. The different uses might require

  83945.   **     different sized allocations. Memory cells provide growable

  83946.   **     allocations.

  83947.   **

  83948.   **   * When using ENABLE_MEMORY_MANAGEMENT, memory cell buffers can

  83949.   **     be freed lazily via the sqlite3_release_memory() API. This

  83950.   **     minimizes the number of malloc calls made by the system.

  83951.   **

  83952.   ** The memory cell for cursor 0 is aMem[0]. The rest are allocated from

  83953.   ** the top of the register space.  Cursor 1 is at Mem[p->nMem-1].

  83954.   ** Cursor 2 is at Mem[p->nMem-2]. And so forth.

  83955.   */

  83956.   Mem *pMem = iCur>0 ? &p->aMem[p->nMem-iCur] : p->aMem;

  83957. 

  83958.   int nByte;

  83959.   VdbeCursor *pCx = 0;

  83960.   nByte = 

  83961.       ROUND8(sizeof(VdbeCursor)) + 2*sizeof(u32)*nField + 

  83962.       (eCurType==CURTYPE_BTREE?sqlite3BtreeCursorSize():0);

  83963. 

  83964.   assert( iCur>=0 && iCur<p->nCursor );

  83965.   if( p->apCsr[iCur] ){ /*OPTIMIZATION-IF-FALSE*/

  83966.     /* Before calling sqlite3VdbeFreeCursor(), ensure the isEphemeral flag

  83967.     ** is clear. Otherwise, if this is an ephemeral cursor created by 

  83968.     ** OP_OpenDup, the cursor will not be closed and will still be part

  83969.     ** of a BtShared.pCursor list.  */

  83970.     if( p->apCsr[iCur]->pBtx==0 ) p->apCsr[iCur]->isEphemeral = 0;

  83971.     sqlite3VdbeFreeCursor(p, p->apCsr[iCur]);

  83972.     p->apCsr[iCur] = 0;

  83973.   }

  83974.   if( SQLITE_OK==sqlite3VdbeMemClearAndResize(pMem, nByte) ){

  83975.     p->apCsr[iCur] = pCx = (VdbeCursor*)pMem->z;

  83976.     memset(pCx, 0, offsetof(VdbeCursor,pAltCursor));

  83977.     pCx->eCurType = eCurType;

  83978.     pCx->iDb = iDb;

  83979.     pCx->nField = nField;

  83980.     pCx->aOffset = &pCx->aType[nField];

  83981.     if( eCurType==CURTYPE_BTREE ){

  83982.       pCx->uc.pCursor = (BtCursor*)

  83983.           &pMem->z[ROUND8(sizeof(VdbeCursor))+2*sizeof(u32)*nField];

  83984.       sqlite3BtreeCursorZero(pCx->uc.pCursor);

  83985.     }

  83986.   }

  83987.   return pCx;

  83988. }

  83989. 

  83990. /*

  83991. ** The string in pRec is known to look like an integer and to have a

  83992. ** floating point value of rValue.  Return true and set *piValue to the

  83993. ** integer value if the string is in range to be an integer.  Otherwise,

  83994. ** return false.

  83995. */

  83996. static int alsoAnInt(Mem *pRec, double rValue, i64 *piValue){

  83997.   i64 iValue = (double)rValue;

  83998.   if( sqlite3RealSameAsInt(rValue,iValue) ){

  83999.     *piValue = iValue;

  84000.     return 1;

  84001.   }

  84002.   return 0==sqlite3Atoi64(pRec->z, piValue, pRec->n, pRec->enc);

  84003. }

  84004. 

  84005. /*

  84006. ** Try to convert a value into a numeric representation if we can

  84007. ** do so without loss of information.  In other words, if the string

  84008. ** looks like a number, convert it into a number.  If it does not

  84009. ** look like a number, leave it alone.

  84010. **

  84011. ** If the bTryForInt flag is true, then extra effort is made to give

  84012. ** an integer representation.  Strings that look like floating point

  84013. ** values but which have no fractional component (example: '48.00')

  84014. ** will have a MEM_Int representation when bTryForInt is true.

  84015. **

  84016. ** If bTryForInt is false, then if the input string contains a decimal

  84017. ** point or exponential notation, the result is only MEM_Real, even

  84018. ** if there is an exact integer representation of the quantity.

  84019. */

  84020. static void applyNumericAffinity(Mem *pRec, int bTryForInt){

  84021.   double rValue;

  84022.   u8 enc = pRec->enc;

  84023.   int rc;

  84024.   assert( (pRec->flags & (MEM_Str|MEM_Int|MEM_Real|MEM_IntReal))==MEM_Str );

  84025.   rc = sqlite3AtoF(pRec->z, &rValue, pRec->n, enc);

  84026.   if( rc<=0 ) return;

  84027.   if( rc==1 && alsoAnInt(pRec, rValue, &pRec->u.i) ){

  84028.     pRec->flags |= MEM_Int;

  84029.   }else{

  84030.     pRec->u.r = rValue;

  84031.     pRec->flags |= MEM_Real;

  84032.     if( bTryForInt ) sqlite3VdbeIntegerAffinity(pRec);

  84033.   }

  84034.   /* TEXT->NUMERIC is many->one.  Hence, it is important to invalidate the

  84035.   ** string representation after computing a numeric equivalent, because the

  84036.   ** string representation might not be the canonical representation for the

  84037.   ** numeric value.  Ticket [343634942dd54ab57b7024] 2018-01-31. */

  84038.   pRec->flags &= ~MEM_Str;

  84039. }

  84040. 

  84041. /*

  84042. ** Processing is determine by the affinity parameter:

  84043. **

  84044. ** SQLITE_AFF_INTEGER:

  84045. ** SQLITE_AFF_REAL:

  84046. ** SQLITE_AFF_NUMERIC:

  84047. **    Try to convert pRec to an integer representation or a 

  84048. **    floating-point representation if an integer representation

  84049. **    is not possible.  Note that the integer representation is

  84050. **    always preferred, even if the affinity is REAL, because

  84051. **    an integer representation is more space efficient on disk.

  84052. **

  84053. ** SQLITE_AFF_TEXT:

  84054. **    Convert pRec to a text representation.

  84055. **

  84056. ** SQLITE_AFF_BLOB:

  84057. **    No-op.  pRec is unchanged.

  84058. */

  84059. static void applyAffinity(

  84060.   Mem *pRec,          /* The value to apply affinity to */

  84061.   char affinity,      /* The affinity to be applied */

  84062.   u8 enc              /* Use this text encoding */

  84063. ){

  84064.   if( affinity>=SQLITE_AFF_NUMERIC ){

  84065.     assert( affinity==SQLITE_AFF_INTEGER || affinity==SQLITE_AFF_REAL

  84066.              || affinity==SQLITE_AFF_NUMERIC );

  84067.     if( (pRec->flags & MEM_Int)==0 ){ /*OPTIMIZATION-IF-FALSE*/

  84068.       if( (pRec->flags & MEM_Real)==0 ){

  84069.         if( pRec->flags & MEM_Str ) applyNumericAffinity(pRec,1);

  84070.       }else{

  84071.         sqlite3VdbeIntegerAffinity(pRec);

  84072.       }

  84073.     }

  84074.   }else if( affinity==SQLITE_AFF_TEXT ){

  84075.     /* Only attempt the conversion to TEXT if there is an integer or real

  84076.     ** representation (blob and NULL do not get converted) but no string

  84077.     ** representation.  It would be harmless to repeat the conversion if 

  84078.     ** there is already a string rep, but it is pointless to waste those

  84079.     ** CPU cycles. */

  84080.     if( 0==(pRec->flags&MEM_Str) ){ /*OPTIMIZATION-IF-FALSE*/

  84081.       if( (pRec->flags&(MEM_Real|MEM_Int|MEM_IntReal)) ){

  84082.         testcase( pRec->flags & MEM_Int );

  84083.         testcase( pRec->flags & MEM_Real );

  84084.         testcase( pRec->flags & MEM_IntReal );

  84085.         sqlite3VdbeMemStringify(pRec, enc, 1);

  84086.       }

  84087.     }

  84088.     pRec->flags &= ~(MEM_Real|MEM_Int|MEM_IntReal);

  84089.   }

  84090. }

  84091. 

  84092. /*

  84093. ** Try to convert the type of a function argument or a result column

  84094. ** into a numeric representation.  Use either INTEGER or REAL whichever

  84095. ** is appropriate.  But only do the conversion if it is possible without

  84096. ** loss of information and return the revised type of the argument.

  84097. */

  84098. SQLITE_API int sqlite3_value_numeric_type(sqlite3_value *pVal){

  84099.   int eType = sqlite3_value_type(pVal);

  84100.   if( eType==SQLITE_TEXT ){

  84101.     Mem *pMem = (Mem*)pVal;

  84102.     applyNumericAffinity(pMem, 0);

  84103.     eType = sqlite3_value_type(pVal);

  84104.   }

  84105.   return eType;

  84106. }

  84107. 

  84108. /*

  84109. ** Exported version of applyAffinity(). This one works on sqlite3_value*, 

  84110. ** not the internal Mem* type.

  84111. */

  84112. SQLITE_PRIVATE void sqlite3ValueApplyAffinity(

  84113.   sqlite3_value *pVal, 

  84114.   u8 affinity, 

  84115.   u8 enc

  84116. ){

  84117.   applyAffinity((Mem *)pVal, affinity, enc);

  84118. }

  84119. 

  84120. /*

  84121. ** pMem currently only holds a string type (or maybe a BLOB that we can

  84122. ** interpret as a string if we want to).  Compute its corresponding

  84123. ** numeric type, if has one.  Set the pMem->u.r and pMem->u.i fields

  84124. ** accordingly.

  84125. */

  84126. static u16 SQLITE_NOINLINE computeNumericType(Mem *pMem){

  84127.   int rc;

  84128.   sqlite3_int64 ix;

  84129.   assert( (pMem->flags & (MEM_Int|MEM_Real|MEM_IntReal))==0 );

  84130.   assert( (pMem->flags & (MEM_Str|MEM_Blob))!=0 );

  84131.   ExpandBlob(pMem);

  84132.   rc = sqlite3AtoF(pMem->z, &pMem->u.r, pMem->n, pMem->enc);

  84133.   if( rc<=0 ){

  84134.     if( rc==0 && sqlite3Atoi64(pMem->z, &ix, pMem->n, pMem->enc)<=1 ){

  84135.       pMem->u.i = ix;

  84136.       return MEM_Int;

  84137.     }else{

  84138.       return MEM_Real;

  84139.     }

  84140.   }else if( rc==1 && sqlite3Atoi64(pMem->z, &ix, pMem->n, pMem->enc)==0 ){

  84141.     pMem->u.i = ix;

  84142.     return MEM_Int;

  84143.   }

  84144.   return MEM_Real;

  84145. }

  84146. 

  84147. /*

  84148. ** Return the numeric type for pMem, either MEM_Int or MEM_Real or both or

  84149. ** none.  

  84150. **

  84151. ** Unlike applyNumericAffinity(), this routine does not modify pMem->flags.

  84152. ** But it does set pMem->u.r and pMem->u.i appropriately.

  84153. */

  84154. static u16 numericType(Mem *pMem){

  84155.   if( pMem->flags & (MEM_Int|MEM_Real|MEM_IntReal) ){

  84156.     testcase( pMem->flags & MEM_Int );

  84157.     testcase( pMem->flags & MEM_Real );

  84158.     testcase( pMem->flags & MEM_IntReal );

  84159.     return pMem->flags & (MEM_Int|MEM_Real|MEM_IntReal);

  84160.   }

  84161.   if( pMem->flags & (MEM_Str|MEM_Blob) ){

  84162.     testcase( pMem->flags & MEM_Str );

  84163.     testcase( pMem->flags & MEM_Blob );

  84164.     return computeNumericType(pMem);

  84165.   }

  84166.   return 0;

  84167. }

  84168. 

  84169. #ifdef SQLITE_DEBUG

  84170. /*

  84171. ** Write a nice string representation of the contents of cell pMem

  84172. ** into buffer zBuf, length nBuf.

  84173. */

  84174. SQLITE_PRIVATE void sqlite3VdbeMemPrettyPrint(Mem *pMem, char *zBuf){

  84175.   char *zCsr = zBuf;

  84176.   int f = pMem->flags;

  84177. 

  84178.   static const char *const encnames[] = {"(X)", "(8)", "(16LE)", "(16BE)"};

  84179. 

  84180.   if( f&MEM_Blob ){

  84181.     int i;

  84182.     char c;

  84183.     if( f & MEM_Dyn ){

  84184.       c = 'z';

  84185.       assert( (f & (MEM_Static|MEM_Ephem))==0 );

  84186.     }else if( f & MEM_Static ){

  84187.       c = 't';

  84188.       assert( (f & (MEM_Dyn|MEM_Ephem))==0 );

  84189.     }else if( f & MEM_Ephem ){

  84190.       c = 'e';

  84191.       assert( (f & (MEM_Static|MEM_Dyn))==0 );

  84192.     }else{

  84193.       c = 's';

  84194.     }

  84195.     *(zCsr++) = c;

  84196.     sqlite3_snprintf(100, zCsr, "%d[", pMem->n);

  84197.     zCsr += sqlite3Strlen30(zCsr);

  84198.     for(i=0; i<16 && i<pMem->n; i++){

  84199.       sqlite3_snprintf(100, zCsr, "%02X", ((int)pMem->z[i] & 0xFF));

  84200.       zCsr += sqlite3Strlen30(zCsr);

  84201.     }

  84202.     for(i=0; i<16 && i<pMem->n; i++){

  84203.       char z = pMem->z[i];

  84204.       if( z<32 || z>126 ) *zCsr++ = '.';

  84205.       else *zCsr++ = z;

  84206.     }

  84207.     *(zCsr++) = ']';

  84208.     if( f & MEM_Zero ){

  84209.       sqlite3_snprintf(100, zCsr,"+%dz",pMem->u.nZero);

  84210.       zCsr += sqlite3Strlen30(zCsr);

  84211.     }

  84212.     *zCsr = '\0';

  84213.   }else if( f & MEM_Str ){

  84214.     int j, k;

  84215.     zBuf[0] = ' ';

  84216.     if( f & MEM_Dyn ){

  84217.       zBuf[1] = 'z';

  84218.       assert( (f & (MEM_Static|MEM_Ephem))==0 );

  84219.     }else if( f & MEM_Static ){

  84220.       zBuf[1] = 't';

  84221.       assert( (f & (MEM_Dyn|MEM_Ephem))==0 );

  84222.     }else if( f & MEM_Ephem ){

  84223.       zBuf[1] = 'e';

  84224.       assert( (f & (MEM_Static|MEM_Dyn))==0 );

  84225.     }else{

  84226.       zBuf[1] = 's';

  84227.     }

  84228.     k = 2;

  84229.     sqlite3_snprintf(100, &zBuf[k], "%d", pMem->n);

  84230.     k += sqlite3Strlen30(&zBuf[k]);

  84231.     zBuf[k++] = '[';

  84232.     for(j=0; j<15 && j<pMem->n; j++){

  84233.       u8 c = pMem->z[j];

  84234.       if( c>=0x20 && c<0x7f ){

  84235.         zBuf[k++] = c;

  84236.       }else{

  84237.         zBuf[k++] = '.';

  84238.       }

  84239.     }

  84240.     zBuf[k++] = ']';

  84241.     sqlite3_snprintf(100,&zBuf[k], encnames[pMem->enc]);

  84242.     k += sqlite3Strlen30(&zBuf[k]);

  84243.     zBuf[k++] = 0;

  84244.   }

  84245. }

  84246. #endif

  84247. 

  84248. #ifdef SQLITE_DEBUG

  84249. /*

  84250. ** Print the value of a register for tracing purposes:

  84251. */

  84252. static void memTracePrint(Mem *p){

  84253.   if( p->flags & MEM_Undefined ){

  84254.     printf(" undefined");

  84255.   }else if( p->flags & MEM_Null ){

  84256.     printf(p->flags & MEM_Zero ? " NULL-nochng" : " NULL");

  84257.   }else if( (p->flags & (MEM_Int|MEM_Str))==(MEM_Int|MEM_Str) ){

  84258.     printf(" si:%lld", p->u.i);

  84259.   }else if( (p->flags & (MEM_IntReal))!=0 ){

  84260.     printf(" ir:%lld", p->u.i);

  84261.   }else if( p->flags & MEM_Int ){

  84262.     printf(" i:%lld", p->u.i);

  84263. #ifndef SQLITE_OMIT_FLOATING_POINT

  84264.   }else if( p->flags & MEM_Real ){

  84265.     printf(" r:%g", p->u.r);

  84266. #endif

  84267.   }else if( sqlite3VdbeMemIsRowSet(p) ){

  84268.     printf(" (rowset)");

  84269.   }else{

  84270.     char zBuf[200];

  84271.     sqlite3VdbeMemPrettyPrint(p, zBuf);

  84272.     printf(" %s", zBuf);

  84273.   }

  84274.   if( p->flags & MEM_Subtype ) printf(" subtype=0x%02x", p->eSubtype);

  84275. }

  84276. static void registerTrace(int iReg, Mem *p){

  84277.   printf("REG[%d] = ", iReg);

  84278.   memTracePrint(p);

  84279.   printf("\n");

  84280.   sqlite3VdbeCheckMemInvariants(p);

  84281. }

  84282. #endif

  84283. 

  84284. #ifdef SQLITE_DEBUG

  84285. #  define REGISTER_TRACE(R,M) if(db->flags&SQLITE_VdbeTrace)registerTrace(R,M)

  84286. #else

  84287. #  define REGISTER_TRACE(R,M)

  84288. #endif

  84289. 

  84290. 

  84291. #ifdef VDBE_PROFILE

  84292. 

  84293. /* 

  84294. ** hwtime.h contains inline assembler code for implementing 

  84295. ** high-performance timing routines.

  84296. */

  84297. /************** Include hwtime.h in the middle of vdbe.c *********************/

  84298. /************** Begin file hwtime.h ******************************************/

  84299. /*

  84300. ** 2008 May 27

  84301. **

  84302. ** The author disclaims copyright to this source code.  In place of

  84303. ** a legal notice, here is a blessing:

  84304. **

  84305. **    May you do good and not evil.

  84306. **    May you find forgiveness for yourself and forgive others.

  84307. **    May you share freely, never taking more than you give.

  84308. **

  84309. ******************************************************************************

  84310. **

  84311. ** This file contains inline asm code for retrieving "high-performance"

  84312. ** counters for x86 class CPUs.

  84313. */

  84314. #ifndef SQLITE_HWTIME_H

  84315. #define SQLITE_HWTIME_H

  84316. 

  84317. /*

  84318. ** The following routine only works on pentium-class (or newer) processors.

  84319. ** It uses the RDTSC opcode to read the cycle count value out of the

  84320. ** processor and returns that value.  This can be used for high-res

  84321. ** profiling.

  84322. */

  84323. #if (defined(__GNUC__) || defined(_MSC_VER)) && \

  84324.       (defined(i386) || defined(__i386__) || defined(_M_IX86))

  84325. 

  84326.   #if defined(__GNUC__)

  84327. 

  84328.   __inline__ sqlite_uint64 sqlite3Hwtime(void){

  84329.      unsigned int lo, hi;

  84330.      __asm__ __volatile__ ("rdtsc" : "=a" (lo), "=d" (hi));

  84331.      return (sqlite_uint64)hi << 32 | lo;

  84332.   }

  84333. 

  84334.   #elif defined(_MSC_VER)

  84335. 

  84336.   __declspec(naked) __inline sqlite_uint64 __cdecl sqlite3Hwtime(void){

  84337.      __asm {

  84338.         rdtsc

  84339.         ret       ; return value at EDX:EAX

  84340.      }

  84341.   }

  84342. 

  84343.   #endif

  84344. 

  84345. #elif (defined(__GNUC__) && defined(__x86_64__))

  84346. 

  84347.   __inline__ sqlite_uint64 sqlite3Hwtime(void){

  84348.       unsigned long val;

  84349.       __asm__ __volatile__ ("rdtsc" : "=A" (val));

  84350.       return val;

  84351.   }

  84352.  

  84353. #elif (defined(__GNUC__) && defined(__ppc__))

  84354. 

  84355.   __inline__ sqlite_uint64 sqlite3Hwtime(void){

  84356.       unsigned long long retval;

  84357.       unsigned long junk;

  84358.       __asm__ __volatile__ ("\n\

  84359.           1:      mftbu   %1\n\

  84360.                   mftb    %L0\n\

  84361.                   mftbu   %0\n\

  84362.                   cmpw    %0,%1\n\

  84363.                   bne     1b"

  84364.                   : "=r" (retval), "=r" (junk));

  84365.       return retval;

  84366.   }

  84367. 

  84368. #else

  84369. 

  84370.   #error Need implementation of sqlite3Hwtime() for your platform.

  84371. 

  84372.   /*

  84373.   ** To compile without implementing sqlite3Hwtime() for your platform,

  84374.   ** you can remove the above #error and use the following

  84375.   ** stub function.  You will lose timing support for many

  84376.   ** of the debugging and testing utilities, but it should at

  84377.   ** least compile and run.

  84378.   */

  84379. SQLITE_PRIVATE   sqlite_uint64 sqlite3Hwtime(void){ return ((sqlite_uint64)0); }

  84380. 

  84381. #endif

  84382. 

  84383. #endif /* !defined(SQLITE_HWTIME_H) */

  84384. 

  84385. /************** End of hwtime.h **********************************************/

  84386. /************** Continuing where we left off in vdbe.c ***********************/

  84387. 

  84388. #endif

  84389. 

  84390. #ifndef NDEBUG

  84391. /*

  84392. ** This function is only called from within an assert() expression. It

  84393. ** checks that the sqlite3.nTransaction variable is correctly set to

  84394. ** the number of non-transaction savepoints currently in the 

  84395. ** linked list starting at sqlite3.pSavepoint.

  84396. ** 

  84397. ** Usage:

  84398. **

  84399. **     assert( checkSavepointCount(db) );

  84400. */

  84401. static int checkSavepointCount(sqlite3 *db){

  84402.   int n = 0;

  84403.   Savepoint *p;

  84404.   for(p=db->pSavepoint; p; p=p->pNext) n++;

  84405.   assert( n==(db->nSavepoint + db->isTransactionSavepoint) );

  84406.   return 1;

  84407. }

  84408. #endif

  84409. 

  84410. /*

  84411. ** Return the register of pOp->p2 after first preparing it to be

  84412. ** overwritten with an integer value.

  84413. */

  84414. static SQLITE_NOINLINE Mem *out2PrereleaseWithClear(Mem *pOut){

  84415.   sqlite3VdbeMemSetNull(pOut);

  84416.   pOut->flags = MEM_Int;

  84417.   return pOut;

  84418. }

  84419. static Mem *out2Prerelease(Vdbe *p, VdbeOp *pOp){

  84420.   Mem *pOut;

  84421.   assert( pOp->p2>0 );

  84422.   assert( pOp->p2<=(p->nMem+1 - p->nCursor) );

  84423.   pOut = &p->aMem[pOp->p2];

  84424.   memAboutToChange(p, pOut);

  84425.   if( VdbeMemDynamic(pOut) ){ /*OPTIMIZATION-IF-FALSE*/

  84426.     return out2PrereleaseWithClear(pOut);

  84427.   }else{

  84428.     pOut->flags = MEM_Int;

  84429.     return pOut;

  84430.   }

  84431. }

  84432. 

  84433. 

  84434. /*

  84435. ** Execute as much of a VDBE program as we can.

  84436. ** This is the core of sqlite3_step().  

  84437. */

  84438. SQLITE_PRIVATE int sqlite3VdbeExec(

  84439.   Vdbe *p                    /* The VDBE */

  84440. ){

  84441.   Op *aOp = p->aOp;          /* Copy of p->aOp */

  84442.   Op *pOp = aOp;             /* Current operation */

  84443. #if defined(SQLITE_DEBUG) || defined(VDBE_PROFILE)

  84444.   Op *pOrigOp;               /* Value of pOp at the top of the loop */

  84445. #endif

  84446. #ifdef SQLITE_DEBUG

  84447.   int nExtraDelete = 0;      /* Verifies FORDELETE and AUXDELETE flags */

  84448. #endif

  84449.   int rc = SQLITE_OK;        /* Value to return */

  84450.   sqlite3 *db = p->db;       /* The database */

  84451.   u8 resetSchemaOnFault = 0; /* Reset schema after an error if positive */

  84452.   u8 encoding = ENC(db);     /* The database encoding */

  84453.   int iCompare = 0;          /* Result of last comparison */

  84454.   unsigned nVmStep = 0;      /* Number of virtual machine steps */

  84455. #ifndef SQLITE_OMIT_PROGRESS_CALLBACK

  84456.   unsigned nProgressLimit;   /* Invoke xProgress() when nVmStep reaches this */

  84457. #endif

  84458.   Mem *aMem = p->aMem;       /* Copy of p->aMem */

  84459.   Mem *pIn1 = 0;             /* 1st input operand */

  84460.   Mem *pIn2 = 0;             /* 2nd input operand */

  84461.   Mem *pIn3 = 0;             /* 3rd input operand */

  84462.   Mem *pOut = 0;             /* Output operand */

  84463. #ifdef VDBE_PROFILE

  84464.   u64 start;                 /* CPU clock count at start of opcode */

  84465. #endif

  84466.   /*** INSERT STACK UNION HERE ***/

  84467. 

  84468.   assert( p->magic==VDBE_MAGIC_RUN );  /* sqlite3_step() verifies this */

  84469.   sqlite3VdbeEnter(p);

  84470. #ifndef SQLITE_OMIT_PROGRESS_CALLBACK

  84471.   if( db->xProgress ){

  84472.     u32 iPrior = p->aCounter[SQLITE_STMTSTATUS_VM_STEP];

  84473.     assert( 0 < db->nProgressOps );

  84474.     nProgressLimit = db->nProgressOps - (iPrior % db->nProgressOps);

  84475.   }else{

  84476.     nProgressLimit = 0xffffffff;

  84477.   }

  84478. #endif

  84479.   if( p->rc==SQLITE_NOMEM ){

  84480.     /* This happens if a malloc() inside a call to sqlite3_column_text() or

  84481.     ** sqlite3_column_text16() failed.  */

  84482.     goto no_mem;

  84483.   }

  84484.   assert( p->rc==SQLITE_OK || (p->rc&0xff)==SQLITE_BUSY );

  84485.   assert( p->bIsReader || p->readOnly!=0 );

  84486.   p->iCurrentTime = 0;

  84487.   assert( p->explain==0 );

  84488.   p->pResultSet = 0;

  84489.   db->busyHandler.nBusy = 0;

  84490.   if( db->u1.isInterrupted ) goto abort_due_to_interrupt;

  84491.   sqlite3VdbeIOTraceSql(p);

  84492. #ifdef SQLITE_DEBUG

  84493.   sqlite3BeginBenignMalloc();

  84494.   if( p->pc==0

  84495.    && (p->db->flags & (SQLITE_VdbeListing|SQLITE_VdbeEQP|SQLITE_VdbeTrace))!=0

  84496.   ){

  84497.     int i;

  84498.     int once = 1;

  84499.     sqlite3VdbePrintSql(p);

  84500.     if( p->db->flags & SQLITE_VdbeListing ){

  84501.       printf("VDBE Program Listing:\n");

  84502.       for(i=0; i<p->nOp; i++){

  84503.         sqlite3VdbePrintOp(stdout, i, &aOp[i]);

  84504.       }

  84505.     }

  84506.     if( p->db->flags & SQLITE_VdbeEQP ){

  84507.       for(i=0; i<p->nOp; i++){

  84508.         if( aOp[i].opcode==OP_Explain ){

  84509.           if( once ) printf("VDBE Query Plan:\n");

  84510.           printf("%s\n", aOp[i].p4.z);

  84511.           once = 0;

  84512.         }

  84513.       }

  84514.     }

  84515.     if( p->db->flags & SQLITE_VdbeTrace )  printf("VDBE Trace:\n");

  84516.   }

  84517.   sqlite3EndBenignMalloc();

  84518. #endif

  84519.   for(pOp=&aOp[p->pc]; 1; pOp++){

  84520.     /* Errors are detected by individual opcodes, with an immediate

  84521.     ** jumps to abort_due_to_error. */

  84522.     assert( rc==SQLITE_OK );

  84523. 

  84524.     assert( pOp>=aOp && pOp<&aOp[p->nOp]);

  84525. #ifdef VDBE_PROFILE

  84526.     start = sqlite3NProfileCnt ? sqlite3NProfileCnt : sqlite3Hwtime();

  84527. #endif

  84528.     nVmStep++;

  84529. #ifdef SQLITE_ENABLE_STMT_SCANSTATUS

  84530.     if( p->anExec ) p->anExec[(int)(pOp-aOp)]++;

  84531. #endif

  84532. 

  84533.     /* Only allow tracing if SQLITE_DEBUG is defined.

  84534.     */

  84535. #ifdef SQLITE_DEBUG

  84536.     if( db->flags & SQLITE_VdbeTrace ){

  84537.       sqlite3VdbePrintOp(stdout, (int)(pOp - aOp), pOp);

  84538.     }

  84539. #endif

  84540.       

  84541. 

  84542.     /* Check to see if we need to simulate an interrupt.  This only happens

  84543.     ** if we have a special test build.

  84544.     */

  84545. #ifdef SQLITE_TEST

  84546.     if( sqlite3_interrupt_count>0 ){

  84547.       sqlite3_interrupt_count--;

  84548.       if( sqlite3_interrupt_count==0 ){

  84549.         sqlite3_interrupt(db);

  84550.       }

  84551.     }

  84552. #endif

  84553. 

  84554.     /* Sanity checking on other operands */

  84555. #ifdef SQLITE_DEBUG

  84556.     {

  84557.       u8 opProperty = sqlite3OpcodeProperty[pOp->opcode];

  84558.       if( (opProperty & OPFLG_IN1)!=0 ){

  84559.         assert( pOp->p1>0 );

  84560.         assert( pOp->p1<=(p->nMem+1 - p->nCursor) );

  84561.         assert( memIsValid(&aMem[pOp->p1]) );

  84562.         assert( sqlite3VdbeCheckMemInvariants(&aMem[pOp->p1]) );

  84563.         REGISTER_TRACE(pOp->p1, &aMem[pOp->p1]);

  84564.       }

  84565.       if( (opProperty & OPFLG_IN2)!=0 ){

  84566.         assert( pOp->p2>0 );

  84567.         assert( pOp->p2<=(p->nMem+1 - p->nCursor) );

  84568.         assert( memIsValid(&aMem[pOp->p2]) );

  84569.         assert( sqlite3VdbeCheckMemInvariants(&aMem[pOp->p2]) );

  84570.         REGISTER_TRACE(pOp->p2, &aMem[pOp->p2]);

  84571.       }

  84572.       if( (opProperty & OPFLG_IN3)!=0 ){

  84573.         assert( pOp->p3>0 );

  84574.         assert( pOp->p3<=(p->nMem+1 - p->nCursor) );

  84575.         assert( memIsValid(&aMem[pOp->p3]) );

  84576.         assert( sqlite3VdbeCheckMemInvariants(&aMem[pOp->p3]) );

  84577.         REGISTER_TRACE(pOp->p3, &aMem[pOp->p3]);

  84578.       }

  84579.       if( (opProperty & OPFLG_OUT2)!=0 ){

  84580.         assert( pOp->p2>0 );

  84581.         assert( pOp->p2<=(p->nMem+1 - p->nCursor) );

  84582.         memAboutToChange(p, &aMem[pOp->p2]);

  84583.       }

  84584.       if( (opProperty & OPFLG_OUT3)!=0 ){

  84585.         assert( pOp->p3>0 );

  84586.         assert( pOp->p3<=(p->nMem+1 - p->nCursor) );

  84587.         memAboutToChange(p, &aMem[pOp->p3]);

  84588.       }

  84589.     }

  84590. #endif

  84591. #if defined(SQLITE_DEBUG) || defined(VDBE_PROFILE)

  84592.     pOrigOp = pOp;

  84593. #endif

  84594.   

  84595.     switch( pOp->opcode ){

  84596. 

  84597. /*****************************************************************************

  84598. ** What follows is a massive switch statement where each case implements a

  84599. ** separate instruction in the virtual machine.  If we follow the usual

  84600. ** indentation conventions, each case should be indented by 6 spaces.  But

  84601. ** that is a lot of wasted space on the left margin.  So the code within

  84602. ** the switch statement will break with convention and be flush-left. Another

  84603. ** big comment (similar to this one) will mark the point in the code where

  84604. ** we transition back to normal indentation.

  84605. **

  84606. ** The formatting of each case is important.  The makefile for SQLite

  84607. ** generates two C files "opcodes.h" and "opcodes.c" by scanning this

  84608. ** file looking for lines that begin with "case OP_".  The opcodes.h files

  84609. ** will be filled with #defines that give unique integer values to each

  84610. ** opcode and the opcodes.c file is filled with an array of strings where

  84611. ** each string is the symbolic name for the corresponding opcode.  If the

  84612. ** case statement is followed by a comment of the form "/# same as ... #/"

  84613. ** that comment is used to determine the particular value of the opcode.

  84614. **

  84615. ** Other keywords in the comment that follows each case are used to

  84616. ** construct the OPFLG_INITIALIZER value that initializes opcodeProperty[].

  84617. ** Keywords include: in1, in2, in3, out2, out3.  See

  84618. ** the mkopcodeh.awk script for additional information.

  84619. **

  84620. ** Documentation about VDBE opcodes is generated by scanning this file

  84621. ** for lines of that contain "Opcode:".  That line and all subsequent

  84622. ** comment lines are used in the generation of the opcode.html documentation

  84623. ** file.

  84624. **

  84625. ** SUMMARY:

  84626. **

  84627. **     Formatting is important to scripts that scan this file.

  84628. **     Do not deviate from the formatting style currently in use.

  84629. **

  84630. *****************************************************************************/

  84631. 

  84632. /* Opcode:  Goto * P2 * * *

  84633. **

  84634. ** An unconditional jump to address P2.

  84635. ** The next instruction executed will be 

  84636. ** the one at index P2 from the beginning of

  84637. ** the program.

  84638. **

  84639. ** The P1 parameter is not actually used by this opcode.  However, it

  84640. ** is sometimes set to 1 instead of 0 as a hint to the command-line shell

  84641. ** that this Goto is the bottom of a loop and that the lines from P2 down

  84642. ** to the current line should be indented for EXPLAIN output.

  84643. */

  84644. case OP_Goto: {             /* jump */

  84645. jump_to_p2_and_check_for_interrupt:

  84646.   pOp = &aOp[pOp->p2 - 1];

  84647. 

  84648.   /* Opcodes that are used as the bottom of a loop (OP_Next, OP_Prev,

  84649.   ** OP_VNext, or OP_SorterNext) all jump here upon

  84650.   ** completion.  Check to see if sqlite3_interrupt() has been called

  84651.   ** or if the progress callback needs to be invoked. 

  84652.   **

  84653.   ** This code uses unstructured "goto" statements and does not look clean.

  84654.   ** But that is not due to sloppy coding habits. The code is written this

  84655.   ** way for performance, to avoid having to run the interrupt and progress

  84656.   ** checks on every opcode.  This helps sqlite3_step() to run about 1.5%

  84657.   ** faster according to "valgrind --tool=cachegrind" */

  84658. check_for_interrupt:

  84659.   if( db->u1.isInterrupted ) goto abort_due_to_interrupt;

  84660. #ifndef SQLITE_OMIT_PROGRESS_CALLBACK

  84661.   /* Call the progress callback if it is configured and the required number

  84662.   ** of VDBE ops have been executed (either since this invocation of

  84663.   ** sqlite3VdbeExec() or since last time the progress callback was called).

  84664.   ** If the progress callback returns non-zero, exit the virtual machine with

  84665.   ** a return code SQLITE_ABORT.

  84666.   */

  84667.   while( nVmStep>=nProgressLimit && db->xProgress!=0 ){

  84668.     assert( db->nProgressOps!=0 );

  84669.     nProgressLimit += db->nProgressOps;

  84670.     if( db->xProgress(db->pProgressArg) ){

  84671.       nProgressLimit = 0xffffffff;

  84672.       rc = SQLITE_INTERRUPT;

  84673.       goto abort_due_to_error;

  84674.     }

  84675.   }

  84676. #endif

  84677.   

  84678.   break;

  84679. }

  84680. 

  84681. /* Opcode:  Gosub P1 P2 * * *

  84682. **

  84683. ** Write the current address onto register P1

  84684. ** and then jump to address P2.

  84685. */

  84686. case OP_Gosub: {            /* jump */

  84687.   assert( pOp->p1>0 && pOp->p1<=(p->nMem+1 - p->nCursor) );

  84688.   pIn1 = &aMem[pOp->p1];

  84689.   assert( VdbeMemDynamic(pIn1)==0 );

  84690.   memAboutToChange(p, pIn1);

  84691.   pIn1->flags = MEM_Int;

  84692.   pIn1->u.i = (int)(pOp-aOp);

  84693.   REGISTER_TRACE(pOp->p1, pIn1);

  84694. 

  84695.   /* Most jump operations do a goto to this spot in order to update

  84696.   ** the pOp pointer. */

  84697. jump_to_p2:

  84698.   pOp = &aOp[pOp->p2 - 1];

  84699.   break;

  84700. }

  84701. 

  84702. /* Opcode:  Return P1 * * * *

  84703. **

  84704. ** Jump to the next instruction after the address in register P1.  After

  84705. ** the jump, register P1 becomes undefined.

  84706. */

  84707. case OP_Return: {           /* in1 */

  84708.   pIn1 = &aMem[pOp->p1];

  84709.   assert( pIn1->flags==MEM_Int );

  84710.   pOp = &aOp[pIn1->u.i];

  84711.   pIn1->flags = MEM_Undefined;

  84712.   break;

  84713. }

  84714. 

  84715. /* Opcode: InitCoroutine P1 P2 P3 * *

  84716. **

  84717. ** Set up register P1 so that it will Yield to the coroutine

  84718. ** located at address P3.

  84719. **

  84720. ** If P2!=0 then the coroutine implementation immediately follows

  84721. ** this opcode.  So jump over the coroutine implementation to

  84722. ** address P2.

  84723. **

  84724. ** See also: EndCoroutine

  84725. */

  84726. case OP_InitCoroutine: {     /* jump */

  84727.   assert( pOp->p1>0 &&  pOp->p1<=(p->nMem+1 - p->nCursor) );

  84728.   assert( pOp->p2>=0 && pOp->p2<p->nOp );

  84729.   assert( pOp->p3>=0 && pOp->p3<p->nOp );

  84730.   pOut = &aMem[pOp->p1];

  84731.   assert( !VdbeMemDynamic(pOut) );

  84732.   pOut->u.i = pOp->p3 - 1;

  84733.   pOut->flags = MEM_Int;

  84734.   if( pOp->p2 ) goto jump_to_p2;

  84735.   break;

  84736. }

  84737. 

  84738. /* Opcode:  EndCoroutine P1 * * * *

  84739. **

  84740. ** The instruction at the address in register P1 is a Yield.

  84741. ** Jump to the P2 parameter of that Yield.

  84742. ** After the jump, register P1 becomes undefined.

  84743. **

  84744. ** See also: InitCoroutine

  84745. */

  84746. case OP_EndCoroutine: {           /* in1 */

  84747.   VdbeOp *pCaller;

  84748.   pIn1 = &aMem[pOp->p1];

  84749.   assert( pIn1->flags==MEM_Int );

  84750.   assert( pIn1->u.i>=0 && pIn1->u.i<p->nOp );

  84751.   pCaller = &aOp[pIn1->u.i];

  84752.   assert( pCaller->opcode==OP_Yield );

  84753.   assert( pCaller->p2>=0 && pCaller->p2<p->nOp );

  84754.   pOp = &aOp[pCaller->p2 - 1];

  84755.   pIn1->flags = MEM_Undefined;

  84756.   break;

  84757. }

  84758. 

  84759. /* Opcode:  Yield P1 P2 * * *

  84760. **

  84761. ** Swap the program counter with the value in register P1.  This

  84762. ** has the effect of yielding to a coroutine.

  84763. **

  84764. ** If the coroutine that is launched by this instruction ends with

  84765. ** Yield or Return then continue to the next instruction.  But if

  84766. ** the coroutine launched by this instruction ends with

  84767. ** EndCoroutine, then jump to P2 rather than continuing with the

  84768. ** next instruction.

  84769. **

  84770. ** See also: InitCoroutine

  84771. */

  84772. case OP_Yield: {            /* in1, jump */

  84773.   int pcDest;

  84774.   pIn1 = &aMem[pOp->p1];

  84775.   assert( VdbeMemDynamic(pIn1)==0 );

  84776.   pIn1->flags = MEM_Int;

  84777.   pcDest = (int)pIn1->u.i;

  84778.   pIn1->u.i = (int)(pOp - aOp);

  84779.   REGISTER_TRACE(pOp->p1, pIn1);

  84780.   pOp = &aOp[pcDest];

  84781.   break;

  84782. }

  84783. 

  84784. /* Opcode:  HaltIfNull  P1 P2 P3 P4 P5

  84785. ** Synopsis: if r[P3]=null halt

  84786. **

  84787. ** Check the value in register P3.  If it is NULL then Halt using

  84788. ** parameter P1, P2, and P4 as if this were a Halt instruction.  If the

  84789. ** value in register P3 is not NULL, then this routine is a no-op.

  84790. ** The P5 parameter should be 1.

  84791. */

  84792. case OP_HaltIfNull: {      /* in3 */

  84793.   pIn3 = &aMem[pOp->p3];

  84794. #ifdef SQLITE_DEBUG

  84795.   if( pOp->p2==OE_Abort ){ sqlite3VdbeAssertAbortable(p); }

  84796. #endif

  84797.   if( (pIn3->flags & MEM_Null)==0 ) break;

  84798.   /* Fall through into OP_Halt */

  84799. }

  84800. 

  84801. /* Opcode:  Halt P1 P2 * P4 P5

  84802. **

  84803. ** Exit immediately.  All open cursors, etc are closed

  84804. ** automatically.

  84805. **

  84806. ** P1 is the result code returned by sqlite3_exec(), sqlite3_reset(),

  84807. ** or sqlite3_finalize().  For a normal halt, this should be SQLITE_OK (0).

  84808. ** For errors, it can be some other value.  If P1!=0 then P2 will determine

  84809. ** whether or not to rollback the current transaction.  Do not rollback

  84810. ** if P2==OE_Fail. Do the rollback if P2==OE_Rollback.  If P2==OE_Abort,

  84811. ** then back out all changes that have occurred during this execution of the

  84812. ** VDBE, but do not rollback the transaction. 

  84813. **

  84814. ** If P4 is not null then it is an error message string.

  84815. **

  84816. ** P5 is a value between 0 and 4, inclusive, that modifies the P4 string.

  84817. **

  84818. **    0:  (no change)

  84819. **    1:  NOT NULL contraint failed: P4

  84820. **    2:  UNIQUE constraint failed: P4

  84821. **    3:  CHECK constraint failed: P4

  84822. **    4:  FOREIGN KEY constraint failed: P4

  84823. **

  84824. ** If P5 is not zero and P4 is NULL, then everything after the ":" is

  84825. ** omitted.

  84826. **

  84827. ** There is an implied "Halt 0 0 0" instruction inserted at the very end of

  84828. ** every program.  So a jump past the last instruction of the program

  84829. ** is the same as executing Halt.

  84830. */

  84831. case OP_Halt: {

  84832.   VdbeFrame *pFrame;

  84833.   int pcx;

  84834. 

  84835.   pcx = (int)(pOp - aOp);

  84836. #ifdef SQLITE_DEBUG

  84837.   if( pOp->p2==OE_Abort ){ sqlite3VdbeAssertAbortable(p); }

  84838. #endif

  84839.   if( pOp->p1==SQLITE_OK && p->pFrame ){

  84840.     /* Halt the sub-program. Return control to the parent frame. */

  84841.     pFrame = p->pFrame;

  84842.     p->pFrame = pFrame->pParent;

  84843.     p->nFrame--;

  84844.     sqlite3VdbeSetChanges(db, p->nChange);

  84845.     pcx = sqlite3VdbeFrameRestore(pFrame);

  84846.     if( pOp->p2==OE_Ignore ){

  84847.       /* Instruction pcx is the OP_Program that invoked the sub-program 

  84848.       ** currently being halted. If the p2 instruction of this OP_Halt

  84849.       ** instruction is set to OE_Ignore, then the sub-program is throwing

  84850.       ** an IGNORE exception. In this case jump to the address specified

  84851.       ** as the p2 of the calling OP_Program.  */

  84852.       pcx = p->aOp[pcx].p2-1;

  84853.     }

  84854.     aOp = p->aOp;

  84855.     aMem = p->aMem;

  84856.     pOp = &aOp[pcx];

  84857.     break;

  84858.   }

  84859.   p->rc = pOp->p1;

  84860.   p->errorAction = (u8)pOp->p2;

  84861.   p->pc = pcx;

  84862.   assert( pOp->p5<=4 );

  84863.   if( p->rc ){

  84864.     if( pOp->p5 ){

  84865.       static const char * const azType[] = { "NOT NULL", "UNIQUE", "CHECK",

  84866.                                              "FOREIGN KEY" };

  84867.       testcase( pOp->p5==1 );

  84868.       testcase( pOp->p5==2 );

  84869.       testcase( pOp->p5==3 );

  84870.       testcase( pOp->p5==4 );

  84871.       sqlite3VdbeError(p, "%s constraint failed", azType[pOp->p5-1]);

  84872.       if( pOp->p4.z ){

  84873.         p->zErrMsg = sqlite3MPrintf(db, "%z: %s", p->zErrMsg, pOp->p4.z);

  84874.       }

  84875.     }else{

  84876.       sqlite3VdbeError(p, "%s", pOp->p4.z);

  84877.     }

  84878.     sqlite3_log(pOp->p1, "abort at %d in [%s]: %s", pcx, p->zSql, p->zErrMsg);

  84879.   }

  84880.   rc = sqlite3VdbeHalt(p);

  84881.   assert( rc==SQLITE_BUSY || rc==SQLITE_OK || rc==SQLITE_ERROR );

  84882.   if( rc==SQLITE_BUSY ){

  84883.     p->rc = SQLITE_BUSY;

  84884.   }else{

  84885.     assert( rc==SQLITE_OK || (p->rc&0xff)==SQLITE_CONSTRAINT );

  84886.     assert( rc==SQLITE_OK || db->nDeferredCons>0 || db->nDeferredImmCons>0 );

  84887.     rc = p->rc ? SQLITE_ERROR : SQLITE_DONE;

  84888.   }

  84889.   goto vdbe_return;

  84890. }

  84891. 

  84892. /* Opcode: Integer P1 P2 * * *

  84893. ** Synopsis: r[P2]=P1

  84894. **

  84895. ** The 32-bit integer value P1 is written into register P2.

  84896. */

  84897. case OP_Integer: {         /* out2 */

  84898.   pOut = out2Prerelease(p, pOp);

  84899.   pOut->u.i = pOp->p1;

  84900.   break;

  84901. }

  84902. 

  84903. /* Opcode: Int64 * P2 * P4 *

  84904. ** Synopsis: r[P2]=P4

  84905. **

  84906. ** P4 is a pointer to a 64-bit integer value.

  84907. ** Write that value into register P2.

  84908. */

  84909. case OP_Int64: {           /* out2 */

  84910.   pOut = out2Prerelease(p, pOp);

  84911.   assert( pOp->p4.pI64!=0 );

  84912.   pOut->u.i = *pOp->p4.pI64;

  84913.   break;

  84914. }

  84915. 

  84916. #ifndef SQLITE_OMIT_FLOATING_POINT

  84917. /* Opcode: Real * P2 * P4 *

  84918. ** Synopsis: r[P2]=P4

  84919. **

  84920. ** P4 is a pointer to a 64-bit floating point value.

  84921. ** Write that value into register P2.

  84922. */

  84923. case OP_Real: {            /* same as TK_FLOAT, out2 */

  84924.   pOut = out2Prerelease(p, pOp);

  84925.   pOut->flags = MEM_Real;

  84926.   assert( !sqlite3IsNaN(*pOp->p4.pReal) );

  84927.   pOut->u.r = *pOp->p4.pReal;

  84928.   break;

  84929. }

  84930. #endif

  84931. 

  84932. /* Opcode: String8 * P2 * P4 *

  84933. ** Synopsis: r[P2]='P4'

  84934. **

  84935. ** P4 points to a nul terminated UTF-8 string. This opcode is transformed 

  84936. ** into a String opcode before it is executed for the first time.  During

  84937. ** this transformation, the length of string P4 is computed and stored

  84938. ** as the P1 parameter.

  84939. */

  84940. case OP_String8: {         /* same as TK_STRING, out2 */

  84941.   assert( pOp->p4.z!=0 );

  84942.   pOut = out2Prerelease(p, pOp);

  84943.   pOp->opcode = OP_String;

  84944.   pOp->p1 = sqlite3Strlen30(pOp->p4.z);

  84945. 

  84946. #ifndef SQLITE_OMIT_UTF16

  84947.   if( encoding!=SQLITE_UTF8 ){

  84948.     rc = sqlite3VdbeMemSetStr(pOut, pOp->p4.z, -1, SQLITE_UTF8, SQLITE_STATIC);

  84949.     assert( rc==SQLITE_OK || rc==SQLITE_TOOBIG );

  84950.     if( rc ) goto too_big;

  84951.     if( SQLITE_OK!=sqlite3VdbeChangeEncoding(pOut, encoding) ) goto no_mem;

  84952.     assert( pOut->szMalloc>0 && pOut->zMalloc==pOut->z );

  84953.     assert( VdbeMemDynamic(pOut)==0 );

  84954.     pOut->szMalloc = 0;

  84955.     pOut->flags |= MEM_Static;

  84956.     if( pOp->p4type==P4_DYNAMIC ){

  84957.       sqlite3DbFree(db, pOp->p4.z);

  84958.     }

  84959.     pOp->p4type = P4_DYNAMIC;

  84960.     pOp->p4.z = pOut->z;

  84961.     pOp->p1 = pOut->n;

  84962.   }

  84963. #endif

  84964.   if( pOp->p1>db->aLimit[SQLITE_LIMIT_LENGTH] ){

  84965.     goto too_big;

  84966.   }

  84967.   assert( rc==SQLITE_OK );

  84968.   /* Fall through to the next case, OP_String */

  84969. }

  84970.   

  84971. /* Opcode: String P1 P2 P3 P4 P5

  84972. ** Synopsis: r[P2]='P4' (len=P1)

  84973. **

  84974. ** The string value P4 of length P1 (bytes) is stored in register P2.

  84975. **

  84976. ** If P3 is not zero and the content of register P3 is equal to P5, then

  84977. ** the datatype of the register P2 is converted to BLOB.  The content is

  84978. ** the same sequence of bytes, it is merely interpreted as a BLOB instead

  84979. ** of a string, as if it had been CAST.  In other words:

  84980. **

  84981. ** if( P3!=0 and reg[P3]==P5 ) reg[P2] := CAST(reg[P2] as BLOB)

  84982. */

  84983. case OP_String: {          /* out2 */

  84984.   assert( pOp->p4.z!=0 );

  84985.   pOut = out2Prerelease(p, pOp);

  84986.   pOut->flags = MEM_Str|MEM_Static|MEM_Term;

  84987.   pOut->z = pOp->p4.z;

  84988.   pOut->n = pOp->p1;

  84989.   pOut->enc = encoding;

  84990.   UPDATE_MAX_BLOBSIZE(pOut);

  84991. #ifndef SQLITE_LIKE_DOESNT_MATCH_BLOBS

  84992.   if( pOp->p3>0 ){

  84993.     assert( pOp->p3<=(p->nMem+1 - p->nCursor) );

  84994.     pIn3 = &aMem[pOp->p3];

  84995.     assert( pIn3->flags & MEM_Int );

  84996.     if( pIn3->u.i==pOp->p5 ) pOut->flags = MEM_Blob|MEM_Static|MEM_Term;

  84997.   }

  84998. #endif

  84999.   break;

  85000. }

  85001. 

  85002. /* Opcode: Null P1 P2 P3 * *

  85003. ** Synopsis: r[P2..P3]=NULL

  85004. **

  85005. ** Write a NULL into registers P2.  If P3 greater than P2, then also write

  85006. ** NULL into register P3 and every register in between P2 and P3.  If P3

  85007. ** is less than P2 (typically P3 is zero) then only register P2 is

  85008. ** set to NULL.

  85009. **

  85010. ** If the P1 value is non-zero, then also set the MEM_Cleared flag so that

  85011. ** NULL values will not compare equal even if SQLITE_NULLEQ is set on

  85012. ** OP_Ne or OP_Eq.

  85013. */

  85014. case OP_Null: {           /* out2 */

  85015.   int cnt;

  85016.   u16 nullFlag;

  85017.   pOut = out2Prerelease(p, pOp);

  85018.   cnt = pOp->p3-pOp->p2;

  85019.   assert( pOp->p3<=(p->nMem+1 - p->nCursor) );

  85020.   pOut->flags = nullFlag = pOp->p1 ? (MEM_Null|MEM_Cleared) : MEM_Null;

  85021.   pOut->n = 0;

  85022. #ifdef SQLITE_DEBUG

  85023.   pOut->uTemp = 0;

  85024. #endif

  85025.   while( cnt>0 ){

  85026.     pOut++;

  85027.     memAboutToChange(p, pOut);

  85028.     sqlite3VdbeMemSetNull(pOut);

  85029.     pOut->flags = nullFlag;

  85030.     pOut->n = 0;

  85031.     cnt--;

  85032.   }

  85033.   break;

  85034. }

  85035. 

  85036. /* Opcode: SoftNull P1 * * * *

  85037. ** Synopsis: r[P1]=NULL

  85038. **

  85039. ** Set register P1 to have the value NULL as seen by the OP_MakeRecord

  85040. ** instruction, but do not free any string or blob memory associated with

  85041. ** the register, so that if the value was a string or blob that was

  85042. ** previously copied using OP_SCopy, the copies will continue to be valid.

  85043. */

  85044. case OP_SoftNull: {

  85045.   assert( pOp->p1>0 && pOp->p1<=(p->nMem+1 - p->nCursor) );

  85046.   pOut = &aMem[pOp->p1];

  85047.   pOut->flags = (pOut->flags&~(MEM_Undefined|MEM_AffMask))|MEM_Null;

  85048.   break;

  85049. }

  85050. 

  85051. /* Opcode: Blob P1 P2 * P4 *

  85052. ** Synopsis: r[P2]=P4 (len=P1)

  85053. **

  85054. ** P4 points to a blob of data P1 bytes long.  Store this

  85055. ** blob in register P2.

  85056. */

  85057. case OP_Blob: {                /* out2 */

  85058.   assert( pOp->p1 <= SQLITE_MAX_LENGTH );

  85059.   pOut = out2Prerelease(p, pOp);

  85060.   sqlite3VdbeMemSetStr(pOut, pOp->p4.z, pOp->p1, 0, 0);

  85061.   pOut->enc = encoding;

  85062.   UPDATE_MAX_BLOBSIZE(pOut);

  85063.   break;

  85064. }

  85065. 

  85066. /* Opcode: Variable P1 P2 * P4 *

  85067. ** Synopsis: r[P2]=parameter(P1,P4)

  85068. **

  85069. ** Transfer the values of bound parameter P1 into register P2

  85070. **

  85071. ** If the parameter is named, then its name appears in P4.

  85072. ** The P4 value is used by sqlite3_bind_parameter_name().

  85073. */

  85074. case OP_Variable: {            /* out2 */

  85075.   Mem *pVar;       /* Value being transferred */

  85076. 

  85077.   assert( pOp->p1>0 && pOp->p1<=p->nVar );

  85078.   assert( pOp->p4.z==0 || pOp->p4.z==sqlite3VListNumToName(p->pVList,pOp->p1) );

  85079.   pVar = &p->aVar[pOp->p1 - 1];

  85080.   if( sqlite3VdbeMemTooBig(pVar) ){

  85081.     goto too_big;

  85082.   }

  85083.   pOut = &aMem[pOp->p2];

  85084.   if( VdbeMemDynamic(pOut) ) sqlite3VdbeMemSetNull(pOut);

  85085.   memcpy(pOut, pVar, MEMCELLSIZE);

  85086.   pOut->flags &= ~(MEM_Dyn|MEM_Ephem);

  85087.   pOut->flags |= MEM_Static|MEM_FromBind;

  85088.   UPDATE_MAX_BLOBSIZE(pOut);

  85089.   break;

  85090. }

  85091. 

  85092. /* Opcode: Move P1 P2 P3 * *

  85093. ** Synopsis: r[P2@P3]=r[P1@P3]

  85094. **

  85095. ** Move the P3 values in register P1..P1+P3-1 over into

  85096. ** registers P2..P2+P3-1.  Registers P1..P1+P3-1 are

  85097. ** left holding a NULL.  It is an error for register ranges

  85098. ** P1..P1+P3-1 and P2..P2+P3-1 to overlap.  It is an error

  85099. ** for P3 to be less than 1.

  85100. */

  85101. case OP_Move: {

  85102.   int n;           /* Number of registers left to copy */

  85103.   int p1;          /* Register to copy from */

  85104.   int p2;          /* Register to copy to */

  85105. 

  85106.   n = pOp->p3;

  85107.   p1 = pOp->p1;

  85108.   p2 = pOp->p2;

  85109.   assert( n>0 && p1>0 && p2>0 );

  85110.   assert( p1+n<=p2 || p2+n<=p1 );

  85111. 

  85112.   pIn1 = &aMem[p1];

  85113.   pOut = &aMem[p2];

  85114.   do{

  85115.     assert( pOut<=&aMem[(p->nMem+1 - p->nCursor)] );

  85116.     assert( pIn1<=&aMem[(p->nMem+1 - p->nCursor)] );

  85117.     assert( memIsValid(pIn1) );

  85118.     memAboutToChange(p, pOut);

  85119.     sqlite3VdbeMemMove(pOut, pIn1);

  85120. #ifdef SQLITE_DEBUG

  85121.     if( pOut->pScopyFrom>=&aMem[p1] && pOut->pScopyFrom<pOut ){

  85122.       pOut->pScopyFrom += pOp->p2 - p1;

  85123.     }

  85124. #endif

  85125.     Deephemeralize(pOut);

  85126.     REGISTER_TRACE(p2++, pOut);

  85127.     pIn1++;

  85128.     pOut++;

  85129.   }while( --n );

  85130.   break;

  85131. }

  85132. 

  85133. /* Opcode: Copy P1 P2 P3 * *

  85134. ** Synopsis: r[P2@P3+1]=r[P1@P3+1]

  85135. **

  85136. ** Make a copy of registers P1..P1+P3 into registers P2..P2+P3.

  85137. **

  85138. ** This instruction makes a deep copy of the value.  A duplicate

  85139. ** is made of any string or blob constant.  See also OP_SCopy.

  85140. */

  85141. case OP_Copy: {

  85142.   int n;

  85143. 

  85144.   n = pOp->p3;

  85145.   pIn1 = &aMem[pOp->p1];

  85146.   pOut = &aMem[pOp->p2];

  85147.   assert( pOut!=pIn1 );

  85148.   while( 1 ){

  85149.     memAboutToChange(p, pOut);

  85150.     sqlite3VdbeMemShallowCopy(pOut, pIn1, MEM_Ephem);

  85151.     Deephemeralize(pOut);

  85152. #ifdef SQLITE_DEBUG

  85153.     pOut->pScopyFrom = 0;

  85154. #endif

  85155.     REGISTER_TRACE(pOp->p2+pOp->p3-n, pOut);

  85156.     if( (n--)==0 ) break;

  85157.     pOut++;

  85158.     pIn1++;

  85159.   }

  85160.   break;

  85161. }

  85162. 

  85163. /* Opcode: SCopy P1 P2 * * *

  85164. ** Synopsis: r[P2]=r[P1]

  85165. **

  85166. ** Make a shallow copy of register P1 into register P2.

  85167. **

  85168. ** This instruction makes a shallow copy of the value.  If the value

  85169. ** is a string or blob, then the copy is only a pointer to the

  85170. ** original and hence if the original changes so will the copy.

  85171. ** Worse, if the original is deallocated, the copy becomes invalid.

  85172. ** Thus the program must guarantee that the original will not change

  85173. ** during the lifetime of the copy.  Use OP_Copy to make a complete

  85174. ** copy.

  85175. */

  85176. case OP_SCopy: {            /* out2 */

  85177.   pIn1 = &aMem[pOp->p1];

  85178.   pOut = &aMem[pOp->p2];

  85179.   assert( pOut!=pIn1 );

  85180.   sqlite3VdbeMemShallowCopy(pOut, pIn1, MEM_Ephem);

  85181. #ifdef SQLITE_DEBUG

  85182.   pOut->pScopyFrom = pIn1;

  85183.   pOut->mScopyFlags = pIn1->flags;

  85184. #endif

  85185.   break;

  85186. }

  85187. 

  85188. /* Opcode: IntCopy P1 P2 * * *

  85189. ** Synopsis: r[P2]=r[P1]

  85190. **

  85191. ** Transfer the integer value held in register P1 into register P2.

  85192. **

  85193. ** This is an optimized version of SCopy that works only for integer

  85194. ** values.

  85195. */

  85196. case OP_IntCopy: {            /* out2 */

  85197.   pIn1 = &aMem[pOp->p1];

  85198.   assert( (pIn1->flags & MEM_Int)!=0 );

  85199.   pOut = &aMem[pOp->p2];

  85200.   sqlite3VdbeMemSetInt64(pOut, pIn1->u.i);

  85201.   break;

  85202. }

  85203. 

  85204. /* Opcode: ResultRow P1 P2 * * *

  85205. ** Synopsis: output=r[P1@P2]

  85206. **

  85207. ** The registers P1 through P1+P2-1 contain a single row of

  85208. ** results. This opcode causes the sqlite3_step() call to terminate

  85209. ** with an SQLITE_ROW return code and it sets up the sqlite3_stmt

  85210. ** structure to provide access to the r(P1)..r(P1+P2-1) values as

  85211. ** the result row.

  85212. */

  85213. case OP_ResultRow: {

  85214.   Mem *pMem;

  85215.   int i;

  85216.   assert( p->nResColumn==pOp->p2 );

  85217.   assert( pOp->p1>0 );

  85218.   assert( pOp->p1+pOp->p2<=(p->nMem+1 - p->nCursor)+1 );

  85219. 

  85220.   /* If this statement has violated immediate foreign key constraints, do

  85221.   ** not return the number of rows modified. And do not RELEASE the statement

  85222.   ** transaction. It needs to be rolled back.  */

  85223.   if( SQLITE_OK!=(rc = sqlite3VdbeCheckFk(p, 0)) ){

  85224.     assert( db->flags&SQLITE_CountRows );

  85225.     assert( p->usesStmtJournal );

  85226.     goto abort_due_to_error;

  85227.   }

  85228. 

  85229.   /* If the SQLITE_CountRows flag is set in sqlite3.flags mask, then 

  85230.   ** DML statements invoke this opcode to return the number of rows 

  85231.   ** modified to the user. This is the only way that a VM that

  85232.   ** opens a statement transaction may invoke this opcode.

  85233.   **

  85234.   ** In case this is such a statement, close any statement transaction

  85235.   ** opened by this VM before returning control to the user. This is to

  85236.   ** ensure that statement-transactions are always nested, not overlapping.

  85237.   ** If the open statement-transaction is not closed here, then the user

  85238.   ** may step another VM that opens its own statement transaction. This

  85239.   ** may lead to overlapping statement transactions.

  85240.   **

  85241.   ** The statement transaction is never a top-level transaction.  Hence

  85242.   ** the RELEASE call below can never fail.

  85243.   */

  85244.   assert( p->iStatement==0 || db->flags&SQLITE_CountRows );

  85245.   rc = sqlite3VdbeCloseStatement(p, SAVEPOINT_RELEASE);

  85246.   assert( rc==SQLITE_OK );

  85247. 

  85248.   /* Invalidate all ephemeral cursor row caches */

  85249.   p->cacheCtr = (p->cacheCtr + 2)|1;

  85250. 

  85251.   /* Make sure the results of the current row are \000 terminated

  85252.   ** and have an assigned type.  The results are de-ephemeralized as

  85253.   ** a side effect.

  85254.   */

  85255.   pMem = p->pResultSet = &aMem[pOp->p1];

  85256.   for(i=0; i<pOp->p2; i++){

  85257.     assert( memIsValid(&pMem[i]) );

  85258.     Deephemeralize(&pMem[i]);

  85259.     assert( (pMem[i].flags & MEM_Ephem)==0

  85260.             || (pMem[i].flags & (MEM_Str|MEM_Blob))==0 );

  85261.     sqlite3VdbeMemNulTerminate(&pMem[i]);

  85262.     REGISTER_TRACE(pOp->p1+i, &pMem[i]);

  85263.   }

  85264.   if( db->mallocFailed ) goto no_mem;

  85265. 

  85266.   if( db->mTrace & SQLITE_TRACE_ROW ){

  85267.     db->xTrace(SQLITE_TRACE_ROW, db->pTraceArg, p, 0);

  85268.   }

  85269. 

  85270.   /* Return SQLITE_ROW

  85271.   */

  85272.   p->pc = (int)(pOp - aOp) + 1;

  85273.   rc = SQLITE_ROW;

  85274.   goto vdbe_return;

  85275. }

  85276. 

  85277. /* Opcode: Concat P1 P2 P3 * *

  85278. ** Synopsis: r[P3]=r[P2]+r[P1]

  85279. **

  85280. ** Add the text in register P1 onto the end of the text in

  85281. ** register P2 and store the result in register P3.

  85282. ** If either the P1 or P2 text are NULL then store NULL in P3.

  85283. **

  85284. **   P3 = P2 || P1

  85285. **

  85286. ** It is illegal for P1 and P3 to be the same register. Sometimes,

  85287. ** if P3 is the same register as P2, the implementation is able

  85288. ** to avoid a memcpy().

  85289. */

  85290. case OP_Concat: {           /* same as TK_CONCAT, in1, in2, out3 */

  85291.   i64 nByte;          /* Total size of the output string or blob */

  85292.   u16 flags1;         /* Initial flags for P1 */

  85293.   u16 flags2;         /* Initial flags for P2 */

  85294. 

  85295.   pIn1 = &aMem[pOp->p1];

  85296.   pIn2 = &aMem[pOp->p2];

  85297.   pOut = &aMem[pOp->p3];

  85298.   testcase( pIn1==pIn2 );

  85299.   testcase( pOut==pIn2 );

  85300.   assert( pIn1!=pOut );

  85301.   flags1 = pIn1->flags;

  85302.   testcase( flags1 & MEM_Null );

  85303.   testcase( pIn2->flags & MEM_Null );

  85304.   if( (flags1 | pIn2->flags) & MEM_Null ){

  85305.     sqlite3VdbeMemSetNull(pOut);

  85306.     break;

  85307.   }

  85308.   if( (flags1 & (MEM_Str|MEM_Blob))==0 ){

  85309.     if( sqlite3VdbeMemStringify(pIn1,encoding,0) ) goto no_mem;

  85310.     flags1 = pIn1->flags & ~MEM_Str;

  85311.   }else if( (flags1 & MEM_Zero)!=0 ){

  85312.     if( sqlite3VdbeMemExpandBlob(pIn1) ) goto no_mem;

  85313.     flags1 = pIn1->flags & ~MEM_Str;

  85314.   }

  85315.   flags2 = pIn2->flags;

  85316.   if( (flags2 & (MEM_Str|MEM_Blob))==0 ){

  85317.     if( sqlite3VdbeMemStringify(pIn2,encoding,0) ) goto no_mem;

  85318.     flags2 = pIn2->flags & ~MEM_Str;

  85319.   }else if( (flags2 & MEM_Zero)!=0 ){

  85320.     if( sqlite3VdbeMemExpandBlob(pIn2) ) goto no_mem;

  85321.     flags2 = pIn2->flags & ~MEM_Str;

  85322.   }

  85323.   nByte = pIn1->n + pIn2->n;

  85324.   if( nByte>db->aLimit[SQLITE_LIMIT_LENGTH] ){

  85325.     goto too_big;

  85326.   }

  85327.   if( sqlite3VdbeMemGrow(pOut, (int)nByte+3, pOut==pIn2) ){

  85328.     goto no_mem;

  85329.   }

  85330.   MemSetTypeFlag(pOut, MEM_Str);

  85331.   if( pOut!=pIn2 ){

  85332.     memcpy(pOut->z, pIn2->z, pIn2->n);

  85333.     assert( (pIn2->flags & MEM_Dyn) == (flags2 & MEM_Dyn) );

  85334.     pIn2->flags = flags2;

  85335.   }

  85336.   memcpy(&pOut->z[pIn2->n], pIn1->z, pIn1->n);

  85337.   assert( (pIn1->flags & MEM_Dyn) == (flags1 & MEM_Dyn) );

  85338.   pIn1->flags = flags1;

  85339.   pOut->z[nByte]=0;

  85340.   pOut->z[nByte+1] = 0;

  85341.   pOut->z[nByte+2] = 0;

  85342.   pOut->flags |= MEM_Term;

  85343.   pOut->n = (int)nByte;

  85344.   pOut->enc = encoding;

  85345.   UPDATE_MAX_BLOBSIZE(pOut);

  85346.   break;

  85347. }

  85348. 

  85349. /* Opcode: Add P1 P2 P3 * *

  85350. ** Synopsis: r[P3]=r[P1]+r[P2]

  85351. **

  85352. ** Add the value in register P1 to the value in register P2

  85353. ** and store the result in register P3.

  85354. ** If either input is NULL, the result is NULL.

  85355. */

  85356. /* Opcode: Multiply P1 P2 P3 * *

  85357. ** Synopsis: r[P3]=r[P1]*r[P2]

  85358. **

  85359. **

  85360. ** Multiply the value in register P1 by the value in register P2

  85361. ** and store the result in register P3.

  85362. ** If either input is NULL, the result is NULL.

  85363. */

  85364. /* Opcode: Subtract P1 P2 P3 * *

  85365. ** Synopsis: r[P3]=r[P2]-r[P1]

  85366. **

  85367. ** Subtract the value in register P1 from the value in register P2

  85368. ** and store the result in register P3.

  85369. ** If either input is NULL, the result is NULL.

  85370. */

  85371. /* Opcode: Divide P1 P2 P3 * *

  85372. ** Synopsis: r[P3]=r[P2]/r[P1]

  85373. **

  85374. ** Divide the value in register P1 by the value in register P2

  85375. ** and store the result in register P3 (P3=P2/P1). If the value in 

  85376. ** register P1 is zero, then the result is NULL. If either input is 

  85377. ** NULL, the result is NULL.

  85378. */

  85379. /* Opcode: Remainder P1 P2 P3 * *

  85380. ** Synopsis: r[P3]=r[P2]%r[P1]

  85381. **

  85382. ** Compute the remainder after integer register P2 is divided by 

  85383. ** register P1 and store the result in register P3. 

  85384. ** If the value in register P1 is zero the result is NULL.

  85385. ** If either operand is NULL, the result is NULL.

  85386. */

  85387. case OP_Add:                   /* same as TK_PLUS, in1, in2, out3 */

  85388. case OP_Subtract:              /* same as TK_MINUS, in1, in2, out3 */

  85389. case OP_Multiply:              /* same as TK_STAR, in1, in2, out3 */

  85390. case OP_Divide:                /* same as TK_SLASH, in1, in2, out3 */

  85391. case OP_Remainder: {           /* same as TK_REM, in1, in2, out3 */

  85392.   u16 flags;      /* Combined MEM_* flags from both inputs */

  85393.   u16 type1;      /* Numeric type of left operand */

  85394.   u16 type2;      /* Numeric type of right operand */

  85395.   i64 iA;         /* Integer value of left operand */

  85396.   i64 iB;         /* Integer value of right operand */

  85397.   double rA;      /* Real value of left operand */

  85398.   double rB;      /* Real value of right operand */

  85399. 

  85400.   pIn1 = &aMem[pOp->p1];

  85401.   type1 = numericType(pIn1);

  85402.   pIn2 = &aMem[pOp->p2];

  85403.   type2 = numericType(pIn2);

  85404.   pOut = &aMem[pOp->p3];

  85405.   flags = pIn1->flags | pIn2->flags;

  85406.   if( (type1 & type2 & MEM_Int)!=0 ){

  85407.     iA = pIn1->u.i;

  85408.     iB = pIn2->u.i;

  85409.     switch( pOp->opcode ){

  85410.       case OP_Add:       if( sqlite3AddInt64(&iB,iA) ) goto fp_math;  break;

  85411.       case OP_Subtract:  if( sqlite3SubInt64(&iB,iA) ) goto fp_math;  break;

  85412.       case OP_Multiply:  if( sqlite3MulInt64(&iB,iA) ) goto fp_math;  break;

  85413.       case OP_Divide: {

  85414.         if( iA==0 ) goto arithmetic_result_is_null;

  85415.         if( iA==-1 && iB==SMALLEST_INT64 ) goto fp_math;

  85416.         iB /= iA;

  85417.         break;

  85418.       }

  85419.       default: {

  85420.         if( iA==0 ) goto arithmetic_result_is_null;

  85421.         if( iA==-1 ) iA = 1;

  85422.         iB %= iA;

  85423.         break;

  85424.       }

  85425.     }

  85426.     pOut->u.i = iB;

  85427.     MemSetTypeFlag(pOut, MEM_Int);

  85428.   }else if( (flags & MEM_Null)!=0 ){

  85429.     goto arithmetic_result_is_null;

  85430.   }else{

  85431. fp_math:

  85432.     rA = sqlite3VdbeRealValue(pIn1);

  85433.     rB = sqlite3VdbeRealValue(pIn2);

  85434.     switch( pOp->opcode ){

  85435.       case OP_Add:         rB += rA;       break;

  85436.       case OP_Subtract:    rB -= rA;       break;

  85437.       case OP_Multiply:    rB *= rA;       break;

  85438.       case OP_Divide: {

  85439.         /* (double)0 In case of SQLITE_OMIT_FLOATING_POINT... */

  85440.         if( rA==(double)0 ) goto arithmetic_result_is_null;

  85441.         rB /= rA;

  85442.         break;

  85443.       }

  85444.       default: {

  85445.         iA = sqlite3VdbeIntValue(pIn1);

  85446.         iB = sqlite3VdbeIntValue(pIn2);

  85447.         if( iA==0 ) goto arithmetic_result_is_null;

  85448.         if( iA==-1 ) iA = 1;

  85449.         rB = (double)(iB % iA);

  85450.         break;

  85451.       }

  85452.     }

  85453. #ifdef SQLITE_OMIT_FLOATING_POINT

  85454.     pOut->u.i = rB;

  85455.     MemSetTypeFlag(pOut, MEM_Int);

  85456. #else

  85457.     if( sqlite3IsNaN(rB) ){

  85458.       goto arithmetic_result_is_null;

  85459.     }

  85460.     pOut->u.r = rB;

  85461.     MemSetTypeFlag(pOut, MEM_Real);

  85462. #endif

  85463.   }

  85464.   break;

  85465. 

  85466. arithmetic_result_is_null:

  85467.   sqlite3VdbeMemSetNull(pOut);

  85468.   break;

  85469. }

  85470. 

  85471. /* Opcode: CollSeq P1 * * P4

  85472. **

  85473. ** P4 is a pointer to a CollSeq object. If the next call to a user function

  85474. ** or aggregate calls sqlite3GetFuncCollSeq(), this collation sequence will

  85475. ** be returned. This is used by the built-in min(), max() and nullif()

  85476. ** functions.

  85477. **

  85478. ** If P1 is not zero, then it is a register that a subsequent min() or

  85479. ** max() aggregate will set to 1 if the current row is not the minimum or

  85480. ** maximum.  The P1 register is initialized to 0 by this instruction.

  85481. **

  85482. ** The interface used by the implementation of the aforementioned functions

  85483. ** to retrieve the collation sequence set by this opcode is not available

  85484. ** publicly.  Only built-in functions have access to this feature.

  85485. */

  85486. case OP_CollSeq: {

  85487.   assert( pOp->p4type==P4_COLLSEQ );

  85488.   if( pOp->p1 ){

  85489.     sqlite3VdbeMemSetInt64(&aMem[pOp->p1], 0);

  85490.   }

  85491.   break;

  85492. }

  85493. 

  85494. /* Opcode: BitAnd P1 P2 P3 * *

  85495. ** Synopsis: r[P3]=r[P1]&r[P2]

  85496. **

  85497. ** Take the bit-wise AND of the values in register P1 and P2 and

  85498. ** store the result in register P3.

  85499. ** If either input is NULL, the result is NULL.

  85500. */

  85501. /* Opcode: BitOr P1 P2 P3 * *

  85502. ** Synopsis: r[P3]=r[P1]|r[P2]

  85503. **

  85504. ** Take the bit-wise OR of the values in register P1 and P2 and

  85505. ** store the result in register P3.

  85506. ** If either input is NULL, the result is NULL.

  85507. */

  85508. /* Opcode: ShiftLeft P1 P2 P3 * *

  85509. ** Synopsis: r[P3]=r[P2]<<r[P1]

  85510. **

  85511. ** Shift the integer value in register P2 to the left by the

  85512. ** number of bits specified by the integer in register P1.

  85513. ** Store the result in register P3.

  85514. ** If either input is NULL, the result is NULL.

  85515. */

  85516. /* Opcode: ShiftRight P1 P2 P3 * *

  85517. ** Synopsis: r[P3]=r[P2]>>r[P1]

  85518. **

  85519. ** Shift the integer value in register P2 to the right by the

  85520. ** number of bits specified by the integer in register P1.

  85521. ** Store the result in register P3.

  85522. ** If either input is NULL, the result is NULL.

  85523. */

  85524. case OP_BitAnd:                 /* same as TK_BITAND, in1, in2, out3 */

  85525. case OP_BitOr:                  /* same as TK_BITOR, in1, in2, out3 */

  85526. case OP_ShiftLeft:              /* same as TK_LSHIFT, in1, in2, out3 */

  85527. case OP_ShiftRight: {           /* same as TK_RSHIFT, in1, in2, out3 */

  85528.   i64 iA;

  85529.   u64 uA;

  85530.   i64 iB;

  85531.   u8 op;

  85532. 

  85533.   pIn1 = &aMem[pOp->p1];

  85534.   pIn2 = &aMem[pOp->p2];

  85535.   pOut = &aMem[pOp->p3];

  85536.   if( (pIn1->flags | pIn2->flags) & MEM_Null ){

  85537.     sqlite3VdbeMemSetNull(pOut);

  85538.     break;

  85539.   }

  85540.   iA = sqlite3VdbeIntValue(pIn2);

  85541.   iB = sqlite3VdbeIntValue(pIn1);

  85542.   op = pOp->opcode;

  85543.   if( op==OP_BitAnd ){

  85544.     iA &= iB;

  85545.   }else if( op==OP_BitOr ){

  85546.     iA |= iB;

  85547.   }else if( iB!=0 ){

  85548.     assert( op==OP_ShiftRight || op==OP_ShiftLeft );

  85549. 

  85550.     /* If shifting by a negative amount, shift in the other direction */

  85551.     if( iB<0 ){

  85552.       assert( OP_ShiftRight==OP_ShiftLeft+1 );

  85553.       op = 2*OP_ShiftLeft + 1 - op;

  85554.       iB = iB>(-64) ? -iB : 64;

  85555.     }

  85556. 

  85557.     if( iB>=64 ){

  85558.       iA = (iA>=0 || op==OP_ShiftLeft) ? 0 : -1;

  85559.     }else{

  85560.       memcpy(&uA, &iA, sizeof(uA));

  85561.       if( op==OP_ShiftLeft ){

  85562.         uA <<= iB;

  85563.       }else{

  85564.         uA >>= iB;

  85565.         /* Sign-extend on a right shift of a negative number */

  85566.         if( iA<0 ) uA |= ((((u64)0xffffffff)<<32)|0xffffffff) << (64-iB);

  85567.       }

  85568.       memcpy(&iA, &uA, sizeof(iA));

  85569.     }

  85570.   }

  85571.   pOut->u.i = iA;

  85572.   MemSetTypeFlag(pOut, MEM_Int);

  85573.   break;

  85574. }

  85575. 

  85576. /* Opcode: AddImm  P1 P2 * * *

  85577. ** Synopsis: r[P1]=r[P1]+P2

  85578. ** 

  85579. ** Add the constant P2 to the value in register P1.

  85580. ** The result is always an integer.

  85581. **

  85582. ** To force any register to be an integer, just add 0.

  85583. */

  85584. case OP_AddImm: {            /* in1 */

  85585.   pIn1 = &aMem[pOp->p1];

  85586.   memAboutToChange(p, pIn1);

  85587.   sqlite3VdbeMemIntegerify(pIn1);

  85588.   pIn1->u.i += pOp->p2;

  85589.   break;

  85590. }

  85591. 

  85592. /* Opcode: MustBeInt P1 P2 * * *

  85593. ** 

  85594. ** Force the value in register P1 to be an integer.  If the value

  85595. ** in P1 is not an integer and cannot be converted into an integer

  85596. ** without data loss, then jump immediately to P2, or if P2==0

  85597. ** raise an SQLITE_MISMATCH exception.

  85598. */

  85599. case OP_MustBeInt: {            /* jump, in1 */

  85600.   pIn1 = &aMem[pOp->p1];

  85601.   if( (pIn1->flags & MEM_Int)==0 ){

  85602.     applyAffinity(pIn1, SQLITE_AFF_NUMERIC, encoding);

  85603.     if( (pIn1->flags & MEM_Int)==0 ){

  85604.       VdbeBranchTaken(1, 2);

  85605.       if( pOp->p2==0 ){

  85606.         rc = SQLITE_MISMATCH;

  85607.         goto abort_due_to_error;

  85608.       }else{

  85609.         goto jump_to_p2;

  85610.       }

  85611.     }

  85612.   }

  85613.   VdbeBranchTaken(0, 2);

  85614.   MemSetTypeFlag(pIn1, MEM_Int);

  85615.   break;

  85616. }

  85617. 

  85618. #ifndef SQLITE_OMIT_FLOATING_POINT

  85619. /* Opcode: RealAffinity P1 * * * *

  85620. **

  85621. ** If register P1 holds an integer convert it to a real value.

  85622. **

  85623. ** This opcode is used when extracting information from a column that

  85624. ** has REAL affinity.  Such column values may still be stored as

  85625. ** integers, for space efficiency, but after extraction we want them

  85626. ** to have only a real value.

  85627. */

  85628. case OP_RealAffinity: {                  /* in1 */

  85629.   pIn1 = &aMem[pOp->p1];

  85630.   if( pIn1->flags & (MEM_Int|MEM_IntReal) ){

  85631.     testcase( pIn1->flags & MEM_Int );

  85632.     testcase( pIn1->flags & MEM_IntReal );

  85633.     sqlite3VdbeMemRealify(pIn1);

  85634.   }

  85635.   break;

  85636. }

  85637. #endif

  85638. 

  85639. #ifndef SQLITE_OMIT_CAST

  85640. /* Opcode: Cast P1 P2 * * *

  85641. ** Synopsis: affinity(r[P1])

  85642. **

  85643. ** Force the value in register P1 to be the type defined by P2.

  85644. ** 

  85645. ** <ul>

  85646. ** <li> P2=='A' &rarr; BLOB

  85647. ** <li> P2=='B' &rarr; TEXT

  85648. ** <li> P2=='C' &rarr; NUMERIC

  85649. ** <li> P2=='D' &rarr; INTEGER

  85650. ** <li> P2=='E' &rarr; REAL

  85651. ** </ul>

  85652. **

  85653. ** A NULL value is not changed by this routine.  It remains NULL.

  85654. */

  85655. case OP_Cast: {                  /* in1 */

  85656.   assert( pOp->p2>=SQLITE_AFF_BLOB && pOp->p2<=SQLITE_AFF_REAL );

  85657.   testcase( pOp->p2==SQLITE_AFF_TEXT );

  85658.   testcase( pOp->p2==SQLITE_AFF_BLOB );

  85659.   testcase( pOp->p2==SQLITE_AFF_NUMERIC );

  85660.   testcase( pOp->p2==SQLITE_AFF_INTEGER );

  85661.   testcase( pOp->p2==SQLITE_AFF_REAL );

  85662.   pIn1 = &aMem[pOp->p1];

  85663.   memAboutToChange(p, pIn1);

  85664.   rc = ExpandBlob(pIn1);

  85665.   sqlite3VdbeMemCast(pIn1, pOp->p2, encoding);

  85666.   UPDATE_MAX_BLOBSIZE(pIn1);

  85667.   if( rc ) goto abort_due_to_error;

  85668.   break;

  85669. }

  85670. #endif /* SQLITE_OMIT_CAST */

  85671. 

  85672. /* Opcode: Eq P1 P2 P3 P4 P5

  85673. ** Synopsis: IF r[P3]==r[P1]

  85674. **

  85675. ** Compare the values in register P1 and P3.  If reg(P3)==reg(P1) then

  85676. ** jump to address P2.  Or if the SQLITE_STOREP2 flag is set in P5, then

  85677. ** store the result of comparison in register P2.

  85678. **

  85679. ** The SQLITE_AFF_MASK portion of P5 must be an affinity character -

  85680. ** SQLITE_AFF_TEXT, SQLITE_AFF_INTEGER, and so forth. An attempt is made 

  85681. ** to coerce both inputs according to this affinity before the

  85682. ** comparison is made. If the SQLITE_AFF_MASK is 0x00, then numeric

  85683. ** affinity is used. Note that the affinity conversions are stored

  85684. ** back into the input registers P1 and P3.  So this opcode can cause

  85685. ** persistent changes to registers P1 and P3.

  85686. **

  85687. ** Once any conversions have taken place, and neither value is NULL, 

  85688. ** the values are compared. If both values are blobs then memcmp() is

  85689. ** used to determine the results of the comparison.  If both values

  85690. ** are text, then the appropriate collating function specified in

  85691. ** P4 is used to do the comparison.  If P4 is not specified then

  85692. ** memcmp() is used to compare text string.  If both values are

  85693. ** numeric, then a numeric comparison is used. If the two values

  85694. ** are of different types, then numbers are considered less than

  85695. ** strings and strings are considered less than blobs.

  85696. **

  85697. ** If SQLITE_NULLEQ is set in P5 then the result of comparison is always either

  85698. ** true or false and is never NULL.  If both operands are NULL then the result

  85699. ** of comparison is true.  If either operand is NULL then the result is false.

  85700. ** If neither operand is NULL the result is the same as it would be if

  85701. ** the SQLITE_NULLEQ flag were omitted from P5.

  85702. **

  85703. ** If both SQLITE_STOREP2 and SQLITE_KEEPNULL flags are set then the

  85704. ** content of r[P2] is only changed if the new value is NULL or 0 (false).

  85705. ** In other words, a prior r[P2] value will not be overwritten by 1 (true).

  85706. */

  85707. /* Opcode: Ne P1 P2 P3 P4 P5

  85708. ** Synopsis: IF r[P3]!=r[P1]

  85709. **

  85710. ** This works just like the Eq opcode except that the jump is taken if

  85711. ** the operands in registers P1 and P3 are not equal.  See the Eq opcode for

  85712. ** additional information.

  85713. **

  85714. ** If both SQLITE_STOREP2 and SQLITE_KEEPNULL flags are set then the

  85715. ** content of r[P2] is only changed if the new value is NULL or 1 (true).

  85716. ** In other words, a prior r[P2] value will not be overwritten by 0 (false).

  85717. */

  85718. /* Opcode: Lt P1 P2 P3 P4 P5

  85719. ** Synopsis: IF r[P3]<r[P1]

  85720. **

  85721. ** Compare the values in register P1 and P3.  If reg(P3)<reg(P1) then

  85722. ** jump to address P2.  Or if the SQLITE_STOREP2 flag is set in P5 store

  85723. ** the result of comparison (0 or 1 or NULL) into register P2.

  85724. **

  85725. ** If the SQLITE_JUMPIFNULL bit of P5 is set and either reg(P1) or

  85726. ** reg(P3) is NULL then the take the jump.  If the SQLITE_JUMPIFNULL 

  85727. ** bit is clear then fall through if either operand is NULL.

  85728. **

  85729. ** The SQLITE_AFF_MASK portion of P5 must be an affinity character -

  85730. ** SQLITE_AFF_TEXT, SQLITE_AFF_INTEGER, and so forth. An attempt is made 

  85731. ** to coerce both inputs according to this affinity before the

  85732. ** comparison is made. If the SQLITE_AFF_MASK is 0x00, then numeric

  85733. ** affinity is used. Note that the affinity conversions are stored

  85734. ** back into the input registers P1 and P3.  So this opcode can cause

  85735. ** persistent changes to registers P1 and P3.

  85736. **

  85737. ** Once any conversions have taken place, and neither value is NULL, 

  85738. ** the values are compared. If both values are blobs then memcmp() is

  85739. ** used to determine the results of the comparison.  If both values

  85740. ** are text, then the appropriate collating function specified in

  85741. ** P4 is  used to do the comparison.  If P4 is not specified then

  85742. ** memcmp() is used to compare text string.  If both values are

  85743. ** numeric, then a numeric comparison is used. If the two values

  85744. ** are of different types, then numbers are considered less than

  85745. ** strings and strings are considered less than blobs.

  85746. */

  85747. /* Opcode: Le P1 P2 P3 P4 P5

  85748. ** Synopsis: IF r[P3]<=r[P1]

  85749. **

  85750. ** This works just like the Lt opcode except that the jump is taken if

  85751. ** the content of register P3 is less than or equal to the content of

  85752. ** register P1.  See the Lt opcode for additional information.

  85753. */

  85754. /* Opcode: Gt P1 P2 P3 P4 P5

  85755. ** Synopsis: IF r[P3]>r[P1]

  85756. **

  85757. ** This works just like the Lt opcode except that the jump is taken if

  85758. ** the content of register P3 is greater than the content of

  85759. ** register P1.  See the Lt opcode for additional information.

  85760. */

  85761. /* Opcode: Ge P1 P2 P3 P4 P5

  85762. ** Synopsis: IF r[P3]>=r[P1]

  85763. **

  85764. ** This works just like the Lt opcode except that the jump is taken if

  85765. ** the content of register P3 is greater than or equal to the content of

  85766. ** register P1.  See the Lt opcode for additional information.

  85767. */

  85768. case OP_Eq:               /* same as TK_EQ, jump, in1, in3 */

  85769. case OP_Ne:               /* same as TK_NE, jump, in1, in3 */

  85770. case OP_Lt:               /* same as TK_LT, jump, in1, in3 */

  85771. case OP_Le:               /* same as TK_LE, jump, in1, in3 */

  85772. case OP_Gt:               /* same as TK_GT, jump, in1, in3 */

  85773. case OP_Ge: {             /* same as TK_GE, jump, in1, in3 */

  85774.   int res, res2;      /* Result of the comparison of pIn1 against pIn3 */

  85775.   char affinity;      /* Affinity to use for comparison */

  85776.   u16 flags1;         /* Copy of initial value of pIn1->flags */

  85777.   u16 flags3;         /* Copy of initial value of pIn3->flags */

  85778. 

  85779.   pIn1 = &aMem[pOp->p1];

  85780.   pIn3 = &aMem[pOp->p3];

  85781.   flags1 = pIn1->flags;

  85782.   flags3 = pIn3->flags;

  85783.   if( (flags1 | flags3)&MEM_Null ){

  85784.     /* One or both operands are NULL */

  85785.     if( pOp->p5 & SQLITE_NULLEQ ){

  85786.       /* If SQLITE_NULLEQ is set (which will only happen if the operator is

  85787.       ** OP_Eq or OP_Ne) then take the jump or not depending on whether

  85788.       ** or not both operands are null.

  85789.       */

  85790.       assert( (flags1 & MEM_Cleared)==0 );

  85791.       assert( (pOp->p5 & SQLITE_JUMPIFNULL)==0 || CORRUPT_DB );

  85792.       testcase( (pOp->p5 & SQLITE_JUMPIFNULL)!=0 );

  85793.       if( (flags1&flags3&MEM_Null)!=0

  85794.        && (flags3&MEM_Cleared)==0

  85795.       ){

  85796.         res = 0;  /* Operands are equal */

  85797.       }else{

  85798.         res = ((flags3 & MEM_Null) ? -1 : +1);  /* Operands are not equal */

  85799.       }

  85800.     }else{

  85801.       /* SQLITE_NULLEQ is clear and at least one operand is NULL,

  85802.       ** then the result is always NULL.

  85803.       ** The jump is taken if the SQLITE_JUMPIFNULL bit is set.

  85804.       */

  85805.       if( pOp->p5 & SQLITE_STOREP2 ){

  85806.         pOut = &aMem[pOp->p2];

  85807.         iCompare = 1;    /* Operands are not equal */

  85808.         memAboutToChange(p, pOut);

  85809.         MemSetTypeFlag(pOut, MEM_Null);

  85810.         REGISTER_TRACE(pOp->p2, pOut);

  85811.       }else{

  85812.         VdbeBranchTaken(2,3);

  85813.         if( pOp->p5 & SQLITE_JUMPIFNULL ){

  85814.           goto jump_to_p2;

  85815.         }

  85816.       }

  85817.       break;

  85818.     }

  85819.   }else{

  85820.     /* Neither operand is NULL.  Do a comparison. */

  85821.     affinity = pOp->p5 & SQLITE_AFF_MASK;

  85822.     if( affinity>=SQLITE_AFF_NUMERIC ){

  85823.       if( (flags1 | flags3)&MEM_Str ){

  85824.         if( (flags1 & (MEM_Int|MEM_IntReal|MEM_Real|MEM_Str))==MEM_Str ){

  85825.           applyNumericAffinity(pIn1,0);

  85826.           assert( flags3==pIn3->flags );

  85827.           /* testcase( flags3!=pIn3->flags );

  85828.           ** this used to be possible with pIn1==pIn3, but not since

  85829.           ** the column cache was removed.  The following assignment

  85830.           ** is essentially a no-op.  But, it provides defense-in-depth

  85831.           ** in case our analysis is incorrect, so it is left in. */

  85832.           flags3 = pIn3->flags;

  85833.         }

  85834.         if( (flags3 & (MEM_Int|MEM_IntReal|MEM_Real|MEM_Str))==MEM_Str ){

  85835.           applyNumericAffinity(pIn3,0);

  85836.         }

  85837.       }

  85838.       /* Handle the common case of integer comparison here, as an

  85839.       ** optimization, to avoid a call to sqlite3MemCompare() */

  85840.       if( (pIn1->flags & pIn3->flags & MEM_Int)!=0 ){

  85841.         if( pIn3->u.i > pIn1->u.i ){ res = +1; goto compare_op; }

  85842.         if( pIn3->u.i < pIn1->u.i ){ res = -1; goto compare_op; }

  85843.         res = 0;

  85844.         goto compare_op;

  85845.       }

  85846.     }else if( affinity==SQLITE_AFF_TEXT ){

  85847.       if( (flags1 & MEM_Str)==0 && (flags1&(MEM_Int|MEM_Real|MEM_IntReal))!=0 ){

  85848.         testcase( pIn1->flags & MEM_Int );

  85849.         testcase( pIn1->flags & MEM_Real );

  85850.         testcase( pIn1->flags & MEM_IntReal );

  85851.         sqlite3VdbeMemStringify(pIn1, encoding, 1);

  85852.         testcase( (flags1&MEM_Dyn) != (pIn1->flags&MEM_Dyn) );

  85853.         flags1 = (pIn1->flags & ~MEM_TypeMask) | (flags1 & MEM_TypeMask);

  85854.         assert( pIn1!=pIn3 );

  85855.       }

  85856.       if( (flags3 & MEM_Str)==0 && (flags3&(MEM_Int|MEM_Real|MEM_IntReal))!=0 ){

  85857.         testcase( pIn3->flags & MEM_Int );

  85858.         testcase( pIn3->flags & MEM_Real );

  85859.         testcase( pIn3->flags & MEM_IntReal );

  85860.         sqlite3VdbeMemStringify(pIn3, encoding, 1);

  85861.         testcase( (flags3&MEM_Dyn) != (pIn3->flags&MEM_Dyn) );

  85862.         flags3 = (pIn3->flags & ~MEM_TypeMask) | (flags3 & MEM_TypeMask);

  85863.       }

  85864.     }

  85865.     assert( pOp->p4type==P4_COLLSEQ || pOp->p4.pColl==0 );

  85866.     res = sqlite3MemCompare(pIn3, pIn1, pOp->p4.pColl);

  85867.   }

  85868. compare_op:

  85869.   /* At this point, res is negative, zero, or positive if reg[P1] is

  85870.   ** less than, equal to, or greater than reg[P3], respectively.  Compute

  85871.   ** the answer to this operator in res2, depending on what the comparison

  85872.   ** operator actually is.  The next block of code depends on the fact

  85873.   ** that the 6 comparison operators are consecutive integers in this

  85874.   ** order:  NE, EQ, GT, LE, LT, GE */

  85875.   assert( OP_Eq==OP_Ne+1 ); assert( OP_Gt==OP_Ne+2 ); assert( OP_Le==OP_Ne+3 );

  85876.   assert( OP_Lt==OP_Ne+4 ); assert( OP_Ge==OP_Ne+5 );

  85877.   if( res<0 ){                        /* ne, eq, gt, le, lt, ge */

  85878.     static const unsigned char aLTb[] = { 1,  0,  0,  1,  1,  0 };

  85879.     res2 = aLTb[pOp->opcode - OP_Ne];

  85880.   }else if( res==0 ){

  85881.     static const unsigned char aEQb[] = { 0,  1,  0,  1,  0,  1 };

  85882.     res2 = aEQb[pOp->opcode - OP_Ne];

  85883.   }else{

  85884.     static const unsigned char aGTb[] = { 1,  0,  1,  0,  0,  1 };

  85885.     res2 = aGTb[pOp->opcode - OP_Ne];

  85886.   }

  85887. 

  85888.   /* Undo any changes made by applyAffinity() to the input registers. */

  85889.   assert( (pIn1->flags & MEM_Dyn) == (flags1 & MEM_Dyn) );

  85890.   pIn1->flags = flags1;

  85891.   assert( (pIn3->flags & MEM_Dyn) == (flags3 & MEM_Dyn) );

  85892.   pIn3->flags = flags3;

  85893. 

  85894.   if( pOp->p5 & SQLITE_STOREP2 ){

  85895.     pOut = &aMem[pOp->p2];

  85896.     iCompare = res;

  85897.     if( (pOp->p5 & SQLITE_KEEPNULL)!=0 ){

  85898.       /* The KEEPNULL flag prevents OP_Eq from overwriting a NULL with 1

  85899.       ** and prevents OP_Ne from overwriting NULL with 0.  This flag

  85900.       ** is only used in contexts where either:

  85901.       **   (1) op==OP_Eq && (r[P2]==NULL || r[P2]==0)

  85902.       **   (2) op==OP_Ne && (r[P2]==NULL || r[P2]==1)

  85903.       ** Therefore it is not necessary to check the content of r[P2] for

  85904.       ** NULL. */

  85905.       assert( pOp->opcode==OP_Ne || pOp->opcode==OP_Eq );

  85906.       assert( res2==0 || res2==1 );

  85907.       testcase( res2==0 && pOp->opcode==OP_Eq );

  85908.       testcase( res2==1 && pOp->opcode==OP_Eq );

  85909.       testcase( res2==0 && pOp->opcode==OP_Ne );

  85910.       testcase( res2==1 && pOp->opcode==OP_Ne );

  85911.       if( (pOp->opcode==OP_Eq)==res2 ) break;

  85912.     }

  85913.     memAboutToChange(p, pOut);

  85914.     MemSetTypeFlag(pOut, MEM_Int);

  85915.     pOut->u.i = res2;

  85916.     REGISTER_TRACE(pOp->p2, pOut);

  85917.   }else{

  85918.     VdbeBranchTaken(res2!=0, (pOp->p5 & SQLITE_NULLEQ)?2:3);

  85919.     if( res2 ){

  85920.       goto jump_to_p2;

  85921.     }

  85922.   }

  85923.   break;

  85924. }

  85925. 

  85926. /* Opcode: ElseNotEq * P2 * * *

  85927. **

  85928. ** This opcode must immediately follow an OP_Lt or OP_Gt comparison operator.

  85929. ** If result of an OP_Eq comparison on the same two operands

  85930. ** would have be NULL or false (0), then then jump to P2. 

  85931. ** If the result of an OP_Eq comparison on the two previous operands

  85932. ** would have been true (1), then fall through.

  85933. */

  85934. case OP_ElseNotEq: {       /* same as TK_ESCAPE, jump */

  85935.   assert( pOp>aOp );

  85936.   assert( pOp[-1].opcode==OP_Lt || pOp[-1].opcode==OP_Gt );

  85937.   assert( pOp[-1].p5 & SQLITE_STOREP2 );

  85938.   VdbeBranchTaken(iCompare!=0, 2);

  85939.   if( iCompare!=0 ) goto jump_to_p2;

  85940.   break;

  85941. }

  85942. 

  85943. 

  85944. /* Opcode: Permutation * * * P4 *

  85945. **

  85946. ** Set the permutation used by the OP_Compare operator in the next

  85947. ** instruction.  The permutation is stored in the P4 operand.

  85948. **

  85949. ** The permutation is only valid until the next OP_Compare that has

  85950. ** the OPFLAG_PERMUTE bit set in P5. Typically the OP_Permutation should 

  85951. ** occur immediately prior to the OP_Compare.

  85952. **

  85953. ** The first integer in the P4 integer array is the length of the array

  85954. ** and does not become part of the permutation.

  85955. */

  85956. case OP_Permutation: {

  85957.   assert( pOp->p4type==P4_INTARRAY );

  85958.   assert( pOp->p4.ai );

  85959.   assert( pOp[1].opcode==OP_Compare );

  85960.   assert( pOp[1].p5 & OPFLAG_PERMUTE );

  85961.   break;

  85962. }

  85963. 

  85964. /* Opcode: Compare P1 P2 P3 P4 P5

  85965. ** Synopsis: r[P1@P3] <-> r[P2@P3]

  85966. **

  85967. ** Compare two vectors of registers in reg(P1)..reg(P1+P3-1) (call this

  85968. ** vector "A") and in reg(P2)..reg(P2+P3-1) ("B").  Save the result of

  85969. ** the comparison for use by the next OP_Jump instruct.

  85970. **

  85971. ** If P5 has the OPFLAG_PERMUTE bit set, then the order of comparison is

  85972. ** determined by the most recent OP_Permutation operator.  If the

  85973. ** OPFLAG_PERMUTE bit is clear, then register are compared in sequential

  85974. ** order.

  85975. **

  85976. ** P4 is a KeyInfo structure that defines collating sequences and sort

  85977. ** orders for the comparison.  The permutation applies to registers

  85978. ** only.  The KeyInfo elements are used sequentially.

  85979. **

  85980. ** The comparison is a sort comparison, so NULLs compare equal,

  85981. ** NULLs are less than numbers, numbers are less than strings,

  85982. ** and strings are less than blobs.

  85983. */

  85984. case OP_Compare: {

  85985.   int n;

  85986.   int i;

  85987.   int p1;

  85988.   int p2;

  85989.   const KeyInfo *pKeyInfo;

  85990.   int idx;

  85991.   CollSeq *pColl;    /* Collating sequence to use on this term */

  85992.   int bRev;          /* True for DESCENDING sort order */

  85993.   int *aPermute;     /* The permutation */

  85994. 

  85995.   if( (pOp->p5 & OPFLAG_PERMUTE)==0 ){

  85996.     aPermute = 0;

  85997.   }else{

  85998.     assert( pOp>aOp );

  85999.     assert( pOp[-1].opcode==OP_Permutation );

  86000.     assert( pOp[-1].p4type==P4_INTARRAY );

  86001.     aPermute = pOp[-1].p4.ai + 1;

  86002.     assert( aPermute!=0 );

  86003.   }

  86004.   n = pOp->p3;

  86005.   pKeyInfo = pOp->p4.pKeyInfo;

  86006.   assert( n>0 );

  86007.   assert( pKeyInfo!=0 );

  86008.   p1 = pOp->p1;

  86009.   p2 = pOp->p2;

  86010. #ifdef SQLITE_DEBUG

  86011.   if( aPermute ){

  86012.     int k, mx = 0;

  86013.     for(k=0; k<n; k++) if( aPermute[k]>mx ) mx = aPermute[k];

  86014.     assert( p1>0 && p1+mx<=(p->nMem+1 - p->nCursor)+1 );

  86015.     assert( p2>0 && p2+mx<=(p->nMem+1 - p->nCursor)+1 );

  86016.   }else{

  86017.     assert( p1>0 && p1+n<=(p->nMem+1 - p->nCursor)+1 );

  86018.     assert( p2>0 && p2+n<=(p->nMem+1 - p->nCursor)+1 );

  86019.   }

  86020. #endif /* SQLITE_DEBUG */

  86021.   for(i=0; i<n; i++){

  86022.     idx = aPermute ? aPermute[i] : i;

  86023.     assert( memIsValid(&aMem[p1+idx]) );

  86024.     assert( memIsValid(&aMem[p2+idx]) );

  86025.     REGISTER_TRACE(p1+idx, &aMem[p1+idx]);

  86026.     REGISTER_TRACE(p2+idx, &aMem[p2+idx]);

  86027.     assert( i<pKeyInfo->nKeyField );

  86028.     pColl = pKeyInfo->aColl[i];

  86029.     bRev = pKeyInfo->aSortOrder[i];

  86030.     iCompare = sqlite3MemCompare(&aMem[p1+idx], &aMem[p2+idx], pColl);

  86031.     if( iCompare ){

  86032.       if( bRev ) iCompare = -iCompare;

  86033.       break;

  86034.     }

  86035.   }

  86036.   break;

  86037. }

  86038. 

  86039. /* Opcode: Jump P1 P2 P3 * *

  86040. **

  86041. ** Jump to the instruction at address P1, P2, or P3 depending on whether

  86042. ** in the most recent OP_Compare instruction the P1 vector was less than

  86043. ** equal to, or greater than the P2 vector, respectively.

  86044. */

  86045. case OP_Jump: {             /* jump */

  86046.   if( iCompare<0 ){

  86047.     VdbeBranchTaken(0,4); pOp = &aOp[pOp->p1 - 1];

  86048.   }else if( iCompare==0 ){

  86049.     VdbeBranchTaken(1,4); pOp = &aOp[pOp->p2 - 1];

  86050.   }else{

  86051.     VdbeBranchTaken(2,4); pOp = &aOp[pOp->p3 - 1];

  86052.   }

  86053.   break;

  86054. }

  86055. 

  86056. /* Opcode: And P1 P2 P3 * *

  86057. ** Synopsis: r[P3]=(r[P1] && r[P2])

  86058. **

  86059. ** Take the logical AND of the values in registers P1 and P2 and

  86060. ** write the result into register P3.

  86061. **

  86062. ** If either P1 or P2 is 0 (false) then the result is 0 even if

  86063. ** the other input is NULL.  A NULL and true or two NULLs give

  86064. ** a NULL output.

  86065. */

  86066. /* Opcode: Or P1 P2 P3 * *

  86067. ** Synopsis: r[P3]=(r[P1] || r[P2])

  86068. **

  86069. ** Take the logical OR of the values in register P1 and P2 and

  86070. ** store the answer in register P3.

  86071. **

  86072. ** If either P1 or P2 is nonzero (true) then the result is 1 (true)

  86073. ** even if the other input is NULL.  A NULL and false or two NULLs

  86074. ** give a NULL output.

  86075. */

  86076. case OP_And:              /* same as TK_AND, in1, in2, out3 */

  86077. case OP_Or: {             /* same as TK_OR, in1, in2, out3 */

  86078.   int v1;    /* Left operand:  0==FALSE, 1==TRUE, 2==UNKNOWN or NULL */

  86079.   int v2;    /* Right operand: 0==FALSE, 1==TRUE, 2==UNKNOWN or NULL */

  86080. 

  86081.   v1 = sqlite3VdbeBooleanValue(&aMem[pOp->p1], 2);

  86082.   v2 = sqlite3VdbeBooleanValue(&aMem[pOp->p2], 2);

  86083.   if( pOp->opcode==OP_And ){

  86084.     static const unsigned char and_logic[] = { 0, 0, 0, 0, 1, 2, 0, 2, 2 };

  86085.     v1 = and_logic[v1*3+v2];

  86086.   }else{

  86087.     static const unsigned char or_logic[] = { 0, 1, 2, 1, 1, 1, 2, 1, 2 };

  86088.     v1 = or_logic[v1*3+v2];

  86089.   }

  86090.   pOut = &aMem[pOp->p3];

  86091.   if( v1==2 ){

  86092.     MemSetTypeFlag(pOut, MEM_Null);

  86093.   }else{

  86094.     pOut->u.i = v1;

  86095.     MemSetTypeFlag(pOut, MEM_Int);

  86096.   }

  86097.   break;

  86098. }

  86099. 

  86100. /* Opcode: IsTrue P1 P2 P3 P4 *

  86101. ** Synopsis: r[P2] = coalesce(r[P1]==TRUE,P3) ^ P4

  86102. **

  86103. ** This opcode implements the IS TRUE, IS FALSE, IS NOT TRUE, and

  86104. ** IS NOT FALSE operators.

  86105. **

  86106. ** Interpret the value in register P1 as a boolean value.  Store that

  86107. ** boolean (a 0 or 1) in register P2.  Or if the value in register P1 is 

  86108. ** NULL, then the P3 is stored in register P2.  Invert the answer if P4

  86109. ** is 1.

  86110. **

  86111. ** The logic is summarized like this:

  86112. **

  86113. ** <ul> 

  86114. ** <li> If P3==0 and P4==0  then  r[P2] := r[P1] IS TRUE

  86115. ** <li> If P3==1 and P4==1  then  r[P2] := r[P1] IS FALSE

  86116. ** <li> If P3==0 and P4==1  then  r[P2] := r[P1] IS NOT TRUE

  86117. ** <li> If P3==1 and P4==0  then  r[P2] := r[P1] IS NOT FALSE

  86118. ** </ul>

  86119. */

  86120. case OP_IsTrue: {               /* in1, out2 */

  86121.   assert( pOp->p4type==P4_INT32 );

  86122.   assert( pOp->p4.i==0 || pOp->p4.i==1 );

  86123.   assert( pOp->p3==0 || pOp->p3==1 );

  86124.   sqlite3VdbeMemSetInt64(&aMem[pOp->p2],

  86125.       sqlite3VdbeBooleanValue(&aMem[pOp->p1], pOp->p3) ^ pOp->p4.i);

  86126.   break;

  86127. }

  86128. 

  86129. /* Opcode: Not P1 P2 * * *

  86130. ** Synopsis: r[P2]= !r[P1]

  86131. **

  86132. ** Interpret the value in register P1 as a boolean value.  Store the

  86133. ** boolean complement in register P2.  If the value in register P1 is 

  86134. ** NULL, then a NULL is stored in P2.

  86135. */

  86136. case OP_Not: {                /* same as TK_NOT, in1, out2 */

  86137.   pIn1 = &aMem[pOp->p1];

  86138.   pOut = &aMem[pOp->p2];

  86139.   if( (pIn1->flags & MEM_Null)==0 ){

  86140.     sqlite3VdbeMemSetInt64(pOut, !sqlite3VdbeBooleanValue(pIn1,0));

  86141.   }else{

  86142.     sqlite3VdbeMemSetNull(pOut);

  86143.   }

  86144.   break;

  86145. }

  86146. 

  86147. /* Opcode: BitNot P1 P2 * * *

  86148. ** Synopsis: r[P2]= ~r[P1]

  86149. **

  86150. ** Interpret the content of register P1 as an integer.  Store the

  86151. ** ones-complement of the P1 value into register P2.  If P1 holds

  86152. ** a NULL then store a NULL in P2.

  86153. */

  86154. case OP_BitNot: {             /* same as TK_BITNOT, in1, out2 */

  86155.   pIn1 = &aMem[pOp->p1];

  86156.   pOut = &aMem[pOp->p2];

  86157.   sqlite3VdbeMemSetNull(pOut);

  86158.   if( (pIn1->flags & MEM_Null)==0 ){

  86159.     pOut->flags = MEM_Int;

  86160.     pOut->u.i = ~sqlite3VdbeIntValue(pIn1);

  86161.   }

  86162.   break;

  86163. }

  86164. 

  86165. /* Opcode: Once P1 P2 * * *

  86166. **

  86167. ** Fall through to the next instruction the first time this opcode is

  86168. ** encountered on each invocation of the byte-code program.  Jump to P2

  86169. ** on the second and all subsequent encounters during the same invocation.

  86170. **

  86171. ** Top-level programs determine first invocation by comparing the P1

  86172. ** operand against the P1 operand on the OP_Init opcode at the beginning

  86173. ** of the program.  If the P1 values differ, then fall through and make

  86174. ** the P1 of this opcode equal to the P1 of OP_Init.  If P1 values are

  86175. ** the same then take the jump.

  86176. **

  86177. ** For subprograms, there is a bitmask in the VdbeFrame that determines

  86178. ** whether or not the jump should be taken.  The bitmask is necessary

  86179. ** because the self-altering code trick does not work for recursive

  86180. ** triggers.

  86181. */

  86182. case OP_Once: {             /* jump */

  86183.   u32 iAddr;                /* Address of this instruction */

  86184.   assert( p->aOp[0].opcode==OP_Init );

  86185.   if( p->pFrame ){

  86186.     iAddr = (int)(pOp - p->aOp);

  86187.     if( (p->pFrame->aOnce[iAddr/8] & (1<<(iAddr & 7)))!=0 ){

  86188.       VdbeBranchTaken(1, 2);

  86189.       goto jump_to_p2;

  86190.     }

  86191.     p->pFrame->aOnce[iAddr/8] |= 1<<(iAddr & 7);

  86192.   }else{

  86193.     if( p->aOp[0].p1==pOp->p1 ){

  86194.       VdbeBranchTaken(1, 2);

  86195.       goto jump_to_p2;

  86196.     }

  86197.   }

  86198.   VdbeBranchTaken(0, 2);

  86199.   pOp->p1 = p->aOp[0].p1;

  86200.   break;

  86201. }

  86202. 

  86203. /* Opcode: If P1 P2 P3 * *

  86204. **

  86205. ** Jump to P2 if the value in register P1 is true.  The value

  86206. ** is considered true if it is numeric and non-zero.  If the value

  86207. ** in P1 is NULL then take the jump if and only if P3 is non-zero.

  86208. */

  86209. case OP_If:  {               /* jump, in1 */

  86210.   int c;

  86211.   c = sqlite3VdbeBooleanValue(&aMem[pOp->p1], pOp->p3);

  86212.   VdbeBranchTaken(c!=0, 2);

  86213.   if( c ) goto jump_to_p2;

  86214.   break;

  86215. }

  86216. 

  86217. /* Opcode: IfNot P1 P2 P3 * *

  86218. **

  86219. ** Jump to P2 if the value in register P1 is False.  The value

  86220. ** is considered false if it has a numeric value of zero.  If the value

  86221. ** in P1 is NULL then take the jump if and only if P3 is non-zero.

  86222. */

  86223. case OP_IfNot: {            /* jump, in1 */

  86224.   int c;

  86225.   c = !sqlite3VdbeBooleanValue(&aMem[pOp->p1], !pOp->p3);

  86226.   VdbeBranchTaken(c!=0, 2);

  86227.   if( c ) goto jump_to_p2;

  86228.   break;

  86229. }

  86230. 

  86231. /* Opcode: IsNull P1 P2 * * *

  86232. ** Synopsis: if r[P1]==NULL goto P2

  86233. **

  86234. ** Jump to P2 if the value in register P1 is NULL.

  86235. */

  86236. case OP_IsNull: {            /* same as TK_ISNULL, jump, in1 */

  86237.   pIn1 = &aMem[pOp->p1];

  86238.   VdbeBranchTaken( (pIn1->flags & MEM_Null)!=0, 2);

  86239.   if( (pIn1->flags & MEM_Null)!=0 ){

  86240.     goto jump_to_p2;

  86241.   }

  86242.   break;

  86243. }

  86244. 

  86245. /* Opcode: NotNull P1 P2 * * *

  86246. ** Synopsis: if r[P1]!=NULL goto P2

  86247. **

  86248. ** Jump to P2 if the value in register P1 is not NULL.  

  86249. */

  86250. case OP_NotNull: {            /* same as TK_NOTNULL, jump, in1 */

  86251.   pIn1 = &aMem[pOp->p1];

  86252.   VdbeBranchTaken( (pIn1->flags & MEM_Null)==0, 2);

  86253.   if( (pIn1->flags & MEM_Null)==0 ){

  86254.     goto jump_to_p2;

  86255.   }

  86256.   break;

  86257. }

  86258. 

  86259. /* Opcode: IfNullRow P1 P2 P3 * *

  86260. ** Synopsis: if P1.nullRow then r[P3]=NULL, goto P2

  86261. **

  86262. ** Check the cursor P1 to see if it is currently pointing at a NULL row.

  86263. ** If it is, then set register P3 to NULL and jump immediately to P2.

  86264. ** If P1 is not on a NULL row, then fall through without making any

  86265. ** changes.

  86266. */

  86267. case OP_IfNullRow: {         /* jump */

  86268.   assert( pOp->p1>=0 && pOp->p1<p->nCursor );

  86269.   assert( p->apCsr[pOp->p1]!=0 );

  86270.   if( p->apCsr[pOp->p1]->nullRow ){

  86271.     sqlite3VdbeMemSetNull(aMem + pOp->p3);

  86272.     goto jump_to_p2;

  86273.   }

  86274.   break;

  86275. }

  86276. 

  86277. #ifdef SQLITE_ENABLE_OFFSET_SQL_FUNC

  86278. /* Opcode: Offset P1 P2 P3 * *

  86279. ** Synopsis: r[P3] = sqlite_offset(P1)

  86280. **

  86281. ** Store in register r[P3] the byte offset into the database file that is the

  86282. ** start of the payload for the record at which that cursor P1 is currently

  86283. ** pointing.

  86284. **

  86285. ** P2 is the column number for the argument to the sqlite_offset() function.

  86286. ** This opcode does not use P2 itself, but the P2 value is used by the

  86287. ** code generator.  The P1, P2, and P3 operands to this opcode are the

  86288. ** same as for OP_Column.

  86289. **

  86290. ** This opcode is only available if SQLite is compiled with the

  86291. ** -DSQLITE_ENABLE_OFFSET_SQL_FUNC option.

  86292. */

  86293. case OP_Offset: {          /* out3 */

  86294.   VdbeCursor *pC;    /* The VDBE cursor */

  86295.   assert( pOp->p1>=0 && pOp->p1<p->nCursor );

  86296.   pC = p->apCsr[pOp->p1];

  86297.   pOut = &p->aMem[pOp->p3];

  86298.   if( NEVER(pC==0) || pC->eCurType!=CURTYPE_BTREE ){

  86299.     sqlite3VdbeMemSetNull(pOut);

  86300.   }else{

  86301.     sqlite3VdbeMemSetInt64(pOut, sqlite3BtreeOffset(pC->uc.pCursor));

  86302.   }

  86303.   break;

  86304. }

  86305. #endif /* SQLITE_ENABLE_OFFSET_SQL_FUNC */

  86306. 

  86307. /* Opcode: Column P1 P2 P3 P4 P5

  86308. ** Synopsis: r[P3]=PX

  86309. **

  86310. ** Interpret the data that cursor P1 points to as a structure built using

  86311. ** the MakeRecord instruction.  (See the MakeRecord opcode for additional

  86312. ** information about the format of the data.)  Extract the P2-th column

  86313. ** from this record.  If there are less that (P2+1) 

  86314. ** values in the record, extract a NULL.

  86315. **

  86316. ** The value extracted is stored in register P3.

  86317. **

  86318. ** If the record contains fewer than P2 fields, then extract a NULL.  Or,

  86319. ** if the P4 argument is a P4_MEM use the value of the P4 argument as

  86320. ** the result.

  86321. **

  86322. ** If the OPFLAG_CLEARCACHE bit is set on P5 and P1 is a pseudo-table cursor,

  86323. ** then the cache of the cursor is reset prior to extracting the column.

  86324. ** The first OP_Column against a pseudo-table after the value of the content

  86325. ** register has changed should have this bit set.

  86326. **

  86327. ** If the OPFLAG_LENGTHARG and OPFLAG_TYPEOFARG bits are set on P5 then

  86328. ** the result is guaranteed to only be used as the argument of a length()

  86329. ** or typeof() function, respectively.  The loading of large blobs can be

  86330. ** skipped for length() and all content loading can be skipped for typeof().

  86331. */

  86332. case OP_Column: {

  86333.   int p2;            /* column number to retrieve */

  86334.   VdbeCursor *pC;    /* The VDBE cursor */

  86335.   BtCursor *pCrsr;   /* The BTree cursor */

  86336.   u32 *aOffset;      /* aOffset[i] is offset to start of data for i-th column */

  86337.   int len;           /* The length of the serialized data for the column */

  86338.   int i;             /* Loop counter */

  86339.   Mem *pDest;        /* Where to write the extracted value */

  86340.   Mem sMem;          /* For storing the record being decoded */

  86341.   const u8 *zData;   /* Part of the record being decoded */

  86342.   const u8 *zHdr;    /* Next unparsed byte of the header */

  86343.   const u8 *zEndHdr; /* Pointer to first byte after the header */

  86344.   u64 offset64;      /* 64-bit offset */

  86345.   u32 t;             /* A type code from the record header */

  86346.   Mem *pReg;         /* PseudoTable input register */

  86347. 

  86348.   pC = p->apCsr[pOp->p1];

  86349.   p2 = pOp->p2;

  86350. 

  86351.   /* If the cursor cache is stale (meaning it is not currently point at

  86352.   ** the correct row) then bring it up-to-date by doing the necessary 

  86353.   ** B-Tree seek. */

  86354.   rc = sqlite3VdbeCursorMoveto(&pC, &p2);

  86355.   if( rc ) goto abort_due_to_error;

  86356. 

  86357.   assert( pOp->p3>0 && pOp->p3<=(p->nMem+1 - p->nCursor) );

  86358.   pDest = &aMem[pOp->p3];

  86359.   memAboutToChange(p, pDest);

  86360.   assert( pOp->p1>=0 && pOp->p1<p->nCursor );

  86361.   assert( pC!=0 );

  86362.   assert( p2<pC->nField );

  86363.   aOffset = pC->aOffset;

  86364.   assert( pC->eCurType!=CURTYPE_VTAB );

  86365.   assert( pC->eCurType!=CURTYPE_PSEUDO || pC->nullRow );

  86366.   assert( pC->eCurType!=CURTYPE_SORTER );

  86367. 

  86368.   if( pC->cacheStatus!=p->cacheCtr ){                /*OPTIMIZATION-IF-FALSE*/

  86369.     if( pC->nullRow ){

  86370.       if( pC->eCurType==CURTYPE_PSEUDO ){

  86371.         /* For the special case of as pseudo-cursor, the seekResult field

  86372.         ** identifies the register that holds the record */

  86373.         assert( pC->seekResult>0 );

  86374.         pReg = &aMem[pC->seekResult];

  86375.         assert( pReg->flags & MEM_Blob );

  86376.         assert( memIsValid(pReg) );

  86377.         pC->payloadSize = pC->szRow = pReg->n;

  86378.         pC->aRow = (u8*)pReg->z;

  86379.       }else{

  86380.         sqlite3VdbeMemSetNull(pDest);

  86381.         goto op_column_out;

  86382.       }

  86383.     }else{

  86384.       pCrsr = pC->uc.pCursor;

  86385.       assert( pC->eCurType==CURTYPE_BTREE );

  86386.       assert( pCrsr );

  86387.       assert( sqlite3BtreeCursorIsValid(pCrsr) );

  86388.       pC->payloadSize = sqlite3BtreePayloadSize(pCrsr);

  86389.       pC->aRow = sqlite3BtreePayloadFetch(pCrsr, &pC->szRow);

  86390.       assert( pC->szRow<=pC->payloadSize );

  86391.       assert( pC->szRow<=65536 );  /* Maximum page size is 64KiB */

  86392.       if( pC->payloadSize > (u32)db->aLimit[SQLITE_LIMIT_LENGTH] ){

  86393.         goto too_big;

  86394.       }

  86395.     }

  86396.     pC->cacheStatus = p->cacheCtr;

  86397.     pC->iHdrOffset = getVarint32(pC->aRow, aOffset[0]);

  86398.     pC->nHdrParsed = 0;

  86399. 

  86400. 

  86401.     if( pC->szRow<aOffset[0] ){      /*OPTIMIZATION-IF-FALSE*/

  86402.       /* pC->aRow does not have to hold the entire row, but it does at least

  86403.       ** need to cover the header of the record.  If pC->aRow does not contain

  86404.       ** the complete header, then set it to zero, forcing the header to be

  86405.       ** dynamically allocated. */

  86406.       pC->aRow = 0;

  86407.       pC->szRow = 0;

  86408. 

  86409.       /* Make sure a corrupt database has not given us an oversize header.

  86410.       ** Do this now to avoid an oversize memory allocation.

  86411.       **

  86412.       ** Type entries can be between 1 and 5 bytes each.  But 4 and 5 byte

  86413.       ** types use so much data space that there can only be 4096 and 32 of

  86414.       ** them, respectively.  So the maximum header length results from a

  86415.       ** 3-byte type for each of the maximum of 32768 columns plus three

  86416.       ** extra bytes for the header length itself.  32768*3 + 3 = 98307.

  86417.       */

  86418.       if( aOffset[0] > 98307 || aOffset[0] > pC->payloadSize ){

  86419.         goto op_column_corrupt;

  86420.       }

  86421.     }else{

  86422.       /* This is an optimization.  By skipping over the first few tests

  86423.       ** (ex: pC->nHdrParsed<=p2) in the next section, we achieve a

  86424.       ** measurable performance gain.

  86425.       **

  86426.       ** This branch is taken even if aOffset[0]==0.  Such a record is never

  86427.       ** generated by SQLite, and could be considered corruption, but we

  86428.       ** accept it for historical reasons.  When aOffset[0]==0, the code this

  86429.       ** branch jumps to reads past the end of the record, but never more

  86430.       ** than a few bytes.  Even if the record occurs at the end of the page

  86431.       ** content area, the "page header" comes after the page content and so

  86432.       ** this overread is harmless.  Similar overreads can occur for a corrupt

  86433.       ** database file.

  86434.       */

  86435.       zData = pC->aRow;

  86436.       assert( pC->nHdrParsed<=p2 );         /* Conditional skipped */

  86437.       testcase( aOffset[0]==0 );

  86438.       goto op_column_read_header;

  86439.     }

  86440.   }

  86441. 

  86442.   /* Make sure at least the first p2+1 entries of the header have been

  86443.   ** parsed and valid information is in aOffset[] and pC->aType[].

  86444.   */

  86445.   if( pC->nHdrParsed<=p2 ){

  86446.     /* If there is more header available for parsing in the record, try

  86447.     ** to extract additional fields up through the p2+1-th field 

  86448.     */

  86449.     if( pC->iHdrOffset<aOffset[0] ){

  86450.       /* Make sure zData points to enough of the record to cover the header. */

  86451.       if( pC->aRow==0 ){

  86452.         memset(&sMem, 0, sizeof(sMem));

  86453.         rc = sqlite3VdbeMemFromBtree(pC->uc.pCursor, 0, aOffset[0], &sMem);

  86454.         if( rc!=SQLITE_OK ) goto abort_due_to_error;

  86455.         zData = (u8*)sMem.z;

  86456.       }else{

  86457.         zData = pC->aRow;

  86458.       }

  86459.   

  86460.       /* Fill in pC->aType[i] and aOffset[i] values through the p2-th field. */

  86461.     op_column_read_header:

  86462.       i = pC->nHdrParsed;

  86463.       offset64 = aOffset[i];

  86464.       zHdr = zData + pC->iHdrOffset;

  86465.       zEndHdr = zData + aOffset[0];

  86466.       testcase( zHdr>=zEndHdr );

  86467.       do{

  86468.         if( (pC->aType[i] = t = zHdr[0])<0x80 ){

  86469.           zHdr++;

  86470.           offset64 += sqlite3VdbeOneByteSerialTypeLen(t);

  86471.         }else{

  86472.           zHdr += sqlite3GetVarint32(zHdr, &t);

  86473.           pC->aType[i] = t;

  86474.           offset64 += sqlite3VdbeSerialTypeLen(t);

  86475.         }

  86476.         aOffset[++i] = (u32)(offset64 & 0xffffffff);

  86477.       }while( i<=p2 && zHdr<zEndHdr );

  86478. 

  86479.       /* The record is corrupt if any of the following are true:

  86480.       ** (1) the bytes of the header extend past the declared header size

  86481.       ** (2) the entire header was used but not all data was used

  86482.       ** (3) the end of the data extends beyond the end of the record.

  86483.       */

  86484.       if( (zHdr>=zEndHdr && (zHdr>zEndHdr || offset64!=pC->payloadSize))

  86485.        || (offset64 > pC->payloadSize)

  86486.       ){

  86487.         if( aOffset[0]==0 ){

  86488.           i = 0;

  86489.           zHdr = zEndHdr;

  86490.         }else{

  86491.           if( pC->aRow==0 ) sqlite3VdbeMemRelease(&sMem);

  86492.           goto op_column_corrupt;

  86493.         }

  86494.       }

  86495. 

  86496.       pC->nHdrParsed = i;

  86497.       pC->iHdrOffset = (u32)(zHdr - zData);

  86498.       if( pC->aRow==0 ) sqlite3VdbeMemRelease(&sMem);

  86499.     }else{

  86500.       t = 0;

  86501.     }

  86502. 

  86503.     /* If after trying to extract new entries from the header, nHdrParsed is

  86504.     ** still not up to p2, that means that the record has fewer than p2

  86505.     ** columns.  So the result will be either the default value or a NULL.

  86506.     */

  86507.     if( pC->nHdrParsed<=p2 ){

  86508.       if( pOp->p4type==P4_MEM ){

  86509.         sqlite3VdbeMemShallowCopy(pDest, pOp->p4.pMem, MEM_Static);

  86510.       }else{

  86511.         sqlite3VdbeMemSetNull(pDest);

  86512.       }

  86513.       goto op_column_out;

  86514.     }

  86515.   }else{

  86516.     t = pC->aType[p2];

  86517.   }

  86518. 

  86519.   /* Extract the content for the p2+1-th column.  Control can only

  86520.   ** reach this point if aOffset[p2], aOffset[p2+1], and pC->aType[p2] are

  86521.   ** all valid.

  86522.   */

  86523.   assert( p2<pC->nHdrParsed );

  86524.   assert( rc==SQLITE_OK );

  86525.   assert( sqlite3VdbeCheckMemInvariants(pDest) );

  86526.   if( VdbeMemDynamic(pDest) ){

  86527.     sqlite3VdbeMemSetNull(pDest);

  86528.   }

  86529.   assert( t==pC->aType[p2] );

  86530.   if( pC->szRow>=aOffset[p2+1] ){

  86531.     /* This is the common case where the desired content fits on the original

  86532.     ** page - where the content is not on an overflow page */

  86533.     zData = pC->aRow + aOffset[p2];

  86534.     if( t<12 ){

  86535.       sqlite3VdbeSerialGet(zData, t, pDest);

  86536.     }else{

  86537.       /* If the column value is a string, we need a persistent value, not

  86538.       ** a MEM_Ephem value.  This branch is a fast short-cut that is equivalent

  86539.       ** to calling sqlite3VdbeSerialGet() and sqlite3VdbeDeephemeralize().

  86540.       */

  86541.       static const u16 aFlag[] = { MEM_Blob, MEM_Str|MEM_Term };

  86542.       pDest->n = len = (t-12)/2;

  86543.       pDest->enc = encoding;

  86544.       if( pDest->szMalloc < len+2 ){

  86545.         pDest->flags = MEM_Null;

  86546.         if( sqlite3VdbeMemGrow(pDest, len+2, 0) ) goto no_mem;

  86547.       }else{

  86548.         pDest->z = pDest->zMalloc;

  86549.       }

  86550.       memcpy(pDest->z, zData, len);

  86551.       pDest->z[len] = 0;

  86552.       pDest->z[len+1] = 0;

  86553.       pDest->flags = aFlag[t&1];

  86554.     }

  86555.   }else{

  86556.     pDest->enc = encoding;

  86557.     /* This branch happens only when content is on overflow pages */

  86558.     if( ((pOp->p5 & (OPFLAG_LENGTHARG|OPFLAG_TYPEOFARG))!=0

  86559.           && ((t>=12 && (t&1)==0) || (pOp->p5 & OPFLAG_TYPEOFARG)!=0))

  86560.      || (len = sqlite3VdbeSerialTypeLen(t))==0

  86561.     ){

  86562.       /* Content is irrelevant for

  86563.       **    1. the typeof() function,

  86564.       **    2. the length(X) function if X is a blob, and

  86565.       **    3. if the content length is zero.

  86566.       ** So we might as well use bogus content rather than reading

  86567.       ** content from disk. 

  86568.       **

  86569.       ** Although sqlite3VdbeSerialGet() may read at most 8 bytes from the

  86570.       ** buffer passed to it, debugging function VdbeMemPrettyPrint() may

  86571.       ** read up to 16. So 16 bytes of bogus content is supplied.

  86572.       */

  86573.       static u8 aZero[16];  /* This is the bogus content */

  86574.       sqlite3VdbeSerialGet(aZero, t, pDest);

  86575.     }else{

  86576.       rc = sqlite3VdbeMemFromBtree(pC->uc.pCursor, aOffset[p2], len, pDest);

  86577.       if( rc!=SQLITE_OK ) goto abort_due_to_error;

  86578.       sqlite3VdbeSerialGet((const u8*)pDest->z, t, pDest);

  86579.       pDest->flags &= ~MEM_Ephem;

  86580.     }

  86581.   }

  86582. 

  86583. op_column_out:

  86584.   UPDATE_MAX_BLOBSIZE(pDest);

  86585.   REGISTER_TRACE(pOp->p3, pDest);

  86586.   break;

  86587. 

  86588. op_column_corrupt:

  86589.   if( aOp[0].p3>0 ){

  86590.     pOp = &aOp[aOp[0].p3-1];

  86591.     break;

  86592.   }else{

  86593.     rc = SQLITE_CORRUPT_BKPT;

  86594.     goto abort_due_to_error;

  86595.   }

  86596. }

  86597. 

  86598. /* Opcode: Affinity P1 P2 * P4 *

  86599. ** Synopsis: affinity(r[P1@P2])

  86600. **

  86601. ** Apply affinities to a range of P2 registers starting with P1.

  86602. **

  86603. ** P4 is a string that is P2 characters long. The N-th character of the

  86604. ** string indicates the column affinity that should be used for the N-th

  86605. ** memory cell in the range.

  86606. */

  86607. case OP_Affinity: {

  86608.   const char *zAffinity;   /* The affinity to be applied */

  86609. 

  86610.   zAffinity = pOp->p4.z;

  86611.   assert( zAffinity!=0 );

  86612.   assert( pOp->p2>0 );

  86613.   assert( zAffinity[pOp->p2]==0 );

  86614.   pIn1 = &aMem[pOp->p1];

  86615.   while( 1 /*edit-by-break*/ ){

  86616.     assert( pIn1 <= &p->aMem[(p->nMem+1 - p->nCursor)] );

  86617.     assert( memIsValid(pIn1) );

  86618.     applyAffinity(pIn1, zAffinity[0], encoding);

  86619.     if( zAffinity[0]==SQLITE_AFF_REAL && (pIn1->flags & MEM_Int)!=0 ){

  86620.       /* When applying REAL affinity, if the result is still MEM_Int, 

  86621.       ** indicate that REAL is actually desired */

  86622.       pIn1->flags |= MEM_IntReal;

  86623.       pIn1->flags &= ~MEM_Int;

  86624.     }

  86625.     REGISTER_TRACE((int)(pIn1-aMem), pIn1);

  86626.     zAffinity++;

  86627.     if( zAffinity[0]==0 ) break;

  86628.     pIn1++;

  86629.   }

  86630.   break;

  86631. }

  86632. 

  86633. /* Opcode: MakeRecord P1 P2 P3 P4 *

  86634. ** Synopsis: r[P3]=mkrec(r[P1@P2])

  86635. **

  86636. ** Convert P2 registers beginning with P1 into the [record format]

  86637. ** use as a data record in a database table or as a key

  86638. ** in an index.  The OP_Column opcode can decode the record later.

  86639. **

  86640. ** P4 may be a string that is P2 characters long.  The N-th character of the

  86641. ** string indicates the column affinity that should be used for the N-th

  86642. ** field of the index key.

  86643. **

  86644. ** The mapping from character to affinity is given by the SQLITE_AFF_

  86645. ** macros defined in sqliteInt.h.

  86646. **

  86647. ** If P4 is NULL then all index fields have the affinity BLOB.

  86648. */

  86649. case OP_MakeRecord: {

  86650.   Mem *pRec;             /* The new record */

  86651.   u64 nData;             /* Number of bytes of data space */

  86652.   int nHdr;              /* Number of bytes of header space */

  86653.   i64 nByte;             /* Data space required for this record */

  86654.   i64 nZero;             /* Number of zero bytes at the end of the record */

  86655.   int nVarint;           /* Number of bytes in a varint */

  86656.   u32 serial_type;       /* Type field */

  86657.   Mem *pData0;           /* First field to be combined into the record */

  86658.   Mem *pLast;            /* Last field of the record */

  86659.   int nField;            /* Number of fields in the record */

  86660.   char *zAffinity;       /* The affinity string for the record */

  86661.   int file_format;       /* File format to use for encoding */

  86662.   u32 len;               /* Length of a field */

  86663.   u8 *zHdr;              /* Where to write next byte of the header */

  86664.   u8 *zPayload;          /* Where to write next byte of the payload */

  86665. 

  86666.   /* Assuming the record contains N fields, the record format looks

  86667.   ** like this:

  86668.   **

  86669.   ** ------------------------------------------------------------------------

  86670.   ** | hdr-size | type 0 | type 1 | ... | type N-1 | data0 | ... | data N-1 | 

  86671.   ** ------------------------------------------------------------------------

  86672.   **

  86673.   ** Data(0) is taken from register P1.  Data(1) comes from register P1+1

  86674.   ** and so forth.

  86675.   **

  86676.   ** Each type field is a varint representing the serial type of the 

  86677.   ** corresponding data element (see sqlite3VdbeSerialType()). The

  86678.   ** hdr-size field is also a varint which is the offset from the beginning

  86679.   ** of the record to data0.

  86680.   */

  86681.   nData = 0;         /* Number of bytes of data space */

  86682.   nHdr = 0;          /* Number of bytes of header space */

  86683.   nZero = 0;         /* Number of zero bytes at the end of the record */

  86684.   nField = pOp->p1;

  86685.   zAffinity = pOp->p4.z;

  86686.   assert( nField>0 && pOp->p2>0 && pOp->p2+nField<=(p->nMem+1 - p->nCursor)+1 );

  86687.   pData0 = &aMem[nField];

  86688.   nField = pOp->p2;

  86689.   pLast = &pData0[nField-1];

  86690.   file_format = p->minWriteFileFormat;

  86691. 

  86692.   /* Identify the output register */

  86693.   assert( pOp->p3<pOp->p1 || pOp->p3>=pOp->p1+pOp->p2 );

  86694.   pOut = &aMem[pOp->p3];

  86695.   memAboutToChange(p, pOut);

  86696. 

  86697.   /* Apply the requested affinity to all inputs

  86698.   */

  86699.   assert( pData0<=pLast );

  86700.   if( zAffinity ){

  86701.     pRec = pData0;

  86702.     do{

  86703.       applyAffinity(pRec, zAffinity[0], encoding);

  86704.       if( zAffinity[0]==SQLITE_AFF_REAL && (pRec->flags & MEM_Int) ){

  86705.         pRec->flags |= MEM_IntReal;

  86706.         pRec->flags &= ~(MEM_Int);

  86707.       }

  86708.       REGISTER_TRACE((int)(pRec-aMem), pRec);

  86709.       zAffinity++;

  86710.       pRec++;

  86711.       assert( zAffinity[0]==0 || pRec<=pLast );

  86712.     }while( zAffinity[0] );

  86713.   }

  86714. 

  86715. #ifdef SQLITE_ENABLE_NULL_TRIM

  86716.   /* NULLs can be safely trimmed from the end of the record, as long as

  86717.   ** as the schema format is 2 or more and none of the omitted columns

  86718.   ** have a non-NULL default value.  Also, the record must be left with

  86719.   ** at least one field.  If P5>0 then it will be one more than the

  86720.   ** index of the right-most column with a non-NULL default value */

  86721.   if( pOp->p5 ){

  86722.     while( (pLast->flags & MEM_Null)!=0 && nField>pOp->p5 ){

  86723.       pLast--;

  86724.       nField--;

  86725.     }

  86726.   }

  86727. #endif

  86728. 

  86729.   /* Loop through the elements that will make up the record to figure

  86730.   ** out how much space is required for the new record.

  86731.   */

  86732.   pRec = pLast;

  86733.   do{

  86734.     assert( memIsValid(pRec) );

  86735.     serial_type = sqlite3VdbeSerialType(pRec, file_format, &len);

  86736.     if( pRec->flags & MEM_Zero ){

  86737.       if( serial_type==0 ){

  86738.         /* Values with MEM_Null and MEM_Zero are created by xColumn virtual

  86739.         ** table methods that never invoke sqlite3_result_xxxxx() while

  86740.         ** computing an unchanging column value in an UPDATE statement.

  86741.         ** Give such values a special internal-use-only serial-type of 10

  86742.         ** so that they can be passed through to xUpdate and have

  86743.         ** a true sqlite3_value_nochange(). */

  86744.         assert( pOp->p5==OPFLAG_NOCHNG_MAGIC || CORRUPT_DB );

  86745.         serial_type = 10;

  86746.       }else if( nData ){

  86747.         if( sqlite3VdbeMemExpandBlob(pRec) ) goto no_mem;

  86748.       }else{

  86749.         nZero += pRec->u.nZero;

  86750.         len -= pRec->u.nZero;

  86751.       }

  86752.     }

  86753.     nData += len;

  86754.     testcase( serial_type==127 );

  86755.     testcase( serial_type==128 );

  86756.     nHdr += serial_type<=127 ? 1 : sqlite3VarintLen(serial_type);

  86757.     pRec->uTemp = serial_type;

  86758.     if( pRec==pData0 ) break;

  86759.     pRec--;

  86760.   }while(1);

  86761. 

  86762.   /* EVIDENCE-OF: R-22564-11647 The header begins with a single varint

  86763.   ** which determines the total number of bytes in the header. The varint

  86764.   ** value is the size of the header in bytes including the size varint

  86765.   ** itself. */

  86766.   testcase( nHdr==126 );

  86767.   testcase( nHdr==127 );

  86768.   if( nHdr<=126 ){

  86769.     /* The common case */

  86770.     nHdr += 1;

  86771.   }else{

  86772.     /* Rare case of a really large header */

  86773.     nVarint = sqlite3VarintLen(nHdr);

  86774.     nHdr += nVarint;

  86775.     if( nVarint<sqlite3VarintLen(nHdr) ) nHdr++;

  86776.   }

  86777.   nByte = nHdr+nData;

  86778. 

  86779.   /* Make sure the output register has a buffer large enough to store 

  86780.   ** the new record. The output register (pOp->p3) is not allowed to

  86781.   ** be one of the input registers (because the following call to

  86782.   ** sqlite3VdbeMemClearAndResize() could clobber the value before it is used).

  86783.   */

  86784.   if( nByte+nZero<=pOut->szMalloc ){

  86785.     /* The output register is already large enough to hold the record.

  86786.     ** No error checks or buffer enlargement is required */

  86787.     pOut->z = pOut->zMalloc;

  86788.   }else{

  86789.     /* Need to make sure that the output is not too big and then enlarge

  86790.     ** the output register to hold the full result */

  86791.     if( nByte+nZero>db->aLimit[SQLITE_LIMIT_LENGTH] ){

  86792.       goto too_big;

  86793.     }

  86794.     if( sqlite3VdbeMemClearAndResize(pOut, (int)nByte) ){

  86795.       goto no_mem;

  86796.     }

  86797.   }

  86798.   pOut->n = (int)nByte;

  86799.   pOut->flags = MEM_Blob;

  86800.   if( nZero ){

  86801.     pOut->u.nZero = nZero;

  86802.     pOut->flags |= MEM_Zero;

  86803.   }

  86804.   UPDATE_MAX_BLOBSIZE(pOut);

  86805.   zHdr = (u8 *)pOut->z;

  86806.   zPayload = zHdr + nHdr;

  86807. 

  86808.   /* Write the record */

  86809.   zHdr += putVarint32(zHdr, nHdr);

  86810.   assert( pData0<=pLast );

  86811.   pRec = pData0;

  86812.   do{

  86813.     serial_type = pRec->uTemp;

  86814.     /* EVIDENCE-OF: R-06529-47362 Following the size varint are one or more

  86815.     ** additional varints, one per column. */

  86816.     zHdr += putVarint32(zHdr, serial_type);            /* serial type */

  86817.     /* EVIDENCE-OF: R-64536-51728 The values for each column in the record

  86818.     ** immediately follow the header. */

  86819.     zPayload += sqlite3VdbeSerialPut(zPayload, pRec, serial_type); /* content */

  86820.   }while( (++pRec)<=pLast );

  86821.   assert( nHdr==(int)(zHdr - (u8*)pOut->z) );

  86822.   assert( nByte==(int)(zPayload - (u8*)pOut->z) );

  86823. 

  86824.   assert( pOp->p3>0 && pOp->p3<=(p->nMem+1 - p->nCursor) );

  86825.   REGISTER_TRACE(pOp->p3, pOut);

  86826.   break;

  86827. }

  86828. 

  86829. /* Opcode: Count P1 P2 * * *

  86830. ** Synopsis: r[P2]=count()

  86831. **

  86832. ** Store the number of entries (an integer value) in the table or index 

  86833. ** opened by cursor P1 in register P2

  86834. */

  86835. #ifndef SQLITE_OMIT_BTREECOUNT

  86836. case OP_Count: {         /* out2 */

  86837.   i64 nEntry;

  86838.   BtCursor *pCrsr;

  86839. 

  86840.   assert( p->apCsr[pOp->p1]->eCurType==CURTYPE_BTREE );

  86841.   pCrsr = p->apCsr[pOp->p1]->uc.pCursor;

  86842.   assert( pCrsr );

  86843.   nEntry = 0;  /* Not needed.  Only used to silence a warning. */

  86844.   rc = sqlite3BtreeCount(pCrsr, &nEntry);

  86845.   if( rc ) goto abort_due_to_error;

  86846.   pOut = out2Prerelease(p, pOp);

  86847.   pOut->u.i = nEntry;

  86848.   break;

  86849. }

  86850. #endif

  86851. 

  86852. /* Opcode: Savepoint P1 * * P4 *

  86853. **

  86854. ** Open, release or rollback the savepoint named by parameter P4, depending

  86855. ** on the value of P1. To open a new savepoint set P1==0 (SAVEPOINT_BEGIN).

  86856. ** To release (commit) an existing savepoint set P1==1 (SAVEPOINT_RELEASE).

  86857. ** To rollback an existing savepoint set P1==2 (SAVEPOINT_ROLLBACK).

  86858. */

  86859. case OP_Savepoint: {

  86860.   int p1;                         /* Value of P1 operand */

  86861.   char *zName;                    /* Name of savepoint */

  86862.   int nName;

  86863.   Savepoint *pNew;

  86864.   Savepoint *pSavepoint;

  86865.   Savepoint *pTmp;

  86866.   int iSavepoint;

  86867.   int ii;

  86868. 

  86869.   p1 = pOp->p1;

  86870.   zName = pOp->p4.z;

  86871. 

  86872.   /* Assert that the p1 parameter is valid. Also that if there is no open

  86873.   ** transaction, then there cannot be any savepoints. 

  86874.   */

  86875.   assert( db->pSavepoint==0 || db->autoCommit==0 );

  86876.   assert( p1==SAVEPOINT_BEGIN||p1==SAVEPOINT_RELEASE||p1==SAVEPOINT_ROLLBACK );

  86877.   assert( db->pSavepoint || db->isTransactionSavepoint==0 );

  86878.   assert( checkSavepointCount(db) );

  86879.   assert( p->bIsReader );

  86880. 

  86881.   if( p1==SAVEPOINT_BEGIN ){

  86882.     if( db->nVdbeWrite>0 ){

  86883.       /* A new savepoint cannot be created if there are active write 

  86884.       ** statements (i.e. open read/write incremental blob handles).

  86885.       */

  86886.       sqlite3VdbeError(p, "cannot open savepoint - SQL statements in progress");

  86887.       rc = SQLITE_BUSY;

  86888.     }else{

  86889.       nName = sqlite3Strlen30(zName);

  86890. 

  86891. #ifndef SQLITE_OMIT_VIRTUALTABLE

  86892.       /* This call is Ok even if this savepoint is actually a transaction

  86893.       ** savepoint (and therefore should not prompt xSavepoint()) callbacks.

  86894.       ** If this is a transaction savepoint being opened, it is guaranteed

  86895.       ** that the db->aVTrans[] array is empty.  */

  86896.       assert( db->autoCommit==0 || db->nVTrans==0 );

  86897.       rc = sqlite3VtabSavepoint(db, SAVEPOINT_BEGIN,

  86898.                                 db->nStatement+db->nSavepoint);

  86899.       if( rc!=SQLITE_OK ) goto abort_due_to_error;

  86900. #endif

  86901. 

  86902.       /* Create a new savepoint structure. */

  86903.       pNew = sqlite3DbMallocRawNN(db, sizeof(Savepoint)+nName+1);

  86904.       if( pNew ){

  86905.         pNew->zName = (char *)&pNew[1];

  86906.         memcpy(pNew->zName, zName, nName+1);

  86907.     

  86908.         /* If there is no open transaction, then mark this as a special

  86909.         ** "transaction savepoint". */

  86910.         if( db->autoCommit ){

  86911.           db->autoCommit = 0;

  86912.           db->isTransactionSavepoint = 1;

  86913.         }else{

  86914.           db->nSavepoint++;

  86915.         }

  86916. 

  86917.         /* Link the new savepoint into the database handle's list. */

  86918.         pNew->pNext = db->pSavepoint;

  86919.         db->pSavepoint = pNew;

  86920.         pNew->nDeferredCons = db->nDeferredCons;

  86921.         pNew->nDeferredImmCons = db->nDeferredImmCons;

  86922.       }

  86923.     }

  86924.   }else{

  86925.     assert( p1==SAVEPOINT_RELEASE || p1==SAVEPOINT_ROLLBACK );

  86926.     iSavepoint = 0;

  86927. 

  86928.     /* Find the named savepoint. If there is no such savepoint, then an

  86929.     ** an error is returned to the user.  */

  86930.     for(

  86931.       pSavepoint = db->pSavepoint; 

  86932.       pSavepoint && sqlite3StrICmp(pSavepoint->zName, zName);

  86933.       pSavepoint = pSavepoint->pNext

  86934.     ){

  86935.       iSavepoint++;

  86936.     }

  86937.     if( !pSavepoint ){

  86938.       sqlite3VdbeError(p, "no such savepoint: %s", zName);

  86939.       rc = SQLITE_ERROR;

  86940.     }else if( db->nVdbeWrite>0 && p1==SAVEPOINT_RELEASE ){

  86941.       /* It is not possible to release (commit) a savepoint if there are 

  86942.       ** active write statements.

  86943.       */

  86944.       sqlite3VdbeError(p, "cannot release savepoint - "

  86945.                           "SQL statements in progress");

  86946.       rc = SQLITE_BUSY;

  86947.     }else{

  86948. 

  86949.       /* Determine whether or not this is a transaction savepoint. If so,

  86950.       ** and this is a RELEASE command, then the current transaction 

  86951.       ** is committed. 

  86952.       */

  86953.       int isTransaction = pSavepoint->pNext==0 && db->isTransactionSavepoint;

  86954.       if( isTransaction && p1==SAVEPOINT_RELEASE ){

  86955.         if( (rc = sqlite3VdbeCheckFk(p, 1))!=SQLITE_OK ){

  86956.           goto vdbe_return;

  86957.         }

  86958.         db->autoCommit = 1;

  86959.         if( sqlite3VdbeHalt(p)==SQLITE_BUSY ){

  86960.           p->pc = (int)(pOp - aOp);

  86961.           db->autoCommit = 0;

  86962.           p->rc = rc = SQLITE_BUSY;

  86963.           goto vdbe_return;

  86964.         }

  86965.         db->isTransactionSavepoint = 0;

  86966.         rc = p->rc;

  86967.       }else{

  86968.         int isSchemaChange;

  86969.         iSavepoint = db->nSavepoint - iSavepoint - 1;

  86970.         if( p1==SAVEPOINT_ROLLBACK ){

  86971.           isSchemaChange = (db->mDbFlags & DBFLAG_SchemaChange)!=0;

  86972.           for(ii=0; ii<db->nDb; ii++){

  86973.             rc = sqlite3BtreeTripAllCursors(db->aDb[ii].pBt,

  86974.                                        SQLITE_ABORT_ROLLBACK,

  86975.                                        isSchemaChange==0);

  86976.             if( rc!=SQLITE_OK ) goto abort_due_to_error;

  86977.           }

  86978.         }else{

  86979.           assert( p1==SAVEPOINT_RELEASE );

  86980.           isSchemaChange = 0;

  86981.         }

  86982.         for(ii=0; ii<db->nDb; ii++){

  86983.           rc = sqlite3BtreeSavepoint(db->aDb[ii].pBt, p1, iSavepoint);

  86984.           if( rc!=SQLITE_OK ){

  86985.             goto abort_due_to_error;

  86986.           }

  86987.         }

  86988.         if( isSchemaChange ){

  86989.           sqlite3ExpirePreparedStatements(db, 0);

  86990.           sqlite3ResetAllSchemasOfConnection(db);

  86991.           db->mDbFlags |= DBFLAG_SchemaChange;

  86992.         }

  86993.       }

  86994.   

  86995.       /* Regardless of whether this is a RELEASE or ROLLBACK, destroy all 

  86996.       ** savepoints nested inside of the savepoint being operated on. */

  86997.       while( db->pSavepoint!=pSavepoint ){

  86998.         pTmp = db->pSavepoint;

  86999.         db->pSavepoint = pTmp->pNext;

  87000.         sqlite3DbFree(db, pTmp);

  87001.         db->nSavepoint--;

  87002.       }

  87003. 

  87004.       /* If it is a RELEASE, then destroy the savepoint being operated on 

  87005.       ** too. If it is a ROLLBACK TO, then set the number of deferred 

  87006.       ** constraint violations present in the database to the value stored

  87007.       ** when the savepoint was created.  */

  87008.       if( p1==SAVEPOINT_RELEASE ){

  87009.         assert( pSavepoint==db->pSavepoint );

  87010.         db->pSavepoint = pSavepoint->pNext;

  87011.         sqlite3DbFree(db, pSavepoint);

  87012.         if( !isTransaction ){

  87013.           db->nSavepoint--;

  87014.         }

  87015.       }else{

  87016.         assert( p1==SAVEPOINT_ROLLBACK );

  87017.         db->nDeferredCons = pSavepoint->nDeferredCons;

  87018.         db->nDeferredImmCons = pSavepoint->nDeferredImmCons;

  87019.       }

  87020. 

  87021.       if( !isTransaction || p1==SAVEPOINT_ROLLBACK ){

  87022.         rc = sqlite3VtabSavepoint(db, p1, iSavepoint);

  87023.         if( rc!=SQLITE_OK ) goto abort_due_to_error;

  87024.       }

  87025.     }

  87026.   }

  87027.   if( rc ) goto abort_due_to_error;

  87028. 

  87029.   break;

  87030. }

  87031. 

  87032. /* Opcode: AutoCommit P1 P2 * * *

  87033. **

  87034. ** Set the database auto-commit flag to P1 (1 or 0). If P2 is true, roll

  87035. ** back any currently active btree transactions. If there are any active

  87036. ** VMs (apart from this one), then a ROLLBACK fails.  A COMMIT fails if

  87037. ** there are active writing VMs or active VMs that use shared cache.

  87038. **

  87039. ** This instruction causes the VM to halt.

  87040. */

  87041. case OP_AutoCommit: {

  87042.   int desiredAutoCommit;

  87043.   int iRollback;

  87044. 

  87045.   desiredAutoCommit = pOp->p1;

  87046.   iRollback = pOp->p2;

  87047.   assert( desiredAutoCommit==1 || desiredAutoCommit==0 );

  87048.   assert( desiredAutoCommit==1 || iRollback==0 );

  87049.   assert( db->nVdbeActive>0 );  /* At least this one VM is active */

  87050.   assert( p->bIsReader );

  87051. 

  87052.   if( desiredAutoCommit!=db->autoCommit ){

  87053.     if( iRollback ){

  87054.       assert( desiredAutoCommit==1 );

  87055.       sqlite3RollbackAll(db, SQLITE_ABORT_ROLLBACK);

  87056.       db->autoCommit = 1;

  87057.     }else if( desiredAutoCommit && db->nVdbeWrite>0 ){

  87058.       /* If this instruction implements a COMMIT and other VMs are writing

  87059.       ** return an error indicating that the other VMs must complete first. 

  87060.       */

  87061.       sqlite3VdbeError(p, "cannot commit transaction - "

  87062.                           "SQL statements in progress");

  87063.       rc = SQLITE_BUSY;

  87064.       goto abort_due_to_error;

  87065.     }else if( (rc = sqlite3VdbeCheckFk(p, 1))!=SQLITE_OK ){

  87066.       goto vdbe_return;

  87067.     }else{

  87068.       db->autoCommit = (u8)desiredAutoCommit;

  87069.     }

  87070.     if( sqlite3VdbeHalt(p)==SQLITE_BUSY ){

  87071.       p->pc = (int)(pOp - aOp);

  87072.       db->autoCommit = (u8)(1-desiredAutoCommit);

  87073.       p->rc = rc = SQLITE_BUSY;

  87074.       goto vdbe_return;

  87075.     }

  87076.     assert( db->nStatement==0 );

  87077.     sqlite3CloseSavepoints(db);

  87078.     if( p->rc==SQLITE_OK ){

  87079.       rc = SQLITE_DONE;

  87080.     }else{

  87081.       rc = SQLITE_ERROR;

  87082.     }

  87083.     goto vdbe_return;

  87084.   }else{

  87085.     sqlite3VdbeError(p,

  87086.         (!desiredAutoCommit)?"cannot start a transaction within a transaction":(

  87087.         (iRollback)?"cannot rollback - no transaction is active":

  87088.                    "cannot commit - no transaction is active"));

  87089.          

  87090.     rc = SQLITE_ERROR;

  87091.     goto abort_due_to_error;

  87092.   }

  87093.   break;

  87094. }

  87095. 

  87096. /* Opcode: Transaction P1 P2 P3 P4 P5

  87097. **

  87098. ** Begin a transaction on database P1 if a transaction is not already

  87099. ** active.

  87100. ** If P2 is non-zero, then a write-transaction is started, or if a 

  87101. ** read-transaction is already active, it is upgraded to a write-transaction.

  87102. ** If P2 is zero, then a read-transaction is started.

  87103. **

  87104. ** P1 is the index of the database file on which the transaction is

  87105. ** started.  Index 0 is the main database file and index 1 is the

  87106. ** file used for temporary tables.  Indices of 2 or more are used for

  87107. ** attached databases.

  87108. **

  87109. ** If a write-transaction is started and the Vdbe.usesStmtJournal flag is

  87110. ** true (this flag is set if the Vdbe may modify more than one row and may

  87111. ** throw an ABORT exception), a statement transaction may also be opened.

  87112. ** More specifically, a statement transaction is opened iff the database

  87113. ** connection is currently not in autocommit mode, or if there are other

  87114. ** active statements. A statement transaction allows the changes made by this

  87115. ** VDBE to be rolled back after an error without having to roll back the

  87116. ** entire transaction. If no error is encountered, the statement transaction

  87117. ** will automatically commit when the VDBE halts.

  87118. **

  87119. ** If P5!=0 then this opcode also checks the schema cookie against P3

  87120. ** and the schema generation counter against P4.

  87121. ** The cookie changes its value whenever the database schema changes.

  87122. ** This operation is used to detect when that the cookie has changed

  87123. ** and that the current process needs to reread the schema.  If the schema

  87124. ** cookie in P3 differs from the schema cookie in the database header or

  87125. ** if the schema generation counter in P4 differs from the current

  87126. ** generation counter, then an SQLITE_SCHEMA error is raised and execution

  87127. ** halts.  The sqlite3_step() wrapper function might then reprepare the

  87128. ** statement and rerun it from the beginning.

  87129. */

  87130. case OP_Transaction: {

  87131.   Btree *pBt;

  87132.   int iMeta = 0;

  87133. 

  87134.   assert( p->bIsReader );

  87135.   assert( p->readOnly==0 || pOp->p2==0 );

  87136.   assert( pOp->p1>=0 && pOp->p1<db->nDb );

  87137.   assert( DbMaskTest(p->btreeMask, pOp->p1) );

  87138.   if( pOp->p2 && (db->flags & SQLITE_QueryOnly)!=0 ){

  87139.     rc = SQLITE_READONLY;

  87140.     goto abort_due_to_error;

  87141.   }

  87142.   pBt = db->aDb[pOp->p1].pBt;

  87143. 

  87144.   if( pBt ){

  87145.     rc = sqlite3BtreeBeginTrans(pBt, pOp->p2, &iMeta);

  87146.     testcase( rc==SQLITE_BUSY_SNAPSHOT );

  87147.     testcase( rc==SQLITE_BUSY_RECOVERY );

  87148.     if( rc!=SQLITE_OK ){

  87149.       if( (rc&0xff)==SQLITE_BUSY ){

  87150.         p->pc = (int)(pOp - aOp);

  87151.         p->rc = rc;

  87152.         goto vdbe_return;

  87153.       }

  87154.       goto abort_due_to_error;

  87155.     }

  87156. 

  87157.     if( pOp->p2 && p->usesStmtJournal 

  87158.      && (db->autoCommit==0 || db->nVdbeRead>1) 

  87159.     ){

  87160.       assert( sqlite3BtreeIsInTrans(pBt) );

  87161.       if( p->iStatement==0 ){

  87162.         assert( db->nStatement>=0 && db->nSavepoint>=0 );

  87163.         db->nStatement++; 

  87164.         p->iStatement = db->nSavepoint + db->nStatement;

  87165.       }

  87166. 

  87167.       rc = sqlite3VtabSavepoint(db, SAVEPOINT_BEGIN, p->iStatement-1);

  87168.       if( rc==SQLITE_OK ){

  87169.         rc = sqlite3BtreeBeginStmt(pBt, p->iStatement);

  87170.       }

  87171. 

  87172.       /* Store the current value of the database handles deferred constraint

  87173.       ** counter. If the statement transaction needs to be rolled back,

  87174.       ** the value of this counter needs to be restored too.  */

  87175.       p->nStmtDefCons = db->nDeferredCons;

  87176.       p->nStmtDefImmCons = db->nDeferredImmCons;

  87177.     }

  87178.   }

  87179.   assert( pOp->p5==0 || pOp->p4type==P4_INT32 );

  87180.   if( pOp->p5

  87181.    && (iMeta!=pOp->p3

  87182.       || db->aDb[pOp->p1].pSchema->iGeneration!=pOp->p4.i)

  87183.   ){

  87184.     /*

  87185.     ** IMPLEMENTATION-OF: R-03189-51135 As each SQL statement runs, the schema

  87186.     ** version is checked to ensure that the schema has not changed since the

  87187.     ** SQL statement was prepared.

  87188.     */

  87189.     sqlite3DbFree(db, p->zErrMsg);

  87190.     p->zErrMsg = sqlite3DbStrDup(db, "database schema has changed");

  87191.     /* If the schema-cookie from the database file matches the cookie 

  87192.     ** stored with the in-memory representation of the schema, do

  87193.     ** not reload the schema from the database file.

  87194.     **

  87195.     ** If virtual-tables are in use, this is not just an optimization.

  87196.     ** Often, v-tables store their data in other SQLite tables, which

  87197.     ** are queried from within xNext() and other v-table methods using

  87198.     ** prepared queries. If such a query is out-of-date, we do not want to

  87199.     ** discard the database schema, as the user code implementing the

  87200.     ** v-table would have to be ready for the sqlite3_vtab structure itself

  87201.     ** to be invalidated whenever sqlite3_step() is called from within 

  87202.     ** a v-table method.

  87203.     */

  87204.     if( db->aDb[pOp->p1].pSchema->schema_cookie!=iMeta ){

  87205.       sqlite3ResetOneSchema(db, pOp->p1);

  87206.     }

  87207.     p->expired = 1;

  87208.     rc = SQLITE_SCHEMA;

  87209.   }

  87210.   if( rc ) goto abort_due_to_error;

  87211.   break;

  87212. }

  87213. 

  87214. /* Opcode: ReadCookie P1 P2 P3 * *

  87215. **

  87216. ** Read cookie number P3 from database P1 and write it into register P2.

  87217. ** P3==1 is the schema version.  P3==2 is the database format.

  87218. ** P3==3 is the recommended pager cache size, and so forth.  P1==0 is

  87219. ** the main database file and P1==1 is the database file used to store

  87220. ** temporary tables.

  87221. **

  87222. ** There must be a read-lock on the database (either a transaction

  87223. ** must be started or there must be an open cursor) before

  87224. ** executing this instruction.

  87225. */

  87226. case OP_ReadCookie: {               /* out2 */

  87227.   int iMeta;

  87228.   int iDb;

  87229.   int iCookie;

  87230. 

  87231.   assert( p->bIsReader );

  87232.   iDb = pOp->p1;

  87233.   iCookie = pOp->p3;

  87234.   assert( pOp->p3<SQLITE_N_BTREE_META );

  87235.   assert( iDb>=0 && iDb<db->nDb );

  87236.   assert( db->aDb[iDb].pBt!=0 );

  87237.   assert( DbMaskTest(p->btreeMask, iDb) );

  87238. 

  87239.   sqlite3BtreeGetMeta(db->aDb[iDb].pBt, iCookie, (u32 *)&iMeta);

  87240.   pOut = out2Prerelease(p, pOp);

  87241.   pOut->u.i = iMeta;

  87242.   break;

  87243. }

  87244. 

  87245. /* Opcode: SetCookie P1 P2 P3 * *

  87246. **

  87247. ** Write the integer value P3 into cookie number P2 of database P1.

  87248. ** P2==1 is the schema version.  P2==2 is the database format.

  87249. ** P2==3 is the recommended pager cache 

  87250. ** size, and so forth.  P1==0 is the main database file and P1==1 is the 

  87251. ** database file used to store temporary tables.

  87252. **

  87253. ** A transaction must be started before executing this opcode.

  87254. */

  87255. case OP_SetCookie: {

  87256.   Db *pDb;

  87257. 

  87258.   sqlite3VdbeIncrWriteCounter(p, 0);

  87259.   assert( pOp->p2<SQLITE_N_BTREE_META );

  87260.   assert( pOp->p1>=0 && pOp->p1<db->nDb );

  87261.   assert( DbMaskTest(p->btreeMask, pOp->p1) );

  87262.   assert( p->readOnly==0 );

  87263.   pDb = &db->aDb[pOp->p1];

  87264.   assert( pDb->pBt!=0 );

  87265.   assert( sqlite3SchemaMutexHeld(db, pOp->p1, 0) );

  87266.   /* See note about index shifting on OP_ReadCookie */

  87267.   rc = sqlite3BtreeUpdateMeta(pDb->pBt, pOp->p2, pOp->p3);

  87268.   if( pOp->p2==BTREE_SCHEMA_VERSION ){

  87269.     /* When the schema cookie changes, record the new cookie internally */

  87270.     pDb->pSchema->schema_cookie = pOp->p3;

  87271.     db->mDbFlags |= DBFLAG_SchemaChange;

  87272.   }else if( pOp->p2==BTREE_FILE_FORMAT ){

  87273.     /* Record changes in the file format */

  87274.     pDb->pSchema->file_format = pOp->p3;

  87275.   }

  87276.   if( pOp->p1==1 ){

  87277.     /* Invalidate all prepared statements whenever the TEMP database

  87278.     ** schema is changed.  Ticket #1644 */

  87279.     sqlite3ExpirePreparedStatements(db, 0);

  87280.     p->expired = 0;

  87281.   }

  87282.   if( rc ) goto abort_due_to_error;

  87283.   break;

  87284. }

  87285. 

  87286. /* Opcode: OpenRead P1 P2 P3 P4 P5

  87287. ** Synopsis: root=P2 iDb=P3

  87288. **

  87289. ** Open a read-only cursor for the database table whose root page is

  87290. ** P2 in a database file.  The database file is determined by P3. 

  87291. ** P3==0 means the main database, P3==1 means the database used for 

  87292. ** temporary tables, and P3>1 means used the corresponding attached

  87293. ** database.  Give the new cursor an identifier of P1.  The P1

  87294. ** values need not be contiguous but all P1 values should be small integers.

  87295. ** It is an error for P1 to be negative.

  87296. **

  87297. ** Allowed P5 bits:

  87298. ** <ul>

  87299. ** <li>  <b>0x02 OPFLAG_SEEKEQ</b>: This cursor will only be used for

  87300. **       equality lookups (implemented as a pair of opcodes OP_SeekGE/OP_IdxGT

  87301. **       of OP_SeekLE/OP_IdxGT)

  87302. ** </ul>

  87303. **

  87304. ** The P4 value may be either an integer (P4_INT32) or a pointer to

  87305. ** a KeyInfo structure (P4_KEYINFO). If it is a pointer to a KeyInfo 

  87306. ** object, then table being opened must be an [index b-tree] where the

  87307. ** KeyInfo object defines the content and collating 

  87308. ** sequence of that index b-tree. Otherwise, if P4 is an integer 

  87309. ** value, then the table being opened must be a [table b-tree] with a

  87310. ** number of columns no less than the value of P4.

  87311. **

  87312. ** See also: OpenWrite, ReopenIdx

  87313. */

  87314. /* Opcode: ReopenIdx P1 P2 P3 P4 P5

  87315. ** Synopsis: root=P2 iDb=P3

  87316. **

  87317. ** The ReopenIdx opcode works like OP_OpenRead except that it first

  87318. ** checks to see if the cursor on P1 is already open on the same

  87319. ** b-tree and if it is this opcode becomes a no-op.  In other words,

  87320. ** if the cursor is already open, do not reopen it.

  87321. **

  87322. ** The ReopenIdx opcode may only be used with P5==0 or P5==OPFLAG_SEEKEQ

  87323. ** and with P4 being a P4_KEYINFO object.  Furthermore, the P3 value must

  87324. ** be the same as every other ReopenIdx or OpenRead for the same cursor

  87325. ** number.

  87326. **

  87327. ** Allowed P5 bits:

  87328. ** <ul>

  87329. ** <li>  <b>0x02 OPFLAG_SEEKEQ</b>: This cursor will only be used for

  87330. **       equality lookups (implemented as a pair of opcodes OP_SeekGE/OP_IdxGT

  87331. **       of OP_SeekLE/OP_IdxGT)

  87332. ** </ul>

  87333. **

  87334. ** See also: OP_OpenRead, OP_OpenWrite

  87335. */

  87336. /* Opcode: OpenWrite P1 P2 P3 P4 P5

  87337. ** Synopsis: root=P2 iDb=P3

  87338. **

  87339. ** Open a read/write cursor named P1 on the table or index whose root

  87340. ** page is P2 (or whose root page is held in register P2 if the

  87341. ** OPFLAG_P2ISREG bit is set in P5 - see below).

  87342. **

  87343. ** The P4 value may be either an integer (P4_INT32) or a pointer to

  87344. ** a KeyInfo structure (P4_KEYINFO). If it is a pointer to a KeyInfo 

  87345. ** object, then table being opened must be an [index b-tree] where the

  87346. ** KeyInfo object defines the content and collating 

  87347. ** sequence of that index b-tree. Otherwise, if P4 is an integer 

  87348. ** value, then the table being opened must be a [table b-tree] with a

  87349. ** number of columns no less than the value of P4.

  87350. **

  87351. ** Allowed P5 bits:

  87352. ** <ul>

  87353. ** <li>  <b>0x02 OPFLAG_SEEKEQ</b>: This cursor will only be used for

  87354. **       equality lookups (implemented as a pair of opcodes OP_SeekGE/OP_IdxGT

  87355. **       of OP_SeekLE/OP_IdxGT)

  87356. ** <li>  <b>0x08 OPFLAG_FORDELETE</b>: This cursor is used only to seek

  87357. **       and subsequently delete entries in an index btree.  This is a

  87358. **       hint to the storage engine that the storage engine is allowed to

  87359. **       ignore.  The hint is not used by the official SQLite b*tree storage

  87360. **       engine, but is used by COMDB2.

  87361. ** <li>  <b>0x10 OPFLAG_P2ISREG</b>: Use the content of register P2

  87362. **       as the root page, not the value of P2 itself.

  87363. ** </ul>

  87364. **

  87365. ** This instruction works like OpenRead except that it opens the cursor

  87366. ** in read/write mode.

  87367. **

  87368. ** See also: OP_OpenRead, OP_ReopenIdx

  87369. */

  87370. case OP_ReopenIdx: {

  87371.   int nField;

  87372.   KeyInfo *pKeyInfo;

  87373.   int p2;

  87374.   int iDb;

  87375.   int wrFlag;

  87376.   Btree *pX;

  87377.   VdbeCursor *pCur;

  87378.   Db *pDb;

  87379. 

  87380.   assert( pOp->p5==0 || pOp->p5==OPFLAG_SEEKEQ );

  87381.   assert( pOp->p4type==P4_KEYINFO );

  87382.   pCur = p->apCsr[pOp->p1];

  87383.   if( pCur && pCur->pgnoRoot==(u32)pOp->p2 ){

  87384.     assert( pCur->iDb==pOp->p3 );      /* Guaranteed by the code generator */

  87385.     goto open_cursor_set_hints;

  87386.   }

  87387.   /* If the cursor is not currently open or is open on a different

  87388.   ** index, then fall through into OP_OpenRead to force a reopen */

  87389. case OP_OpenRead:

  87390. case OP_OpenWrite:

  87391. 

  87392.   assert( pOp->opcode==OP_OpenWrite || pOp->p5==0 || pOp->p5==OPFLAG_SEEKEQ );

  87393.   assert( p->bIsReader );

  87394.   assert( pOp->opcode==OP_OpenRead || pOp->opcode==OP_ReopenIdx

  87395.           || p->readOnly==0 );

  87396. 

  87397.   if( p->expired==1 ){

  87398.     rc = SQLITE_ABORT_ROLLBACK;

  87399.     goto abort_due_to_error;

  87400.   }

  87401. 

  87402.   nField = 0;

  87403.   pKeyInfo = 0;

  87404.   p2 = pOp->p2;

  87405.   iDb = pOp->p3;

  87406.   assert( iDb>=0 && iDb<db->nDb );

  87407.   assert( DbMaskTest(p->btreeMask, iDb) );

  87408.   pDb = &db->aDb[iDb];

  87409.   pX = pDb->pBt;

  87410.   assert( pX!=0 );

  87411.   if( pOp->opcode==OP_OpenWrite ){

  87412.     assert( OPFLAG_FORDELETE==BTREE_FORDELETE );

  87413.     wrFlag = BTREE_WRCSR | (pOp->p5 & OPFLAG_FORDELETE);

  87414.     assert( sqlite3SchemaMutexHeld(db, iDb, 0) );

  87415.     if( pDb->pSchema->file_format < p->minWriteFileFormat ){

  87416.       p->minWriteFileFormat = pDb->pSchema->file_format;

  87417.     }

  87418.   }else{

  87419.     wrFlag = 0;

  87420.   }

  87421.   if( pOp->p5 & OPFLAG_P2ISREG ){

  87422.     assert( p2>0 );

  87423.     assert( p2<=(p->nMem+1 - p->nCursor) );

  87424.     assert( pOp->opcode==OP_OpenWrite );

  87425.     pIn2 = &aMem[p2];

  87426.     assert( memIsValid(pIn2) );

  87427.     assert( (pIn2->flags & MEM_Int)!=0 );

  87428.     sqlite3VdbeMemIntegerify(pIn2);

  87429.     p2 = (int)pIn2->u.i;

  87430.     /* The p2 value always comes from a prior OP_CreateBtree opcode and

  87431.     ** that opcode will always set the p2 value to 2 or more or else fail.

  87432.     ** If there were a failure, the prepared statement would have halted

  87433.     ** before reaching this instruction. */

  87434.     assert( p2>=2 );

  87435.   }

  87436.   if( pOp->p4type==P4_KEYINFO ){

  87437.     pKeyInfo = pOp->p4.pKeyInfo;

  87438.     assert( pKeyInfo->enc==ENC(db) );

  87439.     assert( pKeyInfo->db==db );

  87440.     nField = pKeyInfo->nAllField;

  87441.   }else if( pOp->p4type==P4_INT32 ){

  87442.     nField = pOp->p4.i;

  87443.   }

  87444.   assert( pOp->p1>=0 );

  87445.   assert( nField>=0 );

  87446.   testcase( nField==0 );  /* Table with INTEGER PRIMARY KEY and nothing else */

  87447.   pCur = allocateCursor(p, pOp->p1, nField, iDb, CURTYPE_BTREE);

  87448.   if( pCur==0 ) goto no_mem;

  87449.   pCur->nullRow = 1;

  87450.   pCur->isOrdered = 1;

  87451.   pCur->pgnoRoot = p2;

  87452. #ifdef SQLITE_DEBUG

  87453.   pCur->wrFlag = wrFlag;

  87454. #endif

  87455.   rc = sqlite3BtreeCursor(pX, p2, wrFlag, pKeyInfo, pCur->uc.pCursor);

  87456.   pCur->pKeyInfo = pKeyInfo;

  87457.   /* Set the VdbeCursor.isTable variable. Previous versions of

  87458.   ** SQLite used to check if the root-page flags were sane at this point

  87459.   ** and report database corruption if they were not, but this check has

  87460.   ** since moved into the btree layer.  */  

  87461.   pCur->isTable = pOp->p4type!=P4_KEYINFO;

  87462. 

  87463. open_cursor_set_hints:

  87464.   assert( OPFLAG_BULKCSR==BTREE_BULKLOAD );

  87465.   assert( OPFLAG_SEEKEQ==BTREE_SEEK_EQ );

  87466.   testcase( pOp->p5 & OPFLAG_BULKCSR );

  87467. #ifdef SQLITE_ENABLE_CURSOR_HINTS

  87468.   testcase( pOp->p2 & OPFLAG_SEEKEQ );

  87469. #endif

  87470.   sqlite3BtreeCursorHintFlags(pCur->uc.pCursor,

  87471.                                (pOp->p5 & (OPFLAG_BULKCSR|OPFLAG_SEEKEQ)));

  87472.   if( rc ) goto abort_due_to_error;

  87473.   break;

  87474. }

  87475. 

  87476. /* Opcode: OpenDup P1 P2 * * *

  87477. **

  87478. ** Open a new cursor P1 that points to the same ephemeral table as

  87479. ** cursor P2.  The P2 cursor must have been opened by a prior OP_OpenEphemeral

  87480. ** opcode.  Only ephemeral cursors may be duplicated.

  87481. **

  87482. ** Duplicate ephemeral cursors are used for self-joins of materialized views.

  87483. */

  87484. case OP_OpenDup: {

  87485.   VdbeCursor *pOrig;    /* The original cursor to be duplicated */

  87486.   VdbeCursor *pCx;      /* The new cursor */

  87487. 

  87488.   pOrig = p->apCsr[pOp->p2];

  87489.   assert( pOrig->pBtx!=0 );  /* Only ephemeral cursors can be duplicated */

  87490. 

  87491.   pCx = allocateCursor(p, pOp->p1, pOrig->nField, -1, CURTYPE_BTREE);

  87492.   if( pCx==0 ) goto no_mem;

  87493.   pCx->nullRow = 1;

  87494.   pCx->isEphemeral = 1;

  87495.   pCx->pKeyInfo = pOrig->pKeyInfo;

  87496.   pCx->isTable = pOrig->isTable;

  87497.   pCx->pgnoRoot = pOrig->pgnoRoot;

  87498.   pCx->isOrdered = pOrig->isOrdered;

  87499.   rc = sqlite3BtreeCursor(pOrig->pBtx, pCx->pgnoRoot, BTREE_WRCSR,

  87500.                           pCx->pKeyInfo, pCx->uc.pCursor);

  87501.   /* The sqlite3BtreeCursor() routine can only fail for the first cursor

  87502.   ** opened for a database.  Since there is already an open cursor when this

  87503.   ** opcode is run, the sqlite3BtreeCursor() cannot fail */

  87504.   assert( rc==SQLITE_OK );

  87505.   break;

  87506. }

  87507. 

  87508. 

  87509. /* Opcode: OpenEphemeral P1 P2 * P4 P5

  87510. ** Synopsis: nColumn=P2

  87511. **

  87512. ** Open a new cursor P1 to a transient table.

  87513. ** The cursor is always opened read/write even if 

  87514. ** the main database is read-only.  The ephemeral

  87515. ** table is deleted automatically when the cursor is closed.

  87516. **

  87517. ** If the cursor P1 is already opened on an ephemeral table, the table

  87518. ** is cleared (all content is erased).

  87519. **

  87520. ** P2 is the number of columns in the ephemeral table.

  87521. ** The cursor points to a BTree table if P4==0 and to a BTree index

  87522. ** if P4 is not 0.  If P4 is not NULL, it points to a KeyInfo structure

  87523. ** that defines the format of keys in the index.

  87524. **

  87525. ** The P5 parameter can be a mask of the BTREE_* flags defined

  87526. ** in btree.h.  These flags control aspects of the operation of

  87527. ** the btree.  The BTREE_OMIT_JOURNAL and BTREE_SINGLE flags are

  87528. ** added automatically.

  87529. */

  87530. /* Opcode: OpenAutoindex P1 P2 * P4 *

  87531. ** Synopsis: nColumn=P2

  87532. **

  87533. ** This opcode works the same as OP_OpenEphemeral.  It has a

  87534. ** different name to distinguish its use.  Tables created using

  87535. ** by this opcode will be used for automatically created transient

  87536. ** indices in joins.

  87537. */

  87538. case OP_OpenAutoindex: 

  87539. case OP_OpenEphemeral: {

  87540.   VdbeCursor *pCx;

  87541.   KeyInfo *pKeyInfo;

  87542. 

  87543.   static const int vfsFlags = 

  87544.       SQLITE_OPEN_READWRITE |

  87545.       SQLITE_OPEN_CREATE |

  87546.       SQLITE_OPEN_EXCLUSIVE |

  87547.       SQLITE_OPEN_DELETEONCLOSE |

  87548.       SQLITE_OPEN_TRANSIENT_DB;

  87549.   assert( pOp->p1>=0 );

  87550.   assert( pOp->p2>=0 );

  87551.   pCx = p->apCsr[pOp->p1];

  87552.   if( pCx ){

  87553.     /* If the ephermeral table is already open, erase all existing content

  87554.     ** so that the table is empty again, rather than creating a new table. */

  87555.     assert( pCx->isEphemeral );

  87556.     pCx->seqCount = 0;

  87557.     pCx->cacheStatus = CACHE_STALE;

  87558.     if( pCx->pBtx ){

  87559.       rc = sqlite3BtreeClearTable(pCx->pBtx, pCx->pgnoRoot, 0);

  87560.     }

  87561.   }else{

  87562.     pCx = allocateCursor(p, pOp->p1, pOp->p2, -1, CURTYPE_BTREE);

  87563.     if( pCx==0 ) goto no_mem;

  87564.     pCx->isEphemeral = 1;

  87565.     rc = sqlite3BtreeOpen(db->pVfs, 0, db, &pCx->pBtx, 

  87566.                           BTREE_OMIT_JOURNAL | BTREE_SINGLE | pOp->p5,

  87567.                           vfsFlags);

  87568.     if( rc==SQLITE_OK ){

  87569.       rc = sqlite3BtreeBeginTrans(pCx->pBtx, 1, 0);

  87570.     }

  87571.     if( rc==SQLITE_OK ){

  87572.       /* If a transient index is required, create it by calling

  87573.       ** sqlite3BtreeCreateTable() with the BTREE_BLOBKEY flag before

  87574.       ** opening it. If a transient table is required, just use the

  87575.       ** automatically created table with root-page 1 (an BLOB_INTKEY table).

  87576.       */

  87577.       if( (pCx->pKeyInfo = pKeyInfo = pOp->p4.pKeyInfo)!=0 ){

  87578.         assert( pOp->p4type==P4_KEYINFO );

  87579.         rc = sqlite3BtreeCreateTable(pCx->pBtx, (int*)&pCx->pgnoRoot,

  87580.                                      BTREE_BLOBKEY | pOp->p5); 

  87581.         if( rc==SQLITE_OK ){

  87582.           assert( pCx->pgnoRoot==MASTER_ROOT+1 );

  87583.           assert( pKeyInfo->db==db );

  87584.           assert( pKeyInfo->enc==ENC(db) );

  87585.           rc = sqlite3BtreeCursor(pCx->pBtx, pCx->pgnoRoot, BTREE_WRCSR,

  87586.                                   pKeyInfo, pCx->uc.pCursor);

  87587.         }

  87588.         pCx->isTable = 0;

  87589.       }else{

  87590.         pCx->pgnoRoot = MASTER_ROOT;

  87591.         rc = sqlite3BtreeCursor(pCx->pBtx, MASTER_ROOT, BTREE_WRCSR,

  87592.                                 0, pCx->uc.pCursor);

  87593.         pCx->isTable = 1;

  87594.       }

  87595.     }

  87596.     pCx->isOrdered = (pOp->p5!=BTREE_UNORDERED);

  87597.   }

  87598.   if( rc ) goto abort_due_to_error;

  87599.   pCx->nullRow = 1;

  87600.   break;

  87601. }

  87602. 

  87603. /* Opcode: SorterOpen P1 P2 P3 P4 *

  87604. **

  87605. ** This opcode works like OP_OpenEphemeral except that it opens

  87606. ** a transient index that is specifically designed to sort large

  87607. ** tables using an external merge-sort algorithm.

  87608. **

  87609. ** If argument P3 is non-zero, then it indicates that the sorter may

  87610. ** assume that a stable sort considering the first P3 fields of each

  87611. ** key is sufficient to produce the required results.

  87612. */

  87613. case OP_SorterOpen: {

  87614.   VdbeCursor *pCx;

  87615. 

  87616.   assert( pOp->p1>=0 );

  87617.   assert( pOp->p2>=0 );

  87618.   pCx = allocateCursor(p, pOp->p1, pOp->p2, -1, CURTYPE_SORTER);

  87619.   if( pCx==0 ) goto no_mem;

  87620.   pCx->pKeyInfo = pOp->p4.pKeyInfo;

  87621.   assert( pCx->pKeyInfo->db==db );

  87622.   assert( pCx->pKeyInfo->enc==ENC(db) );

  87623.   rc = sqlite3VdbeSorterInit(db, pOp->p3, pCx);

  87624.   if( rc ) goto abort_due_to_error;

  87625.   break;

  87626. }

  87627. 

  87628. /* Opcode: SequenceTest P1 P2 * * *

  87629. ** Synopsis: if( cursor[P1].ctr++ ) pc = P2

  87630. **

  87631. ** P1 is a sorter cursor. If the sequence counter is currently zero, jump

  87632. ** to P2. Regardless of whether or not the jump is taken, increment the

  87633. ** the sequence value.

  87634. */

  87635. case OP_SequenceTest: {

  87636.   VdbeCursor *pC;

  87637.   assert( pOp->p1>=0 && pOp->p1<p->nCursor );

  87638.   pC = p->apCsr[pOp->p1];

  87639.   assert( isSorter(pC) );

  87640.   if( (pC->seqCount++)==0 ){

  87641.     goto jump_to_p2;

  87642.   }

  87643.   break;

  87644. }

  87645. 

  87646. /* Opcode: OpenPseudo P1 P2 P3 * *

  87647. ** Synopsis: P3 columns in r[P2]

  87648. **

  87649. ** Open a new cursor that points to a fake table that contains a single

  87650. ** row of data.  The content of that one row is the content of memory

  87651. ** register P2.  In other words, cursor P1 becomes an alias for the 

  87652. ** MEM_Blob content contained in register P2.

  87653. **

  87654. ** A pseudo-table created by this opcode is used to hold a single

  87655. ** row output from the sorter so that the row can be decomposed into

  87656. ** individual columns using the OP_Column opcode.  The OP_Column opcode

  87657. ** is the only cursor opcode that works with a pseudo-table.

  87658. **

  87659. ** P3 is the number of fields in the records that will be stored by

  87660. ** the pseudo-table.

  87661. */

  87662. case OP_OpenPseudo: {

  87663.   VdbeCursor *pCx;

  87664. 

  87665.   assert( pOp->p1>=0 );

  87666.   assert( pOp->p3>=0 );

  87667.   pCx = allocateCursor(p, pOp->p1, pOp->p3, -1, CURTYPE_PSEUDO);

  87668.   if( pCx==0 ) goto no_mem;

  87669.   pCx->nullRow = 1;

  87670.   pCx->seekResult = pOp->p2;

  87671.   pCx->isTable = 1;

  87672.   /* Give this pseudo-cursor a fake BtCursor pointer so that pCx

  87673.   ** can be safely passed to sqlite3VdbeCursorMoveto().  This avoids a test

  87674.   ** for pCx->eCurType==CURTYPE_BTREE inside of sqlite3VdbeCursorMoveto()

  87675.   ** which is a performance optimization */

  87676.   pCx->uc.pCursor = sqlite3BtreeFakeValidCursor();

  87677.   assert( pOp->p5==0 );

  87678.   break;

  87679. }

  87680. 

  87681. /* Opcode: Close P1 * * * *

  87682. **

  87683. ** Close a cursor previously opened as P1.  If P1 is not

  87684. ** currently open, this instruction is a no-op.

  87685. */

  87686. case OP_Close: {

  87687.   assert( pOp->p1>=0 && pOp->p1<p->nCursor );

  87688.   sqlite3VdbeFreeCursor(p, p->apCsr[pOp->p1]);

  87689.   p->apCsr[pOp->p1] = 0;

  87690.   break;

  87691. }

  87692. 

  87693. #ifdef SQLITE_ENABLE_COLUMN_USED_MASK

  87694. /* Opcode: ColumnsUsed P1 * * P4 *

  87695. **

  87696. ** This opcode (which only exists if SQLite was compiled with

  87697. ** SQLITE_ENABLE_COLUMN_USED_MASK) identifies which columns of the

  87698. ** table or index for cursor P1 are used.  P4 is a 64-bit integer

  87699. ** (P4_INT64) in which the first 63 bits are one for each of the

  87700. ** first 63 columns of the table or index that are actually used

  87701. ** by the cursor.  The high-order bit is set if any column after

  87702. ** the 64th is used.

  87703. */

  87704. case OP_ColumnsUsed: {

  87705.   VdbeCursor *pC;

  87706.   pC = p->apCsr[pOp->p1];

  87707.   assert( pC->eCurType==CURTYPE_BTREE );

  87708.   pC->maskUsed = *(u64*)pOp->p4.pI64;

  87709.   break;

  87710. }

  87711. #endif

  87712. 

  87713. /* Opcode: SeekGE P1 P2 P3 P4 *

  87714. ** Synopsis: key=r[P3@P4]

  87715. **

  87716. ** If cursor P1 refers to an SQL table (B-Tree that uses integer keys), 

  87717. ** use the value in register P3 as the key.  If cursor P1 refers 

  87718. ** to an SQL index, then P3 is the first in an array of P4 registers 

  87719. ** that are used as an unpacked index key. 

  87720. **

  87721. ** Reposition cursor P1 so that  it points to the smallest entry that 

  87722. ** is greater than or equal to the key value. If there are no records 

  87723. ** greater than or equal to the key and P2 is not zero, then jump to P2.

  87724. **

  87725. ** If the cursor P1 was opened using the OPFLAG_SEEKEQ flag, then this

  87726. ** opcode will always land on a record that equally equals the key, or

  87727. ** else jump immediately to P2.  When the cursor is OPFLAG_SEEKEQ, this

  87728. ** opcode must be followed by an IdxLE opcode with the same arguments.

  87729. ** The IdxLE opcode will be skipped if this opcode succeeds, but the

  87730. ** IdxLE opcode will be used on subsequent loop iterations.

  87731. **

  87732. ** This opcode leaves the cursor configured to move in forward order,

  87733. ** from the beginning toward the end.  In other words, the cursor is

  87734. ** configured to use Next, not Prev.

  87735. **

  87736. ** See also: Found, NotFound, SeekLt, SeekGt, SeekLe

  87737. */

  87738. /* Opcode: SeekGT P1 P2 P3 P4 *

  87739. ** Synopsis: key=r[P3@P4]

  87740. **

  87741. ** If cursor P1 refers to an SQL table (B-Tree that uses integer keys), 

  87742. ** use the value in register P3 as a key. If cursor P1 refers 

  87743. ** to an SQL index, then P3 is the first in an array of P4 registers 

  87744. ** that are used as an unpacked index key. 

  87745. **

  87746. ** Reposition cursor P1 so that  it points to the smallest entry that 

  87747. ** is greater than the key value. If there are no records greater than 

  87748. ** the key and P2 is not zero, then jump to P2.

  87749. **

  87750. ** This opcode leaves the cursor configured to move in forward order,

  87751. ** from the beginning toward the end.  In other words, the cursor is

  87752. ** configured to use Next, not Prev.

  87753. **

  87754. ** See also: Found, NotFound, SeekLt, SeekGe, SeekLe

  87755. */

  87756. /* Opcode: SeekLT P1 P2 P3 P4 * 

  87757. ** Synopsis: key=r[P3@P4]

  87758. **

  87759. ** If cursor P1 refers to an SQL table (B-Tree that uses integer keys), 

  87760. ** use the value in register P3 as a key. If cursor P1 refers 

  87761. ** to an SQL index, then P3 is the first in an array of P4 registers 

  87762. ** that are used as an unpacked index key. 

  87763. **

  87764. ** Reposition cursor P1 so that  it points to the largest entry that 

  87765. ** is less than the key value. If there are no records less than 

  87766. ** the key and P2 is not zero, then jump to P2.

  87767. **

  87768. ** This opcode leaves the cursor configured to move in reverse order,

  87769. ** from the end toward the beginning.  In other words, the cursor is

  87770. ** configured to use Prev, not Next.

  87771. **

  87772. ** See also: Found, NotFound, SeekGt, SeekGe, SeekLe

  87773. */

  87774. /* Opcode: SeekLE P1 P2 P3 P4 *

  87775. ** Synopsis: key=r[P3@P4]

  87776. **

  87777. ** If cursor P1 refers to an SQL table (B-Tree that uses integer keys), 

  87778. ** use the value in register P3 as a key. If cursor P1 refers 

  87779. ** to an SQL index, then P3 is the first in an array of P4 registers 

  87780. ** that are used as an unpacked index key. 

  87781. **

  87782. ** Reposition cursor P1 so that it points to the largest entry that 

  87783. ** is less than or equal to the key value. If there are no records 

  87784. ** less than or equal to the key and P2 is not zero, then jump to P2.

  87785. **

  87786. ** This opcode leaves the cursor configured to move in reverse order,

  87787. ** from the end toward the beginning.  In other words, the cursor is

  87788. ** configured to use Prev, not Next.

  87789. **

  87790. ** If the cursor P1 was opened using the OPFLAG_SEEKEQ flag, then this

  87791. ** opcode will always land on a record that equally equals the key, or

  87792. ** else jump immediately to P2.  When the cursor is OPFLAG_SEEKEQ, this

  87793. ** opcode must be followed by an IdxGE opcode with the same arguments.

  87794. ** The IdxGE opcode will be skipped if this opcode succeeds, but the

  87795. ** IdxGE opcode will be used on subsequent loop iterations.

  87796. **

  87797. ** See also: Found, NotFound, SeekGt, SeekGe, SeekLt

  87798. */

  87799. case OP_SeekLT:         /* jump, in3, group */

  87800. case OP_SeekLE:         /* jump, in3, group */

  87801. case OP_SeekGE:         /* jump, in3, group */

  87802. case OP_SeekGT: {       /* jump, in3, group */

  87803.   int res;           /* Comparison result */

  87804.   int oc;            /* Opcode */

  87805.   VdbeCursor *pC;    /* The cursor to seek */

  87806.   UnpackedRecord r;  /* The key to seek for */

  87807.   int nField;        /* Number of columns or fields in the key */

  87808.   i64 iKey;          /* The rowid we are to seek to */

  87809.   int eqOnly;        /* Only interested in == results */

  87810. 

  87811.   assert( pOp->p1>=0 && pOp->p1<p->nCursor );

  87812.   assert( pOp->p2!=0 );

  87813.   pC = p->apCsr[pOp->p1];

  87814.   assert( pC!=0 );

  87815.   assert( pC->eCurType==CURTYPE_BTREE );

  87816.   assert( OP_SeekLE == OP_SeekLT+1 );

  87817.   assert( OP_SeekGE == OP_SeekLT+2 );

  87818.   assert( OP_SeekGT == OP_SeekLT+3 );

  87819.   assert( pC->isOrdered );

  87820.   assert( pC->uc.pCursor!=0 );

  87821.   oc = pOp->opcode;

  87822.   eqOnly = 0;

  87823.   pC->nullRow = 0;

  87824. #ifdef SQLITE_DEBUG

  87825.   pC->seekOp = pOp->opcode;

  87826. #endif

  87827. 

  87828.   pC->deferredMoveto = 0;

  87829.   pC->cacheStatus = CACHE_STALE;

  87830.   if( pC->isTable ){

  87831.     /* The BTREE_SEEK_EQ flag is only set on index cursors */

  87832.     assert( sqlite3BtreeCursorHasHint(pC->uc.pCursor, BTREE_SEEK_EQ)==0

  87833.               || CORRUPT_DB );

  87834. 

  87835.     /* The input value in P3 might be of any type: integer, real, string,

  87836.     ** blob, or NULL.  But it needs to be an integer before we can do

  87837.     ** the seek, so convert it. */

  87838.     pIn3 = &aMem[pOp->p3];

  87839.     if( (pIn3->flags & (MEM_Int|MEM_Real|MEM_IntReal|MEM_Str))==MEM_Str ){

  87840.       applyNumericAffinity(pIn3, 0);

  87841.     }

  87842.     iKey = sqlite3VdbeIntValue(pIn3);

  87843. 

  87844.     /* If the P3 value could not be converted into an integer without

  87845.     ** loss of information, then special processing is required... */

  87846.     if( (pIn3->flags & (MEM_Int|MEM_IntReal))==0 ){

  87847.       if( (pIn3->flags & MEM_Real)==0 ){

  87848.         if( (pIn3->flags & MEM_Null) || oc>=OP_SeekGE ){

  87849.           VdbeBranchTaken(1,2); goto jump_to_p2;

  87850.           break;

  87851.         }else{

  87852.           rc = sqlite3BtreeLast(pC->uc.pCursor, &res);

  87853.           if( rc!=SQLITE_OK ) goto abort_due_to_error;

  87854.           goto seek_not_found;

  87855.         }

  87856.       }else

  87857. 

  87858.       /* If the approximation iKey is larger than the actual real search

  87859.       ** term, substitute >= for > and < for <=. e.g. if the search term

  87860.       ** is 4.9 and the integer approximation 5:

  87861.       **

  87862.       **        (x >  4.9)    ->     (x >= 5)

  87863.       **        (x <= 4.9)    ->     (x <  5)

  87864.       */

  87865.       if( pIn3->u.r<(double)iKey ){

  87866.         assert( OP_SeekGE==(OP_SeekGT-1) );

  87867.         assert( OP_SeekLT==(OP_SeekLE-1) );

  87868.         assert( (OP_SeekLE & 0x0001)==(OP_SeekGT & 0x0001) );

  87869.         if( (oc & 0x0001)==(OP_SeekGT & 0x0001) ) oc--;

  87870.       }

  87871. 

  87872.       /* If the approximation iKey is smaller than the actual real search

  87873.       ** term, substitute <= for < and > for >=.  */

  87874.       else if( pIn3->u.r>(double)iKey ){

  87875.         assert( OP_SeekLE==(OP_SeekLT+1) );

  87876.         assert( OP_SeekGT==(OP_SeekGE+1) );

  87877.         assert( (OP_SeekLT & 0x0001)==(OP_SeekGE & 0x0001) );

  87878.         if( (oc & 0x0001)==(OP_SeekLT & 0x0001) ) oc++;

  87879.       }

  87880.     }

  87881.     rc = sqlite3BtreeMovetoUnpacked(pC->uc.pCursor, 0, (u64)iKey, 0, &res);

  87882.     pC->movetoTarget = iKey;  /* Used by OP_Delete */

  87883.     if( rc!=SQLITE_OK ){

  87884.       goto abort_due_to_error;

  87885.     }

  87886.   }else{

  87887.     /* For a cursor with the BTREE_SEEK_EQ hint, only the OP_SeekGE and

  87888.     ** OP_SeekLE opcodes are allowed, and these must be immediately followed

  87889.     ** by an OP_IdxGT or OP_IdxLT opcode, respectively, with the same key.

  87890.     */

  87891.     if( sqlite3BtreeCursorHasHint(pC->uc.pCursor, BTREE_SEEK_EQ) ){

  87892.       eqOnly = 1;

  87893.       assert( pOp->opcode==OP_SeekGE || pOp->opcode==OP_SeekLE );

  87894.       assert( pOp[1].opcode==OP_IdxLT || pOp[1].opcode==OP_IdxGT );

  87895.       assert( pOp[1].p1==pOp[0].p1 );

  87896.       assert( pOp[1].p2==pOp[0].p2 );

  87897.       assert( pOp[1].p3==pOp[0].p3 );

  87898.       assert( pOp[1].p4.i==pOp[0].p4.i );

  87899.     }

  87900. 

  87901.     nField = pOp->p4.i;

  87902.     assert( pOp->p4type==P4_INT32 );

  87903.     assert( nField>0 );

  87904.     r.pKeyInfo = pC->pKeyInfo;

  87905.     r.nField = (u16)nField;

  87906. 

  87907.     /* The next line of code computes as follows, only faster:

  87908.     **   if( oc==OP_SeekGT || oc==OP_SeekLE ){

  87909.     **     r.default_rc = -1;

  87910.     **   }else{

  87911.     **     r.default_rc = +1;

  87912.     **   }

  87913.     */

  87914.     r.default_rc = ((1 & (oc - OP_SeekLT)) ? -1 : +1);

  87915.     assert( oc!=OP_SeekGT || r.default_rc==-1 );

  87916.     assert( oc!=OP_SeekLE || r.default_rc==-1 );

  87917.     assert( oc!=OP_SeekGE || r.default_rc==+1 );

  87918.     assert( oc!=OP_SeekLT || r.default_rc==+1 );

  87919. 

  87920.     r.aMem = &aMem[pOp->p3];

  87921. #ifdef SQLITE_DEBUG

  87922.     { int i; for(i=0; i<r.nField; i++) assert( memIsValid(&r.aMem[i]) ); }

  87923. #endif

  87924.     r.eqSeen = 0;

  87925.     rc = sqlite3BtreeMovetoUnpacked(pC->uc.pCursor, &r, 0, 0, &res);

  87926.     if( rc!=SQLITE_OK ){

  87927.       goto abort_due_to_error;

  87928.     }

  87929.     if( eqOnly && r.eqSeen==0 ){

  87930.       assert( res!=0 );

  87931.       goto seek_not_found;

  87932.     }

  87933.   }

  87934. #ifdef SQLITE_TEST

  87935.   sqlite3_search_count++;

  87936. #endif

  87937.   if( oc>=OP_SeekGE ){  assert( oc==OP_SeekGE || oc==OP_SeekGT );

  87938.     if( res<0 || (res==0 && oc==OP_SeekGT) ){

  87939.       res = 0;

  87940.       rc = sqlite3BtreeNext(pC->uc.pCursor, 0);

  87941.       if( rc!=SQLITE_OK ){

  87942.         if( rc==SQLITE_DONE ){

  87943.           rc = SQLITE_OK;

  87944.           res = 1;

  87945.         }else{

  87946.           goto abort_due_to_error;

  87947.         }

  87948.       }

  87949.     }else{

  87950.       res = 0;

  87951.     }

  87952.   }else{

  87953.     assert( oc==OP_SeekLT || oc==OP_SeekLE );

  87954.     if( res>0 || (res==0 && oc==OP_SeekLT) ){

  87955.       res = 0;

  87956.       rc = sqlite3BtreePrevious(pC->uc.pCursor, 0);

  87957.       if( rc!=SQLITE_OK ){

  87958.         if( rc==SQLITE_DONE ){

  87959.           rc = SQLITE_OK;

  87960.           res = 1;

  87961.         }else{

  87962.           goto abort_due_to_error;

  87963.         }

  87964.       }

  87965.     }else{

  87966.       /* res might be negative because the table is empty.  Check to

  87967.       ** see if this is the case.

  87968.       */

  87969.       res = sqlite3BtreeEof(pC->uc.pCursor);

  87970.     }

  87971.   }

  87972. seek_not_found:

  87973.   assert( pOp->p2>0 );

  87974.   VdbeBranchTaken(res!=0,2);

  87975.   if( res ){

  87976.     goto jump_to_p2;

  87977.   }else if( eqOnly ){

  87978.     assert( pOp[1].opcode==OP_IdxLT || pOp[1].opcode==OP_IdxGT );

  87979.     pOp++; /* Skip the OP_IdxLt or OP_IdxGT that follows */

  87980.   }

  87981.   break;

  87982. }

  87983. 

  87984. /* Opcode: SeekHit P1 P2 * * *

  87985. ** Synopsis: seekHit=P2

  87986. **

  87987. ** Set the seekHit flag on cursor P1 to the value in P2.

  87988. ** The seekHit flag is used by the IfNoHope opcode.

  87989. **

  87990. ** P1 must be a valid b-tree cursor.  P2 must be a boolean value,

  87991. ** either 0 or 1.

  87992. */

  87993. case OP_SeekHit: {

  87994.   VdbeCursor *pC;

  87995.   assert( pOp->p1>=0 && pOp->p1<p->nCursor );

  87996.   pC = p->apCsr[pOp->p1];

  87997.   assert( pC!=0 );

  87998.   assert( pOp->p2==0 || pOp->p2==1 );

  87999.   pC->seekHit = pOp->p2 & 1;

  88000.   break;

  88001. }

  88002. 

  88003. /* Opcode: Found P1 P2 P3 P4 *

  88004. ** Synopsis: key=r[P3@P4]

  88005. **

  88006. ** If P4==0 then register P3 holds a blob constructed by MakeRecord.  If

  88007. ** P4>0 then register P3 is the first of P4 registers that form an unpacked

  88008. ** record.

  88009. **

  88010. ** Cursor P1 is on an index btree.  If the record identified by P3 and P4

  88011. ** is a prefix of any entry in P1 then a jump is made to P2 and

  88012. ** P1 is left pointing at the matching entry.

  88013. **

  88014. ** This operation leaves the cursor in a state where it can be

  88015. ** advanced in the forward direction.  The Next instruction will work,

  88016. ** but not the Prev instruction.

  88017. **

  88018. ** See also: NotFound, NoConflict, NotExists. SeekGe

  88019. */

  88020. /* Opcode: NotFound P1 P2 P3 P4 *

  88021. ** Synopsis: key=r[P3@P4]

  88022. **

  88023. ** If P4==0 then register P3 holds a blob constructed by MakeRecord.  If

  88024. ** P4>0 then register P3 is the first of P4 registers that form an unpacked

  88025. ** record.

  88026. ** 

  88027. ** Cursor P1 is on an index btree.  If the record identified by P3 and P4

  88028. ** is not the prefix of any entry in P1 then a jump is made to P2.  If P1 

  88029. ** does contain an entry whose prefix matches the P3/P4 record then control

  88030. ** falls through to the next instruction and P1 is left pointing at the

  88031. ** matching entry.

  88032. **

  88033. ** This operation leaves the cursor in a state where it cannot be

  88034. ** advanced in either direction.  In other words, the Next and Prev

  88035. ** opcodes do not work after this operation.

  88036. **

  88037. ** See also: Found, NotExists, NoConflict, IfNoHope

  88038. */

  88039. /* Opcode: IfNoHope P1 P2 P3 P4 *

  88040. ** Synopsis: key=r[P3@P4]

  88041. **

  88042. ** Register P3 is the first of P4 registers that form an unpacked

  88043. ** record.

  88044. **

  88045. ** Cursor P1 is on an index btree.  If the seekHit flag is set on P1, then

  88046. ** this opcode is a no-op.  But if the seekHit flag of P1 is clear, then

  88047. ** check to see if there is any entry in P1 that matches the

  88048. ** prefix identified by P3 and P4.  If no entry matches the prefix,

  88049. ** jump to P2.  Otherwise fall through.

  88050. **

  88051. ** This opcode behaves like OP_NotFound if the seekHit

  88052. ** flag is clear and it behaves like OP_Noop if the seekHit flag is set.

  88053. **

  88054. ** This opcode is used in IN clause processing for a multi-column key.

  88055. ** If an IN clause is attached to an element of the key other than the

  88056. ** left-most element, and if there are no matches on the most recent

  88057. ** seek over the whole key, then it might be that one of the key element

  88058. ** to the left is prohibiting a match, and hence there is "no hope" of

  88059. ** any match regardless of how many IN clause elements are checked.

  88060. ** In such a case, we abandon the IN clause search early, using this

  88061. ** opcode.  The opcode name comes from the fact that the

  88062. ** jump is taken if there is "no hope" of achieving a match.

  88063. **

  88064. ** See also: NotFound, SeekHit

  88065. */

  88066. /* Opcode: NoConflict P1 P2 P3 P4 *

  88067. ** Synopsis: key=r[P3@P4]

  88068. **

  88069. ** If P4==0 then register P3 holds a blob constructed by MakeRecord.  If

  88070. ** P4>0 then register P3 is the first of P4 registers that form an unpacked

  88071. ** record.

  88072. ** 

  88073. ** Cursor P1 is on an index btree.  If the record identified by P3 and P4

  88074. ** contains any NULL value, jump immediately to P2.  If all terms of the

  88075. ** record are not-NULL then a check is done to determine if any row in the

  88076. ** P1 index btree has a matching key prefix.  If there are no matches, jump

  88077. ** immediately to P2.  If there is a match, fall through and leave the P1

  88078. ** cursor pointing to the matching row.

  88079. **

  88080. ** This opcode is similar to OP_NotFound with the exceptions that the

  88081. ** branch is always taken if any part of the search key input is NULL.

  88082. **

  88083. ** This operation leaves the cursor in a state where it cannot be

  88084. ** advanced in either direction.  In other words, the Next and Prev

  88085. ** opcodes do not work after this operation.

  88086. **

  88087. ** See also: NotFound, Found, NotExists

  88088. */

  88089. case OP_IfNoHope: {     /* jump, in3 */

  88090.   VdbeCursor *pC;

  88091.   assert( pOp->p1>=0 && pOp->p1<p->nCursor );

  88092.   pC = p->apCsr[pOp->p1];

  88093.   assert( pC!=0 );

  88094.   if( pC->seekHit ) break;

  88095.   /* Fall through into OP_NotFound */

  88096. }

  88097. case OP_NoConflict:     /* jump, in3 */

  88098. case OP_NotFound:       /* jump, in3 */

  88099. case OP_Found: {        /* jump, in3 */

  88100.   int alreadyExists;

  88101.   int takeJump;

  88102.   int ii;

  88103.   VdbeCursor *pC;

  88104.   int res;

  88105.   UnpackedRecord *pFree;

  88106.   UnpackedRecord *pIdxKey;

  88107.   UnpackedRecord r;

  88108. 

  88109. #ifdef SQLITE_TEST

  88110.   if( pOp->opcode!=OP_NoConflict ) sqlite3_found_count++;

  88111. #endif

  88112. 

  88113.   assert( pOp->p1>=0 && pOp->p1<p->nCursor );

  88114.   assert( pOp->p4type==P4_INT32 );

  88115.   pC = p->apCsr[pOp->p1];

  88116.   assert( pC!=0 );

  88117. #ifdef SQLITE_DEBUG

  88118.   pC->seekOp = pOp->opcode;

  88119. #endif

  88120.   pIn3 = &aMem[pOp->p3];

  88121.   assert( pC->eCurType==CURTYPE_BTREE );

  88122.   assert( pC->uc.pCursor!=0 );

  88123.   assert( pC->isTable==0 );

  88124.   if( pOp->p4.i>0 ){

  88125.     r.pKeyInfo = pC->pKeyInfo;

  88126.     r.nField = (u16)pOp->p4.i;

  88127.     r.aMem = pIn3;

  88128. #ifdef SQLITE_DEBUG

  88129.     for(ii=0; ii<r.nField; ii++){

  88130.       assert( memIsValid(&r.aMem[ii]) );

  88131.       assert( (r.aMem[ii].flags & MEM_Zero)==0 || r.aMem[ii].n==0 );

  88132.       if( ii ) REGISTER_TRACE(pOp->p3+ii, &r.aMem[ii]);

  88133.     }

  88134. #endif

  88135.     pIdxKey = &r;

  88136.     pFree = 0;

  88137.   }else{

  88138.     assert( pIn3->flags & MEM_Blob );

  88139.     rc = ExpandBlob(pIn3);

  88140.     assert( rc==SQLITE_OK || rc==SQLITE_NOMEM );

  88141.     if( rc ) goto no_mem;

  88142.     pFree = pIdxKey = sqlite3VdbeAllocUnpackedRecord(pC->pKeyInfo);

  88143.     if( pIdxKey==0 ) goto no_mem;

  88144.     sqlite3VdbeRecordUnpack(pC->pKeyInfo, pIn3->n, pIn3->z, pIdxKey);

  88145.   }

  88146.   pIdxKey->default_rc = 0;

  88147.   takeJump = 0;

  88148.   if( pOp->opcode==OP_NoConflict ){

  88149.     /* For the OP_NoConflict opcode, take the jump if any of the

  88150.     ** input fields are NULL, since any key with a NULL will not

  88151.     ** conflict */

  88152.     for(ii=0; ii<pIdxKey->nField; ii++){

  88153.       if( pIdxKey->aMem[ii].flags & MEM_Null ){

  88154.         takeJump = 1;

  88155.         break;

  88156.       }

  88157.     }

  88158.   }

  88159.   rc = sqlite3BtreeMovetoUnpacked(pC->uc.pCursor, pIdxKey, 0, 0, &res);

  88160.   if( pFree ) sqlite3DbFreeNN(db, pFree);

  88161.   if( rc!=SQLITE_OK ){

  88162.     goto abort_due_to_error;

  88163.   }

  88164.   pC->seekResult = res;

  88165.   alreadyExists = (res==0);

  88166.   pC->nullRow = 1-alreadyExists;

  88167.   pC->deferredMoveto = 0;

  88168.   pC->cacheStatus = CACHE_STALE;

  88169.   if( pOp->opcode==OP_Found ){

  88170.     VdbeBranchTaken(alreadyExists!=0,2);

  88171.     if( alreadyExists ) goto jump_to_p2;

  88172.   }else{

  88173.     VdbeBranchTaken(takeJump||alreadyExists==0,2);

  88174.     if( takeJump || !alreadyExists ) goto jump_to_p2;

  88175.   }

  88176.   break;

  88177. }

  88178. 

  88179. /* Opcode: SeekRowid P1 P2 P3 * *

  88180. ** Synopsis: intkey=r[P3]

  88181. **

  88182. ** P1 is the index of a cursor open on an SQL table btree (with integer

  88183. ** keys).  If register P3 does not contain an integer or if P1 does not

  88184. ** contain a record with rowid P3 then jump immediately to P2.  

  88185. ** Or, if P2 is 0, raise an SQLITE_CORRUPT error. If P1 does contain

  88186. ** a record with rowid P3 then 

  88187. ** leave the cursor pointing at that record and fall through to the next

  88188. ** instruction.

  88189. **

  88190. ** The OP_NotExists opcode performs the same operation, but with OP_NotExists

  88191. ** the P3 register must be guaranteed to contain an integer value.  With this

  88192. ** opcode, register P3 might not contain an integer.

  88193. **

  88194. ** The OP_NotFound opcode performs the same operation on index btrees

  88195. ** (with arbitrary multi-value keys).

  88196. **

  88197. ** This opcode leaves the cursor in a state where it cannot be advanced

  88198. ** in either direction.  In other words, the Next and Prev opcodes will

  88199. ** not work following this opcode.

  88200. **

  88201. ** See also: Found, NotFound, NoConflict, SeekRowid

  88202. */

  88203. /* Opcode: NotExists P1 P2 P3 * *

  88204. ** Synopsis: intkey=r[P3]

  88205. **

  88206. ** P1 is the index of a cursor open on an SQL table btree (with integer

  88207. ** keys).  P3 is an integer rowid.  If P1 does not contain a record with

  88208. ** rowid P3 then jump immediately to P2.  Or, if P2 is 0, raise an

  88209. ** SQLITE_CORRUPT error. If P1 does contain a record with rowid P3 then 

  88210. ** leave the cursor pointing at that record and fall through to the next

  88211. ** instruction.

  88212. **

  88213. ** The OP_SeekRowid opcode performs the same operation but also allows the

  88214. ** P3 register to contain a non-integer value, in which case the jump is

  88215. ** always taken.  This opcode requires that P3 always contain an integer.

  88216. **

  88217. ** The OP_NotFound opcode performs the same operation on index btrees

  88218. ** (with arbitrary multi-value keys).

  88219. **

  88220. ** This opcode leaves the cursor in a state where it cannot be advanced

  88221. ** in either direction.  In other words, the Next and Prev opcodes will

  88222. ** not work following this opcode.

  88223. **

  88224. ** See also: Found, NotFound, NoConflict, SeekRowid

  88225. */

  88226. case OP_SeekRowid: {        /* jump, in3 */

  88227.   VdbeCursor *pC;

  88228.   BtCursor *pCrsr;

  88229.   int res;

  88230.   u64 iKey;

  88231. 

  88232.   pIn3 = &aMem[pOp->p3];

  88233.   testcase( pIn3->flags & MEM_Int );

  88234.   testcase( pIn3->flags & MEM_IntReal );

  88235.   if( (pIn3->flags & (MEM_Int|MEM_IntReal))==0 ){

  88236.     /* Make sure pIn3->u.i contains a valid integer representation of

  88237.     ** the key value, but do not change the datatype of the register, as

  88238.     ** other parts of the perpared statement might be depending on the

  88239.     ** current datatype. */

  88240.     u16 origFlags = pIn3->flags;

  88241.     int isNotInt;

  88242.     applyAffinity(pIn3, SQLITE_AFF_NUMERIC, encoding);

  88243.     isNotInt = (pIn3->flags & MEM_Int)==0;

  88244.     pIn3->flags = origFlags;

  88245.     if( isNotInt ) goto jump_to_p2;

  88246.   }

  88247.   /* Fall through into OP_NotExists */

  88248. case OP_NotExists:          /* jump, in3 */

  88249.   pIn3 = &aMem[pOp->p3];

  88250.   assert( (pIn3->flags & MEM_Int)!=0 || pOp->opcode==OP_SeekRowid );

  88251.   assert( pOp->p1>=0 && pOp->p1<p->nCursor );

  88252.   pC = p->apCsr[pOp->p1];

  88253.   assert( pC!=0 );

  88254. #ifdef SQLITE_DEBUG

  88255.   if( pOp->opcode==OP_SeekRowid ) pC->seekOp = OP_SeekRowid;

  88256. #endif

  88257.   assert( pC->isTable );

  88258.   assert( pC->eCurType==CURTYPE_BTREE );

  88259.   pCrsr = pC->uc.pCursor;

  88260.   assert( pCrsr!=0 );

  88261.   res = 0;

  88262.   iKey = pIn3->u.i;

  88263.   rc = sqlite3BtreeMovetoUnpacked(pCrsr, 0, iKey, 0, &res);

  88264.   assert( rc==SQLITE_OK || res==0 );

  88265.   pC->movetoTarget = iKey;  /* Used by OP_Delete */

  88266.   pC->nullRow = 0;

  88267.   pC->cacheStatus = CACHE_STALE;

  88268.   pC->deferredMoveto = 0;

  88269.   VdbeBranchTaken(res!=0,2);

  88270.   pC->seekResult = res;

  88271.   if( res!=0 ){

  88272.     assert( rc==SQLITE_OK );

  88273.     if( pOp->p2==0 ){

  88274.       rc = SQLITE_CORRUPT_BKPT;

  88275.     }else{

  88276.       goto jump_to_p2;

  88277.     }

  88278.   }

  88279.   if( rc ) goto abort_due_to_error;

  88280.   break;

  88281. }

  88282. 

  88283. /* Opcode: Sequence P1 P2 * * *

  88284. ** Synopsis: r[P2]=cursor[P1].ctr++

  88285. **

  88286. ** Find the next available sequence number for cursor P1.

  88287. ** Write the sequence number into register P2.

  88288. ** The sequence number on the cursor is incremented after this

  88289. ** instruction.  

  88290. */

  88291. case OP_Sequence: {           /* out2 */

  88292.   assert( pOp->p1>=0 && pOp->p1<p->nCursor );

  88293.   assert( p->apCsr[pOp->p1]!=0 );

  88294.   assert( p->apCsr[pOp->p1]->eCurType!=CURTYPE_VTAB );

  88295.   pOut = out2Prerelease(p, pOp);

  88296.   pOut->u.i = p->apCsr[pOp->p1]->seqCount++;

  88297.   break;

  88298. }

  88299. 

  88300. 

  88301. /* Opcode: NewRowid P1 P2 P3 * *

  88302. ** Synopsis: r[P2]=rowid

  88303. **

  88304. ** Get a new integer record number (a.k.a "rowid") used as the key to a table.

  88305. ** The record number is not previously used as a key in the database

  88306. ** table that cursor P1 points to.  The new record number is written

  88307. ** written to register P2.

  88308. **

  88309. ** If P3>0 then P3 is a register in the root frame of this VDBE that holds 

  88310. ** the largest previously generated record number. No new record numbers are

  88311. ** allowed to be less than this value. When this value reaches its maximum, 

  88312. ** an SQLITE_FULL error is generated. The P3 register is updated with the '

  88313. ** generated record number. This P3 mechanism is used to help implement the

  88314. ** AUTOINCREMENT feature.

  88315. */

  88316. case OP_NewRowid: {           /* out2 */

  88317.   i64 v;                 /* The new rowid */

  88318.   VdbeCursor *pC;        /* Cursor of table to get the new rowid */

  88319.   int res;               /* Result of an sqlite3BtreeLast() */

  88320.   int cnt;               /* Counter to limit the number of searches */

  88321.   Mem *pMem;             /* Register holding largest rowid for AUTOINCREMENT */

  88322.   VdbeFrame *pFrame;     /* Root frame of VDBE */

  88323. 

  88324.   v = 0;

  88325.   res = 0;

  88326.   pOut = out2Prerelease(p, pOp);

  88327.   assert( pOp->p1>=0 && pOp->p1<p->nCursor );

  88328.   pC = p->apCsr[pOp->p1];

  88329.   assert( pC!=0 );

  88330.   assert( pC->isTable );

  88331.   assert( pC->eCurType==CURTYPE_BTREE );

  88332.   assert( pC->uc.pCursor!=0 );

  88333.   {

  88334.     /* The next rowid or record number (different terms for the same

  88335.     ** thing) is obtained in a two-step algorithm.

  88336.     **

  88337.     ** First we attempt to find the largest existing rowid and add one

  88338.     ** to that.  But if the largest existing rowid is already the maximum

  88339.     ** positive integer, we have to fall through to the second

  88340.     ** probabilistic algorithm

  88341.     **

  88342.     ** The second algorithm is to select a rowid at random and see if

  88343.     ** it already exists in the table.  If it does not exist, we have

  88344.     ** succeeded.  If the random rowid does exist, we select a new one

  88345.     ** and try again, up to 100 times.

  88346.     */

  88347.     assert( pC->isTable );

  88348. 

  88349. #ifdef SQLITE_32BIT_ROWID

  88350. #   define MAX_ROWID 0x7fffffff

  88351. #else

  88352.     /* Some compilers complain about constants of the form 0x7fffffffffffffff.

  88353.     ** Others complain about 0x7ffffffffffffffffLL.  The following macro seems

  88354.     ** to provide the constant while making all compilers happy.

  88355.     */

  88356. #   define MAX_ROWID  (i64)( (((u64)0x7fffffff)<<32) | (u64)0xffffffff )

  88357. #endif

  88358. 

  88359.     if( !pC->useRandomRowid ){

  88360.       rc = sqlite3BtreeLast(pC->uc.pCursor, &res);

  88361.       if( rc!=SQLITE_OK ){

  88362.         goto abort_due_to_error;

  88363.       }

  88364.       if( res ){

  88365.         v = 1;   /* IMP: R-61914-48074 */

  88366.       }else{

  88367.         assert( sqlite3BtreeCursorIsValid(pC->uc.pCursor) );

  88368.         v = sqlite3BtreeIntegerKey(pC->uc.pCursor);

  88369.         if( v>=MAX_ROWID ){

  88370.           pC->useRandomRowid = 1;

  88371.         }else{

  88372.           v++;   /* IMP: R-29538-34987 */

  88373.         }

  88374.       }

  88375.     }

  88376. 

  88377. #ifndef SQLITE_OMIT_AUTOINCREMENT

  88378.     if( pOp->p3 ){

  88379.       /* Assert that P3 is a valid memory cell. */

  88380.       assert( pOp->p3>0 );

  88381.       if( p->pFrame ){

  88382.         for(pFrame=p->pFrame; pFrame->pParent; pFrame=pFrame->pParent);

  88383.         /* Assert that P3 is a valid memory cell. */

  88384.         assert( pOp->p3<=pFrame->nMem );

  88385.         pMem = &pFrame->aMem[pOp->p3];

  88386.       }else{

  88387.         /* Assert that P3 is a valid memory cell. */

  88388.         assert( pOp->p3<=(p->nMem+1 - p->nCursor) );

  88389.         pMem = &aMem[pOp->p3];

  88390.         memAboutToChange(p, pMem);

  88391.       }

  88392.       assert( memIsValid(pMem) );

  88393. 

  88394.       REGISTER_TRACE(pOp->p3, pMem);

  88395.       sqlite3VdbeMemIntegerify(pMem);

  88396.       assert( (pMem->flags & MEM_Int)!=0 );  /* mem(P3) holds an integer */

  88397.       if( pMem->u.i==MAX_ROWID || pC->useRandomRowid ){

  88398.         rc = SQLITE_FULL;   /* IMP: R-17817-00630 */

  88399.         goto abort_due_to_error;

  88400.       }

  88401.       if( v<pMem->u.i+1 ){

  88402.         v = pMem->u.i + 1;

  88403.       }

  88404.       pMem->u.i = v;

  88405.     }

  88406. #endif

  88407.     if( pC->useRandomRowid ){

  88408.       /* IMPLEMENTATION-OF: R-07677-41881 If the largest ROWID is equal to the

  88409.       ** largest possible integer (9223372036854775807) then the database

  88410.       ** engine starts picking positive candidate ROWIDs at random until

  88411.       ** it finds one that is not previously used. */

  88412.       assert( pOp->p3==0 );  /* We cannot be in random rowid mode if this is

  88413.                              ** an AUTOINCREMENT table. */

  88414.       cnt = 0;

  88415.       do{

  88416.         sqlite3_randomness(sizeof(v), &v);

  88417.         v &= (MAX_ROWID>>1); v++;  /* Ensure that v is greater than zero */

  88418.       }while(  ((rc = sqlite3BtreeMovetoUnpacked(pC->uc.pCursor, 0, (u64)v,

  88419.                                                  0, &res))==SQLITE_OK)

  88420.             && (res==0)

  88421.             && (++cnt<100));

  88422.       if( rc ) goto abort_due_to_error;

  88423.       if( res==0 ){

  88424.         rc = SQLITE_FULL;   /* IMP: R-38219-53002 */

  88425.         goto abort_due_to_error;

  88426.       }

  88427.       assert( v>0 );  /* EV: R-40812-03570 */

  88428.     }

  88429.     pC->deferredMoveto = 0;

  88430.     pC->cacheStatus = CACHE_STALE;

  88431.   }

  88432.   pOut->u.i = v;

  88433.   break;

  88434. }

  88435. 

  88436. /* Opcode: Insert P1 P2 P3 P4 P5

  88437. ** Synopsis: intkey=r[P3] data=r[P2]

  88438. **

  88439. ** Write an entry into the table of cursor P1.  A new entry is

  88440. ** created if it doesn't already exist or the data for an existing

  88441. ** entry is overwritten.  The data is the value MEM_Blob stored in register

  88442. ** number P2. The key is stored in register P3. The key must

  88443. ** be a MEM_Int.

  88444. **

  88445. ** If the OPFLAG_NCHANGE flag of P5 is set, then the row change count is

  88446. ** incremented (otherwise not).  If the OPFLAG_LASTROWID flag of P5 is set,

  88447. ** then rowid is stored for subsequent return by the

  88448. ** sqlite3_last_insert_rowid() function (otherwise it is unmodified).

  88449. **

  88450. ** If the OPFLAG_USESEEKRESULT flag of P5 is set, the implementation might

  88451. ** run faster by avoiding an unnecessary seek on cursor P1.  However,

  88452. ** the OPFLAG_USESEEKRESULT flag must only be set if there have been no prior

  88453. ** seeks on the cursor or if the most recent seek used a key equal to P3.

  88454. **

  88455. ** If the OPFLAG_ISUPDATE flag is set, then this opcode is part of an

  88456. ** UPDATE operation.  Otherwise (if the flag is clear) then this opcode

  88457. ** is part of an INSERT operation.  The difference is only important to

  88458. ** the update hook.

  88459. **

  88460. ** Parameter P4 may point to a Table structure, or may be NULL. If it is 

  88461. ** not NULL, then the update-hook (sqlite3.xUpdateCallback) is invoked 

  88462. ** following a successful insert.

  88463. **

  88464. ** (WARNING/TODO: If P1 is a pseudo-cursor and P2 is dynamically

  88465. ** allocated, then ownership of P2 is transferred to the pseudo-cursor

  88466. ** and register P2 becomes ephemeral.  If the cursor is changed, the

  88467. ** value of register P2 will then change.  Make sure this does not

  88468. ** cause any problems.)

  88469. **

  88470. ** This instruction only works on tables.  The equivalent instruction

  88471. ** for indices is OP_IdxInsert.

  88472. */

  88473. case OP_Insert: {

  88474.   Mem *pData;       /* MEM cell holding data for the record to be inserted */

  88475.   Mem *pKey;        /* MEM cell holding key  for the record */

  88476.   VdbeCursor *pC;   /* Cursor to table into which insert is written */

  88477.   int seekResult;   /* Result of prior seek or 0 if no USESEEKRESULT flag */

  88478.   const char *zDb;  /* database name - used by the update hook */

  88479.   Table *pTab;      /* Table structure - used by update and pre-update hooks */

  88480.   BtreePayload x;   /* Payload to be inserted */

  88481. 

  88482.   pData = &aMem[pOp->p2];

  88483.   assert( pOp->p1>=0 && pOp->p1<p->nCursor );

  88484.   assert( memIsValid(pData) );

  88485.   pC = p->apCsr[pOp->p1];

  88486.   assert( pC!=0 );

  88487.   assert( pC->eCurType==CURTYPE_BTREE );

  88488.   assert( pC->uc.pCursor!=0 );

  88489.   assert( (pOp->p5 & OPFLAG_ISNOOP) || pC->isTable );

  88490.   assert( pOp->p4type==P4_TABLE || pOp->p4type>=P4_STATIC );

  88491.   REGISTER_TRACE(pOp->p2, pData);

  88492.   sqlite3VdbeIncrWriteCounter(p, pC);

  88493. 

  88494.   pKey = &aMem[pOp->p3];

  88495.   assert( pKey->flags & MEM_Int );

  88496.   assert( memIsValid(pKey) );

  88497.   REGISTER_TRACE(pOp->p3, pKey);

  88498.   x.nKey = pKey->u.i;

  88499. 

  88500.   if( pOp->p4type==P4_TABLE && HAS_UPDATE_HOOK(db) ){

  88501.     assert( pC->iDb>=0 );

  88502.     zDb = db->aDb[pC->iDb].zDbSName;

  88503.     pTab = pOp->p4.pTab;

  88504.     assert( (pOp->p5 & OPFLAG_ISNOOP) || HasRowid(pTab) );

  88505.   }else{

  88506.     pTab = 0;

  88507.     zDb = 0;  /* Not needed.  Silence a compiler warning. */

  88508.   }

  88509. 

  88510. #ifdef SQLITE_ENABLE_PREUPDATE_HOOK

  88511.   /* Invoke the pre-update hook, if any */

  88512.   if( pTab ){

  88513.     if( db->xPreUpdateCallback && !(pOp->p5 & OPFLAG_ISUPDATE) ){

  88514.       sqlite3VdbePreUpdateHook(p, pC, SQLITE_INSERT, zDb, pTab, x.nKey,pOp->p2);

  88515.     }

  88516.     if( db->xUpdateCallback==0 || pTab->aCol==0 ){

  88517.       /* Prevent post-update hook from running in cases when it should not */

  88518.       pTab = 0;

  88519.     }

  88520.   }

  88521.   if( pOp->p5 & OPFLAG_ISNOOP ) break;

  88522. #endif

  88523. 

  88524.   if( pOp->p5 & OPFLAG_NCHANGE ) p->nChange++;

  88525.   if( pOp->p5 & OPFLAG_LASTROWID ) db->lastRowid = x.nKey;

  88526.   assert( pData->flags & (MEM_Blob|MEM_Str) );

  88527.   x.pData = pData->z;

  88528.   x.nData = pData->n;

  88529.   seekResult = ((pOp->p5 & OPFLAG_USESEEKRESULT) ? pC->seekResult : 0);

  88530.   if( pData->flags & MEM_Zero ){

  88531.     x.nZero = pData->u.nZero;

  88532.   }else{

  88533.     x.nZero = 0;

  88534.   }

  88535.   x.pKey = 0;

  88536.   rc = sqlite3BtreeInsert(pC->uc.pCursor, &x,

  88537.       (pOp->p5 & (OPFLAG_APPEND|OPFLAG_SAVEPOSITION)), seekResult

  88538.   );

  88539.   pC->deferredMoveto = 0;

  88540.   pC->cacheStatus = CACHE_STALE;

  88541. 

  88542.   /* Invoke the update-hook if required. */

  88543.   if( rc ) goto abort_due_to_error;

  88544.   if( pTab ){

  88545.     assert( db->xUpdateCallback!=0 );

  88546.     assert( pTab->aCol!=0 );

  88547.     db->xUpdateCallback(db->pUpdateArg,

  88548.            (pOp->p5 & OPFLAG_ISUPDATE) ? SQLITE_UPDATE : SQLITE_INSERT,

  88549.            zDb, pTab->zName, x.nKey);

  88550.   }

  88551.   break;

  88552. }

  88553. 

  88554. /* Opcode: Delete P1 P2 P3 P4 P5

  88555. **

  88556. ** Delete the record at which the P1 cursor is currently pointing.

  88557. **

  88558. ** If the OPFLAG_SAVEPOSITION bit of the P5 parameter is set, then

  88559. ** the cursor will be left pointing at  either the next or the previous

  88560. ** record in the table. If it is left pointing at the next record, then

  88561. ** the next Next instruction will be a no-op. As a result, in this case

  88562. ** it is ok to delete a record from within a Next loop. If 

  88563. ** OPFLAG_SAVEPOSITION bit of P5 is clear, then the cursor will be

  88564. ** left in an undefined state.

  88565. **

  88566. ** If the OPFLAG_AUXDELETE bit is set on P5, that indicates that this

  88567. ** delete one of several associated with deleting a table row and all its

  88568. ** associated index entries.  Exactly one of those deletes is the "primary"

  88569. ** delete.  The others are all on OPFLAG_FORDELETE cursors or else are

  88570. ** marked with the AUXDELETE flag.

  88571. **

  88572. ** If the OPFLAG_NCHANGE flag of P2 (NB: P2 not P5) is set, then the row

  88573. ** change count is incremented (otherwise not).

  88574. **

  88575. ** P1 must not be pseudo-table.  It has to be a real table with

  88576. ** multiple rows.

  88577. **

  88578. ** If P4 is not NULL then it points to a Table object. In this case either 

  88579. ** the update or pre-update hook, or both, may be invoked. The P1 cursor must

  88580. ** have been positioned using OP_NotFound prior to invoking this opcode in 

  88581. ** this case. Specifically, if one is configured, the pre-update hook is 

  88582. ** invoked if P4 is not NULL. The update-hook is invoked if one is configured, 

  88583. ** P4 is not NULL, and the OPFLAG_NCHANGE flag is set in P2.

  88584. **

  88585. ** If the OPFLAG_ISUPDATE flag is set in P2, then P3 contains the address

  88586. ** of the memory cell that contains the value that the rowid of the row will

  88587. ** be set to by the update.

  88588. */

  88589. case OP_Delete: {

  88590.   VdbeCursor *pC;

  88591.   const char *zDb;

  88592.   Table *pTab;

  88593.   int opflags;

  88594. 

  88595.   opflags = pOp->p2;

  88596.   assert( pOp->p1>=0 && pOp->p1<p->nCursor );

  88597.   pC = p->apCsr[pOp->p1];

  88598.   assert( pC!=0 );

  88599.   assert( pC->eCurType==CURTYPE_BTREE );

  88600.   assert( pC->uc.pCursor!=0 );

  88601.   assert( pC->deferredMoveto==0 );

  88602.   sqlite3VdbeIncrWriteCounter(p, pC);

  88603. 

  88604. #ifdef SQLITE_DEBUG

  88605.   if( pOp->p4type==P4_TABLE && HasRowid(pOp->p4.pTab) && pOp->p5==0 ){

  88606.     /* If p5 is zero, the seek operation that positioned the cursor prior to

  88607.     ** OP_Delete will have also set the pC->movetoTarget field to the rowid of

  88608.     ** the row that is being deleted */

  88609.     i64 iKey = sqlite3BtreeIntegerKey(pC->uc.pCursor);

  88610.     assert( CORRUPT_DB || pC->movetoTarget==iKey );

  88611.   }

  88612. #endif

  88613. 

  88614.   /* If the update-hook or pre-update-hook will be invoked, set zDb to

  88615.   ** the name of the db to pass as to it. Also set local pTab to a copy

  88616.   ** of p4.pTab. Finally, if p5 is true, indicating that this cursor was

  88617.   ** last moved with OP_Next or OP_Prev, not Seek or NotFound, set 

  88618.   ** VdbeCursor.movetoTarget to the current rowid.  */

  88619.   if( pOp->p4type==P4_TABLE && HAS_UPDATE_HOOK(db) ){

  88620.     assert( pC->iDb>=0 );

  88621.     assert( pOp->p4.pTab!=0 );

  88622.     zDb = db->aDb[pC->iDb].zDbSName;

  88623.     pTab = pOp->p4.pTab;

  88624.     if( (pOp->p5 & OPFLAG_SAVEPOSITION)!=0 && pC->isTable ){

  88625.       pC->movetoTarget = sqlite3BtreeIntegerKey(pC->uc.pCursor);

  88626.     }

  88627.   }else{

  88628.     zDb = 0;   /* Not needed.  Silence a compiler warning. */

  88629.     pTab = 0;  /* Not needed.  Silence a compiler warning. */

  88630.   }

  88631. 

  88632. #ifdef SQLITE_ENABLE_PREUPDATE_HOOK

  88633.   /* Invoke the pre-update-hook if required. */

  88634.   if( db->xPreUpdateCallback && pOp->p4.pTab ){

  88635.     assert( !(opflags & OPFLAG_ISUPDATE) 

  88636.          || HasRowid(pTab)==0 

  88637.          || (aMem[pOp->p3].flags & MEM_Int) 

  88638.     );

  88639.     sqlite3VdbePreUpdateHook(p, pC,

  88640.         (opflags & OPFLAG_ISUPDATE) ? SQLITE_UPDATE : SQLITE_DELETE, 

  88641.         zDb, pTab, pC->movetoTarget,

  88642.         pOp->p3

  88643.     );

  88644.   }

  88645.   if( opflags & OPFLAG_ISNOOP ) break;

  88646. #endif

  88647.  

  88648.   /* Only flags that can be set are SAVEPOISTION and AUXDELETE */ 

  88649.   assert( (pOp->p5 & ~(OPFLAG_SAVEPOSITION|OPFLAG_AUXDELETE))==0 );

  88650.   assert( OPFLAG_SAVEPOSITION==BTREE_SAVEPOSITION );

  88651.   assert( OPFLAG_AUXDELETE==BTREE_AUXDELETE );

  88652. 

  88653. #ifdef SQLITE_DEBUG

  88654.   if( p->pFrame==0 ){

  88655.     if( pC->isEphemeral==0

  88656.         && (pOp->p5 & OPFLAG_AUXDELETE)==0

  88657.         && (pC->wrFlag & OPFLAG_FORDELETE)==0

  88658.       ){

  88659.       nExtraDelete++;

  88660.     }

  88661.     if( pOp->p2 & OPFLAG_NCHANGE ){

  88662.       nExtraDelete--;

  88663.     }

  88664.   }

  88665. #endif

  88666. 

  88667.   rc = sqlite3BtreeDelete(pC->uc.pCursor, pOp->p5);

  88668.   pC->cacheStatus = CACHE_STALE;

  88669.   pC->seekResult = 0;

  88670.   if( rc ) goto abort_due_to_error;

  88671. 

  88672.   /* Invoke the update-hook if required. */

  88673.   if( opflags & OPFLAG_NCHANGE ){

  88674.     p->nChange++;

  88675.     if( db->xUpdateCallback && HasRowid(pTab) ){

  88676.       db->xUpdateCallback(db->pUpdateArg, SQLITE_DELETE, zDb, pTab->zName,

  88677.           pC->movetoTarget);

  88678.       assert( pC->iDb>=0 );

  88679.     }

  88680.   }

  88681. 

  88682.   break;

  88683. }

  88684. /* Opcode: ResetCount * * * * *

  88685. **

  88686. ** The value of the change counter is copied to the database handle

  88687. ** change counter (returned by subsequent calls to sqlite3_changes()).

  88688. ** Then the VMs internal change counter resets to 0.

  88689. ** This is used by trigger programs.

  88690. */

  88691. case OP_ResetCount: {

  88692.   sqlite3VdbeSetChanges(db, p->nChange);

  88693.   p->nChange = 0;

  88694.   break;

  88695. }

  88696. 

  88697. /* Opcode: SorterCompare P1 P2 P3 P4

  88698. ** Synopsis: if key(P1)!=trim(r[P3],P4) goto P2

  88699. **

  88700. ** P1 is a sorter cursor. This instruction compares a prefix of the

  88701. ** record blob in register P3 against a prefix of the entry that 

  88702. ** the sorter cursor currently points to.  Only the first P4 fields

  88703. ** of r[P3] and the sorter record are compared.

  88704. **

  88705. ** If either P3 or the sorter contains a NULL in one of their significant

  88706. ** fields (not counting the P4 fields at the end which are ignored) then

  88707. ** the comparison is assumed to be equal.

  88708. **

  88709. ** Fall through to next instruction if the two records compare equal to

  88710. ** each other.  Jump to P2 if they are different.

  88711. */

  88712. case OP_SorterCompare: {

  88713.   VdbeCursor *pC;

  88714.   int res;

  88715.   int nKeyCol;

  88716. 

  88717.   pC = p->apCsr[pOp->p1];

  88718.   assert( isSorter(pC) );

  88719.   assert( pOp->p4type==P4_INT32 );

  88720.   pIn3 = &aMem[pOp->p3];

  88721.   nKeyCol = pOp->p4.i;

  88722.   res = 0;

  88723.   rc = sqlite3VdbeSorterCompare(pC, pIn3, nKeyCol, &res);

  88724.   VdbeBranchTaken(res!=0,2);

  88725.   if( rc ) goto abort_due_to_error;

  88726.   if( res ) goto jump_to_p2;

  88727.   break;

  88728. };

  88729. 

  88730. /* Opcode: SorterData P1 P2 P3 * *

  88731. ** Synopsis: r[P2]=data

  88732. **

  88733. ** Write into register P2 the current sorter data for sorter cursor P1.

  88734. ** Then clear the column header cache on cursor P3.

  88735. **

  88736. ** This opcode is normally use to move a record out of the sorter and into

  88737. ** a register that is the source for a pseudo-table cursor created using

  88738. ** OpenPseudo.  That pseudo-table cursor is the one that is identified by

  88739. ** parameter P3.  Clearing the P3 column cache as part of this opcode saves

  88740. ** us from having to issue a separate NullRow instruction to clear that cache.

  88741. */

  88742. case OP_SorterData: {

  88743.   VdbeCursor *pC;

  88744. 

  88745.   pOut = &aMem[pOp->p2];

  88746.   pC = p->apCsr[pOp->p1];

  88747.   assert( isSorter(pC) );

  88748.   rc = sqlite3VdbeSorterRowkey(pC, pOut);

  88749.   assert( rc!=SQLITE_OK || (pOut->flags & MEM_Blob) );

  88750.   assert( pOp->p1>=0 && pOp->p1<p->nCursor );

  88751.   if( rc ) goto abort_due_to_error;

  88752.   p->apCsr[pOp->p3]->cacheStatus = CACHE_STALE;

  88753.   break;

  88754. }

  88755. 

  88756. /* Opcode: RowData P1 P2 P3 * *

  88757. ** Synopsis: r[P2]=data

  88758. **

  88759. ** Write into register P2 the complete row content for the row at 

  88760. ** which cursor P1 is currently pointing.

  88761. ** There is no interpretation of the data.  

  88762. ** It is just copied onto the P2 register exactly as 

  88763. ** it is found in the database file.

  88764. **

  88765. ** If cursor P1 is an index, then the content is the key of the row.

  88766. ** If cursor P2 is a table, then the content extracted is the data.

  88767. **

  88768. ** If the P1 cursor must be pointing to a valid row (not a NULL row)

  88769. ** of a real table, not a pseudo-table.

  88770. **

  88771. ** If P3!=0 then this opcode is allowed to make an ephemeral pointer

  88772. ** into the database page.  That means that the content of the output

  88773. ** register will be invalidated as soon as the cursor moves - including

  88774. ** moves caused by other cursors that "save" the current cursors

  88775. ** position in order that they can write to the same table.  If P3==0

  88776. ** then a copy of the data is made into memory.  P3!=0 is faster, but

  88777. ** P3==0 is safer.

  88778. **

  88779. ** If P3!=0 then the content of the P2 register is unsuitable for use

  88780. ** in OP_Result and any OP_Result will invalidate the P2 register content.

  88781. ** The P2 register content is invalidated by opcodes like OP_Function or

  88782. ** by any use of another cursor pointing to the same table.

  88783. */

  88784. case OP_RowData: {

  88785.   VdbeCursor *pC;

  88786.   BtCursor *pCrsr;

  88787.   u32 n;

  88788. 

  88789.   pOut = out2Prerelease(p, pOp);

  88790. 

  88791.   assert( pOp->p1>=0 && pOp->p1<p->nCursor );

  88792.   pC = p->apCsr[pOp->p1];

  88793.   assert( pC!=0 );

  88794.   assert( pC->eCurType==CURTYPE_BTREE );

  88795.   assert( isSorter(pC)==0 );

  88796.   assert( pC->nullRow==0 );

  88797.   assert( pC->uc.pCursor!=0 );

  88798.   pCrsr = pC->uc.pCursor;

  88799. 

  88800.   /* The OP_RowData opcodes always follow OP_NotExists or

  88801.   ** OP_SeekRowid or OP_Rewind/Op_Next with no intervening instructions

  88802.   ** that might invalidate the cursor.

  88803.   ** If this where not the case, on of the following assert()s

  88804.   ** would fail.  Should this ever change (because of changes in the code

  88805.   ** generator) then the fix would be to insert a call to

  88806.   ** sqlite3VdbeCursorMoveto().

  88807.   */

  88808.   assert( pC->deferredMoveto==0 );

  88809.   assert( sqlite3BtreeCursorIsValid(pCrsr) );

  88810. #if 0  /* Not required due to the previous to assert() statements */

  88811.   rc = sqlite3VdbeCursorMoveto(pC);

  88812.   if( rc!=SQLITE_OK ) goto abort_due_to_error;

  88813. #endif

  88814. 

  88815.   n = sqlite3BtreePayloadSize(pCrsr);

  88816.   if( n>(u32)db->aLimit[SQLITE_LIMIT_LENGTH] ){

  88817.     goto too_big;

  88818.   }

  88819.   testcase( n==0 );

  88820.   rc = sqlite3VdbeMemFromBtree(pCrsr, 0, n, pOut);

  88821.   if( rc ) goto abort_due_to_error;

  88822.   if( !pOp->p3 ) Deephemeralize(pOut);

  88823.   UPDATE_MAX_BLOBSIZE(pOut);

  88824.   REGISTER_TRACE(pOp->p2, pOut);

  88825.   break;

  88826. }

  88827. 

  88828. /* Opcode: Rowid P1 P2 * * *

  88829. ** Synopsis: r[P2]=rowid

  88830. **

  88831. ** Store in register P2 an integer which is the key of the table entry that

  88832. ** P1 is currently point to.

  88833. **

  88834. ** P1 can be either an ordinary table or a virtual table.  There used to

  88835. ** be a separate OP_VRowid opcode for use with virtual tables, but this

  88836. ** one opcode now works for both table types.

  88837. */

  88838. case OP_Rowid: {                 /* out2 */

  88839.   VdbeCursor *pC;

  88840.   i64 v;

  88841.   sqlite3_vtab *pVtab;

  88842.   const sqlite3_module *pModule;

  88843. 

  88844.   pOut = out2Prerelease(p, pOp);

  88845.   assert( pOp->p1>=0 && pOp->p1<p->nCursor );

  88846.   pC = p->apCsr[pOp->p1];

  88847.   assert( pC!=0 );

  88848.   assert( pC->eCurType!=CURTYPE_PSEUDO || pC->nullRow );

  88849.   if( pC->nullRow ){

  88850.     pOut->flags = MEM_Null;

  88851.     break;

  88852.   }else if( pC->deferredMoveto ){

  88853.     v = pC->movetoTarget;

  88854. #ifndef SQLITE_OMIT_VIRTUALTABLE

  88855.   }else if( pC->eCurType==CURTYPE_VTAB ){

  88856.     assert( pC->uc.pVCur!=0 );

  88857.     pVtab = pC->uc.pVCur->pVtab;

  88858.     pModule = pVtab->pModule;

  88859.     assert( pModule->xRowid );

  88860.     rc = pModule->xRowid(pC->uc.pVCur, &v);

  88861.     sqlite3VtabImportErrmsg(p, pVtab);

  88862.     if( rc ) goto abort_due_to_error;

  88863. #endif /* SQLITE_OMIT_VIRTUALTABLE */

  88864.   }else{

  88865.     assert( pC->eCurType==CURTYPE_BTREE );

  88866.     assert( pC->uc.pCursor!=0 );

  88867.     rc = sqlite3VdbeCursorRestore(pC);

  88868.     if( rc ) goto abort_due_to_error;

  88869.     if( pC->nullRow ){

  88870.       pOut->flags = MEM_Null;

  88871.       break;

  88872.     }

  88873.     v = sqlite3BtreeIntegerKey(pC->uc.pCursor);

  88874.   }

  88875.   pOut->u.i = v;

  88876.   break;

  88877. }

  88878. 

  88879. /* Opcode: NullRow P1 * * * *

  88880. **

  88881. ** Move the cursor P1 to a null row.  Any OP_Column operations

  88882. ** that occur while the cursor is on the null row will always

  88883. ** write a NULL.

  88884. */

  88885. case OP_NullRow: {

  88886.   VdbeCursor *pC;

  88887. 

  88888.   assert( pOp->p1>=0 && pOp->p1<p->nCursor );

  88889.   pC = p->apCsr[pOp->p1];

  88890.   assert( pC!=0 );

  88891.   pC->nullRow = 1;

  88892.   pC->cacheStatus = CACHE_STALE;

  88893.   if( pC->eCurType==CURTYPE_BTREE ){

  88894.     assert( pC->uc.pCursor!=0 );

  88895.     sqlite3BtreeClearCursor(pC->uc.pCursor);

  88896.   }

  88897. #ifdef SQLITE_DEBUG

  88898.   if( pC->seekOp==0 ) pC->seekOp = OP_NullRow;

  88899. #endif

  88900.   break;

  88901. }

  88902. 

  88903. /* Opcode: SeekEnd P1 * * * *

  88904. **

  88905. ** Position cursor P1 at the end of the btree for the purpose of

  88906. ** appending a new entry onto the btree.

  88907. **

  88908. ** It is assumed that the cursor is used only for appending and so

  88909. ** if the cursor is valid, then the cursor must already be pointing

  88910. ** at the end of the btree and so no changes are made to

  88911. ** the cursor.

  88912. */

  88913. /* Opcode: Last P1 P2 * * *

  88914. **

  88915. ** The next use of the Rowid or Column or Prev instruction for P1 

  88916. ** will refer to the last entry in the database table or index.

  88917. ** If the table or index is empty and P2>0, then jump immediately to P2.

  88918. ** If P2 is 0 or if the table or index is not empty, fall through

  88919. ** to the following instruction.

  88920. **

  88921. ** This opcode leaves the cursor configured to move in reverse order,

  88922. ** from the end toward the beginning.  In other words, the cursor is

  88923. ** configured to use Prev, not Next.

  88924. */

  88925. case OP_SeekEnd:

  88926. case OP_Last: {        /* jump */

  88927.   VdbeCursor *pC;

  88928.   BtCursor *pCrsr;

  88929.   int res;

  88930. 

  88931.   assert( pOp->p1>=0 && pOp->p1<p->nCursor );

  88932.   pC = p->apCsr[pOp->p1];

  88933.   assert( pC!=0 );

  88934.   assert( pC->eCurType==CURTYPE_BTREE );

  88935.   pCrsr = pC->uc.pCursor;

  88936.   res = 0;

  88937.   assert( pCrsr!=0 );

  88938. #ifdef SQLITE_DEBUG

  88939.   pC->seekOp = pOp->opcode;

  88940. #endif

  88941.   if( pOp->opcode==OP_SeekEnd ){

  88942.     assert( pOp->p2==0 );

  88943.     pC->seekResult = -1;

  88944.     if( sqlite3BtreeCursorIsValidNN(pCrsr) ){

  88945.       break;

  88946.     }

  88947.   }

  88948.   rc = sqlite3BtreeLast(pCrsr, &res);

  88949.   pC->nullRow = (u8)res;

  88950.   pC->deferredMoveto = 0;

  88951.   pC->cacheStatus = CACHE_STALE;

  88952.   if( rc ) goto abort_due_to_error;

  88953.   if( pOp->p2>0 ){

  88954.     VdbeBranchTaken(res!=0,2);

  88955.     if( res ) goto jump_to_p2;

  88956.   }

  88957.   break;

  88958. }

  88959. 

  88960. /* Opcode: IfSmaller P1 P2 P3 * *

  88961. **

  88962. ** Estimate the number of rows in the table P1.  Jump to P2 if that

  88963. ** estimate is less than approximately 2**(0.1*P3).

  88964. */

  88965. case OP_IfSmaller: {        /* jump */

  88966.   VdbeCursor *pC;

  88967.   BtCursor *pCrsr;

  88968.   int res;

  88969.   i64 sz;

  88970. 

  88971.   assert( pOp->p1>=0 && pOp->p1<p->nCursor );

  88972.   pC = p->apCsr[pOp->p1];

  88973.   assert( pC!=0 );

  88974.   pCrsr = pC->uc.pCursor;

  88975.   assert( pCrsr );

  88976.   rc = sqlite3BtreeFirst(pCrsr, &res);

  88977.   if( rc ) goto abort_due_to_error;

  88978.   if( res==0 ){

  88979.     sz = sqlite3BtreeRowCountEst(pCrsr);

  88980.     if( ALWAYS(sz>=0) && sqlite3LogEst((u64)sz)<pOp->p3 ) res = 1;

  88981.   }

  88982.   VdbeBranchTaken(res!=0,2);

  88983.   if( res ) goto jump_to_p2;

  88984.   break;

  88985. }

  88986. 

  88987. 

  88988. /* Opcode: SorterSort P1 P2 * * *

  88989. **

  88990. ** After all records have been inserted into the Sorter object

  88991. ** identified by P1, invoke this opcode to actually do the sorting.

  88992. ** Jump to P2 if there are no records to be sorted.

  88993. **

  88994. ** This opcode is an alias for OP_Sort and OP_Rewind that is used

  88995. ** for Sorter objects.

  88996. */

  88997. /* Opcode: Sort P1 P2 * * *

  88998. **

  88999. ** This opcode does exactly the same thing as OP_Rewind except that

  89000. ** it increments an undocumented global variable used for testing.

  89001. **

  89002. ** Sorting is accomplished by writing records into a sorting index,

  89003. ** then rewinding that index and playing it back from beginning to

  89004. ** end.  We use the OP_Sort opcode instead of OP_Rewind to do the

  89005. ** rewinding so that the global variable will be incremented and

  89006. ** regression tests can determine whether or not the optimizer is

  89007. ** correctly optimizing out sorts.

  89008. */

  89009. case OP_SorterSort:    /* jump */

  89010. case OP_Sort: {        /* jump */

  89011. #ifdef SQLITE_TEST

  89012.   sqlite3_sort_count++;

  89013.   sqlite3_search_count--;

  89014. #endif

  89015.   p->aCounter[SQLITE_STMTSTATUS_SORT]++;

  89016.   /* Fall through into OP_Rewind */

  89017. }

  89018. /* Opcode: Rewind P1 P2 * * *

  89019. **

  89020. ** The next use of the Rowid or Column or Next instruction for P1 

  89021. ** will refer to the first entry in the database table or index.

  89022. ** If the table or index is empty, jump immediately to P2.

  89023. ** If the table or index is not empty, fall through to the following 

  89024. ** instruction.

  89025. **

  89026. ** This opcode leaves the cursor configured to move in forward order,

  89027. ** from the beginning toward the end.  In other words, the cursor is

  89028. ** configured to use Next, not Prev.

  89029. */

  89030. case OP_Rewind: {        /* jump */

  89031.   VdbeCursor *pC;

  89032.   BtCursor *pCrsr;

  89033.   int res;

  89034. 

  89035.   assert( pOp->p1>=0 && pOp->p1<p->nCursor );

  89036.   assert( pOp->p5==0 );

  89037.   pC = p->apCsr[pOp->p1];

  89038.   assert( pC!=0 );

  89039.   assert( isSorter(pC)==(pOp->opcode==OP_SorterSort) );

  89040.   res = 1;

  89041. #ifdef SQLITE_DEBUG

  89042.   pC->seekOp = OP_Rewind;

  89043. #endif

  89044.   if( isSorter(pC) ){

  89045.     rc = sqlite3VdbeSorterRewind(pC, &res);

  89046.   }else{

  89047.     assert( pC->eCurType==CURTYPE_BTREE );

  89048.     pCrsr = pC->uc.pCursor;

  89049.     assert( pCrsr );

  89050.     rc = sqlite3BtreeFirst(pCrsr, &res);

  89051.     pC->deferredMoveto = 0;

  89052.     pC->cacheStatus = CACHE_STALE;

  89053.   }

  89054.   if( rc ) goto abort_due_to_error;

  89055.   pC->nullRow = (u8)res;

  89056.   assert( pOp->p2>0 && pOp->p2<p->nOp );

  89057.   VdbeBranchTaken(res!=0,2);

  89058.   if( res ) goto jump_to_p2;

  89059.   break;

  89060. }

  89061. 

  89062. /* Opcode: Next P1 P2 P3 P4 P5

  89063. **

  89064. ** Advance cursor P1 so that it points to the next key/data pair in its

  89065. ** table or index.  If there are no more key/value pairs then fall through

  89066. ** to the following instruction.  But if the cursor advance was successful,

  89067. ** jump immediately to P2.

  89068. **

  89069. ** The Next opcode is only valid following an SeekGT, SeekGE, or

  89070. ** OP_Rewind opcode used to position the cursor.  Next is not allowed

  89071. ** to follow SeekLT, SeekLE, or OP_Last.

  89072. **

  89073. ** The P1 cursor must be for a real table, not a pseudo-table.  P1 must have

  89074. ** been opened prior to this opcode or the program will segfault.

  89075. **

  89076. ** The P3 value is a hint to the btree implementation. If P3==1, that

  89077. ** means P1 is an SQL index and that this instruction could have been

  89078. ** omitted if that index had been unique.  P3 is usually 0.  P3 is

  89079. ** always either 0 or 1.

  89080. **

  89081. ** P4 is always of type P4_ADVANCE. The function pointer points to

  89082. ** sqlite3BtreeNext().

  89083. **

  89084. ** If P5 is positive and the jump is taken, then event counter

  89085. ** number P5-1 in the prepared statement is incremented.

  89086. **

  89087. ** See also: Prev

  89088. */

  89089. /* Opcode: Prev P1 P2 P3 P4 P5

  89090. **

  89091. ** Back up cursor P1 so that it points to the previous key/data pair in its

  89092. ** table or index.  If there is no previous key/value pairs then fall through

  89093. ** to the following instruction.  But if the cursor backup was successful,

  89094. ** jump immediately to P2.

  89095. **

  89096. **

  89097. ** The Prev opcode is only valid following an SeekLT, SeekLE, or

  89098. ** OP_Last opcode used to position the cursor.  Prev is not allowed

  89099. ** to follow SeekGT, SeekGE, or OP_Rewind.

  89100. **

  89101. ** The P1 cursor must be for a real table, not a pseudo-table.  If P1 is

  89102. ** not open then the behavior is undefined.

  89103. **

  89104. ** The P3 value is a hint to the btree implementation. If P3==1, that

  89105. ** means P1 is an SQL index and that this instruction could have been

  89106. ** omitted if that index had been unique.  P3 is usually 0.  P3 is

  89107. ** always either 0 or 1.

  89108. **

  89109. ** P4 is always of type P4_ADVANCE. The function pointer points to

  89110. ** sqlite3BtreePrevious().

  89111. **

  89112. ** If P5 is positive and the jump is taken, then event counter

  89113. ** number P5-1 in the prepared statement is incremented.

  89114. */

  89115. /* Opcode: SorterNext P1 P2 * * P5

  89116. **

  89117. ** This opcode works just like OP_Next except that P1 must be a

  89118. ** sorter object for which the OP_SorterSort opcode has been

  89119. ** invoked.  This opcode advances the cursor to the next sorted

  89120. ** record, or jumps to P2 if there are no more sorted records.

  89121. */

  89122. case OP_SorterNext: {  /* jump */

  89123.   VdbeCursor *pC;

  89124. 

  89125.   pC = p->apCsr[pOp->p1];

  89126.   assert( isSorter(pC) );

  89127.   rc = sqlite3VdbeSorterNext(db, pC);

  89128.   goto next_tail;

  89129. case OP_Prev:          /* jump */

  89130. case OP_Next:          /* jump */

  89131.   assert( pOp->p1>=0 && pOp->p1<p->nCursor );

  89132.   assert( pOp->p5<ArraySize(p->aCounter) );

  89133.   pC = p->apCsr[pOp->p1];

  89134.   assert( pC!=0 );

  89135.   assert( pC->deferredMoveto==0 );

  89136.   assert( pC->eCurType==CURTYPE_BTREE );

  89137.   assert( pOp->opcode!=OP_Next || pOp->p4.xAdvance==sqlite3BtreeNext );

  89138.   assert( pOp->opcode!=OP_Prev || pOp->p4.xAdvance==sqlite3BtreePrevious );

  89139. 

  89140.   /* The Next opcode is only used after SeekGT, SeekGE, Rewind, and Found.

  89141.   ** The Prev opcode is only used after SeekLT, SeekLE, and Last. */

  89142.   assert( pOp->opcode!=OP_Next

  89143.        || pC->seekOp==OP_SeekGT || pC->seekOp==OP_SeekGE

  89144.        || pC->seekOp==OP_Rewind || pC->seekOp==OP_Found 

  89145.        || pC->seekOp==OP_NullRow|| pC->seekOp==OP_SeekRowid);

  89146.   assert( pOp->opcode!=OP_Prev

  89147.        || pC->seekOp==OP_SeekLT || pC->seekOp==OP_SeekLE

  89148.        || pC->seekOp==OP_Last 

  89149.        || pC->seekOp==OP_NullRow);

  89150. 

  89151.   rc = pOp->p4.xAdvance(pC->uc.pCursor, pOp->p3);

  89152. next_tail:

  89153.   pC->cacheStatus = CACHE_STALE;

  89154.   VdbeBranchTaken(rc==SQLITE_OK,2);

  89155.   if( rc==SQLITE_OK ){

  89156.     pC->nullRow = 0;

  89157.     p->aCounter[pOp->p5]++;

  89158. #ifdef SQLITE_TEST

  89159.     sqlite3_search_count++;

  89160. #endif

  89161.     goto jump_to_p2_and_check_for_interrupt;

  89162.   }

  89163.   if( rc!=SQLITE_DONE ) goto abort_due_to_error;

  89164.   rc = SQLITE_OK;

  89165.   pC->nullRow = 1;

  89166.   goto check_for_interrupt;

  89167. }

  89168. 

  89169. /* Opcode: IdxInsert P1 P2 P3 P4 P5

  89170. ** Synopsis: key=r[P2]

  89171. **

  89172. ** Register P2 holds an SQL index key made using the

  89173. ** MakeRecord instructions.  This opcode writes that key

  89174. ** into the index P1.  Data for the entry is nil.

  89175. **

  89176. ** If P4 is not zero, then it is the number of values in the unpacked

  89177. ** key of reg(P2).  In that case, P3 is the index of the first register

  89178. ** for the unpacked key.  The availability of the unpacked key can sometimes

  89179. ** be an optimization.

  89180. **

  89181. ** If P5 has the OPFLAG_APPEND bit set, that is a hint to the b-tree layer

  89182. ** that this insert is likely to be an append.

  89183. **

  89184. ** If P5 has the OPFLAG_NCHANGE bit set, then the change counter is

  89185. ** incremented by this instruction.  If the OPFLAG_NCHANGE bit is clear,

  89186. ** then the change counter is unchanged.

  89187. **

  89188. ** If the OPFLAG_USESEEKRESULT flag of P5 is set, the implementation might

  89189. ** run faster by avoiding an unnecessary seek on cursor P1.  However,

  89190. ** the OPFLAG_USESEEKRESULT flag must only be set if there have been no prior

  89191. ** seeks on the cursor or if the most recent seek used a key equivalent

  89192. ** to P2. 

  89193. **

  89194. ** This instruction only works for indices.  The equivalent instruction

  89195. ** for tables is OP_Insert.

  89196. */

  89197. /* Opcode: SorterInsert P1 P2 * * *

  89198. ** Synopsis: key=r[P2]

  89199. **

  89200. ** Register P2 holds an SQL index key made using the

  89201. ** MakeRecord instructions.  This opcode writes that key

  89202. ** into the sorter P1.  Data for the entry is nil.

  89203. */

  89204. case OP_SorterInsert:       /* in2 */

  89205. case OP_IdxInsert: {        /* in2 */

  89206.   VdbeCursor *pC;

  89207.   BtreePayload x;

  89208. 

  89209.   assert( pOp->p1>=0 && pOp->p1<p->nCursor );

  89210.   pC = p->apCsr[pOp->p1];

  89211.   sqlite3VdbeIncrWriteCounter(p, pC);

  89212.   assert( pC!=0 );

  89213.   assert( isSorter(pC)==(pOp->opcode==OP_SorterInsert) );

  89214.   pIn2 = &aMem[pOp->p2];

  89215.   assert( pIn2->flags & MEM_Blob );

  89216.   if( pOp->p5 & OPFLAG_NCHANGE ) p->nChange++;

  89217.   assert( pC->eCurType==CURTYPE_BTREE || pOp->opcode==OP_SorterInsert );

  89218.   assert( pC->isTable==0 );

  89219.   rc = ExpandBlob(pIn2);

  89220.   if( rc ) goto abort_due_to_error;

  89221.   if( pOp->opcode==OP_SorterInsert ){

  89222.     rc = sqlite3VdbeSorterWrite(pC, pIn2);

  89223.   }else{

  89224.     x.nKey = pIn2->n;

  89225.     x.pKey = pIn2->z;

  89226.     x.aMem = aMem + pOp->p3;

  89227.     x.nMem = (u16)pOp->p4.i;

  89228.     rc = sqlite3BtreeInsert(pC->uc.pCursor, &x,

  89229.          (pOp->p5 & (OPFLAG_APPEND|OPFLAG_SAVEPOSITION)), 

  89230.         ((pOp->p5 & OPFLAG_USESEEKRESULT) ? pC->seekResult : 0)

  89231.         );

  89232.     assert( pC->deferredMoveto==0 );

  89233.     pC->cacheStatus = CACHE_STALE;

  89234.   }

  89235.   if( rc) goto abort_due_to_error;

  89236.   break;

  89237. }

  89238. 

  89239. /* Opcode: IdxDelete P1 P2 P3 * *

  89240. ** Synopsis: key=r[P2@P3]

  89241. **

  89242. ** The content of P3 registers starting at register P2 form

  89243. ** an unpacked index key. This opcode removes that entry from the 

  89244. ** index opened by cursor P1.

  89245. */

  89246. case OP_IdxDelete: {

  89247.   VdbeCursor *pC;

  89248.   BtCursor *pCrsr;

  89249.   int res;

  89250.   UnpackedRecord r;

  89251. 

  89252.   assert( pOp->p3>0 );

  89253.   assert( pOp->p2>0 && pOp->p2+pOp->p3<=(p->nMem+1 - p->nCursor)+1 );

  89254.   assert( pOp->p1>=0 && pOp->p1<p->nCursor );

  89255.   pC = p->apCsr[pOp->p1];

  89256.   assert( pC!=0 );

  89257.   assert( pC->eCurType==CURTYPE_BTREE );

  89258.   sqlite3VdbeIncrWriteCounter(p, pC);

  89259.   pCrsr = pC->uc.pCursor;

  89260.   assert( pCrsr!=0 );

  89261.   assert( pOp->p5==0 );

  89262.   r.pKeyInfo = pC->pKeyInfo;

  89263.   r.nField = (u16)pOp->p3;

  89264.   r.default_rc = 0;

  89265.   r.aMem = &aMem[pOp->p2];

  89266.   rc = sqlite3BtreeMovetoUnpacked(pCrsr, &r, 0, 0, &res);

  89267.   if( rc ) goto abort_due_to_error;

  89268.   if( res==0 ){

  89269.     rc = sqlite3BtreeDelete(pCrsr, BTREE_AUXDELETE);

  89270.     if( rc ) goto abort_due_to_error;

  89271.   }

  89272.   assert( pC->deferredMoveto==0 );

  89273.   pC->cacheStatus = CACHE_STALE;

  89274.   pC->seekResult = 0;

  89275.   break;

  89276. }

  89277. 

  89278. /* Opcode: DeferredSeek P1 * P3 P4 *

  89279. ** Synopsis: Move P3 to P1.rowid if needed

  89280. **

  89281. ** P1 is an open index cursor and P3 is a cursor on the corresponding

  89282. ** table.  This opcode does a deferred seek of the P3 table cursor

  89283. ** to the row that corresponds to the current row of P1.

  89284. **

  89285. ** This is a deferred seek.  Nothing actually happens until

  89286. ** the cursor is used to read a record.  That way, if no reads

  89287. ** occur, no unnecessary I/O happens.

  89288. **

  89289. ** P4 may be an array of integers (type P4_INTARRAY) containing

  89290. ** one entry for each column in the P3 table.  If array entry a(i)

  89291. ** is non-zero, then reading column a(i)-1 from cursor P3 is 

  89292. ** equivalent to performing the deferred seek and then reading column i 

  89293. ** from P1.  This information is stored in P3 and used to redirect

  89294. ** reads against P3 over to P1, thus possibly avoiding the need to

  89295. ** seek and read cursor P3.

  89296. */

  89297. /* Opcode: IdxRowid P1 P2 * * *

  89298. ** Synopsis: r[P2]=rowid

  89299. **

  89300. ** Write into register P2 an integer which is the last entry in the record at

  89301. ** the end of the index key pointed to by cursor P1.  This integer should be

  89302. ** the rowid of the table entry to which this index entry points.

  89303. **

  89304. ** See also: Rowid, MakeRecord.

  89305. */

  89306. case OP_DeferredSeek:

  89307. case OP_IdxRowid: {           /* out2 */

  89308.   VdbeCursor *pC;             /* The P1 index cursor */

  89309.   VdbeCursor *pTabCur;        /* The P2 table cursor (OP_DeferredSeek only) */

  89310.   i64 rowid;                  /* Rowid that P1 current points to */

  89311. 

  89312.   assert( pOp->p1>=0 && pOp->p1<p->nCursor );

  89313.   pC = p->apCsr[pOp->p1];

  89314.   assert( pC!=0 );

  89315.   assert( pC->eCurType==CURTYPE_BTREE );

  89316.   assert( pC->uc.pCursor!=0 );

  89317.   assert( pC->isTable==0 );

  89318.   assert( pC->deferredMoveto==0 );

  89319.   assert( !pC->nullRow || pOp->opcode==OP_IdxRowid );

  89320. 

  89321.   /* The IdxRowid and Seek opcodes are combined because of the commonality

  89322.   ** of sqlite3VdbeCursorRestore() and sqlite3VdbeIdxRowid(). */

  89323.   rc = sqlite3VdbeCursorRestore(pC);

  89324. 

  89325.   /* sqlite3VbeCursorRestore() can only fail if the record has been deleted

  89326.   ** out from under the cursor.  That will never happens for an IdxRowid

  89327.   ** or Seek opcode */

  89328.   if( NEVER(rc!=SQLITE_OK) ) goto abort_due_to_error;

  89329. 

  89330.   if( !pC->nullRow ){

  89331.     rowid = 0;  /* Not needed.  Only used to silence a warning. */

  89332.     rc = sqlite3VdbeIdxRowid(db, pC->uc.pCursor, &rowid);

  89333.     if( rc!=SQLITE_OK ){

  89334.       goto abort_due_to_error;

  89335.     }

  89336.     if( pOp->opcode==OP_DeferredSeek ){

  89337.       assert( pOp->p3>=0 && pOp->p3<p->nCursor );

  89338.       pTabCur = p->apCsr[pOp->p3];

  89339.       assert( pTabCur!=0 );

  89340.       assert( pTabCur->eCurType==CURTYPE_BTREE );

  89341.       assert( pTabCur->uc.pCursor!=0 );

  89342.       assert( pTabCur->isTable );

  89343.       pTabCur->nullRow = 0;

  89344.       pTabCur->movetoTarget = rowid;

  89345.       pTabCur->deferredMoveto = 1;

  89346.       assert( pOp->p4type==P4_INTARRAY || pOp->p4.ai==0 );

  89347.       pTabCur->aAltMap = pOp->p4.ai;

  89348.       pTabCur->pAltCursor = pC;

  89349.     }else{

  89350.       pOut = out2Prerelease(p, pOp);

  89351.       pOut->u.i = rowid;

  89352.     }

  89353.   }else{

  89354.     assert( pOp->opcode==OP_IdxRowid );

  89355.     sqlite3VdbeMemSetNull(&aMem[pOp->p2]);

  89356.   }

  89357.   break;

  89358. }

  89359. 

  89360. /* Opcode: IdxGE P1 P2 P3 P4 P5

  89361. ** Synopsis: key=r[P3@P4]

  89362. **

  89363. ** The P4 register values beginning with P3 form an unpacked index 

  89364. ** key that omits the PRIMARY KEY.  Compare this key value against the index 

  89365. ** that P1 is currently pointing to, ignoring the PRIMARY KEY or ROWID 

  89366. ** fields at the end.

  89367. **

  89368. ** If the P1 index entry is greater than or equal to the key value

  89369. ** then jump to P2.  Otherwise fall through to the next instruction.

  89370. */

  89371. /* Opcode: IdxGT P1 P2 P3 P4 P5

  89372. ** Synopsis: key=r[P3@P4]

  89373. **

  89374. ** The P4 register values beginning with P3 form an unpacked index 

  89375. ** key that omits the PRIMARY KEY.  Compare this key value against the index 

  89376. ** that P1 is currently pointing to, ignoring the PRIMARY KEY or ROWID 

  89377. ** fields at the end.

  89378. **

  89379. ** If the P1 index entry is greater than the key value

  89380. ** then jump to P2.  Otherwise fall through to the next instruction.

  89381. */

  89382. /* Opcode: IdxLT P1 P2 P3 P4 P5

  89383. ** Synopsis: key=r[P3@P4]

  89384. **

  89385. ** The P4 register values beginning with P3 form an unpacked index 

  89386. ** key that omits the PRIMARY KEY or ROWID.  Compare this key value against

  89387. ** the index that P1 is currently pointing to, ignoring the PRIMARY KEY or

  89388. ** ROWID on the P1 index.

  89389. **

  89390. ** If the P1 index entry is less than the key value then jump to P2.

  89391. ** Otherwise fall through to the next instruction.

  89392. */

  89393. /* Opcode: IdxLE P1 P2 P3 P4 P5

  89394. ** Synopsis: key=r[P3@P4]

  89395. **

  89396. ** The P4 register values beginning with P3 form an unpacked index 

  89397. ** key that omits the PRIMARY KEY or ROWID.  Compare this key value against

  89398. ** the index that P1 is currently pointing to, ignoring the PRIMARY KEY or

  89399. ** ROWID on the P1 index.

  89400. **

  89401. ** If the P1 index entry is less than or equal to the key value then jump

  89402. ** to P2. Otherwise fall through to the next instruction.

  89403. */

  89404. case OP_IdxLE:          /* jump */

  89405. case OP_IdxGT:          /* jump */

  89406. case OP_IdxLT:          /* jump */

  89407. case OP_IdxGE:  {       /* jump */

  89408.   VdbeCursor *pC;

  89409.   int res;

  89410.   UnpackedRecord r;

  89411. 

  89412.   assert( pOp->p1>=0 && pOp->p1<p->nCursor );

  89413.   pC = p->apCsr[pOp->p1];

  89414.   assert( pC!=0 );

  89415.   assert( pC->isOrdered );

  89416.   assert( pC->eCurType==CURTYPE_BTREE );

  89417.   assert( pC->uc.pCursor!=0);

  89418.   assert( pC->deferredMoveto==0 );

  89419.   assert( pOp->p5==0 || pOp->p5==1 );

  89420.   assert( pOp->p4type==P4_INT32 );

  89421.   r.pKeyInfo = pC->pKeyInfo;

  89422.   r.nField = (u16)pOp->p4.i;

  89423.   if( pOp->opcode<OP_IdxLT ){

  89424.     assert( pOp->opcode==OP_IdxLE || pOp->opcode==OP_IdxGT );

  89425.     r.default_rc = -1;

  89426.   }else{

  89427.     assert( pOp->opcode==OP_IdxGE || pOp->opcode==OP_IdxLT );

  89428.     r.default_rc = 0;

  89429.   }

  89430.   r.aMem = &aMem[pOp->p3];

  89431. #ifdef SQLITE_DEBUG

  89432.   {

  89433.     int i;

  89434.     for(i=0; i<r.nField; i++){

  89435.       assert( memIsValid(&r.aMem[i]) );

  89436.       REGISTER_TRACE(pOp->p3+i, &aMem[pOp->p3+i]);

  89437.     }

  89438.   }

  89439. #endif

  89440.   res = 0;  /* Not needed.  Only used to silence a warning. */

  89441.   rc = sqlite3VdbeIdxKeyCompare(db, pC, &r, &res);

  89442.   assert( (OP_IdxLE&1)==(OP_IdxLT&1) && (OP_IdxGE&1)==(OP_IdxGT&1) );

  89443.   if( (pOp->opcode&1)==(OP_IdxLT&1) ){

  89444.     assert( pOp->opcode==OP_IdxLE || pOp->opcode==OP_IdxLT );

  89445.     res = -res;

  89446.   }else{

  89447.     assert( pOp->opcode==OP_IdxGE || pOp->opcode==OP_IdxGT );

  89448.     res++;

  89449.   }

  89450.   VdbeBranchTaken(res>0,2);

  89451.   if( rc ) goto abort_due_to_error;

  89452.   if( res>0 ) goto jump_to_p2;

  89453.   break;

  89454. }

  89455. 

  89456. /* Opcode: Destroy P1 P2 P3 * *

  89457. **

  89458. ** Delete an entire database table or index whose root page in the database

  89459. ** file is given by P1.

  89460. **

  89461. ** The table being destroyed is in the main database file if P3==0.  If

  89462. ** P3==1 then the table to be clear is in the auxiliary database file

  89463. ** that is used to store tables create using CREATE TEMPORARY TABLE.

  89464. **

  89465. ** If AUTOVACUUM is enabled then it is possible that another root page

  89466. ** might be moved into the newly deleted root page in order to keep all

  89467. ** root pages contiguous at the beginning of the database.  The former

  89468. ** value of the root page that moved - its value before the move occurred -

  89469. ** is stored in register P2. If no page movement was required (because the

  89470. ** table being dropped was already the last one in the database) then a 

  89471. ** zero is stored in register P2.  If AUTOVACUUM is disabled then a zero 

  89472. ** is stored in register P2.

  89473. **

  89474. ** This opcode throws an error if there are any active reader VMs when

  89475. ** it is invoked. This is done to avoid the difficulty associated with 

  89476. ** updating existing cursors when a root page is moved in an AUTOVACUUM 

  89477. ** database. This error is thrown even if the database is not an AUTOVACUUM 

  89478. ** db in order to avoid introducing an incompatibility between autovacuum 

  89479. ** and non-autovacuum modes.

  89480. **

  89481. ** See also: Clear

  89482. */

  89483. case OP_Destroy: {     /* out2 */

  89484.   int iMoved;

  89485.   int iDb;

  89486. 

  89487.   sqlite3VdbeIncrWriteCounter(p, 0);

  89488.   assert( p->readOnly==0 );

  89489.   assert( pOp->p1>1 );

  89490.   pOut = out2Prerelease(p, pOp);

  89491.   pOut->flags = MEM_Null;

  89492.   if( db->nVdbeRead > db->nVDestroy+1 ){

  89493.     rc = SQLITE_LOCKED;

  89494.     p->errorAction = OE_Abort;

  89495.     goto abort_due_to_error;

  89496.   }else{

  89497.     iDb = pOp->p3;

  89498.     assert( DbMaskTest(p->btreeMask, iDb) );

  89499.     iMoved = 0;  /* Not needed.  Only to silence a warning. */

  89500.     rc = sqlite3BtreeDropTable(db->aDb[iDb].pBt, pOp->p1, &iMoved);

  89501.     pOut->flags = MEM_Int;

  89502.     pOut->u.i = iMoved;

  89503.     if( rc ) goto abort_due_to_error;

  89504. #ifndef SQLITE_OMIT_AUTOVACUUM

  89505.     if( iMoved!=0 ){

  89506.       sqlite3RootPageMoved(db, iDb, iMoved, pOp->p1);

  89507.       /* All OP_Destroy operations occur on the same btree */

  89508.       assert( resetSchemaOnFault==0 || resetSchemaOnFault==iDb+1 );

  89509.       resetSchemaOnFault = iDb+1;

  89510.     }

  89511. #endif

  89512.   }

  89513.   break;

  89514. }

  89515. 

  89516. /* Opcode: Clear P1 P2 P3

  89517. **

  89518. ** Delete all contents of the database table or index whose root page

  89519. ** in the database file is given by P1.  But, unlike Destroy, do not

  89520. ** remove the table or index from the database file.

  89521. **

  89522. ** The table being clear is in the main database file if P2==0.  If

  89523. ** P2==1 then the table to be clear is in the auxiliary database file

  89524. ** that is used to store tables create using CREATE TEMPORARY TABLE.

  89525. **

  89526. ** If the P3 value is non-zero, then the table referred to must be an

  89527. ** intkey table (an SQL table, not an index). In this case the row change 

  89528. ** count is incremented by the number of rows in the table being cleared. 

  89529. ** If P3 is greater than zero, then the value stored in register P3 is

  89530. ** also incremented by the number of rows in the table being cleared.

  89531. **

  89532. ** See also: Destroy

  89533. */

  89534. case OP_Clear: {

  89535.   int nChange;

  89536.  

  89537.   sqlite3VdbeIncrWriteCounter(p, 0);

  89538.   nChange = 0;

  89539.   assert( p->readOnly==0 );

  89540.   assert( DbMaskTest(p->btreeMask, pOp->p2) );

  89541.   rc = sqlite3BtreeClearTable(

  89542.       db->aDb[pOp->p2].pBt, pOp->p1, (pOp->p3 ? &nChange : 0)

  89543.   );

  89544.   if( pOp->p3 ){

  89545.     p->nChange += nChange;

  89546.     if( pOp->p3>0 ){

  89547.       assert( memIsValid(&aMem[pOp->p3]) );

  89548.       memAboutToChange(p, &aMem[pOp->p3]);

  89549.       aMem[pOp->p3].u.i += nChange;

  89550.     }

  89551.   }

  89552.   if( rc ) goto abort_due_to_error;

  89553.   break;

  89554. }

  89555. 

  89556. /* Opcode: ResetSorter P1 * * * *

  89557. **

  89558. ** Delete all contents from the ephemeral table or sorter

  89559. ** that is open on cursor P1.

  89560. **

  89561. ** This opcode only works for cursors used for sorting and

  89562. ** opened with OP_OpenEphemeral or OP_SorterOpen.

  89563. */

  89564. case OP_ResetSorter: {

  89565.   VdbeCursor *pC;

  89566.  

  89567.   assert( pOp->p1>=0 && pOp->p1<p->nCursor );

  89568.   pC = p->apCsr[pOp->p1];

  89569.   assert( pC!=0 );

  89570.   if( isSorter(pC) ){

  89571.     sqlite3VdbeSorterReset(db, pC->uc.pSorter);

  89572.   }else{

  89573.     assert( pC->eCurType==CURTYPE_BTREE );

  89574.     assert( pC->isEphemeral );

  89575.     rc = sqlite3BtreeClearTableOfCursor(pC->uc.pCursor);

  89576.     if( rc ) goto abort_due_to_error;

  89577.   }

  89578.   break;

  89579. }

  89580. 

  89581. /* Opcode: CreateBtree P1 P2 P3 * *

  89582. ** Synopsis: r[P2]=root iDb=P1 flags=P3

  89583. **

  89584. ** Allocate a new b-tree in the main database file if P1==0 or in the

  89585. ** TEMP database file if P1==1 or in an attached database if

  89586. ** P1>1.  The P3 argument must be 1 (BTREE_INTKEY) for a rowid table

  89587. ** it must be 2 (BTREE_BLOBKEY) for an index or WITHOUT ROWID table.

  89588. ** The root page number of the new b-tree is stored in register P2.

  89589. */

  89590. case OP_CreateBtree: {          /* out2 */

  89591.   int pgno;

  89592.   Db *pDb;

  89593. 

  89594.   sqlite3VdbeIncrWriteCounter(p, 0);

  89595.   pOut = out2Prerelease(p, pOp);

  89596.   pgno = 0;

  89597.   assert( pOp->p3==BTREE_INTKEY || pOp->p3==BTREE_BLOBKEY );

  89598.   assert( pOp->p1>=0 && pOp->p1<db->nDb );

  89599.   assert( DbMaskTest(p->btreeMask, pOp->p1) );

  89600.   assert( p->readOnly==0 );

  89601.   pDb = &db->aDb[pOp->p1];

  89602.   assert( pDb->pBt!=0 );

  89603.   rc = sqlite3BtreeCreateTable(pDb->pBt, &pgno, pOp->p3);

  89604.   if( rc ) goto abort_due_to_error;

  89605.   pOut->u.i = pgno;

  89606.   break;

  89607. }

  89608. 

  89609. /* Opcode: SqlExec * * * P4 *

  89610. **

  89611. ** Run the SQL statement or statements specified in the P4 string.

  89612. */

  89613. case OP_SqlExec: {

  89614.   sqlite3VdbeIncrWriteCounter(p, 0);

  89615.   db->nSqlExec++;

  89616.   rc = sqlite3_exec(db, pOp->p4.z, 0, 0, 0);

  89617.   db->nSqlExec--;

  89618.   if( rc ) goto abort_due_to_error;

  89619.   break;

  89620. }

  89621. 

  89622. /* Opcode: ParseSchema P1 * * P4 *

  89623. **

  89624. ** Read and parse all entries from the SQLITE_MASTER table of database P1

  89625. ** that match the WHERE clause P4.  If P4 is a NULL pointer, then the

  89626. ** entire schema for P1 is reparsed.

  89627. **

  89628. ** This opcode invokes the parser to create a new virtual machine,

  89629. ** then runs the new virtual machine.  It is thus a re-entrant opcode.

  89630. */

  89631. case OP_ParseSchema: {

  89632.   int iDb;

  89633.   const char *zMaster;

  89634.   char *zSql;

  89635.   InitData initData;

  89636. 

  89637.   /* Any prepared statement that invokes this opcode will hold mutexes

  89638.   ** on every btree.  This is a prerequisite for invoking 

  89639.   ** sqlite3InitCallback().

  89640.   */

  89641. #ifdef SQLITE_DEBUG

  89642.   for(iDb=0; iDb<db->nDb; iDb++){

  89643.     assert( iDb==1 || sqlite3BtreeHoldsMutex(db->aDb[iDb].pBt) );

  89644.   }

  89645. #endif

  89646. 

  89647.   iDb = pOp->p1;

  89648.   assert( iDb>=0 && iDb<db->nDb );

  89649.   assert( DbHasProperty(db, iDb, DB_SchemaLoaded) );

  89650. 

  89651. #ifndef SQLITE_OMIT_ALTERTABLE

  89652.   if( pOp->p4.z==0 ){

  89653.     sqlite3SchemaClear(db->aDb[iDb].pSchema);

  89654.     db->mDbFlags &= ~DBFLAG_SchemaKnownOk;

  89655.     rc = sqlite3InitOne(db, iDb, &p->zErrMsg, INITFLAG_AlterTable);

  89656.     db->mDbFlags |= DBFLAG_SchemaChange;

  89657.     p->expired = 0;

  89658.   }else

  89659. #endif

  89660.   {

  89661.     zMaster = MASTER_NAME;

  89662.     initData.db = db;

  89663.     initData.iDb = iDb;

  89664.     initData.pzErrMsg = &p->zErrMsg;

  89665.     initData.mInitFlags = 0;

  89666.     zSql = sqlite3MPrintf(db,

  89667.        "SELECT name, rootpage, sql FROM '%q'.%s WHERE %s ORDER BY rowid",

  89668.        db->aDb[iDb].zDbSName, zMaster, pOp->p4.z);

  89669.     if( zSql==0 ){

  89670.       rc = SQLITE_NOMEM_BKPT;

  89671.     }else{

  89672.       assert( db->init.busy==0 );

  89673.       db->init.busy = 1;

  89674.       initData.rc = SQLITE_OK;

  89675.       initData.nInitRow = 0;

  89676.       assert( !db->mallocFailed );

  89677.       rc = sqlite3_exec(db, zSql, sqlite3InitCallback, &initData, 0);

  89678.       if( rc==SQLITE_OK ) rc = initData.rc;

  89679.       if( rc==SQLITE_OK && initData.nInitRow==0 ){

  89680.         /* The OP_ParseSchema opcode with a non-NULL P4 argument should parse

  89681.         ** at least one SQL statement. Any less than that indicates that

  89682.         ** the sqlite_master table is corrupt. */

  89683.         rc = SQLITE_CORRUPT_BKPT;

  89684.       }

  89685.       sqlite3DbFreeNN(db, zSql);

  89686.       db->init.busy = 0;

  89687.     }

  89688.   }

  89689.   if( rc ){

  89690.     sqlite3ResetAllSchemasOfConnection(db);

  89691.     if( rc==SQLITE_NOMEM ){

  89692.       goto no_mem;

  89693.     }

  89694.     goto abort_due_to_error;

  89695.   }

  89696.   break;  

  89697. }

  89698. 

  89699. #if !defined(SQLITE_OMIT_ANALYZE)

  89700. /* Opcode: LoadAnalysis P1 * * * *

  89701. **

  89702. ** Read the sqlite_stat1 table for database P1 and load the content

  89703. ** of that table into the internal index hash table.  This will cause

  89704. ** the analysis to be used when preparing all subsequent queries.

  89705. */

  89706. case OP_LoadAnalysis: {

  89707.   assert( pOp->p1>=0 && pOp->p1<db->nDb );

  89708.   rc = sqlite3AnalysisLoad(db, pOp->p1);

  89709.   if( rc ) goto abort_due_to_error;

  89710.   break;  

  89711. }

  89712. #endif /* !defined(SQLITE_OMIT_ANALYZE) */

  89713. 

  89714. /* Opcode: DropTable P1 * * P4 *

  89715. **

  89716. ** Remove the internal (in-memory) data structures that describe

  89717. ** the table named P4 in database P1.  This is called after a table

  89718. ** is dropped from disk (using the Destroy opcode) in order to keep 

  89719. ** the internal representation of the

  89720. ** schema consistent with what is on disk.

  89721. */

  89722. case OP_DropTable: {

  89723.   sqlite3VdbeIncrWriteCounter(p, 0);

  89724.   sqlite3UnlinkAndDeleteTable(db, pOp->p1, pOp->p4.z);

  89725.   break;

  89726. }

  89727. 

  89728. /* Opcode: DropIndex P1 * * P4 *

  89729. **

  89730. ** Remove the internal (in-memory) data structures that describe

  89731. ** the index named P4 in database P1.  This is called after an index

  89732. ** is dropped from disk (using the Destroy opcode)

  89733. ** in order to keep the internal representation of the

  89734. ** schema consistent with what is on disk.

  89735. */

  89736. case OP_DropIndex: {

  89737.   sqlite3VdbeIncrWriteCounter(p, 0);

  89738.   sqlite3UnlinkAndDeleteIndex(db, pOp->p1, pOp->p4.z);

  89739.   break;

  89740. }

  89741. 

  89742. /* Opcode: DropTrigger P1 * * P4 *

  89743. **

  89744. ** Remove the internal (in-memory) data structures that describe

  89745. ** the trigger named P4 in database P1.  This is called after a trigger

  89746. ** is dropped from disk (using the Destroy opcode) in order to keep 

  89747. ** the internal representation of the

  89748. ** schema consistent with what is on disk.

  89749. */

  89750. case OP_DropTrigger: {

  89751.   sqlite3VdbeIncrWriteCounter(p, 0);

  89752.   sqlite3UnlinkAndDeleteTrigger(db, pOp->p1, pOp->p4.z);

  89753.   break;

  89754. }

  89755. 

  89756. 

  89757. #ifndef SQLITE_OMIT_INTEGRITY_CHECK

  89758. /* Opcode: IntegrityCk P1 P2 P3 P4 P5

  89759. **

  89760. ** Do an analysis of the currently open database.  Store in

  89761. ** register P1 the text of an error message describing any problems.

  89762. ** If no problems are found, store a NULL in register P1.

  89763. **

  89764. ** The register P3 contains one less than the maximum number of allowed errors.

  89765. ** At most reg(P3) errors will be reported.

  89766. ** In other words, the analysis stops as soon as reg(P1) errors are 

  89767. ** seen.  Reg(P1) is updated with the number of errors remaining.

  89768. **

  89769. ** The root page numbers of all tables in the database are integers

  89770. ** stored in P4_INTARRAY argument.

  89771. **

  89772. ** If P5 is not zero, the check is done on the auxiliary database

  89773. ** file, not the main database file.

  89774. **

  89775. ** This opcode is used to implement the integrity_check pragma.

  89776. */

  89777. case OP_IntegrityCk: {

  89778.   int nRoot;      /* Number of tables to check.  (Number of root pages.) */

  89779.   int *aRoot;     /* Array of rootpage numbers for tables to be checked */

  89780.   int nErr;       /* Number of errors reported */

  89781.   char *z;        /* Text of the error report */

  89782.   Mem *pnErr;     /* Register keeping track of errors remaining */

  89783. 

  89784.   assert( p->bIsReader );

  89785.   nRoot = pOp->p2;

  89786.   aRoot = pOp->p4.ai;

  89787.   assert( nRoot>0 );

  89788.   assert( aRoot[0]==nRoot );

  89789.   assert( pOp->p3>0 && pOp->p3<=(p->nMem+1 - p->nCursor) );

  89790.   pnErr = &aMem[pOp->p3];

  89791.   assert( (pnErr->flags & MEM_Int)!=0 );

  89792.   assert( (pnErr->flags & (MEM_Str|MEM_Blob))==0 );

  89793.   pIn1 = &aMem[pOp->p1];

  89794.   assert( pOp->p5<db->nDb );

  89795.   assert( DbMaskTest(p->btreeMask, pOp->p5) );

  89796.   z = sqlite3BtreeIntegrityCheck(db->aDb[pOp->p5].pBt, &aRoot[1], nRoot,

  89797.                                  (int)pnErr->u.i+1, &nErr);

  89798.   sqlite3VdbeMemSetNull(pIn1);

  89799.   if( nErr==0 ){

  89800.     assert( z==0 );

  89801.   }else if( z==0 ){

  89802.     goto no_mem;

  89803.   }else{

  89804.     pnErr->u.i -= nErr-1;

  89805.     sqlite3VdbeMemSetStr(pIn1, z, -1, SQLITE_UTF8, sqlite3_free);

  89806.   }

  89807.   UPDATE_MAX_BLOBSIZE(pIn1);

  89808.   sqlite3VdbeChangeEncoding(pIn1, encoding);

  89809.   break;

  89810. }

  89811. #endif /* SQLITE_OMIT_INTEGRITY_CHECK */

  89812. 

  89813. /* Opcode: RowSetAdd P1 P2 * * *

  89814. ** Synopsis: rowset(P1)=r[P2]

  89815. **

  89816. ** Insert the integer value held by register P2 into a RowSet object

  89817. ** held in register P1.

  89818. **

  89819. ** An assertion fails if P2 is not an integer.

  89820. */

  89821. case OP_RowSetAdd: {       /* in1, in2 */

  89822.   pIn1 = &aMem[pOp->p1];

  89823.   pIn2 = &aMem[pOp->p2];

  89824.   assert( (pIn2->flags & MEM_Int)!=0 );

  89825.   if( (pIn1->flags & MEM_Blob)==0 ){

  89826.     if( sqlite3VdbeMemSetRowSet(pIn1) ) goto no_mem;

  89827.   }

  89828.   assert( sqlite3VdbeMemIsRowSet(pIn1) );

  89829.   sqlite3RowSetInsert((RowSet*)pIn1->z, pIn2->u.i);

  89830.   break;

  89831. }

  89832. 

  89833. /* Opcode: RowSetRead P1 P2 P3 * *

  89834. ** Synopsis: r[P3]=rowset(P1)

  89835. **

  89836. ** Extract the smallest value from the RowSet object in P1

  89837. ** and put that value into register P3.

  89838. ** Or, if RowSet object P1 is initially empty, leave P3

  89839. ** unchanged and jump to instruction P2.

  89840. */

  89841. case OP_RowSetRead: {       /* jump, in1, out3 */

  89842.   i64 val;

  89843. 

  89844.   pIn1 = &aMem[pOp->p1];

  89845.   assert( (pIn1->flags & MEM_Blob)==0 || sqlite3VdbeMemIsRowSet(pIn1) );

  89846.   if( (pIn1->flags & MEM_Blob)==0 

  89847.    || sqlite3RowSetNext((RowSet*)pIn1->z, &val)==0

  89848.   ){

  89849.     /* The boolean index is empty */

  89850.     sqlite3VdbeMemSetNull(pIn1);

  89851.     VdbeBranchTaken(1,2);

  89852.     goto jump_to_p2_and_check_for_interrupt;

  89853.   }else{

  89854.     /* A value was pulled from the index */

  89855.     VdbeBranchTaken(0,2);

  89856.     sqlite3VdbeMemSetInt64(&aMem[pOp->p3], val);

  89857.   }

  89858.   goto check_for_interrupt;

  89859. }

  89860. 

  89861. /* Opcode: RowSetTest P1 P2 P3 P4

  89862. ** Synopsis: if r[P3] in rowset(P1) goto P2

  89863. **

  89864. ** Register P3 is assumed to hold a 64-bit integer value. If register P1

  89865. ** contains a RowSet object and that RowSet object contains

  89866. ** the value held in P3, jump to register P2. Otherwise, insert the

  89867. ** integer in P3 into the RowSet and continue on to the

  89868. ** next opcode.

  89869. **

  89870. ** The RowSet object is optimized for the case where sets of integers

  89871. ** are inserted in distinct phases, which each set contains no duplicates.

  89872. ** Each set is identified by a unique P4 value. The first set

  89873. ** must have P4==0, the final set must have P4==-1, and for all other sets

  89874. ** must have P4>0.

  89875. **

  89876. ** This allows optimizations: (a) when P4==0 there is no need to test

  89877. ** the RowSet object for P3, as it is guaranteed not to contain it,

  89878. ** (b) when P4==-1 there is no need to insert the value, as it will

  89879. ** never be tested for, and (c) when a value that is part of set X is

  89880. ** inserted, there is no need to search to see if the same value was

  89881. ** previously inserted as part of set X (only if it was previously

  89882. ** inserted as part of some other set).

  89883. */

  89884. case OP_RowSetTest: {                     /* jump, in1, in3 */

  89885.   int iSet;

  89886.   int exists;

  89887. 

  89888.   pIn1 = &aMem[pOp->p1];

  89889.   pIn3 = &aMem[pOp->p3];

  89890.   iSet = pOp->p4.i;

  89891.   assert( pIn3->flags&MEM_Int );

  89892. 

  89893.   /* If there is anything other than a rowset object in memory cell P1,

  89894.   ** delete it now and initialize P1 with an empty rowset

  89895.   */

  89896.   if( (pIn1->flags & MEM_Blob)==0 ){

  89897.     if( sqlite3VdbeMemSetRowSet(pIn1) ) goto no_mem;

  89898.   }

  89899.   assert( sqlite3VdbeMemIsRowSet(pIn1) );

  89900.   assert( pOp->p4type==P4_INT32 );

  89901.   assert( iSet==-1 || iSet>=0 );

  89902.   if( iSet ){

  89903.     exists = sqlite3RowSetTest((RowSet*)pIn1->z, iSet, pIn3->u.i);

  89904.     VdbeBranchTaken(exists!=0,2);

  89905.     if( exists ) goto jump_to_p2;

  89906.   }

  89907.   if( iSet>=0 ){

  89908.     sqlite3RowSetInsert((RowSet*)pIn1->z, pIn3->u.i);

  89909.   }

  89910.   break;

  89911. }

  89912. 

  89913. 

  89914. #ifndef SQLITE_OMIT_TRIGGER

  89915. 

  89916. /* Opcode: Program P1 P2 P3 P4 P5

  89917. **

  89918. ** Execute the trigger program passed as P4 (type P4_SUBPROGRAM). 

  89919. **

  89920. ** P1 contains the address of the memory cell that contains the first memory 

  89921. ** cell in an array of values used as arguments to the sub-program. P2 

  89922. ** contains the address to jump to if the sub-program throws an IGNORE 

  89923. ** exception using the RAISE() function. Register P3 contains the address 

  89924. ** of a memory cell in this (the parent) VM that is used to allocate the 

  89925. ** memory required by the sub-vdbe at runtime.

  89926. **

  89927. ** P4 is a pointer to the VM containing the trigger program.

  89928. **

  89929. ** If P5 is non-zero, then recursive program invocation is enabled.

  89930. */

  89931. case OP_Program: {        /* jump */

  89932.   int nMem;               /* Number of memory registers for sub-program */

  89933.   int nByte;              /* Bytes of runtime space required for sub-program */

  89934.   Mem *pRt;               /* Register to allocate runtime space */

  89935.   Mem *pMem;              /* Used to iterate through memory cells */

  89936.   Mem *pEnd;              /* Last memory cell in new array */

  89937.   VdbeFrame *pFrame;      /* New vdbe frame to execute in */

  89938.   SubProgram *pProgram;   /* Sub-program to execute */

  89939.   void *t;                /* Token identifying trigger */

  89940. 

  89941.   pProgram = pOp->p4.pProgram;

  89942.   pRt = &aMem[pOp->p3];

  89943.   assert( pProgram->nOp>0 );

  89944.   

  89945.   /* If the p5 flag is clear, then recursive invocation of triggers is 

  89946.   ** disabled for backwards compatibility (p5 is set if this sub-program

  89947.   ** is really a trigger, not a foreign key action, and the flag set

  89948.   ** and cleared by the "PRAGMA recursive_triggers" command is clear).

  89949.   ** 

  89950.   ** It is recursive invocation of triggers, at the SQL level, that is 

  89951.   ** disabled. In some cases a single trigger may generate more than one 

  89952.   ** SubProgram (if the trigger may be executed with more than one different 

  89953.   ** ON CONFLICT algorithm). SubProgram structures associated with a

  89954.   ** single trigger all have the same value for the SubProgram.token 

  89955.   ** variable.  */

  89956.   if( pOp->p5 ){

  89957.     t = pProgram->token;

  89958.     for(pFrame=p->pFrame; pFrame && pFrame->token!=t; pFrame=pFrame->pParent);

  89959.     if( pFrame ) break;

  89960.   }

  89961. 

  89962.   if( p->nFrame>=db->aLimit[SQLITE_LIMIT_TRIGGER_DEPTH] ){

  89963.     rc = SQLITE_ERROR;

  89964.     sqlite3VdbeError(p, "too many levels of trigger recursion");

  89965.     goto abort_due_to_error;

  89966.   }

  89967. 

  89968.   /* Register pRt is used to store the memory required to save the state

  89969.   ** of the current program, and the memory required at runtime to execute

  89970.   ** the trigger program. If this trigger has been fired before, then pRt 

  89971.   ** is already allocated. Otherwise, it must be initialized.  */

  89972.   if( (pRt->flags&MEM_Blob)==0 ){

  89973.     /* SubProgram.nMem is set to the number of memory cells used by the 

  89974.     ** program stored in SubProgram.aOp. As well as these, one memory

  89975.     ** cell is required for each cursor used by the program. Set local

  89976.     ** variable nMem (and later, VdbeFrame.nChildMem) to this value.

  89977.     */

  89978.     nMem = pProgram->nMem + pProgram->nCsr;

  89979.     assert( nMem>0 );

  89980.     if( pProgram->nCsr==0 ) nMem++;

  89981.     nByte = ROUND8(sizeof(VdbeFrame))

  89982.               + nMem * sizeof(Mem)

  89983.               + pProgram->nCsr * sizeof(VdbeCursor*)

  89984.               + (pProgram->nOp + 7)/8;

  89985.     pFrame = sqlite3DbMallocZero(db, nByte);

  89986.     if( !pFrame ){

  89987.       goto no_mem;

  89988.     }

  89989.     sqlite3VdbeMemRelease(pRt);

  89990.     pRt->flags = MEM_Blob|MEM_Dyn;

  89991.     pRt->z = (char*)pFrame;

  89992.     pRt->n = nByte;

  89993.     pRt->xDel = sqlite3VdbeFrameMemDel;

  89994. 

  89995.     pFrame->v = p;

  89996.     pFrame->nChildMem = nMem;

  89997.     pFrame->nChildCsr = pProgram->nCsr;

  89998.     pFrame->pc = (int)(pOp - aOp);

  89999.     pFrame->aMem = p->aMem;

  90000.     pFrame->nMem = p->nMem;

  90001.     pFrame->apCsr = p->apCsr;

  90002.     pFrame->nCursor = p->nCursor;

  90003.     pFrame->aOp = p->aOp;

  90004.     pFrame->nOp = p->nOp;

  90005.     pFrame->token = pProgram->token;

  90006. #ifdef SQLITE_ENABLE_STMT_SCANSTATUS

  90007.     pFrame->anExec = p->anExec;

  90008. #endif

  90009. #ifdef SQLITE_DEBUG

  90010.     pFrame->iFrameMagic = SQLITE_FRAME_MAGIC;

  90011. #endif

  90012. 

  90013.     pEnd = &VdbeFrameMem(pFrame)[pFrame->nChildMem];

  90014.     for(pMem=VdbeFrameMem(pFrame); pMem!=pEnd; pMem++){

  90015.       pMem->flags = MEM_Undefined;

  90016.       pMem->db = db;

  90017.     }

  90018.   }else{

  90019.     pFrame = (VdbeFrame*)pRt->z;

  90020.     assert( pRt->xDel==sqlite3VdbeFrameMemDel );

  90021.     assert( pProgram->nMem+pProgram->nCsr==pFrame->nChildMem 

  90022.         || (pProgram->nCsr==0 && pProgram->nMem+1==pFrame->nChildMem) );

  90023.     assert( pProgram->nCsr==pFrame->nChildCsr );

  90024.     assert( (int)(pOp - aOp)==pFrame->pc );

  90025.   }

  90026. 

  90027.   p->nFrame++;

  90028.   pFrame->pParent = p->pFrame;

  90029.   pFrame->lastRowid = db->lastRowid;

  90030.   pFrame->nChange = p->nChange;

  90031.   pFrame->nDbChange = p->db->nChange;

  90032.   assert( pFrame->pAuxData==0 );

  90033.   pFrame->pAuxData = p->pAuxData;

  90034.   p->pAuxData = 0;

  90035.   p->nChange = 0;

  90036.   p->pFrame = pFrame;

  90037.   p->aMem = aMem = VdbeFrameMem(pFrame);

  90038.   p->nMem = pFrame->nChildMem;

  90039.   p->nCursor = (u16)pFrame->nChildCsr;

  90040.   p->apCsr = (VdbeCursor **)&aMem[p->nMem];

  90041.   pFrame->aOnce = (u8*)&p->apCsr[pProgram->nCsr];

  90042.   memset(pFrame->aOnce, 0, (pProgram->nOp + 7)/8);

  90043.   p->aOp = aOp = pProgram->aOp;

  90044.   p->nOp = pProgram->nOp;

  90045. #ifdef SQLITE_ENABLE_STMT_SCANSTATUS

  90046.   p->anExec = 0;

  90047. #endif

  90048. #ifdef SQLITE_DEBUG

  90049.   /* Verify that second and subsequent executions of the same trigger do not

  90050.   ** try to reuse register values from the first use. */

  90051.   {

  90052.     int i;

  90053.     for(i=0; i<p->nMem; i++){

  90054.       aMem[i].pScopyFrom = 0;  /* Prevent false-positive AboutToChange() errs */

  90055.       aMem[i].flags |= MEM_Undefined; /* Cause a fault if this reg is reused */

  90056.     }

  90057.   }

  90058. #endif

  90059.   pOp = &aOp[-1];

  90060.   goto check_for_interrupt;

  90061. }

  90062. 

  90063. /* Opcode: Param P1 P2 * * *

  90064. **

  90065. ** This opcode is only ever present in sub-programs called via the 

  90066. ** OP_Program instruction. Copy a value currently stored in a memory 

  90067. ** cell of the calling (parent) frame to cell P2 in the current frames 

  90068. ** address space. This is used by trigger programs to access the new.* 

  90069. ** and old.* values.

  90070. **

  90071. ** The address of the cell in the parent frame is determined by adding

  90072. ** the value of the P1 argument to the value of the P1 argument to the

  90073. ** calling OP_Program instruction.

  90074. */

  90075. case OP_Param: {           /* out2 */

  90076.   VdbeFrame *pFrame;

  90077.   Mem *pIn;

  90078.   pOut = out2Prerelease(p, pOp);

  90079.   pFrame = p->pFrame;

  90080.   pIn = &pFrame->aMem[pOp->p1 + pFrame->aOp[pFrame->pc].p1];   

  90081.   sqlite3VdbeMemShallowCopy(pOut, pIn, MEM_Ephem);

  90082.   break;

  90083. }

  90084. 

  90085. #endif /* #ifndef SQLITE_OMIT_TRIGGER */

  90086. 

  90087. #ifndef SQLITE_OMIT_FOREIGN_KEY

  90088. /* Opcode: FkCounter P1 P2 * * *

  90089. ** Synopsis: fkctr[P1]+=P2

  90090. **

  90091. ** Increment a "constraint counter" by P2 (P2 may be negative or positive).

  90092. ** If P1 is non-zero, the database constraint counter is incremented 

  90093. ** (deferred foreign key constraints). Otherwise, if P1 is zero, the 

  90094. ** statement counter is incremented (immediate foreign key constraints).

  90095. */

  90096. case OP_FkCounter: {

  90097.   if( db->flags & SQLITE_DeferFKs ){

  90098.     db->nDeferredImmCons += pOp->p2;

  90099.   }else if( pOp->p1 ){

  90100.     db->nDeferredCons += pOp->p2;

  90101.   }else{

  90102.     p->nFkConstraint += pOp->p2;

  90103.   }

  90104.   break;

  90105. }

  90106. 

  90107. /* Opcode: FkIfZero P1 P2 * * *

  90108. ** Synopsis: if fkctr[P1]==0 goto P2

  90109. **

  90110. ** This opcode tests if a foreign key constraint-counter is currently zero.

  90111. ** If so, jump to instruction P2. Otherwise, fall through to the next 

  90112. ** instruction.

  90113. **

  90114. ** If P1 is non-zero, then the jump is taken if the database constraint-counter

  90115. ** is zero (the one that counts deferred constraint violations). If P1 is

  90116. ** zero, the jump is taken if the statement constraint-counter is zero

  90117. ** (immediate foreign key constraint violations).

  90118. */

  90119. case OP_FkIfZero: {         /* jump */

  90120.   if( pOp->p1 ){

  90121.     VdbeBranchTaken(db->nDeferredCons==0 && db->nDeferredImmCons==0, 2);

  90122.     if( db->nDeferredCons==0 && db->nDeferredImmCons==0 ) goto jump_to_p2;

  90123.   }else{

  90124.     VdbeBranchTaken(p->nFkConstraint==0 && db->nDeferredImmCons==0, 2);

  90125.     if( p->nFkConstraint==0 && db->nDeferredImmCons==0 ) goto jump_to_p2;

  90126.   }

  90127.   break;

  90128. }

  90129. #endif /* #ifndef SQLITE_OMIT_FOREIGN_KEY */

  90130. 

  90131. #ifndef SQLITE_OMIT_AUTOINCREMENT

  90132. /* Opcode: MemMax P1 P2 * * *

  90133. ** Synopsis: r[P1]=max(r[P1],r[P2])

  90134. **

  90135. ** P1 is a register in the root frame of this VM (the root frame is

  90136. ** different from the current frame if this instruction is being executed

  90137. ** within a sub-program). Set the value of register P1 to the maximum of 

  90138. ** its current value and the value in register P2.

  90139. **

  90140. ** This instruction throws an error if the memory cell is not initially

  90141. ** an integer.

  90142. */

  90143. case OP_MemMax: {        /* in2 */

  90144.   VdbeFrame *pFrame;

  90145.   if( p->pFrame ){

  90146.     for(pFrame=p->pFrame; pFrame->pParent; pFrame=pFrame->pParent);

  90147.     pIn1 = &pFrame->aMem[pOp->p1];

  90148.   }else{

  90149.     pIn1 = &aMem[pOp->p1];

  90150.   }

  90151.   assert( memIsValid(pIn1) );

  90152.   sqlite3VdbeMemIntegerify(pIn1);

  90153.   pIn2 = &aMem[pOp->p2];

  90154.   sqlite3VdbeMemIntegerify(pIn2);

  90155.   if( pIn1->u.i<pIn2->u.i){

  90156.     pIn1->u.i = pIn2->u.i;

  90157.   }

  90158.   break;

  90159. }

  90160. #endif /* SQLITE_OMIT_AUTOINCREMENT */

  90161. 

  90162. /* Opcode: IfPos P1 P2 P3 * *

  90163. ** Synopsis: if r[P1]>0 then r[P1]-=P3, goto P2

  90164. **

  90165. ** Register P1 must contain an integer.

  90166. ** If the value of register P1 is 1 or greater, subtract P3 from the

  90167. ** value in P1 and jump to P2.

  90168. **

  90169. ** If the initial value of register P1 is less than 1, then the

  90170. ** value is unchanged and control passes through to the next instruction.

  90171. */

  90172. case OP_IfPos: {        /* jump, in1 */

  90173.   pIn1 = &aMem[pOp->p1];

  90174.   assert( pIn1->flags&MEM_Int );

  90175.   VdbeBranchTaken( pIn1->u.i>0, 2);

  90176.   if( pIn1->u.i>0 ){

  90177.     pIn1->u.i -= pOp->p3;

  90178.     goto jump_to_p2;

  90179.   }

  90180.   break;

  90181. }

  90182. 

  90183. /* Opcode: OffsetLimit P1 P2 P3 * *

  90184. ** Synopsis: if r[P1]>0 then r[P2]=r[P1]+max(0,r[P3]) else r[P2]=(-1)

  90185. **

  90186. ** This opcode performs a commonly used computation associated with

  90187. ** LIMIT and OFFSET process.  r[P1] holds the limit counter.  r[P3]

  90188. ** holds the offset counter.  The opcode computes the combined value

  90189. ** of the LIMIT and OFFSET and stores that value in r[P2].  The r[P2]

  90190. ** value computed is the total number of rows that will need to be

  90191. ** visited in order to complete the query.

  90192. **

  90193. ** If r[P3] is zero or negative, that means there is no OFFSET

  90194. ** and r[P2] is set to be the value of the LIMIT, r[P1].

  90195. **

  90196. ** if r[P1] is zero or negative, that means there is no LIMIT

  90197. ** and r[P2] is set to -1. 

  90198. **

  90199. ** Otherwise, r[P2] is set to the sum of r[P1] and r[P3].

  90200. */

  90201. case OP_OffsetLimit: {    /* in1, out2, in3 */

  90202.   i64 x;

  90203.   pIn1 = &aMem[pOp->p1];

  90204.   pIn3 = &aMem[pOp->p3];

  90205.   pOut = out2Prerelease(p, pOp);

  90206.   assert( pIn1->flags & MEM_Int );

  90207.   assert( pIn3->flags & MEM_Int );

  90208.   x = pIn1->u.i;

  90209.   if( x<=0 || sqlite3AddInt64(&x, pIn3->u.i>0?pIn3->u.i:0) ){

  90210.     /* If the LIMIT is less than or equal to zero, loop forever.  This

  90211.     ** is documented.  But also, if the LIMIT+OFFSET exceeds 2^63 then

  90212.     ** also loop forever.  This is undocumented.  In fact, one could argue

  90213.     ** that the loop should terminate.  But assuming 1 billion iterations

  90214.     ** per second (far exceeding the capabilities of any current hardware)

  90215.     ** it would take nearly 300 years to actually reach the limit.  So

  90216.     ** looping forever is a reasonable approximation. */

  90217.     pOut->u.i = -1;

  90218.   }else{

  90219.     pOut->u.i = x;

  90220.   }

  90221.   break;

  90222. }

  90223. 

  90224. /* Opcode: IfNotZero P1 P2 * * *

  90225. ** Synopsis: if r[P1]!=0 then r[P1]--, goto P2

  90226. **

  90227. ** Register P1 must contain an integer.  If the content of register P1 is

  90228. ** initially greater than zero, then decrement the value in register P1.

  90229. ** If it is non-zero (negative or positive) and then also jump to P2.  

  90230. ** If register P1 is initially zero, leave it unchanged and fall through.

  90231. */

  90232. case OP_IfNotZero: {        /* jump, in1 */

  90233.   pIn1 = &aMem[pOp->p1];

  90234.   assert( pIn1->flags&MEM_Int );

  90235.   VdbeBranchTaken(pIn1->u.i<0, 2);

  90236.   if( pIn1->u.i ){

  90237.      if( pIn1->u.i>0 ) pIn1->u.i--;

  90238.      goto jump_to_p2;

  90239.   }

  90240.   break;

  90241. }

  90242. 

  90243. /* Opcode: DecrJumpZero P1 P2 * * *

  90244. ** Synopsis: if (--r[P1])==0 goto P2

  90245. **

  90246. ** Register P1 must hold an integer.  Decrement the value in P1

  90247. ** and jump to P2 if the new value is exactly zero.

  90248. */

  90249. case OP_DecrJumpZero: {      /* jump, in1 */

  90250.   pIn1 = &aMem[pOp->p1];

  90251.   assert( pIn1->flags&MEM_Int );

  90252.   if( pIn1->u.i>SMALLEST_INT64 ) pIn1->u.i--;

  90253.   VdbeBranchTaken(pIn1->u.i==0, 2);

  90254.   if( pIn1->u.i==0 ) goto jump_to_p2;

  90255.   break;

  90256. }

  90257. 

  90258. 

  90259. /* Opcode: AggStep * P2 P3 P4 P5

  90260. ** Synopsis: accum=r[P3] step(r[P2@P5])

  90261. **

  90262. ** Execute the xStep function for an aggregate.

  90263. ** The function has P5 arguments.  P4 is a pointer to the 

  90264. ** FuncDef structure that specifies the function.  Register P3 is the

  90265. ** accumulator.

  90266. **

  90267. ** The P5 arguments are taken from register P2 and its

  90268. ** successors.

  90269. */

  90270. /* Opcode: AggInverse * P2 P3 P4 P5

  90271. ** Synopsis: accum=r[P3] inverse(r[P2@P5])

  90272. **

  90273. ** Execute the xInverse function for an aggregate.

  90274. ** The function has P5 arguments.  P4 is a pointer to the 

  90275. ** FuncDef structure that specifies the function.  Register P3 is the

  90276. ** accumulator.

  90277. **

  90278. ** The P5 arguments are taken from register P2 and its

  90279. ** successors.

  90280. */

  90281. /* Opcode: AggStep1 P1 P2 P3 P4 P5

  90282. ** Synopsis: accum=r[P3] step(r[P2@P5])

  90283. **

  90284. ** Execute the xStep (if P1==0) or xInverse (if P1!=0) function for an

  90285. ** aggregate.  The function has P5 arguments.  P4 is a pointer to the 

  90286. ** FuncDef structure that specifies the function.  Register P3 is the

  90287. ** accumulator.

  90288. **

  90289. ** The P5 arguments are taken from register P2 and its

  90290. ** successors.

  90291. **

  90292. ** This opcode is initially coded as OP_AggStep0.  On first evaluation,

  90293. ** the FuncDef stored in P4 is converted into an sqlite3_context and

  90294. ** the opcode is changed.  In this way, the initialization of the

  90295. ** sqlite3_context only happens once, instead of on each call to the

  90296. ** step function.

  90297. */

  90298. case OP_AggInverse:

  90299. case OP_AggStep: {

  90300.   int n;

  90301.   sqlite3_context *pCtx;

  90302. 

  90303.   assert( pOp->p4type==P4_FUNCDEF );

  90304.   n = pOp->p5;

  90305.   assert( pOp->p3>0 && pOp->p3<=(p->nMem+1 - p->nCursor) );

  90306.   assert( n==0 || (pOp->p2>0 && pOp->p2+n<=(p->nMem+1 - p->nCursor)+1) );

  90307.   assert( pOp->p3<pOp->p2 || pOp->p3>=pOp->p2+n );

  90308.   pCtx = sqlite3DbMallocRawNN(db, n*sizeof(sqlite3_value*) +

  90309.                (sizeof(pCtx[0]) + sizeof(Mem) - sizeof(sqlite3_value*)));

  90310.   if( pCtx==0 ) goto no_mem;

  90311.   pCtx->pMem = 0;

  90312.   pCtx->pOut = (Mem*)&(pCtx->argv[n]);

  90313.   sqlite3VdbeMemInit(pCtx->pOut, db, MEM_Null);

  90314.   pCtx->pFunc = pOp->p4.pFunc;

  90315.   pCtx->iOp = (int)(pOp - aOp);

  90316.   pCtx->pVdbe = p;

  90317.   pCtx->skipFlag = 0;

  90318.   pCtx->isError = 0;

  90319.   pCtx->argc = n;

  90320.   pOp->p4type = P4_FUNCCTX;

  90321.   pOp->p4.pCtx = pCtx;

  90322. 

  90323.   /* OP_AggInverse must have P1==1 and OP_AggStep must have P1==0 */

  90324.   assert( pOp->p1==(pOp->opcode==OP_AggInverse) );

  90325. 

  90326.   pOp->opcode = OP_AggStep1;

  90327.   /* Fall through into OP_AggStep */

  90328. }

  90329. case OP_AggStep1: {

  90330.   int i;

  90331.   sqlite3_context *pCtx;

  90332.   Mem *pMem;

  90333. 

  90334.   assert( pOp->p4type==P4_FUNCCTX );

  90335.   pCtx = pOp->p4.pCtx;

  90336.   pMem = &aMem[pOp->p3];

  90337. 

  90338. #ifdef SQLITE_DEBUG

  90339.   if( pOp->p1 ){

  90340.     /* This is an OP_AggInverse call.  Verify that xStep has always

  90341.     ** been called at least once prior to any xInverse call. */

  90342.     assert( pMem->uTemp==0x1122e0e3 );

  90343.   }else{

  90344.     /* This is an OP_AggStep call.  Mark it as such. */

  90345.     pMem->uTemp = 0x1122e0e3;

  90346.   }

  90347. #endif

  90348. 

  90349.   /* If this function is inside of a trigger, the register array in aMem[]

  90350.   ** might change from one evaluation to the next.  The next block of code

  90351.   ** checks to see if the register array has changed, and if so it

  90352.   ** reinitializes the relavant parts of the sqlite3_context object */

  90353.   if( pCtx->pMem != pMem ){

  90354.     pCtx->pMem = pMem;

  90355.     for(i=pCtx->argc-1; i>=0; i--) pCtx->argv[i] = &aMem[pOp->p2+i];

  90356.   }

  90357. 

  90358. #ifdef SQLITE_DEBUG

  90359.   for(i=0; i<pCtx->argc; i++){

  90360.     assert( memIsValid(pCtx->argv[i]) );

  90361.     REGISTER_TRACE(pOp->p2+i, pCtx->argv[i]);

  90362.   }

  90363. #endif

  90364. 

  90365.   pMem->n++;

  90366.   assert( pCtx->pOut->flags==MEM_Null );

  90367.   assert( pCtx->isError==0 );

  90368.   assert( pCtx->skipFlag==0 );

  90369. #ifndef SQLITE_OMIT_WINDOWFUNC

  90370.   if( pOp->p1 ){

  90371.     (pCtx->pFunc->xInverse)(pCtx,pCtx->argc,pCtx->argv);

  90372.   }else

  90373. #endif

  90374.   (pCtx->pFunc->xSFunc)(pCtx,pCtx->argc,pCtx->argv); /* IMP: R-24505-23230 */

  90375. 

  90376.   if( pCtx->isError ){

  90377.     if( pCtx->isError>0 ){

  90378.       sqlite3VdbeError(p, "%s", sqlite3_value_text(pCtx->pOut));

  90379.       rc = pCtx->isError;

  90380.     }

  90381.     if( pCtx->skipFlag ){

  90382.       assert( pOp[-1].opcode==OP_CollSeq );

  90383.       i = pOp[-1].p1;

  90384.       if( i ) sqlite3VdbeMemSetInt64(&aMem[i], 1);

  90385.       pCtx->skipFlag = 0;

  90386.     }

  90387.     sqlite3VdbeMemRelease(pCtx->pOut);

  90388.     pCtx->pOut->flags = MEM_Null;

  90389.     pCtx->isError = 0;

  90390.     if( rc ) goto abort_due_to_error;

  90391.   }

  90392.   assert( pCtx->pOut->flags==MEM_Null );

  90393.   assert( pCtx->skipFlag==0 );

  90394.   break;

  90395. }

  90396. 

  90397. /* Opcode: AggFinal P1 P2 * P4 *

  90398. ** Synopsis: accum=r[P1] N=P2

  90399. **

  90400. ** P1 is the memory location that is the accumulator for an aggregate

  90401. ** or window function.  Execute the finalizer function 

  90402. ** for an aggregate and store the result in P1.

  90403. **

  90404. ** P2 is the number of arguments that the step function takes and

  90405. ** P4 is a pointer to the FuncDef for this function.  The P2

  90406. ** argument is not used by this opcode.  It is only there to disambiguate

  90407. ** functions that can take varying numbers of arguments.  The

  90408. ** P4 argument is only needed for the case where

  90409. ** the step function was not previously called.

  90410. */

  90411. /* Opcode: AggValue * P2 P3 P4 *

  90412. ** Synopsis: r[P3]=value N=P2

  90413. **

  90414. ** Invoke the xValue() function and store the result in register P3.

  90415. **

  90416. ** P2 is the number of arguments that the step function takes and

  90417. ** P4 is a pointer to the FuncDef for this function.  The P2

  90418. ** argument is not used by this opcode.  It is only there to disambiguate

  90419. ** functions that can take varying numbers of arguments.  The

  90420. ** P4 argument is only needed for the case where

  90421. ** the step function was not previously called.

  90422. */

  90423. case OP_AggValue:

  90424. case OP_AggFinal: {

  90425.   Mem *pMem;

  90426.   assert( pOp->p1>0 && pOp->p1<=(p->nMem+1 - p->nCursor) );

  90427.   assert( pOp->p3==0 || pOp->opcode==OP_AggValue );

  90428.   pMem = &aMem[pOp->p1];

  90429.   assert( (pMem->flags & ~(MEM_Null|MEM_Agg))==0 );

  90430. #ifndef SQLITE_OMIT_WINDOWFUNC

  90431.   if( pOp->p3 ){

  90432.     memAboutToChange(p, &aMem[pOp->p3]);

  90433.     rc = sqlite3VdbeMemAggValue(pMem, &aMem[pOp->p3], pOp->p4.pFunc);

  90434.     pMem = &aMem[pOp->p3];

  90435.   }else

  90436. #endif

  90437.   {

  90438.     rc = sqlite3VdbeMemFinalize(pMem, pOp->p4.pFunc);

  90439.   }

  90440.   

  90441.   if( rc ){

  90442.     sqlite3VdbeError(p, "%s", sqlite3_value_text(pMem));

  90443.     goto abort_due_to_error;

  90444.   }

  90445.   sqlite3VdbeChangeEncoding(pMem, encoding);

  90446.   UPDATE_MAX_BLOBSIZE(pMem);

  90447.   if( sqlite3VdbeMemTooBig(pMem) ){

  90448.     goto too_big;

  90449.   }

  90450.   break;

  90451. }

  90452. 

  90453. #ifndef SQLITE_OMIT_WAL

  90454. /* Opcode: Checkpoint P1 P2 P3 * *

  90455. **

  90456. ** Checkpoint database P1. This is a no-op if P1 is not currently in

  90457. ** WAL mode. Parameter P2 is one of SQLITE_CHECKPOINT_PASSIVE, FULL,

  90458. ** RESTART, or TRUNCATE.  Write 1 or 0 into mem[P3] if the checkpoint returns

  90459. ** SQLITE_BUSY or not, respectively.  Write the number of pages in the

  90460. ** WAL after the checkpoint into mem[P3+1] and the number of pages

  90461. ** in the WAL that have been checkpointed after the checkpoint

  90462. ** completes into mem[P3+2].  However on an error, mem[P3+1] and

  90463. ** mem[P3+2] are initialized to -1.

  90464. */

  90465. case OP_Checkpoint: {

  90466.   int i;                          /* Loop counter */

  90467.   int aRes[3];                    /* Results */

  90468.   Mem *pMem;                      /* Write results here */

  90469. 

  90470.   assert( p->readOnly==0 );

  90471.   aRes[0] = 0;

  90472.   aRes[1] = aRes[2] = -1;

  90473.   assert( pOp->p2==SQLITE_CHECKPOINT_PASSIVE

  90474.        || pOp->p2==SQLITE_CHECKPOINT_FULL

  90475.        || pOp->p2==SQLITE_CHECKPOINT_RESTART

  90476.        || pOp->p2==SQLITE_CHECKPOINT_TRUNCATE

  90477.   );

  90478.   rc = sqlite3Checkpoint(db, pOp->p1, pOp->p2, &aRes[1], &aRes[2]);

  90479.   if( rc ){

  90480.     if( rc!=SQLITE_BUSY ) goto abort_due_to_error;

  90481.     rc = SQLITE_OK;

  90482.     aRes[0] = 1;

  90483.   }

  90484.   for(i=0, pMem = &aMem[pOp->p3]; i<3; i++, pMem++){

  90485.     sqlite3VdbeMemSetInt64(pMem, (i64)aRes[i]);

  90486.   }    

  90487.   break;

  90488. };  

  90489. #endif

  90490. 

  90491. #ifndef SQLITE_OMIT_PRAGMA

  90492. /* Opcode: JournalMode P1 P2 P3 * *

  90493. **

  90494. ** Change the journal mode of database P1 to P3. P3 must be one of the

  90495. ** PAGER_JOURNALMODE_XXX values. If changing between the various rollback

  90496. ** modes (delete, truncate, persist, off and memory), this is a simple

  90497. ** operation. No IO is required.

  90498. **

  90499. ** If changing into or out of WAL mode the procedure is more complicated.

  90500. **

  90501. ** Write a string containing the final journal-mode to register P2.

  90502. */

  90503. case OP_JournalMode: {    /* out2 */

  90504.   Btree *pBt;                     /* Btree to change journal mode of */

  90505.   Pager *pPager;                  /* Pager associated with pBt */

  90506.   int eNew;                       /* New journal mode */

  90507.   int eOld;                       /* The old journal mode */

  90508. #ifndef SQLITE_OMIT_WAL

  90509.   const char *zFilename;          /* Name of database file for pPager */

  90510. #endif

  90511. 

  90512.   pOut = out2Prerelease(p, pOp);

  90513.   eNew = pOp->p3;

  90514.   assert( eNew==PAGER_JOURNALMODE_DELETE 

  90515.        || eNew==PAGER_JOURNALMODE_TRUNCATE 

  90516.        || eNew==PAGER_JOURNALMODE_PERSIST 

  90517.        || eNew==PAGER_JOURNALMODE_OFF

  90518.        || eNew==PAGER_JOURNALMODE_MEMORY

  90519.        || eNew==PAGER_JOURNALMODE_WAL

  90520.        || eNew==PAGER_JOURNALMODE_QUERY

  90521.   );

  90522.   assert( pOp->p1>=0 && pOp->p1<db->nDb );

  90523.   assert( p->readOnly==0 );

  90524. 

  90525.   pBt = db->aDb[pOp->p1].pBt;

  90526.   pPager = sqlite3BtreePager(pBt);

  90527.   eOld = sqlite3PagerGetJournalMode(pPager);

  90528.   if( eNew==PAGER_JOURNALMODE_QUERY ) eNew = eOld;

  90529.   if( !sqlite3PagerOkToChangeJournalMode(pPager) ) eNew = eOld;

  90530. 

  90531. #ifndef SQLITE_OMIT_WAL

  90532.   zFilename = sqlite3PagerFilename(pPager, 1);

  90533. 

  90534.   /* Do not allow a transition to journal_mode=WAL for a database

  90535.   ** in temporary storage or if the VFS does not support shared memory 

  90536.   */

  90537.   if( eNew==PAGER_JOURNALMODE_WAL

  90538.    && (sqlite3Strlen30(zFilename)==0           /* Temp file */

  90539.        || !sqlite3PagerWalSupported(pPager))   /* No shared-memory support */

  90540.   ){

  90541.     eNew = eOld;

  90542.   }

  90543. 

  90544.   if( (eNew!=eOld)

  90545.    && (eOld==PAGER_JOURNALMODE_WAL || eNew==PAGER_JOURNALMODE_WAL)

  90546.   ){

  90547.     if( !db->autoCommit || db->nVdbeRead>1 ){

  90548.       rc = SQLITE_ERROR;

  90549.       sqlite3VdbeError(p,

  90550.           "cannot change %s wal mode from within a transaction",

  90551.           (eNew==PAGER_JOURNALMODE_WAL ? "into" : "out of")

  90552.       );

  90553.       goto abort_due_to_error;

  90554.     }else{

  90555.  

  90556.       if( eOld==PAGER_JOURNALMODE_WAL ){

  90557.         /* If leaving WAL mode, close the log file. If successful, the call

  90558.         ** to PagerCloseWal() checkpoints and deletes the write-ahead-log 

  90559.         ** file. An EXCLUSIVE lock may still be held on the database file 

  90560.         ** after a successful return. 

  90561.         */

  90562.         rc = sqlite3PagerCloseWal(pPager, db);

  90563.         if( rc==SQLITE_OK ){

  90564.           sqlite3PagerSetJournalMode(pPager, eNew);

  90565.         }

  90566.       }else if( eOld==PAGER_JOURNALMODE_MEMORY ){

  90567.         /* Cannot transition directly from MEMORY to WAL.  Use mode OFF

  90568.         ** as an intermediate */

  90569.         sqlite3PagerSetJournalMode(pPager, PAGER_JOURNALMODE_OFF);

  90570.       }

  90571.   

  90572.       /* Open a transaction on the database file. Regardless of the journal

  90573.       ** mode, this transaction always uses a rollback journal.

  90574.       */

  90575.       assert( sqlite3BtreeIsInTrans(pBt)==0 );

  90576.       if( rc==SQLITE_OK ){

  90577.         rc = sqlite3BtreeSetVersion(pBt, (eNew==PAGER_JOURNALMODE_WAL ? 2 : 1));

  90578.       }

  90579.     }

  90580.   }

  90581. #endif /* ifndef SQLITE_OMIT_WAL */

  90582. 

  90583.   if( rc ) eNew = eOld;

  90584.   eNew = sqlite3PagerSetJournalMode(pPager, eNew);

  90585. 

  90586.   pOut->flags = MEM_Str|MEM_Static|MEM_Term;

  90587.   pOut->z = (char *)sqlite3JournalModename(eNew);

  90588.   pOut->n = sqlite3Strlen30(pOut->z);

  90589.   pOut->enc = SQLITE_UTF8;

  90590.   sqlite3VdbeChangeEncoding(pOut, encoding);

  90591.   if( rc ) goto abort_due_to_error;

  90592.   break;

  90593. };

  90594. #endif /* SQLITE_OMIT_PRAGMA */

  90595. 

  90596. #if !defined(SQLITE_OMIT_VACUUM) && !defined(SQLITE_OMIT_ATTACH)

  90597. /* Opcode: Vacuum P1 P2 * * *

  90598. **

  90599. ** Vacuum the entire database P1.  P1 is 0 for "main", and 2 or more

  90600. ** for an attached database.  The "temp" database may not be vacuumed.

  90601. **

  90602. ** If P2 is not zero, then it is a register holding a string which is

  90603. ** the file into which the result of vacuum should be written.  When

  90604. ** P2 is zero, the vacuum overwrites the original database.

  90605. */

  90606. case OP_Vacuum: {

  90607.   assert( p->readOnly==0 );

  90608.   rc = sqlite3RunVacuum(&p->zErrMsg, db, pOp->p1,

  90609.                         pOp->p2 ? &aMem[pOp->p2] : 0);

  90610.   if( rc ) goto abort_due_to_error;

  90611.   break;

  90612. }

  90613. #endif

  90614. 

  90615. #if !defined(SQLITE_OMIT_AUTOVACUUM)

  90616. /* Opcode: IncrVacuum P1 P2 * * *

  90617. **

  90618. ** Perform a single step of the incremental vacuum procedure on

  90619. ** the P1 database. If the vacuum has finished, jump to instruction

  90620. ** P2. Otherwise, fall through to the next instruction.

  90621. */

  90622. case OP_IncrVacuum: {        /* jump */

  90623.   Btree *pBt;

  90624. 

  90625.   assert( pOp->p1>=0 && pOp->p1<db->nDb );

  90626.   assert( DbMaskTest(p->btreeMask, pOp->p1) );

  90627.   assert( p->readOnly==0 );

  90628.   pBt = db->aDb[pOp->p1].pBt;

  90629.   rc = sqlite3BtreeIncrVacuum(pBt);

  90630.   VdbeBranchTaken(rc==SQLITE_DONE,2);

  90631.   if( rc ){

  90632.     if( rc!=SQLITE_DONE ) goto abort_due_to_error;

  90633.     rc = SQLITE_OK;

  90634.     goto jump_to_p2;

  90635.   }

  90636.   break;

  90637. }

  90638. #endif

  90639. 

  90640. /* Opcode: Expire P1 P2 * * *

  90641. **

  90642. ** Cause precompiled statements to expire.  When an expired statement

  90643. ** is executed using sqlite3_step() it will either automatically

  90644. ** reprepare itself (if it was originally created using sqlite3_prepare_v2())

  90645. ** or it will fail with SQLITE_SCHEMA.

  90646. ** 

  90647. ** If P1 is 0, then all SQL statements become expired. If P1 is non-zero,

  90648. ** then only the currently executing statement is expired.

  90649. **

  90650. ** If P2 is 0, then SQL statements are expired immediately.  If P2 is 1,

  90651. ** then running SQL statements are allowed to continue to run to completion.

  90652. ** The P2==1 case occurs when a CREATE INDEX or similar schema change happens

  90653. ** that might help the statement run faster but which does not affect the

  90654. ** correctness of operation.

  90655. */

  90656. case OP_Expire: {

  90657.   assert( pOp->p2==0 || pOp->p2==1 );

  90658.   if( !pOp->p1 ){

  90659.     sqlite3ExpirePreparedStatements(db, pOp->p2);

  90660.   }else{

  90661.     p->expired = pOp->p2+1;

  90662.   }

  90663.   break;

  90664. }

  90665. 

  90666. #ifndef SQLITE_OMIT_SHARED_CACHE

  90667. /* Opcode: TableLock P1 P2 P3 P4 *

  90668. ** Synopsis: iDb=P1 root=P2 write=P3

  90669. **

  90670. ** Obtain a lock on a particular table. This instruction is only used when

  90671. ** the shared-cache feature is enabled. 

  90672. **

  90673. ** P1 is the index of the database in sqlite3.aDb[] of the database

  90674. ** on which the lock is acquired.  A readlock is obtained if P3==0 or

  90675. ** a write lock if P3==1.

  90676. **

  90677. ** P2 contains the root-page of the table to lock.

  90678. **

  90679. ** P4 contains a pointer to the name of the table being locked. This is only

  90680. ** used to generate an error message if the lock cannot be obtained.

  90681. */

  90682. case OP_TableLock: {

  90683.   u8 isWriteLock = (u8)pOp->p3;

  90684.   if( isWriteLock || 0==(db->flags&SQLITE_ReadUncommit) ){

  90685.     int p1 = pOp->p1; 

  90686.     assert( p1>=0 && p1<db->nDb );

  90687.     assert( DbMaskTest(p->btreeMask, p1) );

  90688.     assert( isWriteLock==0 || isWriteLock==1 );

  90689.     rc = sqlite3BtreeLockTable(db->aDb[p1].pBt, pOp->p2, isWriteLock);

  90690.     if( rc ){

  90691.       if( (rc&0xFF)==SQLITE_LOCKED ){

  90692.         const char *z = pOp->p4.z;

  90693.         sqlite3VdbeError(p, "database table is locked: %s", z);

  90694.       }

  90695.       goto abort_due_to_error;

  90696.     }

  90697.   }

  90698.   break;

  90699. }

  90700. #endif /* SQLITE_OMIT_SHARED_CACHE */

  90701. 

  90702. #ifndef SQLITE_OMIT_VIRTUALTABLE

  90703. /* Opcode: VBegin * * * P4 *

  90704. **

  90705. ** P4 may be a pointer to an sqlite3_vtab structure. If so, call the 

  90706. ** xBegin method for that table.

  90707. **

  90708. ** Also, whether or not P4 is set, check that this is not being called from

  90709. ** within a callback to a virtual table xSync() method. If it is, the error

  90710. ** code will be set to SQLITE_LOCKED.

  90711. */

  90712. case OP_VBegin: {

  90713.   VTable *pVTab;

  90714.   pVTab = pOp->p4.pVtab;

  90715.   rc = sqlite3VtabBegin(db, pVTab);

  90716.   if( pVTab ) sqlite3VtabImportErrmsg(p, pVTab->pVtab);

  90717.   if( rc ) goto abort_due_to_error;

  90718.   break;

  90719. }

  90720. #endif /* SQLITE_OMIT_VIRTUALTABLE */

  90721. 

  90722. #ifndef SQLITE_OMIT_VIRTUALTABLE

  90723. /* Opcode: VCreate P1 P2 * * *

  90724. **

  90725. ** P2 is a register that holds the name of a virtual table in database 

  90726. ** P1. Call the xCreate method for that table.

  90727. */

  90728. case OP_VCreate: {

  90729.   Mem sMem;          /* For storing the record being decoded */

  90730.   const char *zTab;  /* Name of the virtual table */

  90731. 

  90732.   memset(&sMem, 0, sizeof(sMem));

  90733.   sMem.db = db;

  90734.   /* Because P2 is always a static string, it is impossible for the

  90735.   ** sqlite3VdbeMemCopy() to fail */

  90736.   assert( (aMem[pOp->p2].flags & MEM_Str)!=0 );

  90737.   assert( (aMem[pOp->p2].flags & MEM_Static)!=0 );

  90738.   rc = sqlite3VdbeMemCopy(&sMem, &aMem[pOp->p2]);

  90739.   assert( rc==SQLITE_OK );

  90740.   zTab = (const char*)sqlite3_value_text(&sMem);

  90741.   assert( zTab || db->mallocFailed );

  90742.   if( zTab ){

  90743.     rc = sqlite3VtabCallCreate(db, pOp->p1, zTab, &p->zErrMsg);

  90744.   }

  90745.   sqlite3VdbeMemRelease(&sMem);

  90746.   if( rc ) goto abort_due_to_error;

  90747.   break;

  90748. }

  90749. #endif /* SQLITE_OMIT_VIRTUALTABLE */

  90750. 

  90751. #ifndef SQLITE_OMIT_VIRTUALTABLE

  90752. /* Opcode: VDestroy P1 * * P4 *

  90753. **

  90754. ** P4 is the name of a virtual table in database P1.  Call the xDestroy method

  90755. ** of that table.

  90756. */

  90757. case OP_VDestroy: {

  90758.   db->nVDestroy++;

  90759.   rc = sqlite3VtabCallDestroy(db, pOp->p1, pOp->p4.z);

  90760.   db->nVDestroy--;

  90761.   assert( p->errorAction==OE_Abort && p->usesStmtJournal );

  90762.   if( rc ) goto abort_due_to_error;

  90763.   break;

  90764. }

  90765. #endif /* SQLITE_OMIT_VIRTUALTABLE */

  90766. 

  90767. #ifndef SQLITE_OMIT_VIRTUALTABLE

  90768. /* Opcode: VOpen P1 * * P4 *

  90769. **

  90770. ** P4 is a pointer to a virtual table object, an sqlite3_vtab structure.

  90771. ** P1 is a cursor number.  This opcode opens a cursor to the virtual

  90772. ** table and stores that cursor in P1.

  90773. */

  90774. case OP_VOpen: {

  90775.   VdbeCursor *pCur;

  90776.   sqlite3_vtab_cursor *pVCur;

  90777.   sqlite3_vtab *pVtab;

  90778.   const sqlite3_module *pModule;

  90779. 

  90780.   assert( p->bIsReader );

  90781.   pCur = 0;

  90782.   pVCur = 0;

  90783.   pVtab = pOp->p4.pVtab->pVtab;

  90784.   if( pVtab==0 || NEVER(pVtab->pModule==0) ){

  90785.     rc = SQLITE_LOCKED;

  90786.     goto abort_due_to_error;

  90787.   }

  90788.   pModule = pVtab->pModule;

  90789.   rc = pModule->xOpen(pVtab, &pVCur);

  90790.   sqlite3VtabImportErrmsg(p, pVtab);

  90791.   if( rc ) goto abort_due_to_error;

  90792. 

  90793.   /* Initialize sqlite3_vtab_cursor base class */

  90794.   pVCur->pVtab = pVtab;

  90795. 

  90796.   /* Initialize vdbe cursor object */

  90797.   pCur = allocateCursor(p, pOp->p1, 0, -1, CURTYPE_VTAB);

  90798.   if( pCur ){

  90799.     pCur->uc.pVCur = pVCur;

  90800.     pVtab->nRef++;

  90801.   }else{

  90802.     assert( db->mallocFailed );

  90803.     pModule->xClose(pVCur);

  90804.     goto no_mem;

  90805.   }

  90806.   break;

  90807. }

  90808. #endif /* SQLITE_OMIT_VIRTUALTABLE */

  90809. 

  90810. #ifndef SQLITE_OMIT_VIRTUALTABLE

  90811. /* Opcode: VFilter P1 P2 P3 P4 *

  90812. ** Synopsis: iplan=r[P3] zplan='P4'

  90813. **

  90814. ** P1 is a cursor opened using VOpen.  P2 is an address to jump to if

  90815. ** the filtered result set is empty.

  90816. **

  90817. ** P4 is either NULL or a string that was generated by the xBestIndex

  90818. ** method of the module.  The interpretation of the P4 string is left

  90819. ** to the module implementation.

  90820. **

  90821. ** This opcode invokes the xFilter method on the virtual table specified

  90822. ** by P1.  The integer query plan parameter to xFilter is stored in register

  90823. ** P3. Register P3+1 stores the argc parameter to be passed to the

  90824. ** xFilter method. Registers P3+2..P3+1+argc are the argc

  90825. ** additional parameters which are passed to

  90826. ** xFilter as argv. Register P3+2 becomes argv[0] when passed to xFilter.

  90827. **

  90828. ** A jump is made to P2 if the result set after filtering would be empty.

  90829. */

  90830. case OP_VFilter: {   /* jump */

  90831.   int nArg;

  90832.   int iQuery;

  90833.   const sqlite3_module *pModule;

  90834.   Mem *pQuery;

  90835.   Mem *pArgc;

  90836.   sqlite3_vtab_cursor *pVCur;

  90837.   sqlite3_vtab *pVtab;

  90838.   VdbeCursor *pCur;

  90839.   int res;

  90840.   int i;

  90841.   Mem **apArg;

  90842. 

  90843.   pQuery = &aMem[pOp->p3];

  90844.   pArgc = &pQuery[1];

  90845.   pCur = p->apCsr[pOp->p1];

  90846.   assert( memIsValid(pQuery) );

  90847.   REGISTER_TRACE(pOp->p3, pQuery);

  90848.   assert( pCur->eCurType==CURTYPE_VTAB );

  90849.   pVCur = pCur->uc.pVCur;

  90850.   pVtab = pVCur->pVtab;

  90851.   pModule = pVtab->pModule;

  90852. 

  90853.   /* Grab the index number and argc parameters */

  90854.   assert( (pQuery->flags&MEM_Int)!=0 && pArgc->flags==MEM_Int );

  90855.   nArg = (int)pArgc->u.i;

  90856.   iQuery = (int)pQuery->u.i;

  90857. 

  90858.   /* Invoke the xFilter method */

  90859.   res = 0;

  90860.   apArg = p->apArg;

  90861.   for(i = 0; i<nArg; i++){

  90862.     apArg[i] = &pArgc[i+1];

  90863.   }

  90864.   rc = pModule->xFilter(pVCur, iQuery, pOp->p4.z, nArg, apArg);

  90865.   sqlite3VtabImportErrmsg(p, pVtab);

  90866.   if( rc ) goto abort_due_to_error;

  90867.   res = pModule->xEof(pVCur);

  90868.   pCur->nullRow = 0;

  90869.   VdbeBranchTaken(res!=0,2);

  90870.   if( res ) goto jump_to_p2;

  90871.   break;

  90872. }

  90873. #endif /* SQLITE_OMIT_VIRTUALTABLE */

  90874. 

  90875. #ifndef SQLITE_OMIT_VIRTUALTABLE

  90876. /* Opcode: VColumn P1 P2 P3 * P5

  90877. ** Synopsis: r[P3]=vcolumn(P2)

  90878. **

  90879. ** Store in register P3 the value of the P2-th column of

  90880. ** the current row of the virtual-table of cursor P1.

  90881. **

  90882. ** If the VColumn opcode is being used to fetch the value of

  90883. ** an unchanging column during an UPDATE operation, then the P5

  90884. ** value is OPFLAG_NOCHNG.  This will cause the sqlite3_vtab_nochange()

  90885. ** function to return true inside the xColumn method of the virtual

  90886. ** table implementation.  The P5 column might also contain other

  90887. ** bits (OPFLAG_LENGTHARG or OPFLAG_TYPEOFARG) but those bits are

  90888. ** unused by OP_VColumn.

  90889. */

  90890. case OP_VColumn: {

  90891.   sqlite3_vtab *pVtab;

  90892.   const sqlite3_module *pModule;

  90893.   Mem *pDest;

  90894.   sqlite3_context sContext;

  90895. 

  90896.   VdbeCursor *pCur = p->apCsr[pOp->p1];

  90897.   assert( pCur->eCurType==CURTYPE_VTAB );

  90898.   assert( pOp->p3>0 && pOp->p3<=(p->nMem+1 - p->nCursor) );

  90899.   pDest = &aMem[pOp->p3];

  90900.   memAboutToChange(p, pDest);

  90901.   if( pCur->nullRow ){

  90902.     sqlite3VdbeMemSetNull(pDest);

  90903.     break;

  90904.   }

  90905.   pVtab = pCur->uc.pVCur->pVtab;

  90906.   pModule = pVtab->pModule;

  90907.   assert( pModule->xColumn );

  90908.   memset(&sContext, 0, sizeof(sContext));

  90909.   sContext.pOut = pDest;

  90910.   testcase( (pOp->p5 & OPFLAG_NOCHNG)==0 && pOp->p5!=0 );

  90911.   if( pOp->p5 & OPFLAG_NOCHNG ){

  90912.     sqlite3VdbeMemSetNull(pDest);

  90913.     pDest->flags = MEM_Null|MEM_Zero;

  90914.     pDest->u.nZero = 0;

  90915.   }else{

  90916.     MemSetTypeFlag(pDest, MEM_Null);

  90917.   }

  90918.   rc = pModule->xColumn(pCur->uc.pVCur, &sContext, pOp->p2);

  90919.   sqlite3VtabImportErrmsg(p, pVtab);

  90920.   if( sContext.isError>0 ){

  90921.     sqlite3VdbeError(p, "%s", sqlite3_value_text(pDest));

  90922.     rc = sContext.isError;

  90923.   }

  90924.   sqlite3VdbeChangeEncoding(pDest, encoding);

  90925.   REGISTER_TRACE(pOp->p3, pDest);

  90926.   UPDATE_MAX_BLOBSIZE(pDest);

  90927. 

  90928.   if( sqlite3VdbeMemTooBig(pDest) ){

  90929.     goto too_big;

  90930.   }

  90931.   if( rc ) goto abort_due_to_error;

  90932.   break;

  90933. }

  90934. #endif /* SQLITE_OMIT_VIRTUALTABLE */

  90935. 

  90936. #ifndef SQLITE_OMIT_VIRTUALTABLE

  90937. /* Opcode: VNext P1 P2 * * *

  90938. **

  90939. ** Advance virtual table P1 to the next row in its result set and

  90940. ** jump to instruction P2.  Or, if the virtual table has reached

  90941. ** the end of its result set, then fall through to the next instruction.

  90942. */

  90943. case OP_VNext: {   /* jump */

  90944.   sqlite3_vtab *pVtab;

  90945.   const sqlite3_module *pModule;

  90946.   int res;

  90947.   VdbeCursor *pCur;

  90948. 

  90949.   res = 0;

  90950.   pCur = p->apCsr[pOp->p1];

  90951.   assert( pCur->eCurType==CURTYPE_VTAB );

  90952.   if( pCur->nullRow ){

  90953.     break;

  90954.   }

  90955.   pVtab = pCur->uc.pVCur->pVtab;

  90956.   pModule = pVtab->pModule;

  90957.   assert( pModule->xNext );

  90958. 

  90959.   /* Invoke the xNext() method of the module. There is no way for the

  90960.   ** underlying implementation to return an error if one occurs during

  90961.   ** xNext(). Instead, if an error occurs, true is returned (indicating that 

  90962.   ** data is available) and the error code returned when xColumn or

  90963.   ** some other method is next invoked on the save virtual table cursor.

  90964.   */

  90965.   rc = pModule->xNext(pCur->uc.pVCur);

  90966.   sqlite3VtabImportErrmsg(p, pVtab);

  90967.   if( rc ) goto abort_due_to_error;

  90968.   res = pModule->xEof(pCur->uc.pVCur);

  90969.   VdbeBranchTaken(!res,2);

  90970.   if( !res ){

  90971.     /* If there is data, jump to P2 */

  90972.     goto jump_to_p2_and_check_for_interrupt;

  90973.   }

  90974.   goto check_for_interrupt;

  90975. }

  90976. #endif /* SQLITE_OMIT_VIRTUALTABLE */

  90977. 

  90978. #ifndef SQLITE_OMIT_VIRTUALTABLE

  90979. /* Opcode: VRename P1 * * P4 *

  90980. **

  90981. ** P4 is a pointer to a virtual table object, an sqlite3_vtab structure.

  90982. ** This opcode invokes the corresponding xRename method. The value

  90983. ** in register P1 is passed as the zName argument to the xRename method.

  90984. */

  90985. case OP_VRename: {

  90986.   sqlite3_vtab *pVtab;

  90987.   Mem *pName;

  90988.   int isLegacy;

  90989.   

  90990.   isLegacy = (db->flags & SQLITE_LegacyAlter);

  90991.   db->flags |= SQLITE_LegacyAlter;

  90992.   pVtab = pOp->p4.pVtab->pVtab;

  90993.   pName = &aMem[pOp->p1];

  90994.   assert( pVtab->pModule->xRename );

  90995.   assert( memIsValid(pName) );

  90996.   assert( p->readOnly==0 );

  90997.   REGISTER_TRACE(pOp->p1, pName);

  90998.   assert( pName->flags & MEM_Str );

  90999.   testcase( pName->enc==SQLITE_UTF8 );

  91000.   testcase( pName->enc==SQLITE_UTF16BE );

  91001.   testcase( pName->enc==SQLITE_UTF16LE );

  91002.   rc = sqlite3VdbeChangeEncoding(pName, SQLITE_UTF8);

  91003.   if( rc ) goto abort_due_to_error;

  91004.   rc = pVtab->pModule->xRename(pVtab, pName->z);

  91005.   if( isLegacy==0 ) db->flags &= ~(u64)SQLITE_LegacyAlter;

  91006.   sqlite3VtabImportErrmsg(p, pVtab);

  91007.   p->expired = 0;

  91008.   if( rc ) goto abort_due_to_error;

  91009.   break;

  91010. }

  91011. #endif

  91012. 

  91013. #ifndef SQLITE_OMIT_VIRTUALTABLE

  91014. /* Opcode: VUpdate P1 P2 P3 P4 P5

  91015. ** Synopsis: data=r[P3@P2]

  91016. **

  91017. ** P4 is a pointer to a virtual table object, an sqlite3_vtab structure.

  91018. ** This opcode invokes the corresponding xUpdate method. P2 values

  91019. ** are contiguous memory cells starting at P3 to pass to the xUpdate 

  91020. ** invocation. The value in register (P3+P2-1) corresponds to the 

  91021. ** p2th element of the argv array passed to xUpdate.

  91022. **

  91023. ** The xUpdate method will do a DELETE or an INSERT or both.

  91024. ** The argv[0] element (which corresponds to memory cell P3)

  91025. ** is the rowid of a row to delete.  If argv[0] is NULL then no 

  91026. ** deletion occurs.  The argv[1] element is the rowid of the new 

  91027. ** row.  This can be NULL to have the virtual table select the new 

  91028. ** rowid for itself.  The subsequent elements in the array are 

  91029. ** the values of columns in the new row.

  91030. **

  91031. ** If P2==1 then no insert is performed.  argv[0] is the rowid of

  91032. ** a row to delete.

  91033. **

  91034. ** P1 is a boolean flag. If it is set to true and the xUpdate call

  91035. ** is successful, then the value returned by sqlite3_last_insert_rowid() 

  91036. ** is set to the value of the rowid for the row just inserted.

  91037. **

  91038. ** P5 is the error actions (OE_Replace, OE_Fail, OE_Ignore, etc) to

  91039. ** apply in the case of a constraint failure on an insert or update.

  91040. */

  91041. case OP_VUpdate: {

  91042.   sqlite3_vtab *pVtab;

  91043.   const sqlite3_module *pModule;

  91044.   int nArg;

  91045.   int i;

  91046.   sqlite_int64 rowid;

  91047.   Mem **apArg;

  91048.   Mem *pX;

  91049. 

  91050.   assert( pOp->p2==1        || pOp->p5==OE_Fail   || pOp->p5==OE_Rollback 

  91051.        || pOp->p5==OE_Abort || pOp->p5==OE_Ignore || pOp->p5==OE_Replace

  91052.   );

  91053.   assert( p->readOnly==0 );

  91054.   if( db->mallocFailed ) goto no_mem;

  91055.   sqlite3VdbeIncrWriteCounter(p, 0);

  91056.   pVtab = pOp->p4.pVtab->pVtab;

  91057.   if( pVtab==0 || NEVER(pVtab->pModule==0) ){

  91058.     rc = SQLITE_LOCKED;

  91059.     goto abort_due_to_error;

  91060.   }

  91061.   pModule = pVtab->pModule;

  91062.   nArg = pOp->p2;

  91063.   assert( pOp->p4type==P4_VTAB );

  91064.   if( ALWAYS(pModule->xUpdate) ){

  91065.     u8 vtabOnConflict = db->vtabOnConflict;

  91066.     apArg = p->apArg;

  91067.     pX = &aMem[pOp->p3];

  91068.     for(i=0; i<nArg; i++){

  91069.       assert( memIsValid(pX) );

  91070.       memAboutToChange(p, pX);

  91071.       apArg[i] = pX;

  91072.       pX++;

  91073.     }

  91074.     db->vtabOnConflict = pOp->p5;

  91075.     rc = pModule->xUpdate(pVtab, nArg, apArg, &rowid);

  91076.     db->vtabOnConflict = vtabOnConflict;

  91077.     sqlite3VtabImportErrmsg(p, pVtab);

  91078.     if( rc==SQLITE_OK && pOp->p1 ){

  91079.       assert( nArg>1 && apArg[0] && (apArg[0]->flags&MEM_Null) );

  91080.       db->lastRowid = rowid;

  91081.     }

  91082.     if( (rc&0xff)==SQLITE_CONSTRAINT && pOp->p4.pVtab->bConstraint ){

  91083.       if( pOp->p5==OE_Ignore ){

  91084.         rc = SQLITE_OK;

  91085.       }else{

  91086.         p->errorAction = ((pOp->p5==OE_Replace) ? OE_Abort : pOp->p5);

  91087.       }

  91088.     }else{

  91089.       p->nChange++;

  91090.     }

  91091.     if( rc ) goto abort_due_to_error;

  91092.   }

  91093.   break;

  91094. }

  91095. #endif /* SQLITE_OMIT_VIRTUALTABLE */

  91096. 

  91097. #ifndef  SQLITE_OMIT_PAGER_PRAGMAS

  91098. /* Opcode: Pagecount P1 P2 * * *

  91099. **

  91100. ** Write the current number of pages in database P1 to memory cell P2.

  91101. */

  91102. case OP_Pagecount: {            /* out2 */

  91103.   pOut = out2Prerelease(p, pOp);

  91104.   pOut->u.i = sqlite3BtreeLastPage(db->aDb[pOp->p1].pBt);

  91105.   break;

  91106. }

  91107. #endif

  91108. 

  91109. 

  91110. #ifndef  SQLITE_OMIT_PAGER_PRAGMAS

  91111. /* Opcode: MaxPgcnt P1 P2 P3 * *

  91112. **

  91113. ** Try to set the maximum page count for database P1 to the value in P3.

  91114. ** Do not let the maximum page count fall below the current page count and

  91115. ** do not change the maximum page count value if P3==0.

  91116. **

  91117. ** Store the maximum page count after the change in register P2.

  91118. */

  91119. case OP_MaxPgcnt: {            /* out2 */

  91120.   unsigned int newMax;

  91121.   Btree *pBt;

  91122. 

  91123.   pOut = out2Prerelease(p, pOp);

  91124.   pBt = db->aDb[pOp->p1].pBt;

  91125.   newMax = 0;

  91126.   if( pOp->p3 ){

  91127.     newMax = sqlite3BtreeLastPage(pBt);

  91128.     if( newMax < (unsigned)pOp->p3 ) newMax = (unsigned)pOp->p3;

  91129.   }

  91130.   pOut->u.i = sqlite3BtreeMaxPageCount(pBt, newMax);

  91131.   break;

  91132. }

  91133. #endif

  91134. 

  91135. /* Opcode: Function0 P1 P2 P3 P4 P5

  91136. ** Synopsis: r[P3]=func(r[P2@P5])

  91137. **

  91138. ** Invoke a user function (P4 is a pointer to a FuncDef object that

  91139. ** defines the function) with P5 arguments taken from register P2 and

  91140. ** successors.  The result of the function is stored in register P3.

  91141. ** Register P3 must not be one of the function inputs.

  91142. **

  91143. ** P1 is a 32-bit bitmask indicating whether or not each argument to the 

  91144. ** function was determined to be constant at compile time. If the first

  91145. ** argument was constant then bit 0 of P1 is set. This is used to determine

  91146. ** whether meta data associated with a user function argument using the

  91147. ** sqlite3_set_auxdata() API may be safely retained until the next

  91148. ** invocation of this opcode.

  91149. **

  91150. ** See also: Function, AggStep, AggFinal

  91151. */

  91152. /* Opcode: Function P1 P2 P3 P4 P5

  91153. ** Synopsis: r[P3]=func(r[P2@P5])

  91154. **

  91155. ** Invoke a user function (P4 is a pointer to an sqlite3_context object that

  91156. ** contains a pointer to the function to be run) with P5 arguments taken

  91157. ** from register P2 and successors.  The result of the function is stored

  91158. ** in register P3.  Register P3 must not be one of the function inputs.

  91159. **

  91160. ** P1 is a 32-bit bitmask indicating whether or not each argument to the 

  91161. ** function was determined to be constant at compile time. If the first

  91162. ** argument was constant then bit 0 of P1 is set. This is used to determine

  91163. ** whether meta data associated with a user function argument using the

  91164. ** sqlite3_set_auxdata() API may be safely retained until the next

  91165. ** invocation of this opcode.

  91166. **

  91167. ** SQL functions are initially coded as OP_Function0 with P4 pointing

  91168. ** to a FuncDef object.  But on first evaluation, the P4 operand is

  91169. ** automatically converted into an sqlite3_context object and the operation

  91170. ** changed to this OP_Function opcode.  In this way, the initialization of

  91171. ** the sqlite3_context object occurs only once, rather than once for each

  91172. ** evaluation of the function.

  91173. **

  91174. ** See also: Function0, AggStep, AggFinal

  91175. */

  91176. case OP_PureFunc0:              /* group */

  91177. case OP_Function0: {            /* group */

  91178.   int n;

  91179.   sqlite3_context *pCtx;

  91180. 

  91181.   assert( pOp->p4type==P4_FUNCDEF );

  91182.   n = pOp->p5;

  91183.   assert( pOp->p3>0 && pOp->p3<=(p->nMem+1 - p->nCursor) );

  91184.   assert( n==0 || (pOp->p2>0 && pOp->p2+n<=(p->nMem+1 - p->nCursor)+1) );

  91185.   assert( pOp->p3<pOp->p2 || pOp->p3>=pOp->p2+n );

  91186.   pCtx = sqlite3DbMallocRawNN(db, sizeof(*pCtx) + (n-1)*sizeof(sqlite3_value*));

  91187.   if( pCtx==0 ) goto no_mem;

  91188.   pCtx->pOut = 0;

  91189.   pCtx->pFunc = pOp->p4.pFunc;

  91190.   pCtx->iOp = (int)(pOp - aOp);

  91191.   pCtx->pVdbe = p;

  91192.   pCtx->isError = 0;

  91193.   pCtx->argc = n;

  91194.   pOp->p4type = P4_FUNCCTX;

  91195.   pOp->p4.pCtx = pCtx;

  91196.   assert( OP_PureFunc == OP_PureFunc0+2 );

  91197.   assert( OP_Function == OP_Function0+2 );

  91198.   pOp->opcode += 2;

  91199.   /* Fall through into OP_Function */

  91200. }

  91201. case OP_PureFunc:              /* group */

  91202. case OP_Function: {            /* group */

  91203.   int i;

  91204.   sqlite3_context *pCtx;

  91205. 

  91206.   assert( pOp->p4type==P4_FUNCCTX );

  91207.   pCtx = pOp->p4.pCtx;

  91208. 

  91209.   /* If this function is inside of a trigger, the register array in aMem[]

  91210.   ** might change from one evaluation to the next.  The next block of code

  91211.   ** checks to see if the register array has changed, and if so it

  91212.   ** reinitializes the relavant parts of the sqlite3_context object */

  91213.   pOut = &aMem[pOp->p3];

  91214.   if( pCtx->pOut != pOut ){

  91215.     pCtx->pOut = pOut;

  91216.     for(i=pCtx->argc-1; i>=0; i--) pCtx->argv[i] = &aMem[pOp->p2+i];

  91217.   }

  91218. 

  91219.   memAboutToChange(p, pOut);

  91220. #ifdef SQLITE_DEBUG

  91221.   for(i=0; i<pCtx->argc; i++){

  91222.     assert( memIsValid(pCtx->argv[i]) );

  91223.     REGISTER_TRACE(pOp->p2+i, pCtx->argv[i]);

  91224.   }

  91225. #endif

  91226.   MemSetTypeFlag(pOut, MEM_Null);

  91227.   assert( pCtx->isError==0 );

  91228.   (*pCtx->pFunc->xSFunc)(pCtx, pCtx->argc, pCtx->argv);/* IMP: R-24505-23230 */

  91229. 

  91230.   /* If the function returned an error, throw an exception */

  91231.   if( pCtx->isError ){

  91232.     if( pCtx->isError>0 ){

  91233.       sqlite3VdbeError(p, "%s", sqlite3_value_text(pOut));

  91234.       rc = pCtx->isError;

  91235.     }

  91236.     sqlite3VdbeDeleteAuxData(db, &p->pAuxData, pCtx->iOp, pOp->p1);

  91237.     pCtx->isError = 0;

  91238.     if( rc ) goto abort_due_to_error;

  91239.   }

  91240. 

  91241.   /* Copy the result of the function into register P3 */

  91242.   if( pOut->flags & (MEM_Str|MEM_Blob) ){

  91243.     sqlite3VdbeChangeEncoding(pOut, encoding);

  91244.     if( sqlite3VdbeMemTooBig(pOut) ) goto too_big;

  91245.   }

  91246. 

  91247.   REGISTER_TRACE(pOp->p3, pOut);

  91248.   UPDATE_MAX_BLOBSIZE(pOut);

  91249.   break;

  91250. }

  91251. 

  91252. /* Opcode: Trace P1 P2 * P4 *

  91253. **

  91254. ** Write P4 on the statement trace output if statement tracing is

  91255. ** enabled.

  91256. **

  91257. ** Operand P1 must be 0x7fffffff and P2 must positive.

  91258. */

  91259. /* Opcode: Init P1 P2 P3 P4 *

  91260. ** Synopsis: Start at P2

  91261. **

  91262. ** Programs contain a single instance of this opcode as the very first

  91263. ** opcode.

  91264. **

  91265. ** If tracing is enabled (by the sqlite3_trace()) interface, then

  91266. ** the UTF-8 string contained in P4 is emitted on the trace callback.

  91267. ** Or if P4 is blank, use the string returned by sqlite3_sql().

  91268. **

  91269. ** If P2 is not zero, jump to instruction P2.

  91270. **

  91271. ** Increment the value of P1 so that OP_Once opcodes will jump the

  91272. ** first time they are evaluated for this run.

  91273. **

  91274. ** If P3 is not zero, then it is an address to jump to if an SQLITE_CORRUPT

  91275. ** error is encountered.

  91276. */

  91277. case OP_Trace:

  91278. case OP_Init: {          /* jump */

  91279.   int i;

  91280. #ifndef SQLITE_OMIT_TRACE

  91281.   char *zTrace;

  91282. #endif

  91283. 

  91284.   /* If the P4 argument is not NULL, then it must be an SQL comment string.

  91285.   ** The "--" string is broken up to prevent false-positives with srcck1.c.

  91286.   **

  91287.   ** This assert() provides evidence for:

  91288.   ** EVIDENCE-OF: R-50676-09860 The callback can compute the same text that

  91289.   ** would have been returned by the legacy sqlite3_trace() interface by

  91290.   ** using the X argument when X begins with "--" and invoking

  91291.   ** sqlite3_expanded_sql(P) otherwise.

  91292.   */

  91293.   assert( pOp->p4.z==0 || strncmp(pOp->p4.z, "-" "- ", 3)==0 );

  91294. 

  91295.   /* OP_Init is always instruction 0 */

  91296.   assert( pOp==p->aOp || pOp->opcode==OP_Trace );

  91297. 

  91298. #ifndef SQLITE_OMIT_TRACE

  91299.   if( (db->mTrace & (SQLITE_TRACE_STMT|SQLITE_TRACE_LEGACY))!=0

  91300.    && !p->doingRerun

  91301.    && (zTrace = (pOp->p4.z ? pOp->p4.z : p->zSql))!=0

  91302.   ){

  91303. #ifndef SQLITE_OMIT_DEPRECATED

  91304.     if( db->mTrace & SQLITE_TRACE_LEGACY ){

  91305.       void (*x)(void*,const char*) = (void(*)(void*,const char*))db->xTrace;

  91306.       char *z = sqlite3VdbeExpandSql(p, zTrace);

  91307.       x(db->pTraceArg, z);

  91308.       sqlite3_free(z);

  91309.     }else

  91310. #endif

  91311.     if( db->nVdbeExec>1 ){

  91312.       char *z = sqlite3MPrintf(db, "-- %s", zTrace);

  91313.       (void)db->xTrace(SQLITE_TRACE_STMT, db->pTraceArg, p, z);

  91314.       sqlite3DbFree(db, z);

  91315.     }else{

  91316.       (void)db->xTrace(SQLITE_TRACE_STMT, db->pTraceArg, p, zTrace);

  91317.     }

  91318.   }

  91319. #ifdef SQLITE_USE_FCNTL_TRACE

  91320.   zTrace = (pOp->p4.z ? pOp->p4.z : p->zSql);

  91321.   if( zTrace ){

  91322.     int j;

  91323.     for(j=0; j<db->nDb; j++){

  91324.       if( DbMaskTest(p->btreeMask, j)==0 ) continue;

  91325.       sqlite3_file_control(db, db->aDb[j].zDbSName, SQLITE_FCNTL_TRACE, zTrace);

  91326.     }

  91327.   }

  91328. #endif /* SQLITE_USE_FCNTL_TRACE */

  91329. #ifdef SQLITE_DEBUG

  91330.   if( (db->flags & SQLITE_SqlTrace)!=0

  91331.    && (zTrace = (pOp->p4.z ? pOp->p4.z : p->zSql))!=0

  91332.   ){

  91333.     sqlite3DebugPrintf("SQL-trace: %s\n", zTrace);

  91334.   }

  91335. #endif /* SQLITE_DEBUG */

  91336. #endif /* SQLITE_OMIT_TRACE */

  91337.   assert( pOp->p2>0 );

  91338.   if( pOp->p1>=sqlite3GlobalConfig.iOnceResetThreshold ){

  91339.     if( pOp->opcode==OP_Trace ) break;

  91340.     for(i=1; i<p->nOp; i++){

  91341.       if( p->aOp[i].opcode==OP_Once ) p->aOp[i].p1 = 0;

  91342.     }

  91343.     pOp->p1 = 0;

  91344.   }

  91345.   pOp->p1++;

  91346.   p->aCounter[SQLITE_STMTSTATUS_RUN]++;

  91347.   goto jump_to_p2;

  91348. }

  91349. 

  91350. #ifdef SQLITE_ENABLE_CURSOR_HINTS

  91351. /* Opcode: CursorHint P1 * * P4 *

  91352. **

  91353. ** Provide a hint to cursor P1 that it only needs to return rows that

  91354. ** satisfy the Expr in P4.  TK_REGISTER terms in the P4 expression refer

  91355. ** to values currently held in registers.  TK_COLUMN terms in the P4

  91356. ** expression refer to columns in the b-tree to which cursor P1 is pointing.

  91357. */

  91358. case OP_CursorHint: {

  91359.   VdbeCursor *pC;

  91360. 

  91361.   assert( pOp->p1>=0 && pOp->p1<p->nCursor );

  91362.   assert( pOp->p4type==P4_EXPR );

  91363.   pC = p->apCsr[pOp->p1];

  91364.   if( pC ){

  91365.     assert( pC->eCurType==CURTYPE_BTREE );

  91366.     sqlite3BtreeCursorHint(pC->uc.pCursor, BTREE_HINT_RANGE,

  91367.                            pOp->p4.pExpr, aMem);

  91368.   }

  91369.   break;

  91370. }

  91371. #endif /* SQLITE_ENABLE_CURSOR_HINTS */

  91372. 

  91373. #ifdef SQLITE_DEBUG

  91374. /* Opcode:  Abortable   * * * * *

  91375. **

  91376. ** Verify that an Abort can happen.  Assert if an Abort at this point

  91377. ** might cause database corruption.  This opcode only appears in debugging

  91378. ** builds.

  91379. **

  91380. ** An Abort is safe if either there have been no writes, or if there is

  91381. ** an active statement journal.

  91382. */

  91383. case OP_Abortable: {

  91384.   sqlite3VdbeAssertAbortable(p);

  91385.   break;

  91386. }

  91387. #endif

  91388. 

  91389. /* Opcode: Noop * * * * *

  91390. **

  91391. ** Do nothing.  This instruction is often useful as a jump

  91392. ** destination.

  91393. */

  91394. /*

  91395. ** The magic Explain opcode are only inserted when explain==2 (which

  91396. ** is to say when the EXPLAIN QUERY PLAN syntax is used.)

  91397. ** This opcode records information from the optimizer.  It is the

  91398. ** the same as a no-op.  This opcodesnever appears in a real VM program.

  91399. */

  91400. default: {          /* This is really OP_Noop, OP_Explain */

  91401.   assert( pOp->opcode==OP_Noop || pOp->opcode==OP_Explain );

  91402. 

  91403.   break;

  91404. }

  91405. 

  91406. /*****************************************************************************

  91407. ** The cases of the switch statement above this line should all be indented

  91408. ** by 6 spaces.  But the left-most 6 spaces have been removed to improve the

  91409. ** readability.  From this point on down, the normal indentation rules are

  91410. ** restored.

  91411. *****************************************************************************/

  91412.     }

  91413. 

  91414. #ifdef VDBE_PROFILE

  91415.     {

  91416.       u64 endTime = sqlite3NProfileCnt ? sqlite3NProfileCnt : sqlite3Hwtime();

  91417.       if( endTime>start ) pOrigOp->cycles += endTime - start;

  91418.       pOrigOp->cnt++;

  91419.     }

  91420. #endif

  91421. 

  91422.     /* The following code adds nothing to the actual functionality

  91423.     ** of the program.  It is only here for testing and debugging.

  91424.     ** On the other hand, it does burn CPU cycles every time through

  91425.     ** the evaluator loop.  So we can leave it out when NDEBUG is defined.

  91426.     */

  91427. #ifndef NDEBUG

  91428.     assert( pOp>=&aOp[-1] && pOp<&aOp[p->nOp-1] );

  91429. 

  91430. #ifdef SQLITE_DEBUG

  91431.     if( db->flags & SQLITE_VdbeTrace ){

  91432.       u8 opProperty = sqlite3OpcodeProperty[pOrigOp->opcode];

  91433.       if( rc!=0 ) printf("rc=%d\n",rc);

  91434.       if( opProperty & (OPFLG_OUT2) ){

  91435.         registerTrace(pOrigOp->p2, &aMem[pOrigOp->p2]);

  91436.       }

  91437.       if( opProperty & OPFLG_OUT3 ){

  91438.         registerTrace(pOrigOp->p3, &aMem[pOrigOp->p3]);

  91439.       }

  91440.     }

  91441. #endif  /* SQLITE_DEBUG */

  91442. #endif  /* NDEBUG */

  91443.   }  /* The end of the for(;;) loop the loops through opcodes */

  91444. 

  91445.   /* If we reach this point, it means that execution is finished with

  91446.   ** an error of some kind.

  91447.   */

  91448. abort_due_to_error:

  91449.   if( db->mallocFailed ) rc = SQLITE_NOMEM_BKPT;

  91450.   assert( rc );

  91451.   if( p->zErrMsg==0 && rc!=SQLITE_IOERR_NOMEM ){

  91452.     sqlite3VdbeError(p, "%s", sqlite3ErrStr(rc));

  91453.   }

  91454.   p->rc = rc;

  91455.   sqlite3SystemError(db, rc);

  91456.   testcase( sqlite3GlobalConfig.xLog!=0 );

  91457.   sqlite3_log(rc, "statement aborts at %d: [%s] %s", 

  91458.                    (int)(pOp - aOp), p->zSql, p->zErrMsg);

  91459.   sqlite3VdbeHalt(p);

  91460.   if( rc==SQLITE_IOERR_NOMEM ) sqlite3OomFault(db);

  91461.   rc = SQLITE_ERROR;

  91462.   if( resetSchemaOnFault>0 ){

  91463.     sqlite3ResetOneSchema(db, resetSchemaOnFault-1);

  91464.   }

  91465. 

  91466.   /* This is the only way out of this procedure.  We have to

  91467.   ** release the mutexes on btrees that were acquired at the

  91468.   ** top. */

  91469. vdbe_return:

  91470. #ifndef SQLITE_OMIT_PROGRESS_CALLBACK

  91471.   while( nVmStep>=nProgressLimit && db->xProgress!=0 ){

  91472.     nProgressLimit += db->nProgressOps;

  91473.     if( db->xProgress(db->pProgressArg) ){

  91474.       nProgressLimit = 0xffffffff;

  91475.       rc = SQLITE_INTERRUPT;

  91476.       goto abort_due_to_error;

  91477.     }

  91478.   }

  91479. #endif

  91480.   p->aCounter[SQLITE_STMTSTATUS_VM_STEP] += (int)nVmStep;

  91481.   sqlite3VdbeLeave(p);

  91482.   assert( rc!=SQLITE_OK || nExtraDelete==0 

  91483.        || sqlite3_strlike("DELETE%",p->zSql,0)!=0 

  91484.   );

  91485.   return rc;

  91486. 

  91487.   /* Jump to here if a string or blob larger than SQLITE_MAX_LENGTH

  91488.   ** is encountered.

  91489.   */

  91490. too_big:

  91491.   sqlite3VdbeError(p, "string or blob too big");

  91492.   rc = SQLITE_TOOBIG;

  91493.   goto abort_due_to_error;

  91494. 

  91495.   /* Jump to here if a malloc() fails.

  91496.   */

  91497. no_mem:

  91498.   sqlite3OomFault(db);

  91499.   sqlite3VdbeError(p, "out of memory");

  91500.   rc = SQLITE_NOMEM_BKPT;

  91501.   goto abort_due_to_error;

  91502. 

  91503.   /* Jump to here if the sqlite3_interrupt() API sets the interrupt

  91504.   ** flag.

  91505.   */

  91506. abort_due_to_interrupt:

  91507.   assert( db->u1.isInterrupted );

  91508.   rc = db->mallocFailed ? SQLITE_NOMEM_BKPT : SQLITE_INTERRUPT;

  91509.   p->rc = rc;

  91510.   sqlite3VdbeError(p, "%s", sqlite3ErrStr(rc));

  91511.   goto abort_due_to_error;

  91512. }

  91513. 

  91514. 

  91515. /************** End of vdbe.c ************************************************/

  91516. /************** Begin file vdbeblob.c ****************************************/

  91517. /*

  91518. ** 2007 May 1

  91519. **

  91520. ** The author disclaims copyright to this source code.  In place of

  91521. ** a legal notice, here is a blessing:

  91522. **

  91523. **    May you do good and not evil.

  91524. **    May you find forgiveness for yourself and forgive others.

  91525. **    May you share freely, never taking more than you give.

  91526. **

  91527. *************************************************************************

  91528. **

  91529. ** This file contains code used to implement incremental BLOB I/O.

  91530. */

  91531. 

  91532. /* #include "sqliteInt.h" */

  91533. /* #include "vdbeInt.h" */

  91534. 

  91535. #ifndef SQLITE_OMIT_INCRBLOB

  91536. 

  91537. /*

  91538. ** Valid sqlite3_blob* handles point to Incrblob structures.

  91539. */

  91540. typedef struct Incrblob Incrblob;

  91541. struct Incrblob {

  91542.   int nByte;              /* Size of open blob, in bytes */

  91543.   int iOffset;            /* Byte offset of blob in cursor data */

  91544.   u16 iCol;               /* Table column this handle is open on */

  91545.   BtCursor *pCsr;         /* Cursor pointing at blob row */

  91546.   sqlite3_stmt *pStmt;    /* Statement holding cursor open */

  91547.   sqlite3 *db;            /* The associated database */

  91548.   char *zDb;              /* Database name */

  91549.   Table *pTab;            /* Table object */

  91550. };

  91551. 

  91552. 

  91553. /*

  91554. ** This function is used by both blob_open() and blob_reopen(). It seeks

  91555. ** the b-tree cursor associated with blob handle p to point to row iRow.

  91556. ** If successful, SQLITE_OK is returned and subsequent calls to

  91557. ** sqlite3_blob_read() or sqlite3_blob_write() access the specified row.

  91558. **

  91559. ** If an error occurs, or if the specified row does not exist or does not

  91560. ** contain a value of type TEXT or BLOB in the column nominated when the

  91561. ** blob handle was opened, then an error code is returned and *pzErr may

  91562. ** be set to point to a buffer containing an error message. It is the

  91563. ** responsibility of the caller to free the error message buffer using

  91564. ** sqlite3DbFree().

  91565. **

  91566. ** If an error does occur, then the b-tree cursor is closed. All subsequent

  91567. ** calls to sqlite3_blob_read(), blob_write() or blob_reopen() will 

  91568. ** immediately return SQLITE_ABORT.

  91569. */

  91570. static int blobSeekToRow(Incrblob *p, sqlite3_int64 iRow, char **pzErr){

  91571.   int rc;                         /* Error code */

  91572.   char *zErr = 0;                 /* Error message */

  91573.   Vdbe *v = (Vdbe *)p->pStmt;

  91574. 

  91575.   /* Set the value of register r[1] in the SQL statement to integer iRow. 

  91576.   ** This is done directly as a performance optimization

  91577.   */

  91578.   v->aMem[1].flags = MEM_Int;

  91579.   v->aMem[1].u.i = iRow;

  91580. 

  91581.   /* If the statement has been run before (and is paused at the OP_ResultRow)

  91582.   ** then back it up to the point where it does the OP_NotExists.  This could

  91583.   ** have been down with an extra OP_Goto, but simply setting the program

  91584.   ** counter is faster. */

  91585.   if( v->pc>4 ){

  91586.     v->pc = 4;

  91587.     assert( v->aOp[v->pc].opcode==OP_NotExists );

  91588.     rc = sqlite3VdbeExec(v);

  91589.   }else{

  91590.     rc = sqlite3_step(p->pStmt);

  91591.   }

  91592.   if( rc==SQLITE_ROW ){

  91593.     VdbeCursor *pC = v->apCsr[0];

  91594.     u32 type = pC->nHdrParsed>p->iCol ? pC->aType[p->iCol] : 0;

  91595.     testcase( pC->nHdrParsed==p->iCol );

  91596.     testcase( pC->nHdrParsed==p->iCol+1 );

  91597.     if( type<12 ){

  91598.       zErr = sqlite3MPrintf(p->db, "cannot open value of type %s",

  91599.           type==0?"null": type==7?"real": "integer"

  91600.       );

  91601.       rc = SQLITE_ERROR;

  91602.       sqlite3_finalize(p->pStmt);

  91603.       p->pStmt = 0;

  91604.     }else{

  91605.       p->iOffset = pC->aType[p->iCol + pC->nField];

  91606.       p->nByte = sqlite3VdbeSerialTypeLen(type);

  91607.       p->pCsr =  pC->uc.pCursor;

  91608.       sqlite3BtreeIncrblobCursor(p->pCsr);

  91609.     }

  91610.   }

  91611. 

  91612.   if( rc==SQLITE_ROW ){

  91613.     rc = SQLITE_OK;

  91614.   }else if( p->pStmt ){

  91615.     rc = sqlite3_finalize(p->pStmt);

  91616.     p->pStmt = 0;

  91617.     if( rc==SQLITE_OK ){

  91618.       zErr = sqlite3MPrintf(p->db, "no such rowid: %lld", iRow);

  91619.       rc = SQLITE_ERROR;

  91620.     }else{

  91621.       zErr = sqlite3MPrintf(p->db, "%s", sqlite3_errmsg(p->db));

  91622.     }

  91623.   }

  91624. 

  91625.   assert( rc!=SQLITE_OK || zErr==0 );

  91626.   assert( rc!=SQLITE_ROW && rc!=SQLITE_DONE );

  91627. 

  91628.   *pzErr = zErr;

  91629.   return rc;

  91630. }

  91631. 

  91632. /*

  91633. ** Open a blob handle.

  91634. */

  91635. SQLITE_API int sqlite3_blob_open(

  91636.   sqlite3* db,            /* The database connection */

  91637.   const char *zDb,        /* The attached database containing the blob */

  91638.   const char *zTable,     /* The table containing the blob */

  91639.   const char *zColumn,    /* The column containing the blob */

  91640.   sqlite_int64 iRow,      /* The row containing the glob */

  91641.   int wrFlag,             /* True -> read/write access, false -> read-only */

  91642.   sqlite3_blob **ppBlob   /* Handle for accessing the blob returned here */

  91643. ){

  91644.   int nAttempt = 0;

  91645.   int iCol;               /* Index of zColumn in row-record */

  91646.   int rc = SQLITE_OK;

  91647.   char *zErr = 0;

  91648.   Table *pTab;

  91649.   Incrblob *pBlob = 0;

  91650.   Parse sParse;

  91651. 

  91652. #ifdef SQLITE_ENABLE_API_ARMOR

  91653.   if( ppBlob==0 ){

  91654.     return SQLITE_MISUSE_BKPT;

  91655.   }

  91656. #endif

  91657.   *ppBlob = 0;

  91658. #ifdef SQLITE_ENABLE_API_ARMOR

  91659.   if( !sqlite3SafetyCheckOk(db) || zTable==0 ){

  91660.     return SQLITE_MISUSE_BKPT;

  91661.   }

  91662. #endif

  91663.   wrFlag = !!wrFlag;                /* wrFlag = (wrFlag ? 1 : 0); */

  91664. 

  91665.   sqlite3_mutex_enter(db->mutex);

  91666. 

  91667.   pBlob = (Incrblob *)sqlite3DbMallocZero(db, sizeof(Incrblob));

  91668.   do {

  91669.     memset(&sParse, 0, sizeof(Parse));

  91670.     if( !pBlob ) goto blob_open_out;

  91671.     sParse.db = db;

  91672.     sqlite3DbFree(db, zErr);

  91673.     zErr = 0;

  91674. 

  91675.     sqlite3BtreeEnterAll(db);

  91676.     pTab = sqlite3LocateTable(&sParse, 0, zTable, zDb);

  91677.     if( pTab && IsVirtual(pTab) ){

  91678.       pTab = 0;

  91679.       sqlite3ErrorMsg(&sParse, "cannot open virtual table: %s", zTable);

  91680.     }

  91681.     if( pTab && !HasRowid(pTab) ){

  91682.       pTab = 0;

  91683.       sqlite3ErrorMsg(&sParse, "cannot open table without rowid: %s", zTable);

  91684.     }

  91685. #ifndef SQLITE_OMIT_VIEW

  91686.     if( pTab && pTab->pSelect ){

  91687.       pTab = 0;

  91688.       sqlite3ErrorMsg(&sParse, "cannot open view: %s", zTable);

  91689.     }

  91690. #endif

  91691.     if( !pTab ){

  91692.       if( sParse.zErrMsg ){

  91693.         sqlite3DbFree(db, zErr);

  91694.         zErr = sParse.zErrMsg;

  91695.         sParse.zErrMsg = 0;

  91696.       }

  91697.       rc = SQLITE_ERROR;

  91698.       sqlite3BtreeLeaveAll(db);

  91699.       goto blob_open_out;

  91700.     }

  91701.     pBlob->pTab = pTab;

  91702.     pBlob->zDb = db->aDb[sqlite3SchemaToIndex(db, pTab->pSchema)].zDbSName;

  91703. 

  91704.     /* Now search pTab for the exact column. */

  91705.     for(iCol=0; iCol<pTab->nCol; iCol++) {

  91706.       if( sqlite3StrICmp(pTab->aCol[iCol].zName, zColumn)==0 ){

  91707.         break;

  91708.       }

  91709.     }

  91710.     if( iCol==pTab->nCol ){

  91711.       sqlite3DbFree(db, zErr);

  91712.       zErr = sqlite3MPrintf(db, "no such column: \"%s\"", zColumn);

  91713.       rc = SQLITE_ERROR;

  91714.       sqlite3BtreeLeaveAll(db);

  91715.       goto blob_open_out;

  91716.     }

  91717. 

  91718.     /* If the value is being opened for writing, check that the

  91719.     ** column is not indexed, and that it is not part of a foreign key. 

  91720.     */

  91721.     if( wrFlag ){

  91722.       const char *zFault = 0;

  91723.       Index *pIdx;

  91724. #ifndef SQLITE_OMIT_FOREIGN_KEY

  91725.       if( db->flags&SQLITE_ForeignKeys ){

  91726.         /* Check that the column is not part of an FK child key definition. It

  91727.         ** is not necessary to check if it is part of a parent key, as parent

  91728.         ** key columns must be indexed. The check below will pick up this 

  91729.         ** case.  */

  91730.         FKey *pFKey;

  91731.         for(pFKey=pTab->pFKey; pFKey; pFKey=pFKey->pNextFrom){

  91732.           int j;

  91733.           for(j=0; j<pFKey->nCol; j++){

  91734.             if( pFKey->aCol[j].iFrom==iCol ){

  91735.               zFault = "foreign key";

  91736.             }

  91737.           }

  91738.         }

  91739.       }

  91740. #endif

  91741.       for(pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext){

  91742.         int j;

  91743.         for(j=0; j<pIdx->nKeyCol; j++){

  91744.           /* FIXME: Be smarter about indexes that use expressions */

  91745.           if( pIdx->aiColumn[j]==iCol || pIdx->aiColumn[j]==XN_EXPR ){

  91746.             zFault = "indexed";

  91747.           }

  91748.         }

  91749.       }

  91750.       if( zFault ){

  91751.         sqlite3DbFree(db, zErr);

  91752.         zErr = sqlite3MPrintf(db, "cannot open %s column for writing", zFault);

  91753.         rc = SQLITE_ERROR;

  91754.         sqlite3BtreeLeaveAll(db);

  91755.         goto blob_open_out;

  91756.       }

  91757.     }

  91758. 

  91759.     pBlob->pStmt = (sqlite3_stmt *)sqlite3VdbeCreate(&sParse);

  91760.     assert( pBlob->pStmt || db->mallocFailed );

  91761.     if( pBlob->pStmt ){

  91762.       

  91763.       /* This VDBE program seeks a btree cursor to the identified 

  91764.       ** db/table/row entry. The reason for using a vdbe program instead

  91765.       ** of writing code to use the b-tree layer directly is that the

  91766.       ** vdbe program will take advantage of the various transaction,

  91767.       ** locking and error handling infrastructure built into the vdbe.

  91768.       **

  91769.       ** After seeking the cursor, the vdbe executes an OP_ResultRow.

  91770.       ** Code external to the Vdbe then "borrows" the b-tree cursor and

  91771.       ** uses it to implement the blob_read(), blob_write() and 

  91772.       ** blob_bytes() functions.

  91773.       **

  91774.       ** The sqlite3_blob_close() function finalizes the vdbe program,

  91775.       ** which closes the b-tree cursor and (possibly) commits the 

  91776.       ** transaction.

  91777.       */

  91778.       static const int iLn = VDBE_OFFSET_LINENO(2);

  91779.       static const VdbeOpList openBlob[] = {

  91780.         {OP_TableLock,      0, 0, 0},  /* 0: Acquire a read or write lock */

  91781.         {OP_OpenRead,       0, 0, 0},  /* 1: Open a cursor */

  91782.         /* blobSeekToRow() will initialize r[1] to the desired rowid */

  91783.         {OP_NotExists,      0, 5, 1},  /* 2: Seek the cursor to rowid=r[1] */

  91784.         {OP_Column,         0, 0, 1},  /* 3  */

  91785.         {OP_ResultRow,      1, 0, 0},  /* 4  */

  91786.         {OP_Halt,           0, 0, 0},  /* 5  */

  91787.       };

  91788.       Vdbe *v = (Vdbe *)pBlob->pStmt;

  91789.       int iDb = sqlite3SchemaToIndex(db, pTab->pSchema);

  91790.       VdbeOp *aOp;

  91791. 

  91792.       sqlite3VdbeAddOp4Int(v, OP_Transaction, iDb, wrFlag, 

  91793.                            pTab->pSchema->schema_cookie,

  91794.                            pTab->pSchema->iGeneration);

  91795.       sqlite3VdbeChangeP5(v, 1);

  91796.       assert( sqlite3VdbeCurrentAddr(v)==2 || db->mallocFailed );

  91797.       aOp = sqlite3VdbeAddOpList(v, ArraySize(openBlob), openBlob, iLn);

  91798. 

  91799.       /* Make sure a mutex is held on the table to be accessed */

  91800.       sqlite3VdbeUsesBtree(v, iDb); 

  91801. 

  91802.       if( db->mallocFailed==0 ){

  91803.         assert( aOp!=0 );

  91804.         /* Configure the OP_TableLock instruction */

  91805. #ifdef SQLITE_OMIT_SHARED_CACHE

  91806.         aOp[0].opcode = OP_Noop;

  91807. #else

  91808.         aOp[0].p1 = iDb;

  91809.         aOp[0].p2 = pTab->tnum;

  91810.         aOp[0].p3 = wrFlag;

  91811.         sqlite3VdbeChangeP4(v, 2, pTab->zName, P4_TRANSIENT);

  91812.       }

  91813.       if( db->mallocFailed==0 ){

  91814. #endif

  91815. 

  91816.         /* Remove either the OP_OpenWrite or OpenRead. Set the P2 

  91817.         ** parameter of the other to pTab->tnum.  */

  91818.         if( wrFlag ) aOp[1].opcode = OP_OpenWrite;

  91819.         aOp[1].p2 = pTab->tnum;

  91820.         aOp[1].p3 = iDb;   

  91821. 

  91822.         /* Configure the number of columns. Configure the cursor to

  91823.         ** think that the table has one more column than it really

  91824.         ** does. An OP_Column to retrieve this imaginary column will

  91825.         ** always return an SQL NULL. This is useful because it means

  91826.         ** we can invoke OP_Column to fill in the vdbe cursors type 

  91827.         ** and offset cache without causing any IO.

  91828.         */

  91829.         aOp[1].p4type = P4_INT32;

  91830.         aOp[1].p4.i = pTab->nCol+1;

  91831.         aOp[3].p2 = pTab->nCol;

  91832. 

  91833.         sParse.nVar = 0;

  91834.         sParse.nMem = 1;

  91835.         sParse.nTab = 1;

  91836.         sqlite3VdbeMakeReady(v, &sParse);

  91837.       }

  91838.     }

  91839.    

  91840.     pBlob->iCol = iCol;

  91841.     pBlob->db = db;

  91842.     sqlite3BtreeLeaveAll(db);

  91843.     if( db->mallocFailed ){

  91844.       goto blob_open_out;

  91845.     }

  91846.     rc = blobSeekToRow(pBlob, iRow, &zErr);

  91847.   } while( (++nAttempt)<SQLITE_MAX_SCHEMA_RETRY && rc==SQLITE_SCHEMA );

  91848. 

  91849. blob_open_out:

  91850.   if( rc==SQLITE_OK && db->mallocFailed==0 ){

  91851.     *ppBlob = (sqlite3_blob *)pBlob;

  91852.   }else{

  91853.     if( pBlob && pBlob->pStmt ) sqlite3VdbeFinalize((Vdbe *)pBlob->pStmt);

  91854.     sqlite3DbFree(db, pBlob);

  91855.   }

  91856.   sqlite3ErrorWithMsg(db, rc, (zErr ? "%s" : 0), zErr);

  91857.   sqlite3DbFree(db, zErr);

  91858.   sqlite3ParserReset(&sParse);

  91859.   rc = sqlite3ApiExit(db, rc);

  91860.   sqlite3_mutex_leave(db->mutex);

  91861.   return rc;

  91862. }

  91863. 

  91864. /*

  91865. ** Close a blob handle that was previously created using

  91866. ** sqlite3_blob_open().

  91867. */

  91868. SQLITE_API int sqlite3_blob_close(sqlite3_blob *pBlob){

  91869.   Incrblob *p = (Incrblob *)pBlob;

  91870.   int rc;

  91871.   sqlite3 *db;

  91872. 

  91873.   if( p ){

  91874.     db = p->db;

  91875.     sqlite3_mutex_enter(db->mutex);

  91876.     rc = sqlite3_finalize(p->pStmt);

  91877.     sqlite3DbFree(db, p);

  91878.     sqlite3_mutex_leave(db->mutex);

  91879.   }else{

  91880.     rc = SQLITE_OK;

  91881.   }

  91882.   return rc;

  91883. }

  91884. 

  91885. /*

  91886. ** Perform a read or write operation on a blob

  91887. */

  91888. static int blobReadWrite(

  91889.   sqlite3_blob *pBlob, 

  91890.   void *z, 

  91891.   int n, 

  91892.   int iOffset, 

  91893.   int (*xCall)(BtCursor*, u32, u32, void*)

  91894. ){

  91895.   int rc;

  91896.   Incrblob *p = (Incrblob *)pBlob;

  91897.   Vdbe *v;

  91898.   sqlite3 *db;

  91899. 

  91900.   if( p==0 ) return SQLITE_MISUSE_BKPT;

  91901.   db = p->db;

  91902.   sqlite3_mutex_enter(db->mutex);

  91903.   v = (Vdbe*)p->pStmt;

  91904. 

  91905.   if( n<0 || iOffset<0 || ((sqlite3_int64)iOffset+n)>p->nByte ){

  91906.     /* Request is out of range. Return a transient error. */

  91907.     rc = SQLITE_ERROR;

  91908.   }else if( v==0 ){

  91909.     /* If there is no statement handle, then the blob-handle has

  91910.     ** already been invalidated. Return SQLITE_ABORT in this case.

  91911.     */

  91912.     rc = SQLITE_ABORT;

  91913.   }else{

  91914.     /* Call either BtreeData() or BtreePutData(). If SQLITE_ABORT is

  91915.     ** returned, clean-up the statement handle.

  91916.     */

  91917.     assert( db == v->db );

  91918.     sqlite3BtreeEnterCursor(p->pCsr);

  91919. 

  91920. #ifdef SQLITE_ENABLE_PREUPDATE_HOOK

  91921.     if( xCall==sqlite3BtreePutData && db->xPreUpdateCallback ){

  91922.       /* If a pre-update hook is registered and this is a write cursor, 

  91923.       ** invoke it here. 

  91924.       ** 

  91925.       ** TODO: The preupdate-hook is passed SQLITE_DELETE, even though this

  91926.       ** operation should really be an SQLITE_UPDATE. This is probably

  91927.       ** incorrect, but is convenient because at this point the new.* values 

  91928.       ** are not easily obtainable. And for the sessions module, an 

  91929.       ** SQLITE_UPDATE where the PK columns do not change is handled in the 

  91930.       ** same way as an SQLITE_DELETE (the SQLITE_DELETE code is actually

  91931.       ** slightly more efficient). Since you cannot write to a PK column

  91932.       ** using the incremental-blob API, this works. For the sessions module

  91933.       ** anyhow.

  91934.       */

  91935.       sqlite3_int64 iKey;

  91936.       iKey = sqlite3BtreeIntegerKey(p->pCsr);

  91937.       sqlite3VdbePreUpdateHook(

  91938.           v, v->apCsr[0], SQLITE_DELETE, p->zDb, p->pTab, iKey, -1

  91939.       );

  91940.     }

  91941. #endif

  91942. 

  91943.     rc = xCall(p->pCsr, iOffset+p->iOffset, n, z);

  91944.     sqlite3BtreeLeaveCursor(p->pCsr);

  91945.     if( rc==SQLITE_ABORT ){

  91946.       sqlite3VdbeFinalize(v);

  91947.       p->pStmt = 0;

  91948.     }else{

  91949.       v->rc = rc;

  91950.     }

  91951.   }

  91952.   sqlite3Error(db, rc);

  91953.   rc = sqlite3ApiExit(db, rc);

  91954.   sqlite3_mutex_leave(db->mutex);

  91955.   return rc;

  91956. }

  91957. 

  91958. /*

  91959. ** Read data from a blob handle.

  91960. */

  91961. SQLITE_API int sqlite3_blob_read(sqlite3_blob *pBlob, void *z, int n, int iOffset){

  91962.   return blobReadWrite(pBlob, z, n, iOffset, sqlite3BtreePayloadChecked);

  91963. }

  91964. 

  91965. /*

  91966. ** Write data to a blob handle.

  91967. */

  91968. SQLITE_API int sqlite3_blob_write(sqlite3_blob *pBlob, const void *z, int n, int iOffset){

  91969.   return blobReadWrite(pBlob, (void *)z, n, iOffset, sqlite3BtreePutData);

  91970. }

  91971. 

  91972. /*

  91973. ** Query a blob handle for the size of the data.

  91974. **

  91975. ** The Incrblob.nByte field is fixed for the lifetime of the Incrblob

  91976. ** so no mutex is required for access.

  91977. */

  91978. SQLITE_API int sqlite3_blob_bytes(sqlite3_blob *pBlob){

  91979.   Incrblob *p = (Incrblob *)pBlob;

  91980.   return (p && p->pStmt) ? p->nByte : 0;

  91981. }

  91982. 

  91983. /*

  91984. ** Move an existing blob handle to point to a different row of the same

  91985. ** database table.

  91986. **

  91987. ** If an error occurs, or if the specified row does not exist or does not

  91988. ** contain a blob or text value, then an error code is returned and the

  91989. ** database handle error code and message set. If this happens, then all 

  91990. ** subsequent calls to sqlite3_blob_xxx() functions (except blob_close()) 

  91991. ** immediately return SQLITE_ABORT.

  91992. */

  91993. SQLITE_API int sqlite3_blob_reopen(sqlite3_blob *pBlob, sqlite3_int64 iRow){

  91994.   int rc;

  91995.   Incrblob *p = (Incrblob *)pBlob;

  91996.   sqlite3 *db;

  91997. 

  91998.   if( p==0 ) return SQLITE_MISUSE_BKPT;

  91999.   db = p->db;

  92000.   sqlite3_mutex_enter(db->mutex);

  92001. 

  92002.   if( p->pStmt==0 ){

  92003.     /* If there is no statement handle, then the blob-handle has

  92004.     ** already been invalidated. Return SQLITE_ABORT in this case.

  92005.     */

  92006.     rc = SQLITE_ABORT;

  92007.   }else{

  92008.     char *zErr;

  92009.     rc = blobSeekToRow(p, iRow, &zErr);

  92010.     if( rc!=SQLITE_OK ){

  92011.       sqlite3ErrorWithMsg(db, rc, (zErr ? "%s" : 0), zErr);

  92012.       sqlite3DbFree(db, zErr);

  92013.     }

  92014.     assert( rc!=SQLITE_SCHEMA );

  92015.   }

  92016. 

  92017.   rc = sqlite3ApiExit(db, rc);

  92018.   assert( rc==SQLITE_OK || p->pStmt==0 );

  92019.   sqlite3_mutex_leave(db->mutex);

  92020.   return rc;

  92021. }

  92022. 

  92023. #endif /* #ifndef SQLITE_OMIT_INCRBLOB */

  92024. 

  92025. /************** End of vdbeblob.c ********************************************/

  92026. /************** Begin file vdbesort.c ****************************************/

  92027. /*

  92028. ** 2011-07-09

  92029. **

  92030. ** The author disclaims copyright to this source code.  In place of

  92031. ** a legal notice, here is a blessing:

  92032. **

  92033. **    May you do good and not evil.

  92034. **    May you find forgiveness for yourself and forgive others.

  92035. **    May you share freely, never taking more than you give.

  92036. **

  92037. *************************************************************************

  92038. ** This file contains code for the VdbeSorter object, used in concert with

  92039. ** a VdbeCursor to sort large numbers of keys for CREATE INDEX statements

  92040. ** or by SELECT statements with ORDER BY clauses that cannot be satisfied

  92041. ** using indexes and without LIMIT clauses.

  92042. **

  92043. ** The VdbeSorter object implements a multi-threaded external merge sort

  92044. ** algorithm that is efficient even if the number of elements being sorted

  92045. ** exceeds the available memory.

  92046. **

  92047. ** Here is the (internal, non-API) interface between this module and the

  92048. ** rest of the SQLite system:

  92049. **

  92050. **    sqlite3VdbeSorterInit()       Create a new VdbeSorter object.

  92051. **

  92052. **    sqlite3VdbeSorterWrite()      Add a single new row to the VdbeSorter

  92053. **                                  object.  The row is a binary blob in the

  92054. **                                  OP_MakeRecord format that contains both

  92055. **                                  the ORDER BY key columns and result columns

  92056. **                                  in the case of a SELECT w/ ORDER BY, or

  92057. **                                  the complete record for an index entry

  92058. **                                  in the case of a CREATE INDEX.

  92059. **

  92060. **    sqlite3VdbeSorterRewind()     Sort all content previously added.

  92061. **                                  Position the read cursor on the

  92062. **                                  first sorted element.

  92063. **

  92064. **    sqlite3VdbeSorterNext()       Advance the read cursor to the next sorted

  92065. **                                  element.

  92066. **

  92067. **    sqlite3VdbeSorterRowkey()     Return the complete binary blob for the

  92068. **                                  row currently under the read cursor.

  92069. **

  92070. **    sqlite3VdbeSorterCompare()    Compare the binary blob for the row

  92071. **                                  currently under the read cursor against

  92072. **                                  another binary blob X and report if

  92073. **                                  X is strictly less than the read cursor.

  92074. **                                  Used to enforce uniqueness in a

  92075. **                                  CREATE UNIQUE INDEX statement.

  92076. **

  92077. **    sqlite3VdbeSorterClose()      Close the VdbeSorter object and reclaim

  92078. **                                  all resources.

  92079. **

  92080. **    sqlite3VdbeSorterReset()      Refurbish the VdbeSorter for reuse.  This

  92081. **                                  is like Close() followed by Init() only

  92082. **                                  much faster.

  92083. **

  92084. ** The interfaces above must be called in a particular order.  Write() can 

  92085. ** only occur in between Init()/Reset() and Rewind().  Next(), Rowkey(), and

  92086. ** Compare() can only occur in between Rewind() and Close()/Reset(). i.e.

  92087. **

  92088. **   Init()

  92089. **   for each record: Write()

  92090. **   Rewind()

  92091. **     Rowkey()/Compare()

  92092. **   Next() 

  92093. **   Close()

  92094. **

  92095. ** Algorithm:

  92096. **

  92097. ** Records passed to the sorter via calls to Write() are initially held 

  92098. ** unsorted in main memory. Assuming the amount of memory used never exceeds

  92099. ** a threshold, when Rewind() is called the set of records is sorted using

  92100. ** an in-memory merge sort. In this case, no temporary files are required

  92101. ** and subsequent calls to Rowkey(), Next() and Compare() read records 

  92102. ** directly from main memory.

  92103. **

  92104. ** If the amount of space used to store records in main memory exceeds the

  92105. ** threshold, then the set of records currently in memory are sorted and

  92106. ** written to a temporary file in "Packed Memory Array" (PMA) format.

  92107. ** A PMA created at this point is known as a "level-0 PMA". Higher levels

  92108. ** of PMAs may be created by merging existing PMAs together - for example

  92109. ** merging two or more level-0 PMAs together creates a level-1 PMA.

  92110. **

  92111. ** The threshold for the amount of main memory to use before flushing 

  92112. ** records to a PMA is roughly the same as the limit configured for the

  92113. ** page-cache of the main database. Specifically, the threshold is set to 

  92114. ** the value returned by "PRAGMA main.page_size" multipled by 

  92115. ** that returned by "PRAGMA main.cache_size", in bytes.

  92116. **

  92117. ** If the sorter is running in single-threaded mode, then all PMAs generated

  92118. ** are appended to a single temporary file. Or, if the sorter is running in

  92119. ** multi-threaded mode then up to (N+1) temporary files may be opened, where

  92120. ** N is the configured number of worker threads. In this case, instead of

  92121. ** sorting the records and writing the PMA to a temporary file itself, the

  92122. ** calling thread usually launches a worker thread to do so. Except, if

  92123. ** there are already N worker threads running, the main thread does the work

  92124. ** itself.

  92125. **

  92126. ** The sorter is running in multi-threaded mode if (a) the library was built

  92127. ** with pre-processor symbol SQLITE_MAX_WORKER_THREADS set to a value greater

  92128. ** than zero, and (b) worker threads have been enabled at runtime by calling

  92129. ** "PRAGMA threads=N" with some value of N greater than 0.

  92130. **

  92131. ** When Rewind() is called, any data remaining in memory is flushed to a 

  92132. ** final PMA. So at this point the data is stored in some number of sorted

  92133. ** PMAs within temporary files on disk.

  92134. **

  92135. ** If there are fewer than SORTER_MAX_MERGE_COUNT PMAs in total and the

  92136. ** sorter is running in single-threaded mode, then these PMAs are merged

  92137. ** incrementally as keys are retreived from the sorter by the VDBE.  The

  92138. ** MergeEngine object, described in further detail below, performs this

  92139. ** merge.

  92140. **

  92141. ** Or, if running in multi-threaded mode, then a background thread is

  92142. ** launched to merge the existing PMAs. Once the background thread has

  92143. ** merged T bytes of data into a single sorted PMA, the main thread 

  92144. ** begins reading keys from that PMA while the background thread proceeds

  92145. ** with merging the next T bytes of data. And so on.

  92146. **

  92147. ** Parameter T is set to half the value of the memory threshold used 

  92148. ** by Write() above to determine when to create a new PMA.

  92149. **

  92150. ** If there are more than SORTER_MAX_MERGE_COUNT PMAs in total when 

  92151. ** Rewind() is called, then a hierarchy of incremental-merges is used. 

  92152. ** First, T bytes of data from the first SORTER_MAX_MERGE_COUNT PMAs on 

  92153. ** disk are merged together. Then T bytes of data from the second set, and

  92154. ** so on, such that no operation ever merges more than SORTER_MAX_MERGE_COUNT

  92155. ** PMAs at a time. This done is to improve locality.

  92156. **

  92157. ** If running in multi-threaded mode and there are more than

  92158. ** SORTER_MAX_MERGE_COUNT PMAs on disk when Rewind() is called, then more

  92159. ** than one background thread may be created. Specifically, there may be

  92160. ** one background thread for each temporary file on disk, and one background

  92161. ** thread to merge the output of each of the others to a single PMA for

  92162. ** the main thread to read from.

  92163. */

  92164. /* #include "sqliteInt.h" */

  92165. /* #include "vdbeInt.h" */

  92166. 

  92167. /* 

  92168. ** If SQLITE_DEBUG_SORTER_THREADS is defined, this module outputs various

  92169. ** messages to stderr that may be helpful in understanding the performance

  92170. ** characteristics of the sorter in multi-threaded mode.

  92171. */

  92172. #if 0

  92173. # define SQLITE_DEBUG_SORTER_THREADS 1

  92174. #endif

  92175. 

  92176. /*

  92177. ** Hard-coded maximum amount of data to accumulate in memory before flushing

  92178. ** to a level 0 PMA. The purpose of this limit is to prevent various integer

  92179. ** overflows. 512MiB.

  92180. */

  92181. #define SQLITE_MAX_PMASZ    (1<<29)

  92182. 

  92183. /*

  92184. ** Private objects used by the sorter

  92185. */

  92186. typedef struct MergeEngine MergeEngine;     /* Merge PMAs together */

  92187. typedef struct PmaReader PmaReader;         /* Incrementally read one PMA */

  92188. typedef struct PmaWriter PmaWriter;         /* Incrementally write one PMA */

  92189. typedef struct SorterRecord SorterRecord;   /* A record being sorted */

  92190. typedef struct SortSubtask SortSubtask;     /* A sub-task in the sort process */

  92191. typedef struct SorterFile SorterFile;       /* Temporary file object wrapper */

  92192. typedef struct SorterList SorterList;       /* In-memory list of records */

  92193. typedef struct IncrMerger IncrMerger;       /* Read & merge multiple PMAs */

  92194. 

  92195. /*

  92196. ** A container for a temp file handle and the current amount of data 

  92197. ** stored in the file.

  92198. */

  92199. struct SorterFile {

  92200.   sqlite3_file *pFd;              /* File handle */

  92201.   i64 iEof;                       /* Bytes of data stored in pFd */

  92202. };

  92203. 

  92204. /*

  92205. ** An in-memory list of objects to be sorted.

  92206. **

  92207. ** If aMemory==0 then each object is allocated separately and the objects

  92208. ** are connected using SorterRecord.u.pNext.  If aMemory!=0 then all objects

  92209. ** are stored in the aMemory[] bulk memory, one right after the other, and

  92210. ** are connected using SorterRecord.u.iNext.

  92211. */

  92212. struct SorterList {

  92213.   SorterRecord *pList;            /* Linked list of records */

  92214.   u8 *aMemory;                    /* If non-NULL, bulk memory to hold pList */

  92215.   int szPMA;                      /* Size of pList as PMA in bytes */

  92216. };

  92217. 

  92218. /*

  92219. ** The MergeEngine object is used to combine two or more smaller PMAs into

  92220. ** one big PMA using a merge operation.  Separate PMAs all need to be

  92221. ** combined into one big PMA in order to be able to step through the sorted

  92222. ** records in order.

  92223. **

  92224. ** The aReadr[] array contains a PmaReader object for each of the PMAs being

  92225. ** merged.  An aReadr[] object either points to a valid key or else is at EOF.

  92226. ** ("EOF" means "End Of File".  When aReadr[] is at EOF there is no more data.)

  92227. ** For the purposes of the paragraphs below, we assume that the array is

  92228. ** actually N elements in size, where N is the smallest power of 2 greater

  92229. ** to or equal to the number of PMAs being merged. The extra aReadr[] elements

  92230. ** are treated as if they are empty (always at EOF).

  92231. **

  92232. ** The aTree[] array is also N elements in size. The value of N is stored in

  92233. ** the MergeEngine.nTree variable.

  92234. **

  92235. ** The final (N/2) elements of aTree[] contain the results of comparing

  92236. ** pairs of PMA keys together. Element i contains the result of 

  92237. ** comparing aReadr[2*i-N] and aReadr[2*i-N+1]. Whichever key is smaller, the

  92238. ** aTree element is set to the index of it. 

  92239. **

  92240. ** For the purposes of this comparison, EOF is considered greater than any

  92241. ** other key value. If the keys are equal (only possible with two EOF

  92242. ** values), it doesn't matter which index is stored.

  92243. **

  92244. ** The (N/4) elements of aTree[] that precede the final (N/2) described 

  92245. ** above contains the index of the smallest of each block of 4 PmaReaders

  92246. ** And so on. So that aTree[1] contains the index of the PmaReader that 

  92247. ** currently points to the smallest key value. aTree[0] is unused.

  92248. **

  92249. ** Example:

  92250. **

  92251. **     aReadr[0] -> Banana

  92252. **     aReadr[1] -> Feijoa

  92253. **     aReadr[2] -> Elderberry

  92254. **     aReadr[3] -> Currant

  92255. **     aReadr[4] -> Grapefruit

  92256. **     aReadr[5] -> Apple

  92257. **     aReadr[6] -> Durian

  92258. **     aReadr[7] -> EOF

  92259. **

  92260. **     aTree[] = { X, 5   0, 5    0, 3, 5, 6 }

  92261. **

  92262. ** The current element is "Apple" (the value of the key indicated by 

  92263. ** PmaReader 5). When the Next() operation is invoked, PmaReader 5 will

  92264. ** be advanced to the next key in its segment. Say the next key is

  92265. ** "Eggplant":

  92266. **

  92267. **     aReadr[5] -> Eggplant

  92268. **

  92269. ** The contents of aTree[] are updated first by comparing the new PmaReader

  92270. ** 5 key to the current key of PmaReader 4 (still "Grapefruit"). The PmaReader

  92271. ** 5 value is still smaller, so aTree[6] is set to 5. And so on up the tree.

  92272. ** The value of PmaReader 6 - "Durian" - is now smaller than that of PmaReader

  92273. ** 5, so aTree[3] is set to 6. Key 0 is smaller than key 6 (Banana<Durian),

  92274. ** so the value written into element 1 of the array is 0. As follows:

  92275. **

  92276. **     aTree[] = { X, 0   0, 6    0, 3, 5, 6 }

  92277. **

  92278. ** In other words, each time we advance to the next sorter element, log2(N)

  92279. ** key comparison operations are required, where N is the number of segments

  92280. ** being merged (rounded up to the next power of 2).

  92281. */

  92282. struct MergeEngine {

  92283.   int nTree;                 /* Used size of aTree/aReadr (power of 2) */

  92284.   SortSubtask *pTask;        /* Used by this thread only */

  92285.   int *aTree;                /* Current state of incremental merge */

  92286.   PmaReader *aReadr;         /* Array of PmaReaders to merge data from */

  92287. };

  92288. 

  92289. /*

  92290. ** This object represents a single thread of control in a sort operation.

  92291. ** Exactly VdbeSorter.nTask instances of this object are allocated

  92292. ** as part of each VdbeSorter object. Instances are never allocated any

  92293. ** other way. VdbeSorter.nTask is set to the number of worker threads allowed

  92294. ** (see SQLITE_CONFIG_WORKER_THREADS) plus one (the main thread).  Thus for

  92295. ** single-threaded operation, there is exactly one instance of this object

  92296. ** and for multi-threaded operation there are two or more instances.

  92297. **

  92298. ** Essentially, this structure contains all those fields of the VdbeSorter

  92299. ** structure for which each thread requires a separate instance. For example,

  92300. ** each thread requries its own UnpackedRecord object to unpack records in

  92301. ** as part of comparison operations.

  92302. **

  92303. ** Before a background thread is launched, variable bDone is set to 0. Then, 

  92304. ** right before it exits, the thread itself sets bDone to 1. This is used for 

  92305. ** two purposes:

  92306. **

  92307. **   1. When flushing the contents of memory to a level-0 PMA on disk, to

  92308. **      attempt to select a SortSubtask for which there is not already an

  92309. **      active background thread (since doing so causes the main thread

  92310. **      to block until it finishes).

  92311. **

  92312. **   2. If SQLITE_DEBUG_SORTER_THREADS is defined, to determine if a call

  92313. **      to sqlite3ThreadJoin() is likely to block. Cases that are likely to

  92314. **      block provoke debugging output.

  92315. **

  92316. ** In both cases, the effects of the main thread seeing (bDone==0) even

  92317. ** after the thread has finished are not dire. So we don't worry about

  92318. ** memory barriers and such here.

  92319. */

  92320. typedef int (*SorterCompare)(SortSubtask*,int*,const void*,int,const void*,int);

  92321. struct SortSubtask {

  92322.   SQLiteThread *pThread;          /* Background thread, if any */

  92323.   int bDone;                      /* Set if thread is finished but not joined */

  92324.   VdbeSorter *pSorter;            /* Sorter that owns this sub-task */

  92325.   UnpackedRecord *pUnpacked;      /* Space to unpack a record */

  92326.   SorterList list;                /* List for thread to write to a PMA */

  92327.   int nPMA;                       /* Number of PMAs currently in file */

  92328.   SorterCompare xCompare;         /* Compare function to use */

  92329.   SorterFile file;                /* Temp file for level-0 PMAs */

  92330.   SorterFile file2;               /* Space for other PMAs */

  92331. };

  92332. 

  92333. 

  92334. /*

  92335. ** Main sorter structure. A single instance of this is allocated for each 

  92336. ** sorter cursor created by the VDBE.

  92337. **

  92338. ** mxKeysize:

  92339. **   As records are added to the sorter by calls to sqlite3VdbeSorterWrite(),

  92340. **   this variable is updated so as to be set to the size on disk of the

  92341. **   largest record in the sorter.

  92342. */

  92343. struct VdbeSorter {

  92344.   int mnPmaSize;                  /* Minimum PMA size, in bytes */

  92345.   int mxPmaSize;                  /* Maximum PMA size, in bytes.  0==no limit */

  92346.   int mxKeysize;                  /* Largest serialized key seen so far */

  92347.   int pgsz;                       /* Main database page size */

  92348.   PmaReader *pReader;             /* Readr data from here after Rewind() */

  92349.   MergeEngine *pMerger;           /* Or here, if bUseThreads==0 */

  92350.   sqlite3 *db;                    /* Database connection */

  92351.   KeyInfo *pKeyInfo;              /* How to compare records */

  92352.   UnpackedRecord *pUnpacked;      /* Used by VdbeSorterCompare() */

  92353.   SorterList list;                /* List of in-memory records */

  92354.   int iMemory;                    /* Offset of free space in list.aMemory */

  92355.   int nMemory;                    /* Size of list.aMemory allocation in bytes */

  92356.   u8 bUsePMA;                     /* True if one or more PMAs created */

  92357.   u8 bUseThreads;                 /* True to use background threads */

  92358.   u8 iPrev;                       /* Previous thread used to flush PMA */

  92359.   u8 nTask;                       /* Size of aTask[] array */

  92360.   u8 typeMask;

  92361.   SortSubtask aTask[1];           /* One or more subtasks */

  92362. };

  92363. 

  92364. #define SORTER_TYPE_INTEGER 0x01

  92365. #define SORTER_TYPE_TEXT    0x02

  92366. 

  92367. /*

  92368. ** An instance of the following object is used to read records out of a

  92369. ** PMA, in sorted order.  The next key to be read is cached in nKey/aKey.

  92370. ** aKey might point into aMap or into aBuffer.  If neither of those locations

  92371. ** contain a contiguous representation of the key, then aAlloc is allocated

  92372. ** and the key is copied into aAlloc and aKey is made to poitn to aAlloc.

  92373. **

  92374. ** pFd==0 at EOF.

  92375. */

  92376. struct PmaReader {

  92377.   i64 iReadOff;               /* Current read offset */

  92378.   i64 iEof;                   /* 1 byte past EOF for this PmaReader */

  92379.   int nAlloc;                 /* Bytes of space at aAlloc */

  92380.   int nKey;                   /* Number of bytes in key */

  92381.   sqlite3_file *pFd;          /* File handle we are reading from */

  92382.   u8 *aAlloc;                 /* Space for aKey if aBuffer and pMap wont work */

  92383.   u8 *aKey;                   /* Pointer to current key */

  92384.   u8 *aBuffer;                /* Current read buffer */

  92385.   int nBuffer;                /* Size of read buffer in bytes */

  92386.   u8 *aMap;                   /* Pointer to mapping of entire file */

  92387.   IncrMerger *pIncr;          /* Incremental merger */

  92388. };

  92389. 

  92390. /*

  92391. ** Normally, a PmaReader object iterates through an existing PMA stored 

  92392. ** within a temp file. However, if the PmaReader.pIncr variable points to

  92393. ** an object of the following type, it may be used to iterate/merge through

  92394. ** multiple PMAs simultaneously.

  92395. **

  92396. ** There are two types of IncrMerger object - single (bUseThread==0) and 

  92397. ** multi-threaded (bUseThread==1). 

  92398. **

  92399. ** A multi-threaded IncrMerger object uses two temporary files - aFile[0] 

  92400. ** and aFile[1]. Neither file is allowed to grow to more than mxSz bytes in 

  92401. ** size. When the IncrMerger is initialized, it reads enough data from 

  92402. ** pMerger to populate aFile[0]. It then sets variables within the 

  92403. ** corresponding PmaReader object to read from that file and kicks off 

  92404. ** a background thread to populate aFile[1] with the next mxSz bytes of 

  92405. ** sorted record data from pMerger. 

  92406. **

  92407. ** When the PmaReader reaches the end of aFile[0], it blocks until the

  92408. ** background thread has finished populating aFile[1]. It then exchanges

  92409. ** the contents of the aFile[0] and aFile[1] variables within this structure,

  92410. ** sets the PmaReader fields to read from the new aFile[0] and kicks off

  92411. ** another background thread to populate the new aFile[1]. And so on, until

  92412. ** the contents of pMerger are exhausted.

  92413. **

  92414. ** A single-threaded IncrMerger does not open any temporary files of its

  92415. ** own. Instead, it has exclusive access to mxSz bytes of space beginning

  92416. ** at offset iStartOff of file pTask->file2. And instead of using a 

  92417. ** background thread to prepare data for the PmaReader, with a single

  92418. ** threaded IncrMerger the allocate part of pTask->file2 is "refilled" with

  92419. ** keys from pMerger by the calling thread whenever the PmaReader runs out

  92420. ** of data.

  92421. */

  92422. struct IncrMerger {

  92423.   SortSubtask *pTask;             /* Task that owns this merger */

  92424.   MergeEngine *pMerger;           /* Merge engine thread reads data from */

  92425.   i64 iStartOff;                  /* Offset to start writing file at */

  92426.   int mxSz;                       /* Maximum bytes of data to store */

  92427.   int bEof;                       /* Set to true when merge is finished */

  92428.   int bUseThread;                 /* True to use a bg thread for this object */

  92429.   SorterFile aFile[2];            /* aFile[0] for reading, [1] for writing */

  92430. };

  92431. 

  92432. /*

  92433. ** An instance of this object is used for writing a PMA.

  92434. **

  92435. ** The PMA is written one record at a time.  Each record is of an arbitrary

  92436. ** size.  But I/O is more efficient if it occurs in page-sized blocks where

  92437. ** each block is aligned on a page boundary.  This object caches writes to

  92438. ** the PMA so that aligned, page-size blocks are written.

  92439. */

  92440. struct PmaWriter {

  92441.   int eFWErr;                     /* Non-zero if in an error state */

  92442.   u8 *aBuffer;                    /* Pointer to write buffer */

  92443.   int nBuffer;                    /* Size of write buffer in bytes */

  92444.   int iBufStart;                  /* First byte of buffer to write */

  92445.   int iBufEnd;                    /* Last byte of buffer to write */

  92446.   i64 iWriteOff;                  /* Offset of start of buffer in file */

  92447.   sqlite3_file *pFd;              /* File handle to write to */

  92448. };

  92449. 

  92450. /*

  92451. ** This object is the header on a single record while that record is being

  92452. ** held in memory and prior to being written out as part of a PMA.

  92453. **

  92454. ** How the linked list is connected depends on how memory is being managed

  92455. ** by this module. If using a separate allocation for each in-memory record

  92456. ** (VdbeSorter.list.aMemory==0), then the list is always connected using the

  92457. ** SorterRecord.u.pNext pointers.

  92458. **

  92459. ** Or, if using the single large allocation method (VdbeSorter.list.aMemory!=0),

  92460. ** then while records are being accumulated the list is linked using the

  92461. ** SorterRecord.u.iNext offset. This is because the aMemory[] array may

  92462. ** be sqlite3Realloc()ed while records are being accumulated. Once the VM

  92463. ** has finished passing records to the sorter, or when the in-memory buffer

  92464. ** is full, the list is sorted. As part of the sorting process, it is

  92465. ** converted to use the SorterRecord.u.pNext pointers. See function

  92466. ** vdbeSorterSort() for details.

  92467. */

  92468. struct SorterRecord {

  92469.   int nVal;                       /* Size of the record in bytes */

  92470.   union {

  92471.     SorterRecord *pNext;          /* Pointer to next record in list */

  92472.     int iNext;                    /* Offset within aMemory of next record */

  92473.   } u;

  92474.   /* The data for the record immediately follows this header */

  92475. };

  92476. 

  92477. /* Return a pointer to the buffer containing the record data for SorterRecord

  92478. ** object p. Should be used as if:

  92479. **

  92480. **   void *SRVAL(SorterRecord *p) { return (void*)&p[1]; }

  92481. */

  92482. #define SRVAL(p) ((void*)((SorterRecord*)(p) + 1))

  92483. 

  92484. 

  92485. /* Maximum number of PMAs that a single MergeEngine can merge */

  92486. #define SORTER_MAX_MERGE_COUNT 16

  92487. 

  92488. static int vdbeIncrSwap(IncrMerger*);

  92489. static void vdbeIncrFree(IncrMerger *);

  92490. 

  92491. /*

  92492. ** Free all memory belonging to the PmaReader object passed as the

  92493. ** argument. All structure fields are set to zero before returning.

  92494. */

  92495. static void vdbePmaReaderClear(PmaReader *pReadr){

  92496.   sqlite3_free(pReadr->aAlloc);

  92497.   sqlite3_free(pReadr->aBuffer);

  92498.   if( pReadr->aMap ) sqlite3OsUnfetch(pReadr->pFd, 0, pReadr->aMap);

  92499.   vdbeIncrFree(pReadr->pIncr);

  92500.   memset(pReadr, 0, sizeof(PmaReader));

  92501. }

  92502. 

  92503. /*

  92504. ** Read the next nByte bytes of data from the PMA p.

  92505. ** If successful, set *ppOut to point to a buffer containing the data

  92506. ** and return SQLITE_OK. Otherwise, if an error occurs, return an SQLite

  92507. ** error code.

  92508. **

  92509. ** The buffer returned in *ppOut is only valid until the

  92510. ** next call to this function.

  92511. */

  92512. static int vdbePmaReadBlob(

  92513.   PmaReader *p,                   /* PmaReader from which to take the blob */

  92514.   int nByte,                      /* Bytes of data to read */

  92515.   u8 **ppOut                      /* OUT: Pointer to buffer containing data */

  92516. ){

  92517.   int iBuf;                       /* Offset within buffer to read from */

  92518.   int nAvail;                     /* Bytes of data available in buffer */

  92519. 

  92520.   if( p->aMap ){

  92521.     *ppOut = &p->aMap[p->iReadOff];

  92522.     p->iReadOff += nByte;

  92523.     return SQLITE_OK;

  92524.   }

  92525. 

  92526.   assert( p->aBuffer );

  92527. 

  92528.   /* If there is no more data to be read from the buffer, read the next 

  92529.   ** p->nBuffer bytes of data from the file into it. Or, if there are less

  92530.   ** than p->nBuffer bytes remaining in the PMA, read all remaining data.  */

  92531.   iBuf = p->iReadOff % p->nBuffer;

  92532.   if( iBuf==0 ){

  92533.     int nRead;                    /* Bytes to read from disk */

  92534.     int rc;                       /* sqlite3OsRead() return code */

  92535. 

  92536.     /* Determine how many bytes of data to read. */

  92537.     if( (p->iEof - p->iReadOff) > (i64)p->nBuffer ){

  92538.       nRead = p->nBuffer;

  92539.     }else{

  92540.       nRead = (int)(p->iEof - p->iReadOff);

  92541.     }

  92542.     assert( nRead>0 );

  92543. 

  92544.     /* Readr data from the file. Return early if an error occurs. */

  92545.     rc = sqlite3OsRead(p->pFd, p->aBuffer, nRead, p->iReadOff);

  92546.     assert( rc!=SQLITE_IOERR_SHORT_READ );

  92547.     if( rc!=SQLITE_OK ) return rc;

  92548.   }

  92549.   nAvail = p->nBuffer - iBuf; 

  92550. 

  92551.   if( nByte<=nAvail ){

  92552.     /* The requested data is available in the in-memory buffer. In this

  92553.     ** case there is no need to make a copy of the data, just return a 

  92554.     ** pointer into the buffer to the caller.  */

  92555.     *ppOut = &p->aBuffer[iBuf];

  92556.     p->iReadOff += nByte;

  92557.   }else{

  92558.     /* The requested data is not all available in the in-memory buffer.

  92559.     ** In this case, allocate space at p->aAlloc[] to copy the requested

  92560.     ** range into. Then return a copy of pointer p->aAlloc to the caller.  */

  92561.     int nRem;                     /* Bytes remaining to copy */

  92562. 

  92563.     /* Extend the p->aAlloc[] allocation if required. */

  92564.     if( p->nAlloc<nByte ){

  92565.       u8 *aNew;

  92566.       sqlite3_int64 nNew = MAX(128, 2*(sqlite3_int64)p->nAlloc);

  92567.       while( nByte>nNew ) nNew = nNew*2;

  92568.       aNew = sqlite3Realloc(p->aAlloc, nNew);

  92569.       if( !aNew ) return SQLITE_NOMEM_BKPT;

  92570.       p->nAlloc = nNew;

  92571.       p->aAlloc = aNew;

  92572.     }

  92573. 

  92574.     /* Copy as much data as is available in the buffer into the start of

  92575.     ** p->aAlloc[].  */

  92576.     memcpy(p->aAlloc, &p->aBuffer[iBuf], nAvail);

  92577.     p->iReadOff += nAvail;

  92578.     nRem = nByte - nAvail;

  92579. 

  92580.     /* The following loop copies up to p->nBuffer bytes per iteration into

  92581.     ** the p->aAlloc[] buffer.  */

  92582.     while( nRem>0 ){

  92583.       int rc;                     /* vdbePmaReadBlob() return code */

  92584.       int nCopy;                  /* Number of bytes to copy */

  92585.       u8 *aNext;                  /* Pointer to buffer to copy data from */

  92586. 

  92587.       nCopy = nRem;

  92588.       if( nRem>p->nBuffer ) nCopy = p->nBuffer;

  92589.       rc = vdbePmaReadBlob(p, nCopy, &aNext);

  92590.       if( rc!=SQLITE_OK ) return rc;

  92591.       assert( aNext!=p->aAlloc );

  92592.       memcpy(&p->aAlloc[nByte - nRem], aNext, nCopy);

  92593.       nRem -= nCopy;

  92594.     }

  92595. 

  92596.     *ppOut = p->aAlloc;

  92597.   }

  92598. 

  92599.   return SQLITE_OK;

  92600. }

  92601. 

  92602. /*

  92603. ** Read a varint from the stream of data accessed by p. Set *pnOut to

  92604. ** the value read.

  92605. */

  92606. static int vdbePmaReadVarint(PmaReader *p, u64 *pnOut){

  92607.   int iBuf;

  92608. 

  92609.   if( p->aMap ){

  92610.     p->iReadOff += sqlite3GetVarint(&p->aMap[p->iReadOff], pnOut);

  92611.   }else{

  92612.     iBuf = p->iReadOff % p->nBuffer;

  92613.     if( iBuf && (p->nBuffer-iBuf)>=9 ){

  92614.       p->iReadOff += sqlite3GetVarint(&p->aBuffer[iBuf], pnOut);

  92615.     }else{

  92616.       u8 aVarint[16], *a;

  92617.       int i = 0, rc;

  92618.       do{

  92619.         rc = vdbePmaReadBlob(p, 1, &a);

  92620.         if( rc ) return rc;

  92621.         aVarint[(i++)&0xf] = a[0];

  92622.       }while( (a[0]&0x80)!=0 );

  92623.       sqlite3GetVarint(aVarint, pnOut);

  92624.     }

  92625.   }

  92626. 

  92627.   return SQLITE_OK;

  92628. }

  92629. 

  92630. /*

  92631. ** Attempt to memory map file pFile. If successful, set *pp to point to the

  92632. ** new mapping and return SQLITE_OK. If the mapping is not attempted 

  92633. ** (because the file is too large or the VFS layer is configured not to use

  92634. ** mmap), return SQLITE_OK and set *pp to NULL.

  92635. **

  92636. ** Or, if an error occurs, return an SQLite error code. The final value of

  92637. ** *pp is undefined in this case.

  92638. */

  92639. static int vdbeSorterMapFile(SortSubtask *pTask, SorterFile *pFile, u8 **pp){

  92640.   int rc = SQLITE_OK;

  92641.   if( pFile->iEof<=(i64)(pTask->pSorter->db->nMaxSorterMmap) ){

  92642.     sqlite3_file *pFd = pFile->pFd;

  92643.     if( pFd->pMethods->iVersion>=3 ){

  92644.       rc = sqlite3OsFetch(pFd, 0, (int)pFile->iEof, (void**)pp);

  92645.       testcase( rc!=SQLITE_OK );

  92646.     }

  92647.   }

  92648.   return rc;

  92649. }

  92650. 

  92651. /*

  92652. ** Attach PmaReader pReadr to file pFile (if it is not already attached to

  92653. ** that file) and seek it to offset iOff within the file.  Return SQLITE_OK 

  92654. ** if successful, or an SQLite error code if an error occurs.

  92655. */

  92656. static int vdbePmaReaderSeek(

  92657.   SortSubtask *pTask,             /* Task context */

  92658.   PmaReader *pReadr,              /* Reader whose cursor is to be moved */

  92659.   SorterFile *pFile,              /* Sorter file to read from */

  92660.   i64 iOff                        /* Offset in pFile */

  92661. ){

  92662.   int rc = SQLITE_OK;

  92663. 

  92664.   assert( pReadr->pIncr==0 || pReadr->pIncr->bEof==0 );

  92665. 

  92666.   if( sqlite3FaultSim(201) ) return SQLITE_IOERR_READ;

  92667.   if( pReadr->aMap ){

  92668.     sqlite3OsUnfetch(pReadr->pFd, 0, pReadr->aMap);

  92669.     pReadr->aMap = 0;

  92670.   }

  92671.   pReadr->iReadOff = iOff;

  92672.   pReadr->iEof = pFile->iEof;

  92673.   pReadr->pFd = pFile->pFd;

  92674. 

  92675.   rc = vdbeSorterMapFile(pTask, pFile, &pReadr->aMap);

  92676.   if( rc==SQLITE_OK && pReadr->aMap==0 ){

  92677.     int pgsz = pTask->pSorter->pgsz;

  92678.     int iBuf = pReadr->iReadOff % pgsz;

  92679.     if( pReadr->aBuffer==0 ){

  92680.       pReadr->aBuffer = (u8*)sqlite3Malloc(pgsz);

  92681.       if( pReadr->aBuffer==0 ) rc = SQLITE_NOMEM_BKPT;

  92682.       pReadr->nBuffer = pgsz;

  92683.     }

  92684.     if( rc==SQLITE_OK && iBuf ){

  92685.       int nRead = pgsz - iBuf;

  92686.       if( (pReadr->iReadOff + nRead) > pReadr->iEof ){

  92687.         nRead = (int)(pReadr->iEof - pReadr->iReadOff);

  92688.       }

  92689.       rc = sqlite3OsRead(

  92690.           pReadr->pFd, &pReadr->aBuffer[iBuf], nRead, pReadr->iReadOff

  92691.       );

  92692.       testcase( rc!=SQLITE_OK );

  92693.     }

  92694.   }

  92695. 

  92696.   return rc;

  92697. }

  92698. 

  92699. /*

  92700. ** Advance PmaReader pReadr to the next key in its PMA. Return SQLITE_OK if

  92701. ** no error occurs, or an SQLite error code if one does.

  92702. */

  92703. static int vdbePmaReaderNext(PmaReader *pReadr){

  92704.   int rc = SQLITE_OK;             /* Return Code */

  92705.   u64 nRec = 0;                   /* Size of record in bytes */

  92706. 

  92707. 

  92708.   if( pReadr->iReadOff>=pReadr->iEof ){

  92709.     IncrMerger *pIncr = pReadr->pIncr;

  92710.     int bEof = 1;

  92711.     if( pIncr ){

  92712.       rc = vdbeIncrSwap(pIncr);

  92713.       if( rc==SQLITE_OK && pIncr->bEof==0 ){

  92714.         rc = vdbePmaReaderSeek(

  92715.             pIncr->pTask, pReadr, &pIncr->aFile[0], pIncr->iStartOff

  92716.         );

  92717.         bEof = 0;

  92718.       }

  92719.     }

  92720. 

  92721.     if( bEof ){

  92722.       /* This is an EOF condition */

  92723.       vdbePmaReaderClear(pReadr);

  92724.       testcase( rc!=SQLITE_OK );

  92725.       return rc;

  92726.     }

  92727.   }

  92728. 

  92729.   if( rc==SQLITE_OK ){

  92730.     rc = vdbePmaReadVarint(pReadr, &nRec);

  92731.   }

  92732.   if( rc==SQLITE_OK ){

  92733.     pReadr->nKey = (int)nRec;

  92734.     rc = vdbePmaReadBlob(pReadr, (int)nRec, &pReadr->aKey);

  92735.     testcase( rc!=SQLITE_OK );

  92736.   }

  92737. 

  92738.   return rc;

  92739. }

  92740. 

  92741. /*

  92742. ** Initialize PmaReader pReadr to scan through the PMA stored in file pFile

  92743. ** starting at offset iStart and ending at offset iEof-1. This function 

  92744. ** leaves the PmaReader pointing to the first key in the PMA (or EOF if the 

  92745. ** PMA is empty).

  92746. **

  92747. ** If the pnByte parameter is NULL, then it is assumed that the file 

  92748. ** contains a single PMA, and that that PMA omits the initial length varint.

  92749. */

  92750. static int vdbePmaReaderInit(

  92751.   SortSubtask *pTask,             /* Task context */

  92752.   SorterFile *pFile,              /* Sorter file to read from */

  92753.   i64 iStart,                     /* Start offset in pFile */

  92754.   PmaReader *pReadr,              /* PmaReader to populate */

  92755.   i64 *pnByte                     /* IN/OUT: Increment this value by PMA size */

  92756. ){

  92757.   int rc;

  92758. 

  92759.   assert( pFile->iEof>iStart );

  92760.   assert( pReadr->aAlloc==0 && pReadr->nAlloc==0 );

  92761.   assert( pReadr->aBuffer==0 );

  92762.   assert( pReadr->aMap==0 );

  92763. 

  92764.   rc = vdbePmaReaderSeek(pTask, pReadr, pFile, iStart);

  92765.   if( rc==SQLITE_OK ){

  92766.     u64 nByte = 0;                 /* Size of PMA in bytes */

  92767.     rc = vdbePmaReadVarint(pReadr, &nByte);

  92768.     pReadr->iEof = pReadr->iReadOff + nByte;

  92769.     *pnByte += nByte;

  92770.   }

  92771. 

  92772.   if( rc==SQLITE_OK ){

  92773.     rc = vdbePmaReaderNext(pReadr);

  92774.   }

  92775.   return rc;

  92776. }

  92777. 

  92778. /*

  92779. ** A version of vdbeSorterCompare() that assumes that it has already been

  92780. ** determined that the first field of key1 is equal to the first field of 

  92781. ** key2.

  92782. */

  92783. static int vdbeSorterCompareTail(

  92784.   SortSubtask *pTask,             /* Subtask context (for pKeyInfo) */

  92785.   int *pbKey2Cached,              /* True if pTask->pUnpacked is pKey2 */

  92786.   const void *pKey1, int nKey1,   /* Left side of comparison */

  92787.   const void *pKey2, int nKey2    /* Right side of comparison */

  92788. ){

  92789.   UnpackedRecord *r2 = pTask->pUnpacked;

  92790.   if( *pbKey2Cached==0 ){

  92791.     sqlite3VdbeRecordUnpack(pTask->pSorter->pKeyInfo, nKey2, pKey2, r2);

  92792.     *pbKey2Cached = 1;

  92793.   }

  92794.   return sqlite3VdbeRecordCompareWithSkip(nKey1, pKey1, r2, 1);

  92795. }

  92796. 

  92797. /*

  92798. ** Compare key1 (buffer pKey1, size nKey1 bytes) with key2 (buffer pKey2, 

  92799. ** size nKey2 bytes). Use (pTask->pKeyInfo) for the collation sequences

  92800. ** used by the comparison. Return the result of the comparison.

  92801. **

  92802. ** If IN/OUT parameter *pbKey2Cached is true when this function is called,

  92803. ** it is assumed that (pTask->pUnpacked) contains the unpacked version

  92804. ** of key2. If it is false, (pTask->pUnpacked) is populated with the unpacked

  92805. ** version of key2 and *pbKey2Cached set to true before returning.

  92806. **

  92807. ** If an OOM error is encountered, (pTask->pUnpacked->error_rc) is set

  92808. ** to SQLITE_NOMEM.

  92809. */

  92810. static int vdbeSorterCompare(

  92811.   SortSubtask *pTask,             /* Subtask context (for pKeyInfo) */

  92812.   int *pbKey2Cached,              /* True if pTask->pUnpacked is pKey2 */

  92813.   const void *pKey1, int nKey1,   /* Left side of comparison */

  92814.   const void *pKey2, int nKey2    /* Right side of comparison */

  92815. ){

  92816.   UnpackedRecord *r2 = pTask->pUnpacked;

  92817.   if( !*pbKey2Cached ){

  92818.     sqlite3VdbeRecordUnpack(pTask->pSorter->pKeyInfo, nKey2, pKey2, r2);

  92819.     *pbKey2Cached = 1;

  92820.   }

  92821.   return sqlite3VdbeRecordCompare(nKey1, pKey1, r2);

  92822. }

  92823. 

  92824. /*

  92825. ** A specially optimized version of vdbeSorterCompare() that assumes that

  92826. ** the first field of each key is a TEXT value and that the collation

  92827. ** sequence to compare them with is BINARY.

  92828. */

  92829. static int vdbeSorterCompareText(

  92830.   SortSubtask *pTask,             /* Subtask context (for pKeyInfo) */

  92831.   int *pbKey2Cached,              /* True if pTask->pUnpacked is pKey2 */

  92832.   const void *pKey1, int nKey1,   /* Left side of comparison */

  92833.   const void *pKey2, int nKey2    /* Right side of comparison */

  92834. ){

  92835.   const u8 * const p1 = (const u8 * const)pKey1;

  92836.   const u8 * const p2 = (const u8 * const)pKey2;

  92837.   const u8 * const v1 = &p1[ p1[0] ];   /* Pointer to value 1 */

  92838.   const u8 * const v2 = &p2[ p2[0] ];   /* Pointer to value 2 */

  92839. 

  92840.   int n1;

  92841.   int n2;

  92842.   int res;

  92843. 

  92844.   getVarint32(&p1[1], n1);

  92845.   getVarint32(&p2[1], n2);

  92846.   res = memcmp(v1, v2, (MIN(n1, n2) - 13)/2);

  92847.   if( res==0 ){

  92848.     res = n1 - n2;

  92849.   }

  92850. 

  92851.   if( res==0 ){

  92852.     if( pTask->pSorter->pKeyInfo->nKeyField>1 ){

  92853.       res = vdbeSorterCompareTail(

  92854.           pTask, pbKey2Cached, pKey1, nKey1, pKey2, nKey2

  92855.       );

  92856.     }

  92857.   }else{

  92858.     if( pTask->pSorter->pKeyInfo->aSortOrder[0] ){

  92859.       res = res * -1;

  92860.     }

  92861.   }

  92862. 

  92863.   return res;

  92864. }

  92865. 

  92866. /*

  92867. ** A specially optimized version of vdbeSorterCompare() that assumes that

  92868. ** the first field of each key is an INTEGER value.

  92869. */

  92870. static int vdbeSorterCompareInt(

  92871.   SortSubtask *pTask,             /* Subtask context (for pKeyInfo) */

  92872.   int *pbKey2Cached,              /* True if pTask->pUnpacked is pKey2 */

  92873.   const void *pKey1, int nKey1,   /* Left side of comparison */

  92874.   const void *pKey2, int nKey2    /* Right side of comparison */

  92875. ){

  92876.   const u8 * const p1 = (const u8 * const)pKey1;

  92877.   const u8 * const p2 = (const u8 * const)pKey2;

  92878.   const int s1 = p1[1];                 /* Left hand serial type */

  92879.   const int s2 = p2[1];                 /* Right hand serial type */

  92880.   const u8 * const v1 = &p1[ p1[0] ];   /* Pointer to value 1 */

  92881.   const u8 * const v2 = &p2[ p2[0] ];   /* Pointer to value 2 */

  92882.   int res;                              /* Return value */

  92883. 

  92884.   assert( (s1>0 && s1<7) || s1==8 || s1==9 );

  92885.   assert( (s2>0 && s2<7) || s2==8 || s2==9 );

  92886. 

  92887.   if( s1==s2 ){

  92888.     /* The two values have the same sign. Compare using memcmp(). */

  92889.     static const u8 aLen[] = {0, 1, 2, 3, 4, 6, 8, 0, 0, 0 };

  92890.     const u8 n = aLen[s1];

  92891.     int i;

  92892.     res = 0;

  92893.     for(i=0; i<n; i++){

  92894.       if( (res = v1[i] - v2[i])!=0 ){

  92895.         if( ((v1[0] ^ v2[0]) & 0x80)!=0 ){

  92896.           res = v1[0] & 0x80 ? -1 : +1;

  92897.         }

  92898.         break;

  92899.       }

  92900.     }

  92901.   }else if( s1>7 && s2>7 ){

  92902.     res = s1 - s2;

  92903.   }else{

  92904.     if( s2>7 ){

  92905.       res = +1;

  92906.     }else if( s1>7 ){

  92907.       res = -1;

  92908.     }else{

  92909.       res = s1 - s2;

  92910.     }

  92911.     assert( res!=0 );

  92912. 

  92913.     if( res>0 ){

  92914.       if( *v1 & 0x80 ) res = -1;

  92915.     }else{

  92916.       if( *v2 & 0x80 ) res = +1;

  92917.     }

  92918.   }

  92919. 

  92920.   if( res==0 ){

  92921.     if( pTask->pSorter->pKeyInfo->nKeyField>1 ){

  92922.       res = vdbeSorterCompareTail(

  92923.           pTask, pbKey2Cached, pKey1, nKey1, pKey2, nKey2

  92924.       );

  92925.     }

  92926.   }else if( pTask->pSorter->pKeyInfo->aSortOrder[0] ){

  92927.     res = res * -1;

  92928.   }

  92929. 

  92930.   return res;

  92931. }

  92932. 

  92933. /*

  92934. ** Initialize the temporary index cursor just opened as a sorter cursor.

  92935. **

  92936. ** Usually, the sorter module uses the value of (pCsr->pKeyInfo->nKeyField)

  92937. ** to determine the number of fields that should be compared from the

  92938. ** records being sorted. However, if the value passed as argument nField

  92939. ** is non-zero and the sorter is able to guarantee a stable sort, nField

  92940. ** is used instead. This is used when sorting records for a CREATE INDEX

  92941. ** statement. In this case, keys are always delivered to the sorter in

  92942. ** order of the primary key, which happens to be make up the final part 

  92943. ** of the records being sorted. So if the sort is stable, there is never

  92944. ** any reason to compare PK fields and they can be ignored for a small

  92945. ** performance boost.

  92946. **

  92947. ** The sorter can guarantee a stable sort when running in single-threaded

  92948. ** mode, but not in multi-threaded mode.

  92949. **

  92950. ** SQLITE_OK is returned if successful, or an SQLite error code otherwise.

  92951. */

  92952. SQLITE_PRIVATE int sqlite3VdbeSorterInit(

  92953.   sqlite3 *db,                    /* Database connection (for malloc()) */

  92954.   int nField,                     /* Number of key fields in each record */

  92955.   VdbeCursor *pCsr                /* Cursor that holds the new sorter */

  92956. ){

  92957.   int pgsz;                       /* Page size of main database */

  92958.   int i;                          /* Used to iterate through aTask[] */

  92959.   VdbeSorter *pSorter;            /* The new sorter */

  92960.   KeyInfo *pKeyInfo;              /* Copy of pCsr->pKeyInfo with db==0 */

  92961.   int szKeyInfo;                  /* Size of pCsr->pKeyInfo in bytes */

  92962.   int sz;                         /* Size of pSorter in bytes */

  92963.   int rc = SQLITE_OK;

  92964. #if SQLITE_MAX_WORKER_THREADS==0

  92965. # define nWorker 0

  92966. #else

  92967.   int nWorker;

  92968. #endif

  92969. 

  92970.   /* Initialize the upper limit on the number of worker threads */

  92971. #if SQLITE_MAX_WORKER_THREADS>0

  92972.   if( sqlite3TempInMemory(db) || sqlite3GlobalConfig.bCoreMutex==0 ){

  92973.     nWorker = 0;

  92974.   }else{

  92975.     nWorker = db->aLimit[SQLITE_LIMIT_WORKER_THREADS];

  92976.   }

  92977. #endif

  92978. 

  92979.   /* Do not allow the total number of threads (main thread + all workers)

  92980.   ** to exceed the maximum merge count */

  92981. #if SQLITE_MAX_WORKER_THREADS>=SORTER_MAX_MERGE_COUNT

  92982.   if( nWorker>=SORTER_MAX_MERGE_COUNT ){

  92983.     nWorker = SORTER_MAX_MERGE_COUNT-1;

  92984.   }

  92985. #endif

  92986. 

  92987.   assert( pCsr->pKeyInfo && pCsr->pBtx==0 );

  92988.   assert( pCsr->eCurType==CURTYPE_SORTER );

  92989.   szKeyInfo = sizeof(KeyInfo) + (pCsr->pKeyInfo->nKeyField-1)*sizeof(CollSeq*);

  92990.   sz = sizeof(VdbeSorter) + nWorker * sizeof(SortSubtask);

  92991. 

  92992.   pSorter = (VdbeSorter*)sqlite3DbMallocZero(db, sz + szKeyInfo);

  92993.   pCsr->uc.pSorter = pSorter;

  92994.   if( pSorter==0 ){

  92995.     rc = SQLITE_NOMEM_BKPT;

  92996.   }else{

  92997.     pSorter->pKeyInfo = pKeyInfo = (KeyInfo*)((u8*)pSorter + sz);

  92998.     memcpy(pKeyInfo, pCsr->pKeyInfo, szKeyInfo);

  92999.     pKeyInfo->db = 0;

  93000.     if( nField && nWorker==0 ){

  93001.       pKeyInfo->nKeyField = nField;

  93002.     }

  93003.     pSorter->pgsz = pgsz = sqlite3BtreeGetPageSize(db->aDb[0].pBt);

  93004.     pSorter->nTask = nWorker + 1;

  93005.     pSorter->iPrev = (u8)(nWorker - 1);

  93006.     pSorter->bUseThreads = (pSorter->nTask>1);

  93007.     pSorter->db = db;

  93008.     for(i=0; i<pSorter->nTask; i++){

  93009.       SortSubtask *pTask = &pSorter->aTask[i];

  93010.       pTask->pSorter = pSorter;

  93011.     }

  93012. 

  93013.     if( !sqlite3TempInMemory(db) ){

  93014.       i64 mxCache;                /* Cache size in bytes*/

  93015.       u32 szPma = sqlite3GlobalConfig.szPma;

  93016.       pSorter->mnPmaSize = szPma * pgsz;

  93017. 

  93018.       mxCache = db->aDb[0].pSchema->cache_size;

  93019.       if( mxCache<0 ){

  93020.         /* A negative cache-size value C indicates that the cache is abs(C)

  93021.         ** KiB in size.  */

  93022.         mxCache = mxCache * -1024;

  93023.       }else{

  93024.         mxCache = mxCache * pgsz;

  93025.       }

  93026.       mxCache = MIN(mxCache, SQLITE_MAX_PMASZ);

  93027.       pSorter->mxPmaSize = MAX(pSorter->mnPmaSize, (int)mxCache);

  93028. 

  93029.       /* Avoid large memory allocations if the application has requested

  93030.       ** SQLITE_CONFIG_SMALL_MALLOC. */

  93031.       if( sqlite3GlobalConfig.bSmallMalloc==0 ){

  93032.         assert( pSorter->iMemory==0 );

  93033.         pSorter->nMemory = pgsz;

  93034.         pSorter->list.aMemory = (u8*)sqlite3Malloc(pgsz);

  93035.         if( !pSorter->list.aMemory ) rc = SQLITE_NOMEM_BKPT;

  93036.       }

  93037.     }

  93038. 

  93039.     if( pKeyInfo->nAllField<13 

  93040.      && (pKeyInfo->aColl[0]==0 || pKeyInfo->aColl[0]==db->pDfltColl)

  93041.     ){

  93042.       pSorter->typeMask = SORTER_TYPE_INTEGER | SORTER_TYPE_TEXT;

  93043.     }

  93044.   }

  93045. 

  93046.   return rc;

  93047. }

  93048. #undef nWorker   /* Defined at the top of this function */

  93049. 

  93050. /*

  93051. ** Free the list of sorted records starting at pRecord.

  93052. */

  93053. static void vdbeSorterRecordFree(sqlite3 *db, SorterRecord *pRecord){

  93054.   SorterRecord *p;

  93055.   SorterRecord *pNext;

  93056.   for(p=pRecord; p; p=pNext){

  93057.     pNext = p->u.pNext;

  93058.     sqlite3DbFree(db, p);

  93059.   }

  93060. }

  93061. 

  93062. /*

  93063. ** Free all resources owned by the object indicated by argument pTask. All 

  93064. ** fields of *pTask are zeroed before returning.

  93065. */

  93066. static void vdbeSortSubtaskCleanup(sqlite3 *db, SortSubtask *pTask){

  93067.   sqlite3DbFree(db, pTask->pUnpacked);

  93068. #if SQLITE_MAX_WORKER_THREADS>0

  93069.   /* pTask->list.aMemory can only be non-zero if it was handed memory

  93070.   ** from the main thread.  That only occurs SQLITE_MAX_WORKER_THREADS>0 */

  93071.   if( pTask->list.aMemory ){

  93072.     sqlite3_free(pTask->list.aMemory);

  93073.   }else

  93074. #endif

  93075.   {

  93076.     assert( pTask->list.aMemory==0 );

  93077.     vdbeSorterRecordFree(0, pTask->list.pList);

  93078.   }

  93079.   if( pTask->file.pFd ){

  93080.     sqlite3OsCloseFree(pTask->file.pFd);

  93081.   }

  93082.   if( pTask->file2.pFd ){

  93083.     sqlite3OsCloseFree(pTask->file2.pFd);

  93084.   }

  93085.   memset(pTask, 0, sizeof(SortSubtask));

  93086. }

  93087. 

  93088. #ifdef SQLITE_DEBUG_SORTER_THREADS

  93089. static void vdbeSorterWorkDebug(SortSubtask *pTask, const char *zEvent){

  93090.   i64 t;

  93091.   int iTask = (pTask - pTask->pSorter->aTask);

  93092.   sqlite3OsCurrentTimeInt64(pTask->pSorter->db->pVfs, &t);

  93093.   fprintf(stderr, "%lld:%d %s\n", t, iTask, zEvent);

  93094. }

  93095. static void vdbeSorterRewindDebug(const char *zEvent){

  93096.   i64 t;

  93097.   sqlite3OsCurrentTimeInt64(sqlite3_vfs_find(0), &t);

  93098.   fprintf(stderr, "%lld:X %s\n", t, zEvent);

  93099. }

  93100. static void vdbeSorterPopulateDebug(

  93101.   SortSubtask *pTask,

  93102.   const char *zEvent

  93103. ){

  93104.   i64 t;

  93105.   int iTask = (pTask - pTask->pSorter->aTask);

  93106.   sqlite3OsCurrentTimeInt64(pTask->pSorter->db->pVfs, &t);

  93107.   fprintf(stderr, "%lld:bg%d %s\n", t, iTask, zEvent);

  93108. }

  93109. static void vdbeSorterBlockDebug(

  93110.   SortSubtask *pTask,

  93111.   int bBlocked,

  93112.   const char *zEvent

  93113. ){

  93114.   if( bBlocked ){

  93115.     i64 t;

  93116.     sqlite3OsCurrentTimeInt64(pTask->pSorter->db->pVfs, &t);

  93117.     fprintf(stderr, "%lld:main %s\n", t, zEvent);

  93118.   }

  93119. }

  93120. #else

  93121. # define vdbeSorterWorkDebug(x,y)

  93122. # define vdbeSorterRewindDebug(y)

  93123. # define vdbeSorterPopulateDebug(x,y)

  93124. # define vdbeSorterBlockDebug(x,y,z)

  93125. #endif

  93126. 

  93127. #if SQLITE_MAX_WORKER_THREADS>0

  93128. /*

  93129. ** Join thread pTask->thread.

  93130. */

  93131. static int vdbeSorterJoinThread(SortSubtask *pTask){

  93132.   int rc = SQLITE_OK;

  93133.   if( pTask->pThread ){

  93134. #ifdef SQLITE_DEBUG_SORTER_THREADS

  93135.     int bDone = pTask->bDone;

  93136. #endif

  93137.     void *pRet = SQLITE_INT_TO_PTR(SQLITE_ERROR);

  93138.     vdbeSorterBlockDebug(pTask, !bDone, "enter");

  93139.     (void)sqlite3ThreadJoin(pTask->pThread, &pRet);

  93140.     vdbeSorterBlockDebug(pTask, !bDone, "exit");

  93141.     rc = SQLITE_PTR_TO_INT(pRet);

  93142.     assert( pTask->bDone==1 );

  93143.     pTask->bDone = 0;

  93144.     pTask->pThread = 0;

  93145.   }

  93146.   return rc;

  93147. }

  93148. 

  93149. /*

  93150. ** Launch a background thread to run xTask(pIn).

  93151. */

  93152. static int vdbeSorterCreateThread(

  93153.   SortSubtask *pTask,             /* Thread will use this task object */

  93154.   void *(*xTask)(void*),          /* Routine to run in a separate thread */

  93155.   void *pIn                       /* Argument passed into xTask() */

  93156. ){

  93157.   assert( pTask->pThread==0 && pTask->bDone==0 );

  93158.   return sqlite3ThreadCreate(&pTask->pThread, xTask, pIn);

  93159. }

  93160. 

  93161. /*

  93162. ** Join all outstanding threads launched by SorterWrite() to create 

  93163. ** level-0 PMAs.

  93164. */

  93165. static int vdbeSorterJoinAll(VdbeSorter *pSorter, int rcin){

  93166.   int rc = rcin;

  93167.   int i;

  93168. 

  93169.   /* This function is always called by the main user thread.

  93170.   **

  93171.   ** If this function is being called after SorterRewind() has been called, 

  93172.   ** it is possible that thread pSorter->aTask[pSorter->nTask-1].pThread

  93173.   ** is currently attempt to join one of the other threads. To avoid a race

  93174.   ** condition where this thread also attempts to join the same object, join 

  93175.   ** thread pSorter->aTask[pSorter->nTask-1].pThread first. */

  93176.   for(i=pSorter->nTask-1; i>=0; i--){

  93177.     SortSubtask *pTask = &pSorter->aTask[i];

  93178.     int rc2 = vdbeSorterJoinThread(pTask);

  93179.     if( rc==SQLITE_OK ) rc = rc2;

  93180.   }

  93181.   return rc;

  93182. }

  93183. #else

  93184. # define vdbeSorterJoinAll(x,rcin) (rcin)

  93185. # define vdbeSorterJoinThread(pTask) SQLITE_OK

  93186. #endif

  93187. 

  93188. /*

  93189. ** Allocate a new MergeEngine object capable of handling up to

  93190. ** nReader PmaReader inputs.

  93191. **

  93192. ** nReader is automatically rounded up to the next power of two.

  93193. ** nReader may not exceed SORTER_MAX_MERGE_COUNT even after rounding up.

  93194. */

  93195. static MergeEngine *vdbeMergeEngineNew(int nReader){

  93196.   int N = 2;                      /* Smallest power of two >= nReader */

  93197.   int nByte;                      /* Total bytes of space to allocate */

  93198.   MergeEngine *pNew;              /* Pointer to allocated object to return */

  93199. 

  93200.   assert( nReader<=SORTER_MAX_MERGE_COUNT );

  93201. 

  93202.   while( N<nReader ) N += N;

  93203.   nByte = sizeof(MergeEngine) + N * (sizeof(int) + sizeof(PmaReader));

  93204. 

  93205.   pNew = sqlite3FaultSim(100) ? 0 : (MergeEngine*)sqlite3MallocZero(nByte);

  93206.   if( pNew ){

  93207.     pNew->nTree = N;

  93208.     pNew->pTask = 0;

  93209.     pNew->aReadr = (PmaReader*)&pNew[1];

  93210.     pNew->aTree = (int*)&pNew->aReadr[N];

  93211.   }

  93212.   return pNew;

  93213. }

  93214. 

  93215. /*

  93216. ** Free the MergeEngine object passed as the only argument.

  93217. */

  93218. static void vdbeMergeEngineFree(MergeEngine *pMerger){

  93219.   int i;

  93220.   if( pMerger ){

  93221.     for(i=0; i<pMerger->nTree; i++){

  93222.       vdbePmaReaderClear(&pMerger->aReadr[i]);

  93223.     }

  93224.   }

  93225.   sqlite3_free(pMerger);

  93226. }

  93227. 

  93228. /*

  93229. ** Free all resources associated with the IncrMerger object indicated by

  93230. ** the first argument.

  93231. */

  93232. static void vdbeIncrFree(IncrMerger *pIncr){

  93233.   if( pIncr ){

  93234. #if SQLITE_MAX_WORKER_THREADS>0

  93235.     if( pIncr->bUseThread ){

  93236.       vdbeSorterJoinThread(pIncr->pTask);

  93237.       if( pIncr->aFile[0].pFd ) sqlite3OsCloseFree(pIncr->aFile[0].pFd);

  93238.       if( pIncr->aFile[1].pFd ) sqlite3OsCloseFree(pIncr->aFile[1].pFd);

  93239.     }

  93240. #endif

  93241.     vdbeMergeEngineFree(pIncr->pMerger);

  93242.     sqlite3_free(pIncr);

  93243.   }

  93244. }

  93245. 

  93246. /*

  93247. ** Reset a sorting cursor back to its original empty state.

  93248. */

  93249. SQLITE_PRIVATE void sqlite3VdbeSorterReset(sqlite3 *db, VdbeSorter *pSorter){

  93250.   int i;

  93251.   (void)vdbeSorterJoinAll(pSorter, SQLITE_OK);

  93252.   assert( pSorter->bUseThreads || pSorter->pReader==0 );

  93253. #if SQLITE_MAX_WORKER_THREADS>0

  93254.   if( pSorter->pReader ){

  93255.     vdbePmaReaderClear(pSorter->pReader);

  93256.     sqlite3DbFree(db, pSorter->pReader);

  93257.     pSorter->pReader = 0;

  93258.   }

  93259. #endif

  93260.   vdbeMergeEngineFree(pSorter->pMerger);

  93261.   pSorter->pMerger = 0;

  93262.   for(i=0; i<pSorter->nTask; i++){

  93263.     SortSubtask *pTask = &pSorter->aTask[i];

  93264.     vdbeSortSubtaskCleanup(db, pTask);

  93265.     pTask->pSorter = pSorter;

  93266.   }

  93267.   if( pSorter->list.aMemory==0 ){

  93268.     vdbeSorterRecordFree(0, pSorter->list.pList);

  93269.   }

  93270.   pSorter->list.pList = 0;

  93271.   pSorter->list.szPMA = 0;

  93272.   pSorter->bUsePMA = 0;

  93273.   pSorter->iMemory = 0;

  93274.   pSorter->mxKeysize = 0;

  93275.   sqlite3DbFree(db, pSorter->pUnpacked);

  93276.   pSorter->pUnpacked = 0;

  93277. }

  93278. 

  93279. /*

  93280. ** Free any cursor components allocated by sqlite3VdbeSorterXXX routines.

  93281. */

  93282. SQLITE_PRIVATE void sqlite3VdbeSorterClose(sqlite3 *db, VdbeCursor *pCsr){

  93283.   VdbeSorter *pSorter;

  93284.   assert( pCsr->eCurType==CURTYPE_SORTER );

  93285.   pSorter = pCsr->uc.pSorter;

  93286.   if( pSorter ){

  93287.     sqlite3VdbeSorterReset(db, pSorter);

  93288.     sqlite3_free(pSorter->list.aMemory);

  93289.     sqlite3DbFree(db, pSorter);

  93290.     pCsr->uc.pSorter = 0;

  93291.   }

  93292. }

  93293. 

  93294. #if SQLITE_MAX_MMAP_SIZE>0

  93295. /*

  93296. ** The first argument is a file-handle open on a temporary file. The file

  93297. ** is guaranteed to be nByte bytes or smaller in size. This function

  93298. ** attempts to extend the file to nByte bytes in size and to ensure that

  93299. ** the VFS has memory mapped it.

  93300. **

  93301. ** Whether or not the file does end up memory mapped of course depends on

  93302. ** the specific VFS implementation.

  93303. */

  93304. static void vdbeSorterExtendFile(sqlite3 *db, sqlite3_file *pFd, i64 nByte){

  93305.   if( nByte<=(i64)(db->nMaxSorterMmap) && pFd->pMethods->iVersion>=3 ){

  93306.     void *p = 0;

  93307.     int chunksize = 4*1024;

  93308.     sqlite3OsFileControlHint(pFd, SQLITE_FCNTL_CHUNK_SIZE, &chunksize);

  93309.     sqlite3OsFileControlHint(pFd, SQLITE_FCNTL_SIZE_HINT, &nByte);

  93310.     sqlite3OsFetch(pFd, 0, (int)nByte, &p);

  93311.     sqlite3OsUnfetch(pFd, 0, p);

  93312.   }

  93313. }

  93314. #else

  93315. # define vdbeSorterExtendFile(x,y,z)

  93316. #endif

  93317. 

  93318. /*

  93319. ** Allocate space for a file-handle and open a temporary file. If successful,

  93320. ** set *ppFd to point to the malloc'd file-handle and return SQLITE_OK.

  93321. ** Otherwise, set *ppFd to 0 and return an SQLite error code.

  93322. */

  93323. static int vdbeSorterOpenTempFile(

  93324.   sqlite3 *db,                    /* Database handle doing sort */

  93325.   i64 nExtend,                    /* Attempt to extend file to this size */

  93326.   sqlite3_file **ppFd

  93327. ){

  93328.   int rc;

  93329.   if( sqlite3FaultSim(202) ) return SQLITE_IOERR_ACCESS;

  93330.   rc = sqlite3OsOpenMalloc(db->pVfs, 0, ppFd,

  93331.       SQLITE_OPEN_TEMP_JOURNAL |

  93332.       SQLITE_OPEN_READWRITE    | SQLITE_OPEN_CREATE |

  93333.       SQLITE_OPEN_EXCLUSIVE    | SQLITE_OPEN_DELETEONCLOSE, &rc

  93334.   );

  93335.   if( rc==SQLITE_OK ){

  93336.     i64 max = SQLITE_MAX_MMAP_SIZE;

  93337.     sqlite3OsFileControlHint(*ppFd, SQLITE_FCNTL_MMAP_SIZE, (void*)&max);

  93338.     if( nExtend>0 ){

  93339.       vdbeSorterExtendFile(db, *ppFd, nExtend);

  93340.     }

  93341.   }

  93342.   return rc;

  93343. }

  93344. 

  93345. /*

  93346. ** If it has not already been allocated, allocate the UnpackedRecord 

  93347. ** structure at pTask->pUnpacked. Return SQLITE_OK if successful (or 

  93348. ** if no allocation was required), or SQLITE_NOMEM otherwise.

  93349. */

  93350. static int vdbeSortAllocUnpacked(SortSubtask *pTask){

  93351.   if( pTask->pUnpacked==0 ){

  93352.     pTask->pUnpacked = sqlite3VdbeAllocUnpackedRecord(pTask->pSorter->pKeyInfo);

  93353.     if( pTask->pUnpacked==0 ) return SQLITE_NOMEM_BKPT;

  93354.     pTask->pUnpacked->nField = pTask->pSorter->pKeyInfo->nKeyField;

  93355.     pTask->pUnpacked->errCode = 0;

  93356.   }

  93357.   return SQLITE_OK;

  93358. }

  93359. 

  93360. 

  93361. /*

  93362. ** Merge the two sorted lists p1 and p2 into a single list.

  93363. */

  93364. static SorterRecord *vdbeSorterMerge(

  93365.   SortSubtask *pTask,             /* Calling thread context */

  93366.   SorterRecord *p1,               /* First list to merge */

  93367.   SorterRecord *p2                /* Second list to merge */

  93368. ){

  93369.   SorterRecord *pFinal = 0;

  93370.   SorterRecord **pp = &pFinal;

  93371.   int bCached = 0;

  93372. 

  93373.   assert( p1!=0 && p2!=0 );

  93374.   for(;;){

  93375.     int res;

  93376.     res = pTask->xCompare(

  93377.         pTask, &bCached, SRVAL(p1), p1->nVal, SRVAL(p2), p2->nVal

  93378.     );

  93379. 

  93380.     if( res<=0 ){

  93381.       *pp = p1;

  93382.       pp = &p1->u.pNext;

  93383.       p1 = p1->u.pNext;

  93384.       if( p1==0 ){

  93385.         *pp = p2;

  93386.         break;

  93387.       }

  93388.     }else{

  93389.       *pp = p2;

  93390.       pp = &p2->u.pNext;

  93391.       p2 = p2->u.pNext;

  93392.       bCached = 0;

  93393.       if( p2==0 ){

  93394.         *pp = p1;

  93395.         break;

  93396.       }

  93397.     }

  93398.   }

  93399.   return pFinal;

  93400. }

  93401. 

  93402. /*

  93403. ** Return the SorterCompare function to compare values collected by the

  93404. ** sorter object passed as the only argument.

  93405. */

  93406. static SorterCompare vdbeSorterGetCompare(VdbeSorter *p){

  93407.   if( p->typeMask==SORTER_TYPE_INTEGER ){

  93408.     return vdbeSorterCompareInt;

  93409.   }else if( p->typeMask==SORTER_TYPE_TEXT ){

  93410.     return vdbeSorterCompareText; 

  93411.   }

  93412.   return vdbeSorterCompare;

  93413. }

  93414. 

  93415. /*

  93416. ** Sort the linked list of records headed at pTask->pList. Return 

  93417. ** SQLITE_OK if successful, or an SQLite error code (i.e. SQLITE_NOMEM) if 

  93418. ** an error occurs.

  93419. */

  93420. static int vdbeSorterSort(SortSubtask *pTask, SorterList *pList){

  93421.   int i;

  93422.   SorterRecord **aSlot;

  93423.   SorterRecord *p;

  93424.   int rc;

  93425. 

  93426.   rc = vdbeSortAllocUnpacked(pTask);

  93427.   if( rc!=SQLITE_OK ) return rc;

  93428. 

  93429.   p = pList->pList;

  93430.   pTask->xCompare = vdbeSorterGetCompare(pTask->pSorter);

  93431. 

  93432.   aSlot = (SorterRecord **)sqlite3MallocZero(64 * sizeof(SorterRecord *));

  93433.   if( !aSlot ){

  93434.     return SQLITE_NOMEM_BKPT;

  93435.   }

  93436. 

  93437.   while( p ){

  93438.     SorterRecord *pNext;

  93439.     if( pList->aMemory ){

  93440.       if( (u8*)p==pList->aMemory ){

  93441.         pNext = 0;

  93442.       }else{

  93443.         assert( p->u.iNext<sqlite3MallocSize(pList->aMemory) );

  93444.         pNext = (SorterRecord*)&pList->aMemory[p->u.iNext];

  93445.       }

  93446.     }else{

  93447.       pNext = p->u.pNext;

  93448.     }

  93449. 

  93450.     p->u.pNext = 0;

  93451.     for(i=0; aSlot[i]; i++){

  93452.       p = vdbeSorterMerge(pTask, p, aSlot[i]);

  93453.       aSlot[i] = 0;

  93454.     }

  93455.     aSlot[i] = p;

  93456.     p = pNext;

  93457.   }

  93458. 

  93459.   p = 0;

  93460.   for(i=0; i<64; i++){

  93461.     if( aSlot[i]==0 ) continue;

  93462.     p = p ? vdbeSorterMerge(pTask, p, aSlot[i]) : aSlot[i];

  93463.   }

  93464.   pList->pList = p;

  93465. 

  93466.   sqlite3_free(aSlot);

  93467.   assert( pTask->pUnpacked->errCode==SQLITE_OK 

  93468.        || pTask->pUnpacked->errCode==SQLITE_NOMEM 

  93469.   );

  93470.   return pTask->pUnpacked->errCode;

  93471. }

  93472. 

  93473. /*

  93474. ** Initialize a PMA-writer object.

  93475. */

  93476. static void vdbePmaWriterInit(

  93477.   sqlite3_file *pFd,              /* File handle to write to */

  93478.   PmaWriter *p,                   /* Object to populate */

  93479.   int nBuf,                       /* Buffer size */

  93480.   i64 iStart                      /* Offset of pFd to begin writing at */

  93481. ){

  93482.   memset(p, 0, sizeof(PmaWriter));

  93483.   p->aBuffer = (u8*)sqlite3Malloc(nBuf);

  93484.   if( !p->aBuffer ){

  93485.     p->eFWErr = SQLITE_NOMEM_BKPT;

  93486.   }else{

  93487.     p->iBufEnd = p->iBufStart = (iStart % nBuf);

  93488.     p->iWriteOff = iStart - p->iBufStart;

  93489.     p->nBuffer = nBuf;

  93490.     p->pFd = pFd;

  93491.   }

  93492. }

  93493. 

  93494. /*

  93495. ** Write nData bytes of data to the PMA. Return SQLITE_OK

  93496. ** if successful, or an SQLite error code if an error occurs.

  93497. */

  93498. static void vdbePmaWriteBlob(PmaWriter *p, u8 *pData, int nData){

  93499.   int nRem = nData;

  93500.   while( nRem>0 && p->eFWErr==0 ){

  93501.     int nCopy = nRem;

  93502.     if( nCopy>(p->nBuffer - p->iBufEnd) ){

  93503.       nCopy = p->nBuffer - p->iBufEnd;

  93504.     }

  93505. 

  93506.     memcpy(&p->aBuffer[p->iBufEnd], &pData[nData-nRem], nCopy);

  93507.     p->iBufEnd += nCopy;

  93508.     if( p->iBufEnd==p->nBuffer ){

  93509.       p->eFWErr = sqlite3OsWrite(p->pFd, 

  93510.           &p->aBuffer[p->iBufStart], p->iBufEnd - p->iBufStart, 

  93511.           p->iWriteOff + p->iBufStart

  93512.       );

  93513.       p->iBufStart = p->iBufEnd = 0;

  93514.       p->iWriteOff += p->nBuffer;

  93515.     }

  93516.     assert( p->iBufEnd<p->nBuffer );

  93517. 

  93518.     nRem -= nCopy;

  93519.   }

  93520. }

  93521. 

  93522. /*

  93523. ** Flush any buffered data to disk and clean up the PMA-writer object.

  93524. ** The results of using the PMA-writer after this call are undefined.

  93525. ** Return SQLITE_OK if flushing the buffered data succeeds or is not 

  93526. ** required. Otherwise, return an SQLite error code.

  93527. **

  93528. ** Before returning, set *piEof to the offset immediately following the

  93529. ** last byte written to the file.

  93530. */

  93531. static int vdbePmaWriterFinish(PmaWriter *p, i64 *piEof){

  93532.   int rc;

  93533.   if( p->eFWErr==0 && ALWAYS(p->aBuffer) && p->iBufEnd>p->iBufStart ){

  93534.     p->eFWErr = sqlite3OsWrite(p->pFd, 

  93535.         &p->aBuffer[p->iBufStart], p->iBufEnd - p->iBufStart, 

  93536.         p->iWriteOff + p->iBufStart

  93537.     );

  93538.   }

  93539.   *piEof = (p->iWriteOff + p->iBufEnd);

  93540.   sqlite3_free(p->aBuffer);

  93541.   rc = p->eFWErr;

  93542.   memset(p, 0, sizeof(PmaWriter));

  93543.   return rc;

  93544. }

  93545. 

  93546. /*

  93547. ** Write value iVal encoded as a varint to the PMA. Return 

  93548. ** SQLITE_OK if successful, or an SQLite error code if an error occurs.

  93549. */

  93550. static void vdbePmaWriteVarint(PmaWriter *p, u64 iVal){

  93551.   int nByte; 

  93552.   u8 aByte[10];

  93553.   nByte = sqlite3PutVarint(aByte, iVal);

  93554.   vdbePmaWriteBlob(p, aByte, nByte);

  93555. }

  93556. 

  93557. /*

  93558. ** Write the current contents of in-memory linked-list pList to a level-0

  93559. ** PMA in the temp file belonging to sub-task pTask. Return SQLITE_OK if 

  93560. ** successful, or an SQLite error code otherwise.

  93561. **

  93562. ** The format of a PMA is:

  93563. **

  93564. **     * A varint. This varint contains the total number of bytes of content

  93565. **       in the PMA (not including the varint itself).

  93566. **

  93567. **     * One or more records packed end-to-end in order of ascending keys. 

  93568. **       Each record consists of a varint followed by a blob of data (the 

  93569. **       key). The varint is the number of bytes in the blob of data.

  93570. */

  93571. static int vdbeSorterListToPMA(SortSubtask *pTask, SorterList *pList){

  93572.   sqlite3 *db = pTask->pSorter->db;

  93573.   int rc = SQLITE_OK;             /* Return code */

  93574.   PmaWriter writer;               /* Object used to write to the file */

  93575. 

  93576. #ifdef SQLITE_DEBUG

  93577.   /* Set iSz to the expected size of file pTask->file after writing the PMA. 

  93578.   ** This is used by an assert() statement at the end of this function.  */

  93579.   i64 iSz = pList->szPMA + sqlite3VarintLen(pList->szPMA) + pTask->file.iEof;

  93580. #endif

  93581. 

  93582.   vdbeSorterWorkDebug(pTask, "enter");

  93583.   memset(&writer, 0, sizeof(PmaWriter));

  93584.   assert( pList->szPMA>0 );

  93585. 

  93586.   /* If the first temporary PMA file has not been opened, open it now. */

  93587.   if( pTask->file.pFd==0 ){

  93588.     rc = vdbeSorterOpenTempFile(db, 0, &pTask->file.pFd);

  93589.     assert( rc!=SQLITE_OK || pTask->file.pFd );

  93590.     assert( pTask->file.iEof==0 );

  93591.     assert( pTask->nPMA==0 );

  93592.   }

  93593. 

  93594.   /* Try to get the file to memory map */

  93595.   if( rc==SQLITE_OK ){

  93596.     vdbeSorterExtendFile(db, pTask->file.pFd, pTask->file.iEof+pList->szPMA+9);

  93597.   }

  93598. 

  93599.   /* Sort the list */

  93600.   if( rc==SQLITE_OK ){

  93601.     rc = vdbeSorterSort(pTask, pList);

  93602.   }

  93603. 

  93604.   if( rc==SQLITE_OK ){

  93605.     SorterRecord *p;

  93606.     SorterRecord *pNext = 0;

  93607. 

  93608.     vdbePmaWriterInit(pTask->file.pFd, &writer, pTask->pSorter->pgsz,

  93609.                       pTask->file.iEof);

  93610.     pTask->nPMA++;

  93611.     vdbePmaWriteVarint(&writer, pList->szPMA);

  93612.     for(p=pList->pList; p; p=pNext){

  93613.       pNext = p->u.pNext;

  93614.       vdbePmaWriteVarint(&writer, p->nVal);

  93615.       vdbePmaWriteBlob(&writer, SRVAL(p), p->nVal);

  93616.       if( pList->aMemory==0 ) sqlite3_free(p);

  93617.     }

  93618.     pList->pList = p;

  93619.     rc = vdbePmaWriterFinish(&writer, &pTask->file.iEof);

  93620.   }

  93621. 

  93622.   vdbeSorterWorkDebug(pTask, "exit");

  93623.   assert( rc!=SQLITE_OK || pList->pList==0 );

  93624.   assert( rc!=SQLITE_OK || pTask->file.iEof==iSz );

  93625.   return rc;

  93626. }

  93627. 

  93628. /*

  93629. ** Advance the MergeEngine to its next entry.

  93630. ** Set *pbEof to true there is no next entry because

  93631. ** the MergeEngine has reached the end of all its inputs.

  93632. **

  93633. ** Return SQLITE_OK if successful or an error code if an error occurs.

  93634. */

  93635. static int vdbeMergeEngineStep(

  93636.   MergeEngine *pMerger,      /* The merge engine to advance to the next row */

  93637.   int *pbEof                 /* Set TRUE at EOF.  Set false for more content */

  93638. ){

  93639.   int rc;

  93640.   int iPrev = pMerger->aTree[1];/* Index of PmaReader to advance */

  93641.   SortSubtask *pTask = pMerger->pTask;

  93642. 

  93643.   /* Advance the current PmaReader */

  93644.   rc = vdbePmaReaderNext(&pMerger->aReadr[iPrev]);

  93645. 

  93646.   /* Update contents of aTree[] */

  93647.   if( rc==SQLITE_OK ){

  93648.     int i;                      /* Index of aTree[] to recalculate */

  93649.     PmaReader *pReadr1;         /* First PmaReader to compare */

  93650.     PmaReader *pReadr2;         /* Second PmaReader to compare */

  93651.     int bCached = 0;

  93652. 

  93653.     /* Find the first two PmaReaders to compare. The one that was just

  93654.     ** advanced (iPrev) and the one next to it in the array.  */

  93655.     pReadr1 = &pMerger->aReadr[(iPrev & 0xFFFE)];

  93656.     pReadr2 = &pMerger->aReadr[(iPrev | 0x0001)];

  93657. 

  93658.     for(i=(pMerger->nTree+iPrev)/2; i>0; i=i/2){

  93659.       /* Compare pReadr1 and pReadr2. Store the result in variable iRes. */

  93660.       int iRes;

  93661.       if( pReadr1->pFd==0 ){

  93662.         iRes = +1;

  93663.       }else if( pReadr2->pFd==0 ){

  93664.         iRes = -1;

  93665.       }else{

  93666.         iRes = pTask->xCompare(pTask, &bCached,

  93667.             pReadr1->aKey, pReadr1->nKey, pReadr2->aKey, pReadr2->nKey

  93668.         );

  93669.       }

  93670. 

  93671.       /* If pReadr1 contained the smaller value, set aTree[i] to its index.

  93672.       ** Then set pReadr2 to the next PmaReader to compare to pReadr1. In this

  93673.       ** case there is no cache of pReadr2 in pTask->pUnpacked, so set

  93674.       ** pKey2 to point to the record belonging to pReadr2.

  93675.       **

  93676.       ** Alternatively, if pReadr2 contains the smaller of the two values,

  93677.       ** set aTree[i] to its index and update pReadr1. If vdbeSorterCompare()

  93678.       ** was actually called above, then pTask->pUnpacked now contains

  93679.       ** a value equivalent to pReadr2. So set pKey2 to NULL to prevent

  93680.       ** vdbeSorterCompare() from decoding pReadr2 again.

  93681.       **

  93682.       ** If the two values were equal, then the value from the oldest

  93683.       ** PMA should be considered smaller. The VdbeSorter.aReadr[] array

  93684.       ** is sorted from oldest to newest, so pReadr1 contains older values

  93685.       ** than pReadr2 iff (pReadr1<pReadr2).  */

  93686.       if( iRes<0 || (iRes==0 && pReadr1<pReadr2) ){

  93687.         pMerger->aTree[i] = (int)(pReadr1 - pMerger->aReadr);

  93688.         pReadr2 = &pMerger->aReadr[ pMerger->aTree[i ^ 0x0001] ];

  93689.         bCached = 0;

  93690.       }else{

  93691.         if( pReadr1->pFd ) bCached = 0;

  93692.         pMerger->aTree[i] = (int)(pReadr2 - pMerger->aReadr);

  93693.         pReadr1 = &pMerger->aReadr[ pMerger->aTree[i ^ 0x0001] ];

  93694.       }

  93695.     }

  93696.     *pbEof = (pMerger->aReadr[pMerger->aTree[1]].pFd==0);

  93697.   }

  93698. 

  93699.   return (rc==SQLITE_OK ? pTask->pUnpacked->errCode : rc);

  93700. }

  93701. 

  93702. #if SQLITE_MAX_WORKER_THREADS>0

  93703. /*

  93704. ** The main routine for background threads that write level-0 PMAs.

  93705. */

  93706. static void *vdbeSorterFlushThread(void *pCtx){

  93707.   SortSubtask *pTask = (SortSubtask*)pCtx;

  93708.   int rc;                         /* Return code */

  93709.   assert( pTask->bDone==0 );

  93710.   rc = vdbeSorterListToPMA(pTask, &pTask->list);

  93711.   pTask->bDone = 1;

  93712.   return SQLITE_INT_TO_PTR(rc);

  93713. }

  93714. #endif /* SQLITE_MAX_WORKER_THREADS>0 */

  93715. 

  93716. /*

  93717. ** Flush the current contents of VdbeSorter.list to a new PMA, possibly

  93718. ** using a background thread.

  93719. */

  93720. static int vdbeSorterFlushPMA(VdbeSorter *pSorter){

  93721. #if SQLITE_MAX_WORKER_THREADS==0

  93722.   pSorter->bUsePMA = 1;

  93723.   return vdbeSorterListToPMA(&pSorter->aTask[0], &pSorter->list);

  93724. #else

  93725.   int rc = SQLITE_OK;

  93726.   int i;

  93727.   SortSubtask *pTask = 0;    /* Thread context used to create new PMA */

  93728.   int nWorker = (pSorter->nTask-1);

  93729. 

  93730.   /* Set the flag to indicate that at least one PMA has been written. 

  93731.   ** Or will be, anyhow.  */

  93732.   pSorter->bUsePMA = 1;

  93733. 

  93734.   /* Select a sub-task to sort and flush the current list of in-memory

  93735.   ** records to disk. If the sorter is running in multi-threaded mode,

  93736.   ** round-robin between the first (pSorter->nTask-1) tasks. Except, if

  93737.   ** the background thread from a sub-tasks previous turn is still running,

  93738.   ** skip it. If the first (pSorter->nTask-1) sub-tasks are all still busy,

  93739.   ** fall back to using the final sub-task. The first (pSorter->nTask-1)

  93740.   ** sub-tasks are prefered as they use background threads - the final 

  93741.   ** sub-task uses the main thread. */

  93742.   for(i=0; i<nWorker; i++){

  93743.     int iTest = (pSorter->iPrev + i + 1) % nWorker;

  93744.     pTask = &pSorter->aTask[iTest];

  93745.     if( pTask->bDone ){

  93746.       rc = vdbeSorterJoinThread(pTask);

  93747.     }

  93748.     if( rc!=SQLITE_OK || pTask->pThread==0 ) break;

  93749.   }

  93750. 

  93751.   if( rc==SQLITE_OK ){

  93752.     if( i==nWorker ){

  93753.       /* Use the foreground thread for this operation */

  93754.       rc = vdbeSorterListToPMA(&pSorter->aTask[nWorker], &pSorter->list);

  93755.     }else{

  93756.       /* Launch a background thread for this operation */

  93757.       u8 *aMem = pTask->list.aMemory;

  93758.       void *pCtx = (void*)pTask;

  93759. 

  93760.       assert( pTask->pThread==0 && pTask->bDone==0 );

  93761.       assert( pTask->list.pList==0 );

  93762.       assert( pTask->list.aMemory==0 || pSorter->list.aMemory!=0 );

  93763. 

  93764.       pSorter->iPrev = (u8)(pTask - pSorter->aTask);

  93765.       pTask->list = pSorter->list;

  93766.       pSorter->list.pList = 0;

  93767.       pSorter->list.szPMA = 0;

  93768.       if( aMem ){

  93769.         pSorter->list.aMemory = aMem;

  93770.         pSorter->nMemory = sqlite3MallocSize(aMem);

  93771.       }else if( pSorter->list.aMemory ){

  93772.         pSorter->list.aMemory = sqlite3Malloc(pSorter->nMemory);

  93773.         if( !pSorter->list.aMemory ) return SQLITE_NOMEM_BKPT;

  93774.       }

  93775. 

  93776.       rc = vdbeSorterCreateThread(pTask, vdbeSorterFlushThread, pCtx);

  93777.     }

  93778.   }

  93779. 

  93780.   return rc;

  93781. #endif /* SQLITE_MAX_WORKER_THREADS!=0 */

  93782. }

  93783. 

  93784. /*

  93785. ** Add a record to the sorter.

  93786. */

  93787. SQLITE_PRIVATE int sqlite3VdbeSorterWrite(

  93788.   const VdbeCursor *pCsr,         /* Sorter cursor */

  93789.   Mem *pVal                       /* Memory cell containing record */

  93790. ){

  93791.   VdbeSorter *pSorter;

  93792.   int rc = SQLITE_OK;             /* Return Code */

  93793.   SorterRecord *pNew;             /* New list element */

  93794.   int bFlush;                     /* True to flush contents of memory to PMA */

  93795.   int nReq;                       /* Bytes of memory required */

  93796.   int nPMA;                       /* Bytes of PMA space required */

  93797.   int t;                          /* serial type of first record field */

  93798. 

  93799.   assert( pCsr->eCurType==CURTYPE_SORTER );

  93800.   pSorter = pCsr->uc.pSorter;

  93801.   getVarint32((const u8*)&pVal->z[1], t);

  93802.   if( t>0 && t<10 && t!=7 ){

  93803.     pSorter->typeMask &= SORTER_TYPE_INTEGER;

  93804.   }else if( t>10 && (t & 0x01) ){

  93805.     pSorter->typeMask &= SORTER_TYPE_TEXT;

  93806.   }else{

  93807.     pSorter->typeMask = 0;

  93808.   }

  93809. 

  93810.   assert( pSorter );

  93811. 

  93812.   /* Figure out whether or not the current contents of memory should be

  93813.   ** flushed to a PMA before continuing. If so, do so.

  93814.   **

  93815.   ** If using the single large allocation mode (pSorter->aMemory!=0), then

  93816.   ** flush the contents of memory to a new PMA if (a) at least one value is

  93817.   ** already in memory and (b) the new value will not fit in memory.

  93818.   ** 

  93819.   ** Or, if using separate allocations for each record, flush the contents

  93820.   ** of memory to a PMA if either of the following are true:

  93821.   **

  93822.   **   * The total memory allocated for the in-memory list is greater 

  93823.   **     than (page-size * cache-size), or

  93824.   **

  93825.   **   * The total memory allocated for the in-memory list is greater 

  93826.   **     than (page-size * 10) and sqlite3HeapNearlyFull() returns true.

  93827.   */

  93828.   nReq = pVal->n + sizeof(SorterRecord);

  93829.   nPMA = pVal->n + sqlite3VarintLen(pVal->n);

  93830.   if( pSorter->mxPmaSize ){

  93831.     if( pSorter->list.aMemory ){

  93832.       bFlush = pSorter->iMemory && (pSorter->iMemory+nReq) > pSorter->mxPmaSize;

  93833.     }else{

  93834.       bFlush = (

  93835.           (pSorter->list.szPMA > pSorter->mxPmaSize)

  93836.        || (pSorter->list.szPMA > pSorter->mnPmaSize && sqlite3HeapNearlyFull())

  93837.       );

  93838.     }

  93839.     if( bFlush ){

  93840.       rc = vdbeSorterFlushPMA(pSorter);

  93841.       pSorter->list.szPMA = 0;

  93842.       pSorter->iMemory = 0;

  93843.       assert( rc!=SQLITE_OK || pSorter->list.pList==0 );

  93844.     }

  93845.   }

  93846. 

  93847.   pSorter->list.szPMA += nPMA;

  93848.   if( nPMA>pSorter->mxKeysize ){

  93849.     pSorter->mxKeysize = nPMA;

  93850.   }

  93851. 

  93852.   if( pSorter->list.aMemory ){

  93853.     int nMin = pSorter->iMemory + nReq;

  93854. 

  93855.     if( nMin>pSorter->nMemory ){

  93856.       u8 *aNew;

  93857.       sqlite3_int64 nNew = 2 * (sqlite3_int64)pSorter->nMemory;

  93858.       int iListOff = -1;

  93859.       if( pSorter->list.pList ){

  93860.         iListOff = (u8*)pSorter->list.pList - pSorter->list.aMemory;

  93861.       }

  93862.       while( nNew < nMin ) nNew = nNew*2;

  93863.       if( nNew > pSorter->mxPmaSize ) nNew = pSorter->mxPmaSize;

  93864.       if( nNew < nMin ) nNew = nMin;

  93865.       aNew = sqlite3Realloc(pSorter->list.aMemory, nNew);

  93866.       if( !aNew ) return SQLITE_NOMEM_BKPT;

  93867.       if( iListOff>=0 ){

  93868.         pSorter->list.pList = (SorterRecord*)&aNew[iListOff];

  93869.       }

  93870.       pSorter->list.aMemory = aNew;

  93871.       pSorter->nMemory = nNew;

  93872.     }

  93873. 

  93874.     pNew = (SorterRecord*)&pSorter->list.aMemory[pSorter->iMemory];

  93875.     pSorter->iMemory += ROUND8(nReq);

  93876.     if( pSorter->list.pList ){

  93877.       pNew->u.iNext = (int)((u8*)(pSorter->list.pList) - pSorter->list.aMemory);

  93878.     }

  93879.   }else{

  93880.     pNew = (SorterRecord *)sqlite3Malloc(nReq);

  93881.     if( pNew==0 ){

  93882.       return SQLITE_NOMEM_BKPT;

  93883.     }

  93884.     pNew->u.pNext = pSorter->list.pList;

  93885.   }

  93886. 

  93887.   memcpy(SRVAL(pNew), pVal->z, pVal->n);

  93888.   pNew->nVal = pVal->n;

  93889.   pSorter->list.pList = pNew;

  93890. 

  93891.   return rc;

  93892. }

  93893. 

  93894. /*

  93895. ** Read keys from pIncr->pMerger and populate pIncr->aFile[1]. The format

  93896. ** of the data stored in aFile[1] is the same as that used by regular PMAs,

  93897. ** except that the number-of-bytes varint is omitted from the start.

  93898. */

  93899. static int vdbeIncrPopulate(IncrMerger *pIncr){

  93900.   int rc = SQLITE_OK;

  93901.   int rc2;

  93902.   i64 iStart = pIncr->iStartOff;

  93903.   SorterFile *pOut = &pIncr->aFile[1];

  93904.   SortSubtask *pTask = pIncr->pTask;

  93905.   MergeEngine *pMerger = pIncr->pMerger;

  93906.   PmaWriter writer;

  93907.   assert( pIncr->bEof==0 );

  93908. 

  93909.   vdbeSorterPopulateDebug(pTask, "enter");

  93910. 

  93911.   vdbePmaWriterInit(pOut->pFd, &writer, pTask->pSorter->pgsz, iStart);

  93912.   while( rc==SQLITE_OK ){

  93913.     int dummy;

  93914.     PmaReader *pReader = &pMerger->aReadr[ pMerger->aTree[1] ];

  93915.     int nKey = pReader->nKey;

  93916.     i64 iEof = writer.iWriteOff + writer.iBufEnd;

  93917. 

  93918.     /* Check if the output file is full or if the input has been exhausted.

  93919.     ** In either case exit the loop. */

  93920.     if( pReader->pFd==0 ) break;

  93921.     if( (iEof + nKey + sqlite3VarintLen(nKey))>(iStart + pIncr->mxSz) ) break;

  93922. 

  93923.     /* Write the next key to the output. */

  93924.     vdbePmaWriteVarint(&writer, nKey);

  93925.     vdbePmaWriteBlob(&writer, pReader->aKey, nKey);

  93926.     assert( pIncr->pMerger->pTask==pTask );

  93927.     rc = vdbeMergeEngineStep(pIncr->pMerger, &dummy);

  93928.   }

  93929. 

  93930.   rc2 = vdbePmaWriterFinish(&writer, &pOut->iEof);

  93931.   if( rc==SQLITE_OK ) rc = rc2;

  93932.   vdbeSorterPopulateDebug(pTask, "exit");

  93933.   return rc;

  93934. }

  93935. 

  93936. #if SQLITE_MAX_WORKER_THREADS>0

  93937. /*

  93938. ** The main routine for background threads that populate aFile[1] of

  93939. ** multi-threaded IncrMerger objects.

  93940. */

  93941. static void *vdbeIncrPopulateThread(void *pCtx){

  93942.   IncrMerger *pIncr = (IncrMerger*)pCtx;

  93943.   void *pRet = SQLITE_INT_TO_PTR( vdbeIncrPopulate(pIncr) );

  93944.   pIncr->pTask->bDone = 1;

  93945.   return pRet;

  93946. }

  93947. 

  93948. /*

  93949. ** Launch a background thread to populate aFile[1] of pIncr.

  93950. */

  93951. static int vdbeIncrBgPopulate(IncrMerger *pIncr){

  93952.   void *p = (void*)pIncr;

  93953.   assert( pIncr->bUseThread );

  93954.   return vdbeSorterCreateThread(pIncr->pTask, vdbeIncrPopulateThread, p);

  93955. }

  93956. #endif

  93957. 

  93958. /*

  93959. ** This function is called when the PmaReader corresponding to pIncr has

  93960. ** finished reading the contents of aFile[0]. Its purpose is to "refill"

  93961. ** aFile[0] such that the PmaReader should start rereading it from the

  93962. ** beginning.

  93963. **

  93964. ** For single-threaded objects, this is accomplished by literally reading 

  93965. ** keys from pIncr->pMerger and repopulating aFile[0]. 

  93966. **

  93967. ** For multi-threaded objects, all that is required is to wait until the 

  93968. ** background thread is finished (if it is not already) and then swap 

  93969. ** aFile[0] and aFile[1] in place. If the contents of pMerger have not

  93970. ** been exhausted, this function also launches a new background thread

  93971. ** to populate the new aFile[1].

  93972. **

  93973. ** SQLITE_OK is returned on success, or an SQLite error code otherwise.

  93974. */

  93975. static int vdbeIncrSwap(IncrMerger *pIncr){

  93976.   int rc = SQLITE_OK;

  93977. 

  93978. #if SQLITE_MAX_WORKER_THREADS>0

  93979.   if( pIncr->bUseThread ){

  93980.     rc = vdbeSorterJoinThread(pIncr->pTask);

  93981. 

  93982.     if( rc==SQLITE_OK ){

  93983.       SorterFile f0 = pIncr->aFile[0];

  93984.       pIncr->aFile[0] = pIncr->aFile[1];

  93985.       pIncr->aFile[1] = f0;

  93986.     }

  93987. 

  93988.     if( rc==SQLITE_OK ){

  93989.       if( pIncr->aFile[0].iEof==pIncr->iStartOff ){

  93990.         pIncr->bEof = 1;

  93991.       }else{

  93992.         rc = vdbeIncrBgPopulate(pIncr);

  93993.       }

  93994.     }

  93995.   }else

  93996. #endif

  93997.   {

  93998.     rc = vdbeIncrPopulate(pIncr);

  93999.     pIncr->aFile[0] = pIncr->aFile[1];

  94000.     if( pIncr->aFile[0].iEof==pIncr->iStartOff ){

  94001.       pIncr->bEof = 1;

  94002.     }

  94003.   }

  94004. 

  94005.   return rc;

  94006. }

  94007. 

  94008. /*

  94009. ** Allocate and return a new IncrMerger object to read data from pMerger.

  94010. **

  94011. ** If an OOM condition is encountered, return NULL. In this case free the

  94012. ** pMerger argument before returning.

  94013. */

  94014. static int vdbeIncrMergerNew(

  94015.   SortSubtask *pTask,     /* The thread that will be using the new IncrMerger */

  94016.   MergeEngine *pMerger,   /* The MergeEngine that the IncrMerger will control */

  94017.   IncrMerger **ppOut      /* Write the new IncrMerger here */

  94018. ){

  94019.   int rc = SQLITE_OK;

  94020.   IncrMerger *pIncr = *ppOut = (IncrMerger*)

  94021.        (sqlite3FaultSim(100) ? 0 : sqlite3MallocZero(sizeof(*pIncr)));

  94022.   if( pIncr ){

  94023.     pIncr->pMerger = pMerger;

  94024.     pIncr->pTask = pTask;

  94025.     pIncr->mxSz = MAX(pTask->pSorter->mxKeysize+9,pTask->pSorter->mxPmaSize/2);

  94026.     pTask->file2.iEof += pIncr->mxSz;

  94027.   }else{

  94028.     vdbeMergeEngineFree(pMerger);

  94029.     rc = SQLITE_NOMEM_BKPT;

  94030.   }

  94031.   return rc;

  94032. }

  94033. 

  94034. #if SQLITE_MAX_WORKER_THREADS>0

  94035. /*

  94036. ** Set the "use-threads" flag on object pIncr.

  94037. */

  94038. static void vdbeIncrMergerSetThreads(IncrMerger *pIncr){

  94039.   pIncr->bUseThread = 1;

  94040.   pIncr->pTask->file2.iEof -= pIncr->mxSz;

  94041. }

  94042. #endif /* SQLITE_MAX_WORKER_THREADS>0 */

  94043. 

  94044. 

  94045. 

  94046. /*

  94047. ** Recompute pMerger->aTree[iOut] by comparing the next keys on the

  94048. ** two PmaReaders that feed that entry.  Neither of the PmaReaders

  94049. ** are advanced.  This routine merely does the comparison.

  94050. */

  94051. static void vdbeMergeEngineCompare(

  94052.   MergeEngine *pMerger,  /* Merge engine containing PmaReaders to compare */

  94053.   int iOut               /* Store the result in pMerger->aTree[iOut] */

  94054. ){

  94055.   int i1;

  94056.   int i2;

  94057.   int iRes;

  94058.   PmaReader *p1;

  94059.   PmaReader *p2;

  94060. 

  94061.   assert( iOut<pMerger->nTree && iOut>0 );

  94062. 

  94063.   if( iOut>=(pMerger->nTree/2) ){

  94064.     i1 = (iOut - pMerger->nTree/2) * 2;

  94065.     i2 = i1 + 1;

  94066.   }else{

  94067.     i1 = pMerger->aTree[iOut*2];

  94068.     i2 = pMerger->aTree[iOut*2+1];

  94069.   }

  94070. 

  94071.   p1 = &pMerger->aReadr[i1];

  94072.   p2 = &pMerger->aReadr[i2];

  94073. 

  94074.   if( p1->pFd==0 ){

  94075.     iRes = i2;

  94076.   }else if( p2->pFd==0 ){

  94077.     iRes = i1;

  94078.   }else{

  94079.     SortSubtask *pTask = pMerger->pTask;

  94080.     int bCached = 0;

  94081.     int res;

  94082.     assert( pTask->pUnpacked!=0 );  /* from vdbeSortSubtaskMain() */

  94083.     res = pTask->xCompare(

  94084.         pTask, &bCached, p1->aKey, p1->nKey, p2->aKey, p2->nKey

  94085.     );

  94086.     if( res<=0 ){

  94087.       iRes = i1;

  94088.     }else{

  94089.       iRes = i2;

  94090.     }

  94091.   }

  94092. 

  94093.   pMerger->aTree[iOut] = iRes;

  94094. }

  94095. 

  94096. /*

  94097. ** Allowed values for the eMode parameter to vdbeMergeEngineInit()

  94098. ** and vdbePmaReaderIncrMergeInit().

  94099. **

  94100. ** Only INCRINIT_NORMAL is valid in single-threaded builds (when

  94101. ** SQLITE_MAX_WORKER_THREADS==0).  The other values are only used

  94102. ** when there exists one or more separate worker threads.

  94103. */

  94104. #define INCRINIT_NORMAL 0

  94105. #define INCRINIT_TASK   1

  94106. #define INCRINIT_ROOT   2

  94107. 

  94108. /* 

  94109. ** Forward reference required as the vdbeIncrMergeInit() and

  94110. ** vdbePmaReaderIncrInit() routines are called mutually recursively when

  94111. ** building a merge tree.

  94112. */

  94113. static int vdbePmaReaderIncrInit(PmaReader *pReadr, int eMode);

  94114. 

  94115. /*

  94116. ** Initialize the MergeEngine object passed as the second argument. Once this

  94117. ** function returns, the first key of merged data may be read from the 

  94118. ** MergeEngine object in the usual fashion.

  94119. **

  94120. ** If argument eMode is INCRINIT_ROOT, then it is assumed that any IncrMerge

  94121. ** objects attached to the PmaReader objects that the merger reads from have

  94122. ** already been populated, but that they have not yet populated aFile[0] and

  94123. ** set the PmaReader objects up to read from it. In this case all that is

  94124. ** required is to call vdbePmaReaderNext() on each PmaReader to point it at

  94125. ** its first key.

  94126. **

  94127. ** Otherwise, if eMode is any value other than INCRINIT_ROOT, then use 

  94128. ** vdbePmaReaderIncrMergeInit() to initialize each PmaReader that feeds data 

  94129. ** to pMerger.

  94130. **

  94131. ** SQLITE_OK is returned if successful, or an SQLite error code otherwise.

  94132. */

  94133. static int vdbeMergeEngineInit(

  94134.   SortSubtask *pTask,             /* Thread that will run pMerger */

  94135.   MergeEngine *pMerger,           /* MergeEngine to initialize */

  94136.   int eMode                       /* One of the INCRINIT_XXX constants */

  94137. ){

  94138.   int rc = SQLITE_OK;             /* Return code */

  94139.   int i;                          /* For looping over PmaReader objects */

  94140.   int nTree;                      /* Number of subtrees to merge */

  94141. 

  94142.   /* Failure to allocate the merge would have been detected prior to

  94143.   ** invoking this routine */

  94144.   assert( pMerger!=0 );

  94145. 

  94146.   /* eMode is always INCRINIT_NORMAL in single-threaded mode */

  94147.   assert( SQLITE_MAX_WORKER_THREADS>0 || eMode==INCRINIT_NORMAL );

  94148. 

  94149.   /* Verify that the MergeEngine is assigned to a single thread */

  94150.   assert( pMerger->pTask==0 );

  94151.   pMerger->pTask = pTask;

  94152. 

  94153.   nTree = pMerger->nTree;

  94154.   for(i=0; i<nTree; i++){

  94155.     if( SQLITE_MAX_WORKER_THREADS>0 && eMode==INCRINIT_ROOT ){

  94156.       /* PmaReaders should be normally initialized in order, as if they are

  94157.       ** reading from the same temp file this makes for more linear file IO.

  94158.       ** However, in the INCRINIT_ROOT case, if PmaReader aReadr[nTask-1] is

  94159.       ** in use it will block the vdbePmaReaderNext() call while it uses

  94160.       ** the main thread to fill its buffer. So calling PmaReaderNext()

  94161.       ** on this PmaReader before any of the multi-threaded PmaReaders takes

  94162.       ** better advantage of multi-processor hardware. */

  94163.       rc = vdbePmaReaderNext(&pMerger->aReadr[nTree-i-1]);

  94164.     }else{

  94165.       rc = vdbePmaReaderIncrInit(&pMerger->aReadr[i], INCRINIT_NORMAL);

  94166.     }

  94167.     if( rc!=SQLITE_OK ) return rc;

  94168.   }

  94169. 

  94170.   for(i=pMerger->nTree-1; i>0; i--){

  94171.     vdbeMergeEngineCompare(pMerger, i);

  94172.   }

  94173.   return pTask->pUnpacked->errCode;

  94174. }

  94175. 

  94176. /*

  94177. ** The PmaReader passed as the first argument is guaranteed to be an

  94178. ** incremental-reader (pReadr->pIncr!=0). This function serves to open

  94179. ** and/or initialize the temp file related fields of the IncrMerge

  94180. ** object at (pReadr->pIncr).

  94181. **

  94182. ** If argument eMode is set to INCRINIT_NORMAL, then all PmaReaders

  94183. ** in the sub-tree headed by pReadr are also initialized. Data is then 

  94184. ** loaded into the buffers belonging to pReadr and it is set to point to 

  94185. ** the first key in its range.

  94186. **

  94187. ** If argument eMode is set to INCRINIT_TASK, then pReadr is guaranteed

  94188. ** to be a multi-threaded PmaReader and this function is being called in a

  94189. ** background thread. In this case all PmaReaders in the sub-tree are 

  94190. ** initialized as for INCRINIT_NORMAL and the aFile[1] buffer belonging to

  94191. ** pReadr is populated. However, pReadr itself is not set up to point

  94192. ** to its first key. A call to vdbePmaReaderNext() is still required to do

  94193. ** that. 

  94194. **

  94195. ** The reason this function does not call vdbePmaReaderNext() immediately 

  94196. ** in the INCRINIT_TASK case is that vdbePmaReaderNext() assumes that it has

  94197. ** to block on thread (pTask->thread) before accessing aFile[1]. But, since

  94198. ** this entire function is being run by thread (pTask->thread), that will

  94199. ** lead to the current background thread attempting to join itself.

  94200. **

  94201. ** Finally, if argument eMode is set to INCRINIT_ROOT, it may be assumed

  94202. ** that pReadr->pIncr is a multi-threaded IncrMerge objects, and that all

  94203. ** child-trees have already been initialized using IncrInit(INCRINIT_TASK).

  94204. ** In this case vdbePmaReaderNext() is called on all child PmaReaders and

  94205. ** the current PmaReader set to point to the first key in its range.

  94206. **

  94207. ** SQLITE_OK is returned if successful, or an SQLite error code otherwise.

  94208. */

  94209. static int vdbePmaReaderIncrMergeInit(PmaReader *pReadr, int eMode){

  94210.   int rc = SQLITE_OK;

  94211.   IncrMerger *pIncr = pReadr->pIncr;

  94212.   SortSubtask *pTask = pIncr->pTask;

  94213.   sqlite3 *db = pTask->pSorter->db;

  94214. 

  94215.   /* eMode is always INCRINIT_NORMAL in single-threaded mode */

  94216.   assert( SQLITE_MAX_WORKER_THREADS>0 || eMode==INCRINIT_NORMAL );

  94217. 

  94218.   rc = vdbeMergeEngineInit(pTask, pIncr->pMerger, eMode);

  94219. 

  94220.   /* Set up the required files for pIncr. A multi-theaded IncrMerge object

  94221.   ** requires two temp files to itself, whereas a single-threaded object

  94222.   ** only requires a region of pTask->file2. */

  94223.   if( rc==SQLITE_OK ){

  94224.     int mxSz = pIncr->mxSz;

  94225. #if SQLITE_MAX_WORKER_THREADS>0

  94226.     if( pIncr->bUseThread ){

  94227.       rc = vdbeSorterOpenTempFile(db, mxSz, &pIncr->aFile[0].pFd);

  94228.       if( rc==SQLITE_OK ){

  94229.         rc = vdbeSorterOpenTempFile(db, mxSz, &pIncr->aFile[1].pFd);

  94230.       }

  94231.     }else

  94232. #endif

  94233.     /*if( !pIncr->bUseThread )*/{

  94234.       if( pTask->file2.pFd==0 ){

  94235.         assert( pTask->file2.iEof>0 );

  94236.         rc = vdbeSorterOpenTempFile(db, pTask->file2.iEof, &pTask->file2.pFd);

  94237.         pTask->file2.iEof = 0;

  94238.       }

  94239.       if( rc==SQLITE_OK ){

  94240.         pIncr->aFile[1].pFd = pTask->file2.pFd;

  94241.         pIncr->iStartOff = pTask->file2.iEof;

  94242.         pTask->file2.iEof += mxSz;

  94243.       }

  94244.     }

  94245.   }

  94246. 

  94247. #if SQLITE_MAX_WORKER_THREADS>0

  94248.   if( rc==SQLITE_OK && pIncr->bUseThread ){

  94249.     /* Use the current thread to populate aFile[1], even though this

  94250.     ** PmaReader is multi-threaded. If this is an INCRINIT_TASK object,

  94251.     ** then this function is already running in background thread 

  94252.     ** pIncr->pTask->thread. 

  94253.     **

  94254.     ** If this is the INCRINIT_ROOT object, then it is running in the 

  94255.     ** main VDBE thread. But that is Ok, as that thread cannot return

  94256.     ** control to the VDBE or proceed with anything useful until the 

  94257.     ** first results are ready from this merger object anyway.

  94258.     */

  94259.     assert( eMode==INCRINIT_ROOT || eMode==INCRINIT_TASK );

  94260.     rc = vdbeIncrPopulate(pIncr);

  94261.   }

  94262. #endif

  94263. 

  94264.   if( rc==SQLITE_OK && (SQLITE_MAX_WORKER_THREADS==0 || eMode!=INCRINIT_TASK) ){

  94265.     rc = vdbePmaReaderNext(pReadr);

  94266.   }

  94267. 

  94268.   return rc;

  94269. }

  94270. 

  94271. #if SQLITE_MAX_WORKER_THREADS>0

  94272. /*

  94273. ** The main routine for vdbePmaReaderIncrMergeInit() operations run in 

  94274. ** background threads.

  94275. */

  94276. static void *vdbePmaReaderBgIncrInit(void *pCtx){

  94277.   PmaReader *pReader = (PmaReader*)pCtx;

  94278.   void *pRet = SQLITE_INT_TO_PTR(

  94279.                   vdbePmaReaderIncrMergeInit(pReader,INCRINIT_TASK)

  94280.                );

  94281.   pReader->pIncr->pTask->bDone = 1;

  94282.   return pRet;

  94283. }

  94284. #endif

  94285. 

  94286. /*

  94287. ** If the PmaReader passed as the first argument is not an incremental-reader

  94288. ** (if pReadr->pIncr==0), then this function is a no-op. Otherwise, it invokes

  94289. ** the vdbePmaReaderIncrMergeInit() function with the parameters passed to

  94290. ** this routine to initialize the incremental merge.

  94291. ** 

  94292. ** If the IncrMerger object is multi-threaded (IncrMerger.bUseThread==1), 

  94293. ** then a background thread is launched to call vdbePmaReaderIncrMergeInit().

  94294. ** Or, if the IncrMerger is single threaded, the same function is called

  94295. ** using the current thread.

  94296. */

  94297. static int vdbePmaReaderIncrInit(PmaReader *pReadr, int eMode){

  94298.   IncrMerger *pIncr = pReadr->pIncr;   /* Incremental merger */

  94299.   int rc = SQLITE_OK;                  /* Return code */

  94300.   if( pIncr ){

  94301. #if SQLITE_MAX_WORKER_THREADS>0

  94302.     assert( pIncr->bUseThread==0 || eMode==INCRINIT_TASK );

  94303.     if( pIncr->bUseThread ){

  94304.       void *pCtx = (void*)pReadr;

  94305.       rc = vdbeSorterCreateThread(pIncr->pTask, vdbePmaReaderBgIncrInit, pCtx);

  94306.     }else

  94307. #endif

  94308.     {

  94309.       rc = vdbePmaReaderIncrMergeInit(pReadr, eMode);

  94310.     }

  94311.   }

  94312.   return rc;

  94313. }

  94314. 

  94315. /*

  94316. ** Allocate a new MergeEngine object to merge the contents of nPMA level-0

  94317. ** PMAs from pTask->file. If no error occurs, set *ppOut to point to

  94318. ** the new object and return SQLITE_OK. Or, if an error does occur, set *ppOut

  94319. ** to NULL and return an SQLite error code.

  94320. **

  94321. ** When this function is called, *piOffset is set to the offset of the

  94322. ** first PMA to read from pTask->file. Assuming no error occurs, it is 

  94323. ** set to the offset immediately following the last byte of the last

  94324. ** PMA before returning. If an error does occur, then the final value of

  94325. ** *piOffset is undefined.

  94326. */

  94327. static int vdbeMergeEngineLevel0(

  94328.   SortSubtask *pTask,             /* Sorter task to read from */

  94329.   int nPMA,                       /* Number of PMAs to read */

  94330.   i64 *piOffset,                  /* IN/OUT: Readr offset in pTask->file */

  94331.   MergeEngine **ppOut             /* OUT: New merge-engine */

  94332. ){

  94333.   MergeEngine *pNew;              /* Merge engine to return */

  94334.   i64 iOff = *piOffset;

  94335.   int i;

  94336.   int rc = SQLITE_OK;

  94337. 

  94338.   *ppOut = pNew = vdbeMergeEngineNew(nPMA);

  94339.   if( pNew==0 ) rc = SQLITE_NOMEM_BKPT;

  94340. 

  94341.   for(i=0; i<nPMA && rc==SQLITE_OK; i++){

  94342.     i64 nDummy = 0;

  94343.     PmaReader *pReadr = &pNew->aReadr[i];

  94344.     rc = vdbePmaReaderInit(pTask, &pTask->file, iOff, pReadr, &nDummy);

  94345.     iOff = pReadr->iEof;

  94346.   }

  94347. 

  94348.   if( rc!=SQLITE_OK ){

  94349.     vdbeMergeEngineFree(pNew);

  94350.     *ppOut = 0;

  94351.   }

  94352.   *piOffset = iOff;

  94353.   return rc;

  94354. }

  94355. 

  94356. /*

  94357. ** Return the depth of a tree comprising nPMA PMAs, assuming a fanout of

  94358. ** SORTER_MAX_MERGE_COUNT. The returned value does not include leaf nodes.

  94359. **

  94360. ** i.e.

  94361. **

  94362. **   nPMA<=16    -> TreeDepth() == 0

  94363. **   nPMA<=256   -> TreeDepth() == 1

  94364. **   nPMA<=65536 -> TreeDepth() == 2

  94365. */

  94366. static int vdbeSorterTreeDepth(int nPMA){

  94367.   int nDepth = 0;

  94368.   i64 nDiv = SORTER_MAX_MERGE_COUNT;

  94369.   while( nDiv < (i64)nPMA ){

  94370.     nDiv = nDiv * SORTER_MAX_MERGE_COUNT;

  94371.     nDepth++;

  94372.   }

  94373.   return nDepth;

  94374. }

  94375. 

  94376. /*

  94377. ** pRoot is the root of an incremental merge-tree with depth nDepth (according

  94378. ** to vdbeSorterTreeDepth()). pLeaf is the iSeq'th leaf to be added to the

  94379. ** tree, counting from zero. This function adds pLeaf to the tree.

  94380. **

  94381. ** If successful, SQLITE_OK is returned. If an error occurs, an SQLite error

  94382. ** code is returned and pLeaf is freed.

  94383. */

  94384. static int vdbeSorterAddToTree(

  94385.   SortSubtask *pTask,             /* Task context */

  94386.   int nDepth,                     /* Depth of tree according to TreeDepth() */

  94387.   int iSeq,                       /* Sequence number of leaf within tree */

  94388.   MergeEngine *pRoot,             /* Root of tree */

  94389.   MergeEngine *pLeaf              /* Leaf to add to tree */

  94390. ){

  94391.   int rc = SQLITE_OK;

  94392.   int nDiv = 1;

  94393.   int i;

  94394.   MergeEngine *p = pRoot;

  94395.   IncrMerger *pIncr;

  94396. 

  94397.   rc = vdbeIncrMergerNew(pTask, pLeaf, &pIncr);

  94398. 

  94399.   for(i=1; i<nDepth; i++){

  94400.     nDiv = nDiv * SORTER_MAX_MERGE_COUNT;

  94401.   }

  94402. 

  94403.   for(i=1; i<nDepth && rc==SQLITE_OK; i++){

  94404.     int iIter = (iSeq / nDiv) % SORTER_MAX_MERGE_COUNT;

  94405.     PmaReader *pReadr = &p->aReadr[iIter];

  94406. 

  94407.     if( pReadr->pIncr==0 ){

  94408.       MergeEngine *pNew = vdbeMergeEngineNew(SORTER_MAX_MERGE_COUNT);

  94409.       if( pNew==0 ){

  94410.         rc = SQLITE_NOMEM_BKPT;

  94411.       }else{

  94412.         rc = vdbeIncrMergerNew(pTask, pNew, &pReadr->pIncr);

  94413.       }

  94414.     }

  94415.     if( rc==SQLITE_OK ){

  94416.       p = pReadr->pIncr->pMerger;

  94417.       nDiv = nDiv / SORTER_MAX_MERGE_COUNT;

  94418.     }

  94419.   }

  94420. 

  94421.   if( rc==SQLITE_OK ){

  94422.     p->aReadr[iSeq % SORTER_MAX_MERGE_COUNT].pIncr = pIncr;

  94423.   }else{

  94424.     vdbeIncrFree(pIncr);

  94425.   }

  94426.   return rc;

  94427. }

  94428. 

  94429. /*

  94430. ** This function is called as part of a SorterRewind() operation on a sorter

  94431. ** that has already written two or more level-0 PMAs to one or more temp

  94432. ** files. It builds a tree of MergeEngine/IncrMerger/PmaReader objects that 

  94433. ** can be used to incrementally merge all PMAs on disk.

  94434. **

  94435. ** If successful, SQLITE_OK is returned and *ppOut set to point to the

  94436. ** MergeEngine object at the root of the tree before returning. Or, if an

  94437. ** error occurs, an SQLite error code is returned and the final value 

  94438. ** of *ppOut is undefined.

  94439. */

  94440. static int vdbeSorterMergeTreeBuild(

  94441.   VdbeSorter *pSorter,       /* The VDBE cursor that implements the sort */

  94442.   MergeEngine **ppOut        /* Write the MergeEngine here */

  94443. ){

  94444.   MergeEngine *pMain = 0;

  94445.   int rc = SQLITE_OK;

  94446.   int iTask;

  94447. 

  94448. #if SQLITE_MAX_WORKER_THREADS>0

  94449.   /* If the sorter uses more than one task, then create the top-level 

  94450.   ** MergeEngine here. This MergeEngine will read data from exactly 

  94451.   ** one PmaReader per sub-task.  */

  94452.   assert( pSorter->bUseThreads || pSorter->nTask==1 );

  94453.   if( pSorter->nTask>1 ){

  94454.     pMain = vdbeMergeEngineNew(pSorter->nTask);

  94455.     if( pMain==0 ) rc = SQLITE_NOMEM_BKPT;

  94456.   }

  94457. #endif

  94458. 

  94459.   for(iTask=0; rc==SQLITE_OK && iTask<pSorter->nTask; iTask++){

  94460.     SortSubtask *pTask = &pSorter->aTask[iTask];

  94461.     assert( pTask->nPMA>0 || SQLITE_MAX_WORKER_THREADS>0 );

  94462.     if( SQLITE_MAX_WORKER_THREADS==0 || pTask->nPMA ){

  94463.       MergeEngine *pRoot = 0;     /* Root node of tree for this task */

  94464.       int nDepth = vdbeSorterTreeDepth(pTask->nPMA);

  94465.       i64 iReadOff = 0;

  94466. 

  94467.       if( pTask->nPMA<=SORTER_MAX_MERGE_COUNT ){

  94468.         rc = vdbeMergeEngineLevel0(pTask, pTask->nPMA, &iReadOff, &pRoot);

  94469.       }else{

  94470.         int i;

  94471.         int iSeq = 0;

  94472.         pRoot = vdbeMergeEngineNew(SORTER_MAX_MERGE_COUNT);

  94473.         if( pRoot==0 ) rc = SQLITE_NOMEM_BKPT;

  94474.         for(i=0; i<pTask->nPMA && rc==SQLITE_OK; i += SORTER_MAX_MERGE_COUNT){

  94475.           MergeEngine *pMerger = 0; /* New level-0 PMA merger */

  94476.           int nReader;              /* Number of level-0 PMAs to merge */

  94477. 

  94478.           nReader = MIN(pTask->nPMA - i, SORTER_MAX_MERGE_COUNT);

  94479.           rc = vdbeMergeEngineLevel0(pTask, nReader, &iReadOff, &pMerger);

  94480.           if( rc==SQLITE_OK ){

  94481.             rc = vdbeSorterAddToTree(pTask, nDepth, iSeq++, pRoot, pMerger);

  94482.           }

  94483.         }

  94484.       }

  94485. 

  94486.       if( rc==SQLITE_OK ){

  94487. #if SQLITE_MAX_WORKER_THREADS>0

  94488.         if( pMain!=0 ){

  94489.           rc = vdbeIncrMergerNew(pTask, pRoot, &pMain->aReadr[iTask].pIncr);

  94490.         }else

  94491. #endif

  94492.         {

  94493.           assert( pMain==0 );

  94494.           pMain = pRoot;

  94495.         }

  94496.       }else{

  94497.         vdbeMergeEngineFree(pRoot);

  94498.       }

  94499.     }

  94500.   }

  94501. 

  94502.   if( rc!=SQLITE_OK ){

  94503.     vdbeMergeEngineFree(pMain);

  94504.     pMain = 0;

  94505.   }

  94506.   *ppOut = pMain;

  94507.   return rc;

  94508. }

  94509. 

  94510. /*

  94511. ** This function is called as part of an sqlite3VdbeSorterRewind() operation

  94512. ** on a sorter that has written two or more PMAs to temporary files. It sets

  94513. ** up either VdbeSorter.pMerger (for single threaded sorters) or pReader

  94514. ** (for multi-threaded sorters) so that it can be used to iterate through

  94515. ** all records stored in the sorter.

  94516. **

  94517. ** SQLITE_OK is returned if successful, or an SQLite error code otherwise.

  94518. */

  94519. static int vdbeSorterSetupMerge(VdbeSorter *pSorter){

  94520.   int rc;                         /* Return code */

  94521.   SortSubtask *pTask0 = &pSorter->aTask[0];

  94522.   MergeEngine *pMain = 0;

  94523. #if SQLITE_MAX_WORKER_THREADS

  94524.   sqlite3 *db = pTask0->pSorter->db;

  94525.   int i;

  94526.   SorterCompare xCompare = vdbeSorterGetCompare(pSorter);

  94527.   for(i=0; i<pSorter->nTask; i++){

  94528.     pSorter->aTask[i].xCompare = xCompare;

  94529.   }

  94530. #endif

  94531. 

  94532.   rc = vdbeSorterMergeTreeBuild(pSorter, &pMain);

  94533.   if( rc==SQLITE_OK ){

  94534. #if SQLITE_MAX_WORKER_THREADS

  94535.     assert( pSorter->bUseThreads==0 || pSorter->nTask>1 );

  94536.     if( pSorter->bUseThreads ){

  94537.       int iTask;

  94538.       PmaReader *pReadr = 0;

  94539.       SortSubtask *pLast = &pSorter->aTask[pSorter->nTask-1];

  94540.       rc = vdbeSortAllocUnpacked(pLast);

  94541.       if( rc==SQLITE_OK ){

  94542.         pReadr = (PmaReader*)sqlite3DbMallocZero(db, sizeof(PmaReader));

  94543.         pSorter->pReader = pReadr;

  94544.         if( pReadr==0 ) rc = SQLITE_NOMEM_BKPT;

  94545.       }

  94546.       if( rc==SQLITE_OK ){

  94547.         rc = vdbeIncrMergerNew(pLast, pMain, &pReadr->pIncr);

  94548.         if( rc==SQLITE_OK ){

  94549.           vdbeIncrMergerSetThreads(pReadr->pIncr);

  94550.           for(iTask=0; iTask<(pSorter->nTask-1); iTask++){

  94551.             IncrMerger *pIncr;

  94552.             if( (pIncr = pMain->aReadr[iTask].pIncr) ){

  94553.               vdbeIncrMergerSetThreads(pIncr);

  94554.               assert( pIncr->pTask!=pLast );

  94555.             }

  94556.           }

  94557.           for(iTask=0; rc==SQLITE_OK && iTask<pSorter->nTask; iTask++){

  94558.             /* Check that:

  94559.             **   

  94560.             **   a) The incremental merge object is configured to use the

  94561.             **      right task, and

  94562.             **   b) If it is using task (nTask-1), it is configured to run

  94563.             **      in single-threaded mode. This is important, as the

  94564.             **      root merge (INCRINIT_ROOT) will be using the same task

  94565.             **      object.

  94566.             */

  94567.             PmaReader *p = &pMain->aReadr[iTask];

  94568.             assert( p->pIncr==0 || (

  94569.                 (p->pIncr->pTask==&pSorter->aTask[iTask])             /* a */

  94570.              && (iTask!=pSorter->nTask-1 || p->pIncr->bUseThread==0)  /* b */

  94571.             ));

  94572.             rc = vdbePmaReaderIncrInit(p, INCRINIT_TASK);

  94573.           }

  94574.         }

  94575.         pMain = 0;

  94576.       }

  94577.       if( rc==SQLITE_OK ){

  94578.         rc = vdbePmaReaderIncrMergeInit(pReadr, INCRINIT_ROOT);

  94579.       }

  94580.     }else

  94581. #endif

  94582.     {

  94583.       rc = vdbeMergeEngineInit(pTask0, pMain, INCRINIT_NORMAL);

  94584.       pSorter->pMerger = pMain;

  94585.       pMain = 0;

  94586.     }

  94587.   }

  94588. 

  94589.   if( rc!=SQLITE_OK ){

  94590.     vdbeMergeEngineFree(pMain);

  94591.   }

  94592.   return rc;

  94593. }

  94594. 

  94595. 

  94596. /*

  94597. ** Once the sorter has been populated by calls to sqlite3VdbeSorterWrite,

  94598. ** this function is called to prepare for iterating through the records

  94599. ** in sorted order.

  94600. */

  94601. SQLITE_PRIVATE int sqlite3VdbeSorterRewind(const VdbeCursor *pCsr, int *pbEof){

  94602.   VdbeSorter *pSorter;

  94603.   int rc = SQLITE_OK;             /* Return code */

  94604. 

  94605.   assert( pCsr->eCurType==CURTYPE_SORTER );

  94606.   pSorter = pCsr->uc.pSorter;

  94607.   assert( pSorter );

  94608. 

  94609.   /* If no data has been written to disk, then do not do so now. Instead,

  94610.   ** sort the VdbeSorter.pRecord list. The vdbe layer will read data directly

  94611.   ** from the in-memory list.  */

  94612.   if( pSorter->bUsePMA==0 ){

  94613.     if( pSorter->list.pList ){

  94614.       *pbEof = 0;

  94615.       rc = vdbeSorterSort(&pSorter->aTask[0], &pSorter->list);

  94616.     }else{

  94617.       *pbEof = 1;

  94618.     }

  94619.     return rc;

  94620.   }

  94621. 

  94622.   /* Write the current in-memory list to a PMA. When the VdbeSorterWrite() 

  94623.   ** function flushes the contents of memory to disk, it immediately always

  94624.   ** creates a new list consisting of a single key immediately afterwards.

  94625.   ** So the list is never empty at this point.  */

  94626.   assert( pSorter->list.pList );

  94627.   rc = vdbeSorterFlushPMA(pSorter);

  94628. 

  94629.   /* Join all threads */

  94630.   rc = vdbeSorterJoinAll(pSorter, rc);

  94631. 

  94632.   vdbeSorterRewindDebug("rewind");

  94633. 

  94634.   /* Assuming no errors have occurred, set up a merger structure to 

  94635.   ** incrementally read and merge all remaining PMAs.  */

  94636.   assert( pSorter->pReader==0 );

  94637.   if( rc==SQLITE_OK ){

  94638.     rc = vdbeSorterSetupMerge(pSorter);

  94639.     *pbEof = 0;

  94640.   }

  94641. 

  94642.   vdbeSorterRewindDebug("rewinddone");

  94643.   return rc;

  94644. }

  94645. 

  94646. /*

  94647. ** Advance to the next element in the sorter.  Return value:

  94648. **

  94649. **    SQLITE_OK     success

  94650. **    SQLITE_DONE   end of data

  94651. **    otherwise     some kind of error.

  94652. */

  94653. SQLITE_PRIVATE int sqlite3VdbeSorterNext(sqlite3 *db, const VdbeCursor *pCsr){

  94654.   VdbeSorter *pSorter;

  94655.   int rc;                         /* Return code */

  94656. 

  94657.   assert( pCsr->eCurType==CURTYPE_SORTER );

  94658.   pSorter = pCsr->uc.pSorter;

  94659.   assert( pSorter->bUsePMA || (pSorter->pReader==0 && pSorter->pMerger==0) );

  94660.   if( pSorter->bUsePMA ){

  94661.     assert( pSorter->pReader==0 || pSorter->pMerger==0 );

  94662.     assert( pSorter->bUseThreads==0 || pSorter->pReader );

  94663.     assert( pSorter->bUseThreads==1 || pSorter->pMerger );

  94664. #if SQLITE_MAX_WORKER_THREADS>0

  94665.     if( pSorter->bUseThreads ){

  94666.       rc = vdbePmaReaderNext(pSorter->pReader);

  94667.       if( rc==SQLITE_OK && pSorter->pReader->pFd==0 ) rc = SQLITE_DONE;

  94668.     }else

  94669. #endif

  94670.     /*if( !pSorter->bUseThreads )*/ {

  94671.       int res = 0;

  94672.       assert( pSorter->pMerger!=0 );

  94673.       assert( pSorter->pMerger->pTask==(&pSorter->aTask[0]) );

  94674.       rc = vdbeMergeEngineStep(pSorter->pMerger, &res);

  94675.       if( rc==SQLITE_OK && res ) rc = SQLITE_DONE;

  94676.     }

  94677.   }else{

  94678.     SorterRecord *pFree = pSorter->list.pList;

  94679.     pSorter->list.pList = pFree->u.pNext;

  94680.     pFree->u.pNext = 0;

  94681.     if( pSorter->list.aMemory==0 ) vdbeSorterRecordFree(db, pFree);

  94682.     rc = pSorter->list.pList ? SQLITE_OK : SQLITE_DONE;

  94683.   }

  94684.   return rc;

  94685. }

  94686. 

  94687. /*

  94688. ** Return a pointer to a buffer owned by the sorter that contains the 

  94689. ** current key.

  94690. */

  94691. static void *vdbeSorterRowkey(

  94692.   const VdbeSorter *pSorter,      /* Sorter object */

  94693.   int *pnKey                      /* OUT: Size of current key in bytes */

  94694. ){

  94695.   void *pKey;

  94696.   if( pSorter->bUsePMA ){

  94697.     PmaReader *pReader;

  94698. #if SQLITE_MAX_WORKER_THREADS>0

  94699.     if( pSorter->bUseThreads ){

  94700.       pReader = pSorter->pReader;

  94701.     }else

  94702. #endif

  94703.     /*if( !pSorter->bUseThreads )*/{

  94704.       pReader = &pSorter->pMerger->aReadr[pSorter->pMerger->aTree[1]];

  94705.     }

  94706.     *pnKey = pReader->nKey;

  94707.     pKey = pReader->aKey;

  94708.   }else{

  94709.     *pnKey = pSorter->list.pList->nVal;

  94710.     pKey = SRVAL(pSorter->list.pList);

  94711.   }

  94712.   return pKey;

  94713. }

  94714. 

  94715. /*

  94716. ** Copy the current sorter key into the memory cell pOut.

  94717. */

  94718. SQLITE_PRIVATE int sqlite3VdbeSorterRowkey(const VdbeCursor *pCsr, Mem *pOut){

  94719.   VdbeSorter *pSorter;

  94720.   void *pKey; int nKey;           /* Sorter key to copy into pOut */

  94721. 

  94722.   assert( pCsr->eCurType==CURTYPE_SORTER );

  94723.   pSorter = pCsr->uc.pSorter;

  94724.   pKey = vdbeSorterRowkey(pSorter, &nKey);

  94725.   if( sqlite3VdbeMemClearAndResize(pOut, nKey) ){

  94726.     return SQLITE_NOMEM_BKPT;

  94727.   }

  94728.   pOut->n = nKey;

  94729.   MemSetTypeFlag(pOut, MEM_Blob);

  94730.   memcpy(pOut->z, pKey, nKey);

  94731. 

  94732.   return SQLITE_OK;

  94733. }

  94734. 

  94735. /*

  94736. ** Compare the key in memory cell pVal with the key that the sorter cursor

  94737. ** passed as the first argument currently points to. For the purposes of

  94738. ** the comparison, ignore the rowid field at the end of each record.

  94739. **

  94740. ** If the sorter cursor key contains any NULL values, consider it to be

  94741. ** less than pVal. Even if pVal also contains NULL values.

  94742. **

  94743. ** If an error occurs, return an SQLite error code (i.e. SQLITE_NOMEM).

  94744. ** Otherwise, set *pRes to a negative, zero or positive value if the

  94745. ** key in pVal is smaller than, equal to or larger than the current sorter

  94746. ** key.

  94747. **

  94748. ** This routine forms the core of the OP_SorterCompare opcode, which in

  94749. ** turn is used to verify uniqueness when constructing a UNIQUE INDEX.

  94750. */

  94751. SQLITE_PRIVATE int sqlite3VdbeSorterCompare(

  94752.   const VdbeCursor *pCsr,         /* Sorter cursor */

  94753.   Mem *pVal,                      /* Value to compare to current sorter key */

  94754.   int nKeyCol,                    /* Compare this many columns */

  94755.   int *pRes                       /* OUT: Result of comparison */

  94756. ){

  94757.   VdbeSorter *pSorter;

  94758.   UnpackedRecord *r2;

  94759.   KeyInfo *pKeyInfo;

  94760.   int i;

  94761.   void *pKey; int nKey;           /* Sorter key to compare pVal with */

  94762. 

  94763.   assert( pCsr->eCurType==CURTYPE_SORTER );

  94764.   pSorter = pCsr->uc.pSorter;

  94765.   r2 = pSorter->pUnpacked;

  94766.   pKeyInfo = pCsr->pKeyInfo;

  94767.   if( r2==0 ){

  94768.     r2 = pSorter->pUnpacked = sqlite3VdbeAllocUnpackedRecord(pKeyInfo);

  94769.     if( r2==0 ) return SQLITE_NOMEM_BKPT;

  94770.     r2->nField = nKeyCol;

  94771.   }

  94772.   assert( r2->nField==nKeyCol );

  94773. 

  94774.   pKey = vdbeSorterRowkey(pSorter, &nKey);

  94775.   sqlite3VdbeRecordUnpack(pKeyInfo, nKey, pKey, r2);

  94776.   for(i=0; i<nKeyCol; i++){

  94777.     if( r2->aMem[i].flags & MEM_Null ){

  94778.       *pRes = -1;

  94779.       return SQLITE_OK;

  94780.     }

  94781.   }

  94782. 

  94783.   *pRes = sqlite3VdbeRecordCompare(pVal->n, pVal->z, r2);

  94784.   return SQLITE_OK;

  94785. }

  94786. 

  94787. /************** End of vdbesort.c ********************************************/

  94788. /************** Begin file memjournal.c **************************************/

  94789. /*

  94790. ** 2008 October 7

  94791. **

  94792. ** The author disclaims copyright to this source code.  In place of

  94793. ** a legal notice, here is a blessing:

  94794. **

  94795. **    May you do good and not evil.

  94796. **    May you find forgiveness for yourself and forgive others.

  94797. **    May you share freely, never taking more than you give.

  94798. **

  94799. *************************************************************************

  94800. **

  94801. ** This file contains code use to implement an in-memory rollback journal.

  94802. ** The in-memory rollback journal is used to journal transactions for

  94803. ** ":memory:" databases and when the journal_mode=MEMORY pragma is used.

  94804. **

  94805. ** Update:  The in-memory journal is also used to temporarily cache

  94806. ** smaller journals that are not critical for power-loss recovery.

  94807. ** For example, statement journals that are not too big will be held

  94808. ** entirely in memory, thus reducing the number of file I/O calls, and

  94809. ** more importantly, reducing temporary file creation events.  If these

  94810. ** journals become too large for memory, they are spilled to disk.  But

  94811. ** in the common case, they are usually small and no file I/O needs to

  94812. ** occur.

  94813. */

  94814. /* #include "sqliteInt.h" */

  94815. 

  94816. /* Forward references to internal structures */

  94817. typedef struct MemJournal MemJournal;

  94818. typedef struct FilePoint FilePoint;

  94819. typedef struct FileChunk FileChunk;

  94820. 

  94821. /*

  94822. ** The rollback journal is composed of a linked list of these structures.

  94823. **

  94824. ** The zChunk array is always at least 8 bytes in size - usually much more.

  94825. ** Its actual size is stored in the MemJournal.nChunkSize variable.

  94826. */

  94827. struct FileChunk {

  94828.   FileChunk *pNext;               /* Next chunk in the journal */

  94829.   u8 zChunk[8];                   /* Content of this chunk */

  94830. };

  94831. 

  94832. /*

  94833. ** By default, allocate this many bytes of memory for each FileChunk object.

  94834. */

  94835. #define MEMJOURNAL_DFLT_FILECHUNKSIZE 1024

  94836. 

  94837. /*

  94838. ** For chunk size nChunkSize, return the number of bytes that should

  94839. ** be allocated for each FileChunk structure.

  94840. */

  94841. #define fileChunkSize(nChunkSize) (sizeof(FileChunk) + ((nChunkSize)-8))

  94842. 

  94843. /*

  94844. ** An instance of this object serves as a cursor into the rollback journal.

  94845. ** The cursor can be either for reading or writing.

  94846. */

  94847. struct FilePoint {

  94848.   sqlite3_int64 iOffset;          /* Offset from the beginning of the file */

  94849.   FileChunk *pChunk;              /* Specific chunk into which cursor points */

  94850. };

  94851. 

  94852. /*

  94853. ** This structure is a subclass of sqlite3_file. Each open memory-journal

  94854. ** is an instance of this class.

  94855. */

  94856. struct MemJournal {

  94857.   const sqlite3_io_methods *pMethod; /* Parent class. MUST BE FIRST */

  94858.   int nChunkSize;                 /* In-memory chunk-size */

  94859. 

  94860.   int nSpill;                     /* Bytes of data before flushing */

  94861.   int nSize;                      /* Bytes of data currently in memory */

  94862.   FileChunk *pFirst;              /* Head of in-memory chunk-list */

  94863.   FilePoint endpoint;             /* Pointer to the end of the file */

  94864.   FilePoint readpoint;            /* Pointer to the end of the last xRead() */

  94865. 

  94866.   int flags;                      /* xOpen flags */

  94867.   sqlite3_vfs *pVfs;              /* The "real" underlying VFS */

  94868.   const char *zJournal;           /* Name of the journal file */

  94869. };

  94870. 

  94871. /*

  94872. ** Read data from the in-memory journal file.  This is the implementation

  94873. ** of the sqlite3_vfs.xRead method.

  94874. */

  94875. static int memjrnlRead(

  94876.   sqlite3_file *pJfd,    /* The journal file from which to read */

  94877.   void *zBuf,            /* Put the results here */

  94878.   int iAmt,              /* Number of bytes to read */

  94879.   sqlite_int64 iOfst     /* Begin reading at this offset */

  94880. ){

  94881.   MemJournal *p = (MemJournal *)pJfd;

  94882.   u8 *zOut = zBuf;

  94883.   int nRead = iAmt;

  94884.   int iChunkOffset;

  94885.   FileChunk *pChunk;

  94886. 

  94887. #if defined(SQLITE_ENABLE_ATOMIC_WRITE) \

  94888.  || defined(SQLITE_ENABLE_BATCH_ATOMIC_WRITE)

  94889.   if( (iAmt+iOfst)>p->endpoint.iOffset ){

  94890.     return SQLITE_IOERR_SHORT_READ;

  94891.   }

  94892. #endif

  94893. 

  94894.   assert( (iAmt+iOfst)<=p->endpoint.iOffset );

  94895.   assert( p->readpoint.iOffset==0 || p->readpoint.pChunk!=0 );

  94896.   if( p->readpoint.iOffset!=iOfst || iOfst==0 ){

  94897.     sqlite3_int64 iOff = 0;

  94898.     for(pChunk=p->pFirst; 

  94899.         ALWAYS(pChunk) && (iOff+p->nChunkSize)<=iOfst;

  94900.         pChunk=pChunk->pNext

  94901.     ){

  94902.       iOff += p->nChunkSize;

  94903.     }

  94904.   }else{

  94905.     pChunk = p->readpoint.pChunk;

  94906.     assert( pChunk!=0 );

  94907.   }

  94908. 

  94909.   iChunkOffset = (int)(iOfst%p->nChunkSize);

  94910.   do {

  94911.     int iSpace = p->nChunkSize - iChunkOffset;

  94912.     int nCopy = MIN(nRead, (p->nChunkSize - iChunkOffset));

  94913.     memcpy(zOut, (u8*)pChunk->zChunk + iChunkOffset, nCopy);

  94914.     zOut += nCopy;

  94915.     nRead -= iSpace;

  94916.     iChunkOffset = 0;

  94917.   } while( nRead>=0 && (pChunk=pChunk->pNext)!=0 && nRead>0 );

  94918.   p->readpoint.iOffset = pChunk ? iOfst+iAmt : 0;

  94919.   p->readpoint.pChunk = pChunk;

  94920. 

  94921.   return SQLITE_OK;

  94922. }

  94923. 

  94924. /*

  94925. ** Free the list of FileChunk structures headed at MemJournal.pFirst.

  94926. */

  94927. static void memjrnlFreeChunks(MemJournal *p){

  94928.   FileChunk *pIter;

  94929.   FileChunk *pNext;

  94930.   for(pIter=p->pFirst; pIter; pIter=pNext){

  94931.     pNext = pIter->pNext;

  94932.     sqlite3_free(pIter);

  94933.   } 

  94934.   p->pFirst = 0;

  94935. }

  94936. 

  94937. /*

  94938. ** Flush the contents of memory to a real file on disk.

  94939. */

  94940. static int memjrnlCreateFile(MemJournal *p){

  94941.   int rc;

  94942.   sqlite3_file *pReal = (sqlite3_file*)p;

  94943.   MemJournal copy = *p;

  94944. 

  94945.   memset(p, 0, sizeof(MemJournal));

  94946.   rc = sqlite3OsOpen(copy.pVfs, copy.zJournal, pReal, copy.flags, 0);

  94947.   if( rc==SQLITE_OK ){

  94948.     int nChunk = copy.nChunkSize;

  94949.     i64 iOff = 0;

  94950.     FileChunk *pIter;

  94951.     for(pIter=copy.pFirst; pIter; pIter=pIter->pNext){

  94952.       if( iOff + nChunk > copy.endpoint.iOffset ){

  94953.         nChunk = copy.endpoint.iOffset - iOff;

  94954.       }

  94955.       rc = sqlite3OsWrite(pReal, (u8*)pIter->zChunk, nChunk, iOff);

  94956.       if( rc ) break;

  94957.       iOff += nChunk;

  94958.     }

  94959.     if( rc==SQLITE_OK ){

  94960.       /* No error has occurred. Free the in-memory buffers. */

  94961.       memjrnlFreeChunks(&copy);

  94962.     }

  94963.   }

  94964.   if( rc!=SQLITE_OK ){

  94965.     /* If an error occurred while creating or writing to the file, restore

  94966.     ** the original before returning. This way, SQLite uses the in-memory

  94967.     ** journal data to roll back changes made to the internal page-cache

  94968.     ** before this function was called.  */

  94969.     sqlite3OsClose(pReal);

  94970.     *p = copy;

  94971.   }

  94972.   return rc;

  94973. }

  94974. 

  94975. 

  94976. /*

  94977. ** Write data to the file.

  94978. */

  94979. static int memjrnlWrite(

  94980.   sqlite3_file *pJfd,    /* The journal file into which to write */

  94981.   const void *zBuf,      /* Take data to be written from here */

  94982.   int iAmt,              /* Number of bytes to write */

  94983.   sqlite_int64 iOfst     /* Begin writing at this offset into the file */

  94984. ){

  94985.   MemJournal *p = (MemJournal *)pJfd;

  94986.   int nWrite = iAmt;

  94987.   u8 *zWrite = (u8 *)zBuf;

  94988. 

  94989.   /* If the file should be created now, create it and write the new data

  94990.   ** into the file on disk. */

  94991.   if( p->nSpill>0 && (iAmt+iOfst)>p->nSpill ){

  94992.     int rc = memjrnlCreateFile(p);

  94993.     if( rc==SQLITE_OK ){

  94994.       rc = sqlite3OsWrite(pJfd, zBuf, iAmt, iOfst);

  94995.     }

  94996.     return rc;

  94997.   }

  94998. 

  94999.   /* If the contents of this write should be stored in memory */

  95000.   else{

  95001.     /* An in-memory journal file should only ever be appended to. Random

  95002.     ** access writes are not required. The only exception to this is when

  95003.     ** the in-memory journal is being used by a connection using the

  95004.     ** atomic-write optimization. In this case the first 28 bytes of the

  95005.     ** journal file may be written as part of committing the transaction. */ 

  95006.     assert( iOfst==p->endpoint.iOffset || iOfst==0 );

  95007. #if defined(SQLITE_ENABLE_ATOMIC_WRITE) \

  95008.  || defined(SQLITE_ENABLE_BATCH_ATOMIC_WRITE)

  95009.     if( iOfst==0 && p->pFirst ){

  95010.       assert( p->nChunkSize>iAmt );

  95011.       memcpy((u8*)p->pFirst->zChunk, zBuf, iAmt);

  95012.     }else

  95013. #else

  95014.     assert( iOfst>0 || p->pFirst==0 );

  95015. #endif

  95016.     {

  95017.       while( nWrite>0 ){

  95018.         FileChunk *pChunk = p->endpoint.pChunk;

  95019.         int iChunkOffset = (int)(p->endpoint.iOffset%p->nChunkSize);

  95020.         int iSpace = MIN(nWrite, p->nChunkSize - iChunkOffset);

  95021. 

  95022.         if( iChunkOffset==0 ){

  95023.           /* New chunk is required to extend the file. */

  95024.           FileChunk *pNew = sqlite3_malloc(fileChunkSize(p->nChunkSize));

  95025.           if( !pNew ){

  95026.             return SQLITE_IOERR_NOMEM_BKPT;

  95027.           }

  95028.           pNew->pNext = 0;

  95029.           if( pChunk ){

  95030.             assert( p->pFirst );

  95031.             pChunk->pNext = pNew;

  95032.           }else{

  95033.             assert( !p->pFirst );

  95034.             p->pFirst = pNew;

  95035.           }

  95036.           p->endpoint.pChunk = pNew;

  95037.         }

  95038. 

  95039.         memcpy((u8*)p->endpoint.pChunk->zChunk + iChunkOffset, zWrite, iSpace);

  95040.         zWrite += iSpace;

  95041.         nWrite -= iSpace;

  95042.         p->endpoint.iOffset += iSpace;

  95043.       }

  95044.       p->nSize = iAmt + iOfst;

  95045.     }

  95046.   }

  95047. 

  95048.   return SQLITE_OK;

  95049. }

  95050. 

  95051. /*

  95052. ** Truncate the file.

  95053. **

  95054. ** If the journal file is already on disk, truncate it there. Or, if it

  95055. ** is still in main memory but is being truncated to zero bytes in size,

  95056. ** ignore 

  95057. */

  95058. static int memjrnlTruncate(sqlite3_file *pJfd, sqlite_int64 size){

  95059.   MemJournal *p = (MemJournal *)pJfd;

  95060.   if( ALWAYS(size==0) ){

  95061.     memjrnlFreeChunks(p);

  95062.     p->nSize = 0;

  95063.     p->endpoint.pChunk = 0;

  95064.     p->endpoint.iOffset = 0;

  95065.     p->readpoint.pChunk = 0;

  95066.     p->readpoint.iOffset = 0;

  95067.   }

  95068.   return SQLITE_OK;

  95069. }

  95070. 

  95071. /*

  95072. ** Close the file.

  95073. */

  95074. static int memjrnlClose(sqlite3_file *pJfd){

  95075.   MemJournal *p = (MemJournal *)pJfd;

  95076.   memjrnlFreeChunks(p);

  95077.   return SQLITE_OK;

  95078. }

  95079. 

  95080. /*

  95081. ** Sync the file.

  95082. **

  95083. ** If the real file has been created, call its xSync method. Otherwise, 

  95084. ** syncing an in-memory journal is a no-op. 

  95085. */

  95086. static int memjrnlSync(sqlite3_file *pJfd, int flags){

  95087.   UNUSED_PARAMETER2(pJfd, flags);

  95088.   return SQLITE_OK;

  95089. }

  95090. 

  95091. /*

  95092. ** Query the size of the file in bytes.

  95093. */

  95094. static int memjrnlFileSize(sqlite3_file *pJfd, sqlite_int64 *pSize){

  95095.   MemJournal *p = (MemJournal *)pJfd;

  95096.   *pSize = (sqlite_int64) p->endpoint.iOffset;

  95097.   return SQLITE_OK;

  95098. }

  95099. 

  95100. /*

  95101. ** Table of methods for MemJournal sqlite3_file object.

  95102. */

  95103. static const struct sqlite3_io_methods MemJournalMethods = {

  95104.   1,                /* iVersion */

  95105.   memjrnlClose,     /* xClose */

  95106.   memjrnlRead,      /* xRead */

  95107.   memjrnlWrite,     /* xWrite */

  95108.   memjrnlTruncate,  /* xTruncate */

  95109.   memjrnlSync,      /* xSync */

  95110.   memjrnlFileSize,  /* xFileSize */

  95111.   0,                /* xLock */

  95112.   0,                /* xUnlock */

  95113.   0,                /* xCheckReservedLock */

  95114.   0,                /* xFileControl */

  95115.   0,                /* xSectorSize */

  95116.   0,                /* xDeviceCharacteristics */

  95117.   0,                /* xShmMap */

  95118.   0,                /* xShmLock */

  95119.   0,                /* xShmBarrier */

  95120.   0,                /* xShmUnmap */

  95121.   0,                /* xFetch */

  95122.   0                 /* xUnfetch */

  95123. };

  95124. 

  95125. /* 

  95126. ** Open a journal file. 

  95127. **

  95128. ** The behaviour of the journal file depends on the value of parameter 

  95129. ** nSpill. If nSpill is 0, then the journal file is always create and 

  95130. ** accessed using the underlying VFS. If nSpill is less than zero, then

  95131. ** all content is always stored in main-memory. Finally, if nSpill is a

  95132. ** positive value, then the journal file is initially created in-memory

  95133. ** but may be flushed to disk later on. In this case the journal file is

  95134. ** flushed to disk either when it grows larger than nSpill bytes in size,

  95135. ** or when sqlite3JournalCreate() is called.

  95136. */

  95137. SQLITE_PRIVATE int sqlite3JournalOpen(

  95138.   sqlite3_vfs *pVfs,         /* The VFS to use for actual file I/O */

  95139.   const char *zName,         /* Name of the journal file */

  95140.   sqlite3_file *pJfd,        /* Preallocated, blank file handle */

  95141.   int flags,                 /* Opening flags */

  95142.   int nSpill                 /* Bytes buffered before opening the file */

  95143. ){

  95144.   MemJournal *p = (MemJournal*)pJfd;

  95145. 

  95146.   /* Zero the file-handle object. If nSpill was passed zero, initialize

  95147.   ** it using the sqlite3OsOpen() function of the underlying VFS. In this

  95148.   ** case none of the code in this module is executed as a result of calls

  95149.   ** made on the journal file-handle.  */

  95150.   memset(p, 0, sizeof(MemJournal));

  95151.   if( nSpill==0 ){

  95152.     return sqlite3OsOpen(pVfs, zName, pJfd, flags, 0);

  95153.   }

  95154. 

  95155.   if( nSpill>0 ){

  95156.     p->nChunkSize = nSpill;

  95157.   }else{

  95158.     p->nChunkSize = 8 + MEMJOURNAL_DFLT_FILECHUNKSIZE - sizeof(FileChunk);

  95159.     assert( MEMJOURNAL_DFLT_FILECHUNKSIZE==fileChunkSize(p->nChunkSize) );

  95160.   }

  95161. 

  95162.   p->pMethod = (const sqlite3_io_methods*)&MemJournalMethods;

  95163.   p->nSpill = nSpill;

  95164.   p->flags = flags;

  95165.   p->zJournal = zName;

  95166.   p->pVfs = pVfs;

  95167.   return SQLITE_OK;

  95168. }

  95169. 

  95170. /*

  95171. ** Open an in-memory journal file.

  95172. */

  95173. SQLITE_PRIVATE void sqlite3MemJournalOpen(sqlite3_file *pJfd){

  95174.   sqlite3JournalOpen(0, 0, pJfd, 0, -1);

  95175. }

  95176. 

  95177. #if defined(SQLITE_ENABLE_ATOMIC_WRITE) \

  95178.  || defined(SQLITE_ENABLE_BATCH_ATOMIC_WRITE)

  95179. /*

  95180. ** If the argument p points to a MemJournal structure that is not an 

  95181. ** in-memory-only journal file (i.e. is one that was opened with a +ve

  95182. ** nSpill parameter or as SQLITE_OPEN_MAIN_JOURNAL), and the underlying 

  95183. ** file has not yet been created, create it now.

  95184. */

  95185. SQLITE_PRIVATE int sqlite3JournalCreate(sqlite3_file *pJfd){

  95186.   int rc = SQLITE_OK;

  95187.   MemJournal *p = (MemJournal*)pJfd;

  95188.   if( p->pMethod==&MemJournalMethods && (

  95189. #ifdef SQLITE_ENABLE_ATOMIC_WRITE

  95190.      p->nSpill>0

  95191. #else

  95192.      /* While this appears to not be possible without ATOMIC_WRITE, the

  95193.      ** paths are complex, so it seems prudent to leave the test in as

  95194.      ** a NEVER(), in case our analysis is subtly flawed. */

  95195.      NEVER(p->nSpill>0)

  95196. #endif

  95197. #ifdef SQLITE_ENABLE_BATCH_ATOMIC_WRITE

  95198.      || (p->flags & SQLITE_OPEN_MAIN_JOURNAL)

  95199. #endif

  95200.   )){

  95201.     rc = memjrnlCreateFile(p);

  95202.   }

  95203.   return rc;

  95204. }

  95205. #endif

  95206. 

  95207. /*

  95208. ** The file-handle passed as the only argument is open on a journal file.

  95209. ** Return true if this "journal file" is currently stored in heap memory,

  95210. ** or false otherwise.

  95211. */

  95212. SQLITE_PRIVATE int sqlite3JournalIsInMemory(sqlite3_file *p){

  95213.   return p->pMethods==&MemJournalMethods;

  95214. }

  95215. 

  95216. /* 

  95217. ** Return the number of bytes required to store a JournalFile that uses vfs

  95218. ** pVfs to create the underlying on-disk files.

  95219. */

  95220. SQLITE_PRIVATE int sqlite3JournalSize(sqlite3_vfs *pVfs){

  95221.   return MAX(pVfs->szOsFile, (int)sizeof(MemJournal));

  95222. }

  95223. 

  95224. /************** End of memjournal.c ******************************************/

  95225. /************** Begin file walker.c ******************************************/

  95226. /*

  95227. ** 2008 August 16

  95228. **

  95229. ** The author disclaims copyright to this source code.  In place of

  95230. ** a legal notice, here is a blessing:

  95231. **

  95232. **    May you do good and not evil.

  95233. **    May you find forgiveness for yourself and forgive others.

  95234. **    May you share freely, never taking more than you give.

  95235. **

  95236. *************************************************************************

  95237. ** This file contains routines used for walking the parser tree for

  95238. ** an SQL statement.

  95239. */

  95240. /* #include "sqliteInt.h" */

  95241. /* #include <stdlib.h> */

  95242. /* #include <string.h> */

  95243. 

  95244. 

  95245. #if !defined(SQLITE_OMIT_WINDOWFUNC)

  95246. /*

  95247. ** Walk all expressions linked into the list of Window objects passed

  95248. ** as the second argument.

  95249. */

  95250. static int walkWindowList(Walker *pWalker, Window *pList){

  95251.   Window *pWin;

  95252.   for(pWin=pList; pWin; pWin=pWin->pNextWin){

  95253.     if( sqlite3WalkExprList(pWalker, pWin->pOrderBy) ) return WRC_Abort;

  95254.     if( sqlite3WalkExprList(pWalker, pWin->pPartition) ) return WRC_Abort;

  95255.     if( sqlite3WalkExpr(pWalker, pWin->pFilter) ) return WRC_Abort;

  95256.   }

  95257.   return WRC_Continue;

  95258. }

  95259. #endif

  95260. 

  95261. /*

  95262. ** Walk an expression tree.  Invoke the callback once for each node

  95263. ** of the expression, while descending.  (In other words, the callback

  95264. ** is invoked before visiting children.)

  95265. **

  95266. ** The return value from the callback should be one of the WRC_*

  95267. ** constants to specify how to proceed with the walk.

  95268. **

  95269. **    WRC_Continue      Continue descending down the tree.

  95270. **

  95271. **    WRC_Prune         Do not descend into child nodes, but allow

  95272. **                      the walk to continue with sibling nodes.

  95273. **

  95274. **    WRC_Abort         Do no more callbacks.  Unwind the stack and

  95275. **                      return from the top-level walk call.

  95276. **

  95277. ** The return value from this routine is WRC_Abort to abandon the tree walk

  95278. ** and WRC_Continue to continue.

  95279. */

  95280. static SQLITE_NOINLINE int walkExpr(Walker *pWalker, Expr *pExpr){

  95281.   int rc;

  95282.   testcase( ExprHasProperty(pExpr, EP_TokenOnly) );

  95283.   testcase( ExprHasProperty(pExpr, EP_Reduced) );

  95284.   while(1){

  95285.     rc = pWalker->xExprCallback(pWalker, pExpr);

  95286.     if( rc ) return rc & WRC_Abort;

  95287.     if( !ExprHasProperty(pExpr,(EP_TokenOnly|EP_Leaf)) ){

  95288.       if( pExpr->pLeft && walkExpr(pWalker, pExpr->pLeft) ) return WRC_Abort;

  95289.        assert( pExpr->x.pList==0 || pExpr->pRight==0 );

  95290.       if( pExpr->pRight ){

  95291.         pExpr = pExpr->pRight;

  95292.         continue;

  95293.       }else if( ExprHasProperty(pExpr, EP_xIsSelect) ){

  95294.         if( sqlite3WalkSelect(pWalker, pExpr->x.pSelect) ) return WRC_Abort;

  95295.       }else if( pExpr->x.pList ){

  95296.         if( sqlite3WalkExprList(pWalker, pExpr->x.pList) ) return WRC_Abort;

  95297.       }

  95298. #ifndef SQLITE_OMIT_WINDOWFUNC

  95299.       if( ExprHasProperty(pExpr, EP_WinFunc) ){

  95300.         if( walkWindowList(pWalker, pExpr->y.pWin) ) return WRC_Abort;

  95301.       }

  95302. #endif

  95303.     }

  95304.     break;

  95305.   }

  95306.   return WRC_Continue;

  95307. }

  95308. SQLITE_PRIVATE int sqlite3WalkExpr(Walker *pWalker, Expr *pExpr){

  95309.   return pExpr ? walkExpr(pWalker,pExpr) : WRC_Continue;

  95310. }

  95311. 

  95312. /*

  95313. ** Call sqlite3WalkExpr() for every expression in list p or until

  95314. ** an abort request is seen.

  95315. */

  95316. SQLITE_PRIVATE int sqlite3WalkExprList(Walker *pWalker, ExprList *p){

  95317.   int i;

  95318.   struct ExprList_item *pItem;

  95319.   if( p ){

  95320.     for(i=p->nExpr, pItem=p->a; i>0; i--, pItem++){

  95321.       if( sqlite3WalkExpr(pWalker, pItem->pExpr) ) return WRC_Abort;

  95322.     }

  95323.   }

  95324.   return WRC_Continue;

  95325. }

  95326. 

  95327. /*

  95328. ** Walk all expressions associated with SELECT statement p.  Do

  95329. ** not invoke the SELECT callback on p, but do (of course) invoke

  95330. ** any expr callbacks and SELECT callbacks that come from subqueries.

  95331. ** Return WRC_Abort or WRC_Continue.

  95332. */

  95333. SQLITE_PRIVATE int sqlite3WalkSelectExpr(Walker *pWalker, Select *p){

  95334.   if( sqlite3WalkExprList(pWalker, p->pEList) ) return WRC_Abort;

  95335.   if( sqlite3WalkExpr(pWalker, p->pWhere) ) return WRC_Abort;

  95336.   if( sqlite3WalkExprList(pWalker, p->pGroupBy) ) return WRC_Abort;

  95337.   if( sqlite3WalkExpr(pWalker, p->pHaving) ) return WRC_Abort;

  95338.   if( sqlite3WalkExprList(pWalker, p->pOrderBy) ) return WRC_Abort;

  95339.   if( sqlite3WalkExpr(pWalker, p->pLimit) ) return WRC_Abort;

  95340. #if !defined(SQLITE_OMIT_WINDOWFUNC) && !defined(SQLITE_OMIT_ALTERTABLE)

  95341.   {

  95342.     Parse *pParse = pWalker->pParse;

  95343.     if( pParse && IN_RENAME_OBJECT ){

  95344.       int rc = walkWindowList(pWalker, p->pWinDefn);

  95345.       assert( rc==WRC_Continue );

  95346.       return rc;

  95347.     }

  95348.   }

  95349. #endif

  95350.   return WRC_Continue;

  95351. }

  95352. 

  95353. /*

  95354. ** Walk the parse trees associated with all subqueries in the

  95355. ** FROM clause of SELECT statement p.  Do not invoke the select

  95356. ** callback on p, but do invoke it on each FROM clause subquery

  95357. ** and on any subqueries further down in the tree.  Return 

  95358. ** WRC_Abort or WRC_Continue;

  95359. */

  95360. SQLITE_PRIVATE int sqlite3WalkSelectFrom(Walker *pWalker, Select *p){

  95361.   SrcList *pSrc;

  95362.   int i;

  95363.   struct SrcList_item *pItem;

  95364. 

  95365.   pSrc = p->pSrc;

  95366.   assert( pSrc!=0 );

  95367.   for(i=pSrc->nSrc, pItem=pSrc->a; i>0; i--, pItem++){

  95368.     if( pItem->pSelect && sqlite3WalkSelect(pWalker, pItem->pSelect) ){

  95369.       return WRC_Abort;

  95370.     }

  95371.     if( pItem->fg.isTabFunc

  95372.      && sqlite3WalkExprList(pWalker, pItem->u1.pFuncArg)

  95373.     ){

  95374.       return WRC_Abort;

  95375.     }

  95376.   }

  95377.   return WRC_Continue;

  95378. } 

  95379. 

  95380. /*

  95381. ** Call sqlite3WalkExpr() for every expression in Select statement p.

  95382. ** Invoke sqlite3WalkSelect() for subqueries in the FROM clause and

  95383. ** on the compound select chain, p->pPrior. 

  95384. **

  95385. ** If it is not NULL, the xSelectCallback() callback is invoked before

  95386. ** the walk of the expressions and FROM clause. The xSelectCallback2()

  95387. ** method is invoked following the walk of the expressions and FROM clause,

  95388. ** but only if both xSelectCallback and xSelectCallback2 are both non-NULL

  95389. ** and if the expressions and FROM clause both return WRC_Continue;

  95390. **

  95391. ** Return WRC_Continue under normal conditions.  Return WRC_Abort if

  95392. ** there is an abort request.

  95393. **

  95394. ** If the Walker does not have an xSelectCallback() then this routine

  95395. ** is a no-op returning WRC_Continue.

  95396. */

  95397. SQLITE_PRIVATE int sqlite3WalkSelect(Walker *pWalker, Select *p){

  95398.   int rc;

  95399.   if( p==0 ) return WRC_Continue;

  95400.   if( pWalker->xSelectCallback==0 ) return WRC_Continue;

  95401.   do{

  95402.     rc = pWalker->xSelectCallback(pWalker, p);

  95403.     if( rc ) return rc & WRC_Abort;

  95404.     if( sqlite3WalkSelectExpr(pWalker, p)

  95405.      || sqlite3WalkSelectFrom(pWalker, p)

  95406.     ){

  95407.       return WRC_Abort;

  95408.     }

  95409.     if( pWalker->xSelectCallback2 ){

  95410.       pWalker->xSelectCallback2(pWalker, p);

  95411.     }

  95412.     p = p->pPrior;

  95413.   }while( p!=0 );

  95414.   return WRC_Continue;

  95415. }

  95416. 

  95417. /************** End of walker.c **********************************************/

  95418. /************** Begin file resolve.c *****************************************/

  95419. /*

  95420. ** 2008 August 18

  95421. **

  95422. ** The author disclaims copyright to this source code.  In place of

  95423. ** a legal notice, here is a blessing:

  95424. **

  95425. **    May you do good and not evil.

  95426. **    May you find forgiveness for yourself and forgive others.

  95427. **    May you share freely, never taking more than you give.

  95428. **

  95429. *************************************************************************

  95430. **

  95431. ** This file contains routines used for walking the parser tree and

  95432. ** resolve all identifiers by associating them with a particular

  95433. ** table and column.

  95434. */

  95435. /* #include "sqliteInt.h" */

  95436. 

  95437. /*

  95438. ** Walk the expression tree pExpr and increase the aggregate function

  95439. ** depth (the Expr.op2 field) by N on every TK_AGG_FUNCTION node.

  95440. ** This needs to occur when copying a TK_AGG_FUNCTION node from an

  95441. ** outer query into an inner subquery.

  95442. **

  95443. ** incrAggFunctionDepth(pExpr,n) is the main routine.  incrAggDepth(..)

  95444. ** is a helper function - a callback for the tree walker.

  95445. */

  95446. static int incrAggDepth(Walker *pWalker, Expr *pExpr){

  95447.   if( pExpr->op==TK_AGG_FUNCTION ) pExpr->op2 += pWalker->u.n;

  95448.   return WRC_Continue;

  95449. }

  95450. static void incrAggFunctionDepth(Expr *pExpr, int N){

  95451.   if( N>0 ){

  95452.     Walker w;

  95453.     memset(&w, 0, sizeof(w));

  95454.     w.xExprCallback = incrAggDepth;

  95455.     w.u.n = N;

  95456.     sqlite3WalkExpr(&w, pExpr);

  95457.   }

  95458. }

  95459. 

  95460. /*

  95461. ** Turn the pExpr expression into an alias for the iCol-th column of the

  95462. ** result set in pEList.

  95463. **

  95464. ** If the reference is followed by a COLLATE operator, then make sure

  95465. ** the COLLATE operator is preserved.  For example:

  95466. **

  95467. **     SELECT a+b, c+d FROM t1 ORDER BY 1 COLLATE nocase;

  95468. **

  95469. ** Should be transformed into:

  95470. **

  95471. **     SELECT a+b, c+d FROM t1 ORDER BY (a+b) COLLATE nocase;

  95472. **

  95473. ** The nSubquery parameter specifies how many levels of subquery the

  95474. ** alias is removed from the original expression.  The usual value is

  95475. ** zero but it might be more if the alias is contained within a subquery

  95476. ** of the original expression.  The Expr.op2 field of TK_AGG_FUNCTION

  95477. ** structures must be increased by the nSubquery amount.

  95478. */

  95479. static void resolveAlias(

  95480.   Parse *pParse,         /* Parsing context */

  95481.   ExprList *pEList,      /* A result set */

  95482.   int iCol,              /* A column in the result set.  0..pEList->nExpr-1 */

  95483.   Expr *pExpr,           /* Transform this into an alias to the result set */

  95484.   const char *zType,     /* "GROUP" or "ORDER" or "" */

  95485.   int nSubquery          /* Number of subqueries that the label is moving */

  95486. ){

  95487.   Expr *pOrig;           /* The iCol-th column of the result set */

  95488.   Expr *pDup;            /* Copy of pOrig */

  95489.   sqlite3 *db;           /* The database connection */

  95490. 

  95491.   assert( iCol>=0 && iCol<pEList->nExpr );

  95492.   pOrig = pEList->a[iCol].pExpr;

  95493.   assert( pOrig!=0 );

  95494.   db = pParse->db;

  95495.   pDup = sqlite3ExprDup(db, pOrig, 0);

  95496.   if( pDup!=0 ){

  95497.     if( zType[0]!='G' ) incrAggFunctionDepth(pDup, nSubquery);

  95498.     if( pExpr->op==TK_COLLATE ){

  95499.       pDup = sqlite3ExprAddCollateString(pParse, pDup, pExpr->u.zToken);

  95500.     }

  95501. 

  95502.     /* Before calling sqlite3ExprDelete(), set the EP_Static flag. This 

  95503.     ** prevents ExprDelete() from deleting the Expr structure itself,

  95504.     ** allowing it to be repopulated by the memcpy() on the following line.

  95505.     ** The pExpr->u.zToken might point into memory that will be freed by the

  95506.     ** sqlite3DbFree(db, pDup) on the last line of this block, so be sure to

  95507.     ** make a copy of the token before doing the sqlite3DbFree().

  95508.     */

  95509.     ExprSetProperty(pExpr, EP_Static);

  95510.     sqlite3ExprDelete(db, pExpr);

  95511.     memcpy(pExpr, pDup, sizeof(*pExpr));

  95512.     if( !ExprHasProperty(pExpr, EP_IntValue) && pExpr->u.zToken!=0 ){

  95513.       assert( (pExpr->flags & (EP_Reduced|EP_TokenOnly))==0 );

  95514.       pExpr->u.zToken = sqlite3DbStrDup(db, pExpr->u.zToken);

  95515.       pExpr->flags |= EP_MemToken;

  95516.     }

  95517.     sqlite3DbFree(db, pDup);

  95518.   }

  95519.   ExprSetProperty(pExpr, EP_Alias);

  95520. }

  95521. 

  95522. 

  95523. /*

  95524. ** Return TRUE if the name zCol occurs anywhere in the USING clause.

  95525. **

  95526. ** Return FALSE if the USING clause is NULL or if it does not contain

  95527. ** zCol.

  95528. */

  95529. static int nameInUsingClause(IdList *pUsing, const char *zCol){

  95530.   if( pUsing ){

  95531.     int k;

  95532.     for(k=0; k<pUsing->nId; k++){

  95533.       if( sqlite3StrICmp(pUsing->a[k].zName, zCol)==0 ) return 1;

  95534.     }

  95535.   }

  95536.   return 0;

  95537. }

  95538. 

  95539. /*

  95540. ** Subqueries stores the original database, table and column names for their

  95541. ** result sets in ExprList.a[].zSpan, in the form "DATABASE.TABLE.COLUMN".

  95542. ** Check to see if the zSpan given to this routine matches the zDb, zTab,

  95543. ** and zCol.  If any of zDb, zTab, and zCol are NULL then those fields will

  95544. ** match anything.

  95545. */

  95546. SQLITE_PRIVATE int sqlite3MatchSpanName(

  95547.   const char *zSpan,

  95548.   const char *zCol,

  95549.   const char *zTab,

  95550.   const char *zDb

  95551. ){

  95552.   int n;

  95553.   for(n=0; ALWAYS(zSpan[n]) && zSpan[n]!='.'; n++){}

  95554.   if( zDb && (sqlite3StrNICmp(zSpan, zDb, n)!=0 || zDb[n]!=0) ){

  95555.     return 0;

  95556.   }

  95557.   zSpan += n+1;

  95558.   for(n=0; ALWAYS(zSpan[n]) && zSpan[n]!='.'; n++){}

  95559.   if( zTab && (sqlite3StrNICmp(zSpan, zTab, n)!=0 || zTab[n]!=0) ){

  95560.     return 0;

  95561.   }

  95562.   zSpan += n+1;

  95563.   if( zCol && sqlite3StrICmp(zSpan, zCol)!=0 ){

  95564.     return 0;

  95565.   }

  95566.   return 1;

  95567. }

  95568. 

  95569. /*

  95570. ** Return TRUE if the double-quoted string  mis-feature should be supported.

  95571. */

  95572. static int areDoubleQuotedStringsEnabled(sqlite3 *db, NameContext *pTopNC){

  95573.   if( db->init.busy ) return 1;  /* Always support for legacy schemas */

  95574.   if( pTopNC->ncFlags & NC_IsDDL ){

  95575.     /* Currently parsing a DDL statement */

  95576.     if( sqlite3WritableSchema(db) && (db->flags & SQLITE_DqsDML)!=0 ){

  95577.       return 1;

  95578.     }

  95579.     return (db->flags & SQLITE_DqsDDL)!=0;

  95580.   }else{

  95581.     /* Currently parsing a DML statement */

  95582.     return (db->flags & SQLITE_DqsDML)!=0;

  95583.   }

  95584. }

  95585. 

  95586. /*

  95587. ** Given the name of a column of the form X.Y.Z or Y.Z or just Z, look up

  95588. ** that name in the set of source tables in pSrcList and make the pExpr 

  95589. ** expression node refer back to that source column.  The following changes

  95590. ** are made to pExpr:

  95591. **

  95592. **    pExpr->iDb           Set the index in db->aDb[] of the database X

  95593. **                         (even if X is implied).

  95594. **    pExpr->iTable        Set to the cursor number for the table obtained

  95595. **                         from pSrcList.

  95596. **    pExpr->y.pTab        Points to the Table structure of X.Y (even if

  95597. **                         X and/or Y are implied.)

  95598. **    pExpr->iColumn       Set to the column number within the table.

  95599. **    pExpr->op            Set to TK_COLUMN.

  95600. **    pExpr->pLeft         Any expression this points to is deleted

  95601. **    pExpr->pRight        Any expression this points to is deleted.

  95602. **

  95603. ** The zDb variable is the name of the database (the "X").  This value may be

  95604. ** NULL meaning that name is of the form Y.Z or Z.  Any available database

  95605. ** can be used.  The zTable variable is the name of the table (the "Y").  This

  95606. ** value can be NULL if zDb is also NULL.  If zTable is NULL it

  95607. ** means that the form of the name is Z and that columns from any table

  95608. ** can be used.

  95609. **

  95610. ** If the name cannot be resolved unambiguously, leave an error message

  95611. ** in pParse and return WRC_Abort.  Return WRC_Prune on success.

  95612. */

  95613. static int lookupName(

  95614.   Parse *pParse,       /* The parsing context */

  95615.   const char *zDb,     /* Name of the database containing table, or NULL */

  95616.   const char *zTab,    /* Name of table containing column, or NULL */

  95617.   const char *zCol,    /* Name of the column. */

  95618.   NameContext *pNC,    /* The name context used to resolve the name */

  95619.   Expr *pExpr          /* Make this EXPR node point to the selected column */

  95620. ){

  95621.   int i, j;                         /* Loop counters */

  95622.   int cnt = 0;                      /* Number of matching column names */

  95623.   int cntTab = 0;                   /* Number of matching table names */

  95624.   int nSubquery = 0;                /* How many levels of subquery */

  95625.   sqlite3 *db = pParse->db;         /* The database connection */

  95626.   struct SrcList_item *pItem;       /* Use for looping over pSrcList items */

  95627.   struct SrcList_item *pMatch = 0;  /* The matching pSrcList item */

  95628.   NameContext *pTopNC = pNC;        /* First namecontext in the list */

  95629.   Schema *pSchema = 0;              /* Schema of the expression */

  95630.   int eNewExprOp = TK_COLUMN;       /* New value for pExpr->op on success */

  95631.   Table *pTab = 0;                  /* Table hold the row */

  95632.   Column *pCol;                     /* A column of pTab */

  95633. 

  95634.   assert( pNC );     /* the name context cannot be NULL. */

  95635.   assert( zCol );    /* The Z in X.Y.Z cannot be NULL */

  95636.   assert( !ExprHasProperty(pExpr, EP_TokenOnly|EP_Reduced) );

  95637. 

  95638.   /* Initialize the node to no-match */

  95639.   pExpr->iTable = -1;

  95640.   ExprSetVVAProperty(pExpr, EP_NoReduce);

  95641. 

  95642.   /* Translate the schema name in zDb into a pointer to the corresponding

  95643.   ** schema.  If not found, pSchema will remain NULL and nothing will match

  95644.   ** resulting in an appropriate error message toward the end of this routine

  95645.   */

  95646.   if( zDb ){

  95647.     testcase( pNC->ncFlags & NC_PartIdx );

  95648.     testcase( pNC->ncFlags & NC_IsCheck );

  95649.     if( (pNC->ncFlags & (NC_PartIdx|NC_IsCheck))!=0 ){

  95650.       /* Silently ignore database qualifiers inside CHECK constraints and

  95651.       ** partial indices.  Do not raise errors because that might break

  95652.       ** legacy and because it does not hurt anything to just ignore the

  95653.       ** database name. */

  95654.       zDb = 0;

  95655.     }else{

  95656.       for(i=0; i<db->nDb; i++){

  95657.         assert( db->aDb[i].zDbSName );

  95658.         if( sqlite3StrICmp(db->aDb[i].zDbSName,zDb)==0 ){

  95659.           pSchema = db->aDb[i].pSchema;

  95660.           break;

  95661.         }

  95662.       }

  95663.     }

  95664.   }

  95665. 

  95666.   /* Start at the inner-most context and move outward until a match is found */

  95667.   assert( pNC && cnt==0 );

  95668.   do{

  95669.     ExprList *pEList;

  95670.     SrcList *pSrcList = pNC->pSrcList;

  95671. 

  95672.     if( pSrcList ){

  95673.       for(i=0, pItem=pSrcList->a; i<pSrcList->nSrc; i++, pItem++){

  95674.         pTab = pItem->pTab;

  95675.         assert( pTab!=0 && pTab->zName!=0 );

  95676.         assert( pTab->nCol>0 );

  95677.         if( pItem->pSelect && (pItem->pSelect->selFlags & SF_NestedFrom)!=0 ){

  95678.           int hit = 0;

  95679.           pEList = pItem->pSelect->pEList;

  95680.           for(j=0; j<pEList->nExpr; j++){

  95681.             if( sqlite3MatchSpanName(pEList->a[j].zSpan, zCol, zTab, zDb) ){

  95682.               cnt++;

  95683.               cntTab = 2;

  95684.               pMatch = pItem;

  95685.               pExpr->iColumn = j;

  95686.               hit = 1;

  95687.             }

  95688.           }

  95689.           if( hit || zTab==0 ) continue;

  95690.         }

  95691.         if( zDb && pTab->pSchema!=pSchema ){

  95692.           continue;

  95693.         }

  95694.         if( zTab ){

  95695.           const char *zTabName = pItem->zAlias ? pItem->zAlias : pTab->zName;

  95696.           assert( zTabName!=0 );

  95697.           if( sqlite3StrICmp(zTabName, zTab)!=0 ){

  95698.             continue;

  95699.           }

  95700.           if( IN_RENAME_OBJECT && pItem->zAlias ){

  95701.             sqlite3RenameTokenRemap(pParse, 0, (void*)&pExpr->y.pTab);

  95702.           }

  95703.         }

  95704.         if( 0==(cntTab++) ){

  95705.           pMatch = pItem;

  95706.         }

  95707.         for(j=0, pCol=pTab->aCol; j<pTab->nCol; j++, pCol++){

  95708.           if( sqlite3StrICmp(pCol->zName, zCol)==0 ){

  95709.             /* If there has been exactly one prior match and this match

  95710.             ** is for the right-hand table of a NATURAL JOIN or is in a 

  95711.             ** USING clause, then skip this match.

  95712.             */

  95713.             if( cnt==1 ){

  95714.               if( pItem->fg.jointype & JT_NATURAL ) continue;

  95715.               if( nameInUsingClause(pItem->pUsing, zCol) ) continue;

  95716.             }

  95717.             cnt++;

  95718.             pMatch = pItem;

  95719.             /* Substitute the rowid (column -1) for the INTEGER PRIMARY KEY */

  95720.             pExpr->iColumn = j==pTab->iPKey ? -1 : (i16)j;

  95721.             break;

  95722.           }

  95723.         }

  95724.       }

  95725.       if( pMatch ){

  95726.         pExpr->iTable = pMatch->iCursor;

  95727.         pExpr->y.pTab = pMatch->pTab;

  95728.         /* RIGHT JOIN not (yet) supported */

  95729.         assert( (pMatch->fg.jointype & JT_RIGHT)==0 );

  95730.         if( (pMatch->fg.jointype & JT_LEFT)!=0 ){

  95731.           ExprSetProperty(pExpr, EP_CanBeNull);

  95732.         }

  95733.         pSchema = pExpr->y.pTab->pSchema;

  95734.       }

  95735.     } /* if( pSrcList ) */

  95736. 

  95737. #if !defined(SQLITE_OMIT_TRIGGER) || !defined(SQLITE_OMIT_UPSERT)

  95738.     /* If we have not already resolved the name, then maybe 

  95739.     ** it is a new.* or old.* trigger argument reference.  Or

  95740.     ** maybe it is an excluded.* from an upsert.

  95741.     */

  95742.     if( zDb==0 && zTab!=0 && cntTab==0 ){

  95743.       pTab = 0;

  95744. #ifndef SQLITE_OMIT_TRIGGER

  95745.       if( pParse->pTriggerTab!=0 ){

  95746.         int op = pParse->eTriggerOp;

  95747.         assert( op==TK_DELETE || op==TK_UPDATE || op==TK_INSERT );

  95748.         if( op!=TK_DELETE && sqlite3StrICmp("new",zTab) == 0 ){

  95749.           pExpr->iTable = 1;

  95750.           pTab = pParse->pTriggerTab;

  95751.         }else if( op!=TK_INSERT && sqlite3StrICmp("old",zTab)==0 ){

  95752.           pExpr->iTable = 0;

  95753.           pTab = pParse->pTriggerTab;

  95754.         }

  95755.       }

  95756. #endif /* SQLITE_OMIT_TRIGGER */

  95757. #ifndef SQLITE_OMIT_UPSERT

  95758.       if( (pNC->ncFlags & NC_UUpsert)!=0 ){

  95759.         Upsert *pUpsert = pNC->uNC.pUpsert;

  95760.         if( pUpsert && sqlite3StrICmp("excluded",zTab)==0 ){

  95761.           pTab = pUpsert->pUpsertSrc->a[0].pTab;

  95762.           pExpr->iTable = 2;

  95763.         }

  95764.       }

  95765. #endif /* SQLITE_OMIT_UPSERT */

  95766. 

  95767.       if( pTab ){ 

  95768.         int iCol;

  95769.         pSchema = pTab->pSchema;

  95770.         cntTab++;

  95771.         for(iCol=0, pCol=pTab->aCol; iCol<pTab->nCol; iCol++, pCol++){

  95772.           if( sqlite3StrICmp(pCol->zName, zCol)==0 ){

  95773.             if( iCol==pTab->iPKey ){

  95774.               iCol = -1;

  95775.             }

  95776.             break;

  95777.           }

  95778.         }

  95779.         if( iCol>=pTab->nCol && sqlite3IsRowid(zCol) && VisibleRowid(pTab) ){

  95780.           /* IMP: R-51414-32910 */

  95781.           iCol = -1;

  95782.         }

  95783.         if( iCol<pTab->nCol ){

  95784.           cnt++;

  95785. #ifndef SQLITE_OMIT_UPSERT

  95786.           if( pExpr->iTable==2 ){

  95787.             testcase( iCol==(-1) );

  95788.             if( IN_RENAME_OBJECT ){

  95789.               pExpr->iColumn = iCol;

  95790.               pExpr->y.pTab = pTab;

  95791.               eNewExprOp = TK_COLUMN;

  95792.             }else{

  95793.               pExpr->iTable = pNC->uNC.pUpsert->regData + iCol;

  95794.               eNewExprOp = TK_REGISTER;

  95795.               ExprSetProperty(pExpr, EP_Alias);

  95796.             }

  95797.           }else

  95798. #endif /* SQLITE_OMIT_UPSERT */

  95799.           {

  95800. #ifndef SQLITE_OMIT_TRIGGER

  95801.             if( iCol<0 ){

  95802.               pExpr->affinity = SQLITE_AFF_INTEGER;

  95803.             }else if( pExpr->iTable==0 ){

  95804.               testcase( iCol==31 );

  95805.               testcase( iCol==32 );

  95806.               pParse->oldmask |= (iCol>=32 ? 0xffffffff : (((u32)1)<<iCol));

  95807.             }else{

  95808.               testcase( iCol==31 );

  95809.               testcase( iCol==32 );

  95810.               pParse->newmask |= (iCol>=32 ? 0xffffffff : (((u32)1)<<iCol));

  95811.             }

  95812.             pExpr->y.pTab = pTab;

  95813.             pExpr->iColumn = (i16)iCol;

  95814.             eNewExprOp = TK_TRIGGER;

  95815. #endif /* SQLITE_OMIT_TRIGGER */

  95816.           }

  95817.         }

  95818.       }

  95819.     }

  95820. #endif /* !defined(SQLITE_OMIT_TRIGGER) || !defined(SQLITE_OMIT_UPSERT) */

  95821. 

  95822.     /*

  95823.     ** Perhaps the name is a reference to the ROWID

  95824.     */

  95825.     if( cnt==0

  95826.      && cntTab==1

  95827.      && pMatch

  95828.      && (pNC->ncFlags & NC_IdxExpr)==0

  95829.      && sqlite3IsRowid(zCol)

  95830.      && VisibleRowid(pMatch->pTab)

  95831.     ){

  95832.       cnt = 1;

  95833.       pExpr->iColumn = -1;

  95834.       pExpr->affinity = SQLITE_AFF_INTEGER;

  95835.     }

  95836. 

  95837.     /*

  95838.     ** If the input is of the form Z (not Y.Z or X.Y.Z) then the name Z

  95839.     ** might refer to an result-set alias.  This happens, for example, when

  95840.     ** we are resolving names in the WHERE clause of the following command:

  95841.     **

  95842.     **     SELECT a+b AS x FROM table WHERE x<10;

  95843.     **

  95844.     ** In cases like this, replace pExpr with a copy of the expression that

  95845.     ** forms the result set entry ("a+b" in the example) and return immediately.

  95846.     ** Note that the expression in the result set should have already been

  95847.     ** resolved by the time the WHERE clause is resolved.

  95848.     **

  95849.     ** The ability to use an output result-set column in the WHERE, GROUP BY,

  95850.     ** or HAVING clauses, or as part of a larger expression in the ORDER BY

  95851.     ** clause is not standard SQL.  This is a (goofy) SQLite extension, that

  95852.     ** is supported for backwards compatibility only. Hence, we issue a warning

  95853.     ** on sqlite3_log() whenever the capability is used.

  95854.     */

  95855.     if( (pNC->ncFlags & NC_UEList)!=0

  95856.      && cnt==0

  95857.      && zTab==0

  95858.     ){

  95859.       pEList = pNC->uNC.pEList;

  95860.       assert( pEList!=0 );

  95861.       for(j=0; j<pEList->nExpr; j++){

  95862.         char *zAs = pEList->a[j].zName;

  95863.         if( zAs!=0 && sqlite3StrICmp(zAs, zCol)==0 ){

  95864.           Expr *pOrig;

  95865.           assert( pExpr->pLeft==0 && pExpr->pRight==0 );

  95866.           assert( pExpr->x.pList==0 );

  95867.           assert( pExpr->x.pSelect==0 );

  95868.           pOrig = pEList->a[j].pExpr;

  95869.           if( (pNC->ncFlags&NC_AllowAgg)==0 && ExprHasProperty(pOrig, EP_Agg) ){

  95870.             sqlite3ErrorMsg(pParse, "misuse of aliased aggregate %s", zAs);

  95871.             return WRC_Abort;

  95872.           }

  95873.           if( (pNC->ncFlags&NC_AllowWin)==0 && ExprHasProperty(pOrig, EP_Win) ){

  95874.             sqlite3ErrorMsg(pParse, "misuse of aliased window function %s",zAs);

  95875.             return WRC_Abort;

  95876.           }

  95877.           if( sqlite3ExprVectorSize(pOrig)!=1 ){

  95878.             sqlite3ErrorMsg(pParse, "row value misused");

  95879.             return WRC_Abort;

  95880.           }

  95881.           resolveAlias(pParse, pEList, j, pExpr, "", nSubquery);

  95882.           cnt = 1;

  95883.           pMatch = 0;

  95884.           assert( zTab==0 && zDb==0 );

  95885.           if( IN_RENAME_OBJECT ){

  95886.             sqlite3RenameTokenRemap(pParse, 0, (void*)pExpr);

  95887.           }

  95888.           goto lookupname_end;

  95889.         }

  95890.       } 

  95891.     }

  95892. 

  95893.     /* Advance to the next name context.  The loop will exit when either

  95894.     ** we have a match (cnt>0) or when we run out of name contexts.

  95895.     */

  95896.     if( cnt ) break;

  95897.     pNC = pNC->pNext;

  95898.     nSubquery++;

  95899.   }while( pNC );

  95900. 

  95901. 

  95902.   /*

  95903.   ** If X and Y are NULL (in other words if only the column name Z is

  95904.   ** supplied) and the value of Z is enclosed in double-quotes, then

  95905.   ** Z is a string literal if it doesn't match any column names.  In that

  95906.   ** case, we need to return right away and not make any changes to

  95907.   ** pExpr.

  95908.   **

  95909.   ** Because no reference was made to outer contexts, the pNC->nRef

  95910.   ** fields are not changed in any context.

  95911.   */

  95912.   if( cnt==0 && zTab==0 ){

  95913.     assert( pExpr->op==TK_ID );

  95914.     if( ExprHasProperty(pExpr,EP_DblQuoted)

  95915.      && areDoubleQuotedStringsEnabled(db, pTopNC)

  95916.     ){

  95917.       /* If a double-quoted identifier does not match any known column name,

  95918.       ** then treat it as a string.

  95919.       **

  95920.       ** This hack was added in the early days of SQLite in a misguided attempt

  95921.       ** to be compatible with MySQL 3.x, which used double-quotes for strings.

  95922.       ** I now sorely regret putting in this hack. The effect of this hack is

  95923.       ** that misspelled identifier names are silently converted into strings

  95924.       ** rather than causing an error, to the frustration of countless

  95925.       ** programmers. To all those frustrated programmers, my apologies.

  95926.       **

  95927.       ** Someday, I hope to get rid of this hack. Unfortunately there is

  95928.       ** a huge amount of legacy SQL that uses it. So for now, we just

  95929.       ** issue a warning.

  95930.       */

  95931.       sqlite3_log(SQLITE_WARNING,

  95932.         "double-quoted string literal: \"%w\"", zCol);

  95933. #ifdef SQLITE_ENABLE_NORMALIZE

  95934.       sqlite3VdbeAddDblquoteStr(db, pParse->pVdbe, zCol);

  95935. #endif

  95936.       pExpr->op = TK_STRING;

  95937.       pExpr->y.pTab = 0;

  95938.       return WRC_Prune;

  95939.     }

  95940.     if( sqlite3ExprIdToTrueFalse(pExpr) ){

  95941.       return WRC_Prune;

  95942.     }

  95943.   }

  95944. 

  95945.   /*

  95946.   ** cnt==0 means there was not match.  cnt>1 means there were two or

  95947.   ** more matches.  Either way, we have an error.

  95948.   */

  95949.   if( cnt!=1 ){

  95950.     const char *zErr;

  95951.     zErr = cnt==0 ? "no such column" : "ambiguous column name";

  95952.     if( zDb ){

  95953.       sqlite3ErrorMsg(pParse, "%s: %s.%s.%s", zErr, zDb, zTab, zCol);

  95954.     }else if( zTab ){

  95955.       sqlite3ErrorMsg(pParse, "%s: %s.%s", zErr, zTab, zCol);

  95956.     }else{

  95957.       sqlite3ErrorMsg(pParse, "%s: %s", zErr, zCol);

  95958.     }

  95959.     pParse->checkSchema = 1;

  95960.     pTopNC->nErr++;

  95961.   }

  95962. 

  95963.   /* If a column from a table in pSrcList is referenced, then record

  95964.   ** this fact in the pSrcList.a[].colUsed bitmask.  Column 0 causes

  95965.   ** bit 0 to be set.  Column 1 sets bit 1.  And so forth.  If the

  95966.   ** column number is greater than the number of bits in the bitmask

  95967.   ** then set the high-order bit of the bitmask.

  95968.   */

  95969.   if( pExpr->iColumn>=0 && pMatch!=0 ){

  95970.     int n = pExpr->iColumn;

  95971.     testcase( n==BMS-1 );

  95972.     if( n>=BMS ){

  95973.       n = BMS-1;

  95974.     }

  95975.     assert( pMatch->iCursor==pExpr->iTable );

  95976.     pMatch->colUsed |= ((Bitmask)1)<<n;

  95977.   }

  95978. 

  95979.   /* Clean up and return

  95980.   */

  95981.   sqlite3ExprDelete(db, pExpr->pLeft);

  95982.   pExpr->pLeft = 0;

  95983.   sqlite3ExprDelete(db, pExpr->pRight);

  95984.   pExpr->pRight = 0;

  95985.   pExpr->op = eNewExprOp;

  95986.   ExprSetProperty(pExpr, EP_Leaf);

  95987. lookupname_end:

  95988.   if( cnt==1 ){

  95989.     assert( pNC!=0 );

  95990.     if( !ExprHasProperty(pExpr, EP_Alias) ){

  95991.       sqlite3AuthRead(pParse, pExpr, pSchema, pNC->pSrcList);

  95992.     }

  95993.     /* Increment the nRef value on all name contexts from TopNC up to

  95994.     ** the point where the name matched. */

  95995.     for(;;){

  95996.       assert( pTopNC!=0 );

  95997.       pTopNC->nRef++;

  95998.       if( pTopNC==pNC ) break;

  95999.       pTopNC = pTopNC->pNext;

  96000.     }

  96001.     return WRC_Prune;

  96002.   } else {

  96003.     return WRC_Abort;

  96004.   }

  96005. }

  96006. 

  96007. /*

  96008. ** Allocate and return a pointer to an expression to load the column iCol

  96009. ** from datasource iSrc in SrcList pSrc.

  96010. */

  96011. SQLITE_PRIVATE Expr *sqlite3CreateColumnExpr(sqlite3 *db, SrcList *pSrc, int iSrc, int iCol){

  96012.   Expr *p = sqlite3ExprAlloc(db, TK_COLUMN, 0, 0);

  96013.   if( p ){

  96014.     struct SrcList_item *pItem = &pSrc->a[iSrc];

  96015.     p->y.pTab = pItem->pTab;

  96016.     p->iTable = pItem->iCursor;

  96017.     if( p->y.pTab->iPKey==iCol ){

  96018.       p->iColumn = -1;

  96019.     }else{

  96020.       p->iColumn = (ynVar)iCol;

  96021.       testcase( iCol==BMS );

  96022.       testcase( iCol==BMS-1 );

  96023.       pItem->colUsed |= ((Bitmask)1)<<(iCol>=BMS ? BMS-1 : iCol);

  96024.     }

  96025.   }

  96026.   return p;

  96027. }

  96028. 

  96029. /*

  96030. ** Report an error that an expression is not valid for some set of

  96031. ** pNC->ncFlags values determined by validMask.

  96032. */

  96033. static void notValid(

  96034.   Parse *pParse,       /* Leave error message here */

  96035.   NameContext *pNC,    /* The name context */

  96036.   const char *zMsg,    /* Type of error */

  96037.   int validMask        /* Set of contexts for which prohibited */

  96038. ){

  96039.   assert( (validMask&~(NC_IsCheck|NC_PartIdx|NC_IdxExpr))==0 );

  96040.   if( (pNC->ncFlags & validMask)!=0 ){

  96041.     const char *zIn = "partial index WHERE clauses";

  96042.     if( pNC->ncFlags & NC_IdxExpr )      zIn = "index expressions";

  96043. #ifndef SQLITE_OMIT_CHECK

  96044.     else if( pNC->ncFlags & NC_IsCheck ) zIn = "CHECK constraints";

  96045. #endif

  96046.     sqlite3ErrorMsg(pParse, "%s prohibited in %s", zMsg, zIn);

  96047.   }

  96048. }

  96049. 

  96050. /*

  96051. ** Expression p should encode a floating point value between 1.0 and 0.0.

  96052. ** Return 1024 times this value.  Or return -1 if p is not a floating point

  96053. ** value between 1.0 and 0.0.

  96054. */

  96055. static int exprProbability(Expr *p){

  96056.   double r = -1.0;

  96057.   if( p->op!=TK_FLOAT ) return -1;

  96058.   sqlite3AtoF(p->u.zToken, &r, sqlite3Strlen30(p->u.zToken), SQLITE_UTF8);

  96059.   assert( r>=0.0 );

  96060.   if( r>1.0 ) return -1;

  96061.   return (int)(r*134217728.0);

  96062. }

  96063. 

  96064. /*

  96065. ** This routine is callback for sqlite3WalkExpr().

  96066. **

  96067. ** Resolve symbolic names into TK_COLUMN operators for the current

  96068. ** node in the expression tree.  Return 0 to continue the search down

  96069. ** the tree or 2 to abort the tree walk.

  96070. **

  96071. ** This routine also does error checking and name resolution for

  96072. ** function names.  The operator for aggregate functions is changed

  96073. ** to TK_AGG_FUNCTION.

  96074. */

  96075. static int resolveExprStep(Walker *pWalker, Expr *pExpr){

  96076.   NameContext *pNC;

  96077.   Parse *pParse;

  96078. 

  96079.   pNC = pWalker->u.pNC;

  96080.   assert( pNC!=0 );

  96081.   pParse = pNC->pParse;

  96082.   assert( pParse==pWalker->pParse );

  96083. 

  96084. #ifndef NDEBUG

  96085.   if( pNC->pSrcList && pNC->pSrcList->nAlloc>0 ){

  96086.     SrcList *pSrcList = pNC->pSrcList;

  96087.     int i;

  96088.     for(i=0; i<pNC->pSrcList->nSrc; i++){

  96089.       assert( pSrcList->a[i].iCursor>=0 && pSrcList->a[i].iCursor<pParse->nTab);

  96090.     }

  96091.   }

  96092. #endif

  96093.   switch( pExpr->op ){

  96094. 

  96095. #if defined(SQLITE_ENABLE_UPDATE_DELETE_LIMIT) && !defined(SQLITE_OMIT_SUBQUERY)

  96096.     /* The special operator TK_ROW means use the rowid for the first

  96097.     ** column in the FROM clause.  This is used by the LIMIT and ORDER BY

  96098.     ** clause processing on UPDATE and DELETE statements.

  96099.     */

  96100.     case TK_ROW: {

  96101.       SrcList *pSrcList = pNC->pSrcList;

  96102.       struct SrcList_item *pItem;

  96103.       assert( pSrcList && pSrcList->nSrc==1 );

  96104.       pItem = pSrcList->a;

  96105.       assert( HasRowid(pItem->pTab) && pItem->pTab->pSelect==0 );

  96106.       pExpr->op = TK_COLUMN;

  96107.       pExpr->y.pTab = pItem->pTab;

  96108.       pExpr->iTable = pItem->iCursor;

  96109.       pExpr->iColumn = -1;

  96110.       pExpr->affinity = SQLITE_AFF_INTEGER;

  96111.       break;

  96112.     }

  96113. #endif /* defined(SQLITE_ENABLE_UPDATE_DELETE_LIMIT)

  96114.           && !defined(SQLITE_OMIT_SUBQUERY) */

  96115. 

  96116.     /* A column name:                    ID

  96117.     ** Or table name and column name:    ID.ID

  96118.     ** Or a database, table and column:  ID.ID.ID

  96119.     **

  96120.     ** The TK_ID and TK_OUT cases are combined so that there will only

  96121.     ** be one call to lookupName().  Then the compiler will in-line 

  96122.     ** lookupName() for a size reduction and performance increase.

  96123.     */

  96124.     case TK_ID:

  96125.     case TK_DOT: {

  96126.       const char *zColumn;

  96127.       const char *zTable;

  96128.       const char *zDb;

  96129.       Expr *pRight;

  96130. 

  96131.       if( pExpr->op==TK_ID ){

  96132.         zDb = 0;

  96133.         zTable = 0;

  96134.         zColumn = pExpr->u.zToken;

  96135.       }else{

  96136.         Expr *pLeft = pExpr->pLeft;

  96137.         notValid(pParse, pNC, "the \".\" operator", NC_IdxExpr);

  96138.         pRight = pExpr->pRight;

  96139.         if( pRight->op==TK_ID ){

  96140.           zDb = 0;

  96141.         }else{

  96142.           assert( pRight->op==TK_DOT );

  96143.           zDb = pLeft->u.zToken;

  96144.           pLeft = pRight->pLeft;

  96145.           pRight = pRight->pRight;

  96146.         }

  96147.         zTable = pLeft->u.zToken;

  96148.         zColumn = pRight->u.zToken;

  96149.         if( IN_RENAME_OBJECT ){

  96150.           sqlite3RenameTokenRemap(pParse, (void*)pExpr, (void*)pRight);

  96151.           sqlite3RenameTokenRemap(pParse, (void*)&pExpr->y.pTab, (void*)pLeft);

  96152.         }

  96153.       }

  96154.       return lookupName(pParse, zDb, zTable, zColumn, pNC, pExpr);

  96155.     }

  96156. 

  96157.     /* Resolve function names

  96158.     */

  96159.     case TK_FUNCTION: {

  96160.       ExprList *pList = pExpr->x.pList;    /* The argument list */

  96161.       int n = pList ? pList->nExpr : 0;    /* Number of arguments */

  96162.       int no_such_func = 0;       /* True if no such function exists */

  96163.       int wrong_num_args = 0;     /* True if wrong number of arguments */

  96164.       int is_agg = 0;             /* True if is an aggregate function */

  96165.       int nId;                    /* Number of characters in function name */

  96166.       const char *zId;            /* The function name. */

  96167.       FuncDef *pDef;              /* Information about the function */

  96168.       u8 enc = ENC(pParse->db);   /* The database encoding */

  96169.       int savedAllowFlags = (pNC->ncFlags & (NC_AllowAgg | NC_AllowWin));

  96170. 

  96171.       assert( !ExprHasProperty(pExpr, EP_xIsSelect) );

  96172.       zId = pExpr->u.zToken;

  96173.       nId = sqlite3Strlen30(zId);

  96174.       pDef = sqlite3FindFunction(pParse->db, zId, n, enc, 0);

  96175.       if( pDef==0 ){

  96176.         pDef = sqlite3FindFunction(pParse->db, zId, -2, enc, 0);

  96177.         if( pDef==0 ){

  96178.           no_such_func = 1;

  96179.         }else{

  96180.           wrong_num_args = 1;

  96181.         }

  96182.       }else{

  96183.         is_agg = pDef->xFinalize!=0;

  96184.         if( pDef->funcFlags & SQLITE_FUNC_UNLIKELY ){

  96185.           ExprSetProperty(pExpr, EP_Unlikely);

  96186.           if( n==2 ){

  96187.             pExpr->iTable = exprProbability(pList->a[1].pExpr);

  96188.             if( pExpr->iTable<0 ){

  96189.               sqlite3ErrorMsg(pParse,

  96190.                 "second argument to likelihood() must be a "

  96191.                 "constant between 0.0 and 1.0");

  96192.               pNC->nErr++;

  96193.             }

  96194.           }else{

  96195.             /* EVIDENCE-OF: R-61304-29449 The unlikely(X) function is

  96196.             ** equivalent to likelihood(X, 0.0625).

  96197.             ** EVIDENCE-OF: R-01283-11636 The unlikely(X) function is

  96198.             ** short-hand for likelihood(X,0.0625).

  96199.             ** EVIDENCE-OF: R-36850-34127 The likely(X) function is short-hand

  96200.             ** for likelihood(X,0.9375).

  96201.             ** EVIDENCE-OF: R-53436-40973 The likely(X) function is equivalent

  96202.             ** to likelihood(X,0.9375). */

  96203.             /* TUNING: unlikely() probability is 0.0625.  likely() is 0.9375 */

  96204.             pExpr->iTable = pDef->zName[0]=='u' ? 8388608 : 125829120;

  96205.           }             

  96206.         }

  96207. #ifndef SQLITE_OMIT_AUTHORIZATION

  96208.         {

  96209.           int auth = sqlite3AuthCheck(pParse, SQLITE_FUNCTION, 0,pDef->zName,0);

  96210.           if( auth!=SQLITE_OK ){

  96211.             if( auth==SQLITE_DENY ){

  96212.               sqlite3ErrorMsg(pParse, "not authorized to use function: %s",

  96213.                                       pDef->zName);

  96214.               pNC->nErr++;

  96215.             }

  96216.             pExpr->op = TK_NULL;

  96217.             return WRC_Prune;

  96218.           }

  96219.         }

  96220. #endif

  96221.         if( pDef->funcFlags & (SQLITE_FUNC_CONSTANT|SQLITE_FUNC_SLOCHNG) ){

  96222.           /* For the purposes of the EP_ConstFunc flag, date and time

  96223.           ** functions and other functions that change slowly are considered

  96224.           ** constant because they are constant for the duration of one query */

  96225.           ExprSetProperty(pExpr,EP_ConstFunc);

  96226.         }

  96227.         if( (pDef->funcFlags & SQLITE_FUNC_CONSTANT)==0 ){

  96228.           /* Date/time functions that use 'now', and other functions like

  96229.           ** sqlite_version() that might change over time cannot be used

  96230.           ** in an index. */

  96231.           notValid(pParse, pNC, "non-deterministic functions",

  96232.                    NC_IdxExpr|NC_PartIdx);

  96233.         }

  96234.         if( (pDef->funcFlags & SQLITE_FUNC_INTERNAL)!=0

  96235.          && pParse->nested==0

  96236.          && sqlite3Config.bInternalFunctions==0

  96237.         ){

  96238.           /* Internal-use-only functions are disallowed unless the

  96239.           ** SQL is being compiled using sqlite3NestedParse() */

  96240.           no_such_func = 1;

  96241.           pDef = 0;

  96242.         }

  96243.       }

  96244. 

  96245.       if( 0==IN_RENAME_OBJECT ){

  96246. #ifndef SQLITE_OMIT_WINDOWFUNC

  96247.         assert( is_agg==0 || (pDef->funcFlags & SQLITE_FUNC_MINMAX)

  96248.           || (pDef->xValue==0 && pDef->xInverse==0)

  96249.           || (pDef->xValue && pDef->xInverse && pDef->xSFunc && pDef->xFinalize)

  96250.         );

  96251.         if( pDef && pDef->xValue==0 && ExprHasProperty(pExpr, EP_WinFunc) ){

  96252.           sqlite3ErrorMsg(pParse, 

  96253.               "%.*s() may not be used as a window function", nId, zId

  96254.           );

  96255.           pNC->nErr++;

  96256.         }else if( 

  96257.               (is_agg && (pNC->ncFlags & NC_AllowAgg)==0)

  96258.            || (is_agg && (pDef->funcFlags&SQLITE_FUNC_WINDOW) && !pExpr->y.pWin)

  96259.            || (is_agg && pExpr->y.pWin && (pNC->ncFlags & NC_AllowWin)==0)

  96260.         ){

  96261.           const char *zType;

  96262.           if( (pDef->funcFlags & SQLITE_FUNC_WINDOW) || pExpr->y.pWin ){

  96263.             zType = "window";

  96264.           }else{

  96265.             zType = "aggregate";

  96266.           }

  96267.           sqlite3ErrorMsg(pParse, "misuse of %s function %.*s()",zType,nId,zId);

  96268.           pNC->nErr++;

  96269.           is_agg = 0;

  96270.         }

  96271. #else

  96272.         if( (is_agg && (pNC->ncFlags & NC_AllowAgg)==0) ){

  96273.           sqlite3ErrorMsg(pParse,"misuse of aggregate function %.*s()",nId,zId);

  96274.           pNC->nErr++;

  96275.           is_agg = 0;

  96276.         }

  96277. #endif

  96278.         else if( no_such_func && pParse->db->init.busy==0

  96279. #ifdef SQLITE_ENABLE_UNKNOWN_SQL_FUNCTION

  96280.                   && pParse->explain==0

  96281. #endif

  96282.         ){

  96283.           sqlite3ErrorMsg(pParse, "no such function: %.*s", nId, zId);

  96284.           pNC->nErr++;

  96285.         }else if( wrong_num_args ){

  96286.           sqlite3ErrorMsg(pParse,"wrong number of arguments to function %.*s()",

  96287.                nId, zId);

  96288.           pNC->nErr++;

  96289.         }

  96290.         if( is_agg ){

  96291.           /* Window functions may not be arguments of aggregate functions.

  96292.           ** Or arguments of other window functions. But aggregate functions

  96293.           ** may be arguments for window functions.  */

  96294. #ifndef SQLITE_OMIT_WINDOWFUNC

  96295.           pNC->ncFlags &= ~(NC_AllowWin | (!pExpr->y.pWin ? NC_AllowAgg : 0));

  96296. #else

  96297.           pNC->ncFlags &= ~NC_AllowAgg;

  96298. #endif

  96299.         }

  96300.       }

  96301.       sqlite3WalkExprList(pWalker, pList);

  96302.       if( is_agg ){

  96303. #ifndef SQLITE_OMIT_WINDOWFUNC

  96304.         if( pExpr->y.pWin ){

  96305.           Select *pSel = pNC->pWinSelect;

  96306.           if( IN_RENAME_OBJECT==0 ){

  96307.             sqlite3WindowUpdate(pParse, pSel->pWinDefn, pExpr->y.pWin, pDef);

  96308.           }

  96309.           sqlite3WalkExprList(pWalker, pExpr->y.pWin->pPartition);

  96310.           sqlite3WalkExprList(pWalker, pExpr->y.pWin->pOrderBy);

  96311.           sqlite3WalkExpr(pWalker, pExpr->y.pWin->pFilter);

  96312.           if( 0==pSel->pWin 

  96313.            || 0==sqlite3WindowCompare(pParse, pSel->pWin, pExpr->y.pWin) 

  96314.           ){

  96315.             pExpr->y.pWin->pNextWin = pSel->pWin;

  96316.             pSel->pWin = pExpr->y.pWin;

  96317.           }

  96318.           pNC->ncFlags |= NC_HasWin;

  96319.         }else

  96320. #endif /* SQLITE_OMIT_WINDOWFUNC */

  96321.         {

  96322.           NameContext *pNC2 = pNC;

  96323.           pExpr->op = TK_AGG_FUNCTION;

  96324.           pExpr->op2 = 0;

  96325.           while( pNC2 && !sqlite3FunctionUsesThisSrc(pExpr, pNC2->pSrcList) ){

  96326.             pExpr->op2++;

  96327.             pNC2 = pNC2->pNext;

  96328.           }

  96329.           assert( pDef!=0 );

  96330.           if( pNC2 ){

  96331.             assert( SQLITE_FUNC_MINMAX==NC_MinMaxAgg );

  96332.             testcase( (pDef->funcFlags & SQLITE_FUNC_MINMAX)!=0 );

  96333.             pNC2->ncFlags |= NC_HasAgg | (pDef->funcFlags & SQLITE_FUNC_MINMAX);

  96334. 

  96335.           }

  96336.         }

  96337.         pNC->ncFlags |= savedAllowFlags;

  96338.       }

  96339.       /* FIX ME:  Compute pExpr->affinity based on the expected return

  96340.       ** type of the function 

  96341.       */

  96342.       return WRC_Prune;

  96343.     }

  96344. #ifndef SQLITE_OMIT_SUBQUERY

  96345.     case TK_SELECT:

  96346.     case TK_EXISTS:  testcase( pExpr->op==TK_EXISTS );

  96347. #endif

  96348.     case TK_IN: {

  96349.       testcase( pExpr->op==TK_IN );

  96350.       if( ExprHasProperty(pExpr, EP_xIsSelect) ){

  96351.         int nRef = pNC->nRef;

  96352.         notValid(pParse, pNC, "subqueries", NC_IsCheck|NC_PartIdx|NC_IdxExpr);

  96353.         sqlite3WalkSelect(pWalker, pExpr->x.pSelect);

  96354.         assert( pNC->nRef>=nRef );

  96355.         if( nRef!=pNC->nRef ){

  96356.           ExprSetProperty(pExpr, EP_VarSelect);

  96357.           pNC->ncFlags |= NC_VarSelect;

  96358.         }

  96359.       }

  96360.       break;

  96361.     }

  96362.     case TK_VARIABLE: {

  96363.       notValid(pParse, pNC, "parameters", NC_IsCheck|NC_PartIdx|NC_IdxExpr);

  96364.       break;

  96365.     }

  96366.     case TK_IS:

  96367.     case TK_ISNOT: {

  96368.       Expr *pRight = sqlite3ExprSkipCollate(pExpr->pRight);

  96369.       assert( !ExprHasProperty(pExpr, EP_Reduced) );

  96370.       /* Handle special cases of "x IS TRUE", "x IS FALSE", "x IS NOT TRUE",

  96371.       ** and "x IS NOT FALSE". */

  96372.       if( pRight->op==TK_ID ){

  96373.         int rc = resolveExprStep(pWalker, pRight);

  96374.         if( rc==WRC_Abort ) return WRC_Abort;

  96375.         if( pRight->op==TK_TRUEFALSE ){

  96376.           pExpr->op2 = pExpr->op;

  96377.           pExpr->op = TK_TRUTH;

  96378.           return WRC_Continue;

  96379.         }

  96380.       }

  96381.       /* Fall thru */

  96382.     }

  96383.     case TK_BETWEEN:

  96384.     case TK_EQ:

  96385.     case TK_NE:

  96386.     case TK_LT:

  96387.     case TK_LE:

  96388.     case TK_GT:

  96389.     case TK_GE: {

  96390.       int nLeft, nRight;

  96391.       if( pParse->db->mallocFailed ) break;

  96392.       assert( pExpr->pLeft!=0 );

  96393.       nLeft = sqlite3ExprVectorSize(pExpr->pLeft);

  96394.       if( pExpr->op==TK_BETWEEN ){

  96395.         nRight = sqlite3ExprVectorSize(pExpr->x.pList->a[0].pExpr);

  96396.         if( nRight==nLeft ){

  96397.           nRight = sqlite3ExprVectorSize(pExpr->x.pList->a[1].pExpr);

  96398.         }

  96399.       }else{

  96400.         assert( pExpr->pRight!=0 );

  96401.         nRight = sqlite3ExprVectorSize(pExpr->pRight);

  96402.       }

  96403.       if( nLeft!=nRight ){

  96404.         testcase( pExpr->op==TK_EQ );

  96405.         testcase( pExpr->op==TK_NE );

  96406.         testcase( pExpr->op==TK_LT );

  96407.         testcase( pExpr->op==TK_LE );

  96408.         testcase( pExpr->op==TK_GT );

  96409.         testcase( pExpr->op==TK_GE );

  96410.         testcase( pExpr->op==TK_IS );

  96411.         testcase( pExpr->op==TK_ISNOT );

  96412.         testcase( pExpr->op==TK_BETWEEN );

  96413.         sqlite3ErrorMsg(pParse, "row value misused");

  96414.       }

  96415.       break; 

  96416.     }

  96417.   }

  96418.   return (pParse->nErr || pParse->db->mallocFailed) ? WRC_Abort : WRC_Continue;

  96419. }

  96420. 

  96421. /*

  96422. ** pEList is a list of expressions which are really the result set of the

  96423. ** a SELECT statement.  pE is a term in an ORDER BY or GROUP BY clause.

  96424. ** This routine checks to see if pE is a simple identifier which corresponds

  96425. ** to the AS-name of one of the terms of the expression list.  If it is,

  96426. ** this routine return an integer between 1 and N where N is the number of

  96427. ** elements in pEList, corresponding to the matching entry.  If there is

  96428. ** no match, or if pE is not a simple identifier, then this routine

  96429. ** return 0.

  96430. **

  96431. ** pEList has been resolved.  pE has not.

  96432. */

  96433. static int resolveAsName(

  96434.   Parse *pParse,     /* Parsing context for error messages */

  96435.   ExprList *pEList,  /* List of expressions to scan */

  96436.   Expr *pE           /* Expression we are trying to match */

  96437. ){

  96438.   int i;             /* Loop counter */

  96439. 

  96440.   UNUSED_PARAMETER(pParse);

  96441. 

  96442.   if( pE->op==TK_ID ){

  96443.     char *zCol = pE->u.zToken;

  96444.     for(i=0; i<pEList->nExpr; i++){

  96445.       char *zAs = pEList->a[i].zName;

  96446.       if( zAs!=0 && sqlite3StrICmp(zAs, zCol)==0 ){

  96447.         return i+1;

  96448.       }

  96449.     }

  96450.   }

  96451.   return 0;

  96452. }

  96453. 

  96454. /*

  96455. ** pE is a pointer to an expression which is a single term in the

  96456. ** ORDER BY of a compound SELECT.  The expression has not been

  96457. ** name resolved.

  96458. **

  96459. ** At the point this routine is called, we already know that the

  96460. ** ORDER BY term is not an integer index into the result set.  That

  96461. ** case is handled by the calling routine.

  96462. **

  96463. ** Attempt to match pE against result set columns in the left-most

  96464. ** SELECT statement.  Return the index i of the matching column,

  96465. ** as an indication to the caller that it should sort by the i-th column.

  96466. ** The left-most column is 1.  In other words, the value returned is the

  96467. ** same integer value that would be used in the SQL statement to indicate

  96468. ** the column.

  96469. **

  96470. ** If there is no match, return 0.  Return -1 if an error occurs.

  96471. */

  96472. static int resolveOrderByTermToExprList(

  96473.   Parse *pParse,     /* Parsing context for error messages */

  96474.   Select *pSelect,   /* The SELECT statement with the ORDER BY clause */

  96475.   Expr *pE           /* The specific ORDER BY term */

  96476. ){

  96477.   int i;             /* Loop counter */

  96478.   ExprList *pEList;  /* The columns of the result set */

  96479.   NameContext nc;    /* Name context for resolving pE */

  96480.   sqlite3 *db;       /* Database connection */

  96481.   int rc;            /* Return code from subprocedures */

  96482.   u8 savedSuppErr;   /* Saved value of db->suppressErr */

  96483. 

  96484.   assert( sqlite3ExprIsInteger(pE, &i)==0 );

  96485.   pEList = pSelect->pEList;

  96486. 

  96487.   /* Resolve all names in the ORDER BY term expression

  96488.   */

  96489.   memset(&nc, 0, sizeof(nc));

  96490.   nc.pParse = pParse;

  96491.   nc.pSrcList = pSelect->pSrc;

  96492.   nc.uNC.pEList = pEList;

  96493.   nc.ncFlags = NC_AllowAgg|NC_UEList;

  96494.   nc.nErr = 0;

  96495.   db = pParse->db;

  96496.   savedSuppErr = db->suppressErr;

  96497.   db->suppressErr = 1;

  96498.   rc = sqlite3ResolveExprNames(&nc, pE);

  96499.   db->suppressErr = savedSuppErr;

  96500.   if( rc ) return 0;

  96501. 

  96502.   /* Try to match the ORDER BY expression against an expression

  96503.   ** in the result set.  Return an 1-based index of the matching

  96504.   ** result-set entry.

  96505.   */

  96506.   for(i=0; i<pEList->nExpr; i++){

  96507.     if( sqlite3ExprCompare(0, pEList->a[i].pExpr, pE, -1)<2 ){

  96508.       return i+1;

  96509.     }

  96510.   }

  96511. 

  96512.   /* If no match, return 0. */

  96513.   return 0;

  96514. }

  96515. 

  96516. /*

  96517. ** Generate an ORDER BY or GROUP BY term out-of-range error.

  96518. */

  96519. static void resolveOutOfRangeError(

  96520.   Parse *pParse,         /* The error context into which to write the error */

  96521.   const char *zType,     /* "ORDER" or "GROUP" */

  96522.   int i,                 /* The index (1-based) of the term out of range */

  96523.   int mx                 /* Largest permissible value of i */

  96524. ){

  96525.   sqlite3ErrorMsg(pParse, 

  96526.     "%r %s BY term out of range - should be "

  96527.     "between 1 and %d", i, zType, mx);

  96528. }

  96529. 

  96530. /*

  96531. ** Analyze the ORDER BY clause in a compound SELECT statement.   Modify

  96532. ** each term of the ORDER BY clause is a constant integer between 1

  96533. ** and N where N is the number of columns in the compound SELECT.

  96534. **

  96535. ** ORDER BY terms that are already an integer between 1 and N are

  96536. ** unmodified.  ORDER BY terms that are integers outside the range of

  96537. ** 1 through N generate an error.  ORDER BY terms that are expressions

  96538. ** are matched against result set expressions of compound SELECT

  96539. ** beginning with the left-most SELECT and working toward the right.

  96540. ** At the first match, the ORDER BY expression is transformed into

  96541. ** the integer column number.

  96542. **

  96543. ** Return the number of errors seen.

  96544. */

  96545. static int resolveCompoundOrderBy(

  96546.   Parse *pParse,        /* Parsing context.  Leave error messages here */

  96547.   Select *pSelect       /* The SELECT statement containing the ORDER BY */

  96548. ){

  96549.   int i;

  96550.   ExprList *pOrderBy;

  96551.   ExprList *pEList;

  96552.   sqlite3 *db;

  96553.   int moreToDo = 1;

  96554. 

  96555.   pOrderBy = pSelect->pOrderBy;

  96556.   if( pOrderBy==0 ) return 0;

  96557.   db = pParse->db;

  96558.   if( pOrderBy->nExpr>db->aLimit[SQLITE_LIMIT_COLUMN] ){

  96559.     sqlite3ErrorMsg(pParse, "too many terms in ORDER BY clause");

  96560.     return 1;

  96561.   }

  96562.   for(i=0; i<pOrderBy->nExpr; i++){

  96563.     pOrderBy->a[i].done = 0;

  96564.   }

  96565.   pSelect->pNext = 0;

  96566.   while( pSelect->pPrior ){

  96567.     pSelect->pPrior->pNext = pSelect;

  96568.     pSelect = pSelect->pPrior;

  96569.   }

  96570.   while( pSelect && moreToDo ){

  96571.     struct ExprList_item *pItem;

  96572.     moreToDo = 0;

  96573.     pEList = pSelect->pEList;

  96574.     assert( pEList!=0 );

  96575.     for(i=0, pItem=pOrderBy->a; i<pOrderBy->nExpr; i++, pItem++){

  96576.       int iCol = -1;

  96577.       Expr *pE, *pDup;

  96578.       if( pItem->done ) continue;

  96579.       pE = sqlite3ExprSkipCollate(pItem->pExpr);

  96580.       if( sqlite3ExprIsInteger(pE, &iCol) ){

  96581.         if( iCol<=0 || iCol>pEList->nExpr ){

  96582.           resolveOutOfRangeError(pParse, "ORDER", i+1, pEList->nExpr);

  96583.           return 1;

  96584.         }

  96585.       }else{

  96586.         iCol = resolveAsName(pParse, pEList, pE);

  96587.         if( iCol==0 ){

  96588.           /* Now test if expression pE matches one of the values returned

  96589.           ** by pSelect. In the usual case this is done by duplicating the 

  96590.           ** expression, resolving any symbols in it, and then comparing

  96591.           ** it against each expression returned by the SELECT statement.

  96592.           ** Once the comparisons are finished, the duplicate expression

  96593.           ** is deleted.

  96594.           **

  96595.           ** Or, if this is running as part of an ALTER TABLE operation,

  96596.           ** resolve the symbols in the actual expression, not a duplicate.

  96597.           ** And, if one of the comparisons is successful, leave the expression

  96598.           ** as is instead of transforming it to an integer as in the usual

  96599.           ** case. This allows the code in alter.c to modify column

  96600.           ** refererences within the ORDER BY expression as required.  */

  96601.           if( IN_RENAME_OBJECT ){

  96602.             pDup = pE;

  96603.           }else{

  96604.             pDup = sqlite3ExprDup(db, pE, 0);

  96605.           }

  96606.           if( !db->mallocFailed ){

  96607.             assert(pDup);

  96608.             iCol = resolveOrderByTermToExprList(pParse, pSelect, pDup);

  96609.           }

  96610.           if( !IN_RENAME_OBJECT ){

  96611.             sqlite3ExprDelete(db, pDup);

  96612.           }

  96613.         }

  96614.       }

  96615.       if( iCol>0 ){

  96616.         /* Convert the ORDER BY term into an integer column number iCol,

  96617.         ** taking care to preserve the COLLATE clause if it exists */

  96618.         if( !IN_RENAME_OBJECT ){

  96619.           Expr *pNew = sqlite3Expr(db, TK_INTEGER, 0);

  96620.           if( pNew==0 ) return 1;

  96621.           pNew->flags |= EP_IntValue;

  96622.           pNew->u.iValue = iCol;

  96623.           if( pItem->pExpr==pE ){

  96624.             pItem->pExpr = pNew;

  96625.           }else{

  96626.             Expr *pParent = pItem->pExpr;

  96627.             assert( pParent->op==TK_COLLATE );

  96628.             while( pParent->pLeft->op==TK_COLLATE ) pParent = pParent->pLeft;

  96629.             assert( pParent->pLeft==pE );

  96630.             pParent->pLeft = pNew;

  96631.           }

  96632.           sqlite3ExprDelete(db, pE);

  96633.           pItem->u.x.iOrderByCol = (u16)iCol;

  96634.         }

  96635.         pItem->done = 1;

  96636.       }else{

  96637.         moreToDo = 1;

  96638.       }

  96639.     }

  96640.     pSelect = pSelect->pNext;

  96641.   }

  96642.   for(i=0; i<pOrderBy->nExpr; i++){

  96643.     if( pOrderBy->a[i].done==0 ){

  96644.       sqlite3ErrorMsg(pParse, "%r ORDER BY term does not match any "

  96645.             "column in the result set", i+1);

  96646.       return 1;

  96647.     }

  96648.   }

  96649.   return 0;

  96650. }

  96651. 

  96652. /*

  96653. ** Check every term in the ORDER BY or GROUP BY clause pOrderBy of

  96654. ** the SELECT statement pSelect.  If any term is reference to a

  96655. ** result set expression (as determined by the ExprList.a.u.x.iOrderByCol

  96656. ** field) then convert that term into a copy of the corresponding result set

  96657. ** column.

  96658. **

  96659. ** If any errors are detected, add an error message to pParse and

  96660. ** return non-zero.  Return zero if no errors are seen.

  96661. */

  96662. SQLITE_PRIVATE int sqlite3ResolveOrderGroupBy(

  96663.   Parse *pParse,        /* Parsing context.  Leave error messages here */

  96664.   Select *pSelect,      /* The SELECT statement containing the clause */

  96665.   ExprList *pOrderBy,   /* The ORDER BY or GROUP BY clause to be processed */

  96666.   const char *zType     /* "ORDER" or "GROUP" */

  96667. ){

  96668.   int i;

  96669.   sqlite3 *db = pParse->db;

  96670.   ExprList *pEList;

  96671.   struct ExprList_item *pItem;

  96672. 

  96673.   if( pOrderBy==0 || pParse->db->mallocFailed ) return 0;

  96674.   if( pOrderBy->nExpr>db->aLimit[SQLITE_LIMIT_COLUMN] ){

  96675.     sqlite3ErrorMsg(pParse, "too many terms in %s BY clause", zType);

  96676.     return 1;

  96677.   }

  96678.   pEList = pSelect->pEList;

  96679.   assert( pEList!=0 );  /* sqlite3SelectNew() guarantees this */

  96680.   for(i=0, pItem=pOrderBy->a; i<pOrderBy->nExpr; i++, pItem++){

  96681.     if( pItem->u.x.iOrderByCol ){

  96682.       if( pItem->u.x.iOrderByCol>pEList->nExpr ){

  96683.         resolveOutOfRangeError(pParse, zType, i+1, pEList->nExpr);

  96684.         return 1;

  96685.       }

  96686.       resolveAlias(pParse, pEList, pItem->u.x.iOrderByCol-1, pItem->pExpr,

  96687.                    zType,0);

  96688.     }

  96689.   }

  96690.   return 0;

  96691. }

  96692. 

  96693. #ifndef SQLITE_OMIT_WINDOWFUNC

  96694. /*

  96695. ** Walker callback for resolveRemoveWindows().

  96696. */

  96697. static int resolveRemoveWindowsCb(Walker *pWalker, Expr *pExpr){

  96698.   if( ExprHasProperty(pExpr, EP_WinFunc) ){

  96699.     Window **pp;

  96700.     for(pp=&pWalker->u.pSelect->pWin; *pp; pp=&(*pp)->pNextWin){

  96701.       if( *pp==pExpr->y.pWin ){

  96702.         *pp = (*pp)->pNextWin;

  96703.         break;

  96704.       }    

  96705.     }

  96706.   }

  96707.   return WRC_Continue;

  96708. }

  96709. 

  96710. /*

  96711. ** Remove any Window objects owned by the expression pExpr from the

  96712. ** Select.pWin list of Select object pSelect.

  96713. */

  96714. static void resolveRemoveWindows(Select *pSelect, Expr *pExpr){

  96715.   Walker sWalker;

  96716.   memset(&sWalker, 0, sizeof(Walker));

  96717.   sWalker.xExprCallback = resolveRemoveWindowsCb;

  96718.   sWalker.u.pSelect = pSelect;

  96719.   sqlite3WalkExpr(&sWalker, pExpr);

  96720. }

  96721. #else

  96722. # define resolveRemoveWindows(x,y)

  96723. #endif

  96724. 

  96725. /*

  96726. ** pOrderBy is an ORDER BY or GROUP BY clause in SELECT statement pSelect.

  96727. ** The Name context of the SELECT statement is pNC.  zType is either

  96728. ** "ORDER" or "GROUP" depending on which type of clause pOrderBy is.

  96729. **

  96730. ** This routine resolves each term of the clause into an expression.

  96731. ** If the order-by term is an integer I between 1 and N (where N is the

  96732. ** number of columns in the result set of the SELECT) then the expression

  96733. ** in the resolution is a copy of the I-th result-set expression.  If

  96734. ** the order-by term is an identifier that corresponds to the AS-name of

  96735. ** a result-set expression, then the term resolves to a copy of the

  96736. ** result-set expression.  Otherwise, the expression is resolved in

  96737. ** the usual way - using sqlite3ResolveExprNames().

  96738. **

  96739. ** This routine returns the number of errors.  If errors occur, then

  96740. ** an appropriate error message might be left in pParse.  (OOM errors

  96741. ** excepted.)

  96742. */

  96743. static int resolveOrderGroupBy(

  96744.   NameContext *pNC,     /* The name context of the SELECT statement */

  96745.   Select *pSelect,      /* The SELECT statement holding pOrderBy */

  96746.   ExprList *pOrderBy,   /* An ORDER BY or GROUP BY clause to resolve */

  96747.   const char *zType     /* Either "ORDER" or "GROUP", as appropriate */

  96748. ){

  96749.   int i, j;                      /* Loop counters */

  96750.   int iCol;                      /* Column number */

  96751.   struct ExprList_item *pItem;   /* A term of the ORDER BY clause */

  96752.   Parse *pParse;                 /* Parsing context */

  96753.   int nResult;                   /* Number of terms in the result set */

  96754. 

  96755.   if( pOrderBy==0 ) return 0;

  96756.   nResult = pSelect->pEList->nExpr;

  96757.   pParse = pNC->pParse;

  96758.   for(i=0, pItem=pOrderBy->a; i<pOrderBy->nExpr; i++, pItem++){

  96759.     Expr *pE = pItem->pExpr;

  96760.     Expr *pE2 = sqlite3ExprSkipCollate(pE);

  96761.     if( zType[0]!='G' ){

  96762.       iCol = resolveAsName(pParse, pSelect->pEList, pE2);

  96763.       if( iCol>0 ){

  96764.         /* If an AS-name match is found, mark this ORDER BY column as being

  96765.         ** a copy of the iCol-th result-set column.  The subsequent call to

  96766.         ** sqlite3ResolveOrderGroupBy() will convert the expression to a

  96767.         ** copy of the iCol-th result-set expression. */

  96768.         pItem->u.x.iOrderByCol = (u16)iCol;

  96769.         continue;

  96770.       }

  96771.     }

  96772.     if( sqlite3ExprIsInteger(pE2, &iCol) ){

  96773.       /* The ORDER BY term is an integer constant.  Again, set the column

  96774.       ** number so that sqlite3ResolveOrderGroupBy() will convert the

  96775.       ** order-by term to a copy of the result-set expression */

  96776.       if( iCol<1 || iCol>0xffff ){

  96777.         resolveOutOfRangeError(pParse, zType, i+1, nResult);

  96778.         return 1;

  96779.       }

  96780.       pItem->u.x.iOrderByCol = (u16)iCol;

  96781.       continue;

  96782.     }

  96783. 

  96784.     /* Otherwise, treat the ORDER BY term as an ordinary expression */

  96785.     pItem->u.x.iOrderByCol = 0;

  96786.     if( sqlite3ResolveExprNames(pNC, pE) ){

  96787.       return 1;

  96788.     }

  96789.     for(j=0; j<pSelect->pEList->nExpr; j++){

  96790.       if( sqlite3ExprCompare(0, pE, pSelect->pEList->a[j].pExpr, -1)==0 ){

  96791.         /* Since this expresion is being changed into a reference

  96792.         ** to an identical expression in the result set, remove all Window

  96793.         ** objects belonging to the expression from the Select.pWin list. */

  96794.         resolveRemoveWindows(pSelect, pE);

  96795.         pItem->u.x.iOrderByCol = j+1;

  96796.       }

  96797.     }

  96798.   }

  96799.   return sqlite3ResolveOrderGroupBy(pParse, pSelect, pOrderBy, zType);

  96800. }

  96801. 

  96802. /*

  96803. ** Resolve names in the SELECT statement p and all of its descendants.

  96804. */

  96805. static int resolveSelectStep(Walker *pWalker, Select *p){

  96806.   NameContext *pOuterNC;  /* Context that contains this SELECT */

  96807.   NameContext sNC;        /* Name context of this SELECT */

  96808.   int isCompound;         /* True if p is a compound select */

  96809.   int nCompound;          /* Number of compound terms processed so far */

  96810.   Parse *pParse;          /* Parsing context */

  96811.   int i;                  /* Loop counter */

  96812.   ExprList *pGroupBy;     /* The GROUP BY clause */

  96813.   Select *pLeftmost;      /* Left-most of SELECT of a compound */

  96814.   sqlite3 *db;            /* Database connection */

  96815.   

  96816. 

  96817.   assert( p!=0 );

  96818.   if( p->selFlags & SF_Resolved ){

  96819.     return WRC_Prune;

  96820.   }

  96821.   pOuterNC = pWalker->u.pNC;

  96822.   pParse = pWalker->pParse;

  96823.   db = pParse->db;

  96824. 

  96825.   /* Normally sqlite3SelectExpand() will be called first and will have

  96826.   ** already expanded this SELECT.  However, if this is a subquery within

  96827.   ** an expression, sqlite3ResolveExprNames() will be called without a

  96828.   ** prior call to sqlite3SelectExpand().  When that happens, let

  96829.   ** sqlite3SelectPrep() do all of the processing for this SELECT.

  96830.   ** sqlite3SelectPrep() will invoke both sqlite3SelectExpand() and

  96831.   ** this routine in the correct order.

  96832.   */

  96833.   if( (p->selFlags & SF_Expanded)==0 ){

  96834.     sqlite3SelectPrep(pParse, p, pOuterNC);

  96835.     return (pParse->nErr || db->mallocFailed) ? WRC_Abort : WRC_Prune;

  96836.   }

  96837. 

  96838.   isCompound = p->pPrior!=0;

  96839.   nCompound = 0;

  96840.   pLeftmost = p;

  96841.   while( p ){

  96842.     assert( (p->selFlags & SF_Expanded)!=0 );

  96843.     assert( (p->selFlags & SF_Resolved)==0 );

  96844.     p->selFlags |= SF_Resolved;

  96845. 

  96846.     /* Resolve the expressions in the LIMIT and OFFSET clauses. These

  96847.     ** are not allowed to refer to any names, so pass an empty NameContext.

  96848.     */

  96849.     memset(&sNC, 0, sizeof(sNC));

  96850.     sNC.pParse = pParse;

  96851.     sNC.pWinSelect = p;

  96852.     if( sqlite3ResolveExprNames(&sNC, p->pLimit) ){

  96853.       return WRC_Abort;

  96854.     }

  96855. 

  96856.     /* If the SF_Converted flags is set, then this Select object was

  96857.     ** was created by the convertCompoundSelectToSubquery() function.

  96858.     ** In this case the ORDER BY clause (p->pOrderBy) should be resolved

  96859.     ** as if it were part of the sub-query, not the parent. This block

  96860.     ** moves the pOrderBy down to the sub-query. It will be moved back

  96861.     ** after the names have been resolved.  */

  96862.     if( p->selFlags & SF_Converted ){

  96863.       Select *pSub = p->pSrc->a[0].pSelect;

  96864.       assert( p->pSrc->nSrc==1 && p->pOrderBy );

  96865.       assert( pSub->pPrior && pSub->pOrderBy==0 );

  96866.       pSub->pOrderBy = p->pOrderBy;

  96867.       p->pOrderBy = 0;

  96868.     }

  96869.   

  96870.     /* Recursively resolve names in all subqueries

  96871.     */

  96872.     for(i=0; i<p->pSrc->nSrc; i++){

  96873.       struct SrcList_item *pItem = &p->pSrc->a[i];

  96874.       if( pItem->pSelect && (pItem->pSelect->selFlags & SF_Resolved)==0 ){

  96875.         NameContext *pNC;         /* Used to iterate name contexts */

  96876.         int nRef = 0;             /* Refcount for pOuterNC and outer contexts */

  96877.         const char *zSavedContext = pParse->zAuthContext;

  96878. 

  96879.         /* Count the total number of references to pOuterNC and all of its

  96880.         ** parent contexts. After resolving references to expressions in

  96881.         ** pItem->pSelect, check if this value has changed. If so, then

  96882.         ** SELECT statement pItem->pSelect must be correlated. Set the

  96883.         ** pItem->fg.isCorrelated flag if this is the case. */

  96884.         for(pNC=pOuterNC; pNC; pNC=pNC->pNext) nRef += pNC->nRef;

  96885. 

  96886.         if( pItem->zName ) pParse->zAuthContext = pItem->zName;

  96887.         sqlite3ResolveSelectNames(pParse, pItem->pSelect, pOuterNC);

  96888.         pParse->zAuthContext = zSavedContext;

  96889.         if( pParse->nErr || db->mallocFailed ) return WRC_Abort;

  96890. 

  96891.         for(pNC=pOuterNC; pNC; pNC=pNC->pNext) nRef -= pNC->nRef;

  96892.         assert( pItem->fg.isCorrelated==0 && nRef<=0 );

  96893.         pItem->fg.isCorrelated = (nRef!=0);

  96894.       }

  96895.     }

  96896.   

  96897.     /* Set up the local name-context to pass to sqlite3ResolveExprNames() to

  96898.     ** resolve the result-set expression list.

  96899.     */

  96900.     sNC.ncFlags = NC_AllowAgg|NC_AllowWin;

  96901.     sNC.pSrcList = p->pSrc;

  96902.     sNC.pNext = pOuterNC;

  96903.   

  96904.     /* Resolve names in the result set. */

  96905.     if( sqlite3ResolveExprListNames(&sNC, p->pEList) ) return WRC_Abort;

  96906.     sNC.ncFlags &= ~NC_AllowWin;

  96907.   

  96908.     /* If there are no aggregate functions in the result-set, and no GROUP BY 

  96909.     ** expression, do not allow aggregates in any of the other expressions.

  96910.     */

  96911.     assert( (p->selFlags & SF_Aggregate)==0 );

  96912.     pGroupBy = p->pGroupBy;

  96913.     if( pGroupBy || (sNC.ncFlags & NC_HasAgg)!=0 ){

  96914.       assert( NC_MinMaxAgg==SF_MinMaxAgg );

  96915.       p->selFlags |= SF_Aggregate | (sNC.ncFlags&NC_MinMaxAgg);

  96916.     }else{

  96917.       sNC.ncFlags &= ~NC_AllowAgg;

  96918.     }

  96919.   

  96920.     /* If a HAVING clause is present, then there must be a GROUP BY clause.

  96921.     */

  96922.     if( p->pHaving && !pGroupBy ){

  96923.       sqlite3ErrorMsg(pParse, "a GROUP BY clause is required before HAVING");

  96924.       return WRC_Abort;

  96925.     }

  96926.   

  96927.     /* Add the output column list to the name-context before parsing the

  96928.     ** other expressions in the SELECT statement. This is so that

  96929.     ** expressions in the WHERE clause (etc.) can refer to expressions by

  96930.     ** aliases in the result set.

  96931.     **

  96932.     ** Minor point: If this is the case, then the expression will be

  96933.     ** re-evaluated for each reference to it.

  96934.     */

  96935.     assert( (sNC.ncFlags & (NC_UAggInfo|NC_UUpsert))==0 );

  96936.     sNC.uNC.pEList = p->pEList;

  96937.     sNC.ncFlags |= NC_UEList;

  96938.     if( sqlite3ResolveExprNames(&sNC, p->pHaving) ) return WRC_Abort;

  96939.     if( sqlite3ResolveExprNames(&sNC, p->pWhere) ) return WRC_Abort;

  96940. 

  96941.     /* Resolve names in table-valued-function arguments */

  96942.     for(i=0; i<p->pSrc->nSrc; i++){

  96943.       struct SrcList_item *pItem = &p->pSrc->a[i];

  96944.       if( pItem->fg.isTabFunc

  96945.        && sqlite3ResolveExprListNames(&sNC, pItem->u1.pFuncArg) 

  96946.       ){

  96947.         return WRC_Abort;

  96948.       }

  96949.     }

  96950. 

  96951.     /* The ORDER BY and GROUP BY clauses may not refer to terms in

  96952.     ** outer queries 

  96953.     */

  96954.     sNC.pNext = 0;

  96955.     sNC.ncFlags |= NC_AllowAgg|NC_AllowWin;

  96956. 

  96957.     /* If this is a converted compound query, move the ORDER BY clause from 

  96958.     ** the sub-query back to the parent query. At this point each term

  96959.     ** within the ORDER BY clause has been transformed to an integer value.

  96960.     ** These integers will be replaced by copies of the corresponding result

  96961.     ** set expressions by the call to resolveOrderGroupBy() below.  */

  96962.     if( p->selFlags & SF_Converted ){

  96963.       Select *pSub = p->pSrc->a[0].pSelect;

  96964.       p->pOrderBy = pSub->pOrderBy;

  96965.       pSub->pOrderBy = 0;

  96966.     }

  96967. 

  96968.     /* Process the ORDER BY clause for singleton SELECT statements.

  96969.     ** The ORDER BY clause for compounds SELECT statements is handled

  96970.     ** below, after all of the result-sets for all of the elements of

  96971.     ** the compound have been resolved.

  96972.     **

  96973.     ** If there is an ORDER BY clause on a term of a compound-select other

  96974.     ** than the right-most term, then that is a syntax error.  But the error

  96975.     ** is not detected until much later, and so we need to go ahead and

  96976.     ** resolve those symbols on the incorrect ORDER BY for consistency.

  96977.     */

  96978.     if( isCompound<=nCompound  /* Defer right-most ORDER BY of a compound */

  96979.      && resolveOrderGroupBy(&sNC, p, p->pOrderBy, "ORDER")

  96980.     ){

  96981.       return WRC_Abort;

  96982.     }

  96983.     if( db->mallocFailed ){

  96984.       return WRC_Abort;

  96985.     }

  96986.     sNC.ncFlags &= ~NC_AllowWin;

  96987.   

  96988.     /* Resolve the GROUP BY clause.  At the same time, make sure 

  96989.     ** the GROUP BY clause does not contain aggregate functions.

  96990.     */

  96991.     if( pGroupBy ){

  96992.       struct ExprList_item *pItem;

  96993.     

  96994.       if( resolveOrderGroupBy(&sNC, p, pGroupBy, "GROUP") || db->mallocFailed ){

  96995.         return WRC_Abort;

  96996.       }

  96997.       for(i=0, pItem=pGroupBy->a; i<pGroupBy->nExpr; i++, pItem++){

  96998.         if( ExprHasProperty(pItem->pExpr, EP_Agg) ){

  96999.           sqlite3ErrorMsg(pParse, "aggregate functions are not allowed in "

  97000.               "the GROUP BY clause");

  97001.           return WRC_Abort;

  97002.         }

  97003.       }

  97004.     }

  97005. 

  97006. #ifndef SQLITE_OMIT_WINDOWFUNC

  97007.     if( IN_RENAME_OBJECT ){

  97008.       Window *pWin;

  97009.       for(pWin=p->pWinDefn; pWin; pWin=pWin->pNextWin){

  97010.         if( sqlite3ResolveExprListNames(&sNC, pWin->pOrderBy)

  97011.          || sqlite3ResolveExprListNames(&sNC, pWin->pPartition)

  97012.         ){

  97013.           return WRC_Abort;

  97014.         }

  97015.       }

  97016.     }

  97017. #endif

  97018. 

  97019.     /* If this is part of a compound SELECT, check that it has the right

  97020.     ** number of expressions in the select list. */

  97021.     if( p->pNext && p->pEList->nExpr!=p->pNext->pEList->nExpr ){

  97022.       sqlite3SelectWrongNumTermsError(pParse, p->pNext);

  97023.       return WRC_Abort;

  97024.     }

  97025. 

  97026.     /* Advance to the next term of the compound

  97027.     */

  97028.     p = p->pPrior;

  97029.     nCompound++;

  97030.   }

  97031. 

  97032.   /* Resolve the ORDER BY on a compound SELECT after all terms of

  97033.   ** the compound have been resolved.

  97034.   */

  97035.   if( isCompound && resolveCompoundOrderBy(pParse, pLeftmost) ){

  97036.     return WRC_Abort;

  97037.   }

  97038. 

  97039.   return WRC_Prune;

  97040. }

  97041. 

  97042. /*

  97043. ** This routine walks an expression tree and resolves references to

  97044. ** table columns and result-set columns.  At the same time, do error

  97045. ** checking on function usage and set a flag if any aggregate functions

  97046. ** are seen.

  97047. **

  97048. ** To resolve table columns references we look for nodes (or subtrees) of the 

  97049. ** form X.Y.Z or Y.Z or just Z where

  97050. **

  97051. **      X:   The name of a database.  Ex:  "main" or "temp" or

  97052. **           the symbolic name assigned to an ATTACH-ed database.

  97053. **

  97054. **      Y:   The name of a table in a FROM clause.  Or in a trigger

  97055. **           one of the special names "old" or "new".

  97056. **

  97057. **      Z:   The name of a column in table Y.

  97058. **

  97059. ** The node at the root of the subtree is modified as follows:

  97060. **

  97061. **    Expr.op        Changed to TK_COLUMN

  97062. **    Expr.pTab      Points to the Table object for X.Y

  97063. **    Expr.iColumn   The column index in X.Y.  -1 for the rowid.

  97064. **    Expr.iTable    The VDBE cursor number for X.Y

  97065. **

  97066. **

  97067. ** To resolve result-set references, look for expression nodes of the

  97068. ** form Z (with no X and Y prefix) where the Z matches the right-hand

  97069. ** size of an AS clause in the result-set of a SELECT.  The Z expression

  97070. ** is replaced by a copy of the left-hand side of the result-set expression.

  97071. ** Table-name and function resolution occurs on the substituted expression

  97072. ** tree.  For example, in:

  97073. **

  97074. **      SELECT a+b AS x, c+d AS y FROM t1 ORDER BY x;

  97075. **

  97076. ** The "x" term of the order by is replaced by "a+b" to render:

  97077. **

  97078. **      SELECT a+b AS x, c+d AS y FROM t1 ORDER BY a+b;

  97079. **

  97080. ** Function calls are checked to make sure that the function is 

  97081. ** defined and that the correct number of arguments are specified.

  97082. ** If the function is an aggregate function, then the NC_HasAgg flag is

  97083. ** set and the opcode is changed from TK_FUNCTION to TK_AGG_FUNCTION.

  97084. ** If an expression contains aggregate functions then the EP_Agg

  97085. ** property on the expression is set.

  97086. **

  97087. ** An error message is left in pParse if anything is amiss.  The number

  97088. ** if errors is returned.

  97089. */

  97090. SQLITE_PRIVATE int sqlite3ResolveExprNames( 

  97091.   NameContext *pNC,       /* Namespace to resolve expressions in. */

  97092.   Expr *pExpr             /* The expression to be analyzed. */

  97093. ){

  97094.   int savedHasAgg;

  97095.   Walker w;

  97096. 

  97097.   if( pExpr==0 ) return SQLITE_OK;

  97098.   savedHasAgg = pNC->ncFlags & (NC_HasAgg|NC_MinMaxAgg|NC_HasWin);

  97099.   pNC->ncFlags &= ~(NC_HasAgg|NC_MinMaxAgg|NC_HasWin);

  97100.   w.pParse = pNC->pParse;

  97101.   w.xExprCallback = resolveExprStep;

  97102.   w.xSelectCallback = resolveSelectStep;

  97103.   w.xSelectCallback2 = 0;

  97104.   w.u.pNC = pNC;

  97105. #if SQLITE_MAX_EXPR_DEPTH>0

  97106.   w.pParse->nHeight += pExpr->nHeight;

  97107.   if( sqlite3ExprCheckHeight(w.pParse, w.pParse->nHeight) ){

  97108.     return SQLITE_ERROR;

  97109.   }

  97110. #endif

  97111.   sqlite3WalkExpr(&w, pExpr);

  97112. #if SQLITE_MAX_EXPR_DEPTH>0

  97113.   w.pParse->nHeight -= pExpr->nHeight;

  97114. #endif

  97115.   assert( EP_Agg==NC_HasAgg );

  97116.   assert( EP_Win==NC_HasWin );

  97117.   testcase( pNC->ncFlags & NC_HasAgg );

  97118.   testcase( pNC->ncFlags & NC_HasWin );

  97119.   ExprSetProperty(pExpr, pNC->ncFlags & (NC_HasAgg|NC_HasWin) );

  97120.   pNC->ncFlags |= savedHasAgg;

  97121.   return pNC->nErr>0 || w.pParse->nErr>0;

  97122. }

  97123. 

  97124. /*

  97125. ** Resolve all names for all expression in an expression list.  This is

  97126. ** just like sqlite3ResolveExprNames() except that it works for an expression

  97127. ** list rather than a single expression.

  97128. */

  97129. SQLITE_PRIVATE int sqlite3ResolveExprListNames( 

  97130.   NameContext *pNC,       /* Namespace to resolve expressions in. */

  97131.   ExprList *pList         /* The expression list to be analyzed. */

  97132. ){

  97133.   int i;

  97134.   if( pList ){

  97135.     for(i=0; i<pList->nExpr; i++){

  97136.       if( sqlite3ResolveExprNames(pNC, pList->a[i].pExpr) ) return WRC_Abort;

  97137.     }

  97138.   }

  97139.   return WRC_Continue;

  97140. }

  97141. 

  97142. /*

  97143. ** Resolve all names in all expressions of a SELECT and in all

  97144. ** decendents of the SELECT, including compounds off of p->pPrior,

  97145. ** subqueries in expressions, and subqueries used as FROM clause

  97146. ** terms.

  97147. **

  97148. ** See sqlite3ResolveExprNames() for a description of the kinds of

  97149. ** transformations that occur.

  97150. **

  97151. ** All SELECT statements should have been expanded using

  97152. ** sqlite3SelectExpand() prior to invoking this routine.

  97153. */

  97154. SQLITE_PRIVATE void sqlite3ResolveSelectNames(

  97155.   Parse *pParse,         /* The parser context */

  97156.   Select *p,             /* The SELECT statement being coded. */

  97157.   NameContext *pOuterNC  /* Name context for parent SELECT statement */

  97158. ){

  97159.   Walker w;

  97160. 

  97161.   assert( p!=0 );

  97162.   w.xExprCallback = resolveExprStep;

  97163.   w.xSelectCallback = resolveSelectStep;

  97164.   w.xSelectCallback2 = 0;

  97165.   w.pParse = pParse;

  97166.   w.u.pNC = pOuterNC;

  97167.   sqlite3WalkSelect(&w, p);

  97168. }

  97169. 

  97170. /*

  97171. ** Resolve names in expressions that can only reference a single table

  97172. ** or which cannot reference any tables at all.  Examples:

  97173. **

  97174. **    (1)   CHECK constraints

  97175. **    (2)   WHERE clauses on partial indices

  97176. **    (3)   Expressions in indexes on expressions

  97177. **    (4)   Expression arguments to VACUUM INTO.

  97178. **

  97179. ** In all cases except (4), the Expr.iTable value for Expr.op==TK_COLUMN

  97180. ** nodes of the expression is set to -1 and the Expr.iColumn value is

  97181. ** set to the column number.  In case (4), TK_COLUMN nodes cause an error.

  97182. **

  97183. ** Any errors cause an error message to be set in pParse.

  97184. */

  97185. SQLITE_PRIVATE int sqlite3ResolveSelfReference(

  97186.   Parse *pParse,      /* Parsing context */

  97187.   Table *pTab,        /* The table being referenced, or NULL */

  97188.   int type,           /* NC_IsCheck or NC_PartIdx or NC_IdxExpr, or 0 */

  97189.   Expr *pExpr,        /* Expression to resolve.  May be NULL. */

  97190.   ExprList *pList     /* Expression list to resolve.  May be NULL. */

  97191. ){

  97192.   SrcList sSrc;                   /* Fake SrcList for pParse->pNewTable */

  97193.   NameContext sNC;                /* Name context for pParse->pNewTable */

  97194.   int rc;

  97195. 

  97196.   assert( type==0 || pTab!=0 );

  97197.   assert( type==NC_IsCheck || type==NC_PartIdx || type==NC_IdxExpr || pTab==0 );

  97198.   memset(&sNC, 0, sizeof(sNC));

  97199.   memset(&sSrc, 0, sizeof(sSrc));

  97200.   if( pTab ){

  97201.     sSrc.nSrc = 1;

  97202.     sSrc.a[0].zName = pTab->zName;

  97203.     sSrc.a[0].pTab = pTab;

  97204.     sSrc.a[0].iCursor = -1;

  97205.   }

  97206.   sNC.pParse = pParse;

  97207.   sNC.pSrcList = &sSrc;

  97208.   sNC.ncFlags = type | NC_IsDDL;

  97209.   if( (rc = sqlite3ResolveExprNames(&sNC, pExpr))!=SQLITE_OK ) return rc;

  97210.   if( pList ) rc = sqlite3ResolveExprListNames(&sNC, pList);

  97211.   return rc;

  97212. }

  97213. 

  97214. /************** End of resolve.c *********************************************/

  97215. /************** Begin file expr.c ********************************************/

  97216. /*

  97217. ** 2001 September 15

  97218. **

  97219. ** The author disclaims copyright to this source code.  In place of

  97220. ** a legal notice, here is a blessing:

  97221. **

  97222. **    May you do good and not evil.

  97223. **    May you find forgiveness for yourself and forgive others.

  97224. **    May you share freely, never taking more than you give.

  97225. **

  97226. *************************************************************************

  97227. ** This file contains routines used for analyzing expressions and

  97228. ** for generating VDBE code that evaluates expressions in SQLite.

  97229. */

  97230. /* #include "sqliteInt.h" */

  97231. 

  97232. /* Forward declarations */

  97233. static void exprCodeBetween(Parse*,Expr*,int,void(*)(Parse*,Expr*,int,int),int);

  97234. static int exprCodeVector(Parse *pParse, Expr *p, int *piToFree);

  97235. 

  97236. /*

  97237. ** Return the affinity character for a single column of a table.

  97238. */

  97239. SQLITE_PRIVATE char sqlite3TableColumnAffinity(Table *pTab, int iCol){

  97240.   assert( iCol<pTab->nCol );

  97241.   return iCol>=0 ? pTab->aCol[iCol].affinity : SQLITE_AFF_INTEGER;

  97242. }

  97243. 

  97244. /*

  97245. ** Return the 'affinity' of the expression pExpr if any.

  97246. **

  97247. ** If pExpr is a column, a reference to a column via an 'AS' alias,

  97248. ** or a sub-select with a column as the return value, then the 

  97249. ** affinity of that column is returned. Otherwise, 0x00 is returned,

  97250. ** indicating no affinity for the expression.

  97251. **

  97252. ** i.e. the WHERE clause expressions in the following statements all

  97253. ** have an affinity:

  97254. **

  97255. ** CREATE TABLE t1(a);

  97256. ** SELECT * FROM t1 WHERE a;

  97257. ** SELECT a AS b FROM t1 WHERE b;

  97258. ** SELECT * FROM t1 WHERE (select a from t1);

  97259. */

  97260. SQLITE_PRIVATE char sqlite3ExprAffinity(Expr *pExpr){

  97261.   int op;

  97262.   if( pExpr->flags & EP_Generic ) return 0;

  97263.   while( ExprHasProperty(pExpr, EP_Skip) ){

  97264.     assert( pExpr->op==TK_COLLATE );

  97265.     pExpr = pExpr->pLeft;

  97266.     assert( pExpr!=0 );

  97267.   }

  97268.   op = pExpr->op;

  97269.   if( op==TK_SELECT ){

  97270.     assert( pExpr->flags&EP_xIsSelect );

  97271.     return sqlite3ExprAffinity(pExpr->x.pSelect->pEList->a[0].pExpr);

  97272.   }

  97273.   if( op==TK_REGISTER ) op = pExpr->op2;

  97274. #ifndef SQLITE_OMIT_CAST

  97275.   if( op==TK_CAST ){

  97276.     assert( !ExprHasProperty(pExpr, EP_IntValue) );

  97277.     return sqlite3AffinityType(pExpr->u.zToken, 0);

  97278.   }

  97279. #endif

  97280.   if( (op==TK_AGG_COLUMN || op==TK_COLUMN) && pExpr->y.pTab ){

  97281.     return sqlite3TableColumnAffinity(pExpr->y.pTab, pExpr->iColumn);

  97282.   }

  97283.   if( op==TK_SELECT_COLUMN ){

  97284.     assert( pExpr->pLeft->flags&EP_xIsSelect );

  97285.     return sqlite3ExprAffinity(

  97286.         pExpr->pLeft->x.pSelect->pEList->a[pExpr->iColumn].pExpr

  97287.     );

  97288.   }

  97289.   return pExpr->affinity;

  97290. }

  97291. 

  97292. /*

  97293. ** Set the collating sequence for expression pExpr to be the collating

  97294. ** sequence named by pToken.   Return a pointer to a new Expr node that

  97295. ** implements the COLLATE operator.

  97296. **

  97297. ** If a memory allocation error occurs, that fact is recorded in pParse->db

  97298. ** and the pExpr parameter is returned unchanged.

  97299. */

  97300. SQLITE_PRIVATE Expr *sqlite3ExprAddCollateToken(

  97301.   Parse *pParse,           /* Parsing context */

  97302.   Expr *pExpr,             /* Add the "COLLATE" clause to this expression */

  97303.   const Token *pCollName,  /* Name of collating sequence */

  97304.   int dequote              /* True to dequote pCollName */

  97305. ){

  97306.   if( pCollName->n>0 ){

  97307.     Expr *pNew = sqlite3ExprAlloc(pParse->db, TK_COLLATE, pCollName, dequote);

  97308.     if( pNew ){

  97309.       pNew->pLeft = pExpr;

  97310.       pNew->flags |= EP_Collate|EP_Skip;

  97311.       pExpr = pNew;

  97312.     }

  97313.   }

  97314.   return pExpr;

  97315. }

  97316. SQLITE_PRIVATE Expr *sqlite3ExprAddCollateString(Parse *pParse, Expr *pExpr, const char *zC){

  97317.   Token s;

  97318.   assert( zC!=0 );

  97319.   sqlite3TokenInit(&s, (char*)zC);

  97320.   return sqlite3ExprAddCollateToken(pParse, pExpr, &s, 0);

  97321. }

  97322. 

  97323. /*

  97324. ** Skip over any TK_COLLATE operators and any unlikely()

  97325. ** or likelihood() function at the root of an expression.

  97326. */

  97327. SQLITE_PRIVATE Expr *sqlite3ExprSkipCollate(Expr *pExpr){

  97328.   while( pExpr && ExprHasProperty(pExpr, EP_Skip|EP_Unlikely) ){

  97329.     if( ExprHasProperty(pExpr, EP_Unlikely) ){

  97330.       assert( !ExprHasProperty(pExpr, EP_xIsSelect) );

  97331.       assert( pExpr->x.pList->nExpr>0 );

  97332.       assert( pExpr->op==TK_FUNCTION );

  97333.       pExpr = pExpr->x.pList->a[0].pExpr;

  97334.     }else{

  97335.       assert( pExpr->op==TK_COLLATE );

  97336.       pExpr = pExpr->pLeft;

  97337.     }

  97338.   }   

  97339.   return pExpr;

  97340. }

  97341. 

  97342. /*

  97343. ** Return the collation sequence for the expression pExpr. If

  97344. ** there is no defined collating sequence, return NULL.

  97345. **

  97346. ** See also: sqlite3ExprNNCollSeq()

  97347. **

  97348. ** The sqlite3ExprNNCollSeq() works the same exact that it returns the

  97349. ** default collation if pExpr has no defined collation.

  97350. **

  97351. ** The collating sequence might be determined by a COLLATE operator

  97352. ** or by the presence of a column with a defined collating sequence.

  97353. ** COLLATE operators take first precedence.  Left operands take

  97354. ** precedence over right operands.

  97355. */

  97356. SQLITE_PRIVATE CollSeq *sqlite3ExprCollSeq(Parse *pParse, Expr *pExpr){

  97357.   sqlite3 *db = pParse->db;

  97358.   CollSeq *pColl = 0;

  97359.   Expr *p = pExpr;

  97360.   while( p ){

  97361.     int op = p->op;

  97362.     if( p->flags & EP_Generic ) break;

  97363.     if( op==TK_REGISTER ) op = p->op2;

  97364.     if( (op==TK_AGG_COLUMN || op==TK_COLUMN || op==TK_TRIGGER)

  97365.      && p->y.pTab!=0

  97366.     ){

  97367.       /* op==TK_REGISTER && p->y.pTab!=0 happens when pExpr was originally

  97368.       ** a TK_COLUMN but was previously evaluated and cached in a register */

  97369.       int j = p->iColumn;

  97370.       if( j>=0 ){

  97371.         const char *zColl = p->y.pTab->aCol[j].zColl;

  97372.         pColl = sqlite3FindCollSeq(db, ENC(db), zColl, 0);

  97373.       }

  97374.       break;

  97375.     }

  97376.     if( op==TK_CAST || op==TK_UPLUS ){

  97377.       p = p->pLeft;

  97378.       continue;

  97379.     }

  97380.     if( op==TK_COLLATE ){

  97381.       pColl = sqlite3GetCollSeq(pParse, ENC(db), 0, p->u.zToken);

  97382.       break;

  97383.     }

  97384.     if( p->flags & EP_Collate ){

  97385.       if( p->pLeft && (p->pLeft->flags & EP_Collate)!=0 ){

  97386.         p = p->pLeft;

  97387.       }else{

  97388.         Expr *pNext  = p->pRight;

  97389.         /* The Expr.x union is never used at the same time as Expr.pRight */

  97390.         assert( p->x.pList==0 || p->pRight==0 );

  97391.         /* p->flags holds EP_Collate and p->pLeft->flags does not.  And

  97392.         ** p->x.pSelect cannot.  So if p->x.pLeft exists, it must hold at

  97393.         ** least one EP_Collate. Thus the following two ALWAYS. */

  97394.         if( p->x.pList!=0 && ALWAYS(!ExprHasProperty(p, EP_xIsSelect)) ){

  97395.           int i;

  97396.           for(i=0; ALWAYS(i<p->x.pList->nExpr); i++){

  97397.             if( ExprHasProperty(p->x.pList->a[i].pExpr, EP_Collate) ){

  97398.               pNext = p->x.pList->a[i].pExpr;

  97399.               break;

  97400.             }

  97401.           }

  97402.         }

  97403.         p = pNext;

  97404.       }

  97405.     }else{

  97406.       break;

  97407.     }

  97408.   }

  97409.   if( sqlite3CheckCollSeq(pParse, pColl) ){ 

  97410.     pColl = 0;

  97411.   }

  97412.   return pColl;

  97413. }

  97414. 

  97415. /*

  97416. ** Return the collation sequence for the expression pExpr. If

  97417. ** there is no defined collating sequence, return a pointer to the

  97418. ** defautl collation sequence.

  97419. **

  97420. ** See also: sqlite3ExprCollSeq()

  97421. **

  97422. ** The sqlite3ExprCollSeq() routine works the same except that it

  97423. ** returns NULL if there is no defined collation.

  97424. */

  97425. SQLITE_PRIVATE CollSeq *sqlite3ExprNNCollSeq(Parse *pParse, Expr *pExpr){

  97426.   CollSeq *p = sqlite3ExprCollSeq(pParse, pExpr);

  97427.   if( p==0 ) p = pParse->db->pDfltColl;

  97428.   assert( p!=0 );

  97429.   return p;

  97430. }

  97431. 

  97432. /*

  97433. ** Return TRUE if the two expressions have equivalent collating sequences.

  97434. */

  97435. SQLITE_PRIVATE int sqlite3ExprCollSeqMatch(Parse *pParse, Expr *pE1, Expr *pE2){

  97436.   CollSeq *pColl1 = sqlite3ExprNNCollSeq(pParse, pE1);

  97437.   CollSeq *pColl2 = sqlite3ExprNNCollSeq(pParse, pE2);

  97438.   return sqlite3StrICmp(pColl1->zName, pColl2->zName)==0;

  97439. }

  97440. 

  97441. /*

  97442. ** pExpr is an operand of a comparison operator.  aff2 is the

  97443. ** type affinity of the other operand.  This routine returns the

  97444. ** type affinity that should be used for the comparison operator.

  97445. */

  97446. SQLITE_PRIVATE char sqlite3CompareAffinity(Expr *pExpr, char aff2){

  97447.   char aff1 = sqlite3ExprAffinity(pExpr);

  97448.   if( aff1 && aff2 ){

  97449.     /* Both sides of the comparison are columns. If one has numeric

  97450.     ** affinity, use that. Otherwise use no affinity.

  97451.     */

  97452.     if( sqlite3IsNumericAffinity(aff1) || sqlite3IsNumericAffinity(aff2) ){

  97453.       return SQLITE_AFF_NUMERIC;

  97454.     }else{

  97455.       return SQLITE_AFF_BLOB;

  97456.     }

  97457.   }else if( !aff1 && !aff2 ){

  97458.     /* Neither side of the comparison is a column.  Compare the

  97459.     ** results directly.

  97460.     */

  97461.     return SQLITE_AFF_BLOB;

  97462.   }else{

  97463.     /* One side is a column, the other is not. Use the columns affinity. */

  97464.     assert( aff1==0 || aff2==0 );

  97465.     return (aff1 + aff2);

  97466.   }

  97467. }

  97468. 

  97469. /*

  97470. ** pExpr is a comparison operator.  Return the type affinity that should

  97471. ** be applied to both operands prior to doing the comparison.

  97472. */

  97473. static char comparisonAffinity(Expr *pExpr){

  97474.   char aff;

  97475.   assert( pExpr->op==TK_EQ || pExpr->op==TK_IN || pExpr->op==TK_LT ||

  97476.           pExpr->op==TK_GT || pExpr->op==TK_GE || pExpr->op==TK_LE ||

  97477.           pExpr->op==TK_NE || pExpr->op==TK_IS || pExpr->op==TK_ISNOT );

  97478.   assert( pExpr->pLeft );

  97479.   aff = sqlite3ExprAffinity(pExpr->pLeft);

  97480.   if( pExpr->pRight ){

  97481.     aff = sqlite3CompareAffinity(pExpr->pRight, aff);

  97482.   }else if( ExprHasProperty(pExpr, EP_xIsSelect) ){

  97483.     aff = sqlite3CompareAffinity(pExpr->x.pSelect->pEList->a[0].pExpr, aff);

  97484.   }else if( aff==0 ){

  97485.     aff = SQLITE_AFF_BLOB;

  97486.   }

  97487.   return aff;

  97488. }

  97489. 

  97490. /*

  97491. ** pExpr is a comparison expression, eg. '=', '<', IN(...) etc.

  97492. ** idx_affinity is the affinity of an indexed column. Return true

  97493. ** if the index with affinity idx_affinity may be used to implement

  97494. ** the comparison in pExpr.

  97495. */

  97496. SQLITE_PRIVATE int sqlite3IndexAffinityOk(Expr *pExpr, char idx_affinity){

  97497.   char aff = comparisonAffinity(pExpr);

  97498.   switch( aff ){

  97499.     case SQLITE_AFF_BLOB:

  97500.       return 1;

  97501.     case SQLITE_AFF_TEXT:

  97502.       return idx_affinity==SQLITE_AFF_TEXT;

  97503.     default:

  97504.       return sqlite3IsNumericAffinity(idx_affinity);

  97505.   }

  97506. }

  97507. 

  97508. /*

  97509. ** Return the P5 value that should be used for a binary comparison

  97510. ** opcode (OP_Eq, OP_Ge etc.) used to compare pExpr1 and pExpr2.

  97511. */

  97512. static u8 binaryCompareP5(Expr *pExpr1, Expr *pExpr2, int jumpIfNull){

  97513.   u8 aff = (char)sqlite3ExprAffinity(pExpr2);

  97514.   aff = (u8)sqlite3CompareAffinity(pExpr1, aff) | (u8)jumpIfNull;

  97515.   return aff;

  97516. }

  97517. 

  97518. /*

  97519. ** Return a pointer to the collation sequence that should be used by

  97520. ** a binary comparison operator comparing pLeft and pRight.

  97521. **

  97522. ** If the left hand expression has a collating sequence type, then it is

  97523. ** used. Otherwise the collation sequence for the right hand expression

  97524. ** is used, or the default (BINARY) if neither expression has a collating

  97525. ** type.

  97526. **

  97527. ** Argument pRight (but not pLeft) may be a null pointer. In this case,

  97528. ** it is not considered.

  97529. */

  97530. SQLITE_PRIVATE CollSeq *sqlite3BinaryCompareCollSeq(

  97531.   Parse *pParse, 

  97532.   Expr *pLeft, 

  97533.   Expr *pRight

  97534. ){

  97535.   CollSeq *pColl;

  97536.   assert( pLeft );

  97537.   if( pLeft->flags & EP_Collate ){

  97538.     pColl = sqlite3ExprCollSeq(pParse, pLeft);

  97539.   }else if( pRight && (pRight->flags & EP_Collate)!=0 ){

  97540.     pColl = sqlite3ExprCollSeq(pParse, pRight);

  97541.   }else{

  97542.     pColl = sqlite3ExprCollSeq(pParse, pLeft);

  97543.     if( !pColl ){

  97544.       pColl = sqlite3ExprCollSeq(pParse, pRight);

  97545.     }

  97546.   }

  97547.   return pColl;

  97548. }

  97549. 

  97550. /*

  97551. ** Generate code for a comparison operator.

  97552. */

  97553. static int codeCompare(

  97554.   Parse *pParse,    /* The parsing (and code generating) context */

  97555.   Expr *pLeft,      /* The left operand */

  97556.   Expr *pRight,     /* The right operand */

  97557.   int opcode,       /* The comparison opcode */

  97558.   int in1, int in2, /* Register holding operands */

  97559.   int dest,         /* Jump here if true.  */

  97560.   int jumpIfNull    /* If true, jump if either operand is NULL */

  97561. ){

  97562.   int p5;

  97563.   int addr;

  97564.   CollSeq *p4;

  97565. 

  97566.   p4 = sqlite3BinaryCompareCollSeq(pParse, pLeft, pRight);

  97567.   p5 = binaryCompareP5(pLeft, pRight, jumpIfNull);

  97568.   addr = sqlite3VdbeAddOp4(pParse->pVdbe, opcode, in2, dest, in1,

  97569.                            (void*)p4, P4_COLLSEQ);

  97570.   sqlite3VdbeChangeP5(pParse->pVdbe, (u8)p5);

  97571.   return addr;

  97572. }

  97573. 

  97574. /*

  97575. ** Return true if expression pExpr is a vector, or false otherwise.

  97576. **

  97577. ** A vector is defined as any expression that results in two or more

  97578. ** columns of result.  Every TK_VECTOR node is an vector because the

  97579. ** parser will not generate a TK_VECTOR with fewer than two entries.

  97580. ** But a TK_SELECT might be either a vector or a scalar. It is only

  97581. ** considered a vector if it has two or more result columns.

  97582. */

  97583. SQLITE_PRIVATE int sqlite3ExprIsVector(Expr *pExpr){

  97584.   return sqlite3ExprVectorSize(pExpr)>1;

  97585. }

  97586. 

  97587. /*

  97588. ** If the expression passed as the only argument is of type TK_VECTOR 

  97589. ** return the number of expressions in the vector. Or, if the expression

  97590. ** is a sub-select, return the number of columns in the sub-select. For

  97591. ** any other type of expression, return 1.

  97592. */

  97593. SQLITE_PRIVATE int sqlite3ExprVectorSize(Expr *pExpr){

  97594.   u8 op = pExpr->op;

  97595.   if( op==TK_REGISTER ) op = pExpr->op2;

  97596.   if( op==TK_VECTOR ){

  97597.     return pExpr->x.pList->nExpr;

  97598.   }else if( op==TK_SELECT ){

  97599.     return pExpr->x.pSelect->pEList->nExpr;

  97600.   }else{

  97601.     return 1;

  97602.   }

  97603. }

  97604. 

  97605. /*

  97606. ** Return a pointer to a subexpression of pVector that is the i-th

  97607. ** column of the vector (numbered starting with 0).  The caller must

  97608. ** ensure that i is within range.

  97609. **

  97610. ** If pVector is really a scalar (and "scalar" here includes subqueries

  97611. ** that return a single column!) then return pVector unmodified.

  97612. **

  97613. ** pVector retains ownership of the returned subexpression.

  97614. **

  97615. ** If the vector is a (SELECT ...) then the expression returned is

  97616. ** just the expression for the i-th term of the result set, and may

  97617. ** not be ready for evaluation because the table cursor has not yet

  97618. ** been positioned.

  97619. */

  97620. SQLITE_PRIVATE Expr *sqlite3VectorFieldSubexpr(Expr *pVector, int i){

  97621.   assert( i<sqlite3ExprVectorSize(pVector) );

  97622.   if( sqlite3ExprIsVector(pVector) ){

  97623.     assert( pVector->op2==0 || pVector->op==TK_REGISTER );

  97624.     if( pVector->op==TK_SELECT || pVector->op2==TK_SELECT ){

  97625.       return pVector->x.pSelect->pEList->a[i].pExpr;

  97626.     }else{

  97627.       return pVector->x.pList->a[i].pExpr;

  97628.     }

  97629.   }

  97630.   return pVector;

  97631. }

  97632. 

  97633. /*

  97634. ** Compute and return a new Expr object which when passed to

  97635. ** sqlite3ExprCode() will generate all necessary code to compute

  97636. ** the iField-th column of the vector expression pVector.

  97637. **

  97638. ** It is ok for pVector to be a scalar (as long as iField==0).  

  97639. ** In that case, this routine works like sqlite3ExprDup().

  97640. **

  97641. ** The caller owns the returned Expr object and is responsible for

  97642. ** ensuring that the returned value eventually gets freed.

  97643. **

  97644. ** The caller retains ownership of pVector.  If pVector is a TK_SELECT,

  97645. ** then the returned object will reference pVector and so pVector must remain

  97646. ** valid for the life of the returned object.  If pVector is a TK_VECTOR

  97647. ** or a scalar expression, then it can be deleted as soon as this routine

  97648. ** returns.

  97649. **

  97650. ** A trick to cause a TK_SELECT pVector to be deleted together with

  97651. ** the returned Expr object is to attach the pVector to the pRight field

  97652. ** of the returned TK_SELECT_COLUMN Expr object.

  97653. */

  97654. SQLITE_PRIVATE Expr *sqlite3ExprForVectorField(

  97655.   Parse *pParse,       /* Parsing context */

  97656.   Expr *pVector,       /* The vector.  List of expressions or a sub-SELECT */

  97657.   int iField           /* Which column of the vector to return */

  97658. ){

  97659.   Expr *pRet;

  97660.   if( pVector->op==TK_SELECT ){

  97661.     assert( pVector->flags & EP_xIsSelect );

  97662.     /* The TK_SELECT_COLUMN Expr node:

  97663.     **

  97664.     ** pLeft:           pVector containing TK_SELECT.  Not deleted.

  97665.     ** pRight:          not used.  But recursively deleted.

  97666.     ** iColumn:         Index of a column in pVector

  97667.     ** iTable:          0 or the number of columns on the LHS of an assignment

  97668.     ** pLeft->iTable:   First in an array of register holding result, or 0

  97669.     **                  if the result is not yet computed.

  97670.     **

  97671.     ** sqlite3ExprDelete() specifically skips the recursive delete of

  97672.     ** pLeft on TK_SELECT_COLUMN nodes.  But pRight is followed, so pVector

  97673.     ** can be attached to pRight to cause this node to take ownership of

  97674.     ** pVector.  Typically there will be multiple TK_SELECT_COLUMN nodes

  97675.     ** with the same pLeft pointer to the pVector, but only one of them

  97676.     ** will own the pVector.

  97677.     */

  97678.     pRet = sqlite3PExpr(pParse, TK_SELECT_COLUMN, 0, 0);

  97679.     if( pRet ){

  97680.       pRet->iColumn = iField;

  97681.       pRet->pLeft = pVector;

  97682.     }

  97683.     assert( pRet==0 || pRet->iTable==0 );

  97684.   }else{

  97685.     if( pVector->op==TK_VECTOR ) pVector = pVector->x.pList->a[iField].pExpr;

  97686.     pRet = sqlite3ExprDup(pParse->db, pVector, 0);

  97687.     sqlite3RenameTokenRemap(pParse, pRet, pVector);

  97688.   }

  97689.   return pRet;

  97690. }

  97691. 

  97692. /*

  97693. ** If expression pExpr is of type TK_SELECT, generate code to evaluate

  97694. ** it. Return the register in which the result is stored (or, if the 

  97695. ** sub-select returns more than one column, the first in an array

  97696. ** of registers in which the result is stored).

  97697. **

  97698. ** If pExpr is not a TK_SELECT expression, return 0.

  97699. */

  97700. static int exprCodeSubselect(Parse *pParse, Expr *pExpr){

  97701.   int reg = 0;

  97702. #ifndef SQLITE_OMIT_SUBQUERY

  97703.   if( pExpr->op==TK_SELECT ){

  97704.     reg = sqlite3CodeSubselect(pParse, pExpr);

  97705.   }

  97706. #endif

  97707.   return reg;

  97708. }

  97709. 

  97710. /*

  97711. ** Argument pVector points to a vector expression - either a TK_VECTOR

  97712. ** or TK_SELECT that returns more than one column. This function returns

  97713. ** the register number of a register that contains the value of

  97714. ** element iField of the vector.

  97715. **

  97716. ** If pVector is a TK_SELECT expression, then code for it must have 

  97717. ** already been generated using the exprCodeSubselect() routine. In this

  97718. ** case parameter regSelect should be the first in an array of registers

  97719. ** containing the results of the sub-select. 

  97720. **

  97721. ** If pVector is of type TK_VECTOR, then code for the requested field

  97722. ** is generated. In this case (*pRegFree) may be set to the number of

  97723. ** a temporary register to be freed by the caller before returning.

  97724. **

  97725. ** Before returning, output parameter (*ppExpr) is set to point to the

  97726. ** Expr object corresponding to element iElem of the vector.

  97727. */

  97728. static int exprVectorRegister(

  97729.   Parse *pParse,                  /* Parse context */

  97730.   Expr *pVector,                  /* Vector to extract element from */

  97731.   int iField,                     /* Field to extract from pVector */

  97732.   int regSelect,                  /* First in array of registers */

  97733.   Expr **ppExpr,                  /* OUT: Expression element */

  97734.   int *pRegFree                   /* OUT: Temp register to free */

  97735. ){

  97736.   u8 op = pVector->op;

  97737.   assert( op==TK_VECTOR || op==TK_REGISTER || op==TK_SELECT );

  97738.   if( op==TK_REGISTER ){

  97739.     *ppExpr = sqlite3VectorFieldSubexpr(pVector, iField);

  97740.     return pVector->iTable+iField;

  97741.   }

  97742.   if( op==TK_SELECT ){

  97743.     *ppExpr = pVector->x.pSelect->pEList->a[iField].pExpr;

  97744.      return regSelect+iField;

  97745.   }

  97746.   *ppExpr = pVector->x.pList->a[iField].pExpr;

  97747.   return sqlite3ExprCodeTemp(pParse, *ppExpr, pRegFree);

  97748. }

  97749. 

  97750. /*

  97751. ** Expression pExpr is a comparison between two vector values. Compute

  97752. ** the result of the comparison (1, 0, or NULL) and write that

  97753. ** result into register dest.

  97754. **

  97755. ** The caller must satisfy the following preconditions:

  97756. **

  97757. **    if pExpr->op==TK_IS:      op==TK_EQ and p5==SQLITE_NULLEQ

  97758. **    if pExpr->op==TK_ISNOT:   op==TK_NE and p5==SQLITE_NULLEQ

  97759. **    otherwise:                op==pExpr->op and p5==0

  97760. */

  97761. static void codeVectorCompare(

  97762.   Parse *pParse,        /* Code generator context */

  97763.   Expr *pExpr,          /* The comparison operation */

  97764.   int dest,             /* Write results into this register */

  97765.   u8 op,                /* Comparison operator */

  97766.   u8 p5                 /* SQLITE_NULLEQ or zero */

  97767. ){

  97768.   Vdbe *v = pParse->pVdbe;

  97769.   Expr *pLeft = pExpr->pLeft;

  97770.   Expr *pRight = pExpr->pRight;

  97771.   int nLeft = sqlite3ExprVectorSize(pLeft);

  97772.   int i;

  97773.   int regLeft = 0;

  97774.   int regRight = 0;

  97775.   u8 opx = op;

  97776.   int addrDone = sqlite3VdbeMakeLabel(pParse);

  97777. 

  97778.   if( nLeft!=sqlite3ExprVectorSize(pRight) ){

  97779.     sqlite3ErrorMsg(pParse, "row value misused");

  97780.     return;

  97781.   }

  97782.   assert( pExpr->op==TK_EQ || pExpr->op==TK_NE 

  97783.        || pExpr->op==TK_IS || pExpr->op==TK_ISNOT 

  97784.        || pExpr->op==TK_LT || pExpr->op==TK_GT 

  97785.        || pExpr->op==TK_LE || pExpr->op==TK_GE 

  97786.   );

  97787.   assert( pExpr->op==op || (pExpr->op==TK_IS && op==TK_EQ)

  97788.             || (pExpr->op==TK_ISNOT && op==TK_NE) );

  97789.   assert( p5==0 || pExpr->op!=op );

  97790.   assert( p5==SQLITE_NULLEQ || pExpr->op==op );

  97791. 

  97792.   p5 |= SQLITE_STOREP2;

  97793.   if( opx==TK_LE ) opx = TK_LT;

  97794.   if( opx==TK_GE ) opx = TK_GT;

  97795. 

  97796.   regLeft = exprCodeSubselect(pParse, pLeft);

  97797.   regRight = exprCodeSubselect(pParse, pRight);

  97798. 

  97799.   for(i=0; 1 /*Loop exits by "break"*/; i++){

  97800.     int regFree1 = 0, regFree2 = 0;

  97801.     Expr *pL, *pR; 

  97802.     int r1, r2;

  97803.     assert( i>=0 && i<nLeft );

  97804.     r1 = exprVectorRegister(pParse, pLeft, i, regLeft, &pL, &regFree1);

  97805.     r2 = exprVectorRegister(pParse, pRight, i, regRight, &pR, &regFree2);

  97806.     codeCompare(pParse, pL, pR, opx, r1, r2, dest, p5);

  97807.     testcase(op==OP_Lt); VdbeCoverageIf(v,op==OP_Lt);

  97808.     testcase(op==OP_Le); VdbeCoverageIf(v,op==OP_Le);

  97809.     testcase(op==OP_Gt); VdbeCoverageIf(v,op==OP_Gt);

  97810.     testcase(op==OP_Ge); VdbeCoverageIf(v,op==OP_Ge);

  97811.     testcase(op==OP_Eq); VdbeCoverageIf(v,op==OP_Eq);

  97812.     testcase(op==OP_Ne); VdbeCoverageIf(v,op==OP_Ne);

  97813.     sqlite3ReleaseTempReg(pParse, regFree1);

  97814.     sqlite3ReleaseTempReg(pParse, regFree2);

  97815.     if( i==nLeft-1 ){

  97816.       break;

  97817.     }

  97818.     if( opx==TK_EQ ){

  97819.       sqlite3VdbeAddOp2(v, OP_IfNot, dest, addrDone); VdbeCoverage(v);

  97820.       p5 |= SQLITE_KEEPNULL;

  97821.     }else if( opx==TK_NE ){

  97822.       sqlite3VdbeAddOp2(v, OP_If, dest, addrDone); VdbeCoverage(v);

  97823.       p5 |= SQLITE_KEEPNULL;

  97824.     }else{

  97825.       assert( op==TK_LT || op==TK_GT || op==TK_LE || op==TK_GE );

  97826.       sqlite3VdbeAddOp2(v, OP_ElseNotEq, 0, addrDone);

  97827.       VdbeCoverageIf(v, op==TK_LT);

  97828.       VdbeCoverageIf(v, op==TK_GT);

  97829.       VdbeCoverageIf(v, op==TK_LE);

  97830.       VdbeCoverageIf(v, op==TK_GE);

  97831.       if( i==nLeft-2 ) opx = op;

  97832.     }

  97833.   }

  97834.   sqlite3VdbeResolveLabel(v, addrDone);

  97835. }

  97836. 

  97837. #if SQLITE_MAX_EXPR_DEPTH>0

  97838. /*

  97839. ** Check that argument nHeight is less than or equal to the maximum

  97840. ** expression depth allowed. If it is not, leave an error message in

  97841. ** pParse.

  97842. */

  97843. SQLITE_PRIVATE int sqlite3ExprCheckHeight(Parse *pParse, int nHeight){

  97844.   int rc = SQLITE_OK;

  97845.   int mxHeight = pParse->db->aLimit[SQLITE_LIMIT_EXPR_DEPTH];

  97846.   if( nHeight>mxHeight ){

  97847.     sqlite3ErrorMsg(pParse, 

  97848.        "Expression tree is too large (maximum depth %d)", mxHeight

  97849.     );

  97850.     rc = SQLITE_ERROR;

  97851.   }

  97852.   return rc;

  97853. }

  97854. 

  97855. /* The following three functions, heightOfExpr(), heightOfExprList()

  97856. ** and heightOfSelect(), are used to determine the maximum height

  97857. ** of any expression tree referenced by the structure passed as the

  97858. ** first argument.

  97859. **

  97860. ** If this maximum height is greater than the current value pointed

  97861. ** to by pnHeight, the second parameter, then set *pnHeight to that

  97862. ** value.

  97863. */

  97864. static void heightOfExpr(Expr *p, int *pnHeight){

  97865.   if( p ){

  97866.     if( p->nHeight>*pnHeight ){

  97867.       *pnHeight = p->nHeight;

  97868.     }

  97869.   }

  97870. }

  97871. static void heightOfExprList(ExprList *p, int *pnHeight){

  97872.   if( p ){

  97873.     int i;

  97874.     for(i=0; i<p->nExpr; i++){

  97875.       heightOfExpr(p->a[i].pExpr, pnHeight);

  97876.     }

  97877.   }

  97878. }

  97879. static void heightOfSelect(Select *pSelect, int *pnHeight){

  97880.   Select *p;

  97881.   for(p=pSelect; p; p=p->pPrior){

  97882.     heightOfExpr(p->pWhere, pnHeight);

  97883.     heightOfExpr(p->pHaving, pnHeight);

  97884.     heightOfExpr(p->pLimit, pnHeight);

  97885.     heightOfExprList(p->pEList, pnHeight);

  97886.     heightOfExprList(p->pGroupBy, pnHeight);

  97887.     heightOfExprList(p->pOrderBy, pnHeight);

  97888.   }

  97889. }

  97890. 

  97891. /*

  97892. ** Set the Expr.nHeight variable in the structure passed as an 

  97893. ** argument. An expression with no children, Expr.pList or 

  97894. ** Expr.pSelect member has a height of 1. Any other expression

  97895. ** has a height equal to the maximum height of any other 

  97896. ** referenced Expr plus one.

  97897. **

  97898. ** Also propagate EP_Propagate flags up from Expr.x.pList to Expr.flags,

  97899. ** if appropriate.

  97900. */

  97901. static void exprSetHeight(Expr *p){

  97902.   int nHeight = 0;

  97903.   heightOfExpr(p->pLeft, &nHeight);

  97904.   heightOfExpr(p->pRight, &nHeight);

  97905.   if( ExprHasProperty(p, EP_xIsSelect) ){

  97906.     heightOfSelect(p->x.pSelect, &nHeight);

  97907.   }else if( p->x.pList ){

  97908.     heightOfExprList(p->x.pList, &nHeight);

  97909.     p->flags |= EP_Propagate & sqlite3ExprListFlags(p->x.pList);

  97910.   }

  97911.   p->nHeight = nHeight + 1;

  97912. }

  97913. 

  97914. /*

  97915. ** Set the Expr.nHeight variable using the exprSetHeight() function. If

  97916. ** the height is greater than the maximum allowed expression depth,

  97917. ** leave an error in pParse.

  97918. **

  97919. ** Also propagate all EP_Propagate flags from the Expr.x.pList into

  97920. ** Expr.flags. 

  97921. */

  97922. SQLITE_PRIVATE void sqlite3ExprSetHeightAndFlags(Parse *pParse, Expr *p){

  97923.   if( pParse->nErr ) return;

  97924.   exprSetHeight(p);

  97925.   sqlite3ExprCheckHeight(pParse, p->nHeight);

  97926. }

  97927. 

  97928. /*

  97929. ** Return the maximum height of any expression tree referenced

  97930. ** by the select statement passed as an argument.

  97931. */

  97932. SQLITE_PRIVATE int sqlite3SelectExprHeight(Select *p){

  97933.   int nHeight = 0;

  97934.   heightOfSelect(p, &nHeight);

  97935.   return nHeight;

  97936. }

  97937. #else /* ABOVE:  Height enforcement enabled.  BELOW: Height enforcement off */

  97938. /*

  97939. ** Propagate all EP_Propagate flags from the Expr.x.pList into

  97940. ** Expr.flags. 

  97941. */

  97942. SQLITE_PRIVATE void sqlite3ExprSetHeightAndFlags(Parse *pParse, Expr *p){

  97943.   if( p && p->x.pList && !ExprHasProperty(p, EP_xIsSelect) ){

  97944.     p->flags |= EP_Propagate & sqlite3ExprListFlags(p->x.pList);

  97945.   }

  97946. }

  97947. #define exprSetHeight(y)

  97948. #endif /* SQLITE_MAX_EXPR_DEPTH>0 */

  97949. 

  97950. /*

  97951. ** This routine is the core allocator for Expr nodes.

  97952. **

  97953. ** Construct a new expression node and return a pointer to it.  Memory

  97954. ** for this node and for the pToken argument is a single allocation

  97955. ** obtained from sqlite3DbMalloc().  The calling function

  97956. ** is responsible for making sure the node eventually gets freed.

  97957. **

  97958. ** If dequote is true, then the token (if it exists) is dequoted.

  97959. ** If dequote is false, no dequoting is performed.  The deQuote

  97960. ** parameter is ignored if pToken is NULL or if the token does not

  97961. ** appear to be quoted.  If the quotes were of the form "..." (double-quotes)

  97962. ** then the EP_DblQuoted flag is set on the expression node.

  97963. **

  97964. ** Special case:  If op==TK_INTEGER and pToken points to a string that

  97965. ** can be translated into a 32-bit integer, then the token is not

  97966. ** stored in u.zToken.  Instead, the integer values is written

  97967. ** into u.iValue and the EP_IntValue flag is set.  No extra storage

  97968. ** is allocated to hold the integer text and the dequote flag is ignored.

  97969. */

  97970. SQLITE_PRIVATE Expr *sqlite3ExprAlloc(

  97971.   sqlite3 *db,            /* Handle for sqlite3DbMallocRawNN() */

  97972.   int op,                 /* Expression opcode */

  97973.   const Token *pToken,    /* Token argument.  Might be NULL */

  97974.   int dequote             /* True to dequote */

  97975. ){

  97976.   Expr *pNew;

  97977.   int nExtra = 0;

  97978.   int iValue = 0;

  97979. 

  97980.   assert( db!=0 );

  97981.   if( pToken ){

  97982.     if( op!=TK_INTEGER || pToken->z==0

  97983.           || sqlite3GetInt32(pToken->z, &iValue)==0 ){

  97984.       nExtra = pToken->n+1;

  97985.       assert( iValue>=0 );

  97986.     }

  97987.   }

  97988.   pNew = sqlite3DbMallocRawNN(db, sizeof(Expr)+nExtra);

  97989.   if( pNew ){

  97990.     memset(pNew, 0, sizeof(Expr));

  97991.     pNew->op = (u8)op;

  97992.     pNew->iAgg = -1;

  97993.     if( pToken ){

  97994.       if( nExtra==0 ){

  97995.         pNew->flags |= EP_IntValue|EP_Leaf|(iValue?EP_IsTrue:EP_IsFalse);

  97996.         pNew->u.iValue = iValue;

  97997.       }else{

  97998.         pNew->u.zToken = (char*)&pNew[1];

  97999.         assert( pToken->z!=0 || pToken->n==0 );

  98000.         if( pToken->n ) memcpy(pNew->u.zToken, pToken->z, pToken->n);

  98001.         pNew->u.zToken[pToken->n] = 0;

  98002.         if( dequote && sqlite3Isquote(pNew->u.zToken[0]) ){

  98003.           sqlite3DequoteExpr(pNew);

  98004.         }

  98005.       }

  98006.     }

  98007. #if SQLITE_MAX_EXPR_DEPTH>0

  98008.     pNew->nHeight = 1;

  98009. #endif  

  98010.   }

  98011.   return pNew;

  98012. }

  98013. 

  98014. /*

  98015. ** Allocate a new expression node from a zero-terminated token that has

  98016. ** already been dequoted.

  98017. */

  98018. SQLITE_PRIVATE Expr *sqlite3Expr(

  98019.   sqlite3 *db,            /* Handle for sqlite3DbMallocZero() (may be null) */

  98020.   int op,                 /* Expression opcode */

  98021.   const char *zToken      /* Token argument.  Might be NULL */

  98022. ){

  98023.   Token x;

  98024.   x.z = zToken;

  98025.   x.n = sqlite3Strlen30(zToken);

  98026.   return sqlite3ExprAlloc(db, op, &x, 0);

  98027. }

  98028. 

  98029. /*

  98030. ** Attach subtrees pLeft and pRight to the Expr node pRoot.

  98031. **

  98032. ** If pRoot==NULL that means that a memory allocation error has occurred.

  98033. ** In that case, delete the subtrees pLeft and pRight.

  98034. */

  98035. SQLITE_PRIVATE void sqlite3ExprAttachSubtrees(

  98036.   sqlite3 *db,

  98037.   Expr *pRoot,

  98038.   Expr *pLeft,

  98039.   Expr *pRight

  98040. ){

  98041.   if( pRoot==0 ){

  98042.     assert( db->mallocFailed );

  98043.     sqlite3ExprDelete(db, pLeft);

  98044.     sqlite3ExprDelete(db, pRight);

  98045.   }else{

  98046.     if( pRight ){

  98047.       pRoot->pRight = pRight;

  98048.       pRoot->flags |= EP_Propagate & pRight->flags;

  98049.     }

  98050.     if( pLeft ){

  98051.       pRoot->pLeft = pLeft;

  98052.       pRoot->flags |= EP_Propagate & pLeft->flags;

  98053.     }

  98054.     exprSetHeight(pRoot);

  98055.   }

  98056. }

  98057. 

  98058. /*

  98059. ** Allocate an Expr node which joins as many as two subtrees.

  98060. **

  98061. ** One or both of the subtrees can be NULL.  Return a pointer to the new

  98062. ** Expr node.  Or, if an OOM error occurs, set pParse->db->mallocFailed,

  98063. ** free the subtrees and return NULL.

  98064. */

  98065. SQLITE_PRIVATE Expr *sqlite3PExpr(

  98066.   Parse *pParse,          /* Parsing context */

  98067.   int op,                 /* Expression opcode */

  98068.   Expr *pLeft,            /* Left operand */

  98069.   Expr *pRight            /* Right operand */

  98070. ){

  98071.   Expr *p;

  98072.   p = sqlite3DbMallocRawNN(pParse->db, sizeof(Expr));

  98073.   if( p ){

  98074.     memset(p, 0, sizeof(Expr));

  98075.     p->op = op & 0xff;

  98076.     p->iAgg = -1;

  98077.     sqlite3ExprAttachSubtrees(pParse->db, p, pLeft, pRight);

  98078.     sqlite3ExprCheckHeight(pParse, p->nHeight);

  98079.   }else{

  98080.     sqlite3ExprDelete(pParse->db, pLeft);

  98081.     sqlite3ExprDelete(pParse->db, pRight);

  98082.   }

  98083.   return p;

  98084. }

  98085. 

  98086. /*

  98087. ** Add pSelect to the Expr.x.pSelect field.  Or, if pExpr is NULL (due

  98088. ** do a memory allocation failure) then delete the pSelect object.

  98089. */

  98090. SQLITE_PRIVATE void sqlite3PExprAddSelect(Parse *pParse, Expr *pExpr, Select *pSelect){

  98091.   if( pExpr ){

  98092.     pExpr->x.pSelect = pSelect;

  98093.     ExprSetProperty(pExpr, EP_xIsSelect|EP_Subquery);

  98094.     sqlite3ExprSetHeightAndFlags(pParse, pExpr);

  98095.   }else{

  98096.     assert( pParse->db->mallocFailed );

  98097.     sqlite3SelectDelete(pParse->db, pSelect);

  98098.   }

  98099. }

  98100. 

  98101. 

  98102. /*

  98103. ** Join two expressions using an AND operator.  If either expression is

  98104. ** NULL, then just return the other expression.

  98105. **

  98106. ** If one side or the other of the AND is known to be false, then instead

  98107. ** of returning an AND expression, just return a constant expression with

  98108. ** a value of false.

  98109. */

  98110. SQLITE_PRIVATE Expr *sqlite3ExprAnd(Parse *pParse, Expr *pLeft, Expr *pRight){

  98111.   sqlite3 *db = pParse->db;

  98112.   if( pLeft==0  ){

  98113.     return pRight;

  98114.   }else if( pRight==0 ){

  98115.     return pLeft;

  98116.   }else if( ExprAlwaysFalse(pLeft) || ExprAlwaysFalse(pRight) ){

  98117.     sqlite3ExprUnmapAndDelete(pParse, pLeft);

  98118.     sqlite3ExprUnmapAndDelete(pParse, pRight);

  98119.     return sqlite3ExprAlloc(db, TK_INTEGER, &sqlite3IntTokens[0], 0);

  98120.   }else{

  98121.     return sqlite3PExpr(pParse, TK_AND, pLeft, pRight);

  98122.   }

  98123. }

  98124. 

  98125. /*

  98126. ** Construct a new expression node for a function with multiple

  98127. ** arguments.

  98128. */

  98129. SQLITE_PRIVATE Expr *sqlite3ExprFunction(

  98130.   Parse *pParse,        /* Parsing context */

  98131.   ExprList *pList,      /* Argument list */

  98132.   Token *pToken,        /* Name of the function */

  98133.   int eDistinct         /* SF_Distinct or SF_ALL or 0 */

  98134. ){

  98135.   Expr *pNew;

  98136.   sqlite3 *db = pParse->db;

  98137.   assert( pToken );

  98138.   pNew = sqlite3ExprAlloc(db, TK_FUNCTION, pToken, 1);

  98139.   if( pNew==0 ){

  98140.     sqlite3ExprListDelete(db, pList); /* Avoid memory leak when malloc fails */

  98141.     return 0;

  98142.   }

  98143.   if( pList && pList->nExpr > pParse->db->aLimit[SQLITE_LIMIT_FUNCTION_ARG] ){

  98144.     sqlite3ErrorMsg(pParse, "too many arguments on function %T", pToken);

  98145.   }

  98146.   pNew->x.pList = pList;

  98147.   ExprSetProperty(pNew, EP_HasFunc);

  98148.   assert( !ExprHasProperty(pNew, EP_xIsSelect) );

  98149.   sqlite3ExprSetHeightAndFlags(pParse, pNew);

  98150.   if( eDistinct==SF_Distinct ) ExprSetProperty(pNew, EP_Distinct);

  98151.   return pNew;

  98152. }

  98153. 

  98154. /*

  98155. ** Assign a variable number to an expression that encodes a wildcard

  98156. ** in the original SQL statement.  

  98157. **

  98158. ** Wildcards consisting of a single "?" are assigned the next sequential

  98159. ** variable number.

  98160. **

  98161. ** Wildcards of the form "?nnn" are assigned the number "nnn".  We make

  98162. ** sure "nnn" is not too big to avoid a denial of service attack when

  98163. ** the SQL statement comes from an external source.

  98164. **

  98165. ** Wildcards of the form ":aaa", "@aaa", or "$aaa" are assigned the same number

  98166. ** as the previous instance of the same wildcard.  Or if this is the first

  98167. ** instance of the wildcard, the next sequential variable number is

  98168. ** assigned.

  98169. */

  98170. SQLITE_PRIVATE void sqlite3ExprAssignVarNumber(Parse *pParse, Expr *pExpr, u32 n){

  98171.   sqlite3 *db = pParse->db;

  98172.   const char *z;

  98173.   ynVar x;

  98174. 

  98175.   if( pExpr==0 ) return;

  98176.   assert( !ExprHasProperty(pExpr, EP_IntValue|EP_Reduced|EP_TokenOnly) );

  98177.   z = pExpr->u.zToken;

  98178.   assert( z!=0 );

  98179.   assert( z[0]!=0 );

  98180.   assert( n==(u32)sqlite3Strlen30(z) );

  98181.   if( z[1]==0 ){

  98182.     /* Wildcard of the form "?".  Assign the next variable number */

  98183.     assert( z[0]=='?' );

  98184.     x = (ynVar)(++pParse->nVar);

  98185.   }else{

  98186.     int doAdd = 0;

  98187.     if( z[0]=='?' ){

  98188.       /* Wildcard of the form "?nnn".  Convert "nnn" to an integer and

  98189.       ** use it as the variable number */

  98190.       i64 i;

  98191.       int bOk;

  98192.       if( n==2 ){ /*OPTIMIZATION-IF-TRUE*/

  98193.         i = z[1]-'0';  /* The common case of ?N for a single digit N */

  98194.         bOk = 1;

  98195.       }else{

  98196.         bOk = 0==sqlite3Atoi64(&z[1], &i, n-1, SQLITE_UTF8);

  98197.       }

  98198.       testcase( i==0 );

  98199.       testcase( i==1 );

  98200.       testcase( i==db->aLimit[SQLITE_LIMIT_VARIABLE_NUMBER]-1 );

  98201.       testcase( i==db->aLimit[SQLITE_LIMIT_VARIABLE_NUMBER] );

  98202.       if( bOk==0 || i<1 || i>db->aLimit[SQLITE_LIMIT_VARIABLE_NUMBER] ){

  98203.         sqlite3ErrorMsg(pParse, "variable number must be between ?1 and ?%d",

  98204.             db->aLimit[SQLITE_LIMIT_VARIABLE_NUMBER]);

  98205.         return;

  98206.       }

  98207.       x = (ynVar)i;

  98208.       if( x>pParse->nVar ){

  98209.         pParse->nVar = (int)x;

  98210.         doAdd = 1;

  98211.       }else if( sqlite3VListNumToName(pParse->pVList, x)==0 ){

  98212.         doAdd = 1;

  98213.       }

  98214.     }else{

  98215.       /* Wildcards like ":aaa", "$aaa" or "@aaa".  Reuse the same variable

  98216.       ** number as the prior appearance of the same name, or if the name

  98217.       ** has never appeared before, reuse the same variable number

  98218.       */

  98219.       x = (ynVar)sqlite3VListNameToNum(pParse->pVList, z, n);

  98220.       if( x==0 ){

  98221.         x = (ynVar)(++pParse->nVar);

  98222.         doAdd = 1;

  98223.       }

  98224.     }

  98225.     if( doAdd ){

  98226.       pParse->pVList = sqlite3VListAdd(db, pParse->pVList, z, n, x);

  98227.     }

  98228.   }

  98229.   pExpr->iColumn = x;

  98230.   if( x>db->aLimit[SQLITE_LIMIT_VARIABLE_NUMBER] ){

  98231.     sqlite3ErrorMsg(pParse, "too many SQL variables");

  98232.   }

  98233. }

  98234. 

  98235. /*

  98236. ** Recursively delete an expression tree.

  98237. */

  98238. static SQLITE_NOINLINE void sqlite3ExprDeleteNN(sqlite3 *db, Expr *p){

  98239.   assert( p!=0 );

  98240.   /* Sanity check: Assert that the IntValue is non-negative if it exists */

  98241.   assert( !ExprHasProperty(p, EP_IntValue) || p->u.iValue>=0 );

  98242. 

  98243.   assert( !ExprHasProperty(p, EP_WinFunc) || p->y.pWin!=0 || db->mallocFailed );

  98244.   assert( p->op!=TK_FUNCTION || ExprHasProperty(p, EP_TokenOnly|EP_Reduced)

  98245.           || p->y.pWin==0 || ExprHasProperty(p, EP_WinFunc) );

  98246. #ifdef SQLITE_DEBUG

  98247.   if( ExprHasProperty(p, EP_Leaf) && !ExprHasProperty(p, EP_TokenOnly) ){

  98248.     assert( p->pLeft==0 );

  98249.     assert( p->pRight==0 );

  98250.     assert( p->x.pSelect==0 );

  98251.   }

  98252. #endif

  98253.   if( !ExprHasProperty(p, (EP_TokenOnly|EP_Leaf)) ){

  98254.     /* The Expr.x union is never used at the same time as Expr.pRight */

  98255.     assert( p->x.pList==0 || p->pRight==0 );

  98256.     if( p->pLeft && p->op!=TK_SELECT_COLUMN ) sqlite3ExprDeleteNN(db, p->pLeft);

  98257.     if( p->pRight ){

  98258.       sqlite3ExprDeleteNN(db, p->pRight);

  98259.     }else if( ExprHasProperty(p, EP_xIsSelect) ){

  98260.       sqlite3SelectDelete(db, p->x.pSelect);

  98261.     }else{

  98262.       sqlite3ExprListDelete(db, p->x.pList);

  98263.     }

  98264.     if( ExprHasProperty(p, EP_WinFunc) ){

  98265.       assert( p->op==TK_FUNCTION );

  98266.       sqlite3WindowDelete(db, p->y.pWin);

  98267.     }

  98268.   }

  98269.   if( ExprHasProperty(p, EP_MemToken) ) sqlite3DbFree(db, p->u.zToken);

  98270.   if( !ExprHasProperty(p, EP_Static) ){

  98271.     sqlite3DbFreeNN(db, p);

  98272.   }

  98273. }

  98274. SQLITE_PRIVATE void sqlite3ExprDelete(sqlite3 *db, Expr *p){

  98275.   if( p ) sqlite3ExprDeleteNN(db, p);

  98276. }

  98277. 

  98278. /* Invoke sqlite3RenameExprUnmap() and sqlite3ExprDelete() on the

  98279. ** expression.

  98280. */

  98281. SQLITE_PRIVATE void sqlite3ExprUnmapAndDelete(Parse *pParse, Expr *p){

  98282.   if( p ){

  98283.     if( IN_RENAME_OBJECT ){

  98284.       sqlite3RenameExprUnmap(pParse, p);

  98285.     }

  98286.     sqlite3ExprDeleteNN(pParse->db, p);

  98287.   }

  98288. }

  98289. 

  98290. /*

  98291. ** Return the number of bytes allocated for the expression structure 

  98292. ** passed as the first argument. This is always one of EXPR_FULLSIZE,

  98293. ** EXPR_REDUCEDSIZE or EXPR_TOKENONLYSIZE.

  98294. */

  98295. static int exprStructSize(Expr *p){

  98296.   if( ExprHasProperty(p, EP_TokenOnly) ) return EXPR_TOKENONLYSIZE;

  98297.   if( ExprHasProperty(p, EP_Reduced) ) return EXPR_REDUCEDSIZE;

  98298.   return EXPR_FULLSIZE;

  98299. }

  98300. 

  98301. /*

  98302. ** Copy the complete content of an Expr node, taking care not to read

  98303. ** past the end of the structure for a reduced-size version of the source

  98304. ** Expr.

  98305. */

  98306. static void exprNodeCopy(Expr *pDest, Expr *pSrc){

  98307.   memset(pDest, 0, sizeof(Expr));

  98308.   memcpy(pDest, pSrc, exprStructSize(pSrc));

  98309. }

  98310. 

  98311. /*

  98312. ** The dupedExpr*Size() routines each return the number of bytes required

  98313. ** to store a copy of an expression or expression tree.  They differ in

  98314. ** how much of the tree is measured.

  98315. **

  98316. **     dupedExprStructSize()     Size of only the Expr structure 

  98317. **     dupedExprNodeSize()       Size of Expr + space for token

  98318. **     dupedExprSize()           Expr + token + subtree components

  98319. **

  98320. ***************************************************************************

  98321. **

  98322. ** The dupedExprStructSize() function returns two values OR-ed together:  

  98323. ** (1) the space required for a copy of the Expr structure only and 

  98324. ** (2) the EP_xxx flags that indicate what the structure size should be.

  98325. ** The return values is always one of:

  98326. **

  98327. **      EXPR_FULLSIZE

  98328. **      EXPR_REDUCEDSIZE   | EP_Reduced

  98329. **      EXPR_TOKENONLYSIZE | EP_TokenOnly

  98330. **

  98331. ** The size of the structure can be found by masking the return value

  98332. ** of this routine with 0xfff.  The flags can be found by masking the

  98333. ** return value with EP_Reduced|EP_TokenOnly.

  98334. **

  98335. ** Note that with flags==EXPRDUP_REDUCE, this routines works on full-size

  98336. ** (unreduced) Expr objects as they or originally constructed by the parser.

  98337. ** During expression analysis, extra information is computed and moved into

  98338. ** later parts of the Expr object and that extra information might get chopped

  98339. ** off if the expression is reduced.  Note also that it does not work to

  98340. ** make an EXPRDUP_REDUCE copy of a reduced expression.  It is only legal

  98341. ** to reduce a pristine expression tree from the parser.  The implementation

  98342. ** of dupedExprStructSize() contain multiple assert() statements that attempt

  98343. ** to enforce this constraint.

  98344. */

  98345. static int dupedExprStructSize(Expr *p, int flags){

  98346.   int nSize;

  98347.   assert( flags==EXPRDUP_REDUCE || flags==0 ); /* Only one flag value allowed */

  98348.   assert( EXPR_FULLSIZE<=0xfff );

  98349.   assert( (0xfff & (EP_Reduced|EP_TokenOnly))==0 );

  98350.   if( 0==flags || p->op==TK_SELECT_COLUMN 

  98351. #ifndef SQLITE_OMIT_WINDOWFUNC

  98352.    || ExprHasProperty(p, EP_WinFunc)

  98353. #endif

  98354.   ){

  98355.     nSize = EXPR_FULLSIZE;

  98356.   }else{

  98357.     assert( !ExprHasProperty(p, EP_TokenOnly|EP_Reduced) );

  98358.     assert( !ExprHasProperty(p, EP_FromJoin) ); 

  98359.     assert( !ExprHasProperty(p, EP_MemToken) );

  98360.     assert( !ExprHasProperty(p, EP_NoReduce) );

  98361.     if( p->pLeft || p->x.pList ){

  98362.       nSize = EXPR_REDUCEDSIZE | EP_Reduced;

  98363.     }else{

  98364.       assert( p->pRight==0 );

  98365.       nSize = EXPR_TOKENONLYSIZE | EP_TokenOnly;

  98366.     }

  98367.   }

  98368.   return nSize;

  98369. }

  98370. 

  98371. /*

  98372. ** This function returns the space in bytes required to store the copy 

  98373. ** of the Expr structure and a copy of the Expr.u.zToken string (if that

  98374. ** string is defined.)

  98375. */

  98376. static int dupedExprNodeSize(Expr *p, int flags){

  98377.   int nByte = dupedExprStructSize(p, flags) & 0xfff;

  98378.   if( !ExprHasProperty(p, EP_IntValue) && p->u.zToken ){

  98379.     nByte += sqlite3Strlen30NN(p->u.zToken)+1;

  98380.   }

  98381.   return ROUND8(nByte);

  98382. }

  98383. 

  98384. /*

  98385. ** Return the number of bytes required to create a duplicate of the 

  98386. ** expression passed as the first argument. The second argument is a

  98387. ** mask containing EXPRDUP_XXX flags.

  98388. **

  98389. ** The value returned includes space to create a copy of the Expr struct

  98390. ** itself and the buffer referred to by Expr.u.zToken, if any.

  98391. **

  98392. ** If the EXPRDUP_REDUCE flag is set, then the return value includes 

  98393. ** space to duplicate all Expr nodes in the tree formed by Expr.pLeft 

  98394. ** and Expr.pRight variables (but not for any structures pointed to or 

  98395. ** descended from the Expr.x.pList or Expr.x.pSelect variables).

  98396. */

  98397. static int dupedExprSize(Expr *p, int flags){

  98398.   int nByte = 0;

  98399.   if( p ){

  98400.     nByte = dupedExprNodeSize(p, flags);

  98401.     if( flags&EXPRDUP_REDUCE ){

  98402.       nByte += dupedExprSize(p->pLeft, flags) + dupedExprSize(p->pRight, flags);

  98403.     }

  98404.   }

  98405.   return nByte;

  98406. }

  98407. 

  98408. /*

  98409. ** This function is similar to sqlite3ExprDup(), except that if pzBuffer 

  98410. ** is not NULL then *pzBuffer is assumed to point to a buffer large enough 

  98411. ** to store the copy of expression p, the copies of p->u.zToken

  98412. ** (if applicable), and the copies of the p->pLeft and p->pRight expressions,

  98413. ** if any. Before returning, *pzBuffer is set to the first byte past the

  98414. ** portion of the buffer copied into by this function.

  98415. */

  98416. static Expr *exprDup(sqlite3 *db, Expr *p, int dupFlags, u8 **pzBuffer){

  98417.   Expr *pNew;           /* Value to return */

  98418.   u8 *zAlloc;           /* Memory space from which to build Expr object */

  98419.   u32 staticFlag;       /* EP_Static if space not obtained from malloc */

  98420. 

  98421.   assert( db!=0 );

  98422.   assert( p );

  98423.   assert( dupFlags==0 || dupFlags==EXPRDUP_REDUCE );

  98424.   assert( pzBuffer==0 || dupFlags==EXPRDUP_REDUCE );

  98425. 

  98426.   /* Figure out where to write the new Expr structure. */

  98427.   if( pzBuffer ){

  98428.     zAlloc = *pzBuffer;

  98429.     staticFlag = EP_Static;

  98430.   }else{

  98431.     zAlloc = sqlite3DbMallocRawNN(db, dupedExprSize(p, dupFlags));

  98432.     staticFlag = 0;

  98433.   }

  98434.   pNew = (Expr *)zAlloc;

  98435. 

  98436.   if( pNew ){

  98437.     /* Set nNewSize to the size allocated for the structure pointed to

  98438.     ** by pNew. This is either EXPR_FULLSIZE, EXPR_REDUCEDSIZE or

  98439.     ** EXPR_TOKENONLYSIZE. nToken is set to the number of bytes consumed

  98440.     ** by the copy of the p->u.zToken string (if any).

  98441.     */

  98442.     const unsigned nStructSize = dupedExprStructSize(p, dupFlags);

  98443.     const int nNewSize = nStructSize & 0xfff;

  98444.     int nToken;

  98445.     if( !ExprHasProperty(p, EP_IntValue) && p->u.zToken ){

  98446.       nToken = sqlite3Strlen30(p->u.zToken) + 1;

  98447.     }else{

  98448.       nToken = 0;

  98449.     }

  98450.     if( dupFlags ){

  98451.       assert( ExprHasProperty(p, EP_Reduced)==0 );

  98452.       memcpy(zAlloc, p, nNewSize);

  98453.     }else{

  98454.       u32 nSize = (u32)exprStructSize(p);

  98455.       memcpy(zAlloc, p, nSize);

  98456.       if( nSize<EXPR_FULLSIZE ){ 

  98457.         memset(&zAlloc[nSize], 0, EXPR_FULLSIZE-nSize);

  98458.       }

  98459.     }

  98460. 

  98461.     /* Set the EP_Reduced, EP_TokenOnly, and EP_Static flags appropriately. */

  98462.     pNew->flags &= ~(EP_Reduced|EP_TokenOnly|EP_Static|EP_MemToken);

  98463.     pNew->flags |= nStructSize & (EP_Reduced|EP_TokenOnly);

  98464.     pNew->flags |= staticFlag;

  98465. 

  98466.     /* Copy the p->u.zToken string, if any. */

  98467.     if( nToken ){

  98468.       char *zToken = pNew->u.zToken = (char*)&zAlloc[nNewSize];

  98469.       memcpy(zToken, p->u.zToken, nToken);

  98470.     }

  98471. 

  98472.     if( 0==((p->flags|pNew->flags) & (EP_TokenOnly|EP_Leaf)) ){

  98473.       /* Fill in the pNew->x.pSelect or pNew->x.pList member. */

  98474.       if( ExprHasProperty(p, EP_xIsSelect) ){

  98475.         pNew->x.pSelect = sqlite3SelectDup(db, p->x.pSelect, dupFlags);

  98476.       }else{

  98477.         pNew->x.pList = sqlite3ExprListDup(db, p->x.pList, dupFlags);

  98478.       }

  98479.     }

  98480. 

  98481.     /* Fill in pNew->pLeft and pNew->pRight. */

  98482.     if( ExprHasProperty(pNew, EP_Reduced|EP_TokenOnly|EP_WinFunc) ){

  98483.       zAlloc += dupedExprNodeSize(p, dupFlags);

  98484.       if( !ExprHasProperty(pNew, EP_TokenOnly|EP_Leaf) ){

  98485.         pNew->pLeft = p->pLeft ?

  98486.                       exprDup(db, p->pLeft, EXPRDUP_REDUCE, &zAlloc) : 0;

  98487.         pNew->pRight = p->pRight ?

  98488.                        exprDup(db, p->pRight, EXPRDUP_REDUCE, &zAlloc) : 0;

  98489.       }

  98490. #ifndef SQLITE_OMIT_WINDOWFUNC

  98491.       if( ExprHasProperty(p, EP_WinFunc) ){

  98492.         pNew->y.pWin = sqlite3WindowDup(db, pNew, p->y.pWin);

  98493.         assert( ExprHasProperty(pNew, EP_WinFunc) );

  98494.       }

  98495. #endif /* SQLITE_OMIT_WINDOWFUNC */

  98496.       if( pzBuffer ){

  98497.         *pzBuffer = zAlloc;

  98498.       }

  98499.     }else{

  98500.       if( !ExprHasProperty(p, EP_TokenOnly|EP_Leaf) ){

  98501.         if( pNew->op==TK_SELECT_COLUMN ){

  98502.           pNew->pLeft = p->pLeft;

  98503.           assert( p->iColumn==0 || p->pRight==0 );

  98504.           assert( p->pRight==0  || p->pRight==p->pLeft );

  98505.         }else{

  98506.           pNew->pLeft = sqlite3ExprDup(db, p->pLeft, 0);

  98507.         }

  98508.         pNew->pRight = sqlite3ExprDup(db, p->pRight, 0);

  98509.       }

  98510.     }

  98511.   }

  98512.   return pNew;

  98513. }

  98514. 

  98515. /*

  98516. ** Create and return a deep copy of the object passed as the second 

  98517. ** argument. If an OOM condition is encountered, NULL is returned

  98518. ** and the db->mallocFailed flag set.

  98519. */

  98520. #ifndef SQLITE_OMIT_CTE

  98521. static With *withDup(sqlite3 *db, With *p){

  98522.   With *pRet = 0;

  98523.   if( p ){

  98524.     sqlite3_int64 nByte = sizeof(*p) + sizeof(p->a[0]) * (p->nCte-1);

  98525.     pRet = sqlite3DbMallocZero(db, nByte);

  98526.     if( pRet ){

  98527.       int i;

  98528.       pRet->nCte = p->nCte;

  98529.       for(i=0; i<p->nCte; i++){

  98530.         pRet->a[i].pSelect = sqlite3SelectDup(db, p->a[i].pSelect, 0);

  98531.         pRet->a[i].pCols = sqlite3ExprListDup(db, p->a[i].pCols, 0);

  98532.         pRet->a[i].zName = sqlite3DbStrDup(db, p->a[i].zName);

  98533.       }

  98534.     }

  98535.   }

  98536.   return pRet;

  98537. }

  98538. #else

  98539. # define withDup(x,y) 0

  98540. #endif

  98541. 

  98542. #ifndef SQLITE_OMIT_WINDOWFUNC

  98543. /*

  98544. ** The gatherSelectWindows() procedure and its helper routine

  98545. ** gatherSelectWindowsCallback() are used to scan all the expressions

  98546. ** an a newly duplicated SELECT statement and gather all of the Window

  98547. ** objects found there, assembling them onto the linked list at Select->pWin.

  98548. */

  98549. static int gatherSelectWindowsCallback(Walker *pWalker, Expr *pExpr){

  98550.   if( pExpr->op==TK_FUNCTION && pExpr->y.pWin!=0 ){

  98551.     assert( ExprHasProperty(pExpr, EP_WinFunc) );

  98552.     pExpr->y.pWin->pNextWin = pWalker->u.pSelect->pWin;

  98553.     pWalker->u.pSelect->pWin = pExpr->y.pWin;

  98554.   }

  98555.   return WRC_Continue;

  98556. }

  98557. static int gatherSelectWindowsSelectCallback(Walker *pWalker, Select *p){

  98558.   return p==pWalker->u.pSelect ? WRC_Continue : WRC_Prune;

  98559. }

  98560. static void gatherSelectWindows(Select *p){

  98561.   Walker w;

  98562.   w.xExprCallback = gatherSelectWindowsCallback;

  98563.   w.xSelectCallback = gatherSelectWindowsSelectCallback;

  98564.   w.xSelectCallback2 = 0;

  98565.   w.pParse = 0;

  98566.   w.u.pSelect = p;

  98567.   sqlite3WalkSelect(&w, p);

  98568. }

  98569. #endif

  98570. 

  98571. 

  98572. /*

  98573. ** The following group of routines make deep copies of expressions,

  98574. ** expression lists, ID lists, and select statements.  The copies can

  98575. ** be deleted (by being passed to their respective ...Delete() routines)

  98576. ** without effecting the originals.

  98577. **

  98578. ** The expression list, ID, and source lists return by sqlite3ExprListDup(),

  98579. ** sqlite3IdListDup(), and sqlite3SrcListDup() can not be further expanded 

  98580. ** by subsequent calls to sqlite*ListAppend() routines.

  98581. **

  98582. ** Any tables that the SrcList might point to are not duplicated.

  98583. **

  98584. ** The flags parameter contains a combination of the EXPRDUP_XXX flags.

  98585. ** If the EXPRDUP_REDUCE flag is set, then the structure returned is a

  98586. ** truncated version of the usual Expr structure that will be stored as

  98587. ** part of the in-memory representation of the database schema.

  98588. */

  98589. SQLITE_PRIVATE Expr *sqlite3ExprDup(sqlite3 *db, Expr *p, int flags){

  98590.   assert( flags==0 || flags==EXPRDUP_REDUCE );

  98591.   return p ? exprDup(db, p, flags, 0) : 0;

  98592. }

  98593. SQLITE_PRIVATE ExprList *sqlite3ExprListDup(sqlite3 *db, ExprList *p, int flags){

  98594.   ExprList *pNew;

  98595.   struct ExprList_item *pItem, *pOldItem;

  98596.   int i;

  98597.   Expr *pPriorSelectCol = 0;

  98598.   assert( db!=0 );

  98599.   if( p==0 ) return 0;

  98600.   pNew = sqlite3DbMallocRawNN(db, sqlite3DbMallocSize(db, p));

  98601.   if( pNew==0 ) return 0;

  98602.   pNew->nExpr = p->nExpr;

  98603.   pItem = pNew->a;

  98604.   pOldItem = p->a;

  98605.   for(i=0; i<p->nExpr; i++, pItem++, pOldItem++){

  98606.     Expr *pOldExpr = pOldItem->pExpr;

  98607.     Expr *pNewExpr;

  98608.     pItem->pExpr = sqlite3ExprDup(db, pOldExpr, flags);

  98609.     if( pOldExpr 

  98610.      && pOldExpr->op==TK_SELECT_COLUMN

  98611.      && (pNewExpr = pItem->pExpr)!=0 

  98612.     ){

  98613.       assert( pNewExpr->iColumn==0 || i>0 );

  98614.       if( pNewExpr->iColumn==0 ){

  98615.         assert( pOldExpr->pLeft==pOldExpr->pRight );

  98616.         pPriorSelectCol = pNewExpr->pLeft = pNewExpr->pRight;

  98617.       }else{

  98618.         assert( i>0 );

  98619.         assert( pItem[-1].pExpr!=0 );

  98620.         assert( pNewExpr->iColumn==pItem[-1].pExpr->iColumn+1 );

  98621.         assert( pPriorSelectCol==pItem[-1].pExpr->pLeft );

  98622.         pNewExpr->pLeft = pPriorSelectCol;

  98623.       }

  98624.     }

  98625.     pItem->zName = sqlite3DbStrDup(db, pOldItem->zName);

  98626.     pItem->zSpan = sqlite3DbStrDup(db, pOldItem->zSpan);

  98627.     pItem->sortOrder = pOldItem->sortOrder;

  98628.     pItem->done = 0;

  98629.     pItem->bSpanIsTab = pOldItem->bSpanIsTab;

  98630.     pItem->bSorterRef = pOldItem->bSorterRef;

  98631.     pItem->u = pOldItem->u;

  98632.   }

  98633.   return pNew;

  98634. }

  98635. 

  98636. /*

  98637. ** If cursors, triggers, views and subqueries are all omitted from

  98638. ** the build, then none of the following routines, except for 

  98639. ** sqlite3SelectDup(), can be called. sqlite3SelectDup() is sometimes

  98640. ** called with a NULL argument.

  98641. */

  98642. #if !defined(SQLITE_OMIT_VIEW) || !defined(SQLITE_OMIT_TRIGGER) \

  98643.  || !defined(SQLITE_OMIT_SUBQUERY)

  98644. SQLITE_PRIVATE SrcList *sqlite3SrcListDup(sqlite3 *db, SrcList *p, int flags){

  98645.   SrcList *pNew;

  98646.   int i;

  98647.   int nByte;

  98648.   assert( db!=0 );

  98649.   if( p==0 ) return 0;

  98650.   nByte = sizeof(*p) + (p->nSrc>0 ? sizeof(p->a[0]) * (p->nSrc-1) : 0);

  98651.   pNew = sqlite3DbMallocRawNN(db, nByte );

  98652.   if( pNew==0 ) return 0;

  98653.   pNew->nSrc = pNew->nAlloc = p->nSrc;

  98654.   for(i=0; i<p->nSrc; i++){

  98655.     struct SrcList_item *pNewItem = &pNew->a[i];

  98656.     struct SrcList_item *pOldItem = &p->a[i];

  98657.     Table *pTab;

  98658.     pNewItem->pSchema = pOldItem->pSchema;

  98659.     pNewItem->zDatabase = sqlite3DbStrDup(db, pOldItem->zDatabase);

  98660.     pNewItem->zName = sqlite3DbStrDup(db, pOldItem->zName);

  98661.     pNewItem->zAlias = sqlite3DbStrDup(db, pOldItem->zAlias);

  98662.     pNewItem->fg = pOldItem->fg;

  98663.     pNewItem->iCursor = pOldItem->iCursor;

  98664.     pNewItem->addrFillSub = pOldItem->addrFillSub;

  98665.     pNewItem->regReturn = pOldItem->regReturn;

  98666.     if( pNewItem->fg.isIndexedBy ){

  98667.       pNewItem->u1.zIndexedBy = sqlite3DbStrDup(db, pOldItem->u1.zIndexedBy);

  98668.     }

  98669.     pNewItem->pIBIndex = pOldItem->pIBIndex;

  98670.     if( pNewItem->fg.isTabFunc ){

  98671.       pNewItem->u1.pFuncArg = 

  98672.           sqlite3ExprListDup(db, pOldItem->u1.pFuncArg, flags);

  98673.     }

  98674.     pTab = pNewItem->pTab = pOldItem->pTab;

  98675.     if( pTab ){

  98676.       pTab->nTabRef++;

  98677.     }

  98678.     pNewItem->pSelect = sqlite3SelectDup(db, pOldItem->pSelect, flags);

  98679.     pNewItem->pOn = sqlite3ExprDup(db, pOldItem->pOn, flags);

  98680.     pNewItem->pUsing = sqlite3IdListDup(db, pOldItem->pUsing);

  98681.     pNewItem->colUsed = pOldItem->colUsed;

  98682.   }

  98683.   return pNew;

  98684. }

  98685. SQLITE_PRIVATE IdList *sqlite3IdListDup(sqlite3 *db, IdList *p){

  98686.   IdList *pNew;

  98687.   int i;

  98688.   assert( db!=0 );

  98689.   if( p==0 ) return 0;

  98690.   pNew = sqlite3DbMallocRawNN(db, sizeof(*pNew) );

  98691.   if( pNew==0 ) return 0;

  98692.   pNew->nId = p->nId;

  98693.   pNew->a = sqlite3DbMallocRawNN(db, p->nId*sizeof(p->a[0]) );

  98694.   if( pNew->a==0 ){

  98695.     sqlite3DbFreeNN(db, pNew);

  98696.     return 0;

  98697.   }

  98698.   /* Note that because the size of the allocation for p->a[] is not

  98699.   ** necessarily a power of two, sqlite3IdListAppend() may not be called

  98700.   ** on the duplicate created by this function. */

  98701.   for(i=0; i<p->nId; i++){

  98702.     struct IdList_item *pNewItem = &pNew->a[i];

  98703.     struct IdList_item *pOldItem = &p->a[i];

  98704.     pNewItem->zName = sqlite3DbStrDup(db, pOldItem->zName);

  98705.     pNewItem->idx = pOldItem->idx;

  98706.   }

  98707.   return pNew;

  98708. }

  98709. SQLITE_PRIVATE Select *sqlite3SelectDup(sqlite3 *db, Select *pDup, int flags){

  98710.   Select *pRet = 0;

  98711.   Select *pNext = 0;

  98712.   Select **pp = &pRet;

  98713.   Select *p;

  98714. 

  98715.   assert( db!=0 );

  98716.   for(p=pDup; p; p=p->pPrior){

  98717.     Select *pNew = sqlite3DbMallocRawNN(db, sizeof(*p) );

  98718.     if( pNew==0 ) break;

  98719.     pNew->pEList = sqlite3ExprListDup(db, p->pEList, flags);

  98720.     pNew->pSrc = sqlite3SrcListDup(db, p->pSrc, flags);

  98721.     pNew->pWhere = sqlite3ExprDup(db, p->pWhere, flags);

  98722.     pNew->pGroupBy = sqlite3ExprListDup(db, p->pGroupBy, flags);

  98723.     pNew->pHaving = sqlite3ExprDup(db, p->pHaving, flags);

  98724.     pNew->pOrderBy = sqlite3ExprListDup(db, p->pOrderBy, flags);

  98725.     pNew->op = p->op;

  98726.     pNew->pNext = pNext;

  98727.     pNew->pPrior = 0;

  98728.     pNew->pLimit = sqlite3ExprDup(db, p->pLimit, flags);

  98729.     pNew->iLimit = 0;

  98730.     pNew->iOffset = 0;

  98731.     pNew->selFlags = p->selFlags & ~SF_UsesEphemeral;

  98732.     pNew->addrOpenEphm[0] = -1;

  98733.     pNew->addrOpenEphm[1] = -1;

  98734.     pNew->nSelectRow = p->nSelectRow;

  98735.     pNew->pWith = withDup(db, p->pWith);

  98736. #ifndef SQLITE_OMIT_WINDOWFUNC

  98737.     pNew->pWin = 0;

  98738.     pNew->pWinDefn = sqlite3WindowListDup(db, p->pWinDefn);

  98739.     if( p->pWin ) gatherSelectWindows(pNew);

  98740. #endif

  98741.     pNew->selId = p->selId;

  98742.     *pp = pNew;

  98743.     pp = &pNew->pPrior;

  98744.     pNext = pNew;

  98745.   }

  98746. 

  98747.   return pRet;

  98748. }

  98749. #else

  98750. SQLITE_PRIVATE Select *sqlite3SelectDup(sqlite3 *db, Select *p, int flags){

  98751.   assert( p==0 );

  98752.   return 0;

  98753. }

  98754. #endif

  98755. 

  98756. 

  98757. /*

  98758. ** Add a new element to the end of an expression list.  If pList is

  98759. ** initially NULL, then create a new expression list.

  98760. **

  98761. ** The pList argument must be either NULL or a pointer to an ExprList

  98762. ** obtained from a prior call to sqlite3ExprListAppend().  This routine

  98763. ** may not be used with an ExprList obtained from sqlite3ExprListDup().

  98764. ** Reason:  This routine assumes that the number of slots in pList->a[]

  98765. ** is a power of two.  That is true for sqlite3ExprListAppend() returns

  98766. ** but is not necessarily true from the return value of sqlite3ExprListDup().

  98767. **

  98768. ** If a memory allocation error occurs, the entire list is freed and

  98769. ** NULL is returned.  If non-NULL is returned, then it is guaranteed

  98770. ** that the new entry was successfully appended.

  98771. */

  98772. SQLITE_PRIVATE ExprList *sqlite3ExprListAppend(

  98773.   Parse *pParse,          /* Parsing context */

  98774.   ExprList *pList,        /* List to which to append. Might be NULL */

  98775.   Expr *pExpr             /* Expression to be appended. Might be NULL */

  98776. ){

  98777.   struct ExprList_item *pItem;

  98778.   sqlite3 *db = pParse->db;

  98779.   assert( db!=0 );

  98780.   if( pList==0 ){

  98781.     pList = sqlite3DbMallocRawNN(db, sizeof(ExprList) );

  98782.     if( pList==0 ){

  98783.       goto no_mem;

  98784.     }

  98785.     pList->nExpr = 0;

  98786.   }else if( (pList->nExpr & (pList->nExpr-1))==0 ){

  98787.     ExprList *pNew;

  98788.     pNew = sqlite3DbRealloc(db, pList, 

  98789.          sizeof(*pList)+(2*(sqlite3_int64)pList->nExpr-1)*sizeof(pList->a[0]));

  98790.     if( pNew==0 ){

  98791.       goto no_mem;

  98792.     }

  98793.     pList = pNew;

  98794.   }

  98795.   pItem = &pList->a[pList->nExpr++];

  98796.   assert( offsetof(struct ExprList_item,zName)==sizeof(pItem->pExpr) );

  98797.   assert( offsetof(struct ExprList_item,pExpr)==0 );

  98798.   memset(&pItem->zName,0,sizeof(*pItem)-offsetof(struct ExprList_item,zName));

  98799.   pItem->pExpr = pExpr;

  98800.   return pList;

  98801. 

  98802. no_mem:     

  98803.   /* Avoid leaking memory if malloc has failed. */

  98804.   sqlite3ExprDelete(db, pExpr);

  98805.   sqlite3ExprListDelete(db, pList);

  98806.   return 0;

  98807. }

  98808. 

  98809. /*

  98810. ** pColumns and pExpr form a vector assignment which is part of the SET

  98811. ** clause of an UPDATE statement.  Like this:

  98812. **

  98813. **        (a,b,c) = (expr1,expr2,expr3)

  98814. ** Or:    (a,b,c) = (SELECT x,y,z FROM ....)

  98815. **

  98816. ** For each term of the vector assignment, append new entries to the

  98817. ** expression list pList.  In the case of a subquery on the RHS, append

  98818. ** TK_SELECT_COLUMN expressions.

  98819. */

  98820. SQLITE_PRIVATE ExprList *sqlite3ExprListAppendVector(

  98821.   Parse *pParse,         /* Parsing context */

  98822.   ExprList *pList,       /* List to which to append. Might be NULL */

  98823.   IdList *pColumns,      /* List of names of LHS of the assignment */

  98824.   Expr *pExpr            /* Vector expression to be appended. Might be NULL */

  98825. ){

  98826.   sqlite3 *db = pParse->db;

  98827.   int n;

  98828.   int i;

  98829.   int iFirst = pList ? pList->nExpr : 0;

  98830.   /* pColumns can only be NULL due to an OOM but an OOM will cause an

  98831.   ** exit prior to this routine being invoked */

  98832.   if( NEVER(pColumns==0) ) goto vector_append_error;

  98833.   if( pExpr==0 ) goto vector_append_error;

  98834. 

  98835.   /* If the RHS is a vector, then we can immediately check to see that 

  98836.   ** the size of the RHS and LHS match.  But if the RHS is a SELECT, 

  98837.   ** wildcards ("*") in the result set of the SELECT must be expanded before

  98838.   ** we can do the size check, so defer the size check until code generation.

  98839.   */

  98840.   if( pExpr->op!=TK_SELECT && pColumns->nId!=(n=sqlite3ExprVectorSize(pExpr)) ){

  98841.     sqlite3ErrorMsg(pParse, "%d columns assigned %d values",

  98842.                     pColumns->nId, n);

  98843.     goto vector_append_error;

  98844.   }

  98845. 

  98846.   for(i=0; i<pColumns->nId; i++){

  98847.     Expr *pSubExpr = sqlite3ExprForVectorField(pParse, pExpr, i);

  98848.     pList = sqlite3ExprListAppend(pParse, pList, pSubExpr);

  98849.     if( pList ){

  98850.       assert( pList->nExpr==iFirst+i+1 );

  98851.       pList->a[pList->nExpr-1].zName = pColumns->a[i].zName;

  98852.       pColumns->a[i].zName = 0;

  98853.     }

  98854.   }

  98855. 

  98856.   if( !db->mallocFailed && pExpr->op==TK_SELECT && ALWAYS(pList!=0) ){

  98857.     Expr *pFirst = pList->a[iFirst].pExpr;

  98858.     assert( pFirst!=0 );

  98859.     assert( pFirst->op==TK_SELECT_COLUMN );

  98860.      

  98861.     /* Store the SELECT statement in pRight so it will be deleted when

  98862.     ** sqlite3ExprListDelete() is called */

  98863.     pFirst->pRight = pExpr;

  98864.     pExpr = 0;

  98865. 

  98866.     /* Remember the size of the LHS in iTable so that we can check that

  98867.     ** the RHS and LHS sizes match during code generation. */

  98868.     pFirst->iTable = pColumns->nId;

  98869.   }

  98870. 

  98871. vector_append_error:

  98872.   sqlite3ExprUnmapAndDelete(pParse, pExpr);

  98873.   sqlite3IdListDelete(db, pColumns);

  98874.   return pList;

  98875. }

  98876. 

  98877. /*

  98878. ** Set the sort order for the last element on the given ExprList.

  98879. */

  98880. SQLITE_PRIVATE void sqlite3ExprListSetSortOrder(ExprList *p, int iSortOrder){

  98881.   if( p==0 ) return;

  98882.   assert( SQLITE_SO_UNDEFINED<0 && SQLITE_SO_ASC>=0 && SQLITE_SO_DESC>0 );

  98883.   assert( p->nExpr>0 );

  98884.   if( iSortOrder<0 ){

  98885.     assert( p->a[p->nExpr-1].sortOrder==SQLITE_SO_ASC );

  98886.     return;

  98887.   }

  98888.   p->a[p->nExpr-1].sortOrder = (u8)iSortOrder;

  98889. }

  98890. 

  98891. /*

  98892. ** Set the ExprList.a[].zName element of the most recently added item

  98893. ** on the expression list.

  98894. **

  98895. ** pList might be NULL following an OOM error.  But pName should never be

  98896. ** NULL.  If a memory allocation fails, the pParse->db->mallocFailed flag

  98897. ** is set.

  98898. */

  98899. SQLITE_PRIVATE void sqlite3ExprListSetName(

  98900.   Parse *pParse,          /* Parsing context */

  98901.   ExprList *pList,        /* List to which to add the span. */

  98902.   Token *pName,           /* Name to be added */

  98903.   int dequote             /* True to cause the name to be dequoted */

  98904. ){

  98905.   assert( pList!=0 || pParse->db->mallocFailed!=0 );

  98906.   if( pList ){

  98907.     struct ExprList_item *pItem;

  98908.     assert( pList->nExpr>0 );

  98909.     pItem = &pList->a[pList->nExpr-1];

  98910.     assert( pItem->zName==0 );

  98911.     pItem->zName = sqlite3DbStrNDup(pParse->db, pName->z, pName->n);

  98912.     if( dequote ) sqlite3Dequote(pItem->zName);

  98913.     if( IN_RENAME_OBJECT ){

  98914.       sqlite3RenameTokenMap(pParse, (void*)pItem->zName, pName);

  98915.     }

  98916.   }

  98917. }

  98918. 

  98919. /*

  98920. ** Set the ExprList.a[].zSpan element of the most recently added item

  98921. ** on the expression list.

  98922. **

  98923. ** pList might be NULL following an OOM error.  But pSpan should never be

  98924. ** NULL.  If a memory allocation fails, the pParse->db->mallocFailed flag

  98925. ** is set.

  98926. */

  98927. SQLITE_PRIVATE void sqlite3ExprListSetSpan(

  98928.   Parse *pParse,          /* Parsing context */

  98929.   ExprList *pList,        /* List to which to add the span. */

  98930.   const char *zStart,     /* Start of the span */

  98931.   const char *zEnd        /* End of the span */

  98932. ){

  98933.   sqlite3 *db = pParse->db;

  98934.   assert( pList!=0 || db->mallocFailed!=0 );

  98935.   if( pList ){

  98936.     struct ExprList_item *pItem = &pList->a[pList->nExpr-1];

  98937.     assert( pList->nExpr>0 );

  98938.     sqlite3DbFree(db, pItem->zSpan);

  98939.     pItem->zSpan = sqlite3DbSpanDup(db, zStart, zEnd);

  98940.   }

  98941. }

  98942. 

  98943. /*

  98944. ** If the expression list pEList contains more than iLimit elements,

  98945. ** leave an error message in pParse.

  98946. */

  98947. SQLITE_PRIVATE void sqlite3ExprListCheckLength(

  98948.   Parse *pParse,

  98949.   ExprList *pEList,

  98950.   const char *zObject

  98951. ){

  98952.   int mx = pParse->db->aLimit[SQLITE_LIMIT_COLUMN];

  98953.   testcase( pEList && pEList->nExpr==mx );

  98954.   testcase( pEList && pEList->nExpr==mx+1 );

  98955.   if( pEList && pEList->nExpr>mx ){

  98956.     sqlite3ErrorMsg(pParse, "too many columns in %s", zObject);

  98957.   }

  98958. }

  98959. 

  98960. /*

  98961. ** Delete an entire expression list.

  98962. */

  98963. static SQLITE_NOINLINE void exprListDeleteNN(sqlite3 *db, ExprList *pList){

  98964.   int i = pList->nExpr;

  98965.   struct ExprList_item *pItem =  pList->a;

  98966.   assert( pList->nExpr>0 );

  98967.   do{

  98968.     sqlite3ExprDelete(db, pItem->pExpr);

  98969.     sqlite3DbFree(db, pItem->zName);

  98970.     sqlite3DbFree(db, pItem->zSpan);

  98971.     pItem++;

  98972.   }while( --i>0 );

  98973.   sqlite3DbFreeNN(db, pList);

  98974. }

  98975. SQLITE_PRIVATE void sqlite3ExprListDelete(sqlite3 *db, ExprList *pList){

  98976.   if( pList ) exprListDeleteNN(db, pList);

  98977. }

  98978. 

  98979. /*

  98980. ** Return the bitwise-OR of all Expr.flags fields in the given

  98981. ** ExprList.

  98982. */

  98983. SQLITE_PRIVATE u32 sqlite3ExprListFlags(const ExprList *pList){

  98984.   int i;

  98985.   u32 m = 0;

  98986.   assert( pList!=0 );

  98987.   for(i=0; i<pList->nExpr; i++){

  98988.      Expr *pExpr = pList->a[i].pExpr;

  98989.      assert( pExpr!=0 );

  98990.      m |= pExpr->flags;

  98991.   }

  98992.   return m;

  98993. }

  98994. 

  98995. /*

  98996. ** This is a SELECT-node callback for the expression walker that

  98997. ** always "fails".  By "fail" in this case, we mean set

  98998. ** pWalker->eCode to zero and abort.

  98999. **

  99000. ** This callback is used by multiple expression walkers.

  99001. */

  99002. SQLITE_PRIVATE int sqlite3SelectWalkFail(Walker *pWalker, Select *NotUsed){

  99003.   UNUSED_PARAMETER(NotUsed);

  99004.   pWalker->eCode = 0;

  99005.   return WRC_Abort;

  99006. }

  99007. 

  99008. /*

  99009. ** If the input expression is an ID with the name "true" or "false"

  99010. ** then convert it into an TK_TRUEFALSE term.  Return non-zero if

  99011. ** the conversion happened, and zero if the expression is unaltered.

  99012. */

  99013. SQLITE_PRIVATE int sqlite3ExprIdToTrueFalse(Expr *pExpr){

  99014.   assert( pExpr->op==TK_ID || pExpr->op==TK_STRING );

  99015.   if( !ExprHasProperty(pExpr, EP_Quoted)

  99016.    && (sqlite3StrICmp(pExpr->u.zToken, "true")==0

  99017.        || sqlite3StrICmp(pExpr->u.zToken, "false")==0)

  99018.   ){

  99019.     pExpr->op = TK_TRUEFALSE;

  99020.     ExprSetProperty(pExpr, pExpr->u.zToken[4]==0 ? EP_IsTrue : EP_IsFalse);

  99021.     return 1;

  99022.   }

  99023.   return 0;

  99024. }

  99025. 

  99026. /*

  99027. ** The argument must be a TK_TRUEFALSE Expr node.  Return 1 if it is TRUE

  99028. ** and 0 if it is FALSE.

  99029. */

  99030. SQLITE_PRIVATE int sqlite3ExprTruthValue(const Expr *pExpr){

  99031.   pExpr = sqlite3ExprSkipCollate((Expr*)pExpr);

  99032.   assert( pExpr->op==TK_TRUEFALSE );

  99033.   assert( sqlite3StrICmp(pExpr->u.zToken,"true")==0

  99034.        || sqlite3StrICmp(pExpr->u.zToken,"false")==0 );

  99035.   return pExpr->u.zToken[4]==0;

  99036. }

  99037. 

  99038. /*

  99039. ** If pExpr is an AND or OR expression, try to simplify it by eliminating

  99040. ** terms that are always true or false.  Return the simplified expression.

  99041. ** Or return the original expression if no simplification is possible.

  99042. **

  99043. ** Examples:

  99044. **

  99045. **     (x<10) AND true                =>   (x<10)

  99046. **     (x<10) AND false               =>   false

  99047. **     (x<10) AND (y=22 OR false)     =>   (x<10) AND (y=22)

  99048. **     (x<10) AND (y=22 OR true)      =>   (x<10)

  99049. **     (y=22) OR true                 =>   true

  99050. */

  99051. SQLITE_PRIVATE Expr *sqlite3ExprSimplifiedAndOr(Expr *pExpr){

  99052.   assert( pExpr!=0 );

  99053.   if( pExpr->op==TK_AND || pExpr->op==TK_OR ){

  99054.     Expr *pRight = sqlite3ExprSimplifiedAndOr(pExpr->pRight);

  99055.     Expr *pLeft = sqlite3ExprSimplifiedAndOr(pExpr->pLeft);

  99056.     if( ExprAlwaysTrue(pLeft) || ExprAlwaysFalse(pRight) ){

  99057.       pExpr = pExpr->op==TK_AND ? pRight : pLeft;

  99058.     }else if( ExprAlwaysTrue(pRight) || ExprAlwaysFalse(pLeft) ){

  99059.       pExpr = pExpr->op==TK_AND ? pLeft : pRight;

  99060.     }

  99061.   }

  99062.   return pExpr;

  99063. }

  99064. 

  99065. 

  99066. /*

  99067. ** These routines are Walker callbacks used to check expressions to

  99068. ** see if they are "constant" for some definition of constant.  The

  99069. ** Walker.eCode value determines the type of "constant" we are looking

  99070. ** for.

  99071. **

  99072. ** These callback routines are used to implement the following:

  99073. **

  99074. **     sqlite3ExprIsConstant()                  pWalker->eCode==1

  99075. **     sqlite3ExprIsConstantNotJoin()           pWalker->eCode==2

  99076. **     sqlite3ExprIsTableConstant()             pWalker->eCode==3

  99077. **     sqlite3ExprIsConstantOrFunction()        pWalker->eCode==4 or 5

  99078. **

  99079. ** In all cases, the callbacks set Walker.eCode=0 and abort if the expression

  99080. ** is found to not be a constant.

  99081. **

  99082. ** The sqlite3ExprIsConstantOrFunction() is used for evaluating expressions

  99083. ** in a CREATE TABLE statement.  The Walker.eCode value is 5 when parsing

  99084. ** an existing schema and 4 when processing a new statement.  A bound

  99085. ** parameter raises an error for new statements, but is silently converted

  99086. ** to NULL for existing schemas.  This allows sqlite_master tables that 

  99087. ** contain a bound parameter because they were generated by older versions

  99088. ** of SQLite to be parsed by newer versions of SQLite without raising a

  99089. ** malformed schema error.

  99090. */

  99091. static int exprNodeIsConstant(Walker *pWalker, Expr *pExpr){

  99092. 

  99093.   /* If pWalker->eCode is 2 then any term of the expression that comes from

  99094.   ** the ON or USING clauses of a left join disqualifies the expression

  99095.   ** from being considered constant. */

  99096.   if( pWalker->eCode==2 && ExprHasProperty(pExpr, EP_FromJoin) ){

  99097.     pWalker->eCode = 0;

  99098.     return WRC_Abort;

  99099.   }

  99100. 

  99101.   switch( pExpr->op ){

  99102.     /* Consider functions to be constant if all their arguments are constant

  99103.     ** and either pWalker->eCode==4 or 5 or the function has the

  99104.     ** SQLITE_FUNC_CONST flag. */

  99105.     case TK_FUNCTION:

  99106.       if( pWalker->eCode>=4 || ExprHasProperty(pExpr,EP_ConstFunc) ){

  99107.         return WRC_Continue;

  99108.       }else{

  99109.         pWalker->eCode = 0;

  99110.         return WRC_Abort;

  99111.       }

  99112.     case TK_ID:

  99113.       /* Convert "true" or "false" in a DEFAULT clause into the

  99114.       ** appropriate TK_TRUEFALSE operator */

  99115.       if( sqlite3ExprIdToTrueFalse(pExpr) ){

  99116.         return WRC_Prune;

  99117.       }

  99118.       /* Fall thru */

  99119.     case TK_COLUMN:

  99120.     case TK_AGG_FUNCTION:

  99121.     case TK_AGG_COLUMN:

  99122.       testcase( pExpr->op==TK_ID );

  99123.       testcase( pExpr->op==TK_COLUMN );

  99124.       testcase( pExpr->op==TK_AGG_FUNCTION );

  99125.       testcase( pExpr->op==TK_AGG_COLUMN );

  99126.       if( ExprHasProperty(pExpr, EP_FixedCol) && pWalker->eCode!=2 ){

  99127.         return WRC_Continue;

  99128.       }

  99129.       if( pWalker->eCode==3 && pExpr->iTable==pWalker->u.iCur ){

  99130.         return WRC_Continue;

  99131.       }

  99132.       /* Fall through */

  99133.     case TK_IF_NULL_ROW:

  99134.     case TK_REGISTER:

  99135.       testcase( pExpr->op==TK_REGISTER );

  99136.       testcase( pExpr->op==TK_IF_NULL_ROW );

  99137.       pWalker->eCode = 0;

  99138.       return WRC_Abort;

  99139.     case TK_VARIABLE:

  99140.       if( pWalker->eCode==5 ){

  99141.         /* Silently convert bound parameters that appear inside of CREATE

  99142.         ** statements into a NULL when parsing the CREATE statement text out

  99143.         ** of the sqlite_master table */

  99144.         pExpr->op = TK_NULL;

  99145.       }else if( pWalker->eCode==4 ){

  99146.         /* A bound parameter in a CREATE statement that originates from

  99147.         ** sqlite3_prepare() causes an error */

  99148.         pWalker->eCode = 0;

  99149.         return WRC_Abort;

  99150.       }

  99151.       /* Fall through */

  99152.     default:

  99153.       testcase( pExpr->op==TK_SELECT ); /* sqlite3SelectWalkFail() disallows */

  99154.       testcase( pExpr->op==TK_EXISTS ); /* sqlite3SelectWalkFail() disallows */

  99155.       return WRC_Continue;

  99156.   }

  99157. }

  99158. static int exprIsConst(Expr *p, int initFlag, int iCur){

  99159.   Walker w;

  99160.   w.eCode = initFlag;

  99161.   w.xExprCallback = exprNodeIsConstant;

  99162.   w.xSelectCallback = sqlite3SelectWalkFail;

  99163. #ifdef SQLITE_DEBUG

  99164.   w.xSelectCallback2 = sqlite3SelectWalkAssert2;

  99165. #endif

  99166.   w.u.iCur = iCur;

  99167.   sqlite3WalkExpr(&w, p);

  99168.   return w.eCode;

  99169. }

  99170. 

  99171. /*

  99172. ** Walk an expression tree.  Return non-zero if the expression is constant

  99173. ** and 0 if it involves variables or function calls.

  99174. **

  99175. ** For the purposes of this function, a double-quoted string (ex: "abc")

  99176. ** is considered a variable but a single-quoted string (ex: 'abc') is

  99177. ** a constant.

  99178. */

  99179. SQLITE_PRIVATE int sqlite3ExprIsConstant(Expr *p){

  99180.   return exprIsConst(p, 1, 0);

  99181. }

  99182. 

  99183. /*

  99184. ** Walk an expression tree.  Return non-zero if

  99185. **

  99186. **   (1) the expression is constant, and

  99187. **   (2) the expression does originate in the ON or USING clause

  99188. **       of a LEFT JOIN, and

  99189. **   (3) the expression does not contain any EP_FixedCol TK_COLUMN

  99190. **       operands created by the constant propagation optimization.

  99191. **

  99192. ** When this routine returns true, it indicates that the expression

  99193. ** can be added to the pParse->pConstExpr list and evaluated once when

  99194. ** the prepared statement starts up.  See sqlite3ExprCodeAtInit().

  99195. */

  99196. SQLITE_PRIVATE int sqlite3ExprIsConstantNotJoin(Expr *p){

  99197.   return exprIsConst(p, 2, 0);

  99198. }

  99199. 

  99200. /*

  99201. ** Walk an expression tree.  Return non-zero if the expression is constant

  99202. ** for any single row of the table with cursor iCur.  In other words, the

  99203. ** expression must not refer to any non-deterministic function nor any

  99204. ** table other than iCur.

  99205. */

  99206. SQLITE_PRIVATE int sqlite3ExprIsTableConstant(Expr *p, int iCur){

  99207.   return exprIsConst(p, 3, iCur);

  99208. }

  99209. 

  99210. 

  99211. /*

  99212. ** sqlite3WalkExpr() callback used by sqlite3ExprIsConstantOrGroupBy().

  99213. */

  99214. static int exprNodeIsConstantOrGroupBy(Walker *pWalker, Expr *pExpr){

  99215.   ExprList *pGroupBy = pWalker->u.pGroupBy;

  99216.   int i;

  99217. 

  99218.   /* Check if pExpr is identical to any GROUP BY term. If so, consider

  99219.   ** it constant.  */

  99220.   for(i=0; i<pGroupBy->nExpr; i++){

  99221.     Expr *p = pGroupBy->a[i].pExpr;

  99222.     if( sqlite3ExprCompare(0, pExpr, p, -1)<2 ){

  99223.       CollSeq *pColl = sqlite3ExprNNCollSeq(pWalker->pParse, p);

  99224.       if( sqlite3IsBinary(pColl) ){

  99225.         return WRC_Prune;

  99226.       }

  99227.     }

  99228.   }

  99229. 

  99230.   /* Check if pExpr is a sub-select. If so, consider it variable. */

  99231.   if( ExprHasProperty(pExpr, EP_xIsSelect) ){

  99232.     pWalker->eCode = 0;

  99233.     return WRC_Abort;

  99234.   }

  99235. 

  99236.   return exprNodeIsConstant(pWalker, pExpr);

  99237. }

  99238. 

  99239. /*

  99240. ** Walk the expression tree passed as the first argument. Return non-zero

  99241. ** if the expression consists entirely of constants or copies of terms 

  99242. ** in pGroupBy that sort with the BINARY collation sequence.

  99243. **

  99244. ** This routine is used to determine if a term of the HAVING clause can

  99245. ** be promoted into the WHERE clause.  In order for such a promotion to work,

  99246. ** the value of the HAVING clause term must be the same for all members of

  99247. ** a "group".  The requirement that the GROUP BY term must be BINARY

  99248. ** assumes that no other collating sequence will have a finer-grained

  99249. ** grouping than binary.  In other words (A=B COLLATE binary) implies

  99250. ** A=B in every other collating sequence.  The requirement that the

  99251. ** GROUP BY be BINARY is stricter than necessary.  It would also work

  99252. ** to promote HAVING clauses that use the same alternative collating

  99253. ** sequence as the GROUP BY term, but that is much harder to check,

  99254. ** alternative collating sequences are uncommon, and this is only an

  99255. ** optimization, so we take the easy way out and simply require the

  99256. ** GROUP BY to use the BINARY collating sequence.

  99257. */

  99258. SQLITE_PRIVATE int sqlite3ExprIsConstantOrGroupBy(Parse *pParse, Expr *p, ExprList *pGroupBy){

  99259.   Walker w;

  99260.   w.eCode = 1;

  99261.   w.xExprCallback = exprNodeIsConstantOrGroupBy;

  99262.   w.xSelectCallback = 0;

  99263.   w.u.pGroupBy = pGroupBy;

  99264.   w.pParse = pParse;

  99265.   sqlite3WalkExpr(&w, p);

  99266.   return w.eCode;

  99267. }

  99268. 

  99269. /*

  99270. ** Walk an expression tree.  Return non-zero if the expression is constant

  99271. ** or a function call with constant arguments.  Return and 0 if there

  99272. ** are any variables.

  99273. **

  99274. ** For the purposes of this function, a double-quoted string (ex: "abc")

  99275. ** is considered a variable but a single-quoted string (ex: 'abc') is

  99276. ** a constant.

  99277. */

  99278. SQLITE_PRIVATE int sqlite3ExprIsConstantOrFunction(Expr *p, u8 isInit){

  99279.   assert( isInit==0 || isInit==1 );

  99280.   return exprIsConst(p, 4+isInit, 0);

  99281. }

  99282. 

  99283. #ifdef SQLITE_ENABLE_CURSOR_HINTS

  99284. /*

  99285. ** Walk an expression tree.  Return 1 if the expression contains a

  99286. ** subquery of some kind.  Return 0 if there are no subqueries.

  99287. */

  99288. SQLITE_PRIVATE int sqlite3ExprContainsSubquery(Expr *p){

  99289.   Walker w;

  99290.   w.eCode = 1;

  99291.   w.xExprCallback = sqlite3ExprWalkNoop;

  99292.   w.xSelectCallback = sqlite3SelectWalkFail;

  99293. #ifdef SQLITE_DEBUG

  99294.   w.xSelectCallback2 = sqlite3SelectWalkAssert2;

  99295. #endif

  99296.   sqlite3WalkExpr(&w, p);

  99297.   return w.eCode==0;

  99298. }

  99299. #endif

  99300. 

  99301. /*

  99302. ** If the expression p codes a constant integer that is small enough

  99303. ** to fit in a 32-bit integer, return 1 and put the value of the integer

  99304. ** in *pValue.  If the expression is not an integer or if it is too big

  99305. ** to fit in a signed 32-bit integer, return 0 and leave *pValue unchanged.

  99306. */

  99307. SQLITE_PRIVATE int sqlite3ExprIsInteger(Expr *p, int *pValue){

  99308.   int rc = 0;

  99309.   if( NEVER(p==0) ) return 0;  /* Used to only happen following on OOM */

  99310. 

  99311.   /* If an expression is an integer literal that fits in a signed 32-bit

  99312.   ** integer, then the EP_IntValue flag will have already been set */

  99313.   assert( p->op!=TK_INTEGER || (p->flags & EP_IntValue)!=0

  99314.            || sqlite3GetInt32(p->u.zToken, &rc)==0 );

  99315. 

  99316.   if( p->flags & EP_IntValue ){

  99317.     *pValue = p->u.iValue;

  99318.     return 1;

  99319.   }

  99320.   switch( p->op ){

  99321.     case TK_UPLUS: {

  99322.       rc = sqlite3ExprIsInteger(p->pLeft, pValue);

  99323.       break;

  99324.     }

  99325.     case TK_UMINUS: {

  99326.       int v;

  99327.       if( sqlite3ExprIsInteger(p->pLeft, &v) ){

  99328.         assert( v!=(-2147483647-1) );

  99329.         *pValue = -v;

  99330.         rc = 1;

  99331.       }

  99332.       break;

  99333.     }

  99334.     default: break;

  99335.   }

  99336.   return rc;

  99337. }

  99338. 

  99339. /*

  99340. ** Return FALSE if there is no chance that the expression can be NULL.

  99341. **

  99342. ** If the expression might be NULL or if the expression is too complex

  99343. ** to tell return TRUE.  

  99344. **

  99345. ** This routine is used as an optimization, to skip OP_IsNull opcodes

  99346. ** when we know that a value cannot be NULL.  Hence, a false positive

  99347. ** (returning TRUE when in fact the expression can never be NULL) might

  99348. ** be a small performance hit but is otherwise harmless.  On the other

  99349. ** hand, a false negative (returning FALSE when the result could be NULL)

  99350. ** will likely result in an incorrect answer.  So when in doubt, return

  99351. ** TRUE.

  99352. */

  99353. SQLITE_PRIVATE int sqlite3ExprCanBeNull(const Expr *p){

  99354.   u8 op;

  99355.   while( p->op==TK_UPLUS || p->op==TK_UMINUS ){

  99356.     p = p->pLeft;

  99357.   }

  99358.   op = p->op;

  99359.   if( op==TK_REGISTER ) op = p->op2;

  99360.   switch( op ){

  99361.     case TK_INTEGER:

  99362.     case TK_STRING:

  99363.     case TK_FLOAT:

  99364.     case TK_BLOB:

  99365.       return 0;

  99366.     case TK_COLUMN:

  99367.       return ExprHasProperty(p, EP_CanBeNull) ||

  99368.              p->y.pTab==0 ||  /* Reference to column of index on expression */

  99369.              (p->iColumn>=0 && p->y.pTab->aCol[p->iColumn].notNull==0);

  99370.     default:

  99371.       return 1;

  99372.   }

  99373. }

  99374. 

  99375. /*

  99376. ** Return TRUE if the given expression is a constant which would be

  99377. ** unchanged by OP_Affinity with the affinity given in the second

  99378. ** argument.

  99379. **

  99380. ** This routine is used to determine if the OP_Affinity operation

  99381. ** can be omitted.  When in doubt return FALSE.  A false negative

  99382. ** is harmless.  A false positive, however, can result in the wrong

  99383. ** answer.

  99384. */

  99385. SQLITE_PRIVATE int sqlite3ExprNeedsNoAffinityChange(const Expr *p, char aff){

  99386.   u8 op;

  99387.   if( aff==SQLITE_AFF_BLOB ) return 1;

  99388.   while( p->op==TK_UPLUS || p->op==TK_UMINUS ){ p = p->pLeft; }

  99389.   op = p->op;

  99390.   if( op==TK_REGISTER ) op = p->op2;

  99391.   switch( op ){

  99392.     case TK_INTEGER: {

  99393.       return aff==SQLITE_AFF_INTEGER || aff==SQLITE_AFF_NUMERIC;

  99394.     }

  99395.     case TK_FLOAT: {

  99396.       return aff==SQLITE_AFF_REAL || aff==SQLITE_AFF_NUMERIC;

  99397.     }

  99398.     case TK_STRING: {

  99399.       return aff==SQLITE_AFF_TEXT;

  99400.     }

  99401.     case TK_BLOB: {

  99402.       return 1;

  99403.     }

  99404.     case TK_COLUMN: {

  99405.       assert( p->iTable>=0 );  /* p cannot be part of a CHECK constraint */

  99406.       return p->iColumn<0

  99407.           && (aff==SQLITE_AFF_INTEGER || aff==SQLITE_AFF_NUMERIC);

  99408.     }

  99409.     default: {

  99410.       return 0;

  99411.     }

  99412.   }

  99413. }

  99414. 

  99415. /*

  99416. ** Return TRUE if the given string is a row-id column name.

  99417. */

  99418. SQLITE_PRIVATE int sqlite3IsRowid(const char *z){

  99419.   if( sqlite3StrICmp(z, "_ROWID_")==0 ) return 1;

  99420.   if( sqlite3StrICmp(z, "ROWID")==0 ) return 1;

  99421.   if( sqlite3StrICmp(z, "OID")==0 ) return 1;

  99422.   return 0;

  99423. }

  99424. 

  99425. /*

  99426. ** pX is the RHS of an IN operator.  If pX is a SELECT statement 

  99427. ** that can be simplified to a direct table access, then return

  99428. ** a pointer to the SELECT statement.  If pX is not a SELECT statement,

  99429. ** or if the SELECT statement needs to be manifested into a transient

  99430. ** table, then return NULL.

  99431. */

  99432. #ifndef SQLITE_OMIT_SUBQUERY

  99433. static Select *isCandidateForInOpt(Expr *pX){

  99434.   Select *p;

  99435.   SrcList *pSrc;

  99436.   ExprList *pEList;

  99437.   Table *pTab;

  99438.   int i;

  99439.   if( !ExprHasProperty(pX, EP_xIsSelect) ) return 0;  /* Not a subquery */

  99440.   if( ExprHasProperty(pX, EP_VarSelect)  ) return 0;  /* Correlated subq */

  99441.   p = pX->x.pSelect;

  99442.   if( p->pPrior ) return 0;              /* Not a compound SELECT */

  99443.   if( p->selFlags & (SF_Distinct|SF_Aggregate) ){

  99444.     testcase( (p->selFlags & (SF_Distinct|SF_Aggregate))==SF_Distinct );

  99445.     testcase( (p->selFlags & (SF_Distinct|SF_Aggregate))==SF_Aggregate );

  99446.     return 0; /* No DISTINCT keyword and no aggregate functions */

  99447.   }

  99448.   assert( p->pGroupBy==0 );              /* Has no GROUP BY clause */

  99449.   if( p->pLimit ) return 0;              /* Has no LIMIT clause */

  99450.   if( p->pWhere ) return 0;              /* Has no WHERE clause */

  99451.   pSrc = p->pSrc;

  99452.   assert( pSrc!=0 );

  99453.   if( pSrc->nSrc!=1 ) return 0;          /* Single term in FROM clause */

  99454.   if( pSrc->a[0].pSelect ) return 0;     /* FROM is not a subquery or view */

  99455.   pTab = pSrc->a[0].pTab;

  99456.   assert( pTab!=0 );

  99457.   assert( pTab->pSelect==0 );            /* FROM clause is not a view */

  99458.   if( IsVirtual(pTab) ) return 0;        /* FROM clause not a virtual table */

  99459.   pEList = p->pEList;

  99460.   assert( pEList!=0 );

  99461.   /* All SELECT results must be columns. */

  99462.   for(i=0; i<pEList->nExpr; i++){

  99463.     Expr *pRes = pEList->a[i].pExpr;

  99464.     if( pRes->op!=TK_COLUMN ) return 0;

  99465.     assert( pRes->iTable==pSrc->a[0].iCursor );  /* Not a correlated subquery */

  99466.   }

  99467.   return p;

  99468. }

  99469. #endif /* SQLITE_OMIT_SUBQUERY */

  99470. 

  99471. #ifndef SQLITE_OMIT_SUBQUERY

  99472. /*

  99473. ** Generate code that checks the left-most column of index table iCur to see if

  99474. ** it contains any NULL entries.  Cause the register at regHasNull to be set

  99475. ** to a non-NULL value if iCur contains no NULLs.  Cause register regHasNull

  99476. ** to be set to NULL if iCur contains one or more NULL values.

  99477. */

  99478. static void sqlite3SetHasNullFlag(Vdbe *v, int iCur, int regHasNull){

  99479.   int addr1;

  99480.   sqlite3VdbeAddOp2(v, OP_Integer, 0, regHasNull);

  99481.   addr1 = sqlite3VdbeAddOp1(v, OP_Rewind, iCur); VdbeCoverage(v);

  99482.   sqlite3VdbeAddOp3(v, OP_Column, iCur, 0, regHasNull);

  99483.   sqlite3VdbeChangeP5(v, OPFLAG_TYPEOFARG);

  99484.   VdbeComment((v, "first_entry_in(%d)", iCur));

  99485.   sqlite3VdbeJumpHere(v, addr1);

  99486. }

  99487. #endif

  99488. 

  99489. 

  99490. #ifndef SQLITE_OMIT_SUBQUERY

  99491. /*

  99492. ** The argument is an IN operator with a list (not a subquery) on the 

  99493. ** right-hand side.  Return TRUE if that list is constant.

  99494. */

  99495. static int sqlite3InRhsIsConstant(Expr *pIn){

  99496.   Expr *pLHS;

  99497.   int res;

  99498.   assert( !ExprHasProperty(pIn, EP_xIsSelect) );

  99499.   pLHS = pIn->pLeft;

  99500.   pIn->pLeft = 0;

  99501.   res = sqlite3ExprIsConstant(pIn);

  99502.   pIn->pLeft = pLHS;

  99503.   return res;

  99504. }

  99505. #endif

  99506. 

  99507. /*

  99508. ** This function is used by the implementation of the IN (...) operator.

  99509. ** The pX parameter is the expression on the RHS of the IN operator, which

  99510. ** might be either a list of expressions or a subquery.

  99511. **

  99512. ** The job of this routine is to find or create a b-tree object that can

  99513. ** be used either to test for membership in the RHS set or to iterate through

  99514. ** all members of the RHS set, skipping duplicates.

  99515. **

  99516. ** A cursor is opened on the b-tree object that is the RHS of the IN operator

  99517. ** and pX->iTable is set to the index of that cursor.

  99518. **

  99519. ** The returned value of this function indicates the b-tree type, as follows:

  99520. **

  99521. **   IN_INDEX_ROWID      - The cursor was opened on a database table.

  99522. **   IN_INDEX_INDEX_ASC  - The cursor was opened on an ascending index.

  99523. **   IN_INDEX_INDEX_DESC - The cursor was opened on a descending index.

  99524. **   IN_INDEX_EPH        - The cursor was opened on a specially created and

  99525. **                         populated epheremal table.

  99526. **   IN_INDEX_NOOP       - No cursor was allocated.  The IN operator must be

  99527. **                         implemented as a sequence of comparisons.

  99528. **

  99529. ** An existing b-tree might be used if the RHS expression pX is a simple

  99530. ** subquery such as:

  99531. **

  99532. **     SELECT <column1>, <column2>... FROM <table>

  99533. **

  99534. ** If the RHS of the IN operator is a list or a more complex subquery, then

  99535. ** an ephemeral table might need to be generated from the RHS and then

  99536. ** pX->iTable made to point to the ephemeral table instead of an

  99537. ** existing table.

  99538. **

  99539. ** The inFlags parameter must contain, at a minimum, one of the bits

  99540. ** IN_INDEX_MEMBERSHIP or IN_INDEX_LOOP but not both.  If inFlags contains

  99541. ** IN_INDEX_MEMBERSHIP, then the generated table will be used for a fast

  99542. ** membership test.  When the IN_INDEX_LOOP bit is set, the IN index will

  99543. ** be used to loop over all values of the RHS of the IN operator.

  99544. **

  99545. ** When IN_INDEX_LOOP is used (and the b-tree will be used to iterate

  99546. ** through the set members) then the b-tree must not contain duplicates.

  99547. ** An epheremal table will be created unless the selected columns are guaranteed

  99548. ** to be unique - either because it is an INTEGER PRIMARY KEY or due to

  99549. ** a UNIQUE constraint or index.

  99550. **

  99551. ** When IN_INDEX_MEMBERSHIP is used (and the b-tree will be used 

  99552. ** for fast set membership tests) then an epheremal table must 

  99553. ** be used unless <columns> is a single INTEGER PRIMARY KEY column or an 

  99554. ** index can be found with the specified <columns> as its left-most.

  99555. **

  99556. ** If the IN_INDEX_NOOP_OK and IN_INDEX_MEMBERSHIP are both set and

  99557. ** if the RHS of the IN operator is a list (not a subquery) then this

  99558. ** routine might decide that creating an ephemeral b-tree for membership

  99559. ** testing is too expensive and return IN_INDEX_NOOP.  In that case, the

  99560. ** calling routine should implement the IN operator using a sequence

  99561. ** of Eq or Ne comparison operations.

  99562. **

  99563. ** When the b-tree is being used for membership tests, the calling function

  99564. ** might need to know whether or not the RHS side of the IN operator

  99565. ** contains a NULL.  If prRhsHasNull is not a NULL pointer and 

  99566. ** if there is any chance that the (...) might contain a NULL value at

  99567. ** runtime, then a register is allocated and the register number written

  99568. ** to *prRhsHasNull. If there is no chance that the (...) contains a

  99569. ** NULL value, then *prRhsHasNull is left unchanged.

  99570. **

  99571. ** If a register is allocated and its location stored in *prRhsHasNull, then

  99572. ** the value in that register will be NULL if the b-tree contains one or more

  99573. ** NULL values, and it will be some non-NULL value if the b-tree contains no

  99574. ** NULL values.

  99575. **

  99576. ** If the aiMap parameter is not NULL, it must point to an array containing

  99577. ** one element for each column returned by the SELECT statement on the RHS

  99578. ** of the IN(...) operator. The i'th entry of the array is populated with the

  99579. ** offset of the index column that matches the i'th column returned by the

  99580. ** SELECT. For example, if the expression and selected index are:

  99581. **

  99582. **   (?,?,?) IN (SELECT a, b, c FROM t1)

  99583. **   CREATE INDEX i1 ON t1(b, c, a);

  99584. **

  99585. ** then aiMap[] is populated with {2, 0, 1}.

  99586. */

  99587. #ifndef SQLITE_OMIT_SUBQUERY

  99588. SQLITE_PRIVATE int sqlite3FindInIndex(

  99589.   Parse *pParse,             /* Parsing context */

  99590.   Expr *pX,                  /* The right-hand side (RHS) of the IN operator */

  99591.   u32 inFlags,               /* IN_INDEX_LOOP, _MEMBERSHIP, and/or _NOOP_OK */

  99592.   int *prRhsHasNull,         /* Register holding NULL status.  See notes */

  99593.   int *aiMap,                /* Mapping from Index fields to RHS fields */

  99594.   int *piTab                 /* OUT: index to use */

  99595. ){

  99596.   Select *p;                            /* SELECT to the right of IN operator */

  99597.   int eType = 0;                        /* Type of RHS table. IN_INDEX_* */

  99598.   int iTab = pParse->nTab++;            /* Cursor of the RHS table */

  99599.   int mustBeUnique;                     /* True if RHS must be unique */

  99600.   Vdbe *v = sqlite3GetVdbe(pParse);     /* Virtual machine being coded */

  99601. 

  99602.   assert( pX->op==TK_IN );

  99603.   mustBeUnique = (inFlags & IN_INDEX_LOOP)!=0;

  99604. 

  99605.   /* If the RHS of this IN(...) operator is a SELECT, and if it matters 

  99606.   ** whether or not the SELECT result contains NULL values, check whether

  99607.   ** or not NULL is actually possible (it may not be, for example, due 

  99608.   ** to NOT NULL constraints in the schema). If no NULL values are possible,

  99609.   ** set prRhsHasNull to 0 before continuing.  */

  99610.   if( prRhsHasNull && (pX->flags & EP_xIsSelect) ){

  99611.     int i;

  99612.     ExprList *pEList = pX->x.pSelect->pEList;

  99613.     for(i=0; i<pEList->nExpr; i++){

  99614.       if( sqlite3ExprCanBeNull(pEList->a[i].pExpr) ) break;

  99615.     }

  99616.     if( i==pEList->nExpr ){

  99617.       prRhsHasNull = 0;

  99618.     }

  99619.   }

  99620. 

  99621.   /* Check to see if an existing table or index can be used to

  99622.   ** satisfy the query.  This is preferable to generating a new 

  99623.   ** ephemeral table.  */

  99624.   if( pParse->nErr==0 && (p = isCandidateForInOpt(pX))!=0 ){

  99625.     sqlite3 *db = pParse->db;              /* Database connection */

  99626.     Table *pTab;                           /* Table <table>. */

  99627.     i16 iDb;                               /* Database idx for pTab */

  99628.     ExprList *pEList = p->pEList;

  99629.     int nExpr = pEList->nExpr;

  99630. 

  99631.     assert( p->pEList!=0 );             /* Because of isCandidateForInOpt(p) */

  99632.     assert( p->pEList->a[0].pExpr!=0 ); /* Because of isCandidateForInOpt(p) */

  99633.     assert( p->pSrc!=0 );               /* Because of isCandidateForInOpt(p) */

  99634.     pTab = p->pSrc->a[0].pTab;

  99635. 

  99636.     /* Code an OP_Transaction and OP_TableLock for <table>. */

  99637.     iDb = sqlite3SchemaToIndex(db, pTab->pSchema);

  99638.     sqlite3CodeVerifySchema(pParse, iDb);

  99639.     sqlite3TableLock(pParse, iDb, pTab->tnum, 0, pTab->zName);

  99640. 

  99641.     assert(v);  /* sqlite3GetVdbe() has always been previously called */

  99642.     if( nExpr==1 && pEList->a[0].pExpr->iColumn<0 ){

  99643.       /* The "x IN (SELECT rowid FROM table)" case */

  99644.       int iAddr = sqlite3VdbeAddOp0(v, OP_Once);

  99645.       VdbeCoverage(v);

  99646. 

  99647.       sqlite3OpenTable(pParse, iTab, iDb, pTab, OP_OpenRead);

  99648.       eType = IN_INDEX_ROWID;

  99649.       ExplainQueryPlan((pParse, 0,

  99650.             "USING ROWID SEARCH ON TABLE %s FOR IN-OPERATOR",pTab->zName));

  99651.       sqlite3VdbeJumpHere(v, iAddr);

  99652.     }else{

  99653.       Index *pIdx;                         /* Iterator variable */

  99654.       int affinity_ok = 1;

  99655.       int i;

  99656. 

  99657.       /* Check that the affinity that will be used to perform each 

  99658.       ** comparison is the same as the affinity of each column in table

  99659.       ** on the RHS of the IN operator.  If it not, it is not possible to

  99660.       ** use any index of the RHS table.  */

  99661.       for(i=0; i<nExpr && affinity_ok; i++){

  99662.         Expr *pLhs = sqlite3VectorFieldSubexpr(pX->pLeft, i);

  99663.         int iCol = pEList->a[i].pExpr->iColumn;

  99664.         char idxaff = sqlite3TableColumnAffinity(pTab,iCol); /* RHS table */

  99665.         char cmpaff = sqlite3CompareAffinity(pLhs, idxaff);

  99666.         testcase( cmpaff==SQLITE_AFF_BLOB );

  99667.         testcase( cmpaff==SQLITE_AFF_TEXT );

  99668.         switch( cmpaff ){

  99669.           case SQLITE_AFF_BLOB:

  99670.             break;

  99671.           case SQLITE_AFF_TEXT:

  99672.             /* sqlite3CompareAffinity() only returns TEXT if one side or the

  99673.             ** other has no affinity and the other side is TEXT.  Hence,

  99674.             ** the only way for cmpaff to be TEXT is for idxaff to be TEXT

  99675.             ** and for the term on the LHS of the IN to have no affinity. */

  99676.             assert( idxaff==SQLITE_AFF_TEXT );

  99677.             break;

  99678.           default:

  99679.             affinity_ok = sqlite3IsNumericAffinity(idxaff);

  99680.         }

  99681.       }

  99682. 

  99683.       if( affinity_ok ){

  99684.         /* Search for an existing index that will work for this IN operator */

  99685.         for(pIdx=pTab->pIndex; pIdx && eType==0; pIdx=pIdx->pNext){

  99686.           Bitmask colUsed;      /* Columns of the index used */

  99687.           Bitmask mCol;         /* Mask for the current column */

  99688.           if( pIdx->nColumn<nExpr ) continue;

  99689.           if( pIdx->pPartIdxWhere!=0 ) continue;

  99690.           /* Maximum nColumn is BMS-2, not BMS-1, so that we can compute

  99691.           ** BITMASK(nExpr) without overflowing */

  99692.           testcase( pIdx->nColumn==BMS-2 );

  99693.           testcase( pIdx->nColumn==BMS-1 );

  99694.           if( pIdx->nColumn>=BMS-1 ) continue;

  99695.           if( mustBeUnique ){

  99696.             if( pIdx->nKeyCol>nExpr

  99697.              ||(pIdx->nColumn>nExpr && !IsUniqueIndex(pIdx))

  99698.             ){

  99699.               continue;  /* This index is not unique over the IN RHS columns */

  99700.             }

  99701.           }

  99702.   

  99703.           colUsed = 0;   /* Columns of index used so far */

  99704.           for(i=0; i<nExpr; i++){

  99705.             Expr *pLhs = sqlite3VectorFieldSubexpr(pX->pLeft, i);

  99706.             Expr *pRhs = pEList->a[i].pExpr;

  99707.             CollSeq *pReq = sqlite3BinaryCompareCollSeq(pParse, pLhs, pRhs);

  99708.             int j;

  99709.   

  99710.             assert( pReq!=0 || pRhs->iColumn==XN_ROWID || pParse->nErr );

  99711.             for(j=0; j<nExpr; j++){

  99712.               if( pIdx->aiColumn[j]!=pRhs->iColumn ) continue;

  99713.               assert( pIdx->azColl[j] );

  99714.               if( pReq!=0 && sqlite3StrICmp(pReq->zName, pIdx->azColl[j])!=0 ){

  99715.                 continue;

  99716.               }

  99717.               break;

  99718.             }

  99719.             if( j==nExpr ) break;

  99720.             mCol = MASKBIT(j);

  99721.             if( mCol & colUsed ) break; /* Each column used only once */

  99722.             colUsed |= mCol;

  99723.             if( aiMap ) aiMap[i] = j;

  99724.           }

  99725.   

  99726.           assert( i==nExpr || colUsed!=(MASKBIT(nExpr)-1) );

  99727.           if( colUsed==(MASKBIT(nExpr)-1) ){

  99728.             /* If we reach this point, that means the index pIdx is usable */

  99729.             int iAddr = sqlite3VdbeAddOp0(v, OP_Once); VdbeCoverage(v);

  99730.             ExplainQueryPlan((pParse, 0,

  99731.                               "USING INDEX %s FOR IN-OPERATOR",pIdx->zName));

  99732.             sqlite3VdbeAddOp3(v, OP_OpenRead, iTab, pIdx->tnum, iDb);

  99733.             sqlite3VdbeSetP4KeyInfo(pParse, pIdx);

  99734.             VdbeComment((v, "%s", pIdx->zName));

  99735.             assert( IN_INDEX_INDEX_DESC == IN_INDEX_INDEX_ASC+1 );

  99736.             eType = IN_INDEX_INDEX_ASC + pIdx->aSortOrder[0];

  99737.   

  99738.             if( prRhsHasNull ){

  99739. #ifdef SQLITE_ENABLE_COLUMN_USED_MASK

  99740.               i64 mask = (1<<nExpr)-1;

  99741.               sqlite3VdbeAddOp4Dup8(v, OP_ColumnsUsed, 

  99742.                   iTab, 0, 0, (u8*)&mask, P4_INT64);

  99743. #endif

  99744.               *prRhsHasNull = ++pParse->nMem;

  99745.               if( nExpr==1 ){

  99746.                 sqlite3SetHasNullFlag(v, iTab, *prRhsHasNull);

  99747.               }

  99748.             }

  99749.             sqlite3VdbeJumpHere(v, iAddr);

  99750.           }

  99751.         } /* End loop over indexes */

  99752.       } /* End if( affinity_ok ) */

  99753.     } /* End if not an rowid index */

  99754.   } /* End attempt to optimize using an index */

  99755. 

  99756.   /* If no preexisting index is available for the IN clause

  99757.   ** and IN_INDEX_NOOP is an allowed reply

  99758.   ** and the RHS of the IN operator is a list, not a subquery

  99759.   ** and the RHS is not constant or has two or fewer terms,

  99760.   ** then it is not worth creating an ephemeral table to evaluate

  99761.   ** the IN operator so return IN_INDEX_NOOP.

  99762.   */

  99763.   if( eType==0

  99764.    && (inFlags & IN_INDEX_NOOP_OK)

  99765.    && !ExprHasProperty(pX, EP_xIsSelect)

  99766.    && (!sqlite3InRhsIsConstant(pX) || pX->x.pList->nExpr<=2)

  99767.   ){

  99768.     eType = IN_INDEX_NOOP;

  99769.   }

  99770. 

  99771.   if( eType==0 ){

  99772.     /* Could not find an existing table or index to use as the RHS b-tree.

  99773.     ** We will have to generate an ephemeral table to do the job.

  99774.     */

  99775.     u32 savedNQueryLoop = pParse->nQueryLoop;

  99776.     int rMayHaveNull = 0;

  99777.     eType = IN_INDEX_EPH;

  99778.     if( inFlags & IN_INDEX_LOOP ){

  99779.       pParse->nQueryLoop = 0;

  99780.     }else if( prRhsHasNull ){

  99781.       *prRhsHasNull = rMayHaveNull = ++pParse->nMem;

  99782.     }

  99783.     assert( pX->op==TK_IN );

  99784.     sqlite3CodeRhsOfIN(pParse, pX, iTab);

  99785.     if( rMayHaveNull ){

  99786.       sqlite3SetHasNullFlag(v, iTab, rMayHaveNull);

  99787.     }

  99788.     pParse->nQueryLoop = savedNQueryLoop;

  99789.   }

  99790. 

  99791.   if( aiMap && eType!=IN_INDEX_INDEX_ASC && eType!=IN_INDEX_INDEX_DESC ){

  99792.     int i, n;

  99793.     n = sqlite3ExprVectorSize(pX->pLeft);

  99794.     for(i=0; i<n; i++) aiMap[i] = i;

  99795.   }

  99796.   *piTab = iTab;

  99797.   return eType;

  99798. }

  99799. #endif

  99800. 

  99801. #ifndef SQLITE_OMIT_SUBQUERY

  99802. /*

  99803. ** Argument pExpr is an (?, ?...) IN(...) expression. This 

  99804. ** function allocates and returns a nul-terminated string containing 

  99805. ** the affinities to be used for each column of the comparison.

  99806. **

  99807. ** It is the responsibility of the caller to ensure that the returned

  99808. ** string is eventually freed using sqlite3DbFree().

  99809. */

  99810. static char *exprINAffinity(Parse *pParse, Expr *pExpr){

  99811.   Expr *pLeft = pExpr->pLeft;

  99812.   int nVal = sqlite3ExprVectorSize(pLeft);

  99813.   Select *pSelect = (pExpr->flags & EP_xIsSelect) ? pExpr->x.pSelect : 0;

  99814.   char *zRet;

  99815. 

  99816.   assert( pExpr->op==TK_IN );

  99817.   zRet = sqlite3DbMallocRaw(pParse->db, nVal+1);

  99818.   if( zRet ){

  99819.     int i;

  99820.     for(i=0; i<nVal; i++){

  99821.       Expr *pA = sqlite3VectorFieldSubexpr(pLeft, i);

  99822.       char a = sqlite3ExprAffinity(pA);

  99823.       if( pSelect ){

  99824.         zRet[i] = sqlite3CompareAffinity(pSelect->pEList->a[i].pExpr, a);

  99825.       }else{

  99826.         zRet[i] = a;

  99827.       }

  99828.     }

  99829.     zRet[nVal] = '\0';

  99830.   }

  99831.   return zRet;

  99832. }

  99833. #endif

  99834. 

  99835. #ifndef SQLITE_OMIT_SUBQUERY

  99836. /*

  99837. ** Load the Parse object passed as the first argument with an error 

  99838. ** message of the form:

  99839. **

  99840. **   "sub-select returns N columns - expected M"

  99841. */   

  99842. SQLITE_PRIVATE void sqlite3SubselectError(Parse *pParse, int nActual, int nExpect){

  99843.   const char *zFmt = "sub-select returns %d columns - expected %d";

  99844.   sqlite3ErrorMsg(pParse, zFmt, nActual, nExpect);

  99845. }

  99846. #endif

  99847. 

  99848. /*

  99849. ** Expression pExpr is a vector that has been used in a context where

  99850. ** it is not permitted. If pExpr is a sub-select vector, this routine 

  99851. ** loads the Parse object with a message of the form:

  99852. **

  99853. **   "sub-select returns N columns - expected 1"

  99854. **

  99855. ** Or, if it is a regular scalar vector:

  99856. **

  99857. **   "row value misused"

  99858. */   

  99859. SQLITE_PRIVATE void sqlite3VectorErrorMsg(Parse *pParse, Expr *pExpr){

  99860. #ifndef SQLITE_OMIT_SUBQUERY

  99861.   if( pExpr->flags & EP_xIsSelect ){

  99862.     sqlite3SubselectError(pParse, pExpr->x.pSelect->pEList->nExpr, 1);

  99863.   }else

  99864. #endif

  99865.   {

  99866.     sqlite3ErrorMsg(pParse, "row value misused");

  99867.   }

  99868. }

  99869. 

  99870. #ifndef SQLITE_OMIT_SUBQUERY

  99871. /*

  99872. ** Generate code that will construct an ephemeral table containing all terms

  99873. ** in the RHS of an IN operator.  The IN operator can be in either of two

  99874. ** forms:

  99875. **

  99876. **     x IN (4,5,11)              -- IN operator with list on right-hand side

  99877. **     x IN (SELECT a FROM b)     -- IN operator with subquery on the right

  99878. **

  99879. ** The pExpr parameter is the IN operator.  The cursor number for the

  99880. ** constructed ephermeral table is returned.  The first time the ephemeral

  99881. ** table is computed, the cursor number is also stored in pExpr->iTable,

  99882. ** however the cursor number returned might not be the same, as it might

  99883. ** have been duplicated using OP_OpenDup.

  99884. **

  99885. ** If the LHS expression ("x" in the examples) is a column value, or

  99886. ** the SELECT statement returns a column value, then the affinity of that

  99887. ** column is used to build the index keys. If both 'x' and the

  99888. ** SELECT... statement are columns, then numeric affinity is used

  99889. ** if either column has NUMERIC or INTEGER affinity. If neither

  99890. ** 'x' nor the SELECT... statement are columns, then numeric affinity

  99891. ** is used.

  99892. */

  99893. SQLITE_PRIVATE void sqlite3CodeRhsOfIN(

  99894.   Parse *pParse,          /* Parsing context */

  99895.   Expr *pExpr,            /* The IN operator */

  99896.   int iTab                /* Use this cursor number */

  99897. ){

  99898.   int addrOnce = 0;           /* Address of the OP_Once instruction at top */

  99899.   int addr;                   /* Address of OP_OpenEphemeral instruction */

  99900.   Expr *pLeft;                /* the LHS of the IN operator */

  99901.   KeyInfo *pKeyInfo = 0;      /* Key information */

  99902.   int nVal;                   /* Size of vector pLeft */

  99903.   Vdbe *v;                    /* The prepared statement under construction */

  99904. 

  99905.   v = pParse->pVdbe;

  99906.   assert( v!=0 );

  99907. 

  99908.   /* The evaluation of the IN must be repeated every time it

  99909.   ** is encountered if any of the following is true:

  99910.   **

  99911.   **    *  The right-hand side is a correlated subquery

  99912.   **    *  The right-hand side is an expression list containing variables

  99913.   **    *  We are inside a trigger

  99914.   **

  99915.   ** If all of the above are false, then we can compute the RHS just once

  99916.   ** and reuse it many names.

  99917.   */

  99918.   if( !ExprHasProperty(pExpr, EP_VarSelect) && pParse->iSelfTab==0 ){

  99919.     /* Reuse of the RHS is allowed */

  99920.     /* If this routine has already been coded, but the previous code

  99921.     ** might not have been invoked yet, so invoke it now as a subroutine. 

  99922.     */

  99923.     if( ExprHasProperty(pExpr, EP_Subrtn) ){

  99924.       addrOnce = sqlite3VdbeAddOp0(v, OP_Once); VdbeCoverage(v);

  99925.       if( ExprHasProperty(pExpr, EP_xIsSelect) ){

  99926.         ExplainQueryPlan((pParse, 0, "REUSE LIST SUBQUERY %d",

  99927.               pExpr->x.pSelect->selId));

  99928.       }

  99929.       sqlite3VdbeAddOp2(v, OP_Gosub, pExpr->y.sub.regReturn,

  99930.                         pExpr->y.sub.iAddr);

  99931.       sqlite3VdbeAddOp2(v, OP_OpenDup, iTab, pExpr->iTable);

  99932.       sqlite3VdbeJumpHere(v, addrOnce);

  99933.       return;

  99934.     }

  99935. 

  99936.     /* Begin coding the subroutine */

  99937.     ExprSetProperty(pExpr, EP_Subrtn);

  99938.     pExpr->y.sub.regReturn = ++pParse->nMem;

  99939.     pExpr->y.sub.iAddr =

  99940.       sqlite3VdbeAddOp2(v, OP_Integer, 0, pExpr->y.sub.regReturn) + 1;

  99941.     VdbeComment((v, "return address"));

  99942. 

  99943.     addrOnce = sqlite3VdbeAddOp0(v, OP_Once); VdbeCoverage(v);

  99944.   }

  99945. 

  99946.   /* Check to see if this is a vector IN operator */

  99947.   pLeft = pExpr->pLeft;

  99948.   nVal = sqlite3ExprVectorSize(pLeft);

  99949. 

  99950.   /* Construct the ephemeral table that will contain the content of

  99951.   ** RHS of the IN operator.

  99952.   */

  99953.   pExpr->iTable = iTab;

  99954.   addr = sqlite3VdbeAddOp2(v, OP_OpenEphemeral, pExpr->iTable, nVal);

  99955. #ifdef SQLITE_ENABLE_EXPLAIN_COMMENTS

  99956.   if( ExprHasProperty(pExpr, EP_xIsSelect) ){

  99957.     VdbeComment((v, "Result of SELECT %u", pExpr->x.pSelect->selId));

  99958.   }else{

  99959.     VdbeComment((v, "RHS of IN operator"));

  99960.   }

  99961. #endif

  99962.   pKeyInfo = sqlite3KeyInfoAlloc(pParse->db, nVal, 1);

  99963. 

  99964.   if( ExprHasProperty(pExpr, EP_xIsSelect) ){

  99965.     /* Case 1:     expr IN (SELECT ...)

  99966.     **

  99967.     ** Generate code to write the results of the select into the temporary

  99968.     ** table allocated and opened above.

  99969.     */

  99970.     Select *pSelect = pExpr->x.pSelect;

  99971.     ExprList *pEList = pSelect->pEList;

  99972. 

  99973.     ExplainQueryPlan((pParse, 1, "%sLIST SUBQUERY %d",

  99974.         addrOnce?"":"CORRELATED ", pSelect->selId

  99975.     ));

  99976.     /* If the LHS and RHS of the IN operator do not match, that

  99977.     ** error will have been caught long before we reach this point. */

  99978.     if( ALWAYS(pEList->nExpr==nVal) ){

  99979.       SelectDest dest;

  99980.       int i;

  99981.       sqlite3SelectDestInit(&dest, SRT_Set, iTab);

  99982.       dest.zAffSdst = exprINAffinity(pParse, pExpr);

  99983.       pSelect->iLimit = 0;

  99984.       testcase( pSelect->selFlags & SF_Distinct );

  99985.       testcase( pKeyInfo==0 ); /* Caused by OOM in sqlite3KeyInfoAlloc() */

  99986.       if( sqlite3Select(pParse, pSelect, &dest) ){

  99987.         sqlite3DbFree(pParse->db, dest.zAffSdst);

  99988.         sqlite3KeyInfoUnref(pKeyInfo);

  99989.         return;

  99990.       }

  99991.       sqlite3DbFree(pParse->db, dest.zAffSdst);

  99992.       assert( pKeyInfo!=0 ); /* OOM will cause exit after sqlite3Select() */

  99993.       assert( pEList!=0 );

  99994.       assert( pEList->nExpr>0 );

  99995.       assert( sqlite3KeyInfoIsWriteable(pKeyInfo) );

  99996.       for(i=0; i<nVal; i++){

  99997.         Expr *p = sqlite3VectorFieldSubexpr(pLeft, i);

  99998.         pKeyInfo->aColl[i] = sqlite3BinaryCompareCollSeq(

  99999.             pParse, p, pEList->a[i].pExpr

  100000.         );

  100001.       }

  100002.     }

  100003.   }else if( ALWAYS(pExpr->x.pList!=0) ){

  100004.     /* Case 2:     expr IN (exprlist)

  100005.     **

  100006.     ** For each expression, build an index key from the evaluation and

  100007.     ** store it in the temporary table. If <expr> is a column, then use

  100008.     ** that columns affinity when building index keys. If <expr> is not

  100009.     ** a column, use numeric affinity.

  100010.     */

  100011.     char affinity;            /* Affinity of the LHS of the IN */

  100012.     int i;

  100013.     ExprList *pList = pExpr->x.pList;

  100014.     struct ExprList_item *pItem;

  100015.     int r1, r2, r3;

  100016.     affinity = sqlite3ExprAffinity(pLeft);

  100017.     if( !affinity ){

  100018.       affinity = SQLITE_AFF_BLOB;

  100019.     }

  100020.     if( pKeyInfo ){

  100021.       assert( sqlite3KeyInfoIsWriteable(pKeyInfo) );

  100022.       pKeyInfo->aColl[0] = sqlite3ExprCollSeq(pParse, pExpr->pLeft);

  100023.     }

  100024. 

  100025.     /* Loop through each expression in <exprlist>. */

  100026.     r1 = sqlite3GetTempReg(pParse);

  100027.     r2 = sqlite3GetTempReg(pParse);

  100028.     for(i=pList->nExpr, pItem=pList->a; i>0; i--, pItem++){

  100029.       Expr *pE2 = pItem->pExpr;

  100030. 

  100031.       /* If the expression is not constant then we will need to

  100032.       ** disable the test that was generated above that makes sure

  100033.       ** this code only executes once.  Because for a non-constant

  100034.       ** expression we need to rerun this code each time.

  100035.       */

  100036.       if( addrOnce && !sqlite3ExprIsConstant(pE2) ){

  100037.         sqlite3VdbeChangeToNoop(v, addrOnce);

  100038.         ExprClearProperty(pExpr, EP_Subrtn);

  100039.         addrOnce = 0;

  100040.       }

  100041. 

  100042.       /* Evaluate the expression and insert it into the temp table */

  100043.       r3 = sqlite3ExprCodeTarget(pParse, pE2, r1);

  100044.       sqlite3VdbeAddOp4(v, OP_MakeRecord, r3, 1, r2, &affinity, 1);

  100045.       sqlite3VdbeAddOp4Int(v, OP_IdxInsert, iTab, r2, r3, 1);

  100046.     }

  100047.     sqlite3ReleaseTempReg(pParse, r1);

  100048.     sqlite3ReleaseTempReg(pParse, r2);

  100049.   }

  100050.   if( pKeyInfo ){

  100051.     sqlite3VdbeChangeP4(v, addr, (void *)pKeyInfo, P4_KEYINFO);

  100052.   }

  100053.   if( addrOnce ){

  100054.     sqlite3VdbeJumpHere(v, addrOnce);

  100055.     /* Subroutine return */

  100056.     sqlite3VdbeAddOp1(v, OP_Return, pExpr->y.sub.regReturn);

  100057.     sqlite3VdbeChangeP1(v, pExpr->y.sub.iAddr-1, sqlite3VdbeCurrentAddr(v)-1);

  100058.   }

  100059. }

  100060. #endif /* SQLITE_OMIT_SUBQUERY */

  100061. 

  100062. /*

  100063. ** Generate code for scalar subqueries used as a subquery expression

  100064. ** or EXISTS operator:

  100065. **

  100066. **     (SELECT a FROM b)          -- subquery

  100067. **     EXISTS (SELECT a FROM b)   -- EXISTS subquery

  100068. **

  100069. ** The pExpr parameter is the SELECT or EXISTS operator to be coded.

  100070. **

  100071. ** The register that holds the result.  For a multi-column SELECT, 

  100072. ** the result is stored in a contiguous array of registers and the

  100073. ** return value is the register of the left-most result column.

  100074. ** Return 0 if an error occurs.

  100075. */

  100076. #ifndef SQLITE_OMIT_SUBQUERY

  100077. SQLITE_PRIVATE int sqlite3CodeSubselect(Parse *pParse, Expr *pExpr){

  100078.   int addrOnce = 0;           /* Address of OP_Once at top of subroutine */

  100079.   int rReg = 0;               /* Register storing resulting */

  100080.   Select *pSel;               /* SELECT statement to encode */

  100081.   SelectDest dest;            /* How to deal with SELECT result */

  100082.   int nReg;                   /* Registers to allocate */

  100083.   Expr *pLimit;               /* New limit expression */

  100084. 

  100085.   Vdbe *v = pParse->pVdbe;

  100086.   assert( v!=0 );

  100087.   testcase( pExpr->op==TK_EXISTS );

  100088.   testcase( pExpr->op==TK_SELECT );

  100089.   assert( pExpr->op==TK_EXISTS || pExpr->op==TK_SELECT );

  100090.   assert( ExprHasProperty(pExpr, EP_xIsSelect) );

  100091.   pSel = pExpr->x.pSelect;

  100092. 

  100093.   /* The evaluation of the EXISTS/SELECT must be repeated every time it

  100094.   ** is encountered if any of the following is true:

  100095.   **

  100096.   **    *  The right-hand side is a correlated subquery

  100097.   **    *  The right-hand side is an expression list containing variables

  100098.   **    *  We are inside a trigger

  100099.   **

  100100.   ** If all of the above are false, then we can run this code just once

  100101.   ** save the results, and reuse the same result on subsequent invocations.

  100102.   */

  100103.   if( !ExprHasProperty(pExpr, EP_VarSelect) ){

  100104.     /* If this routine has already been coded, then invoke it as a

  100105.     ** subroutine. */

  100106.     if( ExprHasProperty(pExpr, EP_Subrtn) ){

  100107.       ExplainQueryPlan((pParse, 0, "REUSE SUBQUERY %d", pSel->selId));

  100108.       sqlite3VdbeAddOp2(v, OP_Gosub, pExpr->y.sub.regReturn,

  100109.                         pExpr->y.sub.iAddr);

  100110.       return pExpr->iTable;

  100111.     }

  100112. 

  100113.     /* Begin coding the subroutine */

  100114.     ExprSetProperty(pExpr, EP_Subrtn);

  100115.     pExpr->y.sub.regReturn = ++pParse->nMem;

  100116.     pExpr->y.sub.iAddr =

  100117.       sqlite3VdbeAddOp2(v, OP_Integer, 0, pExpr->y.sub.regReturn) + 1;

  100118.     VdbeComment((v, "return address"));

  100119. 

  100120.     addrOnce = sqlite3VdbeAddOp0(v, OP_Once); VdbeCoverage(v);

  100121.   }

  100122.   

  100123.   /* For a SELECT, generate code to put the values for all columns of

  100124.   ** the first row into an array of registers and return the index of

  100125.   ** the first register.

  100126.   **

  100127.   ** If this is an EXISTS, write an integer 0 (not exists) or 1 (exists)

  100128.   ** into a register and return that register number.

  100129.   **

  100130.   ** In both cases, the query is augmented with "LIMIT 1".  Any 

  100131.   ** preexisting limit is discarded in place of the new LIMIT 1.

  100132.   */

  100133.   ExplainQueryPlan((pParse, 1, "%sSCALAR SUBQUERY %d",

  100134.         addrOnce?"":"CORRELATED ", pSel->selId));

  100135.   nReg = pExpr->op==TK_SELECT ? pSel->pEList->nExpr : 1;

  100136.   sqlite3SelectDestInit(&dest, 0, pParse->nMem+1);

  100137.   pParse->nMem += nReg;

  100138.   if( pExpr->op==TK_SELECT ){

  100139.     dest.eDest = SRT_Mem;

  100140.     dest.iSdst = dest.iSDParm;

  100141.     dest.nSdst = nReg;

  100142.     sqlite3VdbeAddOp3(v, OP_Null, 0, dest.iSDParm, dest.iSDParm+nReg-1);

  100143.     VdbeComment((v, "Init subquery result"));

  100144.   }else{

  100145.     dest.eDest = SRT_Exists;

  100146.     sqlite3VdbeAddOp2(v, OP_Integer, 0, dest.iSDParm);

  100147.     VdbeComment((v, "Init EXISTS result"));

  100148.   }

  100149.   pLimit = sqlite3ExprAlloc(pParse->db, TK_INTEGER,&sqlite3IntTokens[1], 0);

  100150.   if( pSel->pLimit ){

  100151.     sqlite3ExprDelete(pParse->db, pSel->pLimit->pLeft);

  100152.     pSel->pLimit->pLeft = pLimit;

  100153.   }else{

  100154.     pSel->pLimit = sqlite3PExpr(pParse, TK_LIMIT, pLimit, 0);

  100155.   }

  100156.   pSel->iLimit = 0;

  100157.   if( sqlite3Select(pParse, pSel, &dest) ){

  100158.     return 0;

  100159.   }

  100160.   pExpr->iTable = rReg = dest.iSDParm;

  100161.   ExprSetVVAProperty(pExpr, EP_NoReduce);

  100162.   if( addrOnce ){

  100163.     sqlite3VdbeJumpHere(v, addrOnce);

  100164. 

  100165.     /* Subroutine return */

  100166.     sqlite3VdbeAddOp1(v, OP_Return, pExpr->y.sub.regReturn);

  100167.     sqlite3VdbeChangeP1(v, pExpr->y.sub.iAddr-1, sqlite3VdbeCurrentAddr(v)-1);

  100168.   }

  100169. 

  100170.   return rReg;

  100171. }

  100172. #endif /* SQLITE_OMIT_SUBQUERY */

  100173. 

  100174. #ifndef SQLITE_OMIT_SUBQUERY

  100175. /*

  100176. ** Expr pIn is an IN(...) expression. This function checks that the 

  100177. ** sub-select on the RHS of the IN() operator has the same number of 

  100178. ** columns as the vector on the LHS. Or, if the RHS of the IN() is not 

  100179. ** a sub-query, that the LHS is a vector of size 1.

  100180. */

  100181. SQLITE_PRIVATE int sqlite3ExprCheckIN(Parse *pParse, Expr *pIn){

  100182.   int nVector = sqlite3ExprVectorSize(pIn->pLeft);

  100183.   if( (pIn->flags & EP_xIsSelect) ){

  100184.     if( nVector!=pIn->x.pSelect->pEList->nExpr ){

  100185.       sqlite3SubselectError(pParse, pIn->x.pSelect->pEList->nExpr, nVector);

  100186.       return 1;

  100187.     }

  100188.   }else if( nVector!=1 ){

  100189.     sqlite3VectorErrorMsg(pParse, pIn->pLeft);

  100190.     return 1;

  100191.   }

  100192.   return 0;

  100193. }

  100194. #endif

  100195. 

  100196. #ifndef SQLITE_OMIT_SUBQUERY

  100197. /*

  100198. ** Generate code for an IN expression.

  100199. **

  100200. **      x IN (SELECT ...)

  100201. **      x IN (value, value, ...)

  100202. **

  100203. ** The left-hand side (LHS) is a scalar or vector expression.  The 

  100204. ** right-hand side (RHS) is an array of zero or more scalar values, or a

  100205. ** subquery.  If the RHS is a subquery, the number of result columns must

  100206. ** match the number of columns in the vector on the LHS.  If the RHS is

  100207. ** a list of values, the LHS must be a scalar. 

  100208. **

  100209. ** The IN operator is true if the LHS value is contained within the RHS.

  100210. ** The result is false if the LHS is definitely not in the RHS.  The 

  100211. ** result is NULL if the presence of the LHS in the RHS cannot be 

  100212. ** determined due to NULLs.

  100213. **

  100214. ** This routine generates code that jumps to destIfFalse if the LHS is not 

  100215. ** contained within the RHS.  If due to NULLs we cannot determine if the LHS

  100216. ** is contained in the RHS then jump to destIfNull.  If the LHS is contained

  100217. ** within the RHS then fall through.

  100218. **

  100219. ** See the separate in-operator.md documentation file in the canonical

  100220. ** SQLite source tree for additional information.

  100221. */

  100222. static void sqlite3ExprCodeIN(

  100223.   Parse *pParse,        /* Parsing and code generating context */

  100224.   Expr *pExpr,          /* The IN expression */

  100225.   int destIfFalse,      /* Jump here if LHS is not contained in the RHS */

  100226.   int destIfNull        /* Jump here if the results are unknown due to NULLs */

  100227. ){

  100228.   int rRhsHasNull = 0;  /* Register that is true if RHS contains NULL values */

  100229.   int eType;            /* Type of the RHS */

  100230.   int rLhs;             /* Register(s) holding the LHS values */

  100231.   int rLhsOrig;         /* LHS values prior to reordering by aiMap[] */

  100232.   Vdbe *v;              /* Statement under construction */

  100233.   int *aiMap = 0;       /* Map from vector field to index column */

  100234.   char *zAff = 0;       /* Affinity string for comparisons */

  100235.   int nVector;          /* Size of vectors for this IN operator */

  100236.   int iDummy;           /* Dummy parameter to exprCodeVector() */

  100237.   Expr *pLeft;          /* The LHS of the IN operator */

  100238.   int i;                /* loop counter */

  100239.   int destStep2;        /* Where to jump when NULLs seen in step 2 */

  100240.   int destStep6 = 0;    /* Start of code for Step 6 */

  100241.   int addrTruthOp;      /* Address of opcode that determines the IN is true */

  100242.   int destNotNull;      /* Jump here if a comparison is not true in step 6 */

  100243.   int addrTop;          /* Top of the step-6 loop */ 

  100244.   int iTab = 0;         /* Index to use */

  100245. 

  100246.   pLeft = pExpr->pLeft;

  100247.   if( sqlite3ExprCheckIN(pParse, pExpr) ) return;

  100248.   zAff = exprINAffinity(pParse, pExpr);

  100249.   nVector = sqlite3ExprVectorSize(pExpr->pLeft);

  100250.   aiMap = (int*)sqlite3DbMallocZero(

  100251.       pParse->db, nVector*(sizeof(int) + sizeof(char)) + 1

  100252.   );

  100253.   if( pParse->db->mallocFailed ) goto sqlite3ExprCodeIN_oom_error;

  100254. 

  100255.   /* Attempt to compute the RHS. After this step, if anything other than

  100256.   ** IN_INDEX_NOOP is returned, the table opened with cursor iTab

  100257.   ** contains the values that make up the RHS. If IN_INDEX_NOOP is returned,

  100258.   ** the RHS has not yet been coded.  */

  100259.   v = pParse->pVdbe;

  100260.   assert( v!=0 );       /* OOM detected prior to this routine */

  100261.   VdbeNoopComment((v, "begin IN expr"));

  100262.   eType = sqlite3FindInIndex(pParse, pExpr,

  100263.                              IN_INDEX_MEMBERSHIP | IN_INDEX_NOOP_OK,

  100264.                              destIfFalse==destIfNull ? 0 : &rRhsHasNull,

  100265.                              aiMap, &iTab);

  100266. 

  100267.   assert( pParse->nErr || nVector==1 || eType==IN_INDEX_EPH

  100268.        || eType==IN_INDEX_INDEX_ASC || eType==IN_INDEX_INDEX_DESC 

  100269.   );

  100270. #ifdef SQLITE_DEBUG

  100271.   /* Confirm that aiMap[] contains nVector integer values between 0 and

  100272.   ** nVector-1. */

  100273.   for(i=0; i<nVector; i++){

  100274.     int j, cnt;

  100275.     for(cnt=j=0; j<nVector; j++) if( aiMap[j]==i ) cnt++;

  100276.     assert( cnt==1 );

  100277.   }

  100278. #endif

  100279. 

  100280.   /* Code the LHS, the <expr> from "<expr> IN (...)". If the LHS is a 

  100281.   ** vector, then it is stored in an array of nVector registers starting 

  100282.   ** at r1.

  100283.   **

  100284.   ** sqlite3FindInIndex() might have reordered the fields of the LHS vector

  100285.   ** so that the fields are in the same order as an existing index.   The

  100286.   ** aiMap[] array contains a mapping from the original LHS field order to

  100287.   ** the field order that matches the RHS index.

  100288.   */

  100289.   rLhsOrig = exprCodeVector(pParse, pLeft, &iDummy);

  100290.   for(i=0; i<nVector && aiMap[i]==i; i++){} /* Are LHS fields reordered? */

  100291.   if( i==nVector ){

  100292.     /* LHS fields are not reordered */

  100293.     rLhs = rLhsOrig;

  100294.   }else{

  100295.     /* Need to reorder the LHS fields according to aiMap */

  100296.     rLhs = sqlite3GetTempRange(pParse, nVector);

  100297.     for(i=0; i<nVector; i++){

  100298.       sqlite3VdbeAddOp3(v, OP_Copy, rLhsOrig+i, rLhs+aiMap[i], 0);

  100299.     }

  100300.   }

  100301. 

  100302.   /* If sqlite3FindInIndex() did not find or create an index that is

  100303.   ** suitable for evaluating the IN operator, then evaluate using a

  100304.   ** sequence of comparisons.

  100305.   **

  100306.   ** This is step (1) in the in-operator.md optimized algorithm.

  100307.   */

  100308.   if( eType==IN_INDEX_NOOP ){

  100309.     ExprList *pList = pExpr->x.pList;

  100310.     CollSeq *pColl = sqlite3ExprCollSeq(pParse, pExpr->pLeft);

  100311.     int labelOk = sqlite3VdbeMakeLabel(pParse);

  100312.     int r2, regToFree;

  100313.     int regCkNull = 0;

  100314.     int ii;

  100315.     assert( !ExprHasProperty(pExpr, EP_xIsSelect) );

  100316.     if( destIfNull!=destIfFalse ){

  100317.       regCkNull = sqlite3GetTempReg(pParse);

  100318.       sqlite3VdbeAddOp3(v, OP_BitAnd, rLhs, rLhs, regCkNull);

  100319.     }

  100320.     for(ii=0; ii<pList->nExpr; ii++){

  100321.       r2 = sqlite3ExprCodeTemp(pParse, pList->a[ii].pExpr, &regToFree);

  100322.       if( regCkNull && sqlite3ExprCanBeNull(pList->a[ii].pExpr) ){

  100323.         sqlite3VdbeAddOp3(v, OP_BitAnd, regCkNull, r2, regCkNull);

  100324.       }

  100325.       if( ii<pList->nExpr-1 || destIfNull!=destIfFalse ){

  100326.         sqlite3VdbeAddOp4(v, OP_Eq, rLhs, labelOk, r2,

  100327.                           (void*)pColl, P4_COLLSEQ);

  100328.         VdbeCoverageIf(v, ii<pList->nExpr-1);

  100329.         VdbeCoverageIf(v, ii==pList->nExpr-1);

  100330.         sqlite3VdbeChangeP5(v, zAff[0]);

  100331.       }else{

  100332.         assert( destIfNull==destIfFalse );

  100333.         sqlite3VdbeAddOp4(v, OP_Ne, rLhs, destIfFalse, r2,

  100334.                           (void*)pColl, P4_COLLSEQ); VdbeCoverage(v);

  100335.         sqlite3VdbeChangeP5(v, zAff[0] | SQLITE_JUMPIFNULL);

  100336.       }

  100337.       sqlite3ReleaseTempReg(pParse, regToFree);

  100338.     }

  100339.     if( regCkNull ){

  100340.       sqlite3VdbeAddOp2(v, OP_IsNull, regCkNull, destIfNull); VdbeCoverage(v);

  100341.       sqlite3VdbeGoto(v, destIfFalse);

  100342.     }

  100343.     sqlite3VdbeResolveLabel(v, labelOk);

  100344.     sqlite3ReleaseTempReg(pParse, regCkNull);

  100345.     goto sqlite3ExprCodeIN_finished;

  100346.   }

  100347. 

  100348.   /* Step 2: Check to see if the LHS contains any NULL columns.  If the

  100349.   ** LHS does contain NULLs then the result must be either FALSE or NULL.

  100350.   ** We will then skip the binary search of the RHS.

  100351.   */

  100352.   if( destIfNull==destIfFalse ){

  100353.     destStep2 = destIfFalse;

  100354.   }else{

  100355.     destStep2 = destStep6 = sqlite3VdbeMakeLabel(pParse);

  100356.   }

  100357.   for(i=0; i<nVector; i++){

  100358.     Expr *p = sqlite3VectorFieldSubexpr(pExpr->pLeft, i);

  100359.     if( sqlite3ExprCanBeNull(p) ){

  100360.       sqlite3VdbeAddOp2(v, OP_IsNull, rLhs+i, destStep2);

  100361.       VdbeCoverage(v);

  100362.     }

  100363.   }

  100364. 

  100365.   /* Step 3.  The LHS is now known to be non-NULL.  Do the binary search

  100366.   ** of the RHS using the LHS as a probe.  If found, the result is

  100367.   ** true.

  100368.   */

  100369.   if( eType==IN_INDEX_ROWID ){

  100370.     /* In this case, the RHS is the ROWID of table b-tree and so we also

  100371.     ** know that the RHS is non-NULL.  Hence, we combine steps 3 and 4

  100372.     ** into a single opcode. */

  100373.     sqlite3VdbeAddOp3(v, OP_SeekRowid, iTab, destIfFalse, rLhs);

  100374.     VdbeCoverage(v);

  100375.     addrTruthOp = sqlite3VdbeAddOp0(v, OP_Goto);  /* Return True */

  100376.   }else{

  100377.     sqlite3VdbeAddOp4(v, OP_Affinity, rLhs, nVector, 0, zAff, nVector);

  100378.     if( destIfFalse==destIfNull ){

  100379.       /* Combine Step 3 and Step 5 into a single opcode */

  100380.       sqlite3VdbeAddOp4Int(v, OP_NotFound, iTab, destIfFalse,

  100381.                            rLhs, nVector); VdbeCoverage(v);

  100382.       goto sqlite3ExprCodeIN_finished;

  100383.     }

  100384.     /* Ordinary Step 3, for the case where FALSE and NULL are distinct */

  100385.     addrTruthOp = sqlite3VdbeAddOp4Int(v, OP_Found, iTab, 0,

  100386.                                       rLhs, nVector); VdbeCoverage(v);

  100387.   }

  100388. 

  100389.   /* Step 4.  If the RHS is known to be non-NULL and we did not find

  100390.   ** an match on the search above, then the result must be FALSE.

  100391.   */

  100392.   if( rRhsHasNull && nVector==1 ){

  100393.     sqlite3VdbeAddOp2(v, OP_NotNull, rRhsHasNull, destIfFalse);

  100394.     VdbeCoverage(v);

  100395.   }

  100396. 

  100397.   /* Step 5.  If we do not care about the difference between NULL and

  100398.   ** FALSE, then just return false. 

  100399.   */

  100400.   if( destIfFalse==destIfNull ) sqlite3VdbeGoto(v, destIfFalse);

  100401. 

  100402.   /* Step 6: Loop through rows of the RHS.  Compare each row to the LHS.

  100403.   ** If any comparison is NULL, then the result is NULL.  If all

  100404.   ** comparisons are FALSE then the final result is FALSE.

  100405.   **

  100406.   ** For a scalar LHS, it is sufficient to check just the first row

  100407.   ** of the RHS.

  100408.   */

  100409.   if( destStep6 ) sqlite3VdbeResolveLabel(v, destStep6);

  100410.   addrTop = sqlite3VdbeAddOp2(v, OP_Rewind, iTab, destIfFalse);

  100411.   VdbeCoverage(v);

  100412.   if( nVector>1 ){

  100413.     destNotNull = sqlite3VdbeMakeLabel(pParse);

  100414.   }else{

  100415.     /* For nVector==1, combine steps 6 and 7 by immediately returning

  100416.     ** FALSE if the first comparison is not NULL */

  100417.     destNotNull = destIfFalse;

  100418.   }

  100419.   for(i=0; i<nVector; i++){

  100420.     Expr *p;

  100421.     CollSeq *pColl;

  100422.     int r3 = sqlite3GetTempReg(pParse);

  100423.     p = sqlite3VectorFieldSubexpr(pLeft, i);

  100424.     pColl = sqlite3ExprCollSeq(pParse, p);

  100425.     sqlite3VdbeAddOp3(v, OP_Column, iTab, i, r3);

  100426.     sqlite3VdbeAddOp4(v, OP_Ne, rLhs+i, destNotNull, r3,

  100427.                       (void*)pColl, P4_COLLSEQ);

  100428.     VdbeCoverage(v);

  100429.     sqlite3ReleaseTempReg(pParse, r3);

  100430.   }

  100431.   sqlite3VdbeAddOp2(v, OP_Goto, 0, destIfNull);

  100432.   if( nVector>1 ){

  100433.     sqlite3VdbeResolveLabel(v, destNotNull);

  100434.     sqlite3VdbeAddOp2(v, OP_Next, iTab, addrTop+1);

  100435.     VdbeCoverage(v);

  100436. 

  100437.     /* Step 7:  If we reach this point, we know that the result must

  100438.     ** be false. */

  100439.     sqlite3VdbeAddOp2(v, OP_Goto, 0, destIfFalse);

  100440.   }

  100441. 

  100442.   /* Jumps here in order to return true. */

  100443.   sqlite3VdbeJumpHere(v, addrTruthOp);

  100444. 

  100445. sqlite3ExprCodeIN_finished:

  100446.   if( rLhs!=rLhsOrig ) sqlite3ReleaseTempReg(pParse, rLhs);

  100447.   VdbeComment((v, "end IN expr"));

  100448. sqlite3ExprCodeIN_oom_error:

  100449.   sqlite3DbFree(pParse->db, aiMap);

  100450.   sqlite3DbFree(pParse->db, zAff);

  100451. }

  100452. #endif /* SQLITE_OMIT_SUBQUERY */

  100453. 

  100454. #ifndef SQLITE_OMIT_FLOATING_POINT

  100455. /*

  100456. ** Generate an instruction that will put the floating point

  100457. ** value described by z[0..n-1] into register iMem.

  100458. **

  100459. ** The z[] string will probably not be zero-terminated.  But the 

  100460. ** z[n] character is guaranteed to be something that does not look

  100461. ** like the continuation of the number.

  100462. */

  100463. static void codeReal(Vdbe *v, const char *z, int negateFlag, int iMem){

  100464.   if( ALWAYS(z!=0) ){

  100465.     double value;

  100466.     sqlite3AtoF(z, &value, sqlite3Strlen30(z), SQLITE_UTF8);

  100467.     assert( !sqlite3IsNaN(value) ); /* The new AtoF never returns NaN */

  100468.     if( negateFlag ) value = -value;

  100469.     sqlite3VdbeAddOp4Dup8(v, OP_Real, 0, iMem, 0, (u8*)&value, P4_REAL);

  100470.   }

  100471. }

  100472. #endif

  100473. 

  100474. 

  100475. /*

  100476. ** Generate an instruction that will put the integer describe by

  100477. ** text z[0..n-1] into register iMem.

  100478. **

  100479. ** Expr.u.zToken is always UTF8 and zero-terminated.

  100480. */

  100481. static void codeInteger(Parse *pParse, Expr *pExpr, int negFlag, int iMem){

  100482.   Vdbe *v = pParse->pVdbe;

  100483.   if( pExpr->flags & EP_IntValue ){

  100484.     int i = pExpr->u.iValue;

  100485.     assert( i>=0 );

  100486.     if( negFlag ) i = -i;

  100487.     sqlite3VdbeAddOp2(v, OP_Integer, i, iMem);

  100488.   }else{

  100489.     int c;

  100490.     i64 value;

  100491.     const char *z = pExpr->u.zToken;

  100492.     assert( z!=0 );

  100493.     c = sqlite3DecOrHexToI64(z, &value);

  100494.     if( (c==3 && !negFlag) || (c==2) || (negFlag && value==SMALLEST_INT64)){

  100495. #ifdef SQLITE_OMIT_FLOATING_POINT

  100496.       sqlite3ErrorMsg(pParse, "oversized integer: %s%s", negFlag ? "-" : "", z);

  100497. #else

  100498. #ifndef SQLITE_OMIT_HEX_INTEGER

  100499.       if( sqlite3_strnicmp(z,"0x",2)==0 ){

  100500.         sqlite3ErrorMsg(pParse, "hex literal too big: %s%s", negFlag?"-":"",z);

  100501.       }else

  100502. #endif

  100503.       {

  100504.         codeReal(v, z, negFlag, iMem);

  100505.       }

  100506. #endif

  100507.     }else{

  100508.       if( negFlag ){ value = c==3 ? SMALLEST_INT64 : -value; }

  100509.       sqlite3VdbeAddOp4Dup8(v, OP_Int64, 0, iMem, 0, (u8*)&value, P4_INT64);

  100510.     }

  100511.   }

  100512. }

  100513. 

  100514. 

  100515. /* Generate code that will load into register regOut a value that is

  100516. ** appropriate for the iIdxCol-th column of index pIdx.

  100517. */

  100518. SQLITE_PRIVATE void sqlite3ExprCodeLoadIndexColumn(

  100519.   Parse *pParse,  /* The parsing context */

  100520.   Index *pIdx,    /* The index whose column is to be loaded */

  100521.   int iTabCur,    /* Cursor pointing to a table row */

  100522.   int iIdxCol,    /* The column of the index to be loaded */

  100523.   int regOut      /* Store the index column value in this register */

  100524. ){

  100525.   i16 iTabCol = pIdx->aiColumn[iIdxCol];

  100526.   if( iTabCol==XN_EXPR ){

  100527.     assert( pIdx->aColExpr );

  100528.     assert( pIdx->aColExpr->nExpr>iIdxCol );

  100529.     pParse->iSelfTab = iTabCur + 1;

  100530.     sqlite3ExprCodeCopy(pParse, pIdx->aColExpr->a[iIdxCol].pExpr, regOut);

  100531.     pParse->iSelfTab = 0;

  100532.   }else{

  100533.     sqlite3ExprCodeGetColumnOfTable(pParse->pVdbe, pIdx->pTable, iTabCur,

  100534.                                     iTabCol, regOut);

  100535.   }

  100536. }

  100537. 

  100538. /*

  100539. ** Generate code to extract the value of the iCol-th column of a table.

  100540. */

  100541. SQLITE_PRIVATE void sqlite3ExprCodeGetColumnOfTable(

  100542.   Vdbe *v,        /* The VDBE under construction */

  100543.   Table *pTab,    /* The table containing the value */

  100544.   int iTabCur,    /* The table cursor.  Or the PK cursor for WITHOUT ROWID */

  100545.   int iCol,       /* Index of the column to extract */

  100546.   int regOut      /* Extract the value into this register */

  100547. ){

  100548.   if( pTab==0 ){

  100549.     sqlite3VdbeAddOp3(v, OP_Column, iTabCur, iCol, regOut);

  100550.     return;

  100551.   }

  100552.   if( iCol<0 || iCol==pTab->iPKey ){

  100553.     sqlite3VdbeAddOp2(v, OP_Rowid, iTabCur, regOut);

  100554.   }else{

  100555.     int op = IsVirtual(pTab) ? OP_VColumn : OP_Column;

  100556.     int x = iCol;

  100557.     if( !HasRowid(pTab) && !IsVirtual(pTab) ){

  100558.       x = sqlite3ColumnOfIndex(sqlite3PrimaryKeyIndex(pTab), iCol);

  100559.     }

  100560.     sqlite3VdbeAddOp3(v, op, iTabCur, x, regOut);

  100561.   }

  100562.   if( iCol>=0 ){

  100563.     sqlite3ColumnDefault(v, pTab, iCol, regOut);

  100564.   }

  100565. }

  100566. 

  100567. /*

  100568. ** Generate code that will extract the iColumn-th column from

  100569. ** table pTab and store the column value in register iReg. 

  100570. **

  100571. ** There must be an open cursor to pTab in iTable when this routine

  100572. ** is called.  If iColumn<0 then code is generated that extracts the rowid.

  100573. */

  100574. SQLITE_PRIVATE int sqlite3ExprCodeGetColumn(

  100575.   Parse *pParse,   /* Parsing and code generating context */

  100576.   Table *pTab,     /* Description of the table we are reading from */

  100577.   int iColumn,     /* Index of the table column */

  100578.   int iTable,      /* The cursor pointing to the table */

  100579.   int iReg,        /* Store results here */

  100580.   u8 p5            /* P5 value for OP_Column + FLAGS */

  100581. ){

  100582.   Vdbe *v = pParse->pVdbe;

  100583.   assert( v!=0 );

  100584.   sqlite3ExprCodeGetColumnOfTable(v, pTab, iTable, iColumn, iReg);

  100585.   if( p5 ){

  100586.     sqlite3VdbeChangeP5(v, p5);

  100587.   }

  100588.   return iReg;

  100589. }

  100590. 

  100591. /*

  100592. ** Generate code to move content from registers iFrom...iFrom+nReg-1

  100593. ** over to iTo..iTo+nReg-1.

  100594. */

  100595. SQLITE_PRIVATE void sqlite3ExprCodeMove(Parse *pParse, int iFrom, int iTo, int nReg){

  100596.   assert( iFrom>=iTo+nReg || iFrom+nReg<=iTo );

  100597.   sqlite3VdbeAddOp3(pParse->pVdbe, OP_Move, iFrom, iTo, nReg);

  100598. }

  100599. 

  100600. /*

  100601. ** Convert a scalar expression node to a TK_REGISTER referencing

  100602. ** register iReg.  The caller must ensure that iReg already contains

  100603. ** the correct value for the expression.

  100604. */

  100605. static void exprToRegister(Expr *pExpr, int iReg){

  100606.   Expr *p = sqlite3ExprSkipCollate(pExpr);

  100607.   p->op2 = p->op;

  100608.   p->op = TK_REGISTER;

  100609.   p->iTable = iReg;

  100610.   ExprClearProperty(p, EP_Skip);

  100611. }

  100612. 

  100613. /*

  100614. ** Evaluate an expression (either a vector or a scalar expression) and store

  100615. ** the result in continguous temporary registers.  Return the index of

  100616. ** the first register used to store the result.

  100617. **

  100618. ** If the returned result register is a temporary scalar, then also write

  100619. ** that register number into *piFreeable.  If the returned result register

  100620. ** is not a temporary or if the expression is a vector set *piFreeable

  100621. ** to 0.

  100622. */

  100623. static int exprCodeVector(Parse *pParse, Expr *p, int *piFreeable){

  100624.   int iResult;

  100625.   int nResult = sqlite3ExprVectorSize(p);

  100626.   if( nResult==1 ){

  100627.     iResult = sqlite3ExprCodeTemp(pParse, p, piFreeable);

  100628.   }else{

  100629.     *piFreeable = 0;

  100630.     if( p->op==TK_SELECT ){

  100631. #if SQLITE_OMIT_SUBQUERY

  100632.       iResult = 0;

  100633. #else

  100634.       iResult = sqlite3CodeSubselect(pParse, p);

  100635. #endif

  100636.     }else{

  100637.       int i;

  100638.       iResult = pParse->nMem+1;

  100639.       pParse->nMem += nResult;

  100640.       for(i=0; i<nResult; i++){

  100641.         sqlite3ExprCodeFactorable(pParse, p->x.pList->a[i].pExpr, i+iResult);

  100642.       }

  100643.     }

  100644.   }

  100645.   return iResult;

  100646. }

  100647. 

  100648. 

  100649. /*

  100650. ** Generate code into the current Vdbe to evaluate the given

  100651. ** expression.  Attempt to store the results in register "target".

  100652. ** Return the register where results are stored.

  100653. **

  100654. ** With this routine, there is no guarantee that results will

  100655. ** be stored in target.  The result might be stored in some other

  100656. ** register if it is convenient to do so.  The calling function

  100657. ** must check the return code and move the results to the desired

  100658. ** register.

  100659. */

  100660. SQLITE_PRIVATE int sqlite3ExprCodeTarget(Parse *pParse, Expr *pExpr, int target){

  100661.   Vdbe *v = pParse->pVdbe;  /* The VM under construction */

  100662.   int op;                   /* The opcode being coded */

  100663.   int inReg = target;       /* Results stored in register inReg */

  100664.   int regFree1 = 0;         /* If non-zero free this temporary register */

  100665.   int regFree2 = 0;         /* If non-zero free this temporary register */

  100666.   int r1, r2;               /* Various register numbers */

  100667.   Expr tempX;               /* Temporary expression node */

  100668.   int p5 = 0;

  100669. 

  100670.   assert( target>0 && target<=pParse->nMem );

  100671.   if( v==0 ){

  100672.     assert( pParse->db->mallocFailed );

  100673.     return 0;

  100674.   }

  100675. 

  100676. expr_code_doover:

  100677.   if( pExpr==0 ){

  100678.     op = TK_NULL;

  100679.   }else{

  100680.     op = pExpr->op;

  100681.   }

  100682.   switch( op ){

  100683.     case TK_AGG_COLUMN: {

  100684.       AggInfo *pAggInfo = pExpr->pAggInfo;

  100685.       struct AggInfo_col *pCol = &pAggInfo->aCol[pExpr->iAgg];

  100686.       if( !pAggInfo->directMode ){

  100687.         assert( pCol->iMem>0 );

  100688.         return pCol->iMem;

  100689.       }else if( pAggInfo->useSortingIdx ){

  100690.         sqlite3VdbeAddOp3(v, OP_Column, pAggInfo->sortingIdxPTab,

  100691.                               pCol->iSorterColumn, target);

  100692.         return target;

  100693.       }

  100694.       /* Otherwise, fall thru into the TK_COLUMN case */

  100695.     }

  100696.     case TK_COLUMN: {

  100697.       int iTab = pExpr->iTable;

  100698.       if( ExprHasProperty(pExpr, EP_FixedCol) ){

  100699.         /* This COLUMN expression is really a constant due to WHERE clause

  100700.         ** constraints, and that constant is coded by the pExpr->pLeft

  100701.         ** expresssion.  However, make sure the constant has the correct

  100702.         ** datatype by applying the Affinity of the table column to the

  100703.         ** constant.

  100704.         */

  100705.         int iReg = sqlite3ExprCodeTarget(pParse, pExpr->pLeft,target);

  100706.         int aff = sqlite3TableColumnAffinity(pExpr->y.pTab, pExpr->iColumn);

  100707.         if( aff!=SQLITE_AFF_BLOB ){

  100708.           static const char zAff[] = "B\000C\000D\000E";

  100709.           assert( SQLITE_AFF_BLOB=='A' );

  100710.           assert( SQLITE_AFF_TEXT=='B' );

  100711.           if( iReg!=target ){

  100712.             sqlite3VdbeAddOp2(v, OP_SCopy, iReg, target);

  100713.             iReg = target;

  100714.           }

  100715.           sqlite3VdbeAddOp4(v, OP_Affinity, iReg, 1, 0,

  100716.                             &zAff[(aff-'B')*2], P4_STATIC);

  100717.         }

  100718.         return iReg;

  100719.       }

  100720.       if( iTab<0 ){

  100721.         if( pParse->iSelfTab<0 ){

  100722.           /* Generating CHECK constraints or inserting into partial index */

  100723.           return pExpr->iColumn - pParse->iSelfTab;

  100724.         }else{

  100725.           /* Coding an expression that is part of an index where column names

  100726.           ** in the index refer to the table to which the index belongs */

  100727.           iTab = pParse->iSelfTab - 1;

  100728.         }

  100729.       }

  100730.       return sqlite3ExprCodeGetColumn(pParse, pExpr->y.pTab,

  100731.                                pExpr->iColumn, iTab, target,

  100732.                                pExpr->op2);

  100733.     }

  100734.     case TK_INTEGER: {

  100735.       codeInteger(pParse, pExpr, 0, target);

  100736.       return target;

  100737.     }

  100738.     case TK_TRUEFALSE: {

  100739.       sqlite3VdbeAddOp2(v, OP_Integer, sqlite3ExprTruthValue(pExpr), target);

  100740.       return target;

  100741.     }

  100742. #ifndef SQLITE_OMIT_FLOATING_POINT

  100743.     case TK_FLOAT: {

  100744.       assert( !ExprHasProperty(pExpr, EP_IntValue) );

  100745.       codeReal(v, pExpr->u.zToken, 0, target);

  100746.       return target;

  100747.     }

  100748. #endif

  100749.     case TK_STRING: {

  100750.       assert( !ExprHasProperty(pExpr, EP_IntValue) );

  100751.       sqlite3VdbeLoadString(v, target, pExpr->u.zToken);

  100752.       return target;

  100753.     }

  100754.     case TK_NULL: {

  100755.       sqlite3VdbeAddOp2(v, OP_Null, 0, target);

  100756.       return target;

  100757.     }

  100758. #ifndef SQLITE_OMIT_BLOB_LITERAL

  100759.     case TK_BLOB: {

  100760.       int n;

  100761.       const char *z;

  100762.       char *zBlob;

  100763.       assert( !ExprHasProperty(pExpr, EP_IntValue) );

  100764.       assert( pExpr->u.zToken[0]=='x' || pExpr->u.zToken[0]=='X' );

  100765.       assert( pExpr->u.zToken[1]=='\'' );

  100766.       z = &pExpr->u.zToken[2];

  100767.       n = sqlite3Strlen30(z) - 1;

  100768.       assert( z[n]=='\'' );

  100769.       zBlob = sqlite3HexToBlob(sqlite3VdbeDb(v), z, n);

  100770.       sqlite3VdbeAddOp4(v, OP_Blob, n/2, target, 0, zBlob, P4_DYNAMIC);

  100771.       return target;

  100772.     }

  100773. #endif

  100774.     case TK_VARIABLE: {

  100775.       assert( !ExprHasProperty(pExpr, EP_IntValue) );

  100776.       assert( pExpr->u.zToken!=0 );

  100777.       assert( pExpr->u.zToken[0]!=0 );

  100778.       sqlite3VdbeAddOp2(v, OP_Variable, pExpr->iColumn, target);

  100779.       if( pExpr->u.zToken[1]!=0 ){

  100780.         const char *z = sqlite3VListNumToName(pParse->pVList, pExpr->iColumn);

  100781.         assert( pExpr->u.zToken[0]=='?' || strcmp(pExpr->u.zToken, z)==0 );

  100782.         pParse->pVList[0] = 0; /* Indicate VList may no longer be enlarged */

  100783.         sqlite3VdbeAppendP4(v, (char*)z, P4_STATIC);

  100784.       }

  100785.       return target;

  100786.     }

  100787.     case TK_REGISTER: {

  100788.       return pExpr->iTable;

  100789.     }

  100790. #ifndef SQLITE_OMIT_CAST

  100791.     case TK_CAST: {

  100792.       /* Expressions of the form:   CAST(pLeft AS token) */

  100793.       inReg = sqlite3ExprCodeTarget(pParse, pExpr->pLeft, target);

  100794.       if( inReg!=target ){

  100795.         sqlite3VdbeAddOp2(v, OP_SCopy, inReg, target);

  100796.         inReg = target;

  100797.       }

  100798.       sqlite3VdbeAddOp2(v, OP_Cast, target,

  100799.                         sqlite3AffinityType(pExpr->u.zToken, 0));

  100800.       return inReg;

  100801.     }

  100802. #endif /* SQLITE_OMIT_CAST */

  100803.     case TK_IS:

  100804.     case TK_ISNOT:

  100805.       op = (op==TK_IS) ? TK_EQ : TK_NE;

  100806.       p5 = SQLITE_NULLEQ;

  100807.       /* fall-through */

  100808.     case TK_LT:

  100809.     case TK_LE:

  100810.     case TK_GT:

  100811.     case TK_GE:

  100812.     case TK_NE:

  100813.     case TK_EQ: {

  100814.       Expr *pLeft = pExpr->pLeft;

  100815.       if( sqlite3ExprIsVector(pLeft) ){

  100816.         codeVectorCompare(pParse, pExpr, target, op, p5);

  100817.       }else{

  100818.         r1 = sqlite3ExprCodeTemp(pParse, pLeft, &regFree1);

  100819.         r2 = sqlite3ExprCodeTemp(pParse, pExpr->pRight, &regFree2);

  100820.         codeCompare(pParse, pLeft, pExpr->pRight, op,

  100821.             r1, r2, inReg, SQLITE_STOREP2 | p5);

  100822.         assert(TK_LT==OP_Lt); testcase(op==OP_Lt); VdbeCoverageIf(v,op==OP_Lt);

  100823.         assert(TK_LE==OP_Le); testcase(op==OP_Le); VdbeCoverageIf(v,op==OP_Le);

  100824.         assert(TK_GT==OP_Gt); testcase(op==OP_Gt); VdbeCoverageIf(v,op==OP_Gt);

  100825.         assert(TK_GE==OP_Ge); testcase(op==OP_Ge); VdbeCoverageIf(v,op==OP_Ge);

  100826.         assert(TK_EQ==OP_Eq); testcase(op==OP_Eq); VdbeCoverageIf(v,op==OP_Eq);

  100827.         assert(TK_NE==OP_Ne); testcase(op==OP_Ne); VdbeCoverageIf(v,op==OP_Ne);

  100828.         testcase( regFree1==0 );

  100829.         testcase( regFree2==0 );

  100830.       }

  100831.       break;

  100832.     }

  100833.     case TK_AND:

  100834.     case TK_OR:

  100835.     case TK_PLUS:

  100836.     case TK_STAR:

  100837.     case TK_MINUS:

  100838.     case TK_REM:

  100839.     case TK_BITAND:

  100840.     case TK_BITOR:

  100841.     case TK_SLASH:

  100842.     case TK_LSHIFT:

  100843.     case TK_RSHIFT: 

  100844.     case TK_CONCAT: {

  100845.       assert( TK_AND==OP_And );            testcase( op==TK_AND );

  100846.       assert( TK_OR==OP_Or );              testcase( op==TK_OR );

  100847.       assert( TK_PLUS==OP_Add );           testcase( op==TK_PLUS );

  100848.       assert( TK_MINUS==OP_Subtract );     testcase( op==TK_MINUS );

  100849.       assert( TK_REM==OP_Remainder );      testcase( op==TK_REM );

  100850.       assert( TK_BITAND==OP_BitAnd );      testcase( op==TK_BITAND );

  100851.       assert( TK_BITOR==OP_BitOr );        testcase( op==TK_BITOR );

  100852.       assert( TK_SLASH==OP_Divide );       testcase( op==TK_SLASH );

  100853.       assert( TK_LSHIFT==OP_ShiftLeft );   testcase( op==TK_LSHIFT );

  100854.       assert( TK_RSHIFT==OP_ShiftRight );  testcase( op==TK_RSHIFT );

  100855.       assert( TK_CONCAT==OP_Concat );      testcase( op==TK_CONCAT );

  100856.       r1 = sqlite3ExprCodeTemp(pParse, pExpr->pLeft, &regFree1);

  100857.       r2 = sqlite3ExprCodeTemp(pParse, pExpr->pRight, &regFree2);

  100858.       sqlite3VdbeAddOp3(v, op, r2, r1, target);

  100859.       testcase( regFree1==0 );

  100860.       testcase( regFree2==0 );

  100861.       break;

  100862.     }

  100863.     case TK_UMINUS: {

  100864.       Expr *pLeft = pExpr->pLeft;

  100865.       assert( pLeft );

  100866.       if( pLeft->op==TK_INTEGER ){

  100867.         codeInteger(pParse, pLeft, 1, target);

  100868.         return target;

  100869. #ifndef SQLITE_OMIT_FLOATING_POINT

  100870.       }else if( pLeft->op==TK_FLOAT ){

  100871.         assert( !ExprHasProperty(pExpr, EP_IntValue) );

  100872.         codeReal(v, pLeft->u.zToken, 1, target);

  100873.         return target;

  100874. #endif

  100875.       }else{

  100876.         tempX.op = TK_INTEGER;

  100877.         tempX.flags = EP_IntValue|EP_TokenOnly;

  100878.         tempX.u.iValue = 0;

  100879.         r1 = sqlite3ExprCodeTemp(pParse, &tempX, &regFree1);

  100880.         r2 = sqlite3ExprCodeTemp(pParse, pExpr->pLeft, &regFree2);

  100881.         sqlite3VdbeAddOp3(v, OP_Subtract, r2, r1, target);

  100882.         testcase( regFree2==0 );

  100883.       }

  100884.       break;

  100885.     }

  100886.     case TK_BITNOT:

  100887.     case TK_NOT: {

  100888.       assert( TK_BITNOT==OP_BitNot );   testcase( op==TK_BITNOT );

  100889.       assert( TK_NOT==OP_Not );         testcase( op==TK_NOT );

  100890.       r1 = sqlite3ExprCodeTemp(pParse, pExpr->pLeft, &regFree1);

  100891.       testcase( regFree1==0 );

  100892.       sqlite3VdbeAddOp2(v, op, r1, inReg);

  100893.       break;

  100894.     }

  100895.     case TK_TRUTH: {

  100896.       int isTrue;    /* IS TRUE or IS NOT TRUE */

  100897.       int bNormal;   /* IS TRUE or IS FALSE */

  100898.       r1 = sqlite3ExprCodeTemp(pParse, pExpr->pLeft, &regFree1);

  100899.       testcase( regFree1==0 );

  100900.       isTrue = sqlite3ExprTruthValue(pExpr->pRight);

  100901.       bNormal = pExpr->op2==TK_IS;

  100902.       testcase( isTrue && bNormal);

  100903.       testcase( !isTrue && bNormal);

  100904.       sqlite3VdbeAddOp4Int(v, OP_IsTrue, r1, inReg, !isTrue, isTrue ^ bNormal);

  100905.       break;

  100906.     }

  100907.     case TK_ISNULL:

  100908.     case TK_NOTNULL: {

  100909.       int addr;

  100910.       assert( TK_ISNULL==OP_IsNull );   testcase( op==TK_ISNULL );

  100911.       assert( TK_NOTNULL==OP_NotNull ); testcase( op==TK_NOTNULL );

  100912.       sqlite3VdbeAddOp2(v, OP_Integer, 1, target);

  100913.       r1 = sqlite3ExprCodeTemp(pParse, pExpr->pLeft, &regFree1);

  100914.       testcase( regFree1==0 );

  100915.       addr = sqlite3VdbeAddOp1(v, op, r1);

  100916.       VdbeCoverageIf(v, op==TK_ISNULL);

  100917.       VdbeCoverageIf(v, op==TK_NOTNULL);

  100918.       sqlite3VdbeAddOp2(v, OP_Integer, 0, target);

  100919.       sqlite3VdbeJumpHere(v, addr);

  100920.       break;

  100921.     }

  100922.     case TK_AGG_FUNCTION: {

  100923.       AggInfo *pInfo = pExpr->pAggInfo;

  100924.       if( pInfo==0 ){

  100925.         assert( !ExprHasProperty(pExpr, EP_IntValue) );

  100926.         sqlite3ErrorMsg(pParse, "misuse of aggregate: %s()", pExpr->u.zToken);

  100927.       }else{

  100928.         return pInfo->aFunc[pExpr->iAgg].iMem;

  100929.       }

  100930.       break;

  100931.     }

  100932.     case TK_FUNCTION: {

  100933.       ExprList *pFarg;       /* List of function arguments */

  100934.       int nFarg;             /* Number of function arguments */

  100935.       FuncDef *pDef;         /* The function definition object */

  100936.       const char *zId;       /* The function name */

  100937.       u32 constMask = 0;     /* Mask of function arguments that are constant */

  100938.       int i;                 /* Loop counter */

  100939.       sqlite3 *db = pParse->db;  /* The database connection */

  100940.       u8 enc = ENC(db);      /* The text encoding used by this database */

  100941.       CollSeq *pColl = 0;    /* A collating sequence */

  100942. 

  100943. #ifndef SQLITE_OMIT_WINDOWFUNC

  100944.       if( ExprHasProperty(pExpr, EP_WinFunc) ){

  100945.         return pExpr->y.pWin->regResult;

  100946.       }

  100947. #endif

  100948. 

  100949.       if( ConstFactorOk(pParse) && sqlite3ExprIsConstantNotJoin(pExpr) ){

  100950.         /* SQL functions can be expensive. So try to move constant functions

  100951.         ** out of the inner loop, even if that means an extra OP_Copy. */

  100952.         return sqlite3ExprCodeAtInit(pParse, pExpr, -1);

  100953.       }

  100954.       assert( !ExprHasProperty(pExpr, EP_xIsSelect) );

  100955.       if( ExprHasProperty(pExpr, EP_TokenOnly) ){

  100956.         pFarg = 0;

  100957.       }else{

  100958.         pFarg = pExpr->x.pList;

  100959.       }

  100960.       nFarg = pFarg ? pFarg->nExpr : 0;

  100961.       assert( !ExprHasProperty(pExpr, EP_IntValue) );

  100962.       zId = pExpr->u.zToken;

  100963.       pDef = sqlite3FindFunction(db, zId, nFarg, enc, 0);

  100964. #ifdef SQLITE_ENABLE_UNKNOWN_SQL_FUNCTION

  100965.       if( pDef==0 && pParse->explain ){

  100966.         pDef = sqlite3FindFunction(db, "unknown", nFarg, enc, 0);

  100967.       }

  100968. #endif

  100969.       if( pDef==0 || pDef->xFinalize!=0 ){

  100970.         sqlite3ErrorMsg(pParse, "unknown function: %s()", zId);

  100971.         break;

  100972.       }

  100973. 

  100974.       /* Attempt a direct implementation of the built-in COALESCE() and

  100975.       ** IFNULL() functions.  This avoids unnecessary evaluation of

  100976.       ** arguments past the first non-NULL argument.

  100977.       */

  100978.       if( pDef->funcFlags & SQLITE_FUNC_COALESCE ){

  100979.         int endCoalesce = sqlite3VdbeMakeLabel(pParse);

  100980.         assert( nFarg>=2 );

  100981.         sqlite3ExprCode(pParse, pFarg->a[0].pExpr, target);

  100982.         for(i=1; i<nFarg; i++){

  100983.           sqlite3VdbeAddOp2(v, OP_NotNull, target, endCoalesce);

  100984.           VdbeCoverage(v);

  100985.           sqlite3ExprCode(pParse, pFarg->a[i].pExpr, target);

  100986.         }

  100987.         sqlite3VdbeResolveLabel(v, endCoalesce);

  100988.         break;

  100989.       }

  100990. 

  100991.       /* The UNLIKELY() function is a no-op.  The result is the value

  100992.       ** of the first argument.

  100993.       */

  100994.       if( pDef->funcFlags & SQLITE_FUNC_UNLIKELY ){

  100995.         assert( nFarg>=1 );

  100996.         return sqlite3ExprCodeTarget(pParse, pFarg->a[0].pExpr, target);

  100997.       }

  100998. 

  100999. #ifdef SQLITE_DEBUG

  101000.       /* The AFFINITY() function evaluates to a string that describes

  101001.       ** the type affinity of the argument.  This is used for testing of

  101002.       ** the SQLite type logic.

  101003.       */

  101004.       if( pDef->funcFlags & SQLITE_FUNC_AFFINITY ){

  101005.         const char *azAff[] = { "blob", "text", "numeric", "integer", "real" };

  101006.         char aff;

  101007.         assert( nFarg==1 );

  101008.         aff = sqlite3ExprAffinity(pFarg->a[0].pExpr);

  101009.         sqlite3VdbeLoadString(v, target, 

  101010.                               aff ? azAff[aff-SQLITE_AFF_BLOB] : "none");

  101011.         return target;

  101012.       }

  101013. #endif

  101014. 

  101015.       for(i=0; i<nFarg; i++){

  101016.         if( i<32 && sqlite3ExprIsConstant(pFarg->a[i].pExpr) ){

  101017.           testcase( i==31 );

  101018.           constMask |= MASKBIT32(i);

  101019.         }

  101020.         if( (pDef->funcFlags & SQLITE_FUNC_NEEDCOLL)!=0 && !pColl ){

  101021.           pColl = sqlite3ExprCollSeq(pParse, pFarg->a[i].pExpr);

  101022.         }

  101023.       }

  101024.       if( pFarg ){

  101025.         if( constMask ){

  101026.           r1 = pParse->nMem+1;

  101027.           pParse->nMem += nFarg;

  101028.         }else{

  101029.           r1 = sqlite3GetTempRange(pParse, nFarg);

  101030.         }

  101031. 

  101032.         /* For length() and typeof() functions with a column argument,

  101033.         ** set the P5 parameter to the OP_Column opcode to OPFLAG_LENGTHARG

  101034.         ** or OPFLAG_TYPEOFARG respectively, to avoid unnecessary data

  101035.         ** loading.

  101036.         */

  101037.         if( (pDef->funcFlags & (SQLITE_FUNC_LENGTH|SQLITE_FUNC_TYPEOF))!=0 ){

  101038.           u8 exprOp;

  101039.           assert( nFarg==1 );

  101040.           assert( pFarg->a[0].pExpr!=0 );

  101041.           exprOp = pFarg->a[0].pExpr->op;

  101042.           if( exprOp==TK_COLUMN || exprOp==TK_AGG_COLUMN ){

  101043.             assert( SQLITE_FUNC_LENGTH==OPFLAG_LENGTHARG );

  101044.             assert( SQLITE_FUNC_TYPEOF==OPFLAG_TYPEOFARG );

  101045.             testcase( pDef->funcFlags & OPFLAG_LENGTHARG );

  101046.             pFarg->a[0].pExpr->op2 = 

  101047.                   pDef->funcFlags & (OPFLAG_LENGTHARG|OPFLAG_TYPEOFARG);

  101048.           }

  101049.         }

  101050. 

  101051.         sqlite3ExprCodeExprList(pParse, pFarg, r1, 0,

  101052.                                 SQLITE_ECEL_DUP|SQLITE_ECEL_FACTOR);

  101053.       }else{

  101054.         r1 = 0;

  101055.       }

  101056. #ifndef SQLITE_OMIT_VIRTUALTABLE

  101057.       /* Possibly overload the function if the first argument is

  101058.       ** a virtual table column.

  101059.       **

  101060.       ** For infix functions (LIKE, GLOB, REGEXP, and MATCH) use the

  101061.       ** second argument, not the first, as the argument to test to

  101062.       ** see if it is a column in a virtual table.  This is done because

  101063.       ** the left operand of infix functions (the operand we want to

  101064.       ** control overloading) ends up as the second argument to the

  101065.       ** function.  The expression "A glob B" is equivalent to 

  101066.       ** "glob(B,A).  We want to use the A in "A glob B" to test

  101067.       ** for function overloading.  But we use the B term in "glob(B,A)".

  101068.       */

  101069.       if( nFarg>=2 && ExprHasProperty(pExpr, EP_InfixFunc) ){

  101070.         pDef = sqlite3VtabOverloadFunction(db, pDef, nFarg, pFarg->a[1].pExpr);

  101071.       }else if( nFarg>0 ){

  101072.         pDef = sqlite3VtabOverloadFunction(db, pDef, nFarg, pFarg->a[0].pExpr);

  101073.       }

  101074. #endif

  101075.       if( pDef->funcFlags & SQLITE_FUNC_NEEDCOLL ){

  101076.         if( !pColl ) pColl = db->pDfltColl; 

  101077.         sqlite3VdbeAddOp4(v, OP_CollSeq, 0, 0, 0, (char *)pColl, P4_COLLSEQ);

  101078.       }

  101079. #ifdef SQLITE_ENABLE_OFFSET_SQL_FUNC

  101080.       if( pDef->funcFlags & SQLITE_FUNC_OFFSET ){

  101081.         Expr *pArg = pFarg->a[0].pExpr;

  101082.         if( pArg->op==TK_COLUMN ){

  101083.           sqlite3VdbeAddOp3(v, OP_Offset, pArg->iTable, pArg->iColumn, target);

  101084.         }else{

  101085.           sqlite3VdbeAddOp2(v, OP_Null, 0, target);

  101086.         }

  101087.       }else

  101088. #endif

  101089.       {

  101090.         sqlite3VdbeAddOp4(v, pParse->iSelfTab ? OP_PureFunc0 : OP_Function0,

  101091.                           constMask, r1, target, (char*)pDef, P4_FUNCDEF);

  101092.         sqlite3VdbeChangeP5(v, (u8)nFarg);

  101093.       }

  101094.       if( nFarg && constMask==0 ){

  101095.         sqlite3ReleaseTempRange(pParse, r1, nFarg);

  101096.       }

  101097.       return target;

  101098.     }

  101099. #ifndef SQLITE_OMIT_SUBQUERY

  101100.     case TK_EXISTS:

  101101.     case TK_SELECT: {

  101102.       int nCol;

  101103.       testcase( op==TK_EXISTS );

  101104.       testcase( op==TK_SELECT );

  101105.       if( op==TK_SELECT && (nCol = pExpr->x.pSelect->pEList->nExpr)!=1 ){

  101106.         sqlite3SubselectError(pParse, nCol, 1);

  101107.       }else{

  101108.         return sqlite3CodeSubselect(pParse, pExpr);

  101109.       }

  101110.       break;

  101111.     }

  101112.     case TK_SELECT_COLUMN: {

  101113.       int n;

  101114.       if( pExpr->pLeft->iTable==0 ){

  101115.         pExpr->pLeft->iTable = sqlite3CodeSubselect(pParse, pExpr->pLeft);

  101116.       }

  101117.       assert( pExpr->iTable==0 || pExpr->pLeft->op==TK_SELECT );

  101118.       if( pExpr->iTable

  101119.        && pExpr->iTable!=(n = sqlite3ExprVectorSize(pExpr->pLeft)) 

  101120.       ){

  101121.         sqlite3ErrorMsg(pParse, "%d columns assigned %d values",

  101122.                                 pExpr->iTable, n);

  101123.       }

  101124.       return pExpr->pLeft->iTable + pExpr->iColumn;

  101125.     }

  101126.     case TK_IN: {

  101127.       int destIfFalse = sqlite3VdbeMakeLabel(pParse);

  101128.       int destIfNull = sqlite3VdbeMakeLabel(pParse);

  101129.       sqlite3VdbeAddOp2(v, OP_Null, 0, target);

  101130.       sqlite3ExprCodeIN(pParse, pExpr, destIfFalse, destIfNull);

  101131.       sqlite3VdbeAddOp2(v, OP_Integer, 1, target);

  101132.       sqlite3VdbeResolveLabel(v, destIfFalse);

  101133.       sqlite3VdbeAddOp2(v, OP_AddImm, target, 0);

  101134.       sqlite3VdbeResolveLabel(v, destIfNull);

  101135.       return target;

  101136.     }

  101137. #endif /* SQLITE_OMIT_SUBQUERY */

  101138. 

  101139. 

  101140.     /*

  101141.     **    x BETWEEN y AND z

  101142.     **

  101143.     ** This is equivalent to

  101144.     **

  101145.     **    x>=y AND x<=z

  101146.     **

  101147.     ** X is stored in pExpr->pLeft.

  101148.     ** Y is stored in pExpr->pList->a[0].pExpr.

  101149.     ** Z is stored in pExpr->pList->a[1].pExpr.

  101150.     */

  101151.     case TK_BETWEEN: {

  101152.       exprCodeBetween(pParse, pExpr, target, 0, 0);

  101153.       return target;

  101154.     }

  101155.     case TK_SPAN:

  101156.     case TK_COLLATE: 

  101157.     case TK_UPLUS: {

  101158.       pExpr = pExpr->pLeft;

  101159.       goto expr_code_doover; /* 2018-04-28: Prevent deep recursion. OSSFuzz. */

  101160.     }

  101161. 

  101162.     case TK_TRIGGER: {

  101163.       /* If the opcode is TK_TRIGGER, then the expression is a reference

  101164.       ** to a column in the new.* or old.* pseudo-tables available to

  101165.       ** trigger programs. In this case Expr.iTable is set to 1 for the

  101166.       ** new.* pseudo-table, or 0 for the old.* pseudo-table. Expr.iColumn

  101167.       ** is set to the column of the pseudo-table to read, or to -1 to

  101168.       ** read the rowid field.

  101169.       **

  101170.       ** The expression is implemented using an OP_Param opcode. The p1

  101171.       ** parameter is set to 0 for an old.rowid reference, or to (i+1)

  101172.       ** to reference another column of the old.* pseudo-table, where 

  101173.       ** i is the index of the column. For a new.rowid reference, p1 is

  101174.       ** set to (n+1), where n is the number of columns in each pseudo-table.

  101175.       ** For a reference to any other column in the new.* pseudo-table, p1

  101176.       ** is set to (n+2+i), where n and i are as defined previously. For

  101177.       ** example, if the table on which triggers are being fired is

  101178.       ** declared as:

  101179.       **

  101180.       **   CREATE TABLE t1(a, b);

  101181.       **

  101182.       ** Then p1 is interpreted as follows:

  101183.       **

  101184.       **   p1==0   ->    old.rowid     p1==3   ->    new.rowid

  101185.       **   p1==1   ->    old.a         p1==4   ->    new.a

  101186.       **   p1==2   ->    old.b         p1==5   ->    new.b       

  101187.       */

  101188.       Table *pTab = pExpr->y.pTab;

  101189.       int p1 = pExpr->iTable * (pTab->nCol+1) + 1 + pExpr->iColumn;

  101190. 

  101191.       assert( pExpr->iTable==0 || pExpr->iTable==1 );

  101192.       assert( pExpr->iColumn>=-1 && pExpr->iColumn<pTab->nCol );

  101193.       assert( pTab->iPKey<0 || pExpr->iColumn!=pTab->iPKey );

  101194.       assert( p1>=0 && p1<(pTab->nCol*2+2) );

  101195. 

  101196.       sqlite3VdbeAddOp2(v, OP_Param, p1, target);

  101197.       VdbeComment((v, "r[%d]=%s.%s", target,

  101198.         (pExpr->iTable ? "new" : "old"),

  101199.         (pExpr->iColumn<0 ? "rowid" : pExpr->y.pTab->aCol[pExpr->iColumn].zName)

  101200.       ));

  101201. 

  101202. #ifndef SQLITE_OMIT_FLOATING_POINT

  101203.       /* If the column has REAL affinity, it may currently be stored as an

  101204.       ** integer. Use OP_RealAffinity to make sure it is really real.

  101205.       **

  101206.       ** EVIDENCE-OF: R-60985-57662 SQLite will convert the value back to

  101207.       ** floating point when extracting it from the record.  */

  101208.       if( pExpr->iColumn>=0 

  101209.        && pTab->aCol[pExpr->iColumn].affinity==SQLITE_AFF_REAL

  101210.       ){

  101211.         sqlite3VdbeAddOp1(v, OP_RealAffinity, target);

  101212.       }

  101213. #endif

  101214.       break;

  101215.     }

  101216. 

  101217.     case TK_VECTOR: {

  101218.       sqlite3ErrorMsg(pParse, "row value misused");

  101219.       break;

  101220.     }

  101221. 

  101222.     case TK_IF_NULL_ROW: {

  101223.       int addrINR;

  101224.       addrINR = sqlite3VdbeAddOp1(v, OP_IfNullRow, pExpr->iTable);

  101225.       inReg = sqlite3ExprCodeTarget(pParse, pExpr->pLeft, target);

  101226.       sqlite3VdbeJumpHere(v, addrINR);

  101227.       sqlite3VdbeChangeP3(v, addrINR, inReg);

  101228.       break;

  101229.     }

  101230. 

  101231.     /*

  101232.     ** Form A:

  101233.     **   CASE x WHEN e1 THEN r1 WHEN e2 THEN r2 ... WHEN eN THEN rN ELSE y END

  101234.     **

  101235.     ** Form B:

  101236.     **   CASE WHEN e1 THEN r1 WHEN e2 THEN r2 ... WHEN eN THEN rN ELSE y END

  101237.     **

  101238.     ** Form A is can be transformed into the equivalent form B as follows:

  101239.     **   CASE WHEN x=e1 THEN r1 WHEN x=e2 THEN r2 ...

  101240.     **        WHEN x=eN THEN rN ELSE y END

  101241.     **

  101242.     ** X (if it exists) is in pExpr->pLeft.

  101243.     ** Y is in the last element of pExpr->x.pList if pExpr->x.pList->nExpr is

  101244.     ** odd.  The Y is also optional.  If the number of elements in x.pList

  101245.     ** is even, then Y is omitted and the "otherwise" result is NULL.

  101246.     ** Ei is in pExpr->pList->a[i*2] and Ri is pExpr->pList->a[i*2+1].

  101247.     **

  101248.     ** The result of the expression is the Ri for the first matching Ei,

  101249.     ** or if there is no matching Ei, the ELSE term Y, or if there is

  101250.     ** no ELSE term, NULL.

  101251.     */

  101252.     default: assert( op==TK_CASE ); {

  101253.       int endLabel;                     /* GOTO label for end of CASE stmt */

  101254.       int nextCase;                     /* GOTO label for next WHEN clause */

  101255.       int nExpr;                        /* 2x number of WHEN terms */

  101256.       int i;                            /* Loop counter */

  101257.       ExprList *pEList;                 /* List of WHEN terms */

  101258.       struct ExprList_item *aListelem;  /* Array of WHEN terms */

  101259.       Expr opCompare;                   /* The X==Ei expression */

  101260.       Expr *pX;                         /* The X expression */

  101261.       Expr *pTest = 0;                  /* X==Ei (form A) or just Ei (form B) */

  101262. 

  101263.       assert( !ExprHasProperty(pExpr, EP_xIsSelect) && pExpr->x.pList );

  101264.       assert(pExpr->x.pList->nExpr > 0);

  101265.       pEList = pExpr->x.pList;

  101266.       aListelem = pEList->a;

  101267.       nExpr = pEList->nExpr;

  101268.       endLabel = sqlite3VdbeMakeLabel(pParse);

  101269.       if( (pX = pExpr->pLeft)!=0 ){

  101270.         exprNodeCopy(&tempX, pX);

  101271.         testcase( pX->op==TK_COLUMN );

  101272.         exprToRegister(&tempX, exprCodeVector(pParse, &tempX, &regFree1));

  101273.         testcase( regFree1==0 );

  101274.         memset(&opCompare, 0, sizeof(opCompare));

  101275.         opCompare.op = TK_EQ;

  101276.         opCompare.pLeft = &tempX;

  101277.         pTest = &opCompare;

  101278.         /* Ticket b351d95f9cd5ef17e9d9dbae18f5ca8611190001:

  101279.         ** The value in regFree1 might get SCopy-ed into the file result.

  101280.         ** So make sure that the regFree1 register is not reused for other

  101281.         ** purposes and possibly overwritten.  */

  101282.         regFree1 = 0;

  101283.       }

  101284.       for(i=0; i<nExpr-1; i=i+2){

  101285.         if( pX ){

  101286.           assert( pTest!=0 );

  101287.           opCompare.pRight = aListelem[i].pExpr;

  101288.         }else{

  101289.           pTest = aListelem[i].pExpr;

  101290.         }

  101291.         nextCase = sqlite3VdbeMakeLabel(pParse);

  101292.         testcase( pTest->op==TK_COLUMN );

  101293.         sqlite3ExprIfFalse(pParse, pTest, nextCase, SQLITE_JUMPIFNULL);

  101294.         testcase( aListelem[i+1].pExpr->op==TK_COLUMN );

  101295.         sqlite3ExprCode(pParse, aListelem[i+1].pExpr, target);

  101296.         sqlite3VdbeGoto(v, endLabel);

  101297.         sqlite3VdbeResolveLabel(v, nextCase);

  101298.       }

  101299.       if( (nExpr&1)!=0 ){

  101300.         sqlite3ExprCode(pParse, pEList->a[nExpr-1].pExpr, target);

  101301.       }else{

  101302.         sqlite3VdbeAddOp2(v, OP_Null, 0, target);

  101303.       }

  101304.       sqlite3VdbeResolveLabel(v, endLabel);

  101305.       break;

  101306.     }

  101307. #ifndef SQLITE_OMIT_TRIGGER

  101308.     case TK_RAISE: {

  101309.       assert( pExpr->affinity==OE_Rollback 

  101310.            || pExpr->affinity==OE_Abort

  101311.            || pExpr->affinity==OE_Fail

  101312.            || pExpr->affinity==OE_Ignore

  101313.       );

  101314.       if( !pParse->pTriggerTab ){

  101315.         sqlite3ErrorMsg(pParse,

  101316.                        "RAISE() may only be used within a trigger-program");

  101317.         return 0;

  101318.       }

  101319.       if( pExpr->affinity==OE_Abort ){

  101320.         sqlite3MayAbort(pParse);

  101321.       }

  101322.       assert( !ExprHasProperty(pExpr, EP_IntValue) );

  101323.       if( pExpr->affinity==OE_Ignore ){

  101324.         sqlite3VdbeAddOp4(

  101325.             v, OP_Halt, SQLITE_OK, OE_Ignore, 0, pExpr->u.zToken,0);

  101326.         VdbeCoverage(v);

  101327.       }else{

  101328.         sqlite3HaltConstraint(pParse, SQLITE_CONSTRAINT_TRIGGER,

  101329.                               pExpr->affinity, pExpr->u.zToken, 0, 0);

  101330.       }

  101331. 

  101332.       break;

  101333.     }

  101334. #endif

  101335.   }

  101336.   sqlite3ReleaseTempReg(pParse, regFree1);

  101337.   sqlite3ReleaseTempReg(pParse, regFree2);

  101338.   return inReg;

  101339. }

  101340. 

  101341. /*

  101342. ** Factor out the code of the given expression to initialization time.

  101343. **

  101344. ** If regDest>=0 then the result is always stored in that register and the

  101345. ** result is not reusable.  If regDest<0 then this routine is free to 

  101346. ** store the value whereever it wants.  The register where the expression 

  101347. ** is stored is returned.  When regDest<0, two identical expressions will

  101348. ** code to the same register.

  101349. */

  101350. SQLITE_PRIVATE int sqlite3ExprCodeAtInit(

  101351.   Parse *pParse,    /* Parsing context */

  101352.   Expr *pExpr,      /* The expression to code when the VDBE initializes */

  101353.   int regDest       /* Store the value in this register */

  101354. ){

  101355.   ExprList *p;

  101356.   assert( ConstFactorOk(pParse) );

  101357.   p = pParse->pConstExpr;

  101358.   if( regDest<0 && p ){

  101359.     struct ExprList_item *pItem;

  101360.     int i;

  101361.     for(pItem=p->a, i=p->nExpr; i>0; pItem++, i--){

  101362.       if( pItem->reusable && sqlite3ExprCompare(0,pItem->pExpr,pExpr,-1)==0 ){

  101363.         return pItem->u.iConstExprReg;

  101364.       }

  101365.     }

  101366.   }

  101367.   pExpr = sqlite3ExprDup(pParse->db, pExpr, 0);

  101368.   p = sqlite3ExprListAppend(pParse, p, pExpr);

  101369.   if( p ){

  101370.      struct ExprList_item *pItem = &p->a[p->nExpr-1];

  101371.      pItem->reusable = regDest<0;

  101372.      if( regDest<0 ) regDest = ++pParse->nMem;

  101373.      pItem->u.iConstExprReg = regDest;

  101374.   }

  101375.   pParse->pConstExpr = p;

  101376.   return regDest;

  101377. }

  101378. 

  101379. /*

  101380. ** Generate code to evaluate an expression and store the results

  101381. ** into a register.  Return the register number where the results

  101382. ** are stored.

  101383. **

  101384. ** If the register is a temporary register that can be deallocated,

  101385. ** then write its number into *pReg.  If the result register is not

  101386. ** a temporary, then set *pReg to zero.

  101387. **

  101388. ** If pExpr is a constant, then this routine might generate this

  101389. ** code to fill the register in the initialization section of the

  101390. ** VDBE program, in order to factor it out of the evaluation loop.

  101391. */

  101392. SQLITE_PRIVATE int sqlite3ExprCodeTemp(Parse *pParse, Expr *pExpr, int *pReg){

  101393.   int r2;

  101394.   pExpr = sqlite3ExprSkipCollate(pExpr);

  101395.   if( ConstFactorOk(pParse)

  101396.    && pExpr->op!=TK_REGISTER

  101397.    && sqlite3ExprIsConstantNotJoin(pExpr)

  101398.   ){

  101399.     *pReg  = 0;

  101400.     r2 = sqlite3ExprCodeAtInit(pParse, pExpr, -1);

  101401.   }else{

  101402.     int r1 = sqlite3GetTempReg(pParse);

  101403.     r2 = sqlite3ExprCodeTarget(pParse, pExpr, r1);

  101404.     if( r2==r1 ){

  101405.       *pReg = r1;

  101406.     }else{

  101407.       sqlite3ReleaseTempReg(pParse, r1);

  101408.       *pReg = 0;

  101409.     }

  101410.   }

  101411.   return r2;

  101412. }

  101413. 

  101414. /*

  101415. ** Generate code that will evaluate expression pExpr and store the

  101416. ** results in register target.  The results are guaranteed to appear

  101417. ** in register target.

  101418. */

  101419. SQLITE_PRIVATE void sqlite3ExprCode(Parse *pParse, Expr *pExpr, int target){

  101420.   int inReg;

  101421. 

  101422.   assert( target>0 && target<=pParse->nMem );

  101423.   if( pExpr && pExpr->op==TK_REGISTER ){

  101424.     sqlite3VdbeAddOp2(pParse->pVdbe, OP_Copy, pExpr->iTable, target);

  101425.   }else{

  101426.     inReg = sqlite3ExprCodeTarget(pParse, pExpr, target);

  101427.     assert( pParse->pVdbe!=0 || pParse->db->mallocFailed );

  101428.     if( inReg!=target && pParse->pVdbe ){

  101429.       sqlite3VdbeAddOp2(pParse->pVdbe, OP_SCopy, inReg, target);

  101430.     }

  101431.   }

  101432. }

  101433. 

  101434. /*

  101435. ** Make a transient copy of expression pExpr and then code it using

  101436. ** sqlite3ExprCode().  This routine works just like sqlite3ExprCode()

  101437. ** except that the input expression is guaranteed to be unchanged.

  101438. */

  101439. SQLITE_PRIVATE void sqlite3ExprCodeCopy(Parse *pParse, Expr *pExpr, int target){

  101440.   sqlite3 *db = pParse->db;

  101441.   pExpr = sqlite3ExprDup(db, pExpr, 0);

  101442.   if( !db->mallocFailed ) sqlite3ExprCode(pParse, pExpr, target);

  101443.   sqlite3ExprDelete(db, pExpr);

  101444. }

  101445. 

  101446. /*

  101447. ** Generate code that will evaluate expression pExpr and store the

  101448. ** results in register target.  The results are guaranteed to appear

  101449. ** in register target.  If the expression is constant, then this routine

  101450. ** might choose to code the expression at initialization time.

  101451. */

  101452. SQLITE_PRIVATE void sqlite3ExprCodeFactorable(Parse *pParse, Expr *pExpr, int target){

  101453.   if( pParse->okConstFactor && sqlite3ExprIsConstantNotJoin(pExpr) ){

  101454.     sqlite3ExprCodeAtInit(pParse, pExpr, target);

  101455.   }else{

  101456.     sqlite3ExprCode(pParse, pExpr, target);

  101457.   }

  101458. }

  101459. 

  101460. /*

  101461. ** Generate code that evaluates the given expression and puts the result

  101462. ** in register target.

  101463. **

  101464. ** Also make a copy of the expression results into another "cache" register

  101465. ** and modify the expression so that the next time it is evaluated,

  101466. ** the result is a copy of the cache register.

  101467. **

  101468. ** This routine is used for expressions that are used multiple 

  101469. ** times.  They are evaluated once and the results of the expression

  101470. ** are reused.

  101471. */

  101472. SQLITE_PRIVATE void sqlite3ExprCodeAndCache(Parse *pParse, Expr *pExpr, int target){

  101473.   Vdbe *v = pParse->pVdbe;

  101474.   int iMem;

  101475. 

  101476.   assert( target>0 );

  101477.   assert( pExpr->op!=TK_REGISTER );

  101478.   sqlite3ExprCode(pParse, pExpr, target);

  101479.   iMem = ++pParse->nMem;

  101480.   sqlite3VdbeAddOp2(v, OP_Copy, target, iMem);

  101481.   exprToRegister(pExpr, iMem);

  101482. }

  101483. 

  101484. /*

  101485. ** Generate code that pushes the value of every element of the given

  101486. ** expression list into a sequence of registers beginning at target.

  101487. **

  101488. ** Return the number of elements evaluated.  The number returned will

  101489. ** usually be pList->nExpr but might be reduced if SQLITE_ECEL_OMITREF

  101490. ** is defined.

  101491. **

  101492. ** The SQLITE_ECEL_DUP flag prevents the arguments from being

  101493. ** filled using OP_SCopy.  OP_Copy must be used instead.

  101494. **

  101495. ** The SQLITE_ECEL_FACTOR argument allows constant arguments to be

  101496. ** factored out into initialization code.

  101497. **

  101498. ** The SQLITE_ECEL_REF flag means that expressions in the list with

  101499. ** ExprList.a[].u.x.iOrderByCol>0 have already been evaluated and stored

  101500. ** in registers at srcReg, and so the value can be copied from there.

  101501. ** If SQLITE_ECEL_OMITREF is also set, then the values with u.x.iOrderByCol>0

  101502. ** are simply omitted rather than being copied from srcReg.

  101503. */

  101504. SQLITE_PRIVATE int sqlite3ExprCodeExprList(

  101505.   Parse *pParse,     /* Parsing context */

  101506.   ExprList *pList,   /* The expression list to be coded */

  101507.   int target,        /* Where to write results */

  101508.   int srcReg,        /* Source registers if SQLITE_ECEL_REF */

  101509.   u8 flags           /* SQLITE_ECEL_* flags */

  101510. ){

  101511.   struct ExprList_item *pItem;

  101512.   int i, j, n;

  101513.   u8 copyOp = (flags & SQLITE_ECEL_DUP) ? OP_Copy : OP_SCopy;

  101514.   Vdbe *v = pParse->pVdbe;

  101515.   assert( pList!=0 );

  101516.   assert( target>0 );

  101517.   assert( pParse->pVdbe!=0 );  /* Never gets this far otherwise */

  101518.   n = pList->nExpr;

  101519.   if( !ConstFactorOk(pParse) ) flags &= ~SQLITE_ECEL_FACTOR;

  101520.   for(pItem=pList->a, i=0; i<n; i++, pItem++){

  101521.     Expr *pExpr = pItem->pExpr;

  101522. #ifdef SQLITE_ENABLE_SORTER_REFERENCES

  101523.     if( pItem->bSorterRef ){

  101524.       i--;

  101525.       n--;

  101526.     }else

  101527. #endif

  101528.     if( (flags & SQLITE_ECEL_REF)!=0 && (j = pItem->u.x.iOrderByCol)>0 ){

  101529.       if( flags & SQLITE_ECEL_OMITREF ){

  101530.         i--;

  101531.         n--;

  101532.       }else{

  101533.         sqlite3VdbeAddOp2(v, copyOp, j+srcReg-1, target+i);

  101534.       }

  101535.     }else if( (flags & SQLITE_ECEL_FACTOR)!=0

  101536.            && sqlite3ExprIsConstantNotJoin(pExpr)

  101537.     ){

  101538.       sqlite3ExprCodeAtInit(pParse, pExpr, target+i);

  101539.     }else{

  101540.       int inReg = sqlite3ExprCodeTarget(pParse, pExpr, target+i);

  101541.       if( inReg!=target+i ){

  101542.         VdbeOp *pOp;

  101543.         if( copyOp==OP_Copy

  101544.          && (pOp=sqlite3VdbeGetOp(v, -1))->opcode==OP_Copy

  101545.          && pOp->p1+pOp->p3+1==inReg

  101546.          && pOp->p2+pOp->p3+1==target+i

  101547.         ){

  101548.           pOp->p3++;

  101549.         }else{

  101550.           sqlite3VdbeAddOp2(v, copyOp, inReg, target+i);

  101551.         }

  101552.       }

  101553.     }

  101554.   }

  101555.   return n;

  101556. }

  101557. 

  101558. /*

  101559. ** Generate code for a BETWEEN operator.

  101560. **

  101561. **    x BETWEEN y AND z

  101562. **

  101563. ** The above is equivalent to 

  101564. **

  101565. **    x>=y AND x<=z

  101566. **

  101567. ** Code it as such, taking care to do the common subexpression

  101568. ** elimination of x.

  101569. **

  101570. ** The xJumpIf parameter determines details:

  101571. **

  101572. **    NULL:                   Store the boolean result in reg[dest]

  101573. **    sqlite3ExprIfTrue:      Jump to dest if true

  101574. **    sqlite3ExprIfFalse:     Jump to dest if false

  101575. **

  101576. ** The jumpIfNull parameter is ignored if xJumpIf is NULL.

  101577. */

  101578. static void exprCodeBetween(

  101579.   Parse *pParse,    /* Parsing and code generating context */

  101580.   Expr *pExpr,      /* The BETWEEN expression */

  101581.   int dest,         /* Jump destination or storage location */

  101582.   void (*xJump)(Parse*,Expr*,int,int), /* Action to take */

  101583.   int jumpIfNull    /* Take the jump if the BETWEEN is NULL */

  101584. ){

  101585.  Expr exprAnd;     /* The AND operator in  x>=y AND x<=z  */

  101586.   Expr compLeft;    /* The  x>=y  term */

  101587.   Expr compRight;   /* The  x<=z  term */

  101588.   Expr exprX;       /* The  x  subexpression */

  101589.   int regFree1 = 0; /* Temporary use register */

  101590. 

  101591.   memset(&compLeft, 0, sizeof(Expr));

  101592.   memset(&compRight, 0, sizeof(Expr));

  101593.   memset(&exprAnd, 0, sizeof(Expr));

  101594. 

  101595.   assert( !ExprHasProperty(pExpr, EP_xIsSelect) );

  101596.   exprNodeCopy(&exprX, pExpr->pLeft);

  101597.   exprAnd.op = TK_AND;

  101598.   exprAnd.pLeft = &compLeft;

  101599.   exprAnd.pRight = &compRight;

  101600.   compLeft.op = TK_GE;

  101601.   compLeft.pLeft = &exprX;

  101602.   compLeft.pRight = pExpr->x.pList->a[0].pExpr;

  101603.   compRight.op = TK_LE;

  101604.   compRight.pLeft = &exprX;

  101605.   compRight.pRight = pExpr->x.pList->a[1].pExpr;

  101606.   exprToRegister(&exprX, exprCodeVector(pParse, &exprX, &regFree1));

  101607.   if( xJump ){

  101608.     xJump(pParse, &exprAnd, dest, jumpIfNull);

  101609.   }else{

  101610.     /* Mark the expression is being from the ON or USING clause of a join

  101611.     ** so that the sqlite3ExprCodeTarget() routine will not attempt to move

  101612.     ** it into the Parse.pConstExpr list.  We should use a new bit for this,

  101613.     ** for clarity, but we are out of bits in the Expr.flags field so we

  101614.     ** have to reuse the EP_FromJoin bit.  Bummer. */

  101615.     exprX.flags |= EP_FromJoin;

  101616.     sqlite3ExprCodeTarget(pParse, &exprAnd, dest);

  101617.   }

  101618.   sqlite3ReleaseTempReg(pParse, regFree1);

  101619. 

  101620.   /* Ensure adequate test coverage */

  101621.   testcase( xJump==sqlite3ExprIfTrue  && jumpIfNull==0 && regFree1==0 );

  101622.   testcase( xJump==sqlite3ExprIfTrue  && jumpIfNull==0 && regFree1!=0 );

  101623.   testcase( xJump==sqlite3ExprIfTrue  && jumpIfNull!=0 && regFree1==0 );

  101624.   testcase( xJump==sqlite3ExprIfTrue  && jumpIfNull!=0 && regFree1!=0 );

  101625.   testcase( xJump==sqlite3ExprIfFalse && jumpIfNull==0 && regFree1==0 );

  101626.   testcase( xJump==sqlite3ExprIfFalse && jumpIfNull==0 && regFree1!=0 );

  101627.   testcase( xJump==sqlite3ExprIfFalse && jumpIfNull!=0 && regFree1==0 );

  101628.   testcase( xJump==sqlite3ExprIfFalse && jumpIfNull!=0 && regFree1!=0 );

  101629.   testcase( xJump==0 );

  101630. }

  101631. 

  101632. /*

  101633. ** Generate code for a boolean expression such that a jump is made

  101634. ** to the label "dest" if the expression is true but execution

  101635. ** continues straight thru if the expression is false.

  101636. **

  101637. ** If the expression evaluates to NULL (neither true nor false), then

  101638. ** take the jump if the jumpIfNull flag is SQLITE_JUMPIFNULL.

  101639. **

  101640. ** This code depends on the fact that certain token values (ex: TK_EQ)

  101641. ** are the same as opcode values (ex: OP_Eq) that implement the corresponding

  101642. ** operation.  Special comments in vdbe.c and the mkopcodeh.awk script in

  101643. ** the make process cause these values to align.  Assert()s in the code

  101644. ** below verify that the numbers are aligned correctly.

  101645. */

  101646. SQLITE_PRIVATE void sqlite3ExprIfTrue(Parse *pParse, Expr *pExpr, int dest, int jumpIfNull){

  101647.   Vdbe *v = pParse->pVdbe;

  101648.   int op = 0;

  101649.   int regFree1 = 0;

  101650.   int regFree2 = 0;

  101651.   int r1, r2;

  101652. 

  101653.   assert( jumpIfNull==SQLITE_JUMPIFNULL || jumpIfNull==0 );

  101654.   if( NEVER(v==0) )     return;  /* Existence of VDBE checked by caller */

  101655.   if( NEVER(pExpr==0) ) return;  /* No way this can happen */

  101656.   op = pExpr->op;

  101657.   switch( op ){

  101658.     case TK_AND:

  101659.     case TK_OR: {

  101660.       Expr *pAlt = sqlite3ExprSimplifiedAndOr(pExpr);

  101661.       if( pAlt!=pExpr ){

  101662.         sqlite3ExprIfTrue(pParse, pAlt, dest, jumpIfNull);

  101663.       }else if( op==TK_AND ){

  101664.         int d2 = sqlite3VdbeMakeLabel(pParse);

  101665.         testcase( jumpIfNull==0 );

  101666.         sqlite3ExprIfFalse(pParse, pExpr->pLeft, d2,

  101667.                            jumpIfNull^SQLITE_JUMPIFNULL);

  101668.         sqlite3ExprIfTrue(pParse, pExpr->pRight, dest, jumpIfNull);

  101669.         sqlite3VdbeResolveLabel(v, d2);

  101670.       }else{

  101671.         testcase( jumpIfNull==0 );

  101672.         sqlite3ExprIfTrue(pParse, pExpr->pLeft, dest, jumpIfNull);

  101673.         sqlite3ExprIfTrue(pParse, pExpr->pRight, dest, jumpIfNull);

  101674.       }

  101675.       break;

  101676.     }

  101677.     case TK_NOT: {

  101678.       testcase( jumpIfNull==0 );

  101679.       sqlite3ExprIfFalse(pParse, pExpr->pLeft, dest, jumpIfNull);

  101680.       break;

  101681.     }

  101682.     case TK_TRUTH: {

  101683.       int isNot;      /* IS NOT TRUE or IS NOT FALSE */

  101684.       int isTrue;     /* IS TRUE or IS NOT TRUE */

  101685.       testcase( jumpIfNull==0 );

  101686.       isNot = pExpr->op2==TK_ISNOT;

  101687.       isTrue = sqlite3ExprTruthValue(pExpr->pRight);

  101688.       testcase( isTrue && isNot );

  101689.       testcase( !isTrue && isNot );

  101690.       if( isTrue ^ isNot ){

  101691.         sqlite3ExprIfTrue(pParse, pExpr->pLeft, dest,

  101692.                           isNot ? SQLITE_JUMPIFNULL : 0);

  101693.       }else{

  101694.         sqlite3ExprIfFalse(pParse, pExpr->pLeft, dest,

  101695.                            isNot ? SQLITE_JUMPIFNULL : 0);

  101696.       }

  101697.       break;

  101698.     }

  101699.     case TK_IS:

  101700.     case TK_ISNOT:

  101701.       testcase( op==TK_IS );

  101702.       testcase( op==TK_ISNOT );

  101703.       op = (op==TK_IS) ? TK_EQ : TK_NE;

  101704.       jumpIfNull = SQLITE_NULLEQ;

  101705.       /* Fall thru */

  101706.     case TK_LT:

  101707.     case TK_LE:

  101708.     case TK_GT:

  101709.     case TK_GE:

  101710.     case TK_NE:

  101711.     case TK_EQ: {

  101712.       if( sqlite3ExprIsVector(pExpr->pLeft) ) goto default_expr;

  101713.       testcase( jumpIfNull==0 );

  101714.       r1 = sqlite3ExprCodeTemp(pParse, pExpr->pLeft, &regFree1);

  101715.       r2 = sqlite3ExprCodeTemp(pParse, pExpr->pRight, &regFree2);

  101716.       codeCompare(pParse, pExpr->pLeft, pExpr->pRight, op,

  101717.                   r1, r2, dest, jumpIfNull);

  101718.       assert(TK_LT==OP_Lt); testcase(op==OP_Lt); VdbeCoverageIf(v,op==OP_Lt);

  101719.       assert(TK_LE==OP_Le); testcase(op==OP_Le); VdbeCoverageIf(v,op==OP_Le);

  101720.       assert(TK_GT==OP_Gt); testcase(op==OP_Gt); VdbeCoverageIf(v,op==OP_Gt);

  101721.       assert(TK_GE==OP_Ge); testcase(op==OP_Ge); VdbeCoverageIf(v,op==OP_Ge);

  101722.       assert(TK_EQ==OP_Eq); testcase(op==OP_Eq);

  101723.       VdbeCoverageIf(v, op==OP_Eq && jumpIfNull==SQLITE_NULLEQ);

  101724.       VdbeCoverageIf(v, op==OP_Eq && jumpIfNull!=SQLITE_NULLEQ);

  101725.       assert(TK_NE==OP_Ne); testcase(op==OP_Ne);

  101726.       VdbeCoverageIf(v, op==OP_Ne && jumpIfNull==SQLITE_NULLEQ);

  101727.       VdbeCoverageIf(v, op==OP_Ne && jumpIfNull!=SQLITE_NULLEQ);

  101728.       testcase( regFree1==0 );

  101729.       testcase( regFree2==0 );

  101730.       break;

  101731.     }

  101732.     case TK_ISNULL:

  101733.     case TK_NOTNULL: {

  101734.       assert( TK_ISNULL==OP_IsNull );   testcase( op==TK_ISNULL );

  101735.       assert( TK_NOTNULL==OP_NotNull ); testcase( op==TK_NOTNULL );

  101736.       r1 = sqlite3ExprCodeTemp(pParse, pExpr->pLeft, &regFree1);

  101737.       sqlite3VdbeAddOp2(v, op, r1, dest);

  101738.       VdbeCoverageIf(v, op==TK_ISNULL);

  101739.       VdbeCoverageIf(v, op==TK_NOTNULL);

  101740.       testcase( regFree1==0 );

  101741.       break;

  101742.     }

  101743.     case TK_BETWEEN: {

  101744.       testcase( jumpIfNull==0 );

  101745.       exprCodeBetween(pParse, pExpr, dest, sqlite3ExprIfTrue, jumpIfNull);

  101746.       break;

  101747.     }

  101748. #ifndef SQLITE_OMIT_SUBQUERY

  101749.     case TK_IN: {

  101750.       int destIfFalse = sqlite3VdbeMakeLabel(pParse);

  101751.       int destIfNull = jumpIfNull ? dest : destIfFalse;

  101752.       sqlite3ExprCodeIN(pParse, pExpr, destIfFalse, destIfNull);

  101753.       sqlite3VdbeGoto(v, dest);

  101754.       sqlite3VdbeResolveLabel(v, destIfFalse);

  101755.       break;

  101756.     }

  101757. #endif

  101758.     default: {

  101759.     default_expr:

  101760.       if( ExprAlwaysTrue(pExpr) ){

  101761.         sqlite3VdbeGoto(v, dest);

  101762.       }else if( ExprAlwaysFalse(pExpr) ){

  101763.         /* No-op */

  101764.       }else{

  101765.         r1 = sqlite3ExprCodeTemp(pParse, pExpr, &regFree1);

  101766.         sqlite3VdbeAddOp3(v, OP_If, r1, dest, jumpIfNull!=0);

  101767.         VdbeCoverage(v);

  101768.         testcase( regFree1==0 );

  101769.         testcase( jumpIfNull==0 );

  101770.       }

  101771.       break;

  101772.     }

  101773.   }

  101774.   sqlite3ReleaseTempReg(pParse, regFree1);

  101775.   sqlite3ReleaseTempReg(pParse, regFree2);  

  101776. }

  101777. 

  101778. /*

  101779. ** Generate code for a boolean expression such that a jump is made

  101780. ** to the label "dest" if the expression is false but execution

  101781. ** continues straight thru if the expression is true.

  101782. **

  101783. ** If the expression evaluates to NULL (neither true nor false) then

  101784. ** jump if jumpIfNull is SQLITE_JUMPIFNULL or fall through if jumpIfNull

  101785. ** is 0.

  101786. */

  101787. SQLITE_PRIVATE void sqlite3ExprIfFalse(Parse *pParse, Expr *pExpr, int dest, int jumpIfNull){

  101788.   Vdbe *v = pParse->pVdbe;

  101789.   int op = 0;

  101790.   int regFree1 = 0;

  101791.   int regFree2 = 0;

  101792.   int r1, r2;

  101793. 

  101794.   assert( jumpIfNull==SQLITE_JUMPIFNULL || jumpIfNull==0 );

  101795.   if( NEVER(v==0) ) return; /* Existence of VDBE checked by caller */

  101796.   if( pExpr==0 )    return;

  101797. 

  101798.   /* The value of pExpr->op and op are related as follows:

  101799.   **

  101800.   **       pExpr->op            op

  101801.   **       ---------          ----------

  101802.   **       TK_ISNULL          OP_NotNull

  101803.   **       TK_NOTNULL         OP_IsNull

  101804.   **       TK_NE              OP_Eq

  101805.   **       TK_EQ              OP_Ne

  101806.   **       TK_GT              OP_Le

  101807.   **       TK_LE              OP_Gt

  101808.   **       TK_GE              OP_Lt

  101809.   **       TK_LT              OP_Ge

  101810.   **

  101811.   ** For other values of pExpr->op, op is undefined and unused.

  101812.   ** The value of TK_ and OP_ constants are arranged such that we

  101813.   ** can compute the mapping above using the following expression.

  101814.   ** Assert()s verify that the computation is correct.

  101815.   */

  101816.   op = ((pExpr->op+(TK_ISNULL&1))^1)-(TK_ISNULL&1);

  101817. 

  101818.   /* Verify correct alignment of TK_ and OP_ constants

  101819.   */

  101820.   assert( pExpr->op!=TK_ISNULL || op==OP_NotNull );

  101821.   assert( pExpr->op!=TK_NOTNULL || op==OP_IsNull );

  101822.   assert( pExpr->op!=TK_NE || op==OP_Eq );

  101823.   assert( pExpr->op!=TK_EQ || op==OP_Ne );

  101824.   assert( pExpr->op!=TK_LT || op==OP_Ge );

  101825.   assert( pExpr->op!=TK_LE || op==OP_Gt );

  101826.   assert( pExpr->op!=TK_GT || op==OP_Le );

  101827.   assert( pExpr->op!=TK_GE || op==OP_Lt );

  101828. 

  101829.   switch( pExpr->op ){

  101830.     case TK_AND:

  101831.     case TK_OR: {

  101832.       Expr *pAlt = sqlite3ExprSimplifiedAndOr(pExpr);

  101833.       if( pAlt!=pExpr ){

  101834.         sqlite3ExprIfFalse(pParse, pAlt, dest, jumpIfNull);

  101835.       }else if( pExpr->op==TK_AND ){

  101836.         testcase( jumpIfNull==0 );

  101837.         sqlite3ExprIfFalse(pParse, pExpr->pLeft, dest, jumpIfNull);

  101838.         sqlite3ExprIfFalse(pParse, pExpr->pRight, dest, jumpIfNull);

  101839.       }else{

  101840.         int d2 = sqlite3VdbeMakeLabel(pParse);

  101841.         testcase( jumpIfNull==0 );

  101842.         sqlite3ExprIfTrue(pParse, pExpr->pLeft, d2,

  101843.                           jumpIfNull^SQLITE_JUMPIFNULL);

  101844.         sqlite3ExprIfFalse(pParse, pExpr->pRight, dest, jumpIfNull);

  101845.         sqlite3VdbeResolveLabel(v, d2);

  101846.       }

  101847.       break;

  101848.     }

  101849.     case TK_NOT: {

  101850.       testcase( jumpIfNull==0 );

  101851.       sqlite3ExprIfTrue(pParse, pExpr->pLeft, dest, jumpIfNull);

  101852.       break;

  101853.     }

  101854.     case TK_TRUTH: {

  101855.       int isNot;   /* IS NOT TRUE or IS NOT FALSE */

  101856.       int isTrue;  /* IS TRUE or IS NOT TRUE */

  101857.       testcase( jumpIfNull==0 );

  101858.       isNot = pExpr->op2==TK_ISNOT;

  101859.       isTrue = sqlite3ExprTruthValue(pExpr->pRight);

  101860.       testcase( isTrue && isNot );

  101861.       testcase( !isTrue && isNot );

  101862.       if( isTrue ^ isNot ){

  101863.         /* IS TRUE and IS NOT FALSE */

  101864.         sqlite3ExprIfFalse(pParse, pExpr->pLeft, dest,

  101865.                            isNot ? 0 : SQLITE_JUMPIFNULL);

  101866. 

  101867.       }else{

  101868.         /* IS FALSE and IS NOT TRUE */

  101869.         sqlite3ExprIfTrue(pParse, pExpr->pLeft, dest,

  101870.                           isNot ? 0 : SQLITE_JUMPIFNULL);

  101871.       }

  101872.       break;

  101873.     }

  101874.     case TK_IS:

  101875.     case TK_ISNOT:

  101876.       testcase( pExpr->op==TK_IS );

  101877.       testcase( pExpr->op==TK_ISNOT );

  101878.       op = (pExpr->op==TK_IS) ? TK_NE : TK_EQ;

  101879.       jumpIfNull = SQLITE_NULLEQ;

  101880.       /* Fall thru */

  101881.     case TK_LT:

  101882.     case TK_LE:

  101883.     case TK_GT:

  101884.     case TK_GE:

  101885.     case TK_NE:

  101886.     case TK_EQ: {

  101887.       if( sqlite3ExprIsVector(pExpr->pLeft) ) goto default_expr;

  101888.       testcase( jumpIfNull==0 );

  101889.       r1 = sqlite3ExprCodeTemp(pParse, pExpr->pLeft, &regFree1);

  101890.       r2 = sqlite3ExprCodeTemp(pParse, pExpr->pRight, &regFree2);

  101891.       codeCompare(pParse, pExpr->pLeft, pExpr->pRight, op,

  101892.                   r1, r2, dest, jumpIfNull);

  101893.       assert(TK_LT==OP_Lt); testcase(op==OP_Lt); VdbeCoverageIf(v,op==OP_Lt);

  101894.       assert(TK_LE==OP_Le); testcase(op==OP_Le); VdbeCoverageIf(v,op==OP_Le);

  101895.       assert(TK_GT==OP_Gt); testcase(op==OP_Gt); VdbeCoverageIf(v,op==OP_Gt);

  101896.       assert(TK_GE==OP_Ge); testcase(op==OP_Ge); VdbeCoverageIf(v,op==OP_Ge);

  101897.       assert(TK_EQ==OP_Eq); testcase(op==OP_Eq);

  101898.       VdbeCoverageIf(v, op==OP_Eq && jumpIfNull!=SQLITE_NULLEQ);

  101899.       VdbeCoverageIf(v, op==OP_Eq && jumpIfNull==SQLITE_NULLEQ);

  101900.       assert(TK_NE==OP_Ne); testcase(op==OP_Ne);

  101901.       VdbeCoverageIf(v, op==OP_Ne && jumpIfNull!=SQLITE_NULLEQ);

  101902.       VdbeCoverageIf(v, op==OP_Ne && jumpIfNull==SQLITE_NULLEQ);

  101903.       testcase( regFree1==0 );

  101904.       testcase( regFree2==0 );

  101905.       break;

  101906.     }

  101907.     case TK_ISNULL:

  101908.     case TK_NOTNULL: {

  101909.       r1 = sqlite3ExprCodeTemp(pParse, pExpr->pLeft, &regFree1);

  101910.       sqlite3VdbeAddOp2(v, op, r1, dest);

  101911.       testcase( op==TK_ISNULL );   VdbeCoverageIf(v, op==TK_ISNULL);

  101912.       testcase( op==TK_NOTNULL );  VdbeCoverageIf(v, op==TK_NOTNULL);

  101913.       testcase( regFree1==0 );

  101914.       break;

  101915.     }

  101916.     case TK_BETWEEN: {

  101917.       testcase( jumpIfNull==0 );

  101918.       exprCodeBetween(pParse, pExpr, dest, sqlite3ExprIfFalse, jumpIfNull);

  101919.       break;

  101920.     }

  101921. #ifndef SQLITE_OMIT_SUBQUERY

  101922.     case TK_IN: {

  101923.       if( jumpIfNull ){

  101924.         sqlite3ExprCodeIN(pParse, pExpr, dest, dest);

  101925.       }else{

  101926.         int destIfNull = sqlite3VdbeMakeLabel(pParse);

  101927.         sqlite3ExprCodeIN(pParse, pExpr, dest, destIfNull);

  101928.         sqlite3VdbeResolveLabel(v, destIfNull);

  101929.       }

  101930.       break;

  101931.     }

  101932. #endif

  101933.     default: {

  101934.     default_expr: 

  101935.       if( ExprAlwaysFalse(pExpr) ){

  101936.         sqlite3VdbeGoto(v, dest);

  101937.       }else if( ExprAlwaysTrue(pExpr) ){

  101938.         /* no-op */

  101939.       }else{

  101940.         r1 = sqlite3ExprCodeTemp(pParse, pExpr, &regFree1);

  101941.         sqlite3VdbeAddOp3(v, OP_IfNot, r1, dest, jumpIfNull!=0);

  101942.         VdbeCoverage(v);

  101943.         testcase( regFree1==0 );

  101944.         testcase( jumpIfNull==0 );

  101945.       }

  101946.       break;

  101947.     }

  101948.   }

  101949.   sqlite3ReleaseTempReg(pParse, regFree1);

  101950.   sqlite3ReleaseTempReg(pParse, regFree2);

  101951. }

  101952. 

  101953. /*

  101954. ** Like sqlite3ExprIfFalse() except that a copy is made of pExpr before

  101955. ** code generation, and that copy is deleted after code generation. This

  101956. ** ensures that the original pExpr is unchanged.

  101957. */

  101958. SQLITE_PRIVATE void sqlite3ExprIfFalseDup(Parse *pParse, Expr *pExpr, int dest,int jumpIfNull){

  101959.   sqlite3 *db = pParse->db;

  101960.   Expr *pCopy = sqlite3ExprDup(db, pExpr, 0);

  101961.   if( db->mallocFailed==0 ){

  101962.     sqlite3ExprIfFalse(pParse, pCopy, dest, jumpIfNull);

  101963.   }

  101964.   sqlite3ExprDelete(db, pCopy);

  101965. }

  101966. 

  101967. /*

  101968. ** Expression pVar is guaranteed to be an SQL variable. pExpr may be any

  101969. ** type of expression.

  101970. **

  101971. ** If pExpr is a simple SQL value - an integer, real, string, blob

  101972. ** or NULL value - then the VDBE currently being prepared is configured

  101973. ** to re-prepare each time a new value is bound to variable pVar.

  101974. **

  101975. ** Additionally, if pExpr is a simple SQL value and the value is the

  101976. ** same as that currently bound to variable pVar, non-zero is returned.

  101977. ** Otherwise, if the values are not the same or if pExpr is not a simple

  101978. ** SQL value, zero is returned.

  101979. */

  101980. static int exprCompareVariable(Parse *pParse, Expr *pVar, Expr *pExpr){

  101981.   int res = 0;

  101982.   int iVar;

  101983.   sqlite3_value *pL, *pR = 0;

  101984.   

  101985.   sqlite3ValueFromExpr(pParse->db, pExpr, SQLITE_UTF8, SQLITE_AFF_BLOB, &pR);

  101986.   if( pR ){

  101987.     iVar = pVar->iColumn;

  101988.     sqlite3VdbeSetVarmask(pParse->pVdbe, iVar);

  101989.     pL = sqlite3VdbeGetBoundValue(pParse->pReprepare, iVar, SQLITE_AFF_BLOB);

  101990.     if( pL ){

  101991.       if( sqlite3_value_type(pL)==SQLITE_TEXT ){

  101992.         sqlite3_value_text(pL); /* Make sure the encoding is UTF-8 */

  101993.       }

  101994.       res =  0==sqlite3MemCompare(pL, pR, 0);

  101995.     }

  101996.     sqlite3ValueFree(pR);

  101997.     sqlite3ValueFree(pL);

  101998.   }

  101999. 

  102000.   return res;

  102001. }

  102002. 

  102003. /*

  102004. ** Do a deep comparison of two expression trees.  Return 0 if the two

  102005. ** expressions are completely identical.  Return 1 if they differ only

  102006. ** by a COLLATE operator at the top level.  Return 2 if there are differences

  102007. ** other than the top-level COLLATE operator.

  102008. **

  102009. ** If any subelement of pB has Expr.iTable==(-1) then it is allowed

  102010. ** to compare equal to an equivalent element in pA with Expr.iTable==iTab.

  102011. **

  102012. ** The pA side might be using TK_REGISTER.  If that is the case and pB is

  102013. ** not using TK_REGISTER but is otherwise equivalent, then still return 0.

  102014. **

  102015. ** Sometimes this routine will return 2 even if the two expressions

  102016. ** really are equivalent.  If we cannot prove that the expressions are

  102017. ** identical, we return 2 just to be safe.  So if this routine

  102018. ** returns 2, then you do not really know for certain if the two

  102019. ** expressions are the same.  But if you get a 0 or 1 return, then you

  102020. ** can be sure the expressions are the same.  In the places where

  102021. ** this routine is used, it does not hurt to get an extra 2 - that

  102022. ** just might result in some slightly slower code.  But returning

  102023. ** an incorrect 0 or 1 could lead to a malfunction.

  102024. **

  102025. ** If pParse is not NULL then TK_VARIABLE terms in pA with bindings in

  102026. ** pParse->pReprepare can be matched against literals in pB.  The 

  102027. ** pParse->pVdbe->expmask bitmask is updated for each variable referenced.

  102028. ** If pParse is NULL (the normal case) then any TK_VARIABLE term in 

  102029. ** Argument pParse should normally be NULL. If it is not NULL and pA or

  102030. ** pB causes a return value of 2.

  102031. */

  102032. SQLITE_PRIVATE int sqlite3ExprCompare(Parse *pParse, Expr *pA, Expr *pB, int iTab){

  102033.   u32 combinedFlags;

  102034.   if( pA==0 || pB==0 ){

  102035.     return pB==pA ? 0 : 2;

  102036.   }

  102037.   if( pParse && pA->op==TK_VARIABLE && exprCompareVariable(pParse, pA, pB) ){

  102038.     return 0;

  102039.   }

  102040.   combinedFlags = pA->flags | pB->flags;

  102041.   if( combinedFlags & EP_IntValue ){

  102042.     if( (pA->flags&pB->flags&EP_IntValue)!=0 && pA->u.iValue==pB->u.iValue ){

  102043.       return 0;

  102044.     }

  102045.     return 2;

  102046.   }

  102047.   if( pA->op!=pB->op || pA->op==TK_RAISE ){

  102048.     if( pA->op==TK_COLLATE && sqlite3ExprCompare(pParse, pA->pLeft,pB,iTab)<2 ){

  102049.       return 1;

  102050.     }

  102051.     if( pB->op==TK_COLLATE && sqlite3ExprCompare(pParse, pA,pB->pLeft,iTab)<2 ){

  102052.       return 1;

  102053.     }

  102054.     return 2;

  102055.   }

  102056.   if( pA->op!=TK_COLUMN && pA->op!=TK_AGG_COLUMN && pA->u.zToken ){

  102057.     if( pA->op==TK_FUNCTION ){

  102058.       if( sqlite3StrICmp(pA->u.zToken,pB->u.zToken)!=0 ) return 2;

  102059. #ifndef SQLITE_OMIT_WINDOWFUNC

  102060.       /* Justification for the assert():

  102061.       ** window functions have p->op==TK_FUNCTION but aggregate functions

  102062.       ** have p->op==TK_AGG_FUNCTION.  So any comparison between an aggregate

  102063.       ** function and a window function should have failed before reaching

  102064.       ** this point.  And, it is not possible to have a window function and

  102065.       ** a scalar function with the same name and number of arguments.  So

  102066.       ** if we reach this point, either A and B both window functions or

  102067.       ** neither are a window functions. */

  102068.       assert( ExprHasProperty(pA,EP_WinFunc)==ExprHasProperty(pB,EP_WinFunc) );

  102069.       if( ExprHasProperty(pA,EP_WinFunc) ){

  102070.         if( sqlite3WindowCompare(pParse,pA->y.pWin,pB->y.pWin)!=0 ) return 2;

  102071.       }

  102072. #endif

  102073.     }else if( pA->op==TK_NULL ){

  102074.       return 0;

  102075.     }else if( pA->op==TK_COLLATE ){

  102076.       if( sqlite3_stricmp(pA->u.zToken,pB->u.zToken)!=0 ) return 2;

  102077.     }else if( ALWAYS(pB->u.zToken!=0) && strcmp(pA->u.zToken,pB->u.zToken)!=0 ){

  102078.       return 2;

  102079.     }

  102080.   }

  102081.   if( (pA->flags & EP_Distinct)!=(pB->flags & EP_Distinct) ) return 2;

  102082.   if( (combinedFlags & EP_TokenOnly)==0 ){

  102083.     if( combinedFlags & EP_xIsSelect ) return 2;

  102084.     if( (combinedFlags & EP_FixedCol)==0

  102085.      && sqlite3ExprCompare(pParse, pA->pLeft, pB->pLeft, iTab) ) return 2;

  102086.     if( sqlite3ExprCompare(pParse, pA->pRight, pB->pRight, iTab) ) return 2;

  102087.     if( sqlite3ExprListCompare(pA->x.pList, pB->x.pList, iTab) ) return 2;

  102088.     if( pA->op!=TK_STRING

  102089.      && pA->op!=TK_TRUEFALSE

  102090.      && (combinedFlags & EP_Reduced)==0

  102091.     ){

  102092.       if( pA->iColumn!=pB->iColumn ) return 2;

  102093.       if( pA->op2!=pB->op2 ) return 2;

  102094.       if( pA->iTable!=pB->iTable 

  102095.        && (pA->iTable!=iTab || NEVER(pB->iTable>=0)) ) return 2;

  102096.     }

  102097.   }

  102098.   return 0;

  102099. }

  102100. 

  102101. /*

  102102. ** Compare two ExprList objects.  Return 0 if they are identical and 

  102103. ** non-zero if they differ in any way.

  102104. **

  102105. ** If any subelement of pB has Expr.iTable==(-1) then it is allowed

  102106. ** to compare equal to an equivalent element in pA with Expr.iTable==iTab.

  102107. **

  102108. ** This routine might return non-zero for equivalent ExprLists.  The

  102109. ** only consequence will be disabled optimizations.  But this routine

  102110. ** must never return 0 if the two ExprList objects are different, or

  102111. ** a malfunction will result.

  102112. **

  102113. ** Two NULL pointers are considered to be the same.  But a NULL pointer

  102114. ** always differs from a non-NULL pointer.

  102115. */

  102116. SQLITE_PRIVATE int sqlite3ExprListCompare(ExprList *pA, ExprList *pB, int iTab){

  102117.   int i;

  102118.   if( pA==0 && pB==0 ) return 0;

  102119.   if( pA==0 || pB==0 ) return 1;

  102120.   if( pA->nExpr!=pB->nExpr ) return 1;

  102121.   for(i=0; i<pA->nExpr; i++){

  102122.     Expr *pExprA = pA->a[i].pExpr;

  102123.     Expr *pExprB = pB->a[i].pExpr;

  102124.     if( pA->a[i].sortOrder!=pB->a[i].sortOrder ) return 1;

  102125.     if( sqlite3ExprCompare(0, pExprA, pExprB, iTab) ) return 1;

  102126.   }

  102127.   return 0;

  102128. }

  102129. 

  102130. /*

  102131. ** Like sqlite3ExprCompare() except COLLATE operators at the top-level

  102132. ** are ignored.

  102133. */

  102134. SQLITE_PRIVATE int sqlite3ExprCompareSkip(Expr *pA, Expr *pB, int iTab){

  102135.   return sqlite3ExprCompare(0,

  102136.              sqlite3ExprSkipCollate(pA),

  102137.              sqlite3ExprSkipCollate(pB),

  102138.              iTab);

  102139. }

  102140. 

  102141. /*

  102142. ** Return non-zero if Expr p can only be true if pNN is not NULL.

  102143. */

  102144. static int exprImpliesNotNull(

  102145.   Parse *pParse,      /* Parsing context */

  102146.   Expr *p,            /* The expression to be checked */

  102147.   Expr *pNN,          /* The expression that is NOT NULL */

  102148.   int iTab,           /* Table being evaluated */

  102149.   int seenNot         /* True if p is an operand of NOT */

  102150. ){

  102151.   assert( p );

  102152.   assert( pNN );

  102153.   if( sqlite3ExprCompare(pParse, p, pNN, iTab)==0 ) return 1;

  102154.   switch( p->op ){

  102155.     case TK_IN: {

  102156.       if( seenNot && ExprHasProperty(p, EP_xIsSelect) ) return 0;

  102157.       assert( ExprHasProperty(p,EP_xIsSelect)

  102158.            || (p->x.pList!=0 && p->x.pList->nExpr>0) );

  102159.       return exprImpliesNotNull(pParse, p->pLeft, pNN, iTab, seenNot);

  102160.     }

  102161.     case TK_BETWEEN: {

  102162.       ExprList *pList = p->x.pList;

  102163.       assert( pList!=0 );

  102164.       assert( pList->nExpr==2 );

  102165.       if( seenNot ) return 0;

  102166.       if( exprImpliesNotNull(pParse, pList->a[0].pExpr, pNN, iTab, seenNot)

  102167.        || exprImpliesNotNull(pParse, pList->a[1].pExpr, pNN, iTab, seenNot)

  102168.       ){

  102169.         return 1;

  102170.       }

  102171.       return exprImpliesNotNull(pParse, p->pLeft, pNN, iTab, seenNot);

  102172.     }

  102173.     case TK_EQ:

  102174.     case TK_NE:

  102175.     case TK_LT:

  102176.     case TK_LE:

  102177.     case TK_GT:

  102178.     case TK_GE:

  102179.     case TK_PLUS:

  102180.     case TK_MINUS:

  102181.     case TK_STAR:

  102182.     case TK_REM:

  102183.     case TK_BITAND:

  102184.     case TK_BITOR:

  102185.     case TK_SLASH:

  102186.     case TK_LSHIFT:

  102187.     case TK_RSHIFT: 

  102188.     case TK_CONCAT: {

  102189.       if( exprImpliesNotNull(pParse, p->pRight, pNN, iTab, seenNot) ) return 1;

  102190.       /* Fall thru into the next case */

  102191.     }

  102192.     case TK_SPAN:

  102193.     case TK_COLLATE:

  102194.     case TK_BITNOT:

  102195.     case TK_UPLUS:

  102196.     case TK_UMINUS: {

  102197.       return exprImpliesNotNull(pParse, p->pLeft, pNN, iTab, seenNot);

  102198.     }

  102199.     case TK_TRUTH: {

  102200.       if( seenNot ) return 0;

  102201.       if( p->op2!=TK_IS ) return 0;

  102202.       return exprImpliesNotNull(pParse, p->pLeft, pNN, iTab, seenNot);

  102203.     }

  102204.     case TK_NOT: {

  102205.       return exprImpliesNotNull(pParse, p->pLeft, pNN, iTab, 1);

  102206.     }

  102207.   }

  102208.   return 0;

  102209. }

  102210. 

  102211. /*

  102212. ** Return true if we can prove the pE2 will always be true if pE1 is

  102213. ** true.  Return false if we cannot complete the proof or if pE2 might

  102214. ** be false.  Examples:

  102215. **

  102216. **     pE1: x==5       pE2: x==5             Result: true

  102217. **     pE1: x>0        pE2: x==5             Result: false

  102218. **     pE1: x=21       pE2: x=21 OR y=43     Result: true

  102219. **     pE1: x!=123     pE2: x IS NOT NULL    Result: true

  102220. **     pE1: x!=?1      pE2: x IS NOT NULL    Result: true

  102221. **     pE1: x IS NULL  pE2: x IS NOT NULL    Result: false

  102222. **     pE1: x IS ?2    pE2: x IS NOT NULL    Reuslt: false

  102223. **

  102224. ** When comparing TK_COLUMN nodes between pE1 and pE2, if pE2 has

  102225. ** Expr.iTable<0 then assume a table number given by iTab.

  102226. **

  102227. ** If pParse is not NULL, then the values of bound variables in pE1 are 

  102228. ** compared against literal values in pE2 and pParse->pVdbe->expmask is

  102229. ** modified to record which bound variables are referenced.  If pParse 

  102230. ** is NULL, then false will be returned if pE1 contains any bound variables.

  102231. **

  102232. ** When in doubt, return false.  Returning true might give a performance

  102233. ** improvement.  Returning false might cause a performance reduction, but

  102234. ** it will always give the correct answer and is hence always safe.

  102235. */

  102236. SQLITE_PRIVATE int sqlite3ExprImpliesExpr(Parse *pParse, Expr *pE1, Expr *pE2, int iTab){

  102237.   if( sqlite3ExprCompare(pParse, pE1, pE2, iTab)==0 ){

  102238.     return 1;

  102239.   }

  102240.   if( pE2->op==TK_OR

  102241.    && (sqlite3ExprImpliesExpr(pParse, pE1, pE2->pLeft, iTab)

  102242.              || sqlite3ExprImpliesExpr(pParse, pE1, pE2->pRight, iTab) )

  102243.   ){

  102244.     return 1;

  102245.   }

  102246.   if( pE2->op==TK_NOTNULL

  102247.    && exprImpliesNotNull(pParse, pE1, pE2->pLeft, iTab, 0)

  102248.   ){

  102249.     return 1;

  102250.   }

  102251.   return 0;

  102252. }

  102253. 

  102254. /*

  102255. ** This is the Expr node callback for sqlite3ExprImpliesNotNullRow().

  102256. ** If the expression node requires that the table at pWalker->iCur

  102257. ** have one or more non-NULL column, then set pWalker->eCode to 1 and abort.

  102258. **

  102259. ** This routine controls an optimization.  False positives (setting

  102260. ** pWalker->eCode to 1 when it should not be) are deadly, but false-negatives

  102261. ** (never setting pWalker->eCode) is a harmless missed optimization.

  102262. */

  102263. static int impliesNotNullRow(Walker *pWalker, Expr *pExpr){

  102264.   testcase( pExpr->op==TK_AGG_COLUMN );

  102265.   testcase( pExpr->op==TK_AGG_FUNCTION );

  102266.   if( ExprHasProperty(pExpr, EP_FromJoin) ) return WRC_Prune;

  102267.   switch( pExpr->op ){

  102268.     case TK_ISNOT:

  102269.     case TK_NOT:

  102270.     case TK_ISNULL:

  102271.     case TK_NOTNULL:

  102272.     case TK_IS:

  102273.     case TK_OR:

  102274.     case TK_CASE:

  102275.     case TK_IN:

  102276.     case TK_FUNCTION:

  102277.       testcase( pExpr->op==TK_ISNOT );

  102278.       testcase( pExpr->op==TK_NOT );

  102279.       testcase( pExpr->op==TK_ISNULL );

  102280.       testcase( pExpr->op==TK_NOTNULL );

  102281.       testcase( pExpr->op==TK_IS );

  102282.       testcase( pExpr->op==TK_OR );

  102283.       testcase( pExpr->op==TK_CASE );

  102284.       testcase( pExpr->op==TK_IN );

  102285.       testcase( pExpr->op==TK_FUNCTION );

  102286.       return WRC_Prune;

  102287.     case TK_COLUMN:

  102288.       if( pWalker->u.iCur==pExpr->iTable ){

  102289.         pWalker->eCode = 1;

  102290.         return WRC_Abort;

  102291.       }

  102292.       return WRC_Prune;

  102293. 

  102294.     /* Virtual tables are allowed to use constraints like x=NULL.  So

  102295.     ** a term of the form x=y does not prove that y is not null if x

  102296.     ** is the column of a virtual table */

  102297.     case TK_EQ:

  102298.     case TK_NE:

  102299.     case TK_LT:

  102300.     case TK_LE:

  102301.     case TK_GT:

  102302.     case TK_GE:

  102303.       testcase( pExpr->op==TK_EQ );

  102304.       testcase( pExpr->op==TK_NE );

  102305.       testcase( pExpr->op==TK_LT );

  102306.       testcase( pExpr->op==TK_LE );

  102307.       testcase( pExpr->op==TK_GT );

  102308.       testcase( pExpr->op==TK_GE );

  102309.       if( (pExpr->pLeft->op==TK_COLUMN && IsVirtual(pExpr->pLeft->y.pTab))

  102310.        || (pExpr->pRight->op==TK_COLUMN && IsVirtual(pExpr->pRight->y.pTab))

  102311.       ){

  102312.        return WRC_Prune;

  102313.       }

  102314.     default:

  102315.       return WRC_Continue;

  102316.   }

  102317. }

  102318. 

  102319. /*

  102320. ** Return true (non-zero) if expression p can only be true if at least

  102321. ** one column of table iTab is non-null.  In other words, return true

  102322. ** if expression p will always be NULL or false if every column of iTab

  102323. ** is NULL.

  102324. **

  102325. ** False negatives are acceptable.  In other words, it is ok to return

  102326. ** zero even if expression p will never be true of every column of iTab

  102327. ** is NULL.  A false negative is merely a missed optimization opportunity.

  102328. **

  102329. ** False positives are not allowed, however.  A false positive may result

  102330. ** in an incorrect answer.

  102331. **

  102332. ** Terms of p that are marked with EP_FromJoin (and hence that come from

  102333. ** the ON or USING clauses of LEFT JOINS) are excluded from the analysis.

  102334. **

  102335. ** This routine is used to check if a LEFT JOIN can be converted into

  102336. ** an ordinary JOIN.  The p argument is the WHERE clause.  If the WHERE

  102337. ** clause requires that some column of the right table of the LEFT JOIN

  102338. ** be non-NULL, then the LEFT JOIN can be safely converted into an

  102339. ** ordinary join.

  102340. */

  102341. SQLITE_PRIVATE int sqlite3ExprImpliesNonNullRow(Expr *p, int iTab){

  102342.   Walker w;

  102343.   p = sqlite3ExprSkipCollate(p);

  102344.   while( p ){

  102345.     if( p->op==TK_NOTNULL ){

  102346.       p = p->pLeft;

  102347.     }else if( p->op==TK_AND ){

  102348.       if( sqlite3ExprImpliesNonNullRow(p->pLeft, iTab) ) return 1;

  102349.       p = p->pRight;

  102350.     }else{

  102351.       break;

  102352.     }

  102353.   }

  102354.   w.xExprCallback = impliesNotNullRow;

  102355.   w.xSelectCallback = 0;

  102356.   w.xSelectCallback2 = 0;

  102357.   w.eCode = 0;

  102358.   w.u.iCur = iTab;

  102359.   sqlite3WalkExpr(&w, p);

  102360.   return w.eCode;

  102361. }

  102362. 

  102363. /*

  102364. ** An instance of the following structure is used by the tree walker

  102365. ** to determine if an expression can be evaluated by reference to the

  102366. ** index only, without having to do a search for the corresponding

  102367. ** table entry.  The IdxCover.pIdx field is the index.  IdxCover.iCur

  102368. ** is the cursor for the table.

  102369. */

  102370. struct IdxCover {

  102371.   Index *pIdx;     /* The index to be tested for coverage */

  102372.   int iCur;        /* Cursor number for the table corresponding to the index */

  102373. };

  102374. 

  102375. /*

  102376. ** Check to see if there are references to columns in table 

  102377. ** pWalker->u.pIdxCover->iCur can be satisfied using the index

  102378. ** pWalker->u.pIdxCover->pIdx.

  102379. */

  102380. static int exprIdxCover(Walker *pWalker, Expr *pExpr){

  102381.   if( pExpr->op==TK_COLUMN

  102382.    && pExpr->iTable==pWalker->u.pIdxCover->iCur

  102383.    && sqlite3ColumnOfIndex(pWalker->u.pIdxCover->pIdx, pExpr->iColumn)<0

  102384.   ){

  102385.     pWalker->eCode = 1;

  102386.     return WRC_Abort;

  102387.   }

  102388.   return WRC_Continue;

  102389. }

  102390. 

  102391. /*

  102392. ** Determine if an index pIdx on table with cursor iCur contains will

  102393. ** the expression pExpr.  Return true if the index does cover the

  102394. ** expression and false if the pExpr expression references table columns

  102395. ** that are not found in the index pIdx.

  102396. **

  102397. ** An index covering an expression means that the expression can be

  102398. ** evaluated using only the index and without having to lookup the

  102399. ** corresponding table entry.

  102400. */

  102401. SQLITE_PRIVATE int sqlite3ExprCoveredByIndex(

  102402.   Expr *pExpr,        /* The index to be tested */

  102403.   int iCur,           /* The cursor number for the corresponding table */

  102404.   Index *pIdx         /* The index that might be used for coverage */

  102405. ){

  102406.   Walker w;

  102407.   struct IdxCover xcov;

  102408.   memset(&w, 0, sizeof(w));

  102409.   xcov.iCur = iCur;

  102410.   xcov.pIdx = pIdx;

  102411.   w.xExprCallback = exprIdxCover;

  102412.   w.u.pIdxCover = &xcov;

  102413.   sqlite3WalkExpr(&w, pExpr);

  102414.   return !w.eCode;

  102415. }

  102416. 

  102417. 

  102418. /*

  102419. ** An instance of the following structure is used by the tree walker

  102420. ** to count references to table columns in the arguments of an 

  102421. ** aggregate function, in order to implement the

  102422. ** sqlite3FunctionThisSrc() routine.

  102423. */

  102424. struct SrcCount {

  102425.   SrcList *pSrc;   /* One particular FROM clause in a nested query */

  102426.   int nThis;       /* Number of references to columns in pSrcList */

  102427.   int nOther;      /* Number of references to columns in other FROM clauses */

  102428. };

  102429. 

  102430. /*

  102431. ** Count the number of references to columns.

  102432. */

  102433. static int exprSrcCount(Walker *pWalker, Expr *pExpr){

  102434.   /* The NEVER() on the second term is because sqlite3FunctionUsesThisSrc()

  102435.   ** is always called before sqlite3ExprAnalyzeAggregates() and so the

  102436.   ** TK_COLUMNs have not yet been converted into TK_AGG_COLUMN.  If

  102437.   ** sqlite3FunctionUsesThisSrc() is used differently in the future, the

  102438.   ** NEVER() will need to be removed. */

  102439.   if( pExpr->op==TK_COLUMN || NEVER(pExpr->op==TK_AGG_COLUMN) ){

  102440.     int i;

  102441.     struct SrcCount *p = pWalker->u.pSrcCount;

  102442.     SrcList *pSrc = p->pSrc;

  102443.     int nSrc = pSrc ? pSrc->nSrc : 0;

  102444.     for(i=0; i<nSrc; i++){

  102445.       if( pExpr->iTable==pSrc->a[i].iCursor ) break;

  102446.     }

  102447.     if( i<nSrc ){

  102448.       p->nThis++;

  102449.     }else{

  102450.       p->nOther++;

  102451.     }

  102452.   }

  102453.   return WRC_Continue;

  102454. }

  102455. 

  102456. /*

  102457. ** Determine if any of the arguments to the pExpr Function reference

  102458. ** pSrcList.  Return true if they do.  Also return true if the function

  102459. ** has no arguments or has only constant arguments.  Return false if pExpr

  102460. ** references columns but not columns of tables found in pSrcList.

  102461. */

  102462. SQLITE_PRIVATE int sqlite3FunctionUsesThisSrc(Expr *pExpr, SrcList *pSrcList){

  102463.   Walker w;

  102464.   struct SrcCount cnt;

  102465.   assert( pExpr->op==TK_AGG_FUNCTION );

  102466.   w.xExprCallback = exprSrcCount;

  102467.   w.xSelectCallback = 0;

  102468.   w.u.pSrcCount = &cnt;

  102469.   cnt.pSrc = pSrcList;

  102470.   cnt.nThis = 0;

  102471.   cnt.nOther = 0;

  102472.   sqlite3WalkExprList(&w, pExpr->x.pList);

  102473.   return cnt.nThis>0 || cnt.nOther==0;

  102474. }

  102475. 

  102476. /*

  102477. ** Add a new element to the pAggInfo->aCol[] array.  Return the index of

  102478. ** the new element.  Return a negative number if malloc fails.

  102479. */

  102480. static int addAggInfoColumn(sqlite3 *db, AggInfo *pInfo){

  102481.   int i;

  102482.   pInfo->aCol = sqlite3ArrayAllocate(

  102483.        db,

  102484.        pInfo->aCol,

  102485.        sizeof(pInfo->aCol[0]),

  102486.        &pInfo->nColumn,

  102487.        &i

  102488.   );

  102489.   return i;

  102490. }    

  102491. 

  102492. /*

  102493. ** Add a new element to the pAggInfo->aFunc[] array.  Return the index of

  102494. ** the new element.  Return a negative number if malloc fails.

  102495. */

  102496. static int addAggInfoFunc(sqlite3 *db, AggInfo *pInfo){

  102497.   int i;

  102498.   pInfo->aFunc = sqlite3ArrayAllocate(

  102499.        db, 

  102500.        pInfo->aFunc,

  102501.        sizeof(pInfo->aFunc[0]),

  102502.        &pInfo->nFunc,

  102503.        &i

  102504.   );

  102505.   return i;

  102506. }    

  102507. 

  102508. /*

  102509. ** This is the xExprCallback for a tree walker.  It is used to

  102510. ** implement sqlite3ExprAnalyzeAggregates().  See sqlite3ExprAnalyzeAggregates

  102511. ** for additional information.

  102512. */

  102513. static int analyzeAggregate(Walker *pWalker, Expr *pExpr){

  102514.   int i;

  102515.   NameContext *pNC = pWalker->u.pNC;

  102516.   Parse *pParse = pNC->pParse;

  102517.   SrcList *pSrcList = pNC->pSrcList;

  102518.   AggInfo *pAggInfo = pNC->uNC.pAggInfo;

  102519. 

  102520.   assert( pNC->ncFlags & NC_UAggInfo );

  102521.   switch( pExpr->op ){

  102522.     case TK_AGG_COLUMN:

  102523.     case TK_COLUMN: {

  102524.       testcase( pExpr->op==TK_AGG_COLUMN );

  102525.       testcase( pExpr->op==TK_COLUMN );

  102526.       /* Check to see if the column is in one of the tables in the FROM

  102527.       ** clause of the aggregate query */

  102528.       if( ALWAYS(pSrcList!=0) ){

  102529.         struct SrcList_item *pItem = pSrcList->a;

  102530.         for(i=0; i<pSrcList->nSrc; i++, pItem++){

  102531.           struct AggInfo_col *pCol;

  102532.           assert( !ExprHasProperty(pExpr, EP_TokenOnly|EP_Reduced) );

  102533.           if( pExpr->iTable==pItem->iCursor ){

  102534.             /* If we reach this point, it means that pExpr refers to a table

  102535.             ** that is in the FROM clause of the aggregate query.  

  102536.             **

  102537.             ** Make an entry for the column in pAggInfo->aCol[] if there

  102538.             ** is not an entry there already.

  102539.             */

  102540.             int k;

  102541.             pCol = pAggInfo->aCol;

  102542.             for(k=0; k<pAggInfo->nColumn; k++, pCol++){

  102543.               if( pCol->iTable==pExpr->iTable &&

  102544.                   pCol->iColumn==pExpr->iColumn ){

  102545.                 break;

  102546.               }

  102547.             }

  102548.             if( (k>=pAggInfo->nColumn)

  102549.              && (k = addAggInfoColumn(pParse->db, pAggInfo))>=0 

  102550.             ){

  102551.               pCol = &pAggInfo->aCol[k];

  102552.               pCol->pTab = pExpr->y.pTab;

  102553.               pCol->iTable = pExpr->iTable;

  102554.               pCol->iColumn = pExpr->iColumn;

  102555.               pCol->iMem = ++pParse->nMem;

  102556.               pCol->iSorterColumn = -1;

  102557.               pCol->pExpr = pExpr;

  102558.               if( pAggInfo->pGroupBy ){

  102559.                 int j, n;

  102560.                 ExprList *pGB = pAggInfo->pGroupBy;

  102561.                 struct ExprList_item *pTerm = pGB->a;

  102562.                 n = pGB->nExpr;

  102563.                 for(j=0; j<n; j++, pTerm++){

  102564.                   Expr *pE = pTerm->pExpr;

  102565.                   if( pE->op==TK_COLUMN && pE->iTable==pExpr->iTable &&

  102566.                       pE->iColumn==pExpr->iColumn ){

  102567.                     pCol->iSorterColumn = j;

  102568.                     break;

  102569.                   }

  102570.                 }

  102571.               }

  102572.               if( pCol->iSorterColumn<0 ){

  102573.                 pCol->iSorterColumn = pAggInfo->nSortingColumn++;

  102574.               }

  102575.             }

  102576.             /* There is now an entry for pExpr in pAggInfo->aCol[] (either

  102577.             ** because it was there before or because we just created it).

  102578.             ** Convert the pExpr to be a TK_AGG_COLUMN referring to that

  102579.             ** pAggInfo->aCol[] entry.

  102580.             */

  102581.             ExprSetVVAProperty(pExpr, EP_NoReduce);

  102582.             pExpr->pAggInfo = pAggInfo;

  102583.             pExpr->op = TK_AGG_COLUMN;

  102584.             pExpr->iAgg = (i16)k;

  102585.             break;

  102586.           } /* endif pExpr->iTable==pItem->iCursor */

  102587.         } /* end loop over pSrcList */

  102588.       }

  102589.       return WRC_Prune;

  102590.     }

  102591.     case TK_AGG_FUNCTION: {

  102592.       if( (pNC->ncFlags & NC_InAggFunc)==0

  102593.        && pWalker->walkerDepth==pExpr->op2

  102594.       ){

  102595.         /* Check to see if pExpr is a duplicate of another aggregate 

  102596.         ** function that is already in the pAggInfo structure

  102597.         */

  102598.         struct AggInfo_func *pItem = pAggInfo->aFunc;

  102599.         for(i=0; i<pAggInfo->nFunc; i++, pItem++){

  102600.           if( sqlite3ExprCompare(0, pItem->pExpr, pExpr, -1)==0 ){

  102601.             break;

  102602.           }

  102603.         }

  102604.         if( i>=pAggInfo->nFunc ){

  102605.           /* pExpr is original.  Make a new entry in pAggInfo->aFunc[]

  102606.           */

  102607.           u8 enc = ENC(pParse->db);

  102608.           i = addAggInfoFunc(pParse->db, pAggInfo);

  102609.           if( i>=0 ){

  102610.             assert( !ExprHasProperty(pExpr, EP_xIsSelect) );

  102611.             pItem = &pAggInfo->aFunc[i];

  102612.             pItem->pExpr = pExpr;

  102613.             pItem->iMem = ++pParse->nMem;

  102614.             assert( !ExprHasProperty(pExpr, EP_IntValue) );

  102615.             pItem->pFunc = sqlite3FindFunction(pParse->db,

  102616.                    pExpr->u.zToken, 

  102617.                    pExpr->x.pList ? pExpr->x.pList->nExpr : 0, enc, 0);

  102618.             if( pExpr->flags & EP_Distinct ){

  102619.               pItem->iDistinct = pParse->nTab++;

  102620.             }else{

  102621.               pItem->iDistinct = -1;

  102622.             }

  102623.           }

  102624.         }

  102625.         /* Make pExpr point to the appropriate pAggInfo->aFunc[] entry

  102626.         */

  102627.         assert( !ExprHasProperty(pExpr, EP_TokenOnly|EP_Reduced) );

  102628.         ExprSetVVAProperty(pExpr, EP_NoReduce);

  102629.         pExpr->iAgg = (i16)i;

  102630.         pExpr->pAggInfo = pAggInfo;

  102631.         return WRC_Prune;

  102632.       }else{

  102633.         return WRC_Continue;

  102634.       }

  102635.     }

  102636.   }

  102637.   return WRC_Continue;

  102638. }

  102639. static int analyzeAggregatesInSelect(Walker *pWalker, Select *pSelect){

  102640.   UNUSED_PARAMETER(pSelect);

  102641.   pWalker->walkerDepth++;

  102642.   return WRC_Continue;

  102643. }

  102644. static void analyzeAggregatesInSelectEnd(Walker *pWalker, Select *pSelect){

  102645.   UNUSED_PARAMETER(pSelect);

  102646.   pWalker->walkerDepth--;

  102647. }

  102648. 

  102649. /*

  102650. ** Analyze the pExpr expression looking for aggregate functions and

  102651. ** for variables that need to be added to AggInfo object that pNC->pAggInfo

  102652. ** points to.  Additional entries are made on the AggInfo object as

  102653. ** necessary.

  102654. **

  102655. ** This routine should only be called after the expression has been

  102656. ** analyzed by sqlite3ResolveExprNames().

  102657. */

  102658. SQLITE_PRIVATE void sqlite3ExprAnalyzeAggregates(NameContext *pNC, Expr *pExpr){

  102659.   Walker w;

  102660.   w.xExprCallback = analyzeAggregate;

  102661.   w.xSelectCallback = analyzeAggregatesInSelect;

  102662.   w.xSelectCallback2 = analyzeAggregatesInSelectEnd;

  102663.   w.walkerDepth = 0;

  102664.   w.u.pNC = pNC;

  102665.   w.pParse = 0;

  102666.   assert( pNC->pSrcList!=0 );

  102667.   sqlite3WalkExpr(&w, pExpr);

  102668. }

  102669. 

  102670. /*

  102671. ** Call sqlite3ExprAnalyzeAggregates() for every expression in an

  102672. ** expression list.  Return the number of errors.

  102673. **

  102674. ** If an error is found, the analysis is cut short.

  102675. */

  102676. SQLITE_PRIVATE void sqlite3ExprAnalyzeAggList(NameContext *pNC, ExprList *pList){

  102677.   struct ExprList_item *pItem;

  102678.   int i;

  102679.   if( pList ){

  102680.     for(pItem=pList->a, i=0; i<pList->nExpr; i++, pItem++){

  102681.       sqlite3ExprAnalyzeAggregates(pNC, pItem->pExpr);

  102682.     }

  102683.   }

  102684. }

  102685. 

  102686. /*

  102687. ** Allocate a single new register for use to hold some intermediate result.

  102688. */

  102689. SQLITE_PRIVATE int sqlite3GetTempReg(Parse *pParse){

  102690.   if( pParse->nTempReg==0 ){

  102691.     return ++pParse->nMem;

  102692.   }

  102693.   return pParse->aTempReg[--pParse->nTempReg];

  102694. }

  102695. 

  102696. /*

  102697. ** Deallocate a register, making available for reuse for some other

  102698. ** purpose.

  102699. */

  102700. SQLITE_PRIVATE void sqlite3ReleaseTempReg(Parse *pParse, int iReg){

  102701.   if( iReg && pParse->nTempReg<ArraySize(pParse->aTempReg) ){

  102702.     pParse->aTempReg[pParse->nTempReg++] = iReg;

  102703.   }

  102704. }

  102705. 

  102706. /*

  102707. ** Allocate or deallocate a block of nReg consecutive registers.

  102708. */

  102709. SQLITE_PRIVATE int sqlite3GetTempRange(Parse *pParse, int nReg){

  102710.   int i, n;

  102711.   if( nReg==1 ) return sqlite3GetTempReg(pParse);

  102712.   i = pParse->iRangeReg;

  102713.   n = pParse->nRangeReg;

  102714.   if( nReg<=n ){

  102715.     pParse->iRangeReg += nReg;

  102716.     pParse->nRangeReg -= nReg;

  102717.   }else{

  102718.     i = pParse->nMem+1;

  102719.     pParse->nMem += nReg;

  102720.   }

  102721.   return i;

  102722. }

  102723. SQLITE_PRIVATE void sqlite3ReleaseTempRange(Parse *pParse, int iReg, int nReg){

  102724.   if( nReg==1 ){

  102725.     sqlite3ReleaseTempReg(pParse, iReg);

  102726.     return;

  102727.   }

  102728.   if( nReg>pParse->nRangeReg ){

  102729.     pParse->nRangeReg = nReg;

  102730.     pParse->iRangeReg = iReg;

  102731.   }

  102732. }

  102733. 

  102734. /*

  102735. ** Mark all temporary registers as being unavailable for reuse.

  102736. */

  102737. SQLITE_PRIVATE void sqlite3ClearTempRegCache(Parse *pParse){

  102738.   pParse->nTempReg = 0;

  102739.   pParse->nRangeReg = 0;

  102740. }

  102741. 

  102742. /*

  102743. ** Validate that no temporary register falls within the range of

  102744. ** iFirst..iLast, inclusive.  This routine is only call from within assert()

  102745. ** statements.

  102746. */

  102747. #ifdef SQLITE_DEBUG

  102748. SQLITE_PRIVATE int sqlite3NoTempsInRange(Parse *pParse, int iFirst, int iLast){

  102749.   int i;

  102750.   if( pParse->nRangeReg>0

  102751.    && pParse->iRangeReg+pParse->nRangeReg > iFirst

  102752.    && pParse->iRangeReg <= iLast

  102753.   ){

  102754.      return 0;

  102755.   }

  102756.   for(i=0; i<pParse->nTempReg; i++){

  102757.     if( pParse->aTempReg[i]>=iFirst && pParse->aTempReg[i]<=iLast ){

  102758.       return 0;

  102759.     }

  102760.   }

  102761.   return 1;

  102762. }

  102763. #endif /* SQLITE_DEBUG */

  102764. 

  102765. /************** End of expr.c ************************************************/

  102766. /************** Begin file alter.c *******************************************/

  102767. /*

  102768. ** 2005 February 15

  102769. **

  102770. ** The author disclaims copyright to this source code.  In place of

  102771. ** a legal notice, here is a blessing:

  102772. **

  102773. **    May you do good and not evil.

  102774. **    May you find forgiveness for yourself and forgive others.

  102775. **    May you share freely, never taking more than you give.

  102776. **

  102777. *************************************************************************

  102778. ** This file contains C code routines that used to generate VDBE code

  102779. ** that implements the ALTER TABLE command.

  102780. */

  102781. /* #include "sqliteInt.h" */

  102782. 

  102783. /*

  102784. ** The code in this file only exists if we are not omitting the

  102785. ** ALTER TABLE logic from the build.

  102786. */

  102787. #ifndef SQLITE_OMIT_ALTERTABLE

  102788. 

  102789. /*

  102790. ** Parameter zName is the name of a table that is about to be altered

  102791. ** (either with ALTER TABLE ... RENAME TO or ALTER TABLE ... ADD COLUMN).

  102792. ** If the table is a system table, this function leaves an error message

  102793. ** in pParse->zErr (system tables may not be altered) and returns non-zero.

  102794. **

  102795. ** Or, if zName is not a system table, zero is returned.

  102796. */

  102797. static int isAlterableTable(Parse *pParse, Table *pTab){

  102798.   if( 0==sqlite3StrNICmp(pTab->zName, "sqlite_", 7) 

  102799. #ifndef SQLITE_OMIT_VIRTUALTABLE

  102800.    || ( (pTab->tabFlags & TF_Shadow) 

  102801.      && (pParse->db->flags & SQLITE_Defensive)

  102802.      && pParse->db->nVdbeExec==0

  102803.    )

  102804. #endif

  102805.   ){

  102806.     sqlite3ErrorMsg(pParse, "table %s may not be altered", pTab->zName);

  102807.     return 1;

  102808.   }

  102809.   return 0;

  102810. }

  102811. 

  102812. /*

  102813. ** Generate code to verify that the schemas of database zDb and, if

  102814. ** bTemp is not true, database "temp", can still be parsed. This is

  102815. ** called at the end of the generation of an ALTER TABLE ... RENAME ...

  102816. ** statement to ensure that the operation has not rendered any schema

  102817. ** objects unusable.

  102818. */

  102819. static void renameTestSchema(Parse *pParse, const char *zDb, int bTemp){

  102820.   sqlite3NestedParse(pParse, 

  102821.       "SELECT 1 "

  102822.       "FROM \"%w\".%s "

  102823.       "WHERE name NOT LIKE 'sqliteX_%%' ESCAPE 'X'"

  102824.       " AND sql NOT LIKE 'create virtual%%'"

  102825.       " AND sqlite_rename_test(%Q, sql, type, name, %d)=NULL ",

  102826.       zDb, MASTER_NAME, 

  102827.       zDb, bTemp

  102828.   );

  102829. 

  102830.   if( bTemp==0 ){

  102831.     sqlite3NestedParse(pParse, 

  102832.         "SELECT 1 "

  102833.         "FROM temp.%s "

  102834.         "WHERE name NOT LIKE 'sqliteX_%%' ESCAPE 'X'"

  102835.         " AND sql NOT LIKE 'create virtual%%'"

  102836.         " AND sqlite_rename_test(%Q, sql, type, name, 1)=NULL ",

  102837.         MASTER_NAME, zDb 

  102838.     );

  102839.   }

  102840. }

  102841. 

  102842. /*

  102843. ** Generate code to reload the schema for database iDb. And, if iDb!=1, for

  102844. ** the temp database as well.

  102845. */

  102846. static void renameReloadSchema(Parse *pParse, int iDb){

  102847.   Vdbe *v = pParse->pVdbe;

  102848.   if( v ){

  102849.     sqlite3ChangeCookie(pParse, iDb);

  102850.     sqlite3VdbeAddParseSchemaOp(pParse->pVdbe, iDb, 0);

  102851.     if( iDb!=1 ) sqlite3VdbeAddParseSchemaOp(pParse->pVdbe, 1, 0);

  102852.   }

  102853. }

  102854. 

  102855. /*

  102856. ** Generate code to implement the "ALTER TABLE xxx RENAME TO yyy" 

  102857. ** command. 

  102858. */

  102859. SQLITE_PRIVATE void sqlite3AlterRenameTable(

  102860.   Parse *pParse,            /* Parser context. */

  102861.   SrcList *pSrc,            /* The table to rename. */

  102862.   Token *pName              /* The new table name. */

  102863. ){

  102864.   int iDb;                  /* Database that contains the table */

  102865.   char *zDb;                /* Name of database iDb */

  102866.   Table *pTab;              /* Table being renamed */

  102867.   char *zName = 0;          /* NULL-terminated version of pName */ 

  102868.   sqlite3 *db = pParse->db; /* Database connection */

  102869.   int nTabName;             /* Number of UTF-8 characters in zTabName */

  102870.   const char *zTabName;     /* Original name of the table */

  102871.   Vdbe *v;

  102872.   VTable *pVTab = 0;        /* Non-zero if this is a v-tab with an xRename() */

  102873.   u32 savedDbFlags;         /* Saved value of db->mDbFlags */

  102874. 

  102875.   savedDbFlags = db->mDbFlags;  

  102876.   if( NEVER(db->mallocFailed) ) goto exit_rename_table;

  102877.   assert( pSrc->nSrc==1 );

  102878.   assert( sqlite3BtreeHoldsAllMutexes(pParse->db) );

  102879. 

  102880.   pTab = sqlite3LocateTableItem(pParse, 0, &pSrc->a[0]);

  102881.   if( !pTab ) goto exit_rename_table;

  102882.   iDb = sqlite3SchemaToIndex(pParse->db, pTab->pSchema);

  102883.   zDb = db->aDb[iDb].zDbSName;

  102884.   db->mDbFlags |= DBFLAG_PreferBuiltin;

  102885. 

  102886.   /* Get a NULL terminated version of the new table name. */

  102887.   zName = sqlite3NameFromToken(db, pName);

  102888.   if( !zName ) goto exit_rename_table;

  102889. 

  102890.   /* Check that a table or index named 'zName' does not already exist

  102891.   ** in database iDb. If so, this is an error.

  102892.   */

  102893.   if( sqlite3FindTable(db, zName, zDb) || sqlite3FindIndex(db, zName, zDb) ){

  102894.     sqlite3ErrorMsg(pParse, 

  102895.         "there is already another table or index with this name: %s", zName);

  102896.     goto exit_rename_table;

  102897.   }

  102898. 

  102899.   /* Make sure it is not a system table being altered, or a reserved name

  102900.   ** that the table is being renamed to.

  102901.   */

  102902.   if( SQLITE_OK!=isAlterableTable(pParse, pTab) ){

  102903.     goto exit_rename_table;

  102904.   }

  102905.   if( SQLITE_OK!=sqlite3CheckObjectName(pParse, zName) ){ goto

  102906.     exit_rename_table;

  102907.   }

  102908. 

  102909. #ifndef SQLITE_OMIT_VIEW

  102910.   if( pTab->pSelect ){

  102911.     sqlite3ErrorMsg(pParse, "view %s may not be altered", pTab->zName);

  102912.     goto exit_rename_table;

  102913.   }

  102914. #endif

  102915. 

  102916. #ifndef SQLITE_OMIT_AUTHORIZATION

  102917.   /* Invoke the authorization callback. */

  102918.   if( sqlite3AuthCheck(pParse, SQLITE_ALTER_TABLE, zDb, pTab->zName, 0) ){

  102919.     goto exit_rename_table;

  102920.   }

  102921. #endif

  102922. 

  102923. #ifndef SQLITE_OMIT_VIRTUALTABLE

  102924.   if( sqlite3ViewGetColumnNames(pParse, pTab) ){

  102925.     goto exit_rename_table;

  102926.   }

  102927.   if( IsVirtual(pTab) ){

  102928.     pVTab = sqlite3GetVTable(db, pTab);

  102929.     if( pVTab->pVtab->pModule->xRename==0 ){

  102930.       pVTab = 0;

  102931.     }

  102932.   }

  102933. #endif

  102934. 

  102935.   /* Begin a transaction for database iDb. Then modify the schema cookie

  102936.   ** (since the ALTER TABLE modifies the schema). Call sqlite3MayAbort(),

  102937.   ** as the scalar functions (e.g. sqlite_rename_table()) invoked by the 

  102938.   ** nested SQL may raise an exception.  */

  102939.   v = sqlite3GetVdbe(pParse);

  102940.   if( v==0 ){

  102941.     goto exit_rename_table;

  102942.   }

  102943.   sqlite3MayAbort(pParse);

  102944. 

  102945.   /* figure out how many UTF-8 characters are in zName */

  102946.   zTabName = pTab->zName;

  102947.   nTabName = sqlite3Utf8CharLen(zTabName, -1);

  102948. 

  102949.   /* Rewrite all CREATE TABLE, INDEX, TRIGGER or VIEW statements in

  102950.   ** the schema to use the new table name.  */

  102951.   sqlite3NestedParse(pParse, 

  102952.       "UPDATE \"%w\".%s SET "

  102953.       "sql = sqlite_rename_table(%Q, type, name, sql, %Q, %Q, %d) "

  102954.       "WHERE (type!='index' OR tbl_name=%Q COLLATE nocase)"

  102955.       "AND   name NOT LIKE 'sqliteX_%%' ESCAPE 'X'"

  102956.       , zDb, MASTER_NAME, zDb, zTabName, zName, (iDb==1), zTabName

  102957.   );

  102958. 

  102959.   /* Update the tbl_name and name columns of the sqlite_master table

  102960.   ** as required.  */

  102961.   sqlite3NestedParse(pParse,

  102962.       "UPDATE %Q.%s SET "

  102963.           "tbl_name = %Q, "

  102964.           "name = CASE "

  102965.             "WHEN type='table' THEN %Q "

  102966.             "WHEN name LIKE 'sqliteX_autoindex%%' ESCAPE 'X' "

  102967.             "     AND type='index' THEN "

  102968.              "'sqlite_autoindex_' || %Q || substr(name,%d+18) "

  102969.             "ELSE name END "

  102970.       "WHERE tbl_name=%Q COLLATE nocase AND "

  102971.           "(type='table' OR type='index' OR type='trigger');", 

  102972.       zDb, MASTER_NAME, 

  102973.       zName, zName, zName, 

  102974.       nTabName, zTabName

  102975.   );

  102976. 

  102977. #ifndef SQLITE_OMIT_AUTOINCREMENT

  102978.   /* If the sqlite_sequence table exists in this database, then update 

  102979.   ** it with the new table name.

  102980.   */

  102981.   if( sqlite3FindTable(db, "sqlite_sequence", zDb) ){

  102982.     sqlite3NestedParse(pParse,

  102983.         "UPDATE \"%w\".sqlite_sequence set name = %Q WHERE name = %Q",

  102984.         zDb, zName, pTab->zName);

  102985.   }

  102986. #endif

  102987. 

  102988.   /* If the table being renamed is not itself part of the temp database,

  102989.   ** edit view and trigger definitions within the temp database 

  102990.   ** as required.  */

  102991.   if( iDb!=1 ){

  102992.     sqlite3NestedParse(pParse, 

  102993.         "UPDATE sqlite_temp_master SET "

  102994.             "sql = sqlite_rename_table(%Q, type, name, sql, %Q, %Q, 1), "

  102995.             "tbl_name = "

  102996.               "CASE WHEN tbl_name=%Q COLLATE nocase AND "

  102997.               "          sqlite_rename_test(%Q, sql, type, name, 1) "

  102998.               "THEN %Q ELSE tbl_name END "

  102999.             "WHERE type IN ('view', 'trigger')"

  103000.         , zDb, zTabName, zName, zTabName, zDb, zName);

  103001.   }

  103002. 

  103003.   /* If this is a virtual table, invoke the xRename() function if

  103004.   ** one is defined. The xRename() callback will modify the names

  103005.   ** of any resources used by the v-table implementation (including other

  103006.   ** SQLite tables) that are identified by the name of the virtual table.

  103007.   */

  103008. #ifndef SQLITE_OMIT_VIRTUALTABLE

  103009.   if( pVTab ){

  103010.     int i = ++pParse->nMem;

  103011.     sqlite3VdbeLoadString(v, i, zName);

  103012.     sqlite3VdbeAddOp4(v, OP_VRename, i, 0, 0,(const char*)pVTab, P4_VTAB);

  103013.   }

  103014. #endif

  103015. 

  103016.   renameReloadSchema(pParse, iDb);

  103017.   renameTestSchema(pParse, zDb, iDb==1);

  103018. 

  103019. exit_rename_table:

  103020.   sqlite3SrcListDelete(db, pSrc);

  103021.   sqlite3DbFree(db, zName);

  103022.   db->mDbFlags = savedDbFlags;

  103023. }

  103024. 

  103025. /*

  103026. ** This function is called after an "ALTER TABLE ... ADD" statement

  103027. ** has been parsed. Argument pColDef contains the text of the new

  103028. ** column definition.

  103029. **

  103030. ** The Table structure pParse->pNewTable was extended to include

  103031. ** the new column during parsing.

  103032. */

  103033. SQLITE_PRIVATE void sqlite3AlterFinishAddColumn(Parse *pParse, Token *pColDef){

  103034.   Table *pNew;              /* Copy of pParse->pNewTable */

  103035.   Table *pTab;              /* Table being altered */

  103036.   int iDb;                  /* Database number */

  103037.   const char *zDb;          /* Database name */

  103038.   const char *zTab;         /* Table name */

  103039.   char *zCol;               /* Null-terminated column definition */

  103040.   Column *pCol;             /* The new column */

  103041.   Expr *pDflt;              /* Default value for the new column */

  103042.   sqlite3 *db;              /* The database connection; */

  103043.   Vdbe *v;                  /* The prepared statement under construction */

  103044.   int r1;                   /* Temporary registers */

  103045. 

  103046.   db = pParse->db;

  103047.   if( pParse->nErr || db->mallocFailed ) return;

  103048.   pNew = pParse->pNewTable;

  103049.   assert( pNew );

  103050. 

  103051.   assert( sqlite3BtreeHoldsAllMutexes(db) );

  103052.   iDb = sqlite3SchemaToIndex(db, pNew->pSchema);

  103053.   zDb = db->aDb[iDb].zDbSName;

  103054.   zTab = &pNew->zName[16];  /* Skip the "sqlite_altertab_" prefix on the name */

  103055.   pCol = &pNew->aCol[pNew->nCol-1];

  103056.   pDflt = pCol->pDflt;

  103057.   pTab = sqlite3FindTable(db, zTab, zDb);

  103058.   assert( pTab );

  103059. 

  103060. #ifndef SQLITE_OMIT_AUTHORIZATION

  103061.   /* Invoke the authorization callback. */

  103062.   if( sqlite3AuthCheck(pParse, SQLITE_ALTER_TABLE, zDb, pTab->zName, 0) ){

  103063.     return;

  103064.   }

  103065. #endif

  103066. 

  103067.   /* If the default value for the new column was specified with a 

  103068.   ** literal NULL, then set pDflt to 0. This simplifies checking

  103069.   ** for an SQL NULL default below.

  103070.   */

  103071.   assert( pDflt==0 || pDflt->op==TK_SPAN );

  103072.   if( pDflt && pDflt->pLeft->op==TK_NULL ){

  103073.     pDflt = 0;

  103074.   }

  103075. 

  103076.   /* Check that the new column is not specified as PRIMARY KEY or UNIQUE.

  103077.   ** If there is a NOT NULL constraint, then the default value for the

  103078.   ** column must not be NULL.

  103079.   */

  103080.   if( pCol->colFlags & COLFLAG_PRIMKEY ){

  103081.     sqlite3ErrorMsg(pParse, "Cannot add a PRIMARY KEY column");

  103082.     return;

  103083.   }

  103084.   if( pNew->pIndex ){

  103085.     sqlite3ErrorMsg(pParse, "Cannot add a UNIQUE column");

  103086.     return;

  103087.   }

  103088.   if( (db->flags&SQLITE_ForeignKeys) && pNew->pFKey && pDflt ){

  103089.     sqlite3ErrorMsg(pParse, 

  103090.         "Cannot add a REFERENCES column with non-NULL default value");

  103091.     return;

  103092.   }

  103093.   if( pCol->notNull && !pDflt ){

  103094.     sqlite3ErrorMsg(pParse, 

  103095.         "Cannot add a NOT NULL column with default value NULL");

  103096.     return;

  103097.   }

  103098. 

  103099.   /* Ensure the default expression is something that sqlite3ValueFromExpr()

  103100.   ** can handle (i.e. not CURRENT_TIME etc.)

  103101.   */

  103102.   if( pDflt ){

  103103.     sqlite3_value *pVal = 0;

  103104.     int rc;

  103105.     rc = sqlite3ValueFromExpr(db, pDflt, SQLITE_UTF8, SQLITE_AFF_BLOB, &pVal);

  103106.     assert( rc==SQLITE_OK || rc==SQLITE_NOMEM );

  103107.     if( rc!=SQLITE_OK ){

  103108.       assert( db->mallocFailed == 1 );

  103109.       return;

  103110.     }

  103111.     if( !pVal ){

  103112.       sqlite3ErrorMsg(pParse, "Cannot add a column with non-constant default");

  103113.       return;

  103114.     }

  103115.     sqlite3ValueFree(pVal);

  103116.   }

  103117. 

  103118.   /* Modify the CREATE TABLE statement. */

  103119.   zCol = sqlite3DbStrNDup(db, (char*)pColDef->z, pColDef->n);

  103120.   if( zCol ){

  103121.     char *zEnd = &zCol[pColDef->n-1];

  103122.     u32 savedDbFlags = db->mDbFlags;

  103123.     while( zEnd>zCol && (*zEnd==';' || sqlite3Isspace(*zEnd)) ){

  103124.       *zEnd-- = '\0';

  103125.     }

  103126.     db->mDbFlags |= DBFLAG_PreferBuiltin;

  103127.     sqlite3NestedParse(pParse, 

  103128.         "UPDATE \"%w\".%s SET "

  103129.           "sql = substr(sql,1,%d) || ', ' || %Q || substr(sql,%d) "

  103130.         "WHERE type = 'table' AND name = %Q", 

  103131.       zDb, MASTER_NAME, pNew->addColOffset, zCol, pNew->addColOffset+1,

  103132.       zTab

  103133.     );

  103134.     sqlite3DbFree(db, zCol);

  103135.     db->mDbFlags = savedDbFlags;

  103136.   }

  103137. 

  103138.   /* Make sure the schema version is at least 3.  But do not upgrade

  103139.   ** from less than 3 to 4, as that will corrupt any preexisting DESC

  103140.   ** index.

  103141.   */

  103142.   v = sqlite3GetVdbe(pParse);

  103143.   if( v ){

  103144.     r1 = sqlite3GetTempReg(pParse);

  103145.     sqlite3VdbeAddOp3(v, OP_ReadCookie, iDb, r1, BTREE_FILE_FORMAT);

  103146.     sqlite3VdbeUsesBtree(v, iDb);

  103147.     sqlite3VdbeAddOp2(v, OP_AddImm, r1, -2);

  103148.     sqlite3VdbeAddOp2(v, OP_IfPos, r1, sqlite3VdbeCurrentAddr(v)+2);

  103149.     VdbeCoverage(v);

  103150.     sqlite3VdbeAddOp3(v, OP_SetCookie, iDb, BTREE_FILE_FORMAT, 3);

  103151.     sqlite3ReleaseTempReg(pParse, r1);

  103152.   }

  103153. 

  103154.   /* Reload the table definition */

  103155.   renameReloadSchema(pParse, iDb);

  103156. }

  103157. 

  103158. /*

  103159. ** This function is called by the parser after the table-name in

  103160. ** an "ALTER TABLE <table-name> ADD" statement is parsed. Argument 

  103161. ** pSrc is the full-name of the table being altered.

  103162. **

  103163. ** This routine makes a (partial) copy of the Table structure

  103164. ** for the table being altered and sets Parse.pNewTable to point

  103165. ** to it. Routines called by the parser as the column definition

  103166. ** is parsed (i.e. sqlite3AddColumn()) add the new Column data to 

  103167. ** the copy. The copy of the Table structure is deleted by tokenize.c 

  103168. ** after parsing is finished.

  103169. **

  103170. ** Routine sqlite3AlterFinishAddColumn() will be called to complete

  103171. ** coding the "ALTER TABLE ... ADD" statement.

  103172. */

  103173. SQLITE_PRIVATE void sqlite3AlterBeginAddColumn(Parse *pParse, SrcList *pSrc){

  103174.   Table *pNew;

  103175.   Table *pTab;

  103176.   int iDb;

  103177.   int i;

  103178.   int nAlloc;

  103179.   sqlite3 *db = pParse->db;

  103180. 

  103181.   /* Look up the table being altered. */

  103182.   assert( pParse->pNewTable==0 );

  103183.   assert( sqlite3BtreeHoldsAllMutexes(db) );

  103184.   if( db->mallocFailed ) goto exit_begin_add_column;

  103185.   pTab = sqlite3LocateTableItem(pParse, 0, &pSrc->a[0]);

  103186.   if( !pTab ) goto exit_begin_add_column;

  103187. 

  103188. #ifndef SQLITE_OMIT_VIRTUALTABLE

  103189.   if( IsVirtual(pTab) ){

  103190.     sqlite3ErrorMsg(pParse, "virtual tables may not be altered");

  103191.     goto exit_begin_add_column;

  103192.   }

  103193. #endif

  103194. 

  103195.   /* Make sure this is not an attempt to ALTER a view. */

  103196.   if( pTab->pSelect ){

  103197.     sqlite3ErrorMsg(pParse, "Cannot add a column to a view");

  103198.     goto exit_begin_add_column;

  103199.   }

  103200.   if( SQLITE_OK!=isAlterableTable(pParse, pTab) ){

  103201.     goto exit_begin_add_column;

  103202.   }

  103203. 

  103204.   assert( pTab->addColOffset>0 );

  103205.   iDb = sqlite3SchemaToIndex(db, pTab->pSchema);

  103206. 

  103207.   /* Put a copy of the Table struct in Parse.pNewTable for the

  103208.   ** sqlite3AddColumn() function and friends to modify.  But modify

  103209.   ** the name by adding an "sqlite_altertab_" prefix.  By adding this

  103210.   ** prefix, we insure that the name will not collide with an existing

  103211.   ** table because user table are not allowed to have the "sqlite_"

  103212.   ** prefix on their name.

  103213.   */

  103214.   pNew = (Table*)sqlite3DbMallocZero(db, sizeof(Table));

  103215.   if( !pNew ) goto exit_begin_add_column;

  103216.   pParse->pNewTable = pNew;

  103217.   pNew->nTabRef = 1;

  103218.   pNew->nCol = pTab->nCol;

  103219.   assert( pNew->nCol>0 );

  103220.   nAlloc = (((pNew->nCol-1)/8)*8)+8;

  103221.   assert( nAlloc>=pNew->nCol && nAlloc%8==0 && nAlloc-pNew->nCol<8 );

  103222.   pNew->aCol = (Column*)sqlite3DbMallocZero(db, sizeof(Column)*nAlloc);

  103223.   pNew->zName = sqlite3MPrintf(db, "sqlite_altertab_%s", pTab->zName);

  103224.   if( !pNew->aCol || !pNew->zName ){

  103225.     assert( db->mallocFailed );

  103226.     goto exit_begin_add_column;

  103227.   }

  103228.   memcpy(pNew->aCol, pTab->aCol, sizeof(Column)*pNew->nCol);

  103229.   for(i=0; i<pNew->nCol; i++){

  103230.     Column *pCol = &pNew->aCol[i];

  103231.     pCol->zName = sqlite3DbStrDup(db, pCol->zName);

  103232.     pCol->zColl = 0;

  103233.     pCol->pDflt = 0;

  103234.   }

  103235.   pNew->pSchema = db->aDb[iDb].pSchema;

  103236.   pNew->addColOffset = pTab->addColOffset;

  103237.   pNew->nTabRef = 1;

  103238. 

  103239. exit_begin_add_column:

  103240.   sqlite3SrcListDelete(db, pSrc);

  103241.   return;

  103242. }

  103243. 

  103244. /*

  103245. ** Parameter pTab is the subject of an ALTER TABLE ... RENAME COLUMN

  103246. ** command. This function checks if the table is a view or virtual

  103247. ** table (columns of views or virtual tables may not be renamed). If so,

  103248. ** it loads an error message into pParse and returns non-zero.

  103249. **

  103250. ** Or, if pTab is not a view or virtual table, zero is returned.

  103251. */

  103252. #if !defined(SQLITE_OMIT_VIEW) || !defined(SQLITE_OMIT_VIRTUALTABLE)

  103253. static int isRealTable(Parse *pParse, Table *pTab){

  103254.   const char *zType = 0;

  103255. #ifndef SQLITE_OMIT_VIEW

  103256.   if( pTab->pSelect ){

  103257.     zType = "view";

  103258.   }

  103259. #endif

  103260. #ifndef SQLITE_OMIT_VIRTUALTABLE

  103261.   if( IsVirtual(pTab) ){

  103262.     zType = "virtual table";

  103263.   }

  103264. #endif

  103265.   if( zType ){

  103266.     sqlite3ErrorMsg(

  103267.         pParse, "cannot rename columns of %s \"%s\"", zType, pTab->zName

  103268.     );

  103269.     return 1;

  103270.   }

  103271.   return 0;

  103272. }

  103273. #else /* !defined(SQLITE_OMIT_VIEW) || !defined(SQLITE_OMIT_VIRTUALTABLE) */

  103274. # define isRealTable(x,y) (0)

  103275. #endif

  103276. 

  103277. /*

  103278. ** Handles the following parser reduction:

  103279. **

  103280. **  cmd ::= ALTER TABLE pSrc RENAME COLUMN pOld TO pNew

  103281. */

  103282. SQLITE_PRIVATE void sqlite3AlterRenameColumn(

  103283.   Parse *pParse,                  /* Parsing context */

  103284.   SrcList *pSrc,                  /* Table being altered.  pSrc->nSrc==1 */

  103285.   Token *pOld,                    /* Name of column being changed */

  103286.   Token *pNew                     /* New column name */

  103287. ){

  103288.   sqlite3 *db = pParse->db;       /* Database connection */

  103289.   Table *pTab;                    /* Table being updated */

  103290.   int iCol;                       /* Index of column being renamed */

  103291.   char *zOld = 0;                 /* Old column name */

  103292.   char *zNew = 0;                 /* New column name */

  103293.   const char *zDb;                /* Name of schema containing the table */

  103294.   int iSchema;                    /* Index of the schema */

  103295.   int bQuote;                     /* True to quote the new name */

  103296. 

  103297.   /* Locate the table to be altered */

  103298.   pTab = sqlite3LocateTableItem(pParse, 0, &pSrc->a[0]);

  103299.   if( !pTab ) goto exit_rename_column;

  103300. 

  103301.   /* Cannot alter a system table */

  103302.   if( SQLITE_OK!=isAlterableTable(pParse, pTab) ) goto exit_rename_column;

  103303.   if( SQLITE_OK!=isRealTable(pParse, pTab) ) goto exit_rename_column;

  103304. 

  103305.   /* Which schema holds the table to be altered */  

  103306.   iSchema = sqlite3SchemaToIndex(db, pTab->pSchema);

  103307.   assert( iSchema>=0 );

  103308.   zDb = db->aDb[iSchema].zDbSName;

  103309. 

  103310. #ifndef SQLITE_OMIT_AUTHORIZATION

  103311.   /* Invoke the authorization callback. */

  103312.   if( sqlite3AuthCheck(pParse, SQLITE_ALTER_TABLE, zDb, pTab->zName, 0) ){

  103313.     goto exit_rename_column;

  103314.   }

  103315. #endif

  103316. 

  103317.   /* Make sure the old name really is a column name in the table to be

  103318.   ** altered.  Set iCol to be the index of the column being renamed */

  103319.   zOld = sqlite3NameFromToken(db, pOld);

  103320.   if( !zOld ) goto exit_rename_column;

  103321.   for(iCol=0; iCol<pTab->nCol; iCol++){

  103322.     if( 0==sqlite3StrICmp(pTab->aCol[iCol].zName, zOld) ) break;

  103323.   }

  103324.   if( iCol==pTab->nCol ){

  103325.     sqlite3ErrorMsg(pParse, "no such column: \"%s\"", zOld);

  103326.     goto exit_rename_column;

  103327.   }

  103328. 

  103329.   /* Do the rename operation using a recursive UPDATE statement that

  103330.   ** uses the sqlite_rename_column() SQL function to compute the new

  103331.   ** CREATE statement text for the sqlite_master table.

  103332.   */

  103333.   sqlite3MayAbort(pParse);

  103334.   zNew = sqlite3NameFromToken(db, pNew);

  103335.   if( !zNew ) goto exit_rename_column;

  103336.   assert( pNew->n>0 );

  103337.   bQuote = sqlite3Isquote(pNew->z[0]);

  103338.   sqlite3NestedParse(pParse, 

  103339.       "UPDATE \"%w\".%s SET "

  103340.       "sql = sqlite_rename_column(sql, type, name, %Q, %Q, %d, %Q, %d, %d) "

  103341.       "WHERE name NOT LIKE 'sqliteX_%%' ESCAPE 'X' "

  103342.       " AND (type != 'index' OR tbl_name = %Q)"

  103343.       " AND sql NOT LIKE 'create virtual%%'",

  103344.       zDb, MASTER_NAME, 

  103345.       zDb, pTab->zName, iCol, zNew, bQuote, iSchema==1,

  103346.       pTab->zName

  103347.   );

  103348. 

  103349.   sqlite3NestedParse(pParse, 

  103350.       "UPDATE temp.%s SET "

  103351.       "sql = sqlite_rename_column(sql, type, name, %Q, %Q, %d, %Q, %d, 1) "

  103352.       "WHERE type IN ('trigger', 'view')",

  103353.       MASTER_NAME, 

  103354.       zDb, pTab->zName, iCol, zNew, bQuote

  103355.   );

  103356. 

  103357.   /* Drop and reload the database schema. */

  103358.   renameReloadSchema(pParse, iSchema);

  103359.   renameTestSchema(pParse, zDb, iSchema==1);

  103360. 

  103361.  exit_rename_column:

  103362.   sqlite3SrcListDelete(db, pSrc);

  103363.   sqlite3DbFree(db, zOld);

  103364.   sqlite3DbFree(db, zNew);

  103365.   return;

  103366. }

  103367. 

  103368. /*

  103369. ** Each RenameToken object maps an element of the parse tree into

  103370. ** the token that generated that element.  The parse tree element

  103371. ** might be one of:

  103372. **

  103373. **     *  A pointer to an Expr that represents an ID

  103374. **     *  The name of a table column in Column.zName

  103375. **

  103376. ** A list of RenameToken objects can be constructed during parsing.

  103377. ** Each new object is created by sqlite3RenameTokenMap().

  103378. ** As the parse tree is transformed, the sqlite3RenameTokenRemap()

  103379. ** routine is used to keep the mapping current.

  103380. **

  103381. ** After the parse finishes, renameTokenFind() routine can be used

  103382. ** to look up the actual token value that created some element in

  103383. ** the parse tree.

  103384. */

  103385. struct RenameToken {

  103386.   void *p;               /* Parse tree element created by token t */

  103387.   Token t;               /* The token that created parse tree element p */

  103388.   RenameToken *pNext;    /* Next is a list of all RenameToken objects */

  103389. };

  103390. 

  103391. /*

  103392. ** The context of an ALTER TABLE RENAME COLUMN operation that gets passed

  103393. ** down into the Walker.

  103394. */

  103395. typedef struct RenameCtx RenameCtx;

  103396. struct RenameCtx {

  103397.   RenameToken *pList;             /* List of tokens to overwrite */

  103398.   int nList;                      /* Number of tokens in pList */

  103399.   int iCol;                       /* Index of column being renamed */

  103400.   Table *pTab;                    /* Table being ALTERed */ 

  103401.   const char *zOld;               /* Old column name */

  103402. };

  103403. 

  103404. #ifdef SQLITE_DEBUG

  103405. /*

  103406. ** This function is only for debugging. It performs two tasks:

  103407. **

  103408. **   1. Checks that pointer pPtr does not already appear in the 

  103409. **      rename-token list.

  103410. **

  103411. **   2. Dereferences each pointer in the rename-token list.

  103412. **

  103413. ** The second is most effective when debugging under valgrind or

  103414. ** address-sanitizer or similar. If any of these pointers no longer 

  103415. ** point to valid objects, an exception is raised by the memory-checking 

  103416. ** tool.

  103417. **

  103418. ** The point of this is to prevent comparisons of invalid pointer values.

  103419. ** Even though this always seems to work, it is undefined according to the

  103420. ** C standard. Example of undefined comparison:

  103421. **

  103422. **     sqlite3_free(x);

  103423. **     if( x==y ) ...

  103424. **

  103425. ** Technically, as x no longer points into a valid object or to the byte

  103426. ** following a valid object, it may not be used in comparison operations.

  103427. */

  103428. static void renameTokenCheckAll(Parse *pParse, void *pPtr){

  103429.   if( pParse->nErr==0 && pParse->db->mallocFailed==0 ){

  103430.     RenameToken *p;

  103431.     u8 i = 0;

  103432.     for(p=pParse->pRename; p; p=p->pNext){

  103433.       if( p->p ){

  103434.         assert( p->p!=pPtr );

  103435.         i += *(u8*)(p->p);

  103436.       }

  103437.     }

  103438.   }

  103439. }

  103440. #else

  103441. # define renameTokenCheckAll(x,y)

  103442. #endif

  103443. 

  103444. /*

  103445. ** Remember that the parser tree element pPtr was created using

  103446. ** the token pToken.

  103447. **

  103448. ** In other words, construct a new RenameToken object and add it

  103449. ** to the list of RenameToken objects currently being built up

  103450. ** in pParse->pRename.

  103451. **

  103452. ** The pPtr argument is returned so that this routine can be used

  103453. ** with tail recursion in tokenExpr() routine, for a small performance

  103454. ** improvement.

  103455. */

  103456. SQLITE_PRIVATE void *sqlite3RenameTokenMap(Parse *pParse, void *pPtr, Token *pToken){

  103457.   RenameToken *pNew;

  103458.   assert( pPtr || pParse->db->mallocFailed );

  103459.   renameTokenCheckAll(pParse, pPtr);

  103460.   pNew = sqlite3DbMallocZero(pParse->db, sizeof(RenameToken));

  103461.   if( pNew ){

  103462.     pNew->p = pPtr;

  103463.     pNew->t = *pToken;

  103464.     pNew->pNext = pParse->pRename;

  103465.     pParse->pRename = pNew;

  103466.   }

  103467. 

  103468.   return pPtr;

  103469. }

  103470. 

  103471. /*

  103472. ** It is assumed that there is already a RenameToken object associated

  103473. ** with parse tree element pFrom. This function remaps the associated token

  103474. ** to parse tree element pTo.

  103475. */

  103476. SQLITE_PRIVATE void sqlite3RenameTokenRemap(Parse *pParse, void *pTo, void *pFrom){

  103477.   RenameToken *p;

  103478.   renameTokenCheckAll(pParse, pTo);

  103479.   for(p=pParse->pRename; p; p=p->pNext){

  103480.     if( p->p==pFrom ){

  103481.       p->p = pTo;

  103482.       break;

  103483.     }

  103484.   }

  103485. }

  103486. 

  103487. /*

  103488. ** Walker callback used by sqlite3RenameExprUnmap().

  103489. */

  103490. static int renameUnmapExprCb(Walker *pWalker, Expr *pExpr){

  103491.   Parse *pParse = pWalker->pParse;

  103492.   sqlite3RenameTokenRemap(pParse, 0, (void*)pExpr);

  103493.   return WRC_Continue;

  103494. }

  103495. 

  103496. /*

  103497. ** Walker callback used by sqlite3RenameExprUnmap().

  103498. */

  103499. static int renameUnmapSelectCb(Walker *pWalker, Select *p){

  103500.   Parse *pParse = pWalker->pParse;

  103501.   int i;

  103502.   if( ALWAYS(p->pEList) ){

  103503.     ExprList *pList = p->pEList;

  103504.     for(i=0; i<pList->nExpr; i++){

  103505.       if( pList->a[i].zName ){

  103506.         sqlite3RenameTokenRemap(pParse, 0, (void*)pList->a[i].zName);

  103507.       }

  103508.     }

  103509.   }

  103510.   if( ALWAYS(p->pSrc) ){  /* Every Select as a SrcList, even if it is empty */

  103511.     SrcList *pSrc = p->pSrc;

  103512.     for(i=0; i<pSrc->nSrc; i++){

  103513.       sqlite3RenameTokenRemap(pParse, 0, (void*)pSrc->a[i].zName);

  103514.     }

  103515.   }

  103516.   return WRC_Continue;

  103517. }

  103518. 

  103519. /*

  103520. ** Remove all nodes that are part of expression pExpr from the rename list.

  103521. */

  103522. SQLITE_PRIVATE void sqlite3RenameExprUnmap(Parse *pParse, Expr *pExpr){

  103523.   Walker sWalker;

  103524.   memset(&sWalker, 0, sizeof(Walker));

  103525.   sWalker.pParse = pParse;

  103526.   sWalker.xExprCallback = renameUnmapExprCb;

  103527.   sWalker.xSelectCallback = renameUnmapSelectCb;

  103528.   sqlite3WalkExpr(&sWalker, pExpr);

  103529. }

  103530. 

  103531. /*

  103532. ** Remove all nodes that are part of expression-list pEList from the 

  103533. ** rename list.

  103534. */

  103535. SQLITE_PRIVATE void sqlite3RenameExprlistUnmap(Parse *pParse, ExprList *pEList){

  103536.   if( pEList ){

  103537.     int i;

  103538.     Walker sWalker;

  103539.     memset(&sWalker, 0, sizeof(Walker));

  103540.     sWalker.pParse = pParse;

  103541.     sWalker.xExprCallback = renameUnmapExprCb;

  103542.     sqlite3WalkExprList(&sWalker, pEList);

  103543.     for(i=0; i<pEList->nExpr; i++){

  103544.       sqlite3RenameTokenRemap(pParse, 0, (void*)pEList->a[i].zName);

  103545.     }

  103546.   }

  103547. }

  103548. 

  103549. /*

  103550. ** Free the list of RenameToken objects given in the second argument

  103551. */

  103552. static void renameTokenFree(sqlite3 *db, RenameToken *pToken){

  103553.   RenameToken *pNext;

  103554.   RenameToken *p;

  103555.   for(p=pToken; p; p=pNext){

  103556.     pNext = p->pNext;

  103557.     sqlite3DbFree(db, p);

  103558.   }

  103559. }

  103560. 

  103561. /*

  103562. ** Search the Parse object passed as the first argument for a RenameToken

  103563. ** object associated with parse tree element pPtr. If found, remove it

  103564. ** from the Parse object and add it to the list maintained by the

  103565. ** RenameCtx object passed as the second argument.

  103566. */

  103567. static void renameTokenFind(Parse *pParse, struct RenameCtx *pCtx, void *pPtr){

  103568.   RenameToken **pp;

  103569.   assert( pPtr!=0 );

  103570.   for(pp=&pParse->pRename; (*pp); pp=&(*pp)->pNext){

  103571.     if( (*pp)->p==pPtr ){

  103572.       RenameToken *pToken = *pp;

  103573.       *pp = pToken->pNext;

  103574.       pToken->pNext = pCtx->pList;

  103575.       pCtx->pList = pToken;

  103576.       pCtx->nList++;

  103577.       break;

  103578.     }

  103579.   }

  103580. }

  103581. 

  103582. /*

  103583. ** Iterate through the Select objects that are part of WITH clauses attached

  103584. ** to select statement pSelect.

  103585. */

  103586. static void renameWalkWith(Walker *pWalker, Select *pSelect){

  103587.   if( pSelect->pWith ){

  103588.     int i;

  103589.     for(i=0; i<pSelect->pWith->nCte; i++){

  103590.       Select *p = pSelect->pWith->a[i].pSelect;

  103591.       NameContext sNC;

  103592.       memset(&sNC, 0, sizeof(sNC));

  103593.       sNC.pParse = pWalker->pParse;

  103594.       sqlite3SelectPrep(sNC.pParse, p, &sNC);

  103595.       sqlite3WalkSelect(pWalker, p);

  103596.     }

  103597.   }

  103598. }

  103599. 

  103600. /*

  103601. ** This is a Walker select callback. It does nothing. It is only required

  103602. ** because without a dummy callback, sqlite3WalkExpr() and similar do not

  103603. ** descend into sub-select statements.

  103604. */

  103605. static int renameColumnSelectCb(Walker *pWalker, Select *p){

  103606.   renameWalkWith(pWalker, p);

  103607.   return WRC_Continue;

  103608. }

  103609. 

  103610. /*

  103611. ** This is a Walker expression callback.

  103612. **

  103613. ** For every TK_COLUMN node in the expression tree, search to see

  103614. ** if the column being references is the column being renamed by an

  103615. ** ALTER TABLE statement.  If it is, then attach its associated

  103616. ** RenameToken object to the list of RenameToken objects being

  103617. ** constructed in RenameCtx object at pWalker->u.pRename.

  103618. */

  103619. static int renameColumnExprCb(Walker *pWalker, Expr *pExpr){

  103620.   RenameCtx *p = pWalker->u.pRename;

  103621.   if( pExpr->op==TK_TRIGGER 

  103622.    && pExpr->iColumn==p->iCol 

  103623.    && pWalker->pParse->pTriggerTab==p->pTab

  103624.   ){

  103625.     renameTokenFind(pWalker->pParse, p, (void*)pExpr);

  103626.   }else if( pExpr->op==TK_COLUMN 

  103627.    && pExpr->iColumn==p->iCol 

  103628.    && p->pTab==pExpr->y.pTab

  103629.   ){

  103630.     renameTokenFind(pWalker->pParse, p, (void*)pExpr);

  103631.   }

  103632.   return WRC_Continue;

  103633. }

  103634. 

  103635. /*

  103636. ** The RenameCtx contains a list of tokens that reference a column that

  103637. ** is being renamed by an ALTER TABLE statement.  Return the "last"

  103638. ** RenameToken in the RenameCtx and remove that RenameToken from the

  103639. ** RenameContext.  "Last" means the last RenameToken encountered when

  103640. ** the input SQL is parsed from left to right.  Repeated calls to this routine

  103641. ** return all column name tokens in the order that they are encountered

  103642. ** in the SQL statement.

  103643. */

  103644. static RenameToken *renameColumnTokenNext(RenameCtx *pCtx){

  103645.   RenameToken *pBest = pCtx->pList;

  103646.   RenameToken *pToken;

  103647.   RenameToken **pp;

  103648. 

  103649.   for(pToken=pBest->pNext; pToken; pToken=pToken->pNext){

  103650.     if( pToken->t.z>pBest->t.z ) pBest = pToken;

  103651.   }

  103652.   for(pp=&pCtx->pList; *pp!=pBest; pp=&(*pp)->pNext);

  103653.   *pp = pBest->pNext;

  103654. 

  103655.   return pBest;

  103656. }

  103657. 

  103658. /*

  103659. ** An error occured while parsing or otherwise processing a database

  103660. ** object (either pParse->pNewTable, pNewIndex or pNewTrigger) as part of an

  103661. ** ALTER TABLE RENAME COLUMN program. The error message emitted by the

  103662. ** sub-routine is currently stored in pParse->zErrMsg. This function

  103663. ** adds context to the error message and then stores it in pCtx.

  103664. */

  103665. static void renameColumnParseError(

  103666.   sqlite3_context *pCtx, 

  103667.   int bPost,

  103668.   sqlite3_value *pType,

  103669.   sqlite3_value *pObject,

  103670.   Parse *pParse

  103671. ){

  103672.   const char *zT = (const char*)sqlite3_value_text(pType);

  103673.   const char *zN = (const char*)sqlite3_value_text(pObject);

  103674.   char *zErr;

  103675. 

  103676.   zErr = sqlite3_mprintf("error in %s %s%s: %s", 

  103677.       zT, zN, (bPost ? " after rename" : ""),

  103678.       pParse->zErrMsg

  103679.   );

  103680.   sqlite3_result_error(pCtx, zErr, -1);

  103681.   sqlite3_free(zErr);

  103682. }

  103683. 

  103684. /*

  103685. ** For each name in the the expression-list pEList (i.e. each

  103686. ** pEList->a[i].zName) that matches the string in zOld, extract the 

  103687. ** corresponding rename-token from Parse object pParse and add it

  103688. ** to the RenameCtx pCtx.

  103689. */

  103690. static void renameColumnElistNames(

  103691.   Parse *pParse, 

  103692.   RenameCtx *pCtx, 

  103693.   ExprList *pEList, 

  103694.   const char *zOld

  103695. ){

  103696.   if( pEList ){

  103697.     int i;

  103698.     for(i=0; i<pEList->nExpr; i++){

  103699.       char *zName = pEList->a[i].zName;

  103700.       if( 0==sqlite3_stricmp(zName, zOld) ){

  103701.         renameTokenFind(pParse, pCtx, (void*)zName);

  103702.       }

  103703.     }

  103704.   }

  103705. }

  103706. 

  103707. /*

  103708. ** For each name in the the id-list pIdList (i.e. each pIdList->a[i].zName) 

  103709. ** that matches the string in zOld, extract the corresponding rename-token 

  103710. ** from Parse object pParse and add it to the RenameCtx pCtx.

  103711. */

  103712. static void renameColumnIdlistNames(

  103713.   Parse *pParse, 

  103714.   RenameCtx *pCtx, 

  103715.   IdList *pIdList, 

  103716.   const char *zOld

  103717. ){

  103718.   if( pIdList ){

  103719.     int i;

  103720.     for(i=0; i<pIdList->nId; i++){

  103721.       char *zName = pIdList->a[i].zName;

  103722.       if( 0==sqlite3_stricmp(zName, zOld) ){

  103723.         renameTokenFind(pParse, pCtx, (void*)zName);

  103724.       }

  103725.     }

  103726.   }

  103727. }

  103728. 

  103729. /*

  103730. ** Parse the SQL statement zSql using Parse object (*p). The Parse object

  103731. ** is initialized by this function before it is used.

  103732. */

  103733. static int renameParseSql(

  103734.   Parse *p,                       /* Memory to use for Parse object */

  103735.   const char *zDb,                /* Name of schema SQL belongs to */

  103736.   int bTable,                     /* 1 -> RENAME TABLE, 0 -> RENAME COLUMN */

  103737.   sqlite3 *db,                    /* Database handle */

  103738.   const char *zSql,               /* SQL to parse */

  103739.   int bTemp                       /* True if SQL is from temp schema */

  103740. ){

  103741.   int rc;

  103742.   char *zErr = 0;

  103743. 

  103744.   db->init.iDb = bTemp ? 1 : sqlite3FindDbName(db, zDb);

  103745. 

  103746.   /* Parse the SQL statement passed as the first argument. If no error

  103747.   ** occurs and the parse does not result in a new table, index or

  103748.   ** trigger object, the database must be corrupt. */

  103749.   memset(p, 0, sizeof(Parse));

  103750.   p->eParseMode = (bTable ? PARSE_MODE_RENAME_TABLE : PARSE_MODE_RENAME_COLUMN);

  103751.   p->db = db;

  103752.   p->nQueryLoop = 1;

  103753.   rc = sqlite3RunParser(p, zSql, &zErr);

  103754.   assert( p->zErrMsg==0 );

  103755.   assert( rc!=SQLITE_OK || zErr==0 );

  103756.   p->zErrMsg = zErr;

  103757.   if( db->mallocFailed ) rc = SQLITE_NOMEM;

  103758.   if( rc==SQLITE_OK 

  103759.    && p->pNewTable==0 && p->pNewIndex==0 && p->pNewTrigger==0 

  103760.   ){

  103761.     rc = SQLITE_CORRUPT_BKPT;

  103762.   }

  103763. 

  103764. #ifdef SQLITE_DEBUG

  103765.   /* Ensure that all mappings in the Parse.pRename list really do map to

  103766.   ** a part of the input string.  */

  103767.   if( rc==SQLITE_OK ){

  103768.     int nSql = sqlite3Strlen30(zSql);

  103769.     RenameToken *pToken;

  103770.     for(pToken=p->pRename; pToken; pToken=pToken->pNext){

  103771.       assert( pToken->t.z>=zSql && &pToken->t.z[pToken->t.n]<=&zSql[nSql] );

  103772.     }

  103773.   }

  103774. #endif

  103775. 

  103776.   db->init.iDb = 0;

  103777.   return rc;

  103778. }

  103779. 

  103780. /*

  103781. ** This function edits SQL statement zSql, replacing each token identified

  103782. ** by the linked list pRename with the text of zNew. If argument bQuote is

  103783. ** true, then zNew is always quoted first. If no error occurs, the result

  103784. ** is loaded into context object pCtx as the result.

  103785. **

  103786. ** Or, if an error occurs (i.e. an OOM condition), an error is left in

  103787. ** pCtx and an SQLite error code returned.

  103788. */

  103789. static int renameEditSql(

  103790.   sqlite3_context *pCtx,          /* Return result here */

  103791.   RenameCtx *pRename,             /* Rename context */

  103792.   const char *zSql,               /* SQL statement to edit */

  103793.   const char *zNew,               /* New token text */

  103794.   int bQuote                      /* True to always quote token */

  103795. ){

  103796.   int nNew = sqlite3Strlen30(zNew);

  103797.   int nSql = sqlite3Strlen30(zSql);

  103798.   sqlite3 *db = sqlite3_context_db_handle(pCtx);

  103799.   int rc = SQLITE_OK;

  103800.   char *zQuot;

  103801.   char *zOut;

  103802.   int nQuot;

  103803. 

  103804.   /* Set zQuot to point to a buffer containing a quoted copy of the 

  103805.   ** identifier zNew. If the corresponding identifier in the original 

  103806.   ** ALTER TABLE statement was quoted (bQuote==1), then set zNew to

  103807.   ** point to zQuot so that all substitutions are made using the

  103808.   ** quoted version of the new column name.  */

  103809.   zQuot = sqlite3MPrintf(db, "\"%w\"", zNew);

  103810.   if( zQuot==0 ){

  103811.     return SQLITE_NOMEM;

  103812.   }else{

  103813.     nQuot = sqlite3Strlen30(zQuot);

  103814.   }

  103815.   if( bQuote ){

  103816.     zNew = zQuot;

  103817.     nNew = nQuot;

  103818.   }

  103819. 

  103820.   /* At this point pRename->pList contains a list of RenameToken objects

  103821.   ** corresponding to all tokens in the input SQL that must be replaced

  103822.   ** with the new column name. All that remains is to construct and

  103823.   ** return the edited SQL string. */

  103824.   assert( nQuot>=nNew );

  103825.   zOut = sqlite3DbMallocZero(db, nSql + pRename->nList*nQuot + 1);

  103826.   if( zOut ){

  103827.     int nOut = nSql;

  103828.     memcpy(zOut, zSql, nSql);

  103829.     while( pRename->pList ){

  103830.       int iOff;                   /* Offset of token to replace in zOut */

  103831.       RenameToken *pBest = renameColumnTokenNext(pRename);

  103832. 

  103833.       u32 nReplace;

  103834.       const char *zReplace;

  103835.       if( sqlite3IsIdChar(*pBest->t.z) ){

  103836.         nReplace = nNew;

  103837.         zReplace = zNew;

  103838.       }else{

  103839.         nReplace = nQuot;

  103840.         zReplace = zQuot;

  103841.       }

  103842. 

  103843.       iOff = pBest->t.z - zSql;

  103844.       if( pBest->t.n!=nReplace ){

  103845.         memmove(&zOut[iOff + nReplace], &zOut[iOff + pBest->t.n], 

  103846.             nOut - (iOff + pBest->t.n)

  103847.         );

  103848.         nOut += nReplace - pBest->t.n;

  103849.         zOut[nOut] = '\0';

  103850.       }

  103851.       memcpy(&zOut[iOff], zReplace, nReplace);

  103852.       sqlite3DbFree(db, pBest);

  103853.     }

  103854. 

  103855.     sqlite3_result_text(pCtx, zOut, -1, SQLITE_TRANSIENT);

  103856.     sqlite3DbFree(db, zOut);

  103857.   }else{

  103858.     rc = SQLITE_NOMEM;

  103859.   }

  103860. 

  103861.   sqlite3_free(zQuot);

  103862.   return rc;

  103863. }

  103864. 

  103865. /*

  103866. ** Resolve all symbols in the trigger at pParse->pNewTrigger, assuming

  103867. ** it was read from the schema of database zDb. Return SQLITE_OK if 

  103868. ** successful. Otherwise, return an SQLite error code and leave an error

  103869. ** message in the Parse object.

  103870. */

  103871. static int renameResolveTrigger(Parse *pParse, const char *zDb){

  103872.   sqlite3 *db = pParse->db;

  103873.   Trigger *pNew = pParse->pNewTrigger;

  103874.   TriggerStep *pStep;

  103875.   NameContext sNC;

  103876.   int rc = SQLITE_OK;

  103877. 

  103878.   memset(&sNC, 0, sizeof(sNC));

  103879.   sNC.pParse = pParse;

  103880.   assert( pNew->pTabSchema );

  103881.   pParse->pTriggerTab = sqlite3FindTable(db, pNew->table, 

  103882.       db->aDb[sqlite3SchemaToIndex(db, pNew->pTabSchema)].zDbSName

  103883.   );

  103884.   pParse->eTriggerOp = pNew->op;

  103885.   /* ALWAYS() because if the table of the trigger does not exist, the

  103886.   ** error would have been hit before this point */

  103887.   if( ALWAYS(pParse->pTriggerTab) ){

  103888.     rc = sqlite3ViewGetColumnNames(pParse, pParse->pTriggerTab);

  103889.   }

  103890. 

  103891.   /* Resolve symbols in WHEN clause */

  103892.   if( rc==SQLITE_OK && pNew->pWhen ){

  103893.     rc = sqlite3ResolveExprNames(&sNC, pNew->pWhen);

  103894.   }

  103895. 

  103896.   for(pStep=pNew->step_list; rc==SQLITE_OK && pStep; pStep=pStep->pNext){

  103897.     if( pStep->pSelect ){

  103898.       sqlite3SelectPrep(pParse, pStep->pSelect, &sNC);

  103899.       if( pParse->nErr ) rc = pParse->rc;

  103900.     }

  103901.     if( rc==SQLITE_OK && pStep->zTarget ){

  103902.       Table *pTarget = sqlite3LocateTable(pParse, 0, pStep->zTarget, zDb);

  103903.       if( pTarget==0 ){

  103904.         rc = SQLITE_ERROR;

  103905.       }else if( SQLITE_OK==(rc = sqlite3ViewGetColumnNames(pParse, pTarget)) ){

  103906.         SrcList sSrc;

  103907.         memset(&sSrc, 0, sizeof(sSrc));

  103908.         sSrc.nSrc = 1;

  103909.         sSrc.a[0].zName = pStep->zTarget;

  103910.         sSrc.a[0].pTab = pTarget;

  103911.         sNC.pSrcList = &sSrc;

  103912.         if( pStep->pWhere ){

  103913.           rc = sqlite3ResolveExprNames(&sNC, pStep->pWhere);

  103914.         }

  103915.         if( rc==SQLITE_OK ){

  103916.           rc = sqlite3ResolveExprListNames(&sNC, pStep->pExprList);

  103917.         }

  103918.         assert( !pStep->pUpsert || (!pStep->pWhere && !pStep->pExprList) );

  103919.         if( pStep->pUpsert ){

  103920.           Upsert *pUpsert = pStep->pUpsert;

  103921.           assert( rc==SQLITE_OK );

  103922.           pUpsert->pUpsertSrc = &sSrc;

  103923.           sNC.uNC.pUpsert = pUpsert;

  103924.           sNC.ncFlags = NC_UUpsert;

  103925.           rc = sqlite3ResolveExprListNames(&sNC, pUpsert->pUpsertTarget);

  103926.           if( rc==SQLITE_OK ){

  103927.             ExprList *pUpsertSet = pUpsert->pUpsertSet;

  103928.             rc = sqlite3ResolveExprListNames(&sNC, pUpsertSet);

  103929.           }

  103930.           if( rc==SQLITE_OK ){

  103931.             rc = sqlite3ResolveExprNames(&sNC, pUpsert->pUpsertWhere);

  103932.           }

  103933.           if( rc==SQLITE_OK ){

  103934.             rc = sqlite3ResolveExprNames(&sNC, pUpsert->pUpsertTargetWhere);

  103935.           }

  103936.           sNC.ncFlags = 0;

  103937.         }

  103938.         sNC.pSrcList = 0;

  103939.       }

  103940.     }

  103941.   }

  103942.   return rc;

  103943. }

  103944. 

  103945. /*

  103946. ** Invoke sqlite3WalkExpr() or sqlite3WalkSelect() on all Select or Expr

  103947. ** objects that are part of the trigger passed as the second argument.

  103948. */

  103949. static void renameWalkTrigger(Walker *pWalker, Trigger *pTrigger){

  103950.   TriggerStep *pStep;

  103951. 

  103952.   /* Find tokens to edit in WHEN clause */

  103953.   sqlite3WalkExpr(pWalker, pTrigger->pWhen);

  103954. 

  103955.   /* Find tokens to edit in trigger steps */

  103956.   for(pStep=pTrigger->step_list; pStep; pStep=pStep->pNext){

  103957.     sqlite3WalkSelect(pWalker, pStep->pSelect);

  103958.     sqlite3WalkExpr(pWalker, pStep->pWhere);

  103959.     sqlite3WalkExprList(pWalker, pStep->pExprList);

  103960.     if( pStep->pUpsert ){

  103961.       Upsert *pUpsert = pStep->pUpsert;

  103962.       sqlite3WalkExprList(pWalker, pUpsert->pUpsertTarget);

  103963.       sqlite3WalkExprList(pWalker, pUpsert->pUpsertSet);

  103964.       sqlite3WalkExpr(pWalker, pUpsert->pUpsertWhere);

  103965.       sqlite3WalkExpr(pWalker, pUpsert->pUpsertTargetWhere);

  103966.     }

  103967.   }

  103968. }

  103969. 

  103970. /*

  103971. ** Free the contents of Parse object (*pParse). Do not free the memory

  103972. ** occupied by the Parse object itself.

  103973. */

  103974. static void renameParseCleanup(Parse *pParse){

  103975.   sqlite3 *db = pParse->db;

  103976.   Index *pIdx;

  103977.   if( pParse->pVdbe ){

  103978.     sqlite3VdbeFinalize(pParse->pVdbe);

  103979.   }

  103980.   sqlite3DeleteTable(db, pParse->pNewTable);

  103981.   while( (pIdx = pParse->pNewIndex)!=0 ){

  103982.     pParse->pNewIndex = pIdx->pNext;

  103983.     sqlite3FreeIndex(db, pIdx);

  103984.   }

  103985.   sqlite3DeleteTrigger(db, pParse->pNewTrigger);

  103986.   sqlite3DbFree(db, pParse->zErrMsg);

  103987.   renameTokenFree(db, pParse->pRename);

  103988.   sqlite3ParserReset(pParse);

  103989. }

  103990. 

  103991. /*

  103992. ** SQL function:

  103993. **

  103994. **     sqlite_rename_column(zSql, iCol, bQuote, zNew, zTable, zOld)

  103995. **

  103996. **   0. zSql:     SQL statement to rewrite

  103997. **   1. type:     Type of object ("table", "view" etc.)

  103998. **   2. object:   Name of object

  103999. **   3. Database: Database name (e.g. "main")

  104000. **   4. Table:    Table name

  104001. **   5. iCol:     Index of column to rename

  104002. **   6. zNew:     New column name

  104003. **   7. bQuote:   Non-zero if the new column name should be quoted.

  104004. **   8. bTemp:    True if zSql comes from temp schema

  104005. **

  104006. ** Do a column rename operation on the CREATE statement given in zSql.

  104007. ** The iCol-th column (left-most is 0) of table zTable is renamed from zCol

  104008. ** into zNew.  The name should be quoted if bQuote is true.

  104009. **

  104010. ** This function is used internally by the ALTER TABLE RENAME COLUMN command.

  104011. ** It is only accessible to SQL created using sqlite3NestedParse().  It is

  104012. ** not reachable from ordinary SQL passed into sqlite3_prepare().

  104013. */

  104014. static void renameColumnFunc(

  104015.   sqlite3_context *context,

  104016.   int NotUsed,

  104017.   sqlite3_value **argv

  104018. ){

  104019.   sqlite3 *db = sqlite3_context_db_handle(context);

  104020.   RenameCtx sCtx;

  104021.   const char *zSql = (const char*)sqlite3_value_text(argv[0]);

  104022.   const char *zDb = (const char*)sqlite3_value_text(argv[3]);

  104023.   const char *zTable = (const char*)sqlite3_value_text(argv[4]);

  104024.   int iCol = sqlite3_value_int(argv[5]);

  104025.   const char *zNew = (const char*)sqlite3_value_text(argv[6]);

  104026.   int bQuote = sqlite3_value_int(argv[7]);

  104027.   int bTemp = sqlite3_value_int(argv[8]);

  104028.   const char *zOld;

  104029.   int rc;

  104030.   Parse sParse;

  104031.   Walker sWalker;

  104032.   Index *pIdx;

  104033.   int i;

  104034.   Table *pTab;

  104035. #ifndef SQLITE_OMIT_AUTHORIZATION

  104036.   sqlite3_xauth xAuth = db->xAuth;

  104037. #endif

  104038. 

  104039.   UNUSED_PARAMETER(NotUsed);

  104040.   if( zSql==0 ) return;

  104041.   if( zTable==0 ) return;

  104042.   if( zNew==0 ) return;

  104043.   if( iCol<0 ) return;

  104044.   sqlite3BtreeEnterAll(db);

  104045.   pTab = sqlite3FindTable(db, zTable, zDb);

  104046.   if( pTab==0 || iCol>=pTab->nCol ){

  104047.     sqlite3BtreeLeaveAll(db);

  104048.     return;

  104049.   }

  104050.   zOld = pTab->aCol[iCol].zName;

  104051.   memset(&sCtx, 0, sizeof(sCtx));

  104052.   sCtx.iCol = ((iCol==pTab->iPKey) ? -1 : iCol);

  104053. 

  104054. #ifndef SQLITE_OMIT_AUTHORIZATION

  104055.   db->xAuth = 0;

  104056. #endif

  104057.   rc = renameParseSql(&sParse, zDb, 0, db, zSql, bTemp);

  104058. 

  104059.   /* Find tokens that need to be replaced. */

  104060.   memset(&sWalker, 0, sizeof(Walker));

  104061.   sWalker.pParse = &sParse;

  104062.   sWalker.xExprCallback = renameColumnExprCb;

  104063.   sWalker.xSelectCallback = renameColumnSelectCb;

  104064.   sWalker.u.pRename = &sCtx;

  104065. 

  104066.   sCtx.pTab = pTab;

  104067.   if( rc!=SQLITE_OK ) goto renameColumnFunc_done;

  104068.   if( sParse.pNewTable ){

  104069.     Select *pSelect = sParse.pNewTable->pSelect;

  104070.     if( pSelect ){

  104071.       sParse.rc = SQLITE_OK;

  104072.       sqlite3SelectPrep(&sParse, sParse.pNewTable->pSelect, 0);

  104073.       rc = (db->mallocFailed ? SQLITE_NOMEM : sParse.rc);

  104074.       if( rc==SQLITE_OK ){

  104075.         sqlite3WalkSelect(&sWalker, pSelect);

  104076.       }

  104077.       if( rc!=SQLITE_OK ) goto renameColumnFunc_done;

  104078.     }else{

  104079.       /* A regular table */

  104080.       int bFKOnly = sqlite3_stricmp(zTable, sParse.pNewTable->zName);

  104081.       FKey *pFKey;

  104082.       assert( sParse.pNewTable->pSelect==0 );

  104083.       sCtx.pTab = sParse.pNewTable;

  104084.       if( bFKOnly==0 ){

  104085.         renameTokenFind(

  104086.             &sParse, &sCtx, (void*)sParse.pNewTable->aCol[iCol].zName

  104087.         );

  104088.         if( sCtx.iCol<0 ){

  104089.           renameTokenFind(&sParse, &sCtx, (void*)&sParse.pNewTable->iPKey);

  104090.         }

  104091.         sqlite3WalkExprList(&sWalker, sParse.pNewTable->pCheck);

  104092.         for(pIdx=sParse.pNewTable->pIndex; pIdx; pIdx=pIdx->pNext){

  104093.           sqlite3WalkExprList(&sWalker, pIdx->aColExpr);

  104094.         }

  104095.         for(pIdx=sParse.pNewIndex; pIdx; pIdx=pIdx->pNext){

  104096.           sqlite3WalkExprList(&sWalker, pIdx->aColExpr);

  104097.         }

  104098.       }

  104099. 

  104100.       for(pFKey=sParse.pNewTable->pFKey; pFKey; pFKey=pFKey->pNextFrom){

  104101.         for(i=0; i<pFKey->nCol; i++){

  104102.           if( bFKOnly==0 && pFKey->aCol[i].iFrom==iCol ){

  104103.             renameTokenFind(&sParse, &sCtx, (void*)&pFKey->aCol[i]);

  104104.           }

  104105.           if( 0==sqlite3_stricmp(pFKey->zTo, zTable)

  104106.            && 0==sqlite3_stricmp(pFKey->aCol[i].zCol, zOld)

  104107.           ){

  104108.             renameTokenFind(&sParse, &sCtx, (void*)pFKey->aCol[i].zCol);

  104109.           }

  104110.         }

  104111.       }

  104112.     }

  104113.   }else if( sParse.pNewIndex ){

  104114.     sqlite3WalkExprList(&sWalker, sParse.pNewIndex->aColExpr);

  104115.     sqlite3WalkExpr(&sWalker, sParse.pNewIndex->pPartIdxWhere);

  104116.   }else{

  104117.     /* A trigger */

  104118.     TriggerStep *pStep;

  104119.     rc = renameResolveTrigger(&sParse, (bTemp ? 0 : zDb));

  104120.     if( rc!=SQLITE_OK ) goto renameColumnFunc_done;

  104121. 

  104122.     for(pStep=sParse.pNewTrigger->step_list; pStep; pStep=pStep->pNext){

  104123.       if( pStep->zTarget ){ 

  104124.         Table *pTarget = sqlite3LocateTable(&sParse, 0, pStep->zTarget, zDb);

  104125.         if( pTarget==pTab ){

  104126.           if( pStep->pUpsert ){

  104127.             ExprList *pUpsertSet = pStep->pUpsert->pUpsertSet;

  104128.             renameColumnElistNames(&sParse, &sCtx, pUpsertSet, zOld);

  104129.           }

  104130.           renameColumnIdlistNames(&sParse, &sCtx, pStep->pIdList, zOld);

  104131.           renameColumnElistNames(&sParse, &sCtx, pStep->pExprList, zOld);

  104132.         }

  104133.       }

  104134.     }

  104135. 

  104136. 

  104137.     /* Find tokens to edit in UPDATE OF clause */

  104138.     if( sParse.pTriggerTab==pTab ){

  104139.       renameColumnIdlistNames(&sParse, &sCtx,sParse.pNewTrigger->pColumns,zOld);

  104140.     }

  104141. 

  104142.     /* Find tokens to edit in various expressions and selects */

  104143.     renameWalkTrigger(&sWalker, sParse.pNewTrigger);

  104144.   }

  104145. 

  104146.   assert( rc==SQLITE_OK );

  104147.   rc = renameEditSql(context, &sCtx, zSql, zNew, bQuote);

  104148. 

  104149. renameColumnFunc_done:

  104150.   if( rc!=SQLITE_OK ){

  104151.     if( sParse.zErrMsg ){

  104152.       renameColumnParseError(context, 0, argv[1], argv[2], &sParse);

  104153.     }else{

  104154.       sqlite3_result_error_code(context, rc);

  104155.     }

  104156.   }

  104157. 

  104158.   renameParseCleanup(&sParse);

  104159.   renameTokenFree(db, sCtx.pList);

  104160. #ifndef SQLITE_OMIT_AUTHORIZATION

  104161.   db->xAuth = xAuth;

  104162. #endif

  104163.   sqlite3BtreeLeaveAll(db);

  104164. }

  104165. 

  104166. /*

  104167. ** Walker expression callback used by "RENAME TABLE". 

  104168. */

  104169. static int renameTableExprCb(Walker *pWalker, Expr *pExpr){

  104170.   RenameCtx *p = pWalker->u.pRename;

  104171.   if( pExpr->op==TK_COLUMN && p->pTab==pExpr->y.pTab ){

  104172.     renameTokenFind(pWalker->pParse, p, (void*)&pExpr->y.pTab);

  104173.   }

  104174.   return WRC_Continue;

  104175. }

  104176. 

  104177. /*

  104178. ** Walker select callback used by "RENAME TABLE". 

  104179. */

  104180. static int renameTableSelectCb(Walker *pWalker, Select *pSelect){

  104181.   int i;

  104182.   RenameCtx *p = pWalker->u.pRename;

  104183.   SrcList *pSrc = pSelect->pSrc;

  104184.   if( pSrc==0 ){

  104185.     assert( pWalker->pParse->db->mallocFailed );

  104186.     return WRC_Abort;

  104187.   }

  104188.   for(i=0; i<pSrc->nSrc; i++){

  104189.     struct SrcList_item *pItem = &pSrc->a[i];

  104190.     if( pItem->pTab==p->pTab ){

  104191.       renameTokenFind(pWalker->pParse, p, pItem->zName);

  104192.     }

  104193.   }

  104194.   renameWalkWith(pWalker, pSelect);

  104195. 

  104196.   return WRC_Continue;

  104197. }

  104198. 

  104199. 

  104200. /*

  104201. ** This C function implements an SQL user function that is used by SQL code

  104202. ** generated by the ALTER TABLE ... RENAME command to modify the definition

  104203. ** of any foreign key constraints that use the table being renamed as the 

  104204. ** parent table. It is passed three arguments:

  104205. **

  104206. **   0: The database containing the table being renamed.

  104207. **   1. type:     Type of object ("table", "view" etc.)

  104208. **   2. object:   Name of object

  104209. **   3: The complete text of the schema statement being modified,

  104210. **   4: The old name of the table being renamed, and

  104211. **   5: The new name of the table being renamed.

  104212. **   6: True if the schema statement comes from the temp db.

  104213. **

  104214. ** It returns the new schema statement. For example:

  104215. **

  104216. ** sqlite_rename_table('main', 'CREATE TABLE t1(a REFERENCES t2)','t2','t3',0)

  104217. **       -> 'CREATE TABLE t1(a REFERENCES t3)'

  104218. */

  104219. static void renameTableFunc(

  104220.   sqlite3_context *context,

  104221.   int NotUsed,

  104222.   sqlite3_value **argv

  104223. ){

  104224.   sqlite3 *db = sqlite3_context_db_handle(context);

  104225.   const char *zDb = (const char*)sqlite3_value_text(argv[0]);

  104226.   const char *zInput = (const char*)sqlite3_value_text(argv[3]);

  104227.   const char *zOld = (const char*)sqlite3_value_text(argv[4]);

  104228.   const char *zNew = (const char*)sqlite3_value_text(argv[5]);

  104229.   int bTemp = sqlite3_value_int(argv[6]);

  104230.   UNUSED_PARAMETER(NotUsed);

  104231. 

  104232.   if( zInput && zOld && zNew ){

  104233.     Parse sParse;

  104234.     int rc;

  104235.     int bQuote = 1;

  104236.     RenameCtx sCtx;

  104237.     Walker sWalker;

  104238. 

  104239. #ifndef SQLITE_OMIT_AUTHORIZATION

  104240.     sqlite3_xauth xAuth = db->xAuth;

  104241.     db->xAuth = 0;

  104242. #endif

  104243. 

  104244.     sqlite3BtreeEnterAll(db);

  104245. 

  104246.     memset(&sCtx, 0, sizeof(RenameCtx));

  104247.     sCtx.pTab = sqlite3FindTable(db, zOld, zDb);

  104248.     memset(&sWalker, 0, sizeof(Walker));

  104249.     sWalker.pParse = &sParse;

  104250.     sWalker.xExprCallback = renameTableExprCb;

  104251.     sWalker.xSelectCallback = renameTableSelectCb;

  104252.     sWalker.u.pRename = &sCtx;

  104253. 

  104254.     rc = renameParseSql(&sParse, zDb, 1, db, zInput, bTemp);

  104255. 

  104256.     if( rc==SQLITE_OK ){

  104257.       int isLegacy = (db->flags & SQLITE_LegacyAlter);

  104258.       if( sParse.pNewTable ){

  104259.         Table *pTab = sParse.pNewTable;

  104260. 

  104261.         if( pTab->pSelect ){

  104262.           if( isLegacy==0 ){

  104263.             NameContext sNC;

  104264.             memset(&sNC, 0, sizeof(sNC));

  104265.             sNC.pParse = &sParse;

  104266. 

  104267.             sqlite3SelectPrep(&sParse, pTab->pSelect, &sNC);

  104268.             if( sParse.nErr ) rc = sParse.rc;

  104269.             sqlite3WalkSelect(&sWalker, pTab->pSelect);

  104270.           }

  104271.         }else{

  104272.           /* Modify any FK definitions to point to the new table. */

  104273. #ifndef SQLITE_OMIT_FOREIGN_KEY

  104274.           if( isLegacy==0 || (db->flags & SQLITE_ForeignKeys) ){

  104275.             FKey *pFKey;

  104276.             for(pFKey=pTab->pFKey; pFKey; pFKey=pFKey->pNextFrom){

  104277.               if( sqlite3_stricmp(pFKey->zTo, zOld)==0 ){

  104278.                 renameTokenFind(&sParse, &sCtx, (void*)pFKey->zTo);

  104279.               }

  104280.             }

  104281.           }

  104282. #endif

  104283. 

  104284.           /* If this is the table being altered, fix any table refs in CHECK

  104285.           ** expressions. Also update the name that appears right after the

  104286.           ** "CREATE [VIRTUAL] TABLE" bit. */

  104287.           if( sqlite3_stricmp(zOld, pTab->zName)==0 ){

  104288.             sCtx.pTab = pTab;

  104289.             if( isLegacy==0 ){

  104290.               sqlite3WalkExprList(&sWalker, pTab->pCheck);

  104291.             }

  104292.             renameTokenFind(&sParse, &sCtx, pTab->zName);

  104293.           }

  104294.         }

  104295.       }

  104296. 

  104297.       else if( sParse.pNewIndex ){

  104298.         renameTokenFind(&sParse, &sCtx, sParse.pNewIndex->zName);

  104299.         if( isLegacy==0 ){

  104300.           sqlite3WalkExpr(&sWalker, sParse.pNewIndex->pPartIdxWhere);

  104301.         }

  104302.       }

  104303. 

  104304. #ifndef SQLITE_OMIT_TRIGGER

  104305.       else{

  104306.         Trigger *pTrigger = sParse.pNewTrigger;

  104307.         TriggerStep *pStep;

  104308.         if( 0==sqlite3_stricmp(sParse.pNewTrigger->table, zOld) 

  104309.             && sCtx.pTab->pSchema==pTrigger->pTabSchema

  104310.           ){

  104311.           renameTokenFind(&sParse, &sCtx, sParse.pNewTrigger->table);

  104312.         }

  104313. 

  104314.         if( isLegacy==0 ){

  104315.           rc = renameResolveTrigger(&sParse, bTemp ? 0 : zDb);

  104316.           if( rc==SQLITE_OK ){

  104317.             renameWalkTrigger(&sWalker, pTrigger);

  104318.             for(pStep=pTrigger->step_list; pStep; pStep=pStep->pNext){

  104319.               if( pStep->zTarget && 0==sqlite3_stricmp(pStep->zTarget, zOld) ){

  104320.                 renameTokenFind(&sParse, &sCtx, pStep->zTarget);

  104321.               }

  104322.             }

  104323.           }

  104324.         }

  104325.       }

  104326. #endif

  104327.     }

  104328. 

  104329.     if( rc==SQLITE_OK ){

  104330.       rc = renameEditSql(context, &sCtx, zInput, zNew, bQuote);

  104331.     }

  104332.     if( rc!=SQLITE_OK ){

  104333.       if( sParse.zErrMsg ){

  104334.         renameColumnParseError(context, 0, argv[1], argv[2], &sParse);

  104335.       }else{

  104336.         sqlite3_result_error_code(context, rc);

  104337.       }

  104338.     }

  104339. 

  104340.     renameParseCleanup(&sParse);

  104341.     renameTokenFree(db, sCtx.pList);

  104342.     sqlite3BtreeLeaveAll(db);

  104343. #ifndef SQLITE_OMIT_AUTHORIZATION

  104344.     db->xAuth = xAuth;

  104345. #endif

  104346.   }

  104347. 

  104348.   return;

  104349. }

  104350. 

  104351. /*

  104352. ** An SQL user function that checks that there are no parse or symbol

  104353. ** resolution problems in a CREATE TRIGGER|TABLE|VIEW|INDEX statement.

  104354. ** After an ALTER TABLE .. RENAME operation is performed and the schema

  104355. ** reloaded, this function is called on each SQL statement in the schema

  104356. ** to ensure that it is still usable.

  104357. **

  104358. **   0: Database name ("main", "temp" etc.).

  104359. **   1: SQL statement.

  104360. **   2: Object type ("view", "table", "trigger" or "index").

  104361. **   3: Object name.

  104362. **   4: True if object is from temp schema.

  104363. **

  104364. ** Unless it finds an error, this function normally returns NULL. However, it

  104365. ** returns integer value 1 if:

  104366. **

  104367. **   * the SQL argument creates a trigger, and

  104368. **   * the table that the trigger is attached to is in database zDb.

  104369. */

  104370. static void renameTableTest(

  104371.   sqlite3_context *context,

  104372.   int NotUsed,

  104373.   sqlite3_value **argv

  104374. ){

  104375.   sqlite3 *db = sqlite3_context_db_handle(context);

  104376.   char const *zDb = (const char*)sqlite3_value_text(argv[0]);

  104377.   char const *zInput = (const char*)sqlite3_value_text(argv[1]);

  104378.   int bTemp = sqlite3_value_int(argv[4]);

  104379.   int isLegacy = (db->flags & SQLITE_LegacyAlter);

  104380. 

  104381. #ifndef SQLITE_OMIT_AUTHORIZATION

  104382.   sqlite3_xauth xAuth = db->xAuth;

  104383.   db->xAuth = 0;

  104384. #endif

  104385. 

  104386.   UNUSED_PARAMETER(NotUsed);

  104387.   if( zDb && zInput ){

  104388.     int rc;

  104389.     Parse sParse;

  104390.     rc = renameParseSql(&sParse, zDb, 1, db, zInput, bTemp);

  104391.     if( rc==SQLITE_OK ){

  104392.       if( isLegacy==0 && sParse.pNewTable && sParse.pNewTable->pSelect ){

  104393.         NameContext sNC;

  104394.         memset(&sNC, 0, sizeof(sNC));

  104395.         sNC.pParse = &sParse;

  104396.         sqlite3SelectPrep(&sParse, sParse.pNewTable->pSelect, &sNC);

  104397.         if( sParse.nErr ) rc = sParse.rc;

  104398.       }

  104399. 

  104400.       else if( sParse.pNewTrigger ){

  104401.         if( isLegacy==0 ){

  104402.           rc = renameResolveTrigger(&sParse, bTemp ? 0 : zDb);

  104403.         }

  104404.         if( rc==SQLITE_OK ){

  104405.           int i1 = sqlite3SchemaToIndex(db, sParse.pNewTrigger->pTabSchema);

  104406.           int i2 = sqlite3FindDbName(db, zDb);

  104407.           if( i1==i2 ) sqlite3_result_int(context, 1);

  104408.         }

  104409.       }

  104410.     }

  104411. 

  104412.     if( rc!=SQLITE_OK ){

  104413.       renameColumnParseError(context, 1, argv[2], argv[3], &sParse);

  104414.     }

  104415.     renameParseCleanup(&sParse);

  104416.   }

  104417. 

  104418. #ifndef SQLITE_OMIT_AUTHORIZATION

  104419.   db->xAuth = xAuth;

  104420. #endif

  104421. }

  104422. 

  104423. /*

  104424. ** Register built-in functions used to help implement ALTER TABLE

  104425. */

  104426. SQLITE_PRIVATE void sqlite3AlterFunctions(void){

  104427.   static FuncDef aAlterTableFuncs[] = {

  104428.     INTERNAL_FUNCTION(sqlite_rename_column, 9, renameColumnFunc),

  104429.     INTERNAL_FUNCTION(sqlite_rename_table,  7, renameTableFunc),

  104430.     INTERNAL_FUNCTION(sqlite_rename_test,   5, renameTableTest),

  104431.   };

  104432.   sqlite3InsertBuiltinFuncs(aAlterTableFuncs, ArraySize(aAlterTableFuncs));

  104433. }

  104434. #endif  /* SQLITE_ALTER_TABLE */

  104435. 

  104436. /************** End of alter.c ***********************************************/

  104437. /************** Begin file analyze.c *****************************************/

  104438. /*

  104439. ** 2005-07-08

  104440. **

  104441. ** The author disclaims copyright to this source code.  In place of

  104442. ** a legal notice, here is a blessing:

  104443. **

  104444. **    May you do good and not evil.

  104445. **    May you find forgiveness for yourself and forgive others.

  104446. **    May you share freely, never taking more than you give.

  104447. **

  104448. *************************************************************************

  104449. ** This file contains code associated with the ANALYZE command.

  104450. **

  104451. ** The ANALYZE command gather statistics about the content of tables

  104452. ** and indices.  These statistics are made available to the query planner

  104453. ** to help it make better decisions about how to perform queries.

  104454. **

  104455. ** The following system tables are or have been supported:

  104456. **

  104457. **    CREATE TABLE sqlite_stat1(tbl, idx, stat);

  104458. **    CREATE TABLE sqlite_stat2(tbl, idx, sampleno, sample);

  104459. **    CREATE TABLE sqlite_stat3(tbl, idx, nEq, nLt, nDLt, sample);

  104460. **    CREATE TABLE sqlite_stat4(tbl, idx, nEq, nLt, nDLt, sample);

  104461. **

  104462. ** Additional tables might be added in future releases of SQLite.

  104463. ** The sqlite_stat2 table is not created or used unless the SQLite version

  104464. ** is between 3.6.18 and 3.7.8, inclusive, and unless SQLite is compiled

  104465. ** with SQLITE_ENABLE_STAT2.  The sqlite_stat2 table is deprecated.

  104466. ** The sqlite_stat2 table is superseded by sqlite_stat3, which is only

  104467. ** created and used by SQLite versions 3.7.9 and later and with

  104468. ** SQLITE_ENABLE_STAT3 defined.  The functionality of sqlite_stat3

  104469. ** is a superset of sqlite_stat2.  The sqlite_stat4 is an enhanced

  104470. ** version of sqlite_stat3 and is only available when compiled with

  104471. ** SQLITE_ENABLE_STAT4 and in SQLite versions 3.8.1 and later.  It is

  104472. ** not possible to enable both STAT3 and STAT4 at the same time.  If they

  104473. ** are both enabled, then STAT4 takes precedence.

  104474. **

  104475. ** For most applications, sqlite_stat1 provides all the statistics required

  104476. ** for the query planner to make good choices.

  104477. **

  104478. ** Format of sqlite_stat1:

  104479. **

  104480. ** There is normally one row per index, with the index identified by the

  104481. ** name in the idx column.  The tbl column is the name of the table to

  104482. ** which the index belongs.  In each such row, the stat column will be

  104483. ** a string consisting of a list of integers.  The first integer in this

  104484. ** list is the number of rows in the index.  (This is the same as the

  104485. ** number of rows in the table, except for partial indices.)  The second

  104486. ** integer is the average number of rows in the index that have the same

  104487. ** value in the first column of the index.  The third integer is the average

  104488. ** number of rows in the index that have the same value for the first two

  104489. ** columns.  The N-th integer (for N>1) is the average number of rows in 

  104490. ** the index which have the same value for the first N-1 columns.  For

  104491. ** a K-column index, there will be K+1 integers in the stat column.  If

  104492. ** the index is unique, then the last integer will be 1.

  104493. **

  104494. ** The list of integers in the stat column can optionally be followed

  104495. ** by the keyword "unordered".  The "unordered" keyword, if it is present,

  104496. ** must be separated from the last integer by a single space.  If the

  104497. ** "unordered" keyword is present, then the query planner assumes that

  104498. ** the index is unordered and will not use the index for a range query.

  104499. ** 

  104500. ** If the sqlite_stat1.idx column is NULL, then the sqlite_stat1.stat

  104501. ** column contains a single integer which is the (estimated) number of

  104502. ** rows in the table identified by sqlite_stat1.tbl.

  104503. **

  104504. ** Format of sqlite_stat2:

  104505. **

  104506. ** The sqlite_stat2 is only created and is only used if SQLite is compiled

  104507. ** with SQLITE_ENABLE_STAT2 and if the SQLite version number is between

  104508. ** 3.6.18 and 3.7.8.  The "stat2" table contains additional information

  104509. ** about the distribution of keys within an index.  The index is identified by

  104510. ** the "idx" column and the "tbl" column is the name of the table to which

  104511. ** the index belongs.  There are usually 10 rows in the sqlite_stat2

  104512. ** table for each index.

  104513. **

  104514. ** The sqlite_stat2 entries for an index that have sampleno between 0 and 9

  104515. ** inclusive are samples of the left-most key value in the index taken at

  104516. ** evenly spaced points along the index.  Let the number of samples be S

  104517. ** (10 in the standard build) and let C be the number of rows in the index.

  104518. ** Then the sampled rows are given by:

  104519. **

  104520. **     rownumber = (i*C*2 + C)/(S*2)

  104521. **

  104522. ** For i between 0 and S-1.  Conceptually, the index space is divided into

  104523. ** S uniform buckets and the samples are the middle row from each bucket.

  104524. **

  104525. ** The format for sqlite_stat2 is recorded here for legacy reference.  This

  104526. ** version of SQLite does not support sqlite_stat2.  It neither reads nor

  104527. ** writes the sqlite_stat2 table.  This version of SQLite only supports

  104528. ** sqlite_stat3.

  104529. **

  104530. ** Format for sqlite_stat3:

  104531. **

  104532. ** The sqlite_stat3 format is a subset of sqlite_stat4.  Hence, the

  104533. ** sqlite_stat4 format will be described first.  Further information

  104534. ** about sqlite_stat3 follows the sqlite_stat4 description.

  104535. **

  104536. ** Format for sqlite_stat4:

  104537. **

  104538. ** As with sqlite_stat2, the sqlite_stat4 table contains histogram data

  104539. ** to aid the query planner in choosing good indices based on the values

  104540. ** that indexed columns are compared against in the WHERE clauses of

  104541. ** queries.

  104542. **

  104543. ** The sqlite_stat4 table contains multiple entries for each index.

  104544. ** The idx column names the index and the tbl column is the table of the

  104545. ** index.  If the idx and tbl columns are the same, then the sample is

  104546. ** of the INTEGER PRIMARY KEY.  The sample column is a blob which is the

  104547. ** binary encoding of a key from the index.  The nEq column is a

  104548. ** list of integers.  The first integer is the approximate number

  104549. ** of entries in the index whose left-most column exactly matches

  104550. ** the left-most column of the sample.  The second integer in nEq

  104551. ** is the approximate number of entries in the index where the

  104552. ** first two columns match the first two columns of the sample.

  104553. ** And so forth.  nLt is another list of integers that show the approximate

  104554. ** number of entries that are strictly less than the sample.  The first

  104555. ** integer in nLt contains the number of entries in the index where the

  104556. ** left-most column is less than the left-most column of the sample.

  104557. ** The K-th integer in the nLt entry is the number of index entries 

  104558. ** where the first K columns are less than the first K columns of the

  104559. ** sample.  The nDLt column is like nLt except that it contains the 

  104560. ** number of distinct entries in the index that are less than the

  104561. ** sample.

  104562. **

  104563. ** There can be an arbitrary number of sqlite_stat4 entries per index.

  104564. ** The ANALYZE command will typically generate sqlite_stat4 tables

  104565. ** that contain between 10 and 40 samples which are distributed across

  104566. ** the key space, though not uniformly, and which include samples with

  104567. ** large nEq values.

  104568. **

  104569. ** Format for sqlite_stat3 redux:

  104570. **

  104571. ** The sqlite_stat3 table is like sqlite_stat4 except that it only

  104572. ** looks at the left-most column of the index.  The sqlite_stat3.sample

  104573. ** column contains the actual value of the left-most column instead

  104574. ** of a blob encoding of the complete index key as is found in

  104575. ** sqlite_stat4.sample.  The nEq, nLt, and nDLt entries of sqlite_stat3

  104576. ** all contain just a single integer which is the same as the first

  104577. ** integer in the equivalent columns in sqlite_stat4.

  104578. */

  104579. #ifndef SQLITE_OMIT_ANALYZE

  104580. /* #include "sqliteInt.h" */

  104581. 

  104582. #if defined(SQLITE_ENABLE_STAT4)

  104583. # define IsStat4     1

  104584. # define IsStat3     0

  104585. #elif defined(SQLITE_ENABLE_STAT3)

  104586. # define IsStat4     0

  104587. # define IsStat3     1

  104588. #else

  104589. # define IsStat4     0

  104590. # define IsStat3     0

  104591. # undef SQLITE_STAT4_SAMPLES

  104592. # define SQLITE_STAT4_SAMPLES 1

  104593. #endif

  104594. #define IsStat34    (IsStat3+IsStat4)  /* 1 for STAT3 or STAT4. 0 otherwise */

  104595. 

  104596. /*

  104597. ** This routine generates code that opens the sqlite_statN tables.

  104598. ** The sqlite_stat1 table is always relevant.  sqlite_stat2 is now

  104599. ** obsolete.  sqlite_stat3 and sqlite_stat4 are only opened when

  104600. ** appropriate compile-time options are provided.

  104601. **

  104602. ** If the sqlite_statN tables do not previously exist, it is created.

  104603. **

  104604. ** Argument zWhere may be a pointer to a buffer containing a table name,

  104605. ** or it may be a NULL pointer. If it is not NULL, then all entries in

  104606. ** the sqlite_statN tables associated with the named table are deleted.

  104607. ** If zWhere==0, then code is generated to delete all stat table entries.

  104608. */

  104609. static void openStatTable(

  104610.   Parse *pParse,          /* Parsing context */

  104611.   int iDb,                /* The database we are looking in */

  104612.   int iStatCur,           /* Open the sqlite_stat1 table on this cursor */

  104613.   const char *zWhere,     /* Delete entries for this table or index */

  104614.   const char *zWhereType  /* Either "tbl" or "idx" */

  104615. ){

  104616.   static const struct {

  104617.     const char *zName;

  104618.     const char *zCols;

  104619.   } aTable[] = {

  104620.     { "sqlite_stat1", "tbl,idx,stat" },

  104621. #if defined(SQLITE_ENABLE_STAT4)

  104622.     { "sqlite_stat4", "tbl,idx,neq,nlt,ndlt,sample" },

  104623.     { "sqlite_stat3", 0 },

  104624. #elif defined(SQLITE_ENABLE_STAT3)

  104625.     { "sqlite_stat3", "tbl,idx,neq,nlt,ndlt,sample" },

  104626.     { "sqlite_stat4", 0 },

  104627. #else

  104628.     { "sqlite_stat3", 0 },

  104629.     { "sqlite_stat4", 0 },

  104630. #endif

  104631.   };

  104632.   int i;

  104633.   sqlite3 *db = pParse->db;

  104634.   Db *pDb;

  104635.   Vdbe *v = sqlite3GetVdbe(pParse);

  104636.   int aRoot[ArraySize(aTable)];

  104637.   u8 aCreateTbl[ArraySize(aTable)];

  104638. 

  104639.   if( v==0 ) return;

  104640.   assert( sqlite3BtreeHoldsAllMutexes(db) );

  104641.   assert( sqlite3VdbeDb(v)==db );

  104642.   pDb = &db->aDb[iDb];

  104643. 

  104644.   /* Create new statistic tables if they do not exist, or clear them

  104645.   ** if they do already exist.

  104646.   */

  104647.   for(i=0; i<ArraySize(aTable); i++){

  104648.     const char *zTab = aTable[i].zName;

  104649.     Table *pStat;

  104650.     if( (pStat = sqlite3FindTable(db, zTab, pDb->zDbSName))==0 ){

  104651.       if( aTable[i].zCols ){

  104652.         /* The sqlite_statN table does not exist. Create it. Note that a 

  104653.         ** side-effect of the CREATE TABLE statement is to leave the rootpage 

  104654.         ** of the new table in register pParse->regRoot. This is important 

  104655.         ** because the OpenWrite opcode below will be needing it. */

  104656.         sqlite3NestedParse(pParse,

  104657.             "CREATE TABLE %Q.%s(%s)", pDb->zDbSName, zTab, aTable[i].zCols

  104658.         );

  104659.         aRoot[i] = pParse->regRoot;

  104660.         aCreateTbl[i] = OPFLAG_P2ISREG;

  104661.       }

  104662.     }else{

  104663.       /* The table already exists. If zWhere is not NULL, delete all entries 

  104664.       ** associated with the table zWhere. If zWhere is NULL, delete the

  104665.       ** entire contents of the table. */

  104666.       aRoot[i] = pStat->tnum;

  104667.       aCreateTbl[i] = 0;

  104668.       sqlite3TableLock(pParse, iDb, aRoot[i], 1, zTab);

  104669.       if( zWhere ){

  104670.         sqlite3NestedParse(pParse,

  104671.            "DELETE FROM %Q.%s WHERE %s=%Q",

  104672.            pDb->zDbSName, zTab, zWhereType, zWhere

  104673.         );

  104674. #ifdef SQLITE_ENABLE_PREUPDATE_HOOK

  104675.       }else if( db->xPreUpdateCallback ){

  104676.         sqlite3NestedParse(pParse, "DELETE FROM %Q.%s", pDb->zDbSName, zTab);

  104677. #endif

  104678.       }else{

  104679.         /* The sqlite_stat[134] table already exists.  Delete all rows. */

  104680.         sqlite3VdbeAddOp2(v, OP_Clear, aRoot[i], iDb);

  104681.       }

  104682.     }

  104683.   }

  104684. 

  104685.   /* Open the sqlite_stat[134] tables for writing. */

  104686.   for(i=0; aTable[i].zCols; i++){

  104687.     assert( i<ArraySize(aTable) );

  104688.     sqlite3VdbeAddOp4Int(v, OP_OpenWrite, iStatCur+i, aRoot[i], iDb, 3);

  104689.     sqlite3VdbeChangeP5(v, aCreateTbl[i]);

  104690.     VdbeComment((v, aTable[i].zName));

  104691.   }

  104692. }

  104693. 

  104694. /*

  104695. ** Recommended number of samples for sqlite_stat4

  104696. */

  104697. #ifndef SQLITE_STAT4_SAMPLES

  104698. # define SQLITE_STAT4_SAMPLES 24

  104699. #endif

  104700. 

  104701. /*

  104702. ** Three SQL functions - stat_init(), stat_push(), and stat_get() -

  104703. ** share an instance of the following structure to hold their state

  104704. ** information.

  104705. */

  104706. typedef struct Stat4Accum Stat4Accum;

  104707. typedef struct Stat4Sample Stat4Sample;

  104708. struct Stat4Sample {

  104709.   tRowcnt *anEq;                  /* sqlite_stat4.nEq */

  104710.   tRowcnt *anDLt;                 /* sqlite_stat4.nDLt */

  104711. #ifdef SQLITE_ENABLE_STAT3_OR_STAT4

  104712.   tRowcnt *anLt;                  /* sqlite_stat4.nLt */

  104713.   union {

  104714.     i64 iRowid;                     /* Rowid in main table of the key */

  104715.     u8 *aRowid;                     /* Key for WITHOUT ROWID tables */

  104716.   } u;

  104717.   u32 nRowid;                     /* Sizeof aRowid[] */

  104718.   u8 isPSample;                   /* True if a periodic sample */

  104719.   int iCol;                       /* If !isPSample, the reason for inclusion */

  104720.   u32 iHash;                      /* Tiebreaker hash */

  104721. #endif

  104722. };                                                    

  104723. struct Stat4Accum {

  104724.   tRowcnt nRow;             /* Number of rows in the entire table */

  104725.   tRowcnt nPSample;         /* How often to do a periodic sample */

  104726.   int nCol;                 /* Number of columns in index + pk/rowid */

  104727.   int nKeyCol;              /* Number of index columns w/o the pk/rowid */

  104728.   int mxSample;             /* Maximum number of samples to accumulate */

  104729.   Stat4Sample current;      /* Current row as a Stat4Sample */

  104730.   u32 iPrn;                 /* Pseudo-random number used for sampling */

  104731.   Stat4Sample *aBest;       /* Array of nCol best samples */

  104732.   int iMin;                 /* Index in a[] of entry with minimum score */

  104733.   int nSample;              /* Current number of samples */

  104734.   int nMaxEqZero;           /* Max leading 0 in anEq[] for any a[] entry */

  104735.   int iGet;                 /* Index of current sample accessed by stat_get() */

  104736.   Stat4Sample *a;           /* Array of mxSample Stat4Sample objects */

  104737.   sqlite3 *db;              /* Database connection, for malloc() */

  104738. };

  104739. 

  104740. /* Reclaim memory used by a Stat4Sample

  104741. */

  104742. #ifdef SQLITE_ENABLE_STAT3_OR_STAT4

  104743. static void sampleClear(sqlite3 *db, Stat4Sample *p){

  104744.   assert( db!=0 );

  104745.   if( p->nRowid ){

  104746.     sqlite3DbFree(db, p->u.aRowid);

  104747.     p->nRowid = 0;

  104748.   }

  104749. }

  104750. #endif

  104751. 

  104752. /* Initialize the BLOB value of a ROWID

  104753. */

  104754. #ifdef SQLITE_ENABLE_STAT3_OR_STAT4

  104755. static void sampleSetRowid(sqlite3 *db, Stat4Sample *p, int n, const u8 *pData){

  104756.   assert( db!=0 );

  104757.   if( p->nRowid ) sqlite3DbFree(db, p->u.aRowid);

  104758.   p->u.aRowid = sqlite3DbMallocRawNN(db, n);

  104759.   if( p->u.aRowid ){

  104760.     p->nRowid = n;

  104761.     memcpy(p->u.aRowid, pData, n);

  104762.   }else{

  104763.     p->nRowid = 0;

  104764.   }

  104765. }

  104766. #endif

  104767. 

  104768. /* Initialize the INTEGER value of a ROWID.

  104769. */

  104770. #ifdef SQLITE_ENABLE_STAT3_OR_STAT4

  104771. static void sampleSetRowidInt64(sqlite3 *db, Stat4Sample *p, i64 iRowid){

  104772.   assert( db!=0 );

  104773.   if( p->nRowid ) sqlite3DbFree(db, p->u.aRowid);

  104774.   p->nRowid = 0;

  104775.   p->u.iRowid = iRowid;

  104776. }

  104777. #endif

  104778. 

  104779. 

  104780. /*

  104781. ** Copy the contents of object (*pFrom) into (*pTo).

  104782. */

  104783. #ifdef SQLITE_ENABLE_STAT3_OR_STAT4

  104784. static void sampleCopy(Stat4Accum *p, Stat4Sample *pTo, Stat4Sample *pFrom){

  104785.   pTo->isPSample = pFrom->isPSample;

  104786.   pTo->iCol = pFrom->iCol;

  104787.   pTo->iHash = pFrom->iHash;

  104788.   memcpy(pTo->anEq, pFrom->anEq, sizeof(tRowcnt)*p->nCol);

  104789.   memcpy(pTo->anLt, pFrom->anLt, sizeof(tRowcnt)*p->nCol);

  104790.   memcpy(pTo->anDLt, pFrom->anDLt, sizeof(tRowcnt)*p->nCol);

  104791.   if( pFrom->nRowid ){

  104792.     sampleSetRowid(p->db, pTo, pFrom->nRowid, pFrom->u.aRowid);

  104793.   }else{

  104794.     sampleSetRowidInt64(p->db, pTo, pFrom->u.iRowid);

  104795.   }

  104796. }

  104797. #endif

  104798. 

  104799. /*

  104800. ** Reclaim all memory of a Stat4Accum structure.

  104801. */

  104802. static void stat4Destructor(void *pOld){

  104803.   Stat4Accum *p = (Stat4Accum*)pOld;

  104804. #ifdef SQLITE_ENABLE_STAT3_OR_STAT4

  104805.   int i;

  104806.   for(i=0; i<p->nCol; i++) sampleClear(p->db, p->aBest+i);

  104807.   for(i=0; i<p->mxSample; i++) sampleClear(p->db, p->a+i);

  104808.   sampleClear(p->db, &p->current);

  104809. #endif

  104810.   sqlite3DbFree(p->db, p);

  104811. }

  104812. 

  104813. /*

  104814. ** Implementation of the stat_init(N,K,C) SQL function. The three parameters

  104815. ** are:

  104816. **     N:    The number of columns in the index including the rowid/pk (note 1)

  104817. **     K:    The number of columns in the index excluding the rowid/pk.

  104818. **     C:    The number of rows in the index (note 2)

  104819. **

  104820. ** Note 1:  In the special case of the covering index that implements a

  104821. ** WITHOUT ROWID table, N is the number of PRIMARY KEY columns, not the

  104822. ** total number of columns in the table.

  104823. **

  104824. ** Note 2:  C is only used for STAT3 and STAT4.

  104825. **

  104826. ** For indexes on ordinary rowid tables, N==K+1.  But for indexes on

  104827. ** WITHOUT ROWID tables, N=K+P where P is the number of columns in the

  104828. ** PRIMARY KEY of the table.  The covering index that implements the

  104829. ** original WITHOUT ROWID table as N==K as a special case.

  104830. **

  104831. ** This routine allocates the Stat4Accum object in heap memory. The return 

  104832. ** value is a pointer to the Stat4Accum object.  The datatype of the

  104833. ** return value is BLOB, but it is really just a pointer to the Stat4Accum

  104834. ** object.

  104835. */

  104836. static void statInit(

  104837.   sqlite3_context *context,

  104838.   int argc,

  104839.   sqlite3_value **argv

  104840. ){

  104841.   Stat4Accum *p;

  104842.   int nCol;                       /* Number of columns in index being sampled */

  104843.   int nKeyCol;                    /* Number of key columns */

  104844.   int nColUp;                     /* nCol rounded up for alignment */

  104845.   int n;                          /* Bytes of space to allocate */

  104846.   sqlite3 *db;                    /* Database connection */

  104847. #ifdef SQLITE_ENABLE_STAT3_OR_STAT4

  104848.   int mxSample = SQLITE_STAT4_SAMPLES;

  104849. #endif

  104850. 

  104851.   /* Decode the three function arguments */

  104852.   UNUSED_PARAMETER(argc);

  104853.   nCol = sqlite3_value_int(argv[0]);

  104854.   assert( nCol>0 );

  104855.   nColUp = sizeof(tRowcnt)<8 ? (nCol+1)&~1 : nCol;

  104856.   nKeyCol = sqlite3_value_int(argv[1]);

  104857.   assert( nKeyCol<=nCol );

  104858.   assert( nKeyCol>0 );

  104859. 

  104860.   /* Allocate the space required for the Stat4Accum object */

  104861.   n = sizeof(*p) 

  104862.     + sizeof(tRowcnt)*nColUp                  /* Stat4Accum.anEq */

  104863.     + sizeof(tRowcnt)*nColUp                  /* Stat4Accum.anDLt */

  104864. #ifdef SQLITE_ENABLE_STAT3_OR_STAT4

  104865.     + sizeof(tRowcnt)*nColUp                  /* Stat4Accum.anLt */

  104866.     + sizeof(Stat4Sample)*(nCol+mxSample)     /* Stat4Accum.aBest[], a[] */

  104867.     + sizeof(tRowcnt)*3*nColUp*(nCol+mxSample)

  104868. #endif

  104869.   ;

  104870.   db = sqlite3_context_db_handle(context);

  104871.   p = sqlite3DbMallocZero(db, n);

  104872.   if( p==0 ){

  104873.     sqlite3_result_error_nomem(context);

  104874.     return;

  104875.   }

  104876. 

  104877.   p->db = db;

  104878.   p->nRow = 0;

  104879.   p->nCol = nCol;

  104880.   p->nKeyCol = nKeyCol;

  104881.   p->current.anDLt = (tRowcnt*)&p[1];

  104882.   p->current.anEq = &p->current.anDLt[nColUp];

  104883. 

  104884. #ifdef SQLITE_ENABLE_STAT3_OR_STAT4

  104885.   {

  104886.     u8 *pSpace;                     /* Allocated space not yet assigned */

  104887.     int i;                          /* Used to iterate through p->aSample[] */

  104888. 

  104889.     p->iGet = -1;

  104890.     p->mxSample = mxSample;

  104891.     p->nPSample = (tRowcnt)(sqlite3_value_int64(argv[2])/(mxSample/3+1) + 1);

  104892.     p->current.anLt = &p->current.anEq[nColUp];

  104893.     p->iPrn = 0x689e962d*(u32)nCol ^ 0xd0944565*(u32)sqlite3_value_int(argv[2]);

  104894.   

  104895.     /* Set up the Stat4Accum.a[] and aBest[] arrays */

  104896.     p->a = (struct Stat4Sample*)&p->current.anLt[nColUp];

  104897.     p->aBest = &p->a[mxSample];

  104898.     pSpace = (u8*)(&p->a[mxSample+nCol]);

  104899.     for(i=0; i<(mxSample+nCol); i++){

  104900.       p->a[i].anEq = (tRowcnt *)pSpace; pSpace += (sizeof(tRowcnt) * nColUp);

  104901.       p->a[i].anLt = (tRowcnt *)pSpace; pSpace += (sizeof(tRowcnt) * nColUp);

  104902.       p->a[i].anDLt = (tRowcnt *)pSpace; pSpace += (sizeof(tRowcnt) * nColUp);

  104903.     }

  104904.     assert( (pSpace - (u8*)p)==n );

  104905.   

  104906.     for(i=0; i<nCol; i++){

  104907.       p->aBest[i].iCol = i;

  104908.     }

  104909.   }

  104910. #endif

  104911. 

  104912.   /* Return a pointer to the allocated object to the caller.  Note that

  104913.   ** only the pointer (the 2nd parameter) matters.  The size of the object

  104914.   ** (given by the 3rd parameter) is never used and can be any positive

  104915.   ** value. */

  104916.   sqlite3_result_blob(context, p, sizeof(*p), stat4Destructor);

  104917. }

  104918. static const FuncDef statInitFuncdef = {

  104919.   2+IsStat34,      /* nArg */

  104920.   SQLITE_UTF8,     /* funcFlags */

  104921.   0,               /* pUserData */

  104922.   0,               /* pNext */

  104923.   statInit,        /* xSFunc */

  104924.   0,               /* xFinalize */

  104925.   0, 0,            /* xValue, xInverse */

  104926.   "stat_init",     /* zName */

  104927.   {0}

  104928. };

  104929. 

  104930. #ifdef SQLITE_ENABLE_STAT4

  104931. /*

  104932. ** pNew and pOld are both candidate non-periodic samples selected for 

  104933. ** the same column (pNew->iCol==pOld->iCol). Ignoring this column and 

  104934. ** considering only any trailing columns and the sample hash value, this

  104935. ** function returns true if sample pNew is to be preferred over pOld.

  104936. ** In other words, if we assume that the cardinalities of the selected

  104937. ** column for pNew and pOld are equal, is pNew to be preferred over pOld.

  104938. **

  104939. ** This function assumes that for each argument sample, the contents of

  104940. ** the anEq[] array from pSample->anEq[pSample->iCol+1] onwards are valid. 

  104941. */

  104942. static int sampleIsBetterPost(

  104943.   Stat4Accum *pAccum, 

  104944.   Stat4Sample *pNew, 

  104945.   Stat4Sample *pOld

  104946. ){

  104947.   int nCol = pAccum->nCol;

  104948.   int i;

  104949.   assert( pNew->iCol==pOld->iCol );

  104950.   for(i=pNew->iCol+1; i<nCol; i++){

  104951.     if( pNew->anEq[i]>pOld->anEq[i] ) return 1;

  104952.     if( pNew->anEq[i]<pOld->anEq[i] ) return 0;

  104953.   }

  104954.   if( pNew->iHash>pOld->iHash ) return 1;

  104955.   return 0;

  104956. }

  104957. #endif

  104958. 

  104959. #ifdef SQLITE_ENABLE_STAT3_OR_STAT4

  104960. /*

  104961. ** Return true if pNew is to be preferred over pOld.

  104962. **

  104963. ** This function assumes that for each argument sample, the contents of

  104964. ** the anEq[] array from pSample->anEq[pSample->iCol] onwards are valid. 

  104965. */

  104966. static int sampleIsBetter(

  104967.   Stat4Accum *pAccum, 

  104968.   Stat4Sample *pNew, 

  104969.   Stat4Sample *pOld

  104970. ){

  104971.   tRowcnt nEqNew = pNew->anEq[pNew->iCol];

  104972.   tRowcnt nEqOld = pOld->anEq[pOld->iCol];

  104973. 

  104974.   assert( pOld->isPSample==0 && pNew->isPSample==0 );

  104975.   assert( IsStat4 || (pNew->iCol==0 && pOld->iCol==0) );

  104976. 

  104977.   if( (nEqNew>nEqOld) ) return 1;

  104978. #ifdef SQLITE_ENABLE_STAT4

  104979.   if( nEqNew==nEqOld ){

  104980.     if( pNew->iCol<pOld->iCol ) return 1;

  104981.     return (pNew->iCol==pOld->iCol && sampleIsBetterPost(pAccum, pNew, pOld));

  104982.   }

  104983.   return 0;

  104984. #else

  104985.   return (nEqNew==nEqOld && pNew->iHash>pOld->iHash);

  104986. #endif

  104987. }

  104988. 

  104989. /*

  104990. ** Copy the contents of sample *pNew into the p->a[] array. If necessary,

  104991. ** remove the least desirable sample from p->a[] to make room.

  104992. */

  104993. static void sampleInsert(Stat4Accum *p, Stat4Sample *pNew, int nEqZero){

  104994.   Stat4Sample *pSample = 0;

  104995.   int i;

  104996. 

  104997.   assert( IsStat4 || nEqZero==0 );

  104998. 

  104999. #ifdef SQLITE_ENABLE_STAT4

  105000.   /* Stat4Accum.nMaxEqZero is set to the maximum number of leading 0

  105001.   ** values in the anEq[] array of any sample in Stat4Accum.a[]. In

  105002.   ** other words, if nMaxEqZero is n, then it is guaranteed that there

  105003.   ** are no samples with Stat4Sample.anEq[m]==0 for (m>=n). */

  105004.   if( nEqZero>p->nMaxEqZero ){

  105005.     p->nMaxEqZero = nEqZero;

  105006.   }

  105007.   if( pNew->isPSample==0 ){

  105008.     Stat4Sample *pUpgrade = 0;

  105009.     assert( pNew->anEq[pNew->iCol]>0 );

  105010. 

  105011.     /* This sample is being added because the prefix that ends in column 

  105012.     ** iCol occurs many times in the table. However, if we have already

  105013.     ** added a sample that shares this prefix, there is no need to add

  105014.     ** this one. Instead, upgrade the priority of the highest priority

  105015.     ** existing sample that shares this prefix.  */

  105016.     for(i=p->nSample-1; i>=0; i--){

  105017.       Stat4Sample *pOld = &p->a[i];

  105018.       if( pOld->anEq[pNew->iCol]==0 ){

  105019.         if( pOld->isPSample ) return;

  105020.         assert( pOld->iCol>pNew->iCol );

  105021.         assert( sampleIsBetter(p, pNew, pOld) );

  105022.         if( pUpgrade==0 || sampleIsBetter(p, pOld, pUpgrade) ){

  105023.           pUpgrade = pOld;

  105024.         }

  105025.       }

  105026.     }

  105027.     if( pUpgrade ){

  105028.       pUpgrade->iCol = pNew->iCol;

  105029.       pUpgrade->anEq[pUpgrade->iCol] = pNew->anEq[pUpgrade->iCol];

  105030.       goto find_new_min;

  105031.     }

  105032.   }

  105033. #endif

  105034. 

  105035.   /* If necessary, remove sample iMin to make room for the new sample. */

  105036.   if( p->nSample>=p->mxSample ){

  105037.     Stat4Sample *pMin = &p->a[p->iMin];

  105038.     tRowcnt *anEq = pMin->anEq;

  105039.     tRowcnt *anLt = pMin->anLt;

  105040.     tRowcnt *anDLt = pMin->anDLt;

  105041.     sampleClear(p->db, pMin);

  105042.     memmove(pMin, &pMin[1], sizeof(p->a[0])*(p->nSample-p->iMin-1));

  105043.     pSample = &p->a[p->nSample-1];

  105044.     pSample->nRowid = 0;

  105045.     pSample->anEq = anEq;

  105046.     pSample->anDLt = anDLt;

  105047.     pSample->anLt = anLt;

  105048.     p->nSample = p->mxSample-1;

  105049.   }

  105050. 

  105051.   /* The "rows less-than" for the rowid column must be greater than that

  105052.   ** for the last sample in the p->a[] array. Otherwise, the samples would

  105053.   ** be out of order. */

  105054. #ifdef SQLITE_ENABLE_STAT4

  105055.   assert( p->nSample==0 

  105056.        || pNew->anLt[p->nCol-1] > p->a[p->nSample-1].anLt[p->nCol-1] );

  105057. #endif

  105058. 

  105059.   /* Insert the new sample */

  105060.   pSample = &p->a[p->nSample];

  105061.   sampleCopy(p, pSample, pNew);

  105062.   p->nSample++;

  105063. 

  105064.   /* Zero the first nEqZero entries in the anEq[] array. */

  105065.   memset(pSample->anEq, 0, sizeof(tRowcnt)*nEqZero);

  105066. 

  105067. #ifdef SQLITE_ENABLE_STAT4

  105068.  find_new_min:

  105069. #endif

  105070.   if( p->nSample>=p->mxSample ){

  105071.     int iMin = -1;

  105072.     for(i=0; i<p->mxSample; i++){

  105073.       if( p->a[i].isPSample ) continue;

  105074.       if( iMin<0 || sampleIsBetter(p, &p->a[iMin], &p->a[i]) ){

  105075.         iMin = i;

  105076.       }

  105077.     }

  105078.     assert( iMin>=0 );

  105079.     p->iMin = iMin;

  105080.   }

  105081. }

  105082. #endif /* SQLITE_ENABLE_STAT3_OR_STAT4 */

  105083. 

  105084. /*

  105085. ** Field iChng of the index being scanned has changed. So at this point

  105086. ** p->current contains a sample that reflects the previous row of the

  105087. ** index. The value of anEq[iChng] and subsequent anEq[] elements are

  105088. ** correct at this point.

  105089. */

  105090. static void samplePushPrevious(Stat4Accum *p, int iChng){

  105091. #ifdef SQLITE_ENABLE_STAT4

  105092.   int i;

  105093. 

  105094.   /* Check if any samples from the aBest[] array should be pushed

  105095.   ** into IndexSample.a[] at this point.  */

  105096.   for(i=(p->nCol-2); i>=iChng; i--){

  105097.     Stat4Sample *pBest = &p->aBest[i];

  105098.     pBest->anEq[i] = p->current.anEq[i];

  105099.     if( p->nSample<p->mxSample || sampleIsBetter(p, pBest, &p->a[p->iMin]) ){

  105100.       sampleInsert(p, pBest, i);

  105101.     }

  105102.   }

  105103. 

  105104.   /* Check that no sample contains an anEq[] entry with an index of

  105105.   ** p->nMaxEqZero or greater set to zero. */

  105106.   for(i=p->nSample-1; i>=0; i--){

  105107.     int j;

  105108.     for(j=p->nMaxEqZero; j<p->nCol; j++) assert( p->a[i].anEq[j]>0 );

  105109.   }

  105110. 

  105111.   /* Update the anEq[] fields of any samples already collected. */

  105112.   if( iChng<p->nMaxEqZero ){

  105113.     for(i=p->nSample-1; i>=0; i--){

  105114.       int j;

  105115.       for(j=iChng; j<p->nCol; j++){

  105116.         if( p->a[i].anEq[j]==0 ) p->a[i].anEq[j] = p->current.anEq[j];

  105117.       }

  105118.     }

  105119.     p->nMaxEqZero = iChng;

  105120.   }

  105121. #endif

  105122. 

  105123. #if defined(SQLITE_ENABLE_STAT3) && !defined(SQLITE_ENABLE_STAT4)

  105124.   if( iChng==0 ){

  105125.     tRowcnt nLt = p->current.anLt[0];

  105126.     tRowcnt nEq = p->current.anEq[0];

  105127. 

  105128.     /* Check if this is to be a periodic sample. If so, add it. */

  105129.     if( (nLt/p->nPSample)!=(nLt+nEq)/p->nPSample ){

  105130.       p->current.isPSample = 1;

  105131.       sampleInsert(p, &p->current, 0);

  105132.       p->current.isPSample = 0;

  105133.     }else 

  105134. 

  105135.     /* Or if it is a non-periodic sample. Add it in this case too. */

  105136.     if( p->nSample<p->mxSample 

  105137.      || sampleIsBetter(p, &p->current, &p->a[p->iMin]) 

  105138.     ){

  105139.       sampleInsert(p, &p->current, 0);

  105140.     }

  105141.   }

  105142. #endif

  105143. 

  105144. #ifndef SQLITE_ENABLE_STAT3_OR_STAT4

  105145.   UNUSED_PARAMETER( p );

  105146.   UNUSED_PARAMETER( iChng );

  105147. #endif

  105148. }

  105149. 

  105150. /*

  105151. ** Implementation of the stat_push SQL function:  stat_push(P,C,R)

  105152. ** Arguments:

  105153. **

  105154. **    P     Pointer to the Stat4Accum object created by stat_init()

  105155. **    C     Index of left-most column to differ from previous row

  105156. **    R     Rowid for the current row.  Might be a key record for

  105157. **          WITHOUT ROWID tables.

  105158. **

  105159. ** This SQL function always returns NULL.  It's purpose it to accumulate

  105160. ** statistical data and/or samples in the Stat4Accum object about the

  105161. ** index being analyzed.  The stat_get() SQL function will later be used to

  105162. ** extract relevant information for constructing the sqlite_statN tables.

  105163. **

  105164. ** The R parameter is only used for STAT3 and STAT4

  105165. */

  105166. static void statPush(

  105167.   sqlite3_context *context,

  105168.   int argc,

  105169.   sqlite3_value **argv

  105170. ){

  105171.   int i;

  105172. 

  105173.   /* The three function arguments */

  105174.   Stat4Accum *p = (Stat4Accum*)sqlite3_value_blob(argv[0]);

  105175.   int iChng = sqlite3_value_int(argv[1]);

  105176. 

  105177.   UNUSED_PARAMETER( argc );

  105178.   UNUSED_PARAMETER( context );

  105179.   assert( p->nCol>0 );

  105180.   assert( iChng<p->nCol );

  105181. 

  105182.   if( p->nRow==0 ){

  105183.     /* This is the first call to this function. Do initialization. */

  105184.     for(i=0; i<p->nCol; i++) p->current.anEq[i] = 1;

  105185.   }else{

  105186.     /* Second and subsequent calls get processed here */

  105187.     samplePushPrevious(p, iChng);

  105188. 

  105189.     /* Update anDLt[], anLt[] and anEq[] to reflect the values that apply

  105190.     ** to the current row of the index. */

  105191.     for(i=0; i<iChng; i++){

  105192.       p->current.anEq[i]++;

  105193.     }

  105194.     for(i=iChng; i<p->nCol; i++){

  105195.       p->current.anDLt[i]++;

  105196. #ifdef SQLITE_ENABLE_STAT3_OR_STAT4

  105197.       p->current.anLt[i] += p->current.anEq[i];

  105198. #endif

  105199.       p->current.anEq[i] = 1;

  105200.     }

  105201.   }

  105202.   p->nRow++;

  105203. #ifdef SQLITE_ENABLE_STAT3_OR_STAT4

  105204.   if( sqlite3_value_type(argv[2])==SQLITE_INTEGER ){

  105205.     sampleSetRowidInt64(p->db, &p->current, sqlite3_value_int64(argv[2]));

  105206.   }else{

  105207.     sampleSetRowid(p->db, &p->current, sqlite3_value_bytes(argv[2]),

  105208.                                        sqlite3_value_blob(argv[2]));

  105209.   }

  105210.   p->current.iHash = p->iPrn = p->iPrn*1103515245 + 12345;

  105211. #endif

  105212. 

  105213. #ifdef SQLITE_ENABLE_STAT4

  105214.   {

  105215.     tRowcnt nLt = p->current.anLt[p->nCol-1];

  105216. 

  105217.     /* Check if this is to be a periodic sample. If so, add it. */

  105218.     if( (nLt/p->nPSample)!=(nLt+1)/p->nPSample ){

  105219.       p->current.isPSample = 1;

  105220.       p->current.iCol = 0;

  105221.       sampleInsert(p, &p->current, p->nCol-1);

  105222.       p->current.isPSample = 0;

  105223.     }

  105224. 

  105225.     /* Update the aBest[] array. */

  105226.     for(i=0; i<(p->nCol-1); i++){

  105227.       p->current.iCol = i;

  105228.       if( i>=iChng || sampleIsBetterPost(p, &p->current, &p->aBest[i]) ){

  105229.         sampleCopy(p, &p->aBest[i], &p->current);

  105230.       }

  105231.     }

  105232.   }

  105233. #endif

  105234. }

  105235. static const FuncDef statPushFuncdef = {

  105236.   2+IsStat34,      /* nArg */

  105237.   SQLITE_UTF8,     /* funcFlags */

  105238.   0,               /* pUserData */

  105239.   0,               /* pNext */

  105240.   statPush,        /* xSFunc */

  105241.   0,               /* xFinalize */

  105242.   0, 0,            /* xValue, xInverse */

  105243.   "stat_push",     /* zName */

  105244.   {0}

  105245. };

  105246. 

  105247. #define STAT_GET_STAT1 0          /* "stat" column of stat1 table */

  105248. #define STAT_GET_ROWID 1          /* "rowid" column of stat[34] entry */

  105249. #define STAT_GET_NEQ   2          /* "neq" column of stat[34] entry */

  105250. #define STAT_GET_NLT   3          /* "nlt" column of stat[34] entry */

  105251. #define STAT_GET_NDLT  4          /* "ndlt" column of stat[34] entry */

  105252. 

  105253. /*

  105254. ** Implementation of the stat_get(P,J) SQL function.  This routine is

  105255. ** used to query statistical information that has been gathered into

  105256. ** the Stat4Accum object by prior calls to stat_push().  The P parameter

  105257. ** has type BLOB but it is really just a pointer to the Stat4Accum object.

  105258. ** The content to returned is determined by the parameter J

  105259. ** which is one of the STAT_GET_xxxx values defined above.

  105260. **

  105261. ** The stat_get(P,J) function is not available to generic SQL.  It is

  105262. ** inserted as part of a manually constructed bytecode program.  (See

  105263. ** the callStatGet() routine below.)  It is guaranteed that the P

  105264. ** parameter will always be a poiner to a Stat4Accum object, never a

  105265. ** NULL.

  105266. **

  105267. ** If neither STAT3 nor STAT4 are enabled, then J is always

  105268. ** STAT_GET_STAT1 and is hence omitted and this routine becomes

  105269. ** a one-parameter function, stat_get(P), that always returns the

  105270. ** stat1 table entry information.

  105271. */

  105272. static void statGet(

  105273.   sqlite3_context *context,

  105274.   int argc,

  105275.   sqlite3_value **argv

  105276. ){

  105277.   Stat4Accum *p = (Stat4Accum*)sqlite3_value_blob(argv[0]);

  105278. #ifdef SQLITE_ENABLE_STAT3_OR_STAT4

  105279.   /* STAT3 and STAT4 have a parameter on this routine. */

  105280.   int eCall = sqlite3_value_int(argv[1]);

  105281.   assert( argc==2 );

  105282.   assert( eCall==STAT_GET_STAT1 || eCall==STAT_GET_NEQ 

  105283.        || eCall==STAT_GET_ROWID || eCall==STAT_GET_NLT

  105284.        || eCall==STAT_GET_NDLT 

  105285.   );

  105286.   if( eCall==STAT_GET_STAT1 )

  105287. #else

  105288.   assert( argc==1 );

  105289. #endif

  105290.   {

  105291.     /* Return the value to store in the "stat" column of the sqlite_stat1

  105292.     ** table for this index.

  105293.     **

  105294.     ** The value is a string composed of a list of integers describing 

  105295.     ** the index. The first integer in the list is the total number of 

  105296.     ** entries in the index. There is one additional integer in the list 

  105297.     ** for each indexed column. This additional integer is an estimate of

  105298.     ** the number of rows matched by a stabbing query on the index using

  105299.     ** a key with the corresponding number of fields. In other words,

  105300.     ** if the index is on columns (a,b) and the sqlite_stat1 value is 

  105301.     ** "100 10 2", then SQLite estimates that:

  105302.     **

  105303.     **   * the index contains 100 rows,

  105304.     **   * "WHERE a=?" matches 10 rows, and

  105305.     **   * "WHERE a=? AND b=?" matches 2 rows.

  105306.     **

  105307.     ** If D is the count of distinct values and K is the total number of 

  105308.     ** rows, then each estimate is computed as:

  105309.     **

  105310.     **        I = (K+D-1)/D

  105311.     */

  105312.     char *z;

  105313.     int i;

  105314. 

  105315.     char *zRet = sqlite3MallocZero( (p->nKeyCol+1)*25 );

  105316.     if( zRet==0 ){

  105317.       sqlite3_result_error_nomem(context);

  105318.       return;

  105319.     }

  105320. 

  105321.     sqlite3_snprintf(24, zRet, "%llu", (u64)p->nRow);

  105322.     z = zRet + sqlite3Strlen30(zRet);

  105323.     for(i=0; i<p->nKeyCol; i++){

  105324.       u64 nDistinct = p->current.anDLt[i] + 1;

  105325.       u64 iVal = (p->nRow + nDistinct - 1) / nDistinct;

  105326.       sqlite3_snprintf(24, z, " %llu", iVal);

  105327.       z += sqlite3Strlen30(z);

  105328.       assert( p->current.anEq[i] );

  105329.     }

  105330.     assert( z[0]=='\0' && z>zRet );

  105331. 

  105332.     sqlite3_result_text(context, zRet, -1, sqlite3_free);

  105333.   }

  105334. #ifdef SQLITE_ENABLE_STAT3_OR_STAT4

  105335.   else if( eCall==STAT_GET_ROWID ){

  105336.     if( p->iGet<0 ){

  105337.       samplePushPrevious(p, 0);

  105338.       p->iGet = 0;

  105339.     }

  105340.     if( p->iGet<p->nSample ){

  105341.       Stat4Sample *pS = p->a + p->iGet;

  105342.       if( pS->nRowid==0 ){

  105343.         sqlite3_result_int64(context, pS->u.iRowid);

  105344.       }else{

  105345.         sqlite3_result_blob(context, pS->u.aRowid, pS->nRowid,

  105346.                             SQLITE_TRANSIENT);

  105347.       }

  105348.     }

  105349.   }else{

  105350.     tRowcnt *aCnt = 0;

  105351. 

  105352.     assert( p->iGet<p->nSample );

  105353.     switch( eCall ){

  105354.       case STAT_GET_NEQ:  aCnt = p->a[p->iGet].anEq; break;

  105355.       case STAT_GET_NLT:  aCnt = p->a[p->iGet].anLt; break;

  105356.       default: {

  105357.         aCnt = p->a[p->iGet].anDLt; 

  105358.         p->iGet++;

  105359.         break;

  105360.       }

  105361.     }

  105362. 

  105363.     if( IsStat3 ){

  105364.       sqlite3_result_int64(context, (i64)aCnt[0]);

  105365.     }else{

  105366.       char *zRet = sqlite3MallocZero(p->nCol * 25);

  105367.       if( zRet==0 ){

  105368.         sqlite3_result_error_nomem(context);

  105369.       }else{

  105370.         int i;

  105371.         char *z = zRet;

  105372.         for(i=0; i<p->nCol; i++){

  105373.           sqlite3_snprintf(24, z, "%llu ", (u64)aCnt[i]);

  105374.           z += sqlite3Strlen30(z);

  105375.         }

  105376.         assert( z[0]=='\0' && z>zRet );

  105377.         z[-1] = '\0';

  105378.         sqlite3_result_text(context, zRet, -1, sqlite3_free);

  105379.       }

  105380.     }

  105381.   }

  105382. #endif /* SQLITE_ENABLE_STAT3_OR_STAT4 */

  105383. #ifndef SQLITE_DEBUG

  105384.   UNUSED_PARAMETER( argc );

  105385. #endif

  105386. }

  105387. static const FuncDef statGetFuncdef = {

  105388.   1+IsStat34,      /* nArg */

  105389.   SQLITE_UTF8,     /* funcFlags */

  105390.   0,               /* pUserData */

  105391.   0,               /* pNext */

  105392.   statGet,         /* xSFunc */

  105393.   0,               /* xFinalize */

  105394.   0, 0,            /* xValue, xInverse */

  105395.   "stat_get",      /* zName */

  105396.   {0}

  105397. };

  105398. 

  105399. static void callStatGet(Vdbe *v, int regStat4, int iParam, int regOut){

  105400.   assert( regOut!=regStat4 && regOut!=regStat4+1 );

  105401. #ifdef SQLITE_ENABLE_STAT3_OR_STAT4

  105402.   sqlite3VdbeAddOp2(v, OP_Integer, iParam, regStat4+1);

  105403. #elif SQLITE_DEBUG

  105404.   assert( iParam==STAT_GET_STAT1 );

  105405. #else

  105406.   UNUSED_PARAMETER( iParam );

  105407. #endif

  105408.   sqlite3VdbeAddOp4(v, OP_Function0, 0, regStat4, regOut,

  105409.                     (char*)&statGetFuncdef, P4_FUNCDEF);

  105410.   sqlite3VdbeChangeP5(v, 1 + IsStat34);

  105411. }

  105412. 

  105413. /*

  105414. ** Generate code to do an analysis of all indices associated with

  105415. ** a single table.

  105416. */

  105417. static void analyzeOneTable(

  105418.   Parse *pParse,   /* Parser context */

  105419.   Table *pTab,     /* Table whose indices are to be analyzed */

  105420.   Index *pOnlyIdx, /* If not NULL, only analyze this one index */

  105421.   int iStatCur,    /* Index of VdbeCursor that writes the sqlite_stat1 table */

  105422.   int iMem,        /* Available memory locations begin here */

  105423.   int iTab         /* Next available cursor */

  105424. ){

  105425.   sqlite3 *db = pParse->db;    /* Database handle */

  105426.   Index *pIdx;                 /* An index to being analyzed */

  105427.   int iIdxCur;                 /* Cursor open on index being analyzed */

  105428.   int iTabCur;                 /* Table cursor */

  105429.   Vdbe *v;                     /* The virtual machine being built up */

  105430.   int i;                       /* Loop counter */

  105431.   int jZeroRows = -1;          /* Jump from here if number of rows is zero */

  105432.   int iDb;                     /* Index of database containing pTab */

  105433.   u8 needTableCnt = 1;         /* True to count the table */

  105434.   int regNewRowid = iMem++;    /* Rowid for the inserted record */

  105435.   int regStat4 = iMem++;       /* Register to hold Stat4Accum object */

  105436.   int regChng = iMem++;        /* Index of changed index field */

  105437. #ifdef SQLITE_ENABLE_STAT3_OR_STAT4

  105438.   int regRowid = iMem++;       /* Rowid argument passed to stat_push() */

  105439. #endif

  105440.   int regTemp = iMem++;        /* Temporary use register */

  105441.   int regTabname = iMem++;     /* Register containing table name */

  105442.   int regIdxname = iMem++;     /* Register containing index name */

  105443.   int regStat1 = iMem++;       /* Value for the stat column of sqlite_stat1 */

  105444.   int regPrev = iMem;          /* MUST BE LAST (see below) */

  105445. #ifdef SQLITE_ENABLE_PREUPDATE_HOOK

  105446.   Table *pStat1 = 0; 

  105447. #endif

  105448. 

  105449.   pParse->nMem = MAX(pParse->nMem, iMem);

  105450.   v = sqlite3GetVdbe(pParse);

  105451.   if( v==0 || NEVER(pTab==0) ){

  105452.     return;

  105453.   }

  105454.   if( pTab->tnum==0 ){

  105455.     /* Do not gather statistics on views or virtual tables */

  105456.     return;

  105457.   }

  105458.   if( sqlite3_strlike("sqlite\\_%", pTab->zName, '\\')==0 ){

  105459.     /* Do not gather statistics on system tables */

  105460.     return;

  105461.   }

  105462.   assert( sqlite3BtreeHoldsAllMutexes(db) );

  105463.   iDb = sqlite3SchemaToIndex(db, pTab->pSchema);

  105464.   assert( iDb>=0 );

  105465.   assert( sqlite3SchemaMutexHeld(db, iDb, 0) );

  105466. #ifndef SQLITE_OMIT_AUTHORIZATION

  105467.   if( sqlite3AuthCheck(pParse, SQLITE_ANALYZE, pTab->zName, 0,

  105468.       db->aDb[iDb].zDbSName ) ){

  105469.     return;

  105470.   }

  105471. #endif

  105472. 

  105473. #ifdef SQLITE_ENABLE_PREUPDATE_HOOK

  105474.   if( db->xPreUpdateCallback ){

  105475.     pStat1 = (Table*)sqlite3DbMallocZero(db, sizeof(Table) + 13);

  105476.     if( pStat1==0 ) return;

  105477.     pStat1->zName = (char*)&pStat1[1];

  105478.     memcpy(pStat1->zName, "sqlite_stat1", 13);

  105479.     pStat1->nCol = 3;

  105480.     pStat1->iPKey = -1;

  105481.     sqlite3VdbeAddOp4(pParse->pVdbe, OP_Noop, 0, 0, 0,(char*)pStat1,P4_DYNBLOB);

  105482.   }

  105483. #endif

  105484. 

  105485.   /* Establish a read-lock on the table at the shared-cache level. 

  105486.   ** Open a read-only cursor on the table. Also allocate a cursor number

  105487.   ** to use for scanning indexes (iIdxCur). No index cursor is opened at

  105488.   ** this time though.  */

  105489.   sqlite3TableLock(pParse, iDb, pTab->tnum, 0, pTab->zName);

  105490.   iTabCur = iTab++;

  105491.   iIdxCur = iTab++;

  105492.   pParse->nTab = MAX(pParse->nTab, iTab);

  105493.   sqlite3OpenTable(pParse, iTabCur, iDb, pTab, OP_OpenRead);

  105494.   sqlite3VdbeLoadString(v, regTabname, pTab->zName);

  105495. 

  105496.   for(pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext){

  105497.     int nCol;                     /* Number of columns in pIdx. "N" */

  105498.     int addrRewind;               /* Address of "OP_Rewind iIdxCur" */

  105499.     int addrNextRow;              /* Address of "next_row:" */

  105500.     const char *zIdxName;         /* Name of the index */

  105501.     int nColTest;                 /* Number of columns to test for changes */

  105502. 

  105503.     if( pOnlyIdx && pOnlyIdx!=pIdx ) continue;

  105504.     if( pIdx->pPartIdxWhere==0 ) needTableCnt = 0;

  105505.     if( !HasRowid(pTab) && IsPrimaryKeyIndex(pIdx) ){

  105506.       nCol = pIdx->nKeyCol;

  105507.       zIdxName = pTab->zName;

  105508.       nColTest = nCol - 1;

  105509.     }else{

  105510.       nCol = pIdx->nColumn;

  105511.       zIdxName = pIdx->zName;

  105512.       nColTest = pIdx->uniqNotNull ? pIdx->nKeyCol-1 : nCol-1;

  105513.     }

  105514. 

  105515.     /* Populate the register containing the index name. */

  105516.     sqlite3VdbeLoadString(v, regIdxname, zIdxName);

  105517.     VdbeComment((v, "Analysis for %s.%s", pTab->zName, zIdxName));

  105518. 

  105519.     /*

  105520.     ** Pseudo-code for loop that calls stat_push():

  105521.     **

  105522.     **   Rewind csr

  105523.     **   if eof(csr) goto end_of_scan;

  105524.     **   regChng = 0

  105525.     **   goto chng_addr_0;

  105526.     **

  105527.     **  next_row:

  105528.     **   regChng = 0

  105529.     **   if( idx(0) != regPrev(0) ) goto chng_addr_0

  105530.     **   regChng = 1

  105531.     **   if( idx(1) != regPrev(1) ) goto chng_addr_1

  105532.     **   ...

  105533.     **   regChng = N

  105534.     **   goto chng_addr_N

  105535.     **

  105536.     **  chng_addr_0:

  105537.     **   regPrev(0) = idx(0)

  105538.     **  chng_addr_1:

  105539.     **   regPrev(1) = idx(1)

  105540.     **  ...

  105541.     **

  105542.     **  endDistinctTest:

  105543.     **   regRowid = idx(rowid)

  105544.     **   stat_push(P, regChng, regRowid)

  105545.     **   Next csr

  105546.     **   if !eof(csr) goto next_row;

  105547.     **

  105548.     **  end_of_scan:

  105549.     */

  105550. 

  105551.     /* Make sure there are enough memory cells allocated to accommodate 

  105552.     ** the regPrev array and a trailing rowid (the rowid slot is required

  105553.     ** when building a record to insert into the sample column of 

  105554.     ** the sqlite_stat4 table.  */

  105555.     pParse->nMem = MAX(pParse->nMem, regPrev+nColTest);

  105556. 

  105557.     /* Open a read-only cursor on the index being analyzed. */

  105558.     assert( iDb==sqlite3SchemaToIndex(db, pIdx->pSchema) );

  105559.     sqlite3VdbeAddOp3(v, OP_OpenRead, iIdxCur, pIdx->tnum, iDb);

  105560.     sqlite3VdbeSetP4KeyInfo(pParse, pIdx);

  105561.     VdbeComment((v, "%s", pIdx->zName));

  105562. 

  105563.     /* Invoke the stat_init() function. The arguments are:

  105564.     ** 

  105565.     **    (1) the number of columns in the index including the rowid

  105566.     **        (or for a WITHOUT ROWID table, the number of PK columns),

  105567.     **    (2) the number of columns in the key without the rowid/pk

  105568.     **    (3) the number of rows in the index,

  105569.     **

  105570.     **

  105571.     ** The third argument is only used for STAT3 and STAT4

  105572.     */

  105573. #ifdef SQLITE_ENABLE_STAT3_OR_STAT4

  105574.     sqlite3VdbeAddOp2(v, OP_Count, iIdxCur, regStat4+3);

  105575. #endif

  105576.     sqlite3VdbeAddOp2(v, OP_Integer, nCol, regStat4+1);

  105577.     sqlite3VdbeAddOp2(v, OP_Integer, pIdx->nKeyCol, regStat4+2);

  105578.     sqlite3VdbeAddOp4(v, OP_Function0, 0, regStat4+1, regStat4,

  105579.                      (char*)&statInitFuncdef, P4_FUNCDEF);

  105580.     sqlite3VdbeChangeP5(v, 2+IsStat34);

  105581. 

  105582.     /* Implementation of the following:

  105583.     **

  105584.     **   Rewind csr

  105585.     **   if eof(csr) goto end_of_scan;

  105586.     **   regChng = 0

  105587.     **   goto next_push_0;

  105588.     **

  105589.     */

  105590.     addrRewind = sqlite3VdbeAddOp1(v, OP_Rewind, iIdxCur);

  105591.     VdbeCoverage(v);

  105592.     sqlite3VdbeAddOp2(v, OP_Integer, 0, regChng);

  105593.     addrNextRow = sqlite3VdbeCurrentAddr(v);

  105594. 

  105595.     if( nColTest>0 ){

  105596.       int endDistinctTest = sqlite3VdbeMakeLabel(pParse);

  105597.       int *aGotoChng;               /* Array of jump instruction addresses */

  105598.       aGotoChng = sqlite3DbMallocRawNN(db, sizeof(int)*nColTest);

  105599.       if( aGotoChng==0 ) continue;

  105600. 

  105601.       /*

  105602.       **  next_row:

  105603.       **   regChng = 0

  105604.       **   if( idx(0) != regPrev(0) ) goto chng_addr_0

  105605.       **   regChng = 1

  105606.       **   if( idx(1) != regPrev(1) ) goto chng_addr_1

  105607.       **   ...

  105608.       **   regChng = N

  105609.       **   goto endDistinctTest

  105610.       */

  105611.       sqlite3VdbeAddOp0(v, OP_Goto);

  105612.       addrNextRow = sqlite3VdbeCurrentAddr(v);

  105613.       if( nColTest==1 && pIdx->nKeyCol==1 && IsUniqueIndex(pIdx) ){

  105614.         /* For a single-column UNIQUE index, once we have found a non-NULL

  105615.         ** row, we know that all the rest will be distinct, so skip 

  105616.         ** subsequent distinctness tests. */

  105617.         sqlite3VdbeAddOp2(v, OP_NotNull, regPrev, endDistinctTest);

  105618.         VdbeCoverage(v);

  105619.       }

  105620.       for(i=0; i<nColTest; i++){

  105621.         char *pColl = (char*)sqlite3LocateCollSeq(pParse, pIdx->azColl[i]);

  105622.         sqlite3VdbeAddOp2(v, OP_Integer, i, regChng);

  105623.         sqlite3VdbeAddOp3(v, OP_Column, iIdxCur, i, regTemp);

  105624.         aGotoChng[i] = 

  105625.         sqlite3VdbeAddOp4(v, OP_Ne, regTemp, 0, regPrev+i, pColl, P4_COLLSEQ);

  105626.         sqlite3VdbeChangeP5(v, SQLITE_NULLEQ);

  105627.         VdbeCoverage(v);

  105628.       }

  105629.       sqlite3VdbeAddOp2(v, OP_Integer, nColTest, regChng);

  105630.       sqlite3VdbeGoto(v, endDistinctTest);

  105631.   

  105632.   

  105633.       /*

  105634.       **  chng_addr_0:

  105635.       **   regPrev(0) = idx(0)

  105636.       **  chng_addr_1:

  105637.       **   regPrev(1) = idx(1)

  105638.       **  ...

  105639.       */

  105640.       sqlite3VdbeJumpHere(v, addrNextRow-1);

  105641.       for(i=0; i<nColTest; i++){

  105642.         sqlite3VdbeJumpHere(v, aGotoChng[i]);

  105643.         sqlite3VdbeAddOp3(v, OP_Column, iIdxCur, i, regPrev+i);

  105644.       }

  105645.       sqlite3VdbeResolveLabel(v, endDistinctTest);

  105646.       sqlite3DbFree(db, aGotoChng);

  105647.     }

  105648.   

  105649.     /*

  105650.     **  chng_addr_N:

  105651.     **   regRowid = idx(rowid)            // STAT34 only

  105652.     **   stat_push(P, regChng, regRowid)  // 3rd parameter STAT34 only

  105653.     **   Next csr

  105654.     **   if !eof(csr) goto next_row;

  105655.     */

  105656. #ifdef SQLITE_ENABLE_STAT3_OR_STAT4

  105657.     assert( regRowid==(regStat4+2) );

  105658.     if( HasRowid(pTab) ){

  105659.       sqlite3VdbeAddOp2(v, OP_IdxRowid, iIdxCur, regRowid);

  105660.     }else{

  105661.       Index *pPk = sqlite3PrimaryKeyIndex(pIdx->pTable);

  105662.       int j, k, regKey;

  105663.       regKey = sqlite3GetTempRange(pParse, pPk->nKeyCol);

  105664.       for(j=0; j<pPk->nKeyCol; j++){

  105665.         k = sqlite3ColumnOfIndex(pIdx, pPk->aiColumn[j]);

  105666.         assert( k>=0 && k<pIdx->nColumn );

  105667.         sqlite3VdbeAddOp3(v, OP_Column, iIdxCur, k, regKey+j);

  105668.         VdbeComment((v, "%s", pTab->aCol[pPk->aiColumn[j]].zName));

  105669.       }

  105670.       sqlite3VdbeAddOp3(v, OP_MakeRecord, regKey, pPk->nKeyCol, regRowid);

  105671.       sqlite3ReleaseTempRange(pParse, regKey, pPk->nKeyCol);

  105672.     }

  105673. #endif

  105674.     assert( regChng==(regStat4+1) );

  105675.     sqlite3VdbeAddOp4(v, OP_Function0, 1, regStat4, regTemp,

  105676.                      (char*)&statPushFuncdef, P4_FUNCDEF);

  105677.     sqlite3VdbeChangeP5(v, 2+IsStat34);

  105678.     sqlite3VdbeAddOp2(v, OP_Next, iIdxCur, addrNextRow); VdbeCoverage(v);

  105679. 

  105680.     /* Add the entry to the stat1 table. */

  105681.     callStatGet(v, regStat4, STAT_GET_STAT1, regStat1);

  105682.     assert( "BBB"[0]==SQLITE_AFF_TEXT );

  105683.     sqlite3VdbeAddOp4(v, OP_MakeRecord, regTabname, 3, regTemp, "BBB", 0);

  105684.     sqlite3VdbeAddOp2(v, OP_NewRowid, iStatCur, regNewRowid);

  105685.     sqlite3VdbeAddOp3(v, OP_Insert, iStatCur, regTemp, regNewRowid);

  105686. #ifdef SQLITE_ENABLE_PREUPDATE_HOOK

  105687.     sqlite3VdbeChangeP4(v, -1, (char*)pStat1, P4_TABLE);

  105688. #endif

  105689.     sqlite3VdbeChangeP5(v, OPFLAG_APPEND);

  105690. 

  105691.     /* Add the entries to the stat3 or stat4 table. */

  105692. #ifdef SQLITE_ENABLE_STAT3_OR_STAT4

  105693.     {

  105694.       int regEq = regStat1;

  105695.       int regLt = regStat1+1;

  105696.       int regDLt = regStat1+2;

  105697.       int regSample = regStat1+3;

  105698.       int regCol = regStat1+4;

  105699.       int regSampleRowid = regCol + nCol;

  105700.       int addrNext;

  105701.       int addrIsNull;

  105702.       u8 seekOp = HasRowid(pTab) ? OP_NotExists : OP_NotFound;

  105703. 

  105704.       pParse->nMem = MAX(pParse->nMem, regCol+nCol);

  105705. 

  105706.       addrNext = sqlite3VdbeCurrentAddr(v);

  105707.       callStatGet(v, regStat4, STAT_GET_ROWID, regSampleRowid);

  105708.       addrIsNull = sqlite3VdbeAddOp1(v, OP_IsNull, regSampleRowid);

  105709.       VdbeCoverage(v);

  105710.       callStatGet(v, regStat4, STAT_GET_NEQ, regEq);

  105711.       callStatGet(v, regStat4, STAT_GET_NLT, regLt);

  105712.       callStatGet(v, regStat4, STAT_GET_NDLT, regDLt);

  105713.       sqlite3VdbeAddOp4Int(v, seekOp, iTabCur, addrNext, regSampleRowid, 0);

  105714.       VdbeCoverage(v);

  105715. #ifdef SQLITE_ENABLE_STAT3

  105716.       sqlite3ExprCodeLoadIndexColumn(pParse, pIdx, iTabCur, 0, regSample);

  105717. #else

  105718.       for(i=0; i<nCol; i++){

  105719.         sqlite3ExprCodeLoadIndexColumn(pParse, pIdx, iTabCur, i, regCol+i);

  105720.       }

  105721.       sqlite3VdbeAddOp3(v, OP_MakeRecord, regCol, nCol, regSample);

  105722. #endif

  105723.       sqlite3VdbeAddOp3(v, OP_MakeRecord, regTabname, 6, regTemp);

  105724.       sqlite3VdbeAddOp2(v, OP_NewRowid, iStatCur+1, regNewRowid);

  105725.       sqlite3VdbeAddOp3(v, OP_Insert, iStatCur+1, regTemp, regNewRowid);

  105726.       sqlite3VdbeAddOp2(v, OP_Goto, 1, addrNext); /* P1==1 for end-of-loop */

  105727.       sqlite3VdbeJumpHere(v, addrIsNull);

  105728.     }

  105729. #endif /* SQLITE_ENABLE_STAT3_OR_STAT4 */

  105730. 

  105731.     /* End of analysis */

  105732.     sqlite3VdbeJumpHere(v, addrRewind);

  105733.   }

  105734. 

  105735. 

  105736.   /* Create a single sqlite_stat1 entry containing NULL as the index

  105737.   ** name and the row count as the content.

  105738.   */

  105739.   if( pOnlyIdx==0 && needTableCnt ){

  105740.     VdbeComment((v, "%s", pTab->zName));

  105741.     sqlite3VdbeAddOp2(v, OP_Count, iTabCur, regStat1);

  105742.     jZeroRows = sqlite3VdbeAddOp1(v, OP_IfNot, regStat1); VdbeCoverage(v);

  105743.     sqlite3VdbeAddOp2(v, OP_Null, 0, regIdxname);

  105744.     assert( "BBB"[0]==SQLITE_AFF_TEXT );

  105745.     sqlite3VdbeAddOp4(v, OP_MakeRecord, regTabname, 3, regTemp, "BBB", 0);

  105746.     sqlite3VdbeAddOp2(v, OP_NewRowid, iStatCur, regNewRowid);

  105747.     sqlite3VdbeAddOp3(v, OP_Insert, iStatCur, regTemp, regNewRowid);

  105748.     sqlite3VdbeChangeP5(v, OPFLAG_APPEND);

  105749. #ifdef SQLITE_ENABLE_PREUPDATE_HOOK

  105750.     sqlite3VdbeChangeP4(v, -1, (char*)pStat1, P4_TABLE);

  105751. #endif

  105752.     sqlite3VdbeJumpHere(v, jZeroRows);

  105753.   }

  105754. }

  105755. 

  105756. 

  105757. /*

  105758. ** Generate code that will cause the most recent index analysis to

  105759. ** be loaded into internal hash tables where is can be used.

  105760. */

  105761. static void loadAnalysis(Parse *pParse, int iDb){

  105762.   Vdbe *v = sqlite3GetVdbe(pParse);

  105763.   if( v ){

  105764.     sqlite3VdbeAddOp1(v, OP_LoadAnalysis, iDb);

  105765.   }

  105766. }

  105767. 

  105768. /*

  105769. ** Generate code that will do an analysis of an entire database

  105770. */

  105771. static void analyzeDatabase(Parse *pParse, int iDb){

  105772.   sqlite3 *db = pParse->db;

  105773.   Schema *pSchema = db->aDb[iDb].pSchema;    /* Schema of database iDb */

  105774.   HashElem *k;

  105775.   int iStatCur;

  105776.   int iMem;

  105777.   int iTab;

  105778. 

  105779.   sqlite3BeginWriteOperation(pParse, 0, iDb);

  105780.   iStatCur = pParse->nTab;

  105781.   pParse->nTab += 3;

  105782.   openStatTable(pParse, iDb, iStatCur, 0, 0);

  105783.   iMem = pParse->nMem+1;

  105784.   iTab = pParse->nTab;

  105785.   assert( sqlite3SchemaMutexHeld(db, iDb, 0) );

  105786.   for(k=sqliteHashFirst(&pSchema->tblHash); k; k=sqliteHashNext(k)){

  105787.     Table *pTab = (Table*)sqliteHashData(k);

  105788.     analyzeOneTable(pParse, pTab, 0, iStatCur, iMem, iTab);

  105789.   }

  105790.   loadAnalysis(pParse, iDb);

  105791. }

  105792. 

  105793. /*

  105794. ** Generate code that will do an analysis of a single table in

  105795. ** a database.  If pOnlyIdx is not NULL then it is a single index

  105796. ** in pTab that should be analyzed.

  105797. */

  105798. static void analyzeTable(Parse *pParse, Table *pTab, Index *pOnlyIdx){

  105799.   int iDb;

  105800.   int iStatCur;

  105801. 

  105802.   assert( pTab!=0 );

  105803.   assert( sqlite3BtreeHoldsAllMutexes(pParse->db) );

  105804.   iDb = sqlite3SchemaToIndex(pParse->db, pTab->pSchema);

  105805.   sqlite3BeginWriteOperation(pParse, 0, iDb);

  105806.   iStatCur = pParse->nTab;

  105807.   pParse->nTab += 3;

  105808.   if( pOnlyIdx ){

  105809.     openStatTable(pParse, iDb, iStatCur, pOnlyIdx->zName, "idx");

  105810.   }else{

  105811.     openStatTable(pParse, iDb, iStatCur, pTab->zName, "tbl");

  105812.   }

  105813.   analyzeOneTable(pParse, pTab, pOnlyIdx, iStatCur,pParse->nMem+1,pParse->nTab);

  105814.   loadAnalysis(pParse, iDb);

  105815. }

  105816. 

  105817. /*

  105818. ** Generate code for the ANALYZE command.  The parser calls this routine

  105819. ** when it recognizes an ANALYZE command.

  105820. **

  105821. **        ANALYZE                            -- 1

  105822. **        ANALYZE  <database>                -- 2

  105823. **        ANALYZE  ?<database>.?<tablename>  -- 3

  105824. **

  105825. ** Form 1 causes all indices in all attached databases to be analyzed.

  105826. ** Form 2 analyzes all indices the single database named.

  105827. ** Form 3 analyzes all indices associated with the named table.

  105828. */

  105829. SQLITE_PRIVATE void sqlite3Analyze(Parse *pParse, Token *pName1, Token *pName2){

  105830.   sqlite3 *db = pParse->db;

  105831.   int iDb;

  105832.   int i;

  105833.   char *z, *zDb;

  105834.   Table *pTab;

  105835.   Index *pIdx;

  105836.   Token *pTableName;

  105837.   Vdbe *v;

  105838. 

  105839.   /* Read the database schema. If an error occurs, leave an error message

  105840.   ** and code in pParse and return NULL. */

  105841.   assert( sqlite3BtreeHoldsAllMutexes(pParse->db) );

  105842.   if( SQLITE_OK!=sqlite3ReadSchema(pParse) ){

  105843.     return;

  105844.   }

  105845. 

  105846.   assert( pName2!=0 || pName1==0 );

  105847.   if( pName1==0 ){

  105848.     /* Form 1:  Analyze everything */

  105849.     for(i=0; i<db->nDb; i++){

  105850.       if( i==1 ) continue;  /* Do not analyze the TEMP database */

  105851.       analyzeDatabase(pParse, i);

  105852.     }

  105853.   }else if( pName2->n==0 && (iDb = sqlite3FindDb(db, pName1))>=0 ){

  105854.     /* Analyze the schema named as the argument */

  105855.     analyzeDatabase(pParse, iDb);

  105856.   }else{

  105857.     /* Form 3: Analyze the table or index named as an argument */

  105858.     iDb = sqlite3TwoPartName(pParse, pName1, pName2, &pTableName);

  105859.     if( iDb>=0 ){

  105860.       zDb = pName2->n ? db->aDb[iDb].zDbSName : 0;

  105861.       z = sqlite3NameFromToken(db, pTableName);

  105862.       if( z ){

  105863.         if( (pIdx = sqlite3FindIndex(db, z, zDb))!=0 ){

  105864.           analyzeTable(pParse, pIdx->pTable, pIdx);

  105865.         }else if( (pTab = sqlite3LocateTable(pParse, 0, z, zDb))!=0 ){

  105866.           analyzeTable(pParse, pTab, 0);

  105867.         }

  105868.         sqlite3DbFree(db, z);

  105869.       }

  105870.     }

  105871.   }

  105872.   if( db->nSqlExec==0 && (v = sqlite3GetVdbe(pParse))!=0 ){

  105873.     sqlite3VdbeAddOp0(v, OP_Expire);

  105874.   }

  105875. }

  105876. 

  105877. /*

  105878. ** Used to pass information from the analyzer reader through to the

  105879. ** callback routine.

  105880. */

  105881. typedef struct analysisInfo analysisInfo;

  105882. struct analysisInfo {

  105883.   sqlite3 *db;

  105884.   const char *zDatabase;

  105885. };

  105886. 

  105887. /*

  105888. ** The first argument points to a nul-terminated string containing a

  105889. ** list of space separated integers. Read the first nOut of these into

  105890. ** the array aOut[].

  105891. */

  105892. static void decodeIntArray(

  105893.   char *zIntArray,       /* String containing int array to decode */

  105894.   int nOut,              /* Number of slots in aOut[] */

  105895.   tRowcnt *aOut,         /* Store integers here */

  105896.   LogEst *aLog,          /* Or, if aOut==0, here */

  105897.   Index *pIndex          /* Handle extra flags for this index, if not NULL */

  105898. ){

  105899.   char *z = zIntArray;

  105900.   int c;

  105901.   int i;

  105902.   tRowcnt v;

  105903. 

  105904. #ifdef SQLITE_ENABLE_STAT3_OR_STAT4

  105905.   if( z==0 ) z = "";

  105906. #else

  105907.   assert( z!=0 );

  105908. #endif

  105909.   for(i=0; *z && i<nOut; i++){

  105910.     v = 0;

  105911.     while( (c=z[0])>='0' && c<='9' ){

  105912.       v = v*10 + c - '0';

  105913.       z++;

  105914.     }

  105915. #ifdef SQLITE_ENABLE_STAT3_OR_STAT4

  105916.     if( aOut ) aOut[i] = v;

  105917.     if( aLog ) aLog[i] = sqlite3LogEst(v);

  105918. #else

  105919.     assert( aOut==0 );

  105920.     UNUSED_PARAMETER(aOut);

  105921.     assert( aLog!=0 );

  105922.     aLog[i] = sqlite3LogEst(v);

  105923. #endif

  105924.     if( *z==' ' ) z++;

  105925.   }

  105926. #ifndef SQLITE_ENABLE_STAT3_OR_STAT4

  105927.   assert( pIndex!=0 ); {

  105928. #else

  105929.   if( pIndex ){

  105930. #endif

  105931.     pIndex->bUnordered = 0;

  105932.     pIndex->noSkipScan = 0;

  105933.     while( z[0] ){

  105934.       if( sqlite3_strglob("unordered*", z)==0 ){

  105935.         pIndex->bUnordered = 1;

  105936.       }else if( sqlite3_strglob("sz=[0-9]*", z)==0 ){

  105937.         pIndex->szIdxRow = sqlite3LogEst(sqlite3Atoi(z+3));

  105938.       }else if( sqlite3_strglob("noskipscan*", z)==0 ){

  105939.         pIndex->noSkipScan = 1;

  105940.       }

  105941. #ifdef SQLITE_ENABLE_COSTMULT

  105942.       else if( sqlite3_strglob("costmult=[0-9]*",z)==0 ){

  105943.         pIndex->pTable->costMult = sqlite3LogEst(sqlite3Atoi(z+9));

  105944.       }

  105945. #endif

  105946.       while( z[0]!=0 && z[0]!=' ' ) z++;

  105947.       while( z[0]==' ' ) z++;

  105948.     }

  105949.   }

  105950. }

  105951. 

  105952. /*

  105953. ** This callback is invoked once for each index when reading the

  105954. ** sqlite_stat1 table.  

  105955. **

  105956. **     argv[0] = name of the table

  105957. **     argv[1] = name of the index (might be NULL)

  105958. **     argv[2] = results of analysis - on integer for each column

  105959. **

  105960. ** Entries for which argv[1]==NULL simply record the number of rows in

  105961. ** the table.

  105962. */

  105963. static int analysisLoader(void *pData, int argc, char **argv, char **NotUsed){

  105964.   analysisInfo *pInfo = (analysisInfo*)pData;

  105965.   Index *pIndex;

  105966.   Table *pTable;

  105967.   const char *z;

  105968. 

  105969.   assert( argc==3 );

  105970.   UNUSED_PARAMETER2(NotUsed, argc);

  105971. 

  105972.   if( argv==0 || argv[0]==0 || argv[2]==0 ){

  105973.     return 0;

  105974.   }

  105975.   pTable = sqlite3FindTable(pInfo->db, argv[0], pInfo->zDatabase);

  105976.   if( pTable==0 ){

  105977.     return 0;

  105978.   }

  105979.   if( argv[1]==0 ){

  105980.     pIndex = 0;

  105981.   }else if( sqlite3_stricmp(argv[0],argv[1])==0 ){

  105982.     pIndex = sqlite3PrimaryKeyIndex(pTable);

  105983.   }else{

  105984.     pIndex = sqlite3FindIndex(pInfo->db, argv[1], pInfo->zDatabase);

  105985.   }

  105986.   z = argv[2];

  105987. 

  105988.   if( pIndex ){

  105989.     tRowcnt *aiRowEst = 0;

  105990.     int nCol = pIndex->nKeyCol+1;

  105991. #ifdef SQLITE_ENABLE_STAT3_OR_STAT4

  105992.     /* Index.aiRowEst may already be set here if there are duplicate 

  105993.     ** sqlite_stat1 entries for this index. In that case just clobber

  105994.     ** the old data with the new instead of allocating a new array.  */

  105995.     if( pIndex->aiRowEst==0 ){

  105996.       pIndex->aiRowEst = (tRowcnt*)sqlite3MallocZero(sizeof(tRowcnt) * nCol);

  105997.       if( pIndex->aiRowEst==0 ) sqlite3OomFault(pInfo->db);

  105998.     }

  105999.     aiRowEst = pIndex->aiRowEst;

  106000. #endif

  106001.     pIndex->bUnordered = 0;

  106002.     decodeIntArray((char*)z, nCol, aiRowEst, pIndex->aiRowLogEst, pIndex);

  106003.     pIndex->hasStat1 = 1;

  106004.     if( pIndex->pPartIdxWhere==0 ){

  106005.       pTable->nRowLogEst = pIndex->aiRowLogEst[0];

  106006.       pTable->tabFlags |= TF_HasStat1;

  106007.     }

  106008.   }else{

  106009.     Index fakeIdx;

  106010.     fakeIdx.szIdxRow = pTable->szTabRow;

  106011. #ifdef SQLITE_ENABLE_COSTMULT

  106012.     fakeIdx.pTable = pTable;

  106013. #endif

  106014.     decodeIntArray((char*)z, 1, 0, &pTable->nRowLogEst, &fakeIdx);

  106015.     pTable->szTabRow = fakeIdx.szIdxRow;

  106016.     pTable->tabFlags |= TF_HasStat1;

  106017.   }

  106018. 

  106019.   return 0;

  106020. }

  106021. 

  106022. /*

  106023. ** If the Index.aSample variable is not NULL, delete the aSample[] array

  106024. ** and its contents.

  106025. */

  106026. SQLITE_PRIVATE void sqlite3DeleteIndexSamples(sqlite3 *db, Index *pIdx){

  106027. #ifdef SQLITE_ENABLE_STAT3_OR_STAT4

  106028.   if( pIdx->aSample ){

  106029.     int j;

  106030.     for(j=0; j<pIdx->nSample; j++){

  106031.       IndexSample *p = &pIdx->aSample[j];

  106032.       sqlite3DbFree(db, p->p);

  106033.     }

  106034.     sqlite3DbFree(db, pIdx->aSample);

  106035.   }

  106036.   if( db && db->pnBytesFreed==0 ){

  106037.     pIdx->nSample = 0;

  106038.     pIdx->aSample = 0;

  106039.   }

  106040. #else

  106041.   UNUSED_PARAMETER(db);

  106042.   UNUSED_PARAMETER(pIdx);

  106043. #endif /* SQLITE_ENABLE_STAT3_OR_STAT4 */

  106044. }

  106045. 

  106046. #ifdef SQLITE_ENABLE_STAT3_OR_STAT4

  106047. /*

  106048. ** Populate the pIdx->aAvgEq[] array based on the samples currently

  106049. ** stored in pIdx->aSample[]. 

  106050. */

  106051. static void initAvgEq(Index *pIdx){

  106052.   if( pIdx ){

  106053.     IndexSample *aSample = pIdx->aSample;

  106054.     IndexSample *pFinal = &aSample[pIdx->nSample-1];

  106055.     int iCol;

  106056.     int nCol = 1;

  106057.     if( pIdx->nSampleCol>1 ){

  106058.       /* If this is stat4 data, then calculate aAvgEq[] values for all

  106059.       ** sample columns except the last. The last is always set to 1, as

  106060.       ** once the trailing PK fields are considered all index keys are

  106061.       ** unique.  */

  106062.       nCol = pIdx->nSampleCol-1;

  106063.       pIdx->aAvgEq[nCol] = 1;

  106064.     }

  106065.     for(iCol=0; iCol<nCol; iCol++){

  106066.       int nSample = pIdx->nSample;

  106067.       int i;                    /* Used to iterate through samples */

  106068.       tRowcnt sumEq = 0;        /* Sum of the nEq values */

  106069.       tRowcnt avgEq = 0;

  106070.       tRowcnt nRow;             /* Number of rows in index */

  106071.       i64 nSum100 = 0;          /* Number of terms contributing to sumEq */

  106072.       i64 nDist100;             /* Number of distinct values in index */

  106073. 

  106074.       if( !pIdx->aiRowEst || iCol>=pIdx->nKeyCol || pIdx->aiRowEst[iCol+1]==0 ){

  106075.         nRow = pFinal->anLt[iCol];

  106076.         nDist100 = (i64)100 * pFinal->anDLt[iCol];

  106077.         nSample--;

  106078.       }else{

  106079.         nRow = pIdx->aiRowEst[0];

  106080.         nDist100 = ((i64)100 * pIdx->aiRowEst[0]) / pIdx->aiRowEst[iCol+1];

  106081.       }

  106082.       pIdx->nRowEst0 = nRow;

  106083. 

  106084.       /* Set nSum to the number of distinct (iCol+1) field prefixes that

  106085.       ** occur in the stat4 table for this index. Set sumEq to the sum of 

  106086.       ** the nEq values for column iCol for the same set (adding the value 

  106087.       ** only once where there exist duplicate prefixes).  */

  106088.       for(i=0; i<nSample; i++){

  106089.         if( i==(pIdx->nSample-1)

  106090.          || aSample[i].anDLt[iCol]!=aSample[i+1].anDLt[iCol] 

  106091.         ){

  106092.           sumEq += aSample[i].anEq[iCol];

  106093.           nSum100 += 100;

  106094.         }

  106095.       }

  106096. 

  106097.       if( nDist100>nSum100 && sumEq<nRow ){

  106098.         avgEq = ((i64)100 * (nRow - sumEq))/(nDist100 - nSum100);

  106099.       }

  106100.       if( avgEq==0 ) avgEq = 1;

  106101.       pIdx->aAvgEq[iCol] = avgEq;

  106102.     }

  106103.   }

  106104. }

  106105. 

  106106. /*

  106107. ** Look up an index by name.  Or, if the name of a WITHOUT ROWID table

  106108. ** is supplied instead, find the PRIMARY KEY index for that table.

  106109. */

  106110. static Index *findIndexOrPrimaryKey(

  106111.   sqlite3 *db,

  106112.   const char *zName,

  106113.   const char *zDb

  106114. ){

  106115.   Index *pIdx = sqlite3FindIndex(db, zName, zDb);

  106116.   if( pIdx==0 ){

  106117.     Table *pTab = sqlite3FindTable(db, zName, zDb);

  106118.     if( pTab && !HasRowid(pTab) ) pIdx = sqlite3PrimaryKeyIndex(pTab);

  106119.   }

  106120.   return pIdx;

  106121. }

  106122. 

  106123. /*

  106124. ** Load the content from either the sqlite_stat4 or sqlite_stat3 table 

  106125. ** into the relevant Index.aSample[] arrays.

  106126. **

  106127. ** Arguments zSql1 and zSql2 must point to SQL statements that return

  106128. ** data equivalent to the following (statements are different for stat3,

  106129. ** see the caller of this function for details):

  106130. **

  106131. **    zSql1: SELECT idx,count(*) FROM %Q.sqlite_stat4 GROUP BY idx

  106132. **    zSql2: SELECT idx,neq,nlt,ndlt,sample FROM %Q.sqlite_stat4

  106133. **

  106134. ** where %Q is replaced with the database name before the SQL is executed.

  106135. */

  106136. static int loadStatTbl(

  106137.   sqlite3 *db,                  /* Database handle */

  106138.   int bStat3,                   /* Assume single column records only */

  106139.   const char *zSql1,            /* SQL statement 1 (see above) */

  106140.   const char *zSql2,            /* SQL statement 2 (see above) */

  106141.   const char *zDb               /* Database name (e.g. "main") */

  106142. ){

  106143.   int rc;                       /* Result codes from subroutines */

  106144.   sqlite3_stmt *pStmt = 0;      /* An SQL statement being run */

  106145.   char *zSql;                   /* Text of the SQL statement */

  106146.   Index *pPrevIdx = 0;          /* Previous index in the loop */

  106147.   IndexSample *pSample;         /* A slot in pIdx->aSample[] */

  106148. 

  106149.   assert( db->lookaside.bDisable );

  106150.   zSql = sqlite3MPrintf(db, zSql1, zDb);

  106151.   if( !zSql ){

  106152.     return SQLITE_NOMEM_BKPT;

  106153.   }

  106154.   rc = sqlite3_prepare(db, zSql, -1, &pStmt, 0);

  106155.   sqlite3DbFree(db, zSql);

  106156.   if( rc ) return rc;

  106157. 

  106158.   while( sqlite3_step(pStmt)==SQLITE_ROW ){

  106159.     int nIdxCol = 1;              /* Number of columns in stat4 records */

  106160. 

  106161.     char *zIndex;   /* Index name */

  106162.     Index *pIdx;    /* Pointer to the index object */

  106163.     int nSample;    /* Number of samples */

  106164.     int nByte;      /* Bytes of space required */

  106165.     int i;          /* Bytes of space required */

  106166.     tRowcnt *pSpace;

  106167. 

  106168.     zIndex = (char *)sqlite3_column_text(pStmt, 0);

  106169.     if( zIndex==0 ) continue;

  106170.     nSample = sqlite3_column_int(pStmt, 1);

  106171.     pIdx = findIndexOrPrimaryKey(db, zIndex, zDb);

  106172.     assert( pIdx==0 || bStat3 || pIdx->nSample==0 );

  106173.     /* Index.nSample is non-zero at this point if data has already been

  106174.     ** loaded from the stat4 table. In this case ignore stat3 data.  */

  106175.     if( pIdx==0 || pIdx->nSample ) continue;

  106176.     if( bStat3==0 ){

  106177.       assert( !HasRowid(pIdx->pTable) || pIdx->nColumn==pIdx->nKeyCol+1 );

  106178.       if( !HasRowid(pIdx->pTable) && IsPrimaryKeyIndex(pIdx) ){

  106179.         nIdxCol = pIdx->nKeyCol;

  106180.       }else{

  106181.         nIdxCol = pIdx->nColumn;

  106182.       }

  106183.     }

  106184.     pIdx->nSampleCol = nIdxCol;

  106185.     nByte = sizeof(IndexSample) * nSample;

  106186.     nByte += sizeof(tRowcnt) * nIdxCol * 3 * nSample;

  106187.     nByte += nIdxCol * sizeof(tRowcnt);     /* Space for Index.aAvgEq[] */

  106188. 

  106189.     pIdx->aSample = sqlite3DbMallocZero(db, nByte);

  106190.     if( pIdx->aSample==0 ){

  106191.       sqlite3_finalize(pStmt);

  106192.       return SQLITE_NOMEM_BKPT;

  106193.     }

  106194.     pSpace = (tRowcnt*)&pIdx->aSample[nSample];

  106195.     pIdx->aAvgEq = pSpace; pSpace += nIdxCol;

  106196.     for(i=0; i<nSample; i++){

  106197.       pIdx->aSample[i].anEq = pSpace; pSpace += nIdxCol;

  106198.       pIdx->aSample[i].anLt = pSpace; pSpace += nIdxCol;

  106199.       pIdx->aSample[i].anDLt = pSpace; pSpace += nIdxCol;

  106200.     }

  106201.     assert( ((u8*)pSpace)-nByte==(u8*)(pIdx->aSample) );

  106202.   }

  106203.   rc = sqlite3_finalize(pStmt);

  106204.   if( rc ) return rc;

  106205. 

  106206.   zSql = sqlite3MPrintf(db, zSql2, zDb);

  106207.   if( !zSql ){

  106208.     return SQLITE_NOMEM_BKPT;

  106209.   }

  106210.   rc = sqlite3_prepare(db, zSql, -1, &pStmt, 0);

  106211.   sqlite3DbFree(db, zSql);

  106212.   if( rc ) return rc;

  106213. 

  106214.   while( sqlite3_step(pStmt)==SQLITE_ROW ){

  106215.     char *zIndex;                 /* Index name */

  106216.     Index *pIdx;                  /* Pointer to the index object */

  106217.     int nCol = 1;                 /* Number of columns in index */

  106218. 

  106219.     zIndex = (char *)sqlite3_column_text(pStmt, 0);

  106220.     if( zIndex==0 ) continue;

  106221.     pIdx = findIndexOrPrimaryKey(db, zIndex, zDb);

  106222.     if( pIdx==0 ) continue;

  106223.     /* This next condition is true if data has already been loaded from 

  106224.     ** the sqlite_stat4 table. In this case ignore stat3 data.  */

  106225.     nCol = pIdx->nSampleCol;

  106226.     if( bStat3 && nCol>1 ) continue;

  106227.     if( pIdx!=pPrevIdx ){

  106228.       initAvgEq(pPrevIdx);

  106229.       pPrevIdx = pIdx;

  106230.     }

  106231.     pSample = &pIdx->aSample[pIdx->nSample];

  106232.     decodeIntArray((char*)sqlite3_column_text(pStmt,1),nCol,pSample->anEq,0,0);

  106233.     decodeIntArray((char*)sqlite3_column_text(pStmt,2),nCol,pSample->anLt,0,0);

  106234.     decodeIntArray((char*)sqlite3_column_text(pStmt,3),nCol,pSample->anDLt,0,0);

  106235. 

  106236.     /* Take a copy of the sample. Add two 0x00 bytes the end of the buffer.

  106237.     ** This is in case the sample record is corrupted. In that case, the

  106238.     ** sqlite3VdbeRecordCompare() may read up to two varints past the

  106239.     ** end of the allocated buffer before it realizes it is dealing with

  106240.     ** a corrupt record. Adding the two 0x00 bytes prevents this from causing

  106241.     ** a buffer overread.  */

  106242.     pSample->n = sqlite3_column_bytes(pStmt, 4);

  106243.     pSample->p = sqlite3DbMallocZero(db, pSample->n + 2);

  106244.     if( pSample->p==0 ){

  106245.       sqlite3_finalize(pStmt);

  106246.       return SQLITE_NOMEM_BKPT;

  106247.     }

  106248.     if( pSample->n ){

  106249.       memcpy(pSample->p, sqlite3_column_blob(pStmt, 4), pSample->n);

  106250.     }

  106251.     pIdx->nSample++;

  106252.   }

  106253.   rc = sqlite3_finalize(pStmt);

  106254.   if( rc==SQLITE_OK ) initAvgEq(pPrevIdx);

  106255.   return rc;

  106256. }

  106257. 

  106258. /*

  106259. ** Load content from the sqlite_stat4 and sqlite_stat3 tables into 

  106260. ** the Index.aSample[] arrays of all indices.

  106261. */

  106262. static int loadStat4(sqlite3 *db, const char *zDb){

  106263.   int rc = SQLITE_OK;             /* Result codes from subroutines */

  106264. 

  106265.   assert( db->lookaside.bDisable );

  106266.   if( sqlite3FindTable(db, "sqlite_stat4", zDb) ){

  106267.     rc = loadStatTbl(db, 0,

  106268.       "SELECT idx,count(*) FROM %Q.sqlite_stat4 GROUP BY idx", 

  106269.       "SELECT idx,neq,nlt,ndlt,sample FROM %Q.sqlite_stat4",

  106270.       zDb

  106271.     );

  106272.   }

  106273. 

  106274.   if( rc==SQLITE_OK && sqlite3FindTable(db, "sqlite_stat3", zDb) ){

  106275.     rc = loadStatTbl(db, 1,

  106276.       "SELECT idx,count(*) FROM %Q.sqlite_stat3 GROUP BY idx", 

  106277.       "SELECT idx,neq,nlt,ndlt,sqlite_record(sample) FROM %Q.sqlite_stat3",

  106278.       zDb

  106279.     );

  106280.   }

  106281. 

  106282.   return rc;

  106283. }

  106284. #endif /* SQLITE_ENABLE_STAT3_OR_STAT4 */

  106285. 

  106286. /*

  106287. ** Load the content of the sqlite_stat1 and sqlite_stat3/4 tables. The

  106288. ** contents of sqlite_stat1 are used to populate the Index.aiRowEst[]

  106289. ** arrays. The contents of sqlite_stat3/4 are used to populate the

  106290. ** Index.aSample[] arrays.

  106291. **

  106292. ** If the sqlite_stat1 table is not present in the database, SQLITE_ERROR

  106293. ** is returned. In this case, even if SQLITE_ENABLE_STAT3/4 was defined 

  106294. ** during compilation and the sqlite_stat3/4 table is present, no data is 

  106295. ** read from it.

  106296. **

  106297. ** If SQLITE_ENABLE_STAT3/4 was defined during compilation and the 

  106298. ** sqlite_stat4 table is not present in the database, SQLITE_ERROR is

  106299. ** returned. However, in this case, data is read from the sqlite_stat1

  106300. ** table (if it is present) before returning.

  106301. **

  106302. ** If an OOM error occurs, this function always sets db->mallocFailed.

  106303. ** This means if the caller does not care about other errors, the return

  106304. ** code may be ignored.

  106305. */

  106306. SQLITE_PRIVATE int sqlite3AnalysisLoad(sqlite3 *db, int iDb){

  106307.   analysisInfo sInfo;

  106308.   HashElem *i;

  106309.   char *zSql;

  106310.   int rc = SQLITE_OK;

  106311.   Schema *pSchema = db->aDb[iDb].pSchema;

  106312. 

  106313.   assert( iDb>=0 && iDb<db->nDb );

  106314.   assert( db->aDb[iDb].pBt!=0 );

  106315. 

  106316.   /* Clear any prior statistics */

  106317.   assert( sqlite3SchemaMutexHeld(db, iDb, 0) );

  106318.   for(i=sqliteHashFirst(&pSchema->tblHash); i; i=sqliteHashNext(i)){

  106319.     Table *pTab = sqliteHashData(i);

  106320.     pTab->tabFlags &= ~TF_HasStat1;

  106321.   }

  106322.   for(i=sqliteHashFirst(&pSchema->idxHash); i; i=sqliteHashNext(i)){

  106323.     Index *pIdx = sqliteHashData(i);

  106324.     pIdx->hasStat1 = 0;

  106325. #ifdef SQLITE_ENABLE_STAT3_OR_STAT4

  106326.     sqlite3DeleteIndexSamples(db, pIdx);

  106327.     pIdx->aSample = 0;

  106328. #endif

  106329.   }

  106330. 

  106331.   /* Load new statistics out of the sqlite_stat1 table */

  106332.   sInfo.db = db;

  106333.   sInfo.zDatabase = db->aDb[iDb].zDbSName;

  106334.   if( sqlite3FindTable(db, "sqlite_stat1", sInfo.zDatabase)!=0 ){

  106335.     zSql = sqlite3MPrintf(db, 

  106336.         "SELECT tbl,idx,stat FROM %Q.sqlite_stat1", sInfo.zDatabase);

  106337.     if( zSql==0 ){

  106338.       rc = SQLITE_NOMEM_BKPT;

  106339.     }else{

  106340.       rc = sqlite3_exec(db, zSql, analysisLoader, &sInfo, 0);

  106341.       sqlite3DbFree(db, zSql);

  106342.     }

  106343.   }

  106344. 

  106345.   /* Set appropriate defaults on all indexes not in the sqlite_stat1 table */

  106346.   assert( sqlite3SchemaMutexHeld(db, iDb, 0) );

  106347.   for(i=sqliteHashFirst(&pSchema->idxHash); i; i=sqliteHashNext(i)){

  106348.     Index *pIdx = sqliteHashData(i);

  106349.     if( !pIdx->hasStat1 ) sqlite3DefaultRowEst(pIdx);

  106350.   }

  106351. 

  106352.   /* Load the statistics from the sqlite_stat4 table. */

  106353. #ifdef SQLITE_ENABLE_STAT3_OR_STAT4

  106354.   if( rc==SQLITE_OK ){

  106355.     db->lookaside.bDisable++;

  106356.     rc = loadStat4(db, sInfo.zDatabase);

  106357.     db->lookaside.bDisable--;

  106358.   }

  106359.   for(i=sqliteHashFirst(&pSchema->idxHash); i; i=sqliteHashNext(i)){

  106360.     Index *pIdx = sqliteHashData(i);

  106361.     sqlite3_free(pIdx->aiRowEst);

  106362.     pIdx->aiRowEst = 0;

  106363.   }

  106364. #endif

  106365. 

  106366.   if( rc==SQLITE_NOMEM ){

  106367.     sqlite3OomFault(db);

  106368.   }

  106369.   return rc;

  106370. }

  106371. 

  106372. 

  106373. #endif /* SQLITE_OMIT_ANALYZE */

  106374. 

  106375. /************** End of analyze.c *********************************************/

  106376. /************** Begin file attach.c ******************************************/

  106377. /*

  106378. ** 2003 April 6

  106379. **

  106380. ** The author disclaims copyright to this source code.  In place of

  106381. ** a legal notice, here is a blessing:

  106382. **

  106383. **    May you do good and not evil.

  106384. **    May you find forgiveness for yourself and forgive others.

  106385. **    May you share freely, never taking more than you give.

  106386. **

  106387. *************************************************************************

  106388. ** This file contains code used to implement the ATTACH and DETACH commands.

  106389. */

  106390. /* #include "sqliteInt.h" */

  106391. 

  106392. #ifndef SQLITE_OMIT_ATTACH

  106393. /*

  106394. ** Resolve an expression that was part of an ATTACH or DETACH statement. This

  106395. ** is slightly different from resolving a normal SQL expression, because simple

  106396. ** identifiers are treated as strings, not possible column names or aliases.

  106397. **

  106398. ** i.e. if the parser sees:

  106399. **

  106400. **     ATTACH DATABASE abc AS def

  106401. **

  106402. ** it treats the two expressions as literal strings 'abc' and 'def' instead of

  106403. ** looking for columns of the same name.

  106404. **

  106405. ** This only applies to the root node of pExpr, so the statement:

  106406. **

  106407. **     ATTACH DATABASE abc||def AS 'db2'

  106408. **

  106409. ** will fail because neither abc or def can be resolved.

  106410. */

  106411. static int resolveAttachExpr(NameContext *pName, Expr *pExpr)

  106412. {

  106413.   int rc = SQLITE_OK;

  106414.   if( pExpr ){

  106415.     if( pExpr->op!=TK_ID ){

  106416.       rc = sqlite3ResolveExprNames(pName, pExpr);

  106417.     }else{

  106418.       pExpr->op = TK_STRING;

  106419.     }

  106420.   }

  106421.   return rc;

  106422. }

  106423. 

  106424. /*

  106425. ** An SQL user-function registered to do the work of an ATTACH statement. The

  106426. ** three arguments to the function come directly from an attach statement:

  106427. **

  106428. **     ATTACH DATABASE x AS y KEY z

  106429. **

  106430. **     SELECT sqlite_attach(x, y, z)

  106431. **

  106432. ** If the optional "KEY z" syntax is omitted, an SQL NULL is passed as the

  106433. ** third argument.

  106434. **

  106435. ** If the db->init.reopenMemdb flags is set, then instead of attaching a

  106436. ** new database, close the database on db->init.iDb and reopen it as an

  106437. ** empty MemDB.

  106438. */

  106439. static void attachFunc(

  106440.   sqlite3_context *context,

  106441.   int NotUsed,

  106442.   sqlite3_value **argv

  106443. ){

  106444.   int i;

  106445.   int rc = 0;

  106446.   sqlite3 *db = sqlite3_context_db_handle(context);

  106447.   const char *zName;

  106448.   const char *zFile;

  106449.   char *zPath = 0;

  106450.   char *zErr = 0;

  106451.   unsigned int flags;

  106452.   Db *aNew;                 /* New array of Db pointers */

  106453.   Db *pNew;                 /* Db object for the newly attached database */

  106454.   char *zErrDyn = 0;

  106455.   sqlite3_vfs *pVfs;

  106456. 

  106457.   UNUSED_PARAMETER(NotUsed);

  106458.   zFile = (const char *)sqlite3_value_text(argv[0]);

  106459.   zName = (const char *)sqlite3_value_text(argv[1]);

  106460.   if( zFile==0 ) zFile = "";

  106461.   if( zName==0 ) zName = "";

  106462. 

  106463. #ifdef SQLITE_ENABLE_DESERIALIZE

  106464. # define REOPEN_AS_MEMDB(db)  (db->init.reopenMemdb)

  106465. #else

  106466. # define REOPEN_AS_MEMDB(db)  (0)

  106467. #endif

  106468. 

  106469.   if( REOPEN_AS_MEMDB(db) ){

  106470.     /* This is not a real ATTACH.  Instead, this routine is being called

  106471.     ** from sqlite3_deserialize() to close database db->init.iDb and

  106472.     ** reopen it as a MemDB */

  106473.     pVfs = sqlite3_vfs_find("memdb");

  106474.     if( pVfs==0 ) return;

  106475.     pNew = &db->aDb[db->init.iDb];

  106476.     if( pNew->pBt ) sqlite3BtreeClose(pNew->pBt);

  106477.     pNew->pBt = 0;

  106478.     pNew->pSchema = 0;

  106479.     rc = sqlite3BtreeOpen(pVfs, "x\0", db, &pNew->pBt, 0, SQLITE_OPEN_MAIN_DB);

  106480.   }else{

  106481.     /* This is a real ATTACH

  106482.     **

  106483.     ** Check for the following errors:

  106484.     **

  106485.     **     * Too many attached databases,

  106486.     **     * Transaction currently open

  106487.     **     * Specified database name already being used.

  106488.     */

  106489.     if( db->nDb>=db->aLimit[SQLITE_LIMIT_ATTACHED]+2 ){

  106490.       zErrDyn = sqlite3MPrintf(db, "too many attached databases - max %d", 

  106491.         db->aLimit[SQLITE_LIMIT_ATTACHED]

  106492.       );

  106493.       goto attach_error;

  106494.     }

  106495.     for(i=0; i<db->nDb; i++){

  106496.       char *z = db->aDb[i].zDbSName;

  106497.       assert( z && zName );

  106498.       if( sqlite3StrICmp(z, zName)==0 ){

  106499.         zErrDyn = sqlite3MPrintf(db, "database %s is already in use", zName);

  106500.         goto attach_error;

  106501.       }

  106502.     }

  106503.   

  106504.     /* Allocate the new entry in the db->aDb[] array and initialize the schema

  106505.     ** hash tables.

  106506.     */

  106507.     if( db->aDb==db->aDbStatic ){

  106508.       aNew = sqlite3DbMallocRawNN(db, sizeof(db->aDb[0])*3 );

  106509.       if( aNew==0 ) return;

  106510.       memcpy(aNew, db->aDb, sizeof(db->aDb[0])*2);

  106511.     }else{

  106512.       aNew = sqlite3DbRealloc(db, db->aDb, sizeof(db->aDb[0])*(db->nDb+1) );

  106513.       if( aNew==0 ) return;

  106514.     }

  106515.     db->aDb = aNew;

  106516.     pNew = &db->aDb[db->nDb];

  106517.     memset(pNew, 0, sizeof(*pNew));

  106518.   

  106519.     /* Open the database file. If the btree is successfully opened, use

  106520.     ** it to obtain the database schema. At this point the schema may

  106521.     ** or may not be initialized.

  106522.     */

  106523.     flags = db->openFlags;

  106524.     rc = sqlite3ParseUri(db->pVfs->zName, zFile, &flags, &pVfs, &zPath, &zErr);

  106525.     if( rc!=SQLITE_OK ){

  106526.       if( rc==SQLITE_NOMEM ) sqlite3OomFault(db);

  106527.       sqlite3_result_error(context, zErr, -1);

  106528.       sqlite3_free(zErr);

  106529.       return;

  106530.     }

  106531.     assert( pVfs );

  106532.     flags |= SQLITE_OPEN_MAIN_DB;

  106533.     rc = sqlite3BtreeOpen(pVfs, zPath, db, &pNew->pBt, 0, flags);

  106534.     db->nDb++;

  106535.     pNew->zDbSName = sqlite3DbStrDup(db, zName);

  106536.   }

  106537.   db->noSharedCache = 0;

  106538.   if( rc==SQLITE_CONSTRAINT ){

  106539.     rc = SQLITE_ERROR;

  106540.     zErrDyn = sqlite3MPrintf(db, "database is already attached");

  106541.   }else if( rc==SQLITE_OK ){

  106542.     Pager *pPager;

  106543.     pNew->pSchema = sqlite3SchemaGet(db, pNew->pBt);

  106544.     if( !pNew->pSchema ){

  106545.       rc = SQLITE_NOMEM_BKPT;

  106546.     }else if( pNew->pSchema->file_format && pNew->pSchema->enc!=ENC(db) ){

  106547.       zErrDyn = sqlite3MPrintf(db, 

  106548.         "attached databases must use the same text encoding as main database");

  106549.       rc = SQLITE_ERROR;

  106550.     }

  106551.     sqlite3BtreeEnter(pNew->pBt);

  106552.     pPager = sqlite3BtreePager(pNew->pBt);

  106553.     sqlite3PagerLockingMode(pPager, db->dfltLockMode);

  106554.     sqlite3BtreeSecureDelete(pNew->pBt,

  106555.                              sqlite3BtreeSecureDelete(db->aDb[0].pBt,-1) );

  106556. #ifndef SQLITE_OMIT_PAGER_PRAGMAS

  106557.     sqlite3BtreeSetPagerFlags(pNew->pBt,

  106558.                       PAGER_SYNCHRONOUS_FULL | (db->flags & PAGER_FLAGS_MASK));

  106559. #endif

  106560.     sqlite3BtreeLeave(pNew->pBt);

  106561.   }

  106562.   pNew->safety_level = SQLITE_DEFAULT_SYNCHRONOUS+1;

  106563.   if( rc==SQLITE_OK && pNew->zDbSName==0 ){

  106564.     rc = SQLITE_NOMEM_BKPT;

  106565.   }

  106566. 

  106567. 

  106568. #ifdef SQLITE_HAS_CODEC

  106569.   if( rc==SQLITE_OK ){

  106570.     extern int sqlite3CodecAttach(sqlite3*, int, const void*, int);

  106571.     extern void sqlite3CodecGetKey(sqlite3*, int, void**, int*);

  106572.     int nKey;

  106573.     char *zKey;

  106574.     int t = sqlite3_value_type(argv[2]);

  106575.     switch( t ){

  106576.       case SQLITE_INTEGER:

  106577.       case SQLITE_FLOAT:

  106578.         zErrDyn = sqlite3DbStrDup(db, "Invalid key value");

  106579.         rc = SQLITE_ERROR;

  106580.         break;

  106581.         

  106582.       case SQLITE_TEXT:

  106583.       case SQLITE_BLOB:

  106584.         nKey = sqlite3_value_bytes(argv[2]);

  106585.         zKey = (char *)sqlite3_value_blob(argv[2]);

  106586.         rc = sqlite3CodecAttach(db, db->nDb-1, zKey, nKey);

  106587.         break;

  106588. 

  106589.       case SQLITE_NULL:

  106590.         /* No key specified.  Use the key from URI filename, or if none,

  106591.         ** use the key from the main database. */

  106592.         if( sqlite3CodecQueryParameters(db, zName, zPath)==0 ){

  106593.           sqlite3CodecGetKey(db, 0, (void**)&zKey, &nKey);

  106594.           if( nKey || sqlite3BtreeGetOptimalReserve(db->aDb[0].pBt)>0 ){

  106595.             rc = sqlite3CodecAttach(db, db->nDb-1, zKey, nKey);

  106596.           }

  106597.         }

  106598.         break;

  106599.     }

  106600.   }

  106601. #endif

  106602.   sqlite3_free( zPath );

  106603. 

  106604.   /* If the file was opened successfully, read the schema for the new database.

  106605.   ** If this fails, or if opening the file failed, then close the file and 

  106606.   ** remove the entry from the db->aDb[] array. i.e. put everything back the

  106607.   ** way we found it.

  106608.   */

  106609.   if( rc==SQLITE_OK ){

  106610.     sqlite3BtreeEnterAll(db);

  106611.     db->init.iDb = 0;

  106612.     db->mDbFlags &= ~(DBFLAG_SchemaKnownOk);

  106613.     if( !REOPEN_AS_MEMDB(db) ){

  106614.       rc = sqlite3Init(db, &zErrDyn);

  106615.     }

  106616.     sqlite3BtreeLeaveAll(db);

  106617.     assert( zErrDyn==0 || rc!=SQLITE_OK );

  106618.   }

  106619. #ifdef SQLITE_USER_AUTHENTICATION

  106620.   if( rc==SQLITE_OK && !REOPEN_AS_MEMDB(db) ){

  106621.     u8 newAuth = 0;

  106622.     rc = sqlite3UserAuthCheckLogin(db, zName, &newAuth);

  106623.     if( newAuth<db->auth.authLevel ){

  106624.       rc = SQLITE_AUTH_USER;

  106625.     }

  106626.   }

  106627. #endif

  106628.   if( rc ){

  106629.     if( !REOPEN_AS_MEMDB(db) ){

  106630.       int iDb = db->nDb - 1;

  106631.       assert( iDb>=2 );

  106632.       if( db->aDb[iDb].pBt ){

  106633.         sqlite3BtreeClose(db->aDb[iDb].pBt);

  106634.         db->aDb[iDb].pBt = 0;

  106635.         db->aDb[iDb].pSchema = 0;

  106636.       }

  106637.       sqlite3ResetAllSchemasOfConnection(db);

  106638.       db->nDb = iDb;

  106639.       if( rc==SQLITE_NOMEM || rc==SQLITE_IOERR_NOMEM ){

  106640.         sqlite3OomFault(db);

  106641.         sqlite3DbFree(db, zErrDyn);

  106642.         zErrDyn = sqlite3MPrintf(db, "out of memory");

  106643.       }else if( zErrDyn==0 ){

  106644.         zErrDyn = sqlite3MPrintf(db, "unable to open database: %s", zFile);

  106645.       }

  106646.     }

  106647.     goto attach_error;

  106648.   }

  106649.   

  106650.   return;

  106651. 

  106652. attach_error:

  106653.   /* Return an error if we get here */

  106654.   if( zErrDyn ){

  106655.     sqlite3_result_error(context, zErrDyn, -1);

  106656.     sqlite3DbFree(db, zErrDyn);

  106657.   }

  106658.   if( rc ) sqlite3_result_error_code(context, rc);

  106659. }

  106660. 

  106661. /*

  106662. ** An SQL user-function registered to do the work of an DETACH statement. The

  106663. ** three arguments to the function come directly from a detach statement:

  106664. **

  106665. **     DETACH DATABASE x

  106666. **

  106667. **     SELECT sqlite_detach(x)

  106668. */

  106669. static void detachFunc(

  106670.   sqlite3_context *context,

  106671.   int NotUsed,

  106672.   sqlite3_value **argv

  106673. ){

  106674.   const char *zName = (const char *)sqlite3_value_text(argv[0]);

  106675.   sqlite3 *db = sqlite3_context_db_handle(context);

  106676.   int i;

  106677.   Db *pDb = 0;

  106678.   char zErr[128];

  106679. 

  106680.   UNUSED_PARAMETER(NotUsed);

  106681. 

  106682.   if( zName==0 ) zName = "";

  106683.   for(i=0; i<db->nDb; i++){

  106684.     pDb = &db->aDb[i];

  106685.     if( pDb->pBt==0 ) continue;

  106686.     if( sqlite3StrICmp(pDb->zDbSName, zName)==0 ) break;

  106687.   }

  106688. 

  106689.   if( i>=db->nDb ){

  106690.     sqlite3_snprintf(sizeof(zErr),zErr, "no such database: %s", zName);

  106691.     goto detach_error;

  106692.   }

  106693.   if( i<2 ){

  106694.     sqlite3_snprintf(sizeof(zErr),zErr, "cannot detach database %s", zName);

  106695.     goto detach_error;

  106696.   }

  106697.   if( sqlite3BtreeIsInReadTrans(pDb->pBt) || sqlite3BtreeIsInBackup(pDb->pBt) ){

  106698.     sqlite3_snprintf(sizeof(zErr),zErr, "database %s is locked", zName);

  106699.     goto detach_error;

  106700.   }

  106701. 

  106702.   sqlite3BtreeClose(pDb->pBt);

  106703.   pDb->pBt = 0;

  106704.   pDb->pSchema = 0;

  106705.   sqlite3CollapseDatabaseArray(db);

  106706.   return;

  106707. 

  106708. detach_error:

  106709.   sqlite3_result_error(context, zErr, -1);

  106710. }

  106711. 

  106712. /*

  106713. ** This procedure generates VDBE code for a single invocation of either the

  106714. ** sqlite_detach() or sqlite_attach() SQL user functions.

  106715. */

  106716. static void codeAttach(

  106717.   Parse *pParse,       /* The parser context */

  106718.   int type,            /* Either SQLITE_ATTACH or SQLITE_DETACH */

  106719.   FuncDef const *pFunc,/* FuncDef wrapper for detachFunc() or attachFunc() */

  106720.   Expr *pAuthArg,      /* Expression to pass to authorization callback */

  106721.   Expr *pFilename,     /* Name of database file */

  106722.   Expr *pDbname,       /* Name of the database to use internally */

  106723.   Expr *pKey           /* Database key for encryption extension */

  106724. ){

  106725.   int rc;

  106726.   NameContext sName;

  106727.   Vdbe *v;

  106728.   sqlite3* db = pParse->db;

  106729.   int regArgs;

  106730. 

  106731.   if( pParse->nErr ) goto attach_end;

  106732.   memset(&sName, 0, sizeof(NameContext));

  106733.   sName.pParse = pParse;

  106734. 

  106735.   if( 

  106736.       SQLITE_OK!=(rc = resolveAttachExpr(&sName, pFilename)) ||

  106737.       SQLITE_OK!=(rc = resolveAttachExpr(&sName, pDbname)) ||

  106738.       SQLITE_OK!=(rc = resolveAttachExpr(&sName, pKey))

  106739.   ){

  106740.     goto attach_end;

  106741.   }

  106742. 

  106743. #ifndef SQLITE_OMIT_AUTHORIZATION

  106744.   if( pAuthArg ){

  106745.     char *zAuthArg;

  106746.     if( pAuthArg->op==TK_STRING ){

  106747.       zAuthArg = pAuthArg->u.zToken;

  106748.     }else{

  106749.       zAuthArg = 0;

  106750.     }

  106751.     rc = sqlite3AuthCheck(pParse, type, zAuthArg, 0, 0);

  106752.     if(rc!=SQLITE_OK ){

  106753.       goto attach_end;

  106754.     }

  106755.   }

  106756. #endif /* SQLITE_OMIT_AUTHORIZATION */

  106757. 

  106758. 

  106759.   v = sqlite3GetVdbe(pParse);

  106760.   regArgs = sqlite3GetTempRange(pParse, 4);

  106761.   sqlite3ExprCode(pParse, pFilename, regArgs);

  106762.   sqlite3ExprCode(pParse, pDbname, regArgs+1);

  106763.   sqlite3ExprCode(pParse, pKey, regArgs+2);

  106764. 

  106765.   assert( v || db->mallocFailed );

  106766.   if( v ){

  106767.     sqlite3VdbeAddOp4(v, OP_Function0, 0, regArgs+3-pFunc->nArg, regArgs+3,

  106768.                       (char *)pFunc, P4_FUNCDEF);

  106769.     assert( pFunc->nArg==-1 || (pFunc->nArg&0xff)==pFunc->nArg );

  106770.     sqlite3VdbeChangeP5(v, (u8)(pFunc->nArg));

  106771.  

  106772.     /* Code an OP_Expire. For an ATTACH statement, set P1 to true (expire this

  106773.     ** statement only). For DETACH, set it to false (expire all existing

  106774.     ** statements).

  106775.     */

  106776.     sqlite3VdbeAddOp1(v, OP_Expire, (type==SQLITE_ATTACH));

  106777.   }

  106778.   

  106779. attach_end:

  106780.   sqlite3ExprDelete(db, pFilename);

  106781.   sqlite3ExprDelete(db, pDbname);

  106782.   sqlite3ExprDelete(db, pKey);

  106783. }

  106784. 

  106785. /*

  106786. ** Called by the parser to compile a DETACH statement.

  106787. **

  106788. **     DETACH pDbname

  106789. */

  106790. SQLITE_PRIVATE void sqlite3Detach(Parse *pParse, Expr *pDbname){

  106791.   static const FuncDef detach_func = {

  106792.     1,                /* nArg */

  106793.     SQLITE_UTF8,      /* funcFlags */

  106794.     0,                /* pUserData */

  106795.     0,                /* pNext */

  106796.     detachFunc,       /* xSFunc */

  106797.     0,                /* xFinalize */

  106798.     0, 0,             /* xValue, xInverse */

  106799.     "sqlite_detach",  /* zName */

  106800.     {0}

  106801.   };

  106802.   codeAttach(pParse, SQLITE_DETACH, &detach_func, pDbname, 0, 0, pDbname);

  106803. }

  106804. 

  106805. /*

  106806. ** Called by the parser to compile an ATTACH statement.

  106807. **

  106808. **     ATTACH p AS pDbname KEY pKey

  106809. */

  106810. SQLITE_PRIVATE void sqlite3Attach(Parse *pParse, Expr *p, Expr *pDbname, Expr *pKey){

  106811.   static const FuncDef attach_func = {

  106812.     3,                /* nArg */

  106813.     SQLITE_UTF8,      /* funcFlags */

  106814.     0,                /* pUserData */

  106815.     0,                /* pNext */

  106816.     attachFunc,       /* xSFunc */

  106817.     0,                /* xFinalize */

  106818.     0, 0,             /* xValue, xInverse */

  106819.     "sqlite_attach",  /* zName */

  106820.     {0}

  106821.   };

  106822.   codeAttach(pParse, SQLITE_ATTACH, &attach_func, p, p, pDbname, pKey);

  106823. }

  106824. #endif /* SQLITE_OMIT_ATTACH */

  106825. 

  106826. /*

  106827. ** Initialize a DbFixer structure.  This routine must be called prior

  106828. ** to passing the structure to one of the sqliteFixAAAA() routines below.

  106829. */

  106830. SQLITE_PRIVATE void sqlite3FixInit(

  106831.   DbFixer *pFix,      /* The fixer to be initialized */

  106832.   Parse *pParse,      /* Error messages will be written here */

  106833.   int iDb,            /* This is the database that must be used */

  106834.   const char *zType,  /* "view", "trigger", or "index" */

  106835.   const Token *pName  /* Name of the view, trigger, or index */

  106836. ){

  106837.   sqlite3 *db;

  106838. 

  106839.   db = pParse->db;

  106840.   assert( db->nDb>iDb );

  106841.   pFix->pParse = pParse;

  106842.   pFix->zDb = db->aDb[iDb].zDbSName;

  106843.   pFix->pSchema = db->aDb[iDb].pSchema;

  106844.   pFix->zType = zType;

  106845.   pFix->pName = pName;

  106846.   pFix->bVarOnly = (iDb==1);

  106847. }

  106848. 

  106849. /*

  106850. ** The following set of routines walk through the parse tree and assign

  106851. ** a specific database to all table references where the database name

  106852. ** was left unspecified in the original SQL statement.  The pFix structure

  106853. ** must have been initialized by a prior call to sqlite3FixInit().

  106854. **

  106855. ** These routines are used to make sure that an index, trigger, or

  106856. ** view in one database does not refer to objects in a different database.

  106857. ** (Exception: indices, triggers, and views in the TEMP database are

  106858. ** allowed to refer to anything.)  If a reference is explicitly made

  106859. ** to an object in a different database, an error message is added to

  106860. ** pParse->zErrMsg and these routines return non-zero.  If everything

  106861. ** checks out, these routines return 0.

  106862. */

  106863. SQLITE_PRIVATE int sqlite3FixSrcList(

  106864.   DbFixer *pFix,       /* Context of the fixation */

  106865.   SrcList *pList       /* The Source list to check and modify */

  106866. ){

  106867.   int i;

  106868.   const char *zDb;

  106869.   struct SrcList_item *pItem;

  106870. 

  106871.   if( NEVER(pList==0) ) return 0;

  106872.   zDb = pFix->zDb;

  106873.   for(i=0, pItem=pList->a; i<pList->nSrc; i++, pItem++){

  106874.     if( pFix->bVarOnly==0 ){

  106875.       if( pItem->zDatabase && sqlite3StrICmp(pItem->zDatabase, zDb) ){

  106876.         sqlite3ErrorMsg(pFix->pParse,

  106877.             "%s %T cannot reference objects in database %s",

  106878.             pFix->zType, pFix->pName, pItem->zDatabase);

  106879.         return 1;

  106880.       }

  106881.       sqlite3DbFree(pFix->pParse->db, pItem->zDatabase);

  106882.       pItem->zDatabase = 0;

  106883.       pItem->pSchema = pFix->pSchema;

  106884.     }

  106885. #if !defined(SQLITE_OMIT_VIEW) || !defined(SQLITE_OMIT_TRIGGER)

  106886.     if( sqlite3FixSelect(pFix, pItem->pSelect) ) return 1;

  106887.     if( sqlite3FixExpr(pFix, pItem->pOn) ) return 1;

  106888. #endif

  106889.     if( pItem->fg.isTabFunc && sqlite3FixExprList(pFix, pItem->u1.pFuncArg) ){

  106890.       return 1;

  106891.     }

  106892.   }

  106893.   return 0;

  106894. }

  106895. #if !defined(SQLITE_OMIT_VIEW) || !defined(SQLITE_OMIT_TRIGGER)

  106896. SQLITE_PRIVATE int sqlite3FixSelect(

  106897.   DbFixer *pFix,       /* Context of the fixation */

  106898.   Select *pSelect      /* The SELECT statement to be fixed to one database */

  106899. ){

  106900.   while( pSelect ){

  106901.     if( sqlite3FixExprList(pFix, pSelect->pEList) ){

  106902.       return 1;

  106903.     }

  106904.     if( sqlite3FixSrcList(pFix, pSelect->pSrc) ){

  106905.       return 1;

  106906.     }

  106907.     if( sqlite3FixExpr(pFix, pSelect->pWhere) ){

  106908.       return 1;

  106909.     }

  106910.     if( sqlite3FixExprList(pFix, pSelect->pGroupBy) ){

  106911.       return 1;

  106912.     }

  106913.     if( sqlite3FixExpr(pFix, pSelect->pHaving) ){

  106914.       return 1;

  106915.     }

  106916.     if( sqlite3FixExprList(pFix, pSelect->pOrderBy) ){

  106917.       return 1;

  106918.     }

  106919.     if( sqlite3FixExpr(pFix, pSelect->pLimit) ){

  106920.       return 1;

  106921.     }

  106922.     if( pSelect->pWith ){

  106923.       int i;

  106924.       for(i=0; i<pSelect->pWith->nCte; i++){

  106925.         if( sqlite3FixSelect(pFix, pSelect->pWith->a[i].pSelect) ){

  106926.           return 1;

  106927.         }

  106928.       }

  106929.     }

  106930.     pSelect = pSelect->pPrior;

  106931.   }

  106932.   return 0;

  106933. }

  106934. SQLITE_PRIVATE int sqlite3FixExpr(

  106935.   DbFixer *pFix,     /* Context of the fixation */

  106936.   Expr *pExpr        /* The expression to be fixed to one database */

  106937. ){

  106938.   while( pExpr ){

  106939.     if( pExpr->op==TK_VARIABLE ){

  106940.       if( pFix->pParse->db->init.busy ){

  106941.         pExpr->op = TK_NULL;

  106942.       }else{

  106943.         sqlite3ErrorMsg(pFix->pParse, "%s cannot use variables", pFix->zType);

  106944.         return 1;

  106945.       }

  106946.     }

  106947.     if( ExprHasProperty(pExpr, EP_TokenOnly|EP_Leaf) ) break;

  106948.     if( ExprHasProperty(pExpr, EP_xIsSelect) ){

  106949.       if( sqlite3FixSelect(pFix, pExpr->x.pSelect) ) return 1;

  106950.     }else{

  106951.       if( sqlite3FixExprList(pFix, pExpr->x.pList) ) return 1;

  106952.     }

  106953.     if( sqlite3FixExpr(pFix, pExpr->pRight) ){

  106954.       return 1;

  106955.     }

  106956.     pExpr = pExpr->pLeft;

  106957.   }

  106958.   return 0;

  106959. }

  106960. SQLITE_PRIVATE int sqlite3FixExprList(

  106961.   DbFixer *pFix,     /* Context of the fixation */

  106962.   ExprList *pList    /* The expression to be fixed to one database */

  106963. ){

  106964.   int i;

  106965.   struct ExprList_item *pItem;

  106966.   if( pList==0 ) return 0;

  106967.   for(i=0, pItem=pList->a; i<pList->nExpr; i++, pItem++){

  106968.     if( sqlite3FixExpr(pFix, pItem->pExpr) ){

  106969.       return 1;

  106970.     }

  106971.   }

  106972.   return 0;

  106973. }

  106974. #endif

  106975. 

  106976. #ifndef SQLITE_OMIT_TRIGGER

  106977. SQLITE_PRIVATE int sqlite3FixTriggerStep(

  106978.   DbFixer *pFix,     /* Context of the fixation */

  106979.   TriggerStep *pStep /* The trigger step be fixed to one database */

  106980. ){

  106981.   while( pStep ){

  106982.     if( sqlite3FixSelect(pFix, pStep->pSelect) ){

  106983.       return 1;

  106984.     }

  106985.     if( sqlite3FixExpr(pFix, pStep->pWhere) ){

  106986.       return 1;

  106987.     }

  106988.     if( sqlite3FixExprList(pFix, pStep->pExprList) ){

  106989.       return 1;

  106990.     }

  106991. #ifndef SQLITE_OMIT_UPSERT

  106992.     if( pStep->pUpsert ){

  106993.       Upsert *pUp = pStep->pUpsert;

  106994.       if( sqlite3FixExprList(pFix, pUp->pUpsertTarget)

  106995.        || sqlite3FixExpr(pFix, pUp->pUpsertTargetWhere)

  106996.        || sqlite3FixExprList(pFix, pUp->pUpsertSet)

  106997.        || sqlite3FixExpr(pFix, pUp->pUpsertWhere)

  106998.       ){

  106999.         return 1;

  107000.       }

  107001.     }

  107002. #endif

  107003.     pStep = pStep->pNext;

  107004.   }

  107005.   return 0;

  107006. }

  107007. #endif

  107008. 

  107009. /************** End of attach.c **********************************************/

  107010. /************** Begin file auth.c ********************************************/

  107011. /*

  107012. ** 2003 January 11

  107013. **

  107014. ** The author disclaims copyright to this source code.  In place of

  107015. ** a legal notice, here is a blessing:

  107016. **

  107017. **    May you do good and not evil.

  107018. **    May you find forgiveness for yourself and forgive others.

  107019. **    May you share freely, never taking more than you give.

  107020. **

  107021. *************************************************************************

  107022. ** This file contains code used to implement the sqlite3_set_authorizer()

  107023. ** API.  This facility is an optional feature of the library.  Embedded

  107024. ** systems that do not need this facility may omit it by recompiling

  107025. ** the library with -DSQLITE_OMIT_AUTHORIZATION=1

  107026. */

  107027. /* #include "sqliteInt.h" */

  107028. 

  107029. /*

  107030. ** All of the code in this file may be omitted by defining a single

  107031. ** macro.

  107032. */

  107033. #ifndef SQLITE_OMIT_AUTHORIZATION

  107034. 

  107035. /*

  107036. ** Set or clear the access authorization function.

  107037. **

  107038. ** The access authorization function is be called during the compilation

  107039. ** phase to verify that the user has read and/or write access permission on

  107040. ** various fields of the database.  The first argument to the auth function

  107041. ** is a copy of the 3rd argument to this routine.  The second argument

  107042. ** to the auth function is one of these constants:

  107043. **

  107044. **       SQLITE_CREATE_INDEX

  107045. **       SQLITE_CREATE_TABLE

  107046. **       SQLITE_CREATE_TEMP_INDEX

  107047. **       SQLITE_CREATE_TEMP_TABLE

  107048. **       SQLITE_CREATE_TEMP_TRIGGER

  107049. **       SQLITE_CREATE_TEMP_VIEW

  107050. **       SQLITE_CREATE_TRIGGER

  107051. **       SQLITE_CREATE_VIEW

  107052. **       SQLITE_DELETE

  107053. **       SQLITE_DROP_INDEX

  107054. **       SQLITE_DROP_TABLE

  107055. **       SQLITE_DROP_TEMP_INDEX

  107056. **       SQLITE_DROP_TEMP_TABLE

  107057. **       SQLITE_DROP_TEMP_TRIGGER

  107058. **       SQLITE_DROP_TEMP_VIEW

  107059. **       SQLITE_DROP_TRIGGER

  107060. **       SQLITE_DROP_VIEW

  107061. **       SQLITE_INSERT

  107062. **       SQLITE_PRAGMA

  107063. **       SQLITE_READ

  107064. **       SQLITE_SELECT

  107065. **       SQLITE_TRANSACTION

  107066. **       SQLITE_UPDATE

  107067. **

  107068. ** The third and fourth arguments to the auth function are the name of

  107069. ** the table and the column that are being accessed.  The auth function

  107070. ** should return either SQLITE_OK, SQLITE_DENY, or SQLITE_IGNORE.  If

  107071. ** SQLITE_OK is returned, it means that access is allowed.  SQLITE_DENY

  107072. ** means that the SQL statement will never-run - the sqlite3_exec() call

  107073. ** will return with an error.  SQLITE_IGNORE means that the SQL statement

  107074. ** should run but attempts to read the specified column will return NULL

  107075. ** and attempts to write the column will be ignored.

  107076. **

  107077. ** Setting the auth function to NULL disables this hook.  The default

  107078. ** setting of the auth function is NULL.

  107079. */

  107080. SQLITE_API int sqlite3_set_authorizer(

  107081.   sqlite3 *db,

  107082.   int (*xAuth)(void*,int,const char*,const char*,const char*,const char*),

  107083.   void *pArg

  107084. ){

  107085. #ifdef SQLITE_ENABLE_API_ARMOR

  107086.   if( !sqlite3SafetyCheckOk(db) ) return SQLITE_MISUSE_BKPT;

  107087. #endif

  107088.   sqlite3_mutex_enter(db->mutex);

  107089.   db->xAuth = (sqlite3_xauth)xAuth;

  107090.   db->pAuthArg = pArg;

  107091.   sqlite3ExpirePreparedStatements(db, 0);

  107092.   sqlite3_mutex_leave(db->mutex);

  107093.   return SQLITE_OK;

  107094. }

  107095. 

  107096. /*

  107097. ** Write an error message into pParse->zErrMsg that explains that the

  107098. ** user-supplied authorization function returned an illegal value.

  107099. */

  107100. static void sqliteAuthBadReturnCode(Parse *pParse){

  107101.   sqlite3ErrorMsg(pParse, "authorizer malfunction");

  107102.   pParse->rc = SQLITE_ERROR;

  107103. }

  107104. 

  107105. /*

  107106. ** Invoke the authorization callback for permission to read column zCol from

  107107. ** table zTab in database zDb. This function assumes that an authorization

  107108. ** callback has been registered (i.e. that sqlite3.xAuth is not NULL).

  107109. **

  107110. ** If SQLITE_IGNORE is returned and pExpr is not NULL, then pExpr is changed

  107111. ** to an SQL NULL expression. Otherwise, if pExpr is NULL, then SQLITE_IGNORE

  107112. ** is treated as SQLITE_DENY. In this case an error is left in pParse.

  107113. */

  107114. SQLITE_PRIVATE int sqlite3AuthReadCol(

  107115.   Parse *pParse,                  /* The parser context */

  107116.   const char *zTab,               /* Table name */

  107117.   const char *zCol,               /* Column name */

  107118.   int iDb                         /* Index of containing database. */

  107119. ){

  107120.   sqlite3 *db = pParse->db;          /* Database handle */

  107121.   char *zDb = db->aDb[iDb].zDbSName; /* Schema name of attached database */

  107122.   int rc;                            /* Auth callback return code */

  107123. 

  107124.   if( db->init.busy ) return SQLITE_OK;

  107125.   rc = db->xAuth(db->pAuthArg, SQLITE_READ, zTab,zCol,zDb,pParse->zAuthContext

  107126. #ifdef SQLITE_USER_AUTHENTICATION

  107127.                  ,db->auth.zAuthUser

  107128. #endif

  107129.                 );

  107130.   if( rc==SQLITE_DENY ){

  107131.     char *z = sqlite3_mprintf("%s.%s", zTab, zCol);

  107132.     if( db->nDb>2 || iDb!=0 ) z = sqlite3_mprintf("%s.%z", zDb, z);

  107133.     sqlite3ErrorMsg(pParse, "access to %z is prohibited", z);

  107134.     pParse->rc = SQLITE_AUTH;

  107135.   }else if( rc!=SQLITE_IGNORE && rc!=SQLITE_OK ){

  107136.     sqliteAuthBadReturnCode(pParse);

  107137.   }

  107138.   return rc;

  107139. }

  107140. 

  107141. /*

  107142. ** The pExpr should be a TK_COLUMN expression.  The table referred to

  107143. ** is in pTabList or else it is the NEW or OLD table of a trigger.  

  107144. ** Check to see if it is OK to read this particular column.

  107145. **

  107146. ** If the auth function returns SQLITE_IGNORE, change the TK_COLUMN 

  107147. ** instruction into a TK_NULL.  If the auth function returns SQLITE_DENY,

  107148. ** then generate an error.

  107149. */

  107150. SQLITE_PRIVATE void sqlite3AuthRead(

  107151.   Parse *pParse,        /* The parser context */

  107152.   Expr *pExpr,          /* The expression to check authorization on */

  107153.   Schema *pSchema,      /* The schema of the expression */

  107154.   SrcList *pTabList     /* All table that pExpr might refer to */

  107155. ){

  107156.   sqlite3 *db = pParse->db;

  107157.   Table *pTab = 0;      /* The table being read */

  107158.   const char *zCol;     /* Name of the column of the table */

  107159.   int iSrc;             /* Index in pTabList->a[] of table being read */

  107160.   int iDb;              /* The index of the database the expression refers to */

  107161.   int iCol;             /* Index of column in table */

  107162. 

  107163.   assert( pExpr->op==TK_COLUMN || pExpr->op==TK_TRIGGER );

  107164.   assert( !IN_RENAME_OBJECT || db->xAuth==0 );

  107165.   if( db->xAuth==0 ) return;

  107166.   iDb = sqlite3SchemaToIndex(pParse->db, pSchema);

  107167.   if( iDb<0 ){

  107168.     /* An attempt to read a column out of a subquery or other

  107169.     ** temporary table. */

  107170.     return;

  107171.   }

  107172. 

  107173.   if( pExpr->op==TK_TRIGGER ){

  107174.     pTab = pParse->pTriggerTab;

  107175.   }else{

  107176.     assert( pTabList );

  107177.     for(iSrc=0; ALWAYS(iSrc<pTabList->nSrc); iSrc++){

  107178.       if( pExpr->iTable==pTabList->a[iSrc].iCursor ){

  107179.         pTab = pTabList->a[iSrc].pTab;

  107180.         break;

  107181.       }

  107182.     }

  107183.   }

  107184.   iCol = pExpr->iColumn;

  107185.   if( NEVER(pTab==0) ) return;

  107186. 

  107187.   if( iCol>=0 ){

  107188.     assert( iCol<pTab->nCol );

  107189.     zCol = pTab->aCol[iCol].zName;

  107190.   }else if( pTab->iPKey>=0 ){

  107191.     assert( pTab->iPKey<pTab->nCol );

  107192.     zCol = pTab->aCol[pTab->iPKey].zName;

  107193.   }else{

  107194.     zCol = "ROWID";

  107195.   }

  107196.   assert( iDb>=0 && iDb<db->nDb );

  107197.   if( SQLITE_IGNORE==sqlite3AuthReadCol(pParse, pTab->zName, zCol, iDb) ){

  107198.     pExpr->op = TK_NULL;

  107199.   }

  107200. }

  107201. 

  107202. /*

  107203. ** Do an authorization check using the code and arguments given.  Return

  107204. ** either SQLITE_OK (zero) or SQLITE_IGNORE or SQLITE_DENY.  If SQLITE_DENY

  107205. ** is returned, then the error count and error message in pParse are

  107206. ** modified appropriately.

  107207. */

  107208. SQLITE_PRIVATE int sqlite3AuthCheck(

  107209.   Parse *pParse,

  107210.   int code,

  107211.   const char *zArg1,

  107212.   const char *zArg2,

  107213.   const char *zArg3

  107214. ){

  107215.   sqlite3 *db = pParse->db;

  107216.   int rc;

  107217. 

  107218.   /* Don't do any authorization checks if the database is initialising

  107219.   ** or if the parser is being invoked from within sqlite3_declare_vtab.

  107220.   */

  107221.   assert( !IN_RENAME_OBJECT || db->xAuth==0 );

  107222.   if( db->init.busy || IN_SPECIAL_PARSE ){

  107223.     return SQLITE_OK;

  107224.   }

  107225. 

  107226.   if( db->xAuth==0 ){

  107227.     return SQLITE_OK;

  107228.   }

  107229. 

  107230.   /* EVIDENCE-OF: R-43249-19882 The third through sixth parameters to the

  107231.   ** callback are either NULL pointers or zero-terminated strings that

  107232.   ** contain additional details about the action to be authorized.

  107233.   **

  107234.   ** The following testcase() macros show that any of the 3rd through 6th

  107235.   ** parameters can be either NULL or a string. */

  107236.   testcase( zArg1==0 );

  107237.   testcase( zArg2==0 );

  107238.   testcase( zArg3==0 );

  107239.   testcase( pParse->zAuthContext==0 );

  107240. 

  107241.   rc = db->xAuth(db->pAuthArg, code, zArg1, zArg2, zArg3, pParse->zAuthContext

  107242. #ifdef SQLITE_USER_AUTHENTICATION

  107243.                  ,db->auth.zAuthUser

  107244. #endif

  107245.                 );

  107246.   if( rc==SQLITE_DENY ){

  107247.     sqlite3ErrorMsg(pParse, "not authorized");

  107248.     pParse->rc = SQLITE_AUTH;

  107249.   }else if( rc!=SQLITE_OK && rc!=SQLITE_IGNORE ){

  107250.     rc = SQLITE_DENY;

  107251.     sqliteAuthBadReturnCode(pParse);

  107252.   }

  107253.   return rc;

  107254. }

  107255. 

  107256. /*

  107257. ** Push an authorization context.  After this routine is called, the

  107258. ** zArg3 argument to authorization callbacks will be zContext until

  107259. ** popped.  Or if pParse==0, this routine is a no-op.

  107260. */

  107261. SQLITE_PRIVATE void sqlite3AuthContextPush(

  107262.   Parse *pParse,

  107263.   AuthContext *pContext, 

  107264.   const char *zContext

  107265. ){

  107266.   assert( pParse );

  107267.   pContext->pParse = pParse;

  107268.   pContext->zAuthContext = pParse->zAuthContext;

  107269.   pParse->zAuthContext = zContext;

  107270. }

  107271. 

  107272. /*

  107273. ** Pop an authorization context that was previously pushed

  107274. ** by sqlite3AuthContextPush

  107275. */

  107276. SQLITE_PRIVATE void sqlite3AuthContextPop(AuthContext *pContext){

  107277.   if( pContext->pParse ){

  107278.     pContext->pParse->zAuthContext = pContext->zAuthContext;

  107279.     pContext->pParse = 0;

  107280.   }

  107281. }

  107282. 

  107283. #endif /* SQLITE_OMIT_AUTHORIZATION */

  107284. 

  107285. /************** End of auth.c ************************************************/

  107286. /************** Begin file build.c *******************************************/

  107287. /*

  107288. ** 2001 September 15

  107289. **

  107290. ** The author disclaims copyright to this source code.  In place of

  107291. ** a legal notice, here is a blessing:

  107292. **

  107293. **    May you do good and not evil.

  107294. **    May you find forgiveness for yourself and forgive others.

  107295. **    May you share freely, never taking more than you give.

  107296. **

  107297. *************************************************************************

  107298. ** This file contains C code routines that are called by the SQLite parser

  107299. ** when syntax rules are reduced.  The routines in this file handle the

  107300. ** following kinds of SQL syntax:

  107301. **

  107302. **     CREATE TABLE

  107303. **     DROP TABLE

  107304. **     CREATE INDEX

  107305. **     DROP INDEX

  107306. **     creating ID lists

  107307. **     BEGIN TRANSACTION

  107308. **     COMMIT

  107309. **     ROLLBACK

  107310. */

  107311. /* #include "sqliteInt.h" */

  107312. 

  107313. #ifndef SQLITE_OMIT_SHARED_CACHE

  107314. /*

  107315. ** The TableLock structure is only used by the sqlite3TableLock() and

  107316. ** codeTableLocks() functions.

  107317. */

  107318. struct TableLock {

  107319.   int iDb;               /* The database containing the table to be locked */

  107320.   int iTab;              /* The root page of the table to be locked */

  107321.   u8 isWriteLock;        /* True for write lock.  False for a read lock */

  107322.   const char *zLockName; /* Name of the table */

  107323. };

  107324. 

  107325. /*

  107326. ** Record the fact that we want to lock a table at run-time.  

  107327. **

  107328. ** The table to be locked has root page iTab and is found in database iDb.

  107329. ** A read or a write lock can be taken depending on isWritelock.

  107330. **

  107331. ** This routine just records the fact that the lock is desired.  The

  107332. ** code to make the lock occur is generated by a later call to

  107333. ** codeTableLocks() which occurs during sqlite3FinishCoding().

  107334. */

  107335. SQLITE_PRIVATE void sqlite3TableLock(

  107336.   Parse *pParse,     /* Parsing context */

  107337.   int iDb,           /* Index of the database containing the table to lock */

  107338.   int iTab,          /* Root page number of the table to be locked */

  107339.   u8 isWriteLock,    /* True for a write lock */

  107340.   const char *zName  /* Name of the table to be locked */

  107341. ){

  107342.   Parse *pToplevel = sqlite3ParseToplevel(pParse);

  107343.   int i;

  107344.   int nBytes;

  107345.   TableLock *p;

  107346.   assert( iDb>=0 );

  107347. 

  107348.   if( iDb==1 ) return;

  107349.   if( !sqlite3BtreeSharable(pParse->db->aDb[iDb].pBt) ) return;

  107350.   for(i=0; i<pToplevel->nTableLock; i++){

  107351.     p = &pToplevel->aTableLock[i];

  107352.     if( p->iDb==iDb && p->iTab==iTab ){

  107353.       p->isWriteLock = (p->isWriteLock || isWriteLock);

  107354.       return;

  107355.     }

  107356.   }

  107357. 

  107358.   nBytes = sizeof(TableLock) * (pToplevel->nTableLock+1);

  107359.   pToplevel->aTableLock =

  107360.       sqlite3DbReallocOrFree(pToplevel->db, pToplevel->aTableLock, nBytes);

  107361.   if( pToplevel->aTableLock ){

  107362.     p = &pToplevel->aTableLock[pToplevel->nTableLock++];

  107363.     p->iDb = iDb;

  107364.     p->iTab = iTab;

  107365.     p->isWriteLock = isWriteLock;

  107366.     p->zLockName = zName;

  107367.   }else{

  107368.     pToplevel->nTableLock = 0;

  107369.     sqlite3OomFault(pToplevel->db);

  107370.   }

  107371. }

  107372. 

  107373. /*

  107374. ** Code an OP_TableLock instruction for each table locked by the

  107375. ** statement (configured by calls to sqlite3TableLock()).

  107376. */

  107377. static void codeTableLocks(Parse *pParse){

  107378.   int i;

  107379.   Vdbe *pVdbe; 

  107380. 

  107381.   pVdbe = sqlite3GetVdbe(pParse);

  107382.   assert( pVdbe!=0 ); /* sqlite3GetVdbe cannot fail: VDBE already allocated */

  107383. 

  107384.   for(i=0; i<pParse->nTableLock; i++){

  107385.     TableLock *p = &pParse->aTableLock[i];

  107386.     int p1 = p->iDb;

  107387.     sqlite3VdbeAddOp4(pVdbe, OP_TableLock, p1, p->iTab, p->isWriteLock,

  107388.                       p->zLockName, P4_STATIC);

  107389.   }

  107390. }

  107391. #else

  107392.   #define codeTableLocks(x)

  107393. #endif

  107394. 

  107395. /*

  107396. ** Return TRUE if the given yDbMask object is empty - if it contains no

  107397. ** 1 bits.  This routine is used by the DbMaskAllZero() and DbMaskNotZero()

  107398. ** macros when SQLITE_MAX_ATTACHED is greater than 30.

  107399. */

  107400. #if SQLITE_MAX_ATTACHED>30

  107401. SQLITE_PRIVATE int sqlite3DbMaskAllZero(yDbMask m){

  107402.   int i;

  107403.   for(i=0; i<sizeof(yDbMask); i++) if( m[i] ) return 0;

  107404.   return 1;

  107405. }

  107406. #endif

  107407. 

  107408. /*

  107409. ** This routine is called after a single SQL statement has been

  107410. ** parsed and a VDBE program to execute that statement has been

  107411. ** prepared.  This routine puts the finishing touches on the

  107412. ** VDBE program and resets the pParse structure for the next

  107413. ** parse.

  107414. **

  107415. ** Note that if an error occurred, it might be the case that

  107416. ** no VDBE code was generated.

  107417. */

  107418. SQLITE_PRIVATE void sqlite3FinishCoding(Parse *pParse){

  107419.   sqlite3 *db;

  107420.   Vdbe *v;

  107421. 

  107422.   assert( pParse->pToplevel==0 );

  107423.   db = pParse->db;

  107424.   if( pParse->nested ) return;

  107425.   if( db->mallocFailed || pParse->nErr ){

  107426.     if( pParse->rc==SQLITE_OK ) pParse->rc = SQLITE_ERROR;

  107427.     return;

  107428.   }

  107429. 

  107430.   /* Begin by generating some termination code at the end of the

  107431.   ** vdbe program

  107432.   */

  107433.   v = sqlite3GetVdbe(pParse);

  107434.   assert( !pParse->isMultiWrite 

  107435.        || sqlite3VdbeAssertMayAbort(v, pParse->mayAbort));

  107436.   if( v ){

  107437.     sqlite3VdbeAddOp0(v, OP_Halt);

  107438. 

  107439. #if SQLITE_USER_AUTHENTICATION

  107440.     if( pParse->nTableLock>0 && db->init.busy==0 ){

  107441.       sqlite3UserAuthInit(db);

  107442.       if( db->auth.authLevel<UAUTH_User ){

  107443.         sqlite3ErrorMsg(pParse, "user not authenticated");

  107444.         pParse->rc = SQLITE_AUTH_USER;

  107445.         return;

  107446.       }

  107447.     }

  107448. #endif

  107449. 

  107450.     /* The cookie mask contains one bit for each database file open.

  107451.     ** (Bit 0 is for main, bit 1 is for temp, and so forth.)  Bits are

  107452.     ** set for each database that is used.  Generate code to start a

  107453.     ** transaction on each used database and to verify the schema cookie

  107454.     ** on each used database.

  107455.     */

  107456.     if( db->mallocFailed==0 

  107457.      && (DbMaskNonZero(pParse->cookieMask) || pParse->pConstExpr)

  107458.     ){

  107459.       int iDb, i;

  107460.       assert( sqlite3VdbeGetOp(v, 0)->opcode==OP_Init );

  107461.       sqlite3VdbeJumpHere(v, 0);

  107462.       for(iDb=0; iDb<db->nDb; iDb++){

  107463.         Schema *pSchema;

  107464.         if( DbMaskTest(pParse->cookieMask, iDb)==0 ) continue;

  107465.         sqlite3VdbeUsesBtree(v, iDb);

  107466.         pSchema = db->aDb[iDb].pSchema;

  107467.         sqlite3VdbeAddOp4Int(v,

  107468.           OP_Transaction,                    /* Opcode */

  107469.           iDb,                               /* P1 */

  107470.           DbMaskTest(pParse->writeMask,iDb), /* P2 */

  107471.           pSchema->schema_cookie,            /* P3 */

  107472.           pSchema->iGeneration               /* P4 */

  107473.         );

  107474.         if( db->init.busy==0 ) sqlite3VdbeChangeP5(v, 1);

  107475.         VdbeComment((v,

  107476.               "usesStmtJournal=%d", pParse->mayAbort && pParse->isMultiWrite));

  107477.       }

  107478. #ifndef SQLITE_OMIT_VIRTUALTABLE

  107479.       for(i=0; i<pParse->nVtabLock; i++){

  107480.         char *vtab = (char *)sqlite3GetVTable(db, pParse->apVtabLock[i]);

  107481.         sqlite3VdbeAddOp4(v, OP_VBegin, 0, 0, 0, vtab, P4_VTAB);

  107482.       }

  107483.       pParse->nVtabLock = 0;

  107484. #endif

  107485. 

  107486.       /* Once all the cookies have been verified and transactions opened, 

  107487.       ** obtain the required table-locks. This is a no-op unless the 

  107488.       ** shared-cache feature is enabled.

  107489.       */

  107490.       codeTableLocks(pParse);

  107491. 

  107492.       /* Initialize any AUTOINCREMENT data structures required.

  107493.       */

  107494.       sqlite3AutoincrementBegin(pParse);

  107495. 

  107496.       /* Code constant expressions that where factored out of inner loops */

  107497.       if( pParse->pConstExpr ){

  107498.         ExprList *pEL = pParse->pConstExpr;

  107499.         pParse->okConstFactor = 0;

  107500.         for(i=0; i<pEL->nExpr; i++){

  107501.           sqlite3ExprCode(pParse, pEL->a[i].pExpr, pEL->a[i].u.iConstExprReg);

  107502.         }

  107503.       }

  107504. 

  107505.       /* Finally, jump back to the beginning of the executable code. */

  107506.       sqlite3VdbeGoto(v, 1);

  107507.     }

  107508.   }

  107509. 

  107510. 

  107511.   /* Get the VDBE program ready for execution

  107512.   */

  107513.   if( v && pParse->nErr==0 && !db->mallocFailed ){

  107514.     /* A minimum of one cursor is required if autoincrement is used

  107515.     *  See ticket [a696379c1f08866] */

  107516.     assert( pParse->pAinc==0 || pParse->nTab>0 );

  107517.     sqlite3VdbeMakeReady(v, pParse);

  107518.     pParse->rc = SQLITE_DONE;

  107519.   }else{

  107520.     pParse->rc = SQLITE_ERROR;

  107521.   }

  107522. }

  107523. 

  107524. /*

  107525. ** Run the parser and code generator recursively in order to generate

  107526. ** code for the SQL statement given onto the end of the pParse context

  107527. ** currently under construction.  When the parser is run recursively

  107528. ** this way, the final OP_Halt is not appended and other initialization

  107529. ** and finalization steps are omitted because those are handling by the

  107530. ** outermost parser.

  107531. **

  107532. ** Not everything is nestable.  This facility is designed to permit

  107533. ** INSERT, UPDATE, and DELETE operations against SQLITE_MASTER.  Use

  107534. ** care if you decide to try to use this routine for some other purposes.

  107535. */

  107536. SQLITE_PRIVATE void sqlite3NestedParse(Parse *pParse, const char *zFormat, ...){

  107537.   va_list ap;

  107538.   char *zSql;

  107539.   char *zErrMsg = 0;

  107540.   sqlite3 *db = pParse->db;

  107541.   char saveBuf[PARSE_TAIL_SZ];

  107542. 

  107543.   if( pParse->nErr ) return;

  107544.   assert( pParse->nested<10 );  /* Nesting should only be of limited depth */

  107545.   va_start(ap, zFormat);

  107546.   zSql = sqlite3VMPrintf(db, zFormat, ap);

  107547.   va_end(ap);

  107548.   if( zSql==0 ){

  107549.     /* This can result either from an OOM or because the formatted string

  107550.     ** exceeds SQLITE_LIMIT_LENGTH.  In the latter case, we need to set

  107551.     ** an error */

  107552.     if( !db->mallocFailed ) pParse->rc = SQLITE_TOOBIG;

  107553.     pParse->nErr++;

  107554.     return;

  107555.   }

  107556.   pParse->nested++;

  107557.   memcpy(saveBuf, PARSE_TAIL(pParse), PARSE_TAIL_SZ);

  107558.   memset(PARSE_TAIL(pParse), 0, PARSE_TAIL_SZ);

  107559.   sqlite3RunParser(pParse, zSql, &zErrMsg);

  107560.   sqlite3DbFree(db, zErrMsg);

  107561.   sqlite3DbFree(db, zSql);

  107562.   memcpy(PARSE_TAIL(pParse), saveBuf, PARSE_TAIL_SZ);

  107563.   pParse->nested--;

  107564. }

  107565. 

  107566. #if SQLITE_USER_AUTHENTICATION

  107567. /*

  107568. ** Return TRUE if zTable is the name of the system table that stores the

  107569. ** list of users and their access credentials.

  107570. */

  107571. SQLITE_PRIVATE int sqlite3UserAuthTable(const char *zTable){

  107572.   return sqlite3_stricmp(zTable, "sqlite_user")==0;

  107573. }

  107574. #endif

  107575. 

  107576. /*

  107577. ** Locate the in-memory structure that describes a particular database

  107578. ** table given the name of that table and (optionally) the name of the

  107579. ** database containing the table.  Return NULL if not found.

  107580. **

  107581. ** If zDatabase is 0, all databases are searched for the table and the

  107582. ** first matching table is returned.  (No checking for duplicate table

  107583. ** names is done.)  The search order is TEMP first, then MAIN, then any

  107584. ** auxiliary databases added using the ATTACH command.

  107585. **

  107586. ** See also sqlite3LocateTable().

  107587. */

  107588. SQLITE_PRIVATE Table *sqlite3FindTable(sqlite3 *db, const char *zName, const char *zDatabase){

  107589.   Table *p = 0;

  107590.   int i;

  107591. 

  107592.   /* All mutexes are required for schema access.  Make sure we hold them. */

  107593.   assert( zDatabase!=0 || sqlite3BtreeHoldsAllMutexes(db) );

  107594. #if SQLITE_USER_AUTHENTICATION

  107595.   /* Only the admin user is allowed to know that the sqlite_user table

  107596.   ** exists */

  107597.   if( db->auth.authLevel<UAUTH_Admin && sqlite3UserAuthTable(zName)!=0 ){

  107598.     return 0;

  107599.   }

  107600. #endif

  107601.   while(1){

  107602.     for(i=OMIT_TEMPDB; i<db->nDb; i++){

  107603.       int j = (i<2) ? i^1 : i;   /* Search TEMP before MAIN */

  107604.       if( zDatabase==0 || sqlite3StrICmp(zDatabase, db->aDb[j].zDbSName)==0 ){

  107605.         assert( sqlite3SchemaMutexHeld(db, j, 0) );

  107606.         p = sqlite3HashFind(&db->aDb[j].pSchema->tblHash, zName);

  107607.         if( p ) return p;

  107608.       }

  107609.     }

  107610.     /* Not found.  If the name we were looking for was temp.sqlite_master

  107611.     ** then change the name to sqlite_temp_master and try again. */

  107612.     if( sqlite3StrICmp(zName, MASTER_NAME)!=0 ) break;

  107613.     if( sqlite3_stricmp(zDatabase, db->aDb[1].zDbSName)!=0 ) break;

  107614.     zName = TEMP_MASTER_NAME;

  107615.   }

  107616.   return 0;

  107617. }

  107618. 

  107619. /*

  107620. ** Locate the in-memory structure that describes a particular database

  107621. ** table given the name of that table and (optionally) the name of the

  107622. ** database containing the table.  Return NULL if not found.  Also leave an

  107623. ** error message in pParse->zErrMsg.

  107624. **

  107625. ** The difference between this routine and sqlite3FindTable() is that this

  107626. ** routine leaves an error message in pParse->zErrMsg where

  107627. ** sqlite3FindTable() does not.

  107628. */

  107629. SQLITE_PRIVATE Table *sqlite3LocateTable(

  107630.   Parse *pParse,         /* context in which to report errors */

  107631.   u32 flags,             /* LOCATE_VIEW or LOCATE_NOERR */

  107632.   const char *zName,     /* Name of the table we are looking for */

  107633.   const char *zDbase     /* Name of the database.  Might be NULL */

  107634. ){

  107635.   Table *p;

  107636.   sqlite3 *db = pParse->db;

  107637. 

  107638.   /* Read the database schema. If an error occurs, leave an error message

  107639.   ** and code in pParse and return NULL. */

  107640.   if( (db->mDbFlags & DBFLAG_SchemaKnownOk)==0 

  107641.    && SQLITE_OK!=sqlite3ReadSchema(pParse)

  107642.   ){

  107643.     return 0;

  107644.   }

  107645. 

  107646.   p = sqlite3FindTable(db, zName, zDbase);

  107647.   if( p==0 ){

  107648. #ifndef SQLITE_OMIT_VIRTUALTABLE

  107649.     /* If zName is the not the name of a table in the schema created using

  107650.     ** CREATE, then check to see if it is the name of an virtual table that

  107651.     ** can be an eponymous virtual table. */

  107652.     if( pParse->disableVtab==0 ){

  107653.       Module *pMod = (Module*)sqlite3HashFind(&db->aModule, zName);

  107654.       if( pMod==0 && sqlite3_strnicmp(zName, "pragma_", 7)==0 ){

  107655.         pMod = sqlite3PragmaVtabRegister(db, zName);

  107656.       }

  107657.       if( pMod && sqlite3VtabEponymousTableInit(pParse, pMod) ){

  107658.         return pMod->pEpoTab;

  107659.       }

  107660.     }

  107661. #endif

  107662.     if( flags & LOCATE_NOERR ) return 0;

  107663.     pParse->checkSchema = 1;

  107664.   }else if( IsVirtual(p) && pParse->disableVtab ){

  107665.     p = 0;

  107666.   }

  107667. 

  107668.   if( p==0 ){

  107669.     const char *zMsg = flags & LOCATE_VIEW ? "no such view" : "no such table";

  107670.     if( zDbase ){

  107671.       sqlite3ErrorMsg(pParse, "%s: %s.%s", zMsg, zDbase, zName);

  107672.     }else{

  107673.       sqlite3ErrorMsg(pParse, "%s: %s", zMsg, zName);

  107674.     }

  107675.   }

  107676. 

  107677.   return p;

  107678. }

  107679. 

  107680. /*

  107681. ** Locate the table identified by *p.

  107682. **

  107683. ** This is a wrapper around sqlite3LocateTable(). The difference between

  107684. ** sqlite3LocateTable() and this function is that this function restricts

  107685. ** the search to schema (p->pSchema) if it is not NULL. p->pSchema may be

  107686. ** non-NULL if it is part of a view or trigger program definition. See

  107687. ** sqlite3FixSrcList() for details.

  107688. */

  107689. SQLITE_PRIVATE Table *sqlite3LocateTableItem(

  107690.   Parse *pParse, 

  107691.   u32 flags,

  107692.   struct SrcList_item *p

  107693. ){

  107694.   const char *zDb;

  107695.   assert( p->pSchema==0 || p->zDatabase==0 );

  107696.   if( p->pSchema ){

  107697.     int iDb = sqlite3SchemaToIndex(pParse->db, p->pSchema);

  107698.     zDb = pParse->db->aDb[iDb].zDbSName;

  107699.   }else{

  107700.     zDb = p->zDatabase;

  107701.   }

  107702.   return sqlite3LocateTable(pParse, flags, p->zName, zDb);

  107703. }

  107704. 

  107705. /*

  107706. ** Locate the in-memory structure that describes 

  107707. ** a particular index given the name of that index

  107708. ** and the name of the database that contains the index.

  107709. ** Return NULL if not found.

  107710. **

  107711. ** If zDatabase is 0, all databases are searched for the

  107712. ** table and the first matching index is returned.  (No checking

  107713. ** for duplicate index names is done.)  The search order is

  107714. ** TEMP first, then MAIN, then any auxiliary databases added

  107715. ** using the ATTACH command.

  107716. */

  107717. SQLITE_PRIVATE Index *sqlite3FindIndex(sqlite3 *db, const char *zName, const char *zDb){

  107718.   Index *p = 0;

  107719.   int i;

  107720.   /* All mutexes are required for schema access.  Make sure we hold them. */

  107721.   assert( zDb!=0 || sqlite3BtreeHoldsAllMutexes(db) );

  107722.   for(i=OMIT_TEMPDB; i<db->nDb; i++){

  107723.     int j = (i<2) ? i^1 : i;  /* Search TEMP before MAIN */

  107724.     Schema *pSchema = db->aDb[j].pSchema;

  107725.     assert( pSchema );

  107726.     if( zDb && sqlite3StrICmp(zDb, db->aDb[j].zDbSName) ) continue;

  107727.     assert( sqlite3SchemaMutexHeld(db, j, 0) );

  107728.     p = sqlite3HashFind(&pSchema->idxHash, zName);

  107729.     if( p ) break;

  107730.   }

  107731.   return p;

  107732. }

  107733. 

  107734. /*

  107735. ** Reclaim the memory used by an index

  107736. */

  107737. SQLITE_PRIVATE void sqlite3FreeIndex(sqlite3 *db, Index *p){

  107738. #ifndef SQLITE_OMIT_ANALYZE

  107739.   sqlite3DeleteIndexSamples(db, p);

  107740. #endif

  107741.   sqlite3ExprDelete(db, p->pPartIdxWhere);

  107742.   sqlite3ExprListDelete(db, p->aColExpr);

  107743.   sqlite3DbFree(db, p->zColAff);

  107744.   if( p->isResized ) sqlite3DbFree(db, (void *)p->azColl);

  107745. #ifdef SQLITE_ENABLE_STAT3_OR_STAT4

  107746.   sqlite3_free(p->aiRowEst);

  107747. #endif

  107748.   sqlite3DbFree(db, p);

  107749. }

  107750. 

  107751. /*

  107752. ** For the index called zIdxName which is found in the database iDb,

  107753. ** unlike that index from its Table then remove the index from

  107754. ** the index hash table and free all memory structures associated

  107755. ** with the index.

  107756. */

  107757. SQLITE_PRIVATE void sqlite3UnlinkAndDeleteIndex(sqlite3 *db, int iDb, const char *zIdxName){

  107758.   Index *pIndex;

  107759.   Hash *pHash;

  107760. 

  107761.   assert( sqlite3SchemaMutexHeld(db, iDb, 0) );

  107762.   pHash = &db->aDb[iDb].pSchema->idxHash;

  107763.   pIndex = sqlite3HashInsert(pHash, zIdxName, 0);

  107764.   if( ALWAYS(pIndex) ){

  107765.     if( pIndex->pTable->pIndex==pIndex ){

  107766.       pIndex->pTable->pIndex = pIndex->pNext;

  107767.     }else{

  107768.       Index *p;

  107769.       /* Justification of ALWAYS();  The index must be on the list of

  107770.       ** indices. */

  107771.       p = pIndex->pTable->pIndex;

  107772.       while( ALWAYS(p) && p->pNext!=pIndex ){ p = p->pNext; }

  107773.       if( ALWAYS(p && p->pNext==pIndex) ){

  107774.         p->pNext = pIndex->pNext;

  107775.       }

  107776.     }

  107777.     sqlite3FreeIndex(db, pIndex);

  107778.   }

  107779.   db->mDbFlags |= DBFLAG_SchemaChange;

  107780. }

  107781. 

  107782. /*

  107783. ** Look through the list of open database files in db->aDb[] and if

  107784. ** any have been closed, remove them from the list.  Reallocate the

  107785. ** db->aDb[] structure to a smaller size, if possible.

  107786. **

  107787. ** Entry 0 (the "main" database) and entry 1 (the "temp" database)

  107788. ** are never candidates for being collapsed.

  107789. */

  107790. SQLITE_PRIVATE void sqlite3CollapseDatabaseArray(sqlite3 *db){

  107791.   int i, j;

  107792.   for(i=j=2; i<db->nDb; i++){

  107793.     struct Db *pDb = &db->aDb[i];

  107794.     if( pDb->pBt==0 ){

  107795.       sqlite3DbFree(db, pDb->zDbSName);

  107796.       pDb->zDbSName = 0;

  107797.       continue;

  107798.     }

  107799.     if( j<i ){

  107800.       db->aDb[j] = db->aDb[i];

  107801.     }

  107802.     j++;

  107803.   }

  107804.   db->nDb = j;

  107805.   if( db->nDb<=2 && db->aDb!=db->aDbStatic ){

  107806.     memcpy(db->aDbStatic, db->aDb, 2*sizeof(db->aDb[0]));

  107807.     sqlite3DbFree(db, db->aDb);

  107808.     db->aDb = db->aDbStatic;

  107809.   }

  107810. }

  107811. 

  107812. /*

  107813. ** Reset the schema for the database at index iDb.  Also reset the

  107814. ** TEMP schema.  The reset is deferred if db->nSchemaLock is not zero.

  107815. ** Deferred resets may be run by calling with iDb<0.

  107816. */

  107817. SQLITE_PRIVATE void sqlite3ResetOneSchema(sqlite3 *db, int iDb){

  107818.   int i;

  107819.   assert( iDb<db->nDb );

  107820. 

  107821.   if( iDb>=0 ){

  107822.     assert( sqlite3SchemaMutexHeld(db, iDb, 0) );

  107823.     DbSetProperty(db, iDb, DB_ResetWanted);

  107824.     DbSetProperty(db, 1, DB_ResetWanted);

  107825.     db->mDbFlags &= ~DBFLAG_SchemaKnownOk;

  107826.   }

  107827. 

  107828.   if( db->nSchemaLock==0 ){

  107829.     for(i=0; i<db->nDb; i++){

  107830.       if( DbHasProperty(db, i, DB_ResetWanted) ){

  107831.         sqlite3SchemaClear(db->aDb[i].pSchema);

  107832.       }

  107833.     }

  107834.   }

  107835. }

  107836. 

  107837. /*

  107838. ** Erase all schema information from all attached databases (including

  107839. ** "main" and "temp") for a single database connection.

  107840. */

  107841. SQLITE_PRIVATE void sqlite3ResetAllSchemasOfConnection(sqlite3 *db){

  107842.   int i;

  107843.   sqlite3BtreeEnterAll(db);

  107844.   for(i=0; i<db->nDb; i++){

  107845.     Db *pDb = &db->aDb[i];

  107846.     if( pDb->pSchema ){

  107847.       if( db->nSchemaLock==0 ){

  107848.         sqlite3SchemaClear(pDb->pSchema);

  107849.       }else{

  107850.         DbSetProperty(db, i, DB_ResetWanted);

  107851.       }

  107852.     }

  107853.   }

  107854.   db->mDbFlags &= ~(DBFLAG_SchemaChange|DBFLAG_SchemaKnownOk);

  107855.   sqlite3VtabUnlockList(db);

  107856.   sqlite3BtreeLeaveAll(db);

  107857.   if( db->nSchemaLock==0 ){

  107858.     sqlite3CollapseDatabaseArray(db);

  107859.   }

  107860. }

  107861. 

  107862. /*

  107863. ** This routine is called when a commit occurs.

  107864. */

  107865. SQLITE_PRIVATE void sqlite3CommitInternalChanges(sqlite3 *db){

  107866.   db->mDbFlags &= ~DBFLAG_SchemaChange;

  107867. }

  107868. 

  107869. /*

  107870. ** Delete memory allocated for the column names of a table or view (the

  107871. ** Table.aCol[] array).

  107872. */

  107873. SQLITE_PRIVATE void sqlite3DeleteColumnNames(sqlite3 *db, Table *pTable){

  107874.   int i;

  107875.   Column *pCol;

  107876.   assert( pTable!=0 );

  107877.   if( (pCol = pTable->aCol)!=0 ){

  107878.     for(i=0; i<pTable->nCol; i++, pCol++){

  107879.       sqlite3DbFree(db, pCol->zName);

  107880.       sqlite3ExprDelete(db, pCol->pDflt);

  107881.       sqlite3DbFree(db, pCol->zColl);

  107882.     }

  107883.     sqlite3DbFree(db, pTable->aCol);

  107884.   }

  107885. }

  107886. 

  107887. /*

  107888. ** Remove the memory data structures associated with the given

  107889. ** Table.  No changes are made to disk by this routine.

  107890. **

  107891. ** This routine just deletes the data structure.  It does not unlink

  107892. ** the table data structure from the hash table.  But it does destroy

  107893. ** memory structures of the indices and foreign keys associated with 

  107894. ** the table.

  107895. **

  107896. ** The db parameter is optional.  It is needed if the Table object 

  107897. ** contains lookaside memory.  (Table objects in the schema do not use

  107898. ** lookaside memory, but some ephemeral Table objects do.)  Or the

  107899. ** db parameter can be used with db->pnBytesFreed to measure the memory

  107900. ** used by the Table object.

  107901. */

  107902. static void SQLITE_NOINLINE deleteTable(sqlite3 *db, Table *pTable){

  107903.   Index *pIndex, *pNext;

  107904. 

  107905. #ifdef SQLITE_DEBUG

  107906.   /* Record the number of outstanding lookaside allocations in schema Tables

  107907.   ** prior to doing any free() operations. Since schema Tables do not use

  107908.   ** lookaside, this number should not change. 

  107909.   **

  107910.   ** If malloc has already failed, it may be that it failed while allocating

  107911.   ** a Table object that was going to be marked ephemeral. So do not check

  107912.   ** that no lookaside memory is used in this case either. */

  107913.   int nLookaside = 0;

  107914.   if( db && !db->mallocFailed && (pTable->tabFlags & TF_Ephemeral)==0 ){

  107915.     nLookaside = sqlite3LookasideUsed(db, 0);

  107916.   }

  107917. #endif

  107918. 

  107919.   /* Delete all indices associated with this table. */

  107920.   for(pIndex = pTable->pIndex; pIndex; pIndex=pNext){

  107921.     pNext = pIndex->pNext;

  107922.     assert( pIndex->pSchema==pTable->pSchema

  107923.          || (IsVirtual(pTable) && pIndex->idxType!=SQLITE_IDXTYPE_APPDEF) );

  107924.     if( (db==0 || db->pnBytesFreed==0) && !IsVirtual(pTable) ){

  107925.       char *zName = pIndex->zName; 

  107926.       TESTONLY ( Index *pOld = ) sqlite3HashInsert(

  107927.          &pIndex->pSchema->idxHash, zName, 0

  107928.       );

  107929.       assert( db==0 || sqlite3SchemaMutexHeld(db, 0, pIndex->pSchema) );

  107930.       assert( pOld==pIndex || pOld==0 );

  107931.     }

  107932.     sqlite3FreeIndex(db, pIndex);

  107933.   }

  107934. 

  107935.   /* Delete any foreign keys attached to this table. */

  107936.   sqlite3FkDelete(db, pTable);

  107937. 

  107938.   /* Delete the Table structure itself.

  107939.   */

  107940.   sqlite3DeleteColumnNames(db, pTable);

  107941.   sqlite3DbFree(db, pTable->zName);

  107942.   sqlite3DbFree(db, pTable->zColAff);

  107943.   sqlite3SelectDelete(db, pTable->pSelect);

  107944.   sqlite3ExprListDelete(db, pTable->pCheck);

  107945. #ifndef SQLITE_OMIT_VIRTUALTABLE

  107946.   sqlite3VtabClear(db, pTable);

  107947. #endif

  107948.   sqlite3DbFree(db, pTable);

  107949. 

  107950.   /* Verify that no lookaside memory was used by schema tables */

  107951.   assert( nLookaside==0 || nLookaside==sqlite3LookasideUsed(db,0) );

  107952. }

  107953. SQLITE_PRIVATE void sqlite3DeleteTable(sqlite3 *db, Table *pTable){

  107954.   /* Do not delete the table until the reference count reaches zero. */

  107955.   if( !pTable ) return;

  107956.   if( ((!db || db->pnBytesFreed==0) && (--pTable->nTabRef)>0) ) return;

  107957.   deleteTable(db, pTable);

  107958. }

  107959. 

  107960. 

  107961. /*

  107962. ** Unlink the given table from the hash tables and the delete the

  107963. ** table structure with all its indices and foreign keys.

  107964. */

  107965. SQLITE_PRIVATE void sqlite3UnlinkAndDeleteTable(sqlite3 *db, int iDb, const char *zTabName){

  107966.   Table *p;

  107967.   Db *pDb;

  107968. 

  107969.   assert( db!=0 );

  107970.   assert( iDb>=0 && iDb<db->nDb );

  107971.   assert( zTabName );

  107972.   assert( sqlite3SchemaMutexHeld(db, iDb, 0) );

  107973.   testcase( zTabName[0]==0 );  /* Zero-length table names are allowed */

  107974.   pDb = &db->aDb[iDb];

  107975.   p = sqlite3HashInsert(&pDb->pSchema->tblHash, zTabName, 0);

  107976.   sqlite3DeleteTable(db, p);

  107977.   db->mDbFlags |= DBFLAG_SchemaChange;

  107978. }

  107979. 

  107980. /*

  107981. ** Given a token, return a string that consists of the text of that

  107982. ** token.  Space to hold the returned string

  107983. ** is obtained from sqliteMalloc() and must be freed by the calling

  107984. ** function.

  107985. **

  107986. ** Any quotation marks (ex:  "name", 'name', [name], or `name`) that

  107987. ** surround the body of the token are removed.

  107988. **

  107989. ** Tokens are often just pointers into the original SQL text and so

  107990. ** are not \000 terminated and are not persistent.  The returned string

  107991. ** is \000 terminated and is persistent.

  107992. */

  107993. SQLITE_PRIVATE char *sqlite3NameFromToken(sqlite3 *db, Token *pName){

  107994.   char *zName;

  107995.   if( pName ){

  107996.     zName = sqlite3DbStrNDup(db, (char*)pName->z, pName->n);

  107997.     sqlite3Dequote(zName);

  107998.   }else{

  107999.     zName = 0;

  108000.   }

  108001.   return zName;

  108002. }

  108003. 

  108004. /*

  108005. ** Open the sqlite_master table stored in database number iDb for

  108006. ** writing. The table is opened using cursor 0.

  108007. */

  108008. SQLITE_PRIVATE void sqlite3OpenMasterTable(Parse *p, int iDb){

  108009.   Vdbe *v = sqlite3GetVdbe(p);

  108010.   sqlite3TableLock(p, iDb, MASTER_ROOT, 1, MASTER_NAME);

  108011.   sqlite3VdbeAddOp4Int(v, OP_OpenWrite, 0, MASTER_ROOT, iDb, 5);

  108012.   if( p->nTab==0 ){

  108013.     p->nTab = 1;

  108014.   }

  108015. }

  108016. 

  108017. /*

  108018. ** Parameter zName points to a nul-terminated buffer containing the name

  108019. ** of a database ("main", "temp" or the name of an attached db). This

  108020. ** function returns the index of the named database in db->aDb[], or

  108021. ** -1 if the named db cannot be found.

  108022. */

  108023. SQLITE_PRIVATE int sqlite3FindDbName(sqlite3 *db, const char *zName){

  108024.   int i = -1;         /* Database number */

  108025.   if( zName ){

  108026.     Db *pDb;

  108027.     for(i=(db->nDb-1), pDb=&db->aDb[i]; i>=0; i--, pDb--){

  108028.       if( 0==sqlite3_stricmp(pDb->zDbSName, zName) ) break;

  108029.       /* "main" is always an acceptable alias for the primary database

  108030.       ** even if it has been renamed using SQLITE_DBCONFIG_MAINDBNAME. */

  108031.       if( i==0 && 0==sqlite3_stricmp("main", zName) ) break;

  108032.     }

  108033.   }

  108034.   return i;

  108035. }

  108036. 

  108037. /*

  108038. ** The token *pName contains the name of a database (either "main" or

  108039. ** "temp" or the name of an attached db). This routine returns the

  108040. ** index of the named database in db->aDb[], or -1 if the named db 

  108041. ** does not exist.

  108042. */

  108043. SQLITE_PRIVATE int sqlite3FindDb(sqlite3 *db, Token *pName){

  108044.   int i;                               /* Database number */

  108045.   char *zName;                         /* Name we are searching for */

  108046.   zName = sqlite3NameFromToken(db, pName);

  108047.   i = sqlite3FindDbName(db, zName);

  108048.   sqlite3DbFree(db, zName);

  108049.   return i;

  108050. }

  108051. 

  108052. /* The table or view or trigger name is passed to this routine via tokens

  108053. ** pName1 and pName2. If the table name was fully qualified, for example:

  108054. **

  108055. ** CREATE TABLE xxx.yyy (...);

  108056. ** 

  108057. ** Then pName1 is set to "xxx" and pName2 "yyy". On the other hand if

  108058. ** the table name is not fully qualified, i.e.:

  108059. **

  108060. ** CREATE TABLE yyy(...);

  108061. **

  108062. ** Then pName1 is set to "yyy" and pName2 is "".

  108063. **

  108064. ** This routine sets the *ppUnqual pointer to point at the token (pName1 or

  108065. ** pName2) that stores the unqualified table name.  The index of the

  108066. ** database "xxx" is returned.

  108067. */

  108068. SQLITE_PRIVATE int sqlite3TwoPartName(

  108069.   Parse *pParse,      /* Parsing and code generating context */

  108070.   Token *pName1,      /* The "xxx" in the name "xxx.yyy" or "xxx" */

  108071.   Token *pName2,      /* The "yyy" in the name "xxx.yyy" */

  108072.   Token **pUnqual     /* Write the unqualified object name here */

  108073. ){

  108074.   int iDb;                    /* Database holding the object */

  108075.   sqlite3 *db = pParse->db;

  108076. 

  108077.   assert( pName2!=0 );

  108078.   if( pName2->n>0 ){

  108079.     if( db->init.busy ) {

  108080.       sqlite3ErrorMsg(pParse, "corrupt database");

  108081.       return -1;

  108082.     }

  108083.     *pUnqual = pName2;

  108084.     iDb = sqlite3FindDb(db, pName1);

  108085.     if( iDb<0 ){

  108086.       sqlite3ErrorMsg(pParse, "unknown database %T", pName1);

  108087.       return -1;

  108088.     }

  108089.   }else{

  108090.     assert( db->init.iDb==0 || db->init.busy || IN_RENAME_OBJECT

  108091.              || (db->mDbFlags & DBFLAG_Vacuum)!=0);

  108092.     iDb = db->init.iDb;

  108093.     *pUnqual = pName1;

  108094.   }

  108095.   return iDb;

  108096. }

  108097. 

  108098. /*

  108099. ** True if PRAGMA writable_schema is ON

  108100. */

  108101. SQLITE_PRIVATE int sqlite3WritableSchema(sqlite3 *db){

  108102.   testcase( (db->flags&(SQLITE_WriteSchema|SQLITE_Defensive))==0 );

  108103.   testcase( (db->flags&(SQLITE_WriteSchema|SQLITE_Defensive))==

  108104.                SQLITE_WriteSchema );

  108105.   testcase( (db->flags&(SQLITE_WriteSchema|SQLITE_Defensive))==

  108106.                SQLITE_Defensive );

  108107.   testcase( (db->flags&(SQLITE_WriteSchema|SQLITE_Defensive))==

  108108.                (SQLITE_WriteSchema|SQLITE_Defensive) );

  108109.   return (db->flags&(SQLITE_WriteSchema|SQLITE_Defensive))==SQLITE_WriteSchema;

  108110. }

  108111. 

  108112. /*

  108113. ** This routine is used to check if the UTF-8 string zName is a legal

  108114. ** unqualified name for a new schema object (table, index, view or

  108115. ** trigger). All names are legal except those that begin with the string

  108116. ** "sqlite_" (in upper, lower or mixed case). This portion of the namespace

  108117. ** is reserved for internal use.

  108118. */

  108119. SQLITE_PRIVATE int sqlite3CheckObjectName(Parse *pParse, const char *zName){

  108120.   if( !pParse->db->init.busy && pParse->nested==0 

  108121.           && sqlite3WritableSchema(pParse->db)==0

  108122.           && 0==sqlite3StrNICmp(zName, "sqlite_", 7) ){

  108123.     sqlite3ErrorMsg(pParse, "object name reserved for internal use: %s", zName);

  108124.     return SQLITE_ERROR;

  108125.   }

  108126.   return SQLITE_OK;

  108127. }

  108128. 

  108129. /*

  108130. ** Return the PRIMARY KEY index of a table

  108131. */

  108132. SQLITE_PRIVATE Index *sqlite3PrimaryKeyIndex(Table *pTab){

  108133.   Index *p;

  108134.   for(p=pTab->pIndex; p && !IsPrimaryKeyIndex(p); p=p->pNext){}

  108135.   return p;

  108136. }

  108137. 

  108138. /*

  108139. ** Return the column of index pIdx that corresponds to table

  108140. ** column iCol.  Return -1 if not found.

  108141. */

  108142. SQLITE_PRIVATE i16 sqlite3ColumnOfIndex(Index *pIdx, i16 iCol){

  108143.   int i;

  108144.   for(i=0; i<pIdx->nColumn; i++){

  108145.     if( iCol==pIdx->aiColumn[i] ) return i;

  108146.   }

  108147.   return -1;

  108148. }

  108149. 

  108150. /*

  108151. ** Begin constructing a new table representation in memory.  This is

  108152. ** the first of several action routines that get called in response

  108153. ** to a CREATE TABLE statement.  In particular, this routine is called

  108154. ** after seeing tokens "CREATE" and "TABLE" and the table name. The isTemp

  108155. ** flag is true if the table should be stored in the auxiliary database

  108156. ** file instead of in the main database file.  This is normally the case

  108157. ** when the "TEMP" or "TEMPORARY" keyword occurs in between

  108158. ** CREATE and TABLE.

  108159. **

  108160. ** The new table record is initialized and put in pParse->pNewTable.

  108161. ** As more of the CREATE TABLE statement is parsed, additional action

  108162. ** routines will be called to add more information to this record.

  108163. ** At the end of the CREATE TABLE statement, the sqlite3EndTable() routine

  108164. ** is called to complete the construction of the new table record.

  108165. */

  108166. SQLITE_PRIVATE void sqlite3StartTable(

  108167.   Parse *pParse,   /* Parser context */

  108168.   Token *pName1,   /* First part of the name of the table or view */

  108169.   Token *pName2,   /* Second part of the name of the table or view */

  108170.   int isTemp,      /* True if this is a TEMP table */

  108171.   int isView,      /* True if this is a VIEW */

  108172.   int isVirtual,   /* True if this is a VIRTUAL table */

  108173.   int noErr        /* Do nothing if table already exists */

  108174. ){

  108175.   Table *pTable;

  108176.   char *zName = 0; /* The name of the new table */

  108177.   sqlite3 *db = pParse->db;

  108178.   Vdbe *v;

  108179.   int iDb;         /* Database number to create the table in */

  108180.   Token *pName;    /* Unqualified name of the table to create */

  108181. 

  108182.   if( db->init.busy && db->init.newTnum==1 ){

  108183.     /* Special case:  Parsing the sqlite_master or sqlite_temp_master schema */

  108184.     iDb = db->init.iDb;

  108185.     zName = sqlite3DbStrDup(db, SCHEMA_TABLE(iDb));

  108186.     pName = pName1;

  108187.   }else{

  108188.     /* The common case */

  108189.     iDb = sqlite3TwoPartName(pParse, pName1, pName2, &pName);

  108190.     if( iDb<0 ) return;

  108191.     if( !OMIT_TEMPDB && isTemp && pName2->n>0 && iDb!=1 ){

  108192.       /* If creating a temp table, the name may not be qualified. Unless 

  108193.       ** the database name is "temp" anyway.  */

  108194.       sqlite3ErrorMsg(pParse, "temporary table name must be unqualified");

  108195.       return;

  108196.     }

  108197.     if( !OMIT_TEMPDB && isTemp ) iDb = 1;

  108198.     zName = sqlite3NameFromToken(db, pName);

  108199.     if( IN_RENAME_OBJECT ){

  108200.       sqlite3RenameTokenMap(pParse, (void*)zName, pName);

  108201.     }

  108202.   }

  108203.   pParse->sNameToken = *pName;

  108204.   if( zName==0 ) return;

  108205.   if( SQLITE_OK!=sqlite3CheckObjectName(pParse, zName) ){

  108206.     goto begin_table_error;

  108207.   }

  108208.   if( db->init.iDb==1 ) isTemp = 1;

  108209. #ifndef SQLITE_OMIT_AUTHORIZATION

  108210.   assert( isTemp==0 || isTemp==1 );

  108211.   assert( isView==0 || isView==1 );

  108212.   {

  108213.     static const u8 aCode[] = {

  108214.        SQLITE_CREATE_TABLE,

  108215.        SQLITE_CREATE_TEMP_TABLE,

  108216.        SQLITE_CREATE_VIEW,

  108217.        SQLITE_CREATE_TEMP_VIEW

  108218.     };

  108219.     char *zDb = db->aDb[iDb].zDbSName;

  108220.     if( sqlite3AuthCheck(pParse, SQLITE_INSERT, SCHEMA_TABLE(isTemp), 0, zDb) ){

  108221.       goto begin_table_error;

  108222.     }

  108223.     if( !isVirtual && sqlite3AuthCheck(pParse, (int)aCode[isTemp+2*isView],

  108224.                                        zName, 0, zDb) ){

  108225.       goto begin_table_error;

  108226.     }

  108227.   }

  108228. #endif

  108229. 

  108230.   /* Make sure the new table name does not collide with an existing

  108231.   ** index or table name in the same database.  Issue an error message if

  108232.   ** it does. The exception is if the statement being parsed was passed

  108233.   ** to an sqlite3_declare_vtab() call. In that case only the column names

  108234.   ** and types will be used, so there is no need to test for namespace

  108235.   ** collisions.

  108236.   */

  108237.   if( !IN_SPECIAL_PARSE ){

  108238.     char *zDb = db->aDb[iDb].zDbSName;

  108239.     if( SQLITE_OK!=sqlite3ReadSchema(pParse) ){

  108240.       goto begin_table_error;

  108241.     }

  108242.     pTable = sqlite3FindTable(db, zName, zDb);

  108243.     if( pTable ){

  108244.       if( !noErr ){

  108245.         sqlite3ErrorMsg(pParse, "table %T already exists", pName);

  108246.       }else{

  108247.         assert( !db->init.busy || CORRUPT_DB );

  108248.         sqlite3CodeVerifySchema(pParse, iDb);

  108249.       }

  108250.       goto begin_table_error;

  108251.     }

  108252.     if( sqlite3FindIndex(db, zName, zDb)!=0 ){

  108253.       sqlite3ErrorMsg(pParse, "there is already an index named %s", zName);

  108254.       goto begin_table_error;

  108255.     }

  108256.   }

  108257. 

  108258.   pTable = sqlite3DbMallocZero(db, sizeof(Table));

  108259.   if( pTable==0 ){

  108260.     assert( db->mallocFailed );

  108261.     pParse->rc = SQLITE_NOMEM_BKPT;

  108262.     pParse->nErr++;

  108263.     goto begin_table_error;

  108264.   }

  108265.   pTable->zName = zName;

  108266.   pTable->iPKey = -1;

  108267.   pTable->pSchema = db->aDb[iDb].pSchema;

  108268.   pTable->nTabRef = 1;

  108269. #ifdef SQLITE_DEFAULT_ROWEST

  108270.   pTable->nRowLogEst = sqlite3LogEst(SQLITE_DEFAULT_ROWEST);

  108271. #else

  108272.   pTable->nRowLogEst = 200; assert( 200==sqlite3LogEst(1048576) );

  108273. #endif

  108274.   assert( pParse->pNewTable==0 );

  108275.   pParse->pNewTable = pTable;

  108276. 

  108277.   /* If this is the magic sqlite_sequence table used by autoincrement,

  108278.   ** then record a pointer to this table in the main database structure

  108279.   ** so that INSERT can find the table easily.

  108280.   */

  108281. #ifndef SQLITE_OMIT_AUTOINCREMENT

  108282.   if( !pParse->nested && strcmp(zName, "sqlite_sequence")==0 ){

  108283.     assert( sqlite3SchemaMutexHeld(db, iDb, 0) );

  108284.     pTable->pSchema->pSeqTab = pTable;

  108285.   }

  108286. #endif

  108287. 

  108288.   /* Begin generating the code that will insert the table record into

  108289.   ** the SQLITE_MASTER table.  Note in particular that we must go ahead

  108290.   ** and allocate the record number for the table entry now.  Before any

  108291.   ** PRIMARY KEY or UNIQUE keywords are parsed.  Those keywords will cause

  108292.   ** indices to be created and the table record must come before the 

  108293.   ** indices.  Hence, the record number for the table must be allocated

  108294.   ** now.

  108295.   */

  108296.   if( !db->init.busy && (v = sqlite3GetVdbe(pParse))!=0 ){

  108297.     int addr1;

  108298.     int fileFormat;

  108299.     int reg1, reg2, reg3;

  108300.     /* nullRow[] is an OP_Record encoding of a row containing 5 NULLs */

  108301.     static const char nullRow[] = { 6, 0, 0, 0, 0, 0 };

  108302.     sqlite3BeginWriteOperation(pParse, 1, iDb);

  108303. 

  108304. #ifndef SQLITE_OMIT_VIRTUALTABLE

  108305.     if( isVirtual ){

  108306.       sqlite3VdbeAddOp0(v, OP_VBegin);

  108307.     }

  108308. #endif

  108309. 

  108310.     /* If the file format and encoding in the database have not been set, 

  108311.     ** set them now.

  108312.     */

  108313.     reg1 = pParse->regRowid = ++pParse->nMem;

  108314.     reg2 = pParse->regRoot = ++pParse->nMem;

  108315.     reg3 = ++pParse->nMem;

  108316.     sqlite3VdbeAddOp3(v, OP_ReadCookie, iDb, reg3, BTREE_FILE_FORMAT);

  108317.     sqlite3VdbeUsesBtree(v, iDb);

  108318.     addr1 = sqlite3VdbeAddOp1(v, OP_If, reg3); VdbeCoverage(v);

  108319.     fileFormat = (db->flags & SQLITE_LegacyFileFmt)!=0 ?

  108320.                   1 : SQLITE_MAX_FILE_FORMAT;

  108321.     sqlite3VdbeAddOp3(v, OP_SetCookie, iDb, BTREE_FILE_FORMAT, fileFormat);

  108322.     sqlite3VdbeAddOp3(v, OP_SetCookie, iDb, BTREE_TEXT_ENCODING, ENC(db));

  108323.     sqlite3VdbeJumpHere(v, addr1);

  108324. 

  108325.     /* This just creates a place-holder record in the sqlite_master table.

  108326.     ** The record created does not contain anything yet.  It will be replaced

  108327.     ** by the real entry in code generated at sqlite3EndTable().

  108328.     **

  108329.     ** The rowid for the new entry is left in register pParse->regRowid.

  108330.     ** The root page number of the new table is left in reg pParse->regRoot.

  108331.     ** The rowid and root page number values are needed by the code that

  108332.     ** sqlite3EndTable will generate.

  108333.     */

  108334. #if !defined(SQLITE_OMIT_VIEW) || !defined(SQLITE_OMIT_VIRTUALTABLE)

  108335.     if( isView || isVirtual ){

  108336.       sqlite3VdbeAddOp2(v, OP_Integer, 0, reg2);

  108337.     }else

  108338. #endif

  108339.     {

  108340.       pParse->addrCrTab =

  108341.          sqlite3VdbeAddOp3(v, OP_CreateBtree, iDb, reg2, BTREE_INTKEY);

  108342.     }

  108343.     sqlite3OpenMasterTable(pParse, iDb);

  108344.     sqlite3VdbeAddOp2(v, OP_NewRowid, 0, reg1);

  108345.     sqlite3VdbeAddOp4(v, OP_Blob, 6, reg3, 0, nullRow, P4_STATIC);

  108346.     sqlite3VdbeAddOp3(v, OP_Insert, 0, reg3, reg1);

  108347.     sqlite3VdbeChangeP5(v, OPFLAG_APPEND);

  108348.     sqlite3VdbeAddOp0(v, OP_Close);

  108349.   }

  108350. 

  108351.   /* Normal (non-error) return. */

  108352.   return;

  108353. 

  108354.   /* If an error occurs, we jump here */

  108355. begin_table_error:

  108356.   sqlite3DbFree(db, zName);

  108357.   return;

  108358. }

  108359. 

  108360. /* Set properties of a table column based on the (magical)

  108361. ** name of the column.

  108362. */

  108363. #if SQLITE_ENABLE_HIDDEN_COLUMNS

  108364. SQLITE_PRIVATE void sqlite3ColumnPropertiesFromName(Table *pTab, Column *pCol){

  108365.   if( sqlite3_strnicmp(pCol->zName, "__hidden__", 10)==0 ){

  108366.     pCol->colFlags |= COLFLAG_HIDDEN;

  108367.   }else if( pTab && pCol!=pTab->aCol && (pCol[-1].colFlags & COLFLAG_HIDDEN) ){

  108368.     pTab->tabFlags |= TF_OOOHidden;

  108369.   }

  108370. }

  108371. #endif

  108372. 

  108373. 

  108374. /*

  108375. ** Add a new column to the table currently being constructed.

  108376. **

  108377. ** The parser calls this routine once for each column declaration

  108378. ** in a CREATE TABLE statement.  sqlite3StartTable() gets called

  108379. ** first to get things going.  Then this routine is called for each

  108380. ** column.

  108381. */

  108382. SQLITE_PRIVATE void sqlite3AddColumn(Parse *pParse, Token *pName, Token *pType){

  108383.   Table *p;

  108384.   int i;

  108385.   char *z;

  108386.   char *zType;

  108387.   Column *pCol;

  108388.   sqlite3 *db = pParse->db;

  108389.   if( (p = pParse->pNewTable)==0 ) return;

  108390.   if( p->nCol+1>db->aLimit[SQLITE_LIMIT_COLUMN] ){

  108391.     sqlite3ErrorMsg(pParse, "too many columns on %s", p->zName);

  108392.     return;

  108393.   }

  108394.   z = sqlite3DbMallocRaw(db, pName->n + pType->n + 2);

  108395.   if( z==0 ) return;

  108396.   if( IN_RENAME_OBJECT ) sqlite3RenameTokenMap(pParse, (void*)z, pName);

  108397.   memcpy(z, pName->z, pName->n);

  108398.   z[pName->n] = 0;

  108399.   sqlite3Dequote(z);

  108400.   for(i=0; i<p->nCol; i++){

  108401.     if( sqlite3_stricmp(z, p->aCol[i].zName)==0 ){

  108402.       sqlite3ErrorMsg(pParse, "duplicate column name: %s", z);

  108403.       sqlite3DbFree(db, z);

  108404.       return;

  108405.     }

  108406.   }

  108407.   if( (p->nCol & 0x7)==0 ){

  108408.     Column *aNew;

  108409.     aNew = sqlite3DbRealloc(db,p->aCol,(p->nCol+8)*sizeof(p->aCol[0]));

  108410.     if( aNew==0 ){

  108411.       sqlite3DbFree(db, z);

  108412.       return;

  108413.     }

  108414.     p->aCol = aNew;

  108415.   }

  108416.   pCol = &p->aCol[p->nCol];

  108417.   memset(pCol, 0, sizeof(p->aCol[0]));

  108418.   pCol->zName = z;

  108419.   sqlite3ColumnPropertiesFromName(p, pCol);

  108420.  

  108421.   if( pType->n==0 ){

  108422.     /* If there is no type specified, columns have the default affinity

  108423.     ** 'BLOB' with a default size of 4 bytes. */

  108424.     pCol->affinity = SQLITE_AFF_BLOB;

  108425.     pCol->szEst = 1;

  108426. #ifdef SQLITE_ENABLE_SORTER_REFERENCES

  108427.     if( 4>=sqlite3GlobalConfig.szSorterRef ){

  108428.       pCol->colFlags |= COLFLAG_SORTERREF;

  108429.     }

  108430. #endif

  108431.   }else{

  108432.     zType = z + sqlite3Strlen30(z) + 1;

  108433.     memcpy(zType, pType->z, pType->n);

  108434.     zType[pType->n] = 0;

  108435.     sqlite3Dequote(zType);

  108436.     pCol->affinity = sqlite3AffinityType(zType, pCol);

  108437.     pCol->colFlags |= COLFLAG_HASTYPE;

  108438.   }

  108439.   p->nCol++;

  108440.   pParse->constraintName.n = 0;

  108441. }

  108442. 

  108443. /*

  108444. ** This routine is called by the parser while in the middle of

  108445. ** parsing a CREATE TABLE statement.  A "NOT NULL" constraint has

  108446. ** been seen on a column.  This routine sets the notNull flag on

  108447. ** the column currently under construction.

  108448. */

  108449. SQLITE_PRIVATE void sqlite3AddNotNull(Parse *pParse, int onError){

  108450.   Table *p;

  108451.   Column *pCol;

  108452.   p = pParse->pNewTable;

  108453.   if( p==0 || NEVER(p->nCol<1) ) return;

  108454.   pCol = &p->aCol[p->nCol-1];

  108455.   pCol->notNull = (u8)onError;

  108456.   p->tabFlags |= TF_HasNotNull;

  108457. 

  108458.   /* Set the uniqNotNull flag on any UNIQUE or PK indexes already created

  108459.   ** on this column.  */

  108460.   if( pCol->colFlags & COLFLAG_UNIQUE ){

  108461.     Index *pIdx;

  108462.     for(pIdx=p->pIndex; pIdx; pIdx=pIdx->pNext){

  108463.       assert( pIdx->nKeyCol==1 && pIdx->onError!=OE_None );

  108464.       if( pIdx->aiColumn[0]==p->nCol-1 ){

  108465.         pIdx->uniqNotNull = 1;

  108466.       }

  108467.     }

  108468.   }

  108469. }

  108470. 

  108471. /*

  108472. ** Scan the column type name zType (length nType) and return the

  108473. ** associated affinity type.

  108474. **

  108475. ** This routine does a case-independent search of zType for the 

  108476. ** substrings in the following table. If one of the substrings is

  108477. ** found, the corresponding affinity is returned. If zType contains

  108478. ** more than one of the substrings, entries toward the top of 

  108479. ** the table take priority. For example, if zType is 'BLOBINT', 

  108480. ** SQLITE_AFF_INTEGER is returned.

  108481. **

  108482. ** Substring     | Affinity

  108483. ** --------------------------------

  108484. ** 'INT'         | SQLITE_AFF_INTEGER

  108485. ** 'CHAR'        | SQLITE_AFF_TEXT

  108486. ** 'CLOB'        | SQLITE_AFF_TEXT

  108487. ** 'TEXT'        | SQLITE_AFF_TEXT

  108488. ** 'BLOB'        | SQLITE_AFF_BLOB

  108489. ** 'REAL'        | SQLITE_AFF_REAL

  108490. ** 'FLOA'        | SQLITE_AFF_REAL

  108491. ** 'DOUB'        | SQLITE_AFF_REAL

  108492. **

  108493. ** If none of the substrings in the above table are found,

  108494. ** SQLITE_AFF_NUMERIC is returned.

  108495. */

  108496. SQLITE_PRIVATE char sqlite3AffinityType(const char *zIn, Column *pCol){

  108497.   u32 h = 0;

  108498.   char aff = SQLITE_AFF_NUMERIC;

  108499.   const char *zChar = 0;

  108500. 

  108501.   assert( zIn!=0 );

  108502.   while( zIn[0] ){

  108503.     h = (h<<8) + sqlite3UpperToLower[(*zIn)&0xff];

  108504.     zIn++;

  108505.     if( h==(('c'<<24)+('h'<<16)+('a'<<8)+'r') ){             /* CHAR */

  108506.       aff = SQLITE_AFF_TEXT;

  108507.       zChar = zIn;

  108508.     }else if( h==(('c'<<24)+('l'<<16)+('o'<<8)+'b') ){       /* CLOB */

  108509.       aff = SQLITE_AFF_TEXT;

  108510.     }else if( h==(('t'<<24)+('e'<<16)+('x'<<8)+'t') ){       /* TEXT */

  108511.       aff = SQLITE_AFF_TEXT;

  108512.     }else if( h==(('b'<<24)+('l'<<16)+('o'<<8)+'b')          /* BLOB */

  108513.         && (aff==SQLITE_AFF_NUMERIC || aff==SQLITE_AFF_REAL) ){

  108514.       aff = SQLITE_AFF_BLOB;

  108515.       if( zIn[0]=='(' ) zChar = zIn;

  108516. #ifndef SQLITE_OMIT_FLOATING_POINT

  108517.     }else if( h==(('r'<<24)+('e'<<16)+('a'<<8)+'l')          /* REAL */

  108518.         && aff==SQLITE_AFF_NUMERIC ){

  108519.       aff = SQLITE_AFF_REAL;

  108520.     }else if( h==(('f'<<24)+('l'<<16)+('o'<<8)+'a')          /* FLOA */

  108521.         && aff==SQLITE_AFF_NUMERIC ){

  108522.       aff = SQLITE_AFF_REAL;

  108523.     }else if( h==(('d'<<24)+('o'<<16)+('u'<<8)+'b')          /* DOUB */

  108524.         && aff==SQLITE_AFF_NUMERIC ){

  108525.       aff = SQLITE_AFF_REAL;

  108526. #endif

  108527.     }else if( (h&0x00FFFFFF)==(('i'<<16)+('n'<<8)+'t') ){    /* INT */

  108528.       aff = SQLITE_AFF_INTEGER;

  108529.       break;

  108530.     }

  108531.   }

  108532. 

  108533.   /* If pCol is not NULL, store an estimate of the field size.  The

  108534.   ** estimate is scaled so that the size of an integer is 1.  */

  108535.   if( pCol ){

  108536.     int v = 0;   /* default size is approx 4 bytes */

  108537.     if( aff<SQLITE_AFF_NUMERIC ){

  108538.       if( zChar ){

  108539.         while( zChar[0] ){

  108540.           if( sqlite3Isdigit(zChar[0]) ){

  108541.             /* BLOB(k), VARCHAR(k), CHAR(k) -> r=(k/4+1) */

  108542.             sqlite3GetInt32(zChar, &v);

  108543.             break;

  108544.           }

  108545.           zChar++;

  108546.         }

  108547.       }else{

  108548.         v = 16;   /* BLOB, TEXT, CLOB -> r=5  (approx 20 bytes)*/

  108549.       }

  108550.     }

  108551. #ifdef SQLITE_ENABLE_SORTER_REFERENCES

  108552.     if( v>=sqlite3GlobalConfig.szSorterRef ){

  108553.       pCol->colFlags |= COLFLAG_SORTERREF;

  108554.     }

  108555. #endif

  108556.     v = v/4 + 1;

  108557.     if( v>255 ) v = 255;

  108558.     pCol->szEst = v;

  108559.   }

  108560.   return aff;

  108561. }

  108562. 

  108563. /*

  108564. ** The expression is the default value for the most recently added column

  108565. ** of the table currently under construction.

  108566. **

  108567. ** Default value expressions must be constant.  Raise an exception if this

  108568. ** is not the case.

  108569. **

  108570. ** This routine is called by the parser while in the middle of

  108571. ** parsing a CREATE TABLE statement.

  108572. */

  108573. SQLITE_PRIVATE void sqlite3AddDefaultValue(

  108574.   Parse *pParse,           /* Parsing context */

  108575.   Expr *pExpr,             /* The parsed expression of the default value */

  108576.   const char *zStart,      /* Start of the default value text */

  108577.   const char *zEnd         /* First character past end of defaut value text */

  108578. ){

  108579.   Table *p;

  108580.   Column *pCol;

  108581.   sqlite3 *db = pParse->db;

  108582.   p = pParse->pNewTable;

  108583.   if( p!=0 ){

  108584.     pCol = &(p->aCol[p->nCol-1]);

  108585.     if( !sqlite3ExprIsConstantOrFunction(pExpr, db->init.busy) ){

  108586.       sqlite3ErrorMsg(pParse, "default value of column [%s] is not constant",

  108587.           pCol->zName);

  108588.     }else{

  108589.       /* A copy of pExpr is used instead of the original, as pExpr contains

  108590.       ** tokens that point to volatile memory.

  108591.       */

  108592.       Expr x;

  108593.       sqlite3ExprDelete(db, pCol->pDflt);

  108594.       memset(&x, 0, sizeof(x));

  108595.       x.op = TK_SPAN;

  108596.       x.u.zToken = sqlite3DbSpanDup(db, zStart, zEnd);

  108597.       x.pLeft = pExpr;

  108598.       x.flags = EP_Skip;

  108599.       pCol->pDflt = sqlite3ExprDup(db, &x, EXPRDUP_REDUCE);

  108600.       sqlite3DbFree(db, x.u.zToken);

  108601.     }

  108602.   }

  108603.   if( IN_RENAME_OBJECT ){

  108604.     sqlite3RenameExprUnmap(pParse, pExpr);

  108605.   }

  108606.   sqlite3ExprDelete(db, pExpr);

  108607. }

  108608. 

  108609. /*

  108610. ** Backwards Compatibility Hack:

  108611. ** 

  108612. ** Historical versions of SQLite accepted strings as column names in

  108613. ** indexes and PRIMARY KEY constraints and in UNIQUE constraints.  Example:

  108614. **

  108615. **     CREATE TABLE xyz(a,b,c,d,e,PRIMARY KEY('a'),UNIQUE('b','c' COLLATE trim)

  108616. **     CREATE INDEX abc ON xyz('c','d' DESC,'e' COLLATE nocase DESC);

  108617. **

  108618. ** This is goofy.  But to preserve backwards compatibility we continue to

  108619. ** accept it.  This routine does the necessary conversion.  It converts

  108620. ** the expression given in its argument from a TK_STRING into a TK_ID

  108621. ** if the expression is just a TK_STRING with an optional COLLATE clause.

  108622. ** If the expression is anything other than TK_STRING, the expression is

  108623. ** unchanged.

  108624. */

  108625. static void sqlite3StringToId(Expr *p){

  108626.   if( p->op==TK_STRING ){

  108627.     p->op = TK_ID;

  108628.   }else if( p->op==TK_COLLATE && p->pLeft->op==TK_STRING ){

  108629.     p->pLeft->op = TK_ID;

  108630.   }

  108631. }

  108632. 

  108633. /*

  108634. ** Designate the PRIMARY KEY for the table.  pList is a list of names 

  108635. ** of columns that form the primary key.  If pList is NULL, then the

  108636. ** most recently added column of the table is the primary key.

  108637. **

  108638. ** A table can have at most one primary key.  If the table already has

  108639. ** a primary key (and this is the second primary key) then create an

  108640. ** error.

  108641. **

  108642. ** If the PRIMARY KEY is on a single column whose datatype is INTEGER,

  108643. ** then we will try to use that column as the rowid.  Set the Table.iPKey

  108644. ** field of the table under construction to be the index of the

  108645. ** INTEGER PRIMARY KEY column.  Table.iPKey is set to -1 if there is

  108646. ** no INTEGER PRIMARY KEY.

  108647. **

  108648. ** If the key is not an INTEGER PRIMARY KEY, then create a unique

  108649. ** index for the key.  No index is created for INTEGER PRIMARY KEYs.

  108650. */

  108651. SQLITE_PRIVATE void sqlite3AddPrimaryKey(

  108652.   Parse *pParse,    /* Parsing context */

  108653.   ExprList *pList,  /* List of field names to be indexed */

  108654.   int onError,      /* What to do with a uniqueness conflict */

  108655.   int autoInc,      /* True if the AUTOINCREMENT keyword is present */

  108656.   int sortOrder     /* SQLITE_SO_ASC or SQLITE_SO_DESC */

  108657. ){

  108658.   Table *pTab = pParse->pNewTable;

  108659.   Column *pCol = 0;

  108660.   int iCol = -1, i;

  108661.   int nTerm;

  108662.   if( pTab==0 ) goto primary_key_exit;

  108663.   if( pTab->tabFlags & TF_HasPrimaryKey ){

  108664.     sqlite3ErrorMsg(pParse, 

  108665.       "table \"%s\" has more than one primary key", pTab->zName);

  108666.     goto primary_key_exit;

  108667.   }

  108668.   pTab->tabFlags |= TF_HasPrimaryKey;

  108669.   if( pList==0 ){

  108670.     iCol = pTab->nCol - 1;

  108671.     pCol = &pTab->aCol[iCol];

  108672.     pCol->colFlags |= COLFLAG_PRIMKEY;

  108673.     nTerm = 1;

  108674.   }else{

  108675.     nTerm = pList->nExpr;

  108676.     for(i=0; i<nTerm; i++){

  108677.       Expr *pCExpr = sqlite3ExprSkipCollate(pList->a[i].pExpr);

  108678.       assert( pCExpr!=0 );

  108679.       sqlite3StringToId(pCExpr);

  108680.       if( pCExpr->op==TK_ID ){

  108681.         const char *zCName = pCExpr->u.zToken;

  108682.         for(iCol=0; iCol<pTab->nCol; iCol++){

  108683.           if( sqlite3StrICmp(zCName, pTab->aCol[iCol].zName)==0 ){

  108684.             pCol = &pTab->aCol[iCol];

  108685.             pCol->colFlags |= COLFLAG_PRIMKEY;

  108686.             break;

  108687.           }

  108688.         }

  108689.       }

  108690.     }

  108691.   }

  108692.   if( nTerm==1

  108693.    && pCol

  108694.    && sqlite3StrICmp(sqlite3ColumnType(pCol,""), "INTEGER")==0

  108695.    && sortOrder!=SQLITE_SO_DESC

  108696.   ){

  108697.     if( IN_RENAME_OBJECT && pList ){

  108698.       Expr *pCExpr = sqlite3ExprSkipCollate(pList->a[0].pExpr);

  108699.       sqlite3RenameTokenRemap(pParse, &pTab->iPKey, pCExpr);

  108700.     }

  108701.     pTab->iPKey = iCol;

  108702.     pTab->keyConf = (u8)onError;

  108703.     assert( autoInc==0 || autoInc==1 );

  108704.     pTab->tabFlags |= autoInc*TF_Autoincrement;

  108705.     if( pList ) pParse->iPkSortOrder = pList->a[0].sortOrder;

  108706.   }else if( autoInc ){

  108707. #ifndef SQLITE_OMIT_AUTOINCREMENT

  108708.     sqlite3ErrorMsg(pParse, "AUTOINCREMENT is only allowed on an "

  108709.        "INTEGER PRIMARY KEY");

  108710. #endif

  108711.   }else{

  108712.     sqlite3CreateIndex(pParse, 0, 0, 0, pList, onError, 0,

  108713.                            0, sortOrder, 0, SQLITE_IDXTYPE_PRIMARYKEY);

  108714.     pList = 0;

  108715.   }

  108716. 

  108717. primary_key_exit:

  108718.   sqlite3ExprListDelete(pParse->db, pList);

  108719.   return;

  108720. }

  108721. 

  108722. /*

  108723. ** Add a new CHECK constraint to the table currently under construction.

  108724. */

  108725. SQLITE_PRIVATE void sqlite3AddCheckConstraint(

  108726.   Parse *pParse,    /* Parsing context */

  108727.   Expr *pCheckExpr  /* The check expression */

  108728. ){

  108729. #ifndef SQLITE_OMIT_CHECK

  108730.   Table *pTab = pParse->pNewTable;

  108731.   sqlite3 *db = pParse->db;

  108732.   if( pTab && !IN_DECLARE_VTAB

  108733.    && !sqlite3BtreeIsReadonly(db->aDb[db->init.iDb].pBt)

  108734.   ){

  108735.     pTab->pCheck = sqlite3ExprListAppend(pParse, pTab->pCheck, pCheckExpr);

  108736.     if( pParse->constraintName.n ){

  108737.       sqlite3ExprListSetName(pParse, pTab->pCheck, &pParse->constraintName, 1);

  108738.     }

  108739.   }else

  108740. #endif

  108741.   {

  108742.     sqlite3ExprDelete(pParse->db, pCheckExpr);

  108743.   }

  108744. }

  108745. 

  108746. /*

  108747. ** Set the collation function of the most recently parsed table column

  108748. ** to the CollSeq given.

  108749. */

  108750. SQLITE_PRIVATE void sqlite3AddCollateType(Parse *pParse, Token *pToken){

  108751.   Table *p;

  108752.   int i;

  108753.   char *zColl;              /* Dequoted name of collation sequence */

  108754.   sqlite3 *db;

  108755. 

  108756.   if( (p = pParse->pNewTable)==0 ) return;

  108757.   i = p->nCol-1;

  108758.   db = pParse->db;

  108759.   zColl = sqlite3NameFromToken(db, pToken);

  108760.   if( !zColl ) return;

  108761. 

  108762.   if( sqlite3LocateCollSeq(pParse, zColl) ){

  108763.     Index *pIdx;

  108764.     sqlite3DbFree(db, p->aCol[i].zColl);

  108765.     p->aCol[i].zColl = zColl;

  108766.   

  108767.     /* If the column is declared as "<name> PRIMARY KEY COLLATE <type>",

  108768.     ** then an index may have been created on this column before the

  108769.     ** collation type was added. Correct this if it is the case.

  108770.     */

  108771.     for(pIdx=p->pIndex; pIdx; pIdx=pIdx->pNext){

  108772.       assert( pIdx->nKeyCol==1 );

  108773.       if( pIdx->aiColumn[0]==i ){

  108774.         pIdx->azColl[0] = p->aCol[i].zColl;

  108775.       }

  108776.     }

  108777.   }else{

  108778.     sqlite3DbFree(db, zColl);

  108779.   }

  108780. }

  108781. 

  108782. /*

  108783. ** This function returns the collation sequence for database native text

  108784. ** encoding identified by the string zName, length nName.

  108785. **

  108786. ** If the requested collation sequence is not available, or not available

  108787. ** in the database native encoding, the collation factory is invoked to

  108788. ** request it. If the collation factory does not supply such a sequence,

  108789. ** and the sequence is available in another text encoding, then that is

  108790. ** returned instead.

  108791. **

  108792. ** If no versions of the requested collations sequence are available, or

  108793. ** another error occurs, NULL is returned and an error message written into

  108794. ** pParse.

  108795. **

  108796. ** This routine is a wrapper around sqlite3FindCollSeq().  This routine

  108797. ** invokes the collation factory if the named collation cannot be found

  108798. ** and generates an error message.

  108799. **

  108800. ** See also: sqlite3FindCollSeq(), sqlite3GetCollSeq()

  108801. */

  108802. SQLITE_PRIVATE CollSeq *sqlite3LocateCollSeq(Parse *pParse, const char *zName){

  108803.   sqlite3 *db = pParse->db;

  108804.   u8 enc = ENC(db);

  108805.   u8 initbusy = db->init.busy;

  108806.   CollSeq *pColl;

  108807. 

  108808.   pColl = sqlite3FindCollSeq(db, enc, zName, initbusy);

  108809.   if( !initbusy && (!pColl || !pColl->xCmp) ){

  108810.     pColl = sqlite3GetCollSeq(pParse, enc, pColl, zName);

  108811.   }

  108812. 

  108813.   return pColl;

  108814. }

  108815. 

  108816. 

  108817. /*

  108818. ** Generate code that will increment the schema cookie.

  108819. **

  108820. ** The schema cookie is used to determine when the schema for the

  108821. ** database changes.  After each schema change, the cookie value

  108822. ** changes.  When a process first reads the schema it records the

  108823. ** cookie.  Thereafter, whenever it goes to access the database,

  108824. ** it checks the cookie to make sure the schema has not changed

  108825. ** since it was last read.

  108826. **

  108827. ** This plan is not completely bullet-proof.  It is possible for

  108828. ** the schema to change multiple times and for the cookie to be

  108829. ** set back to prior value.  But schema changes are infrequent

  108830. ** and the probability of hitting the same cookie value is only

  108831. ** 1 chance in 2^32.  So we're safe enough.

  108832. **

  108833. ** IMPLEMENTATION-OF: R-34230-56049 SQLite automatically increments

  108834. ** the schema-version whenever the schema changes.

  108835. */

  108836. SQLITE_PRIVATE void sqlite3ChangeCookie(Parse *pParse, int iDb){

  108837.   sqlite3 *db = pParse->db;

  108838.   Vdbe *v = pParse->pVdbe;

  108839.   assert( sqlite3SchemaMutexHeld(db, iDb, 0) );

  108840.   sqlite3VdbeAddOp3(v, OP_SetCookie, iDb, BTREE_SCHEMA_VERSION, 

  108841.                    (int)(1+(unsigned)db->aDb[iDb].pSchema->schema_cookie));

  108842. }

  108843. 

  108844. /*

  108845. ** Measure the number of characters needed to output the given

  108846. ** identifier.  The number returned includes any quotes used

  108847. ** but does not include the null terminator.

  108848. **

  108849. ** The estimate is conservative.  It might be larger that what is

  108850. ** really needed.

  108851. */

  108852. static int identLength(const char *z){

  108853.   int n;

  108854.   for(n=0; *z; n++, z++){

  108855.     if( *z=='"' ){ n++; }

  108856.   }

  108857.   return n + 2;

  108858. }

  108859. 

  108860. /*

  108861. ** The first parameter is a pointer to an output buffer. The second 

  108862. ** parameter is a pointer to an integer that contains the offset at

  108863. ** which to write into the output buffer. This function copies the

  108864. ** nul-terminated string pointed to by the third parameter, zSignedIdent,

  108865. ** to the specified offset in the buffer and updates *pIdx to refer

  108866. ** to the first byte after the last byte written before returning.

  108867. ** 

  108868. ** If the string zSignedIdent consists entirely of alpha-numeric

  108869. ** characters, does not begin with a digit and is not an SQL keyword,

  108870. ** then it is copied to the output buffer exactly as it is. Otherwise,

  108871. ** it is quoted using double-quotes.

  108872. */

  108873. static void identPut(char *z, int *pIdx, char *zSignedIdent){

  108874.   unsigned char *zIdent = (unsigned char*)zSignedIdent;

  108875.   int i, j, needQuote;

  108876.   i = *pIdx;

  108877. 

  108878.   for(j=0; zIdent[j]; j++){

  108879.     if( !sqlite3Isalnum(zIdent[j]) && zIdent[j]!='_' ) break;

  108880.   }

  108881.   needQuote = sqlite3Isdigit(zIdent[0])

  108882.             || sqlite3KeywordCode(zIdent, j)!=TK_ID

  108883.             || zIdent[j]!=0

  108884.             || j==0;

  108885. 

  108886.   if( needQuote ) z[i++] = '"';

  108887.   for(j=0; zIdent[j]; j++){

  108888.     z[i++] = zIdent[j];

  108889.     if( zIdent[j]=='"' ) z[i++] = '"';

  108890.   }

  108891.   if( needQuote ) z[i++] = '"';

  108892.   z[i] = 0;

  108893.   *pIdx = i;

  108894. }

  108895. 

  108896. /*

  108897. ** Generate a CREATE TABLE statement appropriate for the given

  108898. ** table.  Memory to hold the text of the statement is obtained

  108899. ** from sqliteMalloc() and must be freed by the calling function.

  108900. */

  108901. static char *createTableStmt(sqlite3 *db, Table *p){

  108902.   int i, k, n;

  108903.   char *zStmt;

  108904.   char *zSep, *zSep2, *zEnd;

  108905.   Column *pCol;

  108906.   n = 0;

  108907.   for(pCol = p->aCol, i=0; i<p->nCol; i++, pCol++){

  108908.     n += identLength(pCol->zName) + 5;

  108909.   }

  108910.   n += identLength(p->zName);

  108911.   if( n<50 ){ 

  108912.     zSep = "";

  108913.     zSep2 = ",";

  108914.     zEnd = ")";

  108915.   }else{

  108916.     zSep = "\n  ";

  108917.     zSep2 = ",\n  ";

  108918.     zEnd = "\n)";

  108919.   }

  108920.   n += 35 + 6*p->nCol;

  108921.   zStmt = sqlite3DbMallocRaw(0, n);

  108922.   if( zStmt==0 ){

  108923.     sqlite3OomFault(db);

  108924.     return 0;

  108925.   }

  108926.   sqlite3_snprintf(n, zStmt, "CREATE TABLE ");

  108927.   k = sqlite3Strlen30(zStmt);

  108928.   identPut(zStmt, &k, p->zName);

  108929.   zStmt[k++] = '(';

  108930.   for(pCol=p->aCol, i=0; i<p->nCol; i++, pCol++){

  108931.     static const char * const azType[] = {

  108932.         /* SQLITE_AFF_BLOB    */ "",

  108933.         /* SQLITE_AFF_TEXT    */ " TEXT",

  108934.         /* SQLITE_AFF_NUMERIC */ " NUM",

  108935.         /* SQLITE_AFF_INTEGER */ " INT",

  108936.         /* SQLITE_AFF_REAL    */ " REAL"

  108937.     };

  108938.     int len;

  108939.     const char *zType;

  108940. 

  108941.     sqlite3_snprintf(n-k, &zStmt[k], zSep);

  108942.     k += sqlite3Strlen30(&zStmt[k]);

  108943.     zSep = zSep2;

  108944.     identPut(zStmt, &k, pCol->zName);

  108945.     assert( pCol->affinity-SQLITE_AFF_BLOB >= 0 );

  108946.     assert( pCol->affinity-SQLITE_AFF_BLOB < ArraySize(azType) );

  108947.     testcase( pCol->affinity==SQLITE_AFF_BLOB );

  108948.     testcase( pCol->affinity==SQLITE_AFF_TEXT );

  108949.     testcase( pCol->affinity==SQLITE_AFF_NUMERIC );

  108950.     testcase( pCol->affinity==SQLITE_AFF_INTEGER );

  108951.     testcase( pCol->affinity==SQLITE_AFF_REAL );

  108952.     

  108953.     zType = azType[pCol->affinity - SQLITE_AFF_BLOB];

  108954.     len = sqlite3Strlen30(zType);

  108955.     assert( pCol->affinity==SQLITE_AFF_BLOB 

  108956.             || pCol->affinity==sqlite3AffinityType(zType, 0) );

  108957.     memcpy(&zStmt[k], zType, len);

  108958.     k += len;

  108959.     assert( k<=n );

  108960.   }

  108961.   sqlite3_snprintf(n-k, &zStmt[k], "%s", zEnd);

  108962.   return zStmt;

  108963. }

  108964. 

  108965. /*

  108966. ** Resize an Index object to hold N columns total.  Return SQLITE_OK

  108967. ** on success and SQLITE_NOMEM on an OOM error.

  108968. */

  108969. static int resizeIndexObject(sqlite3 *db, Index *pIdx, int N){

  108970.   char *zExtra;

  108971.   int nByte;

  108972.   if( pIdx->nColumn>=N ) return SQLITE_OK;

  108973.   assert( pIdx->isResized==0 );

  108974.   nByte = (sizeof(char*) + sizeof(i16) + 1)*N;

  108975.   zExtra = sqlite3DbMallocZero(db, nByte);

  108976.   if( zExtra==0 ) return SQLITE_NOMEM_BKPT;

  108977.   memcpy(zExtra, pIdx->azColl, sizeof(char*)*pIdx->nColumn);

  108978.   pIdx->azColl = (const char**)zExtra;

  108979.   zExtra += sizeof(char*)*N;

  108980.   memcpy(zExtra, pIdx->aiColumn, sizeof(i16)*pIdx->nColumn);

  108981.   pIdx->aiColumn = (i16*)zExtra;

  108982.   zExtra += sizeof(i16)*N;

  108983.   memcpy(zExtra, pIdx->aSortOrder, pIdx->nColumn);

  108984.   pIdx->aSortOrder = (u8*)zExtra;

  108985.   pIdx->nColumn = N;

  108986.   pIdx->isResized = 1;

  108987.   return SQLITE_OK;

  108988. }

  108989. 

  108990. /*

  108991. ** Estimate the total row width for a table.

  108992. */

  108993. static void estimateTableWidth(Table *pTab){

  108994.   unsigned wTable = 0;

  108995.   const Column *pTabCol;

  108996.   int i;

  108997.   for(i=pTab->nCol, pTabCol=pTab->aCol; i>0; i--, pTabCol++){

  108998.     wTable += pTabCol->szEst;

  108999.   }

  109000.   if( pTab->iPKey<0 ) wTable++;

  109001.   pTab->szTabRow = sqlite3LogEst(wTable*4);

  109002. }

  109003. 

  109004. /*

  109005. ** Estimate the average size of a row for an index.

  109006. */

  109007. static void estimateIndexWidth(Index *pIdx){

  109008.   unsigned wIndex = 0;

  109009.   int i;

  109010.   const Column *aCol = pIdx->pTable->aCol;

  109011.   for(i=0; i<pIdx->nColumn; i++){

  109012.     i16 x = pIdx->aiColumn[i];

  109013.     assert( x<pIdx->pTable->nCol );

  109014.     wIndex += x<0 ? 1 : aCol[pIdx->aiColumn[i]].szEst;

  109015.   }

  109016.   pIdx->szIdxRow = sqlite3LogEst(wIndex*4);

  109017. }

  109018. 

  109019. /* Return true if column number x is any of the first nCol entries of aiCol[].

  109020. ** This is used to determine if the column number x appears in any of the

  109021. ** first nCol entries of an index.

  109022. */

  109023. static int hasColumn(const i16 *aiCol, int nCol, int x){

  109024.   while( nCol-- > 0 ){

  109025.     assert( aiCol[0]>=0 );

  109026.     if( x==*(aiCol++) ){

  109027.       return 1;

  109028.     }

  109029.   }

  109030.   return 0;

  109031. }

  109032. 

  109033. /*

  109034. ** Return true if any of the first nKey entries of index pIdx exactly

  109035. ** match the iCol-th entry of pPk.  pPk is always a WITHOUT ROWID

  109036. ** PRIMARY KEY index.  pIdx is an index on the same table.  pIdx may

  109037. ** or may not be the same index as pPk.

  109038. **

  109039. ** The first nKey entries of pIdx are guaranteed to be ordinary columns,

  109040. ** not a rowid or expression.

  109041. **

  109042. ** This routine differs from hasColumn() in that both the column and the

  109043. ** collating sequence must match for this routine, but for hasColumn() only

  109044. ** the column name must match.

  109045. */

  109046. static int isDupColumn(Index *pIdx, int nKey, Index *pPk, int iCol){

  109047.   int i, j;

  109048.   assert( nKey<=pIdx->nColumn );

  109049.   assert( iCol<MAX(pPk->nColumn,pPk->nKeyCol) );

  109050.   assert( pPk->idxType==SQLITE_IDXTYPE_PRIMARYKEY );

  109051.   assert( pPk->pTable->tabFlags & TF_WithoutRowid );

  109052.   assert( pPk->pTable==pIdx->pTable );

  109053.   testcase( pPk==pIdx );

  109054.   j = pPk->aiColumn[iCol];

  109055.   assert( j!=XN_ROWID && j!=XN_EXPR );

  109056.   for(i=0; i<nKey; i++){

  109057.     assert( pIdx->aiColumn[i]>=0 || j>=0 );

  109058.     if( pIdx->aiColumn[i]==j 

  109059.      && sqlite3StrICmp(pIdx->azColl[i], pPk->azColl[iCol])==0

  109060.     ){

  109061.       return 1;

  109062.     }

  109063.   }

  109064.   return 0;

  109065. }

  109066. 

  109067. /* Recompute the colNotIdxed field of the Index.

  109068. **

  109069. ** colNotIdxed is a bitmask that has a 0 bit representing each indexed

  109070. ** columns that are within the first 63 columns of the table.  The

  109071. ** high-order bit of colNotIdxed is always 1.  All unindexed columns

  109072. ** of the table have a 1.

  109073. **

  109074. ** The colNotIdxed mask is AND-ed with the SrcList.a[].colUsed mask

  109075. ** to determine if the index is covering index.

  109076. */

  109077. static void recomputeColumnsNotIndexed(Index *pIdx){

  109078.   Bitmask m = 0;

  109079.   int j;

  109080.   for(j=pIdx->nColumn-1; j>=0; j--){

  109081.     int x = pIdx->aiColumn[j];

  109082.     if( x>=0 ){

  109083.       testcase( x==BMS-1 );

  109084.       testcase( x==BMS-2 );

  109085.       if( x<BMS-1 ) m |= MASKBIT(x);

  109086.     }

  109087.   }

  109088.   pIdx->colNotIdxed = ~m;

  109089.   assert( (pIdx->colNotIdxed>>63)==1 );

  109090. }

  109091. 

  109092. /*

  109093. ** This routine runs at the end of parsing a CREATE TABLE statement that

  109094. ** has a WITHOUT ROWID clause.  The job of this routine is to convert both

  109095. ** internal schema data structures and the generated VDBE code so that they

  109096. ** are appropriate for a WITHOUT ROWID table instead of a rowid table.

  109097. ** Changes include:

  109098. **

  109099. **     (1)  Set all columns of the PRIMARY KEY schema object to be NOT NULL.

  109100. **     (2)  Convert P3 parameter of the OP_CreateBtree from BTREE_INTKEY 

  109101. **          into BTREE_BLOBKEY.

  109102. **     (3)  Bypass the creation of the sqlite_master table entry

  109103. **          for the PRIMARY KEY as the primary key index is now

  109104. **          identified by the sqlite_master table entry of the table itself.

  109105. **     (4)  Set the Index.tnum of the PRIMARY KEY Index object in the

  109106. **          schema to the rootpage from the main table.

  109107. **     (5)  Add all table columns to the PRIMARY KEY Index object

  109108. **          so that the PRIMARY KEY is a covering index.  The surplus

  109109. **          columns are part of KeyInfo.nAllField and are not used for

  109110. **          sorting or lookup or uniqueness checks.

  109111. **     (6)  Replace the rowid tail on all automatically generated UNIQUE

  109112. **          indices with the PRIMARY KEY columns.

  109113. **

  109114. ** For virtual tables, only (1) is performed.

  109115. */

  109116. static void convertToWithoutRowidTable(Parse *pParse, Table *pTab){

  109117.   Index *pIdx;

  109118.   Index *pPk;

  109119.   int nPk;

  109120.   int i, j;

  109121.   sqlite3 *db = pParse->db;

  109122.   Vdbe *v = pParse->pVdbe;

  109123. 

  109124.   /* Mark every PRIMARY KEY column as NOT NULL (except for imposter tables)

  109125.   */

  109126.   if( !db->init.imposterTable ){

  109127.     for(i=0; i<pTab->nCol; i++){

  109128.       if( (pTab->aCol[i].colFlags & COLFLAG_PRIMKEY)!=0 ){

  109129.         pTab->aCol[i].notNull = OE_Abort;

  109130.       }

  109131.     }

  109132.   }

  109133. 

  109134.   /* Convert the P3 operand of the OP_CreateBtree opcode from BTREE_INTKEY

  109135.   ** into BTREE_BLOBKEY.

  109136.   */

  109137.   if( pParse->addrCrTab ){

  109138.     assert( v );

  109139.     sqlite3VdbeChangeP3(v, pParse->addrCrTab, BTREE_BLOBKEY);

  109140.   }

  109141. 

  109142.   /* Locate the PRIMARY KEY index.  Or, if this table was originally

  109143.   ** an INTEGER PRIMARY KEY table, create a new PRIMARY KEY index. 

  109144.   */

  109145.   if( pTab->iPKey>=0 ){

  109146.     ExprList *pList;

  109147.     Token ipkToken;

  109148.     sqlite3TokenInit(&ipkToken, pTab->aCol[pTab->iPKey].zName);

  109149.     pList = sqlite3ExprListAppend(pParse, 0, 

  109150.                   sqlite3ExprAlloc(db, TK_ID, &ipkToken, 0));

  109151.     if( pList==0 ) return;

  109152.     if( IN_RENAME_OBJECT ){

  109153.       sqlite3RenameTokenRemap(pParse, pList->a[0].pExpr, &pTab->iPKey);

  109154.     }

  109155.     pList->a[0].sortOrder = pParse->iPkSortOrder;

  109156.     assert( pParse->pNewTable==pTab );

  109157.     pTab->iPKey = -1;

  109158.     sqlite3CreateIndex(pParse, 0, 0, 0, pList, pTab->keyConf, 0, 0, 0, 0,

  109159.                        SQLITE_IDXTYPE_PRIMARYKEY);

  109160.     if( db->mallocFailed || pParse->nErr ) return;

  109161.     pPk = sqlite3PrimaryKeyIndex(pTab);

  109162.   }else{

  109163.     pPk = sqlite3PrimaryKeyIndex(pTab);

  109164.     assert( pPk!=0 );

  109165. 

  109166.     /*

  109167.     ** Remove all redundant columns from the PRIMARY KEY.  For example, change

  109168.     ** "PRIMARY KEY(a,b,a,b,c,b,c,d)" into just "PRIMARY KEY(a,b,c,d)".  Later

  109169.     ** code assumes the PRIMARY KEY contains no repeated columns.

  109170.     */

  109171.     for(i=j=1; i<pPk->nKeyCol; i++){

  109172.       if( isDupColumn(pPk, j, pPk, i) ){

  109173.         pPk->nColumn--;

  109174.       }else{

  109175.         testcase( hasColumn(pPk->aiColumn, j, pPk->aiColumn[i]) );

  109176.         pPk->aiColumn[j++] = pPk->aiColumn[i];

  109177.       }

  109178.     }

  109179.     pPk->nKeyCol = j;

  109180.   }

  109181.   assert( pPk!=0 );

  109182.   pPk->isCovering = 1;

  109183.   if( !db->init.imposterTable ) pPk->uniqNotNull = 1;

  109184.   nPk = pPk->nKeyCol;

  109185. 

  109186.   /* Bypass the creation of the PRIMARY KEY btree and the sqlite_master

  109187.   ** table entry. This is only required if currently generating VDBE

  109188.   ** code for a CREATE TABLE (not when parsing one as part of reading

  109189.   ** a database schema).  */

  109190.   if( v && pPk->tnum>0 ){

  109191.     assert( db->init.busy==0 );

  109192.     sqlite3VdbeChangeOpcode(v, pPk->tnum, OP_Goto);

  109193.   }

  109194. 

  109195.   /* The root page of the PRIMARY KEY is the table root page */

  109196.   pPk->tnum = pTab->tnum;

  109197. 

  109198.   /* Update the in-memory representation of all UNIQUE indices by converting

  109199.   ** the final rowid column into one or more columns of the PRIMARY KEY.

  109200.   */

  109201.   for(pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext){

  109202.     int n;

  109203.     if( IsPrimaryKeyIndex(pIdx) ) continue;

  109204.     for(i=n=0; i<nPk; i++){

  109205.       if( !isDupColumn(pIdx, pIdx->nKeyCol, pPk, i) ){

  109206.         testcase( hasColumn(pIdx->aiColumn, pIdx->nKeyCol, pPk->aiColumn[i]) );

  109207.         n++;

  109208.       }

  109209.     }

  109210.     if( n==0 ){

  109211.       /* This index is a superset of the primary key */

  109212.       pIdx->nColumn = pIdx->nKeyCol;

  109213.       continue;

  109214.     }

  109215.     if( resizeIndexObject(db, pIdx, pIdx->nKeyCol+n) ) return;

  109216.     for(i=0, j=pIdx->nKeyCol; i<nPk; i++){

  109217.       if( !isDupColumn(pIdx, pIdx->nKeyCol, pPk, i) ){

  109218.         testcase( hasColumn(pIdx->aiColumn, pIdx->nKeyCol, pPk->aiColumn[i]) );

  109219.         pIdx->aiColumn[j] = pPk->aiColumn[i];

  109220.         pIdx->azColl[j] = pPk->azColl[i];

  109221.         if( pPk->aSortOrder[i] ){

  109222.           /* See ticket https://www.sqlite.org/src/info/bba7b69f9849b5bf */

  109223.           pIdx->bAscKeyBug = 1;

  109224.         }

  109225.         j++;

  109226.       }

  109227.     }

  109228.     assert( pIdx->nColumn>=pIdx->nKeyCol+n );

  109229.     assert( pIdx->nColumn>=j );

  109230.   }

  109231. 

  109232.   /* Add all table columns to the PRIMARY KEY index

  109233.   */

  109234.   if( nPk<pTab->nCol ){

  109235.     if( resizeIndexObject(db, pPk, pTab->nCol) ) return;

  109236.     for(i=0, j=nPk; i<pTab->nCol; i++){

  109237.       if( !hasColumn(pPk->aiColumn, j, i) ){

  109238.         assert( j<pPk->nColumn );

  109239.         pPk->aiColumn[j] = i;

  109240.         pPk->azColl[j] = sqlite3StrBINARY;

  109241.         j++;

  109242.       }

  109243.     }

  109244.     assert( pPk->nColumn==j );

  109245.     assert( pTab->nCol==j );

  109246.   }else{

  109247.     pPk->nColumn = pTab->nCol;

  109248.   }

  109249.   recomputeColumnsNotIndexed(pPk);

  109250. }

  109251. 

  109252. #ifndef SQLITE_OMIT_VIRTUALTABLE

  109253. /*

  109254. ** Return true if zName is a shadow table name in the current database

  109255. ** connection.

  109256. **

  109257. ** zName is temporarily modified while this routine is running, but is

  109258. ** restored to its original value prior to this routine returning.

  109259. */

  109260. static int isShadowTableName(sqlite3 *db, char *zName){

  109261.   char *zTail;                  /* Pointer to the last "_" in zName */

  109262.   Table *pTab;                  /* Table that zName is a shadow of */

  109263.   Module *pMod;                 /* Module for the virtual table */

  109264. 

  109265.   zTail = strrchr(zName, '_');

  109266.   if( zTail==0 ) return 0;

  109267.   *zTail = 0;

  109268.   pTab = sqlite3FindTable(db, zName, 0);

  109269.   *zTail = '_';

  109270.   if( pTab==0 ) return 0;

  109271.   if( !IsVirtual(pTab) ) return 0;

  109272.   pMod = (Module*)sqlite3HashFind(&db->aModule, pTab->azModuleArg[0]);

  109273.   if( pMod==0 ) return 0;

  109274.   if( pMod->pModule->iVersion<3 ) return 0;

  109275.   if( pMod->pModule->xShadowName==0 ) return 0;

  109276.   return pMod->pModule->xShadowName(zTail+1);

  109277. }

  109278. #else

  109279. # define isShadowTableName(x,y) 0

  109280. #endif /* ifndef SQLITE_OMIT_VIRTUALTABLE */

  109281. 

  109282. /*

  109283. ** This routine is called to report the final ")" that terminates

  109284. ** a CREATE TABLE statement.

  109285. **

  109286. ** The table structure that other action routines have been building

  109287. ** is added to the internal hash tables, assuming no errors have

  109288. ** occurred.

  109289. **

  109290. ** An entry for the table is made in the master table on disk, unless

  109291. ** this is a temporary table or db->init.busy==1.  When db->init.busy==1

  109292. ** it means we are reading the sqlite_master table because we just

  109293. ** connected to the database or because the sqlite_master table has

  109294. ** recently changed, so the entry for this table already exists in

  109295. ** the sqlite_master table.  We do not want to create it again.

  109296. **

  109297. ** If the pSelect argument is not NULL, it means that this routine

  109298. ** was called to create a table generated from a 

  109299. ** "CREATE TABLE ... AS SELECT ..." statement.  The column names of

  109300. ** the new table will match the result set of the SELECT.

  109301. */

  109302. SQLITE_PRIVATE void sqlite3EndTable(

  109303.   Parse *pParse,          /* Parse context */

  109304.   Token *pCons,           /* The ',' token after the last column defn. */

  109305.   Token *pEnd,            /* The ')' before options in the CREATE TABLE */

  109306.   u8 tabOpts,             /* Extra table options. Usually 0. */

  109307.   Select *pSelect         /* Select from a "CREATE ... AS SELECT" */

  109308. ){

  109309.   Table *p;                 /* The new table */

  109310.   sqlite3 *db = pParse->db; /* The database connection */

  109311.   int iDb;                  /* Database in which the table lives */

  109312.   Index *pIdx;              /* An implied index of the table */

  109313. 

  109314.   if( pEnd==0 && pSelect==0 ){

  109315.     return;

  109316.   }

  109317.   assert( !db->mallocFailed );

  109318.   p = pParse->pNewTable;

  109319.   if( p==0 ) return;

  109320. 

  109321.   if( pSelect==0 && isShadowTableName(db, p->zName) ){

  109322.     p->tabFlags |= TF_Shadow;

  109323.   }

  109324. 

  109325.   /* If the db->init.busy is 1 it means we are reading the SQL off the

  109326.   ** "sqlite_master" or "sqlite_temp_master" table on the disk.

  109327.   ** So do not write to the disk again.  Extract the root page number

  109328.   ** for the table from the db->init.newTnum field.  (The page number

  109329.   ** should have been put there by the sqliteOpenCb routine.)

  109330.   **

  109331.   ** If the root page number is 1, that means this is the sqlite_master

  109332.   ** table itself.  So mark it read-only.

  109333.   */

  109334.   if( db->init.busy ){

  109335.     if( pSelect ){

  109336.       sqlite3ErrorMsg(pParse, "");

  109337.       return;

  109338.     }

  109339.     p->tnum = db->init.newTnum;

  109340.     if( p->tnum==1 ) p->tabFlags |= TF_Readonly;

  109341.   }

  109342. 

  109343.   assert( (p->tabFlags & TF_HasPrimaryKey)==0

  109344.        || p->iPKey>=0 || sqlite3PrimaryKeyIndex(p)!=0 );

  109345.   assert( (p->tabFlags & TF_HasPrimaryKey)!=0

  109346.        || (p->iPKey<0 && sqlite3PrimaryKeyIndex(p)==0) );

  109347. 

  109348.   /* Special processing for WITHOUT ROWID Tables */

  109349.   if( tabOpts & TF_WithoutRowid ){

  109350.     if( (p->tabFlags & TF_Autoincrement) ){

  109351.       sqlite3ErrorMsg(pParse,

  109352.           "AUTOINCREMENT not allowed on WITHOUT ROWID tables");

  109353.       return;

  109354.     }

  109355.     if( (p->tabFlags & TF_HasPrimaryKey)==0 ){

  109356.       sqlite3ErrorMsg(pParse, "PRIMARY KEY missing on table %s", p->zName);

  109357.     }else{

  109358.       p->tabFlags |= TF_WithoutRowid | TF_NoVisibleRowid;

  109359.       convertToWithoutRowidTable(pParse, p);

  109360.     }

  109361.   }

  109362. 

  109363.   iDb = sqlite3SchemaToIndex(db, p->pSchema);

  109364. 

  109365. #ifndef SQLITE_OMIT_CHECK

  109366.   /* Resolve names in all CHECK constraint expressions.

  109367.   */

  109368.   if( p->pCheck ){

  109369.     sqlite3ResolveSelfReference(pParse, p, NC_IsCheck, 0, p->pCheck);

  109370.   }

  109371. #endif /* !defined(SQLITE_OMIT_CHECK) */

  109372. 

  109373.   /* Estimate the average row size for the table and for all implied indices */

  109374.   estimateTableWidth(p);

  109375.   for(pIdx=p->pIndex; pIdx; pIdx=pIdx->pNext){

  109376.     estimateIndexWidth(pIdx);

  109377.   }

  109378. 

  109379.   /* If not initializing, then create a record for the new table

  109380.   ** in the SQLITE_MASTER table of the database.

  109381.   **

  109382.   ** If this is a TEMPORARY table, write the entry into the auxiliary

  109383.   ** file instead of into the main database file.

  109384.   */

  109385.   if( !db->init.busy ){

  109386.     int n;

  109387.     Vdbe *v;

  109388.     char *zType;    /* "view" or "table" */

  109389.     char *zType2;   /* "VIEW" or "TABLE" */

  109390.     char *zStmt;    /* Text of the CREATE TABLE or CREATE VIEW statement */

  109391. 

  109392.     v = sqlite3GetVdbe(pParse);

  109393.     if( NEVER(v==0) ) return;

  109394. 

  109395.     sqlite3VdbeAddOp1(v, OP_Close, 0);

  109396. 

  109397.     /* 

  109398.     ** Initialize zType for the new view or table.

  109399.     */

  109400.     if( p->pSelect==0 ){

  109401.       /* A regular table */

  109402.       zType = "table";

  109403.       zType2 = "TABLE";

  109404. #ifndef SQLITE_OMIT_VIEW

  109405.     }else{

  109406.       /* A view */

  109407.       zType = "view";

  109408.       zType2 = "VIEW";

  109409. #endif

  109410.     }

  109411. 

  109412.     /* If this is a CREATE TABLE xx AS SELECT ..., execute the SELECT

  109413.     ** statement to populate the new table. The root-page number for the

  109414.     ** new table is in register pParse->regRoot.

  109415.     **

  109416.     ** Once the SELECT has been coded by sqlite3Select(), it is in a

  109417.     ** suitable state to query for the column names and types to be used

  109418.     ** by the new table.

  109419.     **

  109420.     ** A shared-cache write-lock is not required to write to the new table,

  109421.     ** as a schema-lock must have already been obtained to create it. Since

  109422.     ** a schema-lock excludes all other database users, the write-lock would

  109423.     ** be redundant.

  109424.     */

  109425.     if( pSelect ){

  109426.       SelectDest dest;    /* Where the SELECT should store results */

  109427.       int regYield;       /* Register holding co-routine entry-point */

  109428.       int addrTop;        /* Top of the co-routine */

  109429.       int regRec;         /* A record to be insert into the new table */

  109430.       int regRowid;       /* Rowid of the next row to insert */

  109431.       int addrInsLoop;    /* Top of the loop for inserting rows */

  109432.       Table *pSelTab;     /* A table that describes the SELECT results */

  109433. 

  109434.       regYield = ++pParse->nMem;

  109435.       regRec = ++pParse->nMem;

  109436.       regRowid = ++pParse->nMem;

  109437.       assert(pParse->nTab==1);

  109438.       sqlite3MayAbort(pParse);

  109439.       sqlite3VdbeAddOp3(v, OP_OpenWrite, 1, pParse->regRoot, iDb);

  109440.       sqlite3VdbeChangeP5(v, OPFLAG_P2ISREG);

  109441.       pParse->nTab = 2;

  109442.       addrTop = sqlite3VdbeCurrentAddr(v) + 1;

  109443.       sqlite3VdbeAddOp3(v, OP_InitCoroutine, regYield, 0, addrTop);

  109444.       if( pParse->nErr ) return;

  109445.       pSelTab = sqlite3ResultSetOfSelect(pParse, pSelect);

  109446.       if( pSelTab==0 ) return;

  109447.       assert( p->aCol==0 );

  109448.       p->nCol = pSelTab->nCol;

  109449.       p->aCol = pSelTab->aCol;

  109450.       pSelTab->nCol = 0;

  109451.       pSelTab->aCol = 0;

  109452.       sqlite3DeleteTable(db, pSelTab);

  109453.       sqlite3SelectDestInit(&dest, SRT_Coroutine, regYield);

  109454.       sqlite3Select(pParse, pSelect, &dest);

  109455.       if( pParse->nErr ) return;

  109456.       sqlite3VdbeEndCoroutine(v, regYield);

  109457.       sqlite3VdbeJumpHere(v, addrTop - 1);

  109458.       addrInsLoop = sqlite3VdbeAddOp1(v, OP_Yield, dest.iSDParm);

  109459.       VdbeCoverage(v);

  109460.       sqlite3VdbeAddOp3(v, OP_MakeRecord, dest.iSdst, dest.nSdst, regRec);

  109461.       sqlite3TableAffinity(v, p, 0);

  109462.       sqlite3VdbeAddOp2(v, OP_NewRowid, 1, regRowid);

  109463.       sqlite3VdbeAddOp3(v, OP_Insert, 1, regRec, regRowid);

  109464.       sqlite3VdbeGoto(v, addrInsLoop);

  109465.       sqlite3VdbeJumpHere(v, addrInsLoop);

  109466.       sqlite3VdbeAddOp1(v, OP_Close, 1);

  109467.     }

  109468. 

  109469.     /* Compute the complete text of the CREATE statement */

  109470.     if( pSelect ){

  109471.       zStmt = createTableStmt(db, p);

  109472.     }else{

  109473.       Token *pEnd2 = tabOpts ? &pParse->sLastToken : pEnd;

  109474.       n = (int)(pEnd2->z - pParse->sNameToken.z);

  109475.       if( pEnd2->z[0]!=';' ) n += pEnd2->n;

  109476.       zStmt = sqlite3MPrintf(db, 

  109477.           "CREATE %s %.*s", zType2, n, pParse->sNameToken.z

  109478.       );

  109479.     }

  109480. 

  109481.     /* A slot for the record has already been allocated in the 

  109482.     ** SQLITE_MASTER table.  We just need to update that slot with all

  109483.     ** the information we've collected.

  109484.     */

  109485.     sqlite3NestedParse(pParse,

  109486.       "UPDATE %Q.%s "

  109487.          "SET type='%s', name=%Q, tbl_name=%Q, rootpage=#%d, sql=%Q "

  109488.        "WHERE rowid=#%d",

  109489.       db->aDb[iDb].zDbSName, MASTER_NAME,

  109490.       zType,

  109491.       p->zName,

  109492.       p->zName,

  109493.       pParse->regRoot,

  109494.       zStmt,

  109495.       pParse->regRowid

  109496.     );

  109497.     sqlite3DbFree(db, zStmt);

  109498.     sqlite3ChangeCookie(pParse, iDb);

  109499. 

  109500. #ifndef SQLITE_OMIT_AUTOINCREMENT

  109501.     /* Check to see if we need to create an sqlite_sequence table for

  109502.     ** keeping track of autoincrement keys.

  109503.     */

  109504.     if( (p->tabFlags & TF_Autoincrement)!=0 ){

  109505.       Db *pDb = &db->aDb[iDb];

  109506.       assert( sqlite3SchemaMutexHeld(db, iDb, 0) );

  109507.       if( pDb->pSchema->pSeqTab==0 ){

  109508.         sqlite3NestedParse(pParse,

  109509.           "CREATE TABLE %Q.sqlite_sequence(name,seq)",

  109510.           pDb->zDbSName

  109511.         );

  109512.       }

  109513.     }

  109514. #endif

  109515. 

  109516.     /* Reparse everything to update our internal data structures */

  109517.     sqlite3VdbeAddParseSchemaOp(v, iDb,

  109518.            sqlite3MPrintf(db, "tbl_name='%q' AND type!='trigger'", p->zName));

  109519.   }

  109520. 

  109521. 

  109522.   /* Add the table to the in-memory representation of the database.

  109523.   */

  109524.   if( db->init.busy ){

  109525.     Table *pOld;

  109526.     Schema *pSchema = p->pSchema;

  109527.     assert( sqlite3SchemaMutexHeld(db, iDb, 0) );

  109528.     pOld = sqlite3HashInsert(&pSchema->tblHash, p->zName, p);

  109529.     if( pOld ){

  109530.       assert( p==pOld );  /* Malloc must have failed inside HashInsert() */

  109531.       sqlite3OomFault(db);

  109532.       return;

  109533.     }

  109534.     pParse->pNewTable = 0;

  109535.     db->mDbFlags |= DBFLAG_SchemaChange;

  109536. 

  109537. #ifndef SQLITE_OMIT_ALTERTABLE

  109538.     if( !p->pSelect ){

  109539.       const char *zName = (const char *)pParse->sNameToken.z;

  109540.       int nName;

  109541.       assert( !pSelect && pCons && pEnd );

  109542.       if( pCons->z==0 ){

  109543.         pCons = pEnd;

  109544.       }

  109545.       nName = (int)((const char *)pCons->z - zName);

  109546.       p->addColOffset = 13 + sqlite3Utf8CharLen(zName, nName);

  109547.     }

  109548. #endif

  109549.   }

  109550. }

  109551. 

  109552. #ifndef SQLITE_OMIT_VIEW

  109553. /*

  109554. ** The parser calls this routine in order to create a new VIEW

  109555. */

  109556. SQLITE_PRIVATE void sqlite3CreateView(

  109557.   Parse *pParse,     /* The parsing context */

  109558.   Token *pBegin,     /* The CREATE token that begins the statement */

  109559.   Token *pName1,     /* The token that holds the name of the view */

  109560.   Token *pName2,     /* The token that holds the name of the view */

  109561.   ExprList *pCNames, /* Optional list of view column names */

  109562.   Select *pSelect,   /* A SELECT statement that will become the new view */

  109563.   int isTemp,        /* TRUE for a TEMPORARY view */

  109564.   int noErr          /* Suppress error messages if VIEW already exists */

  109565. ){

  109566.   Table *p;

  109567.   int n;

  109568.   const char *z;

  109569.   Token sEnd;

  109570.   DbFixer sFix;

  109571.   Token *pName = 0;

  109572.   int iDb;

  109573.   sqlite3 *db = pParse->db;

  109574. 

  109575.   if( pParse->nVar>0 ){

  109576.     sqlite3ErrorMsg(pParse, "parameters are not allowed in views");

  109577.     goto create_view_fail;

  109578.   }

  109579.   sqlite3StartTable(pParse, pName1, pName2, isTemp, 1, 0, noErr);

  109580.   p = pParse->pNewTable;

  109581.   if( p==0 || pParse->nErr ) goto create_view_fail;

  109582.   sqlite3TwoPartName(pParse, pName1, pName2, &pName);

  109583.   iDb = sqlite3SchemaToIndex(db, p->pSchema);

  109584.   sqlite3FixInit(&sFix, pParse, iDb, "view", pName);

  109585.   if( sqlite3FixSelect(&sFix, pSelect) ) goto create_view_fail;

  109586. 

  109587.   /* Make a copy of the entire SELECT statement that defines the view.

  109588.   ** This will force all the Expr.token.z values to be dynamically

  109589.   ** allocated rather than point to the input string - which means that

  109590.   ** they will persist after the current sqlite3_exec() call returns.

  109591.   */

  109592.   if( IN_RENAME_OBJECT ){

  109593.     p->pSelect = pSelect;

  109594.     pSelect = 0;

  109595.   }else{

  109596.     p->pSelect = sqlite3SelectDup(db, pSelect, EXPRDUP_REDUCE);

  109597.   }

  109598.   p->pCheck = sqlite3ExprListDup(db, pCNames, EXPRDUP_REDUCE);

  109599.   if( db->mallocFailed ) goto create_view_fail;

  109600. 

  109601.   /* Locate the end of the CREATE VIEW statement.  Make sEnd point to

  109602.   ** the end.

  109603.   */

  109604.   sEnd = pParse->sLastToken;

  109605.   assert( sEnd.z[0]!=0 || sEnd.n==0 );

  109606.   if( sEnd.z[0]!=';' ){

  109607.     sEnd.z += sEnd.n;

  109608.   }

  109609.   sEnd.n = 0;

  109610.   n = (int)(sEnd.z - pBegin->z);

  109611.   assert( n>0 );

  109612.   z = pBegin->z;

  109613.   while( sqlite3Isspace(z[n-1]) ){ n--; }

  109614.   sEnd.z = &z[n-1];

  109615.   sEnd.n = 1;

  109616. 

  109617.   /* Use sqlite3EndTable() to add the view to the SQLITE_MASTER table */

  109618.   sqlite3EndTable(pParse, 0, &sEnd, 0, 0);

  109619. 

  109620. create_view_fail:

  109621.   sqlite3SelectDelete(db, pSelect);

  109622.   if( IN_RENAME_OBJECT ){

  109623.     sqlite3RenameExprlistUnmap(pParse, pCNames);

  109624.   }

  109625.   sqlite3ExprListDelete(db, pCNames);

  109626.   return;

  109627. }

  109628. #endif /* SQLITE_OMIT_VIEW */

  109629. 

  109630. #if !defined(SQLITE_OMIT_VIEW) || !defined(SQLITE_OMIT_VIRTUALTABLE)

  109631. /*

  109632. ** The Table structure pTable is really a VIEW.  Fill in the names of

  109633. ** the columns of the view in the pTable structure.  Return the number

  109634. ** of errors.  If an error is seen leave an error message in pParse->zErrMsg.

  109635. */

  109636. SQLITE_PRIVATE int sqlite3ViewGetColumnNames(Parse *pParse, Table *pTable){

  109637.   Table *pSelTab;   /* A fake table from which we get the result set */

  109638.   Select *pSel;     /* Copy of the SELECT that implements the view */

  109639.   int nErr = 0;     /* Number of errors encountered */

  109640.   int n;            /* Temporarily holds the number of cursors assigned */

  109641.   sqlite3 *db = pParse->db;  /* Database connection for malloc errors */

  109642. #ifndef SQLITE_OMIT_VIRTUALTABLE

  109643.   int rc;

  109644. #endif

  109645. #ifndef SQLITE_OMIT_AUTHORIZATION

  109646.   sqlite3_xauth xAuth;       /* Saved xAuth pointer */

  109647. #endif

  109648. 

  109649.   assert( pTable );

  109650. 

  109651. #ifndef SQLITE_OMIT_VIRTUALTABLE

  109652.   db->nSchemaLock++;

  109653.   rc = sqlite3VtabCallConnect(pParse, pTable);

  109654.   db->nSchemaLock--;

  109655.   if( rc ){

  109656.     return 1;

  109657.   }

  109658.   if( IsVirtual(pTable) ) return 0;

  109659. #endif

  109660. 

  109661. #ifndef SQLITE_OMIT_VIEW

  109662.   /* A positive nCol means the columns names for this view are

  109663.   ** already known.

  109664.   */

  109665.   if( pTable->nCol>0 ) return 0;

  109666. 

  109667.   /* A negative nCol is a special marker meaning that we are currently

  109668.   ** trying to compute the column names.  If we enter this routine with

  109669.   ** a negative nCol, it means two or more views form a loop, like this:

  109670.   **

  109671.   **     CREATE VIEW one AS SELECT * FROM two;

  109672.   **     CREATE VIEW two AS SELECT * FROM one;

  109673.   **

  109674.   ** Actually, the error above is now caught prior to reaching this point.

  109675.   ** But the following test is still important as it does come up

  109676.   ** in the following:

  109677.   ** 

  109678.   **     CREATE TABLE main.ex1(a);

  109679.   **     CREATE TEMP VIEW ex1 AS SELECT a FROM ex1;

  109680.   **     SELECT * FROM temp.ex1;

  109681.   */

  109682.   if( pTable->nCol<0 ){

  109683.     sqlite3ErrorMsg(pParse, "view %s is circularly defined", pTable->zName);

  109684.     return 1;

  109685.   }

  109686.   assert( pTable->nCol>=0 );

  109687. 

  109688.   /* If we get this far, it means we need to compute the table names.

  109689.   ** Note that the call to sqlite3ResultSetOfSelect() will expand any

  109690.   ** "*" elements in the results set of the view and will assign cursors

  109691.   ** to the elements of the FROM clause.  But we do not want these changes

  109692.   ** to be permanent.  So the computation is done on a copy of the SELECT

  109693.   ** statement that defines the view.

  109694.   */

  109695.   assert( pTable->pSelect );

  109696.   pSel = sqlite3SelectDup(db, pTable->pSelect, 0);

  109697.   if( pSel ){

  109698. #ifndef SQLITE_OMIT_ALTERTABLE

  109699.     u8 eParseMode = pParse->eParseMode;

  109700.     pParse->eParseMode = PARSE_MODE_NORMAL;

  109701. #endif

  109702.     n = pParse->nTab;

  109703.     sqlite3SrcListAssignCursors(pParse, pSel->pSrc);

  109704.     pTable->nCol = -1;

  109705.     db->lookaside.bDisable++;

  109706. #ifndef SQLITE_OMIT_AUTHORIZATION

  109707.     xAuth = db->xAuth;

  109708.     db->xAuth = 0;

  109709.     pSelTab = sqlite3ResultSetOfSelect(pParse, pSel);

  109710.     db->xAuth = xAuth;

  109711. #else

  109712.     pSelTab = sqlite3ResultSetOfSelect(pParse, pSel);

  109713. #endif

  109714.     pParse->nTab = n;

  109715.     if( pTable->pCheck ){

  109716.       /* CREATE VIEW name(arglist) AS ...

  109717.       ** The names of the columns in the table are taken from

  109718.       ** arglist which is stored in pTable->pCheck.  The pCheck field

  109719.       ** normally holds CHECK constraints on an ordinary table, but for

  109720.       ** a VIEW it holds the list of column names.

  109721.       */

  109722.       sqlite3ColumnsFromExprList(pParse, pTable->pCheck, 

  109723.                                  &pTable->nCol, &pTable->aCol);

  109724.       if( db->mallocFailed==0 

  109725.        && pParse->nErr==0

  109726.        && pTable->nCol==pSel->pEList->nExpr

  109727.       ){

  109728.         sqlite3SelectAddColumnTypeAndCollation(pParse, pTable, pSel);

  109729.       }

  109730.     }else if( pSelTab ){

  109731.       /* CREATE VIEW name AS...  without an argument list.  Construct

  109732.       ** the column names from the SELECT statement that defines the view.

  109733.       */

  109734.       assert( pTable->aCol==0 );

  109735.       pTable->nCol = pSelTab->nCol;

  109736.       pTable->aCol = pSelTab->aCol;

  109737.       pSelTab->nCol = 0;

  109738.       pSelTab->aCol = 0;

  109739.       assert( sqlite3SchemaMutexHeld(db, 0, pTable->pSchema) );

  109740.     }else{

  109741.       pTable->nCol = 0;

  109742.       nErr++;

  109743.     }

  109744.     sqlite3DeleteTable(db, pSelTab);

  109745.     sqlite3SelectDelete(db, pSel);

  109746.     db->lookaside.bDisable--;

  109747. #ifndef SQLITE_OMIT_ALTERTABLE

  109748.     pParse->eParseMode = eParseMode;

  109749. #endif

  109750.   } else {

  109751.     nErr++;

  109752.   }

  109753.   pTable->pSchema->schemaFlags |= DB_UnresetViews;

  109754.   if( db->mallocFailed ){

  109755.     sqlite3DeleteColumnNames(db, pTable);

  109756.     pTable->aCol = 0;

  109757.     pTable->nCol = 0;

  109758.   }

  109759. #endif /* SQLITE_OMIT_VIEW */

  109760.   return nErr;  

  109761. }

  109762. #endif /* !defined(SQLITE_OMIT_VIEW) || !defined(SQLITE_OMIT_VIRTUALTABLE) */

  109763. 

  109764. #ifndef SQLITE_OMIT_VIEW

  109765. /*

  109766. ** Clear the column names from every VIEW in database idx.

  109767. */

  109768. static void sqliteViewResetAll(sqlite3 *db, int idx){

  109769.   HashElem *i;

  109770.   assert( sqlite3SchemaMutexHeld(db, idx, 0) );

  109771.   if( !DbHasProperty(db, idx, DB_UnresetViews) ) return;

  109772.   for(i=sqliteHashFirst(&db->aDb[idx].pSchema->tblHash); i;i=sqliteHashNext(i)){

  109773.     Table *pTab = sqliteHashData(i);

  109774.     if( pTab->pSelect ){

  109775.       sqlite3DeleteColumnNames(db, pTab);

  109776.       pTab->aCol = 0;

  109777.       pTab->nCol = 0;

  109778.     }

  109779.   }

  109780.   DbClearProperty(db, idx, DB_UnresetViews);

  109781. }

  109782. #else

  109783. # define sqliteViewResetAll(A,B)

  109784. #endif /* SQLITE_OMIT_VIEW */

  109785. 

  109786. /*

  109787. ** This function is called by the VDBE to adjust the internal schema

  109788. ** used by SQLite when the btree layer moves a table root page. The

  109789. ** root-page of a table or index in database iDb has changed from iFrom

  109790. ** to iTo.

  109791. **

  109792. ** Ticket #1728:  The symbol table might still contain information

  109793. ** on tables and/or indices that are the process of being deleted.

  109794. ** If you are unlucky, one of those deleted indices or tables might

  109795. ** have the same rootpage number as the real table or index that is

  109796. ** being moved.  So we cannot stop searching after the first match 

  109797. ** because the first match might be for one of the deleted indices

  109798. ** or tables and not the table/index that is actually being moved.

  109799. ** We must continue looping until all tables and indices with

  109800. ** rootpage==iFrom have been converted to have a rootpage of iTo

  109801. ** in order to be certain that we got the right one.

  109802. */

  109803. #ifndef SQLITE_OMIT_AUTOVACUUM

  109804. SQLITE_PRIVATE void sqlite3RootPageMoved(sqlite3 *db, int iDb, int iFrom, int iTo){

  109805.   HashElem *pElem;

  109806.   Hash *pHash;

  109807.   Db *pDb;

  109808. 

  109809.   assert( sqlite3SchemaMutexHeld(db, iDb, 0) );

  109810.   pDb = &db->aDb[iDb];

  109811.   pHash = &pDb->pSchema->tblHash;

  109812.   for(pElem=sqliteHashFirst(pHash); pElem; pElem=sqliteHashNext(pElem)){

  109813.     Table *pTab = sqliteHashData(pElem);

  109814.     if( pTab->tnum==iFrom ){

  109815.       pTab->tnum = iTo;

  109816.     }

  109817.   }

  109818.   pHash = &pDb->pSchema->idxHash;

  109819.   for(pElem=sqliteHashFirst(pHash); pElem; pElem=sqliteHashNext(pElem)){

  109820.     Index *pIdx = sqliteHashData(pElem);

  109821.     if( pIdx->tnum==iFrom ){

  109822.       pIdx->tnum = iTo;

  109823.     }

  109824.   }

  109825. }

  109826. #endif

  109827. 

  109828. /*

  109829. ** Write code to erase the table with root-page iTable from database iDb.

  109830. ** Also write code to modify the sqlite_master table and internal schema

  109831. ** if a root-page of another table is moved by the btree-layer whilst

  109832. ** erasing iTable (this can happen with an auto-vacuum database).

  109833. */ 

  109834. static void destroyRootPage(Parse *pParse, int iTable, int iDb){

  109835.   Vdbe *v = sqlite3GetVdbe(pParse);

  109836.   int r1 = sqlite3GetTempReg(pParse);

  109837.   if( iTable<2 ) sqlite3ErrorMsg(pParse, "corrupt schema");

  109838.   sqlite3VdbeAddOp3(v, OP_Destroy, iTable, r1, iDb);

  109839.   sqlite3MayAbort(pParse);

  109840. #ifndef SQLITE_OMIT_AUTOVACUUM

  109841.   /* OP_Destroy stores an in integer r1. If this integer

  109842.   ** is non-zero, then it is the root page number of a table moved to

  109843.   ** location iTable. The following code modifies the sqlite_master table to

  109844.   ** reflect this.

  109845.   **

  109846.   ** The "#NNN" in the SQL is a special constant that means whatever value

  109847.   ** is in register NNN.  See grammar rules associated with the TK_REGISTER

  109848.   ** token for additional information.

  109849.   */

  109850.   sqlite3NestedParse(pParse, 

  109851.      "UPDATE %Q.%s SET rootpage=%d WHERE #%d AND rootpage=#%d",

  109852.      pParse->db->aDb[iDb].zDbSName, MASTER_NAME, iTable, r1, r1);

  109853. #endif

  109854.   sqlite3ReleaseTempReg(pParse, r1);

  109855. }

  109856. 

  109857. /*

  109858. ** Write VDBE code to erase table pTab and all associated indices on disk.

  109859. ** Code to update the sqlite_master tables and internal schema definitions

  109860. ** in case a root-page belonging to another table is moved by the btree layer

  109861. ** is also added (this can happen with an auto-vacuum database).

  109862. */

  109863. static void destroyTable(Parse *pParse, Table *pTab){

  109864.   /* If the database may be auto-vacuum capable (if SQLITE_OMIT_AUTOVACUUM

  109865.   ** is not defined), then it is important to call OP_Destroy on the

  109866.   ** table and index root-pages in order, starting with the numerically 

  109867.   ** largest root-page number. This guarantees that none of the root-pages

  109868.   ** to be destroyed is relocated by an earlier OP_Destroy. i.e. if the

  109869.   ** following were coded:

  109870.   **

  109871.   ** OP_Destroy 4 0

  109872.   ** ...

  109873.   ** OP_Destroy 5 0

  109874.   **

  109875.   ** and root page 5 happened to be the largest root-page number in the

  109876.   ** database, then root page 5 would be moved to page 4 by the 

  109877.   ** "OP_Destroy 4 0" opcode. The subsequent "OP_Destroy 5 0" would hit

  109878.   ** a free-list page.

  109879.   */

  109880.   int iTab = pTab->tnum;

  109881.   int iDestroyed = 0;

  109882. 

  109883.   while( 1 ){

  109884.     Index *pIdx;

  109885.     int iLargest = 0;

  109886. 

  109887.     if( iDestroyed==0 || iTab<iDestroyed ){

  109888.       iLargest = iTab;

  109889.     }

  109890.     for(pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext){

  109891.       int iIdx = pIdx->tnum;

  109892.       assert( pIdx->pSchema==pTab->pSchema );

  109893.       if( (iDestroyed==0 || (iIdx<iDestroyed)) && iIdx>iLargest ){

  109894.         iLargest = iIdx;

  109895.       }

  109896.     }

  109897.     if( iLargest==0 ){

  109898.       return;

  109899.     }else{

  109900.       int iDb = sqlite3SchemaToIndex(pParse->db, pTab->pSchema);

  109901.       assert( iDb>=0 && iDb<pParse->db->nDb );

  109902.       destroyRootPage(pParse, iLargest, iDb);

  109903.       iDestroyed = iLargest;

  109904.     }

  109905.   }

  109906. }

  109907. 

  109908. /*

  109909. ** Remove entries from the sqlite_statN tables (for N in (1,2,3))

  109910. ** after a DROP INDEX or DROP TABLE command.

  109911. */

  109912. static void sqlite3ClearStatTables(

  109913.   Parse *pParse,         /* The parsing context */

  109914.   int iDb,               /* The database number */

  109915.   const char *zType,     /* "idx" or "tbl" */

  109916.   const char *zName      /* Name of index or table */

  109917. ){

  109918.   int i;

  109919.   const char *zDbName = pParse->db->aDb[iDb].zDbSName;

  109920.   for(i=1; i<=4; i++){

  109921.     char zTab[24];

  109922.     sqlite3_snprintf(sizeof(zTab),zTab,"sqlite_stat%d",i);

  109923.     if( sqlite3FindTable(pParse->db, zTab, zDbName) ){

  109924.       sqlite3NestedParse(pParse,

  109925.         "DELETE FROM %Q.%s WHERE %s=%Q",

  109926.         zDbName, zTab, zType, zName

  109927.       );

  109928.     }

  109929.   }

  109930. }

  109931. 

  109932. /*

  109933. ** Generate code to drop a table.

  109934. */

  109935. SQLITE_PRIVATE void sqlite3CodeDropTable(Parse *pParse, Table *pTab, int iDb, int isView){

  109936.   Vdbe *v;

  109937.   sqlite3 *db = pParse->db;

  109938.   Trigger *pTrigger;

  109939.   Db *pDb = &db->aDb[iDb];

  109940. 

  109941.   v = sqlite3GetVdbe(pParse);

  109942.   assert( v!=0 );

  109943.   sqlite3BeginWriteOperation(pParse, 1, iDb);

  109944. 

  109945. #ifndef SQLITE_OMIT_VIRTUALTABLE

  109946.   if( IsVirtual(pTab) ){

  109947.     sqlite3VdbeAddOp0(v, OP_VBegin);

  109948.   }

  109949. #endif

  109950. 

  109951.   /* Drop all triggers associated with the table being dropped. Code

  109952.   ** is generated to remove entries from sqlite_master and/or

  109953.   ** sqlite_temp_master if required.

  109954.   */

  109955.   pTrigger = sqlite3TriggerList(pParse, pTab);

  109956.   while( pTrigger ){

  109957.     assert( pTrigger->pSchema==pTab->pSchema || 

  109958.         pTrigger->pSchema==db->aDb[1].pSchema );

  109959.     sqlite3DropTriggerPtr(pParse, pTrigger);

  109960.     pTrigger = pTrigger->pNext;

  109961.   }

  109962. 

  109963. #ifndef SQLITE_OMIT_AUTOINCREMENT

  109964.   /* Remove any entries of the sqlite_sequence table associated with

  109965.   ** the table being dropped. This is done before the table is dropped

  109966.   ** at the btree level, in case the sqlite_sequence table needs to

  109967.   ** move as a result of the drop (can happen in auto-vacuum mode).

  109968.   */

  109969.   if( pTab->tabFlags & TF_Autoincrement ){

  109970.     sqlite3NestedParse(pParse,

  109971.       "DELETE FROM %Q.sqlite_sequence WHERE name=%Q",

  109972.       pDb->zDbSName, pTab->zName

  109973.     );

  109974.   }

  109975. #endif

  109976. 

  109977.   /* Drop all SQLITE_MASTER table and index entries that refer to the

  109978.   ** table. The program name loops through the master table and deletes

  109979.   ** every row that refers to a table of the same name as the one being

  109980.   ** dropped. Triggers are handled separately because a trigger can be

  109981.   ** created in the temp database that refers to a table in another

  109982.   ** database.

  109983.   */

  109984.   sqlite3NestedParse(pParse, 

  109985.       "DELETE FROM %Q.%s WHERE tbl_name=%Q and type!='trigger'",

  109986.       pDb->zDbSName, MASTER_NAME, pTab->zName);

  109987.   if( !isView && !IsVirtual(pTab) ){

  109988.     destroyTable(pParse, pTab);

  109989.   }

  109990. 

  109991.   /* Remove the table entry from SQLite's internal schema and modify

  109992.   ** the schema cookie.

  109993.   */

  109994.   if( IsVirtual(pTab) ){

  109995.     sqlite3VdbeAddOp4(v, OP_VDestroy, iDb, 0, 0, pTab->zName, 0);

  109996.     sqlite3MayAbort(pParse);

  109997.   }

  109998.   sqlite3VdbeAddOp4(v, OP_DropTable, iDb, 0, 0, pTab->zName, 0);

  109999.   sqlite3ChangeCookie(pParse, iDb);

  110000.   sqliteViewResetAll(db, iDb);

  110001. }

  110002. 

  110003. /*

  110004. ** This routine is called to do the work of a DROP TABLE statement.

  110005. ** pName is the name of the table to be dropped.

  110006. */

  110007. SQLITE_PRIVATE void sqlite3DropTable(Parse *pParse, SrcList *pName, int isView, int noErr){

  110008.   Table *pTab;

  110009.   Vdbe *v;

  110010.   sqlite3 *db = pParse->db;

  110011.   int iDb;

  110012. 

  110013.   if( db->mallocFailed ){

  110014.     goto exit_drop_table;

  110015.   }

  110016.   assert( pParse->nErr==0 );

  110017.   assert( pName->nSrc==1 );

  110018.   if( sqlite3ReadSchema(pParse) ) goto exit_drop_table;

  110019.   if( noErr ) db->suppressErr++;

  110020.   assert( isView==0 || isView==LOCATE_VIEW );

  110021.   pTab = sqlite3LocateTableItem(pParse, isView, &pName->a[0]);

  110022.   if( noErr ) db->suppressErr--;

  110023. 

  110024.   if( pTab==0 ){

  110025.     if( noErr ) sqlite3CodeVerifyNamedSchema(pParse, pName->a[0].zDatabase);

  110026.     goto exit_drop_table;

  110027.   }

  110028.   iDb = sqlite3SchemaToIndex(db, pTab->pSchema);

  110029.   assert( iDb>=0 && iDb<db->nDb );

  110030. 

  110031.   /* If pTab is a virtual table, call ViewGetColumnNames() to ensure

  110032.   ** it is initialized.

  110033.   */

  110034.   if( IsVirtual(pTab) && sqlite3ViewGetColumnNames(pParse, pTab) ){

  110035.     goto exit_drop_table;

  110036.   }

  110037. #ifndef SQLITE_OMIT_AUTHORIZATION

  110038.   {

  110039.     int code;

  110040.     const char *zTab = SCHEMA_TABLE(iDb);

  110041.     const char *zDb = db->aDb[iDb].zDbSName;

  110042.     const char *zArg2 = 0;

  110043.     if( sqlite3AuthCheck(pParse, SQLITE_DELETE, zTab, 0, zDb)){

  110044.       goto exit_drop_table;

  110045.     }

  110046.     if( isView ){

  110047.       if( !OMIT_TEMPDB && iDb==1 ){

  110048.         code = SQLITE_DROP_TEMP_VIEW;

  110049.       }else{

  110050.         code = SQLITE_DROP_VIEW;

  110051.       }

  110052. #ifndef SQLITE_OMIT_VIRTUALTABLE

  110053.     }else if( IsVirtual(pTab) ){

  110054.       code = SQLITE_DROP_VTABLE;

  110055.       zArg2 = sqlite3GetVTable(db, pTab)->pMod->zName;

  110056. #endif

  110057.     }else{

  110058.       if( !OMIT_TEMPDB && iDb==1 ){

  110059.         code = SQLITE_DROP_TEMP_TABLE;

  110060.       }else{

  110061.         code = SQLITE_DROP_TABLE;

  110062.       }

  110063.     }

  110064.     if( sqlite3AuthCheck(pParse, code, pTab->zName, zArg2, zDb) ){

  110065.       goto exit_drop_table;

  110066.     }

  110067.     if( sqlite3AuthCheck(pParse, SQLITE_DELETE, pTab->zName, 0, zDb) ){

  110068.       goto exit_drop_table;

  110069.     }

  110070.   }

  110071. #endif

  110072.   if( sqlite3StrNICmp(pTab->zName, "sqlite_", 7)==0 

  110073.     && sqlite3StrNICmp(pTab->zName, "sqlite_stat", 11)!=0 ){

  110074.     sqlite3ErrorMsg(pParse, "table %s may not be dropped", pTab->zName);

  110075.     goto exit_drop_table;

  110076.   }

  110077. 

  110078. #ifndef SQLITE_OMIT_VIEW

  110079.   /* Ensure DROP TABLE is not used on a view, and DROP VIEW is not used

  110080.   ** on a table.

  110081.   */

  110082.   if( isView && pTab->pSelect==0 ){

  110083.     sqlite3ErrorMsg(pParse, "use DROP TABLE to delete table %s", pTab->zName);

  110084.     goto exit_drop_table;

  110085.   }

  110086.   if( !isView && pTab->pSelect ){

  110087.     sqlite3ErrorMsg(pParse, "use DROP VIEW to delete view %s", pTab->zName);

  110088.     goto exit_drop_table;

  110089.   }

  110090. #endif

  110091. 

  110092.   /* Generate code to remove the table from the master table

  110093.   ** on disk.

  110094.   */

  110095.   v = sqlite3GetVdbe(pParse);

  110096.   if( v ){

  110097.     sqlite3BeginWriteOperation(pParse, 1, iDb);

  110098.     if( !isView ){

  110099.       sqlite3ClearStatTables(pParse, iDb, "tbl", pTab->zName);

  110100.       sqlite3FkDropTable(pParse, pName, pTab);

  110101.     }

  110102.     sqlite3CodeDropTable(pParse, pTab, iDb, isView);

  110103.   }

  110104. 

  110105. exit_drop_table:

  110106.   sqlite3SrcListDelete(db, pName);

  110107. }

  110108. 

  110109. /*

  110110. ** This routine is called to create a new foreign key on the table

  110111. ** currently under construction.  pFromCol determines which columns

  110112. ** in the current table point to the foreign key.  If pFromCol==0 then

  110113. ** connect the key to the last column inserted.  pTo is the name of

  110114. ** the table referred to (a.k.a the "parent" table).  pToCol is a list

  110115. ** of tables in the parent pTo table.  flags contains all

  110116. ** information about the conflict resolution algorithms specified

  110117. ** in the ON DELETE, ON UPDATE and ON INSERT clauses.

  110118. **

  110119. ** An FKey structure is created and added to the table currently

  110120. ** under construction in the pParse->pNewTable field.

  110121. **

  110122. ** The foreign key is set for IMMEDIATE processing.  A subsequent call

  110123. ** to sqlite3DeferForeignKey() might change this to DEFERRED.

  110124. */

  110125. SQLITE_PRIVATE void sqlite3CreateForeignKey(

  110126.   Parse *pParse,       /* Parsing context */

  110127.   ExprList *pFromCol,  /* Columns in this table that point to other table */

  110128.   Token *pTo,          /* Name of the other table */

  110129.   ExprList *pToCol,    /* Columns in the other table */

  110130.   int flags            /* Conflict resolution algorithms. */

  110131. ){

  110132.   sqlite3 *db = pParse->db;

  110133. #ifndef SQLITE_OMIT_FOREIGN_KEY

  110134.   FKey *pFKey = 0;

  110135.   FKey *pNextTo;

  110136.   Table *p = pParse->pNewTable;

  110137.   int nByte;

  110138.   int i;

  110139.   int nCol;

  110140.   char *z;

  110141. 

  110142.   assert( pTo!=0 );

  110143.   if( p==0 || IN_DECLARE_VTAB ) goto fk_end;

  110144.   if( pFromCol==0 ){

  110145.     int iCol = p->nCol-1;

  110146.     if( NEVER(iCol<0) ) goto fk_end;

  110147.     if( pToCol && pToCol->nExpr!=1 ){

  110148.       sqlite3ErrorMsg(pParse, "foreign key on %s"

  110149.          " should reference only one column of table %T",

  110150.          p->aCol[iCol].zName, pTo);

  110151.       goto fk_end;

  110152.     }

  110153.     nCol = 1;

  110154.   }else if( pToCol && pToCol->nExpr!=pFromCol->nExpr ){

  110155.     sqlite3ErrorMsg(pParse,

  110156.         "number of columns in foreign key does not match the number of "

  110157.         "columns in the referenced table");

  110158.     goto fk_end;

  110159.   }else{

  110160.     nCol = pFromCol->nExpr;

  110161.   }

  110162.   nByte = sizeof(*pFKey) + (nCol-1)*sizeof(pFKey->aCol[0]) + pTo->n + 1;

  110163.   if( pToCol ){

  110164.     for(i=0; i<pToCol->nExpr; i++){

  110165.       nByte += sqlite3Strlen30(pToCol->a[i].zName) + 1;

  110166.     }

  110167.   }

  110168.   pFKey = sqlite3DbMallocZero(db, nByte );

  110169.   if( pFKey==0 ){

  110170.     goto fk_end;

  110171.   }

  110172.   pFKey->pFrom = p;

  110173.   pFKey->pNextFrom = p->pFKey;

  110174.   z = (char*)&pFKey->aCol[nCol];

  110175.   pFKey->zTo = z;

  110176.   if( IN_RENAME_OBJECT ){

  110177.     sqlite3RenameTokenMap(pParse, (void*)z, pTo);

  110178.   }

  110179.   memcpy(z, pTo->z, pTo->n);

  110180.   z[pTo->n] = 0;

  110181.   sqlite3Dequote(z);

  110182.   z += pTo->n+1;

  110183.   pFKey->nCol = nCol;

  110184.   if( pFromCol==0 ){

  110185.     pFKey->aCol[0].iFrom = p->nCol-1;

  110186.   }else{

  110187.     for(i=0; i<nCol; i++){

  110188.       int j;

  110189.       for(j=0; j<p->nCol; j++){

  110190.         if( sqlite3StrICmp(p->aCol[j].zName, pFromCol->a[i].zName)==0 ){

  110191.           pFKey->aCol[i].iFrom = j;

  110192.           break;

  110193.         }

  110194.       }

  110195.       if( j>=p->nCol ){

  110196.         sqlite3ErrorMsg(pParse, 

  110197.           "unknown column \"%s\" in foreign key definition", 

  110198.           pFromCol->a[i].zName);

  110199.         goto fk_end;

  110200.       }

  110201.       if( IN_RENAME_OBJECT ){

  110202.         sqlite3RenameTokenRemap(pParse, &pFKey->aCol[i], pFromCol->a[i].zName);

  110203.       }

  110204.     }

  110205.   }

  110206.   if( pToCol ){

  110207.     for(i=0; i<nCol; i++){

  110208.       int n = sqlite3Strlen30(pToCol->a[i].zName);

  110209.       pFKey->aCol[i].zCol = z;

  110210.       if( IN_RENAME_OBJECT ){

  110211.         sqlite3RenameTokenRemap(pParse, z, pToCol->a[i].zName);

  110212.       }

  110213.       memcpy(z, pToCol->a[i].zName, n);

  110214.       z[n] = 0;

  110215.       z += n+1;

  110216.     }

  110217.   }

  110218.   pFKey->isDeferred = 0;

  110219.   pFKey->aAction[0] = (u8)(flags & 0xff);            /* ON DELETE action */

  110220.   pFKey->aAction[1] = (u8)((flags >> 8 ) & 0xff);    /* ON UPDATE action */

  110221. 

  110222.   assert( sqlite3SchemaMutexHeld(db, 0, p->pSchema) );

  110223.   pNextTo = (FKey *)sqlite3HashInsert(&p->pSchema->fkeyHash, 

  110224.       pFKey->zTo, (void *)pFKey

  110225.   );

  110226.   if( pNextTo==pFKey ){

  110227.     sqlite3OomFault(db);

  110228.     goto fk_end;

  110229.   }

  110230.   if( pNextTo ){

  110231.     assert( pNextTo->pPrevTo==0 );

  110232.     pFKey->pNextTo = pNextTo;

  110233.     pNextTo->pPrevTo = pFKey;

  110234.   }

  110235. 

  110236.   /* Link the foreign key to the table as the last step.

  110237.   */

  110238.   p->pFKey = pFKey;

  110239.   pFKey = 0;

  110240. 

  110241. fk_end:

  110242.   sqlite3DbFree(db, pFKey);

  110243. #endif /* !defined(SQLITE_OMIT_FOREIGN_KEY) */

  110244.   sqlite3ExprListDelete(db, pFromCol);

  110245.   sqlite3ExprListDelete(db, pToCol);

  110246. }

  110247. 

  110248. /*

  110249. ** This routine is called when an INITIALLY IMMEDIATE or INITIALLY DEFERRED

  110250. ** clause is seen as part of a foreign key definition.  The isDeferred

  110251. ** parameter is 1 for INITIALLY DEFERRED and 0 for INITIALLY IMMEDIATE.

  110252. ** The behavior of the most recently created foreign key is adjusted

  110253. ** accordingly.

  110254. */

  110255. SQLITE_PRIVATE void sqlite3DeferForeignKey(Parse *pParse, int isDeferred){

  110256. #ifndef SQLITE_OMIT_FOREIGN_KEY

  110257.   Table *pTab;

  110258.   FKey *pFKey;

  110259.   if( (pTab = pParse->pNewTable)==0 || (pFKey = pTab->pFKey)==0 ) return;

  110260.   assert( isDeferred==0 || isDeferred==1 ); /* EV: R-30323-21917 */

  110261.   pFKey->isDeferred = (u8)isDeferred;

  110262. #endif

  110263. }

  110264. 

  110265. /*

  110266. ** Generate code that will erase and refill index *pIdx.  This is

  110267. ** used to initialize a newly created index or to recompute the

  110268. ** content of an index in response to a REINDEX command.

  110269. **

  110270. ** if memRootPage is not negative, it means that the index is newly

  110271. ** created.  The register specified by memRootPage contains the

  110272. ** root page number of the index.  If memRootPage is negative, then

  110273. ** the index already exists and must be cleared before being refilled and

  110274. ** the root page number of the index is taken from pIndex->tnum.

  110275. */

  110276. static void sqlite3RefillIndex(Parse *pParse, Index *pIndex, int memRootPage){

  110277.   Table *pTab = pIndex->pTable;  /* The table that is indexed */

  110278.   int iTab = pParse->nTab++;     /* Btree cursor used for pTab */

  110279.   int iIdx = pParse->nTab++;     /* Btree cursor used for pIndex */

  110280.   int iSorter;                   /* Cursor opened by OpenSorter (if in use) */

  110281.   int addr1;                     /* Address of top of loop */

  110282.   int addr2;                     /* Address to jump to for next iteration */

  110283.   int tnum;                      /* Root page of index */

  110284.   int iPartIdxLabel;             /* Jump to this label to skip a row */

  110285.   Vdbe *v;                       /* Generate code into this virtual machine */

  110286.   KeyInfo *pKey;                 /* KeyInfo for index */

  110287.   int regRecord;                 /* Register holding assembled index record */

  110288.   sqlite3 *db = pParse->db;      /* The database connection */

  110289.   int iDb = sqlite3SchemaToIndex(db, pIndex->pSchema);

  110290. 

  110291. #ifndef SQLITE_OMIT_AUTHORIZATION

  110292.   if( sqlite3AuthCheck(pParse, SQLITE_REINDEX, pIndex->zName, 0,

  110293.       db->aDb[iDb].zDbSName ) ){

  110294.     return;

  110295.   }

  110296. #endif

  110297. 

  110298.   /* Require a write-lock on the table to perform this operation */

  110299.   sqlite3TableLock(pParse, iDb, pTab->tnum, 1, pTab->zName);

  110300. 

  110301.   v = sqlite3GetVdbe(pParse);

  110302.   if( v==0 ) return;

  110303.   if( memRootPage>=0 ){

  110304.     tnum = memRootPage;

  110305.   }else{

  110306.     tnum = pIndex->tnum;

  110307.   }

  110308.   pKey = sqlite3KeyInfoOfIndex(pParse, pIndex);

  110309.   assert( pKey!=0 || db->mallocFailed || pParse->nErr );

  110310. 

  110311.   /* Open the sorter cursor if we are to use one. */

  110312.   iSorter = pParse->nTab++;

  110313.   sqlite3VdbeAddOp4(v, OP_SorterOpen, iSorter, 0, pIndex->nKeyCol, (char*)

  110314.                     sqlite3KeyInfoRef(pKey), P4_KEYINFO);

  110315. 

  110316.   /* Open the table. Loop through all rows of the table, inserting index

  110317.   ** records into the sorter. */

  110318.   sqlite3OpenTable(pParse, iTab, iDb, pTab, OP_OpenRead);

  110319.   addr1 = sqlite3VdbeAddOp2(v, OP_Rewind, iTab, 0); VdbeCoverage(v);

  110320.   regRecord = sqlite3GetTempReg(pParse);

  110321.   sqlite3MultiWrite(pParse);

  110322. 

  110323.   sqlite3GenerateIndexKey(pParse,pIndex,iTab,regRecord,0,&iPartIdxLabel,0,0);

  110324.   sqlite3VdbeAddOp2(v, OP_SorterInsert, iSorter, regRecord);

  110325.   sqlite3ResolvePartIdxLabel(pParse, iPartIdxLabel);

  110326.   sqlite3VdbeAddOp2(v, OP_Next, iTab, addr1+1); VdbeCoverage(v);

  110327.   sqlite3VdbeJumpHere(v, addr1);

  110328.   if( memRootPage<0 ) sqlite3VdbeAddOp2(v, OP_Clear, tnum, iDb);

  110329.   sqlite3VdbeAddOp4(v, OP_OpenWrite, iIdx, tnum, iDb, 

  110330.                     (char *)pKey, P4_KEYINFO);

  110331.   sqlite3VdbeChangeP5(v, OPFLAG_BULKCSR|((memRootPage>=0)?OPFLAG_P2ISREG:0));

  110332. 

  110333.   addr1 = sqlite3VdbeAddOp2(v, OP_SorterSort, iSorter, 0); VdbeCoverage(v);

  110334.   if( IsUniqueIndex(pIndex) ){

  110335.     int j2 = sqlite3VdbeGoto(v, 1);

  110336.     addr2 = sqlite3VdbeCurrentAddr(v);

  110337.     sqlite3VdbeVerifyAbortable(v, OE_Abort);

  110338.     sqlite3VdbeAddOp4Int(v, OP_SorterCompare, iSorter, j2, regRecord,

  110339.                          pIndex->nKeyCol); VdbeCoverage(v);

  110340.     sqlite3UniqueConstraint(pParse, OE_Abort, pIndex);

  110341.     sqlite3VdbeJumpHere(v, j2);

  110342.   }else{

  110343.     /* Most CREATE INDEX and REINDEX statements that are not UNIQUE can not

  110344.     ** abort. The exception is if one of the indexed expressions contains a

  110345.     ** user function that throws an exception when it is evaluated. But the

  110346.     ** overhead of adding a statement journal to a CREATE INDEX statement is

  110347.     ** very small (since most of the pages written do not contain content that

  110348.     ** needs to be restored if the statement aborts), so we call 

  110349.     ** sqlite3MayAbort() for all CREATE INDEX statements.  */

  110350.     sqlite3MayAbort(pParse);

  110351.     addr2 = sqlite3VdbeCurrentAddr(v);

  110352.   }

  110353.   sqlite3VdbeAddOp3(v, OP_SorterData, iSorter, regRecord, iIdx);

  110354.   if( !pIndex->bAscKeyBug ){

  110355.     /* This OP_SeekEnd opcode makes index insert for a REINDEX go much

  110356.     ** faster by avoiding unnecessary seeks.  But the optimization does

  110357.     ** not work for UNIQUE constraint indexes on WITHOUT ROWID tables

  110358.     ** with DESC primary keys, since those indexes have there keys in

  110359.     ** a different order from the main table.

  110360.     ** See ticket: https://www.sqlite.org/src/info/bba7b69f9849b5bf

  110361.     */

  110362.     sqlite3VdbeAddOp1(v, OP_SeekEnd, iIdx);

  110363.   }

  110364.   sqlite3VdbeAddOp2(v, OP_IdxInsert, iIdx, regRecord);

  110365.   sqlite3VdbeChangeP5(v, OPFLAG_USESEEKRESULT);

  110366.   sqlite3ReleaseTempReg(pParse, regRecord);

  110367.   sqlite3VdbeAddOp2(v, OP_SorterNext, iSorter, addr2); VdbeCoverage(v);

  110368.   sqlite3VdbeJumpHere(v, addr1);

  110369. 

  110370.   sqlite3VdbeAddOp1(v, OP_Close, iTab);

  110371.   sqlite3VdbeAddOp1(v, OP_Close, iIdx);

  110372.   sqlite3VdbeAddOp1(v, OP_Close, iSorter);

  110373. }

  110374. 

  110375. /*

  110376. ** Allocate heap space to hold an Index object with nCol columns.

  110377. **

  110378. ** Increase the allocation size to provide an extra nExtra bytes

  110379. ** of 8-byte aligned space after the Index object and return a

  110380. ** pointer to this extra space in *ppExtra.

  110381. */

  110382. SQLITE_PRIVATE Index *sqlite3AllocateIndexObject(

  110383.   sqlite3 *db,         /* Database connection */

  110384.   i16 nCol,            /* Total number of columns in the index */

  110385.   int nExtra,          /* Number of bytes of extra space to alloc */

  110386.   char **ppExtra       /* Pointer to the "extra" space */

  110387. ){

  110388.   Index *p;            /* Allocated index object */

  110389.   int nByte;           /* Bytes of space for Index object + arrays */

  110390. 

  110391.   nByte = ROUND8(sizeof(Index)) +              /* Index structure  */

  110392.           ROUND8(sizeof(char*)*nCol) +         /* Index.azColl     */

  110393.           ROUND8(sizeof(LogEst)*(nCol+1) +     /* Index.aiRowLogEst   */

  110394.                  sizeof(i16)*nCol +            /* Index.aiColumn   */

  110395.                  sizeof(u8)*nCol);             /* Index.aSortOrder */

  110396.   p = sqlite3DbMallocZero(db, nByte + nExtra);

  110397.   if( p ){

  110398.     char *pExtra = ((char*)p)+ROUND8(sizeof(Index));

  110399.     p->azColl = (const char**)pExtra; pExtra += ROUND8(sizeof(char*)*nCol);

  110400.     p->aiRowLogEst = (LogEst*)pExtra; pExtra += sizeof(LogEst)*(nCol+1);

  110401.     p->aiColumn = (i16*)pExtra;       pExtra += sizeof(i16)*nCol;

  110402.     p->aSortOrder = (u8*)pExtra;

  110403.     p->nColumn = nCol;

  110404.     p->nKeyCol = nCol - 1;

  110405.     *ppExtra = ((char*)p) + nByte;

  110406.   }

  110407.   return p;

  110408. }

  110409. 

  110410. /*

  110411. ** Create a new index for an SQL table.  pName1.pName2 is the name of the index 

  110412. ** and pTblList is the name of the table that is to be indexed.  Both will 

  110413. ** be NULL for a primary key or an index that is created to satisfy a

  110414. ** UNIQUE constraint.  If pTable and pIndex are NULL, use pParse->pNewTable

  110415. ** as the table to be indexed.  pParse->pNewTable is a table that is

  110416. ** currently being constructed by a CREATE TABLE statement.

  110417. **

  110418. ** pList is a list of columns to be indexed.  pList will be NULL if this

  110419. ** is a primary key or unique-constraint on the most recent column added

  110420. ** to the table currently under construction.  

  110421. */

  110422. SQLITE_PRIVATE void sqlite3CreateIndex(

  110423.   Parse *pParse,     /* All information about this parse */

  110424.   Token *pName1,     /* First part of index name. May be NULL */

  110425.   Token *pName2,     /* Second part of index name. May be NULL */

  110426.   SrcList *pTblName, /* Table to index. Use pParse->pNewTable if 0 */

  110427.   ExprList *pList,   /* A list of columns to be indexed */

  110428.   int onError,       /* OE_Abort, OE_Ignore, OE_Replace, or OE_None */

  110429.   Token *pStart,     /* The CREATE token that begins this statement */

  110430.   Expr *pPIWhere,    /* WHERE clause for partial indices */

  110431.   int sortOrder,     /* Sort order of primary key when pList==NULL */

  110432.   int ifNotExist,    /* Omit error if index already exists */

  110433.   u8 idxType         /* The index type */

  110434. ){

  110435.   Table *pTab = 0;     /* Table to be indexed */

  110436.   Index *pIndex = 0;   /* The index to be created */

  110437.   char *zName = 0;     /* Name of the index */

  110438.   int nName;           /* Number of characters in zName */

  110439.   int i, j;

  110440.   DbFixer sFix;        /* For assigning database names to pTable */

  110441.   int sortOrderMask;   /* 1 to honor DESC in index.  0 to ignore. */

  110442.   sqlite3 *db = pParse->db;

  110443.   Db *pDb;             /* The specific table containing the indexed database */

  110444.   int iDb;             /* Index of the database that is being written */

  110445.   Token *pName = 0;    /* Unqualified name of the index to create */

  110446.   struct ExprList_item *pListItem; /* For looping over pList */

  110447.   int nExtra = 0;                  /* Space allocated for zExtra[] */

  110448.   int nExtraCol;                   /* Number of extra columns needed */

  110449.   char *zExtra = 0;                /* Extra space after the Index object */

  110450.   Index *pPk = 0;      /* PRIMARY KEY index for WITHOUT ROWID tables */

  110451. 

  110452.   if( db->mallocFailed || pParse->nErr>0 ){

  110453.     goto exit_create_index;

  110454.   }

  110455.   if( IN_DECLARE_VTAB && idxType!=SQLITE_IDXTYPE_PRIMARYKEY ){

  110456.     goto exit_create_index;

  110457.   }

  110458.   if( SQLITE_OK!=sqlite3ReadSchema(pParse) ){

  110459.     goto exit_create_index;

  110460.   }

  110461. 

  110462.   /*

  110463.   ** Find the table that is to be indexed.  Return early if not found.

  110464.   */

  110465.   if( pTblName!=0 ){

  110466. 

  110467.     /* Use the two-part index name to determine the database 

  110468.     ** to search for the table. 'Fix' the table name to this db

  110469.     ** before looking up the table.

  110470.     */

  110471.     assert( pName1 && pName2 );

  110472.     iDb = sqlite3TwoPartName(pParse, pName1, pName2, &pName);

  110473.     if( iDb<0 ) goto exit_create_index;

  110474.     assert( pName && pName->z );

  110475. 

  110476. #ifndef SQLITE_OMIT_TEMPDB

  110477.     /* If the index name was unqualified, check if the table

  110478.     ** is a temp table. If so, set the database to 1. Do not do this

  110479.     ** if initialising a database schema.

  110480.     */

  110481.     if( !db->init.busy ){

  110482.       pTab = sqlite3SrcListLookup(pParse, pTblName);

  110483.       if( pName2->n==0 && pTab && pTab->pSchema==db->aDb[1].pSchema ){

  110484.         iDb = 1;

  110485.       }

  110486.     }

  110487. #endif

  110488. 

  110489.     sqlite3FixInit(&sFix, pParse, iDb, "index", pName);

  110490.     if( sqlite3FixSrcList(&sFix, pTblName) ){

  110491.       /* Because the parser constructs pTblName from a single identifier,

  110492.       ** sqlite3FixSrcList can never fail. */

  110493.       assert(0);

  110494.     }

  110495.     pTab = sqlite3LocateTableItem(pParse, 0, &pTblName->a[0]);

  110496.     assert( db->mallocFailed==0 || pTab==0 );

  110497.     if( pTab==0 ) goto exit_create_index;

  110498.     if( iDb==1 && db->aDb[iDb].pSchema!=pTab->pSchema ){

  110499.       sqlite3ErrorMsg(pParse, 

  110500.            "cannot create a TEMP index on non-TEMP table \"%s\"",

  110501.            pTab->zName);

  110502.       goto exit_create_index;

  110503.     }

  110504.     if( !HasRowid(pTab) ) pPk = sqlite3PrimaryKeyIndex(pTab);

  110505.   }else{

  110506.     assert( pName==0 );

  110507.     assert( pStart==0 );

  110508.     pTab = pParse->pNewTable;

  110509.     if( !pTab ) goto exit_create_index;

  110510.     iDb = sqlite3SchemaToIndex(db, pTab->pSchema);

  110511.   }

  110512.   pDb = &db->aDb[iDb];

  110513. 

  110514.   assert( pTab!=0 );

  110515.   assert( pParse->nErr==0 );

  110516.   if( sqlite3StrNICmp(pTab->zName, "sqlite_", 7)==0 

  110517.        && db->init.busy==0

  110518.        && pTblName!=0

  110519. #if SQLITE_USER_AUTHENTICATION

  110520.        && sqlite3UserAuthTable(pTab->zName)==0

  110521. #endif

  110522. #ifdef SQLITE_ALLOW_SQLITE_MASTER_INDEX

  110523.        && sqlite3StrICmp(&pTab->zName[7],"master")!=0

  110524. #endif

  110525.  ){

  110526.     sqlite3ErrorMsg(pParse, "table %s may not be indexed", pTab->zName);

  110527.     goto exit_create_index;

  110528.   }

  110529. #ifndef SQLITE_OMIT_VIEW

  110530.   if( pTab->pSelect ){

  110531.     sqlite3ErrorMsg(pParse, "views may not be indexed");

  110532.     goto exit_create_index;

  110533.   }

  110534. #endif

  110535. #ifndef SQLITE_OMIT_VIRTUALTABLE

  110536.   if( IsVirtual(pTab) ){

  110537.     sqlite3ErrorMsg(pParse, "virtual tables may not be indexed");

  110538.     goto exit_create_index;

  110539.   }

  110540. #endif

  110541. 

  110542.   /*

  110543.   ** Find the name of the index.  Make sure there is not already another

  110544.   ** index or table with the same name.  

  110545.   **

  110546.   ** Exception:  If we are reading the names of permanent indices from the

  110547.   ** sqlite_master table (because some other process changed the schema) and

  110548.   ** one of the index names collides with the name of a temporary table or

  110549.   ** index, then we will continue to process this index.

  110550.   **

  110551.   ** If pName==0 it means that we are

  110552.   ** dealing with a primary key or UNIQUE constraint.  We have to invent our

  110553.   ** own name.

  110554.   */

  110555.   if( pName ){

  110556.     zName = sqlite3NameFromToken(db, pName);

  110557.     if( zName==0 ) goto exit_create_index;

  110558.     assert( pName->z!=0 );

  110559.     if( SQLITE_OK!=sqlite3CheckObjectName(pParse, zName) ){

  110560.       goto exit_create_index;

  110561.     }

  110562.     if( !IN_RENAME_OBJECT ){

  110563.       if( !db->init.busy ){

  110564.         if( sqlite3FindTable(db, zName, 0)!=0 ){

  110565.           sqlite3ErrorMsg(pParse, "there is already a table named %s", zName);

  110566.           goto exit_create_index;

  110567.         }

  110568.       }

  110569.       if( sqlite3FindIndex(db, zName, pDb->zDbSName)!=0 ){

  110570.         if( !ifNotExist ){

  110571.           sqlite3ErrorMsg(pParse, "index %s already exists", zName);

  110572.         }else{

  110573.           assert( !db->init.busy );

  110574.           sqlite3CodeVerifySchema(pParse, iDb);

  110575.         }

  110576.         goto exit_create_index;

  110577.       }

  110578.     }

  110579.   }else{

  110580.     int n;

  110581.     Index *pLoop;

  110582.     for(pLoop=pTab->pIndex, n=1; pLoop; pLoop=pLoop->pNext, n++){}

  110583.     zName = sqlite3MPrintf(db, "sqlite_autoindex_%s_%d", pTab->zName, n);

  110584.     if( zName==0 ){

  110585.       goto exit_create_index;

  110586.     }

  110587. 

  110588.     /* Automatic index names generated from within sqlite3_declare_vtab()

  110589.     ** must have names that are distinct from normal automatic index names.

  110590.     ** The following statement converts "sqlite3_autoindex..." into

  110591.     ** "sqlite3_butoindex..." in order to make the names distinct.

  110592.     ** The "vtab_err.test" test demonstrates the need of this statement. */

  110593.     if( IN_SPECIAL_PARSE ) zName[7]++;

  110594.   }

  110595. 

  110596.   /* Check for authorization to create an index.

  110597.   */

  110598. #ifndef SQLITE_OMIT_AUTHORIZATION

  110599.   if( !IN_RENAME_OBJECT ){

  110600.     const char *zDb = pDb->zDbSName;

  110601.     if( sqlite3AuthCheck(pParse, SQLITE_INSERT, SCHEMA_TABLE(iDb), 0, zDb) ){

  110602.       goto exit_create_index;

  110603.     }

  110604.     i = SQLITE_CREATE_INDEX;

  110605.     if( !OMIT_TEMPDB && iDb==1 ) i = SQLITE_CREATE_TEMP_INDEX;

  110606.     if( sqlite3AuthCheck(pParse, i, zName, pTab->zName, zDb) ){

  110607.       goto exit_create_index;

  110608.     }

  110609.   }

  110610. #endif

  110611. 

  110612.   /* If pList==0, it means this routine was called to make a primary

  110613.   ** key out of the last column added to the table under construction.

  110614.   ** So create a fake list to simulate this.

  110615.   */

  110616.   if( pList==0 ){

  110617.     Token prevCol;

  110618.     Column *pCol = &pTab->aCol[pTab->nCol-1];

  110619.     pCol->colFlags |= COLFLAG_UNIQUE;

  110620.     sqlite3TokenInit(&prevCol, pCol->zName);

  110621.     pList = sqlite3ExprListAppend(pParse, 0,

  110622.               sqlite3ExprAlloc(db, TK_ID, &prevCol, 0));

  110623.     if( pList==0 ) goto exit_create_index;

  110624.     assert( pList->nExpr==1 );

  110625.     sqlite3ExprListSetSortOrder(pList, sortOrder);

  110626.   }else{

  110627.     sqlite3ExprListCheckLength(pParse, pList, "index");

  110628.     if( pParse->nErr ) goto exit_create_index;

  110629.   }

  110630. 

  110631.   /* Figure out how many bytes of space are required to store explicitly

  110632.   ** specified collation sequence names.

  110633.   */

  110634.   for(i=0; i<pList->nExpr; i++){

  110635.     Expr *pExpr = pList->a[i].pExpr;

  110636.     assert( pExpr!=0 );

  110637.     if( pExpr->op==TK_COLLATE ){

  110638.       nExtra += (1 + sqlite3Strlen30(pExpr->u.zToken));

  110639.     }

  110640.   }

  110641. 

  110642.   /* 

  110643.   ** Allocate the index structure. 

  110644.   */

  110645.   nName = sqlite3Strlen30(zName);

  110646.   nExtraCol = pPk ? pPk->nKeyCol : 1;

  110647.   assert( pList->nExpr + nExtraCol <= 32767 /* Fits in i16 */ );

  110648.   pIndex = sqlite3AllocateIndexObject(db, pList->nExpr + nExtraCol,

  110649.                                       nName + nExtra + 1, &zExtra);

  110650.   if( db->mallocFailed ){

  110651.     goto exit_create_index;

  110652.   }

  110653.   assert( EIGHT_BYTE_ALIGNMENT(pIndex->aiRowLogEst) );

  110654.   assert( EIGHT_BYTE_ALIGNMENT(pIndex->azColl) );

  110655.   pIndex->zName = zExtra;

  110656.   zExtra += nName + 1;

  110657.   memcpy(pIndex->zName, zName, nName+1);

  110658.   pIndex->pTable = pTab;

  110659.   pIndex->onError = (u8)onError;

  110660.   pIndex->uniqNotNull = onError!=OE_None;

  110661.   pIndex->idxType = idxType;

  110662.   pIndex->pSchema = db->aDb[iDb].pSchema;

  110663.   pIndex->nKeyCol = pList->nExpr;

  110664.   if( pPIWhere ){

  110665.     sqlite3ResolveSelfReference(pParse, pTab, NC_PartIdx, pPIWhere, 0);

  110666.     pIndex->pPartIdxWhere = pPIWhere;

  110667.     pPIWhere = 0;

  110668.   }

  110669.   assert( sqlite3SchemaMutexHeld(db, iDb, 0) );

  110670. 

  110671.   /* Check to see if we should honor DESC requests on index columns

  110672.   */

  110673.   if( pDb->pSchema->file_format>=4 ){

  110674.     sortOrderMask = -1;   /* Honor DESC */

  110675.   }else{

  110676.     sortOrderMask = 0;    /* Ignore DESC */

  110677.   }

  110678. 

  110679.   /* Analyze the list of expressions that form the terms of the index and

  110680.   ** report any errors.  In the common case where the expression is exactly

  110681.   ** a table column, store that column in aiColumn[].  For general expressions,

  110682.   ** populate pIndex->aColExpr and store XN_EXPR (-2) in aiColumn[].

  110683.   **

  110684.   ** TODO: Issue a warning if two or more columns of the index are identical.

  110685.   ** TODO: Issue a warning if the table primary key is used as part of the

  110686.   ** index key.

  110687.   */

  110688.   pListItem = pList->a;

  110689.   if( IN_RENAME_OBJECT ){

  110690.     pIndex->aColExpr = pList;

  110691.     pList = 0;

  110692.   }

  110693.   for(i=0; i<pIndex->nKeyCol; i++, pListItem++){

  110694.     Expr *pCExpr;                  /* The i-th index expression */

  110695.     int requestedSortOrder;        /* ASC or DESC on the i-th expression */

  110696.     const char *zColl;             /* Collation sequence name */

  110697. 

  110698.     sqlite3StringToId(pListItem->pExpr);

  110699.     sqlite3ResolveSelfReference(pParse, pTab, NC_IdxExpr, pListItem->pExpr, 0);

  110700.     if( pParse->nErr ) goto exit_create_index;

  110701.     pCExpr = sqlite3ExprSkipCollate(pListItem->pExpr);

  110702.     if( pCExpr->op!=TK_COLUMN ){

  110703.       if( pTab==pParse->pNewTable ){

  110704.         sqlite3ErrorMsg(pParse, "expressions prohibited in PRIMARY KEY and "

  110705.                                 "UNIQUE constraints");

  110706.         goto exit_create_index;

  110707.       }

  110708.       if( pIndex->aColExpr==0 ){

  110709.         pIndex->aColExpr = pList;

  110710.         pList = 0;

  110711.       }

  110712.       j = XN_EXPR;

  110713.       pIndex->aiColumn[i] = XN_EXPR;

  110714.       pIndex->uniqNotNull = 0;

  110715.     }else{

  110716.       j = pCExpr->iColumn;

  110717.       assert( j<=0x7fff );

  110718.       if( j<0 ){

  110719.         j = pTab->iPKey;

  110720.       }else if( pTab->aCol[j].notNull==0 ){

  110721.         pIndex->uniqNotNull = 0;

  110722.       }

  110723.       pIndex->aiColumn[i] = (i16)j;

  110724.     }

  110725.     zColl = 0;

  110726.     if( pListItem->pExpr->op==TK_COLLATE ){

  110727.       int nColl;

  110728.       zColl = pListItem->pExpr->u.zToken;

  110729.       nColl = sqlite3Strlen30(zColl) + 1;

  110730.       assert( nExtra>=nColl );

  110731.       memcpy(zExtra, zColl, nColl);

  110732.       zColl = zExtra;

  110733.       zExtra += nColl;

  110734.       nExtra -= nColl;

  110735.     }else if( j>=0 ){

  110736.       zColl = pTab->aCol[j].zColl;

  110737.     }

  110738.     if( !zColl ) zColl = sqlite3StrBINARY;

  110739.     if( !db->init.busy && !sqlite3LocateCollSeq(pParse, zColl) ){

  110740.       goto exit_create_index;

  110741.     }

  110742.     pIndex->azColl[i] = zColl;

  110743.     requestedSortOrder = pListItem->sortOrder & sortOrderMask;

  110744.     pIndex->aSortOrder[i] = (u8)requestedSortOrder;

  110745.   }

  110746. 

  110747.   /* Append the table key to the end of the index.  For WITHOUT ROWID

  110748.   ** tables (when pPk!=0) this will be the declared PRIMARY KEY.  For

  110749.   ** normal tables (when pPk==0) this will be the rowid.

  110750.   */

  110751.   if( pPk ){

  110752.     for(j=0; j<pPk->nKeyCol; j++){

  110753.       int x = pPk->aiColumn[j];

  110754.       assert( x>=0 );

  110755.       if( isDupColumn(pIndex, pIndex->nKeyCol, pPk, j) ){

  110756.         pIndex->nColumn--; 

  110757.       }else{

  110758.         testcase( hasColumn(pIndex->aiColumn,pIndex->nKeyCol,x) );

  110759.         pIndex->aiColumn[i] = x;

  110760.         pIndex->azColl[i] = pPk->azColl[j];

  110761.         pIndex->aSortOrder[i] = pPk->aSortOrder[j];

  110762.         i++;

  110763.       }

  110764.     }

  110765.     assert( i==pIndex->nColumn );

  110766.   }else{

  110767.     pIndex->aiColumn[i] = XN_ROWID;

  110768.     pIndex->azColl[i] = sqlite3StrBINARY;

  110769.   }

  110770.   sqlite3DefaultRowEst(pIndex);

  110771.   if( pParse->pNewTable==0 ) estimateIndexWidth(pIndex);

  110772. 

  110773.   /* If this index contains every column of its table, then mark

  110774.   ** it as a covering index */

  110775.   assert( HasRowid(pTab) 

  110776.       || pTab->iPKey<0 || sqlite3ColumnOfIndex(pIndex, pTab->iPKey)>=0 );

  110777.   recomputeColumnsNotIndexed(pIndex);

  110778.   if( pTblName!=0 && pIndex->nColumn>=pTab->nCol ){

  110779.     pIndex->isCovering = 1;

  110780.     for(j=0; j<pTab->nCol; j++){

  110781.       if( j==pTab->iPKey ) continue;

  110782.       if( sqlite3ColumnOfIndex(pIndex,j)>=0 ) continue;

  110783.       pIndex->isCovering = 0;

  110784.       break;

  110785.     }

  110786.   }

  110787. 

  110788.   if( pTab==pParse->pNewTable ){

  110789.     /* This routine has been called to create an automatic index as a

  110790.     ** result of a PRIMARY KEY or UNIQUE clause on a column definition, or

  110791.     ** a PRIMARY KEY or UNIQUE clause following the column definitions.

  110792.     ** i.e. one of:

  110793.     **

  110794.     ** CREATE TABLE t(x PRIMARY KEY, y);

  110795.     ** CREATE TABLE t(x, y, UNIQUE(x, y));

  110796.     **

  110797.     ** Either way, check to see if the table already has such an index. If

  110798.     ** so, don't bother creating this one. This only applies to

  110799.     ** automatically created indices. Users can do as they wish with

  110800.     ** explicit indices.

  110801.     **

  110802.     ** Two UNIQUE or PRIMARY KEY constraints are considered equivalent

  110803.     ** (and thus suppressing the second one) even if they have different

  110804.     ** sort orders.

  110805.     **

  110806.     ** If there are different collating sequences or if the columns of

  110807.     ** the constraint occur in different orders, then the constraints are

  110808.     ** considered distinct and both result in separate indices.

  110809.     */

  110810.     Index *pIdx;

  110811.     for(pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext){

  110812.       int k;

  110813.       assert( IsUniqueIndex(pIdx) );

  110814.       assert( pIdx->idxType!=SQLITE_IDXTYPE_APPDEF );

  110815.       assert( IsUniqueIndex(pIndex) );

  110816. 

  110817.       if( pIdx->nKeyCol!=pIndex->nKeyCol ) continue;

  110818.       for(k=0; k<pIdx->nKeyCol; k++){

  110819.         const char *z1;

  110820.         const char *z2;

  110821.         assert( pIdx->aiColumn[k]>=0 );

  110822.         if( pIdx->aiColumn[k]!=pIndex->aiColumn[k] ) break;

  110823.         z1 = pIdx->azColl[k];

  110824.         z2 = pIndex->azColl[k];

  110825.         if( sqlite3StrICmp(z1, z2) ) break;

  110826.       }

  110827.       if( k==pIdx->nKeyCol ){

  110828.         if( pIdx->onError!=pIndex->onError ){

  110829.           /* This constraint creates the same index as a previous

  110830.           ** constraint specified somewhere in the CREATE TABLE statement.

  110831.           ** However the ON CONFLICT clauses are different. If both this 

  110832.           ** constraint and the previous equivalent constraint have explicit

  110833.           ** ON CONFLICT clauses this is an error. Otherwise, use the

  110834.           ** explicitly specified behavior for the index.

  110835.           */

  110836.           if( !(pIdx->onError==OE_Default || pIndex->onError==OE_Default) ){

  110837.             sqlite3ErrorMsg(pParse, 

  110838.                 "conflicting ON CONFLICT clauses specified", 0);

  110839.           }

  110840.           if( pIdx->onError==OE_Default ){

  110841.             pIdx->onError = pIndex->onError;

  110842.           }

  110843.         }

  110844.         if( idxType==SQLITE_IDXTYPE_PRIMARYKEY ) pIdx->idxType = idxType;

  110845.         if( IN_RENAME_OBJECT ){

  110846.           pIndex->pNext = pParse->pNewIndex;

  110847.           pParse->pNewIndex = pIndex;

  110848.           pIndex = 0;

  110849.         }

  110850.         goto exit_create_index;

  110851.       }

  110852.     }

  110853.   }

  110854. 

  110855.   if( !IN_RENAME_OBJECT ){

  110856. 

  110857.     /* Link the new Index structure to its table and to the other

  110858.     ** in-memory database structures. 

  110859.     */

  110860.     assert( pParse->nErr==0 );

  110861.     if( db->init.busy ){

  110862.       Index *p;

  110863.       assert( !IN_SPECIAL_PARSE );

  110864.       assert( sqlite3SchemaMutexHeld(db, 0, pIndex->pSchema) );

  110865.       if( pTblName!=0 ){

  110866.         pIndex->tnum = db->init.newTnum;

  110867.         if( sqlite3IndexHasDuplicateRootPage(pIndex) ){

  110868.           sqlite3ErrorMsg(pParse, "invalid rootpage");

  110869.           pParse->rc = SQLITE_CORRUPT_BKPT;

  110870.           goto exit_create_index;

  110871.         }

  110872.       }

  110873.       p = sqlite3HashInsert(&pIndex->pSchema->idxHash, 

  110874.           pIndex->zName, pIndex);

  110875.       if( p ){

  110876.         assert( p==pIndex );  /* Malloc must have failed */

  110877.         sqlite3OomFault(db);

  110878.         goto exit_create_index;

  110879.       }

  110880.       db->mDbFlags |= DBFLAG_SchemaChange;

  110881.     }

  110882. 

  110883.     /* If this is the initial CREATE INDEX statement (or CREATE TABLE if the

  110884.     ** index is an implied index for a UNIQUE or PRIMARY KEY constraint) then

  110885.     ** emit code to allocate the index rootpage on disk and make an entry for

  110886.     ** the index in the sqlite_master table and populate the index with

  110887.     ** content.  But, do not do this if we are simply reading the sqlite_master

  110888.     ** table to parse the schema, or if this index is the PRIMARY KEY index

  110889.     ** of a WITHOUT ROWID table.

  110890.     **

  110891.     ** If pTblName==0 it means this index is generated as an implied PRIMARY KEY

  110892.     ** or UNIQUE index in a CREATE TABLE statement.  Since the table

  110893.     ** has just been created, it contains no data and the index initialization

  110894.     ** step can be skipped.

  110895.     */

  110896.     else if( HasRowid(pTab) || pTblName!=0 ){

  110897.       Vdbe *v;

  110898.       char *zStmt;

  110899.       int iMem = ++pParse->nMem;

  110900. 

  110901.       v = sqlite3GetVdbe(pParse);

  110902.       if( v==0 ) goto exit_create_index;

  110903. 

  110904.       sqlite3BeginWriteOperation(pParse, 1, iDb);

  110905. 

  110906.       /* Create the rootpage for the index using CreateIndex. But before

  110907.       ** doing so, code a Noop instruction and store its address in 

  110908.       ** Index.tnum. This is required in case this index is actually a 

  110909.       ** PRIMARY KEY and the table is actually a WITHOUT ROWID table. In 

  110910.       ** that case the convertToWithoutRowidTable() routine will replace

  110911.       ** the Noop with a Goto to jump over the VDBE code generated below. */

  110912.       pIndex->tnum = sqlite3VdbeAddOp0(v, OP_Noop);

  110913.       sqlite3VdbeAddOp3(v, OP_CreateBtree, iDb, iMem, BTREE_BLOBKEY);

  110914. 

  110915.       /* Gather the complete text of the CREATE INDEX statement into

  110916.       ** the zStmt variable

  110917.       */

  110918.       if( pStart ){

  110919.         int n = (int)(pParse->sLastToken.z - pName->z) + pParse->sLastToken.n;

  110920.         if( pName->z[n-1]==';' ) n--;

  110921.         /* A named index with an explicit CREATE INDEX statement */

  110922.         zStmt = sqlite3MPrintf(db, "CREATE%s INDEX %.*s",

  110923.             onError==OE_None ? "" : " UNIQUE", n, pName->z);

  110924.       }else{

  110925.         /* An automatic index created by a PRIMARY KEY or UNIQUE constraint */

  110926.         /* zStmt = sqlite3MPrintf(""); */

  110927.         zStmt = 0;

  110928.       }

  110929. 

  110930.       /* Add an entry in sqlite_master for this index

  110931.       */

  110932.       sqlite3NestedParse(pParse, 

  110933.           "INSERT INTO %Q.%s VALUES('index',%Q,%Q,#%d,%Q);",

  110934.           db->aDb[iDb].zDbSName, MASTER_NAME,

  110935.           pIndex->zName,

  110936.           pTab->zName,

  110937.           iMem,

  110938.           zStmt

  110939.           );

  110940.       sqlite3DbFree(db, zStmt);

  110941. 

  110942.       /* Fill the index with data and reparse the schema. Code an OP_Expire

  110943.       ** to invalidate all pre-compiled statements.

  110944.       */

  110945.       if( pTblName ){

  110946.         sqlite3RefillIndex(pParse, pIndex, iMem);

  110947.         sqlite3ChangeCookie(pParse, iDb);

  110948.         sqlite3VdbeAddParseSchemaOp(v, iDb,

  110949.             sqlite3MPrintf(db, "name='%q' AND type='index'", pIndex->zName));

  110950.         sqlite3VdbeAddOp2(v, OP_Expire, 0, 1);

  110951.       }

  110952. 

  110953.       sqlite3VdbeJumpHere(v, pIndex->tnum);

  110954.     }

  110955.   }

  110956. 

  110957.   /* When adding an index to the list of indices for a table, make

  110958.   ** sure all indices labeled OE_Replace come after all those labeled

  110959.   ** OE_Ignore.  This is necessary for the correct constraint check

  110960.   ** processing (in sqlite3GenerateConstraintChecks()) as part of

  110961.   ** UPDATE and INSERT statements.  

  110962.   */

  110963.   if( db->init.busy || pTblName==0 ){

  110964.     if( onError!=OE_Replace || pTab->pIndex==0

  110965.          || pTab->pIndex->onError==OE_Replace){

  110966.       pIndex->pNext = pTab->pIndex;

  110967.       pTab->pIndex = pIndex;

  110968.     }else{

  110969.       Index *pOther = pTab->pIndex;

  110970.       while( pOther->pNext && pOther->pNext->onError!=OE_Replace ){

  110971.         pOther = pOther->pNext;

  110972.       }

  110973.       pIndex->pNext = pOther->pNext;

  110974.       pOther->pNext = pIndex;

  110975.     }

  110976.     pIndex = 0;

  110977.   }

  110978.   else if( IN_RENAME_OBJECT ){

  110979.     assert( pParse->pNewIndex==0 );

  110980.     pParse->pNewIndex = pIndex;

  110981.     pIndex = 0;

  110982.   }

  110983. 

  110984.   /* Clean up before exiting */

  110985. exit_create_index:

  110986.   if( pIndex ) sqlite3FreeIndex(db, pIndex);

  110987.   sqlite3ExprDelete(db, pPIWhere);

  110988.   sqlite3ExprListDelete(db, pList);

  110989.   sqlite3SrcListDelete(db, pTblName);

  110990.   sqlite3DbFree(db, zName);

  110991. }

  110992. 

  110993. /*

  110994. ** Fill the Index.aiRowEst[] array with default information - information

  110995. ** to be used when we have not run the ANALYZE command.

  110996. **

  110997. ** aiRowEst[0] is supposed to contain the number of elements in the index.

  110998. ** Since we do not know, guess 1 million.  aiRowEst[1] is an estimate of the

  110999. ** number of rows in the table that match any particular value of the

  111000. ** first column of the index.  aiRowEst[2] is an estimate of the number

  111001. ** of rows that match any particular combination of the first 2 columns

  111002. ** of the index.  And so forth.  It must always be the case that

  111003. *

  111004. **           aiRowEst[N]<=aiRowEst[N-1]

  111005. **           aiRowEst[N]>=1

  111006. **

  111007. ** Apart from that, we have little to go on besides intuition as to

  111008. ** how aiRowEst[] should be initialized.  The numbers generated here

  111009. ** are based on typical values found in actual indices.

  111010. */

  111011. SQLITE_PRIVATE void sqlite3DefaultRowEst(Index *pIdx){

  111012.   /*                10,  9,  8,  7,  6 */

  111013.   LogEst aVal[] = { 33, 32, 30, 28, 26 };

  111014.   LogEst *a = pIdx->aiRowLogEst;

  111015.   int nCopy = MIN(ArraySize(aVal), pIdx->nKeyCol);

  111016.   int i;

  111017. 

  111018.   /* Indexes with default row estimates should not have stat1 data */

  111019.   assert( !pIdx->hasStat1 );

  111020. 

  111021.   /* Set the first entry (number of rows in the index) to the estimated 

  111022.   ** number of rows in the table, or half the number of rows in the table

  111023.   ** for a partial index.   But do not let the estimate drop below 10. */

  111024.   a[0] = pIdx->pTable->nRowLogEst;

  111025.   if( pIdx->pPartIdxWhere!=0 ) a[0] -= 10;  assert( 10==sqlite3LogEst(2) );

  111026.   if( a[0]<33 ) a[0] = 33;                  assert( 33==sqlite3LogEst(10) );

  111027. 

  111028.   /* Estimate that a[1] is 10, a[2] is 9, a[3] is 8, a[4] is 7, a[5] is

  111029.   ** 6 and each subsequent value (if any) is 5.  */

  111030.   memcpy(&a[1], aVal, nCopy*sizeof(LogEst));

  111031.   for(i=nCopy+1; i<=pIdx->nKeyCol; i++){

  111032.     a[i] = 23;                    assert( 23==sqlite3LogEst(5) );

  111033.   }

  111034. 

  111035.   assert( 0==sqlite3LogEst(1) );

  111036.   if( IsUniqueIndex(pIdx) ) a[pIdx->nKeyCol] = 0;

  111037. }

  111038. 

  111039. /*

  111040. ** This routine will drop an existing named index.  This routine

  111041. ** implements the DROP INDEX statement.

  111042. */

  111043. SQLITE_PRIVATE void sqlite3DropIndex(Parse *pParse, SrcList *pName, int ifExists){

  111044.   Index *pIndex;

  111045.   Vdbe *v;

  111046.   sqlite3 *db = pParse->db;

  111047.   int iDb;

  111048. 

  111049.   assert( pParse->nErr==0 );   /* Never called with prior errors */

  111050.   if( db->mallocFailed ){

  111051.     goto exit_drop_index;

  111052.   }

  111053.   assert( pName->nSrc==1 );

  111054.   if( SQLITE_OK!=sqlite3ReadSchema(pParse) ){

  111055.     goto exit_drop_index;

  111056.   }

  111057.   pIndex = sqlite3FindIndex(db, pName->a[0].zName, pName->a[0].zDatabase);

  111058.   if( pIndex==0 ){

  111059.     if( !ifExists ){

  111060.       sqlite3ErrorMsg(pParse, "no such index: %S", pName, 0);

  111061.     }else{

  111062.       sqlite3CodeVerifyNamedSchema(pParse, pName->a[0].zDatabase);

  111063.     }

  111064.     pParse->checkSchema = 1;

  111065.     goto exit_drop_index;

  111066.   }

  111067.   if( pIndex->idxType!=SQLITE_IDXTYPE_APPDEF ){

  111068.     sqlite3ErrorMsg(pParse, "index associated with UNIQUE "

  111069.       "or PRIMARY KEY constraint cannot be dropped", 0);

  111070.     goto exit_drop_index;

  111071.   }

  111072.   iDb = sqlite3SchemaToIndex(db, pIndex->pSchema);

  111073. #ifndef SQLITE_OMIT_AUTHORIZATION

  111074.   {

  111075.     int code = SQLITE_DROP_INDEX;

  111076.     Table *pTab = pIndex->pTable;

  111077.     const char *zDb = db->aDb[iDb].zDbSName;

  111078.     const char *zTab = SCHEMA_TABLE(iDb);

  111079.     if( sqlite3AuthCheck(pParse, SQLITE_DELETE, zTab, 0, zDb) ){

  111080.       goto exit_drop_index;

  111081.     }

  111082.     if( !OMIT_TEMPDB && iDb ) code = SQLITE_DROP_TEMP_INDEX;

  111083.     if( sqlite3AuthCheck(pParse, code, pIndex->zName, pTab->zName, zDb) ){

  111084.       goto exit_drop_index;

  111085.     }

  111086.   }

  111087. #endif

  111088. 

  111089.   /* Generate code to remove the index and from the master table */

  111090.   v = sqlite3GetVdbe(pParse);

  111091.   if( v ){

  111092.     sqlite3BeginWriteOperation(pParse, 1, iDb);

  111093.     sqlite3NestedParse(pParse,

  111094.        "DELETE FROM %Q.%s WHERE name=%Q AND type='index'",

  111095.        db->aDb[iDb].zDbSName, MASTER_NAME, pIndex->zName

  111096.     );

  111097.     sqlite3ClearStatTables(pParse, iDb, "idx", pIndex->zName);

  111098.     sqlite3ChangeCookie(pParse, iDb);

  111099.     destroyRootPage(pParse, pIndex->tnum, iDb);

  111100.     sqlite3VdbeAddOp4(v, OP_DropIndex, iDb, 0, 0, pIndex->zName, 0);

  111101.   }

  111102. 

  111103. exit_drop_index:

  111104.   sqlite3SrcListDelete(db, pName);

  111105. }

  111106. 

  111107. /*

  111108. ** pArray is a pointer to an array of objects. Each object in the

  111109. ** array is szEntry bytes in size. This routine uses sqlite3DbRealloc()

  111110. ** to extend the array so that there is space for a new object at the end.

  111111. **

  111112. ** When this function is called, *pnEntry contains the current size of

  111113. ** the array (in entries - so the allocation is ((*pnEntry) * szEntry) bytes

  111114. ** in total).

  111115. **

  111116. ** If the realloc() is successful (i.e. if no OOM condition occurs), the

  111117. ** space allocated for the new object is zeroed, *pnEntry updated to

  111118. ** reflect the new size of the array and a pointer to the new allocation

  111119. ** returned. *pIdx is set to the index of the new array entry in this case.

  111120. **

  111121. ** Otherwise, if the realloc() fails, *pIdx is set to -1, *pnEntry remains

  111122. ** unchanged and a copy of pArray returned.

  111123. */

  111124. SQLITE_PRIVATE void *sqlite3ArrayAllocate(

  111125.   sqlite3 *db,      /* Connection to notify of malloc failures */

  111126.   void *pArray,     /* Array of objects.  Might be reallocated */

  111127.   int szEntry,      /* Size of each object in the array */

  111128.   int *pnEntry,     /* Number of objects currently in use */

  111129.   int *pIdx         /* Write the index of a new slot here */

  111130. ){

  111131.   char *z;

  111132.   sqlite3_int64 n = *pIdx = *pnEntry;

  111133.   if( (n & (n-1))==0 ){

  111134.     sqlite3_int64 sz = (n==0) ? 1 : 2*n;

  111135.     void *pNew = sqlite3DbRealloc(db, pArray, sz*szEntry);

  111136.     if( pNew==0 ){

  111137.       *pIdx = -1;

  111138.       return pArray;

  111139.     }

  111140.     pArray = pNew;

  111141.   }

  111142.   z = (char*)pArray;

  111143.   memset(&z[n * szEntry], 0, szEntry);

  111144.   ++*pnEntry;

  111145.   return pArray;

  111146. }

  111147. 

  111148. /*

  111149. ** Append a new element to the given IdList.  Create a new IdList if

  111150. ** need be.

  111151. **

  111152. ** A new IdList is returned, or NULL if malloc() fails.

  111153. */

  111154. SQLITE_PRIVATE IdList *sqlite3IdListAppend(Parse *pParse, IdList *pList, Token *pToken){

  111155.   sqlite3 *db = pParse->db;

  111156.   int i;

  111157.   if( pList==0 ){

  111158.     pList = sqlite3DbMallocZero(db, sizeof(IdList) );

  111159.     if( pList==0 ) return 0;

  111160.   }

  111161.   pList->a = sqlite3ArrayAllocate(

  111162.       db,

  111163.       pList->a,

  111164.       sizeof(pList->a[0]),

  111165.       &pList->nId,

  111166.       &i

  111167.   );

  111168.   if( i<0 ){

  111169.     sqlite3IdListDelete(db, pList);

  111170.     return 0;

  111171.   }

  111172.   pList->a[i].zName = sqlite3NameFromToken(db, pToken);

  111173.   if( IN_RENAME_OBJECT && pList->a[i].zName ){

  111174.     sqlite3RenameTokenMap(pParse, (void*)pList->a[i].zName, pToken);

  111175.   }

  111176.   return pList;

  111177. }

  111178. 

  111179. /*

  111180. ** Delete an IdList.

  111181. */

  111182. SQLITE_PRIVATE void sqlite3IdListDelete(sqlite3 *db, IdList *pList){

  111183.   int i;

  111184.   if( pList==0 ) return;

  111185.   for(i=0; i<pList->nId; i++){

  111186.     sqlite3DbFree(db, pList->a[i].zName);

  111187.   }

  111188.   sqlite3DbFree(db, pList->a);

  111189.   sqlite3DbFreeNN(db, pList);

  111190. }

  111191. 

  111192. /*

  111193. ** Return the index in pList of the identifier named zId.  Return -1

  111194. ** if not found.

  111195. */

  111196. SQLITE_PRIVATE int sqlite3IdListIndex(IdList *pList, const char *zName){

  111197.   int i;

  111198.   if( pList==0 ) return -1;

  111199.   for(i=0; i<pList->nId; i++){

  111200.     if( sqlite3StrICmp(pList->a[i].zName, zName)==0 ) return i;

  111201.   }

  111202.   return -1;

  111203. }

  111204. 

  111205. /*

  111206. ** Maximum size of a SrcList object.

  111207. ** The SrcList object is used to represent the FROM clause of a

  111208. ** SELECT statement, and the query planner cannot deal with more

  111209. ** than 64 tables in a join.  So any value larger than 64 here

  111210. ** is sufficient for most uses.  Smaller values, like say 10, are

  111211. ** appropriate for small and memory-limited applications.

  111212. */

  111213. #ifndef SQLITE_MAX_SRCLIST

  111214. # define SQLITE_MAX_SRCLIST 200

  111215. #endif

  111216. 

  111217. /*

  111218. ** Expand the space allocated for the given SrcList object by

  111219. ** creating nExtra new slots beginning at iStart.  iStart is zero based.

  111220. ** New slots are zeroed.

  111221. **

  111222. ** For example, suppose a SrcList initially contains two entries: A,B.

  111223. ** To append 3 new entries onto the end, do this:

  111224. **

  111225. **    sqlite3SrcListEnlarge(db, pSrclist, 3, 2);

  111226. **

  111227. ** After the call above it would contain:  A, B, nil, nil, nil.

  111228. ** If the iStart argument had been 1 instead of 2, then the result

  111229. ** would have been:  A, nil, nil, nil, B.  To prepend the new slots,

  111230. ** the iStart value would be 0.  The result then would

  111231. ** be: nil, nil, nil, A, B.

  111232. **

  111233. ** If a memory allocation fails or the SrcList becomes too large, leave

  111234. ** the original SrcList unchanged, return NULL, and leave an error message

  111235. ** in pParse.

  111236. */

  111237. SQLITE_PRIVATE SrcList *sqlite3SrcListEnlarge(

  111238.   Parse *pParse,     /* Parsing context into which errors are reported */

  111239.   SrcList *pSrc,     /* The SrcList to be enlarged */

  111240.   int nExtra,        /* Number of new slots to add to pSrc->a[] */

  111241.   int iStart         /* Index in pSrc->a[] of first new slot */

  111242. ){

  111243.   int i;

  111244. 

  111245.   /* Sanity checking on calling parameters */

  111246.   assert( iStart>=0 );

  111247.   assert( nExtra>=1 );

  111248.   assert( pSrc!=0 );

  111249.   assert( iStart<=pSrc->nSrc );

  111250. 

  111251.   /* Allocate additional space if needed */

  111252.   if( (u32)pSrc->nSrc+nExtra>pSrc->nAlloc ){

  111253.     SrcList *pNew;

  111254.     sqlite3_int64 nAlloc = 2*(sqlite3_int64)pSrc->nSrc+nExtra;

  111255.     sqlite3 *db = pParse->db;

  111256. 

  111257.     if( pSrc->nSrc+nExtra>=SQLITE_MAX_SRCLIST ){

  111258.       sqlite3ErrorMsg(pParse, "too many FROM clause terms, max: %d",

  111259.                       SQLITE_MAX_SRCLIST);

  111260.       return 0;

  111261.     }

  111262.     if( nAlloc>SQLITE_MAX_SRCLIST ) nAlloc = SQLITE_MAX_SRCLIST;

  111263.     pNew = sqlite3DbRealloc(db, pSrc,

  111264.                sizeof(*pSrc) + (nAlloc-1)*sizeof(pSrc->a[0]) );

  111265.     if( pNew==0 ){

  111266.       assert( db->mallocFailed );

  111267.       return 0;

  111268.     }

  111269.     pSrc = pNew;

  111270.     pSrc->nAlloc = nAlloc;

  111271.   }

  111272. 

  111273.   /* Move existing slots that come after the newly inserted slots

  111274.   ** out of the way */

  111275.   for(i=pSrc->nSrc-1; i>=iStart; i--){

  111276.     pSrc->a[i+nExtra] = pSrc->a[i];

  111277.   }

  111278.   pSrc->nSrc += nExtra;

  111279. 

  111280.   /* Zero the newly allocated slots */

  111281.   memset(&pSrc->a[iStart], 0, sizeof(pSrc->a[0])*nExtra);

  111282.   for(i=iStart; i<iStart+nExtra; i++){

  111283.     pSrc->a[i].iCursor = -1;

  111284.   }

  111285. 

  111286.   /* Return a pointer to the enlarged SrcList */

  111287.   return pSrc;

  111288. }

  111289. 

  111290. 

  111291. /*

  111292. ** Append a new table name to the given SrcList.  Create a new SrcList if

  111293. ** need be.  A new entry is created in the SrcList even if pTable is NULL.

  111294. **

  111295. ** A SrcList is returned, or NULL if there is an OOM error or if the

  111296. ** SrcList grows to large.  The returned

  111297. ** SrcList might be the same as the SrcList that was input or it might be

  111298. ** a new one.  If an OOM error does occurs, then the prior value of pList

  111299. ** that is input to this routine is automatically freed.

  111300. **

  111301. ** If pDatabase is not null, it means that the table has an optional

  111302. ** database name prefix.  Like this:  "database.table".  The pDatabase

  111303. ** points to the table name and the pTable points to the database name.

  111304. ** The SrcList.a[].zName field is filled with the table name which might

  111305. ** come from pTable (if pDatabase is NULL) or from pDatabase.  

  111306. ** SrcList.a[].zDatabase is filled with the database name from pTable,

  111307. ** or with NULL if no database is specified.

  111308. **

  111309. ** In other words, if call like this:

  111310. **

  111311. **         sqlite3SrcListAppend(D,A,B,0);

  111312. **

  111313. ** Then B is a table name and the database name is unspecified.  If called

  111314. ** like this:

  111315. **

  111316. **         sqlite3SrcListAppend(D,A,B,C);

  111317. **

  111318. ** Then C is the table name and B is the database name.  If C is defined

  111319. ** then so is B.  In other words, we never have a case where:

  111320. **

  111321. **         sqlite3SrcListAppend(D,A,0,C);

  111322. **

  111323. ** Both pTable and pDatabase are assumed to be quoted.  They are dequoted

  111324. ** before being added to the SrcList.

  111325. */

  111326. SQLITE_PRIVATE SrcList *sqlite3SrcListAppend(

  111327.   Parse *pParse,      /* Parsing context, in which errors are reported */

  111328.   SrcList *pList,     /* Append to this SrcList. NULL creates a new SrcList */

  111329.   Token *pTable,      /* Table to append */

  111330.   Token *pDatabase    /* Database of the table */

  111331. ){

  111332.   struct SrcList_item *pItem;

  111333.   sqlite3 *db;

  111334.   assert( pDatabase==0 || pTable!=0 );  /* Cannot have C without B */

  111335.   assert( pParse!=0 );

  111336.   assert( pParse->db!=0 );

  111337.   db = pParse->db;

  111338.   if( pList==0 ){

  111339.     pList = sqlite3DbMallocRawNN(pParse->db, sizeof(SrcList) );

  111340.     if( pList==0 ) return 0;

  111341.     pList->nAlloc = 1;

  111342.     pList->nSrc = 1;

  111343.     memset(&pList->a[0], 0, sizeof(pList->a[0]));

  111344.     pList->a[0].iCursor = -1;

  111345.   }else{

  111346.     SrcList *pNew = sqlite3SrcListEnlarge(pParse, pList, 1, pList->nSrc);

  111347.     if( pNew==0 ){

  111348.       sqlite3SrcListDelete(db, pList);

  111349.       return 0;

  111350.     }else{

  111351.       pList = pNew;

  111352.     }

  111353.   }

  111354.   pItem = &pList->a[pList->nSrc-1];

  111355.   if( pDatabase && pDatabase->z==0 ){

  111356.     pDatabase = 0;

  111357.   }

  111358.   if( pDatabase ){

  111359.     pItem->zName = sqlite3NameFromToken(db, pDatabase);

  111360.     pItem->zDatabase = sqlite3NameFromToken(db, pTable);

  111361.   }else{

  111362.     pItem->zName = sqlite3NameFromToken(db, pTable);

  111363.     pItem->zDatabase = 0;

  111364.   }

  111365.   return pList;

  111366. }

  111367. 

  111368. /*

  111369. ** Assign VdbeCursor index numbers to all tables in a SrcList

  111370. */

  111371. SQLITE_PRIVATE void sqlite3SrcListAssignCursors(Parse *pParse, SrcList *pList){

  111372.   int i;

  111373.   struct SrcList_item *pItem;

  111374.   assert(pList || pParse->db->mallocFailed );

  111375.   if( pList ){

  111376.     for(i=0, pItem=pList->a; i<pList->nSrc; i++, pItem++){

  111377.       if( pItem->iCursor>=0 ) break;

  111378.       pItem->iCursor = pParse->nTab++;

  111379.       if( pItem->pSelect ){

  111380.         sqlite3SrcListAssignCursors(pParse, pItem->pSelect->pSrc);

  111381.       }

  111382.     }

  111383.   }

  111384. }

  111385. 

  111386. /*

  111387. ** Delete an entire SrcList including all its substructure.

  111388. */

  111389. SQLITE_PRIVATE void sqlite3SrcListDelete(sqlite3 *db, SrcList *pList){

  111390.   int i;

  111391.   struct SrcList_item *pItem;

  111392.   if( pList==0 ) return;

  111393.   for(pItem=pList->a, i=0; i<pList->nSrc; i++, pItem++){

  111394.     sqlite3DbFree(db, pItem->zDatabase);

  111395.     sqlite3DbFree(db, pItem->zName);

  111396.     sqlite3DbFree(db, pItem->zAlias);

  111397.     if( pItem->fg.isIndexedBy ) sqlite3DbFree(db, pItem->u1.zIndexedBy);

  111398.     if( pItem->fg.isTabFunc ) sqlite3ExprListDelete(db, pItem->u1.pFuncArg);

  111399.     sqlite3DeleteTable(db, pItem->pTab);

  111400.     sqlite3SelectDelete(db, pItem->pSelect);

  111401.     sqlite3ExprDelete(db, pItem->pOn);

  111402.     sqlite3IdListDelete(db, pItem->pUsing);

  111403.   }

  111404.   sqlite3DbFreeNN(db, pList);

  111405. }

  111406. 

  111407. /*

  111408. ** This routine is called by the parser to add a new term to the

  111409. ** end of a growing FROM clause.  The "p" parameter is the part of

  111410. ** the FROM clause that has already been constructed.  "p" is NULL

  111411. ** if this is the first term of the FROM clause.  pTable and pDatabase

  111412. ** are the name of the table and database named in the FROM clause term.

  111413. ** pDatabase is NULL if the database name qualifier is missing - the

  111414. ** usual case.  If the term has an alias, then pAlias points to the

  111415. ** alias token.  If the term is a subquery, then pSubquery is the

  111416. ** SELECT statement that the subquery encodes.  The pTable and

  111417. ** pDatabase parameters are NULL for subqueries.  The pOn and pUsing

  111418. ** parameters are the content of the ON and USING clauses.

  111419. **

  111420. ** Return a new SrcList which encodes is the FROM with the new

  111421. ** term added.

  111422. */

  111423. SQLITE_PRIVATE SrcList *sqlite3SrcListAppendFromTerm(

  111424.   Parse *pParse,          /* Parsing context */

  111425.   SrcList *p,             /* The left part of the FROM clause already seen */

  111426.   Token *pTable,          /* Name of the table to add to the FROM clause */

  111427.   Token *pDatabase,       /* Name of the database containing pTable */

  111428.   Token *pAlias,          /* The right-hand side of the AS subexpression */

  111429.   Select *pSubquery,      /* A subquery used in place of a table name */

  111430.   Expr *pOn,              /* The ON clause of a join */

  111431.   IdList *pUsing          /* The USING clause of a join */

  111432. ){

  111433.   struct SrcList_item *pItem;

  111434.   sqlite3 *db = pParse->db;

  111435.   if( !p && (pOn || pUsing) ){

  111436.     sqlite3ErrorMsg(pParse, "a JOIN clause is required before %s", 

  111437.       (pOn ? "ON" : "USING")

  111438.     );

  111439.     goto append_from_error;

  111440.   }

  111441.   p = sqlite3SrcListAppend(pParse, p, pTable, pDatabase);

  111442.   if( p==0 ){

  111443.     goto append_from_error;

  111444.   }

  111445.   assert( p->nSrc>0 );

  111446.   pItem = &p->a[p->nSrc-1];

  111447.   assert( (pTable==0)==(pDatabase==0) );

  111448.   assert( pItem->zName==0 || pDatabase!=0 );

  111449.   if( IN_RENAME_OBJECT && pItem->zName ){

  111450.     Token *pToken = (ALWAYS(pDatabase) && pDatabase->z) ? pDatabase : pTable;

  111451.     sqlite3RenameTokenMap(pParse, pItem->zName, pToken);

  111452.   }

  111453.   assert( pAlias!=0 );

  111454.   if( pAlias->n ){

  111455.     pItem->zAlias = sqlite3NameFromToken(db, pAlias);

  111456.   }

  111457.   pItem->pSelect = pSubquery;

  111458.   pItem->pOn = pOn;

  111459.   pItem->pUsing = pUsing;

  111460.   return p;

  111461. 

  111462.  append_from_error:

  111463.   assert( p==0 );

  111464.   sqlite3ExprDelete(db, pOn);

  111465.   sqlite3IdListDelete(db, pUsing);

  111466.   sqlite3SelectDelete(db, pSubquery);

  111467.   return 0;

  111468. }

  111469. 

  111470. /*

  111471. ** Add an INDEXED BY or NOT INDEXED clause to the most recently added 

  111472. ** element of the source-list passed as the second argument.

  111473. */

  111474. SQLITE_PRIVATE void sqlite3SrcListIndexedBy(Parse *pParse, SrcList *p, Token *pIndexedBy){

  111475.   assert( pIndexedBy!=0 );

  111476.   if( p && pIndexedBy->n>0 ){

  111477.     struct SrcList_item *pItem;

  111478.     assert( p->nSrc>0 );

  111479.     pItem = &p->a[p->nSrc-1];

  111480.     assert( pItem->fg.notIndexed==0 );

  111481.     assert( pItem->fg.isIndexedBy==0 );

  111482.     assert( pItem->fg.isTabFunc==0 );

  111483.     if( pIndexedBy->n==1 && !pIndexedBy->z ){

  111484.       /* A "NOT INDEXED" clause was supplied. See parse.y 

  111485.       ** construct "indexed_opt" for details. */

  111486.       pItem->fg.notIndexed = 1;

  111487.     }else{

  111488.       pItem->u1.zIndexedBy = sqlite3NameFromToken(pParse->db, pIndexedBy);

  111489.       pItem->fg.isIndexedBy = 1;

  111490.     }

  111491.   }

  111492. }

  111493. 

  111494. /*

  111495. ** Add the list of function arguments to the SrcList entry for a

  111496. ** table-valued-function.

  111497. */

  111498. SQLITE_PRIVATE void sqlite3SrcListFuncArgs(Parse *pParse, SrcList *p, ExprList *pList){

  111499.   if( p ){

  111500.     struct SrcList_item *pItem = &p->a[p->nSrc-1];

  111501.     assert( pItem->fg.notIndexed==0 );

  111502.     assert( pItem->fg.isIndexedBy==0 );

  111503.     assert( pItem->fg.isTabFunc==0 );

  111504.     pItem->u1.pFuncArg = pList;

  111505.     pItem->fg.isTabFunc = 1;

  111506.   }else{

  111507.     sqlite3ExprListDelete(pParse->db, pList);

  111508.   }

  111509. }

  111510. 

  111511. /*

  111512. ** When building up a FROM clause in the parser, the join operator

  111513. ** is initially attached to the left operand.  But the code generator

  111514. ** expects the join operator to be on the right operand.  This routine

  111515. ** Shifts all join operators from left to right for an entire FROM

  111516. ** clause.

  111517. **

  111518. ** Example: Suppose the join is like this:

  111519. **

  111520. **           A natural cross join B

  111521. **

  111522. ** The operator is "natural cross join".  The A and B operands are stored

  111523. ** in p->a[0] and p->a[1], respectively.  The parser initially stores the

  111524. ** operator with A.  This routine shifts that operator over to B.

  111525. */

  111526. SQLITE_PRIVATE void sqlite3SrcListShiftJoinType(SrcList *p){

  111527.   if( p ){

  111528.     int i;

  111529.     for(i=p->nSrc-1; i>0; i--){

  111530.       p->a[i].fg.jointype = p->a[i-1].fg.jointype;

  111531.     }

  111532.     p->a[0].fg.jointype = 0;

  111533.   }

  111534. }

  111535. 

  111536. /*

  111537. ** Generate VDBE code for a BEGIN statement.

  111538. */

  111539. SQLITE_PRIVATE void sqlite3BeginTransaction(Parse *pParse, int type){

  111540.   sqlite3 *db;

  111541.   Vdbe *v;

  111542.   int i;

  111543. 

  111544.   assert( pParse!=0 );

  111545.   db = pParse->db;

  111546.   assert( db!=0 );

  111547.   if( sqlite3AuthCheck(pParse, SQLITE_TRANSACTION, "BEGIN", 0, 0) ){

  111548.     return;

  111549.   }

  111550.   v = sqlite3GetVdbe(pParse);

  111551.   if( !v ) return;

  111552.   if( type!=TK_DEFERRED ){

  111553.     for(i=0; i<db->nDb; i++){

  111554.       sqlite3VdbeAddOp2(v, OP_Transaction, i, (type==TK_EXCLUSIVE)+1);

  111555.       sqlite3VdbeUsesBtree(v, i);

  111556.     }

  111557.   }

  111558.   sqlite3VdbeAddOp0(v, OP_AutoCommit);

  111559. }

  111560. 

  111561. /*

  111562. ** Generate VDBE code for a COMMIT or ROLLBACK statement.

  111563. ** Code for ROLLBACK is generated if eType==TK_ROLLBACK.  Otherwise

  111564. ** code is generated for a COMMIT.

  111565. */

  111566. SQLITE_PRIVATE void sqlite3EndTransaction(Parse *pParse, int eType){

  111567.   Vdbe *v;

  111568.   int isRollback;

  111569. 

  111570.   assert( pParse!=0 );

  111571.   assert( pParse->db!=0 );

  111572.   assert( eType==TK_COMMIT || eType==TK_END || eType==TK_ROLLBACK );

  111573.   isRollback = eType==TK_ROLLBACK;

  111574.   if( sqlite3AuthCheck(pParse, SQLITE_TRANSACTION, 

  111575.        isRollback ? "ROLLBACK" : "COMMIT", 0, 0) ){

  111576.     return;

  111577.   }

  111578.   v = sqlite3GetVdbe(pParse);

  111579.   if( v ){

  111580.     sqlite3VdbeAddOp2(v, OP_AutoCommit, 1, isRollback);

  111581.   }

  111582. }

  111583. 

  111584. /*

  111585. ** This function is called by the parser when it parses a command to create,

  111586. ** release or rollback an SQL savepoint. 

  111587. */

  111588. SQLITE_PRIVATE void sqlite3Savepoint(Parse *pParse, int op, Token *pName){

  111589.   char *zName = sqlite3NameFromToken(pParse->db, pName);

  111590.   if( zName ){

  111591.     Vdbe *v = sqlite3GetVdbe(pParse);

  111592. #ifndef SQLITE_OMIT_AUTHORIZATION

  111593.     static const char * const az[] = { "BEGIN", "RELEASE", "ROLLBACK" };

  111594.     assert( !SAVEPOINT_BEGIN && SAVEPOINT_RELEASE==1 && SAVEPOINT_ROLLBACK==2 );

  111595. #endif

  111596.     if( !v || sqlite3AuthCheck(pParse, SQLITE_SAVEPOINT, az[op], zName, 0) ){

  111597.       sqlite3DbFree(pParse->db, zName);

  111598.       return;

  111599.     }

  111600.     sqlite3VdbeAddOp4(v, OP_Savepoint, op, 0, 0, zName, P4_DYNAMIC);

  111601.   }

  111602. }

  111603. 

  111604. /*

  111605. ** Make sure the TEMP database is open and available for use.  Return

  111606. ** the number of errors.  Leave any error messages in the pParse structure.

  111607. */

  111608. SQLITE_PRIVATE int sqlite3OpenTempDatabase(Parse *pParse){

  111609.   sqlite3 *db = pParse->db;

  111610.   if( db->aDb[1].pBt==0 && !pParse->explain ){

  111611.     int rc;

  111612.     Btree *pBt;

  111613.     static const int flags = 

  111614.           SQLITE_OPEN_READWRITE |

  111615.           SQLITE_OPEN_CREATE |

  111616.           SQLITE_OPEN_EXCLUSIVE |

  111617.           SQLITE_OPEN_DELETEONCLOSE |

  111618.           SQLITE_OPEN_TEMP_DB;

  111619. 

  111620.     rc = sqlite3BtreeOpen(db->pVfs, 0, db, &pBt, 0, flags);

  111621.     if( rc!=SQLITE_OK ){

  111622.       sqlite3ErrorMsg(pParse, "unable to open a temporary database "

  111623.         "file for storing temporary tables");

  111624.       pParse->rc = rc;

  111625.       return 1;

  111626.     }

  111627.     db->aDb[1].pBt = pBt;

  111628.     assert( db->aDb[1].pSchema );

  111629.     if( SQLITE_NOMEM==sqlite3BtreeSetPageSize(pBt, db->nextPagesize, -1, 0) ){

  111630.       sqlite3OomFault(db);

  111631.       return 1;

  111632.     }

  111633.   }

  111634.   return 0;

  111635. }

  111636. 

  111637. /*

  111638. ** Record the fact that the schema cookie will need to be verified

  111639. ** for database iDb.  The code to actually verify the schema cookie

  111640. ** will occur at the end of the top-level VDBE and will be generated

  111641. ** later, by sqlite3FinishCoding().

  111642. */

  111643. SQLITE_PRIVATE void sqlite3CodeVerifySchema(Parse *pParse, int iDb){

  111644.   Parse *pToplevel = sqlite3ParseToplevel(pParse);

  111645. 

  111646.   assert( iDb>=0 && iDb<pParse->db->nDb );

  111647.   assert( pParse->db->aDb[iDb].pBt!=0 || iDb==1 );

  111648.   assert( iDb<SQLITE_MAX_ATTACHED+2 );

  111649.   assert( sqlite3SchemaMutexHeld(pParse->db, iDb, 0) );

  111650.   if( DbMaskTest(pToplevel->cookieMask, iDb)==0 ){

  111651.     DbMaskSet(pToplevel->cookieMask, iDb);

  111652.     if( !OMIT_TEMPDB && iDb==1 ){

  111653.       sqlite3OpenTempDatabase(pToplevel);

  111654.     }

  111655.   }

  111656. }

  111657. 

  111658. /*

  111659. ** If argument zDb is NULL, then call sqlite3CodeVerifySchema() for each 

  111660. ** attached database. Otherwise, invoke it for the database named zDb only.

  111661. */

  111662. SQLITE_PRIVATE void sqlite3CodeVerifyNamedSchema(Parse *pParse, const char *zDb){

  111663.   sqlite3 *db = pParse->db;

  111664.   int i;

  111665.   for(i=0; i<db->nDb; i++){

  111666.     Db *pDb = &db->aDb[i];

  111667.     if( pDb->pBt && (!zDb || 0==sqlite3StrICmp(zDb, pDb->zDbSName)) ){

  111668.       sqlite3CodeVerifySchema(pParse, i);

  111669.     }

  111670.   }

  111671. }

  111672. 

  111673. /*

  111674. ** Generate VDBE code that prepares for doing an operation that

  111675. ** might change the database.

  111676. **

  111677. ** This routine starts a new transaction if we are not already within

  111678. ** a transaction.  If we are already within a transaction, then a checkpoint

  111679. ** is set if the setStatement parameter is true.  A checkpoint should

  111680. ** be set for operations that might fail (due to a constraint) part of

  111681. ** the way through and which will need to undo some writes without having to

  111682. ** rollback the whole transaction.  For operations where all constraints

  111683. ** can be checked before any changes are made to the database, it is never

  111684. ** necessary to undo a write and the checkpoint should not be set.

  111685. */

  111686. SQLITE_PRIVATE void sqlite3BeginWriteOperation(Parse *pParse, int setStatement, int iDb){

  111687.   Parse *pToplevel = sqlite3ParseToplevel(pParse);

  111688.   sqlite3CodeVerifySchema(pParse, iDb);

  111689.   DbMaskSet(pToplevel->writeMask, iDb);

  111690.   pToplevel->isMultiWrite |= setStatement;

  111691. }

  111692. 

  111693. /*

  111694. ** Indicate that the statement currently under construction might write

  111695. ** more than one entry (example: deleting one row then inserting another,

  111696. ** inserting multiple rows in a table, or inserting a row and index entries.)

  111697. ** If an abort occurs after some of these writes have completed, then it will

  111698. ** be necessary to undo the completed writes.

  111699. */

  111700. SQLITE_PRIVATE void sqlite3MultiWrite(Parse *pParse){

  111701.   Parse *pToplevel = sqlite3ParseToplevel(pParse);

  111702.   pToplevel->isMultiWrite = 1;

  111703. }

  111704. 

  111705. /* 

  111706. ** The code generator calls this routine if is discovers that it is

  111707. ** possible to abort a statement prior to completion.  In order to 

  111708. ** perform this abort without corrupting the database, we need to make

  111709. ** sure that the statement is protected by a statement transaction.

  111710. **

  111711. ** Technically, we only need to set the mayAbort flag if the

  111712. ** isMultiWrite flag was previously set.  There is a time dependency

  111713. ** such that the abort must occur after the multiwrite.  This makes

  111714. ** some statements involving the REPLACE conflict resolution algorithm

  111715. ** go a little faster.  But taking advantage of this time dependency

  111716. ** makes it more difficult to prove that the code is correct (in 

  111717. ** particular, it prevents us from writing an effective

  111718. ** implementation of sqlite3AssertMayAbort()) and so we have chosen

  111719. ** to take the safe route and skip the optimization.

  111720. */

  111721. SQLITE_PRIVATE void sqlite3MayAbort(Parse *pParse){

  111722.   Parse *pToplevel = sqlite3ParseToplevel(pParse);

  111723.   pToplevel->mayAbort = 1;

  111724. }

  111725. 

  111726. /*

  111727. ** Code an OP_Halt that causes the vdbe to return an SQLITE_CONSTRAINT

  111728. ** error. The onError parameter determines which (if any) of the statement

  111729. ** and/or current transaction is rolled back.

  111730. */

  111731. SQLITE_PRIVATE void sqlite3HaltConstraint(

  111732.   Parse *pParse,    /* Parsing context */

  111733.   int errCode,      /* extended error code */

  111734.   int onError,      /* Constraint type */

  111735.   char *p4,         /* Error message */

  111736.   i8 p4type,        /* P4_STATIC or P4_TRANSIENT */

  111737.   u8 p5Errmsg       /* P5_ErrMsg type */

  111738. ){

  111739.   Vdbe *v = sqlite3GetVdbe(pParse);

  111740.   assert( (errCode&0xff)==SQLITE_CONSTRAINT );

  111741.   if( onError==OE_Abort ){

  111742.     sqlite3MayAbort(pParse);

  111743.   }

  111744.   sqlite3VdbeAddOp4(v, OP_Halt, errCode, onError, 0, p4, p4type);

  111745.   sqlite3VdbeChangeP5(v, p5Errmsg);

  111746. }

  111747. 

  111748. /*

  111749. ** Code an OP_Halt due to UNIQUE or PRIMARY KEY constraint violation.

  111750. */

  111751. SQLITE_PRIVATE void sqlite3UniqueConstraint(

  111752.   Parse *pParse,    /* Parsing context */

  111753.   int onError,      /* Constraint type */

  111754.   Index *pIdx       /* The index that triggers the constraint */

  111755. ){

  111756.   char *zErr;

  111757.   int j;

  111758.   StrAccum errMsg;

  111759.   Table *pTab = pIdx->pTable;

  111760. 

  111761.   sqlite3StrAccumInit(&errMsg, pParse->db, 0, 0, 

  111762.                       pParse->db->aLimit[SQLITE_LIMIT_LENGTH]);

  111763.   if( pIdx->aColExpr ){

  111764.     sqlite3_str_appendf(&errMsg, "index '%q'", pIdx->zName);

  111765.   }else{

  111766.     for(j=0; j<pIdx->nKeyCol; j++){

  111767.       char *zCol;

  111768.       assert( pIdx->aiColumn[j]>=0 );

  111769.       zCol = pTab->aCol[pIdx->aiColumn[j]].zName;

  111770.       if( j ) sqlite3_str_append(&errMsg, ", ", 2);

  111771.       sqlite3_str_appendall(&errMsg, pTab->zName);

  111772.       sqlite3_str_append(&errMsg, ".", 1);

  111773.       sqlite3_str_appendall(&errMsg, zCol);

  111774.     }

  111775.   }

  111776.   zErr = sqlite3StrAccumFinish(&errMsg);

  111777.   sqlite3HaltConstraint(pParse, 

  111778.     IsPrimaryKeyIndex(pIdx) ? SQLITE_CONSTRAINT_PRIMARYKEY 

  111779.                             : SQLITE_CONSTRAINT_UNIQUE,

  111780.     onError, zErr, P4_DYNAMIC, P5_ConstraintUnique);

  111781. }

  111782. 

  111783. 

  111784. /*

  111785. ** Code an OP_Halt due to non-unique rowid.

  111786. */

  111787. SQLITE_PRIVATE void sqlite3RowidConstraint(

  111788.   Parse *pParse,    /* Parsing context */

  111789.   int onError,      /* Conflict resolution algorithm */

  111790.   Table *pTab       /* The table with the non-unique rowid */ 

  111791. ){

  111792.   char *zMsg;

  111793.   int rc;

  111794.   if( pTab->iPKey>=0 ){

  111795.     zMsg = sqlite3MPrintf(pParse->db, "%s.%s", pTab->zName,

  111796.                           pTab->aCol[pTab->iPKey].zName);

  111797.     rc = SQLITE_CONSTRAINT_PRIMARYKEY;

  111798.   }else{

  111799.     zMsg = sqlite3MPrintf(pParse->db, "%s.rowid", pTab->zName);

  111800.     rc = SQLITE_CONSTRAINT_ROWID;

  111801.   }

  111802.   sqlite3HaltConstraint(pParse, rc, onError, zMsg, P4_DYNAMIC,

  111803.                         P5_ConstraintUnique);

  111804. }

  111805. 

  111806. /*

  111807. ** Check to see if pIndex uses the collating sequence pColl.  Return

  111808. ** true if it does and false if it does not.

  111809. */

  111810. #ifndef SQLITE_OMIT_REINDEX

  111811. static int collationMatch(const char *zColl, Index *pIndex){

  111812.   int i;

  111813.   assert( zColl!=0 );

  111814.   for(i=0; i<pIndex->nColumn; i++){

  111815.     const char *z = pIndex->azColl[i];

  111816.     assert( z!=0 || pIndex->aiColumn[i]<0 );

  111817.     if( pIndex->aiColumn[i]>=0 && 0==sqlite3StrICmp(z, zColl) ){

  111818.       return 1;

  111819.     }

  111820.   }

  111821.   return 0;

  111822. }

  111823. #endif

  111824. 

  111825. /*

  111826. ** Recompute all indices of pTab that use the collating sequence pColl.

  111827. ** If pColl==0 then recompute all indices of pTab.

  111828. */

  111829. #ifndef SQLITE_OMIT_REINDEX

  111830. static void reindexTable(Parse *pParse, Table *pTab, char const *zColl){

  111831.   if( !IsVirtual(pTab) ){

  111832.     Index *pIndex;              /* An index associated with pTab */

  111833. 

  111834.     for(pIndex=pTab->pIndex; pIndex; pIndex=pIndex->pNext){

  111835.       if( zColl==0 || collationMatch(zColl, pIndex) ){

  111836.         int iDb = sqlite3SchemaToIndex(pParse->db, pTab->pSchema);

  111837.         sqlite3BeginWriteOperation(pParse, 0, iDb);

  111838.         sqlite3RefillIndex(pParse, pIndex, -1);

  111839.       }

  111840.     }

  111841.   }

  111842. }

  111843. #endif

  111844. 

  111845. /*

  111846. ** Recompute all indices of all tables in all databases where the

  111847. ** indices use the collating sequence pColl.  If pColl==0 then recompute

  111848. ** all indices everywhere.

  111849. */

  111850. #ifndef SQLITE_OMIT_REINDEX

  111851. static void reindexDatabases(Parse *pParse, char const *zColl){

  111852.   Db *pDb;                    /* A single database */

  111853.   int iDb;                    /* The database index number */

  111854.   sqlite3 *db = pParse->db;   /* The database connection */

  111855.   HashElem *k;                /* For looping over tables in pDb */

  111856.   Table *pTab;                /* A table in the database */

  111857. 

  111858.   assert( sqlite3BtreeHoldsAllMutexes(db) );  /* Needed for schema access */

  111859.   for(iDb=0, pDb=db->aDb; iDb<db->nDb; iDb++, pDb++){

  111860.     assert( pDb!=0 );

  111861.     for(k=sqliteHashFirst(&pDb->pSchema->tblHash);  k; k=sqliteHashNext(k)){

  111862.       pTab = (Table*)sqliteHashData(k);

  111863.       reindexTable(pParse, pTab, zColl);

  111864.     }

  111865.   }

  111866. }

  111867. #endif

  111868. 

  111869. /*

  111870. ** Generate code for the REINDEX command.

  111871. **

  111872. **        REINDEX                            -- 1

  111873. **        REINDEX  <collation>               -- 2

  111874. **        REINDEX  ?<database>.?<tablename>  -- 3

  111875. **        REINDEX  ?<database>.?<indexname>  -- 4

  111876. **

  111877. ** Form 1 causes all indices in all attached databases to be rebuilt.

  111878. ** Form 2 rebuilds all indices in all databases that use the named

  111879. ** collating function.  Forms 3 and 4 rebuild the named index or all

  111880. ** indices associated with the named table.

  111881. */

  111882. #ifndef SQLITE_OMIT_REINDEX

  111883. SQLITE_PRIVATE void sqlite3Reindex(Parse *pParse, Token *pName1, Token *pName2){

  111884.   CollSeq *pColl;             /* Collating sequence to be reindexed, or NULL */

  111885.   char *z;                    /* Name of a table or index */

  111886.   const char *zDb;            /* Name of the database */

  111887.   Table *pTab;                /* A table in the database */

  111888.   Index *pIndex;              /* An index associated with pTab */

  111889.   int iDb;                    /* The database index number */

  111890.   sqlite3 *db = pParse->db;   /* The database connection */

  111891.   Token *pObjName;            /* Name of the table or index to be reindexed */

  111892. 

  111893.   /* Read the database schema. If an error occurs, leave an error message

  111894.   ** and code in pParse and return NULL. */

  111895.   if( SQLITE_OK!=sqlite3ReadSchema(pParse) ){

  111896.     return;

  111897.   }

  111898. 

  111899.   if( pName1==0 ){

  111900.     reindexDatabases(pParse, 0);

  111901.     return;

  111902.   }else if( NEVER(pName2==0) || pName2->z==0 ){

  111903.     char *zColl;

  111904.     assert( pName1->z );

  111905.     zColl = sqlite3NameFromToken(pParse->db, pName1);

  111906.     if( !zColl ) return;

  111907.     pColl = sqlite3FindCollSeq(db, ENC(db), zColl, 0);

  111908.     if( pColl ){

  111909.       reindexDatabases(pParse, zColl);

  111910.       sqlite3DbFree(db, zColl);

  111911.       return;

  111912.     }

  111913.     sqlite3DbFree(db, zColl);

  111914.   }

  111915.   iDb = sqlite3TwoPartName(pParse, pName1, pName2, &pObjName);

  111916.   if( iDb<0 ) return;

  111917.   z = sqlite3NameFromToken(db, pObjName);

  111918.   if( z==0 ) return;

  111919.   zDb = db->aDb[iDb].zDbSName;

  111920.   pTab = sqlite3FindTable(db, z, zDb);

  111921.   if( pTab ){

  111922.     reindexTable(pParse, pTab, 0);

  111923.     sqlite3DbFree(db, z);

  111924.     return;

  111925.   }

  111926.   pIndex = sqlite3FindIndex(db, z, zDb);

  111927.   sqlite3DbFree(db, z);

  111928.   if( pIndex ){

  111929.     sqlite3BeginWriteOperation(pParse, 0, iDb);

  111930.     sqlite3RefillIndex(pParse, pIndex, -1);

  111931.     return;

  111932.   }

  111933.   sqlite3ErrorMsg(pParse, "unable to identify the object to be reindexed");

  111934. }

  111935. #endif

  111936. 

  111937. /*

  111938. ** Return a KeyInfo structure that is appropriate for the given Index.

  111939. **

  111940. ** The caller should invoke sqlite3KeyInfoUnref() on the returned object

  111941. ** when it has finished using it.

  111942. */

  111943. SQLITE_PRIVATE KeyInfo *sqlite3KeyInfoOfIndex(Parse *pParse, Index *pIdx){

  111944.   int i;

  111945.   int nCol = pIdx->nColumn;

  111946.   int nKey = pIdx->nKeyCol;

  111947.   KeyInfo *pKey;

  111948.   if( pParse->nErr ) return 0;

  111949.   if( pIdx->uniqNotNull ){

  111950.     pKey = sqlite3KeyInfoAlloc(pParse->db, nKey, nCol-nKey);

  111951.   }else{

  111952.     pKey = sqlite3KeyInfoAlloc(pParse->db, nCol, 0);

  111953.   }

  111954.   if( pKey ){

  111955.     assert( sqlite3KeyInfoIsWriteable(pKey) );

  111956.     for(i=0; i<nCol; i++){

  111957.       const char *zColl = pIdx->azColl[i];

  111958.       pKey->aColl[i] = zColl==sqlite3StrBINARY ? 0 :

  111959.                         sqlite3LocateCollSeq(pParse, zColl);

  111960.       pKey->aSortOrder[i] = pIdx->aSortOrder[i];

  111961.     }

  111962.     if( pParse->nErr ){

  111963.       assert( pParse->rc==SQLITE_ERROR_MISSING_COLLSEQ );

  111964.       if( pIdx->bNoQuery==0 ){

  111965.         /* Deactivate the index because it contains an unknown collating

  111966.         ** sequence.  The only way to reactive the index is to reload the

  111967.         ** schema.  Adding the missing collating sequence later does not

  111968.         ** reactive the index.  The application had the chance to register

  111969.         ** the missing index using the collation-needed callback.  For

  111970.         ** simplicity, SQLite will not give the application a second chance.

  111971.         */

  111972.         pIdx->bNoQuery = 1;

  111973.         pParse->rc = SQLITE_ERROR_RETRY;

  111974.       }

  111975.       sqlite3KeyInfoUnref(pKey);

  111976.       pKey = 0;

  111977.     }

  111978.   }

  111979.   return pKey;

  111980. }

  111981. 

  111982. #ifndef SQLITE_OMIT_CTE

  111983. /* 

  111984. ** This routine is invoked once per CTE by the parser while parsing a 

  111985. ** WITH clause. 

  111986. */

  111987. SQLITE_PRIVATE With *sqlite3WithAdd(

  111988.   Parse *pParse,          /* Parsing context */

  111989.   With *pWith,            /* Existing WITH clause, or NULL */

  111990.   Token *pName,           /* Name of the common-table */

  111991.   ExprList *pArglist,     /* Optional column name list for the table */

  111992.   Select *pQuery          /* Query used to initialize the table */

  111993. ){

  111994.   sqlite3 *db = pParse->db;

  111995.   With *pNew;

  111996.   char *zName;

  111997. 

  111998.   /* Check that the CTE name is unique within this WITH clause. If

  111999.   ** not, store an error in the Parse structure. */

  112000.   zName = sqlite3NameFromToken(pParse->db, pName);

  112001.   if( zName && pWith ){

  112002.     int i;

  112003.     for(i=0; i<pWith->nCte; i++){

  112004.       if( sqlite3StrICmp(zName, pWith->a[i].zName)==0 ){

  112005.         sqlite3ErrorMsg(pParse, "duplicate WITH table name: %s", zName);

  112006.       }

  112007.     }

  112008.   }

  112009. 

  112010.   if( pWith ){

  112011.     sqlite3_int64 nByte = sizeof(*pWith) + (sizeof(pWith->a[1]) * pWith->nCte);

  112012.     pNew = sqlite3DbRealloc(db, pWith, nByte);

  112013.   }else{

  112014.     pNew = sqlite3DbMallocZero(db, sizeof(*pWith));

  112015.   }

  112016.   assert( (pNew!=0 && zName!=0) || db->mallocFailed );

  112017. 

  112018.   if( db->mallocFailed ){

  112019.     sqlite3ExprListDelete(db, pArglist);

  112020.     sqlite3SelectDelete(db, pQuery);

  112021.     sqlite3DbFree(db, zName);

  112022.     pNew = pWith;

  112023.   }else{

  112024.     pNew->a[pNew->nCte].pSelect = pQuery;

  112025.     pNew->a[pNew->nCte].pCols = pArglist;

  112026.     pNew->a[pNew->nCte].zName = zName;

  112027.     pNew->a[pNew->nCte].zCteErr = 0;

  112028.     pNew->nCte++;

  112029.   }

  112030. 

  112031.   return pNew;

  112032. }

  112033. 

  112034. /*

  112035. ** Free the contents of the With object passed as the second argument.

  112036. */

  112037. SQLITE_PRIVATE void sqlite3WithDelete(sqlite3 *db, With *pWith){

  112038.   if( pWith ){

  112039.     int i;

  112040.     for(i=0; i<pWith->nCte; i++){

  112041.       struct Cte *pCte = &pWith->a[i];

  112042.       sqlite3ExprListDelete(db, pCte->pCols);

  112043.       sqlite3SelectDelete(db, pCte->pSelect);

  112044.       sqlite3DbFree(db, pCte->zName);

  112045.     }

  112046.     sqlite3DbFree(db, pWith);

  112047.   }

  112048. }

  112049. #endif /* !defined(SQLITE_OMIT_CTE) */

  112050. 

  112051. /************** End of build.c ***********************************************/

  112052. /************** Begin file callback.c ****************************************/

  112053. /*

  112054. ** 2005 May 23 

  112055. **

  112056. ** The author disclaims copyright to this source code.  In place of

  112057. ** a legal notice, here is a blessing:

  112058. **

  112059. **    May you do good and not evil.

  112060. **    May you find forgiveness for yourself and forgive others.

  112061. **    May you share freely, never taking more than you give.

  112062. **

  112063. *************************************************************************

  112064. **

  112065. ** This file contains functions used to access the internal hash tables

  112066. ** of user defined functions and collation sequences.

  112067. */

  112068. 

  112069. /* #include "sqliteInt.h" */

  112070. 

  112071. /*

  112072. ** Invoke the 'collation needed' callback to request a collation sequence

  112073. ** in the encoding enc of name zName, length nName.

  112074. */

  112075. static void callCollNeeded(sqlite3 *db, int enc, const char *zName){

  112076.   assert( !db->xCollNeeded || !db->xCollNeeded16 );

  112077.   if( db->xCollNeeded ){

  112078.     char *zExternal = sqlite3DbStrDup(db, zName);

  112079.     if( !zExternal ) return;

  112080.     db->xCollNeeded(db->pCollNeededArg, db, enc, zExternal);

  112081.     sqlite3DbFree(db, zExternal);

  112082.   }

  112083. #ifndef SQLITE_OMIT_UTF16

  112084.   if( db->xCollNeeded16 ){

  112085.     char const *zExternal;

  112086.     sqlite3_value *pTmp = sqlite3ValueNew(db);

  112087.     sqlite3ValueSetStr(pTmp, -1, zName, SQLITE_UTF8, SQLITE_STATIC);

  112088.     zExternal = sqlite3ValueText(pTmp, SQLITE_UTF16NATIVE);

  112089.     if( zExternal ){

  112090.       db->xCollNeeded16(db->pCollNeededArg, db, (int)ENC(db), zExternal);

  112091.     }

  112092.     sqlite3ValueFree(pTmp);

  112093.   }

  112094. #endif

  112095. }

  112096. 

  112097. /*

  112098. ** This routine is called if the collation factory fails to deliver a

  112099. ** collation function in the best encoding but there may be other versions

  112100. ** of this collation function (for other text encodings) available. Use one

  112101. ** of these instead if they exist. Avoid a UTF-8 <-> UTF-16 conversion if

  112102. ** possible.

  112103. */

  112104. static int synthCollSeq(sqlite3 *db, CollSeq *pColl){

  112105.   CollSeq *pColl2;

  112106.   char *z = pColl->zName;

  112107.   int i;

  112108.   static const u8 aEnc[] = { SQLITE_UTF16BE, SQLITE_UTF16LE, SQLITE_UTF8 };

  112109.   for(i=0; i<3; i++){

  112110.     pColl2 = sqlite3FindCollSeq(db, aEnc[i], z, 0);

  112111.     if( pColl2->xCmp!=0 ){

  112112.       memcpy(pColl, pColl2, sizeof(CollSeq));

  112113.       pColl->xDel = 0;         /* Do not copy the destructor */

  112114.       return SQLITE_OK;

  112115.     }

  112116.   }

  112117.   return SQLITE_ERROR;

  112118. }

  112119. 

  112120. /*

  112121. ** This function is responsible for invoking the collation factory callback

  112122. ** or substituting a collation sequence of a different encoding when the

  112123. ** requested collation sequence is not available in the desired encoding.

  112124. ** 

  112125. ** If it is not NULL, then pColl must point to the database native encoding 

  112126. ** collation sequence with name zName, length nName.

  112127. **

  112128. ** The return value is either the collation sequence to be used in database

  112129. ** db for collation type name zName, length nName, or NULL, if no collation

  112130. ** sequence can be found.  If no collation is found, leave an error message.

  112131. **

  112132. ** See also: sqlite3LocateCollSeq(), sqlite3FindCollSeq()

  112133. */

  112134. SQLITE_PRIVATE CollSeq *sqlite3GetCollSeq(

  112135.   Parse *pParse,        /* Parsing context */

  112136.   u8 enc,               /* The desired encoding for the collating sequence */

  112137.   CollSeq *pColl,       /* Collating sequence with native encoding, or NULL */

  112138.   const char *zName     /* Collating sequence name */

  112139. ){

  112140.   CollSeq *p;

  112141.   sqlite3 *db = pParse->db;

  112142. 

  112143.   p = pColl;

  112144.   if( !p ){

  112145.     p = sqlite3FindCollSeq(db, enc, zName, 0);

  112146.   }

  112147.   if( !p || !p->xCmp ){

  112148.     /* No collation sequence of this type for this encoding is registered.

  112149.     ** Call the collation factory to see if it can supply us with one.

  112150.     */

  112151.     callCollNeeded(db, enc, zName);

  112152.     p = sqlite3FindCollSeq(db, enc, zName, 0);

  112153.   }

  112154.   if( p && !p->xCmp && synthCollSeq(db, p) ){

  112155.     p = 0;

  112156.   }

  112157.   assert( !p || p->xCmp );

  112158.   if( p==0 ){

  112159.     sqlite3ErrorMsg(pParse, "no such collation sequence: %s", zName);

  112160.     pParse->rc = SQLITE_ERROR_MISSING_COLLSEQ;

  112161.   }

  112162.   return p;

  112163. }

  112164. 

  112165. /*

  112166. ** This routine is called on a collation sequence before it is used to

  112167. ** check that it is defined. An undefined collation sequence exists when

  112168. ** a database is loaded that contains references to collation sequences

  112169. ** that have not been defined by sqlite3_create_collation() etc.

  112170. **

  112171. ** If required, this routine calls the 'collation needed' callback to

  112172. ** request a definition of the collating sequence. If this doesn't work, 

  112173. ** an equivalent collating sequence that uses a text encoding different

  112174. ** from the main database is substituted, if one is available.

  112175. */

  112176. SQLITE_PRIVATE int sqlite3CheckCollSeq(Parse *pParse, CollSeq *pColl){

  112177.   if( pColl && pColl->xCmp==0 ){

  112178.     const char *zName = pColl->zName;

  112179.     sqlite3 *db = pParse->db;

  112180.     CollSeq *p = sqlite3GetCollSeq(pParse, ENC(db), pColl, zName);

  112181.     if( !p ){

  112182.       return SQLITE_ERROR;

  112183.     }

  112184.     assert( p==pColl );

  112185.   }

  112186.   return SQLITE_OK;

  112187. }

  112188. 

  112189. 

  112190. 

  112191. /*

  112192. ** Locate and return an entry from the db.aCollSeq hash table. If the entry

  112193. ** specified by zName and nName is not found and parameter 'create' is

  112194. ** true, then create a new entry. Otherwise return NULL.

  112195. **

  112196. ** Each pointer stored in the sqlite3.aCollSeq hash table contains an

  112197. ** array of three CollSeq structures. The first is the collation sequence

  112198. ** preferred for UTF-8, the second UTF-16le, and the third UTF-16be.

  112199. **

  112200. ** Stored immediately after the three collation sequences is a copy of

  112201. ** the collation sequence name. A pointer to this string is stored in

  112202. ** each collation sequence structure.

  112203. */

  112204. static CollSeq *findCollSeqEntry(

  112205.   sqlite3 *db,          /* Database connection */

  112206.   const char *zName,    /* Name of the collating sequence */

  112207.   int create            /* Create a new entry if true */

  112208. ){

  112209.   CollSeq *pColl;

  112210.   pColl = sqlite3HashFind(&db->aCollSeq, zName);

  112211. 

  112212.   if( 0==pColl && create ){

  112213.     int nName = sqlite3Strlen30(zName) + 1;

  112214.     pColl = sqlite3DbMallocZero(db, 3*sizeof(*pColl) + nName);

  112215.     if( pColl ){

  112216.       CollSeq *pDel = 0;

  112217.       pColl[0].zName = (char*)&pColl[3];

  112218.       pColl[0].enc = SQLITE_UTF8;

  112219.       pColl[1].zName = (char*)&pColl[3];

  112220.       pColl[1].enc = SQLITE_UTF16LE;

  112221.       pColl[2].zName = (char*)&pColl[3];

  112222.       pColl[2].enc = SQLITE_UTF16BE;

  112223.       memcpy(pColl[0].zName, zName, nName);

  112224.       pDel = sqlite3HashInsert(&db->aCollSeq, pColl[0].zName, pColl);

  112225. 

  112226.       /* If a malloc() failure occurred in sqlite3HashInsert(), it will 

  112227.       ** return the pColl pointer to be deleted (because it wasn't added

  112228.       ** to the hash table).

  112229.       */

  112230.       assert( pDel==0 || pDel==pColl );

  112231.       if( pDel!=0 ){

  112232.         sqlite3OomFault(db);

  112233.         sqlite3DbFree(db, pDel);

  112234.         pColl = 0;

  112235.       }

  112236.     }

  112237.   }

  112238.   return pColl;

  112239. }

  112240. 

  112241. /*

  112242. ** Parameter zName points to a UTF-8 encoded string nName bytes long.

  112243. ** Return the CollSeq* pointer for the collation sequence named zName

  112244. ** for the encoding 'enc' from the database 'db'.

  112245. **

  112246. ** If the entry specified is not found and 'create' is true, then create a

  112247. ** new entry.  Otherwise return NULL.

  112248. **

  112249. ** A separate function sqlite3LocateCollSeq() is a wrapper around

  112250. ** this routine.  sqlite3LocateCollSeq() invokes the collation factory

  112251. ** if necessary and generates an error message if the collating sequence

  112252. ** cannot be found.

  112253. **

  112254. ** See also: sqlite3LocateCollSeq(), sqlite3GetCollSeq()

  112255. */

  112256. SQLITE_PRIVATE CollSeq *sqlite3FindCollSeq(

  112257.   sqlite3 *db,

  112258.   u8 enc,

  112259.   const char *zName,

  112260.   int create

  112261. ){

  112262.   CollSeq *pColl;

  112263.   if( zName ){

  112264.     pColl = findCollSeqEntry(db, zName, create);

  112265.   }else{

  112266.     pColl = db->pDfltColl;

  112267.   }

  112268.   assert( SQLITE_UTF8==1 && SQLITE_UTF16LE==2 && SQLITE_UTF16BE==3 );

  112269.   assert( enc>=SQLITE_UTF8 && enc<=SQLITE_UTF16BE );

  112270.   if( pColl ) pColl += enc-1;

  112271.   return pColl;

  112272. }

  112273. 

  112274. /* During the search for the best function definition, this procedure

  112275. ** is called to test how well the function passed as the first argument

  112276. ** matches the request for a function with nArg arguments in a system

  112277. ** that uses encoding enc. The value returned indicates how well the

  112278. ** request is matched. A higher value indicates a better match.

  112279. **

  112280. ** If nArg is -1 that means to only return a match (non-zero) if p->nArg

  112281. ** is also -1.  In other words, we are searching for a function that

  112282. ** takes a variable number of arguments.

  112283. **

  112284. ** If nArg is -2 that means that we are searching for any function 

  112285. ** regardless of the number of arguments it uses, so return a positive

  112286. ** match score for any

  112287. **

  112288. ** The returned value is always between 0 and 6, as follows:

  112289. **

  112290. ** 0: Not a match.

  112291. ** 1: UTF8/16 conversion required and function takes any number of arguments.

  112292. ** 2: UTF16 byte order change required and function takes any number of args.

  112293. ** 3: encoding matches and function takes any number of arguments

  112294. ** 4: UTF8/16 conversion required - argument count matches exactly

  112295. ** 5: UTF16 byte order conversion required - argument count matches exactly

  112296. ** 6: Perfect match:  encoding and argument count match exactly.

  112297. **

  112298. ** If nArg==(-2) then any function with a non-null xSFunc is

  112299. ** a perfect match and any function with xSFunc NULL is

  112300. ** a non-match.

  112301. */

  112302. #define FUNC_PERFECT_MATCH 6  /* The score for a perfect match */

  112303. static int matchQuality(

  112304.   FuncDef *p,     /* The function we are evaluating for match quality */

  112305.   int nArg,       /* Desired number of arguments.  (-1)==any */

  112306.   u8 enc          /* Desired text encoding */

  112307. ){

  112308.   int match;

  112309. 

  112310.   /* nArg of -2 is a special case */

  112311.   if( nArg==(-2) ) return (p->xSFunc==0) ? 0 : FUNC_PERFECT_MATCH;

  112312. 

  112313.   /* Wrong number of arguments means "no match" */

  112314.   if( p->nArg!=nArg && p->nArg>=0 ) return 0;

  112315. 

  112316.   /* Give a better score to a function with a specific number of arguments

  112317.   ** than to function that accepts any number of arguments. */

  112318.   if( p->nArg==nArg ){

  112319.     match = 4;

  112320.   }else{

  112321.     match = 1;

  112322.   }

  112323. 

  112324.   /* Bonus points if the text encoding matches */

  112325.   if( enc==(p->funcFlags & SQLITE_FUNC_ENCMASK) ){

  112326.     match += 2;  /* Exact encoding match */

  112327.   }else if( (enc & p->funcFlags & 2)!=0 ){

  112328.     match += 1;  /* Both are UTF16, but with different byte orders */

  112329.   }

  112330. 

  112331.   return match;

  112332. }

  112333. 

  112334. /*

  112335. ** Search a FuncDefHash for a function with the given name.  Return

  112336. ** a pointer to the matching FuncDef if found, or 0 if there is no match.

  112337. */

  112338. SQLITE_PRIVATE FuncDef *sqlite3FunctionSearch(

  112339.   int h,               /* Hash of the name */

  112340.   const char *zFunc    /* Name of function */

  112341. ){

  112342.   FuncDef *p;

  112343.   for(p=sqlite3BuiltinFunctions.a[h]; p; p=p->u.pHash){

  112344.     if( sqlite3StrICmp(p->zName, zFunc)==0 ){

  112345.       return p;

  112346.     }

  112347.   }

  112348.   return 0;

  112349. }

  112350. 

  112351. /*

  112352. ** Insert a new FuncDef into a FuncDefHash hash table.

  112353. */

  112354. SQLITE_PRIVATE void sqlite3InsertBuiltinFuncs(

  112355.   FuncDef *aDef,      /* List of global functions to be inserted */

  112356.   int nDef            /* Length of the apDef[] list */

  112357. ){

  112358.   int i;

  112359.   for(i=0; i<nDef; i++){

  112360.     FuncDef *pOther;

  112361.     const char *zName = aDef[i].zName;

  112362.     int nName = sqlite3Strlen30(zName);

  112363.     int h = SQLITE_FUNC_HASH(zName[0], nName);

  112364.     assert( zName[0]>='a' && zName[0]<='z' );

  112365.     pOther = sqlite3FunctionSearch(h, zName);

  112366.     if( pOther ){

  112367.       assert( pOther!=&aDef[i] && pOther->pNext!=&aDef[i] );

  112368.       aDef[i].pNext = pOther->pNext;

  112369.       pOther->pNext = &aDef[i];

  112370.     }else{

  112371.       aDef[i].pNext = 0;

  112372.       aDef[i].u.pHash = sqlite3BuiltinFunctions.a[h];

  112373.       sqlite3BuiltinFunctions.a[h] = &aDef[i];

  112374.     }

  112375.   }

  112376. }

  112377.   

  112378.   

  112379. 

  112380. /*

  112381. ** Locate a user function given a name, a number of arguments and a flag

  112382. ** indicating whether the function prefers UTF-16 over UTF-8.  Return a

  112383. ** pointer to the FuncDef structure that defines that function, or return

  112384. ** NULL if the function does not exist.

  112385. **

  112386. ** If the createFlag argument is true, then a new (blank) FuncDef

  112387. ** structure is created and liked into the "db" structure if a

  112388. ** no matching function previously existed.

  112389. **

  112390. ** If nArg is -2, then the first valid function found is returned.  A

  112391. ** function is valid if xSFunc is non-zero.  The nArg==(-2)

  112392. ** case is used to see if zName is a valid function name for some number

  112393. ** of arguments.  If nArg is -2, then createFlag must be 0.

  112394. **

  112395. ** If createFlag is false, then a function with the required name and

  112396. ** number of arguments may be returned even if the eTextRep flag does not

  112397. ** match that requested.

  112398. */

  112399. SQLITE_PRIVATE FuncDef *sqlite3FindFunction(

  112400.   sqlite3 *db,       /* An open database */

  112401.   const char *zName, /* Name of the function.  zero-terminated */

  112402.   int nArg,          /* Number of arguments.  -1 means any number */

  112403.   u8 enc,            /* Preferred text encoding */

  112404.   u8 createFlag      /* Create new entry if true and does not otherwise exist */

  112405. ){

  112406.   FuncDef *p;         /* Iterator variable */

  112407.   FuncDef *pBest = 0; /* Best match found so far */

  112408.   int bestScore = 0;  /* Score of best match */

  112409.   int h;              /* Hash value */

  112410.   int nName;          /* Length of the name */

  112411. 

  112412.   assert( nArg>=(-2) );

  112413.   assert( nArg>=(-1) || createFlag==0 );

  112414.   nName = sqlite3Strlen30(zName);

  112415. 

  112416.   /* First search for a match amongst the application-defined functions.

  112417.   */

  112418.   p = (FuncDef*)sqlite3HashFind(&db->aFunc, zName);

  112419.   while( p ){

  112420.     int score = matchQuality(p, nArg, enc);

  112421.     if( score>bestScore ){

  112422.       pBest = p;

  112423.       bestScore = score;

  112424.     }

  112425.     p = p->pNext;

  112426.   }

  112427. 

  112428.   /* If no match is found, search the built-in functions.

  112429.   **

  112430.   ** If the DBFLAG_PreferBuiltin flag is set, then search the built-in

  112431.   ** functions even if a prior app-defined function was found.  And give

  112432.   ** priority to built-in functions.

  112433.   **

  112434.   ** Except, if createFlag is true, that means that we are trying to

  112435.   ** install a new function.  Whatever FuncDef structure is returned it will

  112436.   ** have fields overwritten with new information appropriate for the

  112437.   ** new function.  But the FuncDefs for built-in functions are read-only.

  112438.   ** So we must not search for built-ins when creating a new function.

  112439.   */ 

  112440.   if( !createFlag && (pBest==0 || (db->mDbFlags & DBFLAG_PreferBuiltin)!=0) ){

  112441.     bestScore = 0;

  112442.     h = SQLITE_FUNC_HASH(sqlite3UpperToLower[(u8)zName[0]], nName);

  112443.     p = sqlite3FunctionSearch(h, zName);

  112444.     while( p ){

  112445.       int score = matchQuality(p, nArg, enc);

  112446.       if( score>bestScore ){

  112447.         pBest = p;

  112448.         bestScore = score;

  112449.       }

  112450.       p = p->pNext;

  112451.     }

  112452.   }

  112453. 

  112454.   /* If the createFlag parameter is true and the search did not reveal an

  112455.   ** exact match for the name, number of arguments and encoding, then add a

  112456.   ** new entry to the hash table and return it.

  112457.   */

  112458.   if( createFlag && bestScore<FUNC_PERFECT_MATCH && 

  112459.       (pBest = sqlite3DbMallocZero(db, sizeof(*pBest)+nName+1))!=0 ){

  112460.     FuncDef *pOther;

  112461.     u8 *z;

  112462.     pBest->zName = (const char*)&pBest[1];

  112463.     pBest->nArg = (u16)nArg;

  112464.     pBest->funcFlags = enc;

  112465.     memcpy((char*)&pBest[1], zName, nName+1);

  112466.     for(z=(u8*)pBest->zName; *z; z++) *z = sqlite3UpperToLower[*z];

  112467.     pOther = (FuncDef*)sqlite3HashInsert(&db->aFunc, pBest->zName, pBest);

  112468.     if( pOther==pBest ){

  112469.       sqlite3DbFree(db, pBest);

  112470.       sqlite3OomFault(db);

  112471.       return 0;

  112472.     }else{

  112473.       pBest->pNext = pOther;

  112474.     }

  112475.   }

  112476. 

  112477.   if( pBest && (pBest->xSFunc || createFlag) ){

  112478.     return pBest;

  112479.   }

  112480.   return 0;

  112481. }

  112482. 

  112483. /*

  112484. ** Free all resources held by the schema structure. The void* argument points

  112485. ** at a Schema struct. This function does not call sqlite3DbFree(db, ) on the 

  112486. ** pointer itself, it just cleans up subsidiary resources (i.e. the contents

  112487. ** of the schema hash tables).

  112488. **

  112489. ** The Schema.cache_size variable is not cleared.

  112490. */

  112491. SQLITE_PRIVATE void sqlite3SchemaClear(void *p){

  112492.   Hash temp1;

  112493.   Hash temp2;

  112494.   HashElem *pElem;

  112495.   Schema *pSchema = (Schema *)p;

  112496. 

  112497.   temp1 = pSchema->tblHash;

  112498.   temp2 = pSchema->trigHash;

  112499.   sqlite3HashInit(&pSchema->trigHash);

  112500.   sqlite3HashClear(&pSchema->idxHash);

  112501.   for(pElem=sqliteHashFirst(&temp2); pElem; pElem=sqliteHashNext(pElem)){

  112502.     sqlite3DeleteTrigger(0, (Trigger*)sqliteHashData(pElem));

  112503.   }

  112504.   sqlite3HashClear(&temp2);

  112505.   sqlite3HashInit(&pSchema->tblHash);

  112506.   for(pElem=sqliteHashFirst(&temp1); pElem; pElem=sqliteHashNext(pElem)){

  112507.     Table *pTab = sqliteHashData(pElem);

  112508.     sqlite3DeleteTable(0, pTab);

  112509.   }

  112510.   sqlite3HashClear(&temp1);

  112511.   sqlite3HashClear(&pSchema->fkeyHash);

  112512.   pSchema->pSeqTab = 0;

  112513.   if( pSchema->schemaFlags & DB_SchemaLoaded ){

  112514.     pSchema->iGeneration++;

  112515.   }

  112516.   pSchema->schemaFlags &= ~(DB_SchemaLoaded|DB_ResetWanted);

  112517. }

  112518. 

  112519. /*

  112520. ** Find and return the schema associated with a BTree.  Create

  112521. ** a new one if necessary.

  112522. */

  112523. SQLITE_PRIVATE Schema *sqlite3SchemaGet(sqlite3 *db, Btree *pBt){

  112524.   Schema * p;

  112525.   if( pBt ){

  112526.     p = (Schema *)sqlite3BtreeSchema(pBt, sizeof(Schema), sqlite3SchemaClear);

  112527.   }else{

  112528.     p = (Schema *)sqlite3DbMallocZero(0, sizeof(Schema));

  112529.   }

  112530.   if( !p ){

  112531.     sqlite3OomFault(db);

  112532.   }else if ( 0==p->file_format ){

  112533.     sqlite3HashInit(&p->tblHash);

  112534.     sqlite3HashInit(&p->idxHash);

  112535.     sqlite3HashInit(&p->trigHash);

  112536.     sqlite3HashInit(&p->fkeyHash);

  112537.     p->enc = SQLITE_UTF8;

  112538.   }

  112539.   return p;

  112540. }

  112541. 

  112542. /************** End of callback.c ********************************************/

  112543. /************** Begin file delete.c ******************************************/

  112544. /*

  112545. ** 2001 September 15

  112546. **

  112547. ** The author disclaims copyright to this source code.  In place of

  112548. ** a legal notice, here is a blessing:

  112549. **

  112550. **    May you do good and not evil.

  112551. **    May you find forgiveness for yourself and forgive others.

  112552. **    May you share freely, never taking more than you give.

  112553. **

  112554. *************************************************************************

  112555. ** This file contains C code routines that are called by the parser

  112556. ** in order to generate code for DELETE FROM statements.

  112557. */

  112558. /* #include "sqliteInt.h" */

  112559. 

  112560. /*

  112561. ** While a SrcList can in general represent multiple tables and subqueries

  112562. ** (as in the FROM clause of a SELECT statement) in this case it contains

  112563. ** the name of a single table, as one might find in an INSERT, DELETE,

  112564. ** or UPDATE statement.  Look up that table in the symbol table and

  112565. ** return a pointer.  Set an error message and return NULL if the table 

  112566. ** name is not found or if any other error occurs.

  112567. **

  112568. ** The following fields are initialized appropriate in pSrc:

  112569. **

  112570. **    pSrc->a[0].pTab       Pointer to the Table object

  112571. **    pSrc->a[0].pIndex     Pointer to the INDEXED BY index, if there is one

  112572. **

  112573. */

  112574. SQLITE_PRIVATE Table *sqlite3SrcListLookup(Parse *pParse, SrcList *pSrc){

  112575.   struct SrcList_item *pItem = pSrc->a;

  112576.   Table *pTab;

  112577.   assert( pItem && pSrc->nSrc==1 );

  112578.   pTab = sqlite3LocateTableItem(pParse, 0, pItem);

  112579.   sqlite3DeleteTable(pParse->db, pItem->pTab);

  112580.   pItem->pTab = pTab;

  112581.   if( pTab ){

  112582.     pTab->nTabRef++;

  112583.   }

  112584.   if( sqlite3IndexedByLookup(pParse, pItem) ){

  112585.     pTab = 0;

  112586.   }

  112587.   return pTab;

  112588. }

  112589. 

  112590. /* Return true if table pTab is read-only.

  112591. **

  112592. ** A table is read-only if any of the following are true:

  112593. **

  112594. **   1) It is a virtual table and no implementation of the xUpdate method

  112595. **      has been provided

  112596. **

  112597. **   2) It is a system table (i.e. sqlite_master), this call is not

  112598. **      part of a nested parse and writable_schema pragma has not 

  112599. **      been specified

  112600. **

  112601. **   3) The table is a shadow table, the database connection is in

  112602. **      defensive mode, and the current sqlite3_prepare()

  112603. **      is for a top-level SQL statement.

  112604. */

  112605. static int tabIsReadOnly(Parse *pParse, Table *pTab){

  112606.   sqlite3 *db;

  112607.   if( IsVirtual(pTab) ){

  112608.     return sqlite3GetVTable(pParse->db, pTab)->pMod->pModule->xUpdate==0;

  112609.   }

  112610.   if( (pTab->tabFlags & (TF_Readonly|TF_Shadow))==0 ) return 0;

  112611.   db = pParse->db;

  112612.   if( (pTab->tabFlags & TF_Readonly)!=0 ){

  112613.     return sqlite3WritableSchema(db)==0 && pParse->nested==0;

  112614.   }

  112615.   assert( pTab->tabFlags & TF_Shadow );

  112616.   return (db->flags & SQLITE_Defensive)!=0 

  112617. #ifndef SQLITE_OMIT_VIRTUALTABLE

  112618.           && db->pVtabCtx==0

  112619. #endif

  112620.           && db->nVdbeExec==0;

  112621. }

  112622. 

  112623. /*

  112624. ** Check to make sure the given table is writable.  If it is not

  112625. ** writable, generate an error message and return 1.  If it is

  112626. ** writable return 0;

  112627. */

  112628. SQLITE_PRIVATE int sqlite3IsReadOnly(Parse *pParse, Table *pTab, int viewOk){

  112629.   if( tabIsReadOnly(pParse, pTab) ){

  112630.     sqlite3ErrorMsg(pParse, "table %s may not be modified", pTab->zName);

  112631.     return 1;

  112632.   }

  112633. #ifndef SQLITE_OMIT_VIEW

  112634.   if( !viewOk && pTab->pSelect ){

  112635.     sqlite3ErrorMsg(pParse,"cannot modify %s because it is a view",pTab->zName);

  112636.     return 1;

  112637.   }

  112638. #endif

  112639.   return 0;

  112640. }

  112641. 

  112642. 

  112643. #if !defined(SQLITE_OMIT_VIEW) && !defined(SQLITE_OMIT_TRIGGER)

  112644. /*

  112645. ** Evaluate a view and store its result in an ephemeral table.  The

  112646. ** pWhere argument is an optional WHERE clause that restricts the

  112647. ** set of rows in the view that are to be added to the ephemeral table.

  112648. */

  112649. SQLITE_PRIVATE void sqlite3MaterializeView(

  112650.   Parse *pParse,       /* Parsing context */

  112651.   Table *pView,        /* View definition */

  112652.   Expr *pWhere,        /* Optional WHERE clause to be added */

  112653.   ExprList *pOrderBy,  /* Optional ORDER BY clause */

  112654.   Expr *pLimit,        /* Optional LIMIT clause */

  112655.   int iCur             /* Cursor number for ephemeral table */

  112656. ){

  112657.   SelectDest dest;

  112658.   Select *pSel;

  112659.   SrcList *pFrom;

  112660.   sqlite3 *db = pParse->db;

  112661.   int iDb = sqlite3SchemaToIndex(db, pView->pSchema);

  112662.   pWhere = sqlite3ExprDup(db, pWhere, 0);

  112663.   pFrom = sqlite3SrcListAppend(pParse, 0, 0, 0);

  112664.   if( pFrom ){

  112665.     assert( pFrom->nSrc==1 );

  112666.     pFrom->a[0].zName = sqlite3DbStrDup(db, pView->zName);

  112667.     pFrom->a[0].zDatabase = sqlite3DbStrDup(db, db->aDb[iDb].zDbSName);

  112668.     assert( pFrom->a[0].pOn==0 );

  112669.     assert( pFrom->a[0].pUsing==0 );

  112670.   }

  112671.   pSel = sqlite3SelectNew(pParse, 0, pFrom, pWhere, 0, 0, pOrderBy, 

  112672.                           SF_IncludeHidden, pLimit);

  112673.   sqlite3SelectDestInit(&dest, SRT_EphemTab, iCur);

  112674.   sqlite3Select(pParse, pSel, &dest);

  112675.   sqlite3SelectDelete(db, pSel);

  112676. }

  112677. #endif /* !defined(SQLITE_OMIT_VIEW) && !defined(SQLITE_OMIT_TRIGGER) */

  112678. 

  112679. #if defined(SQLITE_ENABLE_UPDATE_DELETE_LIMIT) && !defined(SQLITE_OMIT_SUBQUERY)

  112680. /*

  112681. ** Generate an expression tree to implement the WHERE, ORDER BY,

  112682. ** and LIMIT/OFFSET portion of DELETE and UPDATE statements.

  112683. **

  112684. **     DELETE FROM table_wxyz WHERE a<5 ORDER BY a LIMIT 1;

  112685. **                            \__________________________/

  112686. **                               pLimitWhere (pInClause)

  112687. */

  112688. SQLITE_PRIVATE Expr *sqlite3LimitWhere(

  112689.   Parse *pParse,               /* The parser context */

  112690.   SrcList *pSrc,               /* the FROM clause -- which tables to scan */

  112691.   Expr *pWhere,                /* The WHERE clause.  May be null */

  112692.   ExprList *pOrderBy,          /* The ORDER BY clause.  May be null */

  112693.   Expr *pLimit,                /* The LIMIT clause.  May be null */

  112694.   char *zStmtType              /* Either DELETE or UPDATE.  For err msgs. */

  112695. ){

  112696.   sqlite3 *db = pParse->db;

  112697.   Expr *pLhs = NULL;           /* LHS of IN(SELECT...) operator */

  112698.   Expr *pInClause = NULL;      /* WHERE rowid IN ( select ) */

  112699.   ExprList *pEList = NULL;     /* Expression list contaning only pSelectRowid */

  112700.   SrcList *pSelectSrc = NULL;  /* SELECT rowid FROM x ... (dup of pSrc) */

  112701.   Select *pSelect = NULL;      /* Complete SELECT tree */

  112702.   Table *pTab;

  112703. 

  112704.   /* Check that there isn't an ORDER BY without a LIMIT clause.

  112705.   */

  112706.   if( pOrderBy && pLimit==0 ) {

  112707.     sqlite3ErrorMsg(pParse, "ORDER BY without LIMIT on %s", zStmtType);

  112708.     sqlite3ExprDelete(pParse->db, pWhere);

  112709.     sqlite3ExprListDelete(pParse->db, pOrderBy);

  112710.     return 0;

  112711.   }

  112712. 

  112713.   /* We only need to generate a select expression if there

  112714.   ** is a limit/offset term to enforce.

  112715.   */

  112716.   if( pLimit == 0 ) {

  112717.     return pWhere;

  112718.   }

  112719. 

  112720.   /* Generate a select expression tree to enforce the limit/offset 

  112721.   ** term for the DELETE or UPDATE statement.  For example:

  112722.   **   DELETE FROM table_a WHERE col1=1 ORDER BY col2 LIMIT 1 OFFSET 1

  112723.   ** becomes:

  112724.   **   DELETE FROM table_a WHERE rowid IN ( 

  112725.   **     SELECT rowid FROM table_a WHERE col1=1 ORDER BY col2 LIMIT 1 OFFSET 1

  112726.   **   );

  112727.   */

  112728. 

  112729.   pTab = pSrc->a[0].pTab;

  112730.   if( HasRowid(pTab) ){

  112731.     pLhs = sqlite3PExpr(pParse, TK_ROW, 0, 0);

  112732.     pEList = sqlite3ExprListAppend(

  112733.         pParse, 0, sqlite3PExpr(pParse, TK_ROW, 0, 0)

  112734.     );

  112735.   }else{

  112736.     Index *pPk = sqlite3PrimaryKeyIndex(pTab);

  112737.     if( pPk->nKeyCol==1 ){

  112738.       const char *zName = pTab->aCol[pPk->aiColumn[0]].zName;

  112739.       pLhs = sqlite3Expr(db, TK_ID, zName);

  112740.       pEList = sqlite3ExprListAppend(pParse, 0, sqlite3Expr(db, TK_ID, zName));

  112741.     }else{

  112742.       int i;

  112743.       for(i=0; i<pPk->nKeyCol; i++){

  112744.         Expr *p = sqlite3Expr(db, TK_ID, pTab->aCol[pPk->aiColumn[i]].zName);

  112745.         pEList = sqlite3ExprListAppend(pParse, pEList, p);

  112746.       }

  112747.       pLhs = sqlite3PExpr(pParse, TK_VECTOR, 0, 0);

  112748.       if( pLhs ){

  112749.         pLhs->x.pList = sqlite3ExprListDup(db, pEList, 0);

  112750.       }

  112751.     }

  112752.   }

  112753. 

  112754.   /* duplicate the FROM clause as it is needed by both the DELETE/UPDATE tree

  112755.   ** and the SELECT subtree. */

  112756.   pSrc->a[0].pTab = 0;

  112757.   pSelectSrc = sqlite3SrcListDup(pParse->db, pSrc, 0);

  112758.   pSrc->a[0].pTab = pTab;

  112759.   pSrc->a[0].pIBIndex = 0;

  112760. 

  112761.   /* generate the SELECT expression tree. */

  112762.   pSelect = sqlite3SelectNew(pParse, pEList, pSelectSrc, pWhere, 0 ,0, 

  112763.       pOrderBy,0,pLimit

  112764.   );

  112765. 

  112766.   /* now generate the new WHERE rowid IN clause for the DELETE/UDPATE */

  112767.   pInClause = sqlite3PExpr(pParse, TK_IN, pLhs, 0);

  112768.   sqlite3PExprAddSelect(pParse, pInClause, pSelect);

  112769.   return pInClause;

  112770. }

  112771. #endif /* defined(SQLITE_ENABLE_UPDATE_DELETE_LIMIT) */

  112772.        /*      && !defined(SQLITE_OMIT_SUBQUERY) */

  112773. 

  112774. /*

  112775. ** Generate code for a DELETE FROM statement.

  112776. **

  112777. **     DELETE FROM table_wxyz WHERE a<5 AND b NOT NULL;

  112778. **                 \________/       \________________/

  112779. **                  pTabList              pWhere

  112780. */

  112781. SQLITE_PRIVATE void sqlite3DeleteFrom(

  112782.   Parse *pParse,         /* The parser context */

  112783.   SrcList *pTabList,     /* The table from which we should delete things */

  112784.   Expr *pWhere,          /* The WHERE clause.  May be null */

  112785.   ExprList *pOrderBy,    /* ORDER BY clause. May be null */

  112786.   Expr *pLimit           /* LIMIT clause. May be null */

  112787. ){

  112788.   Vdbe *v;               /* The virtual database engine */

  112789.   Table *pTab;           /* The table from which records will be deleted */

  112790.   int i;                 /* Loop counter */

  112791.   WhereInfo *pWInfo;     /* Information about the WHERE clause */

  112792.   Index *pIdx;           /* For looping over indices of the table */

  112793.   int iTabCur;           /* Cursor number for the table */

  112794.   int iDataCur = 0;      /* VDBE cursor for the canonical data source */

  112795.   int iIdxCur = 0;       /* Cursor number of the first index */

  112796.   int nIdx;              /* Number of indices */

  112797.   sqlite3 *db;           /* Main database structure */

  112798.   AuthContext sContext;  /* Authorization context */

  112799.   NameContext sNC;       /* Name context to resolve expressions in */

  112800.   int iDb;               /* Database number */

  112801.   int memCnt = 0;        /* Memory cell used for change counting */

  112802.   int rcauth;            /* Value returned by authorization callback */

  112803.   int eOnePass;          /* ONEPASS_OFF or _SINGLE or _MULTI */

  112804.   int aiCurOnePass[2];   /* The write cursors opened by WHERE_ONEPASS */

  112805.   u8 *aToOpen = 0;       /* Open cursor iTabCur+j if aToOpen[j] is true */

  112806.   Index *pPk;            /* The PRIMARY KEY index on the table */

  112807.   int iPk = 0;           /* First of nPk registers holding PRIMARY KEY value */

  112808.   i16 nPk = 1;           /* Number of columns in the PRIMARY KEY */

  112809.   int iKey;              /* Memory cell holding key of row to be deleted */

  112810.   i16 nKey;              /* Number of memory cells in the row key */

  112811.   int iEphCur = 0;       /* Ephemeral table holding all primary key values */

  112812.   int iRowSet = 0;       /* Register for rowset of rows to delete */

  112813.   int addrBypass = 0;    /* Address of jump over the delete logic */

  112814.   int addrLoop = 0;      /* Top of the delete loop */

  112815.   int addrEphOpen = 0;   /* Instruction to open the Ephemeral table */

  112816.   int bComplex;          /* True if there are triggers or FKs or

  112817.                          ** subqueries in the WHERE clause */

  112818.  

  112819. #ifndef SQLITE_OMIT_TRIGGER

  112820.   int isView;                  /* True if attempting to delete from a view */

  112821.   Trigger *pTrigger;           /* List of table triggers, if required */

  112822. #endif

  112823. 

  112824.   memset(&sContext, 0, sizeof(sContext));

  112825.   db = pParse->db;

  112826.   if( pParse->nErr || db->mallocFailed ){

  112827.     goto delete_from_cleanup;

  112828.   }

  112829.   assert( pTabList->nSrc==1 );

  112830. 

  112831. 

  112832.   /* Locate the table which we want to delete.  This table has to be

  112833.   ** put in an SrcList structure because some of the subroutines we

  112834.   ** will be calling are designed to work with multiple tables and expect

  112835.   ** an SrcList* parameter instead of just a Table* parameter.

  112836.   */

  112837.   pTab = sqlite3SrcListLookup(pParse, pTabList);

  112838.   if( pTab==0 )  goto delete_from_cleanup;

  112839. 

  112840.   /* Figure out if we have any triggers and if the table being

  112841.   ** deleted from is a view

  112842.   */

  112843. #ifndef SQLITE_OMIT_TRIGGER

  112844.   pTrigger = sqlite3TriggersExist(pParse, pTab, TK_DELETE, 0, 0);

  112845.   isView = pTab->pSelect!=0;

  112846. #else

  112847. # define pTrigger 0

  112848. # define isView 0

  112849. #endif

  112850.   bComplex = pTrigger || sqlite3FkRequired(pParse, pTab, 0, 0);

  112851. #ifdef SQLITE_OMIT_VIEW

  112852. # undef isView

  112853. # define isView 0

  112854. #endif

  112855. 

  112856. #ifdef SQLITE_ENABLE_UPDATE_DELETE_LIMIT

  112857.   if( !isView ){

  112858.     pWhere = sqlite3LimitWhere(

  112859.         pParse, pTabList, pWhere, pOrderBy, pLimit, "DELETE"

  112860.     );

  112861.     pOrderBy = 0;

  112862.     pLimit = 0;

  112863.   }

  112864. #endif

  112865. 

  112866.   /* If pTab is really a view, make sure it has been initialized.

  112867.   */

  112868.   if( sqlite3ViewGetColumnNames(pParse, pTab) ){

  112869.     goto delete_from_cleanup;

  112870.   }

  112871. 

  112872.   if( sqlite3IsReadOnly(pParse, pTab, (pTrigger?1:0)) ){

  112873.     goto delete_from_cleanup;

  112874.   }

  112875.   iDb = sqlite3SchemaToIndex(db, pTab->pSchema);

  112876.   assert( iDb<db->nDb );

  112877.   rcauth = sqlite3AuthCheck(pParse, SQLITE_DELETE, pTab->zName, 0, 

  112878.                             db->aDb[iDb].zDbSName);

  112879.   assert( rcauth==SQLITE_OK || rcauth==SQLITE_DENY || rcauth==SQLITE_IGNORE );

  112880.   if( rcauth==SQLITE_DENY ){

  112881.     goto delete_from_cleanup;

  112882.   }

  112883.   assert(!isView || pTrigger);

  112884. 

  112885.   /* Assign cursor numbers to the table and all its indices.

  112886.   */

  112887.   assert( pTabList->nSrc==1 );

  112888.   iTabCur = pTabList->a[0].iCursor = pParse->nTab++;

  112889.   for(nIdx=0, pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext, nIdx++){

  112890.     pParse->nTab++;

  112891.   }

  112892. 

  112893.   /* Start the view context

  112894.   */

  112895.   if( isView ){

  112896.     sqlite3AuthContextPush(pParse, &sContext, pTab->zName);

  112897.   }

  112898. 

  112899.   /* Begin generating code.

  112900.   */

  112901.   v = sqlite3GetVdbe(pParse);

  112902.   if( v==0 ){

  112903.     goto delete_from_cleanup;

  112904.   }

  112905.   if( pParse->nested==0 ) sqlite3VdbeCountChanges(v);

  112906.   sqlite3BeginWriteOperation(pParse, bComplex, iDb);

  112907. 

  112908.   /* If we are trying to delete from a view, realize that view into

  112909.   ** an ephemeral table.

  112910.   */

  112911. #if !defined(SQLITE_OMIT_VIEW) && !defined(SQLITE_OMIT_TRIGGER)

  112912.   if( isView ){

  112913.     sqlite3MaterializeView(pParse, pTab, 

  112914.         pWhere, pOrderBy, pLimit, iTabCur

  112915.     );

  112916.     iDataCur = iIdxCur = iTabCur;

  112917.     pOrderBy = 0;

  112918.     pLimit = 0;

  112919.   }

  112920. #endif

  112921. 

  112922.   /* Resolve the column names in the WHERE clause.

  112923.   */

  112924.   memset(&sNC, 0, sizeof(sNC));

  112925.   sNC.pParse = pParse;

  112926.   sNC.pSrcList = pTabList;

  112927.   if( sqlite3ResolveExprNames(&sNC, pWhere) ){

  112928.     goto delete_from_cleanup;

  112929.   }

  112930. 

  112931.   /* Initialize the counter of the number of rows deleted, if

  112932.   ** we are counting rows.

  112933.   */

  112934.   if( (db->flags & SQLITE_CountRows)!=0

  112935.    && !pParse->nested

  112936.    && !pParse->pTriggerTab

  112937.   ){

  112938.     memCnt = ++pParse->nMem;

  112939.     sqlite3VdbeAddOp2(v, OP_Integer, 0, memCnt);

  112940.   }

  112941. 

  112942. #ifndef SQLITE_OMIT_TRUNCATE_OPTIMIZATION

  112943.   /* Special case: A DELETE without a WHERE clause deletes everything.

  112944.   ** It is easier just to erase the whole table. Prior to version 3.6.5,

  112945.   ** this optimization caused the row change count (the value returned by 

  112946.   ** API function sqlite3_count_changes) to be set incorrectly.

  112947.   **

  112948.   ** The "rcauth==SQLITE_OK" terms is the

  112949.   ** IMPLEMENTATION-OF: R-17228-37124 If the action code is SQLITE_DELETE and

  112950.   ** the callback returns SQLITE_IGNORE then the DELETE operation proceeds but

  112951.   ** the truncate optimization is disabled and all rows are deleted

  112952.   ** individually.

  112953.   */

  112954.   if( rcauth==SQLITE_OK

  112955.    && pWhere==0

  112956.    && !bComplex

  112957.    && !IsVirtual(pTab)

  112958. #ifdef SQLITE_ENABLE_PREUPDATE_HOOK

  112959.    && db->xPreUpdateCallback==0

  112960. #endif

  112961.   ){

  112962.     assert( !isView );

  112963.     sqlite3TableLock(pParse, iDb, pTab->tnum, 1, pTab->zName);

  112964.     if( HasRowid(pTab) ){

  112965.       sqlite3VdbeAddOp4(v, OP_Clear, pTab->tnum, iDb, memCnt ? memCnt : -1,

  112966.                         pTab->zName, P4_STATIC);

  112967.     }

  112968.     for(pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext){

  112969.       assert( pIdx->pSchema==pTab->pSchema );

  112970.       sqlite3VdbeAddOp2(v, OP_Clear, pIdx->tnum, iDb);

  112971.     }

  112972.   }else

  112973. #endif /* SQLITE_OMIT_TRUNCATE_OPTIMIZATION */

  112974.   {

  112975.     u16 wcf = WHERE_ONEPASS_DESIRED|WHERE_DUPLICATES_OK|WHERE_SEEK_TABLE;

  112976.     if( sNC.ncFlags & NC_VarSelect ) bComplex = 1;

  112977.     wcf |= (bComplex ? 0 : WHERE_ONEPASS_MULTIROW);

  112978.     if( HasRowid(pTab) ){

  112979.       /* For a rowid table, initialize the RowSet to an empty set */

  112980.       pPk = 0;

  112981.       nPk = 1;

  112982.       iRowSet = ++pParse->nMem;

  112983.       sqlite3VdbeAddOp2(v, OP_Null, 0, iRowSet);

  112984.     }else{

  112985.       /* For a WITHOUT ROWID table, create an ephemeral table used to

  112986.       ** hold all primary keys for rows to be deleted. */

  112987.       pPk = sqlite3PrimaryKeyIndex(pTab);

  112988.       assert( pPk!=0 );

  112989.       nPk = pPk->nKeyCol;

  112990.       iPk = pParse->nMem+1;

  112991.       pParse->nMem += nPk;

  112992.       iEphCur = pParse->nTab++;

  112993.       addrEphOpen = sqlite3VdbeAddOp2(v, OP_OpenEphemeral, iEphCur, nPk);

  112994.       sqlite3VdbeSetP4KeyInfo(pParse, pPk);

  112995.     }

  112996.   

  112997.     /* Construct a query to find the rowid or primary key for every row

  112998.     ** to be deleted, based on the WHERE clause. Set variable eOnePass

  112999.     ** to indicate the strategy used to implement this delete:

  113000.     **

  113001.     **  ONEPASS_OFF:    Two-pass approach - use a FIFO for rowids/PK values.

  113002.     **  ONEPASS_SINGLE: One-pass approach - at most one row deleted.

  113003.     **  ONEPASS_MULTI:  One-pass approach - any number of rows may be deleted.

  113004.     */

  113005.     pWInfo = sqlite3WhereBegin(pParse, pTabList, pWhere, 0, 0, wcf, iTabCur+1);

  113006.     if( pWInfo==0 ) goto delete_from_cleanup;

  113007.     eOnePass = sqlite3WhereOkOnePass(pWInfo, aiCurOnePass);

  113008.     assert( IsVirtual(pTab)==0 || eOnePass!=ONEPASS_MULTI );

  113009.     assert( IsVirtual(pTab) || bComplex || eOnePass!=ONEPASS_OFF );

  113010.     if( eOnePass!=ONEPASS_SINGLE ) sqlite3MultiWrite(pParse);

  113011.   

  113012.     /* Keep track of the number of rows to be deleted */

  113013.     if( memCnt ){

  113014.       sqlite3VdbeAddOp2(v, OP_AddImm, memCnt, 1);

  113015.     }

  113016.   

  113017.     /* Extract the rowid or primary key for the current row */

  113018.     if( pPk ){

  113019.       for(i=0; i<nPk; i++){

  113020.         assert( pPk->aiColumn[i]>=0 );

  113021.         sqlite3ExprCodeGetColumnOfTable(v, pTab, iTabCur,

  113022.                                         pPk->aiColumn[i], iPk+i);

  113023.       }

  113024.       iKey = iPk;

  113025.     }else{

  113026.       iKey = ++pParse->nMem;

  113027.       sqlite3ExprCodeGetColumnOfTable(v, pTab, iTabCur, -1, iKey);

  113028.     }

  113029.   

  113030.     if( eOnePass!=ONEPASS_OFF ){

  113031.       /* For ONEPASS, no need to store the rowid/primary-key. There is only

  113032.       ** one, so just keep it in its register(s) and fall through to the

  113033.       ** delete code.  */

  113034.       nKey = nPk; /* OP_Found will use an unpacked key */

  113035.       aToOpen = sqlite3DbMallocRawNN(db, nIdx+2);

  113036.       if( aToOpen==0 ){

  113037.         sqlite3WhereEnd(pWInfo);

  113038.         goto delete_from_cleanup;

  113039.       }

  113040.       memset(aToOpen, 1, nIdx+1);

  113041.       aToOpen[nIdx+1] = 0;

  113042.       if( aiCurOnePass[0]>=0 ) aToOpen[aiCurOnePass[0]-iTabCur] = 0;

  113043.       if( aiCurOnePass[1]>=0 ) aToOpen[aiCurOnePass[1]-iTabCur] = 0;

  113044.       if( addrEphOpen ) sqlite3VdbeChangeToNoop(v, addrEphOpen);

  113045.     }else{

  113046.       if( pPk ){

  113047.         /* Add the PK key for this row to the temporary table */

  113048.         iKey = ++pParse->nMem;

  113049.         nKey = 0;   /* Zero tells OP_Found to use a composite key */

  113050.         sqlite3VdbeAddOp4(v, OP_MakeRecord, iPk, nPk, iKey,

  113051.             sqlite3IndexAffinityStr(pParse->db, pPk), nPk);

  113052.         sqlite3VdbeAddOp4Int(v, OP_IdxInsert, iEphCur, iKey, iPk, nPk);

  113053.       }else{

  113054.         /* Add the rowid of the row to be deleted to the RowSet */

  113055.         nKey = 1;  /* OP_DeferredSeek always uses a single rowid */

  113056.         sqlite3VdbeAddOp2(v, OP_RowSetAdd, iRowSet, iKey);

  113057.       }

  113058.     }

  113059.   

  113060.     /* If this DELETE cannot use the ONEPASS strategy, this is the 

  113061.     ** end of the WHERE loop */

  113062.     if( eOnePass!=ONEPASS_OFF ){

  113063.       addrBypass = sqlite3VdbeMakeLabel(pParse);

  113064.     }else{

  113065.       sqlite3WhereEnd(pWInfo);

  113066.     }

  113067.   

  113068.     /* Unless this is a view, open cursors for the table we are 

  113069.     ** deleting from and all its indices. If this is a view, then the

  113070.     ** only effect this statement has is to fire the INSTEAD OF 

  113071.     ** triggers.

  113072.     */

  113073.     if( !isView ){

  113074.       int iAddrOnce = 0;

  113075.       if( eOnePass==ONEPASS_MULTI ){

  113076.         iAddrOnce = sqlite3VdbeAddOp0(v, OP_Once); VdbeCoverage(v);

  113077.       }

  113078.       testcase( IsVirtual(pTab) );

  113079.       sqlite3OpenTableAndIndices(pParse, pTab, OP_OpenWrite, OPFLAG_FORDELETE,

  113080.                                  iTabCur, aToOpen, &iDataCur, &iIdxCur);

  113081.       assert( pPk || IsVirtual(pTab) || iDataCur==iTabCur );

  113082.       assert( pPk || IsVirtual(pTab) || iIdxCur==iDataCur+1 );

  113083.       if( eOnePass==ONEPASS_MULTI ) sqlite3VdbeJumpHere(v, iAddrOnce);

  113084.     }

  113085.   

  113086.     /* Set up a loop over the rowids/primary-keys that were found in the

  113087.     ** where-clause loop above.

  113088.     */

  113089.     if( eOnePass!=ONEPASS_OFF ){

  113090.       assert( nKey==nPk );  /* OP_Found will use an unpacked key */

  113091.       if( !IsVirtual(pTab) && aToOpen[iDataCur-iTabCur] ){

  113092.         assert( pPk!=0 || pTab->pSelect!=0 );

  113093.         sqlite3VdbeAddOp4Int(v, OP_NotFound, iDataCur, addrBypass, iKey, nKey);

  113094.         VdbeCoverage(v);

  113095.       }

  113096.     }else if( pPk ){

  113097.       addrLoop = sqlite3VdbeAddOp1(v, OP_Rewind, iEphCur); VdbeCoverage(v);

  113098.       if( IsVirtual(pTab) ){

  113099.         sqlite3VdbeAddOp3(v, OP_Column, iEphCur, 0, iKey);

  113100.       }else{

  113101.         sqlite3VdbeAddOp2(v, OP_RowData, iEphCur, iKey);

  113102.       }

  113103.       assert( nKey==0 );  /* OP_Found will use a composite key */

  113104.     }else{

  113105.       addrLoop = sqlite3VdbeAddOp3(v, OP_RowSetRead, iRowSet, 0, iKey);

  113106.       VdbeCoverage(v);

  113107.       assert( nKey==1 );

  113108.     }  

  113109.   

  113110.     /* Delete the row */

  113111. #ifndef SQLITE_OMIT_VIRTUALTABLE

  113112.     if( IsVirtual(pTab) ){

  113113.       const char *pVTab = (const char *)sqlite3GetVTable(db, pTab);

  113114.       sqlite3VtabMakeWritable(pParse, pTab);

  113115.       assert( eOnePass==ONEPASS_OFF || eOnePass==ONEPASS_SINGLE );

  113116.       sqlite3MayAbort(pParse);

  113117.       if( eOnePass==ONEPASS_SINGLE ){

  113118.         sqlite3VdbeAddOp1(v, OP_Close, iTabCur);

  113119.         if( sqlite3IsToplevel(pParse) ){

  113120.           pParse->isMultiWrite = 0;

  113121.         }

  113122.       }

  113123.       sqlite3VdbeAddOp4(v, OP_VUpdate, 0, 1, iKey, pVTab, P4_VTAB);

  113124.       sqlite3VdbeChangeP5(v, OE_Abort);

  113125.     }else

  113126. #endif

  113127.     {

  113128.       int count = (pParse->nested==0);    /* True to count changes */

  113129.       sqlite3GenerateRowDelete(pParse, pTab, pTrigger, iDataCur, iIdxCur,

  113130.           iKey, nKey, count, OE_Default, eOnePass, aiCurOnePass[1]);

  113131.     }

  113132.   

  113133.     /* End of the loop over all rowids/primary-keys. */

  113134.     if( eOnePass!=ONEPASS_OFF ){

  113135.       sqlite3VdbeResolveLabel(v, addrBypass);

  113136.       sqlite3WhereEnd(pWInfo);

  113137.     }else if( pPk ){

  113138.       sqlite3VdbeAddOp2(v, OP_Next, iEphCur, addrLoop+1); VdbeCoverage(v);

  113139.       sqlite3VdbeJumpHere(v, addrLoop);

  113140.     }else{

  113141.       sqlite3VdbeGoto(v, addrLoop);

  113142.       sqlite3VdbeJumpHere(v, addrLoop);

  113143.     }     

  113144.   } /* End non-truncate path */

  113145. 

  113146.   /* Update the sqlite_sequence table by storing the content of the

  113147.   ** maximum rowid counter values recorded while inserting into

  113148.   ** autoincrement tables.

  113149.   */

  113150.   if( pParse->nested==0 && pParse->pTriggerTab==0 ){

  113151.     sqlite3AutoincrementEnd(pParse);

  113152.   }

  113153. 

  113154.   /* Return the number of rows that were deleted. If this routine is 

  113155.   ** generating code because of a call to sqlite3NestedParse(), do not

  113156.   ** invoke the callback function.

  113157.   */

  113158.   if( memCnt ){

  113159.     sqlite3VdbeAddOp2(v, OP_ResultRow, memCnt, 1);

  113160.     sqlite3VdbeSetNumCols(v, 1);

  113161.     sqlite3VdbeSetColName(v, 0, COLNAME_NAME, "rows deleted", SQLITE_STATIC);

  113162.   }

  113163. 

  113164. delete_from_cleanup:

  113165.   sqlite3AuthContextPop(&sContext);

  113166.   sqlite3SrcListDelete(db, pTabList);

  113167.   sqlite3ExprDelete(db, pWhere);

  113168. #if defined(SQLITE_ENABLE_UPDATE_DELETE_LIMIT) 

  113169.   sqlite3ExprListDelete(db, pOrderBy);

  113170.   sqlite3ExprDelete(db, pLimit);

  113171. #endif

  113172.   sqlite3DbFree(db, aToOpen);

  113173.   return;

  113174. }

  113175. /* Make sure "isView" and other macros defined above are undefined. Otherwise

  113176. ** they may interfere with compilation of other functions in this file

  113177. ** (or in another file, if this file becomes part of the amalgamation).  */

  113178. #ifdef isView

  113179.  #undef isView

  113180. #endif

  113181. #ifdef pTrigger

  113182.  #undef pTrigger

  113183. #endif

  113184. 

  113185. /*

  113186. ** This routine generates VDBE code that causes a single row of a

  113187. ** single table to be deleted.  Both the original table entry and

  113188. ** all indices are removed.

  113189. **

  113190. ** Preconditions:

  113191. **

  113192. **   1.  iDataCur is an open cursor on the btree that is the canonical data

  113193. **       store for the table.  (This will be either the table itself,

  113194. **       in the case of a rowid table, or the PRIMARY KEY index in the case

  113195. **       of a WITHOUT ROWID table.)

  113196. **

  113197. **   2.  Read/write cursors for all indices of pTab must be open as

  113198. **       cursor number iIdxCur+i for the i-th index.

  113199. **

  113200. **   3.  The primary key for the row to be deleted must be stored in a

  113201. **       sequence of nPk memory cells starting at iPk.  If nPk==0 that means

  113202. **       that a search record formed from OP_MakeRecord is contained in the

  113203. **       single memory location iPk.

  113204. **

  113205. ** eMode:

  113206. **   Parameter eMode may be passed either ONEPASS_OFF (0), ONEPASS_SINGLE, or

  113207. **   ONEPASS_MULTI.  If eMode is not ONEPASS_OFF, then the cursor

  113208. **   iDataCur already points to the row to delete. If eMode is ONEPASS_OFF

  113209. **   then this function must seek iDataCur to the entry identified by iPk

  113210. **   and nPk before reading from it.

  113211. **

  113212. **   If eMode is ONEPASS_MULTI, then this call is being made as part

  113213. **   of a ONEPASS delete that affects multiple rows. In this case, if 

  113214. **   iIdxNoSeek is a valid cursor number (>=0) and is not the same as

  113215. **   iDataCur, then its position should be preserved following the delete

  113216. **   operation. Or, if iIdxNoSeek is not a valid cursor number, the

  113217. **   position of iDataCur should be preserved instead.

  113218. **

  113219. ** iIdxNoSeek:

  113220. **   If iIdxNoSeek is a valid cursor number (>=0) not equal to iDataCur,

  113221. **   then it identifies an index cursor (from within array of cursors

  113222. **   starting at iIdxCur) that already points to the index entry to be deleted.

  113223. **   Except, this optimization is disabled if there are BEFORE triggers since

  113224. **   the trigger body might have moved the cursor.

  113225. */

  113226. SQLITE_PRIVATE void sqlite3GenerateRowDelete(

  113227.   Parse *pParse,     /* Parsing context */

  113228.   Table *pTab,       /* Table containing the row to be deleted */

  113229.   Trigger *pTrigger, /* List of triggers to (potentially) fire */

  113230.   int iDataCur,      /* Cursor from which column data is extracted */

  113231.   int iIdxCur,       /* First index cursor */

  113232.   int iPk,           /* First memory cell containing the PRIMARY KEY */

  113233.   i16 nPk,           /* Number of PRIMARY KEY memory cells */

  113234.   u8 count,          /* If non-zero, increment the row change counter */

  113235.   u8 onconf,         /* Default ON CONFLICT policy for triggers */

  113236.   u8 eMode,          /* ONEPASS_OFF, _SINGLE, or _MULTI.  See above */

  113237.   int iIdxNoSeek     /* Cursor number of cursor that does not need seeking */

  113238. ){

  113239.   Vdbe *v = pParse->pVdbe;        /* Vdbe */

  113240.   int iOld = 0;                   /* First register in OLD.* array */

  113241.   int iLabel;                     /* Label resolved to end of generated code */

  113242.   u8 opSeek;                      /* Seek opcode */

  113243. 

  113244.   /* Vdbe is guaranteed to have been allocated by this stage. */

  113245.   assert( v );

  113246.   VdbeModuleComment((v, "BEGIN: GenRowDel(%d,%d,%d,%d)",

  113247.                          iDataCur, iIdxCur, iPk, (int)nPk));

  113248. 

  113249.   /* Seek cursor iCur to the row to delete. If this row no longer exists 

  113250.   ** (this can happen if a trigger program has already deleted it), do

  113251.   ** not attempt to delete it or fire any DELETE triggers.  */

  113252.   iLabel = sqlite3VdbeMakeLabel(pParse);

  113253.   opSeek = HasRowid(pTab) ? OP_NotExists : OP_NotFound;

  113254.   if( eMode==ONEPASS_OFF ){

  113255.     sqlite3VdbeAddOp4Int(v, opSeek, iDataCur, iLabel, iPk, nPk);

  113256.     VdbeCoverageIf(v, opSeek==OP_NotExists);

  113257.     VdbeCoverageIf(v, opSeek==OP_NotFound);

  113258.   }

  113259.  

  113260.   /* If there are any triggers to fire, allocate a range of registers to

  113261.   ** use for the old.* references in the triggers.  */

  113262.   if( sqlite3FkRequired(pParse, pTab, 0, 0) || pTrigger ){

  113263.     u32 mask;                     /* Mask of OLD.* columns in use */

  113264.     int iCol;                     /* Iterator used while populating OLD.* */

  113265.     int addrStart;                /* Start of BEFORE trigger programs */

  113266. 

  113267.     /* TODO: Could use temporary registers here. Also could attempt to

  113268.     ** avoid copying the contents of the rowid register.  */

  113269.     mask = sqlite3TriggerColmask(

  113270.         pParse, pTrigger, 0, 0, TRIGGER_BEFORE|TRIGGER_AFTER, pTab, onconf

  113271.     );

  113272.     mask |= sqlite3FkOldmask(pParse, pTab);

  113273.     iOld = pParse->nMem+1;

  113274.     pParse->nMem += (1 + pTab->nCol);

  113275. 

  113276.     /* Populate the OLD.* pseudo-table register array. These values will be 

  113277.     ** used by any BEFORE and AFTER triggers that exist.  */

  113278.     sqlite3VdbeAddOp2(v, OP_Copy, iPk, iOld);

  113279.     for(iCol=0; iCol<pTab->nCol; iCol++){

  113280.       testcase( mask!=0xffffffff && iCol==31 );

  113281.       testcase( mask!=0xffffffff && iCol==32 );

  113282.       if( mask==0xffffffff || (iCol<=31 && (mask & MASKBIT32(iCol))!=0) ){

  113283.         sqlite3ExprCodeGetColumnOfTable(v, pTab, iDataCur, iCol, iOld+iCol+1);

  113284.       }

  113285.     }

  113286. 

  113287.     /* Invoke BEFORE DELETE trigger programs. */

  113288.     addrStart = sqlite3VdbeCurrentAddr(v);

  113289.     sqlite3CodeRowTrigger(pParse, pTrigger, 

  113290.         TK_DELETE, 0, TRIGGER_BEFORE, pTab, iOld, onconf, iLabel

  113291.     );

  113292. 

  113293.     /* If any BEFORE triggers were coded, then seek the cursor to the 

  113294.     ** row to be deleted again. It may be that the BEFORE triggers moved

  113295.     ** the cursor or already deleted the row that the cursor was

  113296.     ** pointing to.

  113297.     **

  113298.     ** Also disable the iIdxNoSeek optimization since the BEFORE trigger

  113299.     ** may have moved that cursor.

  113300.     */

  113301.     if( addrStart<sqlite3VdbeCurrentAddr(v) ){

  113302.       sqlite3VdbeAddOp4Int(v, opSeek, iDataCur, iLabel, iPk, nPk);

  113303.       VdbeCoverageIf(v, opSeek==OP_NotExists);

  113304.       VdbeCoverageIf(v, opSeek==OP_NotFound);

  113305.       testcase( iIdxNoSeek>=0 );

  113306.       iIdxNoSeek = -1;

  113307.     }

  113308. 

  113309.     /* Do FK processing. This call checks that any FK constraints that

  113310.     ** refer to this table (i.e. constraints attached to other tables) 

  113311.     ** are not violated by deleting this row.  */

  113312.     sqlite3FkCheck(pParse, pTab, iOld, 0, 0, 0);

  113313.   }

  113314. 

  113315.   /* Delete the index and table entries. Skip this step if pTab is really

  113316.   ** a view (in which case the only effect of the DELETE statement is to

  113317.   ** fire the INSTEAD OF triggers).  

  113318.   **

  113319.   ** If variable 'count' is non-zero, then this OP_Delete instruction should

  113320.   ** invoke the update-hook. The pre-update-hook, on the other hand should

  113321.   ** be invoked unless table pTab is a system table. The difference is that

  113322.   ** the update-hook is not invoked for rows removed by REPLACE, but the 

  113323.   ** pre-update-hook is.

  113324.   */ 

  113325.   if( pTab->pSelect==0 ){

  113326.     u8 p5 = 0;

  113327.     sqlite3GenerateRowIndexDelete(pParse, pTab, iDataCur, iIdxCur,0,iIdxNoSeek);

  113328.     sqlite3VdbeAddOp2(v, OP_Delete, iDataCur, (count?OPFLAG_NCHANGE:0));

  113329.     if( pParse->nested==0 || 0==sqlite3_stricmp(pTab->zName, "sqlite_stat1") ){

  113330.       sqlite3VdbeAppendP4(v, (char*)pTab, P4_TABLE);

  113331.     }

  113332.     if( eMode!=ONEPASS_OFF ){

  113333.       sqlite3VdbeChangeP5(v, OPFLAG_AUXDELETE);

  113334.     }

  113335.     if( iIdxNoSeek>=0 && iIdxNoSeek!=iDataCur ){

  113336.       sqlite3VdbeAddOp1(v, OP_Delete, iIdxNoSeek);

  113337.     }

  113338.     if( eMode==ONEPASS_MULTI ) p5 |= OPFLAG_SAVEPOSITION;

  113339.     sqlite3VdbeChangeP5(v, p5);

  113340.   }

  113341. 

  113342.   /* Do any ON CASCADE, SET NULL or SET DEFAULT operations required to

  113343.   ** handle rows (possibly in other tables) that refer via a foreign key

  113344.   ** to the row just deleted. */ 

  113345.   sqlite3FkActions(pParse, pTab, 0, iOld, 0, 0);

  113346. 

  113347.   /* Invoke AFTER DELETE trigger programs. */

  113348.   sqlite3CodeRowTrigger(pParse, pTrigger, 

  113349.       TK_DELETE, 0, TRIGGER_AFTER, pTab, iOld, onconf, iLabel

  113350.   );

  113351. 

  113352.   /* Jump here if the row had already been deleted before any BEFORE

  113353.   ** trigger programs were invoked. Or if a trigger program throws a 

  113354.   ** RAISE(IGNORE) exception.  */

  113355.   sqlite3VdbeResolveLabel(v, iLabel);

  113356.   VdbeModuleComment((v, "END: GenRowDel()"));

  113357. }

  113358. 

  113359. /*

  113360. ** This routine generates VDBE code that causes the deletion of all

  113361. ** index entries associated with a single row of a single table, pTab

  113362. **

  113363. ** Preconditions:

  113364. **

  113365. **   1.  A read/write cursor "iDataCur" must be open on the canonical storage

  113366. **       btree for the table pTab.  (This will be either the table itself

  113367. **       for rowid tables or to the primary key index for WITHOUT ROWID

  113368. **       tables.)

  113369. **

  113370. **   2.  Read/write cursors for all indices of pTab must be open as

  113371. **       cursor number iIdxCur+i for the i-th index.  (The pTab->pIndex

  113372. **       index is the 0-th index.)

  113373. **

  113374. **   3.  The "iDataCur" cursor must be already be positioned on the row

  113375. **       that is to be deleted.

  113376. */

  113377. SQLITE_PRIVATE void sqlite3GenerateRowIndexDelete(

  113378.   Parse *pParse,     /* Parsing and code generating context */

  113379.   Table *pTab,       /* Table containing the row to be deleted */

  113380.   int iDataCur,      /* Cursor of table holding data. */

  113381.   int iIdxCur,       /* First index cursor */

  113382.   int *aRegIdx,      /* Only delete if aRegIdx!=0 && aRegIdx[i]>0 */

  113383.   int iIdxNoSeek     /* Do not delete from this cursor */

  113384. ){

  113385.   int i;             /* Index loop counter */

  113386.   int r1 = -1;       /* Register holding an index key */

  113387.   int iPartIdxLabel; /* Jump destination for skipping partial index entries */

  113388.   Index *pIdx;       /* Current index */

  113389.   Index *pPrior = 0; /* Prior index */

  113390.   Vdbe *v;           /* The prepared statement under construction */

  113391.   Index *pPk;        /* PRIMARY KEY index, or NULL for rowid tables */

  113392. 

  113393.   v = pParse->pVdbe;

  113394.   pPk = HasRowid(pTab) ? 0 : sqlite3PrimaryKeyIndex(pTab);

  113395.   for(i=0, pIdx=pTab->pIndex; pIdx; i++, pIdx=pIdx->pNext){

  113396.     assert( iIdxCur+i!=iDataCur || pPk==pIdx );

  113397.     if( aRegIdx!=0 && aRegIdx[i]==0 ) continue;

  113398.     if( pIdx==pPk ) continue;

  113399.     if( iIdxCur+i==iIdxNoSeek ) continue;

  113400.     VdbeModuleComment((v, "GenRowIdxDel for %s", pIdx->zName));

  113401.     r1 = sqlite3GenerateIndexKey(pParse, pIdx, iDataCur, 0, 1,

  113402.         &iPartIdxLabel, pPrior, r1);

  113403.     sqlite3VdbeAddOp3(v, OP_IdxDelete, iIdxCur+i, r1,

  113404.         pIdx->uniqNotNull ? pIdx->nKeyCol : pIdx->nColumn);

  113405.     sqlite3ResolvePartIdxLabel(pParse, iPartIdxLabel);

  113406.     pPrior = pIdx;

  113407.   }

  113408. }

  113409. 

  113410. /*

  113411. ** Generate code that will assemble an index key and stores it in register

  113412. ** regOut.  The key with be for index pIdx which is an index on pTab.

  113413. ** iCur is the index of a cursor open on the pTab table and pointing to

  113414. ** the entry that needs indexing.  If pTab is a WITHOUT ROWID table, then

  113415. ** iCur must be the cursor of the PRIMARY KEY index.

  113416. **

  113417. ** Return a register number which is the first in a block of

  113418. ** registers that holds the elements of the index key.  The

  113419. ** block of registers has already been deallocated by the time

  113420. ** this routine returns.

  113421. **

  113422. ** If *piPartIdxLabel is not NULL, fill it in with a label and jump

  113423. ** to that label if pIdx is a partial index that should be skipped.

  113424. ** The label should be resolved using sqlite3ResolvePartIdxLabel().

  113425. ** A partial index should be skipped if its WHERE clause evaluates

  113426. ** to false or null.  If pIdx is not a partial index, *piPartIdxLabel

  113427. ** will be set to zero which is an empty label that is ignored by

  113428. ** sqlite3ResolvePartIdxLabel().

  113429. **

  113430. ** The pPrior and regPrior parameters are used to implement a cache to

  113431. ** avoid unnecessary register loads.  If pPrior is not NULL, then it is

  113432. ** a pointer to a different index for which an index key has just been

  113433. ** computed into register regPrior.  If the current pIdx index is generating

  113434. ** its key into the same sequence of registers and if pPrior and pIdx share

  113435. ** a column in common, then the register corresponding to that column already

  113436. ** holds the correct value and the loading of that register is skipped.

  113437. ** This optimization is helpful when doing a DELETE or an INTEGRITY_CHECK 

  113438. ** on a table with multiple indices, and especially with the ROWID or

  113439. ** PRIMARY KEY columns of the index.

  113440. */

  113441. SQLITE_PRIVATE int sqlite3GenerateIndexKey(

  113442.   Parse *pParse,       /* Parsing context */

  113443.   Index *pIdx,         /* The index for which to generate a key */

  113444.   int iDataCur,        /* Cursor number from which to take column data */

  113445.   int regOut,          /* Put the new key into this register if not 0 */

  113446.   int prefixOnly,      /* Compute only a unique prefix of the key */

  113447.   int *piPartIdxLabel, /* OUT: Jump to this label to skip partial index */

  113448.   Index *pPrior,       /* Previously generated index key */

  113449.   int regPrior         /* Register holding previous generated key */

  113450. ){

  113451.   Vdbe *v = pParse->pVdbe;

  113452.   int j;

  113453.   int regBase;

  113454.   int nCol;

  113455. 

  113456.   if( piPartIdxLabel ){

  113457.     if( pIdx->pPartIdxWhere ){

  113458.       *piPartIdxLabel = sqlite3VdbeMakeLabel(pParse);

  113459.       pParse->iSelfTab = iDataCur + 1;

  113460.       sqlite3ExprIfFalseDup(pParse, pIdx->pPartIdxWhere, *piPartIdxLabel, 

  113461.                             SQLITE_JUMPIFNULL);

  113462.       pParse->iSelfTab = 0;

  113463.     }else{

  113464.       *piPartIdxLabel = 0;

  113465.     }

  113466.   }

  113467.   nCol = (prefixOnly && pIdx->uniqNotNull) ? pIdx->nKeyCol : pIdx->nColumn;

  113468.   regBase = sqlite3GetTempRange(pParse, nCol);

  113469.   if( pPrior && (regBase!=regPrior || pPrior->pPartIdxWhere) ) pPrior = 0;

  113470.   for(j=0; j<nCol; j++){

  113471.     if( pPrior

  113472.      && pPrior->aiColumn[j]==pIdx->aiColumn[j]

  113473.      && pPrior->aiColumn[j]!=XN_EXPR

  113474.     ){

  113475.       /* This column was already computed by the previous index */

  113476.       continue;

  113477.     }

  113478.     sqlite3ExprCodeLoadIndexColumn(pParse, pIdx, iDataCur, j, regBase+j);

  113479.     /* If the column affinity is REAL but the number is an integer, then it

  113480.     ** might be stored in the table as an integer (using a compact

  113481.     ** representation) then converted to REAL by an OP_RealAffinity opcode.

  113482.     ** But we are getting ready to store this value back into an index, where

  113483.     ** it should be converted by to INTEGER again.  So omit the OP_RealAffinity

  113484.     ** opcode if it is present */

  113485.     sqlite3VdbeDeletePriorOpcode(v, OP_RealAffinity);

  113486.   }

  113487.   if( regOut ){

  113488.     sqlite3VdbeAddOp3(v, OP_MakeRecord, regBase, nCol, regOut);

  113489.     if( pIdx->pTable->pSelect ){

  113490.       const char *zAff = sqlite3IndexAffinityStr(pParse->db, pIdx);

  113491.       sqlite3VdbeChangeP4(v, -1, zAff, P4_TRANSIENT);

  113492.     }

  113493.   }

  113494.   sqlite3ReleaseTempRange(pParse, regBase, nCol);

  113495.   return regBase;

  113496. }

  113497. 

  113498. /*

  113499. ** If a prior call to sqlite3GenerateIndexKey() generated a jump-over label

  113500. ** because it was a partial index, then this routine should be called to

  113501. ** resolve that label.

  113502. */

  113503. SQLITE_PRIVATE void sqlite3ResolvePartIdxLabel(Parse *pParse, int iLabel){

  113504.   if( iLabel ){

  113505.     sqlite3VdbeResolveLabel(pParse->pVdbe, iLabel);

  113506.   }

  113507. }

  113508. 

  113509. /************** End of delete.c **********************************************/

  113510. /************** Begin file func.c ********************************************/

  113511. /*

  113512. ** 2002 February 23

  113513. **

  113514. ** The author disclaims copyright to this source code.  In place of

  113515. ** a legal notice, here is a blessing:

  113516. **

  113517. **    May you do good and not evil.

  113518. **    May you find forgiveness for yourself and forgive others.

  113519. **    May you share freely, never taking more than you give.

  113520. **

  113521. *************************************************************************

  113522. ** This file contains the C-language implementations for many of the SQL

  113523. ** functions of SQLite.  (Some function, and in particular the date and

  113524. ** time functions, are implemented separately.)

  113525. */

  113526. /* #include "sqliteInt.h" */

  113527. /* #include <stdlib.h> */

  113528. /* #include <assert.h> */

  113529. /* #include <math.h> */

  113530. /* #include "vdbeInt.h" */

  113531. 

  113532. /*

  113533. ** Return the collating function associated with a function.

  113534. */

  113535. static CollSeq *sqlite3GetFuncCollSeq(sqlite3_context *context){

  113536.   VdbeOp *pOp;

  113537.   assert( context->pVdbe!=0 );

  113538.   pOp = &context->pVdbe->aOp[context->iOp-1];

  113539.   assert( pOp->opcode==OP_CollSeq );

  113540.   assert( pOp->p4type==P4_COLLSEQ );

  113541.   return pOp->p4.pColl;

  113542. }

  113543. 

  113544. /*

  113545. ** Indicate that the accumulator load should be skipped on this

  113546. ** iteration of the aggregate loop.

  113547. */

  113548. static void sqlite3SkipAccumulatorLoad(sqlite3_context *context){

  113549.   assert( context->isError<=0 );

  113550.   context->isError = -1;

  113551.   context->skipFlag = 1;

  113552. }

  113553. 

  113554. /*

  113555. ** Implementation of the non-aggregate min() and max() functions

  113556. */

  113557. static void minmaxFunc(

  113558.   sqlite3_context *context,

  113559.   int argc,

  113560.   sqlite3_value **argv

  113561. ){

  113562.   int i;

  113563.   int mask;    /* 0 for min() or 0xffffffff for max() */

  113564.   int iBest;

  113565.   CollSeq *pColl;

  113566. 

  113567.   assert( argc>1 );

  113568.   mask = sqlite3_user_data(context)==0 ? 0 : -1;

  113569.   pColl = sqlite3GetFuncCollSeq(context);

  113570.   assert( pColl );

  113571.   assert( mask==-1 || mask==0 );

  113572.   iBest = 0;

  113573.   if( sqlite3_value_type(argv[0])==SQLITE_NULL ) return;

  113574.   for(i=1; i<argc; i++){

  113575.     if( sqlite3_value_type(argv[i])==SQLITE_NULL ) return;

  113576.     if( (sqlite3MemCompare(argv[iBest], argv[i], pColl)^mask)>=0 ){

  113577.       testcase( mask==0 );

  113578.       iBest = i;

  113579.     }

  113580.   }

  113581.   sqlite3_result_value(context, argv[iBest]);

  113582. }

  113583. 

  113584. /*

  113585. ** Return the type of the argument.

  113586. */

  113587. static void typeofFunc(

  113588.   sqlite3_context *context,

  113589.   int NotUsed,

  113590.   sqlite3_value **argv

  113591. ){

  113592.   static const char *azType[] = { "integer", "real", "text", "blob", "null" };

  113593.   int i = sqlite3_value_type(argv[0]) - 1;

  113594.   UNUSED_PARAMETER(NotUsed);

  113595.   assert( i>=0 && i<ArraySize(azType) );

  113596.   assert( SQLITE_INTEGER==1 );

  113597.   assert( SQLITE_FLOAT==2 );

  113598.   assert( SQLITE_TEXT==3 );

  113599.   assert( SQLITE_BLOB==4 );

  113600.   assert( SQLITE_NULL==5 );

  113601.   /* EVIDENCE-OF: R-01470-60482 The sqlite3_value_type(V) interface returns

  113602.   ** the datatype code for the initial datatype of the sqlite3_value object

  113603.   ** V. The returned value is one of SQLITE_INTEGER, SQLITE_FLOAT,

  113604.   ** SQLITE_TEXT, SQLITE_BLOB, or SQLITE_NULL. */

  113605.   sqlite3_result_text(context, azType[i], -1, SQLITE_STATIC);

  113606. }

  113607. 

  113608. 

  113609. /*

  113610. ** Implementation of the length() function

  113611. */

  113612. static void lengthFunc(

  113613.   sqlite3_context *context,

  113614.   int argc,

  113615.   sqlite3_value **argv

  113616. ){

  113617.   assert( argc==1 );

  113618.   UNUSED_PARAMETER(argc);

  113619.   switch( sqlite3_value_type(argv[0]) ){

  113620.     case SQLITE_BLOB:

  113621.     case SQLITE_INTEGER:

  113622.     case SQLITE_FLOAT: {

  113623.       sqlite3_result_int(context, sqlite3_value_bytes(argv[0]));

  113624.       break;

  113625.     }

  113626.     case SQLITE_TEXT: {

  113627.       const unsigned char *z = sqlite3_value_text(argv[0]);

  113628.       const unsigned char *z0;

  113629.       unsigned char c;

  113630.       if( z==0 ) return;

  113631.       z0 = z;

  113632.       while( (c = *z)!=0 ){

  113633.         z++;

  113634.         if( c>=0xc0 ){

  113635.           while( (*z & 0xc0)==0x80 ){ z++; z0++; }

  113636.         }

  113637.       }

  113638.       sqlite3_result_int(context, (int)(z-z0));

  113639.       break;

  113640.     }

  113641.     default: {

  113642.       sqlite3_result_null(context);

  113643.       break;

  113644.     }

  113645.   }

  113646. }

  113647. 

  113648. /*

  113649. ** Implementation of the abs() function.

  113650. **

  113651. ** IMP: R-23979-26855 The abs(X) function returns the absolute value of

  113652. ** the numeric argument X. 

  113653. */

  113654. static void absFunc(sqlite3_context *context, int argc, sqlite3_value **argv){

  113655.   assert( argc==1 );

  113656.   UNUSED_PARAMETER(argc);

  113657.   switch( sqlite3_value_type(argv[0]) ){

  113658.     case SQLITE_INTEGER: {

  113659.       i64 iVal = sqlite3_value_int64(argv[0]);

  113660.       if( iVal<0 ){

  113661.         if( iVal==SMALLEST_INT64 ){

  113662.           /* IMP: R-31676-45509 If X is the integer -9223372036854775808

  113663.           ** then abs(X) throws an integer overflow error since there is no

  113664.           ** equivalent positive 64-bit two complement value. */

  113665.           sqlite3_result_error(context, "integer overflow", -1);

  113666.           return;

  113667.         }

  113668.         iVal = -iVal;

  113669.       } 

  113670.       sqlite3_result_int64(context, iVal);

  113671.       break;

  113672.     }

  113673.     case SQLITE_NULL: {

  113674.       /* IMP: R-37434-19929 Abs(X) returns NULL if X is NULL. */

  113675.       sqlite3_result_null(context);

  113676.       break;

  113677.     }

  113678.     default: {

  113679.       /* Because sqlite3_value_double() returns 0.0 if the argument is not

  113680.       ** something that can be converted into a number, we have:

  113681.       ** IMP: R-01992-00519 Abs(X) returns 0.0 if X is a string or blob

  113682.       ** that cannot be converted to a numeric value.

  113683.       */

  113684.       double rVal = sqlite3_value_double(argv[0]);

  113685.       if( rVal<0 ) rVal = -rVal;

  113686.       sqlite3_result_double(context, rVal);

  113687.       break;

  113688.     }

  113689.   }

  113690. }

  113691. 

  113692. /*

  113693. ** Implementation of the instr() function.

  113694. **

  113695. ** instr(haystack,needle) finds the first occurrence of needle

  113696. ** in haystack and returns the number of previous characters plus 1,

  113697. ** or 0 if needle does not occur within haystack.

  113698. **

  113699. ** If both haystack and needle are BLOBs, then the result is one more than

  113700. ** the number of bytes in haystack prior to the first occurrence of needle,

  113701. ** or 0 if needle never occurs in haystack.

  113702. */

  113703. static void instrFunc(

  113704.   sqlite3_context *context,

  113705.   int argc,

  113706.   sqlite3_value **argv

  113707. ){

  113708.   const unsigned char *zHaystack;

  113709.   const unsigned char *zNeedle;

  113710.   int nHaystack;

  113711.   int nNeedle;

  113712.   int typeHaystack, typeNeedle;

  113713.   int N = 1;

  113714.   int isText;

  113715.   unsigned char firstChar;

  113716. 

  113717.   UNUSED_PARAMETER(argc);

  113718.   typeHaystack = sqlite3_value_type(argv[0]);

  113719.   typeNeedle = sqlite3_value_type(argv[1]);

  113720.   if( typeHaystack==SQLITE_NULL || typeNeedle==SQLITE_NULL ) return;

  113721.   nHaystack = sqlite3_value_bytes(argv[0]);

  113722.   nNeedle = sqlite3_value_bytes(argv[1]);

  113723.   if( nNeedle>0 ){

  113724.     if( typeHaystack==SQLITE_BLOB && typeNeedle==SQLITE_BLOB ){

  113725.       zHaystack = sqlite3_value_blob(argv[0]);

  113726.       zNeedle = sqlite3_value_blob(argv[1]);

  113727.       isText = 0;

  113728.     }else{

  113729.       zHaystack = sqlite3_value_text(argv[0]);

  113730.       zNeedle = sqlite3_value_text(argv[1]);

  113731.       isText = 1;

  113732.     }

  113733.     if( zNeedle==0 || (nHaystack && zHaystack==0) ) return;

  113734.     firstChar = zNeedle[0];

  113735.     while( nNeedle<=nHaystack

  113736.        && (zHaystack[0]!=firstChar || memcmp(zHaystack, zNeedle, nNeedle)!=0)

  113737.     ){

  113738.       N++;

  113739.       do{

  113740.         nHaystack--;

  113741.         zHaystack++;

  113742.       }while( isText && (zHaystack[0]&0xc0)==0x80 );

  113743.     }

  113744.     if( nNeedle>nHaystack ) N = 0;

  113745.   }

  113746.   sqlite3_result_int(context, N);

  113747. }

  113748. 

  113749. /*

  113750. ** Implementation of the printf() function.

  113751. */

  113752. static void printfFunc(

  113753.   sqlite3_context *context,

  113754.   int argc,

  113755.   sqlite3_value **argv

  113756. ){

  113757.   PrintfArguments x;

  113758.   StrAccum str;

  113759.   const char *zFormat;

  113760.   int n;

  113761.   sqlite3 *db = sqlite3_context_db_handle(context);

  113762. 

  113763.   if( argc>=1 && (zFormat = (const char*)sqlite3_value_text(argv[0]))!=0 ){

  113764.     x.nArg = argc-1;

  113765.     x.nUsed = 0;

  113766.     x.apArg = argv+1;

  113767.     sqlite3StrAccumInit(&str, db, 0, 0, db->aLimit[SQLITE_LIMIT_LENGTH]);

  113768.     str.printfFlags = SQLITE_PRINTF_SQLFUNC;

  113769.     sqlite3_str_appendf(&str, zFormat, &x);

  113770.     n = str.nChar;

  113771.     sqlite3_result_text(context, sqlite3StrAccumFinish(&str), n,

  113772.                         SQLITE_DYNAMIC);

  113773.   }

  113774. }

  113775. 

  113776. /*

  113777. ** Implementation of the substr() function.

  113778. **

  113779. ** substr(x,p1,p2)  returns p2 characters of x[] beginning with p1.

  113780. ** p1 is 1-indexed.  So substr(x,1,1) returns the first character

  113781. ** of x.  If x is text, then we actually count UTF-8 characters.

  113782. ** If x is a blob, then we count bytes.

  113783. **

  113784. ** If p1 is negative, then we begin abs(p1) from the end of x[].

  113785. **

  113786. ** If p2 is negative, return the p2 characters preceding p1.

  113787. */

  113788. static void substrFunc(

  113789.   sqlite3_context *context,

  113790.   int argc,

  113791.   sqlite3_value **argv

  113792. ){

  113793.   const unsigned char *z;

  113794.   const unsigned char *z2;

  113795.   int len;

  113796.   int p0type;

  113797.   i64 p1, p2;

  113798.   int negP2 = 0;

  113799. 

  113800.   assert( argc==3 || argc==2 );

  113801.   if( sqlite3_value_type(argv[1])==SQLITE_NULL

  113802.    || (argc==3 && sqlite3_value_type(argv[2])==SQLITE_NULL)

  113803.   ){

  113804.     return;

  113805.   }

  113806.   p0type = sqlite3_value_type(argv[0]);

  113807.   p1 = sqlite3_value_int(argv[1]);

  113808.   if( p0type==SQLITE_BLOB ){

  113809.     len = sqlite3_value_bytes(argv[0]);

  113810.     z = sqlite3_value_blob(argv[0]);

  113811.     if( z==0 ) return;

  113812.     assert( len==sqlite3_value_bytes(argv[0]) );

  113813.   }else{

  113814.     z = sqlite3_value_text(argv[0]);

  113815.     if( z==0 ) return;

  113816.     len = 0;

  113817.     if( p1<0 ){

  113818.       for(z2=z; *z2; len++){

  113819.         SQLITE_SKIP_UTF8(z2);

  113820.       }

  113821.     }

  113822.   }

  113823. #ifdef SQLITE_SUBSTR_COMPATIBILITY

  113824.   /* If SUBSTR_COMPATIBILITY is defined then substr(X,0,N) work the same as

  113825.   ** as substr(X,1,N) - it returns the first N characters of X.  This

  113826.   ** is essentially a back-out of the bug-fix in check-in [5fc125d362df4b8]

  113827.   ** from 2009-02-02 for compatibility of applications that exploited the

  113828.   ** old buggy behavior. */

  113829.   if( p1==0 ) p1 = 1; /* <rdar://problem/6778339> */

  113830. #endif

  113831.   if( argc==3 ){

  113832.     p2 = sqlite3_value_int(argv[2]);

  113833.     if( p2<0 ){

  113834.       p2 = -p2;

  113835.       negP2 = 1;

  113836.     }

  113837.   }else{

  113838.     p2 = sqlite3_context_db_handle(context)->aLimit[SQLITE_LIMIT_LENGTH];

  113839.   }

  113840.   if( p1<0 ){

  113841.     p1 += len;

  113842.     if( p1<0 ){

  113843.       p2 += p1;

  113844.       if( p2<0 ) p2 = 0;

  113845.       p1 = 0;

  113846.     }

  113847.   }else if( p1>0 ){

  113848.     p1--;

  113849.   }else if( p2>0 ){

  113850.     p2--;

  113851.   }

  113852.   if( negP2 ){

  113853.     p1 -= p2;

  113854.     if( p1<0 ){

  113855.       p2 += p1;

  113856.       p1 = 0;

  113857.     }

  113858.   }

  113859.   assert( p1>=0 && p2>=0 );

  113860.   if( p0type!=SQLITE_BLOB ){

  113861.     while( *z && p1 ){

  113862.       SQLITE_SKIP_UTF8(z);

  113863.       p1--;

  113864.     }

  113865.     for(z2=z; *z2 && p2; p2--){

  113866.       SQLITE_SKIP_UTF8(z2);

  113867.     }

  113868.     sqlite3_result_text64(context, (char*)z, z2-z, SQLITE_TRANSIENT,

  113869.                           SQLITE_UTF8);

  113870.   }else{

  113871.     if( p1+p2>len ){

  113872.       p2 = len-p1;

  113873.       if( p2<0 ) p2 = 0;

  113874.     }

  113875.     sqlite3_result_blob64(context, (char*)&z[p1], (u64)p2, SQLITE_TRANSIENT);

  113876.   }

  113877. }

  113878. 

  113879. /*

  113880. ** Implementation of the round() function

  113881. */

  113882. #ifndef SQLITE_OMIT_FLOATING_POINT

  113883. static void roundFunc(sqlite3_context *context, int argc, sqlite3_value **argv){

  113884.   int n = 0;

  113885.   double r;

  113886.   char *zBuf;

  113887.   assert( argc==1 || argc==2 );

  113888.   if( argc==2 ){

  113889.     if( SQLITE_NULL==sqlite3_value_type(argv[1]) ) return;

  113890.     n = sqlite3_value_int(argv[1]);

  113891.     if( n>30 ) n = 30;

  113892.     if( n<0 ) n = 0;

  113893.   }

  113894.   if( sqlite3_value_type(argv[0])==SQLITE_NULL ) return;

  113895.   r = sqlite3_value_double(argv[0]);

  113896.   /* If Y==0 and X will fit in a 64-bit int,

  113897.   ** handle the rounding directly,

  113898.   ** otherwise use printf.

  113899.   */

  113900.   if( r<-4503599627370496.0 || r>+4503599627370496.0 ){

  113901.     /* The value has no fractional part so there is nothing to round */

  113902.   }else if( n==0 ){  

  113903.     r = (double)((sqlite_int64)(r+(r<0?-0.5:+0.5)));

  113904.   }else{

  113905.     zBuf = sqlite3_mprintf("%.*f",n,r);

  113906.     if( zBuf==0 ){

  113907.       sqlite3_result_error_nomem(context);

  113908.       return;

  113909.     }

  113910.     sqlite3AtoF(zBuf, &r, sqlite3Strlen30(zBuf), SQLITE_UTF8);

  113911.     sqlite3_free(zBuf);

  113912.   }

  113913.   sqlite3_result_double(context, r);

  113914. }

  113915. #endif

  113916. 

  113917. /*

  113918. ** Allocate nByte bytes of space using sqlite3Malloc(). If the

  113919. ** allocation fails, call sqlite3_result_error_nomem() to notify

  113920. ** the database handle that malloc() has failed and return NULL.

  113921. ** If nByte is larger than the maximum string or blob length, then

  113922. ** raise an SQLITE_TOOBIG exception and return NULL.

  113923. */

  113924. static void *contextMalloc(sqlite3_context *context, i64 nByte){

  113925.   char *z;

  113926.   sqlite3 *db = sqlite3_context_db_handle(context);

  113927.   assert( nByte>0 );

  113928.   testcase( nByte==db->aLimit[SQLITE_LIMIT_LENGTH] );

  113929.   testcase( nByte==db->aLimit[SQLITE_LIMIT_LENGTH]+1 );

  113930.   if( nByte>db->aLimit[SQLITE_LIMIT_LENGTH] ){

  113931.     sqlite3_result_error_toobig(context);

  113932.     z = 0;

  113933.   }else{

  113934.     z = sqlite3Malloc(nByte);

  113935.     if( !z ){

  113936.       sqlite3_result_error_nomem(context);

  113937.     }

  113938.   }

  113939.   return z;

  113940. }

  113941. 

  113942. /*

  113943. ** Implementation of the upper() and lower() SQL functions.

  113944. */

  113945. static void upperFunc(sqlite3_context *context, int argc, sqlite3_value **argv){

  113946.   char *z1;

  113947.   const char *z2;

  113948.   int i, n;

  113949.   UNUSED_PARAMETER(argc);

  113950.   z2 = (char*)sqlite3_value_text(argv[0]);

  113951.   n = sqlite3_value_bytes(argv[0]);

  113952.   /* Verify that the call to _bytes() does not invalidate the _text() pointer */

  113953.   assert( z2==(char*)sqlite3_value_text(argv[0]) );

  113954.   if( z2 ){

  113955.     z1 = contextMalloc(context, ((i64)n)+1);

  113956.     if( z1 ){

  113957.       for(i=0; i<n; i++){

  113958.         z1[i] = (char)sqlite3Toupper(z2[i]);

  113959.       }

  113960.       sqlite3_result_text(context, z1, n, sqlite3_free);

  113961.     }

  113962.   }

  113963. }

  113964. static void lowerFunc(sqlite3_context *context, int argc, sqlite3_value **argv){

  113965.   char *z1;

  113966.   const char *z2;

  113967.   int i, n;

  113968.   UNUSED_PARAMETER(argc);

  113969.   z2 = (char*)sqlite3_value_text(argv[0]);

  113970.   n = sqlite3_value_bytes(argv[0]);

  113971.   /* Verify that the call to _bytes() does not invalidate the _text() pointer */

  113972.   assert( z2==(char*)sqlite3_value_text(argv[0]) );

  113973.   if( z2 ){

  113974.     z1 = contextMalloc(context, ((i64)n)+1);

  113975.     if( z1 ){

  113976.       for(i=0; i<n; i++){

  113977.         z1[i] = sqlite3Tolower(z2[i]);

  113978.       }

  113979.       sqlite3_result_text(context, z1, n, sqlite3_free);

  113980.     }

  113981.   }

  113982. }

  113983. 

  113984. /*

  113985. ** Some functions like COALESCE() and IFNULL() and UNLIKELY() are implemented

  113986. ** as VDBE code so that unused argument values do not have to be computed.

  113987. ** However, we still need some kind of function implementation for this

  113988. ** routines in the function table.  The noopFunc macro provides this.

  113989. ** noopFunc will never be called so it doesn't matter what the implementation

  113990. ** is.  We might as well use the "version()" function as a substitute.

  113991. */

  113992. #define noopFunc versionFunc   /* Substitute function - never called */

  113993. 

  113994. /*

  113995. ** Implementation of random().  Return a random integer.  

  113996. */

  113997. static void randomFunc(

  113998.   sqlite3_context *context,

  113999.   int NotUsed,

  114000.   sqlite3_value **NotUsed2

  114001. ){

  114002.   sqlite_int64 r;

  114003.   UNUSED_PARAMETER2(NotUsed, NotUsed2);

  114004.   sqlite3_randomness(sizeof(r), &r);

  114005.   if( r<0 ){

  114006.     /* We need to prevent a random number of 0x8000000000000000 

  114007.     ** (or -9223372036854775808) since when you do abs() of that

  114008.     ** number of you get the same value back again.  To do this

  114009.     ** in a way that is testable, mask the sign bit off of negative

  114010.     ** values, resulting in a positive value.  Then take the 

  114011.     ** 2s complement of that positive value.  The end result can

  114012.     ** therefore be no less than -9223372036854775807.

  114013.     */

  114014.     r = -(r & LARGEST_INT64);

  114015.   }

  114016.   sqlite3_result_int64(context, r);

  114017. }

  114018. 

  114019. /*

  114020. ** Implementation of randomblob(N).  Return a random blob

  114021. ** that is N bytes long.

  114022. */

  114023. static void randomBlob(

  114024.   sqlite3_context *context,

  114025.   int argc,

  114026.   sqlite3_value **argv

  114027. ){

  114028.   sqlite3_int64 n;

  114029.   unsigned char *p;

  114030.   assert( argc==1 );

  114031.   UNUSED_PARAMETER(argc);

  114032.   n = sqlite3_value_int64(argv[0]);

  114033.   if( n<1 ){

  114034.     n = 1;

  114035.   }

  114036.   p = contextMalloc(context, n);

  114037.   if( p ){

  114038.     sqlite3_randomness(n, p);

  114039.     sqlite3_result_blob(context, (char*)p, n, sqlite3_free);

  114040.   }

  114041. }

  114042. 

  114043. /*

  114044. ** Implementation of the last_insert_rowid() SQL function.  The return

  114045. ** value is the same as the sqlite3_last_insert_rowid() API function.

  114046. */

  114047. static void last_insert_rowid(

  114048.   sqlite3_context *context, 

  114049.   int NotUsed, 

  114050.   sqlite3_value **NotUsed2

  114051. ){

  114052.   sqlite3 *db = sqlite3_context_db_handle(context);

  114053.   UNUSED_PARAMETER2(NotUsed, NotUsed2);

  114054.   /* IMP: R-51513-12026 The last_insert_rowid() SQL function is a

  114055.   ** wrapper around the sqlite3_last_insert_rowid() C/C++ interface

  114056.   ** function. */

  114057.   sqlite3_result_int64(context, sqlite3_last_insert_rowid(db));

  114058. }

  114059. 

  114060. /*

  114061. ** Implementation of the changes() SQL function.

  114062. **

  114063. ** IMP: R-62073-11209 The changes() SQL function is a wrapper

  114064. ** around the sqlite3_changes() C/C++ function and hence follows the same

  114065. ** rules for counting changes.

  114066. */

  114067. static void changes(

  114068.   sqlite3_context *context,

  114069.   int NotUsed,

  114070.   sqlite3_value **NotUsed2

  114071. ){

  114072.   sqlite3 *db = sqlite3_context_db_handle(context);

  114073.   UNUSED_PARAMETER2(NotUsed, NotUsed2);

  114074.   sqlite3_result_int(context, sqlite3_changes(db));

  114075. }

  114076. 

  114077. /*

  114078. ** Implementation of the total_changes() SQL function.  The return value is

  114079. ** the same as the sqlite3_total_changes() API function.

  114080. */

  114081. static void total_changes(

  114082.   sqlite3_context *context,

  114083.   int NotUsed,

  114084.   sqlite3_value **NotUsed2

  114085. ){

  114086.   sqlite3 *db = sqlite3_context_db_handle(context);

  114087.   UNUSED_PARAMETER2(NotUsed, NotUsed2);

  114088.   /* IMP: R-52756-41993 This function is a wrapper around the

  114089.   ** sqlite3_total_changes() C/C++ interface. */

  114090.   sqlite3_result_int(context, sqlite3_total_changes(db));

  114091. }

  114092. 

  114093. /*

  114094. ** A structure defining how to do GLOB-style comparisons.

  114095. */

  114096. struct compareInfo {

  114097.   u8 matchAll;          /* "*" or "%" */

  114098.   u8 matchOne;          /* "?" or "_" */

  114099.   u8 matchSet;          /* "[" or 0 */

  114100.   u8 noCase;            /* true to ignore case differences */

  114101. };

  114102. 

  114103. /*

  114104. ** For LIKE and GLOB matching on EBCDIC machines, assume that every

  114105. ** character is exactly one byte in size.  Also, provde the Utf8Read()

  114106. ** macro for fast reading of the next character in the common case where

  114107. ** the next character is ASCII.

  114108. */

  114109. #if defined(SQLITE_EBCDIC)

  114110. # define sqlite3Utf8Read(A)        (*((*A)++))

  114111. # define Utf8Read(A)               (*(A++))

  114112. #else

  114113. # define Utf8Read(A)               (A[0]<0x80?*(A++):sqlite3Utf8Read(&A))

  114114. #endif

  114115. 

  114116. static const struct compareInfo globInfo = { '*', '?', '[', 0 };

  114117. /* The correct SQL-92 behavior is for the LIKE operator to ignore

  114118. ** case.  Thus  'a' LIKE 'A' would be true. */

  114119. static const struct compareInfo likeInfoNorm = { '%', '_',   0, 1 };

  114120. /* If SQLITE_CASE_SENSITIVE_LIKE is defined, then the LIKE operator

  114121. ** is case sensitive causing 'a' LIKE 'A' to be false */

  114122. static const struct compareInfo likeInfoAlt = { '%', '_',   0, 0 };

  114123. 

  114124. /*

  114125. ** Possible error returns from patternMatch()

  114126. */

  114127. #define SQLITE_MATCH             0

  114128. #define SQLITE_NOMATCH           1

  114129. #define SQLITE_NOWILDCARDMATCH   2

  114130. 

  114131. /*

  114132. ** Compare two UTF-8 strings for equality where the first string is

  114133. ** a GLOB or LIKE expression.  Return values:

  114134. **

  114135. **    SQLITE_MATCH:            Match

  114136. **    SQLITE_NOMATCH:          No match

  114137. **    SQLITE_NOWILDCARDMATCH:  No match in spite of having * or % wildcards.

  114138. **

  114139. ** Globbing rules:

  114140. **

  114141. **      '*'       Matches any sequence of zero or more characters.

  114142. **

  114143. **      '?'       Matches exactly one character.

  114144. **

  114145. **     [...]      Matches one character from the enclosed list of

  114146. **                characters.

  114147. **

  114148. **     [^...]     Matches one character not in the enclosed list.

  114149. **

  114150. ** With the [...] and [^...] matching, a ']' character can be included

  114151. ** in the list by making it the first character after '[' or '^'.  A

  114152. ** range of characters can be specified using '-'.  Example:

  114153. ** "[a-z]" matches any single lower-case letter.  To match a '-', make

  114154. ** it the last character in the list.

  114155. **

  114156. ** Like matching rules:

  114157. ** 

  114158. **      '%'       Matches any sequence of zero or more characters

  114159. **

  114160. ***     '_'       Matches any one character

  114161. **

  114162. **      Ec        Where E is the "esc" character and c is any other

  114163. **                character, including '%', '_', and esc, match exactly c.

  114164. **

  114165. ** The comments within this routine usually assume glob matching.

  114166. **

  114167. ** This routine is usually quick, but can be N**2 in the worst case.

  114168. */

  114169. static int patternCompare(

  114170.   const u8 *zPattern,              /* The glob pattern */

  114171.   const u8 *zString,               /* The string to compare against the glob */

  114172.   const struct compareInfo *pInfo, /* Information about how to do the compare */

  114173.   u32 matchOther                   /* The escape char (LIKE) or '[' (GLOB) */

  114174. ){

  114175.   u32 c, c2;                       /* Next pattern and input string chars */

  114176.   u32 matchOne = pInfo->matchOne;  /* "?" or "_" */

  114177.   u32 matchAll = pInfo->matchAll;  /* "*" or "%" */

  114178.   u8 noCase = pInfo->noCase;       /* True if uppercase==lowercase */

  114179.   const u8 *zEscaped = 0;          /* One past the last escaped input char */

  114180.   

  114181.   while( (c = Utf8Read(zPattern))!=0 ){

  114182.     if( c==matchAll ){  /* Match "*" */

  114183.       /* Skip over multiple "*" characters in the pattern.  If there

  114184.       ** are also "?" characters, skip those as well, but consume a

  114185.       ** single character of the input string for each "?" skipped */

  114186.       while( (c=Utf8Read(zPattern)) == matchAll || c == matchOne ){

  114187.         if( c==matchOne && sqlite3Utf8Read(&zString)==0 ){

  114188.           return SQLITE_NOWILDCARDMATCH;

  114189.         }

  114190.       }

  114191.       if( c==0 ){

  114192.         return SQLITE_MATCH;   /* "*" at the end of the pattern matches */

  114193.       }else if( c==matchOther ){

  114194.         if( pInfo->matchSet==0 ){

  114195.           c = sqlite3Utf8Read(&zPattern);

  114196.           if( c==0 ) return SQLITE_NOWILDCARDMATCH;

  114197.         }else{

  114198.           /* "[...]" immediately follows the "*".  We have to do a slow

  114199.           ** recursive search in this case, but it is an unusual case. */

  114200.           assert( matchOther<0x80 );  /* '[' is a single-byte character */

  114201.           while( *zString ){

  114202.             int bMatch = patternCompare(&zPattern[-1],zString,pInfo,matchOther);

  114203.             if( bMatch!=SQLITE_NOMATCH ) return bMatch;

  114204.             SQLITE_SKIP_UTF8(zString);

  114205.           }

  114206.           return SQLITE_NOWILDCARDMATCH;

  114207.         }

  114208.       }

  114209. 

  114210.       /* At this point variable c contains the first character of the

  114211.       ** pattern string past the "*".  Search in the input string for the

  114212.       ** first matching character and recursively continue the match from

  114213.       ** that point.

  114214.       **

  114215.       ** For a case-insensitive search, set variable cx to be the same as

  114216.       ** c but in the other case and search the input string for either

  114217.       ** c or cx.

  114218.       */

  114219.       if( c<=0x80 ){

  114220.         char zStop[3];

  114221.         int bMatch;

  114222.         if( noCase ){

  114223.           zStop[0] = sqlite3Toupper(c);

  114224.           zStop[1] = sqlite3Tolower(c);

  114225.           zStop[2] = 0;

  114226.         }else{

  114227.           zStop[0] = c;

  114228.           zStop[1] = 0;

  114229.         }

  114230.         while(1){

  114231.           zString += strcspn((const char*)zString, zStop);

  114232.           if( zString[0]==0 ) break;

  114233.           zString++;

  114234.           bMatch = patternCompare(zPattern,zString,pInfo,matchOther);

  114235.           if( bMatch!=SQLITE_NOMATCH ) return bMatch;

  114236.         }

  114237.       }else{

  114238.         int bMatch;

  114239.         while( (c2 = Utf8Read(zString))!=0 ){

  114240.           if( c2!=c ) continue;

  114241.           bMatch = patternCompare(zPattern,zString,pInfo,matchOther);

  114242.           if( bMatch!=SQLITE_NOMATCH ) return bMatch;

  114243.         }

  114244.       }

  114245.       return SQLITE_NOWILDCARDMATCH;

  114246.     }

  114247.     if( c==matchOther ){

  114248.       if( pInfo->matchSet==0 ){

  114249.         c = sqlite3Utf8Read(&zPattern);

  114250.         if( c==0 ) return SQLITE_NOMATCH;

  114251.         zEscaped = zPattern;

  114252.       }else{

  114253.         u32 prior_c = 0;

  114254.         int seen = 0;

  114255.         int invert = 0;

  114256.         c = sqlite3Utf8Read(&zString);

  114257.         if( c==0 ) return SQLITE_NOMATCH;

  114258.         c2 = sqlite3Utf8Read(&zPattern);

  114259.         if( c2=='^' ){

  114260.           invert = 1;

  114261.           c2 = sqlite3Utf8Read(&zPattern);

  114262.         }

  114263.         if( c2==']' ){

  114264.           if( c==']' ) seen = 1;

  114265.           c2 = sqlite3Utf8Read(&zPattern);

  114266.         }

  114267.         while( c2 && c2!=']' ){

  114268.           if( c2=='-' && zPattern[0]!=']' && zPattern[0]!=0 && prior_c>0 ){

  114269.             c2 = sqlite3Utf8Read(&zPattern);

  114270.             if( c>=prior_c && c<=c2 ) seen = 1;

  114271.             prior_c = 0;

  114272.           }else{

  114273.             if( c==c2 ){

  114274.               seen = 1;

  114275.             }

  114276.             prior_c = c2;

  114277.           }

  114278.           c2 = sqlite3Utf8Read(&zPattern);

  114279.         }

  114280.         if( c2==0 || (seen ^ invert)==0 ){

  114281.           return SQLITE_NOMATCH;

  114282.         }

  114283.         continue;

  114284.       }

  114285.     }

  114286.     c2 = Utf8Read(zString);

  114287.     if( c==c2 ) continue;

  114288.     if( noCase  && sqlite3Tolower(c)==sqlite3Tolower(c2) && c<0x80 && c2<0x80 ){

  114289.       continue;

  114290.     }

  114291.     if( c==matchOne && zPattern!=zEscaped && c2!=0 ) continue;

  114292.     return SQLITE_NOMATCH;

  114293.   }

  114294.   return *zString==0 ? SQLITE_MATCH : SQLITE_NOMATCH;

  114295. }

  114296. 

  114297. /*

  114298. ** The sqlite3_strglob() interface.  Return 0 on a match (like strcmp()) and

  114299. ** non-zero if there is no match.

  114300. */

  114301. SQLITE_API int sqlite3_strglob(const char *zGlobPattern, const char *zString){

  114302.   return patternCompare((u8*)zGlobPattern, (u8*)zString, &globInfo, '[');

  114303. }

  114304. 

  114305. /*

  114306. ** The sqlite3_strlike() interface.  Return 0 on a match and non-zero for

  114307. ** a miss - like strcmp().

  114308. */

  114309. SQLITE_API int sqlite3_strlike(const char *zPattern, const char *zStr, unsigned int esc){

  114310.   return patternCompare((u8*)zPattern, (u8*)zStr, &likeInfoNorm, esc);

  114311. }

  114312. 

  114313. /*

  114314. ** Count the number of times that the LIKE operator (or GLOB which is

  114315. ** just a variation of LIKE) gets called.  This is used for testing

  114316. ** only.

  114317. */

  114318. #ifdef SQLITE_TEST

  114319. SQLITE_API int sqlite3_like_count = 0;

  114320. #endif

  114321. 

  114322. 

  114323. /*

  114324. ** Implementation of the like() SQL function.  This function implements

  114325. ** the build-in LIKE operator.  The first argument to the function is the

  114326. ** pattern and the second argument is the string.  So, the SQL statements:

  114327. **

  114328. **       A LIKE B

  114329. **

  114330. ** is implemented as like(B,A).

  114331. **

  114332. ** This same function (with a different compareInfo structure) computes

  114333. ** the GLOB operator.

  114334. */

  114335. static void likeFunc(

  114336.   sqlite3_context *context, 

  114337.   int argc, 

  114338.   sqlite3_value **argv

  114339. ){

  114340.   const unsigned char *zA, *zB;

  114341.   u32 escape;

  114342.   int nPat;

  114343.   sqlite3 *db = sqlite3_context_db_handle(context);

  114344.   struct compareInfo *pInfo = sqlite3_user_data(context);

  114345. 

  114346. #ifdef SQLITE_LIKE_DOESNT_MATCH_BLOBS

  114347.   if( sqlite3_value_type(argv[0])==SQLITE_BLOB

  114348.    || sqlite3_value_type(argv[1])==SQLITE_BLOB

  114349.   ){

  114350. #ifdef SQLITE_TEST

  114351.     sqlite3_like_count++;

  114352. #endif

  114353.     sqlite3_result_int(context, 0);

  114354.     return;

  114355.   }

  114356. #endif

  114357. 

  114358.   /* Limit the length of the LIKE or GLOB pattern to avoid problems

  114359.   ** of deep recursion and N*N behavior in patternCompare().

  114360.   */

  114361.   nPat = sqlite3_value_bytes(argv[0]);

  114362.   testcase( nPat==db->aLimit[SQLITE_LIMIT_LIKE_PATTERN_LENGTH] );

  114363.   testcase( nPat==db->aLimit[SQLITE_LIMIT_LIKE_PATTERN_LENGTH]+1 );

  114364.   if( nPat > db->aLimit[SQLITE_LIMIT_LIKE_PATTERN_LENGTH] ){

  114365.     sqlite3_result_error(context, "LIKE or GLOB pattern too complex", -1);

  114366.     return;

  114367.   }

  114368.   if( argc==3 ){

  114369.     /* The escape character string must consist of a single UTF-8 character.

  114370.     ** Otherwise, return an error.

  114371.     */

  114372.     const unsigned char *zEsc = sqlite3_value_text(argv[2]);

  114373.     if( zEsc==0 ) return;

  114374.     if( sqlite3Utf8CharLen((char*)zEsc, -1)!=1 ){

  114375.       sqlite3_result_error(context, 

  114376.           "ESCAPE expression must be a single character", -1);

  114377.       return;

  114378.     }

  114379.     escape = sqlite3Utf8Read(&zEsc);

  114380.   }else{

  114381.     escape = pInfo->matchSet;

  114382.   }

  114383.   zB = sqlite3_value_text(argv[0]);

  114384.   zA = sqlite3_value_text(argv[1]);

  114385.   if( zA && zB ){

  114386. #ifdef SQLITE_TEST

  114387.     sqlite3_like_count++;

  114388. #endif

  114389.     sqlite3_result_int(context,

  114390.                       patternCompare(zB, zA, pInfo, escape)==SQLITE_MATCH);

  114391.   }

  114392. }

  114393. 

  114394. /*

  114395. ** Implementation of the NULLIF(x,y) function.  The result is the first

  114396. ** argument if the arguments are different.  The result is NULL if the

  114397. ** arguments are equal to each other.

  114398. */

  114399. static void nullifFunc(

  114400.   sqlite3_context *context,

  114401.   int NotUsed,

  114402.   sqlite3_value **argv

  114403. ){

  114404.   CollSeq *pColl = sqlite3GetFuncCollSeq(context);

  114405.   UNUSED_PARAMETER(NotUsed);

  114406.   if( sqlite3MemCompare(argv[0], argv[1], pColl)!=0 ){

  114407.     sqlite3_result_value(context, argv[0]);

  114408.   }

  114409. }

  114410. 

  114411. /*

  114412. ** Implementation of the sqlite_version() function.  The result is the version

  114413. ** of the SQLite library that is running.

  114414. */

  114415. static void versionFunc(

  114416.   sqlite3_context *context,

  114417.   int NotUsed,

  114418.   sqlite3_value **NotUsed2

  114419. ){

  114420.   UNUSED_PARAMETER2(NotUsed, NotUsed2);

  114421.   /* IMP: R-48699-48617 This function is an SQL wrapper around the

  114422.   ** sqlite3_libversion() C-interface. */

  114423.   sqlite3_result_text(context, sqlite3_libversion(), -1, SQLITE_STATIC);

  114424. }

  114425. 

  114426. /*

  114427. ** Implementation of the sqlite_source_id() function. The result is a string

  114428. ** that identifies the particular version of the source code used to build

  114429. ** SQLite.

  114430. */

  114431. static void sourceidFunc(

  114432.   sqlite3_context *context,

  114433.   int NotUsed,

  114434.   sqlite3_value **NotUsed2

  114435. ){

  114436.   UNUSED_PARAMETER2(NotUsed, NotUsed2);

  114437.   /* IMP: R-24470-31136 This function is an SQL wrapper around the

  114438.   ** sqlite3_sourceid() C interface. */

  114439.   sqlite3_result_text(context, sqlite3_sourceid(), -1, SQLITE_STATIC);

  114440. }

  114441. 

  114442. /*

  114443. ** Implementation of the sqlite_log() function.  This is a wrapper around

  114444. ** sqlite3_log().  The return value is NULL.  The function exists purely for

  114445. ** its side-effects.

  114446. */

  114447. static void errlogFunc(

  114448.   sqlite3_context *context,

  114449.   int argc,

  114450.   sqlite3_value **argv

  114451. ){

  114452.   UNUSED_PARAMETER(argc);

  114453.   UNUSED_PARAMETER(context);

  114454.   sqlite3_log(sqlite3_value_int(argv[0]), "%s", sqlite3_value_text(argv[1]));

  114455. }

  114456. 

  114457. /*

  114458. ** Implementation of the sqlite_compileoption_used() function.

  114459. ** The result is an integer that identifies if the compiler option

  114460. ** was used to build SQLite.

  114461. */

  114462. #ifndef SQLITE_OMIT_COMPILEOPTION_DIAGS

  114463. static void compileoptionusedFunc(

  114464.   sqlite3_context *context,

  114465.   int argc,

  114466.   sqlite3_value **argv

  114467. ){

  114468.   const char *zOptName;

  114469.   assert( argc==1 );

  114470.   UNUSED_PARAMETER(argc);

  114471.   /* IMP: R-39564-36305 The sqlite_compileoption_used() SQL

  114472.   ** function is a wrapper around the sqlite3_compileoption_used() C/C++

  114473.   ** function.

  114474.   */

  114475.   if( (zOptName = (const char*)sqlite3_value_text(argv[0]))!=0 ){

  114476.     sqlite3_result_int(context, sqlite3_compileoption_used(zOptName));

  114477.   }

  114478. }

  114479. #endif /* SQLITE_OMIT_COMPILEOPTION_DIAGS */

  114480. 

  114481. /*

  114482. ** Implementation of the sqlite_compileoption_get() function. 

  114483. ** The result is a string that identifies the compiler options 

  114484. ** used to build SQLite.

  114485. */

  114486. #ifndef SQLITE_OMIT_COMPILEOPTION_DIAGS

  114487. static void compileoptiongetFunc(

  114488.   sqlite3_context *context,

  114489.   int argc,

  114490.   sqlite3_value **argv

  114491. ){

  114492.   int n;

  114493.   assert( argc==1 );

  114494.   UNUSED_PARAMETER(argc);

  114495.   /* IMP: R-04922-24076 The sqlite_compileoption_get() SQL function

  114496.   ** is a wrapper around the sqlite3_compileoption_get() C/C++ function.

  114497.   */

  114498.   n = sqlite3_value_int(argv[0]);

  114499.   sqlite3_result_text(context, sqlite3_compileoption_get(n), -1, SQLITE_STATIC);

  114500. }

  114501. #endif /* SQLITE_OMIT_COMPILEOPTION_DIAGS */

  114502. 

  114503. /* Array for converting from half-bytes (nybbles) into ASCII hex

  114504. ** digits. */

  114505. static const char hexdigits[] = {

  114506.   '0', '1', '2', '3', '4', '5', '6', '7',

  114507.   '8', '9', 'A', 'B', 'C', 'D', 'E', 'F' 

  114508. };

  114509. 

  114510. /*

  114511. ** Implementation of the QUOTE() function.  This function takes a single

  114512. ** argument.  If the argument is numeric, the return value is the same as

  114513. ** the argument.  If the argument is NULL, the return value is the string

  114514. ** "NULL".  Otherwise, the argument is enclosed in single quotes with

  114515. ** single-quote escapes.

  114516. */

  114517. static void quoteFunc(sqlite3_context *context, int argc, sqlite3_value **argv){

  114518.   assert( argc==1 );

  114519.   UNUSED_PARAMETER(argc);

  114520.   switch( sqlite3_value_type(argv[0]) ){

  114521.     case SQLITE_FLOAT: {

  114522.       double r1, r2;

  114523.       char zBuf[50];

  114524.       r1 = sqlite3_value_double(argv[0]);

  114525.       sqlite3_snprintf(sizeof(zBuf), zBuf, "%!.15g", r1);

  114526.       sqlite3AtoF(zBuf, &r2, 20, SQLITE_UTF8);

  114527.       if( r1!=r2 ){

  114528.         sqlite3_snprintf(sizeof(zBuf), zBuf, "%!.20e", r1);

  114529.       }

  114530.       sqlite3_result_text(context, zBuf, -1, SQLITE_TRANSIENT);

  114531.       break;

  114532.     }

  114533.     case SQLITE_INTEGER: {

  114534.       sqlite3_result_value(context, argv[0]);

  114535.       break;

  114536.     }

  114537.     case SQLITE_BLOB: {

  114538.       char *zText = 0;

  114539.       char const *zBlob = sqlite3_value_blob(argv[0]);

  114540.       int nBlob = sqlite3_value_bytes(argv[0]);

  114541.       assert( zBlob==sqlite3_value_blob(argv[0]) ); /* No encoding change */

  114542.       zText = (char *)contextMalloc(context, (2*(i64)nBlob)+4); 

  114543.       if( zText ){

  114544.         int i;

  114545.         for(i=0; i<nBlob; i++){

  114546.           zText[(i*2)+2] = hexdigits[(zBlob[i]>>4)&0x0F];

  114547.           zText[(i*2)+3] = hexdigits[(zBlob[i])&0x0F];

  114548.         }

  114549.         zText[(nBlob*2)+2] = '\'';

  114550.         zText[(nBlob*2)+3] = '\0';

  114551.         zText[0] = 'X';

  114552.         zText[1] = '\'';

  114553.         sqlite3_result_text(context, zText, -1, SQLITE_TRANSIENT);

  114554.         sqlite3_free(zText);

  114555.       }

  114556.       break;

  114557.     }

  114558.     case SQLITE_TEXT: {

  114559.       int i,j;

  114560.       u64 n;

  114561.       const unsigned char *zArg = sqlite3_value_text(argv[0]);

  114562.       char *z;

  114563. 

  114564.       if( zArg==0 ) return;

  114565.       for(i=0, n=0; zArg[i]; i++){ if( zArg[i]=='\'' ) n++; }

  114566.       z = contextMalloc(context, ((i64)i)+((i64)n)+3);

  114567.       if( z ){

  114568.         z[0] = '\'';

  114569.         for(i=0, j=1; zArg[i]; i++){

  114570.           z[j++] = zArg[i];

  114571.           if( zArg[i]=='\'' ){

  114572.             z[j++] = '\'';

  114573.           }

  114574.         }

  114575.         z[j++] = '\'';

  114576.         z[j] = 0;

  114577.         sqlite3_result_text(context, z, j, sqlite3_free);

  114578.       }

  114579.       break;

  114580.     }

  114581.     default: {

  114582.       assert( sqlite3_value_type(argv[0])==SQLITE_NULL );

  114583.       sqlite3_result_text(context, "NULL", 4, SQLITE_STATIC);

  114584.       break;

  114585.     }

  114586.   }

  114587. }

  114588. 

  114589. /*

  114590. ** The unicode() function.  Return the integer unicode code-point value

  114591. ** for the first character of the input string. 

  114592. */

  114593. static void unicodeFunc(

  114594.   sqlite3_context *context,

  114595.   int argc,

  114596.   sqlite3_value **argv

  114597. ){

  114598.   const unsigned char *z = sqlite3_value_text(argv[0]);

  114599.   (void)argc;

  114600.   if( z && z[0] ) sqlite3_result_int(context, sqlite3Utf8Read(&z));

  114601. }

  114602. 

  114603. /*

  114604. ** The char() function takes zero or more arguments, each of which is

  114605. ** an integer.  It constructs a string where each character of the string

  114606. ** is the unicode character for the corresponding integer argument.

  114607. */

  114608. static void charFunc(

  114609.   sqlite3_context *context,

  114610.   int argc,

  114611.   sqlite3_value **argv

  114612. ){

  114613.   unsigned char *z, *zOut;

  114614.   int i;

  114615.   zOut = z = sqlite3_malloc64( argc*4+1 );

  114616.   if( z==0 ){

  114617.     sqlite3_result_error_nomem(context);

  114618.     return;

  114619.   }

  114620.   for(i=0; i<argc; i++){

  114621.     sqlite3_int64 x;

  114622.     unsigned c;

  114623.     x = sqlite3_value_int64(argv[i]);

  114624.     if( x<0 || x>0x10ffff ) x = 0xfffd;

  114625.     c = (unsigned)(x & 0x1fffff);

  114626.     if( c<0x00080 ){

  114627.       *zOut++ = (u8)(c&0xFF);

  114628.     }else if( c<0x00800 ){

  114629.       *zOut++ = 0xC0 + (u8)((c>>6)&0x1F);

  114630.       *zOut++ = 0x80 + (u8)(c & 0x3F);

  114631.     }else if( c<0x10000 ){

  114632.       *zOut++ = 0xE0 + (u8)((c>>12)&0x0F);

  114633.       *zOut++ = 0x80 + (u8)((c>>6) & 0x3F);

  114634.       *zOut++ = 0x80 + (u8)(c & 0x3F);

  114635.     }else{

  114636.       *zOut++ = 0xF0 + (u8)((c>>18) & 0x07);

  114637.       *zOut++ = 0x80 + (u8)((c>>12) & 0x3F);

  114638.       *zOut++ = 0x80 + (u8)((c>>6) & 0x3F);

  114639.       *zOut++ = 0x80 + (u8)(c & 0x3F);

  114640.     }                                                    \

  114641.   }

  114642.   sqlite3_result_text64(context, (char*)z, zOut-z, sqlite3_free, SQLITE_UTF8);

  114643. }

  114644. 

  114645. /*

  114646. ** The hex() function.  Interpret the argument as a blob.  Return

  114647. ** a hexadecimal rendering as text.

  114648. */

  114649. static void hexFunc(

  114650.   sqlite3_context *context,

  114651.   int argc,

  114652.   sqlite3_value **argv

  114653. ){

  114654.   int i, n;

  114655.   const unsigned char *pBlob;

  114656.   char *zHex, *z;

  114657.   assert( argc==1 );

  114658.   UNUSED_PARAMETER(argc);

  114659.   pBlob = sqlite3_value_blob(argv[0]);

  114660.   n = sqlite3_value_bytes(argv[0]);

  114661.   assert( pBlob==sqlite3_value_blob(argv[0]) );  /* No encoding change */

  114662.   z = zHex = contextMalloc(context, ((i64)n)*2 + 1);

  114663.   if( zHex ){

  114664.     for(i=0; i<n; i++, pBlob++){

  114665.       unsigned char c = *pBlob;

  114666.       *(z++) = hexdigits[(c>>4)&0xf];

  114667.       *(z++) = hexdigits[c&0xf];

  114668.     }

  114669.     *z = 0;

  114670.     sqlite3_result_text(context, zHex, n*2, sqlite3_free);

  114671.   }

  114672. }

  114673. 

  114674. /*

  114675. ** The zeroblob(N) function returns a zero-filled blob of size N bytes.

  114676. */

  114677. static void zeroblobFunc(

  114678.   sqlite3_context *context,

  114679.   int argc,

  114680.   sqlite3_value **argv

  114681. ){

  114682.   i64 n;

  114683.   int rc;

  114684.   assert( argc==1 );

  114685.   UNUSED_PARAMETER(argc);

  114686.   n = sqlite3_value_int64(argv[0]);

  114687.   if( n<0 ) n = 0;

  114688.   rc = sqlite3_result_zeroblob64(context, n); /* IMP: R-00293-64994 */

  114689.   if( rc ){

  114690.     sqlite3_result_error_code(context, rc);

  114691.   }

  114692. }

  114693. 

  114694. /*

  114695. ** The replace() function.  Three arguments are all strings: call

  114696. ** them A, B, and C. The result is also a string which is derived

  114697. ** from A by replacing every occurrence of B with C.  The match

  114698. ** must be exact.  Collating sequences are not used.

  114699. */

  114700. static void replaceFunc(

  114701.   sqlite3_context *context,

  114702.   int argc,

  114703.   sqlite3_value **argv

  114704. ){

  114705.   const unsigned char *zStr;        /* The input string A */

  114706.   const unsigned char *zPattern;    /* The pattern string B */

  114707.   const unsigned char *zRep;        /* The replacement string C */

  114708.   unsigned char *zOut;              /* The output */

  114709.   int nStr;                /* Size of zStr */

  114710.   int nPattern;            /* Size of zPattern */

  114711.   int nRep;                /* Size of zRep */

  114712.   i64 nOut;                /* Maximum size of zOut */

  114713.   int loopLimit;           /* Last zStr[] that might match zPattern[] */

  114714.   int i, j;                /* Loop counters */

  114715.   unsigned cntExpand;      /* Number zOut expansions */

  114716.   sqlite3 *db = sqlite3_context_db_handle(context);

  114717. 

  114718.   assert( argc==3 );

  114719.   UNUSED_PARAMETER(argc);

  114720.   zStr = sqlite3_value_text(argv[0]);

  114721.   if( zStr==0 ) return;

  114722.   nStr = sqlite3_value_bytes(argv[0]);

  114723.   assert( zStr==sqlite3_value_text(argv[0]) );  /* No encoding change */

  114724.   zPattern = sqlite3_value_text(argv[1]);

  114725.   if( zPattern==0 ){

  114726.     assert( sqlite3_value_type(argv[1])==SQLITE_NULL

  114727.             || sqlite3_context_db_handle(context)->mallocFailed );

  114728.     return;

  114729.   }

  114730.   if( zPattern[0]==0 ){

  114731.     assert( sqlite3_value_type(argv[1])!=SQLITE_NULL );

  114732.     sqlite3_result_value(context, argv[0]);

  114733.     return;

  114734.   }

  114735.   nPattern = sqlite3_value_bytes(argv[1]);

  114736.   assert( zPattern==sqlite3_value_text(argv[1]) );  /* No encoding change */

  114737.   zRep = sqlite3_value_text(argv[2]);

  114738.   if( zRep==0 ) return;

  114739.   nRep = sqlite3_value_bytes(argv[2]);

  114740.   assert( zRep==sqlite3_value_text(argv[2]) );

  114741.   nOut = nStr + 1;

  114742.   assert( nOut<SQLITE_MAX_LENGTH );

  114743.   zOut = contextMalloc(context, (i64)nOut);

  114744.   if( zOut==0 ){

  114745.     return;

  114746.   }

  114747.   loopLimit = nStr - nPattern;  

  114748.   cntExpand = 0;

  114749.   for(i=j=0; i<=loopLimit; i++){

  114750.     if( zStr[i]!=zPattern[0] || memcmp(&zStr[i], zPattern, nPattern) ){

  114751.       zOut[j++] = zStr[i];

  114752.     }else{

  114753.       if( nRep>nPattern ){

  114754.         nOut += nRep - nPattern;

  114755.         testcase( nOut-1==db->aLimit[SQLITE_LIMIT_LENGTH] );

  114756.         testcase( nOut-2==db->aLimit[SQLITE_LIMIT_LENGTH] );

  114757.         if( nOut-1>db->aLimit[SQLITE_LIMIT_LENGTH] ){

  114758.           sqlite3_result_error_toobig(context);

  114759.           sqlite3_free(zOut);

  114760.           return;

  114761.         }

  114762.         cntExpand++;

  114763.         if( (cntExpand&(cntExpand-1))==0 ){

  114764.           /* Grow the size of the output buffer only on substitutions

  114765.           ** whose index is a power of two: 1, 2, 4, 8, 16, 32, ... */

  114766.           u8 *zOld;

  114767.           zOld = zOut;

  114768.           zOut = sqlite3_realloc64(zOut, (int)nOut + (nOut - nStr - 1));

  114769.           if( zOut==0 ){

  114770.             sqlite3_result_error_nomem(context);

  114771.             sqlite3_free(zOld);

  114772.             return;

  114773.           }

  114774.         }

  114775.       }

  114776.       memcpy(&zOut[j], zRep, nRep);

  114777.       j += nRep;

  114778.       i += nPattern-1;

  114779.     }

  114780.   }

  114781.   assert( j+nStr-i+1<=nOut );

  114782.   memcpy(&zOut[j], &zStr[i], nStr-i);

  114783.   j += nStr - i;

  114784.   assert( j<=nOut );

  114785.   zOut[j] = 0;

  114786.   sqlite3_result_text(context, (char*)zOut, j, sqlite3_free);

  114787. }

  114788. 

  114789. /*

  114790. ** Implementation of the TRIM(), LTRIM(), and RTRIM() functions.

  114791. ** The userdata is 0x1 for left trim, 0x2 for right trim, 0x3 for both.

  114792. */

  114793. static void trimFunc(

  114794.   sqlite3_context *context,

  114795.   int argc,

  114796.   sqlite3_value **argv

  114797. ){

  114798.   const unsigned char *zIn;         /* Input string */

  114799.   const unsigned char *zCharSet;    /* Set of characters to trim */

  114800.   int nIn;                          /* Number of bytes in input */

  114801.   int flags;                        /* 1: trimleft  2: trimright  3: trim */

  114802.   int i;                            /* Loop counter */

  114803.   unsigned char *aLen = 0;          /* Length of each character in zCharSet */

  114804.   unsigned char **azChar = 0;       /* Individual characters in zCharSet */

  114805.   int nChar;                        /* Number of characters in zCharSet */

  114806. 

  114807.   if( sqlite3_value_type(argv[0])==SQLITE_NULL ){

  114808.     return;

  114809.   }

  114810.   zIn = sqlite3_value_text(argv[0]);

  114811.   if( zIn==0 ) return;

  114812.   nIn = sqlite3_value_bytes(argv[0]);

  114813.   assert( zIn==sqlite3_value_text(argv[0]) );

  114814.   if( argc==1 ){

  114815.     static const unsigned char lenOne[] = { 1 };

  114816.     static unsigned char * const azOne[] = { (u8*)" " };

  114817.     nChar = 1;

  114818.     aLen = (u8*)lenOne;

  114819.     azChar = (unsigned char **)azOne;

  114820.     zCharSet = 0;

  114821.   }else if( (zCharSet = sqlite3_value_text(argv[1]))==0 ){

  114822.     return;

  114823.   }else{

  114824.     const unsigned char *z;

  114825.     for(z=zCharSet, nChar=0; *z; nChar++){

  114826.       SQLITE_SKIP_UTF8(z);

  114827.     }

  114828.     if( nChar>0 ){

  114829.       azChar = contextMalloc(context, ((i64)nChar)*(sizeof(char*)+1));

  114830.       if( azChar==0 ){

  114831.         return;

  114832.       }

  114833.       aLen = (unsigned char*)&azChar[nChar];

  114834.       for(z=zCharSet, nChar=0; *z; nChar++){

  114835.         azChar[nChar] = (unsigned char *)z;

  114836.         SQLITE_SKIP_UTF8(z);

  114837.         aLen[nChar] = (u8)(z - azChar[nChar]);

  114838.       }

  114839.     }

  114840.   }

  114841.   if( nChar>0 ){

  114842.     flags = SQLITE_PTR_TO_INT(sqlite3_user_data(context));

  114843.     if( flags & 1 ){

  114844.       while( nIn>0 ){

  114845.         int len = 0;

  114846.         for(i=0; i<nChar; i++){

  114847.           len = aLen[i];

  114848.           if( len<=nIn && memcmp(zIn, azChar[i], len)==0 ) break;

  114849.         }

  114850.         if( i>=nChar ) break;

  114851.         zIn += len;

  114852.         nIn -= len;

  114853.       }

  114854.     }

  114855.     if( flags & 2 ){

  114856.       while( nIn>0 ){

  114857.         int len = 0;

  114858.         for(i=0; i<nChar; i++){

  114859.           len = aLen[i];

  114860.           if( len<=nIn && memcmp(&zIn[nIn-len],azChar[i],len)==0 ) break;

  114861.         }

  114862.         if( i>=nChar ) break;

  114863.         nIn -= len;

  114864.       }

  114865.     }

  114866.     if( zCharSet ){

  114867.       sqlite3_free(azChar);

  114868.     }

  114869.   }

  114870.   sqlite3_result_text(context, (char*)zIn, nIn, SQLITE_TRANSIENT);

  114871. }

  114872. 

  114873. 

  114874. #ifdef SQLITE_ENABLE_UNKNOWN_SQL_FUNCTION

  114875. /*

  114876. ** The "unknown" function is automatically substituted in place of

  114877. ** any unrecognized function name when doing an EXPLAIN or EXPLAIN QUERY PLAN

  114878. ** when the SQLITE_ENABLE_UNKNOWN_FUNCTION compile-time option is used.

  114879. ** When the "sqlite3" command-line shell is built using this functionality,

  114880. ** that allows an EXPLAIN or EXPLAIN QUERY PLAN for complex queries

  114881. ** involving application-defined functions to be examined in a generic

  114882. ** sqlite3 shell.

  114883. */

  114884. static void unknownFunc(

  114885.   sqlite3_context *context,

  114886.   int argc,

  114887.   sqlite3_value **argv

  114888. ){

  114889.   /* no-op */

  114890. }

  114891. #endif /*SQLITE_ENABLE_UNKNOWN_SQL_FUNCTION*/

  114892. 

  114893. 

  114894. /* IMP: R-25361-16150 This function is omitted from SQLite by default. It

  114895. ** is only available if the SQLITE_SOUNDEX compile-time option is used

  114896. ** when SQLite is built.

  114897. */

  114898. #ifdef SQLITE_SOUNDEX

  114899. /*

  114900. ** Compute the soundex encoding of a word.

  114901. **

  114902. ** IMP: R-59782-00072 The soundex(X) function returns a string that is the

  114903. ** soundex encoding of the string X. 

  114904. */

  114905. static void soundexFunc(

  114906.   sqlite3_context *context,

  114907.   int argc,

  114908.   sqlite3_value **argv

  114909. ){

  114910.   char zResult[8];

  114911.   const u8 *zIn;

  114912.   int i, j;

  114913.   static const unsigned char iCode[] = {

  114914.     0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,

  114915.     0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,

  114916.     0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,

  114917.     0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,

  114918.     0, 0, 1, 2, 3, 0, 1, 2, 0, 0, 2, 2, 4, 5, 5, 0,

  114919.     1, 2, 6, 2, 3, 0, 1, 0, 2, 0, 2, 0, 0, 0, 0, 0,

  114920.     0, 0, 1, 2, 3, 0, 1, 2, 0, 0, 2, 2, 4, 5, 5, 0,

  114921.     1, 2, 6, 2, 3, 0, 1, 0, 2, 0, 2, 0, 0, 0, 0, 0,

  114922.   };

  114923.   assert( argc==1 );

  114924.   zIn = (u8*)sqlite3_value_text(argv[0]);

  114925.   if( zIn==0 ) zIn = (u8*)"";

  114926.   for(i=0; zIn[i] && !sqlite3Isalpha(zIn[i]); i++){}

  114927.   if( zIn[i] ){

  114928.     u8 prevcode = iCode[zIn[i]&0x7f];

  114929.     zResult[0] = sqlite3Toupper(zIn[i]);

  114930.     for(j=1; j<4 && zIn[i]; i++){

  114931.       int code = iCode[zIn[i]&0x7f];

  114932.       if( code>0 ){

  114933.         if( code!=prevcode ){

  114934.           prevcode = code;

  114935.           zResult[j++] = code + '0';

  114936.         }

  114937.       }else{

  114938.         prevcode = 0;

  114939.       }

  114940.     }

  114941.     while( j<4 ){

  114942.       zResult[j++] = '0';

  114943.     }

  114944.     zResult[j] = 0;

  114945.     sqlite3_result_text(context, zResult, 4, SQLITE_TRANSIENT);

  114946.   }else{

  114947.     /* IMP: R-64894-50321 The string "?000" is returned if the argument

  114948.     ** is NULL or contains no ASCII alphabetic characters. */

  114949.     sqlite3_result_text(context, "?000", 4, SQLITE_STATIC);

  114950.   }

  114951. }

  114952. #endif /* SQLITE_SOUNDEX */

  114953. 

  114954. #ifndef SQLITE_OMIT_LOAD_EXTENSION

  114955. /*

  114956. ** A function that loads a shared-library extension then returns NULL.

  114957. */

  114958. static void loadExt(sqlite3_context *context, int argc, sqlite3_value **argv){

  114959.   const char *zFile = (const char *)sqlite3_value_text(argv[0]);

  114960.   const char *zProc;

  114961.   sqlite3 *db = sqlite3_context_db_handle(context);

  114962.   char *zErrMsg = 0;

  114963. 

  114964.   /* Disallow the load_extension() SQL function unless the SQLITE_LoadExtFunc

  114965.   ** flag is set.  See the sqlite3_enable_load_extension() API.

  114966.   */

  114967.   if( (db->flags & SQLITE_LoadExtFunc)==0 ){

  114968.     sqlite3_result_error(context, "not authorized", -1);

  114969.     return;

  114970.   }

  114971. 

  114972.   if( argc==2 ){

  114973.     zProc = (const char *)sqlite3_value_text(argv[1]);

  114974.   }else{

  114975.     zProc = 0;

  114976.   }

  114977.   if( zFile && sqlite3_load_extension(db, zFile, zProc, &zErrMsg) ){

  114978.     sqlite3_result_error(context, zErrMsg, -1);

  114979.     sqlite3_free(zErrMsg);

  114980.   }

  114981. }

  114982. #endif

  114983. 

  114984. 

  114985. /*

  114986. ** An instance of the following structure holds the context of a

  114987. ** sum() or avg() aggregate computation.

  114988. */

  114989. typedef struct SumCtx SumCtx;

  114990. struct SumCtx {

  114991.   double rSum;      /* Floating point sum */

  114992.   i64 iSum;         /* Integer sum */   

  114993.   i64 cnt;          /* Number of elements summed */

  114994.   u8 overflow;      /* True if integer overflow seen */

  114995.   u8 approx;        /* True if non-integer value was input to the sum */

  114996. };

  114997. 

  114998. /*

  114999. ** Routines used to compute the sum, average, and total.

  115000. **

  115001. ** The SUM() function follows the (broken) SQL standard which means

  115002. ** that it returns NULL if it sums over no inputs.  TOTAL returns

  115003. ** 0.0 in that case.  In addition, TOTAL always returns a float where

  115004. ** SUM might return an integer if it never encounters a floating point

  115005. ** value.  TOTAL never fails, but SUM might through an exception if

  115006. ** it overflows an integer.

  115007. */

  115008. static void sumStep(sqlite3_context *context, int argc, sqlite3_value **argv){

  115009.   SumCtx *p;

  115010.   int type;

  115011.   assert( argc==1 );

  115012.   UNUSED_PARAMETER(argc);

  115013.   p = sqlite3_aggregate_context(context, sizeof(*p));

  115014.   type = sqlite3_value_numeric_type(argv[0]);

  115015.   if( p && type!=SQLITE_NULL ){

  115016.     p->cnt++;

  115017.     if( type==SQLITE_INTEGER ){

  115018.       i64 v = sqlite3_value_int64(argv[0]);

  115019.       p->rSum += v;

  115020.       if( (p->approx|p->overflow)==0 && sqlite3AddInt64(&p->iSum, v) ){

  115021.         p->approx = p->overflow = 1;

  115022.       }

  115023.     }else{

  115024.       p->rSum += sqlite3_value_double(argv[0]);

  115025.       p->approx = 1;

  115026.     }

  115027.   }

  115028. }

  115029. #ifndef SQLITE_OMIT_WINDOWFUNC

  115030. static void sumInverse(sqlite3_context *context, int argc, sqlite3_value**argv){

  115031.   SumCtx *p;

  115032.   int type;

  115033.   assert( argc==1 );

  115034.   UNUSED_PARAMETER(argc);

  115035.   p = sqlite3_aggregate_context(context, sizeof(*p));

  115036.   type = sqlite3_value_numeric_type(argv[0]);

  115037.   /* p is always non-NULL because sumStep() will have been called first

  115038.   ** to initialize it */

  115039.   if( ALWAYS(p) && type!=SQLITE_NULL ){

  115040.     assert( p->cnt>0 );

  115041.     p->cnt--;

  115042.     assert( type==SQLITE_INTEGER || p->approx );

  115043.     if( type==SQLITE_INTEGER && p->approx==0 ){

  115044.       i64 v = sqlite3_value_int64(argv[0]);

  115045.       p->rSum -= v;

  115046.       p->iSum -= v;

  115047.     }else{

  115048.       p->rSum -= sqlite3_value_double(argv[0]);

  115049.     }

  115050.   }

  115051. }

  115052. #else

  115053. # define sumInverse 0

  115054. #endif /* SQLITE_OMIT_WINDOWFUNC */

  115055. static void sumFinalize(sqlite3_context *context){

  115056.   SumCtx *p;

  115057.   p = sqlite3_aggregate_context(context, 0);

  115058.   if( p && p->cnt>0 ){

  115059.     if( p->overflow ){

  115060.       sqlite3_result_error(context,"integer overflow",-1);

  115061.     }else if( p->approx ){

  115062.       sqlite3_result_double(context, p->rSum);

  115063.     }else{

  115064.       sqlite3_result_int64(context, p->iSum);

  115065.     }

  115066.   }

  115067. }

  115068. static void avgFinalize(sqlite3_context *context){

  115069.   SumCtx *p;

  115070.   p = sqlite3_aggregate_context(context, 0);

  115071.   if( p && p->cnt>0 ){

  115072.     sqlite3_result_double(context, p->rSum/(double)p->cnt);

  115073.   }

  115074. }

  115075. static void totalFinalize(sqlite3_context *context){

  115076.   SumCtx *p;

  115077.   p = sqlite3_aggregate_context(context, 0);

  115078.   /* (double)0 In case of SQLITE_OMIT_FLOATING_POINT... */

  115079.   sqlite3_result_double(context, p ? p->rSum : (double)0);

  115080. }

  115081. 

  115082. /*

  115083. ** The following structure keeps track of state information for the

  115084. ** count() aggregate function.

  115085. */

  115086. typedef struct CountCtx CountCtx;

  115087. struct CountCtx {

  115088.   i64 n;

  115089. #ifdef SQLITE_DEBUG

  115090.   int bInverse;                   /* True if xInverse() ever called */

  115091. #endif

  115092. };

  115093. 

  115094. /*

  115095. ** Routines to implement the count() aggregate function.

  115096. */

  115097. static void countStep(sqlite3_context *context, int argc, sqlite3_value **argv){

  115098.   CountCtx *p;

  115099.   p = sqlite3_aggregate_context(context, sizeof(*p));

  115100.   if( (argc==0 || SQLITE_NULL!=sqlite3_value_type(argv[0])) && p ){

  115101.     p->n++;

  115102.   }

  115103. 

  115104. #ifndef SQLITE_OMIT_DEPRECATED

  115105.   /* The sqlite3_aggregate_count() function is deprecated.  But just to make

  115106.   ** sure it still operates correctly, verify that its count agrees with our 

  115107.   ** internal count when using count(*) and when the total count can be

  115108.   ** expressed as a 32-bit integer. */

  115109.   assert( argc==1 || p==0 || p->n>0x7fffffff || p->bInverse

  115110.           || p->n==sqlite3_aggregate_count(context) );

  115111. #endif

  115112. }   

  115113. static void countFinalize(sqlite3_context *context){

  115114.   CountCtx *p;

  115115.   p = sqlite3_aggregate_context(context, 0);

  115116.   sqlite3_result_int64(context, p ? p->n : 0);

  115117. }

  115118. #ifndef SQLITE_OMIT_WINDOWFUNC

  115119. static void countInverse(sqlite3_context *ctx, int argc, sqlite3_value **argv){

  115120.   CountCtx *p;

  115121.   p = sqlite3_aggregate_context(ctx, sizeof(*p));

  115122.   /* p is always non-NULL since countStep() will have been called first */

  115123.   if( (argc==0 || SQLITE_NULL!=sqlite3_value_type(argv[0])) && ALWAYS(p) ){

  115124.     p->n--;

  115125. #ifdef SQLITE_DEBUG

  115126.     p->bInverse = 1;

  115127. #endif

  115128.   }

  115129. }   

  115130. #else

  115131. # define countInverse 0

  115132. #endif /* SQLITE_OMIT_WINDOWFUNC */

  115133. 

  115134. /*

  115135. ** Routines to implement min() and max() aggregate functions.

  115136. */

  115137. static void minmaxStep(

  115138.   sqlite3_context *context, 

  115139.   int NotUsed, 

  115140.   sqlite3_value **argv

  115141. ){

  115142.   Mem *pArg  = (Mem *)argv[0];

  115143.   Mem *pBest;

  115144.   UNUSED_PARAMETER(NotUsed);

  115145. 

  115146.   pBest = (Mem *)sqlite3_aggregate_context(context, sizeof(*pBest));

  115147.   if( !pBest ) return;

  115148. 

  115149.   if( sqlite3_value_type(pArg)==SQLITE_NULL ){

  115150.     if( pBest->flags ) sqlite3SkipAccumulatorLoad(context);

  115151.   }else if( pBest->flags ){

  115152.     int max;

  115153.     int cmp;

  115154.     CollSeq *pColl = sqlite3GetFuncCollSeq(context);

  115155.     /* This step function is used for both the min() and max() aggregates,

  115156.     ** the only difference between the two being that the sense of the

  115157.     ** comparison is inverted. For the max() aggregate, the

  115158.     ** sqlite3_user_data() function returns (void *)-1. For min() it

  115159.     ** returns (void *)db, where db is the sqlite3* database pointer.

  115160.     ** Therefore the next statement sets variable 'max' to 1 for the max()

  115161.     ** aggregate, or 0 for min().

  115162.     */

  115163.     max = sqlite3_user_data(context)!=0;

  115164.     cmp = sqlite3MemCompare(pBest, pArg, pColl);

  115165.     if( (max && cmp<0) || (!max && cmp>0) ){

  115166.       sqlite3VdbeMemCopy(pBest, pArg);

  115167.     }else{

  115168.       sqlite3SkipAccumulatorLoad(context);

  115169.     }

  115170.   }else{

  115171.     pBest->db = sqlite3_context_db_handle(context);

  115172.     sqlite3VdbeMemCopy(pBest, pArg);

  115173.   }

  115174. }

  115175. static void minMaxValueFinalize(sqlite3_context *context, int bValue){

  115176.   sqlite3_value *pRes;

  115177.   pRes = (sqlite3_value *)sqlite3_aggregate_context(context, 0);

  115178.   if( pRes ){

  115179.     if( pRes->flags ){

  115180.       sqlite3_result_value(context, pRes);

  115181.     }

  115182.     if( bValue==0 ) sqlite3VdbeMemRelease(pRes);

  115183.   }

  115184. }

  115185. #ifndef SQLITE_OMIT_WINDOWFUNC

  115186. static void minMaxValue(sqlite3_context *context){

  115187.   minMaxValueFinalize(context, 1);

  115188. }

  115189. #else

  115190. # define minMaxValue 0

  115191. #endif /* SQLITE_OMIT_WINDOWFUNC */

  115192. static void minMaxFinalize(sqlite3_context *context){

  115193.   minMaxValueFinalize(context, 0);

  115194. }

  115195. 

  115196. /*

  115197. ** group_concat(EXPR, ?SEPARATOR?)

  115198. */

  115199. static void groupConcatStep(

  115200.   sqlite3_context *context,

  115201.   int argc,

  115202.   sqlite3_value **argv

  115203. ){

  115204.   const char *zVal;

  115205.   StrAccum *pAccum;

  115206.   const char *zSep;

  115207.   int nVal, nSep;

  115208.   assert( argc==1 || argc==2 );

  115209.   if( sqlite3_value_type(argv[0])==SQLITE_NULL ) return;

  115210.   pAccum = (StrAccum*)sqlite3_aggregate_context(context, sizeof(*pAccum));

  115211. 

  115212.   if( pAccum ){

  115213.     sqlite3 *db = sqlite3_context_db_handle(context);

  115214.     int firstTerm = pAccum->mxAlloc==0;

  115215.     pAccum->mxAlloc = db->aLimit[SQLITE_LIMIT_LENGTH];

  115216.     if( !firstTerm ){

  115217.       if( argc==2 ){

  115218.         zSep = (char*)sqlite3_value_text(argv[1]);

  115219.         nSep = sqlite3_value_bytes(argv[1]);

  115220.       }else{

  115221.         zSep = ",";

  115222.         nSep = 1;

  115223.       }

  115224.       if( zSep ) sqlite3_str_append(pAccum, zSep, nSep);

  115225.     }

  115226.     zVal = (char*)sqlite3_value_text(argv[0]);

  115227.     nVal = sqlite3_value_bytes(argv[0]);

  115228.     if( zVal ) sqlite3_str_append(pAccum, zVal, nVal);

  115229.   }

  115230. }

  115231. #ifndef SQLITE_OMIT_WINDOWFUNC

  115232. static void groupConcatInverse(

  115233.   sqlite3_context *context,

  115234.   int argc,

  115235.   sqlite3_value **argv

  115236. ){

  115237.   int n;

  115238.   StrAccum *pAccum;

  115239.   assert( argc==1 || argc==2 );

  115240.   if( sqlite3_value_type(argv[0])==SQLITE_NULL ) return;

  115241.   pAccum = (StrAccum*)sqlite3_aggregate_context(context, sizeof(*pAccum));

  115242.   /* pAccum is always non-NULL since groupConcatStep() will have always

  115243.   ** run frist to initialize it */

  115244.   if( ALWAYS(pAccum) ){

  115245.     n = sqlite3_value_bytes(argv[0]);

  115246.     if( argc==2 ){

  115247.       n += sqlite3_value_bytes(argv[1]);

  115248.     }else{

  115249.       n++;

  115250.     }

  115251.     if( n>=(int)pAccum->nChar ){

  115252.       pAccum->nChar = 0;

  115253.     }else{

  115254.       pAccum->nChar -= n;

  115255.       memmove(pAccum->zText, &pAccum->zText[n], pAccum->nChar);

  115256.     }

  115257.     if( pAccum->nChar==0 ) pAccum->mxAlloc = 0;

  115258.   }

  115259. }

  115260. #else

  115261. # define groupConcatInverse 0

  115262. #endif /* SQLITE_OMIT_WINDOWFUNC */

  115263. static void groupConcatFinalize(sqlite3_context *context){

  115264.   StrAccum *pAccum;

  115265.   pAccum = sqlite3_aggregate_context(context, 0);

  115266.   if( pAccum ){

  115267.     if( pAccum->accError==SQLITE_TOOBIG ){

  115268.       sqlite3_result_error_toobig(context);

  115269.     }else if( pAccum->accError==SQLITE_NOMEM ){

  115270.       sqlite3_result_error_nomem(context);

  115271.     }else{    

  115272.       sqlite3_result_text(context, sqlite3StrAccumFinish(pAccum), -1, 

  115273.                           sqlite3_free);

  115274.     }

  115275.   }

  115276. }

  115277. #ifndef SQLITE_OMIT_WINDOWFUNC

  115278. static void groupConcatValue(sqlite3_context *context){

  115279.   sqlite3_str *pAccum;

  115280.   pAccum = (sqlite3_str*)sqlite3_aggregate_context(context, 0);

  115281.   if( pAccum ){

  115282.     if( pAccum->accError==SQLITE_TOOBIG ){

  115283.       sqlite3_result_error_toobig(context);

  115284.     }else if( pAccum->accError==SQLITE_NOMEM ){

  115285.       sqlite3_result_error_nomem(context);

  115286.     }else{    

  115287.       const char *zText = sqlite3_str_value(pAccum);

  115288.       sqlite3_result_text(context, zText, -1, SQLITE_TRANSIENT);

  115289.     }

  115290.   }

  115291. }

  115292. #else

  115293. # define groupConcatValue 0

  115294. #endif /* SQLITE_OMIT_WINDOWFUNC */

  115295. 

  115296. /*

  115297. ** This routine does per-connection function registration.  Most

  115298. ** of the built-in functions above are part of the global function set.

  115299. ** This routine only deals with those that are not global.

  115300. */

  115301. SQLITE_PRIVATE void sqlite3RegisterPerConnectionBuiltinFunctions(sqlite3 *db){

  115302.   int rc = sqlite3_overload_function(db, "MATCH", 2);

  115303.   assert( rc==SQLITE_NOMEM || rc==SQLITE_OK );

  115304.   if( rc==SQLITE_NOMEM ){

  115305.     sqlite3OomFault(db);

  115306.   }

  115307. }

  115308. 

  115309. /*

  115310. ** Re-register the built-in LIKE functions.  The caseSensitive

  115311. ** parameter determines whether or not the LIKE operator is case

  115312. ** sensitive.

  115313. */

  115314. SQLITE_PRIVATE void sqlite3RegisterLikeFunctions(sqlite3 *db, int caseSensitive){

  115315.   struct compareInfo *pInfo;

  115316.   int flags;

  115317.   if( caseSensitive ){

  115318.     pInfo = (struct compareInfo*)&likeInfoAlt;

  115319.     flags = SQLITE_FUNC_LIKE | SQLITE_FUNC_CASE;

  115320.   }else{

  115321.     pInfo = (struct compareInfo*)&likeInfoNorm;

  115322.     flags = SQLITE_FUNC_LIKE;

  115323.   }

  115324.   sqlite3CreateFunc(db, "like", 2, SQLITE_UTF8, pInfo, likeFunc, 0, 0, 0, 0, 0);

  115325.   sqlite3CreateFunc(db, "like", 3, SQLITE_UTF8, pInfo, likeFunc, 0, 0, 0, 0, 0);

  115326.   sqlite3FindFunction(db, "like", 2, SQLITE_UTF8, 0)->funcFlags |= flags;

  115327.   sqlite3FindFunction(db, "like", 3, SQLITE_UTF8, 0)->funcFlags |= flags;

  115328. }

  115329. 

  115330. /*

  115331. ** pExpr points to an expression which implements a function.  If

  115332. ** it is appropriate to apply the LIKE optimization to that function

  115333. ** then set aWc[0] through aWc[2] to the wildcard characters and the

  115334. ** escape character and then return TRUE.  If the function is not a 

  115335. ** LIKE-style function then return FALSE.

  115336. **

  115337. ** The expression "a LIKE b ESCAPE c" is only considered a valid LIKE

  115338. ** operator if c is a string literal that is exactly one byte in length.

  115339. ** That one byte is stored in aWc[3].  aWc[3] is set to zero if there is

  115340. ** no ESCAPE clause.

  115341. **

  115342. ** *pIsNocase is set to true if uppercase and lowercase are equivalent for

  115343. ** the function (default for LIKE).  If the function makes the distinction

  115344. ** between uppercase and lowercase (as does GLOB) then *pIsNocase is set to

  115345. ** false.

  115346. */

  115347. SQLITE_PRIVATE int sqlite3IsLikeFunction(sqlite3 *db, Expr *pExpr, int *pIsNocase, char *aWc){

  115348.   FuncDef *pDef;

  115349.   int nExpr;

  115350.   if( pExpr->op!=TK_FUNCTION || !pExpr->x.pList ){

  115351.     return 0;

  115352.   }

  115353.   assert( !ExprHasProperty(pExpr, EP_xIsSelect) );

  115354.   nExpr = pExpr->x.pList->nExpr;

  115355.   pDef = sqlite3FindFunction(db, pExpr->u.zToken, nExpr, SQLITE_UTF8, 0);

  115356.   if( NEVER(pDef==0) || (pDef->funcFlags & SQLITE_FUNC_LIKE)==0 ){

  115357.     return 0;

  115358.   }

  115359.   if( nExpr<3 ){

  115360.     aWc[3] = 0;

  115361.   }else{

  115362.     Expr *pEscape = pExpr->x.pList->a[2].pExpr;

  115363.     char *zEscape;

  115364.     if( pEscape->op!=TK_STRING ) return 0;

  115365.     zEscape = pEscape->u.zToken;

  115366.     if( zEscape[0]==0 || zEscape[1]!=0 ) return 0;

  115367.     aWc[3] = zEscape[0];

  115368.   }

  115369. 

  115370.   /* The memcpy() statement assumes that the wildcard characters are

  115371.   ** the first three statements in the compareInfo structure.  The

  115372.   ** asserts() that follow verify that assumption

  115373.   */

  115374.   memcpy(aWc, pDef->pUserData, 3);

  115375.   assert( (char*)&likeInfoAlt == (char*)&likeInfoAlt.matchAll );

  115376.   assert( &((char*)&likeInfoAlt)[1] == (char*)&likeInfoAlt.matchOne );

  115377.   assert( &((char*)&likeInfoAlt)[2] == (char*)&likeInfoAlt.matchSet );

  115378.   *pIsNocase = (pDef->funcFlags & SQLITE_FUNC_CASE)==0;

  115379.   return 1;

  115380. }

  115381. 

  115382. /*

  115383. ** All of the FuncDef structures in the aBuiltinFunc[] array above

  115384. ** to the global function hash table.  This occurs at start-time (as

  115385. ** a consequence of calling sqlite3_initialize()).

  115386. **

  115387. ** After this routine runs

  115388. */

  115389. SQLITE_PRIVATE void sqlite3RegisterBuiltinFunctions(void){

  115390.   /*

  115391.   ** The following array holds FuncDef structures for all of the functions

  115392.   ** defined in this file.

  115393.   **

  115394.   ** The array cannot be constant since changes are made to the

  115395.   ** FuncDef.pHash elements at start-time.  The elements of this array

  115396.   ** are read-only after initialization is complete.

  115397.   **

  115398.   ** For peak efficiency, put the most frequently used function last.

  115399.   */

  115400.   static FuncDef aBuiltinFunc[] = {

  115401. #ifdef SQLITE_SOUNDEX

  115402.     FUNCTION(soundex,            1, 0, 0, soundexFunc      ),

  115403. #endif

  115404. #ifndef SQLITE_OMIT_LOAD_EXTENSION

  115405.     VFUNCTION(load_extension,    1, 0, 0, loadExt          ),

  115406.     VFUNCTION(load_extension,    2, 0, 0, loadExt          ),

  115407. #endif

  115408. #if SQLITE_USER_AUTHENTICATION

  115409.     FUNCTION(sqlite_crypt,       2, 0, 0, sqlite3CryptFunc ),

  115410. #endif

  115411. #ifndef SQLITE_OMIT_COMPILEOPTION_DIAGS

  115412.     DFUNCTION(sqlite_compileoption_used,1, 0, 0, compileoptionusedFunc  ),

  115413.     DFUNCTION(sqlite_compileoption_get, 1, 0, 0, compileoptiongetFunc  ),

  115414. #endif /* SQLITE_OMIT_COMPILEOPTION_DIAGS */

  115415.     FUNCTION2(unlikely,          1, 0, 0, noopFunc,  SQLITE_FUNC_UNLIKELY),

  115416.     FUNCTION2(likelihood,        2, 0, 0, noopFunc,  SQLITE_FUNC_UNLIKELY),

  115417.     FUNCTION2(likely,            1, 0, 0, noopFunc,  SQLITE_FUNC_UNLIKELY),

  115418. #ifdef SQLITE_DEBUG

  115419.     FUNCTION2(affinity,          1, 0, 0, noopFunc,  SQLITE_FUNC_AFFINITY),

  115420. #endif

  115421. #ifdef SQLITE_ENABLE_OFFSET_SQL_FUNC

  115422.     FUNCTION2(sqlite_offset,     1, 0, 0, noopFunc,  SQLITE_FUNC_OFFSET|

  115423.                                                      SQLITE_FUNC_TYPEOF),

  115424. #endif

  115425.     FUNCTION(ltrim,              1, 1, 0, trimFunc         ),

  115426.     FUNCTION(ltrim,              2, 1, 0, trimFunc         ),

  115427.     FUNCTION(rtrim,              1, 2, 0, trimFunc         ),

  115428.     FUNCTION(rtrim,              2, 2, 0, trimFunc         ),

  115429.     FUNCTION(trim,               1, 3, 0, trimFunc         ),

  115430.     FUNCTION(trim,               2, 3, 0, trimFunc         ),

  115431.     FUNCTION(min,               -1, 0, 1, minmaxFunc       ),

  115432.     FUNCTION(min,                0, 0, 1, 0                ),

  115433.     WAGGREGATE(min, 1, 0, 1, minmaxStep, minMaxFinalize, minMaxValue, 0,

  115434.                                           SQLITE_FUNC_MINMAX ),

  115435.     FUNCTION(max,               -1, 1, 1, minmaxFunc       ),

  115436.     FUNCTION(max,                0, 1, 1, 0                ),

  115437.     WAGGREGATE(max, 1, 1, 1, minmaxStep, minMaxFinalize, minMaxValue, 0,

  115438.                                           SQLITE_FUNC_MINMAX ),

  115439.     FUNCTION2(typeof,            1, 0, 0, typeofFunc,  SQLITE_FUNC_TYPEOF),

  115440.     FUNCTION2(length,            1, 0, 0, lengthFunc,  SQLITE_FUNC_LENGTH),

  115441.     FUNCTION(instr,              2, 0, 0, instrFunc        ),

  115442.     FUNCTION(printf,            -1, 0, 0, printfFunc       ),

  115443.     FUNCTION(unicode,            1, 0, 0, unicodeFunc      ),

  115444.     FUNCTION(char,              -1, 0, 0, charFunc         ),

  115445.     FUNCTION(abs,                1, 0, 0, absFunc          ),

  115446. #ifndef SQLITE_OMIT_FLOATING_POINT

  115447.     FUNCTION(round,              1, 0, 0, roundFunc        ),

  115448.     FUNCTION(round,              2, 0, 0, roundFunc        ),

  115449. #endif

  115450.     FUNCTION(upper,              1, 0, 0, upperFunc        ),

  115451.     FUNCTION(lower,              1, 0, 0, lowerFunc        ),

  115452.     FUNCTION(hex,                1, 0, 0, hexFunc          ),

  115453.     FUNCTION2(ifnull,            2, 0, 0, noopFunc,  SQLITE_FUNC_COALESCE),

  115454.     VFUNCTION(random,            0, 0, 0, randomFunc       ),

  115455.     VFUNCTION(randomblob,        1, 0, 0, randomBlob       ),

  115456.     FUNCTION(nullif,             2, 0, 1, nullifFunc       ),

  115457.     DFUNCTION(sqlite_version,    0, 0, 0, versionFunc      ),

  115458.     DFUNCTION(sqlite_source_id,  0, 0, 0, sourceidFunc     ),

  115459.     FUNCTION(sqlite_log,         2, 0, 0, errlogFunc       ),

  115460.     FUNCTION(quote,              1, 0, 0, quoteFunc        ),

  115461.     VFUNCTION(last_insert_rowid, 0, 0, 0, last_insert_rowid),

  115462.     VFUNCTION(changes,           0, 0, 0, changes          ),

  115463.     VFUNCTION(total_changes,     0, 0, 0, total_changes    ),

  115464.     FUNCTION(replace,            3, 0, 0, replaceFunc      ),

  115465.     FUNCTION(zeroblob,           1, 0, 0, zeroblobFunc     ),

  115466.     FUNCTION(substr,             2, 0, 0, substrFunc       ),

  115467.     FUNCTION(substr,             3, 0, 0, substrFunc       ),

  115468.     WAGGREGATE(sum,   1,0,0, sumStep, sumFinalize, sumFinalize, sumInverse, 0),

  115469.     WAGGREGATE(total, 1,0,0, sumStep,totalFinalize,totalFinalize,sumInverse, 0),

  115470.     WAGGREGATE(avg,   1,0,0, sumStep, avgFinalize, avgFinalize, sumInverse, 0),

  115471.     WAGGREGATE(count, 0,0,0, countStep, 

  115472.         countFinalize, countFinalize, countInverse, SQLITE_FUNC_COUNT  ),

  115473.     WAGGREGATE(count, 1,0,0, countStep, 

  115474.         countFinalize, countFinalize, countInverse, 0  ),

  115475.     WAGGREGATE(group_concat, 1, 0, 0, groupConcatStep, 

  115476.         groupConcatFinalize, groupConcatValue, groupConcatInverse, 0),

  115477.     WAGGREGATE(group_concat, 2, 0, 0, groupConcatStep, 

  115478.         groupConcatFinalize, groupConcatValue, groupConcatInverse, 0),

  115479.   

  115480.     LIKEFUNC(glob, 2, &globInfo, SQLITE_FUNC_LIKE|SQLITE_FUNC_CASE),

  115481. #ifdef SQLITE_CASE_SENSITIVE_LIKE

  115482.     LIKEFUNC(like, 2, &likeInfoAlt, SQLITE_FUNC_LIKE|SQLITE_FUNC_CASE),

  115483.     LIKEFUNC(like, 3, &likeInfoAlt, SQLITE_FUNC_LIKE|SQLITE_FUNC_CASE),

  115484. #else

  115485.     LIKEFUNC(like, 2, &likeInfoNorm, SQLITE_FUNC_LIKE),

  115486.     LIKEFUNC(like, 3, &likeInfoNorm, SQLITE_FUNC_LIKE),

  115487. #endif

  115488. #ifdef SQLITE_ENABLE_UNKNOWN_SQL_FUNCTION

  115489.     FUNCTION(unknown,           -1, 0, 0, unknownFunc      ),

  115490. #endif

  115491.     FUNCTION(coalesce,           1, 0, 0, 0                ),

  115492.     FUNCTION(coalesce,           0, 0, 0, 0                ),

  115493.     FUNCTION2(coalesce,         -1, 0, 0, noopFunc,  SQLITE_FUNC_COALESCE),

  115494.   };

  115495. #ifndef SQLITE_OMIT_ALTERTABLE

  115496.   sqlite3AlterFunctions();

  115497. #endif

  115498.   sqlite3WindowFunctions();

  115499. #if defined(SQLITE_ENABLE_STAT3) || defined(SQLITE_ENABLE_STAT4)

  115500.   sqlite3AnalyzeFunctions();

  115501. #endif

  115502.   sqlite3RegisterDateTimeFunctions();

  115503.   sqlite3InsertBuiltinFuncs(aBuiltinFunc, ArraySize(aBuiltinFunc));

  115504. 

  115505. #if 0  /* Enable to print out how the built-in functions are hashed */

  115506.   {

  115507.     int i;

  115508.     FuncDef *p;

  115509.     for(i=0; i<SQLITE_FUNC_HASH_SZ; i++){

  115510.       printf("FUNC-HASH %02d:", i);

  115511.       for(p=sqlite3BuiltinFunctions.a[i]; p; p=p->u.pHash){

  115512.         int n = sqlite3Strlen30(p->zName);

  115513.         int h = p->zName[0] + n;

  115514.         printf(" %s(%d)", p->zName, h);

  115515.       }

  115516.       printf("\n");

  115517.     }

  115518.   }

  115519. #endif

  115520. }

  115521. 

  115522. /************** End of func.c ************************************************/

  115523. /************** Begin file fkey.c ********************************************/

  115524. /*

  115525. **

  115526. ** The author disclaims copyright to this source code.  In place of

  115527. ** a legal notice, here is a blessing:

  115528. **

  115529. **    May you do good and not evil.

  115530. **    May you find forgiveness for yourself and forgive others.

  115531. **    May you share freely, never taking more than you give.

  115532. **

  115533. *************************************************************************

  115534. ** This file contains code used by the compiler to add foreign key

  115535. ** support to compiled SQL statements.

  115536. */

  115537. /* #include "sqliteInt.h" */

  115538. 

  115539. #ifndef SQLITE_OMIT_FOREIGN_KEY

  115540. #ifndef SQLITE_OMIT_TRIGGER

  115541. 

  115542. /*

  115543. ** Deferred and Immediate FKs

  115544. ** --------------------------

  115545. **

  115546. ** Foreign keys in SQLite come in two flavours: deferred and immediate.

  115547. ** If an immediate foreign key constraint is violated,

  115548. ** SQLITE_CONSTRAINT_FOREIGNKEY is returned and the current

  115549. ** statement transaction rolled back. If a 

  115550. ** deferred foreign key constraint is violated, no action is taken 

  115551. ** immediately. However if the application attempts to commit the 

  115552. ** transaction before fixing the constraint violation, the attempt fails.

  115553. **

  115554. ** Deferred constraints are implemented using a simple counter associated

  115555. ** with the database handle. The counter is set to zero each time a 

  115556. ** database transaction is opened. Each time a statement is executed 

  115557. ** that causes a foreign key violation, the counter is incremented. Each

  115558. ** time a statement is executed that removes an existing violation from

  115559. ** the database, the counter is decremented. When the transaction is

  115560. ** committed, the commit fails if the current value of the counter is

  115561. ** greater than zero. This scheme has two big drawbacks:

  115562. **

  115563. **   * When a commit fails due to a deferred foreign key constraint, 

  115564. **     there is no way to tell which foreign constraint is not satisfied,

  115565. **     or which row it is not satisfied for.

  115566. **

  115567. **   * If the database contains foreign key violations when the 

  115568. **     transaction is opened, this may cause the mechanism to malfunction.

  115569. **

  115570. ** Despite these problems, this approach is adopted as it seems simpler

  115571. ** than the alternatives.

  115572. **

  115573. ** INSERT operations:

  115574. **

  115575. **   I.1) For each FK for which the table is the child table, search

  115576. **        the parent table for a match. If none is found increment the

  115577. **        constraint counter.

  115578. **

  115579. **   I.2) For each FK for which the table is the parent table, 

  115580. **        search the child table for rows that correspond to the new

  115581. **        row in the parent table. Decrement the counter for each row

  115582. **        found (as the constraint is now satisfied).

  115583. **

  115584. ** DELETE operations:

  115585. **

  115586. **   D.1) For each FK for which the table is the child table, 

  115587. **        search the parent table for a row that corresponds to the 

  115588. **        deleted row in the child table. If such a row is not found, 

  115589. **        decrement the counter.

  115590. **

  115591. **   D.2) For each FK for which the table is the parent table, search 

  115592. **        the child table for rows that correspond to the deleted row 

  115593. **        in the parent table. For each found increment the counter.

  115594. **

  115595. ** UPDATE operations:

  115596. **

  115597. **   An UPDATE command requires that all 4 steps above are taken, but only

  115598. **   for FK constraints for which the affected columns are actually 

  115599. **   modified (values must be compared at runtime).

  115600. **

  115601. ** Note that I.1 and D.1 are very similar operations, as are I.2 and D.2.

  115602. ** This simplifies the implementation a bit.

  115603. **

  115604. ** For the purposes of immediate FK constraints, the OR REPLACE conflict

  115605. ** resolution is considered to delete rows before the new row is inserted.

  115606. ** If a delete caused by OR REPLACE violates an FK constraint, an exception

  115607. ** is thrown, even if the FK constraint would be satisfied after the new 

  115608. ** row is inserted.

  115609. **

  115610. ** Immediate constraints are usually handled similarly. The only difference 

  115611. ** is that the counter used is stored as part of each individual statement

  115612. ** object (struct Vdbe). If, after the statement has run, its immediate

  115613. ** constraint counter is greater than zero,

  115614. ** it returns SQLITE_CONSTRAINT_FOREIGNKEY

  115615. ** and the statement transaction is rolled back. An exception is an INSERT

  115616. ** statement that inserts a single row only (no triggers). In this case,

  115617. ** instead of using a counter, an exception is thrown immediately if the

  115618. ** INSERT violates a foreign key constraint. This is necessary as such

  115619. ** an INSERT does not open a statement transaction.

  115620. **

  115621. ** TODO: How should dropping a table be handled? How should renaming a 

  115622. ** table be handled?

  115623. **

  115624. **

  115625. ** Query API Notes

  115626. ** ---------------

  115627. **

  115628. ** Before coding an UPDATE or DELETE row operation, the code-generator

  115629. ** for those two operations needs to know whether or not the operation

  115630. ** requires any FK processing and, if so, which columns of the original

  115631. ** row are required by the FK processing VDBE code (i.e. if FKs were

  115632. ** implemented using triggers, which of the old.* columns would be 

  115633. ** accessed). No information is required by the code-generator before

  115634. ** coding an INSERT operation. The functions used by the UPDATE/DELETE

  115635. ** generation code to query for this information are:

  115636. **

  115637. **   sqlite3FkRequired() - Test to see if FK processing is required.

  115638. **   sqlite3FkOldmask()  - Query for the set of required old.* columns.

  115639. **

  115640. **

  115641. ** Externally accessible module functions

  115642. ** --------------------------------------

  115643. **

  115644. **   sqlite3FkCheck()    - Check for foreign key violations.

  115645. **   sqlite3FkActions()  - Code triggers for ON UPDATE/ON DELETE actions.

  115646. **   sqlite3FkDelete()   - Delete an FKey structure.

  115647. */

  115648. 

  115649. /*

  115650. ** VDBE Calling Convention

  115651. ** -----------------------

  115652. **

  115653. ** Example:

  115654. **

  115655. **   For the following INSERT statement:

  115656. **

  115657. **     CREATE TABLE t1(a, b INTEGER PRIMARY KEY, c);

  115658. **     INSERT INTO t1 VALUES(1, 2, 3.1);

  115659. **

  115660. **   Register (x):        2    (type integer)

  115661. **   Register (x+1):      1    (type integer)

  115662. **   Register (x+2):      NULL (type NULL)

  115663. **   Register (x+3):      3.1  (type real)

  115664. */

  115665. 

  115666. /*

  115667. ** A foreign key constraint requires that the key columns in the parent

  115668. ** table are collectively subject to a UNIQUE or PRIMARY KEY constraint.

  115669. ** Given that pParent is the parent table for foreign key constraint pFKey, 

  115670. ** search the schema for a unique index on the parent key columns. 

  115671. **

  115672. ** If successful, zero is returned. If the parent key is an INTEGER PRIMARY 

  115673. ** KEY column, then output variable *ppIdx is set to NULL. Otherwise, *ppIdx 

  115674. ** is set to point to the unique index. 

  115675. ** 

  115676. ** If the parent key consists of a single column (the foreign key constraint

  115677. ** is not a composite foreign key), output variable *paiCol is set to NULL.

  115678. ** Otherwise, it is set to point to an allocated array of size N, where

  115679. ** N is the number of columns in the parent key. The first element of the

  115680. ** array is the index of the child table column that is mapped by the FK

  115681. ** constraint to the parent table column stored in the left-most column

  115682. ** of index *ppIdx. The second element of the array is the index of the

  115683. ** child table column that corresponds to the second left-most column of

  115684. ** *ppIdx, and so on.

  115685. **

  115686. ** If the required index cannot be found, either because:

  115687. **

  115688. **   1) The named parent key columns do not exist, or

  115689. **

  115690. **   2) The named parent key columns do exist, but are not subject to a

  115691. **      UNIQUE or PRIMARY KEY constraint, or

  115692. **

  115693. **   3) No parent key columns were provided explicitly as part of the

  115694. **      foreign key definition, and the parent table does not have a

  115695. **      PRIMARY KEY, or

  115696. **

  115697. **   4) No parent key columns were provided explicitly as part of the

  115698. **      foreign key definition, and the PRIMARY KEY of the parent table 

  115699. **      consists of a different number of columns to the child key in 

  115700. **      the child table.

  115701. **

  115702. ** then non-zero is returned, and a "foreign key mismatch" error loaded

  115703. ** into pParse. If an OOM error occurs, non-zero is returned and the

  115704. ** pParse->db->mallocFailed flag is set.

  115705. */

  115706. SQLITE_PRIVATE int sqlite3FkLocateIndex(

  115707.   Parse *pParse,                  /* Parse context to store any error in */

  115708.   Table *pParent,                 /* Parent table of FK constraint pFKey */

  115709.   FKey *pFKey,                    /* Foreign key to find index for */

  115710.   Index **ppIdx,                  /* OUT: Unique index on parent table */

  115711.   int **paiCol                    /* OUT: Map of index columns in pFKey */

  115712. ){

  115713.   Index *pIdx = 0;                    /* Value to return via *ppIdx */

  115714.   int *aiCol = 0;                     /* Value to return via *paiCol */

  115715.   int nCol = pFKey->nCol;             /* Number of columns in parent key */

  115716.   char *zKey = pFKey->aCol[0].zCol;   /* Name of left-most parent key column */

  115717. 

  115718.   /* The caller is responsible for zeroing output parameters. */

  115719.   assert( ppIdx && *ppIdx==0 );

  115720.   assert( !paiCol || *paiCol==0 );

  115721.   assert( pParse );

  115722. 

  115723.   /* If this is a non-composite (single column) foreign key, check if it 

  115724.   ** maps to the INTEGER PRIMARY KEY of table pParent. If so, leave *ppIdx 

  115725.   ** and *paiCol set to zero and return early. 

  115726.   **

  115727.   ** Otherwise, for a composite foreign key (more than one column), allocate

  115728.   ** space for the aiCol array (returned via output parameter *paiCol).

  115729.   ** Non-composite foreign keys do not require the aiCol array.

  115730.   */

  115731.   if( nCol==1 ){

  115732.     /* The FK maps to the IPK if any of the following are true:

  115733.     **

  115734.     **   1) There is an INTEGER PRIMARY KEY column and the FK is implicitly 

  115735.     **      mapped to the primary key of table pParent, or

  115736.     **   2) The FK is explicitly mapped to a column declared as INTEGER

  115737.     **      PRIMARY KEY.

  115738.     */

  115739.     if( pParent->iPKey>=0 ){

  115740.       if( !zKey ) return 0;

  115741.       if( !sqlite3StrICmp(pParent->aCol[pParent->iPKey].zName, zKey) ) return 0;

  115742.     }

  115743.   }else if( paiCol ){

  115744.     assert( nCol>1 );

  115745.     aiCol = (int *)sqlite3DbMallocRawNN(pParse->db, nCol*sizeof(int));

  115746.     if( !aiCol ) return 1;

  115747.     *paiCol = aiCol;

  115748.   }

  115749. 

  115750.   for(pIdx=pParent->pIndex; pIdx; pIdx=pIdx->pNext){

  115751.     if( pIdx->nKeyCol==nCol && IsUniqueIndex(pIdx) && pIdx->pPartIdxWhere==0 ){ 

  115752.       /* pIdx is a UNIQUE index (or a PRIMARY KEY) and has the right number

  115753.       ** of columns. If each indexed column corresponds to a foreign key

  115754.       ** column of pFKey, then this index is a winner.  */

  115755. 

  115756.       if( zKey==0 ){

  115757.         /* If zKey is NULL, then this foreign key is implicitly mapped to 

  115758.         ** the PRIMARY KEY of table pParent. The PRIMARY KEY index may be 

  115759.         ** identified by the test.  */

  115760.         if( IsPrimaryKeyIndex(pIdx) ){

  115761.           if( aiCol ){

  115762.             int i;

  115763.             for(i=0; i<nCol; i++) aiCol[i] = pFKey->aCol[i].iFrom;

  115764.           }

  115765.           break;

  115766.         }

  115767.       }else{

  115768.         /* If zKey is non-NULL, then this foreign key was declared to

  115769.         ** map to an explicit list of columns in table pParent. Check if this

  115770.         ** index matches those columns. Also, check that the index uses

  115771.         ** the default collation sequences for each column. */

  115772.         int i, j;

  115773.         for(i=0; i<nCol; i++){

  115774.           i16 iCol = pIdx->aiColumn[i];     /* Index of column in parent tbl */

  115775.           const char *zDfltColl;            /* Def. collation for column */

  115776.           char *zIdxCol;                    /* Name of indexed column */

  115777. 

  115778.           if( iCol<0 ) break; /* No foreign keys against expression indexes */

  115779. 

  115780.           /* If the index uses a collation sequence that is different from

  115781.           ** the default collation sequence for the column, this index is

  115782.           ** unusable. Bail out early in this case.  */

  115783.           zDfltColl = pParent->aCol[iCol].zColl;

  115784.           if( !zDfltColl ) zDfltColl = sqlite3StrBINARY;

  115785.           if( sqlite3StrICmp(pIdx->azColl[i], zDfltColl) ) break;

  115786. 

  115787.           zIdxCol = pParent->aCol[iCol].zName;

  115788.           for(j=0; j<nCol; j++){

  115789.             if( sqlite3StrICmp(pFKey->aCol[j].zCol, zIdxCol)==0 ){

  115790.               if( aiCol ) aiCol[i] = pFKey->aCol[j].iFrom;

  115791.               break;

  115792.             }

  115793.           }

  115794.           if( j==nCol ) break;

  115795.         }

  115796.         if( i==nCol ) break;      /* pIdx is usable */

  115797.       }

  115798.     }

  115799.   }

  115800. 

  115801.   if( !pIdx ){

  115802.     if( !pParse->disableTriggers ){

  115803.       sqlite3ErrorMsg(pParse,

  115804.            "foreign key mismatch - \"%w\" referencing \"%w\"",

  115805.            pFKey->pFrom->zName, pFKey->zTo);

  115806.     }

  115807.     sqlite3DbFree(pParse->db, aiCol);

  115808.     return 1;

  115809.   }

  115810. 

  115811.   *ppIdx = pIdx;

  115812.   return 0;

  115813. }

  115814. 

  115815. /*

  115816. ** This function is called when a row is inserted into or deleted from the 

  115817. ** child table of foreign key constraint pFKey. If an SQL UPDATE is executed 

  115818. ** on the child table of pFKey, this function is invoked twice for each row

  115819. ** affected - once to "delete" the old row, and then again to "insert" the

  115820. ** new row.

  115821. **

  115822. ** Each time it is called, this function generates VDBE code to locate the

  115823. ** row in the parent table that corresponds to the row being inserted into 

  115824. ** or deleted from the child table. If the parent row can be found, no 

  115825. ** special action is taken. Otherwise, if the parent row can *not* be

  115826. ** found in the parent table:

  115827. **

  115828. **   Operation | FK type   | Action taken

  115829. **   --------------------------------------------------------------------------

  115830. **   INSERT      immediate   Increment the "immediate constraint counter".

  115831. **

  115832. **   DELETE      immediate   Decrement the "immediate constraint counter".

  115833. **

  115834. **   INSERT      deferred    Increment the "deferred constraint counter".

  115835. **

  115836. **   DELETE      deferred    Decrement the "deferred constraint counter".

  115837. **

  115838. ** These operations are identified in the comment at the top of this file 

  115839. ** (fkey.c) as "I.1" and "D.1".

  115840. */

  115841. static void fkLookupParent(

  115842.   Parse *pParse,        /* Parse context */

  115843.   int iDb,              /* Index of database housing pTab */

  115844.   Table *pTab,          /* Parent table of FK pFKey */

  115845.   Index *pIdx,          /* Unique index on parent key columns in pTab */

  115846.   FKey *pFKey,          /* Foreign key constraint */

  115847.   int *aiCol,           /* Map from parent key columns to child table columns */

  115848.   int regData,          /* Address of array containing child table row */

  115849.   int nIncr,            /* Increment constraint counter by this */

  115850.   int isIgnore          /* If true, pretend pTab contains all NULL values */

  115851. ){

  115852.   int i;                                    /* Iterator variable */

  115853.   Vdbe *v = sqlite3GetVdbe(pParse);         /* Vdbe to add code to */

  115854.   int iCur = pParse->nTab - 1;              /* Cursor number to use */

  115855.   int iOk = sqlite3VdbeMakeLabel(pParse);   /* jump here if parent key found */

  115856. 

  115857.   sqlite3VdbeVerifyAbortable(v,

  115858.     (!pFKey->isDeferred

  115859.       && !(pParse->db->flags & SQLITE_DeferFKs)

  115860.       && !pParse->pToplevel 

  115861.       && !pParse->isMultiWrite) ? OE_Abort : OE_Ignore);

  115862. 

  115863.   /* If nIncr is less than zero, then check at runtime if there are any

  115864.   ** outstanding constraints to resolve. If there are not, there is no need

  115865.   ** to check if deleting this row resolves any outstanding violations.

  115866.   **

  115867.   ** Check if any of the key columns in the child table row are NULL. If 

  115868.   ** any are, then the constraint is considered satisfied. No need to 

  115869.   ** search for a matching row in the parent table.  */

  115870.   if( nIncr<0 ){

  115871.     sqlite3VdbeAddOp2(v, OP_FkIfZero, pFKey->isDeferred, iOk);

  115872.     VdbeCoverage(v);

  115873.   }

  115874.   for(i=0; i<pFKey->nCol; i++){

  115875.     int iReg = aiCol[i] + regData + 1;

  115876.     sqlite3VdbeAddOp2(v, OP_IsNull, iReg, iOk); VdbeCoverage(v);

  115877.   }

  115878. 

  115879.   if( isIgnore==0 ){

  115880.     if( pIdx==0 ){

  115881.       /* If pIdx is NULL, then the parent key is the INTEGER PRIMARY KEY

  115882.       ** column of the parent table (table pTab).  */

  115883.       int iMustBeInt;               /* Address of MustBeInt instruction */

  115884.       int regTemp = sqlite3GetTempReg(pParse);

  115885.   

  115886.       /* Invoke MustBeInt to coerce the child key value to an integer (i.e. 

  115887.       ** apply the affinity of the parent key). If this fails, then there

  115888.       ** is no matching parent key. Before using MustBeInt, make a copy of

  115889.       ** the value. Otherwise, the value inserted into the child key column

  115890.       ** will have INTEGER affinity applied to it, which may not be correct.  */

  115891.       sqlite3VdbeAddOp2(v, OP_SCopy, aiCol[0]+1+regData, regTemp);

  115892.       iMustBeInt = sqlite3VdbeAddOp2(v, OP_MustBeInt, regTemp, 0);

  115893.       VdbeCoverage(v);

  115894.   

  115895.       /* If the parent table is the same as the child table, and we are about

  115896.       ** to increment the constraint-counter (i.e. this is an INSERT operation),

  115897.       ** then check if the row being inserted matches itself. If so, do not

  115898.       ** increment the constraint-counter.  */

  115899.       if( pTab==pFKey->pFrom && nIncr==1 ){

  115900.         sqlite3VdbeAddOp3(v, OP_Eq, regData, iOk, regTemp); VdbeCoverage(v);

  115901.         sqlite3VdbeChangeP5(v, SQLITE_NOTNULL);

  115902.       }

  115903.   

  115904.       sqlite3OpenTable(pParse, iCur, iDb, pTab, OP_OpenRead);

  115905.       sqlite3VdbeAddOp3(v, OP_NotExists, iCur, 0, regTemp); VdbeCoverage(v);

  115906.       sqlite3VdbeGoto(v, iOk);

  115907.       sqlite3VdbeJumpHere(v, sqlite3VdbeCurrentAddr(v)-2);

  115908.       sqlite3VdbeJumpHere(v, iMustBeInt);

  115909.       sqlite3ReleaseTempReg(pParse, regTemp);

  115910.     }else{

  115911.       int nCol = pFKey->nCol;

  115912.       int regTemp = sqlite3GetTempRange(pParse, nCol);

  115913.       int regRec = sqlite3GetTempReg(pParse);

  115914.   

  115915.       sqlite3VdbeAddOp3(v, OP_OpenRead, iCur, pIdx->tnum, iDb);

  115916.       sqlite3VdbeSetP4KeyInfo(pParse, pIdx);

  115917.       for(i=0; i<nCol; i++){

  115918.         sqlite3VdbeAddOp2(v, OP_Copy, aiCol[i]+1+regData, regTemp+i);

  115919.       }

  115920.   

  115921.       /* If the parent table is the same as the child table, and we are about

  115922.       ** to increment the constraint-counter (i.e. this is an INSERT operation),

  115923.       ** then check if the row being inserted matches itself. If so, do not

  115924.       ** increment the constraint-counter. 

  115925.       **

  115926.       ** If any of the parent-key values are NULL, then the row cannot match 

  115927.       ** itself. So set JUMPIFNULL to make sure we do the OP_Found if any

  115928.       ** of the parent-key values are NULL (at this point it is known that

  115929.       ** none of the child key values are).

  115930.       */

  115931.       if( pTab==pFKey->pFrom && nIncr==1 ){

  115932.         int iJump = sqlite3VdbeCurrentAddr(v) + nCol + 1;

  115933.         for(i=0; i<nCol; i++){

  115934.           int iChild = aiCol[i]+1+regData;

  115935.           int iParent = pIdx->aiColumn[i]+1+regData;

  115936.           assert( pIdx->aiColumn[i]>=0 );

  115937.           assert( aiCol[i]!=pTab->iPKey );

  115938.           if( pIdx->aiColumn[i]==pTab->iPKey ){

  115939.             /* The parent key is a composite key that includes the IPK column */

  115940.             iParent = regData;

  115941.           }

  115942.           sqlite3VdbeAddOp3(v, OP_Ne, iChild, iJump, iParent); VdbeCoverage(v);

  115943.           sqlite3VdbeChangeP5(v, SQLITE_JUMPIFNULL);

  115944.         }

  115945.         sqlite3VdbeGoto(v, iOk);

  115946.       }

  115947.   

  115948.       sqlite3VdbeAddOp4(v, OP_MakeRecord, regTemp, nCol, regRec,

  115949.                         sqlite3IndexAffinityStr(pParse->db,pIdx), nCol);

  115950.       sqlite3VdbeAddOp4Int(v, OP_Found, iCur, iOk, regRec, 0); VdbeCoverage(v);

  115951.   

  115952.       sqlite3ReleaseTempReg(pParse, regRec);

  115953.       sqlite3ReleaseTempRange(pParse, regTemp, nCol);

  115954.     }

  115955.   }

  115956. 

  115957.   if( !pFKey->isDeferred && !(pParse->db->flags & SQLITE_DeferFKs)

  115958.    && !pParse->pToplevel 

  115959.    && !pParse->isMultiWrite 

  115960.   ){

  115961.     /* Special case: If this is an INSERT statement that will insert exactly

  115962.     ** one row into the table, raise a constraint immediately instead of

  115963.     ** incrementing a counter. This is necessary as the VM code is being

  115964.     ** generated for will not open a statement transaction.  */

  115965.     assert( nIncr==1 );

  115966.     sqlite3HaltConstraint(pParse, SQLITE_CONSTRAINT_FOREIGNKEY,

  115967.         OE_Abort, 0, P4_STATIC, P5_ConstraintFK);

  115968.   }else{

  115969.     if( nIncr>0 && pFKey->isDeferred==0 ){

  115970.       sqlite3MayAbort(pParse);

  115971.     }

  115972.     sqlite3VdbeAddOp2(v, OP_FkCounter, pFKey->isDeferred, nIncr);

  115973.   }

  115974. 

  115975.   sqlite3VdbeResolveLabel(v, iOk);

  115976.   sqlite3VdbeAddOp1(v, OP_Close, iCur);

  115977. }

  115978. 

  115979. 

  115980. /*

  115981. ** Return an Expr object that refers to a memory register corresponding

  115982. ** to column iCol of table pTab.

  115983. **

  115984. ** regBase is the first of an array of register that contains the data

  115985. ** for pTab.  regBase itself holds the rowid.  regBase+1 holds the first

  115986. ** column.  regBase+2 holds the second column, and so forth.

  115987. */

  115988. static Expr *exprTableRegister(

  115989.   Parse *pParse,     /* Parsing and code generating context */

  115990.   Table *pTab,       /* The table whose content is at r[regBase]... */

  115991.   int regBase,       /* Contents of table pTab */

  115992.   i16 iCol           /* Which column of pTab is desired */

  115993. ){

  115994.   Expr *pExpr;

  115995.   Column *pCol;

  115996.   const char *zColl;

  115997.   sqlite3 *db = pParse->db;

  115998. 

  115999.   pExpr = sqlite3Expr(db, TK_REGISTER, 0);

  116000.   if( pExpr ){

  116001.     if( iCol>=0 && iCol!=pTab->iPKey ){

  116002.       pCol = &pTab->aCol[iCol];

  116003.       pExpr->iTable = regBase + iCol + 1;

  116004.       pExpr->affinity = pCol->affinity;

  116005.       zColl = pCol->zColl;

  116006.       if( zColl==0 ) zColl = db->pDfltColl->zName;

  116007.       pExpr = sqlite3ExprAddCollateString(pParse, pExpr, zColl);

  116008.     }else{

  116009.       pExpr->iTable = regBase;

  116010.       pExpr->affinity = SQLITE_AFF_INTEGER;

  116011.     }

  116012.   }

  116013.   return pExpr;

  116014. }

  116015. 

  116016. /*

  116017. ** Return an Expr object that refers to column iCol of table pTab which

  116018. ** has cursor iCur.

  116019. */

  116020. static Expr *exprTableColumn(

  116021.   sqlite3 *db,      /* The database connection */

  116022.   Table *pTab,      /* The table whose column is desired */

  116023.   int iCursor,      /* The open cursor on the table */

  116024.   i16 iCol          /* The column that is wanted */

  116025. ){

  116026.   Expr *pExpr = sqlite3Expr(db, TK_COLUMN, 0);

  116027.   if( pExpr ){

  116028.     pExpr->y.pTab = pTab;

  116029.     pExpr->iTable = iCursor;

  116030.     pExpr->iColumn = iCol;

  116031.   }

  116032.   return pExpr;

  116033. }

  116034. 

  116035. /*

  116036. ** This function is called to generate code executed when a row is deleted

  116037. ** from the parent table of foreign key constraint pFKey and, if pFKey is 

  116038. ** deferred, when a row is inserted into the same table. When generating

  116039. ** code for an SQL UPDATE operation, this function may be called twice -

  116040. ** once to "delete" the old row and once to "insert" the new row.

  116041. **

  116042. ** Parameter nIncr is passed -1 when inserting a row (as this may decrease

  116043. ** the number of FK violations in the db) or +1 when deleting one (as this

  116044. ** may increase the number of FK constraint problems).

  116045. **

  116046. ** The code generated by this function scans through the rows in the child

  116047. ** table that correspond to the parent table row being deleted or inserted.

  116048. ** For each child row found, one of the following actions is taken:

  116049. **

  116050. **   Operation | FK type   | Action taken

  116051. **   --------------------------------------------------------------------------

  116052. **   DELETE      immediate   Increment the "immediate constraint counter".

  116053. **                           Or, if the ON (UPDATE|DELETE) action is RESTRICT,

  116054. **                           throw a "FOREIGN KEY constraint failed" exception.

  116055. **

  116056. **   INSERT      immediate   Decrement the "immediate constraint counter".

  116057. **

  116058. **   DELETE      deferred    Increment the "deferred constraint counter".

  116059. **                           Or, if the ON (UPDATE|DELETE) action is RESTRICT,

  116060. **                           throw a "FOREIGN KEY constraint failed" exception.

  116061. **

  116062. **   INSERT      deferred    Decrement the "deferred constraint counter".

  116063. **

  116064. ** These operations are identified in the comment at the top of this file 

  116065. ** (fkey.c) as "I.2" and "D.2".

  116066. */

  116067. static void fkScanChildren(

  116068.   Parse *pParse,                  /* Parse context */

  116069.   SrcList *pSrc,                  /* The child table to be scanned */

  116070.   Table *pTab,                    /* The parent table */

  116071.   Index *pIdx,                    /* Index on parent covering the foreign key */

  116072.   FKey *pFKey,                    /* The foreign key linking pSrc to pTab */

  116073.   int *aiCol,                     /* Map from pIdx cols to child table cols */

  116074.   int regData,                    /* Parent row data starts here */

  116075.   int nIncr                       /* Amount to increment deferred counter by */

  116076. ){

  116077.   sqlite3 *db = pParse->db;       /* Database handle */

  116078.   int i;                          /* Iterator variable */

  116079.   Expr *pWhere = 0;               /* WHERE clause to scan with */

  116080.   NameContext sNameContext;       /* Context used to resolve WHERE clause */

  116081.   WhereInfo *pWInfo;              /* Context used by sqlite3WhereXXX() */

  116082.   int iFkIfZero = 0;              /* Address of OP_FkIfZero */

  116083.   Vdbe *v = sqlite3GetVdbe(pParse);

  116084. 

  116085.   assert( pIdx==0 || pIdx->pTable==pTab );

  116086.   assert( pIdx==0 || pIdx->nKeyCol==pFKey->nCol );

  116087.   assert( pIdx!=0 || pFKey->nCol==1 );

  116088.   assert( pIdx!=0 || HasRowid(pTab) );

  116089. 

  116090.   if( nIncr<0 ){

  116091.     iFkIfZero = sqlite3VdbeAddOp2(v, OP_FkIfZero, pFKey->isDeferred, 0);

  116092.     VdbeCoverage(v);

  116093.   }

  116094. 

  116095.   /* Create an Expr object representing an SQL expression like:

  116096.   **

  116097.   **   <parent-key1> = <child-key1> AND <parent-key2> = <child-key2> ...

  116098.   **

  116099.   ** The collation sequence used for the comparison should be that of

  116100.   ** the parent key columns. The affinity of the parent key column should

  116101.   ** be applied to each child key value before the comparison takes place.

  116102.   */

  116103.   for(i=0; i<pFKey->nCol; i++){

  116104.     Expr *pLeft;                  /* Value from parent table row */

  116105.     Expr *pRight;                 /* Column ref to child table */

  116106.     Expr *pEq;                    /* Expression (pLeft = pRight) */

  116107.     i16 iCol;                     /* Index of column in child table */ 

  116108.     const char *zCol;             /* Name of column in child table */

  116109. 

  116110.     iCol = pIdx ? pIdx->aiColumn[i] : -1;

  116111.     pLeft = exprTableRegister(pParse, pTab, regData, iCol);

  116112.     iCol = aiCol ? aiCol[i] : pFKey->aCol[0].iFrom;

  116113.     assert( iCol>=0 );

  116114.     zCol = pFKey->pFrom->aCol[iCol].zName;

  116115.     pRight = sqlite3Expr(db, TK_ID, zCol);

  116116.     pEq = sqlite3PExpr(pParse, TK_EQ, pLeft, pRight);

  116117.     pWhere = sqlite3ExprAnd(pParse, pWhere, pEq);

  116118.   }

  116119. 

  116120.   /* If the child table is the same as the parent table, then add terms

  116121.   ** to the WHERE clause that prevent this entry from being scanned.

  116122.   ** The added WHERE clause terms are like this:

  116123.   **

  116124.   **     $current_rowid!=rowid

  116125.   **     NOT( $current_a==a AND $current_b==b AND ... )

  116126.   **

  116127.   ** The first form is used for rowid tables.  The second form is used

  116128.   ** for WITHOUT ROWID tables. In the second form, the *parent* key is

  116129.   ** (a,b,...). Either the parent or primary key could be used to 

  116130.   ** uniquely identify the current row, but the parent key is more convenient

  116131.   ** as the required values have already been loaded into registers

  116132.   ** by the caller.

  116133.   */

  116134.   if( pTab==pFKey->pFrom && nIncr>0 ){

  116135.     Expr *pNe;                    /* Expression (pLeft != pRight) */

  116136.     Expr *pLeft;                  /* Value from parent table row */

  116137.     Expr *pRight;                 /* Column ref to child table */

  116138.     if( HasRowid(pTab) ){

  116139.       pLeft = exprTableRegister(pParse, pTab, regData, -1);

  116140.       pRight = exprTableColumn(db, pTab, pSrc->a[0].iCursor, -1);

  116141.       pNe = sqlite3PExpr(pParse, TK_NE, pLeft, pRight);

  116142.     }else{

  116143.       Expr *pEq, *pAll = 0;

  116144.       assert( pIdx!=0 );

  116145.       for(i=0; i<pIdx->nKeyCol; i++){

  116146.         i16 iCol = pIdx->aiColumn[i];

  116147.         assert( iCol>=0 );

  116148.         pLeft = exprTableRegister(pParse, pTab, regData, iCol);

  116149.         pRight = sqlite3Expr(db, TK_ID, pTab->aCol[iCol].zName);

  116150.         pEq = sqlite3PExpr(pParse, TK_IS, pLeft, pRight);

  116151.         pAll = sqlite3ExprAnd(pParse, pAll, pEq);

  116152.       }

  116153.       pNe = sqlite3PExpr(pParse, TK_NOT, pAll, 0);

  116154.     }

  116155.     pWhere = sqlite3ExprAnd(pParse, pWhere, pNe);

  116156.   }

  116157. 

  116158.   /* Resolve the references in the WHERE clause. */

  116159.   memset(&sNameContext, 0, sizeof(NameContext));

  116160.   sNameContext.pSrcList = pSrc;

  116161.   sNameContext.pParse = pParse;

  116162.   sqlite3ResolveExprNames(&sNameContext, pWhere);

  116163. 

  116164.   /* Create VDBE to loop through the entries in pSrc that match the WHERE

  116165.   ** clause. For each row found, increment either the deferred or immediate

  116166.   ** foreign key constraint counter. */

  116167.   if( pParse->nErr==0 ){

  116168.     pWInfo = sqlite3WhereBegin(pParse, pSrc, pWhere, 0, 0, 0, 0);

  116169.     sqlite3VdbeAddOp2(v, OP_FkCounter, pFKey->isDeferred, nIncr);

  116170.     if( pWInfo ){

  116171.       sqlite3WhereEnd(pWInfo);

  116172.     }

  116173.   }

  116174. 

  116175.   /* Clean up the WHERE clause constructed above. */

  116176.   sqlite3ExprDelete(db, pWhere);

  116177.   if( iFkIfZero ){

  116178.     sqlite3VdbeJumpHere(v, iFkIfZero);

  116179.   }

  116180. }

  116181. 

  116182. /*

  116183. ** This function returns a linked list of FKey objects (connected by

  116184. ** FKey.pNextTo) holding all children of table pTab.  For example,

  116185. ** given the following schema:

  116186. **

  116187. **   CREATE TABLE t1(a PRIMARY KEY);

  116188. **   CREATE TABLE t2(b REFERENCES t1(a);

  116189. **

  116190. ** Calling this function with table "t1" as an argument returns a pointer

  116191. ** to the FKey structure representing the foreign key constraint on table

  116192. ** "t2". Calling this function with "t2" as the argument would return a

  116193. ** NULL pointer (as there are no FK constraints for which t2 is the parent

  116194. ** table).

  116195. */

  116196. SQLITE_PRIVATE FKey *sqlite3FkReferences(Table *pTab){

  116197.   return (FKey *)sqlite3HashFind(&pTab->pSchema->fkeyHash, pTab->zName);

  116198. }

  116199. 

  116200. /*

  116201. ** The second argument is a Trigger structure allocated by the 

  116202. ** fkActionTrigger() routine. This function deletes the Trigger structure

  116203. ** and all of its sub-components.

  116204. **

  116205. ** The Trigger structure or any of its sub-components may be allocated from

  116206. ** the lookaside buffer belonging to database handle dbMem.

  116207. */

  116208. static void fkTriggerDelete(sqlite3 *dbMem, Trigger *p){

  116209.   if( p ){

  116210.     TriggerStep *pStep = p->step_list;

  116211.     sqlite3ExprDelete(dbMem, pStep->pWhere);

  116212.     sqlite3ExprListDelete(dbMem, pStep->pExprList);

  116213.     sqlite3SelectDelete(dbMem, pStep->pSelect);

  116214.     sqlite3ExprDelete(dbMem, p->pWhen);

  116215.     sqlite3DbFree(dbMem, p);

  116216.   }

  116217. }

  116218. 

  116219. /*

  116220. ** This function is called to generate code that runs when table pTab is

  116221. ** being dropped from the database. The SrcList passed as the second argument

  116222. ** to this function contains a single entry guaranteed to resolve to

  116223. ** table pTab.

  116224. **

  116225. ** Normally, no code is required. However, if either

  116226. **

  116227. **   (a) The table is the parent table of a FK constraint, or

  116228. **   (b) The table is the child table of a deferred FK constraint and it is

  116229. **       determined at runtime that there are outstanding deferred FK 

  116230. **       constraint violations in the database,

  116231. **

  116232. ** then the equivalent of "DELETE FROM <tbl>" is executed before dropping

  116233. ** the table from the database. Triggers are disabled while running this

  116234. ** DELETE, but foreign key actions are not.

  116235. */

  116236. SQLITE_PRIVATE void sqlite3FkDropTable(Parse *pParse, SrcList *pName, Table *pTab){

  116237.   sqlite3 *db = pParse->db;

  116238.   if( (db->flags&SQLITE_ForeignKeys) && !IsVirtual(pTab) ){

  116239.     int iSkip = 0;

  116240.     Vdbe *v = sqlite3GetVdbe(pParse);

  116241. 

  116242.     assert( v );                  /* VDBE has already been allocated */

  116243.     assert( pTab->pSelect==0 );   /* Not a view */

  116244.     if( sqlite3FkReferences(pTab)==0 ){

  116245.       /* Search for a deferred foreign key constraint for which this table

  116246.       ** is the child table. If one cannot be found, return without 

  116247.       ** generating any VDBE code. If one can be found, then jump over

  116248.       ** the entire DELETE if there are no outstanding deferred constraints

  116249.       ** when this statement is run.  */

  116250.       FKey *p;

  116251.       for(p=pTab->pFKey; p; p=p->pNextFrom){

  116252.         if( p->isDeferred || (db->flags & SQLITE_DeferFKs) ) break;

  116253.       }

  116254.       if( !p ) return;

  116255.       iSkip = sqlite3VdbeMakeLabel(pParse);

  116256.       sqlite3VdbeAddOp2(v, OP_FkIfZero, 1, iSkip); VdbeCoverage(v);

  116257.     }

  116258. 

  116259.     pParse->disableTriggers = 1;

  116260.     sqlite3DeleteFrom(pParse, sqlite3SrcListDup(db, pName, 0), 0, 0, 0);

  116261.     pParse->disableTriggers = 0;

  116262. 

  116263.     /* If the DELETE has generated immediate foreign key constraint 

  116264.     ** violations, halt the VDBE and return an error at this point, before

  116265.     ** any modifications to the schema are made. This is because statement

  116266.     ** transactions are not able to rollback schema changes.  

  116267.     **

  116268.     ** If the SQLITE_DeferFKs flag is set, then this is not required, as

  116269.     ** the statement transaction will not be rolled back even if FK

  116270.     ** constraints are violated.

  116271.     */

  116272.     if( (db->flags & SQLITE_DeferFKs)==0 ){

  116273.       sqlite3VdbeVerifyAbortable(v, OE_Abort);

  116274.       sqlite3VdbeAddOp2(v, OP_FkIfZero, 0, sqlite3VdbeCurrentAddr(v)+2);

  116275.       VdbeCoverage(v);

  116276.       sqlite3HaltConstraint(pParse, SQLITE_CONSTRAINT_FOREIGNKEY,

  116277.           OE_Abort, 0, P4_STATIC, P5_ConstraintFK);

  116278.     }

  116279. 

  116280.     if( iSkip ){

  116281.       sqlite3VdbeResolveLabel(v, iSkip);

  116282.     }

  116283.   }

  116284. }

  116285. 

  116286. 

  116287. /*

  116288. ** The second argument points to an FKey object representing a foreign key

  116289. ** for which pTab is the child table. An UPDATE statement against pTab

  116290. ** is currently being processed. For each column of the table that is 

  116291. ** actually updated, the corresponding element in the aChange[] array

  116292. ** is zero or greater (if a column is unmodified the corresponding element

  116293. ** is set to -1). If the rowid column is modified by the UPDATE statement

  116294. ** the bChngRowid argument is non-zero.

  116295. **

  116296. ** This function returns true if any of the columns that are part of the

  116297. ** child key for FK constraint *p are modified.

  116298. */

  116299. static int fkChildIsModified(

  116300.   Table *pTab,                    /* Table being updated */

  116301.   FKey *p,                        /* Foreign key for which pTab is the child */

  116302.   int *aChange,                   /* Array indicating modified columns */

  116303.   int bChngRowid                  /* True if rowid is modified by this update */

  116304. ){

  116305.   int i;

  116306.   for(i=0; i<p->nCol; i++){

  116307.     int iChildKey = p->aCol[i].iFrom;

  116308.     if( aChange[iChildKey]>=0 ) return 1;

  116309.     if( iChildKey==pTab->iPKey && bChngRowid ) return 1;

  116310.   }

  116311.   return 0;

  116312. }

  116313. 

  116314. /*

  116315. ** The second argument points to an FKey object representing a foreign key

  116316. ** for which pTab is the parent table. An UPDATE statement against pTab

  116317. ** is currently being processed. For each column of the table that is 

  116318. ** actually updated, the corresponding element in the aChange[] array

  116319. ** is zero or greater (if a column is unmodified the corresponding element

  116320. ** is set to -1). If the rowid column is modified by the UPDATE statement

  116321. ** the bChngRowid argument is non-zero.

  116322. **

  116323. ** This function returns true if any of the columns that are part of the

  116324. ** parent key for FK constraint *p are modified.

  116325. */

  116326. static int fkParentIsModified(

  116327.   Table *pTab, 

  116328.   FKey *p, 

  116329.   int *aChange, 

  116330.   int bChngRowid

  116331. ){

  116332.   int i;

  116333.   for(i=0; i<p->nCol; i++){

  116334.     char *zKey = p->aCol[i].zCol;

  116335.     int iKey;

  116336.     for(iKey=0; iKey<pTab->nCol; iKey++){

  116337.       if( aChange[iKey]>=0 || (iKey==pTab->iPKey && bChngRowid) ){

  116338.         Column *pCol = &pTab->aCol[iKey];

  116339.         if( zKey ){

  116340.           if( 0==sqlite3StrICmp(pCol->zName, zKey) ) return 1;

  116341.         }else if( pCol->colFlags & COLFLAG_PRIMKEY ){

  116342.           return 1;

  116343.         }

  116344.       }

  116345.     }

  116346.   }

  116347.   return 0;

  116348. }

  116349. 

  116350. /*

  116351. ** Return true if the parser passed as the first argument is being

  116352. ** used to code a trigger that is really a "SET NULL" action belonging

  116353. ** to trigger pFKey.

  116354. */

  116355. static int isSetNullAction(Parse *pParse, FKey *pFKey){

  116356.   Parse *pTop = sqlite3ParseToplevel(pParse);

  116357.   if( pTop->pTriggerPrg ){

  116358.     Trigger *p = pTop->pTriggerPrg->pTrigger;

  116359.     if( (p==pFKey->apTrigger[0] && pFKey->aAction[0]==OE_SetNull)

  116360.      || (p==pFKey->apTrigger[1] && pFKey->aAction[1]==OE_SetNull)

  116361.     ){

  116362.       return 1;

  116363.     }

  116364.   }

  116365.   return 0;

  116366. }

  116367. 

  116368. /*

  116369. ** This function is called when inserting, deleting or updating a row of

  116370. ** table pTab to generate VDBE code to perform foreign key constraint 

  116371. ** processing for the operation.

  116372. **

  116373. ** For a DELETE operation, parameter regOld is passed the index of the

  116374. ** first register in an array of (pTab->nCol+1) registers containing the

  116375. ** rowid of the row being deleted, followed by each of the column values

  116376. ** of the row being deleted, from left to right. Parameter regNew is passed

  116377. ** zero in this case.

  116378. **

  116379. ** For an INSERT operation, regOld is passed zero and regNew is passed the

  116380. ** first register of an array of (pTab->nCol+1) registers containing the new

  116381. ** row data.

  116382. **

  116383. ** For an UPDATE operation, this function is called twice. Once before

  116384. ** the original record is deleted from the table using the calling convention

  116385. ** described for DELETE. Then again after the original record is deleted

  116386. ** but before the new record is inserted using the INSERT convention. 

  116387. */

  116388. SQLITE_PRIVATE void sqlite3FkCheck(

  116389.   Parse *pParse,                  /* Parse context */

  116390.   Table *pTab,                    /* Row is being deleted from this table */ 

  116391.   int regOld,                     /* Previous row data is stored here */

  116392.   int regNew,                     /* New row data is stored here */

  116393.   int *aChange,                   /* Array indicating UPDATEd columns (or 0) */

  116394.   int bChngRowid                  /* True if rowid is UPDATEd */

  116395. ){

  116396.   sqlite3 *db = pParse->db;       /* Database handle */

  116397.   FKey *pFKey;                    /* Used to iterate through FKs */

  116398.   int iDb;                        /* Index of database containing pTab */

  116399.   const char *zDb;                /* Name of database containing pTab */

  116400.   int isIgnoreErrors = pParse->disableTriggers;

  116401. 

  116402.   /* Exactly one of regOld and regNew should be non-zero. */

  116403.   assert( (regOld==0)!=(regNew==0) );

  116404. 

  116405.   /* If foreign-keys are disabled, this function is a no-op. */

  116406.   if( (db->flags&SQLITE_ForeignKeys)==0 ) return;

  116407. 

  116408.   iDb = sqlite3SchemaToIndex(db, pTab->pSchema);

  116409.   zDb = db->aDb[iDb].zDbSName;

  116410. 

  116411.   /* Loop through all the foreign key constraints for which pTab is the

  116412.   ** child table (the table that the foreign key definition is part of).  */

  116413.   for(pFKey=pTab->pFKey; pFKey; pFKey=pFKey->pNextFrom){

  116414.     Table *pTo;                   /* Parent table of foreign key pFKey */

  116415.     Index *pIdx = 0;              /* Index on key columns in pTo */

  116416.     int *aiFree = 0;

  116417.     int *aiCol;

  116418.     int iCol;

  116419.     int i;

  116420.     int bIgnore = 0;

  116421. 

  116422.     if( aChange 

  116423.      && sqlite3_stricmp(pTab->zName, pFKey->zTo)!=0

  116424.      && fkChildIsModified(pTab, pFKey, aChange, bChngRowid)==0 

  116425.     ){

  116426.       continue;

  116427.     }

  116428. 

  116429.     /* Find the parent table of this foreign key. Also find a unique index 

  116430.     ** on the parent key columns in the parent table. If either of these 

  116431.     ** schema items cannot be located, set an error in pParse and return 

  116432.     ** early.  */

  116433.     if( pParse->disableTriggers ){

  116434.       pTo = sqlite3FindTable(db, pFKey->zTo, zDb);

  116435.     }else{

  116436.       pTo = sqlite3LocateTable(pParse, 0, pFKey->zTo, zDb);

  116437.     }

  116438.     if( !pTo || sqlite3FkLocateIndex(pParse, pTo, pFKey, &pIdx, &aiFree) ){

  116439.       assert( isIgnoreErrors==0 || (regOld!=0 && regNew==0) );

  116440.       if( !isIgnoreErrors || db->mallocFailed ) return;

  116441.       if( pTo==0 ){

  116442.         /* If isIgnoreErrors is true, then a table is being dropped. In this

  116443.         ** case SQLite runs a "DELETE FROM xxx" on the table being dropped

  116444.         ** before actually dropping it in order to check FK constraints.

  116445.         ** If the parent table of an FK constraint on the current table is

  116446.         ** missing, behave as if it is empty. i.e. decrement the relevant

  116447.         ** FK counter for each row of the current table with non-NULL keys.

  116448.         */

  116449.         Vdbe *v = sqlite3GetVdbe(pParse);

  116450.         int iJump = sqlite3VdbeCurrentAddr(v) + pFKey->nCol + 1;

  116451.         for(i=0; i<pFKey->nCol; i++){

  116452.           int iReg = pFKey->aCol[i].iFrom + regOld + 1;

  116453.           sqlite3VdbeAddOp2(v, OP_IsNull, iReg, iJump); VdbeCoverage(v);

  116454.         }

  116455.         sqlite3VdbeAddOp2(v, OP_FkCounter, pFKey->isDeferred, -1);

  116456.       }

  116457.       continue;

  116458.     }

  116459.     assert( pFKey->nCol==1 || (aiFree && pIdx) );

  116460. 

  116461.     if( aiFree ){

  116462.       aiCol = aiFree;

  116463.     }else{

  116464.       iCol = pFKey->aCol[0].iFrom;

  116465.       aiCol = &iCol;

  116466.     }

  116467.     for(i=0; i<pFKey->nCol; i++){

  116468.       if( aiCol[i]==pTab->iPKey ){

  116469.         aiCol[i] = -1;

  116470.       }

  116471.       assert( pIdx==0 || pIdx->aiColumn[i]>=0 );

  116472. #ifndef SQLITE_OMIT_AUTHORIZATION

  116473.       /* Request permission to read the parent key columns. If the 

  116474.       ** authorization callback returns SQLITE_IGNORE, behave as if any

  116475.       ** values read from the parent table are NULL. */

  116476.       if( db->xAuth ){

  116477.         int rcauth;

  116478.         char *zCol = pTo->aCol[pIdx ? pIdx->aiColumn[i] : pTo->iPKey].zName;

  116479.         rcauth = sqlite3AuthReadCol(pParse, pTo->zName, zCol, iDb);

  116480.         bIgnore = (rcauth==SQLITE_IGNORE);

  116481.       }

  116482. #endif

  116483.     }

  116484. 

  116485.     /* Take a shared-cache advisory read-lock on the parent table. Allocate 

  116486.     ** a cursor to use to search the unique index on the parent key columns 

  116487.     ** in the parent table.  */

  116488.     sqlite3TableLock(pParse, iDb, pTo->tnum, 0, pTo->zName);

  116489.     pParse->nTab++;

  116490. 

  116491.     if( regOld!=0 ){

  116492.       /* A row is being removed from the child table. Search for the parent.

  116493.       ** If the parent does not exist, removing the child row resolves an 

  116494.       ** outstanding foreign key constraint violation. */

  116495.       fkLookupParent(pParse, iDb, pTo, pIdx, pFKey, aiCol, regOld, -1, bIgnore);

  116496.     }

  116497.     if( regNew!=0 && !isSetNullAction(pParse, pFKey) ){

  116498.       /* A row is being added to the child table. If a parent row cannot

  116499.       ** be found, adding the child row has violated the FK constraint. 

  116500.       **

  116501.       ** If this operation is being performed as part of a trigger program

  116502.       ** that is actually a "SET NULL" action belonging to this very 

  116503.       ** foreign key, then omit this scan altogether. As all child key

  116504.       ** values are guaranteed to be NULL, it is not possible for adding

  116505.       ** this row to cause an FK violation.  */

  116506.       fkLookupParent(pParse, iDb, pTo, pIdx, pFKey, aiCol, regNew, +1, bIgnore);

  116507.     }

  116508. 

  116509.     sqlite3DbFree(db, aiFree);

  116510.   }

  116511. 

  116512.   /* Loop through all the foreign key constraints that refer to this table.

  116513.   ** (the "child" constraints) */

  116514.   for(pFKey = sqlite3FkReferences(pTab); pFKey; pFKey=pFKey->pNextTo){

  116515.     Index *pIdx = 0;              /* Foreign key index for pFKey */

  116516.     SrcList *pSrc;

  116517.     int *aiCol = 0;

  116518. 

  116519.     if( aChange && fkParentIsModified(pTab, pFKey, aChange, bChngRowid)==0 ){

  116520.       continue;

  116521.     }

  116522. 

  116523.     if( !pFKey->isDeferred && !(db->flags & SQLITE_DeferFKs) 

  116524.      && !pParse->pToplevel && !pParse->isMultiWrite 

  116525.     ){

  116526.       assert( regOld==0 && regNew!=0 );

  116527.       /* Inserting a single row into a parent table cannot cause (or fix)

  116528.       ** an immediate foreign key violation. So do nothing in this case.  */

  116529.       continue;

  116530.     }

  116531. 

  116532.     if( sqlite3FkLocateIndex(pParse, pTab, pFKey, &pIdx, &aiCol) ){

  116533.       if( !isIgnoreErrors || db->mallocFailed ) return;

  116534.       continue;

  116535.     }

  116536.     assert( aiCol || pFKey->nCol==1 );

  116537. 

  116538.     /* Create a SrcList structure containing the child table.  We need the

  116539.     ** child table as a SrcList for sqlite3WhereBegin() */

  116540.     pSrc = sqlite3SrcListAppend(pParse, 0, 0, 0);

  116541.     if( pSrc ){

  116542.       struct SrcList_item *pItem = pSrc->a;

  116543.       pItem->pTab = pFKey->pFrom;

  116544.       pItem->zName = pFKey->pFrom->zName;

  116545.       pItem->pTab->nTabRef++;

  116546.       pItem->iCursor = pParse->nTab++;

  116547.   

  116548.       if( regNew!=0 ){

  116549.         fkScanChildren(pParse, pSrc, pTab, pIdx, pFKey, aiCol, regNew, -1);

  116550.       }

  116551.       if( regOld!=0 ){

  116552.         int eAction = pFKey->aAction[aChange!=0];

  116553.         fkScanChildren(pParse, pSrc, pTab, pIdx, pFKey, aiCol, regOld, 1);

  116554.         /* If this is a deferred FK constraint, or a CASCADE or SET NULL

  116555.         ** action applies, then any foreign key violations caused by

  116556.         ** removing the parent key will be rectified by the action trigger.

  116557.         ** So do not set the "may-abort" flag in this case.

  116558.         **

  116559.         ** Note 1: If the FK is declared "ON UPDATE CASCADE", then the

  116560.         ** may-abort flag will eventually be set on this statement anyway

  116561.         ** (when this function is called as part of processing the UPDATE

  116562.         ** within the action trigger).

  116563.         **

  116564.         ** Note 2: At first glance it may seem like SQLite could simply omit

  116565.         ** all OP_FkCounter related scans when either CASCADE or SET NULL

  116566.         ** applies. The trouble starts if the CASCADE or SET NULL action 

  116567.         ** trigger causes other triggers or action rules attached to the 

  116568.         ** child table to fire. In these cases the fk constraint counters

  116569.         ** might be set incorrectly if any OP_FkCounter related scans are 

  116570.         ** omitted.  */

  116571.         if( !pFKey->isDeferred && eAction!=OE_Cascade && eAction!=OE_SetNull ){

  116572.           sqlite3MayAbort(pParse);

  116573.         }

  116574.       }

  116575.       pItem->zName = 0;

  116576.       sqlite3SrcListDelete(db, pSrc);

  116577.     }

  116578.     sqlite3DbFree(db, aiCol);

  116579.   }

  116580. }

  116581. 

  116582. #define COLUMN_MASK(x) (((x)>31) ? 0xffffffff : ((u32)1<<(x)))

  116583. 

  116584. /*

  116585. ** This function is called before generating code to update or delete a 

  116586. ** row contained in table pTab.

  116587. */

  116588. SQLITE_PRIVATE u32 sqlite3FkOldmask(

  116589.   Parse *pParse,                  /* Parse context */

  116590.   Table *pTab                     /* Table being modified */

  116591. ){

  116592.   u32 mask = 0;

  116593.   if( pParse->db->flags&SQLITE_ForeignKeys ){

  116594.     FKey *p;

  116595.     int i;

  116596.     for(p=pTab->pFKey; p; p=p->pNextFrom){

  116597.       for(i=0; i<p->nCol; i++) mask |= COLUMN_MASK(p->aCol[i].iFrom);

  116598.     }

  116599.     for(p=sqlite3FkReferences(pTab); p; p=p->pNextTo){

  116600.       Index *pIdx = 0;

  116601.       sqlite3FkLocateIndex(pParse, pTab, p, &pIdx, 0);

  116602.       if( pIdx ){

  116603.         for(i=0; i<pIdx->nKeyCol; i++){

  116604.           assert( pIdx->aiColumn[i]>=0 );

  116605.           mask |= COLUMN_MASK(pIdx->aiColumn[i]);

  116606.         }

  116607.       }

  116608.     }

  116609.   }

  116610.   return mask;

  116611. }

  116612. 

  116613. 

  116614. /*

  116615. ** This function is called before generating code to update or delete a 

  116616. ** row contained in table pTab. If the operation is a DELETE, then

  116617. ** parameter aChange is passed a NULL value. For an UPDATE, aChange points

  116618. ** to an array of size N, where N is the number of columns in table pTab.

  116619. ** If the i'th column is not modified by the UPDATE, then the corresponding 

  116620. ** entry in the aChange[] array is set to -1. If the column is modified,

  116621. ** the value is 0 or greater. Parameter chngRowid is set to true if the

  116622. ** UPDATE statement modifies the rowid fields of the table.

  116623. **

  116624. ** If any foreign key processing will be required, this function returns

  116625. ** non-zero. If there is no foreign key related processing, this function 

  116626. ** returns zero.

  116627. **

  116628. ** For an UPDATE, this function returns 2 if:

  116629. **

  116630. **   * There are any FKs for which pTab is the child and the parent table, or

  116631. **   * the UPDATE modifies one or more parent keys for which the action is

  116632. **     not "NO ACTION" (i.e. is CASCADE, SET DEFAULT or SET NULL).

  116633. **

  116634. ** Or, assuming some other foreign key processing is required, 1.

  116635. */

  116636. SQLITE_PRIVATE int sqlite3FkRequired(

  116637.   Parse *pParse,                  /* Parse context */

  116638.   Table *pTab,                    /* Table being modified */

  116639.   int *aChange,                   /* Non-NULL for UPDATE operations */

  116640.   int chngRowid                   /* True for UPDATE that affects rowid */

  116641. ){

  116642.   int eRet = 0;

  116643.   if( pParse->db->flags&SQLITE_ForeignKeys ){

  116644.     if( !aChange ){

  116645.       /* A DELETE operation. Foreign key processing is required if the 

  116646.       ** table in question is either the child or parent table for any 

  116647.       ** foreign key constraint.  */

  116648.       eRet = (sqlite3FkReferences(pTab) || pTab->pFKey);

  116649.     }else{

  116650.       /* This is an UPDATE. Foreign key processing is only required if the

  116651.       ** operation modifies one or more child or parent key columns. */

  116652.       FKey *p;

  116653. 

  116654.       /* Check if any child key columns are being modified. */

  116655.       for(p=pTab->pFKey; p; p=p->pNextFrom){

  116656.         if( 0==sqlite3_stricmp(pTab->zName, p->zTo) ) return 2;

  116657.         if( fkChildIsModified(pTab, p, aChange, chngRowid) ){

  116658.           eRet = 1;

  116659.         }

  116660.       }

  116661. 

  116662.       /* Check if any parent key columns are being modified. */

  116663.       for(p=sqlite3FkReferences(pTab); p; p=p->pNextTo){

  116664.         if( fkParentIsModified(pTab, p, aChange, chngRowid) ){

  116665.           if( p->aAction[1]!=OE_None ) return 2;

  116666.           eRet = 1;

  116667.         }

  116668.       }

  116669.     }

  116670.   }

  116671.   return eRet;

  116672. }

  116673. 

  116674. /*

  116675. ** This function is called when an UPDATE or DELETE operation is being 

  116676. ** compiled on table pTab, which is the parent table of foreign-key pFKey.

  116677. ** If the current operation is an UPDATE, then the pChanges parameter is

  116678. ** passed a pointer to the list of columns being modified. If it is a

  116679. ** DELETE, pChanges is passed a NULL pointer.

  116680. **

  116681. ** It returns a pointer to a Trigger structure containing a trigger

  116682. ** equivalent to the ON UPDATE or ON DELETE action specified by pFKey.

  116683. ** If the action is "NO ACTION" or "RESTRICT", then a NULL pointer is

  116684. ** returned (these actions require no special handling by the triggers

  116685. ** sub-system, code for them is created by fkScanChildren()).

  116686. **

  116687. ** For example, if pFKey is the foreign key and pTab is table "p" in 

  116688. ** the following schema:

  116689. **

  116690. **   CREATE TABLE p(pk PRIMARY KEY);

  116691. **   CREATE TABLE c(ck REFERENCES p ON DELETE CASCADE);

  116692. **

  116693. ** then the returned trigger structure is equivalent to:

  116694. **

  116695. **   CREATE TRIGGER ... DELETE ON p BEGIN

  116696. **     DELETE FROM c WHERE ck = old.pk;

  116697. **   END;

  116698. **

  116699. ** The returned pointer is cached as part of the foreign key object. It

  116700. ** is eventually freed along with the rest of the foreign key object by 

  116701. ** sqlite3FkDelete().

  116702. */

  116703. static Trigger *fkActionTrigger(

  116704.   Parse *pParse,                  /* Parse context */

  116705.   Table *pTab,                    /* Table being updated or deleted from */

  116706.   FKey *pFKey,                    /* Foreign key to get action for */

  116707.   ExprList *pChanges              /* Change-list for UPDATE, NULL for DELETE */

  116708. ){

  116709.   sqlite3 *db = pParse->db;       /* Database handle */

  116710.   int action;                     /* One of OE_None, OE_Cascade etc. */

  116711.   Trigger *pTrigger;              /* Trigger definition to return */

  116712.   int iAction = (pChanges!=0);    /* 1 for UPDATE, 0 for DELETE */

  116713. 

  116714.   action = pFKey->aAction[iAction];

  116715.   if( action==OE_Restrict && (db->flags & SQLITE_DeferFKs) ){

  116716.     return 0;

  116717.   }

  116718.   pTrigger = pFKey->apTrigger[iAction];

  116719. 

  116720.   if( action!=OE_None && !pTrigger ){

  116721.     char const *zFrom;            /* Name of child table */

  116722.     int nFrom;                    /* Length in bytes of zFrom */

  116723.     Index *pIdx = 0;              /* Parent key index for this FK */

  116724.     int *aiCol = 0;               /* child table cols -> parent key cols */

  116725.     TriggerStep *pStep = 0;        /* First (only) step of trigger program */

  116726.     Expr *pWhere = 0;             /* WHERE clause of trigger step */

  116727.     ExprList *pList = 0;          /* Changes list if ON UPDATE CASCADE */

  116728.     Select *pSelect = 0;          /* If RESTRICT, "SELECT RAISE(...)" */

  116729.     int i;                        /* Iterator variable */

  116730.     Expr *pWhen = 0;              /* WHEN clause for the trigger */

  116731. 

  116732.     if( sqlite3FkLocateIndex(pParse, pTab, pFKey, &pIdx, &aiCol) ) return 0;

  116733.     assert( aiCol || pFKey->nCol==1 );

  116734. 

  116735.     for(i=0; i<pFKey->nCol; i++){

  116736.       Token tOld = { "old", 3 };  /* Literal "old" token */

  116737.       Token tNew = { "new", 3 };  /* Literal "new" token */

  116738.       Token tFromCol;             /* Name of column in child table */

  116739.       Token tToCol;               /* Name of column in parent table */

  116740.       int iFromCol;               /* Idx of column in child table */

  116741.       Expr *pEq;                  /* tFromCol = OLD.tToCol */

  116742. 

  116743.       iFromCol = aiCol ? aiCol[i] : pFKey->aCol[0].iFrom;

  116744.       assert( iFromCol>=0 );

  116745.       assert( pIdx!=0 || (pTab->iPKey>=0 && pTab->iPKey<pTab->nCol) );

  116746.       assert( pIdx==0 || pIdx->aiColumn[i]>=0 );

  116747.       sqlite3TokenInit(&tToCol,

  116748.                    pTab->aCol[pIdx ? pIdx->aiColumn[i] : pTab->iPKey].zName);

  116749.       sqlite3TokenInit(&tFromCol, pFKey->pFrom->aCol[iFromCol].zName);

  116750. 

  116751.       /* Create the expression "OLD.zToCol = zFromCol". It is important

  116752.       ** that the "OLD.zToCol" term is on the LHS of the = operator, so

  116753.       ** that the affinity and collation sequence associated with the

  116754.       ** parent table are used for the comparison. */

  116755.       pEq = sqlite3PExpr(pParse, TK_EQ,

  116756.           sqlite3PExpr(pParse, TK_DOT, 

  116757.             sqlite3ExprAlloc(db, TK_ID, &tOld, 0),

  116758.             sqlite3ExprAlloc(db, TK_ID, &tToCol, 0)),

  116759.           sqlite3ExprAlloc(db, TK_ID, &tFromCol, 0)

  116760.       );

  116761.       pWhere = sqlite3ExprAnd(pParse, pWhere, pEq);

  116762. 

  116763.       /* For ON UPDATE, construct the next term of the WHEN clause.

  116764.       ** The final WHEN clause will be like this:

  116765.       **

  116766.       **    WHEN NOT(old.col1 IS new.col1 AND ... AND old.colN IS new.colN)

  116767.       */

  116768.       if( pChanges ){

  116769.         pEq = sqlite3PExpr(pParse, TK_IS,

  116770.             sqlite3PExpr(pParse, TK_DOT, 

  116771.               sqlite3ExprAlloc(db, TK_ID, &tOld, 0),

  116772.               sqlite3ExprAlloc(db, TK_ID, &tToCol, 0)),

  116773.             sqlite3PExpr(pParse, TK_DOT, 

  116774.               sqlite3ExprAlloc(db, TK_ID, &tNew, 0),

  116775.               sqlite3ExprAlloc(db, TK_ID, &tToCol, 0))

  116776.             );

  116777.         pWhen = sqlite3ExprAnd(pParse, pWhen, pEq);

  116778.       }

  116779.   

  116780.       if( action!=OE_Restrict && (action!=OE_Cascade || pChanges) ){

  116781.         Expr *pNew;

  116782.         if( action==OE_Cascade ){

  116783.           pNew = sqlite3PExpr(pParse, TK_DOT, 

  116784.             sqlite3ExprAlloc(db, TK_ID, &tNew, 0),

  116785.             sqlite3ExprAlloc(db, TK_ID, &tToCol, 0));

  116786.         }else if( action==OE_SetDflt ){

  116787.           Expr *pDflt = pFKey->pFrom->aCol[iFromCol].pDflt;

  116788.           if( pDflt ){

  116789.             pNew = sqlite3ExprDup(db, pDflt, 0);

  116790.           }else{

  116791.             pNew = sqlite3ExprAlloc(db, TK_NULL, 0, 0);

  116792.           }

  116793.         }else{

  116794.           pNew = sqlite3ExprAlloc(db, TK_NULL, 0, 0);

  116795.         }

  116796.         pList = sqlite3ExprListAppend(pParse, pList, pNew);

  116797.         sqlite3ExprListSetName(pParse, pList, &tFromCol, 0);

  116798.       }

  116799.     }

  116800.     sqlite3DbFree(db, aiCol);

  116801. 

  116802.     zFrom = pFKey->pFrom->zName;

  116803.     nFrom = sqlite3Strlen30(zFrom);

  116804. 

  116805.     if( action==OE_Restrict ){

  116806.       Token tFrom;

  116807.       Expr *pRaise; 

  116808. 

  116809.       tFrom.z = zFrom;

  116810.       tFrom.n = nFrom;

  116811.       pRaise = sqlite3Expr(db, TK_RAISE, "FOREIGN KEY constraint failed");

  116812.       if( pRaise ){

  116813.         pRaise->affinity = OE_Abort;

  116814.       }

  116815.       pSelect = sqlite3SelectNew(pParse, 

  116816.           sqlite3ExprListAppend(pParse, 0, pRaise),

  116817.           sqlite3SrcListAppend(pParse, 0, &tFrom, 0),

  116818.           pWhere,

  116819.           0, 0, 0, 0, 0

  116820.       );

  116821.       pWhere = 0;

  116822.     }

  116823. 

  116824.     /* Disable lookaside memory allocation */

  116825.     db->lookaside.bDisable++;

  116826. 

  116827.     pTrigger = (Trigger *)sqlite3DbMallocZero(db, 

  116828.         sizeof(Trigger) +         /* struct Trigger */

  116829.         sizeof(TriggerStep) +     /* Single step in trigger program */

  116830.         nFrom + 1                 /* Space for pStep->zTarget */

  116831.     );

  116832.     if( pTrigger ){

  116833.       pStep = pTrigger->step_list = (TriggerStep *)&pTrigger[1];

  116834.       pStep->zTarget = (char *)&pStep[1];

  116835.       memcpy((char *)pStep->zTarget, zFrom, nFrom);

  116836.   

  116837.       pStep->pWhere = sqlite3ExprDup(db, pWhere, EXPRDUP_REDUCE);

  116838.       pStep->pExprList = sqlite3ExprListDup(db, pList, EXPRDUP_REDUCE);

  116839.       pStep->pSelect = sqlite3SelectDup(db, pSelect, EXPRDUP_REDUCE);

  116840.       if( pWhen ){

  116841.         pWhen = sqlite3PExpr(pParse, TK_NOT, pWhen, 0);

  116842.         pTrigger->pWhen = sqlite3ExprDup(db, pWhen, EXPRDUP_REDUCE);

  116843.       }

  116844.     }

  116845. 

  116846.     /* Re-enable the lookaside buffer, if it was disabled earlier. */

  116847.     db->lookaside.bDisable--;

  116848. 

  116849.     sqlite3ExprDelete(db, pWhere);

  116850.     sqlite3ExprDelete(db, pWhen);

  116851.     sqlite3ExprListDelete(db, pList);

  116852.     sqlite3SelectDelete(db, pSelect);

  116853.     if( db->mallocFailed==1 ){

  116854.       fkTriggerDelete(db, pTrigger);

  116855.       return 0;

  116856.     }

  116857.     assert( pStep!=0 );

  116858. 

  116859.     switch( action ){

  116860.       case OE_Restrict:

  116861.         pStep->op = TK_SELECT; 

  116862.         break;

  116863.       case OE_Cascade: 

  116864.         if( !pChanges ){ 

  116865.           pStep->op = TK_DELETE; 

  116866.           break; 

  116867.         }

  116868.       default:

  116869.         pStep->op = TK_UPDATE;

  116870.     }

  116871.     pStep->pTrig = pTrigger;

  116872.     pTrigger->pSchema = pTab->pSchema;

  116873.     pTrigger->pTabSchema = pTab->pSchema;

  116874.     pFKey->apTrigger[iAction] = pTrigger;

  116875.     pTrigger->op = (pChanges ? TK_UPDATE : TK_DELETE);

  116876.   }

  116877. 

  116878.   return pTrigger;

  116879. }

  116880. 

  116881. /*

  116882. ** This function is called when deleting or updating a row to implement

  116883. ** any required CASCADE, SET NULL or SET DEFAULT actions.

  116884. */

  116885. SQLITE_PRIVATE void sqlite3FkActions(

  116886.   Parse *pParse,                  /* Parse context */

  116887.   Table *pTab,                    /* Table being updated or deleted from */

  116888.   ExprList *pChanges,             /* Change-list for UPDATE, NULL for DELETE */

  116889.   int regOld,                     /* Address of array containing old row */

  116890.   int *aChange,                   /* Array indicating UPDATEd columns (or 0) */

  116891.   int bChngRowid                  /* True if rowid is UPDATEd */

  116892. ){

  116893.   /* If foreign-key support is enabled, iterate through all FKs that 

  116894.   ** refer to table pTab. If there is an action associated with the FK 

  116895.   ** for this operation (either update or delete), invoke the associated 

  116896.   ** trigger sub-program.  */

  116897.   if( pParse->db->flags&SQLITE_ForeignKeys ){

  116898.     FKey *pFKey;                  /* Iterator variable */

  116899.     for(pFKey = sqlite3FkReferences(pTab); pFKey; pFKey=pFKey->pNextTo){

  116900.       if( aChange==0 || fkParentIsModified(pTab, pFKey, aChange, bChngRowid) ){

  116901.         Trigger *pAct = fkActionTrigger(pParse, pTab, pFKey, pChanges);

  116902.         if( pAct ){

  116903.           sqlite3CodeRowTriggerDirect(pParse, pAct, pTab, regOld, OE_Abort, 0);

  116904.         }

  116905.       }

  116906.     }

  116907.   }

  116908. }

  116909. 

  116910. #endif /* ifndef SQLITE_OMIT_TRIGGER */

  116911. 

  116912. /*

  116913. ** Free all memory associated with foreign key definitions attached to

  116914. ** table pTab. Remove the deleted foreign keys from the Schema.fkeyHash

  116915. ** hash table.

  116916. */

  116917. SQLITE_PRIVATE void sqlite3FkDelete(sqlite3 *db, Table *pTab){

  116918.   FKey *pFKey;                    /* Iterator variable */

  116919.   FKey *pNext;                    /* Copy of pFKey->pNextFrom */

  116920. 

  116921.   assert( db==0 || IsVirtual(pTab)

  116922.          || sqlite3SchemaMutexHeld(db, 0, pTab->pSchema) );

  116923.   for(pFKey=pTab->pFKey; pFKey; pFKey=pNext){

  116924. 

  116925.     /* Remove the FK from the fkeyHash hash table. */

  116926.     if( !db || db->pnBytesFreed==0 ){

  116927.       if( pFKey->pPrevTo ){

  116928.         pFKey->pPrevTo->pNextTo = pFKey->pNextTo;

  116929.       }else{

  116930.         void *p = (void *)pFKey->pNextTo;

  116931.         const char *z = (p ? pFKey->pNextTo->zTo : pFKey->zTo);

  116932.         sqlite3HashInsert(&pTab->pSchema->fkeyHash, z, p);

  116933.       }

  116934.       if( pFKey->pNextTo ){

  116935.         pFKey->pNextTo->pPrevTo = pFKey->pPrevTo;

  116936.       }

  116937.     }

  116938. 

  116939.     /* EV: R-30323-21917 Each foreign key constraint in SQLite is

  116940.     ** classified as either immediate or deferred.

  116941.     */

  116942.     assert( pFKey->isDeferred==0 || pFKey->isDeferred==1 );

  116943. 

  116944.     /* Delete any triggers created to implement actions for this FK. */

  116945. #ifndef SQLITE_OMIT_TRIGGER

  116946.     fkTriggerDelete(db, pFKey->apTrigger[0]);

  116947.     fkTriggerDelete(db, pFKey->apTrigger[1]);

  116948. #endif

  116949. 

  116950.     pNext = pFKey->pNextFrom;

  116951.     sqlite3DbFree(db, pFKey);

  116952.   }

  116953. }

  116954. #endif /* ifndef SQLITE_OMIT_FOREIGN_KEY */

  116955. 

  116956. /************** End of fkey.c ************************************************/

  116957. /************** Begin file insert.c ******************************************/

  116958. /*

  116959. ** 2001 September 15

  116960. **

  116961. ** The author disclaims copyright to this source code.  In place of

  116962. ** a legal notice, here is a blessing:

  116963. **

  116964. **    May you do good and not evil.

  116965. **    May you find forgiveness for yourself and forgive others.

  116966. **    May you share freely, never taking more than you give.

  116967. **

  116968. *************************************************************************

  116969. ** This file contains C code routines that are called by the parser

  116970. ** to handle INSERT statements in SQLite.

  116971. */

  116972. /* #include "sqliteInt.h" */

  116973. 

  116974. /*

  116975. ** Generate code that will 

  116976. **

  116977. **   (1) acquire a lock for table pTab then

  116978. **   (2) open pTab as cursor iCur.

  116979. **

  116980. ** If pTab is a WITHOUT ROWID table, then it is the PRIMARY KEY index

  116981. ** for that table that is actually opened.

  116982. */

  116983. SQLITE_PRIVATE void sqlite3OpenTable(

  116984.   Parse *pParse,  /* Generate code into this VDBE */

  116985.   int iCur,       /* The cursor number of the table */

  116986.   int iDb,        /* The database index in sqlite3.aDb[] */

  116987.   Table *pTab,    /* The table to be opened */

  116988.   int opcode      /* OP_OpenRead or OP_OpenWrite */

  116989. ){

  116990.   Vdbe *v;

  116991.   assert( !IsVirtual(pTab) );

  116992.   v = sqlite3GetVdbe(pParse);

  116993.   assert( opcode==OP_OpenWrite || opcode==OP_OpenRead );

  116994.   sqlite3TableLock(pParse, iDb, pTab->tnum, 

  116995.                    (opcode==OP_OpenWrite)?1:0, pTab->zName);

  116996.   if( HasRowid(pTab) ){

  116997.     sqlite3VdbeAddOp4Int(v, opcode, iCur, pTab->tnum, iDb, pTab->nCol);

  116998.     VdbeComment((v, "%s", pTab->zName));

  116999.   }else{

  117000.     Index *pPk = sqlite3PrimaryKeyIndex(pTab);

  117001.     assert( pPk!=0 );

  117002.     assert( pPk->tnum==pTab->tnum );

  117003.     sqlite3VdbeAddOp3(v, opcode, iCur, pPk->tnum, iDb);

  117004.     sqlite3VdbeSetP4KeyInfo(pParse, pPk);

  117005.     VdbeComment((v, "%s", pTab->zName));

  117006.   }

  117007. }

  117008. 

  117009. /*

  117010. ** Return a pointer to the column affinity string associated with index

  117011. ** pIdx. A column affinity string has one character for each column in 

  117012. ** the table, according to the affinity of the column:

  117013. **

  117014. **  Character      Column affinity

  117015. **  ------------------------------

  117016. **  'A'            BLOB

  117017. **  'B'            TEXT

  117018. **  'C'            NUMERIC

  117019. **  'D'            INTEGER

  117020. **  'F'            REAL

  117021. **

  117022. ** An extra 'D' is appended to the end of the string to cover the

  117023. ** rowid that appears as the last column in every index.

  117024. **

  117025. ** Memory for the buffer containing the column index affinity string

  117026. ** is managed along with the rest of the Index structure. It will be

  117027. ** released when sqlite3DeleteIndex() is called.

  117028. */

  117029. SQLITE_PRIVATE const char *sqlite3IndexAffinityStr(sqlite3 *db, Index *pIdx){

  117030.   if( !pIdx->zColAff ){

  117031.     /* The first time a column affinity string for a particular index is

  117032.     ** required, it is allocated and populated here. It is then stored as

  117033.     ** a member of the Index structure for subsequent use.

  117034.     **

  117035.     ** The column affinity string will eventually be deleted by

  117036.     ** sqliteDeleteIndex() when the Index structure itself is cleaned

  117037.     ** up.

  117038.     */

  117039.     int n;

  117040.     Table *pTab = pIdx->pTable;

  117041.     pIdx->zColAff = (char *)sqlite3DbMallocRaw(0, pIdx->nColumn+1);

  117042.     if( !pIdx->zColAff ){

  117043.       sqlite3OomFault(db);

  117044.       return 0;

  117045.     }

  117046.     for(n=0; n<pIdx->nColumn; n++){

  117047.       i16 x = pIdx->aiColumn[n];

  117048.       if( x>=0 ){

  117049.         pIdx->zColAff[n] = pTab->aCol[x].affinity;

  117050.       }else if( x==XN_ROWID ){

  117051.         pIdx->zColAff[n] = SQLITE_AFF_INTEGER;

  117052.       }else{

  117053.         char aff;

  117054.         assert( x==XN_EXPR );

  117055.         assert( pIdx->aColExpr!=0 );

  117056.         aff = sqlite3ExprAffinity(pIdx->aColExpr->a[n].pExpr);

  117057.         if( aff==0 ) aff = SQLITE_AFF_BLOB;

  117058.         pIdx->zColAff[n] = aff;

  117059.       }

  117060.     }

  117061.     pIdx->zColAff[n] = 0;

  117062.   }

  117063.  

  117064.   return pIdx->zColAff;

  117065. }

  117066. 

  117067. /*

  117068. ** Compute the affinity string for table pTab, if it has not already been

  117069. ** computed.  As an optimization, omit trailing SQLITE_AFF_BLOB affinities.

  117070. **

  117071. ** If the affinity exists (if it is no entirely SQLITE_AFF_BLOB values) and

  117072. ** if iReg>0 then code an OP_Affinity opcode that will set the affinities

  117073. ** for register iReg and following.  Or if affinities exists and iReg==0,

  117074. ** then just set the P4 operand of the previous opcode (which should  be

  117075. ** an OP_MakeRecord) to the affinity string.

  117076. **

  117077. ** A column affinity string has one character per column:

  117078. **

  117079. **  Character      Column affinity

  117080. **  ------------------------------

  117081. **  'A'            BLOB

  117082. **  'B'            TEXT

  117083. **  'C'            NUMERIC

  117084. **  'D'            INTEGER

  117085. **  'E'            REAL

  117086. */

  117087. SQLITE_PRIVATE void sqlite3TableAffinity(Vdbe *v, Table *pTab, int iReg){

  117088.   int i;

  117089.   char *zColAff = pTab->zColAff;

  117090.   if( zColAff==0 ){

  117091.     sqlite3 *db = sqlite3VdbeDb(v);

  117092.     zColAff = (char *)sqlite3DbMallocRaw(0, pTab->nCol+1);

  117093.     if( !zColAff ){

  117094.       sqlite3OomFault(db);

  117095.       return;

  117096.     }

  117097. 

  117098.     for(i=0; i<pTab->nCol; i++){

  117099.       zColAff[i] = pTab->aCol[i].affinity;

  117100.     }

  117101.     do{

  117102.       zColAff[i--] = 0;

  117103.     }while( i>=0 && zColAff[i]==SQLITE_AFF_BLOB );

  117104.     pTab->zColAff = zColAff;

  117105.   }

  117106.   assert( zColAff!=0 );

  117107.   i = sqlite3Strlen30NN(zColAff);

  117108.   if( i ){

  117109.     if( iReg ){

  117110.       sqlite3VdbeAddOp4(v, OP_Affinity, iReg, i, 0, zColAff, i);

  117111.     }else{

  117112.       sqlite3VdbeChangeP4(v, -1, zColAff, i);

  117113.     }

  117114.   }

  117115. }

  117116. 

  117117. /*

  117118. ** Return non-zero if the table pTab in database iDb or any of its indices

  117119. ** have been opened at any point in the VDBE program. This is used to see if 

  117120. ** a statement of the form  "INSERT INTO <iDb, pTab> SELECT ..." can 

  117121. ** run without using a temporary table for the results of the SELECT. 

  117122. */

  117123. static int readsTable(Parse *p, int iDb, Table *pTab){

  117124.   Vdbe *v = sqlite3GetVdbe(p);

  117125.   int i;

  117126.   int iEnd = sqlite3VdbeCurrentAddr(v);

  117127. #ifndef SQLITE_OMIT_VIRTUALTABLE

  117128.   VTable *pVTab = IsVirtual(pTab) ? sqlite3GetVTable(p->db, pTab) : 0;

  117129. #endif

  117130. 

  117131.   for(i=1; i<iEnd; i++){

  117132.     VdbeOp *pOp = sqlite3VdbeGetOp(v, i);

  117133.     assert( pOp!=0 );

  117134.     if( pOp->opcode==OP_OpenRead && pOp->p3==iDb ){

  117135.       Index *pIndex;

  117136.       int tnum = pOp->p2;

  117137.       if( tnum==pTab->tnum ){

  117138.         return 1;

  117139.       }

  117140.       for(pIndex=pTab->pIndex; pIndex; pIndex=pIndex->pNext){

  117141.         if( tnum==pIndex->tnum ){

  117142.           return 1;

  117143.         }

  117144.       }

  117145.     }

  117146. #ifndef SQLITE_OMIT_VIRTUALTABLE

  117147.     if( pOp->opcode==OP_VOpen && pOp->p4.pVtab==pVTab ){

  117148.       assert( pOp->p4.pVtab!=0 );

  117149.       assert( pOp->p4type==P4_VTAB );

  117150.       return 1;

  117151.     }

  117152. #endif

  117153.   }

  117154.   return 0;

  117155. }

  117156. 

  117157. #ifndef SQLITE_OMIT_AUTOINCREMENT

  117158. /*

  117159. ** Locate or create an AutoincInfo structure associated with table pTab

  117160. ** which is in database iDb.  Return the register number for the register

  117161. ** that holds the maximum rowid.  Return zero if pTab is not an AUTOINCREMENT

  117162. ** table.  (Also return zero when doing a VACUUM since we do not want to

  117163. ** update the AUTOINCREMENT counters during a VACUUM.)

  117164. **

  117165. ** There is at most one AutoincInfo structure per table even if the

  117166. ** same table is autoincremented multiple times due to inserts within

  117167. ** triggers.  A new AutoincInfo structure is created if this is the

  117168. ** first use of table pTab.  On 2nd and subsequent uses, the original

  117169. ** AutoincInfo structure is used.

  117170. **

  117171. ** Four consecutive registers are allocated:

  117172. **

  117173. **   (1)  The name of the pTab table.

  117174. **   (2)  The maximum ROWID of pTab.

  117175. **   (3)  The rowid in sqlite_sequence of pTab

  117176. **   (4)  The original value of the max ROWID in pTab, or NULL if none

  117177. **

  117178. ** The 2nd register is the one that is returned.  That is all the

  117179. ** insert routine needs to know about.

  117180. */

  117181. static int autoIncBegin(

  117182.   Parse *pParse,      /* Parsing context */

  117183.   int iDb,            /* Index of the database holding pTab */

  117184.   Table *pTab         /* The table we are writing to */

  117185. ){

  117186.   int memId = 0;      /* Register holding maximum rowid */

  117187.   assert( pParse->db->aDb[iDb].pSchema!=0 );

  117188.   if( (pTab->tabFlags & TF_Autoincrement)!=0

  117189.    && (pParse->db->mDbFlags & DBFLAG_Vacuum)==0

  117190.   ){

  117191.     Parse *pToplevel = sqlite3ParseToplevel(pParse);

  117192.     AutoincInfo *pInfo;

  117193.     Table *pSeqTab = pParse->db->aDb[iDb].pSchema->pSeqTab;

  117194. 

  117195.     /* Verify that the sqlite_sequence table exists and is an ordinary

  117196.     ** rowid table with exactly two columns.

  117197.     ** Ticket d8dc2b3a58cd5dc2918a1d4acb 2018-05-23 */

  117198.     if( pSeqTab==0

  117199.      || !HasRowid(pSeqTab)

  117200.      || IsVirtual(pSeqTab)

  117201.      || pSeqTab->nCol!=2

  117202.     ){

  117203.       pParse->nErr++;

  117204.       pParse->rc = SQLITE_CORRUPT_SEQUENCE;

  117205.       return 0;

  117206.     }

  117207. 

  117208.     pInfo = pToplevel->pAinc;

  117209.     while( pInfo && pInfo->pTab!=pTab ){ pInfo = pInfo->pNext; }

  117210.     if( pInfo==0 ){

  117211.       pInfo = sqlite3DbMallocRawNN(pParse->db, sizeof(*pInfo));

  117212.       if( pInfo==0 ) return 0;

  117213.       pInfo->pNext = pToplevel->pAinc;

  117214.       pToplevel->pAinc = pInfo;

  117215.       pInfo->pTab = pTab;

  117216.       pInfo->iDb = iDb;

  117217.       pToplevel->nMem++;                  /* Register to hold name of table */

  117218.       pInfo->regCtr = ++pToplevel->nMem;  /* Max rowid register */

  117219.       pToplevel->nMem +=2;       /* Rowid in sqlite_sequence + orig max val */

  117220.     }

  117221.     memId = pInfo->regCtr;

  117222.   }

  117223.   return memId;

  117224. }

  117225. 

  117226. /*

  117227. ** This routine generates code that will initialize all of the

  117228. ** register used by the autoincrement tracker.  

  117229. */

  117230. SQLITE_PRIVATE void sqlite3AutoincrementBegin(Parse *pParse){

  117231.   AutoincInfo *p;            /* Information about an AUTOINCREMENT */

  117232.   sqlite3 *db = pParse->db;  /* The database connection */

  117233.   Db *pDb;                   /* Database only autoinc table */

  117234.   int memId;                 /* Register holding max rowid */

  117235.   Vdbe *v = pParse->pVdbe;   /* VDBE under construction */

  117236. 

  117237.   /* This routine is never called during trigger-generation.  It is

  117238.   ** only called from the top-level */

  117239.   assert( pParse->pTriggerTab==0 );

  117240.   assert( sqlite3IsToplevel(pParse) );

  117241. 

  117242.   assert( v );   /* We failed long ago if this is not so */

  117243.   for(p = pParse->pAinc; p; p = p->pNext){

  117244.     static const int iLn = VDBE_OFFSET_LINENO(2);

  117245.     static const VdbeOpList autoInc[] = {

  117246.       /* 0  */ {OP_Null,    0,  0, 0},

  117247.       /* 1  */ {OP_Rewind,  0, 10, 0},

  117248.       /* 2  */ {OP_Column,  0,  0, 0},

  117249.       /* 3  */ {OP_Ne,      0,  9, 0},

  117250.       /* 4  */ {OP_Rowid,   0,  0, 0},

  117251.       /* 5  */ {OP_Column,  0,  1, 0},

  117252.       /* 6  */ {OP_AddImm,  0,  0, 0},

  117253.       /* 7  */ {OP_Copy,    0,  0, 0},

  117254.       /* 8  */ {OP_Goto,    0, 11, 0},

  117255.       /* 9  */ {OP_Next,    0,  2, 0},

  117256.       /* 10 */ {OP_Integer, 0,  0, 0},

  117257.       /* 11 */ {OP_Close,   0,  0, 0} 

  117258.     };

  117259.     VdbeOp *aOp;

  117260.     pDb = &db->aDb[p->iDb];

  117261.     memId = p->regCtr;

  117262.     assert( sqlite3SchemaMutexHeld(db, 0, pDb->pSchema) );

  117263.     sqlite3OpenTable(pParse, 0, p->iDb, pDb->pSchema->pSeqTab, OP_OpenRead);

  117264.     sqlite3VdbeLoadString(v, memId-1, p->pTab->zName);

  117265.     aOp = sqlite3VdbeAddOpList(v, ArraySize(autoInc), autoInc, iLn);

  117266.     if( aOp==0 ) break;

  117267.     aOp[0].p2 = memId;

  117268.     aOp[0].p3 = memId+2;

  117269.     aOp[2].p3 = memId;

  117270.     aOp[3].p1 = memId-1;

  117271.     aOp[3].p3 = memId;

  117272.     aOp[3].p5 = SQLITE_JUMPIFNULL;

  117273.     aOp[4].p2 = memId+1;

  117274.     aOp[5].p3 = memId;

  117275.     aOp[6].p1 = memId;

  117276.     aOp[7].p2 = memId+2;

  117277.     aOp[7].p1 = memId;

  117278.     aOp[10].p2 = memId;

  117279.     if( pParse->nTab==0 ) pParse->nTab = 1;

  117280.   }

  117281. }

  117282. 

  117283. /*

  117284. ** Update the maximum rowid for an autoincrement calculation.

  117285. **

  117286. ** This routine should be called when the regRowid register holds a

  117287. ** new rowid that is about to be inserted.  If that new rowid is

  117288. ** larger than the maximum rowid in the memId memory cell, then the

  117289. ** memory cell is updated.

  117290. */

  117291. static void autoIncStep(Parse *pParse, int memId, int regRowid){

  117292.   if( memId>0 ){

  117293.     sqlite3VdbeAddOp2(pParse->pVdbe, OP_MemMax, memId, regRowid);

  117294.   }

  117295. }

  117296. 

  117297. /*

  117298. ** This routine generates the code needed to write autoincrement

  117299. ** maximum rowid values back into the sqlite_sequence register.

  117300. ** Every statement that might do an INSERT into an autoincrement

  117301. ** table (either directly or through triggers) needs to call this

  117302. ** routine just before the "exit" code.

  117303. */

  117304. static SQLITE_NOINLINE void autoIncrementEnd(Parse *pParse){

  117305.   AutoincInfo *p;

  117306.   Vdbe *v = pParse->pVdbe;

  117307.   sqlite3 *db = pParse->db;

  117308. 

  117309.   assert( v );

  117310.   for(p = pParse->pAinc; p; p = p->pNext){

  117311.     static const int iLn = VDBE_OFFSET_LINENO(2);

  117312.     static const VdbeOpList autoIncEnd[] = {

  117313.       /* 0 */ {OP_NotNull,     0, 2, 0},

  117314.       /* 1 */ {OP_NewRowid,    0, 0, 0},

  117315.       /* 2 */ {OP_MakeRecord,  0, 2, 0},

  117316.       /* 3 */ {OP_Insert,      0, 0, 0},

  117317.       /* 4 */ {OP_Close,       0, 0, 0}

  117318.     };

  117319.     VdbeOp *aOp;

  117320.     Db *pDb = &db->aDb[p->iDb];

  117321.     int iRec;

  117322.     int memId = p->regCtr;

  117323. 

  117324.     iRec = sqlite3GetTempReg(pParse);

  117325.     assert( sqlite3SchemaMutexHeld(db, 0, pDb->pSchema) );

  117326.     sqlite3VdbeAddOp3(v, OP_Le, memId+2, sqlite3VdbeCurrentAddr(v)+7, memId);

  117327.     VdbeCoverage(v);

  117328.     sqlite3OpenTable(pParse, 0, p->iDb, pDb->pSchema->pSeqTab, OP_OpenWrite);

  117329.     aOp = sqlite3VdbeAddOpList(v, ArraySize(autoIncEnd), autoIncEnd, iLn);

  117330.     if( aOp==0 ) break;

  117331.     aOp[0].p1 = memId+1;

  117332.     aOp[1].p2 = memId+1;

  117333.     aOp[2].p1 = memId-1;

  117334.     aOp[2].p3 = iRec;

  117335.     aOp[3].p2 = iRec;

  117336.     aOp[3].p3 = memId+1;

  117337.     aOp[3].p5 = OPFLAG_APPEND;

  117338.     sqlite3ReleaseTempReg(pParse, iRec);

  117339.   }

  117340. }

  117341. SQLITE_PRIVATE void sqlite3AutoincrementEnd(Parse *pParse){

  117342.   if( pParse->pAinc ) autoIncrementEnd(pParse);

  117343. }

  117344. #else

  117345. /*

  117346. ** If SQLITE_OMIT_AUTOINCREMENT is defined, then the three routines

  117347. ** above are all no-ops

  117348. */

  117349. # define autoIncBegin(A,B,C) (0)

  117350. # define autoIncStep(A,B,C)

  117351. #endif /* SQLITE_OMIT_AUTOINCREMENT */

  117352. 

  117353. 

  117354. /* Forward declaration */

  117355. static int xferOptimization(

  117356.   Parse *pParse,        /* Parser context */

  117357.   Table *pDest,         /* The table we are inserting into */

  117358.   Select *pSelect,      /* A SELECT statement to use as the data source */

  117359.   int onError,          /* How to handle constraint errors */

  117360.   int iDbDest           /* The database of pDest */

  117361. );

  117362. 

  117363. /*

  117364. ** This routine is called to handle SQL of the following forms:

  117365. **

  117366. **    insert into TABLE (IDLIST) values(EXPRLIST),(EXPRLIST),...

  117367. **    insert into TABLE (IDLIST) select

  117368. **    insert into TABLE (IDLIST) default values

  117369. **

  117370. ** The IDLIST following the table name is always optional.  If omitted,

  117371. ** then a list of all (non-hidden) columns for the table is substituted.

  117372. ** The IDLIST appears in the pColumn parameter.  pColumn is NULL if IDLIST

  117373. ** is omitted.

  117374. **

  117375. ** For the pSelect parameter holds the values to be inserted for the

  117376. ** first two forms shown above.  A VALUES clause is really just short-hand

  117377. ** for a SELECT statement that omits the FROM clause and everything else

  117378. ** that follows.  If the pSelect parameter is NULL, that means that the

  117379. ** DEFAULT VALUES form of the INSERT statement is intended.

  117380. **

  117381. ** The code generated follows one of four templates.  For a simple

  117382. ** insert with data coming from a single-row VALUES clause, the code executes

  117383. ** once straight down through.  Pseudo-code follows (we call this

  117384. ** the "1st template"):

  117385. **

  117386. **         open write cursor to <table> and its indices

  117387. **         put VALUES clause expressions into registers

  117388. **         write the resulting record into <table>

  117389. **         cleanup

  117390. **

  117391. ** The three remaining templates assume the statement is of the form

  117392. **

  117393. **   INSERT INTO <table> SELECT ...

  117394. **

  117395. ** If the SELECT clause is of the restricted form "SELECT * FROM <table2>" -

  117396. ** in other words if the SELECT pulls all columns from a single table

  117397. ** and there is no WHERE or LIMIT or GROUP BY or ORDER BY clauses, and

  117398. ** if <table2> and <table1> are distinct tables but have identical

  117399. ** schemas, including all the same indices, then a special optimization

  117400. ** is invoked that copies raw records from <table2> over to <table1>.

  117401. ** See the xferOptimization() function for the implementation of this

  117402. ** template.  This is the 2nd template.

  117403. **

  117404. **         open a write cursor to <table>

  117405. **         open read cursor on <table2>

  117406. **         transfer all records in <table2> over to <table>

  117407. **         close cursors

  117408. **         foreach index on <table>

  117409. **           open a write cursor on the <table> index

  117410. **           open a read cursor on the corresponding <table2> index

  117411. **           transfer all records from the read to the write cursors

  117412. **           close cursors

  117413. **         end foreach

  117414. **

  117415. ** The 3rd template is for when the second template does not apply

  117416. ** and the SELECT clause does not read from <table> at any time.

  117417. ** The generated code follows this template:

  117418. **

  117419. **         X <- A

  117420. **         goto B

  117421. **      A: setup for the SELECT

  117422. **         loop over the rows in the SELECT

  117423. **           load values into registers R..R+n

  117424. **           yield X

  117425. **         end loop

  117426. **         cleanup after the SELECT

  117427. **         end-coroutine X

  117428. **      B: open write cursor to <table> and its indices

  117429. **      C: yield X, at EOF goto D

  117430. **         insert the select result into <table> from R..R+n

  117431. **         goto C

  117432. **      D: cleanup

  117433. **

  117434. ** The 4th template is used if the insert statement takes its

  117435. ** values from a SELECT but the data is being inserted into a table

  117436. ** that is also read as part of the SELECT.  In the third form,

  117437. ** we have to use an intermediate table to store the results of

  117438. ** the select.  The template is like this:

  117439. **

  117440. **         X <- A

  117441. **         goto B

  117442. **      A: setup for the SELECT

  117443. **         loop over the tables in the SELECT

  117444. **           load value into register R..R+n

  117445. **           yield X

  117446. **         end loop

  117447. **         cleanup after the SELECT

  117448. **         end co-routine R

  117449. **      B: open temp table

  117450. **      L: yield X, at EOF goto M

  117451. **         insert row from R..R+n into temp table

  117452. **         goto L

  117453. **      M: open write cursor to <table> and its indices

  117454. **         rewind temp table

  117455. **      C: loop over rows of intermediate table

  117456. **           transfer values form intermediate table into <table>

  117457. **         end loop

  117458. **      D: cleanup

  117459. */

  117460. SQLITE_PRIVATE void sqlite3Insert(

  117461.   Parse *pParse,        /* Parser context */

  117462.   SrcList *pTabList,    /* Name of table into which we are inserting */

  117463.   Select *pSelect,      /* A SELECT statement to use as the data source */

  117464.   IdList *pColumn,      /* Column names corresponding to IDLIST. */

  117465.   int onError,          /* How to handle constraint errors */

  117466.   Upsert *pUpsert       /* ON CONFLICT clauses for upsert, or NULL */

  117467. ){

  117468.   sqlite3 *db;          /* The main database structure */

  117469.   Table *pTab;          /* The table to insert into.  aka TABLE */

  117470.   int i, j;             /* Loop counters */

  117471.   Vdbe *v;              /* Generate code into this virtual machine */

  117472.   Index *pIdx;          /* For looping over indices of the table */

  117473.   int nColumn;          /* Number of columns in the data */

  117474.   int nHidden = 0;      /* Number of hidden columns if TABLE is virtual */

  117475.   int iDataCur = 0;     /* VDBE cursor that is the main data repository */

  117476.   int iIdxCur = 0;      /* First index cursor */

  117477.   int ipkColumn = -1;   /* Column that is the INTEGER PRIMARY KEY */

  117478.   int endOfLoop;        /* Label for the end of the insertion loop */

  117479.   int srcTab = 0;       /* Data comes from this temporary cursor if >=0 */

  117480.   int addrInsTop = 0;   /* Jump to label "D" */

  117481.   int addrCont = 0;     /* Top of insert loop. Label "C" in templates 3 and 4 */

  117482.   SelectDest dest;      /* Destination for SELECT on rhs of INSERT */

  117483.   int iDb;              /* Index of database holding TABLE */

  117484.   u8 useTempTable = 0;  /* Store SELECT results in intermediate table */

  117485.   u8 appendFlag = 0;    /* True if the insert is likely to be an append */

  117486.   u8 withoutRowid;      /* 0 for normal table.  1 for WITHOUT ROWID table */

  117487.   u8 bIdListInOrder;    /* True if IDLIST is in table order */

  117488.   ExprList *pList = 0;  /* List of VALUES() to be inserted  */

  117489. 

  117490.   /* Register allocations */

  117491.   int regFromSelect = 0;/* Base register for data coming from SELECT */

  117492.   int regAutoinc = 0;   /* Register holding the AUTOINCREMENT counter */

  117493.   int regRowCount = 0;  /* Memory cell used for the row counter */

  117494.   int regIns;           /* Block of regs holding rowid+data being inserted */

  117495.   int regRowid;         /* registers holding insert rowid */

  117496.   int regData;          /* register holding first column to insert */

  117497.   int *aRegIdx = 0;     /* One register allocated to each index */

  117498. 

  117499. #ifndef SQLITE_OMIT_TRIGGER

  117500.   int isView;                 /* True if attempting to insert into a view */

  117501.   Trigger *pTrigger;          /* List of triggers on pTab, if required */

  117502.   int tmask;                  /* Mask of trigger times */

  117503. #endif

  117504. 

  117505.   db = pParse->db;

  117506.   if( pParse->nErr || db->mallocFailed ){

  117507.     goto insert_cleanup;

  117508.   }

  117509.   dest.iSDParm = 0;  /* Suppress a harmless compiler warning */

  117510. 

  117511.   /* If the Select object is really just a simple VALUES() list with a

  117512.   ** single row (the common case) then keep that one row of values

  117513.   ** and discard the other (unused) parts of the pSelect object

  117514.   */

  117515.   if( pSelect && (pSelect->selFlags & SF_Values)!=0 && pSelect->pPrior==0 ){

  117516.     pList = pSelect->pEList;

  117517.     pSelect->pEList = 0;

  117518.     sqlite3SelectDelete(db, pSelect);

  117519.     pSelect = 0;

  117520.   }

  117521. 

  117522.   /* Locate the table into which we will be inserting new information.

  117523.   */

  117524.   assert( pTabList->nSrc==1 );

  117525.   pTab = sqlite3SrcListLookup(pParse, pTabList);

  117526.   if( pTab==0 ){

  117527.     goto insert_cleanup;

  117528.   }

  117529.   iDb = sqlite3SchemaToIndex(db, pTab->pSchema);

  117530.   assert( iDb<db->nDb );

  117531.   if( sqlite3AuthCheck(pParse, SQLITE_INSERT, pTab->zName, 0,

  117532.                        db->aDb[iDb].zDbSName) ){

  117533.     goto insert_cleanup;

  117534.   }

  117535.   withoutRowid = !HasRowid(pTab);

  117536. 

  117537.   /* Figure out if we have any triggers and if the table being

  117538.   ** inserted into is a view

  117539.   */

  117540. #ifndef SQLITE_OMIT_TRIGGER

  117541.   pTrigger = sqlite3TriggersExist(pParse, pTab, TK_INSERT, 0, &tmask);

  117542.   isView = pTab->pSelect!=0;

  117543. #else

  117544. # define pTrigger 0

  117545. # define tmask 0

  117546. # define isView 0

  117547. #endif

  117548. #ifdef SQLITE_OMIT_VIEW

  117549. # undef isView

  117550. # define isView 0

  117551. #endif

  117552.   assert( (pTrigger && tmask) || (pTrigger==0 && tmask==0) );

  117553. 

  117554.   /* If pTab is really a view, make sure it has been initialized.

  117555.   ** ViewGetColumnNames() is a no-op if pTab is not a view.

  117556.   */

  117557.   if( sqlite3ViewGetColumnNames(pParse, pTab) ){

  117558.     goto insert_cleanup;

  117559.   }

  117560. 

  117561.   /* Cannot insert into a read-only table.

  117562.   */

  117563.   if( sqlite3IsReadOnly(pParse, pTab, tmask) ){

  117564.     goto insert_cleanup;

  117565.   }

  117566. 

  117567.   /* Allocate a VDBE

  117568.   */

  117569.   v = sqlite3GetVdbe(pParse);

  117570.   if( v==0 ) goto insert_cleanup;

  117571.   if( pParse->nested==0 ) sqlite3VdbeCountChanges(v);

  117572.   sqlite3BeginWriteOperation(pParse, pSelect || pTrigger, iDb);

  117573. 

  117574. #ifndef SQLITE_OMIT_XFER_OPT

  117575.   /* If the statement is of the form

  117576.   **

  117577.   **       INSERT INTO <table1> SELECT * FROM <table2>;

  117578.   **

  117579.   ** Then special optimizations can be applied that make the transfer

  117580.   ** very fast and which reduce fragmentation of indices.

  117581.   **

  117582.   ** This is the 2nd template.

  117583.   */

  117584.   if( pColumn==0 && xferOptimization(pParse, pTab, pSelect, onError, iDb) ){

  117585.     assert( !pTrigger );

  117586.     assert( pList==0 );

  117587.     goto insert_end;

  117588.   }

  117589. #endif /* SQLITE_OMIT_XFER_OPT */

  117590. 

  117591.   /* If this is an AUTOINCREMENT table, look up the sequence number in the

  117592.   ** sqlite_sequence table and store it in memory cell regAutoinc.

  117593.   */

  117594.   regAutoinc = autoIncBegin(pParse, iDb, pTab);

  117595. 

  117596.   /* Allocate registers for holding the rowid of the new row,

  117597.   ** the content of the new row, and the assembled row record.

  117598.   */

  117599.   regRowid = regIns = pParse->nMem+1;

  117600.   pParse->nMem += pTab->nCol + 1;

  117601.   if( IsVirtual(pTab) ){

  117602.     regRowid++;

  117603.     pParse->nMem++;

  117604.   }

  117605.   regData = regRowid+1;

  117606. 

  117607.   /* If the INSERT statement included an IDLIST term, then make sure

  117608.   ** all elements of the IDLIST really are columns of the table and 

  117609.   ** remember the column indices.

  117610.   **

  117611.   ** If the table has an INTEGER PRIMARY KEY column and that column

  117612.   ** is named in the IDLIST, then record in the ipkColumn variable

  117613.   ** the index into IDLIST of the primary key column.  ipkColumn is

  117614.   ** the index of the primary key as it appears in IDLIST, not as

  117615.   ** is appears in the original table.  (The index of the INTEGER

  117616.   ** PRIMARY KEY in the original table is pTab->iPKey.)

  117617.   */

  117618.   bIdListInOrder = (pTab->tabFlags & TF_OOOHidden)==0;

  117619.   if( pColumn ){

  117620.     for(i=0; i<pColumn->nId; i++){

  117621.       pColumn->a[i].idx = -1;

  117622.     }

  117623.     for(i=0; i<pColumn->nId; i++){

  117624.       for(j=0; j<pTab->nCol; j++){

  117625.         if( sqlite3StrICmp(pColumn->a[i].zName, pTab->aCol[j].zName)==0 ){

  117626.           pColumn->a[i].idx = j;

  117627.           if( i!=j ) bIdListInOrder = 0;

  117628.           if( j==pTab->iPKey ){

  117629.             ipkColumn = i;  assert( !withoutRowid );

  117630.           }

  117631.           break;

  117632.         }

  117633.       }

  117634.       if( j>=pTab->nCol ){

  117635.         if( sqlite3IsRowid(pColumn->a[i].zName) && !withoutRowid ){

  117636.           ipkColumn = i;

  117637.           bIdListInOrder = 0;

  117638.         }else{

  117639.           sqlite3ErrorMsg(pParse, "table %S has no column named %s",

  117640.               pTabList, 0, pColumn->a[i].zName);

  117641.           pParse->checkSchema = 1;

  117642.           goto insert_cleanup;

  117643.         }

  117644.       }

  117645.     }

  117646.   }

  117647. 

  117648.   /* Figure out how many columns of data are supplied.  If the data

  117649.   ** is coming from a SELECT statement, then generate a co-routine that

  117650.   ** produces a single row of the SELECT on each invocation.  The

  117651.   ** co-routine is the common header to the 3rd and 4th templates.

  117652.   */

  117653.   if( pSelect ){

  117654.     /* Data is coming from a SELECT or from a multi-row VALUES clause.

  117655.     ** Generate a co-routine to run the SELECT. */

  117656.     int regYield;       /* Register holding co-routine entry-point */

  117657.     int addrTop;        /* Top of the co-routine */

  117658.     int rc;             /* Result code */

  117659. 

  117660.     regYield = ++pParse->nMem;

  117661.     addrTop = sqlite3VdbeCurrentAddr(v) + 1;

  117662.     sqlite3VdbeAddOp3(v, OP_InitCoroutine, regYield, 0, addrTop);

  117663.     sqlite3SelectDestInit(&dest, SRT_Coroutine, regYield);

  117664.     dest.iSdst = bIdListInOrder ? regData : 0;

  117665.     dest.nSdst = pTab->nCol;

  117666.     rc = sqlite3Select(pParse, pSelect, &dest);

  117667.     regFromSelect = dest.iSdst;

  117668.     if( rc || db->mallocFailed || pParse->nErr ) goto insert_cleanup;

  117669.     sqlite3VdbeEndCoroutine(v, regYield);

  117670.     sqlite3VdbeJumpHere(v, addrTop - 1);                       /* label B: */

  117671.     assert( pSelect->pEList );

  117672.     nColumn = pSelect->pEList->nExpr;

  117673. 

  117674.     /* Set useTempTable to TRUE if the result of the SELECT statement

  117675.     ** should be written into a temporary table (template 4).  Set to

  117676.     ** FALSE if each output row of the SELECT can be written directly into

  117677.     ** the destination table (template 3).

  117678.     **

  117679.     ** A temp table must be used if the table being updated is also one

  117680.     ** of the tables being read by the SELECT statement.  Also use a 

  117681.     ** temp table in the case of row triggers.

  117682.     */

  117683.     if( pTrigger || readsTable(pParse, iDb, pTab) ){

  117684.       useTempTable = 1;

  117685.     }

  117686. 

  117687.     if( useTempTable ){

  117688.       /* Invoke the coroutine to extract information from the SELECT

  117689.       ** and add it to a transient table srcTab.  The code generated

  117690.       ** here is from the 4th template:

  117691.       **

  117692.       **      B: open temp table

  117693.       **      L: yield X, goto M at EOF

  117694.       **         insert row from R..R+n into temp table

  117695.       **         goto L

  117696.       **      M: ...

  117697.       */

  117698.       int regRec;          /* Register to hold packed record */

  117699.       int regTempRowid;    /* Register to hold temp table ROWID */

  117700.       int addrL;           /* Label "L" */

  117701. 

  117702.       srcTab = pParse->nTab++;

  117703.       regRec = sqlite3GetTempReg(pParse);

  117704.       regTempRowid = sqlite3GetTempReg(pParse);

  117705.       sqlite3VdbeAddOp2(v, OP_OpenEphemeral, srcTab, nColumn);

  117706.       addrL = sqlite3VdbeAddOp1(v, OP_Yield, dest.iSDParm); VdbeCoverage(v);

  117707.       sqlite3VdbeAddOp3(v, OP_MakeRecord, regFromSelect, nColumn, regRec);

  117708.       sqlite3VdbeAddOp2(v, OP_NewRowid, srcTab, regTempRowid);

  117709.       sqlite3VdbeAddOp3(v, OP_Insert, srcTab, regRec, regTempRowid);

  117710.       sqlite3VdbeGoto(v, addrL);

  117711.       sqlite3VdbeJumpHere(v, addrL);

  117712.       sqlite3ReleaseTempReg(pParse, regRec);

  117713.       sqlite3ReleaseTempReg(pParse, regTempRowid);

  117714.     }

  117715.   }else{

  117716.     /* This is the case if the data for the INSERT is coming from a 

  117717.     ** single-row VALUES clause

  117718.     */

  117719.     NameContext sNC;

  117720.     memset(&sNC, 0, sizeof(sNC));

  117721.     sNC.pParse = pParse;

  117722.     srcTab = -1;

  117723.     assert( useTempTable==0 );

  117724.     if( pList ){

  117725.       nColumn = pList->nExpr;

  117726.       if( sqlite3ResolveExprListNames(&sNC, pList) ){

  117727.         goto insert_cleanup;

  117728.       }

  117729.     }else{

  117730.       nColumn = 0;

  117731.     }

  117732.   }

  117733. 

  117734.   /* If there is no IDLIST term but the table has an integer primary

  117735.   ** key, the set the ipkColumn variable to the integer primary key 

  117736.   ** column index in the original table definition.

  117737.   */

  117738.   if( pColumn==0 && nColumn>0 ){

  117739.     ipkColumn = pTab->iPKey;

  117740.   }

  117741. 

  117742.   /* Make sure the number of columns in the source data matches the number

  117743.   ** of columns to be inserted into the table.

  117744.   */

  117745.   for(i=0; i<pTab->nCol; i++){

  117746.     nHidden += (IsHiddenColumn(&pTab->aCol[i]) ? 1 : 0);

  117747.   }

  117748.   if( pColumn==0 && nColumn && nColumn!=(pTab->nCol-nHidden) ){

  117749.     sqlite3ErrorMsg(pParse, 

  117750.        "table %S has %d columns but %d values were supplied",

  117751.        pTabList, 0, pTab->nCol-nHidden, nColumn);

  117752.     goto insert_cleanup;

  117753.   }

  117754.   if( pColumn!=0 && nColumn!=pColumn->nId ){

  117755.     sqlite3ErrorMsg(pParse, "%d values for %d columns", nColumn, pColumn->nId);

  117756.     goto insert_cleanup;

  117757.   }

  117758.     

  117759.   /* Initialize the count of rows to be inserted

  117760.   */

  117761.   if( (db->flags & SQLITE_CountRows)!=0

  117762.    && !pParse->nested

  117763.    && !pParse->pTriggerTab

  117764.   ){

  117765.     regRowCount = ++pParse->nMem;

  117766.     sqlite3VdbeAddOp2(v, OP_Integer, 0, regRowCount);

  117767.   }

  117768. 

  117769.   /* If this is not a view, open the table and and all indices */

  117770.   if( !isView ){

  117771.     int nIdx;

  117772.     nIdx = sqlite3OpenTableAndIndices(pParse, pTab, OP_OpenWrite, 0, -1, 0,

  117773.                                       &iDataCur, &iIdxCur);

  117774.     aRegIdx = sqlite3DbMallocRawNN(db, sizeof(int)*(nIdx+2));

  117775.     if( aRegIdx==0 ){

  117776.       goto insert_cleanup;

  117777.     }

  117778.     for(i=0, pIdx=pTab->pIndex; i<nIdx; pIdx=pIdx->pNext, i++){

  117779.       assert( pIdx );

  117780.       aRegIdx[i] = ++pParse->nMem;

  117781.       pParse->nMem += pIdx->nColumn;

  117782.     }

  117783.     aRegIdx[i] = ++pParse->nMem;  /* Register to store the table record */

  117784.   }

  117785. #ifndef SQLITE_OMIT_UPSERT

  117786.   if( pUpsert ){

  117787.     if( IsVirtual(pTab) ){

  117788.       sqlite3ErrorMsg(pParse, "UPSERT not implemented for virtual table \"%s\"",

  117789.               pTab->zName);

  117790.       goto insert_cleanup;

  117791.     }

  117792.     pTabList->a[0].iCursor = iDataCur;

  117793.     pUpsert->pUpsertSrc = pTabList;

  117794.     pUpsert->regData = regData;

  117795.     pUpsert->iDataCur = iDataCur;

  117796.     pUpsert->iIdxCur = iIdxCur;

  117797.     if( pUpsert->pUpsertTarget ){

  117798.       sqlite3UpsertAnalyzeTarget(pParse, pTabList, pUpsert);

  117799.     }

  117800.   }

  117801. #endif

  117802. 

  117803. 

  117804.   /* This is the top of the main insertion loop */

  117805.   if( useTempTable ){

  117806.     /* This block codes the top of loop only.  The complete loop is the

  117807.     ** following pseudocode (template 4):

  117808.     **

  117809.     **         rewind temp table, if empty goto D

  117810.     **      C: loop over rows of intermediate table

  117811.     **           transfer values form intermediate table into <table>

  117812.     **         end loop

  117813.     **      D: ...

  117814.     */

  117815.     addrInsTop = sqlite3VdbeAddOp1(v, OP_Rewind, srcTab); VdbeCoverage(v);

  117816.     addrCont = sqlite3VdbeCurrentAddr(v);

  117817.   }else if( pSelect ){

  117818.     /* This block codes the top of loop only.  The complete loop is the

  117819.     ** following pseudocode (template 3):

  117820.     **

  117821.     **      C: yield X, at EOF goto D

  117822.     **         insert the select result into <table> from R..R+n

  117823.     **         goto C

  117824.     **      D: ...

  117825.     */

  117826.     addrInsTop = addrCont = sqlite3VdbeAddOp1(v, OP_Yield, dest.iSDParm);

  117827.     VdbeCoverage(v);

  117828.   }

  117829. 

  117830.   /* Run the BEFORE and INSTEAD OF triggers, if there are any

  117831.   */

  117832.   endOfLoop = sqlite3VdbeMakeLabel(pParse);

  117833.   if( tmask & TRIGGER_BEFORE ){

  117834.     int regCols = sqlite3GetTempRange(pParse, pTab->nCol+1);

  117835. 

  117836.     /* build the NEW.* reference row.  Note that if there is an INTEGER

  117837.     ** PRIMARY KEY into which a NULL is being inserted, that NULL will be

  117838.     ** translated into a unique ID for the row.  But on a BEFORE trigger,

  117839.     ** we do not know what the unique ID will be (because the insert has

  117840.     ** not happened yet) so we substitute a rowid of -1

  117841.     */

  117842.     if( ipkColumn<0 ){

  117843.       sqlite3VdbeAddOp2(v, OP_Integer, -1, regCols);

  117844.     }else{

  117845.       int addr1;

  117846.       assert( !withoutRowid );

  117847.       if( useTempTable ){

  117848.         sqlite3VdbeAddOp3(v, OP_Column, srcTab, ipkColumn, regCols);

  117849.       }else{

  117850.         assert( pSelect==0 );  /* Otherwise useTempTable is true */

  117851.         sqlite3ExprCode(pParse, pList->a[ipkColumn].pExpr, regCols);

  117852.       }

  117853.       addr1 = sqlite3VdbeAddOp1(v, OP_NotNull, regCols); VdbeCoverage(v);

  117854.       sqlite3VdbeAddOp2(v, OP_Integer, -1, regCols);

  117855.       sqlite3VdbeJumpHere(v, addr1);

  117856.       sqlite3VdbeAddOp1(v, OP_MustBeInt, regCols); VdbeCoverage(v);

  117857.     }

  117858. 

  117859.     /* Cannot have triggers on a virtual table. If it were possible,

  117860.     ** this block would have to account for hidden column.

  117861.     */

  117862.     assert( !IsVirtual(pTab) );

  117863. 

  117864.     /* Create the new column data

  117865.     */

  117866.     for(i=j=0; i<pTab->nCol; i++){

  117867.       if( pColumn ){

  117868.         for(j=0; j<pColumn->nId; j++){

  117869.           if( pColumn->a[j].idx==i ) break;

  117870.         }

  117871.       }

  117872.       if( (!useTempTable && !pList) || (pColumn && j>=pColumn->nId)

  117873.             || (pColumn==0 && IsOrdinaryHiddenColumn(&pTab->aCol[i])) ){

  117874.         sqlite3ExprCode(pParse, pTab->aCol[i].pDflt, regCols+i+1);

  117875.       }else if( useTempTable ){

  117876.         sqlite3VdbeAddOp3(v, OP_Column, srcTab, j, regCols+i+1); 

  117877.       }else{

  117878.         assert( pSelect==0 ); /* Otherwise useTempTable is true */

  117879.         sqlite3ExprCodeAndCache(pParse, pList->a[j].pExpr, regCols+i+1);

  117880.       }

  117881.       if( pColumn==0 && !IsOrdinaryHiddenColumn(&pTab->aCol[i]) ) j++;

  117882.     }

  117883. 

  117884.     /* If this is an INSERT on a view with an INSTEAD OF INSERT trigger,

  117885.     ** do not attempt any conversions before assembling the record.

  117886.     ** If this is a real table, attempt conversions as required by the

  117887.     ** table column affinities.

  117888.     */

  117889.     if( !isView ){

  117890.       sqlite3TableAffinity(v, pTab, regCols+1);

  117891.     }

  117892. 

  117893.     /* Fire BEFORE or INSTEAD OF triggers */

  117894.     sqlite3CodeRowTrigger(pParse, pTrigger, TK_INSERT, 0, TRIGGER_BEFORE, 

  117895.         pTab, regCols-pTab->nCol-1, onError, endOfLoop);

  117896. 

  117897.     sqlite3ReleaseTempRange(pParse, regCols, pTab->nCol+1);

  117898.   }

  117899. 

  117900.   /* Compute the content of the next row to insert into a range of

  117901.   ** registers beginning at regIns.

  117902.   */

  117903.   if( !isView ){

  117904.     if( IsVirtual(pTab) ){

  117905.       /* The row that the VUpdate opcode will delete: none */

  117906.       sqlite3VdbeAddOp2(v, OP_Null, 0, regIns);

  117907.     }

  117908.     if( ipkColumn>=0 ){

  117909.       if( useTempTable ){

  117910.         sqlite3VdbeAddOp3(v, OP_Column, srcTab, ipkColumn, regRowid);

  117911.       }else if( pSelect ){

  117912.         sqlite3VdbeAddOp2(v, OP_Copy, regFromSelect+ipkColumn, regRowid);

  117913.       }else{

  117914.         Expr *pIpk = pList->a[ipkColumn].pExpr;

  117915.         if( pIpk->op==TK_NULL && !IsVirtual(pTab) ){

  117916.           sqlite3VdbeAddOp3(v, OP_NewRowid, iDataCur, regRowid, regAutoinc);

  117917.           appendFlag = 1;

  117918.         }else{

  117919.           sqlite3ExprCode(pParse, pList->a[ipkColumn].pExpr, regRowid);

  117920.         }

  117921.       }

  117922.       /* If the PRIMARY KEY expression is NULL, then use OP_NewRowid

  117923.       ** to generate a unique primary key value.

  117924.       */

  117925.       if( !appendFlag ){

  117926.         int addr1;

  117927.         if( !IsVirtual(pTab) ){

  117928.           addr1 = sqlite3VdbeAddOp1(v, OP_NotNull, regRowid); VdbeCoverage(v);

  117929.           sqlite3VdbeAddOp3(v, OP_NewRowid, iDataCur, regRowid, regAutoinc);

  117930.           sqlite3VdbeJumpHere(v, addr1);

  117931.         }else{

  117932.           addr1 = sqlite3VdbeCurrentAddr(v);

  117933.           sqlite3VdbeAddOp2(v, OP_IsNull, regRowid, addr1+2); VdbeCoverage(v);

  117934.         }

  117935.         sqlite3VdbeAddOp1(v, OP_MustBeInt, regRowid); VdbeCoverage(v);

  117936.       }

  117937.     }else if( IsVirtual(pTab) || withoutRowid ){

  117938.       sqlite3VdbeAddOp2(v, OP_Null, 0, regRowid);

  117939.     }else{

  117940.       sqlite3VdbeAddOp3(v, OP_NewRowid, iDataCur, regRowid, regAutoinc);

  117941.       appendFlag = 1;

  117942.     }

  117943.     autoIncStep(pParse, regAutoinc, regRowid);

  117944. 

  117945.     /* Compute data for all columns of the new entry, beginning

  117946.     ** with the first column.

  117947.     */

  117948.     nHidden = 0;

  117949.     for(i=0; i<pTab->nCol; i++){

  117950.       int iRegStore = regRowid+1+i;

  117951.       if( i==pTab->iPKey ){

  117952.         /* The value of the INTEGER PRIMARY KEY column is always a NULL.

  117953.         ** Whenever this column is read, the rowid will be substituted

  117954.         ** in its place.  Hence, fill this column with a NULL to avoid

  117955.         ** taking up data space with information that will never be used.

  117956.         ** As there may be shallow copies of this value, make it a soft-NULL */

  117957.         sqlite3VdbeAddOp1(v, OP_SoftNull, iRegStore);

  117958.         continue;

  117959.       }

  117960.       if( pColumn==0 ){

  117961.         if( IsHiddenColumn(&pTab->aCol[i]) ){

  117962.           j = -1;

  117963.           nHidden++;

  117964.         }else{

  117965.           j = i - nHidden;

  117966.         }

  117967.       }else{

  117968.         for(j=0; j<pColumn->nId; j++){

  117969.           if( pColumn->a[j].idx==i ) break;

  117970.         }

  117971.       }

  117972.       if( j<0 || nColumn==0 || (pColumn && j>=pColumn->nId) ){

  117973.         sqlite3ExprCodeFactorable(pParse, pTab->aCol[i].pDflt, iRegStore);

  117974.       }else if( useTempTable ){

  117975.         sqlite3VdbeAddOp3(v, OP_Column, srcTab, j, iRegStore); 

  117976.       }else if( pSelect ){

  117977.         if( regFromSelect!=regData ){

  117978.           sqlite3VdbeAddOp2(v, OP_SCopy, regFromSelect+j, iRegStore);

  117979.         }

  117980.       }else{

  117981.         sqlite3ExprCode(pParse, pList->a[j].pExpr, iRegStore);

  117982.       }

  117983.     }

  117984. 

  117985.     /* Generate code to check constraints and generate index keys and

  117986.     ** do the insertion.

  117987.     */

  117988. #ifndef SQLITE_OMIT_VIRTUALTABLE

  117989.     if( IsVirtual(pTab) ){

  117990.       const char *pVTab = (const char *)sqlite3GetVTable(db, pTab);

  117991.       sqlite3VtabMakeWritable(pParse, pTab);

  117992.       sqlite3VdbeAddOp4(v, OP_VUpdate, 1, pTab->nCol+2, regIns, pVTab, P4_VTAB);

  117993.       sqlite3VdbeChangeP5(v, onError==OE_Default ? OE_Abort : onError);

  117994.       sqlite3MayAbort(pParse);

  117995.     }else

  117996. #endif

  117997.     {

  117998.       int isReplace;    /* Set to true if constraints may cause a replace */

  117999.       int bUseSeek;     /* True to use OPFLAG_SEEKRESULT */

  118000.       sqlite3GenerateConstraintChecks(pParse, pTab, aRegIdx, iDataCur, iIdxCur,

  118001.           regIns, 0, ipkColumn>=0, onError, endOfLoop, &isReplace, 0, pUpsert

  118002.       );

  118003.       sqlite3FkCheck(pParse, pTab, 0, regIns, 0, 0);

  118004. 

  118005.       /* Set the OPFLAG_USESEEKRESULT flag if either (a) there are no REPLACE

  118006.       ** constraints or (b) there are no triggers and this table is not a

  118007.       ** parent table in a foreign key constraint. It is safe to set the

  118008.       ** flag in the second case as if any REPLACE constraint is hit, an

  118009.       ** OP_Delete or OP_IdxDelete instruction will be executed on each 

  118010.       ** cursor that is disturbed. And these instructions both clear the

  118011.       ** VdbeCursor.seekResult variable, disabling the OPFLAG_USESEEKRESULT

  118012.       ** functionality.  */

  118013.       bUseSeek = (isReplace==0 || (pTrigger==0 &&

  118014.           ((db->flags & SQLITE_ForeignKeys)==0 || sqlite3FkReferences(pTab)==0)

  118015.       ));

  118016.       sqlite3CompleteInsertion(pParse, pTab, iDataCur, iIdxCur,

  118017.           regIns, aRegIdx, 0, appendFlag, bUseSeek

  118018.       );

  118019.     }

  118020.   }

  118021. 

  118022.   /* Update the count of rows that are inserted

  118023.   */

  118024.   if( regRowCount ){

  118025.     sqlite3VdbeAddOp2(v, OP_AddImm, regRowCount, 1);

  118026.   }

  118027. 

  118028.   if( pTrigger ){

  118029.     /* Code AFTER triggers */

  118030.     sqlite3CodeRowTrigger(pParse, pTrigger, TK_INSERT, 0, TRIGGER_AFTER, 

  118031.         pTab, regData-2-pTab->nCol, onError, endOfLoop);

  118032.   }

  118033. 

  118034.   /* The bottom of the main insertion loop, if the data source

  118035.   ** is a SELECT statement.

  118036.   */

  118037.   sqlite3VdbeResolveLabel(v, endOfLoop);

  118038.   if( useTempTable ){

  118039.     sqlite3VdbeAddOp2(v, OP_Next, srcTab, addrCont); VdbeCoverage(v);

  118040.     sqlite3VdbeJumpHere(v, addrInsTop);

  118041.     sqlite3VdbeAddOp1(v, OP_Close, srcTab);

  118042.   }else if( pSelect ){

  118043.     sqlite3VdbeGoto(v, addrCont);

  118044.     sqlite3VdbeJumpHere(v, addrInsTop);

  118045.   }

  118046. 

  118047. insert_end:

  118048.   /* Update the sqlite_sequence table by storing the content of the

  118049.   ** maximum rowid counter values recorded while inserting into

  118050.   ** autoincrement tables.

  118051.   */

  118052.   if( pParse->nested==0 && pParse->pTriggerTab==0 ){

  118053.     sqlite3AutoincrementEnd(pParse);

  118054.   }

  118055. 

  118056.   /*

  118057.   ** Return the number of rows inserted. If this routine is 

  118058.   ** generating code because of a call to sqlite3NestedParse(), do not

  118059.   ** invoke the callback function.

  118060.   */

  118061.   if( regRowCount ){

  118062.     sqlite3VdbeAddOp2(v, OP_ResultRow, regRowCount, 1);

  118063.     sqlite3VdbeSetNumCols(v, 1);

  118064.     sqlite3VdbeSetColName(v, 0, COLNAME_NAME, "rows inserted", SQLITE_STATIC);

  118065.   }

  118066. 

  118067. insert_cleanup:

  118068.   sqlite3SrcListDelete(db, pTabList);

  118069.   sqlite3ExprListDelete(db, pList);

  118070.   sqlite3UpsertDelete(db, pUpsert);

  118071.   sqlite3SelectDelete(db, pSelect);

  118072.   sqlite3IdListDelete(db, pColumn);

  118073.   sqlite3DbFree(db, aRegIdx);

  118074. }

  118075. 

  118076. /* Make sure "isView" and other macros defined above are undefined. Otherwise

  118077. ** they may interfere with compilation of other functions in this file

  118078. ** (or in another file, if this file becomes part of the amalgamation).  */

  118079. #ifdef isView

  118080.  #undef isView

  118081. #endif

  118082. #ifdef pTrigger

  118083.  #undef pTrigger

  118084. #endif

  118085. #ifdef tmask

  118086.  #undef tmask

  118087. #endif

  118088. 

  118089. /*

  118090. ** Meanings of bits in of pWalker->eCode for 

  118091. ** sqlite3ExprReferencesUpdatedColumn()

  118092. */

  118093. #define CKCNSTRNT_COLUMN   0x01    /* CHECK constraint uses a changing column */

  118094. #define CKCNSTRNT_ROWID    0x02    /* CHECK constraint references the ROWID */

  118095. 

  118096. /* This is the Walker callback from sqlite3ExprReferencesUpdatedColumn().

  118097. *  Set bit 0x01 of pWalker->eCode if pWalker->eCode to 0 and if this

  118098. ** expression node references any of the

  118099. ** columns that are being modifed by an UPDATE statement.

  118100. */

  118101. static int checkConstraintExprNode(Walker *pWalker, Expr *pExpr){

  118102.   if( pExpr->op==TK_COLUMN ){

  118103.     assert( pExpr->iColumn>=0 || pExpr->iColumn==-1 );

  118104.     if( pExpr->iColumn>=0 ){

  118105.       if( pWalker->u.aiCol[pExpr->iColumn]>=0 ){

  118106.         pWalker->eCode |= CKCNSTRNT_COLUMN;

  118107.       }

  118108.     }else{

  118109.       pWalker->eCode |= CKCNSTRNT_ROWID;

  118110.     }

  118111.   }

  118112.   return WRC_Continue;

  118113. }

  118114. 

  118115. /*

  118116. ** pExpr is a CHECK constraint on a row that is being UPDATE-ed.  The

  118117. ** only columns that are modified by the UPDATE are those for which

  118118. ** aiChng[i]>=0, and also the ROWID is modified if chngRowid is true.

  118119. **

  118120. ** Return true if CHECK constraint pExpr uses any of the

  118121. ** changing columns (or the rowid if it is changing).  In other words,

  118122. ** return true if this CHECK constraint must be validated for

  118123. ** the new row in the UPDATE statement.

  118124. **

  118125. ** 2018-09-15: pExpr might also be an expression for an index-on-expressions.

  118126. ** The operation of this routine is the same - return true if an only if

  118127. ** the expression uses one or more of columns identified by the second and

  118128. ** third arguments.

  118129. */

  118130. SQLITE_PRIVATE int sqlite3ExprReferencesUpdatedColumn(

  118131.   Expr *pExpr,    /* The expression to be checked */

  118132.   int *aiChng,    /* aiChng[x]>=0 if column x changed by the UPDATE */

  118133.   int chngRowid   /* True if UPDATE changes the rowid */

  118134. ){

  118135.   Walker w;

  118136.   memset(&w, 0, sizeof(w));

  118137.   w.eCode = 0;

  118138.   w.xExprCallback = checkConstraintExprNode;

  118139.   w.u.aiCol = aiChng;

  118140.   sqlite3WalkExpr(&w, pExpr);

  118141.   if( !chngRowid ){

  118142.     testcase( (w.eCode & CKCNSTRNT_ROWID)!=0 );

  118143.     w.eCode &= ~CKCNSTRNT_ROWID;

  118144.   }

  118145.   testcase( w.eCode==0 );

  118146.   testcase( w.eCode==CKCNSTRNT_COLUMN );

  118147.   testcase( w.eCode==CKCNSTRNT_ROWID );

  118148.   testcase( w.eCode==(CKCNSTRNT_ROWID|CKCNSTRNT_COLUMN) );

  118149.   return w.eCode!=0;

  118150. }

  118151. 

  118152. /*

  118153. ** Generate code to do constraint checks prior to an INSERT or an UPDATE

  118154. ** on table pTab.

  118155. **

  118156. ** The regNewData parameter is the first register in a range that contains

  118157. ** the data to be inserted or the data after the update.  There will be

  118158. ** pTab->nCol+1 registers in this range.  The first register (the one

  118159. ** that regNewData points to) will contain the new rowid, or NULL in the

  118160. ** case of a WITHOUT ROWID table.  The second register in the range will

  118161. ** contain the content of the first table column.  The third register will

  118162. ** contain the content of the second table column.  And so forth.

  118163. **

  118164. ** The regOldData parameter is similar to regNewData except that it contains

  118165. ** the data prior to an UPDATE rather than afterwards.  regOldData is zero

  118166. ** for an INSERT.  This routine can distinguish between UPDATE and INSERT by

  118167. ** checking regOldData for zero.

  118168. **

  118169. ** For an UPDATE, the pkChng boolean is true if the true primary key (the

  118170. ** rowid for a normal table or the PRIMARY KEY for a WITHOUT ROWID table)

  118171. ** might be modified by the UPDATE.  If pkChng is false, then the key of

  118172. ** the iDataCur content table is guaranteed to be unchanged by the UPDATE.

  118173. **

  118174. ** For an INSERT, the pkChng boolean indicates whether or not the rowid

  118175. ** was explicitly specified as part of the INSERT statement.  If pkChng

  118176. ** is zero, it means that the either rowid is computed automatically or

  118177. ** that the table is a WITHOUT ROWID table and has no rowid.  On an INSERT,

  118178. ** pkChng will only be true if the INSERT statement provides an integer

  118179. ** value for either the rowid column or its INTEGER PRIMARY KEY alias.

  118180. **

  118181. ** The code generated by this routine will store new index entries into

  118182. ** registers identified by aRegIdx[].  No index entry is created for

  118183. ** indices where aRegIdx[i]==0.  The order of indices in aRegIdx[] is

  118184. ** the same as the order of indices on the linked list of indices

  118185. ** at pTab->pIndex.

  118186. **

  118187. ** (2019-05-07) The generated code also creates a new record for the

  118188. ** main table, if pTab is a rowid table, and stores that record in the

  118189. ** register identified by aRegIdx[nIdx] - in other words in the first

  118190. ** entry of aRegIdx[] past the last index.  It is important that the

  118191. ** record be generated during constraint checks to avoid affinity changes

  118192. ** to the register content that occur after constraint checks but before

  118193. ** the new record is inserted.

  118194. **

  118195. ** The caller must have already opened writeable cursors on the main

  118196. ** table and all applicable indices (that is to say, all indices for which

  118197. ** aRegIdx[] is not zero).  iDataCur is the cursor for the main table when

  118198. ** inserting or updating a rowid table, or the cursor for the PRIMARY KEY

  118199. ** index when operating on a WITHOUT ROWID table.  iIdxCur is the cursor

  118200. ** for the first index in the pTab->pIndex list.  Cursors for other indices

  118201. ** are at iIdxCur+N for the N-th element of the pTab->pIndex list.

  118202. **

  118203. ** This routine also generates code to check constraints.  NOT NULL,

  118204. ** CHECK, and UNIQUE constraints are all checked.  If a constraint fails,

  118205. ** then the appropriate action is performed.  There are five possible

  118206. ** actions: ROLLBACK, ABORT, FAIL, REPLACE, and IGNORE.

  118207. **

  118208. **  Constraint type  Action       What Happens

  118209. **  ---------------  ----------   ----------------------------------------

  118210. **  any              ROLLBACK     The current transaction is rolled back and

  118211. **                                sqlite3_step() returns immediately with a

  118212. **                                return code of SQLITE_CONSTRAINT.

  118213. **

  118214. **  any              ABORT        Back out changes from the current command

  118215. **                                only (do not do a complete rollback) then

  118216. **                                cause sqlite3_step() to return immediately

  118217. **                                with SQLITE_CONSTRAINT.

  118218. **

  118219. **  any              FAIL         Sqlite3_step() returns immediately with a

  118220. **                                return code of SQLITE_CONSTRAINT.  The

  118221. **                                transaction is not rolled back and any

  118222. **                                changes to prior rows are retained.

  118223. **

  118224. **  any              IGNORE       The attempt in insert or update the current

  118225. **                                row is skipped, without throwing an error.

  118226. **                                Processing continues with the next row.

  118227. **                                (There is an immediate jump to ignoreDest.)

  118228. **

  118229. **  NOT NULL         REPLACE      The NULL value is replace by the default

  118230. **                                value for that column.  If the default value

  118231. **                                is NULL, the action is the same as ABORT.

  118232. **

  118233. **  UNIQUE           REPLACE      The other row that conflicts with the row

  118234. **                                being inserted is removed.

  118235. **

  118236. **  CHECK            REPLACE      Illegal.  The results in an exception.

  118237. **

  118238. ** Which action to take is determined by the overrideError parameter.

  118239. ** Or if overrideError==OE_Default, then the pParse->onError parameter

  118240. ** is used.  Or if pParse->onError==OE_Default then the onError value

  118241. ** for the constraint is used.

  118242. */

  118243. SQLITE_PRIVATE void sqlite3GenerateConstraintChecks(

  118244.   Parse *pParse,       /* The parser context */

  118245.   Table *pTab,         /* The table being inserted or updated */

  118246.   int *aRegIdx,        /* Use register aRegIdx[i] for index i.  0 for unused */

  118247.   int iDataCur,        /* Canonical data cursor (main table or PK index) */

  118248.   int iIdxCur,         /* First index cursor */

  118249.   int regNewData,      /* First register in a range holding values to insert */

  118250.   int regOldData,      /* Previous content.  0 for INSERTs */

  118251.   u8 pkChng,           /* Non-zero if the rowid or PRIMARY KEY changed */

  118252.   u8 overrideError,    /* Override onError to this if not OE_Default */

  118253.   int ignoreDest,      /* Jump to this label on an OE_Ignore resolution */

  118254.   int *pbMayReplace,   /* OUT: Set to true if constraint may cause a replace */

  118255.   int *aiChng,         /* column i is unchanged if aiChng[i]<0 */

  118256.   Upsert *pUpsert      /* ON CONFLICT clauses, if any.  NULL otherwise */

  118257. ){

  118258.   Vdbe *v;             /* VDBE under constrution */

  118259.   Index *pIdx;         /* Pointer to one of the indices */

  118260.   Index *pPk = 0;      /* The PRIMARY KEY index */

  118261.   sqlite3 *db;         /* Database connection */

  118262.   int i;               /* loop counter */

  118263.   int ix;              /* Index loop counter */

  118264.   int nCol;            /* Number of columns */

  118265.   int onError;         /* Conflict resolution strategy */

  118266.   int addr1;           /* Address of jump instruction */

  118267.   int seenReplace = 0; /* True if REPLACE is used to resolve INT PK conflict */

  118268.   int nPkField;        /* Number of fields in PRIMARY KEY. 1 for ROWID tables */

  118269.   Index *pUpIdx = 0;   /* Index to which to apply the upsert */

  118270.   u8 isUpdate;         /* True if this is an UPDATE operation */

  118271.   u8 bAffinityDone = 0;  /* True if the OP_Affinity operation has been run */

  118272.   int upsertBypass = 0;  /* Address of Goto to bypass upsert subroutine */

  118273.   int upsertJump = 0;    /* Address of Goto that jumps into upsert subroutine */

  118274.   int ipkTop = 0;        /* Top of the IPK uniqueness check */

  118275.   int ipkBottom = 0;     /* OP_Goto at the end of the IPK uniqueness check */

  118276. 

  118277.   isUpdate = regOldData!=0;

  118278.   db = pParse->db;

  118279.   v = sqlite3GetVdbe(pParse);

  118280.   assert( v!=0 );

  118281.   assert( pTab->pSelect==0 );  /* This table is not a VIEW */

  118282.   nCol = pTab->nCol;

  118283.   

  118284.   /* pPk is the PRIMARY KEY index for WITHOUT ROWID tables and NULL for

  118285.   ** normal rowid tables.  nPkField is the number of key fields in the 

  118286.   ** pPk index or 1 for a rowid table.  In other words, nPkField is the

  118287.   ** number of fields in the true primary key of the table. */

  118288.   if( HasRowid(pTab) ){

  118289.     pPk = 0;

  118290.     nPkField = 1;

  118291.   }else{

  118292.     pPk = sqlite3PrimaryKeyIndex(pTab);

  118293.     nPkField = pPk->nKeyCol;

  118294.   }

  118295. 

  118296.   /* Record that this module has started */

  118297.   VdbeModuleComment((v, "BEGIN: GenCnstCks(%d,%d,%d,%d,%d)",

  118298.                      iDataCur, iIdxCur, regNewData, regOldData, pkChng));

  118299. 

  118300.   /* Test all NOT NULL constraints.

  118301.   */

  118302.   for(i=0; i<nCol; i++){

  118303.     if( i==pTab->iPKey ){

  118304.       continue;        /* ROWID is never NULL */

  118305.     }

  118306.     if( aiChng && aiChng[i]<0 ){

  118307.       /* Don't bother checking for NOT NULL on columns that do not change */

  118308.       continue;

  118309.     }

  118310.     onError = pTab->aCol[i].notNull;

  118311.     if( onError==OE_None ) continue;  /* This column is allowed to be NULL */

  118312.     if( overrideError!=OE_Default ){

  118313.       onError = overrideError;

  118314.     }else if( onError==OE_Default ){

  118315.       onError = OE_Abort;

  118316.     }

  118317.     if( onError==OE_Replace && pTab->aCol[i].pDflt==0 ){

  118318.       onError = OE_Abort;

  118319.     }

  118320.     assert( onError==OE_Rollback || onError==OE_Abort || onError==OE_Fail

  118321.         || onError==OE_Ignore || onError==OE_Replace );

  118322.     addr1 = 0;

  118323.     switch( onError ){

  118324.       case OE_Replace: {

  118325.         assert( onError==OE_Replace );

  118326.         addr1 = sqlite3VdbeMakeLabel(pParse);

  118327.         sqlite3VdbeAddOp2(v, OP_NotNull, regNewData+1+i, addr1);

  118328.           VdbeCoverage(v);

  118329.         sqlite3ExprCode(pParse, pTab->aCol[i].pDflt, regNewData+1+i);

  118330.         sqlite3VdbeAddOp2(v, OP_NotNull, regNewData+1+i, addr1);

  118331.           VdbeCoverage(v);

  118332.         onError = OE_Abort;

  118333.         /* Fall through into the OE_Abort case to generate code that runs

  118334.         ** if both the input and the default value are NULL */

  118335.       }

  118336.       case OE_Abort:

  118337.         sqlite3MayAbort(pParse);

  118338.         /* Fall through */

  118339.       case OE_Rollback:

  118340.       case OE_Fail: {

  118341.         char *zMsg = sqlite3MPrintf(db, "%s.%s", pTab->zName,

  118342.                                     pTab->aCol[i].zName);

  118343.         sqlite3VdbeAddOp3(v, OP_HaltIfNull, SQLITE_CONSTRAINT_NOTNULL, onError,

  118344.                           regNewData+1+i);

  118345.         sqlite3VdbeAppendP4(v, zMsg, P4_DYNAMIC);

  118346.         sqlite3VdbeChangeP5(v, P5_ConstraintNotNull);

  118347.         VdbeCoverage(v);

  118348.         if( addr1 ) sqlite3VdbeResolveLabel(v, addr1);

  118349.         break;

  118350.       }

  118351.       default: {

  118352.         assert( onError==OE_Ignore );

  118353.         sqlite3VdbeAddOp2(v, OP_IsNull, regNewData+1+i, ignoreDest);

  118354.         VdbeCoverage(v);

  118355.         break;

  118356.       }

  118357.     }

  118358.   }

  118359. 

  118360.   /* Test all CHECK constraints

  118361.   */

  118362. #ifndef SQLITE_OMIT_CHECK

  118363.   if( pTab->pCheck && (db->flags & SQLITE_IgnoreChecks)==0 ){

  118364.     ExprList *pCheck = pTab->pCheck;

  118365.     pParse->iSelfTab = -(regNewData+1);

  118366.     onError = overrideError!=OE_Default ? overrideError : OE_Abort;

  118367.     for(i=0; i<pCheck->nExpr; i++){

  118368.       int allOk;

  118369.       Expr *pExpr = pCheck->a[i].pExpr;

  118370.       if( aiChng

  118371.        && !sqlite3ExprReferencesUpdatedColumn(pExpr, aiChng, pkChng)

  118372.       ){

  118373.         /* The check constraints do not reference any of the columns being

  118374.         ** updated so there is no point it verifying the check constraint */

  118375.         continue;

  118376.       }

  118377.       allOk = sqlite3VdbeMakeLabel(pParse);

  118378.       sqlite3VdbeVerifyAbortable(v, onError);

  118379.       sqlite3ExprIfTrue(pParse, pExpr, allOk, SQLITE_JUMPIFNULL);

  118380.       if( onError==OE_Ignore ){

  118381.         sqlite3VdbeGoto(v, ignoreDest);

  118382.       }else{

  118383.         char *zName = pCheck->a[i].zName;

  118384.         if( zName==0 ) zName = pTab->zName;

  118385.         if( onError==OE_Replace ) onError = OE_Abort; /* IMP: R-26383-51744 */

  118386.         sqlite3HaltConstraint(pParse, SQLITE_CONSTRAINT_CHECK,

  118387.                               onError, zName, P4_TRANSIENT,

  118388.                               P5_ConstraintCheck);

  118389.       }

  118390.       sqlite3VdbeResolveLabel(v, allOk);

  118391.     }

  118392.     pParse->iSelfTab = 0;

  118393.   }

  118394. #endif /* !defined(SQLITE_OMIT_CHECK) */

  118395. 

  118396.   /* UNIQUE and PRIMARY KEY constraints should be handled in the following

  118397.   ** order:

  118398.   **

  118399.   **   (1)  OE_Update

  118400.   **   (2)  OE_Abort, OE_Fail, OE_Rollback, OE_Ignore

  118401.   **   (3)  OE_Replace

  118402.   **

  118403.   ** OE_Fail and OE_Ignore must happen before any changes are made.

  118404.   ** OE_Update guarantees that only a single row will change, so it

  118405.   ** must happen before OE_Replace.  Technically, OE_Abort and OE_Rollback

  118406.   ** could happen in any order, but they are grouped up front for

  118407.   ** convenience.

  118408.   **

  118409.   ** 2018-08-14: Ticket https://www.sqlite.org/src/info/908f001483982c43

  118410.   ** The order of constraints used to have OE_Update as (2) and OE_Abort

  118411.   ** and so forth as (1). But apparently PostgreSQL checks the OE_Update

  118412.   ** constraint before any others, so it had to be moved.

  118413.   **

  118414.   ** Constraint checking code is generated in this order:

  118415.   **   (A)  The rowid constraint

  118416.   **   (B)  Unique index constraints that do not have OE_Replace as their

  118417.   **        default conflict resolution strategy

  118418.   **   (C)  Unique index that do use OE_Replace by default.

  118419.   **

  118420.   ** The ordering of (2) and (3) is accomplished by making sure the linked

  118421.   ** list of indexes attached to a table puts all OE_Replace indexes last

  118422.   ** in the list.  See sqlite3CreateIndex() for where that happens.

  118423.   */

  118424. 

  118425.   if( pUpsert ){

  118426.     if( pUpsert->pUpsertTarget==0 ){

  118427.       /* An ON CONFLICT DO NOTHING clause, without a constraint-target.

  118428.       ** Make all unique constraint resolution be OE_Ignore */

  118429.       assert( pUpsert->pUpsertSet==0 );

  118430.       overrideError = OE_Ignore;

  118431.       pUpsert = 0;

  118432.     }else if( (pUpIdx = pUpsert->pUpsertIdx)!=0 ){

  118433.       /* If the constraint-target uniqueness check must be run first.

  118434.       ** Jump to that uniqueness check now */

  118435.       upsertJump = sqlite3VdbeAddOp0(v, OP_Goto);

  118436.       VdbeComment((v, "UPSERT constraint goes first"));

  118437.     }

  118438.   }

  118439. 

  118440.   /* If rowid is changing, make sure the new rowid does not previously

  118441.   ** exist in the table.

  118442.   */

  118443.   if( pkChng && pPk==0 ){

  118444.     int addrRowidOk = sqlite3VdbeMakeLabel(pParse);

  118445. 

  118446.     /* Figure out what action to take in case of a rowid collision */

  118447.     onError = pTab->keyConf;

  118448.     if( overrideError!=OE_Default ){

  118449.       onError = overrideError;

  118450.     }else if( onError==OE_Default ){

  118451.       onError = OE_Abort;

  118452.     }

  118453. 

  118454.     /* figure out whether or not upsert applies in this case */

  118455.     if( pUpsert && pUpsert->pUpsertIdx==0 ){

  118456.       if( pUpsert->pUpsertSet==0 ){

  118457.         onError = OE_Ignore;  /* DO NOTHING is the same as INSERT OR IGNORE */

  118458.       }else{

  118459.         onError = OE_Update;  /* DO UPDATE */

  118460.       }

  118461.     }

  118462. 

  118463.     /* If the response to a rowid conflict is REPLACE but the response

  118464.     ** to some other UNIQUE constraint is FAIL or IGNORE, then we need

  118465.     ** to defer the running of the rowid conflict checking until after

  118466.     ** the UNIQUE constraints have run.

  118467.     */

  118468.     if( onError==OE_Replace      /* IPK rule is REPLACE */

  118469.      && onError!=overrideError   /* Rules for other contraints are different */

  118470.      && pTab->pIndex             /* There exist other constraints */

  118471.     ){

  118472.       ipkTop = sqlite3VdbeAddOp0(v, OP_Goto)+1;

  118473.       VdbeComment((v, "defer IPK REPLACE until last"));

  118474.     }

  118475. 

  118476.     if( isUpdate ){

  118477.       /* pkChng!=0 does not mean that the rowid has changed, only that

  118478.       ** it might have changed.  Skip the conflict logic below if the rowid

  118479.       ** is unchanged. */

  118480.       sqlite3VdbeAddOp3(v, OP_Eq, regNewData, addrRowidOk, regOldData);

  118481.       sqlite3VdbeChangeP5(v, SQLITE_NOTNULL);

  118482.       VdbeCoverage(v);

  118483.     }

  118484. 

  118485.     /* Check to see if the new rowid already exists in the table.  Skip

  118486.     ** the following conflict logic if it does not. */

  118487.     VdbeNoopComment((v, "uniqueness check for ROWID"));

  118488.     sqlite3VdbeVerifyAbortable(v, onError);

  118489.     sqlite3VdbeAddOp3(v, OP_NotExists, iDataCur, addrRowidOk, regNewData);

  118490.     VdbeCoverage(v);

  118491. 

  118492.     switch( onError ){

  118493.       default: {

  118494.         onError = OE_Abort;

  118495.         /* Fall thru into the next case */

  118496.       }

  118497.       case OE_Rollback:

  118498.       case OE_Abort:

  118499.       case OE_Fail: {

  118500.         testcase( onError==OE_Rollback );

  118501.         testcase( onError==OE_Abort );

  118502.         testcase( onError==OE_Fail );

  118503.         sqlite3RowidConstraint(pParse, onError, pTab);

  118504.         break;

  118505.       }

  118506.       case OE_Replace: {

  118507.         /* If there are DELETE triggers on this table and the

  118508.         ** recursive-triggers flag is set, call GenerateRowDelete() to

  118509.         ** remove the conflicting row from the table. This will fire

  118510.         ** the triggers and remove both the table and index b-tree entries.

  118511.         **

  118512.         ** Otherwise, if there are no triggers or the recursive-triggers

  118513.         ** flag is not set, but the table has one or more indexes, call 

  118514.         ** GenerateRowIndexDelete(). This removes the index b-tree entries 

  118515.         ** only. The table b-tree entry will be replaced by the new entry 

  118516.         ** when it is inserted.  

  118517.         **

  118518.         ** If either GenerateRowDelete() or GenerateRowIndexDelete() is called,

  118519.         ** also invoke MultiWrite() to indicate that this VDBE may require

  118520.         ** statement rollback (if the statement is aborted after the delete

  118521.         ** takes place). Earlier versions called sqlite3MultiWrite() regardless,

  118522.         ** but being more selective here allows statements like:

  118523.         **

  118524.         **   REPLACE INTO t(rowid) VALUES($newrowid)

  118525.         **

  118526.         ** to run without a statement journal if there are no indexes on the

  118527.         ** table.

  118528.         */

  118529.         Trigger *pTrigger = 0;

  118530.         if( db->flags&SQLITE_RecTriggers ){

  118531.           pTrigger = sqlite3TriggersExist(pParse, pTab, TK_DELETE, 0, 0);

  118532.         }

  118533.         if( pTrigger || sqlite3FkRequired(pParse, pTab, 0, 0) ){

  118534.           sqlite3MultiWrite(pParse);

  118535.           sqlite3GenerateRowDelete(pParse, pTab, pTrigger, iDataCur, iIdxCur,

  118536.                                    regNewData, 1, 0, OE_Replace, 1, -1);

  118537.         }else{

  118538. #ifdef SQLITE_ENABLE_PREUPDATE_HOOK

  118539.           assert( HasRowid(pTab) );

  118540.           /* This OP_Delete opcode fires the pre-update-hook only. It does

  118541.           ** not modify the b-tree. It is more efficient to let the coming

  118542.           ** OP_Insert replace the existing entry than it is to delete the

  118543.           ** existing entry and then insert a new one. */

  118544.           sqlite3VdbeAddOp2(v, OP_Delete, iDataCur, OPFLAG_ISNOOP);

  118545.           sqlite3VdbeAppendP4(v, pTab, P4_TABLE);

  118546. #endif /* SQLITE_ENABLE_PREUPDATE_HOOK */

  118547.           if( pTab->pIndex ){

  118548.             sqlite3MultiWrite(pParse);

  118549.             sqlite3GenerateRowIndexDelete(pParse, pTab, iDataCur, iIdxCur,0,-1);

  118550.           }

  118551.         }

  118552.         seenReplace = 1;

  118553.         break;

  118554.       }

  118555. #ifndef SQLITE_OMIT_UPSERT

  118556.       case OE_Update: {

  118557.         sqlite3UpsertDoUpdate(pParse, pUpsert, pTab, 0, iDataCur);

  118558.         /* Fall through */

  118559.       }

  118560. #endif

  118561.       case OE_Ignore: {

  118562.         testcase( onError==OE_Ignore );

  118563.         sqlite3VdbeGoto(v, ignoreDest);

  118564.         break;

  118565.       }

  118566.     }

  118567.     sqlite3VdbeResolveLabel(v, addrRowidOk);

  118568.     if( ipkTop ){

  118569.       ipkBottom = sqlite3VdbeAddOp0(v, OP_Goto);

  118570.       sqlite3VdbeJumpHere(v, ipkTop-1);

  118571.     }

  118572.   }

  118573. 

  118574.   /* Test all UNIQUE constraints by creating entries for each UNIQUE

  118575.   ** index and making sure that duplicate entries do not already exist.

  118576.   ** Compute the revised record entries for indices as we go.

  118577.   **

  118578.   ** This loop also handles the case of the PRIMARY KEY index for a

  118579.   ** WITHOUT ROWID table.

  118580.   */

  118581.   for(ix=0, pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext, ix++){

  118582.     int regIdx;          /* Range of registers hold conent for pIdx */

  118583.     int regR;            /* Range of registers holding conflicting PK */

  118584.     int iThisCur;        /* Cursor for this UNIQUE index */

  118585.     int addrUniqueOk;    /* Jump here if the UNIQUE constraint is satisfied */

  118586. 

  118587.     if( aRegIdx[ix]==0 ) continue;  /* Skip indices that do not change */

  118588.     if( pUpIdx==pIdx ){

  118589.       addrUniqueOk = upsertJump+1;

  118590.       upsertBypass = sqlite3VdbeGoto(v, 0);

  118591.       VdbeComment((v, "Skip upsert subroutine"));

  118592.       sqlite3VdbeJumpHere(v, upsertJump);

  118593.     }else{

  118594.       addrUniqueOk = sqlite3VdbeMakeLabel(pParse);

  118595.     }

  118596.     if( bAffinityDone==0 && (pUpIdx==0 || pUpIdx==pIdx) ){

  118597.       sqlite3TableAffinity(v, pTab, regNewData+1);

  118598.       bAffinityDone = 1;

  118599.     }

  118600.     VdbeNoopComment((v, "uniqueness check for %s", pIdx->zName));

  118601.     iThisCur = iIdxCur+ix;

  118602. 

  118603. 

  118604.     /* Skip partial indices for which the WHERE clause is not true */

  118605.     if( pIdx->pPartIdxWhere ){

  118606.       sqlite3VdbeAddOp2(v, OP_Null, 0, aRegIdx[ix]);

  118607.       pParse->iSelfTab = -(regNewData+1);

  118608.       sqlite3ExprIfFalseDup(pParse, pIdx->pPartIdxWhere, addrUniqueOk,

  118609.                             SQLITE_JUMPIFNULL);

  118610.       pParse->iSelfTab = 0;

  118611.     }

  118612. 

  118613.     /* Create a record for this index entry as it should appear after

  118614.     ** the insert or update.  Store that record in the aRegIdx[ix] register

  118615.     */

  118616.     regIdx = aRegIdx[ix]+1;

  118617.     for(i=0; i<pIdx->nColumn; i++){

  118618.       int iField = pIdx->aiColumn[i];

  118619.       int x;

  118620.       if( iField==XN_EXPR ){

  118621.         pParse->iSelfTab = -(regNewData+1);

  118622.         sqlite3ExprCodeCopy(pParse, pIdx->aColExpr->a[i].pExpr, regIdx+i);

  118623.         pParse->iSelfTab = 0;

  118624.         VdbeComment((v, "%s column %d", pIdx->zName, i));

  118625.       }else{

  118626.         if( iField==XN_ROWID || iField==pTab->iPKey ){

  118627.           x = regNewData;

  118628.         }else{

  118629.           x = iField + regNewData + 1;

  118630.         }

  118631.         sqlite3VdbeAddOp2(v, iField<0 ? OP_IntCopy : OP_SCopy, x, regIdx+i);

  118632.         VdbeComment((v, "%s", iField<0 ? "rowid" : pTab->aCol[iField].zName));

  118633.       }

  118634.     }

  118635.     sqlite3VdbeAddOp3(v, OP_MakeRecord, regIdx, pIdx->nColumn, aRegIdx[ix]);

  118636.     VdbeComment((v, "for %s", pIdx->zName));

  118637. #ifdef SQLITE_ENABLE_NULL_TRIM

  118638.     if( pIdx->idxType==SQLITE_IDXTYPE_PRIMARYKEY ){

  118639.       sqlite3SetMakeRecordP5(v, pIdx->pTable);

  118640.     }

  118641. #endif

  118642. 

  118643.     /* In an UPDATE operation, if this index is the PRIMARY KEY index 

  118644.     ** of a WITHOUT ROWID table and there has been no change the

  118645.     ** primary key, then no collision is possible.  The collision detection

  118646.     ** logic below can all be skipped. */

  118647.     if( isUpdate && pPk==pIdx && pkChng==0 ){

  118648.       sqlite3VdbeResolveLabel(v, addrUniqueOk);

  118649.       continue;

  118650.     }

  118651. 

  118652.     /* Find out what action to take in case there is a uniqueness conflict */

  118653.     onError = pIdx->onError;

  118654.     if( onError==OE_None ){ 

  118655.       sqlite3VdbeResolveLabel(v, addrUniqueOk);

  118656.       continue;  /* pIdx is not a UNIQUE index */

  118657.     }

  118658.     if( overrideError!=OE_Default ){

  118659.       onError = overrideError;

  118660.     }else if( onError==OE_Default ){

  118661.       onError = OE_Abort;

  118662.     }

  118663. 

  118664.     /* Figure out if the upsert clause applies to this index */

  118665.     if( pUpIdx==pIdx ){

  118666.       if( pUpsert->pUpsertSet==0 ){

  118667.         onError = OE_Ignore;  /* DO NOTHING is the same as INSERT OR IGNORE */

  118668.       }else{

  118669.         onError = OE_Update;  /* DO UPDATE */

  118670.       }

  118671.     }

  118672. 

  118673.     /* Collision detection may be omitted if all of the following are true:

  118674.     **   (1) The conflict resolution algorithm is REPLACE

  118675.     **   (2) The table is a WITHOUT ROWID table

  118676.     **   (3) There are no secondary indexes on the table

  118677.     **   (4) No delete triggers need to be fired if there is a conflict

  118678.     **   (5) No FK constraint counters need to be updated if a conflict occurs.

  118679.     **

  118680.     ** This is not possible for ENABLE_PREUPDATE_HOOK builds, as the row

  118681.     ** must be explicitly deleted in order to ensure any pre-update hook

  118682.     ** is invoked.  */ 

  118683. #ifndef SQLITE_ENABLE_PREUPDATE_HOOK

  118684.     if( (ix==0 && pIdx->pNext==0)                   /* Condition 3 */

  118685.      && pPk==pIdx                                   /* Condition 2 */

  118686.      && onError==OE_Replace                         /* Condition 1 */

  118687.      && ( 0==(db->flags&SQLITE_RecTriggers) ||      /* Condition 4 */

  118688.           0==sqlite3TriggersExist(pParse, pTab, TK_DELETE, 0, 0))

  118689.      && ( 0==(db->flags&SQLITE_ForeignKeys) ||      /* Condition 5 */

  118690.          (0==pTab->pFKey && 0==sqlite3FkReferences(pTab)))

  118691.     ){

  118692.       sqlite3VdbeResolveLabel(v, addrUniqueOk);

  118693.       continue;

  118694.     }

  118695. #endif /* ifndef SQLITE_ENABLE_PREUPDATE_HOOK */

  118696. 

  118697.     /* Check to see if the new index entry will be unique */

  118698.     sqlite3VdbeVerifyAbortable(v, onError);

  118699.     sqlite3VdbeAddOp4Int(v, OP_NoConflict, iThisCur, addrUniqueOk,

  118700.                          regIdx, pIdx->nKeyCol); VdbeCoverage(v);

  118701. 

  118702.     /* Generate code to handle collisions */

  118703.     regR = (pIdx==pPk) ? regIdx : sqlite3GetTempRange(pParse, nPkField);

  118704.     if( isUpdate || onError==OE_Replace ){

  118705.       if( HasRowid(pTab) ){

  118706.         sqlite3VdbeAddOp2(v, OP_IdxRowid, iThisCur, regR);

  118707.         /* Conflict only if the rowid of the existing index entry

  118708.         ** is different from old-rowid */

  118709.         if( isUpdate ){

  118710.           sqlite3VdbeAddOp3(v, OP_Eq, regR, addrUniqueOk, regOldData);

  118711.           sqlite3VdbeChangeP5(v, SQLITE_NOTNULL);

  118712.           VdbeCoverage(v);

  118713.         }

  118714.       }else{

  118715.         int x;

  118716.         /* Extract the PRIMARY KEY from the end of the index entry and

  118717.         ** store it in registers regR..regR+nPk-1 */

  118718.         if( pIdx!=pPk ){

  118719.           for(i=0; i<pPk->nKeyCol; i++){

  118720.             assert( pPk->aiColumn[i]>=0 );

  118721.             x = sqlite3ColumnOfIndex(pIdx, pPk->aiColumn[i]);

  118722.             sqlite3VdbeAddOp3(v, OP_Column, iThisCur, x, regR+i);

  118723.             VdbeComment((v, "%s.%s", pTab->zName,

  118724.                          pTab->aCol[pPk->aiColumn[i]].zName));

  118725.           }

  118726.         }

  118727.         if( isUpdate ){

  118728.           /* If currently processing the PRIMARY KEY of a WITHOUT ROWID 

  118729.           ** table, only conflict if the new PRIMARY KEY values are actually

  118730.           ** different from the old.

  118731.           **

  118732.           ** For a UNIQUE index, only conflict if the PRIMARY KEY values

  118733.           ** of the matched index row are different from the original PRIMARY

  118734.           ** KEY values of this row before the update.  */

  118735.           int addrJump = sqlite3VdbeCurrentAddr(v)+pPk->nKeyCol;

  118736.           int op = OP_Ne;

  118737.           int regCmp = (IsPrimaryKeyIndex(pIdx) ? regIdx : regR);

  118738.   

  118739.           for(i=0; i<pPk->nKeyCol; i++){

  118740.             char *p4 = (char*)sqlite3LocateCollSeq(pParse, pPk->azColl[i]);

  118741.             x = pPk->aiColumn[i];

  118742.             assert( x>=0 );

  118743.             if( i==(pPk->nKeyCol-1) ){

  118744.               addrJump = addrUniqueOk;

  118745.               op = OP_Eq;

  118746.             }

  118747.             sqlite3VdbeAddOp4(v, op, 

  118748.                 regOldData+1+x, addrJump, regCmp+i, p4, P4_COLLSEQ

  118749.             );

  118750.             sqlite3VdbeChangeP5(v, SQLITE_NOTNULL);

  118751.             VdbeCoverageIf(v, op==OP_Eq);

  118752.             VdbeCoverageIf(v, op==OP_Ne);

  118753.           }

  118754.         }

  118755.       }

  118756.     }

  118757. 

  118758.     /* Generate code that executes if the new index entry is not unique */

  118759.     assert( onError==OE_Rollback || onError==OE_Abort || onError==OE_Fail

  118760.         || onError==OE_Ignore || onError==OE_Replace || onError==OE_Update );

  118761.     switch( onError ){

  118762.       case OE_Rollback:

  118763.       case OE_Abort:

  118764.       case OE_Fail: {

  118765.         testcase( onError==OE_Rollback );

  118766.         testcase( onError==OE_Abort );

  118767.         testcase( onError==OE_Fail );

  118768.         sqlite3UniqueConstraint(pParse, onError, pIdx);

  118769.         break;

  118770.       }

  118771. #ifndef SQLITE_OMIT_UPSERT

  118772.       case OE_Update: {

  118773.         sqlite3UpsertDoUpdate(pParse, pUpsert, pTab, pIdx, iIdxCur+ix);

  118774.         /* Fall through */

  118775.       }

  118776. #endif

  118777.       case OE_Ignore: {

  118778.         testcase( onError==OE_Ignore );

  118779.         sqlite3VdbeGoto(v, ignoreDest);

  118780.         break;

  118781.       }

  118782.       default: {

  118783.         Trigger *pTrigger = 0;

  118784.         assert( onError==OE_Replace );

  118785.         if( db->flags&SQLITE_RecTriggers ){

  118786.           pTrigger = sqlite3TriggersExist(pParse, pTab, TK_DELETE, 0, 0);

  118787.         }

  118788.         if( pTrigger || sqlite3FkRequired(pParse, pTab, 0, 0) ){

  118789.           sqlite3MultiWrite(pParse);

  118790.         }

  118791.         sqlite3GenerateRowDelete(pParse, pTab, pTrigger, iDataCur, iIdxCur,

  118792.             regR, nPkField, 0, OE_Replace,

  118793.             (pIdx==pPk ? ONEPASS_SINGLE : ONEPASS_OFF), iThisCur);

  118794.         seenReplace = 1;

  118795.         break;

  118796.       }

  118797.     }

  118798.     if( pUpIdx==pIdx ){

  118799.       sqlite3VdbeGoto(v, upsertJump+1);

  118800.       sqlite3VdbeJumpHere(v, upsertBypass);

  118801.     }else{

  118802.       sqlite3VdbeResolveLabel(v, addrUniqueOk);

  118803.     }

  118804.     if( regR!=regIdx ) sqlite3ReleaseTempRange(pParse, regR, nPkField);

  118805.   }

  118806. 

  118807.   /* If the IPK constraint is a REPLACE, run it last */

  118808.   if( ipkTop ){

  118809.     sqlite3VdbeGoto(v, ipkTop);

  118810.     VdbeComment((v, "Do IPK REPLACE"));

  118811.     sqlite3VdbeJumpHere(v, ipkBottom);

  118812.   }

  118813. 

  118814.   /* Generate the table record */

  118815.   if( HasRowid(pTab) ){

  118816.     int regRec = aRegIdx[ix];

  118817.     sqlite3VdbeAddOp3(v, OP_MakeRecord, regNewData+1, pTab->nCol, regRec);

  118818.     sqlite3SetMakeRecordP5(v, pTab);

  118819.     if( !bAffinityDone ){

  118820.       sqlite3TableAffinity(v, pTab, 0);

  118821.     }

  118822.   }

  118823. 

  118824.   *pbMayReplace = seenReplace;

  118825.   VdbeModuleComment((v, "END: GenCnstCks(%d)", seenReplace));

  118826. }

  118827. 

  118828. #ifdef SQLITE_ENABLE_NULL_TRIM

  118829. /*

  118830. ** Change the P5 operand on the last opcode (which should be an OP_MakeRecord)

  118831. ** to be the number of columns in table pTab that must not be NULL-trimmed.

  118832. **

  118833. ** Or if no columns of pTab may be NULL-trimmed, leave P5 at zero.

  118834. */

  118835. SQLITE_PRIVATE void sqlite3SetMakeRecordP5(Vdbe *v, Table *pTab){

  118836.   u16 i;

  118837. 

  118838.   /* Records with omitted columns are only allowed for schema format

  118839.   ** version 2 and later (SQLite version 3.1.4, 2005-02-20). */

  118840.   if( pTab->pSchema->file_format<2 ) return;

  118841. 

  118842.   for(i=pTab->nCol-1; i>0; i--){

  118843.     if( pTab->aCol[i].pDflt!=0 ) break;

  118844.     if( pTab->aCol[i].colFlags & COLFLAG_PRIMKEY ) break;

  118845.   }

  118846.   sqlite3VdbeChangeP5(v, i+1);

  118847. }

  118848. #endif

  118849. 

  118850. /*

  118851. ** This routine generates code to finish the INSERT or UPDATE operation

  118852. ** that was started by a prior call to sqlite3GenerateConstraintChecks.

  118853. ** A consecutive range of registers starting at regNewData contains the

  118854. ** rowid and the content to be inserted.

  118855. **

  118856. ** The arguments to this routine should be the same as the first six

  118857. ** arguments to sqlite3GenerateConstraintChecks.

  118858. */

  118859. SQLITE_PRIVATE void sqlite3CompleteInsertion(

  118860.   Parse *pParse,      /* The parser context */

  118861.   Table *pTab,        /* the table into which we are inserting */

  118862.   int iDataCur,       /* Cursor of the canonical data source */

  118863.   int iIdxCur,        /* First index cursor */

  118864.   int regNewData,     /* Range of content */

  118865.   int *aRegIdx,       /* Register used by each index.  0 for unused indices */

  118866.   int update_flags,   /* True for UPDATE, False for INSERT */

  118867.   int appendBias,     /* True if this is likely to be an append */

  118868.   int useSeekResult   /* True to set the USESEEKRESULT flag on OP_[Idx]Insert */

  118869. ){

  118870.   Vdbe *v;            /* Prepared statements under construction */

  118871.   Index *pIdx;        /* An index being inserted or updated */

  118872.   u8 pik_flags;       /* flag values passed to the btree insert */

  118873.   int i;              /* Loop counter */

  118874. 

  118875.   assert( update_flags==0

  118876.        || update_flags==OPFLAG_ISUPDATE

  118877.        || update_flags==(OPFLAG_ISUPDATE|OPFLAG_SAVEPOSITION)

  118878.   );

  118879. 

  118880.   v = sqlite3GetVdbe(pParse);

  118881.   assert( v!=0 );

  118882.   assert( pTab->pSelect==0 );  /* This table is not a VIEW */

  118883.   for(i=0, pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext, i++){

  118884.     if( aRegIdx[i]==0 ) continue;

  118885.     if( pIdx->pPartIdxWhere ){

  118886.       sqlite3VdbeAddOp2(v, OP_IsNull, aRegIdx[i], sqlite3VdbeCurrentAddr(v)+2);

  118887.       VdbeCoverage(v);

  118888.     }

  118889.     pik_flags = (useSeekResult ? OPFLAG_USESEEKRESULT : 0);

  118890.     if( IsPrimaryKeyIndex(pIdx) && !HasRowid(pTab) ){

  118891.       assert( pParse->nested==0 );

  118892.       pik_flags |= OPFLAG_NCHANGE;

  118893.       pik_flags |= (update_flags & OPFLAG_SAVEPOSITION);

  118894. #ifdef SQLITE_ENABLE_PREUPDATE_HOOK

  118895.       if( update_flags==0 ){

  118896.         int r = sqlite3GetTempReg(pParse);

  118897.         sqlite3VdbeAddOp2(v, OP_Integer, 0, r);

  118898.         sqlite3VdbeAddOp4(v, OP_Insert, 

  118899.             iIdxCur+i, aRegIdx[i], r, (char*)pTab, P4_TABLE

  118900.         );

  118901.         sqlite3VdbeChangeP5(v, OPFLAG_ISNOOP);

  118902.         sqlite3ReleaseTempReg(pParse, r);

  118903.       }

  118904. #endif

  118905.     }

  118906.     sqlite3VdbeAddOp4Int(v, OP_IdxInsert, iIdxCur+i, aRegIdx[i],

  118907.                          aRegIdx[i]+1,

  118908.                          pIdx->uniqNotNull ? pIdx->nKeyCol: pIdx->nColumn);

  118909.     sqlite3VdbeChangeP5(v, pik_flags);

  118910.   }

  118911.   if( !HasRowid(pTab) ) return;

  118912.   if( pParse->nested ){

  118913.     pik_flags = 0;

  118914.   }else{

  118915.     pik_flags = OPFLAG_NCHANGE;

  118916.     pik_flags |= (update_flags?update_flags:OPFLAG_LASTROWID);

  118917.   }

  118918.   if( appendBias ){

  118919.     pik_flags |= OPFLAG_APPEND;

  118920.   }

  118921.   if( useSeekResult ){

  118922.     pik_flags |= OPFLAG_USESEEKRESULT;

  118923.   }

  118924.   sqlite3VdbeAddOp3(v, OP_Insert, iDataCur, aRegIdx[i], regNewData);

  118925.   if( !pParse->nested ){

  118926.     sqlite3VdbeAppendP4(v, pTab, P4_TABLE);

  118927.   }

  118928.   sqlite3VdbeChangeP5(v, pik_flags);

  118929. }

  118930. 

  118931. /*

  118932. ** Allocate cursors for the pTab table and all its indices and generate

  118933. ** code to open and initialized those cursors.

  118934. **

  118935. ** The cursor for the object that contains the complete data (normally

  118936. ** the table itself, but the PRIMARY KEY index in the case of a WITHOUT

  118937. ** ROWID table) is returned in *piDataCur.  The first index cursor is

  118938. ** returned in *piIdxCur.  The number of indices is returned.

  118939. **

  118940. ** Use iBase as the first cursor (either the *piDataCur for rowid tables

  118941. ** or the first index for WITHOUT ROWID tables) if it is non-negative.

  118942. ** If iBase is negative, then allocate the next available cursor.

  118943. **

  118944. ** For a rowid table, *piDataCur will be exactly one less than *piIdxCur.

  118945. ** For a WITHOUT ROWID table, *piDataCur will be somewhere in the range

  118946. ** of *piIdxCurs, depending on where the PRIMARY KEY index appears on the

  118947. ** pTab->pIndex list.

  118948. **

  118949. ** If pTab is a virtual table, then this routine is a no-op and the

  118950. ** *piDataCur and *piIdxCur values are left uninitialized.

  118951. */

  118952. SQLITE_PRIVATE int sqlite3OpenTableAndIndices(

  118953.   Parse *pParse,   /* Parsing context */

  118954.   Table *pTab,     /* Table to be opened */

  118955.   int op,          /* OP_OpenRead or OP_OpenWrite */

  118956.   u8 p5,           /* P5 value for OP_Open* opcodes (except on WITHOUT ROWID) */

  118957.   int iBase,       /* Use this for the table cursor, if there is one */

  118958.   u8 *aToOpen,     /* If not NULL: boolean for each table and index */

  118959.   int *piDataCur,  /* Write the database source cursor number here */

  118960.   int *piIdxCur    /* Write the first index cursor number here */

  118961. ){

  118962.   int i;

  118963.   int iDb;

  118964.   int iDataCur;

  118965.   Index *pIdx;

  118966.   Vdbe *v;

  118967. 

  118968.   assert( op==OP_OpenRead || op==OP_OpenWrite );

  118969.   assert( op==OP_OpenWrite || p5==0 );

  118970.   if( IsVirtual(pTab) ){

  118971.     /* This routine is a no-op for virtual tables. Leave the output

  118972.     ** variables *piDataCur and *piIdxCur uninitialized so that valgrind

  118973.     ** can detect if they are used by mistake in the caller. */

  118974.     return 0;

  118975.   }

  118976.   iDb = sqlite3SchemaToIndex(pParse->db, pTab->pSchema);

  118977.   v = sqlite3GetVdbe(pParse);

  118978.   assert( v!=0 );

  118979.   if( iBase<0 ) iBase = pParse->nTab;

  118980.   iDataCur = iBase++;

  118981.   if( piDataCur ) *piDataCur = iDataCur;

  118982.   if( HasRowid(pTab) && (aToOpen==0 || aToOpen[0]) ){

  118983.     sqlite3OpenTable(pParse, iDataCur, iDb, pTab, op);

  118984.   }else{

  118985.     sqlite3TableLock(pParse, iDb, pTab->tnum, op==OP_OpenWrite, pTab->zName);

  118986.   }

  118987.   if( piIdxCur ) *piIdxCur = iBase;

  118988.   for(i=0, pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext, i++){

  118989.     int iIdxCur = iBase++;

  118990.     assert( pIdx->pSchema==pTab->pSchema );

  118991.     if( IsPrimaryKeyIndex(pIdx) && !HasRowid(pTab) ){

  118992.       if( piDataCur ) *piDataCur = iIdxCur;

  118993.       p5 = 0;

  118994.     }

  118995.     if( aToOpen==0 || aToOpen[i+1] ){

  118996.       sqlite3VdbeAddOp3(v, op, iIdxCur, pIdx->tnum, iDb);

  118997.       sqlite3VdbeSetP4KeyInfo(pParse, pIdx);

  118998.       sqlite3VdbeChangeP5(v, p5);

  118999.       VdbeComment((v, "%s", pIdx->zName));

  119000.     }

  119001.   }

  119002.   if( iBase>pParse->nTab ) pParse->nTab = iBase;

  119003.   return i;

  119004. }

  119005. 

  119006. 

  119007. #ifdef SQLITE_TEST

  119008. /*

  119009. ** The following global variable is incremented whenever the

  119010. ** transfer optimization is used.  This is used for testing

  119011. ** purposes only - to make sure the transfer optimization really

  119012. ** is happening when it is supposed to.

  119013. */

  119014. SQLITE_API int sqlite3_xferopt_count;

  119015. #endif /* SQLITE_TEST */

  119016. 

  119017. 

  119018. #ifndef SQLITE_OMIT_XFER_OPT

  119019. /*

  119020. ** Check to see if index pSrc is compatible as a source of data

  119021. ** for index pDest in an insert transfer optimization.  The rules

  119022. ** for a compatible index:

  119023. **

  119024. **    *   The index is over the same set of columns

  119025. **    *   The same DESC and ASC markings occurs on all columns

  119026. **    *   The same onError processing (OE_Abort, OE_Ignore, etc)

  119027. **    *   The same collating sequence on each column

  119028. **    *   The index has the exact same WHERE clause

  119029. */

  119030. static int xferCompatibleIndex(Index *pDest, Index *pSrc){

  119031.   int i;

  119032.   assert( pDest && pSrc );

  119033.   assert( pDest->pTable!=pSrc->pTable );

  119034.   if( pDest->nKeyCol!=pSrc->nKeyCol ){

  119035.     return 0;   /* Different number of columns */

  119036.   }

  119037.   if( pDest->onError!=pSrc->onError ){

  119038.     return 0;   /* Different conflict resolution strategies */

  119039.   }

  119040.   for(i=0; i<pSrc->nKeyCol; i++){

  119041.     if( pSrc->aiColumn[i]!=pDest->aiColumn[i] ){

  119042.       return 0;   /* Different columns indexed */

  119043.     }

  119044.     if( pSrc->aiColumn[i]==XN_EXPR ){

  119045.       assert( pSrc->aColExpr!=0 && pDest->aColExpr!=0 );

  119046.       if( sqlite3ExprCompare(0, pSrc->aColExpr->a[i].pExpr,

  119047.                              pDest->aColExpr->a[i].pExpr, -1)!=0 ){

  119048.         return 0;   /* Different expressions in the index */

  119049.       }

  119050.     }

  119051.     if( pSrc->aSortOrder[i]!=pDest->aSortOrder[i] ){

  119052.       return 0;   /* Different sort orders */

  119053.     }

  119054.     if( sqlite3_stricmp(pSrc->azColl[i],pDest->azColl[i])!=0 ){

  119055.       return 0;   /* Different collating sequences */

  119056.     }

  119057.   }

  119058.   if( sqlite3ExprCompare(0, pSrc->pPartIdxWhere, pDest->pPartIdxWhere, -1) ){

  119059.     return 0;     /* Different WHERE clauses */

  119060.   }

  119061. 

  119062.   /* If no test above fails then the indices must be compatible */

  119063.   return 1;

  119064. }

  119065. 

  119066. /*

  119067. ** Attempt the transfer optimization on INSERTs of the form

  119068. **

  119069. **     INSERT INTO tab1 SELECT * FROM tab2;

  119070. **

  119071. ** The xfer optimization transfers raw records from tab2 over to tab1.  

  119072. ** Columns are not decoded and reassembled, which greatly improves

  119073. ** performance.  Raw index records are transferred in the same way.

  119074. **

  119075. ** The xfer optimization is only attempted if tab1 and tab2 are compatible.

  119076. ** There are lots of rules for determining compatibility - see comments

  119077. ** embedded in the code for details.

  119078. **

  119079. ** This routine returns TRUE if the optimization is guaranteed to be used.

  119080. ** Sometimes the xfer optimization will only work if the destination table

  119081. ** is empty - a factor that can only be determined at run-time.  In that

  119082. ** case, this routine generates code for the xfer optimization but also

  119083. ** does a test to see if the destination table is empty and jumps over the

  119084. ** xfer optimization code if the test fails.  In that case, this routine

  119085. ** returns FALSE so that the caller will know to go ahead and generate

  119086. ** an unoptimized transfer.  This routine also returns FALSE if there

  119087. ** is no chance that the xfer optimization can be applied.

  119088. **

  119089. ** This optimization is particularly useful at making VACUUM run faster.

  119090. */

  119091. static int xferOptimization(

  119092.   Parse *pParse,        /* Parser context */

  119093.   Table *pDest,         /* The table we are inserting into */

  119094.   Select *pSelect,      /* A SELECT statement to use as the data source */

  119095.   int onError,          /* How to handle constraint errors */

  119096.   int iDbDest           /* The database of pDest */

  119097. ){

  119098.   sqlite3 *db = pParse->db;

  119099.   ExprList *pEList;                /* The result set of the SELECT */

  119100.   Table *pSrc;                     /* The table in the FROM clause of SELECT */

  119101.   Index *pSrcIdx, *pDestIdx;       /* Source and destination indices */

  119102.   struct SrcList_item *pItem;      /* An element of pSelect->pSrc */

  119103.   int i;                           /* Loop counter */

  119104.   int iDbSrc;                      /* The database of pSrc */

  119105.   int iSrc, iDest;                 /* Cursors from source and destination */

  119106.   int addr1, addr2;                /* Loop addresses */

  119107.   int emptyDestTest = 0;           /* Address of test for empty pDest */

  119108.   int emptySrcTest = 0;            /* Address of test for empty pSrc */

  119109.   Vdbe *v;                         /* The VDBE we are building */

  119110.   int regAutoinc;                  /* Memory register used by AUTOINC */

  119111.   int destHasUniqueIdx = 0;        /* True if pDest has a UNIQUE index */

  119112.   int regData, regRowid;           /* Registers holding data and rowid */

  119113. 

  119114.   if( pSelect==0 ){

  119115.     return 0;   /* Must be of the form  INSERT INTO ... SELECT ... */

  119116.   }

  119117.   if( pParse->pWith || pSelect->pWith ){

  119118.     /* Do not attempt to process this query if there are an WITH clauses

  119119.     ** attached to it. Proceeding may generate a false "no such table: xxx"

  119120.     ** error if pSelect reads from a CTE named "xxx".  */

  119121.     return 0;

  119122.   }

  119123.   if( sqlite3TriggerList(pParse, pDest) ){

  119124.     return 0;   /* tab1 must not have triggers */

  119125.   }

  119126. #ifndef SQLITE_OMIT_VIRTUALTABLE

  119127.   if( IsVirtual(pDest) ){

  119128.     return 0;   /* tab1 must not be a virtual table */

  119129.   }

  119130. #endif

  119131.   if( onError==OE_Default ){

  119132.     if( pDest->iPKey>=0 ) onError = pDest->keyConf;

  119133.     if( onError==OE_Default ) onError = OE_Abort;

  119134.   }

  119135.   assert(pSelect->pSrc);   /* allocated even if there is no FROM clause */

  119136.   if( pSelect->pSrc->nSrc!=1 ){

  119137.     return 0;   /* FROM clause must have exactly one term */

  119138.   }

  119139.   if( pSelect->pSrc->a[0].pSelect ){

  119140.     return 0;   /* FROM clause cannot contain a subquery */

  119141.   }

  119142.   if( pSelect->pWhere ){

  119143.     return 0;   /* SELECT may not have a WHERE clause */

  119144.   }

  119145.   if( pSelect->pOrderBy ){

  119146.     return 0;   /* SELECT may not have an ORDER BY clause */

  119147.   }

  119148.   /* Do not need to test for a HAVING clause.  If HAVING is present but

  119149.   ** there is no ORDER BY, we will get an error. */

  119150.   if( pSelect->pGroupBy ){

  119151.     return 0;   /* SELECT may not have a GROUP BY clause */

  119152.   }

  119153.   if( pSelect->pLimit ){

  119154.     return 0;   /* SELECT may not have a LIMIT clause */

  119155.   }

  119156.   if( pSelect->pPrior ){

  119157.     return 0;   /* SELECT may not be a compound query */

  119158.   }

  119159.   if( pSelect->selFlags & SF_Distinct ){

  119160.     return 0;   /* SELECT may not be DISTINCT */

  119161.   }

  119162.   pEList = pSelect->pEList;

  119163.   assert( pEList!=0 );

  119164.   if( pEList->nExpr!=1 ){

  119165.     return 0;   /* The result set must have exactly one column */

  119166.   }

  119167.   assert( pEList->a[0].pExpr );

  119168.   if( pEList->a[0].pExpr->op!=TK_ASTERISK ){

  119169.     return 0;   /* The result set must be the special operator "*" */

  119170.   }

  119171. 

  119172.   /* At this point we have established that the statement is of the

  119173.   ** correct syntactic form to participate in this optimization.  Now

  119174.   ** we have to check the semantics.

  119175.   */

  119176.   pItem = pSelect->pSrc->a;

  119177.   pSrc = sqlite3LocateTableItem(pParse, 0, pItem);

  119178.   if( pSrc==0 ){

  119179.     return 0;   /* FROM clause does not contain a real table */

  119180.   }

  119181.   if( pSrc->tnum==pDest->tnum && pSrc->pSchema==pDest->pSchema ){

  119182.     testcase( pSrc!=pDest ); /* Possible due to bad sqlite_master.rootpage */

  119183.     return 0;   /* tab1 and tab2 may not be the same table */

  119184.   }

  119185.   if( HasRowid(pDest)!=HasRowid(pSrc) ){

  119186.     return 0;   /* source and destination must both be WITHOUT ROWID or not */

  119187.   }

  119188. #ifndef SQLITE_OMIT_VIRTUALTABLE

  119189.   if( IsVirtual(pSrc) ){

  119190.     return 0;   /* tab2 must not be a virtual table */

  119191.   }

  119192. #endif

  119193.   if( pSrc->pSelect ){

  119194.     return 0;   /* tab2 may not be a view */

  119195.   }

  119196.   if( pDest->nCol!=pSrc->nCol ){

  119197.     return 0;   /* Number of columns must be the same in tab1 and tab2 */

  119198.   }

  119199.   if( pDest->iPKey!=pSrc->iPKey ){

  119200.     return 0;   /* Both tables must have the same INTEGER PRIMARY KEY */

  119201.   }

  119202.   for(i=0; i<pDest->nCol; i++){

  119203.     Column *pDestCol = &pDest->aCol[i];

  119204.     Column *pSrcCol = &pSrc->aCol[i];

  119205. #ifdef SQLITE_ENABLE_HIDDEN_COLUMNS

  119206.     if( (db->mDbFlags & DBFLAG_Vacuum)==0 

  119207.      && (pDestCol->colFlags | pSrcCol->colFlags) & COLFLAG_HIDDEN 

  119208.     ){

  119209.       return 0;    /* Neither table may have __hidden__ columns */

  119210.     }

  119211. #endif

  119212.     if( pDestCol->affinity!=pSrcCol->affinity ){

  119213.       return 0;    /* Affinity must be the same on all columns */

  119214.     }

  119215.     if( sqlite3_stricmp(pDestCol->zColl, pSrcCol->zColl)!=0 ){

  119216.       return 0;    /* Collating sequence must be the same on all columns */

  119217.     }

  119218.     if( pDestCol->notNull && !pSrcCol->notNull ){

  119219.       return 0;    /* tab2 must be NOT NULL if tab1 is */

  119220.     }

  119221.     /* Default values for second and subsequent columns need to match. */

  119222.     if( i>0 ){

  119223.       assert( pDestCol->pDflt==0 || pDestCol->pDflt->op==TK_SPAN );

  119224.       assert( pSrcCol->pDflt==0 || pSrcCol->pDflt->op==TK_SPAN );

  119225.       if( (pDestCol->pDflt==0)!=(pSrcCol->pDflt==0) 

  119226.        || (pDestCol->pDflt && strcmp(pDestCol->pDflt->u.zToken,

  119227.                                        pSrcCol->pDflt->u.zToken)!=0)

  119228.       ){

  119229.         return 0;    /* Default values must be the same for all columns */

  119230.       }

  119231.     }

  119232.   }

  119233.   for(pDestIdx=pDest->pIndex; pDestIdx; pDestIdx=pDestIdx->pNext){

  119234.     if( IsUniqueIndex(pDestIdx) ){

  119235.       destHasUniqueIdx = 1;

  119236.     }

  119237.     for(pSrcIdx=pSrc->pIndex; pSrcIdx; pSrcIdx=pSrcIdx->pNext){

  119238.       if( xferCompatibleIndex(pDestIdx, pSrcIdx) ) break;

  119239.     }

  119240.     if( pSrcIdx==0 ){

  119241.       return 0;    /* pDestIdx has no corresponding index in pSrc */

  119242.     }

  119243.     if( pSrcIdx->tnum==pDestIdx->tnum && pSrc->pSchema==pDest->pSchema

  119244.          && sqlite3FaultSim(411)==SQLITE_OK ){

  119245.       /* The sqlite3FaultSim() call allows this corruption test to be

  119246.       ** bypassed during testing, in order to exercise other corruption tests

  119247.       ** further downstream. */

  119248.       return 0;   /* Corrupt schema - two indexes on the same btree */

  119249.     }

  119250.   }

  119251. #ifndef SQLITE_OMIT_CHECK

  119252.   if( pDest->pCheck && sqlite3ExprListCompare(pSrc->pCheck,pDest->pCheck,-1) ){

  119253.     return 0;   /* Tables have different CHECK constraints.  Ticket #2252 */

  119254.   }

  119255. #endif

  119256. #ifndef SQLITE_OMIT_FOREIGN_KEY

  119257.   /* Disallow the transfer optimization if the destination table constains

  119258.   ** any foreign key constraints.  This is more restrictive than necessary.

  119259.   ** But the main beneficiary of the transfer optimization is the VACUUM 

  119260.   ** command, and the VACUUM command disables foreign key constraints.  So

  119261.   ** the extra complication to make this rule less restrictive is probably

  119262.   ** not worth the effort.  Ticket [6284df89debdfa61db8073e062908af0c9b6118e]

  119263.   */

  119264.   if( (db->flags & SQLITE_ForeignKeys)!=0 && pDest->pFKey!=0 ){

  119265.     return 0;

  119266.   }

  119267. #endif

  119268.   if( (db->flags & SQLITE_CountRows)!=0 ){

  119269.     return 0;  /* xfer opt does not play well with PRAGMA count_changes */

  119270.   }

  119271. 

  119272.   /* If we get this far, it means that the xfer optimization is at

  119273.   ** least a possibility, though it might only work if the destination

  119274.   ** table (tab1) is initially empty.

  119275.   */

  119276. #ifdef SQLITE_TEST

  119277.   sqlite3_xferopt_count++;

  119278. #endif

  119279.   iDbSrc = sqlite3SchemaToIndex(db, pSrc->pSchema);

  119280.   v = sqlite3GetVdbe(pParse);

  119281.   sqlite3CodeVerifySchema(pParse, iDbSrc);

  119282.   iSrc = pParse->nTab++;

  119283.   iDest = pParse->nTab++;

  119284.   regAutoinc = autoIncBegin(pParse, iDbDest, pDest);

  119285.   regData = sqlite3GetTempReg(pParse);

  119286.   regRowid = sqlite3GetTempReg(pParse);

  119287.   sqlite3OpenTable(pParse, iDest, iDbDest, pDest, OP_OpenWrite);

  119288.   assert( HasRowid(pDest) || destHasUniqueIdx );

  119289.   if( (db->mDbFlags & DBFLAG_Vacuum)==0 && (

  119290.       (pDest->iPKey<0 && pDest->pIndex!=0)          /* (1) */

  119291.    || destHasUniqueIdx                              /* (2) */

  119292.    || (onError!=OE_Abort && onError!=OE_Rollback)   /* (3) */

  119293.   )){

  119294.     /* In some circumstances, we are able to run the xfer optimization

  119295.     ** only if the destination table is initially empty. Unless the

  119296.     ** DBFLAG_Vacuum flag is set, this block generates code to make

  119297.     ** that determination. If DBFLAG_Vacuum is set, then the destination

  119298.     ** table is always empty.

  119299.     **

  119300.     ** Conditions under which the destination must be empty:

  119301.     **

  119302.     ** (1) There is no INTEGER PRIMARY KEY but there are indices.

  119303.     **     (If the destination is not initially empty, the rowid fields

  119304.     **     of index entries might need to change.)

  119305.     **

  119306.     ** (2) The destination has a unique index.  (The xfer optimization 

  119307.     **     is unable to test uniqueness.)

  119308.     **

  119309.     ** (3) onError is something other than OE_Abort and OE_Rollback.

  119310.     */

  119311.     addr1 = sqlite3VdbeAddOp2(v, OP_Rewind, iDest, 0); VdbeCoverage(v);

  119312.     emptyDestTest = sqlite3VdbeAddOp0(v, OP_Goto);

  119313.     sqlite3VdbeJumpHere(v, addr1);

  119314.   }

  119315.   if( HasRowid(pSrc) ){

  119316.     u8 insFlags;

  119317.     sqlite3OpenTable(pParse, iSrc, iDbSrc, pSrc, OP_OpenRead);

  119318.     emptySrcTest = sqlite3VdbeAddOp2(v, OP_Rewind, iSrc, 0); VdbeCoverage(v);

  119319.     if( pDest->iPKey>=0 ){

  119320.       addr1 = sqlite3VdbeAddOp2(v, OP_Rowid, iSrc, regRowid);

  119321.       sqlite3VdbeVerifyAbortable(v, onError);

  119322.       addr2 = sqlite3VdbeAddOp3(v, OP_NotExists, iDest, 0, regRowid);

  119323.       VdbeCoverage(v);

  119324.       sqlite3RowidConstraint(pParse, onError, pDest);

  119325.       sqlite3VdbeJumpHere(v, addr2);

  119326.       autoIncStep(pParse, regAutoinc, regRowid);

  119327.     }else if( pDest->pIndex==0 && !(db->mDbFlags & DBFLAG_VacuumInto) ){

  119328.       addr1 = sqlite3VdbeAddOp2(v, OP_NewRowid, iDest, regRowid);

  119329.     }else{

  119330.       addr1 = sqlite3VdbeAddOp2(v, OP_Rowid, iSrc, regRowid);

  119331.       assert( (pDest->tabFlags & TF_Autoincrement)==0 );

  119332.     }

  119333.     sqlite3VdbeAddOp3(v, OP_RowData, iSrc, regData, 1);

  119334.     if( db->mDbFlags & DBFLAG_Vacuum ){

  119335.       sqlite3VdbeAddOp1(v, OP_SeekEnd, iDest);

  119336.       insFlags = OPFLAG_NCHANGE|OPFLAG_LASTROWID|

  119337.                            OPFLAG_APPEND|OPFLAG_USESEEKRESULT;

  119338.     }else{

  119339.       insFlags = OPFLAG_NCHANGE|OPFLAG_LASTROWID|OPFLAG_APPEND;

  119340.     }

  119341.     sqlite3VdbeAddOp4(v, OP_Insert, iDest, regData, regRowid,

  119342.                       (char*)pDest, P4_TABLE);

  119343.     sqlite3VdbeChangeP5(v, insFlags);

  119344.     sqlite3VdbeAddOp2(v, OP_Next, iSrc, addr1); VdbeCoverage(v);

  119345.     sqlite3VdbeAddOp2(v, OP_Close, iSrc, 0);

  119346.     sqlite3VdbeAddOp2(v, OP_Close, iDest, 0);

  119347.   }else{

  119348.     sqlite3TableLock(pParse, iDbDest, pDest->tnum, 1, pDest->zName);

  119349.     sqlite3TableLock(pParse, iDbSrc, pSrc->tnum, 0, pSrc->zName);

  119350.   }

  119351.   for(pDestIdx=pDest->pIndex; pDestIdx; pDestIdx=pDestIdx->pNext){

  119352.     u8 idxInsFlags = 0;

  119353.     for(pSrcIdx=pSrc->pIndex; ALWAYS(pSrcIdx); pSrcIdx=pSrcIdx->pNext){

  119354.       if( xferCompatibleIndex(pDestIdx, pSrcIdx) ) break;

  119355.     }

  119356.     assert( pSrcIdx );

  119357.     sqlite3VdbeAddOp3(v, OP_OpenRead, iSrc, pSrcIdx->tnum, iDbSrc);

  119358.     sqlite3VdbeSetP4KeyInfo(pParse, pSrcIdx);

  119359.     VdbeComment((v, "%s", pSrcIdx->zName));

  119360.     sqlite3VdbeAddOp3(v, OP_OpenWrite, iDest, pDestIdx->tnum, iDbDest);

  119361.     sqlite3VdbeSetP4KeyInfo(pParse, pDestIdx);

  119362.     sqlite3VdbeChangeP5(v, OPFLAG_BULKCSR);

  119363.     VdbeComment((v, "%s", pDestIdx->zName));

  119364.     addr1 = sqlite3VdbeAddOp2(v, OP_Rewind, iSrc, 0); VdbeCoverage(v);

  119365.     sqlite3VdbeAddOp3(v, OP_RowData, iSrc, regData, 1);

  119366.     if( db->mDbFlags & DBFLAG_Vacuum ){

  119367.       /* This INSERT command is part of a VACUUM operation, which guarantees

  119368.       ** that the destination table is empty. If all indexed columns use

  119369.       ** collation sequence BINARY, then it can also be assumed that the

  119370.       ** index will be populated by inserting keys in strictly sorted 

  119371.       ** order. In this case, instead of seeking within the b-tree as part

  119372.       ** of every OP_IdxInsert opcode, an OP_SeekEnd is added before the

  119373.       ** OP_IdxInsert to seek to the point within the b-tree where each key 

  119374.       ** should be inserted. This is faster.

  119375.       **

  119376.       ** If any of the indexed columns use a collation sequence other than

  119377.       ** BINARY, this optimization is disabled. This is because the user 

  119378.       ** might change the definition of a collation sequence and then run

  119379.       ** a VACUUM command. In that case keys may not be written in strictly

  119380.       ** sorted order.  */

  119381.       for(i=0; i<pSrcIdx->nColumn; i++){

  119382.         const char *zColl = pSrcIdx->azColl[i];

  119383.         if( sqlite3_stricmp(sqlite3StrBINARY, zColl) ) break;

  119384.       }

  119385.       if( i==pSrcIdx->nColumn ){

  119386.         idxInsFlags = OPFLAG_USESEEKRESULT;

  119387.         sqlite3VdbeAddOp1(v, OP_SeekEnd, iDest);

  119388.       }

  119389.     }

  119390.     if( !HasRowid(pSrc) && pDestIdx->idxType==SQLITE_IDXTYPE_PRIMARYKEY ){

  119391.       idxInsFlags |= OPFLAG_NCHANGE;

  119392.     }

  119393.     sqlite3VdbeAddOp2(v, OP_IdxInsert, iDest, regData);

  119394.     sqlite3VdbeChangeP5(v, idxInsFlags|OPFLAG_APPEND);

  119395.     sqlite3VdbeAddOp2(v, OP_Next, iSrc, addr1+1); VdbeCoverage(v);

  119396.     sqlite3VdbeJumpHere(v, addr1);

  119397.     sqlite3VdbeAddOp2(v, OP_Close, iSrc, 0);

  119398.     sqlite3VdbeAddOp2(v, OP_Close, iDest, 0);

  119399.   }

  119400.   if( emptySrcTest ) sqlite3VdbeJumpHere(v, emptySrcTest);

  119401.   sqlite3ReleaseTempReg(pParse, regRowid);

  119402.   sqlite3ReleaseTempReg(pParse, regData);

  119403.   if( emptyDestTest ){

  119404.     sqlite3AutoincrementEnd(pParse);

  119405.     sqlite3VdbeAddOp2(v, OP_Halt, SQLITE_OK, 0);

  119406.     sqlite3VdbeJumpHere(v, emptyDestTest);

  119407.     sqlite3VdbeAddOp2(v, OP_Close, iDest, 0);

  119408.     return 0;

  119409.   }else{

  119410.     return 1;

  119411.   }

  119412. }

  119413. #endif /* SQLITE_OMIT_XFER_OPT */

  119414. 

  119415. /************** End of insert.c **********************************************/

  119416. /************** Begin file legacy.c ******************************************/

  119417. /*

  119418. ** 2001 September 15

  119419. **

  119420. ** The author disclaims copyright to this source code.  In place of

  119421. ** a legal notice, here is a blessing:

  119422. **

  119423. **    May you do good and not evil.

  119424. **    May you find forgiveness for yourself and forgive others.

  119425. **    May you share freely, never taking more than you give.

  119426. **

  119427. *************************************************************************

  119428. ** Main file for the SQLite library.  The routines in this file

  119429. ** implement the programmer interface to the library.  Routines in

  119430. ** other files are for internal use by SQLite and should not be

  119431. ** accessed by users of the library.

  119432. */

  119433. 

  119434. /* #include "sqliteInt.h" */

  119435. 

  119436. /*

  119437. ** Execute SQL code.  Return one of the SQLITE_ success/failure

  119438. ** codes.  Also write an error message into memory obtained from

  119439. ** malloc() and make *pzErrMsg point to that message.

  119440. **

  119441. ** If the SQL is a query, then for each row in the query result

  119442. ** the xCallback() function is called.  pArg becomes the first

  119443. ** argument to xCallback().  If xCallback=NULL then no callback

  119444. ** is invoked, even for queries.

  119445. */

  119446. SQLITE_API int sqlite3_exec(

  119447.   sqlite3 *db,                /* The database on which the SQL executes */

  119448.   const char *zSql,           /* The SQL to be executed */

  119449.   sqlite3_callback xCallback, /* Invoke this callback routine */

  119450.   void *pArg,                 /* First argument to xCallback() */

  119451.   char **pzErrMsg             /* Write error messages here */

  119452. ){

  119453.   int rc = SQLITE_OK;         /* Return code */

  119454.   const char *zLeftover;      /* Tail of unprocessed SQL */

  119455.   sqlite3_stmt *pStmt = 0;    /* The current SQL statement */

  119456.   char **azCols = 0;          /* Names of result columns */

  119457.   int callbackIsInit;         /* True if callback data is initialized */

  119458. 

  119459.   if( !sqlite3SafetyCheckOk(db) ) return SQLITE_MISUSE_BKPT;

  119460.   if( zSql==0 ) zSql = "";

  119461. 

  119462.   sqlite3_mutex_enter(db->mutex);

  119463.   sqlite3Error(db, SQLITE_OK);

  119464.   while( rc==SQLITE_OK && zSql[0] ){

  119465.     int nCol = 0;

  119466.     char **azVals = 0;

  119467. 

  119468.     pStmt = 0;

  119469.     rc = sqlite3_prepare_v2(db, zSql, -1, &pStmt, &zLeftover);

  119470.     assert( rc==SQLITE_OK || pStmt==0 );

  119471.     if( rc!=SQLITE_OK ){

  119472.       continue;

  119473.     }

  119474.     if( !pStmt ){

  119475.       /* this happens for a comment or white-space */

  119476.       zSql = zLeftover;

  119477.       continue;

  119478.     }

  119479.     callbackIsInit = 0;

  119480. 

  119481.     while( 1 ){

  119482.       int i;

  119483.       rc = sqlite3_step(pStmt);

  119484. 

  119485.       /* Invoke the callback function if required */

  119486.       if( xCallback && (SQLITE_ROW==rc || 

  119487.           (SQLITE_DONE==rc && !callbackIsInit

  119488.                            && db->flags&SQLITE_NullCallback)) ){

  119489.         if( !callbackIsInit ){

  119490.           nCol = sqlite3_column_count(pStmt);

  119491.           azCols = sqlite3DbMallocRaw(db, (2*nCol+1)*sizeof(const char*));

  119492.           if( azCols==0 ){

  119493.             goto exec_out;

  119494.           }

  119495.           for(i=0; i<nCol; i++){

  119496.             azCols[i] = (char *)sqlite3_column_name(pStmt, i);

  119497.             /* sqlite3VdbeSetColName() installs column names as UTF8

  119498.             ** strings so there is no way for sqlite3_column_name() to fail. */

  119499.             assert( azCols[i]!=0 );

  119500.           }

  119501.           callbackIsInit = 1;

  119502.         }

  119503.         if( rc==SQLITE_ROW ){

  119504.           azVals = &azCols[nCol];

  119505.           for(i=0; i<nCol; i++){

  119506.             azVals[i] = (char *)sqlite3_column_text(pStmt, i);

  119507.             if( !azVals[i] && sqlite3_column_type(pStmt, i)!=SQLITE_NULL ){

  119508.               sqlite3OomFault(db);

  119509.               goto exec_out;

  119510.             }

  119511.           }

  119512.           azVals[i] = 0;

  119513.         }

  119514.         if( xCallback(pArg, nCol, azVals, azCols) ){

  119515.           /* EVIDENCE-OF: R-38229-40159 If the callback function to

  119516.           ** sqlite3_exec() returns non-zero, then sqlite3_exec() will

  119517.           ** return SQLITE_ABORT. */

  119518.           rc = SQLITE_ABORT;

  119519.           sqlite3VdbeFinalize((Vdbe *)pStmt);

  119520.           pStmt = 0;

  119521.           sqlite3Error(db, SQLITE_ABORT);

  119522.           goto exec_out;

  119523.         }

  119524.       }

  119525. 

  119526.       if( rc!=SQLITE_ROW ){

  119527.         rc = sqlite3VdbeFinalize((Vdbe *)pStmt);

  119528.         pStmt = 0;

  119529.         zSql = zLeftover;

  119530.         while( sqlite3Isspace(zSql[0]) ) zSql++;

  119531.         break;

  119532.       }

  119533.     }

  119534. 

  119535.     sqlite3DbFree(db, azCols);

  119536.     azCols = 0;

  119537.   }

  119538. 

  119539. exec_out:

  119540.   if( pStmt ) sqlite3VdbeFinalize((Vdbe *)pStmt);

  119541.   sqlite3DbFree(db, azCols);

  119542. 

  119543.   rc = sqlite3ApiExit(db, rc);

  119544.   if( rc!=SQLITE_OK && pzErrMsg ){

  119545.     *pzErrMsg = sqlite3DbStrDup(0, sqlite3_errmsg(db));

  119546.     if( *pzErrMsg==0 ){

  119547.       rc = SQLITE_NOMEM_BKPT;

  119548.       sqlite3Error(db, SQLITE_NOMEM);

  119549.     }

  119550.   }else if( pzErrMsg ){

  119551.     *pzErrMsg = 0;

  119552.   }

  119553. 

  119554.   assert( (rc&db->errMask)==rc );

  119555.   sqlite3_mutex_leave(db->mutex);

  119556.   return rc;

  119557. }

  119558. 

  119559. /************** End of legacy.c **********************************************/

  119560. /************** Begin file loadext.c *****************************************/

  119561. /*

  119562. ** 2006 June 7

  119563. **

  119564. ** The author disclaims copyright to this source code.  In place of

  119565. ** a legal notice, here is a blessing:

  119566. **

  119567. **    May you do good and not evil.

  119568. **    May you find forgiveness for yourself and forgive others.

  119569. **    May you share freely, never taking more than you give.

  119570. **

  119571. *************************************************************************

  119572. ** This file contains code used to dynamically load extensions into

  119573. ** the SQLite library.

  119574. */

  119575. 

  119576. #ifndef SQLITE_CORE

  119577.   #define SQLITE_CORE 1  /* Disable the API redefinition in sqlite3ext.h */

  119578. #endif

  119579. /************** Include sqlite3ext.h in the middle of loadext.c **************/

  119580. /************** Begin file sqlite3ext.h **************************************/

  119581. /*

  119582. ** 2006 June 7

  119583. **

  119584. ** The author disclaims copyright to this source code.  In place of

  119585. ** a legal notice, here is a blessing:

  119586. **

  119587. **    May you do good and not evil.

  119588. **    May you find forgiveness for yourself and forgive others.

  119589. **    May you share freely, never taking more than you give.

  119590. **

  119591. *************************************************************************

  119592. ** This header file defines the SQLite interface for use by

  119593. ** shared libraries that want to be imported as extensions into

  119594. ** an SQLite instance.  Shared libraries that intend to be loaded

  119595. ** as extensions by SQLite should #include this file instead of 

  119596. ** sqlite3.h.

  119597. */

  119598. #ifndef SQLITE3EXT_H

  119599. #define SQLITE3EXT_H

  119600. /* #include "sqlite3.h" */

  119601. 

  119602. /*

  119603. ** The following structure holds pointers to all of the SQLite API

  119604. ** routines.

  119605. **

  119606. ** WARNING:  In order to maintain backwards compatibility, add new

  119607. ** interfaces to the end of this structure only.  If you insert new

  119608. ** interfaces in the middle of this structure, then older different

  119609. ** versions of SQLite will not be able to load each other's shared

  119610. ** libraries!

  119611. */

  119612. struct sqlite3_api_routines {

  119613.   void * (*aggregate_context)(sqlite3_context*,int nBytes);

  119614.   int  (*aggregate_count)(sqlite3_context*);

  119615.   int  (*bind_blob)(sqlite3_stmt*,int,const void*,int n,void(*)(void*));

  119616.   int  (*bind_double)(sqlite3_stmt*,int,double);

  119617.   int  (*bind_int)(sqlite3_stmt*,int,int);

  119618.   int  (*bind_int64)(sqlite3_stmt*,int,sqlite_int64);

  119619.   int  (*bind_null)(sqlite3_stmt*,int);

  119620.   int  (*bind_parameter_count)(sqlite3_stmt*);

  119621.   int  (*bind_parameter_index)(sqlite3_stmt*,const char*zName);

  119622.   const char * (*bind_parameter_name)(sqlite3_stmt*,int);

  119623.   int  (*bind_text)(sqlite3_stmt*,int,const char*,int n,void(*)(void*));

  119624.   int  (*bind_text16)(sqlite3_stmt*,int,const void*,int,void(*)(void*));

  119625.   int  (*bind_value)(sqlite3_stmt*,int,const sqlite3_value*);

  119626.   int  (*busy_handler)(sqlite3*,int(*)(void*,int),void*);

  119627.   int  (*busy_timeout)(sqlite3*,int ms);

  119628.   int  (*changes)(sqlite3*);

  119629.   int  (*close)(sqlite3*);

  119630.   int  (*collation_needed)(sqlite3*,void*,void(*)(void*,sqlite3*,

  119631.                            int eTextRep,const char*));

  119632.   int  (*collation_needed16)(sqlite3*,void*,void(*)(void*,sqlite3*,

  119633.                              int eTextRep,const void*));

  119634.   const void * (*column_blob)(sqlite3_stmt*,int iCol);

  119635.   int  (*column_bytes)(sqlite3_stmt*,int iCol);

  119636.   int  (*column_bytes16)(sqlite3_stmt*,int iCol);

  119637.   int  (*column_count)(sqlite3_stmt*pStmt);

  119638.   const char * (*column_database_name)(sqlite3_stmt*,int);

  119639.   const void * (*column_database_name16)(sqlite3_stmt*,int);

  119640.   const char * (*column_decltype)(sqlite3_stmt*,int i);

  119641.   const void * (*column_decltype16)(sqlite3_stmt*,int);

  119642.   double  (*column_double)(sqlite3_stmt*,int iCol);

  119643.   int  (*column_int)(sqlite3_stmt*,int iCol);

  119644.   sqlite_int64  (*column_int64)(sqlite3_stmt*,int iCol);

  119645.   const char * (*column_name)(sqlite3_stmt*,int);

  119646.   const void * (*column_name16)(sqlite3_stmt*,int);

  119647.   const char * (*column_origin_name)(sqlite3_stmt*,int);

  119648.   const void * (*column_origin_name16)(sqlite3_stmt*,int);

  119649.   const char * (*column_table_name)(sqlite3_stmt*,int);

  119650.   const void * (*column_table_name16)(sqlite3_stmt*,int);

  119651.   const unsigned char * (*column_text)(sqlite3_stmt*,int iCol);

  119652.   const void * (*column_text16)(sqlite3_stmt*,int iCol);

  119653.   int  (*column_type)(sqlite3_stmt*,int iCol);

  119654.   sqlite3_value* (*column_value)(sqlite3_stmt*,int iCol);

  119655.   void * (*commit_hook)(sqlite3*,int(*)(void*),void*);

  119656.   int  (*complete)(const char*sql);

  119657.   int  (*complete16)(const void*sql);

  119658.   int  (*create_collation)(sqlite3*,const char*,int,void*,

  119659.                            int(*)(void*,int,const void*,int,const void*));

  119660.   int  (*create_collation16)(sqlite3*,const void*,int,void*,

  119661.                              int(*)(void*,int,const void*,int,const void*));

  119662.   int  (*create_function)(sqlite3*,const char*,int,int,void*,

  119663.                           void (*xFunc)(sqlite3_context*,int,sqlite3_value**),

  119664.                           void (*xStep)(sqlite3_context*,int,sqlite3_value**),

  119665.                           void (*xFinal)(sqlite3_context*));

  119666.   int  (*create_function16)(sqlite3*,const void*,int,int,void*,

  119667.                             void (*xFunc)(sqlite3_context*,int,sqlite3_value**),

  119668.                             void (*xStep)(sqlite3_context*,int,sqlite3_value**),

  119669.                             void (*xFinal)(sqlite3_context*));

  119670.   int (*create_module)(sqlite3*,const char*,const sqlite3_module*,void*);

  119671.   int  (*data_count)(sqlite3_stmt*pStmt);

  119672.   sqlite3 * (*db_handle)(sqlite3_stmt*);

  119673.   int (*declare_vtab)(sqlite3*,const char*);

  119674.   int  (*enable_shared_cache)(int);

  119675.   int  (*errcode)(sqlite3*db);

  119676.   const char * (*errmsg)(sqlite3*);

  119677.   const void * (*errmsg16)(sqlite3*);

  119678.   int  (*exec)(sqlite3*,const char*,sqlite3_callback,void*,char**);

  119679.   int  (*expired)(sqlite3_stmt*);

  119680.   int  (*finalize)(sqlite3_stmt*pStmt);

  119681.   void  (*free)(void*);

  119682.   void  (*free_table)(char**result);

  119683.   int  (*get_autocommit)(sqlite3*);

  119684.   void * (*get_auxdata)(sqlite3_context*,int);

  119685.   int  (*get_table)(sqlite3*,const char*,char***,int*,int*,char**);

  119686.   int  (*global_recover)(void);

  119687.   void  (*interruptx)(sqlite3*);

  119688.   sqlite_int64  (*last_insert_rowid)(sqlite3*);

  119689.   const char * (*libversion)(void);

  119690.   int  (*libversion_number)(void);

  119691.   void *(*malloc)(int);

  119692.   char * (*mprintf)(const char*,...);

  119693.   int  (*open)(const char*,sqlite3**);

  119694.   int  (*open16)(const void*,sqlite3**);

  119695.   int  (*prepare)(sqlite3*,const char*,int,sqlite3_stmt**,const char**);

  119696.   int  (*prepare16)(sqlite3*,const void*,int,sqlite3_stmt**,const void**);

  119697.   void * (*profile)(sqlite3*,void(*)(void*,const char*,sqlite_uint64),void*);

  119698.   void  (*progress_handler)(sqlite3*,int,int(*)(void*),void*);

  119699.   void *(*realloc)(void*,int);

  119700.   int  (*reset)(sqlite3_stmt*pStmt);

  119701.   void  (*result_blob)(sqlite3_context*,const void*,int,void(*)(void*));

  119702.   void  (*result_double)(sqlite3_context*,double);

  119703.   void  (*result_error)(sqlite3_context*,const char*,int);

  119704.   void  (*result_error16)(sqlite3_context*,const void*,int);

  119705.   void  (*result_int)(sqlite3_context*,int);

  119706.   void  (*result_int64)(sqlite3_context*,sqlite_int64);

  119707.   void  (*result_null)(sqlite3_context*);

  119708.   void  (*result_text)(sqlite3_context*,const char*,int,void(*)(void*));

  119709.   void  (*result_text16)(sqlite3_context*,const void*,int,void(*)(void*));

  119710.   void  (*result_text16be)(sqlite3_context*,const void*,int,void(*)(void*));

  119711.   void  (*result_text16le)(sqlite3_context*,const void*,int,void(*)(void*));

  119712.   void  (*result_value)(sqlite3_context*,sqlite3_value*);

  119713.   void * (*rollback_hook)(sqlite3*,void(*)(void*),void*);

  119714.   int  (*set_authorizer)(sqlite3*,int(*)(void*,int,const char*,const char*,

  119715.                          const char*,const char*),void*);

  119716.   void  (*set_auxdata)(sqlite3_context*,int,void*,void (*)(void*));

  119717.   char * (*xsnprintf)(int,char*,const char*,...);

  119718.   int  (*step)(sqlite3_stmt*);

  119719.   int  (*table_column_metadata)(sqlite3*,const char*,const char*,const char*,

  119720.                                 char const**,char const**,int*,int*,int*);

  119721.   void  (*thread_cleanup)(void);

  119722.   int  (*total_changes)(sqlite3*);

  119723.   void * (*trace)(sqlite3*,void(*xTrace)(void*,const char*),void*);

  119724.   int  (*transfer_bindings)(sqlite3_stmt*,sqlite3_stmt*);

  119725.   void * (*update_hook)(sqlite3*,void(*)(void*,int ,char const*,char const*,

  119726.                                          sqlite_int64),void*);

  119727.   void * (*user_data)(sqlite3_context*);

  119728.   const void * (*value_blob)(sqlite3_value*);

  119729.   int  (*value_bytes)(sqlite3_value*);

  119730.   int  (*value_bytes16)(sqlite3_value*);

  119731.   double  (*value_double)(sqlite3_value*);

  119732.   int  (*value_int)(sqlite3_value*);

  119733.   sqlite_int64  (*value_int64)(sqlite3_value*);

  119734.   int  (*value_numeric_type)(sqlite3_value*);

  119735.   const unsigned char * (*value_text)(sqlite3_value*);

  119736.   const void * (*value_text16)(sqlite3_value*);

  119737.   const void * (*value_text16be)(sqlite3_value*);

  119738.   const void * (*value_text16le)(sqlite3_value*);

  119739.   int  (*value_type)(sqlite3_value*);

  119740.   char *(*vmprintf)(const char*,va_list);

  119741.   /* Added ??? */

  119742.   int (*overload_function)(sqlite3*, const char *zFuncName, int nArg);

  119743.   /* Added by 3.3.13 */

  119744.   int (*prepare_v2)(sqlite3*,const char*,int,sqlite3_stmt**,const char**);

  119745.   int (*prepare16_v2)(sqlite3*,const void*,int,sqlite3_stmt**,const void**);

  119746.   int (*clear_bindings)(sqlite3_stmt*);

  119747.   /* Added by 3.4.1 */

  119748.   int (*create_module_v2)(sqlite3*,const char*,const sqlite3_module*,void*,

  119749.                           void (*xDestroy)(void *));

  119750.   /* Added by 3.5.0 */

  119751.   int (*bind_zeroblob)(sqlite3_stmt*,int,int);

  119752.   int (*blob_bytes)(sqlite3_blob*);

  119753.   int (*blob_close)(sqlite3_blob*);

  119754.   int (*blob_open)(sqlite3*,const char*,const char*,const char*,sqlite3_int64,

  119755.                    int,sqlite3_blob**);

  119756.   int (*blob_read)(sqlite3_blob*,void*,int,int);

  119757.   int (*blob_write)(sqlite3_blob*,const void*,int,int);

  119758.   int (*create_collation_v2)(sqlite3*,const char*,int,void*,

  119759.                              int(*)(void*,int,const void*,int,const void*),

  119760.                              void(*)(void*));

  119761.   int (*file_control)(sqlite3*,const char*,int,void*);

  119762.   sqlite3_int64 (*memory_highwater)(int);

  119763.   sqlite3_int64 (*memory_used)(void);

  119764.   sqlite3_mutex *(*mutex_alloc)(int);

  119765.   void (*mutex_enter)(sqlite3_mutex*);

  119766.   void (*mutex_free)(sqlite3_mutex*);

  119767.   void (*mutex_leave)(sqlite3_mutex*);

  119768.   int (*mutex_try)(sqlite3_mutex*);

  119769.   int (*open_v2)(const char*,sqlite3**,int,const char*);

  119770.   int (*release_memory)(int);

  119771.   void (*result_error_nomem)(sqlite3_context*);

  119772.   void (*result_error_toobig)(sqlite3_context*);

  119773.   int (*sleep)(int);

  119774.   void (*soft_heap_limit)(int);

  119775.   sqlite3_vfs *(*vfs_find)(const char*);

  119776.   int (*vfs_register)(sqlite3_vfs*,int);

  119777.   int (*vfs_unregister)(sqlite3_vfs*);

  119778.   int (*xthreadsafe)(void);

  119779.   void (*result_zeroblob)(sqlite3_context*,int);

  119780.   void (*result_error_code)(sqlite3_context*,int);

  119781.   int (*test_control)(int, ...);

  119782.   void (*randomness)(int,void*);

  119783.   sqlite3 *(*context_db_handle)(sqlite3_context*);

  119784.   int (*extended_result_codes)(sqlite3*,int);

  119785.   int (*limit)(sqlite3*,int,int);

  119786.   sqlite3_stmt *(*next_stmt)(sqlite3*,sqlite3_stmt*);

  119787.   const char *(*sql)(sqlite3_stmt*);

  119788.   int (*status)(int,int*,int*,int);

  119789.   int (*backup_finish)(sqlite3_backup*);

  119790.   sqlite3_backup *(*backup_init)(sqlite3*,const char*,sqlite3*,const char*);

  119791.   int (*backup_pagecount)(sqlite3_backup*);

  119792.   int (*backup_remaining)(sqlite3_backup*);

  119793.   int (*backup_step)(sqlite3_backup*,int);

  119794.   const char *(*compileoption_get)(int);

  119795.   int (*compileoption_used)(const char*);

  119796.   int (*create_function_v2)(sqlite3*,const char*,int,int,void*,

  119797.                             void (*xFunc)(sqlite3_context*,int,sqlite3_value**),

  119798.                             void (*xStep)(sqlite3_context*,int,sqlite3_value**),

  119799.                             void (*xFinal)(sqlite3_context*),

  119800.                             void(*xDestroy)(void*));

  119801.   int (*db_config)(sqlite3*,int,...);

  119802.   sqlite3_mutex *(*db_mutex)(sqlite3*);

  119803.   int (*db_status)(sqlite3*,int,int*,int*,int);

  119804.   int (*extended_errcode)(sqlite3*);

  119805.   void (*log)(int,const char*,...);

  119806.   sqlite3_int64 (*soft_heap_limit64)(sqlite3_int64);

  119807.   const char *(*sourceid)(void);

  119808.   int (*stmt_status)(sqlite3_stmt*,int,int);

  119809.   int (*strnicmp)(const char*,const char*,int);

  119810.   int (*unlock_notify)(sqlite3*,void(*)(void**,int),void*);

  119811.   int (*wal_autocheckpoint)(sqlite3*,int);

  119812.   int (*wal_checkpoint)(sqlite3*,const char*);

  119813.   void *(*wal_hook)(sqlite3*,int(*)(void*,sqlite3*,const char*,int),void*);

  119814.   int (*blob_reopen)(sqlite3_blob*,sqlite3_int64);

  119815.   int (*vtab_config)(sqlite3*,int op,...);

  119816.   int (*vtab_on_conflict)(sqlite3*);

  119817.   /* Version 3.7.16 and later */

  119818.   int (*close_v2)(sqlite3*);

  119819.   const char *(*db_filename)(sqlite3*,const char*);

  119820.   int (*db_readonly)(sqlite3*,const char*);

  119821.   int (*db_release_memory)(sqlite3*);

  119822.   const char *(*errstr)(int);

  119823.   int (*stmt_busy)(sqlite3_stmt*);

  119824.   int (*stmt_readonly)(sqlite3_stmt*);

  119825.   int (*stricmp)(const char*,const char*);

  119826.   int (*uri_boolean)(const char*,const char*,int);

  119827.   sqlite3_int64 (*uri_int64)(const char*,const char*,sqlite3_int64);

  119828.   const char *(*uri_parameter)(const char*,const char*);

  119829.   char *(*xvsnprintf)(int,char*,const char*,va_list);

  119830.   int (*wal_checkpoint_v2)(sqlite3*,const char*,int,int*,int*);

  119831.   /* Version 3.8.7 and later */

  119832.   int (*auto_extension)(void(*)(void));

  119833.   int (*bind_blob64)(sqlite3_stmt*,int,const void*,sqlite3_uint64,

  119834.                      void(*)(void*));

  119835.   int (*bind_text64)(sqlite3_stmt*,int,const char*,sqlite3_uint64,

  119836.                       void(*)(void*),unsigned char);

  119837.   int (*cancel_auto_extension)(void(*)(void));

  119838.   int (*load_extension)(sqlite3*,const char*,const char*,char**);

  119839.   void *(*malloc64)(sqlite3_uint64);

  119840.   sqlite3_uint64 (*msize)(void*);

  119841.   void *(*realloc64)(void*,sqlite3_uint64);

  119842.   void (*reset_auto_extension)(void);

  119843.   void (*result_blob64)(sqlite3_context*,const void*,sqlite3_uint64,

  119844.                         void(*)(void*));

  119845.   void (*result_text64)(sqlite3_context*,const char*,sqlite3_uint64,

  119846.                          void(*)(void*), unsigned char);

  119847.   int (*strglob)(const char*,const char*);

  119848.   /* Version 3.8.11 and later */

  119849.   sqlite3_value *(*value_dup)(const sqlite3_value*);

  119850.   void (*value_free)(sqlite3_value*);

  119851.   int (*result_zeroblob64)(sqlite3_context*,sqlite3_uint64);

  119852.   int (*bind_zeroblob64)(sqlite3_stmt*, int, sqlite3_uint64);

  119853.   /* Version 3.9.0 and later */

  119854.   unsigned int (*value_subtype)(sqlite3_value*);

  119855.   void (*result_subtype)(sqlite3_context*,unsigned int);

  119856.   /* Version 3.10.0 and later */

  119857.   int (*status64)(int,sqlite3_int64*,sqlite3_int64*,int);

  119858.   int (*strlike)(const char*,const char*,unsigned int);

  119859.   int (*db_cacheflush)(sqlite3*);

  119860.   /* Version 3.12.0 and later */

  119861.   int (*system_errno)(sqlite3*);

  119862.   /* Version 3.14.0 and later */

  119863.   int (*trace_v2)(sqlite3*,unsigned,int(*)(unsigned,void*,void*,void*),void*);

  119864.   char *(*expanded_sql)(sqlite3_stmt*);

  119865.   /* Version 3.18.0 and later */

  119866.   void (*set_last_insert_rowid)(sqlite3*,sqlite3_int64);

  119867.   /* Version 3.20.0 and later */

  119868.   int (*prepare_v3)(sqlite3*,const char*,int,unsigned int,

  119869.                     sqlite3_stmt**,const char**);

  119870.   int (*prepare16_v3)(sqlite3*,const void*,int,unsigned int,

  119871.                       sqlite3_stmt**,const void**);

  119872.   int (*bind_pointer)(sqlite3_stmt*,int,void*,const char*,void(*)(void*));

  119873.   void (*result_pointer)(sqlite3_context*,void*,const char*,void(*)(void*));

  119874.   void *(*value_pointer)(sqlite3_value*,const char*);

  119875.   int (*vtab_nochange)(sqlite3_context*);

  119876.   int (*value_nochange)(sqlite3_value*);

  119877.   const char *(*vtab_collation)(sqlite3_index_info*,int);

  119878.   /* Version 3.24.0 and later */

  119879.   int (*keyword_count)(void);

  119880.   int (*keyword_name)(int,const char**,int*);

  119881.   int (*keyword_check)(const char*,int);

  119882.   sqlite3_str *(*str_new)(sqlite3*);

  119883.   char *(*str_finish)(sqlite3_str*);

  119884.   void (*str_appendf)(sqlite3_str*, const char *zFormat, ...);

  119885.   void (*str_vappendf)(sqlite3_str*, const char *zFormat, va_list);

  119886.   void (*str_append)(sqlite3_str*, const char *zIn, int N);

  119887.   void (*str_appendall)(sqlite3_str*, const char *zIn);

  119888.   void (*str_appendchar)(sqlite3_str*, int N, char C);

  119889.   void (*str_reset)(sqlite3_str*);

  119890.   int (*str_errcode)(sqlite3_str*);

  119891.   int (*str_length)(sqlite3_str*);

  119892.   char *(*str_value)(sqlite3_str*);

  119893.   /* Version 3.25.0 and later */

  119894.   int (*create_window_function)(sqlite3*,const char*,int,int,void*,

  119895.                             void (*xStep)(sqlite3_context*,int,sqlite3_value**),

  119896.                             void (*xFinal)(sqlite3_context*),

  119897.                             void (*xValue)(sqlite3_context*),

  119898.                             void (*xInv)(sqlite3_context*,int,sqlite3_value**),

  119899.                             void(*xDestroy)(void*));

  119900.   /* Version 3.26.0 and later */

  119901.   const char *(*normalized_sql)(sqlite3_stmt*);

  119902.   /* Version 3.28.0 and later */

  119903.   int (*stmt_isexplain)(sqlite3_stmt*);

  119904.   int (*value_frombind)(sqlite3_value*);

  119905. };

  119906. 

  119907. /*

  119908. ** This is the function signature used for all extension entry points.  It

  119909. ** is also defined in the file "loadext.c".

  119910. */

  119911. typedef int (*sqlite3_loadext_entry)(

  119912.   sqlite3 *db,                       /* Handle to the database. */

  119913.   char **pzErrMsg,                   /* Used to set error string on failure. */

  119914.   const sqlite3_api_routines *pThunk /* Extension API function pointers. */

  119915. );

  119916. 

  119917. /*

  119918. ** The following macros redefine the API routines so that they are

  119919. ** redirected through the global sqlite3_api structure.

  119920. **

  119921. ** This header file is also used by the loadext.c source file

  119922. ** (part of the main SQLite library - not an extension) so that

  119923. ** it can get access to the sqlite3_api_routines structure

  119924. ** definition.  But the main library does not want to redefine

  119925. ** the API.  So the redefinition macros are only valid if the

  119926. ** SQLITE_CORE macros is undefined.

  119927. */

  119928. #if !defined(SQLITE_CORE) && !defined(SQLITE_OMIT_LOAD_EXTENSION)

  119929. #define sqlite3_aggregate_context      sqlite3_api->aggregate_context

  119930. #ifndef SQLITE_OMIT_DEPRECATED

  119931. #define sqlite3_aggregate_count        sqlite3_api->aggregate_count

  119932. #endif

  119933. #define sqlite3_bind_blob              sqlite3_api->bind_blob

  119934. #define sqlite3_bind_double            sqlite3_api->bind_double

  119935. #define sqlite3_bind_int               sqlite3_api->bind_int

  119936. #define sqlite3_bind_int64             sqlite3_api->bind_int64

  119937. #define sqlite3_bind_null              sqlite3_api->bind_null

  119938. #define sqlite3_bind_parameter_count   sqlite3_api->bind_parameter_count

  119939. #define sqlite3_bind_parameter_index   sqlite3_api->bind_parameter_index

  119940. #define sqlite3_bind_parameter_name    sqlite3_api->bind_parameter_name

  119941. #define sqlite3_bind_text              sqlite3_api->bind_text

  119942. #define sqlite3_bind_text16            sqlite3_api->bind_text16

  119943. #define sqlite3_bind_value             sqlite3_api->bind_value

  119944. #define sqlite3_busy_handler           sqlite3_api->busy_handler

  119945. #define sqlite3_busy_timeout           sqlite3_api->busy_timeout

  119946. #define sqlite3_changes                sqlite3_api->changes

  119947. #define sqlite3_close                  sqlite3_api->close

  119948. #define sqlite3_collation_needed       sqlite3_api->collation_needed

  119949. #define sqlite3_collation_needed16     sqlite3_api->collation_needed16

  119950. #define sqlite3_column_blob            sqlite3_api->column_blob

  119951. #define sqlite3_column_bytes           sqlite3_api->column_bytes

  119952. #define sqlite3_column_bytes16         sqlite3_api->column_bytes16

  119953. #define sqlite3_column_count           sqlite3_api->column_count

  119954. #define sqlite3_column_database_name   sqlite3_api->column_database_name

  119955. #define sqlite3_column_database_name16 sqlite3_api->column_database_name16

  119956. #define sqlite3_column_decltype        sqlite3_api->column_decltype

  119957. #define sqlite3_column_decltype16      sqlite3_api->column_decltype16

  119958. #define sqlite3_column_double          sqlite3_api->column_double

  119959. #define sqlite3_column_int             sqlite3_api->column_int

  119960. #define sqlite3_column_int64           sqlite3_api->column_int64

  119961. #define sqlite3_column_name            sqlite3_api->column_name

  119962. #define sqlite3_column_name16          sqlite3_api->column_name16

  119963. #define sqlite3_column_origin_name     sqlite3_api->column_origin_name

  119964. #define sqlite3_column_origin_name16   sqlite3_api->column_origin_name16

  119965. #define sqlite3_column_table_name      sqlite3_api->column_table_name

  119966. #define sqlite3_column_table_name16    sqlite3_api->column_table_name16

  119967. #define sqlite3_column_text            sqlite3_api->column_text

  119968. #define sqlite3_column_text16          sqlite3_api->column_text16

  119969. #define sqlite3_column_type            sqlite3_api->column_type

  119970. #define sqlite3_column_value           sqlite3_api->column_value

  119971. #define sqlite3_commit_hook            sqlite3_api->commit_hook

  119972. #define sqlite3_complete               sqlite3_api->complete

  119973. #define sqlite3_complete16             sqlite3_api->complete16

  119974. #define sqlite3_create_collation       sqlite3_api->create_collation

  119975. #define sqlite3_create_collation16     sqlite3_api->create_collation16

  119976. #define sqlite3_create_function        sqlite3_api->create_function

  119977. #define sqlite3_create_function16      sqlite3_api->create_function16

  119978. #define sqlite3_create_module          sqlite3_api->create_module

  119979. #define sqlite3_create_module_v2       sqlite3_api->create_module_v2

  119980. #define sqlite3_data_count             sqlite3_api->data_count

  119981. #define sqlite3_db_handle              sqlite3_api->db_handle

  119982. #define sqlite3_declare_vtab           sqlite3_api->declare_vtab

  119983. #define sqlite3_enable_shared_cache    sqlite3_api->enable_shared_cache

  119984. #define sqlite3_errcode                sqlite3_api->errcode

  119985. #define sqlite3_errmsg                 sqlite3_api->errmsg

  119986. #define sqlite3_errmsg16               sqlite3_api->errmsg16

  119987. #define sqlite3_exec                   sqlite3_api->exec

  119988. #ifndef SQLITE_OMIT_DEPRECATED

  119989. #define sqlite3_expired                sqlite3_api->expired

  119990. #endif

  119991. #define sqlite3_finalize               sqlite3_api->finalize

  119992. #define sqlite3_free                   sqlite3_api->free

  119993. #define sqlite3_free_table             sqlite3_api->free_table

  119994. #define sqlite3_get_autocommit         sqlite3_api->get_autocommit

  119995. #define sqlite3_get_auxdata            sqlite3_api->get_auxdata

  119996. #define sqlite3_get_table              sqlite3_api->get_table

  119997. #ifndef SQLITE_OMIT_DEPRECATED

  119998. #define sqlite3_global_recover         sqlite3_api->global_recover

  119999. #endif

  120000. #define sqlite3_interrupt              sqlite3_api->interruptx

  120001. #define sqlite3_last_insert_rowid      sqlite3_api->last_insert_rowid

  120002. #define sqlite3_libversion             sqlite3_api->libversion

  120003. #define sqlite3_libversion_number      sqlite3_api->libversion_number

  120004. #define sqlite3_malloc                 sqlite3_api->malloc

  120005. #define sqlite3_mprintf                sqlite3_api->mprintf

  120006. #define sqlite3_open                   sqlite3_api->open

  120007. #define sqlite3_open16                 sqlite3_api->open16

  120008. #define sqlite3_prepare                sqlite3_api->prepare

  120009. #define sqlite3_prepare16              sqlite3_api->prepare16

  120010. #define sqlite3_prepare_v2             sqlite3_api->prepare_v2

  120011. #define sqlite3_prepare16_v2           sqlite3_api->prepare16_v2

  120012. #define sqlite3_profile                sqlite3_api->profile

  120013. #define sqlite3_progress_handler       sqlite3_api->progress_handler

  120014. #define sqlite3_realloc                sqlite3_api->realloc

  120015. #define sqlite3_reset                  sqlite3_api->reset

  120016. #define sqlite3_result_blob            sqlite3_api->result_blob

  120017. #define sqlite3_result_double          sqlite3_api->result_double

  120018. #define sqlite3_result_error           sqlite3_api->result_error

  120019. #define sqlite3_result_error16         sqlite3_api->result_error16

  120020. #define sqlite3_result_int             sqlite3_api->result_int

  120021. #define sqlite3_result_int64           sqlite3_api->result_int64

  120022. #define sqlite3_result_null            sqlite3_api->result_null

  120023. #define sqlite3_result_text            sqlite3_api->result_text

  120024. #define sqlite3_result_text16          sqlite3_api->result_text16

  120025. #define sqlite3_result_text16be        sqlite3_api->result_text16be

  120026. #define sqlite3_result_text16le        sqlite3_api->result_text16le

  120027. #define sqlite3_result_value           sqlite3_api->result_value

  120028. #define sqlite3_rollback_hook          sqlite3_api->rollback_hook

  120029. #define sqlite3_set_authorizer         sqlite3_api->set_authorizer

  120030. #define sqlite3_set_auxdata            sqlite3_api->set_auxdata

  120031. #define sqlite3_snprintf               sqlite3_api->xsnprintf

  120032. #define sqlite3_step                   sqlite3_api->step

  120033. #define sqlite3_table_column_metadata  sqlite3_api->table_column_metadata

  120034. #define sqlite3_thread_cleanup         sqlite3_api->thread_cleanup

  120035. #define sqlite3_total_changes          sqlite3_api->total_changes

  120036. #define sqlite3_trace                  sqlite3_api->trace

  120037. #ifndef SQLITE_OMIT_DEPRECATED

  120038. #define sqlite3_transfer_bindings      sqlite3_api->transfer_bindings

  120039. #endif

  120040. #define sqlite3_update_hook            sqlite3_api->update_hook

  120041. #define sqlite3_user_data              sqlite3_api->user_data

  120042. #define sqlite3_value_blob             sqlite3_api->value_blob

  120043. #define sqlite3_value_bytes            sqlite3_api->value_bytes

  120044. #define sqlite3_value_bytes16          sqlite3_api->value_bytes16

  120045. #define sqlite3_value_double           sqlite3_api->value_double

  120046. #define sqlite3_value_int              sqlite3_api->value_int

  120047. #define sqlite3_value_int64            sqlite3_api->value_int64

  120048. #define sqlite3_value_numeric_type     sqlite3_api->value_numeric_type

  120049. #define sqlite3_value_text             sqlite3_api->value_text

  120050. #define sqlite3_value_text16           sqlite3_api->value_text16

  120051. #define sqlite3_value_text16be         sqlite3_api->value_text16be

  120052. #define sqlite3_value_text16le         sqlite3_api->value_text16le

  120053. #define sqlite3_value_type             sqlite3_api->value_type

  120054. #define sqlite3_vmprintf               sqlite3_api->vmprintf

  120055. #define sqlite3_vsnprintf              sqlite3_api->xvsnprintf

  120056. #define sqlite3_overload_function      sqlite3_api->overload_function

  120057. #define sqlite3_prepare_v2             sqlite3_api->prepare_v2

  120058. #define sqlite3_prepare16_v2           sqlite3_api->prepare16_v2

  120059. #define sqlite3_clear_bindings         sqlite3_api->clear_bindings

  120060. #define sqlite3_bind_zeroblob          sqlite3_api->bind_zeroblob

  120061. #define sqlite3_blob_bytes             sqlite3_api->blob_bytes

  120062. #define sqlite3_blob_close             sqlite3_api->blob_close

  120063. #define sqlite3_blob_open              sqlite3_api->blob_open

  120064. #define sqlite3_blob_read              sqlite3_api->blob_read

  120065. #define sqlite3_blob_write             sqlite3_api->blob_write

  120066. #define sqlite3_create_collation_v2    sqlite3_api->create_collation_v2

  120067. #define sqlite3_file_control           sqlite3_api->file_control

  120068. #define sqlite3_memory_highwater       sqlite3_api->memory_highwater

  120069. #define sqlite3_memory_used            sqlite3_api->memory_used

  120070. #define sqlite3_mutex_alloc            sqlite3_api->mutex_alloc

  120071. #define sqlite3_mutex_enter            sqlite3_api->mutex_enter

  120072. #define sqlite3_mutex_free             sqlite3_api->mutex_free

  120073. #define sqlite3_mutex_leave            sqlite3_api->mutex_leave

  120074. #define sqlite3_mutex_try              sqlite3_api->mutex_try

  120075. #define sqlite3_open_v2                sqlite3_api->open_v2

  120076. #define sqlite3_release_memory         sqlite3_api->release_memory

  120077. #define sqlite3_result_error_nomem     sqlite3_api->result_error_nomem

  120078. #define sqlite3_result_error_toobig    sqlite3_api->result_error_toobig

  120079. #define sqlite3_sleep                  sqlite3_api->sleep

  120080. #define sqlite3_soft_heap_limit        sqlite3_api->soft_heap_limit

  120081. #define sqlite3_vfs_find               sqlite3_api->vfs_find

  120082. #define sqlite3_vfs_register           sqlite3_api->vfs_register

  120083. #define sqlite3_vfs_unregister         sqlite3_api->vfs_unregister

  120084. #define sqlite3_threadsafe             sqlite3_api->xthreadsafe

  120085. #define sqlite3_result_zeroblob        sqlite3_api->result_zeroblob

  120086. #define sqlite3_result_error_code      sqlite3_api->result_error_code

  120087. #define sqlite3_test_control           sqlite3_api->test_control

  120088. #define sqlite3_randomness             sqlite3_api->randomness

  120089. #define sqlite3_context_db_handle      sqlite3_api->context_db_handle

  120090. #define sqlite3_extended_result_codes  sqlite3_api->extended_result_codes

  120091. #define sqlite3_limit                  sqlite3_api->limit

  120092. #define sqlite3_next_stmt              sqlite3_api->next_stmt

  120093. #define sqlite3_sql                    sqlite3_api->sql

  120094. #define sqlite3_status                 sqlite3_api->status

  120095. #define sqlite3_backup_finish          sqlite3_api->backup_finish

  120096. #define sqlite3_backup_init            sqlite3_api->backup_init

  120097. #define sqlite3_backup_pagecount       sqlite3_api->backup_pagecount

  120098. #define sqlite3_backup_remaining       sqlite3_api->backup_remaining

  120099. #define sqlite3_backup_step            sqlite3_api->backup_step

  120100. #define sqlite3_compileoption_get      sqlite3_api->compileoption_get

  120101. #define sqlite3_compileoption_used     sqlite3_api->compileoption_used

  120102. #define sqlite3_create_function_v2     sqlite3_api->create_function_v2

  120103. #define sqlite3_db_config              sqlite3_api->db_config

  120104. #define sqlite3_db_mutex               sqlite3_api->db_mutex

  120105. #define sqlite3_db_status              sqlite3_api->db_status

  120106. #define sqlite3_extended_errcode       sqlite3_api->extended_errcode

  120107. #define sqlite3_log                    sqlite3_api->log

  120108. #define sqlite3_soft_heap_limit64      sqlite3_api->soft_heap_limit64

  120109. #define sqlite3_sourceid               sqlite3_api->sourceid

  120110. #define sqlite3_stmt_status            sqlite3_api->stmt_status

  120111. #define sqlite3_strnicmp               sqlite3_api->strnicmp

  120112. #define sqlite3_unlock_notify          sqlite3_api->unlock_notify

  120113. #define sqlite3_wal_autocheckpoint     sqlite3_api->wal_autocheckpoint

  120114. #define sqlite3_wal_checkpoint         sqlite3_api->wal_checkpoint

  120115. #define sqlite3_wal_hook               sqlite3_api->wal_hook

  120116. #define sqlite3_blob_reopen            sqlite3_api->blob_reopen

  120117. #define sqlite3_vtab_config            sqlite3_api->vtab_config

  120118. #define sqlite3_vtab_on_conflict       sqlite3_api->vtab_on_conflict

  120119. /* Version 3.7.16 and later */

  120120. #define sqlite3_close_v2               sqlite3_api->close_v2

  120121. #define sqlite3_db_filename            sqlite3_api->db_filename

  120122. #define sqlite3_db_readonly            sqlite3_api->db_readonly

  120123. #define sqlite3_db_release_memory      sqlite3_api->db_release_memory

  120124. #define sqlite3_errstr                 sqlite3_api->errstr

  120125. #define sqlite3_stmt_busy              sqlite3_api->stmt_busy

  120126. #define sqlite3_stmt_readonly          sqlite3_api->stmt_readonly

  120127. #define sqlite3_stricmp                sqlite3_api->stricmp

  120128. #define sqlite3_uri_boolean            sqlite3_api->uri_boolean

  120129. #define sqlite3_uri_int64              sqlite3_api->uri_int64

  120130. #define sqlite3_uri_parameter          sqlite3_api->uri_parameter

  120131. #define sqlite3_uri_vsnprintf          sqlite3_api->xvsnprintf

  120132. #define sqlite3_wal_checkpoint_v2      sqlite3_api->wal_checkpoint_v2

  120133. /* Version 3.8.7 and later */

  120134. #define sqlite3_auto_extension         sqlite3_api->auto_extension

  120135. #define sqlite3_bind_blob64            sqlite3_api->bind_blob64

  120136. #define sqlite3_bind_text64            sqlite3_api->bind_text64

  120137. #define sqlite3_cancel_auto_extension  sqlite3_api->cancel_auto_extension

  120138. #define sqlite3_load_extension         sqlite3_api->load_extension

  120139. #define sqlite3_malloc64               sqlite3_api->malloc64

  120140. #define sqlite3_msize                  sqlite3_api->msize

  120141. #define sqlite3_realloc64              sqlite3_api->realloc64

  120142. #define sqlite3_reset_auto_extension   sqlite3_api->reset_auto_extension

  120143. #define sqlite3_result_blob64          sqlite3_api->result_blob64

  120144. #define sqlite3_result_text64          sqlite3_api->result_text64

  120145. #define sqlite3_strglob                sqlite3_api->strglob

  120146. /* Version 3.8.11 and later */

  120147. #define sqlite3_value_dup              sqlite3_api->value_dup

  120148. #define sqlite3_value_free             sqlite3_api->value_free

  120149. #define sqlite3_result_zeroblob64      sqlite3_api->result_zeroblob64

  120150. #define sqlite3_bind_zeroblob64        sqlite3_api->bind_zeroblob64

  120151. /* Version 3.9.0 and later */

  120152. #define sqlite3_value_subtype          sqlite3_api->value_subtype

  120153. #define sqlite3_result_subtype         sqlite3_api->result_subtype

  120154. /* Version 3.10.0 and later */

  120155. #define sqlite3_status64               sqlite3_api->status64

  120156. #define sqlite3_strlike                sqlite3_api->strlike

  120157. #define sqlite3_db_cacheflush          sqlite3_api->db_cacheflush

  120158. /* Version 3.12.0 and later */

  120159. #define sqlite3_system_errno           sqlite3_api->system_errno

  120160. /* Version 3.14.0 and later */

  120161. #define sqlite3_trace_v2               sqlite3_api->trace_v2

  120162. #define sqlite3_expanded_sql           sqlite3_api->expanded_sql

  120163. /* Version 3.18.0 and later */

  120164. #define sqlite3_set_last_insert_rowid  sqlite3_api->set_last_insert_rowid

  120165. /* Version 3.20.0 and later */

  120166. #define sqlite3_prepare_v3             sqlite3_api->prepare_v3

  120167. #define sqlite3_prepare16_v3           sqlite3_api->prepare16_v3

  120168. #define sqlite3_bind_pointer           sqlite3_api->bind_pointer

  120169. #define sqlite3_result_pointer         sqlite3_api->result_pointer

  120170. #define sqlite3_value_pointer          sqlite3_api->value_pointer

  120171. /* Version 3.22.0 and later */

  120172. #define sqlite3_vtab_nochange          sqlite3_api->vtab_nochange

  120173. #define sqlite3_value_nochange         sqlite3_api->value_nochange

  120174. #define sqlite3_vtab_collation         sqlite3_api->vtab_collation

  120175. /* Version 3.24.0 and later */

  120176. #define sqlite3_keyword_count          sqlite3_api->keyword_count

  120177. #define sqlite3_keyword_name           sqlite3_api->keyword_name

  120178. #define sqlite3_keyword_check          sqlite3_api->keyword_check

  120179. #define sqlite3_str_new                sqlite3_api->str_new

  120180. #define sqlite3_str_finish             sqlite3_api->str_finish

  120181. #define sqlite3_str_appendf            sqlite3_api->str_appendf

  120182. #define sqlite3_str_vappendf           sqlite3_api->str_vappendf

  120183. #define sqlite3_str_append             sqlite3_api->str_append

  120184. #define sqlite3_str_appendall          sqlite3_api->str_appendall

  120185. #define sqlite3_str_appendchar         sqlite3_api->str_appendchar

  120186. #define sqlite3_str_reset              sqlite3_api->str_reset

  120187. #define sqlite3_str_errcode            sqlite3_api->str_errcode

  120188. #define sqlite3_str_length             sqlite3_api->str_length

  120189. #define sqlite3_str_value              sqlite3_api->str_value

  120190. /* Version 3.25.0 and later */

  120191. #define sqlite3_create_window_function sqlite3_api->create_window_function

  120192. /* Version 3.26.0 and later */

  120193. #define sqlite3_normalized_sql         sqlite3_api->normalized_sql

  120194. /* Version 3.28.0 and later */

  120195. #define sqlite3_stmt_isexplain         sqlite3_api->isexplain

  120196. #define sqlite3_value_frombind         sqlite3_api->frombind

  120197. #endif /* !defined(SQLITE_CORE) && !defined(SQLITE_OMIT_LOAD_EXTENSION) */

  120198. 

  120199. #if !defined(SQLITE_CORE) && !defined(SQLITE_OMIT_LOAD_EXTENSION)

  120200.   /* This case when the file really is being compiled as a loadable 

  120201.   ** extension */

  120202. # define SQLITE_EXTENSION_INIT1     const sqlite3_api_routines *sqlite3_api=0;

  120203. # define SQLITE_EXTENSION_INIT2(v)  sqlite3_api=v;

  120204. # define SQLITE_EXTENSION_INIT3     \

  120205.     extern const sqlite3_api_routines *sqlite3_api;

  120206. #else

  120207.   /* This case when the file is being statically linked into the 

  120208.   ** application */

  120209. # define SQLITE_EXTENSION_INIT1     /*no-op*/

  120210. # define SQLITE_EXTENSION_INIT2(v)  (void)v; /* unused parameter */

  120211. # define SQLITE_EXTENSION_INIT3     /*no-op*/

  120212. #endif

  120213. 

  120214. #endif /* SQLITE3EXT_H */

  120215. 

  120216. /************** End of sqlite3ext.h ******************************************/

  120217. /************** Continuing where we left off in loadext.c ********************/

  120218. /* #include "sqliteInt.h" */

  120219. 

  120220. #ifndef SQLITE_OMIT_LOAD_EXTENSION

  120221. /*

  120222. ** Some API routines are omitted when various features are

  120223. ** excluded from a build of SQLite.  Substitute a NULL pointer

  120224. ** for any missing APIs.

  120225. */

  120226. #ifndef SQLITE_ENABLE_COLUMN_METADATA

  120227. # define sqlite3_column_database_name   0

  120228. # define sqlite3_column_database_name16 0

  120229. # define sqlite3_column_table_name      0

  120230. # define sqlite3_column_table_name16    0

  120231. # define sqlite3_column_origin_name     0

  120232. # define sqlite3_column_origin_name16   0

  120233. #endif

  120234. 

  120235. #ifdef SQLITE_OMIT_AUTHORIZATION

  120236. # define sqlite3_set_authorizer         0

  120237. #endif

  120238. 

  120239. #ifdef SQLITE_OMIT_UTF16

  120240. # define sqlite3_bind_text16            0

  120241. # define sqlite3_collation_needed16     0

  120242. # define sqlite3_column_decltype16      0

  120243. # define sqlite3_column_name16          0

  120244. # define sqlite3_column_text16          0

  120245. # define sqlite3_complete16             0

  120246. # define sqlite3_create_collation16     0

  120247. # define sqlite3_create_function16      0

  120248. # define sqlite3_errmsg16               0

  120249. # define sqlite3_open16                 0

  120250. # define sqlite3_prepare16              0

  120251. # define sqlite3_prepare16_v2           0

  120252. # define sqlite3_prepare16_v3           0

  120253. # define sqlite3_result_error16         0

  120254. # define sqlite3_result_text16          0

  120255. # define sqlite3_result_text16be        0

  120256. # define sqlite3_result_text16le        0

  120257. # define sqlite3_value_text16           0

  120258. # define sqlite3_value_text16be         0

  120259. # define sqlite3_value_text16le         0

  120260. # define sqlite3_column_database_name16 0

  120261. # define sqlite3_column_table_name16    0

  120262. # define sqlite3_column_origin_name16   0

  120263. #endif

  120264. 

  120265. #ifdef SQLITE_OMIT_COMPLETE

  120266. # define sqlite3_complete 0

  120267. # define sqlite3_complete16 0

  120268. #endif

  120269. 

  120270. #ifdef SQLITE_OMIT_DECLTYPE

  120271. # define sqlite3_column_decltype16      0

  120272. # define sqlite3_column_decltype        0

  120273. #endif

  120274. 

  120275. #ifdef SQLITE_OMIT_PROGRESS_CALLBACK

  120276. # define sqlite3_progress_handler 0

  120277. #endif

  120278. 

  120279. #ifdef SQLITE_OMIT_VIRTUALTABLE

  120280. # define sqlite3_create_module 0

  120281. # define sqlite3_create_module_v2 0

  120282. # define sqlite3_declare_vtab 0

  120283. # define sqlite3_vtab_config 0

  120284. # define sqlite3_vtab_on_conflict 0

  120285. # define sqlite3_vtab_collation 0

  120286. #endif

  120287. 

  120288. #ifdef SQLITE_OMIT_SHARED_CACHE

  120289. # define sqlite3_enable_shared_cache 0

  120290. #endif

  120291. 

  120292. #if defined(SQLITE_OMIT_TRACE) || defined(SQLITE_OMIT_DEPRECATED)

  120293. # define sqlite3_profile       0

  120294. # define sqlite3_trace         0

  120295. #endif

  120296. 

  120297. #ifdef SQLITE_OMIT_GET_TABLE

  120298. # define sqlite3_free_table    0

  120299. # define sqlite3_get_table     0

  120300. #endif

  120301. 

  120302. #ifdef SQLITE_OMIT_INCRBLOB

  120303. #define sqlite3_bind_zeroblob  0

  120304. #define sqlite3_blob_bytes     0

  120305. #define sqlite3_blob_close     0

  120306. #define sqlite3_blob_open      0

  120307. #define sqlite3_blob_read      0

  120308. #define sqlite3_blob_write     0

  120309. #define sqlite3_blob_reopen    0

  120310. #endif

  120311. 

  120312. #if defined(SQLITE_OMIT_TRACE)

  120313. # define sqlite3_trace_v2      0

  120314. #endif

  120315. 

  120316. /*

  120317. ** The following structure contains pointers to all SQLite API routines.

  120318. ** A pointer to this structure is passed into extensions when they are

  120319. ** loaded so that the extension can make calls back into the SQLite

  120320. ** library.

  120321. **

  120322. ** When adding new APIs, add them to the bottom of this structure

  120323. ** in order to preserve backwards compatibility.

  120324. **

  120325. ** Extensions that use newer APIs should first call the

  120326. ** sqlite3_libversion_number() to make sure that the API they

  120327. ** intend to use is supported by the library.  Extensions should

  120328. ** also check to make sure that the pointer to the function is

  120329. ** not NULL before calling it.

  120330. */

  120331. static const sqlite3_api_routines sqlite3Apis = {

  120332.   sqlite3_aggregate_context,

  120333. #ifndef SQLITE_OMIT_DEPRECATED

  120334.   sqlite3_aggregate_count,

  120335. #else

  120336.   0,

  120337. #endif

  120338.   sqlite3_bind_blob,

  120339.   sqlite3_bind_double,

  120340.   sqlite3_bind_int,

  120341.   sqlite3_bind_int64,

  120342.   sqlite3_bind_null,

  120343.   sqlite3_bind_parameter_count,

  120344.   sqlite3_bind_parameter_index,

  120345.   sqlite3_bind_parameter_name,

  120346.   sqlite3_bind_text,

  120347.   sqlite3_bind_text16,

  120348.   sqlite3_bind_value,

  120349.   sqlite3_busy_handler,

  120350.   sqlite3_busy_timeout,

  120351.   sqlite3_changes,

  120352.   sqlite3_close,

  120353.   sqlite3_collation_needed,

  120354.   sqlite3_collation_needed16,

  120355.   sqlite3_column_blob,

  120356.   sqlite3_column_bytes,

  120357.   sqlite3_column_bytes16,

  120358.   sqlite3_column_count,

  120359.   sqlite3_column_database_name,

  120360.   sqlite3_column_database_name16,

  120361.   sqlite3_column_decltype,

  120362.   sqlite3_column_decltype16,

  120363.   sqlite3_column_double,

  120364.   sqlite3_column_int,

  120365.   sqlite3_column_int64,

  120366.   sqlite3_column_name,

  120367.   sqlite3_column_name16,

  120368.   sqlite3_column_origin_name,

  120369.   sqlite3_column_origin_name16,

  120370.   sqlite3_column_table_name,

  120371.   sqlite3_column_table_name16,

  120372.   sqlite3_column_text,

  120373.   sqlite3_column_text16,

  120374.   sqlite3_column_type,

  120375.   sqlite3_column_value,

  120376.   sqlite3_commit_hook,

  120377.   sqlite3_complete,

  120378.   sqlite3_complete16,

  120379.   sqlite3_create_collation,

  120380.   sqlite3_create_collation16,

  120381.   sqlite3_create_function,

  120382.   sqlite3_create_function16,

  120383.   sqlite3_create_module,

  120384.   sqlite3_data_count,

  120385.   sqlite3_db_handle,

  120386.   sqlite3_declare_vtab,

  120387.   sqlite3_enable_shared_cache,

  120388.   sqlite3_errcode,

  120389.   sqlite3_errmsg,

  120390.   sqlite3_errmsg16,

  120391.   sqlite3_exec,

  120392. #ifndef SQLITE_OMIT_DEPRECATED

  120393.   sqlite3_expired,

  120394. #else

  120395.   0,

  120396. #endif

  120397.   sqlite3_finalize,

  120398.   sqlite3_free,

  120399.   sqlite3_free_table,

  120400.   sqlite3_get_autocommit,

  120401.   sqlite3_get_auxdata,

  120402.   sqlite3_get_table,

  120403.   0,     /* Was sqlite3_global_recover(), but that function is deprecated */

  120404.   sqlite3_interrupt,

  120405.   sqlite3_last_insert_rowid,

  120406.   sqlite3_libversion,

  120407.   sqlite3_libversion_number,

  120408.   sqlite3_malloc,

  120409.   sqlite3_mprintf,

  120410.   sqlite3_open,

  120411.   sqlite3_open16,

  120412.   sqlite3_prepare,

  120413.   sqlite3_prepare16,

  120414.   sqlite3_profile,

  120415.   sqlite3_progress_handler,

  120416.   sqlite3_realloc,

  120417.   sqlite3_reset,

  120418.   sqlite3_result_blob,

  120419.   sqlite3_result_double,

  120420.   sqlite3_result_error,

  120421.   sqlite3_result_error16,

  120422.   sqlite3_result_int,

  120423.   sqlite3_result_int64,

  120424.   sqlite3_result_null,

  120425.   sqlite3_result_text,

  120426.   sqlite3_result_text16,

  120427.   sqlite3_result_text16be,

  120428.   sqlite3_result_text16le,

  120429.   sqlite3_result_value,

  120430.   sqlite3_rollback_hook,

  120431.   sqlite3_set_authorizer,

  120432.   sqlite3_set_auxdata,

  120433.   sqlite3_snprintf,

  120434.   sqlite3_step,

  120435.   sqlite3_table_column_metadata,

  120436. #ifndef SQLITE_OMIT_DEPRECATED

  120437.   sqlite3_thread_cleanup,

  120438. #else

  120439.   0,

  120440. #endif

  120441.   sqlite3_total_changes,

  120442.   sqlite3_trace,

  120443. #ifndef SQLITE_OMIT_DEPRECATED

  120444.   sqlite3_transfer_bindings,

  120445. #else

  120446.   0,

  120447. #endif

  120448.   sqlite3_update_hook,

  120449.   sqlite3_user_data,

  120450.   sqlite3_value_blob,

  120451.   sqlite3_value_bytes,

  120452.   sqlite3_value_bytes16,

  120453.   sqlite3_value_double,

  120454.   sqlite3_value_int,

  120455.   sqlite3_value_int64,

  120456.   sqlite3_value_numeric_type,

  120457.   sqlite3_value_text,

  120458.   sqlite3_value_text16,

  120459.   sqlite3_value_text16be,

  120460.   sqlite3_value_text16le,

  120461.   sqlite3_value_type,

  120462.   sqlite3_vmprintf,

  120463.   /*

  120464.   ** The original API set ends here.  All extensions can call any

  120465.   ** of the APIs above provided that the pointer is not NULL.  But

  120466.   ** before calling APIs that follow, extension should check the

  120467.   ** sqlite3_libversion_number() to make sure they are dealing with

  120468.   ** a library that is new enough to support that API.

  120469.   *************************************************************************

  120470.   */

  120471.   sqlite3_overload_function,

  120472. 

  120473.   /*

  120474.   ** Added after 3.3.13

  120475.   */

  120476.   sqlite3_prepare_v2,

  120477.   sqlite3_prepare16_v2,

  120478.   sqlite3_clear_bindings,

  120479. 

  120480.   /*

  120481.   ** Added for 3.4.1

  120482.   */

  120483.   sqlite3_create_module_v2,

  120484. 

  120485.   /*

  120486.   ** Added for 3.5.0

  120487.   */

  120488.   sqlite3_bind_zeroblob,

  120489.   sqlite3_blob_bytes,

  120490.   sqlite3_blob_close,

  120491.   sqlite3_blob_open,

  120492.   sqlite3_blob_read,

  120493.   sqlite3_blob_write,

  120494.   sqlite3_create_collation_v2,

  120495.   sqlite3_file_control,

  120496.   sqlite3_memory_highwater,

  120497.   sqlite3_memory_used,

  120498. #ifdef SQLITE_MUTEX_OMIT

  120499.   0, 

  120500.   0, 

  120501.   0,

  120502.   0,

  120503.   0,

  120504. #else

  120505.   sqlite3_mutex_alloc,

  120506.   sqlite3_mutex_enter,

  120507.   sqlite3_mutex_free,

  120508.   sqlite3_mutex_leave,

  120509.   sqlite3_mutex_try,

  120510. #endif

  120511.   sqlite3_open_v2,

  120512.   sqlite3_release_memory,

  120513.   sqlite3_result_error_nomem,

  120514.   sqlite3_result_error_toobig,

  120515.   sqlite3_sleep,

  120516.   sqlite3_soft_heap_limit,

  120517.   sqlite3_vfs_find,

  120518.   sqlite3_vfs_register,

  120519.   sqlite3_vfs_unregister,

  120520. 

  120521.   /*

  120522.   ** Added for 3.5.8

  120523.   */

  120524.   sqlite3_threadsafe,

  120525.   sqlite3_result_zeroblob,

  120526.   sqlite3_result_error_code,

  120527.   sqlite3_test_control,

  120528.   sqlite3_randomness,

  120529.   sqlite3_context_db_handle,

  120530. 

  120531.   /*

  120532.   ** Added for 3.6.0

  120533.   */

  120534.   sqlite3_extended_result_codes,

  120535.   sqlite3_limit,

  120536.   sqlite3_next_stmt,

  120537.   sqlite3_sql,

  120538.   sqlite3_status,

  120539. 

  120540.   /*

  120541.   ** Added for 3.7.4

  120542.   */

  120543.   sqlite3_backup_finish,

  120544.   sqlite3_backup_init,

  120545.   sqlite3_backup_pagecount,

  120546.   sqlite3_backup_remaining,

  120547.   sqlite3_backup_step,

  120548. #ifndef SQLITE_OMIT_COMPILEOPTION_DIAGS

  120549.   sqlite3_compileoption_get,

  120550.   sqlite3_compileoption_used,

  120551. #else

  120552.   0,

  120553.   0,

  120554. #endif

  120555.   sqlite3_create_function_v2,

  120556.   sqlite3_db_config,

  120557.   sqlite3_db_mutex,

  120558.   sqlite3_db_status,

  120559.   sqlite3_extended_errcode,

  120560.   sqlite3_log,

  120561.   sqlite3_soft_heap_limit64,

  120562.   sqlite3_sourceid,

  120563.   sqlite3_stmt_status,

  120564.   sqlite3_strnicmp,

  120565. #ifdef SQLITE_ENABLE_UNLOCK_NOTIFY

  120566.   sqlite3_unlock_notify,

  120567. #else

  120568.   0,

  120569. #endif

  120570. #ifndef SQLITE_OMIT_WAL

  120571.   sqlite3_wal_autocheckpoint,

  120572.   sqlite3_wal_checkpoint,

  120573.   sqlite3_wal_hook,

  120574. #else

  120575.   0,

  120576.   0,

  120577.   0,

  120578. #endif

  120579.   sqlite3_blob_reopen,

  120580.   sqlite3_vtab_config,

  120581.   sqlite3_vtab_on_conflict,

  120582.   sqlite3_close_v2,

  120583.   sqlite3_db_filename,

  120584.   sqlite3_db_readonly,

  120585.   sqlite3_db_release_memory,

  120586.   sqlite3_errstr,

  120587.   sqlite3_stmt_busy,

  120588.   sqlite3_stmt_readonly,

  120589.   sqlite3_stricmp,

  120590.   sqlite3_uri_boolean,

  120591.   sqlite3_uri_int64,

  120592.   sqlite3_uri_parameter,

  120593.   sqlite3_vsnprintf,

  120594.   sqlite3_wal_checkpoint_v2,

  120595.   /* Version 3.8.7 and later */

  120596.   sqlite3_auto_extension,

  120597.   sqlite3_bind_blob64,

  120598.   sqlite3_bind_text64,

  120599.   sqlite3_cancel_auto_extension,

  120600.   sqlite3_load_extension,

  120601.   sqlite3_malloc64,

  120602.   sqlite3_msize,

  120603.   sqlite3_realloc64,

  120604.   sqlite3_reset_auto_extension,

  120605.   sqlite3_result_blob64,

  120606.   sqlite3_result_text64,

  120607.   sqlite3_strglob,

  120608.   /* Version 3.8.11 and later */

  120609.   (sqlite3_value*(*)(const sqlite3_value*))sqlite3_value_dup,

  120610.   sqlite3_value_free,

  120611.   sqlite3_result_zeroblob64,

  120612.   sqlite3_bind_zeroblob64,

  120613.   /* Version 3.9.0 and later */

  120614.   sqlite3_value_subtype,

  120615.   sqlite3_result_subtype,

  120616.   /* Version 3.10.0 and later */

  120617.   sqlite3_status64,

  120618.   sqlite3_strlike,

  120619.   sqlite3_db_cacheflush,

  120620.   /* Version 3.12.0 and later */

  120621.   sqlite3_system_errno,

  120622.   /* Version 3.14.0 and later */

  120623.   sqlite3_trace_v2,

  120624.   sqlite3_expanded_sql,

  120625.   /* Version 3.18.0 and later */

  120626.   sqlite3_set_last_insert_rowid,

  120627.   /* Version 3.20.0 and later */

  120628.   sqlite3_prepare_v3,

  120629.   sqlite3_prepare16_v3,

  120630.   sqlite3_bind_pointer,

  120631.   sqlite3_result_pointer,

  120632.   sqlite3_value_pointer,

  120633.   /* Version 3.22.0 and later */

  120634.   sqlite3_vtab_nochange,

  120635.   sqlite3_value_nochange,

  120636.   sqlite3_vtab_collation,

  120637.   /* Version 3.24.0 and later */

  120638.   sqlite3_keyword_count,

  120639.   sqlite3_keyword_name,

  120640.   sqlite3_keyword_check,

  120641.   sqlite3_str_new,

  120642.   sqlite3_str_finish,

  120643.   sqlite3_str_appendf,

  120644.   sqlite3_str_vappendf,

  120645.   sqlite3_str_append,

  120646.   sqlite3_str_appendall,

  120647.   sqlite3_str_appendchar,

  120648.   sqlite3_str_reset,

  120649.   sqlite3_str_errcode,

  120650.   sqlite3_str_length,

  120651.   sqlite3_str_value,

  120652.   /* Version 3.25.0 and later */

  120653.   sqlite3_create_window_function,

  120654.   /* Version 3.26.0 and later */

  120655. #ifdef SQLITE_ENABLE_NORMALIZE

  120656.   sqlite3_normalized_sql,

  120657. #else

  120658.   0,

  120659. #endif

  120660.   /* Version 3.28.0 and later */

  120661.   sqlite3_stmt_isexplain,

  120662.   sqlite3_value_frombind

  120663. };

  120664. 

  120665. /*

  120666. ** Attempt to load an SQLite extension library contained in the file

  120667. ** zFile.  The entry point is zProc.  zProc may be 0 in which case a

  120668. ** default entry point name (sqlite3_extension_init) is used.  Use

  120669. ** of the default name is recommended.

  120670. **

  120671. ** Return SQLITE_OK on success and SQLITE_ERROR if something goes wrong.

  120672. **

  120673. ** If an error occurs and pzErrMsg is not 0, then fill *pzErrMsg with 

  120674. ** error message text.  The calling function should free this memory

  120675. ** by calling sqlite3DbFree(db, ).

  120676. */

  120677. static int sqlite3LoadExtension(

  120678.   sqlite3 *db,          /* Load the extension into this database connection */

  120679.   const char *zFile,    /* Name of the shared library containing extension */

  120680.   const char *zProc,    /* Entry point.  Use "sqlite3_extension_init" if 0 */

  120681.   char **pzErrMsg       /* Put error message here if not 0 */

  120682. ){

  120683.   sqlite3_vfs *pVfs = db->pVfs;

  120684.   void *handle;

  120685.   sqlite3_loadext_entry xInit;

  120686.   char *zErrmsg = 0;

  120687.   const char *zEntry;

  120688.   char *zAltEntry = 0;

  120689.   void **aHandle;

  120690.   u64 nMsg = 300 + sqlite3Strlen30(zFile);

  120691.   int ii;

  120692.   int rc;

  120693. 

  120694.   /* Shared library endings to try if zFile cannot be loaded as written */

  120695.   static const char *azEndings[] = {

  120696. #if SQLITE_OS_WIN

  120697.      "dll"   

  120698. #elif defined(__APPLE__)

  120699.      "dylib"

  120700. #else

  120701.      "so"

  120702. #endif

  120703.   };

  120704. 

  120705. 

  120706.   if( pzErrMsg ) *pzErrMsg = 0;

  120707. 

  120708.   /* Ticket #1863.  To avoid a creating security problems for older

  120709.   ** applications that relink against newer versions of SQLite, the

  120710.   ** ability to run load_extension is turned off by default.  One

  120711.   ** must call either sqlite3_enable_load_extension(db) or

  120712.   ** sqlite3_db_config(db, SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION, 1, 0)

  120713.   ** to turn on extension loading.

  120714.   */

  120715.   if( (db->flags & SQLITE_LoadExtension)==0 ){

  120716.     if( pzErrMsg ){

  120717.       *pzErrMsg = sqlite3_mprintf("not authorized");

  120718.     }

  120719.     return SQLITE_ERROR;

  120720.   }

  120721. 

  120722.   zEntry = zProc ? zProc : "sqlite3_extension_init";

  120723. 

  120724.   handle = sqlite3OsDlOpen(pVfs, zFile);

  120725. #if SQLITE_OS_UNIX || SQLITE_OS_WIN

  120726.   for(ii=0; ii<ArraySize(azEndings) && handle==0; ii++){

  120727.     char *zAltFile = sqlite3_mprintf("%s.%s", zFile, azEndings[ii]);

  120728.     if( zAltFile==0 ) return SQLITE_NOMEM_BKPT;

  120729.     handle = sqlite3OsDlOpen(pVfs, zAltFile);

  120730.     sqlite3_free(zAltFile);

  120731.   }

  120732. #endif

  120733.   if( handle==0 ){

  120734.     if( pzErrMsg ){

  120735.       *pzErrMsg = zErrmsg = sqlite3_malloc64(nMsg);

  120736.       if( zErrmsg ){

  120737.         sqlite3_snprintf(nMsg, zErrmsg, 

  120738.             "unable to open shared library [%s]", zFile);

  120739.         sqlite3OsDlError(pVfs, nMsg-1, zErrmsg);

  120740.       }

  120741.     }

  120742.     return SQLITE_ERROR;

  120743.   }

  120744.   xInit = (sqlite3_loadext_entry)sqlite3OsDlSym(pVfs, handle, zEntry);

  120745. 

  120746.   /* If no entry point was specified and the default legacy

  120747.   ** entry point name "sqlite3_extension_init" was not found, then

  120748.   ** construct an entry point name "sqlite3_X_init" where the X is

  120749.   ** replaced by the lowercase value of every ASCII alphabetic 

  120750.   ** character in the filename after the last "/" upto the first ".",

  120751.   ** and eliding the first three characters if they are "lib".  

  120752.   ** Examples:

  120753.   **

  120754.   **    /usr/local/lib/libExample5.4.3.so ==>  sqlite3_example_init

  120755.   **    C:/lib/mathfuncs.dll              ==>  sqlite3_mathfuncs_init

  120756.   */

  120757.   if( xInit==0 && zProc==0 ){

  120758.     int iFile, iEntry, c;

  120759.     int ncFile = sqlite3Strlen30(zFile);

  120760.     zAltEntry = sqlite3_malloc64(ncFile+30);

  120761.     if( zAltEntry==0 ){

  120762.       sqlite3OsDlClose(pVfs, handle);

  120763.       return SQLITE_NOMEM_BKPT;

  120764.     }

  120765.     memcpy(zAltEntry, "sqlite3_", 8);

  120766.     for(iFile=ncFile-1; iFile>=0 && zFile[iFile]!='/'; iFile--){}

  120767.     iFile++;

  120768.     if( sqlite3_strnicmp(zFile+iFile, "lib", 3)==0 ) iFile += 3;

  120769.     for(iEntry=8; (c = zFile[iFile])!=0 && c!='.'; iFile++){

  120770.       if( sqlite3Isalpha(c) ){

  120771.         zAltEntry[iEntry++] = (char)sqlite3UpperToLower[(unsigned)c];

  120772.       }

  120773.     }

  120774.     memcpy(zAltEntry+iEntry, "_init", 6);

  120775.     zEntry = zAltEntry;

  120776.     xInit = (sqlite3_loadext_entry)sqlite3OsDlSym(pVfs, handle, zEntry);

  120777.   }

  120778.   if( xInit==0 ){

  120779.     if( pzErrMsg ){

  120780.       nMsg += sqlite3Strlen30(zEntry);

  120781.       *pzErrMsg = zErrmsg = sqlite3_malloc64(nMsg);

  120782.       if( zErrmsg ){

  120783.         sqlite3_snprintf(nMsg, zErrmsg,

  120784.             "no entry point [%s] in shared library [%s]", zEntry, zFile);

  120785.         sqlite3OsDlError(pVfs, nMsg-1, zErrmsg);

  120786.       }

  120787.     }

  120788.     sqlite3OsDlClose(pVfs, handle);

  120789.     sqlite3_free(zAltEntry);

  120790.     return SQLITE_ERROR;

  120791.   }

  120792.   sqlite3_free(zAltEntry);

  120793.   rc = xInit(db, &zErrmsg, &sqlite3Apis);

  120794.   if( rc ){

  120795.     if( rc==SQLITE_OK_LOAD_PERMANENTLY ) return SQLITE_OK;

  120796.     if( pzErrMsg ){

  120797.       *pzErrMsg = sqlite3_mprintf("error during initialization: %s", zErrmsg);

  120798.     }

  120799.     sqlite3_free(zErrmsg);

  120800.     sqlite3OsDlClose(pVfs, handle);

  120801.     return SQLITE_ERROR;

  120802.   }

  120803. 

  120804.   /* Append the new shared library handle to the db->aExtension array. */

  120805.   aHandle = sqlite3DbMallocZero(db, sizeof(handle)*(db->nExtension+1));

  120806.   if( aHandle==0 ){

  120807.     return SQLITE_NOMEM_BKPT;

  120808.   }

  120809.   if( db->nExtension>0 ){

  120810.     memcpy(aHandle, db->aExtension, sizeof(handle)*db->nExtension);

  120811.   }

  120812.   sqlite3DbFree(db, db->aExtension);

  120813.   db->aExtension = aHandle;

  120814. 

  120815.   db->aExtension[db->nExtension++] = handle;

  120816.   return SQLITE_OK;

  120817. }

  120818. SQLITE_API int sqlite3_load_extension(

  120819.   sqlite3 *db,          /* Load the extension into this database connection */

  120820.   const char *zFile,    /* Name of the shared library containing extension */

  120821.   const char *zProc,    /* Entry point.  Use "sqlite3_extension_init" if 0 */

  120822.   char **pzErrMsg       /* Put error message here if not 0 */

  120823. ){

  120824.   int rc;

  120825.   sqlite3_mutex_enter(db->mutex);

  120826.   rc = sqlite3LoadExtension(db, zFile, zProc, pzErrMsg);

  120827.   rc = sqlite3ApiExit(db, rc);

  120828.   sqlite3_mutex_leave(db->mutex);

  120829.   return rc;

  120830. }

  120831. 

  120832. /*

  120833. ** Call this routine when the database connection is closing in order

  120834. ** to clean up loaded extensions

  120835. */

  120836. SQLITE_PRIVATE void sqlite3CloseExtensions(sqlite3 *db){

  120837.   int i;

  120838.   assert( sqlite3_mutex_held(db->mutex) );

  120839.   for(i=0; i<db->nExtension; i++){

  120840.     sqlite3OsDlClose(db->pVfs, db->aExtension[i]);

  120841.   }

  120842.   sqlite3DbFree(db, db->aExtension);

  120843. }

  120844. 

  120845. /*

  120846. ** Enable or disable extension loading.  Extension loading is disabled by

  120847. ** default so as not to open security holes in older applications.

  120848. */

  120849. SQLITE_API int sqlite3_enable_load_extension(sqlite3 *db, int onoff){

  120850.   sqlite3_mutex_enter(db->mutex);

  120851.   if( onoff ){

  120852.     db->flags |= SQLITE_LoadExtension|SQLITE_LoadExtFunc;

  120853.   }else{

  120854.     db->flags &= ~(u64)(SQLITE_LoadExtension|SQLITE_LoadExtFunc);

  120855.   }

  120856.   sqlite3_mutex_leave(db->mutex);

  120857.   return SQLITE_OK;

  120858. }

  120859. 

  120860. #endif /* !defined(SQLITE_OMIT_LOAD_EXTENSION) */

  120861. 

  120862. /*

  120863. ** The following object holds the list of automatically loaded

  120864. ** extensions.

  120865. **

  120866. ** This list is shared across threads.  The SQLITE_MUTEX_STATIC_MASTER

  120867. ** mutex must be held while accessing this list.

  120868. */

  120869. typedef struct sqlite3AutoExtList sqlite3AutoExtList;

  120870. static SQLITE_WSD struct sqlite3AutoExtList {

  120871.   u32 nExt;              /* Number of entries in aExt[] */          

  120872.   void (**aExt)(void);   /* Pointers to the extension init functions */

  120873. } sqlite3Autoext = { 0, 0 };

  120874. 

  120875. /* The "wsdAutoext" macro will resolve to the autoextension

  120876. ** state vector.  If writable static data is unsupported on the target,

  120877. ** we have to locate the state vector at run-time.  In the more common

  120878. ** case where writable static data is supported, wsdStat can refer directly

  120879. ** to the "sqlite3Autoext" state vector declared above.

  120880. */

  120881. #ifdef SQLITE_OMIT_WSD

  120882. # define wsdAutoextInit \

  120883.   sqlite3AutoExtList *x = &GLOBAL(sqlite3AutoExtList,sqlite3Autoext)

  120884. # define wsdAutoext x[0]

  120885. #else

  120886. # define wsdAutoextInit

  120887. # define wsdAutoext sqlite3Autoext

  120888. #endif

  120889. 

  120890. 

  120891. /*

  120892. ** Register a statically linked extension that is automatically

  120893. ** loaded by every new database connection.

  120894. */

  120895. SQLITE_API int sqlite3_auto_extension(

  120896.   void (*xInit)(void)

  120897. ){

  120898.   int rc = SQLITE_OK;

  120899. #ifndef SQLITE_OMIT_AUTOINIT

  120900.   rc = sqlite3_initialize();

  120901.   if( rc ){

  120902.     return rc;

  120903.   }else

  120904. #endif

  120905.   {

  120906.     u32 i;

  120907. #if SQLITE_THREADSAFE

  120908.     sqlite3_mutex *mutex = sqlite3MutexAlloc(SQLITE_MUTEX_STATIC_MASTER);

  120909. #endif

  120910.     wsdAutoextInit;

  120911.     sqlite3_mutex_enter(mutex);

  120912.     for(i=0; i<wsdAutoext.nExt; i++){

  120913.       if( wsdAutoext.aExt[i]==xInit ) break;

  120914.     }

  120915.     if( i==wsdAutoext.nExt ){

  120916.       u64 nByte = (wsdAutoext.nExt+1)*sizeof(wsdAutoext.aExt[0]);

  120917.       void (**aNew)(void);

  120918.       aNew = sqlite3_realloc64(wsdAutoext.aExt, nByte);

  120919.       if( aNew==0 ){

  120920.         rc = SQLITE_NOMEM_BKPT;

  120921.       }else{

  120922.         wsdAutoext.aExt = aNew;

  120923.         wsdAutoext.aExt[wsdAutoext.nExt] = xInit;

  120924.         wsdAutoext.nExt++;

  120925.       }

  120926.     }

  120927.     sqlite3_mutex_leave(mutex);

  120928.     assert( (rc&0xff)==rc );

  120929.     return rc;

  120930.   }

  120931. }

  120932. 

  120933. /*

  120934. ** Cancel a prior call to sqlite3_auto_extension.  Remove xInit from the

  120935. ** set of routines that is invoked for each new database connection, if it

  120936. ** is currently on the list.  If xInit is not on the list, then this

  120937. ** routine is a no-op.

  120938. **

  120939. ** Return 1 if xInit was found on the list and removed.  Return 0 if xInit

  120940. ** was not on the list.

  120941. */

  120942. SQLITE_API int sqlite3_cancel_auto_extension(

  120943.   void (*xInit)(void)

  120944. ){

  120945. #if SQLITE_THREADSAFE

  120946.   sqlite3_mutex *mutex = sqlite3MutexAlloc(SQLITE_MUTEX_STATIC_MASTER);

  120947. #endif

  120948.   int i;

  120949.   int n = 0;

  120950.   wsdAutoextInit;

  120951.   sqlite3_mutex_enter(mutex);

  120952.   for(i=(int)wsdAutoext.nExt-1; i>=0; i--){

  120953.     if( wsdAutoext.aExt[i]==xInit ){

  120954.       wsdAutoext.nExt--;

  120955.       wsdAutoext.aExt[i] = wsdAutoext.aExt[wsdAutoext.nExt];

  120956.       n++;

  120957.       break;

  120958.     }

  120959.   }

  120960.   sqlite3_mutex_leave(mutex);

  120961.   return n;

  120962. }

  120963. 

  120964. /*

  120965. ** Reset the automatic extension loading mechanism.

  120966. */

  120967. SQLITE_API void sqlite3_reset_auto_extension(void){

  120968. #ifndef SQLITE_OMIT_AUTOINIT

  120969.   if( sqlite3_initialize()==SQLITE_OK )

  120970. #endif

  120971.   {

  120972. #if SQLITE_THREADSAFE

  120973.     sqlite3_mutex *mutex = sqlite3MutexAlloc(SQLITE_MUTEX_STATIC_MASTER);

  120974. #endif

  120975.     wsdAutoextInit;

  120976.     sqlite3_mutex_enter(mutex);

  120977.     sqlite3_free(wsdAutoext.aExt);

  120978.     wsdAutoext.aExt = 0;

  120979.     wsdAutoext.nExt = 0;

  120980.     sqlite3_mutex_leave(mutex);

  120981.   }

  120982. }

  120983. 

  120984. /*

  120985. ** Load all automatic extensions.

  120986. **

  120987. ** If anything goes wrong, set an error in the database connection.

  120988. */

  120989. SQLITE_PRIVATE void sqlite3AutoLoadExtensions(sqlite3 *db){

  120990.   u32 i;

  120991.   int go = 1;

  120992.   int rc;

  120993.   sqlite3_loadext_entry xInit;

  120994. 

  120995.   wsdAutoextInit;

  120996.   if( wsdAutoext.nExt==0 ){

  120997.     /* Common case: early out without every having to acquire a mutex */

  120998.     return;

  120999.   }

  121000.   for(i=0; go; i++){

  121001.     char *zErrmsg;

  121002. #if SQLITE_THREADSAFE

  121003.     sqlite3_mutex *mutex = sqlite3MutexAlloc(SQLITE_MUTEX_STATIC_MASTER);

  121004. #endif

  121005. #ifdef SQLITE_OMIT_LOAD_EXTENSION

  121006.     const sqlite3_api_routines *pThunk = 0;

  121007. #else

  121008.     const sqlite3_api_routines *pThunk = &sqlite3Apis;

  121009. #endif

  121010.     sqlite3_mutex_enter(mutex);

  121011.     if( i>=wsdAutoext.nExt ){

  121012.       xInit = 0;

  121013.       go = 0;

  121014.     }else{

  121015.       xInit = (sqlite3_loadext_entry)wsdAutoext.aExt[i];

  121016.     }

  121017.     sqlite3_mutex_leave(mutex);

  121018.     zErrmsg = 0;

  121019.     if( xInit && (rc = xInit(db, &zErrmsg, pThunk))!=0 ){

  121020.       sqlite3ErrorWithMsg(db, rc,

  121021.             "automatic extension loading failed: %s", zErrmsg);

  121022.       go = 0;

  121023.     }

  121024.     sqlite3_free(zErrmsg);

  121025.   }

  121026. }

  121027. 

  121028. /************** End of loadext.c *********************************************/

  121029. /************** Begin file pragma.c ******************************************/

  121030. /*

  121031. ** 2003 April 6

  121032. **

  121033. ** The author disclaims copyright to this source code.  In place of

  121034. ** a legal notice, here is a blessing:

  121035. **

  121036. **    May you do good and not evil.

  121037. **    May you find forgiveness for yourself and forgive others.

  121038. **    May you share freely, never taking more than you give.

  121039. **

  121040. *************************************************************************

  121041. ** This file contains code used to implement the PRAGMA command.

  121042. */

  121043. /* #include "sqliteInt.h" */

  121044. 

  121045. #if !defined(SQLITE_ENABLE_LOCKING_STYLE)

  121046. #  if defined(__APPLE__)

  121047. #    define SQLITE_ENABLE_LOCKING_STYLE 1

  121048. #  else

  121049. #    define SQLITE_ENABLE_LOCKING_STYLE 0

  121050. #  endif

  121051. #endif

  121052. 

  121053. /***************************************************************************

  121054. ** The "pragma.h" include file is an automatically generated file that

  121055. ** that includes the PragType_XXXX macro definitions and the aPragmaName[]

  121056. ** object.  This ensures that the aPragmaName[] table is arranged in

  121057. ** lexicographical order to facility a binary search of the pragma name.

  121058. ** Do not edit pragma.h directly.  Edit and rerun the script in at 

  121059. ** ../tool/mkpragmatab.tcl. */

  121060. /************** Include pragma.h in the middle of pragma.c *******************/

  121061. /************** Begin file pragma.h ******************************************/

  121062. /* DO NOT EDIT!

  121063. ** This file is automatically generated by the script at

  121064. ** ../tool/mkpragmatab.tcl.  To update the set of pragmas, edit

  121065. ** that script and rerun it.

  121066. */

  121067. 

  121068. /* The various pragma types */

  121069. #define PragTyp_HEADER_VALUE                   0

  121070. #define PragTyp_AUTO_VACUUM                    1

  121071. #define PragTyp_FLAG                           2

  121072. #define PragTyp_BUSY_TIMEOUT                   3

  121073. #define PragTyp_CACHE_SIZE                     4

  121074. #define PragTyp_CACHE_SPILL                    5

  121075. #define PragTyp_CASE_SENSITIVE_LIKE            6

  121076. #define PragTyp_COLLATION_LIST                 7

  121077. #define PragTyp_COMPILE_OPTIONS                8

  121078. #define PragTyp_DATA_STORE_DIRECTORY           9

  121079. #define PragTyp_DATABASE_LIST                 10

  121080. #define PragTyp_DEFAULT_CACHE_SIZE            11

  121081. #define PragTyp_ENCODING                      12

  121082. #define PragTyp_FOREIGN_KEY_CHECK             13

  121083. #define PragTyp_FOREIGN_KEY_LIST              14

  121084. #define PragTyp_FUNCTION_LIST                 15

  121085. #define PragTyp_INCREMENTAL_VACUUM            16

  121086. #define PragTyp_INDEX_INFO                    17

  121087. #define PragTyp_INDEX_LIST                    18

  121088. #define PragTyp_INTEGRITY_CHECK               19

  121089. #define PragTyp_JOURNAL_MODE                  20

  121090. #define PragTyp_JOURNAL_SIZE_LIMIT            21

  121091. #define PragTyp_LOCK_PROXY_FILE               22

  121092. #define PragTyp_LOCKING_MODE                  23

  121093. #define PragTyp_PAGE_COUNT                    24

  121094. #define PragTyp_MMAP_SIZE                     25

  121095. #define PragTyp_MODULE_LIST                   26

  121096. #define PragTyp_OPTIMIZE                      27

  121097. #define PragTyp_PAGE_SIZE                     28

  121098. #define PragTyp_PRAGMA_LIST                   29

  121099. #define PragTyp_SECURE_DELETE                 30

  121100. #define PragTyp_SHRINK_MEMORY                 31

  121101. #define PragTyp_SOFT_HEAP_LIMIT               32

  121102. #define PragTyp_SYNCHRONOUS                   33

  121103. #define PragTyp_TABLE_INFO                    34

  121104. #define PragTyp_TEMP_STORE                    35

  121105. #define PragTyp_TEMP_STORE_DIRECTORY          36

  121106. #define PragTyp_THREADS                       37

  121107. #define PragTyp_WAL_AUTOCHECKPOINT            38

  121108. #define PragTyp_WAL_CHECKPOINT                39

  121109. #define PragTyp_ACTIVATE_EXTENSIONS           40

  121110. #define PragTyp_KEY                           41

  121111. #define PragTyp_LOCK_STATUS                   42

  121112. #define PragTyp_STATS                         43

  121113. 

  121114. /* Property flags associated with various pragma. */

  121115. #define PragFlg_NeedSchema 0x01 /* Force schema load before running */

  121116. #define PragFlg_NoColumns  0x02 /* OP_ResultRow called with zero columns */

  121117. #define PragFlg_NoColumns1 0x04 /* zero columns if RHS argument is present */

  121118. #define PragFlg_ReadOnly   0x08 /* Read-only HEADER_VALUE */

  121119. #define PragFlg_Result0    0x10 /* Acts as query when no argument */

  121120. #define PragFlg_Result1    0x20 /* Acts as query when has one argument */

  121121. #define PragFlg_SchemaOpt  0x40 /* Schema restricts name search if present */

  121122. #define PragFlg_SchemaReq  0x80 /* Schema required - "main" is default */

  121123. 

  121124. /* Names of columns for pragmas that return multi-column result

  121125. ** or that return single-column results where the name of the

  121126. ** result column is different from the name of the pragma

  121127. */

  121128. static const char *const pragCName[] = {

  121129.   /*   0 */ "id",          /* Used by: foreign_key_list */

  121130.   /*   1 */ "seq",        

  121131.   /*   2 */ "table",      

  121132.   /*   3 */ "from",       

  121133.   /*   4 */ "to",         

  121134.   /*   5 */ "on_update",  

  121135.   /*   6 */ "on_delete",  

  121136.   /*   7 */ "match",      

  121137.   /*   8 */ "cid",         /* Used by: table_xinfo */

  121138.   /*   9 */ "name",       

  121139.   /*  10 */ "type",       

  121140.   /*  11 */ "notnull",    

  121141.   /*  12 */ "dflt_value", 

  121142.   /*  13 */ "pk",         

  121143.   /*  14 */ "hidden",     

  121144.                            /* table_info reuses 8 */

  121145.   /*  15 */ "seqno",       /* Used by: index_xinfo */

  121146.   /*  16 */ "cid",        

  121147.   /*  17 */ "name",       

  121148.   /*  18 */ "desc",       

  121149.   /*  19 */ "coll",       

  121150.   /*  20 */ "key",        

  121151.   /*  21 */ "tbl",         /* Used by: stats */

  121152.   /*  22 */ "idx",        

  121153.   /*  23 */ "wdth",       

  121154.   /*  24 */ "hght",       

  121155.   /*  25 */ "flgs",       

  121156.   /*  26 */ "seq",         /* Used by: index_list */

  121157.   /*  27 */ "name",       

  121158.   /*  28 */ "unique",     

  121159.   /*  29 */ "origin",     

  121160.   /*  30 */ "partial",    

  121161.   /*  31 */ "table",       /* Used by: foreign_key_check */

  121162.   /*  32 */ "rowid",      

  121163.   /*  33 */ "parent",     

  121164.   /*  34 */ "fkid",       

  121165.                            /* index_info reuses 15 */

  121166.   /*  35 */ "seq",         /* Used by: database_list */

  121167.   /*  36 */ "name",       

  121168.   /*  37 */ "file",       

  121169.   /*  38 */ "busy",        /* Used by: wal_checkpoint */

  121170.   /*  39 */ "log",        

  121171.   /*  40 */ "checkpointed",

  121172.   /*  41 */ "name",        /* Used by: function_list */

  121173.   /*  42 */ "builtin",    

  121174.                            /* collation_list reuses 26 */

  121175.   /*  43 */ "database",    /* Used by: lock_status */

  121176.   /*  44 */ "status",     

  121177.   /*  45 */ "cache_size",  /* Used by: default_cache_size */

  121178.                            /* module_list pragma_list reuses 9 */

  121179.   /*  46 */ "timeout",     /* Used by: busy_timeout */

  121180. };

  121181. 

  121182. /* Definitions of all built-in pragmas */

  121183. typedef struct PragmaName {

  121184.   const char *const zName; /* Name of pragma */

  121185.   u8 ePragTyp;             /* PragTyp_XXX value */

  121186.   u8 mPragFlg;             /* Zero or more PragFlg_XXX values */

  121187.   u8 iPragCName;           /* Start of column names in pragCName[] */

  121188.   u8 nPragCName;           /* Num of col names. 0 means use pragma name */

  121189.   u64 iArg;                /* Extra argument */

  121190. } PragmaName;

  121191. static const PragmaName aPragmaName[] = {

  121192. #if defined(SQLITE_HAS_CODEC) || defined(SQLITE_ENABLE_CEROD)

  121193.  {/* zName:     */ "activate_extensions",

  121194.   /* ePragTyp:  */ PragTyp_ACTIVATE_EXTENSIONS,

  121195.   /* ePragFlg:  */ 0,

  121196.   /* ColNames:  */ 0, 0,

  121197.   /* iArg:      */ 0 },

  121198. #endif

  121199. #if !defined(SQLITE_OMIT_SCHEMA_VERSION_PRAGMAS)

  121200.  {/* zName:     */ "application_id",

  121201.   /* ePragTyp:  */ PragTyp_HEADER_VALUE,

  121202.   /* ePragFlg:  */ PragFlg_NoColumns1|PragFlg_Result0,

  121203.   /* ColNames:  */ 0, 0,

  121204.   /* iArg:      */ BTREE_APPLICATION_ID },

  121205. #endif

  121206. #if !defined(SQLITE_OMIT_AUTOVACUUM)

  121207.  {/* zName:     */ "auto_vacuum",

  121208.   /* ePragTyp:  */ PragTyp_AUTO_VACUUM,

  121209.   /* ePragFlg:  */ PragFlg_NeedSchema|PragFlg_Result0|PragFlg_SchemaReq|PragFlg_NoColumns1,

  121210.   /* ColNames:  */ 0, 0,

  121211.   /* iArg:      */ 0 },

  121212. #endif

  121213. #if !defined(SQLITE_OMIT_FLAG_PRAGMAS)

  121214. #if !defined(SQLITE_OMIT_AUTOMATIC_INDEX)

  121215.  {/* zName:     */ "automatic_index",

  121216.   /* ePragTyp:  */ PragTyp_FLAG,

  121217.   /* ePragFlg:  */ PragFlg_Result0|PragFlg_NoColumns1,

  121218.   /* ColNames:  */ 0, 0,

  121219.   /* iArg:      */ SQLITE_AutoIndex },

  121220. #endif

  121221. #endif

  121222.  {/* zName:     */ "busy_timeout",

  121223.   /* ePragTyp:  */ PragTyp_BUSY_TIMEOUT,

  121224.   /* ePragFlg:  */ PragFlg_Result0,

  121225.   /* ColNames:  */ 46, 1,

  121226.   /* iArg:      */ 0 },

  121227. #if !defined(SQLITE_OMIT_PAGER_PRAGMAS)

  121228.  {/* zName:     */ "cache_size",

  121229.   /* ePragTyp:  */ PragTyp_CACHE_SIZE,

  121230.   /* ePragFlg:  */ PragFlg_NeedSchema|PragFlg_Result0|PragFlg_SchemaReq|PragFlg_NoColumns1,

  121231.   /* ColNames:  */ 0, 0,

  121232.   /* iArg:      */ 0 },

  121233. #endif

  121234. #if !defined(SQLITE_OMIT_FLAG_PRAGMAS)

  121235.  {/* zName:     */ "cache_spill",

  121236.   /* ePragTyp:  */ PragTyp_CACHE_SPILL,

  121237.   /* ePragFlg:  */ PragFlg_Result0|PragFlg_SchemaReq|PragFlg_NoColumns1,

  121238.   /* ColNames:  */ 0, 0,

  121239.   /* iArg:      */ 0 },

  121240. #endif

  121241. #if !defined(SQLITE_OMIT_CASE_SENSITIVE_LIKE_PRAGMA)

  121242.  {/* zName:     */ "case_sensitive_like",

  121243.   /* ePragTyp:  */ PragTyp_CASE_SENSITIVE_LIKE,

  121244.   /* ePragFlg:  */ PragFlg_NoColumns,

  121245.   /* ColNames:  */ 0, 0,

  121246.   /* iArg:      */ 0 },

  121247. #endif

  121248.  {/* zName:     */ "cell_size_check",

  121249.   /* ePragTyp:  */ PragTyp_FLAG,

  121250.   /* ePragFlg:  */ PragFlg_Result0|PragFlg_NoColumns1,

  121251.   /* ColNames:  */ 0, 0,

  121252.   /* iArg:      */ SQLITE_CellSizeCk },

  121253. #if !defined(SQLITE_OMIT_FLAG_PRAGMAS)

  121254.  {/* zName:     */ "checkpoint_fullfsync",

  121255.   /* ePragTyp:  */ PragTyp_FLAG,

  121256.   /* ePragFlg:  */ PragFlg_Result0|PragFlg_NoColumns1,

  121257.   /* ColNames:  */ 0, 0,

  121258.   /* iArg:      */ SQLITE_CkptFullFSync },

  121259. #endif

  121260. #if !defined(SQLITE_OMIT_SCHEMA_PRAGMAS)

  121261.  {/* zName:     */ "collation_list",

  121262.   /* ePragTyp:  */ PragTyp_COLLATION_LIST,

  121263.   /* ePragFlg:  */ PragFlg_Result0,

  121264.   /* ColNames:  */ 26, 2,

  121265.   /* iArg:      */ 0 },

  121266. #endif

  121267. #if !defined(SQLITE_OMIT_COMPILEOPTION_DIAGS)

  121268.  {/* zName:     */ "compile_options",

  121269.   /* ePragTyp:  */ PragTyp_COMPILE_OPTIONS,

  121270.   /* ePragFlg:  */ PragFlg_Result0,

  121271.   /* ColNames:  */ 0, 0,

  121272.   /* iArg:      */ 0 },

  121273. #endif

  121274. #if !defined(SQLITE_OMIT_FLAG_PRAGMAS)

  121275.  {/* zName:     */ "count_changes",

  121276.   /* ePragTyp:  */ PragTyp_FLAG,

  121277.   /* ePragFlg:  */ PragFlg_Result0|PragFlg_NoColumns1,

  121278.   /* ColNames:  */ 0, 0,

  121279.   /* iArg:      */ SQLITE_CountRows },

  121280. #endif

  121281. #if !defined(SQLITE_OMIT_PAGER_PRAGMAS) && SQLITE_OS_WIN

  121282.  {/* zName:     */ "data_store_directory",

  121283.   /* ePragTyp:  */ PragTyp_DATA_STORE_DIRECTORY,

  121284.   /* ePragFlg:  */ PragFlg_NoColumns1,

  121285.   /* ColNames:  */ 0, 0,

  121286.   /* iArg:      */ 0 },

  121287. #endif

  121288. #if !defined(SQLITE_OMIT_SCHEMA_VERSION_PRAGMAS)

  121289.  {/* zName:     */ "data_version",

  121290.   /* ePragTyp:  */ PragTyp_HEADER_VALUE,

  121291.   /* ePragFlg:  */ PragFlg_ReadOnly|PragFlg_Result0,

  121292.   /* ColNames:  */ 0, 0,

  121293.   /* iArg:      */ BTREE_DATA_VERSION },

  121294. #endif

  121295. #if !defined(SQLITE_OMIT_SCHEMA_PRAGMAS)

  121296.  {/* zName:     */ "database_list",

  121297.   /* ePragTyp:  */ PragTyp_DATABASE_LIST,

  121298.   /* ePragFlg:  */ PragFlg_NeedSchema|PragFlg_Result0,

  121299.   /* ColNames:  */ 35, 3,

  121300.   /* iArg:      */ 0 },

  121301. #endif

  121302. #if !defined(SQLITE_OMIT_PAGER_PRAGMAS) && !defined(SQLITE_OMIT_DEPRECATED)

  121303.  {/* zName:     */ "default_cache_size",

  121304.   /* ePragTyp:  */ PragTyp_DEFAULT_CACHE_SIZE,

  121305.   /* ePragFlg:  */ PragFlg_NeedSchema|PragFlg_Result0|PragFlg_SchemaReq|PragFlg_NoColumns1,

  121306.   /* ColNames:  */ 45, 1,

  121307.   /* iArg:      */ 0 },

  121308. #endif

  121309. #if !defined(SQLITE_OMIT_FLAG_PRAGMAS)

  121310. #if !defined(SQLITE_OMIT_FOREIGN_KEY) && !defined(SQLITE_OMIT_TRIGGER)

  121311.  {/* zName:     */ "defer_foreign_keys",

  121312.   /* ePragTyp:  */ PragTyp_FLAG,

  121313.   /* ePragFlg:  */ PragFlg_Result0|PragFlg_NoColumns1,

  121314.   /* ColNames:  */ 0, 0,

  121315.   /* iArg:      */ SQLITE_DeferFKs },

  121316. #endif

  121317. #endif

  121318. #if !defined(SQLITE_OMIT_FLAG_PRAGMAS)

  121319.  {/* zName:     */ "empty_result_callbacks",

  121320.   /* ePragTyp:  */ PragTyp_FLAG,

  121321.   /* ePragFlg:  */ PragFlg_Result0|PragFlg_NoColumns1,

  121322.   /* ColNames:  */ 0, 0,

  121323.   /* iArg:      */ SQLITE_NullCallback },

  121324. #endif

  121325. #if !defined(SQLITE_OMIT_UTF16)

  121326.  {/* zName:     */ "encoding",

  121327.   /* ePragTyp:  */ PragTyp_ENCODING,

  121328.   /* ePragFlg:  */ PragFlg_Result0|PragFlg_NoColumns1,

  121329.   /* ColNames:  */ 0, 0,

  121330.   /* iArg:      */ 0 },

  121331. #endif

  121332. #if !defined(SQLITE_OMIT_FOREIGN_KEY) && !defined(SQLITE_OMIT_TRIGGER)

  121333.  {/* zName:     */ "foreign_key_check",

  121334.   /* ePragTyp:  */ PragTyp_FOREIGN_KEY_CHECK,

  121335.   /* ePragFlg:  */ PragFlg_NeedSchema|PragFlg_Result0,

  121336.   /* ColNames:  */ 31, 4,

  121337.   /* iArg:      */ 0 },

  121338. #endif

  121339. #if !defined(SQLITE_OMIT_FOREIGN_KEY)

  121340.  {/* zName:     */ "foreign_key_list",

  121341.   /* ePragTyp:  */ PragTyp_FOREIGN_KEY_LIST,

  121342.   /* ePragFlg:  */ PragFlg_NeedSchema|PragFlg_Result1|PragFlg_SchemaOpt,

  121343.   /* ColNames:  */ 0, 8,

  121344.   /* iArg:      */ 0 },

  121345. #endif

  121346. #if !defined(SQLITE_OMIT_FLAG_PRAGMAS)

  121347. #if !defined(SQLITE_OMIT_FOREIGN_KEY) && !defined(SQLITE_OMIT_TRIGGER)

  121348.  {/* zName:     */ "foreign_keys",

  121349.   /* ePragTyp:  */ PragTyp_FLAG,

  121350.   /* ePragFlg:  */ PragFlg_Result0|PragFlg_NoColumns1,

  121351.   /* ColNames:  */ 0, 0,

  121352.   /* iArg:      */ SQLITE_ForeignKeys },

  121353. #endif

  121354. #endif

  121355. #if !defined(SQLITE_OMIT_SCHEMA_VERSION_PRAGMAS)

  121356.  {/* zName:     */ "freelist_count",

  121357.   /* ePragTyp:  */ PragTyp_HEADER_VALUE,

  121358.   /* ePragFlg:  */ PragFlg_ReadOnly|PragFlg_Result0,

  121359.   /* ColNames:  */ 0, 0,

  121360.   /* iArg:      */ BTREE_FREE_PAGE_COUNT },

  121361. #endif

  121362. #if !defined(SQLITE_OMIT_FLAG_PRAGMAS)

  121363.  {/* zName:     */ "full_column_names",

  121364.   /* ePragTyp:  */ PragTyp_FLAG,

  121365.   /* ePragFlg:  */ PragFlg_Result0|PragFlg_NoColumns1,

  121366.   /* ColNames:  */ 0, 0,

  121367.   /* iArg:      */ SQLITE_FullColNames },

  121368.  {/* zName:     */ "fullfsync",

  121369.   /* ePragTyp:  */ PragTyp_FLAG,

  121370.   /* ePragFlg:  */ PragFlg_Result0|PragFlg_NoColumns1,

  121371.   /* ColNames:  */ 0, 0,

  121372.   /* iArg:      */ SQLITE_FullFSync },

  121373. #endif

  121374. #if !defined(SQLITE_OMIT_SCHEMA_PRAGMAS)

  121375. #if defined(SQLITE_INTROSPECTION_PRAGMAS)

  121376.  {/* zName:     */ "function_list",

  121377.   /* ePragTyp:  */ PragTyp_FUNCTION_LIST,

  121378.   /* ePragFlg:  */ PragFlg_Result0,

  121379.   /* ColNames:  */ 41, 2,

  121380.   /* iArg:      */ 0 },

  121381. #endif

  121382. #endif

  121383. #if defined(SQLITE_HAS_CODEC)

  121384.  {/* zName:     */ "hexkey",

  121385.   /* ePragTyp:  */ PragTyp_KEY,

  121386.   /* ePragFlg:  */ 0,

  121387.   /* ColNames:  */ 0, 0,

  121388.   /* iArg:      */ 2 },

  121389.  {/* zName:     */ "hexrekey",

  121390.   /* ePragTyp:  */ PragTyp_KEY,

  121391.   /* ePragFlg:  */ 0,

  121392.   /* ColNames:  */ 0, 0,

  121393.   /* iArg:      */ 3 },

  121394. #endif

  121395. #if !defined(SQLITE_OMIT_FLAG_PRAGMAS)

  121396. #if !defined(SQLITE_OMIT_CHECK)

  121397.  {/* zName:     */ "ignore_check_constraints",

  121398.   /* ePragTyp:  */ PragTyp_FLAG,

  121399.   /* ePragFlg:  */ PragFlg_Result0|PragFlg_NoColumns1,

  121400.   /* ColNames:  */ 0, 0,

  121401.   /* iArg:      */ SQLITE_IgnoreChecks },

  121402. #endif

  121403. #endif

  121404. #if !defined(SQLITE_OMIT_AUTOVACUUM)

  121405.  {/* zName:     */ "incremental_vacuum",

  121406.   /* ePragTyp:  */ PragTyp_INCREMENTAL_VACUUM,

  121407.   /* ePragFlg:  */ PragFlg_NeedSchema|PragFlg_NoColumns,

  121408.   /* ColNames:  */ 0, 0,

  121409.   /* iArg:      */ 0 },

  121410. #endif

  121411. #if !defined(SQLITE_OMIT_SCHEMA_PRAGMAS)

  121412.  {/* zName:     */ "index_info",

  121413.   /* ePragTyp:  */ PragTyp_INDEX_INFO,

  121414.   /* ePragFlg:  */ PragFlg_NeedSchema|PragFlg_Result1|PragFlg_SchemaOpt,

  121415.   /* ColNames:  */ 15, 3,

  121416.   /* iArg:      */ 0 },

  121417.  {/* zName:     */ "index_list",

  121418.   /* ePragTyp:  */ PragTyp_INDEX_LIST,

  121419.   /* ePragFlg:  */ PragFlg_NeedSchema|PragFlg_Result1|PragFlg_SchemaOpt,

  121420.   /* ColNames:  */ 26, 5,

  121421.   /* iArg:      */ 0 },

  121422.  {/* zName:     */ "index_xinfo",

  121423.   /* ePragTyp:  */ PragTyp_INDEX_INFO,

  121424.   /* ePragFlg:  */ PragFlg_NeedSchema|PragFlg_Result1|PragFlg_SchemaOpt,

  121425.   /* ColNames:  */ 15, 6,

  121426.   /* iArg:      */ 1 },

  121427. #endif

  121428. #if !defined(SQLITE_OMIT_INTEGRITY_CHECK)

  121429.  {/* zName:     */ "integrity_check",

  121430.   /* ePragTyp:  */ PragTyp_INTEGRITY_CHECK,

  121431.   /* ePragFlg:  */ PragFlg_NeedSchema|PragFlg_Result0|PragFlg_Result1,

  121432.   /* ColNames:  */ 0, 0,

  121433.   /* iArg:      */ 0 },

  121434. #endif

  121435. #if !defined(SQLITE_OMIT_PAGER_PRAGMAS)

  121436.  {/* zName:     */ "journal_mode",

  121437.   /* ePragTyp:  */ PragTyp_JOURNAL_MODE,

  121438.   /* ePragFlg:  */ PragFlg_NeedSchema|PragFlg_Result0|PragFlg_SchemaReq,

  121439.   /* ColNames:  */ 0, 0,

  121440.   /* iArg:      */ 0 },

  121441.  {/* zName:     */ "journal_size_limit",

  121442.   /* ePragTyp:  */ PragTyp_JOURNAL_SIZE_LIMIT,

  121443.   /* ePragFlg:  */ PragFlg_Result0|PragFlg_SchemaReq,

  121444.   /* ColNames:  */ 0, 0,

  121445.   /* iArg:      */ 0 },

  121446. #endif

  121447. #if defined(SQLITE_HAS_CODEC)

  121448.  {/* zName:     */ "key",

  121449.   /* ePragTyp:  */ PragTyp_KEY,

  121450.   /* ePragFlg:  */ 0,

  121451.   /* ColNames:  */ 0, 0,

  121452.   /* iArg:      */ 0 },

  121453. #endif

  121454. #if !defined(SQLITE_OMIT_FLAG_PRAGMAS)

  121455.  {/* zName:     */ "legacy_alter_table",

  121456.   /* ePragTyp:  */ PragTyp_FLAG,

  121457.   /* ePragFlg:  */ PragFlg_Result0|PragFlg_NoColumns1,

  121458.   /* ColNames:  */ 0, 0,

  121459.   /* iArg:      */ SQLITE_LegacyAlter },

  121460.  {/* zName:     */ "legacy_file_format",

  121461.   /* ePragTyp:  */ PragTyp_FLAG,

  121462.   /* ePragFlg:  */ PragFlg_Result0|PragFlg_NoColumns1,

  121463.   /* ColNames:  */ 0, 0,

  121464.   /* iArg:      */ SQLITE_LegacyFileFmt },

  121465. #endif

  121466. #if !defined(SQLITE_OMIT_PAGER_PRAGMAS) && SQLITE_ENABLE_LOCKING_STYLE

  121467.  {/* zName:     */ "lock_proxy_file",

  121468.   /* ePragTyp:  */ PragTyp_LOCK_PROXY_FILE,

  121469.   /* ePragFlg:  */ PragFlg_NoColumns1,

  121470.   /* ColNames:  */ 0, 0,

  121471.   /* iArg:      */ 0 },

  121472. #endif

  121473. #if defined(SQLITE_DEBUG) || defined(SQLITE_TEST)

  121474.  {/* zName:     */ "lock_status",

  121475.   /* ePragTyp:  */ PragTyp_LOCK_STATUS,

  121476.   /* ePragFlg:  */ PragFlg_Result0,

  121477.   /* ColNames:  */ 43, 2,

  121478.   /* iArg:      */ 0 },

  121479. #endif

  121480. #if !defined(SQLITE_OMIT_PAGER_PRAGMAS)

  121481.  {/* zName:     */ "locking_mode",

  121482.   /* ePragTyp:  */ PragTyp_LOCKING_MODE,

  121483.   /* ePragFlg:  */ PragFlg_Result0|PragFlg_SchemaReq,

  121484.   /* ColNames:  */ 0, 0,

  121485.   /* iArg:      */ 0 },

  121486.  {/* zName:     */ "max_page_count",

  121487.   /* ePragTyp:  */ PragTyp_PAGE_COUNT,

  121488.   /* ePragFlg:  */ PragFlg_NeedSchema|PragFlg_Result0|PragFlg_SchemaReq,

  121489.   /* ColNames:  */ 0, 0,

  121490.   /* iArg:      */ 0 },

  121491.  {/* zName:     */ "mmap_size",

  121492.   /* ePragTyp:  */ PragTyp_MMAP_SIZE,

  121493.   /* ePragFlg:  */ 0,

  121494.   /* ColNames:  */ 0, 0,

  121495.   /* iArg:      */ 0 },

  121496. #endif

  121497. #if !defined(SQLITE_OMIT_SCHEMA_PRAGMAS)

  121498. #if !defined(SQLITE_OMIT_VIRTUALTABLE)

  121499. #if defined(SQLITE_INTROSPECTION_PRAGMAS)

  121500.  {/* zName:     */ "module_list",

  121501.   /* ePragTyp:  */ PragTyp_MODULE_LIST,

  121502.   /* ePragFlg:  */ PragFlg_Result0,

  121503.   /* ColNames:  */ 9, 1,

  121504.   /* iArg:      */ 0 },

  121505. #endif

  121506. #endif

  121507. #endif

  121508.  {/* zName:     */ "optimize",

  121509.   /* ePragTyp:  */ PragTyp_OPTIMIZE,

  121510.   /* ePragFlg:  */ PragFlg_Result1|PragFlg_NeedSchema,

  121511.   /* ColNames:  */ 0, 0,

  121512.   /* iArg:      */ 0 },

  121513. #if !defined(SQLITE_OMIT_PAGER_PRAGMAS)

  121514.  {/* zName:     */ "page_count",

  121515.   /* ePragTyp:  */ PragTyp_PAGE_COUNT,

  121516.   /* ePragFlg:  */ PragFlg_NeedSchema|PragFlg_Result0|PragFlg_SchemaReq,

  121517.   /* ColNames:  */ 0, 0,

  121518.   /* iArg:      */ 0 },

  121519.  {/* zName:     */ "page_size",

  121520.   /* ePragTyp:  */ PragTyp_PAGE_SIZE,

  121521.   /* ePragFlg:  */ PragFlg_Result0|PragFlg_SchemaReq|PragFlg_NoColumns1,

  121522.   /* ColNames:  */ 0, 0,

  121523.   /* iArg:      */ 0 },

  121524. #endif

  121525. #if !defined(SQLITE_OMIT_FLAG_PRAGMAS)

  121526. #if defined(SQLITE_DEBUG)

  121527.  {/* zName:     */ "parser_trace",

  121528.   /* ePragTyp:  */ PragTyp_FLAG,

  121529.   /* ePragFlg:  */ PragFlg_Result0|PragFlg_NoColumns1,

  121530.   /* ColNames:  */ 0, 0,

  121531.   /* iArg:      */ SQLITE_ParserTrace },

  121532. #endif

  121533. #endif

  121534. #if defined(SQLITE_INTROSPECTION_PRAGMAS)

  121535.  {/* zName:     */ "pragma_list",

  121536.   /* ePragTyp:  */ PragTyp_PRAGMA_LIST,

  121537.   /* ePragFlg:  */ PragFlg_Result0,

  121538.   /* ColNames:  */ 9, 1,

  121539.   /* iArg:      */ 0 },

  121540. #endif

  121541. #if !defined(SQLITE_OMIT_FLAG_PRAGMAS)

  121542.  {/* zName:     */ "query_only",

  121543.   /* ePragTyp:  */ PragTyp_FLAG,

  121544.   /* ePragFlg:  */ PragFlg_Result0|PragFlg_NoColumns1,

  121545.   /* ColNames:  */ 0, 0,

  121546.   /* iArg:      */ SQLITE_QueryOnly },

  121547. #endif

  121548. #if !defined(SQLITE_OMIT_INTEGRITY_CHECK)

  121549.  {/* zName:     */ "quick_check",

  121550.   /* ePragTyp:  */ PragTyp_INTEGRITY_CHECK,

  121551.   /* ePragFlg:  */ PragFlg_NeedSchema|PragFlg_Result0|PragFlg_Result1,

  121552.   /* ColNames:  */ 0, 0,

  121553.   /* iArg:      */ 0 },

  121554. #endif

  121555. #if !defined(SQLITE_OMIT_FLAG_PRAGMAS)

  121556.  {/* zName:     */ "read_uncommitted",

  121557.   /* ePragTyp:  */ PragTyp_FLAG,

  121558.   /* ePragFlg:  */ PragFlg_Result0|PragFlg_NoColumns1,

  121559.   /* ColNames:  */ 0, 0,

  121560.   /* iArg:      */ SQLITE_ReadUncommit },

  121561.  {/* zName:     */ "recursive_triggers",

  121562.   /* ePragTyp:  */ PragTyp_FLAG,

  121563.   /* ePragFlg:  */ PragFlg_Result0|PragFlg_NoColumns1,

  121564.   /* ColNames:  */ 0, 0,

  121565.   /* iArg:      */ SQLITE_RecTriggers },

  121566. #endif

  121567. #if defined(SQLITE_HAS_CODEC)

  121568.  {/* zName:     */ "rekey",

  121569.   /* ePragTyp:  */ PragTyp_KEY,

  121570.   /* ePragFlg:  */ 0,

  121571.   /* ColNames:  */ 0, 0,

  121572.   /* iArg:      */ 1 },

  121573. #endif

  121574. #if !defined(SQLITE_OMIT_FLAG_PRAGMAS)

  121575.  {/* zName:     */ "reverse_unordered_selects",

  121576.   /* ePragTyp:  */ PragTyp_FLAG,

  121577.   /* ePragFlg:  */ PragFlg_Result0|PragFlg_NoColumns1,

  121578.   /* ColNames:  */ 0, 0,

  121579.   /* iArg:      */ SQLITE_ReverseOrder },

  121580. #endif

  121581. #if !defined(SQLITE_OMIT_SCHEMA_VERSION_PRAGMAS)

  121582.  {/* zName:     */ "schema_version",

  121583.   /* ePragTyp:  */ PragTyp_HEADER_VALUE,

  121584.   /* ePragFlg:  */ PragFlg_NoColumns1|PragFlg_Result0,

  121585.   /* ColNames:  */ 0, 0,

  121586.   /* iArg:      */ BTREE_SCHEMA_VERSION },

  121587. #endif

  121588. #if !defined(SQLITE_OMIT_PAGER_PRAGMAS)

  121589.  {/* zName:     */ "secure_delete",

  121590.   /* ePragTyp:  */ PragTyp_SECURE_DELETE,

  121591.   /* ePragFlg:  */ PragFlg_Result0,

  121592.   /* ColNames:  */ 0, 0,

  121593.   /* iArg:      */ 0 },

  121594. #endif

  121595. #if !defined(SQLITE_OMIT_FLAG_PRAGMAS)

  121596.  {/* zName:     */ "short_column_names",

  121597.   /* ePragTyp:  */ PragTyp_FLAG,

  121598.   /* ePragFlg:  */ PragFlg_Result0|PragFlg_NoColumns1,

  121599.   /* ColNames:  */ 0, 0,

  121600.   /* iArg:      */ SQLITE_ShortColNames },

  121601. #endif

  121602.  {/* zName:     */ "shrink_memory",

  121603.   /* ePragTyp:  */ PragTyp_SHRINK_MEMORY,

  121604.   /* ePragFlg:  */ PragFlg_NoColumns,

  121605.   /* ColNames:  */ 0, 0,

  121606.   /* iArg:      */ 0 },

  121607.  {/* zName:     */ "soft_heap_limit",

  121608.   /* ePragTyp:  */ PragTyp_SOFT_HEAP_LIMIT,

  121609.   /* ePragFlg:  */ PragFlg_Result0,

  121610.   /* ColNames:  */ 0, 0,

  121611.   /* iArg:      */ 0 },

  121612. #if !defined(SQLITE_OMIT_FLAG_PRAGMAS)

  121613. #if defined(SQLITE_DEBUG)

  121614.  {/* zName:     */ "sql_trace",

  121615.   /* ePragTyp:  */ PragTyp_FLAG,

  121616.   /* ePragFlg:  */ PragFlg_Result0|PragFlg_NoColumns1,

  121617.   /* ColNames:  */ 0, 0,

  121618.   /* iArg:      */ SQLITE_SqlTrace },

  121619. #endif

  121620. #endif

  121621. #if !defined(SQLITE_OMIT_SCHEMA_PRAGMAS) && defined(SQLITE_DEBUG)

  121622.  {/* zName:     */ "stats",

  121623.   /* ePragTyp:  */ PragTyp_STATS,

  121624.   /* ePragFlg:  */ PragFlg_NeedSchema|PragFlg_Result0|PragFlg_SchemaReq,

  121625.   /* ColNames:  */ 21, 5,

  121626.   /* iArg:      */ 0 },

  121627. #endif

  121628. #if !defined(SQLITE_OMIT_PAGER_PRAGMAS)

  121629.  {/* zName:     */ "synchronous",

  121630.   /* ePragTyp:  */ PragTyp_SYNCHRONOUS,

  121631.   /* ePragFlg:  */ PragFlg_NeedSchema|PragFlg_Result0|PragFlg_SchemaReq|PragFlg_NoColumns1,

  121632.   /* ColNames:  */ 0, 0,

  121633.   /* iArg:      */ 0 },

  121634. #endif

  121635. #if !defined(SQLITE_OMIT_SCHEMA_PRAGMAS)

  121636.  {/* zName:     */ "table_info",

  121637.   /* ePragTyp:  */ PragTyp_TABLE_INFO,

  121638.   /* ePragFlg:  */ PragFlg_NeedSchema|PragFlg_Result1|PragFlg_SchemaOpt,

  121639.   /* ColNames:  */ 8, 6,

  121640.   /* iArg:      */ 0 },

  121641.  {/* zName:     */ "table_xinfo",

  121642.   /* ePragTyp:  */ PragTyp_TABLE_INFO,

  121643.   /* ePragFlg:  */ PragFlg_NeedSchema|PragFlg_Result1|PragFlg_SchemaOpt,

  121644.   /* ColNames:  */ 8, 7,

  121645.   /* iArg:      */ 1 },

  121646. #endif

  121647. #if !defined(SQLITE_OMIT_PAGER_PRAGMAS)

  121648.  {/* zName:     */ "temp_store",

  121649.   /* ePragTyp:  */ PragTyp_TEMP_STORE,

  121650.   /* ePragFlg:  */ PragFlg_Result0|PragFlg_NoColumns1,

  121651.   /* ColNames:  */ 0, 0,

  121652.   /* iArg:      */ 0 },

  121653.  {/* zName:     */ "temp_store_directory",

  121654.   /* ePragTyp:  */ PragTyp_TEMP_STORE_DIRECTORY,

  121655.   /* ePragFlg:  */ PragFlg_NoColumns1,

  121656.   /* ColNames:  */ 0, 0,

  121657.   /* iArg:      */ 0 },

  121658. #endif

  121659. #if defined(SQLITE_HAS_CODEC)

  121660.  {/* zName:     */ "textkey",

  121661.   /* ePragTyp:  */ PragTyp_KEY,

  121662.   /* ePragFlg:  */ 0,

  121663.   /* ColNames:  */ 0, 0,

  121664.   /* iArg:      */ 4 },

  121665.  {/* zName:     */ "textrekey",

  121666.   /* ePragTyp:  */ PragTyp_KEY,

  121667.   /* ePragFlg:  */ 0,

  121668.   /* ColNames:  */ 0, 0,

  121669.   /* iArg:      */ 5 },

  121670. #endif

  121671.  {/* zName:     */ "threads",

  121672.   /* ePragTyp:  */ PragTyp_THREADS,

  121673.   /* ePragFlg:  */ PragFlg_Result0,

  121674.   /* ColNames:  */ 0, 0,

  121675.   /* iArg:      */ 0 },

  121676. #if !defined(SQLITE_OMIT_SCHEMA_VERSION_PRAGMAS)

  121677.  {/* zName:     */ "user_version",

  121678.   /* ePragTyp:  */ PragTyp_HEADER_VALUE,

  121679.   /* ePragFlg:  */ PragFlg_NoColumns1|PragFlg_Result0,

  121680.   /* ColNames:  */ 0, 0,

  121681.   /* iArg:      */ BTREE_USER_VERSION },

  121682. #endif

  121683. #if !defined(SQLITE_OMIT_FLAG_PRAGMAS)

  121684. #if defined(SQLITE_DEBUG)

  121685.  {/* zName:     */ "vdbe_addoptrace",

  121686.   /* ePragTyp:  */ PragTyp_FLAG,

  121687.   /* ePragFlg:  */ PragFlg_Result0|PragFlg_NoColumns1,

  121688.   /* ColNames:  */ 0, 0,

  121689.   /* iArg:      */ SQLITE_VdbeAddopTrace },

  121690.  {/* zName:     */ "vdbe_debug",

  121691.   /* ePragTyp:  */ PragTyp_FLAG,

  121692.   /* ePragFlg:  */ PragFlg_Result0|PragFlg_NoColumns1,

  121693.   /* ColNames:  */ 0, 0,

  121694.   /* iArg:      */ SQLITE_SqlTrace|SQLITE_VdbeListing|SQLITE_VdbeTrace },

  121695.  {/* zName:     */ "vdbe_eqp",

  121696.   /* ePragTyp:  */ PragTyp_FLAG,

  121697.   /* ePragFlg:  */ PragFlg_Result0|PragFlg_NoColumns1,

  121698.   /* ColNames:  */ 0, 0,

  121699.   /* iArg:      */ SQLITE_VdbeEQP },

  121700.  {/* zName:     */ "vdbe_listing",

  121701.   /* ePragTyp:  */ PragTyp_FLAG,

  121702.   /* ePragFlg:  */ PragFlg_Result0|PragFlg_NoColumns1,

  121703.   /* ColNames:  */ 0, 0,

  121704.   /* iArg:      */ SQLITE_VdbeListing },

  121705.  {/* zName:     */ "vdbe_trace",

  121706.   /* ePragTyp:  */ PragTyp_FLAG,

  121707.   /* ePragFlg:  */ PragFlg_Result0|PragFlg_NoColumns1,

  121708.   /* ColNames:  */ 0, 0,

  121709.   /* iArg:      */ SQLITE_VdbeTrace },

  121710. #endif

  121711. #endif

  121712. #if !defined(SQLITE_OMIT_WAL)

  121713.  {/* zName:     */ "wal_autocheckpoint",

  121714.   /* ePragTyp:  */ PragTyp_WAL_AUTOCHECKPOINT,

  121715.   /* ePragFlg:  */ 0,

  121716.   /* ColNames:  */ 0, 0,

  121717.   /* iArg:      */ 0 },

  121718.  {/* zName:     */ "wal_checkpoint",

  121719.   /* ePragTyp:  */ PragTyp_WAL_CHECKPOINT,

  121720.   /* ePragFlg:  */ PragFlg_NeedSchema,

  121721.   /* ColNames:  */ 38, 3,

  121722.   /* iArg:      */ 0 },

  121723. #endif

  121724. #if !defined(SQLITE_OMIT_FLAG_PRAGMAS)

  121725.  {/* zName:     */ "writable_schema",

  121726.   /* ePragTyp:  */ PragTyp_FLAG,

  121727.   /* ePragFlg:  */ PragFlg_Result0|PragFlg_NoColumns1,

  121728.   /* ColNames:  */ 0, 0,

  121729.   /* iArg:      */ SQLITE_WriteSchema|SQLITE_NoSchemaError },

  121730. #endif

  121731. };

  121732. /* Number of pragmas: 62 on by default, 81 total. */

  121733. 

  121734. /************** End of pragma.h **********************************************/

  121735. /************** Continuing where we left off in pragma.c *********************/

  121736. 

  121737. /*

  121738. ** Interpret the given string as a safety level.  Return 0 for OFF,

  121739. ** 1 for ON or NORMAL, 2 for FULL, and 3 for EXTRA.  Return 1 for an empty or 

  121740. ** unrecognized string argument.  The FULL and EXTRA option is disallowed

  121741. ** if the omitFull parameter it 1.

  121742. **

  121743. ** Note that the values returned are one less that the values that

  121744. ** should be passed into sqlite3BtreeSetSafetyLevel().  The is done

  121745. ** to support legacy SQL code.  The safety level used to be boolean

  121746. ** and older scripts may have used numbers 0 for OFF and 1 for ON.

  121747. */

  121748. static u8 getSafetyLevel(const char *z, int omitFull, u8 dflt){

  121749.                              /* 123456789 123456789 123 */

  121750.   static const char zText[] = "onoffalseyestruextrafull";

  121751.   static const u8 iOffset[] = {0, 1, 2,  4,    9,  12,  15,   20};

  121752.   static const u8 iLength[] = {2, 2, 3,  5,    3,   4,   5,    4};

  121753.   static const u8 iValue[] =  {1, 0, 0,  0,    1,   1,   3,    2};

  121754.                             /* on no off false yes true extra full */

  121755.   int i, n;

  121756.   if( sqlite3Isdigit(*z) ){

  121757.     return (u8)sqlite3Atoi(z);

  121758.   }

  121759.   n = sqlite3Strlen30(z);

  121760.   for(i=0; i<ArraySize(iLength); i++){

  121761.     if( iLength[i]==n && sqlite3StrNICmp(&zText[iOffset[i]],z,n)==0

  121762.      && (!omitFull || iValue[i]<=1)

  121763.     ){

  121764.       return iValue[i];

  121765.     }

  121766.   }

  121767.   return dflt;

  121768. }

  121769. 

  121770. /*

  121771. ** Interpret the given string as a boolean value.

  121772. */

  121773. SQLITE_PRIVATE u8 sqlite3GetBoolean(const char *z, u8 dflt){

  121774.   return getSafetyLevel(z,1,dflt)!=0;

  121775. }

  121776. 

  121777. /* The sqlite3GetBoolean() function is used by other modules but the

  121778. ** remainder of this file is specific to PRAGMA processing.  So omit

  121779. ** the rest of the file if PRAGMAs are omitted from the build.

  121780. */

  121781. #if !defined(SQLITE_OMIT_PRAGMA)

  121782. 

  121783. /*

  121784. ** Interpret the given string as a locking mode value.

  121785. */

  121786. static int getLockingMode(const char *z){

  121787.   if( z ){

  121788.     if( 0==sqlite3StrICmp(z, "exclusive") ) return PAGER_LOCKINGMODE_EXCLUSIVE;

  121789.     if( 0==sqlite3StrICmp(z, "normal") ) return PAGER_LOCKINGMODE_NORMAL;

  121790.   }

  121791.   return PAGER_LOCKINGMODE_QUERY;

  121792. }

  121793. 

  121794. #ifndef SQLITE_OMIT_AUTOVACUUM

  121795. /*

  121796. ** Interpret the given string as an auto-vacuum mode value.

  121797. **

  121798. ** The following strings, "none", "full" and "incremental" are 

  121799. ** acceptable, as are their numeric equivalents: 0, 1 and 2 respectively.

  121800. */

  121801. static int getAutoVacuum(const char *z){

  121802.   int i;

  121803.   if( 0==sqlite3StrICmp(z, "none") ) return BTREE_AUTOVACUUM_NONE;

  121804.   if( 0==sqlite3StrICmp(z, "full") ) return BTREE_AUTOVACUUM_FULL;

  121805.   if( 0==sqlite3StrICmp(z, "incremental") ) return BTREE_AUTOVACUUM_INCR;

  121806.   i = sqlite3Atoi(z);

  121807.   return (u8)((i>=0&&i<=2)?i:0);

  121808. }

  121809. #endif /* ifndef SQLITE_OMIT_AUTOVACUUM */

  121810. 

  121811. #ifndef SQLITE_OMIT_PAGER_PRAGMAS

  121812. /*

  121813. ** Interpret the given string as a temp db location. Return 1 for file

  121814. ** backed temporary databases, 2 for the Red-Black tree in memory database

  121815. ** and 0 to use the compile-time default.

  121816. */

  121817. static int getTempStore(const char *z){

  121818.   if( z[0]>='0' && z[0]<='2' ){

  121819.     return z[0] - '0';

  121820.   }else if( sqlite3StrICmp(z, "file")==0 ){

  121821.     return 1;

  121822.   }else if( sqlite3StrICmp(z, "memory")==0 ){

  121823.     return 2;

  121824.   }else{

  121825.     return 0;

  121826.   }

  121827. }

  121828. #endif /* SQLITE_PAGER_PRAGMAS */

  121829. 

  121830. #ifndef SQLITE_OMIT_PAGER_PRAGMAS

  121831. /*

  121832. ** Invalidate temp storage, either when the temp storage is changed

  121833. ** from default, or when 'file' and the temp_store_directory has changed

  121834. */

  121835. static int invalidateTempStorage(Parse *pParse){

  121836.   sqlite3 *db = pParse->db;

  121837.   if( db->aDb[1].pBt!=0 ){

  121838.     if( !db->autoCommit || sqlite3BtreeIsInReadTrans(db->aDb[1].pBt) ){

  121839.       sqlite3ErrorMsg(pParse, "temporary storage cannot be changed "

  121840.         "from within a transaction");

  121841.       return SQLITE_ERROR;

  121842.     }

  121843.     sqlite3BtreeClose(db->aDb[1].pBt);

  121844.     db->aDb[1].pBt = 0;

  121845.     sqlite3ResetAllSchemasOfConnection(db);

  121846.   }

  121847.   return SQLITE_OK;

  121848. }

  121849. #endif /* SQLITE_PAGER_PRAGMAS */

  121850. 

  121851. #ifndef SQLITE_OMIT_PAGER_PRAGMAS

  121852. /*

  121853. ** If the TEMP database is open, close it and mark the database schema

  121854. ** as needing reloading.  This must be done when using the SQLITE_TEMP_STORE

  121855. ** or DEFAULT_TEMP_STORE pragmas.

  121856. */

  121857. static int changeTempStorage(Parse *pParse, const char *zStorageType){

  121858.   int ts = getTempStore(zStorageType);

  121859.   sqlite3 *db = pParse->db;

  121860.   if( db->temp_store==ts ) return SQLITE_OK;

  121861.   if( invalidateTempStorage( pParse ) != SQLITE_OK ){

  121862.     return SQLITE_ERROR;

  121863.   }

  121864.   db->temp_store = (u8)ts;

  121865.   return SQLITE_OK;

  121866. }

  121867. #endif /* SQLITE_PAGER_PRAGMAS */

  121868. 

  121869. /*

  121870. ** Set result column names for a pragma.

  121871. */

  121872. static void setPragmaResultColumnNames(

  121873.   Vdbe *v,                     /* The query under construction */

  121874.   const PragmaName *pPragma    /* The pragma */

  121875. ){

  121876.   u8 n = pPragma->nPragCName;

  121877.   sqlite3VdbeSetNumCols(v, n==0 ? 1 : n);

  121878.   if( n==0 ){

  121879.     sqlite3VdbeSetColName(v, 0, COLNAME_NAME, pPragma->zName, SQLITE_STATIC);

  121880.   }else{

  121881.     int i, j;

  121882.     for(i=0, j=pPragma->iPragCName; i<n; i++, j++){

  121883.       sqlite3VdbeSetColName(v, i, COLNAME_NAME, pragCName[j], SQLITE_STATIC);

  121884.     }

  121885.   }

  121886. }

  121887. 

  121888. /*

  121889. ** Generate code to return a single integer value.

  121890. */

  121891. static void returnSingleInt(Vdbe *v, i64 value){

  121892.   sqlite3VdbeAddOp4Dup8(v, OP_Int64, 0, 1, 0, (const u8*)&value, P4_INT64);

  121893.   sqlite3VdbeAddOp2(v, OP_ResultRow, 1, 1);

  121894. }

  121895. 

  121896. /*

  121897. ** Generate code to return a single text value.

  121898. */

  121899. static void returnSingleText(

  121900.   Vdbe *v,                /* Prepared statement under construction */

  121901.   const char *zValue      /* Value to be returned */

  121902. ){

  121903.   if( zValue ){

  121904.     sqlite3VdbeLoadString(v, 1, (const char*)zValue);

  121905.     sqlite3VdbeAddOp2(v, OP_ResultRow, 1, 1);

  121906.   }

  121907. }

  121908. 

  121909. 

  121910. /*

  121911. ** Set the safety_level and pager flags for pager iDb.  Or if iDb<0

  121912. ** set these values for all pagers.

  121913. */

  121914. #ifndef SQLITE_OMIT_PAGER_PRAGMAS

  121915. static void setAllPagerFlags(sqlite3 *db){

  121916.   if( db->autoCommit ){

  121917.     Db *pDb = db->aDb;

  121918.     int n = db->nDb;

  121919.     assert( SQLITE_FullFSync==PAGER_FULLFSYNC );

  121920.     assert( SQLITE_CkptFullFSync==PAGER_CKPT_FULLFSYNC );

  121921.     assert( SQLITE_CacheSpill==PAGER_CACHESPILL );

  121922.     assert( (PAGER_FULLFSYNC | PAGER_CKPT_FULLFSYNC | PAGER_CACHESPILL)

  121923.              ==  PAGER_FLAGS_MASK );

  121924.     assert( (pDb->safety_level & PAGER_SYNCHRONOUS_MASK)==pDb->safety_level );

  121925.     while( (n--) > 0 ){

  121926.       if( pDb->pBt ){

  121927.         sqlite3BtreeSetPagerFlags(pDb->pBt,

  121928.                  pDb->safety_level | (db->flags & PAGER_FLAGS_MASK) );

  121929.       }

  121930.       pDb++;

  121931.     }

  121932.   }

  121933. }

  121934. #else

  121935. # define setAllPagerFlags(X)  /* no-op */

  121936. #endif

  121937. 

  121938. 

  121939. /*

  121940. ** Return a human-readable name for a constraint resolution action.

  121941. */

  121942. #ifndef SQLITE_OMIT_FOREIGN_KEY

  121943. static const char *actionName(u8 action){

  121944.   const char *zName;

  121945.   switch( action ){

  121946.     case OE_SetNull:  zName = "SET NULL";        break;

  121947.     case OE_SetDflt:  zName = "SET DEFAULT";     break;

  121948.     case OE_Cascade:  zName = "CASCADE";         break;

  121949.     case OE_Restrict: zName = "RESTRICT";        break;

  121950.     default:          zName = "NO ACTION";  

  121951.                       assert( action==OE_None ); break;

  121952.   }

  121953.   return zName;

  121954. }

  121955. #endif

  121956. 

  121957. 

  121958. /*

  121959. ** Parameter eMode must be one of the PAGER_JOURNALMODE_XXX constants

  121960. ** defined in pager.h. This function returns the associated lowercase

  121961. ** journal-mode name.

  121962. */

  121963. SQLITE_PRIVATE const char *sqlite3JournalModename(int eMode){

  121964.   static char * const azModeName[] = {

  121965.     "delete", "persist", "off", "truncate", "memory"

  121966. #ifndef SQLITE_OMIT_WAL

  121967.      , "wal"

  121968. #endif

  121969.   };

  121970.   assert( PAGER_JOURNALMODE_DELETE==0 );

  121971.   assert( PAGER_JOURNALMODE_PERSIST==1 );

  121972.   assert( PAGER_JOURNALMODE_OFF==2 );

  121973.   assert( PAGER_JOURNALMODE_TRUNCATE==3 );

  121974.   assert( PAGER_JOURNALMODE_MEMORY==4 );

  121975.   assert( PAGER_JOURNALMODE_WAL==5 );

  121976.   assert( eMode>=0 && eMode<=ArraySize(azModeName) );

  121977. 

  121978.   if( eMode==ArraySize(azModeName) ) return 0;

  121979.   return azModeName[eMode];

  121980. }

  121981. 

  121982. /*

  121983. ** Locate a pragma in the aPragmaName[] array.

  121984. */

  121985. static const PragmaName *pragmaLocate(const char *zName){

  121986.   int upr, lwr, mid = 0, rc;

  121987.   lwr = 0;

  121988.   upr = ArraySize(aPragmaName)-1;

  121989.   while( lwr<=upr ){

  121990.     mid = (lwr+upr)/2;

  121991.     rc = sqlite3_stricmp(zName, aPragmaName[mid].zName);

  121992.     if( rc==0 ) break;

  121993.     if( rc<0 ){

  121994.       upr = mid - 1;

  121995.     }else{

  121996.       lwr = mid + 1;

  121997.     }

  121998.   }

  121999.   return lwr>upr ? 0 : &aPragmaName[mid];

  122000. }

  122001. 

  122002. /*

  122003. ** Helper subroutine for PRAGMA integrity_check:

  122004. **

  122005. ** Generate code to output a single-column result row with a value of the

  122006. ** string held in register 3.  Decrement the result count in register 1

  122007. ** and halt if the maximum number of result rows have been issued.

  122008. */

  122009. static int integrityCheckResultRow(Vdbe *v){

  122010.   int addr;

  122011.   sqlite3VdbeAddOp2(v, OP_ResultRow, 3, 1);

  122012.   addr = sqlite3VdbeAddOp3(v, OP_IfPos, 1, sqlite3VdbeCurrentAddr(v)+2, 1);

  122013.   VdbeCoverage(v);

  122014.   sqlite3VdbeAddOp0(v, OP_Halt);

  122015.   return addr;

  122016. }

  122017. 

  122018. /*

  122019. ** Process a pragma statement.  

  122020. **

  122021. ** Pragmas are of this form:

  122022. **

  122023. **      PRAGMA [schema.]id [= value]

  122024. **

  122025. ** The identifier might also be a string.  The value is a string, and

  122026. ** identifier, or a number.  If minusFlag is true, then the value is

  122027. ** a number that was preceded by a minus sign.

  122028. **

  122029. ** If the left side is "database.id" then pId1 is the database name

  122030. ** and pId2 is the id.  If the left side is just "id" then pId1 is the

  122031. ** id and pId2 is any empty string.

  122032. */

  122033. SQLITE_PRIVATE void sqlite3Pragma(

  122034.   Parse *pParse, 

  122035.   Token *pId1,        /* First part of [schema.]id field */

  122036.   Token *pId2,        /* Second part of [schema.]id field, or NULL */

  122037.   Token *pValue,      /* Token for <value>, or NULL */

  122038.   int minusFlag       /* True if a '-' sign preceded <value> */

  122039. ){

  122040.   char *zLeft = 0;       /* Nul-terminated UTF-8 string <id> */

  122041.   char *zRight = 0;      /* Nul-terminated UTF-8 string <value>, or NULL */

  122042.   const char *zDb = 0;   /* The database name */

  122043.   Token *pId;            /* Pointer to <id> token */

  122044.   char *aFcntl[4];       /* Argument to SQLITE_FCNTL_PRAGMA */

  122045.   int iDb;               /* Database index for <database> */

  122046.   int rc;                      /* return value form SQLITE_FCNTL_PRAGMA */

  122047.   sqlite3 *db = pParse->db;    /* The database connection */

  122048.   Db *pDb;                     /* The specific database being pragmaed */

  122049.   Vdbe *v = sqlite3GetVdbe(pParse);  /* Prepared statement */

  122050.   const PragmaName *pPragma;   /* The pragma */

  122051. 

  122052.   if( v==0 ) return;

  122053.   sqlite3VdbeRunOnlyOnce(v);

  122054.   pParse->nMem = 2;

  122055. 

  122056.   /* Interpret the [schema.] part of the pragma statement. iDb is the

  122057.   ** index of the database this pragma is being applied to in db.aDb[]. */

  122058.   iDb = sqlite3TwoPartName(pParse, pId1, pId2, &pId);

  122059.   if( iDb<0 ) return;

  122060.   pDb = &db->aDb[iDb];

  122061. 

  122062.   /* If the temp database has been explicitly named as part of the 

  122063.   ** pragma, make sure it is open. 

  122064.   */

  122065.   if( iDb==1 && sqlite3OpenTempDatabase(pParse) ){

  122066.     return;

  122067.   }

  122068. 

  122069.   zLeft = sqlite3NameFromToken(db, pId);

  122070.   if( !zLeft ) return;

  122071.   if( minusFlag ){

  122072.     zRight = sqlite3MPrintf(db, "-%T", pValue);

  122073.   }else{

  122074.     zRight = sqlite3NameFromToken(db, pValue);

  122075.   }

  122076. 

  122077.   assert( pId2 );

  122078.   zDb = pId2->n>0 ? pDb->zDbSName : 0;

  122079.   if( sqlite3AuthCheck(pParse, SQLITE_PRAGMA, zLeft, zRight, zDb) ){

  122080.     goto pragma_out;

  122081.   }

  122082. 

  122083.   /* Send an SQLITE_FCNTL_PRAGMA file-control to the underlying VFS

  122084.   ** connection.  If it returns SQLITE_OK, then assume that the VFS

  122085.   ** handled the pragma and generate a no-op prepared statement.

  122086.   **

  122087.   ** IMPLEMENTATION-OF: R-12238-55120 Whenever a PRAGMA statement is parsed,

  122088.   ** an SQLITE_FCNTL_PRAGMA file control is sent to the open sqlite3_file

  122089.   ** object corresponding to the database file to which the pragma

  122090.   ** statement refers.

  122091.   **

  122092.   ** IMPLEMENTATION-OF: R-29875-31678 The argument to the SQLITE_FCNTL_PRAGMA

  122093.   ** file control is an array of pointers to strings (char**) in which the

  122094.   ** second element of the array is the name of the pragma and the third

  122095.   ** element is the argument to the pragma or NULL if the pragma has no

  122096.   ** argument.

  122097.   */

  122098.   aFcntl[0] = 0;

  122099.   aFcntl[1] = zLeft;

  122100.   aFcntl[2] = zRight;

  122101.   aFcntl[3] = 0;

  122102.   db->busyHandler.nBusy = 0;

  122103.   rc = sqlite3_file_control(db, zDb, SQLITE_FCNTL_PRAGMA, (void*)aFcntl);

  122104.   if( rc==SQLITE_OK ){

  122105.     sqlite3VdbeSetNumCols(v, 1);

  122106.     sqlite3VdbeSetColName(v, 0, COLNAME_NAME, aFcntl[0], SQLITE_TRANSIENT);

  122107.     returnSingleText(v, aFcntl[0]);

  122108.     sqlite3_free(aFcntl[0]);

  122109.     goto pragma_out;

  122110.   }

  122111.   if( rc!=SQLITE_NOTFOUND ){

  122112.     if( aFcntl[0] ){

  122113.       sqlite3ErrorMsg(pParse, "%s", aFcntl[0]);

  122114.       sqlite3_free(aFcntl[0]);

  122115.     }

  122116.     pParse->nErr++;

  122117.     pParse->rc = rc;

  122118.     goto pragma_out;

  122119.   }

  122120. 

  122121.   /* Locate the pragma in the lookup table */

  122122.   pPragma = pragmaLocate(zLeft);

  122123.   if( pPragma==0 ) goto pragma_out;

  122124. 

  122125.   /* Make sure the database schema is loaded if the pragma requires that */

  122126.   if( (pPragma->mPragFlg & PragFlg_NeedSchema)!=0 ){

  122127.     if( sqlite3ReadSchema(pParse) ) goto pragma_out;

  122128.   }

  122129. 

  122130.   /* Register the result column names for pragmas that return results */

  122131.   if( (pPragma->mPragFlg & PragFlg_NoColumns)==0 

  122132.    && ((pPragma->mPragFlg & PragFlg_NoColumns1)==0 || zRight==0)

  122133.   ){

  122134.     setPragmaResultColumnNames(v, pPragma);

  122135.   }

  122136. 

  122137.   /* Jump to the appropriate pragma handler */

  122138.   switch( pPragma->ePragTyp ){

  122139.   

  122140. #if !defined(SQLITE_OMIT_PAGER_PRAGMAS) && !defined(SQLITE_OMIT_DEPRECATED)

  122141.   /*

  122142.   **  PRAGMA [schema.]default_cache_size

  122143.   **  PRAGMA [schema.]default_cache_size=N

  122144.   **

  122145.   ** The first form reports the current persistent setting for the

  122146.   ** page cache size.  The value returned is the maximum number of

  122147.   ** pages in the page cache.  The second form sets both the current

  122148.   ** page cache size value and the persistent page cache size value

  122149.   ** stored in the database file.

  122150.   **

  122151.   ** Older versions of SQLite would set the default cache size to a

  122152.   ** negative number to indicate synchronous=OFF.  These days, synchronous

  122153.   ** is always on by default regardless of the sign of the default cache

  122154.   ** size.  But continue to take the absolute value of the default cache

  122155.   ** size of historical compatibility.

  122156.   */

  122157.   case PragTyp_DEFAULT_CACHE_SIZE: {

  122158.     static const int iLn = VDBE_OFFSET_LINENO(2);

  122159.     static const VdbeOpList getCacheSize[] = {

  122160.       { OP_Transaction, 0, 0,        0},                         /* 0 */

  122161.       { OP_ReadCookie,  0, 1,        BTREE_DEFAULT_CACHE_SIZE},  /* 1 */

  122162.       { OP_IfPos,       1, 8,        0},

  122163.       { OP_Integer,     0, 2,        0},

  122164.       { OP_Subtract,    1, 2,        1},

  122165.       { OP_IfPos,       1, 8,        0},

  122166.       { OP_Integer,     0, 1,        0},                         /* 6 */

  122167.       { OP_Noop,        0, 0,        0},

  122168.       { OP_ResultRow,   1, 1,        0},

  122169.     };

  122170.     VdbeOp *aOp;

  122171.     sqlite3VdbeUsesBtree(v, iDb);

  122172.     if( !zRight ){

  122173.       pParse->nMem += 2;

  122174.       sqlite3VdbeVerifyNoMallocRequired(v, ArraySize(getCacheSize));

  122175.       aOp = sqlite3VdbeAddOpList(v, ArraySize(getCacheSize), getCacheSize, iLn);

  122176.       if( ONLY_IF_REALLOC_STRESS(aOp==0) ) break;

  122177.       aOp[0].p1 = iDb;

  122178.       aOp[1].p1 = iDb;

  122179.       aOp[6].p1 = SQLITE_DEFAULT_CACHE_SIZE;

  122180.     }else{

  122181.       int size = sqlite3AbsInt32(sqlite3Atoi(zRight));

  122182.       sqlite3BeginWriteOperation(pParse, 0, iDb);

  122183.       sqlite3VdbeAddOp3(v, OP_SetCookie, iDb, BTREE_DEFAULT_CACHE_SIZE, size);

  122184.       assert( sqlite3SchemaMutexHeld(db, iDb, 0) );

  122185.       pDb->pSchema->cache_size = size;

  122186.       sqlite3BtreeSetCacheSize(pDb->pBt, pDb->pSchema->cache_size);

  122187.     }

  122188.     break;

  122189.   }

  122190. #endif /* !SQLITE_OMIT_PAGER_PRAGMAS && !SQLITE_OMIT_DEPRECATED */

  122191. 

  122192. #if !defined(SQLITE_OMIT_PAGER_PRAGMAS)

  122193.   /*

  122194.   **  PRAGMA [schema.]page_size

  122195.   **  PRAGMA [schema.]page_size=N

  122196.   **

  122197.   ** The first form reports the current setting for the

  122198.   ** database page size in bytes.  The second form sets the

  122199.   ** database page size value.  The value can only be set if

  122200.   ** the database has not yet been created.

  122201.   */

  122202.   case PragTyp_PAGE_SIZE: {

  122203.     Btree *pBt = pDb->pBt;

  122204.     assert( pBt!=0 );

  122205.     if( !zRight ){

  122206.       int size = ALWAYS(pBt) ? sqlite3BtreeGetPageSize(pBt) : 0;

  122207.       returnSingleInt(v, size);

  122208.     }else{

  122209.       /* Malloc may fail when setting the page-size, as there is an internal

  122210.       ** buffer that the pager module resizes using sqlite3_realloc().

  122211.       */

  122212.       db->nextPagesize = sqlite3Atoi(zRight);

  122213.       if( SQLITE_NOMEM==sqlite3BtreeSetPageSize(pBt, db->nextPagesize,-1,0) ){

  122214.         sqlite3OomFault(db);

  122215.       }

  122216.     }

  122217.     break;

  122218.   }

  122219. 

  122220.   /*

  122221.   **  PRAGMA [schema.]secure_delete

  122222.   **  PRAGMA [schema.]secure_delete=ON/OFF/FAST

  122223.   **

  122224.   ** The first form reports the current setting for the

  122225.   ** secure_delete flag.  The second form changes the secure_delete

  122226.   ** flag setting and reports the new value.

  122227.   */

  122228.   case PragTyp_SECURE_DELETE: {

  122229.     Btree *pBt = pDb->pBt;

  122230.     int b = -1;

  122231.     assert( pBt!=0 );

  122232.     if( zRight ){

  122233.       if( sqlite3_stricmp(zRight, "fast")==0 ){

  122234.         b = 2;

  122235.       }else{

  122236.         b = sqlite3GetBoolean(zRight, 0);

  122237.       }

  122238.     }

  122239.     if( pId2->n==0 && b>=0 ){

  122240.       int ii;

  122241.       for(ii=0; ii<db->nDb; ii++){

  122242.         sqlite3BtreeSecureDelete(db->aDb[ii].pBt, b);

  122243.       }

  122244.     }

  122245.     b = sqlite3BtreeSecureDelete(pBt, b);

  122246.     returnSingleInt(v, b);

  122247.     break;

  122248.   }

  122249. 

  122250.   /*

  122251.   **  PRAGMA [schema.]max_page_count

  122252.   **  PRAGMA [schema.]max_page_count=N

  122253.   **

  122254.   ** The first form reports the current setting for the

  122255.   ** maximum number of pages in the database file.  The 

  122256.   ** second form attempts to change this setting.  Both

  122257.   ** forms return the current setting.

  122258.   **

  122259.   ** The absolute value of N is used.  This is undocumented and might

  122260.   ** change.  The only purpose is to provide an easy way to test

  122261.   ** the sqlite3AbsInt32() function.

  122262.   **

  122263.   **  PRAGMA [schema.]page_count

  122264.   **

  122265.   ** Return the number of pages in the specified database.

  122266.   */

  122267.   case PragTyp_PAGE_COUNT: {

  122268.     int iReg;

  122269.     sqlite3CodeVerifySchema(pParse, iDb);

  122270.     iReg = ++pParse->nMem;

  122271.     if( sqlite3Tolower(zLeft[0])=='p' ){

  122272.       sqlite3VdbeAddOp2(v, OP_Pagecount, iDb, iReg);

  122273.     }else{

  122274.       sqlite3VdbeAddOp3(v, OP_MaxPgcnt, iDb, iReg, 

  122275.                         sqlite3AbsInt32(sqlite3Atoi(zRight)));

  122276.     }

  122277.     sqlite3VdbeAddOp2(v, OP_ResultRow, iReg, 1);

  122278.     break;

  122279.   }

  122280. 

  122281.   /*

  122282.   **  PRAGMA [schema.]locking_mode

  122283.   **  PRAGMA [schema.]locking_mode = (normal|exclusive)

  122284.   */

  122285.   case PragTyp_LOCKING_MODE: {

  122286.     const char *zRet = "normal";

  122287.     int eMode = getLockingMode(zRight);

  122288. 

  122289.     if( pId2->n==0 && eMode==PAGER_LOCKINGMODE_QUERY ){

  122290.       /* Simple "PRAGMA locking_mode;" statement. This is a query for

  122291.       ** the current default locking mode (which may be different to

  122292.       ** the locking-mode of the main database).

  122293.       */

  122294.       eMode = db->dfltLockMode;

  122295.     }else{

  122296.       Pager *pPager;

  122297.       if( pId2->n==0 ){

  122298.         /* This indicates that no database name was specified as part

  122299.         ** of the PRAGMA command. In this case the locking-mode must be

  122300.         ** set on all attached databases, as well as the main db file.

  122301.         **

  122302.         ** Also, the sqlite3.dfltLockMode variable is set so that

  122303.         ** any subsequently attached databases also use the specified

  122304.         ** locking mode.

  122305.         */

  122306.         int ii;

  122307.         assert(pDb==&db->aDb[0]);

  122308.         for(ii=2; ii<db->nDb; ii++){

  122309.           pPager = sqlite3BtreePager(db->aDb[ii].pBt);

  122310.           sqlite3PagerLockingMode(pPager, eMode);

  122311.         }

  122312.         db->dfltLockMode = (u8)eMode;

  122313.       }

  122314.       pPager = sqlite3BtreePager(pDb->pBt);

  122315.       eMode = sqlite3PagerLockingMode(pPager, eMode);

  122316.     }

  122317. 

  122318.     assert( eMode==PAGER_LOCKINGMODE_NORMAL

  122319.             || eMode==PAGER_LOCKINGMODE_EXCLUSIVE );

  122320.     if( eMode==PAGER_LOCKINGMODE_EXCLUSIVE ){

  122321.       zRet = "exclusive";

  122322.     }

  122323.     returnSingleText(v, zRet);

  122324.     break;

  122325.   }

  122326. 

  122327.   /*

  122328.   **  PRAGMA [schema.]journal_mode

  122329.   **  PRAGMA [schema.]journal_mode =

  122330.   **                      (delete|persist|off|truncate|memory|wal|off)

  122331.   */

  122332.   case PragTyp_JOURNAL_MODE: {

  122333.     int eMode;        /* One of the PAGER_JOURNALMODE_XXX symbols */

  122334.     int ii;           /* Loop counter */

  122335. 

  122336.     if( zRight==0 ){

  122337.       /* If there is no "=MODE" part of the pragma, do a query for the

  122338.       ** current mode */

  122339.       eMode = PAGER_JOURNALMODE_QUERY;

  122340.     }else{

  122341.       const char *zMode;

  122342.       int n = sqlite3Strlen30(zRight);

  122343.       for(eMode=0; (zMode = sqlite3JournalModename(eMode))!=0; eMode++){

  122344.         if( sqlite3StrNICmp(zRight, zMode, n)==0 ) break;

  122345.       }

  122346.       if( !zMode ){

  122347.         /* If the "=MODE" part does not match any known journal mode,

  122348.         ** then do a query */

  122349.         eMode = PAGER_JOURNALMODE_QUERY;

  122350.       }

  122351.       if( eMode==PAGER_JOURNALMODE_OFF && (db->flags & SQLITE_Defensive)!=0 ){

  122352.         /* Do not allow journal-mode "OFF" in defensive since the database

  122353.         ** can become corrupted using ordinary SQL when the journal is off */

  122354.         eMode = PAGER_JOURNALMODE_QUERY;

  122355.       }

  122356.     }

  122357.     if( eMode==PAGER_JOURNALMODE_QUERY && pId2->n==0 ){

  122358.       /* Convert "PRAGMA journal_mode" into "PRAGMA main.journal_mode" */

  122359.       iDb = 0;

  122360.       pId2->n = 1;

  122361.     }

  122362.     for(ii=db->nDb-1; ii>=0; ii--){

  122363.       if( db->aDb[ii].pBt && (ii==iDb || pId2->n==0) ){

  122364.         sqlite3VdbeUsesBtree(v, ii);

  122365.         sqlite3VdbeAddOp3(v, OP_JournalMode, ii, 1, eMode);

  122366.       }

  122367.     }

  122368.     sqlite3VdbeAddOp2(v, OP_ResultRow, 1, 1);

  122369.     break;

  122370.   }

  122371. 

  122372.   /*

  122373.   **  PRAGMA [schema.]journal_size_limit

  122374.   **  PRAGMA [schema.]journal_size_limit=N

  122375.   **

  122376.   ** Get or set the size limit on rollback journal files.

  122377.   */

  122378.   case PragTyp_JOURNAL_SIZE_LIMIT: {

  122379.     Pager *pPager = sqlite3BtreePager(pDb->pBt);

  122380.     i64 iLimit = -2;

  122381.     if( zRight ){

  122382.       sqlite3DecOrHexToI64(zRight, &iLimit);

  122383.       if( iLimit<-1 ) iLimit = -1;

  122384.     }

  122385.     iLimit = sqlite3PagerJournalSizeLimit(pPager, iLimit);

  122386.     returnSingleInt(v, iLimit);

  122387.     break;

  122388.   }

  122389. 

  122390. #endif /* SQLITE_OMIT_PAGER_PRAGMAS */

  122391. 

  122392.   /*

  122393.   **  PRAGMA [schema.]auto_vacuum

  122394.   **  PRAGMA [schema.]auto_vacuum=N

  122395.   **

  122396.   ** Get or set the value of the database 'auto-vacuum' parameter.

  122397.   ** The value is one of:  0 NONE 1 FULL 2 INCREMENTAL

  122398.   */

  122399. #ifndef SQLITE_OMIT_AUTOVACUUM

  122400.   case PragTyp_AUTO_VACUUM: {

  122401.     Btree *pBt = pDb->pBt;

  122402.     assert( pBt!=0 );

  122403.     if( !zRight ){

  122404.       returnSingleInt(v, sqlite3BtreeGetAutoVacuum(pBt));

  122405.     }else{

  122406.       int eAuto = getAutoVacuum(zRight);

  122407.       assert( eAuto>=0 && eAuto<=2 );

  122408.       db->nextAutovac = (u8)eAuto;

  122409.       /* Call SetAutoVacuum() to set initialize the internal auto and

  122410.       ** incr-vacuum flags. This is required in case this connection

  122411.       ** creates the database file. It is important that it is created

  122412.       ** as an auto-vacuum capable db.

  122413.       */

  122414.       rc = sqlite3BtreeSetAutoVacuum(pBt, eAuto);

  122415.       if( rc==SQLITE_OK && (eAuto==1 || eAuto==2) ){

  122416.         /* When setting the auto_vacuum mode to either "full" or 

  122417.         ** "incremental", write the value of meta[6] in the database

  122418.         ** file. Before writing to meta[6], check that meta[3] indicates

  122419.         ** that this really is an auto-vacuum capable database.

  122420.         */

  122421.         static const int iLn = VDBE_OFFSET_LINENO(2);

  122422.         static const VdbeOpList setMeta6[] = {

  122423.           { OP_Transaction,    0,         1,                 0},    /* 0 */

  122424.           { OP_ReadCookie,     0,         1,         BTREE_LARGEST_ROOT_PAGE},

  122425.           { OP_If,             1,         0,                 0},    /* 2 */

  122426.           { OP_Halt,           SQLITE_OK, OE_Abort,          0},    /* 3 */

  122427.           { OP_SetCookie,      0,         BTREE_INCR_VACUUM, 0},    /* 4 */

  122428.         };

  122429.         VdbeOp *aOp;

  122430.         int iAddr = sqlite3VdbeCurrentAddr(v);

  122431.         sqlite3VdbeVerifyNoMallocRequired(v, ArraySize(setMeta6));

  122432.         aOp = sqlite3VdbeAddOpList(v, ArraySize(setMeta6), setMeta6, iLn);

  122433.         if( ONLY_IF_REALLOC_STRESS(aOp==0) ) break;

  122434.         aOp[0].p1 = iDb;

  122435.         aOp[1].p1 = iDb;

  122436.         aOp[2].p2 = iAddr+4;

  122437.         aOp[4].p1 = iDb;

  122438.         aOp[4].p3 = eAuto - 1;

  122439.         sqlite3VdbeUsesBtree(v, iDb);

  122440.       }

  122441.     }

  122442.     break;

  122443.   }

  122444. #endif

  122445. 

  122446.   /*

  122447.   **  PRAGMA [schema.]incremental_vacuum(N)

  122448.   **

  122449.   ** Do N steps of incremental vacuuming on a database.

  122450.   */

  122451. #ifndef SQLITE_OMIT_AUTOVACUUM

  122452.   case PragTyp_INCREMENTAL_VACUUM: {

  122453.     int iLimit, addr;

  122454.     if( zRight==0 || !sqlite3GetInt32(zRight, &iLimit) || iLimit<=0 ){

  122455.       iLimit = 0x7fffffff;

  122456.     }

  122457.     sqlite3BeginWriteOperation(pParse, 0, iDb);

  122458.     sqlite3VdbeAddOp2(v, OP_Integer, iLimit, 1);

  122459.     addr = sqlite3VdbeAddOp1(v, OP_IncrVacuum, iDb); VdbeCoverage(v);

  122460.     sqlite3VdbeAddOp1(v, OP_ResultRow, 1);

  122461.     sqlite3VdbeAddOp2(v, OP_AddImm, 1, -1);

  122462.     sqlite3VdbeAddOp2(v, OP_IfPos, 1, addr); VdbeCoverage(v);

  122463.     sqlite3VdbeJumpHere(v, addr);

  122464.     break;

  122465.   }

  122466. #endif

  122467. 

  122468. #ifndef SQLITE_OMIT_PAGER_PRAGMAS

  122469.   /*

  122470.   **  PRAGMA [schema.]cache_size

  122471.   **  PRAGMA [schema.]cache_size=N

  122472.   **

  122473.   ** The first form reports the current local setting for the

  122474.   ** page cache size. The second form sets the local

  122475.   ** page cache size value.  If N is positive then that is the

  122476.   ** number of pages in the cache.  If N is negative, then the

  122477.   ** number of pages is adjusted so that the cache uses -N kibibytes

  122478.   ** of memory.

  122479.   */

  122480.   case PragTyp_CACHE_SIZE: {

  122481.     assert( sqlite3SchemaMutexHeld(db, iDb, 0) );

  122482.     if( !zRight ){

  122483.       returnSingleInt(v, pDb->pSchema->cache_size);

  122484.     }else{

  122485.       int size = sqlite3Atoi(zRight);

  122486.       pDb->pSchema->cache_size = size;

  122487.       sqlite3BtreeSetCacheSize(pDb->pBt, pDb->pSchema->cache_size);

  122488.     }

  122489.     break;

  122490.   }

  122491. 

  122492.   /*

  122493.   **  PRAGMA [schema.]cache_spill

  122494.   **  PRAGMA cache_spill=BOOLEAN

  122495.   **  PRAGMA [schema.]cache_spill=N

  122496.   **

  122497.   ** The first form reports the current local setting for the

  122498.   ** page cache spill size. The second form turns cache spill on

  122499.   ** or off.  When turnning cache spill on, the size is set to the

  122500.   ** current cache_size.  The third form sets a spill size that

  122501.   ** may be different form the cache size.

  122502.   ** If N is positive then that is the

  122503.   ** number of pages in the cache.  If N is negative, then the

  122504.   ** number of pages is adjusted so that the cache uses -N kibibytes

  122505.   ** of memory.

  122506.   **

  122507.   ** If the number of cache_spill pages is less then the number of

  122508.   ** cache_size pages, no spilling occurs until the page count exceeds

  122509.   ** the number of cache_size pages.

  122510.   **

  122511.   ** The cache_spill=BOOLEAN setting applies to all attached schemas,

  122512.   ** not just the schema specified.

  122513.   */

  122514.   case PragTyp_CACHE_SPILL: {

  122515.     assert( sqlite3SchemaMutexHeld(db, iDb, 0) );

  122516.     if( !zRight ){

  122517.       returnSingleInt(v,

  122518.          (db->flags & SQLITE_CacheSpill)==0 ? 0 : 

  122519.             sqlite3BtreeSetSpillSize(pDb->pBt,0));

  122520.     }else{

  122521.       int size = 1;

  122522.       if( sqlite3GetInt32(zRight, &size) ){

  122523.         sqlite3BtreeSetSpillSize(pDb->pBt, size);

  122524.       }

  122525.       if( sqlite3GetBoolean(zRight, size!=0) ){

  122526.         db->flags |= SQLITE_CacheSpill;

  122527.       }else{

  122528.         db->flags &= ~(u64)SQLITE_CacheSpill;

  122529.       }

  122530.       setAllPagerFlags(db);

  122531.     }

  122532.     break;

  122533.   }

  122534. 

  122535.   /*

  122536.   **  PRAGMA [schema.]mmap_size(N)

  122537.   **

  122538.   ** Used to set mapping size limit. The mapping size limit is

  122539.   ** used to limit the aggregate size of all memory mapped regions of the

  122540.   ** database file. If this parameter is set to zero, then memory mapping

  122541.   ** is not used at all.  If N is negative, then the default memory map

  122542.   ** limit determined by sqlite3_config(SQLITE_CONFIG_MMAP_SIZE) is set.

  122543.   ** The parameter N is measured in bytes.

  122544.   **

  122545.   ** This value is advisory.  The underlying VFS is free to memory map

  122546.   ** as little or as much as it wants.  Except, if N is set to 0 then the

  122547.   ** upper layers will never invoke the xFetch interfaces to the VFS.

  122548.   */

  122549.   case PragTyp_MMAP_SIZE: {

  122550.     sqlite3_int64 sz;

  122551. #if SQLITE_MAX_MMAP_SIZE>0

  122552.     assert( sqlite3SchemaMutexHeld(db, iDb, 0) );

  122553.     if( zRight ){

  122554.       int ii;

  122555.       sqlite3DecOrHexToI64(zRight, &sz);

  122556.       if( sz<0 ) sz = sqlite3GlobalConfig.szMmap;

  122557.       if( pId2->n==0 ) db->szMmap = sz;

  122558.       for(ii=db->nDb-1; ii>=0; ii--){

  122559.         if( db->aDb[ii].pBt && (ii==iDb || pId2->n==0) ){

  122560.           sqlite3BtreeSetMmapLimit(db->aDb[ii].pBt, sz);

  122561.         }

  122562.       }

  122563.     }

  122564.     sz = -1;

  122565.     rc = sqlite3_file_control(db, zDb, SQLITE_FCNTL_MMAP_SIZE, &sz);

  122566. #else

  122567.     sz = 0;

  122568.     rc = SQLITE_OK;

  122569. #endif

  122570.     if( rc==SQLITE_OK ){

  122571.       returnSingleInt(v, sz);

  122572.     }else if( rc!=SQLITE_NOTFOUND ){

  122573.       pParse->nErr++;

  122574.       pParse->rc = rc;

  122575.     }

  122576.     break;

  122577.   }

  122578. 

  122579.   /*

  122580.   **   PRAGMA temp_store

  122581.   **   PRAGMA temp_store = "default"|"memory"|"file"

  122582.   **

  122583.   ** Return or set the local value of the temp_store flag.  Changing

  122584.   ** the local value does not make changes to the disk file and the default

  122585.   ** value will be restored the next time the database is opened.

  122586.   **

  122587.   ** Note that it is possible for the library compile-time options to

  122588.   ** override this setting

  122589.   */

  122590.   case PragTyp_TEMP_STORE: {

  122591.     if( !zRight ){

  122592.       returnSingleInt(v, db->temp_store);

  122593.     }else{

  122594.       changeTempStorage(pParse, zRight);

  122595.     }

  122596.     break;

  122597.   }

  122598. 

  122599.   /*

  122600.   **   PRAGMA temp_store_directory

  122601.   **   PRAGMA temp_store_directory = ""|"directory_name"

  122602.   **

  122603.   ** Return or set the local value of the temp_store_directory flag.  Changing

  122604.   ** the value sets a specific directory to be used for temporary files.

  122605.   ** Setting to a null string reverts to the default temporary directory search.

  122606.   ** If temporary directory is changed, then invalidateTempStorage.

  122607.   **

  122608.   */

  122609.   case PragTyp_TEMP_STORE_DIRECTORY: {

  122610.     if( !zRight ){

  122611.       returnSingleText(v, sqlite3_temp_directory);

  122612.     }else{

  122613. #ifndef SQLITE_OMIT_WSD

  122614.       if( zRight[0] ){

  122615.         int res;

  122616.         rc = sqlite3OsAccess(db->pVfs, zRight, SQLITE_ACCESS_READWRITE, &res);

  122617.         if( rc!=SQLITE_OK || res==0 ){

  122618.           sqlite3ErrorMsg(pParse, "not a writable directory");

  122619.           goto pragma_out;

  122620.         }

  122621.       }

  122622.       if( SQLITE_TEMP_STORE==0

  122623.        || (SQLITE_TEMP_STORE==1 && db->temp_store<=1)

  122624.        || (SQLITE_TEMP_STORE==2 && db->temp_store==1)

  122625.       ){

  122626.         invalidateTempStorage(pParse);

  122627.       }

  122628.       sqlite3_free(sqlite3_temp_directory);

  122629.       if( zRight[0] ){

  122630.         sqlite3_temp_directory = sqlite3_mprintf("%s", zRight);

  122631.       }else{

  122632.         sqlite3_temp_directory = 0;

  122633.       }

  122634. #endif /* SQLITE_OMIT_WSD */

  122635.     }

  122636.     break;

  122637.   }

  122638. 

  122639. #if SQLITE_OS_WIN

  122640.   /*

  122641.   **   PRAGMA data_store_directory

  122642.   **   PRAGMA data_store_directory = ""|"directory_name"

  122643.   **

  122644.   ** Return or set the local value of the data_store_directory flag.  Changing

  122645.   ** the value sets a specific directory to be used for database files that

  122646.   ** were specified with a relative pathname.  Setting to a null string reverts

  122647.   ** to the default database directory, which for database files specified with

  122648.   ** a relative path will probably be based on the current directory for the

  122649.   ** process.  Database file specified with an absolute path are not impacted

  122650.   ** by this setting, regardless of its value.

  122651.   **

  122652.   */

  122653.   case PragTyp_DATA_STORE_DIRECTORY: {

  122654.     if( !zRight ){

  122655.       returnSingleText(v, sqlite3_data_directory);

  122656.     }else{

  122657. #ifndef SQLITE_OMIT_WSD

  122658.       if( zRight[0] ){

  122659.         int res;

  122660.         rc = sqlite3OsAccess(db->pVfs, zRight, SQLITE_ACCESS_READWRITE, &res);

  122661.         if( rc!=SQLITE_OK || res==0 ){

  122662.           sqlite3ErrorMsg(pParse, "not a writable directory");

  122663.           goto pragma_out;

  122664.         }

  122665.       }

  122666.       sqlite3_free(sqlite3_data_directory);

  122667.       if( zRight[0] ){

  122668.         sqlite3_data_directory = sqlite3_mprintf("%s", zRight);

  122669.       }else{

  122670.         sqlite3_data_directory = 0;

  122671.       }

  122672. #endif /* SQLITE_OMIT_WSD */

  122673.     }

  122674.     break;

  122675.   }

  122676. #endif

  122677. 

  122678. #if SQLITE_ENABLE_LOCKING_STYLE

  122679.   /*

  122680.   **   PRAGMA [schema.]lock_proxy_file

  122681.   **   PRAGMA [schema.]lock_proxy_file = ":auto:"|"lock_file_path"

  122682.   **

  122683.   ** Return or set the value of the lock_proxy_file flag.  Changing

  122684.   ** the value sets a specific file to be used for database access locks.

  122685.   **

  122686.   */

  122687.   case PragTyp_LOCK_PROXY_FILE: {

  122688.     if( !zRight ){

  122689.       Pager *pPager = sqlite3BtreePager(pDb->pBt);

  122690.       char *proxy_file_path = NULL;

  122691.       sqlite3_file *pFile = sqlite3PagerFile(pPager);

  122692.       sqlite3OsFileControlHint(pFile, SQLITE_GET_LOCKPROXYFILE, 

  122693.                            &proxy_file_path);

  122694.       returnSingleText(v, proxy_file_path);

  122695.     }else{

  122696.       Pager *pPager = sqlite3BtreePager(pDb->pBt);

  122697.       sqlite3_file *pFile = sqlite3PagerFile(pPager);

  122698.       int res;

  122699.       if( zRight[0] ){

  122700.         res=sqlite3OsFileControl(pFile, SQLITE_SET_LOCKPROXYFILE, 

  122701.                                      zRight);

  122702.       } else {

  122703.         res=sqlite3OsFileControl(pFile, SQLITE_SET_LOCKPROXYFILE, 

  122704.                                      NULL);

  122705.       }

  122706.       if( res!=SQLITE_OK ){

  122707.         sqlite3ErrorMsg(pParse, "failed to set lock proxy file");

  122708.         goto pragma_out;

  122709.       }

  122710.     }

  122711.     break;

  122712.   }

  122713. #endif /* SQLITE_ENABLE_LOCKING_STYLE */      

  122714.     

  122715.   /*

  122716.   **   PRAGMA [schema.]synchronous

  122717.   **   PRAGMA [schema.]synchronous=OFF|ON|NORMAL|FULL|EXTRA

  122718.   **

  122719.   ** Return or set the local value of the synchronous flag.  Changing

  122720.   ** the local value does not make changes to the disk file and the

  122721.   ** default value will be restored the next time the database is

  122722.   ** opened.

  122723.   */

  122724.   case PragTyp_SYNCHRONOUS: {

  122725.     if( !zRight ){

  122726.       returnSingleInt(v, pDb->safety_level-1);

  122727.     }else{

  122728.       if( !db->autoCommit ){

  122729.         sqlite3ErrorMsg(pParse, 

  122730.             "Safety level may not be changed inside a transaction");

  122731.       }else if( iDb!=1 ){

  122732.         int iLevel = (getSafetyLevel(zRight,0,1)+1) & PAGER_SYNCHRONOUS_MASK;

  122733.         if( iLevel==0 ) iLevel = 1;

  122734.         pDb->safety_level = iLevel;

  122735.         pDb->bSyncSet = 1;

  122736.         setAllPagerFlags(db);

  122737.       }

  122738.     }

  122739.     break;

  122740.   }

  122741. #endif /* SQLITE_OMIT_PAGER_PRAGMAS */

  122742. 

  122743. #ifndef SQLITE_OMIT_FLAG_PRAGMAS

  122744.   case PragTyp_FLAG: {

  122745.     if( zRight==0 ){

  122746.       setPragmaResultColumnNames(v, pPragma);

  122747.       returnSingleInt(v, (db->flags & pPragma->iArg)!=0 );

  122748.     }else{

  122749.       u64 mask = pPragma->iArg;    /* Mask of bits to set or clear. */

  122750.       if( db->autoCommit==0 ){

  122751.         /* Foreign key support may not be enabled or disabled while not

  122752.         ** in auto-commit mode.  */

  122753.         mask &= ~(SQLITE_ForeignKeys);

  122754.       }

  122755. #if SQLITE_USER_AUTHENTICATION

  122756.       if( db->auth.authLevel==UAUTH_User ){

  122757.         /* Do not allow non-admin users to modify the schema arbitrarily */

  122758.         mask &= ~(SQLITE_WriteSchema);

  122759.       }

  122760. #endif

  122761. 

  122762.       if( sqlite3GetBoolean(zRight, 0) ){

  122763.         db->flags |= mask;

  122764.       }else{

  122765.         db->flags &= ~mask;

  122766.         if( mask==SQLITE_DeferFKs ) db->nDeferredImmCons = 0;

  122767.       }

  122768. 

  122769.       /* Many of the flag-pragmas modify the code generated by the SQL 

  122770.       ** compiler (eg. count_changes). So add an opcode to expire all

  122771.       ** compiled SQL statements after modifying a pragma value.

  122772.       */

  122773.       sqlite3VdbeAddOp0(v, OP_Expire);

  122774.       setAllPagerFlags(db);

  122775.     }

  122776.     break;

  122777.   }

  122778. #endif /* SQLITE_OMIT_FLAG_PRAGMAS */

  122779. 

  122780. #ifndef SQLITE_OMIT_SCHEMA_PRAGMAS

  122781.   /*

  122782.   **   PRAGMA table_info(<table>)

  122783.   **

  122784.   ** Return a single row for each column of the named table. The columns of

  122785.   ** the returned data set are:

  122786.   **

  122787.   ** cid:        Column id (numbered from left to right, starting at 0)

  122788.   ** name:       Column name

  122789.   ** type:       Column declaration type.

  122790.   ** notnull:    True if 'NOT NULL' is part of column declaration

  122791.   ** dflt_value: The default value for the column, if any.

  122792.   ** pk:         Non-zero for PK fields.

  122793.   */

  122794.   case PragTyp_TABLE_INFO: if( zRight ){

  122795.     Table *pTab;

  122796.     pTab = sqlite3LocateTable(pParse, LOCATE_NOERR, zRight, zDb);

  122797.     if( pTab ){

  122798.       int iTabDb = sqlite3SchemaToIndex(db, pTab->pSchema);

  122799.       int i, k;

  122800.       int nHidden = 0;

  122801.       Column *pCol;

  122802.       Index *pPk = sqlite3PrimaryKeyIndex(pTab);

  122803.       pParse->nMem = 7;

  122804.       sqlite3CodeVerifySchema(pParse, iTabDb);

  122805.       sqlite3ViewGetColumnNames(pParse, pTab);

  122806.       for(i=0, pCol=pTab->aCol; i<pTab->nCol; i++, pCol++){

  122807.         int isHidden = IsHiddenColumn(pCol);

  122808.         if( isHidden && pPragma->iArg==0 ){

  122809.           nHidden++;

  122810.           continue;

  122811.         }

  122812.         if( (pCol->colFlags & COLFLAG_PRIMKEY)==0 ){

  122813.           k = 0;

  122814.         }else if( pPk==0 ){

  122815.           k = 1;

  122816.         }else{

  122817.           for(k=1; k<=pTab->nCol && pPk->aiColumn[k-1]!=i; k++){}

  122818.         }

  122819.         assert( pCol->pDflt==0 || pCol->pDflt->op==TK_SPAN );

  122820.         sqlite3VdbeMultiLoad(v, 1, pPragma->iArg ? "issisii" : "issisi",

  122821.                i-nHidden,

  122822.                pCol->zName,

  122823.                sqlite3ColumnType(pCol,""),

  122824.                pCol->notNull ? 1 : 0,

  122825.                pCol->pDflt ? pCol->pDflt->u.zToken : 0,

  122826.                k,

  122827.                isHidden);

  122828.       }

  122829.     }

  122830.   }

  122831.   break;

  122832. 

  122833. #ifdef SQLITE_DEBUG

  122834.   case PragTyp_STATS: {

  122835.     Index *pIdx;

  122836.     HashElem *i;

  122837.     pParse->nMem = 5;

  122838.     sqlite3CodeVerifySchema(pParse, iDb);

  122839.     for(i=sqliteHashFirst(&pDb->pSchema->tblHash); i; i=sqliteHashNext(i)){

  122840.       Table *pTab = sqliteHashData(i);

  122841.       sqlite3VdbeMultiLoad(v, 1, "ssiii",

  122842.            pTab->zName,

  122843.            0,

  122844.            pTab->szTabRow,

  122845.            pTab->nRowLogEst,

  122846.            pTab->tabFlags);

  122847.       for(pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext){

  122848.         sqlite3VdbeMultiLoad(v, 2, "siiiX",

  122849.            pIdx->zName,

  122850.            pIdx->szIdxRow,

  122851.            pIdx->aiRowLogEst[0],

  122852.            pIdx->hasStat1);

  122853.         sqlite3VdbeAddOp2(v, OP_ResultRow, 1, 5);

  122854.       }

  122855.     }

  122856.   }

  122857.   break;

  122858. #endif

  122859. 

  122860.   case PragTyp_INDEX_INFO: if( zRight ){

  122861.     Index *pIdx;

  122862.     Table *pTab;

  122863.     pIdx = sqlite3FindIndex(db, zRight, zDb);

  122864.     if( pIdx ){

  122865.       int iIdxDb = sqlite3SchemaToIndex(db, pIdx->pSchema);

  122866.       int i;

  122867.       int mx;

  122868.       if( pPragma->iArg ){

  122869.         /* PRAGMA index_xinfo (newer version with more rows and columns) */

  122870.         mx = pIdx->nColumn;

  122871.         pParse->nMem = 6;

  122872.       }else{

  122873.         /* PRAGMA index_info (legacy version) */

  122874.         mx = pIdx->nKeyCol;

  122875.         pParse->nMem = 3;

  122876.       }

  122877.       pTab = pIdx->pTable;

  122878.       sqlite3CodeVerifySchema(pParse, iIdxDb);

  122879.       assert( pParse->nMem<=pPragma->nPragCName );

  122880.       for(i=0; i<mx; i++){

  122881.         i16 cnum = pIdx->aiColumn[i];

  122882.         sqlite3VdbeMultiLoad(v, 1, "iisX", i, cnum,

  122883.                              cnum<0 ? 0 : pTab->aCol[cnum].zName);

  122884.         if( pPragma->iArg ){

  122885.           sqlite3VdbeMultiLoad(v, 4, "isiX",

  122886.             pIdx->aSortOrder[i],

  122887.             pIdx->azColl[i],

  122888.             i<pIdx->nKeyCol);

  122889.         }

  122890.         sqlite3VdbeAddOp2(v, OP_ResultRow, 1, pParse->nMem);

  122891.       }

  122892.     }

  122893.   }

  122894.   break;

  122895. 

  122896.   case PragTyp_INDEX_LIST: if( zRight ){

  122897.     Index *pIdx;

  122898.     Table *pTab;

  122899.     int i;

  122900.     pTab = sqlite3FindTable(db, zRight, zDb);

  122901.     if( pTab ){

  122902.       int iTabDb = sqlite3SchemaToIndex(db, pTab->pSchema);

  122903.       pParse->nMem = 5;

  122904.       sqlite3CodeVerifySchema(pParse, iTabDb);

  122905.       for(pIdx=pTab->pIndex, i=0; pIdx; pIdx=pIdx->pNext, i++){

  122906.         const char *azOrigin[] = { "c", "u", "pk" };

  122907.         sqlite3VdbeMultiLoad(v, 1, "isisi",

  122908.            i,

  122909.            pIdx->zName,

  122910.            IsUniqueIndex(pIdx),

  122911.            azOrigin[pIdx->idxType],

  122912.            pIdx->pPartIdxWhere!=0);

  122913.       }

  122914.     }

  122915.   }

  122916.   break;

  122917. 

  122918.   case PragTyp_DATABASE_LIST: {

  122919.     int i;

  122920.     pParse->nMem = 3;

  122921.     for(i=0; i<db->nDb; i++){

  122922.       if( db->aDb[i].pBt==0 ) continue;

  122923.       assert( db->aDb[i].zDbSName!=0 );

  122924.       sqlite3VdbeMultiLoad(v, 1, "iss",

  122925.          i,

  122926.          db->aDb[i].zDbSName,

  122927.          sqlite3BtreeGetFilename(db->aDb[i].pBt));

  122928.     }

  122929.   }

  122930.   break;

  122931. 

  122932.   case PragTyp_COLLATION_LIST: {

  122933.     int i = 0;

  122934.     HashElem *p;

  122935.     pParse->nMem = 2;

  122936.     for(p=sqliteHashFirst(&db->aCollSeq); p; p=sqliteHashNext(p)){

  122937.       CollSeq *pColl = (CollSeq *)sqliteHashData(p);

  122938.       sqlite3VdbeMultiLoad(v, 1, "is", i++, pColl->zName);

  122939.     }

  122940.   }

  122941.   break;

  122942. 

  122943. #ifdef SQLITE_INTROSPECTION_PRAGMAS

  122944.   case PragTyp_FUNCTION_LIST: {

  122945.     int i;

  122946.     HashElem *j;

  122947.     FuncDef *p;

  122948.     pParse->nMem = 2;

  122949.     for(i=0; i<SQLITE_FUNC_HASH_SZ; i++){

  122950.       for(p=sqlite3BuiltinFunctions.a[i]; p; p=p->u.pHash ){

  122951.         if( p->funcFlags & SQLITE_FUNC_INTERNAL ) continue;

  122952.         sqlite3VdbeMultiLoad(v, 1, "si", p->zName, 1);

  122953.       }

  122954.     }

  122955.     for(j=sqliteHashFirst(&db->aFunc); j; j=sqliteHashNext(j)){

  122956.       p = (FuncDef*)sqliteHashData(j);

  122957.       sqlite3VdbeMultiLoad(v, 1, "si", p->zName, 0);

  122958.     }

  122959.   }

  122960.   break;

  122961. 

  122962. #ifndef SQLITE_OMIT_VIRTUALTABLE

  122963.   case PragTyp_MODULE_LIST: {

  122964.     HashElem *j;

  122965.     pParse->nMem = 1;

  122966.     for(j=sqliteHashFirst(&db->aModule); j; j=sqliteHashNext(j)){

  122967.       Module *pMod = (Module*)sqliteHashData(j);

  122968.       sqlite3VdbeMultiLoad(v, 1, "s", pMod->zName);

  122969.     }

  122970.   }

  122971.   break;

  122972. #endif /* SQLITE_OMIT_VIRTUALTABLE */

  122973. 

  122974.   case PragTyp_PRAGMA_LIST: {

  122975.     int i;

  122976.     for(i=0; i<ArraySize(aPragmaName); i++){

  122977.       sqlite3VdbeMultiLoad(v, 1, "s", aPragmaName[i].zName);

  122978.     }

  122979.   }

  122980.   break;

  122981. #endif /* SQLITE_INTROSPECTION_PRAGMAS */

  122982. 

  122983. #endif /* SQLITE_OMIT_SCHEMA_PRAGMAS */

  122984. 

  122985. #ifndef SQLITE_OMIT_FOREIGN_KEY

  122986.   case PragTyp_FOREIGN_KEY_LIST: if( zRight ){

  122987.     FKey *pFK;

  122988.     Table *pTab;

  122989.     pTab = sqlite3FindTable(db, zRight, zDb);

  122990.     if( pTab ){

  122991.       pFK = pTab->pFKey;

  122992.       if( pFK ){

  122993.         int iTabDb = sqlite3SchemaToIndex(db, pTab->pSchema);

  122994.         int i = 0; 

  122995.         pParse->nMem = 8;

  122996.         sqlite3CodeVerifySchema(pParse, iTabDb);

  122997.         while(pFK){

  122998.           int j;

  122999.           for(j=0; j<pFK->nCol; j++){

  123000.             sqlite3VdbeMultiLoad(v, 1, "iissssss",

  123001.                    i,

  123002.                    j,

  123003.                    pFK->zTo,

  123004.                    pTab->aCol[pFK->aCol[j].iFrom].zName,

  123005.                    pFK->aCol[j].zCol,

  123006.                    actionName(pFK->aAction[1]),  /* ON UPDATE */

  123007.                    actionName(pFK->aAction[0]),  /* ON DELETE */

  123008.                    "NONE");

  123009.           }

  123010.           ++i;

  123011.           pFK = pFK->pNextFrom;

  123012.         }

  123013.       }

  123014.     }

  123015.   }

  123016.   break;

  123017. #endif /* !defined(SQLITE_OMIT_FOREIGN_KEY) */

  123018. 

  123019. #ifndef SQLITE_OMIT_FOREIGN_KEY

  123020. #ifndef SQLITE_OMIT_TRIGGER

  123021.   case PragTyp_FOREIGN_KEY_CHECK: {

  123022.     FKey *pFK;             /* A foreign key constraint */

  123023.     Table *pTab;           /* Child table contain "REFERENCES" keyword */

  123024.     Table *pParent;        /* Parent table that child points to */

  123025.     Index *pIdx;           /* Index in the parent table */

  123026.     int i;                 /* Loop counter:  Foreign key number for pTab */

  123027.     int j;                 /* Loop counter:  Field of the foreign key */

  123028.     HashElem *k;           /* Loop counter:  Next table in schema */

  123029.     int x;                 /* result variable */

  123030.     int regResult;         /* 3 registers to hold a result row */

  123031.     int regKey;            /* Register to hold key for checking the FK */

  123032.     int regRow;            /* Registers to hold a row from pTab */

  123033.     int addrTop;           /* Top of a loop checking foreign keys */

  123034.     int addrOk;            /* Jump here if the key is OK */

  123035.     int *aiCols;           /* child to parent column mapping */

  123036. 

  123037.     regResult = pParse->nMem+1;

  123038.     pParse->nMem += 4;

  123039.     regKey = ++pParse->nMem;

  123040.     regRow = ++pParse->nMem;

  123041.     k = sqliteHashFirst(&db->aDb[iDb].pSchema->tblHash);

  123042.     while( k ){

  123043.       int iTabDb;

  123044.       if( zRight ){

  123045.         pTab = sqlite3LocateTable(pParse, 0, zRight, zDb);

  123046.         k = 0;

  123047.       }else{

  123048.         pTab = (Table*)sqliteHashData(k);

  123049.         k = sqliteHashNext(k);

  123050.       }

  123051.       if( pTab==0 || pTab->pFKey==0 ) continue;

  123052.       iTabDb = sqlite3SchemaToIndex(db, pTab->pSchema);

  123053.       sqlite3CodeVerifySchema(pParse, iTabDb);

  123054.       sqlite3TableLock(pParse, iTabDb, pTab->tnum, 0, pTab->zName);

  123055.       if( pTab->nCol+regRow>pParse->nMem ) pParse->nMem = pTab->nCol + regRow;

  123056.       sqlite3OpenTable(pParse, 0, iTabDb, pTab, OP_OpenRead);

  123057.       sqlite3VdbeLoadString(v, regResult, pTab->zName);

  123058.       for(i=1, pFK=pTab->pFKey; pFK; i++, pFK=pFK->pNextFrom){

  123059.         pParent = sqlite3FindTable(db, pFK->zTo, zDb);

  123060.         if( pParent==0 ) continue;

  123061.         pIdx = 0;

  123062.         sqlite3TableLock(pParse, iTabDb, pParent->tnum, 0, pParent->zName);

  123063.         x = sqlite3FkLocateIndex(pParse, pParent, pFK, &pIdx, 0);

  123064.         if( x==0 ){

  123065.           if( pIdx==0 ){

  123066.             sqlite3OpenTable(pParse, i, iTabDb, pParent, OP_OpenRead);

  123067.           }else{

  123068.             sqlite3VdbeAddOp3(v, OP_OpenRead, i, pIdx->tnum, iTabDb);

  123069.             sqlite3VdbeSetP4KeyInfo(pParse, pIdx);

  123070.           }

  123071.         }else{

  123072.           k = 0;

  123073.           break;

  123074.         }

  123075.       }

  123076.       assert( pParse->nErr>0 || pFK==0 );

  123077.       if( pFK ) break;

  123078.       if( pParse->nTab<i ) pParse->nTab = i;

  123079.       addrTop = sqlite3VdbeAddOp1(v, OP_Rewind, 0); VdbeCoverage(v);

  123080.       for(i=1, pFK=pTab->pFKey; pFK; i++, pFK=pFK->pNextFrom){

  123081.         pParent = sqlite3FindTable(db, pFK->zTo, zDb);

  123082.         pIdx = 0;

  123083.         aiCols = 0;

  123084.         if( pParent ){

  123085.           x = sqlite3FkLocateIndex(pParse, pParent, pFK, &pIdx, &aiCols);

  123086.           assert( x==0 );

  123087.         }

  123088.         addrOk = sqlite3VdbeMakeLabel(pParse);

  123089. 

  123090.         /* Generate code to read the child key values into registers

  123091.         ** regRow..regRow+n. If any of the child key values are NULL, this 

  123092.         ** row cannot cause an FK violation. Jump directly to addrOk in 

  123093.         ** this case. */

  123094.         for(j=0; j<pFK->nCol; j++){

  123095.           int iCol = aiCols ? aiCols[j] : pFK->aCol[j].iFrom;

  123096.           sqlite3ExprCodeGetColumnOfTable(v, pTab, 0, iCol, regRow+j);

  123097.           sqlite3VdbeAddOp2(v, OP_IsNull, regRow+j, addrOk); VdbeCoverage(v);

  123098.         }

  123099. 

  123100.         /* Generate code to query the parent index for a matching parent

  123101.         ** key. If a match is found, jump to addrOk. */

  123102.         if( pIdx ){

  123103.           sqlite3VdbeAddOp4(v, OP_MakeRecord, regRow, pFK->nCol, regKey,

  123104.               sqlite3IndexAffinityStr(db,pIdx), pFK->nCol);

  123105.           sqlite3VdbeAddOp4Int(v, OP_Found, i, addrOk, regKey, 0);

  123106.           VdbeCoverage(v);

  123107.         }else if( pParent ){

  123108.           int jmp = sqlite3VdbeCurrentAddr(v)+2;

  123109.           sqlite3VdbeAddOp3(v, OP_SeekRowid, i, jmp, regRow); VdbeCoverage(v);

  123110.           sqlite3VdbeGoto(v, addrOk);

  123111.           assert( pFK->nCol==1 );

  123112.         }

  123113. 

  123114.         /* Generate code to report an FK violation to the caller. */

  123115.         if( HasRowid(pTab) ){

  123116.           sqlite3VdbeAddOp2(v, OP_Rowid, 0, regResult+1);

  123117.         }else{

  123118.           sqlite3VdbeAddOp2(v, OP_Null, 0, regResult+1);

  123119.         }

  123120.         sqlite3VdbeMultiLoad(v, regResult+2, "siX", pFK->zTo, i-1);

  123121.         sqlite3VdbeAddOp2(v, OP_ResultRow, regResult, 4);

  123122.         sqlite3VdbeResolveLabel(v, addrOk);

  123123.         sqlite3DbFree(db, aiCols);

  123124.       }

  123125.       sqlite3VdbeAddOp2(v, OP_Next, 0, addrTop+1); VdbeCoverage(v);

  123126.       sqlite3VdbeJumpHere(v, addrTop);

  123127.     }

  123128.   }

  123129.   break;

  123130. #endif /* !defined(SQLITE_OMIT_TRIGGER) */

  123131. #endif /* !defined(SQLITE_OMIT_FOREIGN_KEY) */

  123132. 

  123133. #ifndef SQLITE_OMIT_CASE_SENSITIVE_LIKE_PRAGMA

  123134.   /* Reinstall the LIKE and GLOB functions.  The variant of LIKE

  123135.   ** used will be case sensitive or not depending on the RHS.

  123136.   */

  123137.   case PragTyp_CASE_SENSITIVE_LIKE: {

  123138.     if( zRight ){

  123139.       sqlite3RegisterLikeFunctions(db, sqlite3GetBoolean(zRight, 0));

  123140.     }

  123141.   }

  123142.   break;

  123143. #endif /* SQLITE_OMIT_CASE_SENSITIVE_LIKE_PRAGMA */

  123144. 

  123145. #ifndef SQLITE_INTEGRITY_CHECK_ERROR_MAX

  123146. # define SQLITE_INTEGRITY_CHECK_ERROR_MAX 100

  123147. #endif

  123148. 

  123149. #ifndef SQLITE_OMIT_INTEGRITY_CHECK

  123150.   /*    PRAGMA integrity_check

  123151.   **    PRAGMA integrity_check(N)

  123152.   **    PRAGMA quick_check

  123153.   **    PRAGMA quick_check(N)

  123154.   **

  123155.   ** Verify the integrity of the database.

  123156.   **

  123157.   ** The "quick_check" is reduced version of 

  123158.   ** integrity_check designed to detect most database corruption

  123159.   ** without the overhead of cross-checking indexes.  Quick_check

  123160.   ** is linear time wherease integrity_check is O(NlogN).

  123161.   */

  123162.   case PragTyp_INTEGRITY_CHECK: {

  123163.     int i, j, addr, mxErr;

  123164. 

  123165.     int isQuick = (sqlite3Tolower(zLeft[0])=='q');

  123166. 

  123167.     /* If the PRAGMA command was of the form "PRAGMA <db>.integrity_check",

  123168.     ** then iDb is set to the index of the database identified by <db>.

  123169.     ** In this case, the integrity of database iDb only is verified by

  123170.     ** the VDBE created below.

  123171.     **

  123172.     ** Otherwise, if the command was simply "PRAGMA integrity_check" (or

  123173.     ** "PRAGMA quick_check"), then iDb is set to 0. In this case, set iDb

  123174.     ** to -1 here, to indicate that the VDBE should verify the integrity

  123175.     ** of all attached databases.  */

  123176.     assert( iDb>=0 );

  123177.     assert( iDb==0 || pId2->z );

  123178.     if( pId2->z==0 ) iDb = -1;

  123179. 

  123180.     /* Initialize the VDBE program */

  123181.     pParse->nMem = 6;

  123182. 

  123183.     /* Set the maximum error count */

  123184.     mxErr = SQLITE_INTEGRITY_CHECK_ERROR_MAX;

  123185.     if( zRight ){

  123186.       sqlite3GetInt32(zRight, &mxErr);

  123187.       if( mxErr<=0 ){

  123188.         mxErr = SQLITE_INTEGRITY_CHECK_ERROR_MAX;

  123189.       }

  123190.     }

  123191.     sqlite3VdbeAddOp2(v, OP_Integer, mxErr-1, 1); /* reg[1] holds errors left */

  123192. 

  123193.     /* Do an integrity check on each database file */

  123194.     for(i=0; i<db->nDb; i++){

  123195.       HashElem *x;     /* For looping over tables in the schema */

  123196.       Hash *pTbls;     /* Set of all tables in the schema */

  123197.       int *aRoot;      /* Array of root page numbers of all btrees */

  123198.       int cnt = 0;     /* Number of entries in aRoot[] */

  123199.       int mxIdx = 0;   /* Maximum number of indexes for any table */

  123200. 

  123201.       if( OMIT_TEMPDB && i==1 ) continue;

  123202.       if( iDb>=0 && i!=iDb ) continue;

  123203. 

  123204.       sqlite3CodeVerifySchema(pParse, i);

  123205. 

  123206.       /* Do an integrity check of the B-Tree

  123207.       **

  123208.       ** Begin by finding the root pages numbers

  123209.       ** for all tables and indices in the database.

  123210.       */

  123211.       assert( sqlite3SchemaMutexHeld(db, i, 0) );

  123212.       pTbls = &db->aDb[i].pSchema->tblHash;

  123213.       for(cnt=0, x=sqliteHashFirst(pTbls); x; x=sqliteHashNext(x)){

  123214.         Table *pTab = sqliteHashData(x);  /* Current table */

  123215.         Index *pIdx;                      /* An index on pTab */

  123216.         int nIdx;                         /* Number of indexes on pTab */

  123217.         if( HasRowid(pTab) ) cnt++;

  123218.         for(nIdx=0, pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext, nIdx++){ cnt++; }

  123219.         if( nIdx>mxIdx ) mxIdx = nIdx;

  123220.       }

  123221.       aRoot = sqlite3DbMallocRawNN(db, sizeof(int)*(cnt+1));

  123222.       if( aRoot==0 ) break;

  123223.       for(cnt=0, x=sqliteHashFirst(pTbls); x; x=sqliteHashNext(x)){

  123224.         Table *pTab = sqliteHashData(x);

  123225.         Index *pIdx;

  123226.         if( HasRowid(pTab) ) aRoot[++cnt] = pTab->tnum;

  123227.         for(pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext){

  123228.           aRoot[++cnt] = pIdx->tnum;

  123229.         }

  123230.       }

  123231.       aRoot[0] = cnt;

  123232. 

  123233.       /* Make sure sufficient number of registers have been allocated */

  123234.       pParse->nMem = MAX( pParse->nMem, 8+mxIdx );

  123235.       sqlite3ClearTempRegCache(pParse);

  123236. 

  123237.       /* Do the b-tree integrity checks */

  123238.       sqlite3VdbeAddOp4(v, OP_IntegrityCk, 2, cnt, 1, (char*)aRoot,P4_INTARRAY);

  123239.       sqlite3VdbeChangeP5(v, (u8)i);

  123240.       addr = sqlite3VdbeAddOp1(v, OP_IsNull, 2); VdbeCoverage(v);

  123241.       sqlite3VdbeAddOp4(v, OP_String8, 0, 3, 0,

  123242.          sqlite3MPrintf(db, "*** in database %s ***\n", db->aDb[i].zDbSName),

  123243.          P4_DYNAMIC);

  123244.       sqlite3VdbeAddOp3(v, OP_Concat, 2, 3, 3);

  123245.       integrityCheckResultRow(v);

  123246.       sqlite3VdbeJumpHere(v, addr);

  123247. 

  123248.       /* Make sure all the indices are constructed correctly.

  123249.       */

  123250.       for(x=sqliteHashFirst(pTbls); x; x=sqliteHashNext(x)){

  123251.         Table *pTab = sqliteHashData(x);

  123252.         Index *pIdx, *pPk;

  123253.         Index *pPrior = 0;

  123254.         int loopTop;

  123255.         int iDataCur, iIdxCur;

  123256.         int r1 = -1;

  123257. 

  123258.         if( pTab->tnum<1 ) continue;  /* Skip VIEWs or VIRTUAL TABLEs */

  123259.         pPk = HasRowid(pTab) ? 0 : sqlite3PrimaryKeyIndex(pTab);

  123260.         sqlite3OpenTableAndIndices(pParse, pTab, OP_OpenRead, 0,

  123261.                                    1, 0, &iDataCur, &iIdxCur);

  123262.         /* reg[7] counts the number of entries in the table.

  123263.         ** reg[8+i] counts the number of entries in the i-th index 

  123264.         */

  123265.         sqlite3VdbeAddOp2(v, OP_Integer, 0, 7);

  123266.         for(j=0, pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext, j++){

  123267.           sqlite3VdbeAddOp2(v, OP_Integer, 0, 8+j); /* index entries counter */

  123268.         }

  123269.         assert( pParse->nMem>=8+j );

  123270.         assert( sqlite3NoTempsInRange(pParse,1,7+j) );

  123271.         sqlite3VdbeAddOp2(v, OP_Rewind, iDataCur, 0); VdbeCoverage(v);

  123272.         loopTop = sqlite3VdbeAddOp2(v, OP_AddImm, 7, 1);

  123273.         if( !isQuick ){

  123274.           /* Sanity check on record header decoding */

  123275.           sqlite3VdbeAddOp3(v, OP_Column, iDataCur, pTab->nCol-1, 3);

  123276.           sqlite3VdbeChangeP5(v, OPFLAG_TYPEOFARG);

  123277.         }

  123278.         /* Verify that all NOT NULL columns really are NOT NULL */

  123279.         for(j=0; j<pTab->nCol; j++){

  123280.           char *zErr;

  123281.           int jmp2;

  123282.           if( j==pTab->iPKey ) continue;

  123283.           if( pTab->aCol[j].notNull==0 ) continue;

  123284.           sqlite3ExprCodeGetColumnOfTable(v, pTab, iDataCur, j, 3);

  123285.           sqlite3VdbeChangeP5(v, OPFLAG_TYPEOFARG);

  123286.           jmp2 = sqlite3VdbeAddOp1(v, OP_NotNull, 3); VdbeCoverage(v);

  123287.           zErr = sqlite3MPrintf(db, "NULL value in %s.%s", pTab->zName,

  123288.                               pTab->aCol[j].zName);

  123289.           sqlite3VdbeAddOp4(v, OP_String8, 0, 3, 0, zErr, P4_DYNAMIC);

  123290.           integrityCheckResultRow(v);

  123291.           sqlite3VdbeJumpHere(v, jmp2);

  123292.         }

  123293.         /* Verify CHECK constraints */

  123294.         if( pTab->pCheck && (db->flags & SQLITE_IgnoreChecks)==0 ){

  123295.           ExprList *pCheck = sqlite3ExprListDup(db, pTab->pCheck, 0);

  123296.           if( db->mallocFailed==0 ){

  123297.             int addrCkFault = sqlite3VdbeMakeLabel(pParse);

  123298.             int addrCkOk = sqlite3VdbeMakeLabel(pParse);

  123299.             char *zErr;

  123300.             int k;

  123301.             pParse->iSelfTab = iDataCur + 1;

  123302.             for(k=pCheck->nExpr-1; k>0; k--){

  123303.               sqlite3ExprIfFalse(pParse, pCheck->a[k].pExpr, addrCkFault, 0);

  123304.             }

  123305.             sqlite3ExprIfTrue(pParse, pCheck->a[0].pExpr, addrCkOk, 

  123306.                 SQLITE_JUMPIFNULL);

  123307.             sqlite3VdbeResolveLabel(v, addrCkFault);

  123308.             pParse->iSelfTab = 0;

  123309.             zErr = sqlite3MPrintf(db, "CHECK constraint failed in %s",

  123310.                 pTab->zName);

  123311.             sqlite3VdbeAddOp4(v, OP_String8, 0, 3, 0, zErr, P4_DYNAMIC);

  123312.             integrityCheckResultRow(v);

  123313.             sqlite3VdbeResolveLabel(v, addrCkOk);

  123314.           }

  123315.           sqlite3ExprListDelete(db, pCheck);

  123316.         }

  123317.         if( !isQuick ){ /* Omit the remaining tests for quick_check */

  123318.           /* Validate index entries for the current row */

  123319.           for(j=0, pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext, j++){

  123320.             int jmp2, jmp3, jmp4, jmp5;

  123321.             int ckUniq = sqlite3VdbeMakeLabel(pParse);

  123322.             if( pPk==pIdx ) continue;

  123323.             r1 = sqlite3GenerateIndexKey(pParse, pIdx, iDataCur, 0, 0, &jmp3,

  123324.                                          pPrior, r1);

  123325.             pPrior = pIdx;

  123326.             sqlite3VdbeAddOp2(v, OP_AddImm, 8+j, 1);/* increment entry count */

  123327.             /* Verify that an index entry exists for the current table row */

  123328.             jmp2 = sqlite3VdbeAddOp4Int(v, OP_Found, iIdxCur+j, ckUniq, r1,

  123329.                                         pIdx->nColumn); VdbeCoverage(v);

  123330.             sqlite3VdbeLoadString(v, 3, "row ");

  123331.             sqlite3VdbeAddOp3(v, OP_Concat, 7, 3, 3);

  123332.             sqlite3VdbeLoadString(v, 4, " missing from index ");

  123333.             sqlite3VdbeAddOp3(v, OP_Concat, 4, 3, 3);

  123334.             jmp5 = sqlite3VdbeLoadString(v, 4, pIdx->zName);

  123335.             sqlite3VdbeAddOp3(v, OP_Concat, 4, 3, 3);

  123336.             jmp4 = integrityCheckResultRow(v);

  123337.             sqlite3VdbeJumpHere(v, jmp2);

  123338.             /* For UNIQUE indexes, verify that only one entry exists with the

  123339.             ** current key.  The entry is unique if (1) any column is NULL

  123340.             ** or (2) the next entry has a different key */

  123341.             if( IsUniqueIndex(pIdx) ){

  123342.               int uniqOk = sqlite3VdbeMakeLabel(pParse);

  123343.               int jmp6;

  123344.               int kk;

  123345.               for(kk=0; kk<pIdx->nKeyCol; kk++){

  123346.                 int iCol = pIdx->aiColumn[kk];

  123347.                 assert( iCol!=XN_ROWID && iCol<pTab->nCol );

  123348.                 if( iCol>=0 && pTab->aCol[iCol].notNull ) continue;

  123349.                 sqlite3VdbeAddOp2(v, OP_IsNull, r1+kk, uniqOk);

  123350.                 VdbeCoverage(v);

  123351.               }

  123352.               jmp6 = sqlite3VdbeAddOp1(v, OP_Next, iIdxCur+j); VdbeCoverage(v);

  123353.               sqlite3VdbeGoto(v, uniqOk);

  123354.               sqlite3VdbeJumpHere(v, jmp6);

  123355.               sqlite3VdbeAddOp4Int(v, OP_IdxGT, iIdxCur+j, uniqOk, r1,

  123356.                                    pIdx->nKeyCol); VdbeCoverage(v);

  123357.               sqlite3VdbeLoadString(v, 3, "non-unique entry in index ");

  123358.               sqlite3VdbeGoto(v, jmp5);

  123359.               sqlite3VdbeResolveLabel(v, uniqOk);

  123360.             }

  123361.             sqlite3VdbeJumpHere(v, jmp4);

  123362.             sqlite3ResolvePartIdxLabel(pParse, jmp3);

  123363.           }

  123364.         }

  123365.         sqlite3VdbeAddOp2(v, OP_Next, iDataCur, loopTop); VdbeCoverage(v);

  123366.         sqlite3VdbeJumpHere(v, loopTop-1);

  123367. #ifndef SQLITE_OMIT_BTREECOUNT

  123368.         if( !isQuick ){

  123369.           sqlite3VdbeLoadString(v, 2, "wrong # of entries in index ");

  123370.           for(j=0, pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext, j++){

  123371.             if( pPk==pIdx ) continue;

  123372.             sqlite3VdbeAddOp2(v, OP_Count, iIdxCur+j, 3);

  123373.             addr = sqlite3VdbeAddOp3(v, OP_Eq, 8+j, 0, 3); VdbeCoverage(v);

  123374.             sqlite3VdbeChangeP5(v, SQLITE_NOTNULL);

  123375.             sqlite3VdbeLoadString(v, 4, pIdx->zName);

  123376.             sqlite3VdbeAddOp3(v, OP_Concat, 4, 2, 3);

  123377.             integrityCheckResultRow(v);

  123378.             sqlite3VdbeJumpHere(v, addr);

  123379.           }

  123380.         }

  123381. #endif /* SQLITE_OMIT_BTREECOUNT */

  123382.       } 

  123383.     }

  123384.     {

  123385.       static const int iLn = VDBE_OFFSET_LINENO(2);

  123386.       static const VdbeOpList endCode[] = {

  123387.         { OP_AddImm,      1, 0,        0},    /* 0 */

  123388.         { OP_IfNotZero,   1, 4,        0},    /* 1 */

  123389.         { OP_String8,     0, 3,        0},    /* 2 */

  123390.         { OP_ResultRow,   3, 1,        0},    /* 3 */

  123391.         { OP_Halt,        0, 0,        0},    /* 4 */

  123392.         { OP_String8,     0, 3,        0},    /* 5 */

  123393.         { OP_Goto,        0, 3,        0},    /* 6 */

  123394.       };

  123395.       VdbeOp *aOp;

  123396. 

  123397.       aOp = sqlite3VdbeAddOpList(v, ArraySize(endCode), endCode, iLn);

  123398.       if( aOp ){

  123399.         aOp[0].p2 = 1-mxErr;

  123400.         aOp[2].p4type = P4_STATIC;

  123401.         aOp[2].p4.z = "ok";

  123402.         aOp[5].p4type = P4_STATIC;

  123403.         aOp[5].p4.z = (char*)sqlite3ErrStr(SQLITE_CORRUPT);

  123404.       }

  123405.       sqlite3VdbeChangeP3(v, 0, sqlite3VdbeCurrentAddr(v)-2);

  123406.     }

  123407.   }

  123408.   break;

  123409. #endif /* SQLITE_OMIT_INTEGRITY_CHECK */

  123410. 

  123411. #ifndef SQLITE_OMIT_UTF16

  123412.   /*

  123413.   **   PRAGMA encoding

  123414.   **   PRAGMA encoding = "utf-8"|"utf-16"|"utf-16le"|"utf-16be"

  123415.   **

  123416.   ** In its first form, this pragma returns the encoding of the main

  123417.   ** database. If the database is not initialized, it is initialized now.

  123418.   **

  123419.   ** The second form of this pragma is a no-op if the main database file

  123420.   ** has not already been initialized. In this case it sets the default

  123421.   ** encoding that will be used for the main database file if a new file

  123422.   ** is created. If an existing main database file is opened, then the

  123423.   ** default text encoding for the existing database is used.

  123424.   ** 

  123425.   ** In all cases new databases created using the ATTACH command are

  123426.   ** created to use the same default text encoding as the main database. If

  123427.   ** the main database has not been initialized and/or created when ATTACH

  123428.   ** is executed, this is done before the ATTACH operation.

  123429.   **

  123430.   ** In the second form this pragma sets the text encoding to be used in

  123431.   ** new database files created using this database handle. It is only

  123432.   ** useful if invoked immediately after the main database i

  123433.   */

  123434.   case PragTyp_ENCODING: {

  123435.     static const struct EncName {

  123436.       char *zName;

  123437.       u8 enc;

  123438.     } encnames[] = {

  123439.       { "UTF8",     SQLITE_UTF8        },

  123440.       { "UTF-8",    SQLITE_UTF8        },  /* Must be element [1] */

  123441.       { "UTF-16le", SQLITE_UTF16LE     },  /* Must be element [2] */

  123442.       { "UTF-16be", SQLITE_UTF16BE     },  /* Must be element [3] */

  123443.       { "UTF16le",  SQLITE_UTF16LE     },

  123444.       { "UTF16be",  SQLITE_UTF16BE     },

  123445.       { "UTF-16",   0                  }, /* SQLITE_UTF16NATIVE */

  123446.       { "UTF16",    0                  }, /* SQLITE_UTF16NATIVE */

  123447.       { 0, 0 }

  123448.     };

  123449.     const struct EncName *pEnc;

  123450.     if( !zRight ){    /* "PRAGMA encoding" */

  123451.       if( sqlite3ReadSchema(pParse) ) goto pragma_out;

  123452.       assert( encnames[SQLITE_UTF8].enc==SQLITE_UTF8 );

  123453.       assert( encnames[SQLITE_UTF16LE].enc==SQLITE_UTF16LE );

  123454.       assert( encnames[SQLITE_UTF16BE].enc==SQLITE_UTF16BE );

  123455.       returnSingleText(v, encnames[ENC(pParse->db)].zName);

  123456.     }else{                        /* "PRAGMA encoding = XXX" */

  123457.       /* Only change the value of sqlite.enc if the database handle is not

  123458.       ** initialized. If the main database exists, the new sqlite.enc value

  123459.       ** will be overwritten when the schema is next loaded. If it does not

  123460.       ** already exists, it will be created to use the new encoding value.

  123461.       */

  123462.       if( 

  123463.         !(DbHasProperty(db, 0, DB_SchemaLoaded)) || 

  123464.         DbHasProperty(db, 0, DB_Empty) 

  123465.       ){

  123466.         for(pEnc=&encnames[0]; pEnc->zName; pEnc++){

  123467.           if( 0==sqlite3StrICmp(zRight, pEnc->zName) ){

  123468.             SCHEMA_ENC(db) = ENC(db) =

  123469.                 pEnc->enc ? pEnc->enc : SQLITE_UTF16NATIVE;

  123470.             break;

  123471.           }

  123472.         }

  123473.         if( !pEnc->zName ){

  123474.           sqlite3ErrorMsg(pParse, "unsupported encoding: %s", zRight);

  123475.         }

  123476.       }

  123477.     }

  123478.   }

  123479.   break;

  123480. #endif /* SQLITE_OMIT_UTF16 */

  123481. 

  123482. #ifndef SQLITE_OMIT_SCHEMA_VERSION_PRAGMAS

  123483.   /*

  123484.   **   PRAGMA [schema.]schema_version

  123485.   **   PRAGMA [schema.]schema_version = <integer>

  123486.   **

  123487.   **   PRAGMA [schema.]user_version

  123488.   **   PRAGMA [schema.]user_version = <integer>

  123489.   **

  123490.   **   PRAGMA [schema.]freelist_count

  123491.   **

  123492.   **   PRAGMA [schema.]data_version

  123493.   **

  123494.   **   PRAGMA [schema.]application_id

  123495.   **   PRAGMA [schema.]application_id = <integer>

  123496.   **

  123497.   ** The pragma's schema_version and user_version are used to set or get

  123498.   ** the value of the schema-version and user-version, respectively. Both

  123499.   ** the schema-version and the user-version are 32-bit signed integers

  123500.   ** stored in the database header.

  123501.   **

  123502.   ** The schema-cookie is usually only manipulated internally by SQLite. It

  123503.   ** is incremented by SQLite whenever the database schema is modified (by

  123504.   ** creating or dropping a table or index). The schema version is used by

  123505.   ** SQLite each time a query is executed to ensure that the internal cache

  123506.   ** of the schema used when compiling the SQL query matches the schema of

  123507.   ** the database against which the compiled query is actually executed.

  123508.   ** Subverting this mechanism by using "PRAGMA schema_version" to modify

  123509.   ** the schema-version is potentially dangerous and may lead to program

  123510.   ** crashes or database corruption. Use with caution!

  123511.   **

  123512.   ** The user-version is not used internally by SQLite. It may be used by

  123513.   ** applications for any purpose.

  123514.   */

  123515.   case PragTyp_HEADER_VALUE: {

  123516.     int iCookie = pPragma->iArg;  /* Which cookie to read or write */

  123517.     sqlite3VdbeUsesBtree(v, iDb);

  123518.     if( zRight && (pPragma->mPragFlg & PragFlg_ReadOnly)==0 ){

  123519.       /* Write the specified cookie value */

  123520.       static const VdbeOpList setCookie[] = {

  123521.         { OP_Transaction,    0,  1,  0},    /* 0 */

  123522.         { OP_SetCookie,      0,  0,  0},    /* 1 */

  123523.       };

  123524.       VdbeOp *aOp;

  123525.       sqlite3VdbeVerifyNoMallocRequired(v, ArraySize(setCookie));

  123526.       aOp = sqlite3VdbeAddOpList(v, ArraySize(setCookie), setCookie, 0);

  123527.       if( ONLY_IF_REALLOC_STRESS(aOp==0) ) break;

  123528.       aOp[0].p1 = iDb;

  123529.       aOp[1].p1 = iDb;

  123530.       aOp[1].p2 = iCookie;

  123531.       aOp[1].p3 = sqlite3Atoi(zRight);

  123532.     }else{

  123533.       /* Read the specified cookie value */

  123534.       static const VdbeOpList readCookie[] = {

  123535.         { OP_Transaction,     0,  0,  0},    /* 0 */

  123536.         { OP_ReadCookie,      0,  1,  0},    /* 1 */

  123537.         { OP_ResultRow,       1,  1,  0}

  123538.       };

  123539.       VdbeOp *aOp;

  123540.       sqlite3VdbeVerifyNoMallocRequired(v, ArraySize(readCookie));

  123541.       aOp = sqlite3VdbeAddOpList(v, ArraySize(readCookie),readCookie,0);

  123542.       if( ONLY_IF_REALLOC_STRESS(aOp==0) ) break;

  123543.       aOp[0].p1 = iDb;

  123544.       aOp[1].p1 = iDb;

  123545.       aOp[1].p3 = iCookie;

  123546.       sqlite3VdbeReusable(v);

  123547.     }

  123548.   }

  123549.   break;

  123550. #endif /* SQLITE_OMIT_SCHEMA_VERSION_PRAGMAS */

  123551. 

  123552. #ifndef SQLITE_OMIT_COMPILEOPTION_DIAGS

  123553.   /*

  123554.   **   PRAGMA compile_options

  123555.   **

  123556.   ** Return the names of all compile-time options used in this build,

  123557.   ** one option per row.

  123558.   */

  123559.   case PragTyp_COMPILE_OPTIONS: {

  123560.     int i = 0;

  123561.     const char *zOpt;

  123562.     pParse->nMem = 1;

  123563.     while( (zOpt = sqlite3_compileoption_get(i++))!=0 ){

  123564.       sqlite3VdbeLoadString(v, 1, zOpt);

  123565.       sqlite3VdbeAddOp2(v, OP_ResultRow, 1, 1);

  123566.     }

  123567.     sqlite3VdbeReusable(v);

  123568.   }

  123569.   break;

  123570. #endif /* SQLITE_OMIT_COMPILEOPTION_DIAGS */

  123571. 

  123572. #ifndef SQLITE_OMIT_WAL

  123573.   /*

  123574.   **   PRAGMA [schema.]wal_checkpoint = passive|full|restart|truncate

  123575.   **

  123576.   ** Checkpoint the database.

  123577.   */

  123578.   case PragTyp_WAL_CHECKPOINT: {

  123579.     int iBt = (pId2->z?iDb:SQLITE_MAX_ATTACHED);

  123580.     int eMode = SQLITE_CHECKPOINT_PASSIVE;

  123581.     if( zRight ){

  123582.       if( sqlite3StrICmp(zRight, "full")==0 ){

  123583.         eMode = SQLITE_CHECKPOINT_FULL;

  123584.       }else if( sqlite3StrICmp(zRight, "restart")==0 ){

  123585.         eMode = SQLITE_CHECKPOINT_RESTART;

  123586.       }else if( sqlite3StrICmp(zRight, "truncate")==0 ){

  123587.         eMode = SQLITE_CHECKPOINT_TRUNCATE;

  123588.       }

  123589.     }

  123590.     pParse->nMem = 3;

  123591.     sqlite3VdbeAddOp3(v, OP_Checkpoint, iBt, eMode, 1);

  123592.     sqlite3VdbeAddOp2(v, OP_ResultRow, 1, 3);

  123593.   }

  123594.   break;

  123595. 

  123596.   /*

  123597.   **   PRAGMA wal_autocheckpoint

  123598.   **   PRAGMA wal_autocheckpoint = N

  123599.   **

  123600.   ** Configure a database connection to automatically checkpoint a database

  123601.   ** after accumulating N frames in the log. Or query for the current value

  123602.   ** of N.

  123603.   */

  123604.   case PragTyp_WAL_AUTOCHECKPOINT: {

  123605.     if( zRight ){

  123606.       sqlite3_wal_autocheckpoint(db, sqlite3Atoi(zRight));

  123607.     }

  123608.     returnSingleInt(v, 

  123609.        db->xWalCallback==sqlite3WalDefaultHook ? 

  123610.            SQLITE_PTR_TO_INT(db->pWalArg) : 0);

  123611.   }

  123612.   break;

  123613. #endif

  123614. 

  123615.   /*

  123616.   **  PRAGMA shrink_memory

  123617.   **

  123618.   ** IMPLEMENTATION-OF: R-23445-46109 This pragma causes the database

  123619.   ** connection on which it is invoked to free up as much memory as it

  123620.   ** can, by calling sqlite3_db_release_memory().

  123621.   */

  123622.   case PragTyp_SHRINK_MEMORY: {

  123623.     sqlite3_db_release_memory(db);

  123624.     break;

  123625.   }

  123626. 

  123627.   /*

  123628.   **  PRAGMA optimize

  123629.   **  PRAGMA optimize(MASK)

  123630.   **  PRAGMA schema.optimize

  123631.   **  PRAGMA schema.optimize(MASK)

  123632.   **

  123633.   ** Attempt to optimize the database.  All schemas are optimized in the first

  123634.   ** two forms, and only the specified schema is optimized in the latter two.

  123635.   **

  123636.   ** The details of optimizations performed by this pragma are expected

  123637.   ** to change and improve over time.  Applications should anticipate that

  123638.   ** this pragma will perform new optimizations in future releases.

  123639.   **

  123640.   ** The optional argument is a bitmask of optimizations to perform:

  123641.   **

  123642.   **    0x0001    Debugging mode.  Do not actually perform any optimizations

  123643.   **              but instead return one line of text for each optimization

  123644.   **              that would have been done.  Off by default.

  123645.   **

  123646.   **    0x0002    Run ANALYZE on tables that might benefit.  On by default.

  123647.   **              See below for additional information.

  123648.   **

  123649.   **    0x0004    (Not yet implemented) Record usage and performance 

  123650.   **              information from the current session in the

  123651.   **              database file so that it will be available to "optimize"

  123652.   **              pragmas run by future database connections.

  123653.   **

  123654.   **    0x0008    (Not yet implemented) Create indexes that might have

  123655.   **              been helpful to recent queries

  123656.   **

  123657.   ** The default MASK is and always shall be 0xfffe.  0xfffe means perform all

  123658.   ** of the optimizations listed above except Debug Mode, including new

  123659.   ** optimizations that have not yet been invented.  If new optimizations are

  123660.   ** ever added that should be off by default, those off-by-default 

  123661.   ** optimizations will have bitmasks of 0x10000 or larger.

  123662.   **

  123663.   ** DETERMINATION OF WHEN TO RUN ANALYZE

  123664.   **

  123665.   ** In the current implementation, a table is analyzed if only if all of

  123666.   ** the following are true:

  123667.   **

  123668.   ** (1) MASK bit 0x02 is set.

  123669.   **

  123670.   ** (2) The query planner used sqlite_stat1-style statistics for one or

  123671.   **     more indexes of the table at some point during the lifetime of

  123672.   **     the current connection.

  123673.   **

  123674.   ** (3) One or more indexes of the table are currently unanalyzed OR

  123675.   **     the number of rows in the table has increased by 25 times or more

  123676.   **     since the last time ANALYZE was run.

  123677.   **

  123678.   ** The rules for when tables are analyzed are likely to change in

  123679.   ** future releases.

  123680.   */

  123681.   case PragTyp_OPTIMIZE: {

  123682.     int iDbLast;           /* Loop termination point for the schema loop */

  123683.     int iTabCur;           /* Cursor for a table whose size needs checking */

  123684.     HashElem *k;           /* Loop over tables of a schema */

  123685.     Schema *pSchema;       /* The current schema */

  123686.     Table *pTab;           /* A table in the schema */

  123687.     Index *pIdx;           /* An index of the table */

  123688.     LogEst szThreshold;    /* Size threshold above which reanalysis is needd */

  123689.     char *zSubSql;         /* SQL statement for the OP_SqlExec opcode */

  123690.     u32 opMask;            /* Mask of operations to perform */

  123691. 

  123692.     if( zRight ){

  123693.       opMask = (u32)sqlite3Atoi(zRight);

  123694.       if( (opMask & 0x02)==0 ) break;

  123695.     }else{

  123696.       opMask = 0xfffe;

  123697.     }

  123698.     iTabCur = pParse->nTab++;

  123699.     for(iDbLast = zDb?iDb:db->nDb-1; iDb<=iDbLast; iDb++){

  123700.       if( iDb==1 ) continue;

  123701.       sqlite3CodeVerifySchema(pParse, iDb);

  123702.       pSchema = db->aDb[iDb].pSchema;

  123703.       for(k=sqliteHashFirst(&pSchema->tblHash); k; k=sqliteHashNext(k)){

  123704.         pTab = (Table*)sqliteHashData(k);

  123705. 

  123706.         /* If table pTab has not been used in a way that would benefit from

  123707.         ** having analysis statistics during the current session, then skip it.

  123708.         ** This also has the effect of skipping virtual tables and views */

  123709.         if( (pTab->tabFlags & TF_StatsUsed)==0 ) continue;

  123710. 

  123711.         /* Reanalyze if the table is 25 times larger than the last analysis */

  123712.         szThreshold = pTab->nRowLogEst + 46; assert( sqlite3LogEst(25)==46 );

  123713.         for(pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext){

  123714.           if( !pIdx->hasStat1 ){

  123715.             szThreshold = 0; /* Always analyze if any index lacks statistics */

  123716.             break;

  123717.           }

  123718.         }

  123719.         if( szThreshold ){

  123720.           sqlite3OpenTable(pParse, iTabCur, iDb, pTab, OP_OpenRead);

  123721.           sqlite3VdbeAddOp3(v, OP_IfSmaller, iTabCur, 

  123722.                          sqlite3VdbeCurrentAddr(v)+2+(opMask&1), szThreshold);

  123723.           VdbeCoverage(v);

  123724.         }

  123725.         zSubSql = sqlite3MPrintf(db, "ANALYZE \"%w\".\"%w\"",

  123726.                                  db->aDb[iDb].zDbSName, pTab->zName);

  123727.         if( opMask & 0x01 ){

  123728.           int r1 = sqlite3GetTempReg(pParse);

  123729.           sqlite3VdbeAddOp4(v, OP_String8, 0, r1, 0, zSubSql, P4_DYNAMIC);

  123730.           sqlite3VdbeAddOp2(v, OP_ResultRow, r1, 1);

  123731.         }else{

  123732.           sqlite3VdbeAddOp4(v, OP_SqlExec, 0, 0, 0, zSubSql, P4_DYNAMIC);

  123733.         }

  123734.       }

  123735.     }

  123736.     sqlite3VdbeAddOp0(v, OP_Expire);

  123737.     break;

  123738.   }

  123739. 

  123740.   /*

  123741.   **   PRAGMA busy_timeout

  123742.   **   PRAGMA busy_timeout = N

  123743.   **

  123744.   ** Call sqlite3_busy_timeout(db, N).  Return the current timeout value

  123745.   ** if one is set.  If no busy handler or a different busy handler is set

  123746.   ** then 0 is returned.  Setting the busy_timeout to 0 or negative

  123747.   ** disables the timeout.

  123748.   */

  123749.   /*case PragTyp_BUSY_TIMEOUT*/ default: {

  123750.     assert( pPragma->ePragTyp==PragTyp_BUSY_TIMEOUT );

  123751.     if( zRight ){

  123752.       sqlite3_busy_timeout(db, sqlite3Atoi(zRight));

  123753.     }

  123754.     returnSingleInt(v, db->busyTimeout);

  123755.     break;

  123756.   }

  123757. 

  123758.   /*

  123759.   **   PRAGMA soft_heap_limit

  123760.   **   PRAGMA soft_heap_limit = N

  123761.   **

  123762.   ** IMPLEMENTATION-OF: R-26343-45930 This pragma invokes the

  123763.   ** sqlite3_soft_heap_limit64() interface with the argument N, if N is

  123764.   ** specified and is a non-negative integer.

  123765.   ** IMPLEMENTATION-OF: R-64451-07163 The soft_heap_limit pragma always

  123766.   ** returns the same integer that would be returned by the

  123767.   ** sqlite3_soft_heap_limit64(-1) C-language function.

  123768.   */

  123769.   case PragTyp_SOFT_HEAP_LIMIT: {

  123770.     sqlite3_int64 N;

  123771.     if( zRight && sqlite3DecOrHexToI64(zRight, &N)==SQLITE_OK ){

  123772.       sqlite3_soft_heap_limit64(N);

  123773.     }

  123774.     returnSingleInt(v, sqlite3_soft_heap_limit64(-1));

  123775.     break;

  123776.   }

  123777. 

  123778.   /*

  123779.   **   PRAGMA threads

  123780.   **   PRAGMA threads = N

  123781.   **

  123782.   ** Configure the maximum number of worker threads.  Return the new

  123783.   ** maximum, which might be less than requested.

  123784.   */

  123785.   case PragTyp_THREADS: {

  123786.     sqlite3_int64 N;

  123787.     if( zRight

  123788.      && sqlite3DecOrHexToI64(zRight, &N)==SQLITE_OK

  123789.      && N>=0

  123790.     ){

  123791.       sqlite3_limit(db, SQLITE_LIMIT_WORKER_THREADS, (int)(N&0x7fffffff));

  123792.     }

  123793.     returnSingleInt(v, sqlite3_limit(db, SQLITE_LIMIT_WORKER_THREADS, -1));

  123794.     break;

  123795.   }

  123796. 

  123797. #if defined(SQLITE_DEBUG) || defined(SQLITE_TEST)

  123798.   /*

  123799.   ** Report the current state of file logs for all databases

  123800.   */

  123801.   case PragTyp_LOCK_STATUS: {

  123802.     static const char *const azLockName[] = {

  123803.       "unlocked", "shared", "reserved", "pending", "exclusive"

  123804.     };

  123805.     int i;

  123806.     pParse->nMem = 2;

  123807.     for(i=0; i<db->nDb; i++){

  123808.       Btree *pBt;

  123809.       const char *zState = "unknown";

  123810.       int j;

  123811.       if( db->aDb[i].zDbSName==0 ) continue;

  123812.       pBt = db->aDb[i].pBt;

  123813.       if( pBt==0 || sqlite3BtreePager(pBt)==0 ){

  123814.         zState = "closed";

  123815.       }else if( sqlite3_file_control(db, i ? db->aDb[i].zDbSName : 0, 

  123816.                                      SQLITE_FCNTL_LOCKSTATE, &j)==SQLITE_OK ){

  123817.          zState = azLockName[j];

  123818.       }

  123819.       sqlite3VdbeMultiLoad(v, 1, "ss", db->aDb[i].zDbSName, zState);

  123820.     }

  123821.     break;

  123822.   }

  123823. #endif

  123824. 

  123825. #ifdef SQLITE_HAS_CODEC

  123826.   /* Pragma        iArg

  123827.   ** ----------   ------

  123828.   **  key           0

  123829.   **  rekey         1

  123830.   **  hexkey        2

  123831.   **  hexrekey      3

  123832.   **  textkey       4

  123833.   **  textrekey     5

  123834.   */

  123835.   case PragTyp_KEY: {

  123836.     if( zRight ){

  123837.       char zBuf[40];

  123838.       const char *zKey = zRight;

  123839.       int n;

  123840.       if( pPragma->iArg==2 || pPragma->iArg==3 ){

  123841.         u8 iByte;

  123842.         int i;

  123843.         for(i=0, iByte=0; i<sizeof(zBuf)*2 && sqlite3Isxdigit(zRight[i]); i++){

  123844.           iByte = (iByte<<4) + sqlite3HexToInt(zRight[i]);

  123845.           if( (i&1)!=0 ) zBuf[i/2] = iByte;

  123846.         }

  123847.         zKey = zBuf;

  123848.         n = i/2;

  123849.       }else{

  123850.         n = pPragma->iArg<4 ? sqlite3Strlen30(zRight) : -1;

  123851.       }

  123852.       if( (pPragma->iArg & 1)==0 ){

  123853.         rc = sqlite3_key_v2(db, zDb, zKey, n);

  123854.       }else{

  123855.         rc = sqlite3_rekey_v2(db, zDb, zKey, n);

  123856.       }

  123857.       if( rc==SQLITE_OK && n!=0 ){

  123858.         sqlite3VdbeSetNumCols(v, 1);

  123859.         sqlite3VdbeSetColName(v, 0, COLNAME_NAME, "ok", SQLITE_STATIC);

  123860.         returnSingleText(v, "ok");

  123861.       }

  123862.     }

  123863.     break;

  123864.   }

  123865. #endif

  123866. #if defined(SQLITE_HAS_CODEC) || defined(SQLITE_ENABLE_CEROD)

  123867.   case PragTyp_ACTIVATE_EXTENSIONS: if( zRight ){

  123868. #ifdef SQLITE_HAS_CODEC

  123869.     if( sqlite3StrNICmp(zRight, "see-", 4)==0 ){

  123870.       sqlite3_activate_see(&zRight[4]);

  123871.     }

  123872. #endif

  123873. #ifdef SQLITE_ENABLE_CEROD

  123874.     if( sqlite3StrNICmp(zRight, "cerod-", 6)==0 ){

  123875.       sqlite3_activate_cerod(&zRight[6]);

  123876.     }

  123877. #endif

  123878.   }

  123879.   break;

  123880. #endif

  123881. 

  123882.   } /* End of the PRAGMA switch */

  123883. 

  123884.   /* The following block is a no-op unless SQLITE_DEBUG is defined. Its only

  123885.   ** purpose is to execute assert() statements to verify that if the

  123886.   ** PragFlg_NoColumns1 flag is set and the caller specified an argument

  123887.   ** to the PRAGMA, the implementation has not added any OP_ResultRow 

  123888.   ** instructions to the VM.  */

  123889.   if( (pPragma->mPragFlg & PragFlg_NoColumns1) && zRight ){

  123890.     sqlite3VdbeVerifyNoResultRow(v);

  123891.   }

  123892. 

  123893. pragma_out:

  123894.   sqlite3DbFree(db, zLeft);

  123895.   sqlite3DbFree(db, zRight);

  123896. }

  123897. #ifndef SQLITE_OMIT_VIRTUALTABLE

  123898. /*****************************************************************************

  123899. ** Implementation of an eponymous virtual table that runs a pragma.

  123900. **

  123901. */

  123902. typedef struct PragmaVtab PragmaVtab;

  123903. typedef struct PragmaVtabCursor PragmaVtabCursor;

  123904. struct PragmaVtab {

  123905.   sqlite3_vtab base;        /* Base class.  Must be first */

  123906.   sqlite3 *db;              /* The database connection to which it belongs */

  123907.   const PragmaName *pName;  /* Name of the pragma */

  123908.   u8 nHidden;               /* Number of hidden columns */

  123909.   u8 iHidden;               /* Index of the first hidden column */

  123910. };

  123911. struct PragmaVtabCursor {

  123912.   sqlite3_vtab_cursor base; /* Base class.  Must be first */

  123913.   sqlite3_stmt *pPragma;    /* The pragma statement to run */

  123914.   sqlite_int64 iRowid;      /* Current rowid */

  123915.   char *azArg[2];           /* Value of the argument and schema */

  123916. };

  123917. 

  123918. /* 

  123919. ** Pragma virtual table module xConnect method.

  123920. */

  123921. static int pragmaVtabConnect(

  123922.   sqlite3 *db,

  123923.   void *pAux,

  123924.   int argc, const char *const*argv,

  123925.   sqlite3_vtab **ppVtab,

  123926.   char **pzErr

  123927. ){

  123928.   const PragmaName *pPragma = (const PragmaName*)pAux;

  123929.   PragmaVtab *pTab = 0;

  123930.   int rc;

  123931.   int i, j;

  123932.   char cSep = '(';

  123933.   StrAccum acc;

  123934.   char zBuf[200];

  123935. 

  123936.   UNUSED_PARAMETER(argc);

  123937.   UNUSED_PARAMETER(argv);

  123938.   sqlite3StrAccumInit(&acc, 0, zBuf, sizeof(zBuf), 0);

  123939.   sqlite3_str_appendall(&acc, "CREATE TABLE x");

  123940.   for(i=0, j=pPragma->iPragCName; i<pPragma->nPragCName; i++, j++){

  123941.     sqlite3_str_appendf(&acc, "%c\"%s\"", cSep, pragCName[j]);

  123942.     cSep = ',';

  123943.   }

  123944.   if( i==0 ){

  123945.     sqlite3_str_appendf(&acc, "(\"%s\"", pPragma->zName);

  123946.     i++;

  123947.   }

  123948.   j = 0;

  123949.   if( pPragma->mPragFlg & PragFlg_Result1 ){

  123950.     sqlite3_str_appendall(&acc, ",arg HIDDEN");

  123951.     j++;

  123952.   }

  123953.   if( pPragma->mPragFlg & (PragFlg_SchemaOpt|PragFlg_SchemaReq) ){

  123954.     sqlite3_str_appendall(&acc, ",schema HIDDEN");

  123955.     j++;

  123956.   }

  123957.   sqlite3_str_append(&acc, ")", 1);

  123958.   sqlite3StrAccumFinish(&acc);

  123959.   assert( strlen(zBuf) < sizeof(zBuf)-1 );

  123960.   rc = sqlite3_declare_vtab(db, zBuf);

  123961.   if( rc==SQLITE_OK ){

  123962.     pTab = (PragmaVtab*)sqlite3_malloc(sizeof(PragmaVtab));

  123963.     if( pTab==0 ){

  123964.       rc = SQLITE_NOMEM;

  123965.     }else{

  123966.       memset(pTab, 0, sizeof(PragmaVtab));

  123967.       pTab->pName = pPragma;

  123968.       pTab->db = db;

  123969.       pTab->iHidden = i;

  123970.       pTab->nHidden = j;

  123971.     }

  123972.   }else{

  123973.     *pzErr = sqlite3_mprintf("%s", sqlite3_errmsg(db));

  123974.   }

  123975. 

  123976.   *ppVtab = (sqlite3_vtab*)pTab;

  123977.   return rc;

  123978. }

  123979. 

  123980. /* 

  123981. ** Pragma virtual table module xDisconnect method.

  123982. */

  123983. static int pragmaVtabDisconnect(sqlite3_vtab *pVtab){

  123984.   PragmaVtab *pTab = (PragmaVtab*)pVtab;

  123985.   sqlite3_free(pTab);

  123986.   return SQLITE_OK;

  123987. }

  123988. 

  123989. /* Figure out the best index to use to search a pragma virtual table.

  123990. **

  123991. ** There are not really any index choices.  But we want to encourage the

  123992. ** query planner to give == constraints on as many hidden parameters as

  123993. ** possible, and especially on the first hidden parameter.  So return a

  123994. ** high cost if hidden parameters are unconstrained.

  123995. */

  123996. static int pragmaVtabBestIndex(sqlite3_vtab *tab, sqlite3_index_info *pIdxInfo){

  123997.   PragmaVtab *pTab = (PragmaVtab*)tab;

  123998.   const struct sqlite3_index_constraint *pConstraint;

  123999.   int i, j;

  124000.   int seen[2];

  124001. 

  124002.   pIdxInfo->estimatedCost = (double)1;

  124003.   if( pTab->nHidden==0 ){ return SQLITE_OK; }

  124004.   pConstraint = pIdxInfo->aConstraint;

  124005.   seen[0] = 0;

  124006.   seen[1] = 0;

  124007.   for(i=0; i<pIdxInfo->nConstraint; i++, pConstraint++){

  124008.     if( pConstraint->usable==0 ) continue;

  124009.     if( pConstraint->op!=SQLITE_INDEX_CONSTRAINT_EQ ) continue;

  124010.     if( pConstraint->iColumn < pTab->iHidden ) continue;

  124011.     j = pConstraint->iColumn - pTab->iHidden;

  124012.     assert( j < 2 );

  124013.     seen[j] = i+1;

  124014.   }

  124015.   if( seen[0]==0 ){

  124016.     pIdxInfo->estimatedCost = (double)2147483647;

  124017.     pIdxInfo->estimatedRows = 2147483647;

  124018.     return SQLITE_OK;

  124019.   }

  124020.   j = seen[0]-1;

  124021.   pIdxInfo->aConstraintUsage[j].argvIndex = 1;

  124022.   pIdxInfo->aConstraintUsage[j].omit = 1;

  124023.   if( seen[1]==0 ) return SQLITE_OK;

  124024.   pIdxInfo->estimatedCost = (double)20;

  124025.   pIdxInfo->estimatedRows = 20;

  124026.   j = seen[1]-1;

  124027.   pIdxInfo->aConstraintUsage[j].argvIndex = 2;

  124028.   pIdxInfo->aConstraintUsage[j].omit = 1;

  124029.   return SQLITE_OK;

  124030. }

  124031. 

  124032. /* Create a new cursor for the pragma virtual table */

  124033. static int pragmaVtabOpen(sqlite3_vtab *pVtab, sqlite3_vtab_cursor **ppCursor){

  124034.   PragmaVtabCursor *pCsr;

  124035.   pCsr = (PragmaVtabCursor*)sqlite3_malloc(sizeof(*pCsr));

  124036.   if( pCsr==0 ) return SQLITE_NOMEM;

  124037.   memset(pCsr, 0, sizeof(PragmaVtabCursor));

  124038.   pCsr->base.pVtab = pVtab;

  124039.   *ppCursor = &pCsr->base;

  124040.   return SQLITE_OK;

  124041. }

  124042. 

  124043. /* Clear all content from pragma virtual table cursor. */

  124044. static void pragmaVtabCursorClear(PragmaVtabCursor *pCsr){

  124045.   int i;

  124046.   sqlite3_finalize(pCsr->pPragma);

  124047.   pCsr->pPragma = 0;

  124048.   for(i=0; i<ArraySize(pCsr->azArg); i++){

  124049.     sqlite3_free(pCsr->azArg[i]);

  124050.     pCsr->azArg[i] = 0;

  124051.   }

  124052. }

  124053. 

  124054. /* Close a pragma virtual table cursor */

  124055. static int pragmaVtabClose(sqlite3_vtab_cursor *cur){

  124056.   PragmaVtabCursor *pCsr = (PragmaVtabCursor*)cur;

  124057.   pragmaVtabCursorClear(pCsr);

  124058.   sqlite3_free(pCsr);

  124059.   return SQLITE_OK;

  124060. }

  124061. 

  124062. /* Advance the pragma virtual table cursor to the next row */

  124063. static int pragmaVtabNext(sqlite3_vtab_cursor *pVtabCursor){

  124064.   PragmaVtabCursor *pCsr = (PragmaVtabCursor*)pVtabCursor;

  124065.   int rc = SQLITE_OK;

  124066. 

  124067.   /* Increment the xRowid value */

  124068.   pCsr->iRowid++;

  124069.   assert( pCsr->pPragma );

  124070.   if( SQLITE_ROW!=sqlite3_step(pCsr->pPragma) ){

  124071.     rc = sqlite3_finalize(pCsr->pPragma);

  124072.     pCsr->pPragma = 0;

  124073.     pragmaVtabCursorClear(pCsr);

  124074.   }

  124075.   return rc;

  124076. }

  124077. 

  124078. /* 

  124079. ** Pragma virtual table module xFilter method.

  124080. */

  124081. static int pragmaVtabFilter(

  124082.   sqlite3_vtab_cursor *pVtabCursor, 

  124083.   int idxNum, const char *idxStr,

  124084.   int argc, sqlite3_value **argv

  124085. ){

  124086.   PragmaVtabCursor *pCsr = (PragmaVtabCursor*)pVtabCursor;

  124087.   PragmaVtab *pTab = (PragmaVtab*)(pVtabCursor->pVtab);

  124088.   int rc;

  124089.   int i, j;

  124090.   StrAccum acc;

  124091.   char *zSql;

  124092. 

  124093.   UNUSED_PARAMETER(idxNum);

  124094.   UNUSED_PARAMETER(idxStr);

  124095.   pragmaVtabCursorClear(pCsr);

  124096.   j = (pTab->pName->mPragFlg & PragFlg_Result1)!=0 ? 0 : 1;

  124097.   for(i=0; i<argc; i++, j++){

  124098.     const char *zText = (const char*)sqlite3_value_text(argv[i]);

  124099.     assert( j<ArraySize(pCsr->azArg) );

  124100.     assert( pCsr->azArg[j]==0 );

  124101.     if( zText ){

  124102.       pCsr->azArg[j] = sqlite3_mprintf("%s", zText);

  124103.       if( pCsr->azArg[j]==0 ){

  124104.         return SQLITE_NOMEM;

  124105.       }

  124106.     }

  124107.   }

  124108.   sqlite3StrAccumInit(&acc, 0, 0, 0, pTab->db->aLimit[SQLITE_LIMIT_SQL_LENGTH]);

  124109.   sqlite3_str_appendall(&acc, "PRAGMA ");

  124110.   if( pCsr->azArg[1] ){

  124111.     sqlite3_str_appendf(&acc, "%Q.", pCsr->azArg[1]);

  124112.   }

  124113.   sqlite3_str_appendall(&acc, pTab->pName->zName);

  124114.   if( pCsr->azArg[0] ){

  124115.     sqlite3_str_appendf(&acc, "=%Q", pCsr->azArg[0]);

  124116.   }

  124117.   zSql = sqlite3StrAccumFinish(&acc);

  124118.   if( zSql==0 ) return SQLITE_NOMEM;

  124119.   rc = sqlite3_prepare_v2(pTab->db, zSql, -1, &pCsr->pPragma, 0);

  124120.   sqlite3_free(zSql);

  124121.   if( rc!=SQLITE_OK ){

  124122.     pTab->base.zErrMsg = sqlite3_mprintf("%s", sqlite3_errmsg(pTab->db));

  124123.     return rc;

  124124.   }

  124125.   return pragmaVtabNext(pVtabCursor);

  124126. }

  124127. 

  124128. /*

  124129. ** Pragma virtual table module xEof method.

  124130. */

  124131. static int pragmaVtabEof(sqlite3_vtab_cursor *pVtabCursor){

  124132.   PragmaVtabCursor *pCsr = (PragmaVtabCursor*)pVtabCursor;

  124133.   return (pCsr->pPragma==0);

  124134. }

  124135. 

  124136. /* The xColumn method simply returns the corresponding column from

  124137. ** the PRAGMA.  

  124138. */

  124139. static int pragmaVtabColumn(

  124140.   sqlite3_vtab_cursor *pVtabCursor, 

  124141.   sqlite3_context *ctx, 

  124142.   int i

  124143. ){

  124144.   PragmaVtabCursor *pCsr = (PragmaVtabCursor*)pVtabCursor;

  124145.   PragmaVtab *pTab = (PragmaVtab*)(pVtabCursor->pVtab);

  124146.   if( i<pTab->iHidden ){

  124147.     sqlite3_result_value(ctx, sqlite3_column_value(pCsr->pPragma, i));

  124148.   }else{

  124149.     sqlite3_result_text(ctx, pCsr->azArg[i-pTab->iHidden],-1,SQLITE_TRANSIENT);

  124150.   }

  124151.   return SQLITE_OK;

  124152. }

  124153. 

  124154. /* 

  124155. ** Pragma virtual table module xRowid method.

  124156. */

  124157. static int pragmaVtabRowid(sqlite3_vtab_cursor *pVtabCursor, sqlite_int64 *p){

  124158.   PragmaVtabCursor *pCsr = (PragmaVtabCursor*)pVtabCursor;

  124159.   *p = pCsr->iRowid;

  124160.   return SQLITE_OK;

  124161. }

  124162. 

  124163. /* The pragma virtual table object */

  124164. static const sqlite3_module pragmaVtabModule = {

  124165.   0,                           /* iVersion */

  124166.   0,                           /* xCreate - create a table */

  124167.   pragmaVtabConnect,           /* xConnect - connect to an existing table */

  124168.   pragmaVtabBestIndex,         /* xBestIndex - Determine search strategy */

  124169.   pragmaVtabDisconnect,        /* xDisconnect - Disconnect from a table */

  124170.   0,                           /* xDestroy - Drop a table */

  124171.   pragmaVtabOpen,              /* xOpen - open a cursor */

  124172.   pragmaVtabClose,             /* xClose - close a cursor */

  124173.   pragmaVtabFilter,            /* xFilter - configure scan constraints */

  124174.   pragmaVtabNext,              /* xNext - advance a cursor */

  124175.   pragmaVtabEof,               /* xEof */

  124176.   pragmaVtabColumn,            /* xColumn - read data */

  124177.   pragmaVtabRowid,             /* xRowid - read data */

  124178.   0,                           /* xUpdate - write data */

  124179.   0,                           /* xBegin - begin transaction */

  124180.   0,                           /* xSync - sync transaction */

  124181.   0,                           /* xCommit - commit transaction */

  124182.   0,                           /* xRollback - rollback transaction */

  124183.   0,                           /* xFindFunction - function overloading */

  124184.   0,                           /* xRename - rename the table */

  124185.   0,                           /* xSavepoint */

  124186.   0,                           /* xRelease */

  124187.   0,                           /* xRollbackTo */

  124188.   0                            /* xShadowName */

  124189. };

  124190. 

  124191. /*

  124192. ** Check to see if zTabName is really the name of a pragma.  If it is,

  124193. ** then register an eponymous virtual table for that pragma and return

  124194. ** a pointer to the Module object for the new virtual table.

  124195. */

  124196. SQLITE_PRIVATE Module *sqlite3PragmaVtabRegister(sqlite3 *db, const char *zName){

  124197.   const PragmaName *pName;

  124198.   assert( sqlite3_strnicmp(zName, "pragma_", 7)==0 );

  124199.   pName = pragmaLocate(zName+7);

  124200.   if( pName==0 ) return 0;

  124201.   if( (pName->mPragFlg & (PragFlg_Result0|PragFlg_Result1))==0 ) return 0;

  124202.   assert( sqlite3HashFind(&db->aModule, zName)==0 );

  124203.   return sqlite3VtabCreateModule(db, zName, &pragmaVtabModule, (void*)pName, 0);

  124204. }

  124205. 

  124206. #endif /* SQLITE_OMIT_VIRTUALTABLE */

  124207. 

  124208. #endif /* SQLITE_OMIT_PRAGMA */

  124209. 

  124210. /************** End of pragma.c **********************************************/

  124211. /************** Begin file prepare.c *****************************************/

  124212. /*

  124213. ** 2005 May 25

  124214. **

  124215. ** The author disclaims copyright to this source code.  In place of

  124216. ** a legal notice, here is a blessing:

  124217. **

  124218. **    May you do good and not evil.

  124219. **    May you find forgiveness for yourself and forgive others.

  124220. **    May you share freely, never taking more than you give.

  124221. **

  124222. *************************************************************************

  124223. ** This file contains the implementation of the sqlite3_prepare()

  124224. ** interface, and routines that contribute to loading the database schema

  124225. ** from disk.

  124226. */

  124227. /* #include "sqliteInt.h" */

  124228. 

  124229. /*

  124230. ** Fill the InitData structure with an error message that indicates

  124231. ** that the database is corrupt.

  124232. */

  124233. static void corruptSchema(

  124234.   InitData *pData,     /* Initialization context */

  124235.   const char *zObj,    /* Object being parsed at the point of error */

  124236.   const char *zExtra   /* Error information */

  124237. ){

  124238.   sqlite3 *db = pData->db;

  124239.   if( db->mallocFailed ){

  124240.     pData->rc = SQLITE_NOMEM_BKPT;

  124241.   }else if( pData->pzErrMsg[0]!=0 ){

  124242.     /* A error message has already been generated.  Do not overwrite it */

  124243.   }else if( pData->mInitFlags & INITFLAG_AlterTable ){

  124244.     *pData->pzErrMsg = sqlite3DbStrDup(db, zExtra);

  124245.     pData->rc = SQLITE_ERROR;

  124246.   }else if( db->flags & SQLITE_WriteSchema ){

  124247.     pData->rc = SQLITE_CORRUPT_BKPT;

  124248.   }else{

  124249.     char *z;

  124250.     if( zObj==0 ) zObj = "?";

  124251.     z = sqlite3MPrintf(db, "malformed database schema (%s)", zObj);

  124252.     if( zExtra && zExtra[0] ) z = sqlite3MPrintf(db, "%z - %s", z, zExtra);

  124253.     *pData->pzErrMsg = z;

  124254.     pData->rc = SQLITE_CORRUPT_BKPT;

  124255.   }

  124256. }

  124257. 

  124258. /*

  124259. ** Check to see if any sibling index (another index on the same table)

  124260. ** of pIndex has the same root page number, and if it does, return true.

  124261. ** This would indicate a corrupt schema.

  124262. */

  124263. SQLITE_PRIVATE int sqlite3IndexHasDuplicateRootPage(Index *pIndex){

  124264.   Index *p;

  124265.   for(p=pIndex->pTable->pIndex; p; p=p->pNext){

  124266.     if( p->tnum==pIndex->tnum && p!=pIndex ) return 1;

  124267.   }

  124268.   return 0;

  124269. }

  124270. 

  124271. /*

  124272. ** This is the callback routine for the code that initializes the

  124273. ** database.  See sqlite3Init() below for additional information.

  124274. ** This routine is also called from the OP_ParseSchema opcode of the VDBE.

  124275. **

  124276. ** Each callback contains the following information:

  124277. **

  124278. **     argv[0] = name of thing being created

  124279. **     argv[1] = root page number for table or index. 0 for trigger or view.

  124280. **     argv[2] = SQL text for the CREATE statement.

  124281. **

  124282. */

  124283. SQLITE_PRIVATE int sqlite3InitCallback(void *pInit, int argc, char **argv, char **NotUsed){

  124284.   InitData *pData = (InitData*)pInit;

  124285.   sqlite3 *db = pData->db;

  124286.   int iDb = pData->iDb;

  124287. 

  124288.   assert( argc==3 );

  124289.   UNUSED_PARAMETER2(NotUsed, argc);

  124290.   assert( sqlite3_mutex_held(db->mutex) );

  124291.   DbClearProperty(db, iDb, DB_Empty);

  124292.   pData->nInitRow++;

  124293.   if( db->mallocFailed ){

  124294.     corruptSchema(pData, argv[0], 0);

  124295.     return 1;

  124296.   }

  124297. 

  124298.   assert( iDb>=0 && iDb<db->nDb );

  124299.   if( argv==0 ) return 0;   /* Might happen if EMPTY_RESULT_CALLBACKS are on */

  124300.   if( argv[1]==0 ){

  124301.     corruptSchema(pData, argv[0], 0);

  124302.   }else if( sqlite3_strnicmp(argv[2],"create ",7)==0 ){

  124303.     /* Call the parser to process a CREATE TABLE, INDEX or VIEW.

  124304.     ** But because db->init.busy is set to 1, no VDBE code is generated

  124305.     ** or executed.  All the parser does is build the internal data

  124306.     ** structures that describe the table, index, or view.

  124307.     */

  124308.     int rc;

  124309.     u8 saved_iDb = db->init.iDb;

  124310.     sqlite3_stmt *pStmt;

  124311.     TESTONLY(int rcp);            /* Return code from sqlite3_prepare() */

  124312. 

  124313.     assert( db->init.busy );

  124314.     db->init.iDb = iDb;

  124315.     db->init.newTnum = sqlite3Atoi(argv[1]);

  124316.     db->init.orphanTrigger = 0;

  124317.     TESTONLY(rcp = ) sqlite3_prepare(db, argv[2], -1, &pStmt, 0);

  124318.     rc = db->errCode;

  124319.     assert( (rc&0xFF)==(rcp&0xFF) );

  124320.     db->init.iDb = saved_iDb;

  124321.     /* assert( saved_iDb==0 || (db->mDbFlags & DBFLAG_Vacuum)!=0 ); */

  124322.     if( SQLITE_OK!=rc ){

  124323.       if( db->init.orphanTrigger ){

  124324.         assert( iDb==1 );

  124325.       }else{

  124326.         pData->rc = rc;

  124327.         if( rc==SQLITE_NOMEM ){

  124328.           sqlite3OomFault(db);

  124329.         }else if( rc!=SQLITE_INTERRUPT && (rc&0xFF)!=SQLITE_LOCKED ){

  124330.           corruptSchema(pData, argv[0], sqlite3_errmsg(db));

  124331.         }

  124332.       }

  124333.     }

  124334.     sqlite3_finalize(pStmt);

  124335.   }else if( argv[0]==0 || (argv[2]!=0 && argv[2][0]!=0) ){

  124336.     corruptSchema(pData, argv[0], 0);

  124337.   }else{

  124338.     /* If the SQL column is blank it means this is an index that

  124339.     ** was created to be the PRIMARY KEY or to fulfill a UNIQUE

  124340.     ** constraint for a CREATE TABLE.  The index should have already

  124341.     ** been created when we processed the CREATE TABLE.  All we have

  124342.     ** to do here is record the root page number for that index.

  124343.     */

  124344.     Index *pIndex;

  124345.     pIndex = sqlite3FindIndex(db, argv[0], db->aDb[iDb].zDbSName);

  124346.     if( pIndex==0

  124347.      || sqlite3GetInt32(argv[1],&pIndex->tnum)==0

  124348.      || pIndex->tnum<2

  124349.      || sqlite3IndexHasDuplicateRootPage(pIndex)

  124350.     ){

  124351.       corruptSchema(pData, argv[0], pIndex?"invalid rootpage":"orphan index");

  124352.     }

  124353.   }

  124354.   return 0;

  124355. }

  124356. 

  124357. /*

  124358. ** Attempt to read the database schema and initialize internal

  124359. ** data structures for a single database file.  The index of the

  124360. ** database file is given by iDb.  iDb==0 is used for the main

  124361. ** database.  iDb==1 should never be used.  iDb>=2 is used for

  124362. ** auxiliary databases.  Return one of the SQLITE_ error codes to

  124363. ** indicate success or failure.

  124364. */

  124365. SQLITE_PRIVATE int sqlite3InitOne(sqlite3 *db, int iDb, char **pzErrMsg, u32 mFlags){

  124366.   int rc;

  124367.   int i;

  124368. #ifndef SQLITE_OMIT_DEPRECATED

  124369.   int size;

  124370. #endif

  124371.   Db *pDb;

  124372.   char const *azArg[4];

  124373.   int meta[5];

  124374.   InitData initData;

  124375.   const char *zMasterName;

  124376.   int openedTransaction = 0;

  124377. 

  124378.   assert( (db->mDbFlags & DBFLAG_SchemaKnownOk)==0 );

  124379.   assert( iDb>=0 && iDb<db->nDb );

  124380.   assert( db->aDb[iDb].pSchema );

  124381.   assert( sqlite3_mutex_held(db->mutex) );

  124382.   assert( iDb==1 || sqlite3BtreeHoldsMutex(db->aDb[iDb].pBt) );

  124383. 

  124384.   db->init.busy = 1;

  124385. 

  124386.   /* Construct the in-memory representation schema tables (sqlite_master or

  124387.   ** sqlite_temp_master) by invoking the parser directly.  The appropriate

  124388.   ** table name will be inserted automatically by the parser so we can just

  124389.   ** use the abbreviation "x" here.  The parser will also automatically tag

  124390.   ** the schema table as read-only. */

  124391.   azArg[0] = zMasterName = SCHEMA_TABLE(iDb);

  124392.   azArg[1] = "1";

  124393.   azArg[2] = "CREATE TABLE x(type text,name text,tbl_name text,"

  124394.                             "rootpage int,sql text)";

  124395.   azArg[3] = 0;

  124396.   initData.db = db;

  124397.   initData.iDb = iDb;

  124398.   initData.rc = SQLITE_OK;

  124399.   initData.pzErrMsg = pzErrMsg;

  124400.   initData.mInitFlags = mFlags;

  124401.   initData.nInitRow = 0;

  124402.   sqlite3InitCallback(&initData, 3, (char **)azArg, 0);

  124403.   if( initData.rc ){

  124404.     rc = initData.rc;

  124405.     goto error_out;

  124406.   }

  124407. 

  124408.   /* Create a cursor to hold the database open

  124409.   */

  124410.   pDb = &db->aDb[iDb];

  124411.   if( pDb->pBt==0 ){

  124412.     assert( iDb==1 );

  124413.     DbSetProperty(db, 1, DB_SchemaLoaded);

  124414.     rc = SQLITE_OK;

  124415.     goto error_out;

  124416.   }

  124417. 

  124418.   /* If there is not already a read-only (or read-write) transaction opened

  124419.   ** on the b-tree database, open one now. If a transaction is opened, it 

  124420.   ** will be closed before this function returns.  */

  124421.   sqlite3BtreeEnter(pDb->pBt);

  124422.   if( !sqlite3BtreeIsInReadTrans(pDb->pBt) ){

  124423.     rc = sqlite3BtreeBeginTrans(pDb->pBt, 0, 0);

  124424.     if( rc!=SQLITE_OK ){

  124425.       sqlite3SetString(pzErrMsg, db, sqlite3ErrStr(rc));

  124426.       goto initone_error_out;

  124427.     }

  124428.     openedTransaction = 1;

  124429.   }

  124430. 

  124431.   /* Get the database meta information.

  124432.   **

  124433.   ** Meta values are as follows:

  124434.   **    meta[0]   Schema cookie.  Changes with each schema change.

  124435.   **    meta[1]   File format of schema layer.

  124436.   **    meta[2]   Size of the page cache.

  124437.   **    meta[3]   Largest rootpage (auto/incr_vacuum mode)

  124438.   **    meta[4]   Db text encoding. 1:UTF-8 2:UTF-16LE 3:UTF-16BE

  124439.   **    meta[5]   User version

  124440.   **    meta[6]   Incremental vacuum mode

  124441.   **    meta[7]   unused

  124442.   **    meta[8]   unused

  124443.   **    meta[9]   unused

  124444.   **

  124445.   ** Note: The #defined SQLITE_UTF* symbols in sqliteInt.h correspond to

  124446.   ** the possible values of meta[4].

  124447.   */

  124448.   for(i=0; i<ArraySize(meta); i++){

  124449.     sqlite3BtreeGetMeta(pDb->pBt, i+1, (u32 *)&meta[i]);

  124450.   }

  124451.   if( (db->flags & SQLITE_ResetDatabase)!=0 ){

  124452.     memset(meta, 0, sizeof(meta));

  124453.   }

  124454.   pDb->pSchema->schema_cookie = meta[BTREE_SCHEMA_VERSION-1];

  124455. 

  124456.   /* If opening a non-empty database, check the text encoding. For the

  124457.   ** main database, set sqlite3.enc to the encoding of the main database.

  124458.   ** For an attached db, it is an error if the encoding is not the same

  124459.   ** as sqlite3.enc.

  124460.   */

  124461.   if( meta[BTREE_TEXT_ENCODING-1] ){  /* text encoding */

  124462.     if( iDb==0 ){

  124463. #ifndef SQLITE_OMIT_UTF16

  124464.       u8 encoding;

  124465.       /* If opening the main database, set ENC(db). */

  124466.       encoding = (u8)meta[BTREE_TEXT_ENCODING-1] & 3;

  124467.       if( encoding==0 ) encoding = SQLITE_UTF8;

  124468.       ENC(db) = encoding;

  124469. #else

  124470.       ENC(db) = SQLITE_UTF8;

  124471. #endif

  124472.     }else{

  124473.       /* If opening an attached database, the encoding much match ENC(db) */

  124474.       if( meta[BTREE_TEXT_ENCODING-1]!=ENC(db) ){

  124475.         sqlite3SetString(pzErrMsg, db, "attached databases must use the same"

  124476.             " text encoding as main database");

  124477.         rc = SQLITE_ERROR;

  124478.         goto initone_error_out;

  124479.       }

  124480.     }

  124481.   }else{

  124482.     DbSetProperty(db, iDb, DB_Empty);

  124483.   }

  124484.   pDb->pSchema->enc = ENC(db);

  124485. 

  124486.   if( pDb->pSchema->cache_size==0 ){

  124487. #ifndef SQLITE_OMIT_DEPRECATED

  124488.     size = sqlite3AbsInt32(meta[BTREE_DEFAULT_CACHE_SIZE-1]);

  124489.     if( size==0 ){ size = SQLITE_DEFAULT_CACHE_SIZE; }

  124490.     pDb->pSchema->cache_size = size;

  124491. #else

  124492.     pDb->pSchema->cache_size = SQLITE_DEFAULT_CACHE_SIZE;

  124493. #endif

  124494.     sqlite3BtreeSetCacheSize(pDb->pBt, pDb->pSchema->cache_size);

  124495.   }

  124496. 

  124497.   /*

  124498.   ** file_format==1    Version 3.0.0.

  124499.   ** file_format==2    Version 3.1.3.  // ALTER TABLE ADD COLUMN

  124500.   ** file_format==3    Version 3.1.4.  // ditto but with non-NULL defaults

  124501.   ** file_format==4    Version 3.3.0.  // DESC indices.  Boolean constants

  124502.   */

  124503.   pDb->pSchema->file_format = (u8)meta[BTREE_FILE_FORMAT-1];

  124504.   if( pDb->pSchema->file_format==0 ){

  124505.     pDb->pSchema->file_format = 1;

  124506.   }

  124507.   if( pDb->pSchema->file_format>SQLITE_MAX_FILE_FORMAT ){

  124508.     sqlite3SetString(pzErrMsg, db, "unsupported file format");

  124509.     rc = SQLITE_ERROR;

  124510.     goto initone_error_out;

  124511.   }

  124512. 

  124513.   /* Ticket #2804:  When we open a database in the newer file format,

  124514.   ** clear the legacy_file_format pragma flag so that a VACUUM will

  124515.   ** not downgrade the database and thus invalidate any descending

  124516.   ** indices that the user might have created.

  124517.   */

  124518.   if( iDb==0 && meta[BTREE_FILE_FORMAT-1]>=4 ){

  124519.     db->flags &= ~(u64)SQLITE_LegacyFileFmt;

  124520.   }

  124521. 

  124522.   /* Read the schema information out of the schema tables

  124523.   */

  124524.   assert( db->init.busy );

  124525.   {

  124526.     char *zSql;

  124527.     zSql = sqlite3MPrintf(db, 

  124528.         "SELECT name, rootpage, sql FROM \"%w\".%s ORDER BY rowid",

  124529.         db->aDb[iDb].zDbSName, zMasterName);

  124530. #ifndef SQLITE_OMIT_AUTHORIZATION

  124531.     {

  124532.       sqlite3_xauth xAuth;

  124533.       xAuth = db->xAuth;

  124534.       db->xAuth = 0;

  124535. #endif

  124536.       rc = sqlite3_exec(db, zSql, sqlite3InitCallback, &initData, 0);

  124537. #ifndef SQLITE_OMIT_AUTHORIZATION

  124538.       db->xAuth = xAuth;

  124539.     }

  124540. #endif

  124541.     if( rc==SQLITE_OK ) rc = initData.rc;

  124542.     sqlite3DbFree(db, zSql);

  124543. #ifndef SQLITE_OMIT_ANALYZE

  124544.     if( rc==SQLITE_OK ){

  124545.       sqlite3AnalysisLoad(db, iDb);

  124546.     }

  124547. #endif

  124548.   }

  124549.   if( db->mallocFailed ){

  124550.     rc = SQLITE_NOMEM_BKPT;

  124551.     sqlite3ResetAllSchemasOfConnection(db);

  124552.   }

  124553.   if( rc==SQLITE_OK || (db->flags&SQLITE_NoSchemaError)){

  124554.     /* Black magic: If the SQLITE_NoSchemaError flag is set, then consider

  124555.     ** the schema loaded, even if errors occurred. In this situation the 

  124556.     ** current sqlite3_prepare() operation will fail, but the following one

  124557.     ** will attempt to compile the supplied statement against whatever subset

  124558.     ** of the schema was loaded before the error occurred. The primary

  124559.     ** purpose of this is to allow access to the sqlite_master table

  124560.     ** even when its contents have been corrupted.

  124561.     */

  124562.     DbSetProperty(db, iDb, DB_SchemaLoaded);

  124563.     rc = SQLITE_OK;

  124564.   }

  124565. 

  124566.   /* Jump here for an error that occurs after successfully allocating

  124567.   ** curMain and calling sqlite3BtreeEnter(). For an error that occurs

  124568.   ** before that point, jump to error_out.

  124569.   */

  124570. initone_error_out:

  124571.   if( openedTransaction ){

  124572.     sqlite3BtreeCommit(pDb->pBt);

  124573.   }

  124574.   sqlite3BtreeLeave(pDb->pBt);

  124575. 

  124576. error_out:

  124577.   if( rc ){

  124578.     if( rc==SQLITE_NOMEM || rc==SQLITE_IOERR_NOMEM ){

  124579.       sqlite3OomFault(db);

  124580.     }

  124581.     sqlite3ResetOneSchema(db, iDb);

  124582.   }

  124583.   db->init.busy = 0;

  124584.   return rc;

  124585. }

  124586. 

  124587. /*

  124588. ** Initialize all database files - the main database file, the file

  124589. ** used to store temporary tables, and any additional database files

  124590. ** created using ATTACH statements.  Return a success code.  If an

  124591. ** error occurs, write an error message into *pzErrMsg.

  124592. **

  124593. ** After a database is initialized, the DB_SchemaLoaded bit is set

  124594. ** bit is set in the flags field of the Db structure. If the database

  124595. ** file was of zero-length, then the DB_Empty flag is also set.

  124596. */

  124597. SQLITE_PRIVATE int sqlite3Init(sqlite3 *db, char **pzErrMsg){

  124598.   int i, rc;

  124599.   int commit_internal = !(db->mDbFlags&DBFLAG_SchemaChange);

  124600.   

  124601.   assert( sqlite3_mutex_held(db->mutex) );

  124602.   assert( sqlite3BtreeHoldsMutex(db->aDb[0].pBt) );

  124603.   assert( db->init.busy==0 );

  124604.   ENC(db) = SCHEMA_ENC(db);

  124605.   assert( db->nDb>0 );

  124606.   /* Do the main schema first */

  124607.   if( !DbHasProperty(db, 0, DB_SchemaLoaded) ){

  124608.     rc = sqlite3InitOne(db, 0, pzErrMsg, 0);

  124609.     if( rc ) return rc;

  124610.   }

  124611.   /* All other schemas after the main schema. The "temp" schema must be last */

  124612.   for(i=db->nDb-1; i>0; i--){

  124613.     assert( i==1 || sqlite3BtreeHoldsMutex(db->aDb[i].pBt) );

  124614.     if( !DbHasProperty(db, i, DB_SchemaLoaded) ){

  124615.       rc = sqlite3InitOne(db, i, pzErrMsg, 0);

  124616.       if( rc ) return rc;

  124617.     }

  124618.   }

  124619.   if( commit_internal ){

  124620.     sqlite3CommitInternalChanges(db);

  124621.   }

  124622.   return SQLITE_OK;

  124623. }

  124624. 

  124625. /*

  124626. ** This routine is a no-op if the database schema is already initialized.

  124627. ** Otherwise, the schema is loaded. An error code is returned.

  124628. */

  124629. SQLITE_PRIVATE int sqlite3ReadSchema(Parse *pParse){

  124630.   int rc = SQLITE_OK;

  124631.   sqlite3 *db = pParse->db;

  124632.   assert( sqlite3_mutex_held(db->mutex) );

  124633.   if( !db->init.busy ){

  124634.     rc = sqlite3Init(db, &pParse->zErrMsg);

  124635.     if( rc!=SQLITE_OK ){

  124636.       pParse->rc = rc;

  124637.       pParse->nErr++;

  124638.     }else if( db->noSharedCache ){

  124639.       db->mDbFlags |= DBFLAG_SchemaKnownOk;

  124640.     }

  124641.   }

  124642.   return rc;

  124643. }

  124644. 

  124645. 

  124646. /*

  124647. ** Check schema cookies in all databases.  If any cookie is out

  124648. ** of date set pParse->rc to SQLITE_SCHEMA.  If all schema cookies

  124649. ** make no changes to pParse->rc.

  124650. */

  124651. static void schemaIsValid(Parse *pParse){

  124652.   sqlite3 *db = pParse->db;

  124653.   int iDb;

  124654.   int rc;

  124655.   int cookie;

  124656. 

  124657.   assert( pParse->checkSchema );

  124658.   assert( sqlite3_mutex_held(db->mutex) );

  124659.   for(iDb=0; iDb<db->nDb; iDb++){

  124660.     int openedTransaction = 0;         /* True if a transaction is opened */

  124661.     Btree *pBt = db->aDb[iDb].pBt;     /* Btree database to read cookie from */

  124662.     if( pBt==0 ) continue;

  124663. 

  124664.     /* If there is not already a read-only (or read-write) transaction opened

  124665.     ** on the b-tree database, open one now. If a transaction is opened, it 

  124666.     ** will be closed immediately after reading the meta-value. */

  124667.     if( !sqlite3BtreeIsInReadTrans(pBt) ){

  124668.       rc = sqlite3BtreeBeginTrans(pBt, 0, 0);

  124669.       if( rc==SQLITE_NOMEM || rc==SQLITE_IOERR_NOMEM ){

  124670.         sqlite3OomFault(db);

  124671.       }

  124672.       if( rc!=SQLITE_OK ) return;

  124673.       openedTransaction = 1;

  124674.     }

  124675. 

  124676.     /* Read the schema cookie from the database. If it does not match the 

  124677.     ** value stored as part of the in-memory schema representation,

  124678.     ** set Parse.rc to SQLITE_SCHEMA. */

  124679.     sqlite3BtreeGetMeta(pBt, BTREE_SCHEMA_VERSION, (u32 *)&cookie);

  124680.     assert( sqlite3SchemaMutexHeld(db, iDb, 0) );

  124681.     if( cookie!=db->aDb[iDb].pSchema->schema_cookie ){

  124682.       sqlite3ResetOneSchema(db, iDb);

  124683.       pParse->rc = SQLITE_SCHEMA;

  124684.     }

  124685. 

  124686.     /* Close the transaction, if one was opened. */

  124687.     if( openedTransaction ){

  124688.       sqlite3BtreeCommit(pBt);

  124689.     }

  124690.   }

  124691. }

  124692. 

  124693. /*

  124694. ** Convert a schema pointer into the iDb index that indicates

  124695. ** which database file in db->aDb[] the schema refers to.

  124696. **

  124697. ** If the same database is attached more than once, the first

  124698. ** attached database is returned.

  124699. */

  124700. SQLITE_PRIVATE int sqlite3SchemaToIndex(sqlite3 *db, Schema *pSchema){

  124701.   int i = -1000000;

  124702. 

  124703.   /* If pSchema is NULL, then return -1000000. This happens when code in 

  124704.   ** expr.c is trying to resolve a reference to a transient table (i.e. one

  124705.   ** created by a sub-select). In this case the return value of this 

  124706.   ** function should never be used.

  124707.   **

  124708.   ** We return -1000000 instead of the more usual -1 simply because using

  124709.   ** -1000000 as the incorrect index into db->aDb[] is much 

  124710.   ** more likely to cause a segfault than -1 (of course there are assert()

  124711.   ** statements too, but it never hurts to play the odds).

  124712.   */

  124713.   assert( sqlite3_mutex_held(db->mutex) );

  124714.   if( pSchema ){

  124715.     for(i=0; 1; i++){

  124716.       assert( i<db->nDb );

  124717.       if( db->aDb[i].pSchema==pSchema ){

  124718.         break;

  124719.       }

  124720.     }

  124721.     assert( i>=0 && i<db->nDb );

  124722.   }

  124723.   return i;

  124724. }

  124725. 

  124726. /*

  124727. ** Free all memory allocations in the pParse object

  124728. */

  124729. SQLITE_PRIVATE void sqlite3ParserReset(Parse *pParse){

  124730.   sqlite3 *db = pParse->db;

  124731.   sqlite3DbFree(db, pParse->aLabel);

  124732.   sqlite3ExprListDelete(db, pParse->pConstExpr);

  124733.   if( db ){

  124734.     assert( db->lookaside.bDisable >= pParse->disableLookaside );

  124735.     db->lookaside.bDisable -= pParse->disableLookaside;

  124736.   }

  124737.   pParse->disableLookaside = 0;

  124738. }

  124739. 

  124740. /*

  124741. ** Compile the UTF-8 encoded SQL statement zSql into a statement handle.

  124742. */

  124743. static int sqlite3Prepare(

  124744.   sqlite3 *db,              /* Database handle. */

  124745.   const char *zSql,         /* UTF-8 encoded SQL statement. */

  124746.   int nBytes,               /* Length of zSql in bytes. */

  124747.   u32 prepFlags,            /* Zero or more SQLITE_PREPARE_* flags */

  124748.   Vdbe *pReprepare,         /* VM being reprepared */

  124749.   sqlite3_stmt **ppStmt,    /* OUT: A pointer to the prepared statement */

  124750.   const char **pzTail       /* OUT: End of parsed string */

  124751. ){

  124752.   char *zErrMsg = 0;        /* Error message */

  124753.   int rc = SQLITE_OK;       /* Result code */

  124754.   int i;                    /* Loop counter */

  124755.   Parse sParse;             /* Parsing context */

  124756. 

  124757.   memset(&sParse, 0, PARSE_HDR_SZ);

  124758.   memset(PARSE_TAIL(&sParse), 0, PARSE_TAIL_SZ);

  124759.   sParse.pReprepare = pReprepare;

  124760.   assert( ppStmt && *ppStmt==0 );

  124761.   /* assert( !db->mallocFailed ); // not true with SQLITE_USE_ALLOCA */

  124762.   assert( sqlite3_mutex_held(db->mutex) );

  124763. 

  124764.   /* For a long-term use prepared statement avoid the use of

  124765.   ** lookaside memory.

  124766.   */

  124767.   if( prepFlags & SQLITE_PREPARE_PERSISTENT ){

  124768.     sParse.disableLookaside++;

  124769.     db->lookaside.bDisable++;

  124770.   }

  124771.   sParse.disableVtab = (prepFlags & SQLITE_PREPARE_NO_VTAB)!=0;

  124772. 

  124773.   /* Check to verify that it is possible to get a read lock on all

  124774.   ** database schemas.  The inability to get a read lock indicates that

  124775.   ** some other database connection is holding a write-lock, which in

  124776.   ** turn means that the other connection has made uncommitted changes

  124777.   ** to the schema.

  124778.   **

  124779.   ** Were we to proceed and prepare the statement against the uncommitted

  124780.   ** schema changes and if those schema changes are subsequently rolled

  124781.   ** back and different changes are made in their place, then when this

  124782.   ** prepared statement goes to run the schema cookie would fail to detect

  124783.   ** the schema change.  Disaster would follow.

  124784.   **

  124785.   ** This thread is currently holding mutexes on all Btrees (because

  124786.   ** of the sqlite3BtreeEnterAll() in sqlite3LockAndPrepare()) so it

  124787.   ** is not possible for another thread to start a new schema change

  124788.   ** while this routine is running.  Hence, we do not need to hold 

  124789.   ** locks on the schema, we just need to make sure nobody else is 

  124790.   ** holding them.

  124791.   **

  124792.   ** Note that setting READ_UNCOMMITTED overrides most lock detection,

  124793.   ** but it does *not* override schema lock detection, so this all still

  124794.   ** works even if READ_UNCOMMITTED is set.

  124795.   */

  124796.   for(i=0; i<db->nDb; i++) {

  124797.     Btree *pBt = db->aDb[i].pBt;

  124798.     if( pBt ){

  124799.       assert( sqlite3BtreeHoldsMutex(pBt) );

  124800.       rc = sqlite3BtreeSchemaLocked(pBt);

  124801.       if( rc ){

  124802.         const char *zDb = db->aDb[i].zDbSName;

  124803.         sqlite3ErrorWithMsg(db, rc, "database schema is locked: %s", zDb);

  124804.         testcase( db->flags & SQLITE_ReadUncommit );

  124805.         goto end_prepare;

  124806.       }

  124807.     }

  124808.   }

  124809. 

  124810.   sqlite3VtabUnlockList(db);

  124811. 

  124812.   sParse.db = db;

  124813.   if( nBytes>=0 && (nBytes==0 || zSql[nBytes-1]!=0) ){

  124814.     char *zSqlCopy;

  124815.     int mxLen = db->aLimit[SQLITE_LIMIT_SQL_LENGTH];

  124816.     testcase( nBytes==mxLen );

  124817.     testcase( nBytes==mxLen+1 );

  124818.     if( nBytes>mxLen ){

  124819.       sqlite3ErrorWithMsg(db, SQLITE_TOOBIG, "statement too long");

  124820.       rc = sqlite3ApiExit(db, SQLITE_TOOBIG);

  124821.       goto end_prepare;

  124822.     }

  124823.     zSqlCopy = sqlite3DbStrNDup(db, zSql, nBytes);

  124824.     if( zSqlCopy ){

  124825.       sqlite3RunParser(&sParse, zSqlCopy, &zErrMsg);

  124826.       sParse.zTail = &zSql[sParse.zTail-zSqlCopy];

  124827.       sqlite3DbFree(db, zSqlCopy);

  124828.     }else{

  124829.       sParse.zTail = &zSql[nBytes];

  124830.     }

  124831.   }else{

  124832.     sqlite3RunParser(&sParse, zSql, &zErrMsg);

  124833.   }

  124834.   assert( 0==sParse.nQueryLoop );

  124835. 

  124836.   if( sParse.rc==SQLITE_DONE ) sParse.rc = SQLITE_OK;

  124837.   if( sParse.checkSchema ){

  124838.     schemaIsValid(&sParse);

  124839.   }

  124840.   if( db->mallocFailed ){

  124841.     sParse.rc = SQLITE_NOMEM_BKPT;

  124842.   }

  124843.   if( pzTail ){

  124844.     *pzTail = sParse.zTail;

  124845.   }

  124846.   rc = sParse.rc;

  124847. 

  124848. #ifndef SQLITE_OMIT_EXPLAIN

  124849.   if( rc==SQLITE_OK && sParse.pVdbe && sParse.explain ){

  124850.     static const char * const azColName[] = {

  124851.        "addr", "opcode", "p1", "p2", "p3", "p4", "p5", "comment",

  124852.        "id", "parent", "notused", "detail"

  124853.     };

  124854.     int iFirst, mx;

  124855.     if( sParse.explain==2 ){

  124856.       sqlite3VdbeSetNumCols(sParse.pVdbe, 4);

  124857.       iFirst = 8;

  124858.       mx = 12;

  124859.     }else{

  124860.       sqlite3VdbeSetNumCols(sParse.pVdbe, 8);

  124861.       iFirst = 0;

  124862.       mx = 8;

  124863.     }

  124864.     for(i=iFirst; i<mx; i++){

  124865.       sqlite3VdbeSetColName(sParse.pVdbe, i-iFirst, COLNAME_NAME,

  124866.                             azColName[i], SQLITE_STATIC);

  124867.     }

  124868.   }

  124869. #endif

  124870. 

  124871.   if( db->init.busy==0 ){

  124872.     sqlite3VdbeSetSql(sParse.pVdbe, zSql, (int)(sParse.zTail-zSql), prepFlags);

  124873.   }

  124874.   if( sParse.pVdbe && (rc!=SQLITE_OK || db->mallocFailed) ){

  124875.     sqlite3VdbeFinalize(sParse.pVdbe);

  124876.     assert(!(*ppStmt));

  124877.   }else{

  124878.     *ppStmt = (sqlite3_stmt*)sParse.pVdbe;

  124879.   }

  124880. 

  124881.   if( zErrMsg ){

  124882.     sqlite3ErrorWithMsg(db, rc, "%s", zErrMsg);

  124883.     sqlite3DbFree(db, zErrMsg);

  124884.   }else{

  124885.     sqlite3Error(db, rc);

  124886.   }

  124887. 

  124888.   /* Delete any TriggerPrg structures allocated while parsing this statement. */

  124889.   while( sParse.pTriggerPrg ){

  124890.     TriggerPrg *pT = sParse.pTriggerPrg;

  124891.     sParse.pTriggerPrg = pT->pNext;

  124892.     sqlite3DbFree(db, pT);

  124893.   }

  124894. 

  124895. end_prepare:

  124896. 

  124897.   sqlite3ParserReset(&sParse);

  124898.   return rc;

  124899. }

  124900. static int sqlite3LockAndPrepare(

  124901.   sqlite3 *db,              /* Database handle. */

  124902.   const char *zSql,         /* UTF-8 encoded SQL statement. */

  124903.   int nBytes,               /* Length of zSql in bytes. */

  124904.   u32 prepFlags,            /* Zero or more SQLITE_PREPARE_* flags */

  124905.   Vdbe *pOld,               /* VM being reprepared */

  124906.   sqlite3_stmt **ppStmt,    /* OUT: A pointer to the prepared statement */

  124907.   const char **pzTail       /* OUT: End of parsed string */

  124908. ){

  124909.   int rc;

  124910.   int cnt = 0;

  124911. 

  124912. #ifdef SQLITE_ENABLE_API_ARMOR

  124913.   if( ppStmt==0 ) return SQLITE_MISUSE_BKPT;

  124914. #endif

  124915.   *ppStmt = 0;

  124916.   if( !sqlite3SafetyCheckOk(db)||zSql==0 ){

  124917.     return SQLITE_MISUSE_BKPT;

  124918.   }

  124919.   sqlite3_mutex_enter(db->mutex);

  124920.   sqlite3BtreeEnterAll(db);

  124921.   do{

  124922.     /* Make multiple attempts to compile the SQL, until it either succeeds

  124923.     ** or encounters a permanent error.  A schema problem after one schema

  124924.     ** reset is considered a permanent error. */

  124925.     rc = sqlite3Prepare(db, zSql, nBytes, prepFlags, pOld, ppStmt, pzTail);

  124926.     assert( rc==SQLITE_OK || *ppStmt==0 );

  124927.   }while( rc==SQLITE_ERROR_RETRY

  124928.        || (rc==SQLITE_SCHEMA && (sqlite3ResetOneSchema(db,-1), cnt++)==0) );

  124929.   sqlite3BtreeLeaveAll(db);

  124930.   rc = sqlite3ApiExit(db, rc);

  124931.   assert( (rc&db->errMask)==rc );

  124932.   sqlite3_mutex_leave(db->mutex);

  124933.   return rc;

  124934. }

  124935. 

  124936. 

  124937. /*

  124938. ** Rerun the compilation of a statement after a schema change.

  124939. **

  124940. ** If the statement is successfully recompiled, return SQLITE_OK. Otherwise,

  124941. ** if the statement cannot be recompiled because another connection has

  124942. ** locked the sqlite3_master table, return SQLITE_LOCKED. If any other error

  124943. ** occurs, return SQLITE_SCHEMA.

  124944. */

  124945. SQLITE_PRIVATE int sqlite3Reprepare(Vdbe *p){

  124946.   int rc;

  124947.   sqlite3_stmt *pNew;

  124948.   const char *zSql;

  124949.   sqlite3 *db;

  124950.   u8 prepFlags;

  124951. 

  124952.   assert( sqlite3_mutex_held(sqlite3VdbeDb(p)->mutex) );

  124953.   zSql = sqlite3_sql((sqlite3_stmt *)p);

  124954.   assert( zSql!=0 );  /* Reprepare only called for prepare_v2() statements */

  124955.   db = sqlite3VdbeDb(p);

  124956.   assert( sqlite3_mutex_held(db->mutex) );

  124957.   prepFlags = sqlite3VdbePrepareFlags(p);

  124958.   rc = sqlite3LockAndPrepare(db, zSql, -1, prepFlags, p, &pNew, 0);

  124959.   if( rc ){

  124960.     if( rc==SQLITE_NOMEM ){

  124961.       sqlite3OomFault(db);

  124962.     }

  124963.     assert( pNew==0 );

  124964.     return rc;

  124965.   }else{

  124966.     assert( pNew!=0 );

  124967.   }

  124968.   sqlite3VdbeSwap((Vdbe*)pNew, p);

  124969.   sqlite3TransferBindings(pNew, (sqlite3_stmt*)p);

  124970.   sqlite3VdbeResetStepResult((Vdbe*)pNew);

  124971.   sqlite3VdbeFinalize((Vdbe*)pNew);

  124972.   return SQLITE_OK;

  124973. }

  124974. 

  124975. 

  124976. /*

  124977. ** Two versions of the official API.  Legacy and new use.  In the legacy

  124978. ** version, the original SQL text is not saved in the prepared statement

  124979. ** and so if a schema change occurs, SQLITE_SCHEMA is returned by

  124980. ** sqlite3_step().  In the new version, the original SQL text is retained

  124981. ** and the statement is automatically recompiled if an schema change

  124982. ** occurs.

  124983. */

  124984. SQLITE_API int sqlite3_prepare(

  124985.   sqlite3 *db,              /* Database handle. */

  124986.   const char *zSql,         /* UTF-8 encoded SQL statement. */

  124987.   int nBytes,               /* Length of zSql in bytes. */

  124988.   sqlite3_stmt **ppStmt,    /* OUT: A pointer to the prepared statement */

  124989.   const char **pzTail       /* OUT: End of parsed string */

  124990. ){

  124991.   int rc;

  124992.   rc = sqlite3LockAndPrepare(db,zSql,nBytes,0,0,ppStmt,pzTail);

  124993.   assert( rc==SQLITE_OK || ppStmt==0 || *ppStmt==0 );  /* VERIFY: F13021 */

  124994.   return rc;

  124995. }

  124996. SQLITE_API int sqlite3_prepare_v2(

  124997.   sqlite3 *db,              /* Database handle. */

  124998.   const char *zSql,         /* UTF-8 encoded SQL statement. */

  124999.   int nBytes,               /* Length of zSql in bytes. */

  125000.   sqlite3_stmt **ppStmt,    /* OUT: A pointer to the prepared statement */

  125001.   const char **pzTail       /* OUT: End of parsed string */

  125002. ){

  125003.   int rc;

  125004.   /* EVIDENCE-OF: R-37923-12173 The sqlite3_prepare_v2() interface works

  125005.   ** exactly the same as sqlite3_prepare_v3() with a zero prepFlags

  125006.   ** parameter.

  125007.   **

  125008.   ** Proof in that the 5th parameter to sqlite3LockAndPrepare is 0 */

  125009.   rc = sqlite3LockAndPrepare(db,zSql,nBytes,SQLITE_PREPARE_SAVESQL,0,

  125010.                              ppStmt,pzTail);

  125011.   assert( rc==SQLITE_OK || ppStmt==0 || *ppStmt==0 );

  125012.   return rc;

  125013. }

  125014. SQLITE_API int sqlite3_prepare_v3(

  125015.   sqlite3 *db,              /* Database handle. */

  125016.   const char *zSql,         /* UTF-8 encoded SQL statement. */

  125017.   int nBytes,               /* Length of zSql in bytes. */

  125018.   unsigned int prepFlags,   /* Zero or more SQLITE_PREPARE_* flags */

  125019.   sqlite3_stmt **ppStmt,    /* OUT: A pointer to the prepared statement */

  125020.   const char **pzTail       /* OUT: End of parsed string */

  125021. ){

  125022.   int rc;

  125023.   /* EVIDENCE-OF: R-56861-42673 sqlite3_prepare_v3() differs from

  125024.   ** sqlite3_prepare_v2() only in having the extra prepFlags parameter,

  125025.   ** which is a bit array consisting of zero or more of the

  125026.   ** SQLITE_PREPARE_* flags.

  125027.   **

  125028.   ** Proof by comparison to the implementation of sqlite3_prepare_v2()

  125029.   ** directly above. */

  125030.   rc = sqlite3LockAndPrepare(db,zSql,nBytes,

  125031.                  SQLITE_PREPARE_SAVESQL|(prepFlags&SQLITE_PREPARE_MASK),

  125032.                  0,ppStmt,pzTail);

  125033.   assert( rc==SQLITE_OK || ppStmt==0 || *ppStmt==0 );

  125034.   return rc;

  125035. }

  125036. 

  125037. 

  125038. #ifndef SQLITE_OMIT_UTF16

  125039. /*

  125040. ** Compile the UTF-16 encoded SQL statement zSql into a statement handle.

  125041. */

  125042. static int sqlite3Prepare16(

  125043.   sqlite3 *db,              /* Database handle. */ 

  125044.   const void *zSql,         /* UTF-16 encoded SQL statement. */

  125045.   int nBytes,               /* Length of zSql in bytes. */

  125046.   u32 prepFlags,            /* Zero or more SQLITE_PREPARE_* flags */

  125047.   sqlite3_stmt **ppStmt,    /* OUT: A pointer to the prepared statement */

  125048.   const void **pzTail       /* OUT: End of parsed string */

  125049. ){

  125050.   /* This function currently works by first transforming the UTF-16

  125051.   ** encoded string to UTF-8, then invoking sqlite3_prepare(). The

  125052.   ** tricky bit is figuring out the pointer to return in *pzTail.

  125053.   */

  125054.   char *zSql8;

  125055.   const char *zTail8 = 0;

  125056.   int rc = SQLITE_OK;

  125057. 

  125058. #ifdef SQLITE_ENABLE_API_ARMOR

  125059.   if( ppStmt==0 ) return SQLITE_MISUSE_BKPT;

  125060. #endif

  125061.   *ppStmt = 0;

  125062.   if( !sqlite3SafetyCheckOk(db)||zSql==0 ){

  125063.     return SQLITE_MISUSE_BKPT;

  125064.   }

  125065.   if( nBytes>=0 ){

  125066.     int sz;

  125067.     const char *z = (const char*)zSql;

  125068.     for(sz=0; sz<nBytes && (z[sz]!=0 || z[sz+1]!=0); sz += 2){}

  125069.     nBytes = sz;

  125070.   }

  125071.   sqlite3_mutex_enter(db->mutex);

  125072.   zSql8 = sqlite3Utf16to8(db, zSql, nBytes, SQLITE_UTF16NATIVE);

  125073.   if( zSql8 ){

  125074.     rc = sqlite3LockAndPrepare(db, zSql8, -1, prepFlags, 0, ppStmt, &zTail8);

  125075.   }

  125076. 

  125077.   if( zTail8 && pzTail ){

  125078.     /* If sqlite3_prepare returns a tail pointer, we calculate the

  125079.     ** equivalent pointer into the UTF-16 string by counting the unicode

  125080.     ** characters between zSql8 and zTail8, and then returning a pointer

  125081.     ** the same number of characters into the UTF-16 string.

  125082.     */

  125083.     int chars_parsed = sqlite3Utf8CharLen(zSql8, (int)(zTail8-zSql8));

  125084.     *pzTail = (u8 *)zSql + sqlite3Utf16ByteLen(zSql, chars_parsed);

  125085.   }

  125086.   sqlite3DbFree(db, zSql8); 

  125087.   rc = sqlite3ApiExit(db, rc);

  125088.   sqlite3_mutex_leave(db->mutex);

  125089.   return rc;

  125090. }

  125091. 

  125092. /*

  125093. ** Two versions of the official API.  Legacy and new use.  In the legacy

  125094. ** version, the original SQL text is not saved in the prepared statement

  125095. ** and so if a schema change occurs, SQLITE_SCHEMA is returned by

  125096. ** sqlite3_step().  In the new version, the original SQL text is retained

  125097. ** and the statement is automatically recompiled if an schema change

  125098. ** occurs.

  125099. */

  125100. SQLITE_API int sqlite3_prepare16(

  125101.   sqlite3 *db,              /* Database handle. */ 

  125102.   const void *zSql,         /* UTF-16 encoded SQL statement. */

  125103.   int nBytes,               /* Length of zSql in bytes. */

  125104.   sqlite3_stmt **ppStmt,    /* OUT: A pointer to the prepared statement */

  125105.   const void **pzTail       /* OUT: End of parsed string */

  125106. ){

  125107.   int rc;

  125108.   rc = sqlite3Prepare16(db,zSql,nBytes,0,ppStmt,pzTail);

  125109.   assert( rc==SQLITE_OK || ppStmt==0 || *ppStmt==0 );  /* VERIFY: F13021 */

  125110.   return rc;

  125111. }

  125112. SQLITE_API int sqlite3_prepare16_v2(

  125113.   sqlite3 *db,              /* Database handle. */ 

  125114.   const void *zSql,         /* UTF-16 encoded SQL statement. */

  125115.   int nBytes,               /* Length of zSql in bytes. */

  125116.   sqlite3_stmt **ppStmt,    /* OUT: A pointer to the prepared statement */

  125117.   const void **pzTail       /* OUT: End of parsed string */

  125118. ){

  125119.   int rc;

  125120.   rc = sqlite3Prepare16(db,zSql,nBytes,SQLITE_PREPARE_SAVESQL,ppStmt,pzTail);

  125121.   assert( rc==SQLITE_OK || ppStmt==0 || *ppStmt==0 );  /* VERIFY: F13021 */

  125122.   return rc;

  125123. }

  125124. SQLITE_API int sqlite3_prepare16_v3(

  125125.   sqlite3 *db,              /* Database handle. */ 

  125126.   const void *zSql,         /* UTF-16 encoded SQL statement. */

  125127.   int nBytes,               /* Length of zSql in bytes. */

  125128.   unsigned int prepFlags,   /* Zero or more SQLITE_PREPARE_* flags */

  125129.   sqlite3_stmt **ppStmt,    /* OUT: A pointer to the prepared statement */

  125130.   const void **pzTail       /* OUT: End of parsed string */

  125131. ){

  125132.   int rc;

  125133.   rc = sqlite3Prepare16(db,zSql,nBytes,

  125134.          SQLITE_PREPARE_SAVESQL|(prepFlags&SQLITE_PREPARE_MASK),

  125135.          ppStmt,pzTail);

  125136.   assert( rc==SQLITE_OK || ppStmt==0 || *ppStmt==0 );  /* VERIFY: F13021 */

  125137.   return rc;

  125138. }

  125139. 

  125140. #endif /* SQLITE_OMIT_UTF16 */

  125141. 

  125142. /************** End of prepare.c *********************************************/

  125143. /************** Begin file select.c ******************************************/

  125144. /*

  125145. ** 2001 September 15

  125146. **

  125147. ** The author disclaims copyright to this source code.  In place of

  125148. ** a legal notice, here is a blessing:

  125149. **

  125150. **    May you do good and not evil.

  125151. **    May you find forgiveness for yourself and forgive others.

  125152. **    May you share freely, never taking more than you give.

  125153. **

  125154. *************************************************************************

  125155. ** This file contains C code routines that are called by the parser

  125156. ** to handle SELECT statements in SQLite.

  125157. */

  125158. /* #include "sqliteInt.h" */

  125159. 

  125160. /*

  125161. ** Trace output macros

  125162. */

  125163. #if SELECTTRACE_ENABLED

  125164. /***/ int sqlite3SelectTrace = 0;

  125165. # define SELECTTRACE(K,P,S,X)  \

  125166.   if(sqlite3SelectTrace&(K))   \

  125167.     sqlite3DebugPrintf("%u/%d/%p: ",(S)->selId,(P)->addrExplain,(S)),\

  125168.     sqlite3DebugPrintf X

  125169. #else

  125170. # define SELECTTRACE(K,P,S,X)

  125171. #endif

  125172. 

  125173. 

  125174. /*

  125175. ** An instance of the following object is used to record information about

  125176. ** how to process the DISTINCT keyword, to simplify passing that information

  125177. ** into the selectInnerLoop() routine.

  125178. */

  125179. typedef struct DistinctCtx DistinctCtx;

  125180. struct DistinctCtx {

  125181.   u8 isTnct;      /* True if the DISTINCT keyword is present */

  125182.   u8 eTnctType;   /* One of the WHERE_DISTINCT_* operators */

  125183.   int tabTnct;    /* Ephemeral table used for DISTINCT processing */

  125184.   int addrTnct;   /* Address of OP_OpenEphemeral opcode for tabTnct */

  125185. };

  125186. 

  125187. /*

  125188. ** An instance of the following object is used to record information about

  125189. ** the ORDER BY (or GROUP BY) clause of query is being coded.

  125190. **

  125191. ** The aDefer[] array is used by the sorter-references optimization. For

  125192. ** example, assuming there is no index that can be used for the ORDER BY,

  125193. ** for the query:

  125194. **

  125195. **     SELECT a, bigblob FROM t1 ORDER BY a LIMIT 10;

  125196. **

  125197. ** it may be more efficient to add just the "a" values to the sorter, and

  125198. ** retrieve the associated "bigblob" values directly from table t1 as the

  125199. ** 10 smallest "a" values are extracted from the sorter.

  125200. **

  125201. ** When the sorter-reference optimization is used, there is one entry in the

  125202. ** aDefer[] array for each database table that may be read as values are

  125203. ** extracted from the sorter.

  125204. */

  125205. typedef struct SortCtx SortCtx;

  125206. struct SortCtx {

  125207.   ExprList *pOrderBy;   /* The ORDER BY (or GROUP BY clause) */

  125208.   int nOBSat;           /* Number of ORDER BY terms satisfied by indices */

  125209.   int iECursor;         /* Cursor number for the sorter */

  125210.   int regReturn;        /* Register holding block-output return address */

  125211.   int labelBkOut;       /* Start label for the block-output subroutine */

  125212.   int addrSortIndex;    /* Address of the OP_SorterOpen or OP_OpenEphemeral */

  125213.   int labelDone;        /* Jump here when done, ex: LIMIT reached */

  125214.   int labelOBLopt;      /* Jump here when sorter is full */

  125215.   u8 sortFlags;         /* Zero or more SORTFLAG_* bits */

  125216. #ifdef SQLITE_ENABLE_SORTER_REFERENCES

  125217.   u8 nDefer;            /* Number of valid entries in aDefer[] */

  125218.   struct DeferredCsr {

  125219.     Table *pTab;        /* Table definition */

  125220.     int iCsr;           /* Cursor number for table */

  125221.     int nKey;           /* Number of PK columns for table pTab (>=1) */

  125222.   } aDefer[4];

  125223. #endif

  125224.   struct RowLoadInfo *pDeferredRowLoad;  /* Deferred row loading info or NULL */

  125225. };

  125226. #define SORTFLAG_UseSorter  0x01   /* Use SorterOpen instead of OpenEphemeral */

  125227. 

  125228. /*

  125229. ** Delete all the content of a Select structure.  Deallocate the structure

  125230. ** itself only if bFree is true.

  125231. */

  125232. static void clearSelect(sqlite3 *db, Select *p, int bFree){

  125233.   while( p ){

  125234.     Select *pPrior = p->pPrior;

  125235.     sqlite3ExprListDelete(db, p->pEList);

  125236.     sqlite3SrcListDelete(db, p->pSrc);

  125237.     sqlite3ExprDelete(db, p->pWhere);

  125238.     sqlite3ExprListDelete(db, p->pGroupBy);

  125239.     sqlite3ExprDelete(db, p->pHaving);

  125240.     sqlite3ExprListDelete(db, p->pOrderBy);

  125241.     sqlite3ExprDelete(db, p->pLimit);

  125242. #ifndef SQLITE_OMIT_WINDOWFUNC

  125243.     if( OK_IF_ALWAYS_TRUE(p->pWinDefn) ){

  125244.       sqlite3WindowListDelete(db, p->pWinDefn);

  125245.     }

  125246. #endif

  125247.     if( OK_IF_ALWAYS_TRUE(p->pWith) ) sqlite3WithDelete(db, p->pWith);

  125248.     if( bFree ) sqlite3DbFreeNN(db, p);

  125249.     p = pPrior;

  125250.     bFree = 1;

  125251.   }

  125252. }

  125253. 

  125254. /*

  125255. ** Initialize a SelectDest structure.

  125256. */

  125257. SQLITE_PRIVATE void sqlite3SelectDestInit(SelectDest *pDest, int eDest, int iParm){

  125258.   pDest->eDest = (u8)eDest;

  125259.   pDest->iSDParm = iParm;

  125260.   pDest->zAffSdst = 0;

  125261.   pDest->iSdst = 0;

  125262.   pDest->nSdst = 0;

  125263. }

  125264. 

  125265. 

  125266. /*

  125267. ** Allocate a new Select structure and return a pointer to that

  125268. ** structure.

  125269. */

  125270. SQLITE_PRIVATE Select *sqlite3SelectNew(

  125271.   Parse *pParse,        /* Parsing context */

  125272.   ExprList *pEList,     /* which columns to include in the result */

  125273.   SrcList *pSrc,        /* the FROM clause -- which tables to scan */

  125274.   Expr *pWhere,         /* the WHERE clause */

  125275.   ExprList *pGroupBy,   /* the GROUP BY clause */

  125276.   Expr *pHaving,        /* the HAVING clause */

  125277.   ExprList *pOrderBy,   /* the ORDER BY clause */

  125278.   u32 selFlags,         /* Flag parameters, such as SF_Distinct */

  125279.   Expr *pLimit          /* LIMIT value.  NULL means not used */

  125280. ){

  125281.   Select *pNew;

  125282.   Select standin;

  125283.   pNew = sqlite3DbMallocRawNN(pParse->db, sizeof(*pNew) );

  125284.   if( pNew==0 ){

  125285.     assert( pParse->db->mallocFailed );

  125286.     pNew = &standin;

  125287.   }

  125288.   if( pEList==0 ){

  125289.     pEList = sqlite3ExprListAppend(pParse, 0,

  125290.                                    sqlite3Expr(pParse->db,TK_ASTERISK,0));

  125291.   }

  125292.   pNew->pEList = pEList;

  125293.   pNew->op = TK_SELECT;

  125294.   pNew->selFlags = selFlags;

  125295.   pNew->iLimit = 0;

  125296.   pNew->iOffset = 0;

  125297.   pNew->selId = ++pParse->nSelect;

  125298.   pNew->addrOpenEphm[0] = -1;

  125299.   pNew->addrOpenEphm[1] = -1;

  125300.   pNew->nSelectRow = 0;

  125301.   if( pSrc==0 ) pSrc = sqlite3DbMallocZero(pParse->db, sizeof(*pSrc));

  125302.   pNew->pSrc = pSrc;

  125303.   pNew->pWhere = pWhere;

  125304.   pNew->pGroupBy = pGroupBy;

  125305.   pNew->pHaving = pHaving;

  125306.   pNew->pOrderBy = pOrderBy;

  125307.   pNew->pPrior = 0;

  125308.   pNew->pNext = 0;

  125309.   pNew->pLimit = pLimit;

  125310.   pNew->pWith = 0;

  125311. #ifndef SQLITE_OMIT_WINDOWFUNC

  125312.   pNew->pWin = 0;

  125313.   pNew->pWinDefn = 0;

  125314. #endif

  125315.   if( pParse->db->mallocFailed ) {

  125316.     clearSelect(pParse->db, pNew, pNew!=&standin);

  125317.     pNew = 0;

  125318.   }else{

  125319.     assert( pNew->pSrc!=0 || pParse->nErr>0 );

  125320.   }

  125321.   assert( pNew!=&standin );

  125322.   return pNew;

  125323. }

  125324. 

  125325. 

  125326. /*

  125327. ** Delete the given Select structure and all of its substructures.

  125328. */

  125329. SQLITE_PRIVATE void sqlite3SelectDelete(sqlite3 *db, Select *p){

  125330.   if( OK_IF_ALWAYS_TRUE(p) ) clearSelect(db, p, 1);

  125331. }

  125332. 

  125333. /*

  125334. ** Return a pointer to the right-most SELECT statement in a compound.

  125335. */

  125336. static Select *findRightmost(Select *p){

  125337.   while( p->pNext ) p = p->pNext;

  125338.   return p;

  125339. }

  125340. 

  125341. /*

  125342. ** Given 1 to 3 identifiers preceding the JOIN keyword, determine the

  125343. ** type of join.  Return an integer constant that expresses that type

  125344. ** in terms of the following bit values:

  125345. **

  125346. **     JT_INNER

  125347. **     JT_CROSS

  125348. **     JT_OUTER

  125349. **     JT_NATURAL

  125350. **     JT_LEFT

  125351. **     JT_RIGHT

  125352. **

  125353. ** A full outer join is the combination of JT_LEFT and JT_RIGHT.

  125354. **

  125355. ** If an illegal or unsupported join type is seen, then still return

  125356. ** a join type, but put an error in the pParse structure.

  125357. */

  125358. SQLITE_PRIVATE int sqlite3JoinType(Parse *pParse, Token *pA, Token *pB, Token *pC){

  125359.   int jointype = 0;

  125360.   Token *apAll[3];

  125361.   Token *p;

  125362.                              /*   0123456789 123456789 123456789 123 */

  125363.   static const char zKeyText[] = "naturaleftouterightfullinnercross";

  125364.   static const struct {

  125365.     u8 i;        /* Beginning of keyword text in zKeyText[] */

  125366.     u8 nChar;    /* Length of the keyword in characters */

  125367.     u8 code;     /* Join type mask */

  125368.   } aKeyword[] = {

  125369.     /* natural */ { 0,  7, JT_NATURAL                },

  125370.     /* left    */ { 6,  4, JT_LEFT|JT_OUTER          },

  125371.     /* outer   */ { 10, 5, JT_OUTER                  },

  125372.     /* right   */ { 14, 5, JT_RIGHT|JT_OUTER         },

  125373.     /* full    */ { 19, 4, JT_LEFT|JT_RIGHT|JT_OUTER },

  125374.     /* inner   */ { 23, 5, JT_INNER                  },

  125375.     /* cross   */ { 28, 5, JT_INNER|JT_CROSS         },

  125376.   };

  125377.   int i, j;

  125378.   apAll[0] = pA;

  125379.   apAll[1] = pB;

  125380.   apAll[2] = pC;

  125381.   for(i=0; i<3 && apAll[i]; i++){

  125382.     p = apAll[i];

  125383.     for(j=0; j<ArraySize(aKeyword); j++){

  125384.       if( p->n==aKeyword[j].nChar 

  125385.           && sqlite3StrNICmp((char*)p->z, &zKeyText[aKeyword[j].i], p->n)==0 ){

  125386.         jointype |= aKeyword[j].code;

  125387.         break;

  125388.       }

  125389.     }

  125390.     testcase( j==0 || j==1 || j==2 || j==3 || j==4 || j==5 || j==6 );

  125391.     if( j>=ArraySize(aKeyword) ){

  125392.       jointype |= JT_ERROR;

  125393.       break;

  125394.     }

  125395.   }

  125396.   if(

  125397.      (jointype & (JT_INNER|JT_OUTER))==(JT_INNER|JT_OUTER) ||

  125398.      (jointype & JT_ERROR)!=0

  125399.   ){

  125400.     const char *zSp = " ";

  125401.     assert( pB!=0 );

  125402.     if( pC==0 ){ zSp++; }

  125403.     sqlite3ErrorMsg(pParse, "unknown or unsupported join type: "

  125404.        "%T %T%s%T", pA, pB, zSp, pC);

  125405.     jointype = JT_INNER;

  125406.   }else if( (jointype & JT_OUTER)!=0 

  125407.          && (jointype & (JT_LEFT|JT_RIGHT))!=JT_LEFT ){

  125408.     sqlite3ErrorMsg(pParse, 

  125409.       "RIGHT and FULL OUTER JOINs are not currently supported");

  125410.     jointype = JT_INNER;

  125411.   }

  125412.   return jointype;

  125413. }

  125414. 

  125415. /*

  125416. ** Return the index of a column in a table.  Return -1 if the column

  125417. ** is not contained in the table.

  125418. */

  125419. static int columnIndex(Table *pTab, const char *zCol){

  125420.   int i;

  125421.   for(i=0; i<pTab->nCol; i++){

  125422.     if( sqlite3StrICmp(pTab->aCol[i].zName, zCol)==0 ) return i;

  125423.   }

  125424.   return -1;

  125425. }

  125426. 

  125427. /*

  125428. ** Search the first N tables in pSrc, from left to right, looking for a

  125429. ** table that has a column named zCol.  

  125430. **

  125431. ** When found, set *piTab and *piCol to the table index and column index

  125432. ** of the matching column and return TRUE.

  125433. **

  125434. ** If not found, return FALSE.

  125435. */

  125436. static int tableAndColumnIndex(

  125437.   SrcList *pSrc,       /* Array of tables to search */

  125438.   int N,               /* Number of tables in pSrc->a[] to search */

  125439.   const char *zCol,    /* Name of the column we are looking for */

  125440.   int *piTab,          /* Write index of pSrc->a[] here */

  125441.   int *piCol           /* Write index of pSrc->a[*piTab].pTab->aCol[] here */

  125442. ){

  125443.   int i;               /* For looping over tables in pSrc */

  125444.   int iCol;            /* Index of column matching zCol */

  125445. 

  125446.   assert( (piTab==0)==(piCol==0) );  /* Both or neither are NULL */

  125447.   for(i=0; i<N; i++){

  125448.     iCol = columnIndex(pSrc->a[i].pTab, zCol);

  125449.     if( iCol>=0 ){

  125450.       if( piTab ){

  125451.         *piTab = i;

  125452.         *piCol = iCol;

  125453.       }

  125454.       return 1;

  125455.     }

  125456.   }

  125457.   return 0;

  125458. }

  125459. 

  125460. /*

  125461. ** This function is used to add terms implied by JOIN syntax to the

  125462. ** WHERE clause expression of a SELECT statement. The new term, which

  125463. ** is ANDed with the existing WHERE clause, is of the form:

  125464. **

  125465. **    (tab1.col1 = tab2.col2)

  125466. **

  125467. ** where tab1 is the iSrc'th table in SrcList pSrc and tab2 is the 

  125468. ** (iSrc+1)'th. Column col1 is column iColLeft of tab1, and col2 is

  125469. ** column iColRight of tab2.

  125470. */

  125471. static void addWhereTerm(

  125472.   Parse *pParse,                  /* Parsing context */

  125473.   SrcList *pSrc,                  /* List of tables in FROM clause */

  125474.   int iLeft,                      /* Index of first table to join in pSrc */

  125475.   int iColLeft,                   /* Index of column in first table */

  125476.   int iRight,                     /* Index of second table in pSrc */

  125477.   int iColRight,                  /* Index of column in second table */

  125478.   int isOuterJoin,                /* True if this is an OUTER join */

  125479.   Expr **ppWhere                  /* IN/OUT: The WHERE clause to add to */

  125480. ){

  125481.   sqlite3 *db = pParse->db;

  125482.   Expr *pE1;

  125483.   Expr *pE2;

  125484.   Expr *pEq;

  125485. 

  125486.   assert( iLeft<iRight );

  125487.   assert( pSrc->nSrc>iRight );

  125488.   assert( pSrc->a[iLeft].pTab );

  125489.   assert( pSrc->a[iRight].pTab );

  125490. 

  125491.   pE1 = sqlite3CreateColumnExpr(db, pSrc, iLeft, iColLeft);

  125492.   pE2 = sqlite3CreateColumnExpr(db, pSrc, iRight, iColRight);

  125493. 

  125494.   pEq = sqlite3PExpr(pParse, TK_EQ, pE1, pE2);

  125495.   if( pEq && isOuterJoin ){

  125496.     ExprSetProperty(pEq, EP_FromJoin);

  125497.     assert( !ExprHasProperty(pEq, EP_TokenOnly|EP_Reduced) );

  125498.     ExprSetVVAProperty(pEq, EP_NoReduce);

  125499.     pEq->iRightJoinTable = (i16)pE2->iTable;

  125500.   }

  125501.   *ppWhere = sqlite3ExprAnd(pParse, *ppWhere, pEq);

  125502. }

  125503. 

  125504. /*

  125505. ** Set the EP_FromJoin property on all terms of the given expression.

  125506. ** And set the Expr.iRightJoinTable to iTable for every term in the

  125507. ** expression.

  125508. **

  125509. ** The EP_FromJoin property is used on terms of an expression to tell

  125510. ** the LEFT OUTER JOIN processing logic that this term is part of the

  125511. ** join restriction specified in the ON or USING clause and not a part

  125512. ** of the more general WHERE clause.  These terms are moved over to the

  125513. ** WHERE clause during join processing but we need to remember that they

  125514. ** originated in the ON or USING clause.

  125515. **

  125516. ** The Expr.iRightJoinTable tells the WHERE clause processing that the

  125517. ** expression depends on table iRightJoinTable even if that table is not

  125518. ** explicitly mentioned in the expression.  That information is needed

  125519. ** for cases like this:

  125520. **

  125521. **    SELECT * FROM t1 LEFT JOIN t2 ON t1.a=t2.b AND t1.x=5

  125522. **

  125523. ** The where clause needs to defer the handling of the t1.x=5

  125524. ** term until after the t2 loop of the join.  In that way, a

  125525. ** NULL t2 row will be inserted whenever t1.x!=5.  If we do not

  125526. ** defer the handling of t1.x=5, it will be processed immediately

  125527. ** after the t1 loop and rows with t1.x!=5 will never appear in

  125528. ** the output, which is incorrect.

  125529. */

  125530. static void setJoinExpr(Expr *p, int iTable){

  125531.   while( p ){

  125532.     ExprSetProperty(p, EP_FromJoin);

  125533.     assert( !ExprHasProperty(p, EP_TokenOnly|EP_Reduced) );

  125534.     ExprSetVVAProperty(p, EP_NoReduce);

  125535.     p->iRightJoinTable = (i16)iTable;

  125536.     if( p->op==TK_FUNCTION && p->x.pList ){

  125537.       int i;

  125538.       for(i=0; i<p->x.pList->nExpr; i++){

  125539.         setJoinExpr(p->x.pList->a[i].pExpr, iTable);

  125540.       }

  125541.     }

  125542.     setJoinExpr(p->pLeft, iTable);

  125543.     p = p->pRight;

  125544.   } 

  125545. }

  125546. 

  125547. /* Undo the work of setJoinExpr().  In the expression tree p, convert every

  125548. ** term that is marked with EP_FromJoin and iRightJoinTable==iTable into

  125549. ** an ordinary term that omits the EP_FromJoin mark.

  125550. **

  125551. ** This happens when a LEFT JOIN is simplified into an ordinary JOIN.

  125552. */

  125553. static void unsetJoinExpr(Expr *p, int iTable){

  125554.   while( p ){

  125555.     if( ExprHasProperty(p, EP_FromJoin)

  125556.      && (iTable<0 || p->iRightJoinTable==iTable) ){

  125557.       ExprClearProperty(p, EP_FromJoin);

  125558.     }

  125559.     if( p->op==TK_FUNCTION && p->x.pList ){

  125560.       int i;

  125561.       for(i=0; i<p->x.pList->nExpr; i++){

  125562.         unsetJoinExpr(p->x.pList->a[i].pExpr, iTable);

  125563.       }

  125564.     }

  125565.     unsetJoinExpr(p->pLeft, iTable);

  125566.     p = p->pRight;

  125567.   } 

  125568. }

  125569. 

  125570. /*

  125571. ** This routine processes the join information for a SELECT statement.

  125572. ** ON and USING clauses are converted into extra terms of the WHERE clause.

  125573. ** NATURAL joins also create extra WHERE clause terms.

  125574. **

  125575. ** The terms of a FROM clause are contained in the Select.pSrc structure.

  125576. ** The left most table is the first entry in Select.pSrc.  The right-most

  125577. ** table is the last entry.  The join operator is held in the entry to

  125578. ** the left.  Thus entry 0 contains the join operator for the join between

  125579. ** entries 0 and 1.  Any ON or USING clauses associated with the join are

  125580. ** also attached to the left entry.

  125581. **

  125582. ** This routine returns the number of errors encountered.

  125583. */

  125584. static int sqliteProcessJoin(Parse *pParse, Select *p){

  125585.   SrcList *pSrc;                  /* All tables in the FROM clause */

  125586.   int i, j;                       /* Loop counters */

  125587.   struct SrcList_item *pLeft;     /* Left table being joined */

  125588.   struct SrcList_item *pRight;    /* Right table being joined */

  125589. 

  125590.   pSrc = p->pSrc;

  125591.   pLeft = &pSrc->a[0];

  125592.   pRight = &pLeft[1];

  125593.   for(i=0; i<pSrc->nSrc-1; i++, pRight++, pLeft++){

  125594.     Table *pRightTab = pRight->pTab;

  125595.     int isOuter;

  125596. 

  125597.     if( NEVER(pLeft->pTab==0 || pRightTab==0) ) continue;

  125598.     isOuter = (pRight->fg.jointype & JT_OUTER)!=0;

  125599. 

  125600.     /* When the NATURAL keyword is present, add WHERE clause terms for

  125601.     ** every column that the two tables have in common.

  125602.     */

  125603.     if( pRight->fg.jointype & JT_NATURAL ){

  125604.       if( pRight->pOn || pRight->pUsing ){

  125605.         sqlite3ErrorMsg(pParse, "a NATURAL join may not have "

  125606.            "an ON or USING clause", 0);

  125607.         return 1;

  125608.       }

  125609.       for(j=0; j<pRightTab->nCol; j++){

  125610.         char *zName;   /* Name of column in the right table */

  125611.         int iLeft;     /* Matching left table */

  125612.         int iLeftCol;  /* Matching column in the left table */

  125613. 

  125614.         zName = pRightTab->aCol[j].zName;

  125615.         if( tableAndColumnIndex(pSrc, i+1, zName, &iLeft, &iLeftCol) ){

  125616.           addWhereTerm(pParse, pSrc, iLeft, iLeftCol, i+1, j,

  125617.                        isOuter, &p->pWhere);

  125618.         }

  125619.       }

  125620.     }

  125621. 

  125622.     /* Disallow both ON and USING clauses in the same join

  125623.     */

  125624.     if( pRight->pOn && pRight->pUsing ){

  125625.       sqlite3ErrorMsg(pParse, "cannot have both ON and USING "

  125626.         "clauses in the same join");

  125627.       return 1;

  125628.     }

  125629. 

  125630.     /* Add the ON clause to the end of the WHERE clause, connected by

  125631.     ** an AND operator.

  125632.     */

  125633.     if( pRight->pOn ){

  125634.       if( isOuter ) setJoinExpr(pRight->pOn, pRight->iCursor);

  125635.       p->pWhere = sqlite3ExprAnd(pParse, p->pWhere, pRight->pOn);

  125636.       pRight->pOn = 0;

  125637.     }

  125638. 

  125639.     /* Create extra terms on the WHERE clause for each column named

  125640.     ** in the USING clause.  Example: If the two tables to be joined are 

  125641.     ** A and B and the USING clause names X, Y, and Z, then add this

  125642.     ** to the WHERE clause:    A.X=B.X AND A.Y=B.Y AND A.Z=B.Z

  125643.     ** Report an error if any column mentioned in the USING clause is

  125644.     ** not contained in both tables to be joined.

  125645.     */

  125646.     if( pRight->pUsing ){

  125647.       IdList *pList = pRight->pUsing;

  125648.       for(j=0; j<pList->nId; j++){

  125649.         char *zName;     /* Name of the term in the USING clause */

  125650.         int iLeft;       /* Table on the left with matching column name */

  125651.         int iLeftCol;    /* Column number of matching column on the left */

  125652.         int iRightCol;   /* Column number of matching column on the right */

  125653. 

  125654.         zName = pList->a[j].zName;

  125655.         iRightCol = columnIndex(pRightTab, zName);

  125656.         if( iRightCol<0

  125657.          || !tableAndColumnIndex(pSrc, i+1, zName, &iLeft, &iLeftCol)

  125658.         ){

  125659.           sqlite3ErrorMsg(pParse, "cannot join using column %s - column "

  125660.             "not present in both tables", zName);

  125661.           return 1;

  125662.         }

  125663.         addWhereTerm(pParse, pSrc, iLeft, iLeftCol, i+1, iRightCol,

  125664.                      isOuter, &p->pWhere);

  125665.       }

  125666.     }

  125667.   }

  125668.   return 0;

  125669. }

  125670. 

  125671. /*

  125672. ** An instance of this object holds information (beyond pParse and pSelect)

  125673. ** needed to load the next result row that is to be added to the sorter.

  125674. */

  125675. typedef struct RowLoadInfo RowLoadInfo;

  125676. struct RowLoadInfo {

  125677.   int regResult;               /* Store results in array of registers here */

  125678.   u8 ecelFlags;                /* Flag argument to ExprCodeExprList() */

  125679. #ifdef SQLITE_ENABLE_SORTER_REFERENCES

  125680.   ExprList *pExtra;            /* Extra columns needed by sorter refs */

  125681.   int regExtraResult;          /* Where to load the extra columns */

  125682. #endif

  125683. };

  125684. 

  125685. /*

  125686. ** This routine does the work of loading query data into an array of

  125687. ** registers so that it can be added to the sorter.

  125688. */

  125689. static void innerLoopLoadRow(

  125690.   Parse *pParse,             /* Statement under construction */

  125691.   Select *pSelect,           /* The query being coded */

  125692.   RowLoadInfo *pInfo         /* Info needed to complete the row load */

  125693. ){

  125694.   sqlite3ExprCodeExprList(pParse, pSelect->pEList, pInfo->regResult,

  125695.                           0, pInfo->ecelFlags);

  125696. #ifdef SQLITE_ENABLE_SORTER_REFERENCES

  125697.   if( pInfo->pExtra ){

  125698.     sqlite3ExprCodeExprList(pParse, pInfo->pExtra, pInfo->regExtraResult, 0, 0);

  125699.     sqlite3ExprListDelete(pParse->db, pInfo->pExtra);

  125700.   }

  125701. #endif

  125702. }

  125703. 

  125704. /*

  125705. ** Code the OP_MakeRecord instruction that generates the entry to be

  125706. ** added into the sorter.

  125707. **

  125708. ** Return the register in which the result is stored.

  125709. */

  125710. static int makeSorterRecord(

  125711.   Parse *pParse,

  125712.   SortCtx *pSort,

  125713.   Select *pSelect,

  125714.   int regBase,

  125715.   int nBase

  125716. ){

  125717.   int nOBSat = pSort->nOBSat;

  125718.   Vdbe *v = pParse->pVdbe;

  125719.   int regOut = ++pParse->nMem;

  125720.   if( pSort->pDeferredRowLoad ){

  125721.     innerLoopLoadRow(pParse, pSelect, pSort->pDeferredRowLoad);

  125722.   }

  125723.   sqlite3VdbeAddOp3(v, OP_MakeRecord, regBase+nOBSat, nBase-nOBSat, regOut);

  125724.   return regOut;

  125725. }

  125726. 

  125727. /*

  125728. ** Generate code that will push the record in registers regData

  125729. ** through regData+nData-1 onto the sorter.

  125730. */

  125731. static void pushOntoSorter(

  125732.   Parse *pParse,         /* Parser context */

  125733.   SortCtx *pSort,        /* Information about the ORDER BY clause */

  125734.   Select *pSelect,       /* The whole SELECT statement */

  125735.   int regData,           /* First register holding data to be sorted */

  125736.   int regOrigData,       /* First register holding data before packing */

  125737.   int nData,             /* Number of elements in the regData data array */

  125738.   int nPrefixReg         /* No. of reg prior to regData available for use */

  125739. ){

  125740.   Vdbe *v = pParse->pVdbe;                         /* Stmt under construction */

  125741.   int bSeq = ((pSort->sortFlags & SORTFLAG_UseSorter)==0);

  125742.   int nExpr = pSort->pOrderBy->nExpr;              /* No. of ORDER BY terms */

  125743.   int nBase = nExpr + bSeq + nData;                /* Fields in sorter record */

  125744.   int regBase;                                     /* Regs for sorter record */

  125745.   int regRecord = 0;                               /* Assembled sorter record */

  125746.   int nOBSat = pSort->nOBSat;                      /* ORDER BY terms to skip */

  125747.   int op;                            /* Opcode to add sorter record to sorter */

  125748.   int iLimit;                        /* LIMIT counter */

  125749.   int iSkip = 0;                     /* End of the sorter insert loop */

  125750. 

  125751.   assert( bSeq==0 || bSeq==1 );

  125752. 

  125753.   /* Three cases:

  125754.   **   (1) The data to be sorted has already been packed into a Record

  125755.   **       by a prior OP_MakeRecord.  In this case nData==1 and regData

  125756.   **       will be completely unrelated to regOrigData.

  125757.   **   (2) All output columns are included in the sort record.  In that

  125758.   **       case regData==regOrigData.

  125759.   **   (3) Some output columns are omitted from the sort record due to

  125760.   **       the SQLITE_ENABLE_SORTER_REFERENCE optimization, or due to the

  125761.   **       SQLITE_ECEL_OMITREF optimization, or due to the 

  125762.   **       SortCtx.pDeferredRowLoad optimiation.  In any of these cases

  125763.   **       regOrigData is 0 to prevent this routine from trying to copy

  125764.   **       values that might not yet exist.

  125765.   */

  125766.   assert( nData==1 || regData==regOrigData || regOrigData==0 );

  125767. 

  125768.   if( nPrefixReg ){

  125769.     assert( nPrefixReg==nExpr+bSeq );

  125770.     regBase = regData - nPrefixReg;

  125771.   }else{

  125772.     regBase = pParse->nMem + 1;

  125773.     pParse->nMem += nBase;

  125774.   }

  125775.   assert( pSelect->iOffset==0 || pSelect->iLimit!=0 );

  125776.   iLimit = pSelect->iOffset ? pSelect->iOffset+1 : pSelect->iLimit;

  125777.   pSort->labelDone = sqlite3VdbeMakeLabel(pParse);

  125778.   sqlite3ExprCodeExprList(pParse, pSort->pOrderBy, regBase, regOrigData,

  125779.                           SQLITE_ECEL_DUP | (regOrigData? SQLITE_ECEL_REF : 0));

  125780.   if( bSeq ){

  125781.     sqlite3VdbeAddOp2(v, OP_Sequence, pSort->iECursor, regBase+nExpr);

  125782.   }

  125783.   if( nPrefixReg==0 && nData>0 ){

  125784.     sqlite3ExprCodeMove(pParse, regData, regBase+nExpr+bSeq, nData);

  125785.   }

  125786.   if( nOBSat>0 ){

  125787.     int regPrevKey;   /* The first nOBSat columns of the previous row */

  125788.     int addrFirst;    /* Address of the OP_IfNot opcode */

  125789.     int addrJmp;      /* Address of the OP_Jump opcode */

  125790.     VdbeOp *pOp;      /* Opcode that opens the sorter */

  125791.     int nKey;         /* Number of sorting key columns, including OP_Sequence */

  125792.     KeyInfo *pKI;     /* Original KeyInfo on the sorter table */

  125793. 

  125794.     regRecord = makeSorterRecord(pParse, pSort, pSelect, regBase, nBase);

  125795.     regPrevKey = pParse->nMem+1;

  125796.     pParse->nMem += pSort->nOBSat;

  125797.     nKey = nExpr - pSort->nOBSat + bSeq;

  125798.     if( bSeq ){

  125799.       addrFirst = sqlite3VdbeAddOp1(v, OP_IfNot, regBase+nExpr); 

  125800.     }else{

  125801.       addrFirst = sqlite3VdbeAddOp1(v, OP_SequenceTest, pSort->iECursor);

  125802.     }

  125803.     VdbeCoverage(v);

  125804.     sqlite3VdbeAddOp3(v, OP_Compare, regPrevKey, regBase, pSort->nOBSat);

  125805.     pOp = sqlite3VdbeGetOp(v, pSort->addrSortIndex);

  125806.     if( pParse->db->mallocFailed ) return;

  125807.     pOp->p2 = nKey + nData;

  125808.     pKI = pOp->p4.pKeyInfo;

  125809.     memset(pKI->aSortOrder, 0, pKI->nKeyField); /* Makes OP_Jump testable */

  125810.     sqlite3VdbeChangeP4(v, -1, (char*)pKI, P4_KEYINFO);

  125811.     testcase( pKI->nAllField > pKI->nKeyField+2 );

  125812.     pOp->p4.pKeyInfo = sqlite3KeyInfoFromExprList(pParse,pSort->pOrderBy,nOBSat,

  125813.                                            pKI->nAllField-pKI->nKeyField-1);

  125814.     addrJmp = sqlite3VdbeCurrentAddr(v);

  125815.     sqlite3VdbeAddOp3(v, OP_Jump, addrJmp+1, 0, addrJmp+1); VdbeCoverage(v);

  125816.     pSort->labelBkOut = sqlite3VdbeMakeLabel(pParse);

  125817.     pSort->regReturn = ++pParse->nMem;

  125818.     sqlite3VdbeAddOp2(v, OP_Gosub, pSort->regReturn, pSort->labelBkOut);

  125819.     sqlite3VdbeAddOp1(v, OP_ResetSorter, pSort->iECursor);

  125820.     if( iLimit ){

  125821.       sqlite3VdbeAddOp2(v, OP_IfNot, iLimit, pSort->labelDone);

  125822.       VdbeCoverage(v);

  125823.     }

  125824.     sqlite3VdbeJumpHere(v, addrFirst);

  125825.     sqlite3ExprCodeMove(pParse, regBase, regPrevKey, pSort->nOBSat);

  125826.     sqlite3VdbeJumpHere(v, addrJmp);

  125827.   }

  125828.   if( iLimit ){

  125829.     /* At this point the values for the new sorter entry are stored

  125830.     ** in an array of registers. They need to be composed into a record

  125831.     ** and inserted into the sorter if either (a) there are currently

  125832.     ** less than LIMIT+OFFSET items or (b) the new record is smaller than 

  125833.     ** the largest record currently in the sorter. If (b) is true and there

  125834.     ** are already LIMIT+OFFSET items in the sorter, delete the largest

  125835.     ** entry before inserting the new one. This way there are never more 

  125836.     ** than LIMIT+OFFSET items in the sorter.

  125837.     **

  125838.     ** If the new record does not need to be inserted into the sorter,

  125839.     ** jump to the next iteration of the loop. If the pSort->labelOBLopt

  125840.     ** value is not zero, then it is a label of where to jump.  Otherwise,

  125841.     ** just bypass the row insert logic.  See the header comment on the

  125842.     ** sqlite3WhereOrderByLimitOptLabel() function for additional info.

  125843.     */

  125844.     int iCsr = pSort->iECursor;

  125845.     sqlite3VdbeAddOp2(v, OP_IfNotZero, iLimit, sqlite3VdbeCurrentAddr(v)+4);

  125846.     VdbeCoverage(v);

  125847.     sqlite3VdbeAddOp2(v, OP_Last, iCsr, 0);

  125848.     iSkip = sqlite3VdbeAddOp4Int(v, OP_IdxLE,

  125849.                                  iCsr, 0, regBase+nOBSat, nExpr-nOBSat);

  125850.     VdbeCoverage(v);

  125851.     sqlite3VdbeAddOp1(v, OP_Delete, iCsr);

  125852.   }

  125853.   if( regRecord==0 ){

  125854.     regRecord = makeSorterRecord(pParse, pSort, pSelect, regBase, nBase);

  125855.   }

  125856.   if( pSort->sortFlags & SORTFLAG_UseSorter ){

  125857.     op = OP_SorterInsert;

  125858.   }else{

  125859.     op = OP_IdxInsert;

  125860.   }

  125861.   sqlite3VdbeAddOp4Int(v, op, pSort->iECursor, regRecord,

  125862.                        regBase+nOBSat, nBase-nOBSat);

  125863.   if( iSkip ){

  125864.     sqlite3VdbeChangeP2(v, iSkip,

  125865.          pSort->labelOBLopt ? pSort->labelOBLopt : sqlite3VdbeCurrentAddr(v));

  125866.   }

  125867. }

  125868. 

  125869. /*

  125870. ** Add code to implement the OFFSET

  125871. */

  125872. static void codeOffset(

  125873.   Vdbe *v,          /* Generate code into this VM */

  125874.   int iOffset,      /* Register holding the offset counter */

  125875.   int iContinue     /* Jump here to skip the current record */

  125876. ){

  125877.   if( iOffset>0 ){

  125878.     sqlite3VdbeAddOp3(v, OP_IfPos, iOffset, iContinue, 1); VdbeCoverage(v);

  125879.     VdbeComment((v, "OFFSET"));

  125880.   }

  125881. }

  125882. 

  125883. /*

  125884. ** Add code that will check to make sure the N registers starting at iMem

  125885. ** form a distinct entry.  iTab is a sorting index that holds previously

  125886. ** seen combinations of the N values.  A new entry is made in iTab

  125887. ** if the current N values are new.

  125888. **

  125889. ** A jump to addrRepeat is made and the N+1 values are popped from the

  125890. ** stack if the top N elements are not distinct.

  125891. */

  125892. static void codeDistinct(

  125893.   Parse *pParse,     /* Parsing and code generating context */

  125894.   int iTab,          /* A sorting index used to test for distinctness */

  125895.   int addrRepeat,    /* Jump to here if not distinct */

  125896.   int N,             /* Number of elements */

  125897.   int iMem           /* First element */

  125898. ){

  125899.   Vdbe *v;

  125900.   int r1;

  125901. 

  125902.   v = pParse->pVdbe;

  125903.   r1 = sqlite3GetTempReg(pParse);

  125904.   sqlite3VdbeAddOp4Int(v, OP_Found, iTab, addrRepeat, iMem, N); VdbeCoverage(v);

  125905.   sqlite3VdbeAddOp3(v, OP_MakeRecord, iMem, N, r1);

  125906.   sqlite3VdbeAddOp4Int(v, OP_IdxInsert, iTab, r1, iMem, N);

  125907.   sqlite3VdbeChangeP5(v, OPFLAG_USESEEKRESULT);

  125908.   sqlite3ReleaseTempReg(pParse, r1);

  125909. }

  125910. 

  125911. #ifdef SQLITE_ENABLE_SORTER_REFERENCES

  125912. /*

  125913. ** This function is called as part of inner-loop generation for a SELECT

  125914. ** statement with an ORDER BY that is not optimized by an index. It 

  125915. ** determines the expressions, if any, that the sorter-reference 

  125916. ** optimization should be used for. The sorter-reference optimization

  125917. ** is used for SELECT queries like:

  125918. **

  125919. **   SELECT a, bigblob FROM t1 ORDER BY a LIMIT 10

  125920. **

  125921. ** If the optimization is used for expression "bigblob", then instead of

  125922. ** storing values read from that column in the sorter records, the PK of

  125923. ** the row from table t1 is stored instead. Then, as records are extracted from

  125924. ** the sorter to return to the user, the required value of bigblob is

  125925. ** retrieved directly from table t1. If the values are very large, this 

  125926. ** can be more efficient than storing them directly in the sorter records.

  125927. **

  125928. ** The ExprList_item.bSorterRef flag is set for each expression in pEList 

  125929. ** for which the sorter-reference optimization should be enabled. 

  125930. ** Additionally, the pSort->aDefer[] array is populated with entries

  125931. ** for all cursors required to evaluate all selected expressions. Finally.

  125932. ** output variable (*ppExtra) is set to an expression list containing

  125933. ** expressions for all extra PK values that should be stored in the

  125934. ** sorter records.

  125935. */

  125936. static void selectExprDefer(

  125937.   Parse *pParse,                  /* Leave any error here */

  125938.   SortCtx *pSort,                 /* Sorter context */

  125939.   ExprList *pEList,               /* Expressions destined for sorter */

  125940.   ExprList **ppExtra              /* Expressions to append to sorter record */

  125941. ){

  125942.   int i;

  125943.   int nDefer = 0;

  125944.   ExprList *pExtra = 0;

  125945.   for(i=0; i<pEList->nExpr; i++){

  125946.     struct ExprList_item *pItem = &pEList->a[i];

  125947.     if( pItem->u.x.iOrderByCol==0 ){

  125948.       Expr *pExpr = pItem->pExpr;

  125949.       Table *pTab = pExpr->y.pTab;

  125950.       if( pExpr->op==TK_COLUMN && pExpr->iColumn>=0 && pTab && !IsVirtual(pTab)

  125951.        && (pTab->aCol[pExpr->iColumn].colFlags & COLFLAG_SORTERREF)

  125952.       ){

  125953.         int j;

  125954.         for(j=0; j<nDefer; j++){

  125955.           if( pSort->aDefer[j].iCsr==pExpr->iTable ) break;

  125956.         }

  125957.         if( j==nDefer ){

  125958.           if( nDefer==ArraySize(pSort->aDefer) ){

  125959.             continue;

  125960.           }else{

  125961.             int nKey = 1;

  125962.             int k;

  125963.             Index *pPk = 0;

  125964.             if( !HasRowid(pTab) ){

  125965.               pPk = sqlite3PrimaryKeyIndex(pTab);

  125966.               nKey = pPk->nKeyCol;

  125967.             }

  125968.             for(k=0; k<nKey; k++){

  125969.               Expr *pNew = sqlite3PExpr(pParse, TK_COLUMN, 0, 0);

  125970.               if( pNew ){

  125971.                 pNew->iTable = pExpr->iTable;

  125972.                 pNew->y.pTab = pExpr->y.pTab;

  125973.                 pNew->iColumn = pPk ? pPk->aiColumn[k] : -1;

  125974.                 pExtra = sqlite3ExprListAppend(pParse, pExtra, pNew);

  125975.               }

  125976.             }

  125977.             pSort->aDefer[nDefer].pTab = pExpr->y.pTab;

  125978.             pSort->aDefer[nDefer].iCsr = pExpr->iTable;

  125979.             pSort->aDefer[nDefer].nKey = nKey;

  125980.             nDefer++;

  125981.           }

  125982.         }

  125983.         pItem->bSorterRef = 1;

  125984.       }

  125985.     }

  125986.   }

  125987.   pSort->nDefer = (u8)nDefer;

  125988.   *ppExtra = pExtra;

  125989. }

  125990. #endif

  125991. 

  125992. /*

  125993. ** This routine generates the code for the inside of the inner loop

  125994. ** of a SELECT.

  125995. **

  125996. ** If srcTab is negative, then the p->pEList expressions

  125997. ** are evaluated in order to get the data for this row.  If srcTab is

  125998. ** zero or more, then data is pulled from srcTab and p->pEList is used only 

  125999. ** to get the number of columns and the collation sequence for each column.

  126000. */

  126001. static void selectInnerLoop(

  126002.   Parse *pParse,          /* The parser context */

  126003.   Select *p,              /* The complete select statement being coded */

  126004.   int srcTab,             /* Pull data from this table if non-negative */

  126005.   SortCtx *pSort,         /* If not NULL, info on how to process ORDER BY */

  126006.   DistinctCtx *pDistinct, /* If not NULL, info on how to process DISTINCT */

  126007.   SelectDest *pDest,      /* How to dispose of the results */

  126008.   int iContinue,          /* Jump here to continue with next row */

  126009.   int iBreak              /* Jump here to break out of the inner loop */

  126010. ){

  126011.   Vdbe *v = pParse->pVdbe;

  126012.   int i;

  126013.   int hasDistinct;            /* True if the DISTINCT keyword is present */

  126014.   int eDest = pDest->eDest;   /* How to dispose of results */

  126015.   int iParm = pDest->iSDParm; /* First argument to disposal method */

  126016.   int nResultCol;             /* Number of result columns */

  126017.   int nPrefixReg = 0;         /* Number of extra registers before regResult */

  126018.   RowLoadInfo sRowLoadInfo;   /* Info for deferred row loading */

  126019. 

  126020.   /* Usually, regResult is the first cell in an array of memory cells

  126021.   ** containing the current result row. In this case regOrig is set to the

  126022.   ** same value. However, if the results are being sent to the sorter, the

  126023.   ** values for any expressions that are also part of the sort-key are omitted

  126024.   ** from this array. In this case regOrig is set to zero.  */

  126025.   int regResult;              /* Start of memory holding current results */

  126026.   int regOrig;                /* Start of memory holding full result (or 0) */

  126027. 

  126028.   assert( v );

  126029.   assert( p->pEList!=0 );

  126030.   hasDistinct = pDistinct ? pDistinct->eTnctType : WHERE_DISTINCT_NOOP;

  126031.   if( pSort && pSort->pOrderBy==0 ) pSort = 0;

  126032.   if( pSort==0 && !hasDistinct ){

  126033.     assert( iContinue!=0 );

  126034.     codeOffset(v, p->iOffset, iContinue);

  126035.   }

  126036. 

  126037.   /* Pull the requested columns.

  126038.   */

  126039.   nResultCol = p->pEList->nExpr;

  126040. 

  126041.   if( pDest->iSdst==0 ){

  126042.     if( pSort ){

  126043.       nPrefixReg = pSort->pOrderBy->nExpr;

  126044.       if( !(pSort->sortFlags & SORTFLAG_UseSorter) ) nPrefixReg++;

  126045.       pParse->nMem += nPrefixReg;

  126046.     }

  126047.     pDest->iSdst = pParse->nMem+1;

  126048.     pParse->nMem += nResultCol;

  126049.   }else if( pDest->iSdst+nResultCol > pParse->nMem ){

  126050.     /* This is an error condition that can result, for example, when a SELECT

  126051.     ** on the right-hand side of an INSERT contains more result columns than

  126052.     ** there are columns in the table on the left.  The error will be caught

  126053.     ** and reported later.  But we need to make sure enough memory is allocated

  126054.     ** to avoid other spurious errors in the meantime. */

  126055.     pParse->nMem += nResultCol;

  126056.   }

  126057.   pDest->nSdst = nResultCol;

  126058.   regOrig = regResult = pDest->iSdst;

  126059.   if( srcTab>=0 ){

  126060.     for(i=0; i<nResultCol; i++){

  126061.       sqlite3VdbeAddOp3(v, OP_Column, srcTab, i, regResult+i);

  126062.       VdbeComment((v, "%s", p->pEList->a[i].zName));

  126063.     }

  126064.   }else if( eDest!=SRT_Exists ){

  126065. #ifdef SQLITE_ENABLE_SORTER_REFERENCES

  126066.     ExprList *pExtra = 0;

  126067. #endif

  126068.     /* If the destination is an EXISTS(...) expression, the actual

  126069.     ** values returned by the SELECT are not required.

  126070.     */

  126071.     u8 ecelFlags;    /* "ecel" is an abbreviation of "ExprCodeExprList" */

  126072.     ExprList *pEList;

  126073.     if( eDest==SRT_Mem || eDest==SRT_Output || eDest==SRT_Coroutine ){

  126074.       ecelFlags = SQLITE_ECEL_DUP;

  126075.     }else{

  126076.       ecelFlags = 0;

  126077.     }

  126078.     if( pSort && hasDistinct==0 && eDest!=SRT_EphemTab && eDest!=SRT_Table ){

  126079.       /* For each expression in p->pEList that is a copy of an expression in

  126080.       ** the ORDER BY clause (pSort->pOrderBy), set the associated 

  126081.       ** iOrderByCol value to one more than the index of the ORDER BY 

  126082.       ** expression within the sort-key that pushOntoSorter() will generate.

  126083.       ** This allows the p->pEList field to be omitted from the sorted record,

  126084.       ** saving space and CPU cycles.  */

  126085.       ecelFlags |= (SQLITE_ECEL_OMITREF|SQLITE_ECEL_REF);

  126086. 

  126087.       for(i=pSort->nOBSat; i<pSort->pOrderBy->nExpr; i++){

  126088.         int j;

  126089.         if( (j = pSort->pOrderBy->a[i].u.x.iOrderByCol)>0 ){

  126090.           p->pEList->a[j-1].u.x.iOrderByCol = i+1-pSort->nOBSat;

  126091.         }

  126092.       }

  126093. #ifdef SQLITE_ENABLE_SORTER_REFERENCES

  126094.       selectExprDefer(pParse, pSort, p->pEList, &pExtra);

  126095.       if( pExtra && pParse->db->mallocFailed==0 ){

  126096.         /* If there are any extra PK columns to add to the sorter records,

  126097.         ** allocate extra memory cells and adjust the OpenEphemeral 

  126098.         ** instruction to account for the larger records. This is only

  126099.         ** required if there are one or more WITHOUT ROWID tables with

  126100.         ** composite primary keys in the SortCtx.aDefer[] array.  */

  126101.         VdbeOp *pOp = sqlite3VdbeGetOp(v, pSort->addrSortIndex);

  126102.         pOp->p2 += (pExtra->nExpr - pSort->nDefer);

  126103.         pOp->p4.pKeyInfo->nAllField += (pExtra->nExpr - pSort->nDefer);

  126104.         pParse->nMem += pExtra->nExpr;

  126105.       }

  126106. #endif

  126107. 

  126108.       /* Adjust nResultCol to account for columns that are omitted

  126109.       ** from the sorter by the optimizations in this branch */

  126110.       pEList = p->pEList;

  126111.       for(i=0; i<pEList->nExpr; i++){

  126112.         if( pEList->a[i].u.x.iOrderByCol>0

  126113. #ifdef SQLITE_ENABLE_SORTER_REFERENCES

  126114.          || pEList->a[i].bSorterRef

  126115. #endif

  126116.         ){

  126117.           nResultCol--;

  126118.           regOrig = 0;

  126119.         }

  126120.       }

  126121. 

  126122.       testcase( regOrig );

  126123.       testcase( eDest==SRT_Set );

  126124.       testcase( eDest==SRT_Mem );

  126125.       testcase( eDest==SRT_Coroutine );

  126126.       testcase( eDest==SRT_Output );

  126127.       assert( eDest==SRT_Set || eDest==SRT_Mem 

  126128.            || eDest==SRT_Coroutine || eDest==SRT_Output );

  126129.     }

  126130.     sRowLoadInfo.regResult = regResult;

  126131.     sRowLoadInfo.ecelFlags = ecelFlags;

  126132. #ifdef SQLITE_ENABLE_SORTER_REFERENCES

  126133.     sRowLoadInfo.pExtra = pExtra;

  126134.     sRowLoadInfo.regExtraResult = regResult + nResultCol;

  126135.     if( pExtra ) nResultCol += pExtra->nExpr;

  126136. #endif

  126137.     if( p->iLimit

  126138.      && (ecelFlags & SQLITE_ECEL_OMITREF)!=0 

  126139.      && nPrefixReg>0

  126140.     ){

  126141.       assert( pSort!=0 );

  126142.       assert( hasDistinct==0 );

  126143.       pSort->pDeferredRowLoad = &sRowLoadInfo;

  126144.       regOrig = 0;

  126145.     }else{

  126146.       innerLoopLoadRow(pParse, p, &sRowLoadInfo);

  126147.     }

  126148.   }

  126149. 

  126150.   /* If the DISTINCT keyword was present on the SELECT statement

  126151.   ** and this row has been seen before, then do not make this row

  126152.   ** part of the result.

  126153.   */

  126154.   if( hasDistinct ){

  126155.     switch( pDistinct->eTnctType ){

  126156.       case WHERE_DISTINCT_ORDERED: {

  126157.         VdbeOp *pOp;            /* No longer required OpenEphemeral instr. */

  126158.         int iJump;              /* Jump destination */

  126159.         int regPrev;            /* Previous row content */

  126160. 

  126161.         /* Allocate space for the previous row */

  126162.         regPrev = pParse->nMem+1;

  126163.         pParse->nMem += nResultCol;

  126164. 

  126165.         /* Change the OP_OpenEphemeral coded earlier to an OP_Null

  126166.         ** sets the MEM_Cleared bit on the first register of the

  126167.         ** previous value.  This will cause the OP_Ne below to always

  126168.         ** fail on the first iteration of the loop even if the first

  126169.         ** row is all NULLs.

  126170.         */

  126171.         sqlite3VdbeChangeToNoop(v, pDistinct->addrTnct);

  126172.         pOp = sqlite3VdbeGetOp(v, pDistinct->addrTnct);

  126173.         pOp->opcode = OP_Null;

  126174.         pOp->p1 = 1;

  126175.         pOp->p2 = regPrev;

  126176. 

  126177.         iJump = sqlite3VdbeCurrentAddr(v) + nResultCol;

  126178.         for(i=0; i<nResultCol; i++){

  126179.           CollSeq *pColl = sqlite3ExprCollSeq(pParse, p->pEList->a[i].pExpr);

  126180.           if( i<nResultCol-1 ){

  126181.             sqlite3VdbeAddOp3(v, OP_Ne, regResult+i, iJump, regPrev+i);

  126182.             VdbeCoverage(v);

  126183.           }else{

  126184.             sqlite3VdbeAddOp3(v, OP_Eq, regResult+i, iContinue, regPrev+i);

  126185.             VdbeCoverage(v);

  126186.            }

  126187.           sqlite3VdbeChangeP4(v, -1, (const char *)pColl, P4_COLLSEQ);

  126188.           sqlite3VdbeChangeP5(v, SQLITE_NULLEQ);

  126189.         }

  126190.         assert( sqlite3VdbeCurrentAddr(v)==iJump || pParse->db->mallocFailed );

  126191.         sqlite3VdbeAddOp3(v, OP_Copy, regResult, regPrev, nResultCol-1);

  126192.         break;

  126193.       }

  126194. 

  126195.       case WHERE_DISTINCT_UNIQUE: {

  126196.         sqlite3VdbeChangeToNoop(v, pDistinct->addrTnct);

  126197.         break;

  126198.       }

  126199. 

  126200.       default: {

  126201.         assert( pDistinct->eTnctType==WHERE_DISTINCT_UNORDERED );

  126202.         codeDistinct(pParse, pDistinct->tabTnct, iContinue, nResultCol,

  126203.                      regResult);

  126204.         break;

  126205.       }

  126206.     }

  126207.     if( pSort==0 ){

  126208.       codeOffset(v, p->iOffset, iContinue);

  126209.     }

  126210.   }

  126211. 

  126212.   switch( eDest ){

  126213.     /* In this mode, write each query result to the key of the temporary

  126214.     ** table iParm.

  126215.     */

  126216. #ifndef SQLITE_OMIT_COMPOUND_SELECT

  126217.     case SRT_Union: {

  126218.       int r1;

  126219.       r1 = sqlite3GetTempReg(pParse);

  126220.       sqlite3VdbeAddOp3(v, OP_MakeRecord, regResult, nResultCol, r1);

  126221.       sqlite3VdbeAddOp4Int(v, OP_IdxInsert, iParm, r1, regResult, nResultCol);

  126222.       sqlite3ReleaseTempReg(pParse, r1);

  126223.       break;

  126224.     }

  126225. 

  126226.     /* Construct a record from the query result, but instead of

  126227.     ** saving that record, use it as a key to delete elements from

  126228.     ** the temporary table iParm.

  126229.     */

  126230.     case SRT_Except: {

  126231.       sqlite3VdbeAddOp3(v, OP_IdxDelete, iParm, regResult, nResultCol);

  126232.       break;

  126233.     }

  126234. #endif /* SQLITE_OMIT_COMPOUND_SELECT */

  126235. 

  126236.     /* Store the result as data using a unique key.

  126237.     */

  126238.     case SRT_Fifo:

  126239.     case SRT_DistFifo:

  126240.     case SRT_Table:

  126241.     case SRT_EphemTab: {

  126242.       int r1 = sqlite3GetTempRange(pParse, nPrefixReg+1);

  126243.       testcase( eDest==SRT_Table );

  126244.       testcase( eDest==SRT_EphemTab );

  126245.       testcase( eDest==SRT_Fifo );

  126246.       testcase( eDest==SRT_DistFifo );

  126247.       sqlite3VdbeAddOp3(v, OP_MakeRecord, regResult, nResultCol, r1+nPrefixReg);

  126248. #ifndef SQLITE_OMIT_CTE

  126249.       if( eDest==SRT_DistFifo ){

  126250.         /* If the destination is DistFifo, then cursor (iParm+1) is open

  126251.         ** on an ephemeral index. If the current row is already present

  126252.         ** in the index, do not write it to the output. If not, add the

  126253.         ** current row to the index and proceed with writing it to the

  126254.         ** output table as well.  */

  126255.         int addr = sqlite3VdbeCurrentAddr(v) + 4;

  126256.         sqlite3VdbeAddOp4Int(v, OP_Found, iParm+1, addr, r1, 0);

  126257.         VdbeCoverage(v);

  126258.         sqlite3VdbeAddOp4Int(v, OP_IdxInsert, iParm+1, r1,regResult,nResultCol);

  126259.         assert( pSort==0 );

  126260.       }

  126261. #endif

  126262.       if( pSort ){

  126263.         assert( regResult==regOrig );

  126264.         pushOntoSorter(pParse, pSort, p, r1+nPrefixReg, regOrig, 1, nPrefixReg);

  126265.       }else{

  126266.         int r2 = sqlite3GetTempReg(pParse);

  126267.         sqlite3VdbeAddOp2(v, OP_NewRowid, iParm, r2);

  126268.         sqlite3VdbeAddOp3(v, OP_Insert, iParm, r1, r2);

  126269.         sqlite3VdbeChangeP5(v, OPFLAG_APPEND);

  126270.         sqlite3ReleaseTempReg(pParse, r2);

  126271.       }

  126272.       sqlite3ReleaseTempRange(pParse, r1, nPrefixReg+1);

  126273.       break;

  126274.     }

  126275. 

  126276. #ifndef SQLITE_OMIT_SUBQUERY

  126277.     /* If we are creating a set for an "expr IN (SELECT ...)" construct,

  126278.     ** then there should be a single item on the stack.  Write this

  126279.     ** item into the set table with bogus data.

  126280.     */

  126281.     case SRT_Set: {

  126282.       if( pSort ){

  126283.         /* At first glance you would think we could optimize out the

  126284.         ** ORDER BY in this case since the order of entries in the set

  126285.         ** does not matter.  But there might be a LIMIT clause, in which

  126286.         ** case the order does matter */

  126287.         pushOntoSorter(

  126288.             pParse, pSort, p, regResult, regOrig, nResultCol, nPrefixReg);

  126289.       }else{

  126290.         int r1 = sqlite3GetTempReg(pParse);

  126291.         assert( sqlite3Strlen30(pDest->zAffSdst)==nResultCol );

  126292.         sqlite3VdbeAddOp4(v, OP_MakeRecord, regResult, nResultCol, 

  126293.             r1, pDest->zAffSdst, nResultCol);

  126294.         sqlite3VdbeAddOp4Int(v, OP_IdxInsert, iParm, r1, regResult, nResultCol);

  126295.         sqlite3ReleaseTempReg(pParse, r1);

  126296.       }

  126297.       break;

  126298.     }

  126299. 

  126300.     /* If any row exist in the result set, record that fact and abort.

  126301.     */

  126302.     case SRT_Exists: {

  126303.       sqlite3VdbeAddOp2(v, OP_Integer, 1, iParm);

  126304.       /* The LIMIT clause will terminate the loop for us */

  126305.       break;

  126306.     }

  126307. 

  126308.     /* If this is a scalar select that is part of an expression, then

  126309.     ** store the results in the appropriate memory cell or array of 

  126310.     ** memory cells and break out of the scan loop.

  126311.     */

  126312.     case SRT_Mem: {

  126313.       if( pSort ){

  126314.         assert( nResultCol<=pDest->nSdst );

  126315.         pushOntoSorter(

  126316.             pParse, pSort, p, regResult, regOrig, nResultCol, nPrefixReg);

  126317.       }else{

  126318.         assert( nResultCol==pDest->nSdst );

  126319.         assert( regResult==iParm );

  126320.         /* The LIMIT clause will jump out of the loop for us */

  126321.       }

  126322.       break;

  126323.     }

  126324. #endif /* #ifndef SQLITE_OMIT_SUBQUERY */

  126325. 

  126326.     case SRT_Coroutine:       /* Send data to a co-routine */

  126327.     case SRT_Output: {        /* Return the results */

  126328.       testcase( eDest==SRT_Coroutine );

  126329.       testcase( eDest==SRT_Output );

  126330.       if( pSort ){

  126331.         pushOntoSorter(pParse, pSort, p, regResult, regOrig, nResultCol,

  126332.                        nPrefixReg);

  126333.       }else if( eDest==SRT_Coroutine ){

  126334.         sqlite3VdbeAddOp1(v, OP_Yield, pDest->iSDParm);

  126335.       }else{

  126336.         sqlite3VdbeAddOp2(v, OP_ResultRow, regResult, nResultCol);

  126337.       }

  126338.       break;

  126339.     }

  126340. 

  126341. #ifndef SQLITE_OMIT_CTE

  126342.     /* Write the results into a priority queue that is order according to

  126343.     ** pDest->pOrderBy (in pSO).  pDest->iSDParm (in iParm) is the cursor for an

  126344.     ** index with pSO->nExpr+2 columns.  Build a key using pSO for the first

  126345.     ** pSO->nExpr columns, then make sure all keys are unique by adding a

  126346.     ** final OP_Sequence column.  The last column is the record as a blob.

  126347.     */

  126348.     case SRT_DistQueue:

  126349.     case SRT_Queue: {

  126350.       int nKey;

  126351.       int r1, r2, r3;

  126352.       int addrTest = 0;

  126353.       ExprList *pSO;

  126354.       pSO = pDest->pOrderBy;

  126355.       assert( pSO );

  126356.       nKey = pSO->nExpr;

  126357.       r1 = sqlite3GetTempReg(pParse);

  126358.       r2 = sqlite3GetTempRange(pParse, nKey+2);

  126359.       r3 = r2+nKey+1;

  126360.       if( eDest==SRT_DistQueue ){

  126361.         /* If the destination is DistQueue, then cursor (iParm+1) is open

  126362.         ** on a second ephemeral index that holds all values every previously

  126363.         ** added to the queue. */

  126364.         addrTest = sqlite3VdbeAddOp4Int(v, OP_Found, iParm+1, 0, 

  126365.                                         regResult, nResultCol);

  126366.         VdbeCoverage(v);

  126367.       }

  126368.       sqlite3VdbeAddOp3(v, OP_MakeRecord, regResult, nResultCol, r3);

  126369.       if( eDest==SRT_DistQueue ){

  126370.         sqlite3VdbeAddOp2(v, OP_IdxInsert, iParm+1, r3);

  126371.         sqlite3VdbeChangeP5(v, OPFLAG_USESEEKRESULT);

  126372.       }

  126373.       for(i=0; i<nKey; i++){

  126374.         sqlite3VdbeAddOp2(v, OP_SCopy,

  126375.                           regResult + pSO->a[i].u.x.iOrderByCol - 1,

  126376.                           r2+i);

  126377.       }

  126378.       sqlite3VdbeAddOp2(v, OP_Sequence, iParm, r2+nKey);

  126379.       sqlite3VdbeAddOp3(v, OP_MakeRecord, r2, nKey+2, r1);

  126380.       sqlite3VdbeAddOp4Int(v, OP_IdxInsert, iParm, r1, r2, nKey+2);

  126381.       if( addrTest ) sqlite3VdbeJumpHere(v, addrTest);

  126382.       sqlite3ReleaseTempReg(pParse, r1);

  126383.       sqlite3ReleaseTempRange(pParse, r2, nKey+2);

  126384.       break;

  126385.     }

  126386. #endif /* SQLITE_OMIT_CTE */

  126387. 

  126388. 

  126389. 

  126390. #if !defined(SQLITE_OMIT_TRIGGER)

  126391.     /* Discard the results.  This is used for SELECT statements inside

  126392.     ** the body of a TRIGGER.  The purpose of such selects is to call

  126393.     ** user-defined functions that have side effects.  We do not care

  126394.     ** about the actual results of the select.

  126395.     */

  126396.     default: {

  126397.       assert( eDest==SRT_Discard );

  126398.       break;

  126399.     }

  126400. #endif

  126401.   }

  126402. 

  126403.   /* Jump to the end of the loop if the LIMIT is reached.  Except, if

  126404.   ** there is a sorter, in which case the sorter has already limited

  126405.   ** the output for us.

  126406.   */

  126407.   if( pSort==0 && p->iLimit ){

  126408.     sqlite3VdbeAddOp2(v, OP_DecrJumpZero, p->iLimit, iBreak); VdbeCoverage(v);

  126409.   }

  126410. }

  126411. 

  126412. /*

  126413. ** Allocate a KeyInfo object sufficient for an index of N key columns and

  126414. ** X extra columns.

  126415. */

  126416. SQLITE_PRIVATE KeyInfo *sqlite3KeyInfoAlloc(sqlite3 *db, int N, int X){

  126417.   int nExtra = (N+X)*(sizeof(CollSeq*)+1) - sizeof(CollSeq*);

  126418.   KeyInfo *p = sqlite3DbMallocRawNN(db, sizeof(KeyInfo) + nExtra);

  126419.   if( p ){

  126420.     p->aSortOrder = (u8*)&p->aColl[N+X];

  126421.     p->nKeyField = (u16)N;

  126422.     p->nAllField = (u16)(N+X);

  126423.     p->enc = ENC(db);

  126424.     p->db = db;

  126425.     p->nRef = 1;

  126426.     memset(&p[1], 0, nExtra);

  126427.   }else{

  126428.     sqlite3OomFault(db);

  126429.   }

  126430.   return p;

  126431. }

  126432. 

  126433. /*

  126434. ** Deallocate a KeyInfo object

  126435. */

  126436. SQLITE_PRIVATE void sqlite3KeyInfoUnref(KeyInfo *p){

  126437.   if( p ){

  126438.     assert( p->nRef>0 );

  126439.     p->nRef--;

  126440.     if( p->nRef==0 ) sqlite3DbFreeNN(p->db, p);

  126441.   }

  126442. }

  126443. 

  126444. /*

  126445. ** Make a new pointer to a KeyInfo object

  126446. */

  126447. SQLITE_PRIVATE KeyInfo *sqlite3KeyInfoRef(KeyInfo *p){

  126448.   if( p ){

  126449.     assert( p->nRef>0 );

  126450.     p->nRef++;

  126451.   }

  126452.   return p;

  126453. }

  126454. 

  126455. #ifdef SQLITE_DEBUG

  126456. /*

  126457. ** Return TRUE if a KeyInfo object can be change.  The KeyInfo object

  126458. ** can only be changed if this is just a single reference to the object.

  126459. **

  126460. ** This routine is used only inside of assert() statements.

  126461. */

  126462. SQLITE_PRIVATE int sqlite3KeyInfoIsWriteable(KeyInfo *p){ return p->nRef==1; }

  126463. #endif /* SQLITE_DEBUG */

  126464. 

  126465. /*

  126466. ** Given an expression list, generate a KeyInfo structure that records

  126467. ** the collating sequence for each expression in that expression list.

  126468. **

  126469. ** If the ExprList is an ORDER BY or GROUP BY clause then the resulting

  126470. ** KeyInfo structure is appropriate for initializing a virtual index to

  126471. ** implement that clause.  If the ExprList is the result set of a SELECT

  126472. ** then the KeyInfo structure is appropriate for initializing a virtual

  126473. ** index to implement a DISTINCT test.

  126474. **

  126475. ** Space to hold the KeyInfo structure is obtained from malloc.  The calling

  126476. ** function is responsible for seeing that this structure is eventually

  126477. ** freed.

  126478. */

  126479. SQLITE_PRIVATE KeyInfo *sqlite3KeyInfoFromExprList(

  126480.   Parse *pParse,       /* Parsing context */

  126481.   ExprList *pList,     /* Form the KeyInfo object from this ExprList */

  126482.   int iStart,          /* Begin with this column of pList */

  126483.   int nExtra           /* Add this many extra columns to the end */

  126484. ){

  126485.   int nExpr;

  126486.   KeyInfo *pInfo;

  126487.   struct ExprList_item *pItem;

  126488.   sqlite3 *db = pParse->db;

  126489.   int i;

  126490. 

  126491.   nExpr = pList->nExpr;

  126492.   pInfo = sqlite3KeyInfoAlloc(db, nExpr-iStart, nExtra+1);

  126493.   if( pInfo ){

  126494.     assert( sqlite3KeyInfoIsWriteable(pInfo) );

  126495.     for(i=iStart, pItem=pList->a+iStart; i<nExpr; i++, pItem++){

  126496.       pInfo->aColl[i-iStart] = sqlite3ExprNNCollSeq(pParse, pItem->pExpr);

  126497.       pInfo->aSortOrder[i-iStart] = pItem->sortOrder;

  126498.     }

  126499.   }

  126500.   return pInfo;

  126501. }

  126502. 

  126503. /*

  126504. ** Name of the connection operator, used for error messages.

  126505. */

  126506. static const char *selectOpName(int id){

  126507.   char *z;

  126508.   switch( id ){

  126509.     case TK_ALL:       z = "UNION ALL";   break;

  126510.     case TK_INTERSECT: z = "INTERSECT";   break;

  126511.     case TK_EXCEPT:    z = "EXCEPT";      break;

  126512.     default:           z = "UNION";       break;

  126513.   }

  126514.   return z;

  126515. }

  126516. 

  126517. #ifndef SQLITE_OMIT_EXPLAIN

  126518. /*

  126519. ** Unless an "EXPLAIN QUERY PLAN" command is being processed, this function

  126520. ** is a no-op. Otherwise, it adds a single row of output to the EQP result,

  126521. ** where the caption is of the form:

  126522. **

  126523. **   "USE TEMP B-TREE FOR xxx"

  126524. **

  126525. ** where xxx is one of "DISTINCT", "ORDER BY" or "GROUP BY". Exactly which

  126526. ** is determined by the zUsage argument.

  126527. */

  126528. static void explainTempTable(Parse *pParse, const char *zUsage){

  126529.   ExplainQueryPlan((pParse, 0, "USE TEMP B-TREE FOR %s", zUsage));

  126530. }

  126531. 

  126532. /*

  126533. ** Assign expression b to lvalue a. A second, no-op, version of this macro

  126534. ** is provided when SQLITE_OMIT_EXPLAIN is defined. This allows the code

  126535. ** in sqlite3Select() to assign values to structure member variables that

  126536. ** only exist if SQLITE_OMIT_EXPLAIN is not defined without polluting the

  126537. ** code with #ifndef directives.

  126538. */

  126539. # define explainSetInteger(a, b) a = b

  126540. 

  126541. #else

  126542. /* No-op versions of the explainXXX() functions and macros. */

  126543. # define explainTempTable(y,z)

  126544. # define explainSetInteger(y,z)

  126545. #endif

  126546. 

  126547. 

  126548. /*

  126549. ** If the inner loop was generated using a non-null pOrderBy argument,

  126550. ** then the results were placed in a sorter.  After the loop is terminated

  126551. ** we need to run the sorter and output the results.  The following

  126552. ** routine generates the code needed to do that.

  126553. */

  126554. static void generateSortTail(

  126555.   Parse *pParse,    /* Parsing context */

  126556.   Select *p,        /* The SELECT statement */

  126557.   SortCtx *pSort,   /* Information on the ORDER BY clause */

  126558.   int nColumn,      /* Number of columns of data */

  126559.   SelectDest *pDest /* Write the sorted results here */

  126560. ){

  126561.   Vdbe *v = pParse->pVdbe;                     /* The prepared statement */

  126562.   int addrBreak = pSort->labelDone;            /* Jump here to exit loop */

  126563.   int addrContinue = sqlite3VdbeMakeLabel(pParse);/* Jump here for next cycle */

  126564.   int addr;                       /* Top of output loop. Jump for Next. */

  126565.   int addrOnce = 0;

  126566.   int iTab;

  126567.   ExprList *pOrderBy = pSort->pOrderBy;

  126568.   int eDest = pDest->eDest;

  126569.   int iParm = pDest->iSDParm;

  126570.   int regRow;

  126571.   int regRowid;

  126572.   int iCol;

  126573.   int nKey;                       /* Number of key columns in sorter record */

  126574.   int iSortTab;                   /* Sorter cursor to read from */

  126575.   int i;

  126576.   int bSeq;                       /* True if sorter record includes seq. no. */

  126577.   int nRefKey = 0;

  126578.   struct ExprList_item *aOutEx = p->pEList->a;

  126579. 

  126580.   assert( addrBreak<0 );

  126581.   if( pSort->labelBkOut ){

  126582.     sqlite3VdbeAddOp2(v, OP_Gosub, pSort->regReturn, pSort->labelBkOut);

  126583.     sqlite3VdbeGoto(v, addrBreak);

  126584.     sqlite3VdbeResolveLabel(v, pSort->labelBkOut);

  126585.   }

  126586. 

  126587. #ifdef SQLITE_ENABLE_SORTER_REFERENCES

  126588.   /* Open any cursors needed for sorter-reference expressions */

  126589.   for(i=0; i<pSort->nDefer; i++){

  126590.     Table *pTab = pSort->aDefer[i].pTab;

  126591.     int iDb = sqlite3SchemaToIndex(pParse->db, pTab->pSchema);

  126592.     sqlite3OpenTable(pParse, pSort->aDefer[i].iCsr, iDb, pTab, OP_OpenRead);

  126593.     nRefKey = MAX(nRefKey, pSort->aDefer[i].nKey);

  126594.   }

  126595. #endif

  126596. 

  126597.   iTab = pSort->iECursor;

  126598.   if( eDest==SRT_Output || eDest==SRT_Coroutine || eDest==SRT_Mem ){

  126599.     regRowid = 0;

  126600.     regRow = pDest->iSdst;

  126601.   }else{

  126602.     regRowid = sqlite3GetTempReg(pParse);

  126603.     if( eDest==SRT_EphemTab || eDest==SRT_Table ){

  126604.       regRow = sqlite3GetTempReg(pParse);

  126605.       nColumn = 0;

  126606.     }else{

  126607.       regRow = sqlite3GetTempRange(pParse, nColumn);

  126608.     }

  126609.   }

  126610.   nKey = pOrderBy->nExpr - pSort->nOBSat;

  126611.   if( pSort->sortFlags & SORTFLAG_UseSorter ){

  126612.     int regSortOut = ++pParse->nMem;

  126613.     iSortTab = pParse->nTab++;

  126614.     if( pSort->labelBkOut ){

  126615.       addrOnce = sqlite3VdbeAddOp0(v, OP_Once); VdbeCoverage(v);

  126616.     }

  126617.     sqlite3VdbeAddOp3(v, OP_OpenPseudo, iSortTab, regSortOut, 

  126618.         nKey+1+nColumn+nRefKey);

  126619.     if( addrOnce ) sqlite3VdbeJumpHere(v, addrOnce);

  126620.     addr = 1 + sqlite3VdbeAddOp2(v, OP_SorterSort, iTab, addrBreak);

  126621.     VdbeCoverage(v);

  126622.     codeOffset(v, p->iOffset, addrContinue);

  126623.     sqlite3VdbeAddOp3(v, OP_SorterData, iTab, regSortOut, iSortTab);

  126624.     bSeq = 0;

  126625.   }else{

  126626.     addr = 1 + sqlite3VdbeAddOp2(v, OP_Sort, iTab, addrBreak); VdbeCoverage(v);

  126627.     codeOffset(v, p->iOffset, addrContinue);

  126628.     iSortTab = iTab;

  126629.     bSeq = 1;

  126630.   }

  126631.   for(i=0, iCol=nKey+bSeq-1; i<nColumn; i++){

  126632. #ifdef SQLITE_ENABLE_SORTER_REFERENCES

  126633.     if( aOutEx[i].bSorterRef ) continue;

  126634. #endif

  126635.     if( aOutEx[i].u.x.iOrderByCol==0 ) iCol++;

  126636.   }

  126637. #ifdef SQLITE_ENABLE_SORTER_REFERENCES

  126638.   if( pSort->nDefer ){

  126639.     int iKey = iCol+1;

  126640.     int regKey = sqlite3GetTempRange(pParse, nRefKey);

  126641. 

  126642.     for(i=0; i<pSort->nDefer; i++){

  126643.       int iCsr = pSort->aDefer[i].iCsr;

  126644.       Table *pTab = pSort->aDefer[i].pTab;

  126645.       int nKey = pSort->aDefer[i].nKey;

  126646. 

  126647.       sqlite3VdbeAddOp1(v, OP_NullRow, iCsr);

  126648.       if( HasRowid(pTab) ){

  126649.         sqlite3VdbeAddOp3(v, OP_Column, iSortTab, iKey++, regKey);

  126650.         sqlite3VdbeAddOp3(v, OP_SeekRowid, iCsr, 

  126651.             sqlite3VdbeCurrentAddr(v)+1, regKey);

  126652.       }else{

  126653.         int k;

  126654.         int iJmp;

  126655.         assert( sqlite3PrimaryKeyIndex(pTab)->nKeyCol==nKey );

  126656.         for(k=0; k<nKey; k++){

  126657.           sqlite3VdbeAddOp3(v, OP_Column, iSortTab, iKey++, regKey+k);

  126658.         }

  126659.         iJmp = sqlite3VdbeCurrentAddr(v);

  126660.         sqlite3VdbeAddOp4Int(v, OP_SeekGE, iCsr, iJmp+2, regKey, nKey);

  126661.         sqlite3VdbeAddOp4Int(v, OP_IdxLE, iCsr, iJmp+3, regKey, nKey);

  126662.         sqlite3VdbeAddOp1(v, OP_NullRow, iCsr);

  126663.       }

  126664.     }

  126665.     sqlite3ReleaseTempRange(pParse, regKey, nRefKey);

  126666.   }

  126667. #endif

  126668.   for(i=nColumn-1; i>=0; i--){

  126669. #ifdef SQLITE_ENABLE_SORTER_REFERENCES

  126670.     if( aOutEx[i].bSorterRef ){

  126671.       sqlite3ExprCode(pParse, aOutEx[i].pExpr, regRow+i);

  126672.     }else

  126673. #endif

  126674.     {

  126675.       int iRead;

  126676.       if( aOutEx[i].u.x.iOrderByCol ){

  126677.         iRead = aOutEx[i].u.x.iOrderByCol-1;

  126678.       }else{

  126679.         iRead = iCol--;

  126680.       }

  126681.       sqlite3VdbeAddOp3(v, OP_Column, iSortTab, iRead, regRow+i);

  126682.       VdbeComment((v, "%s", aOutEx[i].zName?aOutEx[i].zName : aOutEx[i].zSpan));

  126683.     }

  126684.   }

  126685.   switch( eDest ){

  126686.     case SRT_Table:

  126687.     case SRT_EphemTab: {

  126688.       sqlite3VdbeAddOp3(v, OP_Column, iSortTab, nKey+bSeq, regRow);

  126689.       sqlite3VdbeAddOp2(v, OP_NewRowid, iParm, regRowid);

  126690.       sqlite3VdbeAddOp3(v, OP_Insert, iParm, regRow, regRowid);

  126691.       sqlite3VdbeChangeP5(v, OPFLAG_APPEND);

  126692.       break;

  126693.     }

  126694. #ifndef SQLITE_OMIT_SUBQUERY

  126695.     case SRT_Set: {

  126696.       assert( nColumn==sqlite3Strlen30(pDest->zAffSdst) );

  126697.       sqlite3VdbeAddOp4(v, OP_MakeRecord, regRow, nColumn, regRowid,

  126698.                         pDest->zAffSdst, nColumn);

  126699.       sqlite3VdbeAddOp4Int(v, OP_IdxInsert, iParm, regRowid, regRow, nColumn);

  126700.       break;

  126701.     }

  126702.     case SRT_Mem: {

  126703.       /* The LIMIT clause will terminate the loop for us */

  126704.       break;

  126705.     }

  126706. #endif

  126707.     default: {

  126708.       assert( eDest==SRT_Output || eDest==SRT_Coroutine ); 

  126709.       testcase( eDest==SRT_Output );

  126710.       testcase( eDest==SRT_Coroutine );

  126711.       if( eDest==SRT_Output ){

  126712.         sqlite3VdbeAddOp2(v, OP_ResultRow, pDest->iSdst, nColumn);

  126713.       }else{

  126714.         sqlite3VdbeAddOp1(v, OP_Yield, pDest->iSDParm);

  126715.       }

  126716.       break;

  126717.     }

  126718.   }

  126719.   if( regRowid ){

  126720.     if( eDest==SRT_Set ){

  126721.       sqlite3ReleaseTempRange(pParse, regRow, nColumn);

  126722.     }else{

  126723.       sqlite3ReleaseTempReg(pParse, regRow);

  126724.     }

  126725.     sqlite3ReleaseTempReg(pParse, regRowid);

  126726.   }

  126727.   /* The bottom of the loop

  126728.   */

  126729.   sqlite3VdbeResolveLabel(v, addrContinue);

  126730.   if( pSort->sortFlags & SORTFLAG_UseSorter ){

  126731.     sqlite3VdbeAddOp2(v, OP_SorterNext, iTab, addr); VdbeCoverage(v);

  126732.   }else{

  126733.     sqlite3VdbeAddOp2(v, OP_Next, iTab, addr); VdbeCoverage(v);

  126734.   }

  126735.   if( pSort->regReturn ) sqlite3VdbeAddOp1(v, OP_Return, pSort->regReturn);

  126736.   sqlite3VdbeResolveLabel(v, addrBreak);

  126737. }

  126738. 

  126739. /*

  126740. ** Return a pointer to a string containing the 'declaration type' of the

  126741. ** expression pExpr. The string may be treated as static by the caller.

  126742. **

  126743. ** Also try to estimate the size of the returned value and return that

  126744. ** result in *pEstWidth.

  126745. **

  126746. ** The declaration type is the exact datatype definition extracted from the

  126747. ** original CREATE TABLE statement if the expression is a column. The

  126748. ** declaration type for a ROWID field is INTEGER. Exactly when an expression

  126749. ** is considered a column can be complex in the presence of subqueries. The

  126750. ** result-set expression in all of the following SELECT statements is 

  126751. ** considered a column by this function.

  126752. **

  126753. **   SELECT col FROM tbl;

  126754. **   SELECT (SELECT col FROM tbl;

  126755. **   SELECT (SELECT col FROM tbl);

  126756. **   SELECT abc FROM (SELECT col AS abc FROM tbl);

  126757. ** 

  126758. ** The declaration type for any expression other than a column is NULL.

  126759. **

  126760. ** This routine has either 3 or 6 parameters depending on whether or not

  126761. ** the SQLITE_ENABLE_COLUMN_METADATA compile-time option is used.

  126762. */

  126763. #ifdef SQLITE_ENABLE_COLUMN_METADATA

  126764. # define columnType(A,B,C,D,E) columnTypeImpl(A,B,C,D,E)

  126765. #else /* if !defined(SQLITE_ENABLE_COLUMN_METADATA) */

  126766. # define columnType(A,B,C,D,E) columnTypeImpl(A,B)

  126767. #endif

  126768. static const char *columnTypeImpl(

  126769.   NameContext *pNC, 

  126770. #ifndef SQLITE_ENABLE_COLUMN_METADATA

  126771.   Expr *pExpr

  126772. #else

  126773.   Expr *pExpr,

  126774.   const char **pzOrigDb,

  126775.   const char **pzOrigTab,

  126776.   const char **pzOrigCol

  126777. #endif

  126778. ){

  126779.   char const *zType = 0;

  126780.   int j;

  126781. #ifdef SQLITE_ENABLE_COLUMN_METADATA

  126782.   char const *zOrigDb = 0;

  126783.   char const *zOrigTab = 0;

  126784.   char const *zOrigCol = 0;

  126785. #endif

  126786. 

  126787.   assert( pExpr!=0 );

  126788.   assert( pNC->pSrcList!=0 );

  126789.   assert( pExpr->op!=TK_AGG_COLUMN );  /* This routine runes before aggregates

  126790.                                        ** are processed */

  126791.   switch( pExpr->op ){

  126792.     case TK_COLUMN: {

  126793.       /* The expression is a column. Locate the table the column is being

  126794.       ** extracted from in NameContext.pSrcList. This table may be real

  126795.       ** database table or a subquery.

  126796.       */

  126797.       Table *pTab = 0;            /* Table structure column is extracted from */

  126798.       Select *pS = 0;             /* Select the column is extracted from */

  126799.       int iCol = pExpr->iColumn;  /* Index of column in pTab */

  126800.       while( pNC && !pTab ){

  126801.         SrcList *pTabList = pNC->pSrcList;

  126802.         for(j=0;j<pTabList->nSrc && pTabList->a[j].iCursor!=pExpr->iTable;j++);

  126803.         if( j<pTabList->nSrc ){

  126804.           pTab = pTabList->a[j].pTab;

  126805.           pS = pTabList->a[j].pSelect;

  126806.         }else{

  126807.           pNC = pNC->pNext;

  126808.         }

  126809.       }

  126810. 

  126811.       if( pTab==0 ){

  126812.         /* At one time, code such as "SELECT new.x" within a trigger would

  126813.         ** cause this condition to run.  Since then, we have restructured how

  126814.         ** trigger code is generated and so this condition is no longer 

  126815.         ** possible. However, it can still be true for statements like

  126816.         ** the following:

  126817.         **

  126818.         **   CREATE TABLE t1(col INTEGER);

  126819.         **   SELECT (SELECT t1.col) FROM FROM t1;

  126820.         **

  126821.         ** when columnType() is called on the expression "t1.col" in the 

  126822.         ** sub-select. In this case, set the column type to NULL, even

  126823.         ** though it should really be "INTEGER".

  126824.         **

  126825.         ** This is not a problem, as the column type of "t1.col" is never

  126826.         ** used. When columnType() is called on the expression 

  126827.         ** "(SELECT t1.col)", the correct type is returned (see the TK_SELECT

  126828.         ** branch below.  */

  126829.         break;

  126830.       }

  126831. 

  126832.       assert( pTab && pExpr->y.pTab==pTab );

  126833.       if( pS ){

  126834.         /* The "table" is actually a sub-select or a view in the FROM clause

  126835.         ** of the SELECT statement. Return the declaration type and origin

  126836.         ** data for the result-set column of the sub-select.

  126837.         */

  126838.         if( iCol>=0 && iCol<pS->pEList->nExpr ){

  126839.           /* If iCol is less than zero, then the expression requests the

  126840.           ** rowid of the sub-select or view. This expression is legal (see 

  126841.           ** test case misc2.2.2) - it always evaluates to NULL.

  126842.           */

  126843.           NameContext sNC;

  126844.           Expr *p = pS->pEList->a[iCol].pExpr;

  126845.           sNC.pSrcList = pS->pSrc;

  126846.           sNC.pNext = pNC;

  126847.           sNC.pParse = pNC->pParse;

  126848.           zType = columnType(&sNC, p,&zOrigDb,&zOrigTab,&zOrigCol); 

  126849.         }

  126850.       }else{

  126851.         /* A real table or a CTE table */

  126852.         assert( !pS );

  126853. #ifdef SQLITE_ENABLE_COLUMN_METADATA

  126854.         if( iCol<0 ) iCol = pTab->iPKey;

  126855.         assert( iCol==XN_ROWID || (iCol>=0 && iCol<pTab->nCol) );

  126856.         if( iCol<0 ){

  126857.           zType = "INTEGER";

  126858.           zOrigCol = "rowid";

  126859.         }else{

  126860.           zOrigCol = pTab->aCol[iCol].zName;

  126861.           zType = sqlite3ColumnType(&pTab->aCol[iCol],0);

  126862.         }

  126863.         zOrigTab = pTab->zName;

  126864.         if( pNC->pParse && pTab->pSchema ){

  126865.           int iDb = sqlite3SchemaToIndex(pNC->pParse->db, pTab->pSchema);

  126866.           zOrigDb = pNC->pParse->db->aDb[iDb].zDbSName;

  126867.         }

  126868. #else

  126869.         assert( iCol==XN_ROWID || (iCol>=0 && iCol<pTab->nCol) );

  126870.         if( iCol<0 ){

  126871.           zType = "INTEGER";

  126872.         }else{

  126873.           zType = sqlite3ColumnType(&pTab->aCol[iCol],0);

  126874.         }

  126875. #endif

  126876.       }

  126877.       break;

  126878.     }

  126879. #ifndef SQLITE_OMIT_SUBQUERY

  126880.     case TK_SELECT: {

  126881.       /* The expression is a sub-select. Return the declaration type and

  126882.       ** origin info for the single column in the result set of the SELECT

  126883.       ** statement.

  126884.       */

  126885.       NameContext sNC;

  126886.       Select *pS = pExpr->x.pSelect;

  126887.       Expr *p = pS->pEList->a[0].pExpr;

  126888.       assert( ExprHasProperty(pExpr, EP_xIsSelect) );

  126889.       sNC.pSrcList = pS->pSrc;

  126890.       sNC.pNext = pNC;

  126891.       sNC.pParse = pNC->pParse;

  126892.       zType = columnType(&sNC, p, &zOrigDb, &zOrigTab, &zOrigCol); 

  126893.       break;

  126894.     }

  126895. #endif

  126896.   }

  126897. 

  126898. #ifdef SQLITE_ENABLE_COLUMN_METADATA  

  126899.   if( pzOrigDb ){

  126900.     assert( pzOrigTab && pzOrigCol );

  126901.     *pzOrigDb = zOrigDb;

  126902.     *pzOrigTab = zOrigTab;

  126903.     *pzOrigCol = zOrigCol;

  126904.   }

  126905. #endif

  126906.   return zType;

  126907. }

  126908. 

  126909. /*

  126910. ** Generate code that will tell the VDBE the declaration types of columns

  126911. ** in the result set.

  126912. */

  126913. static void generateColumnTypes(

  126914.   Parse *pParse,      /* Parser context */

  126915.   SrcList *pTabList,  /* List of tables */

  126916.   ExprList *pEList    /* Expressions defining the result set */

  126917. ){

  126918. #ifndef SQLITE_OMIT_DECLTYPE

  126919.   Vdbe *v = pParse->pVdbe;

  126920.   int i;

  126921.   NameContext sNC;

  126922.   sNC.pSrcList = pTabList;

  126923.   sNC.pParse = pParse;

  126924.   sNC.pNext = 0;

  126925.   for(i=0; i<pEList->nExpr; i++){

  126926.     Expr *p = pEList->a[i].pExpr;

  126927.     const char *zType;

  126928. #ifdef SQLITE_ENABLE_COLUMN_METADATA

  126929.     const char *zOrigDb = 0;

  126930.     const char *zOrigTab = 0;

  126931.     const char *zOrigCol = 0;

  126932.     zType = columnType(&sNC, p, &zOrigDb, &zOrigTab, &zOrigCol);

  126933. 

  126934.     /* The vdbe must make its own copy of the column-type and other 

  126935.     ** column specific strings, in case the schema is reset before this

  126936.     ** virtual machine is deleted.

  126937.     */

  126938.     sqlite3VdbeSetColName(v, i, COLNAME_DATABASE, zOrigDb, SQLITE_TRANSIENT);

  126939.     sqlite3VdbeSetColName(v, i, COLNAME_TABLE, zOrigTab, SQLITE_TRANSIENT);

  126940.     sqlite3VdbeSetColName(v, i, COLNAME_COLUMN, zOrigCol, SQLITE_TRANSIENT);

  126941. #else

  126942.     zType = columnType(&sNC, p, 0, 0, 0);

  126943. #endif

  126944.     sqlite3VdbeSetColName(v, i, COLNAME_DECLTYPE, zType, SQLITE_TRANSIENT);

  126945.   }

  126946. #endif /* !defined(SQLITE_OMIT_DECLTYPE) */

  126947. }

  126948. 

  126949. 

  126950. /*

  126951. ** Compute the column names for a SELECT statement.

  126952. **

  126953. ** The only guarantee that SQLite makes about column names is that if the

  126954. ** column has an AS clause assigning it a name, that will be the name used.

  126955. ** That is the only documented guarantee.  However, countless applications

  126956. ** developed over the years have made baseless assumptions about column names

  126957. ** and will break if those assumptions changes.  Hence, use extreme caution

  126958. ** when modifying this routine to avoid breaking legacy.

  126959. **

  126960. ** See Also: sqlite3ColumnsFromExprList()

  126961. **

  126962. ** The PRAGMA short_column_names and PRAGMA full_column_names settings are

  126963. ** deprecated.  The default setting is short=ON, full=OFF.  99.9% of all

  126964. ** applications should operate this way.  Nevertheless, we need to support the

  126965. ** other modes for legacy:

  126966. **

  126967. **    short=OFF, full=OFF:      Column name is the text of the expression has it

  126968. **                              originally appears in the SELECT statement.  In

  126969. **                              other words, the zSpan of the result expression.

  126970. **

  126971. **    short=ON, full=OFF:       (This is the default setting).  If the result

  126972. **                              refers directly to a table column, then the

  126973. **                              result column name is just the table column

  126974. **                              name: COLUMN.  Otherwise use zSpan.

  126975. **

  126976. **    full=ON, short=ANY:       If the result refers directly to a table column,

  126977. **                              then the result column name with the table name

  126978. **                              prefix, ex: TABLE.COLUMN.  Otherwise use zSpan.

  126979. */

  126980. static void generateColumnNames(

  126981.   Parse *pParse,      /* Parser context */

  126982.   Select *pSelect     /* Generate column names for this SELECT statement */

  126983. ){

  126984.   Vdbe *v = pParse->pVdbe;

  126985.   int i;

  126986.   Table *pTab;

  126987.   SrcList *pTabList;

  126988.   ExprList *pEList;

  126989.   sqlite3 *db = pParse->db;

  126990.   int fullName;    /* TABLE.COLUMN if no AS clause and is a direct table ref */

  126991.   int srcName;     /* COLUMN or TABLE.COLUMN if no AS clause and is direct */

  126992. 

  126993. #ifndef SQLITE_OMIT_EXPLAIN

  126994.   /* If this is an EXPLAIN, skip this step */

  126995.   if( pParse->explain ){

  126996.     return;

  126997.   }

  126998. #endif

  126999. 

  127000.   if( pParse->colNamesSet ) return;

  127001.   /* Column names are determined by the left-most term of a compound select */

  127002.   while( pSelect->pPrior ) pSelect = pSelect->pPrior;

  127003.   SELECTTRACE(1,pParse,pSelect,("generating column names\n"));

  127004.   pTabList = pSelect->pSrc;

  127005.   pEList = pSelect->pEList;

  127006.   assert( v!=0 );

  127007.   assert( pTabList!=0 );

  127008.   pParse->colNamesSet = 1;

  127009.   fullName = (db->flags & SQLITE_FullColNames)!=0;

  127010.   srcName = (db->flags & SQLITE_ShortColNames)!=0 || fullName;

  127011.   sqlite3VdbeSetNumCols(v, pEList->nExpr);

  127012.   for(i=0; i<pEList->nExpr; i++){

  127013.     Expr *p = pEList->a[i].pExpr;

  127014. 

  127015.     assert( p!=0 );

  127016.     assert( p->op!=TK_AGG_COLUMN );  /* Agg processing has not run yet */

  127017.     assert( p->op!=TK_COLUMN || p->y.pTab!=0 ); /* Covering idx not yet coded */

  127018.     if( pEList->a[i].zName ){

  127019.       /* An AS clause always takes first priority */

  127020.       char *zName = pEList->a[i].zName;

  127021.       sqlite3VdbeSetColName(v, i, COLNAME_NAME, zName, SQLITE_TRANSIENT);

  127022.     }else if( srcName && p->op==TK_COLUMN ){

  127023.       char *zCol;

  127024.       int iCol = p->iColumn;

  127025.       pTab = p->y.pTab;

  127026.       assert( pTab!=0 );

  127027.       if( iCol<0 ) iCol = pTab->iPKey;

  127028.       assert( iCol==-1 || (iCol>=0 && iCol<pTab->nCol) );

  127029.       if( iCol<0 ){

  127030.         zCol = "rowid";

  127031.       }else{

  127032.         zCol = pTab->aCol[iCol].zName;

  127033.       }

  127034.       if( fullName ){

  127035.         char *zName = 0;

  127036.         zName = sqlite3MPrintf(db, "%s.%s", pTab->zName, zCol);

  127037.         sqlite3VdbeSetColName(v, i, COLNAME_NAME, zName, SQLITE_DYNAMIC);

  127038.       }else{

  127039.         sqlite3VdbeSetColName(v, i, COLNAME_NAME, zCol, SQLITE_TRANSIENT);

  127040.       }

  127041.     }else{

  127042.       const char *z = pEList->a[i].zSpan;

  127043.       z = z==0 ? sqlite3MPrintf(db, "column%d", i+1) : sqlite3DbStrDup(db, z);

  127044.       sqlite3VdbeSetColName(v, i, COLNAME_NAME, z, SQLITE_DYNAMIC);

  127045.     }

  127046.   }

  127047.   generateColumnTypes(pParse, pTabList, pEList);

  127048. }

  127049. 

  127050. /*

  127051. ** Given an expression list (which is really the list of expressions

  127052. ** that form the result set of a SELECT statement) compute appropriate

  127053. ** column names for a table that would hold the expression list.

  127054. **

  127055. ** All column names will be unique.

  127056. **

  127057. ** Only the column names are computed.  Column.zType, Column.zColl,

  127058. ** and other fields of Column are zeroed.

  127059. **

  127060. ** Return SQLITE_OK on success.  If a memory allocation error occurs,

  127061. ** store NULL in *paCol and 0 in *pnCol and return SQLITE_NOMEM.

  127062. **

  127063. ** The only guarantee that SQLite makes about column names is that if the

  127064. ** column has an AS clause assigning it a name, that will be the name used.

  127065. ** That is the only documented guarantee.  However, countless applications

  127066. ** developed over the years have made baseless assumptions about column names

  127067. ** and will break if those assumptions changes.  Hence, use extreme caution

  127068. ** when modifying this routine to avoid breaking legacy.

  127069. **

  127070. ** See Also: generateColumnNames()

  127071. */

  127072. SQLITE_PRIVATE int sqlite3ColumnsFromExprList(

  127073.   Parse *pParse,          /* Parsing context */

  127074.   ExprList *pEList,       /* Expr list from which to derive column names */

  127075.   i16 *pnCol,             /* Write the number of columns here */

  127076.   Column **paCol          /* Write the new column list here */

  127077. ){

  127078.   sqlite3 *db = pParse->db;   /* Database connection */

  127079.   int i, j;                   /* Loop counters */

  127080.   u32 cnt;                    /* Index added to make the name unique */

  127081.   Column *aCol, *pCol;        /* For looping over result columns */

  127082.   int nCol;                   /* Number of columns in the result set */

  127083.   char *zName;                /* Column name */

  127084.   int nName;                  /* Size of name in zName[] */

  127085.   Hash ht;                    /* Hash table of column names */

  127086. 

  127087.   sqlite3HashInit(&ht);

  127088.   if( pEList ){

  127089.     nCol = pEList->nExpr;

  127090.     aCol = sqlite3DbMallocZero(db, sizeof(aCol[0])*nCol);

  127091.     testcase( aCol==0 );

  127092.     if( nCol>32767 ) nCol = 32767;

  127093.   }else{

  127094.     nCol = 0;

  127095.     aCol = 0;

  127096.   }

  127097.   assert( nCol==(i16)nCol );

  127098.   *pnCol = nCol;

  127099.   *paCol = aCol;

  127100. 

  127101.   for(i=0, pCol=aCol; i<nCol && !db->mallocFailed; i++, pCol++){

  127102.     /* Get an appropriate name for the column

  127103.     */

  127104.     if( (zName = pEList->a[i].zName)!=0 ){

  127105.       /* If the column contains an "AS <name>" phrase, use <name> as the name */

  127106.     }else{

  127107.       Expr *pColExpr = sqlite3ExprSkipCollate(pEList->a[i].pExpr);

  127108.       while( pColExpr->op==TK_DOT ){

  127109.         pColExpr = pColExpr->pRight;

  127110.         assert( pColExpr!=0 );

  127111.       }

  127112.       assert( pColExpr->op!=TK_AGG_COLUMN );

  127113.       if( pColExpr->op==TK_COLUMN ){

  127114.         /* For columns use the column name name */

  127115.         int iCol = pColExpr->iColumn;

  127116.         Table *pTab = pColExpr->y.pTab;

  127117.         assert( pTab!=0 );

  127118.         if( iCol<0 ) iCol = pTab->iPKey;

  127119.         zName = iCol>=0 ? pTab->aCol[iCol].zName : "rowid";

  127120.       }else if( pColExpr->op==TK_ID ){

  127121.         assert( !ExprHasProperty(pColExpr, EP_IntValue) );

  127122.         zName = pColExpr->u.zToken;

  127123.       }else{

  127124.         /* Use the original text of the column expression as its name */

  127125.         zName = pEList->a[i].zSpan;

  127126.       }

  127127.     }

  127128.     if( zName ){

  127129.       zName = sqlite3DbStrDup(db, zName);

  127130.     }else{

  127131.       zName = sqlite3MPrintf(db,"column%d",i+1);

  127132.     }

  127133. 

  127134.     /* Make sure the column name is unique.  If the name is not unique,

  127135.     ** append an integer to the name so that it becomes unique.

  127136.     */

  127137.     cnt = 0;

  127138.     while( zName && sqlite3HashFind(&ht, zName)!=0 ){

  127139.       nName = sqlite3Strlen30(zName);

  127140.       if( nName>0 ){

  127141.         for(j=nName-1; j>0 && sqlite3Isdigit(zName[j]); j--){}

  127142.         if( zName[j]==':' ) nName = j;

  127143.       }

  127144.       zName = sqlite3MPrintf(db, "%.*z:%u", nName, zName, ++cnt);

  127145.       if( cnt>3 ) sqlite3_randomness(sizeof(cnt), &cnt);

  127146.     }

  127147.     pCol->zName = zName;

  127148.     sqlite3ColumnPropertiesFromName(0, pCol);

  127149.     if( zName && sqlite3HashInsert(&ht, zName, pCol)==pCol ){

  127150.       sqlite3OomFault(db);

  127151.     }

  127152.   }

  127153.   sqlite3HashClear(&ht);

  127154.   if( db->mallocFailed ){

  127155.     for(j=0; j<i; j++){

  127156.       sqlite3DbFree(db, aCol[j].zName);

  127157.     }

  127158.     sqlite3DbFree(db, aCol);

  127159.     *paCol = 0;

  127160.     *pnCol = 0;

  127161.     return SQLITE_NOMEM_BKPT;

  127162.   }

  127163.   return SQLITE_OK;

  127164. }

  127165. 

  127166. /*

  127167. ** Add type and collation information to a column list based on

  127168. ** a SELECT statement.

  127169. ** 

  127170. ** The column list presumably came from selectColumnNamesFromExprList().

  127171. ** The column list has only names, not types or collations.  This

  127172. ** routine goes through and adds the types and collations.

  127173. **

  127174. ** This routine requires that all identifiers in the SELECT

  127175. ** statement be resolved.

  127176. */

  127177. SQLITE_PRIVATE void sqlite3SelectAddColumnTypeAndCollation(

  127178.   Parse *pParse,        /* Parsing contexts */

  127179.   Table *pTab,          /* Add column type information to this table */

  127180.   Select *pSelect       /* SELECT used to determine types and collations */

  127181. ){

  127182.   sqlite3 *db = pParse->db;

  127183.   NameContext sNC;

  127184.   Column *pCol;

  127185.   CollSeq *pColl;

  127186.   int i;

  127187.   Expr *p;

  127188.   struct ExprList_item *a;

  127189. 

  127190.   assert( pSelect!=0 );

  127191.   assert( (pSelect->selFlags & SF_Resolved)!=0 );

  127192.   assert( pTab->nCol==pSelect->pEList->nExpr || db->mallocFailed );

  127193.   if( db->mallocFailed ) return;

  127194.   memset(&sNC, 0, sizeof(sNC));

  127195.   sNC.pSrcList = pSelect->pSrc;

  127196.   a = pSelect->pEList->a;

  127197.   for(i=0, pCol=pTab->aCol; i<pTab->nCol; i++, pCol++){

  127198.     const char *zType;

  127199.     int n, m;

  127200.     p = a[i].pExpr;

  127201.     zType = columnType(&sNC, p, 0, 0, 0);

  127202.     /* pCol->szEst = ... // Column size est for SELECT tables never used */

  127203.     pCol->affinity = sqlite3ExprAffinity(p);

  127204.     if( zType ){

  127205.       m = sqlite3Strlen30(zType);

  127206.       n = sqlite3Strlen30(pCol->zName);

  127207.       pCol->zName = sqlite3DbReallocOrFree(db, pCol->zName, n+m+2);

  127208.       if( pCol->zName ){

  127209.         memcpy(&pCol->zName[n+1], zType, m+1);

  127210.         pCol->colFlags |= COLFLAG_HASTYPE;

  127211.       }

  127212.     }

  127213.     if( pCol->affinity==0 ) pCol->affinity = SQLITE_AFF_BLOB;

  127214.     pColl = sqlite3ExprCollSeq(pParse, p);

  127215.     if( pColl && pCol->zColl==0 ){

  127216.       pCol->zColl = sqlite3DbStrDup(db, pColl->zName);

  127217.     }

  127218.   }

  127219.   pTab->szTabRow = 1; /* Any non-zero value works */

  127220. }

  127221. 

  127222. /*

  127223. ** Given a SELECT statement, generate a Table structure that describes

  127224. ** the result set of that SELECT.

  127225. */

  127226. SQLITE_PRIVATE Table *sqlite3ResultSetOfSelect(Parse *pParse, Select *pSelect){

  127227.   Table *pTab;

  127228.   sqlite3 *db = pParse->db;

  127229.   u64 savedFlags;

  127230. 

  127231.   savedFlags = db->flags;

  127232.   db->flags &= ~(u64)SQLITE_FullColNames;

  127233.   db->flags |= SQLITE_ShortColNames;

  127234.   sqlite3SelectPrep(pParse, pSelect, 0);

  127235.   db->flags = savedFlags;

  127236.   if( pParse->nErr ) return 0;

  127237.   while( pSelect->pPrior ) pSelect = pSelect->pPrior;

  127238.   pTab = sqlite3DbMallocZero(db, sizeof(Table) );

  127239.   if( pTab==0 ){

  127240.     return 0;

  127241.   }

  127242.   pTab->nTabRef = 1;

  127243.   pTab->zName = 0;

  127244.   pTab->nRowLogEst = 200; assert( 200==sqlite3LogEst(1048576) );

  127245.   sqlite3ColumnsFromExprList(pParse, pSelect->pEList, &pTab->nCol, &pTab->aCol);

  127246.   sqlite3SelectAddColumnTypeAndCollation(pParse, pTab, pSelect);

  127247.   pTab->iPKey = -1;

  127248.   if( db->mallocFailed ){

  127249.     sqlite3DeleteTable(db, pTab);

  127250.     return 0;

  127251.   }

  127252.   return pTab;

  127253. }

  127254. 

  127255. /*

  127256. ** Get a VDBE for the given parser context.  Create a new one if necessary.

  127257. ** If an error occurs, return NULL and leave a message in pParse.

  127258. */

  127259. SQLITE_PRIVATE Vdbe *sqlite3GetVdbe(Parse *pParse){

  127260.   if( pParse->pVdbe ){

  127261.     return pParse->pVdbe;

  127262.   }

  127263.   if( pParse->pToplevel==0

  127264.    && OptimizationEnabled(pParse->db,SQLITE_FactorOutConst)

  127265.   ){

  127266.     pParse->okConstFactor = 1;

  127267.   }

  127268.   return sqlite3VdbeCreate(pParse);

  127269. }

  127270. 

  127271. 

  127272. /*

  127273. ** Compute the iLimit and iOffset fields of the SELECT based on the

  127274. ** pLimit expressions.  pLimit->pLeft and pLimit->pRight hold the expressions

  127275. ** that appear in the original SQL statement after the LIMIT and OFFSET

  127276. ** keywords.  Or NULL if those keywords are omitted. iLimit and iOffset 

  127277. ** are the integer memory register numbers for counters used to compute 

  127278. ** the limit and offset.  If there is no limit and/or offset, then 

  127279. ** iLimit and iOffset are negative.

  127280. **

  127281. ** This routine changes the values of iLimit and iOffset only if

  127282. ** a limit or offset is defined by pLimit->pLeft and pLimit->pRight.  iLimit

  127283. ** and iOffset should have been preset to appropriate default values (zero)

  127284. ** prior to calling this routine.

  127285. **

  127286. ** The iOffset register (if it exists) is initialized to the value

  127287. ** of the OFFSET.  The iLimit register is initialized to LIMIT.  Register

  127288. ** iOffset+1 is initialized to LIMIT+OFFSET.

  127289. **

  127290. ** Only if pLimit->pLeft!=0 do the limit registers get

  127291. ** redefined.  The UNION ALL operator uses this property to force

  127292. ** the reuse of the same limit and offset registers across multiple

  127293. ** SELECT statements.

  127294. */

  127295. static void computeLimitRegisters(Parse *pParse, Select *p, int iBreak){

  127296.   Vdbe *v = 0;

  127297.   int iLimit = 0;

  127298.   int iOffset;

  127299.   int n;

  127300.   Expr *pLimit = p->pLimit;

  127301. 

  127302.   if( p->iLimit ) return;

  127303. 

  127304.   /* 

  127305.   ** "LIMIT -1" always shows all rows.  There is some

  127306.   ** controversy about what the correct behavior should be.

  127307.   ** The current implementation interprets "LIMIT 0" to mean

  127308.   ** no rows.

  127309.   */

  127310.   if( pLimit ){

  127311.     assert( pLimit->op==TK_LIMIT );

  127312.     assert( pLimit->pLeft!=0 );

  127313.     p->iLimit = iLimit = ++pParse->nMem;

  127314.     v = sqlite3GetVdbe(pParse);

  127315.     assert( v!=0 );

  127316.     if( sqlite3ExprIsInteger(pLimit->pLeft, &n) ){

  127317.       sqlite3VdbeAddOp2(v, OP_Integer, n, iLimit);

  127318.       VdbeComment((v, "LIMIT counter"));

  127319.       if( n==0 ){

  127320.         sqlite3VdbeGoto(v, iBreak);

  127321.       }else if( n>=0 && p->nSelectRow>sqlite3LogEst((u64)n) ){

  127322.         p->nSelectRow = sqlite3LogEst((u64)n);

  127323.         p->selFlags |= SF_FixedLimit;

  127324.       }

  127325.     }else{

  127326.       sqlite3ExprCode(pParse, pLimit->pLeft, iLimit);

  127327.       sqlite3VdbeAddOp1(v, OP_MustBeInt, iLimit); VdbeCoverage(v);

  127328.       VdbeComment((v, "LIMIT counter"));

  127329.       sqlite3VdbeAddOp2(v, OP_IfNot, iLimit, iBreak); VdbeCoverage(v);

  127330.     }

  127331.     if( pLimit->pRight ){

  127332.       p->iOffset = iOffset = ++pParse->nMem;

  127333.       pParse->nMem++;   /* Allocate an extra register for limit+offset */

  127334.       sqlite3ExprCode(pParse, pLimit->pRight, iOffset);

  127335.       sqlite3VdbeAddOp1(v, OP_MustBeInt, iOffset); VdbeCoverage(v);

  127336.       VdbeComment((v, "OFFSET counter"));

  127337.       sqlite3VdbeAddOp3(v, OP_OffsetLimit, iLimit, iOffset+1, iOffset);

  127338.       VdbeComment((v, "LIMIT+OFFSET"));

  127339.     }

  127340.   }

  127341. }

  127342. 

  127343. #ifndef SQLITE_OMIT_COMPOUND_SELECT

  127344. /*

  127345. ** Return the appropriate collating sequence for the iCol-th column of

  127346. ** the result set for the compound-select statement "p".  Return NULL if

  127347. ** the column has no default collating sequence.

  127348. **

  127349. ** The collating sequence for the compound select is taken from the

  127350. ** left-most term of the select that has a collating sequence.

  127351. */

  127352. static CollSeq *multiSelectCollSeq(Parse *pParse, Select *p, int iCol){

  127353.   CollSeq *pRet;

  127354.   if( p->pPrior ){

  127355.     pRet = multiSelectCollSeq(pParse, p->pPrior, iCol);

  127356.   }else{

  127357.     pRet = 0;

  127358.   }

  127359.   assert( iCol>=0 );

  127360.   /* iCol must be less than p->pEList->nExpr.  Otherwise an error would

  127361.   ** have been thrown during name resolution and we would not have gotten

  127362.   ** this far */

  127363.   if( pRet==0 && ALWAYS(iCol<p->pEList->nExpr) ){

  127364.     pRet = sqlite3ExprCollSeq(pParse, p->pEList->a[iCol].pExpr);

  127365.   }

  127366.   return pRet;

  127367. }

  127368. 

  127369. /*

  127370. ** The select statement passed as the second parameter is a compound SELECT

  127371. ** with an ORDER BY clause. This function allocates and returns a KeyInfo

  127372. ** structure suitable for implementing the ORDER BY.

  127373. **

  127374. ** Space to hold the KeyInfo structure is obtained from malloc. The calling

  127375. ** function is responsible for ensuring that this structure is eventually

  127376. ** freed.

  127377. */

  127378. static KeyInfo *multiSelectOrderByKeyInfo(Parse *pParse, Select *p, int nExtra){

  127379.   ExprList *pOrderBy = p->pOrderBy;

  127380.   int nOrderBy = p->pOrderBy->nExpr;

  127381.   sqlite3 *db = pParse->db;

  127382.   KeyInfo *pRet = sqlite3KeyInfoAlloc(db, nOrderBy+nExtra, 1);

  127383.   if( pRet ){

  127384.     int i;

  127385.     for(i=0; i<nOrderBy; i++){

  127386.       struct ExprList_item *pItem = &pOrderBy->a[i];

  127387.       Expr *pTerm = pItem->pExpr;

  127388.       CollSeq *pColl;

  127389. 

  127390.       if( pTerm->flags & EP_Collate ){

  127391.         pColl = sqlite3ExprCollSeq(pParse, pTerm);

  127392.       }else{

  127393.         pColl = multiSelectCollSeq(pParse, p, pItem->u.x.iOrderByCol-1);

  127394.         if( pColl==0 ) pColl = db->pDfltColl;

  127395.         pOrderBy->a[i].pExpr =

  127396.           sqlite3ExprAddCollateString(pParse, pTerm, pColl->zName);

  127397.       }

  127398.       assert( sqlite3KeyInfoIsWriteable(pRet) );

  127399.       pRet->aColl[i] = pColl;

  127400.       pRet->aSortOrder[i] = pOrderBy->a[i].sortOrder;

  127401.     }

  127402.   }

  127403. 

  127404.   return pRet;

  127405. }

  127406. 

  127407. #ifndef SQLITE_OMIT_CTE

  127408. /*

  127409. ** This routine generates VDBE code to compute the content of a WITH RECURSIVE

  127410. ** query of the form:

  127411. **

  127412. **   <recursive-table> AS (<setup-query> UNION [ALL] <recursive-query>)

  127413. **                         \___________/             \_______________/

  127414. **                           p->pPrior                      p

  127415. **

  127416. **

  127417. ** There is exactly one reference to the recursive-table in the FROM clause

  127418. ** of recursive-query, marked with the SrcList->a[].fg.isRecursive flag.

  127419. **

  127420. ** The setup-query runs once to generate an initial set of rows that go

  127421. ** into a Queue table.  Rows are extracted from the Queue table one by

  127422. ** one.  Each row extracted from Queue is output to pDest.  Then the single

  127423. ** extracted row (now in the iCurrent table) becomes the content of the

  127424. ** recursive-table for a recursive-query run.  The output of the recursive-query

  127425. ** is added back into the Queue table.  Then another row is extracted from Queue

  127426. ** and the iteration continues until the Queue table is empty.

  127427. **

  127428. ** If the compound query operator is UNION then no duplicate rows are ever

  127429. ** inserted into the Queue table.  The iDistinct table keeps a copy of all rows

  127430. ** that have ever been inserted into Queue and causes duplicates to be

  127431. ** discarded.  If the operator is UNION ALL, then duplicates are allowed.

  127432. ** 

  127433. ** If the query has an ORDER BY, then entries in the Queue table are kept in

  127434. ** ORDER BY order and the first entry is extracted for each cycle.  Without

  127435. ** an ORDER BY, the Queue table is just a FIFO.

  127436. **

  127437. ** If a LIMIT clause is provided, then the iteration stops after LIMIT rows

  127438. ** have been output to pDest.  A LIMIT of zero means to output no rows and a

  127439. ** negative LIMIT means to output all rows.  If there is also an OFFSET clause

  127440. ** with a positive value, then the first OFFSET outputs are discarded rather

  127441. ** than being sent to pDest.  The LIMIT count does not begin until after OFFSET

  127442. ** rows have been skipped.

  127443. */

  127444. static void generateWithRecursiveQuery(

  127445.   Parse *pParse,        /* Parsing context */

  127446.   Select *p,            /* The recursive SELECT to be coded */

  127447.   SelectDest *pDest     /* What to do with query results */

  127448. ){

  127449.   SrcList *pSrc = p->pSrc;      /* The FROM clause of the recursive query */

  127450.   int nCol = p->pEList->nExpr;  /* Number of columns in the recursive table */

  127451.   Vdbe *v = pParse->pVdbe;      /* The prepared statement under construction */

  127452.   Select *pSetup = p->pPrior;   /* The setup query */

  127453.   int addrTop;                  /* Top of the loop */

  127454.   int addrCont, addrBreak;      /* CONTINUE and BREAK addresses */

  127455.   int iCurrent = 0;             /* The Current table */

  127456.   int regCurrent;               /* Register holding Current table */

  127457.   int iQueue;                   /* The Queue table */

  127458.   int iDistinct = 0;            /* To ensure unique results if UNION */

  127459.   int eDest = SRT_Fifo;         /* How to write to Queue */

  127460.   SelectDest destQueue;         /* SelectDest targetting the Queue table */

  127461.   int i;                        /* Loop counter */

  127462.   int rc;                       /* Result code */

  127463.   ExprList *pOrderBy;           /* The ORDER BY clause */

  127464.   Expr *pLimit;                 /* Saved LIMIT and OFFSET */

  127465.   int regLimit, regOffset;      /* Registers used by LIMIT and OFFSET */

  127466. 

  127467. #ifndef SQLITE_OMIT_WINDOWFUNC

  127468.   if( p->pWin ){

  127469.     sqlite3ErrorMsg(pParse, "cannot use window functions in recursive queries");

  127470.     return;

  127471.   }

  127472. #endif

  127473. 

  127474.   /* Obtain authorization to do a recursive query */

  127475.   if( sqlite3AuthCheck(pParse, SQLITE_RECURSIVE, 0, 0, 0) ) return;

  127476. 

  127477.   /* Process the LIMIT and OFFSET clauses, if they exist */

  127478.   addrBreak = sqlite3VdbeMakeLabel(pParse);

  127479.   p->nSelectRow = 320;  /* 4 billion rows */

  127480.   computeLimitRegisters(pParse, p, addrBreak);

  127481.   pLimit = p->pLimit;

  127482.   regLimit = p->iLimit;

  127483.   regOffset = p->iOffset;

  127484.   p->pLimit = 0;

  127485.   p->iLimit = p->iOffset = 0;

  127486.   pOrderBy = p->pOrderBy;

  127487. 

  127488.   /* Locate the cursor number of the Current table */

  127489.   for(i=0; ALWAYS(i<pSrc->nSrc); i++){

  127490.     if( pSrc->a[i].fg.isRecursive ){

  127491.       iCurrent = pSrc->a[i].iCursor;

  127492.       break;

  127493.     }

  127494.   }

  127495. 

  127496.   /* Allocate cursors numbers for Queue and Distinct.  The cursor number for

  127497.   ** the Distinct table must be exactly one greater than Queue in order

  127498.   ** for the SRT_DistFifo and SRT_DistQueue destinations to work. */

  127499.   iQueue = pParse->nTab++;

  127500.   if( p->op==TK_UNION ){

  127501.     eDest = pOrderBy ? SRT_DistQueue : SRT_DistFifo;

  127502.     iDistinct = pParse->nTab++;

  127503.   }else{

  127504.     eDest = pOrderBy ? SRT_Queue : SRT_Fifo;

  127505.   }

  127506.   sqlite3SelectDestInit(&destQueue, eDest, iQueue);

  127507. 

  127508.   /* Allocate cursors for Current, Queue, and Distinct. */

  127509.   regCurrent = ++pParse->nMem;

  127510.   sqlite3VdbeAddOp3(v, OP_OpenPseudo, iCurrent, regCurrent, nCol);

  127511.   if( pOrderBy ){

  127512.     KeyInfo *pKeyInfo = multiSelectOrderByKeyInfo(pParse, p, 1);

  127513.     sqlite3VdbeAddOp4(v, OP_OpenEphemeral, iQueue, pOrderBy->nExpr+2, 0,

  127514.                       (char*)pKeyInfo, P4_KEYINFO);

  127515.     destQueue.pOrderBy = pOrderBy;

  127516.   }else{

  127517.     sqlite3VdbeAddOp2(v, OP_OpenEphemeral, iQueue, nCol);

  127518.   }

  127519.   VdbeComment((v, "Queue table"));

  127520.   if( iDistinct ){

  127521.     p->addrOpenEphm[0] = sqlite3VdbeAddOp2(v, OP_OpenEphemeral, iDistinct, 0);

  127522.     p->selFlags |= SF_UsesEphemeral;

  127523.   }

  127524. 

  127525.   /* Detach the ORDER BY clause from the compound SELECT */

  127526.   p->pOrderBy = 0;

  127527. 

  127528.   /* Store the results of the setup-query in Queue. */

  127529.   pSetup->pNext = 0;

  127530.   ExplainQueryPlan((pParse, 1, "SETUP"));

  127531.   rc = sqlite3Select(pParse, pSetup, &destQueue);

  127532.   pSetup->pNext = p;

  127533.   if( rc ) goto end_of_recursive_query;

  127534. 

  127535.   /* Find the next row in the Queue and output that row */

  127536.   addrTop = sqlite3VdbeAddOp2(v, OP_Rewind, iQueue, addrBreak); VdbeCoverage(v);

  127537. 

  127538.   /* Transfer the next row in Queue over to Current */

  127539.   sqlite3VdbeAddOp1(v, OP_NullRow, iCurrent); /* To reset column cache */

  127540.   if( pOrderBy ){

  127541.     sqlite3VdbeAddOp3(v, OP_Column, iQueue, pOrderBy->nExpr+1, regCurrent);

  127542.   }else{

  127543.     sqlite3VdbeAddOp2(v, OP_RowData, iQueue, regCurrent);

  127544.   }

  127545.   sqlite3VdbeAddOp1(v, OP_Delete, iQueue);

  127546. 

  127547.   /* Output the single row in Current */

  127548.   addrCont = sqlite3VdbeMakeLabel(pParse);

  127549.   codeOffset(v, regOffset, addrCont);

  127550.   selectInnerLoop(pParse, p, iCurrent,

  127551.       0, 0, pDest, addrCont, addrBreak);

  127552.   if( regLimit ){

  127553.     sqlite3VdbeAddOp2(v, OP_DecrJumpZero, regLimit, addrBreak);

  127554.     VdbeCoverage(v);

  127555.   }

  127556.   sqlite3VdbeResolveLabel(v, addrCont);

  127557. 

  127558.   /* Execute the recursive SELECT taking the single row in Current as

  127559.   ** the value for the recursive-table. Store the results in the Queue.

  127560.   */

  127561.   if( p->selFlags & SF_Aggregate ){

  127562.     sqlite3ErrorMsg(pParse, "recursive aggregate queries not supported");

  127563.   }else{

  127564.     p->pPrior = 0;

  127565.     ExplainQueryPlan((pParse, 1, "RECURSIVE STEP"));

  127566.     sqlite3Select(pParse, p, &destQueue);

  127567.     assert( p->pPrior==0 );

  127568.     p->pPrior = pSetup;

  127569.   }

  127570. 

  127571.   /* Keep running the loop until the Queue is empty */

  127572.   sqlite3VdbeGoto(v, addrTop);

  127573.   sqlite3VdbeResolveLabel(v, addrBreak);

  127574. 

  127575. end_of_recursive_query:

  127576.   sqlite3ExprListDelete(pParse->db, p->pOrderBy);

  127577.   p->pOrderBy = pOrderBy;

  127578.   p->pLimit = pLimit;

  127579.   return;

  127580. }

  127581. #endif /* SQLITE_OMIT_CTE */

  127582. 

  127583. /* Forward references */

  127584. static int multiSelectOrderBy(

  127585.   Parse *pParse,        /* Parsing context */

  127586.   Select *p,            /* The right-most of SELECTs to be coded */

  127587.   SelectDest *pDest     /* What to do with query results */

  127588. );

  127589. 

  127590. /*

  127591. ** Handle the special case of a compound-select that originates from a

  127592. ** VALUES clause.  By handling this as a special case, we avoid deep

  127593. ** recursion, and thus do not need to enforce the SQLITE_LIMIT_COMPOUND_SELECT

  127594. ** on a VALUES clause.

  127595. **

  127596. ** Because the Select object originates from a VALUES clause:

  127597. **   (1) There is no LIMIT or OFFSET or else there is a LIMIT of exactly 1

  127598. **   (2) All terms are UNION ALL

  127599. **   (3) There is no ORDER BY clause

  127600. **

  127601. ** The "LIMIT of exactly 1" case of condition (1) comes about when a VALUES

  127602. ** clause occurs within scalar expression (ex: "SELECT (VALUES(1),(2),(3))").

  127603. ** The sqlite3CodeSubselect will have added the LIMIT 1 clause in tht case.

  127604. ** Since the limit is exactly 1, we only need to evalutes the left-most VALUES.

  127605. */

  127606. static int multiSelectValues(

  127607.   Parse *pParse,        /* Parsing context */

  127608.   Select *p,            /* The right-most of SELECTs to be coded */

  127609.   SelectDest *pDest     /* What to do with query results */

  127610. ){

  127611.   int nRow = 1;

  127612.   int rc = 0;

  127613.   int bShowAll = p->pLimit==0;

  127614.   assert( p->selFlags & SF_MultiValue );

  127615.   do{

  127616.     assert( p->selFlags & SF_Values );

  127617.     assert( p->op==TK_ALL || (p->op==TK_SELECT && p->pPrior==0) );

  127618.     assert( p->pNext==0 || p->pEList->nExpr==p->pNext->pEList->nExpr );

  127619.     if( p->pPrior==0 ) break;

  127620.     assert( p->pPrior->pNext==p );

  127621.     p = p->pPrior;

  127622.     nRow += bShowAll;

  127623.   }while(1);

  127624.   ExplainQueryPlan((pParse, 0, "SCAN %d CONSTANT ROW%s", nRow,

  127625.                     nRow==1 ? "" : "S"));

  127626.   while( p ){

  127627.     selectInnerLoop(pParse, p, -1, 0, 0, pDest, 1, 1);

  127628.     if( !bShowAll ) break;

  127629.     p->nSelectRow = nRow;

  127630.     p = p->pNext;

  127631.   }

  127632.   return rc;

  127633. }

  127634. 

  127635. /*

  127636. ** This routine is called to process a compound query form from

  127637. ** two or more separate queries using UNION, UNION ALL, EXCEPT, or

  127638. ** INTERSECT

  127639. **

  127640. ** "p" points to the right-most of the two queries.  the query on the

  127641. ** left is p->pPrior.  The left query could also be a compound query

  127642. ** in which case this routine will be called recursively. 

  127643. **

  127644. ** The results of the total query are to be written into a destination

  127645. ** of type eDest with parameter iParm.

  127646. **

  127647. ** Example 1:  Consider a three-way compound SQL statement.

  127648. **

  127649. **     SELECT a FROM t1 UNION SELECT b FROM t2 UNION SELECT c FROM t3

  127650. **

  127651. ** This statement is parsed up as follows:

  127652. **

  127653. **     SELECT c FROM t3

  127654. **      |

  127655. **      `----->  SELECT b FROM t2

  127656. **                |

  127657. **                `------>  SELECT a FROM t1

  127658. **

  127659. ** The arrows in the diagram above represent the Select.pPrior pointer.

  127660. ** So if this routine is called with p equal to the t3 query, then

  127661. ** pPrior will be the t2 query.  p->op will be TK_UNION in this case.

  127662. **

  127663. ** Notice that because of the way SQLite parses compound SELECTs, the

  127664. ** individual selects always group from left to right.

  127665. */

  127666. static int multiSelect(

  127667.   Parse *pParse,        /* Parsing context */

  127668.   Select *p,            /* The right-most of SELECTs to be coded */

  127669.   SelectDest *pDest     /* What to do with query results */

  127670. ){

  127671.   int rc = SQLITE_OK;   /* Success code from a subroutine */

  127672.   Select *pPrior;       /* Another SELECT immediately to our left */

  127673.   Vdbe *v;              /* Generate code to this VDBE */

  127674.   SelectDest dest;      /* Alternative data destination */

  127675.   Select *pDelete = 0;  /* Chain of simple selects to delete */

  127676.   sqlite3 *db;          /* Database connection */

  127677. 

  127678.   /* Make sure there is no ORDER BY or LIMIT clause on prior SELECTs.  Only

  127679.   ** the last (right-most) SELECT in the series may have an ORDER BY or LIMIT.

  127680.   */

  127681.   assert( p && p->pPrior );  /* Calling function guarantees this much */

  127682.   assert( (p->selFlags & SF_Recursive)==0 || p->op==TK_ALL || p->op==TK_UNION );

  127683.   assert( p->selFlags & SF_Compound );

  127684.   db = pParse->db;

  127685.   pPrior = p->pPrior;

  127686.   dest = *pDest;

  127687.   if( pPrior->pOrderBy || pPrior->pLimit ){

  127688.     sqlite3ErrorMsg(pParse,"%s clause should come after %s not before",

  127689.       pPrior->pOrderBy!=0 ? "ORDER BY" : "LIMIT", selectOpName(p->op));

  127690.     rc = 1;

  127691.     goto multi_select_end;

  127692.   }

  127693. 

  127694.   v = sqlite3GetVdbe(pParse);

  127695.   assert( v!=0 );  /* The VDBE already created by calling function */

  127696. 

  127697.   /* Create the destination temporary table if necessary

  127698.   */

  127699.   if( dest.eDest==SRT_EphemTab ){

  127700.     assert( p->pEList );

  127701.     sqlite3VdbeAddOp2(v, OP_OpenEphemeral, dest.iSDParm, p->pEList->nExpr);

  127702.     dest.eDest = SRT_Table;

  127703.   }

  127704. 

  127705.   /* Special handling for a compound-select that originates as a VALUES clause.

  127706.   */

  127707.   if( p->selFlags & SF_MultiValue ){

  127708.     rc = multiSelectValues(pParse, p, &dest);

  127709.     goto multi_select_end;

  127710.   }

  127711. 

  127712.   /* Make sure all SELECTs in the statement have the same number of elements

  127713.   ** in their result sets.

  127714.   */

  127715.   assert( p->pEList && pPrior->pEList );

  127716.   assert( p->pEList->nExpr==pPrior->pEList->nExpr );

  127717. 

  127718. #ifndef SQLITE_OMIT_CTE

  127719.   if( p->selFlags & SF_Recursive ){

  127720.     generateWithRecursiveQuery(pParse, p, &dest);

  127721.   }else

  127722. #endif

  127723. 

  127724.   /* Compound SELECTs that have an ORDER BY clause are handled separately.

  127725.   */

  127726.   if( p->pOrderBy ){

  127727.     return multiSelectOrderBy(pParse, p, pDest);

  127728.   }else{

  127729. 

  127730. #ifndef SQLITE_OMIT_EXPLAIN

  127731.     if( pPrior->pPrior==0 ){

  127732.       ExplainQueryPlan((pParse, 1, "COMPOUND QUERY"));

  127733.       ExplainQueryPlan((pParse, 1, "LEFT-MOST SUBQUERY"));

  127734.     }

  127735. #endif

  127736. 

  127737.     /* Generate code for the left and right SELECT statements.

  127738.     */

  127739.     switch( p->op ){

  127740.       case TK_ALL: {

  127741.         int addr = 0;

  127742.         int nLimit;

  127743.         assert( !pPrior->pLimit );

  127744.         pPrior->iLimit = p->iLimit;

  127745.         pPrior->iOffset = p->iOffset;

  127746.         pPrior->pLimit = p->pLimit;

  127747.         rc = sqlite3Select(pParse, pPrior, &dest);

  127748.         p->pLimit = 0;

  127749.         if( rc ){

  127750.           goto multi_select_end;

  127751.         }

  127752.         p->pPrior = 0;

  127753.         p->iLimit = pPrior->iLimit;

  127754.         p->iOffset = pPrior->iOffset;

  127755.         if( p->iLimit ){

  127756.           addr = sqlite3VdbeAddOp1(v, OP_IfNot, p->iLimit); VdbeCoverage(v);

  127757.           VdbeComment((v, "Jump ahead if LIMIT reached"));

  127758.           if( p->iOffset ){

  127759.             sqlite3VdbeAddOp3(v, OP_OffsetLimit,

  127760.                               p->iLimit, p->iOffset+1, p->iOffset);

  127761.           }

  127762.         }

  127763.         ExplainQueryPlan((pParse, 1, "UNION ALL"));

  127764.         rc = sqlite3Select(pParse, p, &dest);

  127765.         testcase( rc!=SQLITE_OK );

  127766.         pDelete = p->pPrior;

  127767.         p->pPrior = pPrior;

  127768.         p->nSelectRow = sqlite3LogEstAdd(p->nSelectRow, pPrior->nSelectRow);

  127769.         if( pPrior->pLimit

  127770.          && sqlite3ExprIsInteger(pPrior->pLimit->pLeft, &nLimit)

  127771.          && nLimit>0 && p->nSelectRow > sqlite3LogEst((u64)nLimit) 

  127772.         ){

  127773.           p->nSelectRow = sqlite3LogEst((u64)nLimit);

  127774.         }

  127775.         if( addr ){

  127776.           sqlite3VdbeJumpHere(v, addr);

  127777.         }

  127778.         break;

  127779.       }

  127780.       case TK_EXCEPT:

  127781.       case TK_UNION: {

  127782.         int unionTab;    /* Cursor number of the temp table holding result */

  127783.         u8 op = 0;       /* One of the SRT_ operations to apply to self */

  127784.         int priorOp;     /* The SRT_ operation to apply to prior selects */

  127785.         Expr *pLimit;    /* Saved values of p->nLimit  */

  127786.         int addr;

  127787.         SelectDest uniondest;

  127788.   

  127789.         testcase( p->op==TK_EXCEPT );

  127790.         testcase( p->op==TK_UNION );

  127791.         priorOp = SRT_Union;

  127792.         if( dest.eDest==priorOp ){

  127793.           /* We can reuse a temporary table generated by a SELECT to our

  127794.           ** right.

  127795.           */

  127796.           assert( p->pLimit==0 );      /* Not allowed on leftward elements */

  127797.           unionTab = dest.iSDParm;

  127798.         }else{

  127799.           /* We will need to create our own temporary table to hold the

  127800.           ** intermediate results.

  127801.           */

  127802.           unionTab = pParse->nTab++;

  127803.           assert( p->pOrderBy==0 );

  127804.           addr = sqlite3VdbeAddOp2(v, OP_OpenEphemeral, unionTab, 0);

  127805.           assert( p->addrOpenEphm[0] == -1 );

  127806.           p->addrOpenEphm[0] = addr;

  127807.           findRightmost(p)->selFlags |= SF_UsesEphemeral;

  127808.           assert( p->pEList );

  127809.         }

  127810.   

  127811.         /* Code the SELECT statements to our left

  127812.         */

  127813.         assert( !pPrior->pOrderBy );

  127814.         sqlite3SelectDestInit(&uniondest, priorOp, unionTab);

  127815.         rc = sqlite3Select(pParse, pPrior, &uniondest);

  127816.         if( rc ){

  127817.           goto multi_select_end;

  127818.         }

  127819.   

  127820.         /* Code the current SELECT statement

  127821.         */

  127822.         if( p->op==TK_EXCEPT ){

  127823.           op = SRT_Except;

  127824.         }else{

  127825.           assert( p->op==TK_UNION );

  127826.           op = SRT_Union;

  127827.         }

  127828.         p->pPrior = 0;

  127829.         pLimit = p->pLimit;

  127830.         p->pLimit = 0;

  127831.         uniondest.eDest = op;

  127832.         ExplainQueryPlan((pParse, 1, "%s USING TEMP B-TREE",

  127833.                           selectOpName(p->op)));

  127834.         rc = sqlite3Select(pParse, p, &uniondest);

  127835.         testcase( rc!=SQLITE_OK );

  127836.         /* Query flattening in sqlite3Select() might refill p->pOrderBy.

  127837.         ** Be sure to delete p->pOrderBy, therefore, to avoid a memory leak. */

  127838.         sqlite3ExprListDelete(db, p->pOrderBy);

  127839.         pDelete = p->pPrior;

  127840.         p->pPrior = pPrior;

  127841.         p->pOrderBy = 0;

  127842.         if( p->op==TK_UNION ){

  127843.           p->nSelectRow = sqlite3LogEstAdd(p->nSelectRow, pPrior->nSelectRow);

  127844.         }

  127845.         sqlite3ExprDelete(db, p->pLimit);

  127846.         p->pLimit = pLimit;

  127847.         p->iLimit = 0;

  127848.         p->iOffset = 0;

  127849.   

  127850.         /* Convert the data in the temporary table into whatever form

  127851.         ** it is that we currently need.

  127852.         */

  127853.         assert( unionTab==dest.iSDParm || dest.eDest!=priorOp );

  127854.         if( dest.eDest!=priorOp ){

  127855.           int iCont, iBreak, iStart;

  127856.           assert( p->pEList );

  127857.           iBreak = sqlite3VdbeMakeLabel(pParse);

  127858.           iCont = sqlite3VdbeMakeLabel(pParse);

  127859.           computeLimitRegisters(pParse, p, iBreak);

  127860.           sqlite3VdbeAddOp2(v, OP_Rewind, unionTab, iBreak); VdbeCoverage(v);

  127861.           iStart = sqlite3VdbeCurrentAddr(v);

  127862.           selectInnerLoop(pParse, p, unionTab,

  127863.                           0, 0, &dest, iCont, iBreak);

  127864.           sqlite3VdbeResolveLabel(v, iCont);

  127865.           sqlite3VdbeAddOp2(v, OP_Next, unionTab, iStart); VdbeCoverage(v);

  127866.           sqlite3VdbeResolveLabel(v, iBreak);

  127867.           sqlite3VdbeAddOp2(v, OP_Close, unionTab, 0);

  127868.         }

  127869.         break;

  127870.       }

  127871.       default: assert( p->op==TK_INTERSECT ); {

  127872.         int tab1, tab2;

  127873.         int iCont, iBreak, iStart;

  127874.         Expr *pLimit;

  127875.         int addr;

  127876.         SelectDest intersectdest;

  127877.         int r1;

  127878.   

  127879.         /* INTERSECT is different from the others since it requires

  127880.         ** two temporary tables.  Hence it has its own case.  Begin

  127881.         ** by allocating the tables we will need.

  127882.         */

  127883.         tab1 = pParse->nTab++;

  127884.         tab2 = pParse->nTab++;

  127885.         assert( p->pOrderBy==0 );

  127886.   

  127887.         addr = sqlite3VdbeAddOp2(v, OP_OpenEphemeral, tab1, 0);

  127888.         assert( p->addrOpenEphm[0] == -1 );

  127889.         p->addrOpenEphm[0] = addr;

  127890.         findRightmost(p)->selFlags |= SF_UsesEphemeral;

  127891.         assert( p->pEList );

  127892.   

  127893.         /* Code the SELECTs to our left into temporary table "tab1".

  127894.         */

  127895.         sqlite3SelectDestInit(&intersectdest, SRT_Union, tab1);

  127896.         rc = sqlite3Select(pParse, pPrior, &intersectdest);

  127897.         if( rc ){

  127898.           goto multi_select_end;

  127899.         }

  127900.   

  127901.         /* Code the current SELECT into temporary table "tab2"

  127902.         */

  127903.         addr = sqlite3VdbeAddOp2(v, OP_OpenEphemeral, tab2, 0);

  127904.         assert( p->addrOpenEphm[1] == -1 );

  127905.         p->addrOpenEphm[1] = addr;

  127906.         p->pPrior = 0;

  127907.         pLimit = p->pLimit;

  127908.         p->pLimit = 0;

  127909.         intersectdest.iSDParm = tab2;

  127910.         ExplainQueryPlan((pParse, 1, "%s USING TEMP B-TREE",

  127911.                           selectOpName(p->op)));

  127912.         rc = sqlite3Select(pParse, p, &intersectdest);

  127913.         testcase( rc!=SQLITE_OK );

  127914.         pDelete = p->pPrior;

  127915.         p->pPrior = pPrior;

  127916.         if( p->nSelectRow>pPrior->nSelectRow ){

  127917.           p->nSelectRow = pPrior->nSelectRow;

  127918.         }

  127919.         sqlite3ExprDelete(db, p->pLimit);

  127920.         p->pLimit = pLimit;

  127921.   

  127922.         /* Generate code to take the intersection of the two temporary

  127923.         ** tables.

  127924.         */

  127925.         assert( p->pEList );

  127926.         iBreak = sqlite3VdbeMakeLabel(pParse);

  127927.         iCont = sqlite3VdbeMakeLabel(pParse);

  127928.         computeLimitRegisters(pParse, p, iBreak);

  127929.         sqlite3VdbeAddOp2(v, OP_Rewind, tab1, iBreak); VdbeCoverage(v);

  127930.         r1 = sqlite3GetTempReg(pParse);

  127931.         iStart = sqlite3VdbeAddOp2(v, OP_RowData, tab1, r1);

  127932.         sqlite3VdbeAddOp4Int(v, OP_NotFound, tab2, iCont, r1, 0);

  127933.         VdbeCoverage(v);

  127934.         sqlite3ReleaseTempReg(pParse, r1);

  127935.         selectInnerLoop(pParse, p, tab1,

  127936.                         0, 0, &dest, iCont, iBreak);

  127937.         sqlite3VdbeResolveLabel(v, iCont);

  127938.         sqlite3VdbeAddOp2(v, OP_Next, tab1, iStart); VdbeCoverage(v);

  127939.         sqlite3VdbeResolveLabel(v, iBreak);

  127940.         sqlite3VdbeAddOp2(v, OP_Close, tab2, 0);

  127941.         sqlite3VdbeAddOp2(v, OP_Close, tab1, 0);

  127942.         break;

  127943.       }

  127944.     }

  127945.   

  127946.   #ifndef SQLITE_OMIT_EXPLAIN

  127947.     if( p->pNext==0 ){

  127948.       ExplainQueryPlanPop(pParse);

  127949.     }

  127950.   #endif

  127951.   }

  127952.   

  127953.   /* Compute collating sequences used by 

  127954.   ** temporary tables needed to implement the compound select.

  127955.   ** Attach the KeyInfo structure to all temporary tables.

  127956.   **

  127957.   ** This section is run by the right-most SELECT statement only.

  127958.   ** SELECT statements to the left always skip this part.  The right-most

  127959.   ** SELECT might also skip this part if it has no ORDER BY clause and

  127960.   ** no temp tables are required.

  127961.   */

  127962.   if( p->selFlags & SF_UsesEphemeral ){

  127963.     int i;                        /* Loop counter */

  127964.     KeyInfo *pKeyInfo;            /* Collating sequence for the result set */

  127965.     Select *pLoop;                /* For looping through SELECT statements */

  127966.     CollSeq **apColl;             /* For looping through pKeyInfo->aColl[] */

  127967.     int nCol;                     /* Number of columns in result set */

  127968. 

  127969.     assert( p->pNext==0 );

  127970.     nCol = p->pEList->nExpr;

  127971.     pKeyInfo = sqlite3KeyInfoAlloc(db, nCol, 1);

  127972.     if( !pKeyInfo ){

  127973.       rc = SQLITE_NOMEM_BKPT;

  127974.       goto multi_select_end;

  127975.     }

  127976.     for(i=0, apColl=pKeyInfo->aColl; i<nCol; i++, apColl++){

  127977.       *apColl = multiSelectCollSeq(pParse, p, i);

  127978.       if( 0==*apColl ){

  127979.         *apColl = db->pDfltColl;

  127980.       }

  127981.     }

  127982. 

  127983.     for(pLoop=p; pLoop; pLoop=pLoop->pPrior){

  127984.       for(i=0; i<2; i++){

  127985.         int addr = pLoop->addrOpenEphm[i];

  127986.         if( addr<0 ){

  127987.           /* If [0] is unused then [1] is also unused.  So we can

  127988.           ** always safely abort as soon as the first unused slot is found */

  127989.           assert( pLoop->addrOpenEphm[1]<0 );

  127990.           break;

  127991.         }

  127992.         sqlite3VdbeChangeP2(v, addr, nCol);

  127993.         sqlite3VdbeChangeP4(v, addr, (char*)sqlite3KeyInfoRef(pKeyInfo),

  127994.                             P4_KEYINFO);

  127995.         pLoop->addrOpenEphm[i] = -1;

  127996.       }

  127997.     }

  127998.     sqlite3KeyInfoUnref(pKeyInfo);

  127999.   }

  128000. 

  128001. multi_select_end:

  128002.   pDest->iSdst = dest.iSdst;

  128003.   pDest->nSdst = dest.nSdst;

  128004.   sqlite3SelectDelete(db, pDelete);

  128005.   return rc;

  128006. }

  128007. #endif /* SQLITE_OMIT_COMPOUND_SELECT */

  128008. 

  128009. /*

  128010. ** Error message for when two or more terms of a compound select have different

  128011. ** size result sets.

  128012. */

  128013. SQLITE_PRIVATE void sqlite3SelectWrongNumTermsError(Parse *pParse, Select *p){

  128014.   if( p->selFlags & SF_Values ){

  128015.     sqlite3ErrorMsg(pParse, "all VALUES must have the same number of terms");

  128016.   }else{

  128017.     sqlite3ErrorMsg(pParse, "SELECTs to the left and right of %s"

  128018.       " do not have the same number of result columns", selectOpName(p->op));

  128019.   }

  128020. }

  128021. 

  128022. /*

  128023. ** Code an output subroutine for a coroutine implementation of a

  128024. ** SELECT statment.

  128025. **

  128026. ** The data to be output is contained in pIn->iSdst.  There are

  128027. ** pIn->nSdst columns to be output.  pDest is where the output should

  128028. ** be sent.

  128029. **

  128030. ** regReturn is the number of the register holding the subroutine

  128031. ** return address.

  128032. **

  128033. ** If regPrev>0 then it is the first register in a vector that

  128034. ** records the previous output.  mem[regPrev] is a flag that is false

  128035. ** if there has been no previous output.  If regPrev>0 then code is

  128036. ** generated to suppress duplicates.  pKeyInfo is used for comparing

  128037. ** keys.

  128038. **

  128039. ** If the LIMIT found in p->iLimit is reached, jump immediately to

  128040. ** iBreak.

  128041. */

  128042. static int generateOutputSubroutine(

  128043.   Parse *pParse,          /* Parsing context */

  128044.   Select *p,              /* The SELECT statement */

  128045.   SelectDest *pIn,        /* Coroutine supplying data */

  128046.   SelectDest *pDest,      /* Where to send the data */

  128047.   int regReturn,          /* The return address register */

  128048.   int regPrev,            /* Previous result register.  No uniqueness if 0 */

  128049.   KeyInfo *pKeyInfo,      /* For comparing with previous entry */

  128050.   int iBreak              /* Jump here if we hit the LIMIT */

  128051. ){

  128052.   Vdbe *v = pParse->pVdbe;

  128053.   int iContinue;

  128054.   int addr;

  128055. 

  128056.   addr = sqlite3VdbeCurrentAddr(v);

  128057.   iContinue = sqlite3VdbeMakeLabel(pParse);

  128058. 

  128059.   /* Suppress duplicates for UNION, EXCEPT, and INTERSECT 

  128060.   */

  128061.   if( regPrev ){

  128062.     int addr1, addr2;

  128063.     addr1 = sqlite3VdbeAddOp1(v, OP_IfNot, regPrev); VdbeCoverage(v);

  128064.     addr2 = sqlite3VdbeAddOp4(v, OP_Compare, pIn->iSdst, regPrev+1, pIn->nSdst,

  128065.                               (char*)sqlite3KeyInfoRef(pKeyInfo), P4_KEYINFO);

  128066.     sqlite3VdbeAddOp3(v, OP_Jump, addr2+2, iContinue, addr2+2); VdbeCoverage(v);

  128067.     sqlite3VdbeJumpHere(v, addr1);

  128068.     sqlite3VdbeAddOp3(v, OP_Copy, pIn->iSdst, regPrev+1, pIn->nSdst-1);

  128069.     sqlite3VdbeAddOp2(v, OP_Integer, 1, regPrev);

  128070.   }

  128071.   if( pParse->db->mallocFailed ) return 0;

  128072. 

  128073.   /* Suppress the first OFFSET entries if there is an OFFSET clause

  128074.   */

  128075.   codeOffset(v, p->iOffset, iContinue);

  128076. 

  128077.   assert( pDest->eDest!=SRT_Exists );

  128078.   assert( pDest->eDest!=SRT_Table );

  128079.   switch( pDest->eDest ){

  128080.     /* Store the result as data using a unique key.

  128081.     */

  128082.     case SRT_EphemTab: {

  128083.       int r1 = sqlite3GetTempReg(pParse);

  128084.       int r2 = sqlite3GetTempReg(pParse);

  128085.       sqlite3VdbeAddOp3(v, OP_MakeRecord, pIn->iSdst, pIn->nSdst, r1);

  128086.       sqlite3VdbeAddOp2(v, OP_NewRowid, pDest->iSDParm, r2);

  128087.       sqlite3VdbeAddOp3(v, OP_Insert, pDest->iSDParm, r1, r2);

  128088.       sqlite3VdbeChangeP5(v, OPFLAG_APPEND);

  128089.       sqlite3ReleaseTempReg(pParse, r2);

  128090.       sqlite3ReleaseTempReg(pParse, r1);

  128091.       break;

  128092.     }

  128093. 

  128094. #ifndef SQLITE_OMIT_SUBQUERY

  128095.     /* If we are creating a set for an "expr IN (SELECT ...)".

  128096.     */

  128097.     case SRT_Set: {

  128098.       int r1;

  128099.       testcase( pIn->nSdst>1 );

  128100.       r1 = sqlite3GetTempReg(pParse);

  128101.       sqlite3VdbeAddOp4(v, OP_MakeRecord, pIn->iSdst, pIn->nSdst, 

  128102.           r1, pDest->zAffSdst, pIn->nSdst);

  128103.       sqlite3VdbeAddOp4Int(v, OP_IdxInsert, pDest->iSDParm, r1,

  128104.                            pIn->iSdst, pIn->nSdst);

  128105.       sqlite3ReleaseTempReg(pParse, r1);

  128106.       break;

  128107.     }

  128108. 

  128109.     /* If this is a scalar select that is part of an expression, then

  128110.     ** store the results in the appropriate memory cell and break out

  128111.     ** of the scan loop.

  128112.     */

  128113.     case SRT_Mem: {

  128114.       assert( pIn->nSdst==1 || pParse->nErr>0 );  testcase( pIn->nSdst!=1 );

  128115.       sqlite3ExprCodeMove(pParse, pIn->iSdst, pDest->iSDParm, 1);

  128116.       /* The LIMIT clause will jump out of the loop for us */

  128117.       break;

  128118.     }

  128119. #endif /* #ifndef SQLITE_OMIT_SUBQUERY */

  128120. 

  128121.     /* The results are stored in a sequence of registers

  128122.     ** starting at pDest->iSdst.  Then the co-routine yields.

  128123.     */

  128124.     case SRT_Coroutine: {

  128125.       if( pDest->iSdst==0 ){

  128126.         pDest->iSdst = sqlite3GetTempRange(pParse, pIn->nSdst);

  128127.         pDest->nSdst = pIn->nSdst;

  128128.       }

  128129.       sqlite3ExprCodeMove(pParse, pIn->iSdst, pDest->iSdst, pIn->nSdst);

  128130.       sqlite3VdbeAddOp1(v, OP_Yield, pDest->iSDParm);

  128131.       break;

  128132.     }

  128133. 

  128134.     /* If none of the above, then the result destination must be

  128135.     ** SRT_Output.  This routine is never called with any other

  128136.     ** destination other than the ones handled above or SRT_Output.

  128137.     **

  128138.     ** For SRT_Output, results are stored in a sequence of registers.  

  128139.     ** Then the OP_ResultRow opcode is used to cause sqlite3_step() to

  128140.     ** return the next row of result.

  128141.     */

  128142.     default: {

  128143.       assert( pDest->eDest==SRT_Output );

  128144.       sqlite3VdbeAddOp2(v, OP_ResultRow, pIn->iSdst, pIn->nSdst);

  128145.       break;

  128146.     }

  128147.   }

  128148. 

  128149.   /* Jump to the end of the loop if the LIMIT is reached.

  128150.   */

  128151.   if( p->iLimit ){

  128152.     sqlite3VdbeAddOp2(v, OP_DecrJumpZero, p->iLimit, iBreak); VdbeCoverage(v);

  128153.   }

  128154. 

  128155.   /* Generate the subroutine return

  128156.   */

  128157.   sqlite3VdbeResolveLabel(v, iContinue);

  128158.   sqlite3VdbeAddOp1(v, OP_Return, regReturn);

  128159. 

  128160.   return addr;

  128161. }

  128162. 

  128163. /*

  128164. ** Alternative compound select code generator for cases when there

  128165. ** is an ORDER BY clause.

  128166. **

  128167. ** We assume a query of the following form:

  128168. **

  128169. **      <selectA>  <operator>  <selectB>  ORDER BY <orderbylist>

  128170. **

  128171. ** <operator> is one of UNION ALL, UNION, EXCEPT, or INTERSECT.  The idea

  128172. ** is to code both <selectA> and <selectB> with the ORDER BY clause as

  128173. ** co-routines.  Then run the co-routines in parallel and merge the results

  128174. ** into the output.  In addition to the two coroutines (called selectA and

  128175. ** selectB) there are 7 subroutines:

  128176. **

  128177. **    outA:    Move the output of the selectA coroutine into the output

  128178. **             of the compound query.

  128179. **

  128180. **    outB:    Move the output of the selectB coroutine into the output

  128181. **             of the compound query.  (Only generated for UNION and

  128182. **             UNION ALL.  EXCEPT and INSERTSECT never output a row that

  128183. **             appears only in B.)

  128184. **

  128185. **    AltB:    Called when there is data from both coroutines and A<B.

  128186. **

  128187. **    AeqB:    Called when there is data from both coroutines and A==B.

  128188. **

  128189. **    AgtB:    Called when there is data from both coroutines and A>B.

  128190. **

  128191. **    EofA:    Called when data is exhausted from selectA.

  128192. **

  128193. **    EofB:    Called when data is exhausted from selectB.

  128194. **

  128195. ** The implementation of the latter five subroutines depend on which 

  128196. ** <operator> is used:

  128197. **

  128198. **

  128199. **             UNION ALL         UNION            EXCEPT          INTERSECT

  128200. **          -------------  -----------------  --------------  -----------------

  128201. **   AltB:   outA, nextA      outA, nextA       outA, nextA         nextA

  128202. **

  128203. **   AeqB:   outA, nextA         nextA             nextA         outA, nextA

  128204. **

  128205. **   AgtB:   outB, nextB      outB, nextB          nextB            nextB

  128206. **

  128207. **   EofA:   outB, nextB      outB, nextB          halt             halt

  128208. **

  128209. **   EofB:   outA, nextA      outA, nextA       outA, nextA         halt

  128210. **

  128211. ** In the AltB, AeqB, and AgtB subroutines, an EOF on A following nextA

  128212. ** causes an immediate jump to EofA and an EOF on B following nextB causes

  128213. ** an immediate jump to EofB.  Within EofA and EofB, and EOF on entry or

  128214. ** following nextX causes a jump to the end of the select processing.

  128215. **

  128216. ** Duplicate removal in the UNION, EXCEPT, and INTERSECT cases is handled

  128217. ** within the output subroutine.  The regPrev register set holds the previously

  128218. ** output value.  A comparison is made against this value and the output

  128219. ** is skipped if the next results would be the same as the previous.

  128220. **

  128221. ** The implementation plan is to implement the two coroutines and seven

  128222. ** subroutines first, then put the control logic at the bottom.  Like this:

  128223. **

  128224. **          goto Init

  128225. **     coA: coroutine for left query (A)

  128226. **     coB: coroutine for right query (B)

  128227. **    outA: output one row of A

  128228. **    outB: output one row of B (UNION and UNION ALL only)

  128229. **    EofA: ...

  128230. **    EofB: ...

  128231. **    AltB: ...

  128232. **    AeqB: ...

  128233. **    AgtB: ...

  128234. **    Init: initialize coroutine registers

  128235. **          yield coA

  128236. **          if eof(A) goto EofA

  128237. **          yield coB

  128238. **          if eof(B) goto EofB

  128239. **    Cmpr: Compare A, B

  128240. **          Jump AltB, AeqB, AgtB

  128241. **     End: ...

  128242. **

  128243. ** We call AltB, AeqB, AgtB, EofA, and EofB "subroutines" but they are not

  128244. ** actually called using Gosub and they do not Return.  EofA and EofB loop

  128245. ** until all data is exhausted then jump to the "end" labe.  AltB, AeqB,

  128246. ** and AgtB jump to either L2 or to one of EofA or EofB.

  128247. */

  128248. #ifndef SQLITE_OMIT_COMPOUND_SELECT

  128249. static int multiSelectOrderBy(

  128250.   Parse *pParse,        /* Parsing context */

  128251.   Select *p,            /* The right-most of SELECTs to be coded */

  128252.   SelectDest *pDest     /* What to do with query results */

  128253. ){

  128254.   int i, j;             /* Loop counters */

  128255.   Select *pPrior;       /* Another SELECT immediately to our left */

  128256.   Vdbe *v;              /* Generate code to this VDBE */

  128257.   SelectDest destA;     /* Destination for coroutine A */

  128258.   SelectDest destB;     /* Destination for coroutine B */

  128259.   int regAddrA;         /* Address register for select-A coroutine */

  128260.   int regAddrB;         /* Address register for select-B coroutine */

  128261.   int addrSelectA;      /* Address of the select-A coroutine */

  128262.   int addrSelectB;      /* Address of the select-B coroutine */

  128263.   int regOutA;          /* Address register for the output-A subroutine */

  128264.   int regOutB;          /* Address register for the output-B subroutine */

  128265.   int addrOutA;         /* Address of the output-A subroutine */

  128266.   int addrOutB = 0;     /* Address of the output-B subroutine */

  128267.   int addrEofA;         /* Address of the select-A-exhausted subroutine */

  128268.   int addrEofA_noB;     /* Alternate addrEofA if B is uninitialized */

  128269.   int addrEofB;         /* Address of the select-B-exhausted subroutine */

  128270.   int addrAltB;         /* Address of the A<B subroutine */

  128271.   int addrAeqB;         /* Address of the A==B subroutine */

  128272.   int addrAgtB;         /* Address of the A>B subroutine */

  128273.   int regLimitA;        /* Limit register for select-A */

  128274.   int regLimitB;        /* Limit register for select-A */

  128275.   int regPrev;          /* A range of registers to hold previous output */

  128276.   int savedLimit;       /* Saved value of p->iLimit */

  128277.   int savedOffset;      /* Saved value of p->iOffset */

  128278.   int labelCmpr;        /* Label for the start of the merge algorithm */

  128279.   int labelEnd;         /* Label for the end of the overall SELECT stmt */

  128280.   int addr1;            /* Jump instructions that get retargetted */

  128281.   int op;               /* One of TK_ALL, TK_UNION, TK_EXCEPT, TK_INTERSECT */

  128282.   KeyInfo *pKeyDup = 0; /* Comparison information for duplicate removal */

  128283.   KeyInfo *pKeyMerge;   /* Comparison information for merging rows */

  128284.   sqlite3 *db;          /* Database connection */

  128285.   ExprList *pOrderBy;   /* The ORDER BY clause */

  128286.   int nOrderBy;         /* Number of terms in the ORDER BY clause */

  128287.   int *aPermute;        /* Mapping from ORDER BY terms to result set columns */

  128288. 

  128289.   assert( p->pOrderBy!=0 );

  128290.   assert( pKeyDup==0 ); /* "Managed" code needs this.  Ticket #3382. */

  128291.   db = pParse->db;

  128292.   v = pParse->pVdbe;

  128293.   assert( v!=0 );       /* Already thrown the error if VDBE alloc failed */

  128294.   labelEnd = sqlite3VdbeMakeLabel(pParse);

  128295.   labelCmpr = sqlite3VdbeMakeLabel(pParse);

  128296. 

  128297. 

  128298.   /* Patch up the ORDER BY clause

  128299.   */

  128300.   op = p->op;  

  128301.   pPrior = p->pPrior;

  128302.   assert( pPrior->pOrderBy==0 );

  128303.   pOrderBy = p->pOrderBy;

  128304.   assert( pOrderBy );

  128305.   nOrderBy = pOrderBy->nExpr;

  128306. 

  128307.   /* For operators other than UNION ALL we have to make sure that

  128308.   ** the ORDER BY clause covers every term of the result set.  Add

  128309.   ** terms to the ORDER BY clause as necessary.

  128310.   */

  128311.   if( op!=TK_ALL ){

  128312.     for(i=1; db->mallocFailed==0 && i<=p->pEList->nExpr; i++){

  128313.       struct ExprList_item *pItem;

  128314.       for(j=0, pItem=pOrderBy->a; j<nOrderBy; j++, pItem++){

  128315.         assert( pItem->u.x.iOrderByCol>0 );

  128316.         if( pItem->u.x.iOrderByCol==i ) break;

  128317.       }

  128318.       if( j==nOrderBy ){

  128319.         Expr *pNew = sqlite3Expr(db, TK_INTEGER, 0);

  128320.         if( pNew==0 ) return SQLITE_NOMEM_BKPT;

  128321.         pNew->flags |= EP_IntValue;

  128322.         pNew->u.iValue = i;

  128323.         p->pOrderBy = pOrderBy = sqlite3ExprListAppend(pParse, pOrderBy, pNew);

  128324.         if( pOrderBy ) pOrderBy->a[nOrderBy++].u.x.iOrderByCol = (u16)i;

  128325.       }

  128326.     }

  128327.   }

  128328. 

  128329.   /* Compute the comparison permutation and keyinfo that is used with

  128330.   ** the permutation used to determine if the next

  128331.   ** row of results comes from selectA or selectB.  Also add explicit

  128332.   ** collations to the ORDER BY clause terms so that when the subqueries

  128333.   ** to the right and the left are evaluated, they use the correct

  128334.   ** collation.

  128335.   */

  128336.   aPermute = sqlite3DbMallocRawNN(db, sizeof(int)*(nOrderBy + 1));

  128337.   if( aPermute ){

  128338.     struct ExprList_item *pItem;

  128339.     aPermute[0] = nOrderBy;

  128340.     for(i=1, pItem=pOrderBy->a; i<=nOrderBy; i++, pItem++){

  128341.       assert( pItem->u.x.iOrderByCol>0 );

  128342.       assert( pItem->u.x.iOrderByCol<=p->pEList->nExpr );

  128343.       aPermute[i] = pItem->u.x.iOrderByCol - 1;

  128344.     }

  128345.     pKeyMerge = multiSelectOrderByKeyInfo(pParse, p, 1);

  128346.   }else{

  128347.     pKeyMerge = 0;

  128348.   }

  128349. 

  128350.   /* Reattach the ORDER BY clause to the query.

  128351.   */

  128352.   p->pOrderBy = pOrderBy;

  128353.   pPrior->pOrderBy = sqlite3ExprListDup(pParse->db, pOrderBy, 0);

  128354. 

  128355.   /* Allocate a range of temporary registers and the KeyInfo needed

  128356.   ** for the logic that removes duplicate result rows when the

  128357.   ** operator is UNION, EXCEPT, or INTERSECT (but not UNION ALL).

  128358.   */

  128359.   if( op==TK_ALL ){

  128360.     regPrev = 0;

  128361.   }else{

  128362.     int nExpr = p->pEList->nExpr;

  128363.     assert( nOrderBy>=nExpr || db->mallocFailed );

  128364.     regPrev = pParse->nMem+1;

  128365.     pParse->nMem += nExpr+1;

  128366.     sqlite3VdbeAddOp2(v, OP_Integer, 0, regPrev);

  128367.     pKeyDup = sqlite3KeyInfoAlloc(db, nExpr, 1);

  128368.     if( pKeyDup ){

  128369.       assert( sqlite3KeyInfoIsWriteable(pKeyDup) );

  128370.       for(i=0; i<nExpr; i++){

  128371.         pKeyDup->aColl[i] = multiSelectCollSeq(pParse, p, i);

  128372.         pKeyDup->aSortOrder[i] = 0;

  128373.       }

  128374.     }

  128375.   }

  128376.  

  128377.   /* Separate the left and the right query from one another

  128378.   */

  128379.   p->pPrior = 0;

  128380.   pPrior->pNext = 0;

  128381.   sqlite3ResolveOrderGroupBy(pParse, p, p->pOrderBy, "ORDER");

  128382.   if( pPrior->pPrior==0 ){

  128383.     sqlite3ResolveOrderGroupBy(pParse, pPrior, pPrior->pOrderBy, "ORDER");

  128384.   }

  128385. 

  128386.   /* Compute the limit registers */

  128387.   computeLimitRegisters(pParse, p, labelEnd);

  128388.   if( p->iLimit && op==TK_ALL ){

  128389.     regLimitA = ++pParse->nMem;

  128390.     regLimitB = ++pParse->nMem;

  128391.     sqlite3VdbeAddOp2(v, OP_Copy, p->iOffset ? p->iOffset+1 : p->iLimit,

  128392.                                   regLimitA);

  128393.     sqlite3VdbeAddOp2(v, OP_Copy, regLimitA, regLimitB);

  128394.   }else{

  128395.     regLimitA = regLimitB = 0;

  128396.   }

  128397.   sqlite3ExprDelete(db, p->pLimit);

  128398.   p->pLimit = 0;

  128399. 

  128400.   regAddrA = ++pParse->nMem;

  128401.   regAddrB = ++pParse->nMem;

  128402.   regOutA = ++pParse->nMem;

  128403.   regOutB = ++pParse->nMem;

  128404.   sqlite3SelectDestInit(&destA, SRT_Coroutine, regAddrA);

  128405.   sqlite3SelectDestInit(&destB, SRT_Coroutine, regAddrB);

  128406. 

  128407.   ExplainQueryPlan((pParse, 1, "MERGE (%s)", selectOpName(p->op)));

  128408. 

  128409.   /* Generate a coroutine to evaluate the SELECT statement to the

  128410.   ** left of the compound operator - the "A" select.

  128411.   */

  128412.   addrSelectA = sqlite3VdbeCurrentAddr(v) + 1;

  128413.   addr1 = sqlite3VdbeAddOp3(v, OP_InitCoroutine, regAddrA, 0, addrSelectA);

  128414.   VdbeComment((v, "left SELECT"));

  128415.   pPrior->iLimit = regLimitA;

  128416.   ExplainQueryPlan((pParse, 1, "LEFT"));

  128417.   sqlite3Select(pParse, pPrior, &destA);

  128418.   sqlite3VdbeEndCoroutine(v, regAddrA);

  128419.   sqlite3VdbeJumpHere(v, addr1);

  128420. 

  128421.   /* Generate a coroutine to evaluate the SELECT statement on 

  128422.   ** the right - the "B" select

  128423.   */

  128424.   addrSelectB = sqlite3VdbeCurrentAddr(v) + 1;

  128425.   addr1 = sqlite3VdbeAddOp3(v, OP_InitCoroutine, regAddrB, 0, addrSelectB);

  128426.   VdbeComment((v, "right SELECT"));

  128427.   savedLimit = p->iLimit;

  128428.   savedOffset = p->iOffset;

  128429.   p->iLimit = regLimitB;

  128430.   p->iOffset = 0;  

  128431.   ExplainQueryPlan((pParse, 1, "RIGHT"));

  128432.   sqlite3Select(pParse, p, &destB);

  128433.   p->iLimit = savedLimit;

  128434.   p->iOffset = savedOffset;

  128435.   sqlite3VdbeEndCoroutine(v, regAddrB);

  128436. 

  128437.   /* Generate a subroutine that outputs the current row of the A

  128438.   ** select as the next output row of the compound select.

  128439.   */

  128440.   VdbeNoopComment((v, "Output routine for A"));

  128441.   addrOutA = generateOutputSubroutine(pParse,

  128442.                  p, &destA, pDest, regOutA,

  128443.                  regPrev, pKeyDup, labelEnd);

  128444.   

  128445.   /* Generate a subroutine that outputs the current row of the B

  128446.   ** select as the next output row of the compound select.

  128447.   */

  128448.   if( op==TK_ALL || op==TK_UNION ){

  128449.     VdbeNoopComment((v, "Output routine for B"));

  128450.     addrOutB = generateOutputSubroutine(pParse,

  128451.                  p, &destB, pDest, regOutB,

  128452.                  regPrev, pKeyDup, labelEnd);

  128453.   }

  128454.   sqlite3KeyInfoUnref(pKeyDup);

  128455. 

  128456.   /* Generate a subroutine to run when the results from select A

  128457.   ** are exhausted and only data in select B remains.

  128458.   */

  128459.   if( op==TK_EXCEPT || op==TK_INTERSECT ){

  128460.     addrEofA_noB = addrEofA = labelEnd;

  128461.   }else{  

  128462.     VdbeNoopComment((v, "eof-A subroutine"));

  128463.     addrEofA = sqlite3VdbeAddOp2(v, OP_Gosub, regOutB, addrOutB);

  128464.     addrEofA_noB = sqlite3VdbeAddOp2(v, OP_Yield, regAddrB, labelEnd);

  128465.                                      VdbeCoverage(v);

  128466.     sqlite3VdbeGoto(v, addrEofA);

  128467.     p->nSelectRow = sqlite3LogEstAdd(p->nSelectRow, pPrior->nSelectRow);

  128468.   }

  128469. 

  128470.   /* Generate a subroutine to run when the results from select B

  128471.   ** are exhausted and only data in select A remains.

  128472.   */

  128473.   if( op==TK_INTERSECT ){

  128474.     addrEofB = addrEofA;

  128475.     if( p->nSelectRow > pPrior->nSelectRow ) p->nSelectRow = pPrior->nSelectRow;

  128476.   }else{  

  128477.     VdbeNoopComment((v, "eof-B subroutine"));

  128478.     addrEofB = sqlite3VdbeAddOp2(v, OP_Gosub, regOutA, addrOutA);

  128479.     sqlite3VdbeAddOp2(v, OP_Yield, regAddrA, labelEnd); VdbeCoverage(v);

  128480.     sqlite3VdbeGoto(v, addrEofB);

  128481.   }

  128482. 

  128483.   /* Generate code to handle the case of A<B

  128484.   */

  128485.   VdbeNoopComment((v, "A-lt-B subroutine"));

  128486.   addrAltB = sqlite3VdbeAddOp2(v, OP_Gosub, regOutA, addrOutA);

  128487.   sqlite3VdbeAddOp2(v, OP_Yield, regAddrA, addrEofA); VdbeCoverage(v);

  128488.   sqlite3VdbeGoto(v, labelCmpr);

  128489. 

  128490.   /* Generate code to handle the case of A==B

  128491.   */

  128492.   if( op==TK_ALL ){

  128493.     addrAeqB = addrAltB;

  128494.   }else if( op==TK_INTERSECT ){

  128495.     addrAeqB = addrAltB;

  128496.     addrAltB++;

  128497.   }else{

  128498.     VdbeNoopComment((v, "A-eq-B subroutine"));

  128499.     addrAeqB =

  128500.     sqlite3VdbeAddOp2(v, OP_Yield, regAddrA, addrEofA); VdbeCoverage(v);

  128501.     sqlite3VdbeGoto(v, labelCmpr);

  128502.   }

  128503. 

  128504.   /* Generate code to handle the case of A>B

  128505.   */

  128506.   VdbeNoopComment((v, "A-gt-B subroutine"));

  128507.   addrAgtB = sqlite3VdbeCurrentAddr(v);

  128508.   if( op==TK_ALL || op==TK_UNION ){

  128509.     sqlite3VdbeAddOp2(v, OP_Gosub, regOutB, addrOutB);

  128510.   }

  128511.   sqlite3VdbeAddOp2(v, OP_Yield, regAddrB, addrEofB); VdbeCoverage(v);

  128512.   sqlite3VdbeGoto(v, labelCmpr);

  128513. 

  128514.   /* This code runs once to initialize everything.

  128515.   */

  128516.   sqlite3VdbeJumpHere(v, addr1);

  128517.   sqlite3VdbeAddOp2(v, OP_Yield, regAddrA, addrEofA_noB); VdbeCoverage(v);

  128518.   sqlite3VdbeAddOp2(v, OP_Yield, regAddrB, addrEofB); VdbeCoverage(v);

  128519. 

  128520.   /* Implement the main merge loop

  128521.   */

  128522.   sqlite3VdbeResolveLabel(v, labelCmpr);

  128523.   sqlite3VdbeAddOp4(v, OP_Permutation, 0, 0, 0, (char*)aPermute, P4_INTARRAY);

  128524.   sqlite3VdbeAddOp4(v, OP_Compare, destA.iSdst, destB.iSdst, nOrderBy,

  128525.                          (char*)pKeyMerge, P4_KEYINFO);

  128526.   sqlite3VdbeChangeP5(v, OPFLAG_PERMUTE);

  128527.   sqlite3VdbeAddOp3(v, OP_Jump, addrAltB, addrAeqB, addrAgtB); VdbeCoverage(v);

  128528. 

  128529.   /* Jump to the this point in order to terminate the query.

  128530.   */

  128531.   sqlite3VdbeResolveLabel(v, labelEnd);

  128532. 

  128533.   /* Reassembly the compound query so that it will be freed correctly

  128534.   ** by the calling function */

  128535.   if( p->pPrior ){

  128536.     sqlite3SelectDelete(db, p->pPrior);

  128537.   }

  128538.   p->pPrior = pPrior;

  128539.   pPrior->pNext = p;

  128540. 

  128541.   /*** TBD:  Insert subroutine calls to close cursors on incomplete

  128542.   **** subqueries ****/

  128543.   ExplainQueryPlanPop(pParse);

  128544.   return pParse->nErr!=0;

  128545. }

  128546. #endif

  128547. 

  128548. #if !defined(SQLITE_OMIT_SUBQUERY) || !defined(SQLITE_OMIT_VIEW)

  128549. 

  128550. /* An instance of the SubstContext object describes an substitution edit

  128551. ** to be performed on a parse tree.

  128552. **

  128553. ** All references to columns in table iTable are to be replaced by corresponding

  128554. ** expressions in pEList.

  128555. */

  128556. typedef struct SubstContext {

  128557.   Parse *pParse;            /* The parsing context */

  128558.   int iTable;               /* Replace references to this table */

  128559.   int iNewTable;            /* New table number */

  128560.   int isLeftJoin;           /* Add TK_IF_NULL_ROW opcodes on each replacement */

  128561.   ExprList *pEList;         /* Replacement expressions */

  128562. } SubstContext;

  128563. 

  128564. /* Forward Declarations */

  128565. static void substExprList(SubstContext*, ExprList*);

  128566. static void substSelect(SubstContext*, Select*, int);

  128567. 

  128568. /*

  128569. ** Scan through the expression pExpr.  Replace every reference to

  128570. ** a column in table number iTable with a copy of the iColumn-th

  128571. ** entry in pEList.  (But leave references to the ROWID column 

  128572. ** unchanged.)

  128573. **

  128574. ** This routine is part of the flattening procedure.  A subquery

  128575. ** whose result set is defined by pEList appears as entry in the

  128576. ** FROM clause of a SELECT such that the VDBE cursor assigned to that

  128577. ** FORM clause entry is iTable.  This routine makes the necessary 

  128578. ** changes to pExpr so that it refers directly to the source table

  128579. ** of the subquery rather the result set of the subquery.

  128580. */

  128581. static Expr *substExpr(

  128582.   SubstContext *pSubst,  /* Description of the substitution */

  128583.   Expr *pExpr            /* Expr in which substitution occurs */

  128584. ){

  128585.   if( pExpr==0 ) return 0;

  128586.   if( ExprHasProperty(pExpr, EP_FromJoin)

  128587.    && pExpr->iRightJoinTable==pSubst->iTable

  128588.   ){

  128589.     pExpr->iRightJoinTable = pSubst->iNewTable;

  128590.   }

  128591.   if( pExpr->op==TK_COLUMN && pExpr->iTable==pSubst->iTable ){

  128592.     if( pExpr->iColumn<0 ){

  128593.       pExpr->op = TK_NULL;

  128594.     }else{

  128595.       Expr *pNew;

  128596.       Expr *pCopy = pSubst->pEList->a[pExpr->iColumn].pExpr;

  128597.       Expr ifNullRow;

  128598.       assert( pSubst->pEList!=0 && pExpr->iColumn<pSubst->pEList->nExpr );

  128599.       assert( pExpr->pRight==0 );

  128600.       if( sqlite3ExprIsVector(pCopy) ){

  128601.         sqlite3VectorErrorMsg(pSubst->pParse, pCopy);

  128602.       }else{

  128603.         sqlite3 *db = pSubst->pParse->db;

  128604.         if( pSubst->isLeftJoin && pCopy->op!=TK_COLUMN ){

  128605.           memset(&ifNullRow, 0, sizeof(ifNullRow));

  128606.           ifNullRow.op = TK_IF_NULL_ROW;

  128607.           ifNullRow.pLeft = pCopy;

  128608.           ifNullRow.iTable = pSubst->iNewTable;

  128609.           pCopy = &ifNullRow;

  128610.         }

  128611.         testcase( ExprHasProperty(pCopy, EP_Subquery) );

  128612.         pNew = sqlite3ExprDup(db, pCopy, 0);

  128613.         if( pNew && pSubst->isLeftJoin ){

  128614.           ExprSetProperty(pNew, EP_CanBeNull);

  128615.         }

  128616.         if( pNew && ExprHasProperty(pExpr,EP_FromJoin) ){

  128617.           pNew->iRightJoinTable = pExpr->iRightJoinTable;

  128618.           ExprSetProperty(pNew, EP_FromJoin);

  128619.         }

  128620.         sqlite3ExprDelete(db, pExpr);

  128621.         pExpr = pNew;

  128622.       }

  128623.     }

  128624.   }else{

  128625.     if( pExpr->op==TK_IF_NULL_ROW && pExpr->iTable==pSubst->iTable ){

  128626.       pExpr->iTable = pSubst->iNewTable;

  128627.     }

  128628.     pExpr->pLeft = substExpr(pSubst, pExpr->pLeft);

  128629.     pExpr->pRight = substExpr(pSubst, pExpr->pRight);

  128630.     if( ExprHasProperty(pExpr, EP_xIsSelect) ){

  128631.       substSelect(pSubst, pExpr->x.pSelect, 1);

  128632.     }else{

  128633.       substExprList(pSubst, pExpr->x.pList);

  128634.     }

  128635.   }

  128636.   return pExpr;

  128637. }

  128638. static void substExprList(

  128639.   SubstContext *pSubst, /* Description of the substitution */

  128640.   ExprList *pList       /* List to scan and in which to make substitutes */

  128641. ){

  128642.   int i;

  128643.   if( pList==0 ) return;

  128644.   for(i=0; i<pList->nExpr; i++){

  128645.     pList->a[i].pExpr = substExpr(pSubst, pList->a[i].pExpr);

  128646.   }

  128647. }

  128648. static void substSelect(

  128649.   SubstContext *pSubst, /* Description of the substitution */

  128650.   Select *p,            /* SELECT statement in which to make substitutions */

  128651.   int doPrior           /* Do substitutes on p->pPrior too */

  128652. ){

  128653.   SrcList *pSrc;

  128654.   struct SrcList_item *pItem;

  128655.   int i;

  128656.   if( !p ) return;

  128657.   do{

  128658.     substExprList(pSubst, p->pEList);

  128659.     substExprList(pSubst, p->pGroupBy);

  128660.     substExprList(pSubst, p->pOrderBy);

  128661.     p->pHaving = substExpr(pSubst, p->pHaving);

  128662.     p->pWhere = substExpr(pSubst, p->pWhere);

  128663.     pSrc = p->pSrc;

  128664.     assert( pSrc!=0 );

  128665.     for(i=pSrc->nSrc, pItem=pSrc->a; i>0; i--, pItem++){

  128666.       substSelect(pSubst, pItem->pSelect, 1);

  128667.       if( pItem->fg.isTabFunc ){

  128668.         substExprList(pSubst, pItem->u1.pFuncArg);

  128669.       }

  128670.     }

  128671.   }while( doPrior && (p = p->pPrior)!=0 );

  128672. }

  128673. #endif /* !defined(SQLITE_OMIT_SUBQUERY) || !defined(SQLITE_OMIT_VIEW) */

  128674. 

  128675. #if !defined(SQLITE_OMIT_SUBQUERY) || !defined(SQLITE_OMIT_VIEW)

  128676. /*

  128677. ** This routine attempts to flatten subqueries as a performance optimization.

  128678. ** This routine returns 1 if it makes changes and 0 if no flattening occurs.

  128679. **

  128680. ** To understand the concept of flattening, consider the following

  128681. ** query:

  128682. **

  128683. **     SELECT a FROM (SELECT x+y AS a FROM t1 WHERE z<100) WHERE a>5

  128684. **

  128685. ** The default way of implementing this query is to execute the

  128686. ** subquery first and store the results in a temporary table, then

  128687. ** run the outer query on that temporary table.  This requires two

  128688. ** passes over the data.  Furthermore, because the temporary table

  128689. ** has no indices, the WHERE clause on the outer query cannot be

  128690. ** optimized.

  128691. **

  128692. ** This routine attempts to rewrite queries such as the above into

  128693. ** a single flat select, like this:

  128694. **

  128695. **     SELECT x+y AS a FROM t1 WHERE z<100 AND a>5

  128696. **

  128697. ** The code generated for this simplification gives the same result

  128698. ** but only has to scan the data once.  And because indices might 

  128699. ** exist on the table t1, a complete scan of the data might be

  128700. ** avoided.

  128701. **

  128702. ** Flattening is subject to the following constraints:

  128703. **

  128704. **  (**)  We no longer attempt to flatten aggregate subqueries. Was:

  128705. **        The subquery and the outer query cannot both be aggregates.

  128706. **

  128707. **  (**)  We no longer attempt to flatten aggregate subqueries. Was:

  128708. **        (2) If the subquery is an aggregate then

  128709. **        (2a) the outer query must not be a join and

  128710. **        (2b) the outer query must not use subqueries

  128711. **             other than the one FROM-clause subquery that is a candidate

  128712. **             for flattening.  (This is due to ticket [2f7170d73bf9abf80]

  128713. **             from 2015-02-09.)

  128714. **

  128715. **   (3)  If the subquery is the right operand of a LEFT JOIN then

  128716. **        (3a) the subquery may not be a join and

  128717. **        (3b) the FROM clause of the subquery may not contain a virtual

  128718. **             table and

  128719. **        (3c) the outer query may not be an aggregate.

  128720. **

  128721. **   (4)  The subquery can not be DISTINCT.

  128722. **

  128723. **  (**)  At one point restrictions (4) and (5) defined a subset of DISTINCT

  128724. **        sub-queries that were excluded from this optimization. Restriction 

  128725. **        (4) has since been expanded to exclude all DISTINCT subqueries.

  128726. **

  128727. **  (**)  We no longer attempt to flatten aggregate subqueries.  Was:

  128728. **        If the subquery is aggregate, the outer query may not be DISTINCT.

  128729. **

  128730. **   (7)  The subquery must have a FROM clause.  TODO:  For subqueries without

  128731. **        A FROM clause, consider adding a FROM clause with the special

  128732. **        table sqlite_once that consists of a single row containing a

  128733. **        single NULL.

  128734. **

  128735. **   (8)  If the subquery uses LIMIT then the outer query may not be a join.

  128736. **

  128737. **   (9)  If the subquery uses LIMIT then the outer query may not be aggregate.

  128738. **

  128739. **  (**)  Restriction (10) was removed from the code on 2005-02-05 but we

  128740. **        accidently carried the comment forward until 2014-09-15.  Original

  128741. **        constraint: "If the subquery is aggregate then the outer query 

  128742. **        may not use LIMIT."

  128743. **

  128744. **  (11)  The subquery and the outer query may not both have ORDER BY clauses.

  128745. **

  128746. **  (**)  Not implemented.  Subsumed into restriction (3).  Was previously

  128747. **        a separate restriction deriving from ticket #350.

  128748. **

  128749. **  (13)  The subquery and outer query may not both use LIMIT.

  128750. **

  128751. **  (14)  The subquery may not use OFFSET.

  128752. **

  128753. **  (15)  If the outer query is part of a compound select, then the

  128754. **        subquery may not use LIMIT.

  128755. **        (See ticket #2339 and ticket [02a8e81d44]).

  128756. **

  128757. **  (16)  If the outer query is aggregate, then the subquery may not

  128758. **        use ORDER BY.  (Ticket #2942)  This used to not matter

  128759. **        until we introduced the group_concat() function.  

  128760. **

  128761. **  (17)  If the subquery is a compound select, then

  128762. **        (17a) all compound operators must be a UNION ALL, and

  128763. **        (17b) no terms within the subquery compound may be aggregate

  128764. **              or DISTINCT, and

  128765. **        (17c) every term within the subquery compound must have a FROM clause

  128766. **        (17d) the outer query may not be

  128767. **              (17d1) aggregate, or

  128768. **              (17d2) DISTINCT, or

  128769. **              (17d3) a join.

  128770. **

  128771. **        The parent and sub-query may contain WHERE clauses. Subject to

  128772. **        rules (11), (13) and (14), they may also contain ORDER BY,

  128773. **        LIMIT and OFFSET clauses.  The subquery cannot use any compound

  128774. **        operator other than UNION ALL because all the other compound

  128775. **        operators have an implied DISTINCT which is disallowed by

  128776. **        restriction (4).

  128777. **

  128778. **        Also, each component of the sub-query must return the same number

  128779. **        of result columns. This is actually a requirement for any compound

  128780. **        SELECT statement, but all the code here does is make sure that no

  128781. **        such (illegal) sub-query is flattened. The caller will detect the

  128782. **        syntax error and return a detailed message.

  128783. **

  128784. **  (18)  If the sub-query is a compound select, then all terms of the

  128785. **        ORDER BY clause of the parent must be simple references to 

  128786. **        columns of the sub-query.

  128787. **

  128788. **  (19)  If the subquery uses LIMIT then the outer query may not

  128789. **        have a WHERE clause.

  128790. **

  128791. **  (20)  If the sub-query is a compound select, then it must not use

  128792. **        an ORDER BY clause.  Ticket #3773.  We could relax this constraint

  128793. **        somewhat by saying that the terms of the ORDER BY clause must

  128794. **        appear as unmodified result columns in the outer query.  But we

  128795. **        have other optimizations in mind to deal with that case.

  128796. **

  128797. **  (21)  If the subquery uses LIMIT then the outer query may not be

  128798. **        DISTINCT.  (See ticket [752e1646fc]).

  128799. **

  128800. **  (22)  The subquery may not be a recursive CTE.

  128801. **

  128802. **  (**)  Subsumed into restriction (17d3).  Was: If the outer query is

  128803. **        a recursive CTE, then the sub-query may not be a compound query.

  128804. **        This restriction is because transforming the

  128805. **        parent to a compound query confuses the code that handles

  128806. **        recursive queries in multiSelect().

  128807. **

  128808. **  (**)  We no longer attempt to flatten aggregate subqueries.  Was:

  128809. **        The subquery may not be an aggregate that uses the built-in min() or 

  128810. **        or max() functions.  (Without this restriction, a query like:

  128811. **        "SELECT x FROM (SELECT max(y), x FROM t1)" would not necessarily

  128812. **        return the value X for which Y was maximal.)

  128813. **

  128814. **  (25)  If either the subquery or the parent query contains a window

  128815. **        function in the select list or ORDER BY clause, flattening

  128816. **        is not attempted.

  128817. **

  128818. **

  128819. ** In this routine, the "p" parameter is a pointer to the outer query.

  128820. ** The subquery is p->pSrc->a[iFrom].  isAgg is true if the outer query

  128821. ** uses aggregates.

  128822. **

  128823. ** If flattening is not attempted, this routine is a no-op and returns 0.

  128824. ** If flattening is attempted this routine returns 1.

  128825. **

  128826. ** All of the expression analysis must occur on both the outer query and

  128827. ** the subquery before this routine runs.

  128828. */

  128829. static int flattenSubquery(

  128830.   Parse *pParse,       /* Parsing context */

  128831.   Select *p,           /* The parent or outer SELECT statement */

  128832.   int iFrom,           /* Index in p->pSrc->a[] of the inner subquery */

  128833.   int isAgg            /* True if outer SELECT uses aggregate functions */

  128834. ){

  128835.   const char *zSavedAuthContext = pParse->zAuthContext;

  128836.   Select *pParent;    /* Current UNION ALL term of the other query */

  128837.   Select *pSub;       /* The inner query or "subquery" */

  128838.   Select *pSub1;      /* Pointer to the rightmost select in sub-query */

  128839.   SrcList *pSrc;      /* The FROM clause of the outer query */

  128840.   SrcList *pSubSrc;   /* The FROM clause of the subquery */

  128841.   int iParent;        /* VDBE cursor number of the pSub result set temp table */

  128842.   int iNewParent = -1;/* Replacement table for iParent */

  128843.   int isLeftJoin = 0; /* True if pSub is the right side of a LEFT JOIN */    

  128844.   int i;              /* Loop counter */

  128845.   Expr *pWhere;                    /* The WHERE clause */

  128846.   struct SrcList_item *pSubitem;   /* The subquery */

  128847.   sqlite3 *db = pParse->db;

  128848. 

  128849.   /* Check to see if flattening is permitted.  Return 0 if not.

  128850.   */

  128851.   assert( p!=0 );

  128852.   assert( p->pPrior==0 );

  128853.   if( OptimizationDisabled(db, SQLITE_QueryFlattener) ) return 0;

  128854.   pSrc = p->pSrc;

  128855.   assert( pSrc && iFrom>=0 && iFrom<pSrc->nSrc );

  128856.   pSubitem = &pSrc->a[iFrom];

  128857.   iParent = pSubitem->iCursor;

  128858.   pSub = pSubitem->pSelect;

  128859.   assert( pSub!=0 );

  128860. 

  128861. #ifndef SQLITE_OMIT_WINDOWFUNC

  128862.   if( p->pWin || pSub->pWin ) return 0;                  /* Restriction (25) */

  128863. #endif

  128864. 

  128865.   pSubSrc = pSub->pSrc;

  128866.   assert( pSubSrc );

  128867.   /* Prior to version 3.1.2, when LIMIT and OFFSET had to be simple constants,

  128868.   ** not arbitrary expressions, we allowed some combining of LIMIT and OFFSET

  128869.   ** because they could be computed at compile-time.  But when LIMIT and OFFSET

  128870.   ** became arbitrary expressions, we were forced to add restrictions (13)

  128871.   ** and (14). */

  128872.   if( pSub->pLimit && p->pLimit ) return 0;              /* Restriction (13) */

  128873.   if( pSub->pLimit && pSub->pLimit->pRight ) return 0;   /* Restriction (14) */

  128874.   if( (p->selFlags & SF_Compound)!=0 && pSub->pLimit ){

  128875.     return 0;                                            /* Restriction (15) */

  128876.   }

  128877.   if( pSubSrc->nSrc==0 ) return 0;                       /* Restriction (7)  */

  128878.   if( pSub->selFlags & SF_Distinct ) return 0;           /* Restriction (4)  */

  128879.   if( pSub->pLimit && (pSrc->nSrc>1 || isAgg) ){

  128880.      return 0;         /* Restrictions (8)(9) */

  128881.   }

  128882.   if( p->pOrderBy && pSub->pOrderBy ){

  128883.      return 0;                                           /* Restriction (11) */

  128884.   }

  128885.   if( isAgg && pSub->pOrderBy ) return 0;                /* Restriction (16) */

  128886.   if( pSub->pLimit && p->pWhere ) return 0;              /* Restriction (19) */

  128887.   if( pSub->pLimit && (p->selFlags & SF_Distinct)!=0 ){

  128888.      return 0;         /* Restriction (21) */

  128889.   }

  128890.   if( pSub->selFlags & (SF_Recursive) ){

  128891.     return 0; /* Restrictions (22) */

  128892.   }

  128893. 

  128894.   /*

  128895.   ** If the subquery is the right operand of a LEFT JOIN, then the

  128896.   ** subquery may not be a join itself (3a). Example of why this is not

  128897.   ** allowed:

  128898.   **

  128899.   **         t1 LEFT OUTER JOIN (t2 JOIN t3)

  128900.   **

  128901.   ** If we flatten the above, we would get

  128902.   **

  128903.   **         (t1 LEFT OUTER JOIN t2) JOIN t3

  128904.   **

  128905.   ** which is not at all the same thing.

  128906.   **

  128907.   ** If the subquery is the right operand of a LEFT JOIN, then the outer

  128908.   ** query cannot be an aggregate. (3c)  This is an artifact of the way

  128909.   ** aggregates are processed - there is no mechanism to determine if

  128910.   ** the LEFT JOIN table should be all-NULL.

  128911.   **

  128912.   ** See also tickets #306, #350, and #3300.

  128913.   */

  128914.   if( (pSubitem->fg.jointype & JT_OUTER)!=0 ){

  128915.     isLeftJoin = 1;

  128916.     if( pSubSrc->nSrc>1 || isAgg || IsVirtual(pSubSrc->a[0].pTab) ){

  128917.       /*  (3a)             (3c)     (3b) */

  128918.       return 0;

  128919.     }

  128920.   }

  128921. #ifdef SQLITE_EXTRA_IFNULLROW

  128922.   else if( iFrom>0 && !isAgg ){

  128923.     /* Setting isLeftJoin to -1 causes OP_IfNullRow opcodes to be generated for

  128924.     ** every reference to any result column from subquery in a join, even

  128925.     ** though they are not necessary.  This will stress-test the OP_IfNullRow 

  128926.     ** opcode. */

  128927.     isLeftJoin = -1;

  128928.   }

  128929. #endif

  128930. 

  128931.   /* Restriction (17): If the sub-query is a compound SELECT, then it must

  128932.   ** use only the UNION ALL operator. And none of the simple select queries

  128933.   ** that make up the compound SELECT are allowed to be aggregate or distinct

  128934.   ** queries.

  128935.   */

  128936.   if( pSub->pPrior ){

  128937.     if( pSub->pOrderBy ){

  128938.       return 0;  /* Restriction (20) */

  128939.     }

  128940.     if( isAgg || (p->selFlags & SF_Distinct)!=0 || pSrc->nSrc!=1 ){

  128941.       return 0; /* (17d1), (17d2), or (17d3) */

  128942.     }

  128943.     for(pSub1=pSub; pSub1; pSub1=pSub1->pPrior){

  128944.       testcase( (pSub1->selFlags & (SF_Distinct|SF_Aggregate))==SF_Distinct );

  128945.       testcase( (pSub1->selFlags & (SF_Distinct|SF_Aggregate))==SF_Aggregate );

  128946.       assert( pSub->pSrc!=0 );

  128947.       assert( pSub->pEList->nExpr==pSub1->pEList->nExpr );

  128948.       if( (pSub1->selFlags & (SF_Distinct|SF_Aggregate))!=0    /* (17b) */

  128949.        || (pSub1->pPrior && pSub1->op!=TK_ALL)                 /* (17a) */

  128950.        || pSub1->pSrc->nSrc<1                                  /* (17c) */

  128951.       ){

  128952.         return 0;

  128953.       }

  128954.       testcase( pSub1->pSrc->nSrc>1 );

  128955.     }

  128956. 

  128957.     /* Restriction (18). */

  128958.     if( p->pOrderBy ){

  128959.       int ii;

  128960.       for(ii=0; ii<p->pOrderBy->nExpr; ii++){

  128961.         if( p->pOrderBy->a[ii].u.x.iOrderByCol==0 ) return 0;

  128962.       }

  128963.     }

  128964.   }

  128965. 

  128966.   /* Ex-restriction (23):

  128967.   ** The only way that the recursive part of a CTE can contain a compound

  128968.   ** subquery is for the subquery to be one term of a join.  But if the

  128969.   ** subquery is a join, then the flattening has already been stopped by

  128970.   ** restriction (17d3)

  128971.   */

  128972.   assert( (p->selFlags & SF_Recursive)==0 || pSub->pPrior==0 );

  128973. 

  128974.   /***** If we reach this point, flattening is permitted. *****/

  128975.   SELECTTRACE(1,pParse,p,("flatten %u.%p from term %d\n",

  128976.                    pSub->selId, pSub, iFrom));

  128977. 

  128978.   /* Authorize the subquery */

  128979.   pParse->zAuthContext = pSubitem->zName;

  128980.   TESTONLY(i =) sqlite3AuthCheck(pParse, SQLITE_SELECT, 0, 0, 0);

  128981.   testcase( i==SQLITE_DENY );

  128982.   pParse->zAuthContext = zSavedAuthContext;

  128983. 

  128984.   /* If the sub-query is a compound SELECT statement, then (by restrictions

  128985.   ** 17 and 18 above) it must be a UNION ALL and the parent query must 

  128986.   ** be of the form:

  128987.   **

  128988.   **     SELECT <expr-list> FROM (<sub-query>) <where-clause> 

  128989.   **

  128990.   ** followed by any ORDER BY, LIMIT and/or OFFSET clauses. This block

  128991.   ** creates N-1 copies of the parent query without any ORDER BY, LIMIT or 

  128992.   ** OFFSET clauses and joins them to the left-hand-side of the original

  128993.   ** using UNION ALL operators. In this case N is the number of simple

  128994.   ** select statements in the compound sub-query.

  128995.   **

  128996.   ** Example:

  128997.   **

  128998.   **     SELECT a+1 FROM (

  128999.   **        SELECT x FROM tab

  129000.   **        UNION ALL

  129001.   **        SELECT y FROM tab

  129002.   **        UNION ALL

  129003.   **        SELECT abs(z*2) FROM tab2

  129004.   **     ) WHERE a!=5 ORDER BY 1

  129005.   **

  129006.   ** Transformed into:

  129007.   **

  129008.   **     SELECT x+1 FROM tab WHERE x+1!=5

  129009.   **     UNION ALL

  129010.   **     SELECT y+1 FROM tab WHERE y+1!=5

  129011.   **     UNION ALL

  129012.   **     SELECT abs(z*2)+1 FROM tab2 WHERE abs(z*2)+1!=5

  129013.   **     ORDER BY 1

  129014.   **

  129015.   ** We call this the "compound-subquery flattening".

  129016.   */

  129017.   for(pSub=pSub->pPrior; pSub; pSub=pSub->pPrior){

  129018.     Select *pNew;

  129019.     ExprList *pOrderBy = p->pOrderBy;

  129020.     Expr *pLimit = p->pLimit;

  129021.     Select *pPrior = p->pPrior;

  129022.     p->pOrderBy = 0;

  129023.     p->pSrc = 0;

  129024.     p->pPrior = 0;

  129025.     p->pLimit = 0;

  129026.     pNew = sqlite3SelectDup(db, p, 0);

  129027.     p->pLimit = pLimit;

  129028.     p->pOrderBy = pOrderBy;

  129029.     p->pSrc = pSrc;

  129030.     p->op = TK_ALL;

  129031.     if( pNew==0 ){

  129032.       p->pPrior = pPrior;

  129033.     }else{

  129034.       pNew->pPrior = pPrior;

  129035.       if( pPrior ) pPrior->pNext = pNew;

  129036.       pNew->pNext = p;

  129037.       p->pPrior = pNew;

  129038.       SELECTTRACE(2,pParse,p,("compound-subquery flattener"

  129039.                               " creates %u as peer\n",pNew->selId));

  129040.     }

  129041.     if( db->mallocFailed ) return 1;

  129042.   }

  129043. 

  129044.   /* Begin flattening the iFrom-th entry of the FROM clause 

  129045.   ** in the outer query.

  129046.   */

  129047.   pSub = pSub1 = pSubitem->pSelect;

  129048. 

  129049.   /* Delete the transient table structure associated with the

  129050.   ** subquery

  129051.   */

  129052.   sqlite3DbFree(db, pSubitem->zDatabase);

  129053.   sqlite3DbFree(db, pSubitem->zName);

  129054.   sqlite3DbFree(db, pSubitem->zAlias);

  129055.   pSubitem->zDatabase = 0;

  129056.   pSubitem->zName = 0;

  129057.   pSubitem->zAlias = 0;

  129058.   pSubitem->pSelect = 0;

  129059. 

  129060.   /* Defer deleting the Table object associated with the

  129061.   ** subquery until code generation is

  129062.   ** complete, since there may still exist Expr.pTab entries that

  129063.   ** refer to the subquery even after flattening.  Ticket #3346.

  129064.   **

  129065.   ** pSubitem->pTab is always non-NULL by test restrictions and tests above.

  129066.   */

  129067.   if( ALWAYS(pSubitem->pTab!=0) ){

  129068.     Table *pTabToDel = pSubitem->pTab;

  129069.     if( pTabToDel->nTabRef==1 ){

  129070.       Parse *pToplevel = sqlite3ParseToplevel(pParse);

  129071.       pTabToDel->pNextZombie = pToplevel->pZombieTab;

  129072.       pToplevel->pZombieTab = pTabToDel;

  129073.     }else{

  129074.       pTabToDel->nTabRef--;

  129075.     }

  129076.     pSubitem->pTab = 0;

  129077.   }

  129078. 

  129079.   /* The following loop runs once for each term in a compound-subquery

  129080.   ** flattening (as described above).  If we are doing a different kind

  129081.   ** of flattening - a flattening other than a compound-subquery flattening -

  129082.   ** then this loop only runs once.

  129083.   **

  129084.   ** This loop moves all of the FROM elements of the subquery into the

  129085.   ** the FROM clause of the outer query.  Before doing this, remember

  129086.   ** the cursor number for the original outer query FROM element in

  129087.   ** iParent.  The iParent cursor will never be used.  Subsequent code

  129088.   ** will scan expressions looking for iParent references and replace

  129089.   ** those references with expressions that resolve to the subquery FROM

  129090.   ** elements we are now copying in.

  129091.   */

  129092.   for(pParent=p; pParent; pParent=pParent->pPrior, pSub=pSub->pPrior){

  129093.     int nSubSrc;

  129094.     u8 jointype = 0;

  129095.     pSubSrc = pSub->pSrc;     /* FROM clause of subquery */

  129096.     nSubSrc = pSubSrc->nSrc;  /* Number of terms in subquery FROM clause */

  129097.     pSrc = pParent->pSrc;     /* FROM clause of the outer query */

  129098. 

  129099.     if( pSrc ){

  129100.       assert( pParent==p );  /* First time through the loop */

  129101.       jointype = pSubitem->fg.jointype;

  129102.     }else{

  129103.       assert( pParent!=p );  /* 2nd and subsequent times through the loop */

  129104.       pSrc = sqlite3SrcListAppend(pParse, 0, 0, 0);

  129105.       if( pSrc==0 ) break;

  129106.       pParent->pSrc = pSrc;

  129107.     }

  129108. 

  129109.     /* The subquery uses a single slot of the FROM clause of the outer

  129110.     ** query.  If the subquery has more than one element in its FROM clause,

  129111.     ** then expand the outer query to make space for it to hold all elements

  129112.     ** of the subquery.

  129113.     **

  129114.     ** Example:

  129115.     **

  129116.     **    SELECT * FROM tabA, (SELECT * FROM sub1, sub2), tabB;

  129117.     **

  129118.     ** The outer query has 3 slots in its FROM clause.  One slot of the

  129119.     ** outer query (the middle slot) is used by the subquery.  The next

  129120.     ** block of code will expand the outer query FROM clause to 4 slots.

  129121.     ** The middle slot is expanded to two slots in order to make space

  129122.     ** for the two elements in the FROM clause of the subquery.

  129123.     */

  129124.     if( nSubSrc>1 ){

  129125.       pSrc = sqlite3SrcListEnlarge(pParse, pSrc, nSubSrc-1,iFrom+1);

  129126.       if( pSrc==0 ) break;

  129127.       pParent->pSrc = pSrc;

  129128.     }

  129129. 

  129130.     /* Transfer the FROM clause terms from the subquery into the

  129131.     ** outer query.

  129132.     */

  129133.     for(i=0; i<nSubSrc; i++){

  129134.       sqlite3IdListDelete(db, pSrc->a[i+iFrom].pUsing);

  129135.       assert( pSrc->a[i+iFrom].fg.isTabFunc==0 );

  129136.       pSrc->a[i+iFrom] = pSubSrc->a[i];

  129137.       iNewParent = pSubSrc->a[i].iCursor;

  129138.       memset(&pSubSrc->a[i], 0, sizeof(pSubSrc->a[i]));

  129139.     }

  129140.     pSrc->a[iFrom].fg.jointype = jointype;

  129141.   

  129142.     /* Now begin substituting subquery result set expressions for 

  129143.     ** references to the iParent in the outer query.

  129144.     ** 

  129145.     ** Example:

  129146.     **

  129147.     **   SELECT a+5, b*10 FROM (SELECT x*3 AS a, y+10 AS b FROM t1) WHERE a>b;

  129148.     **   \                     \_____________ subquery __________/          /

  129149.     **    \_____________________ outer query ______________________________/

  129150.     **

  129151.     ** We look at every expression in the outer query and every place we see

  129152.     ** "a" we substitute "x*3" and every place we see "b" we substitute "y+10".

  129153.     */

  129154.     if( pSub->pOrderBy ){

  129155.       /* At this point, any non-zero iOrderByCol values indicate that the

  129156.       ** ORDER BY column expression is identical to the iOrderByCol'th

  129157.       ** expression returned by SELECT statement pSub. Since these values

  129158.       ** do not necessarily correspond to columns in SELECT statement pParent,

  129159.       ** zero them before transfering the ORDER BY clause.

  129160.       **

  129161.       ** Not doing this may cause an error if a subsequent call to this

  129162.       ** function attempts to flatten a compound sub-query into pParent

  129163.       ** (the only way this can happen is if the compound sub-query is

  129164.       ** currently part of pSub->pSrc). See ticket [d11a6e908f].  */

  129165.       ExprList *pOrderBy = pSub->pOrderBy;

  129166.       for(i=0; i<pOrderBy->nExpr; i++){

  129167.         pOrderBy->a[i].u.x.iOrderByCol = 0;

  129168.       }

  129169.       assert( pParent->pOrderBy==0 );

  129170.       pParent->pOrderBy = pOrderBy;

  129171.       pSub->pOrderBy = 0;

  129172.     }

  129173.     pWhere = pSub->pWhere;

  129174.     pSub->pWhere = 0;

  129175.     if( isLeftJoin>0 ){

  129176.       setJoinExpr(pWhere, iNewParent);

  129177.     }

  129178.     pParent->pWhere = sqlite3ExprAnd(pParse, pWhere, pParent->pWhere);

  129179.     if( db->mallocFailed==0 ){

  129180.       SubstContext x;

  129181.       x.pParse = pParse;

  129182.       x.iTable = iParent;

  129183.       x.iNewTable = iNewParent;

  129184.       x.isLeftJoin = isLeftJoin;

  129185.       x.pEList = pSub->pEList;

  129186.       substSelect(&x, pParent, 0);

  129187.     }

  129188.   

  129189.     /* The flattened query is a compound if either the inner or the

  129190.     ** outer query is a compound. */

  129191.     pParent->selFlags |= pSub->selFlags & SF_Compound;

  129192.     assert( (pSub->selFlags & SF_Distinct)==0 ); /* restriction (17b) */

  129193.   

  129194.     /*

  129195.     ** SELECT ... FROM (SELECT ... LIMIT a OFFSET b) LIMIT x OFFSET y;

  129196.     **

  129197.     ** One is tempted to try to add a and b to combine the limits.  But this

  129198.     ** does not work if either limit is negative.

  129199.     */

  129200.     if( pSub->pLimit ){

  129201.       pParent->pLimit = pSub->pLimit;

  129202.       pSub->pLimit = 0;

  129203.     }

  129204.   }

  129205. 

  129206.   /* Finially, delete what is left of the subquery and return

  129207.   ** success.

  129208.   */

  129209.   sqlite3SelectDelete(db, pSub1);

  129210. 

  129211. #if SELECTTRACE_ENABLED

  129212.   if( sqlite3SelectTrace & 0x100 ){

  129213.     SELECTTRACE(0x100,pParse,p,("After flattening:\n"));

  129214.     sqlite3TreeViewSelect(0, p, 0);

  129215.   }

  129216. #endif

  129217. 

  129218.   return 1;

  129219. }

  129220. #endif /* !defined(SQLITE_OMIT_SUBQUERY) || !defined(SQLITE_OMIT_VIEW) */

  129221. 

  129222. /*

  129223. ** A structure to keep track of all of the column values that are fixed to

  129224. ** a known value due to WHERE clause constraints of the form COLUMN=VALUE.

  129225. */

  129226. typedef struct WhereConst WhereConst;

  129227. struct WhereConst {

  129228.   Parse *pParse;   /* Parsing context */

  129229.   int nConst;      /* Number for COLUMN=CONSTANT terms */

  129230.   int nChng;       /* Number of times a constant is propagated */

  129231.   Expr **apExpr;   /* [i*2] is COLUMN and [i*2+1] is VALUE */

  129232. };

  129233. 

  129234. /*

  129235. ** Add a new entry to the pConst object.  Except, do not add duplicate

  129236. ** pColumn entires.

  129237. */

  129238. static void constInsert(

  129239.   WhereConst *pConst,      /* The WhereConst into which we are inserting */

  129240.   Expr *pColumn,           /* The COLUMN part of the constraint */

  129241.   Expr *pValue             /* The VALUE part of the constraint */

  129242. ){

  129243.   int i;

  129244.   assert( pColumn->op==TK_COLUMN );

  129245. 

  129246.   /* 2018-10-25 ticket [cf5ed20f]

  129247.   ** Make sure the same pColumn is not inserted more than once */

  129248.   for(i=0; i<pConst->nConst; i++){

  129249.     const Expr *pExpr = pConst->apExpr[i*2];

  129250.     assert( pExpr->op==TK_COLUMN );

  129251.     if( pExpr->iTable==pColumn->iTable

  129252.      && pExpr->iColumn==pColumn->iColumn

  129253.     ){

  129254.       return;  /* Already present.  Return without doing anything. */

  129255.     }

  129256.   }

  129257. 

  129258.   pConst->nConst++;

  129259.   pConst->apExpr = sqlite3DbReallocOrFree(pConst->pParse->db, pConst->apExpr,

  129260.                          pConst->nConst*2*sizeof(Expr*));

  129261.   if( pConst->apExpr==0 ){

  129262.     pConst->nConst = 0;

  129263.   }else{

  129264.     if( ExprHasProperty(pValue, EP_FixedCol) ) pValue = pValue->pLeft;

  129265.     pConst->apExpr[pConst->nConst*2-2] = pColumn;

  129266.     pConst->apExpr[pConst->nConst*2-1] = pValue;

  129267.   }

  129268. }

  129269. 

  129270. /*

  129271. ** Find all terms of COLUMN=VALUE or VALUE=COLUMN in pExpr where VALUE

  129272. ** is a constant expression and where the term must be true because it

  129273. ** is part of the AND-connected terms of the expression.  For each term

  129274. ** found, add it to the pConst structure.

  129275. */

  129276. static void findConstInWhere(WhereConst *pConst, Expr *pExpr){

  129277.   Expr *pRight, *pLeft;

  129278.   if( pExpr==0 ) return;

  129279.   if( ExprHasProperty(pExpr, EP_FromJoin) ) return;

  129280.   if( pExpr->op==TK_AND ){

  129281.     findConstInWhere(pConst, pExpr->pRight);

  129282.     findConstInWhere(pConst, pExpr->pLeft);

  129283.     return;

  129284.   }

  129285.   if( pExpr->op!=TK_EQ ) return;

  129286.   pRight = pExpr->pRight;

  129287.   pLeft = pExpr->pLeft;

  129288.   assert( pRight!=0 );

  129289.   assert( pLeft!=0 );

  129290.   if( pRight->op==TK_COLUMN

  129291.    && !ExprHasProperty(pRight, EP_FixedCol)

  129292.    && sqlite3ExprIsConstant(pLeft)

  129293.    && sqlite3IsBinary(sqlite3BinaryCompareCollSeq(pConst->pParse,pLeft,pRight))

  129294.   ){

  129295.     constInsert(pConst, pRight, pLeft);

  129296.   }else

  129297.   if( pLeft->op==TK_COLUMN

  129298.    && !ExprHasProperty(pLeft, EP_FixedCol)

  129299.    && sqlite3ExprIsConstant(pRight)

  129300.    && sqlite3IsBinary(sqlite3BinaryCompareCollSeq(pConst->pParse,pLeft,pRight))

  129301.   ){

  129302.     constInsert(pConst, pLeft, pRight);

  129303.   }

  129304. }

  129305. 

  129306. /*

  129307. ** This is a Walker expression callback.  pExpr is a candidate expression

  129308. ** to be replaced by a value.  If pExpr is equivalent to one of the

  129309. ** columns named in pWalker->u.pConst, then overwrite it with its

  129310. ** corresponding value.

  129311. */

  129312. static int propagateConstantExprRewrite(Walker *pWalker, Expr *pExpr){

  129313.   int i;

  129314.   WhereConst *pConst;

  129315.   if( pExpr->op!=TK_COLUMN ) return WRC_Continue;

  129316.   if( ExprHasProperty(pExpr, EP_FixedCol) ) return WRC_Continue;

  129317.   pConst = pWalker->u.pConst;

  129318.   for(i=0; i<pConst->nConst; i++){

  129319.     Expr *pColumn = pConst->apExpr[i*2];

  129320.     if( pColumn==pExpr ) continue;

  129321.     if( pColumn->iTable!=pExpr->iTable ) continue;

  129322.     if( pColumn->iColumn!=pExpr->iColumn ) continue;

  129323.     /* A match is found.  Add the EP_FixedCol property */

  129324.     pConst->nChng++;

  129325.     ExprClearProperty(pExpr, EP_Leaf);

  129326.     ExprSetProperty(pExpr, EP_FixedCol);

  129327.     assert( pExpr->pLeft==0 );

  129328.     pExpr->pLeft = sqlite3ExprDup(pConst->pParse->db, pConst->apExpr[i*2+1], 0);

  129329.     break;

  129330.   }

  129331.   return WRC_Prune;

  129332. }

  129333. 

  129334. /*

  129335. ** The WHERE-clause constant propagation optimization.

  129336. **

  129337. ** If the WHERE clause contains terms of the form COLUMN=CONSTANT or

  129338. ** CONSTANT=COLUMN that must be tree (in other words, if the terms top-level

  129339. ** AND-connected terms that are not part of a ON clause from a LEFT JOIN)

  129340. ** then throughout the query replace all other occurrences of COLUMN

  129341. ** with CONSTANT within the WHERE clause.

  129342. **

  129343. ** For example, the query:

  129344. **

  129345. **      SELECT * FROM t1, t2, t3 WHERE t1.a=39 AND t2.b=t1.a AND t3.c=t2.b

  129346. **

  129347. ** Is transformed into

  129348. **

  129349. **      SELECT * FROM t1, t2, t3 WHERE t1.a=39 AND t2.b=39 AND t3.c=39

  129350. **

  129351. ** Return true if any transformations where made and false if not.

  129352. **

  129353. ** Implementation note:  Constant propagation is tricky due to affinity

  129354. ** and collating sequence interactions.  Consider this example:

  129355. **

  129356. **    CREATE TABLE t1(a INT,b TEXT);

  129357. **    INSERT INTO t1 VALUES(123,'0123');

  129358. **    SELECT * FROM t1 WHERE a=123 AND b=a;

  129359. **    SELECT * FROM t1 WHERE a=123 AND b=123;

  129360. **

  129361. ** The two SELECT statements above should return different answers.  b=a

  129362. ** is alway true because the comparison uses numeric affinity, but b=123

  129363. ** is false because it uses text affinity and '0123' is not the same as '123'.

  129364. ** To work around this, the expression tree is not actually changed from

  129365. ** "b=a" to "b=123" but rather the "a" in "b=a" is tagged with EP_FixedCol

  129366. ** and the "123" value is hung off of the pLeft pointer.  Code generator

  129367. ** routines know to generate the constant "123" instead of looking up the

  129368. ** column value.  Also, to avoid collation problems, this optimization is

  129369. ** only attempted if the "a=123" term uses the default BINARY collation.

  129370. */

  129371. static int propagateConstants(

  129372.   Parse *pParse,   /* The parsing context */

  129373.   Select *p        /* The query in which to propagate constants */

  129374. ){

  129375.   WhereConst x;

  129376.   Walker w;

  129377.   int nChng = 0;

  129378.   x.pParse = pParse;

  129379.   do{

  129380.     x.nConst = 0;

  129381.     x.nChng = 0;

  129382.     x.apExpr = 0;

  129383.     findConstInWhere(&x, p->pWhere);

  129384.     if( x.nConst ){

  129385.       memset(&w, 0, sizeof(w));

  129386.       w.pParse = pParse;

  129387.       w.xExprCallback = propagateConstantExprRewrite;

  129388.       w.xSelectCallback = sqlite3SelectWalkNoop;

  129389.       w.xSelectCallback2 = 0;

  129390.       w.walkerDepth = 0;

  129391.       w.u.pConst = &x;

  129392.       sqlite3WalkExpr(&w, p->pWhere);

  129393.       sqlite3DbFree(x.pParse->db, x.apExpr);

  129394.       nChng += x.nChng;

  129395.     }

  129396.   }while( x.nChng );  

  129397.   return nChng;

  129398. }

  129399. 

  129400. #if !defined(SQLITE_OMIT_SUBQUERY) || !defined(SQLITE_OMIT_VIEW)

  129401. /*

  129402. ** Make copies of relevant WHERE clause terms of the outer query into

  129403. ** the WHERE clause of subquery.  Example:

  129404. **

  129405. **    SELECT * FROM (SELECT a AS x, c-d AS y FROM t1) WHERE x=5 AND y=10;

  129406. **

  129407. ** Transformed into:

  129408. **

  129409. **    SELECT * FROM (SELECT a AS x, c-d AS y FROM t1 WHERE a=5 AND c-d=10)

  129410. **     WHERE x=5 AND y=10;

  129411. **

  129412. ** The hope is that the terms added to the inner query will make it more

  129413. ** efficient.

  129414. **

  129415. ** Do not attempt this optimization if:

  129416. **

  129417. **   (1) (** This restriction was removed on 2017-09-29.  We used to

  129418. **           disallow this optimization for aggregate subqueries, but now

  129419. **           it is allowed by putting the extra terms on the HAVING clause.

  129420. **           The added HAVING clause is pointless if the subquery lacks

  129421. **           a GROUP BY clause.  But such a HAVING clause is also harmless

  129422. **           so there does not appear to be any reason to add extra logic

  129423. **           to suppress it. **)

  129424. **

  129425. **   (2) The inner query is the recursive part of a common table expression.

  129426. **

  129427. **   (3) The inner query has a LIMIT clause (since the changes to the WHERE

  129428. **       clause would change the meaning of the LIMIT).

  129429. **

  129430. **   (4) The inner query is the right operand of a LEFT JOIN and the

  129431. **       expression to be pushed down does not come from the ON clause

  129432. **       on that LEFT JOIN.

  129433. **

  129434. **   (5) The WHERE clause expression originates in the ON or USING clause

  129435. **       of a LEFT JOIN where iCursor is not the right-hand table of that

  129436. **       left join.  An example:

  129437. **

  129438. **           SELECT *

  129439. **           FROM (SELECT 1 AS a1 UNION ALL SELECT 2) AS aa

  129440. **           JOIN (SELECT 1 AS b2 UNION ALL SELECT 2) AS bb ON (a1=b2)

  129441. **           LEFT JOIN (SELECT 8 AS c3 UNION ALL SELECT 9) AS cc ON (b2=2);

  129442. **

  129443. **       The correct answer is three rows:  (1,1,NULL),(2,2,8),(2,2,9).

  129444. **       But if the (b2=2) term were to be pushed down into the bb subquery,

  129445. **       then the (1,1,NULL) row would be suppressed.

  129446. **

  129447. **   (6) The inner query features one or more window-functions (since 

  129448. **       changes to the WHERE clause of the inner query could change the 

  129449. **       window over which window functions are calculated).

  129450. **

  129451. ** Return 0 if no changes are made and non-zero if one or more WHERE clause

  129452. ** terms are duplicated into the subquery.

  129453. */

  129454. static int pushDownWhereTerms(

  129455.   Parse *pParse,        /* Parse context (for malloc() and error reporting) */

  129456.   Select *pSubq,        /* The subquery whose WHERE clause is to be augmented */

  129457.   Expr *pWhere,         /* The WHERE clause of the outer query */

  129458.   int iCursor,          /* Cursor number of the subquery */

  129459.   int isLeftJoin        /* True if pSubq is the right term of a LEFT JOIN */

  129460. ){

  129461.   Expr *pNew;

  129462.   int nChng = 0;

  129463.   if( pWhere==0 ) return 0;

  129464.   if( pSubq->selFlags & SF_Recursive ) return 0;  /* restriction (2) */

  129465. 

  129466. #ifndef SQLITE_OMIT_WINDOWFUNC

  129467.   if( pSubq->pWin ) return 0;    /* restriction (6) */

  129468. #endif

  129469. 

  129470. #ifdef SQLITE_DEBUG

  129471.   /* Only the first term of a compound can have a WITH clause.  But make

  129472.   ** sure no other terms are marked SF_Recursive in case something changes

  129473.   ** in the future.

  129474.   */

  129475.   {

  129476.     Select *pX;  

  129477.     for(pX=pSubq; pX; pX=pX->pPrior){

  129478.       assert( (pX->selFlags & (SF_Recursive))==0 );

  129479.     }

  129480.   }

  129481. #endif

  129482. 

  129483.   if( pSubq->pLimit!=0 ){

  129484.     return 0; /* restriction (3) */

  129485.   }

  129486.   while( pWhere->op==TK_AND ){

  129487.     nChng += pushDownWhereTerms(pParse, pSubq, pWhere->pRight,

  129488.                                 iCursor, isLeftJoin);

  129489.     pWhere = pWhere->pLeft;

  129490.   }

  129491.   if( isLeftJoin

  129492.    && (ExprHasProperty(pWhere,EP_FromJoin)==0

  129493.          || pWhere->iRightJoinTable!=iCursor)

  129494.   ){

  129495.     return 0; /* restriction (4) */

  129496.   }

  129497.   if( ExprHasProperty(pWhere,EP_FromJoin) && pWhere->iRightJoinTable!=iCursor ){

  129498.     return 0; /* restriction (5) */

  129499.   }

  129500.   if( sqlite3ExprIsTableConstant(pWhere, iCursor) ){

  129501.     nChng++;

  129502.     while( pSubq ){

  129503.       SubstContext x;

  129504.       pNew = sqlite3ExprDup(pParse->db, pWhere, 0);

  129505.       unsetJoinExpr(pNew, -1);

  129506.       x.pParse = pParse;

  129507.       x.iTable = iCursor;

  129508.       x.iNewTable = iCursor;

  129509.       x.isLeftJoin = 0;

  129510.       x.pEList = pSubq->pEList;

  129511.       pNew = substExpr(&x, pNew);

  129512.       if( pSubq->selFlags & SF_Aggregate ){

  129513.         pSubq->pHaving = sqlite3ExprAnd(pParse, pSubq->pHaving, pNew);

  129514.       }else{

  129515.         pSubq->pWhere = sqlite3ExprAnd(pParse, pSubq->pWhere, pNew);

  129516.       }

  129517.       pSubq = pSubq->pPrior;

  129518.     }

  129519.   }

  129520.   return nChng;

  129521. }

  129522. #endif /* !defined(SQLITE_OMIT_SUBQUERY) || !defined(SQLITE_OMIT_VIEW) */

  129523. 

  129524. /*

  129525. ** The pFunc is the only aggregate function in the query.  Check to see

  129526. ** if the query is a candidate for the min/max optimization. 

  129527. **

  129528. ** If the query is a candidate for the min/max optimization, then set

  129529. ** *ppMinMax to be an ORDER BY clause to be used for the optimization

  129530. ** and return either WHERE_ORDERBY_MIN or WHERE_ORDERBY_MAX depending on

  129531. ** whether pFunc is a min() or max() function.

  129532. **

  129533. ** If the query is not a candidate for the min/max optimization, return

  129534. ** WHERE_ORDERBY_NORMAL (which must be zero).

  129535. **

  129536. ** This routine must be called after aggregate functions have been

  129537. ** located but before their arguments have been subjected to aggregate

  129538. ** analysis.

  129539. */

  129540. static u8 minMaxQuery(sqlite3 *db, Expr *pFunc, ExprList **ppMinMax){

  129541.   int eRet = WHERE_ORDERBY_NORMAL;      /* Return value */

  129542.   ExprList *pEList = pFunc->x.pList;    /* Arguments to agg function */

  129543.   const char *zFunc;                    /* Name of aggregate function pFunc */

  129544.   ExprList *pOrderBy;

  129545.   u8 sortOrder;

  129546. 

  129547.   assert( *ppMinMax==0 );

  129548.   assert( pFunc->op==TK_AGG_FUNCTION );

  129549.   if( pEList==0 || pEList->nExpr!=1 ) return eRet;

  129550.   zFunc = pFunc->u.zToken;

  129551.   if( sqlite3StrICmp(zFunc, "min")==0 ){

  129552.     eRet = WHERE_ORDERBY_MIN;

  129553.     sortOrder = SQLITE_SO_ASC;

  129554.   }else if( sqlite3StrICmp(zFunc, "max")==0 ){

  129555.     eRet = WHERE_ORDERBY_MAX;

  129556.     sortOrder = SQLITE_SO_DESC;

  129557.   }else{

  129558.     return eRet;

  129559.   }

  129560.   *ppMinMax = pOrderBy = sqlite3ExprListDup(db, pEList, 0);

  129561.   assert( pOrderBy!=0 || db->mallocFailed );

  129562.   if( pOrderBy ) pOrderBy->a[0].sortOrder = sortOrder;

  129563.   return eRet;

  129564. }

  129565. 

  129566. /*

  129567. ** The select statement passed as the first argument is an aggregate query.

  129568. ** The second argument is the associated aggregate-info object. This 

  129569. ** function tests if the SELECT is of the form:

  129570. **

  129571. **   SELECT count(*) FROM <tbl>

  129572. **

  129573. ** where table is a database table, not a sub-select or view. If the query

  129574. ** does match this pattern, then a pointer to the Table object representing

  129575. ** <tbl> is returned. Otherwise, 0 is returned.

  129576. */

  129577. static Table *isSimpleCount(Select *p, AggInfo *pAggInfo){

  129578.   Table *pTab;

  129579.   Expr *pExpr;

  129580. 

  129581.   assert( !p->pGroupBy );

  129582. 

  129583.   if( p->pWhere || p->pEList->nExpr!=1 

  129584.    || p->pSrc->nSrc!=1 || p->pSrc->a[0].pSelect

  129585.   ){

  129586.     return 0;

  129587.   }

  129588.   pTab = p->pSrc->a[0].pTab;

  129589.   pExpr = p->pEList->a[0].pExpr;

  129590.   assert( pTab && !pTab->pSelect && pExpr );

  129591. 

  129592.   if( IsVirtual(pTab) ) return 0;

  129593.   if( pExpr->op!=TK_AGG_FUNCTION ) return 0;

  129594.   if( NEVER(pAggInfo->nFunc==0) ) return 0;

  129595.   if( (pAggInfo->aFunc[0].pFunc->funcFlags&SQLITE_FUNC_COUNT)==0 ) return 0;

  129596.   if( pExpr->flags&EP_Distinct ) return 0;

  129597. 

  129598.   return pTab;

  129599. }

  129600. 

  129601. /*

  129602. ** If the source-list item passed as an argument was augmented with an

  129603. ** INDEXED BY clause, then try to locate the specified index. If there

  129604. ** was such a clause and the named index cannot be found, return 

  129605. ** SQLITE_ERROR and leave an error in pParse. Otherwise, populate 

  129606. ** pFrom->pIndex and return SQLITE_OK.

  129607. */

  129608. SQLITE_PRIVATE int sqlite3IndexedByLookup(Parse *pParse, struct SrcList_item *pFrom){

  129609.   if( pFrom->pTab && pFrom->fg.isIndexedBy ){

  129610.     Table *pTab = pFrom->pTab;

  129611.     char *zIndexedBy = pFrom->u1.zIndexedBy;

  129612.     Index *pIdx;

  129613.     for(pIdx=pTab->pIndex; 

  129614.         pIdx && sqlite3StrICmp(pIdx->zName, zIndexedBy); 

  129615.         pIdx=pIdx->pNext

  129616.     );

  129617.     if( !pIdx ){

  129618.       sqlite3ErrorMsg(pParse, "no such index: %s", zIndexedBy, 0);

  129619.       pParse->checkSchema = 1;

  129620.       return SQLITE_ERROR;

  129621.     }

  129622.     pFrom->pIBIndex = pIdx;

  129623.   }

  129624.   return SQLITE_OK;

  129625. }

  129626. /*

  129627. ** Detect compound SELECT statements that use an ORDER BY clause with 

  129628. ** an alternative collating sequence.

  129629. **

  129630. **    SELECT ... FROM t1 EXCEPT SELECT ... FROM t2 ORDER BY .. COLLATE ...

  129631. **

  129632. ** These are rewritten as a subquery:

  129633. **

  129634. **    SELECT * FROM (SELECT ... FROM t1 EXCEPT SELECT ... FROM t2)

  129635. **     ORDER BY ... COLLATE ...

  129636. **

  129637. ** This transformation is necessary because the multiSelectOrderBy() routine

  129638. ** above that generates the code for a compound SELECT with an ORDER BY clause

  129639. ** uses a merge algorithm that requires the same collating sequence on the

  129640. ** result columns as on the ORDER BY clause.  See ticket

  129641. ** http://www.sqlite.org/src/info/6709574d2a

  129642. **

  129643. ** This transformation is only needed for EXCEPT, INTERSECT, and UNION.

  129644. ** The UNION ALL operator works fine with multiSelectOrderBy() even when

  129645. ** there are COLLATE terms in the ORDER BY.

  129646. */

  129647. static int convertCompoundSelectToSubquery(Walker *pWalker, Select *p){

  129648.   int i;

  129649.   Select *pNew;

  129650.   Select *pX;

  129651.   sqlite3 *db;

  129652.   struct ExprList_item *a;

  129653.   SrcList *pNewSrc;

  129654.   Parse *pParse;

  129655.   Token dummy;

  129656. 

  129657.   if( p->pPrior==0 ) return WRC_Continue;

  129658.   if( p->pOrderBy==0 ) return WRC_Continue;

  129659.   for(pX=p; pX && (pX->op==TK_ALL || pX->op==TK_SELECT); pX=pX->pPrior){}

  129660.   if( pX==0 ) return WRC_Continue;

  129661.   a = p->pOrderBy->a;

  129662.   for(i=p->pOrderBy->nExpr-1; i>=0; i--){

  129663.     if( a[i].pExpr->flags & EP_Collate ) break;

  129664.   }

  129665.   if( i<0 ) return WRC_Continue;

  129666. 

  129667.   /* If we reach this point, that means the transformation is required. */

  129668. 

  129669.   pParse = pWalker->pParse;

  129670.   db = pParse->db;

  129671.   pNew = sqlite3DbMallocZero(db, sizeof(*pNew) );

  129672.   if( pNew==0 ) return WRC_Abort;

  129673.   memset(&dummy, 0, sizeof(dummy));

  129674.   pNewSrc = sqlite3SrcListAppendFromTerm(pParse,0,0,0,&dummy,pNew,0,0);

  129675.   if( pNewSrc==0 ) return WRC_Abort;

  129676.   *pNew = *p;

  129677.   p->pSrc = pNewSrc;

  129678.   p->pEList = sqlite3ExprListAppend(pParse, 0, sqlite3Expr(db, TK_ASTERISK, 0));

  129679.   p->op = TK_SELECT;

  129680.   p->pWhere = 0;

  129681.   pNew->pGroupBy = 0;

  129682.   pNew->pHaving = 0;

  129683.   pNew->pOrderBy = 0;

  129684.   p->pPrior = 0;

  129685.   p->pNext = 0;

  129686.   p->pWith = 0;

  129687.   p->selFlags &= ~SF_Compound;

  129688.   assert( (p->selFlags & SF_Converted)==0 );

  129689.   p->selFlags |= SF_Converted;

  129690.   assert( pNew->pPrior!=0 );

  129691.   pNew->pPrior->pNext = pNew;

  129692.   pNew->pLimit = 0;

  129693.   return WRC_Continue;

  129694. }

  129695. 

  129696. /*

  129697. ** Check to see if the FROM clause term pFrom has table-valued function

  129698. ** arguments.  If it does, leave an error message in pParse and return

  129699. ** non-zero, since pFrom is not allowed to be a table-valued function.

  129700. */

  129701. static int cannotBeFunction(Parse *pParse, struct SrcList_item *pFrom){

  129702.   if( pFrom->fg.isTabFunc ){

  129703.     sqlite3ErrorMsg(pParse, "'%s' is not a function", pFrom->zName);

  129704.     return 1;

  129705.   }

  129706.   return 0;

  129707. }

  129708. 

  129709. #ifndef SQLITE_OMIT_CTE

  129710. /*

  129711. ** Argument pWith (which may be NULL) points to a linked list of nested 

  129712. ** WITH contexts, from inner to outermost. If the table identified by 

  129713. ** FROM clause element pItem is really a common-table-expression (CTE) 

  129714. ** then return a pointer to the CTE definition for that table. Otherwise

  129715. ** return NULL.

  129716. **

  129717. ** If a non-NULL value is returned, set *ppContext to point to the With

  129718. ** object that the returned CTE belongs to.

  129719. */

  129720. static struct Cte *searchWith(

  129721.   With *pWith,                    /* Current innermost WITH clause */

  129722.   struct SrcList_item *pItem,     /* FROM clause element to resolve */

  129723.   With **ppContext                /* OUT: WITH clause return value belongs to */

  129724. ){

  129725.   const char *zName;

  129726.   if( pItem->zDatabase==0 && (zName = pItem->zName)!=0 ){

  129727.     With *p;

  129728.     for(p=pWith; p; p=p->pOuter){

  129729.       int i;

  129730.       for(i=0; i<p->nCte; i++){

  129731.         if( sqlite3StrICmp(zName, p->a[i].zName)==0 ){

  129732.           *ppContext = p;

  129733.           return &p->a[i];

  129734.         }

  129735.       }

  129736.     }

  129737.   }

  129738.   return 0;

  129739. }

  129740. 

  129741. /* The code generator maintains a stack of active WITH clauses

  129742. ** with the inner-most WITH clause being at the top of the stack.

  129743. **

  129744. ** This routine pushes the WITH clause passed as the second argument

  129745. ** onto the top of the stack. If argument bFree is true, then this

  129746. ** WITH clause will never be popped from the stack. In this case it

  129747. ** should be freed along with the Parse object. In other cases, when

  129748. ** bFree==0, the With object will be freed along with the SELECT 

  129749. ** statement with which it is associated.

  129750. */

  129751. SQLITE_PRIVATE void sqlite3WithPush(Parse *pParse, With *pWith, u8 bFree){

  129752.   assert( bFree==0 || (pParse->pWith==0 && pParse->pWithToFree==0) );

  129753.   if( pWith ){

  129754.     assert( pParse->pWith!=pWith );

  129755.     pWith->pOuter = pParse->pWith;

  129756.     pParse->pWith = pWith;

  129757.     if( bFree ) pParse->pWithToFree = pWith;

  129758.   }

  129759. }

  129760. 

  129761. /*

  129762. ** This function checks if argument pFrom refers to a CTE declared by 

  129763. ** a WITH clause on the stack currently maintained by the parser. And,

  129764. ** if currently processing a CTE expression, if it is a recursive

  129765. ** reference to the current CTE.

  129766. **

  129767. ** If pFrom falls into either of the two categories above, pFrom->pTab

  129768. ** and other fields are populated accordingly. The caller should check

  129769. ** (pFrom->pTab!=0) to determine whether or not a successful match

  129770. ** was found.

  129771. **

  129772. ** Whether or not a match is found, SQLITE_OK is returned if no error

  129773. ** occurs. If an error does occur, an error message is stored in the

  129774. ** parser and some error code other than SQLITE_OK returned.

  129775. */

  129776. static int withExpand(

  129777.   Walker *pWalker, 

  129778.   struct SrcList_item *pFrom

  129779. ){

  129780.   Parse *pParse = pWalker->pParse;

  129781.   sqlite3 *db = pParse->db;

  129782.   struct Cte *pCte;               /* Matched CTE (or NULL if no match) */

  129783.   With *pWith;                    /* WITH clause that pCte belongs to */

  129784. 

  129785.   assert( pFrom->pTab==0 );

  129786. 

  129787.   pCte = searchWith(pParse->pWith, pFrom, &pWith);

  129788.   if( pCte ){

  129789.     Table *pTab;

  129790.     ExprList *pEList;

  129791.     Select *pSel;

  129792.     Select *pLeft;                /* Left-most SELECT statement */

  129793.     int bMayRecursive;            /* True if compound joined by UNION [ALL] */

  129794.     With *pSavedWith;             /* Initial value of pParse->pWith */

  129795. 

  129796.     /* If pCte->zCteErr is non-NULL at this point, then this is an illegal

  129797.     ** recursive reference to CTE pCte. Leave an error in pParse and return

  129798.     ** early. If pCte->zCteErr is NULL, then this is not a recursive reference.

  129799.     ** In this case, proceed.  */

  129800.     if( pCte->zCteErr ){

  129801.       sqlite3ErrorMsg(pParse, pCte->zCteErr, pCte->zName);

  129802.       return SQLITE_ERROR;

  129803.     }

  129804.     if( cannotBeFunction(pParse, pFrom) ) return SQLITE_ERROR;

  129805. 

  129806.     assert( pFrom->pTab==0 );

  129807.     pFrom->pTab = pTab = sqlite3DbMallocZero(db, sizeof(Table));

  129808.     if( pTab==0 ) return WRC_Abort;

  129809.     pTab->nTabRef = 1;

  129810.     pTab->zName = sqlite3DbStrDup(db, pCte->zName);

  129811.     pTab->iPKey = -1;

  129812.     pTab->nRowLogEst = 200; assert( 200==sqlite3LogEst(1048576) );

  129813.     pTab->tabFlags |= TF_Ephemeral | TF_NoVisibleRowid;

  129814.     pFrom->pSelect = sqlite3SelectDup(db, pCte->pSelect, 0);

  129815.     if( db->mallocFailed ) return SQLITE_NOMEM_BKPT;

  129816.     assert( pFrom->pSelect );

  129817. 

  129818.     /* Check if this is a recursive CTE. */

  129819.     pSel = pFrom->pSelect;

  129820.     bMayRecursive = ( pSel->op==TK_ALL || pSel->op==TK_UNION );

  129821.     if( bMayRecursive ){

  129822.       int i;

  129823.       SrcList *pSrc = pFrom->pSelect->pSrc;

  129824.       for(i=0; i<pSrc->nSrc; i++){

  129825.         struct SrcList_item *pItem = &pSrc->a[i];

  129826.         if( pItem->zDatabase==0 

  129827.          && pItem->zName!=0 

  129828.          && 0==sqlite3StrICmp(pItem->zName, pCte->zName)

  129829.           ){

  129830.           pItem->pTab = pTab;

  129831.           pItem->fg.isRecursive = 1;

  129832.           pTab->nTabRef++;

  129833.           pSel->selFlags |= SF_Recursive;

  129834.         }

  129835.       }

  129836.     }

  129837. 

  129838.     /* Only one recursive reference is permitted. */ 

  129839.     if( pTab->nTabRef>2 ){

  129840.       sqlite3ErrorMsg(

  129841.           pParse, "multiple references to recursive table: %s", pCte->zName

  129842.       );

  129843.       return SQLITE_ERROR;

  129844.     }

  129845.     assert( pTab->nTabRef==1 || 

  129846.             ((pSel->selFlags&SF_Recursive) && pTab->nTabRef==2 ));

  129847. 

  129848.     pCte->zCteErr = "circular reference: %s";

  129849.     pSavedWith = pParse->pWith;

  129850.     pParse->pWith = pWith;

  129851.     if( bMayRecursive ){

  129852.       Select *pPrior = pSel->pPrior;

  129853.       assert( pPrior->pWith==0 );

  129854.       pPrior->pWith = pSel->pWith;

  129855.       sqlite3WalkSelect(pWalker, pPrior);

  129856.       pPrior->pWith = 0;

  129857.     }else{

  129858.       sqlite3WalkSelect(pWalker, pSel);

  129859.     }

  129860.     pParse->pWith = pWith;

  129861. 

  129862.     for(pLeft=pSel; pLeft->pPrior; pLeft=pLeft->pPrior);

  129863.     pEList = pLeft->pEList;

  129864.     if( pCte->pCols ){

  129865.       if( pEList && pEList->nExpr!=pCte->pCols->nExpr ){

  129866.         sqlite3ErrorMsg(pParse, "table %s has %d values for %d columns",

  129867.             pCte->zName, pEList->nExpr, pCte->pCols->nExpr

  129868.         );

  129869.         pParse->pWith = pSavedWith;

  129870.         return SQLITE_ERROR;

  129871.       }

  129872.       pEList = pCte->pCols;

  129873.     }

  129874. 

  129875.     sqlite3ColumnsFromExprList(pParse, pEList, &pTab->nCol, &pTab->aCol);

  129876.     if( bMayRecursive ){

  129877.       if( pSel->selFlags & SF_Recursive ){

  129878.         pCte->zCteErr = "multiple recursive references: %s";

  129879.       }else{

  129880.         pCte->zCteErr = "recursive reference in a subquery: %s";

  129881.       }

  129882.       sqlite3WalkSelect(pWalker, pSel);

  129883.     }

  129884.     pCte->zCteErr = 0;

  129885.     pParse->pWith = pSavedWith;

  129886.   }

  129887. 

  129888.   return SQLITE_OK;

  129889. }

  129890. #endif

  129891. 

  129892. #ifndef SQLITE_OMIT_CTE

  129893. /*

  129894. ** If the SELECT passed as the second argument has an associated WITH 

  129895. ** clause, pop it from the stack stored as part of the Parse object.

  129896. **

  129897. ** This function is used as the xSelectCallback2() callback by

  129898. ** sqlite3SelectExpand() when walking a SELECT tree to resolve table

  129899. ** names and other FROM clause elements. 

  129900. */

  129901. static void selectPopWith(Walker *pWalker, Select *p){

  129902.   Parse *pParse = pWalker->pParse;

  129903.   if( OK_IF_ALWAYS_TRUE(pParse->pWith) && p->pPrior==0 ){

  129904.     With *pWith = findRightmost(p)->pWith;

  129905.     if( pWith!=0 ){

  129906.       assert( pParse->pWith==pWith );

  129907.       pParse->pWith = pWith->pOuter;

  129908.     }

  129909.   }

  129910. }

  129911. #else

  129912. #define selectPopWith 0

  129913. #endif

  129914. 

  129915. /*

  129916. ** The SrcList_item structure passed as the second argument represents a

  129917. ** sub-query in the FROM clause of a SELECT statement. This function

  129918. ** allocates and populates the SrcList_item.pTab object. If successful,

  129919. ** SQLITE_OK is returned. Otherwise, if an OOM error is encountered,

  129920. ** SQLITE_NOMEM.

  129921. */

  129922. SQLITE_PRIVATE int sqlite3ExpandSubquery(Parse *pParse, struct SrcList_item *pFrom){

  129923.   Select *pSel = pFrom->pSelect;

  129924.   Table *pTab;

  129925. 

  129926.   assert( pSel );

  129927.   pFrom->pTab = pTab = sqlite3DbMallocZero(pParse->db, sizeof(Table));

  129928.   if( pTab==0 ) return SQLITE_NOMEM;

  129929.   pTab->nTabRef = 1;

  129930.   if( pFrom->zAlias ){

  129931.     pTab->zName = sqlite3DbStrDup(pParse->db, pFrom->zAlias);

  129932.   }else{

  129933.     pTab->zName = sqlite3MPrintf(pParse->db, "subquery_%u", pSel->selId);

  129934.   }

  129935.   while( pSel->pPrior ){ pSel = pSel->pPrior; }

  129936.   sqlite3ColumnsFromExprList(pParse, pSel->pEList,&pTab->nCol,&pTab->aCol);

  129937.   pTab->iPKey = -1;

  129938.   pTab->nRowLogEst = 200; assert( 200==sqlite3LogEst(1048576) );

  129939.   pTab->tabFlags |= TF_Ephemeral;

  129940. 

  129941.   return pParse->nErr ? SQLITE_ERROR : SQLITE_OK;

  129942. }

  129943. 

  129944. /*

  129945. ** This routine is a Walker callback for "expanding" a SELECT statement.

  129946. ** "Expanding" means to do the following:

  129947. **

  129948. **    (1)  Make sure VDBE cursor numbers have been assigned to every

  129949. **         element of the FROM clause.

  129950. **

  129951. **    (2)  Fill in the pTabList->a[].pTab fields in the SrcList that 

  129952. **         defines FROM clause.  When views appear in the FROM clause,

  129953. **         fill pTabList->a[].pSelect with a copy of the SELECT statement

  129954. **         that implements the view.  A copy is made of the view's SELECT

  129955. **         statement so that we can freely modify or delete that statement

  129956. **         without worrying about messing up the persistent representation

  129957. **         of the view.

  129958. **

  129959. **    (3)  Add terms to the WHERE clause to accommodate the NATURAL keyword

  129960. **         on joins and the ON and USING clause of joins.

  129961. **

  129962. **    (4)  Scan the list of columns in the result set (pEList) looking

  129963. **         for instances of the "*" operator or the TABLE.* operator.

  129964. **         If found, expand each "*" to be every column in every table

  129965. **         and TABLE.* to be every column in TABLE.

  129966. **

  129967. */

  129968. static int selectExpander(Walker *pWalker, Select *p){

  129969.   Parse *pParse = pWalker->pParse;

  129970.   int i, j, k;

  129971.   SrcList *pTabList;

  129972.   ExprList *pEList;

  129973.   struct SrcList_item *pFrom;

  129974.   sqlite3 *db = pParse->db;

  129975.   Expr *pE, *pRight, *pExpr;

  129976.   u16 selFlags = p->selFlags;

  129977.   u32 elistFlags = 0;

  129978. 

  129979.   p->selFlags |= SF_Expanded;

  129980.   if( db->mallocFailed  ){

  129981.     return WRC_Abort;

  129982.   }

  129983.   assert( p->pSrc!=0 );

  129984.   if( (selFlags & SF_Expanded)!=0 ){

  129985.     return WRC_Prune;

  129986.   }

  129987.   if( pWalker->eCode ){

  129988.     /* Renumber selId because it has been copied from a view */

  129989.     p->selId = ++pParse->nSelect;

  129990.   }

  129991.   pTabList = p->pSrc;

  129992.   pEList = p->pEList;

  129993.   sqlite3WithPush(pParse, p->pWith, 0);

  129994. 

  129995.   /* Make sure cursor numbers have been assigned to all entries in

  129996.   ** the FROM clause of the SELECT statement.

  129997.   */

  129998.   sqlite3SrcListAssignCursors(pParse, pTabList);

  129999. 

  130000.   /* Look up every table named in the FROM clause of the select.  If

  130001.   ** an entry of the FROM clause is a subquery instead of a table or view,

  130002.   ** then create a transient table structure to describe the subquery.

  130003.   */

  130004.   for(i=0, pFrom=pTabList->a; i<pTabList->nSrc; i++, pFrom++){

  130005.     Table *pTab;

  130006.     assert( pFrom->fg.isRecursive==0 || pFrom->pTab!=0 );

  130007.     if( pFrom->fg.isRecursive ) continue;

  130008.     assert( pFrom->pTab==0 );

  130009. #ifndef SQLITE_OMIT_CTE

  130010.     if( withExpand(pWalker, pFrom) ) return WRC_Abort;

  130011.     if( pFrom->pTab ) {} else

  130012. #endif

  130013.     if( pFrom->zName==0 ){

  130014. #ifndef SQLITE_OMIT_SUBQUERY

  130015.       Select *pSel = pFrom->pSelect;

  130016.       /* A sub-query in the FROM clause of a SELECT */

  130017.       assert( pSel!=0 );

  130018.       assert( pFrom->pTab==0 );

  130019.       if( sqlite3WalkSelect(pWalker, pSel) ) return WRC_Abort;

  130020.       if( sqlite3ExpandSubquery(pParse, pFrom) ) return WRC_Abort;

  130021. #endif

  130022.     }else{

  130023.       /* An ordinary table or view name in the FROM clause */

  130024.       assert( pFrom->pTab==0 );

  130025.       pFrom->pTab = pTab = sqlite3LocateTableItem(pParse, 0, pFrom);

  130026.       if( pTab==0 ) return WRC_Abort;

  130027.       if( pTab->nTabRef>=0xffff ){

  130028.         sqlite3ErrorMsg(pParse, "too many references to \"%s\": max 65535",

  130029.            pTab->zName);

  130030.         pFrom->pTab = 0;

  130031.         return WRC_Abort;

  130032.       }

  130033.       pTab->nTabRef++;

  130034.       if( !IsVirtual(pTab) && cannotBeFunction(pParse, pFrom) ){

  130035.         return WRC_Abort;

  130036.       }

  130037. #if !defined(SQLITE_OMIT_VIEW) || !defined (SQLITE_OMIT_VIRTUALTABLE)

  130038.       if( IsVirtual(pTab) || pTab->pSelect ){

  130039.         i16 nCol;

  130040.         u8 eCodeOrig = pWalker->eCode;

  130041.         if( sqlite3ViewGetColumnNames(pParse, pTab) ) return WRC_Abort;

  130042.         assert( pFrom->pSelect==0 );

  130043.         pFrom->pSelect = sqlite3SelectDup(db, pTab->pSelect, 0);

  130044.         nCol = pTab->nCol;

  130045.         pTab->nCol = -1;

  130046.         pWalker->eCode = 1;  /* Turn on Select.selId renumbering */

  130047.         sqlite3WalkSelect(pWalker, pFrom->pSelect);

  130048.         pWalker->eCode = eCodeOrig;

  130049.         pTab->nCol = nCol;

  130050.       }

  130051. #endif

  130052.     }

  130053. 

  130054.     /* Locate the index named by the INDEXED BY clause, if any. */

  130055.     if( sqlite3IndexedByLookup(pParse, pFrom) ){

  130056.       return WRC_Abort;

  130057.     }

  130058.   }

  130059. 

  130060.   /* Process NATURAL keywords, and ON and USING clauses of joins.

  130061.   */

  130062.   if( db->mallocFailed || sqliteProcessJoin(pParse, p) ){

  130063.     return WRC_Abort;

  130064.   }

  130065. 

  130066.   /* For every "*" that occurs in the column list, insert the names of

  130067.   ** all columns in all tables.  And for every TABLE.* insert the names

  130068.   ** of all columns in TABLE.  The parser inserted a special expression

  130069.   ** with the TK_ASTERISK operator for each "*" that it found in the column

  130070.   ** list.  The following code just has to locate the TK_ASTERISK

  130071.   ** expressions and expand each one to the list of all columns in

  130072.   ** all tables.

  130073.   **

  130074.   ** The first loop just checks to see if there are any "*" operators

  130075.   ** that need expanding.

  130076.   */

  130077.   for(k=0; k<pEList->nExpr; k++){

  130078.     pE = pEList->a[k].pExpr;

  130079.     if( pE->op==TK_ASTERISK ) break;

  130080.     assert( pE->op!=TK_DOT || pE->pRight!=0 );

  130081.     assert( pE->op!=TK_DOT || (pE->pLeft!=0 && pE->pLeft->op==TK_ID) );

  130082.     if( pE->op==TK_DOT && pE->pRight->op==TK_ASTERISK ) break;

  130083.     elistFlags |= pE->flags;

  130084.   }

  130085.   if( k<pEList->nExpr ){

  130086.     /*

  130087.     ** If we get here it means the result set contains one or more "*"

  130088.     ** operators that need to be expanded.  Loop through each expression

  130089.     ** in the result set and expand them one by one.

  130090.     */

  130091.     struct ExprList_item *a = pEList->a;

  130092.     ExprList *pNew = 0;

  130093.     int flags = pParse->db->flags;

  130094.     int longNames = (flags & SQLITE_FullColNames)!=0

  130095.                       && (flags & SQLITE_ShortColNames)==0;

  130096. 

  130097.     for(k=0; k<pEList->nExpr; k++){

  130098.       pE = a[k].pExpr;

  130099.       elistFlags |= pE->flags;

  130100.       pRight = pE->pRight;

  130101.       assert( pE->op!=TK_DOT || pRight!=0 );

  130102.       if( pE->op!=TK_ASTERISK

  130103.        && (pE->op!=TK_DOT || pRight->op!=TK_ASTERISK)

  130104.       ){

  130105.         /* This particular expression does not need to be expanded.

  130106.         */

  130107.         pNew = sqlite3ExprListAppend(pParse, pNew, a[k].pExpr);

  130108.         if( pNew ){

  130109.           pNew->a[pNew->nExpr-1].zName = a[k].zName;

  130110.           pNew->a[pNew->nExpr-1].zSpan = a[k].zSpan;

  130111.           a[k].zName = 0;

  130112.           a[k].zSpan = 0;

  130113.         }

  130114.         a[k].pExpr = 0;

  130115.       }else{

  130116.         /* This expression is a "*" or a "TABLE.*" and needs to be

  130117.         ** expanded. */

  130118.         int tableSeen = 0;      /* Set to 1 when TABLE matches */

  130119.         char *zTName = 0;       /* text of name of TABLE */

  130120.         if( pE->op==TK_DOT ){

  130121.           assert( pE->pLeft!=0 );

  130122.           assert( !ExprHasProperty(pE->pLeft, EP_IntValue) );

  130123.           zTName = pE->pLeft->u.zToken;

  130124.         }

  130125.         for(i=0, pFrom=pTabList->a; i<pTabList->nSrc; i++, pFrom++){

  130126.           Table *pTab = pFrom->pTab;

  130127.           Select *pSub = pFrom->pSelect;

  130128.           char *zTabName = pFrom->zAlias;

  130129.           const char *zSchemaName = 0;

  130130.           int iDb;

  130131.           if( zTabName==0 ){

  130132.             zTabName = pTab->zName;

  130133.           }

  130134.           if( db->mallocFailed ) break;

  130135.           if( pSub==0 || (pSub->selFlags & SF_NestedFrom)==0 ){

  130136.             pSub = 0;

  130137.             if( zTName && sqlite3StrICmp(zTName, zTabName)!=0 ){

  130138.               continue;

  130139.             }

  130140.             iDb = sqlite3SchemaToIndex(db, pTab->pSchema);

  130141.             zSchemaName = iDb>=0 ? db->aDb[iDb].zDbSName : "*";

  130142.           }

  130143.           for(j=0; j<pTab->nCol; j++){

  130144.             char *zName = pTab->aCol[j].zName;

  130145.             char *zColname;  /* The computed column name */

  130146.             char *zToFree;   /* Malloced string that needs to be freed */

  130147.             Token sColname;  /* Computed column name as a token */

  130148. 

  130149.             assert( zName );

  130150.             if( zTName && pSub

  130151.              && sqlite3MatchSpanName(pSub->pEList->a[j].zSpan, 0, zTName, 0)==0

  130152.             ){

  130153.               continue;

  130154.             }

  130155. 

  130156.             /* If a column is marked as 'hidden', omit it from the expanded

  130157.             ** result-set list unless the SELECT has the SF_IncludeHidden

  130158.             ** bit set.

  130159.             */

  130160.             if( (p->selFlags & SF_IncludeHidden)==0

  130161.              && IsHiddenColumn(&pTab->aCol[j]) 

  130162.             ){

  130163.               continue;

  130164.             }

  130165.             tableSeen = 1;

  130166. 

  130167.             if( i>0 && zTName==0 ){

  130168.               if( (pFrom->fg.jointype & JT_NATURAL)!=0

  130169.                 && tableAndColumnIndex(pTabList, i, zName, 0, 0)

  130170.               ){

  130171.                 /* In a NATURAL join, omit the join columns from the 

  130172.                 ** table to the right of the join */

  130173.                 continue;

  130174.               }

  130175.               if( sqlite3IdListIndex(pFrom->pUsing, zName)>=0 ){

  130176.                 /* In a join with a USING clause, omit columns in the

  130177.                 ** using clause from the table on the right. */

  130178.                 continue;

  130179.               }

  130180.             }

  130181.             pRight = sqlite3Expr(db, TK_ID, zName);

  130182.             zColname = zName;

  130183.             zToFree = 0;

  130184.             if( longNames || pTabList->nSrc>1 ){

  130185.               Expr *pLeft;

  130186.               pLeft = sqlite3Expr(db, TK_ID, zTabName);

  130187.               pExpr = sqlite3PExpr(pParse, TK_DOT, pLeft, pRight);

  130188.               if( zSchemaName ){

  130189.                 pLeft = sqlite3Expr(db, TK_ID, zSchemaName);

  130190.                 pExpr = sqlite3PExpr(pParse, TK_DOT, pLeft, pExpr);

  130191.               }

  130192.               if( longNames ){

  130193.                 zColname = sqlite3MPrintf(db, "%s.%s", zTabName, zName);

  130194.                 zToFree = zColname;

  130195.               }

  130196.             }else{

  130197.               pExpr = pRight;

  130198.             }

  130199.             pNew = sqlite3ExprListAppend(pParse, pNew, pExpr);

  130200.             sqlite3TokenInit(&sColname, zColname);

  130201.             sqlite3ExprListSetName(pParse, pNew, &sColname, 0);

  130202.             if( pNew && (p->selFlags & SF_NestedFrom)!=0 ){

  130203.               struct ExprList_item *pX = &pNew->a[pNew->nExpr-1];

  130204.               if( pSub ){

  130205.                 pX->zSpan = sqlite3DbStrDup(db, pSub->pEList->a[j].zSpan);

  130206.                 testcase( pX->zSpan==0 );

  130207.               }else{

  130208.                 pX->zSpan = sqlite3MPrintf(db, "%s.%s.%s",

  130209.                                            zSchemaName, zTabName, zColname);

  130210.                 testcase( pX->zSpan==0 );

  130211.               }

  130212.               pX->bSpanIsTab = 1;

  130213.             }

  130214.             sqlite3DbFree(db, zToFree);

  130215.           }

  130216.         }

  130217.         if( !tableSeen ){

  130218.           if( zTName ){

  130219.             sqlite3ErrorMsg(pParse, "no such table: %s", zTName);

  130220.           }else{

  130221.             sqlite3ErrorMsg(pParse, "no tables specified");

  130222.           }

  130223.         }

  130224.       }

  130225.     }

  130226.     sqlite3ExprListDelete(db, pEList);

  130227.     p->pEList = pNew;

  130228.   }

  130229.   if( p->pEList ){

  130230.     if( p->pEList->nExpr>db->aLimit[SQLITE_LIMIT_COLUMN] ){

  130231.       sqlite3ErrorMsg(pParse, "too many columns in result set");

  130232.       return WRC_Abort;

  130233.     }

  130234.     if( (elistFlags & (EP_HasFunc|EP_Subquery))!=0 ){

  130235.       p->selFlags |= SF_ComplexResult;

  130236.     }

  130237.   }

  130238.   return WRC_Continue;

  130239. }

  130240. 

  130241. /*

  130242. ** No-op routine for the parse-tree walker.

  130243. **

  130244. ** When this routine is the Walker.xExprCallback then expression trees

  130245. ** are walked without any actions being taken at each node.  Presumably,

  130246. ** when this routine is used for Walker.xExprCallback then 

  130247. ** Walker.xSelectCallback is set to do something useful for every 

  130248. ** subquery in the parser tree.

  130249. */

  130250. SQLITE_PRIVATE int sqlite3ExprWalkNoop(Walker *NotUsed, Expr *NotUsed2){

  130251.   UNUSED_PARAMETER2(NotUsed, NotUsed2);

  130252.   return WRC_Continue;

  130253. }

  130254. 

  130255. /*

  130256. ** No-op routine for the parse-tree walker for SELECT statements.

  130257. ** subquery in the parser tree.

  130258. */

  130259. SQLITE_PRIVATE int sqlite3SelectWalkNoop(Walker *NotUsed, Select *NotUsed2){

  130260.   UNUSED_PARAMETER2(NotUsed, NotUsed2);

  130261.   return WRC_Continue;

  130262. }

  130263. 

  130264. #if SQLITE_DEBUG

  130265. /*

  130266. ** Always assert.  This xSelectCallback2 implementation proves that the

  130267. ** xSelectCallback2 is never invoked.

  130268. */

  130269. SQLITE_PRIVATE void sqlite3SelectWalkAssert2(Walker *NotUsed, Select *NotUsed2){

  130270.   UNUSED_PARAMETER2(NotUsed, NotUsed2);

  130271.   assert( 0 );

  130272. }

  130273. #endif

  130274. /*

  130275. ** This routine "expands" a SELECT statement and all of its subqueries.

  130276. ** For additional information on what it means to "expand" a SELECT

  130277. ** statement, see the comment on the selectExpand worker callback above.

  130278. **

  130279. ** Expanding a SELECT statement is the first step in processing a

  130280. ** SELECT statement.  The SELECT statement must be expanded before

  130281. ** name resolution is performed.

  130282. **

  130283. ** If anything goes wrong, an error message is written into pParse.

  130284. ** The calling function can detect the problem by looking at pParse->nErr

  130285. ** and/or pParse->db->mallocFailed.

  130286. */

  130287. static void sqlite3SelectExpand(Parse *pParse, Select *pSelect){

  130288.   Walker w;

  130289.   w.xExprCallback = sqlite3ExprWalkNoop;

  130290.   w.pParse = pParse;

  130291.   if( OK_IF_ALWAYS_TRUE(pParse->hasCompound) ){

  130292.     w.xSelectCallback = convertCompoundSelectToSubquery;

  130293.     w.xSelectCallback2 = 0;

  130294.     sqlite3WalkSelect(&w, pSelect);

  130295.   }

  130296.   w.xSelectCallback = selectExpander;

  130297.   w.xSelectCallback2 = selectPopWith;

  130298.   w.eCode = 0;

  130299.   sqlite3WalkSelect(&w, pSelect);

  130300. }

  130301. 

  130302. 

  130303. #ifndef SQLITE_OMIT_SUBQUERY

  130304. /*

  130305. ** This is a Walker.xSelectCallback callback for the sqlite3SelectTypeInfo()

  130306. ** interface.

  130307. **

  130308. ** For each FROM-clause subquery, add Column.zType and Column.zColl

  130309. ** information to the Table structure that represents the result set

  130310. ** of that subquery.

  130311. **

  130312. ** The Table structure that represents the result set was constructed

  130313. ** by selectExpander() but the type and collation information was omitted

  130314. ** at that point because identifiers had not yet been resolved.  This

  130315. ** routine is called after identifier resolution.

  130316. */

  130317. static void selectAddSubqueryTypeInfo(Walker *pWalker, Select *p){

  130318.   Parse *pParse;

  130319.   int i;

  130320.   SrcList *pTabList;

  130321.   struct SrcList_item *pFrom;

  130322. 

  130323.   assert( p->selFlags & SF_Resolved );

  130324.   if( p->selFlags & SF_HasTypeInfo ) return;

  130325.   p->selFlags |= SF_HasTypeInfo;

  130326.   pParse = pWalker->pParse;

  130327.   pTabList = p->pSrc;

  130328.   for(i=0, pFrom=pTabList->a; i<pTabList->nSrc; i++, pFrom++){

  130329.     Table *pTab = pFrom->pTab;

  130330.     assert( pTab!=0 );

  130331.     if( (pTab->tabFlags & TF_Ephemeral)!=0 ){

  130332.       /* A sub-query in the FROM clause of a SELECT */

  130333.       Select *pSel = pFrom->pSelect;

  130334.       if( pSel ){

  130335.         while( pSel->pPrior ) pSel = pSel->pPrior;

  130336.         sqlite3SelectAddColumnTypeAndCollation(pParse, pTab, pSel);

  130337.       }

  130338.     }

  130339.   }

  130340. }

  130341. #endif

  130342. 

  130343. 

  130344. /*

  130345. ** This routine adds datatype and collating sequence information to

  130346. ** the Table structures of all FROM-clause subqueries in a

  130347. ** SELECT statement.

  130348. **

  130349. ** Use this routine after name resolution.

  130350. */

  130351. static void sqlite3SelectAddTypeInfo(Parse *pParse, Select *pSelect){

  130352. #ifndef SQLITE_OMIT_SUBQUERY

  130353.   Walker w;

  130354.   w.xSelectCallback = sqlite3SelectWalkNoop;

  130355.   w.xSelectCallback2 = selectAddSubqueryTypeInfo;

  130356.   w.xExprCallback = sqlite3ExprWalkNoop;

  130357.   w.pParse = pParse;

  130358.   sqlite3WalkSelect(&w, pSelect);

  130359. #endif

  130360. }

  130361. 

  130362. 

  130363. /*

  130364. ** This routine sets up a SELECT statement for processing.  The

  130365. ** following is accomplished:

  130366. **

  130367. **     *  VDBE Cursor numbers are assigned to all FROM-clause terms.

  130368. **     *  Ephemeral Table objects are created for all FROM-clause subqueries.

  130369. **     *  ON and USING clauses are shifted into WHERE statements

  130370. **     *  Wildcards "*" and "TABLE.*" in result sets are expanded.

  130371. **     *  Identifiers in expression are matched to tables.

  130372. **

  130373. ** This routine acts recursively on all subqueries within the SELECT.

  130374. */

  130375. SQLITE_PRIVATE void sqlite3SelectPrep(

  130376.   Parse *pParse,         /* The parser context */

  130377.   Select *p,             /* The SELECT statement being coded. */

  130378.   NameContext *pOuterNC  /* Name context for container */

  130379. ){

  130380.   assert( p!=0 || pParse->db->mallocFailed );

  130381.   if( pParse->db->mallocFailed ) return;

  130382.   if( p->selFlags & SF_HasTypeInfo ) return;

  130383.   sqlite3SelectExpand(pParse, p);

  130384.   if( pParse->nErr || pParse->db->mallocFailed ) return;

  130385.   sqlite3ResolveSelectNames(pParse, p, pOuterNC);

  130386.   if( pParse->nErr || pParse->db->mallocFailed ) return;

  130387.   sqlite3SelectAddTypeInfo(pParse, p);

  130388. }

  130389. 

  130390. /*

  130391. ** Reset the aggregate accumulator.

  130392. **

  130393. ** The aggregate accumulator is a set of memory cells that hold

  130394. ** intermediate results while calculating an aggregate.  This

  130395. ** routine generates code that stores NULLs in all of those memory

  130396. ** cells.

  130397. */

  130398. static void resetAccumulator(Parse *pParse, AggInfo *pAggInfo){

  130399.   Vdbe *v = pParse->pVdbe;

  130400.   int i;

  130401.   struct AggInfo_func *pFunc;

  130402.   int nReg = pAggInfo->nFunc + pAggInfo->nColumn;

  130403.   if( nReg==0 ) return;

  130404. #ifdef SQLITE_DEBUG

  130405.   /* Verify that all AggInfo registers are within the range specified by

  130406.   ** AggInfo.mnReg..AggInfo.mxReg */

  130407.   assert( nReg==pAggInfo->mxReg-pAggInfo->mnReg+1 );

  130408.   for(i=0; i<pAggInfo->nColumn; i++){

  130409.     assert( pAggInfo->aCol[i].iMem>=pAggInfo->mnReg

  130410.          && pAggInfo->aCol[i].iMem<=pAggInfo->mxReg );

  130411.   }

  130412.   for(i=0; i<pAggInfo->nFunc; i++){

  130413.     assert( pAggInfo->aFunc[i].iMem>=pAggInfo->mnReg

  130414.          && pAggInfo->aFunc[i].iMem<=pAggInfo->mxReg );

  130415.   }

  130416. #endif

  130417.   sqlite3VdbeAddOp3(v, OP_Null, 0, pAggInfo->mnReg, pAggInfo->mxReg);

  130418.   for(pFunc=pAggInfo->aFunc, i=0; i<pAggInfo->nFunc; i++, pFunc++){

  130419.     if( pFunc->iDistinct>=0 ){

  130420.       Expr *pE = pFunc->pExpr;

  130421.       assert( !ExprHasProperty(pE, EP_xIsSelect) );

  130422.       if( pE->x.pList==0 || pE->x.pList->nExpr!=1 ){

  130423.         sqlite3ErrorMsg(pParse, "DISTINCT aggregates must have exactly one "

  130424.            "argument");

  130425.         pFunc->iDistinct = -1;

  130426.       }else{

  130427.         KeyInfo *pKeyInfo = sqlite3KeyInfoFromExprList(pParse, pE->x.pList,0,0);

  130428.         sqlite3VdbeAddOp4(v, OP_OpenEphemeral, pFunc->iDistinct, 0, 0,

  130429.                           (char*)pKeyInfo, P4_KEYINFO);

  130430.       }

  130431.     }

  130432.   }

  130433. }

  130434. 

  130435. /*

  130436. ** Invoke the OP_AggFinalize opcode for every aggregate function

  130437. ** in the AggInfo structure.

  130438. */

  130439. static void finalizeAggFunctions(Parse *pParse, AggInfo *pAggInfo){

  130440.   Vdbe *v = pParse->pVdbe;

  130441.   int i;

  130442.   struct AggInfo_func *pF;

  130443.   for(i=0, pF=pAggInfo->aFunc; i<pAggInfo->nFunc; i++, pF++){

  130444.     ExprList *pList = pF->pExpr->x.pList;

  130445.     assert( !ExprHasProperty(pF->pExpr, EP_xIsSelect) );

  130446.     sqlite3VdbeAddOp2(v, OP_AggFinal, pF->iMem, pList ? pList->nExpr : 0);

  130447.     sqlite3VdbeAppendP4(v, pF->pFunc, P4_FUNCDEF);

  130448.   }

  130449. }

  130450. 

  130451. 

  130452. /*

  130453. ** Update the accumulator memory cells for an aggregate based on

  130454. ** the current cursor position.

  130455. **

  130456. ** If regAcc is non-zero and there are no min() or max() aggregates

  130457. ** in pAggInfo, then only populate the pAggInfo->nAccumulator accumulator

  130458. ** registers if register regAcc contains 0. The caller will take care

  130459. ** of setting and clearing regAcc.

  130460. */

  130461. static void updateAccumulator(Parse *pParse, int regAcc, AggInfo *pAggInfo){

  130462.   Vdbe *v = pParse->pVdbe;

  130463.   int i;

  130464.   int regHit = 0;

  130465.   int addrHitTest = 0;

  130466.   struct AggInfo_func *pF;

  130467.   struct AggInfo_col *pC;

  130468. 

  130469.   pAggInfo->directMode = 1;

  130470.   for(i=0, pF=pAggInfo->aFunc; i<pAggInfo->nFunc; i++, pF++){

  130471.     int nArg;

  130472.     int addrNext = 0;

  130473.     int regAgg;

  130474.     ExprList *pList = pF->pExpr->x.pList;

  130475.     assert( !ExprHasProperty(pF->pExpr, EP_xIsSelect) );

  130476.     if( pList ){

  130477.       nArg = pList->nExpr;

  130478.       regAgg = sqlite3GetTempRange(pParse, nArg);

  130479.       sqlite3ExprCodeExprList(pParse, pList, regAgg, 0, SQLITE_ECEL_DUP);

  130480.     }else{

  130481.       nArg = 0;

  130482.       regAgg = 0;

  130483.     }

  130484.     if( pF->iDistinct>=0 ){

  130485.       addrNext = sqlite3VdbeMakeLabel(pParse);

  130486.       testcase( nArg==0 );  /* Error condition */

  130487.       testcase( nArg>1 );   /* Also an error */

  130488.       codeDistinct(pParse, pF->iDistinct, addrNext, 1, regAgg);

  130489.     }

  130490.     if( pF->pFunc->funcFlags & SQLITE_FUNC_NEEDCOLL ){

  130491.       CollSeq *pColl = 0;

  130492.       struct ExprList_item *pItem;

  130493.       int j;

  130494.       assert( pList!=0 );  /* pList!=0 if pF->pFunc has NEEDCOLL */

  130495.       for(j=0, pItem=pList->a; !pColl && j<nArg; j++, pItem++){

  130496.         pColl = sqlite3ExprCollSeq(pParse, pItem->pExpr);

  130497.       }

  130498.       if( !pColl ){

  130499.         pColl = pParse->db->pDfltColl;

  130500.       }

  130501.       if( regHit==0 && pAggInfo->nAccumulator ) regHit = ++pParse->nMem;

  130502.       sqlite3VdbeAddOp4(v, OP_CollSeq, regHit, 0, 0, (char *)pColl, P4_COLLSEQ);

  130503.     }

  130504.     sqlite3VdbeAddOp3(v, OP_AggStep, 0, regAgg, pF->iMem);

  130505.     sqlite3VdbeAppendP4(v, pF->pFunc, P4_FUNCDEF);

  130506.     sqlite3VdbeChangeP5(v, (u8)nArg);

  130507.     sqlite3ReleaseTempRange(pParse, regAgg, nArg);

  130508.     if( addrNext ){

  130509.       sqlite3VdbeResolveLabel(v, addrNext);

  130510.     }

  130511.   }

  130512.   if( regHit==0 && pAggInfo->nAccumulator ){

  130513.     regHit = regAcc;

  130514.   }

  130515.   if( regHit ){

  130516.     addrHitTest = sqlite3VdbeAddOp1(v, OP_If, regHit); VdbeCoverage(v);

  130517.   }

  130518.   for(i=0, pC=pAggInfo->aCol; i<pAggInfo->nAccumulator; i++, pC++){

  130519.     sqlite3ExprCode(pParse, pC->pExpr, pC->iMem);

  130520.   }

  130521.   pAggInfo->directMode = 0;

  130522.   if( addrHitTest ){

  130523.     sqlite3VdbeJumpHere(v, addrHitTest);

  130524.   }

  130525. }

  130526. 

  130527. /*

  130528. ** Add a single OP_Explain instruction to the VDBE to explain a simple

  130529. ** count(*) query ("SELECT count(*) FROM pTab").

  130530. */

  130531. #ifndef SQLITE_OMIT_EXPLAIN

  130532. static void explainSimpleCount(

  130533.   Parse *pParse,                  /* Parse context */

  130534.   Table *pTab,                    /* Table being queried */

  130535.   Index *pIdx                     /* Index used to optimize scan, or NULL */

  130536. ){

  130537.   if( pParse->explain==2 ){

  130538.     int bCover = (pIdx!=0 && (HasRowid(pTab) || !IsPrimaryKeyIndex(pIdx)));

  130539.     sqlite3VdbeExplain(pParse, 0, "SCAN TABLE %s%s%s",

  130540.         pTab->zName,

  130541.         bCover ? " USING COVERING INDEX " : "",

  130542.         bCover ? pIdx->zName : ""

  130543.     );

  130544.   }

  130545. }

  130546. #else

  130547. # define explainSimpleCount(a,b,c)

  130548. #endif

  130549. 

  130550. /*

  130551. ** sqlite3WalkExpr() callback used by havingToWhere().

  130552. **

  130553. ** If the node passed to the callback is a TK_AND node, return 

  130554. ** WRC_Continue to tell sqlite3WalkExpr() to iterate through child nodes.

  130555. **

  130556. ** Otherwise, return WRC_Prune. In this case, also check if the 

  130557. ** sub-expression matches the criteria for being moved to the WHERE

  130558. ** clause. If so, add it to the WHERE clause and replace the sub-expression

  130559. ** within the HAVING expression with a constant "1".

  130560. */

  130561. static int havingToWhereExprCb(Walker *pWalker, Expr *pExpr){

  130562.   if( pExpr->op!=TK_AND ){

  130563.     Select *pS = pWalker->u.pSelect;

  130564.     if( sqlite3ExprIsConstantOrGroupBy(pWalker->pParse, pExpr, pS->pGroupBy) ){

  130565.       sqlite3 *db = pWalker->pParse->db;

  130566.       Expr *pNew = sqlite3ExprAlloc(db, TK_INTEGER, &sqlite3IntTokens[1], 0);

  130567.       if( pNew ){

  130568.         Expr *pWhere = pS->pWhere;

  130569.         SWAP(Expr, *pNew, *pExpr);

  130570.         pNew = sqlite3ExprAnd(pWalker->pParse, pWhere, pNew);

  130571.         pS->pWhere = pNew;

  130572.         pWalker->eCode = 1;

  130573.       }

  130574.     }

  130575.     return WRC_Prune;

  130576.   }

  130577.   return WRC_Continue;

  130578. }

  130579. 

  130580. /*

  130581. ** Transfer eligible terms from the HAVING clause of a query, which is

  130582. ** processed after grouping, to the WHERE clause, which is processed before

  130583. ** grouping. For example, the query:

  130584. **

  130585. **   SELECT * FROM <tables> WHERE a=? GROUP BY b HAVING b=? AND c=?

  130586. **

  130587. ** can be rewritten as:

  130588. **

  130589. **   SELECT * FROM <tables> WHERE a=? AND b=? GROUP BY b HAVING c=?

  130590. **

  130591. ** A term of the HAVING expression is eligible for transfer if it consists

  130592. ** entirely of constants and expressions that are also GROUP BY terms that

  130593. ** use the "BINARY" collation sequence.

  130594. */

  130595. static void havingToWhere(Parse *pParse, Select *p){

  130596.   Walker sWalker;

  130597.   memset(&sWalker, 0, sizeof(sWalker));

  130598.   sWalker.pParse = pParse;

  130599.   sWalker.xExprCallback = havingToWhereExprCb;

  130600.   sWalker.u.pSelect = p;

  130601.   sqlite3WalkExpr(&sWalker, p->pHaving);

  130602. #if SELECTTRACE_ENABLED

  130603.   if( sWalker.eCode && (sqlite3SelectTrace & 0x100)!=0 ){

  130604.     SELECTTRACE(0x100,pParse,p,("Move HAVING terms into WHERE:\n"));

  130605.     sqlite3TreeViewSelect(0, p, 0);

  130606.   }

  130607. #endif

  130608. }

  130609. 

  130610. /*

  130611. ** Check to see if the pThis entry of pTabList is a self-join of a prior view.

  130612. ** If it is, then return the SrcList_item for the prior view.  If it is not,

  130613. ** then return 0.

  130614. */

  130615. static struct SrcList_item *isSelfJoinView(

  130616.   SrcList *pTabList,           /* Search for self-joins in this FROM clause */

  130617.   struct SrcList_item *pThis   /* Search for prior reference to this subquery */

  130618. ){

  130619.   struct SrcList_item *pItem;

  130620.   for(pItem = pTabList->a; pItem<pThis; pItem++){

  130621.     Select *pS1;

  130622.     if( pItem->pSelect==0 ) continue;

  130623.     if( pItem->fg.viaCoroutine ) continue;

  130624.     if( pItem->zName==0 ) continue;

  130625.     assert( pItem->pTab!=0 );

  130626.     assert( pThis->pTab!=0 );

  130627.     if( pItem->pTab->pSchema!=pThis->pTab->pSchema ) continue;

  130628.     if( sqlite3_stricmp(pItem->zName, pThis->zName)!=0 ) continue;

  130629.     pS1 = pItem->pSelect;

  130630.     if( pItem->pTab->pSchema==0 && pThis->pSelect->selId!=pS1->selId ){

  130631.       /* The query flattener left two different CTE tables with identical

  130632.       ** names in the same FROM clause. */

  130633.       continue;

  130634.     }

  130635.     if( sqlite3ExprCompare(0, pThis->pSelect->pWhere, pS1->pWhere, -1)

  130636.      || sqlite3ExprCompare(0, pThis->pSelect->pHaving, pS1->pHaving, -1) 

  130637.     ){

  130638.       /* The view was modified by some other optimization such as

  130639.       ** pushDownWhereTerms() */

  130640.       continue;

  130641.     }

  130642.     return pItem;

  130643.   }

  130644.   return 0;

  130645. }

  130646. 

  130647. #ifdef SQLITE_COUNTOFVIEW_OPTIMIZATION

  130648. /*

  130649. ** Attempt to transform a query of the form

  130650. **

  130651. **    SELECT count(*) FROM (SELECT x FROM t1 UNION ALL SELECT y FROM t2)

  130652. **

  130653. ** Into this:

  130654. **

  130655. **    SELECT (SELECT count(*) FROM t1)+(SELECT count(*) FROM t2)

  130656. **

  130657. ** The transformation only works if all of the following are true:

  130658. **

  130659. **   *  The subquery is a UNION ALL of two or more terms

  130660. **   *  The subquery does not have a LIMIT clause

  130661. **   *  There is no WHERE or GROUP BY or HAVING clauses on the subqueries

  130662. **   *  The outer query is a simple count(*) with no WHERE clause or other

  130663. **      extraneous syntax.

  130664. **

  130665. ** Return TRUE if the optimization is undertaken.

  130666. */

  130667. static int countOfViewOptimization(Parse *pParse, Select *p){

  130668.   Select *pSub, *pPrior;

  130669.   Expr *pExpr;

  130670.   Expr *pCount;

  130671.   sqlite3 *db;

  130672.   if( (p->selFlags & SF_Aggregate)==0 ) return 0;   /* This is an aggregate */

  130673.   if( p->pEList->nExpr!=1 ) return 0;               /* Single result column */

  130674.   if( p->pWhere ) return 0;

  130675.   if( p->pGroupBy ) return 0;

  130676.   pExpr = p->pEList->a[0].pExpr;

  130677.   if( pExpr->op!=TK_AGG_FUNCTION ) return 0;        /* Result is an aggregate */

  130678.   if( sqlite3_stricmp(pExpr->u.zToken,"count") ) return 0;  /* Is count() */

  130679.   if( pExpr->x.pList!=0 ) return 0;                 /* Must be count(*) */

  130680.   if( p->pSrc->nSrc!=1 ) return 0;                  /* One table in FROM  */

  130681.   pSub = p->pSrc->a[0].pSelect;

  130682.   if( pSub==0 ) return 0;                           /* The FROM is a subquery */

  130683.   if( pSub->pPrior==0 ) return 0;                   /* Must be a compound ry */

  130684.   do{

  130685.     if( pSub->op!=TK_ALL && pSub->pPrior ) return 0;  /* Must be UNION ALL */

  130686.     if( pSub->pWhere ) return 0;                      /* No WHERE clause */

  130687.     if( pSub->pLimit ) return 0;                      /* No LIMIT clause */

  130688.     if( pSub->selFlags & SF_Aggregate ) return 0;     /* Not an aggregate */

  130689.     pSub = pSub->pPrior;                              /* Repeat over compound */

  130690.   }while( pSub );

  130691. 

  130692.   /* If we reach this point then it is OK to perform the transformation */

  130693. 

  130694.   db = pParse->db;

  130695.   pCount = pExpr;

  130696.   pExpr = 0;

  130697.   pSub = p->pSrc->a[0].pSelect;

  130698.   p->pSrc->a[0].pSelect = 0;

  130699.   sqlite3SrcListDelete(db, p->pSrc);

  130700.   p->pSrc = sqlite3DbMallocZero(pParse->db, sizeof(*p->pSrc));

  130701.   while( pSub ){

  130702.     Expr *pTerm;

  130703.     pPrior = pSub->pPrior;

  130704.     pSub->pPrior = 0;

  130705.     pSub->pNext = 0;

  130706.     pSub->selFlags |= SF_Aggregate;

  130707.     pSub->selFlags &= ~SF_Compound;

  130708.     pSub->nSelectRow = 0;

  130709.     sqlite3ExprListDelete(db, pSub->pEList);

  130710.     pTerm = pPrior ? sqlite3ExprDup(db, pCount, 0) : pCount;

  130711.     pSub->pEList = sqlite3ExprListAppend(pParse, 0, pTerm);

  130712.     pTerm = sqlite3PExpr(pParse, TK_SELECT, 0, 0);

  130713.     sqlite3PExprAddSelect(pParse, pTerm, pSub);

  130714.     if( pExpr==0 ){

  130715.       pExpr = pTerm;

  130716.     }else{

  130717.       pExpr = sqlite3PExpr(pParse, TK_PLUS, pTerm, pExpr);

  130718.     }

  130719.     pSub = pPrior;

  130720.   }

  130721.   p->pEList->a[0].pExpr = pExpr;

  130722.   p->selFlags &= ~SF_Aggregate;

  130723. 

  130724. #if SELECTTRACE_ENABLED

  130725.   if( sqlite3SelectTrace & 0x400 ){

  130726.     SELECTTRACE(0x400,pParse,p,("After count-of-view optimization:\n"));

  130727.     sqlite3TreeViewSelect(0, p, 0);

  130728.   }

  130729. #endif

  130730.   return 1;

  130731. }

  130732. #endif /* SQLITE_COUNTOFVIEW_OPTIMIZATION */

  130733. 

  130734. /*

  130735. ** Generate code for the SELECT statement given in the p argument.  

  130736. **

  130737. ** The results are returned according to the SelectDest structure.

  130738. ** See comments in sqliteInt.h for further information.

  130739. **

  130740. ** This routine returns the number of errors.  If any errors are

  130741. ** encountered, then an appropriate error message is left in

  130742. ** pParse->zErrMsg.

  130743. **

  130744. ** This routine does NOT free the Select structure passed in.  The

  130745. ** calling function needs to do that.

  130746. */

  130747. SQLITE_PRIVATE int sqlite3Select(

  130748.   Parse *pParse,         /* The parser context */

  130749.   Select *p,             /* The SELECT statement being coded. */

  130750.   SelectDest *pDest      /* What to do with the query results */

  130751. ){

  130752.   int i, j;              /* Loop counters */

  130753.   WhereInfo *pWInfo;     /* Return from sqlite3WhereBegin() */

  130754.   Vdbe *v;               /* The virtual machine under construction */

  130755.   int isAgg;             /* True for select lists like "count(*)" */

  130756.   ExprList *pEList = 0;  /* List of columns to extract. */

  130757.   SrcList *pTabList;     /* List of tables to select from */

  130758.   Expr *pWhere;          /* The WHERE clause.  May be NULL */

  130759.   ExprList *pGroupBy;    /* The GROUP BY clause.  May be NULL */

  130760.   Expr *pHaving;         /* The HAVING clause.  May be NULL */

  130761.   int rc = 1;            /* Value to return from this function */

  130762.   DistinctCtx sDistinct; /* Info on how to code the DISTINCT keyword */

  130763.   SortCtx sSort;         /* Info on how to code the ORDER BY clause */

  130764.   AggInfo sAggInfo;      /* Information used by aggregate queries */

  130765.   int iEnd;              /* Address of the end of the query */

  130766.   sqlite3 *db;           /* The database connection */

  130767.   ExprList *pMinMaxOrderBy = 0;  /* Added ORDER BY for min/max queries */

  130768.   u8 minMaxFlag;                 /* Flag for min/max queries */

  130769. 

  130770.   db = pParse->db;

  130771.   v = sqlite3GetVdbe(pParse);

  130772.   if( p==0 || db->mallocFailed || pParse->nErr ){

  130773.     return 1;

  130774.   }

  130775.   if( sqlite3AuthCheck(pParse, SQLITE_SELECT, 0, 0, 0) ) return 1;

  130776.   memset(&sAggInfo, 0, sizeof(sAggInfo));

  130777. #if SELECTTRACE_ENABLED

  130778.   SELECTTRACE(1,pParse,p, ("begin processing:\n", pParse->addrExplain));

  130779.   if( sqlite3SelectTrace & 0x100 ){

  130780.     sqlite3TreeViewSelect(0, p, 0);

  130781.   }

  130782. #endif

  130783. 

  130784.   assert( p->pOrderBy==0 || pDest->eDest!=SRT_DistFifo );

  130785.   assert( p->pOrderBy==0 || pDest->eDest!=SRT_Fifo );

  130786.   assert( p->pOrderBy==0 || pDest->eDest!=SRT_DistQueue );

  130787.   assert( p->pOrderBy==0 || pDest->eDest!=SRT_Queue );

  130788.   if( IgnorableOrderby(pDest) ){

  130789.     assert(pDest->eDest==SRT_Exists || pDest->eDest==SRT_Union || 

  130790.            pDest->eDest==SRT_Except || pDest->eDest==SRT_Discard ||

  130791.            pDest->eDest==SRT_Queue  || pDest->eDest==SRT_DistFifo ||

  130792.            pDest->eDest==SRT_DistQueue || pDest->eDest==SRT_Fifo);

  130793.     /* If ORDER BY makes no difference in the output then neither does

  130794.     ** DISTINCT so it can be removed too. */

  130795.     sqlite3ExprListDelete(db, p->pOrderBy);

  130796.     p->pOrderBy = 0;

  130797.     p->selFlags &= ~SF_Distinct;

  130798.   }

  130799.   sqlite3SelectPrep(pParse, p, 0);

  130800.   if( pParse->nErr || db->mallocFailed ){

  130801.     goto select_end;

  130802.   }

  130803.   assert( p->pEList!=0 );

  130804. #if SELECTTRACE_ENABLED

  130805.   if( sqlite3SelectTrace & 0x104 ){

  130806.     SELECTTRACE(0x104,pParse,p, ("after name resolution:\n"));

  130807.     sqlite3TreeViewSelect(0, p, 0);

  130808.   }

  130809. #endif

  130810. 

  130811.   if( pDest->eDest==SRT_Output ){

  130812.     generateColumnNames(pParse, p);

  130813.   }

  130814. 

  130815. #ifndef SQLITE_OMIT_WINDOWFUNC

  130816.   if( sqlite3WindowRewrite(pParse, p) ){

  130817.     goto select_end;

  130818.   }

  130819. #if SELECTTRACE_ENABLED

  130820.   if( sqlite3SelectTrace & 0x108 ){

  130821.     SELECTTRACE(0x104,pParse,p, ("after window rewrite:\n"));

  130822.     sqlite3TreeViewSelect(0, p, 0);

  130823.   }

  130824. #endif

  130825. #endif /* SQLITE_OMIT_WINDOWFUNC */

  130826.   pTabList = p->pSrc;

  130827.   isAgg = (p->selFlags & SF_Aggregate)!=0;

  130828.   memset(&sSort, 0, sizeof(sSort));

  130829.   sSort.pOrderBy = p->pOrderBy;

  130830. 

  130831.   /* Try to various optimizations (flattening subqueries, and strength

  130832.   ** reduction of join operators) in the FROM clause up into the main query

  130833.   */

  130834. #if !defined(SQLITE_OMIT_SUBQUERY) || !defined(SQLITE_OMIT_VIEW)

  130835.   for(i=0; !p->pPrior && i<pTabList->nSrc; i++){

  130836.     struct SrcList_item *pItem = &pTabList->a[i];

  130837.     Select *pSub = pItem->pSelect;

  130838.     Table *pTab = pItem->pTab;

  130839. 

  130840.     /* Convert LEFT JOIN into JOIN if there are terms of the right table

  130841.     ** of the LEFT JOIN used in the WHERE clause.

  130842.     */

  130843.     if( (pItem->fg.jointype & JT_LEFT)!=0

  130844.      && sqlite3ExprImpliesNonNullRow(p->pWhere, pItem->iCursor)

  130845.      && OptimizationEnabled(db, SQLITE_SimplifyJoin)

  130846.     ){

  130847.       SELECTTRACE(0x100,pParse,p,

  130848.                 ("LEFT-JOIN simplifies to JOIN on term %d\n",i));

  130849.       pItem->fg.jointype &= ~(JT_LEFT|JT_OUTER);

  130850.       unsetJoinExpr(p->pWhere, pItem->iCursor);

  130851.     }

  130852. 

  130853.     /* No futher action if this term of the FROM clause is no a subquery */

  130854.     if( pSub==0 ) continue;

  130855. 

  130856.     /* Catch mismatch in the declared columns of a view and the number of

  130857.     ** columns in the SELECT on the RHS */

  130858.     if( pTab->nCol!=pSub->pEList->nExpr ){

  130859.       sqlite3ErrorMsg(pParse, "expected %d columns for '%s' but got %d",

  130860.                       pTab->nCol, pTab->zName, pSub->pEList->nExpr);

  130861.       goto select_end;

  130862.     }

  130863. 

  130864.     /* Do not try to flatten an aggregate subquery.

  130865.     **

  130866.     ** Flattening an aggregate subquery is only possible if the outer query

  130867.     ** is not a join.  But if the outer query is not a join, then the subquery

  130868.     ** will be implemented as a co-routine and there is no advantage to

  130869.     ** flattening in that case.

  130870.     */

  130871.     if( (pSub->selFlags & SF_Aggregate)!=0 ) continue;

  130872.     assert( pSub->pGroupBy==0 );

  130873. 

  130874.     /* If the outer query contains a "complex" result set (that is,

  130875.     ** if the result set of the outer query uses functions or subqueries)

  130876.     ** and if the subquery contains an ORDER BY clause and if

  130877.     ** it will be implemented as a co-routine, then do not flatten.  This

  130878.     ** restriction allows SQL constructs like this:

  130879.     **

  130880.     **  SELECT expensive_function(x)

  130881.     **    FROM (SELECT x FROM tab ORDER BY y LIMIT 10);

  130882.     **

  130883.     ** The expensive_function() is only computed on the 10 rows that

  130884.     ** are output, rather than every row of the table.

  130885.     **

  130886.     ** The requirement that the outer query have a complex result set

  130887.     ** means that flattening does occur on simpler SQL constraints without

  130888.     ** the expensive_function() like:

  130889.     **

  130890.     **  SELECT x FROM (SELECT x FROM tab ORDER BY y LIMIT 10);

  130891.     */

  130892.     if( pSub->pOrderBy!=0

  130893.      && i==0

  130894.      && (p->selFlags & SF_ComplexResult)!=0

  130895.      && (pTabList->nSrc==1

  130896.          || (pTabList->a[1].fg.jointype&(JT_LEFT|JT_CROSS))!=0)

  130897.     ){

  130898.       continue;

  130899.     }

  130900. 

  130901.     if( flattenSubquery(pParse, p, i, isAgg) ){

  130902.       if( pParse->nErr ) goto select_end;

  130903.       /* This subquery can be absorbed into its parent. */

  130904.       i = -1;

  130905.     }

  130906.     pTabList = p->pSrc;

  130907.     if( db->mallocFailed ) goto select_end;

  130908.     if( !IgnorableOrderby(pDest) ){

  130909.       sSort.pOrderBy = p->pOrderBy;

  130910.     }

  130911.   }

  130912. #endif

  130913. 

  130914. #ifndef SQLITE_OMIT_COMPOUND_SELECT

  130915.   /* Handle compound SELECT statements using the separate multiSelect()

  130916.   ** procedure.

  130917.   */

  130918.   if( p->pPrior ){

  130919.     rc = multiSelect(pParse, p, pDest);

  130920. #if SELECTTRACE_ENABLED

  130921.     SELECTTRACE(0x1,pParse,p,("end compound-select processing\n"));

  130922.     if( (sqlite3SelectTrace & 0x2000)!=0 && ExplainQueryPlanParent(pParse)==0 ){

  130923.       sqlite3TreeViewSelect(0, p, 0);

  130924.     }

  130925. #endif

  130926.     if( p->pNext==0 ) ExplainQueryPlanPop(pParse);

  130927.     return rc;

  130928.   }

  130929. #endif

  130930. 

  130931.   /* Do the WHERE-clause constant propagation optimization if this is

  130932.   ** a join.  No need to speed time on this operation for non-join queries

  130933.   ** as the equivalent optimization will be handled by query planner in

  130934.   ** sqlite3WhereBegin().

  130935.   */

  130936.   if( pTabList->nSrc>1

  130937.    && OptimizationEnabled(db, SQLITE_PropagateConst)

  130938.    && propagateConstants(pParse, p)

  130939.   ){

  130940. #if SELECTTRACE_ENABLED

  130941.     if( sqlite3SelectTrace & 0x100 ){

  130942.       SELECTTRACE(0x100,pParse,p,("After constant propagation:\n"));

  130943.       sqlite3TreeViewSelect(0, p, 0);

  130944.     }

  130945. #endif

  130946.   }else{

  130947.     SELECTTRACE(0x100,pParse,p,("Constant propagation not helpful\n"));

  130948.   }

  130949. 

  130950. #ifdef SQLITE_COUNTOFVIEW_OPTIMIZATION

  130951.   if( OptimizationEnabled(db, SQLITE_QueryFlattener|SQLITE_CountOfView)

  130952.    && countOfViewOptimization(pParse, p)

  130953.   ){

  130954.     if( db->mallocFailed ) goto select_end;

  130955.     pEList = p->pEList;

  130956.     pTabList = p->pSrc;

  130957.   }

  130958. #endif

  130959. 

  130960.   /* For each term in the FROM clause, do two things:

  130961.   ** (1) Authorized unreferenced tables

  130962.   ** (2) Generate code for all sub-queries

  130963.   */

  130964.   for(i=0; i<pTabList->nSrc; i++){

  130965.     struct SrcList_item *pItem = &pTabList->a[i];

  130966.     SelectDest dest;

  130967.     Select *pSub;

  130968. #if !defined(SQLITE_OMIT_SUBQUERY) || !defined(SQLITE_OMIT_VIEW)

  130969.     const char *zSavedAuthContext;

  130970. #endif

  130971. 

  130972.     /* Issue SQLITE_READ authorizations with a fake column name for any

  130973.     ** tables that are referenced but from which no values are extracted.

  130974.     ** Examples of where these kinds of null SQLITE_READ authorizations

  130975.     ** would occur:

  130976.     **

  130977.     **     SELECT count(*) FROM t1;   -- SQLITE_READ t1.""

  130978.     **     SELECT t1.* FROM t1, t2;   -- SQLITE_READ t2.""

  130979.     **

  130980.     ** The fake column name is an empty string.  It is possible for a table to

  130981.     ** have a column named by the empty string, in which case there is no way to

  130982.     ** distinguish between an unreferenced table and an actual reference to the

  130983.     ** "" column. The original design was for the fake column name to be a NULL,

  130984.     ** which would be unambiguous.  But legacy authorization callbacks might

  130985.     ** assume the column name is non-NULL and segfault.  The use of an empty

  130986.     ** string for the fake column name seems safer.

  130987.     */

  130988.     if( pItem->colUsed==0 ){

  130989.       sqlite3AuthCheck(pParse, SQLITE_READ, pItem->zName, "", pItem->zDatabase);

  130990.     }

  130991. 

  130992. #if !defined(SQLITE_OMIT_SUBQUERY) || !defined(SQLITE_OMIT_VIEW)

  130993.     /* Generate code for all sub-queries in the FROM clause

  130994.     */

  130995.     pSub = pItem->pSelect;

  130996.     if( pSub==0 ) continue;

  130997. 

  130998.     /* The code for a subquery should only be generated once, though it is

  130999.     ** technically harmless for it to be generated multiple times. The

  131000.     ** following assert() will detect if something changes to cause

  131001.     ** the same subquery to be coded multiple times, as a signal to the

  131002.     ** developers to try to optimize the situation. */

  131003.     assert( pItem->addrFillSub==0 );

  131004. 

  131005.     /* Increment Parse.nHeight by the height of the largest expression

  131006.     ** tree referred to by this, the parent select. The child select

  131007.     ** may contain expression trees of at most

  131008.     ** (SQLITE_MAX_EXPR_DEPTH-Parse.nHeight) height. This is a bit

  131009.     ** more conservative than necessary, but much easier than enforcing

  131010.     ** an exact limit.

  131011.     */

  131012.     pParse->nHeight += sqlite3SelectExprHeight(p);

  131013. 

  131014.     /* Make copies of constant WHERE-clause terms in the outer query down

  131015.     ** inside the subquery.  This can help the subquery to run more efficiently.

  131016.     */

  131017.     if( OptimizationEnabled(db, SQLITE_PushDown)

  131018.      && pushDownWhereTerms(pParse, pSub, p->pWhere, pItem->iCursor,

  131019.                            (pItem->fg.jointype & JT_OUTER)!=0)

  131020.     ){

  131021. #if SELECTTRACE_ENABLED

  131022.       if( sqlite3SelectTrace & 0x100 ){

  131023.         SELECTTRACE(0x100,pParse,p,

  131024.             ("After WHERE-clause push-down into subquery %d:\n", pSub->selId));

  131025.         sqlite3TreeViewSelect(0, p, 0);

  131026.       }

  131027. #endif

  131028.     }else{

  131029.       SELECTTRACE(0x100,pParse,p,("Push-down not possible\n"));

  131030.     }

  131031. 

  131032.     zSavedAuthContext = pParse->zAuthContext;

  131033.     pParse->zAuthContext = pItem->zName;

  131034. 

  131035.     /* Generate code to implement the subquery

  131036.     **

  131037.     ** The subquery is implemented as a co-routine if the subquery is

  131038.     ** guaranteed to be the outer loop (so that it does not need to be

  131039.     ** computed more than once)

  131040.     **

  131041.     ** TODO: Are there other reasons beside (1) to use a co-routine

  131042.     ** implementation?

  131043.     */

  131044.     if( i==0

  131045.      && (pTabList->nSrc==1

  131046.             || (pTabList->a[1].fg.jointype&(JT_LEFT|JT_CROSS))!=0)  /* (1) */

  131047.     ){

  131048.       /* Implement a co-routine that will return a single row of the result

  131049.       ** set on each invocation.

  131050.       */

  131051.       int addrTop = sqlite3VdbeCurrentAddr(v)+1;

  131052.      

  131053.       pItem->regReturn = ++pParse->nMem;

  131054.       sqlite3VdbeAddOp3(v, OP_InitCoroutine, pItem->regReturn, 0, addrTop);

  131055.       VdbeComment((v, "%s", pItem->pTab->zName));

  131056.       pItem->addrFillSub = addrTop;

  131057.       sqlite3SelectDestInit(&dest, SRT_Coroutine, pItem->regReturn);

  131058.       ExplainQueryPlan((pParse, 1, "CO-ROUTINE %u", pSub->selId));

  131059.       sqlite3Select(pParse, pSub, &dest);

  131060.       pItem->pTab->nRowLogEst = pSub->nSelectRow;

  131061.       pItem->fg.viaCoroutine = 1;

  131062.       pItem->regResult = dest.iSdst;

  131063.       sqlite3VdbeEndCoroutine(v, pItem->regReturn);

  131064.       sqlite3VdbeJumpHere(v, addrTop-1);

  131065.       sqlite3ClearTempRegCache(pParse);

  131066.     }else{

  131067.       /* Generate a subroutine that will fill an ephemeral table with

  131068.       ** the content of this subquery.  pItem->addrFillSub will point

  131069.       ** to the address of the generated subroutine.  pItem->regReturn

  131070.       ** is a register allocated to hold the subroutine return address

  131071.       */

  131072.       int topAddr;

  131073.       int onceAddr = 0;

  131074.       int retAddr;

  131075.       struct SrcList_item *pPrior;

  131076. 

  131077.       assert( pItem->addrFillSub==0 );

  131078.       pItem->regReturn = ++pParse->nMem;

  131079.       topAddr = sqlite3VdbeAddOp2(v, OP_Integer, 0, pItem->regReturn);

  131080.       pItem->addrFillSub = topAddr+1;

  131081.       if( pItem->fg.isCorrelated==0 ){

  131082.         /* If the subquery is not correlated and if we are not inside of

  131083.         ** a trigger, then we only need to compute the value of the subquery

  131084.         ** once. */

  131085.         onceAddr = sqlite3VdbeAddOp0(v, OP_Once); VdbeCoverage(v);

  131086.         VdbeComment((v, "materialize \"%s\"", pItem->pTab->zName));

  131087.       }else{

  131088.         VdbeNoopComment((v, "materialize \"%s\"", pItem->pTab->zName));

  131089.       }

  131090.       pPrior = isSelfJoinView(pTabList, pItem);

  131091.       if( pPrior ){

  131092.         sqlite3VdbeAddOp2(v, OP_OpenDup, pItem->iCursor, pPrior->iCursor);

  131093.         assert( pPrior->pSelect!=0 );

  131094.         pSub->nSelectRow = pPrior->pSelect->nSelectRow;

  131095.       }else{

  131096.         sqlite3SelectDestInit(&dest, SRT_EphemTab, pItem->iCursor);

  131097.         ExplainQueryPlan((pParse, 1, "MATERIALIZE %u", pSub->selId));

  131098.         sqlite3Select(pParse, pSub, &dest);

  131099.       }

  131100.       pItem->pTab->nRowLogEst = pSub->nSelectRow;

  131101.       if( onceAddr ) sqlite3VdbeJumpHere(v, onceAddr);

  131102.       retAddr = sqlite3VdbeAddOp1(v, OP_Return, pItem->regReturn);

  131103.       VdbeComment((v, "end %s", pItem->pTab->zName));

  131104.       sqlite3VdbeChangeP1(v, topAddr, retAddr);

  131105.       sqlite3ClearTempRegCache(pParse);

  131106.     }

  131107.     if( db->mallocFailed ) goto select_end;

  131108.     pParse->nHeight -= sqlite3SelectExprHeight(p);

  131109.     pParse->zAuthContext = zSavedAuthContext;

  131110. #endif

  131111.   }

  131112. 

  131113.   /* Various elements of the SELECT copied into local variables for

  131114.   ** convenience */

  131115.   pEList = p->pEList;

  131116.   pWhere = p->pWhere;

  131117.   pGroupBy = p->pGroupBy;

  131118.   pHaving = p->pHaving;

  131119.   sDistinct.isTnct = (p->selFlags & SF_Distinct)!=0;

  131120. 

  131121. #if SELECTTRACE_ENABLED

  131122.   if( sqlite3SelectTrace & 0x400 ){

  131123.     SELECTTRACE(0x400,pParse,p,("After all FROM-clause analysis:\n"));

  131124.     sqlite3TreeViewSelect(0, p, 0);

  131125.   }

  131126. #endif

  131127. 

  131128.   /* If the query is DISTINCT with an ORDER BY but is not an aggregate, and 

  131129.   ** if the select-list is the same as the ORDER BY list, then this query

  131130.   ** can be rewritten as a GROUP BY. In other words, this:

  131131.   **

  131132.   **     SELECT DISTINCT xyz FROM ... ORDER BY xyz

  131133.   **

  131134.   ** is transformed to:

  131135.   **

  131136.   **     SELECT xyz FROM ... GROUP BY xyz ORDER BY xyz

  131137.   **

  131138.   ** The second form is preferred as a single index (or temp-table) may be 

  131139.   ** used for both the ORDER BY and DISTINCT processing. As originally 

  131140.   ** written the query must use a temp-table for at least one of the ORDER 

  131141.   ** BY and DISTINCT, and an index or separate temp-table for the other.

  131142.   */

  131143.   if( (p->selFlags & (SF_Distinct|SF_Aggregate))==SF_Distinct 

  131144.    && sqlite3ExprListCompare(sSort.pOrderBy, pEList, -1)==0

  131145.   ){

  131146.     p->selFlags &= ~SF_Distinct;

  131147.     pGroupBy = p->pGroupBy = sqlite3ExprListDup(db, pEList, 0);

  131148.     /* Notice that even thought SF_Distinct has been cleared from p->selFlags,

  131149.     ** the sDistinct.isTnct is still set.  Hence, isTnct represents the

  131150.     ** original setting of the SF_Distinct flag, not the current setting */

  131151.     assert( sDistinct.isTnct );

  131152. 

  131153. #if SELECTTRACE_ENABLED

  131154.     if( sqlite3SelectTrace & 0x400 ){

  131155.       SELECTTRACE(0x400,pParse,p,("Transform DISTINCT into GROUP BY:\n"));

  131156.       sqlite3TreeViewSelect(0, p, 0);

  131157.     }

  131158. #endif

  131159.   }

  131160. 

  131161.   /* If there is an ORDER BY clause, then create an ephemeral index to

  131162.   ** do the sorting.  But this sorting ephemeral index might end up

  131163.   ** being unused if the data can be extracted in pre-sorted order.

  131164.   ** If that is the case, then the OP_OpenEphemeral instruction will be

  131165.   ** changed to an OP_Noop once we figure out that the sorting index is

  131166.   ** not needed.  The sSort.addrSortIndex variable is used to facilitate

  131167.   ** that change.

  131168.   */

  131169.   if( sSort.pOrderBy ){

  131170.     KeyInfo *pKeyInfo;

  131171.     pKeyInfo = sqlite3KeyInfoFromExprList(

  131172.         pParse, sSort.pOrderBy, 0, pEList->nExpr);

  131173.     sSort.iECursor = pParse->nTab++;

  131174.     sSort.addrSortIndex =

  131175.       sqlite3VdbeAddOp4(v, OP_OpenEphemeral,

  131176.           sSort.iECursor, sSort.pOrderBy->nExpr+1+pEList->nExpr, 0,

  131177.           (char*)pKeyInfo, P4_KEYINFO

  131178.       );

  131179.   }else{

  131180.     sSort.addrSortIndex = -1;

  131181.   }

  131182. 

  131183.   /* If the output is destined for a temporary table, open that table.

  131184.   */

  131185.   if( pDest->eDest==SRT_EphemTab ){

  131186.     sqlite3VdbeAddOp2(v, OP_OpenEphemeral, pDest->iSDParm, pEList->nExpr);

  131187.   }

  131188. 

  131189.   /* Set the limiter.

  131190.   */

  131191.   iEnd = sqlite3VdbeMakeLabel(pParse);

  131192.   if( (p->selFlags & SF_FixedLimit)==0 ){

  131193.     p->nSelectRow = 320;  /* 4 billion rows */

  131194.   }

  131195.   computeLimitRegisters(pParse, p, iEnd);

  131196.   if( p->iLimit==0 && sSort.addrSortIndex>=0 ){

  131197.     sqlite3VdbeChangeOpcode(v, sSort.addrSortIndex, OP_SorterOpen);

  131198.     sSort.sortFlags |= SORTFLAG_UseSorter;

  131199.   }

  131200. 

  131201.   /* Open an ephemeral index to use for the distinct set.

  131202.   */

  131203.   if( p->selFlags & SF_Distinct ){

  131204.     sDistinct.tabTnct = pParse->nTab++;

  131205.     sDistinct.addrTnct = sqlite3VdbeAddOp4(v, OP_OpenEphemeral,

  131206.                        sDistinct.tabTnct, 0, 0,

  131207.                        (char*)sqlite3KeyInfoFromExprList(pParse, p->pEList,0,0),

  131208.                        P4_KEYINFO);

  131209.     sqlite3VdbeChangeP5(v, BTREE_UNORDERED);

  131210.     sDistinct.eTnctType = WHERE_DISTINCT_UNORDERED;

  131211.   }else{

  131212.     sDistinct.eTnctType = WHERE_DISTINCT_NOOP;

  131213.   }

  131214. 

  131215.   if( !isAgg && pGroupBy==0 ){

  131216.     /* No aggregate functions and no GROUP BY clause */

  131217.     u16 wctrlFlags = (sDistinct.isTnct ? WHERE_WANT_DISTINCT : 0)

  131218.                    | (p->selFlags & SF_FixedLimit);

  131219. #ifndef SQLITE_OMIT_WINDOWFUNC

  131220.     Window *pWin = p->pWin;      /* Master window object (or NULL) */

  131221.     if( pWin ){

  131222.       sqlite3WindowCodeInit(pParse, pWin);

  131223.     }

  131224. #endif

  131225.     assert( WHERE_USE_LIMIT==SF_FixedLimit );

  131226. 

  131227. 

  131228.     /* Begin the database scan. */

  131229.     SELECTTRACE(1,pParse,p,("WhereBegin\n"));

  131230.     pWInfo = sqlite3WhereBegin(pParse, pTabList, pWhere, sSort.pOrderBy,

  131231.                                p->pEList, wctrlFlags, p->nSelectRow);

  131232.     if( pWInfo==0 ) goto select_end;

  131233.     if( sqlite3WhereOutputRowCount(pWInfo) < p->nSelectRow ){

  131234.       p->nSelectRow = sqlite3WhereOutputRowCount(pWInfo);

  131235.     }

  131236.     if( sDistinct.isTnct && sqlite3WhereIsDistinct(pWInfo) ){

  131237.       sDistinct.eTnctType = sqlite3WhereIsDistinct(pWInfo);

  131238.     }

  131239.     if( sSort.pOrderBy ){

  131240.       sSort.nOBSat = sqlite3WhereIsOrdered(pWInfo);

  131241.       sSort.labelOBLopt = sqlite3WhereOrderByLimitOptLabel(pWInfo);

  131242.       if( sSort.nOBSat==sSort.pOrderBy->nExpr ){

  131243.         sSort.pOrderBy = 0;

  131244.       }

  131245.     }

  131246. 

  131247.     /* If sorting index that was created by a prior OP_OpenEphemeral 

  131248.     ** instruction ended up not being needed, then change the OP_OpenEphemeral

  131249.     ** into an OP_Noop.

  131250.     */

  131251.     if( sSort.addrSortIndex>=0 && sSort.pOrderBy==0 ){

  131252.       sqlite3VdbeChangeToNoop(v, sSort.addrSortIndex);

  131253.     }

  131254. 

  131255.     assert( p->pEList==pEList );

  131256. #ifndef SQLITE_OMIT_WINDOWFUNC

  131257.     if( pWin ){

  131258.       int addrGosub = sqlite3VdbeMakeLabel(pParse);

  131259.       int iCont = sqlite3VdbeMakeLabel(pParse);

  131260.       int iBreak = sqlite3VdbeMakeLabel(pParse);

  131261.       int regGosub = ++pParse->nMem;

  131262. 

  131263.       sqlite3WindowCodeStep(pParse, p, pWInfo, regGosub, addrGosub);

  131264. 

  131265.       sqlite3VdbeAddOp2(v, OP_Goto, 0, iBreak);

  131266.       sqlite3VdbeResolveLabel(v, addrGosub);

  131267.       VdbeNoopComment((v, "inner-loop subroutine"));

  131268.       sSort.labelOBLopt = 0;

  131269.       selectInnerLoop(pParse, p, -1, &sSort, &sDistinct, pDest, iCont, iBreak);

  131270.       sqlite3VdbeResolveLabel(v, iCont);

  131271.       sqlite3VdbeAddOp1(v, OP_Return, regGosub);

  131272.       VdbeComment((v, "end inner-loop subroutine"));

  131273.       sqlite3VdbeResolveLabel(v, iBreak);

  131274.     }else

  131275. #endif /* SQLITE_OMIT_WINDOWFUNC */

  131276.     {

  131277.       /* Use the standard inner loop. */

  131278.       selectInnerLoop(pParse, p, -1, &sSort, &sDistinct, pDest,

  131279.           sqlite3WhereContinueLabel(pWInfo),

  131280.           sqlite3WhereBreakLabel(pWInfo));

  131281. 

  131282.       /* End the database scan loop.

  131283.       */

  131284.       sqlite3WhereEnd(pWInfo);

  131285.     }

  131286.   }else{

  131287.     /* This case when there exist aggregate functions or a GROUP BY clause

  131288.     ** or both */

  131289.     NameContext sNC;    /* Name context for processing aggregate information */

  131290.     int iAMem;          /* First Mem address for storing current GROUP BY */

  131291.     int iBMem;          /* First Mem address for previous GROUP BY */

  131292.     int iUseFlag;       /* Mem address holding flag indicating that at least

  131293.                         ** one row of the input to the aggregator has been

  131294.                         ** processed */

  131295.     int iAbortFlag;     /* Mem address which causes query abort if positive */

  131296.     int groupBySort;    /* Rows come from source in GROUP BY order */

  131297.     int addrEnd;        /* End of processing for this SELECT */

  131298.     int sortPTab = 0;   /* Pseudotable used to decode sorting results */

  131299.     int sortOut = 0;    /* Output register from the sorter */

  131300.     int orderByGrp = 0; /* True if the GROUP BY and ORDER BY are the same */

  131301. 

  131302.     /* Remove any and all aliases between the result set and the

  131303.     ** GROUP BY clause.

  131304.     */

  131305.     if( pGroupBy ){

  131306.       int k;                        /* Loop counter */

  131307.       struct ExprList_item *pItem;  /* For looping over expression in a list */

  131308. 

  131309.       for(k=p->pEList->nExpr, pItem=p->pEList->a; k>0; k--, pItem++){

  131310.         pItem->u.x.iAlias = 0;

  131311.       }

  131312.       for(k=pGroupBy->nExpr, pItem=pGroupBy->a; k>0; k--, pItem++){

  131313.         pItem->u.x.iAlias = 0;

  131314.       }

  131315.       assert( 66==sqlite3LogEst(100) );

  131316.       if( p->nSelectRow>66 ) p->nSelectRow = 66;

  131317.     }else{

  131318.       assert( 0==sqlite3LogEst(1) );

  131319.       p->nSelectRow = 0;

  131320.     }

  131321. 

  131322.     /* If there is both a GROUP BY and an ORDER BY clause and they are

  131323.     ** identical, then it may be possible to disable the ORDER BY clause 

  131324.     ** on the grounds that the GROUP BY will cause elements to come out 

  131325.     ** in the correct order. It also may not - the GROUP BY might use a

  131326.     ** database index that causes rows to be grouped together as required

  131327.     ** but not actually sorted. Either way, record the fact that the

  131328.     ** ORDER BY and GROUP BY clauses are the same by setting the orderByGrp

  131329.     ** variable.  */

  131330.     if( sqlite3ExprListCompare(pGroupBy, sSort.pOrderBy, -1)==0 ){

  131331.       orderByGrp = 1;

  131332.     }

  131333.  

  131334.     /* Create a label to jump to when we want to abort the query */

  131335.     addrEnd = sqlite3VdbeMakeLabel(pParse);

  131336. 

  131337.     /* Convert TK_COLUMN nodes into TK_AGG_COLUMN and make entries in

  131338.     ** sAggInfo for all TK_AGG_FUNCTION nodes in expressions of the

  131339.     ** SELECT statement.

  131340.     */

  131341.     memset(&sNC, 0, sizeof(sNC));

  131342.     sNC.pParse = pParse;

  131343.     sNC.pSrcList = pTabList;

  131344.     sNC.uNC.pAggInfo = &sAggInfo;

  131345.     VVA_ONLY( sNC.ncFlags = NC_UAggInfo; )

  131346.     sAggInfo.mnReg = pParse->nMem+1;

  131347.     sAggInfo.nSortingColumn = pGroupBy ? pGroupBy->nExpr : 0;

  131348.     sAggInfo.pGroupBy = pGroupBy;

  131349.     sqlite3ExprAnalyzeAggList(&sNC, pEList);

  131350.     sqlite3ExprAnalyzeAggList(&sNC, sSort.pOrderBy);

  131351.     if( pHaving ){

  131352.       if( pGroupBy ){

  131353.         assert( pWhere==p->pWhere );

  131354.         assert( pHaving==p->pHaving );

  131355.         assert( pGroupBy==p->pGroupBy );

  131356.         havingToWhere(pParse, p);

  131357.         pWhere = p->pWhere;

  131358.       }

  131359.       sqlite3ExprAnalyzeAggregates(&sNC, pHaving);

  131360.     }

  131361.     sAggInfo.nAccumulator = sAggInfo.nColumn;

  131362.     if( p->pGroupBy==0 && p->pHaving==0 && sAggInfo.nFunc==1 ){

  131363.       minMaxFlag = minMaxQuery(db, sAggInfo.aFunc[0].pExpr, &pMinMaxOrderBy);

  131364.     }else{

  131365.       minMaxFlag = WHERE_ORDERBY_NORMAL;

  131366.     }

  131367.     for(i=0; i<sAggInfo.nFunc; i++){

  131368.       assert( !ExprHasProperty(sAggInfo.aFunc[i].pExpr, EP_xIsSelect) );

  131369.       sNC.ncFlags |= NC_InAggFunc;

  131370.       sqlite3ExprAnalyzeAggList(&sNC, sAggInfo.aFunc[i].pExpr->x.pList);

  131371.       sNC.ncFlags &= ~NC_InAggFunc;

  131372.     }

  131373.     sAggInfo.mxReg = pParse->nMem;

  131374.     if( db->mallocFailed ) goto select_end;

  131375. #if SELECTTRACE_ENABLED

  131376.     if( sqlite3SelectTrace & 0x400 ){

  131377.       int ii;

  131378.       SELECTTRACE(0x400,pParse,p,("After aggregate analysis:\n"));

  131379.       sqlite3TreeViewSelect(0, p, 0);

  131380.       for(ii=0; ii<sAggInfo.nColumn; ii++){

  131381.         sqlite3DebugPrintf("agg-column[%d] iMem=%d\n",

  131382.             ii, sAggInfo.aCol[ii].iMem);

  131383.         sqlite3TreeViewExpr(0, sAggInfo.aCol[ii].pExpr, 0);

  131384.       }

  131385.       for(ii=0; ii<sAggInfo.nFunc; ii++){

  131386.         sqlite3DebugPrintf("agg-func[%d]: iMem=%d\n",

  131387.             ii, sAggInfo.aFunc[ii].iMem);

  131388.         sqlite3TreeViewExpr(0, sAggInfo.aFunc[ii].pExpr, 0);

  131389.       }

  131390.     }

  131391. #endif

  131392. 

  131393. 

  131394.     /* Processing for aggregates with GROUP BY is very different and

  131395.     ** much more complex than aggregates without a GROUP BY.

  131396.     */

  131397.     if( pGroupBy ){

  131398.       KeyInfo *pKeyInfo;  /* Keying information for the group by clause */

  131399.       int addr1;          /* A-vs-B comparision jump */

  131400.       int addrOutputRow;  /* Start of subroutine that outputs a result row */

  131401.       int regOutputRow;   /* Return address register for output subroutine */

  131402.       int addrSetAbort;   /* Set the abort flag and return */

  131403.       int addrTopOfLoop;  /* Top of the input loop */

  131404.       int addrSortingIdx; /* The OP_OpenEphemeral for the sorting index */

  131405.       int addrReset;      /* Subroutine for resetting the accumulator */

  131406.       int regReset;       /* Return address register for reset subroutine */

  131407. 

  131408.       /* If there is a GROUP BY clause we might need a sorting index to

  131409.       ** implement it.  Allocate that sorting index now.  If it turns out

  131410.       ** that we do not need it after all, the OP_SorterOpen instruction

  131411.       ** will be converted into a Noop.  

  131412.       */

  131413.       sAggInfo.sortingIdx = pParse->nTab++;

  131414.       pKeyInfo = sqlite3KeyInfoFromExprList(pParse,pGroupBy,0,sAggInfo.nColumn);

  131415.       addrSortingIdx = sqlite3VdbeAddOp4(v, OP_SorterOpen, 

  131416.           sAggInfo.sortingIdx, sAggInfo.nSortingColumn, 

  131417.           0, (char*)pKeyInfo, P4_KEYINFO);

  131418. 

  131419.       /* Initialize memory locations used by GROUP BY aggregate processing

  131420.       */

  131421.       iUseFlag = ++pParse->nMem;

  131422.       iAbortFlag = ++pParse->nMem;

  131423.       regOutputRow = ++pParse->nMem;

  131424.       addrOutputRow = sqlite3VdbeMakeLabel(pParse);

  131425.       regReset = ++pParse->nMem;

  131426.       addrReset = sqlite3VdbeMakeLabel(pParse);

  131427.       iAMem = pParse->nMem + 1;

  131428.       pParse->nMem += pGroupBy->nExpr;

  131429.       iBMem = pParse->nMem + 1;

  131430.       pParse->nMem += pGroupBy->nExpr;

  131431.       sqlite3VdbeAddOp2(v, OP_Integer, 0, iAbortFlag);

  131432.       VdbeComment((v, "clear abort flag"));

  131433.       sqlite3VdbeAddOp3(v, OP_Null, 0, iAMem, iAMem+pGroupBy->nExpr-1);

  131434. 

  131435.       /* Begin a loop that will extract all source rows in GROUP BY order.

  131436.       ** This might involve two separate loops with an OP_Sort in between, or

  131437.       ** it might be a single loop that uses an index to extract information

  131438.       ** in the right order to begin with.

  131439.       */

  131440.       sqlite3VdbeAddOp2(v, OP_Gosub, regReset, addrReset);

  131441.       SELECTTRACE(1,pParse,p,("WhereBegin\n"));

  131442.       pWInfo = sqlite3WhereBegin(pParse, pTabList, pWhere, pGroupBy, 0,

  131443.           WHERE_GROUPBY | (orderByGrp ? WHERE_SORTBYGROUP : 0), 0

  131444.       );

  131445.       if( pWInfo==0 ) goto select_end;

  131446.       if( sqlite3WhereIsOrdered(pWInfo)==pGroupBy->nExpr ){

  131447.         /* The optimizer is able to deliver rows in group by order so

  131448.         ** we do not have to sort.  The OP_OpenEphemeral table will be

  131449.         ** cancelled later because we still need to use the pKeyInfo

  131450.         */

  131451.         groupBySort = 0;

  131452.       }else{

  131453.         /* Rows are coming out in undetermined order.  We have to push

  131454.         ** each row into a sorting index, terminate the first loop,

  131455.         ** then loop over the sorting index in order to get the output

  131456.         ** in sorted order

  131457.         */

  131458.         int regBase;

  131459.         int regRecord;

  131460.         int nCol;

  131461.         int nGroupBy;

  131462. 

  131463.         explainTempTable(pParse, 

  131464.             (sDistinct.isTnct && (p->selFlags&SF_Distinct)==0) ?

  131465.                     "DISTINCT" : "GROUP BY");

  131466. 

  131467.         groupBySort = 1;

  131468.         nGroupBy = pGroupBy->nExpr;

  131469.         nCol = nGroupBy;

  131470.         j = nGroupBy;

  131471.         for(i=0; i<sAggInfo.nColumn; i++){

  131472.           if( sAggInfo.aCol[i].iSorterColumn>=j ){

  131473.             nCol++;

  131474.             j++;

  131475.           }

  131476.         }

  131477.         regBase = sqlite3GetTempRange(pParse, nCol);

  131478.         sqlite3ExprCodeExprList(pParse, pGroupBy, regBase, 0, 0);

  131479.         j = nGroupBy;

  131480.         for(i=0; i<sAggInfo.nColumn; i++){

  131481.           struct AggInfo_col *pCol = &sAggInfo.aCol[i];

  131482.           if( pCol->iSorterColumn>=j ){

  131483.             int r1 = j + regBase;

  131484.             sqlite3ExprCodeGetColumnOfTable(v,

  131485.                                pCol->pTab, pCol->iTable, pCol->iColumn, r1);

  131486.             j++;

  131487.           }

  131488.         }

  131489.         regRecord = sqlite3GetTempReg(pParse);

  131490.         sqlite3VdbeAddOp3(v, OP_MakeRecord, regBase, nCol, regRecord);

  131491.         sqlite3VdbeAddOp2(v, OP_SorterInsert, sAggInfo.sortingIdx, regRecord);

  131492.         sqlite3ReleaseTempReg(pParse, regRecord);

  131493.         sqlite3ReleaseTempRange(pParse, regBase, nCol);

  131494.         sqlite3WhereEnd(pWInfo);

  131495.         sAggInfo.sortingIdxPTab = sortPTab = pParse->nTab++;

  131496.         sortOut = sqlite3GetTempReg(pParse);

  131497.         sqlite3VdbeAddOp3(v, OP_OpenPseudo, sortPTab, sortOut, nCol);

  131498.         sqlite3VdbeAddOp2(v, OP_SorterSort, sAggInfo.sortingIdx, addrEnd);

  131499.         VdbeComment((v, "GROUP BY sort")); VdbeCoverage(v);

  131500.         sAggInfo.useSortingIdx = 1;

  131501.       }

  131502. 

  131503.       /* If the index or temporary table used by the GROUP BY sort

  131504.       ** will naturally deliver rows in the order required by the ORDER BY

  131505.       ** clause, cancel the ephemeral table open coded earlier.

  131506.       **

  131507.       ** This is an optimization - the correct answer should result regardless.

  131508.       ** Use the SQLITE_GroupByOrder flag with SQLITE_TESTCTRL_OPTIMIZER to 

  131509.       ** disable this optimization for testing purposes.  */

  131510.       if( orderByGrp && OptimizationEnabled(db, SQLITE_GroupByOrder) 

  131511.        && (groupBySort || sqlite3WhereIsSorted(pWInfo))

  131512.       ){

  131513.         sSort.pOrderBy = 0;

  131514.         sqlite3VdbeChangeToNoop(v, sSort.addrSortIndex);

  131515.       }

  131516. 

  131517.       /* Evaluate the current GROUP BY terms and store in b0, b1, b2...

  131518.       ** (b0 is memory location iBMem+0, b1 is iBMem+1, and so forth)

  131519.       ** Then compare the current GROUP BY terms against the GROUP BY terms

  131520.       ** from the previous row currently stored in a0, a1, a2...

  131521.       */

  131522.       addrTopOfLoop = sqlite3VdbeCurrentAddr(v);

  131523.       if( groupBySort ){

  131524.         sqlite3VdbeAddOp3(v, OP_SorterData, sAggInfo.sortingIdx,

  131525.                           sortOut, sortPTab);

  131526.       }

  131527.       for(j=0; j<pGroupBy->nExpr; j++){

  131528.         if( groupBySort ){

  131529.           sqlite3VdbeAddOp3(v, OP_Column, sortPTab, j, iBMem+j);

  131530.         }else{

  131531.           sAggInfo.directMode = 1;

  131532.           sqlite3ExprCode(pParse, pGroupBy->a[j].pExpr, iBMem+j);

  131533.         }

  131534.       }

  131535.       sqlite3VdbeAddOp4(v, OP_Compare, iAMem, iBMem, pGroupBy->nExpr,

  131536.                           (char*)sqlite3KeyInfoRef(pKeyInfo), P4_KEYINFO);

  131537.       addr1 = sqlite3VdbeCurrentAddr(v);

  131538.       sqlite3VdbeAddOp3(v, OP_Jump, addr1+1, 0, addr1+1); VdbeCoverage(v);

  131539. 

  131540.       /* Generate code that runs whenever the GROUP BY changes.

  131541.       ** Changes in the GROUP BY are detected by the previous code

  131542.       ** block.  If there were no changes, this block is skipped.

  131543.       **

  131544.       ** This code copies current group by terms in b0,b1,b2,...

  131545.       ** over to a0,a1,a2.  It then calls the output subroutine

  131546.       ** and resets the aggregate accumulator registers in preparation

  131547.       ** for the next GROUP BY batch.

  131548.       */

  131549.       sqlite3ExprCodeMove(pParse, iBMem, iAMem, pGroupBy->nExpr);

  131550.       sqlite3VdbeAddOp2(v, OP_Gosub, regOutputRow, addrOutputRow);

  131551.       VdbeComment((v, "output one row"));

  131552.       sqlite3VdbeAddOp2(v, OP_IfPos, iAbortFlag, addrEnd); VdbeCoverage(v);

  131553.       VdbeComment((v, "check abort flag"));

  131554.       sqlite3VdbeAddOp2(v, OP_Gosub, regReset, addrReset);

  131555.       VdbeComment((v, "reset accumulator"));

  131556. 

  131557.       /* Update the aggregate accumulators based on the content of

  131558.       ** the current row

  131559.       */

  131560.       sqlite3VdbeJumpHere(v, addr1);

  131561.       updateAccumulator(pParse, iUseFlag, &sAggInfo);

  131562.       sqlite3VdbeAddOp2(v, OP_Integer, 1, iUseFlag);

  131563.       VdbeComment((v, "indicate data in accumulator"));

  131564. 

  131565.       /* End of the loop

  131566.       */

  131567.       if( groupBySort ){

  131568.         sqlite3VdbeAddOp2(v, OP_SorterNext, sAggInfo.sortingIdx, addrTopOfLoop);

  131569.         VdbeCoverage(v);

  131570.       }else{

  131571.         sqlite3WhereEnd(pWInfo);

  131572.         sqlite3VdbeChangeToNoop(v, addrSortingIdx);

  131573.       }

  131574. 

  131575.       /* Output the final row of result

  131576.       */

  131577.       sqlite3VdbeAddOp2(v, OP_Gosub, regOutputRow, addrOutputRow);

  131578.       VdbeComment((v, "output final row"));

  131579. 

  131580.       /* Jump over the subroutines

  131581.       */

  131582.       sqlite3VdbeGoto(v, addrEnd);

  131583. 

  131584.       /* Generate a subroutine that outputs a single row of the result

  131585.       ** set.  This subroutine first looks at the iUseFlag.  If iUseFlag

  131586.       ** is less than or equal to zero, the subroutine is a no-op.  If

  131587.       ** the processing calls for the query to abort, this subroutine

  131588.       ** increments the iAbortFlag memory location before returning in

  131589.       ** order to signal the caller to abort.

  131590.       */

  131591.       addrSetAbort = sqlite3VdbeCurrentAddr(v);

  131592.       sqlite3VdbeAddOp2(v, OP_Integer, 1, iAbortFlag);

  131593.       VdbeComment((v, "set abort flag"));

  131594.       sqlite3VdbeAddOp1(v, OP_Return, regOutputRow);

  131595.       sqlite3VdbeResolveLabel(v, addrOutputRow);

  131596.       addrOutputRow = sqlite3VdbeCurrentAddr(v);

  131597.       sqlite3VdbeAddOp2(v, OP_IfPos, iUseFlag, addrOutputRow+2);

  131598.       VdbeCoverage(v);

  131599.       VdbeComment((v, "Groupby result generator entry point"));

  131600.       sqlite3VdbeAddOp1(v, OP_Return, regOutputRow);

  131601.       finalizeAggFunctions(pParse, &sAggInfo);

  131602.       sqlite3ExprIfFalse(pParse, pHaving, addrOutputRow+1, SQLITE_JUMPIFNULL);

  131603.       selectInnerLoop(pParse, p, -1, &sSort,

  131604.                       &sDistinct, pDest,

  131605.                       addrOutputRow+1, addrSetAbort);

  131606.       sqlite3VdbeAddOp1(v, OP_Return, regOutputRow);

  131607.       VdbeComment((v, "end groupby result generator"));

  131608. 

  131609.       /* Generate a subroutine that will reset the group-by accumulator

  131610.       */

  131611.       sqlite3VdbeResolveLabel(v, addrReset);

  131612.       resetAccumulator(pParse, &sAggInfo);

  131613.       sqlite3VdbeAddOp2(v, OP_Integer, 0, iUseFlag);

  131614.       VdbeComment((v, "indicate accumulator empty"));

  131615.       sqlite3VdbeAddOp1(v, OP_Return, regReset);

  131616.      

  131617.     } /* endif pGroupBy.  Begin aggregate queries without GROUP BY: */

  131618.     else {

  131619. #ifndef SQLITE_OMIT_BTREECOUNT

  131620.       Table *pTab;

  131621.       if( (pTab = isSimpleCount(p, &sAggInfo))!=0 ){

  131622.         /* If isSimpleCount() returns a pointer to a Table structure, then

  131623.         ** the SQL statement is of the form:

  131624.         **

  131625.         **   SELECT count(*) FROM <tbl>

  131626.         **

  131627.         ** where the Table structure returned represents table <tbl>.

  131628.         **

  131629.         ** This statement is so common that it is optimized specially. The

  131630.         ** OP_Count instruction is executed either on the intkey table that

  131631.         ** contains the data for table <tbl> or on one of its indexes. It

  131632.         ** is better to execute the op on an index, as indexes are almost

  131633.         ** always spread across less pages than their corresponding tables.

  131634.         */

  131635.         const int iDb = sqlite3SchemaToIndex(pParse->db, pTab->pSchema);

  131636.         const int iCsr = pParse->nTab++;     /* Cursor to scan b-tree */

  131637.         Index *pIdx;                         /* Iterator variable */

  131638.         KeyInfo *pKeyInfo = 0;               /* Keyinfo for scanned index */

  131639.         Index *pBest = 0;                    /* Best index found so far */

  131640.         int iRoot = pTab->tnum;              /* Root page of scanned b-tree */

  131641. 

  131642.         sqlite3CodeVerifySchema(pParse, iDb);

  131643.         sqlite3TableLock(pParse, iDb, pTab->tnum, 0, pTab->zName);

  131644. 

  131645.         /* Search for the index that has the lowest scan cost.

  131646.         **

  131647.         ** (2011-04-15) Do not do a full scan of an unordered index.

  131648.         **

  131649.         ** (2013-10-03) Do not count the entries in a partial index.

  131650.         **

  131651.         ** In practice the KeyInfo structure will not be used. It is only 

  131652.         ** passed to keep OP_OpenRead happy.

  131653.         */

  131654.         if( !HasRowid(pTab) ) pBest = sqlite3PrimaryKeyIndex(pTab);

  131655.         for(pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext){

  131656.           if( pIdx->bUnordered==0

  131657.            && pIdx->szIdxRow<pTab->szTabRow

  131658.            && pIdx->pPartIdxWhere==0

  131659.            && (!pBest || pIdx->szIdxRow<pBest->szIdxRow)

  131660.           ){

  131661.             pBest = pIdx;

  131662.           }

  131663.         }

  131664.         if( pBest ){

  131665.           iRoot = pBest->tnum;

  131666.           pKeyInfo = sqlite3KeyInfoOfIndex(pParse, pBest);

  131667.         }

  131668. 

  131669.         /* Open a read-only cursor, execute the OP_Count, close the cursor. */

  131670.         sqlite3VdbeAddOp4Int(v, OP_OpenRead, iCsr, iRoot, iDb, 1);

  131671.         if( pKeyInfo ){

  131672.           sqlite3VdbeChangeP4(v, -1, (char *)pKeyInfo, P4_KEYINFO);

  131673.         }

  131674.         sqlite3VdbeAddOp2(v, OP_Count, iCsr, sAggInfo.aFunc[0].iMem);

  131675.         sqlite3VdbeAddOp1(v, OP_Close, iCsr);

  131676.         explainSimpleCount(pParse, pTab, pBest);

  131677.       }else

  131678. #endif /* SQLITE_OMIT_BTREECOUNT */

  131679.       {

  131680.         int regAcc = 0;           /* "populate accumulators" flag */

  131681. 

  131682.         /* If there are accumulator registers but no min() or max() functions,

  131683.         ** allocate register regAcc. Register regAcc will contain 0 the first

  131684.         ** time the inner loop runs, and 1 thereafter. The code generated

  131685.         ** by updateAccumulator() only updates the accumulator registers if

  131686.         ** regAcc contains 0.  */

  131687.         if( sAggInfo.nAccumulator ){

  131688.           for(i=0; i<sAggInfo.nFunc; i++){

  131689.             if( sAggInfo.aFunc[i].pFunc->funcFlags&SQLITE_FUNC_NEEDCOLL ) break;

  131690.           }

  131691.           if( i==sAggInfo.nFunc ){

  131692.             regAcc = ++pParse->nMem;

  131693.             sqlite3VdbeAddOp2(v, OP_Integer, 0, regAcc);

  131694.           }

  131695.         }

  131696. 

  131697.         /* This case runs if the aggregate has no GROUP BY clause.  The

  131698.         ** processing is much simpler since there is only a single row

  131699.         ** of output.

  131700.         */

  131701.         assert( p->pGroupBy==0 );

  131702.         resetAccumulator(pParse, &sAggInfo);

  131703. 

  131704.         /* If this query is a candidate for the min/max optimization, then

  131705.         ** minMaxFlag will have been previously set to either

  131706.         ** WHERE_ORDERBY_MIN or WHERE_ORDERBY_MAX and pMinMaxOrderBy will

  131707.         ** be an appropriate ORDER BY expression for the optimization.

  131708.         */

  131709.         assert( minMaxFlag==WHERE_ORDERBY_NORMAL || pMinMaxOrderBy!=0 );

  131710.         assert( pMinMaxOrderBy==0 || pMinMaxOrderBy->nExpr==1 );

  131711. 

  131712.         SELECTTRACE(1,pParse,p,("WhereBegin\n"));

  131713.         pWInfo = sqlite3WhereBegin(pParse, pTabList, pWhere, pMinMaxOrderBy,

  131714.                                    0, minMaxFlag, 0);

  131715.         if( pWInfo==0 ){

  131716.           goto select_end;

  131717.         }

  131718.         updateAccumulator(pParse, regAcc, &sAggInfo);

  131719.         if( regAcc ) sqlite3VdbeAddOp2(v, OP_Integer, 1, regAcc);

  131720.         if( sqlite3WhereIsOrdered(pWInfo)>0 ){

  131721.           sqlite3VdbeGoto(v, sqlite3WhereBreakLabel(pWInfo));

  131722.           VdbeComment((v, "%s() by index",

  131723.                 (minMaxFlag==WHERE_ORDERBY_MIN?"min":"max")));

  131724.         }

  131725.         sqlite3WhereEnd(pWInfo);

  131726.         finalizeAggFunctions(pParse, &sAggInfo);

  131727.       }

  131728. 

  131729.       sSort.pOrderBy = 0;

  131730.       sqlite3ExprIfFalse(pParse, pHaving, addrEnd, SQLITE_JUMPIFNULL);

  131731.       selectInnerLoop(pParse, p, -1, 0, 0, 

  131732.                       pDest, addrEnd, addrEnd);

  131733.     }

  131734.     sqlite3VdbeResolveLabel(v, addrEnd);

  131735.     

  131736.   } /* endif aggregate query */

  131737. 

  131738.   if( sDistinct.eTnctType==WHERE_DISTINCT_UNORDERED ){

  131739.     explainTempTable(pParse, "DISTINCT");

  131740.   }

  131741. 

  131742.   /* If there is an ORDER BY clause, then we need to sort the results

  131743.   ** and send them to the callback one by one.

  131744.   */

  131745.   if( sSort.pOrderBy ){

  131746.     explainTempTable(pParse,

  131747.                      sSort.nOBSat>0 ? "RIGHT PART OF ORDER BY":"ORDER BY");

  131748.     assert( p->pEList==pEList );

  131749.     generateSortTail(pParse, p, &sSort, pEList->nExpr, pDest);

  131750.   }

  131751. 

  131752.   /* Jump here to skip this query

  131753.   */

  131754.   sqlite3VdbeResolveLabel(v, iEnd);

  131755. 

  131756.   /* The SELECT has been coded. If there is an error in the Parse structure,

  131757.   ** set the return code to 1. Otherwise 0. */

  131758.   rc = (pParse->nErr>0);

  131759. 

  131760.   /* Control jumps to here if an error is encountered above, or upon

  131761.   ** successful coding of the SELECT.

  131762.   */

  131763. select_end:

  131764.   sqlite3ExprListDelete(db, pMinMaxOrderBy);

  131765.   sqlite3DbFree(db, sAggInfo.aCol);

  131766.   sqlite3DbFree(db, sAggInfo.aFunc);

  131767. #if SELECTTRACE_ENABLED

  131768.   SELECTTRACE(0x1,pParse,p,("end processing\n"));

  131769.   if( (sqlite3SelectTrace & 0x2000)!=0 && ExplainQueryPlanParent(pParse)==0 ){

  131770.     sqlite3TreeViewSelect(0, p, 0);

  131771.   }

  131772. #endif

  131773.   ExplainQueryPlanPop(pParse);

  131774.   return rc;

  131775. }

  131776. 

  131777. /************** End of select.c **********************************************/

  131778. /************** Begin file table.c *******************************************/

  131779. /*

  131780. ** 2001 September 15

  131781. **

  131782. ** The author disclaims copyright to this source code.  In place of

  131783. ** a legal notice, here is a blessing:

  131784. **

  131785. **    May you do good and not evil.

  131786. **    May you find forgiveness for yourself and forgive others.

  131787. **    May you share freely, never taking more than you give.

  131788. **

  131789. *************************************************************************

  131790. ** This file contains the sqlite3_get_table() and sqlite3_free_table()

  131791. ** interface routines.  These are just wrappers around the main

  131792. ** interface routine of sqlite3_exec().

  131793. **

  131794. ** These routines are in a separate files so that they will not be linked

  131795. ** if they are not used.

  131796. */

  131797. /* #include "sqliteInt.h" */

  131798. 

  131799. #ifndef SQLITE_OMIT_GET_TABLE

  131800. 

  131801. /*

  131802. ** This structure is used to pass data from sqlite3_get_table() through

  131803. ** to the callback function is uses to build the result.

  131804. */

  131805. typedef struct TabResult {

  131806.   char **azResult;   /* Accumulated output */

  131807.   char *zErrMsg;     /* Error message text, if an error occurs */

  131808.   u32 nAlloc;        /* Slots allocated for azResult[] */

  131809.   u32 nRow;          /* Number of rows in the result */

  131810.   u32 nColumn;       /* Number of columns in the result */

  131811.   u32 nData;         /* Slots used in azResult[].  (nRow+1)*nColumn */

  131812.   int rc;            /* Return code from sqlite3_exec() */

  131813. } TabResult;

  131814. 

  131815. /*

  131816. ** This routine is called once for each row in the result table.  Its job

  131817. ** is to fill in the TabResult structure appropriately, allocating new

  131818. ** memory as necessary.

  131819. */

  131820. static int sqlite3_get_table_cb(void *pArg, int nCol, char **argv, char **colv){

  131821.   TabResult *p = (TabResult*)pArg;  /* Result accumulator */

  131822.   int need;                         /* Slots needed in p->azResult[] */

  131823.   int i;                            /* Loop counter */

  131824.   char *z;                          /* A single column of result */

  131825. 

  131826.   /* Make sure there is enough space in p->azResult to hold everything

  131827.   ** we need to remember from this invocation of the callback.

  131828.   */

  131829.   if( p->nRow==0 && argv!=0 ){

  131830.     need = nCol*2;

  131831.   }else{

  131832.     need = nCol;

  131833.   }

  131834.   if( p->nData + need > p->nAlloc ){

  131835.     char **azNew;

  131836.     p->nAlloc = p->nAlloc*2 + need;

  131837.     azNew = sqlite3_realloc64( p->azResult, sizeof(char*)*p->nAlloc );

  131838.     if( azNew==0 ) goto malloc_failed;

  131839.     p->azResult = azNew;

  131840.   }

  131841. 

  131842.   /* If this is the first row, then generate an extra row containing

  131843.   ** the names of all columns.

  131844.   */

  131845.   if( p->nRow==0 ){

  131846.     p->nColumn = nCol;

  131847.     for(i=0; i<nCol; i++){

  131848.       z = sqlite3_mprintf("%s", colv[i]);

  131849.       if( z==0 ) goto malloc_failed;

  131850.       p->azResult[p->nData++] = z;

  131851.     }

  131852.   }else if( (int)p->nColumn!=nCol ){

  131853.     sqlite3_free(p->zErrMsg);

  131854.     p->zErrMsg = sqlite3_mprintf(

  131855.        "sqlite3_get_table() called with two or more incompatible queries"

  131856.     );

  131857.     p->rc = SQLITE_ERROR;

  131858.     return 1;

  131859.   }

  131860. 

  131861.   /* Copy over the row data

  131862.   */

  131863.   if( argv!=0 ){

  131864.     for(i=0; i<nCol; i++){

  131865.       if( argv[i]==0 ){

  131866.         z = 0;

  131867.       }else{

  131868.         int n = sqlite3Strlen30(argv[i])+1;

  131869.         z = sqlite3_malloc64( n );

  131870.         if( z==0 ) goto malloc_failed;

  131871.         memcpy(z, argv[i], n);

  131872.       }

  131873.       p->azResult[p->nData++] = z;

  131874.     }

  131875.     p->nRow++;

  131876.   }

  131877.   return 0;

  131878. 

  131879. malloc_failed:

  131880.   p->rc = SQLITE_NOMEM_BKPT;

  131881.   return 1;

  131882. }

  131883. 

  131884. /*

  131885. ** Query the database.  But instead of invoking a callback for each row,

  131886. ** malloc() for space to hold the result and return the entire results

  131887. ** at the conclusion of the call.

  131888. **

  131889. ** The result that is written to ***pazResult is held in memory obtained

  131890. ** from malloc().  But the caller cannot free this memory directly.  

  131891. ** Instead, the entire table should be passed to sqlite3_free_table() when

  131892. ** the calling procedure is finished using it.

  131893. */

  131894. SQLITE_API int sqlite3_get_table(

  131895.   sqlite3 *db,                /* The database on which the SQL executes */

  131896.   const char *zSql,           /* The SQL to be executed */

  131897.   char ***pazResult,          /* Write the result table here */

  131898.   int *pnRow,                 /* Write the number of rows in the result here */

  131899.   int *pnColumn,              /* Write the number of columns of result here */

  131900.   char **pzErrMsg             /* Write error messages here */

  131901. ){

  131902.   int rc;

  131903.   TabResult res;

  131904. 

  131905. #ifdef SQLITE_ENABLE_API_ARMOR

  131906.   if( !sqlite3SafetyCheckOk(db) || pazResult==0 ) return SQLITE_MISUSE_BKPT;

  131907. #endif

  131908.   *pazResult = 0;

  131909.   if( pnColumn ) *pnColumn = 0;

  131910.   if( pnRow ) *pnRow = 0;

  131911.   if( pzErrMsg ) *pzErrMsg = 0;

  131912.   res.zErrMsg = 0;

  131913.   res.nRow = 0;

  131914.   res.nColumn = 0;

  131915.   res.nData = 1;

  131916.   res.nAlloc = 20;

  131917.   res.rc = SQLITE_OK;

  131918.   res.azResult = sqlite3_malloc64(sizeof(char*)*res.nAlloc );

  131919.   if( res.azResult==0 ){

  131920.      db->errCode = SQLITE_NOMEM;

  131921.      return SQLITE_NOMEM_BKPT;

  131922.   }

  131923.   res.azResult[0] = 0;

  131924.   rc = sqlite3_exec(db, zSql, sqlite3_get_table_cb, &res, pzErrMsg);

  131925.   assert( sizeof(res.azResult[0])>= sizeof(res.nData) );

  131926.   res.azResult[0] = SQLITE_INT_TO_PTR(res.nData);

  131927.   if( (rc&0xff)==SQLITE_ABORT ){

  131928.     sqlite3_free_table(&res.azResult[1]);

  131929.     if( res.zErrMsg ){

  131930.       if( pzErrMsg ){

  131931.         sqlite3_free(*pzErrMsg);

  131932.         *pzErrMsg = sqlite3_mprintf("%s",res.zErrMsg);

  131933.       }

  131934.       sqlite3_free(res.zErrMsg);

  131935.     }

  131936.     db->errCode = res.rc;  /* Assume 32-bit assignment is atomic */

  131937.     return res.rc;

  131938.   }

  131939.   sqlite3_free(res.zErrMsg);

  131940.   if( rc!=SQLITE_OK ){

  131941.     sqlite3_free_table(&res.azResult[1]);

  131942.     return rc;

  131943.   }

  131944.   if( res.nAlloc>res.nData ){

  131945.     char **azNew;

  131946.     azNew = sqlite3_realloc64( res.azResult, sizeof(char*)*res.nData );

  131947.     if( azNew==0 ){

  131948.       sqlite3_free_table(&res.azResult[1]);

  131949.       db->errCode = SQLITE_NOMEM;

  131950.       return SQLITE_NOMEM_BKPT;

  131951.     }

  131952.     res.azResult = azNew;

  131953.   }

  131954.   *pazResult = &res.azResult[1];

  131955.   if( pnColumn ) *pnColumn = res.nColumn;

  131956.   if( pnRow ) *pnRow = res.nRow;

  131957.   return rc;

  131958. }

  131959. 

  131960. /*

  131961. ** This routine frees the space the sqlite3_get_table() malloced.

  131962. */

  131963. SQLITE_API void sqlite3_free_table(

  131964.   char **azResult            /* Result returned from sqlite3_get_table() */

  131965. ){

  131966.   if( azResult ){

  131967.     int i, n;

  131968.     azResult--;

  131969.     assert( azResult!=0 );

  131970.     n = SQLITE_PTR_TO_INT(azResult[0]);

  131971.     for(i=1; i<n; i++){ if( azResult[i] ) sqlite3_free(azResult[i]); }

  131972.     sqlite3_free(azResult);

  131973.   }

  131974. }

  131975. 

  131976. #endif /* SQLITE_OMIT_GET_TABLE */

  131977. 

  131978. /************** End of table.c ***********************************************/

  131979. /************** Begin file trigger.c *****************************************/

  131980. /*

  131981. **

  131982. ** The author disclaims copyright to this source code.  In place of

  131983. ** a legal notice, here is a blessing:

  131984. **

  131985. **    May you do good and not evil.

  131986. **    May you find forgiveness for yourself and forgive others.

  131987. **    May you share freely, never taking more than you give.

  131988. **

  131989. *************************************************************************

  131990. ** This file contains the implementation for TRIGGERs

  131991. */

  131992. /* #include "sqliteInt.h" */

  131993. 

  131994. #ifndef SQLITE_OMIT_TRIGGER

  131995. /*

  131996. ** Delete a linked list of TriggerStep structures.

  131997. */

  131998. SQLITE_PRIVATE void sqlite3DeleteTriggerStep(sqlite3 *db, TriggerStep *pTriggerStep){

  131999.   while( pTriggerStep ){

  132000.     TriggerStep * pTmp = pTriggerStep;

  132001.     pTriggerStep = pTriggerStep->pNext;

  132002. 

  132003.     sqlite3ExprDelete(db, pTmp->pWhere);

  132004.     sqlite3ExprListDelete(db, pTmp->pExprList);

  132005.     sqlite3SelectDelete(db, pTmp->pSelect);

  132006.     sqlite3IdListDelete(db, pTmp->pIdList);

  132007.     sqlite3UpsertDelete(db, pTmp->pUpsert);

  132008.     sqlite3DbFree(db, pTmp->zSpan);

  132009. 

  132010.     sqlite3DbFree(db, pTmp);

  132011.   }

  132012. }

  132013. 

  132014. /*

  132015. ** Given table pTab, return a list of all the triggers attached to 

  132016. ** the table. The list is connected by Trigger.pNext pointers.

  132017. **

  132018. ** All of the triggers on pTab that are in the same database as pTab

  132019. ** are already attached to pTab->pTrigger.  But there might be additional

  132020. ** triggers on pTab in the TEMP schema.  This routine prepends all

  132021. ** TEMP triggers on pTab to the beginning of the pTab->pTrigger list

  132022. ** and returns the combined list.

  132023. **

  132024. ** To state it another way:  This routine returns a list of all triggers

  132025. ** that fire off of pTab.  The list will include any TEMP triggers on

  132026. ** pTab as well as the triggers lised in pTab->pTrigger.

  132027. */

  132028. SQLITE_PRIVATE Trigger *sqlite3TriggerList(Parse *pParse, Table *pTab){

  132029.   Schema * const pTmpSchema = pParse->db->aDb[1].pSchema;

  132030.   Trigger *pList = 0;                  /* List of triggers to return */

  132031. 

  132032.   if( pParse->disableTriggers ){

  132033.     return 0;

  132034.   }

  132035. 

  132036.   if( pTmpSchema!=pTab->pSchema ){

  132037.     HashElem *p;

  132038.     assert( sqlite3SchemaMutexHeld(pParse->db, 0, pTmpSchema) );

  132039.     for(p=sqliteHashFirst(&pTmpSchema->trigHash); p; p=sqliteHashNext(p)){

  132040.       Trigger *pTrig = (Trigger *)sqliteHashData(p);

  132041.       if( pTrig->pTabSchema==pTab->pSchema

  132042.        && 0==sqlite3StrICmp(pTrig->table, pTab->zName) 

  132043.       ){

  132044.         pTrig->pNext = (pList ? pList : pTab->pTrigger);

  132045.         pList = pTrig;

  132046.       }

  132047.     }

  132048.   }

  132049. 

  132050.   return (pList ? pList : pTab->pTrigger);

  132051. }

  132052. 

  132053. /*

  132054. ** This is called by the parser when it sees a CREATE TRIGGER statement

  132055. ** up to the point of the BEGIN before the trigger actions.  A Trigger

  132056. ** structure is generated based on the information available and stored

  132057. ** in pParse->pNewTrigger.  After the trigger actions have been parsed, the

  132058. ** sqlite3FinishTrigger() function is called to complete the trigger

  132059. ** construction process.

  132060. */

  132061. SQLITE_PRIVATE void sqlite3BeginTrigger(

  132062.   Parse *pParse,      /* The parse context of the CREATE TRIGGER statement */

  132063.   Token *pName1,      /* The name of the trigger */

  132064.   Token *pName2,      /* The name of the trigger */

  132065.   int tr_tm,          /* One of TK_BEFORE, TK_AFTER, TK_INSTEAD */

  132066.   int op,             /* One of TK_INSERT, TK_UPDATE, TK_DELETE */

  132067.   IdList *pColumns,   /* column list if this is an UPDATE OF trigger */

  132068.   SrcList *pTableName,/* The name of the table/view the trigger applies to */

  132069.   Expr *pWhen,        /* WHEN clause */

  132070.   int isTemp,         /* True if the TEMPORARY keyword is present */

  132071.   int noErr           /* Suppress errors if the trigger already exists */

  132072. ){

  132073.   Trigger *pTrigger = 0;  /* The new trigger */

  132074.   Table *pTab;            /* Table that the trigger fires off of */

  132075.   char *zName = 0;        /* Name of the trigger */

  132076.   sqlite3 *db = pParse->db;  /* The database connection */

  132077.   int iDb;                /* The database to store the trigger in */

  132078.   Token *pName;           /* The unqualified db name */

  132079.   DbFixer sFix;           /* State vector for the DB fixer */

  132080. 

  132081.   assert( pName1!=0 );   /* pName1->z might be NULL, but not pName1 itself */

  132082.   assert( pName2!=0 );

  132083.   assert( op==TK_INSERT || op==TK_UPDATE || op==TK_DELETE );

  132084.   assert( op>0 && op<0xff );

  132085.   if( isTemp ){

  132086.     /* If TEMP was specified, then the trigger name may not be qualified. */

  132087.     if( pName2->n>0 ){

  132088.       sqlite3ErrorMsg(pParse, "temporary trigger may not have qualified name");

  132089.       goto trigger_cleanup;

  132090.     }

  132091.     iDb = 1;

  132092.     pName = pName1;

  132093.   }else{

  132094.     /* Figure out the db that the trigger will be created in */

  132095.     iDb = sqlite3TwoPartName(pParse, pName1, pName2, &pName);

  132096.     if( iDb<0 ){

  132097.       goto trigger_cleanup;

  132098.     }

  132099.   }

  132100.   if( !pTableName || db->mallocFailed ){

  132101.     goto trigger_cleanup;

  132102.   }

  132103. 

  132104.   /* A long-standing parser bug is that this syntax was allowed:

  132105.   **

  132106.   **    CREATE TRIGGER attached.demo AFTER INSERT ON attached.tab ....

  132107.   **                                                 ^^^^^^^^

  132108.   **

  132109.   ** To maintain backwards compatibility, ignore the database

  132110.   ** name on pTableName if we are reparsing out of SQLITE_MASTER.

  132111.   */

  132112.   if( db->init.busy && iDb!=1 ){

  132113.     sqlite3DbFree(db, pTableName->a[0].zDatabase);

  132114.     pTableName->a[0].zDatabase = 0;

  132115.   }

  132116. 

  132117.   /* If the trigger name was unqualified, and the table is a temp table,

  132118.   ** then set iDb to 1 to create the trigger in the temporary database.

  132119.   ** If sqlite3SrcListLookup() returns 0, indicating the table does not

  132120.   ** exist, the error is caught by the block below.

  132121.   */

  132122.   pTab = sqlite3SrcListLookup(pParse, pTableName);

  132123.   if( db->init.busy==0 && pName2->n==0 && pTab

  132124.         && pTab->pSchema==db->aDb[1].pSchema ){

  132125.     iDb = 1;

  132126.   }

  132127. 

  132128.   /* Ensure the table name matches database name and that the table exists */

  132129.   if( db->mallocFailed ) goto trigger_cleanup;

  132130.   assert( pTableName->nSrc==1 );

  132131.   sqlite3FixInit(&sFix, pParse, iDb, "trigger", pName);

  132132.   if( sqlite3FixSrcList(&sFix, pTableName) ){

  132133.     goto trigger_cleanup;

  132134.   }

  132135.   pTab = sqlite3SrcListLookup(pParse, pTableName);

  132136.   if( !pTab ){

  132137.     /* The table does not exist. */

  132138.     if( db->init.iDb==1 ){

  132139.       /* Ticket #3810.

  132140.       ** Normally, whenever a table is dropped, all associated triggers are

  132141.       ** dropped too.  But if a TEMP trigger is created on a non-TEMP table

  132142.       ** and the table is dropped by a different database connection, the

  132143.       ** trigger is not visible to the database connection that does the

  132144.       ** drop so the trigger cannot be dropped.  This results in an

  132145.       ** "orphaned trigger" - a trigger whose associated table is missing.

  132146.       */

  132147.       db->init.orphanTrigger = 1;

  132148.     }

  132149.     goto trigger_cleanup;

  132150.   }

  132151.   if( IsVirtual(pTab) ){

  132152.     sqlite3ErrorMsg(pParse, "cannot create triggers on virtual tables");

  132153.     goto trigger_cleanup;

  132154.   }

  132155. 

  132156.   /* Check that the trigger name is not reserved and that no trigger of the

  132157.   ** specified name exists */

  132158.   zName = sqlite3NameFromToken(db, pName);

  132159.   if( !zName || SQLITE_OK!=sqlite3CheckObjectName(pParse, zName) ){

  132160.     goto trigger_cleanup;

  132161.   }

  132162.   assert( sqlite3SchemaMutexHeld(db, iDb, 0) );

  132163.   if( !IN_RENAME_OBJECT ){

  132164.     if( sqlite3HashFind(&(db->aDb[iDb].pSchema->trigHash),zName) ){

  132165.       if( !noErr ){

  132166.         sqlite3ErrorMsg(pParse, "trigger %T already exists", pName);

  132167.       }else{

  132168.         assert( !db->init.busy );

  132169.         sqlite3CodeVerifySchema(pParse, iDb);

  132170.       }

  132171.       goto trigger_cleanup;

  132172.     }

  132173.   }

  132174. 

  132175.   /* Do not create a trigger on a system table */

  132176.   if( sqlite3StrNICmp(pTab->zName, "sqlite_", 7)==0 ){

  132177.     sqlite3ErrorMsg(pParse, "cannot create trigger on system table");

  132178.     goto trigger_cleanup;

  132179.   }

  132180. 

  132181.   /* INSTEAD of triggers are only for views and views only support INSTEAD

  132182.   ** of triggers.

  132183.   */

  132184.   if( pTab->pSelect && tr_tm!=TK_INSTEAD ){

  132185.     sqlite3ErrorMsg(pParse, "cannot create %s trigger on view: %S", 

  132186.         (tr_tm == TK_BEFORE)?"BEFORE":"AFTER", pTableName, 0);

  132187.     goto trigger_cleanup;

  132188.   }

  132189.   if( !pTab->pSelect && tr_tm==TK_INSTEAD ){

  132190.     sqlite3ErrorMsg(pParse, "cannot create INSTEAD OF"

  132191.         " trigger on table: %S", pTableName, 0);

  132192.     goto trigger_cleanup;

  132193.   }

  132194. 

  132195. #ifndef SQLITE_OMIT_AUTHORIZATION

  132196.   if( !IN_RENAME_OBJECT ){

  132197.     int iTabDb = sqlite3SchemaToIndex(db, pTab->pSchema);

  132198.     int code = SQLITE_CREATE_TRIGGER;

  132199.     const char *zDb = db->aDb[iTabDb].zDbSName;

  132200.     const char *zDbTrig = isTemp ? db->aDb[1].zDbSName : zDb;

  132201.     if( iTabDb==1 || isTemp ) code = SQLITE_CREATE_TEMP_TRIGGER;

  132202.     if( sqlite3AuthCheck(pParse, code, zName, pTab->zName, zDbTrig) ){

  132203.       goto trigger_cleanup;

  132204.     }

  132205.     if( sqlite3AuthCheck(pParse, SQLITE_INSERT, SCHEMA_TABLE(iTabDb),0,zDb)){

  132206.       goto trigger_cleanup;

  132207.     }

  132208.   }

  132209. #endif

  132210. 

  132211.   /* INSTEAD OF triggers can only appear on views and BEFORE triggers

  132212.   ** cannot appear on views.  So we might as well translate every

  132213.   ** INSTEAD OF trigger into a BEFORE trigger.  It simplifies code

  132214.   ** elsewhere.

  132215.   */

  132216.   if (tr_tm == TK_INSTEAD){

  132217.     tr_tm = TK_BEFORE;

  132218.   }

  132219. 

  132220.   /* Build the Trigger object */

  132221.   pTrigger = (Trigger*)sqlite3DbMallocZero(db, sizeof(Trigger));

  132222.   if( pTrigger==0 ) goto trigger_cleanup;

  132223.   pTrigger->zName = zName;

  132224.   zName = 0;

  132225.   pTrigger->table = sqlite3DbStrDup(db, pTableName->a[0].zName);

  132226.   pTrigger->pSchema = db->aDb[iDb].pSchema;

  132227.   pTrigger->pTabSchema = pTab->pSchema;

  132228.   pTrigger->op = (u8)op;

  132229.   pTrigger->tr_tm = tr_tm==TK_BEFORE ? TRIGGER_BEFORE : TRIGGER_AFTER;

  132230.   if( IN_RENAME_OBJECT ){

  132231.     sqlite3RenameTokenRemap(pParse, pTrigger->table, pTableName->a[0].zName);

  132232.     pTrigger->pWhen = pWhen;

  132233.     pWhen = 0;

  132234.   }else{

  132235.     pTrigger->pWhen = sqlite3ExprDup(db, pWhen, EXPRDUP_REDUCE);

  132236.   }

  132237.   pTrigger->pColumns = pColumns;

  132238.   pColumns = 0;

  132239.   assert( pParse->pNewTrigger==0 );

  132240.   pParse->pNewTrigger = pTrigger;

  132241. 

  132242. trigger_cleanup:

  132243.   sqlite3DbFree(db, zName);

  132244.   sqlite3SrcListDelete(db, pTableName);

  132245.   sqlite3IdListDelete(db, pColumns);

  132246.   sqlite3ExprDelete(db, pWhen);

  132247.   if( !pParse->pNewTrigger ){

  132248.     sqlite3DeleteTrigger(db, pTrigger);

  132249.   }else{

  132250.     assert( pParse->pNewTrigger==pTrigger );

  132251.   }

  132252. }

  132253. 

  132254. /*

  132255. ** This routine is called after all of the trigger actions have been parsed

  132256. ** in order to complete the process of building the trigger.

  132257. */

  132258. SQLITE_PRIVATE void sqlite3FinishTrigger(

  132259.   Parse *pParse,          /* Parser context */

  132260.   TriggerStep *pStepList, /* The triggered program */

  132261.   Token *pAll             /* Token that describes the complete CREATE TRIGGER */

  132262. ){

  132263.   Trigger *pTrig = pParse->pNewTrigger;   /* Trigger being finished */

  132264.   char *zName;                            /* Name of trigger */

  132265.   sqlite3 *db = pParse->db;               /* The database */

  132266.   DbFixer sFix;                           /* Fixer object */

  132267.   int iDb;                                /* Database containing the trigger */

  132268.   Token nameToken;                        /* Trigger name for error reporting */

  132269. 

  132270.   pParse->pNewTrigger = 0;

  132271.   if( NEVER(pParse->nErr) || !pTrig ) goto triggerfinish_cleanup;

  132272.   zName = pTrig->zName;

  132273.   iDb = sqlite3SchemaToIndex(pParse->db, pTrig->pSchema);

  132274.   pTrig->step_list = pStepList;

  132275.   while( pStepList ){

  132276.     pStepList->pTrig = pTrig;

  132277.     pStepList = pStepList->pNext;

  132278.   }

  132279.   sqlite3TokenInit(&nameToken, pTrig->zName);

  132280.   sqlite3FixInit(&sFix, pParse, iDb, "trigger", &nameToken);

  132281.   if( sqlite3FixTriggerStep(&sFix, pTrig->step_list) 

  132282.    || sqlite3FixExpr(&sFix, pTrig->pWhen) 

  132283.   ){

  132284.     goto triggerfinish_cleanup;

  132285.   }

  132286. 

  132287. #ifndef SQLITE_OMIT_ALTERTABLE

  132288.   if( IN_RENAME_OBJECT ){

  132289.     assert( !db->init.busy );

  132290.     pParse->pNewTrigger = pTrig;

  132291.     pTrig = 0;

  132292.   }else

  132293. #endif

  132294. 

  132295.   /* if we are not initializing,

  132296.   ** build the sqlite_master entry

  132297.   */

  132298.   if( !db->init.busy ){

  132299.     Vdbe *v;

  132300.     char *z;

  132301. 

  132302.     /* Make an entry in the sqlite_master table */

  132303.     v = sqlite3GetVdbe(pParse);

  132304.     if( v==0 ) goto triggerfinish_cleanup;

  132305.     sqlite3BeginWriteOperation(pParse, 0, iDb);

  132306.     z = sqlite3DbStrNDup(db, (char*)pAll->z, pAll->n);

  132307.     testcase( z==0 );

  132308.     sqlite3NestedParse(pParse,

  132309.        "INSERT INTO %Q.%s VALUES('trigger',%Q,%Q,0,'CREATE TRIGGER %q')",

  132310.        db->aDb[iDb].zDbSName, MASTER_NAME, zName,

  132311.        pTrig->table, z);

  132312.     sqlite3DbFree(db, z);

  132313.     sqlite3ChangeCookie(pParse, iDb);

  132314.     sqlite3VdbeAddParseSchemaOp(v, iDb,

  132315.         sqlite3MPrintf(db, "type='trigger' AND name='%q'", zName));

  132316.   }

  132317. 

  132318.   if( db->init.busy ){

  132319.     Trigger *pLink = pTrig;

  132320.     Hash *pHash = &db->aDb[iDb].pSchema->trigHash;

  132321.     assert( sqlite3SchemaMutexHeld(db, iDb, 0) );

  132322.     pTrig = sqlite3HashInsert(pHash, zName, pTrig);

  132323.     if( pTrig ){

  132324.       sqlite3OomFault(db);

  132325.     }else if( pLink->pSchema==pLink->pTabSchema ){

  132326.       Table *pTab;

  132327.       pTab = sqlite3HashFind(&pLink->pTabSchema->tblHash, pLink->table);

  132328.       assert( pTab!=0 );

  132329.       pLink->pNext = pTab->pTrigger;

  132330.       pTab->pTrigger = pLink;

  132331.     }

  132332.   }

  132333. 

  132334. triggerfinish_cleanup:

  132335.   sqlite3DeleteTrigger(db, pTrig);

  132336.   assert( IN_RENAME_OBJECT || !pParse->pNewTrigger );

  132337.   sqlite3DeleteTriggerStep(db, pStepList);

  132338. }

  132339. 

  132340. /*

  132341. ** Duplicate a range of text from an SQL statement, then convert all

  132342. ** whitespace characters into ordinary space characters.

  132343. */

  132344. static char *triggerSpanDup(sqlite3 *db, const char *zStart, const char *zEnd){

  132345.   char *z = sqlite3DbSpanDup(db, zStart, zEnd);

  132346.   int i;

  132347.   if( z ) for(i=0; z[i]; i++) if( sqlite3Isspace(z[i]) ) z[i] = ' ';

  132348.   return z;

  132349. }    

  132350. 

  132351. /*

  132352. ** Turn a SELECT statement (that the pSelect parameter points to) into

  132353. ** a trigger step.  Return a pointer to a TriggerStep structure.

  132354. **

  132355. ** The parser calls this routine when it finds a SELECT statement in

  132356. ** body of a TRIGGER.  

  132357. */

  132358. SQLITE_PRIVATE TriggerStep *sqlite3TriggerSelectStep(

  132359.   sqlite3 *db,                /* Database connection */

  132360.   Select *pSelect,            /* The SELECT statement */

  132361.   const char *zStart,         /* Start of SQL text */

  132362.   const char *zEnd            /* End of SQL text */

  132363. ){

  132364.   TriggerStep *pTriggerStep = sqlite3DbMallocZero(db, sizeof(TriggerStep));

  132365.   if( pTriggerStep==0 ) {

  132366.     sqlite3SelectDelete(db, pSelect);

  132367.     return 0;

  132368.   }

  132369.   pTriggerStep->op = TK_SELECT;

  132370.   pTriggerStep->pSelect = pSelect;

  132371.   pTriggerStep->orconf = OE_Default;

  132372.   pTriggerStep->zSpan = triggerSpanDup(db, zStart, zEnd);

  132373.   return pTriggerStep;

  132374. }

  132375. 

  132376. /*

  132377. ** Allocate space to hold a new trigger step.  The allocated space

  132378. ** holds both the TriggerStep object and the TriggerStep.target.z string.

  132379. **

  132380. ** If an OOM error occurs, NULL is returned and db->mallocFailed is set.

  132381. */

  132382. static TriggerStep *triggerStepAllocate(

  132383.   Parse *pParse,              /* Parser context */

  132384.   u8 op,                      /* Trigger opcode */

  132385.   Token *pName,               /* The target name */

  132386.   const char *zStart,         /* Start of SQL text */

  132387.   const char *zEnd            /* End of SQL text */

  132388. ){

  132389.   sqlite3 *db = pParse->db;

  132390.   TriggerStep *pTriggerStep;

  132391. 

  132392.   pTriggerStep = sqlite3DbMallocZero(db, sizeof(TriggerStep) + pName->n + 1);

  132393.   if( pTriggerStep ){

  132394.     char *z = (char*)&pTriggerStep[1];

  132395.     memcpy(z, pName->z, pName->n);

  132396.     sqlite3Dequote(z);

  132397.     pTriggerStep->zTarget = z;

  132398.     pTriggerStep->op = op;

  132399.     pTriggerStep->zSpan = triggerSpanDup(db, zStart, zEnd);

  132400.     if( IN_RENAME_OBJECT ){

  132401.       sqlite3RenameTokenMap(pParse, pTriggerStep->zTarget, pName);

  132402.     }

  132403.   }

  132404.   return pTriggerStep;

  132405. }

  132406. 

  132407. /*

  132408. ** Build a trigger step out of an INSERT statement.  Return a pointer

  132409. ** to the new trigger step.

  132410. **

  132411. ** The parser calls this routine when it sees an INSERT inside the

  132412. ** body of a trigger.

  132413. */

  132414. SQLITE_PRIVATE TriggerStep *sqlite3TriggerInsertStep(

  132415.   Parse *pParse,      /* Parser */

  132416.   Token *pTableName,  /* Name of the table into which we insert */

  132417.   IdList *pColumn,    /* List of columns in pTableName to insert into */

  132418.   Select *pSelect,    /* A SELECT statement that supplies values */

  132419.   u8 orconf,          /* The conflict algorithm (OE_Abort, OE_Replace, etc.) */

  132420.   Upsert *pUpsert,    /* ON CONFLICT clauses for upsert */

  132421.   const char *zStart, /* Start of SQL text */

  132422.   const char *zEnd    /* End of SQL text */

  132423. ){

  132424.   sqlite3 *db = pParse->db;

  132425.   TriggerStep *pTriggerStep;

  132426. 

  132427.   assert(pSelect != 0 || db->mallocFailed);

  132428. 

  132429.   pTriggerStep = triggerStepAllocate(pParse, TK_INSERT, pTableName,zStart,zEnd);

  132430.   if( pTriggerStep ){

  132431.     if( IN_RENAME_OBJECT ){

  132432.       pTriggerStep->pSelect = pSelect;

  132433.       pSelect = 0;

  132434.     }else{

  132435.       pTriggerStep->pSelect = sqlite3SelectDup(db, pSelect, EXPRDUP_REDUCE);

  132436.     }

  132437.     pTriggerStep->pIdList = pColumn;

  132438.     pTriggerStep->pUpsert = pUpsert;

  132439.     pTriggerStep->orconf = orconf;

  132440.   }else{

  132441.     testcase( pColumn );

  132442.     sqlite3IdListDelete(db, pColumn);

  132443.     testcase( pUpsert );

  132444.     sqlite3UpsertDelete(db, pUpsert);

  132445.   }

  132446.   sqlite3SelectDelete(db, pSelect);

  132447. 

  132448.   return pTriggerStep;

  132449. }

  132450. 

  132451. /*

  132452. ** Construct a trigger step that implements an UPDATE statement and return

  132453. ** a pointer to that trigger step.  The parser calls this routine when it

  132454. ** sees an UPDATE statement inside the body of a CREATE TRIGGER.

  132455. */

  132456. SQLITE_PRIVATE TriggerStep *sqlite3TriggerUpdateStep(

  132457.   Parse *pParse,          /* Parser */

  132458.   Token *pTableName,   /* Name of the table to be updated */

  132459.   ExprList *pEList,    /* The SET clause: list of column and new values */

  132460.   Expr *pWhere,        /* The WHERE clause */

  132461.   u8 orconf,           /* The conflict algorithm. (OE_Abort, OE_Ignore, etc) */

  132462.   const char *zStart,  /* Start of SQL text */

  132463.   const char *zEnd     /* End of SQL text */

  132464. ){

  132465.   sqlite3 *db = pParse->db;

  132466.   TriggerStep *pTriggerStep;

  132467. 

  132468.   pTriggerStep = triggerStepAllocate(pParse, TK_UPDATE, pTableName,zStart,zEnd);

  132469.   if( pTriggerStep ){

  132470.     if( IN_RENAME_OBJECT ){

  132471.       pTriggerStep->pExprList = pEList;

  132472.       pTriggerStep->pWhere = pWhere;

  132473.       pEList = 0;

  132474.       pWhere = 0;

  132475.     }else{

  132476.       pTriggerStep->pExprList = sqlite3ExprListDup(db, pEList, EXPRDUP_REDUCE);

  132477.       pTriggerStep->pWhere = sqlite3ExprDup(db, pWhere, EXPRDUP_REDUCE);

  132478.     }

  132479.     pTriggerStep->orconf = orconf;

  132480.   }

  132481.   sqlite3ExprListDelete(db, pEList);

  132482.   sqlite3ExprDelete(db, pWhere);

  132483.   return pTriggerStep;

  132484. }

  132485. 

  132486. /*

  132487. ** Construct a trigger step that implements a DELETE statement and return

  132488. ** a pointer to that trigger step.  The parser calls this routine when it

  132489. ** sees a DELETE statement inside the body of a CREATE TRIGGER.

  132490. */

  132491. SQLITE_PRIVATE TriggerStep *sqlite3TriggerDeleteStep(

  132492.   Parse *pParse,          /* Parser */

  132493.   Token *pTableName,      /* The table from which rows are deleted */

  132494.   Expr *pWhere,           /* The WHERE clause */

  132495.   const char *zStart,     /* Start of SQL text */

  132496.   const char *zEnd        /* End of SQL text */

  132497. ){

  132498.   sqlite3 *db = pParse->db;

  132499.   TriggerStep *pTriggerStep;

  132500. 

  132501.   pTriggerStep = triggerStepAllocate(pParse, TK_DELETE, pTableName,zStart,zEnd);

  132502.   if( pTriggerStep ){

  132503.     if( IN_RENAME_OBJECT ){

  132504.       pTriggerStep->pWhere = pWhere;

  132505.       pWhere = 0;

  132506.     }else{

  132507.       pTriggerStep->pWhere = sqlite3ExprDup(db, pWhere, EXPRDUP_REDUCE);

  132508.     }

  132509.     pTriggerStep->orconf = OE_Default;

  132510.   }

  132511.   sqlite3ExprDelete(db, pWhere);

  132512.   return pTriggerStep;

  132513. }

  132514. 

  132515. /* 

  132516. ** Recursively delete a Trigger structure

  132517. */

  132518. SQLITE_PRIVATE void sqlite3DeleteTrigger(sqlite3 *db, Trigger *pTrigger){

  132519.   if( pTrigger==0 ) return;

  132520.   sqlite3DeleteTriggerStep(db, pTrigger->step_list);

  132521.   sqlite3DbFree(db, pTrigger->zName);

  132522.   sqlite3DbFree(db, pTrigger->table);

  132523.   sqlite3ExprDelete(db, pTrigger->pWhen);

  132524.   sqlite3IdListDelete(db, pTrigger->pColumns);

  132525.   sqlite3DbFree(db, pTrigger);

  132526. }

  132527. 

  132528. /*

  132529. ** This function is called to drop a trigger from the database schema. 

  132530. **

  132531. ** This may be called directly from the parser and therefore identifies

  132532. ** the trigger by name.  The sqlite3DropTriggerPtr() routine does the

  132533. ** same job as this routine except it takes a pointer to the trigger

  132534. ** instead of the trigger name.

  132535. **/

  132536. SQLITE_PRIVATE void sqlite3DropTrigger(Parse *pParse, SrcList *pName, int noErr){

  132537.   Trigger *pTrigger = 0;

  132538.   int i;

  132539.   const char *zDb;

  132540.   const char *zName;

  132541.   sqlite3 *db = pParse->db;

  132542. 

  132543.   if( db->mallocFailed ) goto drop_trigger_cleanup;

  132544.   if( SQLITE_OK!=sqlite3ReadSchema(pParse) ){

  132545.     goto drop_trigger_cleanup;

  132546.   }

  132547. 

  132548.   assert( pName->nSrc==1 );

  132549.   zDb = pName->a[0].zDatabase;

  132550.   zName = pName->a[0].zName;

  132551.   assert( zDb!=0 || sqlite3BtreeHoldsAllMutexes(db) );

  132552.   for(i=OMIT_TEMPDB; i<db->nDb; i++){

  132553.     int j = (i<2) ? i^1 : i;  /* Search TEMP before MAIN */

  132554.     if( zDb && sqlite3StrICmp(db->aDb[j].zDbSName, zDb) ) continue;

  132555.     assert( sqlite3SchemaMutexHeld(db, j, 0) );

  132556.     pTrigger = sqlite3HashFind(&(db->aDb[j].pSchema->trigHash), zName);

  132557.     if( pTrigger ) break;

  132558.   }

  132559.   if( !pTrigger ){

  132560.     if( !noErr ){

  132561.       sqlite3ErrorMsg(pParse, "no such trigger: %S", pName, 0);

  132562.     }else{

  132563.       sqlite3CodeVerifyNamedSchema(pParse, zDb);

  132564.     }

  132565.     pParse->checkSchema = 1;

  132566.     goto drop_trigger_cleanup;

  132567.   }

  132568.   sqlite3DropTriggerPtr(pParse, pTrigger);

  132569. 

  132570. drop_trigger_cleanup:

  132571.   sqlite3SrcListDelete(db, pName);

  132572. }

  132573. 

  132574. /*

  132575. ** Return a pointer to the Table structure for the table that a trigger

  132576. ** is set on.

  132577. */

  132578. static Table *tableOfTrigger(Trigger *pTrigger){

  132579.   return sqlite3HashFind(&pTrigger->pTabSchema->tblHash, pTrigger->table);

  132580. }

  132581. 

  132582. 

  132583. /*

  132584. ** Drop a trigger given a pointer to that trigger. 

  132585. */

  132586. SQLITE_PRIVATE void sqlite3DropTriggerPtr(Parse *pParse, Trigger *pTrigger){

  132587.   Table   *pTable;

  132588.   Vdbe *v;

  132589.   sqlite3 *db = pParse->db;

  132590.   int iDb;

  132591. 

  132592.   iDb = sqlite3SchemaToIndex(pParse->db, pTrigger->pSchema);

  132593.   assert( iDb>=0 && iDb<db->nDb );

  132594.   pTable = tableOfTrigger(pTrigger);

  132595.   assert( pTable );

  132596.   assert( pTable->pSchema==pTrigger->pSchema || iDb==1 );

  132597. #ifndef SQLITE_OMIT_AUTHORIZATION

  132598.   {

  132599.     int code = SQLITE_DROP_TRIGGER;

  132600.     const char *zDb = db->aDb[iDb].zDbSName;

  132601.     const char *zTab = SCHEMA_TABLE(iDb);

  132602.     if( iDb==1 ) code = SQLITE_DROP_TEMP_TRIGGER;

  132603.     if( sqlite3AuthCheck(pParse, code, pTrigger->zName, pTable->zName, zDb) ||

  132604.       sqlite3AuthCheck(pParse, SQLITE_DELETE, zTab, 0, zDb) ){

  132605.       return;

  132606.     }

  132607.   }

  132608. #endif

  132609. 

  132610.   /* Generate code to destroy the database record of the trigger.

  132611.   */

  132612.   assert( pTable!=0 );

  132613.   if( (v = sqlite3GetVdbe(pParse))!=0 ){

  132614.     sqlite3NestedParse(pParse,

  132615.        "DELETE FROM %Q.%s WHERE name=%Q AND type='trigger'",

  132616.        db->aDb[iDb].zDbSName, MASTER_NAME, pTrigger->zName

  132617.     );

  132618.     sqlite3ChangeCookie(pParse, iDb);

  132619.     sqlite3VdbeAddOp4(v, OP_DropTrigger, iDb, 0, 0, pTrigger->zName, 0);

  132620.   }

  132621. }

  132622. 

  132623. /*

  132624. ** Remove a trigger from the hash tables of the sqlite* pointer.

  132625. */

  132626. SQLITE_PRIVATE void sqlite3UnlinkAndDeleteTrigger(sqlite3 *db, int iDb, const char *zName){

  132627.   Trigger *pTrigger;

  132628.   Hash *pHash;

  132629. 

  132630.   assert( sqlite3SchemaMutexHeld(db, iDb, 0) );

  132631.   pHash = &(db->aDb[iDb].pSchema->trigHash);

  132632.   pTrigger = sqlite3HashInsert(pHash, zName, 0);

  132633.   if( ALWAYS(pTrigger) ){

  132634.     if( pTrigger->pSchema==pTrigger->pTabSchema ){

  132635.       Table *pTab = tableOfTrigger(pTrigger);

  132636.       Trigger **pp;

  132637.       for(pp=&pTab->pTrigger; *pp!=pTrigger; pp=&((*pp)->pNext));

  132638.       *pp = (*pp)->pNext;

  132639.     }

  132640.     sqlite3DeleteTrigger(db, pTrigger);

  132641.     db->mDbFlags |= DBFLAG_SchemaChange;

  132642.   }

  132643. }

  132644. 

  132645. /*

  132646. ** pEList is the SET clause of an UPDATE statement.  Each entry

  132647. ** in pEList is of the format <id>=<expr>.  If any of the entries

  132648. ** in pEList have an <id> which matches an identifier in pIdList,

  132649. ** then return TRUE.  If pIdList==NULL, then it is considered a

  132650. ** wildcard that matches anything.  Likewise if pEList==NULL then

  132651. ** it matches anything so always return true.  Return false only

  132652. ** if there is no match.

  132653. */

  132654. static int checkColumnOverlap(IdList *pIdList, ExprList *pEList){

  132655.   int e;

  132656.   if( pIdList==0 || NEVER(pEList==0) ) return 1;

  132657.   for(e=0; e<pEList->nExpr; e++){

  132658.     if( sqlite3IdListIndex(pIdList, pEList->a[e].zName)>=0 ) return 1;

  132659.   }

  132660.   return 0; 

  132661. }

  132662. 

  132663. /*

  132664. ** Return a list of all triggers on table pTab if there exists at least

  132665. ** one trigger that must be fired when an operation of type 'op' is 

  132666. ** performed on the table, and, if that operation is an UPDATE, if at

  132667. ** least one of the columns in pChanges is being modified.

  132668. */

  132669. SQLITE_PRIVATE Trigger *sqlite3TriggersExist(

  132670.   Parse *pParse,          /* Parse context */

  132671.   Table *pTab,            /* The table the contains the triggers */

  132672.   int op,                 /* one of TK_DELETE, TK_INSERT, TK_UPDATE */

  132673.   ExprList *pChanges,     /* Columns that change in an UPDATE statement */

  132674.   int *pMask              /* OUT: Mask of TRIGGER_BEFORE|TRIGGER_AFTER */

  132675. ){

  132676.   int mask = 0;

  132677.   Trigger *pList = 0;

  132678.   Trigger *p;

  132679. 

  132680.   if( (pParse->db->flags & SQLITE_EnableTrigger)!=0 ){

  132681.     pList = sqlite3TriggerList(pParse, pTab);

  132682.   }

  132683.   assert( pList==0 || IsVirtual(pTab)==0 );

  132684.   for(p=pList; p; p=p->pNext){

  132685.     if( p->op==op && checkColumnOverlap(p->pColumns, pChanges) ){

  132686.       mask |= p->tr_tm;

  132687.     }

  132688.   }

  132689.   if( pMask ){

  132690.     *pMask = mask;

  132691.   }

  132692.   return (mask ? pList : 0);

  132693. }

  132694. 

  132695. /*

  132696. ** Convert the pStep->zTarget string into a SrcList and return a pointer

  132697. ** to that SrcList.

  132698. **

  132699. ** This routine adds a specific database name, if needed, to the target when

  132700. ** forming the SrcList.  This prevents a trigger in one database from

  132701. ** referring to a target in another database.  An exception is when the

  132702. ** trigger is in TEMP in which case it can refer to any other database it

  132703. ** wants.

  132704. */

  132705. static SrcList *targetSrcList(

  132706.   Parse *pParse,       /* The parsing context */

  132707.   TriggerStep *pStep   /* The trigger containing the target token */

  132708. ){

  132709.   sqlite3 *db = pParse->db;

  132710.   int iDb;             /* Index of the database to use */

  132711.   SrcList *pSrc;       /* SrcList to be returned */

  132712. 

  132713.   pSrc = sqlite3SrcListAppend(pParse, 0, 0, 0);

  132714.   if( pSrc ){

  132715.     assert( pSrc->nSrc>0 );

  132716.     pSrc->a[pSrc->nSrc-1].zName = sqlite3DbStrDup(db, pStep->zTarget);

  132717.     iDb = sqlite3SchemaToIndex(db, pStep->pTrig->pSchema);

  132718.     if( iDb==0 || iDb>=2 ){

  132719.       const char *zDb;

  132720.       assert( iDb<db->nDb );

  132721.       zDb = db->aDb[iDb].zDbSName;

  132722.       pSrc->a[pSrc->nSrc-1].zDatabase =  sqlite3DbStrDup(db, zDb);

  132723.     }

  132724.   }

  132725.   return pSrc;

  132726. }

  132727. 

  132728. /*

  132729. ** Generate VDBE code for the statements inside the body of a single 

  132730. ** trigger.

  132731. */

  132732. static int codeTriggerProgram(

  132733.   Parse *pParse,            /* The parser context */

  132734.   TriggerStep *pStepList,   /* List of statements inside the trigger body */

  132735.   int orconf                /* Conflict algorithm. (OE_Abort, etc) */  

  132736. ){

  132737.   TriggerStep *pStep;

  132738.   Vdbe *v = pParse->pVdbe;

  132739.   sqlite3 *db = pParse->db;

  132740. 

  132741.   assert( pParse->pTriggerTab && pParse->pToplevel );

  132742.   assert( pStepList );

  132743.   assert( v!=0 );

  132744.   for(pStep=pStepList; pStep; pStep=pStep->pNext){

  132745.     /* Figure out the ON CONFLICT policy that will be used for this step

  132746.     ** of the trigger program. If the statement that caused this trigger

  132747.     ** to fire had an explicit ON CONFLICT, then use it. Otherwise, use

  132748.     ** the ON CONFLICT policy that was specified as part of the trigger

  132749.     ** step statement. Example:

  132750.     **

  132751.     **   CREATE TRIGGER AFTER INSERT ON t1 BEGIN;

  132752.     **     INSERT OR REPLACE INTO t2 VALUES(new.a, new.b);

  132753.     **   END;

  132754.     **

  132755.     **   INSERT INTO t1 ... ;            -- insert into t2 uses REPLACE policy

  132756.     **   INSERT OR IGNORE INTO t1 ... ;  -- insert into t2 uses IGNORE policy

  132757.     */

  132758.     pParse->eOrconf = (orconf==OE_Default)?pStep->orconf:(u8)orconf;

  132759.     assert( pParse->okConstFactor==0 );

  132760. 

  132761. #ifndef SQLITE_OMIT_TRACE

  132762.     if( pStep->zSpan ){

  132763.       sqlite3VdbeAddOp4(v, OP_Trace, 0x7fffffff, 1, 0,

  132764.                         sqlite3MPrintf(db, "-- %s", pStep->zSpan),

  132765.                         P4_DYNAMIC);

  132766.     }

  132767. #endif

  132768. 

  132769.     switch( pStep->op ){

  132770.       case TK_UPDATE: {

  132771.         sqlite3Update(pParse, 

  132772.           targetSrcList(pParse, pStep),

  132773.           sqlite3ExprListDup(db, pStep->pExprList, 0), 

  132774.           sqlite3ExprDup(db, pStep->pWhere, 0), 

  132775.           pParse->eOrconf, 0, 0, 0

  132776.         );

  132777.         break;

  132778.       }

  132779.       case TK_INSERT: {

  132780.         sqlite3Insert(pParse, 

  132781.           targetSrcList(pParse, pStep),

  132782.           sqlite3SelectDup(db, pStep->pSelect, 0), 

  132783.           sqlite3IdListDup(db, pStep->pIdList), 

  132784.           pParse->eOrconf,

  132785.           sqlite3UpsertDup(db, pStep->pUpsert)

  132786.         );

  132787.         break;

  132788.       }

  132789.       case TK_DELETE: {

  132790.         sqlite3DeleteFrom(pParse, 

  132791.           targetSrcList(pParse, pStep),

  132792.           sqlite3ExprDup(db, pStep->pWhere, 0), 0, 0

  132793.         );

  132794.         break;

  132795.       }

  132796.       default: assert( pStep->op==TK_SELECT ); {

  132797.         SelectDest sDest;

  132798.         Select *pSelect = sqlite3SelectDup(db, pStep->pSelect, 0);

  132799.         sqlite3SelectDestInit(&sDest, SRT_Discard, 0);

  132800.         sqlite3Select(pParse, pSelect, &sDest);

  132801.         sqlite3SelectDelete(db, pSelect);

  132802.         break;

  132803.       }

  132804.     } 

  132805.     if( pStep->op!=TK_SELECT ){

  132806.       sqlite3VdbeAddOp0(v, OP_ResetCount);

  132807.     }

  132808.   }

  132809. 

  132810.   return 0;

  132811. }

  132812. 

  132813. #ifdef SQLITE_ENABLE_EXPLAIN_COMMENTS

  132814. /*

  132815. ** This function is used to add VdbeComment() annotations to a VDBE

  132816. ** program. It is not used in production code, only for debugging.

  132817. */

  132818. static const char *onErrorText(int onError){

  132819.   switch( onError ){

  132820.     case OE_Abort:    return "abort";

  132821.     case OE_Rollback: return "rollback";

  132822.     case OE_Fail:     return "fail";

  132823.     case OE_Replace:  return "replace";

  132824.     case OE_Ignore:   return "ignore";

  132825.     case OE_Default:  return "default";

  132826.   }

  132827.   return "n/a";

  132828. }

  132829. #endif

  132830. 

  132831. /*

  132832. ** Parse context structure pFrom has just been used to create a sub-vdbe

  132833. ** (trigger program). If an error has occurred, transfer error information

  132834. ** from pFrom to pTo.

  132835. */

  132836. static void transferParseError(Parse *pTo, Parse *pFrom){

  132837.   assert( pFrom->zErrMsg==0 || pFrom->nErr );

  132838.   assert( pTo->zErrMsg==0 || pTo->nErr );

  132839.   if( pTo->nErr==0 ){

  132840.     pTo->zErrMsg = pFrom->zErrMsg;

  132841.     pTo->nErr = pFrom->nErr;

  132842.     pTo->rc = pFrom->rc;

  132843.   }else{

  132844.     sqlite3DbFree(pFrom->db, pFrom->zErrMsg);

  132845.   }

  132846. }

  132847. 

  132848. /*

  132849. ** Create and populate a new TriggerPrg object with a sub-program 

  132850. ** implementing trigger pTrigger with ON CONFLICT policy orconf.

  132851. */

  132852. static TriggerPrg *codeRowTrigger(

  132853.   Parse *pParse,       /* Current parse context */

  132854.   Trigger *pTrigger,   /* Trigger to code */

  132855.   Table *pTab,         /* The table pTrigger is attached to */

  132856.   int orconf           /* ON CONFLICT policy to code trigger program with */

  132857. ){

  132858.   Parse *pTop = sqlite3ParseToplevel(pParse);

  132859.   sqlite3 *db = pParse->db;   /* Database handle */

  132860.   TriggerPrg *pPrg;           /* Value to return */

  132861.   Expr *pWhen = 0;            /* Duplicate of trigger WHEN expression */

  132862.   Vdbe *v;                    /* Temporary VM */

  132863.   NameContext sNC;            /* Name context for sub-vdbe */

  132864.   SubProgram *pProgram = 0;   /* Sub-vdbe for trigger program */

  132865.   Parse *pSubParse;           /* Parse context for sub-vdbe */

  132866.   int iEndTrigger = 0;        /* Label to jump to if WHEN is false */

  132867. 

  132868.   assert( pTrigger->zName==0 || pTab==tableOfTrigger(pTrigger) );

  132869.   assert( pTop->pVdbe );

  132870. 

  132871.   /* Allocate the TriggerPrg and SubProgram objects. To ensure that they

  132872.   ** are freed if an error occurs, link them into the Parse.pTriggerPrg 

  132873.   ** list of the top-level Parse object sooner rather than later.  */

  132874.   pPrg = sqlite3DbMallocZero(db, sizeof(TriggerPrg));

  132875.   if( !pPrg ) return 0;

  132876.   pPrg->pNext = pTop->pTriggerPrg;

  132877.   pTop->pTriggerPrg = pPrg;

  132878.   pPrg->pProgram = pProgram = sqlite3DbMallocZero(db, sizeof(SubProgram));

  132879.   if( !pProgram ) return 0;

  132880.   sqlite3VdbeLinkSubProgram(pTop->pVdbe, pProgram);

  132881.   pPrg->pTrigger = pTrigger;

  132882.   pPrg->orconf = orconf;

  132883.   pPrg->aColmask[0] = 0xffffffff;

  132884.   pPrg->aColmask[1] = 0xffffffff;

  132885. 

  132886.   /* Allocate and populate a new Parse context to use for coding the 

  132887.   ** trigger sub-program.  */

  132888.   pSubParse = sqlite3StackAllocZero(db, sizeof(Parse));

  132889.   if( !pSubParse ) return 0;

  132890.   memset(&sNC, 0, sizeof(sNC));

  132891.   sNC.pParse = pSubParse;

  132892.   pSubParse->db = db;

  132893.   pSubParse->pTriggerTab = pTab;

  132894.   pSubParse->pToplevel = pTop;

  132895.   pSubParse->zAuthContext = pTrigger->zName;

  132896.   pSubParse->eTriggerOp = pTrigger->op;

  132897.   pSubParse->nQueryLoop = pParse->nQueryLoop;

  132898.   pSubParse->disableVtab = pParse->disableVtab;

  132899. 

  132900.   v = sqlite3GetVdbe(pSubParse);

  132901.   if( v ){

  132902.     VdbeComment((v, "Start: %s.%s (%s %s%s%s ON %s)", 

  132903.       pTrigger->zName, onErrorText(orconf),

  132904.       (pTrigger->tr_tm==TRIGGER_BEFORE ? "BEFORE" : "AFTER"),

  132905.         (pTrigger->op==TK_UPDATE ? "UPDATE" : ""),

  132906.         (pTrigger->op==TK_INSERT ? "INSERT" : ""),

  132907.         (pTrigger->op==TK_DELETE ? "DELETE" : ""),

  132908.       pTab->zName

  132909.     ));

  132910. #ifndef SQLITE_OMIT_TRACE

  132911.     if( pTrigger->zName ){

  132912.       sqlite3VdbeChangeP4(v, -1, 

  132913.         sqlite3MPrintf(db, "-- TRIGGER %s", pTrigger->zName), P4_DYNAMIC

  132914.       );

  132915.     }

  132916. #endif

  132917. 

  132918.     /* If one was specified, code the WHEN clause. If it evaluates to false

  132919.     ** (or NULL) the sub-vdbe is immediately halted by jumping to the 

  132920.     ** OP_Halt inserted at the end of the program.  */

  132921.     if( pTrigger->pWhen ){

  132922.       pWhen = sqlite3ExprDup(db, pTrigger->pWhen, 0);

  132923.       if( SQLITE_OK==sqlite3ResolveExprNames(&sNC, pWhen) 

  132924.        && db->mallocFailed==0 

  132925.       ){

  132926.         iEndTrigger = sqlite3VdbeMakeLabel(pSubParse);

  132927.         sqlite3ExprIfFalse(pSubParse, pWhen, iEndTrigger, SQLITE_JUMPIFNULL);

  132928.       }

  132929.       sqlite3ExprDelete(db, pWhen);

  132930.     }

  132931. 

  132932.     /* Code the trigger program into the sub-vdbe. */

  132933.     codeTriggerProgram(pSubParse, pTrigger->step_list, orconf);

  132934. 

  132935.     /* Insert an OP_Halt at the end of the sub-program. */

  132936.     if( iEndTrigger ){

  132937.       sqlite3VdbeResolveLabel(v, iEndTrigger);

  132938.     }

  132939.     sqlite3VdbeAddOp0(v, OP_Halt);

  132940.     VdbeComment((v, "End: %s.%s", pTrigger->zName, onErrorText(orconf)));

  132941. 

  132942.     transferParseError(pParse, pSubParse);

  132943.     if( db->mallocFailed==0 && pParse->nErr==0 ){

  132944.       pProgram->aOp = sqlite3VdbeTakeOpArray(v, &pProgram->nOp, &pTop->nMaxArg);

  132945.     }

  132946.     pProgram->nMem = pSubParse->nMem;

  132947.     pProgram->nCsr = pSubParse->nTab;

  132948.     pProgram->token = (void *)pTrigger;

  132949.     pPrg->aColmask[0] = pSubParse->oldmask;

  132950.     pPrg->aColmask[1] = pSubParse->newmask;

  132951.     sqlite3VdbeDelete(v);

  132952.   }

  132953. 

  132954.   assert( !pSubParse->pAinc       && !pSubParse->pZombieTab );

  132955.   assert( !pSubParse->pTriggerPrg && !pSubParse->nMaxArg );

  132956.   sqlite3ParserReset(pSubParse);

  132957.   sqlite3StackFree(db, pSubParse);

  132958. 

  132959.   return pPrg;

  132960. }

  132961.     

  132962. /*

  132963. ** Return a pointer to a TriggerPrg object containing the sub-program for

  132964. ** trigger pTrigger with default ON CONFLICT algorithm orconf. If no such

  132965. ** TriggerPrg object exists, a new object is allocated and populated before

  132966. ** being returned.

  132967. */

  132968. static TriggerPrg *getRowTrigger(

  132969.   Parse *pParse,       /* Current parse context */

  132970.   Trigger *pTrigger,   /* Trigger to code */

  132971.   Table *pTab,         /* The table trigger pTrigger is attached to */

  132972.   int orconf           /* ON CONFLICT algorithm. */

  132973. ){

  132974.   Parse *pRoot = sqlite3ParseToplevel(pParse);

  132975.   TriggerPrg *pPrg;

  132976. 

  132977.   assert( pTrigger->zName==0 || pTab==tableOfTrigger(pTrigger) );

  132978. 

  132979.   /* It may be that this trigger has already been coded (or is in the

  132980.   ** process of being coded). If this is the case, then an entry with

  132981.   ** a matching TriggerPrg.pTrigger field will be present somewhere

  132982.   ** in the Parse.pTriggerPrg list. Search for such an entry.  */

  132983.   for(pPrg=pRoot->pTriggerPrg; 

  132984.       pPrg && (pPrg->pTrigger!=pTrigger || pPrg->orconf!=orconf); 

  132985.       pPrg=pPrg->pNext

  132986.   );

  132987. 

  132988.   /* If an existing TriggerPrg could not be located, create a new one. */

  132989.   if( !pPrg ){

  132990.     pPrg = codeRowTrigger(pParse, pTrigger, pTab, orconf);

  132991.   }

  132992. 

  132993.   return pPrg;

  132994. }

  132995. 

  132996. /*

  132997. ** Generate code for the trigger program associated with trigger p on 

  132998. ** table pTab. The reg, orconf and ignoreJump parameters passed to this

  132999. ** function are the same as those described in the header function for

  133000. ** sqlite3CodeRowTrigger()

  133001. */

  133002. SQLITE_PRIVATE void sqlite3CodeRowTriggerDirect(

  133003.   Parse *pParse,       /* Parse context */

  133004.   Trigger *p,          /* Trigger to code */

  133005.   Table *pTab,         /* The table to code triggers from */

  133006.   int reg,             /* Reg array containing OLD.* and NEW.* values */

  133007.   int orconf,          /* ON CONFLICT policy */

  133008.   int ignoreJump       /* Instruction to jump to for RAISE(IGNORE) */

  133009. ){

  133010.   Vdbe *v = sqlite3GetVdbe(pParse); /* Main VM */

  133011.   TriggerPrg *pPrg;

  133012.   pPrg = getRowTrigger(pParse, p, pTab, orconf);

  133013.   assert( pPrg || pParse->nErr || pParse->db->mallocFailed );

  133014. 

  133015.   /* Code the OP_Program opcode in the parent VDBE. P4 of the OP_Program 

  133016.   ** is a pointer to the sub-vdbe containing the trigger program.  */

  133017.   if( pPrg ){

  133018.     int bRecursive = (p->zName && 0==(pParse->db->flags&SQLITE_RecTriggers));

  133019. 

  133020.     sqlite3VdbeAddOp4(v, OP_Program, reg, ignoreJump, ++pParse->nMem,

  133021.                       (const char *)pPrg->pProgram, P4_SUBPROGRAM);

  133022.     VdbeComment(

  133023.         (v, "Call: %s.%s", (p->zName?p->zName:"fkey"), onErrorText(orconf)));

  133024. 

  133025.     /* Set the P5 operand of the OP_Program instruction to non-zero if

  133026.     ** recursive invocation of this trigger program is disallowed. Recursive

  133027.     ** invocation is disallowed if (a) the sub-program is really a trigger,

  133028.     ** not a foreign key action, and (b) the flag to enable recursive triggers

  133029.     ** is clear.  */

  133030.     sqlite3VdbeChangeP5(v, (u8)bRecursive);

  133031.   }

  133032. }

  133033. 

  133034. /*

  133035. ** This is called to code the required FOR EACH ROW triggers for an operation

  133036. ** on table pTab. The operation to code triggers for (INSERT, UPDATE or DELETE)

  133037. ** is given by the op parameter. The tr_tm parameter determines whether the

  133038. ** BEFORE or AFTER triggers are coded. If the operation is an UPDATE, then

  133039. ** parameter pChanges is passed the list of columns being modified.

  133040. **

  133041. ** If there are no triggers that fire at the specified time for the specified

  133042. ** operation on pTab, this function is a no-op.

  133043. **

  133044. ** The reg argument is the address of the first in an array of registers 

  133045. ** that contain the values substituted for the new.* and old.* references

  133046. ** in the trigger program. If N is the number of columns in table pTab

  133047. ** (a copy of pTab->nCol), then registers are populated as follows:

  133048. **

  133049. **   Register       Contains

  133050. **   ------------------------------------------------------

  133051. **   reg+0          OLD.rowid

  133052. **   reg+1          OLD.* value of left-most column of pTab

  133053. **   ...            ...

  133054. **   reg+N          OLD.* value of right-most column of pTab

  133055. **   reg+N+1        NEW.rowid

  133056. **   reg+N+2        OLD.* value of left-most column of pTab

  133057. **   ...            ...

  133058. **   reg+N+N+1      NEW.* value of right-most column of pTab

  133059. **

  133060. ** For ON DELETE triggers, the registers containing the NEW.* values will

  133061. ** never be accessed by the trigger program, so they are not allocated or 

  133062. ** populated by the caller (there is no data to populate them with anyway). 

  133063. ** Similarly, for ON INSERT triggers the values stored in the OLD.* registers

  133064. ** are never accessed, and so are not allocated by the caller. So, for an

  133065. ** ON INSERT trigger, the value passed to this function as parameter reg

  133066. ** is not a readable register, although registers (reg+N) through 

  133067. ** (reg+N+N+1) are.

  133068. **

  133069. ** Parameter orconf is the default conflict resolution algorithm for the

  133070. ** trigger program to use (REPLACE, IGNORE etc.). Parameter ignoreJump

  133071. ** is the instruction that control should jump to if a trigger program

  133072. ** raises an IGNORE exception.

  133073. */

  133074. SQLITE_PRIVATE void sqlite3CodeRowTrigger(

  133075.   Parse *pParse,       /* Parse context */

  133076.   Trigger *pTrigger,   /* List of triggers on table pTab */

  133077.   int op,              /* One of TK_UPDATE, TK_INSERT, TK_DELETE */

  133078.   ExprList *pChanges,  /* Changes list for any UPDATE OF triggers */

  133079.   int tr_tm,           /* One of TRIGGER_BEFORE, TRIGGER_AFTER */

  133080.   Table *pTab,         /* The table to code triggers from */

  133081.   int reg,             /* The first in an array of registers (see above) */

  133082.   int orconf,          /* ON CONFLICT policy */

  133083.   int ignoreJump       /* Instruction to jump to for RAISE(IGNORE) */

  133084. ){

  133085.   Trigger *p;          /* Used to iterate through pTrigger list */

  133086. 

  133087.   assert( op==TK_UPDATE || op==TK_INSERT || op==TK_DELETE );

  133088.   assert( tr_tm==TRIGGER_BEFORE || tr_tm==TRIGGER_AFTER );

  133089.   assert( (op==TK_UPDATE)==(pChanges!=0) );

  133090. 

  133091.   for(p=pTrigger; p; p=p->pNext){

  133092. 

  133093.     /* Sanity checking:  The schema for the trigger and for the table are

  133094.     ** always defined.  The trigger must be in the same schema as the table

  133095.     ** or else it must be a TEMP trigger. */

  133096.     assert( p->pSchema!=0 );

  133097.     assert( p->pTabSchema!=0 );

  133098.     assert( p->pSchema==p->pTabSchema 

  133099.          || p->pSchema==pParse->db->aDb[1].pSchema );

  133100. 

  133101.     /* Determine whether we should code this trigger */

  133102.     if( p->op==op 

  133103.      && p->tr_tm==tr_tm 

  133104.      && checkColumnOverlap(p->pColumns, pChanges)

  133105.     ){

  133106.       sqlite3CodeRowTriggerDirect(pParse, p, pTab, reg, orconf, ignoreJump);

  133107.     }

  133108.   }

  133109. }

  133110. 

  133111. /*

  133112. ** Triggers may access values stored in the old.* or new.* pseudo-table. 

  133113. ** This function returns a 32-bit bitmask indicating which columns of the 

  133114. ** old.* or new.* tables actually are used by triggers. This information 

  133115. ** may be used by the caller, for example, to avoid having to load the entire

  133116. ** old.* record into memory when executing an UPDATE or DELETE command.

  133117. **

  133118. ** Bit 0 of the returned mask is set if the left-most column of the

  133119. ** table may be accessed using an [old|new].<col> reference. Bit 1 is set if

  133120. ** the second leftmost column value is required, and so on. If there

  133121. ** are more than 32 columns in the table, and at least one of the columns

  133122. ** with an index greater than 32 may be accessed, 0xffffffff is returned.

  133123. **

  133124. ** It is not possible to determine if the old.rowid or new.rowid column is 

  133125. ** accessed by triggers. The caller must always assume that it is.

  133126. **

  133127. ** Parameter isNew must be either 1 or 0. If it is 0, then the mask returned

  133128. ** applies to the old.* table. If 1, the new.* table.

  133129. **

  133130. ** Parameter tr_tm must be a mask with one or both of the TRIGGER_BEFORE

  133131. ** and TRIGGER_AFTER bits set. Values accessed by BEFORE triggers are only

  133132. ** included in the returned mask if the TRIGGER_BEFORE bit is set in the

  133133. ** tr_tm parameter. Similarly, values accessed by AFTER triggers are only

  133134. ** included in the returned mask if the TRIGGER_AFTER bit is set in tr_tm.

  133135. */

  133136. SQLITE_PRIVATE u32 sqlite3TriggerColmask(

  133137.   Parse *pParse,       /* Parse context */

  133138.   Trigger *pTrigger,   /* List of triggers on table pTab */

  133139.   ExprList *pChanges,  /* Changes list for any UPDATE OF triggers */

  133140.   int isNew,           /* 1 for new.* ref mask, 0 for old.* ref mask */

  133141.   int tr_tm,           /* Mask of TRIGGER_BEFORE|TRIGGER_AFTER */

  133142.   Table *pTab,         /* The table to code triggers from */

  133143.   int orconf           /* Default ON CONFLICT policy for trigger steps */

  133144. ){

  133145.   const int op = pChanges ? TK_UPDATE : TK_DELETE;

  133146.   u32 mask = 0;

  133147.   Trigger *p;

  133148. 

  133149.   assert( isNew==1 || isNew==0 );

  133150.   for(p=pTrigger; p; p=p->pNext){

  133151.     if( p->op==op && (tr_tm&p->tr_tm)

  133152.      && checkColumnOverlap(p->pColumns,pChanges)

  133153.     ){

  133154.       TriggerPrg *pPrg;

  133155.       pPrg = getRowTrigger(pParse, p, pTab, orconf);

  133156.       if( pPrg ){

  133157.         mask |= pPrg->aColmask[isNew];

  133158.       }

  133159.     }

  133160.   }

  133161. 

  133162.   return mask;

  133163. }

  133164. 

  133165. #endif /* !defined(SQLITE_OMIT_TRIGGER) */

  133166. 

  133167. /************** End of trigger.c *********************************************/

  133168. /************** Begin file update.c ******************************************/

  133169. /*

  133170. ** 2001 September 15

  133171. **

  133172. ** The author disclaims copyright to this source code.  In place of

  133173. ** a legal notice, here is a blessing:

  133174. **

  133175. **    May you do good and not evil.

  133176. **    May you find forgiveness for yourself and forgive others.

  133177. **    May you share freely, never taking more than you give.

  133178. **

  133179. *************************************************************************

  133180. ** This file contains C code routines that are called by the parser

  133181. ** to handle UPDATE statements.

  133182. */

  133183. /* #include "sqliteInt.h" */

  133184. 

  133185. #ifndef SQLITE_OMIT_VIRTUALTABLE

  133186. /* Forward declaration */

  133187. static void updateVirtualTable(

  133188.   Parse *pParse,       /* The parsing context */

  133189.   SrcList *pSrc,       /* The virtual table to be modified */

  133190.   Table *pTab,         /* The virtual table */

  133191.   ExprList *pChanges,  /* The columns to change in the UPDATE statement */

  133192.   Expr *pRowidExpr,    /* Expression used to recompute the rowid */

  133193.   int *aXRef,          /* Mapping from columns of pTab to entries in pChanges */

  133194.   Expr *pWhere,        /* WHERE clause of the UPDATE statement */

  133195.   int onError          /* ON CONFLICT strategy */

  133196. );

  133197. #endif /* SQLITE_OMIT_VIRTUALTABLE */

  133198. 

  133199. /*

  133200. ** The most recently coded instruction was an OP_Column to retrieve the

  133201. ** i-th column of table pTab. This routine sets the P4 parameter of the 

  133202. ** OP_Column to the default value, if any.

  133203. **

  133204. ** The default value of a column is specified by a DEFAULT clause in the 

  133205. ** column definition. This was either supplied by the user when the table

  133206. ** was created, or added later to the table definition by an ALTER TABLE

  133207. ** command. If the latter, then the row-records in the table btree on disk

  133208. ** may not contain a value for the column and the default value, taken

  133209. ** from the P4 parameter of the OP_Column instruction, is returned instead.

  133210. ** If the former, then all row-records are guaranteed to include a value

  133211. ** for the column and the P4 value is not required.

  133212. **

  133213. ** Column definitions created by an ALTER TABLE command may only have 

  133214. ** literal default values specified: a number, null or a string. (If a more

  133215. ** complicated default expression value was provided, it is evaluated 

  133216. ** when the ALTER TABLE is executed and one of the literal values written

  133217. ** into the sqlite_master table.)

  133218. **

  133219. ** Therefore, the P4 parameter is only required if the default value for

  133220. ** the column is a literal number, string or null. The sqlite3ValueFromExpr()

  133221. ** function is capable of transforming these types of expressions into

  133222. ** sqlite3_value objects.

  133223. **

  133224. ** If parameter iReg is not negative, code an OP_RealAffinity instruction

  133225. ** on register iReg. This is used when an equivalent integer value is 

  133226. ** stored in place of an 8-byte floating point value in order to save 

  133227. ** space.

  133228. */

  133229. SQLITE_PRIVATE void sqlite3ColumnDefault(Vdbe *v, Table *pTab, int i, int iReg){

  133230.   assert( pTab!=0 );

  133231.   if( !pTab->pSelect ){

  133232.     sqlite3_value *pValue = 0;

  133233.     u8 enc = ENC(sqlite3VdbeDb(v));

  133234.     Column *pCol = &pTab->aCol[i];

  133235.     VdbeComment((v, "%s.%s", pTab->zName, pCol->zName));

  133236.     assert( i<pTab->nCol );

  133237.     sqlite3ValueFromExpr(sqlite3VdbeDb(v), pCol->pDflt, enc, 

  133238.                          pCol->affinity, &pValue);

  133239.     if( pValue ){

  133240.       sqlite3VdbeAppendP4(v, pValue, P4_MEM);

  133241.     }

  133242.   }

  133243. #ifndef SQLITE_OMIT_FLOATING_POINT

  133244.   if( pTab->aCol[i].affinity==SQLITE_AFF_REAL ){

  133245.     sqlite3VdbeAddOp1(v, OP_RealAffinity, iReg);

  133246.   }

  133247. #endif

  133248. }

  133249. 

  133250. /*

  133251. ** Check to see if column iCol of index pIdx references any of the

  133252. ** columns defined by aXRef and chngRowid.  Return true if it does

  133253. ** and false if not.  This is an optimization.  False-positives are a

  133254. ** performance degradation, but false-negatives can result in a corrupt

  133255. ** index and incorrect answers.

  133256. **

  133257. ** aXRef[j] will be non-negative if column j of the original table is

  133258. ** being updated.  chngRowid will be true if the rowid of the table is

  133259. ** being updated.

  133260. */

  133261. static int indexColumnIsBeingUpdated(

  133262.   Index *pIdx,      /* The index to check */

  133263.   int iCol,         /* Which column of the index to check */

  133264.   int *aXRef,       /* aXRef[j]>=0 if column j is being updated */

  133265.   int chngRowid     /* true if the rowid is being updated */

  133266. ){

  133267.   i16 iIdxCol = pIdx->aiColumn[iCol];

  133268.   assert( iIdxCol!=XN_ROWID ); /* Cannot index rowid */

  133269.   if( iIdxCol>=0 ){

  133270.     return aXRef[iIdxCol]>=0;

  133271.   }

  133272.   assert( iIdxCol==XN_EXPR );

  133273.   assert( pIdx->aColExpr!=0 );

  133274.   assert( pIdx->aColExpr->a[iCol].pExpr!=0 );

  133275.   return sqlite3ExprReferencesUpdatedColumn(pIdx->aColExpr->a[iCol].pExpr,

  133276.                                             aXRef,chngRowid);

  133277. }

  133278. 

  133279. /*

  133280. ** Check to see if index pIdx is a partial index whose conditional

  133281. ** expression might change values due to an UPDATE.  Return true if

  133282. ** the index is subject to change and false if the index is guaranteed

  133283. ** to be unchanged.  This is an optimization.  False-positives are a

  133284. ** performance degradation, but false-negatives can result in a corrupt

  133285. ** index and incorrect answers.

  133286. **

  133287. ** aXRef[j] will be non-negative if column j of the original table is

  133288. ** being updated.  chngRowid will be true if the rowid of the table is

  133289. ** being updated.

  133290. */

  133291. static int indexWhereClauseMightChange(

  133292.   Index *pIdx,      /* The index to check */

  133293.   int *aXRef,       /* aXRef[j]>=0 if column j is being updated */

  133294.   int chngRowid     /* true if the rowid is being updated */

  133295. ){

  133296.   if( pIdx->pPartIdxWhere==0 ) return 0;

  133297.   return sqlite3ExprReferencesUpdatedColumn(pIdx->pPartIdxWhere,

  133298.                                             aXRef, chngRowid);

  133299. }

  133300. 

  133301. /*

  133302. ** Process an UPDATE statement.

  133303. **

  133304. **   UPDATE OR IGNORE table_wxyz SET a=b, c=d WHERE e<5 AND f NOT NULL;

  133305. **          \_______/ \________/     \______/       \________________/

  133306. *            onError   pTabList      pChanges             pWhere

  133307. */

  133308. SQLITE_PRIVATE void sqlite3Update(

  133309.   Parse *pParse,         /* The parser context */

  133310.   SrcList *pTabList,     /* The table in which we should change things */

  133311.   ExprList *pChanges,    /* Things to be changed */

  133312.   Expr *pWhere,          /* The WHERE clause.  May be null */

  133313.   int onError,           /* How to handle constraint errors */

  133314.   ExprList *pOrderBy,    /* ORDER BY clause. May be null */

  133315.   Expr *pLimit,          /* LIMIT clause. May be null */

  133316.   Upsert *pUpsert        /* ON CONFLICT clause, or null */

  133317. ){

  133318.   int i, j;              /* Loop counters */

  133319.   Table *pTab;           /* The table to be updated */

  133320.   int addrTop = 0;       /* VDBE instruction address of the start of the loop */

  133321.   WhereInfo *pWInfo;     /* Information about the WHERE clause */

  133322.   Vdbe *v;               /* The virtual database engine */

  133323.   Index *pIdx;           /* For looping over indices */

  133324.   Index *pPk;            /* The PRIMARY KEY index for WITHOUT ROWID tables */

  133325.   int nIdx;              /* Number of indices that need updating */

  133326.   int nAllIdx;           /* Total number of indexes */

  133327.   int iBaseCur;          /* Base cursor number */

  133328.   int iDataCur;          /* Cursor for the canonical data btree */

  133329.   int iIdxCur;           /* Cursor for the first index */

  133330.   sqlite3 *db;           /* The database structure */

  133331.   int *aRegIdx = 0;      /* Registers for to each index and the main table */

  133332.   int *aXRef = 0;        /* aXRef[i] is the index in pChanges->a[] of the

  133333.                          ** an expression for the i-th column of the table.

  133334.                          ** aXRef[i]==-1 if the i-th column is not changed. */

  133335.   u8 *aToOpen;           /* 1 for tables and indices to be opened */

  133336.   u8 chngPk;             /* PRIMARY KEY changed in a WITHOUT ROWID table */

  133337.   u8 chngRowid;          /* Rowid changed in a normal table */

  133338.   u8 chngKey;            /* Either chngPk or chngRowid */

  133339.   Expr *pRowidExpr = 0;  /* Expression defining the new record number */

  133340.   AuthContext sContext;  /* The authorization context */

  133341.   NameContext sNC;       /* The name-context to resolve expressions in */

  133342.   int iDb;               /* Database containing the table being updated */

  133343.   int eOnePass;          /* ONEPASS_XXX value from where.c */

  133344.   int hasFK;             /* True if foreign key processing is required */

  133345.   int labelBreak;        /* Jump here to break out of UPDATE loop */

  133346.   int labelContinue;     /* Jump here to continue next step of UPDATE loop */

  133347.   int flags;             /* Flags for sqlite3WhereBegin() */

  133348. 

  133349. #ifndef SQLITE_OMIT_TRIGGER

  133350.   int isView;            /* True when updating a view (INSTEAD OF trigger) */

  133351.   Trigger *pTrigger;     /* List of triggers on pTab, if required */

  133352.   int tmask;             /* Mask of TRIGGER_BEFORE|TRIGGER_AFTER */

  133353. #endif

  133354.   int newmask;           /* Mask of NEW.* columns accessed by BEFORE triggers */

  133355.   int iEph = 0;          /* Ephemeral table holding all primary key values */

  133356.   int nKey = 0;          /* Number of elements in regKey for WITHOUT ROWID */

  133357.   int aiCurOnePass[2];   /* The write cursors opened by WHERE_ONEPASS */

  133358.   int addrOpen = 0;      /* Address of OP_OpenEphemeral */

  133359.   int iPk = 0;           /* First of nPk cells holding PRIMARY KEY value */

  133360.   i16 nPk = 0;           /* Number of components of the PRIMARY KEY */

  133361.   int bReplace = 0;      /* True if REPLACE conflict resolution might happen */

  133362. 

  133363.   /* Register Allocations */

  133364.   int regRowCount = 0;   /* A count of rows changed */

  133365.   int regOldRowid = 0;   /* The old rowid */

  133366.   int regNewRowid = 0;   /* The new rowid */

  133367.   int regNew = 0;        /* Content of the NEW.* table in triggers */

  133368.   int regOld = 0;        /* Content of OLD.* table in triggers */

  133369.   int regRowSet = 0;     /* Rowset of rows to be updated */

  133370.   int regKey = 0;        /* composite PRIMARY KEY value */

  133371. 

  133372.   memset(&sContext, 0, sizeof(sContext));

  133373.   db = pParse->db;

  133374.   if( pParse->nErr || db->mallocFailed ){

  133375.     goto update_cleanup;

  133376.   }

  133377.   assert( pTabList->nSrc==1 );

  133378. 

  133379.   /* Locate the table which we want to update. 

  133380.   */

  133381.   pTab = sqlite3SrcListLookup(pParse, pTabList);

  133382.   if( pTab==0 ) goto update_cleanup;

  133383.   iDb = sqlite3SchemaToIndex(pParse->db, pTab->pSchema);

  133384. 

  133385.   /* Figure out if we have any triggers and if the table being

  133386.   ** updated is a view.

  133387.   */

  133388. #ifndef SQLITE_OMIT_TRIGGER

  133389.   pTrigger = sqlite3TriggersExist(pParse, pTab, TK_UPDATE, pChanges, &tmask);

  133390.   isView = pTab->pSelect!=0;

  133391.   assert( pTrigger || tmask==0 );

  133392. #else

  133393. # define pTrigger 0

  133394. # define isView 0

  133395. # define tmask 0

  133396. #endif

  133397. #ifdef SQLITE_OMIT_VIEW

  133398. # undef isView

  133399. # define isView 0

  133400. #endif

  133401. 

  133402. #ifdef SQLITE_ENABLE_UPDATE_DELETE_LIMIT

  133403.   if( !isView ){

  133404.     pWhere = sqlite3LimitWhere(

  133405.         pParse, pTabList, pWhere, pOrderBy, pLimit, "UPDATE"

  133406.     );

  133407.     pOrderBy = 0;

  133408.     pLimit = 0;

  133409.   }

  133410. #endif

  133411. 

  133412.   if( sqlite3ViewGetColumnNames(pParse, pTab) ){

  133413.     goto update_cleanup;

  133414.   }

  133415.   if( sqlite3IsReadOnly(pParse, pTab, tmask) ){

  133416.     goto update_cleanup;

  133417.   }

  133418. 

  133419.   /* Allocate a cursors for the main database table and for all indices.

  133420.   ** The index cursors might not be used, but if they are used they

  133421.   ** need to occur right after the database cursor.  So go ahead and

  133422.   ** allocate enough space, just in case.

  133423.   */

  133424.   iBaseCur = iDataCur = pParse->nTab++;

  133425.   iIdxCur = iDataCur+1;

  133426.   pPk = HasRowid(pTab) ? 0 : sqlite3PrimaryKeyIndex(pTab);

  133427.   testcase( pPk!=0 && pPk!=pTab->pIndex );

  133428.   for(nIdx=0, pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext, nIdx++){

  133429.     if( pPk==pIdx ){

  133430.       iDataCur = pParse->nTab;

  133431.     }

  133432.     pParse->nTab++;

  133433.   }

  133434.   if( pUpsert ){

  133435.     /* On an UPSERT, reuse the same cursors already opened by INSERT */

  133436.     iDataCur = pUpsert->iDataCur;

  133437.     iIdxCur = pUpsert->iIdxCur;

  133438.     pParse->nTab = iBaseCur;

  133439.   }

  133440.   pTabList->a[0].iCursor = iDataCur;

  133441. 

  133442.   /* Allocate space for aXRef[], aRegIdx[], and aToOpen[].  

  133443.   ** Initialize aXRef[] and aToOpen[] to their default values.

  133444.   */

  133445.   aXRef = sqlite3DbMallocRawNN(db, sizeof(int) * (pTab->nCol+nIdx+1) + nIdx+2 );

  133446.   if( aXRef==0 ) goto update_cleanup;

  133447.   aRegIdx = aXRef+pTab->nCol;

  133448.   aToOpen = (u8*)(aRegIdx+nIdx+1);

  133449.   memset(aToOpen, 1, nIdx+1);

  133450.   aToOpen[nIdx+1] = 0;

  133451.   for(i=0; i<pTab->nCol; i++) aXRef[i] = -1;

  133452. 

  133453.   /* Initialize the name-context */

  133454.   memset(&sNC, 0, sizeof(sNC));

  133455.   sNC.pParse = pParse;

  133456.   sNC.pSrcList = pTabList;

  133457.   sNC.uNC.pUpsert = pUpsert;

  133458.   sNC.ncFlags = NC_UUpsert;

  133459. 

  133460.   /* Resolve the column names in all the expressions of the

  133461.   ** of the UPDATE statement.  Also find the column index

  133462.   ** for each column to be updated in the pChanges array.  For each

  133463.   ** column to be updated, make sure we have authorization to change

  133464.   ** that column.

  133465.   */

  133466.   chngRowid = chngPk = 0;

  133467.   for(i=0; i<pChanges->nExpr; i++){

  133468.     if( sqlite3ResolveExprNames(&sNC, pChanges->a[i].pExpr) ){

  133469.       goto update_cleanup;

  133470.     }

  133471.     for(j=0; j<pTab->nCol; j++){

  133472.       if( sqlite3StrICmp(pTab->aCol[j].zName, pChanges->a[i].zName)==0 ){

  133473.         if( j==pTab->iPKey ){

  133474.           chngRowid = 1;

  133475.           pRowidExpr = pChanges->a[i].pExpr;

  133476.         }else if( pPk && (pTab->aCol[j].colFlags & COLFLAG_PRIMKEY)!=0 ){

  133477.           chngPk = 1;

  133478.         }

  133479.         aXRef[j] = i;

  133480.         break;

  133481.       }

  133482.     }

  133483.     if( j>=pTab->nCol ){

  133484.       if( pPk==0 && sqlite3IsRowid(pChanges->a[i].zName) ){

  133485.         j = -1;

  133486.         chngRowid = 1;

  133487.         pRowidExpr = pChanges->a[i].pExpr;

  133488.       }else{

  133489.         sqlite3ErrorMsg(pParse, "no such column: %s", pChanges->a[i].zName);

  133490.         pParse->checkSchema = 1;

  133491.         goto update_cleanup;

  133492.       }

  133493.     }

  133494. #ifndef SQLITE_OMIT_AUTHORIZATION

  133495.     {

  133496.       int rc;

  133497.       rc = sqlite3AuthCheck(pParse, SQLITE_UPDATE, pTab->zName,

  133498.                             j<0 ? "ROWID" : pTab->aCol[j].zName,

  133499.                             db->aDb[iDb].zDbSName);

  133500.       if( rc==SQLITE_DENY ){

  133501.         goto update_cleanup;

  133502.       }else if( rc==SQLITE_IGNORE ){

  133503.         aXRef[j] = -1;

  133504.       }

  133505.     }

  133506. #endif

  133507.   }

  133508.   assert( (chngRowid & chngPk)==0 );

  133509.   assert( chngRowid==0 || chngRowid==1 );

  133510.   assert( chngPk==0 || chngPk==1 );

  133511.   chngKey = chngRowid + chngPk;

  133512. 

  133513.   /* The SET expressions are not actually used inside the WHERE loop.  

  133514.   ** So reset the colUsed mask. Unless this is a virtual table. In that

  133515.   ** case, set all bits of the colUsed mask (to ensure that the virtual

  133516.   ** table implementation makes all columns available).

  133517.   */

  133518.   pTabList->a[0].colUsed = IsVirtual(pTab) ? ALLBITS : 0;

  133519. 

  133520.   hasFK = sqlite3FkRequired(pParse, pTab, aXRef, chngKey);

  133521. 

  133522.   /* There is one entry in the aRegIdx[] array for each index on the table

  133523.   ** being updated.  Fill in aRegIdx[] with a register number that will hold

  133524.   ** the key for accessing each index.

  133525.   */

  133526.   if( onError==OE_Replace ) bReplace = 1;

  133527.   for(nAllIdx=0, pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext, nAllIdx++){

  133528.     int reg;

  133529.     if( chngKey || hasFK>1 || pIdx==pPk

  133530.      || indexWhereClauseMightChange(pIdx,aXRef,chngRowid)

  133531.     ){

  133532.       reg = ++pParse->nMem;

  133533.       pParse->nMem += pIdx->nColumn;

  133534.     }else{

  133535.       reg = 0;

  133536.       for(i=0; i<pIdx->nKeyCol; i++){

  133537.         if( indexColumnIsBeingUpdated(pIdx, i, aXRef, chngRowid) ){

  133538.           reg = ++pParse->nMem;

  133539.           pParse->nMem += pIdx->nColumn;

  133540.           if( onError==OE_Default && pIdx->onError==OE_Replace ){

  133541.             bReplace = 1;

  133542.           }

  133543.           break;

  133544.         }

  133545.       }

  133546.     }

  133547.     if( reg==0 ) aToOpen[nAllIdx+1] = 0;

  133548.     aRegIdx[nAllIdx] = reg;

  133549.   }

  133550.   aRegIdx[nAllIdx] = ++pParse->nMem;  /* Register storing the table record */

  133551.   if( bReplace ){

  133552.     /* If REPLACE conflict resolution might be invoked, open cursors on all 

  133553.     ** indexes in case they are needed to delete records.  */

  133554.     memset(aToOpen, 1, nIdx+1);

  133555.   }

  133556. 

  133557.   /* Begin generating code. */

  133558.   v = sqlite3GetVdbe(pParse);

  133559.   if( v==0 ) goto update_cleanup;

  133560.   if( pParse->nested==0 ) sqlite3VdbeCountChanges(v);

  133561.   sqlite3BeginWriteOperation(pParse, pTrigger || hasFK, iDb);

  133562. 

  133563.   /* Allocate required registers. */

  133564.   if( !IsVirtual(pTab) ){

  133565.     /* For now, regRowSet and aRegIdx[nAllIdx] share the same register.

  133566.     ** If regRowSet turns out to be needed, then aRegIdx[nAllIdx] will be

  133567.     ** reallocated.  aRegIdx[nAllIdx] is the register in which the main

  133568.     ** table record is written.  regRowSet holds the RowSet for the

  133569.     ** two-pass update algorithm. */

  133570.     assert( aRegIdx[nAllIdx]==pParse->nMem );

  133571.     regRowSet = aRegIdx[nAllIdx];

  133572.     regOldRowid = regNewRowid = ++pParse->nMem;

  133573.     if( chngPk || pTrigger || hasFK ){

  133574.       regOld = pParse->nMem + 1;

  133575.       pParse->nMem += pTab->nCol;

  133576.     }

  133577.     if( chngKey || pTrigger || hasFK ){

  133578.       regNewRowid = ++pParse->nMem;

  133579.     }

  133580.     regNew = pParse->nMem + 1;

  133581.     pParse->nMem += pTab->nCol;

  133582.   }

  133583. 

  133584.   /* Start the view context. */

  133585.   if( isView ){

  133586.     sqlite3AuthContextPush(pParse, &sContext, pTab->zName);

  133587.   }

  133588. 

  133589.   /* If we are trying to update a view, realize that view into

  133590.   ** an ephemeral table.

  133591.   */

  133592. #if !defined(SQLITE_OMIT_VIEW) && !defined(SQLITE_OMIT_TRIGGER)

  133593.   if( isView ){

  133594.     sqlite3MaterializeView(pParse, pTab, 

  133595.         pWhere, pOrderBy, pLimit, iDataCur

  133596.     );

  133597.     pOrderBy = 0;

  133598.     pLimit = 0;

  133599.   }

  133600. #endif

  133601. 

  133602.   /* Resolve the column names in all the expressions in the

  133603.   ** WHERE clause.

  133604.   */

  133605.   if( sqlite3ResolveExprNames(&sNC, pWhere) ){

  133606.     goto update_cleanup;

  133607.   }

  133608. 

  133609. #ifndef SQLITE_OMIT_VIRTUALTABLE

  133610.   /* Virtual tables must be handled separately */

  133611.   if( IsVirtual(pTab) ){

  133612.     updateVirtualTable(pParse, pTabList, pTab, pChanges, pRowidExpr, aXRef,

  133613.                        pWhere, onError);

  133614.     goto update_cleanup;

  133615.   }

  133616. #endif

  133617. 

  133618.   /* Jump to labelBreak to abandon further processing of this UPDATE */

  133619.   labelContinue = labelBreak = sqlite3VdbeMakeLabel(pParse);

  133620. 

  133621.   /* Not an UPSERT.  Normal processing.  Begin by

  133622.   ** initialize the count of updated rows */

  133623.   if( (db->flags&SQLITE_CountRows)!=0

  133624.    && !pParse->pTriggerTab

  133625.    && !pParse->nested

  133626.    && pUpsert==0

  133627.   ){

  133628.     regRowCount = ++pParse->nMem;

  133629.     sqlite3VdbeAddOp2(v, OP_Integer, 0, regRowCount);

  133630.   }

  133631. 

  133632.   if( HasRowid(pTab) ){

  133633.     sqlite3VdbeAddOp3(v, OP_Null, 0, regRowSet, regOldRowid);

  133634.   }else{

  133635.     assert( pPk!=0 );

  133636.     nPk = pPk->nKeyCol;

  133637.     iPk = pParse->nMem+1;

  133638.     pParse->nMem += nPk;

  133639.     regKey = ++pParse->nMem;

  133640.     if( pUpsert==0 ){

  133641.       iEph = pParse->nTab++;

  133642.         sqlite3VdbeAddOp3(v, OP_Null, 0, iPk, iPk+nPk-1);

  133643.       addrOpen = sqlite3VdbeAddOp2(v, OP_OpenEphemeral, iEph, nPk);

  133644.       sqlite3VdbeSetP4KeyInfo(pParse, pPk);

  133645.     }

  133646.   }

  133647.   

  133648.   if( pUpsert ){

  133649.     /* If this is an UPSERT, then all cursors have already been opened by

  133650.     ** the outer INSERT and the data cursor should be pointing at the row

  133651.     ** that is to be updated.  So bypass the code that searches for the

  133652.     ** row(s) to be updated.

  133653.     */

  133654.     pWInfo = 0;

  133655.     eOnePass = ONEPASS_SINGLE;

  133656.     sqlite3ExprIfFalse(pParse, pWhere, labelBreak, SQLITE_JUMPIFNULL);

  133657.   }else{

  133658.     /* Begin the database scan. 

  133659.     **

  133660.     ** Do not consider a single-pass strategy for a multi-row update if

  133661.     ** there are any triggers or foreign keys to process, or rows may

  133662.     ** be deleted as a result of REPLACE conflict handling. Any of these

  133663.     ** things might disturb a cursor being used to scan through the table

  133664.     ** or index, causing a single-pass approach to malfunction.  */

  133665.     flags = WHERE_ONEPASS_DESIRED|WHERE_SEEK_UNIQ_TABLE;

  133666.     if( !pParse->nested && !pTrigger && !hasFK && !chngKey && !bReplace ){

  133667.       flags |= WHERE_ONEPASS_MULTIROW;

  133668.     }

  133669.     pWInfo = sqlite3WhereBegin(pParse, pTabList, pWhere, 0, 0, flags, iIdxCur);

  133670.     if( pWInfo==0 ) goto update_cleanup;

  133671.   

  133672.     /* A one-pass strategy that might update more than one row may not

  133673.     ** be used if any column of the index used for the scan is being

  133674.     ** updated. Otherwise, if there is an index on "b", statements like

  133675.     ** the following could create an infinite loop:

  133676.     **

  133677.     **   UPDATE t1 SET b=b+1 WHERE b>?

  133678.     **

  133679.     ** Fall back to ONEPASS_OFF if where.c has selected a ONEPASS_MULTI

  133680.     ** strategy that uses an index for which one or more columns are being

  133681.     ** updated.  */

  133682.     eOnePass = sqlite3WhereOkOnePass(pWInfo, aiCurOnePass);

  133683.     if( eOnePass!=ONEPASS_SINGLE ){

  133684.       sqlite3MultiWrite(pParse);

  133685.       if( eOnePass==ONEPASS_MULTI ){

  133686.         int iCur = aiCurOnePass[1];

  133687.         if( iCur>=0 && iCur!=iDataCur && aToOpen[iCur-iBaseCur] ){

  133688.           eOnePass = ONEPASS_OFF;

  133689.         }

  133690.         assert( iCur!=iDataCur || !HasRowid(pTab) );

  133691.       }

  133692.     }

  133693.   }

  133694. 

  133695.   if( HasRowid(pTab) ){

  133696.     /* Read the rowid of the current row of the WHERE scan. In ONEPASS_OFF

  133697.     ** mode, write the rowid into the FIFO. In either of the one-pass modes,

  133698.     ** leave it in register regOldRowid.  */

  133699.     sqlite3VdbeAddOp2(v, OP_Rowid, iDataCur, regOldRowid);

  133700.     if( eOnePass==ONEPASS_OFF ){

  133701.       /* We need to use regRowSet, so reallocate aRegIdx[nAllIdx] */

  133702.       aRegIdx[nAllIdx] = ++pParse->nMem;

  133703.       sqlite3VdbeAddOp2(v, OP_RowSetAdd, regRowSet, regOldRowid);

  133704.     }

  133705.   }else{

  133706.     /* Read the PK of the current row into an array of registers. In

  133707.     ** ONEPASS_OFF mode, serialize the array into a record and store it in

  133708.     ** the ephemeral table. Or, in ONEPASS_SINGLE or MULTI mode, change

  133709.     ** the OP_OpenEphemeral instruction to a Noop (the ephemeral table 

  133710.     ** is not required) and leave the PK fields in the array of registers.  */

  133711.     for(i=0; i<nPk; i++){

  133712.       assert( pPk->aiColumn[i]>=0 );

  133713.       sqlite3ExprCodeGetColumnOfTable(v, pTab, iDataCur,pPk->aiColumn[i],iPk+i);

  133714.     }

  133715.     if( eOnePass ){

  133716.       if( addrOpen ) sqlite3VdbeChangeToNoop(v, addrOpen);

  133717.       nKey = nPk;

  133718.       regKey = iPk;

  133719.     }else{

  133720.       sqlite3VdbeAddOp4(v, OP_MakeRecord, iPk, nPk, regKey,

  133721.                         sqlite3IndexAffinityStr(db, pPk), nPk);

  133722.       sqlite3VdbeAddOp4Int(v, OP_IdxInsert, iEph, regKey, iPk, nPk);

  133723.     }

  133724.   }

  133725. 

  133726.   if( pUpsert==0 ){

  133727.     if( eOnePass!=ONEPASS_MULTI ){

  133728.       sqlite3WhereEnd(pWInfo);

  133729.     }

  133730.   

  133731.     if( !isView ){

  133732.       int addrOnce = 0;

  133733.   

  133734.       /* Open every index that needs updating. */

  133735.       if( eOnePass!=ONEPASS_OFF ){

  133736.         if( aiCurOnePass[0]>=0 ) aToOpen[aiCurOnePass[0]-iBaseCur] = 0;

  133737.         if( aiCurOnePass[1]>=0 ) aToOpen[aiCurOnePass[1]-iBaseCur] = 0;

  133738.       }

  133739.   

  133740.       if( eOnePass==ONEPASS_MULTI && (nIdx-(aiCurOnePass[1]>=0))>0 ){

  133741.         addrOnce = sqlite3VdbeAddOp0(v, OP_Once); VdbeCoverage(v);

  133742.       }

  133743.       sqlite3OpenTableAndIndices(pParse, pTab, OP_OpenWrite, 0, iBaseCur,

  133744.                                  aToOpen, 0, 0);

  133745.       if( addrOnce ) sqlite3VdbeJumpHere(v, addrOnce);

  133746.     }

  133747.   

  133748.     /* Top of the update loop */

  133749.     if( eOnePass!=ONEPASS_OFF ){

  133750.       if( !isView && aiCurOnePass[0]!=iDataCur && aiCurOnePass[1]!=iDataCur ){

  133751.         assert( pPk );

  133752.         sqlite3VdbeAddOp4Int(v, OP_NotFound, iDataCur, labelBreak, regKey,nKey);

  133753.         VdbeCoverage(v);

  133754.       }

  133755.       if( eOnePass!=ONEPASS_SINGLE ){

  133756.         labelContinue = sqlite3VdbeMakeLabel(pParse);

  133757.       }

  133758.       sqlite3VdbeAddOp2(v, OP_IsNull, pPk ? regKey : regOldRowid, labelBreak);

  133759.       VdbeCoverageIf(v, pPk==0);

  133760.       VdbeCoverageIf(v, pPk!=0);

  133761.     }else if( pPk ){

  133762.       labelContinue = sqlite3VdbeMakeLabel(pParse);

  133763.       sqlite3VdbeAddOp2(v, OP_Rewind, iEph, labelBreak); VdbeCoverage(v);

  133764.       addrTop = sqlite3VdbeAddOp2(v, OP_RowData, iEph, regKey);

  133765.       sqlite3VdbeAddOp4Int(v, OP_NotFound, iDataCur, labelContinue, regKey, 0);

  133766.       VdbeCoverage(v);

  133767.     }else{

  133768.       labelContinue = sqlite3VdbeAddOp3(v, OP_RowSetRead, regRowSet,labelBreak,

  133769.                                regOldRowid);

  133770.       VdbeCoverage(v);

  133771.       sqlite3VdbeAddOp3(v, OP_NotExists, iDataCur, labelContinue, regOldRowid);

  133772.       VdbeCoverage(v);

  133773.     }

  133774.   }

  133775. 

  133776.   /* If the rowid value will change, set register regNewRowid to

  133777.   ** contain the new value. If the rowid is not being modified,

  133778.   ** then regNewRowid is the same register as regOldRowid, which is

  133779.   ** already populated.  */

  133780.   assert( chngKey || pTrigger || hasFK || regOldRowid==regNewRowid );

  133781.   if( chngRowid ){

  133782.     sqlite3ExprCode(pParse, pRowidExpr, regNewRowid);

  133783.     sqlite3VdbeAddOp1(v, OP_MustBeInt, regNewRowid); VdbeCoverage(v);

  133784.   }

  133785. 

  133786.   /* Compute the old pre-UPDATE content of the row being changed, if that

  133787.   ** information is needed */

  133788.   if( chngPk || hasFK || pTrigger ){

  133789.     u32 oldmask = (hasFK ? sqlite3FkOldmask(pParse, pTab) : 0);

  133790.     oldmask |= sqlite3TriggerColmask(pParse, 

  133791.         pTrigger, pChanges, 0, TRIGGER_BEFORE|TRIGGER_AFTER, pTab, onError

  133792.     );

  133793.     for(i=0; i<pTab->nCol; i++){

  133794.       if( oldmask==0xffffffff

  133795.        || (i<32 && (oldmask & MASKBIT32(i))!=0)

  133796.        || (pTab->aCol[i].colFlags & COLFLAG_PRIMKEY)!=0

  133797.       ){

  133798.         testcase(  oldmask!=0xffffffff && i==31 );

  133799.         sqlite3ExprCodeGetColumnOfTable(v, pTab, iDataCur, i, regOld+i);

  133800.       }else{

  133801.         sqlite3VdbeAddOp2(v, OP_Null, 0, regOld+i);

  133802.       }

  133803.     }

  133804.     if( chngRowid==0 && pPk==0 ){

  133805.       sqlite3VdbeAddOp2(v, OP_Copy, regOldRowid, regNewRowid);

  133806.     }

  133807.   }

  133808. 

  133809.   /* Populate the array of registers beginning at regNew with the new

  133810.   ** row data. This array is used to check constants, create the new

  133811.   ** table and index records, and as the values for any new.* references

  133812.   ** made by triggers.

  133813.   **

  133814.   ** If there are one or more BEFORE triggers, then do not populate the

  133815.   ** registers associated with columns that are (a) not modified by

  133816.   ** this UPDATE statement and (b) not accessed by new.* references. The

  133817.   ** values for registers not modified by the UPDATE must be reloaded from 

  133818.   ** the database after the BEFORE triggers are fired anyway (as the trigger 

  133819.   ** may have modified them). So not loading those that are not going to

  133820.   ** be used eliminates some redundant opcodes.

  133821.   */

  133822.   newmask = sqlite3TriggerColmask(

  133823.       pParse, pTrigger, pChanges, 1, TRIGGER_BEFORE, pTab, onError

  133824.   );

  133825.   for(i=0; i<pTab->nCol; i++){

  133826.     if( i==pTab->iPKey ){

  133827.       sqlite3VdbeAddOp2(v, OP_Null, 0, regNew+i);

  133828.     }else{

  133829.       j = aXRef[i];

  133830.       if( j>=0 ){

  133831.         sqlite3ExprCode(pParse, pChanges->a[j].pExpr, regNew+i);

  133832.       }else if( 0==(tmask&TRIGGER_BEFORE) || i>31 || (newmask & MASKBIT32(i)) ){

  133833.         /* This branch loads the value of a column that will not be changed 

  133834.         ** into a register. This is done if there are no BEFORE triggers, or

  133835.         ** if there are one or more BEFORE triggers that use this value via

  133836.         ** a new.* reference in a trigger program.

  133837.         */

  133838.         testcase( i==31 );

  133839.         testcase( i==32 );

  133840.         sqlite3ExprCodeGetColumnOfTable(v, pTab, iDataCur, i, regNew+i);

  133841.       }else{

  133842.         sqlite3VdbeAddOp2(v, OP_Null, 0, regNew+i);

  133843.       }

  133844.     }

  133845.   }

  133846. 

  133847.   /* Fire any BEFORE UPDATE triggers. This happens before constraints are

  133848.   ** verified. One could argue that this is wrong.

  133849.   */

  133850.   if( tmask&TRIGGER_BEFORE ){

  133851.     sqlite3TableAffinity(v, pTab, regNew);

  133852.     sqlite3CodeRowTrigger(pParse, pTrigger, TK_UPDATE, pChanges, 

  133853.         TRIGGER_BEFORE, pTab, regOldRowid, onError, labelContinue);

  133854. 

  133855.     /* The row-trigger may have deleted the row being updated. In this

  133856.     ** case, jump to the next row. No updates or AFTER triggers are 

  133857.     ** required. This behavior - what happens when the row being updated

  133858.     ** is deleted or renamed by a BEFORE trigger - is left undefined in the

  133859.     ** documentation.

  133860.     */

  133861.     if( pPk ){

  133862.       sqlite3VdbeAddOp4Int(v, OP_NotFound, iDataCur, labelContinue,regKey,nKey);

  133863.       VdbeCoverage(v);

  133864.     }else{

  133865.       sqlite3VdbeAddOp3(v, OP_NotExists, iDataCur, labelContinue, regOldRowid);

  133866.       VdbeCoverage(v);

  133867.     }

  133868. 

  133869.     /* After-BEFORE-trigger-reload-loop:

  133870.     ** If it did not delete it, the BEFORE trigger may still have modified 

  133871.     ** some of the columns of the row being updated. Load the values for 

  133872.     ** all columns not modified by the update statement into their registers

  133873.     ** in case this has happened. Only unmodified columns are reloaded.

  133874.     ** The values computed for modified columns use the values before the

  133875.     ** BEFORE trigger runs.  See test case trigger1-18.0 (added 2018-04-26)

  133876.     ** for an example.

  133877.     */

  133878.     for(i=0; i<pTab->nCol; i++){

  133879.       if( aXRef[i]<0 && i!=pTab->iPKey ){

  133880.         sqlite3ExprCodeGetColumnOfTable(v, pTab, iDataCur, i, regNew+i);

  133881.       }

  133882.     }

  133883.   }

  133884. 

  133885.   if( !isView ){

  133886.     int addr1 = 0;        /* Address of jump instruction */

  133887. 

  133888.     /* Do constraint checks. */

  133889.     assert( regOldRowid>0 );

  133890.     sqlite3GenerateConstraintChecks(pParse, pTab, aRegIdx, iDataCur, iIdxCur,

  133891.         regNewRowid, regOldRowid, chngKey, onError, labelContinue, &bReplace,

  133892.         aXRef, 0);

  133893. 

  133894.     /* Do FK constraint checks. */

  133895.     if( hasFK ){

  133896.       sqlite3FkCheck(pParse, pTab, regOldRowid, 0, aXRef, chngKey);

  133897.     }

  133898. 

  133899.     /* Delete the index entries associated with the current record.  */

  133900.     if( bReplace || chngKey ){

  133901.       if( pPk ){

  133902.         addr1 = sqlite3VdbeAddOp4Int(v, OP_NotFound, iDataCur, 0, regKey, nKey);

  133903.       }else{

  133904.         addr1 = sqlite3VdbeAddOp3(v, OP_NotExists, iDataCur, 0, regOldRowid);

  133905.       }

  133906.       VdbeCoverageNeverTaken(v);

  133907.     }

  133908.     sqlite3GenerateRowIndexDelete(pParse, pTab, iDataCur, iIdxCur, aRegIdx, -1);

  133909. 

  133910.     /* If changing the rowid value, or if there are foreign key constraints

  133911.     ** to process, delete the old record. Otherwise, add a noop OP_Delete

  133912.     ** to invoke the pre-update hook.

  133913.     **

  133914.     ** That (regNew==regnewRowid+1) is true is also important for the 

  133915.     ** pre-update hook. If the caller invokes preupdate_new(), the returned

  133916.     ** value is copied from memory cell (regNewRowid+1+iCol), where iCol

  133917.     ** is the column index supplied by the user.

  133918.     */

  133919.     assert( regNew==regNewRowid+1 );

  133920. #ifdef SQLITE_ENABLE_PREUPDATE_HOOK

  133921.     sqlite3VdbeAddOp3(v, OP_Delete, iDataCur,

  133922.         OPFLAG_ISUPDATE | ((hasFK>1 || chngKey) ? 0 : OPFLAG_ISNOOP),

  133923.         regNewRowid

  133924.     );

  133925.     if( eOnePass==ONEPASS_MULTI ){

  133926.       assert( hasFK==0 && chngKey==0 );

  133927.       sqlite3VdbeChangeP5(v, OPFLAG_SAVEPOSITION);

  133928.     }

  133929.     if( !pParse->nested ){

  133930.       sqlite3VdbeAppendP4(v, pTab, P4_TABLE);

  133931.     }

  133932. #else

  133933.     if( hasFK>1 || chngKey ){

  133934.       sqlite3VdbeAddOp2(v, OP_Delete, iDataCur, 0);

  133935.     }

  133936. #endif

  133937.     if( bReplace || chngKey ){

  133938.       sqlite3VdbeJumpHere(v, addr1);

  133939.     }

  133940. 

  133941.     if( hasFK ){

  133942.       sqlite3FkCheck(pParse, pTab, 0, regNewRowid, aXRef, chngKey);

  133943.     }

  133944.   

  133945.     /* Insert the new index entries and the new record. */

  133946.     sqlite3CompleteInsertion(

  133947.         pParse, pTab, iDataCur, iIdxCur, regNewRowid, aRegIdx, 

  133948.         OPFLAG_ISUPDATE | (eOnePass==ONEPASS_MULTI ? OPFLAG_SAVEPOSITION : 0), 

  133949.         0, 0

  133950.     );

  133951. 

  133952.     /* Do any ON CASCADE, SET NULL or SET DEFAULT operations required to

  133953.     ** handle rows (possibly in other tables) that refer via a foreign key

  133954.     ** to the row just updated. */ 

  133955.     if( hasFK ){

  133956.       sqlite3FkActions(pParse, pTab, pChanges, regOldRowid, aXRef, chngKey);

  133957.     }

  133958.   }

  133959. 

  133960.   /* Increment the row counter 

  133961.   */

  133962.   if( regRowCount ){

  133963.     sqlite3VdbeAddOp2(v, OP_AddImm, regRowCount, 1);

  133964.   }

  133965. 

  133966.   sqlite3CodeRowTrigger(pParse, pTrigger, TK_UPDATE, pChanges, 

  133967.       TRIGGER_AFTER, pTab, regOldRowid, onError, labelContinue);

  133968. 

  133969.   /* Repeat the above with the next record to be updated, until

  133970.   ** all record selected by the WHERE clause have been updated.

  133971.   */

  133972.   if( eOnePass==ONEPASS_SINGLE ){

  133973.     /* Nothing to do at end-of-loop for a single-pass */

  133974.   }else if( eOnePass==ONEPASS_MULTI ){

  133975.     sqlite3VdbeResolveLabel(v, labelContinue);

  133976.     sqlite3WhereEnd(pWInfo);

  133977.   }else if( pPk ){

  133978.     sqlite3VdbeResolveLabel(v, labelContinue);

  133979.     sqlite3VdbeAddOp2(v, OP_Next, iEph, addrTop); VdbeCoverage(v);

  133980.   }else{

  133981.     sqlite3VdbeGoto(v, labelContinue);

  133982.   }

  133983.   sqlite3VdbeResolveLabel(v, labelBreak);

  133984. 

  133985.   /* Update the sqlite_sequence table by storing the content of the

  133986.   ** maximum rowid counter values recorded while inserting into

  133987.   ** autoincrement tables.

  133988.   */

  133989.   if( pParse->nested==0 && pParse->pTriggerTab==0 && pUpsert==0 ){

  133990.     sqlite3AutoincrementEnd(pParse);

  133991.   }

  133992. 

  133993.   /*

  133994.   ** Return the number of rows that were changed, if we are tracking

  133995.   ** that information.

  133996.   */

  133997.   if( regRowCount ){

  133998.     sqlite3VdbeAddOp2(v, OP_ResultRow, regRowCount, 1);

  133999.     sqlite3VdbeSetNumCols(v, 1);

  134000.     sqlite3VdbeSetColName(v, 0, COLNAME_NAME, "rows updated", SQLITE_STATIC);

  134001.   }

  134002. 

  134003. update_cleanup:

  134004.   sqlite3AuthContextPop(&sContext);

  134005.   sqlite3DbFree(db, aXRef); /* Also frees aRegIdx[] and aToOpen[] */

  134006.   sqlite3SrcListDelete(db, pTabList);

  134007.   sqlite3ExprListDelete(db, pChanges);

  134008.   sqlite3ExprDelete(db, pWhere);

  134009. #if defined(SQLITE_ENABLE_UPDATE_DELETE_LIMIT) 

  134010.   sqlite3ExprListDelete(db, pOrderBy);

  134011.   sqlite3ExprDelete(db, pLimit);

  134012. #endif

  134013.   return;

  134014. }

  134015. /* Make sure "isView" and other macros defined above are undefined. Otherwise

  134016. ** they may interfere with compilation of other functions in this file

  134017. ** (or in another file, if this file becomes part of the amalgamation).  */

  134018. #ifdef isView

  134019.  #undef isView

  134020. #endif

  134021. #ifdef pTrigger

  134022.  #undef pTrigger

  134023. #endif

  134024. 

  134025. #ifndef SQLITE_OMIT_VIRTUALTABLE

  134026. /*

  134027. ** Generate code for an UPDATE of a virtual table.

  134028. **

  134029. ** There are two possible strategies - the default and the special 

  134030. ** "onepass" strategy. Onepass is only used if the virtual table 

  134031. ** implementation indicates that pWhere may match at most one row.

  134032. **

  134033. ** The default strategy is to create an ephemeral table that contains

  134034. ** for each row to be changed:

  134035. **

  134036. **   (A)  The original rowid of that row.

  134037. **   (B)  The revised rowid for the row.

  134038. **   (C)  The content of every column in the row.

  134039. **

  134040. ** Then loop through the contents of this ephemeral table executing a

  134041. ** VUpdate for each row. When finished, drop the ephemeral table.

  134042. **

  134043. ** The "onepass" strategy does not use an ephemeral table. Instead, it

  134044. ** stores the same values (A, B and C above) in a register array and

  134045. ** makes a single invocation of VUpdate.

  134046. */

  134047. static void updateVirtualTable(

  134048.   Parse *pParse,       /* The parsing context */

  134049.   SrcList *pSrc,       /* The virtual table to be modified */

  134050.   Table *pTab,         /* The virtual table */

  134051.   ExprList *pChanges,  /* The columns to change in the UPDATE statement */

  134052.   Expr *pRowid,        /* Expression used to recompute the rowid */

  134053.   int *aXRef,          /* Mapping from columns of pTab to entries in pChanges */

  134054.   Expr *pWhere,        /* WHERE clause of the UPDATE statement */

  134055.   int onError          /* ON CONFLICT strategy */

  134056. ){

  134057.   Vdbe *v = pParse->pVdbe;  /* Virtual machine under construction */

  134058.   int ephemTab;             /* Table holding the result of the SELECT */

  134059.   int i;                    /* Loop counter */

  134060.   sqlite3 *db = pParse->db; /* Database connection */

  134061.   const char *pVTab = (const char*)sqlite3GetVTable(db, pTab);

  134062.   WhereInfo *pWInfo;

  134063.   int nArg = 2 + pTab->nCol;      /* Number of arguments to VUpdate */

  134064.   int regArg;                     /* First register in VUpdate arg array */

  134065.   int regRec;                     /* Register in which to assemble record */

  134066.   int regRowid;                   /* Register for ephem table rowid */

  134067.   int iCsr = pSrc->a[0].iCursor;  /* Cursor used for virtual table scan */

  134068.   int aDummy[2];                  /* Unused arg for sqlite3WhereOkOnePass() */

  134069.   int eOnePass;                   /* True to use onepass strategy */

  134070.   int addr;                       /* Address of OP_OpenEphemeral */

  134071. 

  134072.   /* Allocate nArg registers in which to gather the arguments for VUpdate. Then

  134073.   ** create and open the ephemeral table in which the records created from

  134074.   ** these arguments will be temporarily stored. */

  134075.   assert( v );

  134076.   ephemTab = pParse->nTab++;

  134077.   addr= sqlite3VdbeAddOp2(v, OP_OpenEphemeral, ephemTab, nArg);

  134078.   regArg = pParse->nMem + 1;

  134079.   pParse->nMem += nArg;

  134080.   regRec = ++pParse->nMem;

  134081.   regRowid = ++pParse->nMem;

  134082. 

  134083.   /* Start scanning the virtual table */

  134084.   pWInfo = sqlite3WhereBegin(pParse, pSrc, pWhere, 0,0,WHERE_ONEPASS_DESIRED,0);

  134085.   if( pWInfo==0 ) return;

  134086. 

  134087.   /* Populate the argument registers. */

  134088.   for(i=0; i<pTab->nCol; i++){

  134089.     if( aXRef[i]>=0 ){

  134090.       sqlite3ExprCode(pParse, pChanges->a[aXRef[i]].pExpr, regArg+2+i);

  134091.     }else{

  134092.       sqlite3VdbeAddOp3(v, OP_VColumn, iCsr, i, regArg+2+i);

  134093.       sqlite3VdbeChangeP5(v, OPFLAG_NOCHNG);/* Enable sqlite3_vtab_nochange() */

  134094.     }

  134095.   }

  134096.   if( HasRowid(pTab) ){

  134097.     sqlite3VdbeAddOp2(v, OP_Rowid, iCsr, regArg);

  134098.     if( pRowid ){

  134099.       sqlite3ExprCode(pParse, pRowid, regArg+1);

  134100.     }else{

  134101.       sqlite3VdbeAddOp2(v, OP_Rowid, iCsr, regArg+1);

  134102.     }

  134103.   }else{

  134104.     Index *pPk;   /* PRIMARY KEY index */

  134105.     i16 iPk;      /* PRIMARY KEY column */

  134106.     pPk = sqlite3PrimaryKeyIndex(pTab);

  134107.     assert( pPk!=0 );

  134108.     assert( pPk->nKeyCol==1 );

  134109.     iPk = pPk->aiColumn[0];

  134110.     sqlite3VdbeAddOp3(v, OP_VColumn, iCsr, iPk, regArg);

  134111.     sqlite3VdbeAddOp2(v, OP_SCopy, regArg+2+iPk, regArg+1);

  134112.   }

  134113. 

  134114.   eOnePass = sqlite3WhereOkOnePass(pWInfo, aDummy);

  134115. 

  134116.   /* There is no ONEPASS_MULTI on virtual tables */

  134117.   assert( eOnePass==ONEPASS_OFF || eOnePass==ONEPASS_SINGLE );

  134118. 

  134119.   if( eOnePass ){

  134120.     /* If using the onepass strategy, no-op out the OP_OpenEphemeral coded

  134121.     ** above. */

  134122.     sqlite3VdbeChangeToNoop(v, addr);

  134123.     sqlite3VdbeAddOp1(v, OP_Close, iCsr);

  134124.   }else{

  134125.     /* Create a record from the argument register contents and insert it into

  134126.     ** the ephemeral table. */

  134127.     sqlite3MultiWrite(pParse);

  134128.     sqlite3VdbeAddOp3(v, OP_MakeRecord, regArg, nArg, regRec);

  134129. #ifdef SQLITE_DEBUG

  134130.     /* Signal an assert() within OP_MakeRecord that it is allowed to

  134131.     ** accept no-change records with serial_type 10 */

  134132.     sqlite3VdbeChangeP5(v, OPFLAG_NOCHNG_MAGIC);

  134133. #endif

  134134.     sqlite3VdbeAddOp2(v, OP_NewRowid, ephemTab, regRowid);

  134135.     sqlite3VdbeAddOp3(v, OP_Insert, ephemTab, regRec, regRowid);

  134136.   }

  134137. 

  134138. 

  134139.   if( eOnePass==ONEPASS_OFF ){

  134140.     /* End the virtual table scan */

  134141.     sqlite3WhereEnd(pWInfo);

  134142. 

  134143.     /* Begin scannning through the ephemeral table. */

  134144.     addr = sqlite3VdbeAddOp1(v, OP_Rewind, ephemTab); VdbeCoverage(v);

  134145. 

  134146.     /* Extract arguments from the current row of the ephemeral table and 

  134147.     ** invoke the VUpdate method.  */

  134148.     for(i=0; i<nArg; i++){

  134149.       sqlite3VdbeAddOp3(v, OP_Column, ephemTab, i, regArg+i);

  134150.     }

  134151.   }

  134152.   sqlite3VtabMakeWritable(pParse, pTab);

  134153.   sqlite3VdbeAddOp4(v, OP_VUpdate, 0, nArg, regArg, pVTab, P4_VTAB);

  134154.   sqlite3VdbeChangeP5(v, onError==OE_Default ? OE_Abort : onError);

  134155.   sqlite3MayAbort(pParse);

  134156. 

  134157.   /* End of the ephemeral table scan. Or, if using the onepass strategy,

  134158.   ** jump to here if the scan visited zero rows. */

  134159.   if( eOnePass==ONEPASS_OFF ){

  134160.     sqlite3VdbeAddOp2(v, OP_Next, ephemTab, addr+1); VdbeCoverage(v);

  134161.     sqlite3VdbeJumpHere(v, addr);

  134162.     sqlite3VdbeAddOp2(v, OP_Close, ephemTab, 0);

  134163.   }else{

  134164.     sqlite3WhereEnd(pWInfo);

  134165.   }

  134166. }

  134167. #endif /* SQLITE_OMIT_VIRTUALTABLE */

  134168. 

  134169. /************** End of update.c **********************************************/

  134170. /************** Begin file upsert.c ******************************************/

  134171. /*

  134172. ** 2018-04-12

  134173. **

  134174. ** The author disclaims copyright to this source code.  In place of

  134175. ** a legal notice, here is a blessing:

  134176. **

  134177. **    May you do good and not evil.

  134178. **    May you find forgiveness for yourself and forgive others.

  134179. **    May you share freely, never taking more than you give.

  134180. **

  134181. *************************************************************************

  134182. ** This file contains code to implement various aspects of UPSERT

  134183. ** processing and handling of the Upsert object.

  134184. */

  134185. /* #include "sqliteInt.h" */

  134186. 

  134187. #ifndef SQLITE_OMIT_UPSERT

  134188. /*

  134189. ** Free a list of Upsert objects

  134190. */

  134191. SQLITE_PRIVATE void sqlite3UpsertDelete(sqlite3 *db, Upsert *p){

  134192.   if( p ){

  134193.     sqlite3ExprListDelete(db, p->pUpsertTarget);

  134194.     sqlite3ExprDelete(db, p->pUpsertTargetWhere);

  134195.     sqlite3ExprListDelete(db, p->pUpsertSet);

  134196.     sqlite3ExprDelete(db, p->pUpsertWhere);

  134197.     sqlite3DbFree(db, p);

  134198.   }

  134199. }

  134200. 

  134201. /*

  134202. ** Duplicate an Upsert object.

  134203. */

  134204. SQLITE_PRIVATE Upsert *sqlite3UpsertDup(sqlite3 *db, Upsert *p){

  134205.   if( p==0 ) return 0;

  134206.   return sqlite3UpsertNew(db,

  134207.            sqlite3ExprListDup(db, p->pUpsertTarget, 0),

  134208.            sqlite3ExprDup(db, p->pUpsertTargetWhere, 0),

  134209.            sqlite3ExprListDup(db, p->pUpsertSet, 0),

  134210.            sqlite3ExprDup(db, p->pUpsertWhere, 0)

  134211.          );

  134212. }

  134213. 

  134214. /*

  134215. ** Create a new Upsert object.

  134216. */

  134217. SQLITE_PRIVATE Upsert *sqlite3UpsertNew(

  134218.   sqlite3 *db,           /* Determines which memory allocator to use */

  134219.   ExprList *pTarget,     /* Target argument to ON CONFLICT, or NULL */

  134220.   Expr *pTargetWhere,    /* Optional WHERE clause on the target */

  134221.   ExprList *pSet,        /* UPDATE columns, or NULL for a DO NOTHING */

  134222.   Expr *pWhere           /* WHERE clause for the ON CONFLICT UPDATE */

  134223. ){

  134224.   Upsert *pNew;

  134225.   pNew = sqlite3DbMallocRaw(db, sizeof(Upsert));

  134226.   if( pNew==0 ){

  134227.     sqlite3ExprListDelete(db, pTarget);

  134228.     sqlite3ExprDelete(db, pTargetWhere);

  134229.     sqlite3ExprListDelete(db, pSet);

  134230.     sqlite3ExprDelete(db, pWhere);

  134231.     return 0;

  134232.   }else{

  134233.     pNew->pUpsertTarget = pTarget;

  134234.     pNew->pUpsertTargetWhere = pTargetWhere;

  134235.     pNew->pUpsertSet = pSet;

  134236.     pNew->pUpsertWhere = pWhere;

  134237.     pNew->pUpsertIdx = 0;

  134238.   }

  134239.   return pNew;

  134240. }

  134241. 

  134242. /*

  134243. ** Analyze the ON CONFLICT clause described by pUpsert.  Resolve all

  134244. ** symbols in the conflict-target.

  134245. **

  134246. ** Return SQLITE_OK if everything works, or an error code is something

  134247. ** is wrong.

  134248. */

  134249. SQLITE_PRIVATE int sqlite3UpsertAnalyzeTarget(

  134250.   Parse *pParse,     /* The parsing context */

  134251.   SrcList *pTabList, /* Table into which we are inserting */

  134252.   Upsert *pUpsert    /* The ON CONFLICT clauses */

  134253. ){

  134254.   Table *pTab;            /* That table into which we are inserting */

  134255.   int rc;                 /* Result code */

  134256.   int iCursor;            /* Cursor used by pTab */

  134257.   Index *pIdx;            /* One of the indexes of pTab */

  134258.   ExprList *pTarget;      /* The conflict-target clause */

  134259.   Expr *pTerm;            /* One term of the conflict-target clause */

  134260.   NameContext sNC;        /* Context for resolving symbolic names */

  134261.   Expr sCol[2];           /* Index column converted into an Expr */

  134262. 

  134263.   assert( pTabList->nSrc==1 );

  134264.   assert( pTabList->a[0].pTab!=0 );

  134265.   assert( pUpsert!=0 );

  134266.   assert( pUpsert->pUpsertTarget!=0 );

  134267. 

  134268.   /* Resolve all symbolic names in the conflict-target clause, which

  134269.   ** includes both the list of columns and the optional partial-index

  134270.   ** WHERE clause.

  134271.   */

  134272.   memset(&sNC, 0, sizeof(sNC));

  134273.   sNC.pParse = pParse;

  134274.   sNC.pSrcList = pTabList;

  134275.   rc = sqlite3ResolveExprListNames(&sNC, pUpsert->pUpsertTarget);

  134276.   if( rc ) return rc;

  134277.   rc = sqlite3ResolveExprNames(&sNC, pUpsert->pUpsertTargetWhere);

  134278.   if( rc ) return rc;

  134279. 

  134280.   /* Check to see if the conflict target matches the rowid. */  

  134281.   pTab = pTabList->a[0].pTab;

  134282.   pTarget = pUpsert->pUpsertTarget;

  134283.   iCursor = pTabList->a[0].iCursor;

  134284.   if( HasRowid(pTab) 

  134285.    && pTarget->nExpr==1

  134286.    && (pTerm = pTarget->a[0].pExpr)->op==TK_COLUMN

  134287.    && pTerm->iColumn==XN_ROWID

  134288.   ){

  134289.     /* The conflict-target is the rowid of the primary table */

  134290.     assert( pUpsert->pUpsertIdx==0 );

  134291.     return SQLITE_OK;

  134292.   }

  134293. 

  134294.   /* Initialize sCol[0..1] to be an expression parse tree for a

  134295.   ** single column of an index.  The sCol[0] node will be the TK_COLLATE

  134296.   ** operator and sCol[1] will be the TK_COLUMN operator.  Code below

  134297.   ** will populate the specific collation and column number values

  134298.   ** prior to comparing against the conflict-target expression.

  134299.   */

  134300.   memset(sCol, 0, sizeof(sCol));

  134301.   sCol[0].op = TK_COLLATE;

  134302.   sCol[0].pLeft = &sCol[1];

  134303.   sCol[1].op = TK_COLUMN;

  134304.   sCol[1].iTable = pTabList->a[0].iCursor;

  134305. 

  134306.   /* Check for matches against other indexes */

  134307.   for(pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext){

  134308.     int ii, jj, nn;

  134309.     if( !IsUniqueIndex(pIdx) ) continue;

  134310.     if( pTarget->nExpr!=pIdx->nKeyCol ) continue;

  134311.     if( pIdx->pPartIdxWhere ){

  134312.       if( pUpsert->pUpsertTargetWhere==0 ) continue;

  134313.       if( sqlite3ExprCompare(pParse, pUpsert->pUpsertTargetWhere,

  134314.                              pIdx->pPartIdxWhere, iCursor)!=0 ){

  134315.         continue;

  134316.       }

  134317.     }

  134318.     nn = pIdx->nKeyCol;

  134319.     for(ii=0; ii<nn; ii++){

  134320.       Expr *pExpr;

  134321.       sCol[0].u.zToken = (char*)pIdx->azColl[ii];

  134322.       if( pIdx->aiColumn[ii]==XN_EXPR ){

  134323.         assert( pIdx->aColExpr!=0 );

  134324.         assert( pIdx->aColExpr->nExpr>ii );

  134325.         pExpr = pIdx->aColExpr->a[ii].pExpr;

  134326.         if( pExpr->op!=TK_COLLATE ){

  134327.           sCol[0].pLeft = pExpr;

  134328.           pExpr = &sCol[0];

  134329.         }

  134330.       }else{

  134331.         sCol[0].pLeft = &sCol[1];

  134332.         sCol[1].iColumn = pIdx->aiColumn[ii];

  134333.         pExpr = &sCol[0];

  134334.       }

  134335.       for(jj=0; jj<nn; jj++){

  134336.         if( sqlite3ExprCompare(pParse, pTarget->a[jj].pExpr, pExpr,iCursor)<2 ){

  134337.           break;  /* Column ii of the index matches column jj of target */

  134338.         }

  134339.       }

  134340.       if( jj>=nn ){

  134341.         /* The target contains no match for column jj of the index */

  134342.         break;

  134343.       }

  134344.     }

  134345.     if( ii<nn ){

  134346.       /* Column ii of the index did not match any term of the conflict target.

  134347.       ** Continue the search with the next index. */

  134348.       continue;

  134349.     }

  134350.     pUpsert->pUpsertIdx = pIdx;

  134351.     return SQLITE_OK;

  134352.   }

  134353.   sqlite3ErrorMsg(pParse, "ON CONFLICT clause does not match any "

  134354.                           "PRIMARY KEY or UNIQUE constraint");

  134355.   return SQLITE_ERROR;

  134356. }

  134357. 

  134358. /*

  134359. ** Generate bytecode that does an UPDATE as part of an upsert.

  134360. **

  134361. ** If pIdx is NULL, then the UNIQUE constraint that failed was the IPK.

  134362. ** In this case parameter iCur is a cursor open on the table b-tree that

  134363. ** currently points to the conflicting table row. Otherwise, if pIdx

  134364. ** is not NULL, then pIdx is the constraint that failed and iCur is a

  134365. ** cursor points to the conflicting row.

  134366. */

  134367. SQLITE_PRIVATE void sqlite3UpsertDoUpdate(

  134368.   Parse *pParse,        /* The parsing and code-generating context */

  134369.   Upsert *pUpsert,      /* The ON CONFLICT clause for the upsert */

  134370.   Table *pTab,          /* The table being updated */

  134371.   Index *pIdx,          /* The UNIQUE constraint that failed */

  134372.   int iCur              /* Cursor for pIdx (or pTab if pIdx==NULL) */

  134373. ){

  134374.   Vdbe *v = pParse->pVdbe;

  134375.   sqlite3 *db = pParse->db;

  134376.   SrcList *pSrc;            /* FROM clause for the UPDATE */

  134377.   int iDataCur;

  134378. 

  134379.   assert( v!=0 );

  134380.   assert( pUpsert!=0 );

  134381.   VdbeNoopComment((v, "Begin DO UPDATE of UPSERT"));

  134382.   iDataCur = pUpsert->iDataCur;

  134383.   if( pIdx && iCur!=iDataCur ){

  134384.     if( HasRowid(pTab) ){

  134385.       int regRowid = sqlite3GetTempReg(pParse);

  134386.       sqlite3VdbeAddOp2(v, OP_IdxRowid, iCur, regRowid);

  134387.       sqlite3VdbeAddOp3(v, OP_SeekRowid, iDataCur, 0, regRowid);

  134388.       VdbeCoverage(v);

  134389.       sqlite3ReleaseTempReg(pParse, regRowid);

  134390.     }else{

  134391.       Index *pPk = sqlite3PrimaryKeyIndex(pTab);

  134392.       int nPk = pPk->nKeyCol;

  134393.       int iPk = pParse->nMem+1;

  134394.       int i;

  134395.       pParse->nMem += nPk;

  134396.       for(i=0; i<nPk; i++){

  134397.         int k;

  134398.         assert( pPk->aiColumn[i]>=0 );

  134399.         k = sqlite3ColumnOfIndex(pIdx, pPk->aiColumn[i]);

  134400.         sqlite3VdbeAddOp3(v, OP_Column, iCur, k, iPk+i);

  134401.         VdbeComment((v, "%s.%s", pIdx->zName,

  134402.                     pTab->aCol[pPk->aiColumn[i]].zName));

  134403.       }

  134404.       sqlite3VdbeVerifyAbortable(v, OE_Abort);

  134405.       i = sqlite3VdbeAddOp4Int(v, OP_Found, iDataCur, 0, iPk, nPk);

  134406.       VdbeCoverage(v);

  134407.       sqlite3VdbeAddOp4(v, OP_Halt, SQLITE_CORRUPT, OE_Abort, 0, 

  134408.             "corrupt database", P4_STATIC);

  134409.       sqlite3VdbeJumpHere(v, i);

  134410.     }

  134411.   }

  134412.   /* pUpsert does not own pUpsertSrc - the outer INSERT statement does.  So

  134413.   ** we have to make a copy before passing it down into sqlite3Update() */

  134414.   pSrc = sqlite3SrcListDup(db, pUpsert->pUpsertSrc, 0);

  134415.   sqlite3Update(pParse, pSrc, pUpsert->pUpsertSet,

  134416.       pUpsert->pUpsertWhere, OE_Abort, 0, 0, pUpsert);

  134417.   pUpsert->pUpsertSet = 0;    /* Will have been deleted by sqlite3Update() */

  134418.   pUpsert->pUpsertWhere = 0;  /* Will have been deleted by sqlite3Update() */

  134419.   VdbeNoopComment((v, "End DO UPDATE of UPSERT"));

  134420. }

  134421. 

  134422. #endif /* SQLITE_OMIT_UPSERT */

  134423. 

  134424. /************** End of upsert.c **********************************************/

  134425. /************** Begin file vacuum.c ******************************************/

  134426. /*

  134427. ** 2003 April 6

  134428. **

  134429. ** The author disclaims copyright to this source code.  In place of

  134430. ** a legal notice, here is a blessing:

  134431. **

  134432. **    May you do good and not evil.

  134433. **    May you find forgiveness for yourself and forgive others.

  134434. **    May you share freely, never taking more than you give.

  134435. **

  134436. *************************************************************************

  134437. ** This file contains code used to implement the VACUUM command.

  134438. **

  134439. ** Most of the code in this file may be omitted by defining the

  134440. ** SQLITE_OMIT_VACUUM macro.

  134441. */

  134442. /* #include "sqliteInt.h" */

  134443. /* #include "vdbeInt.h" */

  134444. 

  134445. #if !defined(SQLITE_OMIT_VACUUM) && !defined(SQLITE_OMIT_ATTACH)

  134446. 

  134447. /*

  134448. ** Execute zSql on database db.

  134449. **

  134450. ** If zSql returns rows, then each row will have exactly one

  134451. ** column.  (This will only happen if zSql begins with "SELECT".)

  134452. ** Take each row of result and call execSql() again recursively.

  134453. **

  134454. ** The execSqlF() routine does the same thing, except it accepts

  134455. ** a format string as its third argument

  134456. */

  134457. static int execSql(sqlite3 *db, char **pzErrMsg, const char *zSql){

  134458.   sqlite3_stmt *pStmt;

  134459.   int rc;

  134460. 

  134461.   /* printf("SQL: [%s]\n", zSql); fflush(stdout); */

  134462.   rc = sqlite3_prepare_v2(db, zSql, -1, &pStmt, 0);

  134463.   if( rc!=SQLITE_OK ) return rc;

  134464.   while( SQLITE_ROW==(rc = sqlite3_step(pStmt)) ){

  134465.     const char *zSubSql = (const char*)sqlite3_column_text(pStmt,0);

  134466.     assert( sqlite3_strnicmp(zSql,"SELECT",6)==0 );

  134467.     /* The secondary SQL must be one of CREATE TABLE, CREATE INDEX,

  134468.     ** or INSERT.  Historically there have been attacks that first

  134469.     ** corrupt the sqlite_master.sql field with other kinds of statements

  134470.     ** then run VACUUM to get those statements to execute at inappropriate

  134471.     ** times. */

  134472.     if( zSubSql

  134473.      && (strncmp(zSubSql,"CRE",3)==0 || strncmp(zSubSql,"INS",3)==0)

  134474.     ){

  134475.       rc = execSql(db, pzErrMsg, zSubSql);

  134476.       if( rc!=SQLITE_OK ) break;

  134477.     }

  134478.   }

  134479.   assert( rc!=SQLITE_ROW );

  134480.   if( rc==SQLITE_DONE ) rc = SQLITE_OK;

  134481.   if( rc ){

  134482.     sqlite3SetString(pzErrMsg, db, sqlite3_errmsg(db));

  134483.   }

  134484.   (void)sqlite3_finalize(pStmt);

  134485.   return rc;

  134486. }

  134487. static int execSqlF(sqlite3 *db, char **pzErrMsg, const char *zSql, ...){

  134488.   char *z;

  134489.   va_list ap;

  134490.   int rc;

  134491.   va_start(ap, zSql);

  134492.   z = sqlite3VMPrintf(db, zSql, ap);

  134493.   va_end(ap);

  134494.   if( z==0 ) return SQLITE_NOMEM;

  134495.   rc = execSql(db, pzErrMsg, z);

  134496.   sqlite3DbFree(db, z);

  134497.   return rc;

  134498. }

  134499. 

  134500. /*

  134501. ** The VACUUM command is used to clean up the database,

  134502. ** collapse free space, etc.  It is modelled after the VACUUM command

  134503. ** in PostgreSQL.  The VACUUM command works as follows:

  134504. **

  134505. **   (1)  Create a new transient database file

  134506. **   (2)  Copy all content from the database being vacuumed into

  134507. **        the new transient database file

  134508. **   (3)  Copy content from the transient database back into the

  134509. **        original database.

  134510. **

  134511. ** The transient database requires temporary disk space approximately

  134512. ** equal to the size of the original database.  The copy operation of

  134513. ** step (3) requires additional temporary disk space approximately equal

  134514. ** to the size of the original database for the rollback journal.

  134515. ** Hence, temporary disk space that is approximately 2x the size of the

  134516. ** original database is required.  Every page of the database is written

  134517. ** approximately 3 times:  Once for step (2) and twice for step (3).

  134518. ** Two writes per page are required in step (3) because the original

  134519. ** database content must be written into the rollback journal prior to

  134520. ** overwriting the database with the vacuumed content.

  134521. **

  134522. ** Only 1x temporary space and only 1x writes would be required if

  134523. ** the copy of step (3) were replaced by deleting the original database

  134524. ** and renaming the transient database as the original.  But that will

  134525. ** not work if other processes are attached to the original database.

  134526. ** And a power loss in between deleting the original and renaming the

  134527. ** transient would cause the database file to appear to be deleted

  134528. ** following reboot.

  134529. */

  134530. SQLITE_PRIVATE void sqlite3Vacuum(Parse *pParse, Token *pNm, Expr *pInto){

  134531.   Vdbe *v = sqlite3GetVdbe(pParse);

  134532.   int iDb = 0;

  134533.   if( v==0 ) goto build_vacuum_end;

  134534.   if( pParse->nErr ) goto build_vacuum_end;

  134535.   if( pNm ){

  134536. #ifndef SQLITE_BUG_COMPATIBLE_20160819

  134537.     /* Default behavior:  Report an error if the argument to VACUUM is

  134538.     ** not recognized */

  134539.     iDb = sqlite3TwoPartName(pParse, pNm, pNm, &pNm);

  134540.     if( iDb<0 ) goto build_vacuum_end;

  134541. #else

  134542.     /* When SQLITE_BUG_COMPATIBLE_20160819 is defined, unrecognized arguments

  134543.     ** to VACUUM are silently ignored.  This is a back-out of a bug fix that

  134544.     ** occurred on 2016-08-19 (https://www.sqlite.org/src/info/083f9e6270).

  134545.     ** The buggy behavior is required for binary compatibility with some

  134546.     ** legacy applications. */

  134547.     iDb = sqlite3FindDb(pParse->db, pNm);

  134548.     if( iDb<0 ) iDb = 0;

  134549. #endif

  134550.   }

  134551.   if( iDb!=1 ){

  134552.     int iIntoReg = 0;

  134553.     if( pInto && sqlite3ResolveSelfReference(pParse,0,0,pInto,0)==0 ){

  134554.       iIntoReg = ++pParse->nMem;

  134555.       sqlite3ExprCode(pParse, pInto, iIntoReg);

  134556.     }

  134557.     sqlite3VdbeAddOp2(v, OP_Vacuum, iDb, iIntoReg);

  134558.     sqlite3VdbeUsesBtree(v, iDb);

  134559.   }

  134560. build_vacuum_end:

  134561.   sqlite3ExprDelete(pParse->db, pInto);

  134562.   return;

  134563. }

  134564. 

  134565. /*

  134566. ** This routine implements the OP_Vacuum opcode of the VDBE.

  134567. */

  134568. SQLITE_PRIVATE SQLITE_NOINLINE int sqlite3RunVacuum(

  134569.   char **pzErrMsg,        /* Write error message here */

  134570.   sqlite3 *db,            /* Database connection */

  134571.   int iDb,                /* Which attached DB to vacuum */

  134572.   sqlite3_value *pOut     /* Write results here, if not NULL. VACUUM INTO */

  134573. ){

  134574.   int rc = SQLITE_OK;     /* Return code from service routines */

  134575.   Btree *pMain;           /* The database being vacuumed */

  134576.   Btree *pTemp;           /* The temporary database we vacuum into */

  134577.   u32 saved_mDbFlags;     /* Saved value of db->mDbFlags */

  134578.   u64 saved_flags;        /* Saved value of db->flags */

  134579.   int saved_nChange;      /* Saved value of db->nChange */

  134580.   int saved_nTotalChange; /* Saved value of db->nTotalChange */

  134581.   u32 saved_openFlags;    /* Saved value of db->openFlags */

  134582.   u8 saved_mTrace;        /* Saved trace settings */

  134583.   Db *pDb = 0;            /* Database to detach at end of vacuum */

  134584.   int isMemDb;            /* True if vacuuming a :memory: database */

  134585.   int nRes;               /* Bytes of reserved space at the end of each page */

  134586.   int nDb;                /* Number of attached databases */

  134587.   const char *zDbMain;    /* Schema name of database to vacuum */

  134588.   const char *zOut;       /* Name of output file */

  134589. 

  134590.   if( !db->autoCommit ){

  134591.     sqlite3SetString(pzErrMsg, db, "cannot VACUUM from within a transaction");

  134592.     return SQLITE_ERROR; /* IMP: R-12218-18073 */

  134593.   }

  134594.   if( db->nVdbeActive>1 ){

  134595.     sqlite3SetString(pzErrMsg, db,"cannot VACUUM - SQL statements in progress");

  134596.     return SQLITE_ERROR; /* IMP: R-15610-35227 */

  134597.   }

  134598.   saved_openFlags = db->openFlags;

  134599.   if( pOut ){

  134600.     if( sqlite3_value_type(pOut)!=SQLITE_TEXT ){

  134601.       sqlite3SetString(pzErrMsg, db, "non-text filename");

  134602.       return SQLITE_ERROR;

  134603.     }

  134604.     zOut = (const char*)sqlite3_value_text(pOut);

  134605.     db->openFlags &= ~SQLITE_OPEN_READONLY;

  134606.     db->openFlags |= SQLITE_OPEN_CREATE|SQLITE_OPEN_READWRITE;

  134607.   }else{

  134608.     zOut = "";

  134609.   }

  134610. 

  134611.   /* Save the current value of the database flags so that it can be 

  134612.   ** restored before returning. Then set the writable-schema flag, and

  134613.   ** disable CHECK and foreign key constraints.  */

  134614.   saved_flags = db->flags;

  134615.   saved_mDbFlags = db->mDbFlags;

  134616.   saved_nChange = db->nChange;

  134617.   saved_nTotalChange = db->nTotalChange;

  134618.   saved_mTrace = db->mTrace;

  134619.   db->flags |= SQLITE_WriteSchema | SQLITE_IgnoreChecks;

  134620.   db->mDbFlags |= DBFLAG_PreferBuiltin | DBFLAG_Vacuum;

  134621.   db->flags &= ~(u64)(SQLITE_ForeignKeys | SQLITE_ReverseOrder

  134622.                    | SQLITE_Defensive | SQLITE_CountRows);

  134623.   db->mTrace = 0;

  134624. 

  134625.   zDbMain = db->aDb[iDb].zDbSName;

  134626.   pMain = db->aDb[iDb].pBt;

  134627.   isMemDb = sqlite3PagerIsMemdb(sqlite3BtreePager(pMain));

  134628. 

  134629.   /* Attach the temporary database as 'vacuum_db'. The synchronous pragma

  134630.   ** can be set to 'off' for this file, as it is not recovered if a crash

  134631.   ** occurs anyway. The integrity of the database is maintained by a

  134632.   ** (possibly synchronous) transaction opened on the main database before

  134633.   ** sqlite3BtreeCopyFile() is called.

  134634.   **

  134635.   ** An optimisation would be to use a non-journaled pager.

  134636.   ** (Later:) I tried setting "PRAGMA vacuum_db.journal_mode=OFF" but

  134637.   ** that actually made the VACUUM run slower.  Very little journalling

  134638.   ** actually occurs when doing a vacuum since the vacuum_db is initially

  134639.   ** empty.  Only the journal header is written.  Apparently it takes more

  134640.   ** time to parse and run the PRAGMA to turn journalling off than it does

  134641.   ** to write the journal header file.

  134642.   */

  134643.   nDb = db->nDb;

  134644.   rc = execSqlF(db, pzErrMsg, "ATTACH %Q AS vacuum_db", zOut);

  134645.   db->openFlags = saved_openFlags;

  134646.   if( rc!=SQLITE_OK ) goto end_of_vacuum;

  134647.   assert( (db->nDb-1)==nDb );

  134648.   pDb = &db->aDb[nDb];

  134649.   assert( strcmp(pDb->zDbSName,"vacuum_db")==0 );

  134650.   pTemp = pDb->pBt;

  134651.   if( pOut ){

  134652.     sqlite3_file *id = sqlite3PagerFile(sqlite3BtreePager(pTemp));

  134653.     i64 sz = 0;

  134654.     if( id->pMethods!=0 && (sqlite3OsFileSize(id, &sz)!=SQLITE_OK || sz>0) ){

  134655.       rc = SQLITE_ERROR;

  134656.       sqlite3SetString(pzErrMsg, db, "output file already exists");

  134657.       goto end_of_vacuum;

  134658.     }

  134659.     db->mDbFlags |= DBFLAG_VacuumInto;

  134660.   }

  134661.   nRes = sqlite3BtreeGetOptimalReserve(pMain);

  134662. 

  134663.   /* A VACUUM cannot change the pagesize of an encrypted database. */

  134664. #ifdef SQLITE_HAS_CODEC

  134665.   if( db->nextPagesize ){

  134666.     extern void sqlite3CodecGetKey(sqlite3*, int, void**, int*);

  134667.     int nKey;

  134668.     char *zKey;

  134669.     sqlite3CodecGetKey(db, iDb, (void**)&zKey, &nKey);

  134670.     if( nKey ) db->nextPagesize = 0;

  134671.   }

  134672. #endif

  134673. 

  134674.   sqlite3BtreeSetCacheSize(pTemp, db->aDb[iDb].pSchema->cache_size);

  134675.   sqlite3BtreeSetSpillSize(pTemp, sqlite3BtreeSetSpillSize(pMain,0));

  134676.   sqlite3BtreeSetPagerFlags(pTemp, PAGER_SYNCHRONOUS_OFF|PAGER_CACHESPILL);

  134677. 

  134678.   /* Begin a transaction and take an exclusive lock on the main database

  134679.   ** file. This is done before the sqlite3BtreeGetPageSize(pMain) call below,

  134680.   ** to ensure that we do not try to change the page-size on a WAL database.

  134681.   */

  134682.   rc = execSql(db, pzErrMsg, "BEGIN");

  134683.   if( rc!=SQLITE_OK ) goto end_of_vacuum;

  134684.   rc = sqlite3BtreeBeginTrans(pMain, pOut==0 ? 2 : 0, 0);

  134685.   if( rc!=SQLITE_OK ) goto end_of_vacuum;

  134686. 

  134687.   /* Do not attempt to change the page size for a WAL database */

  134688.   if( sqlite3PagerGetJournalMode(sqlite3BtreePager(pMain))

  134689.                                                ==PAGER_JOURNALMODE_WAL ){

  134690.     db->nextPagesize = 0;

  134691.   }

  134692. 

  134693.   if( sqlite3BtreeSetPageSize(pTemp, sqlite3BtreeGetPageSize(pMain), nRes, 0)

  134694.    || (!isMemDb && sqlite3BtreeSetPageSize(pTemp, db->nextPagesize, nRes, 0))

  134695.    || NEVER(db->mallocFailed)

  134696.   ){

  134697.     rc = SQLITE_NOMEM_BKPT;

  134698.     goto end_of_vacuum;

  134699.   }

  134700. 

  134701. #ifndef SQLITE_OMIT_AUTOVACUUM

  134702.   sqlite3BtreeSetAutoVacuum(pTemp, db->nextAutovac>=0 ? db->nextAutovac :

  134703.                                            sqlite3BtreeGetAutoVacuum(pMain));

  134704. #endif

  134705. 

  134706.   /* Query the schema of the main database. Create a mirror schema

  134707.   ** in the temporary database.

  134708.   */

  134709.   db->init.iDb = nDb; /* force new CREATE statements into vacuum_db */

  134710.   rc = execSqlF(db, pzErrMsg,

  134711.       "SELECT sql FROM \"%w\".sqlite_master"

  134712.       " WHERE type='table'AND name<>'sqlite_sequence'"

  134713.       " AND coalesce(rootpage,1)>0",

  134714.       zDbMain

  134715.   );

  134716.   if( rc!=SQLITE_OK ) goto end_of_vacuum;

  134717.   rc = execSqlF(db, pzErrMsg,

  134718.       "SELECT sql FROM \"%w\".sqlite_master"

  134719.       " WHERE type='index'",

  134720.       zDbMain

  134721.   );

  134722.   if( rc!=SQLITE_OK ) goto end_of_vacuum;

  134723.   db->init.iDb = 0;

  134724. 

  134725.   /* Loop through the tables in the main database. For each, do

  134726.   ** an "INSERT INTO vacuum_db.xxx SELECT * FROM main.xxx;" to copy

  134727.   ** the contents to the temporary database.

  134728.   */

  134729.   rc = execSqlF(db, pzErrMsg,

  134730.       "SELECT'INSERT INTO vacuum_db.'||quote(name)"

  134731.       "||' SELECT*FROM\"%w\".'||quote(name)"

  134732.       "FROM vacuum_db.sqlite_master "

  134733.       "WHERE type='table'AND coalesce(rootpage,1)>0",

  134734.       zDbMain

  134735.   );

  134736.   assert( (db->mDbFlags & DBFLAG_Vacuum)!=0 );

  134737.   db->mDbFlags &= ~DBFLAG_Vacuum;

  134738.   if( rc!=SQLITE_OK ) goto end_of_vacuum;

  134739. 

  134740.   /* Copy the triggers, views, and virtual tables from the main database

  134741.   ** over to the temporary database.  None of these objects has any

  134742.   ** associated storage, so all we have to do is copy their entries

  134743.   ** from the SQLITE_MASTER table.

  134744.   */

  134745.   rc = execSqlF(db, pzErrMsg,

  134746.       "INSERT INTO vacuum_db.sqlite_master"

  134747.       " SELECT*FROM \"%w\".sqlite_master"

  134748.       " WHERE type IN('view','trigger')"

  134749.       " OR(type='table'AND rootpage=0)",

  134750.       zDbMain

  134751.   );

  134752.   if( rc ) goto end_of_vacuum;

  134753. 

  134754.   /* At this point, there is a write transaction open on both the 

  134755.   ** vacuum database and the main database. Assuming no error occurs,

  134756.   ** both transactions are closed by this block - the main database

  134757.   ** transaction by sqlite3BtreeCopyFile() and the other by an explicit

  134758.   ** call to sqlite3BtreeCommit().

  134759.   */

  134760.   {

  134761.     u32 meta;

  134762.     int i;

  134763. 

  134764.     /* This array determines which meta meta values are preserved in the

  134765.     ** vacuum.  Even entries are the meta value number and odd entries

  134766.     ** are an increment to apply to the meta value after the vacuum.

  134767.     ** The increment is used to increase the schema cookie so that other

  134768.     ** connections to the same database will know to reread the schema.

  134769.     */

  134770.     static const unsigned char aCopy[] = {

  134771.        BTREE_SCHEMA_VERSION,     1,  /* Add one to the old schema cookie */

  134772.        BTREE_DEFAULT_CACHE_SIZE, 0,  /* Preserve the default page cache size */

  134773.        BTREE_TEXT_ENCODING,      0,  /* Preserve the text encoding */

  134774.        BTREE_USER_VERSION,       0,  /* Preserve the user version */

  134775.        BTREE_APPLICATION_ID,     0,  /* Preserve the application id */

  134776.     };

  134777. 

  134778.     assert( 1==sqlite3BtreeIsInTrans(pTemp) );

  134779.     assert( pOut!=0 || 1==sqlite3BtreeIsInTrans(pMain) );

  134780. 

  134781.     /* Copy Btree meta values */

  134782.     for(i=0; i<ArraySize(aCopy); i+=2){

  134783.       /* GetMeta() and UpdateMeta() cannot fail in this context because

  134784.       ** we already have page 1 loaded into cache and marked dirty. */

  134785.       sqlite3BtreeGetMeta(pMain, aCopy[i], &meta);

  134786.       rc = sqlite3BtreeUpdateMeta(pTemp, aCopy[i], meta+aCopy[i+1]);

  134787.       if( NEVER(rc!=SQLITE_OK) ) goto end_of_vacuum;

  134788.     }

  134789. 

  134790.     if( pOut==0 ){

  134791.       rc = sqlite3BtreeCopyFile(pMain, pTemp);

  134792.     }

  134793.     if( rc!=SQLITE_OK ) goto end_of_vacuum;

  134794.     rc = sqlite3BtreeCommit(pTemp);

  134795.     if( rc!=SQLITE_OK ) goto end_of_vacuum;

  134796. #ifndef SQLITE_OMIT_AUTOVACUUM

  134797.     if( pOut==0 ){

  134798.       sqlite3BtreeSetAutoVacuum(pMain, sqlite3BtreeGetAutoVacuum(pTemp));

  134799.     }

  134800. #endif

  134801.   }

  134802. 

  134803.   assert( rc==SQLITE_OK );

  134804.   if( pOut==0 ){

  134805.     rc = sqlite3BtreeSetPageSize(pMain, sqlite3BtreeGetPageSize(pTemp), nRes,1);

  134806.   }

  134807. 

  134808. end_of_vacuum:

  134809.   /* Restore the original value of db->flags */

  134810.   db->init.iDb = 0;

  134811.   db->mDbFlags = saved_mDbFlags;

  134812.   db->flags = saved_flags;

  134813.   db->nChange = saved_nChange;

  134814.   db->nTotalChange = saved_nTotalChange;

  134815.   db->mTrace = saved_mTrace;

  134816.   sqlite3BtreeSetPageSize(pMain, -1, -1, 1);

  134817. 

  134818.   /* Currently there is an SQL level transaction open on the vacuum

  134819.   ** database. No locks are held on any other files (since the main file

  134820.   ** was committed at the btree level). So it safe to end the transaction

  134821.   ** by manually setting the autoCommit flag to true and detaching the

  134822.   ** vacuum database. The vacuum_db journal file is deleted when the pager

  134823.   ** is closed by the DETACH.

  134824.   */

  134825.   db->autoCommit = 1;

  134826. 

  134827.   if( pDb ){

  134828.     sqlite3BtreeClose(pDb->pBt);

  134829.     pDb->pBt = 0;

  134830.     pDb->pSchema = 0;

  134831.   }

  134832. 

  134833.   /* This both clears the schemas and reduces the size of the db->aDb[]

  134834.   ** array. */ 

  134835.   sqlite3ResetAllSchemasOfConnection(db);

  134836. 

  134837.   return rc;

  134838. }

  134839. 

  134840. #endif  /* SQLITE_OMIT_VACUUM && SQLITE_OMIT_ATTACH */

  134841. 

  134842. /************** End of vacuum.c **********************************************/

  134843. /************** Begin file vtab.c ********************************************/

  134844. /*

  134845. ** 2006 June 10

  134846. **

  134847. ** The author disclaims copyright to this source code.  In place of

  134848. ** a legal notice, here is a blessing:

  134849. **

  134850. **    May you do good and not evil.

  134851. **    May you find forgiveness for yourself and forgive others.

  134852. **    May you share freely, never taking more than you give.

  134853. **

  134854. *************************************************************************

  134855. ** This file contains code used to help implement virtual tables.

  134856. */

  134857. #ifndef SQLITE_OMIT_VIRTUALTABLE

  134858. /* #include "sqliteInt.h" */

  134859. 

  134860. /*

  134861. ** Before a virtual table xCreate() or xConnect() method is invoked, the

  134862. ** sqlite3.pVtabCtx member variable is set to point to an instance of

  134863. ** this struct allocated on the stack. It is used by the implementation of 

  134864. ** the sqlite3_declare_vtab() and sqlite3_vtab_config() APIs, both of which

  134865. ** are invoked only from within xCreate and xConnect methods.

  134866. */

  134867. struct VtabCtx {

  134868.   VTable *pVTable;    /* The virtual table being constructed */

  134869.   Table *pTab;        /* The Table object to which the virtual table belongs */

  134870.   VtabCtx *pPrior;    /* Parent context (if any) */

  134871.   int bDeclared;      /* True after sqlite3_declare_vtab() is called */

  134872. };

  134873. 

  134874. /*

  134875. ** Construct and install a Module object for a virtual table.  When this

  134876. ** routine is called, it is guaranteed that all appropriate locks are held

  134877. ** and the module is not already part of the connection.

  134878. */

  134879. SQLITE_PRIVATE Module *sqlite3VtabCreateModule(

  134880.   sqlite3 *db,                    /* Database in which module is registered */

  134881.   const char *zName,              /* Name assigned to this module */

  134882.   const sqlite3_module *pModule,  /* The definition of the module */

  134883.   void *pAux,                     /* Context pointer for xCreate/xConnect */

  134884.   void (*xDestroy)(void *)        /* Module destructor function */

  134885. ){

  134886.   Module *pMod;

  134887.   int nName = sqlite3Strlen30(zName);

  134888.   pMod = (Module *)sqlite3Malloc(sizeof(Module) + nName + 1);

  134889.   if( pMod==0 ){

  134890.     sqlite3OomFault(db);

  134891.   }else{

  134892.     Module *pDel;

  134893.     char *zCopy = (char *)(&pMod[1]);

  134894.     memcpy(zCopy, zName, nName+1);

  134895.     pMod->zName = zCopy;

  134896.     pMod->pModule = pModule;

  134897.     pMod->pAux = pAux;

  134898.     pMod->xDestroy = xDestroy;

  134899.     pMod->pEpoTab = 0;

  134900.     pDel = (Module *)sqlite3HashInsert(&db->aModule,zCopy,(void*)pMod);

  134901.     assert( pDel==0 || pDel==pMod );

  134902.     if( pDel ){

  134903.       sqlite3OomFault(db);

  134904.       sqlite3DbFree(db, pDel);

  134905.       pMod = 0;

  134906.     }

  134907.   }

  134908.   return pMod;

  134909. }

  134910. 

  134911. /*

  134912. ** The actual function that does the work of creating a new module.

  134913. ** This function implements the sqlite3_create_module() and

  134914. ** sqlite3_create_module_v2() interfaces.

  134915. */

  134916. static int createModule(

  134917.   sqlite3 *db,                    /* Database in which module is registered */

  134918.   const char *zName,              /* Name assigned to this module */

  134919.   const sqlite3_module *pModule,  /* The definition of the module */

  134920.   void *pAux,                     /* Context pointer for xCreate/xConnect */

  134921.   void (*xDestroy)(void *)        /* Module destructor function */

  134922. ){

  134923.   int rc = SQLITE_OK;

  134924. 

  134925.   sqlite3_mutex_enter(db->mutex);

  134926.   if( sqlite3HashFind(&db->aModule, zName) ){

  134927.     rc = SQLITE_MISUSE_BKPT;

  134928.   }else{

  134929.     (void)sqlite3VtabCreateModule(db, zName, pModule, pAux, xDestroy);

  134930.   }

  134931.   rc = sqlite3ApiExit(db, rc);

  134932.   if( rc!=SQLITE_OK && xDestroy ) xDestroy(pAux);

  134933.   sqlite3_mutex_leave(db->mutex);

  134934.   return rc;

  134935. }

  134936. 

  134937. 

  134938. /*

  134939. ** External API function used to create a new virtual-table module.

  134940. */

  134941. SQLITE_API int sqlite3_create_module(

  134942.   sqlite3 *db,                    /* Database in which module is registered */

  134943.   const char *zName,              /* Name assigned to this module */

  134944.   const sqlite3_module *pModule,  /* The definition of the module */

  134945.   void *pAux                      /* Context pointer for xCreate/xConnect */

  134946. ){

  134947. #ifdef SQLITE_ENABLE_API_ARMOR

  134948.   if( !sqlite3SafetyCheckOk(db) || zName==0 ) return SQLITE_MISUSE_BKPT;

  134949. #endif

  134950.   return createModule(db, zName, pModule, pAux, 0);

  134951. }

  134952. 

  134953. /*

  134954. ** External API function used to create a new virtual-table module.

  134955. */

  134956. SQLITE_API int sqlite3_create_module_v2(

  134957.   sqlite3 *db,                    /* Database in which module is registered */

  134958.   const char *zName,              /* Name assigned to this module */

  134959.   const sqlite3_module *pModule,  /* The definition of the module */

  134960.   void *pAux,                     /* Context pointer for xCreate/xConnect */

  134961.   void (*xDestroy)(void *)        /* Module destructor function */

  134962. ){

  134963. #ifdef SQLITE_ENABLE_API_ARMOR

  134964.   if( !sqlite3SafetyCheckOk(db) || zName==0 ) return SQLITE_MISUSE_BKPT;

  134965. #endif

  134966.   return createModule(db, zName, pModule, pAux, xDestroy);

  134967. }

  134968. 

  134969. /*

  134970. ** Lock the virtual table so that it cannot be disconnected.

  134971. ** Locks nest.  Every lock should have a corresponding unlock.

  134972. ** If an unlock is omitted, resources leaks will occur.  

  134973. **

  134974. ** If a disconnect is attempted while a virtual table is locked,

  134975. ** the disconnect is deferred until all locks have been removed.

  134976. */

  134977. SQLITE_PRIVATE void sqlite3VtabLock(VTable *pVTab){

  134978.   pVTab->nRef++;

  134979. }

  134980. 

  134981. 

  134982. /*

  134983. ** pTab is a pointer to a Table structure representing a virtual-table.

  134984. ** Return a pointer to the VTable object used by connection db to access 

  134985. ** this virtual-table, if one has been created, or NULL otherwise.

  134986. */

  134987. SQLITE_PRIVATE VTable *sqlite3GetVTable(sqlite3 *db, Table *pTab){

  134988.   VTable *pVtab;

  134989.   assert( IsVirtual(pTab) );

  134990.   for(pVtab=pTab->pVTable; pVtab && pVtab->db!=db; pVtab=pVtab->pNext);

  134991.   return pVtab;

  134992. }

  134993. 

  134994. /*

  134995. ** Decrement the ref-count on a virtual table object. When the ref-count

  134996. ** reaches zero, call the xDisconnect() method to delete the object.

  134997. */

  134998. SQLITE_PRIVATE void sqlite3VtabUnlock(VTable *pVTab){

  134999.   sqlite3 *db = pVTab->db;

  135000. 

  135001.   assert( db );

  135002.   assert( pVTab->nRef>0 );

  135003.   assert( db->magic==SQLITE_MAGIC_OPEN || db->magic==SQLITE_MAGIC_ZOMBIE );

  135004. 

  135005.   pVTab->nRef--;

  135006.   if( pVTab->nRef==0 ){

  135007.     sqlite3_vtab *p = pVTab->pVtab;

  135008.     if( p ){

  135009.       p->pModule->xDisconnect(p);

  135010.     }

  135011.     sqlite3DbFree(db, pVTab);

  135012.   }

  135013. }

  135014. 

  135015. /*

  135016. ** Table p is a virtual table. This function moves all elements in the

  135017. ** p->pVTable list to the sqlite3.pDisconnect lists of their associated

  135018. ** database connections to be disconnected at the next opportunity. 

  135019. ** Except, if argument db is not NULL, then the entry associated with

  135020. ** connection db is left in the p->pVTable list.

  135021. */

  135022. static VTable *vtabDisconnectAll(sqlite3 *db, Table *p){

  135023.   VTable *pRet = 0;

  135024.   VTable *pVTable = p->pVTable;

  135025.   p->pVTable = 0;

  135026. 

  135027.   /* Assert that the mutex (if any) associated with the BtShared database 

  135028.   ** that contains table p is held by the caller. See header comments 

  135029.   ** above function sqlite3VtabUnlockList() for an explanation of why

  135030.   ** this makes it safe to access the sqlite3.pDisconnect list of any

  135031.   ** database connection that may have an entry in the p->pVTable list.

  135032.   */

  135033.   assert( db==0 || sqlite3SchemaMutexHeld(db, 0, p->pSchema) );

  135034. 

  135035.   while( pVTable ){

  135036.     sqlite3 *db2 = pVTable->db;

  135037.     VTable *pNext = pVTable->pNext;

  135038.     assert( db2 );

  135039.     if( db2==db ){

  135040.       pRet = pVTable;

  135041.       p->pVTable = pRet;

  135042.       pRet->pNext = 0;

  135043.     }else{

  135044.       pVTable->pNext = db2->pDisconnect;

  135045.       db2->pDisconnect = pVTable;

  135046.     }

  135047.     pVTable = pNext;

  135048.   }

  135049. 

  135050.   assert( !db || pRet );

  135051.   return pRet;

  135052. }

  135053. 

  135054. /*

  135055. ** Table *p is a virtual table. This function removes the VTable object

  135056. ** for table *p associated with database connection db from the linked

  135057. ** list in p->pVTab. It also decrements the VTable ref count. This is

  135058. ** used when closing database connection db to free all of its VTable

  135059. ** objects without disturbing the rest of the Schema object (which may

  135060. ** be being used by other shared-cache connections).

  135061. */

  135062. SQLITE_PRIVATE void sqlite3VtabDisconnect(sqlite3 *db, Table *p){

  135063.   VTable **ppVTab;

  135064. 

  135065.   assert( IsVirtual(p) );

  135066.   assert( sqlite3BtreeHoldsAllMutexes(db) );

  135067.   assert( sqlite3_mutex_held(db->mutex) );

  135068. 

  135069.   for(ppVTab=&p->pVTable; *ppVTab; ppVTab=&(*ppVTab)->pNext){

  135070.     if( (*ppVTab)->db==db  ){

  135071.       VTable *pVTab = *ppVTab;

  135072.       *ppVTab = pVTab->pNext;

  135073.       sqlite3VtabUnlock(pVTab);

  135074.       break;

  135075.     }

  135076.   }

  135077. }

  135078. 

  135079. 

  135080. /*

  135081. ** Disconnect all the virtual table objects in the sqlite3.pDisconnect list.

  135082. **

  135083. ** This function may only be called when the mutexes associated with all

  135084. ** shared b-tree databases opened using connection db are held by the 

  135085. ** caller. This is done to protect the sqlite3.pDisconnect list. The

  135086. ** sqlite3.pDisconnect list is accessed only as follows:

  135087. **

  135088. **   1) By this function. In this case, all BtShared mutexes and the mutex

  135089. **      associated with the database handle itself must be held.

  135090. **

  135091. **   2) By function vtabDisconnectAll(), when it adds a VTable entry to

  135092. **      the sqlite3.pDisconnect list. In this case either the BtShared mutex

  135093. **      associated with the database the virtual table is stored in is held

  135094. **      or, if the virtual table is stored in a non-sharable database, then

  135095. **      the database handle mutex is held.

  135096. **

  135097. ** As a result, a sqlite3.pDisconnect cannot be accessed simultaneously 

  135098. ** by multiple threads. It is thread-safe.

  135099. */

  135100. SQLITE_PRIVATE void sqlite3VtabUnlockList(sqlite3 *db){

  135101.   VTable *p = db->pDisconnect;

  135102.   db->pDisconnect = 0;

  135103. 

  135104.   assert( sqlite3BtreeHoldsAllMutexes(db) );

  135105.   assert( sqlite3_mutex_held(db->mutex) );

  135106. 

  135107.   if( p ){

  135108.     sqlite3ExpirePreparedStatements(db, 0);

  135109.     do {

  135110.       VTable *pNext = p->pNext;

  135111.       sqlite3VtabUnlock(p);

  135112.       p = pNext;

  135113.     }while( p );

  135114.   }

  135115. }

  135116. 

  135117. /*

  135118. ** Clear any and all virtual-table information from the Table record.

  135119. ** This routine is called, for example, just before deleting the Table

  135120. ** record.

  135121. **

  135122. ** Since it is a virtual-table, the Table structure contains a pointer

  135123. ** to the head of a linked list of VTable structures. Each VTable 

  135124. ** structure is associated with a single sqlite3* user of the schema.

  135125. ** The reference count of the VTable structure associated with database 

  135126. ** connection db is decremented immediately (which may lead to the 

  135127. ** structure being xDisconnected and free). Any other VTable structures

  135128. ** in the list are moved to the sqlite3.pDisconnect list of the associated 

  135129. ** database connection.

  135130. */

  135131. SQLITE_PRIVATE void sqlite3VtabClear(sqlite3 *db, Table *p){

  135132.   if( !db || db->pnBytesFreed==0 ) vtabDisconnectAll(0, p);

  135133.   if( p->azModuleArg ){

  135134.     int i;

  135135.     for(i=0; i<p->nModuleArg; i++){

  135136.       if( i!=1 ) sqlite3DbFree(db, p->azModuleArg[i]);

  135137.     }

  135138.     sqlite3DbFree(db, p->azModuleArg);

  135139.   }

  135140. }

  135141. 

  135142. /*

  135143. ** Add a new module argument to pTable->azModuleArg[].

  135144. ** The string is not copied - the pointer is stored.  The

  135145. ** string will be freed automatically when the table is

  135146. ** deleted.

  135147. */

  135148. static void addModuleArgument(Parse *pParse, Table *pTable, char *zArg){

  135149.   sqlite3_int64 nBytes = sizeof(char *)*(2+pTable->nModuleArg);

  135150.   char **azModuleArg;

  135151.   sqlite3 *db = pParse->db;

  135152.   if( pTable->nModuleArg+3>=db->aLimit[SQLITE_LIMIT_COLUMN] ){

  135153.     sqlite3ErrorMsg(pParse, "too many columns on %s", pTable->zName);

  135154.   }

  135155.   azModuleArg = sqlite3DbRealloc(db, pTable->azModuleArg, nBytes);

  135156.   if( azModuleArg==0 ){

  135157.     sqlite3DbFree(db, zArg);

  135158.   }else{

  135159.     int i = pTable->nModuleArg++;

  135160.     azModuleArg[i] = zArg;

  135161.     azModuleArg[i+1] = 0;

  135162.     pTable->azModuleArg = azModuleArg;

  135163.   }

  135164. }

  135165. 

  135166. /*

  135167. ** The parser calls this routine when it first sees a CREATE VIRTUAL TABLE

  135168. ** statement.  The module name has been parsed, but the optional list

  135169. ** of parameters that follow the module name are still pending.

  135170. */

  135171. SQLITE_PRIVATE void sqlite3VtabBeginParse(

  135172.   Parse *pParse,        /* Parsing context */

  135173.   Token *pName1,        /* Name of new table, or database name */

  135174.   Token *pName2,        /* Name of new table or NULL */

  135175.   Token *pModuleName,   /* Name of the module for the virtual table */

  135176.   int ifNotExists       /* No error if the table already exists */

  135177. ){

  135178.   Table *pTable;        /* The new virtual table */

  135179.   sqlite3 *db;          /* Database connection */

  135180. 

  135181.   sqlite3StartTable(pParse, pName1, pName2, 0, 0, 1, ifNotExists);

  135182.   pTable = pParse->pNewTable;

  135183.   if( pTable==0 ) return;

  135184.   assert( 0==pTable->pIndex );

  135185. 

  135186.   db = pParse->db;

  135187. 

  135188.   assert( pTable->nModuleArg==0 );

  135189.   addModuleArgument(pParse, pTable, sqlite3NameFromToken(db, pModuleName));

  135190.   addModuleArgument(pParse, pTable, 0);

  135191.   addModuleArgument(pParse, pTable, sqlite3DbStrDup(db, pTable->zName));

  135192.   assert( (pParse->sNameToken.z==pName2->z && pName2->z!=0)

  135193.        || (pParse->sNameToken.z==pName1->z && pName2->z==0)

  135194.   );

  135195.   pParse->sNameToken.n = (int)(

  135196.       &pModuleName->z[pModuleName->n] - pParse->sNameToken.z

  135197.   );

  135198. 

  135199. #ifndef SQLITE_OMIT_AUTHORIZATION

  135200.   /* Creating a virtual table invokes the authorization callback twice.

  135201.   ** The first invocation, to obtain permission to INSERT a row into the

  135202.   ** sqlite_master table, has already been made by sqlite3StartTable().

  135203.   ** The second call, to obtain permission to create the table, is made now.

  135204.   */

  135205.   if( pTable->azModuleArg ){

  135206.     int iDb = sqlite3SchemaToIndex(db, pTable->pSchema);

  135207.     assert( iDb>=0 ); /* The database the table is being created in */

  135208.     sqlite3AuthCheck(pParse, SQLITE_CREATE_VTABLE, pTable->zName, 

  135209.             pTable->azModuleArg[0], pParse->db->aDb[iDb].zDbSName);

  135210.   }

  135211. #endif

  135212. }

  135213. 

  135214. /*

  135215. ** This routine takes the module argument that has been accumulating

  135216. ** in pParse->zArg[] and appends it to the list of arguments on the

  135217. ** virtual table currently under construction in pParse->pTable.

  135218. */

  135219. static void addArgumentToVtab(Parse *pParse){

  135220.   if( pParse->sArg.z && pParse->pNewTable ){

  135221.     const char *z = (const char*)pParse->sArg.z;

  135222.     int n = pParse->sArg.n;

  135223.     sqlite3 *db = pParse->db;

  135224.     addModuleArgument(pParse, pParse->pNewTable, sqlite3DbStrNDup(db, z, n));

  135225.   }

  135226. }

  135227. 

  135228. /*

  135229. ** The parser calls this routine after the CREATE VIRTUAL TABLE statement

  135230. ** has been completely parsed.

  135231. */

  135232. SQLITE_PRIVATE void sqlite3VtabFinishParse(Parse *pParse, Token *pEnd){

  135233.   Table *pTab = pParse->pNewTable;  /* The table being constructed */

  135234.   sqlite3 *db = pParse->db;         /* The database connection */

  135235. 

  135236.   if( pTab==0 ) return;

  135237.   addArgumentToVtab(pParse);

  135238.   pParse->sArg.z = 0;

  135239.   if( pTab->nModuleArg<1 ) return;

  135240.   

  135241.   /* If the CREATE VIRTUAL TABLE statement is being entered for the

  135242.   ** first time (in other words if the virtual table is actually being

  135243.   ** created now instead of just being read out of sqlite_master) then

  135244.   ** do additional initialization work and store the statement text

  135245.   ** in the sqlite_master table.

  135246.   */

  135247.   if( !db->init.busy ){

  135248.     char *zStmt;

  135249.     char *zWhere;

  135250.     int iDb;

  135251.     int iReg;

  135252.     Vdbe *v;

  135253. 

  135254.     /* Compute the complete text of the CREATE VIRTUAL TABLE statement */

  135255.     if( pEnd ){

  135256.       pParse->sNameToken.n = (int)(pEnd->z - pParse->sNameToken.z) + pEnd->n;

  135257.     }

  135258.     zStmt = sqlite3MPrintf(db, "CREATE VIRTUAL TABLE %T", &pParse->sNameToken);

  135259. 

  135260.     /* A slot for the record has already been allocated in the 

  135261.     ** SQLITE_MASTER table.  We just need to update that slot with all

  135262.     ** the information we've collected.  

  135263.     **

  135264.     ** The VM register number pParse->regRowid holds the rowid of an

  135265.     ** entry in the sqlite_master table tht was created for this vtab

  135266.     ** by sqlite3StartTable().

  135267.     */

  135268.     iDb = sqlite3SchemaToIndex(db, pTab->pSchema);

  135269.     sqlite3NestedParse(pParse,

  135270.       "UPDATE %Q.%s "

  135271.          "SET type='table', name=%Q, tbl_name=%Q, rootpage=0, sql=%Q "

  135272.        "WHERE rowid=#%d",

  135273.       db->aDb[iDb].zDbSName, MASTER_NAME,

  135274.       pTab->zName,

  135275.       pTab->zName,

  135276.       zStmt,

  135277.       pParse->regRowid

  135278.     );

  135279.     sqlite3DbFree(db, zStmt);

  135280.     v = sqlite3GetVdbe(pParse);

  135281.     sqlite3ChangeCookie(pParse, iDb);

  135282. 

  135283.     sqlite3VdbeAddOp0(v, OP_Expire);

  135284.     zWhere = sqlite3MPrintf(db, "name='%q' AND type='table'", pTab->zName);

  135285.     sqlite3VdbeAddParseSchemaOp(v, iDb, zWhere);

  135286. 

  135287.     iReg = ++pParse->nMem;

  135288.     sqlite3VdbeLoadString(v, iReg, pTab->zName);

  135289.     sqlite3VdbeAddOp2(v, OP_VCreate, iDb, iReg);

  135290.   }

  135291. 

  135292.   /* If we are rereading the sqlite_master table create the in-memory

  135293.   ** record of the table. The xConnect() method is not called until

  135294.   ** the first time the virtual table is used in an SQL statement. This

  135295.   ** allows a schema that contains virtual tables to be loaded before

  135296.   ** the required virtual table implementations are registered.  */

  135297.   else {

  135298.     Table *pOld;

  135299.     Schema *pSchema = pTab->pSchema;

  135300.     const char *zName = pTab->zName;

  135301.     assert( sqlite3SchemaMutexHeld(db, 0, pSchema) );

  135302.     pOld = sqlite3HashInsert(&pSchema->tblHash, zName, pTab);

  135303.     if( pOld ){

  135304.       sqlite3OomFault(db);

  135305.       assert( pTab==pOld );  /* Malloc must have failed inside HashInsert() */

  135306.       return;

  135307.     }

  135308.     pParse->pNewTable = 0;

  135309.   }

  135310. }

  135311. 

  135312. /*

  135313. ** The parser calls this routine when it sees the first token

  135314. ** of an argument to the module name in a CREATE VIRTUAL TABLE statement.

  135315. */

  135316. SQLITE_PRIVATE void sqlite3VtabArgInit(Parse *pParse){

  135317.   addArgumentToVtab(pParse);

  135318.   pParse->sArg.z = 0;

  135319.   pParse->sArg.n = 0;

  135320. }

  135321. 

  135322. /*

  135323. ** The parser calls this routine for each token after the first token

  135324. ** in an argument to the module name in a CREATE VIRTUAL TABLE statement.

  135325. */

  135326. SQLITE_PRIVATE void sqlite3VtabArgExtend(Parse *pParse, Token *p){

  135327.   Token *pArg = &pParse->sArg;

  135328.   if( pArg->z==0 ){

  135329.     pArg->z = p->z;

  135330.     pArg->n = p->n;

  135331.   }else{

  135332.     assert(pArg->z <= p->z);

  135333.     pArg->n = (int)(&p->z[p->n] - pArg->z);

  135334.   }

  135335. }

  135336. 

  135337. /*

  135338. ** Invoke a virtual table constructor (either xCreate or xConnect). The

  135339. ** pointer to the function to invoke is passed as the fourth parameter

  135340. ** to this procedure.

  135341. */

  135342. static int vtabCallConstructor(

  135343.   sqlite3 *db, 

  135344.   Table *pTab,

  135345.   Module *pMod,

  135346.   int (*xConstruct)(sqlite3*,void*,int,const char*const*,sqlite3_vtab**,char**),

  135347.   char **pzErr

  135348. ){

  135349.   VtabCtx sCtx;

  135350.   VTable *pVTable;

  135351.   int rc;

  135352.   const char *const*azArg = (const char *const*)pTab->azModuleArg;

  135353.   int nArg = pTab->nModuleArg;

  135354.   char *zErr = 0;

  135355.   char *zModuleName;

  135356.   int iDb;

  135357.   VtabCtx *pCtx;

  135358. 

  135359.   /* Check that the virtual-table is not already being initialized */

  135360.   for(pCtx=db->pVtabCtx; pCtx; pCtx=pCtx->pPrior){

  135361.     if( pCtx->pTab==pTab ){

  135362.       *pzErr = sqlite3MPrintf(db, 

  135363.           "vtable constructor called recursively: %s", pTab->zName

  135364.       );

  135365.       return SQLITE_LOCKED;

  135366.     }

  135367.   }

  135368. 

  135369.   zModuleName = sqlite3DbStrDup(db, pTab->zName);

  135370.   if( !zModuleName ){

  135371.     return SQLITE_NOMEM_BKPT;

  135372.   }

  135373. 

  135374.   pVTable = sqlite3MallocZero(sizeof(VTable));

  135375.   if( !pVTable ){

  135376.     sqlite3OomFault(db);

  135377.     sqlite3DbFree(db, zModuleName);

  135378.     return SQLITE_NOMEM_BKPT;

  135379.   }

  135380.   pVTable->db = db;

  135381.   pVTable->pMod = pMod;

  135382. 

  135383.   iDb = sqlite3SchemaToIndex(db, pTab->pSchema);

  135384.   pTab->azModuleArg[1] = db->aDb[iDb].zDbSName;

  135385. 

  135386.   /* Invoke the virtual table constructor */

  135387.   assert( &db->pVtabCtx );

  135388.   assert( xConstruct );

  135389.   sCtx.pTab = pTab;

  135390.   sCtx.pVTable = pVTable;

  135391.   sCtx.pPrior = db->pVtabCtx;

  135392.   sCtx.bDeclared = 0;

  135393.   db->pVtabCtx = &sCtx;

  135394.   rc = xConstruct(db, pMod->pAux, nArg, azArg, &pVTable->pVtab, &zErr);

  135395.   db->pVtabCtx = sCtx.pPrior;

  135396.   if( rc==SQLITE_NOMEM ) sqlite3OomFault(db);

  135397.   assert( sCtx.pTab==pTab );

  135398. 

  135399.   if( SQLITE_OK!=rc ){

  135400.     if( zErr==0 ){

  135401.       *pzErr = sqlite3MPrintf(db, "vtable constructor failed: %s", zModuleName);

  135402.     }else {

  135403.       *pzErr = sqlite3MPrintf(db, "%s", zErr);

  135404.       sqlite3_free(zErr);

  135405.     }

  135406.     sqlite3DbFree(db, pVTable);

  135407.   }else if( ALWAYS(pVTable->pVtab) ){

  135408.     /* Justification of ALWAYS():  A correct vtab constructor must allocate

  135409.     ** the sqlite3_vtab object if successful.  */

  135410.     memset(pVTable->pVtab, 0, sizeof(pVTable->pVtab[0]));

  135411.     pVTable->pVtab->pModule = pMod->pModule;

  135412.     pVTable->nRef = 1;

  135413.     if( sCtx.bDeclared==0 ){

  135414.       const char *zFormat = "vtable constructor did not declare schema: %s";

  135415.       *pzErr = sqlite3MPrintf(db, zFormat, pTab->zName);

  135416.       sqlite3VtabUnlock(pVTable);

  135417.       rc = SQLITE_ERROR;

  135418.     }else{

  135419.       int iCol;

  135420.       u8 oooHidden = 0;

  135421.       /* If everything went according to plan, link the new VTable structure

  135422.       ** into the linked list headed by pTab->pVTable. Then loop through the 

  135423.       ** columns of the table to see if any of them contain the token "hidden".

  135424.       ** If so, set the Column COLFLAG_HIDDEN flag and remove the token from

  135425.       ** the type string.  */

  135426.       pVTable->pNext = pTab->pVTable;

  135427.       pTab->pVTable = pVTable;

  135428. 

  135429.       for(iCol=0; iCol<pTab->nCol; iCol++){

  135430.         char *zType = sqlite3ColumnType(&pTab->aCol[iCol], "");

  135431.         int nType;

  135432.         int i = 0;

  135433.         nType = sqlite3Strlen30(zType);

  135434.         for(i=0; i<nType; i++){

  135435.           if( 0==sqlite3StrNICmp("hidden", &zType[i], 6)

  135436.            && (i==0 || zType[i-1]==' ')

  135437.            && (zType[i+6]=='\0' || zType[i+6]==' ')

  135438.           ){

  135439.             break;

  135440.           }

  135441.         }

  135442.         if( i<nType ){

  135443.           int j;

  135444.           int nDel = 6 + (zType[i+6] ? 1 : 0);

  135445.           for(j=i; (j+nDel)<=nType; j++){

  135446.             zType[j] = zType[j+nDel];

  135447.           }

  135448.           if( zType[i]=='\0' && i>0 ){

  135449.             assert(zType[i-1]==' ');

  135450.             zType[i-1] = '\0';

  135451.           }

  135452.           pTab->aCol[iCol].colFlags |= COLFLAG_HIDDEN;

  135453.           oooHidden = TF_OOOHidden;

  135454.         }else{

  135455.           pTab->tabFlags |= oooHidden;

  135456.         }

  135457.       }

  135458.     }

  135459.   }

  135460. 

  135461.   sqlite3DbFree(db, zModuleName);

  135462.   return rc;

  135463. }

  135464. 

  135465. /*

  135466. ** This function is invoked by the parser to call the xConnect() method

  135467. ** of the virtual table pTab. If an error occurs, an error code is returned 

  135468. ** and an error left in pParse.

  135469. **

  135470. ** This call is a no-op if table pTab is not a virtual table.

  135471. */

  135472. SQLITE_PRIVATE int sqlite3VtabCallConnect(Parse *pParse, Table *pTab){

  135473.   sqlite3 *db = pParse->db;

  135474.   const char *zMod;

  135475.   Module *pMod;

  135476.   int rc;

  135477. 

  135478.   assert( pTab );

  135479.   if( !IsVirtual(pTab) || sqlite3GetVTable(db, pTab) ){

  135480.     return SQLITE_OK;

  135481.   }

  135482. 

  135483.   /* Locate the required virtual table module */

  135484.   zMod = pTab->azModuleArg[0];

  135485.   pMod = (Module*)sqlite3HashFind(&db->aModule, zMod);

  135486. 

  135487.   if( !pMod ){

  135488.     const char *zModule = pTab->azModuleArg[0];

  135489.     sqlite3ErrorMsg(pParse, "no such module: %s", zModule);

  135490.     rc = SQLITE_ERROR;

  135491.   }else{

  135492.     char *zErr = 0;

  135493.     rc = vtabCallConstructor(db, pTab, pMod, pMod->pModule->xConnect, &zErr);

  135494.     if( rc!=SQLITE_OK ){

  135495.       sqlite3ErrorMsg(pParse, "%s", zErr);

  135496.       pParse->rc = rc;

  135497.     }

  135498.     sqlite3DbFree(db, zErr);

  135499.   }

  135500. 

  135501.   return rc;

  135502. }

  135503. /*

  135504. ** Grow the db->aVTrans[] array so that there is room for at least one

  135505. ** more v-table. Return SQLITE_NOMEM if a malloc fails, or SQLITE_OK otherwise.

  135506. */

  135507. static int growVTrans(sqlite3 *db){

  135508.   const int ARRAY_INCR = 5;

  135509. 

  135510.   /* Grow the sqlite3.aVTrans array if required */

  135511.   if( (db->nVTrans%ARRAY_INCR)==0 ){

  135512.     VTable **aVTrans;

  135513.     sqlite3_int64 nBytes = sizeof(sqlite3_vtab*)*

  135514.                                  ((sqlite3_int64)db->nVTrans + ARRAY_INCR);

  135515.     aVTrans = sqlite3DbRealloc(db, (void *)db->aVTrans, nBytes);

  135516.     if( !aVTrans ){

  135517.       return SQLITE_NOMEM_BKPT;

  135518.     }

  135519.     memset(&aVTrans[db->nVTrans], 0, sizeof(sqlite3_vtab *)*ARRAY_INCR);

  135520.     db->aVTrans = aVTrans;

  135521.   }

  135522. 

  135523.   return SQLITE_OK;

  135524. }

  135525. 

  135526. /*

  135527. ** Add the virtual table pVTab to the array sqlite3.aVTrans[]. Space should

  135528. ** have already been reserved using growVTrans().

  135529. */

  135530. static void addToVTrans(sqlite3 *db, VTable *pVTab){

  135531.   /* Add pVtab to the end of sqlite3.aVTrans */

  135532.   db->aVTrans[db->nVTrans++] = pVTab;

  135533.   sqlite3VtabLock(pVTab);

  135534. }

  135535. 

  135536. /*

  135537. ** This function is invoked by the vdbe to call the xCreate method

  135538. ** of the virtual table named zTab in database iDb. 

  135539. **

  135540. ** If an error occurs, *pzErr is set to point to an English language

  135541. ** description of the error and an SQLITE_XXX error code is returned.

  135542. ** In this case the caller must call sqlite3DbFree(db, ) on *pzErr.

  135543. */

  135544. SQLITE_PRIVATE int sqlite3VtabCallCreate(sqlite3 *db, int iDb, const char *zTab, char **pzErr){

  135545.   int rc = SQLITE_OK;

  135546.   Table *pTab;

  135547.   Module *pMod;

  135548.   const char *zMod;

  135549. 

  135550.   pTab = sqlite3FindTable(db, zTab, db->aDb[iDb].zDbSName);

  135551.   assert( pTab && IsVirtual(pTab) && !pTab->pVTable );

  135552. 

  135553.   /* Locate the required virtual table module */

  135554.   zMod = pTab->azModuleArg[0];

  135555.   pMod = (Module*)sqlite3HashFind(&db->aModule, zMod);

  135556. 

  135557.   /* If the module has been registered and includes a Create method, 

  135558.   ** invoke it now. If the module has not been registered, return an 

  135559.   ** error. Otherwise, do nothing.

  135560.   */

  135561.   if( pMod==0 || pMod->pModule->xCreate==0 || pMod->pModule->xDestroy==0 ){

  135562.     *pzErr = sqlite3MPrintf(db, "no such module: %s", zMod);

  135563.     rc = SQLITE_ERROR;

  135564.   }else{

  135565.     rc = vtabCallConstructor(db, pTab, pMod, pMod->pModule->xCreate, pzErr);

  135566.   }

  135567. 

  135568.   /* Justification of ALWAYS():  The xConstructor method is required to

  135569.   ** create a valid sqlite3_vtab if it returns SQLITE_OK. */

  135570.   if( rc==SQLITE_OK && ALWAYS(sqlite3GetVTable(db, pTab)) ){

  135571.     rc = growVTrans(db);

  135572.     if( rc==SQLITE_OK ){

  135573.       addToVTrans(db, sqlite3GetVTable(db, pTab));

  135574.     }

  135575.   }

  135576. 

  135577.   return rc;

  135578. }

  135579. 

  135580. /*

  135581. ** This function is used to set the schema of a virtual table.  It is only

  135582. ** valid to call this function from within the xCreate() or xConnect() of a

  135583. ** virtual table module.

  135584. */

  135585. SQLITE_API int sqlite3_declare_vtab(sqlite3 *db, const char *zCreateTable){

  135586.   VtabCtx *pCtx;

  135587.   int rc = SQLITE_OK;

  135588.   Table *pTab;

  135589.   char *zErr = 0;

  135590.   Parse sParse;

  135591. 

  135592. #ifdef SQLITE_ENABLE_API_ARMOR

  135593.   if( !sqlite3SafetyCheckOk(db) || zCreateTable==0 ){

  135594.     return SQLITE_MISUSE_BKPT;

  135595.   }

  135596. #endif

  135597.   sqlite3_mutex_enter(db->mutex);

  135598.   pCtx = db->pVtabCtx;

  135599.   if( !pCtx || pCtx->bDeclared ){

  135600.     sqlite3Error(db, SQLITE_MISUSE);

  135601.     sqlite3_mutex_leave(db->mutex);

  135602.     return SQLITE_MISUSE_BKPT;

  135603.   }

  135604.   pTab = pCtx->pTab;

  135605.   assert( IsVirtual(pTab) );

  135606. 

  135607.   memset(&sParse, 0, sizeof(sParse));

  135608.   sParse.eParseMode = PARSE_MODE_DECLARE_VTAB;

  135609.   sParse.db = db;

  135610.   sParse.nQueryLoop = 1;

  135611.   if( SQLITE_OK==sqlite3RunParser(&sParse, zCreateTable, &zErr) 

  135612.    && sParse.pNewTable

  135613.    && !db->mallocFailed

  135614.    && !sParse.pNewTable->pSelect

  135615.    && !IsVirtual(sParse.pNewTable)

  135616.   ){

  135617.     if( !pTab->aCol ){

  135618.       Table *pNew = sParse.pNewTable;

  135619.       Index *pIdx;

  135620.       pTab->aCol = pNew->aCol;

  135621.       pTab->nCol = pNew->nCol;

  135622.       pTab->tabFlags |= pNew->tabFlags & (TF_WithoutRowid|TF_NoVisibleRowid);

  135623.       pNew->nCol = 0;

  135624.       pNew->aCol = 0;

  135625.       assert( pTab->pIndex==0 );

  135626.       assert( HasRowid(pNew) || sqlite3PrimaryKeyIndex(pNew)!=0 );

  135627.       if( !HasRowid(pNew)

  135628.        && pCtx->pVTable->pMod->pModule->xUpdate!=0

  135629.        && sqlite3PrimaryKeyIndex(pNew)->nKeyCol!=1

  135630.       ){

  135631.         /* WITHOUT ROWID virtual tables must either be read-only (xUpdate==0)

  135632.         ** or else must have a single-column PRIMARY KEY */

  135633.         rc = SQLITE_ERROR;

  135634.       }

  135635.       pIdx = pNew->pIndex;

  135636.       if( pIdx ){

  135637.         assert( pIdx->pNext==0 );

  135638.         pTab->pIndex = pIdx;

  135639.         pNew->pIndex = 0;

  135640.         pIdx->pTable = pTab;

  135641.       }

  135642.     }

  135643.     pCtx->bDeclared = 1;

  135644.   }else{

  135645.     sqlite3ErrorWithMsg(db, SQLITE_ERROR, (zErr ? "%s" : 0), zErr);

  135646.     sqlite3DbFree(db, zErr);

  135647.     rc = SQLITE_ERROR;

  135648.   }

  135649.   sParse.eParseMode = PARSE_MODE_NORMAL;

  135650. 

  135651.   if( sParse.pVdbe ){

  135652.     sqlite3VdbeFinalize(sParse.pVdbe);

  135653.   }

  135654.   sqlite3DeleteTable(db, sParse.pNewTable);

  135655.   sqlite3ParserReset(&sParse);

  135656. 

  135657.   assert( (rc&0xff)==rc );

  135658.   rc = sqlite3ApiExit(db, rc);

  135659.   sqlite3_mutex_leave(db->mutex);

  135660.   return rc;

  135661. }

  135662. 

  135663. /*

  135664. ** This function is invoked by the vdbe to call the xDestroy method

  135665. ** of the virtual table named zTab in database iDb. This occurs

  135666. ** when a DROP TABLE is mentioned.

  135667. **

  135668. ** This call is a no-op if zTab is not a virtual table.

  135669. */

  135670. SQLITE_PRIVATE int sqlite3VtabCallDestroy(sqlite3 *db, int iDb, const char *zTab){

  135671.   int rc = SQLITE_OK;

  135672.   Table *pTab;

  135673. 

  135674.   pTab = sqlite3FindTable(db, zTab, db->aDb[iDb].zDbSName);

  135675.   if( pTab!=0 && ALWAYS(pTab->pVTable!=0) ){

  135676.     VTable *p;

  135677.     int (*xDestroy)(sqlite3_vtab *);

  135678.     for(p=pTab->pVTable; p; p=p->pNext){

  135679.       assert( p->pVtab );

  135680.       if( p->pVtab->nRef>0 ){

  135681.         return SQLITE_LOCKED;

  135682.       }

  135683.     }

  135684.     p = vtabDisconnectAll(db, pTab);

  135685.     xDestroy = p->pMod->pModule->xDestroy;

  135686.     assert( xDestroy!=0 );  /* Checked before the virtual table is created */

  135687.     pTab->nTabRef++;

  135688.     rc = xDestroy(p->pVtab);

  135689.     /* Remove the sqlite3_vtab* from the aVTrans[] array, if applicable */

  135690.     if( rc==SQLITE_OK ){

  135691.       assert( pTab->pVTable==p && p->pNext==0 );

  135692.       p->pVtab = 0;

  135693.       pTab->pVTable = 0;

  135694.       sqlite3VtabUnlock(p);

  135695.     }

  135696.     sqlite3DeleteTable(db, pTab);

  135697.   }

  135698. 

  135699.   return rc;

  135700. }

  135701. 

  135702. /*

  135703. ** This function invokes either the xRollback or xCommit method

  135704. ** of each of the virtual tables in the sqlite3.aVTrans array. The method

  135705. ** called is identified by the second argument, "offset", which is

  135706. ** the offset of the method to call in the sqlite3_module structure.

  135707. **

  135708. ** The array is cleared after invoking the callbacks. 

  135709. */

  135710. static void callFinaliser(sqlite3 *db, int offset){

  135711.   int i;

  135712.   if( db->aVTrans ){

  135713.     VTable **aVTrans = db->aVTrans;

  135714.     db->aVTrans = 0;

  135715.     for(i=0; i<db->nVTrans; i++){

  135716.       VTable *pVTab = aVTrans[i];

  135717.       sqlite3_vtab *p = pVTab->pVtab;

  135718.       if( p ){

  135719.         int (*x)(sqlite3_vtab *);

  135720.         x = *(int (**)(sqlite3_vtab *))((char *)p->pModule + offset);

  135721.         if( x ) x(p);

  135722.       }

  135723.       pVTab->iSavepoint = 0;

  135724.       sqlite3VtabUnlock(pVTab);

  135725.     }

  135726.     sqlite3DbFree(db, aVTrans);

  135727.     db->nVTrans = 0;

  135728.   }

  135729. }

  135730. 

  135731. /*

  135732. ** Invoke the xSync method of all virtual tables in the sqlite3.aVTrans

  135733. ** array. Return the error code for the first error that occurs, or

  135734. ** SQLITE_OK if all xSync operations are successful.

  135735. **

  135736. ** If an error message is available, leave it in p->zErrMsg.

  135737. */

  135738. SQLITE_PRIVATE int sqlite3VtabSync(sqlite3 *db, Vdbe *p){

  135739.   int i;

  135740.   int rc = SQLITE_OK;

  135741.   VTable **aVTrans = db->aVTrans;

  135742. 

  135743.   db->aVTrans = 0;

  135744.   for(i=0; rc==SQLITE_OK && i<db->nVTrans; i++){

  135745.     int (*x)(sqlite3_vtab *);

  135746.     sqlite3_vtab *pVtab = aVTrans[i]->pVtab;

  135747.     if( pVtab && (x = pVtab->pModule->xSync)!=0 ){

  135748.       rc = x(pVtab);

  135749.       sqlite3VtabImportErrmsg(p, pVtab);

  135750.     }

  135751.   }

  135752.   db->aVTrans = aVTrans;

  135753.   return rc;

  135754. }

  135755. 

  135756. /*

  135757. ** Invoke the xRollback method of all virtual tables in the 

  135758. ** sqlite3.aVTrans array. Then clear the array itself.

  135759. */

  135760. SQLITE_PRIVATE int sqlite3VtabRollback(sqlite3 *db){

  135761.   callFinaliser(db, offsetof(sqlite3_module,xRollback));

  135762.   return SQLITE_OK;

  135763. }

  135764. 

  135765. /*

  135766. ** Invoke the xCommit method of all virtual tables in the 

  135767. ** sqlite3.aVTrans array. Then clear the array itself.

  135768. */

  135769. SQLITE_PRIVATE int sqlite3VtabCommit(sqlite3 *db){

  135770.   callFinaliser(db, offsetof(sqlite3_module,xCommit));

  135771.   return SQLITE_OK;

  135772. }

  135773. 

  135774. /*

  135775. ** If the virtual table pVtab supports the transaction interface

  135776. ** (xBegin/xRollback/xCommit and optionally xSync) and a transaction is

  135777. ** not currently open, invoke the xBegin method now.

  135778. **

  135779. ** If the xBegin call is successful, place the sqlite3_vtab pointer

  135780. ** in the sqlite3.aVTrans array.

  135781. */

  135782. SQLITE_PRIVATE int sqlite3VtabBegin(sqlite3 *db, VTable *pVTab){

  135783.   int rc = SQLITE_OK;

  135784.   const sqlite3_module *pModule;

  135785. 

  135786.   /* Special case: If db->aVTrans is NULL and db->nVTrans is greater

  135787.   ** than zero, then this function is being called from within a

  135788.   ** virtual module xSync() callback. It is illegal to write to 

  135789.   ** virtual module tables in this case, so return SQLITE_LOCKED.

  135790.   */

  135791.   if( sqlite3VtabInSync(db) ){

  135792.     return SQLITE_LOCKED;

  135793.   }

  135794.   if( !pVTab ){

  135795.     return SQLITE_OK;

  135796.   } 

  135797.   pModule = pVTab->pVtab->pModule;

  135798. 

  135799.   if( pModule->xBegin ){

  135800.     int i;

  135801. 

  135802.     /* If pVtab is already in the aVTrans array, return early */

  135803.     for(i=0; i<db->nVTrans; i++){

  135804.       if( db->aVTrans[i]==pVTab ){

  135805.         return SQLITE_OK;

  135806.       }

  135807.     }

  135808. 

  135809.     /* Invoke the xBegin method. If successful, add the vtab to the 

  135810.     ** sqlite3.aVTrans[] array. */

  135811.     rc = growVTrans(db);

  135812.     if( rc==SQLITE_OK ){

  135813.       rc = pModule->xBegin(pVTab->pVtab);

  135814.       if( rc==SQLITE_OK ){

  135815.         int iSvpt = db->nStatement + db->nSavepoint;

  135816.         addToVTrans(db, pVTab);

  135817.         if( iSvpt && pModule->xSavepoint ){

  135818.           pVTab->iSavepoint = iSvpt;

  135819.           rc = pModule->xSavepoint(pVTab->pVtab, iSvpt-1);

  135820.         }

  135821.       }

  135822.     }

  135823.   }

  135824.   return rc;

  135825. }

  135826. 

  135827. /*

  135828. ** Invoke either the xSavepoint, xRollbackTo or xRelease method of all

  135829. ** virtual tables that currently have an open transaction. Pass iSavepoint

  135830. ** as the second argument to the virtual table method invoked.

  135831. **

  135832. ** If op is SAVEPOINT_BEGIN, the xSavepoint method is invoked. If it is

  135833. ** SAVEPOINT_ROLLBACK, the xRollbackTo method. Otherwise, if op is 

  135834. ** SAVEPOINT_RELEASE, then the xRelease method of each virtual table with

  135835. ** an open transaction is invoked.

  135836. **

  135837. ** If any virtual table method returns an error code other than SQLITE_OK, 

  135838. ** processing is abandoned and the error returned to the caller of this

  135839. ** function immediately. If all calls to virtual table methods are successful,

  135840. ** SQLITE_OK is returned.

  135841. */

  135842. SQLITE_PRIVATE int sqlite3VtabSavepoint(sqlite3 *db, int op, int iSavepoint){

  135843.   int rc = SQLITE_OK;

  135844. 

  135845.   assert( op==SAVEPOINT_RELEASE||op==SAVEPOINT_ROLLBACK||op==SAVEPOINT_BEGIN );

  135846.   assert( iSavepoint>=-1 );

  135847.   if( db->aVTrans ){

  135848.     int i;

  135849.     for(i=0; rc==SQLITE_OK && i<db->nVTrans; i++){

  135850.       VTable *pVTab = db->aVTrans[i];

  135851.       const sqlite3_module *pMod = pVTab->pMod->pModule;

  135852.       if( pVTab->pVtab && pMod->iVersion>=2 ){

  135853.         int (*xMethod)(sqlite3_vtab *, int);

  135854.         sqlite3VtabLock(pVTab);

  135855.         switch( op ){

  135856.           case SAVEPOINT_BEGIN:

  135857.             xMethod = pMod->xSavepoint;

  135858.             pVTab->iSavepoint = iSavepoint+1;

  135859.             break;

  135860.           case SAVEPOINT_ROLLBACK:

  135861.             xMethod = pMod->xRollbackTo;

  135862.             break;

  135863.           default:

  135864.             xMethod = pMod->xRelease;

  135865.             break;

  135866.         }

  135867.         if( xMethod && pVTab->iSavepoint>iSavepoint ){

  135868.           rc = xMethod(pVTab->pVtab, iSavepoint);

  135869.         }

  135870.         sqlite3VtabUnlock(pVTab);

  135871.       }

  135872.     }

  135873.   }

  135874.   return rc;

  135875. }

  135876. 

  135877. /*

  135878. ** The first parameter (pDef) is a function implementation.  The

  135879. ** second parameter (pExpr) is the first argument to this function.

  135880. ** If pExpr is a column in a virtual table, then let the virtual

  135881. ** table implementation have an opportunity to overload the function.

  135882. **

  135883. ** This routine is used to allow virtual table implementations to

  135884. ** overload MATCH, LIKE, GLOB, and REGEXP operators.

  135885. **

  135886. ** Return either the pDef argument (indicating no change) or a 

  135887. ** new FuncDef structure that is marked as ephemeral using the

  135888. ** SQLITE_FUNC_EPHEM flag.

  135889. */

  135890. SQLITE_PRIVATE FuncDef *sqlite3VtabOverloadFunction(

  135891.   sqlite3 *db,    /* Database connection for reporting malloc problems */

  135892.   FuncDef *pDef,  /* Function to possibly overload */

  135893.   int nArg,       /* Number of arguments to the function */

  135894.   Expr *pExpr     /* First argument to the function */

  135895. ){

  135896.   Table *pTab;

  135897.   sqlite3_vtab *pVtab;

  135898.   sqlite3_module *pMod;

  135899.   void (*xSFunc)(sqlite3_context*,int,sqlite3_value**) = 0;

  135900.   void *pArg = 0;

  135901.   FuncDef *pNew;

  135902.   int rc = 0;

  135903. 

  135904.   /* Check to see the left operand is a column in a virtual table */

  135905.   if( NEVER(pExpr==0) ) return pDef;

  135906.   if( pExpr->op!=TK_COLUMN ) return pDef;

  135907.   pTab = pExpr->y.pTab;

  135908.   if( pTab==0 ) return pDef;

  135909.   if( !IsVirtual(pTab) ) return pDef;

  135910.   pVtab = sqlite3GetVTable(db, pTab)->pVtab;

  135911.   assert( pVtab!=0 );

  135912.   assert( pVtab->pModule!=0 );

  135913.   pMod = (sqlite3_module *)pVtab->pModule;

  135914.   if( pMod->xFindFunction==0 ) return pDef;

  135915.  

  135916.   /* Call the xFindFunction method on the virtual table implementation

  135917.   ** to see if the implementation wants to overload this function.

  135918.   **

  135919.   ** Though undocumented, we have historically always invoked xFindFunction

  135920.   ** with an all lower-case function name.  Continue in this tradition to

  135921.   ** avoid any chance of an incompatibility.

  135922.   */

  135923. #ifdef SQLITE_DEBUG

  135924.   {

  135925.     int i;

  135926.     for(i=0; pDef->zName[i]; i++){

  135927.       unsigned char x = (unsigned char)pDef->zName[i];

  135928.       assert( x==sqlite3UpperToLower[x] );

  135929.     }

  135930.   }

  135931. #endif

  135932.   rc = pMod->xFindFunction(pVtab, nArg, pDef->zName, &xSFunc, &pArg);

  135933.   if( rc==0 ){

  135934.     return pDef;

  135935.   }

  135936. 

  135937.   /* Create a new ephemeral function definition for the overloaded

  135938.   ** function */

  135939.   pNew = sqlite3DbMallocZero(db, sizeof(*pNew)

  135940.                              + sqlite3Strlen30(pDef->zName) + 1);

  135941.   if( pNew==0 ){

  135942.     return pDef;

  135943.   }

  135944.   *pNew = *pDef;

  135945.   pNew->zName = (const char*)&pNew[1];

  135946.   memcpy((char*)&pNew[1], pDef->zName, sqlite3Strlen30(pDef->zName)+1);

  135947.   pNew->xSFunc = xSFunc;

  135948.   pNew->pUserData = pArg;

  135949.   pNew->funcFlags |= SQLITE_FUNC_EPHEM;

  135950.   return pNew;

  135951. }

  135952. 

  135953. /*

  135954. ** Make sure virtual table pTab is contained in the pParse->apVirtualLock[]

  135955. ** array so that an OP_VBegin will get generated for it.  Add pTab to the

  135956. ** array if it is missing.  If pTab is already in the array, this routine

  135957. ** is a no-op.

  135958. */

  135959. SQLITE_PRIVATE void sqlite3VtabMakeWritable(Parse *pParse, Table *pTab){

  135960.   Parse *pToplevel = sqlite3ParseToplevel(pParse);

  135961.   int i, n;

  135962.   Table **apVtabLock;

  135963. 

  135964.   assert( IsVirtual(pTab) );

  135965.   for(i=0; i<pToplevel->nVtabLock; i++){

  135966.     if( pTab==pToplevel->apVtabLock[i] ) return;

  135967.   }

  135968.   n = (pToplevel->nVtabLock+1)*sizeof(pToplevel->apVtabLock[0]);

  135969.   apVtabLock = sqlite3_realloc64(pToplevel->apVtabLock, n);

  135970.   if( apVtabLock ){

  135971.     pToplevel->apVtabLock = apVtabLock;

  135972.     pToplevel->apVtabLock[pToplevel->nVtabLock++] = pTab;

  135973.   }else{

  135974.     sqlite3OomFault(pToplevel->db);

  135975.   }

  135976. }

  135977. 

  135978. /*

  135979. ** Check to see if virtual table module pMod can be have an eponymous

  135980. ** virtual table instance.  If it can, create one if one does not already

  135981. ** exist. Return non-zero if the eponymous virtual table instance exists

  135982. ** when this routine returns, and return zero if it does not exist.

  135983. **

  135984. ** An eponymous virtual table instance is one that is named after its

  135985. ** module, and more importantly, does not require a CREATE VIRTUAL TABLE

  135986. ** statement in order to come into existance.  Eponymous virtual table

  135987. ** instances always exist.  They cannot be DROP-ed.

  135988. **

  135989. ** Any virtual table module for which xConnect and xCreate are the same

  135990. ** method can have an eponymous virtual table instance.

  135991. */

  135992. SQLITE_PRIVATE int sqlite3VtabEponymousTableInit(Parse *pParse, Module *pMod){

  135993.   const sqlite3_module *pModule = pMod->pModule;

  135994.   Table *pTab;

  135995.   char *zErr = 0;

  135996.   int rc;

  135997.   sqlite3 *db = pParse->db;

  135998.   if( pMod->pEpoTab ) return 1;

  135999.   if( pModule->xCreate!=0 && pModule->xCreate!=pModule->xConnect ) return 0;

  136000.   pTab = sqlite3DbMallocZero(db, sizeof(Table));

  136001.   if( pTab==0 ) return 0;

  136002.   pTab->zName = sqlite3DbStrDup(db, pMod->zName);

  136003.   if( pTab->zName==0 ){

  136004.     sqlite3DbFree(db, pTab);

  136005.     return 0;

  136006.   }

  136007.   pMod->pEpoTab = pTab;

  136008.   pTab->nTabRef = 1;

  136009.   pTab->pSchema = db->aDb[0].pSchema;

  136010.   assert( pTab->nModuleArg==0 );

  136011.   pTab->iPKey = -1;

  136012.   addModuleArgument(pParse, pTab, sqlite3DbStrDup(db, pTab->zName));

  136013.   addModuleArgument(pParse, pTab, 0);

  136014.   addModuleArgument(pParse, pTab, sqlite3DbStrDup(db, pTab->zName));

  136015.   rc = vtabCallConstructor(db, pTab, pMod, pModule->xConnect, &zErr);

  136016.   if( rc ){

  136017.     sqlite3ErrorMsg(pParse, "%s", zErr);

  136018.     sqlite3DbFree(db, zErr);

  136019.     sqlite3VtabEponymousTableClear(db, pMod);

  136020.     return 0;

  136021.   }

  136022.   return 1;

  136023. }

  136024. 

  136025. /*

  136026. ** Erase the eponymous virtual table instance associated with

  136027. ** virtual table module pMod, if it exists.

  136028. */

  136029. SQLITE_PRIVATE void sqlite3VtabEponymousTableClear(sqlite3 *db, Module *pMod){

  136030.   Table *pTab = pMod->pEpoTab;

  136031.   if( pTab!=0 ){

  136032.     /* Mark the table as Ephemeral prior to deleting it, so that the

  136033.     ** sqlite3DeleteTable() routine will know that it is not stored in 

  136034.     ** the schema. */

  136035.     pTab->tabFlags |= TF_Ephemeral;

  136036.     sqlite3DeleteTable(db, pTab);

  136037.     pMod->pEpoTab = 0;

  136038.   }

  136039. }

  136040. 

  136041. /*

  136042. ** Return the ON CONFLICT resolution mode in effect for the virtual

  136043. ** table update operation currently in progress.

  136044. **

  136045. ** The results of this routine are undefined unless it is called from

  136046. ** within an xUpdate method.

  136047. */

  136048. SQLITE_API int sqlite3_vtab_on_conflict(sqlite3 *db){

  136049.   static const unsigned char aMap[] = { 

  136050.     SQLITE_ROLLBACK, SQLITE_ABORT, SQLITE_FAIL, SQLITE_IGNORE, SQLITE_REPLACE 

  136051.   };

  136052. #ifdef SQLITE_ENABLE_API_ARMOR

  136053.   if( !sqlite3SafetyCheckOk(db) ) return SQLITE_MISUSE_BKPT;

  136054. #endif

  136055.   assert( OE_Rollback==1 && OE_Abort==2 && OE_Fail==3 );

  136056.   assert( OE_Ignore==4 && OE_Replace==5 );

  136057.   assert( db->vtabOnConflict>=1 && db->vtabOnConflict<=5 );

  136058.   return (int)aMap[db->vtabOnConflict-1];

  136059. }

  136060. 

  136061. /*

  136062. ** Call from within the xCreate() or xConnect() methods to provide 

  136063. ** the SQLite core with additional information about the behavior

  136064. ** of the virtual table being implemented.

  136065. */

  136066. SQLITE_API int sqlite3_vtab_config(sqlite3 *db, int op, ...){

  136067.   va_list ap;

  136068.   int rc = SQLITE_OK;

  136069. 

  136070. #ifdef SQLITE_ENABLE_API_ARMOR

  136071.   if( !sqlite3SafetyCheckOk(db) ) return SQLITE_MISUSE_BKPT;

  136072. #endif

  136073.   sqlite3_mutex_enter(db->mutex);

  136074.   va_start(ap, op);

  136075.   switch( op ){

  136076.     case SQLITE_VTAB_CONSTRAINT_SUPPORT: {

  136077.       VtabCtx *p = db->pVtabCtx;

  136078.       if( !p ){

  136079.         rc = SQLITE_MISUSE_BKPT;

  136080.       }else{

  136081.         assert( p->pTab==0 || IsVirtual(p->pTab) );

  136082.         p->pVTable->bConstraint = (u8)va_arg(ap, int);

  136083.       }

  136084.       break;

  136085.     }

  136086.     default:

  136087.       rc = SQLITE_MISUSE_BKPT;

  136088.       break;

  136089.   }

  136090.   va_end(ap);

  136091. 

  136092.   if( rc!=SQLITE_OK ) sqlite3Error(db, rc);

  136093.   sqlite3_mutex_leave(db->mutex);

  136094.   return rc;

  136095. }

  136096. 

  136097. #endif /* SQLITE_OMIT_VIRTUALTABLE */

  136098. 

  136099. /************** End of vtab.c ************************************************/

  136100. /************** Begin file wherecode.c ***************************************/

  136101. /*

  136102. ** 2015-06-06

  136103. **

  136104. ** The author disclaims copyright to this source code.  In place of

  136105. ** a legal notice, here is a blessing:

  136106. **

  136107. **    May you do good and not evil.

  136108. **    May you find forgiveness for yourself and forgive others.

  136109. **    May you share freely, never taking more than you give.

  136110. **

  136111. *************************************************************************

  136112. ** This module contains C code that generates VDBE code used to process

  136113. ** the WHERE clause of SQL statements.

  136114. **

  136115. ** This file was split off from where.c on 2015-06-06 in order to reduce the

  136116. ** size of where.c and make it easier to edit.  This file contains the routines

  136117. ** that actually generate the bulk of the WHERE loop code.  The original where.c

  136118. ** file retains the code that does query planning and analysis.

  136119. */

  136120. /* #include "sqliteInt.h" */

  136121. /************** Include whereInt.h in the middle of wherecode.c **************/

  136122. /************** Begin file whereInt.h ****************************************/

  136123. /*

  136124. ** 2013-11-12

  136125. **

  136126. ** The author disclaims copyright to this source code.  In place of

  136127. ** a legal notice, here is a blessing:

  136128. **

  136129. **    May you do good and not evil.

  136130. **    May you find forgiveness for yourself and forgive others.

  136131. **    May you share freely, never taking more than you give.

  136132. **

  136133. *************************************************************************

  136134. **

  136135. ** This file contains structure and macro definitions for the query

  136136. ** planner logic in "where.c".  These definitions are broken out into

  136137. ** a separate source file for easier editing.

  136138. */

  136139. #ifndef SQLITE_WHEREINT_H

  136140. #define SQLITE_WHEREINT_H

  136141. 

  136142. /*

  136143. ** Trace output macros

  136144. */

  136145. #if defined(SQLITE_TEST) || defined(SQLITE_DEBUG)

  136146. /***/ extern int sqlite3WhereTrace;

  136147. #endif

  136148. #if defined(SQLITE_DEBUG) \

  136149.     && (defined(SQLITE_TEST) || defined(SQLITE_ENABLE_WHERETRACE))

  136150. # define WHERETRACE(K,X)  if(sqlite3WhereTrace&(K)) sqlite3DebugPrintf X

  136151. # define WHERETRACE_ENABLED 1

  136152. #else

  136153. # define WHERETRACE(K,X)

  136154. #endif

  136155. 

  136156. /* Forward references

  136157. */

  136158. typedef struct WhereClause WhereClause;

  136159. typedef struct WhereMaskSet WhereMaskSet;

  136160. typedef struct WhereOrInfo WhereOrInfo;

  136161. typedef struct WhereAndInfo WhereAndInfo;

  136162. typedef struct WhereLevel WhereLevel;

  136163. typedef struct WhereLoop WhereLoop;

  136164. typedef struct WherePath WherePath;

  136165. typedef struct WhereTerm WhereTerm;

  136166. typedef struct WhereLoopBuilder WhereLoopBuilder;

  136167. typedef struct WhereScan WhereScan;

  136168. typedef struct WhereOrCost WhereOrCost;

  136169. typedef struct WhereOrSet WhereOrSet;

  136170. 

  136171. /*

  136172. ** This object contains information needed to implement a single nested

  136173. ** loop in WHERE clause.

  136174. **

  136175. ** Contrast this object with WhereLoop.  This object describes the

  136176. ** implementation of the loop.  WhereLoop describes the algorithm.

  136177. ** This object contains a pointer to the WhereLoop algorithm as one of

  136178. ** its elements.

  136179. **

  136180. ** The WhereInfo object contains a single instance of this object for

  136181. ** each term in the FROM clause (which is to say, for each of the

  136182. ** nested loops as implemented).  The order of WhereLevel objects determines

  136183. ** the loop nested order, with WhereInfo.a[0] being the outer loop and

  136184. ** WhereInfo.a[WhereInfo.nLevel-1] being the inner loop.

  136185. */

  136186. struct WhereLevel {

  136187.   int iLeftJoin;        /* Memory cell used to implement LEFT OUTER JOIN */

  136188.   int iTabCur;          /* The VDBE cursor used to access the table */

  136189.   int iIdxCur;          /* The VDBE cursor used to access pIdx */

  136190.   int addrBrk;          /* Jump here to break out of the loop */

  136191.   int addrNxt;          /* Jump here to start the next IN combination */

  136192.   int addrSkip;         /* Jump here for next iteration of skip-scan */

  136193.   int addrCont;         /* Jump here to continue with the next loop cycle */

  136194.   int addrFirst;        /* First instruction of interior of the loop */

  136195.   int addrBody;         /* Beginning of the body of this loop */

  136196. #ifndef SQLITE_LIKE_DOESNT_MATCH_BLOBS

  136197.   u32 iLikeRepCntr;     /* LIKE range processing counter register (times 2) */

  136198.   int addrLikeRep;      /* LIKE range processing address */

  136199. #endif

  136200.   u8 iFrom;             /* Which entry in the FROM clause */

  136201.   u8 op, p3, p5;        /* Opcode, P3 & P5 of the opcode that ends the loop */

  136202.   int p1, p2;           /* Operands of the opcode used to ends the loop */

  136203.   union {               /* Information that depends on pWLoop->wsFlags */

  136204.     struct {

  136205.       int nIn;              /* Number of entries in aInLoop[] */

  136206.       struct InLoop {

  136207.         int iCur;              /* The VDBE cursor used by this IN operator */

  136208.         int addrInTop;         /* Top of the IN loop */

  136209.         int iBase;             /* Base register of multi-key index record */

  136210.         int nPrefix;           /* Number of prior entires in the key */

  136211.         u8 eEndLoopOp;         /* IN Loop terminator. OP_Next or OP_Prev */

  136212.       } *aInLoop;           /* Information about each nested IN operator */

  136213.     } in;                 /* Used when pWLoop->wsFlags&WHERE_IN_ABLE */

  136214.     Index *pCovidx;       /* Possible covering index for WHERE_MULTI_OR */

  136215.   } u;

  136216.   struct WhereLoop *pWLoop;  /* The selected WhereLoop object */

  136217.   Bitmask notReady;          /* FROM entries not usable at this level */

  136218. #ifdef SQLITE_ENABLE_STMT_SCANSTATUS

  136219.   int addrVisit;        /* Address at which row is visited */

  136220. #endif

  136221. };

  136222. 

  136223. /*

  136224. ** Each instance of this object represents an algorithm for evaluating one

  136225. ** term of a join.  Every term of the FROM clause will have at least

  136226. ** one corresponding WhereLoop object (unless INDEXED BY constraints

  136227. ** prevent a query solution - which is an error) and many terms of the

  136228. ** FROM clause will have multiple WhereLoop objects, each describing a

  136229. ** potential way of implementing that FROM-clause term, together with

  136230. ** dependencies and cost estimates for using the chosen algorithm.

  136231. **

  136232. ** Query planning consists of building up a collection of these WhereLoop

  136233. ** objects, then computing a particular sequence of WhereLoop objects, with

  136234. ** one WhereLoop object per FROM clause term, that satisfy all dependencies

  136235. ** and that minimize the overall cost.

  136236. */

  136237. struct WhereLoop {

  136238.   Bitmask prereq;       /* Bitmask of other loops that must run first */

  136239.   Bitmask maskSelf;     /* Bitmask identifying table iTab */

  136240. #ifdef SQLITE_DEBUG

  136241.   char cId;             /* Symbolic ID of this loop for debugging use */

  136242. #endif

  136243.   u8 iTab;              /* Position in FROM clause of table for this loop */

  136244.   u8 iSortIdx;          /* Sorting index number.  0==None */

  136245.   LogEst rSetup;        /* One-time setup cost (ex: create transient index) */

  136246.   LogEst rRun;          /* Cost of running each loop */

  136247.   LogEst nOut;          /* Estimated number of output rows */

  136248.   union {

  136249.     struct {               /* Information for internal btree tables */

  136250.       u16 nEq;               /* Number of equality constraints */

  136251.       u16 nBtm;              /* Size of BTM vector */

  136252.       u16 nTop;              /* Size of TOP vector */

  136253.       u16 nIdxCol;           /* Index column used for ORDER BY */

  136254.       Index *pIndex;         /* Index used, or NULL */

  136255.     } btree;

  136256.     struct {               /* Information for virtual tables */

  136257.       int idxNum;            /* Index number */

  136258.       u8 needFree;           /* True if sqlite3_free(idxStr) is needed */

  136259.       i8 isOrdered;          /* True if satisfies ORDER BY */

  136260.       u16 omitMask;          /* Terms that may be omitted */

  136261.       char *idxStr;          /* Index identifier string */

  136262.     } vtab;

  136263.   } u;

  136264.   u32 wsFlags;          /* WHERE_* flags describing the plan */

  136265.   u16 nLTerm;           /* Number of entries in aLTerm[] */

  136266.   u16 nSkip;            /* Number of NULL aLTerm[] entries */

  136267.   /**** whereLoopXfer() copies fields above ***********************/

  136268. # define WHERE_LOOP_XFER_SZ offsetof(WhereLoop,nLSlot)

  136269.   u16 nLSlot;           /* Number of slots allocated for aLTerm[] */

  136270.   WhereTerm **aLTerm;   /* WhereTerms used */

  136271.   WhereLoop *pNextLoop; /* Next WhereLoop object in the WhereClause */

  136272.   WhereTerm *aLTermSpace[3];  /* Initial aLTerm[] space */

  136273. };

  136274. 

  136275. /* This object holds the prerequisites and the cost of running a

  136276. ** subquery on one operand of an OR operator in the WHERE clause.

  136277. ** See WhereOrSet for additional information 

  136278. */

  136279. struct WhereOrCost {

  136280.   Bitmask prereq;     /* Prerequisites */

  136281.   LogEst rRun;        /* Cost of running this subquery */

  136282.   LogEst nOut;        /* Number of outputs for this subquery */

  136283. };

  136284. 

  136285. /* The WhereOrSet object holds a set of possible WhereOrCosts that

  136286. ** correspond to the subquery(s) of OR-clause processing.  Only the

  136287. ** best N_OR_COST elements are retained.

  136288. */

  136289. #define N_OR_COST 3

  136290. struct WhereOrSet {

  136291.   u16 n;                      /* Number of valid a[] entries */

  136292.   WhereOrCost a[N_OR_COST];   /* Set of best costs */

  136293. };

  136294. 

  136295. /*

  136296. ** Each instance of this object holds a sequence of WhereLoop objects

  136297. ** that implement some or all of a query plan.

  136298. **

  136299. ** Think of each WhereLoop object as a node in a graph with arcs

  136300. ** showing dependencies and costs for travelling between nodes.  (That is

  136301. ** not a completely accurate description because WhereLoop costs are a

  136302. ** vector, not a scalar, and because dependencies are many-to-one, not

  136303. ** one-to-one as are graph nodes.  But it is a useful visualization aid.)

  136304. ** Then a WherePath object is a path through the graph that visits some

  136305. ** or all of the WhereLoop objects once.

  136306. **

  136307. ** The "solver" works by creating the N best WherePath objects of length

  136308. ** 1.  Then using those as a basis to compute the N best WherePath objects

  136309. ** of length 2.  And so forth until the length of WherePaths equals the

  136310. ** number of nodes in the FROM clause.  The best (lowest cost) WherePath

  136311. ** at the end is the chosen query plan.

  136312. */

  136313. struct WherePath {

  136314.   Bitmask maskLoop;     /* Bitmask of all WhereLoop objects in this path */

  136315.   Bitmask revLoop;      /* aLoop[]s that should be reversed for ORDER BY */

  136316.   LogEst nRow;          /* Estimated number of rows generated by this path */

  136317.   LogEst rCost;         /* Total cost of this path */

  136318.   LogEst rUnsorted;     /* Total cost of this path ignoring sorting costs */

  136319.   i8 isOrdered;         /* No. of ORDER BY terms satisfied. -1 for unknown */

  136320.   WhereLoop **aLoop;    /* Array of WhereLoop objects implementing this path */

  136321. };

  136322. 

  136323. /*

  136324. ** The query generator uses an array of instances of this structure to

  136325. ** help it analyze the subexpressions of the WHERE clause.  Each WHERE

  136326. ** clause subexpression is separated from the others by AND operators,

  136327. ** usually, or sometimes subexpressions separated by OR.

  136328. **

  136329. ** All WhereTerms are collected into a single WhereClause structure.  

  136330. ** The following identity holds:

  136331. **

  136332. **        WhereTerm.pWC->a[WhereTerm.idx] == WhereTerm

  136333. **

  136334. ** When a term is of the form:

  136335. **

  136336. **              X <op> <expr>

  136337. **

  136338. ** where X is a column name and <op> is one of certain operators,

  136339. ** then WhereTerm.leftCursor and WhereTerm.u.leftColumn record the

  136340. ** cursor number and column number for X.  WhereTerm.eOperator records

  136341. ** the <op> using a bitmask encoding defined by WO_xxx below.  The

  136342. ** use of a bitmask encoding for the operator allows us to search

  136343. ** quickly for terms that match any of several different operators.

  136344. **

  136345. ** A WhereTerm might also be two or more subterms connected by OR:

  136346. **

  136347. **         (t1.X <op> <expr>) OR (t1.Y <op> <expr>) OR ....

  136348. **

  136349. ** In this second case, wtFlag has the TERM_ORINFO bit set and eOperator==WO_OR

  136350. ** and the WhereTerm.u.pOrInfo field points to auxiliary information that

  136351. ** is collected about the OR clause.

  136352. **

  136353. ** If a term in the WHERE clause does not match either of the two previous

  136354. ** categories, then eOperator==0.  The WhereTerm.pExpr field is still set

  136355. ** to the original subexpression content and wtFlags is set up appropriately

  136356. ** but no other fields in the WhereTerm object are meaningful.

  136357. **

  136358. ** When eOperator!=0, prereqRight and prereqAll record sets of cursor numbers,

  136359. ** but they do so indirectly.  A single WhereMaskSet structure translates

  136360. ** cursor number into bits and the translated bit is stored in the prereq

  136361. ** fields.  The translation is used in order to maximize the number of

  136362. ** bits that will fit in a Bitmask.  The VDBE cursor numbers might be

  136363. ** spread out over the non-negative integers.  For example, the cursor

  136364. ** numbers might be 3, 8, 9, 10, 20, 23, 41, and 45.  The WhereMaskSet

  136365. ** translates these sparse cursor numbers into consecutive integers

  136366. ** beginning with 0 in order to make the best possible use of the available

  136367. ** bits in the Bitmask.  So, in the example above, the cursor numbers

  136368. ** would be mapped into integers 0 through 7.

  136369. **

  136370. ** The number of terms in a join is limited by the number of bits

  136371. ** in prereqRight and prereqAll.  The default is 64 bits, hence SQLite

  136372. ** is only able to process joins with 64 or fewer tables.

  136373. */

  136374. struct WhereTerm {

  136375.   Expr *pExpr;            /* Pointer to the subexpression that is this term */

  136376.   WhereClause *pWC;       /* The clause this term is part of */

  136377.   LogEst truthProb;       /* Probability of truth for this expression */

  136378.   u16 wtFlags;            /* TERM_xxx bit flags.  See below */

  136379.   u16 eOperator;          /* A WO_xx value describing <op> */

  136380.   u8 nChild;              /* Number of children that must disable us */

  136381.   u8 eMatchOp;            /* Op for vtab MATCH/LIKE/GLOB/REGEXP terms */

  136382.   int iParent;            /* Disable pWC->a[iParent] when this term disabled */

  136383.   int leftCursor;         /* Cursor number of X in "X <op> <expr>" */

  136384.   int iField;             /* Field in (?,?,?) IN (SELECT...) vector */

  136385.   union {

  136386.     int leftColumn;         /* Column number of X in "X <op> <expr>" */

  136387.     WhereOrInfo *pOrInfo;   /* Extra information if (eOperator & WO_OR)!=0 */

  136388.     WhereAndInfo *pAndInfo; /* Extra information if (eOperator& WO_AND)!=0 */

  136389.   } u;

  136390.   Bitmask prereqRight;    /* Bitmask of tables used by pExpr->pRight */

  136391.   Bitmask prereqAll;      /* Bitmask of tables referenced by pExpr */

  136392. };

  136393. 

  136394. /*

  136395. ** Allowed values of WhereTerm.wtFlags

  136396. */

  136397. #define TERM_DYNAMIC    0x01   /* Need to call sqlite3ExprDelete(db, pExpr) */

  136398. #define TERM_VIRTUAL    0x02   /* Added by the optimizer.  Do not code */

  136399. #define TERM_CODED      0x04   /* This term is already coded */

  136400. #define TERM_COPIED     0x08   /* Has a child */

  136401. #define TERM_ORINFO     0x10   /* Need to free the WhereTerm.u.pOrInfo object */

  136402. #define TERM_ANDINFO    0x20   /* Need to free the WhereTerm.u.pAndInfo obj */

  136403. #define TERM_OR_OK      0x40   /* Used during OR-clause processing */

  136404. #ifdef SQLITE_ENABLE_STAT3_OR_STAT4

  136405. #  define TERM_VNULL    0x80   /* Manufactured x>NULL or x<=NULL term */

  136406. #else

  136407. #  define TERM_VNULL    0x00   /* Disabled if not using stat3 */

  136408. #endif

  136409. #define TERM_LIKEOPT    0x100  /* Virtual terms from the LIKE optimization */

  136410. #define TERM_LIKECOND   0x200  /* Conditionally this LIKE operator term */

  136411. #define TERM_LIKE       0x400  /* The original LIKE operator */

  136412. #define TERM_IS         0x800  /* Term.pExpr is an IS operator */

  136413. #define TERM_VARSELECT  0x1000 /* Term.pExpr contains a correlated sub-query */

  136414. 

  136415. /*

  136416. ** An instance of the WhereScan object is used as an iterator for locating

  136417. ** terms in the WHERE clause that are useful to the query planner.

  136418. */

  136419. struct WhereScan {

  136420.   WhereClause *pOrigWC;      /* Original, innermost WhereClause */

  136421.   WhereClause *pWC;          /* WhereClause currently being scanned */

  136422.   const char *zCollName;     /* Required collating sequence, if not NULL */

  136423.   Expr *pIdxExpr;            /* Search for this index expression */

  136424.   char idxaff;               /* Must match this affinity, if zCollName!=NULL */

  136425.   unsigned char nEquiv;      /* Number of entries in aEquiv[] */

  136426.   unsigned char iEquiv;      /* Next unused slot in aEquiv[] */

  136427.   u32 opMask;                /* Acceptable operators */

  136428.   int k;                     /* Resume scanning at this->pWC->a[this->k] */

  136429.   int aiCur[11];             /* Cursors in the equivalence class */

  136430.   i16 aiColumn[11];          /* Corresponding column number in the eq-class */

  136431. };

  136432. 

  136433. /*

  136434. ** An instance of the following structure holds all information about a

  136435. ** WHERE clause.  Mostly this is a container for one or more WhereTerms.

  136436. **

  136437. ** Explanation of pOuter:  For a WHERE clause of the form

  136438. **

  136439. **           a AND ((b AND c) OR (d AND e)) AND f

  136440. **

  136441. ** There are separate WhereClause objects for the whole clause and for

  136442. ** the subclauses "(b AND c)" and "(d AND e)".  The pOuter field of the

  136443. ** subclauses points to the WhereClause object for the whole clause.

  136444. */

  136445. struct WhereClause {

  136446.   WhereInfo *pWInfo;       /* WHERE clause processing context */

  136447.   WhereClause *pOuter;     /* Outer conjunction */

  136448.   u8 op;                   /* Split operator.  TK_AND or TK_OR */

  136449.   u8 hasOr;                /* True if any a[].eOperator is WO_OR */

  136450.   int nTerm;               /* Number of terms */

  136451.   int nSlot;               /* Number of entries in a[] */

  136452.   WhereTerm *a;            /* Each a[] describes a term of the WHERE cluase */

  136453. #if defined(SQLITE_SMALL_STACK)

  136454.   WhereTerm aStatic[1];    /* Initial static space for a[] */

  136455. #else

  136456.   WhereTerm aStatic[8];    /* Initial static space for a[] */

  136457. #endif

  136458. };

  136459. 

  136460. /*

  136461. ** A WhereTerm with eOperator==WO_OR has its u.pOrInfo pointer set to

  136462. ** a dynamically allocated instance of the following structure.

  136463. */

  136464. struct WhereOrInfo {

  136465.   WhereClause wc;          /* Decomposition into subterms */

  136466.   Bitmask indexable;       /* Bitmask of all indexable tables in the clause */

  136467. };

  136468. 

  136469. /*

  136470. ** A WhereTerm with eOperator==WO_AND has its u.pAndInfo pointer set to

  136471. ** a dynamically allocated instance of the following structure.

  136472. */

  136473. struct WhereAndInfo {

  136474.   WhereClause wc;          /* The subexpression broken out */

  136475. };

  136476. 

  136477. /*

  136478. ** An instance of the following structure keeps track of a mapping

  136479. ** between VDBE cursor numbers and bits of the bitmasks in WhereTerm.

  136480. **

  136481. ** The VDBE cursor numbers are small integers contained in 

  136482. ** SrcList_item.iCursor and Expr.iTable fields.  For any given WHERE 

  136483. ** clause, the cursor numbers might not begin with 0 and they might

  136484. ** contain gaps in the numbering sequence.  But we want to make maximum

  136485. ** use of the bits in our bitmasks.  This structure provides a mapping

  136486. ** from the sparse cursor numbers into consecutive integers beginning

  136487. ** with 0.

  136488. **

  136489. ** If WhereMaskSet.ix[A]==B it means that The A-th bit of a Bitmask

  136490. ** corresponds VDBE cursor number B.  The A-th bit of a bitmask is 1<<A.

  136491. **

  136492. ** For example, if the WHERE clause expression used these VDBE

  136493. ** cursors:  4, 5, 8, 29, 57, 73.  Then the  WhereMaskSet structure

  136494. ** would map those cursor numbers into bits 0 through 5.

  136495. **

  136496. ** Note that the mapping is not necessarily ordered.  In the example

  136497. ** above, the mapping might go like this:  4->3, 5->1, 8->2, 29->0,

  136498. ** 57->5, 73->4.  Or one of 719 other combinations might be used. It

  136499. ** does not really matter.  What is important is that sparse cursor

  136500. ** numbers all get mapped into bit numbers that begin with 0 and contain

  136501. ** no gaps.

  136502. */

  136503. struct WhereMaskSet {

  136504.   int bVarSelect;               /* Used by sqlite3WhereExprUsage() */

  136505.   int n;                        /* Number of assigned cursor values */

  136506.   int ix[BMS];                  /* Cursor assigned to each bit */

  136507. };

  136508. 

  136509. /*

  136510. ** Initialize a WhereMaskSet object

  136511. */

  136512. #define initMaskSet(P)  (P)->n=0

  136513. 

  136514. /*

  136515. ** This object is a convenience wrapper holding all information needed

  136516. ** to construct WhereLoop objects for a particular query.

  136517. */

  136518. struct WhereLoopBuilder {

  136519.   WhereInfo *pWInfo;        /* Information about this WHERE */

  136520.   WhereClause *pWC;         /* WHERE clause terms */

  136521.   ExprList *pOrderBy;       /* ORDER BY clause */

  136522.   WhereLoop *pNew;          /* Template WhereLoop */

  136523.   WhereOrSet *pOrSet;       /* Record best loops here, if not NULL */

  136524. #ifdef SQLITE_ENABLE_STAT3_OR_STAT4

  136525.   UnpackedRecord *pRec;     /* Probe for stat4 (if required) */

  136526.   int nRecValid;            /* Number of valid fields currently in pRec */

  136527. #endif

  136528.   unsigned int bldFlags;    /* SQLITE_BLDF_* flags */

  136529.   unsigned int iPlanLimit;  /* Search limiter */

  136530. };

  136531. 

  136532. /* Allowed values for WhereLoopBuider.bldFlags */

  136533. #define SQLITE_BLDF_INDEXED  0x0001   /* An index is used */

  136534. #define SQLITE_BLDF_UNIQUE   0x0002   /* All keys of a UNIQUE index used */

  136535. 

  136536. /* The WhereLoopBuilder.iPlanLimit is used to limit the number of

  136537. ** index+constraint combinations the query planner will consider for a

  136538. ** particular query.  If this parameter is unlimited, then certain

  136539. ** pathological queries can spend excess time in the sqlite3WhereBegin()

  136540. ** routine.  The limit is high enough that is should not impact real-world

  136541. ** queries.

  136542. **

  136543. ** SQLITE_QUERY_PLANNER_LIMIT is the baseline limit.  The limit is

  136544. ** increased by SQLITE_QUERY_PLANNER_LIMIT_INCR before each term of the FROM

  136545. ** clause is processed, so that every table in a join is guaranteed to be

  136546. ** able to propose a some index+constraint combinations even if the initial

  136547. ** baseline limit was exhausted by prior tables of the join.

  136548. */

  136549. #ifndef SQLITE_QUERY_PLANNER_LIMIT

  136550. # define SQLITE_QUERY_PLANNER_LIMIT 20000

  136551. #endif

  136552. #ifndef SQLITE_QUERY_PLANNER_LIMIT_INCR

  136553. # define SQLITE_QUERY_PLANNER_LIMIT_INCR 1000

  136554. #endif

  136555. 

  136556. /*

  136557. ** The WHERE clause processing routine has two halves.  The

  136558. ** first part does the start of the WHERE loop and the second

  136559. ** half does the tail of the WHERE loop.  An instance of

  136560. ** this structure is returned by the first half and passed

  136561. ** into the second half to give some continuity.

  136562. **

  136563. ** An instance of this object holds the complete state of the query

  136564. ** planner.

  136565. */

  136566. struct WhereInfo {

  136567.   Parse *pParse;            /* Parsing and code generating context */

  136568.   SrcList *pTabList;        /* List of tables in the join */

  136569.   ExprList *pOrderBy;       /* The ORDER BY clause or NULL */

  136570.   ExprList *pResultSet;     /* Result set of the query */

  136571.   Expr *pWhere;             /* The complete WHERE clause */

  136572.   LogEst iLimit;            /* LIMIT if wctrlFlags has WHERE_USE_LIMIT */

  136573.   int aiCurOnePass[2];      /* OP_OpenWrite cursors for the ONEPASS opt */

  136574.   int iContinue;            /* Jump here to continue with next record */

  136575.   int iBreak;               /* Jump here to break out of the loop */

  136576.   int savedNQueryLoop;      /* pParse->nQueryLoop outside the WHERE loop */

  136577.   u16 wctrlFlags;           /* Flags originally passed to sqlite3WhereBegin() */

  136578.   u8 nLevel;                /* Number of nested loop */

  136579.   i8 nOBSat;                /* Number of ORDER BY terms satisfied by indices */

  136580.   u8 sorted;                /* True if really sorted (not just grouped) */

  136581.   u8 eOnePass;              /* ONEPASS_OFF, or _SINGLE, or _MULTI */

  136582.   u8 untestedTerms;         /* Not all WHERE terms resolved by outer loop */

  136583.   u8 eDistinct;             /* One of the WHERE_DISTINCT_* values */

  136584.   u8 bOrderedInnerLoop;     /* True if only the inner-most loop is ordered */

  136585.   int iTop;                 /* The very beginning of the WHERE loop */

  136586.   WhereLoop *pLoops;        /* List of all WhereLoop objects */

  136587.   Bitmask revMask;          /* Mask of ORDER BY terms that need reversing */

  136588.   LogEst nRowOut;           /* Estimated number of output rows */

  136589.   WhereClause sWC;          /* Decomposition of the WHERE clause */

  136590.   WhereMaskSet sMaskSet;    /* Map cursor numbers to bitmasks */

  136591.   WhereLevel a[1];          /* Information about each nest loop in WHERE */

  136592. };

  136593. 

  136594. /*

  136595. ** Private interfaces - callable only by other where.c routines.

  136596. **

  136597. ** where.c:

  136598. */

  136599. SQLITE_PRIVATE Bitmask sqlite3WhereGetMask(WhereMaskSet*,int);

  136600. #ifdef WHERETRACE_ENABLED

  136601. SQLITE_PRIVATE void sqlite3WhereClausePrint(WhereClause *pWC);

  136602. #endif

  136603. SQLITE_PRIVATE WhereTerm *sqlite3WhereFindTerm(

  136604.   WhereClause *pWC,     /* The WHERE clause to be searched */

  136605.   int iCur,             /* Cursor number of LHS */

  136606.   int iColumn,          /* Column number of LHS */

  136607.   Bitmask notReady,     /* RHS must not overlap with this mask */

  136608.   u32 op,               /* Mask of WO_xx values describing operator */

  136609.   Index *pIdx           /* Must be compatible with this index, if not NULL */

  136610. );

  136611. 

  136612. /* wherecode.c: */

  136613. #ifndef SQLITE_OMIT_EXPLAIN

  136614. SQLITE_PRIVATE int sqlite3WhereExplainOneScan(

  136615.   Parse *pParse,                  /* Parse context */

  136616.   SrcList *pTabList,              /* Table list this loop refers to */

  136617.   WhereLevel *pLevel,             /* Scan to write OP_Explain opcode for */

  136618.   u16 wctrlFlags                  /* Flags passed to sqlite3WhereBegin() */

  136619. );

  136620. #else

  136621. # define sqlite3WhereExplainOneScan(u,v,w,x) 0

  136622. #endif /* SQLITE_OMIT_EXPLAIN */

  136623. #ifdef SQLITE_ENABLE_STMT_SCANSTATUS

  136624. SQLITE_PRIVATE void sqlite3WhereAddScanStatus(

  136625.   Vdbe *v,                        /* Vdbe to add scanstatus entry to */

  136626.   SrcList *pSrclist,              /* FROM clause pLvl reads data from */

  136627.   WhereLevel *pLvl,               /* Level to add scanstatus() entry for */

  136628.   int addrExplain                 /* Address of OP_Explain (or 0) */

  136629. );

  136630. #else

  136631. # define sqlite3WhereAddScanStatus(a, b, c, d) ((void)d)

  136632. #endif

  136633. SQLITE_PRIVATE Bitmask sqlite3WhereCodeOneLoopStart(

  136634.   Parse *pParse,       /* Parsing context */

  136635.   Vdbe *v,             /* Prepared statement under construction */

  136636.   WhereInfo *pWInfo,   /* Complete information about the WHERE clause */

  136637.   int iLevel,          /* Which level of pWInfo->a[] should be coded */

  136638.   WhereLevel *pLevel,  /* The current level pointer */

  136639.   Bitmask notReady     /* Which tables are currently available */

  136640. );

  136641. 

  136642. /* whereexpr.c: */

  136643. SQLITE_PRIVATE void sqlite3WhereClauseInit(WhereClause*,WhereInfo*);

  136644. SQLITE_PRIVATE void sqlite3WhereClauseClear(WhereClause*);

  136645. SQLITE_PRIVATE void sqlite3WhereSplit(WhereClause*,Expr*,u8);

  136646. SQLITE_PRIVATE Bitmask sqlite3WhereExprUsage(WhereMaskSet*, Expr*);

  136647. SQLITE_PRIVATE Bitmask sqlite3WhereExprUsageNN(WhereMaskSet*, Expr*);

  136648. SQLITE_PRIVATE Bitmask sqlite3WhereExprListUsage(WhereMaskSet*, ExprList*);

  136649. SQLITE_PRIVATE void sqlite3WhereExprAnalyze(SrcList*, WhereClause*);

  136650. SQLITE_PRIVATE void sqlite3WhereTabFuncArgs(Parse*, struct SrcList_item*, WhereClause*);

  136651. 

  136652. 

  136653. 

  136654. 

  136655. 

  136656. /*

  136657. ** Bitmasks for the operators on WhereTerm objects.  These are all

  136658. ** operators that are of interest to the query planner.  An

  136659. ** OR-ed combination of these values can be used when searching for

  136660. ** particular WhereTerms within a WhereClause.

  136661. **

  136662. ** Value constraints:

  136663. **     WO_EQ    == SQLITE_INDEX_CONSTRAINT_EQ

  136664. **     WO_LT    == SQLITE_INDEX_CONSTRAINT_LT

  136665. **     WO_LE    == SQLITE_INDEX_CONSTRAINT_LE

  136666. **     WO_GT    == SQLITE_INDEX_CONSTRAINT_GT

  136667. **     WO_GE    == SQLITE_INDEX_CONSTRAINT_GE

  136668. */

  136669. #define WO_IN     0x0001

  136670. #define WO_EQ     0x0002

  136671. #define WO_LT     (WO_EQ<<(TK_LT-TK_EQ))

  136672. #define WO_LE     (WO_EQ<<(TK_LE-TK_EQ))

  136673. #define WO_GT     (WO_EQ<<(TK_GT-TK_EQ))

  136674. #define WO_GE     (WO_EQ<<(TK_GE-TK_EQ))

  136675. #define WO_AUX    0x0040       /* Op useful to virtual tables only */

  136676. #define WO_IS     0x0080

  136677. #define WO_ISNULL 0x0100

  136678. #define WO_OR     0x0200       /* Two or more OR-connected terms */

  136679. #define WO_AND    0x0400       /* Two or more AND-connected terms */

  136680. #define WO_EQUIV  0x0800       /* Of the form A==B, both columns */

  136681. #define WO_NOOP   0x1000       /* This term does not restrict search space */

  136682. 

  136683. #define WO_ALL    0x1fff       /* Mask of all possible WO_* values */

  136684. #define WO_SINGLE 0x01ff       /* Mask of all non-compound WO_* values */

  136685. 

  136686. /*

  136687. ** These are definitions of bits in the WhereLoop.wsFlags field.

  136688. ** The particular combination of bits in each WhereLoop help to

  136689. ** determine the algorithm that WhereLoop represents.

  136690. */

  136691. #define WHERE_COLUMN_EQ    0x00000001  /* x=EXPR */

  136692. #define WHERE_COLUMN_RANGE 0x00000002  /* x<EXPR and/or x>EXPR */

  136693. #define WHERE_COLUMN_IN    0x00000004  /* x IN (...) */

  136694. #define WHERE_COLUMN_NULL  0x00000008  /* x IS NULL */

  136695. #define WHERE_CONSTRAINT   0x0000000f  /* Any of the WHERE_COLUMN_xxx values */

  136696. #define WHERE_TOP_LIMIT    0x00000010  /* x<EXPR or x<=EXPR constraint */

  136697. #define WHERE_BTM_LIMIT    0x00000020  /* x>EXPR or x>=EXPR constraint */

  136698. #define WHERE_BOTH_LIMIT   0x00000030  /* Both x>EXPR and x<EXPR */

  136699. #define WHERE_IDX_ONLY     0x00000040  /* Use index only - omit table */

  136700. #define WHERE_IPK          0x00000100  /* x is the INTEGER PRIMARY KEY */

  136701. #define WHERE_INDEXED      0x00000200  /* WhereLoop.u.btree.pIndex is valid */

  136702. #define WHERE_VIRTUALTABLE 0x00000400  /* WhereLoop.u.vtab is valid */

  136703. #define WHERE_IN_ABLE      0x00000800  /* Able to support an IN operator */

  136704. #define WHERE_ONEROW       0x00001000  /* Selects no more than one row */

  136705. #define WHERE_MULTI_OR     0x00002000  /* OR using multiple indices */

  136706. #define WHERE_AUTO_INDEX   0x00004000  /* Uses an ephemeral index */

  136707. #define WHERE_SKIPSCAN     0x00008000  /* Uses the skip-scan algorithm */

  136708. #define WHERE_UNQ_WANTED   0x00010000  /* WHERE_ONEROW would have been helpful*/

  136709. #define WHERE_PARTIALIDX   0x00020000  /* The automatic index is partial */

  136710. #define WHERE_IN_EARLYOUT  0x00040000  /* Perhaps quit IN loops early */

  136711. 

  136712. #endif /* !defined(SQLITE_WHEREINT_H) */

  136713. 

  136714. /************** End of whereInt.h ********************************************/

  136715. /************** Continuing where we left off in wherecode.c ******************/

  136716. 

  136717. #ifndef SQLITE_OMIT_EXPLAIN

  136718. 

  136719. /*

  136720. ** Return the name of the i-th column of the pIdx index.

  136721. */

  136722. static const char *explainIndexColumnName(Index *pIdx, int i){

  136723.   i = pIdx->aiColumn[i];

  136724.   if( i==XN_EXPR ) return "<expr>";

  136725.   if( i==XN_ROWID ) return "rowid";

  136726.   return pIdx->pTable->aCol[i].zName;

  136727. }

  136728. 

  136729. /*

  136730. ** This routine is a helper for explainIndexRange() below

  136731. **

  136732. ** pStr holds the text of an expression that we are building up one term

  136733. ** at a time.  This routine adds a new term to the end of the expression.

  136734. ** Terms are separated by AND so add the "AND" text for second and subsequent

  136735. ** terms only.

  136736. */

  136737. static void explainAppendTerm(

  136738.   StrAccum *pStr,             /* The text expression being built */

  136739.   Index *pIdx,                /* Index to read column names from */

  136740.   int nTerm,                  /* Number of terms */

  136741.   int iTerm,                  /* Zero-based index of first term. */

  136742.   int bAnd,                   /* Non-zero to append " AND " */

  136743.   const char *zOp             /* Name of the operator */

  136744. ){

  136745.   int i;

  136746. 

  136747.   assert( nTerm>=1 );

  136748.   if( bAnd ) sqlite3_str_append(pStr, " AND ", 5);

  136749. 

  136750.   if( nTerm>1 ) sqlite3_str_append(pStr, "(", 1);

  136751.   for(i=0; i<nTerm; i++){

  136752.     if( i ) sqlite3_str_append(pStr, ",", 1);

  136753.     sqlite3_str_appendall(pStr, explainIndexColumnName(pIdx, iTerm+i));

  136754.   }

  136755.   if( nTerm>1 ) sqlite3_str_append(pStr, ")", 1);

  136756. 

  136757.   sqlite3_str_append(pStr, zOp, 1);

  136758. 

  136759.   if( nTerm>1 ) sqlite3_str_append(pStr, "(", 1);

  136760.   for(i=0; i<nTerm; i++){

  136761.     if( i ) sqlite3_str_append(pStr, ",", 1);

  136762.     sqlite3_str_append(pStr, "?", 1);

  136763.   }

  136764.   if( nTerm>1 ) sqlite3_str_append(pStr, ")", 1);

  136765. }

  136766. 

  136767. /*

  136768. ** Argument pLevel describes a strategy for scanning table pTab. This 

  136769. ** function appends text to pStr that describes the subset of table

  136770. ** rows scanned by the strategy in the form of an SQL expression.

  136771. **

  136772. ** For example, if the query:

  136773. **

  136774. **   SELECT * FROM t1 WHERE a=1 AND b>2;

  136775. **

  136776. ** is run and there is an index on (a, b), then this function returns a

  136777. ** string similar to:

  136778. **

  136779. **   "a=? AND b>?"

  136780. */

  136781. static void explainIndexRange(StrAccum *pStr, WhereLoop *pLoop){

  136782.   Index *pIndex = pLoop->u.btree.pIndex;

  136783.   u16 nEq = pLoop->u.btree.nEq;

  136784.   u16 nSkip = pLoop->nSkip;

  136785.   int i, j;

  136786. 

  136787.   if( nEq==0 && (pLoop->wsFlags&(WHERE_BTM_LIMIT|WHERE_TOP_LIMIT))==0 ) return;

  136788.   sqlite3_str_append(pStr, " (", 2);

  136789.   for(i=0; i<nEq; i++){

  136790.     const char *z = explainIndexColumnName(pIndex, i);

  136791.     if( i ) sqlite3_str_append(pStr, " AND ", 5);

  136792.     sqlite3_str_appendf(pStr, i>=nSkip ? "%s=?" : "ANY(%s)", z);

  136793.   }

  136794. 

  136795.   j = i;

  136796.   if( pLoop->wsFlags&WHERE_BTM_LIMIT ){

  136797.     explainAppendTerm(pStr, pIndex, pLoop->u.btree.nBtm, j, i, ">");

  136798.     i = 1;

  136799.   }

  136800.   if( pLoop->wsFlags&WHERE_TOP_LIMIT ){

  136801.     explainAppendTerm(pStr, pIndex, pLoop->u.btree.nTop, j, i, "<");

  136802.   }

  136803.   sqlite3_str_append(pStr, ")", 1);

  136804. }

  136805. 

  136806. /*

  136807. ** This function is a no-op unless currently processing an EXPLAIN QUERY PLAN

  136808. ** command, or if either SQLITE_DEBUG or SQLITE_ENABLE_STMT_SCANSTATUS was

  136809. ** defined at compile-time. If it is not a no-op, a single OP_Explain opcode 

  136810. ** is added to the output to describe the table scan strategy in pLevel.

  136811. **

  136812. ** If an OP_Explain opcode is added to the VM, its address is returned.

  136813. ** Otherwise, if no OP_Explain is coded, zero is returned.

  136814. */

  136815. SQLITE_PRIVATE int sqlite3WhereExplainOneScan(

  136816.   Parse *pParse,                  /* Parse context */

  136817.   SrcList *pTabList,              /* Table list this loop refers to */

  136818.   WhereLevel *pLevel,             /* Scan to write OP_Explain opcode for */

  136819.   u16 wctrlFlags                  /* Flags passed to sqlite3WhereBegin() */

  136820. ){

  136821.   int ret = 0;

  136822. #if !defined(SQLITE_DEBUG) && !defined(SQLITE_ENABLE_STMT_SCANSTATUS)

  136823.   if( sqlite3ParseToplevel(pParse)->explain==2 )

  136824. #endif

  136825.   {

  136826.     struct SrcList_item *pItem = &pTabList->a[pLevel->iFrom];

  136827.     Vdbe *v = pParse->pVdbe;      /* VM being constructed */

  136828.     sqlite3 *db = pParse->db;     /* Database handle */

  136829.     int isSearch;                 /* True for a SEARCH. False for SCAN. */

  136830.     WhereLoop *pLoop;             /* The controlling WhereLoop object */

  136831.     u32 flags;                    /* Flags that describe this loop */

  136832.     char *zMsg;                   /* Text to add to EQP output */

  136833.     StrAccum str;                 /* EQP output string */

  136834.     char zBuf[100];               /* Initial space for EQP output string */

  136835. 

  136836.     pLoop = pLevel->pWLoop;

  136837.     flags = pLoop->wsFlags;

  136838.     if( (flags&WHERE_MULTI_OR) || (wctrlFlags&WHERE_OR_SUBCLAUSE) ) return 0;

  136839. 

  136840.     isSearch = (flags&(WHERE_BTM_LIMIT|WHERE_TOP_LIMIT))!=0

  136841.             || ((flags&WHERE_VIRTUALTABLE)==0 && (pLoop->u.btree.nEq>0))

  136842.             || (wctrlFlags&(WHERE_ORDERBY_MIN|WHERE_ORDERBY_MAX));

  136843. 

  136844.     sqlite3StrAccumInit(&str, db, zBuf, sizeof(zBuf), SQLITE_MAX_LENGTH);

  136845.     sqlite3_str_appendall(&str, isSearch ? "SEARCH" : "SCAN");

  136846.     if( pItem->pSelect ){

  136847.       sqlite3_str_appendf(&str, " SUBQUERY %u", pItem->pSelect->selId);

  136848.     }else{

  136849.       sqlite3_str_appendf(&str, " TABLE %s", pItem->zName);

  136850.     }

  136851. 

  136852.     if( pItem->zAlias ){

  136853.       sqlite3_str_appendf(&str, " AS %s", pItem->zAlias);

  136854.     }

  136855.     if( (flags & (WHERE_IPK|WHERE_VIRTUALTABLE))==0 ){

  136856.       const char *zFmt = 0;

  136857.       Index *pIdx;

  136858. 

  136859.       assert( pLoop->u.btree.pIndex!=0 );

  136860.       pIdx = pLoop->u.btree.pIndex;

  136861.       assert( !(flags&WHERE_AUTO_INDEX) || (flags&WHERE_IDX_ONLY) );

  136862.       if( !HasRowid(pItem->pTab) && IsPrimaryKeyIndex(pIdx) ){

  136863.         if( isSearch ){

  136864.           zFmt = "PRIMARY KEY";

  136865.         }

  136866.       }else if( flags & WHERE_PARTIALIDX ){

  136867.         zFmt = "AUTOMATIC PARTIAL COVERING INDEX";

  136868.       }else if( flags & WHERE_AUTO_INDEX ){

  136869.         zFmt = "AUTOMATIC COVERING INDEX";

  136870.       }else if( flags & WHERE_IDX_ONLY ){

  136871.         zFmt = "COVERING INDEX %s";

  136872.       }else{

  136873.         zFmt = "INDEX %s";

  136874.       }

  136875.       if( zFmt ){

  136876.         sqlite3_str_append(&str, " USING ", 7);

  136877.         sqlite3_str_appendf(&str, zFmt, pIdx->zName);

  136878.         explainIndexRange(&str, pLoop);

  136879.       }

  136880.     }else if( (flags & WHERE_IPK)!=0 && (flags & WHERE_CONSTRAINT)!=0 ){

  136881.       const char *zRangeOp;

  136882.       if( flags&(WHERE_COLUMN_EQ|WHERE_COLUMN_IN) ){

  136883.         zRangeOp = "=";

  136884.       }else if( (flags&WHERE_BOTH_LIMIT)==WHERE_BOTH_LIMIT ){

  136885.         zRangeOp = ">? AND rowid<";

  136886.       }else if( flags&WHERE_BTM_LIMIT ){

  136887.         zRangeOp = ">";

  136888.       }else{

  136889.         assert( flags&WHERE_TOP_LIMIT);

  136890.         zRangeOp = "<";

  136891.       }

  136892.       sqlite3_str_appendf(&str, 

  136893.           " USING INTEGER PRIMARY KEY (rowid%s?)",zRangeOp);

  136894.     }

  136895. #ifndef SQLITE_OMIT_VIRTUALTABLE

  136896.     else if( (flags & WHERE_VIRTUALTABLE)!=0 ){

  136897.       sqlite3_str_appendf(&str, " VIRTUAL TABLE INDEX %d:%s",

  136898.                   pLoop->u.vtab.idxNum, pLoop->u.vtab.idxStr);

  136899.     }

  136900. #endif

  136901. #ifdef SQLITE_EXPLAIN_ESTIMATED_ROWS

  136902.     if( pLoop->nOut>=10 ){

  136903.       sqlite3_str_appendf(&str, " (~%llu rows)",

  136904.              sqlite3LogEstToInt(pLoop->nOut));

  136905.     }else{

  136906.       sqlite3_str_append(&str, " (~1 row)", 9);

  136907.     }

  136908. #endif

  136909.     zMsg = sqlite3StrAccumFinish(&str);

  136910.     sqlite3ExplainBreakpoint("",zMsg);

  136911.     ret = sqlite3VdbeAddOp4(v, OP_Explain, sqlite3VdbeCurrentAddr(v),

  136912.                             pParse->addrExplain, 0, zMsg,P4_DYNAMIC);

  136913.   }

  136914.   return ret;

  136915. }

  136916. #endif /* SQLITE_OMIT_EXPLAIN */

  136917. 

  136918. #ifdef SQLITE_ENABLE_STMT_SCANSTATUS

  136919. /*

  136920. ** Configure the VM passed as the first argument with an

  136921. ** sqlite3_stmt_scanstatus() entry corresponding to the scan used to 

  136922. ** implement level pLvl. Argument pSrclist is a pointer to the FROM 

  136923. ** clause that the scan reads data from.

  136924. **

  136925. ** If argument addrExplain is not 0, it must be the address of an 

  136926. ** OP_Explain instruction that describes the same loop.

  136927. */

  136928. SQLITE_PRIVATE void sqlite3WhereAddScanStatus(

  136929.   Vdbe *v,                        /* Vdbe to add scanstatus entry to */

  136930.   SrcList *pSrclist,              /* FROM clause pLvl reads data from */

  136931.   WhereLevel *pLvl,               /* Level to add scanstatus() entry for */

  136932.   int addrExplain                 /* Address of OP_Explain (or 0) */

  136933. ){

  136934.   const char *zObj = 0;

  136935.   WhereLoop *pLoop = pLvl->pWLoop;

  136936.   if( (pLoop->wsFlags & WHERE_VIRTUALTABLE)==0  &&  pLoop->u.btree.pIndex!=0 ){

  136937.     zObj = pLoop->u.btree.pIndex->zName;

  136938.   }else{

  136939.     zObj = pSrclist->a[pLvl->iFrom].zName;

  136940.   }

  136941.   sqlite3VdbeScanStatus(

  136942.       v, addrExplain, pLvl->addrBody, pLvl->addrVisit, pLoop->nOut, zObj

  136943.   );

  136944. }

  136945. #endif

  136946. 

  136947. 

  136948. /*

  136949. ** Disable a term in the WHERE clause.  Except, do not disable the term

  136950. ** if it controls a LEFT OUTER JOIN and it did not originate in the ON

  136951. ** or USING clause of that join.

  136952. **

  136953. ** Consider the term t2.z='ok' in the following queries:

  136954. **

  136955. **   (1)  SELECT * FROM t1 LEFT JOIN t2 ON t1.a=t2.x WHERE t2.z='ok'

  136956. **   (2)  SELECT * FROM t1 LEFT JOIN t2 ON t1.a=t2.x AND t2.z='ok'

  136957. **   (3)  SELECT * FROM t1, t2 WHERE t1.a=t2.x AND t2.z='ok'

  136958. **

  136959. ** The t2.z='ok' is disabled in the in (2) because it originates

  136960. ** in the ON clause.  The term is disabled in (3) because it is not part

  136961. ** of a LEFT OUTER JOIN.  In (1), the term is not disabled.

  136962. **

  136963. ** Disabling a term causes that term to not be tested in the inner loop

  136964. ** of the join.  Disabling is an optimization.  When terms are satisfied

  136965. ** by indices, we disable them to prevent redundant tests in the inner

  136966. ** loop.  We would get the correct results if nothing were ever disabled,

  136967. ** but joins might run a little slower.  The trick is to disable as much

  136968. ** as we can without disabling too much.  If we disabled in (1), we'd get

  136969. ** the wrong answer.  See ticket #813.

  136970. **

  136971. ** If all the children of a term are disabled, then that term is also

  136972. ** automatically disabled.  In this way, terms get disabled if derived

  136973. ** virtual terms are tested first.  For example:

  136974. **

  136975. **      x GLOB 'abc*' AND x>='abc' AND x<'acd'

  136976. **      \___________/     \______/     \_____/

  136977. **         parent          child1       child2

  136978. **

  136979. ** Only the parent term was in the original WHERE clause.  The child1

  136980. ** and child2 terms were added by the LIKE optimization.  If both of

  136981. ** the virtual child terms are valid, then testing of the parent can be 

  136982. ** skipped.

  136983. **

  136984. ** Usually the parent term is marked as TERM_CODED.  But if the parent

  136985. ** term was originally TERM_LIKE, then the parent gets TERM_LIKECOND instead.

  136986. ** The TERM_LIKECOND marking indicates that the term should be coded inside

  136987. ** a conditional such that is only evaluated on the second pass of a

  136988. ** LIKE-optimization loop, when scanning BLOBs instead of strings.

  136989. */

  136990. static void disableTerm(WhereLevel *pLevel, WhereTerm *pTerm){

  136991.   int nLoop = 0;

  136992.   assert( pTerm!=0 );

  136993.   while( (pTerm->wtFlags & TERM_CODED)==0

  136994.       && (pLevel->iLeftJoin==0 || ExprHasProperty(pTerm->pExpr, EP_FromJoin))

  136995.       && (pLevel->notReady & pTerm->prereqAll)==0

  136996.   ){

  136997.     if( nLoop && (pTerm->wtFlags & TERM_LIKE)!=0 ){

  136998.       pTerm->wtFlags |= TERM_LIKECOND;

  136999.     }else{

  137000.       pTerm->wtFlags |= TERM_CODED;

  137001.     }

  137002.     if( pTerm->iParent<0 ) break;

  137003.     pTerm = &pTerm->pWC->a[pTerm->iParent];

  137004.     assert( pTerm!=0 );

  137005.     pTerm->nChild--;

  137006.     if( pTerm->nChild!=0 ) break;

  137007.     nLoop++;

  137008.   }

  137009. }

  137010. 

  137011. /*

  137012. ** Code an OP_Affinity opcode to apply the column affinity string zAff

  137013. ** to the n registers starting at base. 

  137014. **

  137015. ** As an optimization, SQLITE_AFF_BLOB entries (which are no-ops) at the

  137016. ** beginning and end of zAff are ignored.  If all entries in zAff are

  137017. ** SQLITE_AFF_BLOB, then no code gets generated.

  137018. **

  137019. ** This routine makes its own copy of zAff so that the caller is free

  137020. ** to modify zAff after this routine returns.

  137021. */

  137022. static void codeApplyAffinity(Parse *pParse, int base, int n, char *zAff){

  137023.   Vdbe *v = pParse->pVdbe;

  137024.   if( zAff==0 ){

  137025.     assert( pParse->db->mallocFailed );

  137026.     return;

  137027.   }

  137028.   assert( v!=0 );

  137029. 

  137030.   /* Adjust base and n to skip over SQLITE_AFF_BLOB entries at the beginning

  137031.   ** and end of the affinity string.

  137032.   */

  137033.   while( n>0 && zAff[0]==SQLITE_AFF_BLOB ){

  137034.     n--;

  137035.     base++;

  137036.     zAff++;

  137037.   }

  137038.   while( n>1 && zAff[n-1]==SQLITE_AFF_BLOB ){

  137039.     n--;

  137040.   }

  137041. 

  137042.   /* Code the OP_Affinity opcode if there is anything left to do. */

  137043.   if( n>0 ){

  137044.     sqlite3VdbeAddOp4(v, OP_Affinity, base, n, 0, zAff, n);

  137045.   }

  137046. }

  137047. 

  137048. /*

  137049. ** Expression pRight, which is the RHS of a comparison operation, is 

  137050. ** either a vector of n elements or, if n==1, a scalar expression.

  137051. ** Before the comparison operation, affinity zAff is to be applied

  137052. ** to the pRight values. This function modifies characters within the

  137053. ** affinity string to SQLITE_AFF_BLOB if either:

  137054. **

  137055. **   * the comparison will be performed with no affinity, or

  137056. **   * the affinity change in zAff is guaranteed not to change the value.

  137057. */

  137058. static void updateRangeAffinityStr(

  137059.   Expr *pRight,                   /* RHS of comparison */

  137060.   int n,                          /* Number of vector elements in comparison */

  137061.   char *zAff                      /* Affinity string to modify */

  137062. ){

  137063.   int i;

  137064.   for(i=0; i<n; i++){

  137065.     Expr *p = sqlite3VectorFieldSubexpr(pRight, i);

  137066.     if( sqlite3CompareAffinity(p, zAff[i])==SQLITE_AFF_BLOB

  137067.      || sqlite3ExprNeedsNoAffinityChange(p, zAff[i])

  137068.     ){

  137069.       zAff[i] = SQLITE_AFF_BLOB;

  137070.     }

  137071.   }

  137072. }

  137073. 

  137074. 

  137075. /*

  137076. ** pX is an expression of the form:  (vector) IN (SELECT ...)

  137077. ** In other words, it is a vector IN operator with a SELECT clause on the

  137078. ** LHS.  But not all terms in the vector are indexable and the terms might

  137079. ** not be in the correct order for indexing.

  137080. **

  137081. ** This routine makes a copy of the input pX expression and then adjusts

  137082. ** the vector on the LHS with corresponding changes to the SELECT so that

  137083. ** the vector contains only index terms and those terms are in the correct

  137084. ** order.  The modified IN expression is returned.  The caller is responsible

  137085. ** for deleting the returned expression.

  137086. **

  137087. ** Example:

  137088. **

  137089. **    CREATE TABLE t1(a,b,c,d,e,f);

  137090. **    CREATE INDEX t1x1 ON t1(e,c);

  137091. **    SELECT * FROM t1 WHERE (a,b,c,d,e) IN (SELECT v,w,x,y,z FROM t2)

  137092. **                           \_______________________________________/

  137093. **                                     The pX expression

  137094. **

  137095. ** Since only columns e and c can be used with the index, in that order,

  137096. ** the modified IN expression that is returned will be:

  137097. **

  137098. **        (e,c) IN (SELECT z,x FROM t2)

  137099. **

  137100. ** The reduced pX is different from the original (obviously) and thus is

  137101. ** only used for indexing, to improve performance.  The original unaltered

  137102. ** IN expression must also be run on each output row for correctness.

  137103. */

  137104. static Expr *removeUnindexableInClauseTerms(

  137105.   Parse *pParse,        /* The parsing context */

  137106.   int iEq,              /* Look at loop terms starting here */

  137107.   WhereLoop *pLoop,     /* The current loop */

  137108.   Expr *pX              /* The IN expression to be reduced */

  137109. ){

  137110.   sqlite3 *db = pParse->db;

  137111.   Expr *pNew = sqlite3ExprDup(db, pX, 0);

  137112.   if( db->mallocFailed==0 ){

  137113.     ExprList *pOrigRhs = pNew->x.pSelect->pEList;  /* Original unmodified RHS */

  137114.     ExprList *pOrigLhs = pNew->pLeft->x.pList;     /* Original unmodified LHS */

  137115.     ExprList *pRhs = 0;         /* New RHS after modifications */

  137116.     ExprList *pLhs = 0;         /* New LHS after mods */

  137117.     int i;                      /* Loop counter */

  137118.     Select *pSelect;            /* Pointer to the SELECT on the RHS */

  137119. 

  137120.     for(i=iEq; i<pLoop->nLTerm; i++){

  137121.       if( pLoop->aLTerm[i]->pExpr==pX ){

  137122.         int iField = pLoop->aLTerm[i]->iField - 1;

  137123.         if( pOrigRhs->a[iField].pExpr==0 ) continue; /* Duplicate PK column */

  137124.         pRhs = sqlite3ExprListAppend(pParse, pRhs, pOrigRhs->a[iField].pExpr);

  137125.         pOrigRhs->a[iField].pExpr = 0;

  137126.         assert( pOrigLhs->a[iField].pExpr!=0 );

  137127.         pLhs = sqlite3ExprListAppend(pParse, pLhs, pOrigLhs->a[iField].pExpr);

  137128.         pOrigLhs->a[iField].pExpr = 0;

  137129.       }

  137130.     }

  137131.     sqlite3ExprListDelete(db, pOrigRhs);

  137132.     sqlite3ExprListDelete(db, pOrigLhs);

  137133.     pNew->pLeft->x.pList = pLhs;

  137134.     pNew->x.pSelect->pEList = pRhs;

  137135.     if( pLhs && pLhs->nExpr==1 ){

  137136.       /* Take care here not to generate a TK_VECTOR containing only a

  137137.       ** single value. Since the parser never creates such a vector, some

  137138.       ** of the subroutines do not handle this case.  */

  137139.       Expr *p = pLhs->a[0].pExpr;

  137140.       pLhs->a[0].pExpr = 0;

  137141.       sqlite3ExprDelete(db, pNew->pLeft);

  137142.       pNew->pLeft = p;

  137143.     }

  137144.     pSelect = pNew->x.pSelect;

  137145.     if( pSelect->pOrderBy ){

  137146.       /* If the SELECT statement has an ORDER BY clause, zero the 

  137147.       ** iOrderByCol variables. These are set to non-zero when an 

  137148.       ** ORDER BY term exactly matches one of the terms of the 

  137149.       ** result-set. Since the result-set of the SELECT statement may

  137150.       ** have been modified or reordered, these variables are no longer 

  137151.       ** set correctly.  Since setting them is just an optimization, 

  137152.       ** it's easiest just to zero them here.  */

  137153.       ExprList *pOrderBy = pSelect->pOrderBy;

  137154.       for(i=0; i<pOrderBy->nExpr; i++){

  137155.         pOrderBy->a[i].u.x.iOrderByCol = 0;

  137156.       }

  137157.     }

  137158. 

  137159. #if 0

  137160.     printf("For indexing, change the IN expr:\n");

  137161.     sqlite3TreeViewExpr(0, pX, 0);

  137162.     printf("Into:\n");

  137163.     sqlite3TreeViewExpr(0, pNew, 0);

  137164. #endif

  137165.   }

  137166.   return pNew;

  137167. }

  137168. 

  137169. 

  137170. /*

  137171. ** Generate code for a single equality term of the WHERE clause.  An equality

  137172. ** term can be either X=expr or X IN (...).   pTerm is the term to be 

  137173. ** coded.

  137174. **

  137175. ** The current value for the constraint is left in a register, the index

  137176. ** of which is returned.  An attempt is made store the result in iTarget but

  137177. ** this is only guaranteed for TK_ISNULL and TK_IN constraints.  If the

  137178. ** constraint is a TK_EQ or TK_IS, then the current value might be left in

  137179. ** some other register and it is the caller's responsibility to compensate.

  137180. **

  137181. ** For a constraint of the form X=expr, the expression is evaluated in

  137182. ** straight-line code.  For constraints of the form X IN (...)

  137183. ** this routine sets up a loop that will iterate over all values of X.

  137184. */

  137185. static int codeEqualityTerm(

  137186.   Parse *pParse,      /* The parsing context */

  137187.   WhereTerm *pTerm,   /* The term of the WHERE clause to be coded */

  137188.   WhereLevel *pLevel, /* The level of the FROM clause we are working on */

  137189.   int iEq,            /* Index of the equality term within this level */

  137190.   int bRev,           /* True for reverse-order IN operations */

  137191.   int iTarget         /* Attempt to leave results in this register */

  137192. ){

  137193.   Expr *pX = pTerm->pExpr;

  137194.   Vdbe *v = pParse->pVdbe;

  137195.   int iReg;                  /* Register holding results */

  137196. 

  137197.   assert( pLevel->pWLoop->aLTerm[iEq]==pTerm );

  137198.   assert( iTarget>0 );

  137199.   if( pX->op==TK_EQ || pX->op==TK_IS ){

  137200.     iReg = sqlite3ExprCodeTarget(pParse, pX->pRight, iTarget);

  137201.   }else if( pX->op==TK_ISNULL ){

  137202.     iReg = iTarget;

  137203.     sqlite3VdbeAddOp2(v, OP_Null, 0, iReg);

  137204. #ifndef SQLITE_OMIT_SUBQUERY

  137205.   }else{

  137206.     int eType = IN_INDEX_NOOP;

  137207.     int iTab;

  137208.     struct InLoop *pIn;

  137209.     WhereLoop *pLoop = pLevel->pWLoop;

  137210.     int i;

  137211.     int nEq = 0;

  137212.     int *aiMap = 0;

  137213. 

  137214.     if( (pLoop->wsFlags & WHERE_VIRTUALTABLE)==0

  137215.       && pLoop->u.btree.pIndex!=0

  137216.       && pLoop->u.btree.pIndex->aSortOrder[iEq]

  137217.     ){

  137218.       testcase( iEq==0 );

  137219.       testcase( bRev );

  137220.       bRev = !bRev;

  137221.     }

  137222.     assert( pX->op==TK_IN );

  137223.     iReg = iTarget;

  137224. 

  137225.     for(i=0; i<iEq; i++){

  137226.       if( pLoop->aLTerm[i] && pLoop->aLTerm[i]->pExpr==pX ){

  137227.         disableTerm(pLevel, pTerm);

  137228.         return iTarget;

  137229.       }

  137230.     }

  137231.     for(i=iEq;i<pLoop->nLTerm; i++){

  137232.       assert( pLoop->aLTerm[i]!=0 );

  137233.       if( pLoop->aLTerm[i]->pExpr==pX ) nEq++;

  137234.     }

  137235. 

  137236.     iTab = 0;

  137237.     if( (pX->flags & EP_xIsSelect)==0 || pX->x.pSelect->pEList->nExpr==1 ){

  137238.       eType = sqlite3FindInIndex(pParse, pX, IN_INDEX_LOOP, 0, 0, &iTab);

  137239.     }else{

  137240.       sqlite3 *db = pParse->db;

  137241.       pX = removeUnindexableInClauseTerms(pParse, iEq, pLoop, pX);

  137242. 

  137243.       if( !db->mallocFailed ){

  137244.         aiMap = (int*)sqlite3DbMallocZero(pParse->db, sizeof(int)*nEq);

  137245.         eType = sqlite3FindInIndex(pParse, pX, IN_INDEX_LOOP, 0, aiMap, &iTab);

  137246.         pTerm->pExpr->iTable = iTab;

  137247.       }

  137248.       sqlite3ExprDelete(db, pX);

  137249.       pX = pTerm->pExpr;

  137250.     }

  137251. 

  137252.     if( eType==IN_INDEX_INDEX_DESC ){

  137253.       testcase( bRev );

  137254.       bRev = !bRev;

  137255.     }

  137256.     sqlite3VdbeAddOp2(v, bRev ? OP_Last : OP_Rewind, iTab, 0);

  137257.     VdbeCoverageIf(v, bRev);

  137258.     VdbeCoverageIf(v, !bRev);

  137259.     assert( (pLoop->wsFlags & WHERE_MULTI_OR)==0 );

  137260. 

  137261.     pLoop->wsFlags |= WHERE_IN_ABLE;

  137262.     if( pLevel->u.in.nIn==0 ){

  137263.       pLevel->addrNxt = sqlite3VdbeMakeLabel(pParse);

  137264.     }

  137265. 

  137266.     i = pLevel->u.in.nIn;

  137267.     pLevel->u.in.nIn += nEq;

  137268.     pLevel->u.in.aInLoop =

  137269.        sqlite3DbReallocOrFree(pParse->db, pLevel->u.in.aInLoop,

  137270.                               sizeof(pLevel->u.in.aInLoop[0])*pLevel->u.in.nIn);

  137271.     pIn = pLevel->u.in.aInLoop;

  137272.     if( pIn ){

  137273.       int iMap = 0;               /* Index in aiMap[] */

  137274.       pIn += i;

  137275.       for(i=iEq;i<pLoop->nLTerm; i++){

  137276.         if( pLoop->aLTerm[i]->pExpr==pX ){

  137277.           int iOut = iReg + i - iEq;

  137278.           if( eType==IN_INDEX_ROWID ){

  137279.             pIn->addrInTop = sqlite3VdbeAddOp2(v, OP_Rowid, iTab, iOut);

  137280.           }else{

  137281.             int iCol = aiMap ? aiMap[iMap++] : 0;

  137282.             pIn->addrInTop = sqlite3VdbeAddOp3(v,OP_Column,iTab, iCol, iOut);

  137283.           }

  137284.           sqlite3VdbeAddOp1(v, OP_IsNull, iOut); VdbeCoverage(v);

  137285.           if( i==iEq ){

  137286.             pIn->iCur = iTab;

  137287.             pIn->eEndLoopOp = bRev ? OP_Prev : OP_Next;

  137288.             if( iEq>0 && (pLoop->wsFlags & WHERE_VIRTUALTABLE)==0 ){

  137289.               pIn->iBase = iReg - i;

  137290.               pIn->nPrefix = i;

  137291.               pLoop->wsFlags |= WHERE_IN_EARLYOUT;

  137292.             }else{

  137293.               pIn->nPrefix = 0;

  137294.             }

  137295.           }else{

  137296.             pIn->eEndLoopOp = OP_Noop;

  137297.           }

  137298.           pIn++;

  137299.         }

  137300.       }

  137301.     }else{

  137302.       pLevel->u.in.nIn = 0;

  137303.     }

  137304.     sqlite3DbFree(pParse->db, aiMap);

  137305. #endif

  137306.   }

  137307.   disableTerm(pLevel, pTerm);

  137308.   return iReg;

  137309. }

  137310. 

  137311. /*

  137312. ** Generate code that will evaluate all == and IN constraints for an

  137313. ** index scan.

  137314. **

  137315. ** For example, consider table t1(a,b,c,d,e,f) with index i1(a,b,c).

  137316. ** Suppose the WHERE clause is this:  a==5 AND b IN (1,2,3) AND c>5 AND c<10

  137317. ** The index has as many as three equality constraints, but in this

  137318. ** example, the third "c" value is an inequality.  So only two 

  137319. ** constraints are coded.  This routine will generate code to evaluate

  137320. ** a==5 and b IN (1,2,3).  The current values for a and b will be stored

  137321. ** in consecutive registers and the index of the first register is returned.

  137322. **

  137323. ** In the example above nEq==2.  But this subroutine works for any value

  137324. ** of nEq including 0.  If nEq==0, this routine is nearly a no-op.

  137325. ** The only thing it does is allocate the pLevel->iMem memory cell and

  137326. ** compute the affinity string.

  137327. **

  137328. ** The nExtraReg parameter is 0 or 1.  It is 0 if all WHERE clause constraints

  137329. ** are == or IN and are covered by the nEq.  nExtraReg is 1 if there is

  137330. ** an inequality constraint (such as the "c>=5 AND c<10" in the example) that

  137331. ** occurs after the nEq quality constraints.

  137332. **

  137333. ** This routine allocates a range of nEq+nExtraReg memory cells and returns

  137334. ** the index of the first memory cell in that range. The code that

  137335. ** calls this routine will use that memory range to store keys for

  137336. ** start and termination conditions of the loop.

  137337. ** key value of the loop.  If one or more IN operators appear, then

  137338. ** this routine allocates an additional nEq memory cells for internal

  137339. ** use.

  137340. **

  137341. ** Before returning, *pzAff is set to point to a buffer containing a

  137342. ** copy of the column affinity string of the index allocated using

  137343. ** sqlite3DbMalloc(). Except, entries in the copy of the string associated

  137344. ** with equality constraints that use BLOB or NONE affinity are set to

  137345. ** SQLITE_AFF_BLOB. This is to deal with SQL such as the following:

  137346. **

  137347. **   CREATE TABLE t1(a TEXT PRIMARY KEY, b);

  137348. **   SELECT ... FROM t1 AS t2, t1 WHERE t1.a = t2.b;

  137349. **

  137350. ** In the example above, the index on t1(a) has TEXT affinity. But since

  137351. ** the right hand side of the equality constraint (t2.b) has BLOB/NONE affinity,

  137352. ** no conversion should be attempted before using a t2.b value as part of

  137353. ** a key to search the index. Hence the first byte in the returned affinity

  137354. ** string in this example would be set to SQLITE_AFF_BLOB.

  137355. */

  137356. static int codeAllEqualityTerms(

  137357.   Parse *pParse,        /* Parsing context */

  137358.   WhereLevel *pLevel,   /* Which nested loop of the FROM we are coding */

  137359.   int bRev,             /* Reverse the order of IN operators */

  137360.   int nExtraReg,        /* Number of extra registers to allocate */

  137361.   char **pzAff          /* OUT: Set to point to affinity string */

  137362. ){

  137363.   u16 nEq;                      /* The number of == or IN constraints to code */

  137364.   u16 nSkip;                    /* Number of left-most columns to skip */

  137365.   Vdbe *v = pParse->pVdbe;      /* The vm under construction */

  137366.   Index *pIdx;                  /* The index being used for this loop */

  137367.   WhereTerm *pTerm;             /* A single constraint term */

  137368.   WhereLoop *pLoop;             /* The WhereLoop object */

  137369.   int j;                        /* Loop counter */

  137370.   int regBase;                  /* Base register */

  137371.   int nReg;                     /* Number of registers to allocate */

  137372.   char *zAff;                   /* Affinity string to return */

  137373. 

  137374.   /* This module is only called on query plans that use an index. */

  137375.   pLoop = pLevel->pWLoop;

  137376.   assert( (pLoop->wsFlags & WHERE_VIRTUALTABLE)==0 );

  137377.   nEq = pLoop->u.btree.nEq;

  137378.   nSkip = pLoop->nSkip;

  137379.   pIdx = pLoop->u.btree.pIndex;

  137380.   assert( pIdx!=0 );

  137381. 

  137382.   /* Figure out how many memory cells we will need then allocate them.

  137383.   */

  137384.   regBase = pParse->nMem + 1;

  137385.   nReg = pLoop->u.btree.nEq + nExtraReg;

  137386.   pParse->nMem += nReg;

  137387. 

  137388.   zAff = sqlite3DbStrDup(pParse->db,sqlite3IndexAffinityStr(pParse->db,pIdx));

  137389.   assert( zAff!=0 || pParse->db->mallocFailed );

  137390. 

  137391.   if( nSkip ){

  137392.     int iIdxCur = pLevel->iIdxCur;

  137393.     sqlite3VdbeAddOp1(v, (bRev?OP_Last:OP_Rewind), iIdxCur);

  137394.     VdbeCoverageIf(v, bRev==0);

  137395.     VdbeCoverageIf(v, bRev!=0);

  137396.     VdbeComment((v, "begin skip-scan on %s", pIdx->zName));

  137397.     j = sqlite3VdbeAddOp0(v, OP_Goto);

  137398.     pLevel->addrSkip = sqlite3VdbeAddOp4Int(v, (bRev?OP_SeekLT:OP_SeekGT),

  137399.                             iIdxCur, 0, regBase, nSkip);

  137400.     VdbeCoverageIf(v, bRev==0);

  137401.     VdbeCoverageIf(v, bRev!=0);

  137402.     sqlite3VdbeJumpHere(v, j);

  137403.     for(j=0; j<nSkip; j++){

  137404.       sqlite3VdbeAddOp3(v, OP_Column, iIdxCur, j, regBase+j);

  137405.       testcase( pIdx->aiColumn[j]==XN_EXPR );

  137406.       VdbeComment((v, "%s", explainIndexColumnName(pIdx, j)));

  137407.     }

  137408.   }    

  137409. 

  137410.   /* Evaluate the equality constraints

  137411.   */

  137412.   assert( zAff==0 || (int)strlen(zAff)>=nEq );

  137413.   for(j=nSkip; j<nEq; j++){

  137414.     int r1;

  137415.     pTerm = pLoop->aLTerm[j];

  137416.     assert( pTerm!=0 );

  137417.     /* The following testcase is true for indices with redundant columns. 

  137418.     ** Ex: CREATE INDEX i1 ON t1(a,b,a); SELECT * FROM t1 WHERE a=0 AND b=0; */

  137419.     testcase( (pTerm->wtFlags & TERM_CODED)!=0 );

  137420.     testcase( pTerm->wtFlags & TERM_VIRTUAL );

  137421.     r1 = codeEqualityTerm(pParse, pTerm, pLevel, j, bRev, regBase+j);

  137422.     if( r1!=regBase+j ){

  137423.       if( nReg==1 ){

  137424.         sqlite3ReleaseTempReg(pParse, regBase);

  137425.         regBase = r1;

  137426.       }else{

  137427.         sqlite3VdbeAddOp2(v, OP_SCopy, r1, regBase+j);

  137428.       }

  137429.     }

  137430.     if( pTerm->eOperator & WO_IN ){

  137431.       if( pTerm->pExpr->flags & EP_xIsSelect ){

  137432.         /* No affinity ever needs to be (or should be) applied to a value

  137433.         ** from the RHS of an "? IN (SELECT ...)" expression. The 

  137434.         ** sqlite3FindInIndex() routine has already ensured that the 

  137435.         ** affinity of the comparison has been applied to the value.  */

  137436.         if( zAff ) zAff[j] = SQLITE_AFF_BLOB;

  137437.       }

  137438.     }else if( (pTerm->eOperator & WO_ISNULL)==0 ){

  137439.       Expr *pRight = pTerm->pExpr->pRight;

  137440.       if( (pTerm->wtFlags & TERM_IS)==0 && sqlite3ExprCanBeNull(pRight) ){

  137441.         sqlite3VdbeAddOp2(v, OP_IsNull, regBase+j, pLevel->addrBrk);

  137442.         VdbeCoverage(v);

  137443.       }

  137444.       if( zAff ){

  137445.         if( sqlite3CompareAffinity(pRight, zAff[j])==SQLITE_AFF_BLOB ){

  137446.           zAff[j] = SQLITE_AFF_BLOB;

  137447.         }

  137448.         if( sqlite3ExprNeedsNoAffinityChange(pRight, zAff[j]) ){

  137449.           zAff[j] = SQLITE_AFF_BLOB;

  137450.         }

  137451.       }

  137452.     }

  137453.   }

  137454.   *pzAff = zAff;

  137455.   return regBase;

  137456. }

  137457. 

  137458. #ifndef SQLITE_LIKE_DOESNT_MATCH_BLOBS

  137459. /*

  137460. ** If the most recently coded instruction is a constant range constraint

  137461. ** (a string literal) that originated from the LIKE optimization, then 

  137462. ** set P3 and P5 on the OP_String opcode so that the string will be cast

  137463. ** to a BLOB at appropriate times.

  137464. **

  137465. ** The LIKE optimization trys to evaluate "x LIKE 'abc%'" as a range

  137466. ** expression: "x>='ABC' AND x<'abd'".  But this requires that the range

  137467. ** scan loop run twice, once for strings and a second time for BLOBs.

  137468. ** The OP_String opcodes on the second pass convert the upper and lower

  137469. ** bound string constants to blobs.  This routine makes the necessary changes

  137470. ** to the OP_String opcodes for that to happen.

  137471. **

  137472. ** Except, of course, if SQLITE_LIKE_DOESNT_MATCH_BLOBS is defined, then

  137473. ** only the one pass through the string space is required, so this routine

  137474. ** becomes a no-op.

  137475. */

  137476. static void whereLikeOptimizationStringFixup(

  137477.   Vdbe *v,                /* prepared statement under construction */

  137478.   WhereLevel *pLevel,     /* The loop that contains the LIKE operator */

  137479.   WhereTerm *pTerm        /* The upper or lower bound just coded */

  137480. ){

  137481.   if( pTerm->wtFlags & TERM_LIKEOPT ){

  137482.     VdbeOp *pOp;

  137483.     assert( pLevel->iLikeRepCntr>0 );

  137484.     pOp = sqlite3VdbeGetOp(v, -1);

  137485.     assert( pOp!=0 );

  137486.     assert( pOp->opcode==OP_String8 

  137487.             || pTerm->pWC->pWInfo->pParse->db->mallocFailed );

  137488.     pOp->p3 = (int)(pLevel->iLikeRepCntr>>1);  /* Register holding counter */

  137489.     pOp->p5 = (u8)(pLevel->iLikeRepCntr&1);    /* ASC or DESC */

  137490.   }

  137491. }

  137492. #else

  137493. # define whereLikeOptimizationStringFixup(A,B,C)

  137494. #endif

  137495. 

  137496. #ifdef SQLITE_ENABLE_CURSOR_HINTS

  137497. /*

  137498. ** Information is passed from codeCursorHint() down to individual nodes of

  137499. ** the expression tree (by sqlite3WalkExpr()) using an instance of this

  137500. ** structure.

  137501. */

  137502. struct CCurHint {

  137503.   int iTabCur;    /* Cursor for the main table */

  137504.   int iIdxCur;    /* Cursor for the index, if pIdx!=0.  Unused otherwise */

  137505.   Index *pIdx;    /* The index used to access the table */

  137506. };

  137507. 

  137508. /*

  137509. ** This function is called for every node of an expression that is a candidate

  137510. ** for a cursor hint on an index cursor.  For TK_COLUMN nodes that reference

  137511. ** the table CCurHint.iTabCur, verify that the same column can be

  137512. ** accessed through the index.  If it cannot, then set pWalker->eCode to 1.

  137513. */

  137514. static int codeCursorHintCheckExpr(Walker *pWalker, Expr *pExpr){

  137515.   struct CCurHint *pHint = pWalker->u.pCCurHint;

  137516.   assert( pHint->pIdx!=0 );

  137517.   if( pExpr->op==TK_COLUMN

  137518.    && pExpr->iTable==pHint->iTabCur

  137519.    && sqlite3ColumnOfIndex(pHint->pIdx, pExpr->iColumn)<0

  137520.   ){

  137521.     pWalker->eCode = 1;

  137522.   }

  137523.   return WRC_Continue;

  137524. }

  137525. 

  137526. /*

  137527. ** Test whether or not expression pExpr, which was part of a WHERE clause,

  137528. ** should be included in the cursor-hint for a table that is on the rhs

  137529. ** of a LEFT JOIN. Set Walker.eCode to non-zero before returning if the 

  137530. ** expression is not suitable.

  137531. **

  137532. ** An expression is unsuitable if it might evaluate to non NULL even if

  137533. ** a TK_COLUMN node that does affect the value of the expression is set

  137534. ** to NULL. For example:

  137535. **

  137536. **   col IS NULL

  137537. **   col IS NOT NULL

  137538. **   coalesce(col, 1)

  137539. **   CASE WHEN col THEN 0 ELSE 1 END

  137540. */

  137541. static int codeCursorHintIsOrFunction(Walker *pWalker, Expr *pExpr){

  137542.   if( pExpr->op==TK_IS 

  137543.    || pExpr->op==TK_ISNULL || pExpr->op==TK_ISNOT 

  137544.    || pExpr->op==TK_NOTNULL || pExpr->op==TK_CASE 

  137545.   ){

  137546.     pWalker->eCode = 1;

  137547.   }else if( pExpr->op==TK_FUNCTION ){

  137548.     int d1;

  137549.     char d2[4];

  137550.     if( 0==sqlite3IsLikeFunction(pWalker->pParse->db, pExpr, &d1, d2) ){

  137551.       pWalker->eCode = 1;

  137552.     }

  137553.   }

  137554. 

  137555.   return WRC_Continue;

  137556. }

  137557. 

  137558. 

  137559. /*

  137560. ** This function is called on every node of an expression tree used as an

  137561. ** argument to the OP_CursorHint instruction. If the node is a TK_COLUMN

  137562. ** that accesses any table other than the one identified by

  137563. ** CCurHint.iTabCur, then do the following:

  137564. **

  137565. **   1) allocate a register and code an OP_Column instruction to read 

  137566. **      the specified column into the new register, and

  137567. **

  137568. **   2) transform the expression node to a TK_REGISTER node that reads 

  137569. **      from the newly populated register.

  137570. **

  137571. ** Also, if the node is a TK_COLUMN that does access the table idenified

  137572. ** by pCCurHint.iTabCur, and an index is being used (which we will

  137573. ** know because CCurHint.pIdx!=0) then transform the TK_COLUMN into

  137574. ** an access of the index rather than the original table.

  137575. */

  137576. static int codeCursorHintFixExpr(Walker *pWalker, Expr *pExpr){

  137577.   int rc = WRC_Continue;

  137578.   struct CCurHint *pHint = pWalker->u.pCCurHint;

  137579.   if( pExpr->op==TK_COLUMN ){

  137580.     if( pExpr->iTable!=pHint->iTabCur ){

  137581.       int reg = ++pWalker->pParse->nMem;   /* Register for column value */

  137582.       sqlite3ExprCode(pWalker->pParse, pExpr, reg);

  137583.       pExpr->op = TK_REGISTER;

  137584.       pExpr->iTable = reg;

  137585.     }else if( pHint->pIdx!=0 ){

  137586.       pExpr->iTable = pHint->iIdxCur;

  137587.       pExpr->iColumn = sqlite3ColumnOfIndex(pHint->pIdx, pExpr->iColumn);

  137588.       assert( pExpr->iColumn>=0 );

  137589.     }

  137590.   }else if( pExpr->op==TK_AGG_FUNCTION ){

  137591.     /* An aggregate function in the WHERE clause of a query means this must

  137592.     ** be a correlated sub-query, and expression pExpr is an aggregate from

  137593.     ** the parent context. Do not walk the function arguments in this case.

  137594.     **

  137595.     ** todo: It should be possible to replace this node with a TK_REGISTER

  137596.     ** expression, as the result of the expression must be stored in a 

  137597.     ** register at this point. The same holds for TK_AGG_COLUMN nodes. */

  137598.     rc = WRC_Prune;

  137599.   }

  137600.   return rc;

  137601. }

  137602. 

  137603. /*

  137604. ** Insert an OP_CursorHint instruction if it is appropriate to do so.

  137605. */

  137606. static void codeCursorHint(

  137607.   struct SrcList_item *pTabItem,  /* FROM clause item */

  137608.   WhereInfo *pWInfo,    /* The where clause */

  137609.   WhereLevel *pLevel,   /* Which loop to provide hints for */

  137610.   WhereTerm *pEndRange  /* Hint this end-of-scan boundary term if not NULL */

  137611. ){

  137612.   Parse *pParse = pWInfo->pParse;

  137613.   sqlite3 *db = pParse->db;

  137614.   Vdbe *v = pParse->pVdbe;

  137615.   Expr *pExpr = 0;

  137616.   WhereLoop *pLoop = pLevel->pWLoop;

  137617.   int iCur;

  137618.   WhereClause *pWC;

  137619.   WhereTerm *pTerm;

  137620.   int i, j;

  137621.   struct CCurHint sHint;

  137622.   Walker sWalker;

  137623. 

  137624.   if( OptimizationDisabled(db, SQLITE_CursorHints) ) return;

  137625.   iCur = pLevel->iTabCur;

  137626.   assert( iCur==pWInfo->pTabList->a[pLevel->iFrom].iCursor );

  137627.   sHint.iTabCur = iCur;

  137628.   sHint.iIdxCur = pLevel->iIdxCur;

  137629.   sHint.pIdx = pLoop->u.btree.pIndex;

  137630.   memset(&sWalker, 0, sizeof(sWalker));

  137631.   sWalker.pParse = pParse;

  137632.   sWalker.u.pCCurHint = &sHint;

  137633.   pWC = &pWInfo->sWC;

  137634.   for(i=0; i<pWC->nTerm; i++){

  137635.     pTerm = &pWC->a[i];

  137636.     if( pTerm->wtFlags & (TERM_VIRTUAL|TERM_CODED) ) continue;

  137637.     if( pTerm->prereqAll & pLevel->notReady ) continue;

  137638. 

  137639.     /* Any terms specified as part of the ON(...) clause for any LEFT 

  137640.     ** JOIN for which the current table is not the rhs are omitted

  137641.     ** from the cursor-hint. 

  137642.     **

  137643.     ** If this table is the rhs of a LEFT JOIN, "IS" or "IS NULL" terms 

  137644.     ** that were specified as part of the WHERE clause must be excluded.

  137645.     ** This is to address the following:

  137646.     **

  137647.     **   SELECT ... t1 LEFT JOIN t2 ON (t1.a=t2.b) WHERE t2.c IS NULL;

  137648.     **

  137649.     ** Say there is a single row in t2 that matches (t1.a=t2.b), but its

  137650.     ** t2.c values is not NULL. If the (t2.c IS NULL) constraint is 

  137651.     ** pushed down to the cursor, this row is filtered out, causing

  137652.     ** SQLite to synthesize a row of NULL values. Which does match the

  137653.     ** WHERE clause, and so the query returns a row. Which is incorrect.

  137654.     **

  137655.     ** For the same reason, WHERE terms such as:

  137656.     **

  137657.     **   WHERE 1 = (t2.c IS NULL)

  137658.     **

  137659.     ** are also excluded. See codeCursorHintIsOrFunction() for details.

  137660.     */

  137661.     if( pTabItem->fg.jointype & JT_LEFT ){

  137662.       Expr *pExpr = pTerm->pExpr;

  137663.       if( !ExprHasProperty(pExpr, EP_FromJoin) 

  137664.        || pExpr->iRightJoinTable!=pTabItem->iCursor

  137665.       ){

  137666.         sWalker.eCode = 0;

  137667.         sWalker.xExprCallback = codeCursorHintIsOrFunction;

  137668.         sqlite3WalkExpr(&sWalker, pTerm->pExpr);

  137669.         if( sWalker.eCode ) continue;

  137670.       }

  137671.     }else{

  137672.       if( ExprHasProperty(pTerm->pExpr, EP_FromJoin) ) continue;

  137673.     }

  137674. 

  137675.     /* All terms in pWLoop->aLTerm[] except pEndRange are used to initialize

  137676.     ** the cursor.  These terms are not needed as hints for a pure range

  137677.     ** scan (that has no == terms) so omit them. */

  137678.     if( pLoop->u.btree.nEq==0 && pTerm!=pEndRange ){

  137679.       for(j=0; j<pLoop->nLTerm && pLoop->aLTerm[j]!=pTerm; j++){}

  137680.       if( j<pLoop->nLTerm ) continue;

  137681.     }

  137682. 

  137683.     /* No subqueries or non-deterministic functions allowed */

  137684.     if( sqlite3ExprContainsSubquery(pTerm->pExpr) ) continue;

  137685. 

  137686.     /* For an index scan, make sure referenced columns are actually in

  137687.     ** the index. */

  137688.     if( sHint.pIdx!=0 ){

  137689.       sWalker.eCode = 0;

  137690.       sWalker.xExprCallback = codeCursorHintCheckExpr;

  137691.       sqlite3WalkExpr(&sWalker, pTerm->pExpr);

  137692.       if( sWalker.eCode ) continue;

  137693.     }

  137694. 

  137695.     /* If we survive all prior tests, that means this term is worth hinting */

  137696.     pExpr = sqlite3ExprAnd(pParse, pExpr, sqlite3ExprDup(db, pTerm->pExpr, 0));

  137697.   }

  137698.   if( pExpr!=0 ){

  137699.     sWalker.xExprCallback = codeCursorHintFixExpr;

  137700.     sqlite3WalkExpr(&sWalker, pExpr);

  137701.     sqlite3VdbeAddOp4(v, OP_CursorHint, 

  137702.                       (sHint.pIdx ? sHint.iIdxCur : sHint.iTabCur), 0, 0,

  137703.                       (const char*)pExpr, P4_EXPR);

  137704.   }

  137705. }

  137706. #else

  137707. # define codeCursorHint(A,B,C,D)  /* No-op */

  137708. #endif /* SQLITE_ENABLE_CURSOR_HINTS */

  137709. 

  137710. /*

  137711. ** Cursor iCur is open on an intkey b-tree (a table). Register iRowid contains

  137712. ** a rowid value just read from cursor iIdxCur, open on index pIdx. This

  137713. ** function generates code to do a deferred seek of cursor iCur to the 

  137714. ** rowid stored in register iRowid.

  137715. **

  137716. ** Normally, this is just:

  137717. **

  137718. **   OP_DeferredSeek $iCur $iRowid

  137719. **

  137720. ** However, if the scan currently being coded is a branch of an OR-loop and

  137721. ** the statement currently being coded is a SELECT, then P3 of OP_DeferredSeek

  137722. ** is set to iIdxCur and P4 is set to point to an array of integers

  137723. ** containing one entry for each column of the table cursor iCur is open 

  137724. ** on. For each table column, if the column is the i'th column of the 

  137725. ** index, then the corresponding array entry is set to (i+1). If the column

  137726. ** does not appear in the index at all, the array entry is set to 0.

  137727. */

  137728. static void codeDeferredSeek(

  137729.   WhereInfo *pWInfo,              /* Where clause context */

  137730.   Index *pIdx,                    /* Index scan is using */

  137731.   int iCur,                       /* Cursor for IPK b-tree */

  137732.   int iIdxCur                     /* Index cursor */

  137733. ){

  137734.   Parse *pParse = pWInfo->pParse; /* Parse context */

  137735.   Vdbe *v = pParse->pVdbe;        /* Vdbe to generate code within */

  137736. 

  137737.   assert( iIdxCur>0 );

  137738.   assert( pIdx->aiColumn[pIdx->nColumn-1]==-1 );

  137739.   

  137740.   sqlite3VdbeAddOp3(v, OP_DeferredSeek, iIdxCur, 0, iCur);

  137741.   if( (pWInfo->wctrlFlags & WHERE_OR_SUBCLAUSE)

  137742.    && DbMaskAllZero(sqlite3ParseToplevel(pParse)->writeMask)

  137743.   ){

  137744.     int i;

  137745.     Table *pTab = pIdx->pTable;

  137746.     int *ai = (int*)sqlite3DbMallocZero(pParse->db, sizeof(int)*(pTab->nCol+1));

  137747.     if( ai ){

  137748.       ai[0] = pTab->nCol;

  137749.       for(i=0; i<pIdx->nColumn-1; i++){

  137750.         assert( pIdx->aiColumn[i]<pTab->nCol );

  137751.         if( pIdx->aiColumn[i]>=0 ) ai[pIdx->aiColumn[i]+1] = i+1;

  137752.       }

  137753.       sqlite3VdbeChangeP4(v, -1, (char*)ai, P4_INTARRAY);

  137754.     }

  137755.   }

  137756. }

  137757. 

  137758. /*

  137759. ** If the expression passed as the second argument is a vector, generate

  137760. ** code to write the first nReg elements of the vector into an array

  137761. ** of registers starting with iReg.

  137762. **

  137763. ** If the expression is not a vector, then nReg must be passed 1. In

  137764. ** this case, generate code to evaluate the expression and leave the

  137765. ** result in register iReg.

  137766. */

  137767. static void codeExprOrVector(Parse *pParse, Expr *p, int iReg, int nReg){

  137768.   assert( nReg>0 );

  137769.   if( p && sqlite3ExprIsVector(p) ){

  137770. #ifndef SQLITE_OMIT_SUBQUERY

  137771.     if( (p->flags & EP_xIsSelect) ){

  137772.       Vdbe *v = pParse->pVdbe;

  137773.       int iSelect;

  137774.       assert( p->op==TK_SELECT );

  137775.       iSelect = sqlite3CodeSubselect(pParse, p);

  137776.       sqlite3VdbeAddOp3(v, OP_Copy, iSelect, iReg, nReg-1);

  137777.     }else

  137778. #endif

  137779.     {

  137780.       int i;

  137781.       ExprList *pList = p->x.pList;

  137782.       assert( nReg<=pList->nExpr );

  137783.       for(i=0; i<nReg; i++){

  137784.         sqlite3ExprCode(pParse, pList->a[i].pExpr, iReg+i);

  137785.       }

  137786.     }

  137787.   }else{

  137788.     assert( nReg==1 );

  137789.     sqlite3ExprCode(pParse, p, iReg);

  137790.   }

  137791. }

  137792. 

  137793. /* An instance of the IdxExprTrans object carries information about a

  137794. ** mapping from an expression on table columns into a column in an index

  137795. ** down through the Walker.

  137796. */

  137797. typedef struct IdxExprTrans {

  137798.   Expr *pIdxExpr;    /* The index expression */

  137799.   int iTabCur;       /* The cursor of the corresponding table */

  137800.   int iIdxCur;       /* The cursor for the index */

  137801.   int iIdxCol;       /* The column for the index */

  137802. } IdxExprTrans;

  137803. 

  137804. /* The walker node callback used to transform matching expressions into

  137805. ** a reference to an index column for an index on an expression.

  137806. **

  137807. ** If pExpr matches, then transform it into a reference to the index column

  137808. ** that contains the value of pExpr.

  137809. */

  137810. static int whereIndexExprTransNode(Walker *p, Expr *pExpr){

  137811.   IdxExprTrans *pX = p->u.pIdxTrans;

  137812.   if( sqlite3ExprCompare(0, pExpr, pX->pIdxExpr, pX->iTabCur)==0 ){

  137813.     pExpr->op = TK_COLUMN;

  137814.     pExpr->iTable = pX->iIdxCur;

  137815.     pExpr->iColumn = pX->iIdxCol;

  137816.     pExpr->y.pTab = 0;

  137817.     return WRC_Prune;

  137818.   }else{

  137819.     return WRC_Continue;

  137820.   }

  137821. }

  137822. 

  137823. /*

  137824. ** For an indexes on expression X, locate every instance of expression X

  137825. ** in pExpr and change that subexpression into a reference to the appropriate

  137826. ** column of the index.

  137827. */

  137828. static void whereIndexExprTrans(

  137829.   Index *pIdx,      /* The Index */

  137830.   int iTabCur,      /* Cursor of the table that is being indexed */

  137831.   int iIdxCur,      /* Cursor of the index itself */

  137832.   WhereInfo *pWInfo /* Transform expressions in this WHERE clause */

  137833. ){

  137834.   int iIdxCol;               /* Column number of the index */

  137835.   ExprList *aColExpr;        /* Expressions that are indexed */

  137836.   Walker w;

  137837.   IdxExprTrans x;

  137838.   aColExpr = pIdx->aColExpr;

  137839.   if( aColExpr==0 ) return;  /* Not an index on expressions */

  137840.   memset(&w, 0, sizeof(w));

  137841.   w.xExprCallback = whereIndexExprTransNode;

  137842.   w.u.pIdxTrans = &x;

  137843.   x.iTabCur = iTabCur;

  137844.   x.iIdxCur = iIdxCur;

  137845.   for(iIdxCol=0; iIdxCol<aColExpr->nExpr; iIdxCol++){

  137846.     if( pIdx->aiColumn[iIdxCol]!=XN_EXPR ) continue;

  137847.     assert( aColExpr->a[iIdxCol].pExpr!=0 );

  137848.     x.iIdxCol = iIdxCol;

  137849.     x.pIdxExpr = aColExpr->a[iIdxCol].pExpr;

  137850.     sqlite3WalkExpr(&w, pWInfo->pWhere);

  137851.     sqlite3WalkExprList(&w, pWInfo->pOrderBy);

  137852.     sqlite3WalkExprList(&w, pWInfo->pResultSet);

  137853.   }

  137854. }

  137855. 

  137856. /*

  137857. ** The pTruth expression is always true because it is the WHERE clause

  137858. ** a partial index that is driving a query loop.  Look through all of the

  137859. ** WHERE clause terms on the query, and if any of those terms must be

  137860. ** true because pTruth is true, then mark those WHERE clause terms as

  137861. ** coded.

  137862. */

  137863. static void whereApplyPartialIndexConstraints(

  137864.   Expr *pTruth,

  137865.   int iTabCur,

  137866.   WhereClause *pWC

  137867. ){

  137868.   int i;

  137869.   WhereTerm *pTerm;

  137870.   while( pTruth->op==TK_AND ){

  137871.     whereApplyPartialIndexConstraints(pTruth->pLeft, iTabCur, pWC);

  137872.     pTruth = pTruth->pRight;

  137873.   }

  137874.   for(i=0, pTerm=pWC->a; i<pWC->nTerm; i++, pTerm++){

  137875.     Expr *pExpr;

  137876.     if( pTerm->wtFlags & TERM_CODED ) continue;

  137877.     pExpr = pTerm->pExpr;

  137878.     if( sqlite3ExprCompare(0, pExpr, pTruth, iTabCur)==0 ){

  137879.       pTerm->wtFlags |= TERM_CODED;

  137880.     }

  137881.   }

  137882. }

  137883. 

  137884. /*

  137885. ** Generate code for the start of the iLevel-th loop in the WHERE clause

  137886. ** implementation described by pWInfo.

  137887. */

  137888. SQLITE_PRIVATE Bitmask sqlite3WhereCodeOneLoopStart(

  137889.   Parse *pParse,       /* Parsing context */

  137890.   Vdbe *v,             /* Prepared statement under construction */

  137891.   WhereInfo *pWInfo,   /* Complete information about the WHERE clause */

  137892.   int iLevel,          /* Which level of pWInfo->a[] should be coded */

  137893.   WhereLevel *pLevel,  /* The current level pointer */

  137894.   Bitmask notReady     /* Which tables are currently available */

  137895. ){

  137896.   int j, k;            /* Loop counters */

  137897.   int iCur;            /* The VDBE cursor for the table */

  137898.   int addrNxt;         /* Where to jump to continue with the next IN case */

  137899.   int bRev;            /* True if we need to scan in reverse order */

  137900.   WhereLoop *pLoop;    /* The WhereLoop object being coded */

  137901.   WhereClause *pWC;    /* Decomposition of the entire WHERE clause */

  137902.   WhereTerm *pTerm;               /* A WHERE clause term */

  137903.   sqlite3 *db;                    /* Database connection */

  137904.   struct SrcList_item *pTabItem;  /* FROM clause term being coded */

  137905.   int addrBrk;                    /* Jump here to break out of the loop */

  137906.   int addrHalt;                   /* addrBrk for the outermost loop */

  137907.   int addrCont;                   /* Jump here to continue with next cycle */

  137908.   int iRowidReg = 0;        /* Rowid is stored in this register, if not zero */

  137909.   int iReleaseReg = 0;      /* Temp register to free before returning */

  137910.   Index *pIdx = 0;          /* Index used by loop (if any) */

  137911.   int iLoop;                /* Iteration of constraint generator loop */

  137912. 

  137913.   pWC = &pWInfo->sWC;

  137914.   db = pParse->db;

  137915.   pLoop = pLevel->pWLoop;

  137916.   pTabItem = &pWInfo->pTabList->a[pLevel->iFrom];

  137917.   iCur = pTabItem->iCursor;

  137918.   pLevel->notReady = notReady & ~sqlite3WhereGetMask(&pWInfo->sMaskSet, iCur);

  137919.   bRev = (pWInfo->revMask>>iLevel)&1;

  137920.   VdbeModuleComment((v, "Begin WHERE-loop%d: %s",iLevel,pTabItem->pTab->zName));

  137921. 

  137922.   /* Create labels for the "break" and "continue" instructions

  137923.   ** for the current loop.  Jump to addrBrk to break out of a loop.

  137924.   ** Jump to cont to go immediately to the next iteration of the

  137925.   ** loop.

  137926.   **

  137927.   ** When there is an IN operator, we also have a "addrNxt" label that

  137928.   ** means to continue with the next IN value combination.  When

  137929.   ** there are no IN operators in the constraints, the "addrNxt" label

  137930.   ** is the same as "addrBrk".

  137931.   */

  137932.   addrBrk = pLevel->addrBrk = pLevel->addrNxt = sqlite3VdbeMakeLabel(pParse);

  137933.   addrCont = pLevel->addrCont = sqlite3VdbeMakeLabel(pParse);

  137934. 

  137935.   /* If this is the right table of a LEFT OUTER JOIN, allocate and

  137936.   ** initialize a memory cell that records if this table matches any

  137937.   ** row of the left table of the join.

  137938.   */

  137939.   assert( (pWInfo->wctrlFlags & WHERE_OR_SUBCLAUSE)

  137940.        || pLevel->iFrom>0 || (pTabItem[0].fg.jointype & JT_LEFT)==0

  137941.   );

  137942.   if( pLevel->iFrom>0 && (pTabItem[0].fg.jointype & JT_LEFT)!=0 ){

  137943.     pLevel->iLeftJoin = ++pParse->nMem;

  137944.     sqlite3VdbeAddOp2(v, OP_Integer, 0, pLevel->iLeftJoin);

  137945.     VdbeComment((v, "init LEFT JOIN no-match flag"));

  137946.   }

  137947. 

  137948.   /* Compute a safe address to jump to if we discover that the table for

  137949.   ** this loop is empty and can never contribute content. */

  137950.   for(j=iLevel; j>0 && pWInfo->a[j].iLeftJoin==0; j--){}

  137951.   addrHalt = pWInfo->a[j].addrBrk;

  137952. 

  137953.   /* Special case of a FROM clause subquery implemented as a co-routine */

  137954.   if( pTabItem->fg.viaCoroutine ){

  137955.     int regYield = pTabItem->regReturn;

  137956.     sqlite3VdbeAddOp3(v, OP_InitCoroutine, regYield, 0, pTabItem->addrFillSub);

  137957.     pLevel->p2 =  sqlite3VdbeAddOp2(v, OP_Yield, regYield, addrBrk);

  137958.     VdbeCoverage(v);

  137959.     VdbeComment((v, "next row of %s", pTabItem->pTab->zName));

  137960.     pLevel->op = OP_Goto;

  137961.   }else

  137962. 

  137963. #ifndef SQLITE_OMIT_VIRTUALTABLE

  137964.   if(  (pLoop->wsFlags & WHERE_VIRTUALTABLE)!=0 ){

  137965.     /* Case 1:  The table is a virtual-table.  Use the VFilter and VNext

  137966.     **          to access the data.

  137967.     */

  137968.     int iReg;   /* P3 Value for OP_VFilter */

  137969.     int addrNotFound;

  137970.     int nConstraint = pLoop->nLTerm;

  137971.     int iIn;    /* Counter for IN constraints */

  137972. 

  137973.     iReg = sqlite3GetTempRange(pParse, nConstraint+2);

  137974.     addrNotFound = pLevel->addrBrk;

  137975.     for(j=0; j<nConstraint; j++){

  137976.       int iTarget = iReg+j+2;

  137977.       pTerm = pLoop->aLTerm[j];

  137978.       if( NEVER(pTerm==0) ) continue;

  137979.       if( pTerm->eOperator & WO_IN ){

  137980.         codeEqualityTerm(pParse, pTerm, pLevel, j, bRev, iTarget);

  137981.         addrNotFound = pLevel->addrNxt;

  137982.       }else{

  137983.         Expr *pRight = pTerm->pExpr->pRight;

  137984.         codeExprOrVector(pParse, pRight, iTarget, 1);

  137985.       }

  137986.     }

  137987.     sqlite3VdbeAddOp2(v, OP_Integer, pLoop->u.vtab.idxNum, iReg);

  137988.     sqlite3VdbeAddOp2(v, OP_Integer, nConstraint, iReg+1);

  137989.     sqlite3VdbeAddOp4(v, OP_VFilter, iCur, addrNotFound, iReg,

  137990.                       pLoop->u.vtab.idxStr,

  137991.                       pLoop->u.vtab.needFree ? P4_DYNAMIC : P4_STATIC);

  137992.     VdbeCoverage(v);

  137993.     pLoop->u.vtab.needFree = 0;

  137994.     pLevel->p1 = iCur;

  137995.     pLevel->op = pWInfo->eOnePass ? OP_Noop : OP_VNext;

  137996.     pLevel->p2 = sqlite3VdbeCurrentAddr(v);

  137997.     iIn = pLevel->u.in.nIn;

  137998.     for(j=nConstraint-1; j>=0; j--){

  137999.       pTerm = pLoop->aLTerm[j];

  138000.       if( j<16 && (pLoop->u.vtab.omitMask>>j)&1 ){

  138001.         disableTerm(pLevel, pTerm);

  138002.       }else if( (pTerm->eOperator & WO_IN)!=0 ){

  138003.         Expr *pCompare;  /* The comparison operator */

  138004.         Expr *pRight;    /* RHS of the comparison */

  138005.         VdbeOp *pOp;     /* Opcode to access the value of the IN constraint */

  138006. 

  138007.         /* Reload the constraint value into reg[iReg+j+2].  The same value

  138008.         ** was loaded into the same register prior to the OP_VFilter, but

  138009.         ** the xFilter implementation might have changed the datatype or

  138010.         ** encoding of the value in the register, so it *must* be reloaded. */

  138011.         assert( pLevel->u.in.aInLoop!=0 || db->mallocFailed );

  138012.         if( !db->mallocFailed ){

  138013.           assert( iIn>0 );

  138014.           pOp = sqlite3VdbeGetOp(v, pLevel->u.in.aInLoop[--iIn].addrInTop);

  138015.           assert( pOp->opcode==OP_Column || pOp->opcode==OP_Rowid );

  138016.           assert( pOp->opcode!=OP_Column || pOp->p3==iReg+j+2 );

  138017.           assert( pOp->opcode!=OP_Rowid || pOp->p2==iReg+j+2 );

  138018.           testcase( pOp->opcode==OP_Rowid );

  138019.           sqlite3VdbeAddOp3(v, pOp->opcode, pOp->p1, pOp->p2, pOp->p3);

  138020.         }

  138021. 

  138022.         /* Generate code that will continue to the next row if 

  138023.         ** the IN constraint is not satisfied */

  138024.         pCompare = sqlite3PExpr(pParse, TK_EQ, 0, 0);

  138025.         assert( pCompare!=0 || db->mallocFailed );

  138026.         if( pCompare ){

  138027.           pCompare->pLeft = pTerm->pExpr->pLeft;

  138028.           pCompare->pRight = pRight = sqlite3Expr(db, TK_REGISTER, 0);

  138029.           if( pRight ){

  138030.             pRight->iTable = iReg+j+2;

  138031.             sqlite3ExprIfFalse(pParse, pCompare, pLevel->addrCont, 0);

  138032.           }

  138033.           pCompare->pLeft = 0;

  138034.           sqlite3ExprDelete(db, pCompare);

  138035.         }

  138036.       }

  138037.     }

  138038.     /* These registers need to be preserved in case there is an IN operator

  138039.     ** loop.  So we could deallocate the registers here (and potentially

  138040.     ** reuse them later) if (pLoop->wsFlags & WHERE_IN_ABLE)==0.  But it seems

  138041.     ** simpler and safer to simply not reuse the registers.

  138042.     **

  138043.     **    sqlite3ReleaseTempRange(pParse, iReg, nConstraint+2);

  138044.     */

  138045.   }else

  138046. #endif /* SQLITE_OMIT_VIRTUALTABLE */

  138047. 

  138048.   if( (pLoop->wsFlags & WHERE_IPK)!=0

  138049.    && (pLoop->wsFlags & (WHERE_COLUMN_IN|WHERE_COLUMN_EQ))!=0

  138050.   ){

  138051.     /* Case 2:  We can directly reference a single row using an

  138052.     **          equality comparison against the ROWID field.  Or

  138053.     **          we reference multiple rows using a "rowid IN (...)"

  138054.     **          construct.

  138055.     */

  138056.     assert( pLoop->u.btree.nEq==1 );

  138057.     pTerm = pLoop->aLTerm[0];

  138058.     assert( pTerm!=0 );

  138059.     assert( pTerm->pExpr!=0 );

  138060.     testcase( pTerm->wtFlags & TERM_VIRTUAL );

  138061.     iReleaseReg = ++pParse->nMem;

  138062.     iRowidReg = codeEqualityTerm(pParse, pTerm, pLevel, 0, bRev, iReleaseReg);

  138063.     if( iRowidReg!=iReleaseReg ) sqlite3ReleaseTempReg(pParse, iReleaseReg);

  138064.     addrNxt = pLevel->addrNxt;

  138065.     sqlite3VdbeAddOp3(v, OP_SeekRowid, iCur, addrNxt, iRowidReg);

  138066.     VdbeCoverage(v);

  138067.     pLevel->op = OP_Noop;

  138068.     if( (pTerm->prereqAll & pLevel->notReady)==0 ){

  138069.       pTerm->wtFlags |= TERM_CODED;

  138070.     }

  138071.   }else if( (pLoop->wsFlags & WHERE_IPK)!=0

  138072.          && (pLoop->wsFlags & WHERE_COLUMN_RANGE)!=0

  138073.   ){

  138074.     /* Case 3:  We have an inequality comparison against the ROWID field.

  138075.     */

  138076.     int testOp = OP_Noop;

  138077.     int start;

  138078.     int memEndValue = 0;

  138079.     WhereTerm *pStart, *pEnd;

  138080. 

  138081.     j = 0;

  138082.     pStart = pEnd = 0;

  138083.     if( pLoop->wsFlags & WHERE_BTM_LIMIT ) pStart = pLoop->aLTerm[j++];

  138084.     if( pLoop->wsFlags & WHERE_TOP_LIMIT ) pEnd = pLoop->aLTerm[j++];

  138085.     assert( pStart!=0 || pEnd!=0 );

  138086.     if( bRev ){

  138087.       pTerm = pStart;

  138088.       pStart = pEnd;

  138089.       pEnd = pTerm;

  138090.     }

  138091.     codeCursorHint(pTabItem, pWInfo, pLevel, pEnd);

  138092.     if( pStart ){

  138093.       Expr *pX;             /* The expression that defines the start bound */

  138094.       int r1, rTemp;        /* Registers for holding the start boundary */

  138095.       int op;               /* Cursor seek operation */

  138096. 

  138097.       /* The following constant maps TK_xx codes into corresponding 

  138098.       ** seek opcodes.  It depends on a particular ordering of TK_xx

  138099.       */

  138100.       const u8 aMoveOp[] = {

  138101.            /* TK_GT */  OP_SeekGT,

  138102.            /* TK_LE */  OP_SeekLE,

  138103.            /* TK_LT */  OP_SeekLT,

  138104.            /* TK_GE */  OP_SeekGE

  138105.       };

  138106.       assert( TK_LE==TK_GT+1 );      /* Make sure the ordering.. */

  138107.       assert( TK_LT==TK_GT+2 );      /*  ... of the TK_xx values... */

  138108.       assert( TK_GE==TK_GT+3 );      /*  ... is correcct. */

  138109. 

  138110.       assert( (pStart->wtFlags & TERM_VNULL)==0 );

  138111.       testcase( pStart->wtFlags & TERM_VIRTUAL );

  138112.       pX = pStart->pExpr;

  138113.       assert( pX!=0 );

  138114.       testcase( pStart->leftCursor!=iCur ); /* transitive constraints */

  138115.       if( sqlite3ExprIsVector(pX->pRight) ){

  138116.         r1 = rTemp = sqlite3GetTempReg(pParse);

  138117.         codeExprOrVector(pParse, pX->pRight, r1, 1);

  138118.         testcase( pX->op==TK_GT );

  138119.         testcase( pX->op==TK_GE );

  138120.         testcase( pX->op==TK_LT );

  138121.         testcase( pX->op==TK_LE );

  138122.         op = aMoveOp[((pX->op - TK_GT - 1) & 0x3) | 0x1];

  138123.         assert( pX->op!=TK_GT || op==OP_SeekGE );

  138124.         assert( pX->op!=TK_GE || op==OP_SeekGE );

  138125.         assert( pX->op!=TK_LT || op==OP_SeekLE );

  138126.         assert( pX->op!=TK_LE || op==OP_SeekLE );

  138127.       }else{

  138128.         r1 = sqlite3ExprCodeTemp(pParse, pX->pRight, &rTemp);

  138129.         disableTerm(pLevel, pStart);

  138130.         op = aMoveOp[(pX->op - TK_GT)];

  138131.       }

  138132.       sqlite3VdbeAddOp3(v, op, iCur, addrBrk, r1);

  138133.       VdbeComment((v, "pk"));

  138134.       VdbeCoverageIf(v, pX->op==TK_GT);

  138135.       VdbeCoverageIf(v, pX->op==TK_LE);

  138136.       VdbeCoverageIf(v, pX->op==TK_LT);

  138137.       VdbeCoverageIf(v, pX->op==TK_GE);

  138138.       sqlite3ReleaseTempReg(pParse, rTemp);

  138139.     }else{

  138140.       sqlite3VdbeAddOp2(v, bRev ? OP_Last : OP_Rewind, iCur, addrHalt);

  138141.       VdbeCoverageIf(v, bRev==0);

  138142.       VdbeCoverageIf(v, bRev!=0);

  138143.     }

  138144.     if( pEnd ){

  138145.       Expr *pX;

  138146.       pX = pEnd->pExpr;

  138147.       assert( pX!=0 );

  138148.       assert( (pEnd->wtFlags & TERM_VNULL)==0 );

  138149.       testcase( pEnd->leftCursor!=iCur ); /* Transitive constraints */

  138150.       testcase( pEnd->wtFlags & TERM_VIRTUAL );

  138151.       memEndValue = ++pParse->nMem;

  138152.       codeExprOrVector(pParse, pX->pRight, memEndValue, 1);

  138153.       if( 0==sqlite3ExprIsVector(pX->pRight) 

  138154.        && (pX->op==TK_LT || pX->op==TK_GT) 

  138155.       ){

  138156.         testOp = bRev ? OP_Le : OP_Ge;

  138157.       }else{

  138158.         testOp = bRev ? OP_Lt : OP_Gt;

  138159.       }

  138160.       if( 0==sqlite3ExprIsVector(pX->pRight) ){

  138161.         disableTerm(pLevel, pEnd);

  138162.       }

  138163.     }

  138164.     start = sqlite3VdbeCurrentAddr(v);

  138165.     pLevel->op = bRev ? OP_Prev : OP_Next;

  138166.     pLevel->p1 = iCur;

  138167.     pLevel->p2 = start;

  138168.     assert( pLevel->p5==0 );

  138169.     if( testOp!=OP_Noop ){

  138170.       iRowidReg = ++pParse->nMem;

  138171.       sqlite3VdbeAddOp2(v, OP_Rowid, iCur, iRowidReg);

  138172.       sqlite3VdbeAddOp3(v, testOp, memEndValue, addrBrk, iRowidReg);

  138173.       VdbeCoverageIf(v, testOp==OP_Le);

  138174.       VdbeCoverageIf(v, testOp==OP_Lt);

  138175.       VdbeCoverageIf(v, testOp==OP_Ge);

  138176.       VdbeCoverageIf(v, testOp==OP_Gt);

  138177.       sqlite3VdbeChangeP5(v, SQLITE_AFF_NUMERIC | SQLITE_JUMPIFNULL);

  138178.     }

  138179.   }else if( pLoop->wsFlags & WHERE_INDEXED ){

  138180.     /* Case 4: A scan using an index.

  138181.     **

  138182.     **         The WHERE clause may contain zero or more equality 

  138183.     **         terms ("==" or "IN" operators) that refer to the N

  138184.     **         left-most columns of the index. It may also contain

  138185.     **         inequality constraints (>, <, >= or <=) on the indexed

  138186.     **         column that immediately follows the N equalities. Only 

  138187.     **         the right-most column can be an inequality - the rest must

  138188.     **         use the "==" and "IN" operators. For example, if the 

  138189.     **         index is on (x,y,z), then the following clauses are all 

  138190.     **         optimized:

  138191.     **

  138192.     **            x=5

  138193.     **            x=5 AND y=10

  138194.     **            x=5 AND y<10

  138195.     **            x=5 AND y>5 AND y<10

  138196.     **            x=5 AND y=5 AND z<=10

  138197.     **

  138198.     **         The z<10 term of the following cannot be used, only

  138199.     **         the x=5 term:

  138200.     **

  138201.     **            x=5 AND z<10

  138202.     **

  138203.     **         N may be zero if there are inequality constraints.

  138204.     **         If there are no inequality constraints, then N is at

  138205.     **         least one.

  138206.     **

  138207.     **         This case is also used when there are no WHERE clause

  138208.     **         constraints but an index is selected anyway, in order

  138209.     **         to force the output order to conform to an ORDER BY.

  138210.     */  

  138211.     static const u8 aStartOp[] = {

  138212.       0,

  138213.       0,

  138214.       OP_Rewind,           /* 2: (!start_constraints && startEq &&  !bRev) */

  138215.       OP_Last,             /* 3: (!start_constraints && startEq &&   bRev) */

  138216.       OP_SeekGT,           /* 4: (start_constraints  && !startEq && !bRev) */

  138217.       OP_SeekLT,           /* 5: (start_constraints  && !startEq &&  bRev) */

  138218.       OP_SeekGE,           /* 6: (start_constraints  &&  startEq && !bRev) */

  138219.       OP_SeekLE            /* 7: (start_constraints  &&  startEq &&  bRev) */

  138220.     };

  138221.     static const u8 aEndOp[] = {

  138222.       OP_IdxGE,            /* 0: (end_constraints && !bRev && !endEq) */

  138223.       OP_IdxGT,            /* 1: (end_constraints && !bRev &&  endEq) */

  138224.       OP_IdxLE,            /* 2: (end_constraints &&  bRev && !endEq) */

  138225.       OP_IdxLT,            /* 3: (end_constraints &&  bRev &&  endEq) */

  138226.     };

  138227.     u16 nEq = pLoop->u.btree.nEq;     /* Number of == or IN terms */

  138228.     u16 nBtm = pLoop->u.btree.nBtm;   /* Length of BTM vector */

  138229.     u16 nTop = pLoop->u.btree.nTop;   /* Length of TOP vector */

  138230.     int regBase;                 /* Base register holding constraint values */

  138231.     WhereTerm *pRangeStart = 0;  /* Inequality constraint at range start */

  138232.     WhereTerm *pRangeEnd = 0;    /* Inequality constraint at range end */

  138233.     int startEq;                 /* True if range start uses ==, >= or <= */

  138234.     int endEq;                   /* True if range end uses ==, >= or <= */

  138235.     int start_constraints;       /* Start of range is constrained */

  138236.     int nConstraint;             /* Number of constraint terms */

  138237.     int iIdxCur;                 /* The VDBE cursor for the index */

  138238.     int nExtraReg = 0;           /* Number of extra registers needed */

  138239.     int op;                      /* Instruction opcode */

  138240.     char *zStartAff;             /* Affinity for start of range constraint */

  138241.     char *zEndAff = 0;           /* Affinity for end of range constraint */

  138242.     u8 bSeekPastNull = 0;        /* True to seek past initial nulls */

  138243.     u8 bStopAtNull = 0;          /* Add condition to terminate at NULLs */

  138244.     int omitTable;               /* True if we use the index only */

  138245. 

  138246. 

  138247.     pIdx = pLoop->u.btree.pIndex;

  138248.     iIdxCur = pLevel->iIdxCur;

  138249.     assert( nEq>=pLoop->nSkip );

  138250. 

  138251.     /* If this loop satisfies a sort order (pOrderBy) request that 

  138252.     ** was passed to this function to implement a "SELECT min(x) ..." 

  138253.     ** query, then the caller will only allow the loop to run for

  138254.     ** a single iteration. This means that the first row returned

  138255.     ** should not have a NULL value stored in 'x'. If column 'x' is

  138256.     ** the first one after the nEq equality constraints in the index,

  138257.     ** this requires some special handling.

  138258.     */

  138259.     assert( pWInfo->pOrderBy==0

  138260.          || pWInfo->pOrderBy->nExpr==1

  138261.          || (pWInfo->wctrlFlags&WHERE_ORDERBY_MIN)==0 );

  138262.     if( (pWInfo->wctrlFlags&WHERE_ORDERBY_MIN)!=0

  138263.      && pWInfo->nOBSat>0

  138264.      && (pIdx->nKeyCol>nEq)

  138265.     ){

  138266.       assert( pLoop->nSkip==0 );

  138267.       bSeekPastNull = 1;

  138268.       nExtraReg = 1;

  138269.     }

  138270. 

  138271.     /* Find any inequality constraint terms for the start and end 

  138272.     ** of the range. 

  138273.     */

  138274.     j = nEq;

  138275.     if( pLoop->wsFlags & WHERE_BTM_LIMIT ){

  138276.       pRangeStart = pLoop->aLTerm[j++];

  138277.       nExtraReg = MAX(nExtraReg, pLoop->u.btree.nBtm);

  138278.       /* Like optimization range constraints always occur in pairs */

  138279.       assert( (pRangeStart->wtFlags & TERM_LIKEOPT)==0 || 

  138280.               (pLoop->wsFlags & WHERE_TOP_LIMIT)!=0 );

  138281.     }

  138282.     if( pLoop->wsFlags & WHERE_TOP_LIMIT ){

  138283.       pRangeEnd = pLoop->aLTerm[j++];

  138284.       nExtraReg = MAX(nExtraReg, pLoop->u.btree.nTop);

  138285. #ifndef SQLITE_LIKE_DOESNT_MATCH_BLOBS

  138286.       if( (pRangeEnd->wtFlags & TERM_LIKEOPT)!=0 ){

  138287.         assert( pRangeStart!=0 );                     /* LIKE opt constraints */

  138288.         assert( pRangeStart->wtFlags & TERM_LIKEOPT );   /* occur in pairs */

  138289.         pLevel->iLikeRepCntr = (u32)++pParse->nMem;

  138290.         sqlite3VdbeAddOp2(v, OP_Integer, 1, (int)pLevel->iLikeRepCntr);

  138291.         VdbeComment((v, "LIKE loop counter"));

  138292.         pLevel->addrLikeRep = sqlite3VdbeCurrentAddr(v);

  138293.         /* iLikeRepCntr actually stores 2x the counter register number.  The

  138294.         ** bottom bit indicates whether the search order is ASC or DESC. */

  138295.         testcase( bRev );

  138296.         testcase( pIdx->aSortOrder[nEq]==SQLITE_SO_DESC );

  138297.         assert( (bRev & ~1)==0 );

  138298.         pLevel->iLikeRepCntr <<=1;

  138299.         pLevel->iLikeRepCntr |= bRev ^ (pIdx->aSortOrder[nEq]==SQLITE_SO_DESC);

  138300.       }

  138301. #endif

  138302.       if( pRangeStart==0 ){

  138303.         j = pIdx->aiColumn[nEq];

  138304.         if( (j>=0 && pIdx->pTable->aCol[j].notNull==0) || j==XN_EXPR ){

  138305.           bSeekPastNull = 1;

  138306.         }

  138307.       }

  138308.     }

  138309.     assert( pRangeEnd==0 || (pRangeEnd->wtFlags & TERM_VNULL)==0 );

  138310. 

  138311.     /* If we are doing a reverse order scan on an ascending index, or

  138312.     ** a forward order scan on a descending index, interchange the 

  138313.     ** start and end terms (pRangeStart and pRangeEnd).

  138314.     */

  138315.     if( (nEq<pIdx->nKeyCol && bRev==(pIdx->aSortOrder[nEq]==SQLITE_SO_ASC))

  138316.      || (bRev && pIdx->nKeyCol==nEq)

  138317.     ){

  138318.       SWAP(WhereTerm *, pRangeEnd, pRangeStart);

  138319.       SWAP(u8, bSeekPastNull, bStopAtNull);

  138320.       SWAP(u8, nBtm, nTop);

  138321.     }

  138322. 

  138323.     /* Generate code to evaluate all constraint terms using == or IN

  138324.     ** and store the values of those terms in an array of registers

  138325.     ** starting at regBase.

  138326.     */

  138327.     codeCursorHint(pTabItem, pWInfo, pLevel, pRangeEnd);

  138328.     regBase = codeAllEqualityTerms(pParse,pLevel,bRev,nExtraReg,&zStartAff);

  138329.     assert( zStartAff==0 || sqlite3Strlen30(zStartAff)>=nEq );

  138330.     if( zStartAff && nTop ){

  138331.       zEndAff = sqlite3DbStrDup(db, &zStartAff[nEq]);

  138332.     }

  138333.     addrNxt = pLevel->addrNxt;

  138334. 

  138335.     testcase( pRangeStart && (pRangeStart->eOperator & WO_LE)!=0 );

  138336.     testcase( pRangeStart && (pRangeStart->eOperator & WO_GE)!=0 );

  138337.     testcase( pRangeEnd && (pRangeEnd->eOperator & WO_LE)!=0 );

  138338.     testcase( pRangeEnd && (pRangeEnd->eOperator & WO_GE)!=0 );

  138339.     startEq = !pRangeStart || pRangeStart->eOperator & (WO_LE|WO_GE);

  138340.     endEq =   !pRangeEnd || pRangeEnd->eOperator & (WO_LE|WO_GE);

  138341.     start_constraints = pRangeStart || nEq>0;

  138342. 

  138343.     /* Seek the index cursor to the start of the range. */

  138344.     nConstraint = nEq;

  138345.     if( pRangeStart ){

  138346.       Expr *pRight = pRangeStart->pExpr->pRight;

  138347.       codeExprOrVector(pParse, pRight, regBase+nEq, nBtm);

  138348.       whereLikeOptimizationStringFixup(v, pLevel, pRangeStart);

  138349.       if( (pRangeStart->wtFlags & TERM_VNULL)==0

  138350.        && sqlite3ExprCanBeNull(pRight)

  138351.       ){

  138352.         sqlite3VdbeAddOp2(v, OP_IsNull, regBase+nEq, addrNxt);

  138353.         VdbeCoverage(v);

  138354.       }

  138355.       if( zStartAff ){

  138356.         updateRangeAffinityStr(pRight, nBtm, &zStartAff[nEq]);

  138357.       }  

  138358.       nConstraint += nBtm;

  138359.       testcase( pRangeStart->wtFlags & TERM_VIRTUAL );

  138360.       if( sqlite3ExprIsVector(pRight)==0 ){

  138361.         disableTerm(pLevel, pRangeStart);

  138362.       }else{

  138363.         startEq = 1;

  138364.       }

  138365.       bSeekPastNull = 0;

  138366.     }else if( bSeekPastNull ){

  138367.       sqlite3VdbeAddOp2(v, OP_Null, 0, regBase+nEq);

  138368.       nConstraint++;

  138369.       startEq = 0;

  138370.       start_constraints = 1;

  138371.     }

  138372.     codeApplyAffinity(pParse, regBase, nConstraint - bSeekPastNull, zStartAff);

  138373.     if( pLoop->nSkip>0 && nConstraint==pLoop->nSkip ){

  138374.       /* The skip-scan logic inside the call to codeAllEqualityConstraints()

  138375.       ** above has already left the cursor sitting on the correct row,

  138376.       ** so no further seeking is needed */

  138377.     }else{

  138378.       if( pLoop->wsFlags & WHERE_IN_EARLYOUT ){

  138379.         sqlite3VdbeAddOp1(v, OP_SeekHit, iIdxCur);

  138380.       }

  138381.       op = aStartOp[(start_constraints<<2) + (startEq<<1) + bRev];

  138382.       assert( op!=0 );

  138383.       sqlite3VdbeAddOp4Int(v, op, iIdxCur, addrNxt, regBase, nConstraint);

  138384.       VdbeCoverage(v);

  138385.       VdbeCoverageIf(v, op==OP_Rewind);  testcase( op==OP_Rewind );

  138386.       VdbeCoverageIf(v, op==OP_Last);    testcase( op==OP_Last );

  138387.       VdbeCoverageIf(v, op==OP_SeekGT);  testcase( op==OP_SeekGT );

  138388.       VdbeCoverageIf(v, op==OP_SeekGE);  testcase( op==OP_SeekGE );

  138389.       VdbeCoverageIf(v, op==OP_SeekLE);  testcase( op==OP_SeekLE );

  138390.       VdbeCoverageIf(v, op==OP_SeekLT);  testcase( op==OP_SeekLT );

  138391.     }

  138392. 

  138393.     /* Load the value for the inequality constraint at the end of the

  138394.     ** range (if any).

  138395.     */

  138396.     nConstraint = nEq;

  138397.     if( pRangeEnd ){

  138398.       Expr *pRight = pRangeEnd->pExpr->pRight;

  138399.       codeExprOrVector(pParse, pRight, regBase+nEq, nTop);

  138400.       whereLikeOptimizationStringFixup(v, pLevel, pRangeEnd);

  138401.       if( (pRangeEnd->wtFlags & TERM_VNULL)==0

  138402.        && sqlite3ExprCanBeNull(pRight)

  138403.       ){

  138404.         sqlite3VdbeAddOp2(v, OP_IsNull, regBase+nEq, addrNxt);

  138405.         VdbeCoverage(v);

  138406.       }

  138407.       if( zEndAff ){

  138408.         updateRangeAffinityStr(pRight, nTop, zEndAff);

  138409.         codeApplyAffinity(pParse, regBase+nEq, nTop, zEndAff);

  138410.       }else{

  138411.         assert( pParse->db->mallocFailed );

  138412.       }

  138413.       nConstraint += nTop;

  138414.       testcase( pRangeEnd->wtFlags & TERM_VIRTUAL );

  138415. 

  138416.       if( sqlite3ExprIsVector(pRight)==0 ){

  138417.         disableTerm(pLevel, pRangeEnd);

  138418.       }else{

  138419.         endEq = 1;

  138420.       }

  138421.     }else if( bStopAtNull ){

  138422.       sqlite3VdbeAddOp2(v, OP_Null, 0, regBase+nEq);

  138423.       endEq = 0;

  138424.       nConstraint++;

  138425.     }

  138426.     sqlite3DbFree(db, zStartAff);

  138427.     sqlite3DbFree(db, zEndAff);

  138428. 

  138429.     /* Top of the loop body */

  138430.     pLevel->p2 = sqlite3VdbeCurrentAddr(v);

  138431. 

  138432.     /* Check if the index cursor is past the end of the range. */

  138433.     if( nConstraint ){

  138434.       op = aEndOp[bRev*2 + endEq];

  138435.       sqlite3VdbeAddOp4Int(v, op, iIdxCur, addrNxt, regBase, nConstraint);

  138436.       testcase( op==OP_IdxGT );  VdbeCoverageIf(v, op==OP_IdxGT );

  138437.       testcase( op==OP_IdxGE );  VdbeCoverageIf(v, op==OP_IdxGE );

  138438.       testcase( op==OP_IdxLT );  VdbeCoverageIf(v, op==OP_IdxLT );

  138439.       testcase( op==OP_IdxLE );  VdbeCoverageIf(v, op==OP_IdxLE );

  138440.     }

  138441. 

  138442.     if( pLoop->wsFlags & WHERE_IN_EARLYOUT ){

  138443.       sqlite3VdbeAddOp2(v, OP_SeekHit, iIdxCur, 1);

  138444.     }

  138445. 

  138446.     /* Seek the table cursor, if required */

  138447.     omitTable = (pLoop->wsFlags & WHERE_IDX_ONLY)!=0 

  138448.            && (pWInfo->wctrlFlags & WHERE_OR_SUBCLAUSE)==0;

  138449.     if( omitTable ){

  138450.       /* pIdx is a covering index.  No need to access the main table. */

  138451.     }else if( HasRowid(pIdx->pTable) ){

  138452.       if( (pWInfo->wctrlFlags & WHERE_SEEK_TABLE) || (

  138453.           (pWInfo->wctrlFlags & WHERE_SEEK_UNIQ_TABLE) 

  138454.        && (pWInfo->eOnePass==ONEPASS_SINGLE)

  138455.       )){

  138456.         iRowidReg = ++pParse->nMem;

  138457.         sqlite3VdbeAddOp2(v, OP_IdxRowid, iIdxCur, iRowidReg);

  138458.         sqlite3VdbeAddOp3(v, OP_NotExists, iCur, 0, iRowidReg);

  138459.         VdbeCoverage(v);

  138460.       }else{

  138461.         codeDeferredSeek(pWInfo, pIdx, iCur, iIdxCur);

  138462.       }

  138463.     }else if( iCur!=iIdxCur ){

  138464.       Index *pPk = sqlite3PrimaryKeyIndex(pIdx->pTable);

  138465.       iRowidReg = sqlite3GetTempRange(pParse, pPk->nKeyCol);

  138466.       for(j=0; j<pPk->nKeyCol; j++){

  138467.         k = sqlite3ColumnOfIndex(pIdx, pPk->aiColumn[j]);

  138468.         sqlite3VdbeAddOp3(v, OP_Column, iIdxCur, k, iRowidReg+j);

  138469.       }

  138470.       sqlite3VdbeAddOp4Int(v, OP_NotFound, iCur, addrCont,

  138471.                            iRowidReg, pPk->nKeyCol); VdbeCoverage(v);

  138472.     }

  138473. 

  138474.     /* If pIdx is an index on one or more expressions, then look through

  138475.     ** all the expressions in pWInfo and try to transform matching expressions

  138476.     ** into reference to index columns.

  138477.     **

  138478.     ** Do not do this for the RHS of a LEFT JOIN. This is because the 

  138479.     ** expression may be evaluated after OP_NullRow has been executed on

  138480.     ** the cursor. In this case it is important to do the full evaluation,

  138481.     ** as the result of the expression may not be NULL, even if all table

  138482.     ** column values are.  https://www.sqlite.org/src/info/7fa8049685b50b5a

  138483.     **

  138484.     ** Also, do not do this when processing one index an a multi-index

  138485.     ** OR clause, since the transformation will become invalid once we

  138486.     ** move forward to the next index.

  138487.     ** https://sqlite.org/src/info/4e8e4857d32d401f

  138488.     */

  138489.     if( pLevel->iLeftJoin==0 && (pWInfo->wctrlFlags & WHERE_OR_SUBCLAUSE)==0 ){

  138490.       whereIndexExprTrans(pIdx, iCur, iIdxCur, pWInfo);

  138491.     }

  138492. 

  138493.     /* If a partial index is driving the loop, try to eliminate WHERE clause

  138494.     ** terms from the query that must be true due to the WHERE clause of

  138495.     ** the partial index

  138496.     */

  138497.     if( pIdx->pPartIdxWhere ){

  138498.       whereApplyPartialIndexConstraints(pIdx->pPartIdxWhere, iCur, pWC);

  138499.     }

  138500. 

  138501.     /* Record the instruction used to terminate the loop. */

  138502.     if( pLoop->wsFlags & WHERE_ONEROW ){

  138503.       pLevel->op = OP_Noop;

  138504.     }else if( bRev ){

  138505.       pLevel->op = OP_Prev;

  138506.     }else{

  138507.       pLevel->op = OP_Next;

  138508.     }

  138509.     pLevel->p1 = iIdxCur;

  138510.     pLevel->p3 = (pLoop->wsFlags&WHERE_UNQ_WANTED)!=0 ? 1:0;

  138511.     if( (pLoop->wsFlags & WHERE_CONSTRAINT)==0 ){

  138512.       pLevel->p5 = SQLITE_STMTSTATUS_FULLSCAN_STEP;

  138513.     }else{

  138514.       assert( pLevel->p5==0 );

  138515.     }

  138516.     if( omitTable ) pIdx = 0;

  138517.   }else

  138518. 

  138519. #ifndef SQLITE_OMIT_OR_OPTIMIZATION

  138520.   if( pLoop->wsFlags & WHERE_MULTI_OR ){

  138521.     /* Case 5:  Two or more separately indexed terms connected by OR

  138522.     **

  138523.     ** Example:

  138524.     **

  138525.     **   CREATE TABLE t1(a,b,c,d);

  138526.     **   CREATE INDEX i1 ON t1(a);

  138527.     **   CREATE INDEX i2 ON t1(b);

  138528.     **   CREATE INDEX i3 ON t1(c);

  138529.     **

  138530.     **   SELECT * FROM t1 WHERE a=5 OR b=7 OR (c=11 AND d=13)

  138531.     **

  138532.     ** In the example, there are three indexed terms connected by OR.

  138533.     ** The top of the loop looks like this:

  138534.     **

  138535.     **          Null       1                # Zero the rowset in reg 1

  138536.     **

  138537.     ** Then, for each indexed term, the following. The arguments to

  138538.     ** RowSetTest are such that the rowid of the current row is inserted

  138539.     ** into the RowSet. If it is already present, control skips the

  138540.     ** Gosub opcode and jumps straight to the code generated by WhereEnd().

  138541.     **

  138542.     **        sqlite3WhereBegin(<term>)

  138543.     **          RowSetTest                  # Insert rowid into rowset

  138544.     **          Gosub      2 A

  138545.     **        sqlite3WhereEnd()

  138546.     **

  138547.     ** Following the above, code to terminate the loop. Label A, the target

  138548.     ** of the Gosub above, jumps to the instruction right after the Goto.

  138549.     **

  138550.     **          Null       1                # Zero the rowset in reg 1

  138551.     **          Goto       B                # The loop is finished.

  138552.     **

  138553.     **       A: <loop body>                 # Return data, whatever.

  138554.     **

  138555.     **          Return     2                # Jump back to the Gosub

  138556.     **

  138557.     **       B: <after the loop>

  138558.     **

  138559.     ** Added 2014-05-26: If the table is a WITHOUT ROWID table, then

  138560.     ** use an ephemeral index instead of a RowSet to record the primary

  138561.     ** keys of the rows we have already seen.

  138562.     **

  138563.     */

  138564.     WhereClause *pOrWc;    /* The OR-clause broken out into subterms */

  138565.     SrcList *pOrTab;       /* Shortened table list or OR-clause generation */

  138566.     Index *pCov = 0;             /* Potential covering index (or NULL) */

  138567.     int iCovCur = pParse->nTab++;  /* Cursor used for index scans (if any) */

  138568. 

  138569.     int regReturn = ++pParse->nMem;           /* Register used with OP_Gosub */

  138570.     int regRowset = 0;                        /* Register for RowSet object */

  138571.     int regRowid = 0;                         /* Register holding rowid */

  138572.     int iLoopBody = sqlite3VdbeMakeLabel(pParse);/* Start of loop body */

  138573.     int iRetInit;                             /* Address of regReturn init */

  138574.     int untestedTerms = 0;             /* Some terms not completely tested */

  138575.     int ii;                            /* Loop counter */

  138576.     u16 wctrlFlags;                    /* Flags for sub-WHERE clause */

  138577.     Expr *pAndExpr = 0;                /* An ".. AND (...)" expression */

  138578.     Table *pTab = pTabItem->pTab;

  138579. 

  138580.     pTerm = pLoop->aLTerm[0];

  138581.     assert( pTerm!=0 );

  138582.     assert( pTerm->eOperator & WO_OR );

  138583.     assert( (pTerm->wtFlags & TERM_ORINFO)!=0 );

  138584.     pOrWc = &pTerm->u.pOrInfo->wc;

  138585.     pLevel->op = OP_Return;

  138586.     pLevel->p1 = regReturn;

  138587. 

  138588.     /* Set up a new SrcList in pOrTab containing the table being scanned

  138589.     ** by this loop in the a[0] slot and all notReady tables in a[1..] slots.

  138590.     ** This becomes the SrcList in the recursive call to sqlite3WhereBegin().

  138591.     */

  138592.     if( pWInfo->nLevel>1 ){

  138593.       int nNotReady;                 /* The number of notReady tables */

  138594.       struct SrcList_item *origSrc;     /* Original list of tables */

  138595.       nNotReady = pWInfo->nLevel - iLevel - 1;

  138596.       pOrTab = sqlite3StackAllocRaw(db,

  138597.                             sizeof(*pOrTab)+ nNotReady*sizeof(pOrTab->a[0]));

  138598.       if( pOrTab==0 ) return notReady;

  138599.       pOrTab->nAlloc = (u8)(nNotReady + 1);

  138600.       pOrTab->nSrc = pOrTab->nAlloc;

  138601.       memcpy(pOrTab->a, pTabItem, sizeof(*pTabItem));

  138602.       origSrc = pWInfo->pTabList->a;

  138603.       for(k=1; k<=nNotReady; k++){

  138604.         memcpy(&pOrTab->a[k], &origSrc[pLevel[k].iFrom], sizeof(pOrTab->a[k]));

  138605.       }

  138606.     }else{

  138607.       pOrTab = pWInfo->pTabList;

  138608.     }

  138609. 

  138610.     /* Initialize the rowset register to contain NULL. An SQL NULL is 

  138611.     ** equivalent to an empty rowset.  Or, create an ephemeral index

  138612.     ** capable of holding primary keys in the case of a WITHOUT ROWID.

  138613.     **

  138614.     ** Also initialize regReturn to contain the address of the instruction 

  138615.     ** immediately following the OP_Return at the bottom of the loop. This

  138616.     ** is required in a few obscure LEFT JOIN cases where control jumps

  138617.     ** over the top of the loop into the body of it. In this case the 

  138618.     ** correct response for the end-of-loop code (the OP_Return) is to 

  138619.     ** fall through to the next instruction, just as an OP_Next does if

  138620.     ** called on an uninitialized cursor.

  138621.     */

  138622.     if( (pWInfo->wctrlFlags & WHERE_DUPLICATES_OK)==0 ){

  138623.       if( HasRowid(pTab) ){

  138624.         regRowset = ++pParse->nMem;

  138625.         sqlite3VdbeAddOp2(v, OP_Null, 0, regRowset);

  138626.       }else{

  138627.         Index *pPk = sqlite3PrimaryKeyIndex(pTab);

  138628.         regRowset = pParse->nTab++;

  138629.         sqlite3VdbeAddOp2(v, OP_OpenEphemeral, regRowset, pPk->nKeyCol);

  138630.         sqlite3VdbeSetP4KeyInfo(pParse, pPk);

  138631.       }

  138632.       regRowid = ++pParse->nMem;

  138633.     }

  138634.     iRetInit = sqlite3VdbeAddOp2(v, OP_Integer, 0, regReturn);

  138635. 

  138636.     /* If the original WHERE clause is z of the form:  (x1 OR x2 OR ...) AND y

  138637.     ** Then for every term xN, evaluate as the subexpression: xN AND z

  138638.     ** That way, terms in y that are factored into the disjunction will

  138639.     ** be picked up by the recursive calls to sqlite3WhereBegin() below.

  138640.     **

  138641.     ** Actually, each subexpression is converted to "xN AND w" where w is

  138642.     ** the "interesting" terms of z - terms that did not originate in the

  138643.     ** ON or USING clause of a LEFT JOIN, and terms that are usable as 

  138644.     ** indices.

  138645.     **

  138646.     ** This optimization also only applies if the (x1 OR x2 OR ...) term

  138647.     ** is not contained in the ON clause of a LEFT JOIN.

  138648.     ** See ticket http://www.sqlite.org/src/info/f2369304e4

  138649.     */

  138650.     if( pWC->nTerm>1 ){

  138651.       int iTerm;

  138652.       for(iTerm=0; iTerm<pWC->nTerm; iTerm++){

  138653.         Expr *pExpr = pWC->a[iTerm].pExpr;

  138654.         if( &pWC->a[iTerm] == pTerm ) continue;

  138655.         testcase( pWC->a[iTerm].wtFlags & TERM_VIRTUAL );

  138656.         testcase( pWC->a[iTerm].wtFlags & TERM_CODED );

  138657.         if( (pWC->a[iTerm].wtFlags & (TERM_VIRTUAL|TERM_CODED))!=0 ) continue;

  138658.         if( (pWC->a[iTerm].eOperator & WO_ALL)==0 ) continue;

  138659.         testcase( pWC->a[iTerm].wtFlags & TERM_ORINFO );

  138660.         pExpr = sqlite3ExprDup(db, pExpr, 0);

  138661.         pAndExpr = sqlite3ExprAnd(pParse, pAndExpr, pExpr);

  138662.       }

  138663.       if( pAndExpr ){

  138664.         /* The extra 0x10000 bit on the opcode is masked off and does not

  138665.         ** become part of the new Expr.op.  However, it does make the

  138666.         ** op==TK_AND comparison inside of sqlite3PExpr() false, and this

  138667.         ** prevents sqlite3PExpr() from implementing AND short-circuit 

  138668.         ** optimization, which we do not want here. */

  138669.         pAndExpr = sqlite3PExpr(pParse, TK_AND|0x10000, 0, pAndExpr);

  138670.       }

  138671.     }

  138672. 

  138673.     /* Run a separate WHERE clause for each term of the OR clause.  After

  138674.     ** eliminating duplicates from other WHERE clauses, the action for each

  138675.     ** sub-WHERE clause is to to invoke the main loop body as a subroutine.

  138676.     */

  138677.     wctrlFlags =  WHERE_OR_SUBCLAUSE | (pWInfo->wctrlFlags & WHERE_SEEK_TABLE);

  138678.     ExplainQueryPlan((pParse, 1, "MULTI-INDEX OR"));

  138679.     for(ii=0; ii<pOrWc->nTerm; ii++){

  138680.       WhereTerm *pOrTerm = &pOrWc->a[ii];

  138681.       if( pOrTerm->leftCursor==iCur || (pOrTerm->eOperator & WO_AND)!=0 ){

  138682.         WhereInfo *pSubWInfo;           /* Info for single OR-term scan */

  138683.         Expr *pOrExpr = pOrTerm->pExpr; /* Current OR clause term */

  138684.         int jmp1 = 0;                   /* Address of jump operation */

  138685.         assert( (pTabItem[0].fg.jointype & JT_LEFT)==0 

  138686.              || ExprHasProperty(pOrExpr, EP_FromJoin) 

  138687.         );

  138688.         if( pAndExpr ){

  138689.           pAndExpr->pLeft = pOrExpr;

  138690.           pOrExpr = pAndExpr;

  138691.         }

  138692.         /* Loop through table entries that match term pOrTerm. */

  138693.         ExplainQueryPlan((pParse, 1, "INDEX %d", ii+1));

  138694.         WHERETRACE(0xffff, ("Subplan for OR-clause:\n"));

  138695.         pSubWInfo = sqlite3WhereBegin(pParse, pOrTab, pOrExpr, 0, 0,

  138696.                                       wctrlFlags, iCovCur);

  138697.         assert( pSubWInfo || pParse->nErr || db->mallocFailed );

  138698.         if( pSubWInfo ){

  138699.           WhereLoop *pSubLoop;

  138700.           int addrExplain = sqlite3WhereExplainOneScan(

  138701.               pParse, pOrTab, &pSubWInfo->a[0], 0

  138702.           );

  138703.           sqlite3WhereAddScanStatus(v, pOrTab, &pSubWInfo->a[0], addrExplain);

  138704. 

  138705.           /* This is the sub-WHERE clause body.  First skip over

  138706.           ** duplicate rows from prior sub-WHERE clauses, and record the

  138707.           ** rowid (or PRIMARY KEY) for the current row so that the same

  138708.           ** row will be skipped in subsequent sub-WHERE clauses.

  138709.           */

  138710.           if( (pWInfo->wctrlFlags & WHERE_DUPLICATES_OK)==0 ){

  138711.             int iSet = ((ii==pOrWc->nTerm-1)?-1:ii);

  138712.             if( HasRowid(pTab) ){

  138713.               sqlite3ExprCodeGetColumnOfTable(v, pTab, iCur, -1, regRowid);

  138714.               jmp1 = sqlite3VdbeAddOp4Int(v, OP_RowSetTest, regRowset, 0,

  138715.                                           regRowid, iSet);

  138716.               VdbeCoverage(v);

  138717.             }else{

  138718.               Index *pPk = sqlite3PrimaryKeyIndex(pTab);

  138719.               int nPk = pPk->nKeyCol;

  138720.               int iPk;

  138721.               int r;

  138722. 

  138723.               /* Read the PK into an array of temp registers. */

  138724.               r = sqlite3GetTempRange(pParse, nPk);

  138725.               for(iPk=0; iPk<nPk; iPk++){

  138726.                 int iCol = pPk->aiColumn[iPk];

  138727.                 sqlite3ExprCodeGetColumnOfTable(v, pTab, iCur, iCol, r+iPk);

  138728.               }

  138729. 

  138730.               /* Check if the temp table already contains this key. If so,

  138731.               ** the row has already been included in the result set and

  138732.               ** can be ignored (by jumping past the Gosub below). Otherwise,

  138733.               ** insert the key into the temp table and proceed with processing

  138734.               ** the row.

  138735.               **

  138736.               ** Use some of the same optimizations as OP_RowSetTest: If iSet

  138737.               ** is zero, assume that the key cannot already be present in

  138738.               ** the temp table. And if iSet is -1, assume that there is no 

  138739.               ** need to insert the key into the temp table, as it will never 

  138740.               ** be tested for.  */ 

  138741.               if( iSet ){

  138742.                 jmp1 = sqlite3VdbeAddOp4Int(v, OP_Found, regRowset, 0, r, nPk);

  138743.                 VdbeCoverage(v);

  138744.               }

  138745.               if( iSet>=0 ){

  138746.                 sqlite3VdbeAddOp3(v, OP_MakeRecord, r, nPk, regRowid);

  138747.                 sqlite3VdbeAddOp4Int(v, OP_IdxInsert, regRowset, regRowid,

  138748.                                      r, nPk);

  138749.                 if( iSet ) sqlite3VdbeChangeP5(v, OPFLAG_USESEEKRESULT);

  138750.               }

  138751. 

  138752.               /* Release the array of temp registers */

  138753.               sqlite3ReleaseTempRange(pParse, r, nPk);

  138754.             }

  138755.           }

  138756. 

  138757.           /* Invoke the main loop body as a subroutine */

  138758.           sqlite3VdbeAddOp2(v, OP_Gosub, regReturn, iLoopBody);

  138759. 

  138760.           /* Jump here (skipping the main loop body subroutine) if the

  138761.           ** current sub-WHERE row is a duplicate from prior sub-WHEREs. */

  138762.           if( jmp1 ) sqlite3VdbeJumpHere(v, jmp1);

  138763. 

  138764.           /* The pSubWInfo->untestedTerms flag means that this OR term

  138765.           ** contained one or more AND term from a notReady table.  The

  138766.           ** terms from the notReady table could not be tested and will

  138767.           ** need to be tested later.

  138768.           */

  138769.           if( pSubWInfo->untestedTerms ) untestedTerms = 1;

  138770. 

  138771.           /* If all of the OR-connected terms are optimized using the same

  138772.           ** index, and the index is opened using the same cursor number

  138773.           ** by each call to sqlite3WhereBegin() made by this loop, it may

  138774.           ** be possible to use that index as a covering index.

  138775.           **

  138776.           ** If the call to sqlite3WhereBegin() above resulted in a scan that

  138777.           ** uses an index, and this is either the first OR-connected term

  138778.           ** processed or the index is the same as that used by all previous

  138779.           ** terms, set pCov to the candidate covering index. Otherwise, set 

  138780.           ** pCov to NULL to indicate that no candidate covering index will 

  138781.           ** be available.

  138782.           */

  138783.           pSubLoop = pSubWInfo->a[0].pWLoop;

  138784.           assert( (pSubLoop->wsFlags & WHERE_AUTO_INDEX)==0 );

  138785.           if( (pSubLoop->wsFlags & WHERE_INDEXED)!=0

  138786.            && (ii==0 || pSubLoop->u.btree.pIndex==pCov)

  138787.            && (HasRowid(pTab) || !IsPrimaryKeyIndex(pSubLoop->u.btree.pIndex))

  138788.           ){

  138789.             assert( pSubWInfo->a[0].iIdxCur==iCovCur );

  138790.             pCov = pSubLoop->u.btree.pIndex;

  138791.           }else{

  138792.             pCov = 0;

  138793.           }

  138794. 

  138795.           /* Finish the loop through table entries that match term pOrTerm. */

  138796.           sqlite3WhereEnd(pSubWInfo);

  138797.           ExplainQueryPlanPop(pParse);

  138798.         }

  138799.       }

  138800.     }

  138801.     ExplainQueryPlanPop(pParse);

  138802.     pLevel->u.pCovidx = pCov;

  138803.     if( pCov ) pLevel->iIdxCur = iCovCur;

  138804.     if( pAndExpr ){

  138805.       pAndExpr->pLeft = 0;

  138806.       sqlite3ExprDelete(db, pAndExpr);

  138807.     }

  138808.     sqlite3VdbeChangeP1(v, iRetInit, sqlite3VdbeCurrentAddr(v));

  138809.     sqlite3VdbeGoto(v, pLevel->addrBrk);

  138810.     sqlite3VdbeResolveLabel(v, iLoopBody);

  138811. 

  138812.     if( pWInfo->nLevel>1 ){ sqlite3StackFree(db, pOrTab); }

  138813.     if( !untestedTerms ) disableTerm(pLevel, pTerm);

  138814.   }else

  138815. #endif /* SQLITE_OMIT_OR_OPTIMIZATION */

  138816. 

  138817.   {

  138818.     /* Case 6:  There is no usable index.  We must do a complete

  138819.     **          scan of the entire table.

  138820.     */

  138821.     static const u8 aStep[] = { OP_Next, OP_Prev };

  138822.     static const u8 aStart[] = { OP_Rewind, OP_Last };

  138823.     assert( bRev==0 || bRev==1 );

  138824.     if( pTabItem->fg.isRecursive ){

  138825.       /* Tables marked isRecursive have only a single row that is stored in

  138826.       ** a pseudo-cursor.  No need to Rewind or Next such cursors. */

  138827.       pLevel->op = OP_Noop;

  138828.     }else{

  138829.       codeCursorHint(pTabItem, pWInfo, pLevel, 0);

  138830.       pLevel->op = aStep[bRev];

  138831.       pLevel->p1 = iCur;

  138832.       pLevel->p2 = 1 + sqlite3VdbeAddOp2(v, aStart[bRev], iCur, addrHalt);

  138833.       VdbeCoverageIf(v, bRev==0);

  138834.       VdbeCoverageIf(v, bRev!=0);

  138835.       pLevel->p5 = SQLITE_STMTSTATUS_FULLSCAN_STEP;

  138836.     }

  138837.   }

  138838. 

  138839. #ifdef SQLITE_ENABLE_STMT_SCANSTATUS

  138840.   pLevel->addrVisit = sqlite3VdbeCurrentAddr(v);

  138841. #endif

  138842. 

  138843.   /* Insert code to test every subexpression that can be completely

  138844.   ** computed using the current set of tables.

  138845.   **

  138846.   ** This loop may run between one and three times, depending on the

  138847.   ** constraints to be generated. The value of stack variable iLoop

  138848.   ** determines the constraints coded by each iteration, as follows:

  138849.   **

  138850.   ** iLoop==1: Code only expressions that are entirely covered by pIdx.

  138851.   ** iLoop==2: Code remaining expressions that do not contain correlated

  138852.   **           sub-queries.  

  138853.   ** iLoop==3: Code all remaining expressions.

  138854.   **

  138855.   ** An effort is made to skip unnecessary iterations of the loop.

  138856.   */

  138857.   iLoop = (pIdx ? 1 : 2);

  138858.   do{

  138859.     int iNext = 0;                /* Next value for iLoop */

  138860.     for(pTerm=pWC->a, j=pWC->nTerm; j>0; j--, pTerm++){

  138861.       Expr *pE;

  138862.       int skipLikeAddr = 0;

  138863.       testcase( pTerm->wtFlags & TERM_VIRTUAL );

  138864.       testcase( pTerm->wtFlags & TERM_CODED );

  138865.       if( pTerm->wtFlags & (TERM_VIRTUAL|TERM_CODED) ) continue;

  138866.       if( (pTerm->prereqAll & pLevel->notReady)!=0 ){

  138867.         testcase( pWInfo->untestedTerms==0

  138868.             && (pWInfo->wctrlFlags & WHERE_OR_SUBCLAUSE)!=0 );

  138869.         pWInfo->untestedTerms = 1;

  138870.         continue;

  138871.       }

  138872.       pE = pTerm->pExpr;

  138873.       assert( pE!=0 );

  138874.       if( (pTabItem->fg.jointype&JT_LEFT) && !ExprHasProperty(pE,EP_FromJoin) ){

  138875.         continue;

  138876.       }

  138877.       

  138878.       if( iLoop==1 && !sqlite3ExprCoveredByIndex(pE, pLevel->iTabCur, pIdx) ){

  138879.         iNext = 2;

  138880.         continue;

  138881.       }

  138882.       if( iLoop<3 && (pTerm->wtFlags & TERM_VARSELECT) ){

  138883.         if( iNext==0 ) iNext = 3;

  138884.         continue;

  138885.       }

  138886. 

  138887.       if( (pTerm->wtFlags & TERM_LIKECOND)!=0 ){

  138888.         /* If the TERM_LIKECOND flag is set, that means that the range search

  138889.         ** is sufficient to guarantee that the LIKE operator is true, so we

  138890.         ** can skip the call to the like(A,B) function.  But this only works

  138891.         ** for strings.  So do not skip the call to the function on the pass

  138892.         ** that compares BLOBs. */

  138893. #ifdef SQLITE_LIKE_DOESNT_MATCH_BLOBS

  138894.         continue;

  138895. #else

  138896.         u32 x = pLevel->iLikeRepCntr;

  138897.         if( x>0 ){

  138898.           skipLikeAddr = sqlite3VdbeAddOp1(v, (x&1)?OP_IfNot:OP_If,(int)(x>>1));

  138899.           VdbeCoverageIf(v, (x&1)==1);

  138900.           VdbeCoverageIf(v, (x&1)==0);

  138901.         }

  138902. #endif

  138903.       }

  138904. #ifdef WHERETRACE_ENABLED /* 0xffff */

  138905.       if( sqlite3WhereTrace ){

  138906.         VdbeNoopComment((v, "WhereTerm[%d] (%p) priority=%d",

  138907.                          pWC->nTerm-j, pTerm, iLoop));

  138908.       }

  138909. #endif

  138910.       sqlite3ExprIfFalse(pParse, pE, addrCont, SQLITE_JUMPIFNULL);

  138911.       if( skipLikeAddr ) sqlite3VdbeJumpHere(v, skipLikeAddr);

  138912.       pTerm->wtFlags |= TERM_CODED;

  138913.     }

  138914.     iLoop = iNext;

  138915.   }while( iLoop>0 );

  138916. 

  138917.   /* Insert code to test for implied constraints based on transitivity

  138918.   ** of the "==" operator.

  138919.   **

  138920.   ** Example: If the WHERE clause contains "t1.a=t2.b" and "t2.b=123"

  138921.   ** and we are coding the t1 loop and the t2 loop has not yet coded,

  138922.   ** then we cannot use the "t1.a=t2.b" constraint, but we can code

  138923.   ** the implied "t1.a=123" constraint.

  138924.   */

  138925.   for(pTerm=pWC->a, j=pWC->nTerm; j>0; j--, pTerm++){

  138926.     Expr *pE, sEAlt;

  138927.     WhereTerm *pAlt;

  138928.     if( pTerm->wtFlags & (TERM_VIRTUAL|TERM_CODED) ) continue;

  138929.     if( (pTerm->eOperator & (WO_EQ|WO_IS))==0 ) continue;

  138930.     if( (pTerm->eOperator & WO_EQUIV)==0 ) continue;

  138931.     if( pTerm->leftCursor!=iCur ) continue;

  138932.     if( pLevel->iLeftJoin ) continue;

  138933.     pE = pTerm->pExpr;

  138934.     assert( !ExprHasProperty(pE, EP_FromJoin) );

  138935.     assert( (pTerm->prereqRight & pLevel->notReady)!=0 );

  138936.     pAlt = sqlite3WhereFindTerm(pWC, iCur, pTerm->u.leftColumn, notReady,

  138937.                     WO_EQ|WO_IN|WO_IS, 0);

  138938.     if( pAlt==0 ) continue;

  138939.     if( pAlt->wtFlags & (TERM_CODED) ) continue;

  138940.     if( (pAlt->eOperator & WO_IN) 

  138941.      && (pAlt->pExpr->flags & EP_xIsSelect)

  138942.      && (pAlt->pExpr->x.pSelect->pEList->nExpr>1)

  138943.     ){

  138944.       continue;

  138945.     }

  138946.     testcase( pAlt->eOperator & WO_EQ );

  138947.     testcase( pAlt->eOperator & WO_IS );

  138948.     testcase( pAlt->eOperator & WO_IN );

  138949.     VdbeModuleComment((v, "begin transitive constraint"));

  138950.     sEAlt = *pAlt->pExpr;

  138951.     sEAlt.pLeft = pE->pLeft;

  138952.     sqlite3ExprIfFalse(pParse, &sEAlt, addrCont, SQLITE_JUMPIFNULL);

  138953.   }

  138954. 

  138955.   /* For a LEFT OUTER JOIN, generate code that will record the fact that

  138956.   ** at least one row of the right table has matched the left table.  

  138957.   */

  138958.   if( pLevel->iLeftJoin ){

  138959.     pLevel->addrFirst = sqlite3VdbeCurrentAddr(v);

  138960.     sqlite3VdbeAddOp2(v, OP_Integer, 1, pLevel->iLeftJoin);

  138961.     VdbeComment((v, "record LEFT JOIN hit"));

  138962.     for(pTerm=pWC->a, j=0; j<pWC->nTerm; j++, pTerm++){

  138963.       testcase( pTerm->wtFlags & TERM_VIRTUAL );

  138964.       testcase( pTerm->wtFlags & TERM_CODED );

  138965.       if( pTerm->wtFlags & (TERM_VIRTUAL|TERM_CODED) ) continue;

  138966.       if( (pTerm->prereqAll & pLevel->notReady)!=0 ){

  138967.         assert( pWInfo->untestedTerms );

  138968.         continue;

  138969.       }

  138970.       assert( pTerm->pExpr );

  138971.       sqlite3ExprIfFalse(pParse, pTerm->pExpr, addrCont, SQLITE_JUMPIFNULL);

  138972.       pTerm->wtFlags |= TERM_CODED;

  138973.     }

  138974.   }

  138975. 

  138976.   return pLevel->notReady;

  138977. }

  138978. 

  138979. /************** End of wherecode.c *******************************************/

  138980. /************** Begin file whereexpr.c ***************************************/

  138981. /*

  138982. ** 2015-06-08

  138983. **

  138984. ** The author disclaims copyright to this source code.  In place of

  138985. ** a legal notice, here is a blessing:

  138986. **

  138987. **    May you do good and not evil.

  138988. **    May you find forgiveness for yourself and forgive others.

  138989. **    May you share freely, never taking more than you give.

  138990. **

  138991. *************************************************************************

  138992. ** This module contains C code that generates VDBE code used to process

  138993. ** the WHERE clause of SQL statements.

  138994. **

  138995. ** This file was originally part of where.c but was split out to improve

  138996. ** readability and editabiliity.  This file contains utility routines for

  138997. ** analyzing Expr objects in the WHERE clause.

  138998. */

  138999. /* #include "sqliteInt.h" */

  139000. /* #include "whereInt.h" */

  139001. 

  139002. /* Forward declarations */

  139003. static void exprAnalyze(SrcList*, WhereClause*, int);

  139004. 

  139005. /*

  139006. ** Deallocate all memory associated with a WhereOrInfo object.

  139007. */

  139008. static void whereOrInfoDelete(sqlite3 *db, WhereOrInfo *p){

  139009.   sqlite3WhereClauseClear(&p->wc);

  139010.   sqlite3DbFree(db, p);

  139011. }

  139012. 

  139013. /*

  139014. ** Deallocate all memory associated with a WhereAndInfo object.

  139015. */

  139016. static void whereAndInfoDelete(sqlite3 *db, WhereAndInfo *p){

  139017.   sqlite3WhereClauseClear(&p->wc);

  139018.   sqlite3DbFree(db, p);

  139019. }

  139020. 

  139021. /*

  139022. ** Add a single new WhereTerm entry to the WhereClause object pWC.

  139023. ** The new WhereTerm object is constructed from Expr p and with wtFlags.

  139024. ** The index in pWC->a[] of the new WhereTerm is returned on success.

  139025. ** 0 is returned if the new WhereTerm could not be added due to a memory

  139026. ** allocation error.  The memory allocation failure will be recorded in

  139027. ** the db->mallocFailed flag so that higher-level functions can detect it.

  139028. **

  139029. ** This routine will increase the size of the pWC->a[] array as necessary.

  139030. **

  139031. ** If the wtFlags argument includes TERM_DYNAMIC, then responsibility

  139032. ** for freeing the expression p is assumed by the WhereClause object pWC.

  139033. ** This is true even if this routine fails to allocate a new WhereTerm.

  139034. **

  139035. ** WARNING:  This routine might reallocate the space used to store

  139036. ** WhereTerms.  All pointers to WhereTerms should be invalidated after

  139037. ** calling this routine.  Such pointers may be reinitialized by referencing

  139038. ** the pWC->a[] array.

  139039. */

  139040. static int whereClauseInsert(WhereClause *pWC, Expr *p, u16 wtFlags){

  139041.   WhereTerm *pTerm;

  139042.   int idx;

  139043.   testcase( wtFlags & TERM_VIRTUAL );

  139044.   if( pWC->nTerm>=pWC->nSlot ){

  139045.     WhereTerm *pOld = pWC->a;

  139046.     sqlite3 *db = pWC->pWInfo->pParse->db;

  139047.     pWC->a = sqlite3DbMallocRawNN(db, sizeof(pWC->a[0])*pWC->nSlot*2 );

  139048.     if( pWC->a==0 ){

  139049.       if( wtFlags & TERM_DYNAMIC ){

  139050.         sqlite3ExprDelete(db, p);

  139051.       }

  139052.       pWC->a = pOld;

  139053.       return 0;

  139054.     }

  139055.     memcpy(pWC->a, pOld, sizeof(pWC->a[0])*pWC->nTerm);

  139056.     if( pOld!=pWC->aStatic ){

  139057.       sqlite3DbFree(db, pOld);

  139058.     }

  139059.     pWC->nSlot = sqlite3DbMallocSize(db, pWC->a)/sizeof(pWC->a[0]);

  139060.   }

  139061.   pTerm = &pWC->a[idx = pWC->nTerm++];

  139062.   if( p && ExprHasProperty(p, EP_Unlikely) ){

  139063.     pTerm->truthProb = sqlite3LogEst(p->iTable) - 270;

  139064.   }else{

  139065.     pTerm->truthProb = 1;

  139066.   }

  139067.   pTerm->pExpr = sqlite3ExprSkipCollate(p);

  139068.   pTerm->wtFlags = wtFlags;

  139069.   pTerm->pWC = pWC;

  139070.   pTerm->iParent = -1;

  139071.   memset(&pTerm->eOperator, 0,

  139072.          sizeof(WhereTerm) - offsetof(WhereTerm,eOperator));

  139073.   return idx;

  139074. }

  139075. 

  139076. /*

  139077. ** Return TRUE if the given operator is one of the operators that is

  139078. ** allowed for an indexable WHERE clause term.  The allowed operators are

  139079. ** "=", "<", ">", "<=", ">=", "IN", "IS", and "IS NULL"

  139080. */

  139081. static int allowedOp(int op){

  139082.   assert( TK_GT>TK_EQ && TK_GT<TK_GE );

  139083.   assert( TK_LT>TK_EQ && TK_LT<TK_GE );

  139084.   assert( TK_LE>TK_EQ && TK_LE<TK_GE );

  139085.   assert( TK_GE==TK_EQ+4 );

  139086.   return op==TK_IN || (op>=TK_EQ && op<=TK_GE) || op==TK_ISNULL || op==TK_IS;

  139087. }

  139088. 

  139089. /*

  139090. ** Commute a comparison operator.  Expressions of the form "X op Y"

  139091. ** are converted into "Y op X".

  139092. **

  139093. ** If left/right precedence rules come into play when determining the

  139094. ** collating sequence, then COLLATE operators are adjusted to ensure

  139095. ** that the collating sequence does not change.  For example:

  139096. ** "Y collate NOCASE op X" becomes "X op Y" because any collation sequence on

  139097. ** the left hand side of a comparison overrides any collation sequence 

  139098. ** attached to the right. For the same reason the EP_Collate flag

  139099. ** is not commuted.

  139100. */

  139101. static void exprCommute(Parse *pParse, Expr *pExpr){

  139102.   u16 expRight = (pExpr->pRight->flags & EP_Collate);

  139103.   u16 expLeft = (pExpr->pLeft->flags & EP_Collate);

  139104.   assert( allowedOp(pExpr->op) && pExpr->op!=TK_IN );

  139105.   if( expRight==expLeft ){

  139106.     /* Either X and Y both have COLLATE operator or neither do */

  139107.     if( expRight ){

  139108.       /* Both X and Y have COLLATE operators.  Make sure X is always

  139109.       ** used by clearing the EP_Collate flag from Y. */

  139110.       pExpr->pRight->flags &= ~EP_Collate;

  139111.     }else if( sqlite3ExprCollSeq(pParse, pExpr->pLeft)!=0 ){

  139112.       /* Neither X nor Y have COLLATE operators, but X has a non-default

  139113.       ** collating sequence.  So add the EP_Collate marker on X to cause

  139114.       ** it to be searched first. */

  139115.       pExpr->pLeft->flags |= EP_Collate;

  139116.     }

  139117.   }

  139118.   SWAP(Expr*,pExpr->pRight,pExpr->pLeft);

  139119.   if( pExpr->op>=TK_GT ){

  139120.     assert( TK_LT==TK_GT+2 );

  139121.     assert( TK_GE==TK_LE+2 );

  139122.     assert( TK_GT>TK_EQ );

  139123.     assert( TK_GT<TK_LE );

  139124.     assert( pExpr->op>=TK_GT && pExpr->op<=TK_GE );

  139125.     pExpr->op = ((pExpr->op-TK_GT)^2)+TK_GT;

  139126.   }

  139127. }

  139128. 

  139129. /*

  139130. ** Translate from TK_xx operator to WO_xx bitmask.

  139131. */

  139132. static u16 operatorMask(int op){

  139133.   u16 c;

  139134.   assert( allowedOp(op) );

  139135.   if( op==TK_IN ){

  139136.     c = WO_IN;

  139137.   }else if( op==TK_ISNULL ){

  139138.     c = WO_ISNULL;

  139139.   }else if( op==TK_IS ){

  139140.     c = WO_IS;

  139141.   }else{

  139142.     assert( (WO_EQ<<(op-TK_EQ)) < 0x7fff );

  139143.     c = (u16)(WO_EQ<<(op-TK_EQ));

  139144.   }

  139145.   assert( op!=TK_ISNULL || c==WO_ISNULL );

  139146.   assert( op!=TK_IN || c==WO_IN );

  139147.   assert( op!=TK_EQ || c==WO_EQ );

  139148.   assert( op!=TK_LT || c==WO_LT );

  139149.   assert( op!=TK_LE || c==WO_LE );

  139150.   assert( op!=TK_GT || c==WO_GT );

  139151.   assert( op!=TK_GE || c==WO_GE );

  139152.   assert( op!=TK_IS || c==WO_IS );

  139153.   return c;

  139154. }

  139155. 

  139156. 

  139157. #ifndef SQLITE_OMIT_LIKE_OPTIMIZATION

  139158. /*

  139159. ** Check to see if the given expression is a LIKE or GLOB operator that

  139160. ** can be optimized using inequality constraints.  Return TRUE if it is

  139161. ** so and false if not.

  139162. **

  139163. ** In order for the operator to be optimizible, the RHS must be a string

  139164. ** literal that does not begin with a wildcard.  The LHS must be a column

  139165. ** that may only be NULL, a string, or a BLOB, never a number. (This means

  139166. ** that virtual tables cannot participate in the LIKE optimization.)  The

  139167. ** collating sequence for the column on the LHS must be appropriate for

  139168. ** the operator.

  139169. */

  139170. static int isLikeOrGlob(

  139171.   Parse *pParse,    /* Parsing and code generating context */

  139172.   Expr *pExpr,      /* Test this expression */

  139173.   Expr **ppPrefix,  /* Pointer to TK_STRING expression with pattern prefix */

  139174.   int *pisComplete, /* True if the only wildcard is % in the last character */

  139175.   int *pnoCase      /* True if uppercase is equivalent to lowercase */

  139176. ){

  139177.   const u8 *z = 0;           /* String on RHS of LIKE operator */

  139178.   Expr *pRight, *pLeft;      /* Right and left size of LIKE operator */

  139179.   ExprList *pList;           /* List of operands to the LIKE operator */

  139180.   u8 c;                      /* One character in z[] */

  139181.   int cnt;                   /* Number of non-wildcard prefix characters */

  139182.   u8 wc[4];                  /* Wildcard characters */

  139183.   sqlite3 *db = pParse->db;  /* Database connection */

  139184.   sqlite3_value *pVal = 0;

  139185.   int op;                    /* Opcode of pRight */

  139186.   int rc;                    /* Result code to return */

  139187. 

  139188.   if( !sqlite3IsLikeFunction(db, pExpr, pnoCase, (char*)wc) ){

  139189.     return 0;

  139190.   }

  139191. #ifdef SQLITE_EBCDIC

  139192.   if( *pnoCase ) return 0;

  139193. #endif

  139194.   pList = pExpr->x.pList;

  139195.   pLeft = pList->a[1].pExpr;

  139196. 

  139197.   pRight = sqlite3ExprSkipCollate(pList->a[0].pExpr);

  139198.   op = pRight->op;

  139199.   if( op==TK_VARIABLE && (db->flags & SQLITE_EnableQPSG)==0 ){

  139200.     Vdbe *pReprepare = pParse->pReprepare;

  139201.     int iCol = pRight->iColumn;

  139202.     pVal = sqlite3VdbeGetBoundValue(pReprepare, iCol, SQLITE_AFF_BLOB);

  139203.     if( pVal && sqlite3_value_type(pVal)==SQLITE_TEXT ){

  139204.       z = sqlite3_value_text(pVal);

  139205.     }

  139206.     sqlite3VdbeSetVarmask(pParse->pVdbe, iCol);

  139207.     assert( pRight->op==TK_VARIABLE || pRight->op==TK_REGISTER );

  139208.   }else if( op==TK_STRING ){

  139209.     z = (u8*)pRight->u.zToken;

  139210.   }

  139211.   if( z ){

  139212. 

  139213.     /* Count the number of prefix characters prior to the first wildcard */

  139214.     cnt = 0;

  139215.     while( (c=z[cnt])!=0 && c!=wc[0] && c!=wc[1] && c!=wc[2] ){

  139216.       cnt++;

  139217.       if( c==wc[3] && z[cnt]!=0 ) cnt++;

  139218.     }

  139219. 

  139220.     /* The optimization is possible only if (1) the pattern does not begin

  139221.     ** with a wildcard and if (2) the non-wildcard prefix does not end with

  139222.     ** an (illegal 0xff) character, or (3) the pattern does not consist of

  139223.     ** a single escape character. The second condition is necessary so

  139224.     ** that we can increment the prefix key to find an upper bound for the

  139225.     ** range search. The third is because the caller assumes that the pattern

  139226.     ** consists of at least one character after all escapes have been

  139227.     ** removed.  */

  139228.     if( cnt!=0 && 255!=(u8)z[cnt-1] && (cnt>1 || z[0]!=wc[3]) ){

  139229.       Expr *pPrefix;

  139230. 

  139231.       /* A "complete" match if the pattern ends with "*" or "%" */

  139232.       *pisComplete = c==wc[0] && z[cnt+1]==0;

  139233. 

  139234.       /* Get the pattern prefix.  Remove all escapes from the prefix. */

  139235.       pPrefix = sqlite3Expr(db, TK_STRING, (char*)z);

  139236.       if( pPrefix ){

  139237.         int iFrom, iTo;

  139238.         char *zNew = pPrefix->u.zToken;

  139239.         zNew[cnt] = 0;

  139240.         for(iFrom=iTo=0; iFrom<cnt; iFrom++){

  139241.           if( zNew[iFrom]==wc[3] ) iFrom++;

  139242.           zNew[iTo++] = zNew[iFrom];

  139243.         }

  139244.         zNew[iTo] = 0;

  139245.         assert( iTo>0 );

  139246. 

  139247.         /* If the LHS is not an ordinary column with TEXT affinity, then the

  139248.         ** pattern prefix boundaries (both the start and end boundaries) must

  139249.         ** not look like a number.  Otherwise the pattern might be treated as

  139250.         ** a number, which will invalidate the LIKE optimization.

  139251.         **

  139252.         ** Getting this right has been a persistent source of bugs in the

  139253.         ** LIKE optimization.  See, for example:

  139254.         **    2018-09-10 https://sqlite.org/src/info/c94369cae9b561b1

  139255.         **    2019-05-02 https://sqlite.org/src/info/b043a54c3de54b28

  139256.         **    2019-06-10 https://sqlite.org/src/info/fd76310a5e843e07

  139257.         **    2019-06-14 https://sqlite.org/src/info/ce8717f0885af975

  139258.         */

  139259.         if( pLeft->op!=TK_COLUMN 

  139260.          || sqlite3ExprAffinity(pLeft)!=SQLITE_AFF_TEXT 

  139261.          || IsVirtual(pLeft->y.pTab)  /* Value might be numeric */

  139262.         ){

  139263.           int isNum;

  139264.           double rDummy;

  139265.           isNum = sqlite3AtoF(zNew, &rDummy, iTo, SQLITE_UTF8);

  139266.           if( isNum<=0 ){

  139267.             zNew[iTo-1]++;

  139268.             isNum = sqlite3AtoF(zNew, &rDummy, iTo, SQLITE_UTF8);

  139269.             zNew[iTo-1]--;

  139270.           }

  139271.           if( isNum>0 ){

  139272.             sqlite3ExprDelete(db, pPrefix);

  139273.             sqlite3ValueFree(pVal);

  139274.             return 0;

  139275.           }

  139276.         }

  139277.       }

  139278.       *ppPrefix = pPrefix;

  139279. 

  139280.       /* If the RHS pattern is a bound parameter, make arrangements to

  139281.       ** reprepare the statement when that parameter is rebound */

  139282.       if( op==TK_VARIABLE ){

  139283.         Vdbe *v = pParse->pVdbe;

  139284.         sqlite3VdbeSetVarmask(v, pRight->iColumn);

  139285.         if( *pisComplete && pRight->u.zToken[1] ){

  139286.           /* If the rhs of the LIKE expression is a variable, and the current

  139287.           ** value of the variable means there is no need to invoke the LIKE

  139288.           ** function, then no OP_Variable will be added to the program.

  139289.           ** This causes problems for the sqlite3_bind_parameter_name()

  139290.           ** API. To work around them, add a dummy OP_Variable here.

  139291.           */ 

  139292.           int r1 = sqlite3GetTempReg(pParse);

  139293.           sqlite3ExprCodeTarget(pParse, pRight, r1);

  139294.           sqlite3VdbeChangeP3(v, sqlite3VdbeCurrentAddr(v)-1, 0);

  139295.           sqlite3ReleaseTempReg(pParse, r1);

  139296.         }

  139297.       }

  139298.     }else{

  139299.       z = 0;

  139300.     }

  139301.   }

  139302. 

  139303.   rc = (z!=0);

  139304.   sqlite3ValueFree(pVal);

  139305.   return rc;

  139306. }

  139307. #endif /* SQLITE_OMIT_LIKE_OPTIMIZATION */

  139308. 

  139309. 

  139310. #ifndef SQLITE_OMIT_VIRTUALTABLE

  139311. /*

  139312. ** Check to see if the pExpr expression is a form that needs to be passed

  139313. ** to the xBestIndex method of virtual tables.  Forms of interest include:

  139314. **

  139315. **          Expression                   Virtual Table Operator

  139316. **          -----------------------      ---------------------------------

  139317. **      1.  column MATCH expr            SQLITE_INDEX_CONSTRAINT_MATCH

  139318. **      2.  column GLOB expr             SQLITE_INDEX_CONSTRAINT_GLOB

  139319. **      3.  column LIKE expr             SQLITE_INDEX_CONSTRAINT_LIKE

  139320. **      4.  column REGEXP expr           SQLITE_INDEX_CONSTRAINT_REGEXP

  139321. **      5.  column != expr               SQLITE_INDEX_CONSTRAINT_NE

  139322. **      6.  expr != column               SQLITE_INDEX_CONSTRAINT_NE

  139323. **      7.  column IS NOT expr           SQLITE_INDEX_CONSTRAINT_ISNOT

  139324. **      8.  expr IS NOT column           SQLITE_INDEX_CONSTRAINT_ISNOT

  139325. **      9.  column IS NOT NULL           SQLITE_INDEX_CONSTRAINT_ISNOTNULL

  139326. **

  139327. ** In every case, "column" must be a column of a virtual table.  If there

  139328. ** is a match, set *ppLeft to the "column" expression, set *ppRight to the 

  139329. ** "expr" expression (even though in forms (6) and (8) the column is on the

  139330. ** right and the expression is on the left).  Also set *peOp2 to the

  139331. ** appropriate virtual table operator.  The return value is 1 or 2 if there

  139332. ** is a match.  The usual return is 1, but if the RHS is also a column

  139333. ** of virtual table in forms (5) or (7) then return 2.

  139334. **

  139335. ** If the expression matches none of the patterns above, return 0.

  139336. */

  139337. static int isAuxiliaryVtabOperator(

  139338.   sqlite3 *db,                    /* Parsing context */

  139339.   Expr *pExpr,                    /* Test this expression */

  139340.   unsigned char *peOp2,           /* OUT: 0 for MATCH, or else an op2 value */

  139341.   Expr **ppLeft,                  /* Column expression to left of MATCH/op2 */

  139342.   Expr **ppRight                  /* Expression to left of MATCH/op2 */

  139343. ){

  139344.   if( pExpr->op==TK_FUNCTION ){

  139345.     static const struct Op2 {

  139346.       const char *zOp;

  139347.       unsigned char eOp2;

  139348.     } aOp[] = {

  139349.       { "match",  SQLITE_INDEX_CONSTRAINT_MATCH },

  139350.       { "glob",   SQLITE_INDEX_CONSTRAINT_GLOB },

  139351.       { "like",   SQLITE_INDEX_CONSTRAINT_LIKE },

  139352.       { "regexp", SQLITE_INDEX_CONSTRAINT_REGEXP }

  139353.     };

  139354.     ExprList *pList;

  139355.     Expr *pCol;                     /* Column reference */

  139356.     int i;

  139357. 

  139358.     pList = pExpr->x.pList;

  139359.     if( pList==0 || pList->nExpr!=2 ){

  139360.       return 0;

  139361.     }

  139362. 

  139363.     /* Built-in operators MATCH, GLOB, LIKE, and REGEXP attach to a

  139364.     ** virtual table on their second argument, which is the same as

  139365.     ** the left-hand side operand in their in-fix form.

  139366.     **

  139367.     **       vtab_column MATCH expression

  139368.     **       MATCH(expression,vtab_column)

  139369.     */

  139370.     pCol = pList->a[1].pExpr;

  139371.     if( pCol->op==TK_COLUMN && IsVirtual(pCol->y.pTab) ){

  139372.       for(i=0; i<ArraySize(aOp); i++){

  139373.         if( sqlite3StrICmp(pExpr->u.zToken, aOp[i].zOp)==0 ){

  139374.           *peOp2 = aOp[i].eOp2;

  139375.           *ppRight = pList->a[0].pExpr;

  139376.           *ppLeft = pCol;

  139377.           return 1;

  139378.         }

  139379.       }

  139380.     }

  139381. 

  139382.     /* We can also match against the first column of overloaded

  139383.     ** functions where xFindFunction returns a value of at least

  139384.     ** SQLITE_INDEX_CONSTRAINT_FUNCTION.

  139385.     **

  139386.     **      OVERLOADED(vtab_column,expression)

  139387.     **

  139388.     ** Historically, xFindFunction expected to see lower-case function

  139389.     ** names.  But for this use case, xFindFunction is expected to deal

  139390.     ** with function names in an arbitrary case.

  139391.     */

  139392.     pCol = pList->a[0].pExpr;

  139393.     if( pCol->op==TK_COLUMN && IsVirtual(pCol->y.pTab) ){

  139394.       sqlite3_vtab *pVtab;

  139395.       sqlite3_module *pMod;

  139396.       void (*xNotUsed)(sqlite3_context*,int,sqlite3_value**);

  139397.       void *pNotUsed;

  139398.       pVtab = sqlite3GetVTable(db, pCol->y.pTab)->pVtab;

  139399.       assert( pVtab!=0 );

  139400.       assert( pVtab->pModule!=0 );

  139401.       pMod = (sqlite3_module *)pVtab->pModule;

  139402.       if( pMod->xFindFunction!=0 ){

  139403.         i = pMod->xFindFunction(pVtab,2, pExpr->u.zToken, &xNotUsed, &pNotUsed);

  139404.         if( i>=SQLITE_INDEX_CONSTRAINT_FUNCTION ){

  139405.           *peOp2 = i;

  139406.           *ppRight = pList->a[1].pExpr;

  139407.           *ppLeft = pCol;

  139408.           return 1;

  139409.         }

  139410.       }

  139411.     }

  139412.   }else if( pExpr->op==TK_NE || pExpr->op==TK_ISNOT || pExpr->op==TK_NOTNULL ){

  139413.     int res = 0;

  139414.     Expr *pLeft = pExpr->pLeft;

  139415.     Expr *pRight = pExpr->pRight;

  139416.     if( pLeft->op==TK_COLUMN && IsVirtual(pLeft->y.pTab) ){

  139417.       res++;

  139418.     }

  139419.     if( pRight && pRight->op==TK_COLUMN && IsVirtual(pRight->y.pTab) ){

  139420.       res++;

  139421.       SWAP(Expr*, pLeft, pRight);

  139422.     }

  139423.     *ppLeft = pLeft;

  139424.     *ppRight = pRight;

  139425.     if( pExpr->op==TK_NE ) *peOp2 = SQLITE_INDEX_CONSTRAINT_NE;

  139426.     if( pExpr->op==TK_ISNOT ) *peOp2 = SQLITE_INDEX_CONSTRAINT_ISNOT;

  139427.     if( pExpr->op==TK_NOTNULL ) *peOp2 = SQLITE_INDEX_CONSTRAINT_ISNOTNULL;

  139428.     return res;

  139429.   }

  139430.   return 0;

  139431. }

  139432. #endif /* SQLITE_OMIT_VIRTUALTABLE */

  139433. 

  139434. /*

  139435. ** If the pBase expression originated in the ON or USING clause of

  139436. ** a join, then transfer the appropriate markings over to derived.

  139437. */

  139438. static void transferJoinMarkings(Expr *pDerived, Expr *pBase){

  139439.   if( pDerived ){

  139440.     pDerived->flags |= pBase->flags & EP_FromJoin;

  139441.     pDerived->iRightJoinTable = pBase->iRightJoinTable;

  139442.   }

  139443. }

  139444. 

  139445. /*

  139446. ** Mark term iChild as being a child of term iParent

  139447. */

  139448. static void markTermAsChild(WhereClause *pWC, int iChild, int iParent){

  139449.   pWC->a[iChild].iParent = iParent;

  139450.   pWC->a[iChild].truthProb = pWC->a[iParent].truthProb;

  139451.   pWC->a[iParent].nChild++;

  139452. }

  139453. 

  139454. /*

  139455. ** Return the N-th AND-connected subterm of pTerm.  Or if pTerm is not

  139456. ** a conjunction, then return just pTerm when N==0.  If N is exceeds

  139457. ** the number of available subterms, return NULL.

  139458. */

  139459. static WhereTerm *whereNthSubterm(WhereTerm *pTerm, int N){

  139460.   if( pTerm->eOperator!=WO_AND ){

  139461.     return N==0 ? pTerm : 0;

  139462.   }

  139463.   if( N<pTerm->u.pAndInfo->wc.nTerm ){

  139464.     return &pTerm->u.pAndInfo->wc.a[N];

  139465.   }

  139466.   return 0;

  139467. }

  139468. 

  139469. /*

  139470. ** Subterms pOne and pTwo are contained within WHERE clause pWC.  The

  139471. ** two subterms are in disjunction - they are OR-ed together.

  139472. **

  139473. ** If these two terms are both of the form:  "A op B" with the same

  139474. ** A and B values but different operators and if the operators are

  139475. ** compatible (if one is = and the other is <, for example) then

  139476. ** add a new virtual AND term to pWC that is the combination of the

  139477. ** two.

  139478. **

  139479. ** Some examples:

  139480. **

  139481. **    x<y OR x=y    -->     x<=y

  139482. **    x=y OR x=y    -->     x=y

  139483. **    x<=y OR x<y   -->     x<=y

  139484. **

  139485. ** The following is NOT generated:

  139486. **

  139487. **    x<y OR x>y    -->     x!=y     

  139488. */

  139489. static void whereCombineDisjuncts(

  139490.   SrcList *pSrc,         /* the FROM clause */

  139491.   WhereClause *pWC,      /* The complete WHERE clause */

  139492.   WhereTerm *pOne,       /* First disjunct */

  139493.   WhereTerm *pTwo        /* Second disjunct */

  139494. ){

  139495.   u16 eOp = pOne->eOperator | pTwo->eOperator;

  139496.   sqlite3 *db;           /* Database connection (for malloc) */

  139497.   Expr *pNew;            /* New virtual expression */

  139498.   int op;                /* Operator for the combined expression */

  139499.   int idxNew;            /* Index in pWC of the next virtual term */

  139500. 

  139501.   if( (pOne->eOperator & (WO_EQ|WO_LT|WO_LE|WO_GT|WO_GE))==0 ) return;

  139502.   if( (pTwo->eOperator & (WO_EQ|WO_LT|WO_LE|WO_GT|WO_GE))==0 ) return;

  139503.   if( (eOp & (WO_EQ|WO_LT|WO_LE))!=eOp

  139504.    && (eOp & (WO_EQ|WO_GT|WO_GE))!=eOp ) return;

  139505.   assert( pOne->pExpr->pLeft!=0 && pOne->pExpr->pRight!=0 );

  139506.   assert( pTwo->pExpr->pLeft!=0 && pTwo->pExpr->pRight!=0 );

  139507.   if( sqlite3ExprCompare(0,pOne->pExpr->pLeft, pTwo->pExpr->pLeft, -1) ) return;

  139508.   if( sqlite3ExprCompare(0,pOne->pExpr->pRight, pTwo->pExpr->pRight,-1) )return;

  139509.   /* If we reach this point, it means the two subterms can be combined */

  139510.   if( (eOp & (eOp-1))!=0 ){

  139511.     if( eOp & (WO_LT|WO_LE) ){

  139512.       eOp = WO_LE;

  139513.     }else{

  139514.       assert( eOp & (WO_GT|WO_GE) );

  139515.       eOp = WO_GE;

  139516.     }

  139517.   }

  139518.   db = pWC->pWInfo->pParse->db;

  139519.   pNew = sqlite3ExprDup(db, pOne->pExpr, 0);

  139520.   if( pNew==0 ) return;

  139521.   for(op=TK_EQ; eOp!=(WO_EQ<<(op-TK_EQ)); op++){ assert( op<TK_GE ); }

  139522.   pNew->op = op;

  139523.   idxNew = whereClauseInsert(pWC, pNew, TERM_VIRTUAL|TERM_DYNAMIC);

  139524.   exprAnalyze(pSrc, pWC, idxNew);

  139525. }

  139526. 

  139527. #if !defined(SQLITE_OMIT_OR_OPTIMIZATION) && !defined(SQLITE_OMIT_SUBQUERY)

  139528. /*

  139529. ** Analyze a term that consists of two or more OR-connected

  139530. ** subterms.  So in:

  139531. **

  139532. **     ... WHERE  (a=5) AND (b=7 OR c=9 OR d=13) AND (d=13)

  139533. **                          ^^^^^^^^^^^^^^^^^^^^

  139534. **

  139535. ** This routine analyzes terms such as the middle term in the above example.

  139536. ** A WhereOrTerm object is computed and attached to the term under

  139537. ** analysis, regardless of the outcome of the analysis.  Hence:

  139538. **

  139539. **     WhereTerm.wtFlags   |=  TERM_ORINFO

  139540. **     WhereTerm.u.pOrInfo  =  a dynamically allocated WhereOrTerm object

  139541. **

  139542. ** The term being analyzed must have two or more of OR-connected subterms.

  139543. ** A single subterm might be a set of AND-connected sub-subterms.

  139544. ** Examples of terms under analysis:

  139545. **

  139546. **     (A)     t1.x=t2.y OR t1.x=t2.z OR t1.y=15 OR t1.z=t3.a+5

  139547. **     (B)     x=expr1 OR expr2=x OR x=expr3

  139548. **     (C)     t1.x=t2.y OR (t1.x=t2.z AND t1.y=15)

  139549. **     (D)     x=expr1 OR (y>11 AND y<22 AND z LIKE '*hello*')

  139550. **     (E)     (p.a=1 AND q.b=2 AND r.c=3) OR (p.x=4 AND q.y=5 AND r.z=6)

  139551. **     (F)     x>A OR (x=A AND y>=B)

  139552. **

  139553. ** CASE 1:

  139554. **

  139555. ** If all subterms are of the form T.C=expr for some single column of C and

  139556. ** a single table T (as shown in example B above) then create a new virtual

  139557. ** term that is an equivalent IN expression.  In other words, if the term

  139558. ** being analyzed is:

  139559. **

  139560. **      x = expr1  OR  expr2 = x  OR  x = expr3

  139561. **

  139562. ** then create a new virtual term like this:

  139563. **

  139564. **      x IN (expr1,expr2,expr3)

  139565. **

  139566. ** CASE 2:

  139567. **

  139568. ** If there are exactly two disjuncts and one side has x>A and the other side

  139569. ** has x=A (for the same x and A) then add a new virtual conjunct term to the

  139570. ** WHERE clause of the form "x>=A".  Example:

  139571. **

  139572. **      x>A OR (x=A AND y>B)    adds:    x>=A

  139573. **

  139574. ** The added conjunct can sometimes be helpful in query planning.

  139575. **

  139576. ** CASE 3:

  139577. **

  139578. ** If all subterms are indexable by a single table T, then set

  139579. **

  139580. **     WhereTerm.eOperator              =  WO_OR

  139581. **     WhereTerm.u.pOrInfo->indexable  |=  the cursor number for table T

  139582. **

  139583. ** A subterm is "indexable" if it is of the form

  139584. ** "T.C <op> <expr>" where C is any column of table T and 

  139585. ** <op> is one of "=", "<", "<=", ">", ">=", "IS NULL", or "IN".

  139586. ** A subterm is also indexable if it is an AND of two or more

  139587. ** subsubterms at least one of which is indexable.  Indexable AND 

  139588. ** subterms have their eOperator set to WO_AND and they have

  139589. ** u.pAndInfo set to a dynamically allocated WhereAndTerm object.

  139590. **

  139591. ** From another point of view, "indexable" means that the subterm could

  139592. ** potentially be used with an index if an appropriate index exists.

  139593. ** This analysis does not consider whether or not the index exists; that

  139594. ** is decided elsewhere.  This analysis only looks at whether subterms

  139595. ** appropriate for indexing exist.

  139596. **

  139597. ** All examples A through E above satisfy case 3.  But if a term

  139598. ** also satisfies case 1 (such as B) we know that the optimizer will

  139599. ** always prefer case 1, so in that case we pretend that case 3 is not

  139600. ** satisfied.

  139601. **

  139602. ** It might be the case that multiple tables are indexable.  For example,

  139603. ** (E) above is indexable on tables P, Q, and R.

  139604. **

  139605. ** Terms that satisfy case 3 are candidates for lookup by using

  139606. ** separate indices to find rowids for each subterm and composing

  139607. ** the union of all rowids using a RowSet object.  This is similar

  139608. ** to "bitmap indices" in other database engines.

  139609. **

  139610. ** OTHERWISE:

  139611. **

  139612. ** If none of cases 1, 2, or 3 apply, then leave the eOperator set to

  139613. ** zero.  This term is not useful for search.

  139614. */

  139615. static void exprAnalyzeOrTerm(

  139616.   SrcList *pSrc,            /* the FROM clause */

  139617.   WhereClause *pWC,         /* the complete WHERE clause */

  139618.   int idxTerm               /* Index of the OR-term to be analyzed */

  139619. ){

  139620.   WhereInfo *pWInfo = pWC->pWInfo;        /* WHERE clause processing context */

  139621.   Parse *pParse = pWInfo->pParse;         /* Parser context */

  139622.   sqlite3 *db = pParse->db;               /* Database connection */

  139623.   WhereTerm *pTerm = &pWC->a[idxTerm];    /* The term to be analyzed */

  139624.   Expr *pExpr = pTerm->pExpr;             /* The expression of the term */

  139625.   int i;                                  /* Loop counters */

  139626.   WhereClause *pOrWc;       /* Breakup of pTerm into subterms */

  139627.   WhereTerm *pOrTerm;       /* A Sub-term within the pOrWc */

  139628.   WhereOrInfo *pOrInfo;     /* Additional information associated with pTerm */

  139629.   Bitmask chngToIN;         /* Tables that might satisfy case 1 */

  139630.   Bitmask indexable;        /* Tables that are indexable, satisfying case 2 */

  139631. 

  139632.   /*

  139633.   ** Break the OR clause into its separate subterms.  The subterms are

  139634.   ** stored in a WhereClause structure containing within the WhereOrInfo

  139635.   ** object that is attached to the original OR clause term.

  139636.   */

  139637.   assert( (pTerm->wtFlags & (TERM_DYNAMIC|TERM_ORINFO|TERM_ANDINFO))==0 );

  139638.   assert( pExpr->op==TK_OR );

  139639.   pTerm->u.pOrInfo = pOrInfo = sqlite3DbMallocZero(db, sizeof(*pOrInfo));

  139640.   if( pOrInfo==0 ) return;

  139641.   pTerm->wtFlags |= TERM_ORINFO;

  139642.   pOrWc = &pOrInfo->wc;

  139643.   memset(pOrWc->aStatic, 0, sizeof(pOrWc->aStatic));

  139644.   sqlite3WhereClauseInit(pOrWc, pWInfo);

  139645.   sqlite3WhereSplit(pOrWc, pExpr, TK_OR);

  139646.   sqlite3WhereExprAnalyze(pSrc, pOrWc);

  139647.   if( db->mallocFailed ) return;

  139648.   assert( pOrWc->nTerm>=2 );

  139649. 

  139650.   /*

  139651.   ** Compute the set of tables that might satisfy cases 1 or 3.

  139652.   */

  139653.   indexable = ~(Bitmask)0;

  139654.   chngToIN = ~(Bitmask)0;

  139655.   for(i=pOrWc->nTerm-1, pOrTerm=pOrWc->a; i>=0 && indexable; i--, pOrTerm++){

  139656.     if( (pOrTerm->eOperator & WO_SINGLE)==0 ){

  139657.       WhereAndInfo *pAndInfo;

  139658.       assert( (pOrTerm->wtFlags & (TERM_ANDINFO|TERM_ORINFO))==0 );

  139659.       chngToIN = 0;

  139660.       pAndInfo = sqlite3DbMallocRawNN(db, sizeof(*pAndInfo));

  139661.       if( pAndInfo ){

  139662.         WhereClause *pAndWC;

  139663.         WhereTerm *pAndTerm;

  139664.         int j;

  139665.         Bitmask b = 0;

  139666.         pOrTerm->u.pAndInfo = pAndInfo;

  139667.         pOrTerm->wtFlags |= TERM_ANDINFO;

  139668.         pOrTerm->eOperator = WO_AND;

  139669.         pAndWC = &pAndInfo->wc;

  139670.         memset(pAndWC->aStatic, 0, sizeof(pAndWC->aStatic));

  139671.         sqlite3WhereClauseInit(pAndWC, pWC->pWInfo);

  139672.         sqlite3WhereSplit(pAndWC, pOrTerm->pExpr, TK_AND);

  139673.         sqlite3WhereExprAnalyze(pSrc, pAndWC);

  139674.         pAndWC->pOuter = pWC;

  139675.         if( !db->mallocFailed ){

  139676.           for(j=0, pAndTerm=pAndWC->a; j<pAndWC->nTerm; j++, pAndTerm++){

  139677.             assert( pAndTerm->pExpr );

  139678.             if( allowedOp(pAndTerm->pExpr->op) 

  139679.              || pAndTerm->eOperator==WO_AUX

  139680.             ){

  139681.               b |= sqlite3WhereGetMask(&pWInfo->sMaskSet, pAndTerm->leftCursor);

  139682.             }

  139683.           }

  139684.         }

  139685.         indexable &= b;

  139686.       }

  139687.     }else if( pOrTerm->wtFlags & TERM_COPIED ){

  139688.       /* Skip this term for now.  We revisit it when we process the

  139689.       ** corresponding TERM_VIRTUAL term */

  139690.     }else{

  139691.       Bitmask b;

  139692.       b = sqlite3WhereGetMask(&pWInfo->sMaskSet, pOrTerm->leftCursor);

  139693.       if( pOrTerm->wtFlags & TERM_VIRTUAL ){

  139694.         WhereTerm *pOther = &pOrWc->a[pOrTerm->iParent];

  139695.         b |= sqlite3WhereGetMask(&pWInfo->sMaskSet, pOther->leftCursor);

  139696.       }

  139697.       indexable &= b;

  139698.       if( (pOrTerm->eOperator & WO_EQ)==0 ){

  139699.         chngToIN = 0;

  139700.       }else{

  139701.         chngToIN &= b;

  139702.       }

  139703.     }

  139704.   }

  139705. 

  139706.   /*

  139707.   ** Record the set of tables that satisfy case 3.  The set might be

  139708.   ** empty.

  139709.   */

  139710.   pOrInfo->indexable = indexable;

  139711.   if( indexable ){

  139712.     pTerm->eOperator = WO_OR;

  139713.     pWC->hasOr = 1;

  139714.   }else{

  139715.     pTerm->eOperator = WO_OR;

  139716.   }

  139717. 

  139718.   /* For a two-way OR, attempt to implementation case 2.

  139719.   */

  139720.   if( indexable && pOrWc->nTerm==2 ){

  139721.     int iOne = 0;

  139722.     WhereTerm *pOne;

  139723.     while( (pOne = whereNthSubterm(&pOrWc->a[0],iOne++))!=0 ){

  139724.       int iTwo = 0;

  139725.       WhereTerm *pTwo;

  139726.       while( (pTwo = whereNthSubterm(&pOrWc->a[1],iTwo++))!=0 ){

  139727.         whereCombineDisjuncts(pSrc, pWC, pOne, pTwo);

  139728.       }

  139729.     }

  139730.   }

  139731. 

  139732.   /*

  139733.   ** chngToIN holds a set of tables that *might* satisfy case 1.  But

  139734.   ** we have to do some additional checking to see if case 1 really

  139735.   ** is satisfied.

  139736.   **

  139737.   ** chngToIN will hold either 0, 1, or 2 bits.  The 0-bit case means

  139738.   ** that there is no possibility of transforming the OR clause into an

  139739.   ** IN operator because one or more terms in the OR clause contain

  139740.   ** something other than == on a column in the single table.  The 1-bit

  139741.   ** case means that every term of the OR clause is of the form

  139742.   ** "table.column=expr" for some single table.  The one bit that is set

  139743.   ** will correspond to the common table.  We still need to check to make

  139744.   ** sure the same column is used on all terms.  The 2-bit case is when

  139745.   ** the all terms are of the form "table1.column=table2.column".  It

  139746.   ** might be possible to form an IN operator with either table1.column

  139747.   ** or table2.column as the LHS if either is common to every term of

  139748.   ** the OR clause.

  139749.   **

  139750.   ** Note that terms of the form "table.column1=table.column2" (the

  139751.   ** same table on both sizes of the ==) cannot be optimized.

  139752.   */

  139753.   if( chngToIN ){

  139754.     int okToChngToIN = 0;     /* True if the conversion to IN is valid */

  139755.     int iColumn = -1;         /* Column index on lhs of IN operator */

  139756.     int iCursor = -1;         /* Table cursor common to all terms */

  139757.     int j = 0;                /* Loop counter */

  139758. 

  139759.     /* Search for a table and column that appears on one side or the

  139760.     ** other of the == operator in every subterm.  That table and column

  139761.     ** will be recorded in iCursor and iColumn.  There might not be any

  139762.     ** such table and column.  Set okToChngToIN if an appropriate table

  139763.     ** and column is found but leave okToChngToIN false if not found.

  139764.     */

  139765.     for(j=0; j<2 && !okToChngToIN; j++){

  139766.       Expr *pLeft = 0;

  139767.       pOrTerm = pOrWc->a;

  139768.       for(i=pOrWc->nTerm-1; i>=0; i--, pOrTerm++){

  139769.         assert( pOrTerm->eOperator & WO_EQ );

  139770.         pOrTerm->wtFlags &= ~TERM_OR_OK;

  139771.         if( pOrTerm->leftCursor==iCursor ){

  139772.           /* This is the 2-bit case and we are on the second iteration and

  139773.           ** current term is from the first iteration.  So skip this term. */

  139774.           assert( j==1 );

  139775.           continue;

  139776.         }

  139777.         if( (chngToIN & sqlite3WhereGetMask(&pWInfo->sMaskSet,

  139778.                                             pOrTerm->leftCursor))==0 ){

  139779.           /* This term must be of the form t1.a==t2.b where t2 is in the

  139780.           ** chngToIN set but t1 is not.  This term will be either preceded

  139781.           ** or follwed by an inverted copy (t2.b==t1.a).  Skip this term 

  139782.           ** and use its inversion. */

  139783.           testcase( pOrTerm->wtFlags & TERM_COPIED );

  139784.           testcase( pOrTerm->wtFlags & TERM_VIRTUAL );

  139785.           assert( pOrTerm->wtFlags & (TERM_COPIED|TERM_VIRTUAL) );

  139786.           continue;

  139787.         }

  139788.         iColumn = pOrTerm->u.leftColumn;

  139789.         iCursor = pOrTerm->leftCursor;

  139790.         pLeft = pOrTerm->pExpr->pLeft;

  139791.         break;

  139792.       }

  139793.       if( i<0 ){

  139794.         /* No candidate table+column was found.  This can only occur

  139795.         ** on the second iteration */

  139796.         assert( j==1 );

  139797.         assert( IsPowerOfTwo(chngToIN) );

  139798.         assert( chngToIN==sqlite3WhereGetMask(&pWInfo->sMaskSet, iCursor) );

  139799.         break;

  139800.       }

  139801.       testcase( j==1 );

  139802. 

  139803.       /* We have found a candidate table and column.  Check to see if that

  139804.       ** table and column is common to every term in the OR clause */

  139805.       okToChngToIN = 1;

  139806.       for(; i>=0 && okToChngToIN; i--, pOrTerm++){

  139807.         assert( pOrTerm->eOperator & WO_EQ );

  139808.         if( pOrTerm->leftCursor!=iCursor ){

  139809.           pOrTerm->wtFlags &= ~TERM_OR_OK;

  139810.         }else if( pOrTerm->u.leftColumn!=iColumn || (iColumn==XN_EXPR 

  139811.                && sqlite3ExprCompare(pParse, pOrTerm->pExpr->pLeft, pLeft, -1)

  139812.         )){

  139813.           okToChngToIN = 0;

  139814.         }else{

  139815.           int affLeft, affRight;

  139816.           /* If the right-hand side is also a column, then the affinities

  139817.           ** of both right and left sides must be such that no type

  139818.           ** conversions are required on the right.  (Ticket #2249)

  139819.           */

  139820.           affRight = sqlite3ExprAffinity(pOrTerm->pExpr->pRight);

  139821.           affLeft = sqlite3ExprAffinity(pOrTerm->pExpr->pLeft);

  139822.           if( affRight!=0 && affRight!=affLeft ){

  139823.             okToChngToIN = 0;

  139824.           }else{

  139825.             pOrTerm->wtFlags |= TERM_OR_OK;

  139826.           }

  139827.         }

  139828.       }

  139829.     }

  139830. 

  139831.     /* At this point, okToChngToIN is true if original pTerm satisfies

  139832.     ** case 1.  In that case, construct a new virtual term that is 

  139833.     ** pTerm converted into an IN operator.

  139834.     */

  139835.     if( okToChngToIN ){

  139836.       Expr *pDup;            /* A transient duplicate expression */

  139837.       ExprList *pList = 0;   /* The RHS of the IN operator */

  139838.       Expr *pLeft = 0;       /* The LHS of the IN operator */

  139839.       Expr *pNew;            /* The complete IN operator */

  139840. 

  139841.       for(i=pOrWc->nTerm-1, pOrTerm=pOrWc->a; i>=0; i--, pOrTerm++){

  139842.         if( (pOrTerm->wtFlags & TERM_OR_OK)==0 ) continue;

  139843.         assert( pOrTerm->eOperator & WO_EQ );

  139844.         assert( pOrTerm->leftCursor==iCursor );

  139845.         assert( pOrTerm->u.leftColumn==iColumn );

  139846.         pDup = sqlite3ExprDup(db, pOrTerm->pExpr->pRight, 0);

  139847.         pList = sqlite3ExprListAppend(pWInfo->pParse, pList, pDup);

  139848.         pLeft = pOrTerm->pExpr->pLeft;

  139849.       }

  139850.       assert( pLeft!=0 );

  139851.       pDup = sqlite3ExprDup(db, pLeft, 0);

  139852.       pNew = sqlite3PExpr(pParse, TK_IN, pDup, 0);

  139853.       if( pNew ){

  139854.         int idxNew;

  139855.         transferJoinMarkings(pNew, pExpr);

  139856.         assert( !ExprHasProperty(pNew, EP_xIsSelect) );

  139857.         pNew->x.pList = pList;

  139858.         idxNew = whereClauseInsert(pWC, pNew, TERM_VIRTUAL|TERM_DYNAMIC);

  139859.         testcase( idxNew==0 );

  139860.         exprAnalyze(pSrc, pWC, idxNew);

  139861.         /* pTerm = &pWC->a[idxTerm]; // would be needed if pTerm where used again */

  139862.         markTermAsChild(pWC, idxNew, idxTerm);

  139863.       }else{

  139864.         sqlite3ExprListDelete(db, pList);

  139865.       }

  139866.     }

  139867.   }

  139868. }

  139869. #endif /* !SQLITE_OMIT_OR_OPTIMIZATION && !SQLITE_OMIT_SUBQUERY */

  139870. 

  139871. /*

  139872. ** We already know that pExpr is a binary operator where both operands are

  139873. ** column references.  This routine checks to see if pExpr is an equivalence

  139874. ** relation:

  139875. **   1.  The SQLITE_Transitive optimization must be enabled

  139876. **   2.  Must be either an == or an IS operator

  139877. **   3.  Not originating in the ON clause of an OUTER JOIN

  139878. **   4.  The affinities of A and B must be compatible

  139879. **   5a. Both operands use the same collating sequence OR

  139880. **   5b. The overall collating sequence is BINARY

  139881. ** If this routine returns TRUE, that means that the RHS can be substituted

  139882. ** for the LHS anyplace else in the WHERE clause where the LHS column occurs.

  139883. ** This is an optimization.  No harm comes from returning 0.  But if 1 is

  139884. ** returned when it should not be, then incorrect answers might result.

  139885. */

  139886. static int termIsEquivalence(Parse *pParse, Expr *pExpr){

  139887.   char aff1, aff2;

  139888.   CollSeq *pColl;

  139889.   if( !OptimizationEnabled(pParse->db, SQLITE_Transitive) ) return 0;

  139890.   if( pExpr->op!=TK_EQ && pExpr->op!=TK_IS ) return 0;

  139891.   if( ExprHasProperty(pExpr, EP_FromJoin) ) return 0;

  139892.   aff1 = sqlite3ExprAffinity(pExpr->pLeft);

  139893.   aff2 = sqlite3ExprAffinity(pExpr->pRight);

  139894.   if( aff1!=aff2

  139895.    && (!sqlite3IsNumericAffinity(aff1) || !sqlite3IsNumericAffinity(aff2))

  139896.   ){

  139897.     return 0;

  139898.   }

  139899.   pColl = sqlite3BinaryCompareCollSeq(pParse, pExpr->pLeft, pExpr->pRight);

  139900.   if( sqlite3IsBinary(pColl) ) return 1;

  139901.   return sqlite3ExprCollSeqMatch(pParse, pExpr->pLeft, pExpr->pRight);

  139902. }

  139903. 

  139904. /*

  139905. ** Recursively walk the expressions of a SELECT statement and generate

  139906. ** a bitmask indicating which tables are used in that expression

  139907. ** tree.

  139908. */

  139909. static Bitmask exprSelectUsage(WhereMaskSet *pMaskSet, Select *pS){

  139910.   Bitmask mask = 0;

  139911.   while( pS ){

  139912.     SrcList *pSrc = pS->pSrc;

  139913.     mask |= sqlite3WhereExprListUsage(pMaskSet, pS->pEList);

  139914.     mask |= sqlite3WhereExprListUsage(pMaskSet, pS->pGroupBy);

  139915.     mask |= sqlite3WhereExprListUsage(pMaskSet, pS->pOrderBy);

  139916.     mask |= sqlite3WhereExprUsage(pMaskSet, pS->pWhere);

  139917.     mask |= sqlite3WhereExprUsage(pMaskSet, pS->pHaving);

  139918.     if( ALWAYS(pSrc!=0) ){

  139919.       int i;

  139920.       for(i=0; i<pSrc->nSrc; i++){

  139921.         mask |= exprSelectUsage(pMaskSet, pSrc->a[i].pSelect);

  139922.         mask |= sqlite3WhereExprUsage(pMaskSet, pSrc->a[i].pOn);

  139923.         if( pSrc->a[i].fg.isTabFunc ){

  139924.           mask |= sqlite3WhereExprListUsage(pMaskSet, pSrc->a[i].u1.pFuncArg);

  139925.         }

  139926.       }

  139927.     }

  139928.     pS = pS->pPrior;

  139929.   }

  139930.   return mask;

  139931. }

  139932. 

  139933. /*

  139934. ** Expression pExpr is one operand of a comparison operator that might

  139935. ** be useful for indexing.  This routine checks to see if pExpr appears

  139936. ** in any index.  Return TRUE (1) if pExpr is an indexed term and return

  139937. ** FALSE (0) if not.  If TRUE is returned, also set aiCurCol[0] to the cursor

  139938. ** number of the table that is indexed and aiCurCol[1] to the column number

  139939. ** of the column that is indexed, or XN_EXPR (-2) if an expression is being

  139940. ** indexed.

  139941. **

  139942. ** If pExpr is a TK_COLUMN column reference, then this routine always returns

  139943. ** true even if that particular column is not indexed, because the column

  139944. ** might be added to an automatic index later.

  139945. */

  139946. static SQLITE_NOINLINE int exprMightBeIndexed2(

  139947.   SrcList *pFrom,        /* The FROM clause */

  139948.   Bitmask mPrereq,       /* Bitmask of FROM clause terms referenced by pExpr */

  139949.   int *aiCurCol,         /* Write the referenced table cursor and column here */

  139950.   Expr *pExpr            /* An operand of a comparison operator */

  139951. ){

  139952.   Index *pIdx;

  139953.   int i;

  139954.   int iCur;

  139955.   for(i=0; mPrereq>1; i++, mPrereq>>=1){}

  139956.   iCur = pFrom->a[i].iCursor;

  139957.   for(pIdx=pFrom->a[i].pTab->pIndex; pIdx; pIdx=pIdx->pNext){

  139958.     if( pIdx->aColExpr==0 ) continue;

  139959.     for(i=0; i<pIdx->nKeyCol; i++){

  139960.       if( pIdx->aiColumn[i]!=XN_EXPR ) continue;

  139961.       if( sqlite3ExprCompareSkip(pExpr, pIdx->aColExpr->a[i].pExpr, iCur)==0 ){

  139962.         aiCurCol[0] = iCur;

  139963.         aiCurCol[1] = XN_EXPR;

  139964.         return 1;

  139965.       }

  139966.     }

  139967.   }

  139968.   return 0;

  139969. }

  139970. static int exprMightBeIndexed(

  139971.   SrcList *pFrom,        /* The FROM clause */

  139972.   Bitmask mPrereq,       /* Bitmask of FROM clause terms referenced by pExpr */

  139973.   int *aiCurCol,         /* Write the referenced table cursor & column here */

  139974.   Expr *pExpr,           /* An operand of a comparison operator */

  139975.   int op                 /* The specific comparison operator */

  139976. ){

  139977.   /* If this expression is a vector to the left or right of a 

  139978.   ** inequality constraint (>, <, >= or <=), perform the processing 

  139979.   ** on the first element of the vector.  */

  139980.   assert( TK_GT+1==TK_LE && TK_GT+2==TK_LT && TK_GT+3==TK_GE );

  139981.   assert( TK_IS<TK_GE && TK_ISNULL<TK_GE && TK_IN<TK_GE );

  139982.   assert( op<=TK_GE );

  139983.   if( pExpr->op==TK_VECTOR && (op>=TK_GT && ALWAYS(op<=TK_GE)) ){

  139984.     pExpr = pExpr->x.pList->a[0].pExpr;

  139985.   }

  139986. 

  139987.   if( pExpr->op==TK_COLUMN ){

  139988.     aiCurCol[0] = pExpr->iTable;

  139989.     aiCurCol[1] = pExpr->iColumn;

  139990.     return 1;

  139991.   }

  139992.   if( mPrereq==0 ) return 0;                 /* No table references */

  139993.   if( (mPrereq&(mPrereq-1))!=0 ) return 0;   /* Refs more than one table */

  139994.   return exprMightBeIndexed2(pFrom,mPrereq,aiCurCol,pExpr);

  139995. }

  139996. 

  139997. /*

  139998. ** The input to this routine is an WhereTerm structure with only the

  139999. ** "pExpr" field filled in.  The job of this routine is to analyze the

  140000. ** subexpression and populate all the other fields of the WhereTerm

  140001. ** structure.

  140002. **

  140003. ** If the expression is of the form "<expr> <op> X" it gets commuted

  140004. ** to the standard form of "X <op> <expr>".

  140005. **

  140006. ** If the expression is of the form "X <op> Y" where both X and Y are

  140007. ** columns, then the original expression is unchanged and a new virtual

  140008. ** term of the form "Y <op> X" is added to the WHERE clause and

  140009. ** analyzed separately.  The original term is marked with TERM_COPIED

  140010. ** and the new term is marked with TERM_DYNAMIC (because it's pExpr

  140011. ** needs to be freed with the WhereClause) and TERM_VIRTUAL (because it

  140012. ** is a commuted copy of a prior term.)  The original term has nChild=1

  140013. ** and the copy has idxParent set to the index of the original term.

  140014. */

  140015. static void exprAnalyze(

  140016.   SrcList *pSrc,            /* the FROM clause */

  140017.   WhereClause *pWC,         /* the WHERE clause */

  140018.   int idxTerm               /* Index of the term to be analyzed */

  140019. ){

  140020.   WhereInfo *pWInfo = pWC->pWInfo; /* WHERE clause processing context */

  140021.   WhereTerm *pTerm;                /* The term to be analyzed */

  140022.   WhereMaskSet *pMaskSet;          /* Set of table index masks */

  140023.   Expr *pExpr;                     /* The expression to be analyzed */

  140024.   Bitmask prereqLeft;              /* Prerequesites of the pExpr->pLeft */

  140025.   Bitmask prereqAll;               /* Prerequesites of pExpr */

  140026.   Bitmask extraRight = 0;          /* Extra dependencies on LEFT JOIN */

  140027.   Expr *pStr1 = 0;                 /* RHS of LIKE/GLOB operator */

  140028.   int isComplete = 0;              /* RHS of LIKE/GLOB ends with wildcard */

  140029.   int noCase = 0;                  /* uppercase equivalent to lowercase */

  140030.   int op;                          /* Top-level operator.  pExpr->op */

  140031.   Parse *pParse = pWInfo->pParse;  /* Parsing context */

  140032.   sqlite3 *db = pParse->db;        /* Database connection */

  140033.   unsigned char eOp2 = 0;          /* op2 value for LIKE/REGEXP/GLOB */

  140034.   int nLeft;                       /* Number of elements on left side vector */

  140035. 

  140036.   if( db->mallocFailed ){

  140037.     return;

  140038.   }

  140039.   pTerm = &pWC->a[idxTerm];

  140040.   pMaskSet = &pWInfo->sMaskSet;

  140041.   pExpr = pTerm->pExpr;

  140042.   assert( pExpr->op!=TK_AS && pExpr->op!=TK_COLLATE );

  140043.   prereqLeft = sqlite3WhereExprUsage(pMaskSet, pExpr->pLeft);

  140044.   op = pExpr->op;

  140045.   if( op==TK_IN ){

  140046.     assert( pExpr->pRight==0 );

  140047.     if( sqlite3ExprCheckIN(pParse, pExpr) ) return;

  140048.     if( ExprHasProperty(pExpr, EP_xIsSelect) ){

  140049.       pTerm->prereqRight = exprSelectUsage(pMaskSet, pExpr->x.pSelect);

  140050.     }else{

  140051.       pTerm->prereqRight = sqlite3WhereExprListUsage(pMaskSet, pExpr->x.pList);

  140052.     }

  140053.   }else if( op==TK_ISNULL ){

  140054.     pTerm->prereqRight = 0;

  140055.   }else{

  140056.     pTerm->prereqRight = sqlite3WhereExprUsage(pMaskSet, pExpr->pRight);

  140057.   }

  140058.   pMaskSet->bVarSelect = 0;

  140059.   prereqAll = sqlite3WhereExprUsageNN(pMaskSet, pExpr);

  140060.   if( pMaskSet->bVarSelect ) pTerm->wtFlags |= TERM_VARSELECT;

  140061.   if( ExprHasProperty(pExpr, EP_FromJoin) ){

  140062.     Bitmask x = sqlite3WhereGetMask(pMaskSet, pExpr->iRightJoinTable);

  140063.     prereqAll |= x;

  140064.     extraRight = x-1;  /* ON clause terms may not be used with an index

  140065.                        ** on left table of a LEFT JOIN.  Ticket #3015 */

  140066.     if( (prereqAll>>1)>=x ){

  140067.       sqlite3ErrorMsg(pParse, "ON clause references tables to its right");

  140068.       return;

  140069.     }

  140070.   }

  140071.   pTerm->prereqAll = prereqAll;

  140072.   pTerm->leftCursor = -1;

  140073.   pTerm->iParent = -1;

  140074.   pTerm->eOperator = 0;

  140075.   if( allowedOp(op) ){

  140076.     int aiCurCol[2];

  140077.     Expr *pLeft = sqlite3ExprSkipCollate(pExpr->pLeft);

  140078.     Expr *pRight = sqlite3ExprSkipCollate(pExpr->pRight);

  140079.     u16 opMask = (pTerm->prereqRight & prereqLeft)==0 ? WO_ALL : WO_EQUIV;

  140080. 

  140081.     if( pTerm->iField>0 ){

  140082.       assert( op==TK_IN );

  140083.       assert( pLeft->op==TK_VECTOR );

  140084.       pLeft = pLeft->x.pList->a[pTerm->iField-1].pExpr;

  140085.     }

  140086. 

  140087.     if( exprMightBeIndexed(pSrc, prereqLeft, aiCurCol, pLeft, op) ){

  140088.       pTerm->leftCursor = aiCurCol[0];

  140089.       pTerm->u.leftColumn = aiCurCol[1];

  140090.       pTerm->eOperator = operatorMask(op) & opMask;

  140091.     }

  140092.     if( op==TK_IS ) pTerm->wtFlags |= TERM_IS;

  140093.     if( pRight 

  140094.      && exprMightBeIndexed(pSrc, pTerm->prereqRight, aiCurCol, pRight, op)

  140095.     ){

  140096.       WhereTerm *pNew;

  140097.       Expr *pDup;

  140098.       u16 eExtraOp = 0;        /* Extra bits for pNew->eOperator */

  140099.       assert( pTerm->iField==0 );

  140100.       if( pTerm->leftCursor>=0 ){

  140101.         int idxNew;

  140102.         pDup = sqlite3ExprDup(db, pExpr, 0);

  140103.         if( db->mallocFailed ){

  140104.           sqlite3ExprDelete(db, pDup);

  140105.           return;

  140106.         }

  140107.         idxNew = whereClauseInsert(pWC, pDup, TERM_VIRTUAL|TERM_DYNAMIC);

  140108.         if( idxNew==0 ) return;

  140109.         pNew = &pWC->a[idxNew];

  140110.         markTermAsChild(pWC, idxNew, idxTerm);

  140111.         if( op==TK_IS ) pNew->wtFlags |= TERM_IS;

  140112.         pTerm = &pWC->a[idxTerm];

  140113.         pTerm->wtFlags |= TERM_COPIED;

  140114. 

  140115.         if( termIsEquivalence(pParse, pDup) ){

  140116.           pTerm->eOperator |= WO_EQUIV;

  140117.           eExtraOp = WO_EQUIV;

  140118.         }

  140119.       }else{

  140120.         pDup = pExpr;

  140121.         pNew = pTerm;

  140122.       }

  140123.       exprCommute(pParse, pDup);

  140124.       pNew->leftCursor = aiCurCol[0];

  140125.       pNew->u.leftColumn = aiCurCol[1];

  140126.       testcase( (prereqLeft | extraRight) != prereqLeft );

  140127.       pNew->prereqRight = prereqLeft | extraRight;

  140128.       pNew->prereqAll = prereqAll;

  140129.       pNew->eOperator = (operatorMask(pDup->op) + eExtraOp) & opMask;

  140130.     }

  140131.   }

  140132. 

  140133. #ifndef SQLITE_OMIT_BETWEEN_OPTIMIZATION

  140134.   /* If a term is the BETWEEN operator, create two new virtual terms

  140135.   ** that define the range that the BETWEEN implements.  For example:

  140136.   **

  140137.   **      a BETWEEN b AND c

  140138.   **

  140139.   ** is converted into:

  140140.   **

  140141.   **      (a BETWEEN b AND c) AND (a>=b) AND (a<=c)

  140142.   **

  140143.   ** The two new terms are added onto the end of the WhereClause object.

  140144.   ** The new terms are "dynamic" and are children of the original BETWEEN

  140145.   ** term.  That means that if the BETWEEN term is coded, the children are

  140146.   ** skipped.  Or, if the children are satisfied by an index, the original

  140147.   ** BETWEEN term is skipped.

  140148.   */

  140149.   else if( pExpr->op==TK_BETWEEN && pWC->op==TK_AND ){

  140150.     ExprList *pList = pExpr->x.pList;

  140151.     int i;

  140152.     static const u8 ops[] = {TK_GE, TK_LE};

  140153.     assert( pList!=0 );

  140154.     assert( pList->nExpr==2 );

  140155.     for(i=0; i<2; i++){

  140156.       Expr *pNewExpr;

  140157.       int idxNew;

  140158.       pNewExpr = sqlite3PExpr(pParse, ops[i], 

  140159.                              sqlite3ExprDup(db, pExpr->pLeft, 0),

  140160.                              sqlite3ExprDup(db, pList->a[i].pExpr, 0));

  140161.       transferJoinMarkings(pNewExpr, pExpr);

  140162.       idxNew = whereClauseInsert(pWC, pNewExpr, TERM_VIRTUAL|TERM_DYNAMIC);

  140163.       testcase( idxNew==0 );

  140164.       exprAnalyze(pSrc, pWC, idxNew);

  140165.       pTerm = &pWC->a[idxTerm];

  140166.       markTermAsChild(pWC, idxNew, idxTerm);

  140167.     }

  140168.   }

  140169. #endif /* SQLITE_OMIT_BETWEEN_OPTIMIZATION */

  140170. 

  140171. #if !defined(SQLITE_OMIT_OR_OPTIMIZATION) && !defined(SQLITE_OMIT_SUBQUERY)

  140172.   /* Analyze a term that is composed of two or more subterms connected by

  140173.   ** an OR operator.

  140174.   */

  140175.   else if( pExpr->op==TK_OR ){

  140176.     assert( pWC->op==TK_AND );

  140177.     exprAnalyzeOrTerm(pSrc, pWC, idxTerm);

  140178.     pTerm = &pWC->a[idxTerm];

  140179.   }

  140180. #endif /* SQLITE_OMIT_OR_OPTIMIZATION */

  140181. 

  140182. #ifndef SQLITE_OMIT_LIKE_OPTIMIZATION

  140183.   /* Add constraints to reduce the search space on a LIKE or GLOB

  140184.   ** operator.

  140185.   **

  140186.   ** A like pattern of the form "x LIKE 'aBc%'" is changed into constraints

  140187.   **

  140188.   **          x>='ABC' AND x<'abd' AND x LIKE 'aBc%'

  140189.   **

  140190.   ** The last character of the prefix "abc" is incremented to form the

  140191.   ** termination condition "abd".  If case is not significant (the default

  140192.   ** for LIKE) then the lower-bound is made all uppercase and the upper-

  140193.   ** bound is made all lowercase so that the bounds also work when comparing

  140194.   ** BLOBs.

  140195.   */

  140196.   if( pWC->op==TK_AND 

  140197.    && isLikeOrGlob(pParse, pExpr, &pStr1, &isComplete, &noCase)

  140198.   ){

  140199.     Expr *pLeft;       /* LHS of LIKE/GLOB operator */

  140200.     Expr *pStr2;       /* Copy of pStr1 - RHS of LIKE/GLOB operator */

  140201.     Expr *pNewExpr1;

  140202.     Expr *pNewExpr2;

  140203.     int idxNew1;

  140204.     int idxNew2;

  140205.     const char *zCollSeqName;     /* Name of collating sequence */

  140206.     const u16 wtFlags = TERM_LIKEOPT | TERM_VIRTUAL | TERM_DYNAMIC;

  140207. 

  140208.     pLeft = pExpr->x.pList->a[1].pExpr;

  140209.     pStr2 = sqlite3ExprDup(db, pStr1, 0);

  140210. 

  140211.     /* Convert the lower bound to upper-case and the upper bound to

  140212.     ** lower-case (upper-case is less than lower-case in ASCII) so that

  140213.     ** the range constraints also work for BLOBs

  140214.     */

  140215.     if( noCase && !pParse->db->mallocFailed ){

  140216.       int i;

  140217.       char c;

  140218.       pTerm->wtFlags |= TERM_LIKE;

  140219.       for(i=0; (c = pStr1->u.zToken[i])!=0; i++){

  140220.         pStr1->u.zToken[i] = sqlite3Toupper(c);

  140221.         pStr2->u.zToken[i] = sqlite3Tolower(c);

  140222.       }

  140223.     }

  140224. 

  140225.     if( !db->mallocFailed ){

  140226.       u8 c, *pC;       /* Last character before the first wildcard */

  140227.       pC = (u8*)&pStr2->u.zToken[sqlite3Strlen30(pStr2->u.zToken)-1];

  140228.       c = *pC;

  140229.       if( noCase ){

  140230.         /* The point is to increment the last character before the first

  140231.         ** wildcard.  But if we increment '@', that will push it into the

  140232.         ** alphabetic range where case conversions will mess up the 

  140233.         ** inequality.  To avoid this, make sure to also run the full

  140234.         ** LIKE on all candidate expressions by clearing the isComplete flag

  140235.         */

  140236.         if( c=='A'-1 ) isComplete = 0;

  140237.         c = sqlite3UpperToLower[c];

  140238.       }

  140239.       *pC = c + 1;

  140240.     }

  140241.     zCollSeqName = noCase ? "NOCASE" : sqlite3StrBINARY;

  140242.     pNewExpr1 = sqlite3ExprDup(db, pLeft, 0);

  140243.     pNewExpr1 = sqlite3PExpr(pParse, TK_GE,

  140244.            sqlite3ExprAddCollateString(pParse,pNewExpr1,zCollSeqName),

  140245.            pStr1);

  140246.     transferJoinMarkings(pNewExpr1, pExpr);

  140247.     idxNew1 = whereClauseInsert(pWC, pNewExpr1, wtFlags);

  140248.     testcase( idxNew1==0 );

  140249.     exprAnalyze(pSrc, pWC, idxNew1);

  140250.     pNewExpr2 = sqlite3ExprDup(db, pLeft, 0);

  140251.     pNewExpr2 = sqlite3PExpr(pParse, TK_LT,

  140252.            sqlite3ExprAddCollateString(pParse,pNewExpr2,zCollSeqName),

  140253.            pStr2);

  140254.     transferJoinMarkings(pNewExpr2, pExpr);

  140255.     idxNew2 = whereClauseInsert(pWC, pNewExpr2, wtFlags);

  140256.     testcase( idxNew2==0 );

  140257.     exprAnalyze(pSrc, pWC, idxNew2);

  140258.     pTerm = &pWC->a[idxTerm];

  140259.     if( isComplete ){

  140260.       markTermAsChild(pWC, idxNew1, idxTerm);

  140261.       markTermAsChild(pWC, idxNew2, idxTerm);

  140262.     }

  140263.   }

  140264. #endif /* SQLITE_OMIT_LIKE_OPTIMIZATION */

  140265. 

  140266. #ifndef SQLITE_OMIT_VIRTUALTABLE

  140267.   /* Add a WO_AUX auxiliary term to the constraint set if the

  140268.   ** current expression is of the form "column OP expr" where OP

  140269.   ** is an operator that gets passed into virtual tables but which is

  140270.   ** not normally optimized for ordinary tables.  In other words, OP

  140271.   ** is one of MATCH, LIKE, GLOB, REGEXP, !=, IS, IS NOT, or NOT NULL.

  140272.   ** This information is used by the xBestIndex methods of

  140273.   ** virtual tables.  The native query optimizer does not attempt

  140274.   ** to do anything with MATCH functions.

  140275.   */

  140276.   if( pWC->op==TK_AND ){

  140277.     Expr *pRight = 0, *pLeft = 0;

  140278.     int res = isAuxiliaryVtabOperator(db, pExpr, &eOp2, &pLeft, &pRight);

  140279.     while( res-- > 0 ){

  140280.       int idxNew;

  140281.       WhereTerm *pNewTerm;

  140282.       Bitmask prereqColumn, prereqExpr;

  140283. 

  140284.       prereqExpr = sqlite3WhereExprUsage(pMaskSet, pRight);

  140285.       prereqColumn = sqlite3WhereExprUsage(pMaskSet, pLeft);

  140286.       if( (prereqExpr & prereqColumn)==0 ){

  140287.         Expr *pNewExpr;

  140288.         pNewExpr = sqlite3PExpr(pParse, TK_MATCH, 

  140289.             0, sqlite3ExprDup(db, pRight, 0));

  140290.         if( ExprHasProperty(pExpr, EP_FromJoin) && pNewExpr ){

  140291.           ExprSetProperty(pNewExpr, EP_FromJoin);

  140292.         }

  140293.         idxNew = whereClauseInsert(pWC, pNewExpr, TERM_VIRTUAL|TERM_DYNAMIC);

  140294.         testcase( idxNew==0 );

  140295.         pNewTerm = &pWC->a[idxNew];

  140296.         pNewTerm->prereqRight = prereqExpr;

  140297.         pNewTerm->leftCursor = pLeft->iTable;

  140298.         pNewTerm->u.leftColumn = pLeft->iColumn;

  140299.         pNewTerm->eOperator = WO_AUX;

  140300.         pNewTerm->eMatchOp = eOp2;

  140301.         markTermAsChild(pWC, idxNew, idxTerm);

  140302.         pTerm = &pWC->a[idxTerm];

  140303.         pTerm->wtFlags |= TERM_COPIED;

  140304.         pNewTerm->prereqAll = pTerm->prereqAll;

  140305.       }

  140306.       SWAP(Expr*, pLeft, pRight);

  140307.     }

  140308.   }

  140309. #endif /* SQLITE_OMIT_VIRTUALTABLE */

  140310. 

  140311.   /* If there is a vector == or IS term - e.g. "(a, b) == (?, ?)" - create

  140312.   ** new terms for each component comparison - "a = ?" and "b = ?".  The

  140313.   ** new terms completely replace the original vector comparison, which is

  140314.   ** no longer used.

  140315.   **

  140316.   ** This is only required if at least one side of the comparison operation

  140317.   ** is not a sub-select.  */

  140318.   if( pWC->op==TK_AND 

  140319.   && (pExpr->op==TK_EQ || pExpr->op==TK_IS)

  140320.   && (nLeft = sqlite3ExprVectorSize(pExpr->pLeft))>1

  140321.   && sqlite3ExprVectorSize(pExpr->pRight)==nLeft

  140322.   && ( (pExpr->pLeft->flags & EP_xIsSelect)==0 

  140323.     || (pExpr->pRight->flags & EP_xIsSelect)==0)

  140324.   ){

  140325.     int i;

  140326.     for(i=0; i<nLeft; i++){

  140327.       int idxNew;

  140328.       Expr *pNew;

  140329.       Expr *pLeft = sqlite3ExprForVectorField(pParse, pExpr->pLeft, i);

  140330.       Expr *pRight = sqlite3ExprForVectorField(pParse, pExpr->pRight, i);

  140331. 

  140332.       pNew = sqlite3PExpr(pParse, pExpr->op, pLeft, pRight);

  140333.       transferJoinMarkings(pNew, pExpr);

  140334.       idxNew = whereClauseInsert(pWC, pNew, TERM_DYNAMIC);

  140335.       exprAnalyze(pSrc, pWC, idxNew);

  140336.     }

  140337.     pTerm = &pWC->a[idxTerm];

  140338.     pTerm->wtFlags |= TERM_CODED|TERM_VIRTUAL;  /* Disable the original */

  140339.     pTerm->eOperator = 0;

  140340.   }

  140341. 

  140342.   /* If there is a vector IN term - e.g. "(a, b) IN (SELECT ...)" - create

  140343.   ** a virtual term for each vector component. The expression object

  140344.   ** used by each such virtual term is pExpr (the full vector IN(...) 

  140345.   ** expression). The WhereTerm.iField variable identifies the index within

  140346.   ** the vector on the LHS that the virtual term represents.

  140347.   **

  140348.   ** This only works if the RHS is a simple SELECT, not a compound

  140349.   */

  140350.   if( pWC->op==TK_AND && pExpr->op==TK_IN && pTerm->iField==0

  140351.    && pExpr->pLeft->op==TK_VECTOR

  140352.    && pExpr->x.pSelect->pPrior==0

  140353.   ){

  140354.     int i;

  140355.     for(i=0; i<sqlite3ExprVectorSize(pExpr->pLeft); i++){

  140356.       int idxNew;

  140357.       idxNew = whereClauseInsert(pWC, pExpr, TERM_VIRTUAL);

  140358.       pWC->a[idxNew].iField = i+1;

  140359.       exprAnalyze(pSrc, pWC, idxNew);

  140360.       markTermAsChild(pWC, idxNew, idxTerm);

  140361.     }

  140362.   }

  140363. 

  140364. #ifdef SQLITE_ENABLE_STAT3_OR_STAT4

  140365.   /* When sqlite_stat3 histogram data is available an operator of the

  140366.   ** form "x IS NOT NULL" can sometimes be evaluated more efficiently

  140367.   ** as "x>NULL" if x is not an INTEGER PRIMARY KEY.  So construct a

  140368.   ** virtual term of that form.

  140369.   **

  140370.   ** Note that the virtual term must be tagged with TERM_VNULL.

  140371.   */

  140372.   if( pExpr->op==TK_NOTNULL

  140373.    && pExpr->pLeft->op==TK_COLUMN

  140374.    && pExpr->pLeft->iColumn>=0

  140375.    && !ExprHasProperty(pExpr, EP_FromJoin)

  140376.    && OptimizationEnabled(db, SQLITE_Stat34)

  140377.   ){

  140378.     Expr *pNewExpr;

  140379.     Expr *pLeft = pExpr->pLeft;

  140380.     int idxNew;

  140381.     WhereTerm *pNewTerm;

  140382. 

  140383.     pNewExpr = sqlite3PExpr(pParse, TK_GT,

  140384.                             sqlite3ExprDup(db, pLeft, 0),

  140385.                             sqlite3ExprAlloc(db, TK_NULL, 0, 0));

  140386. 

  140387.     idxNew = whereClauseInsert(pWC, pNewExpr,

  140388.                               TERM_VIRTUAL|TERM_DYNAMIC|TERM_VNULL);

  140389.     if( idxNew ){

  140390.       pNewTerm = &pWC->a[idxNew];

  140391.       pNewTerm->prereqRight = 0;

  140392.       pNewTerm->leftCursor = pLeft->iTable;

  140393.       pNewTerm->u.leftColumn = pLeft->iColumn;

  140394.       pNewTerm->eOperator = WO_GT;

  140395.       markTermAsChild(pWC, idxNew, idxTerm);

  140396.       pTerm = &pWC->a[idxTerm];

  140397.       pTerm->wtFlags |= TERM_COPIED;

  140398.       pNewTerm->prereqAll = pTerm->prereqAll;

  140399.     }

  140400.   }

  140401. #endif /* SQLITE_ENABLE_STAT3_OR_STAT4 */

  140402. 

  140403.   /* Prevent ON clause terms of a LEFT JOIN from being used to drive

  140404.   ** an index for tables to the left of the join.

  140405.   */

  140406.   testcase( pTerm!=&pWC->a[idxTerm] );

  140407.   pTerm = &pWC->a[idxTerm];

  140408.   pTerm->prereqRight |= extraRight;

  140409. }

  140410. 

  140411. /***************************************************************************

  140412. ** Routines with file scope above.  Interface to the rest of the where.c

  140413. ** subsystem follows.

  140414. ***************************************************************************/

  140415. 

  140416. /*

  140417. ** This routine identifies subexpressions in the WHERE clause where

  140418. ** each subexpression is separated by the AND operator or some other

  140419. ** operator specified in the op parameter.  The WhereClause structure

  140420. ** is filled with pointers to subexpressions.  For example:

  140421. **

  140422. **    WHERE  a=='hello' AND coalesce(b,11)<10 AND (c+12!=d OR c==22)

  140423. **           \________/     \_______________/     \________________/

  140424. **            slot[0]            slot[1]               slot[2]

  140425. **

  140426. ** The original WHERE clause in pExpr is unaltered.  All this routine

  140427. ** does is make slot[] entries point to substructure within pExpr.

  140428. **

  140429. ** In the previous sentence and in the diagram, "slot[]" refers to

  140430. ** the WhereClause.a[] array.  The slot[] array grows as needed to contain

  140431. ** all terms of the WHERE clause.

  140432. */

  140433. SQLITE_PRIVATE void sqlite3WhereSplit(WhereClause *pWC, Expr *pExpr, u8 op){

  140434.   Expr *pE2 = sqlite3ExprSkipCollate(pExpr);

  140435.   pWC->op = op;

  140436.   if( pE2==0 ) return;

  140437.   if( pE2->op!=op ){

  140438.     whereClauseInsert(pWC, pExpr, 0);

  140439.   }else{

  140440.     sqlite3WhereSplit(pWC, pE2->pLeft, op);

  140441.     sqlite3WhereSplit(pWC, pE2->pRight, op);

  140442.   }

  140443. }

  140444. 

  140445. /*

  140446. ** Initialize a preallocated WhereClause structure.

  140447. */

  140448. SQLITE_PRIVATE void sqlite3WhereClauseInit(

  140449.   WhereClause *pWC,        /* The WhereClause to be initialized */

  140450.   WhereInfo *pWInfo        /* The WHERE processing context */

  140451. ){

  140452.   pWC->pWInfo = pWInfo;

  140453.   pWC->hasOr = 0;

  140454.   pWC->pOuter = 0;

  140455.   pWC->nTerm = 0;

  140456.   pWC->nSlot = ArraySize(pWC->aStatic);

  140457.   pWC->a = pWC->aStatic;

  140458. }

  140459. 

  140460. /*

  140461. ** Deallocate a WhereClause structure.  The WhereClause structure

  140462. ** itself is not freed.  This routine is the inverse of

  140463. ** sqlite3WhereClauseInit().

  140464. */

  140465. SQLITE_PRIVATE void sqlite3WhereClauseClear(WhereClause *pWC){

  140466.   int i;

  140467.   WhereTerm *a;

  140468.   sqlite3 *db = pWC->pWInfo->pParse->db;

  140469.   for(i=pWC->nTerm-1, a=pWC->a; i>=0; i--, a++){

  140470.     if( a->wtFlags & TERM_DYNAMIC ){

  140471.       sqlite3ExprDelete(db, a->pExpr);

  140472.     }

  140473.     if( a->wtFlags & TERM_ORINFO ){

  140474.       whereOrInfoDelete(db, a->u.pOrInfo);

  140475.     }else if( a->wtFlags & TERM_ANDINFO ){

  140476.       whereAndInfoDelete(db, a->u.pAndInfo);

  140477.     }

  140478.   }

  140479.   if( pWC->a!=pWC->aStatic ){

  140480.     sqlite3DbFree(db, pWC->a);

  140481.   }

  140482. }

  140483. 

  140484. 

  140485. /*

  140486. ** These routines walk (recursively) an expression tree and generate

  140487. ** a bitmask indicating which tables are used in that expression

  140488. ** tree.

  140489. */

  140490. SQLITE_PRIVATE Bitmask sqlite3WhereExprUsageNN(WhereMaskSet *pMaskSet, Expr *p){

  140491.   Bitmask mask;

  140492.   if( p->op==TK_COLUMN && !ExprHasProperty(p, EP_FixedCol) ){

  140493.     return sqlite3WhereGetMask(pMaskSet, p->iTable);

  140494.   }else if( ExprHasProperty(p, EP_TokenOnly|EP_Leaf) ){

  140495.     assert( p->op!=TK_IF_NULL_ROW );

  140496.     return 0;

  140497.   }

  140498.   mask = (p->op==TK_IF_NULL_ROW) ? sqlite3WhereGetMask(pMaskSet, p->iTable) : 0;

  140499.   if( p->pLeft ) mask |= sqlite3WhereExprUsageNN(pMaskSet, p->pLeft);

  140500.   if( p->pRight ){

  140501.     mask |= sqlite3WhereExprUsageNN(pMaskSet, p->pRight);

  140502.     assert( p->x.pList==0 );

  140503.   }else if( ExprHasProperty(p, EP_xIsSelect) ){

  140504.     if( ExprHasProperty(p, EP_VarSelect) ) pMaskSet->bVarSelect = 1;

  140505.     mask |= exprSelectUsage(pMaskSet, p->x.pSelect);

  140506.   }else if( p->x.pList ){

  140507.     mask |= sqlite3WhereExprListUsage(pMaskSet, p->x.pList);

  140508.   }

  140509. #ifndef SQLITE_OMIT_WINDOWFUNC

  140510.   if( p->op==TK_FUNCTION && p->y.pWin ){

  140511.     mask |= sqlite3WhereExprListUsage(pMaskSet, p->y.pWin->pPartition);

  140512.     mask |= sqlite3WhereExprListUsage(pMaskSet, p->y.pWin->pOrderBy);

  140513.   }

  140514. #endif

  140515.   return mask;

  140516. }

  140517. SQLITE_PRIVATE Bitmask sqlite3WhereExprUsage(WhereMaskSet *pMaskSet, Expr *p){

  140518.   return p ? sqlite3WhereExprUsageNN(pMaskSet,p) : 0;

  140519. }

  140520. SQLITE_PRIVATE Bitmask sqlite3WhereExprListUsage(WhereMaskSet *pMaskSet, ExprList *pList){

  140521.   int i;

  140522.   Bitmask mask = 0;

  140523.   if( pList ){

  140524.     for(i=0; i<pList->nExpr; i++){

  140525.       mask |= sqlite3WhereExprUsage(pMaskSet, pList->a[i].pExpr);

  140526.     }

  140527.   }

  140528.   return mask;

  140529. }

  140530. 

  140531. 

  140532. /*

  140533. ** Call exprAnalyze on all terms in a WHERE clause.  

  140534. **

  140535. ** Note that exprAnalyze() might add new virtual terms onto the

  140536. ** end of the WHERE clause.  We do not want to analyze these new

  140537. ** virtual terms, so start analyzing at the end and work forward

  140538. ** so that the added virtual terms are never processed.

  140539. */

  140540. SQLITE_PRIVATE void sqlite3WhereExprAnalyze(

  140541.   SrcList *pTabList,       /* the FROM clause */

  140542.   WhereClause *pWC         /* the WHERE clause to be analyzed */

  140543. ){

  140544.   int i;

  140545.   for(i=pWC->nTerm-1; i>=0; i--){

  140546.     exprAnalyze(pTabList, pWC, i);

  140547.   }

  140548. }

  140549. 

  140550. /*

  140551. ** For table-valued-functions, transform the function arguments into

  140552. ** new WHERE clause terms.  

  140553. **

  140554. ** Each function argument translates into an equality constraint against

  140555. ** a HIDDEN column in the table.

  140556. */

  140557. SQLITE_PRIVATE void sqlite3WhereTabFuncArgs(

  140558.   Parse *pParse,                    /* Parsing context */

  140559.   struct SrcList_item *pItem,       /* The FROM clause term to process */

  140560.   WhereClause *pWC                  /* Xfer function arguments to here */

  140561. ){

  140562.   Table *pTab;

  140563.   int j, k;

  140564.   ExprList *pArgs;

  140565.   Expr *pColRef;

  140566.   Expr *pTerm;

  140567.   if( pItem->fg.isTabFunc==0 ) return;

  140568.   pTab = pItem->pTab;

  140569.   assert( pTab!=0 );

  140570.   pArgs = pItem->u1.pFuncArg;

  140571.   if( pArgs==0 ) return;

  140572.   for(j=k=0; j<pArgs->nExpr; j++){

  140573.     Expr *pRhs;

  140574.     while( k<pTab->nCol && (pTab->aCol[k].colFlags & COLFLAG_HIDDEN)==0 ){k++;}

  140575.     if( k>=pTab->nCol ){

  140576.       sqlite3ErrorMsg(pParse, "too many arguments on %s() - max %d",

  140577.                       pTab->zName, j);

  140578.       return;

  140579.     }

  140580.     pColRef = sqlite3ExprAlloc(pParse->db, TK_COLUMN, 0, 0);

  140581.     if( pColRef==0 ) return;

  140582.     pColRef->iTable = pItem->iCursor;

  140583.     pColRef->iColumn = k++;

  140584.     pColRef->y.pTab = pTab;

  140585.     pRhs = sqlite3PExpr(pParse, TK_UPLUS, 

  140586.         sqlite3ExprDup(pParse->db, pArgs->a[j].pExpr, 0), 0);

  140587.     pTerm = sqlite3PExpr(pParse, TK_EQ, pColRef, pRhs);

  140588.     whereClauseInsert(pWC, pTerm, TERM_DYNAMIC);

  140589.   }

  140590. }

  140591. 

  140592. /************** End of whereexpr.c *******************************************/

  140593. /************** Begin file where.c *******************************************/

  140594. /*

  140595. ** 2001 September 15

  140596. **

  140597. ** The author disclaims copyright to this source code.  In place of

  140598. ** a legal notice, here is a blessing:

  140599. **

  140600. **    May you do good and not evil.

  140601. **    May you find forgiveness for yourself and forgive others.

  140602. **    May you share freely, never taking more than you give.

  140603. **

  140604. *************************************************************************

  140605. ** This module contains C code that generates VDBE code used to process

  140606. ** the WHERE clause of SQL statements.  This module is responsible for

  140607. ** generating the code that loops through a table looking for applicable

  140608. ** rows.  Indices are selected and used to speed the search when doing

  140609. ** so is applicable.  Because this module is responsible for selecting

  140610. ** indices, you might also think of this module as the "query optimizer".

  140611. */

  140612. /* #include "sqliteInt.h" */

  140613. /* #include "whereInt.h" */

  140614. 

  140615. /*

  140616. ** Extra information appended to the end of sqlite3_index_info but not

  140617. ** visible to the xBestIndex function, at least not directly.  The

  140618. ** sqlite3_vtab_collation() interface knows how to reach it, however.

  140619. **

  140620. ** This object is not an API and can be changed from one release to the

  140621. ** next.  As long as allocateIndexInfo() and sqlite3_vtab_collation()

  140622. ** agree on the structure, all will be well.

  140623. */

  140624. typedef struct HiddenIndexInfo HiddenIndexInfo;

  140625. struct HiddenIndexInfo {

  140626.   WhereClause *pWC;   /* The Where clause being analyzed */

  140627.   Parse *pParse;      /* The parsing context */

  140628. };

  140629. 

  140630. /* Forward declaration of methods */

  140631. static int whereLoopResize(sqlite3*, WhereLoop*, int);

  140632. 

  140633. /* Test variable that can be set to enable WHERE tracing */

  140634. #if defined(SQLITE_TEST) || defined(SQLITE_DEBUG)

  140635. /***/ int sqlite3WhereTrace = 0;

  140636. #endif

  140637. 

  140638. 

  140639. /*

  140640. ** Return the estimated number of output rows from a WHERE clause

  140641. */

  140642. SQLITE_PRIVATE LogEst sqlite3WhereOutputRowCount(WhereInfo *pWInfo){

  140643.   return pWInfo->nRowOut;

  140644. }

  140645. 

  140646. /*

  140647. ** Return one of the WHERE_DISTINCT_xxxxx values to indicate how this

  140648. ** WHERE clause returns outputs for DISTINCT processing.

  140649. */

  140650. SQLITE_PRIVATE int sqlite3WhereIsDistinct(WhereInfo *pWInfo){

  140651.   return pWInfo->eDistinct;

  140652. }

  140653. 

  140654. /*

  140655. ** Return TRUE if the WHERE clause returns rows in ORDER BY order.

  140656. ** Return FALSE if the output needs to be sorted.

  140657. */

  140658. SQLITE_PRIVATE int sqlite3WhereIsOrdered(WhereInfo *pWInfo){

  140659.   return pWInfo->nOBSat;

  140660. }

  140661. 

  140662. /*

  140663. ** In the ORDER BY LIMIT optimization, if the inner-most loop is known

  140664. ** to emit rows in increasing order, and if the last row emitted by the

  140665. ** inner-most loop did not fit within the sorter, then we can skip all

  140666. ** subsequent rows for the current iteration of the inner loop (because they

  140667. ** will not fit in the sorter either) and continue with the second inner

  140668. ** loop - the loop immediately outside the inner-most.

  140669. **

  140670. ** When a row does not fit in the sorter (because the sorter already

  140671. ** holds LIMIT+OFFSET rows that are smaller), then a jump is made to the

  140672. ** label returned by this function.

  140673. **

  140674. ** If the ORDER BY LIMIT optimization applies, the jump destination should

  140675. ** be the continuation for the second-inner-most loop.  If the ORDER BY

  140676. ** LIMIT optimization does not apply, then the jump destination should

  140677. ** be the continuation for the inner-most loop.

  140678. **

  140679. ** It is always safe for this routine to return the continuation of the

  140680. ** inner-most loop, in the sense that a correct answer will result.  

  140681. ** Returning the continuation the second inner loop is an optimization

  140682. ** that might make the code run a little faster, but should not change

  140683. ** the final answer.

  140684. */

  140685. SQLITE_PRIVATE int sqlite3WhereOrderByLimitOptLabel(WhereInfo *pWInfo){

  140686.   WhereLevel *pInner;

  140687.   if( !pWInfo->bOrderedInnerLoop ){

  140688.     /* The ORDER BY LIMIT optimization does not apply.  Jump to the 

  140689.     ** continuation of the inner-most loop. */

  140690.     return pWInfo->iContinue;

  140691.   }

  140692.   pInner = &pWInfo->a[pWInfo->nLevel-1];

  140693.   assert( pInner->addrNxt!=0 );

  140694.   return pInner->addrNxt;

  140695. }

  140696. 

  140697. /*

  140698. ** Return the VDBE address or label to jump to in order to continue

  140699. ** immediately with the next row of a WHERE clause.

  140700. */

  140701. SQLITE_PRIVATE int sqlite3WhereContinueLabel(WhereInfo *pWInfo){

  140702.   assert( pWInfo->iContinue!=0 );

  140703.   return pWInfo->iContinue;

  140704. }

  140705. 

  140706. /*

  140707. ** Return the VDBE address or label to jump to in order to break

  140708. ** out of a WHERE loop.

  140709. */

  140710. SQLITE_PRIVATE int sqlite3WhereBreakLabel(WhereInfo *pWInfo){

  140711.   return pWInfo->iBreak;

  140712. }

  140713. 

  140714. /*

  140715. ** Return ONEPASS_OFF (0) if an UPDATE or DELETE statement is unable to

  140716. ** operate directly on the rowis returned by a WHERE clause.  Return

  140717. ** ONEPASS_SINGLE (1) if the statement can operation directly because only

  140718. ** a single row is to be changed.  Return ONEPASS_MULTI (2) if the one-pass

  140719. ** optimization can be used on multiple 

  140720. **

  140721. ** If the ONEPASS optimization is used (if this routine returns true)

  140722. ** then also write the indices of open cursors used by ONEPASS

  140723. ** into aiCur[0] and aiCur[1].  iaCur[0] gets the cursor of the data

  140724. ** table and iaCur[1] gets the cursor used by an auxiliary index.

  140725. ** Either value may be -1, indicating that cursor is not used.

  140726. ** Any cursors returned will have been opened for writing.

  140727. **

  140728. ** aiCur[0] and aiCur[1] both get -1 if the where-clause logic is

  140729. ** unable to use the ONEPASS optimization.

  140730. */

  140731. SQLITE_PRIVATE int sqlite3WhereOkOnePass(WhereInfo *pWInfo, int *aiCur){

  140732.   memcpy(aiCur, pWInfo->aiCurOnePass, sizeof(int)*2);

  140733. #ifdef WHERETRACE_ENABLED

  140734.   if( sqlite3WhereTrace && pWInfo->eOnePass!=ONEPASS_OFF ){

  140735.     sqlite3DebugPrintf("%s cursors: %d %d\n",

  140736.          pWInfo->eOnePass==ONEPASS_SINGLE ? "ONEPASS_SINGLE" : "ONEPASS_MULTI",

  140737.          aiCur[0], aiCur[1]);

  140738.   }

  140739. #endif

  140740.   return pWInfo->eOnePass;

  140741. }

  140742. 

  140743. /*

  140744. ** Move the content of pSrc into pDest

  140745. */

  140746. static void whereOrMove(WhereOrSet *pDest, WhereOrSet *pSrc){

  140747.   pDest->n = pSrc->n;

  140748.   memcpy(pDest->a, pSrc->a, pDest->n*sizeof(pDest->a[0]));

  140749. }

  140750. 

  140751. /*

  140752. ** Try to insert a new prerequisite/cost entry into the WhereOrSet pSet.

  140753. **

  140754. ** The new entry might overwrite an existing entry, or it might be

  140755. ** appended, or it might be discarded.  Do whatever is the right thing

  140756. ** so that pSet keeps the N_OR_COST best entries seen so far.

  140757. */

  140758. static int whereOrInsert(

  140759.   WhereOrSet *pSet,      /* The WhereOrSet to be updated */

  140760.   Bitmask prereq,        /* Prerequisites of the new entry */

  140761.   LogEst rRun,           /* Run-cost of the new entry */

  140762.   LogEst nOut            /* Number of outputs for the new entry */

  140763. ){

  140764.   u16 i;

  140765.   WhereOrCost *p;

  140766.   for(i=pSet->n, p=pSet->a; i>0; i--, p++){

  140767.     if( rRun<=p->rRun && (prereq & p->prereq)==prereq ){

  140768.       goto whereOrInsert_done;

  140769.     }

  140770.     if( p->rRun<=rRun && (p->prereq & prereq)==p->prereq ){

  140771.       return 0;

  140772.     }

  140773.   }

  140774.   if( pSet->n<N_OR_COST ){

  140775.     p = &pSet->a[pSet->n++];

  140776.     p->nOut = nOut;

  140777.   }else{

  140778.     p = pSet->a;

  140779.     for(i=1; i<pSet->n; i++){

  140780.       if( p->rRun>pSet->a[i].rRun ) p = pSet->a + i;

  140781.     }

  140782.     if( p->rRun<=rRun ) return 0;

  140783.   }

  140784. whereOrInsert_done:

  140785.   p->prereq = prereq;

  140786.   p->rRun = rRun;

  140787.   if( p->nOut>nOut ) p->nOut = nOut;

  140788.   return 1;

  140789. }

  140790. 

  140791. /*

  140792. ** Return the bitmask for the given cursor number.  Return 0 if

  140793. ** iCursor is not in the set.

  140794. */

  140795. SQLITE_PRIVATE Bitmask sqlite3WhereGetMask(WhereMaskSet *pMaskSet, int iCursor){

  140796.   int i;

  140797.   assert( pMaskSet->n<=(int)sizeof(Bitmask)*8 );

  140798.   for(i=0; i<pMaskSet->n; i++){

  140799.     if( pMaskSet->ix[i]==iCursor ){

  140800.       return MASKBIT(i);

  140801.     }

  140802.   }

  140803.   return 0;

  140804. }

  140805. 

  140806. /*

  140807. ** Create a new mask for cursor iCursor.

  140808. **

  140809. ** There is one cursor per table in the FROM clause.  The number of

  140810. ** tables in the FROM clause is limited by a test early in the

  140811. ** sqlite3WhereBegin() routine.  So we know that the pMaskSet->ix[]

  140812. ** array will never overflow.

  140813. */

  140814. static void createMask(WhereMaskSet *pMaskSet, int iCursor){

  140815.   assert( pMaskSet->n < ArraySize(pMaskSet->ix) );

  140816.   pMaskSet->ix[pMaskSet->n++] = iCursor;

  140817. }

  140818. 

  140819. /*

  140820. ** Advance to the next WhereTerm that matches according to the criteria

  140821. ** established when the pScan object was initialized by whereScanInit().

  140822. ** Return NULL if there are no more matching WhereTerms.

  140823. */

  140824. static WhereTerm *whereScanNext(WhereScan *pScan){

  140825.   int iCur;            /* The cursor on the LHS of the term */

  140826.   i16 iColumn;         /* The column on the LHS of the term.  -1 for IPK */

  140827.   Expr *pX;            /* An expression being tested */

  140828.   WhereClause *pWC;    /* Shorthand for pScan->pWC */

  140829.   WhereTerm *pTerm;    /* The term being tested */

  140830.   int k = pScan->k;    /* Where to start scanning */

  140831. 

  140832.   assert( pScan->iEquiv<=pScan->nEquiv );

  140833.   pWC = pScan->pWC;

  140834.   while(1){

  140835.     iColumn = pScan->aiColumn[pScan->iEquiv-1];

  140836.     iCur = pScan->aiCur[pScan->iEquiv-1];

  140837.     assert( pWC!=0 );

  140838.     do{

  140839.       for(pTerm=pWC->a+k; k<pWC->nTerm; k++, pTerm++){

  140840.         if( pTerm->leftCursor==iCur

  140841.          && pTerm->u.leftColumn==iColumn

  140842.          && (iColumn!=XN_EXPR

  140843.              || sqlite3ExprCompareSkip(pTerm->pExpr->pLeft,

  140844.                                        pScan->pIdxExpr,iCur)==0)

  140845.          && (pScan->iEquiv<=1 || !ExprHasProperty(pTerm->pExpr, EP_FromJoin))

  140846.         ){

  140847.           if( (pTerm->eOperator & WO_EQUIV)!=0

  140848.            && pScan->nEquiv<ArraySize(pScan->aiCur)

  140849.            && (pX = sqlite3ExprSkipCollate(pTerm->pExpr->pRight))->op==TK_COLUMN

  140850.           ){

  140851.             int j;

  140852.             for(j=0; j<pScan->nEquiv; j++){

  140853.               if( pScan->aiCur[j]==pX->iTable

  140854.                && pScan->aiColumn[j]==pX->iColumn ){

  140855.                   break;

  140856.               }

  140857.             }

  140858.             if( j==pScan->nEquiv ){

  140859.               pScan->aiCur[j] = pX->iTable;

  140860.               pScan->aiColumn[j] = pX->iColumn;

  140861.               pScan->nEquiv++;

  140862.             }

  140863.           }

  140864.           if( (pTerm->eOperator & pScan->opMask)!=0 ){

  140865.             /* Verify the affinity and collating sequence match */

  140866.             if( pScan->zCollName && (pTerm->eOperator & WO_ISNULL)==0 ){

  140867.               CollSeq *pColl;

  140868.               Parse *pParse = pWC->pWInfo->pParse;

  140869.               pX = pTerm->pExpr;

  140870.               if( !sqlite3IndexAffinityOk(pX, pScan->idxaff) ){

  140871.                 continue;

  140872.               }

  140873.               assert(pX->pLeft);

  140874.               pColl = sqlite3BinaryCompareCollSeq(pParse,

  140875.                                                   pX->pLeft, pX->pRight);

  140876.               if( pColl==0 ) pColl = pParse->db->pDfltColl;

  140877.               if( sqlite3StrICmp(pColl->zName, pScan->zCollName) ){

  140878.                 continue;

  140879.               }

  140880.             }

  140881.             if( (pTerm->eOperator & (WO_EQ|WO_IS))!=0

  140882.              && (pX = pTerm->pExpr->pRight)->op==TK_COLUMN

  140883.              && pX->iTable==pScan->aiCur[0]

  140884.              && pX->iColumn==pScan->aiColumn[0]

  140885.             ){

  140886.               testcase( pTerm->eOperator & WO_IS );

  140887.               continue;

  140888.             }

  140889.             pScan->pWC = pWC;

  140890.             pScan->k = k+1;

  140891.             return pTerm;

  140892.           }

  140893.         }

  140894.       }

  140895.       pWC = pWC->pOuter;

  140896.       k = 0;

  140897.     }while( pWC!=0 );

  140898.     if( pScan->iEquiv>=pScan->nEquiv ) break;

  140899.     pWC = pScan->pOrigWC;

  140900.     k = 0;

  140901.     pScan->iEquiv++;

  140902.   }

  140903.   return 0;

  140904. }

  140905. 

  140906. /*

  140907. ** This is whereScanInit() for the case of an index on an expression.

  140908. ** It is factored out into a separate tail-recursion subroutine so that

  140909. ** the normal whereScanInit() routine, which is a high-runner, does not

  140910. ** need to push registers onto the stack as part of its prologue.

  140911. */

  140912. static SQLITE_NOINLINE WhereTerm *whereScanInitIndexExpr(WhereScan *pScan){

  140913.   pScan->idxaff = sqlite3ExprAffinity(pScan->pIdxExpr);

  140914.   return whereScanNext(pScan);

  140915. }

  140916. 

  140917. /*

  140918. ** Initialize a WHERE clause scanner object.  Return a pointer to the

  140919. ** first match.  Return NULL if there are no matches.

  140920. **

  140921. ** The scanner will be searching the WHERE clause pWC.  It will look

  140922. ** for terms of the form "X <op> <expr>" where X is column iColumn of table

  140923. ** iCur.   Or if pIdx!=0 then X is column iColumn of index pIdx.  pIdx

  140924. ** must be one of the indexes of table iCur.

  140925. **

  140926. ** The <op> must be one of the operators described by opMask.

  140927. **

  140928. ** If the search is for X and the WHERE clause contains terms of the

  140929. ** form X=Y then this routine might also return terms of the form

  140930. ** "Y <op> <expr>".  The number of levels of transitivity is limited,

  140931. ** but is enough to handle most commonly occurring SQL statements.

  140932. **

  140933. ** If X is not the INTEGER PRIMARY KEY then X must be compatible with

  140934. ** index pIdx.

  140935. */

  140936. static WhereTerm *whereScanInit(

  140937.   WhereScan *pScan,       /* The WhereScan object being initialized */

  140938.   WhereClause *pWC,       /* The WHERE clause to be scanned */

  140939.   int iCur,               /* Cursor to scan for */

  140940.   int iColumn,            /* Column to scan for */

  140941.   u32 opMask,             /* Operator(s) to scan for */

  140942.   Index *pIdx             /* Must be compatible with this index */

  140943. ){

  140944.   pScan->pOrigWC = pWC;

  140945.   pScan->pWC = pWC;

  140946.   pScan->pIdxExpr = 0;

  140947.   pScan->idxaff = 0;

  140948.   pScan->zCollName = 0;

  140949.   pScan->opMask = opMask;

  140950.   pScan->k = 0;

  140951.   pScan->aiCur[0] = iCur;

  140952.   pScan->nEquiv = 1;

  140953.   pScan->iEquiv = 1;

  140954.   if( pIdx ){

  140955.     int j = iColumn;

  140956.     iColumn = pIdx->aiColumn[j];

  140957.     if( iColumn==XN_EXPR ){

  140958.       pScan->pIdxExpr = pIdx->aColExpr->a[j].pExpr;

  140959.       pScan->zCollName = pIdx->azColl[j];

  140960.       pScan->aiColumn[0] = XN_EXPR;

  140961.       return whereScanInitIndexExpr(pScan);

  140962.     }else if( iColumn==pIdx->pTable->iPKey ){

  140963.       iColumn = XN_ROWID;

  140964.     }else if( iColumn>=0 ){

  140965.       pScan->idxaff = pIdx->pTable->aCol[iColumn].affinity;

  140966.       pScan->zCollName = pIdx->azColl[j];

  140967.     }

  140968.   }else if( iColumn==XN_EXPR ){

  140969.     return 0;

  140970.   }

  140971.   pScan->aiColumn[0] = iColumn;

  140972.   return whereScanNext(pScan);

  140973. }

  140974. 

  140975. /*

  140976. ** Search for a term in the WHERE clause that is of the form "X <op> <expr>"

  140977. ** where X is a reference to the iColumn of table iCur or of index pIdx

  140978. ** if pIdx!=0 and <op> is one of the WO_xx operator codes specified by

  140979. ** the op parameter.  Return a pointer to the term.  Return 0 if not found.

  140980. **

  140981. ** If pIdx!=0 then it must be one of the indexes of table iCur.  

  140982. ** Search for terms matching the iColumn-th column of pIdx

  140983. ** rather than the iColumn-th column of table iCur.

  140984. **

  140985. ** The term returned might by Y=<expr> if there is another constraint in

  140986. ** the WHERE clause that specifies that X=Y.  Any such constraints will be

  140987. ** identified by the WO_EQUIV bit in the pTerm->eOperator field.  The

  140988. ** aiCur[]/iaColumn[] arrays hold X and all its equivalents. There are 11

  140989. ** slots in aiCur[]/aiColumn[] so that means we can look for X plus up to 10

  140990. ** other equivalent values.  Hence a search for X will return <expr> if X=A1

  140991. ** and A1=A2 and A2=A3 and ... and A9=A10 and A10=<expr>.

  140992. **

  140993. ** If there are multiple terms in the WHERE clause of the form "X <op> <expr>"

  140994. ** then try for the one with no dependencies on <expr> - in other words where

  140995. ** <expr> is a constant expression of some kind.  Only return entries of

  140996. ** the form "X <op> Y" where Y is a column in another table if no terms of

  140997. ** the form "X <op> <const-expr>" exist.   If no terms with a constant RHS

  140998. ** exist, try to return a term that does not use WO_EQUIV.

  140999. */

  141000. SQLITE_PRIVATE WhereTerm *sqlite3WhereFindTerm(

  141001.   WhereClause *pWC,     /* The WHERE clause to be searched */

  141002.   int iCur,             /* Cursor number of LHS */

  141003.   int iColumn,          /* Column number of LHS */

  141004.   Bitmask notReady,     /* RHS must not overlap with this mask */

  141005.   u32 op,               /* Mask of WO_xx values describing operator */

  141006.   Index *pIdx           /* Must be compatible with this index, if not NULL */

  141007. ){

  141008.   WhereTerm *pResult = 0;

  141009.   WhereTerm *p;

  141010.   WhereScan scan;

  141011. 

  141012.   p = whereScanInit(&scan, pWC, iCur, iColumn, op, pIdx);

  141013.   op &= WO_EQ|WO_IS;

  141014.   while( p ){

  141015.     if( (p->prereqRight & notReady)==0 ){

  141016.       if( p->prereqRight==0 && (p->eOperator&op)!=0 ){

  141017.         testcase( p->eOperator & WO_IS );

  141018.         return p;

  141019.       }

  141020.       if( pResult==0 ) pResult = p;

  141021.     }

  141022.     p = whereScanNext(&scan);

  141023.   }

  141024.   return pResult;

  141025. }

  141026. 

  141027. /*

  141028. ** This function searches pList for an entry that matches the iCol-th column

  141029. ** of index pIdx.

  141030. **

  141031. ** If such an expression is found, its index in pList->a[] is returned. If

  141032. ** no expression is found, -1 is returned.

  141033. */

  141034. static int findIndexCol(

  141035.   Parse *pParse,                  /* Parse context */

  141036.   ExprList *pList,                /* Expression list to search */

  141037.   int iBase,                      /* Cursor for table associated with pIdx */

  141038.   Index *pIdx,                    /* Index to match column of */

  141039.   int iCol                        /* Column of index to match */

  141040. ){

  141041.   int i;

  141042.   const char *zColl = pIdx->azColl[iCol];

  141043. 

  141044.   for(i=0; i<pList->nExpr; i++){

  141045.     Expr *p = sqlite3ExprSkipCollate(pList->a[i].pExpr);

  141046.     if( p->op==TK_COLUMN

  141047.      && p->iColumn==pIdx->aiColumn[iCol]

  141048.      && p->iTable==iBase

  141049.     ){

  141050.       CollSeq *pColl = sqlite3ExprNNCollSeq(pParse, pList->a[i].pExpr);

  141051.       if( 0==sqlite3StrICmp(pColl->zName, zColl) ){

  141052.         return i;

  141053.       }

  141054.     }

  141055.   }

  141056. 

  141057.   return -1;

  141058. }

  141059. 

  141060. /*

  141061. ** Return TRUE if the iCol-th column of index pIdx is NOT NULL

  141062. */

  141063. static int indexColumnNotNull(Index *pIdx, int iCol){

  141064.   int j;

  141065.   assert( pIdx!=0 );

  141066.   assert( iCol>=0 && iCol<pIdx->nColumn );

  141067.   j = pIdx->aiColumn[iCol];

  141068.   if( j>=0 ){

  141069.     return pIdx->pTable->aCol[j].notNull;

  141070.   }else if( j==(-1) ){

  141071.     return 1;

  141072.   }else{

  141073.     assert( j==(-2) );

  141074.     return 0;  /* Assume an indexed expression can always yield a NULL */

  141075. 

  141076.   }

  141077. }

  141078. 

  141079. /*

  141080. ** Return true if the DISTINCT expression-list passed as the third argument

  141081. ** is redundant.

  141082. **

  141083. ** A DISTINCT list is redundant if any subset of the columns in the

  141084. ** DISTINCT list are collectively unique and individually non-null.

  141085. */

  141086. static int isDistinctRedundant(

  141087.   Parse *pParse,            /* Parsing context */

  141088.   SrcList *pTabList,        /* The FROM clause */

  141089.   WhereClause *pWC,         /* The WHERE clause */

  141090.   ExprList *pDistinct       /* The result set that needs to be DISTINCT */

  141091. ){

  141092.   Table *pTab;

  141093.   Index *pIdx;

  141094.   int i;                          

  141095.   int iBase;

  141096. 

  141097.   /* If there is more than one table or sub-select in the FROM clause of

  141098.   ** this query, then it will not be possible to show that the DISTINCT 

  141099.   ** clause is redundant. */

  141100.   if( pTabList->nSrc!=1 ) return 0;

  141101.   iBase = pTabList->a[0].iCursor;

  141102.   pTab = pTabList->a[0].pTab;

  141103. 

  141104.   /* If any of the expressions is an IPK column on table iBase, then return 

  141105.   ** true. Note: The (p->iTable==iBase) part of this test may be false if the

  141106.   ** current SELECT is a correlated sub-query.

  141107.   */

  141108.   for(i=0; i<pDistinct->nExpr; i++){

  141109.     Expr *p = sqlite3ExprSkipCollate(pDistinct->a[i].pExpr);

  141110.     if( p->op==TK_COLUMN && p->iTable==iBase && p->iColumn<0 ) return 1;

  141111.   }

  141112. 

  141113.   /* Loop through all indices on the table, checking each to see if it makes

  141114.   ** the DISTINCT qualifier redundant. It does so if:

  141115.   **

  141116.   **   1. The index is itself UNIQUE, and

  141117.   **

  141118.   **   2. All of the columns in the index are either part of the pDistinct

  141119.   **      list, or else the WHERE clause contains a term of the form "col=X",

  141120.   **      where X is a constant value. The collation sequences of the

  141121.   **      comparison and select-list expressions must match those of the index.

  141122.   **

  141123.   **   3. All of those index columns for which the WHERE clause does not

  141124.   **      contain a "col=X" term are subject to a NOT NULL constraint.

  141125.   */

  141126.   for(pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext){

  141127.     if( !IsUniqueIndex(pIdx) ) continue;

  141128.     for(i=0; i<pIdx->nKeyCol; i++){

  141129.       if( 0==sqlite3WhereFindTerm(pWC, iBase, i, ~(Bitmask)0, WO_EQ, pIdx) ){

  141130.         if( findIndexCol(pParse, pDistinct, iBase, pIdx, i)<0 ) break;

  141131.         if( indexColumnNotNull(pIdx, i)==0 ) break;

  141132.       }

  141133.     }

  141134.     if( i==pIdx->nKeyCol ){

  141135.       /* This index implies that the DISTINCT qualifier is redundant. */

  141136.       return 1;

  141137.     }

  141138.   }

  141139. 

  141140.   return 0;

  141141. }

  141142. 

  141143. 

  141144. /*

  141145. ** Estimate the logarithm of the input value to base 2.

  141146. */

  141147. static LogEst estLog(LogEst N){

  141148.   return N<=10 ? 0 : sqlite3LogEst(N) - 33;

  141149. }

  141150. 

  141151. /*

  141152. ** Convert OP_Column opcodes to OP_Copy in previously generated code.

  141153. **

  141154. ** This routine runs over generated VDBE code and translates OP_Column

  141155. ** opcodes into OP_Copy when the table is being accessed via co-routine 

  141156. ** instead of via table lookup.

  141157. **

  141158. ** If the iAutoidxCur is not zero, then any OP_Rowid instructions on

  141159. ** cursor iTabCur are transformed into OP_Sequence opcode for the

  141160. ** iAutoidxCur cursor, in order to generate unique rowids for the

  141161. ** automatic index being generated.

  141162. */

  141163. static void translateColumnToCopy(

  141164.   Parse *pParse,      /* Parsing context */

  141165.   int iStart,         /* Translate from this opcode to the end */

  141166.   int iTabCur,        /* OP_Column/OP_Rowid references to this table */

  141167.   int iRegister,      /* The first column is in this register */

  141168.   int iAutoidxCur     /* If non-zero, cursor of autoindex being generated */

  141169. ){

  141170.   Vdbe *v = pParse->pVdbe;

  141171.   VdbeOp *pOp = sqlite3VdbeGetOp(v, iStart);

  141172.   int iEnd = sqlite3VdbeCurrentAddr(v);

  141173.   if( pParse->db->mallocFailed ) return;

  141174.   for(; iStart<iEnd; iStart++, pOp++){

  141175.     if( pOp->p1!=iTabCur ) continue;

  141176.     if( pOp->opcode==OP_Column ){

  141177.       pOp->opcode = OP_Copy;

  141178.       pOp->p1 = pOp->p2 + iRegister;

  141179.       pOp->p2 = pOp->p3;

  141180.       pOp->p3 = 0;

  141181.     }else if( pOp->opcode==OP_Rowid ){

  141182.       if( iAutoidxCur ){

  141183.         pOp->opcode = OP_Sequence;

  141184.         pOp->p1 = iAutoidxCur;

  141185.       }else{

  141186.         pOp->opcode = OP_Null;

  141187.         pOp->p1 = 0;

  141188.         pOp->p3 = 0;

  141189.       }

  141190.     }

  141191.   }

  141192. }

  141193. 

  141194. /*

  141195. ** Two routines for printing the content of an sqlite3_index_info

  141196. ** structure.  Used for testing and debugging only.  If neither

  141197. ** SQLITE_TEST or SQLITE_DEBUG are defined, then these routines

  141198. ** are no-ops.

  141199. */

  141200. #if !defined(SQLITE_OMIT_VIRTUALTABLE) && defined(WHERETRACE_ENABLED)

  141201. static void TRACE_IDX_INPUTS(sqlite3_index_info *p){

  141202.   int i;

  141203.   if( !sqlite3WhereTrace ) return;

  141204.   for(i=0; i<p->nConstraint; i++){

  141205.     sqlite3DebugPrintf("  constraint[%d]: col=%d termid=%d op=%d usabled=%d\n",

  141206.        i,

  141207.        p->aConstraint[i].iColumn,

  141208.        p->aConstraint[i].iTermOffset,

  141209.        p->aConstraint[i].op,

  141210.        p->aConstraint[i].usable);

  141211.   }

  141212.   for(i=0; i<p->nOrderBy; i++){

  141213.     sqlite3DebugPrintf("  orderby[%d]: col=%d desc=%d\n",

  141214.        i,

  141215.        p->aOrderBy[i].iColumn,

  141216.        p->aOrderBy[i].desc);

  141217.   }

  141218. }

  141219. static void TRACE_IDX_OUTPUTS(sqlite3_index_info *p){

  141220.   int i;

  141221.   if( !sqlite3WhereTrace ) return;

  141222.   for(i=0; i<p->nConstraint; i++){

  141223.     sqlite3DebugPrintf("  usage[%d]: argvIdx=%d omit=%d\n",

  141224.        i,

  141225.        p->aConstraintUsage[i].argvIndex,

  141226.        p->aConstraintUsage[i].omit);

  141227.   }

  141228.   sqlite3DebugPrintf("  idxNum=%d\n", p->idxNum);

  141229.   sqlite3DebugPrintf("  idxStr=%s\n", p->idxStr);

  141230.   sqlite3DebugPrintf("  orderByConsumed=%d\n", p->orderByConsumed);

  141231.   sqlite3DebugPrintf("  estimatedCost=%g\n", p->estimatedCost);

  141232.   sqlite3DebugPrintf("  estimatedRows=%lld\n", p->estimatedRows);

  141233. }

  141234. #else

  141235. #define TRACE_IDX_INPUTS(A)

  141236. #define TRACE_IDX_OUTPUTS(A)

  141237. #endif

  141238. 

  141239. #ifndef SQLITE_OMIT_AUTOMATIC_INDEX

  141240. /*

  141241. ** Return TRUE if the WHERE clause term pTerm is of a form where it

  141242. ** could be used with an index to access pSrc, assuming an appropriate

  141243. ** index existed.

  141244. */

  141245. static int termCanDriveIndex(

  141246.   WhereTerm *pTerm,              /* WHERE clause term to check */

  141247.   struct SrcList_item *pSrc,     /* Table we are trying to access */

  141248.   Bitmask notReady               /* Tables in outer loops of the join */

  141249. ){

  141250.   char aff;

  141251.   if( pTerm->leftCursor!=pSrc->iCursor ) return 0;

  141252.   if( (pTerm->eOperator & (WO_EQ|WO_IS))==0 ) return 0;

  141253.   if( (pSrc->fg.jointype & JT_LEFT) 

  141254.    && !ExprHasProperty(pTerm->pExpr, EP_FromJoin)

  141255.    && (pTerm->eOperator & WO_IS)

  141256.   ){

  141257.     /* Cannot use an IS term from the WHERE clause as an index driver for

  141258.     ** the RHS of a LEFT JOIN. Such a term can only be used if it is from

  141259.     ** the ON clause.  */

  141260.     return 0;

  141261.   }

  141262.   if( (pTerm->prereqRight & notReady)!=0 ) return 0;

  141263.   if( pTerm->u.leftColumn<0 ) return 0;

  141264.   aff = pSrc->pTab->aCol[pTerm->u.leftColumn].affinity;

  141265.   if( !sqlite3IndexAffinityOk(pTerm->pExpr, aff) ) return 0;

  141266.   testcase( pTerm->pExpr->op==TK_IS );

  141267.   return 1;

  141268. }

  141269. #endif

  141270. 

  141271. 

  141272. #ifndef SQLITE_OMIT_AUTOMATIC_INDEX

  141273. /*

  141274. ** Generate code to construct the Index object for an automatic index

  141275. ** and to set up the WhereLevel object pLevel so that the code generator

  141276. ** makes use of the automatic index.

  141277. */

  141278. static void constructAutomaticIndex(

  141279.   Parse *pParse,              /* The parsing context */

  141280.   WhereClause *pWC,           /* The WHERE clause */

  141281.   struct SrcList_item *pSrc,  /* The FROM clause term to get the next index */

  141282.   Bitmask notReady,           /* Mask of cursors that are not available */

  141283.   WhereLevel *pLevel          /* Write new index here */

  141284. ){

  141285.   int nKeyCol;                /* Number of columns in the constructed index */

  141286.   WhereTerm *pTerm;           /* A single term of the WHERE clause */

  141287.   WhereTerm *pWCEnd;          /* End of pWC->a[] */

  141288.   Index *pIdx;                /* Object describing the transient index */

  141289.   Vdbe *v;                    /* Prepared statement under construction */

  141290.   int addrInit;               /* Address of the initialization bypass jump */

  141291.   Table *pTable;              /* The table being indexed */

  141292.   int addrTop;                /* Top of the index fill loop */

  141293.   int regRecord;              /* Register holding an index record */

  141294.   int n;                      /* Column counter */

  141295.   int i;                      /* Loop counter */

  141296.   int mxBitCol;               /* Maximum column in pSrc->colUsed */

  141297.   CollSeq *pColl;             /* Collating sequence to on a column */

  141298.   WhereLoop *pLoop;           /* The Loop object */

  141299.   char *zNotUsed;             /* Extra space on the end of pIdx */

  141300.   Bitmask idxCols;            /* Bitmap of columns used for indexing */

  141301.   Bitmask extraCols;          /* Bitmap of additional columns */

  141302.   u8 sentWarning = 0;         /* True if a warnning has been issued */

  141303.   Expr *pPartial = 0;         /* Partial Index Expression */

  141304.   int iContinue = 0;          /* Jump here to skip excluded rows */

  141305.   struct SrcList_item *pTabItem;  /* FROM clause term being indexed */

  141306.   int addrCounter = 0;        /* Address where integer counter is initialized */

  141307.   int regBase;                /* Array of registers where record is assembled */

  141308. 

  141309.   /* Generate code to skip over the creation and initialization of the

  141310.   ** transient index on 2nd and subsequent iterations of the loop. */

  141311.   v = pParse->pVdbe;

  141312.   assert( v!=0 );

  141313.   addrInit = sqlite3VdbeAddOp0(v, OP_Once); VdbeCoverage(v);

  141314. 

  141315.   /* Count the number of columns that will be added to the index

  141316.   ** and used to match WHERE clause constraints */

  141317.   nKeyCol = 0;

  141318.   pTable = pSrc->pTab;

  141319.   pWCEnd = &pWC->a[pWC->nTerm];

  141320.   pLoop = pLevel->pWLoop;

  141321.   idxCols = 0;

  141322.   for(pTerm=pWC->a; pTerm<pWCEnd; pTerm++){

  141323.     Expr *pExpr = pTerm->pExpr;

  141324.     assert( !ExprHasProperty(pExpr, EP_FromJoin)    /* prereq always non-zero */

  141325.          || pExpr->iRightJoinTable!=pSrc->iCursor   /*   for the right-hand   */

  141326.          || pLoop->prereq!=0 );                     /*   table of a LEFT JOIN */

  141327.     if( pLoop->prereq==0

  141328.      && (pTerm->wtFlags & TERM_VIRTUAL)==0

  141329.      && !ExprHasProperty(pExpr, EP_FromJoin)

  141330.      && sqlite3ExprIsTableConstant(pExpr, pSrc->iCursor) ){

  141331.       pPartial = sqlite3ExprAnd(pParse, pPartial,

  141332.                                 sqlite3ExprDup(pParse->db, pExpr, 0));

  141333.     }

  141334.     if( termCanDriveIndex(pTerm, pSrc, notReady) ){

  141335.       int iCol = pTerm->u.leftColumn;

  141336.       Bitmask cMask = iCol>=BMS ? MASKBIT(BMS-1) : MASKBIT(iCol);

  141337.       testcase( iCol==BMS );

  141338.       testcase( iCol==BMS-1 );

  141339.       if( !sentWarning ){

  141340.         sqlite3_log(SQLITE_WARNING_AUTOINDEX,

  141341.             "automatic index on %s(%s)", pTable->zName,

  141342.             pTable->aCol[iCol].zName);

  141343.         sentWarning = 1;

  141344.       }

  141345.       if( (idxCols & cMask)==0 ){

  141346.         if( whereLoopResize(pParse->db, pLoop, nKeyCol+1) ){

  141347.           goto end_auto_index_create;

  141348.         }

  141349.         pLoop->aLTerm[nKeyCol++] = pTerm;

  141350.         idxCols |= cMask;

  141351.       }

  141352.     }

  141353.   }

  141354.   assert( nKeyCol>0 );

  141355.   pLoop->u.btree.nEq = pLoop->nLTerm = nKeyCol;

  141356.   pLoop->wsFlags = WHERE_COLUMN_EQ | WHERE_IDX_ONLY | WHERE_INDEXED

  141357.                      | WHERE_AUTO_INDEX;

  141358. 

  141359.   /* Count the number of additional columns needed to create a

  141360.   ** covering index.  A "covering index" is an index that contains all

  141361.   ** columns that are needed by the query.  With a covering index, the

  141362.   ** original table never needs to be accessed.  Automatic indices must

  141363.   ** be a covering index because the index will not be updated if the

  141364.   ** original table changes and the index and table cannot both be used

  141365.   ** if they go out of sync.

  141366.   */

  141367.   extraCols = pSrc->colUsed & (~idxCols | MASKBIT(BMS-1));

  141368.   mxBitCol = MIN(BMS-1,pTable->nCol);

  141369.   testcase( pTable->nCol==BMS-1 );

  141370.   testcase( pTable->nCol==BMS-2 );

  141371.   for(i=0; i<mxBitCol; i++){

  141372.     if( extraCols & MASKBIT(i) ) nKeyCol++;

  141373.   }

  141374.   if( pSrc->colUsed & MASKBIT(BMS-1) ){

  141375.     nKeyCol += pTable->nCol - BMS + 1;

  141376.   }

  141377. 

  141378.   /* Construct the Index object to describe this index */

  141379.   pIdx = sqlite3AllocateIndexObject(pParse->db, nKeyCol+1, 0, &zNotUsed);

  141380.   if( pIdx==0 ) goto end_auto_index_create;

  141381.   pLoop->u.btree.pIndex = pIdx;

  141382.   pIdx->zName = "auto-index";

  141383.   pIdx->pTable = pTable;

  141384.   n = 0;

  141385.   idxCols = 0;

  141386.   for(pTerm=pWC->a; pTerm<pWCEnd; pTerm++){

  141387.     if( termCanDriveIndex(pTerm, pSrc, notReady) ){

  141388.       int iCol = pTerm->u.leftColumn;

  141389.       Bitmask cMask = iCol>=BMS ? MASKBIT(BMS-1) : MASKBIT(iCol);

  141390.       testcase( iCol==BMS-1 );

  141391.       testcase( iCol==BMS );

  141392.       if( (idxCols & cMask)==0 ){

  141393.         Expr *pX = pTerm->pExpr;

  141394.         idxCols |= cMask;

  141395.         pIdx->aiColumn[n] = pTerm->u.leftColumn;

  141396.         pColl = sqlite3BinaryCompareCollSeq(pParse, pX->pLeft, pX->pRight);

  141397.         pIdx->azColl[n] = pColl ? pColl->zName : sqlite3StrBINARY;

  141398.         n++;

  141399.       }

  141400.     }

  141401.   }

  141402.   assert( (u32)n==pLoop->u.btree.nEq );

  141403. 

  141404.   /* Add additional columns needed to make the automatic index into

  141405.   ** a covering index */

  141406.   for(i=0; i<mxBitCol; i++){

  141407.     if( extraCols & MASKBIT(i) ){

  141408.       pIdx->aiColumn[n] = i;

  141409.       pIdx->azColl[n] = sqlite3StrBINARY;

  141410.       n++;

  141411.     }

  141412.   }

  141413.   if( pSrc->colUsed & MASKBIT(BMS-1) ){

  141414.     for(i=BMS-1; i<pTable->nCol; i++){

  141415.       pIdx->aiColumn[n] = i;

  141416.       pIdx->azColl[n] = sqlite3StrBINARY;

  141417.       n++;

  141418.     }

  141419.   }

  141420.   assert( n==nKeyCol );

  141421.   pIdx->aiColumn[n] = XN_ROWID;

  141422.   pIdx->azColl[n] = sqlite3StrBINARY;

  141423. 

  141424.   /* Create the automatic index */

  141425.   assert( pLevel->iIdxCur>=0 );

  141426.   pLevel->iIdxCur = pParse->nTab++;

  141427.   sqlite3VdbeAddOp2(v, OP_OpenAutoindex, pLevel->iIdxCur, nKeyCol+1);

  141428.   sqlite3VdbeSetP4KeyInfo(pParse, pIdx);

  141429.   VdbeComment((v, "for %s", pTable->zName));

  141430. 

  141431.   /* Fill the automatic index with content */

  141432.   pTabItem = &pWC->pWInfo->pTabList->a[pLevel->iFrom];

  141433.   if( pTabItem->fg.viaCoroutine ){

  141434.     int regYield = pTabItem->regReturn;

  141435.     addrCounter = sqlite3VdbeAddOp2(v, OP_Integer, 0, 0);

  141436.     sqlite3VdbeAddOp3(v, OP_InitCoroutine, regYield, 0, pTabItem->addrFillSub);

  141437.     addrTop =  sqlite3VdbeAddOp1(v, OP_Yield, regYield);

  141438.     VdbeCoverage(v);

  141439.     VdbeComment((v, "next row of %s", pTabItem->pTab->zName));

  141440.   }else{

  141441.     addrTop = sqlite3VdbeAddOp1(v, OP_Rewind, pLevel->iTabCur); VdbeCoverage(v);

  141442.   }

  141443.   if( pPartial ){

  141444.     iContinue = sqlite3VdbeMakeLabel(pParse);

  141445.     sqlite3ExprIfFalse(pParse, pPartial, iContinue, SQLITE_JUMPIFNULL);

  141446.     pLoop->wsFlags |= WHERE_PARTIALIDX;

  141447.   }

  141448.   regRecord = sqlite3GetTempReg(pParse);

  141449.   regBase = sqlite3GenerateIndexKey(

  141450.       pParse, pIdx, pLevel->iTabCur, regRecord, 0, 0, 0, 0

  141451.   );

  141452.   sqlite3VdbeAddOp2(v, OP_IdxInsert, pLevel->iIdxCur, regRecord);

  141453.   sqlite3VdbeChangeP5(v, OPFLAG_USESEEKRESULT);

  141454.   if( pPartial ) sqlite3VdbeResolveLabel(v, iContinue);

  141455.   if( pTabItem->fg.viaCoroutine ){

  141456.     sqlite3VdbeChangeP2(v, addrCounter, regBase+n);

  141457.     testcase( pParse->db->mallocFailed );

  141458.     assert( pLevel->iIdxCur>0 );

  141459.     translateColumnToCopy(pParse, addrTop, pLevel->iTabCur,

  141460.                           pTabItem->regResult, pLevel->iIdxCur);

  141461.     sqlite3VdbeGoto(v, addrTop);

  141462.     pTabItem->fg.viaCoroutine = 0;

  141463.   }else{

  141464.     sqlite3VdbeAddOp2(v, OP_Next, pLevel->iTabCur, addrTop+1); VdbeCoverage(v);

  141465.   }

  141466.   sqlite3VdbeChangeP5(v, SQLITE_STMTSTATUS_AUTOINDEX);

  141467.   sqlite3VdbeJumpHere(v, addrTop);

  141468.   sqlite3ReleaseTempReg(pParse, regRecord);

  141469.   

  141470.   /* Jump here when skipping the initialization */

  141471.   sqlite3VdbeJumpHere(v, addrInit);

  141472. 

  141473. end_auto_index_create:

  141474.   sqlite3ExprDelete(pParse->db, pPartial);

  141475. }

  141476. #endif /* SQLITE_OMIT_AUTOMATIC_INDEX */

  141477. 

  141478. #ifndef SQLITE_OMIT_VIRTUALTABLE

  141479. /*

  141480. ** Allocate and populate an sqlite3_index_info structure. It is the 

  141481. ** responsibility of the caller to eventually release the structure

  141482. ** by passing the pointer returned by this function to sqlite3_free().

  141483. */

  141484. static sqlite3_index_info *allocateIndexInfo(

  141485.   Parse *pParse,                  /* The parsing context */

  141486.   WhereClause *pWC,               /* The WHERE clause being analyzed */

  141487.   Bitmask mUnusable,              /* Ignore terms with these prereqs */

  141488.   struct SrcList_item *pSrc,      /* The FROM clause term that is the vtab */

  141489.   ExprList *pOrderBy,             /* The ORDER BY clause */

  141490.   u16 *pmNoOmit                   /* Mask of terms not to omit */

  141491. ){

  141492.   int i, j;

  141493.   int nTerm;

  141494.   struct sqlite3_index_constraint *pIdxCons;

  141495.   struct sqlite3_index_orderby *pIdxOrderBy;

  141496.   struct sqlite3_index_constraint_usage *pUsage;

  141497.   struct HiddenIndexInfo *pHidden;

  141498.   WhereTerm *pTerm;

  141499.   int nOrderBy;

  141500.   sqlite3_index_info *pIdxInfo;

  141501.   u16 mNoOmit = 0;

  141502. 

  141503.   /* Count the number of possible WHERE clause constraints referring

  141504.   ** to this virtual table */

  141505.   for(i=nTerm=0, pTerm=pWC->a; i<pWC->nTerm; i++, pTerm++){

  141506.     if( pTerm->leftCursor != pSrc->iCursor ) continue;

  141507.     if( pTerm->prereqRight & mUnusable ) continue;

  141508.     assert( IsPowerOfTwo(pTerm->eOperator & ~WO_EQUIV) );

  141509.     testcase( pTerm->eOperator & WO_IN );

  141510.     testcase( pTerm->eOperator & WO_ISNULL );

  141511.     testcase( pTerm->eOperator & WO_IS );

  141512.     testcase( pTerm->eOperator & WO_ALL );

  141513.     if( (pTerm->eOperator & ~(WO_EQUIV))==0 ) continue;

  141514.     if( pTerm->wtFlags & TERM_VNULL ) continue;

  141515.     assert( pTerm->u.leftColumn>=(-1) );

  141516.     nTerm++;

  141517.   }

  141518. 

  141519.   /* If the ORDER BY clause contains only columns in the current 

  141520.   ** virtual table then allocate space for the aOrderBy part of

  141521.   ** the sqlite3_index_info structure.

  141522.   */

  141523.   nOrderBy = 0;

  141524.   if( pOrderBy ){

  141525.     int n = pOrderBy->nExpr;

  141526.     for(i=0; i<n; i++){

  141527.       Expr *pExpr = pOrderBy->a[i].pExpr;

  141528.       if( pExpr->op!=TK_COLUMN || pExpr->iTable!=pSrc->iCursor ) break;

  141529.     }

  141530.     if( i==n){

  141531.       nOrderBy = n;

  141532.     }

  141533.   }

  141534. 

  141535.   /* Allocate the sqlite3_index_info structure

  141536.   */

  141537.   pIdxInfo = sqlite3DbMallocZero(pParse->db, sizeof(*pIdxInfo)

  141538.                            + (sizeof(*pIdxCons) + sizeof(*pUsage))*nTerm

  141539.                            + sizeof(*pIdxOrderBy)*nOrderBy + sizeof(*pHidden) );

  141540.   if( pIdxInfo==0 ){

  141541.     sqlite3ErrorMsg(pParse, "out of memory");

  141542.     return 0;

  141543.   }

  141544. 

  141545.   /* Initialize the structure.  The sqlite3_index_info structure contains

  141546.   ** many fields that are declared "const" to prevent xBestIndex from

  141547.   ** changing them.  We have to do some funky casting in order to

  141548.   ** initialize those fields.

  141549.   */

  141550.   pHidden = (struct HiddenIndexInfo*)&pIdxInfo[1];

  141551.   pIdxCons = (struct sqlite3_index_constraint*)&pHidden[1];

  141552.   pIdxOrderBy = (struct sqlite3_index_orderby*)&pIdxCons[nTerm];

  141553.   pUsage = (struct sqlite3_index_constraint_usage*)&pIdxOrderBy[nOrderBy];

  141554.   *(int*)&pIdxInfo->nConstraint = nTerm;

  141555.   *(int*)&pIdxInfo->nOrderBy = nOrderBy;

  141556.   *(struct sqlite3_index_constraint**)&pIdxInfo->aConstraint = pIdxCons;

  141557.   *(struct sqlite3_index_orderby**)&pIdxInfo->aOrderBy = pIdxOrderBy;

  141558.   *(struct sqlite3_index_constraint_usage**)&pIdxInfo->aConstraintUsage =

  141559.                                                                    pUsage;

  141560. 

  141561.   pHidden->pWC = pWC;

  141562.   pHidden->pParse = pParse;

  141563.   for(i=j=0, pTerm=pWC->a; i<pWC->nTerm; i++, pTerm++){

  141564.     u16 op;

  141565.     if( pTerm->leftCursor != pSrc->iCursor ) continue;

  141566.     if( pTerm->prereqRight & mUnusable ) continue;

  141567.     assert( IsPowerOfTwo(pTerm->eOperator & ~WO_EQUIV) );

  141568.     testcase( pTerm->eOperator & WO_IN );

  141569.     testcase( pTerm->eOperator & WO_IS );

  141570.     testcase( pTerm->eOperator & WO_ISNULL );

  141571.     testcase( pTerm->eOperator & WO_ALL );

  141572.     if( (pTerm->eOperator & ~(WO_EQUIV))==0 ) continue;

  141573.     if( pTerm->wtFlags & TERM_VNULL ) continue;

  141574.     if( (pSrc->fg.jointype & JT_LEFT)!=0

  141575.      && !ExprHasProperty(pTerm->pExpr, EP_FromJoin)

  141576.      && (pTerm->eOperator & (WO_IS|WO_ISNULL))

  141577.     ){

  141578.       /* An "IS" term in the WHERE clause where the virtual table is the rhs

  141579.       ** of a LEFT JOIN. Do not pass this term to the virtual table

  141580.       ** implementation, as this can lead to incorrect results from SQL such

  141581.       ** as:

  141582.       **

  141583.       **   "LEFT JOIN vtab WHERE vtab.col IS NULL"  */

  141584.       testcase( pTerm->eOperator & WO_ISNULL );

  141585.       testcase( pTerm->eOperator & WO_IS );

  141586.       continue;

  141587.     }

  141588.     assert( pTerm->u.leftColumn>=(-1) );

  141589.     pIdxCons[j].iColumn = pTerm->u.leftColumn;

  141590.     pIdxCons[j].iTermOffset = i;

  141591.     op = pTerm->eOperator & WO_ALL;

  141592.     if( op==WO_IN ) op = WO_EQ;

  141593.     if( op==WO_AUX ){

  141594.       pIdxCons[j].op = pTerm->eMatchOp;

  141595.     }else if( op & (WO_ISNULL|WO_IS) ){

  141596.       if( op==WO_ISNULL ){

  141597.         pIdxCons[j].op = SQLITE_INDEX_CONSTRAINT_ISNULL;

  141598.       }else{

  141599.         pIdxCons[j].op = SQLITE_INDEX_CONSTRAINT_IS;

  141600.       }

  141601.     }else{

  141602.       pIdxCons[j].op = (u8)op;

  141603.       /* The direct assignment in the previous line is possible only because

  141604.       ** the WO_ and SQLITE_INDEX_CONSTRAINT_ codes are identical.  The

  141605.       ** following asserts verify this fact. */

  141606.       assert( WO_EQ==SQLITE_INDEX_CONSTRAINT_EQ );

  141607.       assert( WO_LT==SQLITE_INDEX_CONSTRAINT_LT );

  141608.       assert( WO_LE==SQLITE_INDEX_CONSTRAINT_LE );

  141609.       assert( WO_GT==SQLITE_INDEX_CONSTRAINT_GT );

  141610.       assert( WO_GE==SQLITE_INDEX_CONSTRAINT_GE );

  141611.       assert( pTerm->eOperator&(WO_IN|WO_EQ|WO_LT|WO_LE|WO_GT|WO_GE|WO_AUX) );

  141612. 

  141613.       if( op & (WO_LT|WO_LE|WO_GT|WO_GE)

  141614.        && sqlite3ExprIsVector(pTerm->pExpr->pRight) 

  141615.       ){

  141616.         if( i<16 ) mNoOmit |= (1 << i);

  141617.         if( op==WO_LT ) pIdxCons[j].op = WO_LE;

  141618.         if( op==WO_GT ) pIdxCons[j].op = WO_GE;

  141619.       }

  141620.     }

  141621. 

  141622.     j++;

  141623.   }

  141624.   for(i=0; i<nOrderBy; i++){

  141625.     Expr *pExpr = pOrderBy->a[i].pExpr;

  141626.     pIdxOrderBy[i].iColumn = pExpr->iColumn;

  141627.     pIdxOrderBy[i].desc = pOrderBy->a[i].sortOrder;

  141628.   }

  141629. 

  141630.   *pmNoOmit = mNoOmit;

  141631.   return pIdxInfo;

  141632. }

  141633. 

  141634. /*

  141635. ** The table object reference passed as the second argument to this function

  141636. ** must represent a virtual table. This function invokes the xBestIndex()

  141637. ** method of the virtual table with the sqlite3_index_info object that

  141638. ** comes in as the 3rd argument to this function.

  141639. **

  141640. ** If an error occurs, pParse is populated with an error message and an

  141641. ** appropriate error code is returned.  A return of SQLITE_CONSTRAINT from

  141642. ** xBestIndex is not considered an error.  SQLITE_CONSTRAINT indicates that

  141643. ** the current configuration of "unusable" flags in sqlite3_index_info can

  141644. ** not result in a valid plan.

  141645. **

  141646. ** Whether or not an error is returned, it is the responsibility of the

  141647. ** caller to eventually free p->idxStr if p->needToFreeIdxStr indicates

  141648. ** that this is required.

  141649. */

  141650. static int vtabBestIndex(Parse *pParse, Table *pTab, sqlite3_index_info *p){

  141651.   sqlite3_vtab *pVtab = sqlite3GetVTable(pParse->db, pTab)->pVtab;

  141652.   int rc;

  141653. 

  141654.   TRACE_IDX_INPUTS(p);

  141655.   rc = pVtab->pModule->xBestIndex(pVtab, p);

  141656.   TRACE_IDX_OUTPUTS(p);

  141657. 

  141658.   if( rc!=SQLITE_OK && rc!=SQLITE_CONSTRAINT ){

  141659.     if( rc==SQLITE_NOMEM ){

  141660.       sqlite3OomFault(pParse->db);

  141661.     }else if( !pVtab->zErrMsg ){

  141662.       sqlite3ErrorMsg(pParse, "%s", sqlite3ErrStr(rc));

  141663.     }else{

  141664.       sqlite3ErrorMsg(pParse, "%s", pVtab->zErrMsg);

  141665.     }

  141666.   }

  141667.   sqlite3_free(pVtab->zErrMsg);

  141668.   pVtab->zErrMsg = 0;

  141669.   return rc;

  141670. }

  141671. #endif /* !defined(SQLITE_OMIT_VIRTUALTABLE) */

  141672. 

  141673. #ifdef SQLITE_ENABLE_STAT3_OR_STAT4

  141674. /*

  141675. ** Estimate the location of a particular key among all keys in an

  141676. ** index.  Store the results in aStat as follows:

  141677. **

  141678. **    aStat[0]      Est. number of rows less than pRec

  141679. **    aStat[1]      Est. number of rows equal to pRec

  141680. **

  141681. ** Return the index of the sample that is the smallest sample that

  141682. ** is greater than or equal to pRec. Note that this index is not an index

  141683. ** into the aSample[] array - it is an index into a virtual set of samples

  141684. ** based on the contents of aSample[] and the number of fields in record 

  141685. ** pRec. 

  141686. */

  141687. static int whereKeyStats(

  141688.   Parse *pParse,              /* Database connection */

  141689.   Index *pIdx,                /* Index to consider domain of */

  141690.   UnpackedRecord *pRec,       /* Vector of values to consider */

  141691.   int roundUp,                /* Round up if true.  Round down if false */

  141692.   tRowcnt *aStat              /* OUT: stats written here */

  141693. ){

  141694.   IndexSample *aSample = pIdx->aSample;

  141695.   int iCol;                   /* Index of required stats in anEq[] etc. */

  141696.   int i;                      /* Index of first sample >= pRec */

  141697.   int iSample;                /* Smallest sample larger than or equal to pRec */

  141698.   int iMin = 0;               /* Smallest sample not yet tested */

  141699.   int iTest;                  /* Next sample to test */

  141700.   int res;                    /* Result of comparison operation */

  141701.   int nField;                 /* Number of fields in pRec */

  141702.   tRowcnt iLower = 0;         /* anLt[] + anEq[] of largest sample pRec is > */

  141703. 

  141704. #ifndef SQLITE_DEBUG

  141705.   UNUSED_PARAMETER( pParse );

  141706. #endif

  141707.   assert( pRec!=0 );

  141708.   assert( pIdx->nSample>0 );

  141709.   assert( pRec->nField>0 && pRec->nField<=pIdx->nSampleCol );

  141710. 

  141711.   /* Do a binary search to find the first sample greater than or equal

  141712.   ** to pRec. If pRec contains a single field, the set of samples to search

  141713.   ** is simply the aSample[] array. If the samples in aSample[] contain more

  141714.   ** than one fields, all fields following the first are ignored.

  141715.   **

  141716.   ** If pRec contains N fields, where N is more than one, then as well as the

  141717.   ** samples in aSample[] (truncated to N fields), the search also has to

  141718.   ** consider prefixes of those samples. For example, if the set of samples

  141719.   ** in aSample is:

  141720.   **

  141721.   **     aSample[0] = (a, 5) 

  141722.   **     aSample[1] = (a, 10) 

  141723.   **     aSample[2] = (b, 5) 

  141724.   **     aSample[3] = (c, 100) 

  141725.   **     aSample[4] = (c, 105)

  141726.   **

  141727.   ** Then the search space should ideally be the samples above and the 

  141728.   ** unique prefixes [a], [b] and [c]. But since that is hard to organize, 

  141729.   ** the code actually searches this set:

  141730.   **

  141731.   **     0: (a) 

  141732.   **     1: (a, 5) 

  141733.   **     2: (a, 10) 

  141734.   **     3: (a, 10) 

  141735.   **     4: (b) 

  141736.   **     5: (b, 5) 

  141737.   **     6: (c) 

  141738.   **     7: (c, 100) 

  141739.   **     8: (c, 105)

  141740.   **     9: (c, 105)

  141741.   **

  141742.   ** For each sample in the aSample[] array, N samples are present in the

  141743.   ** effective sample array. In the above, samples 0 and 1 are based on 

  141744.   ** sample aSample[0]. Samples 2 and 3 on aSample[1] etc.

  141745.   **

  141746.   ** Often, sample i of each block of N effective samples has (i+1) fields.

  141747.   ** Except, each sample may be extended to ensure that it is greater than or

  141748.   ** equal to the previous sample in the array. For example, in the above, 

  141749.   ** sample 2 is the first sample of a block of N samples, so at first it 

  141750.   ** appears that it should be 1 field in size. However, that would make it 

  141751.   ** smaller than sample 1, so the binary search would not work. As a result, 

  141752.   ** it is extended to two fields. The duplicates that this creates do not 

  141753.   ** cause any problems.

  141754.   */

  141755.   nField = pRec->nField;

  141756.   iCol = 0;

  141757.   iSample = pIdx->nSample * nField;

  141758.   do{

  141759.     int iSamp;                    /* Index in aSample[] of test sample */

  141760.     int n;                        /* Number of fields in test sample */

  141761. 

  141762.     iTest = (iMin+iSample)/2;

  141763.     iSamp = iTest / nField;

  141764.     if( iSamp>0 ){

  141765.       /* The proposed effective sample is a prefix of sample aSample[iSamp].

  141766.       ** Specifically, the shortest prefix of at least (1 + iTest%nField) 

  141767.       ** fields that is greater than the previous effective sample.  */

  141768.       for(n=(iTest % nField) + 1; n<nField; n++){

  141769.         if( aSample[iSamp-1].anLt[n-1]!=aSample[iSamp].anLt[n-1] ) break;

  141770.       }

  141771.     }else{

  141772.       n = iTest + 1;

  141773.     }

  141774. 

  141775.     pRec->nField = n;

  141776.     res = sqlite3VdbeRecordCompare(aSample[iSamp].n, aSample[iSamp].p, pRec);

  141777.     if( res<0 ){

  141778.       iLower = aSample[iSamp].anLt[n-1] + aSample[iSamp].anEq[n-1];

  141779.       iMin = iTest+1;

  141780.     }else if( res==0 && n<nField ){

  141781.       iLower = aSample[iSamp].anLt[n-1];

  141782.       iMin = iTest+1;

  141783.       res = -1;

  141784.     }else{

  141785.       iSample = iTest;

  141786.       iCol = n-1;

  141787.     }

  141788.   }while( res && iMin<iSample );

  141789.   i = iSample / nField;

  141790. 

  141791. #ifdef SQLITE_DEBUG

  141792.   /* The following assert statements check that the binary search code

  141793.   ** above found the right answer. This block serves no purpose other

  141794.   ** than to invoke the asserts.  */

  141795.   if( pParse->db->mallocFailed==0 ){

  141796.     if( res==0 ){

  141797.       /* If (res==0) is true, then pRec must be equal to sample i. */

  141798.       assert( i<pIdx->nSample );

  141799.       assert( iCol==nField-1 );

  141800.       pRec->nField = nField;

  141801.       assert( 0==sqlite3VdbeRecordCompare(aSample[i].n, aSample[i].p, pRec) 

  141802.            || pParse->db->mallocFailed 

  141803.       );

  141804.     }else{

  141805.       /* Unless i==pIdx->nSample, indicating that pRec is larger than

  141806.       ** all samples in the aSample[] array, pRec must be smaller than the

  141807.       ** (iCol+1) field prefix of sample i.  */

  141808.       assert( i<=pIdx->nSample && i>=0 );

  141809.       pRec->nField = iCol+1;

  141810.       assert( i==pIdx->nSample 

  141811.            || sqlite3VdbeRecordCompare(aSample[i].n, aSample[i].p, pRec)>0

  141812.            || pParse->db->mallocFailed );

  141813. 

  141814.       /* if i==0 and iCol==0, then record pRec is smaller than all samples

  141815.       ** in the aSample[] array. Otherwise, if (iCol>0) then pRec must

  141816.       ** be greater than or equal to the (iCol) field prefix of sample i.

  141817.       ** If (i>0), then pRec must also be greater than sample (i-1).  */

  141818.       if( iCol>0 ){

  141819.         pRec->nField = iCol;

  141820.         assert( sqlite3VdbeRecordCompare(aSample[i].n, aSample[i].p, pRec)<=0

  141821.              || pParse->db->mallocFailed );

  141822.       }

  141823.       if( i>0 ){

  141824.         pRec->nField = nField;

  141825.         assert( sqlite3VdbeRecordCompare(aSample[i-1].n, aSample[i-1].p, pRec)<0

  141826.              || pParse->db->mallocFailed );

  141827.       }

  141828.     }

  141829.   }

  141830. #endif /* ifdef SQLITE_DEBUG */

  141831. 

  141832.   if( res==0 ){

  141833.     /* Record pRec is equal to sample i */

  141834.     assert( iCol==nField-1 );

  141835.     aStat[0] = aSample[i].anLt[iCol];

  141836.     aStat[1] = aSample[i].anEq[iCol];

  141837.   }else{

  141838.     /* At this point, the (iCol+1) field prefix of aSample[i] is the first 

  141839.     ** sample that is greater than pRec. Or, if i==pIdx->nSample then pRec

  141840.     ** is larger than all samples in the array. */

  141841.     tRowcnt iUpper, iGap;

  141842.     if( i>=pIdx->nSample ){

  141843.       iUpper = sqlite3LogEstToInt(pIdx->aiRowLogEst[0]);

  141844.     }else{

  141845.       iUpper = aSample[i].anLt[iCol];

  141846.     }

  141847. 

  141848.     if( iLower>=iUpper ){

  141849.       iGap = 0;

  141850.     }else{

  141851.       iGap = iUpper - iLower;

  141852.     }

  141853.     if( roundUp ){

  141854.       iGap = (iGap*2)/3;

  141855.     }else{

  141856.       iGap = iGap/3;

  141857.     }

  141858.     aStat[0] = iLower + iGap;

  141859.     aStat[1] = pIdx->aAvgEq[nField-1];

  141860.   }

  141861. 

  141862.   /* Restore the pRec->nField value before returning.  */

  141863.   pRec->nField = nField;

  141864.   return i;

  141865. }

  141866. #endif /* SQLITE_ENABLE_STAT3_OR_STAT4 */

  141867. 

  141868. /*

  141869. ** If it is not NULL, pTerm is a term that provides an upper or lower

  141870. ** bound on a range scan. Without considering pTerm, it is estimated 

  141871. ** that the scan will visit nNew rows. This function returns the number

  141872. ** estimated to be visited after taking pTerm into account.

  141873. **

  141874. ** If the user explicitly specified a likelihood() value for this term,

  141875. ** then the return value is the likelihood multiplied by the number of

  141876. ** input rows. Otherwise, this function assumes that an "IS NOT NULL" term

  141877. ** has a likelihood of 0.50, and any other term a likelihood of 0.25.

  141878. */

  141879. static LogEst whereRangeAdjust(WhereTerm *pTerm, LogEst nNew){

  141880.   LogEst nRet = nNew;

  141881.   if( pTerm ){

  141882.     if( pTerm->truthProb<=0 ){

  141883.       nRet += pTerm->truthProb;

  141884.     }else if( (pTerm->wtFlags & TERM_VNULL)==0 ){

  141885.       nRet -= 20;        assert( 20==sqlite3LogEst(4) );

  141886.     }

  141887.   }

  141888.   return nRet;

  141889. }

  141890. 

  141891. 

  141892. #ifdef SQLITE_ENABLE_STAT3_OR_STAT4

  141893. /*

  141894. ** Return the affinity for a single column of an index.

  141895. */

  141896. SQLITE_PRIVATE char sqlite3IndexColumnAffinity(sqlite3 *db, Index *pIdx, int iCol){

  141897.   assert( iCol>=0 && iCol<pIdx->nColumn );

  141898.   if( !pIdx->zColAff ){

  141899.     if( sqlite3IndexAffinityStr(db, pIdx)==0 ) return SQLITE_AFF_BLOB;

  141900.   }

  141901.   return pIdx->zColAff[iCol];

  141902. }

  141903. #endif

  141904. 

  141905. 

  141906. #ifdef SQLITE_ENABLE_STAT3_OR_STAT4

  141907. /* 

  141908. ** This function is called to estimate the number of rows visited by a

  141909. ** range-scan on a skip-scan index. For example:

  141910. **

  141911. **   CREATE INDEX i1 ON t1(a, b, c);

  141912. **   SELECT * FROM t1 WHERE a=? AND c BETWEEN ? AND ?;

  141913. **

  141914. ** Value pLoop->nOut is currently set to the estimated number of rows 

  141915. ** visited for scanning (a=? AND b=?). This function reduces that estimate 

  141916. ** by some factor to account for the (c BETWEEN ? AND ?) expression based

  141917. ** on the stat4 data for the index. this scan will be peformed multiple 

  141918. ** times (once for each (a,b) combination that matches a=?) is dealt with 

  141919. ** by the caller.

  141920. **

  141921. ** It does this by scanning through all stat4 samples, comparing values

  141922. ** extracted from pLower and pUpper with the corresponding column in each

  141923. ** sample. If L and U are the number of samples found to be less than or

  141924. ** equal to the values extracted from pLower and pUpper respectively, and

  141925. ** N is the total number of samples, the pLoop->nOut value is adjusted

  141926. ** as follows:

  141927. **

  141928. **   nOut = nOut * ( min(U - L, 1) / N )

  141929. **

  141930. ** If pLower is NULL, or a value cannot be extracted from the term, L is

  141931. ** set to zero. If pUpper is NULL, or a value cannot be extracted from it,

  141932. ** U is set to N.

  141933. **

  141934. ** Normally, this function sets *pbDone to 1 before returning. However,

  141935. ** if no value can be extracted from either pLower or pUpper (and so the

  141936. ** estimate of the number of rows delivered remains unchanged), *pbDone

  141937. ** is left as is.

  141938. **

  141939. ** If an error occurs, an SQLite error code is returned. Otherwise, 

  141940. ** SQLITE_OK.

  141941. */

  141942. static int whereRangeSkipScanEst(

  141943.   Parse *pParse,       /* Parsing & code generating context */

  141944.   WhereTerm *pLower,   /* Lower bound on the range. ex: "x>123" Might be NULL */

  141945.   WhereTerm *pUpper,   /* Upper bound on the range. ex: "x<455" Might be NULL */

  141946.   WhereLoop *pLoop,    /* Update the .nOut value of this loop */

  141947.   int *pbDone          /* Set to true if at least one expr. value extracted */

  141948. ){

  141949.   Index *p = pLoop->u.btree.pIndex;

  141950.   int nEq = pLoop->u.btree.nEq;

  141951.   sqlite3 *db = pParse->db;

  141952.   int nLower = -1;

  141953.   int nUpper = p->nSample+1;

  141954.   int rc = SQLITE_OK;

  141955.   u8 aff = sqlite3IndexColumnAffinity(db, p, nEq);

  141956.   CollSeq *pColl;

  141957.   

  141958.   sqlite3_value *p1 = 0;          /* Value extracted from pLower */

  141959.   sqlite3_value *p2 = 0;          /* Value extracted from pUpper */

  141960.   sqlite3_value *pVal = 0;        /* Value extracted from record */

  141961. 

  141962.   pColl = sqlite3LocateCollSeq(pParse, p->azColl[nEq]);

  141963.   if( pLower ){

  141964.     rc = sqlite3Stat4ValueFromExpr(pParse, pLower->pExpr->pRight, aff, &p1);

  141965.     nLower = 0;

  141966.   }

  141967.   if( pUpper && rc==SQLITE_OK ){

  141968.     rc = sqlite3Stat4ValueFromExpr(pParse, pUpper->pExpr->pRight, aff, &p2);

  141969.     nUpper = p2 ? 0 : p->nSample;

  141970.   }

  141971. 

  141972.   if( p1 || p2 ){

  141973.     int i;

  141974.     int nDiff;

  141975.     for(i=0; rc==SQLITE_OK && i<p->nSample; i++){

  141976.       rc = sqlite3Stat4Column(db, p->aSample[i].p, p->aSample[i].n, nEq, &pVal);

  141977.       if( rc==SQLITE_OK && p1 ){

  141978.         int res = sqlite3MemCompare(p1, pVal, pColl);

  141979.         if( res>=0 ) nLower++;

  141980.       }

  141981.       if( rc==SQLITE_OK && p2 ){

  141982.         int res = sqlite3MemCompare(p2, pVal, pColl);

  141983.         if( res>=0 ) nUpper++;

  141984.       }

  141985.     }

  141986.     nDiff = (nUpper - nLower);

  141987.     if( nDiff<=0 ) nDiff = 1;

  141988. 

  141989.     /* If there is both an upper and lower bound specified, and the 

  141990.     ** comparisons indicate that they are close together, use the fallback

  141991.     ** method (assume that the scan visits 1/64 of the rows) for estimating

  141992.     ** the number of rows visited. Otherwise, estimate the number of rows

  141993.     ** using the method described in the header comment for this function. */

  141994.     if( nDiff!=1 || pUpper==0 || pLower==0 ){

  141995.       int nAdjust = (sqlite3LogEst(p->nSample) - sqlite3LogEst(nDiff));

  141996.       pLoop->nOut -= nAdjust;

  141997.       *pbDone = 1;

  141998.       WHERETRACE(0x10, ("range skip-scan regions: %u..%u  adjust=%d est=%d\n",

  141999.                            nLower, nUpper, nAdjust*-1, pLoop->nOut));

  142000.     }

  142001. 

  142002.   }else{

  142003.     assert( *pbDone==0 );

  142004.   }

  142005. 

  142006.   sqlite3ValueFree(p1);

  142007.   sqlite3ValueFree(p2);

  142008.   sqlite3ValueFree(pVal);

  142009. 

  142010.   return rc;

  142011. }

  142012. #endif /* SQLITE_ENABLE_STAT3_OR_STAT4 */

  142013. 

  142014. /*

  142015. ** This function is used to estimate the number of rows that will be visited

  142016. ** by scanning an index for a range of values. The range may have an upper

  142017. ** bound, a lower bound, or both. The WHERE clause terms that set the upper

  142018. ** and lower bounds are represented by pLower and pUpper respectively. For

  142019. ** example, assuming that index p is on t1(a):

  142020. **

  142021. **   ... FROM t1 WHERE a > ? AND a < ? ...

  142022. **                    |_____|   |_____|

  142023. **                       |         |

  142024. **                     pLower    pUpper

  142025. **

  142026. ** If either of the upper or lower bound is not present, then NULL is passed in

  142027. ** place of the corresponding WhereTerm.

  142028. **

  142029. ** The value in (pBuilder->pNew->u.btree.nEq) is the number of the index

  142030. ** column subject to the range constraint. Or, equivalently, the number of

  142031. ** equality constraints optimized by the proposed index scan. For example,

  142032. ** assuming index p is on t1(a, b), and the SQL query is:

  142033. **

  142034. **   ... FROM t1 WHERE a = ? AND b > ? AND b < ? ...

  142035. **

  142036. ** then nEq is set to 1 (as the range restricted column, b, is the second 

  142037. ** left-most column of the index). Or, if the query is:

  142038. **

  142039. **   ... FROM t1 WHERE a > ? AND a < ? ...

  142040. **

  142041. ** then nEq is set to 0.

  142042. **

  142043. ** When this function is called, *pnOut is set to the sqlite3LogEst() of the

  142044. ** number of rows that the index scan is expected to visit without 

  142045. ** considering the range constraints. If nEq is 0, then *pnOut is the number of 

  142046. ** rows in the index. Assuming no error occurs, *pnOut is adjusted (reduced)

  142047. ** to account for the range constraints pLower and pUpper.

  142048. ** 

  142049. ** In the absence of sqlite_stat4 ANALYZE data, or if such data cannot be

  142050. ** used, a single range inequality reduces the search space by a factor of 4. 

  142051. ** and a pair of constraints (x>? AND x<?) reduces the expected number of

  142052. ** rows visited by a factor of 64.

  142053. */

  142054. static int whereRangeScanEst(

  142055.   Parse *pParse,       /* Parsing & code generating context */

  142056.   WhereLoopBuilder *pBuilder,

  142057.   WhereTerm *pLower,   /* Lower bound on the range. ex: "x>123" Might be NULL */

  142058.   WhereTerm *pUpper,   /* Upper bound on the range. ex: "x<455" Might be NULL */

  142059.   WhereLoop *pLoop     /* Modify the .nOut and maybe .rRun fields */

  142060. ){

  142061.   int rc = SQLITE_OK;

  142062.   int nOut = pLoop->nOut;

  142063.   LogEst nNew;

  142064. 

  142065. #ifdef SQLITE_ENABLE_STAT3_OR_STAT4

  142066.   Index *p = pLoop->u.btree.pIndex;

  142067.   int nEq = pLoop->u.btree.nEq;

  142068. 

  142069.   if( p->nSample>0 && nEq<p->nSampleCol

  142070.    && OptimizationEnabled(pParse->db, SQLITE_Stat34)

  142071.   ){

  142072.     if( nEq==pBuilder->nRecValid ){

  142073.       UnpackedRecord *pRec = pBuilder->pRec;

  142074.       tRowcnt a[2];

  142075.       int nBtm = pLoop->u.btree.nBtm;

  142076.       int nTop = pLoop->u.btree.nTop;

  142077. 

  142078.       /* Variable iLower will be set to the estimate of the number of rows in 

  142079.       ** the index that are less than the lower bound of the range query. The

  142080.       ** lower bound being the concatenation of $P and $L, where $P is the

  142081.       ** key-prefix formed by the nEq values matched against the nEq left-most

  142082.       ** columns of the index, and $L is the value in pLower.

  142083.       **

  142084.       ** Or, if pLower is NULL or $L cannot be extracted from it (because it

  142085.       ** is not a simple variable or literal value), the lower bound of the

  142086.       ** range is $P. Due to a quirk in the way whereKeyStats() works, even

  142087.       ** if $L is available, whereKeyStats() is called for both ($P) and 

  142088.       ** ($P:$L) and the larger of the two returned values is used.

  142089.       **

  142090.       ** Similarly, iUpper is to be set to the estimate of the number of rows

  142091.       ** less than the upper bound of the range query. Where the upper bound

  142092.       ** is either ($P) or ($P:$U). Again, even if $U is available, both values

  142093.       ** of iUpper are requested of whereKeyStats() and the smaller used.

  142094.       **

  142095.       ** The number of rows between the two bounds is then just iUpper-iLower.

  142096.       */

  142097.       tRowcnt iLower;     /* Rows less than the lower bound */

  142098.       tRowcnt iUpper;     /* Rows less than the upper bound */

  142099.       int iLwrIdx = -2;   /* aSample[] for the lower bound */

  142100.       int iUprIdx = -1;   /* aSample[] for the upper bound */

  142101. 

  142102.       if( pRec ){

  142103.         testcase( pRec->nField!=pBuilder->nRecValid );

  142104.         pRec->nField = pBuilder->nRecValid;

  142105.       }

  142106.       /* Determine iLower and iUpper using ($P) only. */

  142107.       if( nEq==0 ){

  142108.         iLower = 0;

  142109.         iUpper = p->nRowEst0;

  142110.       }else{

  142111.         /* Note: this call could be optimized away - since the same values must 

  142112.         ** have been requested when testing key $P in whereEqualScanEst().  */

  142113.         whereKeyStats(pParse, p, pRec, 0, a);

  142114.         iLower = a[0];

  142115.         iUpper = a[0] + a[1];

  142116.       }

  142117. 

  142118.       assert( pLower==0 || (pLower->eOperator & (WO_GT|WO_GE))!=0 );

  142119.       assert( pUpper==0 || (pUpper->eOperator & (WO_LT|WO_LE))!=0 );

  142120.       assert( p->aSortOrder!=0 );

  142121.       if( p->aSortOrder[nEq] ){

  142122.         /* The roles of pLower and pUpper are swapped for a DESC index */

  142123.         SWAP(WhereTerm*, pLower, pUpper);

  142124.         SWAP(int, nBtm, nTop);

  142125.       }

  142126. 

  142127.       /* If possible, improve on the iLower estimate using ($P:$L). */

  142128.       if( pLower ){

  142129.         int n;                    /* Values extracted from pExpr */

  142130.         Expr *pExpr = pLower->pExpr->pRight;

  142131.         rc = sqlite3Stat4ProbeSetValue(pParse, p, &pRec, pExpr, nBtm, nEq, &n);

  142132.         if( rc==SQLITE_OK && n ){

  142133.           tRowcnt iNew;

  142134.           u16 mask = WO_GT|WO_LE;

  142135.           if( sqlite3ExprVectorSize(pExpr)>n ) mask = (WO_LE|WO_LT);

  142136.           iLwrIdx = whereKeyStats(pParse, p, pRec, 0, a);

  142137.           iNew = a[0] + ((pLower->eOperator & mask) ? a[1] : 0);

  142138.           if( iNew>iLower ) iLower = iNew;

  142139.           nOut--;

  142140.           pLower = 0;

  142141.         }

  142142.       }

  142143. 

  142144.       /* If possible, improve on the iUpper estimate using ($P:$U). */

  142145.       if( pUpper ){

  142146.         int n;                    /* Values extracted from pExpr */

  142147.         Expr *pExpr = pUpper->pExpr->pRight;

  142148.         rc = sqlite3Stat4ProbeSetValue(pParse, p, &pRec, pExpr, nTop, nEq, &n);

  142149.         if( rc==SQLITE_OK && n ){

  142150.           tRowcnt iNew;

  142151.           u16 mask = WO_GT|WO_LE;

  142152.           if( sqlite3ExprVectorSize(pExpr)>n ) mask = (WO_LE|WO_LT);

  142153.           iUprIdx = whereKeyStats(pParse, p, pRec, 1, a);

  142154.           iNew = a[0] + ((pUpper->eOperator & mask) ? a[1] : 0);

  142155.           if( iNew<iUpper ) iUpper = iNew;

  142156.           nOut--;

  142157.           pUpper = 0;

  142158.         }

  142159.       }

  142160. 

  142161.       pBuilder->pRec = pRec;

  142162.       if( rc==SQLITE_OK ){

  142163.         if( iUpper>iLower ){

  142164.           nNew = sqlite3LogEst(iUpper - iLower);

  142165.           /* TUNING:  If both iUpper and iLower are derived from the same

  142166.           ** sample, then assume they are 4x more selective.  This brings

  142167.           ** the estimated selectivity more in line with what it would be

  142168.           ** if estimated without the use of STAT3/4 tables. */

  142169.           if( iLwrIdx==iUprIdx ) nNew -= 20;  assert( 20==sqlite3LogEst(4) );

  142170.         }else{

  142171.           nNew = 10;        assert( 10==sqlite3LogEst(2) );

  142172.         }

  142173.         if( nNew<nOut ){

  142174.           nOut = nNew;

  142175.         }

  142176.         WHERETRACE(0x10, ("STAT4 range scan: %u..%u  est=%d\n",

  142177.                            (u32)iLower, (u32)iUpper, nOut));

  142178.       }

  142179.     }else{

  142180.       int bDone = 0;

  142181.       rc = whereRangeSkipScanEst(pParse, pLower, pUpper, pLoop, &bDone);

  142182.       if( bDone ) return rc;

  142183.     }

  142184.   }

  142185. #else

  142186.   UNUSED_PARAMETER(pParse);

  142187.   UNUSED_PARAMETER(pBuilder);

  142188.   assert( pLower || pUpper );

  142189. #endif

  142190.   assert( pUpper==0 || (pUpper->wtFlags & TERM_VNULL)==0 );

  142191.   nNew = whereRangeAdjust(pLower, nOut);

  142192.   nNew = whereRangeAdjust(pUpper, nNew);

  142193. 

  142194.   /* TUNING: If there is both an upper and lower limit and neither limit

  142195.   ** has an application-defined likelihood(), assume the range is

  142196.   ** reduced by an additional 75%. This means that, by default, an open-ended

  142197.   ** range query (e.g. col > ?) is assumed to match 1/4 of the rows in the

  142198.   ** index. While a closed range (e.g. col BETWEEN ? AND ?) is estimated to

  142199.   ** match 1/64 of the index. */ 

  142200.   if( pLower && pLower->truthProb>0 && pUpper && pUpper->truthProb>0 ){

  142201.     nNew -= 20;

  142202.   }

  142203. 

  142204.   nOut -= (pLower!=0) + (pUpper!=0);

  142205.   if( nNew<10 ) nNew = 10;

  142206.   if( nNew<nOut ) nOut = nNew;

  142207. #if defined(WHERETRACE_ENABLED)

  142208.   if( pLoop->nOut>nOut ){

  142209.     WHERETRACE(0x10,("Range scan lowers nOut from %d to %d\n",

  142210.                     pLoop->nOut, nOut));

  142211.   }

  142212. #endif

  142213.   pLoop->nOut = (LogEst)nOut;

  142214.   return rc;

  142215. }

  142216. 

  142217. #ifdef SQLITE_ENABLE_STAT3_OR_STAT4

  142218. /*

  142219. ** Estimate the number of rows that will be returned based on

  142220. ** an equality constraint x=VALUE and where that VALUE occurs in

  142221. ** the histogram data.  This only works when x is the left-most

  142222. ** column of an index and sqlite_stat3 histogram data is available

  142223. ** for that index.  When pExpr==NULL that means the constraint is

  142224. ** "x IS NULL" instead of "x=VALUE".

  142225. **

  142226. ** Write the estimated row count into *pnRow and return SQLITE_OK. 

  142227. ** If unable to make an estimate, leave *pnRow unchanged and return

  142228. ** non-zero.

  142229. **

  142230. ** This routine can fail if it is unable to load a collating sequence

  142231. ** required for string comparison, or if unable to allocate memory

  142232. ** for a UTF conversion required for comparison.  The error is stored

  142233. ** in the pParse structure.

  142234. */

  142235. static int whereEqualScanEst(

  142236.   Parse *pParse,       /* Parsing & code generating context */

  142237.   WhereLoopBuilder *pBuilder,

  142238.   Expr *pExpr,         /* Expression for VALUE in the x=VALUE constraint */

  142239.   tRowcnt *pnRow       /* Write the revised row estimate here */

  142240. ){

  142241.   Index *p = pBuilder->pNew->u.btree.pIndex;

  142242.   int nEq = pBuilder->pNew->u.btree.nEq;

  142243.   UnpackedRecord *pRec = pBuilder->pRec;

  142244.   int rc;                   /* Subfunction return code */

  142245.   tRowcnt a[2];             /* Statistics */

  142246.   int bOk;

  142247. 

  142248.   assert( nEq>=1 );

  142249.   assert( nEq<=p->nColumn );

  142250.   assert( p->aSample!=0 );

  142251.   assert( p->nSample>0 );

  142252.   assert( pBuilder->nRecValid<nEq );

  142253. 

  142254.   /* If values are not available for all fields of the index to the left

  142255.   ** of this one, no estimate can be made. Return SQLITE_NOTFOUND. */

  142256.   if( pBuilder->nRecValid<(nEq-1) ){

  142257.     return SQLITE_NOTFOUND;

  142258.   }

  142259. 

  142260.   /* This is an optimization only. The call to sqlite3Stat4ProbeSetValue()

  142261.   ** below would return the same value.  */

  142262.   if( nEq>=p->nColumn ){

  142263.     *pnRow = 1;

  142264.     return SQLITE_OK;

  142265.   }

  142266. 

  142267.   rc = sqlite3Stat4ProbeSetValue(pParse, p, &pRec, pExpr, 1, nEq-1, &bOk);

  142268.   pBuilder->pRec = pRec;

  142269.   if( rc!=SQLITE_OK ) return rc;

  142270.   if( bOk==0 ) return SQLITE_NOTFOUND;

  142271.   pBuilder->nRecValid = nEq;

  142272. 

  142273.   whereKeyStats(pParse, p, pRec, 0, a);

  142274.   WHERETRACE(0x10,("equality scan regions %s(%d): %d\n",

  142275.                    p->zName, nEq-1, (int)a[1]));

  142276.   *pnRow = a[1];

  142277.   

  142278.   return rc;

  142279. }

  142280. #endif /* SQLITE_ENABLE_STAT3_OR_STAT4 */

  142281. 

  142282. #ifdef SQLITE_ENABLE_STAT3_OR_STAT4

  142283. /*

  142284. ** Estimate the number of rows that will be returned based on

  142285. ** an IN constraint where the right-hand side of the IN operator

  142286. ** is a list of values.  Example:

  142287. **

  142288. **        WHERE x IN (1,2,3,4)

  142289. **

  142290. ** Write the estimated row count into *pnRow and return SQLITE_OK. 

  142291. ** If unable to make an estimate, leave *pnRow unchanged and return

  142292. ** non-zero.

  142293. **

  142294. ** This routine can fail if it is unable to load a collating sequence

  142295. ** required for string comparison, or if unable to allocate memory

  142296. ** for a UTF conversion required for comparison.  The error is stored

  142297. ** in the pParse structure.

  142298. */

  142299. static int whereInScanEst(

  142300.   Parse *pParse,       /* Parsing & code generating context */

  142301.   WhereLoopBuilder *pBuilder,

  142302.   ExprList *pList,     /* The value list on the RHS of "x IN (v1,v2,v3,...)" */

  142303.   tRowcnt *pnRow       /* Write the revised row estimate here */

  142304. ){

  142305.   Index *p = pBuilder->pNew->u.btree.pIndex;

  142306.   i64 nRow0 = sqlite3LogEstToInt(p->aiRowLogEst[0]);

  142307.   int nRecValid = pBuilder->nRecValid;

  142308.   int rc = SQLITE_OK;     /* Subfunction return code */

  142309.   tRowcnt nEst;           /* Number of rows for a single term */

  142310.   tRowcnt nRowEst = 0;    /* New estimate of the number of rows */

  142311.   int i;                  /* Loop counter */

  142312. 

  142313.   assert( p->aSample!=0 );

  142314.   for(i=0; rc==SQLITE_OK && i<pList->nExpr; i++){

  142315.     nEst = nRow0;

  142316.     rc = whereEqualScanEst(pParse, pBuilder, pList->a[i].pExpr, &nEst);

  142317.     nRowEst += nEst;

  142318.     pBuilder->nRecValid = nRecValid;

  142319.   }

  142320. 

  142321.   if( rc==SQLITE_OK ){

  142322.     if( nRowEst > nRow0 ) nRowEst = nRow0;

  142323.     *pnRow = nRowEst;

  142324.     WHERETRACE(0x10,("IN row estimate: est=%d\n", nRowEst));

  142325.   }

  142326.   assert( pBuilder->nRecValid==nRecValid );

  142327.   return rc;

  142328. }

  142329. #endif /* SQLITE_ENABLE_STAT3_OR_STAT4 */

  142330. 

  142331. 

  142332. #ifdef WHERETRACE_ENABLED

  142333. /*

  142334. ** Print the content of a WhereTerm object

  142335. */

  142336. static void whereTermPrint(WhereTerm *pTerm, int iTerm){

  142337.   if( pTerm==0 ){

  142338.     sqlite3DebugPrintf("TERM-%-3d NULL\n", iTerm);

  142339.   }else{

  142340.     char zType[4];

  142341.     char zLeft[50];

  142342.     memcpy(zType, "...", 4);

  142343.     if( pTerm->wtFlags & TERM_VIRTUAL ) zType[0] = 'V';

  142344.     if( pTerm->eOperator & WO_EQUIV  ) zType[1] = 'E';

  142345.     if( ExprHasProperty(pTerm->pExpr, EP_FromJoin) ) zType[2] = 'L';

  142346.     if( pTerm->eOperator & WO_SINGLE ){

  142347.       sqlite3_snprintf(sizeof(zLeft),zLeft,"left={%d:%d}",

  142348.                        pTerm->leftCursor, pTerm->u.leftColumn);

  142349.     }else if( (pTerm->eOperator & WO_OR)!=0 && pTerm->u.pOrInfo!=0 ){

  142350.       sqlite3_snprintf(sizeof(zLeft),zLeft,"indexable=0x%lld", 

  142351.                        pTerm->u.pOrInfo->indexable);

  142352.     }else{

  142353.       sqlite3_snprintf(sizeof(zLeft),zLeft,"left=%d", pTerm->leftCursor);

  142354.     }

  142355.     sqlite3DebugPrintf(

  142356.        "TERM-%-3d %p %s %-12s prob=%-3d op=0x%03x wtFlags=0x%04x",

  142357.        iTerm, pTerm, zType, zLeft, pTerm->truthProb,

  142358.        pTerm->eOperator, pTerm->wtFlags);

  142359.     if( pTerm->iField ){

  142360.       sqlite3DebugPrintf(" iField=%d\n", pTerm->iField);

  142361.     }else{

  142362.       sqlite3DebugPrintf("\n");

  142363.     }

  142364.     sqlite3TreeViewExpr(0, pTerm->pExpr, 0);

  142365.   }

  142366. }

  142367. #endif

  142368. 

  142369. #ifdef WHERETRACE_ENABLED

  142370. /*

  142371. ** Show the complete content of a WhereClause

  142372. */

  142373. SQLITE_PRIVATE void sqlite3WhereClausePrint(WhereClause *pWC){

  142374.   int i;

  142375.   for(i=0; i<pWC->nTerm; i++){

  142376.     whereTermPrint(&pWC->a[i], i);

  142377.   }

  142378. }

  142379. #endif

  142380. 

  142381. #ifdef WHERETRACE_ENABLED

  142382. /*

  142383. ** Print a WhereLoop object for debugging purposes

  142384. */

  142385. static void whereLoopPrint(WhereLoop *p, WhereClause *pWC){

  142386.   WhereInfo *pWInfo = pWC->pWInfo;

  142387.   int nb = 1+(pWInfo->pTabList->nSrc+3)/4;

  142388.   struct SrcList_item *pItem = pWInfo->pTabList->a + p->iTab;

  142389.   Table *pTab = pItem->pTab;

  142390.   Bitmask mAll = (((Bitmask)1)<<(nb*4)) - 1;

  142391.   sqlite3DebugPrintf("%c%2d.%0*llx.%0*llx", p->cId,

  142392.                      p->iTab, nb, p->maskSelf, nb, p->prereq & mAll);

  142393.   sqlite3DebugPrintf(" %12s",

  142394.                      pItem->zAlias ? pItem->zAlias : pTab->zName);

  142395.   if( (p->wsFlags & WHERE_VIRTUALTABLE)==0 ){

  142396.     const char *zName;

  142397.     if( p->u.btree.pIndex && (zName = p->u.btree.pIndex->zName)!=0 ){

  142398.       if( strncmp(zName, "sqlite_autoindex_", 17)==0 ){

  142399.         int i = sqlite3Strlen30(zName) - 1;

  142400.         while( zName[i]!='_' ) i--;

  142401.         zName += i;

  142402.       }

  142403.       sqlite3DebugPrintf(".%-16s %2d", zName, p->u.btree.nEq);

  142404.     }else{

  142405.       sqlite3DebugPrintf("%20s","");

  142406.     }

  142407.   }else{

  142408.     char *z;

  142409.     if( p->u.vtab.idxStr ){

  142410.       z = sqlite3_mprintf("(%d,\"%s\",%x)",

  142411.                 p->u.vtab.idxNum, p->u.vtab.idxStr, p->u.vtab.omitMask);

  142412.     }else{

  142413.       z = sqlite3_mprintf("(%d,%x)", p->u.vtab.idxNum, p->u.vtab.omitMask);

  142414.     }

  142415.     sqlite3DebugPrintf(" %-19s", z);

  142416.     sqlite3_free(z);

  142417.   }

  142418.   if( p->wsFlags & WHERE_SKIPSCAN ){

  142419.     sqlite3DebugPrintf(" f %05x %d-%d", p->wsFlags, p->nLTerm,p->nSkip);

  142420.   }else{

  142421.     sqlite3DebugPrintf(" f %05x N %d", p->wsFlags, p->nLTerm);

  142422.   }

  142423.   sqlite3DebugPrintf(" cost %d,%d,%d\n", p->rSetup, p->rRun, p->nOut);

  142424.   if( p->nLTerm && (sqlite3WhereTrace & 0x100)!=0 ){

  142425.     int i;

  142426.     for(i=0; i<p->nLTerm; i++){

  142427.       whereTermPrint(p->aLTerm[i], i);

  142428.     }

  142429.   }

  142430. }

  142431. #endif

  142432. 

  142433. /*

  142434. ** Convert bulk memory into a valid WhereLoop that can be passed

  142435. ** to whereLoopClear harmlessly.

  142436. */

  142437. static void whereLoopInit(WhereLoop *p){

  142438.   p->aLTerm = p->aLTermSpace;

  142439.   p->nLTerm = 0;

  142440.   p->nLSlot = ArraySize(p->aLTermSpace);

  142441.   p->wsFlags = 0;

  142442. }

  142443. 

  142444. /*

  142445. ** Clear the WhereLoop.u union.  Leave WhereLoop.pLTerm intact.

  142446. */

  142447. static void whereLoopClearUnion(sqlite3 *db, WhereLoop *p){

  142448.   if( p->wsFlags & (WHERE_VIRTUALTABLE|WHERE_AUTO_INDEX) ){

  142449.     if( (p->wsFlags & WHERE_VIRTUALTABLE)!=0 && p->u.vtab.needFree ){

  142450.       sqlite3_free(p->u.vtab.idxStr);

  142451.       p->u.vtab.needFree = 0;

  142452.       p->u.vtab.idxStr = 0;

  142453.     }else if( (p->wsFlags & WHERE_AUTO_INDEX)!=0 && p->u.btree.pIndex!=0 ){

  142454.       sqlite3DbFree(db, p->u.btree.pIndex->zColAff);

  142455.       sqlite3DbFreeNN(db, p->u.btree.pIndex);

  142456.       p->u.btree.pIndex = 0;

  142457.     }

  142458.   }

  142459. }

  142460. 

  142461. /*

  142462. ** Deallocate internal memory used by a WhereLoop object

  142463. */

  142464. static void whereLoopClear(sqlite3 *db, WhereLoop *p){

  142465.   if( p->aLTerm!=p->aLTermSpace ) sqlite3DbFreeNN(db, p->aLTerm);

  142466.   whereLoopClearUnion(db, p);

  142467.   whereLoopInit(p);

  142468. }

  142469. 

  142470. /*

  142471. ** Increase the memory allocation for pLoop->aLTerm[] to be at least n.

  142472. */

  142473. static int whereLoopResize(sqlite3 *db, WhereLoop *p, int n){

  142474.   WhereTerm **paNew;

  142475.   if( p->nLSlot>=n ) return SQLITE_OK;

  142476.   n = (n+7)&~7;

  142477.   paNew = sqlite3DbMallocRawNN(db, sizeof(p->aLTerm[0])*n);

  142478.   if( paNew==0 ) return SQLITE_NOMEM_BKPT;

  142479.   memcpy(paNew, p->aLTerm, sizeof(p->aLTerm[0])*p->nLSlot);

  142480.   if( p->aLTerm!=p->aLTermSpace ) sqlite3DbFreeNN(db, p->aLTerm);

  142481.   p->aLTerm = paNew;

  142482.   p->nLSlot = n;

  142483.   return SQLITE_OK;

  142484. }

  142485. 

  142486. /*

  142487. ** Transfer content from the second pLoop into the first.

  142488. */

  142489. static int whereLoopXfer(sqlite3 *db, WhereLoop *pTo, WhereLoop *pFrom){

  142490.   whereLoopClearUnion(db, pTo);

  142491.   if( whereLoopResize(db, pTo, pFrom->nLTerm) ){

  142492.     memset(&pTo->u, 0, sizeof(pTo->u));

  142493.     return SQLITE_NOMEM_BKPT;

  142494.   }

  142495.   memcpy(pTo, pFrom, WHERE_LOOP_XFER_SZ);

  142496.   memcpy(pTo->aLTerm, pFrom->aLTerm, pTo->nLTerm*sizeof(pTo->aLTerm[0]));

  142497.   if( pFrom->wsFlags & WHERE_VIRTUALTABLE ){

  142498.     pFrom->u.vtab.needFree = 0;

  142499.   }else if( (pFrom->wsFlags & WHERE_AUTO_INDEX)!=0 ){

  142500.     pFrom->u.btree.pIndex = 0;

  142501.   }

  142502.   return SQLITE_OK;

  142503. }

  142504. 

  142505. /*

  142506. ** Delete a WhereLoop object

  142507. */

  142508. static void whereLoopDelete(sqlite3 *db, WhereLoop *p){

  142509.   whereLoopClear(db, p);

  142510.   sqlite3DbFreeNN(db, p);

  142511. }

  142512. 

  142513. /*

  142514. ** Free a WhereInfo structure

  142515. */

  142516. static void whereInfoFree(sqlite3 *db, WhereInfo *pWInfo){

  142517.   int i;

  142518.   assert( pWInfo!=0 );

  142519.   for(i=0; i<pWInfo->nLevel; i++){

  142520.     WhereLevel *pLevel = &pWInfo->a[i];

  142521.     if( pLevel->pWLoop && (pLevel->pWLoop->wsFlags & WHERE_IN_ABLE) ){

  142522.       sqlite3DbFree(db, pLevel->u.in.aInLoop);

  142523.     }

  142524.   }

  142525.   sqlite3WhereClauseClear(&pWInfo->sWC);

  142526.   while( pWInfo->pLoops ){

  142527.     WhereLoop *p = pWInfo->pLoops;

  142528.     pWInfo->pLoops = p->pNextLoop;

  142529.     whereLoopDelete(db, p);

  142530.   }

  142531.   sqlite3DbFreeNN(db, pWInfo);

  142532. }

  142533. 

  142534. /*

  142535. ** Return TRUE if all of the following are true:

  142536. **

  142537. **   (1)  X has the same or lower cost that Y

  142538. **   (2)  X uses fewer WHERE clause terms than Y

  142539. **   (3)  Every WHERE clause term used by X is also used by Y

  142540. **   (4)  X skips at least as many columns as Y

  142541. **   (5)  If X is a covering index, than Y is too

  142542. **

  142543. ** Conditions (2) and (3) mean that X is a "proper subset" of Y.

  142544. ** If X is a proper subset of Y then Y is a better choice and ought

  142545. ** to have a lower cost.  This routine returns TRUE when that cost 

  142546. ** relationship is inverted and needs to be adjusted.  Constraint (4)

  142547. ** was added because if X uses skip-scan less than Y it still might

  142548. ** deserve a lower cost even if it is a proper subset of Y.  Constraint (5)

  142549. ** was added because a covering index probably deserves to have a lower cost

  142550. ** than a non-covering index even if it is a proper subset.

  142551. */

  142552. static int whereLoopCheaperProperSubset(

  142553.   const WhereLoop *pX,       /* First WhereLoop to compare */

  142554.   const WhereLoop *pY        /* Compare against this WhereLoop */

  142555. ){

  142556.   int i, j;

  142557.   if( pX->nLTerm-pX->nSkip >= pY->nLTerm-pY->nSkip ){

  142558.     return 0; /* X is not a subset of Y */

  142559.   }

  142560.   if( pY->nSkip > pX->nSkip ) return 0;

  142561.   if( pX->rRun >= pY->rRun ){

  142562.     if( pX->rRun > pY->rRun ) return 0;    /* X costs more than Y */

  142563.     if( pX->nOut > pY->nOut ) return 0;    /* X costs more than Y */

  142564.   }

  142565.   for(i=pX->nLTerm-1; i>=0; i--){

  142566.     if( pX->aLTerm[i]==0 ) continue;

  142567.     for(j=pY->nLTerm-1; j>=0; j--){

  142568.       if( pY->aLTerm[j]==pX->aLTerm[i] ) break;

  142569.     }

  142570.     if( j<0 ) return 0;  /* X not a subset of Y since term X[i] not used by Y */

  142571.   }

  142572.   if( (pX->wsFlags&WHERE_IDX_ONLY)!=0 

  142573.    && (pY->wsFlags&WHERE_IDX_ONLY)==0 ){

  142574.     return 0;  /* Constraint (5) */

  142575.   }

  142576.   return 1;  /* All conditions meet */

  142577. }

  142578. 

  142579. /*

  142580. ** Try to adjust the cost of WhereLoop pTemplate upwards or downwards so

  142581. ** that:

  142582. **

  142583. **   (1) pTemplate costs less than any other WhereLoops that are a proper

  142584. **       subset of pTemplate

  142585. **

  142586. **   (2) pTemplate costs more than any other WhereLoops for which pTemplate

  142587. **       is a proper subset.

  142588. **

  142589. ** To say "WhereLoop X is a proper subset of Y" means that X uses fewer

  142590. ** WHERE clause terms than Y and that every WHERE clause term used by X is

  142591. ** also used by Y.

  142592. */

  142593. static void whereLoopAdjustCost(const WhereLoop *p, WhereLoop *pTemplate){

  142594.   if( (pTemplate->wsFlags & WHERE_INDEXED)==0 ) return;

  142595.   for(; p; p=p->pNextLoop){

  142596.     if( p->iTab!=pTemplate->iTab ) continue;

  142597.     if( (p->wsFlags & WHERE_INDEXED)==0 ) continue;

  142598.     if( whereLoopCheaperProperSubset(p, pTemplate) ){

  142599.       /* Adjust pTemplate cost downward so that it is cheaper than its 

  142600.       ** subset p. */

  142601.       WHERETRACE(0x80,("subset cost adjustment %d,%d to %d,%d\n",

  142602.                        pTemplate->rRun, pTemplate->nOut, p->rRun, p->nOut-1));

  142603.       pTemplate->rRun = p->rRun;

  142604.       pTemplate->nOut = p->nOut - 1;

  142605.     }else if( whereLoopCheaperProperSubset(pTemplate, p) ){

  142606.       /* Adjust pTemplate cost upward so that it is costlier than p since

  142607.       ** pTemplate is a proper subset of p */

  142608.       WHERETRACE(0x80,("subset cost adjustment %d,%d to %d,%d\n",

  142609.                        pTemplate->rRun, pTemplate->nOut, p->rRun, p->nOut+1));

  142610.       pTemplate->rRun = p->rRun;

  142611.       pTemplate->nOut = p->nOut + 1;

  142612.     }

  142613.   }

  142614. }

  142615. 

  142616. /*

  142617. ** Search the list of WhereLoops in *ppPrev looking for one that can be

  142618. ** replaced by pTemplate.

  142619. **

  142620. ** Return NULL if pTemplate does not belong on the WhereLoop list.

  142621. ** In other words if pTemplate ought to be dropped from further consideration.

  142622. **

  142623. ** If pX is a WhereLoop that pTemplate can replace, then return the

  142624. ** link that points to pX.

  142625. **

  142626. ** If pTemplate cannot replace any existing element of the list but needs

  142627. ** to be added to the list as a new entry, then return a pointer to the

  142628. ** tail of the list.

  142629. */

  142630. static WhereLoop **whereLoopFindLesser(

  142631.   WhereLoop **ppPrev,

  142632.   const WhereLoop *pTemplate

  142633. ){

  142634.   WhereLoop *p;

  142635.   for(p=(*ppPrev); p; ppPrev=&p->pNextLoop, p=*ppPrev){

  142636.     if( p->iTab!=pTemplate->iTab || p->iSortIdx!=pTemplate->iSortIdx ){

  142637.       /* If either the iTab or iSortIdx values for two WhereLoop are different

  142638.       ** then those WhereLoops need to be considered separately.  Neither is

  142639.       ** a candidate to replace the other. */

  142640.       continue;

  142641.     }

  142642.     /* In the current implementation, the rSetup value is either zero

  142643.     ** or the cost of building an automatic index (NlogN) and the NlogN

  142644.     ** is the same for compatible WhereLoops. */

  142645.     assert( p->rSetup==0 || pTemplate->rSetup==0 

  142646.                  || p->rSetup==pTemplate->rSetup );

  142647. 

  142648.     /* whereLoopAddBtree() always generates and inserts the automatic index

  142649.     ** case first.  Hence compatible candidate WhereLoops never have a larger

  142650.     ** rSetup. Call this SETUP-INVARIANT */

  142651.     assert( p->rSetup>=pTemplate->rSetup );

  142652. 

  142653.     /* Any loop using an appliation-defined index (or PRIMARY KEY or

  142654.     ** UNIQUE constraint) with one or more == constraints is better

  142655.     ** than an automatic index. Unless it is a skip-scan. */

  142656.     if( (p->wsFlags & WHERE_AUTO_INDEX)!=0

  142657.      && (pTemplate->nSkip)==0

  142658.      && (pTemplate->wsFlags & WHERE_INDEXED)!=0

  142659.      && (pTemplate->wsFlags & WHERE_COLUMN_EQ)!=0

  142660.      && (p->prereq & pTemplate->prereq)==pTemplate->prereq

  142661.     ){

  142662.       break;

  142663.     }

  142664. 

  142665.     /* If existing WhereLoop p is better than pTemplate, pTemplate can be

  142666.     ** discarded.  WhereLoop p is better if:

  142667.     **   (1)  p has no more dependencies than pTemplate, and

  142668.     **   (2)  p has an equal or lower cost than pTemplate

  142669.     */

  142670.     if( (p->prereq & pTemplate->prereq)==p->prereq    /* (1)  */

  142671.      && p->rSetup<=pTemplate->rSetup                  /* (2a) */

  142672.      && p->rRun<=pTemplate->rRun                      /* (2b) */

  142673.      && p->nOut<=pTemplate->nOut                      /* (2c) */

  142674.     ){

  142675.       return 0;  /* Discard pTemplate */

  142676.     }

  142677. 

  142678.     /* If pTemplate is always better than p, then cause p to be overwritten

  142679.     ** with pTemplate.  pTemplate is better than p if:

  142680.     **   (1)  pTemplate has no more dependences than p, and

  142681.     **   (2)  pTemplate has an equal or lower cost than p.

  142682.     */

  142683.     if( (p->prereq & pTemplate->prereq)==pTemplate->prereq   /* (1)  */

  142684.      && p->rRun>=pTemplate->rRun                             /* (2a) */

  142685.      && p->nOut>=pTemplate->nOut                             /* (2b) */

  142686.     ){

  142687.       assert( p->rSetup>=pTemplate->rSetup ); /* SETUP-INVARIANT above */

  142688.       break;   /* Cause p to be overwritten by pTemplate */

  142689.     }

  142690.   }

  142691.   return ppPrev;

  142692. }

  142693. 

  142694. /*

  142695. ** Insert or replace a WhereLoop entry using the template supplied.

  142696. **

  142697. ** An existing WhereLoop entry might be overwritten if the new template

  142698. ** is better and has fewer dependencies.  Or the template will be ignored

  142699. ** and no insert will occur if an existing WhereLoop is faster and has

  142700. ** fewer dependencies than the template.  Otherwise a new WhereLoop is

  142701. ** added based on the template.

  142702. **

  142703. ** If pBuilder->pOrSet is not NULL then we care about only the

  142704. ** prerequisites and rRun and nOut costs of the N best loops.  That

  142705. ** information is gathered in the pBuilder->pOrSet object.  This special

  142706. ** processing mode is used only for OR clause processing.

  142707. **

  142708. ** When accumulating multiple loops (when pBuilder->pOrSet is NULL) we

  142709. ** still might overwrite similar loops with the new template if the

  142710. ** new template is better.  Loops may be overwritten if the following 

  142711. ** conditions are met:

  142712. **

  142713. **    (1)  They have the same iTab.

  142714. **    (2)  They have the same iSortIdx.

  142715. **    (3)  The template has same or fewer dependencies than the current loop

  142716. **    (4)  The template has the same or lower cost than the current loop

  142717. */

  142718. static int whereLoopInsert(WhereLoopBuilder *pBuilder, WhereLoop *pTemplate){

  142719.   WhereLoop **ppPrev, *p;

  142720.   WhereInfo *pWInfo = pBuilder->pWInfo;

  142721.   sqlite3 *db = pWInfo->pParse->db;

  142722.   int rc;

  142723. 

  142724.   /* Stop the search once we hit the query planner search limit */

  142725.   if( pBuilder->iPlanLimit==0 ){

  142726.     WHERETRACE(0xffffffff,("=== query planner search limit reached ===\n"));

  142727.     if( pBuilder->pOrSet ) pBuilder->pOrSet->n = 0;

  142728.     return SQLITE_DONE;

  142729.   }

  142730.   pBuilder->iPlanLimit--;

  142731. 

  142732.   /* If pBuilder->pOrSet is defined, then only keep track of the costs

  142733.   ** and prereqs.

  142734.   */

  142735.   if( pBuilder->pOrSet!=0 ){

  142736.     if( pTemplate->nLTerm ){

  142737. #if WHERETRACE_ENABLED

  142738.       u16 n = pBuilder->pOrSet->n;

  142739.       int x =

  142740. #endif

  142741.       whereOrInsert(pBuilder->pOrSet, pTemplate->prereq, pTemplate->rRun,

  142742.                                     pTemplate->nOut);

  142743. #if WHERETRACE_ENABLED /* 0x8 */

  142744.       if( sqlite3WhereTrace & 0x8 ){

  142745.         sqlite3DebugPrintf(x?"   or-%d:  ":"   or-X:  ", n);

  142746.         whereLoopPrint(pTemplate, pBuilder->pWC);

  142747.       }

  142748. #endif

  142749.     }

  142750.     return SQLITE_OK;

  142751.   }

  142752. 

  142753.   /* Look for an existing WhereLoop to replace with pTemplate

  142754.   */

  142755.   whereLoopAdjustCost(pWInfo->pLoops, pTemplate);

  142756.   ppPrev = whereLoopFindLesser(&pWInfo->pLoops, pTemplate);

  142757. 

  142758.   if( ppPrev==0 ){

  142759.     /* There already exists a WhereLoop on the list that is better

  142760.     ** than pTemplate, so just ignore pTemplate */

  142761. #if WHERETRACE_ENABLED /* 0x8 */

  142762.     if( sqlite3WhereTrace & 0x8 ){

  142763.       sqlite3DebugPrintf("   skip: ");

  142764.       whereLoopPrint(pTemplate, pBuilder->pWC);

  142765.     }

  142766. #endif

  142767.     return SQLITE_OK;  

  142768.   }else{

  142769.     p = *ppPrev;

  142770.   }

  142771. 

  142772.   /* If we reach this point it means that either p[] should be overwritten

  142773.   ** with pTemplate[] if p[] exists, or if p==NULL then allocate a new

  142774.   ** WhereLoop and insert it.

  142775.   */

  142776. #if WHERETRACE_ENABLED /* 0x8 */

  142777.   if( sqlite3WhereTrace & 0x8 ){

  142778.     if( p!=0 ){

  142779.       sqlite3DebugPrintf("replace: ");

  142780.       whereLoopPrint(p, pBuilder->pWC);

  142781.       sqlite3DebugPrintf("   with: ");

  142782.     }else{

  142783.       sqlite3DebugPrintf("    add: ");

  142784.     }

  142785.     whereLoopPrint(pTemplate, pBuilder->pWC);

  142786.   }

  142787. #endif

  142788.   if( p==0 ){

  142789.     /* Allocate a new WhereLoop to add to the end of the list */

  142790.     *ppPrev = p = sqlite3DbMallocRawNN(db, sizeof(WhereLoop));

  142791.     if( p==0 ) return SQLITE_NOMEM_BKPT;

  142792.     whereLoopInit(p);

  142793.     p->pNextLoop = 0;

  142794.   }else{

  142795.     /* We will be overwriting WhereLoop p[].  But before we do, first

  142796.     ** go through the rest of the list and delete any other entries besides

  142797.     ** p[] that are also supplated by pTemplate */

  142798.     WhereLoop **ppTail = &p->pNextLoop;

  142799.     WhereLoop *pToDel;

  142800.     while( *ppTail ){

  142801.       ppTail = whereLoopFindLesser(ppTail, pTemplate);

  142802.       if( ppTail==0 ) break;

  142803.       pToDel = *ppTail;

  142804.       if( pToDel==0 ) break;

  142805.       *ppTail = pToDel->pNextLoop;

  142806. #if WHERETRACE_ENABLED /* 0x8 */

  142807.       if( sqlite3WhereTrace & 0x8 ){

  142808.         sqlite3DebugPrintf(" delete: ");

  142809.         whereLoopPrint(pToDel, pBuilder->pWC);

  142810.       }

  142811. #endif

  142812.       whereLoopDelete(db, pToDel);

  142813.     }

  142814.   }

  142815.   rc = whereLoopXfer(db, p, pTemplate);

  142816.   if( (p->wsFlags & WHERE_VIRTUALTABLE)==0 ){

  142817.     Index *pIndex = p->u.btree.pIndex;

  142818.     if( pIndex && pIndex->idxType==SQLITE_IDXTYPE_IPK ){

  142819.       p->u.btree.pIndex = 0;

  142820.     }

  142821.   }

  142822.   return rc;

  142823. }

  142824. 

  142825. /*

  142826. ** Adjust the WhereLoop.nOut value downward to account for terms of the

  142827. ** WHERE clause that reference the loop but which are not used by an

  142828. ** index.

  142829. *

  142830. ** For every WHERE clause term that is not used by the index

  142831. ** and which has a truth probability assigned by one of the likelihood(),

  142832. ** likely(), or unlikely() SQL functions, reduce the estimated number

  142833. ** of output rows by the probability specified.

  142834. **

  142835. ** TUNING:  For every WHERE clause term that is not used by the index

  142836. ** and which does not have an assigned truth probability, heuristics

  142837. ** described below are used to try to estimate the truth probability.

  142838. ** TODO --> Perhaps this is something that could be improved by better

  142839. ** table statistics.

  142840. **

  142841. ** Heuristic 1:  Estimate the truth probability as 93.75%.  The 93.75%

  142842. ** value corresponds to -1 in LogEst notation, so this means decrement

  142843. ** the WhereLoop.nOut field for every such WHERE clause term.

  142844. **

  142845. ** Heuristic 2:  If there exists one or more WHERE clause terms of the

  142846. ** form "x==EXPR" and EXPR is not a constant 0 or 1, then make sure the

  142847. ** final output row estimate is no greater than 1/4 of the total number

  142848. ** of rows in the table.  In other words, assume that x==EXPR will filter

  142849. ** out at least 3 out of 4 rows.  If EXPR is -1 or 0 or 1, then maybe the

  142850. ** "x" column is boolean or else -1 or 0 or 1 is a common default value

  142851. ** on the "x" column and so in that case only cap the output row estimate

  142852. ** at 1/2 instead of 1/4.

  142853. */

  142854. static void whereLoopOutputAdjust(

  142855.   WhereClause *pWC,      /* The WHERE clause */

  142856.   WhereLoop *pLoop,      /* The loop to adjust downward */

  142857.   LogEst nRow            /* Number of rows in the entire table */

  142858. ){

  142859.   WhereTerm *pTerm, *pX;

  142860.   Bitmask notAllowed = ~(pLoop->prereq|pLoop->maskSelf);

  142861.   int i, j, k;

  142862.   LogEst iReduce = 0;    /* pLoop->nOut should not exceed nRow-iReduce */

  142863. 

  142864.   assert( (pLoop->wsFlags & WHERE_AUTO_INDEX)==0 );

  142865.   for(i=pWC->nTerm, pTerm=pWC->a; i>0; i--, pTerm++){

  142866.     if( (pTerm->wtFlags & TERM_VIRTUAL)!=0 ) break;

  142867.     if( (pTerm->prereqAll & pLoop->maskSelf)==0 ) continue;

  142868.     if( (pTerm->prereqAll & notAllowed)!=0 ) continue;

  142869.     for(j=pLoop->nLTerm-1; j>=0; j--){

  142870.       pX = pLoop->aLTerm[j];

  142871.       if( pX==0 ) continue;

  142872.       if( pX==pTerm ) break;

  142873.       if( pX->iParent>=0 && (&pWC->a[pX->iParent])==pTerm ) break;

  142874.     }

  142875.     if( j<0 ){

  142876.       if( pTerm->truthProb<=0 ){

  142877.         /* If a truth probability is specified using the likelihood() hints,

  142878.         ** then use the probability provided by the application. */

  142879.         pLoop->nOut += pTerm->truthProb;

  142880.       }else{

  142881.         /* In the absence of explicit truth probabilities, use heuristics to

  142882.         ** guess a reasonable truth probability. */

  142883.         pLoop->nOut--;

  142884.         if( pTerm->eOperator&(WO_EQ|WO_IS) ){

  142885.           Expr *pRight = pTerm->pExpr->pRight;

  142886.           testcase( pTerm->pExpr->op==TK_IS );

  142887.           if( sqlite3ExprIsInteger(pRight, &k) && k>=(-1) && k<=1 ){

  142888.             k = 10;

  142889.           }else{

  142890.             k = 20;

  142891.           }

  142892.           if( iReduce<k ) iReduce = k;

  142893.         }

  142894.       }

  142895.     }

  142896.   }

  142897.   if( pLoop->nOut > nRow-iReduce )  pLoop->nOut = nRow - iReduce;

  142898. }

  142899. 

  142900. /* 

  142901. ** Term pTerm is a vector range comparison operation. The first comparison

  142902. ** in the vector can be optimized using column nEq of the index. This

  142903. ** function returns the total number of vector elements that can be used

  142904. ** as part of the range comparison.

  142905. **

  142906. ** For example, if the query is:

  142907. **

  142908. **   WHERE a = ? AND (b, c, d) > (?, ?, ?)

  142909. **

  142910. ** and the index:

  142911. **

  142912. **   CREATE INDEX ... ON (a, b, c, d, e)

  142913. **

  142914. ** then this function would be invoked with nEq=1. The value returned in

  142915. ** this case is 3.

  142916. */

  142917. static int whereRangeVectorLen(

  142918.   Parse *pParse,       /* Parsing context */

  142919.   int iCur,            /* Cursor open on pIdx */

  142920.   Index *pIdx,         /* The index to be used for a inequality constraint */

  142921.   int nEq,             /* Number of prior equality constraints on same index */

  142922.   WhereTerm *pTerm     /* The vector inequality constraint */

  142923. ){

  142924.   int nCmp = sqlite3ExprVectorSize(pTerm->pExpr->pLeft);

  142925.   int i;

  142926. 

  142927.   nCmp = MIN(nCmp, (pIdx->nColumn - nEq));

  142928.   for(i=1; i<nCmp; i++){

  142929.     /* Test if comparison i of pTerm is compatible with column (i+nEq) 

  142930.     ** of the index. If not, exit the loop.  */

  142931.     char aff;                     /* Comparison affinity */

  142932.     char idxaff = 0;              /* Indexed columns affinity */

  142933.     CollSeq *pColl;               /* Comparison collation sequence */

  142934.     Expr *pLhs = pTerm->pExpr->pLeft->x.pList->a[i].pExpr;

  142935.     Expr *pRhs = pTerm->pExpr->pRight;

  142936.     if( pRhs->flags & EP_xIsSelect ){

  142937.       pRhs = pRhs->x.pSelect->pEList->a[i].pExpr;

  142938.     }else{

  142939.       pRhs = pRhs->x.pList->a[i].pExpr;

  142940.     }

  142941. 

  142942.     /* Check that the LHS of the comparison is a column reference to

  142943.     ** the right column of the right source table. And that the sort

  142944.     ** order of the index column is the same as the sort order of the

  142945.     ** leftmost index column.  */

  142946.     if( pLhs->op!=TK_COLUMN 

  142947.      || pLhs->iTable!=iCur 

  142948.      || pLhs->iColumn!=pIdx->aiColumn[i+nEq] 

  142949.      || pIdx->aSortOrder[i+nEq]!=pIdx->aSortOrder[nEq]

  142950.     ){

  142951.       break;

  142952.     }

  142953. 

  142954.     testcase( pLhs->iColumn==XN_ROWID );

  142955.     aff = sqlite3CompareAffinity(pRhs, sqlite3ExprAffinity(pLhs));

  142956.     idxaff = sqlite3TableColumnAffinity(pIdx->pTable, pLhs->iColumn);

  142957.     if( aff!=idxaff ) break;

  142958. 

  142959.     pColl = sqlite3BinaryCompareCollSeq(pParse, pLhs, pRhs);

  142960.     if( pColl==0 ) break;

  142961.     if( sqlite3StrICmp(pColl->zName, pIdx->azColl[i+nEq]) ) break;

  142962.   }

  142963.   return i;

  142964. }

  142965. 

  142966. /*

  142967. ** Adjust the cost C by the costMult facter T.  This only occurs if

  142968. ** compiled with -DSQLITE_ENABLE_COSTMULT

  142969. */

  142970. #ifdef SQLITE_ENABLE_COSTMULT

  142971. # define ApplyCostMultiplier(C,T)  C += T

  142972. #else

  142973. # define ApplyCostMultiplier(C,T)

  142974. #endif

  142975. 

  142976. /*

  142977. ** We have so far matched pBuilder->pNew->u.btree.nEq terms of the 

  142978. ** index pIndex. Try to match one more.

  142979. **

  142980. ** When this function is called, pBuilder->pNew->nOut contains the 

  142981. ** number of rows expected to be visited by filtering using the nEq 

  142982. ** terms only. If it is modified, this value is restored before this 

  142983. ** function returns.

  142984. **

  142985. ** If pProbe->idxType==SQLITE_IDXTYPE_IPK, that means pIndex is 

  142986. ** a fake index used for the INTEGER PRIMARY KEY.

  142987. */

  142988. static int whereLoopAddBtreeIndex(

  142989.   WhereLoopBuilder *pBuilder,     /* The WhereLoop factory */

  142990.   struct SrcList_item *pSrc,      /* FROM clause term being analyzed */

  142991.   Index *pProbe,                  /* An index on pSrc */

  142992.   LogEst nInMul                   /* log(Number of iterations due to IN) */

  142993. ){

  142994.   WhereInfo *pWInfo = pBuilder->pWInfo;  /* WHERE analyse context */

  142995.   Parse *pParse = pWInfo->pParse;        /* Parsing context */

  142996.   sqlite3 *db = pParse->db;       /* Database connection malloc context */

  142997.   WhereLoop *pNew;                /* Template WhereLoop under construction */

  142998.   WhereTerm *pTerm;               /* A WhereTerm under consideration */

  142999.   int opMask;                     /* Valid operators for constraints */

  143000.   WhereScan scan;                 /* Iterator for WHERE terms */

  143001.   Bitmask saved_prereq;           /* Original value of pNew->prereq */

  143002.   u16 saved_nLTerm;               /* Original value of pNew->nLTerm */

  143003.   u16 saved_nEq;                  /* Original value of pNew->u.btree.nEq */

  143004.   u16 saved_nBtm;                 /* Original value of pNew->u.btree.nBtm */

  143005.   u16 saved_nTop;                 /* Original value of pNew->u.btree.nTop */

  143006.   u16 saved_nSkip;                /* Original value of pNew->nSkip */

  143007.   u32 saved_wsFlags;              /* Original value of pNew->wsFlags */

  143008.   LogEst saved_nOut;              /* Original value of pNew->nOut */

  143009.   int rc = SQLITE_OK;             /* Return code */

  143010.   LogEst rSize;                   /* Number of rows in the table */

  143011.   LogEst rLogSize;                /* Logarithm of table size */

  143012.   WhereTerm *pTop = 0, *pBtm = 0; /* Top and bottom range constraints */

  143013. 

  143014.   pNew = pBuilder->pNew;

  143015.   if( db->mallocFailed ) return SQLITE_NOMEM_BKPT;

  143016.   WHERETRACE(0x800, ("BEGIN %s.addBtreeIdx(%s), nEq=%d\n",

  143017.                      pProbe->pTable->zName,pProbe->zName, pNew->u.btree.nEq));

  143018. 

  143019.   assert( (pNew->wsFlags & WHERE_VIRTUALTABLE)==0 );

  143020.   assert( (pNew->wsFlags & WHERE_TOP_LIMIT)==0 );

  143021.   if( pNew->wsFlags & WHERE_BTM_LIMIT ){

  143022.     opMask = WO_LT|WO_LE;

  143023.   }else{

  143024.     assert( pNew->u.btree.nBtm==0 );

  143025.     opMask = WO_EQ|WO_IN|WO_GT|WO_GE|WO_LT|WO_LE|WO_ISNULL|WO_IS;

  143026.   }

  143027.   if( pProbe->bUnordered ) opMask &= ~(WO_GT|WO_GE|WO_LT|WO_LE);

  143028. 

  143029.   assert( pNew->u.btree.nEq<pProbe->nColumn );

  143030. 

  143031.   saved_nEq = pNew->u.btree.nEq;

  143032.   saved_nBtm = pNew->u.btree.nBtm;

  143033.   saved_nTop = pNew->u.btree.nTop;

  143034.   saved_nSkip = pNew->nSkip;

  143035.   saved_nLTerm = pNew->nLTerm;

  143036.   saved_wsFlags = pNew->wsFlags;

  143037.   saved_prereq = pNew->prereq;

  143038.   saved_nOut = pNew->nOut;

  143039.   pTerm = whereScanInit(&scan, pBuilder->pWC, pSrc->iCursor, saved_nEq,

  143040.                         opMask, pProbe);

  143041.   pNew->rSetup = 0;

  143042.   rSize = pProbe->aiRowLogEst[0];

  143043.   rLogSize = estLog(rSize);

  143044.   for(; rc==SQLITE_OK && pTerm!=0; pTerm = whereScanNext(&scan)){

  143045.     u16 eOp = pTerm->eOperator;   /* Shorthand for pTerm->eOperator */

  143046.     LogEst rCostIdx;

  143047.     LogEst nOutUnadjusted;        /* nOut before IN() and WHERE adjustments */

  143048.     int nIn = 0;

  143049. #ifdef SQLITE_ENABLE_STAT3_OR_STAT4

  143050.     int nRecValid = pBuilder->nRecValid;

  143051. #endif

  143052.     if( (eOp==WO_ISNULL || (pTerm->wtFlags&TERM_VNULL)!=0)

  143053.      && indexColumnNotNull(pProbe, saved_nEq)

  143054.     ){

  143055.       continue; /* ignore IS [NOT] NULL constraints on NOT NULL columns */

  143056.     }

  143057.     if( pTerm->prereqRight & pNew->maskSelf ) continue;

  143058. 

  143059.     /* Do not allow the upper bound of a LIKE optimization range constraint

  143060.     ** to mix with a lower range bound from some other source */

  143061.     if( pTerm->wtFlags & TERM_LIKEOPT && pTerm->eOperator==WO_LT ) continue;

  143062. 

  143063.     /* Do not allow constraints from the WHERE clause to be used by the

  143064.     ** right table of a LEFT JOIN.  Only constraints in the ON clause are

  143065.     ** allowed */

  143066.     if( (pSrc->fg.jointype & JT_LEFT)!=0

  143067.      && !ExprHasProperty(pTerm->pExpr, EP_FromJoin)

  143068.     ){

  143069.       continue;

  143070.     }

  143071. 

  143072.     if( IsUniqueIndex(pProbe) && saved_nEq==pProbe->nKeyCol-1 ){

  143073.       pBuilder->bldFlags |= SQLITE_BLDF_UNIQUE;

  143074.     }else{

  143075.       pBuilder->bldFlags |= SQLITE_BLDF_INDEXED;

  143076.     }

  143077.     pNew->wsFlags = saved_wsFlags;

  143078.     pNew->u.btree.nEq = saved_nEq;

  143079.     pNew->u.btree.nBtm = saved_nBtm;

  143080.     pNew->u.btree.nTop = saved_nTop;

  143081.     pNew->nLTerm = saved_nLTerm;

  143082.     if( whereLoopResize(db, pNew, pNew->nLTerm+1) ) break; /* OOM */

  143083.     pNew->aLTerm[pNew->nLTerm++] = pTerm;

  143084.     pNew->prereq = (saved_prereq | pTerm->prereqRight) & ~pNew->maskSelf;

  143085. 

  143086.     assert( nInMul==0

  143087.         || (pNew->wsFlags & WHERE_COLUMN_NULL)!=0 

  143088.         || (pNew->wsFlags & WHERE_COLUMN_IN)!=0 

  143089.         || (pNew->wsFlags & WHERE_SKIPSCAN)!=0 

  143090.     );

  143091. 

  143092.     if( eOp & WO_IN ){

  143093.       Expr *pExpr = pTerm->pExpr;

  143094.       if( ExprHasProperty(pExpr, EP_xIsSelect) ){

  143095.         /* "x IN (SELECT ...)":  TUNING: the SELECT returns 25 rows */

  143096.         int i;

  143097.         nIn = 46;  assert( 46==sqlite3LogEst(25) );

  143098. 

  143099.         /* The expression may actually be of the form (x, y) IN (SELECT...).

  143100.         ** In this case there is a separate term for each of (x) and (y).

  143101.         ** However, the nIn multiplier should only be applied once, not once

  143102.         ** for each such term. The following loop checks that pTerm is the

  143103.         ** first such term in use, and sets nIn back to 0 if it is not. */

  143104.         for(i=0; i<pNew->nLTerm-1; i++){

  143105.           if( pNew->aLTerm[i] && pNew->aLTerm[i]->pExpr==pExpr ) nIn = 0;

  143106.         }

  143107.       }else if( ALWAYS(pExpr->x.pList && pExpr->x.pList->nExpr) ){

  143108.         /* "x IN (value, value, ...)" */

  143109.         nIn = sqlite3LogEst(pExpr->x.pList->nExpr);

  143110.         assert( nIn>0 );  /* RHS always has 2 or more terms...  The parser

  143111.                           ** changes "x IN (?)" into "x=?". */

  143112.       }

  143113.       if( pProbe->hasStat1 ){

  143114.         LogEst M, logK, safetyMargin;

  143115.         /* Let:

  143116.         **   N = the total number of rows in the table

  143117.         **   K = the number of entries on the RHS of the IN operator

  143118.         **   M = the number of rows in the table that match terms to the 

  143119.         **       to the left in the same index.  If the IN operator is on

  143120.         **       the left-most index column, M==N.

  143121.         **

  143122.         ** Given the definitions above, it is better to omit the IN operator

  143123.         ** from the index lookup and instead do a scan of the M elements,

  143124.         ** testing each scanned row against the IN operator separately, if:

  143125.         **

  143126.         **        M*log(K) < K*log(N)

  143127.         **

  143128.         ** Our estimates for M, K, and N might be inaccurate, so we build in

  143129.         ** a safety margin of 2 (LogEst: 10) that favors using the IN operator

  143130.         ** with the index, as using an index has better worst-case behavior.

  143131.         ** If we do not have real sqlite_stat1 data, always prefer to use

  143132.         ** the index.

  143133.         */

  143134.         M = pProbe->aiRowLogEst[saved_nEq];

  143135.         logK = estLog(nIn);

  143136.         safetyMargin = 10;  /* TUNING: extra weight for indexed IN */

  143137.         if( M + logK + safetyMargin < nIn + rLogSize ){

  143138.           WHERETRACE(0x40,

  143139.             ("Scan preferred over IN operator on column %d of \"%s\" (%d<%d)\n",

  143140.              saved_nEq, pProbe->zName, M+logK+10, nIn+rLogSize));

  143141.           continue;

  143142.         }else{

  143143.           WHERETRACE(0x40,

  143144.             ("IN operator preferred on column %d of \"%s\" (%d>=%d)\n",

  143145.              saved_nEq, pProbe->zName, M+logK+10, nIn+rLogSize));

  143146.         }

  143147.       }

  143148.       pNew->wsFlags |= WHERE_COLUMN_IN;

  143149.     }else if( eOp & (WO_EQ|WO_IS) ){

  143150.       int iCol = pProbe->aiColumn[saved_nEq];

  143151.       pNew->wsFlags |= WHERE_COLUMN_EQ;

  143152.       assert( saved_nEq==pNew->u.btree.nEq );

  143153.       if( iCol==XN_ROWID 

  143154.        || (iCol>=0 && nInMul==0 && saved_nEq==pProbe->nKeyCol-1)

  143155.       ){

  143156.         if( iCol==XN_ROWID || pProbe->uniqNotNull 

  143157.          || (pProbe->nKeyCol==1 && pProbe->onError && eOp==WO_EQ) 

  143158.         ){

  143159.           pNew->wsFlags |= WHERE_ONEROW;

  143160.         }else{

  143161.           pNew->wsFlags |= WHERE_UNQ_WANTED;

  143162.         }

  143163.       }

  143164.     }else if( eOp & WO_ISNULL ){

  143165.       pNew->wsFlags |= WHERE_COLUMN_NULL;

  143166.     }else if( eOp & (WO_GT|WO_GE) ){

  143167.       testcase( eOp & WO_GT );

  143168.       testcase( eOp & WO_GE );

  143169.       pNew->wsFlags |= WHERE_COLUMN_RANGE|WHERE_BTM_LIMIT;

  143170.       pNew->u.btree.nBtm = whereRangeVectorLen(

  143171.           pParse, pSrc->iCursor, pProbe, saved_nEq, pTerm

  143172.       );

  143173.       pBtm = pTerm;

  143174.       pTop = 0;

  143175.       if( pTerm->wtFlags & TERM_LIKEOPT ){

  143176.         /* Range contraints that come from the LIKE optimization are

  143177.         ** always used in pairs. */

  143178.         pTop = &pTerm[1];

  143179.         assert( (pTop-(pTerm->pWC->a))<pTerm->pWC->nTerm );

  143180.         assert( pTop->wtFlags & TERM_LIKEOPT );

  143181.         assert( pTop->eOperator==WO_LT );

  143182.         if( whereLoopResize(db, pNew, pNew->nLTerm+1) ) break; /* OOM */

  143183.         pNew->aLTerm[pNew->nLTerm++] = pTop;

  143184.         pNew->wsFlags |= WHERE_TOP_LIMIT;

  143185.         pNew->u.btree.nTop = 1;

  143186.       }

  143187.     }else{

  143188.       assert( eOp & (WO_LT|WO_LE) );

  143189.       testcase( eOp & WO_LT );

  143190.       testcase( eOp & WO_LE );

  143191.       pNew->wsFlags |= WHERE_COLUMN_RANGE|WHERE_TOP_LIMIT;

  143192.       pNew->u.btree.nTop = whereRangeVectorLen(

  143193.           pParse, pSrc->iCursor, pProbe, saved_nEq, pTerm

  143194.       );

  143195.       pTop = pTerm;

  143196.       pBtm = (pNew->wsFlags & WHERE_BTM_LIMIT)!=0 ?

  143197.                      pNew->aLTerm[pNew->nLTerm-2] : 0;

  143198.     }

  143199. 

  143200.     /* At this point pNew->nOut is set to the number of rows expected to

  143201.     ** be visited by the index scan before considering term pTerm, or the

  143202.     ** values of nIn and nInMul. In other words, assuming that all 

  143203.     ** "x IN(...)" terms are replaced with "x = ?". This block updates

  143204.     ** the value of pNew->nOut to account for pTerm (but not nIn/nInMul).  */

  143205.     assert( pNew->nOut==saved_nOut );

  143206.     if( pNew->wsFlags & WHERE_COLUMN_RANGE ){

  143207.       /* Adjust nOut using stat3/stat4 data. Or, if there is no stat3/stat4

  143208.       ** data, using some other estimate.  */

  143209.       whereRangeScanEst(pParse, pBuilder, pBtm, pTop, pNew);

  143210.     }else{

  143211.       int nEq = ++pNew->u.btree.nEq;

  143212.       assert( eOp & (WO_ISNULL|WO_EQ|WO_IN|WO_IS) );

  143213. 

  143214.       assert( pNew->nOut==saved_nOut );

  143215.       if( pTerm->truthProb<=0 && pProbe->aiColumn[saved_nEq]>=0 ){

  143216.         assert( (eOp & WO_IN) || nIn==0 );

  143217.         testcase( eOp & WO_IN );

  143218.         pNew->nOut += pTerm->truthProb;

  143219.         pNew->nOut -= nIn;

  143220.       }else{

  143221. #ifdef SQLITE_ENABLE_STAT3_OR_STAT4

  143222.         tRowcnt nOut = 0;

  143223.         if( nInMul==0 

  143224.          && pProbe->nSample 

  143225.          && pNew->u.btree.nEq<=pProbe->nSampleCol

  143226.          && ((eOp & WO_IN)==0 || !ExprHasProperty(pTerm->pExpr, EP_xIsSelect))

  143227.          && OptimizationEnabled(db, SQLITE_Stat34)

  143228.         ){

  143229.           Expr *pExpr = pTerm->pExpr;

  143230.           if( (eOp & (WO_EQ|WO_ISNULL|WO_IS))!=0 ){

  143231.             testcase( eOp & WO_EQ );

  143232.             testcase( eOp & WO_IS );

  143233.             testcase( eOp & WO_ISNULL );

  143234.             rc = whereEqualScanEst(pParse, pBuilder, pExpr->pRight, &nOut);

  143235.           }else{

  143236.             rc = whereInScanEst(pParse, pBuilder, pExpr->x.pList, &nOut);

  143237.           }

  143238.           if( rc==SQLITE_NOTFOUND ) rc = SQLITE_OK;

  143239.           if( rc!=SQLITE_OK ) break;          /* Jump out of the pTerm loop */

  143240.           if( nOut ){

  143241.             pNew->nOut = sqlite3LogEst(nOut);

  143242.             if( pNew->nOut>saved_nOut ) pNew->nOut = saved_nOut;

  143243.             pNew->nOut -= nIn;

  143244.           }

  143245.         }

  143246.         if( nOut==0 )

  143247. #endif

  143248.         {

  143249.           pNew->nOut += (pProbe->aiRowLogEst[nEq] - pProbe->aiRowLogEst[nEq-1]);

  143250.           if( eOp & WO_ISNULL ){

  143251.             /* TUNING: If there is no likelihood() value, assume that a 

  143252.             ** "col IS NULL" expression matches twice as many rows 

  143253.             ** as (col=?). */

  143254.             pNew->nOut += 10;

  143255.           }

  143256.         }

  143257.       }

  143258.     }

  143259. 

  143260.     /* Set rCostIdx to the cost of visiting selected rows in index. Add

  143261.     ** it to pNew->rRun, which is currently set to the cost of the index

  143262.     ** seek only. Then, if this is a non-covering index, add the cost of

  143263.     ** visiting the rows in the main table.  */

  143264.     rCostIdx = pNew->nOut + 1 + (15*pProbe->szIdxRow)/pSrc->pTab->szTabRow;

  143265.     pNew->rRun = sqlite3LogEstAdd(rLogSize, rCostIdx);

  143266.     if( (pNew->wsFlags & (WHERE_IDX_ONLY|WHERE_IPK))==0 ){

  143267.       pNew->rRun = sqlite3LogEstAdd(pNew->rRun, pNew->nOut + 16);

  143268.     }

  143269.     ApplyCostMultiplier(pNew->rRun, pProbe->pTable->costMult);

  143270. 

  143271.     nOutUnadjusted = pNew->nOut;

  143272.     pNew->rRun += nInMul + nIn;

  143273.     pNew->nOut += nInMul + nIn;

  143274.     whereLoopOutputAdjust(pBuilder->pWC, pNew, rSize);

  143275.     rc = whereLoopInsert(pBuilder, pNew);

  143276. 

  143277.     if( pNew->wsFlags & WHERE_COLUMN_RANGE ){

  143278.       pNew->nOut = saved_nOut;

  143279.     }else{

  143280.       pNew->nOut = nOutUnadjusted;

  143281.     }

  143282. 

  143283.     if( (pNew->wsFlags & WHERE_TOP_LIMIT)==0

  143284.      && pNew->u.btree.nEq<pProbe->nColumn

  143285.     ){

  143286.       whereLoopAddBtreeIndex(pBuilder, pSrc, pProbe, nInMul+nIn);

  143287.     }

  143288.     pNew->nOut = saved_nOut;

  143289. #ifdef SQLITE_ENABLE_STAT3_OR_STAT4

  143290.     pBuilder->nRecValid = nRecValid;

  143291. #endif

  143292.   }

  143293.   pNew->prereq = saved_prereq;

  143294.   pNew->u.btree.nEq = saved_nEq;

  143295.   pNew->u.btree.nBtm = saved_nBtm;

  143296.   pNew->u.btree.nTop = saved_nTop;

  143297.   pNew->nSkip = saved_nSkip;

  143298.   pNew->wsFlags = saved_wsFlags;

  143299.   pNew->nOut = saved_nOut;

  143300.   pNew->nLTerm = saved_nLTerm;

  143301. 

  143302.   /* Consider using a skip-scan if there are no WHERE clause constraints

  143303.   ** available for the left-most terms of the index, and if the average

  143304.   ** number of repeats in the left-most terms is at least 18. 

  143305.   **

  143306.   ** The magic number 18 is selected on the basis that scanning 17 rows

  143307.   ** is almost always quicker than an index seek (even though if the index

  143308.   ** contains fewer than 2^17 rows we assume otherwise in other parts of

  143309.   ** the code). And, even if it is not, it should not be too much slower. 

  143310.   ** On the other hand, the extra seeks could end up being significantly

  143311.   ** more expensive.  */

  143312.   assert( 42==sqlite3LogEst(18) );

  143313.   if( saved_nEq==saved_nSkip

  143314.    && saved_nEq+1<pProbe->nKeyCol

  143315.    && pProbe->noSkipScan==0

  143316.    && OptimizationEnabled(db, SQLITE_SkipScan)

  143317.    && pProbe->aiRowLogEst[saved_nEq+1]>=42  /* TUNING: Minimum for skip-scan */

  143318.    && (rc = whereLoopResize(db, pNew, pNew->nLTerm+1))==SQLITE_OK

  143319.   ){

  143320.     LogEst nIter;

  143321.     pNew->u.btree.nEq++;

  143322.     pNew->nSkip++;

  143323.     pNew->aLTerm[pNew->nLTerm++] = 0;

  143324.     pNew->wsFlags |= WHERE_SKIPSCAN;

  143325.     nIter = pProbe->aiRowLogEst[saved_nEq] - pProbe->aiRowLogEst[saved_nEq+1];

  143326.     pNew->nOut -= nIter;

  143327.     /* TUNING:  Because uncertainties in the estimates for skip-scan queries,

  143328.     ** add a 1.375 fudge factor to make skip-scan slightly less likely. */

  143329.     nIter += 5;

  143330.     whereLoopAddBtreeIndex(pBuilder, pSrc, pProbe, nIter + nInMul);

  143331.     pNew->nOut = saved_nOut;

  143332.     pNew->u.btree.nEq = saved_nEq;

  143333.     pNew->nSkip = saved_nSkip;

  143334.     pNew->wsFlags = saved_wsFlags;

  143335.   }

  143336. 

  143337.   WHERETRACE(0x800, ("END %s.addBtreeIdx(%s), nEq=%d, rc=%d\n",

  143338.                       pProbe->pTable->zName, pProbe->zName, saved_nEq, rc));

  143339.   return rc;

  143340. }

  143341. 

  143342. /*

  143343. ** Return True if it is possible that pIndex might be useful in

  143344. ** implementing the ORDER BY clause in pBuilder.

  143345. **

  143346. ** Return False if pBuilder does not contain an ORDER BY clause or

  143347. ** if there is no way for pIndex to be useful in implementing that

  143348. ** ORDER BY clause.

  143349. */

  143350. static int indexMightHelpWithOrderBy(

  143351.   WhereLoopBuilder *pBuilder,

  143352.   Index *pIndex,

  143353.   int iCursor

  143354. ){

  143355.   ExprList *pOB;

  143356.   ExprList *aColExpr;

  143357.   int ii, jj;

  143358. 

  143359.   if( pIndex->bUnordered ) return 0;

  143360.   if( (pOB = pBuilder->pWInfo->pOrderBy)==0 ) return 0;

  143361.   for(ii=0; ii<pOB->nExpr; ii++){

  143362.     Expr *pExpr = sqlite3ExprSkipCollate(pOB->a[ii].pExpr);

  143363.     if( pExpr->op==TK_COLUMN && pExpr->iTable==iCursor ){

  143364.       if( pExpr->iColumn<0 ) return 1;

  143365.       for(jj=0; jj<pIndex->nKeyCol; jj++){

  143366.         if( pExpr->iColumn==pIndex->aiColumn[jj] ) return 1;

  143367.       }

  143368.     }else if( (aColExpr = pIndex->aColExpr)!=0 ){

  143369.       for(jj=0; jj<pIndex->nKeyCol; jj++){

  143370.         if( pIndex->aiColumn[jj]!=XN_EXPR ) continue;

  143371.         if( sqlite3ExprCompareSkip(pExpr,aColExpr->a[jj].pExpr,iCursor)==0 ){

  143372.           return 1;

  143373.         }

  143374.       }

  143375.     }

  143376.   }

  143377.   return 0;

  143378. }

  143379. 

  143380. /* Check to see if a partial index with pPartIndexWhere can be used

  143381. ** in the current query.  Return true if it can be and false if not.

  143382. */

  143383. static int whereUsablePartialIndex(int iTab, WhereClause *pWC, Expr *pWhere){

  143384.   int i;

  143385.   WhereTerm *pTerm;

  143386.   Parse *pParse = pWC->pWInfo->pParse;

  143387.   while( pWhere->op==TK_AND ){

  143388.     if( !whereUsablePartialIndex(iTab,pWC,pWhere->pLeft) ) return 0;

  143389.     pWhere = pWhere->pRight;

  143390.   }

  143391.   if( pParse->db->flags & SQLITE_EnableQPSG ) pParse = 0;

  143392.   for(i=0, pTerm=pWC->a; i<pWC->nTerm; i++, pTerm++){

  143393.     Expr *pExpr = pTerm->pExpr;

  143394.     if( (!ExprHasProperty(pExpr, EP_FromJoin) || pExpr->iRightJoinTable==iTab)

  143395.      && sqlite3ExprImpliesExpr(pParse, pExpr, pWhere, iTab) 

  143396.     ){

  143397.       return 1;

  143398.     }

  143399.   }

  143400.   return 0;

  143401. }

  143402. 

  143403. /*

  143404. ** Add all WhereLoop objects for a single table of the join where the table

  143405. ** is identified by pBuilder->pNew->iTab.  That table is guaranteed to be

  143406. ** a b-tree table, not a virtual table.

  143407. **

  143408. ** The costs (WhereLoop.rRun) of the b-tree loops added by this function

  143409. ** are calculated as follows:

  143410. **

  143411. ** For a full scan, assuming the table (or index) contains nRow rows:

  143412. **

  143413. **     cost = nRow * 3.0                    // full-table scan

  143414. **     cost = nRow * K                      // scan of covering index

  143415. **     cost = nRow * (K+3.0)                // scan of non-covering index

  143416. **

  143417. ** where K is a value between 1.1 and 3.0 set based on the relative 

  143418. ** estimated average size of the index and table records.

  143419. **

  143420. ** For an index scan, where nVisit is the number of index rows visited

  143421. ** by the scan, and nSeek is the number of seek operations required on 

  143422. ** the index b-tree:

  143423. **

  143424. **     cost = nSeek * (log(nRow) + K * nVisit)          // covering index

  143425. **     cost = nSeek * (log(nRow) + (K+3.0) * nVisit)    // non-covering index

  143426. **

  143427. ** Normally, nSeek is 1. nSeek values greater than 1 come about if the 

  143428. ** WHERE clause includes "x IN (....)" terms used in place of "x=?". Or when 

  143429. ** implicit "x IN (SELECT x FROM tbl)" terms are added for skip-scans.

  143430. **

  143431. ** The estimated values (nRow, nVisit, nSeek) often contain a large amount

  143432. ** of uncertainty.  For this reason, scoring is designed to pick plans that

  143433. ** "do the least harm" if the estimates are inaccurate.  For example, a

  143434. ** log(nRow) factor is omitted from a non-covering index scan in order to

  143435. ** bias the scoring in favor of using an index, since the worst-case

  143436. ** performance of using an index is far better than the worst-case performance

  143437. ** of a full table scan.

  143438. */

  143439. static int whereLoopAddBtree(

  143440.   WhereLoopBuilder *pBuilder, /* WHERE clause information */

  143441.   Bitmask mPrereq             /* Extra prerequesites for using this table */

  143442. ){

  143443.   WhereInfo *pWInfo;          /* WHERE analysis context */

  143444.   Index *pProbe;              /* An index we are evaluating */

  143445.   Index sPk;                  /* A fake index object for the primary key */

  143446.   LogEst aiRowEstPk[2];       /* The aiRowLogEst[] value for the sPk index */

  143447.   i16 aiColumnPk = -1;        /* The aColumn[] value for the sPk index */

  143448.   SrcList *pTabList;          /* The FROM clause */

  143449.   struct SrcList_item *pSrc;  /* The FROM clause btree term to add */

  143450.   WhereLoop *pNew;            /* Template WhereLoop object */

  143451.   int rc = SQLITE_OK;         /* Return code */

  143452.   int iSortIdx = 1;           /* Index number */

  143453.   int b;                      /* A boolean value */

  143454.   LogEst rSize;               /* number of rows in the table */

  143455.   LogEst rLogSize;            /* Logarithm of the number of rows in the table */

  143456.   WhereClause *pWC;           /* The parsed WHERE clause */

  143457.   Table *pTab;                /* Table being queried */

  143458.   

  143459.   pNew = pBuilder->pNew;

  143460.   pWInfo = pBuilder->pWInfo;

  143461.   pTabList = pWInfo->pTabList;

  143462.   pSrc = pTabList->a + pNew->iTab;

  143463.   pTab = pSrc->pTab;

  143464.   pWC = pBuilder->pWC;

  143465.   assert( !IsVirtual(pSrc->pTab) );

  143466. 

  143467.   if( pSrc->pIBIndex ){

  143468.     /* An INDEXED BY clause specifies a particular index to use */

  143469.     pProbe = pSrc->pIBIndex;

  143470.   }else if( !HasRowid(pTab) ){

  143471.     pProbe = pTab->pIndex;

  143472.   }else{

  143473.     /* There is no INDEXED BY clause.  Create a fake Index object in local

  143474.     ** variable sPk to represent the rowid primary key index.  Make this

  143475.     ** fake index the first in a chain of Index objects with all of the real

  143476.     ** indices to follow */

  143477.     Index *pFirst;                  /* First of real indices on the table */

  143478.     memset(&sPk, 0, sizeof(Index));

  143479.     sPk.nKeyCol = 1;

  143480.     sPk.nColumn = 1;

  143481.     sPk.aiColumn = &aiColumnPk;

  143482.     sPk.aiRowLogEst = aiRowEstPk;

  143483.     sPk.onError = OE_Replace;

  143484.     sPk.pTable = pTab;

  143485.     sPk.szIdxRow = pTab->szTabRow;

  143486.     sPk.idxType = SQLITE_IDXTYPE_IPK;

  143487.     aiRowEstPk[0] = pTab->nRowLogEst;

  143488.     aiRowEstPk[1] = 0;

  143489.     pFirst = pSrc->pTab->pIndex;

  143490.     if( pSrc->fg.notIndexed==0 ){

  143491.       /* The real indices of the table are only considered if the

  143492.       ** NOT INDEXED qualifier is omitted from the FROM clause */

  143493.       sPk.pNext = pFirst;

  143494.     }

  143495.     pProbe = &sPk;

  143496.   }

  143497.   rSize = pTab->nRowLogEst;

  143498.   rLogSize = estLog(rSize);

  143499. 

  143500. #ifndef SQLITE_OMIT_AUTOMATIC_INDEX

  143501.   /* Automatic indexes */

  143502.   if( !pBuilder->pOrSet      /* Not part of an OR optimization */

  143503.    && (pWInfo->wctrlFlags & WHERE_OR_SUBCLAUSE)==0

  143504.    && (pWInfo->pParse->db->flags & SQLITE_AutoIndex)!=0

  143505.    && pSrc->pIBIndex==0      /* Has no INDEXED BY clause */

  143506.    && !pSrc->fg.notIndexed   /* Has no NOT INDEXED clause */

  143507.    && HasRowid(pTab)         /* Not WITHOUT ROWID table. (FIXME: Why not?) */

  143508.    && !pSrc->fg.isCorrelated /* Not a correlated subquery */

  143509.    && !pSrc->fg.isRecursive  /* Not a recursive common table expression. */

  143510.   ){

  143511.     /* Generate auto-index WhereLoops */

  143512.     WhereTerm *pTerm;

  143513.     WhereTerm *pWCEnd = pWC->a + pWC->nTerm;

  143514.     for(pTerm=pWC->a; rc==SQLITE_OK && pTerm<pWCEnd; pTerm++){

  143515.       if( pTerm->prereqRight & pNew->maskSelf ) continue;

  143516.       if( termCanDriveIndex(pTerm, pSrc, 0) ){

  143517.         pNew->u.btree.nEq = 1;

  143518.         pNew->nSkip = 0;

  143519.         pNew->u.btree.pIndex = 0;

  143520.         pNew->nLTerm = 1;

  143521.         pNew->aLTerm[0] = pTerm;

  143522.         /* TUNING: One-time cost for computing the automatic index is

  143523.         ** estimated to be X*N*log2(N) where N is the number of rows in

  143524.         ** the table being indexed and where X is 7 (LogEst=28) for normal

  143525.         ** tables or 0.5 (LogEst=-10) for views and subqueries.  The value

  143526.         ** of X is smaller for views and subqueries so that the query planner

  143527.         ** will be more aggressive about generating automatic indexes for

  143528.         ** those objects, since there is no opportunity to add schema

  143529.         ** indexes on subqueries and views. */

  143530.         pNew->rSetup = rLogSize + rSize;

  143531.         if( pTab->pSelect==0 && (pTab->tabFlags & TF_Ephemeral)==0 ){

  143532.           pNew->rSetup += 28;

  143533.         }else{

  143534.           pNew->rSetup -= 10;

  143535.         }

  143536.         ApplyCostMultiplier(pNew->rSetup, pTab->costMult);

  143537.         if( pNew->rSetup<0 ) pNew->rSetup = 0;

  143538.         /* TUNING: Each index lookup yields 20 rows in the table.  This

  143539.         ** is more than the usual guess of 10 rows, since we have no way

  143540.         ** of knowing how selective the index will ultimately be.  It would

  143541.         ** not be unreasonable to make this value much larger. */

  143542.         pNew->nOut = 43;  assert( 43==sqlite3LogEst(20) );

  143543.         pNew->rRun = sqlite3LogEstAdd(rLogSize,pNew->nOut);

  143544.         pNew->wsFlags = WHERE_AUTO_INDEX;

  143545.         pNew->prereq = mPrereq | pTerm->prereqRight;

  143546.         rc = whereLoopInsert(pBuilder, pNew);

  143547.       }

  143548.     }

  143549.   }

  143550. #endif /* SQLITE_OMIT_AUTOMATIC_INDEX */

  143551. 

  143552.   /* Loop over all indices. If there was an INDEXED BY clause, then only 

  143553.   ** consider index pProbe.  */

  143554.   for(; rc==SQLITE_OK && pProbe; 

  143555.       pProbe=(pSrc->pIBIndex ? 0 : pProbe->pNext), iSortIdx++

  143556.   ){

  143557.     if( pProbe->pPartIdxWhere!=0

  143558.      && !whereUsablePartialIndex(pSrc->iCursor, pWC, pProbe->pPartIdxWhere) ){

  143559.       testcase( pNew->iTab!=pSrc->iCursor );  /* See ticket [98d973b8f5] */

  143560.       continue;  /* Partial index inappropriate for this query */

  143561.     }

  143562.     if( pProbe->bNoQuery ) continue;

  143563.     rSize = pProbe->aiRowLogEst[0];

  143564.     pNew->u.btree.nEq = 0;

  143565.     pNew->u.btree.nBtm = 0;

  143566.     pNew->u.btree.nTop = 0;

  143567.     pNew->nSkip = 0;

  143568.     pNew->nLTerm = 0;

  143569.     pNew->iSortIdx = 0;

  143570.     pNew->rSetup = 0;

  143571.     pNew->prereq = mPrereq;

  143572.     pNew->nOut = rSize;

  143573.     pNew->u.btree.pIndex = pProbe;

  143574.     b = indexMightHelpWithOrderBy(pBuilder, pProbe, pSrc->iCursor);

  143575.     /* The ONEPASS_DESIRED flags never occurs together with ORDER BY */

  143576.     assert( (pWInfo->wctrlFlags & WHERE_ONEPASS_DESIRED)==0 || b==0 );

  143577.     if( pProbe->idxType==SQLITE_IDXTYPE_IPK ){

  143578.       /* Integer primary key index */

  143579.       pNew->wsFlags = WHERE_IPK;

  143580. 

  143581.       /* Full table scan */

  143582.       pNew->iSortIdx = b ? iSortIdx : 0;

  143583.       /* TUNING: Cost of full table scan is (N*3.0). */

  143584.       pNew->rRun = rSize + 16;

  143585.       ApplyCostMultiplier(pNew->rRun, pTab->costMult);

  143586.       whereLoopOutputAdjust(pWC, pNew, rSize);

  143587.       rc = whereLoopInsert(pBuilder, pNew);

  143588.       pNew->nOut = rSize;

  143589.       if( rc ) break;

  143590.     }else{

  143591.       Bitmask m;

  143592.       if( pProbe->isCovering ){

  143593.         pNew->wsFlags = WHERE_IDX_ONLY | WHERE_INDEXED;

  143594.         m = 0;

  143595.       }else{

  143596.         m = pSrc->colUsed & pProbe->colNotIdxed;

  143597.         pNew->wsFlags = (m==0) ? (WHERE_IDX_ONLY|WHERE_INDEXED) : WHERE_INDEXED;

  143598.       }

  143599. 

  143600.       /* Full scan via index */

  143601.       if( b

  143602.        || !HasRowid(pTab)

  143603.        || pProbe->pPartIdxWhere!=0

  143604.        || ( m==0

  143605.          && pProbe->bUnordered==0

  143606.          && (pProbe->szIdxRow<pTab->szTabRow)

  143607.          && (pWInfo->wctrlFlags & WHERE_ONEPASS_DESIRED)==0

  143608.          && sqlite3GlobalConfig.bUseCis

  143609.          && OptimizationEnabled(pWInfo->pParse->db, SQLITE_CoverIdxScan)

  143610.           )

  143611.       ){

  143612.         pNew->iSortIdx = b ? iSortIdx : 0;

  143613. 

  143614.         /* The cost of visiting the index rows is N*K, where K is

  143615.         ** between 1.1 and 3.0, depending on the relative sizes of the

  143616.         ** index and table rows. */

  143617.         pNew->rRun = rSize + 1 + (15*pProbe->szIdxRow)/pTab->szTabRow;

  143618.         if( m!=0 ){

  143619.           /* If this is a non-covering index scan, add in the cost of

  143620.           ** doing table lookups.  The cost will be 3x the number of

  143621.           ** lookups.  Take into account WHERE clause terms that can be

  143622.           ** satisfied using just the index, and that do not require a

  143623.           ** table lookup. */

  143624.           LogEst nLookup = rSize + 16;  /* Base cost:  N*3 */

  143625.           int ii;

  143626.           int iCur = pSrc->iCursor;

  143627.           WhereClause *pWC2 = &pWInfo->sWC;

  143628.           for(ii=0; ii<pWC2->nTerm; ii++){

  143629.             WhereTerm *pTerm = &pWC2->a[ii];

  143630.             if( !sqlite3ExprCoveredByIndex(pTerm->pExpr, iCur, pProbe) ){

  143631.               break;

  143632.             }

  143633.             /* pTerm can be evaluated using just the index.  So reduce

  143634.             ** the expected number of table lookups accordingly */

  143635.             if( pTerm->truthProb<=0 ){

  143636.               nLookup += pTerm->truthProb;

  143637.             }else{

  143638.               nLookup--;

  143639.               if( pTerm->eOperator & (WO_EQ|WO_IS) ) nLookup -= 19;

  143640.             }

  143641.           }

  143642.           

  143643.           pNew->rRun = sqlite3LogEstAdd(pNew->rRun, nLookup);

  143644.         }

  143645.         ApplyCostMultiplier(pNew->rRun, pTab->costMult);

  143646.         whereLoopOutputAdjust(pWC, pNew, rSize);

  143647.         rc = whereLoopInsert(pBuilder, pNew);

  143648.         pNew->nOut = rSize;

  143649.         if( rc ) break;

  143650.       }

  143651.     }

  143652. 

  143653.     pBuilder->bldFlags = 0;

  143654.     rc = whereLoopAddBtreeIndex(pBuilder, pSrc, pProbe, 0);

  143655.     if( pBuilder->bldFlags==SQLITE_BLDF_INDEXED ){

  143656.       /* If a non-unique index is used, or if a prefix of the key for

  143657.       ** unique index is used (making the index functionally non-unique)

  143658.       ** then the sqlite_stat1 data becomes important for scoring the

  143659.       ** plan */

  143660.       pTab->tabFlags |= TF_StatsUsed;

  143661.     }

  143662. #ifdef SQLITE_ENABLE_STAT3_OR_STAT4

  143663.     sqlite3Stat4ProbeFree(pBuilder->pRec);

  143664.     pBuilder->nRecValid = 0;

  143665.     pBuilder->pRec = 0;

  143666. #endif

  143667.   }

  143668.   return rc;

  143669. }

  143670. 

  143671. #ifndef SQLITE_OMIT_VIRTUALTABLE

  143672. 

  143673. /*

  143674. ** Argument pIdxInfo is already populated with all constraints that may

  143675. ** be used by the virtual table identified by pBuilder->pNew->iTab. This

  143676. ** function marks a subset of those constraints usable, invokes the

  143677. ** xBestIndex method and adds the returned plan to pBuilder.

  143678. **

  143679. ** A constraint is marked usable if:

  143680. **

  143681. **   * Argument mUsable indicates that its prerequisites are available, and

  143682. **

  143683. **   * It is not one of the operators specified in the mExclude mask passed

  143684. **     as the fourth argument (which in practice is either WO_IN or 0).

  143685. **

  143686. ** Argument mPrereq is a mask of tables that must be scanned before the

  143687. ** virtual table in question. These are added to the plans prerequisites

  143688. ** before it is added to pBuilder.

  143689. **

  143690. ** Output parameter *pbIn is set to true if the plan added to pBuilder

  143691. ** uses one or more WO_IN terms, or false otherwise.

  143692. */

  143693. static int whereLoopAddVirtualOne(

  143694.   WhereLoopBuilder *pBuilder,

  143695.   Bitmask mPrereq,                /* Mask of tables that must be used. */

  143696.   Bitmask mUsable,                /* Mask of usable tables */

  143697.   u16 mExclude,                   /* Exclude terms using these operators */

  143698.   sqlite3_index_info *pIdxInfo,   /* Populated object for xBestIndex */

  143699.   u16 mNoOmit,                    /* Do not omit these constraints */

  143700.   int *pbIn                       /* OUT: True if plan uses an IN(...) op */

  143701. ){

  143702.   WhereClause *pWC = pBuilder->pWC;

  143703.   struct sqlite3_index_constraint *pIdxCons;

  143704.   struct sqlite3_index_constraint_usage *pUsage = pIdxInfo->aConstraintUsage;

  143705.   int i;

  143706.   int mxTerm;

  143707.   int rc = SQLITE_OK;

  143708.   WhereLoop *pNew = pBuilder->pNew;

  143709.   Parse *pParse = pBuilder->pWInfo->pParse;

  143710.   struct SrcList_item *pSrc = &pBuilder->pWInfo->pTabList->a[pNew->iTab];

  143711.   int nConstraint = pIdxInfo->nConstraint;

  143712. 

  143713.   assert( (mUsable & mPrereq)==mPrereq );

  143714.   *pbIn = 0;

  143715.   pNew->prereq = mPrereq;

  143716. 

  143717.   /* Set the usable flag on the subset of constraints identified by 

  143718.   ** arguments mUsable and mExclude. */

  143719.   pIdxCons = *(struct sqlite3_index_constraint**)&pIdxInfo->aConstraint;

  143720.   for(i=0; i<nConstraint; i++, pIdxCons++){

  143721.     WhereTerm *pTerm = &pWC->a[pIdxCons->iTermOffset];

  143722.     pIdxCons->usable = 0;

  143723.     if( (pTerm->prereqRight & mUsable)==pTerm->prereqRight 

  143724.      && (pTerm->eOperator & mExclude)==0

  143725.     ){

  143726.       pIdxCons->usable = 1;

  143727.     }

  143728.   }

  143729. 

  143730.   /* Initialize the output fields of the sqlite3_index_info structure */

  143731.   memset(pUsage, 0, sizeof(pUsage[0])*nConstraint);

  143732.   assert( pIdxInfo->needToFreeIdxStr==0 );

  143733.   pIdxInfo->idxStr = 0;

  143734.   pIdxInfo->idxNum = 0;

  143735.   pIdxInfo->orderByConsumed = 0;

  143736.   pIdxInfo->estimatedCost = SQLITE_BIG_DBL / (double)2;

  143737.   pIdxInfo->estimatedRows = 25;

  143738.   pIdxInfo->idxFlags = 0;

  143739.   pIdxInfo->colUsed = (sqlite3_int64)pSrc->colUsed;

  143740. 

  143741.   /* Invoke the virtual table xBestIndex() method */

  143742.   rc = vtabBestIndex(pParse, pSrc->pTab, pIdxInfo);

  143743.   if( rc ){

  143744.     if( rc==SQLITE_CONSTRAINT ){

  143745.       /* If the xBestIndex method returns SQLITE_CONSTRAINT, that means

  143746.       ** that the particular combination of parameters provided is unusable.

  143747.       ** Make no entries in the loop table.

  143748.       */

  143749.       WHERETRACE(0xffff, ("  ^^^^--- non-viable plan rejected!\n"));

  143750.       return SQLITE_OK;

  143751.     }

  143752.     return rc;

  143753.   }

  143754. 

  143755.   mxTerm = -1;

  143756.   assert( pNew->nLSlot>=nConstraint );

  143757.   for(i=0; i<nConstraint; i++) pNew->aLTerm[i] = 0;

  143758.   pNew->u.vtab.omitMask = 0;

  143759.   pIdxCons = *(struct sqlite3_index_constraint**)&pIdxInfo->aConstraint;

  143760.   for(i=0; i<nConstraint; i++, pIdxCons++){

  143761.     int iTerm;

  143762.     if( (iTerm = pUsage[i].argvIndex - 1)>=0 ){

  143763.       WhereTerm *pTerm;

  143764.       int j = pIdxCons->iTermOffset;

  143765.       if( iTerm>=nConstraint

  143766.        || j<0

  143767.        || j>=pWC->nTerm

  143768.        || pNew->aLTerm[iTerm]!=0

  143769.        || pIdxCons->usable==0

  143770.       ){

  143771.         sqlite3ErrorMsg(pParse,"%s.xBestIndex malfunction",pSrc->pTab->zName);

  143772.         testcase( pIdxInfo->needToFreeIdxStr );

  143773.         return SQLITE_ERROR;

  143774.       }

  143775.       testcase( iTerm==nConstraint-1 );

  143776.       testcase( j==0 );

  143777.       testcase( j==pWC->nTerm-1 );

  143778.       pTerm = &pWC->a[j];

  143779.       pNew->prereq |= pTerm->prereqRight;

  143780.       assert( iTerm<pNew->nLSlot );

  143781.       pNew->aLTerm[iTerm] = pTerm;

  143782.       if( iTerm>mxTerm ) mxTerm = iTerm;

  143783.       testcase( iTerm==15 );

  143784.       testcase( iTerm==16 );

  143785.       if( iTerm<16 && pUsage[i].omit ) pNew->u.vtab.omitMask |= 1<<iTerm;

  143786.       if( (pTerm->eOperator & WO_IN)!=0 ){

  143787.         /* A virtual table that is constrained by an IN clause may not

  143788.         ** consume the ORDER BY clause because (1) the order of IN terms

  143789.         ** is not necessarily related to the order of output terms and

  143790.         ** (2) Multiple outputs from a single IN value will not merge

  143791.         ** together.  */

  143792.         pIdxInfo->orderByConsumed = 0;

  143793.         pIdxInfo->idxFlags &= ~SQLITE_INDEX_SCAN_UNIQUE;

  143794.         *pbIn = 1; assert( (mExclude & WO_IN)==0 );

  143795.       }

  143796.     }

  143797.   }

  143798.   pNew->u.vtab.omitMask &= ~mNoOmit;

  143799. 

  143800.   pNew->nLTerm = mxTerm+1;

  143801.   for(i=0; i<=mxTerm; i++){

  143802.     if( pNew->aLTerm[i]==0 ){

  143803.       /* The non-zero argvIdx values must be contiguous.  Raise an

  143804.       ** error if they are not */

  143805.       sqlite3ErrorMsg(pParse,"%s.xBestIndex malfunction",pSrc->pTab->zName);

  143806.       testcase( pIdxInfo->needToFreeIdxStr );

  143807.       return SQLITE_ERROR;

  143808.     }

  143809.   }

  143810.   assert( pNew->nLTerm<=pNew->nLSlot );

  143811.   pNew->u.vtab.idxNum = pIdxInfo->idxNum;

  143812.   pNew->u.vtab.needFree = pIdxInfo->needToFreeIdxStr;

  143813.   pIdxInfo->needToFreeIdxStr = 0;

  143814.   pNew->u.vtab.idxStr = pIdxInfo->idxStr;

  143815.   pNew->u.vtab.isOrdered = (i8)(pIdxInfo->orderByConsumed ?

  143816.       pIdxInfo->nOrderBy : 0);

  143817.   pNew->rSetup = 0;

  143818.   pNew->rRun = sqlite3LogEstFromDouble(pIdxInfo->estimatedCost);

  143819.   pNew->nOut = sqlite3LogEst(pIdxInfo->estimatedRows);

  143820. 

  143821.   /* Set the WHERE_ONEROW flag if the xBestIndex() method indicated

  143822.   ** that the scan will visit at most one row. Clear it otherwise. */

  143823.   if( pIdxInfo->idxFlags & SQLITE_INDEX_SCAN_UNIQUE ){

  143824.     pNew->wsFlags |= WHERE_ONEROW;

  143825.   }else{

  143826.     pNew->wsFlags &= ~WHERE_ONEROW;

  143827.   }

  143828.   rc = whereLoopInsert(pBuilder, pNew);

  143829.   if( pNew->u.vtab.needFree ){

  143830.     sqlite3_free(pNew->u.vtab.idxStr);

  143831.     pNew->u.vtab.needFree = 0;

  143832.   }

  143833.   WHERETRACE(0xffff, ("  bIn=%d prereqIn=%04llx prereqOut=%04llx\n",

  143834.                       *pbIn, (sqlite3_uint64)mPrereq,

  143835.                       (sqlite3_uint64)(pNew->prereq & ~mPrereq)));

  143836. 

  143837.   return rc;

  143838. }

  143839. 

  143840. /*

  143841. ** If this function is invoked from within an xBestIndex() callback, it

  143842. ** returns a pointer to a buffer containing the name of the collation

  143843. ** sequence associated with element iCons of the sqlite3_index_info.aConstraint

  143844. ** array. Or, if iCons is out of range or there is no active xBestIndex

  143845. ** call, return NULL.

  143846. */

  143847. SQLITE_API const char *sqlite3_vtab_collation(sqlite3_index_info *pIdxInfo, int iCons){

  143848.   HiddenIndexInfo *pHidden = (HiddenIndexInfo*)&pIdxInfo[1];

  143849.   const char *zRet = 0;

  143850.   if( iCons>=0 && iCons<pIdxInfo->nConstraint ){

  143851.     CollSeq *pC = 0;

  143852.     int iTerm = pIdxInfo->aConstraint[iCons].iTermOffset;

  143853.     Expr *pX = pHidden->pWC->a[iTerm].pExpr;

  143854.     if( pX->pLeft ){

  143855.       pC = sqlite3BinaryCompareCollSeq(pHidden->pParse, pX->pLeft, pX->pRight);

  143856.     }

  143857.     zRet = (pC ? pC->zName : sqlite3StrBINARY);

  143858.   }

  143859.   return zRet;

  143860. }

  143861. 

  143862. /*

  143863. ** Add all WhereLoop objects for a table of the join identified by

  143864. ** pBuilder->pNew->iTab.  That table is guaranteed to be a virtual table.

  143865. **

  143866. ** If there are no LEFT or CROSS JOIN joins in the query, both mPrereq and

  143867. ** mUnusable are set to 0. Otherwise, mPrereq is a mask of all FROM clause

  143868. ** entries that occur before the virtual table in the FROM clause and are

  143869. ** separated from it by at least one LEFT or CROSS JOIN. Similarly, the

  143870. ** mUnusable mask contains all FROM clause entries that occur after the

  143871. ** virtual table and are separated from it by at least one LEFT or 

  143872. ** CROSS JOIN. 

  143873. **

  143874. ** For example, if the query were:

  143875. **

  143876. **   ... FROM t1, t2 LEFT JOIN t3, t4, vt CROSS JOIN t5, t6;

  143877. **

  143878. ** then mPrereq corresponds to (t1, t2) and mUnusable to (t5, t6).

  143879. **

  143880. ** All the tables in mPrereq must be scanned before the current virtual 

  143881. ** table. So any terms for which all prerequisites are satisfied by 

  143882. ** mPrereq may be specified as "usable" in all calls to xBestIndex. 

  143883. ** Conversely, all tables in mUnusable must be scanned after the current

  143884. ** virtual table, so any terms for which the prerequisites overlap with

  143885. ** mUnusable should always be configured as "not-usable" for xBestIndex.

  143886. */

  143887. static int whereLoopAddVirtual(

  143888.   WhereLoopBuilder *pBuilder,  /* WHERE clause information */

  143889.   Bitmask mPrereq,             /* Tables that must be scanned before this one */

  143890.   Bitmask mUnusable            /* Tables that must be scanned after this one */

  143891. ){

  143892.   int rc = SQLITE_OK;          /* Return code */

  143893.   WhereInfo *pWInfo;           /* WHERE analysis context */

  143894.   Parse *pParse;               /* The parsing context */

  143895.   WhereClause *pWC;            /* The WHERE clause */

  143896.   struct SrcList_item *pSrc;   /* The FROM clause term to search */

  143897.   sqlite3_index_info *p;       /* Object to pass to xBestIndex() */

  143898.   int nConstraint;             /* Number of constraints in p */

  143899.   int bIn;                     /* True if plan uses IN(...) operator */

  143900.   WhereLoop *pNew;

  143901.   Bitmask mBest;               /* Tables used by best possible plan */

  143902.   u16 mNoOmit;

  143903. 

  143904.   assert( (mPrereq & mUnusable)==0 );

  143905.   pWInfo = pBuilder->pWInfo;

  143906.   pParse = pWInfo->pParse;

  143907.   pWC = pBuilder->pWC;

  143908.   pNew = pBuilder->pNew;

  143909.   pSrc = &pWInfo->pTabList->a[pNew->iTab];

  143910.   assert( IsVirtual(pSrc->pTab) );

  143911.   p = allocateIndexInfo(pParse, pWC, mUnusable, pSrc, pBuilder->pOrderBy, 

  143912.       &mNoOmit);

  143913.   if( p==0 ) return SQLITE_NOMEM_BKPT;

  143914.   pNew->rSetup = 0;

  143915.   pNew->wsFlags = WHERE_VIRTUALTABLE;

  143916.   pNew->nLTerm = 0;

  143917.   pNew->u.vtab.needFree = 0;

  143918.   nConstraint = p->nConstraint;

  143919.   if( whereLoopResize(pParse->db, pNew, nConstraint) ){

  143920.     sqlite3DbFree(pParse->db, p);

  143921.     return SQLITE_NOMEM_BKPT;

  143922.   }

  143923. 

  143924.   /* First call xBestIndex() with all constraints usable. */

  143925.   WHERETRACE(0x800, ("BEGIN %s.addVirtual()\n", pSrc->pTab->zName));

  143926.   WHERETRACE(0x40, ("  VirtualOne: all usable\n"));

  143927.   rc = whereLoopAddVirtualOne(pBuilder, mPrereq, ALLBITS, 0, p, mNoOmit, &bIn);

  143928. 

  143929.   /* If the call to xBestIndex() with all terms enabled produced a plan

  143930.   ** that does not require any source tables (IOW: a plan with mBest==0)

  143931.   ** and does not use an IN(...) operator, then there is no point in making 

  143932.   ** any further calls to xBestIndex() since they will all return the same

  143933.   ** result (if the xBestIndex() implementation is sane). */

  143934.   if( rc==SQLITE_OK && ((mBest = (pNew->prereq & ~mPrereq))!=0 || bIn) ){

  143935.     int seenZero = 0;             /* True if a plan with no prereqs seen */

  143936.     int seenZeroNoIN = 0;         /* Plan with no prereqs and no IN(...) seen */

  143937.     Bitmask mPrev = 0;

  143938.     Bitmask mBestNoIn = 0;

  143939. 

  143940.     /* If the plan produced by the earlier call uses an IN(...) term, call

  143941.     ** xBestIndex again, this time with IN(...) terms disabled. */

  143942.     if( bIn ){

  143943.       WHERETRACE(0x40, ("  VirtualOne: all usable w/o IN\n"));

  143944.       rc = whereLoopAddVirtualOne(

  143945.           pBuilder, mPrereq, ALLBITS, WO_IN, p, mNoOmit, &bIn);

  143946.       assert( bIn==0 );

  143947.       mBestNoIn = pNew->prereq & ~mPrereq;

  143948.       if( mBestNoIn==0 ){

  143949.         seenZero = 1;

  143950.         seenZeroNoIN = 1;

  143951.       }

  143952.     }

  143953. 

  143954.     /* Call xBestIndex once for each distinct value of (prereqRight & ~mPrereq) 

  143955.     ** in the set of terms that apply to the current virtual table.  */

  143956.     while( rc==SQLITE_OK ){

  143957.       int i;

  143958.       Bitmask mNext = ALLBITS;

  143959.       assert( mNext>0 );

  143960.       for(i=0; i<nConstraint; i++){

  143961.         Bitmask mThis = (

  143962.             pWC->a[p->aConstraint[i].iTermOffset].prereqRight & ~mPrereq

  143963.         );

  143964.         if( mThis>mPrev && mThis<mNext ) mNext = mThis;

  143965.       }

  143966.       mPrev = mNext;

  143967.       if( mNext==ALLBITS ) break;

  143968.       if( mNext==mBest || mNext==mBestNoIn ) continue;

  143969.       WHERETRACE(0x40, ("  VirtualOne: mPrev=%04llx mNext=%04llx\n",

  143970.                        (sqlite3_uint64)mPrev, (sqlite3_uint64)mNext));

  143971.       rc = whereLoopAddVirtualOne(

  143972.           pBuilder, mPrereq, mNext|mPrereq, 0, p, mNoOmit, &bIn);

  143973.       if( pNew->prereq==mPrereq ){

  143974.         seenZero = 1;

  143975.         if( bIn==0 ) seenZeroNoIN = 1;

  143976.       }

  143977.     }

  143978. 

  143979.     /* If the calls to xBestIndex() in the above loop did not find a plan

  143980.     ** that requires no source tables at all (i.e. one guaranteed to be

  143981.     ** usable), make a call here with all source tables disabled */

  143982.     if( rc==SQLITE_OK && seenZero==0 ){

  143983.       WHERETRACE(0x40, ("  VirtualOne: all disabled\n"));

  143984.       rc = whereLoopAddVirtualOne(

  143985.           pBuilder, mPrereq, mPrereq, 0, p, mNoOmit, &bIn);

  143986.       if( bIn==0 ) seenZeroNoIN = 1;

  143987.     }

  143988. 

  143989.     /* If the calls to xBestIndex() have so far failed to find a plan

  143990.     ** that requires no source tables at all and does not use an IN(...)

  143991.     ** operator, make a final call to obtain one here.  */

  143992.     if( rc==SQLITE_OK && seenZeroNoIN==0 ){

  143993.       WHERETRACE(0x40, ("  VirtualOne: all disabled and w/o IN\n"));

  143994.       rc = whereLoopAddVirtualOne(

  143995.           pBuilder, mPrereq, mPrereq, WO_IN, p, mNoOmit, &bIn);

  143996.     }

  143997.   }

  143998. 

  143999.   if( p->needToFreeIdxStr ) sqlite3_free(p->idxStr);

  144000.   sqlite3DbFreeNN(pParse->db, p);

  144001.   WHERETRACE(0x800, ("END %s.addVirtual(), rc=%d\n", pSrc->pTab->zName, rc));

  144002.   return rc;

  144003. }

  144004. #endif /* SQLITE_OMIT_VIRTUALTABLE */

  144005. 

  144006. /*

  144007. ** Add WhereLoop entries to handle OR terms.  This works for either

  144008. ** btrees or virtual tables.

  144009. */

  144010. static int whereLoopAddOr(

  144011.   WhereLoopBuilder *pBuilder, 

  144012.   Bitmask mPrereq, 

  144013.   Bitmask mUnusable

  144014. ){

  144015.   WhereInfo *pWInfo = pBuilder->pWInfo;

  144016.   WhereClause *pWC;

  144017.   WhereLoop *pNew;

  144018.   WhereTerm *pTerm, *pWCEnd;

  144019.   int rc = SQLITE_OK;

  144020.   int iCur;

  144021.   WhereClause tempWC;

  144022.   WhereLoopBuilder sSubBuild;

  144023.   WhereOrSet sSum, sCur;

  144024.   struct SrcList_item *pItem;

  144025.   

  144026.   pWC = pBuilder->pWC;

  144027.   pWCEnd = pWC->a + pWC->nTerm;

  144028.   pNew = pBuilder->pNew;

  144029.   memset(&sSum, 0, sizeof(sSum));

  144030.   pItem = pWInfo->pTabList->a + pNew->iTab;

  144031.   iCur = pItem->iCursor;

  144032. 

  144033.   for(pTerm=pWC->a; pTerm<pWCEnd && rc==SQLITE_OK; pTerm++){

  144034.     if( (pTerm->eOperator & WO_OR)!=0

  144035.      && (pTerm->u.pOrInfo->indexable & pNew->maskSelf)!=0 

  144036.     ){

  144037.       WhereClause * const pOrWC = &pTerm->u.pOrInfo->wc;

  144038.       WhereTerm * const pOrWCEnd = &pOrWC->a[pOrWC->nTerm];

  144039.       WhereTerm *pOrTerm;

  144040.       int once = 1;

  144041.       int i, j;

  144042.     

  144043.       sSubBuild = *pBuilder;

  144044.       sSubBuild.pOrderBy = 0;

  144045.       sSubBuild.pOrSet = &sCur;

  144046. 

  144047.       WHERETRACE(0x200, ("Begin processing OR-clause %p\n", pTerm));

  144048.       for(pOrTerm=pOrWC->a; pOrTerm<pOrWCEnd; pOrTerm++){

  144049.         if( (pOrTerm->eOperator & WO_AND)!=0 ){

  144050.           sSubBuild.pWC = &pOrTerm->u.pAndInfo->wc;

  144051.         }else if( pOrTerm->leftCursor==iCur ){

  144052.           tempWC.pWInfo = pWC->pWInfo;

  144053.           tempWC.pOuter = pWC;

  144054.           tempWC.op = TK_AND;

  144055.           tempWC.nTerm = 1;

  144056.           tempWC.a = pOrTerm;

  144057.           sSubBuild.pWC = &tempWC;

  144058.         }else{

  144059.           continue;

  144060.         }

  144061.         sCur.n = 0;

  144062. #ifdef WHERETRACE_ENABLED

  144063.         WHERETRACE(0x200, ("OR-term %d of %p has %d subterms:\n", 

  144064.                    (int)(pOrTerm-pOrWC->a), pTerm, sSubBuild.pWC->nTerm));

  144065.         if( sqlite3WhereTrace & 0x400 ){

  144066.           sqlite3WhereClausePrint(sSubBuild.pWC);

  144067.         }

  144068. #endif

  144069. #ifndef SQLITE_OMIT_VIRTUALTABLE

  144070.         if( IsVirtual(pItem->pTab) ){

  144071.           rc = whereLoopAddVirtual(&sSubBuild, mPrereq, mUnusable);

  144072.         }else

  144073. #endif

  144074.         {

  144075.           rc = whereLoopAddBtree(&sSubBuild, mPrereq);

  144076.         }

  144077.         if( rc==SQLITE_OK ){

  144078.           rc = whereLoopAddOr(&sSubBuild, mPrereq, mUnusable);

  144079.         }

  144080.         assert( rc==SQLITE_OK || sCur.n==0 );

  144081.         if( sCur.n==0 ){

  144082.           sSum.n = 0;

  144083.           break;

  144084.         }else if( once ){

  144085.           whereOrMove(&sSum, &sCur);

  144086.           once = 0;

  144087.         }else{

  144088.           WhereOrSet sPrev;

  144089.           whereOrMove(&sPrev, &sSum);

  144090.           sSum.n = 0;

  144091.           for(i=0; i<sPrev.n; i++){

  144092.             for(j=0; j<sCur.n; j++){

  144093.               whereOrInsert(&sSum, sPrev.a[i].prereq | sCur.a[j].prereq,

  144094.                             sqlite3LogEstAdd(sPrev.a[i].rRun, sCur.a[j].rRun),

  144095.                             sqlite3LogEstAdd(sPrev.a[i].nOut, sCur.a[j].nOut));

  144096.             }

  144097.           }

  144098.         }

  144099.       }

  144100.       pNew->nLTerm = 1;

  144101.       pNew->aLTerm[0] = pTerm;

  144102.       pNew->wsFlags = WHERE_MULTI_OR;

  144103.       pNew->rSetup = 0;

  144104.       pNew->iSortIdx = 0;

  144105.       memset(&pNew->u, 0, sizeof(pNew->u));

  144106.       for(i=0; rc==SQLITE_OK && i<sSum.n; i++){

  144107.         /* TUNING: Currently sSum.a[i].rRun is set to the sum of the costs

  144108.         ** of all sub-scans required by the OR-scan. However, due to rounding

  144109.         ** errors, it may be that the cost of the OR-scan is equal to its

  144110.         ** most expensive sub-scan. Add the smallest possible penalty 

  144111.         ** (equivalent to multiplying the cost by 1.07) to ensure that 

  144112.         ** this does not happen. Otherwise, for WHERE clauses such as the

  144113.         ** following where there is an index on "y":

  144114.         **

  144115.         **     WHERE likelihood(x=?, 0.99) OR y=?

  144116.         **

  144117.         ** the planner may elect to "OR" together a full-table scan and an

  144118.         ** index lookup. And other similarly odd results.  */

  144119.         pNew->rRun = sSum.a[i].rRun + 1;

  144120.         pNew->nOut = sSum.a[i].nOut;

  144121.         pNew->prereq = sSum.a[i].prereq;

  144122.         rc = whereLoopInsert(pBuilder, pNew);

  144123.       }

  144124.       WHERETRACE(0x200, ("End processing OR-clause %p\n", pTerm));

  144125.     }

  144126.   }

  144127.   return rc;

  144128. }

  144129. 

  144130. /*

  144131. ** Add all WhereLoop objects for all tables 

  144132. */

  144133. static int whereLoopAddAll(WhereLoopBuilder *pBuilder){

  144134.   WhereInfo *pWInfo = pBuilder->pWInfo;

  144135.   Bitmask mPrereq = 0;

  144136.   Bitmask mPrior = 0;

  144137.   int iTab;

  144138.   SrcList *pTabList = pWInfo->pTabList;

  144139.   struct SrcList_item *pItem;

  144140.   struct SrcList_item *pEnd = &pTabList->a[pWInfo->nLevel];

  144141.   sqlite3 *db = pWInfo->pParse->db;

  144142.   int rc = SQLITE_OK;

  144143.   WhereLoop *pNew;

  144144.   u8 priorJointype = 0;

  144145. 

  144146.   /* Loop over the tables in the join, from left to right */

  144147.   pNew = pBuilder->pNew;

  144148.   whereLoopInit(pNew);

  144149.   pBuilder->iPlanLimit = SQLITE_QUERY_PLANNER_LIMIT;

  144150.   for(iTab=0, pItem=pTabList->a; pItem<pEnd; iTab++, pItem++){

  144151.     Bitmask mUnusable = 0;

  144152.     pNew->iTab = iTab;

  144153.     pBuilder->iPlanLimit += SQLITE_QUERY_PLANNER_LIMIT_INCR;

  144154.     pNew->maskSelf = sqlite3WhereGetMask(&pWInfo->sMaskSet, pItem->iCursor);

  144155.     if( ((pItem->fg.jointype|priorJointype) & (JT_LEFT|JT_CROSS))!=0 ){

  144156.       /* This condition is true when pItem is the FROM clause term on the

  144157.       ** right-hand-side of a LEFT or CROSS JOIN.  */

  144158.       mPrereq = mPrior;

  144159.     }

  144160.     priorJointype = pItem->fg.jointype;

  144161. #ifndef SQLITE_OMIT_VIRTUALTABLE

  144162.     if( IsVirtual(pItem->pTab) ){

  144163.       struct SrcList_item *p;

  144164.       for(p=&pItem[1]; p<pEnd; p++){

  144165.         if( mUnusable || (p->fg.jointype & (JT_LEFT|JT_CROSS)) ){

  144166.           mUnusable |= sqlite3WhereGetMask(&pWInfo->sMaskSet, p->iCursor);

  144167.         }

  144168.       }

  144169.       rc = whereLoopAddVirtual(pBuilder, mPrereq, mUnusable);

  144170.     }else

  144171. #endif /* SQLITE_OMIT_VIRTUALTABLE */

  144172.     {

  144173.       rc = whereLoopAddBtree(pBuilder, mPrereq);

  144174.     }

  144175.     if( rc==SQLITE_OK && pBuilder->pWC->hasOr ){

  144176.       rc = whereLoopAddOr(pBuilder, mPrereq, mUnusable);

  144177.     }

  144178.     mPrior |= pNew->maskSelf;

  144179.     if( rc || db->mallocFailed ){

  144180.       if( rc==SQLITE_DONE ){

  144181.         /* We hit the query planner search limit set by iPlanLimit */

  144182.         sqlite3_log(SQLITE_WARNING, "abbreviated query algorithm search");

  144183.         rc = SQLITE_OK;

  144184.       }else{

  144185.         break;

  144186.       }

  144187.     }

  144188.   }

  144189. 

  144190.   whereLoopClear(db, pNew);

  144191.   return rc;

  144192. }

  144193. 

  144194. /*

  144195. ** Examine a WherePath (with the addition of the extra WhereLoop of the 6th

  144196. ** parameters) to see if it outputs rows in the requested ORDER BY

  144197. ** (or GROUP BY) without requiring a separate sort operation.  Return N:

  144198. ** 

  144199. **   N>0:   N terms of the ORDER BY clause are satisfied

  144200. **   N==0:  No terms of the ORDER BY clause are satisfied

  144201. **   N<0:   Unknown yet how many terms of ORDER BY might be satisfied.   

  144202. **

  144203. ** Note that processing for WHERE_GROUPBY and WHERE_DISTINCTBY is not as

  144204. ** strict.  With GROUP BY and DISTINCT the only requirement is that

  144205. ** equivalent rows appear immediately adjacent to one another.  GROUP BY

  144206. ** and DISTINCT do not require rows to appear in any particular order as long

  144207. ** as equivalent rows are grouped together.  Thus for GROUP BY and DISTINCT

  144208. ** the pOrderBy terms can be matched in any order.  With ORDER BY, the 

  144209. ** pOrderBy terms must be matched in strict left-to-right order.

  144210. */

  144211. static i8 wherePathSatisfiesOrderBy(

  144212.   WhereInfo *pWInfo,    /* The WHERE clause */

  144213.   ExprList *pOrderBy,   /* ORDER BY or GROUP BY or DISTINCT clause to check */

  144214.   WherePath *pPath,     /* The WherePath to check */

  144215.   u16 wctrlFlags,       /* WHERE_GROUPBY or _DISTINCTBY or _ORDERBY_LIMIT */

  144216.   u16 nLoop,            /* Number of entries in pPath->aLoop[] */

  144217.   WhereLoop *pLast,     /* Add this WhereLoop to the end of pPath->aLoop[] */

  144218.   Bitmask *pRevMask     /* OUT: Mask of WhereLoops to run in reverse order */

  144219. ){

  144220.   u8 revSet;            /* True if rev is known */

  144221.   u8 rev;               /* Composite sort order */

  144222.   u8 revIdx;            /* Index sort order */

  144223.   u8 isOrderDistinct;   /* All prior WhereLoops are order-distinct */

  144224.   u8 distinctColumns;   /* True if the loop has UNIQUE NOT NULL columns */

  144225.   u8 isMatch;           /* iColumn matches a term of the ORDER BY clause */

  144226.   u16 eqOpMask;         /* Allowed equality operators */

  144227.   u16 nKeyCol;          /* Number of key columns in pIndex */

  144228.   u16 nColumn;          /* Total number of ordered columns in the index */

  144229.   u16 nOrderBy;         /* Number terms in the ORDER BY clause */

  144230.   int iLoop;            /* Index of WhereLoop in pPath being processed */

  144231.   int i, j;             /* Loop counters */

  144232.   int iCur;             /* Cursor number for current WhereLoop */

  144233.   int iColumn;          /* A column number within table iCur */

  144234.   WhereLoop *pLoop = 0; /* Current WhereLoop being processed. */

  144235.   WhereTerm *pTerm;     /* A single term of the WHERE clause */

  144236.   Expr *pOBExpr;        /* An expression from the ORDER BY clause */

  144237.   CollSeq *pColl;       /* COLLATE function from an ORDER BY clause term */

  144238.   Index *pIndex;        /* The index associated with pLoop */

  144239.   sqlite3 *db = pWInfo->pParse->db;  /* Database connection */

  144240.   Bitmask obSat = 0;    /* Mask of ORDER BY terms satisfied so far */

  144241.   Bitmask obDone;       /* Mask of all ORDER BY terms */

  144242.   Bitmask orderDistinctMask;  /* Mask of all well-ordered loops */

  144243.   Bitmask ready;              /* Mask of inner loops */

  144244. 

  144245.   /*

  144246.   ** We say the WhereLoop is "one-row" if it generates no more than one

  144247.   ** row of output.  A WhereLoop is one-row if all of the following are true:

  144248.   **  (a) All index columns match with WHERE_COLUMN_EQ.

  144249.   **  (b) The index is unique

  144250.   ** Any WhereLoop with an WHERE_COLUMN_EQ constraint on the rowid is one-row.

  144251.   ** Every one-row WhereLoop will have the WHERE_ONEROW bit set in wsFlags.

  144252.   **

  144253.   ** We say the WhereLoop is "order-distinct" if the set of columns from

  144254.   ** that WhereLoop that are in the ORDER BY clause are different for every

  144255.   ** row of the WhereLoop.  Every one-row WhereLoop is automatically

  144256.   ** order-distinct.   A WhereLoop that has no columns in the ORDER BY clause

  144257.   ** is not order-distinct. To be order-distinct is not quite the same as being

  144258.   ** UNIQUE since a UNIQUE column or index can have multiple rows that 

  144259.   ** are NULL and NULL values are equivalent for the purpose of order-distinct.

  144260.   ** To be order-distinct, the columns must be UNIQUE and NOT NULL.

  144261.   **

  144262.   ** The rowid for a table is always UNIQUE and NOT NULL so whenever the

  144263.   ** rowid appears in the ORDER BY clause, the corresponding WhereLoop is

  144264.   ** automatically order-distinct.

  144265.   */

  144266. 

  144267.   assert( pOrderBy!=0 );

  144268.   if( nLoop && OptimizationDisabled(db, SQLITE_OrderByIdxJoin) ) return 0;

  144269. 

  144270.   nOrderBy = pOrderBy->nExpr;

  144271.   testcase( nOrderBy==BMS-1 );

  144272.   if( nOrderBy>BMS-1 ) return 0;  /* Cannot optimize overly large ORDER BYs */

  144273.   isOrderDistinct = 1;

  144274.   obDone = MASKBIT(nOrderBy)-1;

  144275.   orderDistinctMask = 0;

  144276.   ready = 0;

  144277.   eqOpMask = WO_EQ | WO_IS | WO_ISNULL;

  144278.   if( wctrlFlags & WHERE_ORDERBY_LIMIT ) eqOpMask |= WO_IN;

  144279.   for(iLoop=0; isOrderDistinct && obSat<obDone && iLoop<=nLoop; iLoop++){

  144280.     if( iLoop>0 ) ready |= pLoop->maskSelf;

  144281.     if( iLoop<nLoop ){

  144282.       pLoop = pPath->aLoop[iLoop];

  144283.       if( wctrlFlags & WHERE_ORDERBY_LIMIT ) continue;

  144284.     }else{

  144285.       pLoop = pLast;

  144286.     }

  144287.     if( pLoop->wsFlags & WHERE_VIRTUALTABLE ){

  144288.       if( pLoop->u.vtab.isOrdered ) obSat = obDone;

  144289.       break;

  144290.     }else{

  144291.       pLoop->u.btree.nIdxCol = 0;

  144292.     }

  144293.     iCur = pWInfo->pTabList->a[pLoop->iTab].iCursor;

  144294. 

  144295.     /* Mark off any ORDER BY term X that is a column in the table of

  144296.     ** the current loop for which there is term in the WHERE

  144297.     ** clause of the form X IS NULL or X=? that reference only outer

  144298.     ** loops.

  144299.     */

  144300.     for(i=0; i<nOrderBy; i++){

  144301.       if( MASKBIT(i) & obSat ) continue;

  144302.       pOBExpr = sqlite3ExprSkipCollate(pOrderBy->a[i].pExpr);

  144303.       if( pOBExpr->op!=TK_COLUMN ) continue;

  144304.       if( pOBExpr->iTable!=iCur ) continue;

  144305.       pTerm = sqlite3WhereFindTerm(&pWInfo->sWC, iCur, pOBExpr->iColumn,

  144306.                        ~ready, eqOpMask, 0);

  144307.       if( pTerm==0 ) continue;

  144308.       if( pTerm->eOperator==WO_IN ){

  144309.         /* IN terms are only valid for sorting in the ORDER BY LIMIT 

  144310.         ** optimization, and then only if they are actually used

  144311.         ** by the query plan */

  144312.         assert( wctrlFlags & WHERE_ORDERBY_LIMIT );

  144313.         for(j=0; j<pLoop->nLTerm && pTerm!=pLoop->aLTerm[j]; j++){}

  144314.         if( j>=pLoop->nLTerm ) continue;

  144315.       }

  144316.       if( (pTerm->eOperator&(WO_EQ|WO_IS))!=0 && pOBExpr->iColumn>=0 ){

  144317.         if( sqlite3ExprCollSeqMatch(pWInfo->pParse, 

  144318.                   pOrderBy->a[i].pExpr, pTerm->pExpr)==0 ){

  144319.           continue;

  144320.         }

  144321.         testcase( pTerm->pExpr->op==TK_IS );

  144322.       }

  144323.       obSat |= MASKBIT(i);

  144324.     }

  144325. 

  144326.     if( (pLoop->wsFlags & WHERE_ONEROW)==0 ){

  144327.       if( pLoop->wsFlags & WHERE_IPK ){

  144328.         pIndex = 0;

  144329.         nKeyCol = 0;

  144330.         nColumn = 1;

  144331.       }else if( (pIndex = pLoop->u.btree.pIndex)==0 || pIndex->bUnordered ){

  144332.         return 0;

  144333.       }else{

  144334.         nKeyCol = pIndex->nKeyCol;

  144335.         nColumn = pIndex->nColumn;

  144336.         assert( nColumn==nKeyCol+1 || !HasRowid(pIndex->pTable) );

  144337.         assert( pIndex->aiColumn[nColumn-1]==XN_ROWID

  144338.                           || !HasRowid(pIndex->pTable));

  144339.         isOrderDistinct = IsUniqueIndex(pIndex);

  144340.       }

  144341. 

  144342.       /* Loop through all columns of the index and deal with the ones

  144343.       ** that are not constrained by == or IN.

  144344.       */

  144345.       rev = revSet = 0;

  144346.       distinctColumns = 0;

  144347.       for(j=0; j<nColumn; j++){

  144348.         u8 bOnce = 1; /* True to run the ORDER BY search loop */

  144349. 

  144350.         assert( j>=pLoop->u.btree.nEq 

  144351.             || (pLoop->aLTerm[j]==0)==(j<pLoop->nSkip)

  144352.         );

  144353.         if( j<pLoop->u.btree.nEq && j>=pLoop->nSkip ){

  144354.           u16 eOp = pLoop->aLTerm[j]->eOperator;

  144355. 

  144356.           /* Skip over == and IS and ISNULL terms.  (Also skip IN terms when

  144357.           ** doing WHERE_ORDERBY_LIMIT processing). 

  144358.           **

  144359.           ** If the current term is a column of an ((?,?) IN (SELECT...)) 

  144360.           ** expression for which the SELECT returns more than one column,

  144361.           ** check that it is the only column used by this loop. Otherwise,

  144362.           ** if it is one of two or more, none of the columns can be

  144363.           ** considered to match an ORDER BY term.  */

  144364.           if( (eOp & eqOpMask)!=0 ){

  144365.             if( eOp & WO_ISNULL ){

  144366.               testcase( isOrderDistinct );

  144367.               isOrderDistinct = 0;

  144368.             }

  144369.             continue;  

  144370.           }else if( ALWAYS(eOp & WO_IN) ){

  144371.             /* ALWAYS() justification: eOp is an equality operator due to the

  144372.             ** j<pLoop->u.btree.nEq constraint above.  Any equality other

  144373.             ** than WO_IN is captured by the previous "if".  So this one

  144374.             ** always has to be WO_IN. */

  144375.             Expr *pX = pLoop->aLTerm[j]->pExpr;

  144376.             for(i=j+1; i<pLoop->u.btree.nEq; i++){

  144377.               if( pLoop->aLTerm[i]->pExpr==pX ){

  144378.                 assert( (pLoop->aLTerm[i]->eOperator & WO_IN) );

  144379.                 bOnce = 0;

  144380.                 break;

  144381.               }

  144382.             }

  144383.           }

  144384.         }

  144385. 

  144386.         /* Get the column number in the table (iColumn) and sort order

  144387.         ** (revIdx) for the j-th column of the index.

  144388.         */

  144389.         if( pIndex ){

  144390.           iColumn = pIndex->aiColumn[j];

  144391.           revIdx = pIndex->aSortOrder[j];

  144392.           if( iColumn==pIndex->pTable->iPKey ) iColumn = XN_ROWID;

  144393.         }else{

  144394.           iColumn = XN_ROWID;

  144395.           revIdx = 0;

  144396.         }

  144397. 

  144398.         /* An unconstrained column that might be NULL means that this

  144399.         ** WhereLoop is not well-ordered

  144400.         */

  144401.         if( isOrderDistinct

  144402.          && iColumn>=0

  144403.          && j>=pLoop->u.btree.nEq

  144404.          && pIndex->pTable->aCol[iColumn].notNull==0

  144405.         ){

  144406.           isOrderDistinct = 0;

  144407.         }

  144408. 

  144409.         /* Find the ORDER BY term that corresponds to the j-th column

  144410.         ** of the index and mark that ORDER BY term off 

  144411.         */

  144412.         isMatch = 0;

  144413.         for(i=0; bOnce && i<nOrderBy; i++){

  144414.           if( MASKBIT(i) & obSat ) continue;

  144415.           pOBExpr = sqlite3ExprSkipCollate(pOrderBy->a[i].pExpr);

  144416.           testcase( wctrlFlags & WHERE_GROUPBY );

  144417.           testcase( wctrlFlags & WHERE_DISTINCTBY );

  144418.           if( (wctrlFlags & (WHERE_GROUPBY|WHERE_DISTINCTBY))==0 ) bOnce = 0;

  144419.           if( iColumn>=XN_ROWID ){

  144420.             if( pOBExpr->op!=TK_COLUMN ) continue;

  144421.             if( pOBExpr->iTable!=iCur ) continue;

  144422.             if( pOBExpr->iColumn!=iColumn ) continue;

  144423.           }else{

  144424.             Expr *pIdxExpr = pIndex->aColExpr->a[j].pExpr;

  144425.             if( sqlite3ExprCompareSkip(pOBExpr, pIdxExpr, iCur) ){

  144426.               continue;

  144427.             }

  144428.           }

  144429.           if( iColumn!=XN_ROWID ){

  144430.             pColl = sqlite3ExprNNCollSeq(pWInfo->pParse, pOrderBy->a[i].pExpr);

  144431.             if( sqlite3StrICmp(pColl->zName, pIndex->azColl[j])!=0 ) continue;

  144432.           }

  144433.           pLoop->u.btree.nIdxCol = j+1;

  144434.           isMatch = 1;

  144435.           break;

  144436.         }

  144437.         if( isMatch && (wctrlFlags & WHERE_GROUPBY)==0 ){

  144438.           /* Make sure the sort order is compatible in an ORDER BY clause.

  144439.           ** Sort order is irrelevant for a GROUP BY clause. */

  144440.           if( revSet ){

  144441.             if( (rev ^ revIdx)!=pOrderBy->a[i].sortOrder ) isMatch = 0;

  144442.           }else{

  144443.             rev = revIdx ^ pOrderBy->a[i].sortOrder;

  144444.             if( rev ) *pRevMask |= MASKBIT(iLoop);

  144445.             revSet = 1;

  144446.           }

  144447.         }

  144448.         if( isMatch ){

  144449.           if( iColumn==XN_ROWID ){

  144450.             testcase( distinctColumns==0 );

  144451.             distinctColumns = 1;

  144452.           }

  144453.           obSat |= MASKBIT(i);

  144454.         }else{

  144455.           /* No match found */

  144456.           if( j==0 || j<nKeyCol ){

  144457.             testcase( isOrderDistinct!=0 );

  144458.             isOrderDistinct = 0;

  144459.           }

  144460.           break;

  144461.         }

  144462.       } /* end Loop over all index columns */

  144463.       if( distinctColumns ){

  144464.         testcase( isOrderDistinct==0 );

  144465.         isOrderDistinct = 1;

  144466.       }

  144467.     } /* end-if not one-row */

  144468. 

  144469.     /* Mark off any other ORDER BY terms that reference pLoop */

  144470.     if( isOrderDistinct ){

  144471.       orderDistinctMask |= pLoop->maskSelf;

  144472.       for(i=0; i<nOrderBy; i++){

  144473.         Expr *p;

  144474.         Bitmask mTerm;

  144475.         if( MASKBIT(i) & obSat ) continue;

  144476.         p = pOrderBy->a[i].pExpr;

  144477.         mTerm = sqlite3WhereExprUsage(&pWInfo->sMaskSet,p);

  144478.         if( mTerm==0 && !sqlite3ExprIsConstant(p) ) continue;

  144479.         if( (mTerm&~orderDistinctMask)==0 ){

  144480.           obSat |= MASKBIT(i);

  144481.         }

  144482.       }

  144483.     }

  144484.   } /* End the loop over all WhereLoops from outer-most down to inner-most */

  144485.   if( obSat==obDone ) return (i8)nOrderBy;

  144486.   if( !isOrderDistinct ){

  144487.     for(i=nOrderBy-1; i>0; i--){

  144488.       Bitmask m = MASKBIT(i) - 1;

  144489.       if( (obSat&m)==m ) return i;

  144490.     }

  144491.     return 0;

  144492.   }

  144493.   return -1;

  144494. }

  144495. 

  144496. 

  144497. /*

  144498. ** If the WHERE_GROUPBY flag is set in the mask passed to sqlite3WhereBegin(),

  144499. ** the planner assumes that the specified pOrderBy list is actually a GROUP

  144500. ** BY clause - and so any order that groups rows as required satisfies the

  144501. ** request.

  144502. **

  144503. ** Normally, in this case it is not possible for the caller to determine

  144504. ** whether or not the rows are really being delivered in sorted order, or

  144505. ** just in some other order that provides the required grouping. However,

  144506. ** if the WHERE_SORTBYGROUP flag is also passed to sqlite3WhereBegin(), then

  144507. ** this function may be called on the returned WhereInfo object. It returns

  144508. ** true if the rows really will be sorted in the specified order, or false

  144509. ** otherwise.

  144510. **

  144511. ** For example, assuming:

  144512. **

  144513. **   CREATE INDEX i1 ON t1(x, Y);

  144514. **

  144515. ** then

  144516. **

  144517. **   SELECT * FROM t1 GROUP BY x,y ORDER BY x,y;   -- IsSorted()==1

  144518. **   SELECT * FROM t1 GROUP BY y,x ORDER BY y,x;   -- IsSorted()==0

  144519. */

  144520. SQLITE_PRIVATE int sqlite3WhereIsSorted(WhereInfo *pWInfo){

  144521.   assert( pWInfo->wctrlFlags & WHERE_GROUPBY );

  144522.   assert( pWInfo->wctrlFlags & WHERE_SORTBYGROUP );

  144523.   return pWInfo->sorted;

  144524. }

  144525. 

  144526. #ifdef WHERETRACE_ENABLED

  144527. /* For debugging use only: */

  144528. static const char *wherePathName(WherePath *pPath, int nLoop, WhereLoop *pLast){

  144529.   static char zName[65];

  144530.   int i;

  144531.   for(i=0; i<nLoop; i++){ zName[i] = pPath->aLoop[i]->cId; }

  144532.   if( pLast ) zName[i++] = pLast->cId;

  144533.   zName[i] = 0;

  144534.   return zName;

  144535. }

  144536. #endif

  144537. 

  144538. /*

  144539. ** Return the cost of sorting nRow rows, assuming that the keys have 

  144540. ** nOrderby columns and that the first nSorted columns are already in

  144541. ** order.

  144542. */

  144543. static LogEst whereSortingCost(

  144544.   WhereInfo *pWInfo,

  144545.   LogEst nRow,

  144546.   int nOrderBy,

  144547.   int nSorted

  144548. ){

  144549.   /* TUNING: Estimated cost of a full external sort, where N is 

  144550.   ** the number of rows to sort is:

  144551.   **

  144552.   **   cost = (3.0 * N * log(N)).

  144553.   ** 

  144554.   ** Or, if the order-by clause has X terms but only the last Y 

  144555.   ** terms are out of order, then block-sorting will reduce the 

  144556.   ** sorting cost to:

  144557.   **

  144558.   **   cost = (3.0 * N * log(N)) * (Y/X)

  144559.   **

  144560.   ** The (Y/X) term is implemented using stack variable rScale

  144561.   ** below.  */

  144562.   LogEst rScale, rSortCost;

  144563.   assert( nOrderBy>0 && 66==sqlite3LogEst(100) );

  144564.   rScale = sqlite3LogEst((nOrderBy-nSorted)*100/nOrderBy) - 66;

  144565.   rSortCost = nRow + rScale + 16;

  144566. 

  144567.   /* Multiple by log(M) where M is the number of output rows.

  144568.   ** Use the LIMIT for M if it is smaller */

  144569.   if( (pWInfo->wctrlFlags & WHERE_USE_LIMIT)!=0 && pWInfo->iLimit<nRow ){

  144570.     nRow = pWInfo->iLimit;

  144571.   }

  144572.   rSortCost += estLog(nRow);

  144573.   return rSortCost;

  144574. }

  144575. 

  144576. /*

  144577. ** Given the list of WhereLoop objects at pWInfo->pLoops, this routine

  144578. ** attempts to find the lowest cost path that visits each WhereLoop

  144579. ** once.  This path is then loaded into the pWInfo->a[].pWLoop fields.

  144580. **

  144581. ** Assume that the total number of output rows that will need to be sorted

  144582. ** will be nRowEst (in the 10*log2 representation).  Or, ignore sorting

  144583. ** costs if nRowEst==0.

  144584. **

  144585. ** Return SQLITE_OK on success or SQLITE_NOMEM of a memory allocation

  144586. ** error occurs.

  144587. */

  144588. static int wherePathSolver(WhereInfo *pWInfo, LogEst nRowEst){

  144589.   int mxChoice;             /* Maximum number of simultaneous paths tracked */

  144590.   int nLoop;                /* Number of terms in the join */

  144591.   Parse *pParse;            /* Parsing context */

  144592.   sqlite3 *db;              /* The database connection */

  144593.   int iLoop;                /* Loop counter over the terms of the join */

  144594.   int ii, jj;               /* Loop counters */

  144595.   int mxI = 0;              /* Index of next entry to replace */

  144596.   int nOrderBy;             /* Number of ORDER BY clause terms */

  144597.   LogEst mxCost = 0;        /* Maximum cost of a set of paths */

  144598.   LogEst mxUnsorted = 0;    /* Maximum unsorted cost of a set of path */

  144599.   int nTo, nFrom;           /* Number of valid entries in aTo[] and aFrom[] */

  144600.   WherePath *aFrom;         /* All nFrom paths at the previous level */

  144601.   WherePath *aTo;           /* The nTo best paths at the current level */

  144602.   WherePath *pFrom;         /* An element of aFrom[] that we are working on */

  144603.   WherePath *pTo;           /* An element of aTo[] that we are working on */

  144604.   WhereLoop *pWLoop;        /* One of the WhereLoop objects */

  144605.   WhereLoop **pX;           /* Used to divy up the pSpace memory */

  144606.   LogEst *aSortCost = 0;    /* Sorting and partial sorting costs */

  144607.   char *pSpace;             /* Temporary memory used by this routine */

  144608.   int nSpace;               /* Bytes of space allocated at pSpace */

  144609. 

  144610.   pParse = pWInfo->pParse;

  144611.   db = pParse->db;

  144612.   nLoop = pWInfo->nLevel;

  144613.   /* TUNING: For simple queries, only the best path is tracked.

  144614.   ** For 2-way joins, the 5 best paths are followed.

  144615.   ** For joins of 3 or more tables, track the 10 best paths */

  144616.   mxChoice = (nLoop<=1) ? 1 : (nLoop==2 ? 5 : 10);

  144617.   assert( nLoop<=pWInfo->pTabList->nSrc );

  144618.   WHERETRACE(0x002, ("---- begin solver.  (nRowEst=%d)\n", nRowEst));

  144619. 

  144620.   /* If nRowEst is zero and there is an ORDER BY clause, ignore it. In this

  144621.   ** case the purpose of this call is to estimate the number of rows returned

  144622.   ** by the overall query. Once this estimate has been obtained, the caller

  144623.   ** will invoke this function a second time, passing the estimate as the

  144624.   ** nRowEst parameter.  */

  144625.   if( pWInfo->pOrderBy==0 || nRowEst==0 ){

  144626.     nOrderBy = 0;

  144627.   }else{

  144628.     nOrderBy = pWInfo->pOrderBy->nExpr;

  144629.   }

  144630. 

  144631.   /* Allocate and initialize space for aTo, aFrom and aSortCost[] */

  144632.   nSpace = (sizeof(WherePath)+sizeof(WhereLoop*)*nLoop)*mxChoice*2;

  144633.   nSpace += sizeof(LogEst) * nOrderBy;

  144634.   pSpace = sqlite3DbMallocRawNN(db, nSpace);

  144635.   if( pSpace==0 ) return SQLITE_NOMEM_BKPT;

  144636.   aTo = (WherePath*)pSpace;

  144637.   aFrom = aTo+mxChoice;

  144638.   memset(aFrom, 0, sizeof(aFrom[0]));

  144639.   pX = (WhereLoop**)(aFrom+mxChoice);

  144640.   for(ii=mxChoice*2, pFrom=aTo; ii>0; ii--, pFrom++, pX += nLoop){

  144641.     pFrom->aLoop = pX;

  144642.   }

  144643.   if( nOrderBy ){

  144644.     /* If there is an ORDER BY clause and it is not being ignored, set up

  144645.     ** space for the aSortCost[] array. Each element of the aSortCost array

  144646.     ** is either zero - meaning it has not yet been initialized - or the

  144647.     ** cost of sorting nRowEst rows of data where the first X terms of

  144648.     ** the ORDER BY clause are already in order, where X is the array 

  144649.     ** index.  */

  144650.     aSortCost = (LogEst*)pX;

  144651.     memset(aSortCost, 0, sizeof(LogEst) * nOrderBy);

  144652.   }

  144653.   assert( aSortCost==0 || &pSpace[nSpace]==(char*)&aSortCost[nOrderBy] );

  144654.   assert( aSortCost!=0 || &pSpace[nSpace]==(char*)pX );

  144655. 

  144656.   /* Seed the search with a single WherePath containing zero WhereLoops.

  144657.   **

  144658.   ** TUNING: Do not let the number of iterations go above 28.  If the cost

  144659.   ** of computing an automatic index is not paid back within the first 28

  144660.   ** rows, then do not use the automatic index. */

  144661.   aFrom[0].nRow = MIN(pParse->nQueryLoop, 48);  assert( 48==sqlite3LogEst(28) );

  144662.   nFrom = 1;

  144663.   assert( aFrom[0].isOrdered==0 );

  144664.   if( nOrderBy ){

  144665.     /* If nLoop is zero, then there are no FROM terms in the query. Since

  144666.     ** in this case the query may return a maximum of one row, the results

  144667.     ** are already in the requested order. Set isOrdered to nOrderBy to

  144668.     ** indicate this. Or, if nLoop is greater than zero, set isOrdered to

  144669.     ** -1, indicating that the result set may or may not be ordered, 

  144670.     ** depending on the loops added to the current plan.  */

  144671.     aFrom[0].isOrdered = nLoop>0 ? -1 : nOrderBy;

  144672.   }

  144673. 

  144674.   /* Compute successively longer WherePaths using the previous generation

  144675.   ** of WherePaths as the basis for the next.  Keep track of the mxChoice

  144676.   ** best paths at each generation */

  144677.   for(iLoop=0; iLoop<nLoop; iLoop++){

  144678.     nTo = 0;

  144679.     for(ii=0, pFrom=aFrom; ii<nFrom; ii++, pFrom++){

  144680.       for(pWLoop=pWInfo->pLoops; pWLoop; pWLoop=pWLoop->pNextLoop){

  144681.         LogEst nOut;                      /* Rows visited by (pFrom+pWLoop) */

  144682.         LogEst rCost;                     /* Cost of path (pFrom+pWLoop) */

  144683.         LogEst rUnsorted;                 /* Unsorted cost of (pFrom+pWLoop) */

  144684.         i8 isOrdered = pFrom->isOrdered;  /* isOrdered for (pFrom+pWLoop) */

  144685.         Bitmask maskNew;                  /* Mask of src visited by (..) */

  144686.         Bitmask revMask = 0;              /* Mask of rev-order loops for (..) */

  144687. 

  144688.         if( (pWLoop->prereq & ~pFrom->maskLoop)!=0 ) continue;

  144689.         if( (pWLoop->maskSelf & pFrom->maskLoop)!=0 ) continue;

  144690.         if( (pWLoop->wsFlags & WHERE_AUTO_INDEX)!=0 && pFrom->nRow<3 ){

  144691.           /* Do not use an automatic index if the this loop is expected

  144692.           ** to run less than 1.25 times.  It is tempting to also exclude

  144693.           ** automatic index usage on an outer loop, but sometimes an automatic

  144694.           ** index is useful in the outer loop of a correlated subquery. */

  144695.           assert( 10==sqlite3LogEst(2) );

  144696.           continue;

  144697.         }

  144698. 

  144699.         /* At this point, pWLoop is a candidate to be the next loop. 

  144700.         ** Compute its cost */

  144701.         rUnsorted = sqlite3LogEstAdd(pWLoop->rSetup,pWLoop->rRun + pFrom->nRow);

  144702.         rUnsorted = sqlite3LogEstAdd(rUnsorted, pFrom->rUnsorted);

  144703.         nOut = pFrom->nRow + pWLoop->nOut;

  144704.         maskNew = pFrom->maskLoop | pWLoop->maskSelf;

  144705.         if( isOrdered<0 ){

  144706.           isOrdered = wherePathSatisfiesOrderBy(pWInfo,

  144707.                        pWInfo->pOrderBy, pFrom, pWInfo->wctrlFlags,

  144708.                        iLoop, pWLoop, &revMask);

  144709.         }else{

  144710.           revMask = pFrom->revLoop;

  144711.         }

  144712.         if( isOrdered>=0 && isOrdered<nOrderBy ){

  144713.           if( aSortCost[isOrdered]==0 ){

  144714.             aSortCost[isOrdered] = whereSortingCost(

  144715.                 pWInfo, nRowEst, nOrderBy, isOrdered

  144716.             );

  144717.           }

  144718.           /* TUNING:  Add a small extra penalty (5) to sorting as an

  144719.           ** extra encouragment to the query planner to select a plan

  144720.           ** where the rows emerge in the correct order without any sorting

  144721.           ** required. */

  144722.           rCost = sqlite3LogEstAdd(rUnsorted, aSortCost[isOrdered]) + 5;

  144723. 

  144724.           WHERETRACE(0x002,

  144725.               ("---- sort cost=%-3d (%d/%d) increases cost %3d to %-3d\n",

  144726.                aSortCost[isOrdered], (nOrderBy-isOrdered), nOrderBy, 

  144727.                rUnsorted, rCost));

  144728.         }else{

  144729.           rCost = rUnsorted;

  144730.           rUnsorted -= 2;  /* TUNING:  Slight bias in favor of no-sort plans */

  144731.         }

  144732. 

  144733.         /* Check to see if pWLoop should be added to the set of

  144734.         ** mxChoice best-so-far paths.

  144735.         **

  144736.         ** First look for an existing path among best-so-far paths

  144737.         ** that covers the same set of loops and has the same isOrdered

  144738.         ** setting as the current path candidate.

  144739.         **

  144740.         ** The term "((pTo->isOrdered^isOrdered)&0x80)==0" is equivalent

  144741.         ** to (pTo->isOrdered==(-1))==(isOrdered==(-1))" for the range

  144742.         ** of legal values for isOrdered, -1..64.

  144743.         */

  144744.         for(jj=0, pTo=aTo; jj<nTo; jj++, pTo++){

  144745.           if( pTo->maskLoop==maskNew

  144746.            && ((pTo->isOrdered^isOrdered)&0x80)==0

  144747.           ){

  144748.             testcase( jj==nTo-1 );

  144749.             break;

  144750.           }

  144751.         }

  144752.         if( jj>=nTo ){

  144753.           /* None of the existing best-so-far paths match the candidate. */

  144754.           if( nTo>=mxChoice

  144755.            && (rCost>mxCost || (rCost==mxCost && rUnsorted>=mxUnsorted))

  144756.           ){

  144757.             /* The current candidate is no better than any of the mxChoice

  144758.             ** paths currently in the best-so-far buffer.  So discard

  144759.             ** this candidate as not viable. */

  144760. #ifdef WHERETRACE_ENABLED /* 0x4 */

  144761.             if( sqlite3WhereTrace&0x4 ){

  144762.               sqlite3DebugPrintf("Skip   %s cost=%-3d,%3d,%3d order=%c\n",

  144763.                   wherePathName(pFrom, iLoop, pWLoop), rCost, nOut, rUnsorted,

  144764.                   isOrdered>=0 ? isOrdered+'0' : '?');

  144765.             }

  144766. #endif

  144767.             continue;

  144768.           }

  144769.           /* If we reach this points it means that the new candidate path

  144770.           ** needs to be added to the set of best-so-far paths. */

  144771.           if( nTo<mxChoice ){

  144772.             /* Increase the size of the aTo set by one */

  144773.             jj = nTo++;

  144774.           }else{

  144775.             /* New path replaces the prior worst to keep count below mxChoice */

  144776.             jj = mxI;

  144777.           }

  144778.           pTo = &aTo[jj];

  144779. #ifdef WHERETRACE_ENABLED /* 0x4 */

  144780.           if( sqlite3WhereTrace&0x4 ){

  144781.             sqlite3DebugPrintf("New    %s cost=%-3d,%3d,%3d order=%c\n",

  144782.                 wherePathName(pFrom, iLoop, pWLoop), rCost, nOut, rUnsorted,

  144783.                 isOrdered>=0 ? isOrdered+'0' : '?');

  144784.           }

  144785. #endif

  144786.         }else{

  144787.           /* Control reaches here if best-so-far path pTo=aTo[jj] covers the

  144788.           ** same set of loops and has the same isOrdered setting as the

  144789.           ** candidate path.  Check to see if the candidate should replace

  144790.           ** pTo or if the candidate should be skipped.

  144791.           ** 

  144792.           ** The conditional is an expanded vector comparison equivalent to:

  144793.           **   (pTo->rCost,pTo->nRow,pTo->rUnsorted) <= (rCost,nOut,rUnsorted)

  144794.           */

  144795.           if( pTo->rCost<rCost 

  144796.            || (pTo->rCost==rCost

  144797.                && (pTo->nRow<nOut

  144798.                    || (pTo->nRow==nOut && pTo->rUnsorted<=rUnsorted)

  144799.                   )

  144800.               )

  144801.           ){

  144802. #ifdef WHERETRACE_ENABLED /* 0x4 */

  144803.             if( sqlite3WhereTrace&0x4 ){

  144804.               sqlite3DebugPrintf(

  144805.                   "Skip   %s cost=%-3d,%3d,%3d order=%c",

  144806.                   wherePathName(pFrom, iLoop, pWLoop), rCost, nOut, rUnsorted,

  144807.                   isOrdered>=0 ? isOrdered+'0' : '?');

  144808.               sqlite3DebugPrintf("   vs %s cost=%-3d,%3d,%3d order=%c\n",

  144809.                   wherePathName(pTo, iLoop+1, 0), pTo->rCost, pTo->nRow,

  144810.                   pTo->rUnsorted, pTo->isOrdered>=0 ? pTo->isOrdered+'0' : '?');

  144811.             }

  144812. #endif

  144813.             /* Discard the candidate path from further consideration */

  144814.             testcase( pTo->rCost==rCost );

  144815.             continue;

  144816.           }

  144817.           testcase( pTo->rCost==rCost+1 );

  144818.           /* Control reaches here if the candidate path is better than the

  144819.           ** pTo path.  Replace pTo with the candidate. */

  144820. #ifdef WHERETRACE_ENABLED /* 0x4 */

  144821.           if( sqlite3WhereTrace&0x4 ){

  144822.             sqlite3DebugPrintf(

  144823.                 "Update %s cost=%-3d,%3d,%3d order=%c",

  144824.                 wherePathName(pFrom, iLoop, pWLoop), rCost, nOut, rUnsorted,

  144825.                 isOrdered>=0 ? isOrdered+'0' : '?');

  144826.             sqlite3DebugPrintf("  was %s cost=%-3d,%3d,%3d order=%c\n",

  144827.                 wherePathName(pTo, iLoop+1, 0), pTo->rCost, pTo->nRow,

  144828.                 pTo->rUnsorted, pTo->isOrdered>=0 ? pTo->isOrdered+'0' : '?');

  144829.           }

  144830. #endif

  144831.         }

  144832.         /* pWLoop is a winner.  Add it to the set of best so far */

  144833.         pTo->maskLoop = pFrom->maskLoop | pWLoop->maskSelf;

  144834.         pTo->revLoop = revMask;

  144835.         pTo->nRow = nOut;

  144836.         pTo->rCost = rCost;

  144837.         pTo->rUnsorted = rUnsorted;

  144838.         pTo->isOrdered = isOrdered;

  144839.         memcpy(pTo->aLoop, pFrom->aLoop, sizeof(WhereLoop*)*iLoop);

  144840.         pTo->aLoop[iLoop] = pWLoop;

  144841.         if( nTo>=mxChoice ){

  144842.           mxI = 0;

  144843.           mxCost = aTo[0].rCost;

  144844.           mxUnsorted = aTo[0].nRow;

  144845.           for(jj=1, pTo=&aTo[1]; jj<mxChoice; jj++, pTo++){

  144846.             if( pTo->rCost>mxCost 

  144847.              || (pTo->rCost==mxCost && pTo->rUnsorted>mxUnsorted) 

  144848.             ){

  144849.               mxCost = pTo->rCost;

  144850.               mxUnsorted = pTo->rUnsorted;

  144851.               mxI = jj;

  144852.             }

  144853.           }

  144854.         }

  144855.       }

  144856.     }

  144857. 

  144858. #ifdef WHERETRACE_ENABLED  /* >=2 */

  144859.     if( sqlite3WhereTrace & 0x02 ){

  144860.       sqlite3DebugPrintf("---- after round %d ----\n", iLoop);

  144861.       for(ii=0, pTo=aTo; ii<nTo; ii++, pTo++){

  144862.         sqlite3DebugPrintf(" %s cost=%-3d nrow=%-3d order=%c",

  144863.            wherePathName(pTo, iLoop+1, 0), pTo->rCost, pTo->nRow,

  144864.            pTo->isOrdered>=0 ? (pTo->isOrdered+'0') : '?');

  144865.         if( pTo->isOrdered>0 ){

  144866.           sqlite3DebugPrintf(" rev=0x%llx\n", pTo->revLoop);

  144867.         }else{

  144868.           sqlite3DebugPrintf("\n");

  144869.         }

  144870.       }

  144871.     }

  144872. #endif

  144873. 

  144874.     /* Swap the roles of aFrom and aTo for the next generation */

  144875.     pFrom = aTo;

  144876.     aTo = aFrom;

  144877.     aFrom = pFrom;

  144878.     nFrom = nTo;

  144879.   }

  144880. 

  144881.   if( nFrom==0 ){

  144882.     sqlite3ErrorMsg(pParse, "no query solution");

  144883.     sqlite3DbFreeNN(db, pSpace);

  144884.     return SQLITE_ERROR;

  144885.   }

  144886.   

  144887.   /* Find the lowest cost path.  pFrom will be left pointing to that path */

  144888.   pFrom = aFrom;

  144889.   for(ii=1; ii<nFrom; ii++){

  144890.     if( pFrom->rCost>aFrom[ii].rCost ) pFrom = &aFrom[ii];

  144891.   }

  144892.   assert( pWInfo->nLevel==nLoop );

  144893.   /* Load the lowest cost path into pWInfo */

  144894.   for(iLoop=0; iLoop<nLoop; iLoop++){

  144895.     WhereLevel *pLevel = pWInfo->a + iLoop;

  144896.     pLevel->pWLoop = pWLoop = pFrom->aLoop[iLoop];

  144897.     pLevel->iFrom = pWLoop->iTab;

  144898.     pLevel->iTabCur = pWInfo->pTabList->a[pLevel->iFrom].iCursor;

  144899.   }

  144900.   if( (pWInfo->wctrlFlags & WHERE_WANT_DISTINCT)!=0

  144901.    && (pWInfo->wctrlFlags & WHERE_DISTINCTBY)==0

  144902.    && pWInfo->eDistinct==WHERE_DISTINCT_NOOP

  144903.    && nRowEst

  144904.   ){

  144905.     Bitmask notUsed;

  144906.     int rc = wherePathSatisfiesOrderBy(pWInfo, pWInfo->pResultSet, pFrom,

  144907.                  WHERE_DISTINCTBY, nLoop-1, pFrom->aLoop[nLoop-1], &notUsed);

  144908.     if( rc==pWInfo->pResultSet->nExpr ){

  144909.       pWInfo->eDistinct = WHERE_DISTINCT_ORDERED;

  144910.     }

  144911.   }

  144912.   pWInfo->bOrderedInnerLoop = 0;

  144913.   if( pWInfo->pOrderBy ){

  144914.     if( pWInfo->wctrlFlags & WHERE_DISTINCTBY ){

  144915.       if( pFrom->isOrdered==pWInfo->pOrderBy->nExpr ){

  144916.         pWInfo->eDistinct = WHERE_DISTINCT_ORDERED;

  144917.       }

  144918.     }else{

  144919.       pWInfo->nOBSat = pFrom->isOrdered;

  144920.       pWInfo->revMask = pFrom->revLoop;

  144921.       if( pWInfo->nOBSat<=0 ){

  144922.         pWInfo->nOBSat = 0;

  144923.         if( nLoop>0 ){

  144924.           u32 wsFlags = pFrom->aLoop[nLoop-1]->wsFlags;

  144925.           if( (wsFlags & WHERE_ONEROW)==0 

  144926.            && (wsFlags&(WHERE_IPK|WHERE_COLUMN_IN))!=(WHERE_IPK|WHERE_COLUMN_IN)

  144927.           ){

  144928.             Bitmask m = 0;

  144929.             int rc = wherePathSatisfiesOrderBy(pWInfo, pWInfo->pOrderBy, pFrom,

  144930.                       WHERE_ORDERBY_LIMIT, nLoop-1, pFrom->aLoop[nLoop-1], &m);

  144931.             testcase( wsFlags & WHERE_IPK );

  144932.             testcase( wsFlags & WHERE_COLUMN_IN );

  144933.             if( rc==pWInfo->pOrderBy->nExpr ){

  144934.               pWInfo->bOrderedInnerLoop = 1;

  144935.               pWInfo->revMask = m;

  144936.             }

  144937.           }

  144938.         }

  144939.       }

  144940.     }

  144941.     if( (pWInfo->wctrlFlags & WHERE_SORTBYGROUP)

  144942.         && pWInfo->nOBSat==pWInfo->pOrderBy->nExpr && nLoop>0

  144943.     ){

  144944.       Bitmask revMask = 0;

  144945.       int nOrder = wherePathSatisfiesOrderBy(pWInfo, pWInfo->pOrderBy, 

  144946.           pFrom, 0, nLoop-1, pFrom->aLoop[nLoop-1], &revMask

  144947.       );

  144948.       assert( pWInfo->sorted==0 );

  144949.       if( nOrder==pWInfo->pOrderBy->nExpr ){

  144950.         pWInfo->sorted = 1;

  144951.         pWInfo->revMask = revMask;

  144952.       }

  144953.     }

  144954.   }

  144955. 

  144956. 

  144957.   pWInfo->nRowOut = pFrom->nRow;

  144958. 

  144959.   /* Free temporary memory and return success */

  144960.   sqlite3DbFreeNN(db, pSpace);

  144961.   return SQLITE_OK;

  144962. }

  144963. 

  144964. /*

  144965. ** Most queries use only a single table (they are not joins) and have

  144966. ** simple == constraints against indexed fields.  This routine attempts

  144967. ** to plan those simple cases using much less ceremony than the

  144968. ** general-purpose query planner, and thereby yield faster sqlite3_prepare()

  144969. ** times for the common case.

  144970. **

  144971. ** Return non-zero on success, if this query can be handled by this

  144972. ** no-frills query planner.  Return zero if this query needs the 

  144973. ** general-purpose query planner.

  144974. */

  144975. static int whereShortCut(WhereLoopBuilder *pBuilder){

  144976.   WhereInfo *pWInfo;

  144977.   struct SrcList_item *pItem;

  144978.   WhereClause *pWC;

  144979.   WhereTerm *pTerm;

  144980.   WhereLoop *pLoop;

  144981.   int iCur;

  144982.   int j;

  144983.   Table *pTab;

  144984.   Index *pIdx;

  144985. 

  144986.   pWInfo = pBuilder->pWInfo;

  144987.   if( pWInfo->wctrlFlags & WHERE_OR_SUBCLAUSE ) return 0;

  144988.   assert( pWInfo->pTabList->nSrc>=1 );

  144989.   pItem = pWInfo->pTabList->a;

  144990.   pTab = pItem->pTab;

  144991.   if( IsVirtual(pTab) ) return 0;

  144992.   if( pItem->fg.isIndexedBy ) return 0;

  144993.   iCur = pItem->iCursor;

  144994.   pWC = &pWInfo->sWC;

  144995.   pLoop = pBuilder->pNew;

  144996.   pLoop->wsFlags = 0;

  144997.   pLoop->nSkip = 0;

  144998.   pTerm = sqlite3WhereFindTerm(pWC, iCur, -1, 0, WO_EQ|WO_IS, 0);

  144999.   if( pTerm ){

  145000.     testcase( pTerm->eOperator & WO_IS );

  145001.     pLoop->wsFlags = WHERE_COLUMN_EQ|WHERE_IPK|WHERE_ONEROW;

  145002.     pLoop->aLTerm[0] = pTerm;

  145003.     pLoop->nLTerm = 1;

  145004.     pLoop->u.btree.nEq = 1;

  145005.     /* TUNING: Cost of a rowid lookup is 10 */

  145006.     pLoop->rRun = 33;  /* 33==sqlite3LogEst(10) */

  145007.   }else{

  145008.     for(pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext){

  145009.       int opMask;

  145010.       assert( pLoop->aLTermSpace==pLoop->aLTerm );

  145011.       if( !IsUniqueIndex(pIdx)

  145012.        || pIdx->pPartIdxWhere!=0 

  145013.        || pIdx->nKeyCol>ArraySize(pLoop->aLTermSpace) 

  145014.       ) continue;

  145015.       opMask = pIdx->uniqNotNull ? (WO_EQ|WO_IS) : WO_EQ;

  145016.       for(j=0; j<pIdx->nKeyCol; j++){

  145017.         pTerm = sqlite3WhereFindTerm(pWC, iCur, j, 0, opMask, pIdx);

  145018.         if( pTerm==0 ) break;

  145019.         testcase( pTerm->eOperator & WO_IS );

  145020.         pLoop->aLTerm[j] = pTerm;

  145021.       }

  145022.       if( j!=pIdx->nKeyCol ) continue;

  145023.       pLoop->wsFlags = WHERE_COLUMN_EQ|WHERE_ONEROW|WHERE_INDEXED;

  145024.       if( pIdx->isCovering || (pItem->colUsed & pIdx->colNotIdxed)==0 ){

  145025.         pLoop->wsFlags |= WHERE_IDX_ONLY;

  145026.       }

  145027.       pLoop->nLTerm = j;

  145028.       pLoop->u.btree.nEq = j;

  145029.       pLoop->u.btree.pIndex = pIdx;

  145030.       /* TUNING: Cost of a unique index lookup is 15 */

  145031.       pLoop->rRun = 39;  /* 39==sqlite3LogEst(15) */

  145032.       break;

  145033.     }

  145034.   }

  145035.   if( pLoop->wsFlags ){

  145036.     pLoop->nOut = (LogEst)1;

  145037.     pWInfo->a[0].pWLoop = pLoop;

  145038.     assert( pWInfo->sMaskSet.n==1 && iCur==pWInfo->sMaskSet.ix[0] );

  145039.     pLoop->maskSelf = 1; /* sqlite3WhereGetMask(&pWInfo->sMaskSet, iCur); */

  145040.     pWInfo->a[0].iTabCur = iCur;

  145041.     pWInfo->nRowOut = 1;

  145042.     if( pWInfo->pOrderBy ) pWInfo->nOBSat =  pWInfo->pOrderBy->nExpr;

  145043.     if( pWInfo->wctrlFlags & WHERE_WANT_DISTINCT ){

  145044.       pWInfo->eDistinct = WHERE_DISTINCT_UNIQUE;

  145045.     }

  145046. #ifdef SQLITE_DEBUG

  145047.     pLoop->cId = '0';

  145048. #endif

  145049.     return 1;

  145050.   }

  145051.   return 0;

  145052. }

  145053. 

  145054. /*

  145055. ** Helper function for exprIsDeterministic().

  145056. */

  145057. static int exprNodeIsDeterministic(Walker *pWalker, Expr *pExpr){

  145058.   if( pExpr->op==TK_FUNCTION && ExprHasProperty(pExpr, EP_ConstFunc)==0 ){

  145059.     pWalker->eCode = 0;

  145060.     return WRC_Abort;

  145061.   }

  145062.   return WRC_Continue;

  145063. }

  145064. 

  145065. /*

  145066. ** Return true if the expression contains no non-deterministic SQL 

  145067. ** functions. Do not consider non-deterministic SQL functions that are 

  145068. ** part of sub-select statements.

  145069. */

  145070. static int exprIsDeterministic(Expr *p){

  145071.   Walker w;

  145072.   memset(&w, 0, sizeof(w));

  145073.   w.eCode = 1;

  145074.   w.xExprCallback = exprNodeIsDeterministic;

  145075.   w.xSelectCallback = sqlite3SelectWalkFail;

  145076.   sqlite3WalkExpr(&w, p);

  145077.   return w.eCode;

  145078. }

  145079. 

  145080. /*

  145081. ** Generate the beginning of the loop used for WHERE clause processing.

  145082. ** The return value is a pointer to an opaque structure that contains

  145083. ** information needed to terminate the loop.  Later, the calling routine

  145084. ** should invoke sqlite3WhereEnd() with the return value of this function

  145085. ** in order to complete the WHERE clause processing.

  145086. **

  145087. ** If an error occurs, this routine returns NULL.

  145088. **

  145089. ** The basic idea is to do a nested loop, one loop for each table in

  145090. ** the FROM clause of a select.  (INSERT and UPDATE statements are the

  145091. ** same as a SELECT with only a single table in the FROM clause.)  For

  145092. ** example, if the SQL is this:

  145093. **

  145094. **       SELECT * FROM t1, t2, t3 WHERE ...;

  145095. **

  145096. ** Then the code generated is conceptually like the following:

  145097. **

  145098. **      foreach row1 in t1 do       \    Code generated

  145099. **        foreach row2 in t2 do      |-- by sqlite3WhereBegin()

  145100. **          foreach row3 in t3 do   /

  145101. **            ...

  145102. **          end                     \    Code generated

  145103. **        end                        |-- by sqlite3WhereEnd()

  145104. **      end                         /

  145105. **

  145106. ** Note that the loops might not be nested in the order in which they

  145107. ** appear in the FROM clause if a different order is better able to make

  145108. ** use of indices.  Note also that when the IN operator appears in

  145109. ** the WHERE clause, it might result in additional nested loops for

  145110. ** scanning through all values on the right-hand side of the IN.

  145111. **

  145112. ** There are Btree cursors associated with each table.  t1 uses cursor

  145113. ** number pTabList->a[0].iCursor.  t2 uses the cursor pTabList->a[1].iCursor.

  145114. ** And so forth.  This routine generates code to open those VDBE cursors

  145115. ** and sqlite3WhereEnd() generates the code to close them.

  145116. **

  145117. ** The code that sqlite3WhereBegin() generates leaves the cursors named

  145118. ** in pTabList pointing at their appropriate entries.  The [...] code

  145119. ** can use OP_Column and OP_Rowid opcodes on these cursors to extract

  145120. ** data from the various tables of the loop.

  145121. **

  145122. ** If the WHERE clause is empty, the foreach loops must each scan their

  145123. ** entire tables.  Thus a three-way join is an O(N^3) operation.  But if

  145124. ** the tables have indices and there are terms in the WHERE clause that

  145125. ** refer to those indices, a complete table scan can be avoided and the

  145126. ** code will run much faster.  Most of the work of this routine is checking

  145127. ** to see if there are indices that can be used to speed up the loop.

  145128. **

  145129. ** Terms of the WHERE clause are also used to limit which rows actually

  145130. ** make it to the "..." in the middle of the loop.  After each "foreach",

  145131. ** terms of the WHERE clause that use only terms in that loop and outer

  145132. ** loops are evaluated and if false a jump is made around all subsequent

  145133. ** inner loops (or around the "..." if the test occurs within the inner-

  145134. ** most loop)

  145135. **

  145136. ** OUTER JOINS

  145137. **

  145138. ** An outer join of tables t1 and t2 is conceptally coded as follows:

  145139. **

  145140. **    foreach row1 in t1 do

  145141. **      flag = 0

  145142. **      foreach row2 in t2 do

  145143. **        start:

  145144. **          ...

  145145. **          flag = 1

  145146. **      end

  145147. **      if flag==0 then

  145148. **        move the row2 cursor to a null row

  145149. **        goto start

  145150. **      fi

  145151. **    end

  145152. **

  145153. ** ORDER BY CLAUSE PROCESSING

  145154. **

  145155. ** pOrderBy is a pointer to the ORDER BY clause (or the GROUP BY clause

  145156. ** if the WHERE_GROUPBY flag is set in wctrlFlags) of a SELECT statement

  145157. ** if there is one.  If there is no ORDER BY clause or if this routine

  145158. ** is called from an UPDATE or DELETE statement, then pOrderBy is NULL.

  145159. **

  145160. ** The iIdxCur parameter is the cursor number of an index.  If 

  145161. ** WHERE_OR_SUBCLAUSE is set, iIdxCur is the cursor number of an index

  145162. ** to use for OR clause processing.  The WHERE clause should use this

  145163. ** specific cursor.  If WHERE_ONEPASS_DESIRED is set, then iIdxCur is

  145164. ** the first cursor in an array of cursors for all indices.  iIdxCur should

  145165. ** be used to compute the appropriate cursor depending on which index is

  145166. ** used.

  145167. */

  145168. SQLITE_PRIVATE WhereInfo *sqlite3WhereBegin(

  145169.   Parse *pParse,          /* The parser context */

  145170.   SrcList *pTabList,      /* FROM clause: A list of all tables to be scanned */

  145171.   Expr *pWhere,           /* The WHERE clause */

  145172.   ExprList *pOrderBy,     /* An ORDER BY (or GROUP BY) clause, or NULL */

  145173.   ExprList *pResultSet,   /* Query result set.  Req'd for DISTINCT */

  145174.   u16 wctrlFlags,         /* The WHERE_* flags defined in sqliteInt.h */

  145175.   int iAuxArg             /* If WHERE_OR_SUBCLAUSE is set, index cursor number

  145176.                           ** If WHERE_USE_LIMIT, then the limit amount */

  145177. ){

  145178.   int nByteWInfo;            /* Num. bytes allocated for WhereInfo struct */

  145179.   int nTabList;              /* Number of elements in pTabList */

  145180.   WhereInfo *pWInfo;         /* Will become the return value of this function */

  145181.   Vdbe *v = pParse->pVdbe;   /* The virtual database engine */

  145182.   Bitmask notReady;          /* Cursors that are not yet positioned */

  145183.   WhereLoopBuilder sWLB;     /* The WhereLoop builder */

  145184.   WhereMaskSet *pMaskSet;    /* The expression mask set */

  145185.   WhereLevel *pLevel;        /* A single level in pWInfo->a[] */

  145186.   WhereLoop *pLoop;          /* Pointer to a single WhereLoop object */

  145187.   int ii;                    /* Loop counter */

  145188.   sqlite3 *db;               /* Database connection */

  145189.   int rc;                    /* Return code */

  145190.   u8 bFordelete = 0;         /* OPFLAG_FORDELETE or zero, as appropriate */

  145191. 

  145192.   assert( (wctrlFlags & WHERE_ONEPASS_MULTIROW)==0 || (

  145193.         (wctrlFlags & WHERE_ONEPASS_DESIRED)!=0 

  145194.      && (wctrlFlags & WHERE_OR_SUBCLAUSE)==0 

  145195.   ));

  145196. 

  145197.   /* Only one of WHERE_OR_SUBCLAUSE or WHERE_USE_LIMIT */

  145198.   assert( (wctrlFlags & WHERE_OR_SUBCLAUSE)==0

  145199.             || (wctrlFlags & WHERE_USE_LIMIT)==0 );

  145200. 

  145201.   /* Variable initialization */

  145202.   db = pParse->db;

  145203.   memset(&sWLB, 0, sizeof(sWLB));

  145204. 

  145205.   /* An ORDER/GROUP BY clause of more than 63 terms cannot be optimized */

  145206.   testcase( pOrderBy && pOrderBy->nExpr==BMS-1 );

  145207.   if( pOrderBy && pOrderBy->nExpr>=BMS ) pOrderBy = 0;

  145208.   sWLB.pOrderBy = pOrderBy;

  145209. 

  145210.   /* Disable the DISTINCT optimization if SQLITE_DistinctOpt is set via

  145211.   ** sqlite3_test_ctrl(SQLITE_TESTCTRL_OPTIMIZATIONS,...) */

  145212.   if( OptimizationDisabled(db, SQLITE_DistinctOpt) ){

  145213.     wctrlFlags &= ~WHERE_WANT_DISTINCT;

  145214.   }

  145215. 

  145216.   /* The number of tables in the FROM clause is limited by the number of

  145217.   ** bits in a Bitmask 

  145218.   */

  145219.   testcase( pTabList->nSrc==BMS );

  145220.   if( pTabList->nSrc>BMS ){

  145221.     sqlite3ErrorMsg(pParse, "at most %d tables in a join", BMS);

  145222.     return 0;

  145223.   }

  145224. 

  145225.   /* This function normally generates a nested loop for all tables in 

  145226.   ** pTabList.  But if the WHERE_OR_SUBCLAUSE flag is set, then we should

  145227.   ** only generate code for the first table in pTabList and assume that

  145228.   ** any cursors associated with subsequent tables are uninitialized.

  145229.   */

  145230.   nTabList = (wctrlFlags & WHERE_OR_SUBCLAUSE) ? 1 : pTabList->nSrc;

  145231. 

  145232.   /* Allocate and initialize the WhereInfo structure that will become the

  145233.   ** return value. A single allocation is used to store the WhereInfo

  145234.   ** struct, the contents of WhereInfo.a[], the WhereClause structure

  145235.   ** and the WhereMaskSet structure. Since WhereClause contains an 8-byte

  145236.   ** field (type Bitmask) it must be aligned on an 8-byte boundary on

  145237.   ** some architectures. Hence the ROUND8() below.

  145238.   */

  145239.   nByteWInfo = ROUND8(sizeof(WhereInfo)+(nTabList-1)*sizeof(WhereLevel));

  145240.   pWInfo = sqlite3DbMallocRawNN(db, nByteWInfo + sizeof(WhereLoop));

  145241.   if( db->mallocFailed ){

  145242.     sqlite3DbFree(db, pWInfo);

  145243.     pWInfo = 0;

  145244.     goto whereBeginError;

  145245.   }

  145246.   pWInfo->pParse = pParse;

  145247.   pWInfo->pTabList = pTabList;

  145248.   pWInfo->pOrderBy = pOrderBy;

  145249.   pWInfo->pWhere = pWhere;

  145250.   pWInfo->pResultSet = pResultSet;

  145251.   pWInfo->aiCurOnePass[0] = pWInfo->aiCurOnePass[1] = -1;

  145252.   pWInfo->nLevel = nTabList;

  145253.   pWInfo->iBreak = pWInfo->iContinue = sqlite3VdbeMakeLabel(pParse);

  145254.   pWInfo->wctrlFlags = wctrlFlags;

  145255.   pWInfo->iLimit = iAuxArg;

  145256.   pWInfo->savedNQueryLoop = pParse->nQueryLoop;

  145257.   memset(&pWInfo->nOBSat, 0, 

  145258.          offsetof(WhereInfo,sWC) - offsetof(WhereInfo,nOBSat));

  145259.   memset(&pWInfo->a[0], 0, sizeof(WhereLoop)+nTabList*sizeof(WhereLevel));

  145260.   assert( pWInfo->eOnePass==ONEPASS_OFF );  /* ONEPASS defaults to OFF */

  145261.   pMaskSet = &pWInfo->sMaskSet;

  145262.   sWLB.pWInfo = pWInfo;

  145263.   sWLB.pWC = &pWInfo->sWC;

  145264.   sWLB.pNew = (WhereLoop*)(((char*)pWInfo)+nByteWInfo);

  145265.   assert( EIGHT_BYTE_ALIGNMENT(sWLB.pNew) );

  145266.   whereLoopInit(sWLB.pNew);

  145267. #ifdef SQLITE_DEBUG

  145268.   sWLB.pNew->cId = '*';

  145269. #endif

  145270. 

  145271.   /* Split the WHERE clause into separate subexpressions where each

  145272.   ** subexpression is separated by an AND operator.

  145273.   */

  145274.   initMaskSet(pMaskSet);

  145275.   sqlite3WhereClauseInit(&pWInfo->sWC, pWInfo);

  145276.   sqlite3WhereSplit(&pWInfo->sWC, pWhere, TK_AND);

  145277.     

  145278.   /* Special case: No FROM clause

  145279.   */

  145280.   if( nTabList==0 ){

  145281.     if( pOrderBy ) pWInfo->nOBSat = pOrderBy->nExpr;

  145282.     if( wctrlFlags & WHERE_WANT_DISTINCT ){

  145283.       pWInfo->eDistinct = WHERE_DISTINCT_UNIQUE;

  145284.     }

  145285.     ExplainQueryPlan((pParse, 0, "SCAN CONSTANT ROW"));

  145286.   }else{

  145287.     /* Assign a bit from the bitmask to every term in the FROM clause.

  145288.     **

  145289.     ** The N-th term of the FROM clause is assigned a bitmask of 1<<N.

  145290.     **

  145291.     ** The rule of the previous sentence ensures thta if X is the bitmask for

  145292.     ** a table T, then X-1 is the bitmask for all other tables to the left of T.

  145293.     ** Knowing the bitmask for all tables to the left of a left join is

  145294.     ** important.  Ticket #3015.

  145295.     **

  145296.     ** Note that bitmasks are created for all pTabList->nSrc tables in

  145297.     ** pTabList, not just the first nTabList tables.  nTabList is normally

  145298.     ** equal to pTabList->nSrc but might be shortened to 1 if the

  145299.     ** WHERE_OR_SUBCLAUSE flag is set.

  145300.     */

  145301.     ii = 0;

  145302.     do{

  145303.       createMask(pMaskSet, pTabList->a[ii].iCursor);

  145304.       sqlite3WhereTabFuncArgs(pParse, &pTabList->a[ii], &pWInfo->sWC);

  145305.     }while( (++ii)<pTabList->nSrc );

  145306.   #ifdef SQLITE_DEBUG

  145307.     {

  145308.       Bitmask mx = 0;

  145309.       for(ii=0; ii<pTabList->nSrc; ii++){

  145310.         Bitmask m = sqlite3WhereGetMask(pMaskSet, pTabList->a[ii].iCursor);

  145311.         assert( m>=mx );

  145312.         mx = m;

  145313.       }

  145314.     }

  145315.   #endif

  145316.   }

  145317.   

  145318.   /* Analyze all of the subexpressions. */

  145319.   sqlite3WhereExprAnalyze(pTabList, &pWInfo->sWC);

  145320.   if( db->mallocFailed ) goto whereBeginError;

  145321. 

  145322.   /* Special case: WHERE terms that do not refer to any tables in the join

  145323.   ** (constant expressions). Evaluate each such term, and jump over all the

  145324.   ** generated code if the result is not true.  

  145325.   **

  145326.   ** Do not do this if the expression contains non-deterministic functions

  145327.   ** that are not within a sub-select. This is not strictly required, but

  145328.   ** preserves SQLite's legacy behaviour in the following two cases:

  145329.   **

  145330.   **   FROM ... WHERE random()>0;           -- eval random() once per row

  145331.   **   FROM ... WHERE (SELECT random())>0;  -- eval random() once overall

  145332.   */

  145333.   for(ii=0; ii<sWLB.pWC->nTerm; ii++){

  145334.     WhereTerm *pT = &sWLB.pWC->a[ii];

  145335.     if( pT->wtFlags & TERM_VIRTUAL ) continue;

  145336.     if( pT->prereqAll==0 && (nTabList==0 || exprIsDeterministic(pT->pExpr)) ){

  145337.       sqlite3ExprIfFalse(pParse, pT->pExpr, pWInfo->iBreak, SQLITE_JUMPIFNULL);

  145338.       pT->wtFlags |= TERM_CODED;

  145339.     }

  145340.   }

  145341. 

  145342.   if( wctrlFlags & WHERE_WANT_DISTINCT ){

  145343.     if( isDistinctRedundant(pParse, pTabList, &pWInfo->sWC, pResultSet) ){

  145344.       /* The DISTINCT marking is pointless.  Ignore it. */

  145345.       pWInfo->eDistinct = WHERE_DISTINCT_UNIQUE;

  145346.     }else if( pOrderBy==0 ){

  145347.       /* Try to ORDER BY the result set to make distinct processing easier */

  145348.       pWInfo->wctrlFlags |= WHERE_DISTINCTBY;

  145349.       pWInfo->pOrderBy = pResultSet;

  145350.     }

  145351.   }

  145352. 

  145353.   /* Construct the WhereLoop objects */

  145354. #if defined(WHERETRACE_ENABLED)

  145355.   if( sqlite3WhereTrace & 0xffff ){

  145356.     sqlite3DebugPrintf("*** Optimizer Start *** (wctrlFlags: 0x%x",wctrlFlags);

  145357.     if( wctrlFlags & WHERE_USE_LIMIT ){

  145358.       sqlite3DebugPrintf(", limit: %d", iAuxArg);

  145359.     }

  145360.     sqlite3DebugPrintf(")\n");

  145361.   }

  145362.   if( sqlite3WhereTrace & 0x100 ){ /* Display all terms of the WHERE clause */

  145363.     sqlite3WhereClausePrint(sWLB.pWC);

  145364.   }

  145365. #endif

  145366. 

  145367.   if( nTabList!=1 || whereShortCut(&sWLB)==0 ){

  145368.     rc = whereLoopAddAll(&sWLB);

  145369.     if( rc ) goto whereBeginError;

  145370.   

  145371. #ifdef WHERETRACE_ENABLED

  145372.     if( sqlite3WhereTrace ){    /* Display all of the WhereLoop objects */

  145373.       WhereLoop *p;

  145374.       int i;

  145375.       static const char zLabel[] = "0123456789abcdefghijklmnopqrstuvwyxz"

  145376.                                              "ABCDEFGHIJKLMNOPQRSTUVWYXZ";

  145377.       for(p=pWInfo->pLoops, i=0; p; p=p->pNextLoop, i++){

  145378.         p->cId = zLabel[i%(sizeof(zLabel)-1)];

  145379.         whereLoopPrint(p, sWLB.pWC);

  145380.       }

  145381.     }

  145382. #endif

  145383.   

  145384.     wherePathSolver(pWInfo, 0);

  145385.     if( db->mallocFailed ) goto whereBeginError;

  145386.     if( pWInfo->pOrderBy ){

  145387.        wherePathSolver(pWInfo, pWInfo->nRowOut+1);

  145388.        if( db->mallocFailed ) goto whereBeginError;

  145389.     }

  145390.   }

  145391.   if( pWInfo->pOrderBy==0 && (db->flags & SQLITE_ReverseOrder)!=0 ){

  145392.      pWInfo->revMask = ALLBITS;

  145393.   }

  145394.   if( pParse->nErr || NEVER(db->mallocFailed) ){

  145395.     goto whereBeginError;

  145396.   }

  145397. #ifdef WHERETRACE_ENABLED

  145398.   if( sqlite3WhereTrace ){

  145399.     sqlite3DebugPrintf("---- Solution nRow=%d", pWInfo->nRowOut);

  145400.     if( pWInfo->nOBSat>0 ){

  145401.       sqlite3DebugPrintf(" ORDERBY=%d,0x%llx", pWInfo->nOBSat, pWInfo->revMask);

  145402.     }

  145403.     switch( pWInfo->eDistinct ){

  145404.       case WHERE_DISTINCT_UNIQUE: {

  145405.         sqlite3DebugPrintf("  DISTINCT=unique");

  145406.         break;

  145407.       }

  145408.       case WHERE_DISTINCT_ORDERED: {

  145409.         sqlite3DebugPrintf("  DISTINCT=ordered");

  145410.         break;

  145411.       }

  145412.       case WHERE_DISTINCT_UNORDERED: {

  145413.         sqlite3DebugPrintf("  DISTINCT=unordered");

  145414.         break;

  145415.       }

  145416.     }

  145417.     sqlite3DebugPrintf("\n");

  145418.     for(ii=0; ii<pWInfo->nLevel; ii++){

  145419.       whereLoopPrint(pWInfo->a[ii].pWLoop, sWLB.pWC);

  145420.     }

  145421.   }

  145422. #endif

  145423. 

  145424.   /* Attempt to omit tables from the join that do not affect the result.

  145425.   ** For a table to not affect the result, the following must be true:

  145426.   **

  145427.   **   1) The query must not be an aggregate.

  145428.   **   2) The table must be the RHS of a LEFT JOIN.

  145429.   **   3) Either the query must be DISTINCT, or else the ON or USING clause

  145430.   **      must contain a constraint that limits the scan of the table to 

  145431.   **      at most a single row.

  145432.   **   4) The table must not be referenced by any part of the query apart

  145433.   **      from its own USING or ON clause.

  145434.   **

  145435.   ** For example, given:

  145436.   **

  145437.   **     CREATE TABLE t1(ipk INTEGER PRIMARY KEY, v1);

  145438.   **     CREATE TABLE t2(ipk INTEGER PRIMARY KEY, v2);

  145439.   **     CREATE TABLE t3(ipk INTEGER PRIMARY KEY, v3);

  145440.   **

  145441.   ** then table t2 can be omitted from the following:

  145442.   **

  145443.   **     SELECT v1, v3 FROM t1 

  145444.   **       LEFT JOIN t2 USING (t1.ipk=t2.ipk)

  145445.   **       LEFT JOIN t3 USING (t1.ipk=t3.ipk)

  145446.   **

  145447.   ** or from:

  145448.   **

  145449.   **     SELECT DISTINCT v1, v3 FROM t1 

  145450.   **       LEFT JOIN t2

  145451.   **       LEFT JOIN t3 USING (t1.ipk=t3.ipk)

  145452.   */

  145453.   notReady = ~(Bitmask)0;

  145454.   if( pWInfo->nLevel>=2

  145455.    && pResultSet!=0               /* guarantees condition (1) above */

  145456.    && OptimizationEnabled(db, SQLITE_OmitNoopJoin)

  145457.   ){

  145458.     int i;

  145459.     Bitmask tabUsed = sqlite3WhereExprListUsage(pMaskSet, pResultSet);

  145460.     if( sWLB.pOrderBy ){

  145461.       tabUsed |= sqlite3WhereExprListUsage(pMaskSet, sWLB.pOrderBy);

  145462.     }

  145463.     for(i=pWInfo->nLevel-1; i>=1; i--){

  145464.       WhereTerm *pTerm, *pEnd;

  145465.       struct SrcList_item *pItem;

  145466.       pLoop = pWInfo->a[i].pWLoop;

  145467.       pItem = &pWInfo->pTabList->a[pLoop->iTab];

  145468.       if( (pItem->fg.jointype & JT_LEFT)==0 ) continue;

  145469.       if( (wctrlFlags & WHERE_WANT_DISTINCT)==0

  145470.        && (pLoop->wsFlags & WHERE_ONEROW)==0

  145471.       ){

  145472.         continue;

  145473.       }

  145474.       if( (tabUsed & pLoop->maskSelf)!=0 ) continue;

  145475.       pEnd = sWLB.pWC->a + sWLB.pWC->nTerm;

  145476.       for(pTerm=sWLB.pWC->a; pTerm<pEnd; pTerm++){

  145477.         if( (pTerm->prereqAll & pLoop->maskSelf)!=0 ){

  145478.           if( !ExprHasProperty(pTerm->pExpr, EP_FromJoin)

  145479.            || pTerm->pExpr->iRightJoinTable!=pItem->iCursor

  145480.           ){

  145481.             break;

  145482.           }

  145483.         }

  145484.       }

  145485.       if( pTerm<pEnd ) continue;

  145486.       WHERETRACE(0xffff, ("-> drop loop %c not used\n", pLoop->cId));

  145487.       notReady &= ~pLoop->maskSelf;

  145488.       for(pTerm=sWLB.pWC->a; pTerm<pEnd; pTerm++){

  145489.         if( (pTerm->prereqAll & pLoop->maskSelf)!=0 ){

  145490.           pTerm->wtFlags |= TERM_CODED;

  145491.         }

  145492.       }

  145493.       if( i!=pWInfo->nLevel-1 ){

  145494.         int nByte = (pWInfo->nLevel-1-i) * sizeof(WhereLevel);

  145495.         memmove(&pWInfo->a[i], &pWInfo->a[i+1], nByte);

  145496.       }

  145497.       pWInfo->nLevel--;

  145498.       nTabList--;

  145499.     }

  145500.   }

  145501.   WHERETRACE(0xffff,("*** Optimizer Finished ***\n"));

  145502.   pWInfo->pParse->nQueryLoop += pWInfo->nRowOut;

  145503. 

  145504.   /* If the caller is an UPDATE or DELETE statement that is requesting

  145505.   ** to use a one-pass algorithm, determine if this is appropriate.

  145506.   **

  145507.   ** A one-pass approach can be used if the caller has requested one

  145508.   ** and either (a) the scan visits at most one row or (b) each

  145509.   ** of the following are true:

  145510.   **

  145511.   **   * the caller has indicated that a one-pass approach can be used

  145512.   **     with multiple rows (by setting WHERE_ONEPASS_MULTIROW), and

  145513.   **   * the table is not a virtual table, and

  145514.   **   * either the scan does not use the OR optimization or the caller

  145515.   **     is a DELETE operation (WHERE_DUPLICATES_OK is only specified

  145516.   **     for DELETE).

  145517.   **

  145518.   ** The last qualification is because an UPDATE statement uses

  145519.   ** WhereInfo.aiCurOnePass[1] to determine whether or not it really can

  145520.   ** use a one-pass approach, and this is not set accurately for scans

  145521.   ** that use the OR optimization.

  145522.   */

  145523.   assert( (wctrlFlags & WHERE_ONEPASS_DESIRED)==0 || pWInfo->nLevel==1 );

  145524.   if( (wctrlFlags & WHERE_ONEPASS_DESIRED)!=0 ){

  145525.     int wsFlags = pWInfo->a[0].pWLoop->wsFlags;

  145526.     int bOnerow = (wsFlags & WHERE_ONEROW)!=0;

  145527.     assert( !(wsFlags & WHERE_VIRTUALTABLE) || IsVirtual(pTabList->a[0].pTab) );

  145528.     if( bOnerow || (

  145529.         0!=(wctrlFlags & WHERE_ONEPASS_MULTIROW)

  145530.      && !IsVirtual(pTabList->a[0].pTab)

  145531.      && (0==(wsFlags & WHERE_MULTI_OR) || (wctrlFlags & WHERE_DUPLICATES_OK))

  145532.     )){

  145533.       pWInfo->eOnePass = bOnerow ? ONEPASS_SINGLE : ONEPASS_MULTI;

  145534.       if( HasRowid(pTabList->a[0].pTab) && (wsFlags & WHERE_IDX_ONLY) ){

  145535.         if( wctrlFlags & WHERE_ONEPASS_MULTIROW ){

  145536.           bFordelete = OPFLAG_FORDELETE;

  145537.         }

  145538.         pWInfo->a[0].pWLoop->wsFlags = (wsFlags & ~WHERE_IDX_ONLY);

  145539.       }

  145540.     }

  145541.   }

  145542. 

  145543.   /* Open all tables in the pTabList and any indices selected for

  145544.   ** searching those tables.

  145545.   */

  145546.   for(ii=0, pLevel=pWInfo->a; ii<nTabList; ii++, pLevel++){

  145547.     Table *pTab;     /* Table to open */

  145548.     int iDb;         /* Index of database containing table/index */

  145549.     struct SrcList_item *pTabItem;

  145550. 

  145551.     pTabItem = &pTabList->a[pLevel->iFrom];

  145552.     pTab = pTabItem->pTab;

  145553.     iDb = sqlite3SchemaToIndex(db, pTab->pSchema);

  145554.     pLoop = pLevel->pWLoop;

  145555.     if( (pTab->tabFlags & TF_Ephemeral)!=0 || pTab->pSelect ){

  145556.       /* Do nothing */

  145557.     }else

  145558. #ifndef SQLITE_OMIT_VIRTUALTABLE

  145559.     if( (pLoop->wsFlags & WHERE_VIRTUALTABLE)!=0 ){

  145560.       const char *pVTab = (const char *)sqlite3GetVTable(db, pTab);

  145561.       int iCur = pTabItem->iCursor;

  145562.       sqlite3VdbeAddOp4(v, OP_VOpen, iCur, 0, 0, pVTab, P4_VTAB);

  145563.     }else if( IsVirtual(pTab) ){

  145564.       /* noop */

  145565.     }else

  145566. #endif

  145567.     if( (pLoop->wsFlags & WHERE_IDX_ONLY)==0

  145568.          && (wctrlFlags & WHERE_OR_SUBCLAUSE)==0 ){

  145569.       int op = OP_OpenRead;

  145570.       if( pWInfo->eOnePass!=ONEPASS_OFF ){

  145571.         op = OP_OpenWrite;

  145572.         pWInfo->aiCurOnePass[0] = pTabItem->iCursor;

  145573.       };

  145574.       sqlite3OpenTable(pParse, pTabItem->iCursor, iDb, pTab, op);

  145575.       assert( pTabItem->iCursor==pLevel->iTabCur );

  145576.       testcase( pWInfo->eOnePass==ONEPASS_OFF && pTab->nCol==BMS-1 );

  145577.       testcase( pWInfo->eOnePass==ONEPASS_OFF && pTab->nCol==BMS );

  145578.       if( pWInfo->eOnePass==ONEPASS_OFF && pTab->nCol<BMS && HasRowid(pTab) ){

  145579.         Bitmask b = pTabItem->colUsed;

  145580.         int n = 0;

  145581.         for(; b; b=b>>1, n++){}

  145582.         sqlite3VdbeChangeP4(v, -1, SQLITE_INT_TO_PTR(n), P4_INT32);

  145583.         assert( n<=pTab->nCol );

  145584.       }

  145585. #ifdef SQLITE_ENABLE_CURSOR_HINTS

  145586.       if( pLoop->u.btree.pIndex!=0 ){

  145587.         sqlite3VdbeChangeP5(v, OPFLAG_SEEKEQ|bFordelete);

  145588.       }else

  145589. #endif

  145590.       {

  145591.         sqlite3VdbeChangeP5(v, bFordelete);

  145592.       }

  145593. #ifdef SQLITE_ENABLE_COLUMN_USED_MASK

  145594.       sqlite3VdbeAddOp4Dup8(v, OP_ColumnsUsed, pTabItem->iCursor, 0, 0,

  145595.                             (const u8*)&pTabItem->colUsed, P4_INT64);

  145596. #endif

  145597.     }else{

  145598.       sqlite3TableLock(pParse, iDb, pTab->tnum, 0, pTab->zName);

  145599.     }

  145600.     if( pLoop->wsFlags & WHERE_INDEXED ){

  145601.       Index *pIx = pLoop->u.btree.pIndex;

  145602.       int iIndexCur;

  145603.       int op = OP_OpenRead;

  145604.       /* iAuxArg is always set to a positive value if ONEPASS is possible */

  145605.       assert( iAuxArg!=0 || (pWInfo->wctrlFlags & WHERE_ONEPASS_DESIRED)==0 );

  145606.       if( !HasRowid(pTab) && IsPrimaryKeyIndex(pIx)

  145607.        && (wctrlFlags & WHERE_OR_SUBCLAUSE)!=0

  145608.       ){

  145609.         /* This is one term of an OR-optimization using the PRIMARY KEY of a

  145610.         ** WITHOUT ROWID table.  No need for a separate index */

  145611.         iIndexCur = pLevel->iTabCur;

  145612.         op = 0;

  145613.       }else if( pWInfo->eOnePass!=ONEPASS_OFF ){

  145614.         Index *pJ = pTabItem->pTab->pIndex;

  145615.         iIndexCur = iAuxArg;

  145616.         assert( wctrlFlags & WHERE_ONEPASS_DESIRED );

  145617.         while( ALWAYS(pJ) && pJ!=pIx ){

  145618.           iIndexCur++;

  145619.           pJ = pJ->pNext;

  145620.         }

  145621.         op = OP_OpenWrite;

  145622.         pWInfo->aiCurOnePass[1] = iIndexCur;

  145623.       }else if( iAuxArg && (wctrlFlags & WHERE_OR_SUBCLAUSE)!=0 ){

  145624.         iIndexCur = iAuxArg;

  145625.         op = OP_ReopenIdx;

  145626.       }else{

  145627.         iIndexCur = pParse->nTab++;

  145628.       }

  145629.       pLevel->iIdxCur = iIndexCur;

  145630.       assert( pIx->pSchema==pTab->pSchema );

  145631.       assert( iIndexCur>=0 );

  145632.       if( op ){

  145633.         sqlite3VdbeAddOp3(v, op, iIndexCur, pIx->tnum, iDb);

  145634.         sqlite3VdbeSetP4KeyInfo(pParse, pIx);

  145635.         if( (pLoop->wsFlags & WHERE_CONSTRAINT)!=0

  145636.          && (pLoop->wsFlags & (WHERE_COLUMN_RANGE|WHERE_SKIPSCAN))==0

  145637.          && (pWInfo->wctrlFlags&WHERE_ORDERBY_MIN)==0

  145638.          && pWInfo->eDistinct!=WHERE_DISTINCT_ORDERED

  145639.         ){

  145640.           sqlite3VdbeChangeP5(v, OPFLAG_SEEKEQ); /* Hint to COMDB2 */

  145641.         }

  145642.         VdbeComment((v, "%s", pIx->zName));

  145643. #ifdef SQLITE_ENABLE_COLUMN_USED_MASK

  145644.         {

  145645.           u64 colUsed = 0;

  145646.           int ii, jj;

  145647.           for(ii=0; ii<pIx->nColumn; ii++){

  145648.             jj = pIx->aiColumn[ii];

  145649.             if( jj<0 ) continue;

  145650.             if( jj>63 ) jj = 63;

  145651.             if( (pTabItem->colUsed & MASKBIT(jj))==0 ) continue;

  145652.             colUsed |= ((u64)1)<<(ii<63 ? ii : 63);

  145653.           }

  145654.           sqlite3VdbeAddOp4Dup8(v, OP_ColumnsUsed, iIndexCur, 0, 0,

  145655.                                 (u8*)&colUsed, P4_INT64);

  145656.         }

  145657. #endif /* SQLITE_ENABLE_COLUMN_USED_MASK */

  145658.       }

  145659.     }

  145660.     if( iDb>=0 ) sqlite3CodeVerifySchema(pParse, iDb);

  145661.   }

  145662.   pWInfo->iTop = sqlite3VdbeCurrentAddr(v);

  145663.   if( db->mallocFailed ) goto whereBeginError;

  145664. 

  145665.   /* Generate the code to do the search.  Each iteration of the for

  145666.   ** loop below generates code for a single nested loop of the VM

  145667.   ** program.

  145668.   */

  145669.   for(ii=0; ii<nTabList; ii++){

  145670.     int addrExplain;

  145671.     int wsFlags;

  145672.     pLevel = &pWInfo->a[ii];

  145673.     wsFlags = pLevel->pWLoop->wsFlags;

  145674. #ifndef SQLITE_OMIT_AUTOMATIC_INDEX

  145675.     if( (pLevel->pWLoop->wsFlags & WHERE_AUTO_INDEX)!=0 ){

  145676.       constructAutomaticIndex(pParse, &pWInfo->sWC,

  145677.                 &pTabList->a[pLevel->iFrom], notReady, pLevel);

  145678.       if( db->mallocFailed ) goto whereBeginError;

  145679.     }

  145680. #endif

  145681.     addrExplain = sqlite3WhereExplainOneScan(

  145682.         pParse, pTabList, pLevel, wctrlFlags

  145683.     );

  145684.     pLevel->addrBody = sqlite3VdbeCurrentAddr(v);

  145685.     notReady = sqlite3WhereCodeOneLoopStart(pParse,v,pWInfo,ii,pLevel,notReady);

  145686.     pWInfo->iContinue = pLevel->addrCont;

  145687.     if( (wsFlags&WHERE_MULTI_OR)==0 && (wctrlFlags&WHERE_OR_SUBCLAUSE)==0 ){

  145688.       sqlite3WhereAddScanStatus(v, pTabList, pLevel, addrExplain);

  145689.     }

  145690.   }

  145691. 

  145692.   /* Done. */

  145693.   VdbeModuleComment((v, "Begin WHERE-core"));

  145694.   return pWInfo;

  145695. 

  145696.   /* Jump here if malloc fails */

  145697. whereBeginError:

  145698.   if( pWInfo ){

  145699.     pParse->nQueryLoop = pWInfo->savedNQueryLoop;

  145700.     whereInfoFree(db, pWInfo);

  145701.   }

  145702.   return 0;

  145703. }

  145704. 

  145705. /*

  145706. ** Part of sqlite3WhereEnd() will rewrite opcodes to reference the

  145707. ** index rather than the main table.  In SQLITE_DEBUG mode, we want

  145708. ** to trace those changes if PRAGMA vdbe_addoptrace=on.  This routine

  145709. ** does that.

  145710. */

  145711. #ifndef SQLITE_DEBUG

  145712. # define OpcodeRewriteTrace(D,K,P) /* no-op */

  145713. #else

  145714. # define OpcodeRewriteTrace(D,K,P) sqlite3WhereOpcodeRewriteTrace(D,K,P)

  145715.   static void sqlite3WhereOpcodeRewriteTrace(

  145716.     sqlite3 *db,

  145717.     int pc,

  145718.     VdbeOp *pOp

  145719.   ){

  145720.     if( (db->flags & SQLITE_VdbeAddopTrace)==0 ) return;

  145721.     sqlite3VdbePrintOp(0, pc, pOp);

  145722.   }

  145723. #endif

  145724. 

  145725. /*

  145726. ** Generate the end of the WHERE loop.  See comments on 

  145727. ** sqlite3WhereBegin() for additional information.

  145728. */

  145729. SQLITE_PRIVATE void sqlite3WhereEnd(WhereInfo *pWInfo){

  145730.   Parse *pParse = pWInfo->pParse;

  145731.   Vdbe *v = pParse->pVdbe;

  145732.   int i;

  145733.   WhereLevel *pLevel;

  145734.   WhereLoop *pLoop;

  145735.   SrcList *pTabList = pWInfo->pTabList;

  145736.   sqlite3 *db = pParse->db;

  145737. 

  145738.   /* Generate loop termination code.

  145739.   */

  145740.   VdbeModuleComment((v, "End WHERE-core"));

  145741.   for(i=pWInfo->nLevel-1; i>=0; i--){

  145742.     int addr;

  145743.     pLevel = &pWInfo->a[i];

  145744.     pLoop = pLevel->pWLoop;

  145745.     if( pLevel->op!=OP_Noop ){

  145746. #ifndef SQLITE_DISABLE_SKIPAHEAD_DISTINCT

  145747.       int addrSeek = 0;

  145748.       Index *pIdx;

  145749.       int n;

  145750.       if( pWInfo->eDistinct==WHERE_DISTINCT_ORDERED

  145751.        && i==pWInfo->nLevel-1  /* Ticket [ef9318757b152e3] 2017-10-21 */

  145752.        && (pLoop->wsFlags & WHERE_INDEXED)!=0

  145753.        && (pIdx = pLoop->u.btree.pIndex)->hasStat1

  145754.        && (n = pLoop->u.btree.nIdxCol)>0

  145755.        && pIdx->aiRowLogEst[n]>=36

  145756.       ){

  145757.         int r1 = pParse->nMem+1;

  145758.         int j, op;

  145759.         for(j=0; j<n; j++){

  145760.           sqlite3VdbeAddOp3(v, OP_Column, pLevel->iIdxCur, j, r1+j);

  145761.         }

  145762.         pParse->nMem += n+1;

  145763.         op = pLevel->op==OP_Prev ? OP_SeekLT : OP_SeekGT;

  145764.         addrSeek = sqlite3VdbeAddOp4Int(v, op, pLevel->iIdxCur, 0, r1, n);

  145765.         VdbeCoverageIf(v, op==OP_SeekLT);

  145766.         VdbeCoverageIf(v, op==OP_SeekGT);

  145767.         sqlite3VdbeAddOp2(v, OP_Goto, 1, pLevel->p2);

  145768.       }

  145769. #endif /* SQLITE_DISABLE_SKIPAHEAD_DISTINCT */

  145770.       /* The common case: Advance to the next row */

  145771.       sqlite3VdbeResolveLabel(v, pLevel->addrCont);

  145772.       sqlite3VdbeAddOp3(v, pLevel->op, pLevel->p1, pLevel->p2, pLevel->p3);

  145773.       sqlite3VdbeChangeP5(v, pLevel->p5);

  145774.       VdbeCoverage(v);

  145775.       VdbeCoverageIf(v, pLevel->op==OP_Next);

  145776.       VdbeCoverageIf(v, pLevel->op==OP_Prev);

  145777.       VdbeCoverageIf(v, pLevel->op==OP_VNext);

  145778. #ifndef SQLITE_DISABLE_SKIPAHEAD_DISTINCT

  145779.       if( addrSeek ) sqlite3VdbeJumpHere(v, addrSeek);

  145780. #endif

  145781.     }else{

  145782.       sqlite3VdbeResolveLabel(v, pLevel->addrCont);

  145783.     }

  145784.     if( pLoop->wsFlags & WHERE_IN_ABLE && pLevel->u.in.nIn>0 ){

  145785.       struct InLoop *pIn;

  145786.       int j;

  145787.       sqlite3VdbeResolveLabel(v, pLevel->addrNxt);

  145788.       for(j=pLevel->u.in.nIn, pIn=&pLevel->u.in.aInLoop[j-1]; j>0; j--, pIn--){

  145789.         sqlite3VdbeJumpHere(v, pIn->addrInTop+1);

  145790.         if( pIn->eEndLoopOp!=OP_Noop ){

  145791.           if( pIn->nPrefix ){

  145792.             assert( pLoop->wsFlags & WHERE_IN_EARLYOUT );

  145793.             sqlite3VdbeAddOp4Int(v, OP_IfNoHope, pLevel->iIdxCur,

  145794.                               sqlite3VdbeCurrentAddr(v)+2,

  145795.                               pIn->iBase, pIn->nPrefix);

  145796.             VdbeCoverage(v);

  145797.           }

  145798.           sqlite3VdbeAddOp2(v, pIn->eEndLoopOp, pIn->iCur, pIn->addrInTop);

  145799.           VdbeCoverage(v);

  145800.           VdbeCoverageIf(v, pIn->eEndLoopOp==OP_Prev);

  145801.           VdbeCoverageIf(v, pIn->eEndLoopOp==OP_Next);

  145802.         }

  145803.         sqlite3VdbeJumpHere(v, pIn->addrInTop-1);

  145804.       }

  145805.     }

  145806.     sqlite3VdbeResolveLabel(v, pLevel->addrBrk);

  145807.     if( pLevel->addrSkip ){

  145808.       sqlite3VdbeGoto(v, pLevel->addrSkip);

  145809.       VdbeComment((v, "next skip-scan on %s", pLoop->u.btree.pIndex->zName));

  145810.       sqlite3VdbeJumpHere(v, pLevel->addrSkip);

  145811.       sqlite3VdbeJumpHere(v, pLevel->addrSkip-2);

  145812.     }

  145813. #ifndef SQLITE_LIKE_DOESNT_MATCH_BLOBS

  145814.     if( pLevel->addrLikeRep ){

  145815.       sqlite3VdbeAddOp2(v, OP_DecrJumpZero, (int)(pLevel->iLikeRepCntr>>1),

  145816.                         pLevel->addrLikeRep);

  145817.       VdbeCoverage(v);

  145818.     }

  145819. #endif

  145820.     if( pLevel->iLeftJoin ){

  145821.       int ws = pLoop->wsFlags;

  145822.       addr = sqlite3VdbeAddOp1(v, OP_IfPos, pLevel->iLeftJoin); VdbeCoverage(v);

  145823.       assert( (ws & WHERE_IDX_ONLY)==0 || (ws & WHERE_INDEXED)!=0 );

  145824.       if( (ws & WHERE_IDX_ONLY)==0 ){

  145825.         assert( pLevel->iTabCur==pTabList->a[pLevel->iFrom].iCursor );

  145826.         sqlite3VdbeAddOp1(v, OP_NullRow, pLevel->iTabCur);

  145827.       }

  145828.       if( (ws & WHERE_INDEXED) 

  145829.        || ((ws & WHERE_MULTI_OR) && pLevel->u.pCovidx) 

  145830.       ){

  145831.         sqlite3VdbeAddOp1(v, OP_NullRow, pLevel->iIdxCur);

  145832.       }

  145833.       if( pLevel->op==OP_Return ){

  145834.         sqlite3VdbeAddOp2(v, OP_Gosub, pLevel->p1, pLevel->addrFirst);

  145835.       }else{

  145836.         sqlite3VdbeGoto(v, pLevel->addrFirst);

  145837.       }

  145838.       sqlite3VdbeJumpHere(v, addr);

  145839.     }

  145840.     VdbeModuleComment((v, "End WHERE-loop%d: %s", i,

  145841.                      pWInfo->pTabList->a[pLevel->iFrom].pTab->zName));

  145842.   }

  145843. 

  145844.   /* The "break" point is here, just past the end of the outer loop.

  145845.   ** Set it.

  145846.   */

  145847.   sqlite3VdbeResolveLabel(v, pWInfo->iBreak);

  145848. 

  145849.   assert( pWInfo->nLevel<=pTabList->nSrc );

  145850.   for(i=0, pLevel=pWInfo->a; i<pWInfo->nLevel; i++, pLevel++){

  145851.     int k, last;

  145852.     VdbeOp *pOp;

  145853.     Index *pIdx = 0;

  145854.     struct SrcList_item *pTabItem = &pTabList->a[pLevel->iFrom];

  145855.     Table *pTab = pTabItem->pTab;

  145856.     assert( pTab!=0 );

  145857.     pLoop = pLevel->pWLoop;

  145858. 

  145859.     /* For a co-routine, change all OP_Column references to the table of

  145860.     ** the co-routine into OP_Copy of result contained in a register.

  145861.     ** OP_Rowid becomes OP_Null.

  145862.     */

  145863.     if( pTabItem->fg.viaCoroutine ){

  145864.       testcase( pParse->db->mallocFailed );

  145865.       translateColumnToCopy(pParse, pLevel->addrBody, pLevel->iTabCur,

  145866.                             pTabItem->regResult, 0);

  145867.       continue;

  145868.     }

  145869. 

  145870. #ifdef SQLITE_ENABLE_EARLY_CURSOR_CLOSE

  145871.     /* Close all of the cursors that were opened by sqlite3WhereBegin.

  145872.     ** Except, do not close cursors that will be reused by the OR optimization

  145873.     ** (WHERE_OR_SUBCLAUSE).  And do not close the OP_OpenWrite cursors

  145874.     ** created for the ONEPASS optimization.

  145875.     */

  145876.     if( (pTab->tabFlags & TF_Ephemeral)==0

  145877.      && pTab->pSelect==0

  145878.      && (pWInfo->wctrlFlags & WHERE_OR_SUBCLAUSE)==0

  145879.     ){

  145880.       int ws = pLoop->wsFlags;

  145881.       if( pWInfo->eOnePass==ONEPASS_OFF && (ws & WHERE_IDX_ONLY)==0 ){

  145882.         sqlite3VdbeAddOp1(v, OP_Close, pTabItem->iCursor);

  145883.       }

  145884.       if( (ws & WHERE_INDEXED)!=0

  145885.        && (ws & (WHERE_IPK|WHERE_AUTO_INDEX))==0 

  145886.        && pLevel->iIdxCur!=pWInfo->aiCurOnePass[1]

  145887.       ){

  145888.         sqlite3VdbeAddOp1(v, OP_Close, pLevel->iIdxCur);

  145889.       }

  145890.     }

  145891. #endif

  145892. 

  145893.     /* If this scan uses an index, make VDBE code substitutions to read data

  145894.     ** from the index instead of from the table where possible.  In some cases

  145895.     ** this optimization prevents the table from ever being read, which can

  145896.     ** yield a significant performance boost.

  145897.     ** 

  145898.     ** Calls to the code generator in between sqlite3WhereBegin and

  145899.     ** sqlite3WhereEnd will have created code that references the table

  145900.     ** directly.  This loop scans all that code looking for opcodes

  145901.     ** that reference the table and converts them into opcodes that

  145902.     ** reference the index.

  145903.     */

  145904.     if( pLoop->wsFlags & (WHERE_INDEXED|WHERE_IDX_ONLY) ){

  145905.       pIdx = pLoop->u.btree.pIndex;

  145906.     }else if( pLoop->wsFlags & WHERE_MULTI_OR ){

  145907.       pIdx = pLevel->u.pCovidx;

  145908.     }

  145909.     if( pIdx

  145910.      && (pWInfo->eOnePass==ONEPASS_OFF || !HasRowid(pIdx->pTable))

  145911.      && !db->mallocFailed

  145912.     ){

  145913.       last = sqlite3VdbeCurrentAddr(v);

  145914.       k = pLevel->addrBody;

  145915. #ifdef SQLITE_DEBUG

  145916.       if( db->flags & SQLITE_VdbeAddopTrace ){

  145917.         printf("TRANSLATE opcodes in range %d..%d\n", k, last-1);

  145918.       }

  145919. #endif

  145920.       pOp = sqlite3VdbeGetOp(v, k);

  145921.       for(; k<last; k++, pOp++){

  145922.         if( pOp->p1!=pLevel->iTabCur ) continue;

  145923.         if( pOp->opcode==OP_Column

  145924. #ifdef SQLITE_ENABLE_OFFSET_SQL_FUNC

  145925.          || pOp->opcode==OP_Offset

  145926. #endif

  145927.         ){

  145928.           int x = pOp->p2;

  145929.           assert( pIdx->pTable==pTab );

  145930.           if( !HasRowid(pTab) ){

  145931.             Index *pPk = sqlite3PrimaryKeyIndex(pTab);

  145932.             x = pPk->aiColumn[x];

  145933.             assert( x>=0 );

  145934.           }

  145935.           x = sqlite3ColumnOfIndex(pIdx, x);

  145936.           if( x>=0 ){

  145937.             pOp->p2 = x;

  145938.             pOp->p1 = pLevel->iIdxCur;

  145939.             OpcodeRewriteTrace(db, k, pOp);

  145940.           }

  145941.           assert( (pLoop->wsFlags & WHERE_IDX_ONLY)==0 || x>=0 

  145942.               || pWInfo->eOnePass );

  145943.         }else if( pOp->opcode==OP_Rowid ){

  145944.           pOp->p1 = pLevel->iIdxCur;

  145945.           pOp->opcode = OP_IdxRowid;

  145946.           OpcodeRewriteTrace(db, k, pOp);

  145947.         }else if( pOp->opcode==OP_IfNullRow ){

  145948.           pOp->p1 = pLevel->iIdxCur;

  145949.           OpcodeRewriteTrace(db, k, pOp);

  145950.         }

  145951.       }

  145952. #ifdef SQLITE_DEBUG

  145953.       if( db->flags & SQLITE_VdbeAddopTrace ) printf("TRANSLATE complete\n");

  145954. #endif

  145955.     }

  145956.   }

  145957. 

  145958.   /* Final cleanup

  145959.   */

  145960.   pParse->nQueryLoop = pWInfo->savedNQueryLoop;

  145961.   whereInfoFree(db, pWInfo);

  145962.   return;

  145963. }

  145964. 

  145965. /************** End of where.c ***********************************************/

  145966. /************** Begin file window.c ******************************************/

  145967. /*

  145968. ** 2018 May 08

  145969. **

  145970. ** The author disclaims copyright to this source code.  In place of

  145971. ** a legal notice, here is a blessing:

  145972. **

  145973. **    May you do good and not evil.

  145974. **    May you find forgiveness for yourself and forgive others.

  145975. **    May you share freely, never taking more than you give.

  145976. **

  145977. *************************************************************************

  145978. */

  145979. /* #include "sqliteInt.h" */

  145980. 

  145981. #ifndef SQLITE_OMIT_WINDOWFUNC

  145982. 

  145983. /*

  145984. ** SELECT REWRITING

  145985. **

  145986. **   Any SELECT statement that contains one or more window functions in

  145987. **   either the select list or ORDER BY clause (the only two places window

  145988. **   functions may be used) is transformed by function sqlite3WindowRewrite()

  145989. **   in order to support window function processing. For example, with the

  145990. **   schema:

  145991. **

  145992. **     CREATE TABLE t1(a, b, c, d, e, f, g);

  145993. **

  145994. **   the statement:

  145995. **

  145996. **     SELECT a+1, max(b) OVER (PARTITION BY c ORDER BY d) FROM t1 ORDER BY e;

  145997. **

  145998. **   is transformed to:

  145999. **

  146000. **     SELECT a+1, max(b) OVER (PARTITION BY c ORDER BY d) FROM (

  146001. **         SELECT a, e, c, d, b FROM t1 ORDER BY c, d

  146002. **     ) ORDER BY e;

  146003. **

  146004. **   The flattening optimization is disabled when processing this transformed

  146005. **   SELECT statement. This allows the implementation of the window function

  146006. **   (in this case max()) to process rows sorted in order of (c, d), which

  146007. **   makes things easier for obvious reasons. More generally:

  146008. **

  146009. **     * FROM, WHERE, GROUP BY and HAVING clauses are all moved to 

  146010. **       the sub-query.

  146011. **

  146012. **     * ORDER BY, LIMIT and OFFSET remain part of the parent query.

  146013. **

  146014. **     * Terminals from each of the expression trees that make up the 

  146015. **       select-list and ORDER BY expressions in the parent query are

  146016. **       selected by the sub-query. For the purposes of the transformation,

  146017. **       terminals are column references and aggregate functions.

  146018. **

  146019. **   If there is more than one window function in the SELECT that uses

  146020. **   the same window declaration (the OVER bit), then a single scan may

  146021. **   be used to process more than one window function. For example:

  146022. **

  146023. **     SELECT max(b) OVER (PARTITION BY c ORDER BY d), 

  146024. **            min(e) OVER (PARTITION BY c ORDER BY d) 

  146025. **     FROM t1;

  146026. **

  146027. **   is transformed in the same way as the example above. However:

  146028. **

  146029. **     SELECT max(b) OVER (PARTITION BY c ORDER BY d), 

  146030. **            min(e) OVER (PARTITION BY a ORDER BY b) 

  146031. **     FROM t1;

  146032. **

  146033. **   Must be transformed to:

  146034. **

  146035. **     SELECT max(b) OVER (PARTITION BY c ORDER BY d) FROM (

  146036. **         SELECT e, min(e) OVER (PARTITION BY a ORDER BY b), c, d, b FROM

  146037. **           SELECT a, e, c, d, b FROM t1 ORDER BY a, b

  146038. **         ) ORDER BY c, d

  146039. **     ) ORDER BY e;

  146040. **

  146041. **   so that both min() and max() may process rows in the order defined by

  146042. **   their respective window declarations.

  146043. **

  146044. ** INTERFACE WITH SELECT.C

  146045. **

  146046. **   When processing the rewritten SELECT statement, code in select.c calls

  146047. **   sqlite3WhereBegin() to begin iterating through the results of the

  146048. **   sub-query, which is always implemented as a co-routine. It then calls

  146049. **   sqlite3WindowCodeStep() to process rows and finish the scan by calling

  146050. **   sqlite3WhereEnd().

  146051. **

  146052. **   sqlite3WindowCodeStep() generates VM code so that, for each row returned

  146053. **   by the sub-query a sub-routine (OP_Gosub) coded by select.c is invoked.

  146054. **   When the sub-routine is invoked:

  146055. **

  146056. **     * The results of all window-functions for the row are stored

  146057. **       in the associated Window.regResult registers.

  146058. **

  146059. **     * The required terminal values are stored in the current row of

  146060. **       temp table Window.iEphCsr.

  146061. **

  146062. **   In some cases, depending on the window frame and the specific window

  146063. **   functions invoked, sqlite3WindowCodeStep() caches each entire partition

  146064. **   in a temp table before returning any rows. In other cases it does not.

  146065. **   This detail is encapsulated within this file, the code generated by

  146066. **   select.c is the same in either case.

  146067. **

  146068. ** BUILT-IN WINDOW FUNCTIONS

  146069. **

  146070. **   This implementation features the following built-in window functions:

  146071. **

  146072. **     row_number()

  146073. **     rank()

  146074. **     dense_rank()

  146075. **     percent_rank()

  146076. **     cume_dist()

  146077. **     ntile(N)

  146078. **     lead(expr [, offset [, default]])

  146079. **     lag(expr [, offset [, default]])

  146080. **     first_value(expr)

  146081. **     last_value(expr)

  146082. **     nth_value(expr, N)

  146083. **   

  146084. **   These are the same built-in window functions supported by Postgres. 

  146085. **   Although the behaviour of aggregate window functions (functions that

  146086. **   can be used as either aggregates or window funtions) allows them to

  146087. **   be implemented using an API, built-in window functions are much more

  146088. **   esoteric. Additionally, some window functions (e.g. nth_value()) 

  146089. **   may only be implemented by caching the entire partition in memory.

  146090. **   As such, some built-in window functions use the same API as aggregate

  146091. **   window functions and some are implemented directly using VDBE 

  146092. **   instructions. Additionally, for those functions that use the API, the

  146093. **   window frame is sometimes modified before the SELECT statement is

  146094. **   rewritten. For example, regardless of the specified window frame, the

  146095. **   row_number() function always uses:

  146096. **

  146097. **     ROWS BETWEEN UNBOUNDED PRECEDING AND CURRENT ROW

  146098. **

  146099. **   See sqlite3WindowUpdate() for details.

  146100. **

  146101. **   As well as some of the built-in window functions, aggregate window

  146102. **   functions min() and max() are implemented using VDBE instructions if

  146103. **   the start of the window frame is declared as anything other than 

  146104. **   UNBOUNDED PRECEDING.

  146105. */

  146106. 

  146107. /*

  146108. ** Implementation of built-in window function row_number(). Assumes that the

  146109. ** window frame has been coerced to:

  146110. **

  146111. **   ROWS BETWEEN UNBOUNDED PRECEDING AND CURRENT ROW

  146112. */

  146113. static void row_numberStepFunc(

  146114.   sqlite3_context *pCtx, 

  146115.   int nArg,

  146116.   sqlite3_value **apArg

  146117. ){

  146118.   i64 *p = (i64*)sqlite3_aggregate_context(pCtx, sizeof(*p));

  146119.   if( p ) (*p)++;

  146120.   UNUSED_PARAMETER(nArg);

  146121.   UNUSED_PARAMETER(apArg);

  146122. }

  146123. static void row_numberValueFunc(sqlite3_context *pCtx){

  146124.   i64 *p = (i64*)sqlite3_aggregate_context(pCtx, sizeof(*p));

  146125.   sqlite3_result_int64(pCtx, (p ? *p : 0));

  146126. }

  146127. 

  146128. /*

  146129. ** Context object type used by rank(), dense_rank(), percent_rank() and

  146130. ** cume_dist().

  146131. */

  146132. struct CallCount {

  146133.   i64 nValue;

  146134.   i64 nStep;

  146135.   i64 nTotal;

  146136. };

  146137. 

  146138. /*

  146139. ** Implementation of built-in window function dense_rank(). Assumes that

  146140. ** the window frame has been set to:

  146141. **

  146142. **   RANGE BETWEEN UNBOUNDED PRECEDING AND CURRENT ROW 

  146143. */

  146144. static void dense_rankStepFunc(

  146145.   sqlite3_context *pCtx, 

  146146.   int nArg,

  146147.   sqlite3_value **apArg

  146148. ){

  146149.   struct CallCount *p;

  146150.   p = (struct CallCount*)sqlite3_aggregate_context(pCtx, sizeof(*p));

  146151.   if( p ) p->nStep = 1;

  146152.   UNUSED_PARAMETER(nArg);

  146153.   UNUSED_PARAMETER(apArg);

  146154. }

  146155. static void dense_rankValueFunc(sqlite3_context *pCtx){

  146156.   struct CallCount *p;

  146157.   p = (struct CallCount*)sqlite3_aggregate_context(pCtx, sizeof(*p));

  146158.   if( p ){

  146159.     if( p->nStep ){

  146160.       p->nValue++;

  146161.       p->nStep = 0;

  146162.     }

  146163.     sqlite3_result_int64(pCtx, p->nValue);

  146164.   }

  146165. }

  146166. 

  146167. /*

  146168. ** Implementation of built-in window function nth_value(). This

  146169. ** implementation is used in "slow mode" only - when the EXCLUDE clause

  146170. ** is not set to the default value "NO OTHERS".

  146171. */

  146172. struct NthValueCtx {

  146173.   i64 nStep;

  146174.   sqlite3_value *pValue;

  146175. };

  146176. static void nth_valueStepFunc(

  146177.   sqlite3_context *pCtx, 

  146178.   int nArg,

  146179.   sqlite3_value **apArg

  146180. ){

  146181.   struct NthValueCtx *p;

  146182.   p = (struct NthValueCtx*)sqlite3_aggregate_context(pCtx, sizeof(*p));

  146183.   if( p ){

  146184.     i64 iVal;

  146185.     switch( sqlite3_value_numeric_type(apArg[1]) ){

  146186.       case SQLITE_INTEGER:

  146187.         iVal = sqlite3_value_int64(apArg[1]);

  146188.         break;

  146189.       case SQLITE_FLOAT: {

  146190.         double fVal = sqlite3_value_double(apArg[1]);

  146191.         if( ((i64)fVal)!=fVal ) goto error_out;

  146192.         iVal = (i64)fVal;

  146193.         break;

  146194.       }

  146195.       default:

  146196.         goto error_out;

  146197.     }

  146198.     if( iVal<=0 ) goto error_out;

  146199. 

  146200.     p->nStep++;

  146201.     if( iVal==p->nStep ){

  146202.       p->pValue = sqlite3_value_dup(apArg[0]);

  146203.       if( !p->pValue ){

  146204.         sqlite3_result_error_nomem(pCtx);

  146205.       }

  146206.     }

  146207.   }

  146208.   UNUSED_PARAMETER(nArg);

  146209.   UNUSED_PARAMETER(apArg);

  146210.   return;

  146211. 

  146212.  error_out:

  146213.   sqlite3_result_error(

  146214.       pCtx, "second argument to nth_value must be a positive integer", -1

  146215.   );

  146216. }

  146217. static void nth_valueFinalizeFunc(sqlite3_context *pCtx){

  146218.   struct NthValueCtx *p;

  146219.   p = (struct NthValueCtx*)sqlite3_aggregate_context(pCtx, 0);

  146220.   if( p && p->pValue ){

  146221.     sqlite3_result_value(pCtx, p->pValue);

  146222.     sqlite3_value_free(p->pValue);

  146223.     p->pValue = 0;

  146224.   }

  146225. }

  146226. #define nth_valueInvFunc noopStepFunc

  146227. #define nth_valueValueFunc noopValueFunc

  146228. 

  146229. static void first_valueStepFunc(

  146230.   sqlite3_context *pCtx, 

  146231.   int nArg,

  146232.   sqlite3_value **apArg

  146233. ){

  146234.   struct NthValueCtx *p;

  146235.   p = (struct NthValueCtx*)sqlite3_aggregate_context(pCtx, sizeof(*p));

  146236.   if( p && p->pValue==0 ){

  146237.     p->pValue = sqlite3_value_dup(apArg[0]);

  146238.     if( !p->pValue ){

  146239.       sqlite3_result_error_nomem(pCtx);

  146240.     }

  146241.   }

  146242.   UNUSED_PARAMETER(nArg);

  146243.   UNUSED_PARAMETER(apArg);

  146244. }

  146245. static void first_valueFinalizeFunc(sqlite3_context *pCtx){

  146246.   struct NthValueCtx *p;

  146247.   p = (struct NthValueCtx*)sqlite3_aggregate_context(pCtx, sizeof(*p));

  146248.   if( p && p->pValue ){

  146249.     sqlite3_result_value(pCtx, p->pValue);

  146250.     sqlite3_value_free(p->pValue);

  146251.     p->pValue = 0;

  146252.   }

  146253. }

  146254. #define first_valueInvFunc noopStepFunc

  146255. #define first_valueValueFunc noopValueFunc

  146256. 

  146257. /*

  146258. ** Implementation of built-in window function rank(). Assumes that

  146259. ** the window frame has been set to:

  146260. **

  146261. **   RANGE BETWEEN UNBOUNDED PRECEDING AND CURRENT ROW 

  146262. */

  146263. static void rankStepFunc(

  146264.   sqlite3_context *pCtx, 

  146265.   int nArg,

  146266.   sqlite3_value **apArg

  146267. ){

  146268.   struct CallCount *p;

  146269.   p = (struct CallCount*)sqlite3_aggregate_context(pCtx, sizeof(*p));

  146270.   if( p ){

  146271.     p->nStep++;

  146272.     if( p->nValue==0 ){

  146273.       p->nValue = p->nStep;

  146274.     }

  146275.   }

  146276.   UNUSED_PARAMETER(nArg);

  146277.   UNUSED_PARAMETER(apArg);

  146278. }

  146279. static void rankValueFunc(sqlite3_context *pCtx){

  146280.   struct CallCount *p;

  146281.   p = (struct CallCount*)sqlite3_aggregate_context(pCtx, sizeof(*p));

  146282.   if( p ){

  146283.     sqlite3_result_int64(pCtx, p->nValue);

  146284.     p->nValue = 0;

  146285.   }

  146286. }

  146287. 

  146288. /*

  146289. ** Implementation of built-in window function percent_rank(). Assumes that

  146290. ** the window frame has been set to:

  146291. **

  146292. **   GROUPS BETWEEN CURRENT ROW AND UNBOUNDED FOLLOWING

  146293. */

  146294. static void percent_rankStepFunc(

  146295.   sqlite3_context *pCtx, 

  146296.   int nArg,

  146297.   sqlite3_value **apArg

  146298. ){

  146299.   struct CallCount *p;

  146300.   UNUSED_PARAMETER(nArg); assert( nArg==0 );

  146301.   UNUSED_PARAMETER(apArg);

  146302.   p = (struct CallCount*)sqlite3_aggregate_context(pCtx, sizeof(*p));

  146303.   if( p ){

  146304.     p->nTotal++;

  146305.   }

  146306. }

  146307. static void percent_rankInvFunc(

  146308.   sqlite3_context *pCtx, 

  146309.   int nArg,

  146310.   sqlite3_value **apArg

  146311. ){

  146312.   struct CallCount *p;

  146313.   UNUSED_PARAMETER(nArg); assert( nArg==0 );

  146314.   UNUSED_PARAMETER(apArg);

  146315.   p = (struct CallCount*)sqlite3_aggregate_context(pCtx, sizeof(*p));

  146316.   p->nStep++;

  146317. }

  146318. static void percent_rankValueFunc(sqlite3_context *pCtx){

  146319.   struct CallCount *p;

  146320.   p = (struct CallCount*)sqlite3_aggregate_context(pCtx, sizeof(*p));

  146321.   if( p ){

  146322.     p->nValue = p->nStep;

  146323.     if( p->nTotal>1 ){

  146324.       double r = (double)p->nValue / (double)(p->nTotal-1);

  146325.       sqlite3_result_double(pCtx, r);

  146326.     }else{

  146327.       sqlite3_result_double(pCtx, 0.0);

  146328.     }

  146329.   }

  146330. }

  146331. #define percent_rankFinalizeFunc percent_rankValueFunc

  146332. 

  146333. /*

  146334. ** Implementation of built-in window function cume_dist(). Assumes that

  146335. ** the window frame has been set to:

  146336. **

  146337. **   GROUPS BETWEEN 1 FOLLOWING AND UNBOUNDED FOLLOWING

  146338. */

  146339. static void cume_distStepFunc(

  146340.   sqlite3_context *pCtx, 

  146341.   int nArg,

  146342.   sqlite3_value **apArg

  146343. ){

  146344.   struct CallCount *p;

  146345.   UNUSED_PARAMETER(nArg); assert( nArg==0 );

  146346.   UNUSED_PARAMETER(apArg);

  146347.   p = (struct CallCount*)sqlite3_aggregate_context(pCtx, sizeof(*p));

  146348.   if( p ){

  146349.     p->nTotal++;

  146350.   }

  146351. }

  146352. static void cume_distInvFunc(

  146353.   sqlite3_context *pCtx, 

  146354.   int nArg,

  146355.   sqlite3_value **apArg

  146356. ){

  146357.   struct CallCount *p;

  146358.   UNUSED_PARAMETER(nArg); assert( nArg==0 );

  146359.   UNUSED_PARAMETER(apArg);

  146360.   p = (struct CallCount*)sqlite3_aggregate_context(pCtx, sizeof(*p));

  146361.   p->nStep++;

  146362. }

  146363. static void cume_distValueFunc(sqlite3_context *pCtx){

  146364.   struct CallCount *p;

  146365.   p = (struct CallCount*)sqlite3_aggregate_context(pCtx, 0);

  146366.   if( p ){

  146367.     double r = (double)(p->nStep) / (double)(p->nTotal);

  146368.     sqlite3_result_double(pCtx, r);

  146369.   }

  146370. }

  146371. #define cume_distFinalizeFunc cume_distValueFunc

  146372. 

  146373. /*

  146374. ** Context object for ntile() window function.

  146375. */

  146376. struct NtileCtx {

  146377.   i64 nTotal;                     /* Total rows in partition */

  146378.   i64 nParam;                     /* Parameter passed to ntile(N) */

  146379.   i64 iRow;                       /* Current row */

  146380. };

  146381. 

  146382. /*

  146383. ** Implementation of ntile(). This assumes that the window frame has

  146384. ** been coerced to:

  146385. **

  146386. **   ROWS CURRENT ROW AND UNBOUNDED FOLLOWING

  146387. */

  146388. static void ntileStepFunc(

  146389.   sqlite3_context *pCtx, 

  146390.   int nArg,

  146391.   sqlite3_value **apArg

  146392. ){

  146393.   struct NtileCtx *p;

  146394.   assert( nArg==1 ); UNUSED_PARAMETER(nArg);

  146395.   p = (struct NtileCtx*)sqlite3_aggregate_context(pCtx, sizeof(*p));

  146396.   if( p ){

  146397.     if( p->nTotal==0 ){

  146398.       p->nParam = sqlite3_value_int64(apArg[0]);

  146399.       if( p->nParam<=0 ){

  146400.         sqlite3_result_error(

  146401.             pCtx, "argument of ntile must be a positive integer", -1

  146402.         );

  146403.       }

  146404.     }

  146405.     p->nTotal++;

  146406.   }

  146407. }

  146408. static void ntileInvFunc(

  146409.   sqlite3_context *pCtx, 

  146410.   int nArg,

  146411.   sqlite3_value **apArg

  146412. ){

  146413.   struct NtileCtx *p;

  146414.   assert( nArg==1 ); UNUSED_PARAMETER(nArg);

  146415.   UNUSED_PARAMETER(apArg);

  146416.   p = (struct NtileCtx*)sqlite3_aggregate_context(pCtx, sizeof(*p));

  146417.   p->iRow++;

  146418. }

  146419. static void ntileValueFunc(sqlite3_context *pCtx){

  146420.   struct NtileCtx *p;

  146421.   p = (struct NtileCtx*)sqlite3_aggregate_context(pCtx, sizeof(*p));

  146422.   if( p && p->nParam>0 ){

  146423.     int nSize = (p->nTotal / p->nParam);

  146424.     if( nSize==0 ){

  146425.       sqlite3_result_int64(pCtx, p->iRow+1);

  146426.     }else{

  146427.       i64 nLarge = p->nTotal - p->nParam*nSize;

  146428.       i64 iSmall = nLarge*(nSize+1);

  146429.       i64 iRow = p->iRow;

  146430. 

  146431.       assert( (nLarge*(nSize+1) + (p->nParam-nLarge)*nSize)==p->nTotal );

  146432. 

  146433.       if( iRow<iSmall ){

  146434.         sqlite3_result_int64(pCtx, 1 + iRow/(nSize+1));

  146435.       }else{

  146436.         sqlite3_result_int64(pCtx, 1 + nLarge + (iRow-iSmall)/nSize);

  146437.       }

  146438.     }

  146439.   }

  146440. }

  146441. #define ntileFinalizeFunc ntileValueFunc

  146442. 

  146443. /*

  146444. ** Context object for last_value() window function.

  146445. */

  146446. struct LastValueCtx {

  146447.   sqlite3_value *pVal;

  146448.   int nVal;

  146449. };

  146450. 

  146451. /*

  146452. ** Implementation of last_value().

  146453. */

  146454. static void last_valueStepFunc(

  146455.   sqlite3_context *pCtx, 

  146456.   int nArg,

  146457.   sqlite3_value **apArg

  146458. ){

  146459.   struct LastValueCtx *p;

  146460.   UNUSED_PARAMETER(nArg);

  146461.   p = (struct LastValueCtx*)sqlite3_aggregate_context(pCtx, sizeof(*p));

  146462.   if( p ){

  146463.     sqlite3_value_free(p->pVal);

  146464.     p->pVal = sqlite3_value_dup(apArg[0]);

  146465.     if( p->pVal==0 ){

  146466.       sqlite3_result_error_nomem(pCtx);

  146467.     }else{

  146468.       p->nVal++;

  146469.     }

  146470.   }

  146471. }

  146472. static void last_valueInvFunc(

  146473.   sqlite3_context *pCtx, 

  146474.   int nArg,

  146475.   sqlite3_value **apArg

  146476. ){

  146477.   struct LastValueCtx *p;

  146478.   UNUSED_PARAMETER(nArg);

  146479.   UNUSED_PARAMETER(apArg);

  146480.   p = (struct LastValueCtx*)sqlite3_aggregate_context(pCtx, sizeof(*p));

  146481.   if( ALWAYS(p) ){

  146482.     p->nVal--;

  146483.     if( p->nVal==0 ){

  146484.       sqlite3_value_free(p->pVal);

  146485.       p->pVal = 0;

  146486.     }

  146487.   }

  146488. }

  146489. static void last_valueValueFunc(sqlite3_context *pCtx){

  146490.   struct LastValueCtx *p;

  146491.   p = (struct LastValueCtx*)sqlite3_aggregate_context(pCtx, 0);

  146492.   if( p && p->pVal ){

  146493.     sqlite3_result_value(pCtx, p->pVal);

  146494.   }

  146495. }

  146496. static void last_valueFinalizeFunc(sqlite3_context *pCtx){

  146497.   struct LastValueCtx *p;

  146498.   p = (struct LastValueCtx*)sqlite3_aggregate_context(pCtx, sizeof(*p));

  146499.   if( p && p->pVal ){

  146500.     sqlite3_result_value(pCtx, p->pVal);

  146501.     sqlite3_value_free(p->pVal);

  146502.     p->pVal = 0;

  146503.   }

  146504. }

  146505. 

  146506. /*

  146507. ** Static names for the built-in window function names.  These static

  146508. ** names are used, rather than string literals, so that FuncDef objects

  146509. ** can be associated with a particular window function by direct

  146510. ** comparison of the zName pointer.  Example:

  146511. **

  146512. **       if( pFuncDef->zName==row_valueName ){ ... }

  146513. */

  146514. static const char row_numberName[] =   "row_number";

  146515. static const char dense_rankName[] =   "dense_rank";

  146516. static const char rankName[] =         "rank";

  146517. static const char percent_rankName[] = "percent_rank";

  146518. static const char cume_distName[] =    "cume_dist";

  146519. static const char ntileName[] =        "ntile";

  146520. static const char last_valueName[] =   "last_value";

  146521. static const char nth_valueName[] =    "nth_value";

  146522. static const char first_valueName[] =  "first_value";

  146523. static const char leadName[] =         "lead";

  146524. static const char lagName[] =          "lag";

  146525. 

  146526. /*

  146527. ** No-op implementations of xStep() and xFinalize().  Used as place-holders

  146528. ** for built-in window functions that never call those interfaces.

  146529. **

  146530. ** The noopValueFunc() is called but is expected to do nothing.  The

  146531. ** noopStepFunc() is never called, and so it is marked with NO_TEST to

  146532. ** let the test coverage routine know not to expect this function to be

  146533. ** invoked.

  146534. */

  146535. static void noopStepFunc(    /*NO_TEST*/

  146536.   sqlite3_context *p,        /*NO_TEST*/

  146537.   int n,                     /*NO_TEST*/

  146538.   sqlite3_value **a          /*NO_TEST*/

  146539. ){                           /*NO_TEST*/

  146540.   UNUSED_PARAMETER(p);       /*NO_TEST*/

  146541.   UNUSED_PARAMETER(n);       /*NO_TEST*/

  146542.   UNUSED_PARAMETER(a);       /*NO_TEST*/

  146543.   assert(0);                 /*NO_TEST*/

  146544. }                            /*NO_TEST*/

  146545. static void noopValueFunc(sqlite3_context *p){ UNUSED_PARAMETER(p); /*no-op*/ }

  146546. 

  146547. /* Window functions that use all window interfaces: xStep, xFinal,

  146548. ** xValue, and xInverse */

  146549. #define WINDOWFUNCALL(name,nArg,extra) {                                   \

  146550.   nArg, (SQLITE_UTF8|SQLITE_FUNC_WINDOW|extra), 0, 0,                      \

  146551.   name ## StepFunc, name ## FinalizeFunc, name ## ValueFunc,               \

  146552.   name ## InvFunc, name ## Name, {0}                                       \

  146553. }

  146554. 

  146555. /* Window functions that are implemented using bytecode and thus have

  146556. ** no-op routines for their methods */

  146557. #define WINDOWFUNCNOOP(name,nArg,extra) {                                  \

  146558.   nArg, (SQLITE_UTF8|SQLITE_FUNC_WINDOW|extra), 0, 0,                      \

  146559.   noopStepFunc, noopValueFunc, noopValueFunc,                              \

  146560.   noopStepFunc, name ## Name, {0}                                          \

  146561. }

  146562. 

  146563. /* Window functions that use all window interfaces: xStep, the

  146564. ** same routine for xFinalize and xValue and which never call

  146565. ** xInverse. */

  146566. #define WINDOWFUNCX(name,nArg,extra) {                                     \

  146567.   nArg, (SQLITE_UTF8|SQLITE_FUNC_WINDOW|extra), 0, 0,                      \

  146568.   name ## StepFunc, name ## ValueFunc, name ## ValueFunc,                  \

  146569.   noopStepFunc, name ## Name, {0}                                          \

  146570. }

  146571. 

  146572. 

  146573. /*

  146574. ** Register those built-in window functions that are not also aggregates.

  146575. */

  146576. SQLITE_PRIVATE void sqlite3WindowFunctions(void){

  146577.   static FuncDef aWindowFuncs[] = {

  146578.     WINDOWFUNCX(row_number, 0, 0),

  146579.     WINDOWFUNCX(dense_rank, 0, 0),

  146580.     WINDOWFUNCX(rank, 0, 0),

  146581.     WINDOWFUNCALL(percent_rank, 0, 0),

  146582.     WINDOWFUNCALL(cume_dist, 0, 0),

  146583.     WINDOWFUNCALL(ntile, 1, 0),

  146584.     WINDOWFUNCALL(last_value, 1, 0),

  146585.     WINDOWFUNCALL(nth_value, 2, 0),

  146586.     WINDOWFUNCALL(first_value, 1, 0),

  146587.     WINDOWFUNCNOOP(lead, 1, 0),

  146588.     WINDOWFUNCNOOP(lead, 2, 0),

  146589.     WINDOWFUNCNOOP(lead, 3, 0),

  146590.     WINDOWFUNCNOOP(lag, 1, 0),

  146591.     WINDOWFUNCNOOP(lag, 2, 0),

  146592.     WINDOWFUNCNOOP(lag, 3, 0),

  146593.   };

  146594.   sqlite3InsertBuiltinFuncs(aWindowFuncs, ArraySize(aWindowFuncs));

  146595. }

  146596. 

  146597. static Window *windowFind(Parse *pParse, Window *pList, const char *zName){

  146598.   Window *p;

  146599.   for(p=pList; p; p=p->pNextWin){

  146600.     if( sqlite3StrICmp(p->zName, zName)==0 ) break;

  146601.   }

  146602.   if( p==0 ){

  146603.     sqlite3ErrorMsg(pParse, "no such window: %s", zName);

  146604.   }

  146605.   return p;

  146606. }

  146607. 

  146608. /*

  146609. ** This function is called immediately after resolving the function name

  146610. ** for a window function within a SELECT statement. Argument pList is a

  146611. ** linked list of WINDOW definitions for the current SELECT statement.

  146612. ** Argument pFunc is the function definition just resolved and pWin

  146613. ** is the Window object representing the associated OVER clause. This

  146614. ** function updates the contents of pWin as follows:

  146615. **

  146616. **   * If the OVER clause refered to a named window (as in "max(x) OVER win"),

  146617. **     search list pList for a matching WINDOW definition, and update pWin

  146618. **     accordingly. If no such WINDOW clause can be found, leave an error

  146619. **     in pParse.

  146620. **

  146621. **   * If the function is a built-in window function that requires the

  146622. **     window to be coerced (see "BUILT-IN WINDOW FUNCTIONS" at the top

  146623. **     of this file), pWin is updated here.

  146624. */

  146625. SQLITE_PRIVATE void sqlite3WindowUpdate(

  146626.   Parse *pParse, 

  146627.   Window *pList,                  /* List of named windows for this SELECT */

  146628.   Window *pWin,                   /* Window frame to update */

  146629.   FuncDef *pFunc                  /* Window function definition */

  146630. ){

  146631.   if( pWin->zName && pWin->eFrmType==0 ){

  146632.     Window *p = windowFind(pParse, pList, pWin->zName);

  146633.     if( p==0 ) return;

  146634.     pWin->pPartition = sqlite3ExprListDup(pParse->db, p->pPartition, 0);

  146635.     pWin->pOrderBy = sqlite3ExprListDup(pParse->db, p->pOrderBy, 0);

  146636.     pWin->pStart = sqlite3ExprDup(pParse->db, p->pStart, 0);

  146637.     pWin->pEnd = sqlite3ExprDup(pParse->db, p->pEnd, 0);

  146638.     pWin->eStart = p->eStart;

  146639.     pWin->eEnd = p->eEnd;

  146640.     pWin->eFrmType = p->eFrmType;

  146641.     pWin->eExclude = p->eExclude;

  146642.   }else{

  146643.     sqlite3WindowChain(pParse, pWin, pList);

  146644.   }

  146645.   if( (pWin->eFrmType==TK_RANGE)

  146646.    && (pWin->pStart || pWin->pEnd) 

  146647.    && (pWin->pOrderBy==0 || pWin->pOrderBy->nExpr!=1)

  146648.   ){

  146649.     sqlite3ErrorMsg(pParse, 

  146650.       "RANGE with offset PRECEDING/FOLLOWING requires one ORDER BY expression"

  146651.     );

  146652.   }else

  146653.   if( pFunc->funcFlags & SQLITE_FUNC_WINDOW ){

  146654.     sqlite3 *db = pParse->db;

  146655.     if( pWin->pFilter ){

  146656.       sqlite3ErrorMsg(pParse, 

  146657.           "FILTER clause may only be used with aggregate window functions"

  146658.       );

  146659.     }else{

  146660.       struct WindowUpdate {

  146661.         const char *zFunc;

  146662.         int eFrmType;

  146663.         int eStart;

  146664.         int eEnd;

  146665.       } aUp[] = {

  146666.         { row_numberName,   TK_ROWS,   TK_UNBOUNDED, TK_CURRENT }, 

  146667.         { dense_rankName,   TK_RANGE,  TK_UNBOUNDED, TK_CURRENT }, 

  146668.         { rankName,         TK_RANGE,  TK_UNBOUNDED, TK_CURRENT }, 

  146669.         { percent_rankName, TK_GROUPS, TK_CURRENT,   TK_UNBOUNDED }, 

  146670.         { cume_distName,    TK_GROUPS, TK_FOLLOWING, TK_UNBOUNDED }, 

  146671.         { ntileName,        TK_ROWS,   TK_CURRENT,   TK_UNBOUNDED }, 

  146672.         { leadName,         TK_ROWS,   TK_UNBOUNDED, TK_UNBOUNDED }, 

  146673.         { lagName,          TK_ROWS,   TK_UNBOUNDED, TK_CURRENT }, 

  146674.       };

  146675.       int i;

  146676.       for(i=0; i<ArraySize(aUp); i++){

  146677.         if( pFunc->zName==aUp[i].zFunc ){

  146678.           sqlite3ExprDelete(db, pWin->pStart);

  146679.           sqlite3ExprDelete(db, pWin->pEnd);

  146680.           pWin->pEnd = pWin->pStart = 0;

  146681.           pWin->eFrmType = aUp[i].eFrmType;

  146682.           pWin->eStart = aUp[i].eStart;

  146683.           pWin->eEnd = aUp[i].eEnd;

  146684.           pWin->eExclude = 0;

  146685.           if( pWin->eStart==TK_FOLLOWING ){

  146686.             pWin->pStart = sqlite3Expr(db, TK_INTEGER, "1");

  146687.           }

  146688.           break;

  146689.         }

  146690.       }

  146691.     }

  146692.   }

  146693.   pWin->pFunc = pFunc;

  146694. }

  146695. 

  146696. /*

  146697. ** Context object passed through sqlite3WalkExprList() to

  146698. ** selectWindowRewriteExprCb() by selectWindowRewriteEList().

  146699. */

  146700. typedef struct WindowRewrite WindowRewrite;

  146701. struct WindowRewrite {

  146702.   Window *pWin;

  146703.   SrcList *pSrc;

  146704.   ExprList *pSub;

  146705.   Table *pTab;

  146706.   Select *pSubSelect;             /* Current sub-select, if any */

  146707. };

  146708. 

  146709. /*

  146710. ** Callback function used by selectWindowRewriteEList(). If necessary,

  146711. ** this function appends to the output expression-list and updates 

  146712. ** expression (*ppExpr) in place.

  146713. */

  146714. static int selectWindowRewriteExprCb(Walker *pWalker, Expr *pExpr){

  146715.   struct WindowRewrite *p = pWalker->u.pRewrite;

  146716.   Parse *pParse = pWalker->pParse;

  146717. 

  146718.   /* If this function is being called from within a scalar sub-select

  146719.   ** that used by the SELECT statement being processed, only process

  146720.   ** TK_COLUMN expressions that refer to it (the outer SELECT). Do

  146721.   ** not process aggregates or window functions at all, as they belong

  146722.   ** to the scalar sub-select.  */

  146723.   if( p->pSubSelect ){

  146724.     if( pExpr->op!=TK_COLUMN ){

  146725.       return WRC_Continue;

  146726.     }else{

  146727.       int nSrc = p->pSrc->nSrc;

  146728.       int i;

  146729.       for(i=0; i<nSrc; i++){

  146730.         if( pExpr->iTable==p->pSrc->a[i].iCursor ) break;

  146731.       }

  146732.       if( i==nSrc ) return WRC_Continue;

  146733.     }

  146734.   }

  146735. 

  146736.   switch( pExpr->op ){

  146737. 

  146738.     case TK_FUNCTION:

  146739.       if( !ExprHasProperty(pExpr, EP_WinFunc) ){

  146740.         break;

  146741.       }else{

  146742.         Window *pWin;

  146743.         for(pWin=p->pWin; pWin; pWin=pWin->pNextWin){

  146744.           if( pExpr->y.pWin==pWin ){

  146745.             assert( pWin->pOwner==pExpr );

  146746.             return WRC_Prune;

  146747.           }

  146748.         }

  146749.       }

  146750.       /* Fall through.  */

  146751. 

  146752.     case TK_AGG_FUNCTION:

  146753.     case TK_COLUMN: {

  146754.       Expr *pDup = sqlite3ExprDup(pParse->db, pExpr, 0);

  146755.       p->pSub = sqlite3ExprListAppend(pParse, p->pSub, pDup);

  146756.       if( p->pSub ){

  146757.         assert( ExprHasProperty(pExpr, EP_Static)==0 );

  146758.         ExprSetProperty(pExpr, EP_Static);

  146759.         sqlite3ExprDelete(pParse->db, pExpr);

  146760.         ExprClearProperty(pExpr, EP_Static);

  146761.         memset(pExpr, 0, sizeof(Expr));

  146762. 

  146763.         pExpr->op = TK_COLUMN;

  146764.         pExpr->iColumn = p->pSub->nExpr-1;

  146765.         pExpr->iTable = p->pWin->iEphCsr;

  146766.         pExpr->y.pTab = p->pTab;

  146767.       }

  146768. 

  146769.       break;

  146770.     }

  146771. 

  146772.     default: /* no-op */

  146773.       break;

  146774.   }

  146775. 

  146776.   return WRC_Continue;

  146777. }

  146778. static int selectWindowRewriteSelectCb(Walker *pWalker, Select *pSelect){

  146779.   struct WindowRewrite *p = pWalker->u.pRewrite;

  146780.   Select *pSave = p->pSubSelect;

  146781.   if( pSave==pSelect ){

  146782.     return WRC_Continue;

  146783.   }else{

  146784.     p->pSubSelect = pSelect;

  146785.     sqlite3WalkSelect(pWalker, pSelect);

  146786.     p->pSubSelect = pSave;

  146787.   }

  146788.   return WRC_Prune;

  146789. }

  146790. 

  146791. 

  146792. /*

  146793. ** Iterate through each expression in expression-list pEList. For each:

  146794. **

  146795. **   * TK_COLUMN,

  146796. **   * aggregate function, or

  146797. **   * window function with a Window object that is not a member of the 

  146798. **     Window list passed as the second argument (pWin).

  146799. **

  146800. ** Append the node to output expression-list (*ppSub). And replace it

  146801. ** with a TK_COLUMN that reads the (N-1)th element of table 

  146802. ** pWin->iEphCsr, where N is the number of elements in (*ppSub) after

  146803. ** appending the new one.

  146804. */

  146805. static void selectWindowRewriteEList(

  146806.   Parse *pParse, 

  146807.   Window *pWin,

  146808.   SrcList *pSrc,

  146809.   ExprList *pEList,               /* Rewrite expressions in this list */

  146810.   Table *pTab,

  146811.   ExprList **ppSub                /* IN/OUT: Sub-select expression-list */

  146812. ){

  146813.   Walker sWalker;

  146814.   WindowRewrite sRewrite;

  146815. 

  146816.   memset(&sWalker, 0, sizeof(Walker));

  146817.   memset(&sRewrite, 0, sizeof(WindowRewrite));

  146818. 

  146819.   sRewrite.pSub = *ppSub;

  146820.   sRewrite.pWin = pWin;

  146821.   sRewrite.pSrc = pSrc;

  146822.   sRewrite.pTab = pTab;

  146823. 

  146824.   sWalker.pParse = pParse;

  146825.   sWalker.xExprCallback = selectWindowRewriteExprCb;

  146826.   sWalker.xSelectCallback = selectWindowRewriteSelectCb;

  146827.   sWalker.u.pRewrite = &sRewrite;

  146828. 

  146829.   (void)sqlite3WalkExprList(&sWalker, pEList);

  146830. 

  146831.   *ppSub = sRewrite.pSub;

  146832. }

  146833. 

  146834. /*

  146835. ** Append a copy of each expression in expression-list pAppend to

  146836. ** expression list pList. Return a pointer to the result list.

  146837. */

  146838. static ExprList *exprListAppendList(

  146839.   Parse *pParse,          /* Parsing context */

  146840.   ExprList *pList,        /* List to which to append. Might be NULL */

  146841.   ExprList *pAppend,      /* List of values to append. Might be NULL */

  146842.   int bIntToNull

  146843. ){

  146844.   if( pAppend ){

  146845.     int i;

  146846.     int nInit = pList ? pList->nExpr : 0;

  146847.     for(i=0; i<pAppend->nExpr; i++){

  146848.       Expr *pDup = sqlite3ExprDup(pParse->db, pAppend->a[i].pExpr, 0);

  146849.       if( bIntToNull && pDup && pDup->op==TK_INTEGER ){

  146850.         pDup->op = TK_NULL;

  146851.         pDup->flags &= ~(EP_IntValue|EP_IsTrue|EP_IsFalse);

  146852.       }

  146853.       pList = sqlite3ExprListAppend(pParse, pList, pDup);

  146854.       if( pList ) pList->a[nInit+i].sortOrder = pAppend->a[i].sortOrder;

  146855.     }

  146856.   }

  146857.   return pList;

  146858. }

  146859. 

  146860. /*

  146861. ** If the SELECT statement passed as the second argument does not invoke

  146862. ** any SQL window functions, this function is a no-op. Otherwise, it 

  146863. ** rewrites the SELECT statement so that window function xStep functions

  146864. ** are invoked in the correct order as described under "SELECT REWRITING"

  146865. ** at the top of this file.

  146866. */

  146867. SQLITE_PRIVATE int sqlite3WindowRewrite(Parse *pParse, Select *p){

  146868.   int rc = SQLITE_OK;

  146869.   if( p->pWin && p->pPrior==0 ){

  146870.     Vdbe *v = sqlite3GetVdbe(pParse);

  146871.     sqlite3 *db = pParse->db;

  146872.     Select *pSub = 0;             /* The subquery */

  146873.     SrcList *pSrc = p->pSrc;

  146874.     Expr *pWhere = p->pWhere;

  146875.     ExprList *pGroupBy = p->pGroupBy;

  146876.     Expr *pHaving = p->pHaving;

  146877.     ExprList *pSort = 0;

  146878. 

  146879.     ExprList *pSublist = 0;       /* Expression list for sub-query */

  146880.     Window *pMWin = p->pWin;      /* Master window object */

  146881.     Window *pWin;                 /* Window object iterator */

  146882.     Table *pTab;

  146883. 

  146884.     pTab = sqlite3DbMallocZero(db, sizeof(Table));

  146885.     if( pTab==0 ){

  146886.       return SQLITE_NOMEM;

  146887.     }

  146888. 

  146889.     p->pSrc = 0;

  146890.     p->pWhere = 0;

  146891.     p->pGroupBy = 0;

  146892.     p->pHaving = 0;

  146893.     p->selFlags &= ~SF_Aggregate;

  146894. 

  146895.     /* Create the ORDER BY clause for the sub-select. This is the concatenation

  146896.     ** of the window PARTITION and ORDER BY clauses. Then, if this makes it

  146897.     ** redundant, remove the ORDER BY from the parent SELECT.  */

  146898.     pSort = sqlite3ExprListDup(db, pMWin->pPartition, 0);

  146899.     pSort = exprListAppendList(pParse, pSort, pMWin->pOrderBy, 1);

  146900.     if( pSort && p->pOrderBy ){

  146901.       if( sqlite3ExprListCompare(pSort, p->pOrderBy, -1)==0 ){

  146902.         sqlite3ExprListDelete(db, p->pOrderBy);

  146903.         p->pOrderBy = 0;

  146904.       }

  146905.     }

  146906. 

  146907.     /* Assign a cursor number for the ephemeral table used to buffer rows.

  146908.     ** The OpenEphemeral instruction is coded later, after it is known how

  146909.     ** many columns the table will have.  */

  146910.     pMWin->iEphCsr = pParse->nTab++;

  146911.     pParse->nTab += 3;

  146912. 

  146913.     selectWindowRewriteEList(pParse, pMWin, pSrc, p->pEList, pTab, &pSublist);

  146914.     selectWindowRewriteEList(pParse, pMWin, pSrc, p->pOrderBy, pTab, &pSublist);

  146915.     pMWin->nBufferCol = (pSublist ? pSublist->nExpr : 0);

  146916. 

  146917.     /* Append the PARTITION BY and ORDER BY expressions to the to the 

  146918.     ** sub-select expression list. They are required to figure out where 

  146919.     ** boundaries for partitions and sets of peer rows lie.  */

  146920.     pSublist = exprListAppendList(pParse, pSublist, pMWin->pPartition, 0);

  146921.     pSublist = exprListAppendList(pParse, pSublist, pMWin->pOrderBy, 0);

  146922. 

  146923.     /* Append the arguments passed to each window function to the

  146924.     ** sub-select expression list. Also allocate two registers for each

  146925.     ** window function - one for the accumulator, another for interim

  146926.     ** results.  */

  146927.     for(pWin=pMWin; pWin; pWin=pWin->pNextWin){

  146928.       pWin->iArgCol = (pSublist ? pSublist->nExpr : 0);

  146929.       pSublist = exprListAppendList(pParse, pSublist, pWin->pOwner->x.pList, 0);

  146930.       if( pWin->pFilter ){

  146931.         Expr *pFilter = sqlite3ExprDup(db, pWin->pFilter, 0);

  146932.         pSublist = sqlite3ExprListAppend(pParse, pSublist, pFilter);

  146933.       }

  146934.       pWin->regAccum = ++pParse->nMem;

  146935.       pWin->regResult = ++pParse->nMem;

  146936.       sqlite3VdbeAddOp2(v, OP_Null, 0, pWin->regAccum);

  146937.     }

  146938. 

  146939.     /* If there is no ORDER BY or PARTITION BY clause, and the window

  146940.     ** function accepts zero arguments, and there are no other columns

  146941.     ** selected (e.g. "SELECT row_number() OVER () FROM t1"), it is possible

  146942.     ** that pSublist is still NULL here. Add a constant expression here to 

  146943.     ** keep everything legal in this case. 

  146944.     */

  146945.     if( pSublist==0 ){

  146946.       pSublist = sqlite3ExprListAppend(pParse, 0, 

  146947.           sqlite3ExprAlloc(db, TK_INTEGER, &sqlite3IntTokens[0], 0)

  146948.       );

  146949.     }

  146950. 

  146951.     pSub = sqlite3SelectNew(

  146952.         pParse, pSublist, pSrc, pWhere, pGroupBy, pHaving, pSort, 0, 0

  146953.     );

  146954.     p->pSrc = sqlite3SrcListAppend(pParse, 0, 0, 0);

  146955.     if( p->pSrc ){

  146956.       Table *pTab2;

  146957.       p->pSrc->a[0].pSelect = pSub;

  146958.       sqlite3SrcListAssignCursors(pParse, p->pSrc);

  146959.       pSub->selFlags |= SF_Expanded;

  146960.       pTab2 = sqlite3ResultSetOfSelect(pParse, pSub);

  146961.       if( pTab2==0 ){

  146962.         rc = SQLITE_NOMEM;

  146963.       }else{

  146964.         memcpy(pTab, pTab2, sizeof(Table));

  146965.         pTab->tabFlags |= TF_Ephemeral;

  146966.         p->pSrc->a[0].pTab = pTab;

  146967.         pTab = pTab2;

  146968.       }

  146969.       sqlite3VdbeAddOp2(v, OP_OpenEphemeral, pMWin->iEphCsr, pSublist->nExpr);

  146970.       sqlite3VdbeAddOp2(v, OP_OpenDup, pMWin->iEphCsr+1, pMWin->iEphCsr);

  146971.       sqlite3VdbeAddOp2(v, OP_OpenDup, pMWin->iEphCsr+2, pMWin->iEphCsr);

  146972.       sqlite3VdbeAddOp2(v, OP_OpenDup, pMWin->iEphCsr+3, pMWin->iEphCsr);

  146973.     }else{

  146974.       sqlite3SelectDelete(db, pSub);

  146975.     }

  146976.     if( db->mallocFailed ) rc = SQLITE_NOMEM;

  146977.     sqlite3DbFree(db, pTab);

  146978.   }

  146979. 

  146980.   return rc;

  146981. }

  146982. 

  146983. /*

  146984. ** Free the Window object passed as the second argument.

  146985. */

  146986. SQLITE_PRIVATE void sqlite3WindowDelete(sqlite3 *db, Window *p){

  146987.   if( p ){

  146988.     sqlite3ExprDelete(db, p->pFilter);

  146989.     sqlite3ExprListDelete(db, p->pPartition);

  146990.     sqlite3ExprListDelete(db, p->pOrderBy);

  146991.     sqlite3ExprDelete(db, p->pEnd);

  146992.     sqlite3ExprDelete(db, p->pStart);

  146993.     sqlite3DbFree(db, p->zName);

  146994.     sqlite3DbFree(db, p->zBase);

  146995.     sqlite3DbFree(db, p);

  146996.   }

  146997. }

  146998. 

  146999. /*

  147000. ** Free the linked list of Window objects starting at the second argument.

  147001. */

  147002. SQLITE_PRIVATE void sqlite3WindowListDelete(sqlite3 *db, Window *p){

  147003.   while( p ){

  147004.     Window *pNext = p->pNextWin;

  147005.     sqlite3WindowDelete(db, p);

  147006.     p = pNext;

  147007.   }

  147008. }

  147009. 

  147010. /*

  147011. ** The argument expression is an PRECEDING or FOLLOWING offset.  The

  147012. ** value should be a non-negative integer.  If the value is not a

  147013. ** constant, change it to NULL.  The fact that it is then a non-negative

  147014. ** integer will be caught later.  But it is important not to leave

  147015. ** variable values in the expression tree.

  147016. */

  147017. static Expr *sqlite3WindowOffsetExpr(Parse *pParse, Expr *pExpr){

  147018.   if( 0==sqlite3ExprIsConstant(pExpr) ){

  147019.     if( IN_RENAME_OBJECT ) sqlite3RenameExprUnmap(pParse, pExpr);

  147020.     sqlite3ExprDelete(pParse->db, pExpr);

  147021.     pExpr = sqlite3ExprAlloc(pParse->db, TK_NULL, 0, 0);

  147022.   }

  147023.   return pExpr;

  147024. }

  147025. 

  147026. /*

  147027. ** Allocate and return a new Window object describing a Window Definition.

  147028. */

  147029. SQLITE_PRIVATE Window *sqlite3WindowAlloc(

  147030.   Parse *pParse,    /* Parsing context */

  147031.   int eType,        /* Frame type. TK_RANGE, TK_ROWS, TK_GROUPS, or 0 */

  147032.   int eStart,       /* Start type: CURRENT, PRECEDING, FOLLOWING, UNBOUNDED */

  147033.   Expr *pStart,     /* Start window size if TK_PRECEDING or FOLLOWING */

  147034.   int eEnd,         /* End type: CURRENT, FOLLOWING, TK_UNBOUNDED, PRECEDING */

  147035.   Expr *pEnd,       /* End window size if TK_FOLLOWING or PRECEDING */

  147036.   u8 eExclude       /* EXCLUDE clause */

  147037. ){

  147038.   Window *pWin = 0;

  147039.   int bImplicitFrame = 0;

  147040. 

  147041.   /* Parser assures the following: */

  147042.   assert( eType==0 || eType==TK_RANGE || eType==TK_ROWS || eType==TK_GROUPS );

  147043.   assert( eStart==TK_CURRENT || eStart==TK_PRECEDING

  147044.            || eStart==TK_UNBOUNDED || eStart==TK_FOLLOWING );

  147045.   assert( eEnd==TK_CURRENT || eEnd==TK_FOLLOWING

  147046.            || eEnd==TK_UNBOUNDED || eEnd==TK_PRECEDING );

  147047.   assert( (eStart==TK_PRECEDING || eStart==TK_FOLLOWING)==(pStart!=0) );

  147048.   assert( (eEnd==TK_FOLLOWING || eEnd==TK_PRECEDING)==(pEnd!=0) );

  147049. 

  147050.   if( eType==0 ){

  147051.     bImplicitFrame = 1;

  147052.     eType = TK_RANGE;

  147053.   }

  147054. 

  147055.   /* Additionally, the

  147056.   ** starting boundary type may not occur earlier in the following list than

  147057.   ** the ending boundary type:

  147058.   **

  147059.   **   UNBOUNDED PRECEDING

  147060.   **   <expr> PRECEDING

  147061.   **   CURRENT ROW

  147062.   **   <expr> FOLLOWING

  147063.   **   UNBOUNDED FOLLOWING

  147064.   **

  147065.   ** The parser ensures that "UNBOUNDED PRECEDING" cannot be used as an ending

  147066.   ** boundary, and than "UNBOUNDED FOLLOWING" cannot be used as a starting

  147067.   ** frame boundary.

  147068.   */

  147069.   if( (eStart==TK_CURRENT && eEnd==TK_PRECEDING)

  147070.    || (eStart==TK_FOLLOWING && (eEnd==TK_PRECEDING || eEnd==TK_CURRENT))

  147071.   ){

  147072.     sqlite3ErrorMsg(pParse, "unsupported frame specification");

  147073.     goto windowAllocErr;

  147074.   }

  147075. 

  147076.   pWin = (Window*)sqlite3DbMallocZero(pParse->db, sizeof(Window));

  147077.   if( pWin==0 ) goto windowAllocErr;

  147078.   pWin->eFrmType = eType;

  147079.   pWin->eStart = eStart;

  147080.   pWin->eEnd = eEnd;

  147081.   if( eExclude==0 && OptimizationDisabled(pParse->db, SQLITE_WindowFunc) ){

  147082.     eExclude = TK_NO;

  147083.   }

  147084.   pWin->eExclude = eExclude;

  147085.   pWin->bImplicitFrame = bImplicitFrame;

  147086.   pWin->pEnd = sqlite3WindowOffsetExpr(pParse, pEnd);

  147087.   pWin->pStart = sqlite3WindowOffsetExpr(pParse, pStart);

  147088.   return pWin;

  147089. 

  147090. windowAllocErr:

  147091.   sqlite3ExprDelete(pParse->db, pEnd);

  147092.   sqlite3ExprDelete(pParse->db, pStart);

  147093.   return 0;

  147094. }

  147095. 

  147096. /*

  147097. ** Attach PARTITION and ORDER BY clauses pPartition and pOrderBy to window

  147098. ** pWin. Also, if parameter pBase is not NULL, set pWin->zBase to the

  147099. ** equivalent nul-terminated string.

  147100. */

  147101. SQLITE_PRIVATE Window *sqlite3WindowAssemble(

  147102.   Parse *pParse, 

  147103.   Window *pWin, 

  147104.   ExprList *pPartition, 

  147105.   ExprList *pOrderBy, 

  147106.   Token *pBase

  147107. ){

  147108.   if( pWin ){

  147109.     pWin->pPartition = pPartition;

  147110.     pWin->pOrderBy = pOrderBy;

  147111.     if( pBase ){

  147112.       pWin->zBase = sqlite3DbStrNDup(pParse->db, pBase->z, pBase->n);

  147113.     }

  147114.   }else{

  147115.     sqlite3ExprListDelete(pParse->db, pPartition);

  147116.     sqlite3ExprListDelete(pParse->db, pOrderBy);

  147117.   }

  147118.   return pWin;

  147119. }

  147120. 

  147121. /*

  147122. ** Window *pWin has just been created from a WINDOW clause. Tokne pBase

  147123. ** is the base window. Earlier windows from the same WINDOW clause are

  147124. ** stored in the linked list starting at pWin->pNextWin. This function

  147125. ** either updates *pWin according to the base specification, or else

  147126. ** leaves an error in pParse.

  147127. */

  147128. SQLITE_PRIVATE void sqlite3WindowChain(Parse *pParse, Window *pWin, Window *pList){

  147129.   if( pWin->zBase ){

  147130.     sqlite3 *db = pParse->db;

  147131.     Window *pExist = windowFind(pParse, pList, pWin->zBase);

  147132.     if( pExist ){

  147133.       const char *zErr = 0;

  147134.       /* Check for errors */

  147135.       if( pWin->pPartition ){

  147136.         zErr = "PARTITION clause";

  147137.       }else if( pExist->pOrderBy && pWin->pOrderBy ){

  147138.         zErr = "ORDER BY clause";

  147139.       }else if( pExist->bImplicitFrame==0 ){

  147140.         zErr = "frame specification";

  147141.       }

  147142.       if( zErr ){

  147143.         sqlite3ErrorMsg(pParse, 

  147144.             "cannot override %s of window: %s", zErr, pWin->zBase

  147145.         );

  147146.       }else{

  147147.         pWin->pPartition = sqlite3ExprListDup(db, pExist->pPartition, 0);

  147148.         if( pExist->pOrderBy ){

  147149.           assert( pWin->pOrderBy==0 );

  147150.           pWin->pOrderBy = sqlite3ExprListDup(db, pExist->pOrderBy, 0);

  147151.         }

  147152.         sqlite3DbFree(db, pWin->zBase);

  147153.         pWin->zBase = 0;

  147154.       }

  147155.     }

  147156.   }

  147157. }

  147158. 

  147159. /*

  147160. ** Attach window object pWin to expression p.

  147161. */

  147162. SQLITE_PRIVATE void sqlite3WindowAttach(Parse *pParse, Expr *p, Window *pWin){

  147163.   if( p ){

  147164.     assert( p->op==TK_FUNCTION );

  147165.     /* This routine is only called for the parser.  If pWin was not

  147166.     ** allocated due to an OOM, then the parser would fail before ever

  147167.     ** invoking this routine */

  147168.     if( ALWAYS(pWin) ){

  147169.       p->y.pWin = pWin;

  147170.       ExprSetProperty(p, EP_WinFunc);

  147171.       pWin->pOwner = p;

  147172.       if( p->flags & EP_Distinct ){

  147173.         sqlite3ErrorMsg(pParse,

  147174.            "DISTINCT is not supported for window functions");

  147175.       }

  147176.     }

  147177.   }else{

  147178.     sqlite3WindowDelete(pParse->db, pWin);

  147179.   }

  147180. }

  147181. 

  147182. /*

  147183. ** Return 0 if the two window objects are identical, or non-zero otherwise.

  147184. ** Identical window objects can be processed in a single scan.

  147185. */

  147186. SQLITE_PRIVATE int sqlite3WindowCompare(Parse *pParse, Window *p1, Window *p2){

  147187.   if( p1->eFrmType!=p2->eFrmType ) return 1;

  147188.   if( p1->eStart!=p2->eStart ) return 1;

  147189.   if( p1->eEnd!=p2->eEnd ) return 1;

  147190.   if( p1->eExclude!=p2->eExclude ) return 1;

  147191.   if( sqlite3ExprCompare(pParse, p1->pStart, p2->pStart, -1) ) return 1;

  147192.   if( sqlite3ExprCompare(pParse, p1->pEnd, p2->pEnd, -1) ) return 1;

  147193.   if( sqlite3ExprListCompare(p1->pPartition, p2->pPartition, -1) ) return 1;

  147194.   if( sqlite3ExprListCompare(p1->pOrderBy, p2->pOrderBy, -1) ) return 1;

  147195.   return 0;

  147196. }

  147197. 

  147198. 

  147199. /*

  147200. ** This is called by code in select.c before it calls sqlite3WhereBegin()

  147201. ** to begin iterating through the sub-query results. It is used to allocate

  147202. ** and initialize registers and cursors used by sqlite3WindowCodeStep().

  147203. */

  147204. SQLITE_PRIVATE void sqlite3WindowCodeInit(Parse *pParse, Window *pMWin){

  147205.   Window *pWin;

  147206.   Vdbe *v = sqlite3GetVdbe(pParse);

  147207. 

  147208.   /* Allocate registers to use for PARTITION BY values, if any. Initialize

  147209.   ** said registers to NULL.  */

  147210.   if( pMWin->pPartition ){

  147211.     int nExpr = pMWin->pPartition->nExpr;

  147212.     pMWin->regPart = pParse->nMem+1;

  147213.     pParse->nMem += nExpr;

  147214.     sqlite3VdbeAddOp3(v, OP_Null, 0, pMWin->regPart, pMWin->regPart+nExpr-1);

  147215.   }

  147216. 

  147217.   pMWin->regOne = ++pParse->nMem;

  147218.   sqlite3VdbeAddOp2(v, OP_Integer, 1, pMWin->regOne);

  147219. 

  147220.   if( pMWin->eExclude ){

  147221.     pMWin->regStartRowid = ++pParse->nMem;

  147222.     pMWin->regEndRowid = ++pParse->nMem;

  147223.     pMWin->csrApp = pParse->nTab++;

  147224.     sqlite3VdbeAddOp2(v, OP_Integer, 1, pMWin->regStartRowid);

  147225.     sqlite3VdbeAddOp2(v, OP_Integer, 0, pMWin->regEndRowid);

  147226.     sqlite3VdbeAddOp2(v, OP_OpenDup, pMWin->csrApp, pMWin->iEphCsr);

  147227.     return;

  147228.   }

  147229. 

  147230.   for(pWin=pMWin; pWin; pWin=pWin->pNextWin){

  147231.     FuncDef *p = pWin->pFunc;

  147232.     if( (p->funcFlags & SQLITE_FUNC_MINMAX) && pWin->eStart!=TK_UNBOUNDED ){

  147233.       /* The inline versions of min() and max() require a single ephemeral

  147234.       ** table and 3 registers. The registers are used as follows:

  147235.       **

  147236.       **   regApp+0: slot to copy min()/max() argument to for MakeRecord

  147237.       **   regApp+1: integer value used to ensure keys are unique

  147238.       **   regApp+2: output of MakeRecord

  147239.       */

  147240.       ExprList *pList = pWin->pOwner->x.pList;

  147241.       KeyInfo *pKeyInfo = sqlite3KeyInfoFromExprList(pParse, pList, 0, 0);

  147242.       pWin->csrApp = pParse->nTab++;

  147243.       pWin->regApp = pParse->nMem+1;

  147244.       pParse->nMem += 3;

  147245.       if( pKeyInfo && pWin->pFunc->zName[1]=='i' ){

  147246.         assert( pKeyInfo->aSortOrder[0]==0 );

  147247.         pKeyInfo->aSortOrder[0] = 1;

  147248.       }

  147249.       sqlite3VdbeAddOp2(v, OP_OpenEphemeral, pWin->csrApp, 2);

  147250.       sqlite3VdbeAppendP4(v, pKeyInfo, P4_KEYINFO);

  147251.       sqlite3VdbeAddOp2(v, OP_Integer, 0, pWin->regApp+1);

  147252.     }

  147253.     else if( p->zName==nth_valueName || p->zName==first_valueName ){

  147254.       /* Allocate two registers at pWin->regApp. These will be used to

  147255.       ** store the start and end index of the current frame.  */

  147256.       pWin->regApp = pParse->nMem+1;

  147257.       pWin->csrApp = pParse->nTab++;

  147258.       pParse->nMem += 2;

  147259.       sqlite3VdbeAddOp2(v, OP_OpenDup, pWin->csrApp, pMWin->iEphCsr);

  147260.     }

  147261.     else if( p->zName==leadName || p->zName==lagName ){

  147262.       pWin->csrApp = pParse->nTab++;

  147263.       sqlite3VdbeAddOp2(v, OP_OpenDup, pWin->csrApp, pMWin->iEphCsr);

  147264.     }

  147265.   }

  147266. }

  147267. 

  147268. #define WINDOW_STARTING_INT  0

  147269. #define WINDOW_ENDING_INT    1

  147270. #define WINDOW_NTH_VALUE_INT 2

  147271. #define WINDOW_STARTING_NUM  3

  147272. #define WINDOW_ENDING_NUM    4

  147273. 

  147274. /*

  147275. ** A "PRECEDING <expr>" (eCond==0) or "FOLLOWING <expr>" (eCond==1) or the

  147276. ** value of the second argument to nth_value() (eCond==2) has just been

  147277. ** evaluated and the result left in register reg. This function generates VM

  147278. ** code to check that the value is a non-negative integer and throws an

  147279. ** exception if it is not.

  147280. */

  147281. static void windowCheckValue(Parse *pParse, int reg, int eCond){

  147282.   static const char *azErr[] = {

  147283.     "frame starting offset must be a non-negative integer",

  147284.     "frame ending offset must be a non-negative integer",

  147285.     "second argument to nth_value must be a positive integer",

  147286.     "frame starting offset must be a non-negative number",

  147287.     "frame ending offset must be a non-negative number",

  147288.   };

  147289.   static int aOp[] = { OP_Ge, OP_Ge, OP_Gt, OP_Ge, OP_Ge };

  147290.   Vdbe *v = sqlite3GetVdbe(pParse);

  147291.   int regZero = sqlite3GetTempReg(pParse);

  147292.   assert( eCond>=0 && eCond<ArraySize(azErr) );

  147293.   sqlite3VdbeAddOp2(v, OP_Integer, 0, regZero);

  147294.   if( eCond>=WINDOW_STARTING_NUM ){

  147295.     int regString = sqlite3GetTempReg(pParse);

  147296.     sqlite3VdbeAddOp4(v, OP_String8, 0, regString, 0, "", P4_STATIC);

  147297.     sqlite3VdbeAddOp3(v, OP_Ge, regString, sqlite3VdbeCurrentAddr(v)+2, reg);

  147298.     sqlite3VdbeChangeP5(v, SQLITE_AFF_NUMERIC|SQLITE_JUMPIFNULL);

  147299.     VdbeCoverage(v);

  147300.     assert( eCond==3 || eCond==4 );

  147301.     VdbeCoverageIf(v, eCond==3);

  147302.     VdbeCoverageIf(v, eCond==4);

  147303.   }else{

  147304.     sqlite3VdbeAddOp2(v, OP_MustBeInt, reg, sqlite3VdbeCurrentAddr(v)+2);

  147305.     VdbeCoverage(v);

  147306.     assert( eCond==0 || eCond==1 || eCond==2 );

  147307.     VdbeCoverageIf(v, eCond==0);

  147308.     VdbeCoverageIf(v, eCond==1);

  147309.     VdbeCoverageIf(v, eCond==2);

  147310.   }

  147311.   sqlite3VdbeAddOp3(v, aOp[eCond], regZero, sqlite3VdbeCurrentAddr(v)+2, reg);

  147312.   VdbeCoverageNeverNullIf(v, eCond==0); /* NULL case captured by */

  147313.   VdbeCoverageNeverNullIf(v, eCond==1); /*   the OP_MustBeInt */

  147314.   VdbeCoverageNeverNullIf(v, eCond==2);

  147315.   VdbeCoverageNeverNullIf(v, eCond==3); /* NULL case caught by */

  147316.   VdbeCoverageNeverNullIf(v, eCond==4); /*   the OP_Ge */

  147317.   sqlite3MayAbort(pParse);

  147318.   sqlite3VdbeAddOp2(v, OP_Halt, SQLITE_ERROR, OE_Abort);

  147319.   sqlite3VdbeAppendP4(v, (void*)azErr[eCond], P4_STATIC);

  147320.   sqlite3ReleaseTempReg(pParse, regZero);

  147321. }

  147322. 

  147323. /*

  147324. ** Return the number of arguments passed to the window-function associated

  147325. ** with the object passed as the only argument to this function.

  147326. */

  147327. static int windowArgCount(Window *pWin){

  147328.   ExprList *pList = pWin->pOwner->x.pList;

  147329.   return (pList ? pList->nExpr : 0);

  147330. }

  147331. 

  147332. /*

  147333. ** Generate VM code to invoke either xStep() (if bInverse is 0) or 

  147334. ** xInverse (if bInverse is non-zero) for each window function in the 

  147335. ** linked list starting at pMWin. Or, for built-in window functions

  147336. ** that do not use the standard function API, generate the required

  147337. ** inline VM code.

  147338. **

  147339. ** If argument csr is greater than or equal to 0, then argument reg is

  147340. ** the first register in an array of registers guaranteed to be large

  147341. ** enough to hold the array of arguments for each function. In this case

  147342. ** the arguments are extracted from the current row of csr into the

  147343. ** array of registers before invoking OP_AggStep or OP_AggInverse

  147344. **

  147345. ** Or, if csr is less than zero, then the array of registers at reg is

  147346. ** already populated with all columns from the current row of the sub-query.

  147347. **

  147348. ** If argument regPartSize is non-zero, then it is a register containing the

  147349. ** number of rows in the current partition.

  147350. */

  147351. static void windowAggStep(

  147352.   Parse *pParse, 

  147353.   Window *pMWin,                  /* Linked list of window functions */

  147354.   int csr,                        /* Read arguments from this cursor */

  147355.   int bInverse,                   /* True to invoke xInverse instead of xStep */

  147356.   int reg                         /* Array of registers */

  147357. ){

  147358.   Vdbe *v = sqlite3GetVdbe(pParse);

  147359.   Window *pWin;

  147360.   for(pWin=pMWin; pWin; pWin=pWin->pNextWin){

  147361.     FuncDef *pFunc = pWin->pFunc;

  147362.     int regArg;

  147363.     int nArg = windowArgCount(pWin);

  147364.     int i;

  147365. 

  147366.     for(i=0; i<nArg; i++){

  147367.       if( i!=1 || pFunc->zName!=nth_valueName ){

  147368.         sqlite3VdbeAddOp3(v, OP_Column, csr, pWin->iArgCol+i, reg+i);

  147369.       }else{

  147370.         sqlite3VdbeAddOp3(v, OP_Column, pMWin->iEphCsr, pWin->iArgCol+i, reg+i);

  147371.       }

  147372.     }

  147373.     regArg = reg;

  147374. 

  147375.     if( pMWin->regStartRowid==0

  147376.      && (pFunc->funcFlags & SQLITE_FUNC_MINMAX) 

  147377.      && (pWin->eStart!=TK_UNBOUNDED)

  147378.     ){

  147379.       int addrIsNull = sqlite3VdbeAddOp1(v, OP_IsNull, regArg);

  147380.       VdbeCoverage(v);

  147381.       if( bInverse==0 ){

  147382.         sqlite3VdbeAddOp2(v, OP_AddImm, pWin->regApp+1, 1);

  147383.         sqlite3VdbeAddOp2(v, OP_SCopy, regArg, pWin->regApp);

  147384.         sqlite3VdbeAddOp3(v, OP_MakeRecord, pWin->regApp, 2, pWin->regApp+2);

  147385.         sqlite3VdbeAddOp2(v, OP_IdxInsert, pWin->csrApp, pWin->regApp+2);

  147386.       }else{

  147387.         sqlite3VdbeAddOp4Int(v, OP_SeekGE, pWin->csrApp, 0, regArg, 1);

  147388.         VdbeCoverageNeverTaken(v);

  147389.         sqlite3VdbeAddOp1(v, OP_Delete, pWin->csrApp);

  147390.         sqlite3VdbeJumpHere(v, sqlite3VdbeCurrentAddr(v)-2);

  147391.       }

  147392.       sqlite3VdbeJumpHere(v, addrIsNull);

  147393.     }else if( pWin->regApp ){

  147394.       assert( pFunc->zName==nth_valueName

  147395.            || pFunc->zName==first_valueName

  147396.       );

  147397.       assert( bInverse==0 || bInverse==1 );

  147398.       sqlite3VdbeAddOp2(v, OP_AddImm, pWin->regApp+1-bInverse, 1);

  147399.     }else if( pFunc->xSFunc!=noopStepFunc ){

  147400.       int addrIf = 0;

  147401.       if( pWin->pFilter ){

  147402.         int regTmp;

  147403.         assert( nArg==0 || nArg==pWin->pOwner->x.pList->nExpr );

  147404.         assert( nArg || pWin->pOwner->x.pList==0 );

  147405.         regTmp = sqlite3GetTempReg(pParse);

  147406.         sqlite3VdbeAddOp3(v, OP_Column, csr, pWin->iArgCol+nArg,regTmp);

  147407.         addrIf = sqlite3VdbeAddOp3(v, OP_IfNot, regTmp, 0, 1);

  147408.         VdbeCoverage(v);

  147409.         sqlite3ReleaseTempReg(pParse, regTmp);

  147410.       }

  147411.       if( pFunc->funcFlags & SQLITE_FUNC_NEEDCOLL ){

  147412.         CollSeq *pColl;

  147413.         assert( nArg>0 );

  147414.         pColl = sqlite3ExprNNCollSeq(pParse, pWin->pOwner->x.pList->a[0].pExpr);

  147415.         sqlite3VdbeAddOp4(v, OP_CollSeq, 0,0,0, (const char*)pColl, P4_COLLSEQ);

  147416.       }

  147417.       sqlite3VdbeAddOp3(v, bInverse? OP_AggInverse : OP_AggStep, 

  147418.                         bInverse, regArg, pWin->regAccum);

  147419.       sqlite3VdbeAppendP4(v, pFunc, P4_FUNCDEF);

  147420.       sqlite3VdbeChangeP5(v, (u8)nArg);

  147421.       if( addrIf ) sqlite3VdbeJumpHere(v, addrIf);

  147422.     }

  147423.   }

  147424. }

  147425. 

  147426. typedef struct WindowCodeArg WindowCodeArg;

  147427. typedef struct WindowCsrAndReg WindowCsrAndReg;

  147428. struct WindowCsrAndReg {

  147429.   int csr;

  147430.   int reg;

  147431. };

  147432. 

  147433. struct WindowCodeArg {

  147434.   Parse *pParse;

  147435.   Window *pMWin;

  147436.   Vdbe *pVdbe;

  147437.   int regGosub;

  147438.   int addrGosub;

  147439.   int regArg;

  147440.   int eDelete;

  147441. 

  147442.   WindowCsrAndReg start;

  147443.   WindowCsrAndReg current;

  147444.   WindowCsrAndReg end;

  147445. };

  147446. 

  147447. /*

  147448. ** Values that may be passed as the second argument to windowCodeOp().

  147449. */

  147450. #define WINDOW_RETURN_ROW 1

  147451. #define WINDOW_AGGINVERSE 2

  147452. #define WINDOW_AGGSTEP    3

  147453. 

  147454. /*

  147455. ** Generate VM code to read the window frames peer values from cursor csr into

  147456. ** an array of registers starting at reg.

  147457. */

  147458. static void windowReadPeerValues(

  147459.   WindowCodeArg *p,

  147460.   int csr,

  147461.   int reg

  147462. ){

  147463.   Window *pMWin = p->pMWin;

  147464.   ExprList *pOrderBy = pMWin->pOrderBy;

  147465.   if( pOrderBy ){

  147466.     Vdbe *v = sqlite3GetVdbe(p->pParse);

  147467.     ExprList *pPart = pMWin->pPartition;

  147468.     int iColOff = pMWin->nBufferCol + (pPart ? pPart->nExpr : 0);

  147469.     int i;

  147470.     for(i=0; i<pOrderBy->nExpr; i++){

  147471.       sqlite3VdbeAddOp3(v, OP_Column, csr, iColOff+i, reg+i);

  147472.     }

  147473.   }

  147474. }

  147475. 

  147476. /*

  147477. ** Generate VM code to invoke either xValue() (bFin==0) or xFinalize()

  147478. ** (bFin==1) for each window function in the linked list starting at

  147479. ** pMWin. Or, for built-in window-functions that do not use the standard

  147480. ** API, generate the equivalent VM code.

  147481. */

  147482. static void windowAggFinal(WindowCodeArg *p, int bFin){

  147483.   Parse *pParse = p->pParse;

  147484.   Window *pMWin = p->pMWin;

  147485.   Vdbe *v = sqlite3GetVdbe(pParse);

  147486.   Window *pWin;

  147487. 

  147488.   for(pWin=pMWin; pWin; pWin=pWin->pNextWin){

  147489.     if( pMWin->regStartRowid==0

  147490.      && (pWin->pFunc->funcFlags & SQLITE_FUNC_MINMAX) 

  147491.      && (pWin->eStart!=TK_UNBOUNDED)

  147492.     ){

  147493.       sqlite3VdbeAddOp2(v, OP_Null, 0, pWin->regResult);

  147494.       sqlite3VdbeAddOp1(v, OP_Last, pWin->csrApp);

  147495.       VdbeCoverage(v);

  147496.       sqlite3VdbeAddOp3(v, OP_Column, pWin->csrApp, 0, pWin->regResult);

  147497.       sqlite3VdbeJumpHere(v, sqlite3VdbeCurrentAddr(v)-2);

  147498.     }else if( pWin->regApp ){

  147499.       assert( pMWin->regStartRowid==0 );

  147500.     }else{

  147501.       int nArg = windowArgCount(pWin);

  147502.       if( bFin ){

  147503.         sqlite3VdbeAddOp2(v, OP_AggFinal, pWin->regAccum, nArg);

  147504.         sqlite3VdbeAppendP4(v, pWin->pFunc, P4_FUNCDEF);

  147505.         sqlite3VdbeAddOp2(v, OP_Copy, pWin->regAccum, pWin->regResult);

  147506.         sqlite3VdbeAddOp2(v, OP_Null, 0, pWin->regAccum);

  147507.       }else{

  147508.         sqlite3VdbeAddOp3(v, OP_AggValue,pWin->regAccum,nArg,pWin->regResult);

  147509.         sqlite3VdbeAppendP4(v, pWin->pFunc, P4_FUNCDEF);

  147510.       }

  147511.     }

  147512.   }

  147513. }

  147514. 

  147515. /*

  147516. ** Generate code to calculate the current values of all window functions in the

  147517. ** p->pMWin list by doing a full scan of the current window frame. Store the

  147518. ** results in the Window.regResult registers, ready to return the upper

  147519. ** layer.

  147520. */

  147521. static void windowFullScan(WindowCodeArg *p){

  147522.   Window *pWin;

  147523.   Parse *pParse = p->pParse;

  147524.   Window *pMWin = p->pMWin;

  147525.   Vdbe *v = p->pVdbe;

  147526. 

  147527.   int regCRowid = 0;              /* Current rowid value */

  147528.   int regCPeer = 0;               /* Current peer values */

  147529.   int regRowid = 0;               /* AggStep rowid value */

  147530.   int regPeer = 0;                /* AggStep peer values */

  147531. 

  147532.   int nPeer;

  147533.   int lblNext;

  147534.   int lblBrk;

  147535.   int addrNext;

  147536.   int csr = pMWin->csrApp;

  147537. 

  147538.   nPeer = (pMWin->pOrderBy ? pMWin->pOrderBy->nExpr : 0);

  147539. 

  147540.   lblNext = sqlite3VdbeMakeLabel(pParse);

  147541.   lblBrk = sqlite3VdbeMakeLabel(pParse);

  147542. 

  147543.   regCRowid = sqlite3GetTempReg(pParse);

  147544.   regRowid = sqlite3GetTempReg(pParse);

  147545.   if( nPeer ){

  147546.     regCPeer = sqlite3GetTempRange(pParse, nPeer);

  147547.     regPeer = sqlite3GetTempRange(pParse, nPeer);

  147548.   }

  147549. 

  147550.   sqlite3VdbeAddOp2(v, OP_Rowid, pMWin->iEphCsr, regCRowid);

  147551.   windowReadPeerValues(p, pMWin->iEphCsr, regCPeer);

  147552. 

  147553.   for(pWin=pMWin; pWin; pWin=pWin->pNextWin){

  147554.     sqlite3VdbeAddOp2(v, OP_Null, 0, pWin->regAccum);

  147555.   }

  147556. 

  147557.   sqlite3VdbeAddOp3(v, OP_SeekGE, csr, lblBrk, pMWin->regStartRowid);

  147558.   VdbeCoverage(v);

  147559.   addrNext = sqlite3VdbeCurrentAddr(v);

  147560.   sqlite3VdbeAddOp2(v, OP_Rowid, csr, regRowid);

  147561.   sqlite3VdbeAddOp3(v, OP_Gt, pMWin->regEndRowid, lblBrk, regRowid);

  147562.   VdbeCoverageNeverNull(v);

  147563. 

  147564.   if( pMWin->eExclude==TK_CURRENT ){

  147565.     sqlite3VdbeAddOp3(v, OP_Eq, regCRowid, lblNext, regRowid);

  147566.     VdbeCoverageNeverNull(v);

  147567.   }else if( pMWin->eExclude!=TK_NO ){

  147568.     int addr;

  147569.     int addrEq = 0;

  147570.     KeyInfo *pKeyInfo = 0;

  147571. 

  147572.     if( pMWin->pOrderBy ){

  147573.       pKeyInfo = sqlite3KeyInfoFromExprList(pParse, pMWin->pOrderBy, 0, 0);

  147574.     }

  147575.     if( pMWin->eExclude==TK_TIES ){

  147576.       addrEq = sqlite3VdbeAddOp3(v, OP_Eq, regCRowid, 0, regRowid);

  147577.       VdbeCoverageNeverNull(v);

  147578.     }

  147579.     if( pKeyInfo ){

  147580.       windowReadPeerValues(p, csr, regPeer);

  147581.       sqlite3VdbeAddOp3(v, OP_Compare, regPeer, regCPeer, nPeer);

  147582.       sqlite3VdbeAppendP4(v, (void*)pKeyInfo, P4_KEYINFO);

  147583.       addr = sqlite3VdbeCurrentAddr(v)+1;

  147584.       sqlite3VdbeAddOp3(v, OP_Jump, addr, lblNext, addr);

  147585.       VdbeCoverageEqNe(v);

  147586.     }else{

  147587.       sqlite3VdbeAddOp2(v, OP_Goto, 0, lblNext);

  147588.     }

  147589.     if( addrEq ) sqlite3VdbeJumpHere(v, addrEq);

  147590.   }

  147591. 

  147592.   windowAggStep(pParse, pMWin, csr, 0, p->regArg);

  147593. 

  147594.   sqlite3VdbeResolveLabel(v, lblNext);

  147595.   sqlite3VdbeAddOp2(v, OP_Next, csr, addrNext);

  147596.   VdbeCoverage(v);

  147597.   sqlite3VdbeJumpHere(v, addrNext-1);

  147598.   sqlite3VdbeJumpHere(v, addrNext+1);

  147599.   sqlite3ReleaseTempReg(pParse, regRowid);

  147600.   sqlite3ReleaseTempReg(pParse, regCRowid);

  147601.   if( nPeer ){

  147602.     sqlite3ReleaseTempRange(pParse, regPeer, nPeer);

  147603.     sqlite3ReleaseTempRange(pParse, regCPeer, nPeer);

  147604.   }

  147605. 

  147606.   windowAggFinal(p, 1);

  147607. }

  147608. 

  147609. /*

  147610. ** Invoke the sub-routine at regGosub (generated by code in select.c) to

  147611. ** return the current row of Window.iEphCsr. If all window functions are

  147612. ** aggregate window functions that use the standard API, a single

  147613. ** OP_Gosub instruction is all that this routine generates. Extra VM code

  147614. ** for per-row processing is only generated for the following built-in window

  147615. ** functions:

  147616. **

  147617. **   nth_value()

  147618. **   first_value()

  147619. **   lag()

  147620. **   lead()

  147621. */

  147622. static void windowReturnOneRow(WindowCodeArg *p){

  147623.   Window *pMWin = p->pMWin;

  147624.   Vdbe *v = p->pVdbe;

  147625. 

  147626.   if( pMWin->regStartRowid ){

  147627.     windowFullScan(p);

  147628.   }else{

  147629.     Parse *pParse = p->pParse;

  147630.     Window *pWin;

  147631. 

  147632.     for(pWin=pMWin; pWin; pWin=pWin->pNextWin){

  147633.       FuncDef *pFunc = pWin->pFunc;

  147634.       if( pFunc->zName==nth_valueName

  147635.        || pFunc->zName==first_valueName

  147636.       ){

  147637.         int csr = pWin->csrApp;

  147638.         int lbl = sqlite3VdbeMakeLabel(pParse);

  147639.         int tmpReg = sqlite3GetTempReg(pParse);

  147640.         sqlite3VdbeAddOp2(v, OP_Null, 0, pWin->regResult);

  147641.   

  147642.         if( pFunc->zName==nth_valueName ){

  147643.           sqlite3VdbeAddOp3(v, OP_Column,pMWin->iEphCsr,pWin->iArgCol+1,tmpReg);

  147644.           windowCheckValue(pParse, tmpReg, 2);

  147645.         }else{

  147646.           sqlite3VdbeAddOp2(v, OP_Integer, 1, tmpReg);

  147647.         }

  147648.         sqlite3VdbeAddOp3(v, OP_Add, tmpReg, pWin->regApp, tmpReg);

  147649.         sqlite3VdbeAddOp3(v, OP_Gt, pWin->regApp+1, lbl, tmpReg);

  147650.         VdbeCoverageNeverNull(v);

  147651.         sqlite3VdbeAddOp3(v, OP_SeekRowid, csr, 0, tmpReg);

  147652.         VdbeCoverageNeverTaken(v);

  147653.         sqlite3VdbeAddOp3(v, OP_Column, csr, pWin->iArgCol, pWin->regResult);

  147654.         sqlite3VdbeResolveLabel(v, lbl);

  147655.         sqlite3ReleaseTempReg(pParse, tmpReg);

  147656.       }

  147657.       else if( pFunc->zName==leadName || pFunc->zName==lagName ){

  147658.         int nArg = pWin->pOwner->x.pList->nExpr;

  147659.         int csr = pWin->csrApp;

  147660.         int lbl = sqlite3VdbeMakeLabel(pParse);

  147661.         int tmpReg = sqlite3GetTempReg(pParse);

  147662.         int iEph = pMWin->iEphCsr;

  147663.   

  147664.         if( nArg<3 ){

  147665.           sqlite3VdbeAddOp2(v, OP_Null, 0, pWin->regResult);

  147666.         }else{

  147667.           sqlite3VdbeAddOp3(v, OP_Column, iEph,pWin->iArgCol+2,pWin->regResult);

  147668.         }

  147669.         sqlite3VdbeAddOp2(v, OP_Rowid, iEph, tmpReg);

  147670.         if( nArg<2 ){

  147671.           int val = (pFunc->zName==leadName ? 1 : -1);

  147672.           sqlite3VdbeAddOp2(v, OP_AddImm, tmpReg, val);

  147673.         }else{

  147674.           int op = (pFunc->zName==leadName ? OP_Add : OP_Subtract);

  147675.           int tmpReg2 = sqlite3GetTempReg(pParse);

  147676.           sqlite3VdbeAddOp3(v, OP_Column, iEph, pWin->iArgCol+1, tmpReg2);

  147677.           sqlite3VdbeAddOp3(v, op, tmpReg2, tmpReg, tmpReg);

  147678.           sqlite3ReleaseTempReg(pParse, tmpReg2);

  147679.         }

  147680.   

  147681.         sqlite3VdbeAddOp3(v, OP_SeekRowid, csr, lbl, tmpReg);

  147682.         VdbeCoverage(v);

  147683.         sqlite3VdbeAddOp3(v, OP_Column, csr, pWin->iArgCol, pWin->regResult);

  147684.         sqlite3VdbeResolveLabel(v, lbl);

  147685.         sqlite3ReleaseTempReg(pParse, tmpReg);

  147686.       }

  147687.     }

  147688.   }

  147689.   sqlite3VdbeAddOp2(v, OP_Gosub, p->regGosub, p->addrGosub);

  147690. }

  147691. 

  147692. /*

  147693. ** Generate code to set the accumulator register for each window function

  147694. ** in the linked list passed as the second argument to NULL. And perform

  147695. ** any equivalent initialization required by any built-in window functions

  147696. ** in the list.

  147697. */

  147698. static int windowInitAccum(Parse *pParse, Window *pMWin){

  147699.   Vdbe *v = sqlite3GetVdbe(pParse);

  147700.   int regArg;

  147701.   int nArg = 0;

  147702.   Window *pWin;

  147703.   for(pWin=pMWin; pWin; pWin=pWin->pNextWin){

  147704.     FuncDef *pFunc = pWin->pFunc;

  147705.     sqlite3VdbeAddOp2(v, OP_Null, 0, pWin->regAccum);

  147706.     nArg = MAX(nArg, windowArgCount(pWin));

  147707.     if( pMWin->regStartRowid==0 ){

  147708.       if( pFunc->zName==nth_valueName || pFunc->zName==first_valueName ){

  147709.         sqlite3VdbeAddOp2(v, OP_Integer, 0, pWin->regApp);

  147710.         sqlite3VdbeAddOp2(v, OP_Integer, 0, pWin->regApp+1);

  147711.       }

  147712. 

  147713.       if( (pFunc->funcFlags & SQLITE_FUNC_MINMAX) && pWin->csrApp ){

  147714.         assert( pWin->eStart!=TK_UNBOUNDED );

  147715.         sqlite3VdbeAddOp1(v, OP_ResetSorter, pWin->csrApp);

  147716.         sqlite3VdbeAddOp2(v, OP_Integer, 0, pWin->regApp+1);

  147717.       }

  147718.     }

  147719.   }

  147720.   regArg = pParse->nMem+1;

  147721.   pParse->nMem += nArg;

  147722.   return regArg;

  147723. }

  147724. 

  147725. /* 

  147726. ** Return true if the current frame should be cached in the ephemeral table,

  147727. ** even if there are no xInverse() calls required.

  147728. */

  147729. static int windowCacheFrame(Window *pMWin){

  147730.   Window *pWin;

  147731.   if( pMWin->regStartRowid ) return 1;

  147732.   for(pWin=pMWin; pWin; pWin=pWin->pNextWin){

  147733.     FuncDef *pFunc = pWin->pFunc;

  147734.     if( (pFunc->zName==nth_valueName)

  147735.      || (pFunc->zName==first_valueName)

  147736.      || (pFunc->zName==leadName)

  147737.      || (pFunc->zName==lagName)

  147738.     ){

  147739.       return 1;

  147740.     }

  147741.   }

  147742.   return 0;

  147743. }

  147744. 

  147745. /*

  147746. ** regOld and regNew are each the first register in an array of size

  147747. ** pOrderBy->nExpr. This function generates code to compare the two

  147748. ** arrays of registers using the collation sequences and other comparison

  147749. ** parameters specified by pOrderBy. 

  147750. **

  147751. ** If the two arrays are not equal, the contents of regNew is copied to 

  147752. ** regOld and control falls through. Otherwise, if the contents of the arrays

  147753. ** are equal, an OP_Goto is executed. The address of the OP_Goto is returned.

  147754. */

  147755. static void windowIfNewPeer(

  147756.   Parse *pParse,

  147757.   ExprList *pOrderBy,

  147758.   int regNew,                     /* First in array of new values */

  147759.   int regOld,                     /* First in array of old values */

  147760.   int addr                        /* Jump here */

  147761. ){

  147762.   Vdbe *v = sqlite3GetVdbe(pParse);

  147763.   if( pOrderBy ){

  147764.     int nVal = pOrderBy->nExpr;

  147765.     KeyInfo *pKeyInfo = sqlite3KeyInfoFromExprList(pParse, pOrderBy, 0, 0);

  147766.     sqlite3VdbeAddOp3(v, OP_Compare, regOld, regNew, nVal);

  147767.     sqlite3VdbeAppendP4(v, (void*)pKeyInfo, P4_KEYINFO);

  147768.     sqlite3VdbeAddOp3(v, OP_Jump, 

  147769.       sqlite3VdbeCurrentAddr(v)+1, addr, sqlite3VdbeCurrentAddr(v)+1

  147770.     );

  147771.     VdbeCoverageEqNe(v);

  147772.     sqlite3VdbeAddOp3(v, OP_Copy, regNew, regOld, nVal-1);

  147773.   }else{

  147774.     sqlite3VdbeAddOp2(v, OP_Goto, 0, addr);

  147775.   }

  147776. }

  147777. 

  147778. /*

  147779. ** This function is called as part of generating VM programs for RANGE

  147780. ** offset PRECEDING/FOLLOWING frame boundaries. Assuming "ASC" order for

  147781. ** the ORDER BY term in the window, it generates code equivalent to:

  147782. **

  147783. **   if( csr1.peerVal + regVal >= csr2.peerVal ) goto lbl;

  147784. **

  147785. ** A special type of arithmetic is used such that if csr.peerVal is not

  147786. ** a numeric type (real or integer), then the result of the addition is

  147787. ** a copy of csr1.peerVal.

  147788. */

  147789. static void windowCodeRangeTest(

  147790.   WindowCodeArg *p, 

  147791.   int op,                          /* OP_Ge or OP_Gt */

  147792.   int csr1, 

  147793.   int regVal, 

  147794.   int csr2,

  147795.   int lbl

  147796. ){

  147797.   Parse *pParse = p->pParse;

  147798.   Vdbe *v = sqlite3GetVdbe(pParse);

  147799.   int reg1 = sqlite3GetTempReg(pParse);

  147800.   int reg2 = sqlite3GetTempReg(pParse);

  147801.   int arith = OP_Add;

  147802.   int addrGe;

  147803. 

  147804.   int regString = ++pParse->nMem;

  147805. 

  147806.   assert( op==OP_Ge || op==OP_Gt || op==OP_Le );

  147807.   assert( p->pMWin->pOrderBy && p->pMWin->pOrderBy->nExpr==1 );

  147808.   if( p->pMWin->pOrderBy->a[0].sortOrder ){

  147809.     switch( op ){

  147810.       case OP_Ge: op = OP_Le; break;

  147811.       case OP_Gt: op = OP_Lt; break;

  147812.       default: assert( op==OP_Le ); op = OP_Ge; break;

  147813.     }

  147814.     arith = OP_Subtract;

  147815.   }

  147816. 

  147817.   windowReadPeerValues(p, csr1, reg1);

  147818.   windowReadPeerValues(p, csr2, reg2);

  147819. 

  147820.   /* Check if the peer value for csr1 value is a text or blob by comparing

  147821.   ** it to the smallest possible string - ''. If it is, jump over the

  147822.   ** OP_Add or OP_Subtract operation and proceed directly to the comparison. */

  147823.   sqlite3VdbeAddOp4(v, OP_String8, 0, regString, 0, "", P4_STATIC);

  147824.   addrGe = sqlite3VdbeAddOp3(v, OP_Ge, regString, 0, reg1);

  147825.   VdbeCoverage(v);

  147826.   sqlite3VdbeAddOp3(v, arith, regVal, reg1, reg1);

  147827.   sqlite3VdbeJumpHere(v, addrGe);

  147828.   sqlite3VdbeAddOp3(v, op, reg2, lbl, reg1); VdbeCoverage(v);

  147829.   sqlite3VdbeChangeP5(v, SQLITE_NULLEQ);

  147830.   assert( op==OP_Ge || op==OP_Gt || op==OP_Lt || op==OP_Le );

  147831.   testcase(op==OP_Ge); VdbeCoverageIf(v, op==OP_Ge);

  147832.   testcase(op==OP_Lt); VdbeCoverageIf(v, op==OP_Lt);

  147833.   testcase(op==OP_Le); VdbeCoverageIf(v, op==OP_Le);

  147834.   testcase(op==OP_Gt); VdbeCoverageIf(v, op==OP_Gt);

  147835. 

  147836.   sqlite3ReleaseTempReg(pParse, reg1);

  147837.   sqlite3ReleaseTempReg(pParse, reg2);

  147838. }

  147839. 

  147840. /*

  147841. ** Helper function for sqlite3WindowCodeStep(). Each call to this function

  147842. ** generates VM code for a single RETURN_ROW, AGGSTEP or AGGINVERSE 

  147843. ** operation. Refer to the header comment for sqlite3WindowCodeStep() for

  147844. ** details.

  147845. */

  147846. static int windowCodeOp(

  147847.  WindowCodeArg *p,                /* Context object */

  147848.  int op,                          /* WINDOW_RETURN_ROW, AGGSTEP or AGGINVERSE */

  147849.  int regCountdown,                /* Register for OP_IfPos countdown */

  147850.  int jumpOnEof                    /* Jump here if stepped cursor reaches EOF */

  147851. ){

  147852.   int csr, reg;

  147853.   Parse *pParse = p->pParse;

  147854.   Window *pMWin = p->pMWin;

  147855.   int ret = 0;

  147856.   Vdbe *v = p->pVdbe;

  147857.   int addrIf = 0; 

  147858.   int addrContinue = 0;

  147859.   int addrGoto = 0;

  147860.   int bPeer = (pMWin->eFrmType!=TK_ROWS);

  147861. 

  147862.   int lblDone = sqlite3VdbeMakeLabel(pParse);

  147863.   int addrNextRange = 0;

  147864. 

  147865.   /* Special case - WINDOW_AGGINVERSE is always a no-op if the frame

  147866.   ** starts with UNBOUNDED PRECEDING. */

  147867.   if( op==WINDOW_AGGINVERSE && pMWin->eStart==TK_UNBOUNDED ){

  147868.     assert( regCountdown==0 && jumpOnEof==0 );

  147869.     return 0;

  147870.   }

  147871. 

  147872.   if( regCountdown>0 ){

  147873.     if( pMWin->eFrmType==TK_RANGE ){

  147874.       addrNextRange = sqlite3VdbeCurrentAddr(v);

  147875.       assert( op==WINDOW_AGGINVERSE || op==WINDOW_AGGSTEP );

  147876.       if( op==WINDOW_AGGINVERSE ){

  147877.         if( pMWin->eStart==TK_FOLLOWING ){

  147878.           windowCodeRangeTest(

  147879.               p, OP_Le, p->current.csr, regCountdown, p->start.csr, lblDone

  147880.           );

  147881.         }else{

  147882.           windowCodeRangeTest(

  147883.               p, OP_Ge, p->start.csr, regCountdown, p->current.csr, lblDone

  147884.           );

  147885.         }

  147886.       }else{

  147887.         windowCodeRangeTest(

  147888.             p, OP_Gt, p->end.csr, regCountdown, p->current.csr, lblDone

  147889.         );

  147890.       }

  147891.     }else{

  147892.       addrIf = sqlite3VdbeAddOp3(v, OP_IfPos, regCountdown, 0, 1);

  147893.       VdbeCoverage(v);

  147894.     }

  147895.   }

  147896. 

  147897.   if( op==WINDOW_RETURN_ROW && pMWin->regStartRowid==0 ){

  147898.     windowAggFinal(p, 0);

  147899.   }

  147900.   addrContinue = sqlite3VdbeCurrentAddr(v);

  147901.   switch( op ){

  147902.     case WINDOW_RETURN_ROW:

  147903.       csr = p->current.csr;

  147904.       reg = p->current.reg;

  147905.       windowReturnOneRow(p);

  147906.       break;

  147907. 

  147908.     case WINDOW_AGGINVERSE:

  147909.       csr = p->start.csr;

  147910.       reg = p->start.reg;

  147911.       if( pMWin->regStartRowid ){

  147912.         assert( pMWin->regEndRowid );

  147913.         sqlite3VdbeAddOp2(v, OP_AddImm, pMWin->regStartRowid, 1);

  147914.       }else{

  147915.         windowAggStep(pParse, pMWin, csr, 1, p->regArg);

  147916.       }

  147917.       break;

  147918. 

  147919.     default:

  147920.       assert( op==WINDOW_AGGSTEP );

  147921.       csr = p->end.csr;

  147922.       reg = p->end.reg;

  147923.       if( pMWin->regStartRowid ){

  147924.         assert( pMWin->regEndRowid );

  147925.         sqlite3VdbeAddOp2(v, OP_AddImm, pMWin->regEndRowid, 1);

  147926.       }else{

  147927.         windowAggStep(pParse, pMWin, csr, 0, p->regArg);

  147928.       }

  147929.       break;

  147930.   }

  147931. 

  147932.   if( op==p->eDelete ){

  147933.     sqlite3VdbeAddOp1(v, OP_Delete, csr);

  147934.     sqlite3VdbeChangeP5(v, OPFLAG_SAVEPOSITION);

  147935.   }

  147936. 

  147937.   if( jumpOnEof ){

  147938.     sqlite3VdbeAddOp2(v, OP_Next, csr, sqlite3VdbeCurrentAddr(v)+2);

  147939.     VdbeCoverage(v);

  147940.     ret = sqlite3VdbeAddOp0(v, OP_Goto);

  147941.   }else{

  147942.     sqlite3VdbeAddOp2(v, OP_Next, csr, sqlite3VdbeCurrentAddr(v)+1+bPeer);

  147943.     VdbeCoverage(v);

  147944.     if( bPeer ){

  147945.       addrGoto = sqlite3VdbeAddOp0(v, OP_Goto);

  147946.     }

  147947.   }

  147948. 

  147949.   if( bPeer ){

  147950.     int nReg = (pMWin->pOrderBy ? pMWin->pOrderBy->nExpr : 0);

  147951.     int regTmp = (nReg ? sqlite3GetTempRange(pParse, nReg) : 0);

  147952.     windowReadPeerValues(p, csr, regTmp);

  147953.     windowIfNewPeer(pParse, pMWin->pOrderBy, regTmp, reg, addrContinue);

  147954.     sqlite3ReleaseTempRange(pParse, regTmp, nReg);

  147955.   }

  147956. 

  147957.   if( addrNextRange ){

  147958.     sqlite3VdbeAddOp2(v, OP_Goto, 0, addrNextRange);

  147959.   }

  147960.   sqlite3VdbeResolveLabel(v, lblDone);

  147961.   if( addrGoto ) sqlite3VdbeJumpHere(v, addrGoto);

  147962.   if( addrIf ) sqlite3VdbeJumpHere(v, addrIf);

  147963.   return ret;

  147964. }

  147965. 

  147966. 

  147967. /*

  147968. ** Allocate and return a duplicate of the Window object indicated by the

  147969. ** third argument. Set the Window.pOwner field of the new object to

  147970. ** pOwner.

  147971. */

  147972. SQLITE_PRIVATE Window *sqlite3WindowDup(sqlite3 *db, Expr *pOwner, Window *p){

  147973.   Window *pNew = 0;

  147974.   if( ALWAYS(p) ){

  147975.     pNew = sqlite3DbMallocZero(db, sizeof(Window));

  147976.     if( pNew ){

  147977.       pNew->zName = sqlite3DbStrDup(db, p->zName);

  147978.       pNew->pFilter = sqlite3ExprDup(db, p->pFilter, 0);

  147979.       pNew->pFunc = p->pFunc;

  147980.       pNew->pPartition = sqlite3ExprListDup(db, p->pPartition, 0);

  147981.       pNew->pOrderBy = sqlite3ExprListDup(db, p->pOrderBy, 0);

  147982.       pNew->eFrmType = p->eFrmType;

  147983.       pNew->eEnd = p->eEnd;

  147984.       pNew->eStart = p->eStart;

  147985.       pNew->eExclude = p->eExclude;

  147986.       pNew->pStart = sqlite3ExprDup(db, p->pStart, 0);

  147987.       pNew->pEnd = sqlite3ExprDup(db, p->pEnd, 0);

  147988.       pNew->pOwner = pOwner;

  147989.     }

  147990.   }

  147991.   return pNew;

  147992. }

  147993. 

  147994. /*

  147995. ** Return a copy of the linked list of Window objects passed as the

  147996. ** second argument.

  147997. */

  147998. SQLITE_PRIVATE Window *sqlite3WindowListDup(sqlite3 *db, Window *p){

  147999.   Window *pWin;

  148000.   Window *pRet = 0;

  148001.   Window **pp = &pRet;

  148002. 

  148003.   for(pWin=p; pWin; pWin=pWin->pNextWin){

  148004.     *pp = sqlite3WindowDup(db, 0, pWin);

  148005.     if( *pp==0 ) break;

  148006.     pp = &((*pp)->pNextWin);

  148007.   }

  148008. 

  148009.   return pRet;

  148010. }

  148011. 

  148012. /*

  148013. ** Return true if it can be determined at compile time that expression 

  148014. ** pExpr evaluates to a value that, when cast to an integer, is greater 

  148015. ** than zero. False otherwise.

  148016. **

  148017. ** If an OOM error occurs, this function sets the Parse.db.mallocFailed 

  148018. ** flag and returns zero.

  148019. */

  148020. static int windowExprGtZero(Parse *pParse, Expr *pExpr){

  148021.   int ret = 0;

  148022.   sqlite3 *db = pParse->db;

  148023.   sqlite3_value *pVal = 0;

  148024.   sqlite3ValueFromExpr(db, pExpr, db->enc, SQLITE_AFF_NUMERIC, &pVal);

  148025.   if( pVal && sqlite3_value_int(pVal)>0 ){

  148026.     ret = 1;

  148027.   }

  148028.   sqlite3ValueFree(pVal);

  148029.   return ret;

  148030. }

  148031. 

  148032. /*

  148033. ** sqlite3WhereBegin() has already been called for the SELECT statement 

  148034. ** passed as the second argument when this function is invoked. It generates

  148035. ** code to populate the Window.regResult register for each window function 

  148036. ** and invoke the sub-routine at instruction addrGosub once for each row.

  148037. ** sqlite3WhereEnd() is always called before returning. 

  148038. **

  148039. ** This function handles several different types of window frames, which

  148040. ** require slightly different processing. The following pseudo code is

  148041. ** used to implement window frames of the form:

  148042. **

  148043. **   ROWS BETWEEN <expr1> PRECEDING AND <expr2> FOLLOWING

  148044. **

  148045. ** Other window frame types use variants of the following:

  148046. **

  148047. **     ... loop started by sqlite3WhereBegin() ...

  148048. **       if( new partition ){

  148049. **         Gosub flush

  148050. **       }

  148051. **       Insert new row into eph table.

  148052. **       

  148053. **       if( first row of partition ){

  148054. **         // Rewind three cursors, all open on the eph table.

  148055. **         Rewind(csrEnd);

  148056. **         Rewind(csrStart);

  148057. **         Rewind(csrCurrent);

  148058. **       

  148059. **         regEnd = <expr2>          // FOLLOWING expression

  148060. **         regStart = <expr1>        // PRECEDING expression

  148061. **       }else{

  148062. **         // First time this branch is taken, the eph table contains two 

  148063. **         // rows. The first row in the partition, which all three cursors

  148064. **         // currently point to, and the following row.

  148065. **         AGGSTEP

  148066. **         if( (regEnd--)<=0 ){

  148067. **           RETURN_ROW

  148068. **           if( (regStart--)<=0 ){

  148069. **             AGGINVERSE

  148070. **           }

  148071. **         }

  148072. **       }

  148073. **     }

  148074. **     flush:

  148075. **       AGGSTEP

  148076. **       while( 1 ){

  148077. **         RETURN ROW

  148078. **         if( csrCurrent is EOF ) break;

  148079. **         if( (regStart--)<=0 ){

  148080. **           AggInverse(csrStart)

  148081. **           Next(csrStart)

  148082. **         }

  148083. **       }

  148084. **

  148085. ** The pseudo-code above uses the following shorthand:

  148086. **

  148087. **   AGGSTEP:    invoke the aggregate xStep() function for each window function

  148088. **               with arguments read from the current row of cursor csrEnd, then

  148089. **               step cursor csrEnd forward one row (i.e. sqlite3BtreeNext()).

  148090. **

  148091. **   RETURN_ROW: return a row to the caller based on the contents of the 

  148092. **               current row of csrCurrent and the current state of all 

  148093. **               aggregates. Then step cursor csrCurrent forward one row.

  148094. **

  148095. **   AGGINVERSE: invoke the aggregate xInverse() function for each window 

  148096. **               functions with arguments read from the current row of cursor

  148097. **               csrStart. Then step csrStart forward one row.

  148098. **

  148099. ** There are two other ROWS window frames that are handled significantly

  148100. ** differently from the above - "BETWEEN <expr> PRECEDING AND <expr> PRECEDING"

  148101. ** and "BETWEEN <expr> FOLLOWING AND <expr> FOLLOWING". These are special 

  148102. ** cases because they change the order in which the three cursors (csrStart,

  148103. ** csrCurrent and csrEnd) iterate through the ephemeral table. Cases that

  148104. ** use UNBOUNDED or CURRENT ROW are much simpler variations on one of these

  148105. ** three.

  148106. **

  148107. **   ROWS BETWEEN <expr1> PRECEDING AND <expr2> PRECEDING

  148108. **

  148109. **     ... loop started by sqlite3WhereBegin() ...

  148110. **       if( new partition ){

  148111. **         Gosub flush

  148112. **       }

  148113. **       Insert new row into eph table.

  148114. **       if( first row of partition ){

  148115. **         Rewind(csrEnd) ; Rewind(csrStart) ; Rewind(csrCurrent)

  148116. **         regEnd = <expr2>

  148117. **         regStart = <expr1>

  148118. **       }else{

  148119. **         if( (regEnd--)<=0 ){

  148120. **           AGGSTEP

  148121. **         }

  148122. **         RETURN_ROW

  148123. **         if( (regStart--)<=0 ){

  148124. **           AGGINVERSE

  148125. **         }

  148126. **       }

  148127. **     }

  148128. **     flush:

  148129. **       if( (regEnd--)<=0 ){

  148130. **         AGGSTEP

  148131. **       }

  148132. **       RETURN_ROW

  148133. **

  148134. **

  148135. **   ROWS BETWEEN <expr1> FOLLOWING AND <expr2> FOLLOWING

  148136. **

  148137. **     ... loop started by sqlite3WhereBegin() ...

  148138. **     if( new partition ){

  148139. **       Gosub flush

  148140. **     }

  148141. **     Insert new row into eph table.

  148142. **     if( first row of partition ){

  148143. **       Rewind(csrEnd) ; Rewind(csrStart) ; Rewind(csrCurrent)

  148144. **       regEnd = <expr2>

  148145. **       regStart = regEnd - <expr1>

  148146. **     }else{

  148147. **       AGGSTEP

  148148. **       if( (regEnd--)<=0 ){

  148149. **         RETURN_ROW

  148150. **       }

  148151. **       if( (regStart--)<=0 ){

  148152. **         AGGINVERSE

  148153. **       }

  148154. **     }

  148155. **   }

  148156. **   flush:

  148157. **     AGGSTEP

  148158. **     while( 1 ){

  148159. **       if( (regEnd--)<=0 ){

  148160. **         RETURN_ROW

  148161. **         if( eof ) break;

  148162. **       }

  148163. **       if( (regStart--)<=0 ){

  148164. **         AGGINVERSE

  148165. **         if( eof ) break

  148166. **       }

  148167. **     }

  148168. **     while( !eof csrCurrent ){

  148169. **       RETURN_ROW

  148170. **     }

  148171. **

  148172. ** For the most part, the patterns above are adapted to support UNBOUNDED by

  148173. ** assuming that it is equivalent to "infinity PRECEDING/FOLLOWING" and

  148174. ** CURRENT ROW by assuming that it is equivilent to "0 PRECEDING/FOLLOWING".

  148175. ** This is optimized of course - branches that will never be taken and

  148176. ** conditions that are always true are omitted from the VM code. The only

  148177. ** exceptional case is:

  148178. **

  148179. **   ROWS BETWEEN <expr1> FOLLOWING AND UNBOUNDED FOLLOWING

  148180. **

  148181. **     ... loop started by sqlite3WhereBegin() ...

  148182. **     if( new partition ){

  148183. **       Gosub flush

  148184. **     }

  148185. **     Insert new row into eph table.

  148186. **     if( first row of partition ){

  148187. **       Rewind(csrEnd) ; Rewind(csrStart) ; Rewind(csrCurrent)

  148188. **       regStart = <expr1>

  148189. **     }else{

  148190. **       AGGSTEP

  148191. **     }

  148192. **   }

  148193. **   flush:

  148194. **     AGGSTEP

  148195. **     while( 1 ){

  148196. **       if( (regStart--)<=0 ){

  148197. **         AGGINVERSE

  148198. **         if( eof ) break

  148199. **       }

  148200. **       RETURN_ROW

  148201. **     }

  148202. **     while( !eof csrCurrent ){

  148203. **       RETURN_ROW

  148204. **     }

  148205. **

  148206. ** Also requiring special handling are the cases:

  148207. **

  148208. **   ROWS BETWEEN <expr1> PRECEDING AND <expr2> PRECEDING

  148209. **   ROWS BETWEEN <expr1> FOLLOWING AND <expr2> FOLLOWING

  148210. **

  148211. ** when (expr1 < expr2). This is detected at runtime, not by this function.

  148212. ** To handle this case, the pseudo-code programs depicted above are modified

  148213. ** slightly to be:

  148214. **

  148215. **     ... loop started by sqlite3WhereBegin() ...

  148216. **     if( new partition ){

  148217. **       Gosub flush

  148218. **     }

  148219. **     Insert new row into eph table.

  148220. **     if( first row of partition ){

  148221. **       Rewind(csrEnd) ; Rewind(csrStart) ; Rewind(csrCurrent)

  148222. **       regEnd = <expr2>

  148223. **       regStart = <expr1>

  148224. **       if( regEnd < regStart ){

  148225. **         RETURN_ROW

  148226. **         delete eph table contents

  148227. **         continue

  148228. **       }

  148229. **     ...

  148230. **

  148231. ** The new "continue" statement in the above jumps to the next iteration

  148232. ** of the outer loop - the one started by sqlite3WhereBegin().

  148233. **

  148234. ** The various GROUPS cases are implemented using the same patterns as

  148235. ** ROWS. The VM code is modified slightly so that:

  148236. **

  148237. **   1. The else branch in the main loop is only taken if the row just

  148238. **      added to the ephemeral table is the start of a new group. In

  148239. **      other words, it becomes:

  148240. **

  148241. **         ... loop started by sqlite3WhereBegin() ...

  148242. **         if( new partition ){

  148243. **           Gosub flush

  148244. **         }

  148245. **         Insert new row into eph table.

  148246. **         if( first row of partition ){

  148247. **           Rewind(csrEnd) ; Rewind(csrStart) ; Rewind(csrCurrent)

  148248. **           regEnd = <expr2>

  148249. **           regStart = <expr1>

  148250. **         }else if( new group ){

  148251. **           ... 

  148252. **         }

  148253. **       }

  148254. **

  148255. **   2. Instead of processing a single row, each RETURN_ROW, AGGSTEP or 

  148256. **      AGGINVERSE step processes the current row of the relevant cursor and

  148257. **      all subsequent rows belonging to the same group.

  148258. **

  148259. ** RANGE window frames are a little different again. As for GROUPS, the 

  148260. ** main loop runs once per group only. And RETURN_ROW, AGGSTEP and AGGINVERSE

  148261. ** deal in groups instead of rows. As for ROWS and GROUPS, there are three

  148262. ** basic cases:

  148263. **

  148264. **   RANGE BETWEEN <expr1> PRECEDING AND <expr2> FOLLOWING

  148265. **

  148266. **     ... loop started by sqlite3WhereBegin() ...

  148267. **       if( new partition ){

  148268. **         Gosub flush

  148269. **       }

  148270. **       Insert new row into eph table.

  148271. **       if( first row of partition ){

  148272. **         Rewind(csrEnd) ; Rewind(csrStart) ; Rewind(csrCurrent)

  148273. **         regEnd = <expr2>

  148274. **         regStart = <expr1>

  148275. **       }else{

  148276. **         AGGSTEP

  148277. **         while( (csrCurrent.key + regEnd) < csrEnd.key ){

  148278. **           RETURN_ROW

  148279. **           while( csrStart.key + regStart) < csrCurrent.key ){

  148280. **             AGGINVERSE

  148281. **           }

  148282. **         }

  148283. **       }

  148284. **     }

  148285. **     flush:

  148286. **       AGGSTEP

  148287. **       while( 1 ){

  148288. **         RETURN ROW

  148289. **         if( csrCurrent is EOF ) break;

  148290. **           while( csrStart.key + regStart) < csrCurrent.key ){

  148291. **             AGGINVERSE

  148292. **           }

  148293. **         }

  148294. **       }

  148295. **

  148296. ** In the above notation, "csr.key" means the current value of the ORDER BY 

  148297. ** expression (there is only ever 1 for a RANGE that uses an <expr> FOLLOWING

  148298. ** or <expr PRECEDING) read from cursor csr.

  148299. **

  148300. **   RANGE BETWEEN <expr1> PRECEDING AND <expr2> PRECEDING

  148301. **

  148302. **     ... loop started by sqlite3WhereBegin() ...

  148303. **       if( new partition ){

  148304. **         Gosub flush

  148305. **       }

  148306. **       Insert new row into eph table.

  148307. **       if( first row of partition ){

  148308. **         Rewind(csrEnd) ; Rewind(csrStart) ; Rewind(csrCurrent)

  148309. **         regEnd = <expr2>

  148310. **         regStart = <expr1>

  148311. **       }else{

  148312. **         if( (csrEnd.key + regEnd) <= csrCurrent.key ){

  148313. **           AGGSTEP

  148314. **         }

  148315. **         while( (csrStart.key + regStart) < csrCurrent.key ){

  148316. **           AGGINVERSE

  148317. **         }

  148318. **         RETURN_ROW

  148319. **       }

  148320. **     }

  148321. **     flush:

  148322. **       while( (csrEnd.key + regEnd) <= csrCurrent.key ){

  148323. **         AGGSTEP

  148324. **       }

  148325. **       while( (csrStart.key + regStart) < csrCurrent.key ){

  148326. **         AGGINVERSE

  148327. **       }

  148328. **       RETURN_ROW

  148329. **

  148330. **   RANGE BETWEEN <expr1> FOLLOWING AND <expr2> FOLLOWING

  148331. **

  148332. **     ... loop started by sqlite3WhereBegin() ...

  148333. **       if( new partition ){

  148334. **         Gosub flush

  148335. **       }

  148336. **       Insert new row into eph table.

  148337. **       if( first row of partition ){

  148338. **         Rewind(csrEnd) ; Rewind(csrStart) ; Rewind(csrCurrent)

  148339. **         regEnd = <expr2>

  148340. **         regStart = <expr1>

  148341. **       }else{

  148342. **         AGGSTEP

  148343. **         while( (csrCurrent.key + regEnd) < csrEnd.key ){

  148344. **           while( (csrCurrent.key + regStart) > csrStart.key ){

  148345. **             AGGINVERSE

  148346. **           }

  148347. **           RETURN_ROW

  148348. **         }

  148349. **       }

  148350. **     }

  148351. **     flush:

  148352. **       AGGSTEP

  148353. **       while( 1 ){

  148354. **         while( (csrCurrent.key + regStart) > csrStart.key ){

  148355. **           AGGINVERSE

  148356. **           if( eof ) break "while( 1 )" loop.

  148357. **         }

  148358. **         RETURN_ROW

  148359. **       }

  148360. **       while( !eof csrCurrent ){

  148361. **         RETURN_ROW

  148362. **       }

  148363. **

  148364. ** The text above leaves out many details. Refer to the code and comments

  148365. ** below for a more complete picture.

  148366. */

  148367. SQLITE_PRIVATE void sqlite3WindowCodeStep(

  148368.   Parse *pParse,                  /* Parse context */

  148369.   Select *p,                      /* Rewritten SELECT statement */

  148370.   WhereInfo *pWInfo,              /* Context returned by sqlite3WhereBegin() */

  148371.   int regGosub,                   /* Register for OP_Gosub */

  148372.   int addrGosub                   /* OP_Gosub here to return each row */

  148373. ){

  148374.   Window *pMWin = p->pWin;

  148375.   ExprList *pOrderBy = pMWin->pOrderBy;

  148376.   Vdbe *v = sqlite3GetVdbe(pParse);

  148377.   int csrWrite;                   /* Cursor used to write to eph. table */

  148378.   int csrInput = p->pSrc->a[0].iCursor;     /* Cursor of sub-select */

  148379.   int nInput = p->pSrc->a[0].pTab->nCol;    /* Number of cols returned by sub */

  148380.   int iInput;                               /* To iterate through sub cols */

  148381.   int addrNe;                     /* Address of OP_Ne */

  148382.   int addrGosubFlush = 0;         /* Address of OP_Gosub to flush: */

  148383.   int addrInteger = 0;            /* Address of OP_Integer */

  148384.   int addrEmpty;                  /* Address of OP_Rewind in flush: */

  148385.   int regStart = 0;               /* Value of <expr> PRECEDING */

  148386.   int regEnd = 0;                 /* Value of <expr> FOLLOWING */

  148387.   int regNew;                     /* Array of registers holding new input row */

  148388.   int regRecord;                  /* regNew array in record form */

  148389.   int regRowid;                   /* Rowid for regRecord in eph table */

  148390.   int regNewPeer = 0;             /* Peer values for new row (part of regNew) */

  148391.   int regPeer = 0;                /* Peer values for current row */

  148392.   int regFlushPart = 0;           /* Register for "Gosub flush_partition" */

  148393.   WindowCodeArg s;                /* Context object for sub-routines */

  148394.   int lblWhereEnd;                /* Label just before sqlite3WhereEnd() code */

  148395. 

  148396.   assert( pMWin->eStart==TK_PRECEDING || pMWin->eStart==TK_CURRENT 

  148397.        || pMWin->eStart==TK_FOLLOWING || pMWin->eStart==TK_UNBOUNDED 

  148398.   );

  148399.   assert( pMWin->eEnd==TK_FOLLOWING || pMWin->eEnd==TK_CURRENT 

  148400.        || pMWin->eEnd==TK_UNBOUNDED || pMWin->eEnd==TK_PRECEDING 

  148401.   );

  148402.   assert( pMWin->eExclude==0 || pMWin->eExclude==TK_CURRENT

  148403.        || pMWin->eExclude==TK_GROUP || pMWin->eExclude==TK_TIES

  148404.        || pMWin->eExclude==TK_NO

  148405.   );

  148406. 

  148407.   lblWhereEnd = sqlite3VdbeMakeLabel(pParse);

  148408. 

  148409.   /* Fill in the context object */

  148410.   memset(&s, 0, sizeof(WindowCodeArg));

  148411.   s.pParse = pParse;

  148412.   s.pMWin = pMWin;

  148413.   s.pVdbe = v;

  148414.   s.regGosub = regGosub;

  148415.   s.addrGosub = addrGosub;

  148416.   s.current.csr = pMWin->iEphCsr;

  148417.   csrWrite = s.current.csr+1;

  148418.   s.start.csr = s.current.csr+2;

  148419.   s.end.csr = s.current.csr+3;

  148420. 

  148421.   /* Figure out when rows may be deleted from the ephemeral table. There

  148422.   ** are four options - they may never be deleted (eDelete==0), they may 

  148423.   ** be deleted as soon as they are no longer part of the window frame

  148424.   ** (eDelete==WINDOW_AGGINVERSE), they may be deleted as after the row 

  148425.   ** has been returned to the caller (WINDOW_RETURN_ROW), or they may

  148426.   ** be deleted after they enter the frame (WINDOW_AGGSTEP). */

  148427.   switch( pMWin->eStart ){

  148428.     case TK_FOLLOWING:

  148429.       if( pMWin->eFrmType!=TK_RANGE

  148430.        && windowExprGtZero(pParse, pMWin->pStart)

  148431.       ){

  148432.         s.eDelete = WINDOW_RETURN_ROW;

  148433.       }

  148434.       break;

  148435.     case TK_UNBOUNDED:

  148436.       if( windowCacheFrame(pMWin)==0 ){

  148437.         if( pMWin->eEnd==TK_PRECEDING ){

  148438.           if( pMWin->eFrmType!=TK_RANGE

  148439.            && windowExprGtZero(pParse, pMWin->pEnd)

  148440.           ){

  148441.             s.eDelete = WINDOW_AGGSTEP;

  148442.           }

  148443.         }else{

  148444.           s.eDelete = WINDOW_RETURN_ROW;

  148445.         }

  148446.       }

  148447.       break;

  148448.     default:

  148449.       s.eDelete = WINDOW_AGGINVERSE;

  148450.       break;

  148451.   }

  148452. 

  148453.   /* Allocate registers for the array of values from the sub-query, the

  148454.   ** samve values in record form, and the rowid used to insert said record

  148455.   ** into the ephemeral table.  */

  148456.   regNew = pParse->nMem+1;

  148457.   pParse->nMem += nInput;

  148458.   regRecord = ++pParse->nMem;

  148459.   regRowid = ++pParse->nMem;

  148460. 

  148461.   /* If the window frame contains an "<expr> PRECEDING" or "<expr> FOLLOWING"

  148462.   ** clause, allocate registers to store the results of evaluating each

  148463.   ** <expr>.  */

  148464.   if( pMWin->eStart==TK_PRECEDING || pMWin->eStart==TK_FOLLOWING ){

  148465.     regStart = ++pParse->nMem;

  148466.   }

  148467.   if( pMWin->eEnd==TK_PRECEDING || pMWin->eEnd==TK_FOLLOWING ){

  148468.     regEnd = ++pParse->nMem;

  148469.   }

  148470. 

  148471.   /* If this is not a "ROWS BETWEEN ..." frame, then allocate arrays of

  148472.   ** registers to store copies of the ORDER BY expressions (peer values) 

  148473.   ** for the main loop, and for each cursor (start, current and end). */

  148474.   if( pMWin->eFrmType!=TK_ROWS ){

  148475.     int nPeer = (pOrderBy ? pOrderBy->nExpr : 0);

  148476.     regNewPeer = regNew + pMWin->nBufferCol;

  148477.     if( pMWin->pPartition ) regNewPeer += pMWin->pPartition->nExpr;

  148478.     regPeer = pParse->nMem+1;       pParse->nMem += nPeer;

  148479.     s.start.reg = pParse->nMem+1;   pParse->nMem += nPeer;

  148480.     s.current.reg = pParse->nMem+1; pParse->nMem += nPeer;

  148481.     s.end.reg = pParse->nMem+1;     pParse->nMem += nPeer;

  148482.   }

  148483. 

  148484.   /* Load the column values for the row returned by the sub-select

  148485.   ** into an array of registers starting at regNew. Assemble them into

  148486.   ** a record in register regRecord. */

  148487.   for(iInput=0; iInput<nInput; iInput++){

  148488.     sqlite3VdbeAddOp3(v, OP_Column, csrInput, iInput, regNew+iInput);

  148489.   }

  148490.   sqlite3VdbeAddOp3(v, OP_MakeRecord, regNew, nInput, regRecord);

  148491. 

  148492.   /* An input row has just been read into an array of registers starting

  148493.   ** at regNew. If the window has a PARTITION clause, this block generates 

  148494.   ** VM code to check if the input row is the start of a new partition.

  148495.   ** If so, it does an OP_Gosub to an address to be filled in later. The

  148496.   ** address of the OP_Gosub is stored in local variable addrGosubFlush. */

  148497.   if( pMWin->pPartition ){

  148498.     int addr;

  148499.     ExprList *pPart = pMWin->pPartition;

  148500.     int nPart = pPart->nExpr;

  148501.     int regNewPart = regNew + pMWin->nBufferCol;

  148502.     KeyInfo *pKeyInfo = sqlite3KeyInfoFromExprList(pParse, pPart, 0, 0);

  148503. 

  148504.     regFlushPart = ++pParse->nMem;

  148505.     addr = sqlite3VdbeAddOp3(v, OP_Compare, regNewPart, pMWin->regPart, nPart);

  148506.     sqlite3VdbeAppendP4(v, (void*)pKeyInfo, P4_KEYINFO);

  148507.     sqlite3VdbeAddOp3(v, OP_Jump, addr+2, addr+4, addr+2);

  148508.     VdbeCoverageEqNe(v);

  148509.     addrGosubFlush = sqlite3VdbeAddOp1(v, OP_Gosub, regFlushPart);

  148510.     VdbeComment((v, "call flush_partition"));

  148511.     sqlite3VdbeAddOp3(v, OP_Copy, regNewPart, pMWin->regPart, nPart-1);

  148512.   }

  148513. 

  148514.   /* Insert the new row into the ephemeral table */

  148515.   sqlite3VdbeAddOp2(v, OP_NewRowid, csrWrite, regRowid);

  148516.   sqlite3VdbeAddOp3(v, OP_Insert, csrWrite, regRecord, regRowid);

  148517.   addrNe = sqlite3VdbeAddOp3(v, OP_Ne, pMWin->regOne, 0, regRowid);

  148518.   VdbeCoverageNeverNull(v);

  148519. 

  148520.   /* This block is run for the first row of each partition */

  148521.   s.regArg = windowInitAccum(pParse, pMWin);

  148522. 

  148523.   if( regStart ){

  148524.     sqlite3ExprCode(pParse, pMWin->pStart, regStart);

  148525.     windowCheckValue(pParse, regStart, 0 + (pMWin->eFrmType==TK_RANGE ? 3 : 0));

  148526.   }

  148527.   if( regEnd ){

  148528.     sqlite3ExprCode(pParse, pMWin->pEnd, regEnd);

  148529.     windowCheckValue(pParse, regEnd, 1 + (pMWin->eFrmType==TK_RANGE ? 3 : 0));

  148530.   }

  148531. 

  148532.   if( pMWin->eStart==pMWin->eEnd && regStart ){

  148533.     int op = ((pMWin->eStart==TK_FOLLOWING) ? OP_Ge : OP_Le);

  148534.     int addrGe = sqlite3VdbeAddOp3(v, op, regStart, 0, regEnd);

  148535.     VdbeCoverageNeverNullIf(v, op==OP_Ge); /* NeverNull because bound <expr> */

  148536.     VdbeCoverageNeverNullIf(v, op==OP_Le); /*   values previously checked */

  148537.     windowAggFinal(&s, 0);

  148538.     sqlite3VdbeAddOp2(v, OP_Rewind, s.current.csr, 1);

  148539.     VdbeCoverageNeverTaken(v);

  148540.     windowReturnOneRow(&s);

  148541.     sqlite3VdbeAddOp1(v, OP_ResetSorter, s.current.csr);

  148542.     sqlite3VdbeAddOp2(v, OP_Goto, 0, lblWhereEnd);

  148543.     sqlite3VdbeJumpHere(v, addrGe);

  148544.   }

  148545.   if( pMWin->eStart==TK_FOLLOWING && pMWin->eFrmType!=TK_RANGE && regEnd ){

  148546.     assert( pMWin->eEnd==TK_FOLLOWING );

  148547.     sqlite3VdbeAddOp3(v, OP_Subtract, regStart, regEnd, regStart);

  148548.   }

  148549. 

  148550.   if( pMWin->eStart!=TK_UNBOUNDED ){

  148551.     sqlite3VdbeAddOp2(v, OP_Rewind, s.start.csr, 1);

  148552.     VdbeCoverageNeverTaken(v);

  148553.   }

  148554.   sqlite3VdbeAddOp2(v, OP_Rewind, s.current.csr, 1);

  148555.   VdbeCoverageNeverTaken(v);

  148556.   sqlite3VdbeAddOp2(v, OP_Rewind, s.end.csr, 1);

  148557.   VdbeCoverageNeverTaken(v);

  148558.   if( regPeer && pOrderBy ){

  148559.     sqlite3VdbeAddOp3(v, OP_Copy, regNewPeer, regPeer, pOrderBy->nExpr-1);

  148560.     sqlite3VdbeAddOp3(v, OP_Copy, regPeer, s.start.reg, pOrderBy->nExpr-1);

  148561.     sqlite3VdbeAddOp3(v, OP_Copy, regPeer, s.current.reg, pOrderBy->nExpr-1);

  148562.     sqlite3VdbeAddOp3(v, OP_Copy, regPeer, s.end.reg, pOrderBy->nExpr-1);

  148563.   }

  148564. 

  148565.   sqlite3VdbeAddOp2(v, OP_Goto, 0, lblWhereEnd);

  148566. 

  148567.   sqlite3VdbeJumpHere(v, addrNe);

  148568. 

  148569.   /* Beginning of the block executed for the second and subsequent rows. */

  148570.   if( regPeer ){

  148571.     windowIfNewPeer(pParse, pOrderBy, regNewPeer, regPeer, lblWhereEnd);

  148572.   }

  148573.   if( pMWin->eStart==TK_FOLLOWING ){

  148574.     windowCodeOp(&s, WINDOW_AGGSTEP, 0, 0);

  148575.     if( pMWin->eEnd!=TK_UNBOUNDED ){

  148576.       if( pMWin->eFrmType==TK_RANGE ){

  148577.         int lbl = sqlite3VdbeMakeLabel(pParse);

  148578.         int addrNext = sqlite3VdbeCurrentAddr(v);

  148579.         windowCodeRangeTest(&s, OP_Ge, s.current.csr, regEnd, s.end.csr, lbl);

  148580.         windowCodeOp(&s, WINDOW_AGGINVERSE, regStart, 0);

  148581.         windowCodeOp(&s, WINDOW_RETURN_ROW, 0, 0);

  148582.         sqlite3VdbeAddOp2(v, OP_Goto, 0, addrNext);

  148583.         sqlite3VdbeResolveLabel(v, lbl);

  148584.       }else{

  148585.         windowCodeOp(&s, WINDOW_RETURN_ROW, regEnd, 0);

  148586.         windowCodeOp(&s, WINDOW_AGGINVERSE, regStart, 0);

  148587.       }

  148588.     }

  148589.   }else

  148590.   if( pMWin->eEnd==TK_PRECEDING ){

  148591.     int bRPS = (pMWin->eStart==TK_PRECEDING && pMWin->eFrmType==TK_RANGE);

  148592.     windowCodeOp(&s, WINDOW_AGGSTEP, regEnd, 0);

  148593.     if( bRPS ) windowCodeOp(&s, WINDOW_AGGINVERSE, regStart, 0);

  148594.     windowCodeOp(&s, WINDOW_RETURN_ROW, 0, 0);

  148595.     if( !bRPS ) windowCodeOp(&s, WINDOW_AGGINVERSE, regStart, 0);

  148596.   }else{

  148597.     int addr = 0;

  148598.     windowCodeOp(&s, WINDOW_AGGSTEP, 0, 0);

  148599.     if( pMWin->eEnd!=TK_UNBOUNDED ){

  148600.       if( pMWin->eFrmType==TK_RANGE ){

  148601.         int lbl = 0;

  148602.         addr = sqlite3VdbeCurrentAddr(v);

  148603.         if( regEnd ){

  148604.           lbl = sqlite3VdbeMakeLabel(pParse);

  148605.           windowCodeRangeTest(&s, OP_Ge, s.current.csr, regEnd, s.end.csr, lbl);

  148606.         }

  148607.         windowCodeOp(&s, WINDOW_RETURN_ROW, 0, 0);

  148608.         windowCodeOp(&s, WINDOW_AGGINVERSE, regStart, 0);

  148609.         if( regEnd ){

  148610.           sqlite3VdbeAddOp2(v, OP_Goto, 0, addr);

  148611.           sqlite3VdbeResolveLabel(v, lbl);

  148612.         }

  148613.       }else{

  148614.         if( regEnd ){

  148615.           addr = sqlite3VdbeAddOp3(v, OP_IfPos, regEnd, 0, 1);

  148616.           VdbeCoverage(v);

  148617.         }

  148618.         windowCodeOp(&s, WINDOW_RETURN_ROW, 0, 0);

  148619.         windowCodeOp(&s, WINDOW_AGGINVERSE, regStart, 0);

  148620.         if( regEnd ) sqlite3VdbeJumpHere(v, addr);

  148621.       }

  148622.     }

  148623.   }

  148624. 

  148625.   /* End of the main input loop */

  148626.   sqlite3VdbeResolveLabel(v, lblWhereEnd);

  148627.   sqlite3WhereEnd(pWInfo);

  148628. 

  148629.   /* Fall through */

  148630.   if( pMWin->pPartition ){

  148631.     addrInteger = sqlite3VdbeAddOp2(v, OP_Integer, 0, regFlushPart);

  148632.     sqlite3VdbeJumpHere(v, addrGosubFlush);

  148633.   }

  148634. 

  148635.   addrEmpty = sqlite3VdbeAddOp1(v, OP_Rewind, csrWrite);

  148636.   VdbeCoverage(v);

  148637.   if( pMWin->eEnd==TK_PRECEDING ){

  148638.     int bRPS = (pMWin->eStart==TK_PRECEDING && pMWin->eFrmType==TK_RANGE);

  148639.     windowCodeOp(&s, WINDOW_AGGSTEP, regEnd, 0);

  148640.     if( bRPS ) windowCodeOp(&s, WINDOW_AGGINVERSE, regStart, 0);

  148641.     windowCodeOp(&s, WINDOW_RETURN_ROW, 0, 0);

  148642.   }else if( pMWin->eStart==TK_FOLLOWING ){

  148643.     int addrStart;

  148644.     int addrBreak1;

  148645.     int addrBreak2;

  148646.     int addrBreak3;

  148647.     windowCodeOp(&s, WINDOW_AGGSTEP, 0, 0);

  148648.     if( pMWin->eFrmType==TK_RANGE ){

  148649.       addrStart = sqlite3VdbeCurrentAddr(v);

  148650.       addrBreak2 = windowCodeOp(&s, WINDOW_AGGINVERSE, regStart, 1);

  148651.       addrBreak1 = windowCodeOp(&s, WINDOW_RETURN_ROW, 0, 1);

  148652.     }else

  148653.     if( pMWin->eEnd==TK_UNBOUNDED ){

  148654.       addrStart = sqlite3VdbeCurrentAddr(v);

  148655.       addrBreak1 = windowCodeOp(&s, WINDOW_RETURN_ROW, regStart, 1);

  148656.       addrBreak2 = windowCodeOp(&s, WINDOW_AGGINVERSE, 0, 1);

  148657.     }else{

  148658.       assert( pMWin->eEnd==TK_FOLLOWING );

  148659.       addrStart = sqlite3VdbeCurrentAddr(v);

  148660.       addrBreak1 = windowCodeOp(&s, WINDOW_RETURN_ROW, regEnd, 1);

  148661.       addrBreak2 = windowCodeOp(&s, WINDOW_AGGINVERSE, regStart, 1);

  148662.     }

  148663.     sqlite3VdbeAddOp2(v, OP_Goto, 0, addrStart);

  148664.     sqlite3VdbeJumpHere(v, addrBreak2);

  148665.     addrStart = sqlite3VdbeCurrentAddr(v);

  148666.     addrBreak3 = windowCodeOp(&s, WINDOW_RETURN_ROW, 0, 1);

  148667.     sqlite3VdbeAddOp2(v, OP_Goto, 0, addrStart);

  148668.     sqlite3VdbeJumpHere(v, addrBreak1);

  148669.     sqlite3VdbeJumpHere(v, addrBreak3);

  148670.   }else{

  148671.     int addrBreak;

  148672.     int addrStart;

  148673.     windowCodeOp(&s, WINDOW_AGGSTEP, 0, 0);

  148674.     addrStart = sqlite3VdbeCurrentAddr(v);

  148675.     addrBreak = windowCodeOp(&s, WINDOW_RETURN_ROW, 0, 1);

  148676.     windowCodeOp(&s, WINDOW_AGGINVERSE, regStart, 0);

  148677.     sqlite3VdbeAddOp2(v, OP_Goto, 0, addrStart);

  148678.     sqlite3VdbeJumpHere(v, addrBreak);

  148679.   }

  148680.   sqlite3VdbeJumpHere(v, addrEmpty);

  148681. 

  148682.   sqlite3VdbeAddOp1(v, OP_ResetSorter, s.current.csr);

  148683.   if( pMWin->pPartition ){

  148684.     if( pMWin->regStartRowid ){

  148685.       sqlite3VdbeAddOp2(v, OP_Integer, 1, pMWin->regStartRowid);

  148686.       sqlite3VdbeAddOp2(v, OP_Integer, 0, pMWin->regEndRowid);

  148687.     }

  148688.     sqlite3VdbeChangeP1(v, addrInteger, sqlite3VdbeCurrentAddr(v));

  148689.     sqlite3VdbeAddOp1(v, OP_Return, regFlushPart);

  148690.   }

  148691. }

  148692. 

  148693. #endif /* SQLITE_OMIT_WINDOWFUNC */

  148694. 

  148695. /************** End of window.c **********************************************/

  148696. /************** Begin file parse.c *******************************************/

  148697. /*

  148698. ** 2000-05-29

  148699. **

  148700. ** The author disclaims copyright to this source code.  In place of

  148701. ** a legal notice, here is a blessing:

  148702. **

  148703. **    May you do good and not evil.

  148704. **    May you find forgiveness for yourself and forgive others.

  148705. **    May you share freely, never taking more than you give.

  148706. **

  148707. *************************************************************************

  148708. ** Driver template for the LEMON parser generator.

  148709. **

  148710. ** The "lemon" program processes an LALR(1) input grammar file, then uses

  148711. ** this template to construct a parser.  The "lemon" program inserts text

  148712. ** at each "%%" line.  Also, any "P-a-r-s-e" identifer prefix (without the

  148713. ** interstitial "-" characters) contained in this template is changed into

  148714. ** the value of the %name directive from the grammar.  Otherwise, the content

  148715. ** of this template is copied straight through into the generate parser

  148716. ** source file.

  148717. **

  148718. ** The following is the concatenation of all %include directives from the

  148719. ** input grammar file:

  148720. */

  148721. /* #include <stdio.h> */

  148722. /* #include <assert.h> */

  148723. /************ Begin %include sections from the grammar ************************/

  148724. 

  148725. /* #include "sqliteInt.h" */

  148726. 

  148727. /*

  148728. ** Disable all error recovery processing in the parser push-down

  148729. ** automaton.

  148730. */

  148731. #define YYNOERRORRECOVERY 1

  148732. 

  148733. /*

  148734. ** Make yytestcase() the same as testcase()

  148735. */

  148736. #define yytestcase(X) testcase(X)

  148737. 

  148738. /*

  148739. ** Indicate that sqlite3ParserFree() will never be called with a null

  148740. ** pointer.

  148741. */

  148742. #define YYPARSEFREENEVERNULL 1

  148743. 

  148744. /*

  148745. ** In the amalgamation, the parse.c file generated by lemon and the

  148746. ** tokenize.c file are concatenated.  In that case, sqlite3RunParser()

  148747. ** has access to the the size of the yyParser object and so the parser

  148748. ** engine can be allocated from stack.  In that case, only the

  148749. ** sqlite3ParserInit() and sqlite3ParserFinalize() routines are invoked

  148750. ** and the sqlite3ParserAlloc() and sqlite3ParserFree() routines can be

  148751. ** omitted.

  148752. */

  148753. #ifdef SQLITE_AMALGAMATION

  148754. # define sqlite3Parser_ENGINEALWAYSONSTACK 1

  148755. #endif

  148756. 

  148757. /*

  148758. ** Alternative datatype for the argument to the malloc() routine passed

  148759. ** into sqlite3ParserAlloc().  The default is size_t.

  148760. */

  148761. #define YYMALLOCARGTYPE  u64

  148762. 

  148763. /*

  148764. ** An instance of the following structure describes the event of a

  148765. ** TRIGGER.  "a" is the event type, one of TK_UPDATE, TK_INSERT,

  148766. ** TK_DELETE, or TK_INSTEAD.  If the event is of the form

  148767. **

  148768. **      UPDATE ON (a,b,c)

  148769. **

  148770. ** Then the "b" IdList records the list "a,b,c".

  148771. */

  148772. struct TrigEvent { int a; IdList * b; };

  148773. 

  148774. struct FrameBound     { int eType; Expr *pExpr; };

  148775. 

  148776. /*

  148777. ** Disable lookaside memory allocation for objects that might be

  148778. ** shared across database connections.

  148779. */

  148780. static void disableLookaside(Parse *pParse){

  148781.   pParse->disableLookaside++;

  148782.   pParse->db->lookaside.bDisable++;

  148783. }

  148784. 

  148785. 

  148786.   /*

  148787.   ** For a compound SELECT statement, make sure p->pPrior->pNext==p for

  148788.   ** all elements in the list.  And make sure list length does not exceed

  148789.   ** SQLITE_LIMIT_COMPOUND_SELECT.

  148790.   */

  148791.   static void parserDoubleLinkSelect(Parse *pParse, Select *p){

  148792.     if( p->pPrior ){

  148793.       Select *pNext = 0, *pLoop;

  148794.       int mxSelect, cnt = 0;

  148795.       for(pLoop=p; pLoop; pNext=pLoop, pLoop=pLoop->pPrior, cnt++){

  148796.         pLoop->pNext = pNext;

  148797.         pLoop->selFlags |= SF_Compound;

  148798.       }

  148799.       if( (p->selFlags & SF_MultiValue)==0 && 

  148800.         (mxSelect = pParse->db->aLimit[SQLITE_LIMIT_COMPOUND_SELECT])>0 &&

  148801.         cnt>mxSelect

  148802.       ){

  148803.         sqlite3ErrorMsg(pParse, "too many terms in compound SELECT");

  148804.       }

  148805.     }

  148806.   }

  148807. 

  148808. 

  148809.   /* Construct a new Expr object from a single identifier.  Use the

  148810.   ** new Expr to populate pOut.  Set the span of pOut to be the identifier

  148811.   ** that created the expression.

  148812.   */

  148813.   static Expr *tokenExpr(Parse *pParse, int op, Token t){

  148814.     Expr *p = sqlite3DbMallocRawNN(pParse->db, sizeof(Expr)+t.n+1);

  148815.     if( p ){

  148816.       /* memset(p, 0, sizeof(Expr)); */

  148817.       p->op = (u8)op;

  148818.       p->affinity = 0;

  148819.       p->flags = EP_Leaf;

  148820.       p->iAgg = -1;

  148821.       p->pLeft = p->pRight = 0;

  148822.       p->x.pList = 0;

  148823.       p->pAggInfo = 0;

  148824.       p->y.pTab = 0;

  148825.       p->op2 = 0;

  148826.       p->iTable = 0;

  148827.       p->iColumn = 0;

  148828.       p->u.zToken = (char*)&p[1];

  148829.       memcpy(p->u.zToken, t.z, t.n);

  148830.       p->u.zToken[t.n] = 0;

  148831.       if( sqlite3Isquote(p->u.zToken[0]) ){

  148832.         sqlite3DequoteExpr(p);

  148833.       }

  148834. #if SQLITE_MAX_EXPR_DEPTH>0

  148835.       p->nHeight = 1;

  148836. #endif  

  148837.       if( IN_RENAME_OBJECT ){

  148838.         return (Expr*)sqlite3RenameTokenMap(pParse, (void*)p, &t);

  148839.       }

  148840.     }

  148841.     return p;

  148842.   }

  148843. 

  148844. 

  148845.   /* A routine to convert a binary TK_IS or TK_ISNOT expression into a

  148846.   ** unary TK_ISNULL or TK_NOTNULL expression. */

  148847.   static void binaryToUnaryIfNull(Parse *pParse, Expr *pY, Expr *pA, int op){

  148848.     sqlite3 *db = pParse->db;

  148849.     if( pA && pY && pY->op==TK_NULL && !IN_RENAME_OBJECT ){

  148850.       pA->op = (u8)op;

  148851.       sqlite3ExprDelete(db, pA->pRight);

  148852.       pA->pRight = 0;

  148853.     }

  148854.   }

  148855. 

  148856.   /* Add a single new term to an ExprList that is used to store a

  148857.   ** list of identifiers.  Report an error if the ID list contains

  148858.   ** a COLLATE clause or an ASC or DESC keyword, except ignore the

  148859.   ** error while parsing a legacy schema.

  148860.   */

  148861.   static ExprList *parserAddExprIdListTerm(

  148862.     Parse *pParse,

  148863.     ExprList *pPrior,

  148864.     Token *pIdToken,

  148865.     int hasCollate,

  148866.     int sortOrder

  148867.   ){

  148868.     ExprList *p = sqlite3ExprListAppend(pParse, pPrior, 0);

  148869.     if( (hasCollate || sortOrder!=SQLITE_SO_UNDEFINED)

  148870.         && pParse->db->init.busy==0

  148871.     ){

  148872.       sqlite3ErrorMsg(pParse, "syntax error after column name \"%.*s\"",

  148873.                          pIdToken->n, pIdToken->z);

  148874.     }

  148875.     sqlite3ExprListSetName(pParse, p, pIdToken, 1);

  148876.     return p;

  148877.   }

  148878. 

  148879. #if TK_SPAN>255

  148880. # error too many tokens in the grammar

  148881. #endif

  148882. /**************** End of %include directives **********************************/

  148883. /* These constants specify the various numeric values for terminal symbols

  148884. ** in a format understandable to "makeheaders".  This section is blank unless

  148885. ** "lemon" is run with the "-m" command-line option.

  148886. ***************** Begin makeheaders token definitions *************************/

  148887. /**************** End makeheaders token definitions ***************************/

  148888. 

  148889. /* The next sections is a series of control #defines.

  148890. ** various aspects of the generated parser.

  148891. **    YYCODETYPE         is the data type used to store the integer codes

  148892. **                       that represent terminal and non-terminal symbols.

  148893. **                       "unsigned char" is used if there are fewer than

  148894. **                       256 symbols.  Larger types otherwise.

  148895. **    YYNOCODE           is a number of type YYCODETYPE that is not used for

  148896. **                       any terminal or nonterminal symbol.

  148897. **    YYFALLBACK         If defined, this indicates that one or more tokens

  148898. **                       (also known as: "terminal symbols") have fall-back

  148899. **                       values which should be used if the original symbol

  148900. **                       would not parse.  This permits keywords to sometimes

  148901. **                       be used as identifiers, for example.

  148902. **    YYACTIONTYPE       is the data type used for "action codes" - numbers

  148903. **                       that indicate what to do in response to the next

  148904. **                       token.

  148905. **    sqlite3ParserTOKENTYPE     is the data type used for minor type for terminal

  148906. **                       symbols.  Background: A "minor type" is a semantic

  148907. **                       value associated with a terminal or non-terminal

  148908. **                       symbols.  For example, for an "ID" terminal symbol,

  148909. **                       the minor type might be the name of the identifier.

  148910. **                       Each non-terminal can have a different minor type.

  148911. **                       Terminal symbols all have the same minor type, though.

  148912. **                       This macros defines the minor type for terminal 

  148913. **                       symbols.

  148914. **    YYMINORTYPE        is the data type used for all minor types.

  148915. **                       This is typically a union of many types, one of

  148916. **                       which is sqlite3ParserTOKENTYPE.  The entry in the union

  148917. **                       for terminal symbols is called "yy0".

  148918. **    YYSTACKDEPTH       is the maximum depth of the parser's stack.  If

  148919. **                       zero the stack is dynamically sized using realloc()

  148920. **    sqlite3ParserARG_SDECL     A static variable declaration for the %extra_argument

  148921. **    sqlite3ParserARG_PDECL     A parameter declaration for the %extra_argument

  148922. **    sqlite3ParserARG_PARAM     Code to pass %extra_argument as a subroutine parameter

  148923. **    sqlite3ParserARG_STORE     Code to store %extra_argument into yypParser

  148924. **    sqlite3ParserARG_FETCH     Code to extract %extra_argument from yypParser

  148925. **    sqlite3ParserCTX_*         As sqlite3ParserARG_ except for %extra_context

  148926. **    YYERRORSYMBOL      is the code number of the error symbol.  If not

  148927. **                       defined, then do no error processing.

  148928. **    YYNSTATE           the combined number of states.

  148929. **    YYNRULE            the number of rules in the grammar

  148930. **    YYNTOKEN           Number of terminal symbols

  148931. **    YY_MAX_SHIFT       Maximum value for shift actions

  148932. **    YY_MIN_SHIFTREDUCE Minimum value for shift-reduce actions

  148933. **    YY_MAX_SHIFTREDUCE Maximum value for shift-reduce actions

  148934. **    YY_ERROR_ACTION    The yy_action[] code for syntax error

  148935. **    YY_ACCEPT_ACTION   The yy_action[] code for accept

  148936. **    YY_NO_ACTION       The yy_action[] code for no-op

  148937. **    YY_MIN_REDUCE      Minimum value for reduce actions

  148938. **    YY_MAX_REDUCE      Maximum value for reduce actions

  148939. */

  148940. #ifndef INTERFACE

  148941. # define INTERFACE 1

  148942. #endif

  148943. /************* Begin control #defines *****************************************/

  148944. #define YYCODETYPE unsigned short int

  148945. #define YYNOCODE 302

  148946. #define YYACTIONTYPE unsigned short int

  148947. #define YYWILDCARD 95

  148948. #define sqlite3ParserTOKENTYPE Token

  148949. typedef union {

  148950.   int yyinit;

  148951.   sqlite3ParserTOKENTYPE yy0;

  148952.   TriggerStep* yy11;

  148953.   IdList* yy76;

  148954.   ExprList* yy94;

  148955.   Upsert* yy95;

  148956.   int yy100;

  148957.   Expr* yy102;

  148958.   struct {int value; int mask;} yy199;

  148959.   u8 yy218;

  148960.   With* yy243;

  148961.   struct TrigEvent yy298;

  148962.   Window* yy379;

  148963.   struct FrameBound yy389;

  148964.   Select* yy391;

  148965.   SrcList* yy407;

  148966.   const char* yy528;

  148967. } YYMINORTYPE;

  148968. #ifndef YYSTACKDEPTH

  148969. #define YYSTACKDEPTH 100

  148970. #endif

  148971. #define sqlite3ParserARG_SDECL

  148972. #define sqlite3ParserARG_PDECL

  148973. #define sqlite3ParserARG_PARAM

  148974. #define sqlite3ParserARG_FETCH

  148975. #define sqlite3ParserARG_STORE

  148976. #define sqlite3ParserCTX_SDECL Parse *pParse;

  148977. #define sqlite3ParserCTX_PDECL ,Parse *pParse

  148978. #define sqlite3ParserCTX_PARAM ,pParse

  148979. #define sqlite3ParserCTX_FETCH Parse *pParse=yypParser->pParse;

  148980. #define sqlite3ParserCTX_STORE yypParser->pParse=pParse;

  148981. #define YYFALLBACK 1

  148982. #define YYNSTATE             540

  148983. #define YYNRULE              376

  148984. #define YYNTOKEN             176

  148985. #define YY_MAX_SHIFT         539

  148986. #define YY_MIN_SHIFTREDUCE   783

  148987. #define YY_MAX_SHIFTREDUCE   1158

  148988. #define YY_ERROR_ACTION      1159

  148989. #define YY_ACCEPT_ACTION     1160

  148990. #define YY_NO_ACTION         1161

  148991. #define YY_MIN_REDUCE        1162

  148992. #define YY_MAX_REDUCE        1537

  148993. /************* End control #defines *******************************************/

  148994. #define YY_NLOOKAHEAD ((int)(sizeof(yy_lookahead)/sizeof(yy_lookahead[0])))

  148995. 

  148996. /* Define the yytestcase() macro to be a no-op if is not already defined

  148997. ** otherwise.

  148998. **

  148999. ** Applications can choose to define yytestcase() in the %include section

  149000. ** to a macro that can assist in verifying code coverage.  For production

  149001. ** code the yytestcase() macro should be turned off.  But it is useful

  149002. ** for testing.

  149003. */

  149004. #ifndef yytestcase

  149005. # define yytestcase(X)

  149006. #endif

  149007. 

  149008. 

  149009. /* Next are the tables used to determine what action to take based on the

  149010. ** current state and lookahead token.  These tables are used to implement

  149011. ** functions that take a state number and lookahead value and return an

  149012. ** action integer.  

  149013. **

  149014. ** Suppose the action integer is N.  Then the action is determined as

  149015. ** follows

  149016. **

  149017. **   0 <= N <= YY_MAX_SHIFT             Shift N.  That is, push the lookahead

  149018. **                                      token onto the stack and goto state N.

  149019. **

  149020. **   N between YY_MIN_SHIFTREDUCE       Shift to an arbitrary state then

  149021. **     and YY_MAX_SHIFTREDUCE           reduce by rule N-YY_MIN_SHIFTREDUCE.

  149022. **

  149023. **   N == YY_ERROR_ACTION               A syntax error has occurred.

  149024. **

  149025. **   N == YY_ACCEPT_ACTION              The parser accepts its input.

  149026. **

  149027. **   N == YY_NO_ACTION                  No such action.  Denotes unused

  149028. **                                      slots in the yy_action[] table.

  149029. **

  149030. **   N between YY_MIN_REDUCE            Reduce by rule N-YY_MIN_REDUCE

  149031. **     and YY_MAX_REDUCE

  149032. **

  149033. ** The action table is constructed as a single large table named yy_action[].

  149034. ** Given state S and lookahead X, the action is computed as either:

  149035. **

  149036. **    (A)   N = yy_action[ yy_shift_ofst[S] + X ]

  149037. **    (B)   N = yy_default[S]

  149038. **

  149039. ** The (A) formula is preferred.  The B formula is used instead if

  149040. ** yy_lookahead[yy_shift_ofst[S]+X] is not equal to X.

  149041. **

  149042. ** The formulas above are for computing the action when the lookahead is

  149043. ** a terminal symbol.  If the lookahead is a non-terminal (as occurs after

  149044. ** a reduce action) then the yy_reduce_ofst[] array is used in place of

  149045. ** the yy_shift_ofst[] array.

  149046. **

  149047. ** The following are the tables generated in this section:

  149048. **

  149049. **  yy_action[]        A single table containing all actions.

  149050. **  yy_lookahead[]     A table containing the lookahead for each entry in

  149051. **                     yy_action.  Used to detect hash collisions.

  149052. **  yy_shift_ofst[]    For each state, the offset into yy_action for

  149053. **                     shifting terminals.

  149054. **  yy_reduce_ofst[]   For each state, the offset into yy_action for

  149055. **                     shifting non-terminals after a reduce.

  149056. **  yy_default[]       Default action for each state.

  149057. **

  149058. *********** Begin parsing tables **********************************************/

  149059. #define YY_ACTTAB_COUNT (2142)

  149060. static const YYACTIONTYPE yy_action[] = {

  149061.  /*     0 */   112,  109,  209,  112,  109,  209, 1160,    1,    1,  539,

  149062.  /*    10 */     2, 1164,  490, 1193, 1293,  534,  289, 1196,  134,  383,

  149063.  /*    20 */  1485, 1428, 1164, 1229, 1208, 1242, 1195,  289,  491,  134,

  149064.  /*    30 */   373,  915, 1229,  443,   16,   16, 1242,   70,   70,  916,

  149065.  /*    40 */   242, 1292,  296,  119,  120,  110, 1136, 1136,  981,  984,

  149066.  /*    50 */   974,  974,  117,  117,  118,  118,  118,  118,  264,  264,

  149067.  /*    60 */   190,  264,  264,  264,  264,  112,  109,  209,  362,  264,

  149068.  /*    70 */   264,  531,  376,  497,  531, 1134,  531, 1501,  239,  206,

  149069.  /*    80 */   338,    9,  531,  242,  219, 1203,  118,  118,  118,  118,

  149070.  /*    90 */   111,  439,  112,  109,  209,  219,  116,  116,  116,  116,

  149071.  /*   100 */   115,  115,  114,  114,  114,  113,  414,  115,  115,  114,

  149072.  /*   110 */   114,  114,  113,  414,  418,   12,  383,  400, 1134,  114,

  149073.  /*   120 */   114,  114,  113,  414, 1115,  418, 1134, 1392,  116,  116,

  149074.  /*   130 */   116,  116,  115,  115,  114,  114,  114,  113,  414,  961,

  149075.  /*   140 */   119,  120,  110, 1136, 1136,  981,  984,  974,  974,  117,

  149076.  /*   150 */   117,  118,  118,  118,  118,  952,  534,  414,  941,  951,

  149077.  /*   160 */  1481,  539,    2, 1164, 1505,  534,  160,  175,  289, 1134,

  149078.  /*   170 */   134,  434,  312,  297, 1115, 1116, 1117, 1242,   70,   70,

  149079.  /*   180 */  1089,  338, 1089,  118,  118,  118,  118,   42,   42,  448,

  149080.  /*   190 */   951,  951,  953,  116,  116,  116,  116,  115,  115,  114,

  149081.  /*   200 */   114,  114,  113,  414, 1115,  311,  264,  264,   82,  441,

  149082.  /*   210 */   264,  264,  190,  383,  284,   12,  288,  525,  407,  531,

  149083.  /*   220 */    96,  159,  458,  531,  371,  116,  116,  116,  116,  115,

  149084.  /*   230 */   115,  114,  114,  114,  113,  414,  219,  119,  120,  110,

  149085.  /*   240 */  1136, 1136,  981,  984,  974,  974,  117,  117,  118,  118,

  149086.  /*   250 */   118,  118,  511, 1477, 1115, 1116, 1117,  113,  414,  534,

  149087.  /*   260 */   528,  528,  528,  121,  534, 1427,  418,  116,  116,  116,

  149088.  /*   270 */   116,  115,  115,  114,  114,  114,  113,  414, 1464,  351,

  149089.  /*   280 */   270,   42,   42,  383,  187, 1115,   70,   70,  533,  433,

  149090.  /*   290 */   116,  116,  116,  116,  115,  115,  114,  114,  114,  113,

  149091.  /*   300 */   414,  534, 1339,  405,  159,  411,  410,  119,  120,  110,

  149092.  /*   310 */  1136, 1136,  981,  984,  974,  974,  117,  117,  118,  118,

  149093.  /*   320 */   118,  118,  285,   42,   42,  349,  411,  410,  514,  479,

  149094.  /*   330 */  1458,   79, 1084,    6, 1140, 1115, 1116, 1117,  480, 1142,

  149095.  /*   340 */   501, 1115, 1084,  123,  238, 1084,  136, 1141, 1234, 1234,

  149096.  /*   350 */  1143,  383, 1143, 1115,  167,  426,   80,  447,  512, 1451,

  149097.  /*   360 */   116,  116,  116,  116,  115,  115,  114,  114,  114,  113,

  149098.  /*   370 */   414, 1143, 1466, 1143,  350,  119,  120,  110, 1136, 1136,

  149099.  /*   380 */   981,  984,  974,  974,  117,  117,  118,  118,  118,  118,

  149100.  /*   390 */   402, 1115, 1116, 1117,  500,  534,  250,  267,  336,  474,

  149101.  /*   400 */   331,  473,  236, 1115, 1116, 1117,  231, 1115,  329,  471,

  149102.  /*   410 */   468,  467,  509, 1458, 1464,  505,    6,   70,   70,  466,

  149103.  /*   420 */   181,  380,  379,  534,  971,  971,  982,  985,  116,  116,

  149104.  /*   430 */   116,  116,  115,  115,  114,  114,  114,  113,  414, 1115,

  149105.  /*   440 */   412,  412,  412,  496, 1115,   69,   69,  235,  383,  288,

  149106.  /*   450 */   525,  273,  326,  516,  337,  458, 1084, 1115, 1116, 1117,

  149107.  /*   460 */  1232, 1232,  492,  160,  508,  441, 1084, 1067, 1531, 1084,

  149108.  /*   470 */   207, 1531,  119,  120,  110, 1136, 1136,  981,  984,  974,

  149109.  /*   480 */   974,  117,  117,  118,  118,  118,  118,  881,  534, 1115,

  149110.  /*   490 */  1116, 1117,  975,  534, 1115, 1116, 1117,  534,  421,  534,

  149111.  /*   500 */   141,  534,  176,  356,  517, 1119,   32,  511,  482,  388,

  149112.  /*   510 */    70,   70,  818,  288,  525,   70,   70,  441,  499,   50,

  149113.  /*   520 */    50,   70,   70,   70,   70,  116,  116,  116,  116,  115,

  149114.  /*   530 */   115,  114,  114,  114,  113,  414,  274,  264,  264, 1115,

  149115.  /*   540 */  1065,  264,  264, 1115,  355,  383,  409,  961, 1439,  822,

  149116.  /*   550 */   531,  516,  190,  419,  531,  483, 1119,  516,  337,  516,

  149117.  /*   560 */   518, 1115,  818,  952,  382,  458,  515,  951,  481,  119,

  149118.  /*   570 */   120,  110, 1136, 1136,  981,  984,  974,  974,  117,  117,

  149119.  /*   580 */   118,  118,  118,  118, 1338,  278, 1045,  278,  275, 1115,

  149120.  /*   590 */  1116, 1117,  259, 1115, 1116, 1117,  534,    5,  951,  951,

  149121.  /*   600 */   953, 1046,  231,    3,  143,  471,  468,  467, 1391,  463,

  149122.  /*   610 */  1115, 1115, 1116, 1117, 1452,  466, 1047,  836,   70,   70,

  149123.  /*   620 */   480,  534,  116,  116,  116,  116,  115,  115,  114,  114,

  149124.  /*   630 */   114,  113,  414,   95, 1115,  287,  235,  856,  902,  420,

  149125.  /*   640 */  1115,  534,  383,   13,   13,  381,  815,  857,  472,  112,

  149126.  /*   650 */   109,  209, 1115,  337,  413,  309,  837,  394, 1436,  534,

  149127.  /*   660 */  1115, 1116, 1117,   54,   54,  291,  119,  120,  110, 1136,

  149128.  /*   670 */  1136,  981,  984,  974,  974,  117,  117,  118,  118,  118,

  149129.  /*   680 */   118,   13,   13, 1084, 1115, 1116, 1117,  901,  264,  264,

  149130.  /*   690 */  1115, 1116, 1117, 1084,  292,  399, 1084,  800,  388,  140,

  149131.  /*   700 */   295,  531, 1115, 1116, 1117,  403,  447,  532,  534,  870,

  149132.  /*   710 */   870,  534, 1240,  534,  329,  534, 1185,  389,  534,  116,

  149133.  /*   720 */   116,  116,  116,  115,  115,  114,  114,  114,  113,  414,

  149134.  /*   730 */    13,   13, 1024,   13,   13,   13,   13,   13,   13,  383,

  149135.  /*   740 */    13,   13,  424, 1100,  401,  264,  264,  277,  160,  184,

  149136.  /*   750 */  1182,  185, 1533,  369,  513,  484,  432,  487,  531,  424,

  149137.  /*   760 */   423, 1397,  941,  119,  120,  110, 1136, 1136,  981,  984,

  149138.  /*   770 */   974,  974,  117,  117,  118,  118,  118,  118, 1397, 1399,

  149139.  /*   780 */   425,  519,  392,  264,  264, 1029, 1029,  455,  264,  264,

  149140.  /*   790 */   264,  264, 1004,  304,  261, 1278,  531,  900,  288,  525,

  149141.  /*   800 */   310,  531,  493,  531, 1067, 1532,  458,  387, 1532,  311,

  149142.  /*   810 */   429,  299,  534,  107,  264,  264,  116,  116,  116,  116,

  149143.  /*   820 */   115,  115,  114,  114,  114,  113,  414,  531,  424, 1384,

  149144.  /*   830 */   507,  258,  258, 1246,   55,   55,  383, 1277,  265,  265,

  149145.  /*   840 */   962,  324,  434,  312,  531,  531,  506, 1397, 1026, 1241,

  149146.  /*   850 */   298,  531, 1026,  445,  301, 1095,  303,  534,  368, 1156,

  149147.  /*   860 */   119,  120,  110, 1136, 1136,  981,  984,  974,  974,  117,

  149148.  /*   870 */   117,  118,  118,  118,  118, 1045,  534, 1065,  534,   15,

  149149.  /*   880 */    15, 1084,  208, 1324,  453,  452,  534, 1324,  534,  449,

  149150.  /*   890 */  1046, 1084,  494,  458, 1084,  234,  233,  232,   44,   44,

  149151.  /*   900 */    56,   56,  319, 1095,  322, 1047,  534,  900,   57,   57,

  149152.  /*   910 */    58,   58,  534,  116,  116,  116,  116,  115,  115,  114,

  149153.  /*   920 */   114,  114,  113,  414,  534,  514,  522,  534,   59,   59,

  149154.  /*   930 */   302, 1157,  534,  383,   60,   60, 1237,  946,  788,  789,

  149155.  /*   940 */   790, 1459, 1456,  446,    6,    6,   61,   61, 1212,   45,

  149156.  /*   950 */    45,  534,  396,  383,   46,   46,  397,  119,  120,  110,

  149157.  /*   960 */  1136, 1136,  981,  984,  974,  974,  117,  117,  118,  118,

  149158.  /*   970 */   118,  118,  428,   48,   48,  534,  392,  119,  120,  110,

  149159.  /*   980 */  1136, 1136,  981,  984,  974,  974,  117,  117,  118,  118,

  149160.  /*   990 */   118,  118, 1324,  368, 1066,  447,  825,   49,   49,  534,

  149161.  /*  1000 */   458,  357,  534,  353,  534,  138,  534,  337, 1478,  478,

  149162.  /*  1010 */   116,  116,  116,  116,  115,  115,  114,  114,  114,  113,

  149163.  /*  1020 */   414,   62,   62,  392,   63,   63,   64,   64,   14,   14,

  149164.  /*  1030 */   116,  116,  116,  116,  115,  115,  114,  114,  114,  113,

  149165.  /*  1040 */   414,  534,  810,  317,  271,  534, 1457,  825,  534,    6,

  149166.  /*  1050 */   534, 1324,  534,  142,  534, 1442,  534,  212,  534, 1324,

  149167.  /*  1060 */   534,  398,  305,   65,   65,  534, 1157,  125,  125,  476,

  149168.  /*  1070 */    66,   66,   51,   51,   67,   67,   68,   68,   52,   52,

  149169.  /*  1080 */   147,  147,  148,  148,  534,   98,  534,   75,   75,  276,

  149170.  /*  1090 */   534,  272,  534,  810,  534,  876,  534,  527,  389,  534,

  149171.  /*  1100 */   875,  534, 1151,  202,  534,  383,   53,   53,   71,   71,

  149172.  /*  1110 */   288,  525,  126,  126,   72,   72,  127,  127,  128,  128,

  149173.  /*  1120 */   454,  124,  124,  146,  146,  383,  145,  145,  408,  119,

  149174.  /*  1130 */   120,  110, 1136, 1136,  981,  984,  974,  974,  117,  117,

  149175.  /*  1140 */   118,  118,  118,  118,  534,  900,  534,   95,  534,  119,

  149176.  /*  1150 */   120,  110, 1136, 1136,  981,  984,  974,  974,  117,  117,

  149177.  /*  1160 */   118,  118,  118,  118,  390,  161,  132,  132,  131,  131,

  149178.  /*  1170 */   129,  129,  534,  915,  534, 1455,  534, 1454,    6, 1416,

  149179.  /*  1180 */     6,  916,  116,  116,  116,  116,  115,  115,  114,  114,

  149180.  /*  1190 */   114,  113,  414, 1415,  130,  130,   74,   74,   76,   76,

  149181.  /*  1200 */   534,   30,  116,  116,  116,  116,  115,  115,  114,  114,

  149182.  /*  1210 */   114,  113,  414,  534,  263,  206,  534, 1133, 1504,   93,

  149183.  /*  1220 */   876,  845,   73,   73,  102,  875,  100,  139,   17,   38,

  149184.  /*  1230 */   208, 1062,   31,  450,  370,   43,   43,  101,   47,   47,

  149185.  /*  1240 */   827,  216,  436,  308,  943,  440,   95,  241,  241,  442,

  149186.  /*  1250 */   313,  464,  241,   95,  237,  900,  327,  383,  266,   95,

  149187.  /*  1260 */   835,  834,  193,  335,  938,  314, 1011,  435,  842,  843,

  149188.  /*  1270 */   955, 1007,  909,  334,  237,  241,  873,  383, 1023,  107,

  149189.  /*  1280 */  1023,  119,  120,  110, 1136, 1136,  981,  984,  974,  974,

  149190.  /*  1290 */   117,  117,  118,  118,  118,  118, 1022,  808, 1022, 1274,

  149191.  /*  1300 */   137,  119,  108,  110, 1136, 1136,  981,  984,  974,  974,

  149192.  /*  1310 */   117,  117,  118,  118,  118,  118,  874, 1011,  318,  107,

  149193.  /*  1320 */   321,  955,  323,  325, 1225, 1211,  197, 1210, 1209,  330,

  149194.  /*  1330 */   339, 1265,  340,  283,  116,  116,  116,  116,  115,  115,

  149195.  /*  1340 */   114,  114,  114,  113,  414, 1286, 1323, 1261, 1471, 1272,

  149196.  /*  1350 */   520,  218,  521, 1329,  116,  116,  116,  116,  115,  115,

  149197.  /*  1360 */   114,  114,  114,  113,  414, 1192, 1184, 1173, 1172, 1174,

  149198.  /*  1370 */  1494, 1488,  459,  256,  383, 1258,  342,  199,  367,  344,

  149199.  /*  1380 */   211,  195,  307,  444,   11,  346,  469,  333, 1308, 1316,

  149200.  /*  1390 */   375,  427,  203,  360,  383, 1388,  188, 1387,  189,  120,

  149201.  /*  1400 */   110, 1136, 1136,  981,  984,  974,  974,  117,  117,  118,

  149202.  /*  1410 */   118,  118,  118, 1208, 1151,  300,  348, 1491,  245, 1148,

  149203.  /*  1420 */   110, 1136, 1136,  981,  984,  974,  974,  117,  117,  118,

  149204.  /*  1430 */   118,  118,  118,  198, 1435, 1433,  524,   78,  391,  163,

  149205.  /*  1440 */    82, 1393,  438,  173,   81,  105,  526, 1313,    4,   35,

  149206.  /*  1450 */   157,  116,  116,  116,  116,  115,  115,  114,  114,  114,

  149207.  /*  1460 */   113,  414,  529,  165,   93,  430, 1305,  168,  169,  431,

  149208.  /*  1470 */   462,  116,  116,  116,  116,  115,  115,  114,  114,  114,

  149209.  /*  1480 */   113,  414,  170,  171,  221,  415,  372,  437, 1319,  177,

  149210.  /*  1490 */   374,   36,  451,  225, 1382,   87,  457,  523,  257, 1404,

  149211.  /*  1500 */   316,  105,  526,  227,    4,  182,  460,  160,  320,  228,

  149212.  /*  1510 */   377, 1175,  475,  229, 1228,  404, 1227, 1226,  529,  827,

  149213.  /*  1520 */   961, 1219,  378, 1200, 1199,  406,  103,  103, 1218,  332,

  149214.  /*  1530 */     8,  281, 1198,  104, 1503,  415,  536,  535,  486,  282,

  149215.  /*  1540 */   951,  415,  489,  495,   92,  244, 1269,  341,  243,  122,

  149216.  /*  1550 */  1270,  343,  514,  523, 1268, 1462,   10,  288,  525,  345,

  149217.  /*  1560 */  1461,  354,   99,  352,  503,   94, 1267,  347, 1251,  502,

  149218.  /*  1570 */   498,  951,  951,  953,  954,   27,  961, 1250,  194,  358,

  149219.  /*  1580 */   251,  359,  103,  103, 1181,   34,  537, 1110,  252,  104,

  149220.  /*  1590 */   254,  415,  536,  535,  255, 1368,  951, 1420,  286,  538,

  149221.  /*  1600 */  1170, 1165, 1421,  135, 1419, 1418,  149,  150,  279,  784,

  149222.  /*  1610 */   416,  196,  151,  290,  210,  200,   77,  385,  269,  386,

  149223.  /*  1620 */   133,  162,  935, 1021,  201, 1019,  153,  951,  951,  953,

  149224.  /*  1630 */   954,   27, 1480, 1104,  417,  164,  217,  268,  859,  166,

  149225.  /*  1640 */   306, 1035,  366,  366,  365,  253,  363,  220,  172,  797,

  149226.  /*  1650 */   939,  155,  105,  526,  393,    4,  395,  174,  156,   83,

  149227.  /*  1660 */  1038,   84,  213,   85,  294,  222,   86,  223, 1034,  529,

  149228.  /*  1670 */   144,   18,  293,  224,  315,  456,  241, 1027, 1145,  178,

  149229.  /*  1680 */   226,  179,   37,  799,  334,  461,  230,  465,  470,  838,

  149230.  /*  1690 */   180,   88,  415,   19,  280,  328,   20,   89,   90,  158,

  149231.  /*  1700 */   191,  477,  215, 1097,  523,  204,  192,  987,   91, 1070,

  149232.  /*  1710 */   152,   39,  485,  154, 1071,  503,   40,  488,  205,  260,

  149233.  /*  1720 */   504,  262,  105,  526,  214,    4,  908,  961,  183,  240,

  149234.  /*  1730 */   903,  107, 1086,  103,  103,   21,   22, 1088,   23,  529,

  149235.  /*  1740 */   104,   24,  415,  536,  535, 1090, 1093,  951, 1094,   25,

  149236.  /*  1750 */  1074,   33,    7,   26,  510, 1002,  247,  186,  384,   95,

  149237.  /*  1760 */   988,  986,  415,  288,  525,  990, 1044,  246, 1043,  991,

  149238.  /*  1770 */    28,   41,  530,  956,  523,  809,  106,   29,  951,  951,

  149239.  /*  1780 */   953,  954,   27,  869,  361,  503,  422,  248,  364, 1105,

  149240.  /*  1790 */   502,  249, 1161, 1496, 1495, 1161, 1161,  961, 1161, 1161,

  149241.  /*  1800 */  1161, 1161, 1161,  103,  103, 1161, 1161, 1161, 1161, 1161,

  149242.  /*  1810 */   104, 1161,  415,  536,  535, 1104,  417,  951, 1161,  268,

  149243.  /*  1820 */  1161, 1161, 1161, 1161,  366,  366,  365,  253,  363, 1161,

  149244.  /*  1830 */  1161,  797, 1161, 1161, 1161, 1161,  105,  526, 1161,    4,

  149245.  /*  1840 */  1161, 1161, 1161, 1161,  213, 1161,  294, 1161,  951,  951,

  149246.  /*  1850 */   953,  954,   27,  529,  293, 1161, 1161, 1161, 1161, 1161,

  149247.  /*  1860 */  1161, 1161, 1161, 1161, 1161, 1161, 1161, 1161, 1161, 1161,

  149248.  /*  1870 */  1161, 1161, 1161, 1161, 1161, 1161,  415, 1161, 1161, 1161,

  149249.  /*  1880 */  1161, 1161, 1161, 1161,  215, 1161, 1161, 1161,  523, 1161,

  149250.  /*  1890 */  1161, 1161,  152, 1161, 1161,  154,  105,  526, 1161,    4,

  149251.  /*  1900 */  1161, 1161, 1161, 1161, 1161, 1161,  214, 1161, 1161, 1161,

  149252.  /*  1910 */  1161,  961, 1161,  529, 1161, 1161, 1161,  103,  103,  880,

  149253.  /*  1920 */  1161, 1161, 1161, 1161,  104, 1161,  415,  536,  535, 1161,

  149254.  /*  1930 */  1161,  951, 1161, 1161, 1161, 1161,  415, 1161, 1161, 1161,

  149255.  /*  1940 */   384, 1161, 1161, 1161, 1161,  288,  525, 1161,  523, 1161,

  149256.  /*  1950 */  1161, 1161, 1161, 1161, 1161, 1161,   97,  526, 1161,    4,

  149257.  /*  1960 */  1161, 1161,  951,  951,  953,  954,   27, 1161,  422, 1161,

  149258.  /*  1970 */  1161,  961, 1161,  529, 1161, 1161, 1161,  103,  103, 1161,

  149259.  /*  1980 */  1161, 1161, 1161, 1161,  104, 1161,  415,  536,  535, 1161,

  149260.  /*  1990 */  1161,  951,  268, 1161, 1161, 1161,  415,  366,  366,  365,

  149261.  /*  2000 */   253,  363, 1161, 1161,  797, 1161, 1161, 1161,  523, 1161,

  149262.  /*  2010 */  1161, 1161, 1161, 1161, 1161, 1161, 1161,  213, 1161,  294,

  149263.  /*  2020 */  1161, 1161,  951,  951,  953,  954,   27,  293, 1161, 1161,

  149264.  /*  2030 */  1161,  961, 1161, 1161, 1161, 1161, 1161,  103,  103, 1161,

  149265.  /*  2040 */  1161, 1161, 1161, 1161,  104, 1161,  415,  536,  535, 1161,

  149266.  /*  2050 */  1161,  951, 1161, 1161, 1161, 1161, 1161,  215, 1161, 1161,

  149267.  /*  2060 */  1161, 1161, 1161, 1161, 1161,  152, 1161, 1161,  154, 1161,

  149268.  /*  2070 */  1161, 1161, 1161, 1161, 1161, 1161, 1161, 1161, 1161,  214,

  149269.  /*  2080 */  1161, 1161,  951,  951,  953,  954,   27, 1161, 1161, 1161,

  149270.  /*  2090 */  1161, 1161, 1161, 1161, 1161, 1161, 1161, 1161, 1161, 1161,

  149271.  /*  2100 */  1161, 1161, 1161, 1161, 1161, 1161, 1161, 1161, 1161, 1161,

  149272.  /*  2110 */  1161, 1161, 1161,  384, 1161, 1161, 1161, 1161,  288,  525,

  149273.  /*  2120 */  1161, 1161, 1161, 1161, 1161, 1161, 1161, 1161, 1161, 1161,

  149274.  /*  2130 */  1161, 1161, 1161, 1161, 1161, 1161, 1161, 1161, 1161, 1161,

  149275.  /*  2140 */  1161,  422,

  149276. };

  149277. static const YYCODETYPE yy_lookahead[] = {

  149278.  /*     0 */   260,  261,  262,  260,  261,  262,  176,  177,  178,  179,

  149279.  /*    10 */   180,  181,  184,  206,  209,  184,  186,  206,  188,   19,

  149280.  /*    20 */   179,  281,  181,  213,  214,  195,  206,  186,  195,  188,

  149281.  /*    30 */   195,   31,  222,  184,  206,  207,  195,  206,  207,   39,

  149282.  /*    40 */    24,  209,  184,   43,   44,   45,   46,   47,   48,   49,

  149283.  /*    50 */    50,   51,   52,   53,   54,   55,   56,   57,  228,  229,

  149284.  /*    60 */   184,  228,  229,  228,  229,  260,  261,  262,  192,  228,

  149285.  /*    70 */   229,  241,  196,  242,  241,   59,  241,  205,  245,  246,

  149286.  /*    80 */   184,   22,  241,   24,  254,  213,   54,   55,   56,   57,

  149287.  /*    90 */    58,  256,  260,  261,  262,  254,   96,   97,   98,   99,

  149288.  /*   100 */   100,  101,  102,  103,  104,  105,  106,  100,  101,  102,

  149289.  /*   110 */   103,  104,  105,  106,  284,  203,   19,  221,   59,  102,

  149290.  /*   120 */   103,  104,  105,  106,   59,  284,  110,  269,   96,   97,

  149291.  /*   130 */    98,   99,  100,  101,  102,  103,  104,  105,  106,   94,

  149292.  /*   140 */    43,   44,   45,   46,   47,   48,   49,   50,   51,   52,

  149293.  /*   150 */    53,   54,   55,   56,   57,  110,  184,  106,   73,  114,

  149294.  /*   160 */   178,  179,  180,  181,  219,  184,   81,   22,  186,  110,

  149295.  /*   170 */   188,  121,  122,  195,  109,  110,  111,  195,  206,  207,

  149296.  /*   180 */    83,  184,   85,   54,   55,   56,   57,  206,  207,  277,

  149297.  /*   190 */   145,  146,  147,   96,   97,   98,   99,  100,  101,  102,

  149298.  /*   200 */   103,  104,  105,  106,   59,  120,  228,  229,  143,  184,

  149299.  /*   210 */   228,  229,  184,   19,  242,  203,  131,  132,  221,  241,

  149300.  /*   220 */    26,  184,  184,  241,  196,   96,   97,   98,   99,  100,

  149301.  /*   230 */   101,  102,  103,  104,  105,  106,  254,   43,   44,   45,

  149302.  /*   240 */    46,   47,   48,   49,   50,   51,   52,   53,   54,   55,

  149303.  /*   250 */    56,   57,  184,  184,  109,  110,  111,  105,  106,  184,

  149304.  /*   260 */   200,  201,  202,   69,  184,  227,  284,   96,   97,   98,

  149305.  /*   270 */    99,  100,  101,  102,  103,  104,  105,  106,  297,  298,

  149306.  /*   280 */   255,  206,  207,   19,  272,   59,  206,  207,  184,  277,

  149307.  /*   290 */    96,   97,   98,   99,  100,  101,  102,  103,  104,  105,

  149308.  /*   300 */   106,  184,  259,   19,  184,  100,  101,   43,   44,   45,

  149309.  /*   310 */    46,   47,   48,   49,   50,   51,   52,   53,   54,   55,

  149310.  /*   320 */    56,   57,  242,  206,  207,  184,  100,  101,  138,  292,

  149311.  /*   330 */   293,   67,   76,  296,  108,  109,  110,  111,  295,  113,

  149312.  /*   340 */    84,   59,   86,   22,   26,   89,  156,  121,  224,  225,

  149313.  /*   350 */   145,   19,  147,   59,   72,  256,   24,  184,  290,  291,

  149314.  /*   360 */    96,   97,   98,   99,  100,  101,  102,  103,  104,  105,

  149315.  /*   370 */   106,  145,  297,  147,  299,   43,   44,   45,   46,   47,

  149316.  /*   380 */    48,   49,   50,   51,   52,   53,   54,   55,   56,   57,

  149317.  /*   390 */   106,  109,  110,  111,  138,  184,  112,  113,  114,  115,

  149318.  /*   400 */   116,  117,  118,  109,  110,  111,  112,   59,  124,  115,

  149319.  /*   410 */   116,  117,  292,  293,  297,  298,  296,  206,  207,  125,

  149320.  /*   420 */    72,  100,  101,  184,   46,   47,   48,   49,   96,   97,

  149321.  /*   430 */    98,   99,  100,  101,  102,  103,  104,  105,  106,   59,

  149322.  /*   440 */   200,  201,  202,  184,   59,  206,  207,   46,   19,  131,

  149323.  /*   450 */   132,  278,   23,  242,  184,  184,   76,  109,  110,  111,

  149324.  /*   460 */   224,  225,  251,   81,   84,  184,   86,   22,   23,   89,

  149325.  /*   470 */   184,   26,   43,   44,   45,   46,   47,   48,   49,   50,

  149326.  /*   480 */    51,   52,   53,   54,   55,   56,   57,  102,  184,  109,

  149327.  /*   490 */   110,  111,  114,  184,  109,  110,  111,  184,  227,  184,

  149328.  /*   500 */   230,  184,   22,  264,  195,   59,   22,  184,  195,  108,

  149329.  /*   510 */   206,  207,   59,  131,  132,  206,  207,  184,  138,  206,

  149330.  /*   520 */   207,  206,  207,  206,  207,   96,   97,   98,   99,  100,

  149331.  /*   530 */   101,  102,  103,  104,  105,  106,  255,  228,  229,   59,

  149332.  /*   540 */    95,  228,  229,   59,  184,   19,  242,   94,  184,   23,

  149333.  /*   550 */   241,  242,  184,  282,  241,  242,  110,  242,  184,  242,

  149334.  /*   560 */   251,   59,  109,  110,  196,  184,  251,  114,  251,   43,

  149335.  /*   570 */    44,   45,   46,   47,   48,   49,   50,   51,   52,   53,

  149336.  /*   580 */    54,   55,   56,   57,  259,  217,   12,  219,  255,  109,

  149337.  /*   590 */   110,  111,  203,  109,  110,  111,  184,   22,  145,  146,

  149338.  /*   600 */   147,   27,  112,   22,  230,  115,  116,  117,  227,   19,

  149339.  /*   610 */    59,  109,  110,  111,  291,  125,   42,   35,  206,  207,

  149340.  /*   620 */   295,  184,   96,   97,   98,   99,  100,  101,  102,  103,

  149341.  /*   630 */   104,  105,  106,   26,   59,  233,   46,   63,  136,  184,

  149342.  /*   640 */    59,  184,   19,  206,  207,  243,   23,   73,   66,  260,

  149343.  /*   650 */   261,  262,   59,  184,  242,  195,   74,  220,  184,  184,

  149344.  /*   660 */   109,  110,  111,  206,  207,  184,   43,   44,   45,   46,

  149345.  /*   670 */    47,   48,   49,   50,   51,   52,   53,   54,   55,   56,

  149346.  /*   680 */    57,  206,  207,   76,  109,  110,  111,  136,  228,  229,

  149347.  /*   690 */   109,  110,  111,   86,  184,  220,   89,   21,  108,  230,

  149348.  /*   700 */   184,  241,  109,  110,  111,  123,  184,  127,  184,  129,

  149349.  /*   710 */   130,  184,  195,  184,  124,  184,  198,  199,  184,   96,

  149350.  /*   720 */    97,   98,   99,  100,  101,  102,  103,  104,  105,  106,

  149351.  /*   730 */   206,  207,   11,  206,  207,  206,  207,  206,  207,   19,

  149352.  /*   740 */   206,  207,  184,   23,  220,  228,  229,  220,   81,  220,

  149353.  /*   750 */   195,  220,  287,  288,  220,  195,   80,  195,  241,  201,

  149354.  /*   760 */   202,  184,   73,   43,   44,   45,   46,   47,   48,   49,

  149355.  /*   770 */    50,   51,   52,   53,   54,   55,   56,   57,  201,  202,

  149356.  /*   780 */   113,  195,  184,  228,  229,  120,  121,  122,  228,  229,

  149357.  /*   790 */   228,  229,  116,   16,   23,  184,  241,   26,  131,  132,

  149358.  /*   800 */   278,  241,   19,  241,   22,   23,  184,  189,   26,  120,

  149359.  /*   810 */   121,  122,  184,   26,  228,  229,   96,   97,   98,   99,

  149360.  /*   820 */   100,  101,  102,  103,  104,  105,  106,  241,  270,  153,

  149361.  /*   830 */    66,  228,  229,  229,  206,  207,   19,  184,  228,  229,

  149362.  /*   840 */    23,   16,  121,  122,  241,  241,   82,  270,   29,  227,

  149363.  /*   850 */   252,  241,   33,   19,   77,   91,   79,  184,   22,   23,

  149364.  /*   860 */    43,   44,   45,   46,   47,   48,   49,   50,   51,   52,

  149365.  /*   870 */    53,   54,   55,   56,   57,   12,  184,   95,  184,  206,

  149366.  /*   880 */   207,   76,  111,  184,   65,  267,  184,  184,  184,  271,

  149367.  /*   890 */    27,   86,  109,  184,   89,  120,  121,  122,  206,  207,

  149368.  /*   900 */   206,  207,   77,  139,   79,   42,  184,  136,  206,  207,

  149369.  /*   910 */   206,  207,  184,   96,   97,   98,   99,  100,  101,  102,

  149370.  /*   920 */   103,  104,  105,  106,  184,  138,   63,  184,  206,  207,

  149371.  /*   930 */   153,   95,  184,   19,  206,  207,  227,   23,    7,    8,

  149372.  /*   940 */     9,  293,  293,  109,  296,  296,  206,  207,  215,  206,

  149373.  /*   950 */   207,  184,  253,   19,  206,  207,  253,   43,   44,   45,

  149374.  /*   960 */    46,   47,   48,   49,   50,   51,   52,   53,   54,   55,

  149375.  /*   970 */    56,   57,  184,  206,  207,  184,  184,   43,   44,   45,

  149376.  /*   980 */    46,   47,   48,   49,   50,   51,   52,   53,   54,   55,

  149377.  /*   990 */    56,   57,  184,   22,   23,  184,   59,  206,  207,  184,

  149378.  /*  1000 */   184,  238,  184,  240,  184,   22,  184,  184,  157,  158,

  149379.  /*  1010 */    96,   97,   98,   99,  100,  101,  102,  103,  104,  105,

  149380.  /*  1020 */   106,  206,  207,  184,  206,  207,  206,  207,  206,  207,

  149381.  /*  1030 */    96,   97,   98,   99,  100,  101,  102,  103,  104,  105,

  149382.  /*  1040 */   106,  184,   59,  227,  252,  184,  293,  110,  184,  296,

  149383.  /*  1050 */   184,  184,  184,  230,  184,  184,  184,   15,  184,  184,

  149384.  /*  1060 */   184,  253,  184,  206,  207,  184,   95,  206,  207,  102,

  149385.  /*  1070 */   206,  207,  206,  207,  206,  207,  206,  207,  206,  207,

  149386.  /*  1080 */   206,  207,  206,  207,  184,  151,  184,  206,  207,  278,

  149387.  /*  1090 */   184,  252,  184,  110,  184,  128,  184,  198,  199,  184,

  149388.  /*  1100 */   133,  184,   60,   26,  184,   19,  206,  207,  206,  207,

  149389.  /*  1110 */   131,  132,  206,  207,  206,  207,  206,  207,  206,  207,

  149390.  /*  1120 */   253,  206,  207,  206,  207,   19,  206,  207,  253,   43,

  149391.  /*  1130 */    44,   45,   46,   47,   48,   49,   50,   51,   52,   53,

  149392.  /*  1140 */    54,   55,   56,   57,  184,   26,  184,   26,  184,   43,

  149393.  /*  1150 */    44,   45,   46,   47,   48,   49,   50,   51,   52,   53,

  149394.  /*  1160 */    54,   55,   56,   57,  285,  286,  206,  207,  206,  207,

  149395.  /*  1170 */   206,  207,  184,   31,  184,  293,  184,  293,  296,  184,

  149396.  /*  1180 */   296,   39,   96,   97,   98,   99,  100,  101,  102,  103,

  149397.  /*  1190 */   104,  105,  106,  184,  206,  207,  206,  207,  206,  207,

  149398.  /*  1200 */   184,   22,   96,   97,   98,   99,  100,  101,  102,  103,

  149399.  /*  1210 */   104,  105,  106,  184,  245,  246,  184,   26,   23,  142,

  149400.  /*  1220 */   128,   26,  206,  207,  150,  133,  152,   22,   22,   24,

  149401.  /*  1230 */   111,   23,   53,  184,   26,  206,  207,  151,  206,  207,

  149402.  /*  1240 */   119,   24,  122,   23,   23,   23,   26,   26,   26,   23,

  149403.  /*  1250 */    23,   23,   26,   26,   26,  136,   23,   19,   22,   26,

  149404.  /*  1260 */   113,  114,   24,  114,  144,  184,   59,   61,    7,    8,

  149405.  /*  1270 */    59,   23,   23,  124,   26,   26,   23,   19,  145,   26,

  149406.  /*  1280 */   147,   43,   44,   45,   46,   47,   48,   49,   50,   51,

  149407.  /*  1290 */    52,   53,   54,   55,   56,   57,  145,   23,  147,  184,

  149408.  /*  1300 */    26,   43,   44,   45,   46,   47,   48,   49,   50,   51,

  149409.  /*  1310 */    52,   53,   54,   55,   56,   57,   23,  110,  184,   26,

  149410.  /*  1320 */   184,  110,  184,  184,  184,  215,  135,  215,  184,  184,

  149411.  /*  1330 */   184,  247,  184,  244,   96,   97,   98,   99,  100,  101,

  149412.  /*  1340 */   102,  103,  104,  105,  106,  184,  184,  184,  301,  184,

  149413.  /*  1350 */   184,  134,  225,  184,   96,   97,   98,   99,  100,  101,

  149414.  /*  1360 */   102,  103,  104,  105,  106,  184,  184,  184,  184,  184,

  149415.  /*  1370 */   134,  184,  274,  273,   19,  244,  244,  204,  182,  244,

  149416.  /*  1380 */   283,  231,  279,  279,  232,  244,  210,  209,  235,  235,

  149417.  /*  1390 */   235,  248,  218,  234,   19,  209,  238,  209,  238,   44,

  149418.  /*  1400 */    45,   46,   47,   48,   49,   50,   51,   52,   53,   54,

  149419.  /*  1410 */    55,   56,   57,  214,   60,  248,  248,  187,  134,   38,

  149420.  /*  1420 */    45,   46,   47,   48,   49,   50,   51,   52,   53,   54,

  149421.  /*  1430 */    55,   56,   57,  232,  191,  191,  266,  280,  191,  283,

  149422.  /*  1440 */   143,  269,  108,   22,  280,   19,   20,  258,   22,  257,

  149423.  /*  1450 */    43,   96,   97,   98,   99,  100,  101,  102,  103,  104,

  149424.  /*  1460 */   105,  106,   36,  223,  142,   18,  235,  226,  226,  191,

  149425.  /*  1470 */    18,   96,   97,   98,   99,  100,  101,  102,  103,  104,

  149426.  /*  1480 */   105,  106,  226,  226,  190,   59,  235,  235,  223,  223,

  149427.  /*  1490 */   258,  257,  191,  190,  235,  150,   62,   71,  191,  276,

  149428.  /*  1500 */   275,   19,   20,  190,   22,   22,  211,   81,  191,  190,

  149429.  /*  1510 */   211,  191,  108,  190,  208,   64,  208,  208,   36,  119,

  149430.  /*  1520 */    94,  216,  211,  208,  210,  106,  100,  101,  216,  208,

  149431.  /*  1530 */    48,  268,  208,  107,  208,  109,  110,  111,  211,  268,

  149432.  /*  1540 */   114,   59,  211,  137,  108,   88,  250,  249,  191,  141,

  149433.  /*  1550 */   250,  249,  138,   71,  250,  300,   22,  131,  132,  249,

  149434.  /*  1560 */   300,  191,  150,  238,   82,  140,  250,  249,  239,   87,

  149435.  /*  1570 */   139,  145,  146,  147,  148,  149,   94,  239,  237,  236,

  149436.  /*  1580 */    25,  235,  100,  101,  194,   26,  193,   13,  185,  107,

  149437.  /*  1590 */   185,  109,  110,  111,    6,  263,  114,  203,  265,  183,

  149438.  /*  1600 */   183,  183,  203,  212,  203,  203,  197,  197,  212,    4,

  149439.  /*  1610 */     3,   22,  197,  155,   15,  204,  203,  289,   93,  289,

  149440.  /*  1620 */    16,  286,  132,   23,  204,   23,  123,  145,  146,  147,

  149441.  /*  1630 */   148,  149,    0,    1,    2,  143,   24,    5,   20,  135,

  149442.  /*  1640 */    16,    1,   10,   11,   12,   13,   14,  137,  135,   17,

  149443.  /*  1650 */   144,  123,   19,   20,   61,   22,   37,  143,  123,   53,

  149444.  /*  1660 */   109,   53,   30,   53,   32,   34,   53,  134,    1,   36,

  149445.  /*  1670 */     5,   22,   40,  108,  153,   41,   26,   68,   75,   68,

  149446.  /*  1680 */   134,  108,   24,   20,  124,   19,  118,   67,   67,   28,

  149447.  /*  1690 */    22,   22,   59,   22,   67,   23,   22,   22,  142,   37,

  149448.  /*  1700 */    23,   22,   70,   23,   71,  157,   23,   23,   26,   23,

  149449.  /*  1710 */    78,   22,   24,   81,   23,   82,   22,   24,  134,   23,

  149450.  /*  1720 */    87,   23,   19,   20,   92,   22,  109,   94,   22,   34,

  149451.  /*  1730 */   136,   26,   85,  100,  101,   34,   34,   83,   34,   36,

  149452.  /*  1740 */   107,   34,  109,  110,  111,   75,   90,  114,   75,   34,

  149453.  /*  1750 */    23,   22,   44,   34,   24,   23,   22,   26,  126,   26,

  149454.  /*  1760 */    23,   23,   59,  131,  132,   23,   23,   26,   23,   11,

  149455.  /*  1770 */    22,   22,   26,   23,   71,   23,   22,   22,  145,  146,

  149456.  /*  1780 */   147,  148,  149,  128,   23,   82,  154,  134,   15,    1,

  149457.  /*  1790 */    87,  134,  302,  134,  134,  302,  302,   94,  302,  302,

  149458.  /*  1800 */   302,  302,  302,  100,  101,  302,  302,  302,  302,  302,

  149459.  /*  1810 */   107,  302,  109,  110,  111,    1,    2,  114,  302,    5,

  149460.  /*  1820 */   302,  302,  302,  302,   10,   11,   12,   13,   14,  302,

  149461.  /*  1830 */   302,   17,  302,  302,  302,  302,   19,   20,  302,   22,

  149462.  /*  1840 */   302,  302,  302,  302,   30,  302,   32,  302,  145,  146,

  149463.  /*  1850 */   147,  148,  149,   36,   40,  302,  302,  302,  302,  302,

  149464.  /*  1860 */   302,  302,  302,  302,  302,  302,  302,  302,  302,  302,

  149465.  /*  1870 */   302,  302,  302,  302,  302,  302,   59,  302,  302,  302,

  149466.  /*  1880 */   302,  302,  302,  302,   70,  302,  302,  302,   71,  302,

  149467.  /*  1890 */   302,  302,   78,  302,  302,   81,   19,   20,  302,   22,

  149468.  /*  1900 */   302,  302,  302,  302,  302,  302,   92,  302,  302,  302,

  149469.  /*  1910 */   302,   94,  302,   36,  302,  302,  302,  100,  101,  102,

  149470.  /*  1920 */   302,  302,  302,  302,  107,  302,  109,  110,  111,  302,

  149471.  /*  1930 */   302,  114,  302,  302,  302,  302,   59,  302,  302,  302,

  149472.  /*  1940 */   126,  302,  302,  302,  302,  131,  132,  302,   71,  302,

  149473.  /*  1950 */   302,  302,  302,  302,  302,  302,   19,   20,  302,   22,

  149474.  /*  1960 */   302,  302,  145,  146,  147,  148,  149,  302,  154,  302,

  149475.  /*  1970 */   302,   94,  302,   36,  302,  302,  302,  100,  101,  302,

  149476.  /*  1980 */   302,  302,  302,  302,  107,  302,  109,  110,  111,  302,

  149477.  /*  1990 */   302,  114,    5,  302,  302,  302,   59,   10,   11,   12,

  149478.  /*  2000 */    13,   14,  302,  302,   17,  302,  302,  302,   71,  302,

  149479.  /*  2010 */   302,  302,  302,  302,  302,  302,  302,   30,  302,   32,

  149480.  /*  2020 */   302,  302,  145,  146,  147,  148,  149,   40,  302,  302,

  149481.  /*  2030 */   302,   94,  302,  302,  302,  302,  302,  100,  101,  302,

  149482.  /*  2040 */   302,  302,  302,  302,  107,  302,  109,  110,  111,  302,

  149483.  /*  2050 */   302,  114,  302,  302,  302,  302,  302,   70,  302,  302,

  149484.  /*  2060 */   302,  302,  302,  302,  302,   78,  302,  302,   81,  302,

  149485.  /*  2070 */   302,  302,  302,  302,  302,  302,  302,  302,  302,   92,

  149486.  /*  2080 */   302,  302,  145,  146,  147,  148,  149,  302,  302,  302,

  149487.  /*  2090 */   302,  302,  302,  302,  302,  302,  302,  302,  302,  302,

  149488.  /*  2100 */   302,  302,  302,  302,  302,  302,  302,  302,  302,  302,

  149489.  /*  2110 */   302,  302,  302,  126,  302,  302,  302,  302,  131,  132,

  149490.  /*  2120 */   302,  302,  302,  302,  302,  302,  302,  302,  302,  302,

  149491.  /*  2130 */   302,  302,  302,  302,  302,  302,  302,  302,  302,  302,

  149492.  /*  2140 */   302,  154,  302,  302,  302,  302,  302,  302,  302,  302,

  149493.  /*  2150 */   302,  302,  302,  302,  302,  302,  302,  302,  302,  302,

  149494.  /*  2160 */   302,  302,  302,  302,  302,  302,  302,  302,  302,

  149495. };

  149496. #define YY_SHIFT_COUNT    (539)

  149497. #define YY_SHIFT_MIN      (0)

  149498. #define YY_SHIFT_MAX      (1987)

  149499. static const unsigned short int yy_shift_ofst[] = {

  149500.  /*     0 */  1814, 1632, 1987, 1426, 1426,  382, 1482, 1633, 1703, 1877,

  149501.  /*    10 */  1877, 1877,   85,    0,    0,  264, 1106, 1877, 1877, 1877,

  149502.  /*    20 */  1877, 1877, 1877, 1877, 1877, 1877, 1877, 1877, 1877, 1877,

  149503.  /*    30 */   226,  226,  380,  380,  294,  667,  382,  382,  382,  382,

  149504.  /*    40 */   382,  382,   97,  194,  332,  429,  526,  623,  720,  817,

  149505.  /*    50 */   914,  934, 1086, 1238, 1106, 1106, 1106, 1106, 1106, 1106,

  149506.  /*    60 */  1106, 1106, 1106, 1106, 1106, 1106, 1106, 1106, 1106, 1106,

  149507.  /*    70 */  1106, 1106, 1258, 1106, 1355, 1375, 1375, 1817, 1877, 1877,

  149508.  /*    80 */  1877, 1877, 1877, 1877, 1877, 1877, 1877, 1877, 1877, 1877,

  149509.  /*    90 */  1877, 1877, 1877, 1877, 1877, 1877, 1877, 1877, 1877, 1877,

  149510.  /*   100 */  1877, 1877, 1877, 1877, 1877, 1877, 1877, 1877, 1877, 1877,

  149511.  /*   110 */  1937, 1877, 1877, 1877, 1877, 1877, 1877, 1877, 1877, 1877,

  149512.  /*   120 */  1877, 1877, 1877, 1877,   32,  129,  129,  129,  129,  129,

  149513.  /*   130 */   171,    7,   17,  593,  676,  590,  593,  205,  205,  593,

  149514.  /*   140 */   318,  318,  318,  318,   50,  152,   51, 2142, 2142,  284,

  149515.  /*   150 */   284,  284,   65,  145,  282,  145,  145,  574,  574,  256,

  149516.  /*   160 */   348,  445,  782,  593,  593,  593,  593,  593,  593,  593,

  149517.  /*   170 */   593,  593,  593,  593,  593,  593,  593,  593,  593,  593,

  149518.  /*   180 */   593,  593,  593,  593,  607,  607,  593,  721,  805,  805,

  149519.  /*   190 */   446,  851,  851,  446,  190,  979, 2142, 2142, 2142,  453,

  149520.  /*   200 */    45,   45,  480,  490,  484,  385,  575,  502,  551,  581,

  149521.  /*   210 */   593,  593,  593,  593,  593,  593,  593,  593,  593,  689,

  149522.  /*   220 */   593,  593,  593,  593,  593,  593,  593,  593,  593,  593,

  149523.  /*   230 */   593,  593,  582,  582,  582,  593,  593,  593,  593,  771,

  149524.  /*   240 */   593,  593,  593,   59,  764,  593,  593,  863,  593,  593,

  149525.  /*   250 */   593,  593,  593,  593,  593,  593,  665,  819,  580,   16,

  149526.  /*   260 */    16,   16,   16, 1119,  580,  580,  967,  321,  931, 1042,

  149527.  /*   270 */  1077,  783,  783,  834, 1077, 1077,  834, 1121, 1195,  401,

  149528.  /*   280 */  1142, 1142, 1142,  783,  787,  787, 1074, 1191, 1092, 1205,

  149529.  /*   290 */  1354, 1284, 1284, 1381, 1381, 1284, 1297, 1334, 1421, 1407,

  149530.  /*   300 */  1322, 1447, 1447, 1447, 1447, 1284, 1452, 1322, 1322, 1334,

  149531.  /*   310 */  1421, 1407, 1407, 1322, 1284, 1452, 1345, 1434, 1284, 1452,

  149532.  /*   320 */  1483, 1284, 1452, 1284, 1452, 1483, 1404, 1404, 1404, 1451,

  149533.  /*   330 */  1483, 1404, 1400, 1404, 1451, 1404, 1404, 1483, 1419, 1419,

  149534.  /*   340 */  1483, 1406, 1436, 1406, 1436, 1406, 1436, 1406, 1436, 1284,

  149535.  /*   350 */  1457, 1457, 1408, 1414, 1534, 1284, 1412, 1408, 1425, 1431,

  149536.  /*   360 */  1322, 1555, 1559, 1574, 1574, 1588, 1588, 1588, 2142, 2142,

  149537.  /*   370 */  2142, 2142, 2142, 2142, 2142, 2142, 2142, 2142, 2142, 2142,

  149538.  /*   380 */  2142, 2142, 2142,  378,  777,  836,  971,  825,  775,  983,

  149539.  /*   390 */  1208, 1179, 1217, 1120, 1220, 1206, 1221, 1222, 1226, 1227,

  149540.  /*   400 */  1228, 1233,  937, 1147, 1261, 1149, 1207, 1248, 1249, 1253,

  149541.  /*   410 */  1133, 1151, 1274, 1293, 1211, 1236, 1605, 1607, 1589, 1458,

  149542.  /*   420 */  1599, 1525, 1604, 1600, 1602, 1490, 1492, 1503, 1612, 1504,

  149543.  /*   430 */  1618, 1510, 1624, 1640, 1513, 1506, 1528, 1593, 1619, 1514,

  149544.  /*   440 */  1606, 1608, 1610, 1613, 1535, 1551, 1631, 1533, 1667, 1665,

  149545.  /*   450 */  1649, 1565, 1521, 1609, 1650, 1611, 1603, 1634, 1546, 1573,

  149546.  /*   460 */  1658, 1663, 1666, 1560, 1568, 1668, 1620, 1669, 1671, 1672,

  149547.  /*   470 */  1674, 1621, 1661, 1675, 1627, 1662, 1677, 1556, 1679, 1680,

  149548.  /*   480 */  1548, 1683, 1684, 1682, 1686, 1689, 1688, 1691, 1694, 1693,

  149549.  /*   490 */  1584, 1696, 1698, 1617, 1695, 1706, 1594, 1705, 1701, 1702,

  149550.  /*   500 */  1704, 1707, 1647, 1670, 1654, 1708, 1673, 1656, 1715, 1727,

  149551.  /*   510 */  1729, 1730, 1731, 1733, 1719, 1732, 1705, 1737, 1738, 1742,

  149552.  /*   520 */  1743, 1741, 1745, 1734, 1758, 1748, 1749, 1750, 1752, 1754,

  149553.  /*   530 */  1755, 1746, 1655, 1653, 1657, 1659, 1660, 1761, 1773, 1788,

  149554. };

  149555. #define YY_REDUCE_COUNT (382)

  149556. #define YY_REDUCE_MIN   (-260)

  149557. #define YY_REDUCE_MAX   (1420)

  149558. static const short yy_reduce_ofst[] = {

  149559.  /*     0 */  -170,  -18, -159,  309,  313, -167,  -19,   75,  117,  211,

  149560.  /*    10 */   315,  317, -165, -195, -168, -260,  389,  437,  475,  524,

  149561.  /*    20 */   527, -169,  529,  531,  -28,   80,  534,  239,  304,  412,

  149562.  /*    30 */   558,  577,   37,  120,  368,  -22,  460,  517,  555,  560,

  149563.  /*    40 */   562,  586, -257, -257, -257, -257, -257, -257, -257, -257,

  149564.  /*    50 */  -257, -257, -257, -257, -257, -257, -257, -257, -257, -257,

  149565.  /*    60 */  -257, -257, -257, -257, -257, -257, -257, -257, -257, -257,

  149566.  /*    70 */  -257, -257, -257, -257, -257, -257, -257, -172,  457,  628,

  149567.  /*    80 */   673,  692,  694,  702,  704,  722,  728,  740,  743,  748,

  149568.  /*    90 */   767,  791,  815,  818,  820,  822,  857,  861,  864,  866,

  149569.  /*   100 */   868,  870,  872,  874,  876,  881,  900,  902,  906,  908,

  149570.  /*   110 */   910,  912,  915,  917,  920,  960,  962,  964,  988,  990,

  149571.  /*   120 */   992, 1016, 1029, 1032, -257, -257, -257, -257, -257, -257,

  149572.  /*   130 */  -257, -257, -257,  271,  618, -190,   68,   60,  240, -124,

  149573.  /*   140 */   603,  610,  603,  610,   12, -257, -257, -257, -257, -128,

  149574.  /*   150 */  -128, -128, -142,   25,  270,  281,  333,  124,  236,  648,

  149575.  /*   160 */   374,  465,  465,   28,  598,  792,  839,  469,   38,  381,

  149576.  /*   170 */   622,  709,  173,  699,  522,  703,  808,  811,  867,  816,

  149577.  /*   180 */  -104,  823,   -3,  875,  649,  753,  323,  -88,  882,  884,

  149578.  /*   190 */   518,   43,  325,  899,  763,  604,  879,  969,  402, -193,

  149579.  /*   200 */  -189, -180, -151,  -55,   69,  104,  141,  259,  286,  360,

  149580.  /*   210 */   364,  455,  474,  481,  510,  516,  611,  653,  788,   99,

  149581.  /*   220 */   871,  878,  995, 1009, 1049, 1081, 1115, 1134, 1136, 1138,

  149582.  /*   230 */  1139, 1140,  733, 1110, 1112, 1144, 1145, 1146, 1148, 1084,

  149583.  /*   240 */  1161, 1162, 1163, 1089, 1047, 1165, 1166, 1127, 1169,  104,

  149584.  /*   250 */  1181, 1182, 1183, 1184, 1185, 1187, 1098, 1100, 1150, 1131,

  149585.  /*   260 */  1132, 1135, 1141, 1084, 1150, 1150, 1152, 1173, 1196, 1097,

  149586.  /*   270 */  1153, 1143, 1167, 1103, 1154, 1155, 1104, 1176, 1174, 1199,

  149587.  /*   280 */  1178, 1186, 1188, 1168, 1158, 1160, 1170, 1159, 1201, 1230,

  149588.  /*   290 */  1156, 1243, 1244, 1157, 1164, 1247, 1172, 1189, 1192, 1240,

  149589.  /*   300 */  1231, 1241, 1242, 1256, 1257, 1278, 1294, 1251, 1252, 1232,

  149590.  /*   310 */  1234, 1265, 1266, 1259, 1301, 1303, 1223, 1225, 1307, 1313,

  149591.  /*   320 */  1295, 1317, 1319, 1320, 1323, 1299, 1306, 1308, 1309, 1305,

  149592.  /*   330 */  1311, 1315, 1314, 1321, 1312, 1324, 1326, 1327, 1263, 1271,

  149593.  /*   340 */  1331, 1296, 1298, 1300, 1302, 1304, 1310, 1316, 1318, 1357,

  149594.  /*   350 */  1255, 1260, 1329, 1325, 1332, 1370, 1333, 1338, 1341, 1343,

  149595.  /*   360 */  1346, 1390, 1393, 1403, 1405, 1416, 1417, 1418, 1328, 1330,

  149596.  /*   370 */  1335, 1409, 1394, 1399, 1401, 1402, 1410, 1391, 1396, 1411,

  149597.  /*   380 */  1420, 1413, 1415,

  149598. };

  149599. static const YYACTIONTYPE yy_default[] = {

  149600.  /*     0 */  1537, 1537, 1537, 1377, 1159, 1266, 1159, 1159, 1159, 1377,

  149601.  /*    10 */  1377, 1377, 1159, 1296, 1296, 1430, 1190, 1159, 1159, 1159,

  149602.  /*    20 */  1159, 1159, 1159, 1159, 1159, 1159, 1159, 1376, 1159, 1159,

  149603.  /*    30 */  1159, 1159, 1460, 1460, 1159, 1159, 1159, 1159, 1159, 1159,

  149604.  /*    40 */  1159, 1159, 1159, 1302, 1159, 1159, 1159, 1159, 1159, 1378,

  149605.  /*    50 */  1379, 1159, 1159, 1159, 1429, 1431, 1394, 1312, 1311, 1310,

  149606.  /*    60 */  1309, 1412, 1283, 1307, 1300, 1304, 1372, 1373, 1371, 1375,

  149607.  /*    70 */  1379, 1378, 1159, 1303, 1343, 1357, 1342, 1159, 1159, 1159,

  149608.  /*    80 */  1159, 1159, 1159, 1159, 1159, 1159, 1159, 1159, 1159, 1159,

  149609.  /*    90 */  1159, 1159, 1159, 1159, 1159, 1159, 1159, 1159, 1159, 1159,

  149610.  /*   100 */  1159, 1159, 1159, 1159, 1159, 1159, 1159, 1159, 1159, 1159,

  149611.  /*   110 */  1159, 1159, 1159, 1159, 1159, 1159, 1159, 1159, 1159, 1159,

  149612.  /*   120 */  1159, 1159, 1159, 1159, 1351, 1356, 1362, 1355, 1352, 1345,

  149613.  /*   130 */  1344, 1346, 1347, 1159, 1180, 1230, 1159, 1159, 1159, 1159,

  149614.  /*   140 */  1448, 1447, 1159, 1159, 1190, 1348, 1349, 1359, 1358, 1437,

  149615.  /*   150 */  1493, 1492, 1395, 1159, 1159, 1159, 1159, 1159, 1159, 1460,

  149616.  /*   160 */  1159, 1159, 1159, 1159, 1159, 1159, 1159, 1159, 1159, 1159,

  149617.  /*   170 */  1159, 1159, 1159, 1159, 1159, 1159, 1159, 1159, 1159, 1159,

  149618.  /*   180 */  1159, 1159, 1159, 1159, 1460, 1460, 1159, 1190, 1460, 1460,

  149619.  /*   190 */  1186, 1337, 1336, 1186, 1290, 1159, 1443, 1266, 1257, 1159,

  149620.  /*   200 */  1159, 1159, 1159, 1159, 1159, 1159, 1159, 1159, 1159, 1159,

  149621.  /*   210 */  1159, 1159, 1159, 1434, 1432, 1159, 1159, 1159, 1159, 1159,

  149622.  /*   220 */  1159, 1159, 1159, 1159, 1159, 1159, 1159, 1159, 1159, 1159,

  149623.  /*   230 */  1159, 1159, 1159, 1159, 1159, 1159, 1159, 1159, 1159, 1159,

  149624.  /*   240 */  1159, 1159, 1159, 1262, 1159, 1159, 1159, 1159, 1159, 1159,

  149625.  /*   250 */  1159, 1159, 1159, 1159, 1159, 1487, 1159, 1407, 1244, 1262,

  149626.  /*   260 */  1262, 1262, 1262, 1264, 1245, 1243, 1256, 1191, 1166, 1529,

  149627.  /*   270 */  1306, 1285, 1285, 1526, 1306, 1306, 1526, 1205, 1507, 1202,

  149628.  /*   280 */  1296, 1296, 1296, 1285, 1290, 1290, 1374, 1263, 1256, 1159,

  149629.  /*   290 */  1529, 1271, 1271, 1528, 1528, 1271, 1395, 1315, 1321, 1233,

  149630.  /*   300 */  1306, 1239, 1239, 1239, 1239, 1271, 1177, 1306, 1306, 1315,

  149631.  /*   310 */  1321, 1233, 1233, 1306, 1271, 1177, 1411, 1523, 1271, 1177,

  149632.  /*   320 */  1385, 1271, 1177, 1271, 1177, 1385, 1231, 1231, 1231, 1220,

  149633.  /*   330 */  1385, 1231, 1205, 1231, 1220, 1231, 1231, 1385, 1389, 1389,

  149634.  /*   340 */  1385, 1289, 1284, 1289, 1284, 1289, 1284, 1289, 1284, 1271,

  149635.  /*   350 */  1470, 1470, 1301, 1290, 1380, 1271, 1159, 1301, 1299, 1297,

  149636.  /*   360 */  1306, 1183, 1223, 1490, 1490, 1486, 1486, 1486, 1534, 1534,

  149637.  /*   370 */  1443, 1502, 1190, 1190, 1190, 1190, 1502, 1207, 1207, 1191,

  149638.  /*   380 */  1191, 1190, 1502, 1159, 1159, 1159, 1159, 1159, 1159, 1497,

  149639.  /*   390 */  1159, 1396, 1275, 1159, 1159, 1159, 1159, 1159, 1159, 1159,

  149640.  /*   400 */  1159, 1159, 1159, 1159, 1159, 1159, 1159, 1159, 1159, 1159,

  149641.  /*   410 */  1159, 1159, 1159, 1159, 1159, 1326, 1159, 1162, 1440, 1159,

  149642.  /*   420 */  1159, 1438, 1159, 1159, 1159, 1159, 1159, 1159, 1276, 1159,

  149643.  /*   430 */  1159, 1159, 1159, 1159, 1159, 1159, 1159, 1159, 1159, 1159,

  149644.  /*   440 */  1159, 1159, 1159, 1159, 1159, 1159, 1159, 1525, 1159, 1159,

  149645.  /*   450 */  1159, 1159, 1159, 1159, 1410, 1409, 1159, 1159, 1273, 1159,

  149646.  /*   460 */  1159, 1159, 1159, 1159, 1159, 1159, 1159, 1159, 1159, 1159,

  149647.  /*   470 */  1159, 1159, 1159, 1159, 1159, 1159, 1159, 1159, 1159, 1159,

  149648.  /*   480 */  1159, 1159, 1159, 1159, 1159, 1159, 1159, 1159, 1159, 1159,

  149649.  /*   490 */  1159, 1159, 1159, 1159, 1159, 1159, 1159, 1298, 1159, 1159,

  149650.  /*   500 */  1159, 1159, 1159, 1159, 1159, 1159, 1159, 1159, 1159, 1159,

  149651.  /*   510 */  1159, 1159, 1475, 1291, 1159, 1159, 1516, 1159, 1159, 1159,

  149652.  /*   520 */  1159, 1159, 1159, 1159, 1159, 1159, 1159, 1159, 1159, 1159,

  149653.  /*   530 */  1159, 1511, 1247, 1328, 1159, 1327, 1331, 1159, 1171, 1159,

  149654. };

  149655. /********** End of lemon-generated parsing tables *****************************/

  149656. 

  149657. /* The next table maps tokens (terminal symbols) into fallback tokens.  

  149658. ** If a construct like the following:

  149659. ** 

  149660. **      %fallback ID X Y Z.

  149661. **

  149662. ** appears in the grammar, then ID becomes a fallback token for X, Y,

  149663. ** and Z.  Whenever one of the tokens X, Y, or Z is input to the parser

  149664. ** but it does not parse, the type of the token is changed to ID and

  149665. ** the parse is retried before an error is thrown.

  149666. **

  149667. ** This feature can be used, for example, to cause some keywords in a language

  149668. ** to revert to identifiers if they keyword does not apply in the context where

  149669. ** it appears.

  149670. */

  149671. #ifdef YYFALLBACK

  149672. static const YYCODETYPE yyFallback[] = {

  149673.     0,  /*          $ => nothing */

  149674.     0,  /*       SEMI => nothing */

  149675.    59,  /*    EXPLAIN => ID */

  149676.    59,  /*      QUERY => ID */

  149677.    59,  /*       PLAN => ID */

  149678.    59,  /*      BEGIN => ID */

  149679.     0,  /* TRANSACTION => nothing */

  149680.    59,  /*   DEFERRED => ID */

  149681.    59,  /*  IMMEDIATE => ID */

  149682.    59,  /*  EXCLUSIVE => ID */

  149683.     0,  /*     COMMIT => nothing */

  149684.    59,  /*        END => ID */

  149685.    59,  /*   ROLLBACK => ID */

  149686.    59,  /*  SAVEPOINT => ID */

  149687.    59,  /*    RELEASE => ID */

  149688.     0,  /*         TO => nothing */

  149689.     0,  /*      TABLE => nothing */

  149690.     0,  /*     CREATE => nothing */

  149691.    59,  /*         IF => ID */

  149692.     0,  /*        NOT => nothing */

  149693.     0,  /*     EXISTS => nothing */

  149694.    59,  /*       TEMP => ID */

  149695.     0,  /*         LP => nothing */

  149696.     0,  /*         RP => nothing */

  149697.     0,  /*         AS => nothing */

  149698.    59,  /*    WITHOUT => ID */

  149699.     0,  /*      COMMA => nothing */

  149700.    59,  /*      ABORT => ID */

  149701.    59,  /*     ACTION => ID */

  149702.    59,  /*      AFTER => ID */

  149703.    59,  /*    ANALYZE => ID */

  149704.    59,  /*        ASC => ID */

  149705.    59,  /*     ATTACH => ID */

  149706.    59,  /*     BEFORE => ID */

  149707.    59,  /*         BY => ID */

  149708.    59,  /*    CASCADE => ID */

  149709.    59,  /*       CAST => ID */

  149710.    59,  /*   CONFLICT => ID */

  149711.    59,  /*   DATABASE => ID */

  149712.    59,  /*       DESC => ID */

  149713.    59,  /*     DETACH => ID */

  149714.    59,  /*       EACH => ID */

  149715.    59,  /*       FAIL => ID */

  149716.     0,  /*         OR => nothing */

  149717.     0,  /*        AND => nothing */

  149718.     0,  /*         IS => nothing */

  149719.    59,  /*      MATCH => ID */

  149720.    59,  /*    LIKE_KW => ID */

  149721.     0,  /*    BETWEEN => nothing */

  149722.     0,  /*         IN => nothing */

  149723.     0,  /*     ISNULL => nothing */

  149724.     0,  /*    NOTNULL => nothing */

  149725.     0,  /*         NE => nothing */

  149726.     0,  /*         EQ => nothing */

  149727.     0,  /*         GT => nothing */

  149728.     0,  /*         LE => nothing */

  149729.     0,  /*         LT => nothing */

  149730.     0,  /*         GE => nothing */

  149731.     0,  /*     ESCAPE => nothing */

  149732.     0,  /*         ID => nothing */

  149733.    59,  /*   COLUMNKW => ID */

  149734.    59,  /*         DO => ID */

  149735.    59,  /*        FOR => ID */

  149736.    59,  /*     IGNORE => ID */

  149737.    59,  /*  INITIALLY => ID */

  149738.    59,  /*    INSTEAD => ID */

  149739.    59,  /*         NO => ID */

  149740.    59,  /*        KEY => ID */

  149741.    59,  /*         OF => ID */

  149742.    59,  /*     OFFSET => ID */

  149743.    59,  /*     PRAGMA => ID */

  149744.    59,  /*      RAISE => ID */

  149745.    59,  /*  RECURSIVE => ID */

  149746.    59,  /*    REPLACE => ID */

  149747.    59,  /*   RESTRICT => ID */

  149748.    59,  /*        ROW => ID */

  149749.    59,  /*       ROWS => ID */

  149750.    59,  /*    TRIGGER => ID */

  149751.    59,  /*     VACUUM => ID */

  149752.    59,  /*       VIEW => ID */

  149753.    59,  /*    VIRTUAL => ID */

  149754.    59,  /*       WITH => ID */

  149755.    59,  /*    CURRENT => ID */

  149756.    59,  /*  FOLLOWING => ID */

  149757.    59,  /*  PARTITION => ID */

  149758.    59,  /*  PRECEDING => ID */

  149759.    59,  /*      RANGE => ID */

  149760.    59,  /*  UNBOUNDED => ID */

  149761.    59,  /*    EXCLUDE => ID */

  149762.    59,  /*     GROUPS => ID */

  149763.    59,  /*     OTHERS => ID */

  149764.    59,  /*       TIES => ID */

  149765.    59,  /*    REINDEX => ID */

  149766.    59,  /*     RENAME => ID */

  149767.    59,  /*   CTIME_KW => ID */

  149768. };

  149769. #endif /* YYFALLBACK */

  149770. 

  149771. /* The following structure represents a single element of the

  149772. ** parser's stack.  Information stored includes:

  149773. **

  149774. **   +  The state number for the parser at this level of the stack.

  149775. **

  149776. **   +  The value of the token stored at this level of the stack.

  149777. **      (In other words, the "major" token.)

  149778. **

  149779. **   +  The semantic value stored at this level of the stack.  This is

  149780. **      the information used by the action routines in the grammar.

  149781. **      It is sometimes called the "minor" token.

  149782. **

  149783. ** After the "shift" half of a SHIFTREDUCE action, the stateno field

  149784. ** actually contains the reduce action for the second half of the

  149785. ** SHIFTREDUCE.

  149786. */

  149787. struct yyStackEntry {

  149788.   YYACTIONTYPE stateno;  /* The state-number, or reduce action in SHIFTREDUCE */

  149789.   YYCODETYPE major;      /* The major token value.  This is the code

  149790.                          ** number for the token at this stack level */

  149791.   YYMINORTYPE minor;     /* The user-supplied minor token value.  This

  149792.                          ** is the value of the token  */

  149793. };

  149794. typedef struct yyStackEntry yyStackEntry;

  149795. 

  149796. /* The state of the parser is completely contained in an instance of

  149797. ** the following structure */

  149798. struct yyParser {

  149799.   yyStackEntry *yytos;          /* Pointer to top element of the stack */

  149800. #ifdef YYTRACKMAXSTACKDEPTH

  149801.   int yyhwm;                    /* High-water mark of the stack */

  149802. #endif

  149803. #ifndef YYNOERRORRECOVERY

  149804.   int yyerrcnt;                 /* Shifts left before out of the error */

  149805. #endif

  149806.   sqlite3ParserARG_SDECL                /* A place to hold %extra_argument */

  149807.   sqlite3ParserCTX_SDECL                /* A place to hold %extra_context */

  149808. #if YYSTACKDEPTH<=0

  149809.   int yystksz;                  /* Current side of the stack */

  149810.   yyStackEntry *yystack;        /* The parser's stack */

  149811.   yyStackEntry yystk0;          /* First stack entry */

  149812. #else

  149813.   yyStackEntry yystack[YYSTACKDEPTH];  /* The parser's stack */

  149814.   yyStackEntry *yystackEnd;            /* Last entry in the stack */

  149815. #endif

  149816. };

  149817. typedef struct yyParser yyParser;

  149818. 

  149819. #ifndef NDEBUG

  149820. /* #include <stdio.h> */

  149821. static FILE *yyTraceFILE = 0;

  149822. static char *yyTracePrompt = 0;

  149823. #endif /* NDEBUG */

  149824. 

  149825. #ifndef NDEBUG

  149826. /* 

  149827. ** Turn parser tracing on by giving a stream to which to write the trace

  149828. ** and a prompt to preface each trace message.  Tracing is turned off

  149829. ** by making either argument NULL 

  149830. **

  149831. ** Inputs:

  149832. ** <ul>

  149833. ** <li> A FILE* to which trace output should be written.

  149834. **      If NULL, then tracing is turned off.

  149835. ** <li> A prefix string written at the beginning of every

  149836. **      line of trace output.  If NULL, then tracing is

  149837. **      turned off.

  149838. ** </ul>

  149839. **

  149840. ** Outputs:

  149841. ** None.

  149842. */

  149843. SQLITE_PRIVATE void sqlite3ParserTrace(FILE *TraceFILE, char *zTracePrompt){

  149844.   yyTraceFILE = TraceFILE;

  149845.   yyTracePrompt = zTracePrompt;

  149846.   if( yyTraceFILE==0 ) yyTracePrompt = 0;

  149847.   else if( yyTracePrompt==0 ) yyTraceFILE = 0;

  149848. }

  149849. #endif /* NDEBUG */

  149850. 

  149851. #if defined(YYCOVERAGE) || !defined(NDEBUG)

  149852. /* For tracing shifts, the names of all terminals and nonterminals

  149853. ** are required.  The following table supplies these names */

  149854. static const char *const yyTokenName[] = { 

  149855.   /*    0 */ "$",

  149856.   /*    1 */ "SEMI",

  149857.   /*    2 */ "EXPLAIN",

  149858.   /*    3 */ "QUERY",

  149859.   /*    4 */ "PLAN",

  149860.   /*    5 */ "BEGIN",

  149861.   /*    6 */ "TRANSACTION",

  149862.   /*    7 */ "DEFERRED",

  149863.   /*    8 */ "IMMEDIATE",

  149864.   /*    9 */ "EXCLUSIVE",

  149865.   /*   10 */ "COMMIT",

  149866.   /*   11 */ "END",

  149867.   /*   12 */ "ROLLBACK",

  149868.   /*   13 */ "SAVEPOINT",

  149869.   /*   14 */ "RELEASE",

  149870.   /*   15 */ "TO",

  149871.   /*   16 */ "TABLE",

  149872.   /*   17 */ "CREATE",

  149873.   /*   18 */ "IF",

  149874.   /*   19 */ "NOT",

  149875.   /*   20 */ "EXISTS",

  149876.   /*   21 */ "TEMP",

  149877.   /*   22 */ "LP",

  149878.   /*   23 */ "RP",

  149879.   /*   24 */ "AS",

  149880.   /*   25 */ "WITHOUT",

  149881.   /*   26 */ "COMMA",

  149882.   /*   27 */ "ABORT",

  149883.   /*   28 */ "ACTION",

  149884.   /*   29 */ "AFTER",

  149885.   /*   30 */ "ANALYZE",

  149886.   /*   31 */ "ASC",

  149887.   /*   32 */ "ATTACH",

  149888.   /*   33 */ "BEFORE",

  149889.   /*   34 */ "BY",

  149890.   /*   35 */ "CASCADE",

  149891.   /*   36 */ "CAST",

  149892.   /*   37 */ "CONFLICT",

  149893.   /*   38 */ "DATABASE",

  149894.   /*   39 */ "DESC",

  149895.   /*   40 */ "DETACH",

  149896.   /*   41 */ "EACH",

  149897.   /*   42 */ "FAIL",

  149898.   /*   43 */ "OR",

  149899.   /*   44 */ "AND",

  149900.   /*   45 */ "IS",

  149901.   /*   46 */ "MATCH",

  149902.   /*   47 */ "LIKE_KW",

  149903.   /*   48 */ "BETWEEN",

  149904.   /*   49 */ "IN",

  149905.   /*   50 */ "ISNULL",

  149906.   /*   51 */ "NOTNULL",

  149907.   /*   52 */ "NE",

  149908.   /*   53 */ "EQ",

  149909.   /*   54 */ "GT",

  149910.   /*   55 */ "LE",

  149911.   /*   56 */ "LT",

  149912.   /*   57 */ "GE",

  149913.   /*   58 */ "ESCAPE",

  149914.   /*   59 */ "ID",

  149915.   /*   60 */ "COLUMNKW",

  149916.   /*   61 */ "DO",

  149917.   /*   62 */ "FOR",

  149918.   /*   63 */ "IGNORE",

  149919.   /*   64 */ "INITIALLY",

  149920.   /*   65 */ "INSTEAD",

  149921.   /*   66 */ "NO",

  149922.   /*   67 */ "KEY",

  149923.   /*   68 */ "OF",

  149924.   /*   69 */ "OFFSET",

  149925.   /*   70 */ "PRAGMA",

  149926.   /*   71 */ "RAISE",

  149927.   /*   72 */ "RECURSIVE",

  149928.   /*   73 */ "REPLACE",

  149929.   /*   74 */ "RESTRICT",

  149930.   /*   75 */ "ROW",

  149931.   /*   76 */ "ROWS",

  149932.   /*   77 */ "TRIGGER",

  149933.   /*   78 */ "VACUUM",

  149934.   /*   79 */ "VIEW",

  149935.   /*   80 */ "VIRTUAL",

  149936.   /*   81 */ "WITH",

  149937.   /*   82 */ "CURRENT",

  149938.   /*   83 */ "FOLLOWING",

  149939.   /*   84 */ "PARTITION",

  149940.   /*   85 */ "PRECEDING",

  149941.   /*   86 */ "RANGE",

  149942.   /*   87 */ "UNBOUNDED",

  149943.   /*   88 */ "EXCLUDE",

  149944.   /*   89 */ "GROUPS",

  149945.   /*   90 */ "OTHERS",

  149946.   /*   91 */ "TIES",

  149947.   /*   92 */ "REINDEX",

  149948.   /*   93 */ "RENAME",

  149949.   /*   94 */ "CTIME_KW",

  149950.   /*   95 */ "ANY",

  149951.   /*   96 */ "BITAND",

  149952.   /*   97 */ "BITOR",

  149953.   /*   98 */ "LSHIFT",

  149954.   /*   99 */ "RSHIFT",

  149955.   /*  100 */ "PLUS",

  149956.   /*  101 */ "MINUS",

  149957.   /*  102 */ "STAR",

  149958.   /*  103 */ "SLASH",

  149959.   /*  104 */ "REM",

  149960.   /*  105 */ "CONCAT",

  149961.   /*  106 */ "COLLATE",

  149962.   /*  107 */ "BITNOT",

  149963.   /*  108 */ "ON",

  149964.   /*  109 */ "INDEXED",

  149965.   /*  110 */ "STRING",

  149966.   /*  111 */ "JOIN_KW",

  149967.   /*  112 */ "CONSTRAINT",

  149968.   /*  113 */ "DEFAULT",

  149969.   /*  114 */ "NULL",

  149970.   /*  115 */ "PRIMARY",

  149971.   /*  116 */ "UNIQUE",

  149972.   /*  117 */ "CHECK",

  149973.   /*  118 */ "REFERENCES",

  149974.   /*  119 */ "AUTOINCR",

  149975.   /*  120 */ "INSERT",

  149976.   /*  121 */ "DELETE",

  149977.   /*  122 */ "UPDATE",

  149978.   /*  123 */ "SET",

  149979.   /*  124 */ "DEFERRABLE",

  149980.   /*  125 */ "FOREIGN",

  149981.   /*  126 */ "DROP",

  149982.   /*  127 */ "UNION",

  149983.   /*  128 */ "ALL",

  149984.   /*  129 */ "EXCEPT",

  149985.   /*  130 */ "INTERSECT",

  149986.   /*  131 */ "SELECT",

  149987.   /*  132 */ "VALUES",

  149988.   /*  133 */ "DISTINCT",

  149989.   /*  134 */ "DOT",

  149990.   /*  135 */ "FROM",

  149991.   /*  136 */ "JOIN",

  149992.   /*  137 */ "USING",

  149993.   /*  138 */ "ORDER",

  149994.   /*  139 */ "GROUP",

  149995.   /*  140 */ "HAVING",

  149996.   /*  141 */ "LIMIT",

  149997.   /*  142 */ "WHERE",

  149998.   /*  143 */ "INTO",

  149999.   /*  144 */ "NOTHING",

  150000.   /*  145 */ "FLOAT",

  150001.   /*  146 */ "BLOB",

  150002.   /*  147 */ "INTEGER",

  150003.   /*  148 */ "VARIABLE",

  150004.   /*  149 */ "CASE",

  150005.   /*  150 */ "WHEN",

  150006.   /*  151 */ "THEN",

  150007.   /*  152 */ "ELSE",

  150008.   /*  153 */ "INDEX",

  150009.   /*  154 */ "ALTER",

  150010.   /*  155 */ "ADD",

  150011.   /*  156 */ "WINDOW",

  150012.   /*  157 */ "OVER",

  150013.   /*  158 */ "FILTER",

  150014.   /*  159 */ "TRUEFALSE",

  150015.   /*  160 */ "ISNOT",

  150016.   /*  161 */ "FUNCTION",

  150017.   /*  162 */ "COLUMN",

  150018.   /*  163 */ "AGG_FUNCTION",

  150019.   /*  164 */ "AGG_COLUMN",

  150020.   /*  165 */ "UMINUS",

  150021.   /*  166 */ "UPLUS",

  150022.   /*  167 */ "TRUTH",

  150023.   /*  168 */ "REGISTER",

  150024.   /*  169 */ "VECTOR",

  150025.   /*  170 */ "SELECT_COLUMN",

  150026.   /*  171 */ "IF_NULL_ROW",

  150027.   /*  172 */ "ASTERISK",

  150028.   /*  173 */ "SPAN",

  150029.   /*  174 */ "SPACE",

  150030.   /*  175 */ "ILLEGAL",

  150031.   /*  176 */ "input",

  150032.   /*  177 */ "cmdlist",

  150033.   /*  178 */ "ecmd",

  150034.   /*  179 */ "cmdx",

  150035.   /*  180 */ "explain",

  150036.   /*  181 */ "cmd",

  150037.   /*  182 */ "transtype",

  150038.   /*  183 */ "trans_opt",

  150039.   /*  184 */ "nm",

  150040.   /*  185 */ "savepoint_opt",

  150041.   /*  186 */ "create_table",

  150042.   /*  187 */ "create_table_args",

  150043.   /*  188 */ "createkw",

  150044.   /*  189 */ "temp",

  150045.   /*  190 */ "ifnotexists",

  150046.   /*  191 */ "dbnm",

  150047.   /*  192 */ "columnlist",

  150048.   /*  193 */ "conslist_opt",

  150049.   /*  194 */ "table_options",

  150050.   /*  195 */ "select",

  150051.   /*  196 */ "columnname",

  150052.   /*  197 */ "carglist",

  150053.   /*  198 */ "typetoken",

  150054.   /*  199 */ "typename",

  150055.   /*  200 */ "signed",

  150056.   /*  201 */ "plus_num",

  150057.   /*  202 */ "minus_num",

  150058.   /*  203 */ "scanpt",

  150059.   /*  204 */ "scantok",

  150060.   /*  205 */ "ccons",

  150061.   /*  206 */ "term",

  150062.   /*  207 */ "expr",

  150063.   /*  208 */ "onconf",

  150064.   /*  209 */ "sortorder",

  150065.   /*  210 */ "autoinc",

  150066.   /*  211 */ "eidlist_opt",

  150067.   /*  212 */ "refargs",

  150068.   /*  213 */ "defer_subclause",

  150069.   /*  214 */ "refarg",

  150070.   /*  215 */ "refact",

  150071.   /*  216 */ "init_deferred_pred_opt",

  150072.   /*  217 */ "conslist",

  150073.   /*  218 */ "tconscomma",

  150074.   /*  219 */ "tcons",

  150075.   /*  220 */ "sortlist",

  150076.   /*  221 */ "eidlist",

  150077.   /*  222 */ "defer_subclause_opt",

  150078.   /*  223 */ "orconf",

  150079.   /*  224 */ "resolvetype",

  150080.   /*  225 */ "raisetype",

  150081.   /*  226 */ "ifexists",

  150082.   /*  227 */ "fullname",

  150083.   /*  228 */ "selectnowith",

  150084.   /*  229 */ "oneselect",

  150085.   /*  230 */ "wqlist",

  150086.   /*  231 */ "multiselect_op",

  150087.   /*  232 */ "distinct",

  150088.   /*  233 */ "selcollist",

  150089.   /*  234 */ "from",

  150090.   /*  235 */ "where_opt",

  150091.   /*  236 */ "groupby_opt",

  150092.   /*  237 */ "having_opt",

  150093.   /*  238 */ "orderby_opt",

  150094.   /*  239 */ "limit_opt",

  150095.   /*  240 */ "window_clause",

  150096.   /*  241 */ "values",

  150097.   /*  242 */ "nexprlist",

  150098.   /*  243 */ "sclp",

  150099.   /*  244 */ "as",

  150100.   /*  245 */ "seltablist",

  150101.   /*  246 */ "stl_prefix",

  150102.   /*  247 */ "joinop",

  150103.   /*  248 */ "indexed_opt",

  150104.   /*  249 */ "on_opt",

  150105.   /*  250 */ "using_opt",

  150106.   /*  251 */ "exprlist",

  150107.   /*  252 */ "xfullname",

  150108.   /*  253 */ "idlist",

  150109.   /*  254 */ "with",

  150110.   /*  255 */ "setlist",

  150111.   /*  256 */ "insert_cmd",

  150112.   /*  257 */ "idlist_opt",

  150113.   /*  258 */ "upsert",

  150114.   /*  259 */ "over_clause",

  150115.   /*  260 */ "likeop",

  150116.   /*  261 */ "between_op",

  150117.   /*  262 */ "in_op",

  150118.   /*  263 */ "paren_exprlist",

  150119.   /*  264 */ "case_operand",

  150120.   /*  265 */ "case_exprlist",

  150121.   /*  266 */ "case_else",

  150122.   /*  267 */ "uniqueflag",

  150123.   /*  268 */ "collate",

  150124.   /*  269 */ "vinto",

  150125.   /*  270 */ "nmnum",

  150126.   /*  271 */ "trigger_decl",

  150127.   /*  272 */ "trigger_cmd_list",

  150128.   /*  273 */ "trigger_time",

  150129.   /*  274 */ "trigger_event",

  150130.   /*  275 */ "foreach_clause",

  150131.   /*  276 */ "when_clause",

  150132.   /*  277 */ "trigger_cmd",

  150133.   /*  278 */ "trnm",

  150134.   /*  279 */ "tridxby",

  150135.   /*  280 */ "database_kw_opt",

  150136.   /*  281 */ "key_opt",

  150137.   /*  282 */ "add_column_fullname",

  150138.   /*  283 */ "kwcolumn_opt",

  150139.   /*  284 */ "create_vtab",

  150140.   /*  285 */ "vtabarglist",

  150141.   /*  286 */ "vtabarg",

  150142.   /*  287 */ "vtabargtoken",

  150143.   /*  288 */ "lp",

  150144.   /*  289 */ "anylist",

  150145.   /*  290 */ "windowdefn_list",

  150146.   /*  291 */ "windowdefn",

  150147.   /*  292 */ "window",

  150148.   /*  293 */ "frame_opt",

  150149.   /*  294 */ "part_opt",

  150150.   /*  295 */ "filter_opt",

  150151.   /*  296 */ "range_or_rows",

  150152.   /*  297 */ "frame_bound",

  150153.   /*  298 */ "frame_bound_s",

  150154.   /*  299 */ "frame_bound_e",

  150155.   /*  300 */ "frame_exclude_opt",

  150156.   /*  301 */ "frame_exclude",

  150157. };

  150158. #endif /* defined(YYCOVERAGE) || !defined(NDEBUG) */

  150159. 

  150160. #ifndef NDEBUG

  150161. /* For tracing reduce actions, the names of all rules are required.

  150162. */

  150163. static const char *const yyRuleName[] = {

  150164.  /*   0 */ "explain ::= EXPLAIN",

  150165.  /*   1 */ "explain ::= EXPLAIN QUERY PLAN",

  150166.  /*   2 */ "cmdx ::= cmd",

  150167.  /*   3 */ "cmd ::= BEGIN transtype trans_opt",

  150168.  /*   4 */ "transtype ::=",

  150169.  /*   5 */ "transtype ::= DEFERRED",

  150170.  /*   6 */ "transtype ::= IMMEDIATE",

  150171.  /*   7 */ "transtype ::= EXCLUSIVE",

  150172.  /*   8 */ "cmd ::= COMMIT|END trans_opt",

  150173.  /*   9 */ "cmd ::= ROLLBACK trans_opt",

  150174.  /*  10 */ "cmd ::= SAVEPOINT nm",

  150175.  /*  11 */ "cmd ::= RELEASE savepoint_opt nm",

  150176.  /*  12 */ "cmd ::= ROLLBACK trans_opt TO savepoint_opt nm",

  150177.  /*  13 */ "create_table ::= createkw temp TABLE ifnotexists nm dbnm",

  150178.  /*  14 */ "createkw ::= CREATE",

  150179.  /*  15 */ "ifnotexists ::=",

  150180.  /*  16 */ "ifnotexists ::= IF NOT EXISTS",

  150181.  /*  17 */ "temp ::= TEMP",

  150182.  /*  18 */ "temp ::=",

  150183.  /*  19 */ "create_table_args ::= LP columnlist conslist_opt RP table_options",

  150184.  /*  20 */ "create_table_args ::= AS select",

  150185.  /*  21 */ "table_options ::=",

  150186.  /*  22 */ "table_options ::= WITHOUT nm",

  150187.  /*  23 */ "columnname ::= nm typetoken",

  150188.  /*  24 */ "typetoken ::=",

  150189.  /*  25 */ "typetoken ::= typename LP signed RP",

  150190.  /*  26 */ "typetoken ::= typename LP signed COMMA signed RP",

  150191.  /*  27 */ "typename ::= typename ID|STRING",

  150192.  /*  28 */ "scanpt ::=",

  150193.  /*  29 */ "scantok ::=",

  150194.  /*  30 */ "ccons ::= CONSTRAINT nm",

  150195.  /*  31 */ "ccons ::= DEFAULT scantok term",

  150196.  /*  32 */ "ccons ::= DEFAULT LP expr RP",

  150197.  /*  33 */ "ccons ::= DEFAULT PLUS scantok term",

  150198.  /*  34 */ "ccons ::= DEFAULT MINUS scantok term",

  150199.  /*  35 */ "ccons ::= DEFAULT scantok ID|INDEXED",

  150200.  /*  36 */ "ccons ::= NOT NULL onconf",

  150201.  /*  37 */ "ccons ::= PRIMARY KEY sortorder onconf autoinc",

  150202.  /*  38 */ "ccons ::= UNIQUE onconf",

  150203.  /*  39 */ "ccons ::= CHECK LP expr RP",

  150204.  /*  40 */ "ccons ::= REFERENCES nm eidlist_opt refargs",

  150205.  /*  41 */ "ccons ::= defer_subclause",

  150206.  /*  42 */ "ccons ::= COLLATE ID|STRING",

  150207.  /*  43 */ "autoinc ::=",

  150208.  /*  44 */ "autoinc ::= AUTOINCR",

  150209.  /*  45 */ "refargs ::=",

  150210.  /*  46 */ "refargs ::= refargs refarg",

  150211.  /*  47 */ "refarg ::= MATCH nm",

  150212.  /*  48 */ "refarg ::= ON INSERT refact",

  150213.  /*  49 */ "refarg ::= ON DELETE refact",

  150214.  /*  50 */ "refarg ::= ON UPDATE refact",

  150215.  /*  51 */ "refact ::= SET NULL",

  150216.  /*  52 */ "refact ::= SET DEFAULT",

  150217.  /*  53 */ "refact ::= CASCADE",

  150218.  /*  54 */ "refact ::= RESTRICT",

  150219.  /*  55 */ "refact ::= NO ACTION",

  150220.  /*  56 */ "defer_subclause ::= NOT DEFERRABLE init_deferred_pred_opt",

  150221.  /*  57 */ "defer_subclause ::= DEFERRABLE init_deferred_pred_opt",

  150222.  /*  58 */ "init_deferred_pred_opt ::=",

  150223.  /*  59 */ "init_deferred_pred_opt ::= INITIALLY DEFERRED",

  150224.  /*  60 */ "init_deferred_pred_opt ::= INITIALLY IMMEDIATE",

  150225.  /*  61 */ "conslist_opt ::=",

  150226.  /*  62 */ "tconscomma ::= COMMA",

  150227.  /*  63 */ "tcons ::= CONSTRAINT nm",

  150228.  /*  64 */ "tcons ::= PRIMARY KEY LP sortlist autoinc RP onconf",

  150229.  /*  65 */ "tcons ::= UNIQUE LP sortlist RP onconf",

  150230.  /*  66 */ "tcons ::= CHECK LP expr RP onconf",

  150231.  /*  67 */ "tcons ::= FOREIGN KEY LP eidlist RP REFERENCES nm eidlist_opt refargs defer_subclause_opt",

  150232.  /*  68 */ "defer_subclause_opt ::=",

  150233.  /*  69 */ "onconf ::=",

  150234.  /*  70 */ "onconf ::= ON CONFLICT resolvetype",

  150235.  /*  71 */ "orconf ::=",

  150236.  /*  72 */ "orconf ::= OR resolvetype",

  150237.  /*  73 */ "resolvetype ::= IGNORE",

  150238.  /*  74 */ "resolvetype ::= REPLACE",

  150239.  /*  75 */ "cmd ::= DROP TABLE ifexists fullname",

  150240.  /*  76 */ "ifexists ::= IF EXISTS",

  150241.  /*  77 */ "ifexists ::=",

  150242.  /*  78 */ "cmd ::= createkw temp VIEW ifnotexists nm dbnm eidlist_opt AS select",

  150243.  /*  79 */ "cmd ::= DROP VIEW ifexists fullname",

  150244.  /*  80 */ "cmd ::= select",

  150245.  /*  81 */ "select ::= WITH wqlist selectnowith",

  150246.  /*  82 */ "select ::= WITH RECURSIVE wqlist selectnowith",

  150247.  /*  83 */ "select ::= selectnowith",

  150248.  /*  84 */ "selectnowith ::= selectnowith multiselect_op oneselect",

  150249.  /*  85 */ "multiselect_op ::= UNION",

  150250.  /*  86 */ "multiselect_op ::= UNION ALL",

  150251.  /*  87 */ "multiselect_op ::= EXCEPT|INTERSECT",

  150252.  /*  88 */ "oneselect ::= SELECT distinct selcollist from where_opt groupby_opt having_opt orderby_opt limit_opt",

  150253.  /*  89 */ "oneselect ::= SELECT distinct selcollist from where_opt groupby_opt having_opt window_clause orderby_opt limit_opt",

  150254.  /*  90 */ "values ::= VALUES LP nexprlist RP",

  150255.  /*  91 */ "values ::= values COMMA LP nexprlist RP",

  150256.  /*  92 */ "distinct ::= DISTINCT",

  150257.  /*  93 */ "distinct ::= ALL",

  150258.  /*  94 */ "distinct ::=",

  150259.  /*  95 */ "sclp ::=",

  150260.  /*  96 */ "selcollist ::= sclp scanpt expr scanpt as",

  150261.  /*  97 */ "selcollist ::= sclp scanpt STAR",

  150262.  /*  98 */ "selcollist ::= sclp scanpt nm DOT STAR",

  150263.  /*  99 */ "as ::= AS nm",

  150264.  /* 100 */ "as ::=",

  150265.  /* 101 */ "from ::=",

  150266.  /* 102 */ "from ::= FROM seltablist",

  150267.  /* 103 */ "stl_prefix ::= seltablist joinop",

  150268.  /* 104 */ "stl_prefix ::=",

  150269.  /* 105 */ "seltablist ::= stl_prefix nm dbnm as indexed_opt on_opt using_opt",

  150270.  /* 106 */ "seltablist ::= stl_prefix nm dbnm LP exprlist RP as on_opt using_opt",

  150271.  /* 107 */ "seltablist ::= stl_prefix LP select RP as on_opt using_opt",

  150272.  /* 108 */ "seltablist ::= stl_prefix LP seltablist RP as on_opt using_opt",

  150273.  /* 109 */ "dbnm ::=",

  150274.  /* 110 */ "dbnm ::= DOT nm",

  150275.  /* 111 */ "fullname ::= nm",

  150276.  /* 112 */ "fullname ::= nm DOT nm",

  150277.  /* 113 */ "xfullname ::= nm",

  150278.  /* 114 */ "xfullname ::= nm DOT nm",

  150279.  /* 115 */ "xfullname ::= nm DOT nm AS nm",

  150280.  /* 116 */ "xfullname ::= nm AS nm",

  150281.  /* 117 */ "joinop ::= COMMA|JOIN",

  150282.  /* 118 */ "joinop ::= JOIN_KW JOIN",

  150283.  /* 119 */ "joinop ::= JOIN_KW nm JOIN",

  150284.  /* 120 */ "joinop ::= JOIN_KW nm nm JOIN",

  150285.  /* 121 */ "on_opt ::= ON expr",

  150286.  /* 122 */ "on_opt ::=",

  150287.  /* 123 */ "indexed_opt ::=",

  150288.  /* 124 */ "indexed_opt ::= INDEXED BY nm",

  150289.  /* 125 */ "indexed_opt ::= NOT INDEXED",

  150290.  /* 126 */ "using_opt ::= USING LP idlist RP",

  150291.  /* 127 */ "using_opt ::=",

  150292.  /* 128 */ "orderby_opt ::=",

  150293.  /* 129 */ "orderby_opt ::= ORDER BY sortlist",

  150294.  /* 130 */ "sortlist ::= sortlist COMMA expr sortorder",

  150295.  /* 131 */ "sortlist ::= expr sortorder",

  150296.  /* 132 */ "sortorder ::= ASC",

  150297.  /* 133 */ "sortorder ::= DESC",

  150298.  /* 134 */ "sortorder ::=",

  150299.  /* 135 */ "groupby_opt ::=",

  150300.  /* 136 */ "groupby_opt ::= GROUP BY nexprlist",

  150301.  /* 137 */ "having_opt ::=",

  150302.  /* 138 */ "having_opt ::= HAVING expr",

  150303.  /* 139 */ "limit_opt ::=",

  150304.  /* 140 */ "limit_opt ::= LIMIT expr",

  150305.  /* 141 */ "limit_opt ::= LIMIT expr OFFSET expr",

  150306.  /* 142 */ "limit_opt ::= LIMIT expr COMMA expr",

  150307.  /* 143 */ "cmd ::= with DELETE FROM xfullname indexed_opt where_opt",

  150308.  /* 144 */ "where_opt ::=",

  150309.  /* 145 */ "where_opt ::= WHERE expr",

  150310.  /* 146 */ "cmd ::= with UPDATE orconf xfullname indexed_opt SET setlist where_opt",

  150311.  /* 147 */ "setlist ::= setlist COMMA nm EQ expr",

  150312.  /* 148 */ "setlist ::= setlist COMMA LP idlist RP EQ expr",

  150313.  /* 149 */ "setlist ::= nm EQ expr",

  150314.  /* 150 */ "setlist ::= LP idlist RP EQ expr",

  150315.  /* 151 */ "cmd ::= with insert_cmd INTO xfullname idlist_opt select upsert",

  150316.  /* 152 */ "cmd ::= with insert_cmd INTO xfullname idlist_opt DEFAULT VALUES",

  150317.  /* 153 */ "upsert ::=",

  150318.  /* 154 */ "upsert ::= ON CONFLICT LP sortlist RP where_opt DO UPDATE SET setlist where_opt",

  150319.  /* 155 */ "upsert ::= ON CONFLICT LP sortlist RP where_opt DO NOTHING",

  150320.  /* 156 */ "upsert ::= ON CONFLICT DO NOTHING",

  150321.  /* 157 */ "insert_cmd ::= INSERT orconf",

  150322.  /* 158 */ "insert_cmd ::= REPLACE",

  150323.  /* 159 */ "idlist_opt ::=",

  150324.  /* 160 */ "idlist_opt ::= LP idlist RP",

  150325.  /* 161 */ "idlist ::= idlist COMMA nm",

  150326.  /* 162 */ "idlist ::= nm",

  150327.  /* 163 */ "expr ::= LP expr RP",

  150328.  /* 164 */ "expr ::= ID|INDEXED",

  150329.  /* 165 */ "expr ::= JOIN_KW",

  150330.  /* 166 */ "expr ::= nm DOT nm",

  150331.  /* 167 */ "expr ::= nm DOT nm DOT nm",

  150332.  /* 168 */ "term ::= NULL|FLOAT|BLOB",

  150333.  /* 169 */ "term ::= STRING",

  150334.  /* 170 */ "term ::= INTEGER",

  150335.  /* 171 */ "expr ::= VARIABLE",

  150336.  /* 172 */ "expr ::= expr COLLATE ID|STRING",

  150337.  /* 173 */ "expr ::= CAST LP expr AS typetoken RP",

  150338.  /* 174 */ "expr ::= ID|INDEXED LP distinct exprlist RP",

  150339.  /* 175 */ "expr ::= ID|INDEXED LP STAR RP",

  150340.  /* 176 */ "expr ::= ID|INDEXED LP distinct exprlist RP over_clause",

  150341.  /* 177 */ "expr ::= ID|INDEXED LP STAR RP over_clause",

  150342.  /* 178 */ "term ::= CTIME_KW",

  150343.  /* 179 */ "expr ::= LP nexprlist COMMA expr RP",

  150344.  /* 180 */ "expr ::= expr AND expr",

  150345.  /* 181 */ "expr ::= expr OR expr",

  150346.  /* 182 */ "expr ::= expr LT|GT|GE|LE expr",

  150347.  /* 183 */ "expr ::= expr EQ|NE expr",

  150348.  /* 184 */ "expr ::= expr BITAND|BITOR|LSHIFT|RSHIFT expr",

  150349.  /* 185 */ "expr ::= expr PLUS|MINUS expr",

  150350.  /* 186 */ "expr ::= expr STAR|SLASH|REM expr",

  150351.  /* 187 */ "expr ::= expr CONCAT expr",

  150352.  /* 188 */ "likeop ::= NOT LIKE_KW|MATCH",

  150353.  /* 189 */ "expr ::= expr likeop expr",

  150354.  /* 190 */ "expr ::= expr likeop expr ESCAPE expr",

  150355.  /* 191 */ "expr ::= expr ISNULL|NOTNULL",

  150356.  /* 192 */ "expr ::= expr NOT NULL",

  150357.  /* 193 */ "expr ::= expr IS expr",

  150358.  /* 194 */ "expr ::= expr IS NOT expr",

  150359.  /* 195 */ "expr ::= NOT expr",

  150360.  /* 196 */ "expr ::= BITNOT expr",

  150361.  /* 197 */ "expr ::= PLUS|MINUS expr",

  150362.  /* 198 */ "between_op ::= BETWEEN",

  150363.  /* 199 */ "between_op ::= NOT BETWEEN",

  150364.  /* 200 */ "expr ::= expr between_op expr AND expr",

  150365.  /* 201 */ "in_op ::= IN",

  150366.  /* 202 */ "in_op ::= NOT IN",

  150367.  /* 203 */ "expr ::= expr in_op LP exprlist RP",

  150368.  /* 204 */ "expr ::= LP select RP",

  150369.  /* 205 */ "expr ::= expr in_op LP select RP",

  150370.  /* 206 */ "expr ::= expr in_op nm dbnm paren_exprlist",

  150371.  /* 207 */ "expr ::= EXISTS LP select RP",

  150372.  /* 208 */ "expr ::= CASE case_operand case_exprlist case_else END",

  150373.  /* 209 */ "case_exprlist ::= case_exprlist WHEN expr THEN expr",

  150374.  /* 210 */ "case_exprlist ::= WHEN expr THEN expr",

  150375.  /* 211 */ "case_else ::= ELSE expr",

  150376.  /* 212 */ "case_else ::=",

  150377.  /* 213 */ "case_operand ::= expr",

  150378.  /* 214 */ "case_operand ::=",

  150379.  /* 215 */ "exprlist ::=",

  150380.  /* 216 */ "nexprlist ::= nexprlist COMMA expr",

  150381.  /* 217 */ "nexprlist ::= expr",

  150382.  /* 218 */ "paren_exprlist ::=",

  150383.  /* 219 */ "paren_exprlist ::= LP exprlist RP",

  150384.  /* 220 */ "cmd ::= createkw uniqueflag INDEX ifnotexists nm dbnm ON nm LP sortlist RP where_opt",

  150385.  /* 221 */ "uniqueflag ::= UNIQUE",

  150386.  /* 222 */ "uniqueflag ::=",

  150387.  /* 223 */ "eidlist_opt ::=",

  150388.  /* 224 */ "eidlist_opt ::= LP eidlist RP",

  150389.  /* 225 */ "eidlist ::= eidlist COMMA nm collate sortorder",

  150390.  /* 226 */ "eidlist ::= nm collate sortorder",

  150391.  /* 227 */ "collate ::=",

  150392.  /* 228 */ "collate ::= COLLATE ID|STRING",

  150393.  /* 229 */ "cmd ::= DROP INDEX ifexists fullname",

  150394.  /* 230 */ "cmd ::= VACUUM vinto",

  150395.  /* 231 */ "cmd ::= VACUUM nm vinto",

  150396.  /* 232 */ "vinto ::= INTO expr",

  150397.  /* 233 */ "vinto ::=",

  150398.  /* 234 */ "cmd ::= PRAGMA nm dbnm",

  150399.  /* 235 */ "cmd ::= PRAGMA nm dbnm EQ nmnum",

  150400.  /* 236 */ "cmd ::= PRAGMA nm dbnm LP nmnum RP",

  150401.  /* 237 */ "cmd ::= PRAGMA nm dbnm EQ minus_num",

  150402.  /* 238 */ "cmd ::= PRAGMA nm dbnm LP minus_num RP",

  150403.  /* 239 */ "plus_num ::= PLUS INTEGER|FLOAT",

  150404.  /* 240 */ "minus_num ::= MINUS INTEGER|FLOAT",

  150405.  /* 241 */ "cmd ::= createkw trigger_decl BEGIN trigger_cmd_list END",

  150406.  /* 242 */ "trigger_decl ::= temp TRIGGER ifnotexists nm dbnm trigger_time trigger_event ON fullname foreach_clause when_clause",

  150407.  /* 243 */ "trigger_time ::= BEFORE|AFTER",

  150408.  /* 244 */ "trigger_time ::= INSTEAD OF",

  150409.  /* 245 */ "trigger_time ::=",

  150410.  /* 246 */ "trigger_event ::= DELETE|INSERT",

  150411.  /* 247 */ "trigger_event ::= UPDATE",

  150412.  /* 248 */ "trigger_event ::= UPDATE OF idlist",

  150413.  /* 249 */ "when_clause ::=",

  150414.  /* 250 */ "when_clause ::= WHEN expr",

  150415.  /* 251 */ "trigger_cmd_list ::= trigger_cmd_list trigger_cmd SEMI",

  150416.  /* 252 */ "trigger_cmd_list ::= trigger_cmd SEMI",

  150417.  /* 253 */ "trnm ::= nm DOT nm",

  150418.  /* 254 */ "tridxby ::= INDEXED BY nm",

  150419.  /* 255 */ "tridxby ::= NOT INDEXED",

  150420.  /* 256 */ "trigger_cmd ::= UPDATE orconf trnm tridxby SET setlist where_opt scanpt",

  150421.  /* 257 */ "trigger_cmd ::= scanpt insert_cmd INTO trnm idlist_opt select upsert scanpt",

  150422.  /* 258 */ "trigger_cmd ::= DELETE FROM trnm tridxby where_opt scanpt",

  150423.  /* 259 */ "trigger_cmd ::= scanpt select scanpt",

  150424.  /* 260 */ "expr ::= RAISE LP IGNORE RP",

  150425.  /* 261 */ "expr ::= RAISE LP raisetype COMMA nm RP",

  150426.  /* 262 */ "raisetype ::= ROLLBACK",

  150427.  /* 263 */ "raisetype ::= ABORT",

  150428.  /* 264 */ "raisetype ::= FAIL",

  150429.  /* 265 */ "cmd ::= DROP TRIGGER ifexists fullname",

  150430.  /* 266 */ "cmd ::= ATTACH database_kw_opt expr AS expr key_opt",

  150431.  /* 267 */ "cmd ::= DETACH database_kw_opt expr",

  150432.  /* 268 */ "key_opt ::=",

  150433.  /* 269 */ "key_opt ::= KEY expr",

  150434.  /* 270 */ "cmd ::= REINDEX",

  150435.  /* 271 */ "cmd ::= REINDEX nm dbnm",

  150436.  /* 272 */ "cmd ::= ANALYZE",

  150437.  /* 273 */ "cmd ::= ANALYZE nm dbnm",

  150438.  /* 274 */ "cmd ::= ALTER TABLE fullname RENAME TO nm",

  150439.  /* 275 */ "cmd ::= ALTER TABLE add_column_fullname ADD kwcolumn_opt columnname carglist",

  150440.  /* 276 */ "add_column_fullname ::= fullname",

  150441.  /* 277 */ "cmd ::= ALTER TABLE fullname RENAME kwcolumn_opt nm TO nm",

  150442.  /* 278 */ "cmd ::= create_vtab",

  150443.  /* 279 */ "cmd ::= create_vtab LP vtabarglist RP",

  150444.  /* 280 */ "create_vtab ::= createkw VIRTUAL TABLE ifnotexists nm dbnm USING nm",

  150445.  /* 281 */ "vtabarg ::=",

  150446.  /* 282 */ "vtabargtoken ::= ANY",

  150447.  /* 283 */ "vtabargtoken ::= lp anylist RP",

  150448.  /* 284 */ "lp ::= LP",

  150449.  /* 285 */ "with ::= WITH wqlist",

  150450.  /* 286 */ "with ::= WITH RECURSIVE wqlist",

  150451.  /* 287 */ "wqlist ::= nm eidlist_opt AS LP select RP",

  150452.  /* 288 */ "wqlist ::= wqlist COMMA nm eidlist_opt AS LP select RP",

  150453.  /* 289 */ "windowdefn_list ::= windowdefn",

  150454.  /* 290 */ "windowdefn_list ::= windowdefn_list COMMA windowdefn",

  150455.  /* 291 */ "windowdefn ::= nm AS LP window RP",

  150456.  /* 292 */ "window ::= PARTITION BY nexprlist orderby_opt frame_opt",

  150457.  /* 293 */ "window ::= nm PARTITION BY nexprlist orderby_opt frame_opt",

  150458.  /* 294 */ "window ::= ORDER BY sortlist frame_opt",

  150459.  /* 295 */ "window ::= nm ORDER BY sortlist frame_opt",

  150460.  /* 296 */ "window ::= frame_opt",

  150461.  /* 297 */ "window ::= nm frame_opt",

  150462.  /* 298 */ "frame_opt ::=",

  150463.  /* 299 */ "frame_opt ::= range_or_rows frame_bound_s frame_exclude_opt",

  150464.  /* 300 */ "frame_opt ::= range_or_rows BETWEEN frame_bound_s AND frame_bound_e frame_exclude_opt",

  150465.  /* 301 */ "range_or_rows ::= RANGE|ROWS|GROUPS",

  150466.  /* 302 */ "frame_bound_s ::= frame_bound",

  150467.  /* 303 */ "frame_bound_s ::= UNBOUNDED PRECEDING",

  150468.  /* 304 */ "frame_bound_e ::= frame_bound",

  150469.  /* 305 */ "frame_bound_e ::= UNBOUNDED FOLLOWING",

  150470.  /* 306 */ "frame_bound ::= expr PRECEDING|FOLLOWING",

  150471.  /* 307 */ "frame_bound ::= CURRENT ROW",

  150472.  /* 308 */ "frame_exclude_opt ::=",

  150473.  /* 309 */ "frame_exclude_opt ::= EXCLUDE frame_exclude",

  150474.  /* 310 */ "frame_exclude ::= NO OTHERS",

  150475.  /* 311 */ "frame_exclude ::= CURRENT ROW",

  150476.  /* 312 */ "frame_exclude ::= GROUP|TIES",

  150477.  /* 313 */ "window_clause ::= WINDOW windowdefn_list",

  150478.  /* 314 */ "over_clause ::= filter_opt OVER LP window RP",

  150479.  /* 315 */ "over_clause ::= filter_opt OVER nm",

  150480.  /* 316 */ "filter_opt ::=",

  150481.  /* 317 */ "filter_opt ::= FILTER LP WHERE expr RP",

  150482.  /* 318 */ "input ::= cmdlist",

  150483.  /* 319 */ "cmdlist ::= cmdlist ecmd",

  150484.  /* 320 */ "cmdlist ::= ecmd",

  150485.  /* 321 */ "ecmd ::= SEMI",

  150486.  /* 322 */ "ecmd ::= cmdx SEMI",

  150487.  /* 323 */ "ecmd ::= explain cmdx",

  150488.  /* 324 */ "trans_opt ::=",

  150489.  /* 325 */ "trans_opt ::= TRANSACTION",

  150490.  /* 326 */ "trans_opt ::= TRANSACTION nm",

  150491.  /* 327 */ "savepoint_opt ::= SAVEPOINT",

  150492.  /* 328 */ "savepoint_opt ::=",

  150493.  /* 329 */ "cmd ::= create_table create_table_args",

  150494.  /* 330 */ "columnlist ::= columnlist COMMA columnname carglist",

  150495.  /* 331 */ "columnlist ::= columnname carglist",

  150496.  /* 332 */ "nm ::= ID|INDEXED",

  150497.  /* 333 */ "nm ::= STRING",

  150498.  /* 334 */ "nm ::= JOIN_KW",

  150499.  /* 335 */ "typetoken ::= typename",

  150500.  /* 336 */ "typename ::= ID|STRING",

  150501.  /* 337 */ "signed ::= plus_num",

  150502.  /* 338 */ "signed ::= minus_num",

  150503.  /* 339 */ "carglist ::= carglist ccons",

  150504.  /* 340 */ "carglist ::=",

  150505.  /* 341 */ "ccons ::= NULL onconf",

  150506.  /* 342 */ "conslist_opt ::= COMMA conslist",

  150507.  /* 343 */ "conslist ::= conslist tconscomma tcons",

  150508.  /* 344 */ "conslist ::= tcons",

  150509.  /* 345 */ "tconscomma ::=",

  150510.  /* 346 */ "defer_subclause_opt ::= defer_subclause",

  150511.  /* 347 */ "resolvetype ::= raisetype",

  150512.  /* 348 */ "selectnowith ::= oneselect",

  150513.  /* 349 */ "oneselect ::= values",

  150514.  /* 350 */ "sclp ::= selcollist COMMA",

  150515.  /* 351 */ "as ::= ID|STRING",

  150516.  /* 352 */ "expr ::= term",

  150517.  /* 353 */ "likeop ::= LIKE_KW|MATCH",

  150518.  /* 354 */ "exprlist ::= nexprlist",

  150519.  /* 355 */ "nmnum ::= plus_num",

  150520.  /* 356 */ "nmnum ::= nm",

  150521.  /* 357 */ "nmnum ::= ON",

  150522.  /* 358 */ "nmnum ::= DELETE",

  150523.  /* 359 */ "nmnum ::= DEFAULT",

  150524.  /* 360 */ "plus_num ::= INTEGER|FLOAT",

  150525.  /* 361 */ "foreach_clause ::=",

  150526.  /* 362 */ "foreach_clause ::= FOR EACH ROW",

  150527.  /* 363 */ "trnm ::= nm",

  150528.  /* 364 */ "tridxby ::=",

  150529.  /* 365 */ "database_kw_opt ::= DATABASE",

  150530.  /* 366 */ "database_kw_opt ::=",

  150531.  /* 367 */ "kwcolumn_opt ::=",

  150532.  /* 368 */ "kwcolumn_opt ::= COLUMNKW",

  150533.  /* 369 */ "vtabarglist ::= vtabarg",

  150534.  /* 370 */ "vtabarglist ::= vtabarglist COMMA vtabarg",

  150535.  /* 371 */ "vtabarg ::= vtabarg vtabargtoken",

  150536.  /* 372 */ "anylist ::=",

  150537.  /* 373 */ "anylist ::= anylist LP anylist RP",

  150538.  /* 374 */ "anylist ::= anylist ANY",

  150539.  /* 375 */ "with ::=",

  150540. };

  150541. #endif /* NDEBUG */

  150542. 

  150543. 

  150544. #if YYSTACKDEPTH<=0

  150545. /*

  150546. ** Try to increase the size of the parser stack.  Return the number

  150547. ** of errors.  Return 0 on success.

  150548. */

  150549. static int yyGrowStack(yyParser *p){

  150550.   int newSize;

  150551.   int idx;

  150552.   yyStackEntry *pNew;

  150553. 

  150554.   newSize = p->yystksz*2 + 100;

  150555.   idx = p->yytos ? (int)(p->yytos - p->yystack) : 0;

  150556.   if( p->yystack==&p->yystk0 ){

  150557.     pNew = malloc(newSize*sizeof(pNew[0]));

  150558.     if( pNew ) pNew[0] = p->yystk0;

  150559.   }else{

  150560.     pNew = realloc(p->yystack, newSize*sizeof(pNew[0]));

  150561.   }

  150562.   if( pNew ){

  150563.     p->yystack = pNew;

  150564.     p->yytos = &p->yystack[idx];

  150565. #ifndef NDEBUG

  150566.     if( yyTraceFILE ){

  150567.       fprintf(yyTraceFILE,"%sStack grows from %d to %d entries.\n",

  150568.               yyTracePrompt, p->yystksz, newSize);

  150569.     }

  150570. #endif

  150571.     p->yystksz = newSize;

  150572.   }

  150573.   return pNew==0; 

  150574. }

  150575. #endif

  150576. 

  150577. /* Datatype of the argument to the memory allocated passed as the

  150578. ** second argument to sqlite3ParserAlloc() below.  This can be changed by

  150579. ** putting an appropriate #define in the %include section of the input

  150580. ** grammar.

  150581. */

  150582. #ifndef YYMALLOCARGTYPE

  150583. # define YYMALLOCARGTYPE size_t

  150584. #endif

  150585. 

  150586. /* Initialize a new parser that has already been allocated.

  150587. */

  150588. SQLITE_PRIVATE void sqlite3ParserInit(void *yypRawParser sqlite3ParserCTX_PDECL){

  150589.   yyParser *yypParser = (yyParser*)yypRawParser;

  150590.   sqlite3ParserCTX_STORE

  150591. #ifdef YYTRACKMAXSTACKDEPTH

  150592.   yypParser->yyhwm = 0;

  150593. #endif

  150594. #if YYSTACKDEPTH<=0

  150595.   yypParser->yytos = NULL;

  150596.   yypParser->yystack = NULL;

  150597.   yypParser->yystksz = 0;

  150598.   if( yyGrowStack(yypParser) ){

  150599.     yypParser->yystack = &yypParser->yystk0;

  150600.     yypParser->yystksz = 1;

  150601.   }

  150602. #endif

  150603. #ifndef YYNOERRORRECOVERY

  150604.   yypParser->yyerrcnt = -1;

  150605. #endif

  150606.   yypParser->yytos = yypParser->yystack;

  150607.   yypParser->yystack[0].stateno = 0;

  150608.   yypParser->yystack[0].major = 0;

  150609. #if YYSTACKDEPTH>0

  150610.   yypParser->yystackEnd = &yypParser->yystack[YYSTACKDEPTH-1];

  150611. #endif

  150612. }

  150613. 

  150614. #ifndef sqlite3Parser_ENGINEALWAYSONSTACK

  150615. /* 

  150616. ** This function allocates a new parser.

  150617. ** The only argument is a pointer to a function which works like

  150618. ** malloc.

  150619. **

  150620. ** Inputs:

  150621. ** A pointer to the function used to allocate memory.

  150622. **

  150623. ** Outputs:

  150624. ** A pointer to a parser.  This pointer is used in subsequent calls

  150625. ** to sqlite3Parser and sqlite3ParserFree.

  150626. */

  150627. SQLITE_PRIVATE void *sqlite3ParserAlloc(void *(*mallocProc)(YYMALLOCARGTYPE) sqlite3ParserCTX_PDECL){

  150628.   yyParser *yypParser;

  150629.   yypParser = (yyParser*)(*mallocProc)( (YYMALLOCARGTYPE)sizeof(yyParser) );

  150630.   if( yypParser ){

  150631.     sqlite3ParserCTX_STORE

  150632.     sqlite3ParserInit(yypParser sqlite3ParserCTX_PARAM);

  150633.   }

  150634.   return (void*)yypParser;

  150635. }

  150636. #endif /* sqlite3Parser_ENGINEALWAYSONSTACK */

  150637. 

  150638. 

  150639. /* The following function deletes the "minor type" or semantic value

  150640. ** associated with a symbol.  The symbol can be either a terminal

  150641. ** or nonterminal. "yymajor" is the symbol code, and "yypminor" is

  150642. ** a pointer to the value to be deleted.  The code used to do the 

  150643. ** deletions is derived from the %destructor and/or %token_destructor

  150644. ** directives of the input grammar.

  150645. */

  150646. static void yy_destructor(

  150647.   yyParser *yypParser,    /* The parser */

  150648.   YYCODETYPE yymajor,     /* Type code for object to destroy */

  150649.   YYMINORTYPE *yypminor   /* The object to be destroyed */

  150650. ){

  150651.   sqlite3ParserARG_FETCH

  150652.   sqlite3ParserCTX_FETCH

  150653.   switch( yymajor ){

  150654.     /* Here is inserted the actions which take place when a

  150655.     ** terminal or non-terminal is destroyed.  This can happen

  150656.     ** when the symbol is popped from the stack during a

  150657.     ** reduce or during error processing or when a parser is 

  150658.     ** being destroyed before it is finished parsing.

  150659.     **

  150660.     ** Note: during a reduce, the only symbols destroyed are those

  150661.     ** which appear on the RHS of the rule, but which are *not* used

  150662.     ** inside the C code.

  150663.     */

  150664. /********* Begin destructor definitions ***************************************/

  150665.     case 195: /* select */

  150666.     case 228: /* selectnowith */

  150667.     case 229: /* oneselect */

  150668.     case 241: /* values */

  150669. {

  150670. sqlite3SelectDelete(pParse->db, (yypminor->yy391));

  150671. }

  150672.       break;

  150673.     case 206: /* term */

  150674.     case 207: /* expr */

  150675.     case 235: /* where_opt */

  150676.     case 237: /* having_opt */

  150677.     case 249: /* on_opt */

  150678.     case 264: /* case_operand */

  150679.     case 266: /* case_else */

  150680.     case 269: /* vinto */

  150681.     case 276: /* when_clause */

  150682.     case 281: /* key_opt */

  150683.     case 295: /* filter_opt */

  150684. {

  150685. sqlite3ExprDelete(pParse->db, (yypminor->yy102));

  150686. }

  150687.       break;

  150688.     case 211: /* eidlist_opt */

  150689.     case 220: /* sortlist */

  150690.     case 221: /* eidlist */

  150691.     case 233: /* selcollist */

  150692.     case 236: /* groupby_opt */

  150693.     case 238: /* orderby_opt */

  150694.     case 242: /* nexprlist */

  150695.     case 243: /* sclp */

  150696.     case 251: /* exprlist */

  150697.     case 255: /* setlist */

  150698.     case 263: /* paren_exprlist */

  150699.     case 265: /* case_exprlist */

  150700.     case 294: /* part_opt */

  150701. {

  150702. sqlite3ExprListDelete(pParse->db, (yypminor->yy94));

  150703. }

  150704.       break;

  150705.     case 227: /* fullname */

  150706.     case 234: /* from */

  150707.     case 245: /* seltablist */

  150708.     case 246: /* stl_prefix */

  150709.     case 252: /* xfullname */

  150710. {

  150711. sqlite3SrcListDelete(pParse->db, (yypminor->yy407));

  150712. }

  150713.       break;

  150714.     case 230: /* wqlist */

  150715. {

  150716. sqlite3WithDelete(pParse->db, (yypminor->yy243));

  150717. }

  150718.       break;

  150719.     case 240: /* window_clause */

  150720.     case 290: /* windowdefn_list */

  150721. {

  150722. sqlite3WindowListDelete(pParse->db, (yypminor->yy379));

  150723. }

  150724.       break;

  150725.     case 250: /* using_opt */

  150726.     case 253: /* idlist */

  150727.     case 257: /* idlist_opt */

  150728. {

  150729. sqlite3IdListDelete(pParse->db, (yypminor->yy76));

  150730. }

  150731.       break;

  150732.     case 259: /* over_clause */

  150733.     case 291: /* windowdefn */

  150734.     case 292: /* window */

  150735.     case 293: /* frame_opt */

  150736. {

  150737. sqlite3WindowDelete(pParse->db, (yypminor->yy379));

  150738. }

  150739.       break;

  150740.     case 272: /* trigger_cmd_list */

  150741.     case 277: /* trigger_cmd */

  150742. {

  150743. sqlite3DeleteTriggerStep(pParse->db, (yypminor->yy11));

  150744. }

  150745.       break;

  150746.     case 274: /* trigger_event */

  150747. {

  150748. sqlite3IdListDelete(pParse->db, (yypminor->yy298).b);

  150749. }

  150750.       break;

  150751.     case 297: /* frame_bound */

  150752.     case 298: /* frame_bound_s */

  150753.     case 299: /* frame_bound_e */

  150754. {

  150755. sqlite3ExprDelete(pParse->db, (yypminor->yy389).pExpr);

  150756. }

  150757.       break;

  150758. /********* End destructor definitions *****************************************/

  150759.     default:  break;   /* If no destructor action specified: do nothing */

  150760.   }

  150761. }

  150762. 

  150763. /*

  150764. ** Pop the parser's stack once.

  150765. **

  150766. ** If there is a destructor routine associated with the token which

  150767. ** is popped from the stack, then call it.

  150768. */

  150769. static void yy_pop_parser_stack(yyParser *pParser){

  150770.   yyStackEntry *yytos;

  150771.   assert( pParser->yytos!=0 );

  150772.   assert( pParser->yytos > pParser->yystack );

  150773.   yytos = pParser->yytos--;

  150774. #ifndef NDEBUG

  150775.   if( yyTraceFILE ){

  150776.     fprintf(yyTraceFILE,"%sPopping %s\n",

  150777.       yyTracePrompt,

  150778.       yyTokenName[yytos->major]);

  150779.   }

  150780. #endif

  150781.   yy_destructor(pParser, yytos->major, &yytos->minor);

  150782. }

  150783. 

  150784. /*

  150785. ** Clear all secondary memory allocations from the parser

  150786. */

  150787. SQLITE_PRIVATE void sqlite3ParserFinalize(void *p){

  150788.   yyParser *pParser = (yyParser*)p;

  150789.   while( pParser->yytos>pParser->yystack ) yy_pop_parser_stack(pParser);

  150790. #if YYSTACKDEPTH<=0

  150791.   if( pParser->yystack!=&pParser->yystk0 ) free(pParser->yystack);

  150792. #endif

  150793. }

  150794. 

  150795. #ifndef sqlite3Parser_ENGINEALWAYSONSTACK

  150796. /* 

  150797. ** Deallocate and destroy a parser.  Destructors are called for

  150798. ** all stack elements before shutting the parser down.

  150799. **

  150800. ** If the YYPARSEFREENEVERNULL macro exists (for example because it

  150801. ** is defined in a %include section of the input grammar) then it is

  150802. ** assumed that the input pointer is never NULL.

  150803. */

  150804. SQLITE_PRIVATE void sqlite3ParserFree(

  150805.   void *p,                    /* The parser to be deleted */

  150806.   void (*freeProc)(void*)     /* Function used to reclaim memory */

  150807. ){

  150808. #ifndef YYPARSEFREENEVERNULL

  150809.   if( p==0 ) return;

  150810. #endif

  150811.   sqlite3ParserFinalize(p);

  150812.   (*freeProc)(p);

  150813. }

  150814. #endif /* sqlite3Parser_ENGINEALWAYSONSTACK */

  150815. 

  150816. /*

  150817. ** Return the peak depth of the stack for a parser.

  150818. */

  150819. #ifdef YYTRACKMAXSTACKDEPTH

  150820. SQLITE_PRIVATE int sqlite3ParserStackPeak(void *p){

  150821.   yyParser *pParser = (yyParser*)p;

  150822.   return pParser->yyhwm;

  150823. }

  150824. #endif

  150825. 

  150826. /* This array of booleans keeps track of the parser statement

  150827. ** coverage.  The element yycoverage[X][Y] is set when the parser

  150828. ** is in state X and has a lookahead token Y.  In a well-tested

  150829. ** systems, every element of this matrix should end up being set.

  150830. */

  150831. #if defined(YYCOVERAGE)

  150832. static unsigned char yycoverage[YYNSTATE][YYNTOKEN];

  150833. #endif

  150834. 

  150835. /*

  150836. ** Write into out a description of every state/lookahead combination that

  150837. **

  150838. **   (1)  has not been used by the parser, and

  150839. **   (2)  is not a syntax error.

  150840. **

  150841. ** Return the number of missed state/lookahead combinations.

  150842. */

  150843. #if defined(YYCOVERAGE)

  150844. SQLITE_PRIVATE int sqlite3ParserCoverage(FILE *out){

  150845.   int stateno, iLookAhead, i;

  150846.   int nMissed = 0;

  150847.   for(stateno=0; stateno<YYNSTATE; stateno++){

  150848.     i = yy_shift_ofst[stateno];

  150849.     for(iLookAhead=0; iLookAhead<YYNTOKEN; iLookAhead++){

  150850.       if( yy_lookahead[i+iLookAhead]!=iLookAhead ) continue;

  150851.       if( yycoverage[stateno][iLookAhead]==0 ) nMissed++;

  150852.       if( out ){

  150853.         fprintf(out,"State %d lookahead %s %s\n", stateno,

  150854.                 yyTokenName[iLookAhead],

  150855.                 yycoverage[stateno][iLookAhead] ? "ok" : "missed");

  150856.       }

  150857.     }

  150858.   }

  150859.   return nMissed;

  150860. }

  150861. #endif

  150862. 

  150863. /*

  150864. ** Find the appropriate action for a parser given the terminal

  150865. ** look-ahead token iLookAhead.

  150866. */

  150867. static YYACTIONTYPE yy_find_shift_action(

  150868.   YYCODETYPE iLookAhead,    /* The look-ahead token */

  150869.   YYACTIONTYPE stateno      /* Current state number */

  150870. ){

  150871.   int i;

  150872. 

  150873.   if( stateno>YY_MAX_SHIFT ) return stateno;

  150874.   assert( stateno <= YY_SHIFT_COUNT );

  150875. #if defined(YYCOVERAGE)

  150876.   yycoverage[stateno][iLookAhead] = 1;

  150877. #endif

  150878.   do{

  150879.     i = yy_shift_ofst[stateno];

  150880.     assert( i>=0 );

  150881.     /* assert( i+YYNTOKEN<=(int)YY_NLOOKAHEAD ); */

  150882.     assert( iLookAhead!=YYNOCODE );

  150883.     assert( iLookAhead < YYNTOKEN );

  150884.     i += iLookAhead;

  150885.     if( i>=YY_NLOOKAHEAD || yy_lookahead[i]!=iLookAhead ){

  150886. #ifdef YYFALLBACK

  150887.       YYCODETYPE iFallback;            /* Fallback token */

  150888.       if( iLookAhead<sizeof(yyFallback)/sizeof(yyFallback[0])

  150889.              && (iFallback = yyFallback[iLookAhead])!=0 ){

  150890. #ifndef NDEBUG

  150891.         if( yyTraceFILE ){

  150892.           fprintf(yyTraceFILE, "%sFALLBACK %s => %s\n",

  150893.              yyTracePrompt, yyTokenName[iLookAhead], yyTokenName[iFallback]);

  150894.         }

  150895. #endif

  150896.         assert( yyFallback[iFallback]==0 ); /* Fallback loop must terminate */

  150897.         iLookAhead = iFallback;

  150898.         continue;

  150899.       }

  150900. #endif

  150901. #ifdef YYWILDCARD

  150902.       {

  150903.         int j = i - iLookAhead + YYWILDCARD;

  150904.         if( 

  150905. #if YY_SHIFT_MIN+YYWILDCARD<0

  150906.           j>=0 &&

  150907. #endif

  150908. #if YY_SHIFT_MAX+YYWILDCARD>=YY_ACTTAB_COUNT

  150909.           j<YY_ACTTAB_COUNT &&

  150910. #endif

  150911.           j<(int)(sizeof(yy_lookahead)/sizeof(yy_lookahead[0])) &&

  150912.           yy_lookahead[j]==YYWILDCARD && iLookAhead>0

  150913.         ){

  150914. #ifndef NDEBUG

  150915.           if( yyTraceFILE ){

  150916.             fprintf(yyTraceFILE, "%sWILDCARD %s => %s\n",

  150917.                yyTracePrompt, yyTokenName[iLookAhead],

  150918.                yyTokenName[YYWILDCARD]);

  150919.           }

  150920. #endif /* NDEBUG */

  150921.           return yy_action[j];

  150922.         }

  150923.       }

  150924. #endif /* YYWILDCARD */

  150925.       return yy_default[stateno];

  150926.     }else{

  150927.       return yy_action[i];

  150928.     }

  150929.   }while(1);

  150930. }

  150931. 

  150932. /*

  150933. ** Find the appropriate action for a parser given the non-terminal

  150934. ** look-ahead token iLookAhead.

  150935. */

  150936. static YYACTIONTYPE yy_find_reduce_action(

  150937.   YYACTIONTYPE stateno,     /* Current state number */

  150938.   YYCODETYPE iLookAhead     /* The look-ahead token */

  150939. ){

  150940.   int i;

  150941. #ifdef YYERRORSYMBOL

  150942.   if( stateno>YY_REDUCE_COUNT ){

  150943.     return yy_default[stateno];

  150944.   }

  150945. #else

  150946.   assert( stateno<=YY_REDUCE_COUNT );

  150947. #endif

  150948.   i = yy_reduce_ofst[stateno];

  150949.   assert( iLookAhead!=YYNOCODE );

  150950.   i += iLookAhead;

  150951. #ifdef YYERRORSYMBOL

  150952.   if( i<0 || i>=YY_ACTTAB_COUNT || yy_lookahead[i]!=iLookAhead ){

  150953.     return yy_default[stateno];

  150954.   }

  150955. #else

  150956.   assert( i>=0 && i<YY_ACTTAB_COUNT );

  150957.   assert( yy_lookahead[i]==iLookAhead );

  150958. #endif

  150959.   return yy_action[i];

  150960. }

  150961. 

  150962. /*

  150963. ** The following routine is called if the stack overflows.

  150964. */

  150965. static void yyStackOverflow(yyParser *yypParser){

  150966.    sqlite3ParserARG_FETCH

  150967.    sqlite3ParserCTX_FETCH

  150968. #ifndef NDEBUG

  150969.    if( yyTraceFILE ){

  150970.      fprintf(yyTraceFILE,"%sStack Overflow!\n",yyTracePrompt);

  150971.    }

  150972. #endif

  150973.    while( yypParser->yytos>yypParser->yystack ) yy_pop_parser_stack(yypParser);

  150974.    /* Here code is inserted which will execute if the parser

  150975.    ** stack every overflows */

  150976. /******** Begin %stack_overflow code ******************************************/

  150977. 

  150978.   sqlite3ErrorMsg(pParse, "parser stack overflow");

  150979. /******** End %stack_overflow code ********************************************/

  150980.    sqlite3ParserARG_STORE /* Suppress warning about unused %extra_argument var */

  150981.    sqlite3ParserCTX_STORE

  150982. }

  150983. 

  150984. /*

  150985. ** Print tracing information for a SHIFT action

  150986. */

  150987. #ifndef NDEBUG

  150988. static void yyTraceShift(yyParser *yypParser, int yyNewState, const char *zTag){

  150989.   if( yyTraceFILE ){

  150990.     if( yyNewState<YYNSTATE ){

  150991.       fprintf(yyTraceFILE,"%s%s '%s', go to state %d\n",

  150992.          yyTracePrompt, zTag, yyTokenName[yypParser->yytos->major],

  150993.          yyNewState);

  150994.     }else{

  150995.       fprintf(yyTraceFILE,"%s%s '%s', pending reduce %d\n",

  150996.          yyTracePrompt, zTag, yyTokenName[yypParser->yytos->major],

  150997.          yyNewState - YY_MIN_REDUCE);

  150998.     }

  150999.   }

  151000. }

  151001. #else

  151002. # define yyTraceShift(X,Y,Z)

  151003. #endif

  151004. 

  151005. /*

  151006. ** Perform a shift action.

  151007. */

  151008. static void yy_shift(

  151009.   yyParser *yypParser,          /* The parser to be shifted */

  151010.   YYACTIONTYPE yyNewState,      /* The new state to shift in */

  151011.   YYCODETYPE yyMajor,           /* The major token to shift in */

  151012.   sqlite3ParserTOKENTYPE yyMinor        /* The minor token to shift in */

  151013. ){

  151014.   yyStackEntry *yytos;

  151015.   yypParser->yytos++;

  151016. #ifdef YYTRACKMAXSTACKDEPTH

  151017.   if( (int)(yypParser->yytos - yypParser->yystack)>yypParser->yyhwm ){

  151018.     yypParser->yyhwm++;

  151019.     assert( yypParser->yyhwm == (int)(yypParser->yytos - yypParser->yystack) );

  151020.   }

  151021. #endif

  151022. #if YYSTACKDEPTH>0 

  151023.   if( yypParser->yytos>yypParser->yystackEnd ){

  151024.     yypParser->yytos--;

  151025.     yyStackOverflow(yypParser);

  151026.     return;

  151027.   }

  151028. #else

  151029.   if( yypParser->yytos>=&yypParser->yystack[yypParser->yystksz] ){

  151030.     if( yyGrowStack(yypParser) ){

  151031.       yypParser->yytos--;

  151032.       yyStackOverflow(yypParser);

  151033.       return;

  151034.     }

  151035.   }

  151036. #endif

  151037.   if( yyNewState > YY_MAX_SHIFT ){

  151038.     yyNewState += YY_MIN_REDUCE - YY_MIN_SHIFTREDUCE;

  151039.   }

  151040.   yytos = yypParser->yytos;

  151041.   yytos->stateno = yyNewState;

  151042.   yytos->major = yyMajor;

  151043.   yytos->minor.yy0 = yyMinor;

  151044.   yyTraceShift(yypParser, yyNewState, "Shift");

  151045. }

  151046. 

  151047. /* For rule J, yyRuleInfoLhs[J] contains the symbol on the left-hand side

  151048. ** of that rule */

  151049. static const YYCODETYPE yyRuleInfoLhs[] = {

  151050.    180,  /* (0) explain ::= EXPLAIN */

  151051.    180,  /* (1) explain ::= EXPLAIN QUERY PLAN */

  151052.    179,  /* (2) cmdx ::= cmd */

  151053.    181,  /* (3) cmd ::= BEGIN transtype trans_opt */

  151054.    182,  /* (4) transtype ::= */

  151055.    182,  /* (5) transtype ::= DEFERRED */

  151056.    182,  /* (6) transtype ::= IMMEDIATE */

  151057.    182,  /* (7) transtype ::= EXCLUSIVE */

  151058.    181,  /* (8) cmd ::= COMMIT|END trans_opt */

  151059.    181,  /* (9) cmd ::= ROLLBACK trans_opt */

  151060.    181,  /* (10) cmd ::= SAVEPOINT nm */

  151061.    181,  /* (11) cmd ::= RELEASE savepoint_opt nm */

  151062.    181,  /* (12) cmd ::= ROLLBACK trans_opt TO savepoint_opt nm */

  151063.    186,  /* (13) create_table ::= createkw temp TABLE ifnotexists nm dbnm */

  151064.    188,  /* (14) createkw ::= CREATE */

  151065.    190,  /* (15) ifnotexists ::= */

  151066.    190,  /* (16) ifnotexists ::= IF NOT EXISTS */

  151067.    189,  /* (17) temp ::= TEMP */

  151068.    189,  /* (18) temp ::= */

  151069.    187,  /* (19) create_table_args ::= LP columnlist conslist_opt RP table_options */

  151070.    187,  /* (20) create_table_args ::= AS select */

  151071.    194,  /* (21) table_options ::= */

  151072.    194,  /* (22) table_options ::= WITHOUT nm */

  151073.    196,  /* (23) columnname ::= nm typetoken */

  151074.    198,  /* (24) typetoken ::= */

  151075.    198,  /* (25) typetoken ::= typename LP signed RP */

  151076.    198,  /* (26) typetoken ::= typename LP signed COMMA signed RP */

  151077.    199,  /* (27) typename ::= typename ID|STRING */

  151078.    203,  /* (28) scanpt ::= */

  151079.    204,  /* (29) scantok ::= */

  151080.    205,  /* (30) ccons ::= CONSTRAINT nm */

  151081.    205,  /* (31) ccons ::= DEFAULT scantok term */

  151082.    205,  /* (32) ccons ::= DEFAULT LP expr RP */

  151083.    205,  /* (33) ccons ::= DEFAULT PLUS scantok term */

  151084.    205,  /* (34) ccons ::= DEFAULT MINUS scantok term */

  151085.    205,  /* (35) ccons ::= DEFAULT scantok ID|INDEXED */

  151086.    205,  /* (36) ccons ::= NOT NULL onconf */

  151087.    205,  /* (37) ccons ::= PRIMARY KEY sortorder onconf autoinc */

  151088.    205,  /* (38) ccons ::= UNIQUE onconf */

  151089.    205,  /* (39) ccons ::= CHECK LP expr RP */

  151090.    205,  /* (40) ccons ::= REFERENCES nm eidlist_opt refargs */

  151091.    205,  /* (41) ccons ::= defer_subclause */

  151092.    205,  /* (42) ccons ::= COLLATE ID|STRING */

  151093.    210,  /* (43) autoinc ::= */

  151094.    210,  /* (44) autoinc ::= AUTOINCR */

  151095.    212,  /* (45) refargs ::= */

  151096.    212,  /* (46) refargs ::= refargs refarg */

  151097.    214,  /* (47) refarg ::= MATCH nm */

  151098.    214,  /* (48) refarg ::= ON INSERT refact */

  151099.    214,  /* (49) refarg ::= ON DELETE refact */

  151100.    214,  /* (50) refarg ::= ON UPDATE refact */

  151101.    215,  /* (51) refact ::= SET NULL */

  151102.    215,  /* (52) refact ::= SET DEFAULT */

  151103.    215,  /* (53) refact ::= CASCADE */

  151104.    215,  /* (54) refact ::= RESTRICT */

  151105.    215,  /* (55) refact ::= NO ACTION */

  151106.    213,  /* (56) defer_subclause ::= NOT DEFERRABLE init_deferred_pred_opt */

  151107.    213,  /* (57) defer_subclause ::= DEFERRABLE init_deferred_pred_opt */

  151108.    216,  /* (58) init_deferred_pred_opt ::= */

  151109.    216,  /* (59) init_deferred_pred_opt ::= INITIALLY DEFERRED */

  151110.    216,  /* (60) init_deferred_pred_opt ::= INITIALLY IMMEDIATE */

  151111.    193,  /* (61) conslist_opt ::= */

  151112.    218,  /* (62) tconscomma ::= COMMA */

  151113.    219,  /* (63) tcons ::= CONSTRAINT nm */

  151114.    219,  /* (64) tcons ::= PRIMARY KEY LP sortlist autoinc RP onconf */

  151115.    219,  /* (65) tcons ::= UNIQUE LP sortlist RP onconf */

  151116.    219,  /* (66) tcons ::= CHECK LP expr RP onconf */

  151117.    219,  /* (67) tcons ::= FOREIGN KEY LP eidlist RP REFERENCES nm eidlist_opt refargs defer_subclause_opt */

  151118.    222,  /* (68) defer_subclause_opt ::= */

  151119.    208,  /* (69) onconf ::= */

  151120.    208,  /* (70) onconf ::= ON CONFLICT resolvetype */

  151121.    223,  /* (71) orconf ::= */

  151122.    223,  /* (72) orconf ::= OR resolvetype */

  151123.    224,  /* (73) resolvetype ::= IGNORE */

  151124.    224,  /* (74) resolvetype ::= REPLACE */

  151125.    181,  /* (75) cmd ::= DROP TABLE ifexists fullname */

  151126.    226,  /* (76) ifexists ::= IF EXISTS */

  151127.    226,  /* (77) ifexists ::= */

  151128.    181,  /* (78) cmd ::= createkw temp VIEW ifnotexists nm dbnm eidlist_opt AS select */

  151129.    181,  /* (79) cmd ::= DROP VIEW ifexists fullname */

  151130.    181,  /* (80) cmd ::= select */

  151131.    195,  /* (81) select ::= WITH wqlist selectnowith */

  151132.    195,  /* (82) select ::= WITH RECURSIVE wqlist selectnowith */

  151133.    195,  /* (83) select ::= selectnowith */

  151134.    228,  /* (84) selectnowith ::= selectnowith multiselect_op oneselect */

  151135.    231,  /* (85) multiselect_op ::= UNION */

  151136.    231,  /* (86) multiselect_op ::= UNION ALL */

  151137.    231,  /* (87) multiselect_op ::= EXCEPT|INTERSECT */

  151138.    229,  /* (88) oneselect ::= SELECT distinct selcollist from where_opt groupby_opt having_opt orderby_opt limit_opt */

  151139.    229,  /* (89) oneselect ::= SELECT distinct selcollist from where_opt groupby_opt having_opt window_clause orderby_opt limit_opt */

  151140.    241,  /* (90) values ::= VALUES LP nexprlist RP */

  151141.    241,  /* (91) values ::= values COMMA LP nexprlist RP */

  151142.    232,  /* (92) distinct ::= DISTINCT */

  151143.    232,  /* (93) distinct ::= ALL */

  151144.    232,  /* (94) distinct ::= */

  151145.    243,  /* (95) sclp ::= */

  151146.    233,  /* (96) selcollist ::= sclp scanpt expr scanpt as */

  151147.    233,  /* (97) selcollist ::= sclp scanpt STAR */

  151148.    233,  /* (98) selcollist ::= sclp scanpt nm DOT STAR */

  151149.    244,  /* (99) as ::= AS nm */

  151150.    244,  /* (100) as ::= */

  151151.    234,  /* (101) from ::= */

  151152.    234,  /* (102) from ::= FROM seltablist */

  151153.    246,  /* (103) stl_prefix ::= seltablist joinop */

  151154.    246,  /* (104) stl_prefix ::= */

  151155.    245,  /* (105) seltablist ::= stl_prefix nm dbnm as indexed_opt on_opt using_opt */

  151156.    245,  /* (106) seltablist ::= stl_prefix nm dbnm LP exprlist RP as on_opt using_opt */

  151157.    245,  /* (107) seltablist ::= stl_prefix LP select RP as on_opt using_opt */

  151158.    245,  /* (108) seltablist ::= stl_prefix LP seltablist RP as on_opt using_opt */

  151159.    191,  /* (109) dbnm ::= */

  151160.    191,  /* (110) dbnm ::= DOT nm */

  151161.    227,  /* (111) fullname ::= nm */

  151162.    227,  /* (112) fullname ::= nm DOT nm */

  151163.    252,  /* (113) xfullname ::= nm */

  151164.    252,  /* (114) xfullname ::= nm DOT nm */

  151165.    252,  /* (115) xfullname ::= nm DOT nm AS nm */

  151166.    252,  /* (116) xfullname ::= nm AS nm */

  151167.    247,  /* (117) joinop ::= COMMA|JOIN */

  151168.    247,  /* (118) joinop ::= JOIN_KW JOIN */

  151169.    247,  /* (119) joinop ::= JOIN_KW nm JOIN */

  151170.    247,  /* (120) joinop ::= JOIN_KW nm nm JOIN */

  151171.    249,  /* (121) on_opt ::= ON expr */

  151172.    249,  /* (122) on_opt ::= */

  151173.    248,  /* (123) indexed_opt ::= */

  151174.    248,  /* (124) indexed_opt ::= INDEXED BY nm */

  151175.    248,  /* (125) indexed_opt ::= NOT INDEXED */

  151176.    250,  /* (126) using_opt ::= USING LP idlist RP */

  151177.    250,  /* (127) using_opt ::= */

  151178.    238,  /* (128) orderby_opt ::= */

  151179.    238,  /* (129) orderby_opt ::= ORDER BY sortlist */

  151180.    220,  /* (130) sortlist ::= sortlist COMMA expr sortorder */

  151181.    220,  /* (131) sortlist ::= expr sortorder */

  151182.    209,  /* (132) sortorder ::= ASC */

  151183.    209,  /* (133) sortorder ::= DESC */

  151184.    209,  /* (134) sortorder ::= */

  151185.    236,  /* (135) groupby_opt ::= */

  151186.    236,  /* (136) groupby_opt ::= GROUP BY nexprlist */

  151187.    237,  /* (137) having_opt ::= */

  151188.    237,  /* (138) having_opt ::= HAVING expr */

  151189.    239,  /* (139) limit_opt ::= */

  151190.    239,  /* (140) limit_opt ::= LIMIT expr */

  151191.    239,  /* (141) limit_opt ::= LIMIT expr OFFSET expr */

  151192.    239,  /* (142) limit_opt ::= LIMIT expr COMMA expr */

  151193.    181,  /* (143) cmd ::= with DELETE FROM xfullname indexed_opt where_opt */

  151194.    235,  /* (144) where_opt ::= */

  151195.    235,  /* (145) where_opt ::= WHERE expr */

  151196.    181,  /* (146) cmd ::= with UPDATE orconf xfullname indexed_opt SET setlist where_opt */

  151197.    255,  /* (147) setlist ::= setlist COMMA nm EQ expr */

  151198.    255,  /* (148) setlist ::= setlist COMMA LP idlist RP EQ expr */

  151199.    255,  /* (149) setlist ::= nm EQ expr */

  151200.    255,  /* (150) setlist ::= LP idlist RP EQ expr */

  151201.    181,  /* (151) cmd ::= with insert_cmd INTO xfullname idlist_opt select upsert */

  151202.    181,  /* (152) cmd ::= with insert_cmd INTO xfullname idlist_opt DEFAULT VALUES */

  151203.    258,  /* (153) upsert ::= */

  151204.    258,  /* (154) upsert ::= ON CONFLICT LP sortlist RP where_opt DO UPDATE SET setlist where_opt */

  151205.    258,  /* (155) upsert ::= ON CONFLICT LP sortlist RP where_opt DO NOTHING */

  151206.    258,  /* (156) upsert ::= ON CONFLICT DO NOTHING */

  151207.    256,  /* (157) insert_cmd ::= INSERT orconf */

  151208.    256,  /* (158) insert_cmd ::= REPLACE */

  151209.    257,  /* (159) idlist_opt ::= */

  151210.    257,  /* (160) idlist_opt ::= LP idlist RP */

  151211.    253,  /* (161) idlist ::= idlist COMMA nm */

  151212.    253,  /* (162) idlist ::= nm */

  151213.    207,  /* (163) expr ::= LP expr RP */

  151214.    207,  /* (164) expr ::= ID|INDEXED */

  151215.    207,  /* (165) expr ::= JOIN_KW */

  151216.    207,  /* (166) expr ::= nm DOT nm */

  151217.    207,  /* (167) expr ::= nm DOT nm DOT nm */

  151218.    206,  /* (168) term ::= NULL|FLOAT|BLOB */

  151219.    206,  /* (169) term ::= STRING */

  151220.    206,  /* (170) term ::= INTEGER */

  151221.    207,  /* (171) expr ::= VARIABLE */

  151222.    207,  /* (172) expr ::= expr COLLATE ID|STRING */

  151223.    207,  /* (173) expr ::= CAST LP expr AS typetoken RP */

  151224.    207,  /* (174) expr ::= ID|INDEXED LP distinct exprlist RP */

  151225.    207,  /* (175) expr ::= ID|INDEXED LP STAR RP */

  151226.    207,  /* (176) expr ::= ID|INDEXED LP distinct exprlist RP over_clause */

  151227.    207,  /* (177) expr ::= ID|INDEXED LP STAR RP over_clause */

  151228.    206,  /* (178) term ::= CTIME_KW */

  151229.    207,  /* (179) expr ::= LP nexprlist COMMA expr RP */

  151230.    207,  /* (180) expr ::= expr AND expr */

  151231.    207,  /* (181) expr ::= expr OR expr */

  151232.    207,  /* (182) expr ::= expr LT|GT|GE|LE expr */

  151233.    207,  /* (183) expr ::= expr EQ|NE expr */

  151234.    207,  /* (184) expr ::= expr BITAND|BITOR|LSHIFT|RSHIFT expr */

  151235.    207,  /* (185) expr ::= expr PLUS|MINUS expr */

  151236.    207,  /* (186) expr ::= expr STAR|SLASH|REM expr */

  151237.    207,  /* (187) expr ::= expr CONCAT expr */

  151238.    260,  /* (188) likeop ::= NOT LIKE_KW|MATCH */

  151239.    207,  /* (189) expr ::= expr likeop expr */

  151240.    207,  /* (190) expr ::= expr likeop expr ESCAPE expr */

  151241.    207,  /* (191) expr ::= expr ISNULL|NOTNULL */

  151242.    207,  /* (192) expr ::= expr NOT NULL */

  151243.    207,  /* (193) expr ::= expr IS expr */

  151244.    207,  /* (194) expr ::= expr IS NOT expr */

  151245.    207,  /* (195) expr ::= NOT expr */

  151246.    207,  /* (196) expr ::= BITNOT expr */

  151247.    207,  /* (197) expr ::= PLUS|MINUS expr */

  151248.    261,  /* (198) between_op ::= BETWEEN */

  151249.    261,  /* (199) between_op ::= NOT BETWEEN */

  151250.    207,  /* (200) expr ::= expr between_op expr AND expr */

  151251.    262,  /* (201) in_op ::= IN */

  151252.    262,  /* (202) in_op ::= NOT IN */

  151253.    207,  /* (203) expr ::= expr in_op LP exprlist RP */

  151254.    207,  /* (204) expr ::= LP select RP */

  151255.    207,  /* (205) expr ::= expr in_op LP select RP */

  151256.    207,  /* (206) expr ::= expr in_op nm dbnm paren_exprlist */

  151257.    207,  /* (207) expr ::= EXISTS LP select RP */

  151258.    207,  /* (208) expr ::= CASE case_operand case_exprlist case_else END */

  151259.    265,  /* (209) case_exprlist ::= case_exprlist WHEN expr THEN expr */

  151260.    265,  /* (210) case_exprlist ::= WHEN expr THEN expr */

  151261.    266,  /* (211) case_else ::= ELSE expr */

  151262.    266,  /* (212) case_else ::= */

  151263.    264,  /* (213) case_operand ::= expr */

  151264.    264,  /* (214) case_operand ::= */

  151265.    251,  /* (215) exprlist ::= */

  151266.    242,  /* (216) nexprlist ::= nexprlist COMMA expr */

  151267.    242,  /* (217) nexprlist ::= expr */

  151268.    263,  /* (218) paren_exprlist ::= */

  151269.    263,  /* (219) paren_exprlist ::= LP exprlist RP */

  151270.    181,  /* (220) cmd ::= createkw uniqueflag INDEX ifnotexists nm dbnm ON nm LP sortlist RP where_opt */

  151271.    267,  /* (221) uniqueflag ::= UNIQUE */

  151272.    267,  /* (222) uniqueflag ::= */

  151273.    211,  /* (223) eidlist_opt ::= */

  151274.    211,  /* (224) eidlist_opt ::= LP eidlist RP */

  151275.    221,  /* (225) eidlist ::= eidlist COMMA nm collate sortorder */

  151276.    221,  /* (226) eidlist ::= nm collate sortorder */

  151277.    268,  /* (227) collate ::= */

  151278.    268,  /* (228) collate ::= COLLATE ID|STRING */

  151279.    181,  /* (229) cmd ::= DROP INDEX ifexists fullname */

  151280.    181,  /* (230) cmd ::= VACUUM vinto */

  151281.    181,  /* (231) cmd ::= VACUUM nm vinto */

  151282.    269,  /* (232) vinto ::= INTO expr */

  151283.    269,  /* (233) vinto ::= */

  151284.    181,  /* (234) cmd ::= PRAGMA nm dbnm */

  151285.    181,  /* (235) cmd ::= PRAGMA nm dbnm EQ nmnum */

  151286.    181,  /* (236) cmd ::= PRAGMA nm dbnm LP nmnum RP */

  151287.    181,  /* (237) cmd ::= PRAGMA nm dbnm EQ minus_num */

  151288.    181,  /* (238) cmd ::= PRAGMA nm dbnm LP minus_num RP */

  151289.    201,  /* (239) plus_num ::= PLUS INTEGER|FLOAT */

  151290.    202,  /* (240) minus_num ::= MINUS INTEGER|FLOAT */

  151291.    181,  /* (241) cmd ::= createkw trigger_decl BEGIN trigger_cmd_list END */

  151292.    271,  /* (242) trigger_decl ::= temp TRIGGER ifnotexists nm dbnm trigger_time trigger_event ON fullname foreach_clause when_clause */

  151293.    273,  /* (243) trigger_time ::= BEFORE|AFTER */

  151294.    273,  /* (244) trigger_time ::= INSTEAD OF */

  151295.    273,  /* (245) trigger_time ::= */

  151296.    274,  /* (246) trigger_event ::= DELETE|INSERT */

  151297.    274,  /* (247) trigger_event ::= UPDATE */

  151298.    274,  /* (248) trigger_event ::= UPDATE OF idlist */

  151299.    276,  /* (249) when_clause ::= */

  151300.    276,  /* (250) when_clause ::= WHEN expr */

  151301.    272,  /* (251) trigger_cmd_list ::= trigger_cmd_list trigger_cmd SEMI */

  151302.    272,  /* (252) trigger_cmd_list ::= trigger_cmd SEMI */

  151303.    278,  /* (253) trnm ::= nm DOT nm */

  151304.    279,  /* (254) tridxby ::= INDEXED BY nm */

  151305.    279,  /* (255) tridxby ::= NOT INDEXED */

  151306.    277,  /* (256) trigger_cmd ::= UPDATE orconf trnm tridxby SET setlist where_opt scanpt */

  151307.    277,  /* (257) trigger_cmd ::= scanpt insert_cmd INTO trnm idlist_opt select upsert scanpt */

  151308.    277,  /* (258) trigger_cmd ::= DELETE FROM trnm tridxby where_opt scanpt */

  151309.    277,  /* (259) trigger_cmd ::= scanpt select scanpt */

  151310.    207,  /* (260) expr ::= RAISE LP IGNORE RP */

  151311.    207,  /* (261) expr ::= RAISE LP raisetype COMMA nm RP */

  151312.    225,  /* (262) raisetype ::= ROLLBACK */

  151313.    225,  /* (263) raisetype ::= ABORT */

  151314.    225,  /* (264) raisetype ::= FAIL */

  151315.    181,  /* (265) cmd ::= DROP TRIGGER ifexists fullname */

  151316.    181,  /* (266) cmd ::= ATTACH database_kw_opt expr AS expr key_opt */

  151317.    181,  /* (267) cmd ::= DETACH database_kw_opt expr */

  151318.    281,  /* (268) key_opt ::= */

  151319.    281,  /* (269) key_opt ::= KEY expr */

  151320.    181,  /* (270) cmd ::= REINDEX */

  151321.    181,  /* (271) cmd ::= REINDEX nm dbnm */

  151322.    181,  /* (272) cmd ::= ANALYZE */

  151323.    181,  /* (273) cmd ::= ANALYZE nm dbnm */

  151324.    181,  /* (274) cmd ::= ALTER TABLE fullname RENAME TO nm */

  151325.    181,  /* (275) cmd ::= ALTER TABLE add_column_fullname ADD kwcolumn_opt columnname carglist */

  151326.    282,  /* (276) add_column_fullname ::= fullname */

  151327.    181,  /* (277) cmd ::= ALTER TABLE fullname RENAME kwcolumn_opt nm TO nm */

  151328.    181,  /* (278) cmd ::= create_vtab */

  151329.    181,  /* (279) cmd ::= create_vtab LP vtabarglist RP */

  151330.    284,  /* (280) create_vtab ::= createkw VIRTUAL TABLE ifnotexists nm dbnm USING nm */

  151331.    286,  /* (281) vtabarg ::= */

  151332.    287,  /* (282) vtabargtoken ::= ANY */

  151333.    287,  /* (283) vtabargtoken ::= lp anylist RP */

  151334.    288,  /* (284) lp ::= LP */

  151335.    254,  /* (285) with ::= WITH wqlist */

  151336.    254,  /* (286) with ::= WITH RECURSIVE wqlist */

  151337.    230,  /* (287) wqlist ::= nm eidlist_opt AS LP select RP */

  151338.    230,  /* (288) wqlist ::= wqlist COMMA nm eidlist_opt AS LP select RP */

  151339.    290,  /* (289) windowdefn_list ::= windowdefn */

  151340.    290,  /* (290) windowdefn_list ::= windowdefn_list COMMA windowdefn */

  151341.    291,  /* (291) windowdefn ::= nm AS LP window RP */

  151342.    292,  /* (292) window ::= PARTITION BY nexprlist orderby_opt frame_opt */

  151343.    292,  /* (293) window ::= nm PARTITION BY nexprlist orderby_opt frame_opt */

  151344.    292,  /* (294) window ::= ORDER BY sortlist frame_opt */

  151345.    292,  /* (295) window ::= nm ORDER BY sortlist frame_opt */

  151346.    292,  /* (296) window ::= frame_opt */

  151347.    292,  /* (297) window ::= nm frame_opt */

  151348.    293,  /* (298) frame_opt ::= */

  151349.    293,  /* (299) frame_opt ::= range_or_rows frame_bound_s frame_exclude_opt */

  151350.    293,  /* (300) frame_opt ::= range_or_rows BETWEEN frame_bound_s AND frame_bound_e frame_exclude_opt */

  151351.    296,  /* (301) range_or_rows ::= RANGE|ROWS|GROUPS */

  151352.    298,  /* (302) frame_bound_s ::= frame_bound */

  151353.    298,  /* (303) frame_bound_s ::= UNBOUNDED PRECEDING */

  151354.    299,  /* (304) frame_bound_e ::= frame_bound */

  151355.    299,  /* (305) frame_bound_e ::= UNBOUNDED FOLLOWING */

  151356.    297,  /* (306) frame_bound ::= expr PRECEDING|FOLLOWING */

  151357.    297,  /* (307) frame_bound ::= CURRENT ROW */

  151358.    300,  /* (308) frame_exclude_opt ::= */

  151359.    300,  /* (309) frame_exclude_opt ::= EXCLUDE frame_exclude */

  151360.    301,  /* (310) frame_exclude ::= NO OTHERS */

  151361.    301,  /* (311) frame_exclude ::= CURRENT ROW */

  151362.    301,  /* (312) frame_exclude ::= GROUP|TIES */

  151363.    240,  /* (313) window_clause ::= WINDOW windowdefn_list */

  151364.    259,  /* (314) over_clause ::= filter_opt OVER LP window RP */

  151365.    259,  /* (315) over_clause ::= filter_opt OVER nm */

  151366.    295,  /* (316) filter_opt ::= */

  151367.    295,  /* (317) filter_opt ::= FILTER LP WHERE expr RP */

  151368.    176,  /* (318) input ::= cmdlist */

  151369.    177,  /* (319) cmdlist ::= cmdlist ecmd */

  151370.    177,  /* (320) cmdlist ::= ecmd */

  151371.    178,  /* (321) ecmd ::= SEMI */

  151372.    178,  /* (322) ecmd ::= cmdx SEMI */

  151373.    178,  /* (323) ecmd ::= explain cmdx */

  151374.    183,  /* (324) trans_opt ::= */

  151375.    183,  /* (325) trans_opt ::= TRANSACTION */

  151376.    183,  /* (326) trans_opt ::= TRANSACTION nm */

  151377.    185,  /* (327) savepoint_opt ::= SAVEPOINT */

  151378.    185,  /* (328) savepoint_opt ::= */

  151379.    181,  /* (329) cmd ::= create_table create_table_args */

  151380.    192,  /* (330) columnlist ::= columnlist COMMA columnname carglist */

  151381.    192,  /* (331) columnlist ::= columnname carglist */

  151382.    184,  /* (332) nm ::= ID|INDEXED */

  151383.    184,  /* (333) nm ::= STRING */

  151384.    184,  /* (334) nm ::= JOIN_KW */

  151385.    198,  /* (335) typetoken ::= typename */

  151386.    199,  /* (336) typename ::= ID|STRING */

  151387.    200,  /* (337) signed ::= plus_num */

  151388.    200,  /* (338) signed ::= minus_num */

  151389.    197,  /* (339) carglist ::= carglist ccons */

  151390.    197,  /* (340) carglist ::= */

  151391.    205,  /* (341) ccons ::= NULL onconf */

  151392.    193,  /* (342) conslist_opt ::= COMMA conslist */

  151393.    217,  /* (343) conslist ::= conslist tconscomma tcons */

  151394.    217,  /* (344) conslist ::= tcons */

  151395.    218,  /* (345) tconscomma ::= */

  151396.    222,  /* (346) defer_subclause_opt ::= defer_subclause */

  151397.    224,  /* (347) resolvetype ::= raisetype */

  151398.    228,  /* (348) selectnowith ::= oneselect */

  151399.    229,  /* (349) oneselect ::= values */

  151400.    243,  /* (350) sclp ::= selcollist COMMA */

  151401.    244,  /* (351) as ::= ID|STRING */

  151402.    207,  /* (352) expr ::= term */

  151403.    260,  /* (353) likeop ::= LIKE_KW|MATCH */

  151404.    251,  /* (354) exprlist ::= nexprlist */

  151405.    270,  /* (355) nmnum ::= plus_num */

  151406.    270,  /* (356) nmnum ::= nm */

  151407.    270,  /* (357) nmnum ::= ON */

  151408.    270,  /* (358) nmnum ::= DELETE */

  151409.    270,  /* (359) nmnum ::= DEFAULT */

  151410.    201,  /* (360) plus_num ::= INTEGER|FLOAT */

  151411.    275,  /* (361) foreach_clause ::= */

  151412.    275,  /* (362) foreach_clause ::= FOR EACH ROW */

  151413.    278,  /* (363) trnm ::= nm */

  151414.    279,  /* (364) tridxby ::= */

  151415.    280,  /* (365) database_kw_opt ::= DATABASE */

  151416.    280,  /* (366) database_kw_opt ::= */

  151417.    283,  /* (367) kwcolumn_opt ::= */

  151418.    283,  /* (368) kwcolumn_opt ::= COLUMNKW */

  151419.    285,  /* (369) vtabarglist ::= vtabarg */

  151420.    285,  /* (370) vtabarglist ::= vtabarglist COMMA vtabarg */

  151421.    286,  /* (371) vtabarg ::= vtabarg vtabargtoken */

  151422.    289,  /* (372) anylist ::= */

  151423.    289,  /* (373) anylist ::= anylist LP anylist RP */

  151424.    289,  /* (374) anylist ::= anylist ANY */

  151425.    254,  /* (375) with ::= */

  151426. };

  151427. 

  151428. /* For rule J, yyRuleInfoNRhs[J] contains the negative of the number

  151429. ** of symbols on the right-hand side of that rule. */

  151430. static const signed char yyRuleInfoNRhs[] = {

  151431.    -1,  /* (0) explain ::= EXPLAIN */

  151432.    -3,  /* (1) explain ::= EXPLAIN QUERY PLAN */

  151433.    -1,  /* (2) cmdx ::= cmd */

  151434.    -3,  /* (3) cmd ::= BEGIN transtype trans_opt */

  151435.     0,  /* (4) transtype ::= */

  151436.    -1,  /* (5) transtype ::= DEFERRED */

  151437.    -1,  /* (6) transtype ::= IMMEDIATE */

  151438.    -1,  /* (7) transtype ::= EXCLUSIVE */

  151439.    -2,  /* (8) cmd ::= COMMIT|END trans_opt */

  151440.    -2,  /* (9) cmd ::= ROLLBACK trans_opt */

  151441.    -2,  /* (10) cmd ::= SAVEPOINT nm */

  151442.    -3,  /* (11) cmd ::= RELEASE savepoint_opt nm */

  151443.    -5,  /* (12) cmd ::= ROLLBACK trans_opt TO savepoint_opt nm */

  151444.    -6,  /* (13) create_table ::= createkw temp TABLE ifnotexists nm dbnm */

  151445.    -1,  /* (14) createkw ::= CREATE */

  151446.     0,  /* (15) ifnotexists ::= */

  151447.    -3,  /* (16) ifnotexists ::= IF NOT EXISTS */

  151448.    -1,  /* (17) temp ::= TEMP */

  151449.     0,  /* (18) temp ::= */

  151450.    -5,  /* (19) create_table_args ::= LP columnlist conslist_opt RP table_options */

  151451.    -2,  /* (20) create_table_args ::= AS select */

  151452.     0,  /* (21) table_options ::= */

  151453.    -2,  /* (22) table_options ::= WITHOUT nm */

  151454.    -2,  /* (23) columnname ::= nm typetoken */

  151455.     0,  /* (24) typetoken ::= */

  151456.    -4,  /* (25) typetoken ::= typename LP signed RP */

  151457.    -6,  /* (26) typetoken ::= typename LP signed COMMA signed RP */

  151458.    -2,  /* (27) typename ::= typename ID|STRING */

  151459.     0,  /* (28) scanpt ::= */

  151460.     0,  /* (29) scantok ::= */

  151461.    -2,  /* (30) ccons ::= CONSTRAINT nm */

  151462.    -3,  /* (31) ccons ::= DEFAULT scantok term */

  151463.    -4,  /* (32) ccons ::= DEFAULT LP expr RP */

  151464.    -4,  /* (33) ccons ::= DEFAULT PLUS scantok term */

  151465.    -4,  /* (34) ccons ::= DEFAULT MINUS scantok term */

  151466.    -3,  /* (35) ccons ::= DEFAULT scantok ID|INDEXED */

  151467.    -3,  /* (36) ccons ::= NOT NULL onconf */

  151468.    -5,  /* (37) ccons ::= PRIMARY KEY sortorder onconf autoinc */

  151469.    -2,  /* (38) ccons ::= UNIQUE onconf */

  151470.    -4,  /* (39) ccons ::= CHECK LP expr RP */

  151471.    -4,  /* (40) ccons ::= REFERENCES nm eidlist_opt refargs */

  151472.    -1,  /* (41) ccons ::= defer_subclause */

  151473.    -2,  /* (42) ccons ::= COLLATE ID|STRING */

  151474.     0,  /* (43) autoinc ::= */

  151475.    -1,  /* (44) autoinc ::= AUTOINCR */

  151476.     0,  /* (45) refargs ::= */

  151477.    -2,  /* (46) refargs ::= refargs refarg */

  151478.    -2,  /* (47) refarg ::= MATCH nm */

  151479.    -3,  /* (48) refarg ::= ON INSERT refact */

  151480.    -3,  /* (49) refarg ::= ON DELETE refact */

  151481.    -3,  /* (50) refarg ::= ON UPDATE refact */

  151482.    -2,  /* (51) refact ::= SET NULL */

  151483.    -2,  /* (52) refact ::= SET DEFAULT */

  151484.    -1,  /* (53) refact ::= CASCADE */

  151485.    -1,  /* (54) refact ::= RESTRICT */

  151486.    -2,  /* (55) refact ::= NO ACTION */

  151487.    -3,  /* (56) defer_subclause ::= NOT DEFERRABLE init_deferred_pred_opt */

  151488.    -2,  /* (57) defer_subclause ::= DEFERRABLE init_deferred_pred_opt */

  151489.     0,  /* (58) init_deferred_pred_opt ::= */

  151490.    -2,  /* (59) init_deferred_pred_opt ::= INITIALLY DEFERRED */

  151491.    -2,  /* (60) init_deferred_pred_opt ::= INITIALLY IMMEDIATE */

  151492.     0,  /* (61) conslist_opt ::= */

  151493.    -1,  /* (62) tconscomma ::= COMMA */

  151494.    -2,  /* (63) tcons ::= CONSTRAINT nm */

  151495.    -7,  /* (64) tcons ::= PRIMARY KEY LP sortlist autoinc RP onconf */

  151496.    -5,  /* (65) tcons ::= UNIQUE LP sortlist RP onconf */

  151497.    -5,  /* (66) tcons ::= CHECK LP expr RP onconf */

  151498.   -10,  /* (67) tcons ::= FOREIGN KEY LP eidlist RP REFERENCES nm eidlist_opt refargs defer_subclause_opt */

  151499.     0,  /* (68) defer_subclause_opt ::= */

  151500.     0,  /* (69) onconf ::= */

  151501.    -3,  /* (70) onconf ::= ON CONFLICT resolvetype */

  151502.     0,  /* (71) orconf ::= */

  151503.    -2,  /* (72) orconf ::= OR resolvetype */

  151504.    -1,  /* (73) resolvetype ::= IGNORE */

  151505.    -1,  /* (74) resolvetype ::= REPLACE */

  151506.    -4,  /* (75) cmd ::= DROP TABLE ifexists fullname */

  151507.    -2,  /* (76) ifexists ::= IF EXISTS */

  151508.     0,  /* (77) ifexists ::= */

  151509.    -9,  /* (78) cmd ::= createkw temp VIEW ifnotexists nm dbnm eidlist_opt AS select */

  151510.    -4,  /* (79) cmd ::= DROP VIEW ifexists fullname */

  151511.    -1,  /* (80) cmd ::= select */

  151512.    -3,  /* (81) select ::= WITH wqlist selectnowith */

  151513.    -4,  /* (82) select ::= WITH RECURSIVE wqlist selectnowith */

  151514.    -1,  /* (83) select ::= selectnowith */

  151515.    -3,  /* (84) selectnowith ::= selectnowith multiselect_op oneselect */

  151516.    -1,  /* (85) multiselect_op ::= UNION */

  151517.    -2,  /* (86) multiselect_op ::= UNION ALL */

  151518.    -1,  /* (87) multiselect_op ::= EXCEPT|INTERSECT */

  151519.    -9,  /* (88) oneselect ::= SELECT distinct selcollist from where_opt groupby_opt having_opt orderby_opt limit_opt */

  151520.   -10,  /* (89) oneselect ::= SELECT distinct selcollist from where_opt groupby_opt having_opt window_clause orderby_opt limit_opt */

  151521.    -4,  /* (90) values ::= VALUES LP nexprlist RP */

  151522.    -5,  /* (91) values ::= values COMMA LP nexprlist RP */

  151523.    -1,  /* (92) distinct ::= DISTINCT */

  151524.    -1,  /* (93) distinct ::= ALL */

  151525.     0,  /* (94) distinct ::= */

  151526.     0,  /* (95) sclp ::= */

  151527.    -5,  /* (96) selcollist ::= sclp scanpt expr scanpt as */

  151528.    -3,  /* (97) selcollist ::= sclp scanpt STAR */

  151529.    -5,  /* (98) selcollist ::= sclp scanpt nm DOT STAR */

  151530.    -2,  /* (99) as ::= AS nm */

  151531.     0,  /* (100) as ::= */

  151532.     0,  /* (101) from ::= */

  151533.    -2,  /* (102) from ::= FROM seltablist */

  151534.    -2,  /* (103) stl_prefix ::= seltablist joinop */

  151535.     0,  /* (104) stl_prefix ::= */

  151536.    -7,  /* (105) seltablist ::= stl_prefix nm dbnm as indexed_opt on_opt using_opt */

  151537.    -9,  /* (106) seltablist ::= stl_prefix nm dbnm LP exprlist RP as on_opt using_opt */

  151538.    -7,  /* (107) seltablist ::= stl_prefix LP select RP as on_opt using_opt */

  151539.    -7,  /* (108) seltablist ::= stl_prefix LP seltablist RP as on_opt using_opt */

  151540.     0,  /* (109) dbnm ::= */

  151541.    -2,  /* (110) dbnm ::= DOT nm */

  151542.    -1,  /* (111) fullname ::= nm */

  151543.    -3,  /* (112) fullname ::= nm DOT nm */

  151544.    -1,  /* (113) xfullname ::= nm */

  151545.    -3,  /* (114) xfullname ::= nm DOT nm */

  151546.    -5,  /* (115) xfullname ::= nm DOT nm AS nm */

  151547.    -3,  /* (116) xfullname ::= nm AS nm */

  151548.    -1,  /* (117) joinop ::= COMMA|JOIN */

  151549.    -2,  /* (118) joinop ::= JOIN_KW JOIN */

  151550.    -3,  /* (119) joinop ::= JOIN_KW nm JOIN */

  151551.    -4,  /* (120) joinop ::= JOIN_KW nm nm JOIN */

  151552.    -2,  /* (121) on_opt ::= ON expr */

  151553.     0,  /* (122) on_opt ::= */

  151554.     0,  /* (123) indexed_opt ::= */

  151555.    -3,  /* (124) indexed_opt ::= INDEXED BY nm */

  151556.    -2,  /* (125) indexed_opt ::= NOT INDEXED */

  151557.    -4,  /* (126) using_opt ::= USING LP idlist RP */

  151558.     0,  /* (127) using_opt ::= */

  151559.     0,  /* (128) orderby_opt ::= */

  151560.    -3,  /* (129) orderby_opt ::= ORDER BY sortlist */

  151561.    -4,  /* (130) sortlist ::= sortlist COMMA expr sortorder */

  151562.    -2,  /* (131) sortlist ::= expr sortorder */

  151563.    -1,  /* (132) sortorder ::= ASC */

  151564.    -1,  /* (133) sortorder ::= DESC */

  151565.     0,  /* (134) sortorder ::= */

  151566.     0,  /* (135) groupby_opt ::= */

  151567.    -3,  /* (136) groupby_opt ::= GROUP BY nexprlist */

  151568.     0,  /* (137) having_opt ::= */

  151569.    -2,  /* (138) having_opt ::= HAVING expr */

  151570.     0,  /* (139) limit_opt ::= */

  151571.    -2,  /* (140) limit_opt ::= LIMIT expr */

  151572.    -4,  /* (141) limit_opt ::= LIMIT expr OFFSET expr */

  151573.    -4,  /* (142) limit_opt ::= LIMIT expr COMMA expr */

  151574.    -6,  /* (143) cmd ::= with DELETE FROM xfullname indexed_opt where_opt */

  151575.     0,  /* (144) where_opt ::= */

  151576.    -2,  /* (145) where_opt ::= WHERE expr */

  151577.    -8,  /* (146) cmd ::= with UPDATE orconf xfullname indexed_opt SET setlist where_opt */

  151578.    -5,  /* (147) setlist ::= setlist COMMA nm EQ expr */

  151579.    -7,  /* (148) setlist ::= setlist COMMA LP idlist RP EQ expr */

  151580.    -3,  /* (149) setlist ::= nm EQ expr */

  151581.    -5,  /* (150) setlist ::= LP idlist RP EQ expr */

  151582.    -7,  /* (151) cmd ::= with insert_cmd INTO xfullname idlist_opt select upsert */

  151583.    -7,  /* (152) cmd ::= with insert_cmd INTO xfullname idlist_opt DEFAULT VALUES */

  151584.     0,  /* (153) upsert ::= */

  151585.   -11,  /* (154) upsert ::= ON CONFLICT LP sortlist RP where_opt DO UPDATE SET setlist where_opt */

  151586.    -8,  /* (155) upsert ::= ON CONFLICT LP sortlist RP where_opt DO NOTHING */

  151587.    -4,  /* (156) upsert ::= ON CONFLICT DO NOTHING */

  151588.    -2,  /* (157) insert_cmd ::= INSERT orconf */

  151589.    -1,  /* (158) insert_cmd ::= REPLACE */

  151590.     0,  /* (159) idlist_opt ::= */

  151591.    -3,  /* (160) idlist_opt ::= LP idlist RP */

  151592.    -3,  /* (161) idlist ::= idlist COMMA nm */

  151593.    -1,  /* (162) idlist ::= nm */

  151594.    -3,  /* (163) expr ::= LP expr RP */

  151595.    -1,  /* (164) expr ::= ID|INDEXED */

  151596.    -1,  /* (165) expr ::= JOIN_KW */

  151597.    -3,  /* (166) expr ::= nm DOT nm */

  151598.    -5,  /* (167) expr ::= nm DOT nm DOT nm */

  151599.    -1,  /* (168) term ::= NULL|FLOAT|BLOB */

  151600.    -1,  /* (169) term ::= STRING */

  151601.    -1,  /* (170) term ::= INTEGER */

  151602.    -1,  /* (171) expr ::= VARIABLE */

  151603.    -3,  /* (172) expr ::= expr COLLATE ID|STRING */

  151604.    -6,  /* (173) expr ::= CAST LP expr AS typetoken RP */

  151605.    -5,  /* (174) expr ::= ID|INDEXED LP distinct exprlist RP */

  151606.    -4,  /* (175) expr ::= ID|INDEXED LP STAR RP */

  151607.    -6,  /* (176) expr ::= ID|INDEXED LP distinct exprlist RP over_clause */

  151608.    -5,  /* (177) expr ::= ID|INDEXED LP STAR RP over_clause */

  151609.    -1,  /* (178) term ::= CTIME_KW */

  151610.    -5,  /* (179) expr ::= LP nexprlist COMMA expr RP */

  151611.    -3,  /* (180) expr ::= expr AND expr */

  151612.    -3,  /* (181) expr ::= expr OR expr */

  151613.    -3,  /* (182) expr ::= expr LT|GT|GE|LE expr */

  151614.    -3,  /* (183) expr ::= expr EQ|NE expr */

  151615.    -3,  /* (184) expr ::= expr BITAND|BITOR|LSHIFT|RSHIFT expr */

  151616.    -3,  /* (185) expr ::= expr PLUS|MINUS expr */

  151617.    -3,  /* (186) expr ::= expr STAR|SLASH|REM expr */

  151618.    -3,  /* (187) expr ::= expr CONCAT expr */

  151619.    -2,  /* (188) likeop ::= NOT LIKE_KW|MATCH */

  151620.    -3,  /* (189) expr ::= expr likeop expr */

  151621.    -5,  /* (190) expr ::= expr likeop expr ESCAPE expr */

  151622.    -2,  /* (191) expr ::= expr ISNULL|NOTNULL */

  151623.    -3,  /* (192) expr ::= expr NOT NULL */

  151624.    -3,  /* (193) expr ::= expr IS expr */

  151625.    -4,  /* (194) expr ::= expr IS NOT expr */

  151626.    -2,  /* (195) expr ::= NOT expr */

  151627.    -2,  /* (196) expr ::= BITNOT expr */

  151628.    -2,  /* (197) expr ::= PLUS|MINUS expr */

  151629.    -1,  /* (198) between_op ::= BETWEEN */

  151630.    -2,  /* (199) between_op ::= NOT BETWEEN */

  151631.    -5,  /* (200) expr ::= expr between_op expr AND expr */

  151632.    -1,  /* (201) in_op ::= IN */

  151633.    -2,  /* (202) in_op ::= NOT IN */

  151634.    -5,  /* (203) expr ::= expr in_op LP exprlist RP */

  151635.    -3,  /* (204) expr ::= LP select RP */

  151636.    -5,  /* (205) expr ::= expr in_op LP select RP */

  151637.    -5,  /* (206) expr ::= expr in_op nm dbnm paren_exprlist */

  151638.    -4,  /* (207) expr ::= EXISTS LP select RP */

  151639.    -5,  /* (208) expr ::= CASE case_operand case_exprlist case_else END */

  151640.    -5,  /* (209) case_exprlist ::= case_exprlist WHEN expr THEN expr */

  151641.    -4,  /* (210) case_exprlist ::= WHEN expr THEN expr */

  151642.    -2,  /* (211) case_else ::= ELSE expr */

  151643.     0,  /* (212) case_else ::= */

  151644.    -1,  /* (213) case_operand ::= expr */

  151645.     0,  /* (214) case_operand ::= */

  151646.     0,  /* (215) exprlist ::= */

  151647.    -3,  /* (216) nexprlist ::= nexprlist COMMA expr */

  151648.    -1,  /* (217) nexprlist ::= expr */

  151649.     0,  /* (218) paren_exprlist ::= */

  151650.    -3,  /* (219) paren_exprlist ::= LP exprlist RP */

  151651.   -12,  /* (220) cmd ::= createkw uniqueflag INDEX ifnotexists nm dbnm ON nm LP sortlist RP where_opt */

  151652.    -1,  /* (221) uniqueflag ::= UNIQUE */

  151653.     0,  /* (222) uniqueflag ::= */

  151654.     0,  /* (223) eidlist_opt ::= */

  151655.    -3,  /* (224) eidlist_opt ::= LP eidlist RP */

  151656.    -5,  /* (225) eidlist ::= eidlist COMMA nm collate sortorder */

  151657.    -3,  /* (226) eidlist ::= nm collate sortorder */

  151658.     0,  /* (227) collate ::= */

  151659.    -2,  /* (228) collate ::= COLLATE ID|STRING */

  151660.    -4,  /* (229) cmd ::= DROP INDEX ifexists fullname */

  151661.    -2,  /* (230) cmd ::= VACUUM vinto */

  151662.    -3,  /* (231) cmd ::= VACUUM nm vinto */

  151663.    -2,  /* (232) vinto ::= INTO expr */

  151664.     0,  /* (233) vinto ::= */

  151665.    -3,  /* (234) cmd ::= PRAGMA nm dbnm */

  151666.    -5,  /* (235) cmd ::= PRAGMA nm dbnm EQ nmnum */

  151667.    -6,  /* (236) cmd ::= PRAGMA nm dbnm LP nmnum RP */

  151668.    -5,  /* (237) cmd ::= PRAGMA nm dbnm EQ minus_num */

  151669.    -6,  /* (238) cmd ::= PRAGMA nm dbnm LP minus_num RP */

  151670.    -2,  /* (239) plus_num ::= PLUS INTEGER|FLOAT */

  151671.    -2,  /* (240) minus_num ::= MINUS INTEGER|FLOAT */

  151672.    -5,  /* (241) cmd ::= createkw trigger_decl BEGIN trigger_cmd_list END */

  151673.   -11,  /* (242) trigger_decl ::= temp TRIGGER ifnotexists nm dbnm trigger_time trigger_event ON fullname foreach_clause when_clause */

  151674.    -1,  /* (243) trigger_time ::= BEFORE|AFTER */

  151675.    -2,  /* (244) trigger_time ::= INSTEAD OF */

  151676.     0,  /* (245) trigger_time ::= */

  151677.    -1,  /* (246) trigger_event ::= DELETE|INSERT */

  151678.    -1,  /* (247) trigger_event ::= UPDATE */

  151679.    -3,  /* (248) trigger_event ::= UPDATE OF idlist */

  151680.     0,  /* (249) when_clause ::= */

  151681.    -2,  /* (250) when_clause ::= WHEN expr */

  151682.    -3,  /* (251) trigger_cmd_list ::= trigger_cmd_list trigger_cmd SEMI */

  151683.    -2,  /* (252) trigger_cmd_list ::= trigger_cmd SEMI */

  151684.    -3,  /* (253) trnm ::= nm DOT nm */

  151685.    -3,  /* (254) tridxby ::= INDEXED BY nm */

  151686.    -2,  /* (255) tridxby ::= NOT INDEXED */

  151687.    -8,  /* (256) trigger_cmd ::= UPDATE orconf trnm tridxby SET setlist where_opt scanpt */

  151688.    -8,  /* (257) trigger_cmd ::= scanpt insert_cmd INTO trnm idlist_opt select upsert scanpt */

  151689.    -6,  /* (258) trigger_cmd ::= DELETE FROM trnm tridxby where_opt scanpt */

  151690.    -3,  /* (259) trigger_cmd ::= scanpt select scanpt */

  151691.    -4,  /* (260) expr ::= RAISE LP IGNORE RP */

  151692.    -6,  /* (261) expr ::= RAISE LP raisetype COMMA nm RP */

  151693.    -1,  /* (262) raisetype ::= ROLLBACK */

  151694.    -1,  /* (263) raisetype ::= ABORT */

  151695.    -1,  /* (264) raisetype ::= FAIL */

  151696.    -4,  /* (265) cmd ::= DROP TRIGGER ifexists fullname */

  151697.    -6,  /* (266) cmd ::= ATTACH database_kw_opt expr AS expr key_opt */

  151698.    -3,  /* (267) cmd ::= DETACH database_kw_opt expr */

  151699.     0,  /* (268) key_opt ::= */

  151700.    -2,  /* (269) key_opt ::= KEY expr */

  151701.    -1,  /* (270) cmd ::= REINDEX */

  151702.    -3,  /* (271) cmd ::= REINDEX nm dbnm */

  151703.    -1,  /* (272) cmd ::= ANALYZE */

  151704.    -3,  /* (273) cmd ::= ANALYZE nm dbnm */

  151705.    -6,  /* (274) cmd ::= ALTER TABLE fullname RENAME TO nm */

  151706.    -7,  /* (275) cmd ::= ALTER TABLE add_column_fullname ADD kwcolumn_opt columnname carglist */

  151707.    -1,  /* (276) add_column_fullname ::= fullname */

  151708.    -8,  /* (277) cmd ::= ALTER TABLE fullname RENAME kwcolumn_opt nm TO nm */

  151709.    -1,  /* (278) cmd ::= create_vtab */

  151710.    -4,  /* (279) cmd ::= create_vtab LP vtabarglist RP */

  151711.    -8,  /* (280) create_vtab ::= createkw VIRTUAL TABLE ifnotexists nm dbnm USING nm */

  151712.     0,  /* (281) vtabarg ::= */

  151713.    -1,  /* (282) vtabargtoken ::= ANY */

  151714.    -3,  /* (283) vtabargtoken ::= lp anylist RP */

  151715.    -1,  /* (284) lp ::= LP */

  151716.    -2,  /* (285) with ::= WITH wqlist */

  151717.    -3,  /* (286) with ::= WITH RECURSIVE wqlist */

  151718.    -6,  /* (287) wqlist ::= nm eidlist_opt AS LP select RP */

  151719.    -8,  /* (288) wqlist ::= wqlist COMMA nm eidlist_opt AS LP select RP */

  151720.    -1,  /* (289) windowdefn_list ::= windowdefn */

  151721.    -3,  /* (290) windowdefn_list ::= windowdefn_list COMMA windowdefn */

  151722.    -5,  /* (291) windowdefn ::= nm AS LP window RP */

  151723.    -5,  /* (292) window ::= PARTITION BY nexprlist orderby_opt frame_opt */

  151724.    -6,  /* (293) window ::= nm PARTITION BY nexprlist orderby_opt frame_opt */

  151725.    -4,  /* (294) window ::= ORDER BY sortlist frame_opt */

  151726.    -5,  /* (295) window ::= nm ORDER BY sortlist frame_opt */

  151727.    -1,  /* (296) window ::= frame_opt */

  151728.    -2,  /* (297) window ::= nm frame_opt */

  151729.     0,  /* (298) frame_opt ::= */

  151730.    -3,  /* (299) frame_opt ::= range_or_rows frame_bound_s frame_exclude_opt */

  151731.    -6,  /* (300) frame_opt ::= range_or_rows BETWEEN frame_bound_s AND frame_bound_e frame_exclude_opt */

  151732.    -1,  /* (301) range_or_rows ::= RANGE|ROWS|GROUPS */

  151733.    -1,  /* (302) frame_bound_s ::= frame_bound */

  151734.    -2,  /* (303) frame_bound_s ::= UNBOUNDED PRECEDING */

  151735.    -1,  /* (304) frame_bound_e ::= frame_bound */

  151736.    -2,  /* (305) frame_bound_e ::= UNBOUNDED FOLLOWING */

  151737.    -2,  /* (306) frame_bound ::= expr PRECEDING|FOLLOWING */

  151738.    -2,  /* (307) frame_bound ::= CURRENT ROW */

  151739.     0,  /* (308) frame_exclude_opt ::= */

  151740.    -2,  /* (309) frame_exclude_opt ::= EXCLUDE frame_exclude */

  151741.    -2,  /* (310) frame_exclude ::= NO OTHERS */

  151742.    -2,  /* (311) frame_exclude ::= CURRENT ROW */

  151743.    -1,  /* (312) frame_exclude ::= GROUP|TIES */

  151744.    -2,  /* (313) window_clause ::= WINDOW windowdefn_list */

  151745.    -5,  /* (314) over_clause ::= filter_opt OVER LP window RP */

  151746.    -3,  /* (315) over_clause ::= filter_opt OVER nm */

  151747.     0,  /* (316) filter_opt ::= */

  151748.    -5,  /* (317) filter_opt ::= FILTER LP WHERE expr RP */

  151749.    -1,  /* (318) input ::= cmdlist */

  151750.    -2,  /* (319) cmdlist ::= cmdlist ecmd */

  151751.    -1,  /* (320) cmdlist ::= ecmd */

  151752.    -1,  /* (321) ecmd ::= SEMI */

  151753.    -2,  /* (322) ecmd ::= cmdx SEMI */

  151754.    -2,  /* (323) ecmd ::= explain cmdx */

  151755.     0,  /* (324) trans_opt ::= */

  151756.    -1,  /* (325) trans_opt ::= TRANSACTION */

  151757.    -2,  /* (326) trans_opt ::= TRANSACTION nm */

  151758.    -1,  /* (327) savepoint_opt ::= SAVEPOINT */

  151759.     0,  /* (328) savepoint_opt ::= */

  151760.    -2,  /* (329) cmd ::= create_table create_table_args */

  151761.    -4,  /* (330) columnlist ::= columnlist COMMA columnname carglist */

  151762.    -2,  /* (331) columnlist ::= columnname carglist */

  151763.    -1,  /* (332) nm ::= ID|INDEXED */

  151764.    -1,  /* (333) nm ::= STRING */

  151765.    -1,  /* (334) nm ::= JOIN_KW */

  151766.    -1,  /* (335) typetoken ::= typename */

  151767.    -1,  /* (336) typename ::= ID|STRING */

  151768.    -1,  /* (337) signed ::= plus_num */

  151769.    -1,  /* (338) signed ::= minus_num */

  151770.    -2,  /* (339) carglist ::= carglist ccons */

  151771.     0,  /* (340) carglist ::= */

  151772.    -2,  /* (341) ccons ::= NULL onconf */

  151773.    -2,  /* (342) conslist_opt ::= COMMA conslist */

  151774.    -3,  /* (343) conslist ::= conslist tconscomma tcons */

  151775.    -1,  /* (344) conslist ::= tcons */

  151776.     0,  /* (345) tconscomma ::= */

  151777.    -1,  /* (346) defer_subclause_opt ::= defer_subclause */

  151778.    -1,  /* (347) resolvetype ::= raisetype */

  151779.    -1,  /* (348) selectnowith ::= oneselect */

  151780.    -1,  /* (349) oneselect ::= values */

  151781.    -2,  /* (350) sclp ::= selcollist COMMA */

  151782.    -1,  /* (351) as ::= ID|STRING */

  151783.    -1,  /* (352) expr ::= term */

  151784.    -1,  /* (353) likeop ::= LIKE_KW|MATCH */

  151785.    -1,  /* (354) exprlist ::= nexprlist */

  151786.    -1,  /* (355) nmnum ::= plus_num */

  151787.    -1,  /* (356) nmnum ::= nm */

  151788.    -1,  /* (357) nmnum ::= ON */

  151789.    -1,  /* (358) nmnum ::= DELETE */

  151790.    -1,  /* (359) nmnum ::= DEFAULT */

  151791.    -1,  /* (360) plus_num ::= INTEGER|FLOAT */

  151792.     0,  /* (361) foreach_clause ::= */

  151793.    -3,  /* (362) foreach_clause ::= FOR EACH ROW */

  151794.    -1,  /* (363) trnm ::= nm */

  151795.     0,  /* (364) tridxby ::= */

  151796.    -1,  /* (365) database_kw_opt ::= DATABASE */

  151797.     0,  /* (366) database_kw_opt ::= */

  151798.     0,  /* (367) kwcolumn_opt ::= */

  151799.    -1,  /* (368) kwcolumn_opt ::= COLUMNKW */

  151800.    -1,  /* (369) vtabarglist ::= vtabarg */

  151801.    -3,  /* (370) vtabarglist ::= vtabarglist COMMA vtabarg */

  151802.    -2,  /* (371) vtabarg ::= vtabarg vtabargtoken */

  151803.     0,  /* (372) anylist ::= */

  151804.    -4,  /* (373) anylist ::= anylist LP anylist RP */

  151805.    -2,  /* (374) anylist ::= anylist ANY */

  151806.     0,  /* (375) with ::= */

  151807. };

  151808. 

  151809. static void yy_accept(yyParser*);  /* Forward Declaration */

  151810. 

  151811. /*

  151812. ** Perform a reduce action and the shift that must immediately

  151813. ** follow the reduce.

  151814. **

  151815. ** The yyLookahead and yyLookaheadToken parameters provide reduce actions

  151816. ** access to the lookahead token (if any).  The yyLookahead will be YYNOCODE

  151817. ** if the lookahead token has already been consumed.  As this procedure is

  151818. ** only called from one place, optimizing compilers will in-line it, which

  151819. ** means that the extra parameters have no performance impact.

  151820. */

  151821. static YYACTIONTYPE yy_reduce(

  151822.   yyParser *yypParser,         /* The parser */

  151823.   unsigned int yyruleno,       /* Number of the rule by which to reduce */

  151824.   int yyLookahead,             /* Lookahead token, or YYNOCODE if none */

  151825.   sqlite3ParserTOKENTYPE yyLookaheadToken  /* Value of the lookahead token */

  151826.   sqlite3ParserCTX_PDECL                   /* %extra_context */

  151827. ){

  151828.   int yygoto;                     /* The next state */

  151829.   YYACTIONTYPE yyact;             /* The next action */

  151830.   yyStackEntry *yymsp;            /* The top of the parser's stack */

  151831.   int yysize;                     /* Amount to pop the stack */

  151832.   sqlite3ParserARG_FETCH

  151833.   (void)yyLookahead;

  151834.   (void)yyLookaheadToken;

  151835.   yymsp = yypParser->yytos;

  151836. #ifndef NDEBUG

  151837.   if( yyTraceFILE && yyruleno<(int)(sizeof(yyRuleName)/sizeof(yyRuleName[0])) ){

  151838.     yysize = yyRuleInfoNRhs[yyruleno];

  151839.     if( yysize ){

  151840.       fprintf(yyTraceFILE, "%sReduce %d [%s], go to state %d.\n",

  151841.         yyTracePrompt,

  151842.         yyruleno, yyRuleName[yyruleno], yymsp[yysize].stateno);

  151843.     }else{

  151844.       fprintf(yyTraceFILE, "%sReduce %d [%s].\n",

  151845.         yyTracePrompt, yyruleno, yyRuleName[yyruleno]);

  151846.     }

  151847.   }

  151848. #endif /* NDEBUG */

  151849. 

  151850.   /* Check that the stack is large enough to grow by a single entry

  151851.   ** if the RHS of the rule is empty.  This ensures that there is room

  151852.   ** enough on the stack to push the LHS value */

  151853.   if( yyRuleInfoNRhs[yyruleno]==0 ){

  151854. #ifdef YYTRACKMAXSTACKDEPTH

  151855.     if( (int)(yypParser->yytos - yypParser->yystack)>yypParser->yyhwm ){

  151856.       yypParser->yyhwm++;

  151857.       assert( yypParser->yyhwm == (int)(yypParser->yytos - yypParser->yystack));

  151858.     }

  151859. #endif

  151860. #if YYSTACKDEPTH>0 

  151861.     if( yypParser->yytos>=yypParser->yystackEnd ){

  151862.       yyStackOverflow(yypParser);

  151863.       /* The call to yyStackOverflow() above pops the stack until it is

  151864.       ** empty, causing the main parser loop to exit.  So the return value

  151865.       ** is never used and does not matter. */

  151866.       return 0;

  151867.     }

  151868. #else

  151869.     if( yypParser->yytos>=&yypParser->yystack[yypParser->yystksz-1] ){

  151870.       if( yyGrowStack(yypParser) ){

  151871.         yyStackOverflow(yypParser);

  151872.         /* The call to yyStackOverflow() above pops the stack until it is

  151873.         ** empty, causing the main parser loop to exit.  So the return value

  151874.         ** is never used and does not matter. */

  151875.         return 0;

  151876.       }

  151877.       yymsp = yypParser->yytos;

  151878.     }

  151879. #endif

  151880.   }

  151881. 

  151882.   switch( yyruleno ){

  151883.   /* Beginning here are the reduction cases.  A typical example

  151884.   ** follows:

  151885.   **   case 0:

  151886.   **  #line <lineno> <grammarfile>

  151887.   **     { ... }           // User supplied code

  151888.   **  #line <lineno> <thisfile>

  151889.   **     break;

  151890.   */

  151891. /********** Begin reduce actions **********************************************/

  151892.         YYMINORTYPE yylhsminor;

  151893.       case 0: /* explain ::= EXPLAIN */

  151894. { pParse->explain = 1; }

  151895.         break;

  151896.       case 1: /* explain ::= EXPLAIN QUERY PLAN */

  151897. { pParse->explain = 2; }

  151898.         break;

  151899.       case 2: /* cmdx ::= cmd */

  151900. { sqlite3FinishCoding(pParse); }

  151901.         break;

  151902.       case 3: /* cmd ::= BEGIN transtype trans_opt */

  151903. {sqlite3BeginTransaction(pParse, yymsp[-1].minor.yy100);}

  151904.         break;

  151905.       case 4: /* transtype ::= */

  151906. {yymsp[1].minor.yy100 = TK_DEFERRED;}

  151907.         break;

  151908.       case 5: /* transtype ::= DEFERRED */

  151909.       case 6: /* transtype ::= IMMEDIATE */ yytestcase(yyruleno==6);

  151910.       case 7: /* transtype ::= EXCLUSIVE */ yytestcase(yyruleno==7);

  151911.       case 301: /* range_or_rows ::= RANGE|ROWS|GROUPS */ yytestcase(yyruleno==301);

  151912. {yymsp[0].minor.yy100 = yymsp[0].major; /*A-overwrites-X*/}

  151913.         break;

  151914.       case 8: /* cmd ::= COMMIT|END trans_opt */

  151915.       case 9: /* cmd ::= ROLLBACK trans_opt */ yytestcase(yyruleno==9);

  151916. {sqlite3EndTransaction(pParse,yymsp[-1].major);}

  151917.         break;

  151918.       case 10: /* cmd ::= SAVEPOINT nm */

  151919. {

  151920.   sqlite3Savepoint(pParse, SAVEPOINT_BEGIN, &yymsp[0].minor.yy0);

  151921. }

  151922.         break;

  151923.       case 11: /* cmd ::= RELEASE savepoint_opt nm */

  151924. {

  151925.   sqlite3Savepoint(pParse, SAVEPOINT_RELEASE, &yymsp[0].minor.yy0);

  151926. }

  151927.         break;

  151928.       case 12: /* cmd ::= ROLLBACK trans_opt TO savepoint_opt nm */

  151929. {

  151930.   sqlite3Savepoint(pParse, SAVEPOINT_ROLLBACK, &yymsp[0].minor.yy0);

  151931. }

  151932.         break;

  151933.       case 13: /* create_table ::= createkw temp TABLE ifnotexists nm dbnm */

  151934. {

  151935.    sqlite3StartTable(pParse,&yymsp[-1].minor.yy0,&yymsp[0].minor.yy0,yymsp[-4].minor.yy100,0,0,yymsp[-2].minor.yy100);

  151936. }

  151937.         break;

  151938.       case 14: /* createkw ::= CREATE */

  151939. {disableLookaside(pParse);}

  151940.         break;

  151941.       case 15: /* ifnotexists ::= */

  151942.       case 18: /* temp ::= */ yytestcase(yyruleno==18);

  151943.       case 21: /* table_options ::= */ yytestcase(yyruleno==21);

  151944.       case 43: /* autoinc ::= */ yytestcase(yyruleno==43);

  151945.       case 58: /* init_deferred_pred_opt ::= */ yytestcase(yyruleno==58);

  151946.       case 68: /* defer_subclause_opt ::= */ yytestcase(yyruleno==68);

  151947.       case 77: /* ifexists ::= */ yytestcase(yyruleno==77);

  151948.       case 94: /* distinct ::= */ yytestcase(yyruleno==94);

  151949.       case 227: /* collate ::= */ yytestcase(yyruleno==227);

  151950. {yymsp[1].minor.yy100 = 0;}

  151951.         break;

  151952.       case 16: /* ifnotexists ::= IF NOT EXISTS */

  151953. {yymsp[-2].minor.yy100 = 1;}

  151954.         break;

  151955.       case 17: /* temp ::= TEMP */

  151956.       case 44: /* autoinc ::= AUTOINCR */ yytestcase(yyruleno==44);

  151957. {yymsp[0].minor.yy100 = 1;}

  151958.         break;

  151959.       case 19: /* create_table_args ::= LP columnlist conslist_opt RP table_options */

  151960. {

  151961.   sqlite3EndTable(pParse,&yymsp[-2].minor.yy0,&yymsp[-1].minor.yy0,yymsp[0].minor.yy100,0);

  151962. }

  151963.         break;

  151964.       case 20: /* create_table_args ::= AS select */

  151965. {

  151966.   sqlite3EndTable(pParse,0,0,0,yymsp[0].minor.yy391);

  151967.   sqlite3SelectDelete(pParse->db, yymsp[0].minor.yy391);

  151968. }

  151969.         break;

  151970.       case 22: /* table_options ::= WITHOUT nm */

  151971. {

  151972.   if( yymsp[0].minor.yy0.n==5 && sqlite3_strnicmp(yymsp[0].minor.yy0.z,"rowid",5)==0 ){

  151973.     yymsp[-1].minor.yy100 = TF_WithoutRowid | TF_NoVisibleRowid;

  151974.   }else{

  151975.     yymsp[-1].minor.yy100 = 0;

  151976.     sqlite3ErrorMsg(pParse, "unknown table option: %.*s", yymsp[0].minor.yy0.n, yymsp[0].minor.yy0.z);

  151977.   }

  151978. }

  151979.         break;

  151980.       case 23: /* columnname ::= nm typetoken */

  151981. {sqlite3AddColumn(pParse,&yymsp[-1].minor.yy0,&yymsp[0].minor.yy0);}

  151982.         break;

  151983.       case 24: /* typetoken ::= */

  151984.       case 61: /* conslist_opt ::= */ yytestcase(yyruleno==61);

  151985.       case 100: /* as ::= */ yytestcase(yyruleno==100);

  151986. {yymsp[1].minor.yy0.n = 0; yymsp[1].minor.yy0.z = 0;}

  151987.         break;

  151988.       case 25: /* typetoken ::= typename LP signed RP */

  151989. {

  151990.   yymsp[-3].minor.yy0.n = (int)(&yymsp[0].minor.yy0.z[yymsp[0].minor.yy0.n] - yymsp[-3].minor.yy0.z);

  151991. }

  151992.         break;

  151993.       case 26: /* typetoken ::= typename LP signed COMMA signed RP */

  151994. {

  151995.   yymsp[-5].minor.yy0.n = (int)(&yymsp[0].minor.yy0.z[yymsp[0].minor.yy0.n] - yymsp[-5].minor.yy0.z);

  151996. }

  151997.         break;

  151998.       case 27: /* typename ::= typename ID|STRING */

  151999. {yymsp[-1].minor.yy0.n=yymsp[0].minor.yy0.n+(int)(yymsp[0].minor.yy0.z-yymsp[-1].minor.yy0.z);}

  152000.         break;

  152001.       case 28: /* scanpt ::= */

  152002. {

  152003.   assert( yyLookahead!=YYNOCODE );

  152004.   yymsp[1].minor.yy528 = yyLookaheadToken.z;

  152005. }

  152006.         break;

  152007.       case 29: /* scantok ::= */

  152008. {

  152009.   assert( yyLookahead!=YYNOCODE );

  152010.   yymsp[1].minor.yy0 = yyLookaheadToken;

  152011. }

  152012.         break;

  152013.       case 30: /* ccons ::= CONSTRAINT nm */

  152014.       case 63: /* tcons ::= CONSTRAINT nm */ yytestcase(yyruleno==63);

  152015. {pParse->constraintName = yymsp[0].minor.yy0;}

  152016.         break;

  152017.       case 31: /* ccons ::= DEFAULT scantok term */

  152018. {sqlite3AddDefaultValue(pParse,yymsp[0].minor.yy102,yymsp[-1].minor.yy0.z,&yymsp[-1].minor.yy0.z[yymsp[-1].minor.yy0.n]);}

  152019.         break;

  152020.       case 32: /* ccons ::= DEFAULT LP expr RP */

  152021. {sqlite3AddDefaultValue(pParse,yymsp[-1].minor.yy102,yymsp[-2].minor.yy0.z+1,yymsp[0].minor.yy0.z);}

  152022.         break;

  152023.       case 33: /* ccons ::= DEFAULT PLUS scantok term */

  152024. {sqlite3AddDefaultValue(pParse,yymsp[0].minor.yy102,yymsp[-2].minor.yy0.z,&yymsp[-1].minor.yy0.z[yymsp[-1].minor.yy0.n]);}

  152025.         break;

  152026.       case 34: /* ccons ::= DEFAULT MINUS scantok term */

  152027. {

  152028.   Expr *p = sqlite3PExpr(pParse, TK_UMINUS, yymsp[0].minor.yy102, 0);

  152029.   sqlite3AddDefaultValue(pParse,p,yymsp[-2].minor.yy0.z,&yymsp[-1].minor.yy0.z[yymsp[-1].minor.yy0.n]);

  152030. }

  152031.         break;

  152032.       case 35: /* ccons ::= DEFAULT scantok ID|INDEXED */

  152033. {

  152034.   Expr *p = tokenExpr(pParse, TK_STRING, yymsp[0].minor.yy0);

  152035.   if( p ){

  152036.     sqlite3ExprIdToTrueFalse(p);

  152037.     testcase( p->op==TK_TRUEFALSE && sqlite3ExprTruthValue(p) );

  152038.   }

  152039.     sqlite3AddDefaultValue(pParse,p,yymsp[0].minor.yy0.z,yymsp[0].minor.yy0.z+yymsp[0].minor.yy0.n);

  152040. }

  152041.         break;

  152042.       case 36: /* ccons ::= NOT NULL onconf */

  152043. {sqlite3AddNotNull(pParse, yymsp[0].minor.yy100);}

  152044.         break;

  152045.       case 37: /* ccons ::= PRIMARY KEY sortorder onconf autoinc */

  152046. {sqlite3AddPrimaryKey(pParse,0,yymsp[-1].minor.yy100,yymsp[0].minor.yy100,yymsp[-2].minor.yy100);}

  152047.         break;

  152048.       case 38: /* ccons ::= UNIQUE onconf */

  152049. {sqlite3CreateIndex(pParse,0,0,0,0,yymsp[0].minor.yy100,0,0,0,0,

  152050.                                    SQLITE_IDXTYPE_UNIQUE);}

  152051.         break;

  152052.       case 39: /* ccons ::= CHECK LP expr RP */

  152053. {sqlite3AddCheckConstraint(pParse,yymsp[-1].minor.yy102);}

  152054.         break;

  152055.       case 40: /* ccons ::= REFERENCES nm eidlist_opt refargs */

  152056. {sqlite3CreateForeignKey(pParse,0,&yymsp[-2].minor.yy0,yymsp[-1].minor.yy94,yymsp[0].minor.yy100);}

  152057.         break;

  152058.       case 41: /* ccons ::= defer_subclause */

  152059. {sqlite3DeferForeignKey(pParse,yymsp[0].minor.yy100);}

  152060.         break;

  152061.       case 42: /* ccons ::= COLLATE ID|STRING */

  152062. {sqlite3AddCollateType(pParse, &yymsp[0].minor.yy0);}

  152063.         break;

  152064.       case 45: /* refargs ::= */

  152065. { yymsp[1].minor.yy100 = OE_None*0x0101; /* EV: R-19803-45884 */}

  152066.         break;

  152067.       case 46: /* refargs ::= refargs refarg */

  152068. { yymsp[-1].minor.yy100 = (yymsp[-1].minor.yy100 & ~yymsp[0].minor.yy199.mask) | yymsp[0].minor.yy199.value; }

  152069.         break;

  152070.       case 47: /* refarg ::= MATCH nm */

  152071. { yymsp[-1].minor.yy199.value = 0;     yymsp[-1].minor.yy199.mask = 0x000000; }

  152072.         break;

  152073.       case 48: /* refarg ::= ON INSERT refact */

  152074. { yymsp[-2].minor.yy199.value = 0;     yymsp[-2].minor.yy199.mask = 0x000000; }

  152075.         break;

  152076.       case 49: /* refarg ::= ON DELETE refact */

  152077. { yymsp[-2].minor.yy199.value = yymsp[0].minor.yy100;     yymsp[-2].minor.yy199.mask = 0x0000ff; }

  152078.         break;

  152079.       case 50: /* refarg ::= ON UPDATE refact */

  152080. { yymsp[-2].minor.yy199.value = yymsp[0].minor.yy100<<8;  yymsp[-2].minor.yy199.mask = 0x00ff00; }

  152081.         break;

  152082.       case 51: /* refact ::= SET NULL */

  152083. { yymsp[-1].minor.yy100 = OE_SetNull;  /* EV: R-33326-45252 */}

  152084.         break;

  152085.       case 52: /* refact ::= SET DEFAULT */

  152086. { yymsp[-1].minor.yy100 = OE_SetDflt;  /* EV: R-33326-45252 */}

  152087.         break;

  152088.       case 53: /* refact ::= CASCADE */

  152089. { yymsp[0].minor.yy100 = OE_Cascade;  /* EV: R-33326-45252 */}

  152090.         break;

  152091.       case 54: /* refact ::= RESTRICT */

  152092. { yymsp[0].minor.yy100 = OE_Restrict; /* EV: R-33326-45252 */}

  152093.         break;

  152094.       case 55: /* refact ::= NO ACTION */

  152095. { yymsp[-1].minor.yy100 = OE_None;     /* EV: R-33326-45252 */}

  152096.         break;

  152097.       case 56: /* defer_subclause ::= NOT DEFERRABLE init_deferred_pred_opt */

  152098. {yymsp[-2].minor.yy100 = 0;}

  152099.         break;

  152100.       case 57: /* defer_subclause ::= DEFERRABLE init_deferred_pred_opt */

  152101.       case 72: /* orconf ::= OR resolvetype */ yytestcase(yyruleno==72);

  152102.       case 157: /* insert_cmd ::= INSERT orconf */ yytestcase(yyruleno==157);

  152103. {yymsp[-1].minor.yy100 = yymsp[0].minor.yy100;}

  152104.         break;

  152105.       case 59: /* init_deferred_pred_opt ::= INITIALLY DEFERRED */

  152106.       case 76: /* ifexists ::= IF EXISTS */ yytestcase(yyruleno==76);

  152107.       case 199: /* between_op ::= NOT BETWEEN */ yytestcase(yyruleno==199);

  152108.       case 202: /* in_op ::= NOT IN */ yytestcase(yyruleno==202);

  152109.       case 228: /* collate ::= COLLATE ID|STRING */ yytestcase(yyruleno==228);

  152110. {yymsp[-1].minor.yy100 = 1;}

  152111.         break;

  152112.       case 60: /* init_deferred_pred_opt ::= INITIALLY IMMEDIATE */

  152113. {yymsp[-1].minor.yy100 = 0;}

  152114.         break;

  152115.       case 62: /* tconscomma ::= COMMA */

  152116. {pParse->constraintName.n = 0;}

  152117.         break;

  152118.       case 64: /* tcons ::= PRIMARY KEY LP sortlist autoinc RP onconf */

  152119. {sqlite3AddPrimaryKey(pParse,yymsp[-3].minor.yy94,yymsp[0].minor.yy100,yymsp[-2].minor.yy100,0);}

  152120.         break;

  152121.       case 65: /* tcons ::= UNIQUE LP sortlist RP onconf */

  152122. {sqlite3CreateIndex(pParse,0,0,0,yymsp[-2].minor.yy94,yymsp[0].minor.yy100,0,0,0,0,

  152123.                                        SQLITE_IDXTYPE_UNIQUE);}

  152124.         break;

  152125.       case 66: /* tcons ::= CHECK LP expr RP onconf */

  152126. {sqlite3AddCheckConstraint(pParse,yymsp[-2].minor.yy102);}

  152127.         break;

  152128.       case 67: /* tcons ::= FOREIGN KEY LP eidlist RP REFERENCES nm eidlist_opt refargs defer_subclause_opt */

  152129. {

  152130.     sqlite3CreateForeignKey(pParse, yymsp[-6].minor.yy94, &yymsp[-3].minor.yy0, yymsp[-2].minor.yy94, yymsp[-1].minor.yy100);

  152131.     sqlite3DeferForeignKey(pParse, yymsp[0].minor.yy100);

  152132. }

  152133.         break;

  152134.       case 69: /* onconf ::= */

  152135.       case 71: /* orconf ::= */ yytestcase(yyruleno==71);

  152136. {yymsp[1].minor.yy100 = OE_Default;}

  152137.         break;

  152138.       case 70: /* onconf ::= ON CONFLICT resolvetype */

  152139. {yymsp[-2].minor.yy100 = yymsp[0].minor.yy100;}

  152140.         break;

  152141.       case 73: /* resolvetype ::= IGNORE */

  152142. {yymsp[0].minor.yy100 = OE_Ignore;}

  152143.         break;

  152144.       case 74: /* resolvetype ::= REPLACE */

  152145.       case 158: /* insert_cmd ::= REPLACE */ yytestcase(yyruleno==158);

  152146. {yymsp[0].minor.yy100 = OE_Replace;}

  152147.         break;

  152148.       case 75: /* cmd ::= DROP TABLE ifexists fullname */

  152149. {

  152150.   sqlite3DropTable(pParse, yymsp[0].minor.yy407, 0, yymsp[-1].minor.yy100);

  152151. }

  152152.         break;

  152153.       case 78: /* cmd ::= createkw temp VIEW ifnotexists nm dbnm eidlist_opt AS select */

  152154. {

  152155.   sqlite3CreateView(pParse, &yymsp[-8].minor.yy0, &yymsp[-4].minor.yy0, &yymsp[-3].minor.yy0, yymsp[-2].minor.yy94, yymsp[0].minor.yy391, yymsp[-7].minor.yy100, yymsp[-5].minor.yy100);

  152156. }

  152157.         break;

  152158.       case 79: /* cmd ::= DROP VIEW ifexists fullname */

  152159. {

  152160.   sqlite3DropTable(pParse, yymsp[0].minor.yy407, 1, yymsp[-1].minor.yy100);

  152161. }

  152162.         break;

  152163.       case 80: /* cmd ::= select */

  152164. {

  152165.   SelectDest dest = {SRT_Output, 0, 0, 0, 0, 0};

  152166.   sqlite3Select(pParse, yymsp[0].minor.yy391, &dest);

  152167.   sqlite3SelectDelete(pParse->db, yymsp[0].minor.yy391);

  152168. }

  152169.         break;

  152170.       case 81: /* select ::= WITH wqlist selectnowith */

  152171. {

  152172.   Select *p = yymsp[0].minor.yy391;

  152173.   if( p ){

  152174.     p->pWith = yymsp[-1].minor.yy243;

  152175.     parserDoubleLinkSelect(pParse, p);

  152176.   }else{

  152177.     sqlite3WithDelete(pParse->db, yymsp[-1].minor.yy243);

  152178.   }

  152179.   yymsp[-2].minor.yy391 = p;

  152180. }

  152181.         break;

  152182.       case 82: /* select ::= WITH RECURSIVE wqlist selectnowith */

  152183. {

  152184.   Select *p = yymsp[0].minor.yy391;

  152185.   if( p ){

  152186.     p->pWith = yymsp[-1].minor.yy243;

  152187.     parserDoubleLinkSelect(pParse, p);

  152188.   }else{

  152189.     sqlite3WithDelete(pParse->db, yymsp[-1].minor.yy243);

  152190.   }

  152191.   yymsp[-3].minor.yy391 = p;

  152192. }

  152193.         break;

  152194.       case 83: /* select ::= selectnowith */

  152195. {

  152196.   Select *p = yymsp[0].minor.yy391;

  152197.   if( p ){

  152198.     parserDoubleLinkSelect(pParse, p);

  152199.   }

  152200.   yymsp[0].minor.yy391 = p; /*A-overwrites-X*/

  152201. }

  152202.         break;

  152203.       case 84: /* selectnowith ::= selectnowith multiselect_op oneselect */

  152204. {

  152205.   Select *pRhs = yymsp[0].minor.yy391;

  152206.   Select *pLhs = yymsp[-2].minor.yy391;

  152207.   if( pRhs && pRhs->pPrior ){

  152208.     SrcList *pFrom;

  152209.     Token x;

  152210.     x.n = 0;

  152211.     parserDoubleLinkSelect(pParse, pRhs);

  152212.     pFrom = sqlite3SrcListAppendFromTerm(pParse,0,0,0,&x,pRhs,0,0);

  152213.     pRhs = sqlite3SelectNew(pParse,0,pFrom,0,0,0,0,0,0);

  152214.   }

  152215.   if( pRhs ){

  152216.     pRhs->op = (u8)yymsp[-1].minor.yy100;

  152217.     pRhs->pPrior = pLhs;

  152218.     if( ALWAYS(pLhs) ) pLhs->selFlags &= ~SF_MultiValue;

  152219.     pRhs->selFlags &= ~SF_MultiValue;

  152220.     if( yymsp[-1].minor.yy100!=TK_ALL ) pParse->hasCompound = 1;

  152221.   }else{

  152222.     sqlite3SelectDelete(pParse->db, pLhs);

  152223.   }

  152224.   yymsp[-2].minor.yy391 = pRhs;

  152225. }

  152226.         break;

  152227.       case 85: /* multiselect_op ::= UNION */

  152228.       case 87: /* multiselect_op ::= EXCEPT|INTERSECT */ yytestcase(yyruleno==87);

  152229. {yymsp[0].minor.yy100 = yymsp[0].major; /*A-overwrites-OP*/}

  152230.         break;

  152231.       case 86: /* multiselect_op ::= UNION ALL */

  152232. {yymsp[-1].minor.yy100 = TK_ALL;}

  152233.         break;

  152234.       case 88: /* oneselect ::= SELECT distinct selcollist from where_opt groupby_opt having_opt orderby_opt limit_opt */

  152235. {

  152236.   yymsp[-8].minor.yy391 = sqlite3SelectNew(pParse,yymsp[-6].minor.yy94,yymsp[-5].minor.yy407,yymsp[-4].minor.yy102,yymsp[-3].minor.yy94,yymsp[-2].minor.yy102,yymsp[-1].minor.yy94,yymsp[-7].minor.yy100,yymsp[0].minor.yy102);

  152237. }

  152238.         break;

  152239.       case 89: /* oneselect ::= SELECT distinct selcollist from where_opt groupby_opt having_opt window_clause orderby_opt limit_opt */

  152240. {

  152241.   yymsp[-9].minor.yy391 = sqlite3SelectNew(pParse,yymsp[-7].minor.yy94,yymsp[-6].minor.yy407,yymsp[-5].minor.yy102,yymsp[-4].minor.yy94,yymsp[-3].minor.yy102,yymsp[-1].minor.yy94,yymsp[-8].minor.yy100,yymsp[0].minor.yy102);

  152242.   if( yymsp[-9].minor.yy391 ){

  152243.     yymsp[-9].minor.yy391->pWinDefn = yymsp[-2].minor.yy379;

  152244.   }else{

  152245.     sqlite3WindowListDelete(pParse->db, yymsp[-2].minor.yy379);

  152246.   }

  152247. }

  152248.         break;

  152249.       case 90: /* values ::= VALUES LP nexprlist RP */

  152250. {

  152251.   yymsp[-3].minor.yy391 = sqlite3SelectNew(pParse,yymsp[-1].minor.yy94,0,0,0,0,0,SF_Values,0);

  152252. }

  152253.         break;

  152254.       case 91: /* values ::= values COMMA LP nexprlist RP */

  152255. {

  152256.   Select *pRight, *pLeft = yymsp[-4].minor.yy391;

  152257.   pRight = sqlite3SelectNew(pParse,yymsp[-1].minor.yy94,0,0,0,0,0,SF_Values|SF_MultiValue,0);

  152258.   if( ALWAYS(pLeft) ) pLeft->selFlags &= ~SF_MultiValue;

  152259.   if( pRight ){

  152260.     pRight->op = TK_ALL;

  152261.     pRight->pPrior = pLeft;

  152262.     yymsp[-4].minor.yy391 = pRight;

  152263.   }else{

  152264.     yymsp[-4].minor.yy391 = pLeft;

  152265.   }

  152266. }

  152267.         break;

  152268.       case 92: /* distinct ::= DISTINCT */

  152269. {yymsp[0].minor.yy100 = SF_Distinct;}

  152270.         break;

  152271.       case 93: /* distinct ::= ALL */

  152272. {yymsp[0].minor.yy100 = SF_All;}

  152273.         break;

  152274.       case 95: /* sclp ::= */

  152275.       case 128: /* orderby_opt ::= */ yytestcase(yyruleno==128);

  152276.       case 135: /* groupby_opt ::= */ yytestcase(yyruleno==135);

  152277.       case 215: /* exprlist ::= */ yytestcase(yyruleno==215);

  152278.       case 218: /* paren_exprlist ::= */ yytestcase(yyruleno==218);

  152279.       case 223: /* eidlist_opt ::= */ yytestcase(yyruleno==223);

  152280. {yymsp[1].minor.yy94 = 0;}

  152281.         break;

  152282.       case 96: /* selcollist ::= sclp scanpt expr scanpt as */

  152283. {

  152284.    yymsp[-4].minor.yy94 = sqlite3ExprListAppend(pParse, yymsp[-4].minor.yy94, yymsp[-2].minor.yy102);

  152285.    if( yymsp[0].minor.yy0.n>0 ) sqlite3ExprListSetName(pParse, yymsp[-4].minor.yy94, &yymsp[0].minor.yy0, 1);

  152286.    sqlite3ExprListSetSpan(pParse,yymsp[-4].minor.yy94,yymsp[-3].minor.yy528,yymsp[-1].minor.yy528);

  152287. }

  152288.         break;

  152289.       case 97: /* selcollist ::= sclp scanpt STAR */

  152290. {

  152291.   Expr *p = sqlite3Expr(pParse->db, TK_ASTERISK, 0);

  152292.   yymsp[-2].minor.yy94 = sqlite3ExprListAppend(pParse, yymsp[-2].minor.yy94, p);

  152293. }

  152294.         break;

  152295.       case 98: /* selcollist ::= sclp scanpt nm DOT STAR */

  152296. {

  152297.   Expr *pRight = sqlite3PExpr(pParse, TK_ASTERISK, 0, 0);

  152298.   Expr *pLeft = sqlite3ExprAlloc(pParse->db, TK_ID, &yymsp[-2].minor.yy0, 1);

  152299.   Expr *pDot = sqlite3PExpr(pParse, TK_DOT, pLeft, pRight);

  152300.   yymsp[-4].minor.yy94 = sqlite3ExprListAppend(pParse,yymsp[-4].minor.yy94, pDot);

  152301. }

  152302.         break;

  152303.       case 99: /* as ::= AS nm */

  152304.       case 110: /* dbnm ::= DOT nm */ yytestcase(yyruleno==110);

  152305.       case 239: /* plus_num ::= PLUS INTEGER|FLOAT */ yytestcase(yyruleno==239);

  152306.       case 240: /* minus_num ::= MINUS INTEGER|FLOAT */ yytestcase(yyruleno==240);

  152307. {yymsp[-1].minor.yy0 = yymsp[0].minor.yy0;}

  152308.         break;

  152309.       case 101: /* from ::= */

  152310. {yymsp[1].minor.yy407 = sqlite3DbMallocZero(pParse->db, sizeof(*yymsp[1].minor.yy407));}

  152311.         break;

  152312.       case 102: /* from ::= FROM seltablist */

  152313. {

  152314.   yymsp[-1].minor.yy407 = yymsp[0].minor.yy407;

  152315.   sqlite3SrcListShiftJoinType(yymsp[-1].minor.yy407);

  152316. }

  152317.         break;

  152318.       case 103: /* stl_prefix ::= seltablist joinop */

  152319. {

  152320.    if( ALWAYS(yymsp[-1].minor.yy407 && yymsp[-1].minor.yy407->nSrc>0) ) yymsp[-1].minor.yy407->a[yymsp[-1].minor.yy407->nSrc-1].fg.jointype = (u8)yymsp[0].minor.yy100;

  152321. }

  152322.         break;

  152323.       case 104: /* stl_prefix ::= */

  152324. {yymsp[1].minor.yy407 = 0;}

  152325.         break;

  152326.       case 105: /* seltablist ::= stl_prefix nm dbnm as indexed_opt on_opt using_opt */

  152327. {

  152328.   yymsp[-6].minor.yy407 = sqlite3SrcListAppendFromTerm(pParse,yymsp[-6].minor.yy407,&yymsp[-5].minor.yy0,&yymsp[-4].minor.yy0,&yymsp[-3].minor.yy0,0,yymsp[-1].minor.yy102,yymsp[0].minor.yy76);

  152329.   sqlite3SrcListIndexedBy(pParse, yymsp[-6].minor.yy407, &yymsp[-2].minor.yy0);

  152330. }

  152331.         break;

  152332.       case 106: /* seltablist ::= stl_prefix nm dbnm LP exprlist RP as on_opt using_opt */

  152333. {

  152334.   yymsp[-8].minor.yy407 = sqlite3SrcListAppendFromTerm(pParse,yymsp[-8].minor.yy407,&yymsp[-7].minor.yy0,&yymsp[-6].minor.yy0,&yymsp[-2].minor.yy0,0,yymsp[-1].minor.yy102,yymsp[0].minor.yy76);

  152335.   sqlite3SrcListFuncArgs(pParse, yymsp[-8].minor.yy407, yymsp[-4].minor.yy94);

  152336. }

  152337.         break;

  152338.       case 107: /* seltablist ::= stl_prefix LP select RP as on_opt using_opt */

  152339. {

  152340.     yymsp[-6].minor.yy407 = sqlite3SrcListAppendFromTerm(pParse,yymsp[-6].minor.yy407,0,0,&yymsp[-2].minor.yy0,yymsp[-4].minor.yy391,yymsp[-1].minor.yy102,yymsp[0].minor.yy76);

  152341.   }

  152342.         break;

  152343.       case 108: /* seltablist ::= stl_prefix LP seltablist RP as on_opt using_opt */

  152344. {

  152345.     if( yymsp[-6].minor.yy407==0 && yymsp[-2].minor.yy0.n==0 && yymsp[-1].minor.yy102==0 && yymsp[0].minor.yy76==0 ){

  152346.       yymsp[-6].minor.yy407 = yymsp[-4].minor.yy407;

  152347.     }else if( yymsp[-4].minor.yy407->nSrc==1 ){

  152348.       yymsp[-6].minor.yy407 = sqlite3SrcListAppendFromTerm(pParse,yymsp[-6].minor.yy407,0,0,&yymsp[-2].minor.yy0,0,yymsp[-1].minor.yy102,yymsp[0].minor.yy76);

  152349.       if( yymsp[-6].minor.yy407 ){

  152350.         struct SrcList_item *pNew = &yymsp[-6].minor.yy407->a[yymsp[-6].minor.yy407->nSrc-1];

  152351.         struct SrcList_item *pOld = yymsp[-4].minor.yy407->a;

  152352.         pNew->zName = pOld->zName;

  152353.         pNew->zDatabase = pOld->zDatabase;

  152354.         pNew->pSelect = pOld->pSelect;

  152355.         if( pOld->fg.isTabFunc ){

  152356.           pNew->u1.pFuncArg = pOld->u1.pFuncArg;

  152357.           pOld->u1.pFuncArg = 0;

  152358.           pOld->fg.isTabFunc = 0;

  152359.           pNew->fg.isTabFunc = 1;

  152360.         }

  152361.         pOld->zName = pOld->zDatabase = 0;

  152362.         pOld->pSelect = 0;

  152363.       }

  152364.       sqlite3SrcListDelete(pParse->db, yymsp[-4].minor.yy407);

  152365.     }else{

  152366.       Select *pSubquery;

  152367.       sqlite3SrcListShiftJoinType(yymsp[-4].minor.yy407);

  152368.       pSubquery = sqlite3SelectNew(pParse,0,yymsp[-4].minor.yy407,0,0,0,0,SF_NestedFrom,0);

  152369.       yymsp[-6].minor.yy407 = sqlite3SrcListAppendFromTerm(pParse,yymsp[-6].minor.yy407,0,0,&yymsp[-2].minor.yy0,pSubquery,yymsp[-1].minor.yy102,yymsp[0].minor.yy76);

  152370.     }

  152371.   }

  152372.         break;

  152373.       case 109: /* dbnm ::= */

  152374.       case 123: /* indexed_opt ::= */ yytestcase(yyruleno==123);

  152375. {yymsp[1].minor.yy0.z=0; yymsp[1].minor.yy0.n=0;}

  152376.         break;

  152377.       case 111: /* fullname ::= nm */

  152378. {

  152379.   yylhsminor.yy407 = sqlite3SrcListAppend(pParse,0,&yymsp[0].minor.yy0,0);

  152380.   if( IN_RENAME_OBJECT && yylhsminor.yy407 ) sqlite3RenameTokenMap(pParse, yylhsminor.yy407->a[0].zName, &yymsp[0].minor.yy0);

  152381. }

  152382.   yymsp[0].minor.yy407 = yylhsminor.yy407;

  152383.         break;

  152384.       case 112: /* fullname ::= nm DOT nm */

  152385. {

  152386.   yylhsminor.yy407 = sqlite3SrcListAppend(pParse,0,&yymsp[-2].minor.yy0,&yymsp[0].minor.yy0);

  152387.   if( IN_RENAME_OBJECT && yylhsminor.yy407 ) sqlite3RenameTokenMap(pParse, yylhsminor.yy407->a[0].zName, &yymsp[0].minor.yy0);

  152388. }

  152389.   yymsp[-2].minor.yy407 = yylhsminor.yy407;

  152390.         break;

  152391.       case 113: /* xfullname ::= nm */

  152392. {yymsp[0].minor.yy407 = sqlite3SrcListAppend(pParse,0,&yymsp[0].minor.yy0,0); /*A-overwrites-X*/}

  152393.         break;

  152394.       case 114: /* xfullname ::= nm DOT nm */

  152395. {yymsp[-2].minor.yy407 = sqlite3SrcListAppend(pParse,0,&yymsp[-2].minor.yy0,&yymsp[0].minor.yy0); /*A-overwrites-X*/}

  152396.         break;

  152397.       case 115: /* xfullname ::= nm DOT nm AS nm */

  152398. {

  152399.    yymsp[-4].minor.yy407 = sqlite3SrcListAppend(pParse,0,&yymsp[-4].minor.yy0,&yymsp[-2].minor.yy0); /*A-overwrites-X*/

  152400.    if( yymsp[-4].minor.yy407 ) yymsp[-4].minor.yy407->a[0].zAlias = sqlite3NameFromToken(pParse->db, &yymsp[0].minor.yy0);

  152401. }

  152402.         break;

  152403.       case 116: /* xfullname ::= nm AS nm */

  152404. {  

  152405.    yymsp[-2].minor.yy407 = sqlite3SrcListAppend(pParse,0,&yymsp[-2].minor.yy0,0); /*A-overwrites-X*/

  152406.    if( yymsp[-2].minor.yy407 ) yymsp[-2].minor.yy407->a[0].zAlias = sqlite3NameFromToken(pParse->db, &yymsp[0].minor.yy0);

  152407. }

  152408.         break;

  152409.       case 117: /* joinop ::= COMMA|JOIN */

  152410. { yymsp[0].minor.yy100 = JT_INNER; }

  152411.         break;

  152412.       case 118: /* joinop ::= JOIN_KW JOIN */

  152413. {yymsp[-1].minor.yy100 = sqlite3JoinType(pParse,&yymsp[-1].minor.yy0,0,0);  /*X-overwrites-A*/}

  152414.         break;

  152415.       case 119: /* joinop ::= JOIN_KW nm JOIN */

  152416. {yymsp[-2].minor.yy100 = sqlite3JoinType(pParse,&yymsp[-2].minor.yy0,&yymsp[-1].minor.yy0,0); /*X-overwrites-A*/}

  152417.         break;

  152418.       case 120: /* joinop ::= JOIN_KW nm nm JOIN */

  152419. {yymsp[-3].minor.yy100 = sqlite3JoinType(pParse,&yymsp[-3].minor.yy0,&yymsp[-2].minor.yy0,&yymsp[-1].minor.yy0);/*X-overwrites-A*/}

  152420.         break;

  152421.       case 121: /* on_opt ::= ON expr */

  152422.       case 138: /* having_opt ::= HAVING expr */ yytestcase(yyruleno==138);

  152423.       case 145: /* where_opt ::= WHERE expr */ yytestcase(yyruleno==145);

  152424.       case 211: /* case_else ::= ELSE expr */ yytestcase(yyruleno==211);

  152425.       case 232: /* vinto ::= INTO expr */ yytestcase(yyruleno==232);

  152426. {yymsp[-1].minor.yy102 = yymsp[0].minor.yy102;}

  152427.         break;

  152428.       case 122: /* on_opt ::= */

  152429.       case 137: /* having_opt ::= */ yytestcase(yyruleno==137);

  152430.       case 139: /* limit_opt ::= */ yytestcase(yyruleno==139);

  152431.       case 144: /* where_opt ::= */ yytestcase(yyruleno==144);

  152432.       case 212: /* case_else ::= */ yytestcase(yyruleno==212);

  152433.       case 214: /* case_operand ::= */ yytestcase(yyruleno==214);

  152434.       case 233: /* vinto ::= */ yytestcase(yyruleno==233);

  152435. {yymsp[1].minor.yy102 = 0;}

  152436.         break;

  152437.       case 124: /* indexed_opt ::= INDEXED BY nm */

  152438. {yymsp[-2].minor.yy0 = yymsp[0].minor.yy0;}

  152439.         break;

  152440.       case 125: /* indexed_opt ::= NOT INDEXED */

  152441. {yymsp[-1].minor.yy0.z=0; yymsp[-1].minor.yy0.n=1;}

  152442.         break;

  152443.       case 126: /* using_opt ::= USING LP idlist RP */

  152444. {yymsp[-3].minor.yy76 = yymsp[-1].minor.yy76;}

  152445.         break;

  152446.       case 127: /* using_opt ::= */

  152447.       case 159: /* idlist_opt ::= */ yytestcase(yyruleno==159);

  152448. {yymsp[1].minor.yy76 = 0;}

  152449.         break;

  152450.       case 129: /* orderby_opt ::= ORDER BY sortlist */

  152451.       case 136: /* groupby_opt ::= GROUP BY nexprlist */ yytestcase(yyruleno==136);

  152452. {yymsp[-2].minor.yy94 = yymsp[0].minor.yy94;}

  152453.         break;

  152454.       case 130: /* sortlist ::= sortlist COMMA expr sortorder */

  152455. {

  152456.   yymsp[-3].minor.yy94 = sqlite3ExprListAppend(pParse,yymsp[-3].minor.yy94,yymsp[-1].minor.yy102);

  152457.   sqlite3ExprListSetSortOrder(yymsp[-3].minor.yy94,yymsp[0].minor.yy100);

  152458. }

  152459.         break;

  152460.       case 131: /* sortlist ::= expr sortorder */

  152461. {

  152462.   yymsp[-1].minor.yy94 = sqlite3ExprListAppend(pParse,0,yymsp[-1].minor.yy102); /*A-overwrites-Y*/

  152463.   sqlite3ExprListSetSortOrder(yymsp[-1].minor.yy94,yymsp[0].minor.yy100);

  152464. }

  152465.         break;

  152466.       case 132: /* sortorder ::= ASC */

  152467. {yymsp[0].minor.yy100 = SQLITE_SO_ASC;}

  152468.         break;

  152469.       case 133: /* sortorder ::= DESC */

  152470. {yymsp[0].minor.yy100 = SQLITE_SO_DESC;}

  152471.         break;

  152472.       case 134: /* sortorder ::= */

  152473. {yymsp[1].minor.yy100 = SQLITE_SO_UNDEFINED;}

  152474.         break;

  152475.       case 140: /* limit_opt ::= LIMIT expr */

  152476. {yymsp[-1].minor.yy102 = sqlite3PExpr(pParse,TK_LIMIT,yymsp[0].minor.yy102,0);}

  152477.         break;

  152478.       case 141: /* limit_opt ::= LIMIT expr OFFSET expr */

  152479. {yymsp[-3].minor.yy102 = sqlite3PExpr(pParse,TK_LIMIT,yymsp[-2].minor.yy102,yymsp[0].minor.yy102);}

  152480.         break;

  152481.       case 142: /* limit_opt ::= LIMIT expr COMMA expr */

  152482. {yymsp[-3].minor.yy102 = sqlite3PExpr(pParse,TK_LIMIT,yymsp[0].minor.yy102,yymsp[-2].minor.yy102);}

  152483.         break;

  152484.       case 143: /* cmd ::= with DELETE FROM xfullname indexed_opt where_opt */

  152485. {

  152486.   sqlite3SrcListIndexedBy(pParse, yymsp[-2].minor.yy407, &yymsp[-1].minor.yy0);

  152487.   sqlite3DeleteFrom(pParse,yymsp[-2].minor.yy407,yymsp[0].minor.yy102,0,0);

  152488. }

  152489.         break;

  152490.       case 146: /* cmd ::= with UPDATE orconf xfullname indexed_opt SET setlist where_opt */

  152491. {

  152492.   sqlite3SrcListIndexedBy(pParse, yymsp[-4].minor.yy407, &yymsp[-3].minor.yy0);

  152493.   sqlite3ExprListCheckLength(pParse,yymsp[-1].minor.yy94,"set list"); 

  152494.   sqlite3Update(pParse,yymsp[-4].minor.yy407,yymsp[-1].minor.yy94,yymsp[0].minor.yy102,yymsp[-5].minor.yy100,0,0,0);

  152495. }

  152496.         break;

  152497.       case 147: /* setlist ::= setlist COMMA nm EQ expr */

  152498. {

  152499.   yymsp[-4].minor.yy94 = sqlite3ExprListAppend(pParse, yymsp[-4].minor.yy94, yymsp[0].minor.yy102);

  152500.   sqlite3ExprListSetName(pParse, yymsp[-4].minor.yy94, &yymsp[-2].minor.yy0, 1);

  152501. }

  152502.         break;

  152503.       case 148: /* setlist ::= setlist COMMA LP idlist RP EQ expr */

  152504. {

  152505.   yymsp[-6].minor.yy94 = sqlite3ExprListAppendVector(pParse, yymsp[-6].minor.yy94, yymsp[-3].minor.yy76, yymsp[0].minor.yy102);

  152506. }

  152507.         break;

  152508.       case 149: /* setlist ::= nm EQ expr */

  152509. {

  152510.   yylhsminor.yy94 = sqlite3ExprListAppend(pParse, 0, yymsp[0].minor.yy102);

  152511.   sqlite3ExprListSetName(pParse, yylhsminor.yy94, &yymsp[-2].minor.yy0, 1);

  152512. }

  152513.   yymsp[-2].minor.yy94 = yylhsminor.yy94;

  152514.         break;

  152515.       case 150: /* setlist ::= LP idlist RP EQ expr */

  152516. {

  152517.   yymsp[-4].minor.yy94 = sqlite3ExprListAppendVector(pParse, 0, yymsp[-3].minor.yy76, yymsp[0].minor.yy102);

  152518. }

  152519.         break;

  152520.       case 151: /* cmd ::= with insert_cmd INTO xfullname idlist_opt select upsert */

  152521. {

  152522.   sqlite3Insert(pParse, yymsp[-3].minor.yy407, yymsp[-1].minor.yy391, yymsp[-2].minor.yy76, yymsp[-5].minor.yy100, yymsp[0].minor.yy95);

  152523. }

  152524.         break;

  152525.       case 152: /* cmd ::= with insert_cmd INTO xfullname idlist_opt DEFAULT VALUES */

  152526. {

  152527.   sqlite3Insert(pParse, yymsp[-3].minor.yy407, 0, yymsp[-2].minor.yy76, yymsp[-5].minor.yy100, 0);

  152528. }

  152529.         break;

  152530.       case 153: /* upsert ::= */

  152531. { yymsp[1].minor.yy95 = 0; }

  152532.         break;

  152533.       case 154: /* upsert ::= ON CONFLICT LP sortlist RP where_opt DO UPDATE SET setlist where_opt */

  152534. { yymsp[-10].minor.yy95 = sqlite3UpsertNew(pParse->db,yymsp[-7].minor.yy94,yymsp[-5].minor.yy102,yymsp[-1].minor.yy94,yymsp[0].minor.yy102);}

  152535.         break;

  152536.       case 155: /* upsert ::= ON CONFLICT LP sortlist RP where_opt DO NOTHING */

  152537. { yymsp[-7].minor.yy95 = sqlite3UpsertNew(pParse->db,yymsp[-4].minor.yy94,yymsp[-2].minor.yy102,0,0); }

  152538.         break;

  152539.       case 156: /* upsert ::= ON CONFLICT DO NOTHING */

  152540. { yymsp[-3].minor.yy95 = sqlite3UpsertNew(pParse->db,0,0,0,0); }

  152541.         break;

  152542.       case 160: /* idlist_opt ::= LP idlist RP */

  152543. {yymsp[-2].minor.yy76 = yymsp[-1].minor.yy76;}

  152544.         break;

  152545.       case 161: /* idlist ::= idlist COMMA nm */

  152546. {yymsp[-2].minor.yy76 = sqlite3IdListAppend(pParse,yymsp[-2].minor.yy76,&yymsp[0].minor.yy0);}

  152547.         break;

  152548.       case 162: /* idlist ::= nm */

  152549. {yymsp[0].minor.yy76 = sqlite3IdListAppend(pParse,0,&yymsp[0].minor.yy0); /*A-overwrites-Y*/}

  152550.         break;

  152551.       case 163: /* expr ::= LP expr RP */

  152552. {yymsp[-2].minor.yy102 = yymsp[-1].minor.yy102;}

  152553.         break;

  152554.       case 164: /* expr ::= ID|INDEXED */

  152555.       case 165: /* expr ::= JOIN_KW */ yytestcase(yyruleno==165);

  152556. {yymsp[0].minor.yy102=tokenExpr(pParse,TK_ID,yymsp[0].minor.yy0); /*A-overwrites-X*/}

  152557.         break;

  152558.       case 166: /* expr ::= nm DOT nm */

  152559. {

  152560.   Expr *temp1 = sqlite3ExprAlloc(pParse->db, TK_ID, &yymsp[-2].minor.yy0, 1);

  152561.   Expr *temp2 = sqlite3ExprAlloc(pParse->db, TK_ID, &yymsp[0].minor.yy0, 1);

  152562.   if( IN_RENAME_OBJECT ){

  152563.     sqlite3RenameTokenMap(pParse, (void*)temp2, &yymsp[0].minor.yy0);

  152564.     sqlite3RenameTokenMap(pParse, (void*)temp1, &yymsp[-2].minor.yy0);

  152565.   }

  152566.   yylhsminor.yy102 = sqlite3PExpr(pParse, TK_DOT, temp1, temp2);

  152567. }

  152568.   yymsp[-2].minor.yy102 = yylhsminor.yy102;

  152569.         break;

  152570.       case 167: /* expr ::= nm DOT nm DOT nm */

  152571. {

  152572.   Expr *temp1 = sqlite3ExprAlloc(pParse->db, TK_ID, &yymsp[-4].minor.yy0, 1);

  152573.   Expr *temp2 = sqlite3ExprAlloc(pParse->db, TK_ID, &yymsp[-2].minor.yy0, 1);

  152574.   Expr *temp3 = sqlite3ExprAlloc(pParse->db, TK_ID, &yymsp[0].minor.yy0, 1);

  152575.   Expr *temp4 = sqlite3PExpr(pParse, TK_DOT, temp2, temp3);

  152576.   if( IN_RENAME_OBJECT ){

  152577.     sqlite3RenameTokenMap(pParse, (void*)temp3, &yymsp[0].minor.yy0);

  152578.     sqlite3RenameTokenMap(pParse, (void*)temp2, &yymsp[-2].minor.yy0);

  152579.   }

  152580.   yylhsminor.yy102 = sqlite3PExpr(pParse, TK_DOT, temp1, temp4);

  152581. }

  152582.   yymsp[-4].minor.yy102 = yylhsminor.yy102;

  152583.         break;

  152584.       case 168: /* term ::= NULL|FLOAT|BLOB */

  152585.       case 169: /* term ::= STRING */ yytestcase(yyruleno==169);

  152586. {yymsp[0].minor.yy102=tokenExpr(pParse,yymsp[0].major,yymsp[0].minor.yy0); /*A-overwrites-X*/}

  152587.         break;

  152588.       case 170: /* term ::= INTEGER */

  152589. {

  152590.   yylhsminor.yy102 = sqlite3ExprAlloc(pParse->db, TK_INTEGER, &yymsp[0].minor.yy0, 1);

  152591. }

  152592.   yymsp[0].minor.yy102 = yylhsminor.yy102;

  152593.         break;

  152594.       case 171: /* expr ::= VARIABLE */

  152595. {

  152596.   if( !(yymsp[0].minor.yy0.z[0]=='#' && sqlite3Isdigit(yymsp[0].minor.yy0.z[1])) ){

  152597.     u32 n = yymsp[0].minor.yy0.n;

  152598.     yymsp[0].minor.yy102 = tokenExpr(pParse, TK_VARIABLE, yymsp[0].minor.yy0);

  152599.     sqlite3ExprAssignVarNumber(pParse, yymsp[0].minor.yy102, n);

  152600.   }else{

  152601.     /* When doing a nested parse, one can include terms in an expression

  152602.     ** that look like this:   #1 #2 ...  These terms refer to registers

  152603.     ** in the virtual machine.  #N is the N-th register. */

  152604.     Token t = yymsp[0].minor.yy0; /*A-overwrites-X*/

  152605.     assert( t.n>=2 );

  152606.     if( pParse->nested==0 ){

  152607.       sqlite3ErrorMsg(pParse, "near \"%T\": syntax error", &t);

  152608.       yymsp[0].minor.yy102 = 0;

  152609.     }else{

  152610.       yymsp[0].minor.yy102 = sqlite3PExpr(pParse, TK_REGISTER, 0, 0);

  152611.       if( yymsp[0].minor.yy102 ) sqlite3GetInt32(&t.z[1], &yymsp[0].minor.yy102->iTable);

  152612.     }

  152613.   }

  152614. }

  152615.         break;

  152616.       case 172: /* expr ::= expr COLLATE ID|STRING */

  152617. {

  152618.   yymsp[-2].minor.yy102 = sqlite3ExprAddCollateToken(pParse, yymsp[-2].minor.yy102, &yymsp[0].minor.yy0, 1);

  152619. }

  152620.         break;

  152621.       case 173: /* expr ::= CAST LP expr AS typetoken RP */

  152622. {

  152623.   yymsp[-5].minor.yy102 = sqlite3ExprAlloc(pParse->db, TK_CAST, &yymsp[-1].minor.yy0, 1);

  152624.   sqlite3ExprAttachSubtrees(pParse->db, yymsp[-5].minor.yy102, yymsp[-3].minor.yy102, 0);

  152625. }

  152626.         break;

  152627.       case 174: /* expr ::= ID|INDEXED LP distinct exprlist RP */

  152628. {

  152629.   yylhsminor.yy102 = sqlite3ExprFunction(pParse, yymsp[-1].minor.yy94, &yymsp[-4].minor.yy0, yymsp[-2].minor.yy100);

  152630. }

  152631.   yymsp[-4].minor.yy102 = yylhsminor.yy102;

  152632.         break;

  152633.       case 175: /* expr ::= ID|INDEXED LP STAR RP */

  152634. {

  152635.   yylhsminor.yy102 = sqlite3ExprFunction(pParse, 0, &yymsp[-3].minor.yy0, 0);

  152636. }

  152637.   yymsp[-3].minor.yy102 = yylhsminor.yy102;

  152638.         break;

  152639.       case 176: /* expr ::= ID|INDEXED LP distinct exprlist RP over_clause */

  152640. {

  152641.   yylhsminor.yy102 = sqlite3ExprFunction(pParse, yymsp[-2].minor.yy94, &yymsp[-5].minor.yy0, yymsp[-3].minor.yy100);

  152642.   sqlite3WindowAttach(pParse, yylhsminor.yy102, yymsp[0].minor.yy379);

  152643. }

  152644.   yymsp[-5].minor.yy102 = yylhsminor.yy102;

  152645.         break;

  152646.       case 177: /* expr ::= ID|INDEXED LP STAR RP over_clause */

  152647. {

  152648.   yylhsminor.yy102 = sqlite3ExprFunction(pParse, 0, &yymsp[-4].minor.yy0, 0);

  152649.   sqlite3WindowAttach(pParse, yylhsminor.yy102, yymsp[0].minor.yy379);

  152650. }

  152651.   yymsp[-4].minor.yy102 = yylhsminor.yy102;

  152652.         break;

  152653.       case 178: /* term ::= CTIME_KW */

  152654. {

  152655.   yylhsminor.yy102 = sqlite3ExprFunction(pParse, 0, &yymsp[0].minor.yy0, 0);

  152656. }

  152657.   yymsp[0].minor.yy102 = yylhsminor.yy102;

  152658.         break;

  152659.       case 179: /* expr ::= LP nexprlist COMMA expr RP */

  152660. {

  152661.   ExprList *pList = sqlite3ExprListAppend(pParse, yymsp[-3].minor.yy94, yymsp[-1].minor.yy102);

  152662.   yymsp[-4].minor.yy102 = sqlite3PExpr(pParse, TK_VECTOR, 0, 0);

  152663.   if( yymsp[-4].minor.yy102 ){

  152664.     yymsp[-4].minor.yy102->x.pList = pList;

  152665.   }else{

  152666.     sqlite3ExprListDelete(pParse->db, pList);

  152667.   }

  152668. }

  152669.         break;

  152670.       case 180: /* expr ::= expr AND expr */

  152671. {yymsp[-2].minor.yy102=sqlite3ExprAnd(pParse,yymsp[-2].minor.yy102,yymsp[0].minor.yy102);}

  152672.         break;

  152673.       case 181: /* expr ::= expr OR expr */

  152674.       case 182: /* expr ::= expr LT|GT|GE|LE expr */ yytestcase(yyruleno==182);

  152675.       case 183: /* expr ::= expr EQ|NE expr */ yytestcase(yyruleno==183);

  152676.       case 184: /* expr ::= expr BITAND|BITOR|LSHIFT|RSHIFT expr */ yytestcase(yyruleno==184);

  152677.       case 185: /* expr ::= expr PLUS|MINUS expr */ yytestcase(yyruleno==185);

  152678.       case 186: /* expr ::= expr STAR|SLASH|REM expr */ yytestcase(yyruleno==186);

  152679.       case 187: /* expr ::= expr CONCAT expr */ yytestcase(yyruleno==187);

  152680. {yymsp[-2].minor.yy102=sqlite3PExpr(pParse,yymsp[-1].major,yymsp[-2].minor.yy102,yymsp[0].minor.yy102);}

  152681.         break;

  152682.       case 188: /* likeop ::= NOT LIKE_KW|MATCH */

  152683. {yymsp[-1].minor.yy0=yymsp[0].minor.yy0; yymsp[-1].minor.yy0.n|=0x80000000; /*yymsp[-1].minor.yy0-overwrite-yymsp[0].minor.yy0*/}

  152684.         break;

  152685.       case 189: /* expr ::= expr likeop expr */

  152686. {

  152687.   ExprList *pList;

  152688.   int bNot = yymsp[-1].minor.yy0.n & 0x80000000;

  152689.   yymsp[-1].minor.yy0.n &= 0x7fffffff;

  152690.   pList = sqlite3ExprListAppend(pParse,0, yymsp[0].minor.yy102);

  152691.   pList = sqlite3ExprListAppend(pParse,pList, yymsp[-2].minor.yy102);

  152692.   yymsp[-2].minor.yy102 = sqlite3ExprFunction(pParse, pList, &yymsp[-1].minor.yy0, 0);

  152693.   if( bNot ) yymsp[-2].minor.yy102 = sqlite3PExpr(pParse, TK_NOT, yymsp[-2].minor.yy102, 0);

  152694.   if( yymsp[-2].minor.yy102 ) yymsp[-2].minor.yy102->flags |= EP_InfixFunc;

  152695. }

  152696.         break;

  152697.       case 190: /* expr ::= expr likeop expr ESCAPE expr */

  152698. {

  152699.   ExprList *pList;

  152700.   int bNot = yymsp[-3].minor.yy0.n & 0x80000000;

  152701.   yymsp[-3].minor.yy0.n &= 0x7fffffff;

  152702.   pList = sqlite3ExprListAppend(pParse,0, yymsp[-2].minor.yy102);

  152703.   pList = sqlite3ExprListAppend(pParse,pList, yymsp[-4].minor.yy102);

  152704.   pList = sqlite3ExprListAppend(pParse,pList, yymsp[0].minor.yy102);

  152705.   yymsp[-4].minor.yy102 = sqlite3ExprFunction(pParse, pList, &yymsp[-3].minor.yy0, 0);

  152706.   if( bNot ) yymsp[-4].minor.yy102 = sqlite3PExpr(pParse, TK_NOT, yymsp[-4].minor.yy102, 0);

  152707.   if( yymsp[-4].minor.yy102 ) yymsp[-4].minor.yy102->flags |= EP_InfixFunc;

  152708. }

  152709.         break;

  152710.       case 191: /* expr ::= expr ISNULL|NOTNULL */

  152711. {yymsp[-1].minor.yy102 = sqlite3PExpr(pParse,yymsp[0].major,yymsp[-1].minor.yy102,0);}

  152712.         break;

  152713.       case 192: /* expr ::= expr NOT NULL */

  152714. {yymsp[-2].minor.yy102 = sqlite3PExpr(pParse,TK_NOTNULL,yymsp[-2].minor.yy102,0);}

  152715.         break;

  152716.       case 193: /* expr ::= expr IS expr */

  152717. {

  152718.   yymsp[-2].minor.yy102 = sqlite3PExpr(pParse,TK_IS,yymsp[-2].minor.yy102,yymsp[0].minor.yy102);

  152719.   binaryToUnaryIfNull(pParse, yymsp[0].minor.yy102, yymsp[-2].minor.yy102, TK_ISNULL);

  152720. }

  152721.         break;

  152722.       case 194: /* expr ::= expr IS NOT expr */

  152723. {

  152724.   yymsp[-3].minor.yy102 = sqlite3PExpr(pParse,TK_ISNOT,yymsp[-3].minor.yy102,yymsp[0].minor.yy102);

  152725.   binaryToUnaryIfNull(pParse, yymsp[0].minor.yy102, yymsp[-3].minor.yy102, TK_NOTNULL);

  152726. }

  152727.         break;

  152728.       case 195: /* expr ::= NOT expr */

  152729.       case 196: /* expr ::= BITNOT expr */ yytestcase(yyruleno==196);

  152730. {yymsp[-1].minor.yy102 = sqlite3PExpr(pParse, yymsp[-1].major, yymsp[0].minor.yy102, 0);/*A-overwrites-B*/}

  152731.         break;

  152732.       case 197: /* expr ::= PLUS|MINUS expr */

  152733. {

  152734.   yymsp[-1].minor.yy102 = sqlite3PExpr(pParse, yymsp[-1].major==TK_PLUS ? TK_UPLUS : TK_UMINUS, yymsp[0].minor.yy102, 0);

  152735.   /*A-overwrites-B*/

  152736. }

  152737.         break;

  152738.       case 198: /* between_op ::= BETWEEN */

  152739.       case 201: /* in_op ::= IN */ yytestcase(yyruleno==201);

  152740. {yymsp[0].minor.yy100 = 0;}

  152741.         break;

  152742.       case 200: /* expr ::= expr between_op expr AND expr */

  152743. {

  152744.   ExprList *pList = sqlite3ExprListAppend(pParse,0, yymsp[-2].minor.yy102);

  152745.   pList = sqlite3ExprListAppend(pParse,pList, yymsp[0].minor.yy102);

  152746.   yymsp[-4].minor.yy102 = sqlite3PExpr(pParse, TK_BETWEEN, yymsp[-4].minor.yy102, 0);

  152747.   if( yymsp[-4].minor.yy102 ){

  152748.     yymsp[-4].minor.yy102->x.pList = pList;

  152749.   }else{

  152750.     sqlite3ExprListDelete(pParse->db, pList);

  152751.   } 

  152752.   if( yymsp[-3].minor.yy100 ) yymsp[-4].minor.yy102 = sqlite3PExpr(pParse, TK_NOT, yymsp[-4].minor.yy102, 0);

  152753. }

  152754.         break;

  152755.       case 203: /* expr ::= expr in_op LP exprlist RP */

  152756. {

  152757.     if( yymsp[-1].minor.yy94==0 ){

  152758.       /* Expressions of the form

  152759.       **

  152760.       **      expr1 IN ()

  152761.       **      expr1 NOT IN ()

  152762.       **

  152763.       ** simplify to constants 0 (false) and 1 (true), respectively,

  152764.       ** regardless of the value of expr1.

  152765.       */

  152766.       sqlite3ExprUnmapAndDelete(pParse, yymsp[-4].minor.yy102);

  152767.       yymsp[-4].minor.yy102 = sqlite3ExprAlloc(pParse->db, TK_INTEGER,&sqlite3IntTokens[yymsp[-3].minor.yy100],1);

  152768.     }else if( yymsp[-1].minor.yy94->nExpr==1 ){

  152769.       /* Expressions of the form:

  152770.       **

  152771.       **      expr1 IN (?1)

  152772.       **      expr1 NOT IN (?2)

  152773.       **

  152774.       ** with exactly one value on the RHS can be simplified to something

  152775.       ** like this:

  152776.       **

  152777.       **      expr1 == ?1

  152778.       **      expr1 <> ?2

  152779.       **

  152780.       ** But, the RHS of the == or <> is marked with the EP_Generic flag

  152781.       ** so that it may not contribute to the computation of comparison

  152782.       ** affinity or the collating sequence to use for comparison.  Otherwise,

  152783.       ** the semantics would be subtly different from IN or NOT IN.

  152784.       */

  152785.       Expr *pRHS = yymsp[-1].minor.yy94->a[0].pExpr;

  152786.       yymsp[-1].minor.yy94->a[0].pExpr = 0;

  152787.       sqlite3ExprListDelete(pParse->db, yymsp[-1].minor.yy94);

  152788.       /* pRHS cannot be NULL because a malloc error would have been detected

  152789.       ** before now and control would have never reached this point */

  152790.       if( ALWAYS(pRHS) ){

  152791.         pRHS->flags &= ~EP_Collate;

  152792.         pRHS->flags |= EP_Generic;

  152793.       }

  152794.       yymsp[-4].minor.yy102 = sqlite3PExpr(pParse, yymsp[-3].minor.yy100 ? TK_NE : TK_EQ, yymsp[-4].minor.yy102, pRHS);

  152795.     }else{

  152796.       yymsp[-4].minor.yy102 = sqlite3PExpr(pParse, TK_IN, yymsp[-4].minor.yy102, 0);

  152797.       if( yymsp[-4].minor.yy102 ){

  152798.         yymsp[-4].minor.yy102->x.pList = yymsp[-1].minor.yy94;

  152799.         sqlite3ExprSetHeightAndFlags(pParse, yymsp[-4].minor.yy102);

  152800.       }else{

  152801.         sqlite3ExprListDelete(pParse->db, yymsp[-1].minor.yy94);

  152802.       }

  152803.       if( yymsp[-3].minor.yy100 ) yymsp[-4].minor.yy102 = sqlite3PExpr(pParse, TK_NOT, yymsp[-4].minor.yy102, 0);

  152804.     }

  152805.   }

  152806.         break;

  152807.       case 204: /* expr ::= LP select RP */

  152808. {

  152809.     yymsp[-2].minor.yy102 = sqlite3PExpr(pParse, TK_SELECT, 0, 0);

  152810.     sqlite3PExprAddSelect(pParse, yymsp[-2].minor.yy102, yymsp[-1].minor.yy391);

  152811.   }

  152812.         break;

  152813.       case 205: /* expr ::= expr in_op LP select RP */

  152814. {

  152815.     yymsp[-4].minor.yy102 = sqlite3PExpr(pParse, TK_IN, yymsp[-4].minor.yy102, 0);

  152816.     sqlite3PExprAddSelect(pParse, yymsp[-4].minor.yy102, yymsp[-1].minor.yy391);

  152817.     if( yymsp[-3].minor.yy100 ) yymsp[-4].minor.yy102 = sqlite3PExpr(pParse, TK_NOT, yymsp[-4].minor.yy102, 0);

  152818.   }

  152819.         break;

  152820.       case 206: /* expr ::= expr in_op nm dbnm paren_exprlist */

  152821. {

  152822.     SrcList *pSrc = sqlite3SrcListAppend(pParse, 0,&yymsp[-2].minor.yy0,&yymsp[-1].minor.yy0);

  152823.     Select *pSelect = sqlite3SelectNew(pParse, 0,pSrc,0,0,0,0,0,0);

  152824.     if( yymsp[0].minor.yy94 )  sqlite3SrcListFuncArgs(pParse, pSelect ? pSrc : 0, yymsp[0].minor.yy94);

  152825.     yymsp[-4].minor.yy102 = sqlite3PExpr(pParse, TK_IN, yymsp[-4].minor.yy102, 0);

  152826.     sqlite3PExprAddSelect(pParse, yymsp[-4].minor.yy102, pSelect);

  152827.     if( yymsp[-3].minor.yy100 ) yymsp[-4].minor.yy102 = sqlite3PExpr(pParse, TK_NOT, yymsp[-4].minor.yy102, 0);

  152828.   }

  152829.         break;

  152830.       case 207: /* expr ::= EXISTS LP select RP */

  152831. {

  152832.     Expr *p;

  152833.     p = yymsp[-3].minor.yy102 = sqlite3PExpr(pParse, TK_EXISTS, 0, 0);

  152834.     sqlite3PExprAddSelect(pParse, p, yymsp[-1].minor.yy391);

  152835.   }

  152836.         break;

  152837.       case 208: /* expr ::= CASE case_operand case_exprlist case_else END */

  152838. {

  152839.   yymsp[-4].minor.yy102 = sqlite3PExpr(pParse, TK_CASE, yymsp[-3].minor.yy102, 0);

  152840.   if( yymsp[-4].minor.yy102 ){

  152841.     yymsp[-4].minor.yy102->x.pList = yymsp[-1].minor.yy102 ? sqlite3ExprListAppend(pParse,yymsp[-2].minor.yy94,yymsp[-1].minor.yy102) : yymsp[-2].minor.yy94;

  152842.     sqlite3ExprSetHeightAndFlags(pParse, yymsp[-4].minor.yy102);

  152843.   }else{

  152844.     sqlite3ExprListDelete(pParse->db, yymsp[-2].minor.yy94);

  152845.     sqlite3ExprDelete(pParse->db, yymsp[-1].minor.yy102);

  152846.   }

  152847. }

  152848.         break;

  152849.       case 209: /* case_exprlist ::= case_exprlist WHEN expr THEN expr */

  152850. {

  152851.   yymsp[-4].minor.yy94 = sqlite3ExprListAppend(pParse,yymsp[-4].minor.yy94, yymsp[-2].minor.yy102);

  152852.   yymsp[-4].minor.yy94 = sqlite3ExprListAppend(pParse,yymsp[-4].minor.yy94, yymsp[0].minor.yy102);

  152853. }

  152854.         break;

  152855.       case 210: /* case_exprlist ::= WHEN expr THEN expr */

  152856. {

  152857.   yymsp[-3].minor.yy94 = sqlite3ExprListAppend(pParse,0, yymsp[-2].minor.yy102);

  152858.   yymsp[-3].minor.yy94 = sqlite3ExprListAppend(pParse,yymsp[-3].minor.yy94, yymsp[0].minor.yy102);

  152859. }

  152860.         break;

  152861.       case 213: /* case_operand ::= expr */

  152862. {yymsp[0].minor.yy102 = yymsp[0].minor.yy102; /*A-overwrites-X*/}

  152863.         break;

  152864.       case 216: /* nexprlist ::= nexprlist COMMA expr */

  152865. {yymsp[-2].minor.yy94 = sqlite3ExprListAppend(pParse,yymsp[-2].minor.yy94,yymsp[0].minor.yy102);}

  152866.         break;

  152867.       case 217: /* nexprlist ::= expr */

  152868. {yymsp[0].minor.yy94 = sqlite3ExprListAppend(pParse,0,yymsp[0].minor.yy102); /*A-overwrites-Y*/}

  152869.         break;

  152870.       case 219: /* paren_exprlist ::= LP exprlist RP */

  152871.       case 224: /* eidlist_opt ::= LP eidlist RP */ yytestcase(yyruleno==224);

  152872. {yymsp[-2].minor.yy94 = yymsp[-1].minor.yy94;}

  152873.         break;

  152874.       case 220: /* cmd ::= createkw uniqueflag INDEX ifnotexists nm dbnm ON nm LP sortlist RP where_opt */

  152875. {

  152876.   sqlite3CreateIndex(pParse, &yymsp[-7].minor.yy0, &yymsp[-6].minor.yy0, 

  152877.                      sqlite3SrcListAppend(pParse,0,&yymsp[-4].minor.yy0,0), yymsp[-2].minor.yy94, yymsp[-10].minor.yy100,

  152878.                       &yymsp[-11].minor.yy0, yymsp[0].minor.yy102, SQLITE_SO_ASC, yymsp[-8].minor.yy100, SQLITE_IDXTYPE_APPDEF);

  152879.   if( IN_RENAME_OBJECT && pParse->pNewIndex ){

  152880.     sqlite3RenameTokenMap(pParse, pParse->pNewIndex->zName, &yymsp[-4].minor.yy0);

  152881.   }

  152882. }

  152883.         break;

  152884.       case 221: /* uniqueflag ::= UNIQUE */

  152885.       case 263: /* raisetype ::= ABORT */ yytestcase(yyruleno==263);

  152886. {yymsp[0].minor.yy100 = OE_Abort;}

  152887.         break;

  152888.       case 222: /* uniqueflag ::= */

  152889. {yymsp[1].minor.yy100 = OE_None;}

  152890.         break;

  152891.       case 225: /* eidlist ::= eidlist COMMA nm collate sortorder */

  152892. {

  152893.   yymsp[-4].minor.yy94 = parserAddExprIdListTerm(pParse, yymsp[-4].minor.yy94, &yymsp[-2].minor.yy0, yymsp[-1].minor.yy100, yymsp[0].minor.yy100);

  152894. }

  152895.         break;

  152896.       case 226: /* eidlist ::= nm collate sortorder */

  152897. {

  152898.   yymsp[-2].minor.yy94 = parserAddExprIdListTerm(pParse, 0, &yymsp[-2].minor.yy0, yymsp[-1].minor.yy100, yymsp[0].minor.yy100); /*A-overwrites-Y*/

  152899. }

  152900.         break;

  152901.       case 229: /* cmd ::= DROP INDEX ifexists fullname */

  152902. {sqlite3DropIndex(pParse, yymsp[0].minor.yy407, yymsp[-1].minor.yy100);}

  152903.         break;

  152904.       case 230: /* cmd ::= VACUUM vinto */

  152905. {sqlite3Vacuum(pParse,0,yymsp[0].minor.yy102);}

  152906.         break;

  152907.       case 231: /* cmd ::= VACUUM nm vinto */

  152908. {sqlite3Vacuum(pParse,&yymsp[-1].minor.yy0,yymsp[0].minor.yy102);}

  152909.         break;

  152910.       case 234: /* cmd ::= PRAGMA nm dbnm */

  152911. {sqlite3Pragma(pParse,&yymsp[-1].minor.yy0,&yymsp[0].minor.yy0,0,0);}

  152912.         break;

  152913.       case 235: /* cmd ::= PRAGMA nm dbnm EQ nmnum */

  152914. {sqlite3Pragma(pParse,&yymsp[-3].minor.yy0,&yymsp[-2].minor.yy0,&yymsp[0].minor.yy0,0);}

  152915.         break;

  152916.       case 236: /* cmd ::= PRAGMA nm dbnm LP nmnum RP */

  152917. {sqlite3Pragma(pParse,&yymsp[-4].minor.yy0,&yymsp[-3].minor.yy0,&yymsp[-1].minor.yy0,0);}

  152918.         break;

  152919.       case 237: /* cmd ::= PRAGMA nm dbnm EQ minus_num */

  152920. {sqlite3Pragma(pParse,&yymsp[-3].minor.yy0,&yymsp[-2].minor.yy0,&yymsp[0].minor.yy0,1);}

  152921.         break;

  152922.       case 238: /* cmd ::= PRAGMA nm dbnm LP minus_num RP */

  152923. {sqlite3Pragma(pParse,&yymsp[-4].minor.yy0,&yymsp[-3].minor.yy0,&yymsp[-1].minor.yy0,1);}

  152924.         break;

  152925.       case 241: /* cmd ::= createkw trigger_decl BEGIN trigger_cmd_list END */

  152926. {

  152927.   Token all;

  152928.   all.z = yymsp[-3].minor.yy0.z;

  152929.   all.n = (int)(yymsp[0].minor.yy0.z - yymsp[-3].minor.yy0.z) + yymsp[0].minor.yy0.n;

  152930.   sqlite3FinishTrigger(pParse, yymsp[-1].minor.yy11, &all);

  152931. }

  152932.         break;

  152933.       case 242: /* trigger_decl ::= temp TRIGGER ifnotexists nm dbnm trigger_time trigger_event ON fullname foreach_clause when_clause */

  152934. {

  152935.   sqlite3BeginTrigger(pParse, &yymsp[-7].minor.yy0, &yymsp[-6].minor.yy0, yymsp[-5].minor.yy100, yymsp[-4].minor.yy298.a, yymsp[-4].minor.yy298.b, yymsp[-2].minor.yy407, yymsp[0].minor.yy102, yymsp[-10].minor.yy100, yymsp[-8].minor.yy100);

  152936.   yymsp[-10].minor.yy0 = (yymsp[-6].minor.yy0.n==0?yymsp[-7].minor.yy0:yymsp[-6].minor.yy0); /*A-overwrites-T*/

  152937. }

  152938.         break;

  152939.       case 243: /* trigger_time ::= BEFORE|AFTER */

  152940. { yymsp[0].minor.yy100 = yymsp[0].major; /*A-overwrites-X*/ }

  152941.         break;

  152942.       case 244: /* trigger_time ::= INSTEAD OF */

  152943. { yymsp[-1].minor.yy100 = TK_INSTEAD;}

  152944.         break;

  152945.       case 245: /* trigger_time ::= */

  152946. { yymsp[1].minor.yy100 = TK_BEFORE; }

  152947.         break;

  152948.       case 246: /* trigger_event ::= DELETE|INSERT */

  152949.       case 247: /* trigger_event ::= UPDATE */ yytestcase(yyruleno==247);

  152950. {yymsp[0].minor.yy298.a = yymsp[0].major; /*A-overwrites-X*/ yymsp[0].minor.yy298.b = 0;}

  152951.         break;

  152952.       case 248: /* trigger_event ::= UPDATE OF idlist */

  152953. {yymsp[-2].minor.yy298.a = TK_UPDATE; yymsp[-2].minor.yy298.b = yymsp[0].minor.yy76;}

  152954.         break;

  152955.       case 249: /* when_clause ::= */

  152956.       case 268: /* key_opt ::= */ yytestcase(yyruleno==268);

  152957.       case 316: /* filter_opt ::= */ yytestcase(yyruleno==316);

  152958. { yymsp[1].minor.yy102 = 0; }

  152959.         break;

  152960.       case 250: /* when_clause ::= WHEN expr */

  152961.       case 269: /* key_opt ::= KEY expr */ yytestcase(yyruleno==269);

  152962. { yymsp[-1].minor.yy102 = yymsp[0].minor.yy102; }

  152963.         break;

  152964.       case 251: /* trigger_cmd_list ::= trigger_cmd_list trigger_cmd SEMI */

  152965. {

  152966.   assert( yymsp[-2].minor.yy11!=0 );

  152967.   yymsp[-2].minor.yy11->pLast->pNext = yymsp[-1].minor.yy11;

  152968.   yymsp[-2].minor.yy11->pLast = yymsp[-1].minor.yy11;

  152969. }

  152970.         break;

  152971.       case 252: /* trigger_cmd_list ::= trigger_cmd SEMI */

  152972. { 

  152973.   assert( yymsp[-1].minor.yy11!=0 );

  152974.   yymsp[-1].minor.yy11->pLast = yymsp[-1].minor.yy11;

  152975. }

  152976.         break;

  152977.       case 253: /* trnm ::= nm DOT nm */

  152978. {

  152979.   yymsp[-2].minor.yy0 = yymsp[0].minor.yy0;

  152980.   sqlite3ErrorMsg(pParse, 

  152981.         "qualified table names are not allowed on INSERT, UPDATE, and DELETE "

  152982.         "statements within triggers");

  152983. }

  152984.         break;

  152985.       case 254: /* tridxby ::= INDEXED BY nm */

  152986. {

  152987.   sqlite3ErrorMsg(pParse,

  152988.         "the INDEXED BY clause is not allowed on UPDATE or DELETE statements "

  152989.         "within triggers");

  152990. }

  152991.         break;

  152992.       case 255: /* tridxby ::= NOT INDEXED */

  152993. {

  152994.   sqlite3ErrorMsg(pParse,

  152995.         "the NOT INDEXED clause is not allowed on UPDATE or DELETE statements "

  152996.         "within triggers");

  152997. }

  152998.         break;

  152999.       case 256: /* trigger_cmd ::= UPDATE orconf trnm tridxby SET setlist where_opt scanpt */

  153000. {yylhsminor.yy11 = sqlite3TriggerUpdateStep(pParse, &yymsp[-5].minor.yy0, yymsp[-2].minor.yy94, yymsp[-1].minor.yy102, yymsp[-6].minor.yy100, yymsp[-7].minor.yy0.z, yymsp[0].minor.yy528);}

  153001.   yymsp[-7].minor.yy11 = yylhsminor.yy11;

  153002.         break;

  153003.       case 257: /* trigger_cmd ::= scanpt insert_cmd INTO trnm idlist_opt select upsert scanpt */

  153004. {

  153005.    yylhsminor.yy11 = sqlite3TriggerInsertStep(pParse,&yymsp[-4].minor.yy0,yymsp[-3].minor.yy76,yymsp[-2].minor.yy391,yymsp[-6].minor.yy100,yymsp[-1].minor.yy95,yymsp[-7].minor.yy528,yymsp[0].minor.yy528);/*yylhsminor.yy11-overwrites-yymsp[-6].minor.yy100*/

  153006. }

  153007.   yymsp[-7].minor.yy11 = yylhsminor.yy11;

  153008.         break;

  153009.       case 258: /* trigger_cmd ::= DELETE FROM trnm tridxby where_opt scanpt */

  153010. {yylhsminor.yy11 = sqlite3TriggerDeleteStep(pParse, &yymsp[-3].minor.yy0, yymsp[-1].minor.yy102, yymsp[-5].minor.yy0.z, yymsp[0].minor.yy528);}

  153011.   yymsp[-5].minor.yy11 = yylhsminor.yy11;

  153012.         break;

  153013.       case 259: /* trigger_cmd ::= scanpt select scanpt */

  153014. {yylhsminor.yy11 = sqlite3TriggerSelectStep(pParse->db, yymsp[-1].minor.yy391, yymsp[-2].minor.yy528, yymsp[0].minor.yy528); /*yylhsminor.yy11-overwrites-yymsp[-1].minor.yy391*/}

  153015.   yymsp[-2].minor.yy11 = yylhsminor.yy11;

  153016.         break;

  153017.       case 260: /* expr ::= RAISE LP IGNORE RP */

  153018. {

  153019.   yymsp[-3].minor.yy102 = sqlite3PExpr(pParse, TK_RAISE, 0, 0); 

  153020.   if( yymsp[-3].minor.yy102 ){

  153021.     yymsp[-3].minor.yy102->affinity = OE_Ignore;

  153022.   }

  153023. }

  153024.         break;

  153025.       case 261: /* expr ::= RAISE LP raisetype COMMA nm RP */

  153026. {

  153027.   yymsp[-5].minor.yy102 = sqlite3ExprAlloc(pParse->db, TK_RAISE, &yymsp[-1].minor.yy0, 1); 

  153028.   if( yymsp[-5].minor.yy102 ) {

  153029.     yymsp[-5].minor.yy102->affinity = (char)yymsp[-3].minor.yy100;

  153030.   }

  153031. }

  153032.         break;

  153033.       case 262: /* raisetype ::= ROLLBACK */

  153034. {yymsp[0].minor.yy100 = OE_Rollback;}

  153035.         break;

  153036.       case 264: /* raisetype ::= FAIL */

  153037. {yymsp[0].minor.yy100 = OE_Fail;}

  153038.         break;

  153039.       case 265: /* cmd ::= DROP TRIGGER ifexists fullname */

  153040. {

  153041.   sqlite3DropTrigger(pParse,yymsp[0].minor.yy407,yymsp[-1].minor.yy100);

  153042. }

  153043.         break;

  153044.       case 266: /* cmd ::= ATTACH database_kw_opt expr AS expr key_opt */

  153045. {

  153046.   sqlite3Attach(pParse, yymsp[-3].minor.yy102, yymsp[-1].minor.yy102, yymsp[0].minor.yy102);

  153047. }

  153048.         break;

  153049.       case 267: /* cmd ::= DETACH database_kw_opt expr */

  153050. {

  153051.   sqlite3Detach(pParse, yymsp[0].minor.yy102);

  153052. }

  153053.         break;

  153054.       case 270: /* cmd ::= REINDEX */

  153055. {sqlite3Reindex(pParse, 0, 0);}

  153056.         break;

  153057.       case 271: /* cmd ::= REINDEX nm dbnm */

  153058. {sqlite3Reindex(pParse, &yymsp[-1].minor.yy0, &yymsp[0].minor.yy0);}

  153059.         break;

  153060.       case 272: /* cmd ::= ANALYZE */

  153061. {sqlite3Analyze(pParse, 0, 0);}

  153062.         break;

  153063.       case 273: /* cmd ::= ANALYZE nm dbnm */

  153064. {sqlite3Analyze(pParse, &yymsp[-1].minor.yy0, &yymsp[0].minor.yy0);}

  153065.         break;

  153066.       case 274: /* cmd ::= ALTER TABLE fullname RENAME TO nm */

  153067. {

  153068.   sqlite3AlterRenameTable(pParse,yymsp[-3].minor.yy407,&yymsp[0].minor.yy0);

  153069. }

  153070.         break;

  153071.       case 275: /* cmd ::= ALTER TABLE add_column_fullname ADD kwcolumn_opt columnname carglist */

  153072. {

  153073.   yymsp[-1].minor.yy0.n = (int)(pParse->sLastToken.z-yymsp[-1].minor.yy0.z) + pParse->sLastToken.n;

  153074.   sqlite3AlterFinishAddColumn(pParse, &yymsp[-1].minor.yy0);

  153075. }

  153076.         break;

  153077.       case 276: /* add_column_fullname ::= fullname */

  153078. {

  153079.   disableLookaside(pParse);

  153080.   sqlite3AlterBeginAddColumn(pParse, yymsp[0].minor.yy407);

  153081. }

  153082.         break;

  153083.       case 277: /* cmd ::= ALTER TABLE fullname RENAME kwcolumn_opt nm TO nm */

  153084. {

  153085.   sqlite3AlterRenameColumn(pParse, yymsp[-5].minor.yy407, &yymsp[-2].minor.yy0, &yymsp[0].minor.yy0);

  153086. }

  153087.         break;

  153088.       case 278: /* cmd ::= create_vtab */

  153089. {sqlite3VtabFinishParse(pParse,0);}

  153090.         break;

  153091.       case 279: /* cmd ::= create_vtab LP vtabarglist RP */

  153092. {sqlite3VtabFinishParse(pParse,&yymsp[0].minor.yy0);}

  153093.         break;

  153094.       case 280: /* create_vtab ::= createkw VIRTUAL TABLE ifnotexists nm dbnm USING nm */

  153095. {

  153096.     sqlite3VtabBeginParse(pParse, &yymsp[-3].minor.yy0, &yymsp[-2].minor.yy0, &yymsp[0].minor.yy0, yymsp[-4].minor.yy100);

  153097. }

  153098.         break;

  153099.       case 281: /* vtabarg ::= */

  153100. {sqlite3VtabArgInit(pParse);}

  153101.         break;

  153102.       case 282: /* vtabargtoken ::= ANY */

  153103.       case 283: /* vtabargtoken ::= lp anylist RP */ yytestcase(yyruleno==283);

  153104.       case 284: /* lp ::= LP */ yytestcase(yyruleno==284);

  153105. {sqlite3VtabArgExtend(pParse,&yymsp[0].minor.yy0);}

  153106.         break;

  153107.       case 285: /* with ::= WITH wqlist */

  153108.       case 286: /* with ::= WITH RECURSIVE wqlist */ yytestcase(yyruleno==286);

  153109. { sqlite3WithPush(pParse, yymsp[0].minor.yy243, 1); }

  153110.         break;

  153111.       case 287: /* wqlist ::= nm eidlist_opt AS LP select RP */

  153112. {

  153113.   yymsp[-5].minor.yy243 = sqlite3WithAdd(pParse, 0, &yymsp[-5].minor.yy0, yymsp[-4].minor.yy94, yymsp[-1].minor.yy391); /*A-overwrites-X*/

  153114. }

  153115.         break;

  153116.       case 288: /* wqlist ::= wqlist COMMA nm eidlist_opt AS LP select RP */

  153117. {

  153118.   yymsp[-7].minor.yy243 = sqlite3WithAdd(pParse, yymsp[-7].minor.yy243, &yymsp[-5].minor.yy0, yymsp[-4].minor.yy94, yymsp[-1].minor.yy391);

  153119. }

  153120.         break;

  153121.       case 289: /* windowdefn_list ::= windowdefn */

  153122. { yylhsminor.yy379 = yymsp[0].minor.yy379; }

  153123.   yymsp[0].minor.yy379 = yylhsminor.yy379;

  153124.         break;

  153125.       case 290: /* windowdefn_list ::= windowdefn_list COMMA windowdefn */

  153126. {

  153127.   assert( yymsp[0].minor.yy379!=0 );

  153128.   sqlite3WindowChain(pParse, yymsp[0].minor.yy379, yymsp[-2].minor.yy379);

  153129.   yymsp[0].minor.yy379->pNextWin = yymsp[-2].minor.yy379;

  153130.   yylhsminor.yy379 = yymsp[0].minor.yy379;

  153131. }

  153132.   yymsp[-2].minor.yy379 = yylhsminor.yy379;

  153133.         break;

  153134.       case 291: /* windowdefn ::= nm AS LP window RP */

  153135. {

  153136.   if( ALWAYS(yymsp[-1].minor.yy379) ){

  153137.     yymsp[-1].minor.yy379->zName = sqlite3DbStrNDup(pParse->db, yymsp[-4].minor.yy0.z, yymsp[-4].minor.yy0.n);

  153138.   }

  153139.   yylhsminor.yy379 = yymsp[-1].minor.yy379;

  153140. }

  153141.   yymsp[-4].minor.yy379 = yylhsminor.yy379;

  153142.         break;

  153143.       case 292: /* window ::= PARTITION BY nexprlist orderby_opt frame_opt */

  153144. {

  153145.   yymsp[-4].minor.yy379 = sqlite3WindowAssemble(pParse, yymsp[0].minor.yy379, yymsp[-2].minor.yy94, yymsp[-1].minor.yy94, 0);

  153146. }

  153147.         break;

  153148.       case 293: /* window ::= nm PARTITION BY nexprlist orderby_opt frame_opt */

  153149. {

  153150.   yylhsminor.yy379 = sqlite3WindowAssemble(pParse, yymsp[0].minor.yy379, yymsp[-2].minor.yy94, yymsp[-1].minor.yy94, &yymsp[-5].minor.yy0);

  153151. }

  153152.   yymsp[-5].minor.yy379 = yylhsminor.yy379;

  153153.         break;

  153154.       case 294: /* window ::= ORDER BY sortlist frame_opt */

  153155. {

  153156.   yymsp[-3].minor.yy379 = sqlite3WindowAssemble(pParse, yymsp[0].minor.yy379, 0, yymsp[-1].minor.yy94, 0);

  153157. }

  153158.         break;

  153159.       case 295: /* window ::= nm ORDER BY sortlist frame_opt */

  153160. {

  153161.   yylhsminor.yy379 = sqlite3WindowAssemble(pParse, yymsp[0].minor.yy379, 0, yymsp[-1].minor.yy94, &yymsp[-4].minor.yy0);

  153162. }

  153163.   yymsp[-4].minor.yy379 = yylhsminor.yy379;

  153164.         break;

  153165.       case 296: /* window ::= frame_opt */

  153166. {

  153167.   yylhsminor.yy379 = yymsp[0].minor.yy379;

  153168. }

  153169.   yymsp[0].minor.yy379 = yylhsminor.yy379;

  153170.         break;

  153171.       case 297: /* window ::= nm frame_opt */

  153172. {

  153173.   yylhsminor.yy379 = sqlite3WindowAssemble(pParse, yymsp[0].minor.yy379, 0, 0, &yymsp[-1].minor.yy0);

  153174. }

  153175.   yymsp[-1].minor.yy379 = yylhsminor.yy379;

  153176.         break;

  153177.       case 298: /* frame_opt ::= */

  153178. { 

  153179.   yymsp[1].minor.yy379 = sqlite3WindowAlloc(pParse, 0, TK_UNBOUNDED, 0, TK_CURRENT, 0, 0);

  153180. }

  153181.         break;

  153182.       case 299: /* frame_opt ::= range_or_rows frame_bound_s frame_exclude_opt */

  153183. { 

  153184.   yylhsminor.yy379 = sqlite3WindowAlloc(pParse, yymsp[-2].minor.yy100, yymsp[-1].minor.yy389.eType, yymsp[-1].minor.yy389.pExpr, TK_CURRENT, 0, yymsp[0].minor.yy218);

  153185. }

  153186.   yymsp[-2].minor.yy379 = yylhsminor.yy379;

  153187.         break;

  153188.       case 300: /* frame_opt ::= range_or_rows BETWEEN frame_bound_s AND frame_bound_e frame_exclude_opt */

  153189. { 

  153190.   yylhsminor.yy379 = sqlite3WindowAlloc(pParse, yymsp[-5].minor.yy100, yymsp[-3].minor.yy389.eType, yymsp[-3].minor.yy389.pExpr, yymsp[-1].minor.yy389.eType, yymsp[-1].minor.yy389.pExpr, yymsp[0].minor.yy218);

  153191. }

  153192.   yymsp[-5].minor.yy379 = yylhsminor.yy379;

  153193.         break;

  153194.       case 302: /* frame_bound_s ::= frame_bound */

  153195.       case 304: /* frame_bound_e ::= frame_bound */ yytestcase(yyruleno==304);

  153196. {yylhsminor.yy389 = yymsp[0].minor.yy389;}

  153197.   yymsp[0].minor.yy389 = yylhsminor.yy389;

  153198.         break;

  153199.       case 303: /* frame_bound_s ::= UNBOUNDED PRECEDING */

  153200.       case 305: /* frame_bound_e ::= UNBOUNDED FOLLOWING */ yytestcase(yyruleno==305);

  153201.       case 307: /* frame_bound ::= CURRENT ROW */ yytestcase(yyruleno==307);

  153202. {yylhsminor.yy389.eType = yymsp[-1].major; yylhsminor.yy389.pExpr = 0;}

  153203.   yymsp[-1].minor.yy389 = yylhsminor.yy389;

  153204.         break;

  153205.       case 306: /* frame_bound ::= expr PRECEDING|FOLLOWING */

  153206. {yylhsminor.yy389.eType = yymsp[0].major; yylhsminor.yy389.pExpr = yymsp[-1].minor.yy102;}

  153207.   yymsp[-1].minor.yy389 = yylhsminor.yy389;

  153208.         break;

  153209.       case 308: /* frame_exclude_opt ::= */

  153210. {yymsp[1].minor.yy218 = 0;}

  153211.         break;

  153212.       case 309: /* frame_exclude_opt ::= EXCLUDE frame_exclude */

  153213. {yymsp[-1].minor.yy218 = yymsp[0].minor.yy218;}

  153214.         break;

  153215.       case 310: /* frame_exclude ::= NO OTHERS */

  153216.       case 311: /* frame_exclude ::= CURRENT ROW */ yytestcase(yyruleno==311);

  153217. {yymsp[-1].minor.yy218 = yymsp[-1].major; /*A-overwrites-X*/}

  153218.         break;

  153219.       case 312: /* frame_exclude ::= GROUP|TIES */

  153220. {yymsp[0].minor.yy218 = yymsp[0].major; /*A-overwrites-X*/}

  153221.         break;

  153222.       case 313: /* window_clause ::= WINDOW windowdefn_list */

  153223. { yymsp[-1].minor.yy379 = yymsp[0].minor.yy379; }

  153224.         break;

  153225.       case 314: /* over_clause ::= filter_opt OVER LP window RP */

  153226. {

  153227.   yylhsminor.yy379 = yymsp[-1].minor.yy379;

  153228.   assert( yylhsminor.yy379!=0 );

  153229.   yylhsminor.yy379->pFilter = yymsp[-4].minor.yy102;

  153230. }

  153231.   yymsp[-4].minor.yy379 = yylhsminor.yy379;

  153232.         break;

  153233.       case 315: /* over_clause ::= filter_opt OVER nm */

  153234. {

  153235.   yylhsminor.yy379 = (Window*)sqlite3DbMallocZero(pParse->db, sizeof(Window));

  153236.   if( yylhsminor.yy379 ){

  153237.     yylhsminor.yy379->zName = sqlite3DbStrNDup(pParse->db, yymsp[0].minor.yy0.z, yymsp[0].minor.yy0.n);

  153238.     yylhsminor.yy379->pFilter = yymsp[-2].minor.yy102;

  153239.   }else{

  153240.     sqlite3ExprDelete(pParse->db, yymsp[-2].minor.yy102);

  153241.   }

  153242. }

  153243.   yymsp[-2].minor.yy379 = yylhsminor.yy379;

  153244.         break;

  153245.       case 317: /* filter_opt ::= FILTER LP WHERE expr RP */

  153246. { yymsp[-4].minor.yy102 = yymsp[-1].minor.yy102; }

  153247.         break;

  153248.       default:

  153249.       /* (318) input ::= cmdlist */ yytestcase(yyruleno==318);

  153250.       /* (319) cmdlist ::= cmdlist ecmd */ yytestcase(yyruleno==319);

  153251.       /* (320) cmdlist ::= ecmd (OPTIMIZED OUT) */ assert(yyruleno!=320);

  153252.       /* (321) ecmd ::= SEMI */ yytestcase(yyruleno==321);

  153253.       /* (322) ecmd ::= cmdx SEMI */ yytestcase(yyruleno==322);

  153254.       /* (323) ecmd ::= explain cmdx */ yytestcase(yyruleno==323);

  153255.       /* (324) trans_opt ::= */ yytestcase(yyruleno==324);

  153256.       /* (325) trans_opt ::= TRANSACTION */ yytestcase(yyruleno==325);

  153257.       /* (326) trans_opt ::= TRANSACTION nm */ yytestcase(yyruleno==326);

  153258.       /* (327) savepoint_opt ::= SAVEPOINT */ yytestcase(yyruleno==327);

  153259.       /* (328) savepoint_opt ::= */ yytestcase(yyruleno==328);

  153260.       /* (329) cmd ::= create_table create_table_args */ yytestcase(yyruleno==329);

  153261.       /* (330) columnlist ::= columnlist COMMA columnname carglist */ yytestcase(yyruleno==330);

  153262.       /* (331) columnlist ::= columnname carglist */ yytestcase(yyruleno==331);

  153263.       /* (332) nm ::= ID|INDEXED */ yytestcase(yyruleno==332);

  153264.       /* (333) nm ::= STRING */ yytestcase(yyruleno==333);

  153265.       /* (334) nm ::= JOIN_KW */ yytestcase(yyruleno==334);

  153266.       /* (335) typetoken ::= typename */ yytestcase(yyruleno==335);

  153267.       /* (336) typename ::= ID|STRING */ yytestcase(yyruleno==336);

  153268.       /* (337) signed ::= plus_num (OPTIMIZED OUT) */ assert(yyruleno!=337);

  153269.       /* (338) signed ::= minus_num (OPTIMIZED OUT) */ assert(yyruleno!=338);

  153270.       /* (339) carglist ::= carglist ccons */ yytestcase(yyruleno==339);

  153271.       /* (340) carglist ::= */ yytestcase(yyruleno==340);

  153272.       /* (341) ccons ::= NULL onconf */ yytestcase(yyruleno==341);

  153273.       /* (342) conslist_opt ::= COMMA conslist */ yytestcase(yyruleno==342);

  153274.       /* (343) conslist ::= conslist tconscomma tcons */ yytestcase(yyruleno==343);

  153275.       /* (344) conslist ::= tcons (OPTIMIZED OUT) */ assert(yyruleno!=344);

  153276.       /* (345) tconscomma ::= */ yytestcase(yyruleno==345);

  153277.       /* (346) defer_subclause_opt ::= defer_subclause (OPTIMIZED OUT) */ assert(yyruleno!=346);

  153278.       /* (347) resolvetype ::= raisetype (OPTIMIZED OUT) */ assert(yyruleno!=347);

  153279.       /* (348) selectnowith ::= oneselect (OPTIMIZED OUT) */ assert(yyruleno!=348);

  153280.       /* (349) oneselect ::= values */ yytestcase(yyruleno==349);

  153281.       /* (350) sclp ::= selcollist COMMA */ yytestcase(yyruleno==350);

  153282.       /* (351) as ::= ID|STRING */ yytestcase(yyruleno==351);

  153283.       /* (352) expr ::= term (OPTIMIZED OUT) */ assert(yyruleno!=352);

  153284.       /* (353) likeop ::= LIKE_KW|MATCH */ yytestcase(yyruleno==353);

  153285.       /* (354) exprlist ::= nexprlist */ yytestcase(yyruleno==354);

  153286.       /* (355) nmnum ::= plus_num (OPTIMIZED OUT) */ assert(yyruleno!=355);

  153287.       /* (356) nmnum ::= nm (OPTIMIZED OUT) */ assert(yyruleno!=356);

  153288.       /* (357) nmnum ::= ON */ yytestcase(yyruleno==357);

  153289.       /* (358) nmnum ::= DELETE */ yytestcase(yyruleno==358);

  153290.       /* (359) nmnum ::= DEFAULT */ yytestcase(yyruleno==359);

  153291.       /* (360) plus_num ::= INTEGER|FLOAT */ yytestcase(yyruleno==360);

  153292.       /* (361) foreach_clause ::= */ yytestcase(yyruleno==361);

  153293.       /* (362) foreach_clause ::= FOR EACH ROW */ yytestcase(yyruleno==362);

  153294.       /* (363) trnm ::= nm */ yytestcase(yyruleno==363);

  153295.       /* (364) tridxby ::= */ yytestcase(yyruleno==364);

  153296.       /* (365) database_kw_opt ::= DATABASE */ yytestcase(yyruleno==365);

  153297.       /* (366) database_kw_opt ::= */ yytestcase(yyruleno==366);

  153298.       /* (367) kwcolumn_opt ::= */ yytestcase(yyruleno==367);

  153299.       /* (368) kwcolumn_opt ::= COLUMNKW */ yytestcase(yyruleno==368);

  153300.       /* (369) vtabarglist ::= vtabarg */ yytestcase(yyruleno==369);

  153301.       /* (370) vtabarglist ::= vtabarglist COMMA vtabarg */ yytestcase(yyruleno==370);

  153302.       /* (371) vtabarg ::= vtabarg vtabargtoken */ yytestcase(yyruleno==371);

  153303.       /* (372) anylist ::= */ yytestcase(yyruleno==372);

  153304.       /* (373) anylist ::= anylist LP anylist RP */ yytestcase(yyruleno==373);

  153305.       /* (374) anylist ::= anylist ANY */ yytestcase(yyruleno==374);

  153306.       /* (375) with ::= */ yytestcase(yyruleno==375);

  153307.         break;

  153308. /********** End reduce actions ************************************************/

  153309.   };

  153310.   assert( yyruleno<sizeof(yyRuleInfoLhs)/sizeof(yyRuleInfoLhs[0]) );

  153311.   yygoto = yyRuleInfoLhs[yyruleno];

  153312.   yysize = yyRuleInfoNRhs[yyruleno];

  153313.   yyact = yy_find_reduce_action(yymsp[yysize].stateno,(YYCODETYPE)yygoto);

  153314. 

  153315.   /* There are no SHIFTREDUCE actions on nonterminals because the table

  153316.   ** generator has simplified them to pure REDUCE actions. */

  153317.   assert( !(yyact>YY_MAX_SHIFT && yyact<=YY_MAX_SHIFTREDUCE) );

  153318. 

  153319.   /* It is not possible for a REDUCE to be followed by an error */

  153320.   assert( yyact!=YY_ERROR_ACTION );

  153321. 

  153322.   yymsp += yysize+1;

  153323.   yypParser->yytos = yymsp;

  153324.   yymsp->stateno = (YYACTIONTYPE)yyact;

  153325.   yymsp->major = (YYCODETYPE)yygoto;

  153326.   yyTraceShift(yypParser, yyact, "... then shift");

  153327.   return yyact;

  153328. }

  153329. 

  153330. /*

  153331. ** The following code executes when the parse fails

  153332. */

  153333. #ifndef YYNOERRORRECOVERY

  153334. static void yy_parse_failed(

  153335.   yyParser *yypParser           /* The parser */

  153336. ){

  153337.   sqlite3ParserARG_FETCH

  153338.   sqlite3ParserCTX_FETCH

  153339. #ifndef NDEBUG

  153340.   if( yyTraceFILE ){

  153341.     fprintf(yyTraceFILE,"%sFail!\n",yyTracePrompt);

  153342.   }

  153343. #endif

  153344.   while( yypParser->yytos>yypParser->yystack ) yy_pop_parser_stack(yypParser);

  153345.   /* Here code is inserted which will be executed whenever the

  153346.   ** parser fails */

  153347. /************ Begin %parse_failure code ***************************************/

  153348. /************ End %parse_failure code *****************************************/

  153349.   sqlite3ParserARG_STORE /* Suppress warning about unused %extra_argument variable */

  153350.   sqlite3ParserCTX_STORE

  153351. }

  153352. #endif /* YYNOERRORRECOVERY */

  153353. 

  153354. /*

  153355. ** The following code executes when a syntax error first occurs.

  153356. */

  153357. static void yy_syntax_error(

  153358.   yyParser *yypParser,           /* The parser */

  153359.   int yymajor,                   /* The major type of the error token */

  153360.   sqlite3ParserTOKENTYPE yyminor         /* The minor type of the error token */

  153361. ){

  153362.   sqlite3ParserARG_FETCH

  153363.   sqlite3ParserCTX_FETCH

  153364. #define TOKEN yyminor

  153365. /************ Begin %syntax_error code ****************************************/

  153366. 

  153367.   UNUSED_PARAMETER(yymajor);  /* Silence some compiler warnings */

  153368.   if( TOKEN.z[0] ){

  153369.     sqlite3ErrorMsg(pParse, "near \"%T\": syntax error", &TOKEN);

  153370.   }else{

  153371.     sqlite3ErrorMsg(pParse, "incomplete input");

  153372.   }

  153373. /************ End %syntax_error code ******************************************/

  153374.   sqlite3ParserARG_STORE /* Suppress warning about unused %extra_argument variable */

  153375.   sqlite3ParserCTX_STORE

  153376. }

  153377. 

  153378. /*

  153379. ** The following is executed when the parser accepts

  153380. */

  153381. static void yy_accept(

  153382.   yyParser *yypParser           /* The parser */

  153383. ){

  153384.   sqlite3ParserARG_FETCH

  153385.   sqlite3ParserCTX_FETCH

  153386. #ifndef NDEBUG

  153387.   if( yyTraceFILE ){

  153388.     fprintf(yyTraceFILE,"%sAccept!\n",yyTracePrompt);

  153389.   }

  153390. #endif

  153391. #ifndef YYNOERRORRECOVERY

  153392.   yypParser->yyerrcnt = -1;

  153393. #endif

  153394.   assert( yypParser->yytos==yypParser->yystack );

  153395.   /* Here code is inserted which will be executed whenever the

  153396.   ** parser accepts */

  153397. /*********** Begin %parse_accept code *****************************************/

  153398. /*********** End %parse_accept code *******************************************/

  153399.   sqlite3ParserARG_STORE /* Suppress warning about unused %extra_argument variable */

  153400.   sqlite3ParserCTX_STORE

  153401. }

  153402. 

  153403. /* The main parser program.

  153404. ** The first argument is a pointer to a structure obtained from

  153405. ** "sqlite3ParserAlloc" which describes the current state of the parser.

  153406. ** The second argument is the major token number.  The third is

  153407. ** the minor token.  The fourth optional argument is whatever the

  153408. ** user wants (and specified in the grammar) and is available for

  153409. ** use by the action routines.

  153410. **

  153411. ** Inputs:

  153412. ** <ul>

  153413. ** <li> A pointer to the parser (an opaque structure.)

  153414. ** <li> The major token number.

  153415. ** <li> The minor token number.

  153416. ** <li> An option argument of a grammar-specified type.

  153417. ** </ul>

  153418. **

  153419. ** Outputs:

  153420. ** None.

  153421. */

  153422. SQLITE_PRIVATE void sqlite3Parser(

  153423.   void *yyp,                   /* The parser */

  153424.   int yymajor,                 /* The major token code number */

  153425.   sqlite3ParserTOKENTYPE yyminor       /* The value for the token */

  153426.   sqlite3ParserARG_PDECL               /* Optional %extra_argument parameter */

  153427. ){

  153428.   YYMINORTYPE yyminorunion;

  153429.   YYACTIONTYPE yyact;   /* The parser action. */

  153430. #if !defined(YYERRORSYMBOL) && !defined(YYNOERRORRECOVERY)

  153431.   int yyendofinput;     /* True if we are at the end of input */

  153432. #endif

  153433. #ifdef YYERRORSYMBOL

  153434.   int yyerrorhit = 0;   /* True if yymajor has invoked an error */

  153435. #endif

  153436.   yyParser *yypParser = (yyParser*)yyp;  /* The parser */

  153437.   sqlite3ParserCTX_FETCH

  153438.   sqlite3ParserARG_STORE

  153439. 

  153440.   assert( yypParser->yytos!=0 );

  153441. #if !defined(YYERRORSYMBOL) && !defined(YYNOERRORRECOVERY)

  153442.   yyendofinput = (yymajor==0);

  153443. #endif

  153444. 

  153445.   yyact = yypParser->yytos->stateno;

  153446. #ifndef NDEBUG

  153447.   if( yyTraceFILE ){

  153448.     if( yyact < YY_MIN_REDUCE ){

  153449.       fprintf(yyTraceFILE,"%sInput '%s' in state %d\n",

  153450.               yyTracePrompt,yyTokenName[yymajor],yyact);

  153451.     }else{

  153452.       fprintf(yyTraceFILE,"%sInput '%s' with pending reduce %d\n",

  153453.               yyTracePrompt,yyTokenName[yymajor],yyact-YY_MIN_REDUCE);

  153454.     }

  153455.   }

  153456. #endif

  153457. 

  153458.   do{

  153459.     assert( yyact==yypParser->yytos->stateno );

  153460.     yyact = yy_find_shift_action((YYCODETYPE)yymajor,yyact);

  153461.     if( yyact >= YY_MIN_REDUCE ){

  153462.       yyact = yy_reduce(yypParser,yyact-YY_MIN_REDUCE,yymajor,

  153463.                         yyminor sqlite3ParserCTX_PARAM);

  153464.     }else if( yyact <= YY_MAX_SHIFTREDUCE ){

  153465.       yy_shift(yypParser,yyact,(YYCODETYPE)yymajor,yyminor);

  153466. #ifndef YYNOERRORRECOVERY

  153467.       yypParser->yyerrcnt--;

  153468. #endif

  153469.       break;

  153470.     }else if( yyact==YY_ACCEPT_ACTION ){

  153471.       yypParser->yytos--;

  153472.       yy_accept(yypParser);

  153473.       return;

  153474.     }else{

  153475.       assert( yyact == YY_ERROR_ACTION );

  153476.       yyminorunion.yy0 = yyminor;

  153477. #ifdef YYERRORSYMBOL

  153478.       int yymx;

  153479. #endif

  153480. #ifndef NDEBUG

  153481.       if( yyTraceFILE ){

  153482.         fprintf(yyTraceFILE,"%sSyntax Error!\n",yyTracePrompt);

  153483.       }

  153484. #endif

  153485. #ifdef YYERRORSYMBOL

  153486.       /* A syntax error has occurred.

  153487.       ** The response to an error depends upon whether or not the

  153488.       ** grammar defines an error token "ERROR".  

  153489.       **

  153490.       ** This is what we do if the grammar does define ERROR:

  153491.       **

  153492.       **  * Call the %syntax_error function.

  153493.       **

  153494.       **  * Begin popping the stack until we enter a state where

  153495.       **    it is legal to shift the error symbol, then shift

  153496.       **    the error symbol.

  153497.       **

  153498.       **  * Set the error count to three.

  153499.       **

  153500.       **  * Begin accepting and shifting new tokens.  No new error

  153501.       **    processing will occur until three tokens have been

  153502.       **    shifted successfully.

  153503.       **

  153504.       */

  153505.       if( yypParser->yyerrcnt<0 ){

  153506.         yy_syntax_error(yypParser,yymajor,yyminor);

  153507.       }

  153508.       yymx = yypParser->yytos->major;

  153509.       if( yymx==YYERRORSYMBOL || yyerrorhit ){

  153510. #ifndef NDEBUG

  153511.         if( yyTraceFILE ){

  153512.           fprintf(yyTraceFILE,"%sDiscard input token %s\n",

  153513.              yyTracePrompt,yyTokenName[yymajor]);

  153514.         }

  153515. #endif

  153516.         yy_destructor(yypParser, (YYCODETYPE)yymajor, &yyminorunion);

  153517.         yymajor = YYNOCODE;

  153518.       }else{

  153519.         while( yypParser->yytos >= yypParser->yystack

  153520.             && (yyact = yy_find_reduce_action(

  153521.                         yypParser->yytos->stateno,

  153522.                         YYERRORSYMBOL)) > YY_MAX_SHIFTREDUCE

  153523.         ){

  153524.           yy_pop_parser_stack(yypParser);

  153525.         }

  153526.         if( yypParser->yytos < yypParser->yystack || yymajor==0 ){

  153527.           yy_destructor(yypParser,(YYCODETYPE)yymajor,&yyminorunion);

  153528.           yy_parse_failed(yypParser);

  153529. #ifndef YYNOERRORRECOVERY

  153530.           yypParser->yyerrcnt = -1;

  153531. #endif

  153532.           yymajor = YYNOCODE;

  153533.         }else if( yymx!=YYERRORSYMBOL ){

  153534.           yy_shift(yypParser,yyact,YYERRORSYMBOL,yyminor);

  153535.         }

  153536.       }

  153537.       yypParser->yyerrcnt = 3;

  153538.       yyerrorhit = 1;

  153539.       if( yymajor==YYNOCODE ) break;

  153540.       yyact = yypParser->yytos->stateno;

  153541. #elif defined(YYNOERRORRECOVERY)

  153542.       /* If the YYNOERRORRECOVERY macro is defined, then do not attempt to

  153543.       ** do any kind of error recovery.  Instead, simply invoke the syntax

  153544.       ** error routine and continue going as if nothing had happened.

  153545.       **

  153546.       ** Applications can set this macro (for example inside %include) if

  153547.       ** they intend to abandon the parse upon the first syntax error seen.

  153548.       */

  153549.       yy_syntax_error(yypParser,yymajor, yyminor);

  153550.       yy_destructor(yypParser,(YYCODETYPE)yymajor,&yyminorunion);

  153551.       break;

  153552. #else  /* YYERRORSYMBOL is not defined */

  153553.       /* This is what we do if the grammar does not define ERROR:

  153554.       **

  153555.       **  * Report an error message, and throw away the input token.

  153556.       **

  153557.       **  * If the input token is $, then fail the parse.

  153558.       **

  153559.       ** As before, subsequent error messages are suppressed until

  153560.       ** three input tokens have been successfully shifted.

  153561.       */

  153562.       if( yypParser->yyerrcnt<=0 ){

  153563.         yy_syntax_error(yypParser,yymajor, yyminor);

  153564.       }

  153565.       yypParser->yyerrcnt = 3;

  153566.       yy_destructor(yypParser,(YYCODETYPE)yymajor,&yyminorunion);

  153567.       if( yyendofinput ){

  153568.         yy_parse_failed(yypParser);

  153569. #ifndef YYNOERRORRECOVERY

  153570.         yypParser->yyerrcnt = -1;

  153571. #endif

  153572.       }

  153573.       break;

  153574. #endif

  153575.     }

  153576.   }while( yypParser->yytos>yypParser->yystack );

  153577. #ifndef NDEBUG

  153578.   if( yyTraceFILE ){

  153579.     yyStackEntry *i;

  153580.     char cDiv = '[';

  153581.     fprintf(yyTraceFILE,"%sReturn. Stack=",yyTracePrompt);

  153582.     for(i=&yypParser->yystack[1]; i<=yypParser->yytos; i++){

  153583.       fprintf(yyTraceFILE,"%c%s", cDiv, yyTokenName[i->major]);

  153584.       cDiv = ' ';

  153585.     }

  153586.     fprintf(yyTraceFILE,"]\n");

  153587.   }

  153588. #endif

  153589.   return;

  153590. }

  153591. 

  153592. /*

  153593. ** Return the fallback token corresponding to canonical token iToken, or

  153594. ** 0 if iToken has no fallback.

  153595. */

  153596. SQLITE_PRIVATE int sqlite3ParserFallback(int iToken){

  153597. #ifdef YYFALLBACK

  153598.   if( iToken<(int)(sizeof(yyFallback)/sizeof(yyFallback[0])) ){

  153599.     return yyFallback[iToken];

  153600.   }

  153601. #else

  153602.   (void)iToken;

  153603. #endif

  153604.   return 0;

  153605. }

  153606. 

  153607. /************** End of parse.c ***********************************************/

  153608. /************** Begin file tokenize.c ****************************************/

  153609. /*

  153610. ** 2001 September 15

  153611. **

  153612. ** The author disclaims copyright to this source code.  In place of

  153613. ** a legal notice, here is a blessing:

  153614. **

  153615. **    May you do good and not evil.

  153616. **    May you find forgiveness for yourself and forgive others.

  153617. **    May you share freely, never taking more than you give.

  153618. **

  153619. *************************************************************************

  153620. ** An tokenizer for SQL

  153621. **

  153622. ** This file contains C code that splits an SQL input string up into

  153623. ** individual tokens and sends those tokens one-by-one over to the

  153624. ** parser for analysis.

  153625. */

  153626. /* #include "sqliteInt.h" */

  153627. /* #include <stdlib.h> */

  153628. 

  153629. /* Character classes for tokenizing

  153630. **

  153631. ** In the sqlite3GetToken() function, a switch() on aiClass[c] is implemented

  153632. ** using a lookup table, whereas a switch() directly on c uses a binary search.

  153633. ** The lookup table is much faster.  To maximize speed, and to ensure that

  153634. ** a lookup table is used, all of the classes need to be small integers and

  153635. ** all of them need to be used within the switch.

  153636. */

  153637. #define CC_X          0    /* The letter 'x', or start of BLOB literal */

  153638. #define CC_KYWD       1    /* Alphabetics or '_'.  Usable in a keyword */

  153639. #define CC_ID         2    /* unicode characters usable in IDs */

  153640. #define CC_DIGIT      3    /* Digits */

  153641. #define CC_DOLLAR     4    /* '$' */

  153642. #define CC_VARALPHA   5    /* '@', '#', ':'.  Alphabetic SQL variables */

  153643. #define CC_VARNUM     6    /* '?'.  Numeric SQL variables */

  153644. #define CC_SPACE      7    /* Space characters */

  153645. #define CC_QUOTE      8    /* '"', '\'', or '`'.  String literals, quoted ids */

  153646. #define CC_QUOTE2     9    /* '['.   [...] style quoted ids */

  153647. #define CC_PIPE      10    /* '|'.   Bitwise OR or concatenate */

  153648. #define CC_MINUS     11    /* '-'.  Minus or SQL-style comment */

  153649. #define CC_LT        12    /* '<'.  Part of < or <= or <> */

  153650. #define CC_GT        13    /* '>'.  Part of > or >= */

  153651. #define CC_EQ        14    /* '='.  Part of = or == */

  153652. #define CC_BANG      15    /* '!'.  Part of != */

  153653. #define CC_SLASH     16    /* '/'.  / or c-style comment */

  153654. #define CC_LP        17    /* '(' */

  153655. #define CC_RP        18    /* ')' */

  153656. #define CC_SEMI      19    /* ';' */

  153657. #define CC_PLUS      20    /* '+' */

  153658. #define CC_STAR      21    /* '*' */

  153659. #define CC_PERCENT   22    /* '%' */

  153660. #define CC_COMMA     23    /* ',' */

  153661. #define CC_AND       24    /* '&' */

  153662. #define CC_TILDA     25    /* '~' */

  153663. #define CC_DOT       26    /* '.' */

  153664. #define CC_ILLEGAL   27    /* Illegal character */

  153665. #define CC_NUL       28    /* 0x00 */

  153666. 

  153667. static const unsigned char aiClass[] = {

  153668. #ifdef SQLITE_ASCII

  153669. /*         x0  x1  x2  x3  x4  x5  x6  x7  x8  x9  xa  xb  xc  xd  xe  xf */

  153670. /* 0x */   28, 27, 27, 27, 27, 27, 27, 27, 27,  7,  7, 27,  7,  7, 27, 27,

  153671. /* 1x */   27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27,

  153672. /* 2x */    7, 15,  8,  5,  4, 22, 24,  8, 17, 18, 21, 20, 23, 11, 26, 16,

  153673. /* 3x */    3,  3,  3,  3,  3,  3,  3,  3,  3,  3,  5, 19, 12, 14, 13,  6,

  153674. /* 4x */    5,  1,  1,  1,  1,  1,  1,  1,  1,  1,  1,  1,  1,  1,  1,  1,

  153675. /* 5x */    1,  1,  1,  1,  1,  1,  1,  1,  0,  1,  1,  9, 27, 27, 27,  1,

  153676. /* 6x */    8,  1,  1,  1,  1,  1,  1,  1,  1,  1,  1,  1,  1,  1,  1,  1,

  153677. /* 7x */    1,  1,  1,  1,  1,  1,  1,  1,  0,  1,  1, 27, 10, 27, 25, 27,

  153678. /* 8x */    2,  2,  2,  2,  2,  2,  2,  2,  2,  2,  2,  2,  2,  2,  2,  2,

  153679. /* 9x */    2,  2,  2,  2,  2,  2,  2,  2,  2,  2,  2,  2,  2,  2,  2,  2,

  153680. /* Ax */    2,  2,  2,  2,  2,  2,  2,  2,  2,  2,  2,  2,  2,  2,  2,  2,

  153681. /* Bx */    2,  2,  2,  2,  2,  2,  2,  2,  2,  2,  2,  2,  2,  2,  2,  2,

  153682. /* Cx */    2,  2,  2,  2,  2,  2,  2,  2,  2,  2,  2,  2,  2,  2,  2,  2,

  153683. /* Dx */    2,  2,  2,  2,  2,  2,  2,  2,  2,  2,  2,  2,  2,  2,  2,  2,

  153684. /* Ex */    2,  2,  2,  2,  2,  2,  2,  2,  2,  2,  2,  2,  2,  2,  2,  2,

  153685. /* Fx */    2,  2,  2,  2,  2,  2,  2,  2,  2,  2,  2,  2,  2,  2,  2,  2

  153686. #endif

  153687. #ifdef SQLITE_EBCDIC

  153688. /*         x0  x1  x2  x3  x4  x5  x6  x7  x8  x9  xa  xb  xc  xd  xe  xf */

  153689. /* 0x */   27, 27, 27, 27, 27,  7, 27, 27, 27, 27, 27, 27,  7,  7, 27, 27,

  153690. /* 1x */   27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27,

  153691. /* 2x */   27, 27, 27, 27, 27,  7, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27,

  153692. /* 3x */   27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27,

  153693. /* 4x */    7, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 26, 12, 17, 20, 10,

  153694. /* 5x */   24, 27, 27, 27, 27, 27, 27, 27, 27, 27, 15,  4, 21, 18, 19, 27,

  153695. /* 6x */   11, 16, 27, 27, 27, 27, 27, 27, 27, 27, 27, 23, 22,  1, 13,  6,

  153696. /* 7x */   27, 27, 27, 27, 27, 27, 27, 27, 27,  8,  5,  5,  5,  8, 14,  8,

  153697. /* 8x */   27,  1,  1,  1,  1,  1,  1,  1,  1,  1, 27, 27, 27, 27, 27, 27,

  153698. /* 9x */   27,  1,  1,  1,  1,  1,  1,  1,  1,  1, 27, 27, 27, 27, 27, 27,

  153699. /* Ax */   27, 25,  1,  1,  1,  1,  1,  0,  1,  1, 27, 27, 27, 27, 27, 27,

  153700. /* Bx */   27, 27, 27, 27, 27, 27, 27, 27, 27, 27,  9, 27, 27, 27, 27, 27,

  153701. /* Cx */   27,  1,  1,  1,  1,  1,  1,  1,  1,  1, 27, 27, 27, 27, 27, 27,

  153702. /* Dx */   27,  1,  1,  1,  1,  1,  1,  1,  1,  1, 27, 27, 27, 27, 27, 27,

  153703. /* Ex */   27, 27,  1,  1,  1,  1,  1,  0,  1,  1, 27, 27, 27, 27, 27, 27,

  153704. /* Fx */    3,  3,  3,  3,  3,  3,  3,  3,  3,  3, 27, 27, 27, 27, 27, 27,

  153705. #endif

  153706. };

  153707. 

  153708. /*

  153709. ** The charMap() macro maps alphabetic characters (only) into their

  153710. ** lower-case ASCII equivalent.  On ASCII machines, this is just

  153711. ** an upper-to-lower case map.  On EBCDIC machines we also need

  153712. ** to adjust the encoding.  The mapping is only valid for alphabetics

  153713. ** which are the only characters for which this feature is used. 

  153714. **

  153715. ** Used by keywordhash.h

  153716. */

  153717. #ifdef SQLITE_ASCII

  153718. # define charMap(X) sqlite3UpperToLower[(unsigned char)X]

  153719. #endif

  153720. #ifdef SQLITE_EBCDIC

  153721. # define charMap(X) ebcdicToAscii[(unsigned char)X]

  153722. const unsigned char ebcdicToAscii[] = {

  153723. /* 0   1   2   3   4   5   6   7   8   9   A   B   C   D   E   F */

  153724.    0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  /* 0x */

  153725.    0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  /* 1x */

  153726.    0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  /* 2x */

  153727.    0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  /* 3x */

  153728.    0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  /* 4x */

  153729.    0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  /* 5x */

  153730.    0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0, 95,  0,  0,  /* 6x */

  153731.    0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  /* 7x */

  153732.    0, 97, 98, 99,100,101,102,103,104,105,  0,  0,  0,  0,  0,  0,  /* 8x */

  153733.    0,106,107,108,109,110,111,112,113,114,  0,  0,  0,  0,  0,  0,  /* 9x */

  153734.    0,  0,115,116,117,118,119,120,121,122,  0,  0,  0,  0,  0,  0,  /* Ax */

  153735.    0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  /* Bx */

  153736.    0, 97, 98, 99,100,101,102,103,104,105,  0,  0,  0,  0,  0,  0,  /* Cx */

  153737.    0,106,107,108,109,110,111,112,113,114,  0,  0,  0,  0,  0,  0,  /* Dx */

  153738.    0,  0,115,116,117,118,119,120,121,122,  0,  0,  0,  0,  0,  0,  /* Ex */

  153739.    0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  /* Fx */

  153740. };

  153741. #endif

  153742. 

  153743. /*

  153744. ** The sqlite3KeywordCode function looks up an identifier to determine if

  153745. ** it is a keyword.  If it is a keyword, the token code of that keyword is 

  153746. ** returned.  If the input is not a keyword, TK_ID is returned.

  153747. **

  153748. ** The implementation of this routine was generated by a program,

  153749. ** mkkeywordhash.c, located in the tool subdirectory of the distribution.

  153750. ** The output of the mkkeywordhash.c program is written into a file

  153751. ** named keywordhash.h and then included into this source file by

  153752. ** the #include below.

  153753. */

  153754. /************** Include keywordhash.h in the middle of tokenize.c ************/

  153755. /************** Begin file keywordhash.h *************************************/

  153756. /***** This file contains automatically generated code ******

  153757. **

  153758. ** The code in this file has been automatically generated by

  153759. **

  153760. **   sqlite/tool/mkkeywordhash.c

  153761. **

  153762. ** The code in this file implements a function that determines whether

  153763. ** or not a given identifier is really an SQL keyword.  The same thing

  153764. ** might be implemented more directly using a hand-written hash table.

  153765. ** But by using this automatically generated code, the size of the code

  153766. ** is substantially reduced.  This is important for embedded applications

  153767. ** on platforms with limited memory.

  153768. */

  153769. /* Hash score: 214 */

  153770. /* zKWText[] encodes 950 bytes of keyword text in 629 bytes */

  153771. /*   REINDEXEDESCAPEACHECKEYBEFOREIGNOREGEXPLAINSTEADDATABASELECT       */

  153772. /*   ABLEFTHENDEFERRABLELSEXCLUDELETEMPORARYCONSTRAINTERSECTIES         */

  153773. /*   AVEPOINTOFFSETRANSACTIONATURALTERAISEXCEPTRIGGEREFERENCES          */

  153774. /*   UNIQUERYWITHOUTERELEASEXCLUSIVEXISTSATTACHAVINGLOBEGINNERANGE      */

  153775. /*   BETWEENOTHINGROUPSCASCADETACHCASECOLLATECREATECURRENT_DATE         */

  153776. /*   IMMEDIATEJOINSERTLIKEMATCHPLANALYZEPRAGMABORTUPDATEVALUES          */

  153777. /*   VIRTUALIMITWHENOTNULLWHERECURSIVEAFTERENAMEANDEFAULT               */

  153778. /*   AUTOINCREMENTCASTCOLUMNCOMMITCONFLICTCROSSCURRENT_TIMESTAMP        */

  153779. /*   ARTITIONDEFERREDISTINCTDROPRECEDINGFAILFILTEREPLACEFOLLOWING       */

  153780. /*   FROMFULLIFISNULLORDERESTRICTOTHERSOVERIGHTROLLBACKROWS             */

  153781. /*   UNBOUNDEDUNIONUSINGVACUUMVIEWINDOWBYINITIALLYPRIMARY               */

  153782. static const char zKWText[628] = {

  153783.   'R','E','I','N','D','E','X','E','D','E','S','C','A','P','E','A','C','H',

  153784.   'E','C','K','E','Y','B','E','F','O','R','E','I','G','N','O','R','E','G',

  153785.   'E','X','P','L','A','I','N','S','T','E','A','D','D','A','T','A','B','A',

  153786.   'S','E','L','E','C','T','A','B','L','E','F','T','H','E','N','D','E','F',

  153787.   'E','R','R','A','B','L','E','L','S','E','X','C','L','U','D','E','L','E',

  153788.   'T','E','M','P','O','R','A','R','Y','C','O','N','S','T','R','A','I','N',

  153789.   'T','E','R','S','E','C','T','I','E','S','A','V','E','P','O','I','N','T',

  153790.   'O','F','F','S','E','T','R','A','N','S','A','C','T','I','O','N','A','T',

  153791.   'U','R','A','L','T','E','R','A','I','S','E','X','C','E','P','T','R','I',

  153792.   'G','G','E','R','E','F','E','R','E','N','C','E','S','U','N','I','Q','U',

  153793.   'E','R','Y','W','I','T','H','O','U','T','E','R','E','L','E','A','S','E',

  153794.   'X','C','L','U','S','I','V','E','X','I','S','T','S','A','T','T','A','C',

  153795.   'H','A','V','I','N','G','L','O','B','E','G','I','N','N','E','R','A','N',

  153796.   'G','E','B','E','T','W','E','E','N','O','T','H','I','N','G','R','O','U',

  153797.   'P','S','C','A','S','C','A','D','E','T','A','C','H','C','A','S','E','C',

  153798.   'O','L','L','A','T','E','C','R','E','A','T','E','C','U','R','R','E','N',

  153799.   'T','_','D','A','T','E','I','M','M','E','D','I','A','T','E','J','O','I',

  153800.   'N','S','E','R','T','L','I','K','E','M','A','T','C','H','P','L','A','N',

  153801.   'A','L','Y','Z','E','P','R','A','G','M','A','B','O','R','T','U','P','D',

  153802.   'A','T','E','V','A','L','U','E','S','V','I','R','T','U','A','L','I','M',

  153803.   'I','T','W','H','E','N','O','T','N','U','L','L','W','H','E','R','E','C',

  153804.   'U','R','S','I','V','E','A','F','T','E','R','E','N','A','M','E','A','N',

  153805.   'D','E','F','A','U','L','T','A','U','T','O','I','N','C','R','E','M','E',

  153806.   'N','T','C','A','S','T','C','O','L','U','M','N','C','O','M','M','I','T',

  153807.   'C','O','N','F','L','I','C','T','C','R','O','S','S','C','U','R','R','E',

  153808.   'N','T','_','T','I','M','E','S','T','A','M','P','A','R','T','I','T','I',

  153809.   'O','N','D','E','F','E','R','R','E','D','I','S','T','I','N','C','T','D',

  153810.   'R','O','P','R','E','C','E','D','I','N','G','F','A','I','L','F','I','L',

  153811.   'T','E','R','E','P','L','A','C','E','F','O','L','L','O','W','I','N','G',

  153812.   'F','R','O','M','F','U','L','L','I','F','I','S','N','U','L','L','O','R',

  153813.   'D','E','R','E','S','T','R','I','C','T','O','T','H','E','R','S','O','V',

  153814.   'E','R','I','G','H','T','R','O','L','L','B','A','C','K','R','O','W','S',

  153815.   'U','N','B','O','U','N','D','E','D','U','N','I','O','N','U','S','I','N',

  153816.   'G','V','A','C','U','U','M','V','I','E','W','I','N','D','O','W','B','Y',

  153817.   'I','N','I','T','I','A','L','L','Y','P','R','I','M','A','R','Y',

  153818. };

  153819. /* aKWHash[i] is the hash value for the i-th keyword */

  153820. static const unsigned char aKWHash[127] = {

  153821.     75, 111, 127,  73, 108,  29,   0,   0,  83,   0,  77,  63,   0,

  153822.     37,  33,  78,  15,   0, 126,  86,  57, 120, 128,  19,   0,   0,

  153823.    133,   0, 131, 123,   0,  22,  98,   0,   9,   0,   0, 117,  71,

  153824.      0,  69,   6,   0,  49,  95, 140,   0, 129, 106,   0,   0,  54,

  153825.      0, 109,  24,   0,  17,   0, 134,  56,  23,  26,   5,  58, 135,

  153826.    101,   0,   0, 139, 112,  62, 138,  59, 115,  65,   0,  96,   0,

  153827.    105,  45,   0, 104,   0,   0,   0, 100,  97, 102, 107, 119,  14,

  153828.     31, 118,   0,  81,   0, 136, 116, 137,  61, 124, 132,  80, 121,

  153829.     88,  30,  85,   0,   0,  99,  35, 125, 122,   0, 130,   0,   0,

  153830.     41,   0,  91,  89,  90,   0,  20,  87, 113,  82,

  153831. };

  153832. /* aKWNext[] forms the hash collision chain.  If aKWHash[i]==0

  153833. ** then the i-th keyword has no more hash collisions.  Otherwise,

  153834. ** the next keyword with the same hash is aKWHash[i]-1. */

  153835. static const unsigned char aKWNext[140] = {

  153836.      0,   0,   0,   0,   4,   0,   0,   0,   0,   0,   0,   0,   0,

  153837.      0,   2,   0,   0,   0,   0,   0,   0,  13,   0,   0,   0,   0,

  153838.      0,   0,   0,  21,   0,   0,  12,   0,   0,   0,   0,   0,   0,

  153839.      7,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,

  153840.     51,  28,   0,   0,  38,   0,   0,   0,  44,   0,   0,   0,   3,

  153841.      0,   0,  67,   1,  66,   0,   0,   0,  36,   0,  47,   0,   0,

  153842.      0,   0,   0,  48,  50,  76,   0,   0,  42,   0,  60,   0,   0,

  153843.      0,  43,   0,  16,  55,  10,   0,   0,   0,   0,   0,   0,   0,

  153844.     11,  72,  93,   0,   0,   8,   0, 110,   0, 103,  40,  53,  70,

  153845.      0, 114,   0,  74,  52,   0,   0,  92,  39,  46,   0,  68,  32,

  153846.     84,   0,  34,  27,  25,  18,  94,   0,  64,  79,

  153847. };

  153848. /* aKWLen[i] is the length (in bytes) of the i-th keyword */

  153849. static const unsigned char aKWLen[140] = {

  153850.      7,   7,   5,   4,   6,   4,   5,   3,   6,   7,   3,   6,   6,

  153851.      7,   7,   3,   8,   2,   6,   5,   4,   4,   3,  10,   4,   7,

  153852.      6,   9,   4,   2,  10,   9,   4,   9,   4,   6,   2,   3,  11,

  153853.      6,   2,   7,   5,   5,   6,   7,  10,   6,   5,   7,   4,   5,

  153854.      7,   9,   6,   6,   6,   4,   5,   5,   5,   7,   7,   6,   5,

  153855.      7,   3,   6,   4,   7,   6,  12,   9,   4,   6,   4,   5,   4,

  153856.      7,   6,   5,   6,   6,   7,   5,   4,   7,   3,   2,   4,   5,

  153857.      9,   5,   6,   3,   7,  13,   2,   2,   4,   6,   6,   8,   5,

  153858.     17,  12,   7,   9,   8,   8,   2,   4,   9,   4,   6,   7,   9,

  153859.      4,   4,   2,   6,   5,   8,   6,   4,   5,   8,   4,   3,   9,

  153860.      5,   5,   6,   4,   6,   2,   2,   9,   3,   7,

  153861. };

  153862. /* aKWOffset[i] is the index into zKWText[] of the start of

  153863. ** the text for the i-th keyword. */

  153864. static const unsigned short int aKWOffset[140] = {

  153865.      0,   2,   2,   8,   9,  14,  16,  20,  23,  25,  25,  29,  33,

  153866.     36,  41,  46,  48,  53,  54,  59,  62,  65,  67,  69,  78,  81,

  153867.     86,  90,  90,  94,  99, 106, 114, 117, 123, 126, 126, 129, 131,

  153868.    136, 140, 141, 146, 150, 154, 159, 165, 175, 178, 183, 183, 187,

  153869.    191, 197, 205, 211, 216, 221, 224, 227, 231, 236, 242, 248, 248,

  153870.    254, 255, 259, 265, 269, 276, 282, 294, 303, 305, 311, 315, 320,

  153871.    322, 329, 334, 339, 345, 351, 357, 362, 365, 365, 365, 368, 372,

  153872.    375, 384, 388, 394, 396, 403, 405, 407, 416, 420, 426, 432, 440,

  153873.    445, 445, 445, 461, 470, 477, 478, 485, 488, 497, 501, 506, 513,

  153874.    522, 526, 530, 532, 538, 542, 550, 556, 559, 564, 572, 572, 576,

  153875.    585, 590, 595, 601, 604, 607, 610, 612, 617, 621,

  153876. };

  153877. /* aKWCode[i] is the parser symbol code for the i-th keyword */

  153878. static const unsigned char aKWCode[140] = {

  153879.   TK_REINDEX,    TK_INDEXED,    TK_INDEX,      TK_DESC,       TK_ESCAPE,     

  153880.   TK_EACH,       TK_CHECK,      TK_KEY,        TK_BEFORE,     TK_FOREIGN,    

  153881.   TK_FOR,        TK_IGNORE,     TK_LIKE_KW,    TK_EXPLAIN,    TK_INSTEAD,    

  153882.   TK_ADD,        TK_DATABASE,   TK_AS,         TK_SELECT,     TK_TABLE,      

  153883.   TK_JOIN_KW,    TK_THEN,       TK_END,        TK_DEFERRABLE, TK_ELSE,       

  153884.   TK_EXCLUDE,    TK_DELETE,     TK_TEMP,       TK_TEMP,       TK_OR,         

  153885.   TK_CONSTRAINT, TK_INTERSECT,  TK_TIES,       TK_SAVEPOINT,  TK_INTO,       

  153886.   TK_OFFSET,     TK_OF,         TK_SET,        TK_TRANSACTION,TK_ACTION,     

  153887.   TK_ON,         TK_JOIN_KW,    TK_ALTER,      TK_RAISE,      TK_EXCEPT,     

  153888.   TK_TRIGGER,    TK_REFERENCES, TK_UNIQUE,     TK_QUERY,      TK_WITHOUT,    

  153889.   TK_WITH,       TK_JOIN_KW,    TK_RELEASE,    TK_EXCLUSIVE,  TK_EXISTS,     

  153890.   TK_ATTACH,     TK_HAVING,     TK_LIKE_KW,    TK_BEGIN,      TK_JOIN_KW,    

  153891.   TK_RANGE,      TK_BETWEEN,    TK_NOTHING,    TK_GROUPS,     TK_GROUP,      

  153892.   TK_CASCADE,    TK_ASC,        TK_DETACH,     TK_CASE,       TK_COLLATE,    

  153893.   TK_CREATE,     TK_CTIME_KW,   TK_IMMEDIATE,  TK_JOIN,       TK_INSERT,     

  153894.   TK_LIKE_KW,    TK_MATCH,      TK_PLAN,       TK_ANALYZE,    TK_PRAGMA,     

  153895.   TK_ABORT,      TK_UPDATE,     TK_VALUES,     TK_VIRTUAL,    TK_LIMIT,      

  153896.   TK_WHEN,       TK_NOTNULL,    TK_NOT,        TK_NO,         TK_NULL,       

  153897.   TK_WHERE,      TK_RECURSIVE,  TK_AFTER,      TK_RENAME,     TK_AND,        

  153898.   TK_DEFAULT,    TK_AUTOINCR,   TK_TO,         TK_IN,         TK_CAST,       

  153899.   TK_COLUMNKW,   TK_COMMIT,     TK_CONFLICT,   TK_JOIN_KW,    TK_CTIME_KW,   

  153900.   TK_CTIME_KW,   TK_CURRENT,    TK_PARTITION,  TK_DEFERRED,   TK_DISTINCT,   

  153901.   TK_IS,         TK_DROP,       TK_PRECEDING,  TK_FAIL,       TK_FILTER,     

  153902.   TK_REPLACE,    TK_FOLLOWING,  TK_FROM,       TK_JOIN_KW,    TK_IF,         

  153903.   TK_ISNULL,     TK_ORDER,      TK_RESTRICT,   TK_OTHERS,     TK_OVER,       

  153904.   TK_JOIN_KW,    TK_ROLLBACK,   TK_ROWS,       TK_ROW,        TK_UNBOUNDED,  

  153905.   TK_UNION,      TK_USING,      TK_VACUUM,     TK_VIEW,       TK_WINDOW,     

  153906.   TK_DO,         TK_BY,         TK_INITIALLY,  TK_ALL,        TK_PRIMARY,    

  153907. };

  153908. /* Check to see if z[0..n-1] is a keyword. If it is, write the

  153909. ** parser symbol code for that keyword into *pType.  Always

  153910. ** return the integer n (the length of the token). */

  153911. static int keywordCode(const char *z, int n, int *pType){

  153912.   int i, j;

  153913.   const char *zKW;

  153914.   if( n>=2 ){

  153915.     i = ((charMap(z[0])*4) ^ (charMap(z[n-1])*3) ^ n) % 127;

  153916.     for(i=((int)aKWHash[i])-1; i>=0; i=((int)aKWNext[i])-1){

  153917.       if( aKWLen[i]!=n ) continue;

  153918.       j = 0;

  153919.       zKW = &zKWText[aKWOffset[i]];

  153920. #ifdef SQLITE_ASCII

  153921.       while( j<n && (z[j]&~0x20)==zKW[j] ){ j++; }

  153922. #endif

  153923. #ifdef SQLITE_EBCDIC

  153924.       while( j<n && toupper(z[j])==zKW[j] ){ j++; }

  153925. #endif

  153926.       if( j<n ) continue;

  153927.       testcase( i==0 ); /* REINDEX */

  153928.       testcase( i==1 ); /* INDEXED */

  153929.       testcase( i==2 ); /* INDEX */

  153930.       testcase( i==3 ); /* DESC */

  153931.       testcase( i==4 ); /* ESCAPE */

  153932.       testcase( i==5 ); /* EACH */

  153933.       testcase( i==6 ); /* CHECK */

  153934.       testcase( i==7 ); /* KEY */

  153935.       testcase( i==8 ); /* BEFORE */

  153936.       testcase( i==9 ); /* FOREIGN */

  153937.       testcase( i==10 ); /* FOR */

  153938.       testcase( i==11 ); /* IGNORE */

  153939.       testcase( i==12 ); /* REGEXP */

  153940.       testcase( i==13 ); /* EXPLAIN */

  153941.       testcase( i==14 ); /* INSTEAD */

  153942.       testcase( i==15 ); /* ADD */

  153943.       testcase( i==16 ); /* DATABASE */

  153944.       testcase( i==17 ); /* AS */

  153945.       testcase( i==18 ); /* SELECT */

  153946.       testcase( i==19 ); /* TABLE */

  153947.       testcase( i==20 ); /* LEFT */

  153948.       testcase( i==21 ); /* THEN */

  153949.       testcase( i==22 ); /* END */

  153950.       testcase( i==23 ); /* DEFERRABLE */

  153951.       testcase( i==24 ); /* ELSE */

  153952.       testcase( i==25 ); /* EXCLUDE */

  153953.       testcase( i==26 ); /* DELETE */

  153954.       testcase( i==27 ); /* TEMPORARY */

  153955.       testcase( i==28 ); /* TEMP */

  153956.       testcase( i==29 ); /* OR */

  153957.       testcase( i==30 ); /* CONSTRAINT */

  153958.       testcase( i==31 ); /* INTERSECT */

  153959.       testcase( i==32 ); /* TIES */

  153960.       testcase( i==33 ); /* SAVEPOINT */

  153961.       testcase( i==34 ); /* INTO */

  153962.       testcase( i==35 ); /* OFFSET */

  153963.       testcase( i==36 ); /* OF */

  153964.       testcase( i==37 ); /* SET */

  153965.       testcase( i==38 ); /* TRANSACTION */

  153966.       testcase( i==39 ); /* ACTION */

  153967.       testcase( i==40 ); /* ON */

  153968.       testcase( i==41 ); /* NATURAL */

  153969.       testcase( i==42 ); /* ALTER */

  153970.       testcase( i==43 ); /* RAISE */

  153971.       testcase( i==44 ); /* EXCEPT */

  153972.       testcase( i==45 ); /* TRIGGER */

  153973.       testcase( i==46 ); /* REFERENCES */

  153974.       testcase( i==47 ); /* UNIQUE */

  153975.       testcase( i==48 ); /* QUERY */

  153976.       testcase( i==49 ); /* WITHOUT */

  153977.       testcase( i==50 ); /* WITH */

  153978.       testcase( i==51 ); /* OUTER */

  153979.       testcase( i==52 ); /* RELEASE */

  153980.       testcase( i==53 ); /* EXCLUSIVE */

  153981.       testcase( i==54 ); /* EXISTS */

  153982.       testcase( i==55 ); /* ATTACH */

  153983.       testcase( i==56 ); /* HAVING */

  153984.       testcase( i==57 ); /* GLOB */

  153985.       testcase( i==58 ); /* BEGIN */

  153986.       testcase( i==59 ); /* INNER */

  153987.       testcase( i==60 ); /* RANGE */

  153988.       testcase( i==61 ); /* BETWEEN */

  153989.       testcase( i==62 ); /* NOTHING */

  153990.       testcase( i==63 ); /* GROUPS */

  153991.       testcase( i==64 ); /* GROUP */

  153992.       testcase( i==65 ); /* CASCADE */

  153993.       testcase( i==66 ); /* ASC */

  153994.       testcase( i==67 ); /* DETACH */

  153995.       testcase( i==68 ); /* CASE */

  153996.       testcase( i==69 ); /* COLLATE */

  153997.       testcase( i==70 ); /* CREATE */

  153998.       testcase( i==71 ); /* CURRENT_DATE */

  153999.       testcase( i==72 ); /* IMMEDIATE */

  154000.       testcase( i==73 ); /* JOIN */

  154001.       testcase( i==74 ); /* INSERT */

  154002.       testcase( i==75 ); /* LIKE */

  154003.       testcase( i==76 ); /* MATCH */

  154004.       testcase( i==77 ); /* PLAN */

  154005.       testcase( i==78 ); /* ANALYZE */

  154006.       testcase( i==79 ); /* PRAGMA */

  154007.       testcase( i==80 ); /* ABORT */

  154008.       testcase( i==81 ); /* UPDATE */

  154009.       testcase( i==82 ); /* VALUES */

  154010.       testcase( i==83 ); /* VIRTUAL */

  154011.       testcase( i==84 ); /* LIMIT */

  154012.       testcase( i==85 ); /* WHEN */

  154013.       testcase( i==86 ); /* NOTNULL */

  154014.       testcase( i==87 ); /* NOT */

  154015.       testcase( i==88 ); /* NO */

  154016.       testcase( i==89 ); /* NULL */

  154017.       testcase( i==90 ); /* WHERE */

  154018.       testcase( i==91 ); /* RECURSIVE */

  154019.       testcase( i==92 ); /* AFTER */

  154020.       testcase( i==93 ); /* RENAME */

  154021.       testcase( i==94 ); /* AND */

  154022.       testcase( i==95 ); /* DEFAULT */

  154023.       testcase( i==96 ); /* AUTOINCREMENT */

  154024.       testcase( i==97 ); /* TO */

  154025.       testcase( i==98 ); /* IN */

  154026.       testcase( i==99 ); /* CAST */

  154027.       testcase( i==100 ); /* COLUMN */

  154028.       testcase( i==101 ); /* COMMIT */

  154029.       testcase( i==102 ); /* CONFLICT */

  154030.       testcase( i==103 ); /* CROSS */

  154031.       testcase( i==104 ); /* CURRENT_TIMESTAMP */

  154032.       testcase( i==105 ); /* CURRENT_TIME */

  154033.       testcase( i==106 ); /* CURRENT */

  154034.       testcase( i==107 ); /* PARTITION */

  154035.       testcase( i==108 ); /* DEFERRED */

  154036.       testcase( i==109 ); /* DISTINCT */

  154037.       testcase( i==110 ); /* IS */

  154038.       testcase( i==111 ); /* DROP */

  154039.       testcase( i==112 ); /* PRECEDING */

  154040.       testcase( i==113 ); /* FAIL */

  154041.       testcase( i==114 ); /* FILTER */

  154042.       testcase( i==115 ); /* REPLACE */

  154043.       testcase( i==116 ); /* FOLLOWING */

  154044.       testcase( i==117 ); /* FROM */

  154045.       testcase( i==118 ); /* FULL */

  154046.       testcase( i==119 ); /* IF */

  154047.       testcase( i==120 ); /* ISNULL */

  154048.       testcase( i==121 ); /* ORDER */

  154049.       testcase( i==122 ); /* RESTRICT */

  154050.       testcase( i==123 ); /* OTHERS */

  154051.       testcase( i==124 ); /* OVER */

  154052.       testcase( i==125 ); /* RIGHT */

  154053.       testcase( i==126 ); /* ROLLBACK */

  154054.       testcase( i==127 ); /* ROWS */

  154055.       testcase( i==128 ); /* ROW */

  154056.       testcase( i==129 ); /* UNBOUNDED */

  154057.       testcase( i==130 ); /* UNION */

  154058.       testcase( i==131 ); /* USING */

  154059.       testcase( i==132 ); /* VACUUM */

  154060.       testcase( i==133 ); /* VIEW */

  154061.       testcase( i==134 ); /* WINDOW */

  154062.       testcase( i==135 ); /* DO */

  154063.       testcase( i==136 ); /* BY */

  154064.       testcase( i==137 ); /* INITIALLY */

  154065.       testcase( i==138 ); /* ALL */

  154066.       testcase( i==139 ); /* PRIMARY */

  154067.       *pType = aKWCode[i];

  154068.       break;

  154069.     }

  154070.   }

  154071.   return n;

  154072. }

  154073. SQLITE_PRIVATE int sqlite3KeywordCode(const unsigned char *z, int n){

  154074.   int id = TK_ID;

  154075.   keywordCode((char*)z, n, &id);

  154076.   return id;

  154077. }

  154078. #define SQLITE_N_KEYWORD 140

  154079. SQLITE_API int sqlite3_keyword_name(int i,const char **pzName,int *pnName){

  154080.   if( i<0 || i>=SQLITE_N_KEYWORD ) return SQLITE_ERROR;

  154081.   *pzName = zKWText + aKWOffset[i];

  154082.   *pnName = aKWLen[i];

  154083.   return SQLITE_OK;

  154084. }

  154085. SQLITE_API int sqlite3_keyword_count(void){ return SQLITE_N_KEYWORD; }

  154086. SQLITE_API int sqlite3_keyword_check(const char *zName, int nName){

  154087.   return TK_ID!=sqlite3KeywordCode((const u8*)zName, nName);

  154088. }

  154089. 

  154090. /************** End of keywordhash.h *****************************************/

  154091. /************** Continuing where we left off in tokenize.c *******************/

  154092. 

  154093. 

  154094. /*

  154095. ** If X is a character that can be used in an identifier then

  154096. ** IdChar(X) will be true.  Otherwise it is false.

  154097. **

  154098. ** For ASCII, any character with the high-order bit set is

  154099. ** allowed in an identifier.  For 7-bit characters, 

  154100. ** sqlite3IsIdChar[X] must be 1.

  154101. **

  154102. ** For EBCDIC, the rules are more complex but have the same

  154103. ** end result.

  154104. **

  154105. ** Ticket #1066.  the SQL standard does not allow '$' in the

  154106. ** middle of identifiers.  But many SQL implementations do. 

  154107. ** SQLite will allow '$' in identifiers for compatibility.

  154108. ** But the feature is undocumented.

  154109. */

  154110. #ifdef SQLITE_ASCII

  154111. #define IdChar(C)  ((sqlite3CtypeMap[(unsigned char)C]&0x46)!=0)

  154112. #endif

  154113. #ifdef SQLITE_EBCDIC

  154114. SQLITE_PRIVATE const char sqlite3IsEbcdicIdChar[] = {

  154115. /* x0 x1 x2 x3 x4 x5 x6 x7 x8 x9 xA xB xC xD xE xF */

  154116.     0, 0, 1, 1, 1, 1, 1, 1, 1, 1, 0, 0, 0, 0, 0, 0,  /* 4x */

  154117.     0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0, 1, 0, 0, 0, 0,  /* 5x */

  154118.     0, 0, 1, 1, 1, 1, 1, 1, 1, 1, 0, 0, 0, 1, 0, 0,  /* 6x */

  154119.     0, 1, 1, 1, 1, 1, 1, 1, 1, 0, 0, 0, 0, 0, 0, 0,  /* 7x */

  154120.     0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0, 0, 1, 1, 1, 0,  /* 8x */

  154121.     0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0, 0, 1, 0, 1, 0,  /* 9x */

  154122.     1, 0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0, 1, 1, 1, 0,  /* Ax */

  154123.     0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,  /* Bx */

  154124.     0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0, 1, 1, 1, 1, 1,  /* Cx */

  154125.     0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0, 1, 1, 1, 1, 1,  /* Dx */

  154126.     0, 0, 1, 1, 1, 1, 1, 1, 1, 1, 0, 1, 1, 1, 1, 1,  /* Ex */

  154127.     1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0, 1, 1, 1, 1, 0,  /* Fx */

  154128. };

  154129. #define IdChar(C)  (((c=C)>=0x42 && sqlite3IsEbcdicIdChar[c-0x40]))

  154130. #endif

  154131. 

  154132. /* Make the IdChar function accessible from ctime.c and alter.c */

  154133. SQLITE_PRIVATE int sqlite3IsIdChar(u8 c){ return IdChar(c); }

  154134. 

  154135. #ifndef SQLITE_OMIT_WINDOWFUNC

  154136. /*

  154137. ** Return the id of the next token in string (*pz). Before returning, set

  154138. ** (*pz) to point to the byte following the parsed token.

  154139. */

  154140. static int getToken(const unsigned char **pz){

  154141.   const unsigned char *z = *pz;

  154142.   int t;                          /* Token type to return */

  154143.   do {

  154144.     z += sqlite3GetToken(z, &t);

  154145.   }while( t==TK_SPACE );

  154146.   if( t==TK_ID 

  154147.    || t==TK_STRING 

  154148.    || t==TK_JOIN_KW 

  154149.    || t==TK_WINDOW 

  154150.    || t==TK_OVER 

  154151.    || sqlite3ParserFallback(t)==TK_ID 

  154152.   ){

  154153.     t = TK_ID;

  154154.   }

  154155.   *pz = z;

  154156.   return t;

  154157. }

  154158. 

  154159. /*

  154160. ** The following three functions are called immediately after the tokenizer

  154161. ** reads the keywords WINDOW, OVER and FILTER, respectively, to determine

  154162. ** whether the token should be treated as a keyword or an SQL identifier.

  154163. ** This cannot be handled by the usual lemon %fallback method, due to

  154164. ** the ambiguity in some constructions. e.g.

  154165. **

  154166. **   SELECT sum(x) OVER ...

  154167. **

  154168. ** In the above, "OVER" might be a keyword, or it might be an alias for the 

  154169. ** sum(x) expression. If a "%fallback ID OVER" directive were added to 

  154170. ** grammar, then SQLite would always treat "OVER" as an alias, making it

  154171. ** impossible to call a window-function without a FILTER clause.

  154172. **

  154173. ** WINDOW is treated as a keyword if:

  154174. **

  154175. **   * the following token is an identifier, or a keyword that can fallback

  154176. **     to being an identifier, and

  154177. **   * the token after than one is TK_AS.

  154178. **

  154179. ** OVER is a keyword if:

  154180. **

  154181. **   * the previous token was TK_RP, and

  154182. **   * the next token is either TK_LP or an identifier.

  154183. **

  154184. ** FILTER is a keyword if:

  154185. **

  154186. **   * the previous token was TK_RP, and

  154187. **   * the next token is TK_LP.

  154188. */

  154189. static int analyzeWindowKeyword(const unsigned char *z){

  154190.   int t;

  154191.   t = getToken(&z);

  154192.   if( t!=TK_ID ) return TK_ID;

  154193.   t = getToken(&z);

  154194.   if( t!=TK_AS ) return TK_ID;

  154195.   return TK_WINDOW;

  154196. }

  154197. static int analyzeOverKeyword(const unsigned char *z, int lastToken){

  154198.   if( lastToken==TK_RP ){

  154199.     int t = getToken(&z);

  154200.     if( t==TK_LP || t==TK_ID ) return TK_OVER;

  154201.   }

  154202.   return TK_ID;

  154203. }

  154204. static int analyzeFilterKeyword(const unsigned char *z, int lastToken){

  154205.   if( lastToken==TK_RP && getToken(&z)==TK_LP ){

  154206.     return TK_FILTER;

  154207.   }

  154208.   return TK_ID;

  154209. }

  154210. #endif /* SQLITE_OMIT_WINDOWFUNC */

  154211. 

  154212. /*

  154213. ** Return the length (in bytes) of the token that begins at z[0]. 

  154214. ** Store the token type in *tokenType before returning.

  154215. */

  154216. SQLITE_PRIVATE int sqlite3GetToken(const unsigned char *z, int *tokenType){

  154217.   int i, c;

  154218.   switch( aiClass[*z] ){  /* Switch on the character-class of the first byte

  154219.                           ** of the token. See the comment on the CC_ defines

  154220.                           ** above. */

  154221.     case CC_SPACE: {

  154222.       testcase( z[0]==' ' );

  154223.       testcase( z[0]=='\t' );

  154224.       testcase( z[0]=='\n' );

  154225.       testcase( z[0]=='\f' );

  154226.       testcase( z[0]=='\r' );

  154227.       for(i=1; sqlite3Isspace(z[i]); i++){}

  154228.       *tokenType = TK_SPACE;

  154229.       return i;

  154230.     }

  154231.     case CC_MINUS: {

  154232.       if( z[1]=='-' ){

  154233.         for(i=2; (c=z[i])!=0 && c!='\n'; i++){}

  154234.         *tokenType = TK_SPACE;   /* IMP: R-22934-25134 */

  154235.         return i;

  154236.       }

  154237.       *tokenType = TK_MINUS;

  154238.       return 1;

  154239.     }

  154240.     case CC_LP: {

  154241.       *tokenType = TK_LP;

  154242.       return 1;

  154243.     }

  154244.     case CC_RP: {

  154245.       *tokenType = TK_RP;

  154246.       return 1;

  154247.     }

  154248.     case CC_SEMI: {

  154249.       *tokenType = TK_SEMI;

  154250.       return 1;

  154251.     }

  154252.     case CC_PLUS: {

  154253.       *tokenType = TK_PLUS;

  154254.       return 1;

  154255.     }

  154256.     case CC_STAR: {

  154257.       *tokenType = TK_STAR;

  154258.       return 1;

  154259.     }

  154260.     case CC_SLASH: {

  154261.       if( z[1]!='*' || z[2]==0 ){

  154262.         *tokenType = TK_SLASH;

  154263.         return 1;

  154264.       }

  154265.       for(i=3, c=z[2]; (c!='*' || z[i]!='/') && (c=z[i])!=0; i++){}

  154266.       if( c ) i++;

  154267.       *tokenType = TK_SPACE;   /* IMP: R-22934-25134 */

  154268.       return i;

  154269.     }

  154270.     case CC_PERCENT: {

  154271.       *tokenType = TK_REM;

  154272.       return 1;

  154273.     }

  154274.     case CC_EQ: {

  154275.       *tokenType = TK_EQ;

  154276.       return 1 + (z[1]=='=');

  154277.     }

  154278.     case CC_LT: {

  154279.       if( (c=z[1])=='=' ){

  154280.         *tokenType = TK_LE;

  154281.         return 2;

  154282.       }else if( c=='>' ){

  154283.         *tokenType = TK_NE;

  154284.         return 2;

  154285.       }else if( c=='<' ){

  154286.         *tokenType = TK_LSHIFT;

  154287.         return 2;

  154288.       }else{

  154289.         *tokenType = TK_LT;

  154290.         return 1;

  154291.       }

  154292.     }

  154293.     case CC_GT: {

  154294.       if( (c=z[1])=='=' ){

  154295.         *tokenType = TK_GE;

  154296.         return 2;

  154297.       }else if( c=='>' ){

  154298.         *tokenType = TK_RSHIFT;

  154299.         return 2;

  154300.       }else{

  154301.         *tokenType = TK_GT;

  154302.         return 1;

  154303.       }

  154304.     }

  154305.     case CC_BANG: {

  154306.       if( z[1]!='=' ){

  154307.         *tokenType = TK_ILLEGAL;

  154308.         return 1;

  154309.       }else{

  154310.         *tokenType = TK_NE;

  154311.         return 2;

  154312.       }

  154313.     }

  154314.     case CC_PIPE: {

  154315.       if( z[1]!='|' ){

  154316.         *tokenType = TK_BITOR;

  154317.         return 1;

  154318.       }else{

  154319.         *tokenType = TK_CONCAT;

  154320.         return 2;

  154321.       }

  154322.     }

  154323.     case CC_COMMA: {

  154324.       *tokenType = TK_COMMA;

  154325.       return 1;

  154326.     }

  154327.     case CC_AND: {

  154328.       *tokenType = TK_BITAND;

  154329.       return 1;

  154330.     }

  154331.     case CC_TILDA: {

  154332.       *tokenType = TK_BITNOT;

  154333.       return 1;

  154334.     }

  154335.     case CC_QUOTE: {

  154336.       int delim = z[0];

  154337.       testcase( delim=='`' );

  154338.       testcase( delim=='\'' );

  154339.       testcase( delim=='"' );

  154340.       for(i=1; (c=z[i])!=0; i++){

  154341.         if( c==delim ){

  154342.           if( z[i+1]==delim ){

  154343.             i++;

  154344.           }else{

  154345.             break;

  154346.           }

  154347.         }

  154348.       }

  154349.       if( c=='\'' ){

  154350.         *tokenType = TK_STRING;

  154351.         return i+1;

  154352.       }else if( c!=0 ){

  154353.         *tokenType = TK_ID;

  154354.         return i+1;

  154355.       }else{

  154356.         *tokenType = TK_ILLEGAL;

  154357.         return i;

  154358.       }

  154359.     }

  154360.     case CC_DOT: {

  154361. #ifndef SQLITE_OMIT_FLOATING_POINT

  154362.       if( !sqlite3Isdigit(z[1]) )

  154363. #endif

  154364.       {

  154365.         *tokenType = TK_DOT;

  154366.         return 1;

  154367.       }

  154368.       /* If the next character is a digit, this is a floating point

  154369.       ** number that begins with ".".  Fall thru into the next case */

  154370.     }

  154371.     case CC_DIGIT: {

  154372.       testcase( z[0]=='0' );  testcase( z[0]=='1' );  testcase( z[0]=='2' );

  154373.       testcase( z[0]=='3' );  testcase( z[0]=='4' );  testcase( z[0]=='5' );

  154374.       testcase( z[0]=='6' );  testcase( z[0]=='7' );  testcase( z[0]=='8' );

  154375.       testcase( z[0]=='9' );

  154376.       *tokenType = TK_INTEGER;

  154377. #ifndef SQLITE_OMIT_HEX_INTEGER

  154378.       if( z[0]=='0' && (z[1]=='x' || z[1]=='X') && sqlite3Isxdigit(z[2]) ){

  154379.         for(i=3; sqlite3Isxdigit(z[i]); i++){}

  154380.         return i;

  154381.       }

  154382. #endif

  154383.       for(i=0; sqlite3Isdigit(z[i]); i++){}

  154384. #ifndef SQLITE_OMIT_FLOATING_POINT

  154385.       if( z[i]=='.' ){

  154386.         i++;

  154387.         while( sqlite3Isdigit(z[i]) ){ i++; }

  154388.         *tokenType = TK_FLOAT;

  154389.       }

  154390.       if( (z[i]=='e' || z[i]=='E') &&

  154391.            ( sqlite3Isdigit(z[i+1]) 

  154392.             || ((z[i+1]=='+' || z[i+1]=='-') && sqlite3Isdigit(z[i+2]))

  154393.            )

  154394.       ){

  154395.         i += 2;

  154396.         while( sqlite3Isdigit(z[i]) ){ i++; }

  154397.         *tokenType = TK_FLOAT;

  154398.       }

  154399. #endif

  154400.       while( IdChar(z[i]) ){

  154401.         *tokenType = TK_ILLEGAL;

  154402.         i++;

  154403.       }

  154404.       return i;

  154405.     }

  154406.     case CC_QUOTE2: {

  154407.       for(i=1, c=z[0]; c!=']' && (c=z[i])!=0; i++){}

  154408.       *tokenType = c==']' ? TK_ID : TK_ILLEGAL;

  154409.       return i;

  154410.     }

  154411.     case CC_VARNUM: {

  154412.       *tokenType = TK_VARIABLE;

  154413.       for(i=1; sqlite3Isdigit(z[i]); i++){}

  154414.       return i;

  154415.     }

  154416.     case CC_DOLLAR:

  154417.     case CC_VARALPHA: {

  154418.       int n = 0;

  154419.       testcase( z[0]=='$' );  testcase( z[0]=='@' );

  154420.       testcase( z[0]==':' );  testcase( z[0]=='#' );

  154421.       *tokenType = TK_VARIABLE;

  154422.       for(i=1; (c=z[i])!=0; i++){

  154423.         if( IdChar(c) ){

  154424.           n++;

  154425. #ifndef SQLITE_OMIT_TCL_VARIABLE

  154426.         }else if( c=='(' && n>0 ){

  154427.           do{

  154428.             i++;

  154429.           }while( (c=z[i])!=0 && !sqlite3Isspace(c) && c!=')' );

  154430.           if( c==')' ){

  154431.             i++;

  154432.           }else{

  154433.             *tokenType = TK_ILLEGAL;

  154434.           }

  154435.           break;

  154436.         }else if( c==':' && z[i+1]==':' ){

  154437.           i++;

  154438. #endif

  154439.         }else{

  154440.           break;

  154441.         }

  154442.       }

  154443.       if( n==0 ) *tokenType = TK_ILLEGAL;

  154444.       return i;

  154445.     }

  154446.     case CC_KYWD: {

  154447.       for(i=1; aiClass[z[i]]<=CC_KYWD; i++){}

  154448.       if( IdChar(z[i]) ){

  154449.         /* This token started out using characters that can appear in keywords,

  154450.         ** but z[i] is a character not allowed within keywords, so this must

  154451.         ** be an identifier instead */

  154452.         i++;

  154453.         break;

  154454.       }

  154455.       *tokenType = TK_ID;

  154456.       return keywordCode((char*)z, i, tokenType);

  154457.     }

  154458.     case CC_X: {

  154459. #ifndef SQLITE_OMIT_BLOB_LITERAL

  154460.       testcase( z[0]=='x' ); testcase( z[0]=='X' );

  154461.       if( z[1]=='\'' ){

  154462.         *tokenType = TK_BLOB;

  154463.         for(i=2; sqlite3Isxdigit(z[i]); i++){}

  154464.         if( z[i]!='\'' || i%2 ){

  154465.           *tokenType = TK_ILLEGAL;

  154466.           while( z[i] && z[i]!='\'' ){ i++; }

  154467.         }

  154468.         if( z[i] ) i++;

  154469.         return i;

  154470.       }

  154471. #endif

  154472.       /* If it is not a BLOB literal, then it must be an ID, since no

  154473.       ** SQL keywords start with the letter 'x'.  Fall through */

  154474.     }

  154475.     case CC_ID: {

  154476.       i = 1;

  154477.       break;

  154478.     }

  154479.     case CC_NUL: {

  154480.       *tokenType = TK_ILLEGAL;

  154481.       return 0;

  154482.     }

  154483.     default: {

  154484.       *tokenType = TK_ILLEGAL;

  154485.       return 1;

  154486.     }

  154487.   }

  154488.   while( IdChar(z[i]) ){ i++; }

  154489.   *tokenType = TK_ID;

  154490.   return i;

  154491. }

  154492. 

  154493. /*

  154494. ** Run the parser on the given SQL string.  The parser structure is

  154495. ** passed in.  An SQLITE_ status code is returned.  If an error occurs

  154496. ** then an and attempt is made to write an error message into 

  154497. ** memory obtained from sqlite3_malloc() and to make *pzErrMsg point to that

  154498. ** error message.

  154499. */

  154500. SQLITE_PRIVATE int sqlite3RunParser(Parse *pParse, const char *zSql, char **pzErrMsg){

  154501.   int nErr = 0;                   /* Number of errors encountered */

  154502.   void *pEngine;                  /* The LEMON-generated LALR(1) parser */

  154503.   int n = 0;                      /* Length of the next token token */

  154504.   int tokenType;                  /* type of the next token */

  154505.   int lastTokenParsed = -1;       /* type of the previous token */

  154506.   sqlite3 *db = pParse->db;       /* The database connection */

  154507.   int mxSqlLen;                   /* Max length of an SQL string */

  154508. #ifdef sqlite3Parser_ENGINEALWAYSONSTACK

  154509.   yyParser sEngine;    /* Space to hold the Lemon-generated Parser object */

  154510. #endif

  154511.   VVA_ONLY( u8 startedWithOom = db->mallocFailed );

  154512. 

  154513.   assert( zSql!=0 );

  154514.   mxSqlLen = db->aLimit[SQLITE_LIMIT_SQL_LENGTH];

  154515.   if( db->nVdbeActive==0 ){

  154516.     db->u1.isInterrupted = 0;

  154517.   }

  154518.   pParse->rc = SQLITE_OK;

  154519.   pParse->zTail = zSql;

  154520.   assert( pzErrMsg!=0 );

  154521. #ifdef SQLITE_DEBUG

  154522.   if( db->flags & SQLITE_ParserTrace ){

  154523.     printf("parser: [[[%s]]]\n", zSql);

  154524.     sqlite3ParserTrace(stdout, "parser: ");

  154525.   }else{

  154526.     sqlite3ParserTrace(0, 0);

  154527.   }

  154528. #endif

  154529. #ifdef sqlite3Parser_ENGINEALWAYSONSTACK

  154530.   pEngine = &sEngine;

  154531.   sqlite3ParserInit(pEngine, pParse);

  154532. #else

  154533.   pEngine = sqlite3ParserAlloc(sqlite3Malloc, pParse);

  154534.   if( pEngine==0 ){

  154535.     sqlite3OomFault(db);

  154536.     return SQLITE_NOMEM_BKPT;

  154537.   }

  154538. #endif

  154539.   assert( pParse->pNewTable==0 );

  154540.   assert( pParse->pNewTrigger==0 );

  154541.   assert( pParse->nVar==0 );

  154542.   assert( pParse->pVList==0 );

  154543.   pParse->pParentParse = db->pParse;

  154544.   db->pParse = pParse;

  154545.   while( 1 ){

  154546.     n = sqlite3GetToken((u8*)zSql, &tokenType);

  154547.     mxSqlLen -= n;

  154548.     if( mxSqlLen<0 ){

  154549.       pParse->rc = SQLITE_TOOBIG;

  154550.       break;

  154551.     }

  154552. #ifndef SQLITE_OMIT_WINDOWFUNC

  154553.     if( tokenType>=TK_WINDOW ){

  154554.       assert( tokenType==TK_SPACE || tokenType==TK_OVER || tokenType==TK_FILTER

  154555.            || tokenType==TK_ILLEGAL || tokenType==TK_WINDOW 

  154556.       );

  154557. #else

  154558.     if( tokenType>=TK_SPACE ){

  154559.       assert( tokenType==TK_SPACE || tokenType==TK_ILLEGAL );

  154560. #endif /* SQLITE_OMIT_WINDOWFUNC */

  154561.       if( db->u1.isInterrupted ){

  154562.         pParse->rc = SQLITE_INTERRUPT;

  154563.         break;

  154564.       }

  154565.       if( tokenType==TK_SPACE ){

  154566.         zSql += n;

  154567.         continue;

  154568.       }

  154569.       if( zSql[0]==0 ){

  154570.         /* Upon reaching the end of input, call the parser two more times

  154571.         ** with tokens TK_SEMI and 0, in that order. */

  154572.         if( lastTokenParsed==TK_SEMI ){

  154573.           tokenType = 0;

  154574.         }else if( lastTokenParsed==0 ){

  154575.           break;

  154576.         }else{

  154577.           tokenType = TK_SEMI;

  154578.         }

  154579.         n = 0;

  154580. #ifndef SQLITE_OMIT_WINDOWFUNC

  154581.       }else if( tokenType==TK_WINDOW ){

  154582.         assert( n==6 );

  154583.         tokenType = analyzeWindowKeyword((const u8*)&zSql[6]);

  154584.       }else if( tokenType==TK_OVER ){

  154585.         assert( n==4 );

  154586.         tokenType = analyzeOverKeyword((const u8*)&zSql[4], lastTokenParsed);

  154587.       }else if( tokenType==TK_FILTER ){

  154588.         assert( n==6 );

  154589.         tokenType = analyzeFilterKeyword((const u8*)&zSql[6], lastTokenParsed);

  154590. #endif /* SQLITE_OMIT_WINDOWFUNC */

  154591.       }else{

  154592.         sqlite3ErrorMsg(pParse, "unrecognized token: \"%.*s\"", n, zSql);

  154593.         break;

  154594.       }

  154595.     }

  154596.     pParse->sLastToken.z = zSql;

  154597.     pParse->sLastToken.n = n;

  154598.     sqlite3Parser(pEngine, tokenType, pParse->sLastToken);

  154599.     lastTokenParsed = tokenType;

  154600.     zSql += n;

  154601.     assert( db->mallocFailed==0 || pParse->rc!=SQLITE_OK || startedWithOom );

  154602.     if( pParse->rc!=SQLITE_OK ) break;

  154603.   }

  154604.   assert( nErr==0 );

  154605. #ifdef YYTRACKMAXSTACKDEPTH

  154606.   sqlite3_mutex_enter(sqlite3MallocMutex());

  154607.   sqlite3StatusHighwater(SQLITE_STATUS_PARSER_STACK,

  154608.       sqlite3ParserStackPeak(pEngine)

  154609.   );

  154610.   sqlite3_mutex_leave(sqlite3MallocMutex());

  154611. #endif /* YYDEBUG */

  154612. #ifdef sqlite3Parser_ENGINEALWAYSONSTACK

  154613.   sqlite3ParserFinalize(pEngine);

  154614. #else

  154615.   sqlite3ParserFree(pEngine, sqlite3_free);

  154616. #endif

  154617.   if( db->mallocFailed ){

  154618.     pParse->rc = SQLITE_NOMEM_BKPT;

  154619.   }

  154620.   if( pParse->rc!=SQLITE_OK && pParse->rc!=SQLITE_DONE && pParse->zErrMsg==0 ){

  154621.     pParse->zErrMsg = sqlite3MPrintf(db, "%s", sqlite3ErrStr(pParse->rc));

  154622.   }

  154623.   assert( pzErrMsg!=0 );

  154624.   if( pParse->zErrMsg ){

  154625.     *pzErrMsg = pParse->zErrMsg;

  154626.     sqlite3_log(pParse->rc, "%s in \"%s\"", 

  154627.                 *pzErrMsg, pParse->zTail);

  154628.     pParse->zErrMsg = 0;

  154629.     nErr++;

  154630.   }

  154631.   pParse->zTail = zSql;

  154632.   if( pParse->pVdbe && pParse->nErr>0 && pParse->nested==0 ){

  154633.     sqlite3VdbeDelete(pParse->pVdbe);

  154634.     pParse->pVdbe = 0;

  154635.   }

  154636. #ifndef SQLITE_OMIT_SHARED_CACHE

  154637.   if( pParse->nested==0 ){

  154638.     sqlite3DbFree(db, pParse->aTableLock);

  154639.     pParse->aTableLock = 0;

  154640.     pParse->nTableLock = 0;

  154641.   }

  154642. #endif

  154643. #ifndef SQLITE_OMIT_VIRTUALTABLE

  154644.   sqlite3_free(pParse->apVtabLock);

  154645. #endif

  154646. 

  154647.   if( !IN_SPECIAL_PARSE ){

  154648.     /* If the pParse->declareVtab flag is set, do not delete any table 

  154649.     ** structure built up in pParse->pNewTable. The calling code (see vtab.c)

  154650.     ** will take responsibility for freeing the Table structure.

  154651.     */

  154652.     sqlite3DeleteTable(db, pParse->pNewTable);

  154653.   }

  154654.   if( !IN_RENAME_OBJECT ){

  154655.     sqlite3DeleteTrigger(db, pParse->pNewTrigger);

  154656.   }

  154657. 

  154658.   if( pParse->pWithToFree ) sqlite3WithDelete(db, pParse->pWithToFree);

  154659.   sqlite3DbFree(db, pParse->pVList);

  154660.   while( pParse->pAinc ){

  154661.     AutoincInfo *p = pParse->pAinc;

  154662.     pParse->pAinc = p->pNext;

  154663.     sqlite3DbFreeNN(db, p);

  154664.   }

  154665.   while( pParse->pZombieTab ){

  154666.     Table *p = pParse->pZombieTab;

  154667.     pParse->pZombieTab = p->pNextZombie;

  154668.     sqlite3DeleteTable(db, p);

  154669.   }

  154670.   db->pParse = pParse->pParentParse;

  154671.   pParse->pParentParse = 0;

  154672.   assert( nErr==0 || pParse->rc!=SQLITE_OK );

  154673.   return nErr;

  154674. }

  154675. 

  154676. 

  154677. #ifdef SQLITE_ENABLE_NORMALIZE

  154678. /*

  154679. ** Insert a single space character into pStr if the current string

  154680. ** ends with an identifier

  154681. */

  154682. static void addSpaceSeparator(sqlite3_str *pStr){

  154683.   if( pStr->nChar && sqlite3IsIdChar(pStr->zText[pStr->nChar-1]) ){

  154684.     sqlite3_str_append(pStr, " ", 1);

  154685.   }

  154686. }

  154687. 

  154688. /*

  154689. ** Compute a normalization of the SQL given by zSql[0..nSql-1].  Return

  154690. ** the normalization in space obtained from sqlite3DbMalloc().  Or return

  154691. ** NULL if anything goes wrong or if zSql is NULL.

  154692. */

  154693. SQLITE_PRIVATE char *sqlite3Normalize(

  154694.   Vdbe *pVdbe,       /* VM being reprepared */

  154695.   const char *zSql   /* The original SQL string */

  154696. ){

  154697.   sqlite3 *db;       /* The database connection */

  154698.   int i;             /* Next unread byte of zSql[] */

  154699.   int n;             /* length of current token */

  154700.   int tokenType;     /* type of current token */

  154701.   int prevType = 0;  /* Previous non-whitespace token */

  154702.   int nParen;        /* Number of nested levels of parentheses */

  154703.   int iStartIN;      /* Start of RHS of IN operator in z[] */

  154704.   int nParenAtIN;    /* Value of nParent at start of RHS of IN operator */

  154705.   int j;             /* Bytes of normalized SQL generated so far */

  154706.   sqlite3_str *pStr; /* The normalized SQL string under construction */

  154707. 

  154708.   db = sqlite3VdbeDb(pVdbe);

  154709.   tokenType = -1;

  154710.   nParen = iStartIN = nParenAtIN = 0;

  154711.   pStr = sqlite3_str_new(db);

  154712.   assert( pStr!=0 );  /* sqlite3_str_new() never returns NULL */

  154713.   for(i=0; zSql[i] && pStr->accError==0; i+=n){

  154714.     if( tokenType!=TK_SPACE ){

  154715.       prevType = tokenType;

  154716.     }

  154717.     n = sqlite3GetToken((unsigned char*)zSql+i, &tokenType);

  154718.     if( NEVER(n<=0) ) break;

  154719.     switch( tokenType ){

  154720.       case TK_SPACE: {

  154721.         break;

  154722.       }

  154723.       case TK_NULL: {

  154724.         if( prevType==TK_IS || prevType==TK_NOT ){

  154725.           sqlite3_str_append(pStr, " NULL", 5);

  154726.           break;

  154727.         }

  154728.         /* Fall through */

  154729.       }

  154730.       case TK_STRING:

  154731.       case TK_INTEGER:

  154732.       case TK_FLOAT:

  154733.       case TK_VARIABLE:

  154734.       case TK_BLOB: {

  154735.         sqlite3_str_append(pStr, "?", 1);

  154736.         break;

  154737.       }

  154738.       case TK_LP: {

  154739.         nParen++;

  154740.         if( prevType==TK_IN ){

  154741.           iStartIN = pStr->nChar;

  154742.           nParenAtIN = nParen;

  154743.         }

  154744.         sqlite3_str_append(pStr, "(", 1);

  154745.         break;

  154746.       }

  154747.       case TK_RP: {

  154748.         if( iStartIN>0 && nParen==nParenAtIN ){

  154749.           assert( pStr->nChar>=iStartIN );

  154750.           pStr->nChar = iStartIN+1;

  154751.           sqlite3_str_append(pStr, "?,?,?", 5);

  154752.           iStartIN = 0;

  154753.         }

  154754.         nParen--;

  154755.         sqlite3_str_append(pStr, ")", 1);

  154756.         break;

  154757.       }

  154758.       case TK_ID: {

  154759.         iStartIN = 0;

  154760.         j = pStr->nChar;

  154761.         if( sqlite3Isquote(zSql[i]) ){

  154762.           char *zId = sqlite3DbStrNDup(db, zSql+i, n);

  154763.           int nId;

  154764.           int eType = 0;

  154765.           if( zId==0 ) break;

  154766.           sqlite3Dequote(zId);

  154767.           if( zSql[i]=='"' && sqlite3VdbeUsesDoubleQuotedString(pVdbe, zId) ){

  154768.             sqlite3_str_append(pStr, "?", 1);

  154769.             sqlite3DbFree(db, zId);

  154770.             break;

  154771.           }

  154772.           nId = sqlite3Strlen30(zId);

  154773.           if( sqlite3GetToken((u8*)zId, &eType)==nId && eType==TK_ID ){

  154774.             addSpaceSeparator(pStr);

  154775.             sqlite3_str_append(pStr, zId, nId);

  154776.           }else{

  154777.             sqlite3_str_appendf(pStr, "\"%w\"", zId);

  154778.           }

  154779.           sqlite3DbFree(db, zId);

  154780.         }else{

  154781.           addSpaceSeparator(pStr);

  154782.           sqlite3_str_append(pStr, zSql+i, n);

  154783.         }

  154784.         while( j<pStr->nChar ){

  154785.           pStr->zText[j] = sqlite3Tolower(pStr->zText[j]);

  154786.           j++;

  154787.         }

  154788.         break;

  154789.       }

  154790.       case TK_SELECT: {

  154791.         iStartIN = 0;

  154792.         /* fall through */

  154793.       }

  154794.       default: {

  154795.         if( sqlite3IsIdChar(zSql[i]) ) addSpaceSeparator(pStr);

  154796.         j = pStr->nChar;

  154797.         sqlite3_str_append(pStr, zSql+i, n);

  154798.         while( j<pStr->nChar ){

  154799.           pStr->zText[j] = sqlite3Toupper(pStr->zText[j]);

  154800.           j++;

  154801.         }

  154802.         break;

  154803.       }

  154804.     }

  154805.   }

  154806.   if( tokenType!=TK_SEMI ) sqlite3_str_append(pStr, ";", 1);

  154807.   return sqlite3_str_finish(pStr);

  154808. }

  154809. #endif /* SQLITE_ENABLE_NORMALIZE */

  154810. 

  154811. /************** End of tokenize.c ********************************************/

  154812. /************** Begin file complete.c ****************************************/

  154813. /*

  154814. ** 2001 September 15

  154815. **

  154816. ** The author disclaims copyright to this source code.  In place of

  154817. ** a legal notice, here is a blessing:

  154818. **

  154819. **    May you do good and not evil.

  154820. **    May you find forgiveness for yourself and forgive others.

  154821. **    May you share freely, never taking more than you give.

  154822. **

  154823. *************************************************************************

  154824. ** An tokenizer for SQL

  154825. **

  154826. ** This file contains C code that implements the sqlite3_complete() API.

  154827. ** This code used to be part of the tokenizer.c source file.  But by

  154828. ** separating it out, the code will be automatically omitted from

  154829. ** static links that do not use it.

  154830. */

  154831. /* #include "sqliteInt.h" */

  154832. #ifndef SQLITE_OMIT_COMPLETE

  154833. 

  154834. /*

  154835. ** This is defined in tokenize.c.  We just have to import the definition.

  154836. */

  154837. #ifndef SQLITE_AMALGAMATION

  154838. #ifdef SQLITE_ASCII

  154839. #define IdChar(C)  ((sqlite3CtypeMap[(unsigned char)C]&0x46)!=0)

  154840. #endif

  154841. #ifdef SQLITE_EBCDIC

  154842. SQLITE_PRIVATE const char sqlite3IsEbcdicIdChar[];

  154843. #define IdChar(C)  (((c=C)>=0x42 && sqlite3IsEbcdicIdChar[c-0x40]))

  154844. #endif

  154845. #endif /* SQLITE_AMALGAMATION */

  154846. 

  154847. 

  154848. /*

  154849. ** Token types used by the sqlite3_complete() routine.  See the header

  154850. ** comments on that procedure for additional information.

  154851. */

  154852. #define tkSEMI    0

  154853. #define tkWS      1

  154854. #define tkOTHER   2

  154855. #ifndef SQLITE_OMIT_TRIGGER

  154856. #define tkEXPLAIN 3

  154857. #define tkCREATE  4

  154858. #define tkTEMP    5

  154859. #define tkTRIGGER 6

  154860. #define tkEND     7

  154861. #endif

  154862. 

  154863. /*

  154864. ** Return TRUE if the given SQL string ends in a semicolon.

  154865. **

  154866. ** Special handling is require for CREATE TRIGGER statements.

  154867. ** Whenever the CREATE TRIGGER keywords are seen, the statement

  154868. ** must end with ";END;".

  154869. **

  154870. ** This implementation uses a state machine with 8 states:

  154871. **

  154872. **   (0) INVALID   We have not yet seen a non-whitespace character.

  154873. **

  154874. **   (1) START     At the beginning or end of an SQL statement.  This routine

  154875. **                 returns 1 if it ends in the START state and 0 if it ends

  154876. **                 in any other state.

  154877. **

  154878. **   (2) NORMAL    We are in the middle of statement which ends with a single

  154879. **                 semicolon.

  154880. **

  154881. **   (3) EXPLAIN   The keyword EXPLAIN has been seen at the beginning of 

  154882. **                 a statement.

  154883. **

  154884. **   (4) CREATE    The keyword CREATE has been seen at the beginning of a

  154885. **                 statement, possibly preceded by EXPLAIN and/or followed by

  154886. **                 TEMP or TEMPORARY

  154887. **

  154888. **   (5) TRIGGER   We are in the middle of a trigger definition that must be

  154889. **                 ended by a semicolon, the keyword END, and another semicolon.

  154890. **

  154891. **   (6) SEMI      We've seen the first semicolon in the ";END;" that occurs at

  154892. **                 the end of a trigger definition.

  154893. **

  154894. **   (7) END       We've seen the ";END" of the ";END;" that occurs at the end

  154895. **                 of a trigger definition.

  154896. **

  154897. ** Transitions between states above are determined by tokens extracted

  154898. ** from the input.  The following tokens are significant:

  154899. **

  154900. **   (0) tkSEMI      A semicolon.

  154901. **   (1) tkWS        Whitespace.

  154902. **   (2) tkOTHER     Any other SQL token.

  154903. **   (3) tkEXPLAIN   The "explain" keyword.

  154904. **   (4) tkCREATE    The "create" keyword.

  154905. **   (5) tkTEMP      The "temp" or "temporary" keyword.

  154906. **   (6) tkTRIGGER   The "trigger" keyword.

  154907. **   (7) tkEND       The "end" keyword.

  154908. **

  154909. ** Whitespace never causes a state transition and is always ignored.

  154910. ** This means that a SQL string of all whitespace is invalid.

  154911. **

  154912. ** If we compile with SQLITE_OMIT_TRIGGER, all of the computation needed

  154913. ** to recognize the end of a trigger can be omitted.  All we have to do

  154914. ** is look for a semicolon that is not part of an string or comment.

  154915. */

  154916. SQLITE_API int sqlite3_complete(const char *zSql){

  154917.   u8 state = 0;   /* Current state, using numbers defined in header comment */

  154918.   u8 token;       /* Value of the next token */

  154919. 

  154920. #ifndef SQLITE_OMIT_TRIGGER

  154921.   /* A complex statement machine used to detect the end of a CREATE TRIGGER

  154922.   ** statement.  This is the normal case.

  154923.   */

  154924.   static const u8 trans[8][8] = {

  154925.                      /* Token:                                                */

  154926.      /* State:       **  SEMI  WS  OTHER  EXPLAIN  CREATE  TEMP  TRIGGER  END */

  154927.      /* 0 INVALID: */ {    1,  0,     2,       3,      4,    2,       2,   2, },

  154928.      /* 1   START: */ {    1,  1,     2,       3,      4,    2,       2,   2, },

  154929.      /* 2  NORMAL: */ {    1,  2,     2,       2,      2,    2,       2,   2, },

  154930.      /* 3 EXPLAIN: */ {    1,  3,     3,       2,      4,    2,       2,   2, },

  154931.      /* 4  CREATE: */ {    1,  4,     2,       2,      2,    4,       5,   2, },

  154932.      /* 5 TRIGGER: */ {    6,  5,     5,       5,      5,    5,       5,   5, },

  154933.      /* 6    SEMI: */ {    6,  6,     5,       5,      5,    5,       5,   7, },

  154934.      /* 7     END: */ {    1,  7,     5,       5,      5,    5,       5,   5, },

  154935.   };

  154936. #else

  154937.   /* If triggers are not supported by this compile then the statement machine

  154938.   ** used to detect the end of a statement is much simpler

  154939.   */

  154940.   static const u8 trans[3][3] = {

  154941.                      /* Token:           */

  154942.      /* State:       **  SEMI  WS  OTHER */

  154943.      /* 0 INVALID: */ {    1,  0,     2, },

  154944.      /* 1   START: */ {    1,  1,     2, },

  154945.      /* 2  NORMAL: */ {    1,  2,     2, },

  154946.   };

  154947. #endif /* SQLITE_OMIT_TRIGGER */

  154948. 

  154949. #ifdef SQLITE_ENABLE_API_ARMOR

  154950.   if( zSql==0 ){

  154951.     (void)SQLITE_MISUSE_BKPT;

  154952.     return 0;

  154953.   }

  154954. #endif

  154955. 

  154956.   while( *zSql ){

  154957.     switch( *zSql ){

  154958.       case ';': {  /* A semicolon */

  154959.         token = tkSEMI;

  154960.         break;

  154961.       }

  154962.       case ' ':

  154963.       case '\r':

  154964.       case '\t':

  154965.       case '\n':

  154966.       case '\f': {  /* White space is ignored */

  154967.         token = tkWS;

  154968.         break;

  154969.       }

  154970.       case '/': {   /* C-style comments */

  154971.         if( zSql[1]!='*' ){

  154972.           token = tkOTHER;

  154973.           break;

  154974.         }

  154975.         zSql += 2;

  154976.         while( zSql[0] && (zSql[0]!='*' || zSql[1]!='/') ){ zSql++; }

  154977.         if( zSql[0]==0 ) return 0;

  154978.         zSql++;

  154979.         token = tkWS;

  154980.         break;

  154981.       }

  154982.       case '-': {   /* SQL-style comments from "--" to end of line */

  154983.         if( zSql[1]!='-' ){

  154984.           token = tkOTHER;

  154985.           break;

  154986.         }

  154987.         while( *zSql && *zSql!='\n' ){ zSql++; }

  154988.         if( *zSql==0 ) return state==1;

  154989.         token = tkWS;

  154990.         break;

  154991.       }

  154992.       case '[': {   /* Microsoft-style identifiers in [...] */

  154993.         zSql++;

  154994.         while( *zSql && *zSql!=']' ){ zSql++; }

  154995.         if( *zSql==0 ) return 0;

  154996.         token = tkOTHER;

  154997.         break;

  154998.       }

  154999.       case '`':     /* Grave-accent quoted symbols used by MySQL */

  155000.       case '"':     /* single- and double-quoted strings */

  155001.       case '\'': {

  155002.         int c = *zSql;

  155003.         zSql++;

  155004.         while( *zSql && *zSql!=c ){ zSql++; }

  155005.         if( *zSql==0 ) return 0;

  155006.         token = tkOTHER;

  155007.         break;

  155008.       }

  155009.       default: {

  155010. #ifdef SQLITE_EBCDIC

  155011.         unsigned char c;

  155012. #endif

  155013.         if( IdChar((u8)*zSql) ){

  155014.           /* Keywords and unquoted identifiers */

  155015.           int nId;

  155016.           for(nId=1; IdChar(zSql[nId]); nId++){}

  155017. #ifdef SQLITE_OMIT_TRIGGER

  155018.           token = tkOTHER;

  155019. #else

  155020.           switch( *zSql ){

  155021.             case 'c': case 'C': {

  155022.               if( nId==6 && sqlite3StrNICmp(zSql, "create", 6)==0 ){

  155023.                 token = tkCREATE;

  155024.               }else{

  155025.                 token = tkOTHER;

  155026.               }

  155027.               break;

  155028.             }

  155029.             case 't': case 'T': {

  155030.               if( nId==7 && sqlite3StrNICmp(zSql, "trigger", 7)==0 ){

  155031.                 token = tkTRIGGER;

  155032.               }else if( nId==4 && sqlite3StrNICmp(zSql, "temp", 4)==0 ){

  155033.                 token = tkTEMP;

  155034.               }else if( nId==9 && sqlite3StrNICmp(zSql, "temporary", 9)==0 ){

  155035.                 token = tkTEMP;

  155036.               }else{

  155037.                 token = tkOTHER;

  155038.               }

  155039.               break;

  155040.             }

  155041.             case 'e':  case 'E': {

  155042.               if( nId==3 && sqlite3StrNICmp(zSql, "end", 3)==0 ){

  155043.                 token = tkEND;

  155044.               }else

  155045. #ifndef SQLITE_OMIT_EXPLAIN

  155046.               if( nId==7 && sqlite3StrNICmp(zSql, "explain", 7)==0 ){

  155047.                 token = tkEXPLAIN;

  155048.               }else

  155049. #endif

  155050.               {

  155051.                 token = tkOTHER;

  155052.               }

  155053.               break;

  155054.             }

  155055.             default: {

  155056.               token = tkOTHER;

  155057.               break;

  155058.             }

  155059.           }

  155060. #endif /* SQLITE_OMIT_TRIGGER */

  155061.           zSql += nId-1;

  155062.         }else{

  155063.           /* Operators and special symbols */

  155064.           token = tkOTHER;

  155065.         }

  155066.         break;

  155067.       }

  155068.     }

  155069.     state = trans[state][token];

  155070.     zSql++;

  155071.   }

  155072.   return state==1;

  155073. }

  155074. 

  155075. #ifndef SQLITE_OMIT_UTF16

  155076. /*

  155077. ** This routine is the same as the sqlite3_complete() routine described

  155078. ** above, except that the parameter is required to be UTF-16 encoded, not

  155079. ** UTF-8.

  155080. */

  155081. SQLITE_API int sqlite3_complete16(const void *zSql){

  155082.   sqlite3_value *pVal;

  155083.   char const *zSql8;

  155084.   int rc;

  155085. 

  155086. #ifndef SQLITE_OMIT_AUTOINIT

  155087.   rc = sqlite3_initialize();

  155088.   if( rc ) return rc;

  155089. #endif

  155090.   pVal = sqlite3ValueNew(0);

  155091.   sqlite3ValueSetStr(pVal, -1, zSql, SQLITE_UTF16NATIVE, SQLITE_STATIC);

  155092.   zSql8 = sqlite3ValueText(pVal, SQLITE_UTF8);

  155093.   if( zSql8 ){

  155094.     rc = sqlite3_complete(zSql8);

  155095.   }else{

  155096.     rc = SQLITE_NOMEM_BKPT;

  155097.   }

  155098.   sqlite3ValueFree(pVal);

  155099.   return rc & 0xff;

  155100. }

  155101. #endif /* SQLITE_OMIT_UTF16 */

  155102. #endif /* SQLITE_OMIT_COMPLETE */

  155103. 

  155104. /************** End of complete.c ********************************************/

  155105. /************** Begin file main.c ********************************************/

  155106. /*

  155107. ** 2001 September 15

  155108. **

  155109. ** The author disclaims copyright to this source code.  In place of

  155110. ** a legal notice, here is a blessing:

  155111. **

  155112. **    May you do good and not evil.

  155113. **    May you find forgiveness for yourself and forgive others.

  155114. **    May you share freely, never taking more than you give.

  155115. **

  155116. *************************************************************************

  155117. ** Main file for the SQLite library.  The routines in this file

  155118. ** implement the programmer interface to the library.  Routines in

  155119. ** other files are for internal use by SQLite and should not be

  155120. ** accessed by users of the library.

  155121. */

  155122. /* #include "sqliteInt.h" */

  155123. 

  155124. #ifdef SQLITE_ENABLE_FTS3

  155125. /************** Include fts3.h in the middle of main.c ***********************/

  155126. /************** Begin file fts3.h ********************************************/

  155127. /*

  155128. ** 2006 Oct 10

  155129. **

  155130. ** The author disclaims copyright to this source code.  In place of

  155131. ** a legal notice, here is a blessing:

  155132. **

  155133. **    May you do good and not evil.

  155134. **    May you find forgiveness for yourself and forgive others.

  155135. **    May you share freely, never taking more than you give.

  155136. **

  155137. ******************************************************************************

  155138. **

  155139. ** This header file is used by programs that want to link against the

  155140. ** FTS3 library.  All it does is declare the sqlite3Fts3Init() interface.

  155141. */

  155142. /* #include "sqlite3.h" */

  155143. 

  155144. #if 0

  155145. extern "C" {

  155146. #endif  /* __cplusplus */

  155147. 

  155148. SQLITE_PRIVATE int sqlite3Fts3Init(sqlite3 *db);

  155149. 

  155150. #if 0

  155151. }  /* extern "C" */

  155152. #endif  /* __cplusplus */

  155153. 

  155154. /************** End of fts3.h ************************************************/

  155155. /************** Continuing where we left off in main.c ***********************/

  155156. #endif

  155157. #ifdef SQLITE_ENABLE_RTREE

  155158. /************** Include rtree.h in the middle of main.c **********************/

  155159. /************** Begin file rtree.h *******************************************/

  155160. /*

  155161. ** 2008 May 26

  155162. **

  155163. ** The author disclaims copyright to this source code.  In place of

  155164. ** a legal notice, here is a blessing:

  155165. **

  155166. **    May you do good and not evil.

  155167. **    May you find forgiveness for yourself and forgive others.

  155168. **    May you share freely, never taking more than you give.

  155169. **

  155170. ******************************************************************************

  155171. **

  155172. ** This header file is used by programs that want to link against the

  155173. ** RTREE library.  All it does is declare the sqlite3RtreeInit() interface.

  155174. */

  155175. /* #include "sqlite3.h" */

  155176. 

  155177. #ifdef SQLITE_OMIT_VIRTUALTABLE

  155178. # undef SQLITE_ENABLE_RTREE

  155179. #endif

  155180. 

  155181. #if 0

  155182. extern "C" {

  155183. #endif  /* __cplusplus */

  155184. 

  155185. SQLITE_PRIVATE int sqlite3RtreeInit(sqlite3 *db);

  155186. 

  155187. #if 0

  155188. }  /* extern "C" */

  155189. #endif  /* __cplusplus */

  155190. 

  155191. /************** End of rtree.h ***********************************************/

  155192. /************** Continuing where we left off in main.c ***********************/

  155193. #endif

  155194. #if defined(SQLITE_ENABLE_ICU) || defined(SQLITE_ENABLE_ICU_COLLATIONS)

  155195. /************** Include sqliteicu.h in the middle of main.c ******************/

  155196. /************** Begin file sqliteicu.h ***************************************/

  155197. /*

  155198. ** 2008 May 26

  155199. **

  155200. ** The author disclaims copyright to this source code.  In place of

  155201. ** a legal notice, here is a blessing:

  155202. **

  155203. **    May you do good and not evil.

  155204. **    May you find forgiveness for yourself and forgive others.

  155205. **    May you share freely, never taking more than you give.

  155206. **

  155207. ******************************************************************************

  155208. **

  155209. ** This header file is used by programs that want to link against the

  155210. ** ICU extension.  All it does is declare the sqlite3IcuInit() interface.

  155211. */

  155212. /* #include "sqlite3.h" */

  155213. 

  155214. #if 0

  155215. extern "C" {

  155216. #endif  /* __cplusplus */

  155217. 

  155218. SQLITE_PRIVATE int sqlite3IcuInit(sqlite3 *db);

  155219. 

  155220. #if 0

  155221. }  /* extern "C" */

  155222. #endif  /* __cplusplus */

  155223. 

  155224. 

  155225. /************** End of sqliteicu.h *******************************************/

  155226. /************** Continuing where we left off in main.c ***********************/

  155227. #endif

  155228. #ifdef SQLITE_ENABLE_JSON1

  155229. SQLITE_PRIVATE int sqlite3Json1Init(sqlite3*);

  155230. #endif

  155231. #ifdef SQLITE_ENABLE_STMTVTAB

  155232. SQLITE_PRIVATE int sqlite3StmtVtabInit(sqlite3*);

  155233. #endif

  155234. #ifdef SQLITE_ENABLE_FTS5

  155235. SQLITE_PRIVATE int sqlite3Fts5Init(sqlite3*);

  155236. #endif

  155237. 

  155238. #ifndef SQLITE_AMALGAMATION

  155239. /* IMPLEMENTATION-OF: R-46656-45156 The sqlite3_version[] string constant

  155240. ** contains the text of SQLITE_VERSION macro. 

  155241. */

  155242. SQLITE_API const char sqlite3_version[] = SQLITE_VERSION;

  155243. #endif

  155244. 

  155245. /* IMPLEMENTATION-OF: R-53536-42575 The sqlite3_libversion() function returns

  155246. ** a pointer to the to the sqlite3_version[] string constant. 

  155247. */

  155248. SQLITE_API const char *sqlite3_libversion(void){ return sqlite3_version; }

  155249. 

  155250. /* IMPLEMENTATION-OF: R-25063-23286 The sqlite3_sourceid() function returns a

  155251. ** pointer to a string constant whose value is the same as the

  155252. ** SQLITE_SOURCE_ID C preprocessor macro. Except if SQLite is built using

  155253. ** an edited copy of the amalgamation, then the last four characters of

  155254. ** the hash might be different from SQLITE_SOURCE_ID.

  155255. */

  155256. /* SQLITE_API const char *sqlite3_sourceid(void){ return SQLITE_SOURCE_ID; } */

  155257. 

  155258. /* IMPLEMENTATION-OF: R-35210-63508 The sqlite3_libversion_number() function

  155259. ** returns an integer equal to SQLITE_VERSION_NUMBER.

  155260. */

  155261. SQLITE_API int sqlite3_libversion_number(void){ return SQLITE_VERSION_NUMBER; }

  155262. 

  155263. /* IMPLEMENTATION-OF: R-20790-14025 The sqlite3_threadsafe() function returns

  155264. ** zero if and only if SQLite was compiled with mutexing code omitted due to

  155265. ** the SQLITE_THREADSAFE compile-time option being set to 0.

  155266. */

  155267. SQLITE_API int sqlite3_threadsafe(void){ return SQLITE_THREADSAFE; }

  155268. 

  155269. /*

  155270. ** When compiling the test fixture or with debugging enabled (on Win32),

  155271. ** this variable being set to non-zero will cause OSTRACE macros to emit

  155272. ** extra diagnostic information.

  155273. */

  155274. #ifdef SQLITE_HAVE_OS_TRACE

  155275. # ifndef SQLITE_DEBUG_OS_TRACE

  155276. #   define SQLITE_DEBUG_OS_TRACE 0

  155277. # endif

  155278.   int sqlite3OSTrace = SQLITE_DEBUG_OS_TRACE;

  155279. #endif

  155280. 

  155281. #if !defined(SQLITE_OMIT_TRACE) && defined(SQLITE_ENABLE_IOTRACE)

  155282. /*

  155283. ** If the following function pointer is not NULL and if

  155284. ** SQLITE_ENABLE_IOTRACE is enabled, then messages describing

  155285. ** I/O active are written using this function.  These messages

  155286. ** are intended for debugging activity only.

  155287. */

  155288. SQLITE_API void (SQLITE_CDECL *sqlite3IoTrace)(const char*, ...) = 0;

  155289. #endif

  155290. 

  155291. /*

  155292. ** If the following global variable points to a string which is the

  155293. ** name of a directory, then that directory will be used to store

  155294. ** temporary files.

  155295. **

  155296. ** See also the "PRAGMA temp_store_directory" SQL command.

  155297. */

  155298. SQLITE_API char *sqlite3_temp_directory = 0;

  155299. 

  155300. /*

  155301. ** If the following global variable points to a string which is the

  155302. ** name of a directory, then that directory will be used to store

  155303. ** all database files specified with a relative pathname.

  155304. **

  155305. ** See also the "PRAGMA data_store_directory" SQL command.

  155306. */

  155307. SQLITE_API char *sqlite3_data_directory = 0;

  155308. 

  155309. /*

  155310. ** Initialize SQLite.  

  155311. **

  155312. ** This routine must be called to initialize the memory allocation,

  155313. ** VFS, and mutex subsystems prior to doing any serious work with

  155314. ** SQLite.  But as long as you do not compile with SQLITE_OMIT_AUTOINIT

  155315. ** this routine will be called automatically by key routines such as

  155316. ** sqlite3_open().  

  155317. **

  155318. ** This routine is a no-op except on its very first call for the process,

  155319. ** or for the first call after a call to sqlite3_shutdown.

  155320. **

  155321. ** The first thread to call this routine runs the initialization to

  155322. ** completion.  If subsequent threads call this routine before the first

  155323. ** thread has finished the initialization process, then the subsequent

  155324. ** threads must block until the first thread finishes with the initialization.

  155325. **

  155326. ** The first thread might call this routine recursively.  Recursive

  155327. ** calls to this routine should not block, of course.  Otherwise the

  155328. ** initialization process would never complete.

  155329. **

  155330. ** Let X be the first thread to enter this routine.  Let Y be some other

  155331. ** thread.  Then while the initial invocation of this routine by X is

  155332. ** incomplete, it is required that:

  155333. **

  155334. **    *  Calls to this routine from Y must block until the outer-most

  155335. **       call by X completes.

  155336. **

  155337. **    *  Recursive calls to this routine from thread X return immediately

  155338. **       without blocking.

  155339. */

  155340. SQLITE_API int sqlite3_initialize(void){

  155341.   MUTEX_LOGIC( sqlite3_mutex *pMaster; )       /* The main static mutex */

  155342.   int rc;                                      /* Result code */

  155343. #ifdef SQLITE_EXTRA_INIT

  155344.   int bRunExtraInit = 0;                       /* Extra initialization needed */

  155345. #endif

  155346. 

  155347. #ifdef SQLITE_OMIT_WSD

  155348.   rc = sqlite3_wsd_init(4096, 24);

  155349.   if( rc!=SQLITE_OK ){

  155350.     return rc;

  155351.   }

  155352. #endif

  155353. 

  155354.   /* If the following assert() fails on some obscure processor/compiler

  155355.   ** combination, the work-around is to set the correct pointer

  155356.   ** size at compile-time using -DSQLITE_PTRSIZE=n compile-time option */

  155357.   assert( SQLITE_PTRSIZE==sizeof(char*) );

  155358. 

  155359.   /* If SQLite is already completely initialized, then this call

  155360.   ** to sqlite3_initialize() should be a no-op.  But the initialization

  155361.   ** must be complete.  So isInit must not be set until the very end

  155362.   ** of this routine.

  155363.   */

  155364.   if( sqlite3GlobalConfig.isInit ) return SQLITE_OK;

  155365. 

  155366.   /* Make sure the mutex subsystem is initialized.  If unable to 

  155367.   ** initialize the mutex subsystem, return early with the error.

  155368.   ** If the system is so sick that we are unable to allocate a mutex,

  155369.   ** there is not much SQLite is going to be able to do.

  155370.   **

  155371.   ** The mutex subsystem must take care of serializing its own

  155372.   ** initialization.

  155373.   */

  155374.   rc = sqlite3MutexInit();

  155375.   if( rc ) return rc;

  155376. 

  155377.   /* Initialize the malloc() system and the recursive pInitMutex mutex.

  155378.   ** This operation is protected by the STATIC_MASTER mutex.  Note that

  155379.   ** MutexAlloc() is called for a static mutex prior to initializing the

  155380.   ** malloc subsystem - this implies that the allocation of a static

  155381.   ** mutex must not require support from the malloc subsystem.

  155382.   */

  155383.   MUTEX_LOGIC( pMaster = sqlite3MutexAlloc(SQLITE_MUTEX_STATIC_MASTER); )

  155384.   sqlite3_mutex_enter(pMaster);

  155385.   sqlite3GlobalConfig.isMutexInit = 1;

  155386.   if( !sqlite3GlobalConfig.isMallocInit ){

  155387.     rc = sqlite3MallocInit();

  155388.   }

  155389.   if( rc==SQLITE_OK ){

  155390.     sqlite3GlobalConfig.isMallocInit = 1;

  155391.     if( !sqlite3GlobalConfig.pInitMutex ){

  155392.       sqlite3GlobalConfig.pInitMutex =

  155393.            sqlite3MutexAlloc(SQLITE_MUTEX_RECURSIVE);

  155394.       if( sqlite3GlobalConfig.bCoreMutex && !sqlite3GlobalConfig.pInitMutex ){

  155395.         rc = SQLITE_NOMEM_BKPT;

  155396.       }

  155397.     }

  155398.   }

  155399.   if( rc==SQLITE_OK ){

  155400.     sqlite3GlobalConfig.nRefInitMutex++;

  155401.   }

  155402.   sqlite3_mutex_leave(pMaster);

  155403. 

  155404.   /* If rc is not SQLITE_OK at this point, then either the malloc

  155405.   ** subsystem could not be initialized or the system failed to allocate

  155406.   ** the pInitMutex mutex. Return an error in either case.  */

  155407.   if( rc!=SQLITE_OK ){

  155408.     return rc;

  155409.   }

  155410. 

  155411.   /* Do the rest of the initialization under the recursive mutex so

  155412.   ** that we will be able to handle recursive calls into

  155413.   ** sqlite3_initialize().  The recursive calls normally come through

  155414.   ** sqlite3_os_init() when it invokes sqlite3_vfs_register(), but other

  155415.   ** recursive calls might also be possible.

  155416.   **

  155417.   ** IMPLEMENTATION-OF: R-00140-37445 SQLite automatically serializes calls

  155418.   ** to the xInit method, so the xInit method need not be threadsafe.

  155419.   **

  155420.   ** The following mutex is what serializes access to the appdef pcache xInit

  155421.   ** methods.  The sqlite3_pcache_methods.xInit() all is embedded in the

  155422.   ** call to sqlite3PcacheInitialize().

  155423.   */

  155424.   sqlite3_mutex_enter(sqlite3GlobalConfig.pInitMutex);

  155425.   if( sqlite3GlobalConfig.isInit==0 && sqlite3GlobalConfig.inProgress==0 ){

  155426.     sqlite3GlobalConfig.inProgress = 1;

  155427. #ifdef SQLITE_ENABLE_SQLLOG

  155428.     {

  155429.       extern void sqlite3_init_sqllog(void);

  155430.       sqlite3_init_sqllog();

  155431.     }

  155432. #endif

  155433.     memset(&sqlite3BuiltinFunctions, 0, sizeof(sqlite3BuiltinFunctions));

  155434.     sqlite3RegisterBuiltinFunctions();

  155435.     if( sqlite3GlobalConfig.isPCacheInit==0 ){

  155436.       rc = sqlite3PcacheInitialize();

  155437.     }

  155438.     if( rc==SQLITE_OK ){

  155439.       sqlite3GlobalConfig.isPCacheInit = 1;

  155440.       rc = sqlite3OsInit();

  155441.     }

  155442. #ifdef SQLITE_ENABLE_DESERIALIZE

  155443.     if( rc==SQLITE_OK ){

  155444.       rc = sqlite3MemdbInit();

  155445.     }

  155446. #endif

  155447.     if( rc==SQLITE_OK ){

  155448.       sqlite3PCacheBufferSetup( sqlite3GlobalConfig.pPage, 

  155449.           sqlite3GlobalConfig.szPage, sqlite3GlobalConfig.nPage);

  155450.       sqlite3GlobalConfig.isInit = 1;

  155451. #ifdef SQLITE_EXTRA_INIT

  155452.       bRunExtraInit = 1;

  155453. #endif

  155454.     }

  155455.     sqlite3GlobalConfig.inProgress = 0;

  155456.   }

  155457.   sqlite3_mutex_leave(sqlite3GlobalConfig.pInitMutex);

  155458. 

  155459.   /* Go back under the static mutex and clean up the recursive

  155460.   ** mutex to prevent a resource leak.

  155461.   */

  155462.   sqlite3_mutex_enter(pMaster);

  155463.   sqlite3GlobalConfig.nRefInitMutex--;

  155464.   if( sqlite3GlobalConfig.nRefInitMutex<=0 ){

  155465.     assert( sqlite3GlobalConfig.nRefInitMutex==0 );

  155466.     sqlite3_mutex_free(sqlite3GlobalConfig.pInitMutex);

  155467.     sqlite3GlobalConfig.pInitMutex = 0;

  155468.   }

  155469.   sqlite3_mutex_leave(pMaster);

  155470. 

  155471.   /* The following is just a sanity check to make sure SQLite has

  155472.   ** been compiled correctly.  It is important to run this code, but

  155473.   ** we don't want to run it too often and soak up CPU cycles for no

  155474.   ** reason.  So we run it once during initialization.

  155475.   */

  155476. #ifndef NDEBUG

  155477. #ifndef SQLITE_OMIT_FLOATING_POINT

  155478.   /* This section of code's only "output" is via assert() statements. */

  155479.   if( rc==SQLITE_OK ){

  155480.     u64 x = (((u64)1)<<63)-1;

  155481.     double y;

  155482.     assert(sizeof(x)==8);

  155483.     assert(sizeof(x)==sizeof(y));

  155484.     memcpy(&y, &x, 8);

  155485.     assert( sqlite3IsNaN(y) );

  155486.   }

  155487. #endif

  155488. #endif

  155489. 

  155490.   /* Do extra initialization steps requested by the SQLITE_EXTRA_INIT

  155491.   ** compile-time option.

  155492.   */

  155493. #ifdef SQLITE_EXTRA_INIT

  155494.   if( bRunExtraInit ){

  155495.     int SQLITE_EXTRA_INIT(const char*);

  155496.     rc = SQLITE_EXTRA_INIT(0);

  155497.   }

  155498. #endif

  155499. 

  155500.   return rc;

  155501. }

  155502. 

  155503. /*

  155504. ** Undo the effects of sqlite3_initialize().  Must not be called while

  155505. ** there are outstanding database connections or memory allocations or

  155506. ** while any part of SQLite is otherwise in use in any thread.  This

  155507. ** routine is not threadsafe.  But it is safe to invoke this routine

  155508. ** on when SQLite is already shut down.  If SQLite is already shut down

  155509. ** when this routine is invoked, then this routine is a harmless no-op.

  155510. */

  155511. SQLITE_API int sqlite3_shutdown(void){

  155512. #ifdef SQLITE_OMIT_WSD

  155513.   int rc = sqlite3_wsd_init(4096, 24);

  155514.   if( rc!=SQLITE_OK ){

  155515.     return rc;

  155516.   }

  155517. #endif

  155518. 

  155519.   if( sqlite3GlobalConfig.isInit ){

  155520. #ifdef SQLITE_EXTRA_SHUTDOWN

  155521.     void SQLITE_EXTRA_SHUTDOWN(void);

  155522.     SQLITE_EXTRA_SHUTDOWN();

  155523. #endif

  155524.     sqlite3_os_end();

  155525.     sqlite3_reset_auto_extension();

  155526.     sqlite3GlobalConfig.isInit = 0;

  155527.   }

  155528.   if( sqlite3GlobalConfig.isPCacheInit ){

  155529.     sqlite3PcacheShutdown();

  155530.     sqlite3GlobalConfig.isPCacheInit = 0;

  155531.   }

  155532.   if( sqlite3GlobalConfig.isMallocInit ){

  155533.     sqlite3MallocEnd();

  155534.     sqlite3GlobalConfig.isMallocInit = 0;

  155535. 

  155536. #ifndef SQLITE_OMIT_SHUTDOWN_DIRECTORIES

  155537.     /* The heap subsystem has now been shutdown and these values are supposed

  155538.     ** to be NULL or point to memory that was obtained from sqlite3_malloc(),

  155539.     ** which would rely on that heap subsystem; therefore, make sure these

  155540.     ** values cannot refer to heap memory that was just invalidated when the

  155541.     ** heap subsystem was shutdown.  This is only done if the current call to

  155542.     ** this function resulted in the heap subsystem actually being shutdown.

  155543.     */

  155544.     sqlite3_data_directory = 0;

  155545.     sqlite3_temp_directory = 0;

  155546. #endif

  155547.   }

  155548.   if( sqlite3GlobalConfig.isMutexInit ){

  155549.     sqlite3MutexEnd();

  155550.     sqlite3GlobalConfig.isMutexInit = 0;

  155551.   }

  155552. 

  155553.   return SQLITE_OK;

  155554. }

  155555. 

  155556. /*

  155557. ** This API allows applications to modify the global configuration of

  155558. ** the SQLite library at run-time.

  155559. **

  155560. ** This routine should only be called when there are no outstanding

  155561. ** database connections or memory allocations.  This routine is not

  155562. ** threadsafe.  Failure to heed these warnings can lead to unpredictable

  155563. ** behavior.

  155564. */

  155565. SQLITE_API int sqlite3_config(int op, ...){

  155566.   va_list ap;

  155567.   int rc = SQLITE_OK;

  155568. 

  155569.   /* sqlite3_config() shall return SQLITE_MISUSE if it is invoked while

  155570.   ** the SQLite library is in use. */

  155571.   if( sqlite3GlobalConfig.isInit ) return SQLITE_MISUSE_BKPT;

  155572. 

  155573.   va_start(ap, op);

  155574.   switch( op ){

  155575. 

  155576.     /* Mutex configuration options are only available in a threadsafe

  155577.     ** compile.

  155578.     */

  155579. #if defined(SQLITE_THREADSAFE) && SQLITE_THREADSAFE>0  /* IMP: R-54466-46756 */

  155580.     case SQLITE_CONFIG_SINGLETHREAD: {

  155581.       /* EVIDENCE-OF: R-02748-19096 This option sets the threading mode to

  155582.       ** Single-thread. */

  155583.       sqlite3GlobalConfig.bCoreMutex = 0;  /* Disable mutex on core */

  155584.       sqlite3GlobalConfig.bFullMutex = 0;  /* Disable mutex on connections */

  155585.       break;

  155586.     }

  155587. #endif

  155588. #if defined(SQLITE_THREADSAFE) && SQLITE_THREADSAFE>0 /* IMP: R-20520-54086 */

  155589.     case SQLITE_CONFIG_MULTITHREAD: {

  155590.       /* EVIDENCE-OF: R-14374-42468 This option sets the threading mode to

  155591.       ** Multi-thread. */

  155592.       sqlite3GlobalConfig.bCoreMutex = 1;  /* Enable mutex on core */

  155593.       sqlite3GlobalConfig.bFullMutex = 0;  /* Disable mutex on connections */

  155594.       break;

  155595.     }

  155596. #endif

  155597. #if defined(SQLITE_THREADSAFE) && SQLITE_THREADSAFE>0 /* IMP: R-59593-21810 */

  155598.     case SQLITE_CONFIG_SERIALIZED: {

  155599.       /* EVIDENCE-OF: R-41220-51800 This option sets the threading mode to

  155600.       ** Serialized. */

  155601.       sqlite3GlobalConfig.bCoreMutex = 1;  /* Enable mutex on core */

  155602.       sqlite3GlobalConfig.bFullMutex = 1;  /* Enable mutex on connections */

  155603.       break;

  155604.     }

  155605. #endif

  155606. #if defined(SQLITE_THREADSAFE) && SQLITE_THREADSAFE>0 /* IMP: R-63666-48755 */

  155607.     case SQLITE_CONFIG_MUTEX: {

  155608.       /* Specify an alternative mutex implementation */

  155609.       sqlite3GlobalConfig.mutex = *va_arg(ap, sqlite3_mutex_methods*);

  155610.       break;

  155611.     }

  155612. #endif

  155613. #if defined(SQLITE_THREADSAFE) && SQLITE_THREADSAFE>0 /* IMP: R-14450-37597 */

  155614.     case SQLITE_CONFIG_GETMUTEX: {

  155615.       /* Retrieve the current mutex implementation */

  155616.       *va_arg(ap, sqlite3_mutex_methods*) = sqlite3GlobalConfig.mutex;

  155617.       break;

  155618.     }

  155619. #endif

  155620. 

  155621.     case SQLITE_CONFIG_MALLOC: {

  155622.       /* EVIDENCE-OF: R-55594-21030 The SQLITE_CONFIG_MALLOC option takes a

  155623.       ** single argument which is a pointer to an instance of the

  155624.       ** sqlite3_mem_methods structure. The argument specifies alternative

  155625.       ** low-level memory allocation routines to be used in place of the memory

  155626.       ** allocation routines built into SQLite. */

  155627.       sqlite3GlobalConfig.m = *va_arg(ap, sqlite3_mem_methods*);

  155628.       break;

  155629.     }

  155630.     case SQLITE_CONFIG_GETMALLOC: {

  155631.       /* EVIDENCE-OF: R-51213-46414 The SQLITE_CONFIG_GETMALLOC option takes a

  155632.       ** single argument which is a pointer to an instance of the

  155633.       ** sqlite3_mem_methods structure. The sqlite3_mem_methods structure is

  155634.       ** filled with the currently defined memory allocation routines. */

  155635.       if( sqlite3GlobalConfig.m.xMalloc==0 ) sqlite3MemSetDefault();

  155636.       *va_arg(ap, sqlite3_mem_methods*) = sqlite3GlobalConfig.m;

  155637.       break;

  155638.     }

  155639.     case SQLITE_CONFIG_MEMSTATUS: {

  155640.       /* EVIDENCE-OF: R-61275-35157 The SQLITE_CONFIG_MEMSTATUS option takes

  155641.       ** single argument of type int, interpreted as a boolean, which enables

  155642.       ** or disables the collection of memory allocation statistics. */

  155643.       sqlite3GlobalConfig.bMemstat = va_arg(ap, int);

  155644.       break;

  155645.     }

  155646.     case SQLITE_CONFIG_SMALL_MALLOC: {

  155647.       sqlite3GlobalConfig.bSmallMalloc = va_arg(ap, int);

  155648.       break;

  155649.     }

  155650.     case SQLITE_CONFIG_PAGECACHE: {

  155651.       /* EVIDENCE-OF: R-18761-36601 There are three arguments to

  155652.       ** SQLITE_CONFIG_PAGECACHE: A pointer to 8-byte aligned memory (pMem),

  155653.       ** the size of each page cache line (sz), and the number of cache lines

  155654.       ** (N). */

  155655.       sqlite3GlobalConfig.pPage = va_arg(ap, void*);

  155656.       sqlite3GlobalConfig.szPage = va_arg(ap, int);

  155657.       sqlite3GlobalConfig.nPage = va_arg(ap, int);

  155658.       break;

  155659.     }

  155660.     case SQLITE_CONFIG_PCACHE_HDRSZ: {

  155661.       /* EVIDENCE-OF: R-39100-27317 The SQLITE_CONFIG_PCACHE_HDRSZ option takes

  155662.       ** a single parameter which is a pointer to an integer and writes into

  155663.       ** that integer the number of extra bytes per page required for each page

  155664.       ** in SQLITE_CONFIG_PAGECACHE. */

  155665.       *va_arg(ap, int*) = 

  155666.           sqlite3HeaderSizeBtree() +

  155667.           sqlite3HeaderSizePcache() +

  155668.           sqlite3HeaderSizePcache1();

  155669.       break;

  155670.     }

  155671. 

  155672.     case SQLITE_CONFIG_PCACHE: {

  155673.       /* no-op */

  155674.       break;

  155675.     }

  155676.     case SQLITE_CONFIG_GETPCACHE: {

  155677.       /* now an error */

  155678.       rc = SQLITE_ERROR;

  155679.       break;

  155680.     }

  155681. 

  155682.     case SQLITE_CONFIG_PCACHE2: {

  155683.       /* EVIDENCE-OF: R-63325-48378 The SQLITE_CONFIG_PCACHE2 option takes a

  155684.       ** single argument which is a pointer to an sqlite3_pcache_methods2

  155685.       ** object. This object specifies the interface to a custom page cache

  155686.       ** implementation. */

  155687.       sqlite3GlobalConfig.pcache2 = *va_arg(ap, sqlite3_pcache_methods2*);

  155688.       break;

  155689.     }

  155690.     case SQLITE_CONFIG_GETPCACHE2: {

  155691.       /* EVIDENCE-OF: R-22035-46182 The SQLITE_CONFIG_GETPCACHE2 option takes a

  155692.       ** single argument which is a pointer to an sqlite3_pcache_methods2

  155693.       ** object. SQLite copies of the current page cache implementation into

  155694.       ** that object. */

  155695.       if( sqlite3GlobalConfig.pcache2.xInit==0 ){

  155696.         sqlite3PCacheSetDefault();

  155697.       }

  155698.       *va_arg(ap, sqlite3_pcache_methods2*) = sqlite3GlobalConfig.pcache2;

  155699.       break;

  155700.     }

  155701. 

  155702. /* EVIDENCE-OF: R-06626-12911 The SQLITE_CONFIG_HEAP option is only

  155703. ** available if SQLite is compiled with either SQLITE_ENABLE_MEMSYS3 or

  155704. ** SQLITE_ENABLE_MEMSYS5 and returns SQLITE_ERROR if invoked otherwise. */

  155705. #if defined(SQLITE_ENABLE_MEMSYS3) || defined(SQLITE_ENABLE_MEMSYS5)

  155706.     case SQLITE_CONFIG_HEAP: {

  155707.       /* EVIDENCE-OF: R-19854-42126 There are three arguments to

  155708.       ** SQLITE_CONFIG_HEAP: An 8-byte aligned pointer to the memory, the

  155709.       ** number of bytes in the memory buffer, and the minimum allocation size.

  155710.       */

  155711.       sqlite3GlobalConfig.pHeap = va_arg(ap, void*);

  155712.       sqlite3GlobalConfig.nHeap = va_arg(ap, int);

  155713.       sqlite3GlobalConfig.mnReq = va_arg(ap, int);

  155714. 

  155715.       if( sqlite3GlobalConfig.mnReq<1 ){

  155716.         sqlite3GlobalConfig.mnReq = 1;

  155717.       }else if( sqlite3GlobalConfig.mnReq>(1<<12) ){

  155718.         /* cap min request size at 2^12 */

  155719.         sqlite3GlobalConfig.mnReq = (1<<12);

  155720.       }

  155721. 

  155722.       if( sqlite3GlobalConfig.pHeap==0 ){

  155723.         /* EVIDENCE-OF: R-49920-60189 If the first pointer (the memory pointer)

  155724.         ** is NULL, then SQLite reverts to using its default memory allocator

  155725.         ** (the system malloc() implementation), undoing any prior invocation of

  155726.         ** SQLITE_CONFIG_MALLOC.

  155727.         **

  155728.         ** Setting sqlite3GlobalConfig.m to all zeros will cause malloc to

  155729.         ** revert to its default implementation when sqlite3_initialize() is run

  155730.         */

  155731.         memset(&sqlite3GlobalConfig.m, 0, sizeof(sqlite3GlobalConfig.m));

  155732.       }else{

  155733.         /* EVIDENCE-OF: R-61006-08918 If the memory pointer is not NULL then the

  155734.         ** alternative memory allocator is engaged to handle all of SQLites

  155735.         ** memory allocation needs. */

  155736. #ifdef SQLITE_ENABLE_MEMSYS3

  155737.         sqlite3GlobalConfig.m = *sqlite3MemGetMemsys3();

  155738. #endif

  155739. #ifdef SQLITE_ENABLE_MEMSYS5

  155740.         sqlite3GlobalConfig.m = *sqlite3MemGetMemsys5();

  155741. #endif

  155742.       }

  155743.       break;

  155744.     }

  155745. #endif

  155746. 

  155747.     case SQLITE_CONFIG_LOOKASIDE: {

  155748.       sqlite3GlobalConfig.szLookaside = va_arg(ap, int);

  155749.       sqlite3GlobalConfig.nLookaside = va_arg(ap, int);

  155750.       break;

  155751.     }

  155752.     

  155753.     /* Record a pointer to the logger function and its first argument.

  155754.     ** The default is NULL.  Logging is disabled if the function pointer is

  155755.     ** NULL.

  155756.     */

  155757.     case SQLITE_CONFIG_LOG: {

  155758.       /* MSVC is picky about pulling func ptrs from va lists.

  155759.       ** http://support.microsoft.com/kb/47961

  155760.       ** sqlite3GlobalConfig.xLog = va_arg(ap, void(*)(void*,int,const char*));

  155761.       */

  155762.       typedef void(*LOGFUNC_t)(void*,int,const char*);

  155763.       sqlite3GlobalConfig.xLog = va_arg(ap, LOGFUNC_t);

  155764.       sqlite3GlobalConfig.pLogArg = va_arg(ap, void*);

  155765.       break;

  155766.     }

  155767. 

  155768.     /* EVIDENCE-OF: R-55548-33817 The compile-time setting for URI filenames

  155769.     ** can be changed at start-time using the

  155770.     ** sqlite3_config(SQLITE_CONFIG_URI,1) or

  155771.     ** sqlite3_config(SQLITE_CONFIG_URI,0) configuration calls.

  155772.     */

  155773.     case SQLITE_CONFIG_URI: {

  155774.       /* EVIDENCE-OF: R-25451-61125 The SQLITE_CONFIG_URI option takes a single

  155775.       ** argument of type int. If non-zero, then URI handling is globally

  155776.       ** enabled. If the parameter is zero, then URI handling is globally

  155777.       ** disabled. */

  155778.       sqlite3GlobalConfig.bOpenUri = va_arg(ap, int);

  155779.       break;

  155780.     }

  155781. 

  155782.     case SQLITE_CONFIG_COVERING_INDEX_SCAN: {

  155783.       /* EVIDENCE-OF: R-36592-02772 The SQLITE_CONFIG_COVERING_INDEX_SCAN

  155784.       ** option takes a single integer argument which is interpreted as a

  155785.       ** boolean in order to enable or disable the use of covering indices for

  155786.       ** full table scans in the query optimizer. */

  155787.       sqlite3GlobalConfig.bUseCis = va_arg(ap, int);

  155788.       break;

  155789.     }

  155790. 

  155791. #ifdef SQLITE_ENABLE_SQLLOG

  155792.     case SQLITE_CONFIG_SQLLOG: {

  155793.       typedef void(*SQLLOGFUNC_t)(void*, sqlite3*, const char*, int);

  155794.       sqlite3GlobalConfig.xSqllog = va_arg(ap, SQLLOGFUNC_t);

  155795.       sqlite3GlobalConfig.pSqllogArg = va_arg(ap, void *);

  155796.       break;

  155797.     }

  155798. #endif

  155799. 

  155800.     case SQLITE_CONFIG_MMAP_SIZE: {

  155801.       /* EVIDENCE-OF: R-58063-38258 SQLITE_CONFIG_MMAP_SIZE takes two 64-bit

  155802.       ** integer (sqlite3_int64) values that are the default mmap size limit

  155803.       ** (the default setting for PRAGMA mmap_size) and the maximum allowed

  155804.       ** mmap size limit. */

  155805.       sqlite3_int64 szMmap = va_arg(ap, sqlite3_int64);

  155806.       sqlite3_int64 mxMmap = va_arg(ap, sqlite3_int64);

  155807.       /* EVIDENCE-OF: R-53367-43190 If either argument to this option is

  155808.       ** negative, then that argument is changed to its compile-time default.

  155809.       **

  155810.       ** EVIDENCE-OF: R-34993-45031 The maximum allowed mmap size will be

  155811.       ** silently truncated if necessary so that it does not exceed the

  155812.       ** compile-time maximum mmap size set by the SQLITE_MAX_MMAP_SIZE

  155813.       ** compile-time option.

  155814.       */

  155815.       if( mxMmap<0 || mxMmap>SQLITE_MAX_MMAP_SIZE ){

  155816.         mxMmap = SQLITE_MAX_MMAP_SIZE;

  155817.       }

  155818.       if( szMmap<0 ) szMmap = SQLITE_DEFAULT_MMAP_SIZE;

  155819.       if( szMmap>mxMmap) szMmap = mxMmap;

  155820.       sqlite3GlobalConfig.mxMmap = mxMmap;

  155821.       sqlite3GlobalConfig.szMmap = szMmap;

  155822.       break;

  155823.     }

  155824. 

  155825. #if SQLITE_OS_WIN && defined(SQLITE_WIN32_MALLOC) /* IMP: R-04780-55815 */

  155826.     case SQLITE_CONFIG_WIN32_HEAPSIZE: {

  155827.       /* EVIDENCE-OF: R-34926-03360 SQLITE_CONFIG_WIN32_HEAPSIZE takes a 32-bit

  155828.       ** unsigned integer value that specifies the maximum size of the created

  155829.       ** heap. */

  155830.       sqlite3GlobalConfig.nHeap = va_arg(ap, int);

  155831.       break;

  155832.     }

  155833. #endif

  155834. 

  155835.     case SQLITE_CONFIG_PMASZ: {

  155836.       sqlite3GlobalConfig.szPma = va_arg(ap, unsigned int);

  155837.       break;

  155838.     }

  155839. 

  155840.     case SQLITE_CONFIG_STMTJRNL_SPILL: {

  155841.       sqlite3GlobalConfig.nStmtSpill = va_arg(ap, int);

  155842.       break;

  155843.     }

  155844. 

  155845. #ifdef SQLITE_ENABLE_SORTER_REFERENCES

  155846.     case SQLITE_CONFIG_SORTERREF_SIZE: {

  155847.       int iVal = va_arg(ap, int);

  155848.       if( iVal<0 ){

  155849.         iVal = SQLITE_DEFAULT_SORTERREF_SIZE;

  155850.       }

  155851.       sqlite3GlobalConfig.szSorterRef = (u32)iVal;

  155852.       break;

  155853.     }

  155854. #endif /* SQLITE_ENABLE_SORTER_REFERENCES */

  155855. 

  155856. #ifdef SQLITE_ENABLE_DESERIALIZE

  155857.     case SQLITE_CONFIG_MEMDB_MAXSIZE: {

  155858.       sqlite3GlobalConfig.mxMemdbSize = va_arg(ap, sqlite3_int64);

  155859.       break;

  155860.     }

  155861. #endif /* SQLITE_ENABLE_DESERIALIZE */

  155862. 

  155863.     default: {

  155864.       rc = SQLITE_ERROR;

  155865.       break;

  155866.     }

  155867.   }

  155868.   va_end(ap);

  155869.   return rc;

  155870. }

  155871. 

  155872. /*

  155873. ** Set up the lookaside buffers for a database connection.

  155874. ** Return SQLITE_OK on success.  

  155875. ** If lookaside is already active, return SQLITE_BUSY.

  155876. **

  155877. ** The sz parameter is the number of bytes in each lookaside slot.

  155878. ** The cnt parameter is the number of slots.  If pStart is NULL the

  155879. ** space for the lookaside memory is obtained from sqlite3_malloc().

  155880. ** If pStart is not NULL then it is sz*cnt bytes of memory to use for

  155881. ** the lookaside memory.

  155882. */

  155883. static int setupLookaside(sqlite3 *db, void *pBuf, int sz, int cnt){

  155884. #ifndef SQLITE_OMIT_LOOKASIDE

  155885.   void *pStart;

  155886.   

  155887.   if( sqlite3LookasideUsed(db,0)>0 ){

  155888.     return SQLITE_BUSY;

  155889.   }

  155890.   /* Free any existing lookaside buffer for this handle before

  155891.   ** allocating a new one so we don't have to have space for 

  155892.   ** both at the same time.

  155893.   */

  155894.   if( db->lookaside.bMalloced ){

  155895.     sqlite3_free(db->lookaside.pStart);

  155896.   }

  155897.   /* The size of a lookaside slot after ROUNDDOWN8 needs to be larger

  155898.   ** than a pointer to be useful.

  155899.   */

  155900.   sz = ROUNDDOWN8(sz);  /* IMP: R-33038-09382 */

  155901.   if( sz<=(int)sizeof(LookasideSlot*) ) sz = 0;

  155902.   if( cnt<0 ) cnt = 0;

  155903.   if( sz==0 || cnt==0 ){

  155904.     sz = 0;

  155905.     pStart = 0;

  155906.   }else if( pBuf==0 ){

  155907.     sqlite3BeginBenignMalloc();

  155908.     pStart = sqlite3Malloc( sz*(sqlite3_int64)cnt );  /* IMP: R-61949-35727 */

  155909.     sqlite3EndBenignMalloc();

  155910.     if( pStart ) cnt = sqlite3MallocSize(pStart)/sz;

  155911.   }else{

  155912.     pStart = pBuf;

  155913.   }

  155914.   db->lookaside.pStart = pStart;

  155915.   db->lookaside.pInit = 0;

  155916.   db->lookaside.pFree = 0;

  155917.   db->lookaside.sz = (u16)sz;

  155918.   if( pStart ){

  155919.     int i;

  155920.     LookasideSlot *p;

  155921.     assert( sz > (int)sizeof(LookasideSlot*) );

  155922.     db->lookaside.nSlot = cnt;

  155923.     p = (LookasideSlot*)pStart;

  155924.     for(i=cnt-1; i>=0; i--){

  155925.       p->pNext = db->lookaside.pInit;

  155926.       db->lookaside.pInit = p;

  155927.       p = (LookasideSlot*)&((u8*)p)[sz];

  155928.     }

  155929.     db->lookaside.pEnd = p;

  155930.     db->lookaside.bDisable = 0;

  155931.     db->lookaside.bMalloced = pBuf==0 ?1:0;

  155932.   }else{

  155933.     db->lookaside.pStart = db;

  155934.     db->lookaside.pEnd = db;

  155935.     db->lookaside.bDisable = 1;

  155936.     db->lookaside.bMalloced = 0;

  155937.     db->lookaside.nSlot = 0;

  155938.   }

  155939. #endif /* SQLITE_OMIT_LOOKASIDE */

  155940.   return SQLITE_OK;

  155941. }

  155942. 

  155943. /*

  155944. ** Return the mutex associated with a database connection.

  155945. */

  155946. SQLITE_API sqlite3_mutex *sqlite3_db_mutex(sqlite3 *db){

  155947. #ifdef SQLITE_ENABLE_API_ARMOR

  155948.   if( !sqlite3SafetyCheckOk(db) ){

  155949.     (void)SQLITE_MISUSE_BKPT;

  155950.     return 0;

  155951.   }

  155952. #endif

  155953.   return db->mutex;

  155954. }

  155955. 

  155956. /*

  155957. ** Free up as much memory as we can from the given database

  155958. ** connection.

  155959. */

  155960. SQLITE_API int sqlite3_db_release_memory(sqlite3 *db){

  155961.   int i;

  155962. 

  155963. #ifdef SQLITE_ENABLE_API_ARMOR

  155964.   if( !sqlite3SafetyCheckOk(db) ) return SQLITE_MISUSE_BKPT;

  155965. #endif

  155966.   sqlite3_mutex_enter(db->mutex);

  155967.   sqlite3BtreeEnterAll(db);

  155968.   for(i=0; i<db->nDb; i++){

  155969.     Btree *pBt = db->aDb[i].pBt;

  155970.     if( pBt ){

  155971.       Pager *pPager = sqlite3BtreePager(pBt);

  155972.       sqlite3PagerShrink(pPager);

  155973.     }

  155974.   }

  155975.   sqlite3BtreeLeaveAll(db);

  155976.   sqlite3_mutex_leave(db->mutex);

  155977.   return SQLITE_OK;

  155978. }

  155979. 

  155980. /*

  155981. ** Flush any dirty pages in the pager-cache for any attached database

  155982. ** to disk.

  155983. */

  155984. SQLITE_API int sqlite3_db_cacheflush(sqlite3 *db){

  155985.   int i;

  155986.   int rc = SQLITE_OK;

  155987.   int bSeenBusy = 0;

  155988. 

  155989. #ifdef SQLITE_ENABLE_API_ARMOR

  155990.   if( !sqlite3SafetyCheckOk(db) ) return SQLITE_MISUSE_BKPT;

  155991. #endif

  155992.   sqlite3_mutex_enter(db->mutex);

  155993.   sqlite3BtreeEnterAll(db);

  155994.   for(i=0; rc==SQLITE_OK && i<db->nDb; i++){

  155995.     Btree *pBt = db->aDb[i].pBt;

  155996.     if( pBt && sqlite3BtreeIsInTrans(pBt) ){

  155997.       Pager *pPager = sqlite3BtreePager(pBt);

  155998.       rc = sqlite3PagerFlush(pPager);

  155999.       if( rc==SQLITE_BUSY ){

  156000.         bSeenBusy = 1;

  156001.         rc = SQLITE_OK;

  156002.       }

  156003.     }

  156004.   }

  156005.   sqlite3BtreeLeaveAll(db);

  156006.   sqlite3_mutex_leave(db->mutex);

  156007.   return ((rc==SQLITE_OK && bSeenBusy) ? SQLITE_BUSY : rc);

  156008. }

  156009. 

  156010. /*

  156011. ** Configuration settings for an individual database connection

  156012. */

  156013. SQLITE_API int sqlite3_db_config(sqlite3 *db, int op, ...){

  156014.   va_list ap;

  156015.   int rc;

  156016.   va_start(ap, op);

  156017.   switch( op ){

  156018.     case SQLITE_DBCONFIG_MAINDBNAME: {

  156019.       /* IMP: R-06824-28531 */

  156020.       /* IMP: R-36257-52125 */

  156021.       db->aDb[0].zDbSName = va_arg(ap,char*);

  156022.       rc = SQLITE_OK;

  156023.       break;

  156024.     }

  156025.     case SQLITE_DBCONFIG_LOOKASIDE: {

  156026.       void *pBuf = va_arg(ap, void*); /* IMP: R-26835-10964 */

  156027.       int sz = va_arg(ap, int);       /* IMP: R-47871-25994 */

  156028.       int cnt = va_arg(ap, int);      /* IMP: R-04460-53386 */

  156029.       rc = setupLookaside(db, pBuf, sz, cnt);

  156030.       break;

  156031.     }

  156032.     default: {

  156033.       static const struct {

  156034.         int op;      /* The opcode */

  156035.         u32 mask;    /* Mask of the bit in sqlite3.flags to set/clear */

  156036.       } aFlagOp[] = {

  156037.         { SQLITE_DBCONFIG_ENABLE_FKEY,           SQLITE_ForeignKeys    },

  156038.         { SQLITE_DBCONFIG_ENABLE_TRIGGER,        SQLITE_EnableTrigger  },

  156039.         { SQLITE_DBCONFIG_ENABLE_FTS3_TOKENIZER, SQLITE_Fts3Tokenizer  },

  156040.         { SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION, SQLITE_LoadExtension  },

  156041.         { SQLITE_DBCONFIG_NO_CKPT_ON_CLOSE,      SQLITE_NoCkptOnClose  },

  156042.         { SQLITE_DBCONFIG_ENABLE_QPSG,           SQLITE_EnableQPSG     },

  156043.         { SQLITE_DBCONFIG_TRIGGER_EQP,           SQLITE_TriggerEQP     },

  156044.         { SQLITE_DBCONFIG_RESET_DATABASE,        SQLITE_ResetDatabase  },

  156045.         { SQLITE_DBCONFIG_DEFENSIVE,             SQLITE_Defensive      },

  156046.         { SQLITE_DBCONFIG_WRITABLE_SCHEMA,       SQLITE_WriteSchema|

  156047.                                                  SQLITE_NoSchemaError  },

  156048.         { SQLITE_DBCONFIG_LEGACY_ALTER_TABLE,    SQLITE_LegacyAlter    },

  156049.         { SQLITE_DBCONFIG_DQS_DDL,               SQLITE_DqsDDL         },

  156050.         { SQLITE_DBCONFIG_DQS_DML,               SQLITE_DqsDML         },

  156051.       };

  156052.       unsigned int i;

  156053.       rc = SQLITE_ERROR; /* IMP: R-42790-23372 */

  156054.       for(i=0; i<ArraySize(aFlagOp); i++){

  156055.         if( aFlagOp[i].op==op ){

  156056.           int onoff = va_arg(ap, int);

  156057.           int *pRes = va_arg(ap, int*);

  156058.           u64 oldFlags = db->flags;

  156059.           if( onoff>0 ){

  156060.             db->flags |= aFlagOp[i].mask;

  156061.           }else if( onoff==0 ){

  156062.             db->flags &= ~(u64)aFlagOp[i].mask;

  156063.           }

  156064.           if( oldFlags!=db->flags ){

  156065.             sqlite3ExpirePreparedStatements(db, 0);

  156066.           }

  156067.           if( pRes ){

  156068.             *pRes = (db->flags & aFlagOp[i].mask)!=0;

  156069.           }

  156070.           rc = SQLITE_OK;

  156071.           break;

  156072.         }

  156073.       }

  156074.       break;

  156075.     }

  156076.   }

  156077.   va_end(ap);

  156078.   return rc;

  156079. }

  156080. 

  156081. /*

  156082. ** This is the default collating function named "BINARY" which is always

  156083. ** available.

  156084. */

  156085. static int binCollFunc(

  156086.   void *NotUsed,

  156087.   int nKey1, const void *pKey1,

  156088.   int nKey2, const void *pKey2

  156089. ){

  156090.   int rc, n;

  156091.   UNUSED_PARAMETER(NotUsed);

  156092.   n = nKey1<nKey2 ? nKey1 : nKey2;

  156093.   /* EVIDENCE-OF: R-65033-28449 The built-in BINARY collation compares

  156094.   ** strings byte by byte using the memcmp() function from the standard C

  156095.   ** library. */

  156096.   assert( pKey1 && pKey2 );

  156097.   rc = memcmp(pKey1, pKey2, n);

  156098.   if( rc==0 ){

  156099.     rc = nKey1 - nKey2;

  156100.   }

  156101.   return rc;

  156102. }

  156103. 

  156104. /*

  156105. ** This is the collating function named "RTRIM" which is always

  156106. ** available.  Ignore trailing spaces.

  156107. */

  156108. static int rtrimCollFunc(

  156109.   void *pUser,

  156110.   int nKey1, const void *pKey1,

  156111.   int nKey2, const void *pKey2

  156112. ){

  156113.   const u8 *pK1 = (const u8*)pKey1;

  156114.   const u8 *pK2 = (const u8*)pKey2;

  156115.   while( nKey1 && pK1[nKey1-1]==' ' ) nKey1--;

  156116.   while( nKey2 && pK2[nKey2-1]==' ' ) nKey2--;

  156117.   return binCollFunc(pUser, nKey1, pKey1, nKey2, pKey2);

  156118. }

  156119. 

  156120. /*

  156121. ** Return true if CollSeq is the default built-in BINARY.

  156122. */

  156123. SQLITE_PRIVATE int sqlite3IsBinary(const CollSeq *p){

  156124.   assert( p==0 || p->xCmp!=binCollFunc || strcmp(p->zName,"BINARY")==0 );

  156125.   return p==0 || p->xCmp==binCollFunc;

  156126. }

  156127. 

  156128. /*

  156129. ** Another built-in collating sequence: NOCASE. 

  156130. **

  156131. ** This collating sequence is intended to be used for "case independent

  156132. ** comparison". SQLite's knowledge of upper and lower case equivalents

  156133. ** extends only to the 26 characters used in the English language.

  156134. **

  156135. ** At the moment there is only a UTF-8 implementation.

  156136. */

  156137. static int nocaseCollatingFunc(

  156138.   void *NotUsed,

  156139.   int nKey1, const void *pKey1,

  156140.   int nKey2, const void *pKey2

  156141. ){

  156142.   int r = sqlite3StrNICmp(

  156143.       (const char *)pKey1, (const char *)pKey2, (nKey1<nKey2)?nKey1:nKey2);

  156144.   UNUSED_PARAMETER(NotUsed);

  156145.   if( 0==r ){

  156146.     r = nKey1-nKey2;

  156147.   }

  156148.   return r;

  156149. }

  156150. 

  156151. /*

  156152. ** Return the ROWID of the most recent insert

  156153. */

  156154. SQLITE_API sqlite_int64 sqlite3_last_insert_rowid(sqlite3 *db){

  156155. #ifdef SQLITE_ENABLE_API_ARMOR

  156156.   if( !sqlite3SafetyCheckOk(db) ){

  156157.     (void)SQLITE_MISUSE_BKPT;

  156158.     return 0;

  156159.   }

  156160. #endif

  156161.   return db->lastRowid;

  156162. }

  156163. 

  156164. /*

  156165. ** Set the value returned by the sqlite3_last_insert_rowid() API function.

  156166. */

  156167. SQLITE_API void sqlite3_set_last_insert_rowid(sqlite3 *db, sqlite3_int64 iRowid){

  156168. #ifdef SQLITE_ENABLE_API_ARMOR

  156169.   if( !sqlite3SafetyCheckOk(db) ){

  156170.     (void)SQLITE_MISUSE_BKPT;

  156171.     return;

  156172.   }

  156173. #endif

  156174.   sqlite3_mutex_enter(db->mutex);

  156175.   db->lastRowid = iRowid;

  156176.   sqlite3_mutex_leave(db->mutex);

  156177. }

  156178. 

  156179. /*

  156180. ** Return the number of changes in the most recent call to sqlite3_exec().

  156181. */

  156182. SQLITE_API int sqlite3_changes(sqlite3 *db){

  156183. #ifdef SQLITE_ENABLE_API_ARMOR

  156184.   if( !sqlite3SafetyCheckOk(db) ){

  156185.     (void)SQLITE_MISUSE_BKPT;

  156186.     return 0;

  156187.   }

  156188. #endif

  156189.   return db->nChange;

  156190. }

  156191. 

  156192. /*

  156193. ** Return the number of changes since the database handle was opened.

  156194. */

  156195. SQLITE_API int sqlite3_total_changes(sqlite3 *db){

  156196. #ifdef SQLITE_ENABLE_API_ARMOR

  156197.   if( !sqlite3SafetyCheckOk(db) ){

  156198.     (void)SQLITE_MISUSE_BKPT;

  156199.     return 0;

  156200.   }

  156201. #endif

  156202.   return db->nTotalChange;

  156203. }

  156204. 

  156205. /*

  156206. ** Close all open savepoints. This function only manipulates fields of the

  156207. ** database handle object, it does not close any savepoints that may be open

  156208. ** at the b-tree/pager level.

  156209. */

  156210. SQLITE_PRIVATE void sqlite3CloseSavepoints(sqlite3 *db){

  156211.   while( db->pSavepoint ){

  156212.     Savepoint *pTmp = db->pSavepoint;

  156213.     db->pSavepoint = pTmp->pNext;

  156214.     sqlite3DbFree(db, pTmp);

  156215.   }

  156216.   db->nSavepoint = 0;

  156217.   db->nStatement = 0;

  156218.   db->isTransactionSavepoint = 0;

  156219. }

  156220. 

  156221. /*

  156222. ** Invoke the destructor function associated with FuncDef p, if any. Except,

  156223. ** if this is not the last copy of the function, do not invoke it. Multiple

  156224. ** copies of a single function are created when create_function() is called

  156225. ** with SQLITE_ANY as the encoding.

  156226. */

  156227. static void functionDestroy(sqlite3 *db, FuncDef *p){

  156228.   FuncDestructor *pDestructor = p->u.pDestructor;

  156229.   if( pDestructor ){

  156230.     pDestructor->nRef--;

  156231.     if( pDestructor->nRef==0 ){

  156232.       pDestructor->xDestroy(pDestructor->pUserData);

  156233.       sqlite3DbFree(db, pDestructor);

  156234.     }

  156235.   }

  156236. }

  156237. 

  156238. /*

  156239. ** Disconnect all sqlite3_vtab objects that belong to database connection

  156240. ** db. This is called when db is being closed.

  156241. */

  156242. static void disconnectAllVtab(sqlite3 *db){

  156243. #ifndef SQLITE_OMIT_VIRTUALTABLE

  156244.   int i;

  156245.   HashElem *p;

  156246.   sqlite3BtreeEnterAll(db);

  156247.   for(i=0; i<db->nDb; i++){

  156248.     Schema *pSchema = db->aDb[i].pSchema;

  156249.     if( pSchema ){

  156250.       for(p=sqliteHashFirst(&pSchema->tblHash); p; p=sqliteHashNext(p)){

  156251.         Table *pTab = (Table *)sqliteHashData(p);

  156252.         if( IsVirtual(pTab) ) sqlite3VtabDisconnect(db, pTab);

  156253.       }

  156254.     }

  156255.   }

  156256.   for(p=sqliteHashFirst(&db->aModule); p; p=sqliteHashNext(p)){

  156257.     Module *pMod = (Module *)sqliteHashData(p);

  156258.     if( pMod->pEpoTab ){

  156259.       sqlite3VtabDisconnect(db, pMod->pEpoTab);

  156260.     }

  156261.   }

  156262.   sqlite3VtabUnlockList(db);

  156263.   sqlite3BtreeLeaveAll(db);

  156264. #else

  156265.   UNUSED_PARAMETER(db);

  156266. #endif

  156267. }

  156268. 

  156269. /*

  156270. ** Return TRUE if database connection db has unfinalized prepared

  156271. ** statements or unfinished sqlite3_backup objects.  

  156272. */

  156273. static int connectionIsBusy(sqlite3 *db){

  156274.   int j;

  156275.   assert( sqlite3_mutex_held(db->mutex) );

  156276.   if( db->pVdbe ) return 1;

  156277.   for(j=0; j<db->nDb; j++){

  156278.     Btree *pBt = db->aDb[j].pBt;

  156279.     if( pBt && sqlite3BtreeIsInBackup(pBt) ) return 1;

  156280.   }

  156281.   return 0;

  156282. }

  156283. 

  156284. /*

  156285. ** Close an existing SQLite database

  156286. */

  156287. static int sqlite3Close(sqlite3 *db, int forceZombie){

  156288.   if( !db ){

  156289.     /* EVIDENCE-OF: R-63257-11740 Calling sqlite3_close() or

  156290.     ** sqlite3_close_v2() with a NULL pointer argument is a harmless no-op. */

  156291.     return SQLITE_OK;

  156292.   }

  156293.   if( !sqlite3SafetyCheckSickOrOk(db) ){

  156294.     return SQLITE_MISUSE_BKPT;

  156295.   }

  156296.   sqlite3_mutex_enter(db->mutex);

  156297.   if( db->mTrace & SQLITE_TRACE_CLOSE ){

  156298.     db->xTrace(SQLITE_TRACE_CLOSE, db->pTraceArg, db, 0);

  156299.   }

  156300. 

  156301.   /* Force xDisconnect calls on all virtual tables */

  156302.   disconnectAllVtab(db);

  156303. 

  156304.   /* If a transaction is open, the disconnectAllVtab() call above

  156305.   ** will not have called the xDisconnect() method on any virtual

  156306.   ** tables in the db->aVTrans[] array. The following sqlite3VtabRollback()

  156307.   ** call will do so. We need to do this before the check for active

  156308.   ** SQL statements below, as the v-table implementation may be storing

  156309.   ** some prepared statements internally.

  156310.   */

  156311.   sqlite3VtabRollback(db);

  156312. 

  156313.   /* Legacy behavior (sqlite3_close() behavior) is to return

  156314.   ** SQLITE_BUSY if the connection can not be closed immediately.

  156315.   */

  156316.   if( !forceZombie && connectionIsBusy(db) ){

  156317.     sqlite3ErrorWithMsg(db, SQLITE_BUSY, "unable to close due to unfinalized "

  156318.        "statements or unfinished backups");

  156319.     sqlite3_mutex_leave(db->mutex);

  156320.     return SQLITE_BUSY;

  156321.   }

  156322. 

  156323. #ifdef SQLITE_ENABLE_SQLLOG

  156324.   if( sqlite3GlobalConfig.xSqllog ){

  156325.     /* Closing the handle. Fourth parameter is passed the value 2. */

  156326.     sqlite3GlobalConfig.xSqllog(sqlite3GlobalConfig.pSqllogArg, db, 0, 2);

  156327.   }

  156328. #endif

  156329. 

  156330.   /* Convert the connection into a zombie and then close it.

  156331.   */

  156332.   db->magic = SQLITE_MAGIC_ZOMBIE;

  156333.   sqlite3LeaveMutexAndCloseZombie(db);

  156334.   return SQLITE_OK;

  156335. }

  156336. 

  156337. /*

  156338. ** Two variations on the public interface for closing a database

  156339. ** connection. The sqlite3_close() version returns SQLITE_BUSY and

  156340. ** leaves the connection option if there are unfinalized prepared

  156341. ** statements or unfinished sqlite3_backups.  The sqlite3_close_v2()

  156342. ** version forces the connection to become a zombie if there are

  156343. ** unclosed resources, and arranges for deallocation when the last

  156344. ** prepare statement or sqlite3_backup closes.

  156345. */

  156346. SQLITE_API int sqlite3_close(sqlite3 *db){ return sqlite3Close(db,0); }

  156347. SQLITE_API int sqlite3_close_v2(sqlite3 *db){ return sqlite3Close(db,1); }

  156348. 

  156349. 

  156350. /*

  156351. ** Close the mutex on database connection db.

  156352. **

  156353. ** Furthermore, if database connection db is a zombie (meaning that there

  156354. ** has been a prior call to sqlite3_close(db) or sqlite3_close_v2(db)) and

  156355. ** every sqlite3_stmt has now been finalized and every sqlite3_backup has

  156356. ** finished, then free all resources.

  156357. */

  156358. SQLITE_PRIVATE void sqlite3LeaveMutexAndCloseZombie(sqlite3 *db){

  156359.   HashElem *i;                    /* Hash table iterator */

  156360.   int j;

  156361. 

  156362.   /* If there are outstanding sqlite3_stmt or sqlite3_backup objects

  156363.   ** or if the connection has not yet been closed by sqlite3_close_v2(),

  156364.   ** then just leave the mutex and return.

  156365.   */

  156366.   if( db->magic!=SQLITE_MAGIC_ZOMBIE || connectionIsBusy(db) ){

  156367.     sqlite3_mutex_leave(db->mutex);

  156368.     return;

  156369.   }

  156370. 

  156371.   /* If we reach this point, it means that the database connection has

  156372.   ** closed all sqlite3_stmt and sqlite3_backup objects and has been

  156373.   ** passed to sqlite3_close (meaning that it is a zombie).  Therefore,

  156374.   ** go ahead and free all resources.

  156375.   */

  156376. 

  156377.   /* If a transaction is open, roll it back. This also ensures that if

  156378.   ** any database schemas have been modified by an uncommitted transaction

  156379.   ** they are reset. And that the required b-tree mutex is held to make

  156380.   ** the pager rollback and schema reset an atomic operation. */

  156381.   sqlite3RollbackAll(db, SQLITE_OK);

  156382. 

  156383.   /* Free any outstanding Savepoint structures. */

  156384.   sqlite3CloseSavepoints(db);

  156385. 

  156386.   /* Close all database connections */

  156387.   for(j=0; j<db->nDb; j++){

  156388.     struct Db *pDb = &db->aDb[j];

  156389.     if( pDb->pBt ){

  156390.       sqlite3BtreeClose(pDb->pBt);

  156391.       pDb->pBt = 0;

  156392.       if( j!=1 ){

  156393.         pDb->pSchema = 0;

  156394.       }

  156395.     }

  156396.   }

  156397.   /* Clear the TEMP schema separately and last */

  156398.   if( db->aDb[1].pSchema ){

  156399.     sqlite3SchemaClear(db->aDb[1].pSchema);

  156400.   }

  156401.   sqlite3VtabUnlockList(db);

  156402. 

  156403.   /* Free up the array of auxiliary databases */

  156404.   sqlite3CollapseDatabaseArray(db);

  156405.   assert( db->nDb<=2 );

  156406.   assert( db->aDb==db->aDbStatic );

  156407. 

  156408.   /* Tell the code in notify.c that the connection no longer holds any

  156409.   ** locks and does not require any further unlock-notify callbacks.

  156410.   */

  156411.   sqlite3ConnectionClosed(db);

  156412. 

  156413.   for(i=sqliteHashFirst(&db->aFunc); i; i=sqliteHashNext(i)){

  156414.     FuncDef *pNext, *p;

  156415.     p = sqliteHashData(i);

  156416.     do{

  156417.       functionDestroy(db, p);

  156418.       pNext = p->pNext;

  156419.       sqlite3DbFree(db, p);

  156420.       p = pNext;

  156421.     }while( p );

  156422.   }

  156423.   sqlite3HashClear(&db->aFunc);

  156424.   for(i=sqliteHashFirst(&db->aCollSeq); i; i=sqliteHashNext(i)){

  156425.     CollSeq *pColl = (CollSeq *)sqliteHashData(i);

  156426.     /* Invoke any destructors registered for collation sequence user data. */

  156427.     for(j=0; j<3; j++){

  156428.       if( pColl[j].xDel ){

  156429.         pColl[j].xDel(pColl[j].pUser);

  156430.       }

  156431.     }

  156432.     sqlite3DbFree(db, pColl);

  156433.   }

  156434.   sqlite3HashClear(&db->aCollSeq);

  156435. #ifndef SQLITE_OMIT_VIRTUALTABLE

  156436.   for(i=sqliteHashFirst(&db->aModule); i; i=sqliteHashNext(i)){

  156437.     Module *pMod = (Module *)sqliteHashData(i);

  156438.     if( pMod->xDestroy ){

  156439.       pMod->xDestroy(pMod->pAux);

  156440.     }

  156441.     sqlite3VtabEponymousTableClear(db, pMod);

  156442.     sqlite3DbFree(db, pMod);

  156443.   }

  156444.   sqlite3HashClear(&db->aModule);

  156445. #endif

  156446. 

  156447.   sqlite3Error(db, SQLITE_OK); /* Deallocates any cached error strings. */

  156448.   sqlite3ValueFree(db->pErr);

  156449.   sqlite3CloseExtensions(db);

  156450. #if SQLITE_USER_AUTHENTICATION

  156451.   sqlite3_free(db->auth.zAuthUser);

  156452.   sqlite3_free(db->auth.zAuthPW);

  156453. #endif

  156454. 

  156455.   db->magic = SQLITE_MAGIC_ERROR;

  156456. 

  156457.   /* The temp-database schema is allocated differently from the other schema

  156458.   ** objects (using sqliteMalloc() directly, instead of sqlite3BtreeSchema()).

  156459.   ** So it needs to be freed here. Todo: Why not roll the temp schema into

  156460.   ** the same sqliteMalloc() as the one that allocates the database 

  156461.   ** structure?

  156462.   */

  156463.   sqlite3DbFree(db, db->aDb[1].pSchema);

  156464.   sqlite3_mutex_leave(db->mutex);

  156465.   db->magic = SQLITE_MAGIC_CLOSED;

  156466.   sqlite3_mutex_free(db->mutex);

  156467.   assert( sqlite3LookasideUsed(db,0)==0 );

  156468.   if( db->lookaside.bMalloced ){

  156469.     sqlite3_free(db->lookaside.pStart);

  156470.   }

  156471.   sqlite3_free(db);

  156472. }

  156473. 

  156474. /*

  156475. ** Rollback all database files.  If tripCode is not SQLITE_OK, then

  156476. ** any write cursors are invalidated ("tripped" - as in "tripping a circuit

  156477. ** breaker") and made to return tripCode if there are any further

  156478. ** attempts to use that cursor.  Read cursors remain open and valid

  156479. ** but are "saved" in case the table pages are moved around.

  156480. */

  156481. SQLITE_PRIVATE void sqlite3RollbackAll(sqlite3 *db, int tripCode){

  156482.   int i;

  156483.   int inTrans = 0;

  156484.   int schemaChange;

  156485.   assert( sqlite3_mutex_held(db->mutex) );

  156486.   sqlite3BeginBenignMalloc();

  156487. 

  156488.   /* Obtain all b-tree mutexes before making any calls to BtreeRollback(). 

  156489.   ** This is important in case the transaction being rolled back has

  156490.   ** modified the database schema. If the b-tree mutexes are not taken

  156491.   ** here, then another shared-cache connection might sneak in between

  156492.   ** the database rollback and schema reset, which can cause false

  156493.   ** corruption reports in some cases.  */

  156494.   sqlite3BtreeEnterAll(db);

  156495.   schemaChange = (db->mDbFlags & DBFLAG_SchemaChange)!=0 && db->init.busy==0;

  156496. 

  156497.   for(i=0; i<db->nDb; i++){

  156498.     Btree *p = db->aDb[i].pBt;

  156499.     if( p ){

  156500.       if( sqlite3BtreeIsInTrans(p) ){

  156501.         inTrans = 1;

  156502.       }

  156503.       sqlite3BtreeRollback(p, tripCode, !schemaChange);

  156504.     }

  156505.   }

  156506.   sqlite3VtabRollback(db);

  156507.   sqlite3EndBenignMalloc();

  156508. 

  156509.   if( schemaChange ){

  156510.     sqlite3ExpirePreparedStatements(db, 0);

  156511.     sqlite3ResetAllSchemasOfConnection(db);

  156512.   }

  156513.   sqlite3BtreeLeaveAll(db);

  156514. 

  156515.   /* Any deferred constraint violations have now been resolved. */

  156516.   db->nDeferredCons = 0;

  156517.   db->nDeferredImmCons = 0;

  156518.   db->flags &= ~(u64)SQLITE_DeferFKs;

  156519. 

  156520.   /* If one has been configured, invoke the rollback-hook callback */

  156521.   if( db->xRollbackCallback && (inTrans || !db->autoCommit) ){

  156522.     db->xRollbackCallback(db->pRollbackArg);

  156523.   }

  156524. }

  156525. 

  156526. /*

  156527. ** Return a static string containing the name corresponding to the error code

  156528. ** specified in the argument.

  156529. */

  156530. #if defined(SQLITE_NEED_ERR_NAME)

  156531. SQLITE_PRIVATE const char *sqlite3ErrName(int rc){

  156532.   const char *zName = 0;

  156533.   int i, origRc = rc;

  156534.   for(i=0; i<2 && zName==0; i++, rc &= 0xff){

  156535.     switch( rc ){

  156536.       case SQLITE_OK:                 zName = "SQLITE_OK";                break;

  156537.       case SQLITE_ERROR:              zName = "SQLITE_ERROR";             break;

  156538.       case SQLITE_ERROR_SNAPSHOT:     zName = "SQLITE_ERROR_SNAPSHOT";    break;

  156539.       case SQLITE_INTERNAL:           zName = "SQLITE_INTERNAL";          break;

  156540.       case SQLITE_PERM:               zName = "SQLITE_PERM";              break;

  156541.       case SQLITE_ABORT:              zName = "SQLITE_ABORT";             break;

  156542.       case SQLITE_ABORT_ROLLBACK:     zName = "SQLITE_ABORT_ROLLBACK";    break;

  156543.       case SQLITE_BUSY:               zName = "SQLITE_BUSY";              break;

  156544.       case SQLITE_BUSY_RECOVERY:      zName = "SQLITE_BUSY_RECOVERY";     break;

  156545.       case SQLITE_BUSY_SNAPSHOT:      zName = "SQLITE_BUSY_SNAPSHOT";     break;

  156546.       case SQLITE_LOCKED:             zName = "SQLITE_LOCKED";            break;

  156547.       case SQLITE_LOCKED_SHAREDCACHE: zName = "SQLITE_LOCKED_SHAREDCACHE";break;

  156548.       case SQLITE_NOMEM:              zName = "SQLITE_NOMEM";             break;

  156549.       case SQLITE_READONLY:           zName = "SQLITE_READONLY";          break;

  156550.       case SQLITE_READONLY_RECOVERY:  zName = "SQLITE_READONLY_RECOVERY"; break;

  156551.       case SQLITE_READONLY_CANTINIT:  zName = "SQLITE_READONLY_CANTINIT"; break;

  156552.       case SQLITE_READONLY_ROLLBACK:  zName = "SQLITE_READONLY_ROLLBACK"; break;

  156553.       case SQLITE_READONLY_DBMOVED:   zName = "SQLITE_READONLY_DBMOVED";  break;

  156554.       case SQLITE_READONLY_DIRECTORY: zName = "SQLITE_READONLY_DIRECTORY";break;

  156555.       case SQLITE_INTERRUPT:          zName = "SQLITE_INTERRUPT";         break;

  156556.       case SQLITE_IOERR:              zName = "SQLITE_IOERR";             break;

  156557.       case SQLITE_IOERR_READ:         zName = "SQLITE_IOERR_READ";        break;

  156558.       case SQLITE_IOERR_SHORT_READ:   zName = "SQLITE_IOERR_SHORT_READ";  break;

  156559.       case SQLITE_IOERR_WRITE:        zName = "SQLITE_IOERR_WRITE";       break;

  156560.       case SQLITE_IOERR_FSYNC:        zName = "SQLITE_IOERR_FSYNC";       break;

  156561.       case SQLITE_IOERR_DIR_FSYNC:    zName = "SQLITE_IOERR_DIR_FSYNC";   break;

  156562.       case SQLITE_IOERR_TRUNCATE:     zName = "SQLITE_IOERR_TRUNCATE";    break;

  156563.       case SQLITE_IOERR_FSTAT:        zName = "SQLITE_IOERR_FSTAT";       break;

  156564.       case SQLITE_IOERR_UNLOCK:       zName = "SQLITE_IOERR_UNLOCK";      break;

  156565.       case SQLITE_IOERR_RDLOCK:       zName = "SQLITE_IOERR_RDLOCK";      break;

  156566.       case SQLITE_IOERR_DELETE:       zName = "SQLITE_IOERR_DELETE";      break;

  156567.       case SQLITE_IOERR_NOMEM:        zName = "SQLITE_IOERR_NOMEM";       break;

  156568.       case SQLITE_IOERR_ACCESS:       zName = "SQLITE_IOERR_ACCESS";      break;

  156569.       case SQLITE_IOERR_CHECKRESERVEDLOCK:

  156570.                                 zName = "SQLITE_IOERR_CHECKRESERVEDLOCK"; break;

  156571.       case SQLITE_IOERR_LOCK:         zName = "SQLITE_IOERR_LOCK";        break;

  156572.       case SQLITE_IOERR_CLOSE:        zName = "SQLITE_IOERR_CLOSE";       break;

  156573.       case SQLITE_IOERR_DIR_CLOSE:    zName = "SQLITE_IOERR_DIR_CLOSE";   break;

  156574.       case SQLITE_IOERR_SHMOPEN:      zName = "SQLITE_IOERR_SHMOPEN";     break;

  156575.       case SQLITE_IOERR_SHMSIZE:      zName = "SQLITE_IOERR_SHMSIZE";     break;

  156576.       case SQLITE_IOERR_SHMLOCK:      zName = "SQLITE_IOERR_SHMLOCK";     break;

  156577.       case SQLITE_IOERR_SHMMAP:       zName = "SQLITE_IOERR_SHMMAP";      break;

  156578.       case SQLITE_IOERR_SEEK:         zName = "SQLITE_IOERR_SEEK";        break;

  156579.       case SQLITE_IOERR_DELETE_NOENT: zName = "SQLITE_IOERR_DELETE_NOENT";break;

  156580.       case SQLITE_IOERR_MMAP:         zName = "SQLITE_IOERR_MMAP";        break;

  156581.       case SQLITE_IOERR_GETTEMPPATH:  zName = "SQLITE_IOERR_GETTEMPPATH"; break;

  156582.       case SQLITE_IOERR_CONVPATH:     zName = "SQLITE_IOERR_CONVPATH";    break;

  156583.       case SQLITE_CORRUPT:            zName = "SQLITE_CORRUPT";           break;

  156584.       case SQLITE_CORRUPT_VTAB:       zName = "SQLITE_CORRUPT_VTAB";      break;

  156585.       case SQLITE_NOTFOUND:           zName = "SQLITE_NOTFOUND";          break;

  156586.       case SQLITE_FULL:               zName = "SQLITE_FULL";              break;

  156587.       case SQLITE_CANTOPEN:           zName = "SQLITE_CANTOPEN";          break;

  156588.       case SQLITE_CANTOPEN_NOTEMPDIR: zName = "SQLITE_CANTOPEN_NOTEMPDIR";break;

  156589.       case SQLITE_CANTOPEN_ISDIR:     zName = "SQLITE_CANTOPEN_ISDIR";    break;

  156590.       case SQLITE_CANTOPEN_FULLPATH:  zName = "SQLITE_CANTOPEN_FULLPATH"; break;

  156591.       case SQLITE_CANTOPEN_CONVPATH:  zName = "SQLITE_CANTOPEN_CONVPATH"; break;

  156592.       case SQLITE_PROTOCOL:           zName = "SQLITE_PROTOCOL";          break;

  156593.       case SQLITE_EMPTY:              zName = "SQLITE_EMPTY";             break;

  156594.       case SQLITE_SCHEMA:             zName = "SQLITE_SCHEMA";            break;

  156595.       case SQLITE_TOOBIG:             zName = "SQLITE_TOOBIG";            break;

  156596.       case SQLITE_CONSTRAINT:         zName = "SQLITE_CONSTRAINT";        break;

  156597.       case SQLITE_CONSTRAINT_UNIQUE:  zName = "SQLITE_CONSTRAINT_UNIQUE"; break;

  156598.       case SQLITE_CONSTRAINT_TRIGGER: zName = "SQLITE_CONSTRAINT_TRIGGER";break;

  156599.       case SQLITE_CONSTRAINT_FOREIGNKEY:

  156600.                                 zName = "SQLITE_CONSTRAINT_FOREIGNKEY";   break;

  156601.       case SQLITE_CONSTRAINT_CHECK:   zName = "SQLITE_CONSTRAINT_CHECK";  break;

  156602.       case SQLITE_CONSTRAINT_PRIMARYKEY:

  156603.                                 zName = "SQLITE_CONSTRAINT_PRIMARYKEY";   break;

  156604.       case SQLITE_CONSTRAINT_NOTNULL: zName = "SQLITE_CONSTRAINT_NOTNULL";break;

  156605.       case SQLITE_CONSTRAINT_COMMITHOOK:

  156606.                                 zName = "SQLITE_CONSTRAINT_COMMITHOOK";   break;

  156607.       case SQLITE_CONSTRAINT_VTAB:    zName = "SQLITE_CONSTRAINT_VTAB";   break;

  156608.       case SQLITE_CONSTRAINT_FUNCTION:

  156609.                                 zName = "SQLITE_CONSTRAINT_FUNCTION";     break;

  156610.       case SQLITE_CONSTRAINT_ROWID:   zName = "SQLITE_CONSTRAINT_ROWID";  break;

  156611.       case SQLITE_MISMATCH:           zName = "SQLITE_MISMATCH";          break;

  156612.       case SQLITE_MISUSE:             zName = "SQLITE_MISUSE";            break;

  156613.       case SQLITE_NOLFS:              zName = "SQLITE_NOLFS";             break;

  156614.       case SQLITE_AUTH:               zName = "SQLITE_AUTH";              break;

  156615.       case SQLITE_FORMAT:             zName = "SQLITE_FORMAT";            break;

  156616.       case SQLITE_RANGE:              zName = "SQLITE_RANGE";             break;

  156617.       case SQLITE_NOTADB:             zName = "SQLITE_NOTADB";            break;

  156618.       case SQLITE_ROW:                zName = "SQLITE_ROW";               break;

  156619.       case SQLITE_NOTICE:             zName = "SQLITE_NOTICE";            break;

  156620.       case SQLITE_NOTICE_RECOVER_WAL: zName = "SQLITE_NOTICE_RECOVER_WAL";break;

  156621.       case SQLITE_NOTICE_RECOVER_ROLLBACK:

  156622.                                 zName = "SQLITE_NOTICE_RECOVER_ROLLBACK"; break;

  156623.       case SQLITE_WARNING:            zName = "SQLITE_WARNING";           break;

  156624.       case SQLITE_WARNING_AUTOINDEX:  zName = "SQLITE_WARNING_AUTOINDEX"; break;

  156625.       case SQLITE_DONE:               zName = "SQLITE_DONE";              break;

  156626.     }

  156627.   }

  156628.   if( zName==0 ){

  156629.     static char zBuf[50];

  156630.     sqlite3_snprintf(sizeof(zBuf), zBuf, "SQLITE_UNKNOWN(%d)", origRc);

  156631.     zName = zBuf;

  156632.   }

  156633.   return zName;

  156634. }

  156635. #endif

  156636. 

  156637. /*

  156638. ** Return a static string that describes the kind of error specified in the

  156639. ** argument.

  156640. */

  156641. SQLITE_PRIVATE const char *sqlite3ErrStr(int rc){

  156642.   static const char* const aMsg[] = {

  156643.     /* SQLITE_OK          */ "not an error",

  156644.     /* SQLITE_ERROR       */ "SQL logic error",

  156645.     /* SQLITE_INTERNAL    */ 0,

  156646.     /* SQLITE_PERM        */ "access permission denied",

  156647.     /* SQLITE_ABORT       */ "query aborted",

  156648.     /* SQLITE_BUSY        */ "database is locked",

  156649.     /* SQLITE_LOCKED      */ "database table is locked",

  156650.     /* SQLITE_NOMEM       */ "out of memory",

  156651.     /* SQLITE_READONLY    */ "attempt to write a readonly database",

  156652.     /* SQLITE_INTERRUPT   */ "interrupted",

  156653.     /* SQLITE_IOERR       */ "disk I/O error",

  156654.     /* SQLITE_CORRUPT     */ "database disk image is malformed",

  156655.     /* SQLITE_NOTFOUND    */ "unknown operation",

  156656.     /* SQLITE_FULL        */ "database or disk is full",

  156657.     /* SQLITE_CANTOPEN    */ "unable to open database file",

  156658.     /* SQLITE_PROTOCOL    */ "locking protocol",

  156659.     /* SQLITE_EMPTY       */ 0,

  156660.     /* SQLITE_SCHEMA      */ "database schema has changed",

  156661.     /* SQLITE_TOOBIG      */ "string or blob too big",

  156662.     /* SQLITE_CONSTRAINT  */ "constraint failed",

  156663.     /* SQLITE_MISMATCH    */ "datatype mismatch",

  156664.     /* SQLITE_MISUSE      */ "bad parameter or other API misuse",

  156665. #ifdef SQLITE_DISABLE_LFS

  156666.     /* SQLITE_NOLFS       */ "large file support is disabled",

  156667. #else

  156668.     /* SQLITE_NOLFS       */ 0,

  156669. #endif

  156670.     /* SQLITE_AUTH        */ "authorization denied",

  156671.     /* SQLITE_FORMAT      */ 0,

  156672.     /* SQLITE_RANGE       */ "column index out of range",

  156673.     /* SQLITE_NOTADB      */ "file is not a database",

  156674.     /* SQLITE_NOTICE      */ "notification message",

  156675.     /* SQLITE_WARNING     */ "warning message",

  156676.   };

  156677.   const char *zErr = "unknown error";

  156678.   switch( rc ){

  156679.     case SQLITE_ABORT_ROLLBACK: {

  156680.       zErr = "abort due to ROLLBACK";

  156681.       break;

  156682.     }

  156683.     case SQLITE_ROW: {

  156684.       zErr = "another row available";

  156685.       break;

  156686.     }

  156687.     case SQLITE_DONE: {

  156688.       zErr = "no more rows available";

  156689.       break;

  156690.     }

  156691.     default: {

  156692.       rc &= 0xff;

  156693.       if( ALWAYS(rc>=0) && rc<ArraySize(aMsg) && aMsg[rc]!=0 ){

  156694.         zErr = aMsg[rc];

  156695.       }

  156696.       break;

  156697.     }

  156698.   }

  156699.   return zErr;

  156700. }

  156701. 

  156702. /*

  156703. ** This routine implements a busy callback that sleeps and tries

  156704. ** again until a timeout value is reached.  The timeout value is

  156705. ** an integer number of milliseconds passed in as the first

  156706. ** argument.

  156707. **

  156708. ** Return non-zero to retry the lock.  Return zero to stop trying

  156709. ** and cause SQLite to return SQLITE_BUSY.

  156710. */

  156711. static int sqliteDefaultBusyCallback(

  156712.   void *ptr,               /* Database connection */

  156713.   int count,               /* Number of times table has been busy */

  156714.   sqlite3_file *pFile      /* The file on which the lock occurred */

  156715. ){

  156716. #if SQLITE_OS_WIN || HAVE_USLEEP

  156717.   /* This case is for systems that have support for sleeping for fractions of

  156718.   ** a second.  Examples:  All windows systems, unix systems with usleep() */

  156719.   static const u8 delays[] =

  156720.      { 1, 2, 5, 10, 15, 20, 25, 25,  25,  50,  50, 100 };

  156721.   static const u8 totals[] =

  156722.      { 0, 1, 3,  8, 18, 33, 53, 78, 103, 128, 178, 228 };

  156723. # define NDELAY ArraySize(delays)

  156724.   sqlite3 *db = (sqlite3 *)ptr;

  156725.   int tmout = db->busyTimeout;

  156726.   int delay, prior;

  156727. 

  156728. #ifdef SQLITE_ENABLE_SETLK_TIMEOUT

  156729.   if( sqlite3OsFileControl(pFile,SQLITE_FCNTL_LOCK_TIMEOUT,&tmout)==SQLITE_OK ){

  156730.     if( count ){

  156731.       tmout = 0;

  156732.       sqlite3OsFileControl(pFile, SQLITE_FCNTL_LOCK_TIMEOUT, &tmout);

  156733.       return 0;

  156734.     }else{

  156735.       return 1;

  156736.     }

  156737.   }

  156738. #else

  156739.   UNUSED_PARAMETER(pFile);

  156740. #endif

  156741.   assert( count>=0 );

  156742.   if( count < NDELAY ){

  156743.     delay = delays[count];

  156744.     prior = totals[count];

  156745.   }else{

  156746.     delay = delays[NDELAY-1];

  156747.     prior = totals[NDELAY-1] + delay*(count-(NDELAY-1));

  156748.   }

  156749.   if( prior + delay > tmout ){

  156750.     delay = tmout - prior;

  156751.     if( delay<=0 ) return 0;

  156752.   }

  156753.   sqlite3OsSleep(db->pVfs, delay*1000);

  156754.   return 1;

  156755. #else

  156756.   /* This case for unix systems that lack usleep() support.  Sleeping

  156757.   ** must be done in increments of whole seconds */

  156758.   sqlite3 *db = (sqlite3 *)ptr;

  156759.   int tmout = ((sqlite3 *)ptr)->busyTimeout;

  156760.   UNUSED_PARAMETER(pFile);

  156761.   if( (count+1)*1000 > tmout ){

  156762.     return 0;

  156763.   }

  156764.   sqlite3OsSleep(db->pVfs, 1000000);

  156765.   return 1;

  156766. #endif

  156767. }

  156768. 

  156769. /*

  156770. ** Invoke the given busy handler.

  156771. **

  156772. ** This routine is called when an operation failed to acquire a

  156773. ** lock on VFS file pFile.

  156774. **

  156775. ** If this routine returns non-zero, the lock is retried.  If it

  156776. ** returns 0, the operation aborts with an SQLITE_BUSY error.

  156777. */

  156778. SQLITE_PRIVATE int sqlite3InvokeBusyHandler(BusyHandler *p, sqlite3_file *pFile){

  156779.   int rc;

  156780.   if( p->xBusyHandler==0 || p->nBusy<0 ) return 0;

  156781.   if( p->bExtraFileArg ){

  156782.     /* Add an extra parameter with the pFile pointer to the end of the

  156783.     ** callback argument list */

  156784.     int (*xTra)(void*,int,sqlite3_file*);

  156785.     xTra = (int(*)(void*,int,sqlite3_file*))p->xBusyHandler;

  156786.     rc = xTra(p->pBusyArg, p->nBusy, pFile);

  156787.   }else{

  156788.     /* Legacy style busy handler callback */

  156789.     rc = p->xBusyHandler(p->pBusyArg, p->nBusy);

  156790.   }

  156791.   if( rc==0 ){

  156792.     p->nBusy = -1;

  156793.   }else{

  156794.     p->nBusy++;

  156795.   }

  156796.   return rc; 

  156797. }

  156798. 

  156799. /*

  156800. ** This routine sets the busy callback for an Sqlite database to the

  156801. ** given callback function with the given argument.

  156802. */

  156803. SQLITE_API int sqlite3_busy_handler(

  156804.   sqlite3 *db,

  156805.   int (*xBusy)(void*,int),

  156806.   void *pArg

  156807. ){

  156808. #ifdef SQLITE_ENABLE_API_ARMOR

  156809.   if( !sqlite3SafetyCheckOk(db) ) return SQLITE_MISUSE_BKPT;

  156810. #endif

  156811.   sqlite3_mutex_enter(db->mutex);

  156812.   db->busyHandler.xBusyHandler = xBusy;

  156813.   db->busyHandler.pBusyArg = pArg;

  156814.   db->busyHandler.nBusy = 0;

  156815.   db->busyHandler.bExtraFileArg = 0;

  156816.   db->busyTimeout = 0;

  156817.   sqlite3_mutex_leave(db->mutex);

  156818.   return SQLITE_OK;

  156819. }

  156820. 

  156821. #ifndef SQLITE_OMIT_PROGRESS_CALLBACK

  156822. /*

  156823. ** This routine sets the progress callback for an Sqlite database to the

  156824. ** given callback function with the given argument. The progress callback will

  156825. ** be invoked every nOps opcodes.

  156826. */

  156827. SQLITE_API void sqlite3_progress_handler(

  156828.   sqlite3 *db, 

  156829.   int nOps,

  156830.   int (*xProgress)(void*), 

  156831.   void *pArg

  156832. ){

  156833. #ifdef SQLITE_ENABLE_API_ARMOR

  156834.   if( !sqlite3SafetyCheckOk(db) ){

  156835.     (void)SQLITE_MISUSE_BKPT;

  156836.     return;

  156837.   }

  156838. #endif

  156839.   sqlite3_mutex_enter(db->mutex);

  156840.   if( nOps>0 ){

  156841.     db->xProgress = xProgress;

  156842.     db->nProgressOps = (unsigned)nOps;

  156843.     db->pProgressArg = pArg;

  156844.   }else{

  156845.     db->xProgress = 0;

  156846.     db->nProgressOps = 0;

  156847.     db->pProgressArg = 0;

  156848.   }

  156849.   sqlite3_mutex_leave(db->mutex);

  156850. }

  156851. #endif

  156852. 

  156853. 

  156854. /*

  156855. ** This routine installs a default busy handler that waits for the

  156856. ** specified number of milliseconds before returning 0.

  156857. */

  156858. SQLITE_API int sqlite3_busy_timeout(sqlite3 *db, int ms){

  156859. #ifdef SQLITE_ENABLE_API_ARMOR

  156860.   if( !sqlite3SafetyCheckOk(db) ) return SQLITE_MISUSE_BKPT;

  156861. #endif

  156862.   if( ms>0 ){

  156863.     sqlite3_busy_handler(db, (int(*)(void*,int))sqliteDefaultBusyCallback,

  156864.                              (void*)db);

  156865.     db->busyTimeout = ms;

  156866.     db->busyHandler.bExtraFileArg = 1;

  156867.   }else{

  156868.     sqlite3_busy_handler(db, 0, 0);

  156869.   }

  156870.   return SQLITE_OK;

  156871. }

  156872. 

  156873. /*

  156874. ** Cause any pending operation to stop at its earliest opportunity.

  156875. */

  156876. SQLITE_API void sqlite3_interrupt(sqlite3 *db){

  156877. #ifdef SQLITE_ENABLE_API_ARMOR

  156878.   if( !sqlite3SafetyCheckOk(db) && (db==0 || db->magic!=SQLITE_MAGIC_ZOMBIE) ){

  156879.     (void)SQLITE_MISUSE_BKPT;

  156880.     return;

  156881.   }

  156882. #endif

  156883.   db->u1.isInterrupted = 1;

  156884. }

  156885. 

  156886. 

  156887. /*

  156888. ** This function is exactly the same as sqlite3_create_function(), except

  156889. ** that it is designed to be called by internal code. The difference is

  156890. ** that if a malloc() fails in sqlite3_create_function(), an error code

  156891. ** is returned and the mallocFailed flag cleared. 

  156892. */

  156893. SQLITE_PRIVATE int sqlite3CreateFunc(

  156894.   sqlite3 *db,

  156895.   const char *zFunctionName,

  156896.   int nArg,

  156897.   int enc,

  156898.   void *pUserData,

  156899.   void (*xSFunc)(sqlite3_context*,int,sqlite3_value **),

  156900.   void (*xStep)(sqlite3_context*,int,sqlite3_value **),

  156901.   void (*xFinal)(sqlite3_context*),

  156902.   void (*xValue)(sqlite3_context*),

  156903.   void (*xInverse)(sqlite3_context*,int,sqlite3_value **),

  156904.   FuncDestructor *pDestructor

  156905. ){

  156906.   FuncDef *p;

  156907.   int nName;

  156908.   int extraFlags;

  156909. 

  156910.   assert( sqlite3_mutex_held(db->mutex) );

  156911.   assert( xValue==0 || xSFunc==0 );

  156912.   if( zFunctionName==0                /* Must have a valid name */

  156913.    || (xSFunc!=0 && xFinal!=0)        /* Not both xSFunc and xFinal */

  156914.    || ((xFinal==0)!=(xStep==0))       /* Both or neither of xFinal and xStep */

  156915.    || ((xValue==0)!=(xInverse==0))    /* Both or neither of xValue, xInverse */

  156916.    || (nArg<-1 || nArg>SQLITE_MAX_FUNCTION_ARG)

  156917.    || (255<(nName = sqlite3Strlen30( zFunctionName)))

  156918.   ){

  156919.     return SQLITE_MISUSE_BKPT;

  156920.   }

  156921. 

  156922.   assert( SQLITE_FUNC_CONSTANT==SQLITE_DETERMINISTIC );

  156923.   extraFlags = enc &  SQLITE_DETERMINISTIC;

  156924.   enc &= (SQLITE_FUNC_ENCMASK|SQLITE_ANY);

  156925.   

  156926. #ifndef SQLITE_OMIT_UTF16

  156927.   /* If SQLITE_UTF16 is specified as the encoding type, transform this

  156928.   ** to one of SQLITE_UTF16LE or SQLITE_UTF16BE using the

  156929.   ** SQLITE_UTF16NATIVE macro. SQLITE_UTF16 is not used internally.

  156930.   **

  156931.   ** If SQLITE_ANY is specified, add three versions of the function

  156932.   ** to the hash table.

  156933.   */

  156934.   if( enc==SQLITE_UTF16 ){

  156935.     enc = SQLITE_UTF16NATIVE;

  156936.   }else if( enc==SQLITE_ANY ){

  156937.     int rc;

  156938.     rc = sqlite3CreateFunc(db, zFunctionName, nArg, SQLITE_UTF8|extraFlags,

  156939.          pUserData, xSFunc, xStep, xFinal, xValue, xInverse, pDestructor);

  156940.     if( rc==SQLITE_OK ){

  156941.       rc = sqlite3CreateFunc(db, zFunctionName, nArg, SQLITE_UTF16LE|extraFlags,

  156942.           pUserData, xSFunc, xStep, xFinal, xValue, xInverse, pDestructor);

  156943.     }

  156944.     if( rc!=SQLITE_OK ){

  156945.       return rc;

  156946.     }

  156947.     enc = SQLITE_UTF16BE;

  156948.   }

  156949. #else

  156950.   enc = SQLITE_UTF8;

  156951. #endif

  156952.   

  156953.   /* Check if an existing function is being overridden or deleted. If so,

  156954.   ** and there are active VMs, then return SQLITE_BUSY. If a function

  156955.   ** is being overridden/deleted but there are no active VMs, allow the

  156956.   ** operation to continue but invalidate all precompiled statements.

  156957.   */

  156958.   p = sqlite3FindFunction(db, zFunctionName, nArg, (u8)enc, 0);

  156959.   if( p && (p->funcFlags & SQLITE_FUNC_ENCMASK)==(u32)enc && p->nArg==nArg ){

  156960.     if( db->nVdbeActive ){

  156961.       sqlite3ErrorWithMsg(db, SQLITE_BUSY, 

  156962.         "unable to delete/modify user-function due to active statements");

  156963.       assert( !db->mallocFailed );

  156964.       return SQLITE_BUSY;

  156965.     }else{

  156966.       sqlite3ExpirePreparedStatements(db, 0);

  156967.     }

  156968.   }

  156969. 

  156970.   p = sqlite3FindFunction(db, zFunctionName, nArg, (u8)enc, 1);

  156971.   assert(p || db->mallocFailed);

  156972.   if( !p ){

  156973.     return SQLITE_NOMEM_BKPT;

  156974.   }

  156975. 

  156976.   /* If an older version of the function with a configured destructor is

  156977.   ** being replaced invoke the destructor function here. */

  156978.   functionDestroy(db, p);

  156979. 

  156980.   if( pDestructor ){

  156981.     pDestructor->nRef++;

  156982.   }

  156983.   p->u.pDestructor = pDestructor;

  156984.   p->funcFlags = (p->funcFlags & SQLITE_FUNC_ENCMASK) | extraFlags;

  156985.   testcase( p->funcFlags & SQLITE_DETERMINISTIC );

  156986.   p->xSFunc = xSFunc ? xSFunc : xStep;

  156987.   p->xFinalize = xFinal;

  156988.   p->xValue = xValue;

  156989.   p->xInverse = xInverse;

  156990.   p->pUserData = pUserData;

  156991.   p->nArg = (u16)nArg;

  156992.   return SQLITE_OK;

  156993. }

  156994. 

  156995. /*

  156996. ** Worker function used by utf-8 APIs that create new functions:

  156997. **

  156998. **    sqlite3_create_function()

  156999. **    sqlite3_create_function_v2()

  157000. **    sqlite3_create_window_function()

  157001. */

  157002. static int createFunctionApi(

  157003.   sqlite3 *db,

  157004.   const char *zFunc,

  157005.   int nArg,

  157006.   int enc,

  157007.   void *p,

  157008.   void (*xSFunc)(sqlite3_context*,int,sqlite3_value**),

  157009.   void (*xStep)(sqlite3_context*,int,sqlite3_value**),

  157010.   void (*xFinal)(sqlite3_context*),

  157011.   void (*xValue)(sqlite3_context*),

  157012.   void (*xInverse)(sqlite3_context*,int,sqlite3_value**),

  157013.   void(*xDestroy)(void*)

  157014. ){

  157015.   int rc = SQLITE_ERROR;

  157016.   FuncDestructor *pArg = 0;

  157017. 

  157018. #ifdef SQLITE_ENABLE_API_ARMOR

  157019.   if( !sqlite3SafetyCheckOk(db) ){

  157020.     return SQLITE_MISUSE_BKPT;

  157021.   }

  157022. #endif

  157023.   sqlite3_mutex_enter(db->mutex);

  157024.   if( xDestroy ){

  157025.     pArg = (FuncDestructor *)sqlite3Malloc(sizeof(FuncDestructor));

  157026.     if( !pArg ){

  157027.       sqlite3OomFault(db);

  157028.       xDestroy(p);

  157029.       goto out;

  157030.     }

  157031.     pArg->nRef = 0;

  157032.     pArg->xDestroy = xDestroy;

  157033.     pArg->pUserData = p;

  157034.   }

  157035.   rc = sqlite3CreateFunc(db, zFunc, nArg, enc, p, 

  157036.       xSFunc, xStep, xFinal, xValue, xInverse, pArg

  157037.   );

  157038.   if( pArg && pArg->nRef==0 ){

  157039.     assert( rc!=SQLITE_OK );

  157040.     xDestroy(p);

  157041.     sqlite3_free(pArg);

  157042.   }

  157043. 

  157044.  out:

  157045.   rc = sqlite3ApiExit(db, rc);

  157046.   sqlite3_mutex_leave(db->mutex);

  157047.   return rc;

  157048. }

  157049. 

  157050. /*

  157051. ** Create new user functions.

  157052. */

  157053. SQLITE_API int sqlite3_create_function(

  157054.   sqlite3 *db,

  157055.   const char *zFunc,

  157056.   int nArg,

  157057.   int enc,

  157058.   void *p,

  157059.   void (*xSFunc)(sqlite3_context*,int,sqlite3_value **),

  157060.   void (*xStep)(sqlite3_context*,int,sqlite3_value **),

  157061.   void (*xFinal)(sqlite3_context*)

  157062. ){

  157063.   return createFunctionApi(db, zFunc, nArg, enc, p, xSFunc, xStep,

  157064.                                     xFinal, 0, 0, 0);

  157065. }

  157066. SQLITE_API int sqlite3_create_function_v2(

  157067.   sqlite3 *db,

  157068.   const char *zFunc,

  157069.   int nArg,

  157070.   int enc,

  157071.   void *p,

  157072.   void (*xSFunc)(sqlite3_context*,int,sqlite3_value **),

  157073.   void (*xStep)(sqlite3_context*,int,sqlite3_value **),

  157074.   void (*xFinal)(sqlite3_context*),

  157075.   void (*xDestroy)(void *)

  157076. ){

  157077.   return createFunctionApi(db, zFunc, nArg, enc, p, xSFunc, xStep,

  157078.                                     xFinal, 0, 0, xDestroy);

  157079. }

  157080. SQLITE_API int sqlite3_create_window_function(

  157081.   sqlite3 *db,

  157082.   const char *zFunc,

  157083.   int nArg,

  157084.   int enc,

  157085.   void *p,

  157086.   void (*xStep)(sqlite3_context*,int,sqlite3_value **),

  157087.   void (*xFinal)(sqlite3_context*),

  157088.   void (*xValue)(sqlite3_context*),

  157089.   void (*xInverse)(sqlite3_context*,int,sqlite3_value **),

  157090.   void (*xDestroy)(void *)

  157091. ){

  157092.   return createFunctionApi(db, zFunc, nArg, enc, p, 0, xStep,

  157093.                                     xFinal, xValue, xInverse, xDestroy);

  157094. }

  157095. 

  157096. #ifndef SQLITE_OMIT_UTF16

  157097. SQLITE_API int sqlite3_create_function16(

  157098.   sqlite3 *db,

  157099.   const void *zFunctionName,

  157100.   int nArg,

  157101.   int eTextRep,

  157102.   void *p,

  157103.   void (*xSFunc)(sqlite3_context*,int,sqlite3_value**),

  157104.   void (*xStep)(sqlite3_context*,int,sqlite3_value**),

  157105.   void (*xFinal)(sqlite3_context*)

  157106. ){

  157107.   int rc;

  157108.   char *zFunc8;

  157109. 

  157110. #ifdef SQLITE_ENABLE_API_ARMOR

  157111.   if( !sqlite3SafetyCheckOk(db) || zFunctionName==0 ) return SQLITE_MISUSE_BKPT;

  157112. #endif

  157113.   sqlite3_mutex_enter(db->mutex);

  157114.   assert( !db->mallocFailed );

  157115.   zFunc8 = sqlite3Utf16to8(db, zFunctionName, -1, SQLITE_UTF16NATIVE);

  157116.   rc = sqlite3CreateFunc(db, zFunc8, nArg, eTextRep, p, xSFunc,xStep,xFinal,0,0,0);

  157117.   sqlite3DbFree(db, zFunc8);

  157118.   rc = sqlite3ApiExit(db, rc);

  157119.   sqlite3_mutex_leave(db->mutex);

  157120.   return rc;

  157121. }

  157122. #endif

  157123. 

  157124. 

  157125. /*

  157126. ** The following is the implementation of an SQL function that always

  157127. ** fails with an error message stating that the function is used in the

  157128. ** wrong context.  The sqlite3_overload_function() API might construct

  157129. ** SQL function that use this routine so that the functions will exist

  157130. ** for name resolution but are actually overloaded by the xFindFunction

  157131. ** method of virtual tables.

  157132. */

  157133. static void sqlite3InvalidFunction(

  157134.   sqlite3_context *context,  /* The function calling context */

  157135.   int NotUsed,               /* Number of arguments to the function */

  157136.   sqlite3_value **NotUsed2   /* Value of each argument */

  157137. ){

  157138.   const char *zName = (const char*)sqlite3_user_data(context);

  157139.   char *zErr;

  157140.   UNUSED_PARAMETER2(NotUsed, NotUsed2);

  157141.   zErr = sqlite3_mprintf(

  157142.       "unable to use function %s in the requested context", zName);

  157143.   sqlite3_result_error(context, zErr, -1);

  157144.   sqlite3_free(zErr);

  157145. }

  157146. 

  157147. /*

  157148. ** Declare that a function has been overloaded by a virtual table.

  157149. **

  157150. ** If the function already exists as a regular global function, then

  157151. ** this routine is a no-op.  If the function does not exist, then create

  157152. ** a new one that always throws a run-time error.  

  157153. **

  157154. ** When virtual tables intend to provide an overloaded function, they

  157155. ** should call this routine to make sure the global function exists.

  157156. ** A global function must exist in order for name resolution to work

  157157. ** properly.

  157158. */

  157159. SQLITE_API int sqlite3_overload_function(

  157160.   sqlite3 *db,

  157161.   const char *zName,

  157162.   int nArg

  157163. ){

  157164.   int rc;

  157165.   char *zCopy;

  157166. 

  157167. #ifdef SQLITE_ENABLE_API_ARMOR

  157168.   if( !sqlite3SafetyCheckOk(db) || zName==0 || nArg<-2 ){

  157169.     return SQLITE_MISUSE_BKPT;

  157170.   }

  157171. #endif

  157172.   sqlite3_mutex_enter(db->mutex);

  157173.   rc = sqlite3FindFunction(db, zName, nArg, SQLITE_UTF8, 0)!=0;

  157174.   sqlite3_mutex_leave(db->mutex);

  157175.   if( rc ) return SQLITE_OK;

  157176.   zCopy = sqlite3_mprintf(zName);

  157177.   if( zCopy==0 ) return SQLITE_NOMEM;

  157178.   return sqlite3_create_function_v2(db, zName, nArg, SQLITE_UTF8,

  157179.                            zCopy, sqlite3InvalidFunction, 0, 0, sqlite3_free);

  157180. }

  157181. 

  157182. #ifndef SQLITE_OMIT_TRACE

  157183. /*

  157184. ** Register a trace function.  The pArg from the previously registered trace

  157185. ** is returned.  

  157186. **

  157187. ** A NULL trace function means that no tracing is executes.  A non-NULL

  157188. ** trace is a pointer to a function that is invoked at the start of each

  157189. ** SQL statement.

  157190. */

  157191. #ifndef SQLITE_OMIT_DEPRECATED

  157192. SQLITE_API void *sqlite3_trace(sqlite3 *db, void(*xTrace)(void*,const char*), void *pArg){

  157193.   void *pOld;

  157194. 

  157195. #ifdef SQLITE_ENABLE_API_ARMOR

  157196.   if( !sqlite3SafetyCheckOk(db) ){

  157197.     (void)SQLITE_MISUSE_BKPT;

  157198.     return 0;

  157199.   }

  157200. #endif

  157201.   sqlite3_mutex_enter(db->mutex);

  157202.   pOld = db->pTraceArg;

  157203.   db->mTrace = xTrace ? SQLITE_TRACE_LEGACY : 0;

  157204.   db->xTrace = (int(*)(u32,void*,void*,void*))xTrace;

  157205.   db->pTraceArg = pArg;

  157206.   sqlite3_mutex_leave(db->mutex);

  157207.   return pOld;

  157208. }

  157209. #endif /* SQLITE_OMIT_DEPRECATED */

  157210. 

  157211. /* Register a trace callback using the version-2 interface.

  157212. */

  157213. SQLITE_API int sqlite3_trace_v2(

  157214.   sqlite3 *db,                               /* Trace this connection */

  157215.   unsigned mTrace,                           /* Mask of events to be traced */

  157216.   int(*xTrace)(unsigned,void*,void*,void*),  /* Callback to invoke */

  157217.   void *pArg                                 /* Context */

  157218. ){

  157219. #ifdef SQLITE_ENABLE_API_ARMOR

  157220.   if( !sqlite3SafetyCheckOk(db) ){

  157221.     return SQLITE_MISUSE_BKPT;

  157222.   }

  157223. #endif

  157224.   sqlite3_mutex_enter(db->mutex);

  157225.   if( mTrace==0 ) xTrace = 0;

  157226.   if( xTrace==0 ) mTrace = 0;

  157227.   db->mTrace = mTrace;

  157228.   db->xTrace = xTrace;

  157229.   db->pTraceArg = pArg;

  157230.   sqlite3_mutex_leave(db->mutex);

  157231.   return SQLITE_OK;

  157232. }

  157233. 

  157234. #ifndef SQLITE_OMIT_DEPRECATED

  157235. /*

  157236. ** Register a profile function.  The pArg from the previously registered 

  157237. ** profile function is returned.  

  157238. **

  157239. ** A NULL profile function means that no profiling is executes.  A non-NULL

  157240. ** profile is a pointer to a function that is invoked at the conclusion of

  157241. ** each SQL statement that is run.

  157242. */

  157243. SQLITE_API void *sqlite3_profile(

  157244.   sqlite3 *db,

  157245.   void (*xProfile)(void*,const char*,sqlite_uint64),

  157246.   void *pArg

  157247. ){

  157248.   void *pOld;

  157249. 

  157250. #ifdef SQLITE_ENABLE_API_ARMOR

  157251.   if( !sqlite3SafetyCheckOk(db) ){

  157252.     (void)SQLITE_MISUSE_BKPT;

  157253.     return 0;

  157254.   }

  157255. #endif

  157256.   sqlite3_mutex_enter(db->mutex);

  157257.   pOld = db->pProfileArg;

  157258.   db->xProfile = xProfile;

  157259.   db->pProfileArg = pArg;

  157260.   db->mTrace &= SQLITE_TRACE_NONLEGACY_MASK;

  157261.   if( db->xProfile ) db->mTrace |= SQLITE_TRACE_XPROFILE;

  157262.   sqlite3_mutex_leave(db->mutex);

  157263.   return pOld;

  157264. }

  157265. #endif /* SQLITE_OMIT_DEPRECATED */

  157266. #endif /* SQLITE_OMIT_TRACE */

  157267. 

  157268. /*

  157269. ** Register a function to be invoked when a transaction commits.

  157270. ** If the invoked function returns non-zero, then the commit becomes a

  157271. ** rollback.

  157272. */

  157273. SQLITE_API void *sqlite3_commit_hook(

  157274.   sqlite3 *db,              /* Attach the hook to this database */

  157275.   int (*xCallback)(void*),  /* Function to invoke on each commit */

  157276.   void *pArg                /* Argument to the function */

  157277. ){

  157278.   void *pOld;

  157279. 

  157280. #ifdef SQLITE_ENABLE_API_ARMOR

  157281.   if( !sqlite3SafetyCheckOk(db) ){

  157282.     (void)SQLITE_MISUSE_BKPT;

  157283.     return 0;

  157284.   }

  157285. #endif

  157286.   sqlite3_mutex_enter(db->mutex);

  157287.   pOld = db->pCommitArg;

  157288.   db->xCommitCallback = xCallback;

  157289.   db->pCommitArg = pArg;

  157290.   sqlite3_mutex_leave(db->mutex);

  157291.   return pOld;

  157292. }

  157293. 

  157294. /*

  157295. ** Register a callback to be invoked each time a row is updated,

  157296. ** inserted or deleted using this database connection.

  157297. */

  157298. SQLITE_API void *sqlite3_update_hook(

  157299.   sqlite3 *db,              /* Attach the hook to this database */

  157300.   void (*xCallback)(void*,int,char const *,char const *,sqlite_int64),

  157301.   void *pArg                /* Argument to the function */

  157302. ){

  157303.   void *pRet;

  157304. 

  157305. #ifdef SQLITE_ENABLE_API_ARMOR

  157306.   if( !sqlite3SafetyCheckOk(db) ){

  157307.     (void)SQLITE_MISUSE_BKPT;

  157308.     return 0;

  157309.   }

  157310. #endif

  157311.   sqlite3_mutex_enter(db->mutex);

  157312.   pRet = db->pUpdateArg;

  157313.   db->xUpdateCallback = xCallback;

  157314.   db->pUpdateArg = pArg;

  157315.   sqlite3_mutex_leave(db->mutex);

  157316.   return pRet;

  157317. }

  157318. 

  157319. /*

  157320. ** Register a callback to be invoked each time a transaction is rolled

  157321. ** back by this database connection.

  157322. */

  157323. SQLITE_API void *sqlite3_rollback_hook(

  157324.   sqlite3 *db,              /* Attach the hook to this database */

  157325.   void (*xCallback)(void*), /* Callback function */

  157326.   void *pArg                /* Argument to the function */

  157327. ){

  157328.   void *pRet;

  157329. 

  157330. #ifdef SQLITE_ENABLE_API_ARMOR

  157331.   if( !sqlite3SafetyCheckOk(db) ){

  157332.     (void)SQLITE_MISUSE_BKPT;

  157333.     return 0;

  157334.   }

  157335. #endif

  157336.   sqlite3_mutex_enter(db->mutex);

  157337.   pRet = db->pRollbackArg;

  157338.   db->xRollbackCallback = xCallback;

  157339.   db->pRollbackArg = pArg;

  157340.   sqlite3_mutex_leave(db->mutex);

  157341.   return pRet;

  157342. }

  157343. 

  157344. #ifdef SQLITE_ENABLE_PREUPDATE_HOOK

  157345. /*

  157346. ** Register a callback to be invoked each time a row is updated,

  157347. ** inserted or deleted using this database connection.

  157348. */

  157349. SQLITE_API void *sqlite3_preupdate_hook(

  157350.   sqlite3 *db,              /* Attach the hook to this database */

  157351.   void(*xCallback)(         /* Callback function */

  157352.     void*,sqlite3*,int,char const*,char const*,sqlite3_int64,sqlite3_int64),

  157353.   void *pArg                /* First callback argument */

  157354. ){

  157355.   void *pRet;

  157356.   sqlite3_mutex_enter(db->mutex);

  157357.   pRet = db->pPreUpdateArg;

  157358.   db->xPreUpdateCallback = xCallback;

  157359.   db->pPreUpdateArg = pArg;

  157360.   sqlite3_mutex_leave(db->mutex);

  157361.   return pRet;

  157362. }

  157363. #endif /* SQLITE_ENABLE_PREUPDATE_HOOK */

  157364. 

  157365. #ifndef SQLITE_OMIT_WAL

  157366. /*

  157367. ** The sqlite3_wal_hook() callback registered by sqlite3_wal_autocheckpoint().

  157368. ** Invoke sqlite3_wal_checkpoint if the number of frames in the log file

  157369. ** is greater than sqlite3.pWalArg cast to an integer (the value configured by

  157370. ** wal_autocheckpoint()).

  157371. */ 

  157372. SQLITE_PRIVATE int sqlite3WalDefaultHook(

  157373.   void *pClientData,     /* Argument */

  157374.   sqlite3 *db,           /* Connection */

  157375.   const char *zDb,       /* Database */

  157376.   int nFrame             /* Size of WAL */

  157377. ){

  157378.   if( nFrame>=SQLITE_PTR_TO_INT(pClientData) ){

  157379.     sqlite3BeginBenignMalloc();

  157380.     sqlite3_wal_checkpoint(db, zDb);

  157381.     sqlite3EndBenignMalloc();

  157382.   }

  157383.   return SQLITE_OK;

  157384. }

  157385. #endif /* SQLITE_OMIT_WAL */

  157386. 

  157387. /*

  157388. ** Configure an sqlite3_wal_hook() callback to automatically checkpoint

  157389. ** a database after committing a transaction if there are nFrame or

  157390. ** more frames in the log file. Passing zero or a negative value as the

  157391. ** nFrame parameter disables automatic checkpoints entirely.

  157392. **

  157393. ** The callback registered by this function replaces any existing callback

  157394. ** registered using sqlite3_wal_hook(). Likewise, registering a callback

  157395. ** using sqlite3_wal_hook() disables the automatic checkpoint mechanism

  157396. ** configured by this function.

  157397. */

  157398. SQLITE_API int sqlite3_wal_autocheckpoint(sqlite3 *db, int nFrame){

  157399. #ifdef SQLITE_OMIT_WAL

  157400.   UNUSED_PARAMETER(db);

  157401.   UNUSED_PARAMETER(nFrame);

  157402. #else

  157403. #ifdef SQLITE_ENABLE_API_ARMOR

  157404.   if( !sqlite3SafetyCheckOk(db) ) return SQLITE_MISUSE_BKPT;

  157405. #endif

  157406.   if( nFrame>0 ){

  157407.     sqlite3_wal_hook(db, sqlite3WalDefaultHook, SQLITE_INT_TO_PTR(nFrame));

  157408.   }else{

  157409.     sqlite3_wal_hook(db, 0, 0);

  157410.   }

  157411. #endif

  157412.   return SQLITE_OK;

  157413. }

  157414. 

  157415. /*

  157416. ** Register a callback to be invoked each time a transaction is written

  157417. ** into the write-ahead-log by this database connection.

  157418. */

  157419. SQLITE_API void *sqlite3_wal_hook(

  157420.   sqlite3 *db,                    /* Attach the hook to this db handle */

  157421.   int(*xCallback)(void *, sqlite3*, const char*, int),

  157422.   void *pArg                      /* First argument passed to xCallback() */

  157423. ){

  157424. #ifndef SQLITE_OMIT_WAL

  157425.   void *pRet;

  157426. #ifdef SQLITE_ENABLE_API_ARMOR

  157427.   if( !sqlite3SafetyCheckOk(db) ){

  157428.     (void)SQLITE_MISUSE_BKPT;

  157429.     return 0;

  157430.   }

  157431. #endif

  157432.   sqlite3_mutex_enter(db->mutex);

  157433.   pRet = db->pWalArg;

  157434.   db->xWalCallback = xCallback;

  157435.   db->pWalArg = pArg;

  157436.   sqlite3_mutex_leave(db->mutex);

  157437.   return pRet;

  157438. #else

  157439.   return 0;

  157440. #endif

  157441. }

  157442. 

  157443. /*

  157444. ** Checkpoint database zDb.

  157445. */

  157446. SQLITE_API int sqlite3_wal_checkpoint_v2(

  157447.   sqlite3 *db,                    /* Database handle */

  157448.   const char *zDb,                /* Name of attached database (or NULL) */

  157449.   int eMode,                      /* SQLITE_CHECKPOINT_* value */

  157450.   int *pnLog,                     /* OUT: Size of WAL log in frames */

  157451.   int *pnCkpt                     /* OUT: Total number of frames checkpointed */

  157452. ){

  157453. #ifdef SQLITE_OMIT_WAL

  157454.   return SQLITE_OK;

  157455. #else

  157456.   int rc;                         /* Return code */

  157457.   int iDb = SQLITE_MAX_ATTACHED;  /* sqlite3.aDb[] index of db to checkpoint */

  157458. 

  157459. #ifdef SQLITE_ENABLE_API_ARMOR

  157460.   if( !sqlite3SafetyCheckOk(db) ) return SQLITE_MISUSE_BKPT;

  157461. #endif

  157462. 

  157463.   /* Initialize the output variables to -1 in case an error occurs. */

  157464.   if( pnLog ) *pnLog = -1;

  157465.   if( pnCkpt ) *pnCkpt = -1;

  157466. 

  157467.   assert( SQLITE_CHECKPOINT_PASSIVE==0 );

  157468.   assert( SQLITE_CHECKPOINT_FULL==1 );

  157469.   assert( SQLITE_CHECKPOINT_RESTART==2 );

  157470.   assert( SQLITE_CHECKPOINT_TRUNCATE==3 );

  157471.   if( eMode<SQLITE_CHECKPOINT_PASSIVE || eMode>SQLITE_CHECKPOINT_TRUNCATE ){

  157472.     /* EVIDENCE-OF: R-03996-12088 The M parameter must be a valid checkpoint

  157473.     ** mode: */

  157474.     return SQLITE_MISUSE;

  157475.   }

  157476. 

  157477.   sqlite3_mutex_enter(db->mutex);

  157478.   if( zDb && zDb[0] ){

  157479.     iDb = sqlite3FindDbName(db, zDb);

  157480.   }

  157481.   if( iDb<0 ){

  157482.     rc = SQLITE_ERROR;

  157483.     sqlite3ErrorWithMsg(db, SQLITE_ERROR, "unknown database: %s", zDb);

  157484.   }else{

  157485.     db->busyHandler.nBusy = 0;

  157486.     rc = sqlite3Checkpoint(db, iDb, eMode, pnLog, pnCkpt);

  157487.     sqlite3Error(db, rc);

  157488.   }

  157489.   rc = sqlite3ApiExit(db, rc);

  157490. 

  157491.   /* If there are no active statements, clear the interrupt flag at this

  157492.   ** point.  */

  157493.   if( db->nVdbeActive==0 ){

  157494.     db->u1.isInterrupted = 0;

  157495.   }

  157496. 

  157497.   sqlite3_mutex_leave(db->mutex);

  157498.   return rc;

  157499. #endif

  157500. }

  157501. 

  157502. 

  157503. /*

  157504. ** Checkpoint database zDb. If zDb is NULL, or if the buffer zDb points

  157505. ** to contains a zero-length string, all attached databases are 

  157506. ** checkpointed.

  157507. */

  157508. SQLITE_API int sqlite3_wal_checkpoint(sqlite3 *db, const char *zDb){

  157509.   /* EVIDENCE-OF: R-41613-20553 The sqlite3_wal_checkpoint(D,X) is equivalent to

  157510.   ** sqlite3_wal_checkpoint_v2(D,X,SQLITE_CHECKPOINT_PASSIVE,0,0). */

  157511.   return sqlite3_wal_checkpoint_v2(db,zDb,SQLITE_CHECKPOINT_PASSIVE,0,0);

  157512. }

  157513. 

  157514. #ifndef SQLITE_OMIT_WAL

  157515. /*

  157516. ** Run a checkpoint on database iDb. This is a no-op if database iDb is

  157517. ** not currently open in WAL mode.

  157518. **

  157519. ** If a transaction is open on the database being checkpointed, this 

  157520. ** function returns SQLITE_LOCKED and a checkpoint is not attempted. If 

  157521. ** an error occurs while running the checkpoint, an SQLite error code is 

  157522. ** returned (i.e. SQLITE_IOERR). Otherwise, SQLITE_OK.

  157523. **

  157524. ** The mutex on database handle db should be held by the caller. The mutex

  157525. ** associated with the specific b-tree being checkpointed is taken by

  157526. ** this function while the checkpoint is running.

  157527. **

  157528. ** If iDb is passed SQLITE_MAX_ATTACHED, then all attached databases are

  157529. ** checkpointed. If an error is encountered it is returned immediately -

  157530. ** no attempt is made to checkpoint any remaining databases.

  157531. **

  157532. ** Parameter eMode is one of SQLITE_CHECKPOINT_PASSIVE, FULL, RESTART

  157533. ** or TRUNCATE.

  157534. */

  157535. SQLITE_PRIVATE int sqlite3Checkpoint(sqlite3 *db, int iDb, int eMode, int *pnLog, int *pnCkpt){

  157536.   int rc = SQLITE_OK;             /* Return code */

  157537.   int i;                          /* Used to iterate through attached dbs */

  157538.   int bBusy = 0;                  /* True if SQLITE_BUSY has been encountered */

  157539. 

  157540.   assert( sqlite3_mutex_held(db->mutex) );

  157541.   assert( !pnLog || *pnLog==-1 );

  157542.   assert( !pnCkpt || *pnCkpt==-1 );

  157543. 

  157544.   for(i=0; i<db->nDb && rc==SQLITE_OK; i++){

  157545.     if( i==iDb || iDb==SQLITE_MAX_ATTACHED ){

  157546.       rc = sqlite3BtreeCheckpoint(db->aDb[i].pBt, eMode, pnLog, pnCkpt);

  157547.       pnLog = 0;

  157548.       pnCkpt = 0;

  157549.       if( rc==SQLITE_BUSY ){

  157550.         bBusy = 1;

  157551.         rc = SQLITE_OK;

  157552.       }

  157553.     }

  157554.   }

  157555. 

  157556.   return (rc==SQLITE_OK && bBusy) ? SQLITE_BUSY : rc;

  157557. }

  157558. #endif /* SQLITE_OMIT_WAL */

  157559. 

  157560. /*

  157561. ** This function returns true if main-memory should be used instead of

  157562. ** a temporary file for transient pager files and statement journals.

  157563. ** The value returned depends on the value of db->temp_store (runtime

  157564. ** parameter) and the compile time value of SQLITE_TEMP_STORE. The

  157565. ** following table describes the relationship between these two values

  157566. ** and this functions return value.

  157567. **

  157568. **   SQLITE_TEMP_STORE     db->temp_store     Location of temporary database

  157569. **   -----------------     --------------     ------------------------------

  157570. **   0                     any                file      (return 0)

  157571. **   1                     1                  file      (return 0)

  157572. **   1                     2                  memory    (return 1)

  157573. **   1                     0                  file      (return 0)

  157574. **   2                     1                  file      (return 0)

  157575. **   2                     2                  memory    (return 1)

  157576. **   2                     0                  memory    (return 1)

  157577. **   3                     any                memory    (return 1)

  157578. */

  157579. SQLITE_PRIVATE int sqlite3TempInMemory(const sqlite3 *db){

  157580. #if SQLITE_TEMP_STORE==1

  157581.   return ( db->temp_store==2 );

  157582. #endif

  157583. #if SQLITE_TEMP_STORE==2

  157584.   return ( db->temp_store!=1 );

  157585. #endif

  157586. #if SQLITE_TEMP_STORE==3

  157587.   UNUSED_PARAMETER(db);

  157588.   return 1;

  157589. #endif

  157590. #if SQLITE_TEMP_STORE<1 || SQLITE_TEMP_STORE>3

  157591.   UNUSED_PARAMETER(db);

  157592.   return 0;

  157593. #endif

  157594. }

  157595. 

  157596. /*

  157597. ** Return UTF-8 encoded English language explanation of the most recent

  157598. ** error.

  157599. */

  157600. SQLITE_API const char *sqlite3_errmsg(sqlite3 *db){

  157601.   const char *z;

  157602.   if( !db ){

  157603.     return sqlite3ErrStr(SQLITE_NOMEM_BKPT);

  157604.   }

  157605.   if( !sqlite3SafetyCheckSickOrOk(db) ){

  157606.     return sqlite3ErrStr(SQLITE_MISUSE_BKPT);

  157607.   }

  157608.   sqlite3_mutex_enter(db->mutex);

  157609.   if( db->mallocFailed ){

  157610.     z = sqlite3ErrStr(SQLITE_NOMEM_BKPT);

  157611.   }else{

  157612.     testcase( db->pErr==0 );

  157613.     z = db->errCode ? (char*)sqlite3_value_text(db->pErr) : 0;

  157614.     assert( !db->mallocFailed );

  157615.     if( z==0 ){

  157616.       z = sqlite3ErrStr(db->errCode);

  157617.     }

  157618.   }

  157619.   sqlite3_mutex_leave(db->mutex);

  157620.   return z;

  157621. }

  157622. 

  157623. #ifndef SQLITE_OMIT_UTF16

  157624. /*

  157625. ** Return UTF-16 encoded English language explanation of the most recent

  157626. ** error.

  157627. */

  157628. SQLITE_API const void *sqlite3_errmsg16(sqlite3 *db){

  157629.   static const u16 outOfMem[] = {

  157630.     'o', 'u', 't', ' ', 'o', 'f', ' ', 'm', 'e', 'm', 'o', 'r', 'y', 0

  157631.   };

  157632.   static const u16 misuse[] = {

  157633.     'b', 'a', 'd', ' ', 'p', 'a', 'r', 'a', 'm', 'e', 't', 'e', 'r', ' ',

  157634.     'o', 'r', ' ', 'o', 't', 'h', 'e', 'r', ' ', 'A', 'P', 'I', ' ',

  157635.     'm', 'i', 's', 'u', 's', 'e', 0

  157636.   };

  157637. 

  157638.   const void *z;

  157639.   if( !db ){

  157640.     return (void *)outOfMem;

  157641.   }

  157642.   if( !sqlite3SafetyCheckSickOrOk(db) ){

  157643.     return (void *)misuse;

  157644.   }

  157645.   sqlite3_mutex_enter(db->mutex);

  157646.   if( db->mallocFailed ){

  157647.     z = (void *)outOfMem;

  157648.   }else{

  157649.     z = sqlite3_value_text16(db->pErr);

  157650.     if( z==0 ){

  157651.       sqlite3ErrorWithMsg(db, db->errCode, sqlite3ErrStr(db->errCode));

  157652.       z = sqlite3_value_text16(db->pErr);

  157653.     }

  157654.     /* A malloc() may have failed within the call to sqlite3_value_text16()

  157655.     ** above. If this is the case, then the db->mallocFailed flag needs to

  157656.     ** be cleared before returning. Do this directly, instead of via

  157657.     ** sqlite3ApiExit(), to avoid setting the database handle error message.

  157658.     */

  157659.     sqlite3OomClear(db);

  157660.   }

  157661.   sqlite3_mutex_leave(db->mutex);

  157662.   return z;

  157663. }

  157664. #endif /* SQLITE_OMIT_UTF16 */

  157665. 

  157666. /*

  157667. ** Return the most recent error code generated by an SQLite routine. If NULL is

  157668. ** passed to this function, we assume a malloc() failed during sqlite3_open().

  157669. */

  157670. SQLITE_API int sqlite3_errcode(sqlite3 *db){

  157671.   if( db && !sqlite3SafetyCheckSickOrOk(db) ){

  157672.     return SQLITE_MISUSE_BKPT;

  157673.   }

  157674.   if( !db || db->mallocFailed ){

  157675.     return SQLITE_NOMEM_BKPT;

  157676.   }

  157677.   return db->errCode & db->errMask;

  157678. }

  157679. SQLITE_API int sqlite3_extended_errcode(sqlite3 *db){

  157680.   if( db && !sqlite3SafetyCheckSickOrOk(db) ){

  157681.     return SQLITE_MISUSE_BKPT;

  157682.   }

  157683.   if( !db || db->mallocFailed ){

  157684.     return SQLITE_NOMEM_BKPT;

  157685.   }

  157686.   return db->errCode;

  157687. }

  157688. SQLITE_API int sqlite3_system_errno(sqlite3 *db){

  157689.   return db ? db->iSysErrno : 0;

  157690. }  

  157691. 

  157692. /*

  157693. ** Return a string that describes the kind of error specified in the

  157694. ** argument.  For now, this simply calls the internal sqlite3ErrStr()

  157695. ** function.

  157696. */

  157697. SQLITE_API const char *sqlite3_errstr(int rc){

  157698.   return sqlite3ErrStr(rc);

  157699. }

  157700. 

  157701. /*

  157702. ** Create a new collating function for database "db".  The name is zName

  157703. ** and the encoding is enc.

  157704. */

  157705. static int createCollation(

  157706.   sqlite3* db,

  157707.   const char *zName, 

  157708.   u8 enc,

  157709.   void* pCtx,

  157710.   int(*xCompare)(void*,int,const void*,int,const void*),

  157711.   void(*xDel)(void*)

  157712. ){

  157713.   CollSeq *pColl;

  157714.   int enc2;

  157715.   

  157716.   assert( sqlite3_mutex_held(db->mutex) );

  157717. 

  157718.   /* If SQLITE_UTF16 is specified as the encoding type, transform this

  157719.   ** to one of SQLITE_UTF16LE or SQLITE_UTF16BE using the

  157720.   ** SQLITE_UTF16NATIVE macro. SQLITE_UTF16 is not used internally.

  157721.   */

  157722.   enc2 = enc;

  157723.   testcase( enc2==SQLITE_UTF16 );

  157724.   testcase( enc2==SQLITE_UTF16_ALIGNED );

  157725.   if( enc2==SQLITE_UTF16 || enc2==SQLITE_UTF16_ALIGNED ){

  157726.     enc2 = SQLITE_UTF16NATIVE;

  157727.   }

  157728.   if( enc2<SQLITE_UTF8 || enc2>SQLITE_UTF16BE ){

  157729.     return SQLITE_MISUSE_BKPT;

  157730.   }

  157731. 

  157732.   /* Check if this call is removing or replacing an existing collation 

  157733.   ** sequence. If so, and there are active VMs, return busy. If there

  157734.   ** are no active VMs, invalidate any pre-compiled statements.

  157735.   */

  157736.   pColl = sqlite3FindCollSeq(db, (u8)enc2, zName, 0);

  157737.   if( pColl && pColl->xCmp ){

  157738.     if( db->nVdbeActive ){

  157739.       sqlite3ErrorWithMsg(db, SQLITE_BUSY, 

  157740.         "unable to delete/modify collation sequence due to active statements");

  157741.       return SQLITE_BUSY;

  157742.     }

  157743.     sqlite3ExpirePreparedStatements(db, 0);

  157744. 

  157745.     /* If collation sequence pColl was created directly by a call to

  157746.     ** sqlite3_create_collation, and not generated by synthCollSeq(),

  157747.     ** then any copies made by synthCollSeq() need to be invalidated.

  157748.     ** Also, collation destructor - CollSeq.xDel() - function may need

  157749.     ** to be called.

  157750.     */ 

  157751.     if( (pColl->enc & ~SQLITE_UTF16_ALIGNED)==enc2 ){

  157752.       CollSeq *aColl = sqlite3HashFind(&db->aCollSeq, zName);

  157753.       int j;

  157754.       for(j=0; j<3; j++){

  157755.         CollSeq *p = &aColl[j];

  157756.         if( p->enc==pColl->enc ){

  157757.           if( p->xDel ){

  157758.             p->xDel(p->pUser);

  157759.           }

  157760.           p->xCmp = 0;

  157761.         }

  157762.       }

  157763.     }

  157764.   }

  157765. 

  157766.   pColl = sqlite3FindCollSeq(db, (u8)enc2, zName, 1);

  157767.   if( pColl==0 ) return SQLITE_NOMEM_BKPT;

  157768.   pColl->xCmp = xCompare;

  157769.   pColl->pUser = pCtx;

  157770.   pColl->xDel = xDel;

  157771.   pColl->enc = (u8)(enc2 | (enc & SQLITE_UTF16_ALIGNED));

  157772.   sqlite3Error(db, SQLITE_OK);

  157773.   return SQLITE_OK;

  157774. }

  157775. 

  157776. 

  157777. /*

  157778. ** This array defines hard upper bounds on limit values.  The

  157779. ** initializer must be kept in sync with the SQLITE_LIMIT_*

  157780. ** #defines in sqlite3.h.

  157781. */

  157782. static const int aHardLimit[] = {

  157783.   SQLITE_MAX_LENGTH,

  157784.   SQLITE_MAX_SQL_LENGTH,

  157785.   SQLITE_MAX_COLUMN,

  157786.   SQLITE_MAX_EXPR_DEPTH,

  157787.   SQLITE_MAX_COMPOUND_SELECT,

  157788.   SQLITE_MAX_VDBE_OP,

  157789.   SQLITE_MAX_FUNCTION_ARG,

  157790.   SQLITE_MAX_ATTACHED,

  157791.   SQLITE_MAX_LIKE_PATTERN_LENGTH,

  157792.   SQLITE_MAX_VARIABLE_NUMBER,      /* IMP: R-38091-32352 */

  157793.   SQLITE_MAX_TRIGGER_DEPTH,

  157794.   SQLITE_MAX_WORKER_THREADS,

  157795. };

  157796. 

  157797. /*

  157798. ** Make sure the hard limits are set to reasonable values

  157799. */

  157800. #if SQLITE_MAX_LENGTH<100

  157801. # error SQLITE_MAX_LENGTH must be at least 100

  157802. #endif

  157803. #if SQLITE_MAX_SQL_LENGTH<100

  157804. # error SQLITE_MAX_SQL_LENGTH must be at least 100

  157805. #endif

  157806. #if SQLITE_MAX_SQL_LENGTH>SQLITE_MAX_LENGTH

  157807. # error SQLITE_MAX_SQL_LENGTH must not be greater than SQLITE_MAX_LENGTH

  157808. #endif

  157809. #if SQLITE_MAX_COMPOUND_SELECT<2

  157810. # error SQLITE_MAX_COMPOUND_SELECT must be at least 2

  157811. #endif

  157812. #if SQLITE_MAX_VDBE_OP<40

  157813. # error SQLITE_MAX_VDBE_OP must be at least 40

  157814. #endif

  157815. #if SQLITE_MAX_FUNCTION_ARG<0 || SQLITE_MAX_FUNCTION_ARG>127

  157816. # error SQLITE_MAX_FUNCTION_ARG must be between 0 and 127

  157817. #endif

  157818. #if SQLITE_MAX_ATTACHED<0 || SQLITE_MAX_ATTACHED>125

  157819. # error SQLITE_MAX_ATTACHED must be between 0 and 125

  157820. #endif

  157821. #if SQLITE_MAX_LIKE_PATTERN_LENGTH<1

  157822. # error SQLITE_MAX_LIKE_PATTERN_LENGTH must be at least 1

  157823. #endif

  157824. #if SQLITE_MAX_COLUMN>32767

  157825. # error SQLITE_MAX_COLUMN must not exceed 32767

  157826. #endif

  157827. #if SQLITE_MAX_TRIGGER_DEPTH<1

  157828. # error SQLITE_MAX_TRIGGER_DEPTH must be at least 1

  157829. #endif

  157830. #if SQLITE_MAX_WORKER_THREADS<0 || SQLITE_MAX_WORKER_THREADS>50

  157831. # error SQLITE_MAX_WORKER_THREADS must be between 0 and 50

  157832. #endif

  157833. 

  157834. 

  157835. /*

  157836. ** Change the value of a limit.  Report the old value.

  157837. ** If an invalid limit index is supplied, report -1.

  157838. ** Make no changes but still report the old value if the

  157839. ** new limit is negative.

  157840. **

  157841. ** A new lower limit does not shrink existing constructs.

  157842. ** It merely prevents new constructs that exceed the limit

  157843. ** from forming.

  157844. */

  157845. SQLITE_API int sqlite3_limit(sqlite3 *db, int limitId, int newLimit){

  157846.   int oldLimit;

  157847. 

  157848. #ifdef SQLITE_ENABLE_API_ARMOR

  157849.   if( !sqlite3SafetyCheckOk(db) ){

  157850.     (void)SQLITE_MISUSE_BKPT;

  157851.     return -1;

  157852.   }

  157853. #endif

  157854. 

  157855.   /* EVIDENCE-OF: R-30189-54097 For each limit category SQLITE_LIMIT_NAME

  157856.   ** there is a hard upper bound set at compile-time by a C preprocessor

  157857.   ** macro called SQLITE_MAX_NAME. (The "_LIMIT_" in the name is changed to

  157858.   ** "_MAX_".)

  157859.   */

  157860.   assert( aHardLimit[SQLITE_LIMIT_LENGTH]==SQLITE_MAX_LENGTH );

  157861.   assert( aHardLimit[SQLITE_LIMIT_SQL_LENGTH]==SQLITE_MAX_SQL_LENGTH );

  157862.   assert( aHardLimit[SQLITE_LIMIT_COLUMN]==SQLITE_MAX_COLUMN );

  157863.   assert( aHardLimit[SQLITE_LIMIT_EXPR_DEPTH]==SQLITE_MAX_EXPR_DEPTH );

  157864.   assert( aHardLimit[SQLITE_LIMIT_COMPOUND_SELECT]==SQLITE_MAX_COMPOUND_SELECT);

  157865.   assert( aHardLimit[SQLITE_LIMIT_VDBE_OP]==SQLITE_MAX_VDBE_OP );

  157866.   assert( aHardLimit[SQLITE_LIMIT_FUNCTION_ARG]==SQLITE_MAX_FUNCTION_ARG );

  157867.   assert( aHardLimit[SQLITE_LIMIT_ATTACHED]==SQLITE_MAX_ATTACHED );

  157868.   assert( aHardLimit[SQLITE_LIMIT_LIKE_PATTERN_LENGTH]==

  157869.                                                SQLITE_MAX_LIKE_PATTERN_LENGTH );

  157870.   assert( aHardLimit[SQLITE_LIMIT_VARIABLE_NUMBER]==SQLITE_MAX_VARIABLE_NUMBER);

  157871.   assert( aHardLimit[SQLITE_LIMIT_TRIGGER_DEPTH]==SQLITE_MAX_TRIGGER_DEPTH );

  157872.   assert( aHardLimit[SQLITE_LIMIT_WORKER_THREADS]==SQLITE_MAX_WORKER_THREADS );

  157873.   assert( SQLITE_LIMIT_WORKER_THREADS==(SQLITE_N_LIMIT-1) );

  157874. 

  157875. 

  157876.   if( limitId<0 || limitId>=SQLITE_N_LIMIT ){

  157877.     return -1;

  157878.   }

  157879.   oldLimit = db->aLimit[limitId];

  157880.   if( newLimit>=0 ){                   /* IMP: R-52476-28732 */

  157881.     if( newLimit>aHardLimit[limitId] ){

  157882.       newLimit = aHardLimit[limitId];  /* IMP: R-51463-25634 */

  157883.     }

  157884.     db->aLimit[limitId] = newLimit;

  157885.   }

  157886.   return oldLimit;                     /* IMP: R-53341-35419 */

  157887. }

  157888. 

  157889. /*

  157890. ** This function is used to parse both URIs and non-URI filenames passed by the

  157891. ** user to API functions sqlite3_open() or sqlite3_open_v2(), and for database

  157892. ** URIs specified as part of ATTACH statements.

  157893. **

  157894. ** The first argument to this function is the name of the VFS to use (or

  157895. ** a NULL to signify the default VFS) if the URI does not contain a "vfs=xxx"

  157896. ** query parameter. The second argument contains the URI (or non-URI filename)

  157897. ** itself. When this function is called the *pFlags variable should contain

  157898. ** the default flags to open the database handle with. The value stored in

  157899. ** *pFlags may be updated before returning if the URI filename contains 

  157900. ** "cache=xxx" or "mode=xxx" query parameters.

  157901. **

  157902. ** If successful, SQLITE_OK is returned. In this case *ppVfs is set to point to

  157903. ** the VFS that should be used to open the database file. *pzFile is set to

  157904. ** point to a buffer containing the name of the file to open. It is the 

  157905. ** responsibility of the caller to eventually call sqlite3_free() to release

  157906. ** this buffer.

  157907. **

  157908. ** If an error occurs, then an SQLite error code is returned and *pzErrMsg

  157909. ** may be set to point to a buffer containing an English language error 

  157910. ** message. It is the responsibility of the caller to eventually release

  157911. ** this buffer by calling sqlite3_free().

  157912. */

  157913. SQLITE_PRIVATE int sqlite3ParseUri(

  157914.   const char *zDefaultVfs,        /* VFS to use if no "vfs=xxx" query option */

  157915.   const char *zUri,               /* Nul-terminated URI to parse */

  157916.   unsigned int *pFlags,           /* IN/OUT: SQLITE_OPEN_XXX flags */

  157917.   sqlite3_vfs **ppVfs,            /* OUT: VFS to use */ 

  157918.   char **pzFile,                  /* OUT: Filename component of URI */

  157919.   char **pzErrMsg                 /* OUT: Error message (if rc!=SQLITE_OK) */

  157920. ){

  157921.   int rc = SQLITE_OK;

  157922.   unsigned int flags = *pFlags;

  157923.   const char *zVfs = zDefaultVfs;

  157924.   char *zFile;

  157925.   char c;

  157926.   int nUri = sqlite3Strlen30(zUri);

  157927. 

  157928.   assert( *pzErrMsg==0 );

  157929. 

  157930.   if( ((flags & SQLITE_OPEN_URI)             /* IMP: R-48725-32206 */

  157931.             || sqlite3GlobalConfig.bOpenUri) /* IMP: R-51689-46548 */

  157932.    && nUri>=5 && memcmp(zUri, "file:", 5)==0 /* IMP: R-57884-37496 */

  157933.   ){

  157934.     char *zOpt;

  157935.     int eState;                   /* Parser state when parsing URI */

  157936.     int iIn;                      /* Input character index */

  157937.     int iOut = 0;                 /* Output character index */

  157938.     u64 nByte = nUri+2;           /* Bytes of space to allocate */

  157939. 

  157940.     /* Make sure the SQLITE_OPEN_URI flag is set to indicate to the VFS xOpen 

  157941.     ** method that there may be extra parameters following the file-name.  */

  157942.     flags |= SQLITE_OPEN_URI;

  157943. 

  157944.     for(iIn=0; iIn<nUri; iIn++) nByte += (zUri[iIn]=='&');

  157945.     zFile = sqlite3_malloc64(nByte);

  157946.     if( !zFile ) return SQLITE_NOMEM_BKPT;

  157947. 

  157948.     iIn = 5;

  157949. #ifdef SQLITE_ALLOW_URI_AUTHORITY

  157950.     if( strncmp(zUri+5, "///", 3)==0 ){

  157951.       iIn = 7;

  157952.       /* The following condition causes URIs with five leading / characters

  157953.       ** like file://///host/path to be converted into UNCs like //host/path.

  157954.       ** The correct URI for that UNC has only two or four leading / characters

  157955.       ** file://host/path or file:////host/path.  But 5 leading slashes is a 

  157956.       ** common error, we are told, so we handle it as a special case. */

  157957.       if( strncmp(zUri+7, "///", 3)==0 ){ iIn++; }

  157958.     }else if( strncmp(zUri+5, "//localhost/", 12)==0 ){

  157959.       iIn = 16;

  157960.     }

  157961. #else

  157962.     /* Discard the scheme and authority segments of the URI. */

  157963.     if( zUri[5]=='/' && zUri[6]=='/' ){

  157964.       iIn = 7;

  157965.       while( zUri[iIn] && zUri[iIn]!='/' ) iIn++;

  157966.       if( iIn!=7 && (iIn!=16 || memcmp("localhost", &zUri[7], 9)) ){

  157967.         *pzErrMsg = sqlite3_mprintf("invalid uri authority: %.*s", 

  157968.             iIn-7, &zUri[7]);

  157969.         rc = SQLITE_ERROR;

  157970.         goto parse_uri_out;

  157971.       }

  157972.     }

  157973. #endif

  157974. 

  157975.     /* Copy the filename and any query parameters into the zFile buffer. 

  157976.     ** Decode %HH escape codes along the way. 

  157977.     **

  157978.     ** Within this loop, variable eState may be set to 0, 1 or 2, depending

  157979.     ** on the parsing context. As follows:

  157980.     **

  157981.     **   0: Parsing file-name.

  157982.     **   1: Parsing name section of a name=value query parameter.

  157983.     **   2: Parsing value section of a name=value query parameter.

  157984.     */

  157985.     eState = 0;

  157986.     while( (c = zUri[iIn])!=0 && c!='#' ){

  157987.       iIn++;

  157988.       if( c=='%' 

  157989.        && sqlite3Isxdigit(zUri[iIn]) 

  157990.        && sqlite3Isxdigit(zUri[iIn+1]) 

  157991.       ){

  157992.         int octet = (sqlite3HexToInt(zUri[iIn++]) << 4);

  157993.         octet += sqlite3HexToInt(zUri[iIn++]);

  157994. 

  157995.         assert( octet>=0 && octet<256 );

  157996.         if( octet==0 ){

  157997. #ifndef SQLITE_ENABLE_URI_00_ERROR

  157998.           /* This branch is taken when "%00" appears within the URI. In this

  157999.           ** case we ignore all text in the remainder of the path, name or

  158000.           ** value currently being parsed. So ignore the current character

  158001.           ** and skip to the next "?", "=" or "&", as appropriate. */

  158002.           while( (c = zUri[iIn])!=0 && c!='#' 

  158003.               && (eState!=0 || c!='?')

  158004.               && (eState!=1 || (c!='=' && c!='&'))

  158005.               && (eState!=2 || c!='&')

  158006.           ){

  158007.             iIn++;

  158008.           }

  158009.           continue;

  158010. #else

  158011.           /* If ENABLE_URI_00_ERROR is defined, "%00" in a URI is an error. */

  158012.           *pzErrMsg = sqlite3_mprintf("unexpected %%00 in uri");

  158013.           rc = SQLITE_ERROR;

  158014.           goto parse_uri_out;

  158015. #endif

  158016.         }

  158017.         c = octet;

  158018.       }else if( eState==1 && (c=='&' || c=='=') ){

  158019.         if( zFile[iOut-1]==0 ){

  158020.           /* An empty option name. Ignore this option altogether. */

  158021.           while( zUri[iIn] && zUri[iIn]!='#' && zUri[iIn-1]!='&' ) iIn++;

  158022.           continue;

  158023.         }

  158024.         if( c=='&' ){

  158025.           zFile[iOut++] = '\0';

  158026.         }else{

  158027.           eState = 2;

  158028.         }

  158029.         c = 0;

  158030.       }else if( (eState==0 && c=='?') || (eState==2 && c=='&') ){

  158031.         c = 0;

  158032.         eState = 1;

  158033.       }

  158034.       zFile[iOut++] = c;

  158035.     }

  158036.     if( eState==1 ) zFile[iOut++] = '\0';

  158037.     zFile[iOut++] = '\0';

  158038.     zFile[iOut++] = '\0';

  158039. 

  158040.     /* Check if there were any options specified that should be interpreted 

  158041.     ** here. Options that are interpreted here include "vfs" and those that

  158042.     ** correspond to flags that may be passed to the sqlite3_open_v2()

  158043.     ** method. */

  158044.     zOpt = &zFile[sqlite3Strlen30(zFile)+1];

  158045.     while( zOpt[0] ){

  158046.       int nOpt = sqlite3Strlen30(zOpt);

  158047.       char *zVal = &zOpt[nOpt+1];

  158048.       int nVal = sqlite3Strlen30(zVal);

  158049. 

  158050.       if( nOpt==3 && memcmp("vfs", zOpt, 3)==0 ){

  158051.         zVfs = zVal;

  158052.       }else{

  158053.         struct OpenMode {

  158054.           const char *z;

  158055.           int mode;

  158056.         } *aMode = 0;

  158057.         char *zModeType = 0;

  158058.         int mask = 0;

  158059.         int limit = 0;

  158060. 

  158061.         if( nOpt==5 && memcmp("cache", zOpt, 5)==0 ){

  158062.           static struct OpenMode aCacheMode[] = {

  158063.             { "shared",  SQLITE_OPEN_SHAREDCACHE },

  158064.             { "private", SQLITE_OPEN_PRIVATECACHE },

  158065.             { 0, 0 }

  158066.           };

  158067. 

  158068.           mask = SQLITE_OPEN_SHAREDCACHE|SQLITE_OPEN_PRIVATECACHE;

  158069.           aMode = aCacheMode;

  158070.           limit = mask;

  158071.           zModeType = "cache";

  158072.         }

  158073.         if( nOpt==4 && memcmp("mode", zOpt, 4)==0 ){

  158074.           static struct OpenMode aOpenMode[] = {

  158075.             { "ro",  SQLITE_OPEN_READONLY },

  158076.             { "rw",  SQLITE_OPEN_READWRITE }, 

  158077.             { "rwc", SQLITE_OPEN_READWRITE | SQLITE_OPEN_CREATE },

  158078.             { "memory", SQLITE_OPEN_MEMORY },

  158079.             { 0, 0 }

  158080.           };

  158081. 

  158082.           mask = SQLITE_OPEN_READONLY | SQLITE_OPEN_READWRITE

  158083.                    | SQLITE_OPEN_CREATE | SQLITE_OPEN_MEMORY;

  158084.           aMode = aOpenMode;

  158085.           limit = mask & flags;

  158086.           zModeType = "access";

  158087.         }

  158088. 

  158089.         if( aMode ){

  158090.           int i;

  158091.           int mode = 0;

  158092.           for(i=0; aMode[i].z; i++){

  158093.             const char *z = aMode[i].z;

  158094.             if( nVal==sqlite3Strlen30(z) && 0==memcmp(zVal, z, nVal) ){

  158095.               mode = aMode[i].mode;

  158096.               break;

  158097.             }

  158098.           }

  158099.           if( mode==0 ){

  158100.             *pzErrMsg = sqlite3_mprintf("no such %s mode: %s", zModeType, zVal);

  158101.             rc = SQLITE_ERROR;

  158102.             goto parse_uri_out;

  158103.           }

  158104.           if( (mode & ~SQLITE_OPEN_MEMORY)>limit ){

  158105.             *pzErrMsg = sqlite3_mprintf("%s mode not allowed: %s",

  158106.                                         zModeType, zVal);

  158107.             rc = SQLITE_PERM;

  158108.             goto parse_uri_out;

  158109.           }

  158110.           flags = (flags & ~mask) | mode;

  158111.         }

  158112.       }

  158113. 

  158114.       zOpt = &zVal[nVal+1];

  158115.     }

  158116. 

  158117.   }else{

  158118.     zFile = sqlite3_malloc64(nUri+2);

  158119.     if( !zFile ) return SQLITE_NOMEM_BKPT;

  158120.     if( nUri ){

  158121.       memcpy(zFile, zUri, nUri);

  158122.     }

  158123.     zFile[nUri] = '\0';

  158124.     zFile[nUri+1] = '\0';

  158125.     flags &= ~SQLITE_OPEN_URI;

  158126.   }

  158127. 

  158128.   *ppVfs = sqlite3_vfs_find(zVfs);

  158129.   if( *ppVfs==0 ){

  158130.     *pzErrMsg = sqlite3_mprintf("no such vfs: %s", zVfs);

  158131.     rc = SQLITE_ERROR;

  158132.   }

  158133.  parse_uri_out:

  158134.   if( rc!=SQLITE_OK ){

  158135.     sqlite3_free(zFile);

  158136.     zFile = 0;

  158137.   }

  158138.   *pFlags = flags;

  158139.   *pzFile = zFile;

  158140.   return rc;

  158141. }

  158142. 

  158143. #if defined(SQLITE_HAS_CODEC)

  158144. /*

  158145. ** Process URI filename query parameters relevant to the SQLite Encryption

  158146. ** Extension.  Return true if any of the relevant query parameters are

  158147. ** seen and return false if not.

  158148. */

  158149. SQLITE_PRIVATE int sqlite3CodecQueryParameters(

  158150.   sqlite3 *db,           /* Database connection */

  158151.   const char *zDb,       /* Which schema is being created/attached */

  158152.   const char *zUri       /* URI filename */

  158153. ){

  158154.   const char *zKey;

  158155.   if( (zKey = sqlite3_uri_parameter(zUri, "hexkey"))!=0 && zKey[0] ){

  158156.     u8 iByte;

  158157.     int i;

  158158.     char zDecoded[40];

  158159.     for(i=0, iByte=0; i<sizeof(zDecoded)*2 && sqlite3Isxdigit(zKey[i]); i++){

  158160.       iByte = (iByte<<4) + sqlite3HexToInt(zKey[i]);

  158161.       if( (i&1)!=0 ) zDecoded[i/2] = iByte;

  158162.     }

  158163.     sqlite3_key_v2(db, zDb, zDecoded, i/2);

  158164.     return 1;

  158165.   }else if( (zKey = sqlite3_uri_parameter(zUri, "key"))!=0 ){

  158166.     sqlite3_key_v2(db, zDb, zKey, sqlite3Strlen30(zKey));

  158167.     return 1;

  158168.   }else if( (zKey = sqlite3_uri_parameter(zUri, "textkey"))!=0 ){

  158169.     sqlite3_key_v2(db, zDb, zKey, -1);

  158170.     return 1;

  158171.   }else{

  158172.     return 0;

  158173.   }

  158174. }

  158175. #endif

  158176. 

  158177. 

  158178. /*

  158179. ** This routine does the work of opening a database on behalf of

  158180. ** sqlite3_open() and sqlite3_open16(). The database filename "zFilename"  

  158181. ** is UTF-8 encoded.

  158182. */

  158183. static int openDatabase(

  158184.   const char *zFilename, /* Database filename UTF-8 encoded */

  158185.   sqlite3 **ppDb,        /* OUT: Returned database handle */

  158186.   unsigned int flags,    /* Operational flags */

  158187.   const char *zVfs       /* Name of the VFS to use */

  158188. ){

  158189.   sqlite3 *db;                    /* Store allocated handle here */

  158190.   int rc;                         /* Return code */

  158191.   int isThreadsafe;               /* True for threadsafe connections */

  158192.   char *zOpen = 0;                /* Filename argument to pass to BtreeOpen() */

  158193.   char *zErrMsg = 0;              /* Error message from sqlite3ParseUri() */

  158194. 

  158195. #ifdef SQLITE_ENABLE_API_ARMOR

  158196.   if( ppDb==0 ) return SQLITE_MISUSE_BKPT;

  158197. #endif

  158198.   *ppDb = 0;

  158199. #ifndef SQLITE_OMIT_AUTOINIT

  158200.   rc = sqlite3_initialize();

  158201.   if( rc ) return rc;

  158202. #endif

  158203. 

  158204.   if( sqlite3GlobalConfig.bCoreMutex==0 ){

  158205.     isThreadsafe = 0;

  158206.   }else if( flags & SQLITE_OPEN_NOMUTEX ){

  158207.     isThreadsafe = 0;

  158208.   }else if( flags & SQLITE_OPEN_FULLMUTEX ){

  158209.     isThreadsafe = 1;

  158210.   }else{

  158211.     isThreadsafe = sqlite3GlobalConfig.bFullMutex;

  158212.   }

  158213. 

  158214.   if( flags & SQLITE_OPEN_PRIVATECACHE ){

  158215.     flags &= ~SQLITE_OPEN_SHAREDCACHE;

  158216.   }else if( sqlite3GlobalConfig.sharedCacheEnabled ){

  158217.     flags |= SQLITE_OPEN_SHAREDCACHE;

  158218.   }

  158219. 

  158220.   /* Remove harmful bits from the flags parameter

  158221.   **

  158222.   ** The SQLITE_OPEN_NOMUTEX and SQLITE_OPEN_FULLMUTEX flags were

  158223.   ** dealt with in the previous code block.  Besides these, the only

  158224.   ** valid input flags for sqlite3_open_v2() are SQLITE_OPEN_READONLY,

  158225.   ** SQLITE_OPEN_READWRITE, SQLITE_OPEN_CREATE, SQLITE_OPEN_SHAREDCACHE,

  158226.   ** SQLITE_OPEN_PRIVATECACHE, and some reserved bits.  Silently mask

  158227.   ** off all other flags.

  158228.   */

  158229.   flags &=  ~( SQLITE_OPEN_DELETEONCLOSE |

  158230.                SQLITE_OPEN_EXCLUSIVE |

  158231.                SQLITE_OPEN_MAIN_DB |

  158232.                SQLITE_OPEN_TEMP_DB | 

  158233.                SQLITE_OPEN_TRANSIENT_DB | 

  158234.                SQLITE_OPEN_MAIN_JOURNAL | 

  158235.                SQLITE_OPEN_TEMP_JOURNAL | 

  158236.                SQLITE_OPEN_SUBJOURNAL | 

  158237.                SQLITE_OPEN_MASTER_JOURNAL |

  158238.                SQLITE_OPEN_NOMUTEX |

  158239.                SQLITE_OPEN_FULLMUTEX |

  158240.                SQLITE_OPEN_WAL

  158241.              );

  158242. 

  158243.   /* Allocate the sqlite data structure */

  158244.   db = sqlite3MallocZero( sizeof(sqlite3) );

  158245.   if( db==0 ) goto opendb_out;

  158246.   if( isThreadsafe 

  158247. #ifdef SQLITE_ENABLE_MULTITHREADED_CHECKS

  158248.    || sqlite3GlobalConfig.bCoreMutex

  158249. #endif

  158250.   ){

  158251.     db->mutex = sqlite3MutexAlloc(SQLITE_MUTEX_RECURSIVE);

  158252.     if( db->mutex==0 ){

  158253.       sqlite3_free(db);

  158254.       db = 0;

  158255.       goto opendb_out;

  158256.     }

  158257.     if( isThreadsafe==0 ){

  158258.       sqlite3MutexWarnOnContention(db->mutex);

  158259.     }

  158260.   }

  158261.   sqlite3_mutex_enter(db->mutex);

  158262.   db->errMask = 0xff;

  158263.   db->nDb = 2;

  158264.   db->magic = SQLITE_MAGIC_BUSY;

  158265.   db->aDb = db->aDbStatic;

  158266.   db->lookaside.bDisable = 1;

  158267. 

  158268.   assert( sizeof(db->aLimit)==sizeof(aHardLimit) );

  158269.   memcpy(db->aLimit, aHardLimit, sizeof(db->aLimit));

  158270.   db->aLimit[SQLITE_LIMIT_WORKER_THREADS] = SQLITE_DEFAULT_WORKER_THREADS;

  158271.   db->autoCommit = 1;

  158272.   db->nextAutovac = -1;

  158273.   db->szMmap = sqlite3GlobalConfig.szMmap;

  158274.   db->nextPagesize = 0;

  158275.   db->nMaxSorterMmap = 0x7FFFFFFF;

  158276.   db->flags |= SQLITE_ShortColNames

  158277.                  | SQLITE_EnableTrigger

  158278.                  | SQLITE_CacheSpill

  158279. 

  158280. /* The SQLITE_DQS compile-time option determines the default settings

  158281. ** for SQLITE_DBCONFIG_DQS_DDL and SQLITE_DBCONFIG_DQS_DML.

  158282. **

  158283. **    SQLITE_DQS     SQLITE_DBCONFIG_DQS_DDL    SQLITE_DBCONFIG_DQS_DML

  158284. **    ----------     -----------------------    -----------------------

  158285. **     undefined               on                          on   

  158286. **         3                   on                          on

  158287. **         2                   on                         off

  158288. **         1                  off                          on

  158289. **         0                  off                         off

  158290. **

  158291. ** Legacy behavior is 3 (double-quoted string literals are allowed anywhere)

  158292. ** and so that is the default.  But developers are encouranged to use

  158293. ** -DSQLITE_DQS=0 (best) or -DSQLITE_DQS=1 (second choice) if possible.

  158294. */

  158295. #if !defined(SQLITE_DQS)

  158296. # define SQLITE_DQS 3

  158297. #endif

  158298. #if (SQLITE_DQS&1)==1

  158299.                  | SQLITE_DqsDML

  158300. #endif

  158301. #if (SQLITE_DQS&2)==2

  158302.                  | SQLITE_DqsDDL

  158303. #endif

  158304. 

  158305. #if !defined(SQLITE_DEFAULT_AUTOMATIC_INDEX) || SQLITE_DEFAULT_AUTOMATIC_INDEX

  158306.                  | SQLITE_AutoIndex

  158307. #endif

  158308. #if SQLITE_DEFAULT_CKPTFULLFSYNC

  158309.                  | SQLITE_CkptFullFSync

  158310. #endif

  158311. #if SQLITE_DEFAULT_FILE_FORMAT<4

  158312.                  | SQLITE_LegacyFileFmt

  158313. #endif

  158314. #ifdef SQLITE_ENABLE_LOAD_EXTENSION

  158315.                  | SQLITE_LoadExtension

  158316. #endif

  158317. #if SQLITE_DEFAULT_RECURSIVE_TRIGGERS

  158318.                  | SQLITE_RecTriggers

  158319. #endif

  158320. #if defined(SQLITE_DEFAULT_FOREIGN_KEYS) && SQLITE_DEFAULT_FOREIGN_KEYS

  158321.                  | SQLITE_ForeignKeys

  158322. #endif

  158323. #if defined(SQLITE_REVERSE_UNORDERED_SELECTS)

  158324.                  | SQLITE_ReverseOrder

  158325. #endif

  158326. #if defined(SQLITE_ENABLE_OVERSIZE_CELL_CHECK)

  158327.                  | SQLITE_CellSizeCk

  158328. #endif

  158329. #if defined(SQLITE_ENABLE_FTS3_TOKENIZER)

  158330.                  | SQLITE_Fts3Tokenizer

  158331. #endif

  158332. #if defined(SQLITE_ENABLE_QPSG)

  158333.                  | SQLITE_EnableQPSG

  158334. #endif

  158335. #if defined(SQLITE_DEFAULT_DEFENSIVE)

  158336.                  | SQLITE_Defensive

  158337. #endif

  158338.       ;

  158339.   sqlite3HashInit(&db->aCollSeq);

  158340. #ifndef SQLITE_OMIT_VIRTUALTABLE

  158341.   sqlite3HashInit(&db->aModule);

  158342. #endif

  158343. 

  158344.   /* Add the default collation sequence BINARY. BINARY works for both UTF-8

  158345.   ** and UTF-16, so add a version for each to avoid any unnecessary

  158346.   ** conversions. The only error that can occur here is a malloc() failure.

  158347.   **

  158348.   ** EVIDENCE-OF: R-52786-44878 SQLite defines three built-in collating

  158349.   ** functions:

  158350.   */

  158351.   createCollation(db, sqlite3StrBINARY, SQLITE_UTF8, 0, binCollFunc, 0);

  158352.   createCollation(db, sqlite3StrBINARY, SQLITE_UTF16BE, 0, binCollFunc, 0);

  158353.   createCollation(db, sqlite3StrBINARY, SQLITE_UTF16LE, 0, binCollFunc, 0);

  158354.   createCollation(db, "NOCASE", SQLITE_UTF8, 0, nocaseCollatingFunc, 0);

  158355.   createCollation(db, "RTRIM", SQLITE_UTF8, 0, rtrimCollFunc, 0);

  158356.   if( db->mallocFailed ){

  158357.     goto opendb_out;

  158358.   }

  158359.   /* EVIDENCE-OF: R-08308-17224 The default collating function for all

  158360.   ** strings is BINARY. 

  158361.   */

  158362.   db->pDfltColl = sqlite3FindCollSeq(db, SQLITE_UTF8, sqlite3StrBINARY, 0);

  158363.   assert( db->pDfltColl!=0 );

  158364. 

  158365.   /* Parse the filename/URI argument

  158366.   **

  158367.   ** Only allow sensible combinations of bits in the flags argument.  

  158368.   ** Throw an error if any non-sense combination is used.  If we

  158369.   ** do not block illegal combinations here, it could trigger

  158370.   ** assert() statements in deeper layers.  Sensible combinations

  158371.   ** are:

  158372.   **

  158373.   **  1:  SQLITE_OPEN_READONLY

  158374.   **  2:  SQLITE_OPEN_READWRITE

  158375.   **  6:  SQLITE_OPEN_READWRITE | SQLITE_OPEN_CREATE

  158376.   */

  158377.   db->openFlags = flags;

  158378.   assert( SQLITE_OPEN_READONLY  == 0x01 );

  158379.   assert( SQLITE_OPEN_READWRITE == 0x02 );

  158380.   assert( SQLITE_OPEN_CREATE    == 0x04 );

  158381.   testcase( (1<<(flags&7))==0x02 ); /* READONLY */

  158382.   testcase( (1<<(flags&7))==0x04 ); /* READWRITE */

  158383.   testcase( (1<<(flags&7))==0x40 ); /* READWRITE | CREATE */

  158384.   if( ((1<<(flags&7)) & 0x46)==0 ){

  158385.     rc = SQLITE_MISUSE_BKPT;  /* IMP: R-65497-44594 */

  158386.   }else{

  158387.     rc = sqlite3ParseUri(zVfs, zFilename, &flags, &db->pVfs, &zOpen, &zErrMsg);

  158388.   }

  158389.   if( rc!=SQLITE_OK ){

  158390.     if( rc==SQLITE_NOMEM ) sqlite3OomFault(db);

  158391.     sqlite3ErrorWithMsg(db, rc, zErrMsg ? "%s" : 0, zErrMsg);

  158392.     sqlite3_free(zErrMsg);

  158393.     goto opendb_out;

  158394.   }

  158395. 

  158396.   /* Open the backend database driver */

  158397.   rc = sqlite3BtreeOpen(db->pVfs, zOpen, db, &db->aDb[0].pBt, 0,

  158398.                         flags | SQLITE_OPEN_MAIN_DB);

  158399.   if( rc!=SQLITE_OK ){

  158400.     if( rc==SQLITE_IOERR_NOMEM ){

  158401.       rc = SQLITE_NOMEM_BKPT;

  158402.     }

  158403.     sqlite3Error(db, rc);

  158404.     goto opendb_out;

  158405.   }

  158406.   sqlite3BtreeEnter(db->aDb[0].pBt);

  158407.   db->aDb[0].pSchema = sqlite3SchemaGet(db, db->aDb[0].pBt);

  158408.   if( !db->mallocFailed ) ENC(db) = SCHEMA_ENC(db);

  158409.   sqlite3BtreeLeave(db->aDb[0].pBt);

  158410.   db->aDb[1].pSchema = sqlite3SchemaGet(db, 0);

  158411. 

  158412.   /* The default safety_level for the main database is FULL; for the temp

  158413.   ** database it is OFF. This matches the pager layer defaults.  

  158414.   */

  158415.   db->aDb[0].zDbSName = "main";

  158416.   db->aDb[0].safety_level = SQLITE_DEFAULT_SYNCHRONOUS+1;

  158417.   db->aDb[1].zDbSName = "temp";

  158418.   db->aDb[1].safety_level = PAGER_SYNCHRONOUS_OFF;

  158419. 

  158420.   db->magic = SQLITE_MAGIC_OPEN;

  158421.   if( db->mallocFailed ){

  158422.     goto opendb_out;

  158423.   }

  158424. 

  158425.   /* Register all built-in functions, but do not attempt to read the

  158426.   ** database schema yet. This is delayed until the first time the database

  158427.   ** is accessed.

  158428.   */

  158429.   sqlite3Error(db, SQLITE_OK);

  158430.   sqlite3RegisterPerConnectionBuiltinFunctions(db);

  158431.   rc = sqlite3_errcode(db);

  158432. 

  158433. #ifdef SQLITE_ENABLE_FTS5

  158434.   /* Register any built-in FTS5 module before loading the automatic

  158435.   ** extensions. This allows automatic extensions to register FTS5 

  158436.   ** tokenizers and auxiliary functions.  */

  158437.   if( !db->mallocFailed && rc==SQLITE_OK ){

  158438.     rc = sqlite3Fts5Init(db);

  158439.   }

  158440. #endif

  158441. 

  158442.   /* Load automatic extensions - extensions that have been registered

  158443.   ** using the sqlite3_automatic_extension() API.

  158444.   */

  158445.   if( rc==SQLITE_OK ){

  158446.     sqlite3AutoLoadExtensions(db);

  158447.     rc = sqlite3_errcode(db);

  158448.     if( rc!=SQLITE_OK ){

  158449.       goto opendb_out;

  158450.     }

  158451.   }

  158452. 

  158453. #ifdef SQLITE_ENABLE_FTS1

  158454.   if( !db->mallocFailed ){

  158455.     extern int sqlite3Fts1Init(sqlite3*);

  158456.     rc = sqlite3Fts1Init(db);

  158457.   }

  158458. #endif

  158459. 

  158460. #ifdef SQLITE_ENABLE_FTS2

  158461.   if( !db->mallocFailed && rc==SQLITE_OK ){

  158462.     extern int sqlite3Fts2Init(sqlite3*);

  158463.     rc = sqlite3Fts2Init(db);

  158464.   }

  158465. #endif

  158466. 

  158467. #ifdef SQLITE_ENABLE_FTS3 /* automatically defined by SQLITE_ENABLE_FTS4 */

  158468.   if( !db->mallocFailed && rc==SQLITE_OK ){

  158469.     rc = sqlite3Fts3Init(db);

  158470.   }

  158471. #endif

  158472. 

  158473. #if defined(SQLITE_ENABLE_ICU) || defined(SQLITE_ENABLE_ICU_COLLATIONS)

  158474.   if( !db->mallocFailed && rc==SQLITE_OK ){

  158475.     rc = sqlite3IcuInit(db);

  158476.   }

  158477. #endif

  158478. 

  158479. #ifdef SQLITE_ENABLE_RTREE

  158480.   if( !db->mallocFailed && rc==SQLITE_OK){

  158481.     rc = sqlite3RtreeInit(db);

  158482.   }

  158483. #endif

  158484. 

  158485. #ifdef SQLITE_ENABLE_DBPAGE_VTAB

  158486.   if( !db->mallocFailed && rc==SQLITE_OK){

  158487.     rc = sqlite3DbpageRegister(db);

  158488.   }

  158489. #endif

  158490. 

  158491. #ifdef SQLITE_ENABLE_DBSTAT_VTAB

  158492.   if( !db->mallocFailed && rc==SQLITE_OK){

  158493.     rc = sqlite3DbstatRegister(db);

  158494.   }

  158495. #endif

  158496. 

  158497. #ifdef SQLITE_ENABLE_JSON1

  158498.   if( !db->mallocFailed && rc==SQLITE_OK){

  158499.     rc = sqlite3Json1Init(db);

  158500.   }

  158501. #endif

  158502. 

  158503. #ifdef SQLITE_ENABLE_STMTVTAB

  158504.   if( !db->mallocFailed && rc==SQLITE_OK){

  158505.     rc = sqlite3StmtVtabInit(db);

  158506.   }

  158507. #endif

  158508. 

  158509.   /* -DSQLITE_DEFAULT_LOCKING_MODE=1 makes EXCLUSIVE the default locking

  158510.   ** mode.  -DSQLITE_DEFAULT_LOCKING_MODE=0 make NORMAL the default locking

  158511.   ** mode.  Doing nothing at all also makes NORMAL the default.

  158512.   */

  158513. #ifdef SQLITE_DEFAULT_LOCKING_MODE

  158514.   db->dfltLockMode = SQLITE_DEFAULT_LOCKING_MODE;

  158515.   sqlite3PagerLockingMode(sqlite3BtreePager(db->aDb[0].pBt),

  158516.                           SQLITE_DEFAULT_LOCKING_MODE);

  158517. #endif

  158518. 

  158519.   if( rc ) sqlite3Error(db, rc);

  158520. 

  158521.   /* Enable the lookaside-malloc subsystem */

  158522.   setupLookaside(db, 0, sqlite3GlobalConfig.szLookaside,

  158523.                         sqlite3GlobalConfig.nLookaside);

  158524. 

  158525.   sqlite3_wal_autocheckpoint(db, SQLITE_DEFAULT_WAL_AUTOCHECKPOINT);

  158526. 

  158527. opendb_out:

  158528.   if( db ){

  158529.     assert( db->mutex!=0 || isThreadsafe==0

  158530.            || sqlite3GlobalConfig.bFullMutex==0 );

  158531.     sqlite3_mutex_leave(db->mutex);

  158532.   }

  158533.   rc = sqlite3_errcode(db);

  158534.   assert( db!=0 || rc==SQLITE_NOMEM );

  158535.   if( rc==SQLITE_NOMEM ){

  158536.     sqlite3_close(db);

  158537.     db = 0;

  158538.   }else if( rc!=SQLITE_OK ){

  158539.     db->magic = SQLITE_MAGIC_SICK;

  158540.   }

  158541.   *ppDb = db;

  158542. #ifdef SQLITE_ENABLE_SQLLOG

  158543.   if( sqlite3GlobalConfig.xSqllog ){

  158544.     /* Opening a db handle. Fourth parameter is passed 0. */

  158545.     void *pArg = sqlite3GlobalConfig.pSqllogArg;

  158546.     sqlite3GlobalConfig.xSqllog(pArg, db, zFilename, 0);

  158547.   }

  158548. #endif

  158549. #if defined(SQLITE_HAS_CODEC)

  158550.   if( rc==SQLITE_OK ) sqlite3CodecQueryParameters(db, 0, zOpen);

  158551. #endif

  158552.   sqlite3_free(zOpen);

  158553.   return rc & 0xff;

  158554. }

  158555. 

  158556. 

  158557. /*

  158558. ** Open a new database handle.

  158559. */

  158560. SQLITE_API int sqlite3_open(

  158561.   const char *zFilename, 

  158562.   sqlite3 **ppDb 

  158563. ){

  158564.   return openDatabase(zFilename, ppDb,

  158565.                       SQLITE_OPEN_READWRITE | SQLITE_OPEN_CREATE, 0);

  158566. }

  158567. SQLITE_API int sqlite3_open_v2(

  158568.   const char *filename,   /* Database filename (UTF-8) */

  158569.   sqlite3 **ppDb,         /* OUT: SQLite db handle */

  158570.   int flags,              /* Flags */

  158571.   const char *zVfs        /* Name of VFS module to use */

  158572. ){

  158573.   return openDatabase(filename, ppDb, (unsigned int)flags, zVfs);

  158574. }

  158575. 

  158576. #ifndef SQLITE_OMIT_UTF16

  158577. /*

  158578. ** Open a new database handle.

  158579. */

  158580. SQLITE_API int sqlite3_open16(

  158581.   const void *zFilename, 

  158582.   sqlite3 **ppDb

  158583. ){

  158584.   char const *zFilename8;   /* zFilename encoded in UTF-8 instead of UTF-16 */

  158585.   sqlite3_value *pVal;

  158586.   int rc;

  158587. 

  158588. #ifdef SQLITE_ENABLE_API_ARMOR

  158589.   if( ppDb==0 ) return SQLITE_MISUSE_BKPT;

  158590. #endif

  158591.   *ppDb = 0;

  158592. #ifndef SQLITE_OMIT_AUTOINIT

  158593.   rc = sqlite3_initialize();

  158594.   if( rc ) return rc;

  158595. #endif

  158596.   if( zFilename==0 ) zFilename = "\000\000";

  158597.   pVal = sqlite3ValueNew(0);

  158598.   sqlite3ValueSetStr(pVal, -1, zFilename, SQLITE_UTF16NATIVE, SQLITE_STATIC);

  158599.   zFilename8 = sqlite3ValueText(pVal, SQLITE_UTF8);

  158600.   if( zFilename8 ){

  158601.     rc = openDatabase(zFilename8, ppDb,

  158602.                       SQLITE_OPEN_READWRITE | SQLITE_OPEN_CREATE, 0);

  158603.     assert( *ppDb || rc==SQLITE_NOMEM );

  158604.     if( rc==SQLITE_OK && !DbHasProperty(*ppDb, 0, DB_SchemaLoaded) ){

  158605.       SCHEMA_ENC(*ppDb) = ENC(*ppDb) = SQLITE_UTF16NATIVE;

  158606.     }

  158607.   }else{

  158608.     rc = SQLITE_NOMEM_BKPT;

  158609.   }

  158610.   sqlite3ValueFree(pVal);

  158611. 

  158612.   return rc & 0xff;

  158613. }

  158614. #endif /* SQLITE_OMIT_UTF16 */

  158615. 

  158616. /*

  158617. ** Register a new collation sequence with the database handle db.

  158618. */

  158619. SQLITE_API int sqlite3_create_collation(

  158620.   sqlite3* db, 

  158621.   const char *zName, 

  158622.   int enc, 

  158623.   void* pCtx,

  158624.   int(*xCompare)(void*,int,const void*,int,const void*)

  158625. ){

  158626.   return sqlite3_create_collation_v2(db, zName, enc, pCtx, xCompare, 0);

  158627. }

  158628. 

  158629. /*

  158630. ** Register a new collation sequence with the database handle db.

  158631. */

  158632. SQLITE_API int sqlite3_create_collation_v2(

  158633.   sqlite3* db, 

  158634.   const char *zName, 

  158635.   int enc, 

  158636.   void* pCtx,

  158637.   int(*xCompare)(void*,int,const void*,int,const void*),

  158638.   void(*xDel)(void*)

  158639. ){

  158640.   int rc;

  158641. 

  158642. #ifdef SQLITE_ENABLE_API_ARMOR

  158643.   if( !sqlite3SafetyCheckOk(db) || zName==0 ) return SQLITE_MISUSE_BKPT;

  158644. #endif

  158645.   sqlite3_mutex_enter(db->mutex);

  158646.   assert( !db->mallocFailed );

  158647.   rc = createCollation(db, zName, (u8)enc, pCtx, xCompare, xDel);

  158648.   rc = sqlite3ApiExit(db, rc);

  158649.   sqlite3_mutex_leave(db->mutex);

  158650.   return rc;

  158651. }

  158652. 

  158653. #ifndef SQLITE_OMIT_UTF16

  158654. /*

  158655. ** Register a new collation sequence with the database handle db.

  158656. */

  158657. SQLITE_API int sqlite3_create_collation16(

  158658.   sqlite3* db, 

  158659.   const void *zName,

  158660.   int enc, 

  158661.   void* pCtx,

  158662.   int(*xCompare)(void*,int,const void*,int,const void*)

  158663. ){

  158664.   int rc = SQLITE_OK;

  158665.   char *zName8;

  158666. 

  158667. #ifdef SQLITE_ENABLE_API_ARMOR

  158668.   if( !sqlite3SafetyCheckOk(db) || zName==0 ) return SQLITE_MISUSE_BKPT;

  158669. #endif

  158670.   sqlite3_mutex_enter(db->mutex);

  158671.   assert( !db->mallocFailed );

  158672.   zName8 = sqlite3Utf16to8(db, zName, -1, SQLITE_UTF16NATIVE);

  158673.   if( zName8 ){

  158674.     rc = createCollation(db, zName8, (u8)enc, pCtx, xCompare, 0);

  158675.     sqlite3DbFree(db, zName8);

  158676.   }

  158677.   rc = sqlite3ApiExit(db, rc);

  158678.   sqlite3_mutex_leave(db->mutex);

  158679.   return rc;

  158680. }

  158681. #endif /* SQLITE_OMIT_UTF16 */

  158682. 

  158683. /*

  158684. ** Register a collation sequence factory callback with the database handle

  158685. ** db. Replace any previously installed collation sequence factory.

  158686. */

  158687. SQLITE_API int sqlite3_collation_needed(

  158688.   sqlite3 *db, 

  158689.   void *pCollNeededArg, 

  158690.   void(*xCollNeeded)(void*,sqlite3*,int eTextRep,const char*)

  158691. ){

  158692. #ifdef SQLITE_ENABLE_API_ARMOR

  158693.   if( !sqlite3SafetyCheckOk(db) ) return SQLITE_MISUSE_BKPT;

  158694. #endif

  158695.   sqlite3_mutex_enter(db->mutex);

  158696.   db->xCollNeeded = xCollNeeded;

  158697.   db->xCollNeeded16 = 0;

  158698.   db->pCollNeededArg = pCollNeededArg;

  158699.   sqlite3_mutex_leave(db->mutex);

  158700.   return SQLITE_OK;

  158701. }

  158702. 

  158703. #ifndef SQLITE_OMIT_UTF16

  158704. /*

  158705. ** Register a collation sequence factory callback with the database handle

  158706. ** db. Replace any previously installed collation sequence factory.

  158707. */

  158708. SQLITE_API int sqlite3_collation_needed16(

  158709.   sqlite3 *db, 

  158710.   void *pCollNeededArg, 

  158711.   void(*xCollNeeded16)(void*,sqlite3*,int eTextRep,const void*)

  158712. ){

  158713. #ifdef SQLITE_ENABLE_API_ARMOR

  158714.   if( !sqlite3SafetyCheckOk(db) ) return SQLITE_MISUSE_BKPT;

  158715. #endif

  158716.   sqlite3_mutex_enter(db->mutex);

  158717.   db->xCollNeeded = 0;

  158718.   db->xCollNeeded16 = xCollNeeded16;

  158719.   db->pCollNeededArg = pCollNeededArg;

  158720.   sqlite3_mutex_leave(db->mutex);

  158721.   return SQLITE_OK;

  158722. }

  158723. #endif /* SQLITE_OMIT_UTF16 */

  158724. 

  158725. #ifndef SQLITE_OMIT_DEPRECATED

  158726. /*

  158727. ** This function is now an anachronism. It used to be used to recover from a

  158728. ** malloc() failure, but SQLite now does this automatically.

  158729. */

  158730. SQLITE_API int sqlite3_global_recover(void){

  158731.   return SQLITE_OK;

  158732. }

  158733. #endif

  158734. 

  158735. /*

  158736. ** Test to see whether or not the database connection is in autocommit

  158737. ** mode.  Return TRUE if it is and FALSE if not.  Autocommit mode is on

  158738. ** by default.  Autocommit is disabled by a BEGIN statement and reenabled

  158739. ** by the next COMMIT or ROLLBACK.

  158740. */

  158741. SQLITE_API int sqlite3_get_autocommit(sqlite3 *db){

  158742. #ifdef SQLITE_ENABLE_API_ARMOR

  158743.   if( !sqlite3SafetyCheckOk(db) ){

  158744.     (void)SQLITE_MISUSE_BKPT;

  158745.     return 0;

  158746.   }

  158747. #endif

  158748.   return db->autoCommit;

  158749. }

  158750. 

  158751. /*

  158752. ** The following routines are substitutes for constants SQLITE_CORRUPT,

  158753. ** SQLITE_MISUSE, SQLITE_CANTOPEN, SQLITE_NOMEM and possibly other error

  158754. ** constants.  They serve two purposes:

  158755. **

  158756. **   1.  Serve as a convenient place to set a breakpoint in a debugger

  158757. **       to detect when version error conditions occurs.

  158758. **

  158759. **   2.  Invoke sqlite3_log() to provide the source code location where

  158760. **       a low-level error is first detected.

  158761. */

  158762. SQLITE_PRIVATE int sqlite3ReportError(int iErr, int lineno, const char *zType){

  158763.   sqlite3_log(iErr, "%s at line %d of [%.10s]",

  158764.               zType, lineno, 20+sqlite3_sourceid());

  158765.   return iErr;

  158766. }

  158767. SQLITE_PRIVATE int sqlite3CorruptError(int lineno){

  158768.   testcase( sqlite3GlobalConfig.xLog!=0 );

  158769.   return sqlite3ReportError(SQLITE_CORRUPT, lineno, "database corruption");

  158770. }

  158771. SQLITE_PRIVATE int sqlite3MisuseError(int lineno){

  158772.   testcase( sqlite3GlobalConfig.xLog!=0 );

  158773.   return sqlite3ReportError(SQLITE_MISUSE, lineno, "misuse");

  158774. }

  158775. SQLITE_PRIVATE int sqlite3CantopenError(int lineno){

  158776.   testcase( sqlite3GlobalConfig.xLog!=0 );

  158777.   return sqlite3ReportError(SQLITE_CANTOPEN, lineno, "cannot open file");

  158778. }

  158779. #ifdef SQLITE_DEBUG

  158780. SQLITE_PRIVATE int sqlite3CorruptPgnoError(int lineno, Pgno pgno){

  158781.   char zMsg[100];

  158782.   sqlite3_snprintf(sizeof(zMsg), zMsg, "database corruption page %d", pgno);

  158783.   testcase( sqlite3GlobalConfig.xLog!=0 );

  158784.   return sqlite3ReportError(SQLITE_CORRUPT, lineno, zMsg);

  158785. }

  158786. SQLITE_PRIVATE int sqlite3NomemError(int lineno){

  158787.   testcase( sqlite3GlobalConfig.xLog!=0 );

  158788.   return sqlite3ReportError(SQLITE_NOMEM, lineno, "OOM");

  158789. }

  158790. SQLITE_PRIVATE int sqlite3IoerrnomemError(int lineno){

  158791.   testcase( sqlite3GlobalConfig.xLog!=0 );

  158792.   return sqlite3ReportError(SQLITE_IOERR_NOMEM, lineno, "I/O OOM error");

  158793. }

  158794. #endif

  158795. 

  158796. #ifndef SQLITE_OMIT_DEPRECATED

  158797. /*

  158798. ** This is a convenience routine that makes sure that all thread-specific

  158799. ** data for this thread has been deallocated.

  158800. **

  158801. ** SQLite no longer uses thread-specific data so this routine is now a

  158802. ** no-op.  It is retained for historical compatibility.

  158803. */

  158804. SQLITE_API void sqlite3_thread_cleanup(void){

  158805. }

  158806. #endif

  158807. 

  158808. /*

  158809. ** Return meta information about a specific column of a database table.

  158810. ** See comment in sqlite3.h (sqlite.h.in) for details.

  158811. */

  158812. SQLITE_API int sqlite3_table_column_metadata(

  158813.   sqlite3 *db,                /* Connection handle */

  158814.   const char *zDbName,        /* Database name or NULL */

  158815.   const char *zTableName,     /* Table name */

  158816.   const char *zColumnName,    /* Column name */

  158817.   char const **pzDataType,    /* OUTPUT: Declared data type */

  158818.   char const **pzCollSeq,     /* OUTPUT: Collation sequence name */

  158819.   int *pNotNull,              /* OUTPUT: True if NOT NULL constraint exists */

  158820.   int *pPrimaryKey,           /* OUTPUT: True if column part of PK */

  158821.   int *pAutoinc               /* OUTPUT: True if column is auto-increment */

  158822. ){

  158823.   int rc;

  158824.   char *zErrMsg = 0;

  158825.   Table *pTab = 0;

  158826.   Column *pCol = 0;

  158827.   int iCol = 0;

  158828.   char const *zDataType = 0;

  158829.   char const *zCollSeq = 0;

  158830.   int notnull = 0;

  158831.   int primarykey = 0;

  158832.   int autoinc = 0;

  158833. 

  158834. 

  158835. #ifdef SQLITE_ENABLE_API_ARMOR

  158836.   if( !sqlite3SafetyCheckOk(db) || zTableName==0 ){

  158837.     return SQLITE_MISUSE_BKPT;

  158838.   }

  158839. #endif

  158840. 

  158841.   /* Ensure the database schema has been loaded */

  158842.   sqlite3_mutex_enter(db->mutex);

  158843.   sqlite3BtreeEnterAll(db);

  158844.   rc = sqlite3Init(db, &zErrMsg);

  158845.   if( SQLITE_OK!=rc ){

  158846.     goto error_out;

  158847.   }

  158848. 

  158849.   /* Locate the table in question */

  158850.   pTab = sqlite3FindTable(db, zTableName, zDbName);

  158851.   if( !pTab || pTab->pSelect ){

  158852.     pTab = 0;

  158853.     goto error_out;

  158854.   }

  158855. 

  158856.   /* Find the column for which info is requested */

  158857.   if( zColumnName==0 ){

  158858.     /* Query for existance of table only */

  158859.   }else{

  158860.     for(iCol=0; iCol<pTab->nCol; iCol++){

  158861.       pCol = &pTab->aCol[iCol];

  158862.       if( 0==sqlite3StrICmp(pCol->zName, zColumnName) ){

  158863.         break;

  158864.       }

  158865.     }

  158866.     if( iCol==pTab->nCol ){

  158867.       if( HasRowid(pTab) && sqlite3IsRowid(zColumnName) ){

  158868.         iCol = pTab->iPKey;

  158869.         pCol = iCol>=0 ? &pTab->aCol[iCol] : 0;

  158870.       }else{

  158871.         pTab = 0;

  158872.         goto error_out;

  158873.       }

  158874.     }

  158875.   }

  158876. 

  158877.   /* The following block stores the meta information that will be returned

  158878.   ** to the caller in local variables zDataType, zCollSeq, notnull, primarykey

  158879.   ** and autoinc. At this point there are two possibilities:

  158880.   ** 

  158881.   **     1. The specified column name was rowid", "oid" or "_rowid_" 

  158882.   **        and there is no explicitly declared IPK column. 

  158883.   **

  158884.   **     2. The table is not a view and the column name identified an 

  158885.   **        explicitly declared column. Copy meta information from *pCol.

  158886.   */ 

  158887.   if( pCol ){

  158888.     zDataType = sqlite3ColumnType(pCol,0);

  158889.     zCollSeq = pCol->zColl;

  158890.     notnull = pCol->notNull!=0;

  158891.     primarykey  = (pCol->colFlags & COLFLAG_PRIMKEY)!=0;

  158892.     autoinc = pTab->iPKey==iCol && (pTab->tabFlags & TF_Autoincrement)!=0;

  158893.   }else{

  158894.     zDataType = "INTEGER";

  158895.     primarykey = 1;

  158896.   }

  158897.   if( !zCollSeq ){

  158898.     zCollSeq = sqlite3StrBINARY;

  158899.   }

  158900. 

  158901. error_out:

  158902.   sqlite3BtreeLeaveAll(db);

  158903. 

  158904.   /* Whether the function call succeeded or failed, set the output parameters

  158905.   ** to whatever their local counterparts contain. If an error did occur,

  158906.   ** this has the effect of zeroing all output parameters.

  158907.   */

  158908.   if( pzDataType ) *pzDataType = zDataType;

  158909.   if( pzCollSeq ) *pzCollSeq = zCollSeq;

  158910.   if( pNotNull ) *pNotNull = notnull;

  158911.   if( pPrimaryKey ) *pPrimaryKey = primarykey;

  158912.   if( pAutoinc ) *pAutoinc = autoinc;

  158913. 

  158914.   if( SQLITE_OK==rc && !pTab ){

  158915.     sqlite3DbFree(db, zErrMsg);

  158916.     zErrMsg = sqlite3MPrintf(db, "no such table column: %s.%s", zTableName,

  158917.         zColumnName);

  158918.     rc = SQLITE_ERROR;

  158919.   }

  158920.   sqlite3ErrorWithMsg(db, rc, (zErrMsg?"%s":0), zErrMsg);

  158921.   sqlite3DbFree(db, zErrMsg);

  158922.   rc = sqlite3ApiExit(db, rc);

  158923.   sqlite3_mutex_leave(db->mutex);

  158924.   return rc;

  158925. }

  158926. 

  158927. /*

  158928. ** Sleep for a little while.  Return the amount of time slept.

  158929. */

  158930. SQLITE_API int sqlite3_sleep(int ms){

  158931.   sqlite3_vfs *pVfs;

  158932.   int rc;

  158933.   pVfs = sqlite3_vfs_find(0);

  158934.   if( pVfs==0 ) return 0;

  158935. 

  158936.   /* This function works in milliseconds, but the underlying OsSleep() 

  158937.   ** API uses microseconds. Hence the 1000's.

  158938.   */

  158939.   rc = (sqlite3OsSleep(pVfs, 1000*ms)/1000);

  158940.   return rc;

  158941. }

  158942. 

  158943. /*

  158944. ** Enable or disable the extended result codes.

  158945. */

  158946. SQLITE_API int sqlite3_extended_result_codes(sqlite3 *db, int onoff){

  158947. #ifdef SQLITE_ENABLE_API_ARMOR

  158948.   if( !sqlite3SafetyCheckOk(db) ) return SQLITE_MISUSE_BKPT;

  158949. #endif

  158950.   sqlite3_mutex_enter(db->mutex);

  158951.   db->errMask = onoff ? 0xffffffff : 0xff;

  158952.   sqlite3_mutex_leave(db->mutex);

  158953.   return SQLITE_OK;

  158954. }

  158955. 

  158956. /*

  158957. ** Invoke the xFileControl method on a particular database.

  158958. */

  158959. SQLITE_API int sqlite3_file_control(sqlite3 *db, const char *zDbName, int op, void *pArg){

  158960.   int rc = SQLITE_ERROR;

  158961.   Btree *pBtree;

  158962. 

  158963. #ifdef SQLITE_ENABLE_API_ARMOR

  158964.   if( !sqlite3SafetyCheckOk(db) ) return SQLITE_MISUSE_BKPT;

  158965. #endif

  158966.   sqlite3_mutex_enter(db->mutex);

  158967.   pBtree = sqlite3DbNameToBtree(db, zDbName);

  158968.   if( pBtree ){

  158969.     Pager *pPager;

  158970.     sqlite3_file *fd;

  158971.     sqlite3BtreeEnter(pBtree);

  158972.     pPager = sqlite3BtreePager(pBtree);

  158973.     assert( pPager!=0 );

  158974.     fd = sqlite3PagerFile(pPager);

  158975.     assert( fd!=0 );

  158976.     if( op==SQLITE_FCNTL_FILE_POINTER ){

  158977.       *(sqlite3_file**)pArg = fd;

  158978.       rc = SQLITE_OK;

  158979.     }else if( op==SQLITE_FCNTL_VFS_POINTER ){

  158980.       *(sqlite3_vfs**)pArg = sqlite3PagerVfs(pPager);

  158981.       rc = SQLITE_OK;

  158982.     }else if( op==SQLITE_FCNTL_JOURNAL_POINTER ){

  158983.       *(sqlite3_file**)pArg = sqlite3PagerJrnlFile(pPager);

  158984.       rc = SQLITE_OK;

  158985.     }else if( op==SQLITE_FCNTL_DATA_VERSION ){

  158986.       *(unsigned int*)pArg = sqlite3PagerDataVersion(pPager);

  158987.       rc = SQLITE_OK;

  158988.     }else{

  158989.       rc = sqlite3OsFileControl(fd, op, pArg);

  158990.     }

  158991.     sqlite3BtreeLeave(pBtree);

  158992.   }

  158993.   sqlite3_mutex_leave(db->mutex);

  158994.   return rc;

  158995. }

  158996. 

  158997. /*

  158998. ** Interface to the testing logic.

  158999. */

  159000. SQLITE_API int sqlite3_test_control(int op, ...){

  159001.   int rc = 0;

  159002. #ifdef SQLITE_UNTESTABLE

  159003.   UNUSED_PARAMETER(op);

  159004. #else

  159005.   va_list ap;

  159006.   va_start(ap, op);

  159007.   switch( op ){

  159008. 

  159009.     /*

  159010.     ** Save the current state of the PRNG.

  159011.     */

  159012.     case SQLITE_TESTCTRL_PRNG_SAVE: {

  159013.       sqlite3PrngSaveState();

  159014.       break;

  159015.     }

  159016. 

  159017.     /*

  159018.     ** Restore the state of the PRNG to the last state saved using

  159019.     ** PRNG_SAVE.  If PRNG_SAVE has never before been called, then

  159020.     ** this verb acts like PRNG_RESET.

  159021.     */

  159022.     case SQLITE_TESTCTRL_PRNG_RESTORE: {

  159023.       sqlite3PrngRestoreState();

  159024.       break;

  159025.     }

  159026. 

  159027.     /*

  159028.     ** Reset the PRNG back to its uninitialized state.  The next call

  159029.     ** to sqlite3_randomness() will reseed the PRNG using a single call

  159030.     ** to the xRandomness method of the default VFS.

  159031.     */

  159032.     case SQLITE_TESTCTRL_PRNG_RESET: {

  159033.       sqlite3_randomness(0,0);

  159034.       break;

  159035.     }

  159036. 

  159037.     /*

  159038.     **  sqlite3_test_control(BITVEC_TEST, size, program)

  159039.     **

  159040.     ** Run a test against a Bitvec object of size.  The program argument

  159041.     ** is an array of integers that defines the test.  Return -1 on a

  159042.     ** memory allocation error, 0 on success, or non-zero for an error.

  159043.     ** See the sqlite3BitvecBuiltinTest() for additional information.

  159044.     */

  159045.     case SQLITE_TESTCTRL_BITVEC_TEST: {

  159046.       int sz = va_arg(ap, int);

  159047.       int *aProg = va_arg(ap, int*);

  159048.       rc = sqlite3BitvecBuiltinTest(sz, aProg);

  159049.       break;

  159050.     }

  159051. 

  159052.     /*

  159053.     **  sqlite3_test_control(FAULT_INSTALL, xCallback)

  159054.     **

  159055.     ** Arrange to invoke xCallback() whenever sqlite3FaultSim() is called,

  159056.     ** if xCallback is not NULL.

  159057.     **

  159058.     ** As a test of the fault simulator mechanism itself, sqlite3FaultSim(0)

  159059.     ** is called immediately after installing the new callback and the return

  159060.     ** value from sqlite3FaultSim(0) becomes the return from

  159061.     ** sqlite3_test_control().

  159062.     */

  159063.     case SQLITE_TESTCTRL_FAULT_INSTALL: {

  159064.       /* MSVC is picky about pulling func ptrs from va lists.

  159065.       ** http://support.microsoft.com/kb/47961

  159066.       ** sqlite3GlobalConfig.xTestCallback = va_arg(ap, int(*)(int));

  159067.       */

  159068.       typedef int(*TESTCALLBACKFUNC_t)(int);

  159069.       sqlite3GlobalConfig.xTestCallback = va_arg(ap, TESTCALLBACKFUNC_t);

  159070.       rc = sqlite3FaultSim(0);

  159071.       break;

  159072.     }

  159073. 

  159074.     /*

  159075.     **  sqlite3_test_control(BENIGN_MALLOC_HOOKS, xBegin, xEnd)

  159076.     **

  159077.     ** Register hooks to call to indicate which malloc() failures 

  159078.     ** are benign.

  159079.     */

  159080.     case SQLITE_TESTCTRL_BENIGN_MALLOC_HOOKS: {

  159081.       typedef void (*void_function)(void);

  159082.       void_function xBenignBegin;

  159083.       void_function xBenignEnd;

  159084.       xBenignBegin = va_arg(ap, void_function);

  159085.       xBenignEnd = va_arg(ap, void_function);

  159086.       sqlite3BenignMallocHooks(xBenignBegin, xBenignEnd);

  159087.       break;

  159088.     }

  159089. 

  159090.     /*

  159091.     **  sqlite3_test_control(SQLITE_TESTCTRL_PENDING_BYTE, unsigned int X)

  159092.     **

  159093.     ** Set the PENDING byte to the value in the argument, if X>0.

  159094.     ** Make no changes if X==0.  Return the value of the pending byte

  159095.     ** as it existing before this routine was called.

  159096.     **

  159097.     ** IMPORTANT:  Changing the PENDING byte from 0x40000000 results in

  159098.     ** an incompatible database file format.  Changing the PENDING byte

  159099.     ** while any database connection is open results in undefined and

  159100.     ** deleterious behavior.

  159101.     */

  159102.     case SQLITE_TESTCTRL_PENDING_BYTE: {

  159103.       rc = PENDING_BYTE;

  159104. #ifndef SQLITE_OMIT_WSD

  159105.       {

  159106.         unsigned int newVal = va_arg(ap, unsigned int);

  159107.         if( newVal ) sqlite3PendingByte = newVal;

  159108.       }

  159109. #endif

  159110.       break;

  159111.     }

  159112. 

  159113.     /*

  159114.     **  sqlite3_test_control(SQLITE_TESTCTRL_ASSERT, int X)

  159115.     **

  159116.     ** This action provides a run-time test to see whether or not

  159117.     ** assert() was enabled at compile-time.  If X is true and assert()

  159118.     ** is enabled, then the return value is true.  If X is true and

  159119.     ** assert() is disabled, then the return value is zero.  If X is

  159120.     ** false and assert() is enabled, then the assertion fires and the

  159121.     ** process aborts.  If X is false and assert() is disabled, then the

  159122.     ** return value is zero.

  159123.     */

  159124.     case SQLITE_TESTCTRL_ASSERT: {

  159125.       volatile int x = 0;

  159126.       assert( /*side-effects-ok*/ (x = va_arg(ap,int))!=0 );

  159127.       rc = x;

  159128.       break;

  159129.     }

  159130. 

  159131. 

  159132.     /*

  159133.     **  sqlite3_test_control(SQLITE_TESTCTRL_ALWAYS, int X)

  159134.     **

  159135.     ** This action provides a run-time test to see how the ALWAYS and

  159136.     ** NEVER macros were defined at compile-time.

  159137.     **

  159138.     ** The return value is ALWAYS(X) if X is true, or 0 if X is false.

  159139.     **

  159140.     ** The recommended test is X==2.  If the return value is 2, that means

  159141.     ** ALWAYS() and NEVER() are both no-op pass-through macros, which is the

  159142.     ** default setting.  If the return value is 1, then ALWAYS() is either

  159143.     ** hard-coded to true or else it asserts if its argument is false.

  159144.     ** The first behavior (hard-coded to true) is the case if

  159145.     ** SQLITE_TESTCTRL_ASSERT shows that assert() is disabled and the second

  159146.     ** behavior (assert if the argument to ALWAYS() is false) is the case if

  159147.     ** SQLITE_TESTCTRL_ASSERT shows that assert() is enabled.

  159148.     **

  159149.     ** The run-time test procedure might look something like this:

  159150.     **

  159151.     **    if( sqlite3_test_control(SQLITE_TESTCTRL_ALWAYS, 2)==2 ){

  159152.     **      // ALWAYS() and NEVER() are no-op pass-through macros

  159153.     **    }else if( sqlite3_test_control(SQLITE_TESTCTRL_ASSERT, 1) ){

  159154.     **      // ALWAYS(x) asserts that x is true. NEVER(x) asserts x is false.

  159155.     **    }else{

  159156.     **      // ALWAYS(x) is a constant 1.  NEVER(x) is a constant 0.

  159157.     **    }

  159158.     */

  159159.     case SQLITE_TESTCTRL_ALWAYS: {

  159160.       int x = va_arg(ap,int);

  159161.       rc = x ? ALWAYS(x) : 0;

  159162.       break;

  159163.     }

  159164. 

  159165.     /*

  159166.     **   sqlite3_test_control(SQLITE_TESTCTRL_BYTEORDER);

  159167.     **

  159168.     ** The integer returned reveals the byte-order of the computer on which

  159169.     ** SQLite is running:

  159170.     **

  159171.     **       1     big-endian,    determined at run-time

  159172.     **      10     little-endian, determined at run-time

  159173.     **  432101     big-endian,    determined at compile-time

  159174.     **  123410     little-endian, determined at compile-time

  159175.     */ 

  159176.     case SQLITE_TESTCTRL_BYTEORDER: {

  159177.       rc = SQLITE_BYTEORDER*100 + SQLITE_LITTLEENDIAN*10 + SQLITE_BIGENDIAN;

  159178.       break;

  159179.     }

  159180. 

  159181.     /*   sqlite3_test_control(SQLITE_TESTCTRL_RESERVE, sqlite3 *db, int N)

  159182.     **

  159183.     ** Set the nReserve size to N for the main database on the database

  159184.     ** connection db.

  159185.     */

  159186.     case SQLITE_TESTCTRL_RESERVE: {

  159187.       sqlite3 *db = va_arg(ap, sqlite3*);

  159188.       int x = va_arg(ap,int);

  159189.       sqlite3_mutex_enter(db->mutex);

  159190.       sqlite3BtreeSetPageSize(db->aDb[0].pBt, 0, x, 0);

  159191.       sqlite3_mutex_leave(db->mutex);

  159192.       break;

  159193.     }

  159194. 

  159195.     /*  sqlite3_test_control(SQLITE_TESTCTRL_OPTIMIZATIONS, sqlite3 *db, int N)

  159196.     **

  159197.     ** Enable or disable various optimizations for testing purposes.  The 

  159198.     ** argument N is a bitmask of optimizations to be disabled.  For normal

  159199.     ** operation N should be 0.  The idea is that a test program (like the

  159200.     ** SQL Logic Test or SLT test module) can run the same SQL multiple times

  159201.     ** with various optimizations disabled to verify that the same answer

  159202.     ** is obtained in every case.

  159203.     */

  159204.     case SQLITE_TESTCTRL_OPTIMIZATIONS: {

  159205.       sqlite3 *db = va_arg(ap, sqlite3*);

  159206.       db->dbOptFlags = (u16)(va_arg(ap, int) & 0xffff);

  159207.       break;

  159208.     }

  159209. 

  159210.     /*   sqlite3_test_control(SQLITE_TESTCTRL_LOCALTIME_FAULT, int onoff);

  159211.     **

  159212.     ** If parameter onoff is non-zero, subsequent calls to localtime()

  159213.     ** and its variants fail. If onoff is zero, undo this setting.

  159214.     */

  159215.     case SQLITE_TESTCTRL_LOCALTIME_FAULT: {

  159216.       sqlite3GlobalConfig.bLocaltimeFault = va_arg(ap, int);

  159217.       break;

  159218.     }

  159219. 

  159220.     /*   sqlite3_test_control(SQLITE_TESTCTRL_INTERNAL_FUNCS, int onoff);

  159221.     **

  159222.     ** If parameter onoff is non-zero, internal-use-only SQL functions

  159223.     ** are visible to ordinary SQL.  This is useful for testing but is

  159224.     ** unsafe because invalid parameters to those internal-use-only functions

  159225.     ** can result in crashes or segfaults.

  159226.     */

  159227.     case SQLITE_TESTCTRL_INTERNAL_FUNCTIONS: {

  159228.       sqlite3GlobalConfig.bInternalFunctions = va_arg(ap, int);

  159229.       break;

  159230.     }

  159231. 

  159232.     /*   sqlite3_test_control(SQLITE_TESTCTRL_NEVER_CORRUPT, int);

  159233.     **

  159234.     ** Set or clear a flag that indicates that the database file is always well-

  159235.     ** formed and never corrupt.  This flag is clear by default, indicating that

  159236.     ** database files might have arbitrary corruption.  Setting the flag during

  159237.     ** testing causes certain assert() statements in the code to be activated

  159238.     ** that demonstrat invariants on well-formed database files.

  159239.     */

  159240.     case SQLITE_TESTCTRL_NEVER_CORRUPT: {

  159241.       sqlite3GlobalConfig.neverCorrupt = va_arg(ap, int);

  159242.       break;

  159243.     }

  159244. 

  159245.     /* Set the threshold at which OP_Once counters reset back to zero.

  159246.     ** By default this is 0x7ffffffe (over 2 billion), but that value is

  159247.     ** too big to test in a reasonable amount of time, so this control is

  159248.     ** provided to set a small and easily reachable reset value.

  159249.     */

  159250.     case SQLITE_TESTCTRL_ONCE_RESET_THRESHOLD: {

  159251.       sqlite3GlobalConfig.iOnceResetThreshold = va_arg(ap, int);

  159252.       break;

  159253.     }

  159254. 

  159255.     /*   sqlite3_test_control(SQLITE_TESTCTRL_VDBE_COVERAGE, xCallback, ptr);

  159256.     **

  159257.     ** Set the VDBE coverage callback function to xCallback with context 

  159258.     ** pointer ptr.

  159259.     */

  159260.     case SQLITE_TESTCTRL_VDBE_COVERAGE: {

  159261. #ifdef SQLITE_VDBE_COVERAGE

  159262.       typedef void (*branch_callback)(void*,unsigned int,

  159263.                                       unsigned char,unsigned char);

  159264.       sqlite3GlobalConfig.xVdbeBranch = va_arg(ap,branch_callback);

  159265.       sqlite3GlobalConfig.pVdbeBranchArg = va_arg(ap,void*);

  159266. #endif

  159267.       break;

  159268.     }

  159269. 

  159270.     /*   sqlite3_test_control(SQLITE_TESTCTRL_SORTER_MMAP, db, nMax); */

  159271.     case SQLITE_TESTCTRL_SORTER_MMAP: {

  159272.       sqlite3 *db = va_arg(ap, sqlite3*);

  159273.       db->nMaxSorterMmap = va_arg(ap, int);

  159274.       break;

  159275.     }

  159276. 

  159277.     /*   sqlite3_test_control(SQLITE_TESTCTRL_ISINIT);

  159278.     **

  159279.     ** Return SQLITE_OK if SQLite has been initialized and SQLITE_ERROR if

  159280.     ** not.

  159281.     */

  159282.     case SQLITE_TESTCTRL_ISINIT: {

  159283.       if( sqlite3GlobalConfig.isInit==0 ) rc = SQLITE_ERROR;

  159284.       break;

  159285.     }

  159286. 

  159287.     /*  sqlite3_test_control(SQLITE_TESTCTRL_IMPOSTER, db, dbName, onOff, tnum);

  159288.     **

  159289.     ** This test control is used to create imposter tables.  "db" is a pointer

  159290.     ** to the database connection.  dbName is the database name (ex: "main" or

  159291.     ** "temp") which will receive the imposter.  "onOff" turns imposter mode on

  159292.     ** or off.  "tnum" is the root page of the b-tree to which the imposter

  159293.     ** table should connect.

  159294.     **

  159295.     ** Enable imposter mode only when the schema has already been parsed.  Then

  159296.     ** run a single CREATE TABLE statement to construct the imposter table in

  159297.     ** the parsed schema.  Then turn imposter mode back off again.

  159298.     **

  159299.     ** If onOff==0 and tnum>0 then reset the schema for all databases, causing

  159300.     ** the schema to be reparsed the next time it is needed.  This has the

  159301.     ** effect of erasing all imposter tables.

  159302.     */

  159303.     case SQLITE_TESTCTRL_IMPOSTER: {

  159304.       sqlite3 *db = va_arg(ap, sqlite3*);

  159305.       sqlite3_mutex_enter(db->mutex);

  159306.       db->init.iDb = sqlite3FindDbName(db, va_arg(ap,const char*));

  159307.       db->init.busy = db->init.imposterTable = va_arg(ap,int);

  159308.       db->init.newTnum = va_arg(ap,int);

  159309.       if( db->init.busy==0 && db->init.newTnum>0 ){

  159310.         sqlite3ResetAllSchemasOfConnection(db);

  159311.       }

  159312.       sqlite3_mutex_leave(db->mutex);

  159313.       break;

  159314.     }

  159315. 

  159316. #if defined(YYCOVERAGE)

  159317.     /*  sqlite3_test_control(SQLITE_TESTCTRL_PARSER_COVERAGE, FILE *out)

  159318.     **

  159319.     ** This test control (only available when SQLite is compiled with

  159320.     ** -DYYCOVERAGE) writes a report onto "out" that shows all

  159321.     ** state/lookahead combinations in the parser state machine

  159322.     ** which are never exercised.  If any state is missed, make the

  159323.     ** return code SQLITE_ERROR.

  159324.     */

  159325.     case SQLITE_TESTCTRL_PARSER_COVERAGE: {

  159326.       FILE *out = va_arg(ap, FILE*);

  159327.       if( sqlite3ParserCoverage(out) ) rc = SQLITE_ERROR;

  159328.       break;

  159329.     }

  159330. #endif /* defined(YYCOVERAGE) */

  159331. 

  159332.     /*  sqlite3_test_control(SQLITE_TESTCTRL_RESULT_INTREAL, sqlite3_context*);

  159333.     **

  159334.     ** This test-control causes the most recent sqlite3_result_int64() value

  159335.     ** to be interpreted as a MEM_IntReal instead of as an MEM_Int.  Normally,

  159336.     ** MEM_IntReal values only arise during an INSERT operation of integer

  159337.     ** values into a REAL column, so they can be challenging to test.  This

  159338.     ** test-control enables us to write an intreal() SQL function that can

  159339.     ** inject an intreal() value at arbitrary places in an SQL statement,

  159340.     ** for testing purposes.

  159341.     */

  159342.     case SQLITE_TESTCTRL_RESULT_INTREAL: {

  159343.       sqlite3_context *pCtx = va_arg(ap, sqlite3_context*);

  159344.       sqlite3ResultIntReal(pCtx);

  159345.       break;

  159346.     }

  159347.   }

  159348.   va_end(ap);

  159349. #endif /* SQLITE_UNTESTABLE */

  159350.   return rc;

  159351. }

  159352. 

  159353. /*

  159354. ** This is a utility routine, useful to VFS implementations, that checks

  159355. ** to see if a database file was a URI that contained a specific query 

  159356. ** parameter, and if so obtains the value of the query parameter.

  159357. **

  159358. ** The zFilename argument is the filename pointer passed into the xOpen()

  159359. ** method of a VFS implementation.  The zParam argument is the name of the

  159360. ** query parameter we seek.  This routine returns the value of the zParam

  159361. ** parameter if it exists.  If the parameter does not exist, this routine

  159362. ** returns a NULL pointer.

  159363. */

  159364. SQLITE_API const char *sqlite3_uri_parameter(const char *zFilename, const char *zParam){

  159365.   if( zFilename==0 || zParam==0 ) return 0;

  159366.   zFilename += sqlite3Strlen30(zFilename) + 1;

  159367.   while( zFilename[0] ){

  159368.     int x = strcmp(zFilename, zParam);

  159369.     zFilename += sqlite3Strlen30(zFilename) + 1;

  159370.     if( x==0 ) return zFilename;

  159371.     zFilename += sqlite3Strlen30(zFilename) + 1;

  159372.   }

  159373.   return 0;

  159374. }

  159375. 

  159376. /*

  159377. ** Return a boolean value for a query parameter.

  159378. */

  159379. SQLITE_API int sqlite3_uri_boolean(const char *zFilename, const char *zParam, int bDflt){

  159380.   const char *z = sqlite3_uri_parameter(zFilename, zParam);

  159381.   bDflt = bDflt!=0;

  159382.   return z ? sqlite3GetBoolean(z, bDflt) : bDflt;

  159383. }

  159384. 

  159385. /*

  159386. ** Return a 64-bit integer value for a query parameter.

  159387. */

  159388. SQLITE_API sqlite3_int64 sqlite3_uri_int64(

  159389.   const char *zFilename,    /* Filename as passed to xOpen */

  159390.   const char *zParam,       /* URI parameter sought */

  159391.   sqlite3_int64 bDflt       /* return if parameter is missing */

  159392. ){

  159393.   const char *z = sqlite3_uri_parameter(zFilename, zParam);

  159394.   sqlite3_int64 v;

  159395.   if( z && sqlite3DecOrHexToI64(z, &v)==0 ){

  159396.     bDflt = v;

  159397.   }

  159398.   return bDflt;

  159399. }

  159400. 

  159401. /*

  159402. ** Return the Btree pointer identified by zDbName.  Return NULL if not found.

  159403. */

  159404. SQLITE_PRIVATE Btree *sqlite3DbNameToBtree(sqlite3 *db, const char *zDbName){

  159405.   int iDb = zDbName ? sqlite3FindDbName(db, zDbName) : 0;

  159406.   return iDb<0 ? 0 : db->aDb[iDb].pBt;

  159407. }

  159408. 

  159409. /*

  159410. ** Return the filename of the database associated with a database

  159411. ** connection.

  159412. */

  159413. SQLITE_API const char *sqlite3_db_filename(sqlite3 *db, const char *zDbName){

  159414.   Btree *pBt;

  159415. #ifdef SQLITE_ENABLE_API_ARMOR

  159416.   if( !sqlite3SafetyCheckOk(db) ){

  159417.     (void)SQLITE_MISUSE_BKPT;

  159418.     return 0;

  159419.   }

  159420. #endif

  159421.   pBt = sqlite3DbNameToBtree(db, zDbName);

  159422.   return pBt ? sqlite3BtreeGetFilename(pBt) : 0;

  159423. }

  159424. 

  159425. /*

  159426. ** Return 1 if database is read-only or 0 if read/write.  Return -1 if

  159427. ** no such database exists.

  159428. */

  159429. SQLITE_API int sqlite3_db_readonly(sqlite3 *db, const char *zDbName){

  159430.   Btree *pBt;

  159431. #ifdef SQLITE_ENABLE_API_ARMOR

  159432.   if( !sqlite3SafetyCheckOk(db) ){

  159433.     (void)SQLITE_MISUSE_BKPT;

  159434.     return -1;

  159435.   }

  159436. #endif

  159437.   pBt = sqlite3DbNameToBtree(db, zDbName);

  159438.   return pBt ? sqlite3BtreeIsReadonly(pBt) : -1;

  159439. }

  159440. 

  159441. #ifdef SQLITE_ENABLE_SNAPSHOT

  159442. /*

  159443. ** Obtain a snapshot handle for the snapshot of database zDb currently 

  159444. ** being read by handle db.

  159445. */

  159446. SQLITE_API int sqlite3_snapshot_get(

  159447.   sqlite3 *db, 

  159448.   const char *zDb,

  159449.   sqlite3_snapshot **ppSnapshot

  159450. ){

  159451.   int rc = SQLITE_ERROR;

  159452. #ifndef SQLITE_OMIT_WAL

  159453. 

  159454. #ifdef SQLITE_ENABLE_API_ARMOR

  159455.   if( !sqlite3SafetyCheckOk(db) ){

  159456.     return SQLITE_MISUSE_BKPT;

  159457.   }

  159458. #endif

  159459.   sqlite3_mutex_enter(db->mutex);

  159460. 

  159461.   if( db->autoCommit==0 ){

  159462.     int iDb = sqlite3FindDbName(db, zDb);

  159463.     if( iDb==0 || iDb>1 ){

  159464.       Btree *pBt = db->aDb[iDb].pBt;

  159465.       if( 0==sqlite3BtreeIsInTrans(pBt) ){

  159466.         rc = sqlite3BtreeBeginTrans(pBt, 0, 0);

  159467.         if( rc==SQLITE_OK ){

  159468.           rc = sqlite3PagerSnapshotGet(sqlite3BtreePager(pBt), ppSnapshot);

  159469.         }

  159470.       }

  159471.     }

  159472.   }

  159473. 

  159474.   sqlite3_mutex_leave(db->mutex);

  159475. #endif   /* SQLITE_OMIT_WAL */

  159476.   return rc;

  159477. }

  159478. 

  159479. /*

  159480. ** Open a read-transaction on the snapshot idendified by pSnapshot.

  159481. */

  159482. SQLITE_API int sqlite3_snapshot_open(

  159483.   sqlite3 *db, 

  159484.   const char *zDb, 

  159485.   sqlite3_snapshot *pSnapshot

  159486. ){

  159487.   int rc = SQLITE_ERROR;

  159488. #ifndef SQLITE_OMIT_WAL

  159489. 

  159490. #ifdef SQLITE_ENABLE_API_ARMOR

  159491.   if( !sqlite3SafetyCheckOk(db) ){

  159492.     return SQLITE_MISUSE_BKPT;

  159493.   }

  159494. #endif

  159495.   sqlite3_mutex_enter(db->mutex);

  159496.   if( db->autoCommit==0 ){

  159497.     int iDb;

  159498.     iDb = sqlite3FindDbName(db, zDb);

  159499.     if( iDb==0 || iDb>1 ){

  159500.       Btree *pBt = db->aDb[iDb].pBt;

  159501.       if( sqlite3BtreeIsInTrans(pBt)==0 ){

  159502.         Pager *pPager = sqlite3BtreePager(pBt);

  159503.         int bUnlock = 0;

  159504.         if( sqlite3BtreeIsInReadTrans(pBt) ){

  159505.           if( db->nVdbeActive==0 ){

  159506.             rc = sqlite3PagerSnapshotCheck(pPager, pSnapshot);

  159507.             if( rc==SQLITE_OK ){

  159508.               bUnlock = 1;

  159509.               rc = sqlite3BtreeCommit(pBt);

  159510.             }

  159511.           }

  159512.         }else{

  159513.           rc = SQLITE_OK;

  159514.         }

  159515.         if( rc==SQLITE_OK ){

  159516.           rc = sqlite3PagerSnapshotOpen(pPager, pSnapshot);

  159517.         }

  159518.         if( rc==SQLITE_OK ){

  159519.           rc = sqlite3BtreeBeginTrans(pBt, 0, 0);

  159520.           sqlite3PagerSnapshotOpen(pPager, 0);

  159521.         }

  159522.         if( bUnlock ){

  159523.           sqlite3PagerSnapshotUnlock(pPager);

  159524.         }

  159525.       }

  159526.     }

  159527.   }

  159528. 

  159529.   sqlite3_mutex_leave(db->mutex);

  159530. #endif   /* SQLITE_OMIT_WAL */

  159531.   return rc;

  159532. }

  159533. 

  159534. /*

  159535. ** Recover as many snapshots as possible from the wal file associated with

  159536. ** schema zDb of database db.

  159537. */

  159538. SQLITE_API int sqlite3_snapshot_recover(sqlite3 *db, const char *zDb){

  159539.   int rc = SQLITE_ERROR;

  159540.   int iDb;

  159541. #ifndef SQLITE_OMIT_WAL

  159542. 

  159543. #ifdef SQLITE_ENABLE_API_ARMOR

  159544.   if( !sqlite3SafetyCheckOk(db) ){

  159545.     return SQLITE_MISUSE_BKPT;

  159546.   }

  159547. #endif

  159548. 

  159549.   sqlite3_mutex_enter(db->mutex);

  159550.   iDb = sqlite3FindDbName(db, zDb);

  159551.   if( iDb==0 || iDb>1 ){

  159552.     Btree *pBt = db->aDb[iDb].pBt;

  159553.     if( 0==sqlite3BtreeIsInReadTrans(pBt) ){

  159554.       rc = sqlite3BtreeBeginTrans(pBt, 0, 0);

  159555.       if( rc==SQLITE_OK ){

  159556.         rc = sqlite3PagerSnapshotRecover(sqlite3BtreePager(pBt));

  159557.         sqlite3BtreeCommit(pBt);

  159558.       }

  159559.     }

  159560.   }

  159561.   sqlite3_mutex_leave(db->mutex);

  159562. #endif   /* SQLITE_OMIT_WAL */

  159563.   return rc;

  159564. }

  159565. 

  159566. /*

  159567. ** Free a snapshot handle obtained from sqlite3_snapshot_get().

  159568. */

  159569. SQLITE_API void sqlite3_snapshot_free(sqlite3_snapshot *pSnapshot){

  159570.   sqlite3_free(pSnapshot);

  159571. }

  159572. #endif /* SQLITE_ENABLE_SNAPSHOT */

  159573. 

  159574. #ifndef SQLITE_OMIT_COMPILEOPTION_DIAGS

  159575. /*

  159576. ** Given the name of a compile-time option, return true if that option

  159577. ** was used and false if not.

  159578. **

  159579. ** The name can optionally begin with "SQLITE_" but the "SQLITE_" prefix

  159580. ** is not required for a match.

  159581. */

  159582. SQLITE_API int sqlite3_compileoption_used(const char *zOptName){

  159583.   int i, n;

  159584.   int nOpt;

  159585.   const char **azCompileOpt;

  159586.  

  159587. #if SQLITE_ENABLE_API_ARMOR

  159588.   if( zOptName==0 ){

  159589.     (void)SQLITE_MISUSE_BKPT;

  159590.     return 0;

  159591.   }

  159592. #endif

  159593. 

  159594.   azCompileOpt = sqlite3CompileOptions(&nOpt);

  159595. 

  159596.   if( sqlite3StrNICmp(zOptName, "SQLITE_", 7)==0 ) zOptName += 7;

  159597.   n = sqlite3Strlen30(zOptName);

  159598. 

  159599.   /* Since nOpt is normally in single digits, a linear search is 

  159600.   ** adequate. No need for a binary search. */

  159601.   for(i=0; i<nOpt; i++){

  159602.     if( sqlite3StrNICmp(zOptName, azCompileOpt[i], n)==0

  159603.      && sqlite3IsIdChar((unsigned char)azCompileOpt[i][n])==0

  159604.     ){

  159605.       return 1;

  159606.     }

  159607.   }

  159608.   return 0;

  159609. }

  159610. 

  159611. /*

  159612. ** Return the N-th compile-time option string.  If N is out of range,

  159613. ** return a NULL pointer.

  159614. */

  159615. SQLITE_API const char *sqlite3_compileoption_get(int N){

  159616.   int nOpt;

  159617.   const char **azCompileOpt;

  159618.   azCompileOpt = sqlite3CompileOptions(&nOpt);

  159619.   if( N>=0 && N<nOpt ){

  159620.     return azCompileOpt[N];

  159621.   }

  159622.   return 0;

  159623. }

  159624. #endif /* SQLITE_OMIT_COMPILEOPTION_DIAGS */

  159625. 

  159626. /************** End of main.c ************************************************/

  159627. /************** Begin file notify.c ******************************************/

  159628. /*

  159629. ** 2009 March 3

  159630. **

  159631. ** The author disclaims copyright to this source code.  In place of

  159632. ** a legal notice, here is a blessing:

  159633. **

  159634. **    May you do good and not evil.

  159635. **    May you find forgiveness for yourself and forgive others.

  159636. **    May you share freely, never taking more than you give.

  159637. **

  159638. *************************************************************************

  159639. **

  159640. ** This file contains the implementation of the sqlite3_unlock_notify()

  159641. ** API method and its associated functionality.

  159642. */

  159643. /* #include "sqliteInt.h" */

  159644. /* #include "btreeInt.h" */

  159645. 

  159646. /* Omit this entire file if SQLITE_ENABLE_UNLOCK_NOTIFY is not defined. */

  159647. #ifdef SQLITE_ENABLE_UNLOCK_NOTIFY

  159648. 

  159649. /*

  159650. ** Public interfaces:

  159651. **

  159652. **   sqlite3ConnectionBlocked()

  159653. **   sqlite3ConnectionUnlocked()

  159654. **   sqlite3ConnectionClosed()

  159655. **   sqlite3_unlock_notify()

  159656. */

  159657. 

  159658. #define assertMutexHeld() \

  159659.   assert( sqlite3_mutex_held(sqlite3MutexAlloc(SQLITE_MUTEX_STATIC_MASTER)) )

  159660. 

  159661. /*

  159662. ** Head of a linked list of all sqlite3 objects created by this process

  159663. ** for which either sqlite3.pBlockingConnection or sqlite3.pUnlockConnection

  159664. ** is not NULL. This variable may only accessed while the STATIC_MASTER

  159665. ** mutex is held.

  159666. */

  159667. static sqlite3 *SQLITE_WSD sqlite3BlockedList = 0;

  159668. 

  159669. #ifndef NDEBUG

  159670. /*

  159671. ** This function is a complex assert() that verifies the following 

  159672. ** properties of the blocked connections list:

  159673. **

  159674. **   1) Each entry in the list has a non-NULL value for either 

  159675. **      pUnlockConnection or pBlockingConnection, or both.

  159676. **

  159677. **   2) All entries in the list that share a common value for 

  159678. **      xUnlockNotify are grouped together.

  159679. **

  159680. **   3) If the argument db is not NULL, then none of the entries in the

  159681. **      blocked connections list have pUnlockConnection or pBlockingConnection

  159682. **      set to db. This is used when closing connection db.

  159683. */

  159684. static void checkListProperties(sqlite3 *db){

  159685.   sqlite3 *p;

  159686.   for(p=sqlite3BlockedList; p; p=p->pNextBlocked){

  159687.     int seen = 0;

  159688.     sqlite3 *p2;

  159689. 

  159690.     /* Verify property (1) */

  159691.     assert( p->pUnlockConnection || p->pBlockingConnection );

  159692. 

  159693.     /* Verify property (2) */

  159694.     for(p2=sqlite3BlockedList; p2!=p; p2=p2->pNextBlocked){

  159695.       if( p2->xUnlockNotify==p->xUnlockNotify ) seen = 1;

  159696.       assert( p2->xUnlockNotify==p->xUnlockNotify || !seen );

  159697.       assert( db==0 || p->pUnlockConnection!=db );

  159698.       assert( db==0 || p->pBlockingConnection!=db );

  159699.     }

  159700.   }

  159701. }

  159702. #else

  159703. # define checkListProperties(x)

  159704. #endif

  159705. 

  159706. /*

  159707. ** Remove connection db from the blocked connections list. If connection

  159708. ** db is not currently a part of the list, this function is a no-op.

  159709. */

  159710. static void removeFromBlockedList(sqlite3 *db){

  159711.   sqlite3 **pp;

  159712.   assertMutexHeld();

  159713.   for(pp=&sqlite3BlockedList; *pp; pp = &(*pp)->pNextBlocked){

  159714.     if( *pp==db ){

  159715.       *pp = (*pp)->pNextBlocked;

  159716.       break;

  159717.     }

  159718.   }

  159719. }

  159720. 

  159721. /*

  159722. ** Add connection db to the blocked connections list. It is assumed

  159723. ** that it is not already a part of the list.

  159724. */

  159725. static void addToBlockedList(sqlite3 *db){

  159726.   sqlite3 **pp;

  159727.   assertMutexHeld();

  159728.   for(

  159729.     pp=&sqlite3BlockedList; 

  159730.     *pp && (*pp)->xUnlockNotify!=db->xUnlockNotify; 

  159731.     pp=&(*pp)->pNextBlocked

  159732.   );

  159733.   db->pNextBlocked = *pp;

  159734.   *pp = db;

  159735. }

  159736. 

  159737. /*

  159738. ** Obtain the STATIC_MASTER mutex.

  159739. */

  159740. static void enterMutex(void){

  159741.   sqlite3_mutex_enter(sqlite3MutexAlloc(SQLITE_MUTEX_STATIC_MASTER));

  159742.   checkListProperties(0);

  159743. }

  159744. 

  159745. /*

  159746. ** Release the STATIC_MASTER mutex.

  159747. */

  159748. static void leaveMutex(void){

  159749.   assertMutexHeld();

  159750.   checkListProperties(0);

  159751.   sqlite3_mutex_leave(sqlite3MutexAlloc(SQLITE_MUTEX_STATIC_MASTER));

  159752. }

  159753. 

  159754. /*

  159755. ** Register an unlock-notify callback.

  159756. **

  159757. ** This is called after connection "db" has attempted some operation

  159758. ** but has received an SQLITE_LOCKED error because another connection

  159759. ** (call it pOther) in the same process was busy using the same shared

  159760. ** cache.  pOther is found by looking at db->pBlockingConnection.

  159761. **

  159762. ** If there is no blocking connection, the callback is invoked immediately,

  159763. ** before this routine returns.

  159764. **

  159765. ** If pOther is already blocked on db, then report SQLITE_LOCKED, to indicate

  159766. ** a deadlock.

  159767. **

  159768. ** Otherwise, make arrangements to invoke xNotify when pOther drops

  159769. ** its locks.

  159770. **

  159771. ** Each call to this routine overrides any prior callbacks registered

  159772. ** on the same "db".  If xNotify==0 then any prior callbacks are immediately

  159773. ** cancelled.

  159774. */

  159775. SQLITE_API int sqlite3_unlock_notify(

  159776.   sqlite3 *db,

  159777.   void (*xNotify)(void **, int),

  159778.   void *pArg

  159779. ){

  159780.   int rc = SQLITE_OK;

  159781. 

  159782.   sqlite3_mutex_enter(db->mutex);

  159783.   enterMutex();

  159784. 

  159785.   if( xNotify==0 ){

  159786.     removeFromBlockedList(db);

  159787.     db->pBlockingConnection = 0;

  159788.     db->pUnlockConnection = 0;

  159789.     db->xUnlockNotify = 0;

  159790.     db->pUnlockArg = 0;

  159791.   }else if( 0==db->pBlockingConnection ){

  159792.     /* The blocking transaction has been concluded. Or there never was a 

  159793.     ** blocking transaction. In either case, invoke the notify callback

  159794.     ** immediately. 

  159795.     */

  159796.     xNotify(&pArg, 1);

  159797.   }else{

  159798.     sqlite3 *p;

  159799. 

  159800.     for(p=db->pBlockingConnection; p && p!=db; p=p->pUnlockConnection){}

  159801.     if( p ){

  159802.       rc = SQLITE_LOCKED;              /* Deadlock detected. */

  159803.     }else{

  159804.       db->pUnlockConnection = db->pBlockingConnection;

  159805.       db->xUnlockNotify = xNotify;

  159806.       db->pUnlockArg = pArg;

  159807.       removeFromBlockedList(db);

  159808.       addToBlockedList(db);

  159809.     }

  159810.   }

  159811. 

  159812.   leaveMutex();

  159813.   assert( !db->mallocFailed );

  159814.   sqlite3ErrorWithMsg(db, rc, (rc?"database is deadlocked":0));

  159815.   sqlite3_mutex_leave(db->mutex);

  159816.   return rc;

  159817. }

  159818. 

  159819. /*

  159820. ** This function is called while stepping or preparing a statement 

  159821. ** associated with connection db. The operation will return SQLITE_LOCKED

  159822. ** to the user because it requires a lock that will not be available

  159823. ** until connection pBlocker concludes its current transaction.

  159824. */

  159825. SQLITE_PRIVATE void sqlite3ConnectionBlocked(sqlite3 *db, sqlite3 *pBlocker){

  159826.   enterMutex();

  159827.   if( db->pBlockingConnection==0 && db->pUnlockConnection==0 ){

  159828.     addToBlockedList(db);

  159829.   }

  159830.   db->pBlockingConnection = pBlocker;

  159831.   leaveMutex();

  159832. }

  159833. 

  159834. /*

  159835. ** This function is called when

  159836. ** the transaction opened by database db has just finished. Locks held 

  159837. ** by database connection db have been released.

  159838. **

  159839. ** This function loops through each entry in the blocked connections

  159840. ** list and does the following:

  159841. **

  159842. **   1) If the sqlite3.pBlockingConnection member of a list entry is

  159843. **      set to db, then set pBlockingConnection=0.

  159844. **

  159845. **   2) If the sqlite3.pUnlockConnection member of a list entry is

  159846. **      set to db, then invoke the configured unlock-notify callback and

  159847. **      set pUnlockConnection=0.

  159848. **

  159849. **   3) If the two steps above mean that pBlockingConnection==0 and

  159850. **      pUnlockConnection==0, remove the entry from the blocked connections

  159851. **      list.

  159852. */

  159853. SQLITE_PRIVATE void sqlite3ConnectionUnlocked(sqlite3 *db){

  159854.   void (*xUnlockNotify)(void **, int) = 0; /* Unlock-notify cb to invoke */

  159855.   int nArg = 0;                            /* Number of entries in aArg[] */

  159856.   sqlite3 **pp;                            /* Iterator variable */

  159857.   void **aArg;               /* Arguments to the unlock callback */

  159858.   void **aDyn = 0;           /* Dynamically allocated space for aArg[] */

  159859.   void *aStatic[16];         /* Starter space for aArg[].  No malloc required */

  159860. 

  159861.   aArg = aStatic;

  159862.   enterMutex();         /* Enter STATIC_MASTER mutex */

  159863. 

  159864.   /* This loop runs once for each entry in the blocked-connections list. */

  159865.   for(pp=&sqlite3BlockedList; *pp; /* no-op */ ){

  159866.     sqlite3 *p = *pp;

  159867. 

  159868.     /* Step 1. */

  159869.     if( p->pBlockingConnection==db ){

  159870.       p->pBlockingConnection = 0;

  159871.     }

  159872. 

  159873.     /* Step 2. */

  159874.     if( p->pUnlockConnection==db ){

  159875.       assert( p->xUnlockNotify );

  159876.       if( p->xUnlockNotify!=xUnlockNotify && nArg!=0 ){

  159877.         xUnlockNotify(aArg, nArg);

  159878.         nArg = 0;

  159879.       }

  159880. 

  159881.       sqlite3BeginBenignMalloc();

  159882.       assert( aArg==aDyn || (aDyn==0 && aArg==aStatic) );

  159883.       assert( nArg<=(int)ArraySize(aStatic) || aArg==aDyn );

  159884.       if( (!aDyn && nArg==(int)ArraySize(aStatic))

  159885.        || (aDyn && nArg==(int)(sqlite3MallocSize(aDyn)/sizeof(void*)))

  159886.       ){

  159887.         /* The aArg[] array needs to grow. */

  159888.         void **pNew = (void **)sqlite3Malloc(nArg*sizeof(void *)*2);

  159889.         if( pNew ){

  159890.           memcpy(pNew, aArg, nArg*sizeof(void *));

  159891.           sqlite3_free(aDyn);

  159892.           aDyn = aArg = pNew;

  159893.         }else{

  159894.           /* This occurs when the array of context pointers that need to

  159895.           ** be passed to the unlock-notify callback is larger than the

  159896.           ** aStatic[] array allocated on the stack and the attempt to 

  159897.           ** allocate a larger array from the heap has failed.

  159898.           **

  159899.           ** This is a difficult situation to handle. Returning an error

  159900.           ** code to the caller is insufficient, as even if an error code

  159901.           ** is returned the transaction on connection db will still be

  159902.           ** closed and the unlock-notify callbacks on blocked connections

  159903.           ** will go unissued. This might cause the application to wait

  159904.           ** indefinitely for an unlock-notify callback that will never 

  159905.           ** arrive.

  159906.           **

  159907.           ** Instead, invoke the unlock-notify callback with the context

  159908.           ** array already accumulated. We can then clear the array and

  159909.           ** begin accumulating any further context pointers without 

  159910.           ** requiring any dynamic allocation. This is sub-optimal because

  159911.           ** it means that instead of one callback with a large array of

  159912.           ** context pointers the application will receive two or more

  159913.           ** callbacks with smaller arrays of context pointers, which will

  159914.           ** reduce the applications ability to prioritize multiple 

  159915.           ** connections. But it is the best that can be done under the

  159916.           ** circumstances.

  159917.           */

  159918.           xUnlockNotify(aArg, nArg);

  159919.           nArg = 0;

  159920.         }

  159921.       }

  159922.       sqlite3EndBenignMalloc();

  159923. 

  159924.       aArg[nArg++] = p->pUnlockArg;

  159925.       xUnlockNotify = p->xUnlockNotify;

  159926.       p->pUnlockConnection = 0;

  159927.       p->xUnlockNotify = 0;

  159928.       p->pUnlockArg = 0;

  159929.     }

  159930. 

  159931.     /* Step 3. */

  159932.     if( p->pBlockingConnection==0 && p->pUnlockConnection==0 ){

  159933.       /* Remove connection p from the blocked connections list. */

  159934.       *pp = p->pNextBlocked;

  159935.       p->pNextBlocked = 0;

  159936.     }else{

  159937.       pp = &p->pNextBlocked;

  159938.     }

  159939.   }

  159940. 

  159941.   if( nArg!=0 ){

  159942.     xUnlockNotify(aArg, nArg);

  159943.   }

  159944.   sqlite3_free(aDyn);

  159945.   leaveMutex();         /* Leave STATIC_MASTER mutex */

  159946. }

  159947. 

  159948. /*

  159949. ** This is called when the database connection passed as an argument is 

  159950. ** being closed. The connection is removed from the blocked list.

  159951. */

  159952. SQLITE_PRIVATE void sqlite3ConnectionClosed(sqlite3 *db){

  159953.   sqlite3ConnectionUnlocked(db);

  159954.   enterMutex();

  159955.   removeFromBlockedList(db);

  159956.   checkListProperties(db);

  159957.   leaveMutex();

  159958. }

  159959. #endif

  159960. 

  159961. /************** End of notify.c **********************************************/

  159962. /************** Begin file fts3.c ********************************************/

  159963. /*

  159964. ** 2006 Oct 10

  159965. **

  159966. ** The author disclaims copyright to this source code.  In place of

  159967. ** a legal notice, here is a blessing:

  159968. **

  159969. **    May you do good and not evil.

  159970. **    May you find forgiveness for yourself and forgive others.

  159971. **    May you share freely, never taking more than you give.

  159972. **

  159973. ******************************************************************************

  159974. **

  159975. ** This is an SQLite module implementing full-text search.

  159976. */

  159977. 

  159978. /*

  159979. ** The code in this file is only compiled if:

  159980. **

  159981. **     * The FTS3 module is being built as an extension

  159982. **       (in which case SQLITE_CORE is not defined), or

  159983. **

  159984. **     * The FTS3 module is being built into the core of

  159985. **       SQLite (in which case SQLITE_ENABLE_FTS3 is defined).

  159986. */

  159987. 

  159988. /* The full-text index is stored in a series of b+tree (-like)

  159989. ** structures called segments which map terms to doclists.  The

  159990. ** structures are like b+trees in layout, but are constructed from the

  159991. ** bottom up in optimal fashion and are not updatable.  Since trees

  159992. ** are built from the bottom up, things will be described from the

  159993. ** bottom up.

  159994. **

  159995. **

  159996. **** Varints ****

  159997. ** The basic unit of encoding is a variable-length integer called a

  159998. ** varint.  We encode variable-length integers in little-endian order

  159999. ** using seven bits * per byte as follows:

  160000. **

  160001. ** KEY:

  160002. **         A = 0xxxxxxx    7 bits of data and one flag bit

  160003. **         B = 1xxxxxxx    7 bits of data and one flag bit

  160004. **

  160005. **  7 bits - A

  160006. ** 14 bits - BA

  160007. ** 21 bits - BBA

  160008. ** and so on.

  160009. **

  160010. ** This is similar in concept to how sqlite encodes "varints" but

  160011. ** the encoding is not the same.  SQLite varints are big-endian

  160012. ** are are limited to 9 bytes in length whereas FTS3 varints are

  160013. ** little-endian and can be up to 10 bytes in length (in theory).

  160014. **

  160015. ** Example encodings:

  160016. **

  160017. **     1:    0x01

  160018. **   127:    0x7f

  160019. **   128:    0x81 0x00

  160020. **

  160021. **

  160022. **** Document lists ****

  160023. ** A doclist (document list) holds a docid-sorted list of hits for a

  160024. ** given term.  Doclists hold docids and associated token positions.

  160025. ** A docid is the unique integer identifier for a single document.

  160026. ** A position is the index of a word within the document.  The first 

  160027. ** word of the document has a position of 0.

  160028. **

  160029. ** FTS3 used to optionally store character offsets using a compile-time

  160030. ** option.  But that functionality is no longer supported.

  160031. **

  160032. ** A doclist is stored like this:

  160033. **

  160034. ** array {

  160035. **   varint docid;          (delta from previous doclist)

  160036. **   array {                (position list for column 0)

  160037. **     varint position;     (2 more than the delta from previous position)

  160038. **   }

  160039. **   array {

  160040. **     varint POS_COLUMN;   (marks start of position list for new column)

  160041. **     varint column;       (index of new column)

  160042. **     array {

  160043. **       varint position;   (2 more than the delta from previous position)

  160044. **     }

  160045. **   }

  160046. **   varint POS_END;        (marks end of positions for this document.

  160047. ** }

  160048. **

  160049. ** Here, array { X } means zero or more occurrences of X, adjacent in

  160050. ** memory.  A "position" is an index of a token in the token stream

  160051. ** generated by the tokenizer. Note that POS_END and POS_COLUMN occur 

  160052. ** in the same logical place as the position element, and act as sentinals

  160053. ** ending a position list array.  POS_END is 0.  POS_COLUMN is 1.

  160054. ** The positions numbers are not stored literally but rather as two more

  160055. ** than the difference from the prior position, or the just the position plus

  160056. ** 2 for the first position.  Example:

  160057. **

  160058. **   label:       A B C D E  F  G H   I  J K

  160059. **   value:     123 5 9 1 1 14 35 0 234 72 0

  160060. **

  160061. ** The 123 value is the first docid.  For column zero in this document

  160062. ** there are two matches at positions 3 and 10 (5-2 and 9-2+3).  The 1

  160063. ** at D signals the start of a new column; the 1 at E indicates that the

  160064. ** new column is column number 1.  There are two positions at 12 and 45

  160065. ** (14-2 and 35-2+12).  The 0 at H indicate the end-of-document.  The

  160066. ** 234 at I is the delta to next docid (357).  It has one position 70

  160067. ** (72-2) and then terminates with the 0 at K.

  160068. **

  160069. ** A "position-list" is the list of positions for multiple columns for

  160070. ** a single docid.  A "column-list" is the set of positions for a single

  160071. ** column.  Hence, a position-list consists of one or more column-lists,

  160072. ** a document record consists of a docid followed by a position-list and

  160073. ** a doclist consists of one or more document records.

  160074. **

  160075. ** A bare doclist omits the position information, becoming an 

  160076. ** array of varint-encoded docids.

  160077. **

  160078. **** Segment leaf nodes ****

  160079. ** Segment leaf nodes store terms and doclists, ordered by term.  Leaf

  160080. ** nodes are written using LeafWriter, and read using LeafReader (to

  160081. ** iterate through a single leaf node's data) and LeavesReader (to

  160082. ** iterate through a segment's entire leaf layer).  Leaf nodes have

  160083. ** the format:

  160084. **

  160085. ** varint iHeight;             (height from leaf level, always 0)

  160086. ** varint nTerm;               (length of first term)

  160087. ** char pTerm[nTerm];          (content of first term)

  160088. ** varint nDoclist;            (length of term's associated doclist)

  160089. ** char pDoclist[nDoclist];    (content of doclist)

  160090. ** array {

  160091. **                             (further terms are delta-encoded)

  160092. **   varint nPrefix;           (length of prefix shared with previous term)

  160093. **   varint nSuffix;           (length of unshared suffix)

  160094. **   char pTermSuffix[nSuffix];(unshared suffix of next term)

  160095. **   varint nDoclist;          (length of term's associated doclist)

  160096. **   char pDoclist[nDoclist];  (content of doclist)

  160097. ** }

  160098. **

  160099. ** Here, array { X } means zero or more occurrences of X, adjacent in

  160100. ** memory.

  160101. **

  160102. ** Leaf nodes are broken into blocks which are stored contiguously in

  160103. ** the %_segments table in sorted order.  This means that when the end

  160104. ** of a node is reached, the next term is in the node with the next

  160105. ** greater node id.

  160106. **

  160107. ** New data is spilled to a new leaf node when the current node

  160108. ** exceeds LEAF_MAX bytes (default 2048).  New data which itself is

  160109. ** larger than STANDALONE_MIN (default 1024) is placed in a standalone

  160110. ** node (a leaf node with a single term and doclist).  The goal of

  160111. ** these settings is to pack together groups of small doclists while

  160112. ** making it efficient to directly access large doclists.  The

  160113. ** assumption is that large doclists represent terms which are more

  160114. ** likely to be query targets.

  160115. **

  160116. ** TODO(shess) It may be useful for blocking decisions to be more

  160117. ** dynamic.  For instance, it may make more sense to have a 2.5k leaf

  160118. ** node rather than splitting into 2k and .5k nodes.  My intuition is

  160119. ** that this might extend through 2x or 4x the pagesize.

  160120. **

  160121. **

  160122. **** Segment interior nodes ****

  160123. ** Segment interior nodes store blockids for subtree nodes and terms

  160124. ** to describe what data is stored by the each subtree.  Interior

  160125. ** nodes are written using InteriorWriter, and read using

  160126. ** InteriorReader.  InteriorWriters are created as needed when

  160127. ** SegmentWriter creates new leaf nodes, or when an interior node

  160128. ** itself grows too big and must be split.  The format of interior

  160129. ** nodes:

  160130. **

  160131. ** varint iHeight;           (height from leaf level, always >0)

  160132. ** varint iBlockid;          (block id of node's leftmost subtree)

  160133. ** optional {

  160134. **   varint nTerm;           (length of first term)

  160135. **   char pTerm[nTerm];      (content of first term)

  160136. **   array {

  160137. **                                (further terms are delta-encoded)

  160138. **     varint nPrefix;            (length of shared prefix with previous term)

  160139. **     varint nSuffix;            (length of unshared suffix)

  160140. **     char pTermSuffix[nSuffix]; (unshared suffix of next term)

  160141. **   }

  160142. ** }

  160143. **

  160144. ** Here, optional { X } means an optional element, while array { X }

  160145. ** means zero or more occurrences of X, adjacent in memory.

  160146. **

  160147. ** An interior node encodes n terms separating n+1 subtrees.  The

  160148. ** subtree blocks are contiguous, so only the first subtree's blockid

  160149. ** is encoded.  The subtree at iBlockid will contain all terms less

  160150. ** than the first term encoded (or all terms if no term is encoded).

  160151. ** Otherwise, for terms greater than or equal to pTerm[i] but less

  160152. ** than pTerm[i+1], the subtree for that term will be rooted at

  160153. ** iBlockid+i.  Interior nodes only store enough term data to

  160154. ** distinguish adjacent children (if the rightmost term of the left

  160155. ** child is "something", and the leftmost term of the right child is

  160156. ** "wicked", only "w" is stored).

  160157. **

  160158. ** New data is spilled to a new interior node at the same height when

  160159. ** the current node exceeds INTERIOR_MAX bytes (default 2048).

  160160. ** INTERIOR_MIN_TERMS (default 7) keeps large terms from monopolizing

  160161. ** interior nodes and making the tree too skinny.  The interior nodes

  160162. ** at a given height are naturally tracked by interior nodes at

  160163. ** height+1, and so on.

  160164. **

  160165. **

  160166. **** Segment directory ****

  160167. ** The segment directory in table %_segdir stores meta-information for

  160168. ** merging and deleting segments, and also the root node of the

  160169. ** segment's tree.

  160170. **

  160171. ** The root node is the top node of the segment's tree after encoding

  160172. ** the entire segment, restricted to ROOT_MAX bytes (default 1024).

  160173. ** This could be either a leaf node or an interior node.  If the top

  160174. ** node requires more than ROOT_MAX bytes, it is flushed to %_segments

  160175. ** and a new root interior node is generated (which should always fit

  160176. ** within ROOT_MAX because it only needs space for 2 varints, the

  160177. ** height and the blockid of the previous root).

  160178. **

  160179. ** The meta-information in the segment directory is:

  160180. **   level               - segment level (see below)

  160181. **   idx                 - index within level

  160182. **                       - (level,idx uniquely identify a segment)

  160183. **   start_block         - first leaf node

  160184. **   leaves_end_block    - last leaf node

  160185. **   end_block           - last block (including interior nodes)

  160186. **   root                - contents of root node

  160187. **

  160188. ** If the root node is a leaf node, then start_block,

  160189. ** leaves_end_block, and end_block are all 0.

  160190. **

  160191. **

  160192. **** Segment merging ****

  160193. ** To amortize update costs, segments are grouped into levels and

  160194. ** merged in batches.  Each increase in level represents exponentially

  160195. ** more documents.

  160196. **

  160197. ** New documents (actually, document updates) are tokenized and

  160198. ** written individually (using LeafWriter) to a level 0 segment, with

  160199. ** incrementing idx.  When idx reaches MERGE_COUNT (default 16), all

  160200. ** level 0 segments are merged into a single level 1 segment.  Level 1

  160201. ** is populated like level 0, and eventually MERGE_COUNT level 1

  160202. ** segments are merged to a single level 2 segment (representing

  160203. ** MERGE_COUNT^2 updates), and so on.

  160204. **

  160205. ** A segment merge traverses all segments at a given level in

  160206. ** parallel, performing a straightforward sorted merge.  Since segment

  160207. ** leaf nodes are written in to the %_segments table in order, this

  160208. ** merge traverses the underlying sqlite disk structures efficiently.

  160209. ** After the merge, all segment blocks from the merged level are

  160210. ** deleted.

  160211. **

  160212. ** MERGE_COUNT controls how often we merge segments.  16 seems to be

  160213. ** somewhat of a sweet spot for insertion performance.  32 and 64 show

  160214. ** very similar performance numbers to 16 on insertion, though they're

  160215. ** a tiny bit slower (perhaps due to more overhead in merge-time

  160216. ** sorting).  8 is about 20% slower than 16, 4 about 50% slower than

  160217. ** 16, 2 about 66% slower than 16.

  160218. **

  160219. ** At query time, high MERGE_COUNT increases the number of segments

  160220. ** which need to be scanned and merged.  For instance, with 100k docs

  160221. ** inserted:

  160222. **

  160223. **    MERGE_COUNT   segments

  160224. **       16           25

  160225. **        8           12

  160226. **        4           10

  160227. **        2            6

  160228. **

  160229. ** This appears to have only a moderate impact on queries for very

  160230. ** frequent terms (which are somewhat dominated by segment merge

  160231. ** costs), and infrequent and non-existent terms still seem to be fast

  160232. ** even with many segments.

  160233. **

  160234. ** TODO(shess) That said, it would be nice to have a better query-side

  160235. ** argument for MERGE_COUNT of 16.  Also, it is possible/likely that

  160236. ** optimizations to things like doclist merging will swing the sweet

  160237. ** spot around.

  160238. **

  160239. **

  160240. **

  160241. **** Handling of deletions and updates ****

  160242. ** Since we're using a segmented structure, with no docid-oriented

  160243. ** index into the term index, we clearly cannot simply update the term

  160244. ** index when a document is deleted or updated.  For deletions, we

  160245. ** write an empty doclist (varint(docid) varint(POS_END)), for updates

  160246. ** we simply write the new doclist.  Segment merges overwrite older

  160247. ** data for a particular docid with newer data, so deletes or updates

  160248. ** will eventually overtake the earlier data and knock it out.  The

  160249. ** query logic likewise merges doclists so that newer data knocks out

  160250. ** older data.

  160251. */

  160252. 

  160253. /************** Include fts3Int.h in the middle of fts3.c ********************/

  160254. /************** Begin file fts3Int.h *****************************************/

  160255. /*

  160256. ** 2009 Nov 12

  160257. **

  160258. ** The author disclaims copyright to this source code.  In place of

  160259. ** a legal notice, here is a blessing:

  160260. **

  160261. **    May you do good and not evil.

  160262. **    May you find forgiveness for yourself and forgive others.

  160263. **    May you share freely, never taking more than you give.

  160264. **

  160265. ******************************************************************************

  160266. **

  160267. */

  160268. #ifndef _FTSINT_H

  160269. #define _FTSINT_H

  160270. 

  160271. #if !defined(NDEBUG) && !defined(SQLITE_DEBUG) 

  160272. # define NDEBUG 1

  160273. #endif

  160274. 

  160275. /* FTS3/FTS4 require virtual tables */

  160276. #ifdef SQLITE_OMIT_VIRTUALTABLE

  160277. # undef SQLITE_ENABLE_FTS3

  160278. # undef SQLITE_ENABLE_FTS4

  160279. #endif

  160280. 

  160281. /*

  160282. ** FTS4 is really an extension for FTS3.  It is enabled using the

  160283. ** SQLITE_ENABLE_FTS3 macro.  But to avoid confusion we also all

  160284. ** the SQLITE_ENABLE_FTS4 macro to serve as an alisse for SQLITE_ENABLE_FTS3.

  160285. */

  160286. #if defined(SQLITE_ENABLE_FTS4) && !defined(SQLITE_ENABLE_FTS3)

  160287. # define SQLITE_ENABLE_FTS3

  160288. #endif

  160289. 

  160290. #if !defined(SQLITE_CORE) || defined(SQLITE_ENABLE_FTS3)

  160291. 

  160292. /* If not building as part of the core, include sqlite3ext.h. */

  160293. #ifndef SQLITE_CORE

  160294. /* # include "sqlite3ext.h"  */

  160295. SQLITE_EXTENSION_INIT3

  160296. #endif

  160297. 

  160298. /* #include "sqlite3.h" */

  160299. /************** Include fts3_tokenizer.h in the middle of fts3Int.h **********/

  160300. /************** Begin file fts3_tokenizer.h **********************************/

  160301. /*

  160302. ** 2006 July 10

  160303. **

  160304. ** The author disclaims copyright to this source code.

  160305. **

  160306. *************************************************************************

  160307. ** Defines the interface to tokenizers used by fulltext-search.  There

  160308. ** are three basic components:

  160309. **

  160310. ** sqlite3_tokenizer_module is a singleton defining the tokenizer

  160311. ** interface functions.  This is essentially the class structure for

  160312. ** tokenizers.

  160313. **

  160314. ** sqlite3_tokenizer is used to define a particular tokenizer, perhaps

  160315. ** including customization information defined at creation time.

  160316. **

  160317. ** sqlite3_tokenizer_cursor is generated by a tokenizer to generate

  160318. ** tokens from a particular input.

  160319. */

  160320. #ifndef _FTS3_TOKENIZER_H_

  160321. #define _FTS3_TOKENIZER_H_

  160322. 

  160323. /* TODO(shess) Only used for SQLITE_OK and SQLITE_DONE at this time.

  160324. ** If tokenizers are to be allowed to call sqlite3_*() functions, then

  160325. ** we will need a way to register the API consistently.

  160326. */

  160327. /* #include "sqlite3.h" */

  160328. 

  160329. /*

  160330. ** Structures used by the tokenizer interface. When a new tokenizer

  160331. ** implementation is registered, the caller provides a pointer to

  160332. ** an sqlite3_tokenizer_module containing pointers to the callback

  160333. ** functions that make up an implementation.

  160334. **

  160335. ** When an fts3 table is created, it passes any arguments passed to

  160336. ** the tokenizer clause of the CREATE VIRTUAL TABLE statement to the

  160337. ** sqlite3_tokenizer_module.xCreate() function of the requested tokenizer

  160338. ** implementation. The xCreate() function in turn returns an 

  160339. ** sqlite3_tokenizer structure representing the specific tokenizer to

  160340. ** be used for the fts3 table (customized by the tokenizer clause arguments).

  160341. **

  160342. ** To tokenize an input buffer, the sqlite3_tokenizer_module.xOpen()

  160343. ** method is called. It returns an sqlite3_tokenizer_cursor object

  160344. ** that may be used to tokenize a specific input buffer based on

  160345. ** the tokenization rules supplied by a specific sqlite3_tokenizer

  160346. ** object.

  160347. */

  160348. typedef struct sqlite3_tokenizer_module sqlite3_tokenizer_module;

  160349. typedef struct sqlite3_tokenizer sqlite3_tokenizer;

  160350. typedef struct sqlite3_tokenizer_cursor sqlite3_tokenizer_cursor;

  160351. 

  160352. struct sqlite3_tokenizer_module {

  160353. 

  160354.   /*

  160355.   ** Structure version. Should always be set to 0 or 1.

  160356.   */

  160357.   int iVersion;

  160358. 

  160359.   /*

  160360.   ** Create a new tokenizer. The values in the argv[] array are the

  160361.   ** arguments passed to the "tokenizer" clause of the CREATE VIRTUAL

  160362.   ** TABLE statement that created the fts3 table. For example, if

  160363.   ** the following SQL is executed:

  160364.   **

  160365.   **   CREATE .. USING fts3( ... , tokenizer <tokenizer-name> arg1 arg2)

  160366.   **

  160367.   ** then argc is set to 2, and the argv[] array contains pointers

  160368.   ** to the strings "arg1" and "arg2".

  160369.   **

  160370.   ** This method should return either SQLITE_OK (0), or an SQLite error 

  160371.   ** code. If SQLITE_OK is returned, then *ppTokenizer should be set

  160372.   ** to point at the newly created tokenizer structure. The generic

  160373.   ** sqlite3_tokenizer.pModule variable should not be initialized by

  160374.   ** this callback. The caller will do so.

  160375.   */

  160376.   int (*xCreate)(

  160377.     int argc,                           /* Size of argv array */

  160378.     const char *const*argv,             /* Tokenizer argument strings */

  160379.     sqlite3_tokenizer **ppTokenizer     /* OUT: Created tokenizer */

  160380.   );

  160381. 

  160382.   /*

  160383.   ** Destroy an existing tokenizer. The fts3 module calls this method

  160384.   ** exactly once for each successful call to xCreate().

  160385.   */

  160386.   int (*xDestroy)(sqlite3_tokenizer *pTokenizer);

  160387. 

  160388.   /*

  160389.   ** Create a tokenizer cursor to tokenize an input buffer. The caller

  160390.   ** is responsible for ensuring that the input buffer remains valid

  160391.   ** until the cursor is closed (using the xClose() method). 

  160392.   */

  160393.   int (*xOpen)(

  160394.     sqlite3_tokenizer *pTokenizer,       /* Tokenizer object */

  160395.     const char *pInput, int nBytes,      /* Input buffer */

  160396.     sqlite3_tokenizer_cursor **ppCursor  /* OUT: Created tokenizer cursor */

  160397.   );

  160398. 

  160399.   /*

  160400.   ** Destroy an existing tokenizer cursor. The fts3 module calls this 

  160401.   ** method exactly once for each successful call to xOpen().

  160402.   */

  160403.   int (*xClose)(sqlite3_tokenizer_cursor *pCursor);

  160404. 

  160405.   /*

  160406.   ** Retrieve the next token from the tokenizer cursor pCursor. This

  160407.   ** method should either return SQLITE_OK and set the values of the

  160408.   ** "OUT" variables identified below, or SQLITE_DONE to indicate that

  160409.   ** the end of the buffer has been reached, or an SQLite error code.

  160410.   **

  160411.   ** *ppToken should be set to point at a buffer containing the 

  160412.   ** normalized version of the token (i.e. after any case-folding and/or

  160413.   ** stemming has been performed). *pnBytes should be set to the length

  160414.   ** of this buffer in bytes. The input text that generated the token is

  160415.   ** identified by the byte offsets returned in *piStartOffset and

  160416.   ** *piEndOffset. *piStartOffset should be set to the index of the first

  160417.   ** byte of the token in the input buffer. *piEndOffset should be set

  160418.   ** to the index of the first byte just past the end of the token in

  160419.   ** the input buffer.

  160420.   **

  160421.   ** The buffer *ppToken is set to point at is managed by the tokenizer

  160422.   ** implementation. It is only required to be valid until the next call

  160423.   ** to xNext() or xClose(). 

  160424.   */

  160425.   /* TODO(shess) current implementation requires pInput to be

  160426.   ** nul-terminated.  This should either be fixed, or pInput/nBytes

  160427.   ** should be converted to zInput.

  160428.   */

  160429.   int (*xNext)(

  160430.     sqlite3_tokenizer_cursor *pCursor,   /* Tokenizer cursor */

  160431.     const char **ppToken, int *pnBytes,  /* OUT: Normalized text for token */

  160432.     int *piStartOffset,  /* OUT: Byte offset of token in input buffer */

  160433.     int *piEndOffset,    /* OUT: Byte offset of end of token in input buffer */

  160434.     int *piPosition      /* OUT: Number of tokens returned before this one */

  160435.   );

  160436. 

  160437.   /***********************************************************************

  160438.   ** Methods below this point are only available if iVersion>=1.

  160439.   */

  160440. 

  160441.   /* 

  160442.   ** Configure the language id of a tokenizer cursor.

  160443.   */

  160444.   int (*xLanguageid)(sqlite3_tokenizer_cursor *pCsr, int iLangid);

  160445. };

  160446. 

  160447. struct sqlite3_tokenizer {

  160448.   const sqlite3_tokenizer_module *pModule;  /* The module for this tokenizer */

  160449.   /* Tokenizer implementations will typically add additional fields */

  160450. };

  160451. 

  160452. struct sqlite3_tokenizer_cursor {

  160453.   sqlite3_tokenizer *pTokenizer;       /* Tokenizer for this cursor. */

  160454.   /* Tokenizer implementations will typically add additional fields */

  160455. };

  160456. 

  160457. int fts3_global_term_cnt(int iTerm, int iCol);

  160458. int fts3_term_cnt(int iTerm, int iCol);

  160459. 

  160460. 

  160461. #endif /* _FTS3_TOKENIZER_H_ */

  160462. 

  160463. /************** End of fts3_tokenizer.h **************************************/

  160464. /************** Continuing where we left off in fts3Int.h ********************/

  160465. /************** Include fts3_hash.h in the middle of fts3Int.h ***************/

  160466. /************** Begin file fts3_hash.h ***************************************/

  160467. /*

  160468. ** 2001 September 22

  160469. **

  160470. ** The author disclaims copyright to this source code.  In place of

  160471. ** a legal notice, here is a blessing:

  160472. **

  160473. **    May you do good and not evil.

  160474. **    May you find forgiveness for yourself and forgive others.

  160475. **    May you share freely, never taking more than you give.

  160476. **

  160477. *************************************************************************

  160478. ** This is the header file for the generic hash-table implementation

  160479. ** used in SQLite.  We've modified it slightly to serve as a standalone

  160480. ** hash table implementation for the full-text indexing module.

  160481. **

  160482. */

  160483. #ifndef _FTS3_HASH_H_

  160484. #define _FTS3_HASH_H_

  160485. 

  160486. /* Forward declarations of structures. */

  160487. typedef struct Fts3Hash Fts3Hash;

  160488. typedef struct Fts3HashElem Fts3HashElem;

  160489. 

  160490. /* A complete hash table is an instance of the following structure.

  160491. ** The internals of this structure are intended to be opaque -- client

  160492. ** code should not attempt to access or modify the fields of this structure

  160493. ** directly.  Change this structure only by using the routines below.

  160494. ** However, many of the "procedures" and "functions" for modifying and

  160495. ** accessing this structure are really macros, so we can't really make

  160496. ** this structure opaque.

  160497. */

  160498. struct Fts3Hash {

  160499.   char keyClass;          /* HASH_INT, _POINTER, _STRING, _BINARY */

  160500.   char copyKey;           /* True if copy of key made on insert */

  160501.   int count;              /* Number of entries in this table */

  160502.   Fts3HashElem *first;    /* The first element of the array */

  160503.   int htsize;             /* Number of buckets in the hash table */

  160504.   struct _fts3ht {        /* the hash table */

  160505.     int count;               /* Number of entries with this hash */

  160506.     Fts3HashElem *chain;     /* Pointer to first entry with this hash */

  160507.   } *ht;

  160508. };

  160509. 

  160510. /* Each element in the hash table is an instance of the following 

  160511. ** structure.  All elements are stored on a single doubly-linked list.

  160512. **

  160513. ** Again, this structure is intended to be opaque, but it can't really

  160514. ** be opaque because it is used by macros.

  160515. */

  160516. struct Fts3HashElem {

  160517.   Fts3HashElem *next, *prev; /* Next and previous elements in the table */

  160518.   void *data;                /* Data associated with this element */

  160519.   void *pKey; int nKey;      /* Key associated with this element */

  160520. };

  160521. 

  160522. /*

  160523. ** There are 2 different modes of operation for a hash table:

  160524. **

  160525. **   FTS3_HASH_STRING        pKey points to a string that is nKey bytes long

  160526. **                           (including the null-terminator, if any).  Case

  160527. **                           is respected in comparisons.

  160528. **

  160529. **   FTS3_HASH_BINARY        pKey points to binary data nKey bytes long. 

  160530. **                           memcmp() is used to compare keys.

  160531. **

  160532. ** A copy of the key is made if the copyKey parameter to fts3HashInit is 1.  

  160533. */

  160534. #define FTS3_HASH_STRING    1

  160535. #define FTS3_HASH_BINARY    2

  160536. 

  160537. /*

  160538. ** Access routines.  To delete, insert a NULL pointer.

  160539. */

  160540. SQLITE_PRIVATE void sqlite3Fts3HashInit(Fts3Hash *pNew, char keyClass, char copyKey);

  160541. SQLITE_PRIVATE void *sqlite3Fts3HashInsert(Fts3Hash*, const void *pKey, int nKey, void *pData);

  160542. SQLITE_PRIVATE void *sqlite3Fts3HashFind(const Fts3Hash*, const void *pKey, int nKey);

  160543. SQLITE_PRIVATE void sqlite3Fts3HashClear(Fts3Hash*);

  160544. SQLITE_PRIVATE Fts3HashElem *sqlite3Fts3HashFindElem(const Fts3Hash *, const void *, int);

  160545. 

  160546. /*

  160547. ** Shorthand for the functions above

  160548. */

  160549. #define fts3HashInit     sqlite3Fts3HashInit

  160550. #define fts3HashInsert   sqlite3Fts3HashInsert

  160551. #define fts3HashFind     sqlite3Fts3HashFind

  160552. #define fts3HashClear    sqlite3Fts3HashClear

  160553. #define fts3HashFindElem sqlite3Fts3HashFindElem

  160554. 

  160555. /*

  160556. ** Macros for looping over all elements of a hash table.  The idiom is

  160557. ** like this:

  160558. **

  160559. **   Fts3Hash h;

  160560. **   Fts3HashElem *p;

  160561. **   ...

  160562. **   for(p=fts3HashFirst(&h); p; p=fts3HashNext(p)){

  160563. **     SomeStructure *pData = fts3HashData(p);

  160564. **     // do something with pData

  160565. **   }

  160566. */

  160567. #define fts3HashFirst(H)  ((H)->first)

  160568. #define fts3HashNext(E)   ((E)->next)

  160569. #define fts3HashData(E)   ((E)->data)

  160570. #define fts3HashKey(E)    ((E)->pKey)

  160571. #define fts3HashKeysize(E) ((E)->nKey)

  160572. 

  160573. /*

  160574. ** Number of entries in a hash table

  160575. */

  160576. #define fts3HashCount(H)  ((H)->count)

  160577. 

  160578. #endif /* _FTS3_HASH_H_ */

  160579. 

  160580. /************** End of fts3_hash.h *******************************************/

  160581. /************** Continuing where we left off in fts3Int.h ********************/

  160582. 

  160583. /*

  160584. ** This constant determines the maximum depth of an FTS expression tree

  160585. ** that the library will create and use. FTS uses recursion to perform 

  160586. ** various operations on the query tree, so the disadvantage of a large

  160587. ** limit is that it may allow very large queries to use large amounts

  160588. ** of stack space (perhaps causing a stack overflow).

  160589. */

  160590. #ifndef SQLITE_FTS3_MAX_EXPR_DEPTH

  160591. # define SQLITE_FTS3_MAX_EXPR_DEPTH 12

  160592. #endif

  160593. 

  160594. 

  160595. /*

  160596. ** This constant controls how often segments are merged. Once there are

  160597. ** FTS3_MERGE_COUNT segments of level N, they are merged into a single

  160598. ** segment of level N+1.

  160599. */

  160600. #define FTS3_MERGE_COUNT 16

  160601. 

  160602. /*

  160603. ** This is the maximum amount of data (in bytes) to store in the 

  160604. ** Fts3Table.pendingTerms hash table. Normally, the hash table is

  160605. ** populated as documents are inserted/updated/deleted in a transaction

  160606. ** and used to create a new segment when the transaction is committed.

  160607. ** However if this limit is reached midway through a transaction, a new 

  160608. ** segment is created and the hash table cleared immediately.

  160609. */

  160610. #define FTS3_MAX_PENDING_DATA (1*1024*1024)

  160611. 

  160612. /*

  160613. ** Macro to return the number of elements in an array. SQLite has a

  160614. ** similar macro called ArraySize(). Use a different name to avoid

  160615. ** a collision when building an amalgamation with built-in FTS3.

  160616. */

  160617. #define SizeofArray(X) ((int)(sizeof(X)/sizeof(X[0])))

  160618. 

  160619. 

  160620. #ifndef MIN

  160621. # define MIN(x,y) ((x)<(y)?(x):(y))

  160622. #endif

  160623. #ifndef MAX

  160624. # define MAX(x,y) ((x)>(y)?(x):(y))

  160625. #endif

  160626. 

  160627. /*

  160628. ** Maximum length of a varint encoded integer. The varint format is different

  160629. ** from that used by SQLite, so the maximum length is 10, not 9.

  160630. */

  160631. #define FTS3_VARINT_MAX 10

  160632. 

  160633. #define FTS3_BUFFER_PADDING 8

  160634. 

  160635. /*

  160636. ** FTS4 virtual tables may maintain multiple indexes - one index of all terms

  160637. ** in the document set and zero or more prefix indexes. All indexes are stored

  160638. ** as one or more b+-trees in the %_segments and %_segdir tables. 

  160639. **

  160640. ** It is possible to determine which index a b+-tree belongs to based on the

  160641. ** value stored in the "%_segdir.level" column. Given this value L, the index

  160642. ** that the b+-tree belongs to is (L<<10). In other words, all b+-trees with

  160643. ** level values between 0 and 1023 (inclusive) belong to index 0, all levels

  160644. ** between 1024 and 2047 to index 1, and so on.

  160645. **

  160646. ** It is considered impossible for an index to use more than 1024 levels. In 

  160647. ** theory though this may happen, but only after at least 

  160648. ** (FTS3_MERGE_COUNT^1024) separate flushes of the pending-terms tables.

  160649. */

  160650. #define FTS3_SEGDIR_MAXLEVEL      1024

  160651. #define FTS3_SEGDIR_MAXLEVEL_STR "1024"

  160652. 

  160653. /*

  160654. ** The testcase() macro is only used by the amalgamation.  If undefined,

  160655. ** make it a no-op.

  160656. */

  160657. #ifndef testcase

  160658. # define testcase(X)

  160659. #endif

  160660. 

  160661. /*

  160662. ** Terminator values for position-lists and column-lists.

  160663. */

  160664. #define POS_COLUMN  (1)     /* Column-list terminator */

  160665. #define POS_END     (0)     /* Position-list terminator */ 

  160666. 

  160667. /*

  160668. ** The assert_fts3_nc() macro is similar to the assert() macro, except that it

  160669. ** is used for assert() conditions that are true only if it can be 

  160670. ** guranteed that the database is not corrupt.

  160671. */

  160672. #if defined(SQLITE_DEBUG) || defined(SQLITE_TEST)

  160673. SQLITE_API extern int sqlite3_fts3_may_be_corrupt;

  160674. # define assert_fts3_nc(x) assert(sqlite3_fts3_may_be_corrupt || (x))

  160675. #else

  160676. # define assert_fts3_nc(x) assert(x)

  160677. #endif

  160678. 

  160679. /*

  160680. ** This section provides definitions to allow the

  160681. ** FTS3 extension to be compiled outside of the 

  160682. ** amalgamation.

  160683. */

  160684. #ifndef SQLITE_AMALGAMATION

  160685. /*

  160686. ** Macros indicating that conditional expressions are always true or

  160687. ** false.

  160688. */

  160689. #ifdef SQLITE_COVERAGE_TEST

  160690. # define ALWAYS(x) (1)

  160691. # define NEVER(X)  (0)

  160692. #elif defined(SQLITE_DEBUG)

  160693. # define ALWAYS(x) sqlite3Fts3Always((x)!=0)

  160694. # define NEVER(x) sqlite3Fts3Never((x)!=0)

  160695. SQLITE_PRIVATE int sqlite3Fts3Always(int b);

  160696. SQLITE_PRIVATE int sqlite3Fts3Never(int b);

  160697. #else

  160698. # define ALWAYS(x) (x)

  160699. # define NEVER(x)  (x)

  160700. #endif

  160701. 

  160702. /*

  160703. ** Internal types used by SQLite.

  160704. */

  160705. typedef unsigned char u8;         /* 1-byte (or larger) unsigned integer */

  160706. typedef short int i16;            /* 2-byte (or larger) signed integer */

  160707. typedef unsigned int u32;         /* 4-byte unsigned integer */

  160708. typedef sqlite3_uint64 u64;       /* 8-byte unsigned integer */

  160709. typedef sqlite3_int64 i64;        /* 8-byte signed integer */

  160710. 

  160711. /*

  160712. ** Macro used to suppress compiler warnings for unused parameters.

  160713. */

  160714. #define UNUSED_PARAMETER(x) (void)(x)

  160715. 

  160716. /*

  160717. ** Activate assert() only if SQLITE_TEST is enabled.

  160718. */

  160719. #if !defined(NDEBUG) && !defined(SQLITE_DEBUG) 

  160720. # define NDEBUG 1

  160721. #endif

  160722. 

  160723. /*

  160724. ** The TESTONLY macro is used to enclose variable declarations or

  160725. ** other bits of code that are needed to support the arguments

  160726. ** within testcase() and assert() macros.

  160727. */

  160728. #if defined(SQLITE_DEBUG) || defined(SQLITE_COVERAGE_TEST)

  160729. # define TESTONLY(X)  X

  160730. #else

  160731. # define TESTONLY(X)

  160732. #endif

  160733. 

  160734. #endif /* SQLITE_AMALGAMATION */

  160735. 

  160736. #ifdef SQLITE_DEBUG

  160737. SQLITE_PRIVATE int sqlite3Fts3Corrupt(void);

  160738. # define FTS_CORRUPT_VTAB sqlite3Fts3Corrupt()

  160739. #else

  160740. # define FTS_CORRUPT_VTAB SQLITE_CORRUPT_VTAB

  160741. #endif

  160742. 

  160743. typedef struct Fts3Table Fts3Table;

  160744. typedef struct Fts3Cursor Fts3Cursor;

  160745. typedef struct Fts3Expr Fts3Expr;

  160746. typedef struct Fts3Phrase Fts3Phrase;

  160747. typedef struct Fts3PhraseToken Fts3PhraseToken;

  160748. 

  160749. typedef struct Fts3Doclist Fts3Doclist;

  160750. typedef struct Fts3SegFilter Fts3SegFilter;

  160751. typedef struct Fts3DeferredToken Fts3DeferredToken;

  160752. typedef struct Fts3SegReader Fts3SegReader;

  160753. typedef struct Fts3MultiSegReader Fts3MultiSegReader;

  160754. 

  160755. typedef struct MatchinfoBuffer MatchinfoBuffer;

  160756. 

  160757. /*

  160758. ** A connection to a fulltext index is an instance of the following

  160759. ** structure. The xCreate and xConnect methods create an instance

  160760. ** of this structure and xDestroy and xDisconnect free that instance.

  160761. ** All other methods receive a pointer to the structure as one of their

  160762. ** arguments.

  160763. */

  160764. struct Fts3Table {

  160765.   sqlite3_vtab base;              /* Base class used by SQLite core */

  160766.   sqlite3 *db;                    /* The database connection */

  160767.   const char *zDb;                /* logical database name */

  160768.   const char *zName;              /* virtual table name */

  160769.   int nColumn;                    /* number of named columns in virtual table */

  160770.   char **azColumn;                /* column names.  malloced */

  160771.   u8 *abNotindexed;               /* True for 'notindexed' columns */

  160772.   sqlite3_tokenizer *pTokenizer;  /* tokenizer for inserts and queries */

  160773.   char *zContentTbl;              /* content=xxx option, or NULL */

  160774.   char *zLanguageid;              /* languageid=xxx option, or NULL */

  160775.   int nAutoincrmerge;             /* Value configured by 'automerge' */

  160776.   u32 nLeafAdd;                   /* Number of leaf blocks added this trans */

  160777. 

  160778.   /* Precompiled statements used by the implementation. Each of these 

  160779.   ** statements is run and reset within a single virtual table API call. 

  160780.   */

  160781.   sqlite3_stmt *aStmt[40];

  160782.   sqlite3_stmt *pSeekStmt;        /* Cache for fts3CursorSeekStmt() */

  160783. 

  160784.   char *zReadExprlist;

  160785.   char *zWriteExprlist;

  160786. 

  160787.   int nNodeSize;                  /* Soft limit for node size */

  160788.   u8 bFts4;                       /* True for FTS4, false for FTS3 */

  160789.   u8 bHasStat;                    /* True if %_stat table exists (2==unknown) */

  160790.   u8 bHasDocsize;                 /* True if %_docsize table exists */

  160791.   u8 bDescIdx;                    /* True if doclists are in reverse order */

  160792.   u8 bIgnoreSavepoint;            /* True to ignore xSavepoint invocations */

  160793.   int nPgsz;                      /* Page size for host database */

  160794.   char *zSegmentsTbl;             /* Name of %_segments table */

  160795.   sqlite3_blob *pSegments;        /* Blob handle open on %_segments table */

  160796. 

  160797.   /* 

  160798.   ** The following array of hash tables is used to buffer pending index 

  160799.   ** updates during transactions. All pending updates buffered at any one

  160800.   ** time must share a common language-id (see the FTS4 langid= feature).

  160801.   ** The current language id is stored in variable iPrevLangid.

  160802.   **

  160803.   ** A single FTS4 table may have multiple full-text indexes. For each index

  160804.   ** there is an entry in the aIndex[] array. Index 0 is an index of all the

  160805.   ** terms that appear in the document set. Each subsequent index in aIndex[]

  160806.   ** is an index of prefixes of a specific length.

  160807.   **

  160808.   ** Variable nPendingData contains an estimate the memory consumed by the 

  160809.   ** pending data structures, including hash table overhead, but not including

  160810.   ** malloc overhead.  When nPendingData exceeds nMaxPendingData, all hash

  160811.   ** tables are flushed to disk. Variable iPrevDocid is the docid of the most 

  160812.   ** recently inserted record.

  160813.   */

  160814.   int nIndex;                     /* Size of aIndex[] */

  160815.   struct Fts3Index {

  160816.     int nPrefix;                  /* Prefix length (0 for main terms index) */

  160817.     Fts3Hash hPending;            /* Pending terms table for this index */

  160818.   } *aIndex;

  160819.   int nMaxPendingData;            /* Max pending data before flush to disk */

  160820.   int nPendingData;               /* Current bytes of pending data */

  160821.   sqlite_int64 iPrevDocid;        /* Docid of most recently inserted document */

  160822.   int iPrevLangid;                /* Langid of recently inserted document */

  160823.   int bPrevDelete;                /* True if last operation was a delete */

  160824. 

  160825. #if defined(SQLITE_DEBUG) || defined(SQLITE_COVERAGE_TEST)

  160826.   /* State variables used for validating that the transaction control

  160827.   ** methods of the virtual table are called at appropriate times.  These

  160828.   ** values do not contribute to FTS functionality; they are used for

  160829.   ** verifying the operation of the SQLite core.

  160830.   */

  160831.   int inTransaction;     /* True after xBegin but before xCommit/xRollback */

  160832.   int mxSavepoint;       /* Largest valid xSavepoint integer */

  160833. #endif

  160834. 

  160835. #ifdef SQLITE_TEST

  160836.   /* True to disable the incremental doclist optimization. This is controled

  160837.   ** by special insert command 'test-no-incr-doclist'.  */

  160838.   int bNoIncrDoclist;

  160839. #endif

  160840. };

  160841. 

  160842. /*

  160843. ** When the core wants to read from the virtual table, it creates a

  160844. ** virtual table cursor (an instance of the following structure) using

  160845. ** the xOpen method. Cursors are destroyed using the xClose method.

  160846. */

  160847. struct Fts3Cursor {

  160848.   sqlite3_vtab_cursor base;       /* Base class used by SQLite core */

  160849.   i16 eSearch;                    /* Search strategy (see below) */

  160850.   u8 isEof;                       /* True if at End Of Results */

  160851.   u8 isRequireSeek;               /* True if must seek pStmt to %_content row */

  160852.   u8 bSeekStmt;                   /* True if pStmt is a seek */

  160853.   sqlite3_stmt *pStmt;            /* Prepared statement in use by the cursor */

  160854.   Fts3Expr *pExpr;                /* Parsed MATCH query string */

  160855.   int iLangid;                    /* Language being queried for */

  160856.   int nPhrase;                    /* Number of matchable phrases in query */

  160857.   Fts3DeferredToken *pDeferred;   /* Deferred search tokens, if any */

  160858.   sqlite3_int64 iPrevId;          /* Previous id read from aDoclist */

  160859.   char *pNextId;                  /* Pointer into the body of aDoclist */

  160860.   char *aDoclist;                 /* List of docids for full-text queries */

  160861.   int nDoclist;                   /* Size of buffer at aDoclist */

  160862.   u8 bDesc;                       /* True to sort in descending order */

  160863.   int eEvalmode;                  /* An FTS3_EVAL_XX constant */

  160864.   int nRowAvg;                    /* Average size of database rows, in pages */

  160865.   sqlite3_int64 nDoc;             /* Documents in table */

  160866.   i64 iMinDocid;                  /* Minimum docid to return */

  160867.   i64 iMaxDocid;                  /* Maximum docid to return */

  160868.   int isMatchinfoNeeded;          /* True when aMatchinfo[] needs filling in */

  160869.   MatchinfoBuffer *pMIBuffer;     /* Buffer for matchinfo data */

  160870. };

  160871. 

  160872. #define FTS3_EVAL_FILTER    0

  160873. #define FTS3_EVAL_NEXT      1

  160874. #define FTS3_EVAL_MATCHINFO 2

  160875. 

  160876. /*

  160877. ** The Fts3Cursor.eSearch member is always set to one of the following.

  160878. ** Actualy, Fts3Cursor.eSearch can be greater than or equal to

  160879. ** FTS3_FULLTEXT_SEARCH.  If so, then Fts3Cursor.eSearch - 2 is the index

  160880. ** of the column to be searched.  For example, in

  160881. **

  160882. **     CREATE VIRTUAL TABLE ex1 USING fts3(a,b,c,d);

  160883. **     SELECT docid FROM ex1 WHERE b MATCH 'one two three';

  160884. ** 

  160885. ** Because the LHS of the MATCH operator is 2nd column "b",

  160886. ** Fts3Cursor.eSearch will be set to FTS3_FULLTEXT_SEARCH+1.  (+0 for a,

  160887. ** +1 for b, +2 for c, +3 for d.)  If the LHS of MATCH were "ex1" 

  160888. ** indicating that all columns should be searched,

  160889. ** then eSearch would be set to FTS3_FULLTEXT_SEARCH+4.

  160890. */

  160891. #define FTS3_FULLSCAN_SEARCH 0    /* Linear scan of %_content table */

  160892. #define FTS3_DOCID_SEARCH    1    /* Lookup by rowid on %_content table */

  160893. #define FTS3_FULLTEXT_SEARCH 2    /* Full-text index search */

  160894. 

  160895. /*

  160896. ** The lower 16-bits of the sqlite3_index_info.idxNum value set by

  160897. ** the xBestIndex() method contains the Fts3Cursor.eSearch value described

  160898. ** above. The upper 16-bits contain a combination of the following

  160899. ** bits, used to describe extra constraints on full-text searches.

  160900. */

  160901. #define FTS3_HAVE_LANGID    0x00010000      /* languageid=? */

  160902. #define FTS3_HAVE_DOCID_GE  0x00020000      /* docid>=? */

  160903. #define FTS3_HAVE_DOCID_LE  0x00040000      /* docid<=? */

  160904. 

  160905. struct Fts3Doclist {

  160906.   char *aAll;                    /* Array containing doclist (or NULL) */

  160907.   int nAll;                      /* Size of a[] in bytes */

  160908.   char *pNextDocid;              /* Pointer to next docid */

  160909. 

  160910.   sqlite3_int64 iDocid;          /* Current docid (if pList!=0) */

  160911.   int bFreeList;                 /* True if pList should be sqlite3_free()d */

  160912.   char *pList;                   /* Pointer to position list following iDocid */

  160913.   int nList;                     /* Length of position list */

  160914. };

  160915. 

  160916. /*

  160917. ** A "phrase" is a sequence of one or more tokens that must match in

  160918. ** sequence.  A single token is the base case and the most common case.

  160919. ** For a sequence of tokens contained in double-quotes (i.e. "one two three")

  160920. ** nToken will be the number of tokens in the string.

  160921. */

  160922. struct Fts3PhraseToken {

  160923.   char *z;                        /* Text of the token */

  160924.   int n;                          /* Number of bytes in buffer z */

  160925.   int isPrefix;                   /* True if token ends with a "*" character */

  160926.   int bFirst;                     /* True if token must appear at position 0 */

  160927. 

  160928.   /* Variables above this point are populated when the expression is

  160929.   ** parsed (by code in fts3_expr.c). Below this point the variables are

  160930.   ** used when evaluating the expression. */

  160931.   Fts3DeferredToken *pDeferred;   /* Deferred token object for this token */

  160932.   Fts3MultiSegReader *pSegcsr;    /* Segment-reader for this token */

  160933. };

  160934. 

  160935. struct Fts3Phrase {

  160936.   /* Cache of doclist for this phrase. */

  160937.   Fts3Doclist doclist;

  160938.   int bIncr;                 /* True if doclist is loaded incrementally */

  160939.   int iDoclistToken;

  160940. 

  160941.   /* Used by sqlite3Fts3EvalPhrasePoslist() if this is a descendent of an

  160942.   ** OR condition.  */

  160943.   char *pOrPoslist;

  160944.   i64 iOrDocid;

  160945. 

  160946.   /* Variables below this point are populated by fts3_expr.c when parsing 

  160947.   ** a MATCH expression. Everything above is part of the evaluation phase. 

  160948.   */

  160949.   int nToken;                /* Number of tokens in the phrase */

  160950.   int iColumn;               /* Index of column this phrase must match */

  160951.   Fts3PhraseToken aToken[1]; /* One entry for each token in the phrase */

  160952. };

  160953. 

  160954. /*

  160955. ** A tree of these objects forms the RHS of a MATCH operator.

  160956. **

  160957. ** If Fts3Expr.eType is FTSQUERY_PHRASE and isLoaded is true, then aDoclist 

  160958. ** points to a malloced buffer, size nDoclist bytes, containing the results 

  160959. ** of this phrase query in FTS3 doclist format. As usual, the initial 

  160960. ** "Length" field found in doclists stored on disk is omitted from this 

  160961. ** buffer.

  160962. **

  160963. ** Variable aMI is used only for FTSQUERY_NEAR nodes to store the global

  160964. ** matchinfo data. If it is not NULL, it points to an array of size nCol*3,

  160965. ** where nCol is the number of columns in the queried FTS table. The array

  160966. ** is populated as follows:

  160967. **

  160968. **   aMI[iCol*3 + 0] = Undefined

  160969. **   aMI[iCol*3 + 1] = Number of occurrences

  160970. **   aMI[iCol*3 + 2] = Number of rows containing at least one instance

  160971. **

  160972. ** The aMI array is allocated using sqlite3_malloc(). It should be freed 

  160973. ** when the expression node is.

  160974. */

  160975. struct Fts3Expr {

  160976.   int eType;                 /* One of the FTSQUERY_XXX values defined below */

  160977.   int nNear;                 /* Valid if eType==FTSQUERY_NEAR */

  160978.   Fts3Expr *pParent;         /* pParent->pLeft==this or pParent->pRight==this */

  160979.   Fts3Expr *pLeft;           /* Left operand */

  160980.   Fts3Expr *pRight;          /* Right operand */

  160981.   Fts3Phrase *pPhrase;       /* Valid if eType==FTSQUERY_PHRASE */

  160982. 

  160983.   /* The following are used by the fts3_eval.c module. */

  160984.   sqlite3_int64 iDocid;      /* Current docid */

  160985.   u8 bEof;                   /* True this expression is at EOF already */

  160986.   u8 bStart;                 /* True if iDocid is valid */

  160987.   u8 bDeferred;              /* True if this expression is entirely deferred */

  160988. 

  160989.   /* The following are used by the fts3_snippet.c module. */

  160990.   int iPhrase;               /* Index of this phrase in matchinfo() results */

  160991.   u32 *aMI;                  /* See above */

  160992. };

  160993. 

  160994. /*

  160995. ** Candidate values for Fts3Query.eType. Note that the order of the first

  160996. ** four values is in order of precedence when parsing expressions. For 

  160997. ** example, the following:

  160998. **

  160999. **   "a OR b AND c NOT d NEAR e"

  161000. **

  161001. ** is equivalent to:

  161002. **

  161003. **   "a OR (b AND (c NOT (d NEAR e)))"

  161004. */

  161005. #define FTSQUERY_NEAR   1

  161006. #define FTSQUERY_NOT    2

  161007. #define FTSQUERY_AND    3

  161008. #define FTSQUERY_OR     4

  161009. #define FTSQUERY_PHRASE 5

  161010. 

  161011. 

  161012. /* fts3_write.c */

  161013. SQLITE_PRIVATE int sqlite3Fts3UpdateMethod(sqlite3_vtab*,int,sqlite3_value**,sqlite3_int64*);

  161014. SQLITE_PRIVATE int sqlite3Fts3PendingTermsFlush(Fts3Table *);

  161015. SQLITE_PRIVATE void sqlite3Fts3PendingTermsClear(Fts3Table *);

  161016. SQLITE_PRIVATE int sqlite3Fts3Optimize(Fts3Table *);

  161017. SQLITE_PRIVATE int sqlite3Fts3SegReaderNew(int, int, sqlite3_int64,

  161018.   sqlite3_int64, sqlite3_int64, const char *, int, Fts3SegReader**);

  161019. SQLITE_PRIVATE int sqlite3Fts3SegReaderPending(

  161020.   Fts3Table*,int,const char*,int,int,Fts3SegReader**);

  161021. SQLITE_PRIVATE void sqlite3Fts3SegReaderFree(Fts3SegReader *);

  161022. SQLITE_PRIVATE int sqlite3Fts3AllSegdirs(Fts3Table*, int, int, int, sqlite3_stmt **);

  161023. SQLITE_PRIVATE int sqlite3Fts3ReadBlock(Fts3Table*, sqlite3_int64, char **, int*, int*);

  161024. 

  161025. SQLITE_PRIVATE int sqlite3Fts3SelectDoctotal(Fts3Table *, sqlite3_stmt **);

  161026. SQLITE_PRIVATE int sqlite3Fts3SelectDocsize(Fts3Table *, sqlite3_int64, sqlite3_stmt **);

  161027. 

  161028. #ifndef SQLITE_DISABLE_FTS4_DEFERRED

  161029. SQLITE_PRIVATE void sqlite3Fts3FreeDeferredTokens(Fts3Cursor *);

  161030. SQLITE_PRIVATE int sqlite3Fts3DeferToken(Fts3Cursor *, Fts3PhraseToken *, int);

  161031. SQLITE_PRIVATE int sqlite3Fts3CacheDeferredDoclists(Fts3Cursor *);

  161032. SQLITE_PRIVATE void sqlite3Fts3FreeDeferredDoclists(Fts3Cursor *);

  161033. SQLITE_PRIVATE int sqlite3Fts3DeferredTokenList(Fts3DeferredToken *, char **, int *);

  161034. #else

  161035. # define sqlite3Fts3FreeDeferredTokens(x)

  161036. # define sqlite3Fts3DeferToken(x,y,z) SQLITE_OK

  161037. # define sqlite3Fts3CacheDeferredDoclists(x) SQLITE_OK

  161038. # define sqlite3Fts3FreeDeferredDoclists(x)

  161039. # define sqlite3Fts3DeferredTokenList(x,y,z) SQLITE_OK

  161040. #endif

  161041. 

  161042. SQLITE_PRIVATE void sqlite3Fts3SegmentsClose(Fts3Table *);

  161043. SQLITE_PRIVATE int sqlite3Fts3MaxLevel(Fts3Table *, int *);

  161044. 

  161045. /* Special values interpreted by sqlite3SegReaderCursor() */

  161046. #define FTS3_SEGCURSOR_PENDING        -1

  161047. #define FTS3_SEGCURSOR_ALL            -2

  161048. 

  161049. SQLITE_PRIVATE int sqlite3Fts3SegReaderStart(Fts3Table*, Fts3MultiSegReader*, Fts3SegFilter*);

  161050. SQLITE_PRIVATE int sqlite3Fts3SegReaderStep(Fts3Table *, Fts3MultiSegReader *);

  161051. SQLITE_PRIVATE void sqlite3Fts3SegReaderFinish(Fts3MultiSegReader *);

  161052. 

  161053. SQLITE_PRIVATE int sqlite3Fts3SegReaderCursor(Fts3Table *, 

  161054.     int, int, int, const char *, int, int, int, Fts3MultiSegReader *);

  161055. 

  161056. /* Flags allowed as part of the 4th argument to SegmentReaderIterate() */

  161057. #define FTS3_SEGMENT_REQUIRE_POS   0x00000001

  161058. #define FTS3_SEGMENT_IGNORE_EMPTY  0x00000002

  161059. #define FTS3_SEGMENT_COLUMN_FILTER 0x00000004

  161060. #define FTS3_SEGMENT_PREFIX        0x00000008

  161061. #define FTS3_SEGMENT_SCAN          0x00000010

  161062. #define FTS3_SEGMENT_FIRST         0x00000020

  161063. 

  161064. /* Type passed as 4th argument to SegmentReaderIterate() */

  161065. struct Fts3SegFilter {

  161066.   const char *zTerm;

  161067.   int nTerm;

  161068.   int iCol;

  161069.   int flags;

  161070. };

  161071. 

  161072. struct Fts3MultiSegReader {

  161073.   /* Used internally by sqlite3Fts3SegReaderXXX() calls */

  161074.   Fts3SegReader **apSegment;      /* Array of Fts3SegReader objects */

  161075.   int nSegment;                   /* Size of apSegment array */

  161076.   int nAdvance;                   /* How many seg-readers to advance */

  161077.   Fts3SegFilter *pFilter;         /* Pointer to filter object */

  161078.   char *aBuffer;                  /* Buffer to merge doclists in */

  161079.   int nBuffer;                    /* Allocated size of aBuffer[] in bytes */

  161080. 

  161081.   int iColFilter;                 /* If >=0, filter for this column */

  161082.   int bRestart;

  161083. 

  161084.   /* Used by fts3.c only. */

  161085.   int nCost;                      /* Cost of running iterator */

  161086.   int bLookup;                    /* True if a lookup of a single entry. */

  161087. 

  161088.   /* Output values. Valid only after Fts3SegReaderStep() returns SQLITE_ROW. */

  161089.   char *zTerm;                    /* Pointer to term buffer */

  161090.   int nTerm;                      /* Size of zTerm in bytes */

  161091.   char *aDoclist;                 /* Pointer to doclist buffer */

  161092.   int nDoclist;                   /* Size of aDoclist[] in bytes */

  161093. };

  161094. 

  161095. SQLITE_PRIVATE int sqlite3Fts3Incrmerge(Fts3Table*,int,int);

  161096. 

  161097. #define fts3GetVarint32(p, piVal) (                                           \

  161098.   (*(u8*)(p)&0x80) ? sqlite3Fts3GetVarint32(p, piVal) : (*piVal=*(u8*)(p), 1) \

  161099. )

  161100. 

  161101. /* fts3.c */

  161102. SQLITE_PRIVATE void sqlite3Fts3ErrMsg(char**,const char*,...);

  161103. SQLITE_PRIVATE int sqlite3Fts3PutVarint(char *, sqlite3_int64);

  161104. SQLITE_PRIVATE int sqlite3Fts3GetVarint(const char *, sqlite_int64 *);

  161105. SQLITE_PRIVATE int sqlite3Fts3GetVarint32(const char *, int *);

  161106. SQLITE_PRIVATE int sqlite3Fts3VarintLen(sqlite3_uint64);

  161107. SQLITE_PRIVATE void sqlite3Fts3Dequote(char *);

  161108. SQLITE_PRIVATE void sqlite3Fts3DoclistPrev(int,char*,int,char**,sqlite3_int64*,int*,u8*);

  161109. SQLITE_PRIVATE int sqlite3Fts3EvalPhraseStats(Fts3Cursor *, Fts3Expr *, u32 *);

  161110. SQLITE_PRIVATE int sqlite3Fts3FirstFilter(sqlite3_int64, char *, int, char *);

  161111. SQLITE_PRIVATE void sqlite3Fts3CreateStatTable(int*, Fts3Table*);

  161112. SQLITE_PRIVATE int sqlite3Fts3EvalTestDeferred(Fts3Cursor *pCsr, int *pRc);

  161113. 

  161114. /* fts3_tokenizer.c */

  161115. SQLITE_PRIVATE const char *sqlite3Fts3NextToken(const char *, int *);

  161116. SQLITE_PRIVATE int sqlite3Fts3InitHashTable(sqlite3 *, Fts3Hash *, const char *);

  161117. SQLITE_PRIVATE int sqlite3Fts3InitTokenizer(Fts3Hash *pHash, const char *, 

  161118.     sqlite3_tokenizer **, char **

  161119. );

  161120. SQLITE_PRIVATE int sqlite3Fts3IsIdChar(char);

  161121. 

  161122. /* fts3_snippet.c */

  161123. SQLITE_PRIVATE void sqlite3Fts3Offsets(sqlite3_context*, Fts3Cursor*);

  161124. SQLITE_PRIVATE void sqlite3Fts3Snippet(sqlite3_context *, Fts3Cursor *, const char *,

  161125.   const char *, const char *, int, int

  161126. );

  161127. SQLITE_PRIVATE void sqlite3Fts3Matchinfo(sqlite3_context *, Fts3Cursor *, const char *);

  161128. SQLITE_PRIVATE void sqlite3Fts3MIBufferFree(MatchinfoBuffer *p);

  161129. 

  161130. /* fts3_expr.c */

  161131. SQLITE_PRIVATE int sqlite3Fts3ExprParse(sqlite3_tokenizer *, int,

  161132.   char **, int, int, int, const char *, int, Fts3Expr **, char **

  161133. );

  161134. SQLITE_PRIVATE void sqlite3Fts3ExprFree(Fts3Expr *);

  161135. #ifdef SQLITE_TEST

  161136. SQLITE_PRIVATE int sqlite3Fts3ExprInitTestInterface(sqlite3 *db, Fts3Hash*);

  161137. SQLITE_PRIVATE int sqlite3Fts3InitTerm(sqlite3 *db);

  161138. #endif

  161139. 

  161140. SQLITE_PRIVATE int sqlite3Fts3OpenTokenizer(sqlite3_tokenizer *, int, const char *, int,

  161141.   sqlite3_tokenizer_cursor **

  161142. );

  161143. 

  161144. /* fts3_aux.c */

  161145. SQLITE_PRIVATE int sqlite3Fts3InitAux(sqlite3 *db);

  161146. 

  161147. SQLITE_PRIVATE void sqlite3Fts3EvalPhraseCleanup(Fts3Phrase *);

  161148. 

  161149. SQLITE_PRIVATE int sqlite3Fts3MsrIncrStart(

  161150.     Fts3Table*, Fts3MultiSegReader*, int, const char*, int);

  161151. SQLITE_PRIVATE int sqlite3Fts3MsrIncrNext(

  161152.     Fts3Table *, Fts3MultiSegReader *, sqlite3_int64 *, char **, int *);

  161153. SQLITE_PRIVATE int sqlite3Fts3EvalPhrasePoslist(Fts3Cursor *, Fts3Expr *, int iCol, char **); 

  161154. SQLITE_PRIVATE int sqlite3Fts3MsrOvfl(Fts3Cursor *, Fts3MultiSegReader *, int *);

  161155. SQLITE_PRIVATE int sqlite3Fts3MsrIncrRestart(Fts3MultiSegReader *pCsr);

  161156. 

  161157. /* fts3_tokenize_vtab.c */

  161158. SQLITE_PRIVATE int sqlite3Fts3InitTok(sqlite3*, Fts3Hash *);

  161159. 

  161160. /* fts3_unicode2.c (functions generated by parsing unicode text files) */

  161161. #ifndef SQLITE_DISABLE_FTS3_UNICODE

  161162. SQLITE_PRIVATE int sqlite3FtsUnicodeFold(int, int);

  161163. SQLITE_PRIVATE int sqlite3FtsUnicodeIsalnum(int);

  161164. SQLITE_PRIVATE int sqlite3FtsUnicodeIsdiacritic(int);

  161165. #endif

  161166. 

  161167. #endif /* !SQLITE_CORE || SQLITE_ENABLE_FTS3 */

  161168. #endif /* _FTSINT_H */

  161169. 

  161170. /************** End of fts3Int.h *********************************************/

  161171. /************** Continuing where we left off in fts3.c ***********************/

  161172. #if !defined(SQLITE_CORE) || defined(SQLITE_ENABLE_FTS3)

  161173. 

  161174. #if defined(SQLITE_ENABLE_FTS3) && !defined(SQLITE_CORE)

  161175. # define SQLITE_CORE 1

  161176. #endif

  161177. 

  161178. /* #include <assert.h> */

  161179. /* #include <stdlib.h> */

  161180. /* #include <stddef.h> */

  161181. /* #include <stdio.h> */

  161182. /* #include <string.h> */

  161183. /* #include <stdarg.h> */

  161184. 

  161185. /* #include "fts3.h" */

  161186. #ifndef SQLITE_CORE 

  161187. /* # include "sqlite3ext.h" */

  161188.   SQLITE_EXTENSION_INIT1

  161189. #endif

  161190. 

  161191. static int fts3EvalNext(Fts3Cursor *pCsr);

  161192. static int fts3EvalStart(Fts3Cursor *pCsr);

  161193. static int fts3TermSegReaderCursor(

  161194.     Fts3Cursor *, const char *, int, int, Fts3MultiSegReader **);

  161195. 

  161196. #ifndef SQLITE_AMALGAMATION

  161197. # if defined(SQLITE_DEBUG)

  161198. SQLITE_PRIVATE int sqlite3Fts3Always(int b) { assert( b ); return b; }

  161199. SQLITE_PRIVATE int sqlite3Fts3Never(int b)  { assert( !b ); return b; }

  161200. # endif

  161201. #endif

  161202. 

  161203. /*

  161204. ** This variable is set to false when running tests for which the on disk

  161205. ** structures should not be corrupt. Otherwise, true. If it is false, extra

  161206. ** assert() conditions in the fts3 code are activated - conditions that are

  161207. ** only true if it is guaranteed that the fts3 database is not corrupt.

  161208. */

  161209. SQLITE_API int sqlite3_fts3_may_be_corrupt = 1;

  161210. 

  161211. /* 

  161212. ** Write a 64-bit variable-length integer to memory starting at p[0].

  161213. ** The length of data written will be between 1 and FTS3_VARINT_MAX bytes.

  161214. ** The number of bytes written is returned.

  161215. */

  161216. SQLITE_PRIVATE int sqlite3Fts3PutVarint(char *p, sqlite_int64 v){

  161217.   unsigned char *q = (unsigned char *) p;

  161218.   sqlite_uint64 vu = v;

  161219.   do{

  161220.     *q++ = (unsigned char) ((vu & 0x7f) | 0x80);

  161221.     vu >>= 7;

  161222.   }while( vu!=0 );

  161223.   q[-1] &= 0x7f;  /* turn off high bit in final byte */

  161224.   assert( q - (unsigned char *)p <= FTS3_VARINT_MAX );

  161225.   return (int) (q - (unsigned char *)p);

  161226. }

  161227. 

  161228. #define GETVARINT_STEP(v, ptr, shift, mask1, mask2, var, ret) \

  161229.   v = (v & mask1) | ( (*(const unsigned char*)(ptr++)) << shift );  \

  161230.   if( (v & mask2)==0 ){ var = v; return ret; }

  161231. #define GETVARINT_INIT(v, ptr, shift, mask1, mask2, var, ret) \

  161232.   v = (*ptr++);                                               \

  161233.   if( (v & mask2)==0 ){ var = v; return ret; }

  161234. 

  161235. /* 

  161236. ** Read a 64-bit variable-length integer from memory starting at p[0].

  161237. ** Return the number of bytes read, or 0 on error.

  161238. ** The value is stored in *v.

  161239. */

  161240. SQLITE_PRIVATE int sqlite3Fts3GetVarint(const char *pBuf, sqlite_int64 *v){

  161241.   const unsigned char *p = (const unsigned char*)pBuf;

  161242.   const unsigned char *pStart = p;

  161243.   u32 a;

  161244.   u64 b;

  161245.   int shift;

  161246. 

  161247.   GETVARINT_INIT(a, p, 0,  0x00,     0x80, *v, 1);

  161248.   GETVARINT_STEP(a, p, 7,  0x7F,     0x4000, *v, 2);

  161249.   GETVARINT_STEP(a, p, 14, 0x3FFF,   0x200000, *v, 3);

  161250.   GETVARINT_STEP(a, p, 21, 0x1FFFFF, 0x10000000, *v, 4);

  161251.   b = (a & 0x0FFFFFFF );

  161252. 

  161253.   for(shift=28; shift<=63; shift+=7){

  161254.     u64 c = *p++;

  161255.     b += (c&0x7F) << shift;

  161256.     if( (c & 0x80)==0 ) break;

  161257.   }

  161258.   *v = b;

  161259.   return (int)(p - pStart);

  161260. }

  161261. 

  161262. /*

  161263. ** Similar to sqlite3Fts3GetVarint(), except that the output is truncated to 

  161264. ** a non-negative 32-bit integer before it is returned.

  161265. */

  161266. SQLITE_PRIVATE int sqlite3Fts3GetVarint32(const char *p, int *pi){

  161267.   const unsigned char *ptr = (const unsigned char*)p;

  161268.   u32 a;

  161269. 

  161270. #ifndef fts3GetVarint32

  161271.   GETVARINT_INIT(a, ptr, 0,  0x00,     0x80, *pi, 1);

  161272. #else

  161273.   a = (*ptr++);

  161274.   assert( a & 0x80 );

  161275. #endif

  161276. 

  161277.   GETVARINT_STEP(a, ptr, 7,  0x7F,     0x4000, *pi, 2);

  161278.   GETVARINT_STEP(a, ptr, 14, 0x3FFF,   0x200000, *pi, 3);

  161279.   GETVARINT_STEP(a, ptr, 21, 0x1FFFFF, 0x10000000, *pi, 4);

  161280.   a = (a & 0x0FFFFFFF );

  161281.   *pi = (int)(a | ((u32)(*ptr & 0x07) << 28));

  161282.   assert( 0==(a & 0x80000000) );

  161283.   assert( *pi>=0 );

  161284.   return 5;

  161285. }

  161286. 

  161287. /*

  161288. ** Return the number of bytes required to encode v as a varint

  161289. */

  161290. SQLITE_PRIVATE int sqlite3Fts3VarintLen(sqlite3_uint64 v){

  161291.   int i = 0;

  161292.   do{

  161293.     i++;

  161294.     v >>= 7;

  161295.   }while( v!=0 );

  161296.   return i;

  161297. }

  161298. 

  161299. /*

  161300. ** Convert an SQL-style quoted string into a normal string by removing

  161301. ** the quote characters.  The conversion is done in-place.  If the

  161302. ** input does not begin with a quote character, then this routine

  161303. ** is a no-op.

  161304. **

  161305. ** Examples:

  161306. **

  161307. **     "abc"   becomes   abc

  161308. **     'xyz'   becomes   xyz

  161309. **     [pqr]   becomes   pqr

  161310. **     `mno`   becomes   mno

  161311. **

  161312. */

  161313. SQLITE_PRIVATE void sqlite3Fts3Dequote(char *z){

  161314.   char quote;                     /* Quote character (if any ) */

  161315. 

  161316.   quote = z[0];

  161317.   if( quote=='[' || quote=='\'' || quote=='"' || quote=='`' ){

  161318.     int iIn = 1;                  /* Index of next byte to read from input */

  161319.     int iOut = 0;                 /* Index of next byte to write to output */

  161320. 

  161321.     /* If the first byte was a '[', then the close-quote character is a ']' */

  161322.     if( quote=='[' ) quote = ']';  

  161323. 

  161324.     while( z[iIn] ){

  161325.       if( z[iIn]==quote ){

  161326.         if( z[iIn+1]!=quote ) break;

  161327.         z[iOut++] = quote;

  161328.         iIn += 2;

  161329.       }else{

  161330.         z[iOut++] = z[iIn++];

  161331.       }

  161332.     }

  161333.     z[iOut] = '\0';

  161334.   }

  161335. }

  161336. 

  161337. /*

  161338. ** Read a single varint from the doclist at *pp and advance *pp to point

  161339. ** to the first byte past the end of the varint.  Add the value of the varint

  161340. ** to *pVal.

  161341. */

  161342. static void fts3GetDeltaVarint(char **pp, sqlite3_int64 *pVal){

  161343.   sqlite3_int64 iVal;

  161344.   *pp += sqlite3Fts3GetVarint(*pp, &iVal);

  161345.   *pVal += iVal;

  161346. }

  161347. 

  161348. /*

  161349. ** When this function is called, *pp points to the first byte following a

  161350. ** varint that is part of a doclist (or position-list, or any other list

  161351. ** of varints). This function moves *pp to point to the start of that varint,

  161352. ** and sets *pVal by the varint value.

  161353. **

  161354. ** Argument pStart points to the first byte of the doclist that the

  161355. ** varint is part of.

  161356. */

  161357. static void fts3GetReverseVarint(

  161358.   char **pp, 

  161359.   char *pStart, 

  161360.   sqlite3_int64 *pVal

  161361. ){

  161362.   sqlite3_int64 iVal;

  161363.   char *p;

  161364. 

  161365.   /* Pointer p now points at the first byte past the varint we are 

  161366.   ** interested in. So, unless the doclist is corrupt, the 0x80 bit is

  161367.   ** clear on character p[-1]. */

  161368.   for(p = (*pp)-2; p>=pStart && *p&0x80; p--);

  161369.   p++;

  161370.   *pp = p;

  161371. 

  161372.   sqlite3Fts3GetVarint(p, &iVal);

  161373.   *pVal = iVal;

  161374. }

  161375. 

  161376. /*

  161377. ** The xDisconnect() virtual table method.

  161378. */

  161379. static int fts3DisconnectMethod(sqlite3_vtab *pVtab){

  161380.   Fts3Table *p = (Fts3Table *)pVtab;

  161381.   int i;

  161382. 

  161383.   assert( p->nPendingData==0 );

  161384.   assert( p->pSegments==0 );

  161385. 

  161386.   /* Free any prepared statements held */

  161387.   sqlite3_finalize(p->pSeekStmt);

  161388.   for(i=0; i<SizeofArray(p->aStmt); i++){

  161389.     sqlite3_finalize(p->aStmt[i]);

  161390.   }

  161391.   sqlite3_free(p->zSegmentsTbl);

  161392.   sqlite3_free(p->zReadExprlist);

  161393.   sqlite3_free(p->zWriteExprlist);

  161394.   sqlite3_free(p->zContentTbl);

  161395.   sqlite3_free(p->zLanguageid);

  161396. 

  161397.   /* Invoke the tokenizer destructor to free the tokenizer. */

  161398.   p->pTokenizer->pModule->xDestroy(p->pTokenizer);

  161399. 

  161400.   sqlite3_free(p);

  161401.   return SQLITE_OK;

  161402. }

  161403. 

  161404. /*

  161405. ** Write an error message into *pzErr

  161406. */

  161407. SQLITE_PRIVATE void sqlite3Fts3ErrMsg(char **pzErr, const char *zFormat, ...){

  161408.   va_list ap;

  161409.   sqlite3_free(*pzErr);

  161410.   va_start(ap, zFormat);

  161411.   *pzErr = sqlite3_vmprintf(zFormat, ap);

  161412.   va_end(ap);

  161413. }

  161414. 

  161415. /*

  161416. ** Construct one or more SQL statements from the format string given

  161417. ** and then evaluate those statements. The success code is written

  161418. ** into *pRc.

  161419. **

  161420. ** If *pRc is initially non-zero then this routine is a no-op.

  161421. */

  161422. static void fts3DbExec(

  161423.   int *pRc,              /* Success code */

  161424.   sqlite3 *db,           /* Database in which to run SQL */

  161425.   const char *zFormat,   /* Format string for SQL */

  161426.   ...                    /* Arguments to the format string */

  161427. ){

  161428.   va_list ap;

  161429.   char *zSql;

  161430.   if( *pRc ) return;

  161431.   va_start(ap, zFormat);

  161432.   zSql = sqlite3_vmprintf(zFormat, ap);

  161433.   va_end(ap);

  161434.   if( zSql==0 ){

  161435.     *pRc = SQLITE_NOMEM;

  161436.   }else{

  161437.     *pRc = sqlite3_exec(db, zSql, 0, 0, 0);

  161438.     sqlite3_free(zSql);

  161439.   }

  161440. }

  161441. 

  161442. /*

  161443. ** The xDestroy() virtual table method.

  161444. */

  161445. static int fts3DestroyMethod(sqlite3_vtab *pVtab){

  161446.   Fts3Table *p = (Fts3Table *)pVtab;

  161447.   int rc = SQLITE_OK;              /* Return code */

  161448.   const char *zDb = p->zDb;        /* Name of database (e.g. "main", "temp") */

  161449.   sqlite3 *db = p->db;             /* Database handle */

  161450. 

  161451.   /* Drop the shadow tables */

  161452.   fts3DbExec(&rc, db, 

  161453.     "DROP TABLE IF EXISTS %Q.'%q_segments';"

  161454.     "DROP TABLE IF EXISTS %Q.'%q_segdir';"

  161455.     "DROP TABLE IF EXISTS %Q.'%q_docsize';"

  161456.     "DROP TABLE IF EXISTS %Q.'%q_stat';"

  161457.     "%s DROP TABLE IF EXISTS %Q.'%q_content';",

  161458.     zDb, p->zName,

  161459.     zDb, p->zName,

  161460.     zDb, p->zName,

  161461.     zDb, p->zName,

  161462.     (p->zContentTbl ? "--" : ""), zDb,p->zName

  161463.   );

  161464. 

  161465.   /* If everything has worked, invoke fts3DisconnectMethod() to free the

  161466.   ** memory associated with the Fts3Table structure and return SQLITE_OK.

  161467.   ** Otherwise, return an SQLite error code.

  161468.   */

  161469.   return (rc==SQLITE_OK ? fts3DisconnectMethod(pVtab) : rc);

  161470. }

  161471. 

  161472. 

  161473. /*

  161474. ** Invoke sqlite3_declare_vtab() to declare the schema for the FTS3 table

  161475. ** passed as the first argument. This is done as part of the xConnect()

  161476. ** and xCreate() methods.

  161477. **

  161478. ** If *pRc is non-zero when this function is called, it is a no-op. 

  161479. ** Otherwise, if an error occurs, an SQLite error code is stored in *pRc

  161480. ** before returning.

  161481. */

  161482. static void fts3DeclareVtab(int *pRc, Fts3Table *p){

  161483.   if( *pRc==SQLITE_OK ){

  161484.     int i;                        /* Iterator variable */

  161485.     int rc;                       /* Return code */

  161486.     char *zSql;                   /* SQL statement passed to declare_vtab() */

  161487.     char *zCols;                  /* List of user defined columns */

  161488.     const char *zLanguageid;

  161489. 

  161490.     zLanguageid = (p->zLanguageid ? p->zLanguageid : "__langid");

  161491.     sqlite3_vtab_config(p->db, SQLITE_VTAB_CONSTRAINT_SUPPORT, 1);

  161492. 

  161493.     /* Create a list of user columns for the virtual table */

  161494.     zCols = sqlite3_mprintf("%Q, ", p->azColumn[0]);

  161495.     for(i=1; zCols && i<p->nColumn; i++){

  161496.       zCols = sqlite3_mprintf("%z%Q, ", zCols, p->azColumn[i]);

  161497.     }

  161498. 

  161499.     /* Create the whole "CREATE TABLE" statement to pass to SQLite */

  161500.     zSql = sqlite3_mprintf(

  161501.         "CREATE TABLE x(%s %Q HIDDEN, docid HIDDEN, %Q HIDDEN)", 

  161502.         zCols, p->zName, zLanguageid

  161503.     );

  161504.     if( !zCols || !zSql ){

  161505.       rc = SQLITE_NOMEM;

  161506.     }else{

  161507.       rc = sqlite3_declare_vtab(p->db, zSql);

  161508.     }

  161509. 

  161510.     sqlite3_free(zSql);

  161511.     sqlite3_free(zCols);

  161512.     *pRc = rc;

  161513.   }

  161514. }

  161515. 

  161516. /*

  161517. ** Create the %_stat table if it does not already exist.

  161518. */

  161519. SQLITE_PRIVATE void sqlite3Fts3CreateStatTable(int *pRc, Fts3Table *p){

  161520.   fts3DbExec(pRc, p->db, 

  161521.       "CREATE TABLE IF NOT EXISTS %Q.'%q_stat'"

  161522.           "(id INTEGER PRIMARY KEY, value BLOB);",

  161523.       p->zDb, p->zName

  161524.   );

  161525.   if( (*pRc)==SQLITE_OK ) p->bHasStat = 1;

  161526. }

  161527. 

  161528. /*

  161529. ** Create the backing store tables (%_content, %_segments and %_segdir)

  161530. ** required by the FTS3 table passed as the only argument. This is done

  161531. ** as part of the vtab xCreate() method.

  161532. **

  161533. ** If the p->bHasDocsize boolean is true (indicating that this is an

  161534. ** FTS4 table, not an FTS3 table) then also create the %_docsize and

  161535. ** %_stat tables required by FTS4.

  161536. */

  161537. static int fts3CreateTables(Fts3Table *p){

  161538.   int rc = SQLITE_OK;             /* Return code */

  161539.   int i;                          /* Iterator variable */

  161540.   sqlite3 *db = p->db;            /* The database connection */

  161541. 

  161542.   if( p->zContentTbl==0 ){

  161543.     const char *zLanguageid = p->zLanguageid;

  161544.     char *zContentCols;           /* Columns of %_content table */

  161545. 

  161546.     /* Create a list of user columns for the content table */

  161547.     zContentCols = sqlite3_mprintf("docid INTEGER PRIMARY KEY");

  161548.     for(i=0; zContentCols && i<p->nColumn; i++){

  161549.       char *z = p->azColumn[i];

  161550.       zContentCols = sqlite3_mprintf("%z, 'c%d%q'", zContentCols, i, z);

  161551.     }

  161552.     if( zLanguageid && zContentCols ){

  161553.       zContentCols = sqlite3_mprintf("%z, langid", zContentCols, zLanguageid);

  161554.     }

  161555.     if( zContentCols==0 ) rc = SQLITE_NOMEM;

  161556.   

  161557.     /* Create the content table */

  161558.     fts3DbExec(&rc, db, 

  161559.        "CREATE TABLE %Q.'%q_content'(%s)",

  161560.        p->zDb, p->zName, zContentCols

  161561.     );

  161562.     sqlite3_free(zContentCols);

  161563.   }

  161564. 

  161565.   /* Create other tables */

  161566.   fts3DbExec(&rc, db, 

  161567.       "CREATE TABLE %Q.'%q_segments'(blockid INTEGER PRIMARY KEY, block BLOB);",

  161568.       p->zDb, p->zName

  161569.   );

  161570.   fts3DbExec(&rc, db, 

  161571.       "CREATE TABLE %Q.'%q_segdir'("

  161572.         "level INTEGER,"

  161573.         "idx INTEGER,"

  161574.         "start_block INTEGER,"

  161575.         "leaves_end_block INTEGER,"

  161576.         "end_block INTEGER,"

  161577.         "root BLOB,"

  161578.         "PRIMARY KEY(level, idx)"

  161579.       ");",

  161580.       p->zDb, p->zName

  161581.   );

  161582.   if( p->bHasDocsize ){

  161583.     fts3DbExec(&rc, db, 

  161584.         "CREATE TABLE %Q.'%q_docsize'(docid INTEGER PRIMARY KEY, size BLOB);",

  161585.         p->zDb, p->zName

  161586.     );

  161587.   }

  161588.   assert( p->bHasStat==p->bFts4 );

  161589.   if( p->bHasStat ){

  161590.     sqlite3Fts3CreateStatTable(&rc, p);

  161591.   }

  161592.   return rc;

  161593. }

  161594. 

  161595. /*

  161596. ** Store the current database page-size in bytes in p->nPgsz.

  161597. **

  161598. ** If *pRc is non-zero when this function is called, it is a no-op. 

  161599. ** Otherwise, if an error occurs, an SQLite error code is stored in *pRc

  161600. ** before returning.

  161601. */

  161602. static void fts3DatabasePageSize(int *pRc, Fts3Table *p){

  161603.   if( *pRc==SQLITE_OK ){

  161604.     int rc;                       /* Return code */

  161605.     char *zSql;                   /* SQL text "PRAGMA %Q.page_size" */

  161606.     sqlite3_stmt *pStmt;          /* Compiled "PRAGMA %Q.page_size" statement */

  161607.   

  161608.     zSql = sqlite3_mprintf("PRAGMA %Q.page_size", p->zDb);

  161609.     if( !zSql ){

  161610.       rc = SQLITE_NOMEM;

  161611.     }else{

  161612.       rc = sqlite3_prepare(p->db, zSql, -1, &pStmt, 0);

  161613.       if( rc==SQLITE_OK ){

  161614.         sqlite3_step(pStmt);

  161615.         p->nPgsz = sqlite3_column_int(pStmt, 0);

  161616.         rc = sqlite3_finalize(pStmt);

  161617.       }else if( rc==SQLITE_AUTH ){

  161618.         p->nPgsz = 1024;

  161619.         rc = SQLITE_OK;

  161620.       }

  161621.     }

  161622.     assert( p->nPgsz>0 || rc!=SQLITE_OK );

  161623.     sqlite3_free(zSql);

  161624.     *pRc = rc;

  161625.   }

  161626. }

  161627. 

  161628. /*

  161629. ** "Special" FTS4 arguments are column specifications of the following form:

  161630. **

  161631. **   <key> = <value>

  161632. **

  161633. ** There may not be whitespace surrounding the "=" character. The <value> 

  161634. ** term may be quoted, but the <key> may not.

  161635. */

  161636. static int fts3IsSpecialColumn(

  161637.   const char *z, 

  161638.   int *pnKey,

  161639.   char **pzValue

  161640. ){

  161641.   char *zValue;

  161642.   const char *zCsr = z;

  161643. 

  161644.   while( *zCsr!='=' ){

  161645.     if( *zCsr=='\0' ) return 0;

  161646.     zCsr++;

  161647.   }

  161648. 

  161649.   *pnKey = (int)(zCsr-z);

  161650.   zValue = sqlite3_mprintf("%s", &zCsr[1]);

  161651.   if( zValue ){

  161652.     sqlite3Fts3Dequote(zValue);

  161653.   }

  161654.   *pzValue = zValue;

  161655.   return 1;

  161656. }

  161657. 

  161658. /*

  161659. ** Append the output of a printf() style formatting to an existing string.

  161660. */

  161661. static void fts3Appendf(

  161662.   int *pRc,                       /* IN/OUT: Error code */

  161663.   char **pz,                      /* IN/OUT: Pointer to string buffer */

  161664.   const char *zFormat,            /* Printf format string to append */

  161665.   ...                             /* Arguments for printf format string */

  161666. ){

  161667.   if( *pRc==SQLITE_OK ){

  161668.     va_list ap;

  161669.     char *z;

  161670.     va_start(ap, zFormat);

  161671.     z = sqlite3_vmprintf(zFormat, ap);

  161672.     va_end(ap);

  161673.     if( z && *pz ){

  161674.       char *z2 = sqlite3_mprintf("%s%s", *pz, z);

  161675.       sqlite3_free(z);

  161676.       z = z2;

  161677.     }

  161678.     if( z==0 ) *pRc = SQLITE_NOMEM;

  161679.     sqlite3_free(*pz);

  161680.     *pz = z;

  161681.   }

  161682. }

  161683. 

  161684. /*

  161685. ** Return a copy of input string zInput enclosed in double-quotes (") and

  161686. ** with all double quote characters escaped. For example:

  161687. **

  161688. **     fts3QuoteId("un \"zip\"")   ->    "un \"\"zip\"\""

  161689. **

  161690. ** The pointer returned points to memory obtained from sqlite3_malloc(). It

  161691. ** is the callers responsibility to call sqlite3_free() to release this

  161692. ** memory.

  161693. */

  161694. static char *fts3QuoteId(char const *zInput){

  161695.   sqlite3_int64 nRet;

  161696.   char *zRet;

  161697.   nRet = 2 + (int)strlen(zInput)*2 + 1;

  161698.   zRet = sqlite3_malloc64(nRet);

  161699.   if( zRet ){

  161700.     int i;

  161701.     char *z = zRet;

  161702.     *(z++) = '"';

  161703.     for(i=0; zInput[i]; i++){

  161704.       if( zInput[i]=='"' ) *(z++) = '"';

  161705.       *(z++) = zInput[i];

  161706.     }

  161707.     *(z++) = '"';

  161708.     *(z++) = '\0';

  161709.   }

  161710.   return zRet;

  161711. }

  161712. 

  161713. /*

  161714. ** Return a list of comma separated SQL expressions and a FROM clause that 

  161715. ** could be used in a SELECT statement such as the following:

  161716. **

  161717. **     SELECT <list of expressions> FROM %_content AS x ...

  161718. **

  161719. ** to return the docid, followed by each column of text data in order

  161720. ** from left to write. If parameter zFunc is not NULL, then instead of

  161721. ** being returned directly each column of text data is passed to an SQL

  161722. ** function named zFunc first. For example, if zFunc is "unzip" and the

  161723. ** table has the three user-defined columns "a", "b", and "c", the following

  161724. ** string is returned:

  161725. **

  161726. **     "docid, unzip(x.'a'), unzip(x.'b'), unzip(x.'c') FROM %_content AS x"

  161727. **

  161728. ** The pointer returned points to a buffer allocated by sqlite3_malloc(). It

  161729. ** is the responsibility of the caller to eventually free it.

  161730. **

  161731. ** If *pRc is not SQLITE_OK when this function is called, it is a no-op (and

  161732. ** a NULL pointer is returned). Otherwise, if an OOM error is encountered

  161733. ** by this function, NULL is returned and *pRc is set to SQLITE_NOMEM. If

  161734. ** no error occurs, *pRc is left unmodified.

  161735. */

  161736. static char *fts3ReadExprList(Fts3Table *p, const char *zFunc, int *pRc){

  161737.   char *zRet = 0;

  161738.   char *zFree = 0;

  161739.   char *zFunction;

  161740.   int i;

  161741. 

  161742.   if( p->zContentTbl==0 ){

  161743.     if( !zFunc ){

  161744.       zFunction = "";

  161745.     }else{

  161746.       zFree = zFunction = fts3QuoteId(zFunc);

  161747.     }

  161748.     fts3Appendf(pRc, &zRet, "docid");

  161749.     for(i=0; i<p->nColumn; i++){

  161750.       fts3Appendf(pRc, &zRet, ",%s(x.'c%d%q')", zFunction, i, p->azColumn[i]);

  161751.     }

  161752.     if( p->zLanguageid ){

  161753.       fts3Appendf(pRc, &zRet, ", x.%Q", "langid");

  161754.     }

  161755.     sqlite3_free(zFree);

  161756.   }else{

  161757.     fts3Appendf(pRc, &zRet, "rowid");

  161758.     for(i=0; i<p->nColumn; i++){

  161759.       fts3Appendf(pRc, &zRet, ", x.'%q'", p->azColumn[i]);

  161760.     }

  161761.     if( p->zLanguageid ){

  161762.       fts3Appendf(pRc, &zRet, ", x.%Q", p->zLanguageid);

  161763.     }

  161764.   }

  161765.   fts3Appendf(pRc, &zRet, " FROM '%q'.'%q%s' AS x", 

  161766.       p->zDb,

  161767.       (p->zContentTbl ? p->zContentTbl : p->zName),

  161768.       (p->zContentTbl ? "" : "_content")

  161769.   );

  161770.   return zRet;

  161771. }

  161772. 

  161773. /*

  161774. ** Return a list of N comma separated question marks, where N is the number

  161775. ** of columns in the %_content table (one for the docid plus one for each

  161776. ** user-defined text column).

  161777. **

  161778. ** If argument zFunc is not NULL, then all but the first question mark

  161779. ** is preceded by zFunc and an open bracket, and followed by a closed

  161780. ** bracket. For example, if zFunc is "zip" and the FTS3 table has three 

  161781. ** user-defined text columns, the following string is returned:

  161782. **

  161783. **     "?, zip(?), zip(?), zip(?)"

  161784. **

  161785. ** The pointer returned points to a buffer allocated by sqlite3_malloc(). It

  161786. ** is the responsibility of the caller to eventually free it.

  161787. **

  161788. ** If *pRc is not SQLITE_OK when this function is called, it is a no-op (and

  161789. ** a NULL pointer is returned). Otherwise, if an OOM error is encountered

  161790. ** by this function, NULL is returned and *pRc is set to SQLITE_NOMEM. If

  161791. ** no error occurs, *pRc is left unmodified.

  161792. */

  161793. static char *fts3WriteExprList(Fts3Table *p, const char *zFunc, int *pRc){

  161794.   char *zRet = 0;

  161795.   char *zFree = 0;

  161796.   char *zFunction;

  161797.   int i;

  161798. 

  161799.   if( !zFunc ){

  161800.     zFunction = "";

  161801.   }else{

  161802.     zFree = zFunction = fts3QuoteId(zFunc);

  161803.   }

  161804.   fts3Appendf(pRc, &zRet, "?");

  161805.   for(i=0; i<p->nColumn; i++){

  161806.     fts3Appendf(pRc, &zRet, ",%s(?)", zFunction);

  161807.   }

  161808.   if( p->zLanguageid ){

  161809.     fts3Appendf(pRc, &zRet, ", ?");

  161810.   }

  161811.   sqlite3_free(zFree);

  161812.   return zRet;

  161813. }

  161814. 

  161815. /*

  161816. ** This function interprets the string at (*pp) as a non-negative integer

  161817. ** value. It reads the integer and sets *pnOut to the value read, then 

  161818. ** sets *pp to point to the byte immediately following the last byte of

  161819. ** the integer value.

  161820. **

  161821. ** Only decimal digits ('0'..'9') may be part of an integer value. 

  161822. **

  161823. ** If *pp does not being with a decimal digit SQLITE_ERROR is returned and

  161824. ** the output value undefined. Otherwise SQLITE_OK is returned.

  161825. **

  161826. ** This function is used when parsing the "prefix=" FTS4 parameter.

  161827. */

  161828. static int fts3GobbleInt(const char **pp, int *pnOut){

  161829.   const int MAX_NPREFIX = 10000000;

  161830.   const char *p;                  /* Iterator pointer */

  161831.   int nInt = 0;                   /* Output value */

  161832. 

  161833.   for(p=*pp; p[0]>='0' && p[0]<='9'; p++){

  161834.     nInt = nInt * 10 + (p[0] - '0');

  161835.     if( nInt>MAX_NPREFIX ){

  161836.       nInt = 0;

  161837.       break;

  161838.     }

  161839.   }

  161840.   if( p==*pp ) return SQLITE_ERROR;

  161841.   *pnOut = nInt;

  161842.   *pp = p;

  161843.   return SQLITE_OK;

  161844. }

  161845. 

  161846. /*

  161847. ** This function is called to allocate an array of Fts3Index structures

  161848. ** representing the indexes maintained by the current FTS table. FTS tables

  161849. ** always maintain the main "terms" index, but may also maintain one or

  161850. ** more "prefix" indexes, depending on the value of the "prefix=" parameter

  161851. ** (if any) specified as part of the CREATE VIRTUAL TABLE statement.

  161852. **

  161853. ** Argument zParam is passed the value of the "prefix=" option if one was

  161854. ** specified, or NULL otherwise.

  161855. **

  161856. ** If no error occurs, SQLITE_OK is returned and *apIndex set to point to

  161857. ** the allocated array. *pnIndex is set to the number of elements in the

  161858. ** array. If an error does occur, an SQLite error code is returned.

  161859. **

  161860. ** Regardless of whether or not an error is returned, it is the responsibility

  161861. ** of the caller to call sqlite3_free() on the output array to free it.

  161862. */

  161863. static int fts3PrefixParameter(

  161864.   const char *zParam,             /* ABC in prefix=ABC parameter to parse */

  161865.   int *pnIndex,                   /* OUT: size of *apIndex[] array */

  161866.   struct Fts3Index **apIndex      /* OUT: Array of indexes for this table */

  161867. ){

  161868.   struct Fts3Index *aIndex;       /* Allocated array */

  161869.   int nIndex = 1;                 /* Number of entries in array */

  161870. 

  161871.   if( zParam && zParam[0] ){

  161872.     const char *p;

  161873.     nIndex++;

  161874.     for(p=zParam; *p; p++){

  161875.       if( *p==',' ) nIndex++;

  161876.     }

  161877.   }

  161878. 

  161879.   aIndex = sqlite3_malloc64(sizeof(struct Fts3Index) * nIndex);

  161880.   *apIndex = aIndex;

  161881.   if( !aIndex ){

  161882.     return SQLITE_NOMEM;

  161883.   }

  161884. 

  161885.   memset(aIndex, 0, sizeof(struct Fts3Index) * nIndex);

  161886.   if( zParam ){

  161887.     const char *p = zParam;

  161888.     int i;

  161889.     for(i=1; i<nIndex; i++){

  161890.       int nPrefix = 0;

  161891.       if( fts3GobbleInt(&p, &nPrefix) ) return SQLITE_ERROR;

  161892.       assert( nPrefix>=0 );

  161893.       if( nPrefix==0 ){

  161894.         nIndex--;

  161895.         i--;

  161896.       }else{

  161897.         aIndex[i].nPrefix = nPrefix;

  161898.       }

  161899.       p++;

  161900.     }

  161901.   }

  161902. 

  161903.   *pnIndex = nIndex;

  161904.   return SQLITE_OK;

  161905. }

  161906. 

  161907. /*

  161908. ** This function is called when initializing an FTS4 table that uses the

  161909. ** content=xxx option. It determines the number of and names of the columns

  161910. ** of the new FTS4 table.

  161911. **

  161912. ** The third argument passed to this function is the value passed to the

  161913. ** config=xxx option (i.e. "xxx"). This function queries the database for

  161914. ** a table of that name. If found, the output variables are populated

  161915. ** as follows:

  161916. **

  161917. **   *pnCol:   Set to the number of columns table xxx has,

  161918. **

  161919. **   *pnStr:   Set to the total amount of space required to store a copy

  161920. **             of each columns name, including the nul-terminator.

  161921. **

  161922. **   *pazCol:  Set to point to an array of *pnCol strings. Each string is

  161923. **             the name of the corresponding column in table xxx. The array

  161924. **             and its contents are allocated using a single allocation. It

  161925. **             is the responsibility of the caller to free this allocation

  161926. **             by eventually passing the *pazCol value to sqlite3_free().

  161927. **

  161928. ** If the table cannot be found, an error code is returned and the output

  161929. ** variables are undefined. Or, if an OOM is encountered, SQLITE_NOMEM is

  161930. ** returned (and the output variables are undefined).

  161931. */

  161932. static int fts3ContentColumns(

  161933.   sqlite3 *db,                    /* Database handle */

  161934.   const char *zDb,                /* Name of db (i.e. "main", "temp" etc.) */

  161935.   const char *zTbl,               /* Name of content table */

  161936.   const char ***pazCol,           /* OUT: Malloc'd array of column names */

  161937.   int *pnCol,                     /* OUT: Size of array *pazCol */

  161938.   int *pnStr,                     /* OUT: Bytes of string content */

  161939.   char **pzErr                    /* OUT: error message */

  161940. ){

  161941.   int rc = SQLITE_OK;             /* Return code */

  161942.   char *zSql;                     /* "SELECT *" statement on zTbl */  

  161943.   sqlite3_stmt *pStmt = 0;        /* Compiled version of zSql */

  161944. 

  161945.   zSql = sqlite3_mprintf("SELECT * FROM %Q.%Q", zDb, zTbl);

  161946.   if( !zSql ){

  161947.     rc = SQLITE_NOMEM;

  161948.   }else{

  161949.     rc = sqlite3_prepare(db, zSql, -1, &pStmt, 0);

  161950.     if( rc!=SQLITE_OK ){

  161951.       sqlite3Fts3ErrMsg(pzErr, "%s", sqlite3_errmsg(db));

  161952.     }

  161953.   }

  161954.   sqlite3_free(zSql);

  161955. 

  161956.   if( rc==SQLITE_OK ){

  161957.     const char **azCol;           /* Output array */

  161958.     sqlite3_int64 nStr = 0;       /* Size of all column names (incl. 0x00) */

  161959.     int nCol;                     /* Number of table columns */

  161960.     int i;                        /* Used to iterate through columns */

  161961. 

  161962.     /* Loop through the returned columns. Set nStr to the number of bytes of

  161963.     ** space required to store a copy of each column name, including the

  161964.     ** nul-terminator byte.  */

  161965.     nCol = sqlite3_column_count(pStmt);

  161966.     for(i=0; i<nCol; i++){

  161967.       const char *zCol = sqlite3_column_name(pStmt, i);

  161968.       nStr += strlen(zCol) + 1;

  161969.     }

  161970. 

  161971.     /* Allocate and populate the array to return. */

  161972.     azCol = (const char **)sqlite3_malloc64(sizeof(char *) * nCol + nStr);

  161973.     if( azCol==0 ){

  161974.       rc = SQLITE_NOMEM;

  161975.     }else{

  161976.       char *p = (char *)&azCol[nCol];

  161977.       for(i=0; i<nCol; i++){

  161978.         const char *zCol = sqlite3_column_name(pStmt, i);

  161979.         int n = (int)strlen(zCol)+1;

  161980.         memcpy(p, zCol, n);

  161981.         azCol[i] = p;

  161982.         p += n;

  161983.       }

  161984.     }

  161985.     sqlite3_finalize(pStmt);

  161986. 

  161987.     /* Set the output variables. */

  161988.     *pnCol = nCol;

  161989.     *pnStr = nStr;

  161990.     *pazCol = azCol;

  161991.   }

  161992. 

  161993.   return rc;

  161994. }

  161995. 

  161996. /*

  161997. ** This function is the implementation of both the xConnect and xCreate

  161998. ** methods of the FTS3 virtual table.

  161999. **

  162000. ** The argv[] array contains the following:

  162001. **

  162002. **   argv[0]   -> module name  ("fts3" or "fts4")

  162003. **   argv[1]   -> database name

  162004. **   argv[2]   -> table name

  162005. **   argv[...] -> "column name" and other module argument fields.

  162006. */

  162007. static int fts3InitVtab(

  162008.   int isCreate,                   /* True for xCreate, false for xConnect */

  162009.   sqlite3 *db,                    /* The SQLite database connection */

  162010.   void *pAux,                     /* Hash table containing tokenizers */

  162011.   int argc,                       /* Number of elements in argv array */

  162012.   const char * const *argv,       /* xCreate/xConnect argument array */

  162013.   sqlite3_vtab **ppVTab,          /* Write the resulting vtab structure here */

  162014.   char **pzErr                    /* Write any error message here */

  162015. ){

  162016.   Fts3Hash *pHash = (Fts3Hash *)pAux;

  162017.   Fts3Table *p = 0;               /* Pointer to allocated vtab */

  162018.   int rc = SQLITE_OK;             /* Return code */

  162019.   int i;                          /* Iterator variable */

  162020.   sqlite3_int64 nByte;            /* Size of allocation used for *p */

  162021.   int iCol;                       /* Column index */

  162022.   int nString = 0;                /* Bytes required to hold all column names */

  162023.   int nCol = 0;                   /* Number of columns in the FTS table */

  162024.   char *zCsr;                     /* Space for holding column names */

  162025.   int nDb;                        /* Bytes required to hold database name */

  162026.   int nName;                      /* Bytes required to hold table name */

  162027.   int isFts4 = (argv[0][3]=='4'); /* True for FTS4, false for FTS3 */

  162028.   const char **aCol;              /* Array of column names */

  162029.   sqlite3_tokenizer *pTokenizer = 0;        /* Tokenizer for this table */

  162030. 

  162031.   int nIndex = 0;                 /* Size of aIndex[] array */

  162032.   struct Fts3Index *aIndex = 0;   /* Array of indexes for this table */

  162033. 

  162034.   /* The results of parsing supported FTS4 key=value options: */

  162035.   int bNoDocsize = 0;             /* True to omit %_docsize table */

  162036.   int bDescIdx = 0;               /* True to store descending indexes */

  162037.   char *zPrefix = 0;              /* Prefix parameter value (or NULL) */

  162038.   char *zCompress = 0;            /* compress=? parameter (or NULL) */

  162039.   char *zUncompress = 0;          /* uncompress=? parameter (or NULL) */

  162040.   char *zContent = 0;             /* content=? parameter (or NULL) */

  162041.   char *zLanguageid = 0;          /* languageid=? parameter (or NULL) */

  162042.   char **azNotindexed = 0;        /* The set of notindexed= columns */

  162043.   int nNotindexed = 0;            /* Size of azNotindexed[] array */

  162044. 

  162045.   assert( strlen(argv[0])==4 );

  162046.   assert( (sqlite3_strnicmp(argv[0], "fts4", 4)==0 && isFts4)

  162047.        || (sqlite3_strnicmp(argv[0], "fts3", 4)==0 && !isFts4)

  162048.   );

  162049. 

  162050.   nDb = (int)strlen(argv[1]) + 1;

  162051.   nName = (int)strlen(argv[2]) + 1;

  162052. 

  162053.   nByte = sizeof(const char *) * (argc-2);

  162054.   aCol = (const char **)sqlite3_malloc64(nByte);

  162055.   if( aCol ){

  162056.     memset((void*)aCol, 0, nByte);

  162057.     azNotindexed = (char **)sqlite3_malloc64(nByte);

  162058.   }

  162059.   if( azNotindexed ){

  162060.     memset(azNotindexed, 0, nByte);

  162061.   }

  162062.   if( !aCol || !azNotindexed ){

  162063.     rc = SQLITE_NOMEM;

  162064.     goto fts3_init_out;

  162065.   }

  162066. 

  162067.   /* Loop through all of the arguments passed by the user to the FTS3/4

  162068.   ** module (i.e. all the column names and special arguments). This loop

  162069.   ** does the following:

  162070.   **

  162071.   **   + Figures out the number of columns the FTSX table will have, and

  162072.   **     the number of bytes of space that must be allocated to store copies

  162073.   **     of the column names.

  162074.   **

  162075.   **   + If there is a tokenizer specification included in the arguments,

  162076.   **     initializes the tokenizer pTokenizer.

  162077.   */

  162078.   for(i=3; rc==SQLITE_OK && i<argc; i++){

  162079.     char const *z = argv[i];

  162080.     int nKey;

  162081.     char *zVal;

  162082. 

  162083.     /* Check if this is a tokenizer specification */

  162084.     if( !pTokenizer 

  162085.      && strlen(z)>8

  162086.      && 0==sqlite3_strnicmp(z, "tokenize", 8) 

  162087.      && 0==sqlite3Fts3IsIdChar(z[8])

  162088.     ){

  162089.       rc = sqlite3Fts3InitTokenizer(pHash, &z[9], &pTokenizer, pzErr);

  162090.     }

  162091. 

  162092.     /* Check if it is an FTS4 special argument. */

  162093.     else if( isFts4 && fts3IsSpecialColumn(z, &nKey, &zVal) ){

  162094.       struct Fts4Option {

  162095.         const char *zOpt;

  162096.         int nOpt;

  162097.       } aFts4Opt[] = {

  162098.         { "matchinfo",   9 },     /* 0 -> MATCHINFO */

  162099.         { "prefix",      6 },     /* 1 -> PREFIX */

  162100.         { "compress",    8 },     /* 2 -> COMPRESS */

  162101.         { "uncompress", 10 },     /* 3 -> UNCOMPRESS */

  162102.         { "order",       5 },     /* 4 -> ORDER */

  162103.         { "content",     7 },     /* 5 -> CONTENT */

  162104.         { "languageid", 10 },     /* 6 -> LANGUAGEID */

  162105.         { "notindexed", 10 }      /* 7 -> NOTINDEXED */

  162106.       };

  162107. 

  162108.       int iOpt;

  162109.       if( !zVal ){

  162110.         rc = SQLITE_NOMEM;

  162111.       }else{

  162112.         for(iOpt=0; iOpt<SizeofArray(aFts4Opt); iOpt++){

  162113.           struct Fts4Option *pOp = &aFts4Opt[iOpt];

  162114.           if( nKey==pOp->nOpt && !sqlite3_strnicmp(z, pOp->zOpt, pOp->nOpt) ){

  162115.             break;

  162116.           }

  162117.         }

  162118.         switch( iOpt ){

  162119.           case 0:               /* MATCHINFO */

  162120.             if( strlen(zVal)!=4 || sqlite3_strnicmp(zVal, "fts3", 4) ){

  162121.               sqlite3Fts3ErrMsg(pzErr, "unrecognized matchinfo: %s", zVal);

  162122.               rc = SQLITE_ERROR;

  162123.             }

  162124.             bNoDocsize = 1;

  162125.             break;

  162126. 

  162127.           case 1:               /* PREFIX */

  162128.             sqlite3_free(zPrefix);

  162129.             zPrefix = zVal;

  162130.             zVal = 0;

  162131.             break;

  162132. 

  162133.           case 2:               /* COMPRESS */

  162134.             sqlite3_free(zCompress);

  162135.             zCompress = zVal;

  162136.             zVal = 0;

  162137.             break;

  162138. 

  162139.           case 3:               /* UNCOMPRESS */

  162140.             sqlite3_free(zUncompress);

  162141.             zUncompress = zVal;

  162142.             zVal = 0;

  162143.             break;

  162144. 

  162145.           case 4:               /* ORDER */

  162146.             if( (strlen(zVal)!=3 || sqlite3_strnicmp(zVal, "asc", 3)) 

  162147.              && (strlen(zVal)!=4 || sqlite3_strnicmp(zVal, "desc", 4)) 

  162148.             ){

  162149.               sqlite3Fts3ErrMsg(pzErr, "unrecognized order: %s", zVal);

  162150.               rc = SQLITE_ERROR;

  162151.             }

  162152.             bDescIdx = (zVal[0]=='d' || zVal[0]=='D');

  162153.             break;

  162154. 

  162155.           case 5:              /* CONTENT */

  162156.             sqlite3_free(zContent);

  162157.             zContent = zVal;

  162158.             zVal = 0;

  162159.             break;

  162160. 

  162161.           case 6:              /* LANGUAGEID */

  162162.             assert( iOpt==6 );

  162163.             sqlite3_free(zLanguageid);

  162164.             zLanguageid = zVal;

  162165.             zVal = 0;

  162166.             break;

  162167. 

  162168.           case 7:              /* NOTINDEXED */

  162169.             azNotindexed[nNotindexed++] = zVal;

  162170.             zVal = 0;

  162171.             break;

  162172. 

  162173.           default:

  162174.             assert( iOpt==SizeofArray(aFts4Opt) );

  162175.             sqlite3Fts3ErrMsg(pzErr, "unrecognized parameter: %s", z);

  162176.             rc = SQLITE_ERROR;

  162177.             break;

  162178.         }

  162179.         sqlite3_free(zVal);

  162180.       }

  162181.     }

  162182. 

  162183.     /* Otherwise, the argument is a column name. */

  162184.     else {

  162185.       nString += (int)(strlen(z) + 1);

  162186.       aCol[nCol++] = z;

  162187.     }

  162188.   }

  162189. 

  162190.   /* If a content=xxx option was specified, the following:

  162191.   **

  162192.   **   1. Ignore any compress= and uncompress= options.

  162193.   **

  162194.   **   2. If no column names were specified as part of the CREATE VIRTUAL

  162195.   **      TABLE statement, use all columns from the content table.

  162196.   */

  162197.   if( rc==SQLITE_OK && zContent ){

  162198.     sqlite3_free(zCompress); 

  162199.     sqlite3_free(zUncompress); 

  162200.     zCompress = 0;

  162201.     zUncompress = 0;

  162202.     if( nCol==0 ){

  162203.       sqlite3_free((void*)aCol); 

  162204.       aCol = 0;

  162205.       rc = fts3ContentColumns(db, argv[1], zContent,&aCol,&nCol,&nString,pzErr);

  162206. 

  162207.       /* If a languageid= option was specified, remove the language id

  162208.       ** column from the aCol[] array. */ 

  162209.       if( rc==SQLITE_OK && zLanguageid ){

  162210.         int j;

  162211.         for(j=0; j<nCol; j++){

  162212.           if( sqlite3_stricmp(zLanguageid, aCol[j])==0 ){

  162213.             int k;

  162214.             for(k=j; k<nCol; k++) aCol[k] = aCol[k+1];

  162215.             nCol--;

  162216.             break;

  162217.           }

  162218.         }

  162219.       }

  162220.     }

  162221.   }

  162222.   if( rc!=SQLITE_OK ) goto fts3_init_out;

  162223. 

  162224.   if( nCol==0 ){

  162225.     assert( nString==0 );

  162226.     aCol[0] = "content";

  162227.     nString = 8;

  162228.     nCol = 1;

  162229.   }

  162230. 

  162231.   if( pTokenizer==0 ){

  162232.     rc = sqlite3Fts3InitTokenizer(pHash, "simple", &pTokenizer, pzErr);

  162233.     if( rc!=SQLITE_OK ) goto fts3_init_out;

  162234.   }

  162235.   assert( pTokenizer );

  162236. 

  162237.   rc = fts3PrefixParameter(zPrefix, &nIndex, &aIndex);

  162238.   if( rc==SQLITE_ERROR ){

  162239.     assert( zPrefix );

  162240.     sqlite3Fts3ErrMsg(pzErr, "error parsing prefix parameter: %s", zPrefix);

  162241.   }

  162242.   if( rc!=SQLITE_OK ) goto fts3_init_out;

  162243. 

  162244.   /* Allocate and populate the Fts3Table structure. */

  162245.   nByte = sizeof(Fts3Table) +                  /* Fts3Table */

  162246.           nCol * sizeof(char *) +              /* azColumn */

  162247.           nIndex * sizeof(struct Fts3Index) +  /* aIndex */

  162248.           nCol * sizeof(u8) +                  /* abNotindexed */

  162249.           nName +                              /* zName */

  162250.           nDb +                                /* zDb */

  162251.           nString;                             /* Space for azColumn strings */

  162252.   p = (Fts3Table*)sqlite3_malloc64(nByte);

  162253.   if( p==0 ){

  162254.     rc = SQLITE_NOMEM;

  162255.     goto fts3_init_out;

  162256.   }

  162257.   memset(p, 0, nByte);

  162258.   p->db = db;

  162259.   p->nColumn = nCol;

  162260.   p->nPendingData = 0;

  162261.   p->azColumn = (char **)&p[1];

  162262.   p->pTokenizer = pTokenizer;

  162263.   p->nMaxPendingData = FTS3_MAX_PENDING_DATA;

  162264.   p->bHasDocsize = (isFts4 && bNoDocsize==0);

  162265.   p->bHasStat = (u8)isFts4;

  162266.   p->bFts4 = (u8)isFts4;

  162267.   p->bDescIdx = (u8)bDescIdx;

  162268.   p->nAutoincrmerge = 0xff;   /* 0xff means setting unknown */

  162269.   p->zContentTbl = zContent;

  162270.   p->zLanguageid = zLanguageid;

  162271.   zContent = 0;

  162272.   zLanguageid = 0;

  162273.   TESTONLY( p->inTransaction = -1 );

  162274.   TESTONLY( p->mxSavepoint = -1 );

  162275. 

  162276.   p->aIndex = (struct Fts3Index *)&p->azColumn[nCol];

  162277.   memcpy(p->aIndex, aIndex, sizeof(struct Fts3Index) * nIndex);

  162278.   p->nIndex = nIndex;

  162279.   for(i=0; i<nIndex; i++){

  162280.     fts3HashInit(&p->aIndex[i].hPending, FTS3_HASH_STRING, 1);

  162281.   }

  162282.   p->abNotindexed = (u8 *)&p->aIndex[nIndex];

  162283. 

  162284.   /* Fill in the zName and zDb fields of the vtab structure. */

  162285.   zCsr = (char *)&p->abNotindexed[nCol];

  162286.   p->zName = zCsr;

  162287.   memcpy(zCsr, argv[2], nName);

  162288.   zCsr += nName;

  162289.   p->zDb = zCsr;

  162290.   memcpy(zCsr, argv[1], nDb);

  162291.   zCsr += nDb;

  162292. 

  162293.   /* Fill in the azColumn array */

  162294.   for(iCol=0; iCol<nCol; iCol++){

  162295.     char *z; 

  162296.     int n = 0;

  162297.     z = (char *)sqlite3Fts3NextToken(aCol[iCol], &n);

  162298.     if( n>0 ){

  162299.       memcpy(zCsr, z, n);

  162300.     }

  162301.     zCsr[n] = '\0';

  162302.     sqlite3Fts3Dequote(zCsr);

  162303.     p->azColumn[iCol] = zCsr;

  162304.     zCsr += n+1;

  162305.     assert( zCsr <= &((char *)p)[nByte] );

  162306.   }

  162307. 

  162308.   /* Fill in the abNotindexed array */

  162309.   for(iCol=0; iCol<nCol; iCol++){

  162310.     int n = (int)strlen(p->azColumn[iCol]);

  162311.     for(i=0; i<nNotindexed; i++){

  162312.       char *zNot = azNotindexed[i];

  162313.       if( zNot && n==(int)strlen(zNot)

  162314.        && 0==sqlite3_strnicmp(p->azColumn[iCol], zNot, n) 

  162315.       ){

  162316.         p->abNotindexed[iCol] = 1;

  162317.         sqlite3_free(zNot);

  162318.         azNotindexed[i] = 0;

  162319.       }

  162320.     }

  162321.   }

  162322.   for(i=0; i<nNotindexed; i++){

  162323.     if( azNotindexed[i] ){

  162324.       sqlite3Fts3ErrMsg(pzErr, "no such column: %s", azNotindexed[i]);

  162325.       rc = SQLITE_ERROR;

  162326.     }

  162327.   }

  162328. 

  162329.   if( rc==SQLITE_OK && (zCompress==0)!=(zUncompress==0) ){

  162330.     char const *zMiss = (zCompress==0 ? "compress" : "uncompress");

  162331.     rc = SQLITE_ERROR;

  162332.     sqlite3Fts3ErrMsg(pzErr, "missing %s parameter in fts4 constructor", zMiss);

  162333.   }

  162334.   p->zReadExprlist = fts3ReadExprList(p, zUncompress, &rc);

  162335.   p->zWriteExprlist = fts3WriteExprList(p, zCompress, &rc);

  162336.   if( rc!=SQLITE_OK ) goto fts3_init_out;

  162337. 

  162338.   /* If this is an xCreate call, create the underlying tables in the 

  162339.   ** database. TODO: For xConnect(), it could verify that said tables exist.

  162340.   */

  162341.   if( isCreate ){

  162342.     rc = fts3CreateTables(p);

  162343.   }

  162344. 

  162345.   /* Check to see if a legacy fts3 table has been "upgraded" by the

  162346.   ** addition of a %_stat table so that it can use incremental merge.

  162347.   */

  162348.   if( !isFts4 && !isCreate ){

  162349.     p->bHasStat = 2;

  162350.   }

  162351. 

  162352.   /* Figure out the page-size for the database. This is required in order to

  162353.   ** estimate the cost of loading large doclists from the database.  */

  162354.   fts3DatabasePageSize(&rc, p);

  162355.   p->nNodeSize = p->nPgsz-35;

  162356. 

  162357.   /* Declare the table schema to SQLite. */

  162358.   fts3DeclareVtab(&rc, p);

  162359. 

  162360. fts3_init_out:

  162361.   sqlite3_free(zPrefix);

  162362.   sqlite3_free(aIndex);

  162363.   sqlite3_free(zCompress);

  162364.   sqlite3_free(zUncompress);

  162365.   sqlite3_free(zContent);

  162366.   sqlite3_free(zLanguageid);

  162367.   for(i=0; i<nNotindexed; i++) sqlite3_free(azNotindexed[i]);

  162368.   sqlite3_free((void *)aCol);

  162369.   sqlite3_free((void *)azNotindexed);

  162370.   if( rc!=SQLITE_OK ){

  162371.     if( p ){

  162372.       fts3DisconnectMethod((sqlite3_vtab *)p);

  162373.     }else if( pTokenizer ){

  162374.       pTokenizer->pModule->xDestroy(pTokenizer);

  162375.     }

  162376.   }else{

  162377.     assert( p->pSegments==0 );

  162378.     *ppVTab = &p->base;

  162379.   }

  162380.   return rc;

  162381. }

  162382. 

  162383. /*

  162384. ** The xConnect() and xCreate() methods for the virtual table. All the

  162385. ** work is done in function fts3InitVtab().

  162386. */

  162387. static int fts3ConnectMethod(

  162388.   sqlite3 *db,                    /* Database connection */

  162389.   void *pAux,                     /* Pointer to tokenizer hash table */

  162390.   int argc,                       /* Number of elements in argv array */

  162391.   const char * const *argv,       /* xCreate/xConnect argument array */

  162392.   sqlite3_vtab **ppVtab,          /* OUT: New sqlite3_vtab object */

  162393.   char **pzErr                    /* OUT: sqlite3_malloc'd error message */

  162394. ){

  162395.   return fts3InitVtab(0, db, pAux, argc, argv, ppVtab, pzErr);

  162396. }

  162397. static int fts3CreateMethod(

  162398.   sqlite3 *db,                    /* Database connection */

  162399.   void *pAux,                     /* Pointer to tokenizer hash table */

  162400.   int argc,                       /* Number of elements in argv array */

  162401.   const char * const *argv,       /* xCreate/xConnect argument array */

  162402.   sqlite3_vtab **ppVtab,          /* OUT: New sqlite3_vtab object */

  162403.   char **pzErr                    /* OUT: sqlite3_malloc'd error message */

  162404. ){

  162405.   return fts3InitVtab(1, db, pAux, argc, argv, ppVtab, pzErr);

  162406. }

  162407. 

  162408. /*

  162409. ** Set the pIdxInfo->estimatedRows variable to nRow. Unless this

  162410. ** extension is currently being used by a version of SQLite too old to

  162411. ** support estimatedRows. In that case this function is a no-op.

  162412. */

  162413. static void fts3SetEstimatedRows(sqlite3_index_info *pIdxInfo, i64 nRow){

  162414. #if SQLITE_VERSION_NUMBER>=3008002

  162415.   if( sqlite3_libversion_number()>=3008002 ){

  162416.     pIdxInfo->estimatedRows = nRow;

  162417.   }

  162418. #endif

  162419. }

  162420. 

  162421. /*

  162422. ** Set the SQLITE_INDEX_SCAN_UNIQUE flag in pIdxInfo->flags. Unless this

  162423. ** extension is currently being used by a version of SQLite too old to

  162424. ** support index-info flags. In that case this function is a no-op.

  162425. */

  162426. static void fts3SetUniqueFlag(sqlite3_index_info *pIdxInfo){

  162427. #if SQLITE_VERSION_NUMBER>=3008012

  162428.   if( sqlite3_libversion_number()>=3008012 ){

  162429.     pIdxInfo->idxFlags |= SQLITE_INDEX_SCAN_UNIQUE;

  162430.   }

  162431. #endif

  162432. }

  162433. 

  162434. /* 

  162435. ** Implementation of the xBestIndex method for FTS3 tables. There

  162436. ** are three possible strategies, in order of preference:

  162437. **

  162438. **   1. Direct lookup by rowid or docid. 

  162439. **   2. Full-text search using a MATCH operator on a non-docid column.

  162440. **   3. Linear scan of %_content table.

  162441. */

  162442. static int fts3BestIndexMethod(sqlite3_vtab *pVTab, sqlite3_index_info *pInfo){

  162443.   Fts3Table *p = (Fts3Table *)pVTab;

  162444.   int i;                          /* Iterator variable */

  162445.   int iCons = -1;                 /* Index of constraint to use */

  162446. 

  162447.   int iLangidCons = -1;           /* Index of langid=x constraint, if present */

  162448.   int iDocidGe = -1;              /* Index of docid>=x constraint, if present */

  162449.   int iDocidLe = -1;              /* Index of docid<=x constraint, if present */

  162450.   int iIdx;

  162451. 

  162452.   /* By default use a full table scan. This is an expensive option,

  162453.   ** so search through the constraints to see if a more efficient 

  162454.   ** strategy is possible.

  162455.   */

  162456.   pInfo->idxNum = FTS3_FULLSCAN_SEARCH;

  162457.   pInfo->estimatedCost = 5000000;

  162458.   for(i=0; i<pInfo->nConstraint; i++){

  162459.     int bDocid;                 /* True if this constraint is on docid */

  162460.     struct sqlite3_index_constraint *pCons = &pInfo->aConstraint[i];

  162461.     if( pCons->usable==0 ){

  162462.       if( pCons->op==SQLITE_INDEX_CONSTRAINT_MATCH ){

  162463.         /* There exists an unusable MATCH constraint. This means that if

  162464.         ** the planner does elect to use the results of this call as part

  162465.         ** of the overall query plan the user will see an "unable to use

  162466.         ** function MATCH in the requested context" error. To discourage

  162467.         ** this, return a very high cost here.  */

  162468.         pInfo->idxNum = FTS3_FULLSCAN_SEARCH;

  162469.         pInfo->estimatedCost = 1e50;

  162470.         fts3SetEstimatedRows(pInfo, ((sqlite3_int64)1) << 50);

  162471.         return SQLITE_OK;

  162472.       }

  162473.       continue;

  162474.     }

  162475. 

  162476.     bDocid = (pCons->iColumn<0 || pCons->iColumn==p->nColumn+1);

  162477. 

  162478.     /* A direct lookup on the rowid or docid column. Assign a cost of 1.0. */

  162479.     if( iCons<0 && pCons->op==SQLITE_INDEX_CONSTRAINT_EQ && bDocid ){

  162480.       pInfo->idxNum = FTS3_DOCID_SEARCH;

  162481.       pInfo->estimatedCost = 1.0;

  162482.       iCons = i;

  162483.     }

  162484. 

  162485.     /* A MATCH constraint. Use a full-text search.

  162486.     **

  162487.     ** If there is more than one MATCH constraint available, use the first

  162488.     ** one encountered. If there is both a MATCH constraint and a direct

  162489.     ** rowid/docid lookup, prefer the MATCH strategy. This is done even 

  162490.     ** though the rowid/docid lookup is faster than a MATCH query, selecting

  162491.     ** it would lead to an "unable to use function MATCH in the requested 

  162492.     ** context" error.

  162493.     */

  162494.     if( pCons->op==SQLITE_INDEX_CONSTRAINT_MATCH 

  162495.      && pCons->iColumn>=0 && pCons->iColumn<=p->nColumn

  162496.     ){

  162497.       pInfo->idxNum = FTS3_FULLTEXT_SEARCH + pCons->iColumn;

  162498.       pInfo->estimatedCost = 2.0;

  162499.       iCons = i;

  162500.     }

  162501. 

  162502.     /* Equality constraint on the langid column */

  162503.     if( pCons->op==SQLITE_INDEX_CONSTRAINT_EQ 

  162504.      && pCons->iColumn==p->nColumn + 2

  162505.     ){

  162506.       iLangidCons = i;

  162507.     }

  162508. 

  162509.     if( bDocid ){

  162510.       switch( pCons->op ){

  162511.         case SQLITE_INDEX_CONSTRAINT_GE:

  162512.         case SQLITE_INDEX_CONSTRAINT_GT:

  162513.           iDocidGe = i;

  162514.           break;

  162515. 

  162516.         case SQLITE_INDEX_CONSTRAINT_LE:

  162517.         case SQLITE_INDEX_CONSTRAINT_LT:

  162518.           iDocidLe = i;

  162519.           break;

  162520.       }

  162521.     }

  162522.   }

  162523. 

  162524.   /* If using a docid=? or rowid=? strategy, set the UNIQUE flag. */

  162525.   if( pInfo->idxNum==FTS3_DOCID_SEARCH ) fts3SetUniqueFlag(pInfo);

  162526. 

  162527.   iIdx = 1;

  162528.   if( iCons>=0 ){

  162529.     pInfo->aConstraintUsage[iCons].argvIndex = iIdx++;

  162530.     pInfo->aConstraintUsage[iCons].omit = 1;

  162531.   } 

  162532.   if( iLangidCons>=0 ){

  162533.     pInfo->idxNum |= FTS3_HAVE_LANGID;

  162534.     pInfo->aConstraintUsage[iLangidCons].argvIndex = iIdx++;

  162535.   } 

  162536.   if( iDocidGe>=0 ){

  162537.     pInfo->idxNum |= FTS3_HAVE_DOCID_GE;

  162538.     pInfo->aConstraintUsage[iDocidGe].argvIndex = iIdx++;

  162539.   } 

  162540.   if( iDocidLe>=0 ){

  162541.     pInfo->idxNum |= FTS3_HAVE_DOCID_LE;

  162542.     pInfo->aConstraintUsage[iDocidLe].argvIndex = iIdx++;

  162543.   } 

  162544. 

  162545.   /* Regardless of the strategy selected, FTS can deliver rows in rowid (or

  162546.   ** docid) order. Both ascending and descending are possible. 

  162547.   */

  162548.   if( pInfo->nOrderBy==1 ){

  162549.     struct sqlite3_index_orderby *pOrder = &pInfo->aOrderBy[0];

  162550.     if( pOrder->iColumn<0 || pOrder->iColumn==p->nColumn+1 ){

  162551.       if( pOrder->desc ){

  162552.         pInfo->idxStr = "DESC";

  162553.       }else{

  162554.         pInfo->idxStr = "ASC";

  162555.       }

  162556.       pInfo->orderByConsumed = 1;

  162557.     }

  162558.   }

  162559. 

  162560.   assert( p->pSegments==0 );

  162561.   return SQLITE_OK;

  162562. }

  162563. 

  162564. /*

  162565. ** Implementation of xOpen method.

  162566. */

  162567. static int fts3OpenMethod(sqlite3_vtab *pVTab, sqlite3_vtab_cursor **ppCsr){

  162568.   sqlite3_vtab_cursor *pCsr;               /* Allocated cursor */

  162569. 

  162570.   UNUSED_PARAMETER(pVTab);

  162571. 

  162572.   /* Allocate a buffer large enough for an Fts3Cursor structure. If the

  162573.   ** allocation succeeds, zero it and return SQLITE_OK. Otherwise, 

  162574.   ** if the allocation fails, return SQLITE_NOMEM.

  162575.   */

  162576.   *ppCsr = pCsr = (sqlite3_vtab_cursor *)sqlite3_malloc(sizeof(Fts3Cursor));

  162577.   if( !pCsr ){

  162578.     return SQLITE_NOMEM;

  162579.   }

  162580.   memset(pCsr, 0, sizeof(Fts3Cursor));

  162581.   return SQLITE_OK;

  162582. }

  162583. 

  162584. /*

  162585. ** Finalize the statement handle at pCsr->pStmt.

  162586. **

  162587. ** Or, if that statement handle is one created by fts3CursorSeekStmt(),

  162588. ** and the Fts3Table.pSeekStmt slot is currently NULL, save the statement

  162589. ** pointer there instead of finalizing it.

  162590. */

  162591. static void fts3CursorFinalizeStmt(Fts3Cursor *pCsr){

  162592.   if( pCsr->bSeekStmt ){

  162593.     Fts3Table *p = (Fts3Table *)pCsr->base.pVtab;

  162594.     if( p->pSeekStmt==0 ){

  162595.       p->pSeekStmt = pCsr->pStmt;

  162596.       sqlite3_reset(pCsr->pStmt);

  162597.       pCsr->pStmt = 0;

  162598.     }

  162599.     pCsr->bSeekStmt = 0;

  162600.   }

  162601.   sqlite3_finalize(pCsr->pStmt);

  162602. }

  162603. 

  162604. /*

  162605. ** Free all resources currently held by the cursor passed as the only

  162606. ** argument.

  162607. */

  162608. static void fts3ClearCursor(Fts3Cursor *pCsr){

  162609.   fts3CursorFinalizeStmt(pCsr);

  162610.   sqlite3Fts3FreeDeferredTokens(pCsr);

  162611.   sqlite3_free(pCsr->aDoclist);

  162612.   sqlite3Fts3MIBufferFree(pCsr->pMIBuffer);

  162613.   sqlite3Fts3ExprFree(pCsr->pExpr);

  162614.   memset(&(&pCsr->base)[1], 0, sizeof(Fts3Cursor)-sizeof(sqlite3_vtab_cursor));

  162615. }

  162616. 

  162617. /*

  162618. ** Close the cursor.  For additional information see the documentation

  162619. ** on the xClose method of the virtual table interface.

  162620. */

  162621. static int fts3CloseMethod(sqlite3_vtab_cursor *pCursor){

  162622.   Fts3Cursor *pCsr = (Fts3Cursor *)pCursor;

  162623.   assert( ((Fts3Table *)pCsr->base.pVtab)->pSegments==0 );

  162624.   fts3ClearCursor(pCsr);

  162625.   assert( ((Fts3Table *)pCsr->base.pVtab)->pSegments==0 );

  162626.   sqlite3_free(pCsr);

  162627.   return SQLITE_OK;

  162628. }

  162629. 

  162630. /*

  162631. ** If pCsr->pStmt has not been prepared (i.e. if pCsr->pStmt==0), then

  162632. ** compose and prepare an SQL statement of the form:

  162633. **

  162634. **    "SELECT <columns> FROM %_content WHERE rowid = ?"

  162635. **

  162636. ** (or the equivalent for a content=xxx table) and set pCsr->pStmt to

  162637. ** it. If an error occurs, return an SQLite error code.

  162638. */

  162639. static int fts3CursorSeekStmt(Fts3Cursor *pCsr){

  162640.   int rc = SQLITE_OK;

  162641.   if( pCsr->pStmt==0 ){

  162642.     Fts3Table *p = (Fts3Table *)pCsr->base.pVtab;

  162643.     char *zSql;

  162644.     if( p->pSeekStmt ){

  162645.       pCsr->pStmt = p->pSeekStmt;

  162646.       p->pSeekStmt = 0;

  162647.     }else{

  162648.       zSql = sqlite3_mprintf("SELECT %s WHERE rowid = ?", p->zReadExprlist);

  162649.       if( !zSql ) return SQLITE_NOMEM;

  162650.       rc = sqlite3_prepare_v3(p->db, zSql,-1,SQLITE_PREPARE_PERSISTENT,&pCsr->pStmt,0);

  162651.       sqlite3_free(zSql);

  162652.     }

  162653.     if( rc==SQLITE_OK ) pCsr->bSeekStmt = 1;

  162654.   }

  162655.   return rc;

  162656. }

  162657. 

  162658. /*

  162659. ** Position the pCsr->pStmt statement so that it is on the row

  162660. ** of the %_content table that contains the last match.  Return

  162661. ** SQLITE_OK on success.  

  162662. */

  162663. static int fts3CursorSeek(sqlite3_context *pContext, Fts3Cursor *pCsr){

  162664.   int rc = SQLITE_OK;

  162665.   if( pCsr->isRequireSeek ){

  162666.     rc = fts3CursorSeekStmt(pCsr);

  162667.     if( rc==SQLITE_OK ){

  162668.       sqlite3_bind_int64(pCsr->pStmt, 1, pCsr->iPrevId);

  162669.       pCsr->isRequireSeek = 0;

  162670.       if( SQLITE_ROW==sqlite3_step(pCsr->pStmt) ){

  162671.         return SQLITE_OK;

  162672.       }else{

  162673.         rc = sqlite3_reset(pCsr->pStmt);

  162674.         if( rc==SQLITE_OK && ((Fts3Table *)pCsr->base.pVtab)->zContentTbl==0 ){

  162675.           /* If no row was found and no error has occurred, then the %_content

  162676.           ** table is missing a row that is present in the full-text index.

  162677.           ** The data structures are corrupt.  */

  162678.           rc = FTS_CORRUPT_VTAB;

  162679.           pCsr->isEof = 1;

  162680.         }

  162681.       }

  162682.     }

  162683.   }

  162684. 

  162685.   if( rc!=SQLITE_OK && pContext ){

  162686.     sqlite3_result_error_code(pContext, rc);

  162687.   }

  162688.   return rc;

  162689. }

  162690. 

  162691. /*

  162692. ** This function is used to process a single interior node when searching

  162693. ** a b-tree for a term or term prefix. The node data is passed to this 

  162694. ** function via the zNode/nNode parameters. The term to search for is

  162695. ** passed in zTerm/nTerm.

  162696. **

  162697. ** If piFirst is not NULL, then this function sets *piFirst to the blockid

  162698. ** of the child node that heads the sub-tree that may contain the term.

  162699. **

  162700. ** If piLast is not NULL, then *piLast is set to the right-most child node

  162701. ** that heads a sub-tree that may contain a term for which zTerm/nTerm is

  162702. ** a prefix.

  162703. **

  162704. ** If an OOM error occurs, SQLITE_NOMEM is returned. Otherwise, SQLITE_OK.

  162705. */

  162706. static int fts3ScanInteriorNode(

  162707.   const char *zTerm,              /* Term to select leaves for */

  162708.   int nTerm,                      /* Size of term zTerm in bytes */

  162709.   const char *zNode,              /* Buffer containing segment interior node */

  162710.   int nNode,                      /* Size of buffer at zNode */

  162711.   sqlite3_int64 *piFirst,         /* OUT: Selected child node */

  162712.   sqlite3_int64 *piLast           /* OUT: Selected child node */

  162713. ){

  162714.   int rc = SQLITE_OK;             /* Return code */

  162715.   const char *zCsr = zNode;       /* Cursor to iterate through node */

  162716.   const char *zEnd = &zCsr[nNode];/* End of interior node buffer */

  162717.   char *zBuffer = 0;              /* Buffer to load terms into */

  162718.   i64 nAlloc = 0;                 /* Size of allocated buffer */

  162719.   int isFirstTerm = 1;            /* True when processing first term on page */

  162720.   sqlite3_int64 iChild;           /* Block id of child node to descend to */

  162721. 

  162722.   /* Skip over the 'height' varint that occurs at the start of every 

  162723.   ** interior node. Then load the blockid of the left-child of the b-tree

  162724.   ** node into variable iChild.  

  162725.   **

  162726.   ** Even if the data structure on disk is corrupted, this (reading two

  162727.   ** varints from the buffer) does not risk an overread. If zNode is a

  162728.   ** root node, then the buffer comes from a SELECT statement. SQLite does

  162729.   ** not make this guarantee explicitly, but in practice there are always

  162730.   ** either more than 20 bytes of allocated space following the nNode bytes of

  162731.   ** contents, or two zero bytes. Or, if the node is read from the %_segments

  162732.   ** table, then there are always 20 bytes of zeroed padding following the

  162733.   ** nNode bytes of content (see sqlite3Fts3ReadBlock() for details).

  162734.   */

  162735.   zCsr += sqlite3Fts3GetVarint(zCsr, &iChild);

  162736.   zCsr += sqlite3Fts3GetVarint(zCsr, &iChild);

  162737.   if( zCsr>zEnd ){

  162738.     return FTS_CORRUPT_VTAB;

  162739.   }

  162740.   

  162741.   while( zCsr<zEnd && (piFirst || piLast) ){

  162742.     int cmp;                      /* memcmp() result */

  162743.     int nSuffix;                  /* Size of term suffix */

  162744.     int nPrefix = 0;              /* Size of term prefix */

  162745.     int nBuffer;                  /* Total term size */

  162746.   

  162747.     /* Load the next term on the node into zBuffer. Use realloc() to expand

  162748.     ** the size of zBuffer if required.  */

  162749.     if( !isFirstTerm ){

  162750.       zCsr += fts3GetVarint32(zCsr, &nPrefix);

  162751.     }

  162752.     isFirstTerm = 0;

  162753.     zCsr += fts3GetVarint32(zCsr, &nSuffix);

  162754.     

  162755.     assert( nPrefix>=0 && nSuffix>=0 );

  162756.     if( nPrefix>zCsr-zNode || nSuffix>zEnd-zCsr || nSuffix==0 ){

  162757.       rc = FTS_CORRUPT_VTAB;

  162758.       goto finish_scan;

  162759.     }

  162760.     if( (i64)nPrefix+nSuffix>nAlloc ){

  162761.       char *zNew;

  162762.       nAlloc = ((i64)nPrefix+nSuffix) * 2;

  162763.       zNew = (char *)sqlite3_realloc64(zBuffer, nAlloc);

  162764.       if( !zNew ){

  162765.         rc = SQLITE_NOMEM;

  162766.         goto finish_scan;

  162767.       }

  162768.       zBuffer = zNew;

  162769.     }

  162770.     assert( zBuffer );

  162771.     memcpy(&zBuffer[nPrefix], zCsr, nSuffix);

  162772.     nBuffer = nPrefix + nSuffix;

  162773.     zCsr += nSuffix;

  162774. 

  162775.     /* Compare the term we are searching for with the term just loaded from

  162776.     ** the interior node. If the specified term is greater than or equal

  162777.     ** to the term from the interior node, then all terms on the sub-tree 

  162778.     ** headed by node iChild are smaller than zTerm. No need to search 

  162779.     ** iChild.

  162780.     **

  162781.     ** If the interior node term is larger than the specified term, then

  162782.     ** the tree headed by iChild may contain the specified term.

  162783.     */

  162784.     cmp = memcmp(zTerm, zBuffer, (nBuffer>nTerm ? nTerm : nBuffer));

  162785.     if( piFirst && (cmp<0 || (cmp==0 && nBuffer>nTerm)) ){

  162786.       *piFirst = iChild;

  162787.       piFirst = 0;

  162788.     }

  162789. 

  162790.     if( piLast && cmp<0 ){

  162791.       *piLast = iChild;

  162792.       piLast = 0;

  162793.     }

  162794. 

  162795.     iChild++;

  162796.   };

  162797. 

  162798.   if( piFirst ) *piFirst = iChild;

  162799.   if( piLast ) *piLast = iChild;

  162800. 

  162801.  finish_scan:

  162802.   sqlite3_free(zBuffer);

  162803.   return rc;

  162804. }

  162805. 

  162806. 

  162807. /*

  162808. ** The buffer pointed to by argument zNode (size nNode bytes) contains an

  162809. ** interior node of a b-tree segment. The zTerm buffer (size nTerm bytes)

  162810. ** contains a term. This function searches the sub-tree headed by the zNode

  162811. ** node for the range of leaf nodes that may contain the specified term

  162812. ** or terms for which the specified term is a prefix.

  162813. **

  162814. ** If piLeaf is not NULL, then *piLeaf is set to the blockid of the 

  162815. ** left-most leaf node in the tree that may contain the specified term.

  162816. ** If piLeaf2 is not NULL, then *piLeaf2 is set to the blockid of the

  162817. ** right-most leaf node that may contain a term for which the specified

  162818. ** term is a prefix.

  162819. **

  162820. ** It is possible that the range of returned leaf nodes does not contain 

  162821. ** the specified term or any terms for which it is a prefix. However, if the 

  162822. ** segment does contain any such terms, they are stored within the identified

  162823. ** range. Because this function only inspects interior segment nodes (and

  162824. ** never loads leaf nodes into memory), it is not possible to be sure.

  162825. **

  162826. ** If an error occurs, an error code other than SQLITE_OK is returned.

  162827. */ 

  162828. static int fts3SelectLeaf(

  162829.   Fts3Table *p,                   /* Virtual table handle */

  162830.   const char *zTerm,              /* Term to select leaves for */

  162831.   int nTerm,                      /* Size of term zTerm in bytes */

  162832.   const char *zNode,              /* Buffer containing segment interior node */

  162833.   int nNode,                      /* Size of buffer at zNode */

  162834.   sqlite3_int64 *piLeaf,          /* Selected leaf node */

  162835.   sqlite3_int64 *piLeaf2          /* Selected leaf node */

  162836. ){

  162837.   int rc = SQLITE_OK;             /* Return code */

  162838.   int iHeight;                    /* Height of this node in tree */

  162839. 

  162840.   assert( piLeaf || piLeaf2 );

  162841. 

  162842.   fts3GetVarint32(zNode, &iHeight);

  162843.   rc = fts3ScanInteriorNode(zTerm, nTerm, zNode, nNode, piLeaf, piLeaf2);

  162844.   assert( !piLeaf2 || !piLeaf || rc!=SQLITE_OK || (*piLeaf<=*piLeaf2) );

  162845. 

  162846.   if( rc==SQLITE_OK && iHeight>1 ){

  162847.     char *zBlob = 0;              /* Blob read from %_segments table */

  162848.     int nBlob = 0;                /* Size of zBlob in bytes */

  162849. 

  162850.     if( piLeaf && piLeaf2 && (*piLeaf!=*piLeaf2) ){

  162851.       rc = sqlite3Fts3ReadBlock(p, *piLeaf, &zBlob, &nBlob, 0);

  162852.       if( rc==SQLITE_OK ){

  162853.         rc = fts3SelectLeaf(p, zTerm, nTerm, zBlob, nBlob, piLeaf, 0);

  162854.       }

  162855.       sqlite3_free(zBlob);

  162856.       piLeaf = 0;

  162857.       zBlob = 0;

  162858.     }

  162859. 

  162860.     if( rc==SQLITE_OK ){

  162861.       rc = sqlite3Fts3ReadBlock(p, piLeaf?*piLeaf:*piLeaf2, &zBlob, &nBlob, 0);

  162862.     }

  162863.     if( rc==SQLITE_OK ){

  162864.       rc = fts3SelectLeaf(p, zTerm, nTerm, zBlob, nBlob, piLeaf, piLeaf2);

  162865.     }

  162866.     sqlite3_free(zBlob);

  162867.   }

  162868. 

  162869.   return rc;

  162870. }

  162871. 

  162872. /*

  162873. ** This function is used to create delta-encoded serialized lists of FTS3 

  162874. ** varints. Each call to this function appends a single varint to a list.

  162875. */

  162876. static void fts3PutDeltaVarint(

  162877.   char **pp,                      /* IN/OUT: Output pointer */

  162878.   sqlite3_int64 *piPrev,          /* IN/OUT: Previous value written to list */

  162879.   sqlite3_int64 iVal              /* Write this value to the list */

  162880. ){

  162881.   assert( iVal-*piPrev > 0 || (*piPrev==0 && iVal==0) );

  162882.   *pp += sqlite3Fts3PutVarint(*pp, iVal-*piPrev);

  162883.   *piPrev = iVal;

  162884. }

  162885. 

  162886. /*

  162887. ** When this function is called, *ppPoslist is assumed to point to the 

  162888. ** start of a position-list. After it returns, *ppPoslist points to the

  162889. ** first byte after the position-list.

  162890. **

  162891. ** A position list is list of positions (delta encoded) and columns for 

  162892. ** a single document record of a doclist.  So, in other words, this

  162893. ** routine advances *ppPoslist so that it points to the next docid in

  162894. ** the doclist, or to the first byte past the end of the doclist.

  162895. **

  162896. ** If pp is not NULL, then the contents of the position list are copied

  162897. ** to *pp. *pp is set to point to the first byte past the last byte copied

  162898. ** before this function returns.

  162899. */

  162900. static void fts3PoslistCopy(char **pp, char **ppPoslist){

  162901.   char *pEnd = *ppPoslist;

  162902.   char c = 0;

  162903. 

  162904.   /* The end of a position list is marked by a zero encoded as an FTS3 

  162905.   ** varint. A single POS_END (0) byte. Except, if the 0 byte is preceded by

  162906.   ** a byte with the 0x80 bit set, then it is not a varint 0, but the tail

  162907.   ** of some other, multi-byte, value.

  162908.   **

  162909.   ** The following while-loop moves pEnd to point to the first byte that is not 

  162910.   ** immediately preceded by a byte with the 0x80 bit set. Then increments

  162911.   ** pEnd once more so that it points to the byte immediately following the

  162912.   ** last byte in the position-list.

  162913.   */

  162914.   while( *pEnd | c ){

  162915.     c = *pEnd++ & 0x80;

  162916.     testcase( c!=0 && (*pEnd)==0 );

  162917.   }

  162918.   pEnd++;  /* Advance past the POS_END terminator byte */

  162919. 

  162920.   if( pp ){

  162921.     int n = (int)(pEnd - *ppPoslist);

  162922.     char *p = *pp;

  162923.     memcpy(p, *ppPoslist, n);

  162924.     p += n;

  162925.     *pp = p;

  162926.   }

  162927.   *ppPoslist = pEnd;

  162928. }

  162929. 

  162930. /*

  162931. ** When this function is called, *ppPoslist is assumed to point to the 

  162932. ** start of a column-list. After it returns, *ppPoslist points to the

  162933. ** to the terminator (POS_COLUMN or POS_END) byte of the column-list.

  162934. **

  162935. ** A column-list is list of delta-encoded positions for a single column

  162936. ** within a single document within a doclist.

  162937. **

  162938. ** The column-list is terminated either by a POS_COLUMN varint (1) or

  162939. ** a POS_END varint (0).  This routine leaves *ppPoslist pointing to

  162940. ** the POS_COLUMN or POS_END that terminates the column-list.

  162941. **

  162942. ** If pp is not NULL, then the contents of the column-list are copied

  162943. ** to *pp. *pp is set to point to the first byte past the last byte copied

  162944. ** before this function returns.  The POS_COLUMN or POS_END terminator

  162945. ** is not copied into *pp.

  162946. */

  162947. static void fts3ColumnlistCopy(char **pp, char **ppPoslist){

  162948.   char *pEnd = *ppPoslist;

  162949.   char c = 0;

  162950. 

  162951.   /* A column-list is terminated by either a 0x01 or 0x00 byte that is

  162952.   ** not part of a multi-byte varint.

  162953.   */

  162954.   while( 0xFE & (*pEnd | c) ){

  162955.     c = *pEnd++ & 0x80;

  162956.     testcase( c!=0 && ((*pEnd)&0xfe)==0 );

  162957.   }

  162958.   if( pp ){

  162959.     int n = (int)(pEnd - *ppPoslist);

  162960.     char *p = *pp;

  162961.     memcpy(p, *ppPoslist, n);

  162962.     p += n;

  162963.     *pp = p;

  162964.   }

  162965.   *ppPoslist = pEnd;

  162966. }

  162967. 

  162968. /*

  162969. ** Value used to signify the end of an position-list. This is safe because

  162970. ** it is not possible to have a document with 2^31 terms.

  162971. */

  162972. #define POSITION_LIST_END 0x7fffffff

  162973. 

  162974. /*

  162975. ** This function is used to help parse position-lists. When this function is

  162976. ** called, *pp may point to the start of the next varint in the position-list

  162977. ** being parsed, or it may point to 1 byte past the end of the position-list

  162978. ** (in which case **pp will be a terminator bytes POS_END (0) or

  162979. ** (1)).

  162980. **

  162981. ** If *pp points past the end of the current position-list, set *pi to 

  162982. ** POSITION_LIST_END and return. Otherwise, read the next varint from *pp,

  162983. ** increment the current value of *pi by the value read, and set *pp to

  162984. ** point to the next value before returning.

  162985. **

  162986. ** Before calling this routine *pi must be initialized to the value of

  162987. ** the previous position, or zero if we are reading the first position

  162988. ** in the position-list.  Because positions are delta-encoded, the value

  162989. ** of the previous position is needed in order to compute the value of

  162990. ** the next position.

  162991. */

  162992. static void fts3ReadNextPos(

  162993.   char **pp,                    /* IN/OUT: Pointer into position-list buffer */

  162994.   sqlite3_int64 *pi             /* IN/OUT: Value read from position-list */

  162995. ){

  162996.   if( (**pp)&0xFE ){

  162997.     fts3GetDeltaVarint(pp, pi);

  162998.     *pi -= 2;

  162999.   }else{

  163000.     *pi = POSITION_LIST_END;

  163001.   }

  163002. }

  163003. 

  163004. /*

  163005. ** If parameter iCol is not 0, write an POS_COLUMN (1) byte followed by

  163006. ** the value of iCol encoded as a varint to *pp.   This will start a new

  163007. ** column list.

  163008. **

  163009. ** Set *pp to point to the byte just after the last byte written before 

  163010. ** returning (do not modify it if iCol==0). Return the total number of bytes

  163011. ** written (0 if iCol==0).

  163012. */

  163013. static int fts3PutColNumber(char **pp, int iCol){

  163014.   int n = 0;                      /* Number of bytes written */

  163015.   if( iCol ){

  163016.     char *p = *pp;                /* Output pointer */

  163017.     n = 1 + sqlite3Fts3PutVarint(&p[1], iCol);

  163018.     *p = 0x01;

  163019.     *pp = &p[n];

  163020.   }

  163021.   return n;

  163022. }

  163023. 

  163024. /*

  163025. ** Compute the union of two position lists.  The output written

  163026. ** into *pp contains all positions of both *pp1 and *pp2 in sorted

  163027. ** order and with any duplicates removed.  All pointers are

  163028. ** updated appropriately.   The caller is responsible for insuring

  163029. ** that there is enough space in *pp to hold the complete output.

  163030. */

  163031. static int fts3PoslistMerge(

  163032.   char **pp,                      /* Output buffer */

  163033.   char **pp1,                     /* Left input list */

  163034.   char **pp2                      /* Right input list */

  163035. ){

  163036.   char *p = *pp;

  163037.   char *p1 = *pp1;

  163038.   char *p2 = *pp2;

  163039. 

  163040.   while( *p1 || *p2 ){

  163041.     int iCol1;         /* The current column index in pp1 */

  163042.     int iCol2;         /* The current column index in pp2 */

  163043. 

  163044.     if( *p1==POS_COLUMN ){ 

  163045.       fts3GetVarint32(&p1[1], &iCol1);

  163046.       if( iCol1==0 ) return FTS_CORRUPT_VTAB;

  163047.     }

  163048.     else if( *p1==POS_END ) iCol1 = POSITION_LIST_END;

  163049.     else iCol1 = 0;

  163050. 

  163051.     if( *p2==POS_COLUMN ){

  163052.       fts3GetVarint32(&p2[1], &iCol2);

  163053.       if( iCol2==0 ) return FTS_CORRUPT_VTAB;

  163054.     }

  163055.     else if( *p2==POS_END ) iCol2 = POSITION_LIST_END;

  163056.     else iCol2 = 0;

  163057. 

  163058.     if( iCol1==iCol2 ){

  163059.       sqlite3_int64 i1 = 0;       /* Last position from pp1 */

  163060.       sqlite3_int64 i2 = 0;       /* Last position from pp2 */

  163061.       sqlite3_int64 iPrev = 0;

  163062.       int n = fts3PutColNumber(&p, iCol1);

  163063.       p1 += n;

  163064.       p2 += n;

  163065. 

  163066.       /* At this point, both p1 and p2 point to the start of column-lists

  163067.       ** for the same column (the column with index iCol1 and iCol2).

  163068.       ** A column-list is a list of non-negative delta-encoded varints, each 

  163069.       ** incremented by 2 before being stored. Each list is terminated by a

  163070.       ** POS_END (0) or POS_COLUMN (1). The following block merges the two lists

  163071.       ** and writes the results to buffer p. p is left pointing to the byte

  163072.       ** after the list written. No terminator (POS_END or POS_COLUMN) is

  163073.       ** written to the output.

  163074.       */

  163075.       fts3GetDeltaVarint(&p1, &i1);

  163076.       fts3GetDeltaVarint(&p2, &i2);

  163077.       do {

  163078.         fts3PutDeltaVarint(&p, &iPrev, (i1<i2) ? i1 : i2); 

  163079.         iPrev -= 2;

  163080.         if( i1==i2 ){

  163081.           fts3ReadNextPos(&p1, &i1);

  163082.           fts3ReadNextPos(&p2, &i2);

  163083.         }else if( i1<i2 ){

  163084.           fts3ReadNextPos(&p1, &i1);

  163085.         }else{

  163086.           fts3ReadNextPos(&p2, &i2);

  163087.         }

  163088.       }while( i1!=POSITION_LIST_END || i2!=POSITION_LIST_END );

  163089.     }else if( iCol1<iCol2 ){

  163090.       p1 += fts3PutColNumber(&p, iCol1);

  163091.       fts3ColumnlistCopy(&p, &p1);

  163092.     }else{

  163093.       p2 += fts3PutColNumber(&p, iCol2);

  163094.       fts3ColumnlistCopy(&p, &p2);

  163095.     }

  163096.   }

  163097. 

  163098.   *p++ = POS_END;

  163099.   *pp = p;

  163100.   *pp1 = p1 + 1;

  163101.   *pp2 = p2 + 1;

  163102.   return SQLITE_OK;

  163103. }

  163104. 

  163105. /*

  163106. ** This function is used to merge two position lists into one. When it is

  163107. ** called, *pp1 and *pp2 must both point to position lists. A position-list is

  163108. ** the part of a doclist that follows each document id. For example, if a row

  163109. ** contains:

  163110. **

  163111. **     'a b c'|'x y z'|'a b b a'

  163112. **

  163113. ** Then the position list for this row for token 'b' would consist of:

  163114. **

  163115. **     0x02 0x01 0x02 0x03 0x03 0x00

  163116. **

  163117. ** When this function returns, both *pp1 and *pp2 are left pointing to the

  163118. ** byte following the 0x00 terminator of their respective position lists.

  163119. **

  163120. ** If isSaveLeft is 0, an entry is added to the output position list for 

  163121. ** each position in *pp2 for which there exists one or more positions in

  163122. ** *pp1 so that (pos(*pp2)>pos(*pp1) && pos(*pp2)-pos(*pp1)<=nToken). i.e.

  163123. ** when the *pp1 token appears before the *pp2 token, but not more than nToken

  163124. ** slots before it.

  163125. **

  163126. ** e.g. nToken==1 searches for adjacent positions.

  163127. */

  163128. static int fts3PoslistPhraseMerge(

  163129.   char **pp,                      /* IN/OUT: Preallocated output buffer */

  163130.   int nToken,                     /* Maximum difference in token positions */

  163131.   int isSaveLeft,                 /* Save the left position */

  163132.   int isExact,                    /* If *pp1 is exactly nTokens before *pp2 */

  163133.   char **pp1,                     /* IN/OUT: Left input list */

  163134.   char **pp2                      /* IN/OUT: Right input list */

  163135. ){

  163136.   char *p = *pp;

  163137.   char *p1 = *pp1;

  163138.   char *p2 = *pp2;

  163139.   int iCol1 = 0;

  163140.   int iCol2 = 0;

  163141. 

  163142.   /* Never set both isSaveLeft and isExact for the same invocation. */

  163143.   assert( isSaveLeft==0 || isExact==0 );

  163144. 

  163145.   assert( p!=0 && *p1!=0 && *p2!=0 );

  163146.   if( *p1==POS_COLUMN ){ 

  163147.     p1++;

  163148.     p1 += fts3GetVarint32(p1, &iCol1);

  163149.   }

  163150.   if( *p2==POS_COLUMN ){ 

  163151.     p2++;

  163152.     p2 += fts3GetVarint32(p2, &iCol2);

  163153.   }

  163154. 

  163155.   while( 1 ){

  163156.     if( iCol1==iCol2 ){

  163157.       char *pSave = p;

  163158.       sqlite3_int64 iPrev = 0;

  163159.       sqlite3_int64 iPos1 = 0;

  163160.       sqlite3_int64 iPos2 = 0;

  163161. 

  163162.       if( iCol1 ){

  163163.         *p++ = POS_COLUMN;

  163164.         p += sqlite3Fts3PutVarint(p, iCol1);

  163165.       }

  163166. 

  163167.       fts3GetDeltaVarint(&p1, &iPos1); iPos1 -= 2;

  163168.       fts3GetDeltaVarint(&p2, &iPos2); iPos2 -= 2;

  163169.       if( iPos1<0 || iPos2<0 ) break;

  163170. 

  163171.       while( 1 ){

  163172.         if( iPos2==iPos1+nToken 

  163173.          || (isExact==0 && iPos2>iPos1 && iPos2<=iPos1+nToken) 

  163174.         ){

  163175.           sqlite3_int64 iSave;

  163176.           iSave = isSaveLeft ? iPos1 : iPos2;

  163177.           fts3PutDeltaVarint(&p, &iPrev, iSave+2); iPrev -= 2;

  163178.           pSave = 0;

  163179.           assert( p );

  163180.         }

  163181.         if( (!isSaveLeft && iPos2<=(iPos1+nToken)) || iPos2<=iPos1 ){

  163182.           if( (*p2&0xFE)==0 ) break;

  163183.           fts3GetDeltaVarint(&p2, &iPos2); iPos2 -= 2;

  163184.         }else{

  163185.           if( (*p1&0xFE)==0 ) break;

  163186.           fts3GetDeltaVarint(&p1, &iPos1); iPos1 -= 2;

  163187.         }

  163188.       }

  163189. 

  163190.       if( pSave ){

  163191.         assert( pp && p );

  163192.         p = pSave;

  163193.       }

  163194. 

  163195.       fts3ColumnlistCopy(0, &p1);

  163196.       fts3ColumnlistCopy(0, &p2);

  163197.       assert( (*p1&0xFE)==0 && (*p2&0xFE)==0 );

  163198.       if( 0==*p1 || 0==*p2 ) break;

  163199. 

  163200.       p1++;

  163201.       p1 += fts3GetVarint32(p1, &iCol1);

  163202.       p2++;

  163203.       p2 += fts3GetVarint32(p2, &iCol2);

  163204.     }

  163205. 

  163206.     /* Advance pointer p1 or p2 (whichever corresponds to the smaller of

  163207.     ** iCol1 and iCol2) so that it points to either the 0x00 that marks the

  163208.     ** end of the position list, or the 0x01 that precedes the next 

  163209.     ** column-number in the position list. 

  163210.     */

  163211.     else if( iCol1<iCol2 ){

  163212.       fts3ColumnlistCopy(0, &p1);

  163213.       if( 0==*p1 ) break;

  163214.       p1++;

  163215.       p1 += fts3GetVarint32(p1, &iCol1);

  163216.     }else{

  163217.       fts3ColumnlistCopy(0, &p2);

  163218.       if( 0==*p2 ) break;

  163219.       p2++;

  163220.       p2 += fts3GetVarint32(p2, &iCol2);

  163221.     }

  163222.   }

  163223. 

  163224.   fts3PoslistCopy(0, &p2);

  163225.   fts3PoslistCopy(0, &p1);

  163226.   *pp1 = p1;

  163227.   *pp2 = p2;

  163228.   if( *pp==p ){

  163229.     return 0;

  163230.   }

  163231.   *p++ = 0x00;

  163232.   *pp = p;

  163233.   return 1;

  163234. }

  163235. 

  163236. /*

  163237. ** Merge two position-lists as required by the NEAR operator. The argument

  163238. ** position lists correspond to the left and right phrases of an expression 

  163239. ** like:

  163240. **

  163241. **     "phrase 1" NEAR "phrase number 2"

  163242. **

  163243. ** Position list *pp1 corresponds to the left-hand side of the NEAR 

  163244. ** expression and *pp2 to the right. As usual, the indexes in the position 

  163245. ** lists are the offsets of the last token in each phrase (tokens "1" and "2" 

  163246. ** in the example above).

  163247. **

  163248. ** The output position list - written to *pp - is a copy of *pp2 with those

  163249. ** entries that are not sufficiently NEAR entries in *pp1 removed.

  163250. */

  163251. static int fts3PoslistNearMerge(

  163252.   char **pp,                      /* Output buffer */

  163253.   char *aTmp,                     /* Temporary buffer space */

  163254.   int nRight,                     /* Maximum difference in token positions */

  163255.   int nLeft,                      /* Maximum difference in token positions */

  163256.   char **pp1,                     /* IN/OUT: Left input list */

  163257.   char **pp2                      /* IN/OUT: Right input list */

  163258. ){

  163259.   char *p1 = *pp1;

  163260.   char *p2 = *pp2;

  163261. 

  163262.   char *pTmp1 = aTmp;

  163263.   char *pTmp2;

  163264.   char *aTmp2;

  163265.   int res = 1;

  163266. 

  163267.   fts3PoslistPhraseMerge(&pTmp1, nRight, 0, 0, pp1, pp2);

  163268.   aTmp2 = pTmp2 = pTmp1;

  163269.   *pp1 = p1;

  163270.   *pp2 = p2;

  163271.   fts3PoslistPhraseMerge(&pTmp2, nLeft, 1, 0, pp2, pp1);

  163272.   if( pTmp1!=aTmp && pTmp2!=aTmp2 ){

  163273.     fts3PoslistMerge(pp, &aTmp, &aTmp2);

  163274.   }else if( pTmp1!=aTmp ){

  163275.     fts3PoslistCopy(pp, &aTmp);

  163276.   }else if( pTmp2!=aTmp2 ){

  163277.     fts3PoslistCopy(pp, &aTmp2);

  163278.   }else{

  163279.     res = 0;

  163280.   }

  163281. 

  163282.   return res;

  163283. }

  163284. 

  163285. /* 

  163286. ** An instance of this function is used to merge together the (potentially

  163287. ** large number of) doclists for each term that matches a prefix query.

  163288. ** See function fts3TermSelectMerge() for details.

  163289. */

  163290. typedef struct TermSelect TermSelect;

  163291. struct TermSelect {

  163292.   char *aaOutput[16];             /* Malloc'd output buffers */

  163293.   int anOutput[16];               /* Size each output buffer in bytes */

  163294. };

  163295. 

  163296. /*

  163297. ** This function is used to read a single varint from a buffer. Parameter

  163298. ** pEnd points 1 byte past the end of the buffer. When this function is

  163299. ** called, if *pp points to pEnd or greater, then the end of the buffer

  163300. ** has been reached. In this case *pp is set to 0 and the function returns.

  163301. **

  163302. ** If *pp does not point to or past pEnd, then a single varint is read

  163303. ** from *pp. *pp is then set to point 1 byte past the end of the read varint.

  163304. **

  163305. ** If bDescIdx is false, the value read is added to *pVal before returning.

  163306. ** If it is true, the value read is subtracted from *pVal before this 

  163307. ** function returns.

  163308. */

  163309. static void fts3GetDeltaVarint3(

  163310.   char **pp,                      /* IN/OUT: Point to read varint from */

  163311.   char *pEnd,                     /* End of buffer */

  163312.   int bDescIdx,                   /* True if docids are descending */

  163313.   sqlite3_int64 *pVal             /* IN/OUT: Integer value */

  163314. ){

  163315.   if( *pp>=pEnd ){

  163316.     *pp = 0;

  163317.   }else{

  163318.     sqlite3_int64 iVal;

  163319.     *pp += sqlite3Fts3GetVarint(*pp, &iVal);

  163320.     if( bDescIdx ){

  163321.       *pVal -= iVal;

  163322.     }else{

  163323.       *pVal += iVal;

  163324.     }

  163325.   }

  163326. }

  163327. 

  163328. /*

  163329. ** This function is used to write a single varint to a buffer. The varint

  163330. ** is written to *pp. Before returning, *pp is set to point 1 byte past the

  163331. ** end of the value written.

  163332. **

  163333. ** If *pbFirst is zero when this function is called, the value written to

  163334. ** the buffer is that of parameter iVal. 

  163335. **

  163336. ** If *pbFirst is non-zero when this function is called, then the value 

  163337. ** written is either (iVal-*piPrev) (if bDescIdx is zero) or (*piPrev-iVal)

  163338. ** (if bDescIdx is non-zero).

  163339. **

  163340. ** Before returning, this function always sets *pbFirst to 1 and *piPrev

  163341. ** to the value of parameter iVal.

  163342. */

  163343. static void fts3PutDeltaVarint3(

  163344.   char **pp,                      /* IN/OUT: Output pointer */

  163345.   int bDescIdx,                   /* True for descending docids */

  163346.   sqlite3_int64 *piPrev,          /* IN/OUT: Previous value written to list */

  163347.   int *pbFirst,                   /* IN/OUT: True after first int written */

  163348.   sqlite3_int64 iVal              /* Write this value to the list */

  163349. ){

  163350.   sqlite3_int64 iWrite;

  163351.   if( bDescIdx==0 || *pbFirst==0 ){

  163352.     iWrite = iVal - *piPrev;

  163353.   }else{

  163354.     iWrite = *piPrev - iVal;

  163355.   }

  163356.   assert( *pbFirst || *piPrev==0 );

  163357.   assert( *pbFirst==0 || iWrite>0 );

  163358.   *pp += sqlite3Fts3PutVarint(*pp, iWrite);

  163359.   *piPrev = iVal;

  163360.   *pbFirst = 1;

  163361. }

  163362. 

  163363. 

  163364. /*

  163365. ** This macro is used by various functions that merge doclists. The two

  163366. ** arguments are 64-bit docid values. If the value of the stack variable

  163367. ** bDescDoclist is 0 when this macro is invoked, then it returns (i1-i2). 

  163368. ** Otherwise, (i2-i1).

  163369. **

  163370. ** Using this makes it easier to write code that can merge doclists that are

  163371. ** sorted in either ascending or descending order.

  163372. */

  163373. #define DOCID_CMP(i1, i2) ((bDescDoclist?-1:1) * (i1-i2))

  163374. 

  163375. /*

  163376. ** This function does an "OR" merge of two doclists (output contains all

  163377. ** positions contained in either argument doclist). If the docids in the 

  163378. ** input doclists are sorted in ascending order, parameter bDescDoclist

  163379. ** should be false. If they are sorted in ascending order, it should be

  163380. ** passed a non-zero value.

  163381. **

  163382. ** If no error occurs, *paOut is set to point at an sqlite3_malloc'd buffer

  163383. ** containing the output doclist and SQLITE_OK is returned. In this case

  163384. ** *pnOut is set to the number of bytes in the output doclist.

  163385. **

  163386. ** If an error occurs, an SQLite error code is returned. The output values

  163387. ** are undefined in this case.

  163388. */

  163389. static int fts3DoclistOrMerge(

  163390.   int bDescDoclist,               /* True if arguments are desc */

  163391.   char *a1, int n1,               /* First doclist */

  163392.   char *a2, int n2,               /* Second doclist */

  163393.   char **paOut, int *pnOut        /* OUT: Malloc'd doclist */

  163394. ){

  163395.   int rc = SQLITE_OK;

  163396.   sqlite3_int64 i1 = 0;

  163397.   sqlite3_int64 i2 = 0;

  163398.   sqlite3_int64 iPrev = 0;

  163399.   char *pEnd1 = &a1[n1];

  163400.   char *pEnd2 = &a2[n2];

  163401.   char *p1 = a1;

  163402.   char *p2 = a2;

  163403.   char *p;

  163404.   char *aOut;

  163405.   int bFirstOut = 0;

  163406. 

  163407.   *paOut = 0;

  163408.   *pnOut = 0;

  163409. 

  163410.   /* Allocate space for the output. Both the input and output doclists

  163411.   ** are delta encoded. If they are in ascending order (bDescDoclist==0),

  163412.   ** then the first docid in each list is simply encoded as a varint. For

  163413.   ** each subsequent docid, the varint stored is the difference between the

  163414.   ** current and previous docid (a positive number - since the list is in

  163415.   ** ascending order).

  163416.   **

  163417.   ** The first docid written to the output is therefore encoded using the 

  163418.   ** same number of bytes as it is in whichever of the input lists it is

  163419.   ** read from. And each subsequent docid read from the same input list 

  163420.   ** consumes either the same or less bytes as it did in the input (since

  163421.   ** the difference between it and the previous value in the output must

  163422.   ** be a positive value less than or equal to the delta value read from 

  163423.   ** the input list). The same argument applies to all but the first docid

  163424.   ** read from the 'other' list. And to the contents of all position lists

  163425.   ** that will be copied and merged from the input to the output.

  163426.   **

  163427.   ** However, if the first docid copied to the output is a negative number,

  163428.   ** then the encoding of the first docid from the 'other' input list may

  163429.   ** be larger in the output than it was in the input (since the delta value

  163430.   ** may be a larger positive integer than the actual docid).

  163431.   **

  163432.   ** The space required to store the output is therefore the sum of the

  163433.   ** sizes of the two inputs, plus enough space for exactly one of the input

  163434.   ** docids to grow. 

  163435.   **

  163436.   ** A symetric argument may be made if the doclists are in descending 

  163437.   ** order.

  163438.   */

  163439.   aOut = sqlite3_malloc64((i64)n1+n2+FTS3_VARINT_MAX-1+FTS3_BUFFER_PADDING);

  163440.   if( !aOut ) return SQLITE_NOMEM;

  163441. 

  163442.   p = aOut;

  163443.   fts3GetDeltaVarint3(&p1, pEnd1, 0, &i1);

  163444.   fts3GetDeltaVarint3(&p2, pEnd2, 0, &i2);

  163445.   while( p1 || p2 ){

  163446.     sqlite3_int64 iDiff = DOCID_CMP(i1, i2);

  163447. 

  163448.     if( p2 && p1 && iDiff==0 ){

  163449.       fts3PutDeltaVarint3(&p, bDescDoclist, &iPrev, &bFirstOut, i1);

  163450.       rc = fts3PoslistMerge(&p, &p1, &p2);

  163451.       if( rc ) break;

  163452.       fts3GetDeltaVarint3(&p1, pEnd1, bDescDoclist, &i1);

  163453.       fts3GetDeltaVarint3(&p2, pEnd2, bDescDoclist, &i2);

  163454.     }else if( !p2 || (p1 && iDiff<0) ){

  163455.       fts3PutDeltaVarint3(&p, bDescDoclist, &iPrev, &bFirstOut, i1);

  163456.       fts3PoslistCopy(&p, &p1);

  163457.       fts3GetDeltaVarint3(&p1, pEnd1, bDescDoclist, &i1);

  163458.     }else{

  163459.       fts3PutDeltaVarint3(&p, bDescDoclist, &iPrev, &bFirstOut, i2);

  163460.       fts3PoslistCopy(&p, &p2);

  163461.       fts3GetDeltaVarint3(&p2, pEnd2, bDescDoclist, &i2);

  163462.     }

  163463.   }

  163464. 

  163465.   if( rc!=SQLITE_OK ){

  163466.     sqlite3_free(aOut);

  163467.     p = aOut = 0;

  163468.   }else{

  163469.     assert( (p-aOut)<=n1+n2+FTS3_VARINT_MAX-1 );

  163470.     memset(&aOut[(p-aOut)], 0, FTS3_BUFFER_PADDING);

  163471.   }

  163472.   *paOut = aOut;

  163473.   *pnOut = (int)(p-aOut);

  163474.   return rc;

  163475. }

  163476. 

  163477. /*

  163478. ** This function does a "phrase" merge of two doclists. In a phrase merge,

  163479. ** the output contains a copy of each position from the right-hand input

  163480. ** doclist for which there is a position in the left-hand input doclist

  163481. ** exactly nDist tokens before it.

  163482. **

  163483. ** If the docids in the input doclists are sorted in ascending order,

  163484. ** parameter bDescDoclist should be false. If they are sorted in ascending 

  163485. ** order, it should be passed a non-zero value.

  163486. **

  163487. ** The right-hand input doclist is overwritten by this function.

  163488. */

  163489. static int fts3DoclistPhraseMerge(

  163490.   int bDescDoclist,               /* True if arguments are desc */

  163491.   int nDist,                      /* Distance from left to right (1=adjacent) */

  163492.   char *aLeft, int nLeft,         /* Left doclist */

  163493.   char **paRight, int *pnRight    /* IN/OUT: Right/output doclist */

  163494. ){

  163495.   sqlite3_int64 i1 = 0;

  163496.   sqlite3_int64 i2 = 0;

  163497.   sqlite3_int64 iPrev = 0;

  163498.   char *aRight = *paRight;

  163499.   char *pEnd1 = &aLeft[nLeft];

  163500.   char *pEnd2 = &aRight[*pnRight];

  163501.   char *p1 = aLeft;

  163502.   char *p2 = aRight;

  163503.   char *p;

  163504.   int bFirstOut = 0;

  163505.   char *aOut;

  163506. 

  163507.   assert( nDist>0 );

  163508.   if( bDescDoclist ){

  163509.     aOut = sqlite3_malloc64((sqlite3_int64)*pnRight + FTS3_VARINT_MAX);

  163510.     if( aOut==0 ) return SQLITE_NOMEM;

  163511.   }else{

  163512.     aOut = aRight;

  163513.   }

  163514.   p = aOut;

  163515. 

  163516.   fts3GetDeltaVarint3(&p1, pEnd1, 0, &i1);

  163517.   fts3GetDeltaVarint3(&p2, pEnd2, 0, &i2);

  163518. 

  163519.   while( p1 && p2 ){

  163520.     sqlite3_int64 iDiff = DOCID_CMP(i1, i2);

  163521.     if( iDiff==0 ){

  163522.       char *pSave = p;

  163523.       sqlite3_int64 iPrevSave = iPrev;

  163524.       int bFirstOutSave = bFirstOut;

  163525. 

  163526.       fts3PutDeltaVarint3(&p, bDescDoclist, &iPrev, &bFirstOut, i1);

  163527.       if( 0==fts3PoslistPhraseMerge(&p, nDist, 0, 1, &p1, &p2) ){

  163528.         p = pSave;

  163529.         iPrev = iPrevSave;

  163530.         bFirstOut = bFirstOutSave;

  163531.       }

  163532.       fts3GetDeltaVarint3(&p1, pEnd1, bDescDoclist, &i1);

  163533.       fts3GetDeltaVarint3(&p2, pEnd2, bDescDoclist, &i2);

  163534.     }else if( iDiff<0 ){

  163535.       fts3PoslistCopy(0, &p1);

  163536.       fts3GetDeltaVarint3(&p1, pEnd1, bDescDoclist, &i1);

  163537.     }else{

  163538.       fts3PoslistCopy(0, &p2);

  163539.       fts3GetDeltaVarint3(&p2, pEnd2, bDescDoclist, &i2);

  163540.     }

  163541.   }

  163542. 

  163543.   *pnRight = (int)(p - aOut);

  163544.   if( bDescDoclist ){

  163545.     sqlite3_free(aRight);

  163546.     *paRight = aOut;

  163547.   }

  163548. 

  163549.   return SQLITE_OK;

  163550. }

  163551. 

  163552. /*

  163553. ** Argument pList points to a position list nList bytes in size. This

  163554. ** function checks to see if the position list contains any entries for

  163555. ** a token in position 0 (of any column). If so, it writes argument iDelta

  163556. ** to the output buffer pOut, followed by a position list consisting only

  163557. ** of the entries from pList at position 0, and terminated by an 0x00 byte.

  163558. ** The value returned is the number of bytes written to pOut (if any).

  163559. */

  163560. SQLITE_PRIVATE int sqlite3Fts3FirstFilter(

  163561.   sqlite3_int64 iDelta,           /* Varint that may be written to pOut */

  163562.   char *pList,                    /* Position list (no 0x00 term) */

  163563.   int nList,                      /* Size of pList in bytes */

  163564.   char *pOut                      /* Write output here */

  163565. ){

  163566.   int nOut = 0;

  163567.   int bWritten = 0;               /* True once iDelta has been written */

  163568.   char *p = pList;

  163569.   char *pEnd = &pList[nList];

  163570. 

  163571.   if( *p!=0x01 ){

  163572.     if( *p==0x02 ){

  163573.       nOut += sqlite3Fts3PutVarint(&pOut[nOut], iDelta);

  163574.       pOut[nOut++] = 0x02;

  163575.       bWritten = 1;

  163576.     }

  163577.     fts3ColumnlistCopy(0, &p);

  163578.   }

  163579. 

  163580.   while( p<pEnd ){

  163581.     sqlite3_int64 iCol;

  163582.     p++;

  163583.     p += sqlite3Fts3GetVarint(p, &iCol);

  163584.     if( *p==0x02 ){

  163585.       if( bWritten==0 ){

  163586.         nOut += sqlite3Fts3PutVarint(&pOut[nOut], iDelta);

  163587.         bWritten = 1;

  163588.       }

  163589.       pOut[nOut++] = 0x01;

  163590.       nOut += sqlite3Fts3PutVarint(&pOut[nOut], iCol);

  163591.       pOut[nOut++] = 0x02;

  163592.     }

  163593.     fts3ColumnlistCopy(0, &p);

  163594.   }

  163595.   if( bWritten ){

  163596.     pOut[nOut++] = 0x00;

  163597.   }

  163598. 

  163599.   return nOut;

  163600. }

  163601. 

  163602. 

  163603. /*

  163604. ** Merge all doclists in the TermSelect.aaOutput[] array into a single

  163605. ** doclist stored in TermSelect.aaOutput[0]. If successful, delete all

  163606. ** other doclists (except the aaOutput[0] one) and return SQLITE_OK.

  163607. **

  163608. ** If an OOM error occurs, return SQLITE_NOMEM. In this case it is

  163609. ** the responsibility of the caller to free any doclists left in the

  163610. ** TermSelect.aaOutput[] array.

  163611. */

  163612. static int fts3TermSelectFinishMerge(Fts3Table *p, TermSelect *pTS){

  163613.   char *aOut = 0;

  163614.   int nOut = 0;

  163615.   int i;

  163616. 

  163617.   /* Loop through the doclists in the aaOutput[] array. Merge them all

  163618.   ** into a single doclist.

  163619.   */

  163620.   for(i=0; i<SizeofArray(pTS->aaOutput); i++){

  163621.     if( pTS->aaOutput[i] ){

  163622.       if( !aOut ){

  163623.         aOut = pTS->aaOutput[i];

  163624.         nOut = pTS->anOutput[i];

  163625.         pTS->aaOutput[i] = 0;

  163626.       }else{

  163627.         int nNew;

  163628.         char *aNew;

  163629. 

  163630.         int rc = fts3DoclistOrMerge(p->bDescIdx, 

  163631.             pTS->aaOutput[i], pTS->anOutput[i], aOut, nOut, &aNew, &nNew

  163632.         );

  163633.         if( rc!=SQLITE_OK ){

  163634.           sqlite3_free(aOut);

  163635.           return rc;

  163636.         }

  163637. 

  163638.         sqlite3_free(pTS->aaOutput[i]);

  163639.         sqlite3_free(aOut);

  163640.         pTS->aaOutput[i] = 0;

  163641.         aOut = aNew;

  163642.         nOut = nNew;

  163643.       }

  163644.     }

  163645.   }

  163646. 

  163647.   pTS->aaOutput[0] = aOut;

  163648.   pTS->anOutput[0] = nOut;

  163649.   return SQLITE_OK;

  163650. }

  163651. 

  163652. /*

  163653. ** Merge the doclist aDoclist/nDoclist into the TermSelect object passed

  163654. ** as the first argument. The merge is an "OR" merge (see function

  163655. ** fts3DoclistOrMerge() for details).

  163656. **

  163657. ** This function is called with the doclist for each term that matches

  163658. ** a queried prefix. It merges all these doclists into one, the doclist

  163659. ** for the specified prefix. Since there can be a very large number of

  163660. ** doclists to merge, the merging is done pair-wise using the TermSelect

  163661. ** object.

  163662. **

  163663. ** This function returns SQLITE_OK if the merge is successful, or an

  163664. ** SQLite error code (SQLITE_NOMEM) if an error occurs.

  163665. */

  163666. static int fts3TermSelectMerge(

  163667.   Fts3Table *p,                   /* FTS table handle */

  163668.   TermSelect *pTS,                /* TermSelect object to merge into */

  163669.   char *aDoclist,                 /* Pointer to doclist */

  163670.   int nDoclist                    /* Size of aDoclist in bytes */

  163671. ){

  163672.   if( pTS->aaOutput[0]==0 ){

  163673.     /* If this is the first term selected, copy the doclist to the output

  163674.     ** buffer using memcpy(). 

  163675.     **

  163676.     ** Add FTS3_VARINT_MAX bytes of unused space to the end of the 

  163677.     ** allocation. This is so as to ensure that the buffer is big enough

  163678.     ** to hold the current doclist AND'd with any other doclist. If the

  163679.     ** doclists are stored in order=ASC order, this padding would not be

  163680.     ** required (since the size of [doclistA AND doclistB] is always less

  163681.     ** than or equal to the size of [doclistA] in that case). But this is

  163682.     ** not true for order=DESC. For example, a doclist containing (1, -1) 

  163683.     ** may be smaller than (-1), as in the first example the -1 may be stored

  163684.     ** as a single-byte delta, whereas in the second it must be stored as a

  163685.     ** FTS3_VARINT_MAX byte varint.

  163686.     **

  163687.     ** Similar padding is added in the fts3DoclistOrMerge() function.

  163688.     */

  163689.     pTS->aaOutput[0] = sqlite3_malloc(nDoclist + FTS3_VARINT_MAX + 1);

  163690.     pTS->anOutput[0] = nDoclist;

  163691.     if( pTS->aaOutput[0] ){

  163692.       memcpy(pTS->aaOutput[0], aDoclist, nDoclist);

  163693.       memset(&pTS->aaOutput[0][nDoclist], 0, FTS3_VARINT_MAX);

  163694.     }else{

  163695.       return SQLITE_NOMEM;

  163696.     }

  163697.   }else{

  163698.     char *aMerge = aDoclist;

  163699.     int nMerge = nDoclist;

  163700.     int iOut;

  163701. 

  163702.     for(iOut=0; iOut<SizeofArray(pTS->aaOutput); iOut++){

  163703.       if( pTS->aaOutput[iOut]==0 ){

  163704.         assert( iOut>0 );

  163705.         pTS->aaOutput[iOut] = aMerge;

  163706.         pTS->anOutput[iOut] = nMerge;

  163707.         break;

  163708.       }else{

  163709.         char *aNew;

  163710.         int nNew;

  163711. 

  163712.         int rc = fts3DoclistOrMerge(p->bDescIdx, aMerge, nMerge, 

  163713.             pTS->aaOutput[iOut], pTS->anOutput[iOut], &aNew, &nNew

  163714.         );

  163715.         if( rc!=SQLITE_OK ){

  163716.           if( aMerge!=aDoclist ) sqlite3_free(aMerge);

  163717.           return rc;

  163718.         }

  163719. 

  163720.         if( aMerge!=aDoclist ) sqlite3_free(aMerge);

  163721.         sqlite3_free(pTS->aaOutput[iOut]);

  163722.         pTS->aaOutput[iOut] = 0;

  163723.   

  163724.         aMerge = aNew;

  163725.         nMerge = nNew;

  163726.         if( (iOut+1)==SizeofArray(pTS->aaOutput) ){

  163727.           pTS->aaOutput[iOut] = aMerge;

  163728.           pTS->anOutput[iOut] = nMerge;

  163729.         }

  163730.       }

  163731.     }

  163732.   }

  163733.   return SQLITE_OK;

  163734. }

  163735. 

  163736. /*

  163737. ** Append SegReader object pNew to the end of the pCsr->apSegment[] array.

  163738. */

  163739. static int fts3SegReaderCursorAppend(

  163740.   Fts3MultiSegReader *pCsr, 

  163741.   Fts3SegReader *pNew

  163742. ){

  163743.   if( (pCsr->nSegment%16)==0 ){

  163744.     Fts3SegReader **apNew;

  163745.     sqlite3_int64 nByte = (pCsr->nSegment + 16)*sizeof(Fts3SegReader*);

  163746.     apNew = (Fts3SegReader **)sqlite3_realloc64(pCsr->apSegment, nByte);

  163747.     if( !apNew ){

  163748.       sqlite3Fts3SegReaderFree(pNew);

  163749.       return SQLITE_NOMEM;

  163750.     }

  163751.     pCsr->apSegment = apNew;

  163752.   }

  163753.   pCsr->apSegment[pCsr->nSegment++] = pNew;

  163754.   return SQLITE_OK;

  163755. }

  163756. 

  163757. /*

  163758. ** Add seg-reader objects to the Fts3MultiSegReader object passed as the

  163759. ** 8th argument.

  163760. **

  163761. ** This function returns SQLITE_OK if successful, or an SQLite error code

  163762. ** otherwise.

  163763. */

  163764. static int fts3SegReaderCursor(

  163765.   Fts3Table *p,                   /* FTS3 table handle */

  163766.   int iLangid,                    /* Language id */

  163767.   int iIndex,                     /* Index to search (from 0 to p->nIndex-1) */

  163768.   int iLevel,                     /* Level of segments to scan */

  163769.   const char *zTerm,              /* Term to query for */

  163770.   int nTerm,                      /* Size of zTerm in bytes */

  163771.   int isPrefix,                   /* True for a prefix search */

  163772.   int isScan,                     /* True to scan from zTerm to EOF */

  163773.   Fts3MultiSegReader *pCsr        /* Cursor object to populate */

  163774. ){

  163775.   int rc = SQLITE_OK;             /* Error code */

  163776.   sqlite3_stmt *pStmt = 0;        /* Statement to iterate through segments */

  163777.   int rc2;                        /* Result of sqlite3_reset() */

  163778. 

  163779.   /* If iLevel is less than 0 and this is not a scan, include a seg-reader 

  163780.   ** for the pending-terms. If this is a scan, then this call must be being

  163781.   ** made by an fts4aux module, not an FTS table. In this case calling

  163782.   ** Fts3SegReaderPending might segfault, as the data structures used by 

  163783.   ** fts4aux are not completely populated. So it's easiest to filter these

  163784.   ** calls out here.  */

  163785.   if( iLevel<0 && p->aIndex ){

  163786.     Fts3SegReader *pSeg = 0;

  163787.     rc = sqlite3Fts3SegReaderPending(p, iIndex, zTerm, nTerm, isPrefix||isScan, &pSeg);

  163788.     if( rc==SQLITE_OK && pSeg ){

  163789.       rc = fts3SegReaderCursorAppend(pCsr, pSeg);

  163790.     }

  163791.   }

  163792. 

  163793.   if( iLevel!=FTS3_SEGCURSOR_PENDING ){

  163794.     if( rc==SQLITE_OK ){

  163795.       rc = sqlite3Fts3AllSegdirs(p, iLangid, iIndex, iLevel, &pStmt);

  163796.     }

  163797. 

  163798.     while( rc==SQLITE_OK && SQLITE_ROW==(rc = sqlite3_step(pStmt)) ){

  163799.       Fts3SegReader *pSeg = 0;

  163800. 

  163801.       /* Read the values returned by the SELECT into local variables. */

  163802.       sqlite3_int64 iStartBlock = sqlite3_column_int64(pStmt, 1);

  163803.       sqlite3_int64 iLeavesEndBlock = sqlite3_column_int64(pStmt, 2);

  163804.       sqlite3_int64 iEndBlock = sqlite3_column_int64(pStmt, 3);

  163805.       int nRoot = sqlite3_column_bytes(pStmt, 4);

  163806.       char const *zRoot = sqlite3_column_blob(pStmt, 4);

  163807. 

  163808.       /* If zTerm is not NULL, and this segment is not stored entirely on its

  163809.       ** root node, the range of leaves scanned can be reduced. Do this. */

  163810.       if( iStartBlock && zTerm && zRoot ){

  163811.         sqlite3_int64 *pi = (isPrefix ? &iLeavesEndBlock : 0);

  163812.         rc = fts3SelectLeaf(p, zTerm, nTerm, zRoot, nRoot, &iStartBlock, pi);

  163813.         if( rc!=SQLITE_OK ) goto finished;

  163814.         if( isPrefix==0 && isScan==0 ) iLeavesEndBlock = iStartBlock;

  163815.       }

  163816.  

  163817.       rc = sqlite3Fts3SegReaderNew(pCsr->nSegment+1, 

  163818.           (isPrefix==0 && isScan==0),

  163819.           iStartBlock, iLeavesEndBlock, 

  163820.           iEndBlock, zRoot, nRoot, &pSeg

  163821.       );

  163822.       if( rc!=SQLITE_OK ) goto finished;

  163823.       rc = fts3SegReaderCursorAppend(pCsr, pSeg);

  163824.     }

  163825.   }

  163826. 

  163827.  finished:

  163828.   rc2 = sqlite3_reset(pStmt);

  163829.   if( rc==SQLITE_DONE ) rc = rc2;

  163830. 

  163831.   return rc;

  163832. }

  163833. 

  163834. /*

  163835. ** Set up a cursor object for iterating through a full-text index or a 

  163836. ** single level therein.

  163837. */

  163838. SQLITE_PRIVATE int sqlite3Fts3SegReaderCursor(

  163839.   Fts3Table *p,                   /* FTS3 table handle */

  163840.   int iLangid,                    /* Language-id to search */

  163841.   int iIndex,                     /* Index to search (from 0 to p->nIndex-1) */

  163842.   int iLevel,                     /* Level of segments to scan */

  163843.   const char *zTerm,              /* Term to query for */

  163844.   int nTerm,                      /* Size of zTerm in bytes */

  163845.   int isPrefix,                   /* True for a prefix search */

  163846.   int isScan,                     /* True to scan from zTerm to EOF */

  163847.   Fts3MultiSegReader *pCsr       /* Cursor object to populate */

  163848. ){

  163849.   assert( iIndex>=0 && iIndex<p->nIndex );

  163850.   assert( iLevel==FTS3_SEGCURSOR_ALL

  163851.       ||  iLevel==FTS3_SEGCURSOR_PENDING 

  163852.       ||  iLevel>=0

  163853.   );

  163854.   assert( iLevel<FTS3_SEGDIR_MAXLEVEL );

  163855.   assert( FTS3_SEGCURSOR_ALL<0 && FTS3_SEGCURSOR_PENDING<0 );

  163856.   assert( isPrefix==0 || isScan==0 );

  163857. 

  163858.   memset(pCsr, 0, sizeof(Fts3MultiSegReader));

  163859.   return fts3SegReaderCursor(

  163860.       p, iLangid, iIndex, iLevel, zTerm, nTerm, isPrefix, isScan, pCsr

  163861.   );

  163862. }

  163863. 

  163864. /*

  163865. ** In addition to its current configuration, have the Fts3MultiSegReader

  163866. ** passed as the 4th argument also scan the doclist for term zTerm/nTerm.

  163867. **

  163868. ** SQLITE_OK is returned if no error occurs, otherwise an SQLite error code.

  163869. */

  163870. static int fts3SegReaderCursorAddZero(

  163871.   Fts3Table *p,                   /* FTS virtual table handle */

  163872.   int iLangid,

  163873.   const char *zTerm,              /* Term to scan doclist of */

  163874.   int nTerm,                      /* Number of bytes in zTerm */

  163875.   Fts3MultiSegReader *pCsr        /* Fts3MultiSegReader to modify */

  163876. ){

  163877.   return fts3SegReaderCursor(p, 

  163878.       iLangid, 0, FTS3_SEGCURSOR_ALL, zTerm, nTerm, 0, 0,pCsr

  163879.   );

  163880. }

  163881. 

  163882. /*

  163883. ** Open an Fts3MultiSegReader to scan the doclist for term zTerm/nTerm. Or,

  163884. ** if isPrefix is true, to scan the doclist for all terms for which 

  163885. ** zTerm/nTerm is a prefix. If successful, return SQLITE_OK and write

  163886. ** a pointer to the new Fts3MultiSegReader to *ppSegcsr. Otherwise, return

  163887. ** an SQLite error code.

  163888. **

  163889. ** It is the responsibility of the caller to free this object by eventually

  163890. ** passing it to fts3SegReaderCursorFree() 

  163891. **

  163892. ** SQLITE_OK is returned if no error occurs, otherwise an SQLite error code.

  163893. ** Output parameter *ppSegcsr is set to 0 if an error occurs.

  163894. */

  163895. static int fts3TermSegReaderCursor(

  163896.   Fts3Cursor *pCsr,               /* Virtual table cursor handle */

  163897.   const char *zTerm,              /* Term to query for */

  163898.   int nTerm,                      /* Size of zTerm in bytes */

  163899.   int isPrefix,                   /* True for a prefix search */

  163900.   Fts3MultiSegReader **ppSegcsr   /* OUT: Allocated seg-reader cursor */

  163901. ){

  163902.   Fts3MultiSegReader *pSegcsr;    /* Object to allocate and return */

  163903.   int rc = SQLITE_NOMEM;          /* Return code */

  163904. 

  163905.   pSegcsr = sqlite3_malloc(sizeof(Fts3MultiSegReader));

  163906.   if( pSegcsr ){

  163907.     int i;

  163908.     int bFound = 0;               /* True once an index has been found */

  163909.     Fts3Table *p = (Fts3Table *)pCsr->base.pVtab;

  163910. 

  163911.     if( isPrefix ){

  163912.       for(i=1; bFound==0 && i<p->nIndex; i++){

  163913.         if( p->aIndex[i].nPrefix==nTerm ){

  163914.           bFound = 1;

  163915.           rc = sqlite3Fts3SegReaderCursor(p, pCsr->iLangid, 

  163916.               i, FTS3_SEGCURSOR_ALL, zTerm, nTerm, 0, 0, pSegcsr

  163917.           );

  163918.           pSegcsr->bLookup = 1;

  163919.         }

  163920.       }

  163921. 

  163922.       for(i=1; bFound==0 && i<p->nIndex; i++){

  163923.         if( p->aIndex[i].nPrefix==nTerm+1 ){

  163924.           bFound = 1;

  163925.           rc = sqlite3Fts3SegReaderCursor(p, pCsr->iLangid, 

  163926.               i, FTS3_SEGCURSOR_ALL, zTerm, nTerm, 1, 0, pSegcsr

  163927.           );

  163928.           if( rc==SQLITE_OK ){

  163929.             rc = fts3SegReaderCursorAddZero(

  163930.                 p, pCsr->iLangid, zTerm, nTerm, pSegcsr

  163931.             );

  163932.           }

  163933.         }

  163934.       }

  163935.     }

  163936. 

  163937.     if( bFound==0 ){

  163938.       rc = sqlite3Fts3SegReaderCursor(p, pCsr->iLangid, 

  163939.           0, FTS3_SEGCURSOR_ALL, zTerm, nTerm, isPrefix, 0, pSegcsr

  163940.       );

  163941.       pSegcsr->bLookup = !isPrefix;

  163942.     }

  163943.   }

  163944. 

  163945.   *ppSegcsr = pSegcsr;

  163946.   return rc;

  163947. }

  163948. 

  163949. /*

  163950. ** Free an Fts3MultiSegReader allocated by fts3TermSegReaderCursor().

  163951. */

  163952. static void fts3SegReaderCursorFree(Fts3MultiSegReader *pSegcsr){

  163953.   sqlite3Fts3SegReaderFinish(pSegcsr);

  163954.   sqlite3_free(pSegcsr);

  163955. }

  163956. 

  163957. /*

  163958. ** This function retrieves the doclist for the specified term (or term

  163959. ** prefix) from the database.

  163960. */

  163961. static int fts3TermSelect(

  163962.   Fts3Table *p,                   /* Virtual table handle */

  163963.   Fts3PhraseToken *pTok,          /* Token to query for */

  163964.   int iColumn,                    /* Column to query (or -ve for all columns) */

  163965.   int *pnOut,                     /* OUT: Size of buffer at *ppOut */

  163966.   char **ppOut                    /* OUT: Malloced result buffer */

  163967. ){

  163968.   int rc;                         /* Return code */

  163969.   Fts3MultiSegReader *pSegcsr;    /* Seg-reader cursor for this term */

  163970.   TermSelect tsc;                 /* Object for pair-wise doclist merging */

  163971.   Fts3SegFilter filter;           /* Segment term filter configuration */

  163972. 

  163973.   pSegcsr = pTok->pSegcsr;

  163974.   memset(&tsc, 0, sizeof(TermSelect));

  163975. 

  163976.   filter.flags = FTS3_SEGMENT_IGNORE_EMPTY | FTS3_SEGMENT_REQUIRE_POS

  163977.         | (pTok->isPrefix ? FTS3_SEGMENT_PREFIX : 0)

  163978.         | (pTok->bFirst ? FTS3_SEGMENT_FIRST : 0)

  163979.         | (iColumn<p->nColumn ? FTS3_SEGMENT_COLUMN_FILTER : 0);

  163980.   filter.iCol = iColumn;

  163981.   filter.zTerm = pTok->z;

  163982.   filter.nTerm = pTok->n;

  163983. 

  163984.   rc = sqlite3Fts3SegReaderStart(p, pSegcsr, &filter);

  163985.   while( SQLITE_OK==rc

  163986.       && SQLITE_ROW==(rc = sqlite3Fts3SegReaderStep(p, pSegcsr)) 

  163987.   ){

  163988.     rc = fts3TermSelectMerge(p, &tsc, pSegcsr->aDoclist, pSegcsr->nDoclist);

  163989.   }

  163990. 

  163991.   if( rc==SQLITE_OK ){

  163992.     rc = fts3TermSelectFinishMerge(p, &tsc);

  163993.   }

  163994.   if( rc==SQLITE_OK ){

  163995.     *ppOut = tsc.aaOutput[0];

  163996.     *pnOut = tsc.anOutput[0];

  163997.   }else{

  163998.     int i;

  163999.     for(i=0; i<SizeofArray(tsc.aaOutput); i++){

  164000.       sqlite3_free(tsc.aaOutput[i]);

  164001.     }

  164002.   }

  164003. 

  164004.   fts3SegReaderCursorFree(pSegcsr);

  164005.   pTok->pSegcsr = 0;

  164006.   return rc;

  164007. }

  164008. 

  164009. /*

  164010. ** This function counts the total number of docids in the doclist stored

  164011. ** in buffer aList[], size nList bytes.

  164012. **

  164013. ** If the isPoslist argument is true, then it is assumed that the doclist

  164014. ** contains a position-list following each docid. Otherwise, it is assumed

  164015. ** that the doclist is simply a list of docids stored as delta encoded 

  164016. ** varints.

  164017. */

  164018. static int fts3DoclistCountDocids(char *aList, int nList){

  164019.   int nDoc = 0;                   /* Return value */

  164020.   if( aList ){

  164021.     char *aEnd = &aList[nList];   /* Pointer to one byte after EOF */

  164022.     char *p = aList;              /* Cursor */

  164023.     while( p<aEnd ){

  164024.       nDoc++;

  164025.       while( (*p++)&0x80 );     /* Skip docid varint */

  164026.       fts3PoslistCopy(0, &p);   /* Skip over position list */

  164027.     }

  164028.   }

  164029. 

  164030.   return nDoc;

  164031. }

  164032. 

  164033. /*

  164034. ** Advance the cursor to the next row in the %_content table that

  164035. ** matches the search criteria.  For a MATCH search, this will be

  164036. ** the next row that matches. For a full-table scan, this will be

  164037. ** simply the next row in the %_content table.  For a docid lookup,

  164038. ** this routine simply sets the EOF flag.

  164039. **

  164040. ** Return SQLITE_OK if nothing goes wrong.  SQLITE_OK is returned

  164041. ** even if we reach end-of-file.  The fts3EofMethod() will be called

  164042. ** subsequently to determine whether or not an EOF was hit.

  164043. */

  164044. static int fts3NextMethod(sqlite3_vtab_cursor *pCursor){

  164045.   int rc;

  164046.   Fts3Cursor *pCsr = (Fts3Cursor *)pCursor;

  164047.   if( pCsr->eSearch==FTS3_DOCID_SEARCH || pCsr->eSearch==FTS3_FULLSCAN_SEARCH ){

  164048.     if( SQLITE_ROW!=sqlite3_step(pCsr->pStmt) ){

  164049.       pCsr->isEof = 1;

  164050.       rc = sqlite3_reset(pCsr->pStmt);

  164051.     }else{

  164052.       pCsr->iPrevId = sqlite3_column_int64(pCsr->pStmt, 0);

  164053.       rc = SQLITE_OK;

  164054.     }

  164055.   }else{

  164056.     rc = fts3EvalNext((Fts3Cursor *)pCursor);

  164057.   }

  164058.   assert( ((Fts3Table *)pCsr->base.pVtab)->pSegments==0 );

  164059.   return rc;

  164060. }

  164061. 

  164062. /*

  164063. ** The following are copied from sqliteInt.h.

  164064. **

  164065. ** Constants for the largest and smallest possible 64-bit signed integers.

  164066. ** These macros are designed to work correctly on both 32-bit and 64-bit

  164067. ** compilers.

  164068. */

  164069. #ifndef SQLITE_AMALGAMATION

  164070. # define LARGEST_INT64  (0xffffffff|(((sqlite3_int64)0x7fffffff)<<32))

  164071. # define SMALLEST_INT64 (((sqlite3_int64)-1) - LARGEST_INT64)

  164072. #endif

  164073. 

  164074. /*

  164075. ** If the numeric type of argument pVal is "integer", then return it

  164076. ** converted to a 64-bit signed integer. Otherwise, return a copy of

  164077. ** the second parameter, iDefault.

  164078. */

  164079. static sqlite3_int64 fts3DocidRange(sqlite3_value *pVal, i64 iDefault){

  164080.   if( pVal ){

  164081.     int eType = sqlite3_value_numeric_type(pVal);

  164082.     if( eType==SQLITE_INTEGER ){

  164083.       return sqlite3_value_int64(pVal);

  164084.     }

  164085.   }

  164086.   return iDefault;

  164087. }

  164088. 

  164089. /*

  164090. ** This is the xFilter interface for the virtual table.  See

  164091. ** the virtual table xFilter method documentation for additional

  164092. ** information.

  164093. **

  164094. ** If idxNum==FTS3_FULLSCAN_SEARCH then do a full table scan against

  164095. ** the %_content table.

  164096. **

  164097. ** If idxNum==FTS3_DOCID_SEARCH then do a docid lookup for a single entry

  164098. ** in the %_content table.

  164099. **

  164100. ** If idxNum>=FTS3_FULLTEXT_SEARCH then use the full text index.  The

  164101. ** column on the left-hand side of the MATCH operator is column

  164102. ** number idxNum-FTS3_FULLTEXT_SEARCH, 0 indexed.  argv[0] is the right-hand

  164103. ** side of the MATCH operator.

  164104. */

  164105. static int fts3FilterMethod(

  164106.   sqlite3_vtab_cursor *pCursor,   /* The cursor used for this query */

  164107.   int idxNum,                     /* Strategy index */

  164108.   const char *idxStr,             /* Unused */

  164109.   int nVal,                       /* Number of elements in apVal */

  164110.   sqlite3_value **apVal           /* Arguments for the indexing scheme */

  164111. ){

  164112.   int rc = SQLITE_OK;

  164113.   char *zSql;                     /* SQL statement used to access %_content */

  164114.   int eSearch;

  164115.   Fts3Table *p = (Fts3Table *)pCursor->pVtab;

  164116.   Fts3Cursor *pCsr = (Fts3Cursor *)pCursor;

  164117. 

  164118.   sqlite3_value *pCons = 0;       /* The MATCH or rowid constraint, if any */

  164119.   sqlite3_value *pLangid = 0;     /* The "langid = ?" constraint, if any */

  164120.   sqlite3_value *pDocidGe = 0;    /* The "docid >= ?" constraint, if any */

  164121.   sqlite3_value *pDocidLe = 0;    /* The "docid <= ?" constraint, if any */

  164122.   int iIdx;

  164123. 

  164124.   UNUSED_PARAMETER(idxStr);

  164125.   UNUSED_PARAMETER(nVal);

  164126. 

  164127.   eSearch = (idxNum & 0x0000FFFF);

  164128.   assert( eSearch>=0 && eSearch<=(FTS3_FULLTEXT_SEARCH+p->nColumn) );

  164129.   assert( p->pSegments==0 );

  164130. 

  164131.   /* Collect arguments into local variables */

  164132.   iIdx = 0;

  164133.   if( eSearch!=FTS3_FULLSCAN_SEARCH ) pCons = apVal[iIdx++];

  164134.   if( idxNum & FTS3_HAVE_LANGID ) pLangid = apVal[iIdx++];

  164135.   if( idxNum & FTS3_HAVE_DOCID_GE ) pDocidGe = apVal[iIdx++];

  164136.   if( idxNum & FTS3_HAVE_DOCID_LE ) pDocidLe = apVal[iIdx++];

  164137.   assert( iIdx==nVal );

  164138. 

  164139.   /* In case the cursor has been used before, clear it now. */

  164140.   fts3ClearCursor(pCsr);

  164141. 

  164142.   /* Set the lower and upper bounds on docids to return */

  164143.   pCsr->iMinDocid = fts3DocidRange(pDocidGe, SMALLEST_INT64);

  164144.   pCsr->iMaxDocid = fts3DocidRange(pDocidLe, LARGEST_INT64);

  164145. 

  164146.   if( idxStr ){

  164147.     pCsr->bDesc = (idxStr[0]=='D');

  164148.   }else{

  164149.     pCsr->bDesc = p->bDescIdx;

  164150.   }

  164151.   pCsr->eSearch = (i16)eSearch;

  164152. 

  164153.   if( eSearch!=FTS3_DOCID_SEARCH && eSearch!=FTS3_FULLSCAN_SEARCH ){

  164154.     int iCol = eSearch-FTS3_FULLTEXT_SEARCH;

  164155.     const char *zQuery = (const char *)sqlite3_value_text(pCons);

  164156. 

  164157.     if( zQuery==0 && sqlite3_value_type(pCons)!=SQLITE_NULL ){

  164158.       return SQLITE_NOMEM;

  164159.     }

  164160. 

  164161.     pCsr->iLangid = 0;

  164162.     if( pLangid ) pCsr->iLangid = sqlite3_value_int(pLangid);

  164163. 

  164164.     assert( p->base.zErrMsg==0 );

  164165.     rc = sqlite3Fts3ExprParse(p->pTokenizer, pCsr->iLangid,

  164166.         p->azColumn, p->bFts4, p->nColumn, iCol, zQuery, -1, &pCsr->pExpr, 

  164167.         &p->base.zErrMsg

  164168.     );

  164169.     if( rc!=SQLITE_OK ){

  164170.       return rc;

  164171.     }

  164172. 

  164173.     rc = fts3EvalStart(pCsr);

  164174.     sqlite3Fts3SegmentsClose(p);

  164175.     if( rc!=SQLITE_OK ) return rc;

  164176.     pCsr->pNextId = pCsr->aDoclist;

  164177.     pCsr->iPrevId = 0;

  164178.   }

  164179. 

  164180.   /* Compile a SELECT statement for this cursor. For a full-table-scan, the

  164181.   ** statement loops through all rows of the %_content table. For a

  164182.   ** full-text query or docid lookup, the statement retrieves a single

  164183.   ** row by docid.

  164184.   */

  164185.   if( eSearch==FTS3_FULLSCAN_SEARCH ){

  164186.     if( pDocidGe || pDocidLe ){

  164187.       zSql = sqlite3_mprintf(

  164188.           "SELECT %s WHERE rowid BETWEEN %lld AND %lld ORDER BY rowid %s",

  164189.           p->zReadExprlist, pCsr->iMinDocid, pCsr->iMaxDocid,

  164190.           (pCsr->bDesc ? "DESC" : "ASC")

  164191.       );

  164192.     }else{

  164193.       zSql = sqlite3_mprintf("SELECT %s ORDER BY rowid %s", 

  164194.           p->zReadExprlist, (pCsr->bDesc ? "DESC" : "ASC")

  164195.       );

  164196.     }

  164197.     if( zSql ){

  164198.       rc = sqlite3_prepare_v3(p->db,zSql,-1,SQLITE_PREPARE_PERSISTENT,&pCsr->pStmt,0);

  164199.       sqlite3_free(zSql);

  164200.     }else{

  164201.       rc = SQLITE_NOMEM;

  164202.     }

  164203.   }else if( eSearch==FTS3_DOCID_SEARCH ){

  164204.     rc = fts3CursorSeekStmt(pCsr);

  164205.     if( rc==SQLITE_OK ){

  164206.       rc = sqlite3_bind_value(pCsr->pStmt, 1, pCons);

  164207.     }

  164208.   }

  164209.   if( rc!=SQLITE_OK ) return rc;

  164210. 

  164211.   return fts3NextMethod(pCursor);

  164212. }

  164213. 

  164214. /* 

  164215. ** This is the xEof method of the virtual table. SQLite calls this 

  164216. ** routine to find out if it has reached the end of a result set.

  164217. */

  164218. static int fts3EofMethod(sqlite3_vtab_cursor *pCursor){

  164219.   Fts3Cursor *pCsr = (Fts3Cursor*)pCursor;

  164220.   if( pCsr->isEof ){

  164221.     fts3ClearCursor(pCsr);

  164222.     pCsr->isEof = 1;

  164223.   }

  164224.   return pCsr->isEof;

  164225. }

  164226. 

  164227. /* 

  164228. ** This is the xRowid method. The SQLite core calls this routine to

  164229. ** retrieve the rowid for the current row of the result set. fts3

  164230. ** exposes %_content.docid as the rowid for the virtual table. The

  164231. ** rowid should be written to *pRowid.

  164232. */

  164233. static int fts3RowidMethod(sqlite3_vtab_cursor *pCursor, sqlite_int64 *pRowid){

  164234.   Fts3Cursor *pCsr = (Fts3Cursor *) pCursor;

  164235.   *pRowid = pCsr->iPrevId;

  164236.   return SQLITE_OK;

  164237. }

  164238. 

  164239. /* 

  164240. ** This is the xColumn method, called by SQLite to request a value from

  164241. ** the row that the supplied cursor currently points to.

  164242. **

  164243. ** If:

  164244. **

  164245. **   (iCol <  p->nColumn)   -> The value of the iCol'th user column.

  164246. **   (iCol == p->nColumn)   -> Magic column with the same name as the table.

  164247. **   (iCol == p->nColumn+1) -> Docid column

  164248. **   (iCol == p->nColumn+2) -> Langid column

  164249. */

  164250. static int fts3ColumnMethod(

  164251.   sqlite3_vtab_cursor *pCursor,   /* Cursor to retrieve value from */

  164252.   sqlite3_context *pCtx,          /* Context for sqlite3_result_xxx() calls */

  164253.   int iCol                        /* Index of column to read value from */

  164254. ){

  164255.   int rc = SQLITE_OK;             /* Return Code */

  164256.   Fts3Cursor *pCsr = (Fts3Cursor *) pCursor;

  164257.   Fts3Table *p = (Fts3Table *)pCursor->pVtab;

  164258. 

  164259.   /* The column value supplied by SQLite must be in range. */

  164260.   assert( iCol>=0 && iCol<=p->nColumn+2 );

  164261. 

  164262.   switch( iCol-p->nColumn ){

  164263.     case 0:

  164264.       /* The special 'table-name' column */

  164265.       sqlite3_result_pointer(pCtx, pCsr, "fts3cursor", 0);

  164266.       break;

  164267. 

  164268.     case 1:

  164269.       /* The docid column */

  164270.       sqlite3_result_int64(pCtx, pCsr->iPrevId);

  164271.       break;

  164272. 

  164273.     case 2:

  164274.       if( pCsr->pExpr ){

  164275.         sqlite3_result_int64(pCtx, pCsr->iLangid);

  164276.         break;

  164277.       }else if( p->zLanguageid==0 ){

  164278.         sqlite3_result_int(pCtx, 0);

  164279.         break;

  164280.       }else{

  164281.         iCol = p->nColumn;

  164282.         /* fall-through */

  164283.       }

  164284. 

  164285.     default:

  164286.       /* A user column. Or, if this is a full-table scan, possibly the

  164287.       ** language-id column. Seek the cursor. */

  164288.       rc = fts3CursorSeek(0, pCsr);

  164289.       if( rc==SQLITE_OK && sqlite3_data_count(pCsr->pStmt)-1>iCol ){

  164290.         sqlite3_result_value(pCtx, sqlite3_column_value(pCsr->pStmt, iCol+1));

  164291.       }

  164292.       break;

  164293.   }

  164294. 

  164295.   assert( ((Fts3Table *)pCsr->base.pVtab)->pSegments==0 );

  164296.   return rc;

  164297. }

  164298. 

  164299. /* 

  164300. ** This function is the implementation of the xUpdate callback used by 

  164301. ** FTS3 virtual tables. It is invoked by SQLite each time a row is to be

  164302. ** inserted, updated or deleted.

  164303. */

  164304. static int fts3UpdateMethod(

  164305.   sqlite3_vtab *pVtab,            /* Virtual table handle */

  164306.   int nArg,                       /* Size of argument array */

  164307.   sqlite3_value **apVal,          /* Array of arguments */

  164308.   sqlite_int64 *pRowid            /* OUT: The affected (or effected) rowid */

  164309. ){

  164310.   return sqlite3Fts3UpdateMethod(pVtab, nArg, apVal, pRowid);

  164311. }

  164312. 

  164313. /*

  164314. ** Implementation of xSync() method. Flush the contents of the pending-terms

  164315. ** hash-table to the database.

  164316. */

  164317. static int fts3SyncMethod(sqlite3_vtab *pVtab){

  164318. 

  164319.   /* Following an incremental-merge operation, assuming that the input

  164320.   ** segments are not completely consumed (the usual case), they are updated

  164321.   ** in place to remove the entries that have already been merged. This

  164322.   ** involves updating the leaf block that contains the smallest unmerged

  164323.   ** entry and each block (if any) between the leaf and the root node. So

  164324.   ** if the height of the input segment b-trees is N, and input segments

  164325.   ** are merged eight at a time, updating the input segments at the end

  164326.   ** of an incremental-merge requires writing (8*(1+N)) blocks. N is usually

  164327.   ** small - often between 0 and 2. So the overhead of the incremental

  164328.   ** merge is somewhere between 8 and 24 blocks. To avoid this overhead

  164329.   ** dwarfing the actual productive work accomplished, the incremental merge

  164330.   ** is only attempted if it will write at least 64 leaf blocks. Hence

  164331.   ** nMinMerge.

  164332.   **

  164333.   ** Of course, updating the input segments also involves deleting a bunch

  164334.   ** of blocks from the segments table. But this is not considered overhead

  164335.   ** as it would also be required by a crisis-merge that used the same input 

  164336.   ** segments.

  164337.   */

  164338.   const u32 nMinMerge = 64;       /* Minimum amount of incr-merge work to do */

  164339. 

  164340.   Fts3Table *p = (Fts3Table*)pVtab;

  164341.   int rc;

  164342.   i64 iLastRowid = sqlite3_last_insert_rowid(p->db);

  164343. 

  164344.   rc = sqlite3Fts3PendingTermsFlush(p);

  164345.   if( rc==SQLITE_OK 

  164346.    && p->nLeafAdd>(nMinMerge/16) 

  164347.    && p->nAutoincrmerge && p->nAutoincrmerge!=0xff

  164348.   ){

  164349.     int mxLevel = 0;              /* Maximum relative level value in db */

  164350.     int A;                        /* Incr-merge parameter A */

  164351. 

  164352.     rc = sqlite3Fts3MaxLevel(p, &mxLevel);

  164353.     assert( rc==SQLITE_OK || mxLevel==0 );

  164354.     A = p->nLeafAdd * mxLevel;

  164355.     A += (A/2);

  164356.     if( A>(int)nMinMerge ) rc = sqlite3Fts3Incrmerge(p, A, p->nAutoincrmerge);

  164357.   }

  164358.   sqlite3Fts3SegmentsClose(p);

  164359.   sqlite3_set_last_insert_rowid(p->db, iLastRowid);

  164360.   return rc;

  164361. }

  164362. 

  164363. /*

  164364. ** If it is currently unknown whether or not the FTS table has an %_stat

  164365. ** table (if p->bHasStat==2), attempt to determine this (set p->bHasStat

  164366. ** to 0 or 1). Return SQLITE_OK if successful, or an SQLite error code

  164367. ** if an error occurs.

  164368. */

  164369. static int fts3SetHasStat(Fts3Table *p){

  164370.   int rc = SQLITE_OK;

  164371.   if( p->bHasStat==2 ){

  164372.     char *zTbl = sqlite3_mprintf("%s_stat", p->zName);

  164373.     if( zTbl ){

  164374.       int res = sqlite3_table_column_metadata(p->db, p->zDb, zTbl, 0,0,0,0,0,0);

  164375.       sqlite3_free(zTbl);

  164376.       p->bHasStat = (res==SQLITE_OK);

  164377.     }else{

  164378.       rc = SQLITE_NOMEM;

  164379.     }

  164380.   }

  164381.   return rc;

  164382. }

  164383. 

  164384. /*

  164385. ** Implementation of xBegin() method. 

  164386. */

  164387. static int fts3BeginMethod(sqlite3_vtab *pVtab){

  164388.   Fts3Table *p = (Fts3Table*)pVtab;

  164389.   UNUSED_PARAMETER(pVtab);

  164390.   assert( p->pSegments==0 );

  164391.   assert( p->nPendingData==0 );

  164392.   assert( p->inTransaction!=1 );

  164393.   TESTONLY( p->inTransaction = 1 );

  164394.   TESTONLY( p->mxSavepoint = -1; );

  164395.   p->nLeafAdd = 0;

  164396.   return fts3SetHasStat(p);

  164397. }

  164398. 

  164399. /*

  164400. ** Implementation of xCommit() method. This is a no-op. The contents of

  164401. ** the pending-terms hash-table have already been flushed into the database

  164402. ** by fts3SyncMethod().

  164403. */

  164404. static int fts3CommitMethod(sqlite3_vtab *pVtab){

  164405.   TESTONLY( Fts3Table *p = (Fts3Table*)pVtab );

  164406.   UNUSED_PARAMETER(pVtab);

  164407.   assert( p->nPendingData==0 );

  164408.   assert( p->inTransaction!=0 );

  164409.   assert( p->pSegments==0 );

  164410.   TESTONLY( p->inTransaction = 0 );

  164411.   TESTONLY( p->mxSavepoint = -1; );

  164412.   return SQLITE_OK;

  164413. }

  164414. 

  164415. /*

  164416. ** Implementation of xRollback(). Discard the contents of the pending-terms

  164417. ** hash-table. Any changes made to the database are reverted by SQLite.

  164418. */

  164419. static int fts3RollbackMethod(sqlite3_vtab *pVtab){

  164420.   Fts3Table *p = (Fts3Table*)pVtab;

  164421.   sqlite3Fts3PendingTermsClear(p);

  164422.   assert( p->inTransaction!=0 );

  164423.   TESTONLY( p->inTransaction = 0 );

  164424.   TESTONLY( p->mxSavepoint = -1; );

  164425.   return SQLITE_OK;

  164426. }

  164427. 

  164428. /*

  164429. ** When called, *ppPoslist must point to the byte immediately following the

  164430. ** end of a position-list. i.e. ( (*ppPoslist)[-1]==POS_END ). This function

  164431. ** moves *ppPoslist so that it instead points to the first byte of the

  164432. ** same position list.

  164433. */

  164434. static void fts3ReversePoslist(char *pStart, char **ppPoslist){

  164435.   char *p = &(*ppPoslist)[-2];

  164436.   char c = 0;

  164437. 

  164438.   /* Skip backwards passed any trailing 0x00 bytes added by NearTrim() */

  164439.   while( p>pStart && (c=*p--)==0 );

  164440. 

  164441.   /* Search backwards for a varint with value zero (the end of the previous 

  164442.   ** poslist). This is an 0x00 byte preceded by some byte that does not

  164443.   ** have the 0x80 bit set.  */

  164444.   while( p>pStart && (*p & 0x80) | c ){ 

  164445.     c = *p--; 

  164446.   }

  164447.   assert( p==pStart || c==0 );

  164448. 

  164449.   /* At this point p points to that preceding byte without the 0x80 bit

  164450.   ** set. So to find the start of the poslist, skip forward 2 bytes then

  164451.   ** over a varint. 

  164452.   **

  164453.   ** Normally. The other case is that p==pStart and the poslist to return

  164454.   ** is the first in the doclist. In this case do not skip forward 2 bytes.

  164455.   ** The second part of the if condition (c==0 && *ppPoslist>&p[2])

  164456.   ** is required for cases where the first byte of a doclist and the

  164457.   ** doclist is empty. For example, if the first docid is 10, a doclist

  164458.   ** that begins with:

  164459.   **

  164460.   **   0x0A 0x00 <next docid delta varint>

  164461.   */

  164462.   if( p>pStart || (c==0 && *ppPoslist>&p[2]) ){ p = &p[2]; }

  164463.   while( *p++&0x80 );

  164464.   *ppPoslist = p;

  164465. }

  164466. 

  164467. /*

  164468. ** Helper function used by the implementation of the overloaded snippet(),

  164469. ** offsets() and optimize() SQL functions.

  164470. **

  164471. ** If the value passed as the third argument is a blob of size

  164472. ** sizeof(Fts3Cursor*), then the blob contents are copied to the 

  164473. ** output variable *ppCsr and SQLITE_OK is returned. Otherwise, an error

  164474. ** message is written to context pContext and SQLITE_ERROR returned. The

  164475. ** string passed via zFunc is used as part of the error message.

  164476. */

  164477. static int fts3FunctionArg(

  164478.   sqlite3_context *pContext,      /* SQL function call context */

  164479.   const char *zFunc,              /* Function name */

  164480.   sqlite3_value *pVal,            /* argv[0] passed to function */

  164481.   Fts3Cursor **ppCsr              /* OUT: Store cursor handle here */

  164482. ){

  164483.   int rc;

  164484.   *ppCsr = (Fts3Cursor*)sqlite3_value_pointer(pVal, "fts3cursor");

  164485.   if( (*ppCsr)!=0 ){

  164486.     rc = SQLITE_OK;

  164487.   }else{

  164488.     char *zErr = sqlite3_mprintf("illegal first argument to %s", zFunc);

  164489.     sqlite3_result_error(pContext, zErr, -1);

  164490.     sqlite3_free(zErr);

  164491.     rc = SQLITE_ERROR;

  164492.   }

  164493.   return rc;

  164494. }

  164495. 

  164496. /*

  164497. ** Implementation of the snippet() function for FTS3

  164498. */

  164499. static void fts3SnippetFunc(

  164500.   sqlite3_context *pContext,      /* SQLite function call context */

  164501.   int nVal,                       /* Size of apVal[] array */

  164502.   sqlite3_value **apVal           /* Array of arguments */

  164503. ){

  164504.   Fts3Cursor *pCsr;               /* Cursor handle passed through apVal[0] */

  164505.   const char *zStart = "<b>";

  164506.   const char *zEnd = "</b>";

  164507.   const char *zEllipsis = "<b>...</b>";

  164508.   int iCol = -1;

  164509.   int nToken = 15;                /* Default number of tokens in snippet */

  164510. 

  164511.   /* There must be at least one argument passed to this function (otherwise

  164512.   ** the non-overloaded version would have been called instead of this one).

  164513.   */

  164514.   assert( nVal>=1 );

  164515. 

  164516.   if( nVal>6 ){

  164517.     sqlite3_result_error(pContext, 

  164518.         "wrong number of arguments to function snippet()", -1);

  164519.     return;

  164520.   }

  164521.   if( fts3FunctionArg(pContext, "snippet", apVal[0], &pCsr) ) return;

  164522. 

  164523.   switch( nVal ){

  164524.     case 6: nToken = sqlite3_value_int(apVal[5]);

  164525.     case 5: iCol = sqlite3_value_int(apVal[4]);

  164526.     case 4: zEllipsis = (const char*)sqlite3_value_text(apVal[3]);

  164527.     case 3: zEnd = (const char*)sqlite3_value_text(apVal[2]);

  164528.     case 2: zStart = (const char*)sqlite3_value_text(apVal[1]);

  164529.   }

  164530.   if( !zEllipsis || !zEnd || !zStart ){

  164531.     sqlite3_result_error_nomem(pContext);

  164532.   }else if( nToken==0 ){

  164533.     sqlite3_result_text(pContext, "", -1, SQLITE_STATIC);

  164534.   }else if( SQLITE_OK==fts3CursorSeek(pContext, pCsr) ){

  164535.     sqlite3Fts3Snippet(pContext, pCsr, zStart, zEnd, zEllipsis, iCol, nToken);

  164536.   }

  164537. }

  164538. 

  164539. /*

  164540. ** Implementation of the offsets() function for FTS3

  164541. */

  164542. static void fts3OffsetsFunc(

  164543.   sqlite3_context *pContext,      /* SQLite function call context */

  164544.   int nVal,                       /* Size of argument array */

  164545.   sqlite3_value **apVal           /* Array of arguments */

  164546. ){

  164547.   Fts3Cursor *pCsr;               /* Cursor handle passed through apVal[0] */

  164548. 

  164549.   UNUSED_PARAMETER(nVal);

  164550. 

  164551.   assert( nVal==1 );

  164552.   if( fts3FunctionArg(pContext, "offsets", apVal[0], &pCsr) ) return;

  164553.   assert( pCsr );

  164554.   if( SQLITE_OK==fts3CursorSeek(pContext, pCsr) ){

  164555.     sqlite3Fts3Offsets(pContext, pCsr);

  164556.   }

  164557. }

  164558. 

  164559. /* 

  164560. ** Implementation of the special optimize() function for FTS3. This 

  164561. ** function merges all segments in the database to a single segment.

  164562. ** Example usage is:

  164563. **

  164564. **   SELECT optimize(t) FROM t LIMIT 1;

  164565. **

  164566. ** where 't' is the name of an FTS3 table.

  164567. */

  164568. static void fts3OptimizeFunc(

  164569.   sqlite3_context *pContext,      /* SQLite function call context */

  164570.   int nVal,                       /* Size of argument array */

  164571.   sqlite3_value **apVal           /* Array of arguments */

  164572. ){

  164573.   int rc;                         /* Return code */

  164574.   Fts3Table *p;                   /* Virtual table handle */

  164575.   Fts3Cursor *pCursor;            /* Cursor handle passed through apVal[0] */

  164576. 

  164577.   UNUSED_PARAMETER(nVal);

  164578. 

  164579.   assert( nVal==1 );

  164580.   if( fts3FunctionArg(pContext, "optimize", apVal[0], &pCursor) ) return;

  164581.   p = (Fts3Table *)pCursor->base.pVtab;

  164582.   assert( p );

  164583. 

  164584.   rc = sqlite3Fts3Optimize(p);

  164585. 

  164586.   switch( rc ){

  164587.     case SQLITE_OK:

  164588.       sqlite3_result_text(pContext, "Index optimized", -1, SQLITE_STATIC);

  164589.       break;

  164590.     case SQLITE_DONE:

  164591.       sqlite3_result_text(pContext, "Index already optimal", -1, SQLITE_STATIC);

  164592.       break;

  164593.     default:

  164594.       sqlite3_result_error_code(pContext, rc);

  164595.       break;

  164596.   }

  164597. }

  164598. 

  164599. /*

  164600. ** Implementation of the matchinfo() function for FTS3

  164601. */

  164602. static void fts3MatchinfoFunc(

  164603.   sqlite3_context *pContext,      /* SQLite function call context */

  164604.   int nVal,                       /* Size of argument array */

  164605.   sqlite3_value **apVal           /* Array of arguments */

  164606. ){

  164607.   Fts3Cursor *pCsr;               /* Cursor handle passed through apVal[0] */

  164608.   assert( nVal==1 || nVal==2 );

  164609.   if( SQLITE_OK==fts3FunctionArg(pContext, "matchinfo", apVal[0], &pCsr) ){

  164610.     const char *zArg = 0;

  164611.     if( nVal>1 ){

  164612.       zArg = (const char *)sqlite3_value_text(apVal[1]);

  164613.     }

  164614.     sqlite3Fts3Matchinfo(pContext, pCsr, zArg);

  164615.   }

  164616. }

  164617. 

  164618. /*

  164619. ** This routine implements the xFindFunction method for the FTS3

  164620. ** virtual table.

  164621. */

  164622. static int fts3FindFunctionMethod(

  164623.   sqlite3_vtab *pVtab,            /* Virtual table handle */

  164624.   int nArg,                       /* Number of SQL function arguments */

  164625.   const char *zName,              /* Name of SQL function */

  164626.   void (**pxFunc)(sqlite3_context*,int,sqlite3_value**), /* OUT: Result */

  164627.   void **ppArg                    /* Unused */

  164628. ){

  164629.   struct Overloaded {

  164630.     const char *zName;

  164631.     void (*xFunc)(sqlite3_context*,int,sqlite3_value**);

  164632.   } aOverload[] = {

  164633.     { "snippet", fts3SnippetFunc },

  164634.     { "offsets", fts3OffsetsFunc },

  164635.     { "optimize", fts3OptimizeFunc },

  164636.     { "matchinfo", fts3MatchinfoFunc },

  164637.   };

  164638.   int i;                          /* Iterator variable */

  164639. 

  164640.   UNUSED_PARAMETER(pVtab);

  164641.   UNUSED_PARAMETER(nArg);

  164642.   UNUSED_PARAMETER(ppArg);

  164643. 

  164644.   for(i=0; i<SizeofArray(aOverload); i++){

  164645.     if( strcmp(zName, aOverload[i].zName)==0 ){

  164646.       *pxFunc = aOverload[i].xFunc;

  164647.       return 1;

  164648.     }

  164649.   }

  164650. 

  164651.   /* No function of the specified name was found. Return 0. */

  164652.   return 0;

  164653. }

  164654. 

  164655. /*

  164656. ** Implementation of FTS3 xRename method. Rename an fts3 table.

  164657. */

  164658. static int fts3RenameMethod(

  164659.   sqlite3_vtab *pVtab,            /* Virtual table handle */

  164660.   const char *zName               /* New name of table */

  164661. ){

  164662.   Fts3Table *p = (Fts3Table *)pVtab;

  164663.   sqlite3 *db = p->db;            /* Database connection */

  164664.   int rc;                         /* Return Code */

  164665. 

  164666.   /* At this point it must be known if the %_stat table exists or not.

  164667.   ** So bHasStat may not be 2.  */

  164668.   rc = fts3SetHasStat(p);

  164669.   

  164670.   /* As it happens, the pending terms table is always empty here. This is

  164671.   ** because an "ALTER TABLE RENAME TABLE" statement inside a transaction 

  164672.   ** always opens a savepoint transaction. And the xSavepoint() method 

  164673.   ** flushes the pending terms table. But leave the (no-op) call to

  164674.   ** PendingTermsFlush() in in case that changes.

  164675.   */

  164676.   assert( p->nPendingData==0 );

  164677.   if( rc==SQLITE_OK ){

  164678.     rc = sqlite3Fts3PendingTermsFlush(p);

  164679.   }

  164680. 

  164681.   if( p->zContentTbl==0 ){

  164682.     fts3DbExec(&rc, db,

  164683.       "ALTER TABLE %Q.'%q_content'  RENAME TO '%q_content';",

  164684.       p->zDb, p->zName, zName

  164685.     );

  164686.   }

  164687. 

  164688.   if( p->bHasDocsize ){

  164689.     fts3DbExec(&rc, db,

  164690.       "ALTER TABLE %Q.'%q_docsize'  RENAME TO '%q_docsize';",

  164691.       p->zDb, p->zName, zName

  164692.     );

  164693.   }

  164694.   if( p->bHasStat ){

  164695.     fts3DbExec(&rc, db,

  164696.       "ALTER TABLE %Q.'%q_stat'  RENAME TO '%q_stat';",

  164697.       p->zDb, p->zName, zName

  164698.     );

  164699.   }

  164700.   fts3DbExec(&rc, db,

  164701.     "ALTER TABLE %Q.'%q_segments' RENAME TO '%q_segments';",

  164702.     p->zDb, p->zName, zName

  164703.   );

  164704.   fts3DbExec(&rc, db,

  164705.     "ALTER TABLE %Q.'%q_segdir'   RENAME TO '%q_segdir';",

  164706.     p->zDb, p->zName, zName

  164707.   );

  164708.   return rc;

  164709. }

  164710. 

  164711. /*

  164712. ** The xSavepoint() method.

  164713. **

  164714. ** Flush the contents of the pending-terms table to disk.

  164715. */

  164716. static int fts3SavepointMethod(sqlite3_vtab *pVtab, int iSavepoint){

  164717.   int rc = SQLITE_OK;

  164718.   UNUSED_PARAMETER(iSavepoint);

  164719.   assert( ((Fts3Table *)pVtab)->inTransaction );

  164720.   assert( ((Fts3Table *)pVtab)->mxSavepoint <= iSavepoint );

  164721.   TESTONLY( ((Fts3Table *)pVtab)->mxSavepoint = iSavepoint );

  164722.   if( ((Fts3Table *)pVtab)->bIgnoreSavepoint==0 ){

  164723.     rc = fts3SyncMethod(pVtab);

  164724.   }

  164725.   return rc;

  164726. }

  164727. 

  164728. /*

  164729. ** The xRelease() method.

  164730. **

  164731. ** This is a no-op.

  164732. */

  164733. static int fts3ReleaseMethod(sqlite3_vtab *pVtab, int iSavepoint){

  164734.   TESTONLY( Fts3Table *p = (Fts3Table*)pVtab );

  164735.   UNUSED_PARAMETER(iSavepoint);

  164736.   UNUSED_PARAMETER(pVtab);

  164737.   assert( p->inTransaction );

  164738.   assert( p->mxSavepoint >= iSavepoint );

  164739.   TESTONLY( p->mxSavepoint = iSavepoint-1 );

  164740.   return SQLITE_OK;

  164741. }

  164742. 

  164743. /*

  164744. ** The xRollbackTo() method.

  164745. **

  164746. ** Discard the contents of the pending terms table.

  164747. */

  164748. static int fts3RollbackToMethod(sqlite3_vtab *pVtab, int iSavepoint){

  164749.   Fts3Table *p = (Fts3Table*)pVtab;

  164750.   UNUSED_PARAMETER(iSavepoint);

  164751.   assert( p->inTransaction );

  164752.   TESTONLY( p->mxSavepoint = iSavepoint );

  164753.   sqlite3Fts3PendingTermsClear(p);

  164754.   return SQLITE_OK;

  164755. }

  164756. 

  164757. /*

  164758. ** Return true if zName is the extension on one of the shadow tables used

  164759. ** by this module.

  164760. */

  164761. static int fts3ShadowName(const char *zName){

  164762.   static const char *azName[] = {

  164763.     "content", "docsize", "segdir", "segments", "stat", 

  164764.   };

  164765.   unsigned int i;

  164766.   for(i=0; i<sizeof(azName)/sizeof(azName[0]); i++){

  164767.     if( sqlite3_stricmp(zName, azName[i])==0 ) return 1;

  164768.   }

  164769.   return 0;

  164770. }

  164771. 

  164772. static const sqlite3_module fts3Module = {

  164773.   /* iVersion      */ 3,

  164774.   /* xCreate       */ fts3CreateMethod,

  164775.   /* xConnect      */ fts3ConnectMethod,

  164776.   /* xBestIndex    */ fts3BestIndexMethod,

  164777.   /* xDisconnect   */ fts3DisconnectMethod,

  164778.   /* xDestroy      */ fts3DestroyMethod,

  164779.   /* xOpen         */ fts3OpenMethod,

  164780.   /* xClose        */ fts3CloseMethod,

  164781.   /* xFilter       */ fts3FilterMethod,

  164782.   /* xNext         */ fts3NextMethod,

  164783.   /* xEof          */ fts3EofMethod,

  164784.   /* xColumn       */ fts3ColumnMethod,

  164785.   /* xRowid        */ fts3RowidMethod,

  164786.   /* xUpdate       */ fts3UpdateMethod,

  164787.   /* xBegin        */ fts3BeginMethod,

  164788.   /* xSync         */ fts3SyncMethod,

  164789.   /* xCommit       */ fts3CommitMethod,

  164790.   /* xRollback     */ fts3RollbackMethod,

  164791.   /* xFindFunction */ fts3FindFunctionMethod,

  164792.   /* xRename */       fts3RenameMethod,

  164793.   /* xSavepoint    */ fts3SavepointMethod,

  164794.   /* xRelease      */ fts3ReleaseMethod,

  164795.   /* xRollbackTo   */ fts3RollbackToMethod,

  164796.   /* xShadowName   */ fts3ShadowName,

  164797. };

  164798. 

  164799. /*

  164800. ** This function is registered as the module destructor (called when an

  164801. ** FTS3 enabled database connection is closed). It frees the memory

  164802. ** allocated for the tokenizer hash table.

  164803. */

  164804. static void hashDestroy(void *p){

  164805.   Fts3Hash *pHash = (Fts3Hash *)p;

  164806.   sqlite3Fts3HashClear(pHash);

  164807.   sqlite3_free(pHash);

  164808. }

  164809. 

  164810. /*

  164811. ** The fts3 built-in tokenizers - "simple", "porter" and "icu"- are 

  164812. ** implemented in files fts3_tokenizer1.c, fts3_porter.c and fts3_icu.c

  164813. ** respectively. The following three forward declarations are for functions

  164814. ** declared in these files used to retrieve the respective implementations.

  164815. **

  164816. ** Calling sqlite3Fts3SimpleTokenizerModule() sets the value pointed

  164817. ** to by the argument to point to the "simple" tokenizer implementation.

  164818. ** And so on.

  164819. */

  164820. SQLITE_PRIVATE void sqlite3Fts3SimpleTokenizerModule(sqlite3_tokenizer_module const**ppModule);

  164821. SQLITE_PRIVATE void sqlite3Fts3PorterTokenizerModule(sqlite3_tokenizer_module const**ppModule);

  164822. #ifndef SQLITE_DISABLE_FTS3_UNICODE

  164823. SQLITE_PRIVATE void sqlite3Fts3UnicodeTokenizer(sqlite3_tokenizer_module const**ppModule);

  164824. #endif

  164825. #ifdef SQLITE_ENABLE_ICU

  164826. SQLITE_PRIVATE void sqlite3Fts3IcuTokenizerModule(sqlite3_tokenizer_module const**ppModule);

  164827. #endif

  164828. 

  164829. /*

  164830. ** Initialize the fts3 extension. If this extension is built as part

  164831. ** of the sqlite library, then this function is called directly by

  164832. ** SQLite. If fts3 is built as a dynamically loadable extension, this

  164833. ** function is called by the sqlite3_extension_init() entry point.

  164834. */

  164835. SQLITE_PRIVATE int sqlite3Fts3Init(sqlite3 *db){

  164836.   int rc = SQLITE_OK;

  164837.   Fts3Hash *pHash = 0;

  164838.   const sqlite3_tokenizer_module *pSimple = 0;

  164839.   const sqlite3_tokenizer_module *pPorter = 0;

  164840. #ifndef SQLITE_DISABLE_FTS3_UNICODE

  164841.   const sqlite3_tokenizer_module *pUnicode = 0;

  164842. #endif

  164843. 

  164844. #ifdef SQLITE_ENABLE_ICU

  164845.   const sqlite3_tokenizer_module *pIcu = 0;

  164846.   sqlite3Fts3IcuTokenizerModule(&pIcu);

  164847. #endif

  164848. 

  164849. #ifndef SQLITE_DISABLE_FTS3_UNICODE

  164850.   sqlite3Fts3UnicodeTokenizer(&pUnicode);

  164851. #endif

  164852. 

  164853. #ifdef SQLITE_TEST

  164854.   rc = sqlite3Fts3InitTerm(db);

  164855.   if( rc!=SQLITE_OK ) return rc;

  164856. #endif

  164857. 

  164858.   rc = sqlite3Fts3InitAux(db);

  164859.   if( rc!=SQLITE_OK ) return rc;

  164860. 

  164861.   sqlite3Fts3SimpleTokenizerModule(&pSimple);

  164862.   sqlite3Fts3PorterTokenizerModule(&pPorter);

  164863. 

  164864.   /* Allocate and initialize the hash-table used to store tokenizers. */

  164865.   pHash = sqlite3_malloc(sizeof(Fts3Hash));

  164866.   if( !pHash ){

  164867.     rc = SQLITE_NOMEM;

  164868.   }else{

  164869.     sqlite3Fts3HashInit(pHash, FTS3_HASH_STRING, 1);

  164870.   }

  164871. 

  164872.   /* Load the built-in tokenizers into the hash table */

  164873.   if( rc==SQLITE_OK ){

  164874.     if( sqlite3Fts3HashInsert(pHash, "simple", 7, (void *)pSimple)

  164875.      || sqlite3Fts3HashInsert(pHash, "porter", 7, (void *)pPorter) 

  164876. 

  164877. #ifndef SQLITE_DISABLE_FTS3_UNICODE

  164878.      || sqlite3Fts3HashInsert(pHash, "unicode61", 10, (void *)pUnicode) 

  164879. #endif

  164880. #ifdef SQLITE_ENABLE_ICU

  164881.      || (pIcu && sqlite3Fts3HashInsert(pHash, "icu", 4, (void *)pIcu))

  164882. #endif

  164883.     ){

  164884.       rc = SQLITE_NOMEM;

  164885.     }

  164886.   }

  164887. 

  164888. #ifdef SQLITE_TEST

  164889.   if( rc==SQLITE_OK ){

  164890.     rc = sqlite3Fts3ExprInitTestInterface(db, pHash);

  164891.   }

  164892. #endif

  164893. 

  164894.   /* Create the virtual table wrapper around the hash-table and overload 

  164895.   ** the four scalar functions. If this is successful, register the

  164896.   ** module with sqlite.

  164897.   */

  164898.   if( SQLITE_OK==rc 

  164899.    && SQLITE_OK==(rc = sqlite3Fts3InitHashTable(db, pHash, "fts3_tokenizer"))

  164900.    && SQLITE_OK==(rc = sqlite3_overload_function(db, "snippet", -1))

  164901.    && SQLITE_OK==(rc = sqlite3_overload_function(db, "offsets", 1))

  164902.    && SQLITE_OK==(rc = sqlite3_overload_function(db, "matchinfo", 1))

  164903.    && SQLITE_OK==(rc = sqlite3_overload_function(db, "matchinfo", 2))

  164904.    && SQLITE_OK==(rc = sqlite3_overload_function(db, "optimize", 1))

  164905.   ){

  164906.     rc = sqlite3_create_module_v2(

  164907.         db, "fts3", &fts3Module, (void *)pHash, hashDestroy

  164908.     );

  164909.     if( rc==SQLITE_OK ){

  164910.       rc = sqlite3_create_module_v2(

  164911.           db, "fts4", &fts3Module, (void *)pHash, 0

  164912.       );

  164913.     }

  164914.     if( rc==SQLITE_OK ){

  164915.       rc = sqlite3Fts3InitTok(db, (void *)pHash);

  164916.     }

  164917.     return rc;

  164918.   }

  164919. 

  164920. 

  164921.   /* An error has occurred. Delete the hash table and return the error code. */

  164922.   assert( rc!=SQLITE_OK );

  164923.   if( pHash ){

  164924.     sqlite3Fts3HashClear(pHash);

  164925.     sqlite3_free(pHash);

  164926.   }

  164927.   return rc;

  164928. }

  164929. 

  164930. /*

  164931. ** Allocate an Fts3MultiSegReader for each token in the expression headed

  164932. ** by pExpr. 

  164933. **

  164934. ** An Fts3SegReader object is a cursor that can seek or scan a range of

  164935. ** entries within a single segment b-tree. An Fts3MultiSegReader uses multiple

  164936. ** Fts3SegReader objects internally to provide an interface to seek or scan

  164937. ** within the union of all segments of a b-tree. Hence the name.

  164938. **

  164939. ** If the allocated Fts3MultiSegReader just seeks to a single entry in a

  164940. ** segment b-tree (if the term is not a prefix or it is a prefix for which

  164941. ** there exists prefix b-tree of the right length) then it may be traversed

  164942. ** and merged incrementally. Otherwise, it has to be merged into an in-memory 

  164943. ** doclist and then traversed.

  164944. */

  164945. static void fts3EvalAllocateReaders(

  164946.   Fts3Cursor *pCsr,               /* FTS cursor handle */

  164947.   Fts3Expr *pExpr,                /* Allocate readers for this expression */

  164948.   int *pnToken,                   /* OUT: Total number of tokens in phrase. */

  164949.   int *pnOr,                      /* OUT: Total number of OR nodes in expr. */

  164950.   int *pRc                        /* IN/OUT: Error code */

  164951. ){

  164952.   if( pExpr && SQLITE_OK==*pRc ){

  164953.     if( pExpr->eType==FTSQUERY_PHRASE ){

  164954.       int i;

  164955.       int nToken = pExpr->pPhrase->nToken;

  164956.       *pnToken += nToken;

  164957.       for(i=0; i<nToken; i++){

  164958.         Fts3PhraseToken *pToken = &pExpr->pPhrase->aToken[i];

  164959.         int rc = fts3TermSegReaderCursor(pCsr, 

  164960.             pToken->z, pToken->n, pToken->isPrefix, &pToken->pSegcsr

  164961.         );

  164962.         if( rc!=SQLITE_OK ){

  164963.           *pRc = rc;

  164964.           return;

  164965.         }

  164966.       }

  164967.       assert( pExpr->pPhrase->iDoclistToken==0 );

  164968.       pExpr->pPhrase->iDoclistToken = -1;

  164969.     }else{

  164970.       *pnOr += (pExpr->eType==FTSQUERY_OR);

  164971.       fts3EvalAllocateReaders(pCsr, pExpr->pLeft, pnToken, pnOr, pRc);

  164972.       fts3EvalAllocateReaders(pCsr, pExpr->pRight, pnToken, pnOr, pRc);

  164973.     }

  164974.   }

  164975. }

  164976. 

  164977. /*

  164978. ** Arguments pList/nList contain the doclist for token iToken of phrase p.

  164979. ** It is merged into the main doclist stored in p->doclist.aAll/nAll.

  164980. **

  164981. ** This function assumes that pList points to a buffer allocated using

  164982. ** sqlite3_malloc(). This function takes responsibility for eventually

  164983. ** freeing the buffer.

  164984. **

  164985. ** SQLITE_OK is returned if successful, or SQLITE_NOMEM if an error occurs.

  164986. */

  164987. static int fts3EvalPhraseMergeToken(

  164988.   Fts3Table *pTab,                /* FTS Table pointer */

  164989.   Fts3Phrase *p,                  /* Phrase to merge pList/nList into */

  164990.   int iToken,                     /* Token pList/nList corresponds to */

  164991.   char *pList,                    /* Pointer to doclist */

  164992.   int nList                       /* Number of bytes in pList */

  164993. ){

  164994.   int rc = SQLITE_OK;

  164995.   assert( iToken!=p->iDoclistToken );

  164996. 

  164997.   if( pList==0 ){

  164998.     sqlite3_free(p->doclist.aAll);

  164999.     p->doclist.aAll = 0;

  165000.     p->doclist.nAll = 0;

  165001.   }

  165002. 

  165003.   else if( p->iDoclistToken<0 ){

  165004.     p->doclist.aAll = pList;

  165005.     p->doclist.nAll = nList;

  165006.   }

  165007. 

  165008.   else if( p->doclist.aAll==0 ){

  165009.     sqlite3_free(pList);

  165010.   }

  165011. 

  165012.   else {

  165013.     char *pLeft;

  165014.     char *pRight;

  165015.     int nLeft;

  165016.     int nRight;

  165017.     int nDiff;

  165018. 

  165019.     if( p->iDoclistToken<iToken ){

  165020.       pLeft = p->doclist.aAll;

  165021.       nLeft = p->doclist.nAll;

  165022.       pRight = pList;

  165023.       nRight = nList;

  165024.       nDiff = iToken - p->iDoclistToken;

  165025.     }else{

  165026.       pRight = p->doclist.aAll;

  165027.       nRight = p->doclist.nAll;

  165028.       pLeft = pList;

  165029.       nLeft = nList;

  165030.       nDiff = p->iDoclistToken - iToken;

  165031.     }

  165032. 

  165033.     rc = fts3DoclistPhraseMerge(

  165034.         pTab->bDescIdx, nDiff, pLeft, nLeft, &pRight, &nRight

  165035.     );

  165036.     sqlite3_free(pLeft);

  165037.     p->doclist.aAll = pRight;

  165038.     p->doclist.nAll = nRight;

  165039.   }

  165040. 

  165041.   if( iToken>p->iDoclistToken ) p->iDoclistToken = iToken;

  165042.   return rc;

  165043. }

  165044. 

  165045. /*

  165046. ** Load the doclist for phrase p into p->doclist.aAll/nAll. The loaded doclist

  165047. ** does not take deferred tokens into account.

  165048. **

  165049. ** SQLITE_OK is returned if no error occurs, otherwise an SQLite error code.

  165050. */

  165051. static int fts3EvalPhraseLoad(

  165052.   Fts3Cursor *pCsr,               /* FTS Cursor handle */

  165053.   Fts3Phrase *p                   /* Phrase object */

  165054. ){

  165055.   Fts3Table *pTab = (Fts3Table *)pCsr->base.pVtab;

  165056.   int iToken;

  165057.   int rc = SQLITE_OK;

  165058. 

  165059.   for(iToken=0; rc==SQLITE_OK && iToken<p->nToken; iToken++){

  165060.     Fts3PhraseToken *pToken = &p->aToken[iToken];

  165061.     assert( pToken->pDeferred==0 || pToken->pSegcsr==0 );

  165062. 

  165063.     if( pToken->pSegcsr ){

  165064.       int nThis = 0;

  165065.       char *pThis = 0;

  165066.       rc = fts3TermSelect(pTab, pToken, p->iColumn, &nThis, &pThis);

  165067.       if( rc==SQLITE_OK ){

  165068.         rc = fts3EvalPhraseMergeToken(pTab, p, iToken, pThis, nThis);

  165069.       }

  165070.     }

  165071.     assert( pToken->pSegcsr==0 );

  165072.   }

  165073. 

  165074.   return rc;

  165075. }

  165076. 

  165077. #ifndef SQLITE_DISABLE_FTS4_DEFERRED

  165078. /*

  165079. ** This function is called on each phrase after the position lists for

  165080. ** any deferred tokens have been loaded into memory. It updates the phrases

  165081. ** current position list to include only those positions that are really

  165082. ** instances of the phrase (after considering deferred tokens). If this

  165083. ** means that the phrase does not appear in the current row, doclist.pList

  165084. ** and doclist.nList are both zeroed.

  165085. **

  165086. ** SQLITE_OK is returned if no error occurs, otherwise an SQLite error code.

  165087. */

  165088. static int fts3EvalDeferredPhrase(Fts3Cursor *pCsr, Fts3Phrase *pPhrase){

  165089.   int iToken;                     /* Used to iterate through phrase tokens */

  165090.   char *aPoslist = 0;             /* Position list for deferred tokens */

  165091.   int nPoslist = 0;               /* Number of bytes in aPoslist */

  165092.   int iPrev = -1;                 /* Token number of previous deferred token */

  165093. 

  165094.   assert( pPhrase->doclist.bFreeList==0 );

  165095. 

  165096.   for(iToken=0; iToken<pPhrase->nToken; iToken++){

  165097.     Fts3PhraseToken *pToken = &pPhrase->aToken[iToken];

  165098.     Fts3DeferredToken *pDeferred = pToken->pDeferred;

  165099. 

  165100.     if( pDeferred ){

  165101.       char *pList;

  165102.       int nList;

  165103.       int rc = sqlite3Fts3DeferredTokenList(pDeferred, &pList, &nList);

  165104.       if( rc!=SQLITE_OK ) return rc;

  165105. 

  165106.       if( pList==0 ){

  165107.         sqlite3_free(aPoslist);

  165108.         pPhrase->doclist.pList = 0;

  165109.         pPhrase->doclist.nList = 0;

  165110.         return SQLITE_OK;

  165111. 

  165112.       }else if( aPoslist==0 ){

  165113.         aPoslist = pList;

  165114.         nPoslist = nList;

  165115. 

  165116.       }else{

  165117.         char *aOut = pList;

  165118.         char *p1 = aPoslist;

  165119.         char *p2 = aOut;

  165120. 

  165121.         assert( iPrev>=0 );

  165122.         fts3PoslistPhraseMerge(&aOut, iToken-iPrev, 0, 1, &p1, &p2);

  165123.         sqlite3_free(aPoslist);

  165124.         aPoslist = pList;

  165125.         nPoslist = (int)(aOut - aPoslist);

  165126.         if( nPoslist==0 ){

  165127.           sqlite3_free(aPoslist);

  165128.           pPhrase->doclist.pList = 0;

  165129.           pPhrase->doclist.nList = 0;

  165130.           return SQLITE_OK;

  165131.         }

  165132.       }

  165133.       iPrev = iToken;

  165134.     }

  165135.   }

  165136. 

  165137.   if( iPrev>=0 ){

  165138.     int nMaxUndeferred = pPhrase->iDoclistToken;

  165139.     if( nMaxUndeferred<0 ){

  165140.       pPhrase->doclist.pList = aPoslist;

  165141.       pPhrase->doclist.nList = nPoslist;

  165142.       pPhrase->doclist.iDocid = pCsr->iPrevId;

  165143.       pPhrase->doclist.bFreeList = 1;

  165144.     }else{

  165145.       int nDistance;

  165146.       char *p1;

  165147.       char *p2;

  165148.       char *aOut;

  165149. 

  165150.       if( nMaxUndeferred>iPrev ){

  165151.         p1 = aPoslist;

  165152.         p2 = pPhrase->doclist.pList;

  165153.         nDistance = nMaxUndeferred - iPrev;

  165154.       }else{

  165155.         p1 = pPhrase->doclist.pList;

  165156.         p2 = aPoslist;

  165157.         nDistance = iPrev - nMaxUndeferred;

  165158.       }

  165159. 

  165160.       aOut = (char *)sqlite3_malloc(nPoslist+8);

  165161.       if( !aOut ){

  165162.         sqlite3_free(aPoslist);

  165163.         return SQLITE_NOMEM;

  165164.       }

  165165.       

  165166.       pPhrase->doclist.pList = aOut;

  165167.       if( fts3PoslistPhraseMerge(&aOut, nDistance, 0, 1, &p1, &p2) ){

  165168.         pPhrase->doclist.bFreeList = 1;

  165169.         pPhrase->doclist.nList = (int)(aOut - pPhrase->doclist.pList);

  165170.       }else{

  165171.         sqlite3_free(aOut);

  165172.         pPhrase->doclist.pList = 0;

  165173.         pPhrase->doclist.nList = 0;

  165174.       }

  165175.       sqlite3_free(aPoslist);

  165176.     }

  165177.   }

  165178. 

  165179.   return SQLITE_OK;

  165180. }

  165181. #endif /* SQLITE_DISABLE_FTS4_DEFERRED */

  165182. 

  165183. /*

  165184. ** Maximum number of tokens a phrase may have to be considered for the

  165185. ** incremental doclists strategy.

  165186. */

  165187. #define MAX_INCR_PHRASE_TOKENS 4

  165188. 

  165189. /*

  165190. ** This function is called for each Fts3Phrase in a full-text query 

  165191. ** expression to initialize the mechanism for returning rows. Once this

  165192. ** function has been called successfully on an Fts3Phrase, it may be

  165193. ** used with fts3EvalPhraseNext() to iterate through the matching docids.

  165194. **

  165195. ** If parameter bOptOk is true, then the phrase may (or may not) use the

  165196. ** incremental loading strategy. Otherwise, the entire doclist is loaded into

  165197. ** memory within this call.

  165198. **

  165199. ** SQLITE_OK is returned if no error occurs, otherwise an SQLite error code.

  165200. */

  165201. static int fts3EvalPhraseStart(Fts3Cursor *pCsr, int bOptOk, Fts3Phrase *p){

  165202.   Fts3Table *pTab = (Fts3Table *)pCsr->base.pVtab;

  165203.   int rc = SQLITE_OK;             /* Error code */

  165204.   int i;

  165205. 

  165206.   /* Determine if doclists may be loaded from disk incrementally. This is

  165207.   ** possible if the bOptOk argument is true, the FTS doclists will be

  165208.   ** scanned in forward order, and the phrase consists of 

  165209.   ** MAX_INCR_PHRASE_TOKENS or fewer tokens, none of which are are "^first"

  165210.   ** tokens or prefix tokens that cannot use a prefix-index.  */

  165211.   int bHaveIncr = 0;

  165212.   int bIncrOk = (bOptOk 

  165213.    && pCsr->bDesc==pTab->bDescIdx 

  165214.    && p->nToken<=MAX_INCR_PHRASE_TOKENS && p->nToken>0

  165215. #ifdef SQLITE_TEST

  165216.    && pTab->bNoIncrDoclist==0

  165217. #endif

  165218.   );

  165219.   for(i=0; bIncrOk==1 && i<p->nToken; i++){

  165220.     Fts3PhraseToken *pToken = &p->aToken[i];

  165221.     if( pToken->bFirst || (pToken->pSegcsr!=0 && !pToken->pSegcsr->bLookup) ){

  165222.       bIncrOk = 0;

  165223.     }

  165224.     if( pToken->pSegcsr ) bHaveIncr = 1;

  165225.   }

  165226. 

  165227.   if( bIncrOk && bHaveIncr ){

  165228.     /* Use the incremental approach. */

  165229.     int iCol = (p->iColumn >= pTab->nColumn ? -1 : p->iColumn);

  165230.     for(i=0; rc==SQLITE_OK && i<p->nToken; i++){

  165231.       Fts3PhraseToken *pToken = &p->aToken[i];

  165232.       Fts3MultiSegReader *pSegcsr = pToken->pSegcsr;

  165233.       if( pSegcsr ){

  165234.         rc = sqlite3Fts3MsrIncrStart(pTab, pSegcsr, iCol, pToken->z, pToken->n);

  165235.       }

  165236.     }

  165237.     p->bIncr = 1;

  165238.   }else{

  165239.     /* Load the full doclist for the phrase into memory. */

  165240.     rc = fts3EvalPhraseLoad(pCsr, p);

  165241.     p->bIncr = 0;

  165242.   }

  165243. 

  165244.   assert( rc!=SQLITE_OK || p->nToken<1 || p->aToken[0].pSegcsr==0 || p->bIncr );

  165245.   return rc;

  165246. }

  165247. 

  165248. /*

  165249. ** This function is used to iterate backwards (from the end to start) 

  165250. ** through doclists. It is used by this module to iterate through phrase

  165251. ** doclists in reverse and by the fts3_write.c module to iterate through

  165252. ** pending-terms lists when writing to databases with "order=desc".

  165253. **

  165254. ** The doclist may be sorted in ascending (parameter bDescIdx==0) or 

  165255. ** descending (parameter bDescIdx==1) order of docid. Regardless, this

  165256. ** function iterates from the end of the doclist to the beginning.

  165257. */

  165258. SQLITE_PRIVATE void sqlite3Fts3DoclistPrev(

  165259.   int bDescIdx,                   /* True if the doclist is desc */

  165260.   char *aDoclist,                 /* Pointer to entire doclist */

  165261.   int nDoclist,                   /* Length of aDoclist in bytes */

  165262.   char **ppIter,                  /* IN/OUT: Iterator pointer */

  165263.   sqlite3_int64 *piDocid,         /* IN/OUT: Docid pointer */

  165264.   int *pnList,                    /* OUT: List length pointer */

  165265.   u8 *pbEof                       /* OUT: End-of-file flag */

  165266. ){

  165267.   char *p = *ppIter;

  165268. 

  165269.   assert( nDoclist>0 );

  165270.   assert( *pbEof==0 );

  165271.   assert( p || *piDocid==0 );

  165272.   assert( !p || (p>aDoclist && p<&aDoclist[nDoclist]) );

  165273. 

  165274.   if( p==0 ){

  165275.     sqlite3_int64 iDocid = 0;

  165276.     char *pNext = 0;

  165277.     char *pDocid = aDoclist;

  165278.     char *pEnd = &aDoclist[nDoclist];

  165279.     int iMul = 1;

  165280. 

  165281.     while( pDocid<pEnd ){

  165282.       sqlite3_int64 iDelta;

  165283.       pDocid += sqlite3Fts3GetVarint(pDocid, &iDelta);

  165284.       iDocid += (iMul * iDelta);

  165285.       pNext = pDocid;

  165286.       fts3PoslistCopy(0, &pDocid);

  165287.       while( pDocid<pEnd && *pDocid==0 ) pDocid++;

  165288.       iMul = (bDescIdx ? -1 : 1);

  165289.     }

  165290. 

  165291.     *pnList = (int)(pEnd - pNext);

  165292.     *ppIter = pNext;

  165293.     *piDocid = iDocid;

  165294.   }else{

  165295.     int iMul = (bDescIdx ? -1 : 1);

  165296.     sqlite3_int64 iDelta;

  165297.     fts3GetReverseVarint(&p, aDoclist, &iDelta);

  165298.     *piDocid -= (iMul * iDelta);

  165299. 

  165300.     if( p==aDoclist ){

  165301.       *pbEof = 1;

  165302.     }else{

  165303.       char *pSave = p;

  165304.       fts3ReversePoslist(aDoclist, &p);

  165305.       *pnList = (int)(pSave - p);

  165306.     }

  165307.     *ppIter = p;

  165308.   }

  165309. }

  165310. 

  165311. /*

  165312. ** Iterate forwards through a doclist.

  165313. */

  165314. SQLITE_PRIVATE void sqlite3Fts3DoclistNext(

  165315.   int bDescIdx,                   /* True if the doclist is desc */

  165316.   char *aDoclist,                 /* Pointer to entire doclist */

  165317.   int nDoclist,                   /* Length of aDoclist in bytes */

  165318.   char **ppIter,                  /* IN/OUT: Iterator pointer */

  165319.   sqlite3_int64 *piDocid,         /* IN/OUT: Docid pointer */

  165320.   u8 *pbEof                       /* OUT: End-of-file flag */

  165321. ){

  165322.   char *p = *ppIter;

  165323. 

  165324.   assert( nDoclist>0 );

  165325.   assert( *pbEof==0 );

  165326.   assert( p || *piDocid==0 );

  165327.   assert( !p || (p>=aDoclist && p<=&aDoclist[nDoclist]) );

  165328. 

  165329.   if( p==0 ){

  165330.     p = aDoclist;

  165331.     p += sqlite3Fts3GetVarint(p, piDocid);

  165332.   }else{

  165333.     fts3PoslistCopy(0, &p);

  165334.     while( p<&aDoclist[nDoclist] && *p==0 ) p++; 

  165335.     if( p>=&aDoclist[nDoclist] ){

  165336.       *pbEof = 1;

  165337.     }else{

  165338.       sqlite3_int64 iVar;

  165339.       p += sqlite3Fts3GetVarint(p, &iVar);

  165340.       *piDocid += ((bDescIdx ? -1 : 1) * iVar);

  165341.     }

  165342.   }

  165343. 

  165344.   *ppIter = p;

  165345. }

  165346. 

  165347. /*

  165348. ** Advance the iterator pDL to the next entry in pDL->aAll/nAll. Set *pbEof

  165349. ** to true if EOF is reached.

  165350. */

  165351. static void fts3EvalDlPhraseNext(

  165352.   Fts3Table *pTab,

  165353.   Fts3Doclist *pDL,

  165354.   u8 *pbEof

  165355. ){

  165356.   char *pIter;                            /* Used to iterate through aAll */

  165357.   char *pEnd = &pDL->aAll[pDL->nAll];     /* 1 byte past end of aAll */

  165358.  

  165359.   if( pDL->pNextDocid ){

  165360.     pIter = pDL->pNextDocid;

  165361.   }else{

  165362.     pIter = pDL->aAll;

  165363.   }

  165364. 

  165365.   if( pIter>=pEnd ){

  165366.     /* We have already reached the end of this doclist. EOF. */

  165367.     *pbEof = 1;

  165368.   }else{

  165369.     sqlite3_int64 iDelta;

  165370.     pIter += sqlite3Fts3GetVarint(pIter, &iDelta);

  165371.     if( pTab->bDescIdx==0 || pDL->pNextDocid==0 ){

  165372.       pDL->iDocid += iDelta;

  165373.     }else{

  165374.       pDL->iDocid -= iDelta;

  165375.     }

  165376.     pDL->pList = pIter;

  165377.     fts3PoslistCopy(0, &pIter);

  165378.     pDL->nList = (int)(pIter - pDL->pList);

  165379. 

  165380.     /* pIter now points just past the 0x00 that terminates the position-

  165381.     ** list for document pDL->iDocid. However, if this position-list was

  165382.     ** edited in place by fts3EvalNearTrim(), then pIter may not actually

  165383.     ** point to the start of the next docid value. The following line deals

  165384.     ** with this case by advancing pIter past the zero-padding added by

  165385.     ** fts3EvalNearTrim().  */

  165386.     while( pIter<pEnd && *pIter==0 ) pIter++;

  165387. 

  165388.     pDL->pNextDocid = pIter;

  165389.     assert( pIter>=&pDL->aAll[pDL->nAll] || *pIter );

  165390.     *pbEof = 0;

  165391.   }

  165392. }

  165393. 

  165394. /*

  165395. ** Helper type used by fts3EvalIncrPhraseNext() and incrPhraseTokenNext().

  165396. */

  165397. typedef struct TokenDoclist TokenDoclist;

  165398. struct TokenDoclist {

  165399.   int bIgnore;

  165400.   sqlite3_int64 iDocid;

  165401.   char *pList;

  165402.   int nList;

  165403. };

  165404. 

  165405. /*

  165406. ** Token pToken is an incrementally loaded token that is part of a 

  165407. ** multi-token phrase. Advance it to the next matching document in the

  165408. ** database and populate output variable *p with the details of the new

  165409. ** entry. Or, if the iterator has reached EOF, set *pbEof to true.

  165410. **

  165411. ** If an error occurs, return an SQLite error code. Otherwise, return 

  165412. ** SQLITE_OK.

  165413. */

  165414. static int incrPhraseTokenNext(

  165415.   Fts3Table *pTab,                /* Virtual table handle */

  165416.   Fts3Phrase *pPhrase,            /* Phrase to advance token of */

  165417.   int iToken,                     /* Specific token to advance */

  165418.   TokenDoclist *p,                /* OUT: Docid and doclist for new entry */

  165419.   u8 *pbEof                       /* OUT: True if iterator is at EOF */

  165420. ){

  165421.   int rc = SQLITE_OK;

  165422. 

  165423.   if( pPhrase->iDoclistToken==iToken ){

  165424.     assert( p->bIgnore==0 );

  165425.     assert( pPhrase->aToken[iToken].pSegcsr==0 );

  165426.     fts3EvalDlPhraseNext(pTab, &pPhrase->doclist, pbEof);

  165427.     p->pList = pPhrase->doclist.pList;

  165428.     p->nList = pPhrase->doclist.nList;

  165429.     p->iDocid = pPhrase->doclist.iDocid;

  165430.   }else{

  165431.     Fts3PhraseToken *pToken = &pPhrase->aToken[iToken];

  165432.     assert( pToken->pDeferred==0 );

  165433.     assert( pToken->pSegcsr || pPhrase->iDoclistToken>=0 );

  165434.     if( pToken->pSegcsr ){

  165435.       assert( p->bIgnore==0 );

  165436.       rc = sqlite3Fts3MsrIncrNext(

  165437.           pTab, pToken->pSegcsr, &p->iDocid, &p->pList, &p->nList

  165438.       );

  165439.       if( p->pList==0 ) *pbEof = 1;

  165440.     }else{

  165441.       p->bIgnore = 1;

  165442.     }

  165443.   }

  165444. 

  165445.   return rc;

  165446. }

  165447. 

  165448. 

  165449. /*

  165450. ** The phrase iterator passed as the second argument:

  165451. **

  165452. **   * features at least one token that uses an incremental doclist, and 

  165453. **

  165454. **   * does not contain any deferred tokens.

  165455. **

  165456. ** Advance it to the next matching documnent in the database and populate

  165457. ** the Fts3Doclist.pList and nList fields. 

  165458. **

  165459. ** If there is no "next" entry and no error occurs, then *pbEof is set to

  165460. ** 1 before returning. Otherwise, if no error occurs and the iterator is

  165461. ** successfully advanced, *pbEof is set to 0.

  165462. **

  165463. ** If an error occurs, return an SQLite error code. Otherwise, return 

  165464. ** SQLITE_OK.

  165465. */

  165466. static int fts3EvalIncrPhraseNext(

  165467.   Fts3Cursor *pCsr,               /* FTS Cursor handle */

  165468.   Fts3Phrase *p,                  /* Phrase object to advance to next docid */

  165469.   u8 *pbEof                       /* OUT: Set to 1 if EOF */

  165470. ){

  165471.   int rc = SQLITE_OK;

  165472.   Fts3Doclist *pDL = &p->doclist;

  165473.   Fts3Table *pTab = (Fts3Table *)pCsr->base.pVtab;

  165474.   u8 bEof = 0;

  165475. 

  165476.   /* This is only called if it is guaranteed that the phrase has at least

  165477.   ** one incremental token. In which case the bIncr flag is set. */

  165478.   assert( p->bIncr==1 );

  165479. 

  165480.   if( p->nToken==1 ){

  165481.     rc = sqlite3Fts3MsrIncrNext(pTab, p->aToken[0].pSegcsr, 

  165482.         &pDL->iDocid, &pDL->pList, &pDL->nList

  165483.     );

  165484.     if( pDL->pList==0 ) bEof = 1;

  165485.   }else{

  165486.     int bDescDoclist = pCsr->bDesc;

  165487.     struct TokenDoclist a[MAX_INCR_PHRASE_TOKENS];

  165488. 

  165489.     memset(a, 0, sizeof(a));

  165490.     assert( p->nToken<=MAX_INCR_PHRASE_TOKENS );

  165491.     assert( p->iDoclistToken<MAX_INCR_PHRASE_TOKENS );

  165492. 

  165493.     while( bEof==0 ){

  165494.       int bMaxSet = 0;

  165495.       sqlite3_int64 iMax = 0;     /* Largest docid for all iterators */

  165496.       int i;                      /* Used to iterate through tokens */

  165497. 

  165498.       /* Advance the iterator for each token in the phrase once. */

  165499.       for(i=0; rc==SQLITE_OK && i<p->nToken && bEof==0; i++){

  165500.         rc = incrPhraseTokenNext(pTab, p, i, &a[i], &bEof);

  165501.         if( a[i].bIgnore==0 && (bMaxSet==0 || DOCID_CMP(iMax, a[i].iDocid)<0) ){

  165502.           iMax = a[i].iDocid;

  165503.           bMaxSet = 1;

  165504.         }

  165505.       }

  165506.       assert( rc!=SQLITE_OK || (p->nToken>=1 && a[p->nToken-1].bIgnore==0) );

  165507.       assert( rc!=SQLITE_OK || bMaxSet );

  165508. 

  165509.       /* Keep advancing iterators until they all point to the same document */

  165510.       for(i=0; i<p->nToken; i++){

  165511.         while( rc==SQLITE_OK && bEof==0 

  165512.             && a[i].bIgnore==0 && DOCID_CMP(a[i].iDocid, iMax)<0 

  165513.         ){

  165514.           rc = incrPhraseTokenNext(pTab, p, i, &a[i], &bEof);

  165515.           if( DOCID_CMP(a[i].iDocid, iMax)>0 ){

  165516.             iMax = a[i].iDocid;

  165517.             i = 0;

  165518.           }

  165519.         }

  165520.       }

  165521. 

  165522.       /* Check if the current entries really are a phrase match */

  165523.       if( bEof==0 ){

  165524.         int nList = 0;

  165525.         int nByte = a[p->nToken-1].nList;

  165526.         char *aDoclist = sqlite3_malloc(nByte+FTS3_BUFFER_PADDING);

  165527.         if( !aDoclist ) return SQLITE_NOMEM;

  165528.         memcpy(aDoclist, a[p->nToken-1].pList, nByte+1);

  165529.         memset(&aDoclist[nByte], 0, FTS3_BUFFER_PADDING);

  165530. 

  165531.         for(i=0; i<(p->nToken-1); i++){

  165532.           if( a[i].bIgnore==0 ){

  165533.             char *pL = a[i].pList;

  165534.             char *pR = aDoclist;

  165535.             char *pOut = aDoclist;

  165536.             int nDist = p->nToken-1-i;

  165537.             int res = fts3PoslistPhraseMerge(&pOut, nDist, 0, 1, &pL, &pR);

  165538.             if( res==0 ) break;

  165539.             nList = (int)(pOut - aDoclist);

  165540.           }

  165541.         }

  165542.         if( i==(p->nToken-1) ){

  165543.           pDL->iDocid = iMax;

  165544.           pDL->pList = aDoclist;

  165545.           pDL->nList = nList;

  165546.           pDL->bFreeList = 1;

  165547.           break;

  165548.         }

  165549.         sqlite3_free(aDoclist);

  165550.       }

  165551.     }

  165552.   }

  165553. 

  165554.   *pbEof = bEof;

  165555.   return rc;

  165556. }

  165557. 

  165558. /*

  165559. ** Attempt to move the phrase iterator to point to the next matching docid. 

  165560. ** If an error occurs, return an SQLite error code. Otherwise, return 

  165561. ** SQLITE_OK.

  165562. **

  165563. ** If there is no "next" entry and no error occurs, then *pbEof is set to

  165564. ** 1 before returning. Otherwise, if no error occurs and the iterator is

  165565. ** successfully advanced, *pbEof is set to 0.

  165566. */

  165567. static int fts3EvalPhraseNext(

  165568.   Fts3Cursor *pCsr,               /* FTS Cursor handle */

  165569.   Fts3Phrase *p,                  /* Phrase object to advance to next docid */

  165570.   u8 *pbEof                       /* OUT: Set to 1 if EOF */

  165571. ){

  165572.   int rc = SQLITE_OK;

  165573.   Fts3Doclist *pDL = &p->doclist;

  165574.   Fts3Table *pTab = (Fts3Table *)pCsr->base.pVtab;

  165575. 

  165576.   if( p->bIncr ){

  165577.     rc = fts3EvalIncrPhraseNext(pCsr, p, pbEof);

  165578.   }else if( pCsr->bDesc!=pTab->bDescIdx && pDL->nAll ){

  165579.     sqlite3Fts3DoclistPrev(pTab->bDescIdx, pDL->aAll, pDL->nAll, 

  165580.         &pDL->pNextDocid, &pDL->iDocid, &pDL->nList, pbEof

  165581.     );

  165582.     pDL->pList = pDL->pNextDocid;

  165583.   }else{

  165584.     fts3EvalDlPhraseNext(pTab, pDL, pbEof);

  165585.   }

  165586. 

  165587.   return rc;

  165588. }

  165589. 

  165590. /*

  165591. **

  165592. ** If *pRc is not SQLITE_OK when this function is called, it is a no-op.

  165593. ** Otherwise, fts3EvalPhraseStart() is called on all phrases within the

  165594. ** expression. Also the Fts3Expr.bDeferred variable is set to true for any

  165595. ** expressions for which all descendent tokens are deferred.

  165596. **

  165597. ** If parameter bOptOk is zero, then it is guaranteed that the

  165598. ** Fts3Phrase.doclist.aAll/nAll variables contain the entire doclist for

  165599. ** each phrase in the expression (subject to deferred token processing).

  165600. ** Or, if bOptOk is non-zero, then one or more tokens within the expression

  165601. ** may be loaded incrementally, meaning doclist.aAll/nAll is not available.

  165602. **

  165603. ** If an error occurs within this function, *pRc is set to an SQLite error

  165604. ** code before returning.

  165605. */

  165606. static void fts3EvalStartReaders(

  165607.   Fts3Cursor *pCsr,               /* FTS Cursor handle */

  165608.   Fts3Expr *pExpr,                /* Expression to initialize phrases in */

  165609.   int *pRc                        /* IN/OUT: Error code */

  165610. ){

  165611.   if( pExpr && SQLITE_OK==*pRc ){

  165612.     if( pExpr->eType==FTSQUERY_PHRASE ){

  165613.       int nToken = pExpr->pPhrase->nToken;

  165614.       if( nToken ){

  165615.         int i;

  165616.         for(i=0; i<nToken; i++){

  165617.           if( pExpr->pPhrase->aToken[i].pDeferred==0 ) break;

  165618.         }

  165619.         pExpr->bDeferred = (i==nToken);

  165620.       }

  165621.       *pRc = fts3EvalPhraseStart(pCsr, 1, pExpr->pPhrase);

  165622.     }else{

  165623.       fts3EvalStartReaders(pCsr, pExpr->pLeft, pRc);

  165624.       fts3EvalStartReaders(pCsr, pExpr->pRight, pRc);

  165625.       pExpr->bDeferred = (pExpr->pLeft->bDeferred && pExpr->pRight->bDeferred);

  165626.     }

  165627.   }

  165628. }

  165629. 

  165630. /*

  165631. ** An array of the following structures is assembled as part of the process

  165632. ** of selecting tokens to defer before the query starts executing (as part

  165633. ** of the xFilter() method). There is one element in the array for each

  165634. ** token in the FTS expression.

  165635. **

  165636. ** Tokens are divided into AND/NEAR clusters. All tokens in a cluster belong

  165637. ** to phrases that are connected only by AND and NEAR operators (not OR or

  165638. ** NOT). When determining tokens to defer, each AND/NEAR cluster is considered

  165639. ** separately. The root of a tokens AND/NEAR cluster is stored in 

  165640. ** Fts3TokenAndCost.pRoot.

  165641. */

  165642. typedef struct Fts3TokenAndCost Fts3TokenAndCost;

  165643. struct Fts3TokenAndCost {

  165644.   Fts3Phrase *pPhrase;            /* The phrase the token belongs to */

  165645.   int iToken;                     /* Position of token in phrase */

  165646.   Fts3PhraseToken *pToken;        /* The token itself */

  165647.   Fts3Expr *pRoot;                /* Root of NEAR/AND cluster */

  165648.   int nOvfl;                      /* Number of overflow pages to load doclist */

  165649.   int iCol;                       /* The column the token must match */

  165650. };

  165651. 

  165652. /*

  165653. ** This function is used to populate an allocated Fts3TokenAndCost array.

  165654. **

  165655. ** If *pRc is not SQLITE_OK when this function is called, it is a no-op.

  165656. ** Otherwise, if an error occurs during execution, *pRc is set to an

  165657. ** SQLite error code.

  165658. */

  165659. static void fts3EvalTokenCosts(

  165660.   Fts3Cursor *pCsr,               /* FTS Cursor handle */

  165661.   Fts3Expr *pRoot,                /* Root of current AND/NEAR cluster */

  165662.   Fts3Expr *pExpr,                /* Expression to consider */

  165663.   Fts3TokenAndCost **ppTC,        /* Write new entries to *(*ppTC)++ */

  165664.   Fts3Expr ***ppOr,               /* Write new OR root to *(*ppOr)++ */

  165665.   int *pRc                        /* IN/OUT: Error code */

  165666. ){

  165667.   if( *pRc==SQLITE_OK ){

  165668.     if( pExpr->eType==FTSQUERY_PHRASE ){

  165669.       Fts3Phrase *pPhrase = pExpr->pPhrase;

  165670.       int i;

  165671.       for(i=0; *pRc==SQLITE_OK && i<pPhrase->nToken; i++){

  165672.         Fts3TokenAndCost *pTC = (*ppTC)++;

  165673.         pTC->pPhrase = pPhrase;

  165674.         pTC->iToken = i;

  165675.         pTC->pRoot = pRoot;

  165676.         pTC->pToken = &pPhrase->aToken[i];

  165677.         pTC->iCol = pPhrase->iColumn;

  165678.         *pRc = sqlite3Fts3MsrOvfl(pCsr, pTC->pToken->pSegcsr, &pTC->nOvfl);

  165679.       }

  165680.     }else if( pExpr->eType!=FTSQUERY_NOT ){

  165681.       assert( pExpr->eType==FTSQUERY_OR

  165682.            || pExpr->eType==FTSQUERY_AND

  165683.            || pExpr->eType==FTSQUERY_NEAR

  165684.       );

  165685.       assert( pExpr->pLeft && pExpr->pRight );

  165686.       if( pExpr->eType==FTSQUERY_OR ){

  165687.         pRoot = pExpr->pLeft;

  165688.         **ppOr = pRoot;

  165689.         (*ppOr)++;

  165690.       }

  165691.       fts3EvalTokenCosts(pCsr, pRoot, pExpr->pLeft, ppTC, ppOr, pRc);

  165692.       if( pExpr->eType==FTSQUERY_OR ){

  165693.         pRoot = pExpr->pRight;

  165694.         **ppOr = pRoot;

  165695.         (*ppOr)++;

  165696.       }

  165697.       fts3EvalTokenCosts(pCsr, pRoot, pExpr->pRight, ppTC, ppOr, pRc);

  165698.     }

  165699.   }

  165700. }

  165701. 

  165702. /*

  165703. ** Determine the average document (row) size in pages. If successful,

  165704. ** write this value to *pnPage and return SQLITE_OK. Otherwise, return

  165705. ** an SQLite error code.

  165706. **

  165707. ** The average document size in pages is calculated by first calculating 

  165708. ** determining the average size in bytes, B. If B is less than the amount

  165709. ** of data that will fit on a single leaf page of an intkey table in

  165710. ** this database, then the average docsize is 1. Otherwise, it is 1 plus

  165711. ** the number of overflow pages consumed by a record B bytes in size.

  165712. */

  165713. static int fts3EvalAverageDocsize(Fts3Cursor *pCsr, int *pnPage){

  165714.   int rc = SQLITE_OK;

  165715.   if( pCsr->nRowAvg==0 ){

  165716.     /* The average document size, which is required to calculate the cost

  165717.     ** of each doclist, has not yet been determined. Read the required 

  165718.     ** data from the %_stat table to calculate it.

  165719.     **

  165720.     ** Entry 0 of the %_stat table is a blob containing (nCol+1) FTS3 

  165721.     ** varints, where nCol is the number of columns in the FTS3 table.

  165722.     ** The first varint is the number of documents currently stored in

  165723.     ** the table. The following nCol varints contain the total amount of

  165724.     ** data stored in all rows of each column of the table, from left

  165725.     ** to right.

  165726.     */

  165727.     Fts3Table *p = (Fts3Table*)pCsr->base.pVtab;

  165728.     sqlite3_stmt *pStmt;

  165729.     sqlite3_int64 nDoc = 0;

  165730.     sqlite3_int64 nByte = 0;

  165731.     const char *pEnd;

  165732.     const char *a;

  165733. 

  165734.     rc = sqlite3Fts3SelectDoctotal(p, &pStmt);

  165735.     if( rc!=SQLITE_OK ) return rc;

  165736.     a = sqlite3_column_blob(pStmt, 0);

  165737.     assert( a );

  165738. 

  165739.     pEnd = &a[sqlite3_column_bytes(pStmt, 0)];

  165740.     a += sqlite3Fts3GetVarint(a, &nDoc);

  165741.     while( a<pEnd ){

  165742.       a += sqlite3Fts3GetVarint(a, &nByte);

  165743.     }

  165744.     if( nDoc==0 || nByte==0 ){

  165745.       sqlite3_reset(pStmt);

  165746.       return FTS_CORRUPT_VTAB;

  165747.     }

  165748. 

  165749.     pCsr->nDoc = nDoc;

  165750.     pCsr->nRowAvg = (int)(((nByte / nDoc) + p->nPgsz) / p->nPgsz);

  165751.     assert( pCsr->nRowAvg>0 ); 

  165752.     rc = sqlite3_reset(pStmt);

  165753.   }

  165754. 

  165755.   *pnPage = pCsr->nRowAvg;

  165756.   return rc;

  165757. }

  165758. 

  165759. /*

  165760. ** This function is called to select the tokens (if any) that will be 

  165761. ** deferred. The array aTC[] has already been populated when this is

  165762. ** called.

  165763. **

  165764. ** This function is called once for each AND/NEAR cluster in the 

  165765. ** expression. Each invocation determines which tokens to defer within

  165766. ** the cluster with root node pRoot. See comments above the definition

  165767. ** of struct Fts3TokenAndCost for more details.

  165768. **

  165769. ** If no error occurs, SQLITE_OK is returned and sqlite3Fts3DeferToken()

  165770. ** called on each token to defer. Otherwise, an SQLite error code is

  165771. ** returned.

  165772. */

  165773. static int fts3EvalSelectDeferred(

  165774.   Fts3Cursor *pCsr,               /* FTS Cursor handle */

  165775.   Fts3Expr *pRoot,                /* Consider tokens with this root node */

  165776.   Fts3TokenAndCost *aTC,          /* Array of expression tokens and costs */

  165777.   int nTC                         /* Number of entries in aTC[] */

  165778. ){

  165779.   Fts3Table *pTab = (Fts3Table *)pCsr->base.pVtab;

  165780.   int nDocSize = 0;               /* Number of pages per doc loaded */

  165781.   int rc = SQLITE_OK;             /* Return code */

  165782.   int ii;                         /* Iterator variable for various purposes */

  165783.   int nOvfl = 0;                  /* Total overflow pages used by doclists */

  165784.   int nToken = 0;                 /* Total number of tokens in cluster */

  165785. 

  165786.   int nMinEst = 0;                /* The minimum count for any phrase so far. */

  165787.   int nLoad4 = 1;                 /* (Phrases that will be loaded)^4. */

  165788. 

  165789.   /* Tokens are never deferred for FTS tables created using the content=xxx

  165790.   ** option. The reason being that it is not guaranteed that the content

  165791.   ** table actually contains the same data as the index. To prevent this from

  165792.   ** causing any problems, the deferred token optimization is completely

  165793.   ** disabled for content=xxx tables. */

  165794.   if( pTab->zContentTbl ){

  165795.     return SQLITE_OK;

  165796.   }

  165797. 

  165798.   /* Count the tokens in this AND/NEAR cluster. If none of the doclists

  165799.   ** associated with the tokens spill onto overflow pages, or if there is

  165800.   ** only 1 token, exit early. No tokens to defer in this case. */

  165801.   for(ii=0; ii<nTC; ii++){

  165802.     if( aTC[ii].pRoot==pRoot ){

  165803.       nOvfl += aTC[ii].nOvfl;

  165804.       nToken++;

  165805.     }

  165806.   }

  165807.   if( nOvfl==0 || nToken<2 ) return SQLITE_OK;

  165808. 

  165809.   /* Obtain the average docsize (in pages). */

  165810.   rc = fts3EvalAverageDocsize(pCsr, &nDocSize);

  165811.   assert( rc!=SQLITE_OK || nDocSize>0 );

  165812. 

  165813. 

  165814.   /* Iterate through all tokens in this AND/NEAR cluster, in ascending order 

  165815.   ** of the number of overflow pages that will be loaded by the pager layer 

  165816.   ** to retrieve the entire doclist for the token from the full-text index.

  165817.   ** Load the doclists for tokens that are either:

  165818.   **

  165819.   **   a. The cheapest token in the entire query (i.e. the one visited by the

  165820.   **      first iteration of this loop), or

  165821.   **

  165822.   **   b. Part of a multi-token phrase.

  165823.   **

  165824.   ** After each token doclist is loaded, merge it with the others from the

  165825.   ** same phrase and count the number of documents that the merged doclist

  165826.   ** contains. Set variable "nMinEst" to the smallest number of documents in 

  165827.   ** any phrase doclist for which 1 or more token doclists have been loaded.

  165828.   ** Let nOther be the number of other phrases for which it is certain that

  165829.   ** one or more tokens will not be deferred.

  165830.   **

  165831.   ** Then, for each token, defer it if loading the doclist would result in

  165832.   ** loading N or more overflow pages into memory, where N is computed as:

  165833.   **

  165834.   **    (nMinEst + 4^nOther - 1) / (4^nOther)

  165835.   */

  165836.   for(ii=0; ii<nToken && rc==SQLITE_OK; ii++){

  165837.     int iTC;                      /* Used to iterate through aTC[] array. */

  165838.     Fts3TokenAndCost *pTC = 0;    /* Set to cheapest remaining token. */

  165839. 

  165840.     /* Set pTC to point to the cheapest remaining token. */

  165841.     for(iTC=0; iTC<nTC; iTC++){

  165842.       if( aTC[iTC].pToken && aTC[iTC].pRoot==pRoot 

  165843.        && (!pTC || aTC[iTC].nOvfl<pTC->nOvfl) 

  165844.       ){

  165845.         pTC = &aTC[iTC];

  165846.       }

  165847.     }

  165848.     assert( pTC );

  165849. 

  165850.     if( ii && pTC->nOvfl>=((nMinEst+(nLoad4/4)-1)/(nLoad4/4))*nDocSize ){

  165851.       /* The number of overflow pages to load for this (and therefore all

  165852.       ** subsequent) tokens is greater than the estimated number of pages 

  165853.       ** that will be loaded if all subsequent tokens are deferred.

  165854.       */

  165855.       Fts3PhraseToken *pToken = pTC->pToken;

  165856.       rc = sqlite3Fts3DeferToken(pCsr, pToken, pTC->iCol);

  165857.       fts3SegReaderCursorFree(pToken->pSegcsr);

  165858.       pToken->pSegcsr = 0;

  165859.     }else{

  165860.       /* Set nLoad4 to the value of (4^nOther) for the next iteration of the

  165861.       ** for-loop. Except, limit the value to 2^24 to prevent it from 

  165862.       ** overflowing the 32-bit integer it is stored in. */

  165863.       if( ii<12 ) nLoad4 = nLoad4*4;

  165864. 

  165865.       if( ii==0 || (pTC->pPhrase->nToken>1 && ii!=nToken-1) ){

  165866.         /* Either this is the cheapest token in the entire query, or it is

  165867.         ** part of a multi-token phrase. Either way, the entire doclist will

  165868.         ** (eventually) be loaded into memory. It may as well be now. */

  165869.         Fts3PhraseToken *pToken = pTC->pToken;

  165870.         int nList = 0;

  165871.         char *pList = 0;

  165872.         rc = fts3TermSelect(pTab, pToken, pTC->iCol, &nList, &pList);

  165873.         assert( rc==SQLITE_OK || pList==0 );

  165874.         if( rc==SQLITE_OK ){

  165875.           rc = fts3EvalPhraseMergeToken(

  165876.               pTab, pTC->pPhrase, pTC->iToken,pList,nList

  165877.           );

  165878.         }

  165879.         if( rc==SQLITE_OK ){

  165880.           int nCount;

  165881.           nCount = fts3DoclistCountDocids(

  165882.               pTC->pPhrase->doclist.aAll, pTC->pPhrase->doclist.nAll

  165883.           );

  165884.           if( ii==0 || nCount<nMinEst ) nMinEst = nCount;

  165885.         }

  165886.       }

  165887.     }

  165888.     pTC->pToken = 0;

  165889.   }

  165890. 

  165891.   return rc;

  165892. }

  165893. 

  165894. /*

  165895. ** This function is called from within the xFilter method. It initializes

  165896. ** the full-text query currently stored in pCsr->pExpr. To iterate through

  165897. ** the results of a query, the caller does:

  165898. **

  165899. **    fts3EvalStart(pCsr);

  165900. **    while( 1 ){

  165901. **      fts3EvalNext(pCsr);

  165902. **      if( pCsr->bEof ) break;

  165903. **      ... return row pCsr->iPrevId to the caller ...

  165904. **    }

  165905. */

  165906. static int fts3EvalStart(Fts3Cursor *pCsr){

  165907.   Fts3Table *pTab = (Fts3Table *)pCsr->base.pVtab;

  165908.   int rc = SQLITE_OK;

  165909.   int nToken = 0;

  165910.   int nOr = 0;

  165911. 

  165912.   /* Allocate a MultiSegReader for each token in the expression. */

  165913.   fts3EvalAllocateReaders(pCsr, pCsr->pExpr, &nToken, &nOr, &rc);

  165914. 

  165915.   /* Determine which, if any, tokens in the expression should be deferred. */

  165916. #ifndef SQLITE_DISABLE_FTS4_DEFERRED

  165917.   if( rc==SQLITE_OK && nToken>1 && pTab->bFts4 ){

  165918.     Fts3TokenAndCost *aTC;

  165919.     Fts3Expr **apOr;

  165920.     aTC = (Fts3TokenAndCost *)sqlite3_malloc64(

  165921.         sizeof(Fts3TokenAndCost) * nToken

  165922.       + sizeof(Fts3Expr *) * nOr * 2

  165923.     );

  165924.     apOr = (Fts3Expr **)&aTC[nToken];

  165925. 

  165926.     if( !aTC ){

  165927.       rc = SQLITE_NOMEM;

  165928.     }else{

  165929.       int ii;

  165930.       Fts3TokenAndCost *pTC = aTC;

  165931.       Fts3Expr **ppOr = apOr;

  165932. 

  165933.       fts3EvalTokenCosts(pCsr, 0, pCsr->pExpr, &pTC, &ppOr, &rc);

  165934.       nToken = (int)(pTC-aTC);

  165935.       nOr = (int)(ppOr-apOr);

  165936. 

  165937.       if( rc==SQLITE_OK ){

  165938.         rc = fts3EvalSelectDeferred(pCsr, 0, aTC, nToken);

  165939.         for(ii=0; rc==SQLITE_OK && ii<nOr; ii++){

  165940.           rc = fts3EvalSelectDeferred(pCsr, apOr[ii], aTC, nToken);

  165941.         }

  165942.       }

  165943. 

  165944.       sqlite3_free(aTC);

  165945.     }

  165946.   }

  165947. #endif

  165948. 

  165949.   fts3EvalStartReaders(pCsr, pCsr->pExpr, &rc);

  165950.   return rc;

  165951. }

  165952. 

  165953. /*

  165954. ** Invalidate the current position list for phrase pPhrase.

  165955. */

  165956. static void fts3EvalInvalidatePoslist(Fts3Phrase *pPhrase){

  165957.   if( pPhrase->doclist.bFreeList ){

  165958.     sqlite3_free(pPhrase->doclist.pList);

  165959.   }

  165960.   pPhrase->doclist.pList = 0;

  165961.   pPhrase->doclist.nList = 0;

  165962.   pPhrase->doclist.bFreeList = 0;

  165963. }

  165964. 

  165965. /*

  165966. ** This function is called to edit the position list associated with

  165967. ** the phrase object passed as the fifth argument according to a NEAR

  165968. ** condition. For example:

  165969. **

  165970. **     abc NEAR/5 "def ghi"

  165971. **

  165972. ** Parameter nNear is passed the NEAR distance of the expression (5 in

  165973. ** the example above). When this function is called, *paPoslist points to

  165974. ** the position list, and *pnToken is the number of phrase tokens in, the

  165975. ** phrase on the other side of the NEAR operator to pPhrase. For example,

  165976. ** if pPhrase refers to the "def ghi" phrase, then *paPoslist points to

  165977. ** the position list associated with phrase "abc".

  165978. **

  165979. ** All positions in the pPhrase position list that are not sufficiently

  165980. ** close to a position in the *paPoslist position list are removed. If this

  165981. ** leaves 0 positions, zero is returned. Otherwise, non-zero.

  165982. **

  165983. ** Before returning, *paPoslist is set to point to the position lsit 

  165984. ** associated with pPhrase. And *pnToken is set to the number of tokens in

  165985. ** pPhrase.

  165986. */

  165987. static int fts3EvalNearTrim(

  165988.   int nNear,                      /* NEAR distance. As in "NEAR/nNear". */

  165989.   char *aTmp,                     /* Temporary space to use */

  165990.   char **paPoslist,               /* IN/OUT: Position list */

  165991.   int *pnToken,                   /* IN/OUT: Tokens in phrase of *paPoslist */

  165992.   Fts3Phrase *pPhrase             /* The phrase object to trim the doclist of */

  165993. ){

  165994.   int nParam1 = nNear + pPhrase->nToken;

  165995.   int nParam2 = nNear + *pnToken;

  165996.   int nNew;

  165997.   char *p2; 

  165998.   char *pOut; 

  165999.   int res;

  166000. 

  166001.   assert( pPhrase->doclist.pList );

  166002. 

  166003.   p2 = pOut = pPhrase->doclist.pList;

  166004.   res = fts3PoslistNearMerge(

  166005.     &pOut, aTmp, nParam1, nParam2, paPoslist, &p2

  166006.   );

  166007.   if( res ){

  166008.     nNew = (int)(pOut - pPhrase->doclist.pList) - 1;

  166009.     assert( pPhrase->doclist.pList[nNew]=='\0' );

  166010.     assert( nNew<=pPhrase->doclist.nList && nNew>0 );

  166011.     memset(&pPhrase->doclist.pList[nNew], 0, pPhrase->doclist.nList - nNew);

  166012.     pPhrase->doclist.nList = nNew;

  166013.     *paPoslist = pPhrase->doclist.pList;

  166014.     *pnToken = pPhrase->nToken;

  166015.   }

  166016. 

  166017.   return res;

  166018. }

  166019. 

  166020. /*

  166021. ** This function is a no-op if *pRc is other than SQLITE_OK when it is called.

  166022. ** Otherwise, it advances the expression passed as the second argument to

  166023. ** point to the next matching row in the database. Expressions iterate through

  166024. ** matching rows in docid order. Ascending order if Fts3Cursor.bDesc is zero,

  166025. ** or descending if it is non-zero.

  166026. **

  166027. ** If an error occurs, *pRc is set to an SQLite error code. Otherwise, if

  166028. ** successful, the following variables in pExpr are set:

  166029. **

  166030. **   Fts3Expr.bEof                (non-zero if EOF - there is no next row)

  166031. **   Fts3Expr.iDocid              (valid if bEof==0. The docid of the next row)

  166032. **

  166033. ** If the expression is of type FTSQUERY_PHRASE, and the expression is not

  166034. ** at EOF, then the following variables are populated with the position list

  166035. ** for the phrase for the visited row:

  166036. **

  166037. **   FTs3Expr.pPhrase->doclist.nList        (length of pList in bytes)

  166038. **   FTs3Expr.pPhrase->doclist.pList        (pointer to position list)

  166039. **

  166040. ** It says above that this function advances the expression to the next

  166041. ** matching row. This is usually true, but there are the following exceptions:

  166042. **

  166043. **   1. Deferred tokens are not taken into account. If a phrase consists

  166044. **      entirely of deferred tokens, it is assumed to match every row in

  166045. **      the db. In this case the position-list is not populated at all. 

  166046. **

  166047. **      Or, if a phrase contains one or more deferred tokens and one or

  166048. **      more non-deferred tokens, then the expression is advanced to the 

  166049. **      next possible match, considering only non-deferred tokens. In other

  166050. **      words, if the phrase is "A B C", and "B" is deferred, the expression

  166051. **      is advanced to the next row that contains an instance of "A * C", 

  166052. **      where "*" may match any single token. The position list in this case

  166053. **      is populated as for "A * C" before returning.

  166054. **

  166055. **   2. NEAR is treated as AND. If the expression is "x NEAR y", it is 

  166056. **      advanced to point to the next row that matches "x AND y".

  166057. ** 

  166058. ** See sqlite3Fts3EvalTestDeferred() for details on testing if a row is

  166059. ** really a match, taking into account deferred tokens and NEAR operators.

  166060. */

  166061. static void fts3EvalNextRow(

  166062.   Fts3Cursor *pCsr,               /* FTS Cursor handle */

  166063.   Fts3Expr *pExpr,                /* Expr. to advance to next matching row */

  166064.   int *pRc                        /* IN/OUT: Error code */

  166065. ){

  166066.   if( *pRc==SQLITE_OK ){

  166067.     int bDescDoclist = pCsr->bDesc;         /* Used by DOCID_CMP() macro */

  166068.     assert( pExpr->bEof==0 );

  166069.     pExpr->bStart = 1;

  166070. 

  166071.     switch( pExpr->eType ){

  166072.       case FTSQUERY_NEAR:

  166073.       case FTSQUERY_AND: {

  166074.         Fts3Expr *pLeft = pExpr->pLeft;

  166075.         Fts3Expr *pRight = pExpr->pRight;

  166076.         assert( !pLeft->bDeferred || !pRight->bDeferred );

  166077. 

  166078.         if( pLeft->bDeferred ){

  166079.           /* LHS is entirely deferred. So we assume it matches every row.

  166080.           ** Advance the RHS iterator to find the next row visited. */

  166081.           fts3EvalNextRow(pCsr, pRight, pRc);

  166082.           pExpr->iDocid = pRight->iDocid;

  166083.           pExpr->bEof = pRight->bEof;

  166084.         }else if( pRight->bDeferred ){

  166085.           /* RHS is entirely deferred. So we assume it matches every row.

  166086.           ** Advance the LHS iterator to find the next row visited. */

  166087.           fts3EvalNextRow(pCsr, pLeft, pRc);

  166088.           pExpr->iDocid = pLeft->iDocid;

  166089.           pExpr->bEof = pLeft->bEof;

  166090.         }else{

  166091.           /* Neither the RHS or LHS are deferred. */

  166092.           fts3EvalNextRow(pCsr, pLeft, pRc);

  166093.           fts3EvalNextRow(pCsr, pRight, pRc);

  166094.           while( !pLeft->bEof && !pRight->bEof && *pRc==SQLITE_OK ){

  166095.             sqlite3_int64 iDiff = DOCID_CMP(pLeft->iDocid, pRight->iDocid);

  166096.             if( iDiff==0 ) break;

  166097.             if( iDiff<0 ){

  166098.               fts3EvalNextRow(pCsr, pLeft, pRc);

  166099.             }else{

  166100.               fts3EvalNextRow(pCsr, pRight, pRc);

  166101.             }

  166102.           }

  166103.           pExpr->iDocid = pLeft->iDocid;

  166104.           pExpr->bEof = (pLeft->bEof || pRight->bEof);

  166105.           if( pExpr->eType==FTSQUERY_NEAR && pExpr->bEof ){

  166106.             assert( pRight->eType==FTSQUERY_PHRASE );

  166107.             if( pRight->pPhrase->doclist.aAll ){

  166108.               Fts3Doclist *pDl = &pRight->pPhrase->doclist;

  166109.               while( *pRc==SQLITE_OK && pRight->bEof==0 ){

  166110.                 memset(pDl->pList, 0, pDl->nList);

  166111.                 fts3EvalNextRow(pCsr, pRight, pRc);

  166112.               }

  166113.             }

  166114.             if( pLeft->pPhrase && pLeft->pPhrase->doclist.aAll ){

  166115.               Fts3Doclist *pDl = &pLeft->pPhrase->doclist;

  166116.               while( *pRc==SQLITE_OK && pLeft->bEof==0 ){

  166117.                 memset(pDl->pList, 0, pDl->nList);

  166118.                 fts3EvalNextRow(pCsr, pLeft, pRc);

  166119.               }

  166120.             }

  166121.           }

  166122.         }

  166123.         break;

  166124.       }

  166125.   

  166126.       case FTSQUERY_OR: {

  166127.         Fts3Expr *pLeft = pExpr->pLeft;

  166128.         Fts3Expr *pRight = pExpr->pRight;

  166129.         sqlite3_int64 iCmp = DOCID_CMP(pLeft->iDocid, pRight->iDocid);

  166130. 

  166131.         assert( pLeft->bStart || pLeft->iDocid==pRight->iDocid );

  166132.         assert( pRight->bStart || pLeft->iDocid==pRight->iDocid );

  166133. 

  166134.         if( pRight->bEof || (pLeft->bEof==0 && iCmp<0) ){

  166135.           fts3EvalNextRow(pCsr, pLeft, pRc);

  166136.         }else if( pLeft->bEof || iCmp>0 ){

  166137.           fts3EvalNextRow(pCsr, pRight, pRc);

  166138.         }else{

  166139.           fts3EvalNextRow(pCsr, pLeft, pRc);

  166140.           fts3EvalNextRow(pCsr, pRight, pRc);

  166141.         }

  166142. 

  166143.         pExpr->bEof = (pLeft->bEof && pRight->bEof);

  166144.         iCmp = DOCID_CMP(pLeft->iDocid, pRight->iDocid);

  166145.         if( pRight->bEof || (pLeft->bEof==0 &&  iCmp<0) ){

  166146.           pExpr->iDocid = pLeft->iDocid;

  166147.         }else{

  166148.           pExpr->iDocid = pRight->iDocid;

  166149.         }

  166150. 

  166151.         break;

  166152.       }

  166153. 

  166154.       case FTSQUERY_NOT: {

  166155.         Fts3Expr *pLeft = pExpr->pLeft;

  166156.         Fts3Expr *pRight = pExpr->pRight;

  166157. 

  166158.         if( pRight->bStart==0 ){

  166159.           fts3EvalNextRow(pCsr, pRight, pRc);

  166160.           assert( *pRc!=SQLITE_OK || pRight->bStart );

  166161.         }

  166162. 

  166163.         fts3EvalNextRow(pCsr, pLeft, pRc);

  166164.         if( pLeft->bEof==0 ){

  166165.           while( !*pRc 

  166166.               && !pRight->bEof 

  166167.               && DOCID_CMP(pLeft->iDocid, pRight->iDocid)>0 

  166168.           ){

  166169.             fts3EvalNextRow(pCsr, pRight, pRc);

  166170.           }

  166171.         }

  166172.         pExpr->iDocid = pLeft->iDocid;

  166173.         pExpr->bEof = pLeft->bEof;

  166174.         break;

  166175.       }

  166176. 

  166177.       default: {

  166178.         Fts3Phrase *pPhrase = pExpr->pPhrase;

  166179.         fts3EvalInvalidatePoslist(pPhrase);

  166180.         *pRc = fts3EvalPhraseNext(pCsr, pPhrase, &pExpr->bEof);

  166181.         pExpr->iDocid = pPhrase->doclist.iDocid;

  166182.         break;

  166183.       }

  166184.     }

  166185.   }

  166186. }

  166187. 

  166188. /*

  166189. ** If *pRc is not SQLITE_OK, or if pExpr is not the root node of a NEAR

  166190. ** cluster, then this function returns 1 immediately.

  166191. **

  166192. ** Otherwise, it checks if the current row really does match the NEAR 

  166193. ** expression, using the data currently stored in the position lists 

  166194. ** (Fts3Expr->pPhrase.doclist.pList/nList) for each phrase in the expression. 

  166195. **

  166196. ** If the current row is a match, the position list associated with each

  166197. ** phrase in the NEAR expression is edited in place to contain only those

  166198. ** phrase instances sufficiently close to their peers to satisfy all NEAR

  166199. ** constraints. In this case it returns 1. If the NEAR expression does not 

  166200. ** match the current row, 0 is returned. The position lists may or may not

  166201. ** be edited if 0 is returned.

  166202. */

  166203. static int fts3EvalNearTest(Fts3Expr *pExpr, int *pRc){

  166204.   int res = 1;

  166205. 

  166206.   /* The following block runs if pExpr is the root of a NEAR query.

  166207.   ** For example, the query:

  166208.   **

  166209.   **         "w" NEAR "x" NEAR "y" NEAR "z"

  166210.   **

  166211.   ** which is represented in tree form as:

  166212.   **

  166213.   **                               |

  166214.   **                          +--NEAR--+      <-- root of NEAR query

  166215.   **                          |        |

  166216.   **                     +--NEAR--+   "z"

  166217.   **                     |        |

  166218.   **                +--NEAR--+   "y"

  166219.   **                |        |

  166220.   **               "w"      "x"

  166221.   **

  166222.   ** The right-hand child of a NEAR node is always a phrase. The 

  166223.   ** left-hand child may be either a phrase or a NEAR node. There are

  166224.   ** no exceptions to this - it's the way the parser in fts3_expr.c works.

  166225.   */

  166226.   if( *pRc==SQLITE_OK 

  166227.    && pExpr->eType==FTSQUERY_NEAR 

  166228.    && (pExpr->pParent==0 || pExpr->pParent->eType!=FTSQUERY_NEAR)

  166229.   ){

  166230.     Fts3Expr *p; 

  166231.     sqlite3_int64 nTmp = 0;       /* Bytes of temp space */

  166232.     char *aTmp;                   /* Temp space for PoslistNearMerge() */

  166233. 

  166234.     /* Allocate temporary working space. */

  166235.     for(p=pExpr; p->pLeft; p=p->pLeft){

  166236.       assert( p->pRight->pPhrase->doclist.nList>0 );

  166237.       nTmp += p->pRight->pPhrase->doclist.nList;

  166238.     }

  166239.     nTmp += p->pPhrase->doclist.nList;

  166240.     aTmp = sqlite3_malloc64(nTmp*2);

  166241.     if( !aTmp ){

  166242.       *pRc = SQLITE_NOMEM;

  166243.       res = 0;

  166244.     }else{

  166245.       char *aPoslist = p->pPhrase->doclist.pList;

  166246.       int nToken = p->pPhrase->nToken;

  166247. 

  166248.       for(p=p->pParent;res && p && p->eType==FTSQUERY_NEAR; p=p->pParent){

  166249.         Fts3Phrase *pPhrase = p->pRight->pPhrase;

  166250.         int nNear = p->nNear;

  166251.         res = fts3EvalNearTrim(nNear, aTmp, &aPoslist, &nToken, pPhrase);

  166252.       }

  166253. 

  166254.       aPoslist = pExpr->pRight->pPhrase->doclist.pList;

  166255.       nToken = pExpr->pRight->pPhrase->nToken;

  166256.       for(p=pExpr->pLeft; p && res; p=p->pLeft){

  166257.         int nNear;

  166258.         Fts3Phrase *pPhrase;

  166259.         assert( p->pParent && p->pParent->pLeft==p );

  166260.         nNear = p->pParent->nNear;

  166261.         pPhrase = (

  166262.             p->eType==FTSQUERY_NEAR ? p->pRight->pPhrase : p->pPhrase

  166263.         );

  166264.         res = fts3EvalNearTrim(nNear, aTmp, &aPoslist, &nToken, pPhrase);

  166265.       }

  166266.     }

  166267. 

  166268.     sqlite3_free(aTmp);

  166269.   }

  166270. 

  166271.   return res;

  166272. }

  166273. 

  166274. /*

  166275. ** This function is a helper function for sqlite3Fts3EvalTestDeferred().

  166276. ** Assuming no error occurs or has occurred, It returns non-zero if the

  166277. ** expression passed as the second argument matches the row that pCsr 

  166278. ** currently points to, or zero if it does not.

  166279. **

  166280. ** If *pRc is not SQLITE_OK when this function is called, it is a no-op.

  166281. ** If an error occurs during execution of this function, *pRc is set to 

  166282. ** the appropriate SQLite error code. In this case the returned value is 

  166283. ** undefined.

  166284. */

  166285. static int fts3EvalTestExpr(

  166286.   Fts3Cursor *pCsr,               /* FTS cursor handle */

  166287.   Fts3Expr *pExpr,                /* Expr to test. May or may not be root. */

  166288.   int *pRc                        /* IN/OUT: Error code */

  166289. ){

  166290.   int bHit = 1;                   /* Return value */

  166291.   if( *pRc==SQLITE_OK ){

  166292.     switch( pExpr->eType ){

  166293.       case FTSQUERY_NEAR:

  166294.       case FTSQUERY_AND:

  166295.         bHit = (

  166296.             fts3EvalTestExpr(pCsr, pExpr->pLeft, pRc)

  166297.          && fts3EvalTestExpr(pCsr, pExpr->pRight, pRc)

  166298.          && fts3EvalNearTest(pExpr, pRc)

  166299.         );

  166300. 

  166301.         /* If the NEAR expression does not match any rows, zero the doclist for 

  166302.         ** all phrases involved in the NEAR. This is because the snippet(),

  166303.         ** offsets() and matchinfo() functions are not supposed to recognize 

  166304.         ** any instances of phrases that are part of unmatched NEAR queries. 

  166305.         ** For example if this expression:

  166306.         **

  166307.         **    ... MATCH 'a OR (b NEAR c)'

  166308.         **

  166309.         ** is matched against a row containing:

  166310.         **

  166311.         **        'a b d e'

  166312.         **

  166313.         ** then any snippet() should ony highlight the "a" term, not the "b"

  166314.         ** (as "b" is part of a non-matching NEAR clause).

  166315.         */

  166316.         if( bHit==0 

  166317.          && pExpr->eType==FTSQUERY_NEAR 

  166318.          && (pExpr->pParent==0 || pExpr->pParent->eType!=FTSQUERY_NEAR)

  166319.         ){

  166320.           Fts3Expr *p;

  166321.           for(p=pExpr; p->pPhrase==0; p=p->pLeft){

  166322.             if( p->pRight->iDocid==pCsr->iPrevId ){

  166323.               fts3EvalInvalidatePoslist(p->pRight->pPhrase);

  166324.             }

  166325.           }

  166326.           if( p->iDocid==pCsr->iPrevId ){

  166327.             fts3EvalInvalidatePoslist(p->pPhrase);

  166328.           }

  166329.         }

  166330. 

  166331.         break;

  166332. 

  166333.       case FTSQUERY_OR: {

  166334.         int bHit1 = fts3EvalTestExpr(pCsr, pExpr->pLeft, pRc);

  166335.         int bHit2 = fts3EvalTestExpr(pCsr, pExpr->pRight, pRc);

  166336.         bHit = bHit1 || bHit2;

  166337.         break;

  166338.       }

  166339. 

  166340.       case FTSQUERY_NOT:

  166341.         bHit = (

  166342.             fts3EvalTestExpr(pCsr, pExpr->pLeft, pRc)

  166343.          && !fts3EvalTestExpr(pCsr, pExpr->pRight, pRc)

  166344.         );

  166345.         break;

  166346. 

  166347.       default: {

  166348. #ifndef SQLITE_DISABLE_FTS4_DEFERRED

  166349.         if( pCsr->pDeferred 

  166350.          && (pExpr->iDocid==pCsr->iPrevId || pExpr->bDeferred)

  166351.         ){

  166352.           Fts3Phrase *pPhrase = pExpr->pPhrase;

  166353.           assert( pExpr->bDeferred || pPhrase->doclist.bFreeList==0 );

  166354.           if( pExpr->bDeferred ){

  166355.             fts3EvalInvalidatePoslist(pPhrase);

  166356.           }

  166357.           *pRc = fts3EvalDeferredPhrase(pCsr, pPhrase);

  166358.           bHit = (pPhrase->doclist.pList!=0);

  166359.           pExpr->iDocid = pCsr->iPrevId;

  166360.         }else

  166361. #endif

  166362.         {

  166363.           bHit = (pExpr->bEof==0 && pExpr->iDocid==pCsr->iPrevId);

  166364.         }

  166365.         break;

  166366.       }

  166367.     }

  166368.   }

  166369.   return bHit;

  166370. }

  166371. 

  166372. /*

  166373. ** This function is called as the second part of each xNext operation when

  166374. ** iterating through the results of a full-text query. At this point the

  166375. ** cursor points to a row that matches the query expression, with the

  166376. ** following caveats:

  166377. **

  166378. **   * Up until this point, "NEAR" operators in the expression have been

  166379. **     treated as "AND".

  166380. **

  166381. **   * Deferred tokens have not yet been considered.

  166382. **

  166383. ** If *pRc is not SQLITE_OK when this function is called, it immediately

  166384. ** returns 0. Otherwise, it tests whether or not after considering NEAR

  166385. ** operators and deferred tokens the current row is still a match for the

  166386. ** expression. It returns 1 if both of the following are true:

  166387. **

  166388. **   1. *pRc is SQLITE_OK when this function returns, and

  166389. **

  166390. **   2. After scanning the current FTS table row for the deferred tokens,

  166391. **      it is determined that the row does *not* match the query.

  166392. **

  166393. ** Or, if no error occurs and it seems the current row does match the FTS

  166394. ** query, return 0.

  166395. */

  166396. SQLITE_PRIVATE int sqlite3Fts3EvalTestDeferred(Fts3Cursor *pCsr, int *pRc){

  166397.   int rc = *pRc;

  166398.   int bMiss = 0;

  166399.   if( rc==SQLITE_OK ){

  166400. 

  166401.     /* If there are one or more deferred tokens, load the current row into

  166402.     ** memory and scan it to determine the position list for each deferred

  166403.     ** token. Then, see if this row is really a match, considering deferred

  166404.     ** tokens and NEAR operators (neither of which were taken into account

  166405.     ** earlier, by fts3EvalNextRow()). 

  166406.     */

  166407.     if( pCsr->pDeferred ){

  166408.       rc = fts3CursorSeek(0, pCsr);

  166409.       if( rc==SQLITE_OK ){

  166410.         rc = sqlite3Fts3CacheDeferredDoclists(pCsr);

  166411.       }

  166412.     }

  166413.     bMiss = (0==fts3EvalTestExpr(pCsr, pCsr->pExpr, &rc));

  166414. 

  166415.     /* Free the position-lists accumulated for each deferred token above. */

  166416.     sqlite3Fts3FreeDeferredDoclists(pCsr);

  166417.     *pRc = rc;

  166418.   }

  166419.   return (rc==SQLITE_OK && bMiss);

  166420. }

  166421. 

  166422. /*

  166423. ** Advance to the next document that matches the FTS expression in

  166424. ** Fts3Cursor.pExpr.

  166425. */

  166426. static int fts3EvalNext(Fts3Cursor *pCsr){

  166427.   int rc = SQLITE_OK;             /* Return Code */

  166428.   Fts3Expr *pExpr = pCsr->pExpr;

  166429.   assert( pCsr->isEof==0 );

  166430.   if( pExpr==0 ){

  166431.     pCsr->isEof = 1;

  166432.   }else{

  166433.     do {

  166434.       if( pCsr->isRequireSeek==0 ){

  166435.         sqlite3_reset(pCsr->pStmt);

  166436.       }

  166437.       assert( sqlite3_data_count(pCsr->pStmt)==0 );

  166438.       fts3EvalNextRow(pCsr, pExpr, &rc);

  166439.       pCsr->isEof = pExpr->bEof;

  166440.       pCsr->isRequireSeek = 1;

  166441.       pCsr->isMatchinfoNeeded = 1;

  166442.       pCsr->iPrevId = pExpr->iDocid;

  166443.     }while( pCsr->isEof==0 && sqlite3Fts3EvalTestDeferred(pCsr, &rc) );

  166444.   }

  166445. 

  166446.   /* Check if the cursor is past the end of the docid range specified

  166447.   ** by Fts3Cursor.iMinDocid/iMaxDocid. If so, set the EOF flag.  */

  166448.   if( rc==SQLITE_OK && (

  166449.         (pCsr->bDesc==0 && pCsr->iPrevId>pCsr->iMaxDocid)

  166450.      || (pCsr->bDesc!=0 && pCsr->iPrevId<pCsr->iMinDocid)

  166451.   )){

  166452.     pCsr->isEof = 1;

  166453.   }

  166454. 

  166455.   return rc;

  166456. }

  166457. 

  166458. /*

  166459. ** Restart interation for expression pExpr so that the next call to

  166460. ** fts3EvalNext() visits the first row. Do not allow incremental 

  166461. ** loading or merging of phrase doclists for this iteration.

  166462. **

  166463. ** If *pRc is other than SQLITE_OK when this function is called, it is

  166464. ** a no-op. If an error occurs within this function, *pRc is set to an

  166465. ** SQLite error code before returning.

  166466. */

  166467. static void fts3EvalRestart(

  166468.   Fts3Cursor *pCsr,

  166469.   Fts3Expr *pExpr,

  166470.   int *pRc

  166471. ){

  166472.   if( pExpr && *pRc==SQLITE_OK ){

  166473.     Fts3Phrase *pPhrase = pExpr->pPhrase;

  166474. 

  166475.     if( pPhrase ){

  166476.       fts3EvalInvalidatePoslist(pPhrase);

  166477.       if( pPhrase->bIncr ){

  166478.         int i;

  166479.         for(i=0; i<pPhrase->nToken; i++){

  166480.           Fts3PhraseToken *pToken = &pPhrase->aToken[i];

  166481.           assert( pToken->pDeferred==0 );

  166482.           if( pToken->pSegcsr ){

  166483.             sqlite3Fts3MsrIncrRestart(pToken->pSegcsr);

  166484.           }

  166485.         }

  166486.         *pRc = fts3EvalPhraseStart(pCsr, 0, pPhrase);

  166487.       }

  166488.       pPhrase->doclist.pNextDocid = 0;

  166489.       pPhrase->doclist.iDocid = 0;

  166490.       pPhrase->pOrPoslist = 0;

  166491.     }

  166492. 

  166493.     pExpr->iDocid = 0;

  166494.     pExpr->bEof = 0;

  166495.     pExpr->bStart = 0;

  166496. 

  166497.     fts3EvalRestart(pCsr, pExpr->pLeft, pRc);

  166498.     fts3EvalRestart(pCsr, pExpr->pRight, pRc);

  166499.   }

  166500. }

  166501. 

  166502. /*

  166503. ** After allocating the Fts3Expr.aMI[] array for each phrase in the 

  166504. ** expression rooted at pExpr, the cursor iterates through all rows matched

  166505. ** by pExpr, calling this function for each row. This function increments

  166506. ** the values in Fts3Expr.aMI[] according to the position-list currently

  166507. ** found in Fts3Expr.pPhrase->doclist.pList for each of the phrase 

  166508. ** expression nodes.

  166509. */

  166510. static void fts3EvalUpdateCounts(Fts3Expr *pExpr, int nCol){

  166511.   if( pExpr ){

  166512.     Fts3Phrase *pPhrase = pExpr->pPhrase;

  166513.     if( pPhrase && pPhrase->doclist.pList ){

  166514.       int iCol = 0;

  166515.       char *p = pPhrase->doclist.pList;

  166516. 

  166517.       do{

  166518.         u8 c = 0;

  166519.         int iCnt = 0;

  166520.         while( 0xFE & (*p | c) ){

  166521.           if( (c&0x80)==0 ) iCnt++;

  166522.           c = *p++ & 0x80;

  166523.         }

  166524. 

  166525.         /* aMI[iCol*3 + 1] = Number of occurrences

  166526.         ** aMI[iCol*3 + 2] = Number of rows containing at least one instance

  166527.         */

  166528.         pExpr->aMI[iCol*3 + 1] += iCnt;

  166529.         pExpr->aMI[iCol*3 + 2] += (iCnt>0);

  166530.         if( *p==0x00 ) break;

  166531.         p++;

  166532.         p += fts3GetVarint32(p, &iCol);

  166533.       }while( iCol<nCol );

  166534.     }

  166535. 

  166536.     fts3EvalUpdateCounts(pExpr->pLeft, nCol);

  166537.     fts3EvalUpdateCounts(pExpr->pRight, nCol);

  166538.   }

  166539. }

  166540. 

  166541. /*

  166542. ** Expression pExpr must be of type FTSQUERY_PHRASE.

  166543. **

  166544. ** If it is not already allocated and populated, this function allocates and

  166545. ** populates the Fts3Expr.aMI[] array for expression pExpr. If pExpr is part

  166546. ** of a NEAR expression, then it also allocates and populates the same array

  166547. ** for all other phrases that are part of the NEAR expression.

  166548. **

  166549. ** SQLITE_OK is returned if the aMI[] array is successfully allocated and

  166550. ** populated. Otherwise, if an error occurs, an SQLite error code is returned.

  166551. */

  166552. static int fts3EvalGatherStats(

  166553.   Fts3Cursor *pCsr,               /* Cursor object */

  166554.   Fts3Expr *pExpr                 /* FTSQUERY_PHRASE expression */

  166555. ){

  166556.   int rc = SQLITE_OK;             /* Return code */

  166557. 

  166558.   assert( pExpr->eType==FTSQUERY_PHRASE );

  166559.   if( pExpr->aMI==0 ){

  166560.     Fts3Table *pTab = (Fts3Table *)pCsr->base.pVtab;

  166561.     Fts3Expr *pRoot;                /* Root of NEAR expression */

  166562.     Fts3Expr *p;                    /* Iterator used for several purposes */

  166563. 

  166564.     sqlite3_int64 iPrevId = pCsr->iPrevId;

  166565.     sqlite3_int64 iDocid;

  166566.     u8 bEof;

  166567. 

  166568.     /* Find the root of the NEAR expression */

  166569.     pRoot = pExpr;

  166570.     while( pRoot->pParent && pRoot->pParent->eType==FTSQUERY_NEAR ){

  166571.       pRoot = pRoot->pParent;

  166572.     }

  166573.     iDocid = pRoot->iDocid;

  166574.     bEof = pRoot->bEof;

  166575.     assert( pRoot->bStart );

  166576. 

  166577.     /* Allocate space for the aMSI[] array of each FTSQUERY_PHRASE node */

  166578.     for(p=pRoot; p; p=p->pLeft){

  166579.       Fts3Expr *pE = (p->eType==FTSQUERY_PHRASE?p:p->pRight);

  166580.       assert( pE->aMI==0 );

  166581.       pE->aMI = (u32 *)sqlite3_malloc64(pTab->nColumn * 3 * sizeof(u32));

  166582.       if( !pE->aMI ) return SQLITE_NOMEM;

  166583.       memset(pE->aMI, 0, pTab->nColumn * 3 * sizeof(u32));

  166584.     }

  166585. 

  166586.     fts3EvalRestart(pCsr, pRoot, &rc);

  166587. 

  166588.     while( pCsr->isEof==0 && rc==SQLITE_OK ){

  166589. 

  166590.       do {

  166591.         /* Ensure the %_content statement is reset. */

  166592.         if( pCsr->isRequireSeek==0 ) sqlite3_reset(pCsr->pStmt);

  166593.         assert( sqlite3_data_count(pCsr->pStmt)==0 );

  166594. 

  166595.         /* Advance to the next document */

  166596.         fts3EvalNextRow(pCsr, pRoot, &rc);

  166597.         pCsr->isEof = pRoot->bEof;

  166598.         pCsr->isRequireSeek = 1;

  166599.         pCsr->isMatchinfoNeeded = 1;

  166600.         pCsr->iPrevId = pRoot->iDocid;

  166601.       }while( pCsr->isEof==0 

  166602.            && pRoot->eType==FTSQUERY_NEAR 

  166603.            && sqlite3Fts3EvalTestDeferred(pCsr, &rc) 

  166604.       );

  166605. 

  166606.       if( rc==SQLITE_OK && pCsr->isEof==0 ){

  166607.         fts3EvalUpdateCounts(pRoot, pTab->nColumn);

  166608.       }

  166609.     }

  166610. 

  166611.     pCsr->isEof = 0;

  166612.     pCsr->iPrevId = iPrevId;

  166613. 

  166614.     if( bEof ){

  166615.       pRoot->bEof = bEof;

  166616.     }else{

  166617.       /* Caution: pRoot may iterate through docids in ascending or descending

  166618.       ** order. For this reason, even though it seems more defensive, the 

  166619.       ** do loop can not be written:

  166620.       **

  166621.       **   do {...} while( pRoot->iDocid<iDocid && rc==SQLITE_OK );

  166622.       */

  166623.       fts3EvalRestart(pCsr, pRoot, &rc);

  166624.       do {

  166625.         fts3EvalNextRow(pCsr, pRoot, &rc);

  166626.         assert( pRoot->bEof==0 );

  166627.       }while( pRoot->iDocid!=iDocid && rc==SQLITE_OK );

  166628.     }

  166629.   }

  166630.   return rc;

  166631. }

  166632. 

  166633. /*

  166634. ** This function is used by the matchinfo() module to query a phrase 

  166635. ** expression node for the following information:

  166636. **

  166637. **   1. The total number of occurrences of the phrase in each column of 

  166638. **      the FTS table (considering all rows), and

  166639. **

  166640. **   2. For each column, the number of rows in the table for which the

  166641. **      column contains at least one instance of the phrase.

  166642. **

  166643. ** If no error occurs, SQLITE_OK is returned and the values for each column

  166644. ** written into the array aiOut as follows:

  166645. **

  166646. **   aiOut[iCol*3 + 1] = Number of occurrences

  166647. **   aiOut[iCol*3 + 2] = Number of rows containing at least one instance

  166648. **

  166649. ** Caveats:

  166650. **

  166651. **   * If a phrase consists entirely of deferred tokens, then all output 

  166652. **     values are set to the number of documents in the table. In other

  166653. **     words we assume that very common tokens occur exactly once in each 

  166654. **     column of each row of the table.

  166655. **

  166656. **   * If a phrase contains some deferred tokens (and some non-deferred 

  166657. **     tokens), count the potential occurrence identified by considering

  166658. **     the non-deferred tokens instead of actual phrase occurrences.

  166659. **

  166660. **   * If the phrase is part of a NEAR expression, then only phrase instances

  166661. **     that meet the NEAR constraint are included in the counts.

  166662. */

  166663. SQLITE_PRIVATE int sqlite3Fts3EvalPhraseStats(

  166664.   Fts3Cursor *pCsr,               /* FTS cursor handle */

  166665.   Fts3Expr *pExpr,                /* Phrase expression */

  166666.   u32 *aiOut                      /* Array to write results into (see above) */

  166667. ){

  166668.   Fts3Table *pTab = (Fts3Table *)pCsr->base.pVtab;

  166669.   int rc = SQLITE_OK;

  166670.   int iCol;

  166671. 

  166672.   if( pExpr->bDeferred && pExpr->pParent->eType!=FTSQUERY_NEAR ){

  166673.     assert( pCsr->nDoc>0 );

  166674.     for(iCol=0; iCol<pTab->nColumn; iCol++){

  166675.       aiOut[iCol*3 + 1] = (u32)pCsr->nDoc;

  166676.       aiOut[iCol*3 + 2] = (u32)pCsr->nDoc;

  166677.     }

  166678.   }else{

  166679.     rc = fts3EvalGatherStats(pCsr, pExpr);

  166680.     if( rc==SQLITE_OK ){

  166681.       assert( pExpr->aMI );

  166682.       for(iCol=0; iCol<pTab->nColumn; iCol++){

  166683.         aiOut[iCol*3 + 1] = pExpr->aMI[iCol*3 + 1];

  166684.         aiOut[iCol*3 + 2] = pExpr->aMI[iCol*3 + 2];

  166685.       }

  166686.     }

  166687.   }

  166688. 

  166689.   return rc;

  166690. }

  166691. 

  166692. /*

  166693. ** The expression pExpr passed as the second argument to this function

  166694. ** must be of type FTSQUERY_PHRASE. 

  166695. **

  166696. ** The returned value is either NULL or a pointer to a buffer containing

  166697. ** a position-list indicating the occurrences of the phrase in column iCol

  166698. ** of the current row. 

  166699. **

  166700. ** More specifically, the returned buffer contains 1 varint for each 

  166701. ** occurrence of the phrase in the column, stored using the normal (delta+2) 

  166702. ** compression and is terminated by either an 0x01 or 0x00 byte. For example,

  166703. ** if the requested column contains "a b X c d X X" and the position-list

  166704. ** for 'X' is requested, the buffer returned may contain:

  166705. **

  166706. **     0x04 0x05 0x03 0x01   or   0x04 0x05 0x03 0x00

  166707. **

  166708. ** This function works regardless of whether or not the phrase is deferred,

  166709. ** incremental, or neither.

  166710. */

  166711. SQLITE_PRIVATE int sqlite3Fts3EvalPhrasePoslist(

  166712.   Fts3Cursor *pCsr,               /* FTS3 cursor object */

  166713.   Fts3Expr *pExpr,                /* Phrase to return doclist for */

  166714.   int iCol,                       /* Column to return position list for */

  166715.   char **ppOut                    /* OUT: Pointer to position list */

  166716. ){

  166717.   Fts3Phrase *pPhrase = pExpr->pPhrase;

  166718.   Fts3Table *pTab = (Fts3Table *)pCsr->base.pVtab;

  166719.   char *pIter;

  166720.   int iThis;

  166721.   sqlite3_int64 iDocid;

  166722. 

  166723.   /* If this phrase is applies specifically to some column other than 

  166724.   ** column iCol, return a NULL pointer.  */

  166725.   *ppOut = 0;

  166726.   assert( iCol>=0 && iCol<pTab->nColumn );

  166727.   if( (pPhrase->iColumn<pTab->nColumn && pPhrase->iColumn!=iCol) ){

  166728.     return SQLITE_OK;

  166729.   }

  166730. 

  166731.   iDocid = pExpr->iDocid;

  166732.   pIter = pPhrase->doclist.pList;

  166733.   if( iDocid!=pCsr->iPrevId || pExpr->bEof ){

  166734.     int rc = SQLITE_OK;

  166735.     int bDescDoclist = pTab->bDescIdx;      /* For DOCID_CMP macro */

  166736.     int bOr = 0;

  166737.     u8 bTreeEof = 0;

  166738.     Fts3Expr *p;                  /* Used to iterate from pExpr to root */

  166739.     Fts3Expr *pNear;              /* Most senior NEAR ancestor (or pExpr) */

  166740.     int bMatch;

  166741. 

  166742.     /* Check if this phrase descends from an OR expression node. If not, 

  166743.     ** return NULL. Otherwise, the entry that corresponds to docid 

  166744.     ** pCsr->iPrevId may lie earlier in the doclist buffer. Or, if the

  166745.     ** tree that the node is part of has been marked as EOF, but the node

  166746.     ** itself is not EOF, then it may point to an earlier entry. */

  166747.     pNear = pExpr;

  166748.     for(p=pExpr->pParent; p; p=p->pParent){

  166749.       if( p->eType==FTSQUERY_OR ) bOr = 1;

  166750.       if( p->eType==FTSQUERY_NEAR ) pNear = p;

  166751.       if( p->bEof ) bTreeEof = 1;

  166752.     }

  166753.     if( bOr==0 ) return SQLITE_OK;

  166754. 

  166755.     /* This is the descendent of an OR node. In this case we cannot use

  166756.     ** an incremental phrase. Load the entire doclist for the phrase

  166757.     ** into memory in this case.  */

  166758.     if( pPhrase->bIncr ){

  166759.       int bEofSave = pNear->bEof;

  166760.       fts3EvalRestart(pCsr, pNear, &rc);

  166761.       while( rc==SQLITE_OK && !pNear->bEof ){

  166762.         fts3EvalNextRow(pCsr, pNear, &rc);

  166763.         if( bEofSave==0 && pNear->iDocid==iDocid ) break;

  166764.       }

  166765.       assert( rc!=SQLITE_OK || pPhrase->bIncr==0 );

  166766.     }

  166767.     if( bTreeEof ){

  166768.       while( rc==SQLITE_OK && !pNear->bEof ){

  166769.         fts3EvalNextRow(pCsr, pNear, &rc);

  166770.       }

  166771.     }

  166772.     if( rc!=SQLITE_OK ) return rc;

  166773. 

  166774.     bMatch = 1;

  166775.     for(p=pNear; p; p=p->pLeft){

  166776.       u8 bEof = 0;

  166777.       Fts3Expr *pTest = p;

  166778.       Fts3Phrase *pPh;

  166779.       assert( pTest->eType==FTSQUERY_NEAR || pTest->eType==FTSQUERY_PHRASE );

  166780.       if( pTest->eType==FTSQUERY_NEAR ) pTest = pTest->pRight;

  166781.       assert( pTest->eType==FTSQUERY_PHRASE );

  166782.       pPh = pTest->pPhrase;

  166783. 

  166784.       pIter = pPh->pOrPoslist;

  166785.       iDocid = pPh->iOrDocid;

  166786.       if( pCsr->bDesc==bDescDoclist ){

  166787.         bEof = !pPh->doclist.nAll ||

  166788.           (pIter >= (pPh->doclist.aAll + pPh->doclist.nAll));

  166789.         while( (pIter==0 || DOCID_CMP(iDocid, pCsr->iPrevId)<0 ) && bEof==0 ){

  166790.           sqlite3Fts3DoclistNext(

  166791.               bDescDoclist, pPh->doclist.aAll, pPh->doclist.nAll, 

  166792.               &pIter, &iDocid, &bEof

  166793.           );

  166794.         }

  166795.       }else{

  166796.         bEof = !pPh->doclist.nAll || (pIter && pIter<=pPh->doclist.aAll);

  166797.         while( (pIter==0 || DOCID_CMP(iDocid, pCsr->iPrevId)>0 ) && bEof==0 ){

  166798.           int dummy;

  166799.           sqlite3Fts3DoclistPrev(

  166800.               bDescDoclist, pPh->doclist.aAll, pPh->doclist.nAll, 

  166801.               &pIter, &iDocid, &dummy, &bEof

  166802.               );

  166803.         }

  166804.       }

  166805.       pPh->pOrPoslist = pIter;

  166806.       pPh->iOrDocid = iDocid;

  166807.       if( bEof || iDocid!=pCsr->iPrevId ) bMatch = 0;

  166808.     }

  166809. 

  166810.     if( bMatch ){

  166811.       pIter = pPhrase->pOrPoslist;

  166812.     }else{

  166813.       pIter = 0;

  166814.     }

  166815.   }

  166816.   if( pIter==0 ) return SQLITE_OK;

  166817. 

  166818.   if( *pIter==0x01 ){

  166819.     pIter++;

  166820.     pIter += fts3GetVarint32(pIter, &iThis);

  166821.   }else{

  166822.     iThis = 0;

  166823.   }

  166824.   while( iThis<iCol ){

  166825.     fts3ColumnlistCopy(0, &pIter);

  166826.     if( *pIter==0x00 ) return SQLITE_OK;

  166827.     pIter++;

  166828.     pIter += fts3GetVarint32(pIter, &iThis);

  166829.   }

  166830.   if( *pIter==0x00 ){

  166831.     pIter = 0;

  166832.   }

  166833. 

  166834.   *ppOut = ((iCol==iThis)?pIter:0);

  166835.   return SQLITE_OK;

  166836. }

  166837. 

  166838. /*

  166839. ** Free all components of the Fts3Phrase structure that were allocated by

  166840. ** the eval module. Specifically, this means to free:

  166841. **

  166842. **   * the contents of pPhrase->doclist, and

  166843. **   * any Fts3MultiSegReader objects held by phrase tokens.

  166844. */

  166845. SQLITE_PRIVATE void sqlite3Fts3EvalPhraseCleanup(Fts3Phrase *pPhrase){

  166846.   if( pPhrase ){

  166847.     int i;

  166848.     sqlite3_free(pPhrase->doclist.aAll);

  166849.     fts3EvalInvalidatePoslist(pPhrase);

  166850.     memset(&pPhrase->doclist, 0, sizeof(Fts3Doclist));

  166851.     for(i=0; i<pPhrase->nToken; i++){

  166852.       fts3SegReaderCursorFree(pPhrase->aToken[i].pSegcsr);

  166853.       pPhrase->aToken[i].pSegcsr = 0;

  166854.     }

  166855.   }

  166856. }

  166857. 

  166858. 

  166859. /*

  166860. ** Return SQLITE_CORRUPT_VTAB.

  166861. */

  166862. #ifdef SQLITE_DEBUG

  166863. SQLITE_PRIVATE int sqlite3Fts3Corrupt(){

  166864.   return SQLITE_CORRUPT_VTAB;

  166865. }

  166866. #endif

  166867. 

  166868. #if !SQLITE_CORE

  166869. /*

  166870. ** Initialize API pointer table, if required.

  166871. */

  166872. #ifdef _WIN32

  166873. __declspec(dllexport)

  166874. #endif

  166875. SQLITE_API int sqlite3_fts3_init(

  166876.   sqlite3 *db, 

  166877.   char **pzErrMsg,

  166878.   const sqlite3_api_routines *pApi

  166879. ){

  166880.   SQLITE_EXTENSION_INIT2(pApi)

  166881.   return sqlite3Fts3Init(db);

  166882. }

  166883. #endif

  166884. 

  166885. #endif

  166886. 

  166887. /************** End of fts3.c ************************************************/

  166888. /************** Begin file fts3_aux.c ****************************************/

  166889. /*

  166890. ** 2011 Jan 27

  166891. **

  166892. ** The author disclaims copyright to this source code.  In place of

  166893. ** a legal notice, here is a blessing:

  166894. **

  166895. **    May you do good and not evil.

  166896. **    May you find forgiveness for yourself and forgive others.

  166897. **    May you share freely, never taking more than you give.

  166898. **

  166899. ******************************************************************************

  166900. **

  166901. */

  166902. /* #include "fts3Int.h" */

  166903. #if !defined(SQLITE_CORE) || defined(SQLITE_ENABLE_FTS3)

  166904. 

  166905. /* #include <string.h> */

  166906. /* #include <assert.h> */

  166907. 

  166908. typedef struct Fts3auxTable Fts3auxTable;

  166909. typedef struct Fts3auxCursor Fts3auxCursor;

  166910. 

  166911. struct Fts3auxTable {

  166912.   sqlite3_vtab base;              /* Base class used by SQLite core */

  166913.   Fts3Table *pFts3Tab;

  166914. };

  166915. 

  166916. struct Fts3auxCursor {

  166917.   sqlite3_vtab_cursor base;       /* Base class used by SQLite core */

  166918.   Fts3MultiSegReader csr;        /* Must be right after "base" */

  166919.   Fts3SegFilter filter;

  166920.   char *zStop;

  166921.   int nStop;                      /* Byte-length of string zStop */

  166922.   int iLangid;                    /* Language id to query */

  166923.   int isEof;                      /* True if cursor is at EOF */

  166924.   sqlite3_int64 iRowid;           /* Current rowid */

  166925. 

  166926.   int iCol;                       /* Current value of 'col' column */

  166927.   int nStat;                      /* Size of aStat[] array */

  166928.   struct Fts3auxColstats {

  166929.     sqlite3_int64 nDoc;           /* 'documents' values for current csr row */

  166930.     sqlite3_int64 nOcc;           /* 'occurrences' values for current csr row */

  166931.   } *aStat;

  166932. };

  166933. 

  166934. /*

  166935. ** Schema of the terms table.

  166936. */

  166937. #define FTS3_AUX_SCHEMA \

  166938.   "CREATE TABLE x(term, col, documents, occurrences, languageid HIDDEN)"

  166939. 

  166940. /*

  166941. ** This function does all the work for both the xConnect and xCreate methods.

  166942. ** These tables have no persistent representation of their own, so xConnect

  166943. ** and xCreate are identical operations.

  166944. */

  166945. static int fts3auxConnectMethod(

  166946.   sqlite3 *db,                    /* Database connection */

  166947.   void *pUnused,                  /* Unused */

  166948.   int argc,                       /* Number of elements in argv array */

  166949.   const char * const *argv,       /* xCreate/xConnect argument array */

  166950.   sqlite3_vtab **ppVtab,          /* OUT: New sqlite3_vtab object */

  166951.   char **pzErr                    /* OUT: sqlite3_malloc'd error message */

  166952. ){

  166953.   char const *zDb;                /* Name of database (e.g. "main") */

  166954.   char const *zFts3;              /* Name of fts3 table */

  166955.   int nDb;                        /* Result of strlen(zDb) */

  166956.   int nFts3;                      /* Result of strlen(zFts3) */

  166957.   sqlite3_int64 nByte;            /* Bytes of space to allocate here */

  166958.   int rc;                         /* value returned by declare_vtab() */

  166959.   Fts3auxTable *p;                /* Virtual table object to return */

  166960. 

  166961.   UNUSED_PARAMETER(pUnused);

  166962. 

  166963.   /* The user should invoke this in one of two forms:

  166964.   **

  166965.   **     CREATE VIRTUAL TABLE xxx USING fts4aux(fts4-table);

  166966.   **     CREATE VIRTUAL TABLE xxx USING fts4aux(fts4-table-db, fts4-table);

  166967.   */

  166968.   if( argc!=4 && argc!=5 ) goto bad_args;

  166969. 

  166970.   zDb = argv[1]; 

  166971.   nDb = (int)strlen(zDb);

  166972.   if( argc==5 ){

  166973.     if( nDb==4 && 0==sqlite3_strnicmp("temp", zDb, 4) ){

  166974.       zDb = argv[3]; 

  166975.       nDb = (int)strlen(zDb);

  166976.       zFts3 = argv[4];

  166977.     }else{

  166978.       goto bad_args;

  166979.     }

  166980.   }else{

  166981.     zFts3 = argv[3];

  166982.   }

  166983.   nFts3 = (int)strlen(zFts3);

  166984. 

  166985.   rc = sqlite3_declare_vtab(db, FTS3_AUX_SCHEMA);

  166986.   if( rc!=SQLITE_OK ) return rc;

  166987. 

  166988.   nByte = sizeof(Fts3auxTable) + sizeof(Fts3Table) + nDb + nFts3 + 2;

  166989.   p = (Fts3auxTable *)sqlite3_malloc64(nByte);

  166990.   if( !p ) return SQLITE_NOMEM;

  166991.   memset(p, 0, nByte);

  166992. 

  166993.   p->pFts3Tab = (Fts3Table *)&p[1];

  166994.   p->pFts3Tab->zDb = (char *)&p->pFts3Tab[1];

  166995.   p->pFts3Tab->zName = &p->pFts3Tab->zDb[nDb+1];

  166996.   p->pFts3Tab->db = db;

  166997.   p->pFts3Tab->nIndex = 1;

  166998. 

  166999.   memcpy((char *)p->pFts3Tab->zDb, zDb, nDb);

  167000.   memcpy((char *)p->pFts3Tab->zName, zFts3, nFts3);

  167001.   sqlite3Fts3Dequote((char *)p->pFts3Tab->zName);

  167002. 

  167003.   *ppVtab = (sqlite3_vtab *)p;

  167004.   return SQLITE_OK;

  167005. 

  167006.  bad_args:

  167007.   sqlite3Fts3ErrMsg(pzErr, "invalid arguments to fts4aux constructor");

  167008.   return SQLITE_ERROR;

  167009. }

  167010. 

  167011. /*

  167012. ** This function does the work for both the xDisconnect and xDestroy methods.

  167013. ** These tables have no persistent representation of their own, so xDisconnect

  167014. ** and xDestroy are identical operations.

  167015. */

  167016. static int fts3auxDisconnectMethod(sqlite3_vtab *pVtab){

  167017.   Fts3auxTable *p = (Fts3auxTable *)pVtab;

  167018.   Fts3Table *pFts3 = p->pFts3Tab;

  167019.   int i;

  167020. 

  167021.   /* Free any prepared statements held */

  167022.   for(i=0; i<SizeofArray(pFts3->aStmt); i++){

  167023.     sqlite3_finalize(pFts3->aStmt[i]);

  167024.   }

  167025.   sqlite3_free(pFts3->zSegmentsTbl);

  167026.   sqlite3_free(p);

  167027.   return SQLITE_OK;

  167028. }

  167029. 

  167030. #define FTS4AUX_EQ_CONSTRAINT 1

  167031. #define FTS4AUX_GE_CONSTRAINT 2

  167032. #define FTS4AUX_LE_CONSTRAINT 4

  167033. 

  167034. /*

  167035. ** xBestIndex - Analyze a WHERE and ORDER BY clause.

  167036. */

  167037. static int fts3auxBestIndexMethod(

  167038.   sqlite3_vtab *pVTab, 

  167039.   sqlite3_index_info *pInfo

  167040. ){

  167041.   int i;

  167042.   int iEq = -1;

  167043.   int iGe = -1;

  167044.   int iLe = -1;

  167045.   int iLangid = -1;

  167046.   int iNext = 1;                  /* Next free argvIndex value */

  167047. 

  167048.   UNUSED_PARAMETER(pVTab);

  167049. 

  167050.   /* This vtab delivers always results in "ORDER BY term ASC" order. */

  167051.   if( pInfo->nOrderBy==1 

  167052.    && pInfo->aOrderBy[0].iColumn==0 

  167053.    && pInfo->aOrderBy[0].desc==0

  167054.   ){

  167055.     pInfo->orderByConsumed = 1;

  167056.   }

  167057. 

  167058.   /* Search for equality and range constraints on the "term" column. 

  167059.   ** And equality constraints on the hidden "languageid" column. */

  167060.   for(i=0; i<pInfo->nConstraint; i++){

  167061.     if( pInfo->aConstraint[i].usable ){

  167062.       int op = pInfo->aConstraint[i].op;

  167063.       int iCol = pInfo->aConstraint[i].iColumn;

  167064. 

  167065.       if( iCol==0 ){

  167066.         if( op==SQLITE_INDEX_CONSTRAINT_EQ ) iEq = i;

  167067.         if( op==SQLITE_INDEX_CONSTRAINT_LT ) iLe = i;

  167068.         if( op==SQLITE_INDEX_CONSTRAINT_LE ) iLe = i;

  167069.         if( op==SQLITE_INDEX_CONSTRAINT_GT ) iGe = i;

  167070.         if( op==SQLITE_INDEX_CONSTRAINT_GE ) iGe = i;

  167071.       }

  167072.       if( iCol==4 ){

  167073.         if( op==SQLITE_INDEX_CONSTRAINT_EQ ) iLangid = i;

  167074.       }

  167075.     }

  167076.   }

  167077. 

  167078.   if( iEq>=0 ){

  167079.     pInfo->idxNum = FTS4AUX_EQ_CONSTRAINT;

  167080.     pInfo->aConstraintUsage[iEq].argvIndex = iNext++;

  167081.     pInfo->estimatedCost = 5;

  167082.   }else{

  167083.     pInfo->idxNum = 0;

  167084.     pInfo->estimatedCost = 20000;

  167085.     if( iGe>=0 ){

  167086.       pInfo->idxNum += FTS4AUX_GE_CONSTRAINT;

  167087.       pInfo->aConstraintUsage[iGe].argvIndex = iNext++;

  167088.       pInfo->estimatedCost /= 2;

  167089.     }

  167090.     if( iLe>=0 ){

  167091.       pInfo->idxNum += FTS4AUX_LE_CONSTRAINT;

  167092.       pInfo->aConstraintUsage[iLe].argvIndex = iNext++;

  167093.       pInfo->estimatedCost /= 2;

  167094.     }

  167095.   }

  167096.   if( iLangid>=0 ){

  167097.     pInfo->aConstraintUsage[iLangid].argvIndex = iNext++;

  167098.     pInfo->estimatedCost--;

  167099.   }

  167100. 

  167101.   return SQLITE_OK;

  167102. }

  167103. 

  167104. /*

  167105. ** xOpen - Open a cursor.

  167106. */

  167107. static int fts3auxOpenMethod(sqlite3_vtab *pVTab, sqlite3_vtab_cursor **ppCsr){

  167108.   Fts3auxCursor *pCsr;            /* Pointer to cursor object to return */

  167109. 

  167110.   UNUSED_PARAMETER(pVTab);

  167111. 

  167112.   pCsr = (Fts3auxCursor *)sqlite3_malloc(sizeof(Fts3auxCursor));

  167113.   if( !pCsr ) return SQLITE_NOMEM;

  167114.   memset(pCsr, 0, sizeof(Fts3auxCursor));

  167115. 

  167116.   *ppCsr = (sqlite3_vtab_cursor *)pCsr;

  167117.   return SQLITE_OK;

  167118. }

  167119. 

  167120. /*

  167121. ** xClose - Close a cursor.

  167122. */

  167123. static int fts3auxCloseMethod(sqlite3_vtab_cursor *pCursor){

  167124.   Fts3Table *pFts3 = ((Fts3auxTable *)pCursor->pVtab)->pFts3Tab;

  167125.   Fts3auxCursor *pCsr = (Fts3auxCursor *)pCursor;

  167126. 

  167127.   sqlite3Fts3SegmentsClose(pFts3);

  167128.   sqlite3Fts3SegReaderFinish(&pCsr->csr);

  167129.   sqlite3_free((void *)pCsr->filter.zTerm);

  167130.   sqlite3_free(pCsr->zStop);

  167131.   sqlite3_free(pCsr->aStat);

  167132.   sqlite3_free(pCsr);

  167133.   return SQLITE_OK;

  167134. }

  167135. 

  167136. static int fts3auxGrowStatArray(Fts3auxCursor *pCsr, int nSize){

  167137.   if( nSize>pCsr->nStat ){

  167138.     struct Fts3auxColstats *aNew;

  167139.     aNew = (struct Fts3auxColstats *)sqlite3_realloc64(pCsr->aStat, 

  167140.         sizeof(struct Fts3auxColstats) * nSize

  167141.     );

  167142.     if( aNew==0 ) return SQLITE_NOMEM;

  167143.     memset(&aNew[pCsr->nStat], 0, 

  167144.         sizeof(struct Fts3auxColstats) * (nSize - pCsr->nStat)

  167145.     );

  167146.     pCsr->aStat = aNew;

  167147.     pCsr->nStat = nSize;

  167148.   }

  167149.   return SQLITE_OK;

  167150. }

  167151. 

  167152. /*

  167153. ** xNext - Advance the cursor to the next row, if any.

  167154. */

  167155. static int fts3auxNextMethod(sqlite3_vtab_cursor *pCursor){

  167156.   Fts3auxCursor *pCsr = (Fts3auxCursor *)pCursor;

  167157.   Fts3Table *pFts3 = ((Fts3auxTable *)pCursor->pVtab)->pFts3Tab;

  167158.   int rc;

  167159. 

  167160.   /* Increment our pretend rowid value. */

  167161.   pCsr->iRowid++;

  167162. 

  167163.   for(pCsr->iCol++; pCsr->iCol<pCsr->nStat; pCsr->iCol++){

  167164.     if( pCsr->aStat[pCsr->iCol].nDoc>0 ) return SQLITE_OK;

  167165.   }

  167166. 

  167167.   rc = sqlite3Fts3SegReaderStep(pFts3, &pCsr->csr);

  167168.   if( rc==SQLITE_ROW ){

  167169.     int i = 0;

  167170.     int nDoclist = pCsr->csr.nDoclist;

  167171.     char *aDoclist = pCsr->csr.aDoclist;

  167172.     int iCol;

  167173. 

  167174.     int eState = 0;

  167175. 

  167176.     if( pCsr->zStop ){

  167177.       int n = (pCsr->nStop<pCsr->csr.nTerm) ? pCsr->nStop : pCsr->csr.nTerm;

  167178.       int mc = memcmp(pCsr->zStop, pCsr->csr.zTerm, n);

  167179.       if( mc<0 || (mc==0 && pCsr->csr.nTerm>pCsr->nStop) ){

  167180.         pCsr->isEof = 1;

  167181.         return SQLITE_OK;

  167182.       }

  167183.     }

  167184. 

  167185.     if( fts3auxGrowStatArray(pCsr, 2) ) return SQLITE_NOMEM;

  167186.     memset(pCsr->aStat, 0, sizeof(struct Fts3auxColstats) * pCsr->nStat);

  167187.     iCol = 0;

  167188. 

  167189.     while( i<nDoclist ){

  167190.       sqlite3_int64 v = 0;

  167191. 

  167192.       i += sqlite3Fts3GetVarint(&aDoclist[i], &v);

  167193.       switch( eState ){

  167194.         /* State 0. In this state the integer just read was a docid. */

  167195.         case 0:

  167196.           pCsr->aStat[0].nDoc++;

  167197.           eState = 1;

  167198.           iCol = 0;

  167199.           break;

  167200. 

  167201.         /* State 1. In this state we are expecting either a 1, indicating

  167202.         ** that the following integer will be a column number, or the

  167203.         ** start of a position list for column 0.  

  167204.         ** 

  167205.         ** The only difference between state 1 and state 2 is that if the

  167206.         ** integer encountered in state 1 is not 0 or 1, then we need to

  167207.         ** increment the column 0 "nDoc" count for this term.

  167208.         */

  167209.         case 1:

  167210.           assert( iCol==0 );

  167211.           if( v>1 ){

  167212.             pCsr->aStat[1].nDoc++;

  167213.           }

  167214.           eState = 2;

  167215.           /* fall through */

  167216. 

  167217.         case 2:

  167218.           if( v==0 ){       /* 0x00. Next integer will be a docid. */

  167219.             eState = 0;

  167220.           }else if( v==1 ){ /* 0x01. Next integer will be a column number. */

  167221.             eState = 3;

  167222.           }else{            /* 2 or greater. A position. */

  167223.             pCsr->aStat[iCol+1].nOcc++;

  167224.             pCsr->aStat[0].nOcc++;

  167225.           }

  167226.           break;

  167227. 

  167228.         /* State 3. The integer just read is a column number. */

  167229.         default: assert( eState==3 );

  167230.           iCol = (int)v;

  167231.           if( fts3auxGrowStatArray(pCsr, iCol+2) ) return SQLITE_NOMEM;

  167232.           pCsr->aStat[iCol+1].nDoc++;

  167233.           eState = 2;

  167234.           break;

  167235.       }

  167236.     }

  167237. 

  167238.     pCsr->iCol = 0;

  167239.     rc = SQLITE_OK;

  167240.   }else{

  167241.     pCsr->isEof = 1;

  167242.   }

  167243.   return rc;

  167244. }

  167245. 

  167246. /*

  167247. ** xFilter - Initialize a cursor to point at the start of its data.

  167248. */

  167249. static int fts3auxFilterMethod(

  167250.   sqlite3_vtab_cursor *pCursor,   /* The cursor used for this query */

  167251.   int idxNum,                     /* Strategy index */

  167252.   const char *idxStr,             /* Unused */

  167253.   int nVal,                       /* Number of elements in apVal */

  167254.   sqlite3_value **apVal           /* Arguments for the indexing scheme */

  167255. ){

  167256.   Fts3auxCursor *pCsr = (Fts3auxCursor *)pCursor;

  167257.   Fts3Table *pFts3 = ((Fts3auxTable *)pCursor->pVtab)->pFts3Tab;

  167258.   int rc;

  167259.   int isScan = 0;

  167260.   int iLangVal = 0;               /* Language id to query */

  167261. 

  167262.   int iEq = -1;                   /* Index of term=? value in apVal */

  167263.   int iGe = -1;                   /* Index of term>=? value in apVal */

  167264.   int iLe = -1;                   /* Index of term<=? value in apVal */

  167265.   int iLangid = -1;               /* Index of languageid=? value in apVal */

  167266.   int iNext = 0;

  167267. 

  167268.   UNUSED_PARAMETER(nVal);

  167269.   UNUSED_PARAMETER(idxStr);

  167270. 

  167271.   assert( idxStr==0 );

  167272.   assert( idxNum==FTS4AUX_EQ_CONSTRAINT || idxNum==0

  167273.        || idxNum==FTS4AUX_LE_CONSTRAINT || idxNum==FTS4AUX_GE_CONSTRAINT

  167274.        || idxNum==(FTS4AUX_LE_CONSTRAINT|FTS4AUX_GE_CONSTRAINT)

  167275.   );

  167276. 

  167277.   if( idxNum==FTS4AUX_EQ_CONSTRAINT ){

  167278.     iEq = iNext++;

  167279.   }else{

  167280.     isScan = 1;

  167281.     if( idxNum & FTS4AUX_GE_CONSTRAINT ){

  167282.       iGe = iNext++;

  167283.     }

  167284.     if( idxNum & FTS4AUX_LE_CONSTRAINT ){

  167285.       iLe = iNext++;

  167286.     }

  167287.   }

  167288.   if( iNext<nVal ){

  167289.     iLangid = iNext++;

  167290.   }

  167291. 

  167292.   /* In case this cursor is being reused, close and zero it. */

  167293.   testcase(pCsr->filter.zTerm);

  167294.   sqlite3Fts3SegReaderFinish(&pCsr->csr);

  167295.   sqlite3_free((void *)pCsr->filter.zTerm);

  167296.   sqlite3_free(pCsr->aStat);

  167297.   memset(&pCsr->csr, 0, ((u8*)&pCsr[1]) - (u8*)&pCsr->csr);

  167298. 

  167299.   pCsr->filter.flags = FTS3_SEGMENT_REQUIRE_POS|FTS3_SEGMENT_IGNORE_EMPTY;

  167300.   if( isScan ) pCsr->filter.flags |= FTS3_SEGMENT_SCAN;

  167301. 

  167302.   if( iEq>=0 || iGe>=0 ){

  167303.     const unsigned char *zStr = sqlite3_value_text(apVal[0]);

  167304.     assert( (iEq==0 && iGe==-1) || (iEq==-1 && iGe==0) );

  167305.     if( zStr ){

  167306.       pCsr->filter.zTerm = sqlite3_mprintf("%s", zStr);

  167307.       if( pCsr->filter.zTerm==0 ) return SQLITE_NOMEM;

  167308.       pCsr->filter.nTerm = (int)strlen(pCsr->filter.zTerm);

  167309.     }

  167310.   }

  167311. 

  167312.   if( iLe>=0 ){

  167313.     pCsr->zStop = sqlite3_mprintf("%s", sqlite3_value_text(apVal[iLe]));

  167314.     if( pCsr->zStop==0 ) return SQLITE_NOMEM;

  167315.     pCsr->nStop = (int)strlen(pCsr->zStop);

  167316.   }

  167317.   

  167318.   if( iLangid>=0 ){

  167319.     iLangVal = sqlite3_value_int(apVal[iLangid]);

  167320. 

  167321.     /* If the user specified a negative value for the languageid, use zero

  167322.     ** instead. This works, as the "languageid=?" constraint will also

  167323.     ** be tested by the VDBE layer. The test will always be false (since

  167324.     ** this module will not return a row with a negative languageid), and

  167325.     ** so the overall query will return zero rows.  */

  167326.     if( iLangVal<0 ) iLangVal = 0;

  167327.   }

  167328.   pCsr->iLangid = iLangVal;

  167329. 

  167330.   rc = sqlite3Fts3SegReaderCursor(pFts3, iLangVal, 0, FTS3_SEGCURSOR_ALL,

  167331.       pCsr->filter.zTerm, pCsr->filter.nTerm, 0, isScan, &pCsr->csr

  167332.   );

  167333.   if( rc==SQLITE_OK ){

  167334.     rc = sqlite3Fts3SegReaderStart(pFts3, &pCsr->csr, &pCsr->filter);

  167335.   }

  167336. 

  167337.   if( rc==SQLITE_OK ) rc = fts3auxNextMethod(pCursor);

  167338.   return rc;

  167339. }

  167340. 

  167341. /*

  167342. ** xEof - Return true if the cursor is at EOF, or false otherwise.

  167343. */

  167344. static int fts3auxEofMethod(sqlite3_vtab_cursor *pCursor){

  167345.   Fts3auxCursor *pCsr = (Fts3auxCursor *)pCursor;

  167346.   return pCsr->isEof;

  167347. }

  167348. 

  167349. /*

  167350. ** xColumn - Return a column value.

  167351. */

  167352. static int fts3auxColumnMethod(

  167353.   sqlite3_vtab_cursor *pCursor,   /* Cursor to retrieve value from */

  167354.   sqlite3_context *pCtx,          /* Context for sqlite3_result_xxx() calls */

  167355.   int iCol                        /* Index of column to read value from */

  167356. ){

  167357.   Fts3auxCursor *p = (Fts3auxCursor *)pCursor;

  167358. 

  167359.   assert( p->isEof==0 );

  167360.   switch( iCol ){

  167361.     case 0: /* term */

  167362.       sqlite3_result_text(pCtx, p->csr.zTerm, p->csr.nTerm, SQLITE_TRANSIENT);

  167363.       break;

  167364. 

  167365.     case 1: /* col */

  167366.       if( p->iCol ){

  167367.         sqlite3_result_int(pCtx, p->iCol-1);

  167368.       }else{

  167369.         sqlite3_result_text(pCtx, "*", -1, SQLITE_STATIC);

  167370.       }

  167371.       break;

  167372. 

  167373.     case 2: /* documents */

  167374.       sqlite3_result_int64(pCtx, p->aStat[p->iCol].nDoc);

  167375.       break;

  167376. 

  167377.     case 3: /* occurrences */

  167378.       sqlite3_result_int64(pCtx, p->aStat[p->iCol].nOcc);

  167379.       break;

  167380. 

  167381.     default: /* languageid */

  167382.       assert( iCol==4 );

  167383.       sqlite3_result_int(pCtx, p->iLangid);

  167384.       break;

  167385.   }

  167386. 

  167387.   return SQLITE_OK;

  167388. }

  167389. 

  167390. /*

  167391. ** xRowid - Return the current rowid for the cursor.

  167392. */

  167393. static int fts3auxRowidMethod(

  167394.   sqlite3_vtab_cursor *pCursor,   /* Cursor to retrieve value from */

  167395.   sqlite_int64 *pRowid            /* OUT: Rowid value */

  167396. ){

  167397.   Fts3auxCursor *pCsr = (Fts3auxCursor *)pCursor;

  167398.   *pRowid = pCsr->iRowid;

  167399.   return SQLITE_OK;

  167400. }

  167401. 

  167402. /*

  167403. ** Register the fts3aux module with database connection db. Return SQLITE_OK

  167404. ** if successful or an error code if sqlite3_create_module() fails.

  167405. */

  167406. SQLITE_PRIVATE int sqlite3Fts3InitAux(sqlite3 *db){

  167407.   static const sqlite3_module fts3aux_module = {

  167408.      0,                           /* iVersion      */

  167409.      fts3auxConnectMethod,        /* xCreate       */

  167410.      fts3auxConnectMethod,        /* xConnect      */

  167411.      fts3auxBestIndexMethod,      /* xBestIndex    */

  167412.      fts3auxDisconnectMethod,     /* xDisconnect   */

  167413.      fts3auxDisconnectMethod,     /* xDestroy      */

  167414.      fts3auxOpenMethod,           /* xOpen         */

  167415.      fts3auxCloseMethod,          /* xClose        */

  167416.      fts3auxFilterMethod,         /* xFilter       */

  167417.      fts3auxNextMethod,           /* xNext         */

  167418.      fts3auxEofMethod,            /* xEof          */

  167419.      fts3auxColumnMethod,         /* xColumn       */

  167420.      fts3auxRowidMethod,          /* xRowid        */

  167421.      0,                           /* xUpdate       */

  167422.      0,                           /* xBegin        */

  167423.      0,                           /* xSync         */

  167424.      0,                           /* xCommit       */

  167425.      0,                           /* xRollback     */

  167426.      0,                           /* xFindFunction */

  167427.      0,                           /* xRename       */

  167428.      0,                           /* xSavepoint    */

  167429.      0,                           /* xRelease      */

  167430.      0,                           /* xRollbackTo   */

  167431.      0                            /* xShadowName   */

  167432.   };

  167433.   int rc;                         /* Return code */

  167434. 

  167435.   rc = sqlite3_create_module(db, "fts4aux", &fts3aux_module, 0);

  167436.   return rc;

  167437. }

  167438. 

  167439. #endif /* !defined(SQLITE_CORE) || defined(SQLITE_ENABLE_FTS3) */

  167440. 

  167441. /************** End of fts3_aux.c ********************************************/

  167442. /************** Begin file fts3_expr.c ***************************************/

  167443. /*

  167444. ** 2008 Nov 28

  167445. **

  167446. ** The author disclaims copyright to this source code.  In place of

  167447. ** a legal notice, here is a blessing:

  167448. **

  167449. **    May you do good and not evil.

  167450. **    May you find forgiveness for yourself and forgive others.

  167451. **    May you share freely, never taking more than you give.

  167452. **

  167453. ******************************************************************************

  167454. **

  167455. ** This module contains code that implements a parser for fts3 query strings

  167456. ** (the right-hand argument to the MATCH operator). Because the supported 

  167457. ** syntax is relatively simple, the whole tokenizer/parser system is

  167458. ** hand-coded. 

  167459. */

  167460. /* #include "fts3Int.h" */

  167461. #if !defined(SQLITE_CORE) || defined(SQLITE_ENABLE_FTS3)

  167462. 

  167463. /*

  167464. ** By default, this module parses the legacy syntax that has been 

  167465. ** traditionally used by fts3. Or, if SQLITE_ENABLE_FTS3_PARENTHESIS

  167466. ** is defined, then it uses the new syntax. The differences between

  167467. ** the new and the old syntaxes are:

  167468. **

  167469. **  a) The new syntax supports parenthesis. The old does not.

  167470. **

  167471. **  b) The new syntax supports the AND and NOT operators. The old does not.

  167472. **

  167473. **  c) The old syntax supports the "-" token qualifier. This is not 

  167474. **     supported by the new syntax (it is replaced by the NOT operator).

  167475. **

  167476. **  d) When using the old syntax, the OR operator has a greater precedence

  167477. **     than an implicit AND. When using the new, both implicity and explicit

  167478. **     AND operators have a higher precedence than OR.

  167479. **

  167480. ** If compiled with SQLITE_TEST defined, then this module exports the

  167481. ** symbol "int sqlite3_fts3_enable_parentheses". Setting this variable

  167482. ** to zero causes the module to use the old syntax. If it is set to 

  167483. ** non-zero the new syntax is activated. This is so both syntaxes can

  167484. ** be tested using a single build of testfixture.

  167485. **

  167486. ** The following describes the syntax supported by the fts3 MATCH

  167487. ** operator in a similar format to that used by the lemon parser

  167488. ** generator. This module does not use actually lemon, it uses a

  167489. ** custom parser.

  167490. **

  167491. **   query ::= andexpr (OR andexpr)*.

  167492. **

  167493. **   andexpr ::= notexpr (AND? notexpr)*.

  167494. **

  167495. **   notexpr ::= nearexpr (NOT nearexpr|-TOKEN)*.

  167496. **   notexpr ::= LP query RP.

  167497. **

  167498. **   nearexpr ::= phrase (NEAR distance_opt nearexpr)*.

  167499. **

  167500. **   distance_opt ::= .

  167501. **   distance_opt ::= / INTEGER.

  167502. **

  167503. **   phrase ::= TOKEN.

  167504. **   phrase ::= COLUMN:TOKEN.

  167505. **   phrase ::= "TOKEN TOKEN TOKEN...".

  167506. */

  167507. 

  167508. #ifdef SQLITE_TEST

  167509. SQLITE_API int sqlite3_fts3_enable_parentheses = 0;

  167510. #else

  167511. # ifdef SQLITE_ENABLE_FTS3_PARENTHESIS 

  167512. #  define sqlite3_fts3_enable_parentheses 1

  167513. # else

  167514. #  define sqlite3_fts3_enable_parentheses 0

  167515. # endif

  167516. #endif

  167517. 

  167518. /*

  167519. ** Default span for NEAR operators.

  167520. */

  167521. #define SQLITE_FTS3_DEFAULT_NEAR_PARAM 10

  167522. 

  167523. /* #include <string.h> */

  167524. /* #include <assert.h> */

  167525. 

  167526. /*

  167527. ** isNot:

  167528. **   This variable is used by function getNextNode(). When getNextNode() is

  167529. **   called, it sets ParseContext.isNot to true if the 'next node' is a 

  167530. **   FTSQUERY_PHRASE with a unary "-" attached to it. i.e. "mysql" in the

  167531. **   FTS3 query "sqlite -mysql". Otherwise, ParseContext.isNot is set to

  167532. **   zero.

  167533. */

  167534. typedef struct ParseContext ParseContext;

  167535. struct ParseContext {

  167536.   sqlite3_tokenizer *pTokenizer;      /* Tokenizer module */

  167537.   int iLangid;                        /* Language id used with tokenizer */

  167538.   const char **azCol;                 /* Array of column names for fts3 table */

  167539.   int bFts4;                          /* True to allow FTS4-only syntax */

  167540.   int nCol;                           /* Number of entries in azCol[] */

  167541.   int iDefaultCol;                    /* Default column to query */

  167542.   int isNot;                          /* True if getNextNode() sees a unary - */

  167543.   sqlite3_context *pCtx;              /* Write error message here */

  167544.   int nNest;                          /* Number of nested brackets */

  167545. };

  167546. 

  167547. /*

  167548. ** This function is equivalent to the standard isspace() function. 

  167549. **

  167550. ** The standard isspace() can be awkward to use safely, because although it

  167551. ** is defined to accept an argument of type int, its behavior when passed

  167552. ** an integer that falls outside of the range of the unsigned char type

  167553. ** is undefined (and sometimes, "undefined" means segfault). This wrapper

  167554. ** is defined to accept an argument of type char, and always returns 0 for

  167555. ** any values that fall outside of the range of the unsigned char type (i.e.

  167556. ** negative values).

  167557. */

  167558. static int fts3isspace(char c){

  167559.   return c==' ' || c=='\t' || c=='\n' || c=='\r' || c=='\v' || c=='\f';

  167560. }

  167561. 

  167562. /*

  167563. ** Allocate nByte bytes of memory using sqlite3_malloc(). If successful,

  167564. ** zero the memory before returning a pointer to it. If unsuccessful, 

  167565. ** return NULL.

  167566. */

  167567. static void *fts3MallocZero(sqlite3_int64 nByte){

  167568.   void *pRet = sqlite3_malloc64(nByte);

  167569.   if( pRet ) memset(pRet, 0, nByte);

  167570.   return pRet;

  167571. }

  167572. 

  167573. SQLITE_PRIVATE int sqlite3Fts3OpenTokenizer(

  167574.   sqlite3_tokenizer *pTokenizer,

  167575.   int iLangid,

  167576.   const char *z,

  167577.   int n,

  167578.   sqlite3_tokenizer_cursor **ppCsr

  167579. ){

  167580.   sqlite3_tokenizer_module const *pModule = pTokenizer->pModule;

  167581.   sqlite3_tokenizer_cursor *pCsr = 0;

  167582.   int rc;

  167583. 

  167584.   rc = pModule->xOpen(pTokenizer, z, n, &pCsr);

  167585.   assert( rc==SQLITE_OK || pCsr==0 );

  167586.   if( rc==SQLITE_OK ){

  167587.     pCsr->pTokenizer = pTokenizer;

  167588.     if( pModule->iVersion>=1 ){

  167589.       rc = pModule->xLanguageid(pCsr, iLangid);

  167590.       if( rc!=SQLITE_OK ){

  167591.         pModule->xClose(pCsr);

  167592.         pCsr = 0;

  167593.       }

  167594.     }

  167595.   }

  167596.   *ppCsr = pCsr;

  167597.   return rc;

  167598. }

  167599. 

  167600. /*

  167601. ** Function getNextNode(), which is called by fts3ExprParse(), may itself

  167602. ** call fts3ExprParse(). So this forward declaration is required.

  167603. */

  167604. static int fts3ExprParse(ParseContext *, const char *, int, Fts3Expr **, int *);

  167605. 

  167606. /*

  167607. ** Extract the next token from buffer z (length n) using the tokenizer

  167608. ** and other information (column names etc.) in pParse. Create an Fts3Expr

  167609. ** structure of type FTSQUERY_PHRASE containing a phrase consisting of this

  167610. ** single token and set *ppExpr to point to it. If the end of the buffer is

  167611. ** reached before a token is found, set *ppExpr to zero. It is the

  167612. ** responsibility of the caller to eventually deallocate the allocated 

  167613. ** Fts3Expr structure (if any) by passing it to sqlite3_free().

  167614. **

  167615. ** Return SQLITE_OK if successful, or SQLITE_NOMEM if a memory allocation

  167616. ** fails.

  167617. */

  167618. static int getNextToken(

  167619.   ParseContext *pParse,                   /* fts3 query parse context */

  167620.   int iCol,                               /* Value for Fts3Phrase.iColumn */

  167621.   const char *z, int n,                   /* Input string */

  167622.   Fts3Expr **ppExpr,                      /* OUT: expression */

  167623.   int *pnConsumed                         /* OUT: Number of bytes consumed */

  167624. ){

  167625.   sqlite3_tokenizer *pTokenizer = pParse->pTokenizer;

  167626.   sqlite3_tokenizer_module const *pModule = pTokenizer->pModule;

  167627.   int rc;

  167628.   sqlite3_tokenizer_cursor *pCursor;

  167629.   Fts3Expr *pRet = 0;

  167630.   int i = 0;

  167631. 

  167632.   /* Set variable i to the maximum number of bytes of input to tokenize. */

  167633.   for(i=0; i<n; i++){

  167634.     if( sqlite3_fts3_enable_parentheses && (z[i]=='(' || z[i]==')') ) break;

  167635.     if( z[i]=='"' ) break;

  167636.   }

  167637. 

  167638.   *pnConsumed = i;

  167639.   rc = sqlite3Fts3OpenTokenizer(pTokenizer, pParse->iLangid, z, i, &pCursor);

  167640.   if( rc==SQLITE_OK ){

  167641.     const char *zToken;

  167642.     int nToken = 0, iStart = 0, iEnd = 0, iPosition = 0;

  167643.     sqlite3_int64 nByte;                    /* total space to allocate */

  167644. 

  167645.     rc = pModule->xNext(pCursor, &zToken, &nToken, &iStart, &iEnd, &iPosition);

  167646.     if( rc==SQLITE_OK ){

  167647.       nByte = sizeof(Fts3Expr) + sizeof(Fts3Phrase) + nToken;

  167648.       pRet = (Fts3Expr *)fts3MallocZero(nByte);

  167649.       if( !pRet ){

  167650.         rc = SQLITE_NOMEM;

  167651.       }else{

  167652.         pRet->eType = FTSQUERY_PHRASE;

  167653.         pRet->pPhrase = (Fts3Phrase *)&pRet[1];

  167654.         pRet->pPhrase->nToken = 1;

  167655.         pRet->pPhrase->iColumn = iCol;

  167656.         pRet->pPhrase->aToken[0].n = nToken;

  167657.         pRet->pPhrase->aToken[0].z = (char *)&pRet->pPhrase[1];

  167658.         memcpy(pRet->pPhrase->aToken[0].z, zToken, nToken);

  167659. 

  167660.         if( iEnd<n && z[iEnd]=='*' ){

  167661.           pRet->pPhrase->aToken[0].isPrefix = 1;

  167662.           iEnd++;

  167663.         }

  167664. 

  167665.         while( 1 ){

  167666.           if( !sqlite3_fts3_enable_parentheses 

  167667.            && iStart>0 && z[iStart-1]=='-' 

  167668.           ){

  167669.             pParse->isNot = 1;

  167670.             iStart--;

  167671.           }else if( pParse->bFts4 && iStart>0 && z[iStart-1]=='^' ){

  167672.             pRet->pPhrase->aToken[0].bFirst = 1;

  167673.             iStart--;

  167674.           }else{

  167675.             break;

  167676.           }

  167677.         }

  167678. 

  167679.       }

  167680.       *pnConsumed = iEnd;

  167681.     }else if( i && rc==SQLITE_DONE ){

  167682.       rc = SQLITE_OK;

  167683.     }

  167684. 

  167685.     pModule->xClose(pCursor);

  167686.   }

  167687.   

  167688.   *ppExpr = pRet;

  167689.   return rc;

  167690. }

  167691. 

  167692. 

  167693. /*

  167694. ** Enlarge a memory allocation.  If an out-of-memory allocation occurs,

  167695. ** then free the old allocation.

  167696. */

  167697. static void *fts3ReallocOrFree(void *pOrig, sqlite3_int64 nNew){

  167698.   void *pRet = sqlite3_realloc64(pOrig, nNew);

  167699.   if( !pRet ){

  167700.     sqlite3_free(pOrig);

  167701.   }

  167702.   return pRet;

  167703. }

  167704. 

  167705. /*

  167706. ** Buffer zInput, length nInput, contains the contents of a quoted string

  167707. ** that appeared as part of an fts3 query expression. Neither quote character

  167708. ** is included in the buffer. This function attempts to tokenize the entire

  167709. ** input buffer and create an Fts3Expr structure of type FTSQUERY_PHRASE 

  167710. ** containing the results.

  167711. **

  167712. ** If successful, SQLITE_OK is returned and *ppExpr set to point at the

  167713. ** allocated Fts3Expr structure. Otherwise, either SQLITE_NOMEM (out of memory

  167714. ** error) or SQLITE_ERROR (tokenization error) is returned and *ppExpr set

  167715. ** to 0.

  167716. */

  167717. static int getNextString(

  167718.   ParseContext *pParse,                   /* fts3 query parse context */

  167719.   const char *zInput, int nInput,         /* Input string */

  167720.   Fts3Expr **ppExpr                       /* OUT: expression */

  167721. ){

  167722.   sqlite3_tokenizer *pTokenizer = pParse->pTokenizer;

  167723.   sqlite3_tokenizer_module const *pModule = pTokenizer->pModule;

  167724.   int rc;

  167725.   Fts3Expr *p = 0;

  167726.   sqlite3_tokenizer_cursor *pCursor = 0;

  167727.   char *zTemp = 0;

  167728.   int nTemp = 0;

  167729. 

  167730.   const int nSpace = sizeof(Fts3Expr) + sizeof(Fts3Phrase);

  167731.   int nToken = 0;

  167732. 

  167733.   /* The final Fts3Expr data structure, including the Fts3Phrase,

  167734.   ** Fts3PhraseToken structures token buffers are all stored as a single 

  167735.   ** allocation so that the expression can be freed with a single call to

  167736.   ** sqlite3_free(). Setting this up requires a two pass approach.

  167737.   **

  167738.   ** The first pass, in the block below, uses a tokenizer cursor to iterate

  167739.   ** through the tokens in the expression. This pass uses fts3ReallocOrFree()

  167740.   ** to assemble data in two dynamic buffers:

  167741.   **

  167742.   **   Buffer p: Points to the Fts3Expr structure, followed by the Fts3Phrase

  167743.   **             structure, followed by the array of Fts3PhraseToken 

  167744.   **             structures. This pass only populates the Fts3PhraseToken array.

  167745.   **

  167746.   **   Buffer zTemp: Contains copies of all tokens.

  167747.   **

  167748.   ** The second pass, in the block that begins "if( rc==SQLITE_DONE )" below,

  167749.   ** appends buffer zTemp to buffer p, and fills in the Fts3Expr and Fts3Phrase

  167750.   ** structures.

  167751.   */

  167752.   rc = sqlite3Fts3OpenTokenizer(

  167753.       pTokenizer, pParse->iLangid, zInput, nInput, &pCursor);

  167754.   if( rc==SQLITE_OK ){

  167755.     int ii;

  167756.     for(ii=0; rc==SQLITE_OK; ii++){

  167757.       const char *zByte;

  167758.       int nByte = 0, iBegin = 0, iEnd = 0, iPos = 0;

  167759.       rc = pModule->xNext(pCursor, &zByte, &nByte, &iBegin, &iEnd, &iPos);

  167760.       if( rc==SQLITE_OK ){

  167761.         Fts3PhraseToken *pToken;

  167762. 

  167763.         p = fts3ReallocOrFree(p, nSpace + ii*sizeof(Fts3PhraseToken));

  167764.         if( !p ) goto no_mem;

  167765. 

  167766.         zTemp = fts3ReallocOrFree(zTemp, nTemp + nByte);

  167767.         if( !zTemp ) goto no_mem;

  167768. 

  167769.         assert( nToken==ii );

  167770.         pToken = &((Fts3Phrase *)(&p[1]))->aToken[ii];

  167771.         memset(pToken, 0, sizeof(Fts3PhraseToken));

  167772. 

  167773.         memcpy(&zTemp[nTemp], zByte, nByte);

  167774.         nTemp += nByte;

  167775. 

  167776.         pToken->n = nByte;

  167777.         pToken->isPrefix = (iEnd<nInput && zInput[iEnd]=='*');

  167778.         pToken->bFirst = (iBegin>0 && zInput[iBegin-1]=='^');

  167779.         nToken = ii+1;

  167780.       }

  167781.     }

  167782. 

  167783.     pModule->xClose(pCursor);

  167784.     pCursor = 0;

  167785.   }

  167786. 

  167787.   if( rc==SQLITE_DONE ){

  167788.     int jj;

  167789.     char *zBuf = 0;

  167790. 

  167791.     p = fts3ReallocOrFree(p, nSpace + nToken*sizeof(Fts3PhraseToken) + nTemp);

  167792.     if( !p ) goto no_mem;

  167793.     memset(p, 0, (char *)&(((Fts3Phrase *)&p[1])->aToken[0])-(char *)p);

  167794.     p->eType = FTSQUERY_PHRASE;

  167795.     p->pPhrase = (Fts3Phrase *)&p[1];

  167796.     p->pPhrase->iColumn = pParse->iDefaultCol;

  167797.     p->pPhrase->nToken = nToken;

  167798. 

  167799.     zBuf = (char *)&p->pPhrase->aToken[nToken];

  167800.     if( zTemp ){

  167801.       memcpy(zBuf, zTemp, nTemp);

  167802.       sqlite3_free(zTemp);

  167803.     }else{

  167804.       assert( nTemp==0 );

  167805.     }

  167806. 

  167807.     for(jj=0; jj<p->pPhrase->nToken; jj++){

  167808.       p->pPhrase->aToken[jj].z = zBuf;

  167809.       zBuf += p->pPhrase->aToken[jj].n;

  167810.     }

  167811.     rc = SQLITE_OK;

  167812.   }

  167813. 

  167814.   *ppExpr = p;

  167815.   return rc;

  167816. no_mem:

  167817. 

  167818.   if( pCursor ){

  167819.     pModule->xClose(pCursor);

  167820.   }

  167821.   sqlite3_free(zTemp);

  167822.   sqlite3_free(p);

  167823.   *ppExpr = 0;

  167824.   return SQLITE_NOMEM;

  167825. }

  167826. 

  167827. /*

  167828. ** The output variable *ppExpr is populated with an allocated Fts3Expr 

  167829. ** structure, or set to 0 if the end of the input buffer is reached.

  167830. **

  167831. ** Returns an SQLite error code. SQLITE_OK if everything works, SQLITE_NOMEM

  167832. ** if a malloc failure occurs, or SQLITE_ERROR if a parse error is encountered.

  167833. ** If SQLITE_ERROR is returned, pContext is populated with an error message.

  167834. */

  167835. static int getNextNode(

  167836.   ParseContext *pParse,                   /* fts3 query parse context */

  167837.   const char *z, int n,                   /* Input string */

  167838.   Fts3Expr **ppExpr,                      /* OUT: expression */

  167839.   int *pnConsumed                         /* OUT: Number of bytes consumed */

  167840. ){

  167841.   static const struct Fts3Keyword {

  167842.     char *z;                              /* Keyword text */

  167843.     unsigned char n;                      /* Length of the keyword */

  167844.     unsigned char parenOnly;              /* Only valid in paren mode */

  167845.     unsigned char eType;                  /* Keyword code */

  167846.   } aKeyword[] = {

  167847.     { "OR" ,  2, 0, FTSQUERY_OR   },

  167848.     { "AND",  3, 1, FTSQUERY_AND  },

  167849.     { "NOT",  3, 1, FTSQUERY_NOT  },

  167850.     { "NEAR", 4, 0, FTSQUERY_NEAR }

  167851.   };

  167852.   int ii;

  167853.   int iCol;

  167854.   int iColLen;

  167855.   int rc;

  167856.   Fts3Expr *pRet = 0;

  167857. 

  167858.   const char *zInput = z;

  167859.   int nInput = n;

  167860. 

  167861.   pParse->isNot = 0;

  167862. 

  167863.   /* Skip over any whitespace before checking for a keyword, an open or

  167864.   ** close bracket, or a quoted string. 

  167865.   */

  167866.   while( nInput>0 && fts3isspace(*zInput) ){

  167867.     nInput--;

  167868.     zInput++;

  167869.   }

  167870.   if( nInput==0 ){

  167871.     return SQLITE_DONE;

  167872.   }

  167873. 

  167874.   /* See if we are dealing with a keyword. */

  167875.   for(ii=0; ii<(int)(sizeof(aKeyword)/sizeof(struct Fts3Keyword)); ii++){

  167876.     const struct Fts3Keyword *pKey = &aKeyword[ii];

  167877. 

  167878.     if( (pKey->parenOnly & ~sqlite3_fts3_enable_parentheses)!=0 ){

  167879.       continue;

  167880.     }

  167881. 

  167882.     if( nInput>=pKey->n && 0==memcmp(zInput, pKey->z, pKey->n) ){

  167883.       int nNear = SQLITE_FTS3_DEFAULT_NEAR_PARAM;

  167884.       int nKey = pKey->n;

  167885.       char cNext;

  167886. 

  167887.       /* If this is a "NEAR" keyword, check for an explicit nearness. */

  167888.       if( pKey->eType==FTSQUERY_NEAR ){

  167889.         assert( nKey==4 );

  167890.         if( zInput[4]=='/' && zInput[5]>='0' && zInput[5]<='9' ){

  167891.           nNear = 0;

  167892.           for(nKey=5; zInput[nKey]>='0' && zInput[nKey]<='9'; nKey++){

  167893.             nNear = nNear * 10 + (zInput[nKey] - '0');

  167894.           }

  167895.         }

  167896.       }

  167897. 

  167898.       /* At this point this is probably a keyword. But for that to be true,

  167899.       ** the next byte must contain either whitespace, an open or close

  167900.       ** parenthesis, a quote character, or EOF. 

  167901.       */

  167902.       cNext = zInput[nKey];

  167903.       if( fts3isspace(cNext) 

  167904.        || cNext=='"' || cNext=='(' || cNext==')' || cNext==0

  167905.       ){

  167906.         pRet = (Fts3Expr *)fts3MallocZero(sizeof(Fts3Expr));

  167907.         if( !pRet ){

  167908.           return SQLITE_NOMEM;

  167909.         }

  167910.         pRet->eType = pKey->eType;

  167911.         pRet->nNear = nNear;

  167912.         *ppExpr = pRet;

  167913.         *pnConsumed = (int)((zInput - z) + nKey);

  167914.         return SQLITE_OK;

  167915.       }

  167916. 

  167917.       /* Turns out that wasn't a keyword after all. This happens if the

  167918.       ** user has supplied a token such as "ORacle". Continue.

  167919.       */

  167920.     }

  167921.   }

  167922. 

  167923.   /* See if we are dealing with a quoted phrase. If this is the case, then

  167924.   ** search for the closing quote and pass the whole string to getNextString()

  167925.   ** for processing. This is easy to do, as fts3 has no syntax for escaping

  167926.   ** a quote character embedded in a string.

  167927.   */

  167928.   if( *zInput=='"' ){

  167929.     for(ii=1; ii<nInput && zInput[ii]!='"'; ii++);

  167930.     *pnConsumed = (int)((zInput - z) + ii + 1);

  167931.     if( ii==nInput ){

  167932.       return SQLITE_ERROR;

  167933.     }

  167934.     return getNextString(pParse, &zInput[1], ii-1, ppExpr);

  167935.   }

  167936. 

  167937.   if( sqlite3_fts3_enable_parentheses ){

  167938.     if( *zInput=='(' ){

  167939.       int nConsumed = 0;

  167940.       pParse->nNest++;

  167941.       rc = fts3ExprParse(pParse, zInput+1, nInput-1, ppExpr, &nConsumed);

  167942.       *pnConsumed = (int)(zInput - z) + 1 + nConsumed;

  167943.       return rc;

  167944.     }else if( *zInput==')' ){

  167945.       pParse->nNest--;

  167946.       *pnConsumed = (int)((zInput - z) + 1);

  167947.       *ppExpr = 0;

  167948.       return SQLITE_DONE;

  167949.     }

  167950.   }

  167951. 

  167952.   /* If control flows to this point, this must be a regular token, or 

  167953.   ** the end of the input. Read a regular token using the sqlite3_tokenizer

  167954.   ** interface. Before doing so, figure out if there is an explicit

  167955.   ** column specifier for the token. 

  167956.   **

  167957.   ** TODO: Strangely, it is not possible to associate a column specifier

  167958.   ** with a quoted phrase, only with a single token. Not sure if this was

  167959.   ** an implementation artifact or an intentional decision when fts3 was

  167960.   ** first implemented. Whichever it was, this module duplicates the 

  167961.   ** limitation.

  167962.   */

  167963.   iCol = pParse->iDefaultCol;

  167964.   iColLen = 0;

  167965.   for(ii=0; ii<pParse->nCol; ii++){

  167966.     const char *zStr = pParse->azCol[ii];

  167967.     int nStr = (int)strlen(zStr);

  167968.     if( nInput>nStr && zInput[nStr]==':' 

  167969.      && sqlite3_strnicmp(zStr, zInput, nStr)==0 

  167970.     ){

  167971.       iCol = ii;

  167972.       iColLen = (int)((zInput - z) + nStr + 1);

  167973.       break;

  167974.     }

  167975.   }

  167976.   rc = getNextToken(pParse, iCol, &z[iColLen], n-iColLen, ppExpr, pnConsumed);

  167977.   *pnConsumed += iColLen;

  167978.   return rc;

  167979. }

  167980. 

  167981. /*

  167982. ** The argument is an Fts3Expr structure for a binary operator (any type

  167983. ** except an FTSQUERY_PHRASE). Return an integer value representing the

  167984. ** precedence of the operator. Lower values have a higher precedence (i.e.

  167985. ** group more tightly). For example, in the C language, the == operator

  167986. ** groups more tightly than ||, and would therefore have a higher precedence.

  167987. **

  167988. ** When using the new fts3 query syntax (when SQLITE_ENABLE_FTS3_PARENTHESIS

  167989. ** is defined), the order of the operators in precedence from highest to

  167990. ** lowest is:

  167991. **

  167992. **   NEAR

  167993. **   NOT

  167994. **   AND (including implicit ANDs)

  167995. **   OR

  167996. **

  167997. ** Note that when using the old query syntax, the OR operator has a higher

  167998. ** precedence than the AND operator.

  167999. */

  168000. static int opPrecedence(Fts3Expr *p){

  168001.   assert( p->eType!=FTSQUERY_PHRASE );

  168002.   if( sqlite3_fts3_enable_parentheses ){

  168003.     return p->eType;

  168004.   }else if( p->eType==FTSQUERY_NEAR ){

  168005.     return 1;

  168006.   }else if( p->eType==FTSQUERY_OR ){

  168007.     return 2;

  168008.   }

  168009.   assert( p->eType==FTSQUERY_AND );

  168010.   return 3;

  168011. }

  168012. 

  168013. /*

  168014. ** Argument ppHead contains a pointer to the current head of a query 

  168015. ** expression tree being parsed. pPrev is the expression node most recently

  168016. ** inserted into the tree. This function adds pNew, which is always a binary

  168017. ** operator node, into the expression tree based on the relative precedence

  168018. ** of pNew and the existing nodes of the tree. This may result in the head

  168019. ** of the tree changing, in which case *ppHead is set to the new root node.

  168020. */

  168021. static void insertBinaryOperator(

  168022.   Fts3Expr **ppHead,       /* Pointer to the root node of a tree */

  168023.   Fts3Expr *pPrev,         /* Node most recently inserted into the tree */

  168024.   Fts3Expr *pNew           /* New binary node to insert into expression tree */

  168025. ){

  168026.   Fts3Expr *pSplit = pPrev;

  168027.   while( pSplit->pParent && opPrecedence(pSplit->pParent)<=opPrecedence(pNew) ){

  168028.     pSplit = pSplit->pParent;

  168029.   }

  168030. 

  168031.   if( pSplit->pParent ){

  168032.     assert( pSplit->pParent->pRight==pSplit );

  168033.     pSplit->pParent->pRight = pNew;

  168034.     pNew->pParent = pSplit->pParent;

  168035.   }else{

  168036.     *ppHead = pNew;

  168037.   }

  168038.   pNew->pLeft = pSplit;

  168039.   pSplit->pParent = pNew;

  168040. }

  168041. 

  168042. /*

  168043. ** Parse the fts3 query expression found in buffer z, length n. This function

  168044. ** returns either when the end of the buffer is reached or an unmatched 

  168045. ** closing bracket - ')' - is encountered.

  168046. **

  168047. ** If successful, SQLITE_OK is returned, *ppExpr is set to point to the

  168048. ** parsed form of the expression and *pnConsumed is set to the number of

  168049. ** bytes read from buffer z. Otherwise, *ppExpr is set to 0 and SQLITE_NOMEM

  168050. ** (out of memory error) or SQLITE_ERROR (parse error) is returned.

  168051. */

  168052. static int fts3ExprParse(

  168053.   ParseContext *pParse,                   /* fts3 query parse context */

  168054.   const char *z, int n,                   /* Text of MATCH query */

  168055.   Fts3Expr **ppExpr,                      /* OUT: Parsed query structure */

  168056.   int *pnConsumed                         /* OUT: Number of bytes consumed */

  168057. ){

  168058.   Fts3Expr *pRet = 0;

  168059.   Fts3Expr *pPrev = 0;

  168060.   Fts3Expr *pNotBranch = 0;               /* Only used in legacy parse mode */

  168061.   int nIn = n;

  168062.   const char *zIn = z;

  168063.   int rc = SQLITE_OK;

  168064.   int isRequirePhrase = 1;

  168065. 

  168066.   while( rc==SQLITE_OK ){

  168067.     Fts3Expr *p = 0;

  168068.     int nByte = 0;

  168069. 

  168070.     rc = getNextNode(pParse, zIn, nIn, &p, &nByte);

  168071.     assert( nByte>0 || (rc!=SQLITE_OK && p==0) );

  168072.     if( rc==SQLITE_OK ){

  168073.       if( p ){

  168074.         int isPhrase;

  168075. 

  168076.         if( !sqlite3_fts3_enable_parentheses 

  168077.             && p->eType==FTSQUERY_PHRASE && pParse->isNot 

  168078.         ){

  168079.           /* Create an implicit NOT operator. */

  168080.           Fts3Expr *pNot = fts3MallocZero(sizeof(Fts3Expr));

  168081.           if( !pNot ){

  168082.             sqlite3Fts3ExprFree(p);

  168083.             rc = SQLITE_NOMEM;

  168084.             goto exprparse_out;

  168085.           }

  168086.           pNot->eType = FTSQUERY_NOT;

  168087.           pNot->pRight = p;

  168088.           p->pParent = pNot;

  168089.           if( pNotBranch ){

  168090.             pNot->pLeft = pNotBranch;

  168091.             pNotBranch->pParent = pNot;

  168092.           }

  168093.           pNotBranch = pNot;

  168094.           p = pPrev;

  168095.         }else{

  168096.           int eType = p->eType;

  168097.           isPhrase = (eType==FTSQUERY_PHRASE || p->pLeft);

  168098. 

  168099.           /* The isRequirePhrase variable is set to true if a phrase or

  168100.           ** an expression contained in parenthesis is required. If a

  168101.           ** binary operator (AND, OR, NOT or NEAR) is encounted when

  168102.           ** isRequirePhrase is set, this is a syntax error.

  168103.           */

  168104.           if( !isPhrase && isRequirePhrase ){

  168105.             sqlite3Fts3ExprFree(p);

  168106.             rc = SQLITE_ERROR;

  168107.             goto exprparse_out;

  168108.           }

  168109. 

  168110.           if( isPhrase && !isRequirePhrase ){

  168111.             /* Insert an implicit AND operator. */

  168112.             Fts3Expr *pAnd;

  168113.             assert( pRet && pPrev );

  168114.             pAnd = fts3MallocZero(sizeof(Fts3Expr));

  168115.             if( !pAnd ){

  168116.               sqlite3Fts3ExprFree(p);

  168117.               rc = SQLITE_NOMEM;

  168118.               goto exprparse_out;

  168119.             }

  168120.             pAnd->eType = FTSQUERY_AND;

  168121.             insertBinaryOperator(&pRet, pPrev, pAnd);

  168122.             pPrev = pAnd;

  168123.           }

  168124. 

  168125.           /* This test catches attempts to make either operand of a NEAR

  168126.            ** operator something other than a phrase. For example, either of

  168127.            ** the following:

  168128.            **

  168129.            **    (bracketed expression) NEAR phrase

  168130.            **    phrase NEAR (bracketed expression)

  168131.            **

  168132.            ** Return an error in either case.

  168133.            */

  168134.           if( pPrev && (

  168135.             (eType==FTSQUERY_NEAR && !isPhrase && pPrev->eType!=FTSQUERY_PHRASE)

  168136.          || (eType!=FTSQUERY_PHRASE && isPhrase && pPrev->eType==FTSQUERY_NEAR)

  168137.           )){

  168138.             sqlite3Fts3ExprFree(p);

  168139.             rc = SQLITE_ERROR;

  168140.             goto exprparse_out;

  168141.           }

  168142. 

  168143.           if( isPhrase ){

  168144.             if( pRet ){

  168145.               assert( pPrev && pPrev->pLeft && pPrev->pRight==0 );

  168146.               pPrev->pRight = p;

  168147.               p->pParent = pPrev;

  168148.             }else{

  168149.               pRet = p;

  168150.             }

  168151.           }else{

  168152.             insertBinaryOperator(&pRet, pPrev, p);

  168153.           }

  168154.           isRequirePhrase = !isPhrase;

  168155.         }

  168156.         pPrev = p;

  168157.       }

  168158.       assert( nByte>0 );

  168159.     }

  168160.     assert( rc!=SQLITE_OK || (nByte>0 && nByte<=nIn) );

  168161.     nIn -= nByte;

  168162.     zIn += nByte;

  168163.   }

  168164. 

  168165.   if( rc==SQLITE_DONE && pRet && isRequirePhrase ){

  168166.     rc = SQLITE_ERROR;

  168167.   }

  168168. 

  168169.   if( rc==SQLITE_DONE ){

  168170.     rc = SQLITE_OK;

  168171.     if( !sqlite3_fts3_enable_parentheses && pNotBranch ){

  168172.       if( !pRet ){

  168173.         rc = SQLITE_ERROR;

  168174.       }else{

  168175.         Fts3Expr *pIter = pNotBranch;

  168176.         while( pIter->pLeft ){

  168177.           pIter = pIter->pLeft;

  168178.         }

  168179.         pIter->pLeft = pRet;

  168180.         pRet->pParent = pIter;

  168181.         pRet = pNotBranch;

  168182.       }

  168183.     }

  168184.   }

  168185.   *pnConsumed = n - nIn;

  168186. 

  168187. exprparse_out:

  168188.   if( rc!=SQLITE_OK ){

  168189.     sqlite3Fts3ExprFree(pRet);

  168190.     sqlite3Fts3ExprFree(pNotBranch);

  168191.     pRet = 0;

  168192.   }

  168193.   *ppExpr = pRet;

  168194.   return rc;

  168195. }

  168196. 

  168197. /*

  168198. ** Return SQLITE_ERROR if the maximum depth of the expression tree passed 

  168199. ** as the only argument is more than nMaxDepth.

  168200. */

  168201. static int fts3ExprCheckDepth(Fts3Expr *p, int nMaxDepth){

  168202.   int rc = SQLITE_OK;

  168203.   if( p ){

  168204.     if( nMaxDepth<0 ){ 

  168205.       rc = SQLITE_TOOBIG;

  168206.     }else{

  168207.       rc = fts3ExprCheckDepth(p->pLeft, nMaxDepth-1);

  168208.       if( rc==SQLITE_OK ){

  168209.         rc = fts3ExprCheckDepth(p->pRight, nMaxDepth-1);

  168210.       }

  168211.     }

  168212.   }

  168213.   return rc;

  168214. }

  168215. 

  168216. /*

  168217. ** This function attempts to transform the expression tree at (*pp) to

  168218. ** an equivalent but more balanced form. The tree is modified in place.

  168219. ** If successful, SQLITE_OK is returned and (*pp) set to point to the 

  168220. ** new root expression node. 

  168221. **

  168222. ** nMaxDepth is the maximum allowable depth of the balanced sub-tree.

  168223. **

  168224. ** Otherwise, if an error occurs, an SQLite error code is returned and 

  168225. ** expression (*pp) freed.

  168226. */

  168227. static int fts3ExprBalance(Fts3Expr **pp, int nMaxDepth){

  168228.   int rc = SQLITE_OK;             /* Return code */

  168229.   Fts3Expr *pRoot = *pp;          /* Initial root node */

  168230.   Fts3Expr *pFree = 0;            /* List of free nodes. Linked by pParent. */

  168231.   int eType = pRoot->eType;       /* Type of node in this tree */

  168232. 

  168233.   if( nMaxDepth==0 ){

  168234.     rc = SQLITE_ERROR;

  168235.   }

  168236. 

  168237.   if( rc==SQLITE_OK ){

  168238.     if( (eType==FTSQUERY_AND || eType==FTSQUERY_OR) ){

  168239.       Fts3Expr **apLeaf;

  168240.       apLeaf = (Fts3Expr **)sqlite3_malloc64(sizeof(Fts3Expr *) * nMaxDepth);

  168241.       if( 0==apLeaf ){

  168242.         rc = SQLITE_NOMEM;

  168243.       }else{

  168244.         memset(apLeaf, 0, sizeof(Fts3Expr *) * nMaxDepth);

  168245.       }

  168246. 

  168247.       if( rc==SQLITE_OK ){

  168248.         int i;

  168249.         Fts3Expr *p;

  168250. 

  168251.         /* Set $p to point to the left-most leaf in the tree of eType nodes. */

  168252.         for(p=pRoot; p->eType==eType; p=p->pLeft){

  168253.           assert( p->pParent==0 || p->pParent->pLeft==p );

  168254.           assert( p->pLeft && p->pRight );

  168255.         }

  168256. 

  168257.         /* This loop runs once for each leaf in the tree of eType nodes. */

  168258.         while( 1 ){

  168259.           int iLvl;

  168260.           Fts3Expr *pParent = p->pParent;     /* Current parent of p */

  168261. 

  168262.           assert( pParent==0 || pParent->pLeft==p );

  168263.           p->pParent = 0;

  168264.           if( pParent ){

  168265.             pParent->pLeft = 0;

  168266.           }else{

  168267.             pRoot = 0;

  168268.           }

  168269.           rc = fts3ExprBalance(&p, nMaxDepth-1);

  168270.           if( rc!=SQLITE_OK ) break;

  168271. 

  168272.           for(iLvl=0; p && iLvl<nMaxDepth; iLvl++){

  168273.             if( apLeaf[iLvl]==0 ){

  168274.               apLeaf[iLvl] = p;

  168275.               p = 0;

  168276.             }else{

  168277.               assert( pFree );

  168278.               pFree->pLeft = apLeaf[iLvl];

  168279.               pFree->pRight = p;

  168280.               pFree->pLeft->pParent = pFree;

  168281.               pFree->pRight->pParent = pFree;

  168282. 

  168283.               p = pFree;

  168284.               pFree = pFree->pParent;

  168285.               p->pParent = 0;

  168286.               apLeaf[iLvl] = 0;

  168287.             }

  168288.           }

  168289.           if( p ){

  168290.             sqlite3Fts3ExprFree(p);

  168291.             rc = SQLITE_TOOBIG;

  168292.             break;

  168293.           }

  168294. 

  168295.           /* If that was the last leaf node, break out of the loop */

  168296.           if( pParent==0 ) break;

  168297. 

  168298.           /* Set $p to point to the next leaf in the tree of eType nodes */

  168299.           for(p=pParent->pRight; p->eType==eType; p=p->pLeft);

  168300. 

  168301.           /* Remove pParent from the original tree. */

  168302.           assert( pParent->pParent==0 || pParent->pParent->pLeft==pParent );

  168303.           pParent->pRight->pParent = pParent->pParent;

  168304.           if( pParent->pParent ){

  168305.             pParent->pParent->pLeft = pParent->pRight;

  168306.           }else{

  168307.             assert( pParent==pRoot );

  168308.             pRoot = pParent->pRight;

  168309.           }

  168310. 

  168311.           /* Link pParent into the free node list. It will be used as an

  168312.           ** internal node of the new tree.  */

  168313.           pParent->pParent = pFree;

  168314.           pFree = pParent;

  168315.         }

  168316. 

  168317.         if( rc==SQLITE_OK ){

  168318.           p = 0;

  168319.           for(i=0; i<nMaxDepth; i++){

  168320.             if( apLeaf[i] ){

  168321.               if( p==0 ){

  168322.                 p = apLeaf[i];

  168323.                 p->pParent = 0;

  168324.               }else{

  168325.                 assert( pFree!=0 );

  168326.                 pFree->pRight = p;

  168327.                 pFree->pLeft = apLeaf[i];

  168328.                 pFree->pLeft->pParent = pFree;

  168329.                 pFree->pRight->pParent = pFree;

  168330. 

  168331.                 p = pFree;

  168332.                 pFree = pFree->pParent;

  168333.                 p->pParent = 0;

  168334.               }

  168335.             }

  168336.           }

  168337.           pRoot = p;

  168338.         }else{

  168339.           /* An error occurred. Delete the contents of the apLeaf[] array 

  168340.           ** and pFree list. Everything else is cleaned up by the call to

  168341.           ** sqlite3Fts3ExprFree(pRoot) below.  */

  168342.           Fts3Expr *pDel;

  168343.           for(i=0; i<nMaxDepth; i++){

  168344.             sqlite3Fts3ExprFree(apLeaf[i]);

  168345.           }

  168346.           while( (pDel=pFree)!=0 ){

  168347.             pFree = pDel->pParent;

  168348.             sqlite3_free(pDel);

  168349.           }

  168350.         }

  168351. 

  168352.         assert( pFree==0 );

  168353.         sqlite3_free( apLeaf );

  168354.       }

  168355.     }else if( eType==FTSQUERY_NOT ){

  168356.       Fts3Expr *pLeft = pRoot->pLeft;

  168357.       Fts3Expr *pRight = pRoot->pRight;

  168358. 

  168359.       pRoot->pLeft = 0;

  168360.       pRoot->pRight = 0;

  168361.       pLeft->pParent = 0;

  168362.       pRight->pParent = 0;

  168363. 

  168364.       rc = fts3ExprBalance(&pLeft, nMaxDepth-1);

  168365.       if( rc==SQLITE_OK ){

  168366.         rc = fts3ExprBalance(&pRight, nMaxDepth-1);

  168367.       }

  168368. 

  168369.       if( rc!=SQLITE_OK ){

  168370.         sqlite3Fts3ExprFree(pRight);

  168371.         sqlite3Fts3ExprFree(pLeft);

  168372.       }else{

  168373.         assert( pLeft && pRight );

  168374.         pRoot->pLeft = pLeft;

  168375.         pLeft->pParent = pRoot;

  168376.         pRoot->pRight = pRight;

  168377.         pRight->pParent = pRoot;

  168378.       }

  168379.     }

  168380.   }

  168381.   

  168382.   if( rc!=SQLITE_OK ){

  168383.     sqlite3Fts3ExprFree(pRoot);

  168384.     pRoot = 0;

  168385.   }

  168386.   *pp = pRoot;

  168387.   return rc;

  168388. }

  168389. 

  168390. /*

  168391. ** This function is similar to sqlite3Fts3ExprParse(), with the following

  168392. ** differences:

  168393. **

  168394. **   1. It does not do expression rebalancing.

  168395. **   2. It does not check that the expression does not exceed the 

  168396. **      maximum allowable depth.

  168397. **   3. Even if it fails, *ppExpr may still be set to point to an 

  168398. **      expression tree. It should be deleted using sqlite3Fts3ExprFree()

  168399. **      in this case.

  168400. */

  168401. static int fts3ExprParseUnbalanced(

  168402.   sqlite3_tokenizer *pTokenizer,      /* Tokenizer module */

  168403.   int iLangid,                        /* Language id for tokenizer */

  168404.   char **azCol,                       /* Array of column names for fts3 table */

  168405.   int bFts4,                          /* True to allow FTS4-only syntax */

  168406.   int nCol,                           /* Number of entries in azCol[] */

  168407.   int iDefaultCol,                    /* Default column to query */

  168408.   const char *z, int n,               /* Text of MATCH query */

  168409.   Fts3Expr **ppExpr                   /* OUT: Parsed query structure */

  168410. ){

  168411.   int nParsed;

  168412.   int rc;

  168413.   ParseContext sParse;

  168414. 

  168415.   memset(&sParse, 0, sizeof(ParseContext));

  168416.   sParse.pTokenizer = pTokenizer;

  168417.   sParse.iLangid = iLangid;

  168418.   sParse.azCol = (const char **)azCol;

  168419.   sParse.nCol = nCol;

  168420.   sParse.iDefaultCol = iDefaultCol;

  168421.   sParse.bFts4 = bFts4;

  168422.   if( z==0 ){

  168423.     *ppExpr = 0;

  168424.     return SQLITE_OK;

  168425.   }

  168426.   if( n<0 ){

  168427.     n = (int)strlen(z);

  168428.   }

  168429.   rc = fts3ExprParse(&sParse, z, n, ppExpr, &nParsed);

  168430.   assert( rc==SQLITE_OK || *ppExpr==0 );

  168431. 

  168432.   /* Check for mismatched parenthesis */

  168433.   if( rc==SQLITE_OK && sParse.nNest ){

  168434.     rc = SQLITE_ERROR;

  168435.   }

  168436.   

  168437.   return rc;

  168438. }

  168439. 

  168440. /*

  168441. ** Parameters z and n contain a pointer to and length of a buffer containing

  168442. ** an fts3 query expression, respectively. This function attempts to parse the

  168443. ** query expression and create a tree of Fts3Expr structures representing the

  168444. ** parsed expression. If successful, *ppExpr is set to point to the head

  168445. ** of the parsed expression tree and SQLITE_OK is returned. If an error

  168446. ** occurs, either SQLITE_NOMEM (out-of-memory error) or SQLITE_ERROR (parse

  168447. ** error) is returned and *ppExpr is set to 0.

  168448. **

  168449. ** If parameter n is a negative number, then z is assumed to point to a

  168450. ** nul-terminated string and the length is determined using strlen().

  168451. **

  168452. ** The first parameter, pTokenizer, is passed the fts3 tokenizer module to

  168453. ** use to normalize query tokens while parsing the expression. The azCol[]

  168454. ** array, which is assumed to contain nCol entries, should contain the names

  168455. ** of each column in the target fts3 table, in order from left to right. 

  168456. ** Column names must be nul-terminated strings.

  168457. **

  168458. ** The iDefaultCol parameter should be passed the index of the table column

  168459. ** that appears on the left-hand-side of the MATCH operator (the default

  168460. ** column to match against for tokens for which a column name is not explicitly

  168461. ** specified as part of the query string), or -1 if tokens may by default

  168462. ** match any table column.

  168463. */

  168464. SQLITE_PRIVATE int sqlite3Fts3ExprParse(

  168465.   sqlite3_tokenizer *pTokenizer,      /* Tokenizer module */

  168466.   int iLangid,                        /* Language id for tokenizer */

  168467.   char **azCol,                       /* Array of column names for fts3 table */

  168468.   int bFts4,                          /* True to allow FTS4-only syntax */

  168469.   int nCol,                           /* Number of entries in azCol[] */

  168470.   int iDefaultCol,                    /* Default column to query */

  168471.   const char *z, int n,               /* Text of MATCH query */

  168472.   Fts3Expr **ppExpr,                  /* OUT: Parsed query structure */

  168473.   char **pzErr                        /* OUT: Error message (sqlite3_malloc) */

  168474. ){

  168475.   int rc = fts3ExprParseUnbalanced(

  168476.       pTokenizer, iLangid, azCol, bFts4, nCol, iDefaultCol, z, n, ppExpr

  168477.   );

  168478.   

  168479.   /* Rebalance the expression. And check that its depth does not exceed

  168480.   ** SQLITE_FTS3_MAX_EXPR_DEPTH.  */

  168481.   if( rc==SQLITE_OK && *ppExpr ){

  168482.     rc = fts3ExprBalance(ppExpr, SQLITE_FTS3_MAX_EXPR_DEPTH);

  168483.     if( rc==SQLITE_OK ){

  168484.       rc = fts3ExprCheckDepth(*ppExpr, SQLITE_FTS3_MAX_EXPR_DEPTH);

  168485.     }

  168486.   }

  168487. 

  168488.   if( rc!=SQLITE_OK ){

  168489.     sqlite3Fts3ExprFree(*ppExpr);

  168490.     *ppExpr = 0;

  168491.     if( rc==SQLITE_TOOBIG ){

  168492.       sqlite3Fts3ErrMsg(pzErr,

  168493.           "FTS expression tree is too large (maximum depth %d)", 

  168494.           SQLITE_FTS3_MAX_EXPR_DEPTH

  168495.       );

  168496.       rc = SQLITE_ERROR;

  168497.     }else if( rc==SQLITE_ERROR ){

  168498.       sqlite3Fts3ErrMsg(pzErr, "malformed MATCH expression: [%s]", z);

  168499.     }

  168500.   }

  168501. 

  168502.   return rc;

  168503. }

  168504. 

  168505. /*

  168506. ** Free a single node of an expression tree.

  168507. */

  168508. static void fts3FreeExprNode(Fts3Expr *p){

  168509.   assert( p->eType==FTSQUERY_PHRASE || p->pPhrase==0 );

  168510.   sqlite3Fts3EvalPhraseCleanup(p->pPhrase);

  168511.   sqlite3_free(p->aMI);

  168512.   sqlite3_free(p);

  168513. }

  168514. 

  168515. /*

  168516. ** Free a parsed fts3 query expression allocated by sqlite3Fts3ExprParse().

  168517. **

  168518. ** This function would be simpler if it recursively called itself. But

  168519. ** that would mean passing a sufficiently large expression to ExprParse()

  168520. ** could cause a stack overflow.

  168521. */

  168522. SQLITE_PRIVATE void sqlite3Fts3ExprFree(Fts3Expr *pDel){

  168523.   Fts3Expr *p;

  168524.   assert( pDel==0 || pDel->pParent==0 );

  168525.   for(p=pDel; p && (p->pLeft||p->pRight); p=(p->pLeft ? p->pLeft : p->pRight)){

  168526.     assert( p->pParent==0 || p==p->pParent->pRight || p==p->pParent->pLeft );

  168527.   }

  168528.   while( p ){

  168529.     Fts3Expr *pParent = p->pParent;

  168530.     fts3FreeExprNode(p);

  168531.     if( pParent && p==pParent->pLeft && pParent->pRight ){

  168532.       p = pParent->pRight;

  168533.       while( p && (p->pLeft || p->pRight) ){

  168534.         assert( p==p->pParent->pRight || p==p->pParent->pLeft );

  168535.         p = (p->pLeft ? p->pLeft : p->pRight);

  168536.       }

  168537.     }else{

  168538.       p = pParent;

  168539.     }

  168540.   }

  168541. }

  168542. 

  168543. /****************************************************************************

  168544. *****************************************************************************

  168545. ** Everything after this point is just test code.

  168546. */

  168547. 

  168548. #ifdef SQLITE_TEST

  168549. 

  168550. /* #include <stdio.h> */

  168551. 

  168552. /*

  168553. ** Return a pointer to a buffer containing a text representation of the

  168554. ** expression passed as the first argument. The buffer is obtained from

  168555. ** sqlite3_malloc(). It is the responsibility of the caller to use 

  168556. ** sqlite3_free() to release the memory. If an OOM condition is encountered,

  168557. ** NULL is returned.

  168558. **

  168559. ** If the second argument is not NULL, then its contents are prepended to 

  168560. ** the returned expression text and then freed using sqlite3_free().

  168561. */

  168562. static char *exprToString(Fts3Expr *pExpr, char *zBuf){

  168563.   if( pExpr==0 ){

  168564.     return sqlite3_mprintf("");

  168565.   }

  168566.   switch( pExpr->eType ){

  168567.     case FTSQUERY_PHRASE: {

  168568.       Fts3Phrase *pPhrase = pExpr->pPhrase;

  168569.       int i;

  168570.       zBuf = sqlite3_mprintf(

  168571.           "%zPHRASE %d 0", zBuf, pPhrase->iColumn);

  168572.       for(i=0; zBuf && i<pPhrase->nToken; i++){

  168573.         zBuf = sqlite3_mprintf("%z %.*s%s", zBuf, 

  168574.             pPhrase->aToken[i].n, pPhrase->aToken[i].z,

  168575.             (pPhrase->aToken[i].isPrefix?"+":"")

  168576.         );

  168577.       }

  168578.       return zBuf;

  168579.     }

  168580. 

  168581.     case FTSQUERY_NEAR:

  168582.       zBuf = sqlite3_mprintf("%zNEAR/%d ", zBuf, pExpr->nNear);

  168583.       break;

  168584.     case FTSQUERY_NOT:

  168585.       zBuf = sqlite3_mprintf("%zNOT ", zBuf);

  168586.       break;

  168587.     case FTSQUERY_AND:

  168588.       zBuf = sqlite3_mprintf("%zAND ", zBuf);

  168589.       break;

  168590.     case FTSQUERY_OR:

  168591.       zBuf = sqlite3_mprintf("%zOR ", zBuf);

  168592.       break;

  168593.   }

  168594. 

  168595.   if( zBuf ) zBuf = sqlite3_mprintf("%z{", zBuf);

  168596.   if( zBuf ) zBuf = exprToString(pExpr->pLeft, zBuf);

  168597.   if( zBuf ) zBuf = sqlite3_mprintf("%z} {", zBuf);

  168598. 

  168599.   if( zBuf ) zBuf = exprToString(pExpr->pRight, zBuf);

  168600.   if( zBuf ) zBuf = sqlite3_mprintf("%z}", zBuf);

  168601. 

  168602.   return zBuf;

  168603. }

  168604. 

  168605. /*

  168606. ** This is the implementation of a scalar SQL function used to test the 

  168607. ** expression parser. It should be called as follows:

  168608. **

  168609. **   fts3_exprtest(<tokenizer>, <expr>, <column 1>, ...);

  168610. **

  168611. ** The first argument, <tokenizer>, is the name of the fts3 tokenizer used

  168612. ** to parse the query expression (see README.tokenizers). The second argument

  168613. ** is the query expression to parse. Each subsequent argument is the name

  168614. ** of a column of the fts3 table that the query expression may refer to.

  168615. ** For example:

  168616. **

  168617. **   SELECT fts3_exprtest('simple', 'Bill col2:Bloggs', 'col1', 'col2');

  168618. */

  168619. static void fts3ExprTestCommon(

  168620.   int bRebalance,

  168621.   sqlite3_context *context,

  168622.   int argc,

  168623.   sqlite3_value **argv

  168624. ){

  168625.   sqlite3_tokenizer *pTokenizer = 0;

  168626.   int rc;

  168627.   char **azCol = 0;

  168628.   const char *zExpr;

  168629.   int nExpr;

  168630.   int nCol;

  168631.   int ii;

  168632.   Fts3Expr *pExpr;

  168633.   char *zBuf = 0;

  168634.   Fts3Hash *pHash = (Fts3Hash*)sqlite3_user_data(context);

  168635.   const char *zTokenizer = 0;

  168636.   char *zErr = 0;

  168637. 

  168638.   if( argc<3 ){

  168639.     sqlite3_result_error(context, 

  168640.         "Usage: fts3_exprtest(tokenizer, expr, col1, ...", -1

  168641.     );

  168642.     return;

  168643.   }

  168644. 

  168645.   zTokenizer = (const char*)sqlite3_value_text(argv[0]);

  168646.   rc = sqlite3Fts3InitTokenizer(pHash, zTokenizer, &pTokenizer, &zErr);

  168647.   if( rc!=SQLITE_OK ){

  168648.     if( rc==SQLITE_NOMEM ){

  168649.       sqlite3_result_error_nomem(context);

  168650.     }else{

  168651.       sqlite3_result_error(context, zErr, -1);

  168652.     }

  168653.     sqlite3_free(zErr);

  168654.     return;

  168655.   }

  168656. 

  168657.   zExpr = (const char *)sqlite3_value_text(argv[1]);

  168658.   nExpr = sqlite3_value_bytes(argv[1]);

  168659.   nCol = argc-2;

  168660.   azCol = (char **)sqlite3_malloc64(nCol*sizeof(char *));

  168661.   if( !azCol ){

  168662.     sqlite3_result_error_nomem(context);

  168663.     goto exprtest_out;

  168664.   }

  168665.   for(ii=0; ii<nCol; ii++){

  168666.     azCol[ii] = (char *)sqlite3_value_text(argv[ii+2]);

  168667.   }

  168668. 

  168669.   if( bRebalance ){

  168670.     char *zDummy = 0;

  168671.     rc = sqlite3Fts3ExprParse(

  168672.         pTokenizer, 0, azCol, 0, nCol, nCol, zExpr, nExpr, &pExpr, &zDummy

  168673.     );

  168674.     assert( rc==SQLITE_OK || pExpr==0 );

  168675.     sqlite3_free(zDummy);

  168676.   }else{

  168677.     rc = fts3ExprParseUnbalanced(

  168678.         pTokenizer, 0, azCol, 0, nCol, nCol, zExpr, nExpr, &pExpr

  168679.     );

  168680.   }

  168681. 

  168682.   if( rc!=SQLITE_OK && rc!=SQLITE_NOMEM ){

  168683.     sqlite3Fts3ExprFree(pExpr);

  168684.     sqlite3_result_error(context, "Error parsing expression", -1);

  168685.   }else if( rc==SQLITE_NOMEM || !(zBuf = exprToString(pExpr, 0)) ){

  168686.     sqlite3_result_error_nomem(context);

  168687.   }else{

  168688.     sqlite3_result_text(context, zBuf, -1, SQLITE_TRANSIENT);

  168689.     sqlite3_free(zBuf);

  168690.   }

  168691. 

  168692.   sqlite3Fts3ExprFree(pExpr);

  168693. 

  168694. exprtest_out:

  168695.   if( pTokenizer ){

  168696.     rc = pTokenizer->pModule->xDestroy(pTokenizer);

  168697.   }

  168698.   sqlite3_free(azCol);

  168699. }

  168700. 

  168701. static void fts3ExprTest(

  168702.   sqlite3_context *context,

  168703.   int argc,

  168704.   sqlite3_value **argv

  168705. ){

  168706.   fts3ExprTestCommon(0, context, argc, argv);

  168707. }

  168708. static void fts3ExprTestRebalance(

  168709.   sqlite3_context *context,

  168710.   int argc,

  168711.   sqlite3_value **argv

  168712. ){

  168713.   fts3ExprTestCommon(1, context, argc, argv);

  168714. }

  168715. 

  168716. /*

  168717. ** Register the query expression parser test function fts3_exprtest() 

  168718. ** with database connection db. 

  168719. */

  168720. SQLITE_PRIVATE int sqlite3Fts3ExprInitTestInterface(sqlite3 *db, Fts3Hash *pHash){

  168721.   int rc = sqlite3_create_function(

  168722.       db, "fts3_exprtest", -1, SQLITE_UTF8, (void*)pHash, fts3ExprTest, 0, 0

  168723.   );

  168724.   if( rc==SQLITE_OK ){

  168725.     rc = sqlite3_create_function(db, "fts3_exprtest_rebalance", 

  168726.         -1, SQLITE_UTF8, (void*)pHash, fts3ExprTestRebalance, 0, 0

  168727.     );

  168728.   }

  168729.   return rc;

  168730. }

  168731. 

  168732. #endif

  168733. #endif /* !defined(SQLITE_CORE) || defined(SQLITE_ENABLE_FTS3) */

  168734. 

  168735. /************** End of fts3_expr.c *******************************************/

  168736. /************** Begin file fts3_hash.c ***************************************/

  168737. /*

  168738. ** 2001 September 22

  168739. **

  168740. ** The author disclaims copyright to this source code.  In place of

  168741. ** a legal notice, here is a blessing:

  168742. **

  168743. **    May you do good and not evil.

  168744. **    May you find forgiveness for yourself and forgive others.

  168745. **    May you share freely, never taking more than you give.

  168746. **

  168747. *************************************************************************

  168748. ** This is the implementation of generic hash-tables used in SQLite.

  168749. ** We've modified it slightly to serve as a standalone hash table

  168750. ** implementation for the full-text indexing module.

  168751. */

  168752. 

  168753. /*

  168754. ** The code in this file is only compiled if:

  168755. **

  168756. **     * The FTS3 module is being built as an extension

  168757. **       (in which case SQLITE_CORE is not defined), or

  168758. **

  168759. **     * The FTS3 module is being built into the core of

  168760. **       SQLite (in which case SQLITE_ENABLE_FTS3 is defined).

  168761. */

  168762. /* #include "fts3Int.h" */

  168763. #if !defined(SQLITE_CORE) || defined(SQLITE_ENABLE_FTS3)

  168764. 

  168765. /* #include <assert.h> */

  168766. /* #include <stdlib.h> */

  168767. /* #include <string.h> */

  168768. 

  168769. /* #include "fts3_hash.h" */

  168770. 

  168771. /*

  168772. ** Malloc and Free functions

  168773. */

  168774. static void *fts3HashMalloc(sqlite3_int64 n){

  168775.   void *p = sqlite3_malloc64(n);

  168776.   if( p ){

  168777.     memset(p, 0, n);

  168778.   }

  168779.   return p;

  168780. }

  168781. static void fts3HashFree(void *p){

  168782.   sqlite3_free(p);

  168783. }

  168784. 

  168785. /* Turn bulk memory into a hash table object by initializing the

  168786. ** fields of the Hash structure.

  168787. **

  168788. ** "pNew" is a pointer to the hash table that is to be initialized.

  168789. ** keyClass is one of the constants 

  168790. ** FTS3_HASH_BINARY or FTS3_HASH_STRING.  The value of keyClass 

  168791. ** determines what kind of key the hash table will use.  "copyKey" is

  168792. ** true if the hash table should make its own private copy of keys and

  168793. ** false if it should just use the supplied pointer.

  168794. */

  168795. SQLITE_PRIVATE void sqlite3Fts3HashInit(Fts3Hash *pNew, char keyClass, char copyKey){

  168796.   assert( pNew!=0 );

  168797.   assert( keyClass>=FTS3_HASH_STRING && keyClass<=FTS3_HASH_BINARY );

  168798.   pNew->keyClass = keyClass;

  168799.   pNew->copyKey = copyKey;

  168800.   pNew->first = 0;

  168801.   pNew->count = 0;

  168802.   pNew->htsize = 0;

  168803.   pNew->ht = 0;

  168804. }

  168805. 

  168806. /* Remove all entries from a hash table.  Reclaim all memory.

  168807. ** Call this routine to delete a hash table or to reset a hash table

  168808. ** to the empty state.

  168809. */

  168810. SQLITE_PRIVATE void sqlite3Fts3HashClear(Fts3Hash *pH){

  168811.   Fts3HashElem *elem;         /* For looping over all elements of the table */

  168812. 

  168813.   assert( pH!=0 );

  168814.   elem = pH->first;

  168815.   pH->first = 0;

  168816.   fts3HashFree(pH->ht);

  168817.   pH->ht = 0;

  168818.   pH->htsize = 0;

  168819.   while( elem ){

  168820.     Fts3HashElem *next_elem = elem->next;

  168821.     if( pH->copyKey && elem->pKey ){

  168822.       fts3HashFree(elem->pKey);

  168823.     }

  168824.     fts3HashFree(elem);

  168825.     elem = next_elem;

  168826.   }

  168827.   pH->count = 0;

  168828. }

  168829. 

  168830. /*

  168831. ** Hash and comparison functions when the mode is FTS3_HASH_STRING

  168832. */

  168833. static int fts3StrHash(const void *pKey, int nKey){

  168834.   const char *z = (const char *)pKey;

  168835.   unsigned h = 0;

  168836.   if( nKey<=0 ) nKey = (int) strlen(z);

  168837.   while( nKey > 0  ){

  168838.     h = (h<<3) ^ h ^ *z++;

  168839.     nKey--;

  168840.   }

  168841.   return (int)(h & 0x7fffffff);

  168842. }

  168843. static int fts3StrCompare(const void *pKey1, int n1, const void *pKey2, int n2){

  168844.   if( n1!=n2 ) return 1;

  168845.   return strncmp((const char*)pKey1,(const char*)pKey2,n1);

  168846. }

  168847. 

  168848. /*

  168849. ** Hash and comparison functions when the mode is FTS3_HASH_BINARY

  168850. */

  168851. static int fts3BinHash(const void *pKey, int nKey){

  168852.   int h = 0;

  168853.   const char *z = (const char *)pKey;

  168854.   while( nKey-- > 0 ){

  168855.     h = (h<<3) ^ h ^ *(z++);

  168856.   }

  168857.   return h & 0x7fffffff;

  168858. }

  168859. static int fts3BinCompare(const void *pKey1, int n1, const void *pKey2, int n2){

  168860.   if( n1!=n2 ) return 1;

  168861.   return memcmp(pKey1,pKey2,n1);

  168862. }

  168863. 

  168864. /*

  168865. ** Return a pointer to the appropriate hash function given the key class.

  168866. **

  168867. ** The C syntax in this function definition may be unfamilar to some 

  168868. ** programmers, so we provide the following additional explanation:

  168869. **

  168870. ** The name of the function is "ftsHashFunction".  The function takes a

  168871. ** single parameter "keyClass".  The return value of ftsHashFunction()

  168872. ** is a pointer to another function.  Specifically, the return value

  168873. ** of ftsHashFunction() is a pointer to a function that takes two parameters

  168874. ** with types "const void*" and "int" and returns an "int".

  168875. */

  168876. static int (*ftsHashFunction(int keyClass))(const void*,int){

  168877.   if( keyClass==FTS3_HASH_STRING ){

  168878.     return &fts3StrHash;

  168879.   }else{

  168880.     assert( keyClass==FTS3_HASH_BINARY );

  168881.     return &fts3BinHash;

  168882.   }

  168883. }

  168884. 

  168885. /*

  168886. ** Return a pointer to the appropriate hash function given the key class.

  168887. **

  168888. ** For help in interpreted the obscure C code in the function definition,

  168889. ** see the header comment on the previous function.

  168890. */

  168891. static int (*ftsCompareFunction(int keyClass))(const void*,int,const void*,int){

  168892.   if( keyClass==FTS3_HASH_STRING ){

  168893.     return &fts3StrCompare;

  168894.   }else{

  168895.     assert( keyClass==FTS3_HASH_BINARY );

  168896.     return &fts3BinCompare;

  168897.   }

  168898. }

  168899. 

  168900. /* Link an element into the hash table

  168901. */

  168902. static void fts3HashInsertElement(

  168903.   Fts3Hash *pH,            /* The complete hash table */

  168904.   struct _fts3ht *pEntry,  /* The entry into which pNew is inserted */

  168905.   Fts3HashElem *pNew       /* The element to be inserted */

  168906. ){

  168907.   Fts3HashElem *pHead;     /* First element already in pEntry */

  168908.   pHead = pEntry->chain;

  168909.   if( pHead ){

  168910.     pNew->next = pHead;

  168911.     pNew->prev = pHead->prev;

  168912.     if( pHead->prev ){ pHead->prev->next = pNew; }

  168913.     else             { pH->first = pNew; }

  168914.     pHead->prev = pNew;

  168915.   }else{

  168916.     pNew->next = pH->first;

  168917.     if( pH->first ){ pH->first->prev = pNew; }

  168918.     pNew->prev = 0;

  168919.     pH->first = pNew;

  168920.   }

  168921.   pEntry->count++;

  168922.   pEntry->chain = pNew;

  168923. }

  168924. 

  168925. 

  168926. /* Resize the hash table so that it cantains "new_size" buckets.

  168927. ** "new_size" must be a power of 2.  The hash table might fail 

  168928. ** to resize if sqliteMalloc() fails.

  168929. **

  168930. ** Return non-zero if a memory allocation error occurs.

  168931. */

  168932. static int fts3Rehash(Fts3Hash *pH, int new_size){

  168933.   struct _fts3ht *new_ht;          /* The new hash table */

  168934.   Fts3HashElem *elem, *next_elem;  /* For looping over existing elements */

  168935.   int (*xHash)(const void*,int);   /* The hash function */

  168936. 

  168937.   assert( (new_size & (new_size-1))==0 );

  168938.   new_ht = (struct _fts3ht *)fts3HashMalloc( new_size*sizeof(struct _fts3ht) );

  168939.   if( new_ht==0 ) return 1;

  168940.   fts3HashFree(pH->ht);

  168941.   pH->ht = new_ht;

  168942.   pH->htsize = new_size;

  168943.   xHash = ftsHashFunction(pH->keyClass);

  168944.   for(elem=pH->first, pH->first=0; elem; elem = next_elem){

  168945.     int h = (*xHash)(elem->pKey, elem->nKey) & (new_size-1);

  168946.     next_elem = elem->next;

  168947.     fts3HashInsertElement(pH, &new_ht[h], elem);

  168948.   }

  168949.   return 0;

  168950. }

  168951. 

  168952. /* This function (for internal use only) locates an element in an

  168953. ** hash table that matches the given key.  The hash for this key has

  168954. ** already been computed and is passed as the 4th parameter.

  168955. */

  168956. static Fts3HashElem *fts3FindElementByHash(

  168957.   const Fts3Hash *pH, /* The pH to be searched */

  168958.   const void *pKey,   /* The key we are searching for */

  168959.   int nKey,

  168960.   int h               /* The hash for this key. */

  168961. ){

  168962.   Fts3HashElem *elem;            /* Used to loop thru the element list */

  168963.   int count;                     /* Number of elements left to test */

  168964.   int (*xCompare)(const void*,int,const void*,int);  /* comparison function */

  168965. 

  168966.   if( pH->ht ){

  168967.     struct _fts3ht *pEntry = &pH->ht[h];

  168968.     elem = pEntry->chain;

  168969.     count = pEntry->count;

  168970.     xCompare = ftsCompareFunction(pH->keyClass);

  168971.     while( count-- && elem ){

  168972.       if( (*xCompare)(elem->pKey,elem->nKey,pKey,nKey)==0 ){ 

  168973.         return elem;

  168974.       }

  168975.       elem = elem->next;

  168976.     }

  168977.   }

  168978.   return 0;

  168979. }

  168980. 

  168981. /* Remove a single entry from the hash table given a pointer to that

  168982. ** element and a hash on the element's key.

  168983. */

  168984. static void fts3RemoveElementByHash(

  168985.   Fts3Hash *pH,         /* The pH containing "elem" */

  168986.   Fts3HashElem* elem,   /* The element to be removed from the pH */

  168987.   int h                 /* Hash value for the element */

  168988. ){

  168989.   struct _fts3ht *pEntry;

  168990.   if( elem->prev ){

  168991.     elem->prev->next = elem->next; 

  168992.   }else{

  168993.     pH->first = elem->next;

  168994.   }

  168995.   if( elem->next ){

  168996.     elem->next->prev = elem->prev;

  168997.   }

  168998.   pEntry = &pH->ht[h];

  168999.   if( pEntry->chain==elem ){

  169000.     pEntry->chain = elem->next;

  169001.   }

  169002.   pEntry->count--;

  169003.   if( pEntry->count<=0 ){

  169004.     pEntry->chain = 0;

  169005.   }

  169006.   if( pH->copyKey && elem->pKey ){

  169007.     fts3HashFree(elem->pKey);

  169008.   }

  169009.   fts3HashFree( elem );

  169010.   pH->count--;

  169011.   if( pH->count<=0 ){

  169012.     assert( pH->first==0 );

  169013.     assert( pH->count==0 );

  169014.     fts3HashClear(pH);

  169015.   }

  169016. }

  169017. 

  169018. SQLITE_PRIVATE Fts3HashElem *sqlite3Fts3HashFindElem(

  169019.   const Fts3Hash *pH, 

  169020.   const void *pKey, 

  169021.   int nKey

  169022. ){

  169023.   int h;                          /* A hash on key */

  169024.   int (*xHash)(const void*,int);  /* The hash function */

  169025. 

  169026.   if( pH==0 || pH->ht==0 ) return 0;

  169027.   xHash = ftsHashFunction(pH->keyClass);

  169028.   assert( xHash!=0 );

  169029.   h = (*xHash)(pKey,nKey);

  169030.   assert( (pH->htsize & (pH->htsize-1))==0 );

  169031.   return fts3FindElementByHash(pH,pKey,nKey, h & (pH->htsize-1));

  169032. }

  169033. 

  169034. /* 

  169035. ** Attempt to locate an element of the hash table pH with a key

  169036. ** that matches pKey,nKey.  Return the data for this element if it is

  169037. ** found, or NULL if there is no match.

  169038. */

  169039. SQLITE_PRIVATE void *sqlite3Fts3HashFind(const Fts3Hash *pH, const void *pKey, int nKey){

  169040.   Fts3HashElem *pElem;            /* The element that matches key (if any) */

  169041. 

  169042.   pElem = sqlite3Fts3HashFindElem(pH, pKey, nKey);

  169043.   return pElem ? pElem->data : 0;

  169044. }

  169045. 

  169046. /* Insert an element into the hash table pH.  The key is pKey,nKey

  169047. ** and the data is "data".

  169048. **

  169049. ** If no element exists with a matching key, then a new

  169050. ** element is created.  A copy of the key is made if the copyKey

  169051. ** flag is set.  NULL is returned.

  169052. **

  169053. ** If another element already exists with the same key, then the

  169054. ** new data replaces the old data and the old data is returned.

  169055. ** The key is not copied in this instance.  If a malloc fails, then

  169056. ** the new data is returned and the hash table is unchanged.

  169057. **

  169058. ** If the "data" parameter to this function is NULL, then the

  169059. ** element corresponding to "key" is removed from the hash table.

  169060. */

  169061. SQLITE_PRIVATE void *sqlite3Fts3HashInsert(

  169062.   Fts3Hash *pH,        /* The hash table to insert into */

  169063.   const void *pKey,    /* The key */

  169064.   int nKey,            /* Number of bytes in the key */

  169065.   void *data           /* The data */

  169066. ){

  169067.   int hraw;                 /* Raw hash value of the key */

  169068.   int h;                    /* the hash of the key modulo hash table size */

  169069.   Fts3HashElem *elem;       /* Used to loop thru the element list */

  169070.   Fts3HashElem *new_elem;   /* New element added to the pH */

  169071.   int (*xHash)(const void*,int);  /* The hash function */

  169072. 

  169073.   assert( pH!=0 );

  169074.   xHash = ftsHashFunction(pH->keyClass);

  169075.   assert( xHash!=0 );

  169076.   hraw = (*xHash)(pKey, nKey);

  169077.   assert( (pH->htsize & (pH->htsize-1))==0 );

  169078.   h = hraw & (pH->htsize-1);

  169079.   elem = fts3FindElementByHash(pH,pKey,nKey,h);

  169080.   if( elem ){

  169081.     void *old_data = elem->data;

  169082.     if( data==0 ){

  169083.       fts3RemoveElementByHash(pH,elem,h);

  169084.     }else{

  169085.       elem->data = data;

  169086.     }

  169087.     return old_data;

  169088.   }

  169089.   if( data==0 ) return 0;

  169090.   if( (pH->htsize==0 && fts3Rehash(pH,8))

  169091.    || (pH->count>=pH->htsize && fts3Rehash(pH, pH->htsize*2))

  169092.   ){

  169093.     pH->count = 0;

  169094.     return data;

  169095.   }

  169096.   assert( pH->htsize>0 );

  169097.   new_elem = (Fts3HashElem*)fts3HashMalloc( sizeof(Fts3HashElem) );

  169098.   if( new_elem==0 ) return data;

  169099.   if( pH->copyKey && pKey!=0 ){

  169100.     new_elem->pKey = fts3HashMalloc( nKey );

  169101.     if( new_elem->pKey==0 ){

  169102.       fts3HashFree(new_elem);

  169103.       return data;

  169104.     }

  169105.     memcpy((void*)new_elem->pKey, pKey, nKey);

  169106.   }else{

  169107.     new_elem->pKey = (void*)pKey;

  169108.   }

  169109.   new_elem->nKey = nKey;

  169110.   pH->count++;

  169111.   assert( pH->htsize>0 );

  169112.   assert( (pH->htsize & (pH->htsize-1))==0 );

  169113.   h = hraw & (pH->htsize-1);

  169114.   fts3HashInsertElement(pH, &pH->ht[h], new_elem);

  169115.   new_elem->data = data;

  169116.   return 0;

  169117. }

  169118. 

  169119. #endif /* !defined(SQLITE_CORE) || defined(SQLITE_ENABLE_FTS3) */

  169120. 

  169121. /************** End of fts3_hash.c *******************************************/

  169122. /************** Begin file fts3_porter.c *************************************/

  169123. /*

  169124. ** 2006 September 30

  169125. **

  169126. ** The author disclaims copyright to this source code.  In place of

  169127. ** a legal notice, here is a blessing:

  169128. **

  169129. **    May you do good and not evil.

  169130. **    May you find forgiveness for yourself and forgive others.

  169131. **    May you share freely, never taking more than you give.

  169132. **

  169133. *************************************************************************

  169134. ** Implementation of the full-text-search tokenizer that implements

  169135. ** a Porter stemmer.

  169136. */

  169137. 

  169138. /*

  169139. ** The code in this file is only compiled if:

  169140. **

  169141. **     * The FTS3 module is being built as an extension

  169142. **       (in which case SQLITE_CORE is not defined), or

  169143. **

  169144. **     * The FTS3 module is being built into the core of

  169145. **       SQLite (in which case SQLITE_ENABLE_FTS3 is defined).

  169146. */

  169147. /* #include "fts3Int.h" */

  169148. #if !defined(SQLITE_CORE) || defined(SQLITE_ENABLE_FTS3)

  169149. 

  169150. /* #include <assert.h> */

  169151. /* #include <stdlib.h> */

  169152. /* #include <stdio.h> */

  169153. /* #include <string.h> */

  169154. 

  169155. /* #include "fts3_tokenizer.h" */

  169156. 

  169157. /*

  169158. ** Class derived from sqlite3_tokenizer

  169159. */

  169160. typedef struct porter_tokenizer {

  169161.   sqlite3_tokenizer base;      /* Base class */

  169162. } porter_tokenizer;

  169163. 

  169164. /*

  169165. ** Class derived from sqlite3_tokenizer_cursor

  169166. */

  169167. typedef struct porter_tokenizer_cursor {

  169168.   sqlite3_tokenizer_cursor base;

  169169.   const char *zInput;          /* input we are tokenizing */

  169170.   int nInput;                  /* size of the input */

  169171.   int iOffset;                 /* current position in zInput */

  169172.   int iToken;                  /* index of next token to be returned */

  169173.   char *zToken;                /* storage for current token */

  169174.   int nAllocated;              /* space allocated to zToken buffer */

  169175. } porter_tokenizer_cursor;

  169176. 

  169177. 

  169178. /*

  169179. ** Create a new tokenizer instance.

  169180. */

  169181. static int porterCreate(

  169182.   int argc, const char * const *argv,

  169183.   sqlite3_tokenizer **ppTokenizer

  169184. ){

  169185.   porter_tokenizer *t;

  169186. 

  169187.   UNUSED_PARAMETER(argc);

  169188.   UNUSED_PARAMETER(argv);

  169189. 

  169190.   t = (porter_tokenizer *) sqlite3_malloc(sizeof(*t));

  169191.   if( t==NULL ) return SQLITE_NOMEM;

  169192.   memset(t, 0, sizeof(*t));

  169193.   *ppTokenizer = &t->base;

  169194.   return SQLITE_OK;

  169195. }

  169196. 

  169197. /*

  169198. ** Destroy a tokenizer

  169199. */

  169200. static int porterDestroy(sqlite3_tokenizer *pTokenizer){

  169201.   sqlite3_free(pTokenizer);

  169202.   return SQLITE_OK;

  169203. }

  169204. 

  169205. /*

  169206. ** Prepare to begin tokenizing a particular string.  The input

  169207. ** string to be tokenized is zInput[0..nInput-1].  A cursor

  169208. ** used to incrementally tokenize this string is returned in 

  169209. ** *ppCursor.

  169210. */

  169211. static int porterOpen(

  169212.   sqlite3_tokenizer *pTokenizer,         /* The tokenizer */

  169213.   const char *zInput, int nInput,        /* String to be tokenized */

  169214.   sqlite3_tokenizer_cursor **ppCursor    /* OUT: Tokenization cursor */

  169215. ){

  169216.   porter_tokenizer_cursor *c;

  169217. 

  169218.   UNUSED_PARAMETER(pTokenizer);

  169219. 

  169220.   c = (porter_tokenizer_cursor *) sqlite3_malloc(sizeof(*c));

  169221.   if( c==NULL ) return SQLITE_NOMEM;

  169222. 

  169223.   c->zInput = zInput;

  169224.   if( zInput==0 ){

  169225.     c->nInput = 0;

  169226.   }else if( nInput<0 ){

  169227.     c->nInput = (int)strlen(zInput);

  169228.   }else{

  169229.     c->nInput = nInput;

  169230.   }

  169231.   c->iOffset = 0;                 /* start tokenizing at the beginning */

  169232.   c->iToken = 0;

  169233.   c->zToken = NULL;               /* no space allocated, yet. */

  169234.   c->nAllocated = 0;

  169235. 

  169236.   *ppCursor = &c->base;

  169237.   return SQLITE_OK;

  169238. }

  169239. 

  169240. /*

  169241. ** Close a tokenization cursor previously opened by a call to

  169242. ** porterOpen() above.

  169243. */

  169244. static int porterClose(sqlite3_tokenizer_cursor *pCursor){

  169245.   porter_tokenizer_cursor *c = (porter_tokenizer_cursor *) pCursor;

  169246.   sqlite3_free(c->zToken);

  169247.   sqlite3_free(c);

  169248.   return SQLITE_OK;

  169249. }

  169250. /*

  169251. ** Vowel or consonant

  169252. */

  169253. static const char cType[] = {

  169254.    0, 1, 1, 1, 0, 1, 1, 1, 0, 1, 1, 1, 1, 1, 0, 1, 1, 1, 1, 1, 0,

  169255.    1, 1, 1, 2, 1

  169256. };

  169257. 

  169258. /*

  169259. ** isConsonant() and isVowel() determine if their first character in

  169260. ** the string they point to is a consonant or a vowel, according

  169261. ** to Porter ruls.  

  169262. **

  169263. ** A consonate is any letter other than 'a', 'e', 'i', 'o', or 'u'.

  169264. ** 'Y' is a consonant unless it follows another consonant,

  169265. ** in which case it is a vowel.

  169266. **

  169267. ** In these routine, the letters are in reverse order.  So the 'y' rule

  169268. ** is that 'y' is a consonant unless it is followed by another

  169269. ** consonent.

  169270. */

  169271. static int isVowel(const char*);

  169272. static int isConsonant(const char *z){

  169273.   int j;

  169274.   char x = *z;

  169275.   if( x==0 ) return 0;

  169276.   assert( x>='a' && x<='z' );

  169277.   j = cType[x-'a'];

  169278.   if( j<2 ) return j;

  169279.   return z[1]==0 || isVowel(z + 1);

  169280. }

  169281. static int isVowel(const char *z){

  169282.   int j;

  169283.   char x = *z;

  169284.   if( x==0 ) return 0;

  169285.   assert( x>='a' && x<='z' );

  169286.   j = cType[x-'a'];

  169287.   if( j<2 ) return 1-j;

  169288.   return isConsonant(z + 1);

  169289. }

  169290. 

  169291. /*

  169292. ** Let any sequence of one or more vowels be represented by V and let

  169293. ** C be sequence of one or more consonants.  Then every word can be

  169294. ** represented as:

  169295. **

  169296. **           [C] (VC){m} [V]

  169297. **

  169298. ** In prose:  A word is an optional consonant followed by zero or

  169299. ** vowel-consonant pairs followed by an optional vowel.  "m" is the

  169300. ** number of vowel consonant pairs.  This routine computes the value

  169301. ** of m for the first i bytes of a word.

  169302. **

  169303. ** Return true if the m-value for z is 1 or more.  In other words,

  169304. ** return true if z contains at least one vowel that is followed

  169305. ** by a consonant.

  169306. **

  169307. ** In this routine z[] is in reverse order.  So we are really looking

  169308. ** for an instance of a consonant followed by a vowel.

  169309. */

  169310. static int m_gt_0(const char *z){

  169311.   while( isVowel(z) ){ z++; }

  169312.   if( *z==0 ) return 0;

  169313.   while( isConsonant(z) ){ z++; }

  169314.   return *z!=0;

  169315. }

  169316. 

  169317. /* Like mgt0 above except we are looking for a value of m which is

  169318. ** exactly 1

  169319. */

  169320. static int m_eq_1(const char *z){

  169321.   while( isVowel(z) ){ z++; }

  169322.   if( *z==0 ) return 0;

  169323.   while( isConsonant(z) ){ z++; }

  169324.   if( *z==0 ) return 0;

  169325.   while( isVowel(z) ){ z++; }

  169326.   if( *z==0 ) return 1;

  169327.   while( isConsonant(z) ){ z++; }

  169328.   return *z==0;

  169329. }

  169330. 

  169331. /* Like mgt0 above except we are looking for a value of m>1 instead

  169332. ** or m>0

  169333. */

  169334. static int m_gt_1(const char *z){

  169335.   while( isVowel(z) ){ z++; }

  169336.   if( *z==0 ) return 0;

  169337.   while( isConsonant(z) ){ z++; }

  169338.   if( *z==0 ) return 0;

  169339.   while( isVowel(z) ){ z++; }

  169340.   if( *z==0 ) return 0;

  169341.   while( isConsonant(z) ){ z++; }

  169342.   return *z!=0;

  169343. }

  169344. 

  169345. /*

  169346. ** Return TRUE if there is a vowel anywhere within z[0..n-1]

  169347. */

  169348. static int hasVowel(const char *z){

  169349.   while( isConsonant(z) ){ z++; }

  169350.   return *z!=0;

  169351. }

  169352. 

  169353. /*

  169354. ** Return TRUE if the word ends in a double consonant.

  169355. **

  169356. ** The text is reversed here. So we are really looking at

  169357. ** the first two characters of z[].

  169358. */

  169359. static int doubleConsonant(const char *z){

  169360.   return isConsonant(z) && z[0]==z[1];

  169361. }

  169362. 

  169363. /*

  169364. ** Return TRUE if the word ends with three letters which

  169365. ** are consonant-vowel-consonent and where the final consonant

  169366. ** is not 'w', 'x', or 'y'.

  169367. **

  169368. ** The word is reversed here.  So we are really checking the

  169369. ** first three letters and the first one cannot be in [wxy].

  169370. */

  169371. static int star_oh(const char *z){

  169372.   return

  169373.     isConsonant(z) &&

  169374.     z[0]!='w' && z[0]!='x' && z[0]!='y' &&

  169375.     isVowel(z+1) &&

  169376.     isConsonant(z+2);

  169377. }

  169378. 

  169379. /*

  169380. ** If the word ends with zFrom and xCond() is true for the stem

  169381. ** of the word that preceeds the zFrom ending, then change the 

  169382. ** ending to zTo.

  169383. **

  169384. ** The input word *pz and zFrom are both in reverse order.  zTo

  169385. ** is in normal order. 

  169386. **

  169387. ** Return TRUE if zFrom matches.  Return FALSE if zFrom does not

  169388. ** match.  Not that TRUE is returned even if xCond() fails and

  169389. ** no substitution occurs.

  169390. */

  169391. static int stem(

  169392.   char **pz,             /* The word being stemmed (Reversed) */

  169393.   const char *zFrom,     /* If the ending matches this... (Reversed) */

  169394.   const char *zTo,       /* ... change the ending to this (not reversed) */

  169395.   int (*xCond)(const char*)   /* Condition that must be true */

  169396. ){

  169397.   char *z = *pz;

  169398.   while( *zFrom && *zFrom==*z ){ z++; zFrom++; }

  169399.   if( *zFrom!=0 ) return 0;

  169400.   if( xCond && !xCond(z) ) return 1;

  169401.   while( *zTo ){

  169402.     *(--z) = *(zTo++);

  169403.   }

  169404.   *pz = z;

  169405.   return 1;

  169406. }

  169407. 

  169408. /*

  169409. ** This is the fallback stemmer used when the porter stemmer is

  169410. ** inappropriate.  The input word is copied into the output with

  169411. ** US-ASCII case folding.  If the input word is too long (more

  169412. ** than 20 bytes if it contains no digits or more than 6 bytes if

  169413. ** it contains digits) then word is truncated to 20 or 6 bytes

  169414. ** by taking 10 or 3 bytes from the beginning and end.

  169415. */

  169416. static void copy_stemmer(const char *zIn, int nIn, char *zOut, int *pnOut){

  169417.   int i, mx, j;

  169418.   int hasDigit = 0;

  169419.   for(i=0; i<nIn; i++){

  169420.     char c = zIn[i];

  169421.     if( c>='A' && c<='Z' ){

  169422.       zOut[i] = c - 'A' + 'a';

  169423.     }else{

  169424.       if( c>='0' && c<='9' ) hasDigit = 1;

  169425.       zOut[i] = c;

  169426.     }

  169427.   }

  169428.   mx = hasDigit ? 3 : 10;

  169429.   if( nIn>mx*2 ){

  169430.     for(j=mx, i=nIn-mx; i<nIn; i++, j++){

  169431.       zOut[j] = zOut[i];

  169432.     }

  169433.     i = j;

  169434.   }

  169435.   zOut[i] = 0;

  169436.   *pnOut = i;

  169437. }

  169438. 

  169439. 

  169440. /*

  169441. ** Stem the input word zIn[0..nIn-1].  Store the output in zOut.

  169442. ** zOut is at least big enough to hold nIn bytes.  Write the actual

  169443. ** size of the output word (exclusive of the '\0' terminator) into *pnOut.

  169444. **

  169445. ** Any upper-case characters in the US-ASCII character set ([A-Z])

  169446. ** are converted to lower case.  Upper-case UTF characters are

  169447. ** unchanged.

  169448. **

  169449. ** Words that are longer than about 20 bytes are stemmed by retaining

  169450. ** a few bytes from the beginning and the end of the word.  If the

  169451. ** word contains digits, 3 bytes are taken from the beginning and

  169452. ** 3 bytes from the end.  For long words without digits, 10 bytes

  169453. ** are taken from each end.  US-ASCII case folding still applies.

  169454. ** 

  169455. ** If the input word contains not digits but does characters not 

  169456. ** in [a-zA-Z] then no stemming is attempted and this routine just 

  169457. ** copies the input into the input into the output with US-ASCII

  169458. ** case folding.

  169459. **

  169460. ** Stemming never increases the length of the word.  So there is

  169461. ** no chance of overflowing the zOut buffer.

  169462. */

  169463. static void porter_stemmer(const char *zIn, int nIn, char *zOut, int *pnOut){

  169464.   int i, j;

  169465.   char zReverse[28];

  169466.   char *z, *z2;

  169467.   if( nIn<3 || nIn>=(int)sizeof(zReverse)-7 ){

  169468.     /* The word is too big or too small for the porter stemmer.

  169469.     ** Fallback to the copy stemmer */

  169470.     copy_stemmer(zIn, nIn, zOut, pnOut);

  169471.     return;

  169472.   }

  169473.   for(i=0, j=sizeof(zReverse)-6; i<nIn; i++, j--){

  169474.     char c = zIn[i];

  169475.     if( c>='A' && c<='Z' ){

  169476.       zReverse[j] = c + 'a' - 'A';

  169477.     }else if( c>='a' && c<='z' ){

  169478.       zReverse[j] = c;

  169479.     }else{

  169480.       /* The use of a character not in [a-zA-Z] means that we fallback

  169481.       ** to the copy stemmer */

  169482.       copy_stemmer(zIn, nIn, zOut, pnOut);

  169483.       return;

  169484.     }

  169485.   }

  169486.   memset(&zReverse[sizeof(zReverse)-5], 0, 5);

  169487.   z = &zReverse[j+1];

  169488. 

  169489. 

  169490.   /* Step 1a */

  169491.   if( z[0]=='s' ){

  169492.     if(

  169493.      !stem(&z, "sess", "ss", 0) &&

  169494.      !stem(&z, "sei", "i", 0)  &&

  169495.      !stem(&z, "ss", "ss", 0)

  169496.     ){

  169497.       z++;

  169498.     }

  169499.   }

  169500. 

  169501.   /* Step 1b */  

  169502.   z2 = z;

  169503.   if( stem(&z, "dee", "ee", m_gt_0) ){

  169504.     /* Do nothing.  The work was all in the test */

  169505.   }else if( 

  169506.      (stem(&z, "gni", "", hasVowel) || stem(&z, "de", "", hasVowel))

  169507.       && z!=z2

  169508.   ){

  169509.      if( stem(&z, "ta", "ate", 0) ||

  169510.          stem(&z, "lb", "ble", 0) ||

  169511.          stem(&z, "zi", "ize", 0) ){

  169512.        /* Do nothing.  The work was all in the test */

  169513.      }else if( doubleConsonant(z) && (*z!='l' && *z!='s' && *z!='z') ){

  169514.        z++;

  169515.      }else if( m_eq_1(z) && star_oh(z) ){

  169516.        *(--z) = 'e';

  169517.      }

  169518.   }

  169519. 

  169520.   /* Step 1c */

  169521.   if( z[0]=='y' && hasVowel(z+1) ){

  169522.     z[0] = 'i';

  169523.   }

  169524. 

  169525.   /* Step 2 */

  169526.   switch( z[1] ){

  169527.    case 'a':

  169528.      if( !stem(&z, "lanoita", "ate", m_gt_0) ){

  169529.        stem(&z, "lanoit", "tion", m_gt_0);

  169530.      }

  169531.      break;

  169532.    case 'c':

  169533.      if( !stem(&z, "icne", "ence", m_gt_0) ){

  169534.        stem(&z, "icna", "ance", m_gt_0);

  169535.      }

  169536.      break;

  169537.    case 'e':

  169538.      stem(&z, "rezi", "ize", m_gt_0);

  169539.      break;

  169540.    case 'g':

  169541.      stem(&z, "igol", "log", m_gt_0);

  169542.      break;

  169543.    case 'l':

  169544.      if( !stem(&z, "ilb", "ble", m_gt_0) 

  169545.       && !stem(&z, "illa", "al", m_gt_0)

  169546.       && !stem(&z, "iltne", "ent", m_gt_0)

  169547.       && !stem(&z, "ile", "e", m_gt_0)

  169548.      ){

  169549.        stem(&z, "ilsuo", "ous", m_gt_0);

  169550.      }

  169551.      break;

  169552.    case 'o':

  169553.      if( !stem(&z, "noitazi", "ize", m_gt_0)

  169554.       && !stem(&z, "noita", "ate", m_gt_0)

  169555.      ){

  169556.        stem(&z, "rota", "ate", m_gt_0);

  169557.      }

  169558.      break;

  169559.    case 's':

  169560.      if( !stem(&z, "msila", "al", m_gt_0)

  169561.       && !stem(&z, "ssenevi", "ive", m_gt_0)

  169562.       && !stem(&z, "ssenluf", "ful", m_gt_0)

  169563.      ){

  169564.        stem(&z, "ssensuo", "ous", m_gt_0);

  169565.      }

  169566.      break;

  169567.    case 't':

  169568.      if( !stem(&z, "itila", "al", m_gt_0)

  169569.       && !stem(&z, "itivi", "ive", m_gt_0)

  169570.      ){

  169571.        stem(&z, "itilib", "ble", m_gt_0);

  169572.      }

  169573.      break;

  169574.   }

  169575. 

  169576.   /* Step 3 */

  169577.   switch( z[0] ){

  169578.    case 'e':

  169579.      if( !stem(&z, "etaci", "ic", m_gt_0)

  169580.       && !stem(&z, "evita", "", m_gt_0)

  169581.      ){

  169582.        stem(&z, "ezila", "al", m_gt_0);

  169583.      }

  169584.      break;

  169585.    case 'i':

  169586.      stem(&z, "itici", "ic", m_gt_0);

  169587.      break;

  169588.    case 'l':

  169589.      if( !stem(&z, "laci", "ic", m_gt_0) ){

  169590.        stem(&z, "luf", "", m_gt_0);

  169591.      }

  169592.      break;

  169593.    case 's':

  169594.      stem(&z, "ssen", "", m_gt_0);

  169595.      break;

  169596.   }

  169597. 

  169598.   /* Step 4 */

  169599.   switch( z[1] ){

  169600.    case 'a':

  169601.      if( z[0]=='l' && m_gt_1(z+2) ){

  169602.        z += 2;

  169603.      }

  169604.      break;

  169605.    case 'c':

  169606.      if( z[0]=='e' && z[2]=='n' && (z[3]=='a' || z[3]=='e')  && m_gt_1(z+4)  ){

  169607.        z += 4;

  169608.      }

  169609.      break;

  169610.    case 'e':

  169611.      if( z[0]=='r' && m_gt_1(z+2) ){

  169612.        z += 2;

  169613.      }

  169614.      break;

  169615.    case 'i':

  169616.      if( z[0]=='c' && m_gt_1(z+2) ){

  169617.        z += 2;

  169618.      }

  169619.      break;

  169620.    case 'l':

  169621.      if( z[0]=='e' && z[2]=='b' && (z[3]=='a' || z[3]=='i') && m_gt_1(z+4) ){

  169622.        z += 4;

  169623.      }

  169624.      break;

  169625.    case 'n':

  169626.      if( z[0]=='t' ){

  169627.        if( z[2]=='a' ){

  169628.          if( m_gt_1(z+3) ){

  169629.            z += 3;

  169630.          }

  169631.        }else if( z[2]=='e' ){

  169632.          if( !stem(&z, "tneme", "", m_gt_1)

  169633.           && !stem(&z, "tnem", "", m_gt_1)

  169634.          ){

  169635.            stem(&z, "tne", "", m_gt_1);

  169636.          }

  169637.        }

  169638.      }

  169639.      break;

  169640.    case 'o':

  169641.      if( z[0]=='u' ){

  169642.        if( m_gt_1(z+2) ){

  169643.          z += 2;

  169644.        }

  169645.      }else if( z[3]=='s' || z[3]=='t' ){

  169646.        stem(&z, "noi", "", m_gt_1);

  169647.      }

  169648.      break;

  169649.    case 's':

  169650.      if( z[0]=='m' && z[2]=='i' && m_gt_1(z+3) ){

  169651.        z += 3;

  169652.      }

  169653.      break;

  169654.    case 't':

  169655.      if( !stem(&z, "eta", "", m_gt_1) ){

  169656.        stem(&z, "iti", "", m_gt_1);

  169657.      }

  169658.      break;

  169659.    case 'u':

  169660.      if( z[0]=='s' && z[2]=='o' && m_gt_1(z+3) ){

  169661.        z += 3;

  169662.      }

  169663.      break;

  169664.    case 'v':

  169665.    case 'z':

  169666.      if( z[0]=='e' && z[2]=='i' && m_gt_1(z+3) ){

  169667.        z += 3;

  169668.      }

  169669.      break;

  169670.   }

  169671. 

  169672.   /* Step 5a */

  169673.   if( z[0]=='e' ){

  169674.     if( m_gt_1(z+1) ){

  169675.       z++;

  169676.     }else if( m_eq_1(z+1) && !star_oh(z+1) ){

  169677.       z++;

  169678.     }

  169679.   }

  169680. 

  169681.   /* Step 5b */

  169682.   if( m_gt_1(z) && z[0]=='l' && z[1]=='l' ){

  169683.     z++;

  169684.   }

  169685. 

  169686.   /* z[] is now the stemmed word in reverse order.  Flip it back

  169687.   ** around into forward order and return.

  169688.   */

  169689.   *pnOut = i = (int)strlen(z);

  169690.   zOut[i] = 0;

  169691.   while( *z ){

  169692.     zOut[--i] = *(z++);

  169693.   }

  169694. }

  169695. 

  169696. /*

  169697. ** Characters that can be part of a token.  We assume any character

  169698. ** whose value is greater than 0x80 (any UTF character) can be

  169699. ** part of a token.  In other words, delimiters all must have

  169700. ** values of 0x7f or lower.

  169701. */

  169702. static const char porterIdChar[] = {

  169703. /* x0 x1 x2 x3 x4 x5 x6 x7 x8 x9 xA xB xC xD xE xF */

  169704.     1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0, 0, 0, 0, 0, 0,  /* 3x */

  169705.     0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,  /* 4x */

  169706.     1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0, 0, 0, 0, 1,  /* 5x */

  169707.     0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,  /* 6x */

  169708.     1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0, 0, 0, 0, 0,  /* 7x */

  169709. };

  169710. #define isDelim(C) (((ch=C)&0x80)==0 && (ch<0x30 || !porterIdChar[ch-0x30]))

  169711. 

  169712. /*

  169713. ** Extract the next token from a tokenization cursor.  The cursor must

  169714. ** have been opened by a prior call to porterOpen().

  169715. */

  169716. static int porterNext(

  169717.   sqlite3_tokenizer_cursor *pCursor,  /* Cursor returned by porterOpen */

  169718.   const char **pzToken,               /* OUT: *pzToken is the token text */

  169719.   int *pnBytes,                       /* OUT: Number of bytes in token */

  169720.   int *piStartOffset,                 /* OUT: Starting offset of token */

  169721.   int *piEndOffset,                   /* OUT: Ending offset of token */

  169722.   int *piPosition                     /* OUT: Position integer of token */

  169723. ){

  169724.   porter_tokenizer_cursor *c = (porter_tokenizer_cursor *) pCursor;

  169725.   const char *z = c->zInput;

  169726. 

  169727.   while( c->iOffset<c->nInput ){

  169728.     int iStartOffset, ch;

  169729. 

  169730.     /* Scan past delimiter characters */

  169731.     while( c->iOffset<c->nInput && isDelim(z[c->iOffset]) ){

  169732.       c->iOffset++;

  169733.     }

  169734. 

  169735.     /* Count non-delimiter characters. */

  169736.     iStartOffset = c->iOffset;

  169737.     while( c->iOffset<c->nInput && !isDelim(z[c->iOffset]) ){

  169738.       c->iOffset++;

  169739.     }

  169740. 

  169741.     if( c->iOffset>iStartOffset ){

  169742.       int n = c->iOffset-iStartOffset;

  169743.       if( n>c->nAllocated ){

  169744.         char *pNew;

  169745.         c->nAllocated = n+20;

  169746.         pNew = sqlite3_realloc(c->zToken, c->nAllocated);

  169747.         if( !pNew ) return SQLITE_NOMEM;

  169748.         c->zToken = pNew;

  169749.       }

  169750.       porter_stemmer(&z[iStartOffset], n, c->zToken, pnBytes);

  169751.       *pzToken = c->zToken;

  169752.       *piStartOffset = iStartOffset;

  169753.       *piEndOffset = c->iOffset;

  169754.       *piPosition = c->iToken++;

  169755.       return SQLITE_OK;

  169756.     }

  169757.   }

  169758.   return SQLITE_DONE;

  169759. }

  169760. 

  169761. /*

  169762. ** The set of routines that implement the porter-stemmer tokenizer

  169763. */

  169764. static const sqlite3_tokenizer_module porterTokenizerModule = {

  169765.   0,

  169766.   porterCreate,

  169767.   porterDestroy,

  169768.   porterOpen,

  169769.   porterClose,

  169770.   porterNext,

  169771.   0

  169772. };

  169773. 

  169774. /*

  169775. ** Allocate a new porter tokenizer.  Return a pointer to the new

  169776. ** tokenizer in *ppModule

  169777. */

  169778. SQLITE_PRIVATE void sqlite3Fts3PorterTokenizerModule(

  169779.   sqlite3_tokenizer_module const**ppModule

  169780. ){

  169781.   *ppModule = &porterTokenizerModule;

  169782. }

  169783. 

  169784. #endif /* !defined(SQLITE_CORE) || defined(SQLITE_ENABLE_FTS3) */

  169785. 

  169786. /************** End of fts3_porter.c *****************************************/

  169787. /************** Begin file fts3_tokenizer.c **********************************/

  169788. /*

  169789. ** 2007 June 22

  169790. **

  169791. ** The author disclaims copyright to this source code.  In place of

  169792. ** a legal notice, here is a blessing:

  169793. **

  169794. **    May you do good and not evil.

  169795. **    May you find forgiveness for yourself and forgive others.

  169796. **    May you share freely, never taking more than you give.

  169797. **

  169798. ******************************************************************************

  169799. **

  169800. ** This is part of an SQLite module implementing full-text search.

  169801. ** This particular file implements the generic tokenizer interface.

  169802. */

  169803. 

  169804. /*

  169805. ** The code in this file is only compiled if:

  169806. **

  169807. **     * The FTS3 module is being built as an extension

  169808. **       (in which case SQLITE_CORE is not defined), or

  169809. **

  169810. **     * The FTS3 module is being built into the core of

  169811. **       SQLite (in which case SQLITE_ENABLE_FTS3 is defined).

  169812. */

  169813. /* #include "fts3Int.h" */

  169814. #if !defined(SQLITE_CORE) || defined(SQLITE_ENABLE_FTS3)

  169815. 

  169816. /* #include <assert.h> */

  169817. /* #include <string.h> */

  169818. 

  169819. /*

  169820. ** Return true if the two-argument version of fts3_tokenizer()

  169821. ** has been activated via a prior call to sqlite3_db_config(db,

  169822. ** SQLITE_DBCONFIG_ENABLE_FTS3_TOKENIZER, 1, 0);

  169823. */

  169824. static int fts3TokenizerEnabled(sqlite3_context *context){

  169825.   sqlite3 *db = sqlite3_context_db_handle(context);

  169826.   int isEnabled = 0;

  169827.   sqlite3_db_config(db,SQLITE_DBCONFIG_ENABLE_FTS3_TOKENIZER,-1,&isEnabled);

  169828.   return isEnabled;

  169829. }

  169830. 

  169831. /*

  169832. ** Implementation of the SQL scalar function for accessing the underlying 

  169833. ** hash table. This function may be called as follows:

  169834. **

  169835. **   SELECT <function-name>(<key-name>);

  169836. **   SELECT <function-name>(<key-name>, <pointer>);

  169837. **

  169838. ** where <function-name> is the name passed as the second argument

  169839. ** to the sqlite3Fts3InitHashTable() function (e.g. 'fts3_tokenizer').

  169840. **

  169841. ** If the <pointer> argument is specified, it must be a blob value

  169842. ** containing a pointer to be stored as the hash data corresponding

  169843. ** to the string <key-name>. If <pointer> is not specified, then

  169844. ** the string <key-name> must already exist in the has table. Otherwise,

  169845. ** an error is returned.

  169846. **

  169847. ** Whether or not the <pointer> argument is specified, the value returned

  169848. ** is a blob containing the pointer stored as the hash data corresponding

  169849. ** to string <key-name> (after the hash-table is updated, if applicable).

  169850. */

  169851. static void fts3TokenizerFunc(

  169852.   sqlite3_context *context,

  169853.   int argc,

  169854.   sqlite3_value **argv

  169855. ){

  169856.   Fts3Hash *pHash;

  169857.   void *pPtr = 0;

  169858.   const unsigned char *zName;

  169859.   int nName;

  169860. 

  169861.   assert( argc==1 || argc==2 );

  169862. 

  169863.   pHash = (Fts3Hash *)sqlite3_user_data(context);

  169864. 

  169865.   zName = sqlite3_value_text(argv[0]);

  169866.   nName = sqlite3_value_bytes(argv[0])+1;

  169867. 

  169868.   if( argc==2 ){

  169869.     if( fts3TokenizerEnabled(context) || sqlite3_value_frombind(argv[1]) ){

  169870.       void *pOld;

  169871.       int n = sqlite3_value_bytes(argv[1]);

  169872.       if( zName==0 || n!=sizeof(pPtr) ){

  169873.         sqlite3_result_error(context, "argument type mismatch", -1);

  169874.         return;

  169875.       }

  169876.       pPtr = *(void **)sqlite3_value_blob(argv[1]);

  169877.       pOld = sqlite3Fts3HashInsert(pHash, (void *)zName, nName, pPtr);

  169878.       if( pOld==pPtr ){

  169879.         sqlite3_result_error(context, "out of memory", -1);

  169880.       }

  169881.     }else{

  169882.       sqlite3_result_error(context, "fts3tokenize disabled", -1);

  169883.       return;

  169884.     }

  169885.   }else{

  169886.     if( zName ){

  169887.       pPtr = sqlite3Fts3HashFind(pHash, zName, nName);

  169888.     }

  169889.     if( !pPtr ){

  169890.       char *zErr = sqlite3_mprintf("unknown tokenizer: %s", zName);

  169891.       sqlite3_result_error(context, zErr, -1);

  169892.       sqlite3_free(zErr);

  169893.       return;

  169894.     }

  169895.   }

  169896.   if( fts3TokenizerEnabled(context) || sqlite3_value_frombind(argv[0]) ){

  169897.     sqlite3_result_blob(context, (void *)&pPtr, sizeof(pPtr), SQLITE_TRANSIENT);

  169898.   }

  169899. }

  169900. 

  169901. SQLITE_PRIVATE int sqlite3Fts3IsIdChar(char c){

  169902.   static const char isFtsIdChar[] = {

  169903.       0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,  /* 0x */

  169904.       0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,  /* 1x */

  169905.       0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,  /* 2x */

  169906.       1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0, 0, 0, 0, 0, 0,  /* 3x */

  169907.       0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,  /* 4x */

  169908.       1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0, 0, 0, 0, 1,  /* 5x */

  169909.       0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,  /* 6x */

  169910.       1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0, 0, 0, 0, 0,  /* 7x */

  169911.   };

  169912.   return (c&0x80 || isFtsIdChar[(int)(c)]);

  169913. }

  169914. 

  169915. SQLITE_PRIVATE const char *sqlite3Fts3NextToken(const char *zStr, int *pn){

  169916.   const char *z1;

  169917.   const char *z2 = 0;

  169918. 

  169919.   /* Find the start of the next token. */

  169920.   z1 = zStr;

  169921.   while( z2==0 ){

  169922.     char c = *z1;

  169923.     switch( c ){

  169924.       case '\0': return 0;        /* No more tokens here */

  169925.       case '\'':

  169926.       case '"':

  169927.       case '`': {

  169928.         z2 = z1;

  169929.         while( *++z2 && (*z2!=c || *++z2==c) );

  169930.         break;

  169931.       }

  169932.       case '[':

  169933.         z2 = &z1[1];

  169934.         while( *z2 && z2[0]!=']' ) z2++;

  169935.         if( *z2 ) z2++;

  169936.         break;

  169937. 

  169938.       default:

  169939.         if( sqlite3Fts3IsIdChar(*z1) ){

  169940.           z2 = &z1[1];

  169941.           while( sqlite3Fts3IsIdChar(*z2) ) z2++;

  169942.         }else{

  169943.           z1++;

  169944.         }

  169945.     }

  169946.   }

  169947. 

  169948.   *pn = (int)(z2-z1);

  169949.   return z1;

  169950. }

  169951. 

  169952. SQLITE_PRIVATE int sqlite3Fts3InitTokenizer(

  169953.   Fts3Hash *pHash,                /* Tokenizer hash table */

  169954.   const char *zArg,               /* Tokenizer name */

  169955.   sqlite3_tokenizer **ppTok,      /* OUT: Tokenizer (if applicable) */

  169956.   char **pzErr                    /* OUT: Set to malloced error message */

  169957. ){

  169958.   int rc;

  169959.   char *z = (char *)zArg;

  169960.   int n = 0;

  169961.   char *zCopy;

  169962.   char *zEnd;                     /* Pointer to nul-term of zCopy */

  169963.   sqlite3_tokenizer_module *m;

  169964. 

  169965.   zCopy = sqlite3_mprintf("%s", zArg);

  169966.   if( !zCopy ) return SQLITE_NOMEM;

  169967.   zEnd = &zCopy[strlen(zCopy)];

  169968. 

  169969.   z = (char *)sqlite3Fts3NextToken(zCopy, &n);

  169970.   if( z==0 ){

  169971.     assert( n==0 );

  169972.     z = zCopy;

  169973.   }

  169974.   z[n] = '\0';

  169975.   sqlite3Fts3Dequote(z);

  169976. 

  169977.   m = (sqlite3_tokenizer_module *)sqlite3Fts3HashFind(pHash,z,(int)strlen(z)+1);

  169978.   if( !m ){

  169979.     sqlite3Fts3ErrMsg(pzErr, "unknown tokenizer: %s", z);

  169980.     rc = SQLITE_ERROR;

  169981.   }else{

  169982.     char const **aArg = 0;

  169983.     int iArg = 0;

  169984.     z = &z[n+1];

  169985.     while( z<zEnd && (NULL!=(z = (char *)sqlite3Fts3NextToken(z, &n))) ){

  169986.       sqlite3_int64 nNew = sizeof(char *)*(iArg+1);

  169987.       char const **aNew = (const char **)sqlite3_realloc64((void *)aArg, nNew);

  169988.       if( !aNew ){

  169989.         sqlite3_free(zCopy);

  169990.         sqlite3_free((void *)aArg);

  169991.         return SQLITE_NOMEM;

  169992.       }

  169993.       aArg = aNew;

  169994.       aArg[iArg++] = z;

  169995.       z[n] = '\0';

  169996.       sqlite3Fts3Dequote(z);

  169997.       z = &z[n+1];

  169998.     }

  169999.     rc = m->xCreate(iArg, aArg, ppTok);

  170000.     assert( rc!=SQLITE_OK || *ppTok );

  170001.     if( rc!=SQLITE_OK ){

  170002.       sqlite3Fts3ErrMsg(pzErr, "unknown tokenizer");

  170003.     }else{

  170004.       (*ppTok)->pModule = m; 

  170005.     }

  170006.     sqlite3_free((void *)aArg);

  170007.   }

  170008. 

  170009.   sqlite3_free(zCopy);

  170010.   return rc;

  170011. }

  170012. 

  170013. 

  170014. #ifdef SQLITE_TEST

  170015. 

  170016. #if defined(INCLUDE_SQLITE_TCL_H)

  170017. #  include "sqlite_tcl.h"

  170018. #else

  170019. #  include "tcl.h"

  170020. #endif

  170021. /* #include <string.h> */

  170022. 

  170023. /*

  170024. ** Implementation of a special SQL scalar function for testing tokenizers 

  170025. ** designed to be used in concert with the Tcl testing framework. This

  170026. ** function must be called with two or more arguments:

  170027. **

  170028. **   SELECT <function-name>(<key-name>, ..., <input-string>);

  170029. **

  170030. ** where <function-name> is the name passed as the second argument

  170031. ** to the sqlite3Fts3InitHashTable() function (e.g. 'fts3_tokenizer')

  170032. ** concatenated with the string '_test' (e.g. 'fts3_tokenizer_test').

  170033. **

  170034. ** The return value is a string that may be interpreted as a Tcl

  170035. ** list. For each token in the <input-string>, three elements are

  170036. ** added to the returned list. The first is the token position, the 

  170037. ** second is the token text (folded, stemmed, etc.) and the third is the

  170038. ** substring of <input-string> associated with the token. For example, 

  170039. ** using the built-in "simple" tokenizer:

  170040. **

  170041. **   SELECT fts_tokenizer_test('simple', 'I don't see how');

  170042. **

  170043. ** will return the string:

  170044. **

  170045. **   "{0 i I 1 dont don't 2 see see 3 how how}"

  170046. **   

  170047. */

  170048. static void testFunc(

  170049.   sqlite3_context *context,

  170050.   int argc,

  170051.   sqlite3_value **argv

  170052. ){

  170053.   Fts3Hash *pHash;

  170054.   sqlite3_tokenizer_module *p;

  170055.   sqlite3_tokenizer *pTokenizer = 0;

  170056.   sqlite3_tokenizer_cursor *pCsr = 0;

  170057. 

  170058.   const char *zErr = 0;

  170059. 

  170060.   const char *zName;

  170061.   int nName;

  170062.   const char *zInput;

  170063.   int nInput;

  170064. 

  170065.   const char *azArg[64];

  170066. 

  170067.   const char *zToken;

  170068.   int nToken = 0;

  170069.   int iStart = 0;

  170070.   int iEnd = 0;

  170071.   int iPos = 0;

  170072.   int i;

  170073. 

  170074.   Tcl_Obj *pRet;

  170075. 

  170076.   if( argc<2 ){

  170077.     sqlite3_result_error(context, "insufficient arguments", -1);

  170078.     return;

  170079.   }

  170080. 

  170081.   nName = sqlite3_value_bytes(argv[0]);

  170082.   zName = (const char *)sqlite3_value_text(argv[0]);

  170083.   nInput = sqlite3_value_bytes(argv[argc-1]);

  170084.   zInput = (const char *)sqlite3_value_text(argv[argc-1]);

  170085. 

  170086.   pHash = (Fts3Hash *)sqlite3_user_data(context);

  170087.   p = (sqlite3_tokenizer_module *)sqlite3Fts3HashFind(pHash, zName, nName+1);

  170088. 

  170089.   if( !p ){

  170090.     char *zErr2 = sqlite3_mprintf("unknown tokenizer: %s", zName);

  170091.     sqlite3_result_error(context, zErr2, -1);

  170092.     sqlite3_free(zErr2);

  170093.     return;

  170094.   }

  170095. 

  170096.   pRet = Tcl_NewObj();

  170097.   Tcl_IncrRefCount(pRet);

  170098. 

  170099.   for(i=1; i<argc-1; i++){

  170100.     azArg[i-1] = (const char *)sqlite3_value_text(argv[i]);

  170101.   }

  170102. 

  170103.   if( SQLITE_OK!=p->xCreate(argc-2, azArg, &pTokenizer) ){

  170104.     zErr = "error in xCreate()";

  170105.     goto finish;

  170106.   }

  170107.   pTokenizer->pModule = p;

  170108.   if( sqlite3Fts3OpenTokenizer(pTokenizer, 0, zInput, nInput, &pCsr) ){

  170109.     zErr = "error in xOpen()";

  170110.     goto finish;

  170111.   }

  170112. 

  170113.   while( SQLITE_OK==p->xNext(pCsr, &zToken, &nToken, &iStart, &iEnd, &iPos) ){

  170114.     Tcl_ListObjAppendElement(0, pRet, Tcl_NewIntObj(iPos));

  170115.     Tcl_ListObjAppendElement(0, pRet, Tcl_NewStringObj(zToken, nToken));

  170116.     zToken = &zInput[iStart];

  170117.     nToken = iEnd-iStart;

  170118.     Tcl_ListObjAppendElement(0, pRet, Tcl_NewStringObj(zToken, nToken));

  170119.   }

  170120. 

  170121.   if( SQLITE_OK!=p->xClose(pCsr) ){

  170122.     zErr = "error in xClose()";

  170123.     goto finish;

  170124.   }

  170125.   if( SQLITE_OK!=p->xDestroy(pTokenizer) ){

  170126.     zErr = "error in xDestroy()";

  170127.     goto finish;

  170128.   }

  170129. 

  170130. finish:

  170131.   if( zErr ){

  170132.     sqlite3_result_error(context, zErr, -1);

  170133.   }else{

  170134.     sqlite3_result_text(context, Tcl_GetString(pRet), -1, SQLITE_TRANSIENT);

  170135.   }

  170136.   Tcl_DecrRefCount(pRet);

  170137. }

  170138. 

  170139. static

  170140. int registerTokenizer(

  170141.   sqlite3 *db, 

  170142.   char *zName, 

  170143.   const sqlite3_tokenizer_module *p

  170144. ){

  170145.   int rc;

  170146.   sqlite3_stmt *pStmt;

  170147.   const char zSql[] = "SELECT fts3_tokenizer(?, ?)";

  170148. 

  170149.   rc = sqlite3_prepare_v2(db, zSql, -1, &pStmt, 0);

  170150.   if( rc!=SQLITE_OK ){

  170151.     return rc;

  170152.   }

  170153. 

  170154.   sqlite3_bind_text(pStmt, 1, zName, -1, SQLITE_STATIC);

  170155.   sqlite3_bind_blob(pStmt, 2, &p, sizeof(p), SQLITE_STATIC);

  170156.   sqlite3_step(pStmt);

  170157. 

  170158.   return sqlite3_finalize(pStmt);

  170159. }

  170160. 

  170161. 

  170162. static

  170163. int queryTokenizer(

  170164.   sqlite3 *db, 

  170165.   char *zName,  

  170166.   const sqlite3_tokenizer_module **pp

  170167. ){

  170168.   int rc;

  170169.   sqlite3_stmt *pStmt;

  170170.   const char zSql[] = "SELECT fts3_tokenizer(?)";

  170171. 

  170172.   *pp = 0;

  170173.   rc = sqlite3_prepare_v2(db, zSql, -1, &pStmt, 0);

  170174.   if( rc!=SQLITE_OK ){

  170175.     return rc;

  170176.   }

  170177. 

  170178.   sqlite3_bind_text(pStmt, 1, zName, -1, SQLITE_STATIC);

  170179.   if( SQLITE_ROW==sqlite3_step(pStmt) ){

  170180.     if( sqlite3_column_type(pStmt, 0)==SQLITE_BLOB ){

  170181.       memcpy((void *)pp, sqlite3_column_blob(pStmt, 0), sizeof(*pp));

  170182.     }

  170183.   }

  170184. 

  170185.   return sqlite3_finalize(pStmt);

  170186. }

  170187. 

  170188. SQLITE_PRIVATE void sqlite3Fts3SimpleTokenizerModule(sqlite3_tokenizer_module const**ppModule);

  170189. 

  170190. /*

  170191. ** Implementation of the scalar function fts3_tokenizer_internal_test().

  170192. ** This function is used for testing only, it is not included in the

  170193. ** build unless SQLITE_TEST is defined.

  170194. **

  170195. ** The purpose of this is to test that the fts3_tokenizer() function

  170196. ** can be used as designed by the C-code in the queryTokenizer and

  170197. ** registerTokenizer() functions above. These two functions are repeated

  170198. ** in the README.tokenizer file as an example, so it is important to

  170199. ** test them.

  170200. **

  170201. ** To run the tests, evaluate the fts3_tokenizer_internal_test() scalar

  170202. ** function with no arguments. An assert() will fail if a problem is

  170203. ** detected. i.e.:

  170204. **

  170205. **     SELECT fts3_tokenizer_internal_test();

  170206. **

  170207. */

  170208. static void intTestFunc(

  170209.   sqlite3_context *context,

  170210.   int argc,

  170211.   sqlite3_value **argv

  170212. ){

  170213.   int rc;

  170214.   const sqlite3_tokenizer_module *p1;

  170215.   const sqlite3_tokenizer_module *p2;

  170216.   sqlite3 *db = (sqlite3 *)sqlite3_user_data(context);

  170217. 

  170218.   UNUSED_PARAMETER(argc);

  170219.   UNUSED_PARAMETER(argv);

  170220. 

  170221.   /* Test the query function */

  170222.   sqlite3Fts3SimpleTokenizerModule(&p1);

  170223.   rc = queryTokenizer(db, "simple", &p2);

  170224.   assert( rc==SQLITE_OK );

  170225.   assert( p1==p2 );

  170226.   rc = queryTokenizer(db, "nosuchtokenizer", &p2);

  170227.   assert( rc==SQLITE_ERROR );

  170228.   assert( p2==0 );

  170229.   assert( 0==strcmp(sqlite3_errmsg(db), "unknown tokenizer: nosuchtokenizer") );

  170230. 

  170231.   /* Test the storage function */

  170232.   if( fts3TokenizerEnabled(context) ){

  170233.     rc = registerTokenizer(db, "nosuchtokenizer", p1);

  170234.     assert( rc==SQLITE_OK );

  170235.     rc = queryTokenizer(db, "nosuchtokenizer", &p2);

  170236.     assert( rc==SQLITE_OK );

  170237.     assert( p2==p1 );

  170238.   }

  170239. 

  170240.   sqlite3_result_text(context, "ok", -1, SQLITE_STATIC);

  170241. }

  170242. 

  170243. #endif

  170244. 

  170245. /*

  170246. ** Set up SQL objects in database db used to access the contents of

  170247. ** the hash table pointed to by argument pHash. The hash table must

  170248. ** been initialized to use string keys, and to take a private copy 

  170249. ** of the key when a value is inserted. i.e. by a call similar to:

  170250. **

  170251. **    sqlite3Fts3HashInit(pHash, FTS3_HASH_STRING, 1);

  170252. **

  170253. ** This function adds a scalar function (see header comment above

  170254. ** fts3TokenizerFunc() in this file for details) and, if ENABLE_TABLE is

  170255. ** defined at compilation time, a temporary virtual table (see header 

  170256. ** comment above struct HashTableVtab) to the database schema. Both 

  170257. ** provide read/write access to the contents of *pHash.

  170258. **

  170259. ** The third argument to this function, zName, is used as the name

  170260. ** of both the scalar and, if created, the virtual table.

  170261. */

  170262. SQLITE_PRIVATE int sqlite3Fts3InitHashTable(

  170263.   sqlite3 *db, 

  170264.   Fts3Hash *pHash, 

  170265.   const char *zName

  170266. ){

  170267.   int rc = SQLITE_OK;

  170268.   void *p = (void *)pHash;

  170269.   const int any = SQLITE_ANY;

  170270. 

  170271. #ifdef SQLITE_TEST

  170272.   char *zTest = 0;

  170273.   char *zTest2 = 0;

  170274.   void *pdb = (void *)db;

  170275.   zTest = sqlite3_mprintf("%s_test", zName);

  170276.   zTest2 = sqlite3_mprintf("%s_internal_test", zName);

  170277.   if( !zTest || !zTest2 ){

  170278.     rc = SQLITE_NOMEM;

  170279.   }

  170280. #endif

  170281. 

  170282.   if( SQLITE_OK==rc ){

  170283.     rc = sqlite3_create_function(db, zName, 1, any, p, fts3TokenizerFunc, 0, 0);

  170284.   }

  170285.   if( SQLITE_OK==rc ){

  170286.     rc = sqlite3_create_function(db, zName, 2, any, p, fts3TokenizerFunc, 0, 0);

  170287.   }

  170288. #ifdef SQLITE_TEST

  170289.   if( SQLITE_OK==rc ){

  170290.     rc = sqlite3_create_function(db, zTest, -1, any, p, testFunc, 0, 0);

  170291.   }

  170292.   if( SQLITE_OK==rc ){

  170293.     rc = sqlite3_create_function(db, zTest2, 0, any, pdb, intTestFunc, 0, 0);

  170294.   }

  170295. #endif

  170296. 

  170297. #ifdef SQLITE_TEST

  170298.   sqlite3_free(zTest);

  170299.   sqlite3_free(zTest2);

  170300. #endif

  170301. 

  170302.   return rc;

  170303. }

  170304. 

  170305. #endif /* !defined(SQLITE_CORE) || defined(SQLITE_ENABLE_FTS3) */

  170306. 

  170307. /************** End of fts3_tokenizer.c **************************************/

  170308. /************** Begin file fts3_tokenizer1.c *********************************/

  170309. /*

  170310. ** 2006 Oct 10

  170311. **

  170312. ** The author disclaims copyright to this source code.  In place of

  170313. ** a legal notice, here is a blessing:

  170314. **

  170315. **    May you do good and not evil.

  170316. **    May you find forgiveness for yourself and forgive others.

  170317. **    May you share freely, never taking more than you give.

  170318. **

  170319. ******************************************************************************

  170320. **

  170321. ** Implementation of the "simple" full-text-search tokenizer.

  170322. */

  170323. 

  170324. /*

  170325. ** The code in this file is only compiled if:

  170326. **

  170327. **     * The FTS3 module is being built as an extension

  170328. **       (in which case SQLITE_CORE is not defined), or

  170329. **

  170330. **     * The FTS3 module is being built into the core of

  170331. **       SQLite (in which case SQLITE_ENABLE_FTS3 is defined).

  170332. */

  170333. /* #include "fts3Int.h" */

  170334. #if !defined(SQLITE_CORE) || defined(SQLITE_ENABLE_FTS3)

  170335. 

  170336. /* #include <assert.h> */

  170337. /* #include <stdlib.h> */

  170338. /* #include <stdio.h> */

  170339. /* #include <string.h> */

  170340. 

  170341. /* #include "fts3_tokenizer.h" */

  170342. 

  170343. typedef struct simple_tokenizer {

  170344.   sqlite3_tokenizer base;

  170345.   char delim[128];             /* flag ASCII delimiters */

  170346. } simple_tokenizer;

  170347. 

  170348. typedef struct simple_tokenizer_cursor {

  170349.   sqlite3_tokenizer_cursor base;

  170350.   const char *pInput;          /* input we are tokenizing */

  170351.   int nBytes;                  /* size of the input */

  170352.   int iOffset;                 /* current position in pInput */

  170353.   int iToken;                  /* index of next token to be returned */

  170354.   char *pToken;                /* storage for current token */

  170355.   int nTokenAllocated;         /* space allocated to zToken buffer */

  170356. } simple_tokenizer_cursor;

  170357. 

  170358. 

  170359. static int simpleDelim(simple_tokenizer *t, unsigned char c){

  170360.   return c<0x80 && t->delim[c];

  170361. }

  170362. static int fts3_isalnum(int x){

  170363.   return (x>='0' && x<='9') || (x>='A' && x<='Z') || (x>='a' && x<='z');

  170364. }

  170365. 

  170366. /*

  170367. ** Create a new tokenizer instance.

  170368. */

  170369. static int simpleCreate(

  170370.   int argc, const char * const *argv,

  170371.   sqlite3_tokenizer **ppTokenizer

  170372. ){

  170373.   simple_tokenizer *t;

  170374. 

  170375.   t = (simple_tokenizer *) sqlite3_malloc(sizeof(*t));

  170376.   if( t==NULL ) return SQLITE_NOMEM;

  170377.   memset(t, 0, sizeof(*t));

  170378. 

  170379.   /* TODO(shess) Delimiters need to remain the same from run to run,

  170380.   ** else we need to reindex.  One solution would be a meta-table to

  170381.   ** track such information in the database, then we'd only want this

  170382.   ** information on the initial create.

  170383.   */

  170384.   if( argc>1 ){

  170385.     int i, n = (int)strlen(argv[1]);

  170386.     for(i=0; i<n; i++){

  170387.       unsigned char ch = argv[1][i];

  170388.       /* We explicitly don't support UTF-8 delimiters for now. */

  170389.       if( ch>=0x80 ){

  170390.         sqlite3_free(t);

  170391.         return SQLITE_ERROR;

  170392.       }

  170393.       t->delim[ch] = 1;

  170394.     }

  170395.   } else {

  170396.     /* Mark non-alphanumeric ASCII characters as delimiters */

  170397.     int i;

  170398.     for(i=1; i<0x80; i++){

  170399.       t->delim[i] = !fts3_isalnum(i) ? -1 : 0;

  170400.     }

  170401.   }

  170402. 

  170403.   *ppTokenizer = &t->base;

  170404.   return SQLITE_OK;

  170405. }

  170406. 

  170407. /*

  170408. ** Destroy a tokenizer

  170409. */

  170410. static int simpleDestroy(sqlite3_tokenizer *pTokenizer){

  170411.   sqlite3_free(pTokenizer);

  170412.   return SQLITE_OK;

  170413. }

  170414. 

  170415. /*

  170416. ** Prepare to begin tokenizing a particular string.  The input

  170417. ** string to be tokenized is pInput[0..nBytes-1].  A cursor

  170418. ** used to incrementally tokenize this string is returned in 

  170419. ** *ppCursor.

  170420. */

  170421. static int simpleOpen(

  170422.   sqlite3_tokenizer *pTokenizer,         /* The tokenizer */

  170423.   const char *pInput, int nBytes,        /* String to be tokenized */

  170424.   sqlite3_tokenizer_cursor **ppCursor    /* OUT: Tokenization cursor */

  170425. ){

  170426.   simple_tokenizer_cursor *c;

  170427. 

  170428.   UNUSED_PARAMETER(pTokenizer);

  170429. 

  170430.   c = (simple_tokenizer_cursor *) sqlite3_malloc(sizeof(*c));

  170431.   if( c==NULL ) return SQLITE_NOMEM;

  170432. 

  170433.   c->pInput = pInput;

  170434.   if( pInput==0 ){

  170435.     c->nBytes = 0;

  170436.   }else if( nBytes<0 ){

  170437.     c->nBytes = (int)strlen(pInput);

  170438.   }else{

  170439.     c->nBytes = nBytes;

  170440.   }

  170441.   c->iOffset = 0;                 /* start tokenizing at the beginning */

  170442.   c->iToken = 0;

  170443.   c->pToken = NULL;               /* no space allocated, yet. */

  170444.   c->nTokenAllocated = 0;

  170445. 

  170446.   *ppCursor = &c->base;

  170447.   return SQLITE_OK;

  170448. }

  170449. 

  170450. /*

  170451. ** Close a tokenization cursor previously opened by a call to

  170452. ** simpleOpen() above.

  170453. */

  170454. static int simpleClose(sqlite3_tokenizer_cursor *pCursor){

  170455.   simple_tokenizer_cursor *c = (simple_tokenizer_cursor *) pCursor;

  170456.   sqlite3_free(c->pToken);

  170457.   sqlite3_free(c);

  170458.   return SQLITE_OK;

  170459. }

  170460. 

  170461. /*

  170462. ** Extract the next token from a tokenization cursor.  The cursor must

  170463. ** have been opened by a prior call to simpleOpen().

  170464. */

  170465. static int simpleNext(

  170466.   sqlite3_tokenizer_cursor *pCursor,  /* Cursor returned by simpleOpen */

  170467.   const char **ppToken,               /* OUT: *ppToken is the token text */

  170468.   int *pnBytes,                       /* OUT: Number of bytes in token */

  170469.   int *piStartOffset,                 /* OUT: Starting offset of token */

  170470.   int *piEndOffset,                   /* OUT: Ending offset of token */

  170471.   int *piPosition                     /* OUT: Position integer of token */

  170472. ){

  170473.   simple_tokenizer_cursor *c = (simple_tokenizer_cursor *) pCursor;

  170474.   simple_tokenizer *t = (simple_tokenizer *) pCursor->pTokenizer;

  170475.   unsigned char *p = (unsigned char *)c->pInput;

  170476. 

  170477.   while( c->iOffset<c->nBytes ){

  170478.     int iStartOffset;

  170479. 

  170480.     /* Scan past delimiter characters */

  170481.     while( c->iOffset<c->nBytes && simpleDelim(t, p[c->iOffset]) ){

  170482.       c->iOffset++;

  170483.     }

  170484. 

  170485.     /* Count non-delimiter characters. */

  170486.     iStartOffset = c->iOffset;

  170487.     while( c->iOffset<c->nBytes && !simpleDelim(t, p[c->iOffset]) ){

  170488.       c->iOffset++;

  170489.     }

  170490. 

  170491.     if( c->iOffset>iStartOffset ){

  170492.       int i, n = c->iOffset-iStartOffset;

  170493.       if( n>c->nTokenAllocated ){

  170494.         char *pNew;

  170495.         c->nTokenAllocated = n+20;

  170496.         pNew = sqlite3_realloc(c->pToken, c->nTokenAllocated);

  170497.         if( !pNew ) return SQLITE_NOMEM;

  170498.         c->pToken = pNew;

  170499.       }

  170500.       for(i=0; i<n; i++){

  170501.         /* TODO(shess) This needs expansion to handle UTF-8

  170502.         ** case-insensitivity.

  170503.         */

  170504.         unsigned char ch = p[iStartOffset+i];

  170505.         c->pToken[i] = (char)((ch>='A' && ch<='Z') ? ch-'A'+'a' : ch);

  170506.       }

  170507.       *ppToken = c->pToken;

  170508.       *pnBytes = n;

  170509.       *piStartOffset = iStartOffset;

  170510.       *piEndOffset = c->iOffset;

  170511.       *piPosition = c->iToken++;

  170512. 

  170513.       return SQLITE_OK;

  170514.     }

  170515.   }

  170516.   return SQLITE_DONE;

  170517. }

  170518. 

  170519. /*

  170520. ** The set of routines that implement the simple tokenizer

  170521. */

  170522. static const sqlite3_tokenizer_module simpleTokenizerModule = {

  170523.   0,

  170524.   simpleCreate,

  170525.   simpleDestroy,

  170526.   simpleOpen,

  170527.   simpleClose,

  170528.   simpleNext,

  170529.   0,

  170530. };

  170531. 

  170532. /*

  170533. ** Allocate a new simple tokenizer.  Return a pointer to the new

  170534. ** tokenizer in *ppModule

  170535. */

  170536. SQLITE_PRIVATE void sqlite3Fts3SimpleTokenizerModule(

  170537.   sqlite3_tokenizer_module const**ppModule

  170538. ){

  170539.   *ppModule = &simpleTokenizerModule;

  170540. }

  170541. 

  170542. #endif /* !defined(SQLITE_CORE) || defined(SQLITE_ENABLE_FTS3) */

  170543. 

  170544. /************** End of fts3_tokenizer1.c *************************************/

  170545. /************** Begin file fts3_tokenize_vtab.c ******************************/

  170546. /*

  170547. ** 2013 Apr 22

  170548. **

  170549. ** The author disclaims copyright to this source code.  In place of

  170550. ** a legal notice, here is a blessing:

  170551. **

  170552. **    May you do good and not evil.

  170553. **    May you find forgiveness for yourself and forgive others.

  170554. **    May you share freely, never taking more than you give.

  170555. **

  170556. ******************************************************************************

  170557. **

  170558. ** This file contains code for the "fts3tokenize" virtual table module.

  170559. ** An fts3tokenize virtual table is created as follows:

  170560. **

  170561. **   CREATE VIRTUAL TABLE <tbl> USING fts3tokenize(

  170562. **       <tokenizer-name>, <arg-1>, ...

  170563. **   );

  170564. **

  170565. ** The table created has the following schema:

  170566. **

  170567. **   CREATE TABLE <tbl>(input, token, start, end, position)

  170568. **

  170569. ** When queried, the query must include a WHERE clause of type:

  170570. **

  170571. **   input = <string>

  170572. **

  170573. ** The virtual table module tokenizes this <string>, using the FTS3 

  170574. ** tokenizer specified by the arguments to the CREATE VIRTUAL TABLE 

  170575. ** statement and returns one row for each token in the result. With

  170576. ** fields set as follows:

  170577. **

  170578. **   input:   Always set to a copy of <string>

  170579. **   token:   A token from the input.

  170580. **   start:   Byte offset of the token within the input <string>.

  170581. **   end:     Byte offset of the byte immediately following the end of the

  170582. **            token within the input string.

  170583. **   pos:     Token offset of token within input.

  170584. **

  170585. */

  170586. /* #include "fts3Int.h" */

  170587. #if !defined(SQLITE_CORE) || defined(SQLITE_ENABLE_FTS3)

  170588. 

  170589. /* #include <string.h> */

  170590. /* #include <assert.h> */

  170591. 

  170592. typedef struct Fts3tokTable Fts3tokTable;

  170593. typedef struct Fts3tokCursor Fts3tokCursor;

  170594. 

  170595. /*

  170596. ** Virtual table structure.

  170597. */

  170598. struct Fts3tokTable {

  170599.   sqlite3_vtab base;              /* Base class used by SQLite core */

  170600.   const sqlite3_tokenizer_module *pMod;

  170601.   sqlite3_tokenizer *pTok;

  170602. };

  170603. 

  170604. /*

  170605. ** Virtual table cursor structure.

  170606. */

  170607. struct Fts3tokCursor {

  170608.   sqlite3_vtab_cursor base;       /* Base class used by SQLite core */

  170609.   char *zInput;                   /* Input string */

  170610.   sqlite3_tokenizer_cursor *pCsr; /* Cursor to iterate through zInput */

  170611.   int iRowid;                     /* Current 'rowid' value */

  170612.   const char *zToken;             /* Current 'token' value */

  170613.   int nToken;                     /* Size of zToken in bytes */

  170614.   int iStart;                     /* Current 'start' value */

  170615.   int iEnd;                       /* Current 'end' value */

  170616.   int iPos;                       /* Current 'pos' value */

  170617. };

  170618. 

  170619. /*

  170620. ** Query FTS for the tokenizer implementation named zName.

  170621. */

  170622. static int fts3tokQueryTokenizer(

  170623.   Fts3Hash *pHash,

  170624.   const char *zName,

  170625.   const sqlite3_tokenizer_module **pp,

  170626.   char **pzErr

  170627. ){

  170628.   sqlite3_tokenizer_module *p;

  170629.   int nName = (int)strlen(zName);

  170630. 

  170631.   p = (sqlite3_tokenizer_module *)sqlite3Fts3HashFind(pHash, zName, nName+1);

  170632.   if( !p ){

  170633.     sqlite3Fts3ErrMsg(pzErr, "unknown tokenizer: %s", zName);

  170634.     return SQLITE_ERROR;

  170635.   }

  170636. 

  170637.   *pp = p;

  170638.   return SQLITE_OK;

  170639. }

  170640. 

  170641. /*

  170642. ** The second argument, argv[], is an array of pointers to nul-terminated

  170643. ** strings. This function makes a copy of the array and strings into a 

  170644. ** single block of memory. It then dequotes any of the strings that appear

  170645. ** to be quoted.

  170646. **

  170647. ** If successful, output parameter *pazDequote is set to point at the

  170648. ** array of dequoted strings and SQLITE_OK is returned. The caller is

  170649. ** responsible for eventually calling sqlite3_free() to free the array

  170650. ** in this case. Or, if an error occurs, an SQLite error code is returned.

  170651. ** The final value of *pazDequote is undefined in this case.

  170652. */

  170653. static int fts3tokDequoteArray(

  170654.   int argc,                       /* Number of elements in argv[] */

  170655.   const char * const *argv,       /* Input array */

  170656.   char ***pazDequote              /* Output array */

  170657. ){

  170658.   int rc = SQLITE_OK;             /* Return code */

  170659.   if( argc==0 ){

  170660.     *pazDequote = 0;

  170661.   }else{

  170662.     int i;

  170663.     int nByte = 0;

  170664.     char **azDequote;

  170665. 

  170666.     for(i=0; i<argc; i++){

  170667.       nByte += (int)(strlen(argv[i]) + 1);

  170668.     }

  170669. 

  170670.     *pazDequote = azDequote = sqlite3_malloc64(sizeof(char *)*argc + nByte);

  170671.     if( azDequote==0 ){

  170672.       rc = SQLITE_NOMEM;

  170673.     }else{

  170674.       char *pSpace = (char *)&azDequote[argc];

  170675.       for(i=0; i<argc; i++){

  170676.         int n = (int)strlen(argv[i]);

  170677.         azDequote[i] = pSpace;

  170678.         memcpy(pSpace, argv[i], n+1);

  170679.         sqlite3Fts3Dequote(pSpace);

  170680.         pSpace += (n+1);

  170681.       }

  170682.     }

  170683.   }

  170684. 

  170685.   return rc;

  170686. }

  170687. 

  170688. /*

  170689. ** Schema of the tokenizer table.

  170690. */

  170691. #define FTS3_TOK_SCHEMA "CREATE TABLE x(input, token, start, end, position)"

  170692. 

  170693. /*

  170694. ** This function does all the work for both the xConnect and xCreate methods.

  170695. ** These tables have no persistent representation of their own, so xConnect

  170696. ** and xCreate are identical operations.

  170697. **

  170698. **   argv[0]: module name

  170699. **   argv[1]: database name 

  170700. **   argv[2]: table name

  170701. **   argv[3]: first argument (tokenizer name)

  170702. */

  170703. static int fts3tokConnectMethod(

  170704.   sqlite3 *db,                    /* Database connection */

  170705.   void *pHash,                    /* Hash table of tokenizers */

  170706.   int argc,                       /* Number of elements in argv array */

  170707.   const char * const *argv,       /* xCreate/xConnect argument array */

  170708.   sqlite3_vtab **ppVtab,          /* OUT: New sqlite3_vtab object */

  170709.   char **pzErr                    /* OUT: sqlite3_malloc'd error message */

  170710. ){

  170711.   Fts3tokTable *pTab = 0;

  170712.   const sqlite3_tokenizer_module *pMod = 0;

  170713.   sqlite3_tokenizer *pTok = 0;

  170714.   int rc;

  170715.   char **azDequote = 0;

  170716.   int nDequote;

  170717. 

  170718.   rc = sqlite3_declare_vtab(db, FTS3_TOK_SCHEMA);

  170719.   if( rc!=SQLITE_OK ) return rc;

  170720. 

  170721.   nDequote = argc-3;

  170722.   rc = fts3tokDequoteArray(nDequote, &argv[3], &azDequote);

  170723. 

  170724.   if( rc==SQLITE_OK ){

  170725.     const char *zModule;

  170726.     if( nDequote<1 ){

  170727.       zModule = "simple";

  170728.     }else{

  170729.       zModule = azDequote[0];

  170730.     }

  170731.     rc = fts3tokQueryTokenizer((Fts3Hash*)pHash, zModule, &pMod, pzErr);

  170732.   }

  170733. 

  170734.   assert( (rc==SQLITE_OK)==(pMod!=0) );

  170735.   if( rc==SQLITE_OK ){

  170736.     const char * const *azArg = (const char * const *)&azDequote[1];

  170737.     rc = pMod->xCreate((nDequote>1 ? nDequote-1 : 0), azArg, &pTok);

  170738.   }

  170739. 

  170740.   if( rc==SQLITE_OK ){

  170741.     pTab = (Fts3tokTable *)sqlite3_malloc(sizeof(Fts3tokTable));

  170742.     if( pTab==0 ){

  170743.       rc = SQLITE_NOMEM;

  170744.     }

  170745.   }

  170746. 

  170747.   if( rc==SQLITE_OK ){

  170748.     memset(pTab, 0, sizeof(Fts3tokTable));

  170749.     pTab->pMod = pMod;

  170750.     pTab->pTok = pTok;

  170751.     *ppVtab = &pTab->base;

  170752.   }else{

  170753.     if( pTok ){

  170754.       pMod->xDestroy(pTok);

  170755.     }

  170756.   }

  170757. 

  170758.   sqlite3_free(azDequote);

  170759.   return rc;

  170760. }

  170761. 

  170762. /*

  170763. ** This function does the work for both the xDisconnect and xDestroy methods.

  170764. ** These tables have no persistent representation of their own, so xDisconnect

  170765. ** and xDestroy are identical operations.

  170766. */

  170767. static int fts3tokDisconnectMethod(sqlite3_vtab *pVtab){

  170768.   Fts3tokTable *pTab = (Fts3tokTable *)pVtab;

  170769. 

  170770.   pTab->pMod->xDestroy(pTab->pTok);

  170771.   sqlite3_free(pTab);

  170772.   return SQLITE_OK;

  170773. }

  170774. 

  170775. /*

  170776. ** xBestIndex - Analyze a WHERE and ORDER BY clause.

  170777. */

  170778. static int fts3tokBestIndexMethod(

  170779.   sqlite3_vtab *pVTab, 

  170780.   sqlite3_index_info *pInfo

  170781. ){

  170782.   int i;

  170783.   UNUSED_PARAMETER(pVTab);

  170784. 

  170785.   for(i=0; i<pInfo->nConstraint; i++){

  170786.     if( pInfo->aConstraint[i].usable 

  170787.      && pInfo->aConstraint[i].iColumn==0 

  170788.      && pInfo->aConstraint[i].op==SQLITE_INDEX_CONSTRAINT_EQ 

  170789.     ){

  170790.       pInfo->idxNum = 1;

  170791.       pInfo->aConstraintUsage[i].argvIndex = 1;

  170792.       pInfo->aConstraintUsage[i].omit = 1;

  170793.       pInfo->estimatedCost = 1;

  170794.       return SQLITE_OK;

  170795.     }

  170796.   }

  170797. 

  170798.   pInfo->idxNum = 0;

  170799.   assert( pInfo->estimatedCost>1000000.0 );

  170800. 

  170801.   return SQLITE_OK;

  170802. }

  170803. 

  170804. /*

  170805. ** xOpen - Open a cursor.

  170806. */

  170807. static int fts3tokOpenMethod(sqlite3_vtab *pVTab, sqlite3_vtab_cursor **ppCsr){

  170808.   Fts3tokCursor *pCsr;

  170809.   UNUSED_PARAMETER(pVTab);

  170810. 

  170811.   pCsr = (Fts3tokCursor *)sqlite3_malloc(sizeof(Fts3tokCursor));

  170812.   if( pCsr==0 ){

  170813.     return SQLITE_NOMEM;

  170814.   }

  170815.   memset(pCsr, 0, sizeof(Fts3tokCursor));

  170816. 

  170817.   *ppCsr = (sqlite3_vtab_cursor *)pCsr;

  170818.   return SQLITE_OK;

  170819. }

  170820. 

  170821. /*

  170822. ** Reset the tokenizer cursor passed as the only argument. As if it had

  170823. ** just been returned by fts3tokOpenMethod().

  170824. */

  170825. static void fts3tokResetCursor(Fts3tokCursor *pCsr){

  170826.   if( pCsr->pCsr ){

  170827.     Fts3tokTable *pTab = (Fts3tokTable *)(pCsr->base.pVtab);

  170828.     pTab->pMod->xClose(pCsr->pCsr);

  170829.     pCsr->pCsr = 0;

  170830.   }

  170831.   sqlite3_free(pCsr->zInput);

  170832.   pCsr->zInput = 0;

  170833.   pCsr->zToken = 0;

  170834.   pCsr->nToken = 0;

  170835.   pCsr->iStart = 0;

  170836.   pCsr->iEnd = 0;

  170837.   pCsr->iPos = 0;

  170838.   pCsr->iRowid = 0;

  170839. }

  170840. 

  170841. /*

  170842. ** xClose - Close a cursor.

  170843. */

  170844. static int fts3tokCloseMethod(sqlite3_vtab_cursor *pCursor){

  170845.   Fts3tokCursor *pCsr = (Fts3tokCursor *)pCursor;

  170846. 

  170847.   fts3tokResetCursor(pCsr);

  170848.   sqlite3_free(pCsr);

  170849.   return SQLITE_OK;

  170850. }

  170851. 

  170852. /*

  170853. ** xNext - Advance the cursor to the next row, if any.

  170854. */

  170855. static int fts3tokNextMethod(sqlite3_vtab_cursor *pCursor){

  170856.   Fts3tokCursor *pCsr = (Fts3tokCursor *)pCursor;

  170857.   Fts3tokTable *pTab = (Fts3tokTable *)(pCursor->pVtab);

  170858.   int rc;                         /* Return code */

  170859. 

  170860.   pCsr->iRowid++;

  170861.   rc = pTab->pMod->xNext(pCsr->pCsr,

  170862.       &pCsr->zToken, &pCsr->nToken,

  170863.       &pCsr->iStart, &pCsr->iEnd, &pCsr->iPos

  170864.   );

  170865. 

  170866.   if( rc!=SQLITE_OK ){

  170867.     fts3tokResetCursor(pCsr);

  170868.     if( rc==SQLITE_DONE ) rc = SQLITE_OK;

  170869.   }

  170870. 

  170871.   return rc;

  170872. }

  170873. 

  170874. /*

  170875. ** xFilter - Initialize a cursor to point at the start of its data.

  170876. */

  170877. static int fts3tokFilterMethod(

  170878.   sqlite3_vtab_cursor *pCursor,   /* The cursor used for this query */

  170879.   int idxNum,                     /* Strategy index */

  170880.   const char *idxStr,             /* Unused */

  170881.   int nVal,                       /* Number of elements in apVal */

  170882.   sqlite3_value **apVal           /* Arguments for the indexing scheme */

  170883. ){

  170884.   int rc = SQLITE_ERROR;

  170885.   Fts3tokCursor *pCsr = (Fts3tokCursor *)pCursor;

  170886.   Fts3tokTable *pTab = (Fts3tokTable *)(pCursor->pVtab);

  170887.   UNUSED_PARAMETER(idxStr);

  170888.   UNUSED_PARAMETER(nVal);

  170889. 

  170890.   fts3tokResetCursor(pCsr);

  170891.   if( idxNum==1 ){

  170892.     const char *zByte = (const char *)sqlite3_value_text(apVal[0]);

  170893.     int nByte = sqlite3_value_bytes(apVal[0]);

  170894.     pCsr->zInput = sqlite3_malloc64(nByte+1);

  170895.     if( pCsr->zInput==0 ){

  170896.       rc = SQLITE_NOMEM;

  170897.     }else{

  170898.       memcpy(pCsr->zInput, zByte, nByte);

  170899.       pCsr->zInput[nByte] = 0;

  170900.       rc = pTab->pMod->xOpen(pTab->pTok, pCsr->zInput, nByte, &pCsr->pCsr);

  170901.       if( rc==SQLITE_OK ){

  170902.         pCsr->pCsr->pTokenizer = pTab->pTok;

  170903.       }

  170904.     }

  170905.   }

  170906. 

  170907.   if( rc!=SQLITE_OK ) return rc;

  170908.   return fts3tokNextMethod(pCursor);

  170909. }

  170910. 

  170911. /*

  170912. ** xEof - Return true if the cursor is at EOF, or false otherwise.

  170913. */

  170914. static int fts3tokEofMethod(sqlite3_vtab_cursor *pCursor){

  170915.   Fts3tokCursor *pCsr = (Fts3tokCursor *)pCursor;

  170916.   return (pCsr->zToken==0);

  170917. }

  170918. 

  170919. /*

  170920. ** xColumn - Return a column value.

  170921. */

  170922. static int fts3tokColumnMethod(

  170923.   sqlite3_vtab_cursor *pCursor,   /* Cursor to retrieve value from */

  170924.   sqlite3_context *pCtx,          /* Context for sqlite3_result_xxx() calls */

  170925.   int iCol                        /* Index of column to read value from */

  170926. ){

  170927.   Fts3tokCursor *pCsr = (Fts3tokCursor *)pCursor;

  170928. 

  170929.   /* CREATE TABLE x(input, token, start, end, position) */

  170930.   switch( iCol ){

  170931.     case 0:

  170932.       sqlite3_result_text(pCtx, pCsr->zInput, -1, SQLITE_TRANSIENT);

  170933.       break;

  170934.     case 1:

  170935.       sqlite3_result_text(pCtx, pCsr->zToken, pCsr->nToken, SQLITE_TRANSIENT);

  170936.       break;

  170937.     case 2:

  170938.       sqlite3_result_int(pCtx, pCsr->iStart);

  170939.       break;

  170940.     case 3:

  170941.       sqlite3_result_int(pCtx, pCsr->iEnd);

  170942.       break;

  170943.     default:

  170944.       assert( iCol==4 );

  170945.       sqlite3_result_int(pCtx, pCsr->iPos);

  170946.       break;

  170947.   }

  170948.   return SQLITE_OK;

  170949. }

  170950. 

  170951. /*

  170952. ** xRowid - Return the current rowid for the cursor.

  170953. */

  170954. static int fts3tokRowidMethod(

  170955.   sqlite3_vtab_cursor *pCursor,   /* Cursor to retrieve value from */

  170956.   sqlite_int64 *pRowid            /* OUT: Rowid value */

  170957. ){

  170958.   Fts3tokCursor *pCsr = (Fts3tokCursor *)pCursor;

  170959.   *pRowid = (sqlite3_int64)pCsr->iRowid;

  170960.   return SQLITE_OK;

  170961. }

  170962. 

  170963. /*

  170964. ** Register the fts3tok module with database connection db. Return SQLITE_OK

  170965. ** if successful or an error code if sqlite3_create_module() fails.

  170966. */

  170967. SQLITE_PRIVATE int sqlite3Fts3InitTok(sqlite3 *db, Fts3Hash *pHash){

  170968.   static const sqlite3_module fts3tok_module = {

  170969.      0,                           /* iVersion      */

  170970.      fts3tokConnectMethod,        /* xCreate       */

  170971.      fts3tokConnectMethod,        /* xConnect      */

  170972.      fts3tokBestIndexMethod,      /* xBestIndex    */

  170973.      fts3tokDisconnectMethod,     /* xDisconnect   */

  170974.      fts3tokDisconnectMethod,     /* xDestroy      */

  170975.      fts3tokOpenMethod,           /* xOpen         */

  170976.      fts3tokCloseMethod,          /* xClose        */

  170977.      fts3tokFilterMethod,         /* xFilter       */

  170978.      fts3tokNextMethod,           /* xNext         */

  170979.      fts3tokEofMethod,            /* xEof          */

  170980.      fts3tokColumnMethod,         /* xColumn       */

  170981.      fts3tokRowidMethod,          /* xRowid        */

  170982.      0,                           /* xUpdate       */

  170983.      0,                           /* xBegin        */

  170984.      0,                           /* xSync         */

  170985.      0,                           /* xCommit       */

  170986.      0,                           /* xRollback     */

  170987.      0,                           /* xFindFunction */

  170988.      0,                           /* xRename       */

  170989.      0,                           /* xSavepoint    */

  170990.      0,                           /* xRelease      */

  170991.      0,                           /* xRollbackTo   */

  170992.      0                            /* xShadowName   */

  170993.   };

  170994.   int rc;                         /* Return code */

  170995. 

  170996.   rc = sqlite3_create_module(db, "fts3tokenize", &fts3tok_module, (void*)pHash);

  170997.   return rc;

  170998. }

  170999. 

  171000. #endif /* !defined(SQLITE_CORE) || defined(SQLITE_ENABLE_FTS3) */

  171001. 

  171002. /************** End of fts3_tokenize_vtab.c **********************************/

  171003. /************** Begin file fts3_write.c **************************************/

  171004. /*

  171005. ** 2009 Oct 23

  171006. **

  171007. ** The author disclaims copyright to this source code.  In place of

  171008. ** a legal notice, here is a blessing:

  171009. **

  171010. **    May you do good and not evil.

  171011. **    May you find forgiveness for yourself and forgive others.

  171012. **    May you share freely, never taking more than you give.

  171013. **

  171014. ******************************************************************************

  171015. **

  171016. ** This file is part of the SQLite FTS3 extension module. Specifically,

  171017. ** this file contains code to insert, update and delete rows from FTS3

  171018. ** tables. It also contains code to merge FTS3 b-tree segments. Some

  171019. ** of the sub-routines used to merge segments are also used by the query 

  171020. ** code in fts3.c.

  171021. */

  171022. 

  171023. /* #include "fts3Int.h" */

  171024. #if !defined(SQLITE_CORE) || defined(SQLITE_ENABLE_FTS3)

  171025. 

  171026. /* #include <string.h> */

  171027. /* #include <assert.h> */

  171028. /* #include <stdlib.h> */

  171029. 

  171030. 

  171031. #define FTS_MAX_APPENDABLE_HEIGHT 16

  171032. 

  171033. /*

  171034. ** When full-text index nodes are loaded from disk, the buffer that they

  171035. ** are loaded into has the following number of bytes of padding at the end 

  171036. ** of it. i.e. if a full-text index node is 900 bytes in size, then a buffer

  171037. ** of 920 bytes is allocated for it.

  171038. **

  171039. ** This means that if we have a pointer into a buffer containing node data,

  171040. ** it is always safe to read up to two varints from it without risking an

  171041. ** overread, even if the node data is corrupted.

  171042. */

  171043. #define FTS3_NODE_PADDING (FTS3_VARINT_MAX*2)

  171044. 

  171045. /*

  171046. ** Under certain circumstances, b-tree nodes (doclists) can be loaded into

  171047. ** memory incrementally instead of all at once. This can be a big performance

  171048. ** win (reduced IO and CPU) if SQLite stops calling the virtual table xNext()

  171049. ** method before retrieving all query results (as may happen, for example,

  171050. ** if a query has a LIMIT clause).

  171051. **

  171052. ** Incremental loading is used for b-tree nodes FTS3_NODE_CHUNK_THRESHOLD 

  171053. ** bytes and larger. Nodes are loaded in chunks of FTS3_NODE_CHUNKSIZE bytes.

  171054. ** The code is written so that the hard lower-limit for each of these values 

  171055. ** is 1. Clearly such small values would be inefficient, but can be useful 

  171056. ** for testing purposes.

  171057. **

  171058. ** If this module is built with SQLITE_TEST defined, these constants may

  171059. ** be overridden at runtime for testing purposes. File fts3_test.c contains

  171060. ** a Tcl interface to read and write the values.

  171061. */

  171062. #ifdef SQLITE_TEST

  171063. int test_fts3_node_chunksize = (4*1024);

  171064. int test_fts3_node_chunk_threshold = (4*1024)*4;

  171065. # define FTS3_NODE_CHUNKSIZE       test_fts3_node_chunksize

  171066. # define FTS3_NODE_CHUNK_THRESHOLD test_fts3_node_chunk_threshold

  171067. #else

  171068. # define FTS3_NODE_CHUNKSIZE (4*1024) 

  171069. # define FTS3_NODE_CHUNK_THRESHOLD (FTS3_NODE_CHUNKSIZE*4)

  171070. #endif

  171071. 

  171072. /*

  171073. ** The two values that may be meaningfully bound to the :1 parameter in

  171074. ** statements SQL_REPLACE_STAT and SQL_SELECT_STAT.

  171075. */

  171076. #define FTS_STAT_DOCTOTAL      0

  171077. #define FTS_STAT_INCRMERGEHINT 1

  171078. #define FTS_STAT_AUTOINCRMERGE 2

  171079. 

  171080. /*

  171081. ** If FTS_LOG_MERGES is defined, call sqlite3_log() to report each automatic

  171082. ** and incremental merge operation that takes place. This is used for 

  171083. ** debugging FTS only, it should not usually be turned on in production

  171084. ** systems.

  171085. */

  171086. #ifdef FTS3_LOG_MERGES

  171087. static void fts3LogMerge(int nMerge, sqlite3_int64 iAbsLevel){

  171088.   sqlite3_log(SQLITE_OK, "%d-way merge from level %d", nMerge, (int)iAbsLevel);

  171089. }

  171090. #else

  171091. #define fts3LogMerge(x, y)

  171092. #endif

  171093. 

  171094. 

  171095. typedef struct PendingList PendingList;

  171096. typedef struct SegmentNode SegmentNode;

  171097. typedef struct SegmentWriter SegmentWriter;

  171098. 

  171099. /*

  171100. ** An instance of the following data structure is used to build doclists

  171101. ** incrementally. See function fts3PendingListAppend() for details.

  171102. */

  171103. struct PendingList {

  171104.   int nData;

  171105.   char *aData;

  171106.   int nSpace;

  171107.   sqlite3_int64 iLastDocid;

  171108.   sqlite3_int64 iLastCol;

  171109.   sqlite3_int64 iLastPos;

  171110. };

  171111. 

  171112. 

  171113. /*

  171114. ** Each cursor has a (possibly empty) linked list of the following objects.

  171115. */

  171116. struct Fts3DeferredToken {

  171117.   Fts3PhraseToken *pToken;        /* Pointer to corresponding expr token */

  171118.   int iCol;                       /* Column token must occur in */

  171119.   Fts3DeferredToken *pNext;       /* Next in list of deferred tokens */

  171120.   PendingList *pList;             /* Doclist is assembled here */

  171121. };

  171122. 

  171123. /*

  171124. ** An instance of this structure is used to iterate through the terms on

  171125. ** a contiguous set of segment b-tree leaf nodes. Although the details of

  171126. ** this structure are only manipulated by code in this file, opaque handles

  171127. ** of type Fts3SegReader* are also used by code in fts3.c to iterate through

  171128. ** terms when querying the full-text index. See functions:

  171129. **

  171130. **   sqlite3Fts3SegReaderNew()

  171131. **   sqlite3Fts3SegReaderFree()

  171132. **   sqlite3Fts3SegReaderIterate()

  171133. **

  171134. ** Methods used to manipulate Fts3SegReader structures:

  171135. **

  171136. **   fts3SegReaderNext()

  171137. **   fts3SegReaderFirstDocid()

  171138. **   fts3SegReaderNextDocid()

  171139. */

  171140. struct Fts3SegReader {

  171141.   int iIdx;                       /* Index within level, or 0x7FFFFFFF for PT */

  171142.   u8 bLookup;                     /* True for a lookup only */

  171143.   u8 rootOnly;                    /* True for a root-only reader */

  171144. 

  171145.   sqlite3_int64 iStartBlock;      /* Rowid of first leaf block to traverse */

  171146.   sqlite3_int64 iLeafEndBlock;    /* Rowid of final leaf block to traverse */

  171147.   sqlite3_int64 iEndBlock;        /* Rowid of final block in segment (or 0) */

  171148.   sqlite3_int64 iCurrentBlock;    /* Current leaf block (or 0) */

  171149. 

  171150.   char *aNode;                    /* Pointer to node data (or NULL) */

  171151.   int nNode;                      /* Size of buffer at aNode (or 0) */

  171152.   int nPopulate;                  /* If >0, bytes of buffer aNode[] loaded */

  171153.   sqlite3_blob *pBlob;            /* If not NULL, blob handle to read node */

  171154. 

  171155.   Fts3HashElem **ppNextElem;

  171156. 

  171157.   /* Variables set by fts3SegReaderNext(). These may be read directly

  171158.   ** by the caller. They are valid from the time SegmentReaderNew() returns

  171159.   ** until SegmentReaderNext() returns something other than SQLITE_OK

  171160.   ** (i.e. SQLITE_DONE).

  171161.   */

  171162.   int nTerm;                      /* Number of bytes in current term */

  171163.   char *zTerm;                    /* Pointer to current term */

  171164.   int nTermAlloc;                 /* Allocated size of zTerm buffer */

  171165.   char *aDoclist;                 /* Pointer to doclist of current entry */

  171166.   int nDoclist;                   /* Size of doclist in current entry */

  171167. 

  171168.   /* The following variables are used by fts3SegReaderNextDocid() to iterate 

  171169.   ** through the current doclist (aDoclist/nDoclist).

  171170.   */

  171171.   char *pOffsetList;

  171172.   int nOffsetList;                /* For descending pending seg-readers only */

  171173.   sqlite3_int64 iDocid;

  171174. };

  171175. 

  171176. #define fts3SegReaderIsPending(p) ((p)->ppNextElem!=0)

  171177. #define fts3SegReaderIsRootOnly(p) ((p)->rootOnly!=0)

  171178. 

  171179. /*

  171180. ** An instance of this structure is used to create a segment b-tree in the

  171181. ** database. The internal details of this type are only accessed by the

  171182. ** following functions:

  171183. **

  171184. **   fts3SegWriterAdd()

  171185. **   fts3SegWriterFlush()

  171186. **   fts3SegWriterFree()

  171187. */

  171188. struct SegmentWriter {

  171189.   SegmentNode *pTree;             /* Pointer to interior tree structure */

  171190.   sqlite3_int64 iFirst;           /* First slot in %_segments written */

  171191.   sqlite3_int64 iFree;            /* Next free slot in %_segments */

  171192.   char *zTerm;                    /* Pointer to previous term buffer */

  171193.   int nTerm;                      /* Number of bytes in zTerm */

  171194.   int nMalloc;                    /* Size of malloc'd buffer at zMalloc */

  171195.   char *zMalloc;                  /* Malloc'd space (possibly) used for zTerm */

  171196.   int nSize;                      /* Size of allocation at aData */

  171197.   int nData;                      /* Bytes of data in aData */

  171198.   char *aData;                    /* Pointer to block from malloc() */

  171199.   i64 nLeafData;                  /* Number of bytes of leaf data written */

  171200. };

  171201. 

  171202. /*

  171203. ** Type SegmentNode is used by the following three functions to create

  171204. ** the interior part of the segment b+-tree structures (everything except

  171205. ** the leaf nodes). These functions and type are only ever used by code

  171206. ** within the fts3SegWriterXXX() family of functions described above.

  171207. **

  171208. **   fts3NodeAddTerm()

  171209. **   fts3NodeWrite()

  171210. **   fts3NodeFree()

  171211. **

  171212. ** When a b+tree is written to the database (either as a result of a merge

  171213. ** or the pending-terms table being flushed), leaves are written into the 

  171214. ** database file as soon as they are completely populated. The interior of

  171215. ** the tree is assembled in memory and written out only once all leaves have

  171216. ** been populated and stored. This is Ok, as the b+-tree fanout is usually

  171217. ** very large, meaning that the interior of the tree consumes relatively 

  171218. ** little memory.

  171219. */

  171220. struct SegmentNode {

  171221.   SegmentNode *pParent;           /* Parent node (or NULL for root node) */

  171222.   SegmentNode *pRight;            /* Pointer to right-sibling */

  171223.   SegmentNode *pLeftmost;         /* Pointer to left-most node of this depth */

  171224.   int nEntry;                     /* Number of terms written to node so far */

  171225.   char *zTerm;                    /* Pointer to previous term buffer */

  171226.   int nTerm;                      /* Number of bytes in zTerm */

  171227.   int nMalloc;                    /* Size of malloc'd buffer at zMalloc */

  171228.   char *zMalloc;                  /* Malloc'd space (possibly) used for zTerm */

  171229.   int nData;                      /* Bytes of valid data so far */

  171230.   char *aData;                    /* Node data */

  171231. };

  171232. 

  171233. /*

  171234. ** Valid values for the second argument to fts3SqlStmt().

  171235. */

  171236. #define SQL_DELETE_CONTENT             0

  171237. #define SQL_IS_EMPTY                   1

  171238. #define SQL_DELETE_ALL_CONTENT         2 

  171239. #define SQL_DELETE_ALL_SEGMENTS        3

  171240. #define SQL_DELETE_ALL_SEGDIR          4

  171241. #define SQL_DELETE_ALL_DOCSIZE         5

  171242. #define SQL_DELETE_ALL_STAT            6

  171243. #define SQL_SELECT_CONTENT_BY_ROWID    7

  171244. #define SQL_NEXT_SEGMENT_INDEX         8

  171245. #define SQL_INSERT_SEGMENTS            9

  171246. #define SQL_NEXT_SEGMENTS_ID          10

  171247. #define SQL_INSERT_SEGDIR             11

  171248. #define SQL_SELECT_LEVEL              12

  171249. #define SQL_SELECT_LEVEL_RANGE        13

  171250. #define SQL_SELECT_LEVEL_COUNT        14

  171251. #define SQL_SELECT_SEGDIR_MAX_LEVEL   15

  171252. #define SQL_DELETE_SEGDIR_LEVEL       16

  171253. #define SQL_DELETE_SEGMENTS_RANGE     17

  171254. #define SQL_CONTENT_INSERT            18

  171255. #define SQL_DELETE_DOCSIZE            19

  171256. #define SQL_REPLACE_DOCSIZE           20

  171257. #define SQL_SELECT_DOCSIZE            21

  171258. #define SQL_SELECT_STAT               22

  171259. #define SQL_REPLACE_STAT              23

  171260. 

  171261. #define SQL_SELECT_ALL_PREFIX_LEVEL   24

  171262. #define SQL_DELETE_ALL_TERMS_SEGDIR   25

  171263. #define SQL_DELETE_SEGDIR_RANGE       26

  171264. #define SQL_SELECT_ALL_LANGID         27

  171265. #define SQL_FIND_MERGE_LEVEL          28

  171266. #define SQL_MAX_LEAF_NODE_ESTIMATE    29

  171267. #define SQL_DELETE_SEGDIR_ENTRY       30

  171268. #define SQL_SHIFT_SEGDIR_ENTRY        31

  171269. #define SQL_SELECT_SEGDIR             32

  171270. #define SQL_CHOMP_SEGDIR              33

  171271. #define SQL_SEGMENT_IS_APPENDABLE     34

  171272. #define SQL_SELECT_INDEXES            35

  171273. #define SQL_SELECT_MXLEVEL            36

  171274. 

  171275. #define SQL_SELECT_LEVEL_RANGE2       37

  171276. #define SQL_UPDATE_LEVEL_IDX          38

  171277. #define SQL_UPDATE_LEVEL              39

  171278. 

  171279. /*

  171280. ** This function is used to obtain an SQLite prepared statement handle

  171281. ** for the statement identified by the second argument. If successful,

  171282. ** *pp is set to the requested statement handle and SQLITE_OK returned.

  171283. ** Otherwise, an SQLite error code is returned and *pp is set to 0.

  171284. **

  171285. ** If argument apVal is not NULL, then it must point to an array with

  171286. ** at least as many entries as the requested statement has bound 

  171287. ** parameters. The values are bound to the statements parameters before

  171288. ** returning.

  171289. */

  171290. static int fts3SqlStmt(

  171291.   Fts3Table *p,                   /* Virtual table handle */

  171292.   int eStmt,                      /* One of the SQL_XXX constants above */

  171293.   sqlite3_stmt **pp,              /* OUT: Statement handle */

  171294.   sqlite3_value **apVal           /* Values to bind to statement */

  171295. ){

  171296.   const char *azSql[] = {

  171297. /* 0  */  "DELETE FROM %Q.'%q_content' WHERE rowid = ?",

  171298. /* 1  */  "SELECT NOT EXISTS(SELECT docid FROM %Q.'%q_content' WHERE rowid!=?)",

  171299. /* 2  */  "DELETE FROM %Q.'%q_content'",

  171300. /* 3  */  "DELETE FROM %Q.'%q_segments'",

  171301. /* 4  */  "DELETE FROM %Q.'%q_segdir'",

  171302. /* 5  */  "DELETE FROM %Q.'%q_docsize'",

  171303. /* 6  */  "DELETE FROM %Q.'%q_stat'",

  171304. /* 7  */  "SELECT %s WHERE rowid=?",

  171305. /* 8  */  "SELECT (SELECT max(idx) FROM %Q.'%q_segdir' WHERE level = ?) + 1",

  171306. /* 9  */  "REPLACE INTO %Q.'%q_segments'(blockid, block) VALUES(?, ?)",

  171307. /* 10 */  "SELECT coalesce((SELECT max(blockid) FROM %Q.'%q_segments') + 1, 1)",

  171308. /* 11 */  "REPLACE INTO %Q.'%q_segdir' VALUES(?,?,?,?,?,?)",

  171309. 

  171310.           /* Return segments in order from oldest to newest.*/ 

  171311. /* 12 */  "SELECT idx, start_block, leaves_end_block, end_block, root "

  171312.             "FROM %Q.'%q_segdir' WHERE level = ? ORDER BY idx ASC",

  171313. /* 13 */  "SELECT idx, start_block, leaves_end_block, end_block, root "

  171314.             "FROM %Q.'%q_segdir' WHERE level BETWEEN ? AND ?"

  171315.             "ORDER BY level DESC, idx ASC",

  171316. 

  171317. /* 14 */  "SELECT count(*) FROM %Q.'%q_segdir' WHERE level = ?",

  171318. /* 15 */  "SELECT max(level) FROM %Q.'%q_segdir' WHERE level BETWEEN ? AND ?",

  171319. 

  171320. /* 16 */  "DELETE FROM %Q.'%q_segdir' WHERE level = ?",

  171321. /* 17 */  "DELETE FROM %Q.'%q_segments' WHERE blockid BETWEEN ? AND ?",

  171322. /* 18 */  "INSERT INTO %Q.'%q_content' VALUES(%s)",

  171323. /* 19 */  "DELETE FROM %Q.'%q_docsize' WHERE docid = ?",

  171324. /* 20 */  "REPLACE INTO %Q.'%q_docsize' VALUES(?,?)",

  171325. /* 21 */  "SELECT size FROM %Q.'%q_docsize' WHERE docid=?",

  171326. /* 22 */  "SELECT value FROM %Q.'%q_stat' WHERE id=?",

  171327. /* 23 */  "REPLACE INTO %Q.'%q_stat' VALUES(?,?)",

  171328. /* 24 */  "",

  171329. /* 25 */  "",

  171330. 

  171331. /* 26 */ "DELETE FROM %Q.'%q_segdir' WHERE level BETWEEN ? AND ?",

  171332. /* 27 */ "SELECT ? UNION SELECT level / (1024 * ?) FROM %Q.'%q_segdir'",

  171333. 

  171334. /* This statement is used to determine which level to read the input from

  171335. ** when performing an incremental merge. It returns the absolute level number

  171336. ** of the oldest level in the db that contains at least ? segments. Or,

  171337. ** if no level in the FTS index contains more than ? segments, the statement

  171338. ** returns zero rows.  */

  171339. /* 28 */ "SELECT level, count(*) AS cnt FROM %Q.'%q_segdir' "

  171340.          "  GROUP BY level HAVING cnt>=?"

  171341.          "  ORDER BY (level %% 1024) ASC LIMIT 1",

  171342. 

  171343. /* Estimate the upper limit on the number of leaf nodes in a new segment

  171344. ** created by merging the oldest :2 segments from absolute level :1. See 

  171345. ** function sqlite3Fts3Incrmerge() for details.  */

  171346. /* 29 */ "SELECT 2 * total(1 + leaves_end_block - start_block) "

  171347.          "  FROM %Q.'%q_segdir' WHERE level = ? AND idx < ?",

  171348. 

  171349. /* SQL_DELETE_SEGDIR_ENTRY

  171350. **   Delete the %_segdir entry on absolute level :1 with index :2.  */

  171351. /* 30 */ "DELETE FROM %Q.'%q_segdir' WHERE level = ? AND idx = ?",

  171352. 

  171353. /* SQL_SHIFT_SEGDIR_ENTRY

  171354. **   Modify the idx value for the segment with idx=:3 on absolute level :2

  171355. **   to :1.  */

  171356. /* 31 */ "UPDATE %Q.'%q_segdir' SET idx = ? WHERE level=? AND idx=?",

  171357. 

  171358. /* SQL_SELECT_SEGDIR

  171359. **   Read a single entry from the %_segdir table. The entry from absolute 

  171360. **   level :1 with index value :2.  */

  171361. /* 32 */  "SELECT idx, start_block, leaves_end_block, end_block, root "

  171362.             "FROM %Q.'%q_segdir' WHERE level = ? AND idx = ?",

  171363. 

  171364. /* SQL_CHOMP_SEGDIR

  171365. **   Update the start_block (:1) and root (:2) fields of the %_segdir

  171366. **   entry located on absolute level :3 with index :4.  */

  171367. /* 33 */  "UPDATE %Q.'%q_segdir' SET start_block = ?, root = ?"

  171368.             "WHERE level = ? AND idx = ?",

  171369. 

  171370. /* SQL_SEGMENT_IS_APPENDABLE

  171371. **   Return a single row if the segment with end_block=? is appendable. Or

  171372. **   no rows otherwise.  */

  171373. /* 34 */  "SELECT 1 FROM %Q.'%q_segments' WHERE blockid=? AND block IS NULL",

  171374. 

  171375. /* SQL_SELECT_INDEXES

  171376. **   Return the list of valid segment indexes for absolute level ?  */

  171377. /* 35 */  "SELECT idx FROM %Q.'%q_segdir' WHERE level=? ORDER BY 1 ASC",

  171378. 

  171379. /* SQL_SELECT_MXLEVEL

  171380. **   Return the largest relative level in the FTS index or indexes.  */

  171381. /* 36 */  "SELECT max( level %% 1024 ) FROM %Q.'%q_segdir'",

  171382. 

  171383.           /* Return segments in order from oldest to newest.*/ 

  171384. /* 37 */  "SELECT level, idx, end_block "

  171385.             "FROM %Q.'%q_segdir' WHERE level BETWEEN ? AND ? "

  171386.             "ORDER BY level DESC, idx ASC",

  171387. 

  171388.           /* Update statements used while promoting segments */

  171389. /* 38 */  "UPDATE OR FAIL %Q.'%q_segdir' SET level=-1,idx=? "

  171390.             "WHERE level=? AND idx=?",

  171391. /* 39 */  "UPDATE OR FAIL %Q.'%q_segdir' SET level=? WHERE level=-1"

  171392. 

  171393.   };

  171394.   int rc = SQLITE_OK;

  171395.   sqlite3_stmt *pStmt;

  171396. 

  171397.   assert( SizeofArray(azSql)==SizeofArray(p->aStmt) );

  171398.   assert( eStmt<SizeofArray(azSql) && eStmt>=0 );

  171399.   

  171400.   pStmt = p->aStmt[eStmt];

  171401.   if( !pStmt ){

  171402.     int f = SQLITE_PREPARE_PERSISTENT|SQLITE_PREPARE_NO_VTAB;

  171403.     char *zSql;

  171404.     if( eStmt==SQL_CONTENT_INSERT ){

  171405.       zSql = sqlite3_mprintf(azSql[eStmt], p->zDb, p->zName, p->zWriteExprlist);

  171406.     }else if( eStmt==SQL_SELECT_CONTENT_BY_ROWID ){

  171407.       f &= ~SQLITE_PREPARE_NO_VTAB;

  171408.       zSql = sqlite3_mprintf(azSql[eStmt], p->zReadExprlist);

  171409.     }else{

  171410.       zSql = sqlite3_mprintf(azSql[eStmt], p->zDb, p->zName);

  171411.     }

  171412.     if( !zSql ){

  171413.       rc = SQLITE_NOMEM;

  171414.     }else{

  171415.       rc = sqlite3_prepare_v3(p->db, zSql, -1, f, &pStmt, NULL);

  171416.       sqlite3_free(zSql);

  171417.       assert( rc==SQLITE_OK || pStmt==0 );

  171418.       p->aStmt[eStmt] = pStmt;

  171419.     }

  171420.   }

  171421.   if( apVal ){

  171422.     int i;

  171423.     int nParam = sqlite3_bind_parameter_count(pStmt);

  171424.     for(i=0; rc==SQLITE_OK && i<nParam; i++){

  171425.       rc = sqlite3_bind_value(pStmt, i+1, apVal[i]);

  171426.     }

  171427.   }

  171428.   *pp = pStmt;

  171429.   return rc;

  171430. }

  171431. 

  171432. 

  171433. static int fts3SelectDocsize(

  171434.   Fts3Table *pTab,                /* FTS3 table handle */

  171435.   sqlite3_int64 iDocid,           /* Docid to bind for SQL_SELECT_DOCSIZE */

  171436.   sqlite3_stmt **ppStmt           /* OUT: Statement handle */

  171437. ){

  171438.   sqlite3_stmt *pStmt = 0;        /* Statement requested from fts3SqlStmt() */

  171439.   int rc;                         /* Return code */

  171440. 

  171441.   rc = fts3SqlStmt(pTab, SQL_SELECT_DOCSIZE, &pStmt, 0);

  171442.   if( rc==SQLITE_OK ){

  171443.     sqlite3_bind_int64(pStmt, 1, iDocid);

  171444.     rc = sqlite3_step(pStmt);

  171445.     if( rc!=SQLITE_ROW || sqlite3_column_type(pStmt, 0)!=SQLITE_BLOB ){

  171446.       rc = sqlite3_reset(pStmt);

  171447.       if( rc==SQLITE_OK ) rc = FTS_CORRUPT_VTAB;

  171448.       pStmt = 0;

  171449.     }else{

  171450.       rc = SQLITE_OK;

  171451.     }

  171452.   }

  171453. 

  171454.   *ppStmt = pStmt;

  171455.   return rc;

  171456. }

  171457. 

  171458. SQLITE_PRIVATE int sqlite3Fts3SelectDoctotal(

  171459.   Fts3Table *pTab,                /* Fts3 table handle */

  171460.   sqlite3_stmt **ppStmt           /* OUT: Statement handle */

  171461. ){

  171462.   sqlite3_stmt *pStmt = 0;

  171463.   int rc;

  171464.   rc = fts3SqlStmt(pTab, SQL_SELECT_STAT, &pStmt, 0);

  171465.   if( rc==SQLITE_OK ){

  171466.     sqlite3_bind_int(pStmt, 1, FTS_STAT_DOCTOTAL);

  171467.     if( sqlite3_step(pStmt)!=SQLITE_ROW

  171468.      || sqlite3_column_type(pStmt, 0)!=SQLITE_BLOB

  171469.     ){

  171470.       rc = sqlite3_reset(pStmt);

  171471.       if( rc==SQLITE_OK ) rc = FTS_CORRUPT_VTAB;

  171472.       pStmt = 0;

  171473.     }

  171474.   }

  171475.   *ppStmt = pStmt;

  171476.   return rc;

  171477. }

  171478. 

  171479. SQLITE_PRIVATE int sqlite3Fts3SelectDocsize(

  171480.   Fts3Table *pTab,                /* Fts3 table handle */

  171481.   sqlite3_int64 iDocid,           /* Docid to read size data for */

  171482.   sqlite3_stmt **ppStmt           /* OUT: Statement handle */

  171483. ){

  171484.   return fts3SelectDocsize(pTab, iDocid, ppStmt);

  171485. }

  171486. 

  171487. /*

  171488. ** Similar to fts3SqlStmt(). Except, after binding the parameters in

  171489. ** array apVal[] to the SQL statement identified by eStmt, the statement

  171490. ** is executed.

  171491. **

  171492. ** Returns SQLITE_OK if the statement is successfully executed, or an

  171493. ** SQLite error code otherwise.

  171494. */

  171495. static void fts3SqlExec(

  171496.   int *pRC,                /* Result code */

  171497.   Fts3Table *p,            /* The FTS3 table */

  171498.   int eStmt,               /* Index of statement to evaluate */

  171499.   sqlite3_value **apVal    /* Parameters to bind */

  171500. ){

  171501.   sqlite3_stmt *pStmt;

  171502.   int rc;

  171503.   if( *pRC ) return;

  171504.   rc = fts3SqlStmt(p, eStmt, &pStmt, apVal); 

  171505.   if( rc==SQLITE_OK ){

  171506.     sqlite3_step(pStmt);

  171507.     rc = sqlite3_reset(pStmt);

  171508.   }

  171509.   *pRC = rc;

  171510. }

  171511. 

  171512. 

  171513. /*

  171514. ** This function ensures that the caller has obtained an exclusive 

  171515. ** shared-cache table-lock on the %_segdir table. This is required before 

  171516. ** writing data to the fts3 table. If this lock is not acquired first, then

  171517. ** the caller may end up attempting to take this lock as part of committing

  171518. ** a transaction, causing SQLite to return SQLITE_LOCKED or 

  171519. ** LOCKED_SHAREDCACHEto a COMMIT command.

  171520. **

  171521. ** It is best to avoid this because if FTS3 returns any error when 

  171522. ** committing a transaction, the whole transaction will be rolled back. 

  171523. ** And this is not what users expect when they get SQLITE_LOCKED_SHAREDCACHE. 

  171524. ** It can still happen if the user locks the underlying tables directly 

  171525. ** instead of accessing them via FTS.

  171526. */

  171527. static int fts3Writelock(Fts3Table *p){

  171528.   int rc = SQLITE_OK;

  171529.   

  171530.   if( p->nPendingData==0 ){

  171531.     sqlite3_stmt *pStmt;

  171532.     rc = fts3SqlStmt(p, SQL_DELETE_SEGDIR_LEVEL, &pStmt, 0);

  171533.     if( rc==SQLITE_OK ){

  171534.       sqlite3_bind_null(pStmt, 1);

  171535.       sqlite3_step(pStmt);

  171536.       rc = sqlite3_reset(pStmt);

  171537.     }

  171538.   }

  171539. 

  171540.   return rc;

  171541. }

  171542. 

  171543. /*

  171544. ** FTS maintains a separate indexes for each language-id (a 32-bit integer).

  171545. ** Within each language id, a separate index is maintained to store the

  171546. ** document terms, and each configured prefix size (configured the FTS 

  171547. ** "prefix=" option). And each index consists of multiple levels ("relative

  171548. ** levels").

  171549. **

  171550. ** All three of these values (the language id, the specific index and the

  171551. ** level within the index) are encoded in 64-bit integer values stored

  171552. ** in the %_segdir table on disk. This function is used to convert three

  171553. ** separate component values into the single 64-bit integer value that

  171554. ** can be used to query the %_segdir table.

  171555. **

  171556. ** Specifically, each language-id/index combination is allocated 1024 

  171557. ** 64-bit integer level values ("absolute levels"). The main terms index

  171558. ** for language-id 0 is allocate values 0-1023. The first prefix index

  171559. ** (if any) for language-id 0 is allocated values 1024-2047. And so on.

  171560. ** Language 1 indexes are allocated immediately following language 0.

  171561. **

  171562. ** So, for a system with nPrefix prefix indexes configured, the block of

  171563. ** absolute levels that corresponds to language-id iLangid and index 

  171564. ** iIndex starts at absolute level ((iLangid * (nPrefix+1) + iIndex) * 1024).

  171565. */

  171566. static sqlite3_int64 getAbsoluteLevel(

  171567.   Fts3Table *p,                   /* FTS3 table handle */

  171568.   int iLangid,                    /* Language id */

  171569.   int iIndex,                     /* Index in p->aIndex[] */

  171570.   int iLevel                      /* Level of segments */

  171571. ){

  171572.   sqlite3_int64 iBase;            /* First absolute level for iLangid/iIndex */

  171573.   assert_fts3_nc( iLangid>=0 );

  171574.   assert( p->nIndex>0 );

  171575.   assert( iIndex>=0 && iIndex<p->nIndex );

  171576. 

  171577.   iBase = ((sqlite3_int64)iLangid * p->nIndex + iIndex) * FTS3_SEGDIR_MAXLEVEL;

  171578.   return iBase + iLevel;

  171579. }

  171580. 

  171581. /*

  171582. ** Set *ppStmt to a statement handle that may be used to iterate through

  171583. ** all rows in the %_segdir table, from oldest to newest. If successful,

  171584. ** return SQLITE_OK. If an error occurs while preparing the statement, 

  171585. ** return an SQLite error code.

  171586. **

  171587. ** There is only ever one instance of this SQL statement compiled for

  171588. ** each FTS3 table.

  171589. **

  171590. ** The statement returns the following columns from the %_segdir table:

  171591. **

  171592. **   0: idx

  171593. **   1: start_block

  171594. **   2: leaves_end_block

  171595. **   3: end_block

  171596. **   4: root

  171597. */

  171598. SQLITE_PRIVATE int sqlite3Fts3AllSegdirs(

  171599.   Fts3Table *p,                   /* FTS3 table */

  171600.   int iLangid,                    /* Language being queried */

  171601.   int iIndex,                     /* Index for p->aIndex[] */

  171602.   int iLevel,                     /* Level to select (relative level) */

  171603.   sqlite3_stmt **ppStmt           /* OUT: Compiled statement */

  171604. ){

  171605.   int rc;

  171606.   sqlite3_stmt *pStmt = 0;

  171607. 

  171608.   assert( iLevel==FTS3_SEGCURSOR_ALL || iLevel>=0 );

  171609.   assert( iLevel<FTS3_SEGDIR_MAXLEVEL );

  171610.   assert( iIndex>=0 && iIndex<p->nIndex );

  171611. 

  171612.   if( iLevel<0 ){

  171613.     /* "SELECT * FROM %_segdir WHERE level BETWEEN ? AND ? ORDER BY ..." */

  171614.     rc = fts3SqlStmt(p, SQL_SELECT_LEVEL_RANGE, &pStmt, 0);

  171615.     if( rc==SQLITE_OK ){ 

  171616.       sqlite3_bind_int64(pStmt, 1, getAbsoluteLevel(p, iLangid, iIndex, 0));

  171617.       sqlite3_bind_int64(pStmt, 2, 

  171618.           getAbsoluteLevel(p, iLangid, iIndex, FTS3_SEGDIR_MAXLEVEL-1)

  171619.       );

  171620.     }

  171621.   }else{

  171622.     /* "SELECT * FROM %_segdir WHERE level = ? ORDER BY ..." */

  171623.     rc = fts3SqlStmt(p, SQL_SELECT_LEVEL, &pStmt, 0);

  171624.     if( rc==SQLITE_OK ){ 

  171625.       sqlite3_bind_int64(pStmt, 1, getAbsoluteLevel(p, iLangid, iIndex,iLevel));

  171626.     }

  171627.   }

  171628.   *ppStmt = pStmt;

  171629.   return rc;

  171630. }

  171631. 

  171632. 

  171633. /*

  171634. ** Append a single varint to a PendingList buffer. SQLITE_OK is returned

  171635. ** if successful, or an SQLite error code otherwise.

  171636. **

  171637. ** This function also serves to allocate the PendingList structure itself.

  171638. ** For example, to create a new PendingList structure containing two

  171639. ** varints:

  171640. **

  171641. **   PendingList *p = 0;

  171642. **   fts3PendingListAppendVarint(&p, 1);

  171643. **   fts3PendingListAppendVarint(&p, 2);

  171644. */

  171645. static int fts3PendingListAppendVarint(

  171646.   PendingList **pp,               /* IN/OUT: Pointer to PendingList struct */

  171647.   sqlite3_int64 i                 /* Value to append to data */

  171648. ){

  171649.   PendingList *p = *pp;

  171650. 

  171651.   /* Allocate or grow the PendingList as required. */

  171652.   if( !p ){

  171653.     p = sqlite3_malloc(sizeof(*p) + 100);

  171654.     if( !p ){

  171655.       return SQLITE_NOMEM;

  171656.     }

  171657.     p->nSpace = 100;

  171658.     p->aData = (char *)&p[1];

  171659.     p->nData = 0;

  171660.   }

  171661.   else if( p->nData+FTS3_VARINT_MAX+1>p->nSpace ){

  171662.     int nNew = p->nSpace * 2;

  171663.     p = sqlite3_realloc(p, sizeof(*p) + nNew);

  171664.     if( !p ){

  171665.       sqlite3_free(*pp);

  171666.       *pp = 0;

  171667.       return SQLITE_NOMEM;

  171668.     }

  171669.     p->nSpace = nNew;

  171670.     p->aData = (char *)&p[1];

  171671.   }

  171672. 

  171673.   /* Append the new serialized varint to the end of the list. */

  171674.   p->nData += sqlite3Fts3PutVarint(&p->aData[p->nData], i);

  171675.   p->aData[p->nData] = '\0';

  171676.   *pp = p;

  171677.   return SQLITE_OK;

  171678. }

  171679. 

  171680. /*

  171681. ** Add a docid/column/position entry to a PendingList structure. Non-zero

  171682. ** is returned if the structure is sqlite3_realloced as part of adding

  171683. ** the entry. Otherwise, zero.

  171684. **

  171685. ** If an OOM error occurs, *pRc is set to SQLITE_NOMEM before returning.

  171686. ** Zero is always returned in this case. Otherwise, if no OOM error occurs,

  171687. ** it is set to SQLITE_OK.

  171688. */

  171689. static int fts3PendingListAppend(

  171690.   PendingList **pp,               /* IN/OUT: PendingList structure */

  171691.   sqlite3_int64 iDocid,           /* Docid for entry to add */

  171692.   sqlite3_int64 iCol,             /* Column for entry to add */

  171693.   sqlite3_int64 iPos,             /* Position of term for entry to add */

  171694.   int *pRc                        /* OUT: Return code */

  171695. ){

  171696.   PendingList *p = *pp;

  171697.   int rc = SQLITE_OK;

  171698. 

  171699.   assert( !p || p->iLastDocid<=iDocid );

  171700. 

  171701.   if( !p || p->iLastDocid!=iDocid ){

  171702.     sqlite3_int64 iDelta = iDocid - (p ? p->iLastDocid : 0);

  171703.     if( p ){

  171704.       assert( p->nData<p->nSpace );

  171705.       assert( p->aData[p->nData]==0 );

  171706.       p->nData++;

  171707.     }

  171708.     if( SQLITE_OK!=(rc = fts3PendingListAppendVarint(&p, iDelta)) ){

  171709.       goto pendinglistappend_out;

  171710.     }

  171711.     p->iLastCol = -1;

  171712.     p->iLastPos = 0;

  171713.     p->iLastDocid = iDocid;

  171714.   }

  171715.   if( iCol>0 && p->iLastCol!=iCol ){

  171716.     if( SQLITE_OK!=(rc = fts3PendingListAppendVarint(&p, 1))

  171717.      || SQLITE_OK!=(rc = fts3PendingListAppendVarint(&p, iCol))

  171718.     ){

  171719.       goto pendinglistappend_out;

  171720.     }

  171721.     p->iLastCol = iCol;

  171722.     p->iLastPos = 0;

  171723.   }

  171724.   if( iCol>=0 ){

  171725.     assert( iPos>p->iLastPos || (iPos==0 && p->iLastPos==0) );

  171726.     rc = fts3PendingListAppendVarint(&p, 2+iPos-p->iLastPos);

  171727.     if( rc==SQLITE_OK ){

  171728.       p->iLastPos = iPos;

  171729.     }

  171730.   }

  171731. 

  171732.  pendinglistappend_out:

  171733.   *pRc = rc;

  171734.   if( p!=*pp ){

  171735.     *pp = p;

  171736.     return 1;

  171737.   }

  171738.   return 0;

  171739. }

  171740. 

  171741. /*

  171742. ** Free a PendingList object allocated by fts3PendingListAppend().

  171743. */

  171744. static void fts3PendingListDelete(PendingList *pList){

  171745.   sqlite3_free(pList);

  171746. }

  171747. 

  171748. /*

  171749. ** Add an entry to one of the pending-terms hash tables.

  171750. */

  171751. static int fts3PendingTermsAddOne(

  171752.   Fts3Table *p,

  171753.   int iCol,

  171754.   int iPos,

  171755.   Fts3Hash *pHash,                /* Pending terms hash table to add entry to */

  171756.   const char *zToken,

  171757.   int nToken

  171758. ){

  171759.   PendingList *pList;

  171760.   int rc = SQLITE_OK;

  171761. 

  171762.   pList = (PendingList *)fts3HashFind(pHash, zToken, nToken);

  171763.   if( pList ){

  171764.     p->nPendingData -= (pList->nData + nToken + sizeof(Fts3HashElem));

  171765.   }

  171766.   if( fts3PendingListAppend(&pList, p->iPrevDocid, iCol, iPos, &rc) ){

  171767.     if( pList==fts3HashInsert(pHash, zToken, nToken, pList) ){

  171768.       /* Malloc failed while inserting the new entry. This can only 

  171769.       ** happen if there was no previous entry for this token.

  171770.       */

  171771.       assert( 0==fts3HashFind(pHash, zToken, nToken) );

  171772.       sqlite3_free(pList);

  171773.       rc = SQLITE_NOMEM;

  171774.     }

  171775.   }

  171776.   if( rc==SQLITE_OK ){

  171777.     p->nPendingData += (pList->nData + nToken + sizeof(Fts3HashElem));

  171778.   }

  171779.   return rc;

  171780. }

  171781. 

  171782. /*

  171783. ** Tokenize the nul-terminated string zText and add all tokens to the

  171784. ** pending-terms hash-table. The docid used is that currently stored in

  171785. ** p->iPrevDocid, and the column is specified by argument iCol.

  171786. **

  171787. ** If successful, SQLITE_OK is returned. Otherwise, an SQLite error code.

  171788. */

  171789. static int fts3PendingTermsAdd(

  171790.   Fts3Table *p,                   /* Table into which text will be inserted */

  171791.   int iLangid,                    /* Language id to use */

  171792.   const char *zText,              /* Text of document to be inserted */

  171793.   int iCol,                       /* Column into which text is being inserted */

  171794.   u32 *pnWord                     /* IN/OUT: Incr. by number tokens inserted */

  171795. ){

  171796.   int rc;

  171797.   int iStart = 0;

  171798.   int iEnd = 0;

  171799.   int iPos = 0;

  171800.   int nWord = 0;

  171801. 

  171802.   char const *zToken;

  171803.   int nToken = 0;

  171804. 

  171805.   sqlite3_tokenizer *pTokenizer = p->pTokenizer;

  171806.   sqlite3_tokenizer_module const *pModule = pTokenizer->pModule;

  171807.   sqlite3_tokenizer_cursor *pCsr;

  171808.   int (*xNext)(sqlite3_tokenizer_cursor *pCursor,

  171809.       const char**,int*,int*,int*,int*);

  171810. 

  171811.   assert( pTokenizer && pModule );

  171812. 

  171813.   /* If the user has inserted a NULL value, this function may be called with

  171814.   ** zText==0. In this case, add zero token entries to the hash table and 

  171815.   ** return early. */

  171816.   if( zText==0 ){

  171817.     *pnWord = 0;

  171818.     return SQLITE_OK;

  171819.   }

  171820. 

  171821.   rc = sqlite3Fts3OpenTokenizer(pTokenizer, iLangid, zText, -1, &pCsr);

  171822.   if( rc!=SQLITE_OK ){

  171823.     return rc;

  171824.   }

  171825. 

  171826.   xNext = pModule->xNext;

  171827.   while( SQLITE_OK==rc

  171828.       && SQLITE_OK==(rc = xNext(pCsr, &zToken, &nToken, &iStart, &iEnd, &iPos))

  171829.   ){

  171830.     int i;

  171831.     if( iPos>=nWord ) nWord = iPos+1;

  171832. 

  171833.     /* Positions cannot be negative; we use -1 as a terminator internally.

  171834.     ** Tokens must have a non-zero length.

  171835.     */

  171836.     if( iPos<0 || !zToken || nToken<=0 ){

  171837.       rc = SQLITE_ERROR;

  171838.       break;

  171839.     }

  171840. 

  171841.     /* Add the term to the terms index */

  171842.     rc = fts3PendingTermsAddOne(

  171843.         p, iCol, iPos, &p->aIndex[0].hPending, zToken, nToken

  171844.     );

  171845.     

  171846.     /* Add the term to each of the prefix indexes that it is not too 

  171847.     ** short for. */

  171848.     for(i=1; rc==SQLITE_OK && i<p->nIndex; i++){

  171849.       struct Fts3Index *pIndex = &p->aIndex[i];

  171850.       if( nToken<pIndex->nPrefix ) continue;

  171851.       rc = fts3PendingTermsAddOne(

  171852.           p, iCol, iPos, &pIndex->hPending, zToken, pIndex->nPrefix

  171853.       );

  171854.     }

  171855.   }

  171856. 

  171857.   pModule->xClose(pCsr);

  171858.   *pnWord += nWord;

  171859.   return (rc==SQLITE_DONE ? SQLITE_OK : rc);

  171860. }

  171861. 

  171862. /* 

  171863. ** Calling this function indicates that subsequent calls to 

  171864. ** fts3PendingTermsAdd() are to add term/position-list pairs for the

  171865. ** contents of the document with docid iDocid.

  171866. */

  171867. static int fts3PendingTermsDocid(

  171868.   Fts3Table *p,                   /* Full-text table handle */

  171869.   int bDelete,                    /* True if this op is a delete */

  171870.   int iLangid,                    /* Language id of row being written */

  171871.   sqlite_int64 iDocid             /* Docid of row being written */

  171872. ){

  171873.   assert( iLangid>=0 );

  171874.   assert( bDelete==1 || bDelete==0 );

  171875. 

  171876.   /* TODO(shess) Explore whether partially flushing the buffer on

  171877.   ** forced-flush would provide better performance.  I suspect that if

  171878.   ** we ordered the doclists by size and flushed the largest until the

  171879.   ** buffer was half empty, that would let the less frequent terms

  171880.   ** generate longer doclists.

  171881.   */

  171882.   if( iDocid<p->iPrevDocid 

  171883.    || (iDocid==p->iPrevDocid && p->bPrevDelete==0)

  171884.    || p->iPrevLangid!=iLangid

  171885.    || p->nPendingData>p->nMaxPendingData 

  171886.   ){

  171887.     int rc = sqlite3Fts3PendingTermsFlush(p);

  171888.     if( rc!=SQLITE_OK ) return rc;

  171889.   }

  171890.   p->iPrevDocid = iDocid;

  171891.   p->iPrevLangid = iLangid;

  171892.   p->bPrevDelete = bDelete;

  171893.   return SQLITE_OK;

  171894. }

  171895. 

  171896. /*

  171897. ** Discard the contents of the pending-terms hash tables. 

  171898. */

  171899. SQLITE_PRIVATE void sqlite3Fts3PendingTermsClear(Fts3Table *p){

  171900.   int i;

  171901.   for(i=0; i<p->nIndex; i++){

  171902.     Fts3HashElem *pElem;

  171903.     Fts3Hash *pHash = &p->aIndex[i].hPending;

  171904.     for(pElem=fts3HashFirst(pHash); pElem; pElem=fts3HashNext(pElem)){

  171905.       PendingList *pList = (PendingList *)fts3HashData(pElem);

  171906.       fts3PendingListDelete(pList);

  171907.     }

  171908.     fts3HashClear(pHash);

  171909.   }

  171910.   p->nPendingData = 0;

  171911. }

  171912. 

  171913. /*

  171914. ** This function is called by the xUpdate() method as part of an INSERT

  171915. ** operation. It adds entries for each term in the new record to the

  171916. ** pendingTerms hash table.

  171917. **

  171918. ** Argument apVal is the same as the similarly named argument passed to

  171919. ** fts3InsertData(). Parameter iDocid is the docid of the new row.

  171920. */

  171921. static int fts3InsertTerms(

  171922.   Fts3Table *p, 

  171923.   int iLangid, 

  171924.   sqlite3_value **apVal, 

  171925.   u32 *aSz

  171926. ){

  171927.   int i;                          /* Iterator variable */

  171928.   for(i=2; i<p->nColumn+2; i++){

  171929.     int iCol = i-2;

  171930.     if( p->abNotindexed[iCol]==0 ){

  171931.       const char *zText = (const char *)sqlite3_value_text(apVal[i]);

  171932.       int rc = fts3PendingTermsAdd(p, iLangid, zText, iCol, &aSz[iCol]);

  171933.       if( rc!=SQLITE_OK ){

  171934.         return rc;

  171935.       }

  171936.       aSz[p->nColumn] += sqlite3_value_bytes(apVal[i]);

  171937.     }

  171938.   }

  171939.   return SQLITE_OK;

  171940. }

  171941. 

  171942. /*

  171943. ** This function is called by the xUpdate() method for an INSERT operation.

  171944. ** The apVal parameter is passed a copy of the apVal argument passed by

  171945. ** SQLite to the xUpdate() method. i.e:

  171946. **

  171947. **   apVal[0]                Not used for INSERT.

  171948. **   apVal[1]                rowid

  171949. **   apVal[2]                Left-most user-defined column

  171950. **   ...

  171951. **   apVal[p->nColumn+1]     Right-most user-defined column

  171952. **   apVal[p->nColumn+2]     Hidden column with same name as table

  171953. **   apVal[p->nColumn+3]     Hidden "docid" column (alias for rowid)

  171954. **   apVal[p->nColumn+4]     Hidden languageid column

  171955. */

  171956. static int fts3InsertData(

  171957.   Fts3Table *p,                   /* Full-text table */

  171958.   sqlite3_value **apVal,          /* Array of values to insert */

  171959.   sqlite3_int64 *piDocid          /* OUT: Docid for row just inserted */

  171960. ){

  171961.   int rc;                         /* Return code */

  171962.   sqlite3_stmt *pContentInsert;   /* INSERT INTO %_content VALUES(...) */

  171963. 

  171964.   if( p->zContentTbl ){

  171965.     sqlite3_value *pRowid = apVal[p->nColumn+3];

  171966.     if( sqlite3_value_type(pRowid)==SQLITE_NULL ){

  171967.       pRowid = apVal[1];

  171968.     }

  171969.     if( sqlite3_value_type(pRowid)!=SQLITE_INTEGER ){

  171970.       return SQLITE_CONSTRAINT;

  171971.     }

  171972.     *piDocid = sqlite3_value_int64(pRowid);

  171973.     return SQLITE_OK;

  171974.   }

  171975. 

  171976.   /* Locate the statement handle used to insert data into the %_content

  171977.   ** table. The SQL for this statement is:

  171978.   **

  171979.   **   INSERT INTO %_content VALUES(?, ?, ?, ...)

  171980.   **

  171981.   ** The statement features N '?' variables, where N is the number of user

  171982.   ** defined columns in the FTS3 table, plus one for the docid field.

  171983.   */

  171984.   rc = fts3SqlStmt(p, SQL_CONTENT_INSERT, &pContentInsert, &apVal[1]);

  171985.   if( rc==SQLITE_OK && p->zLanguageid ){

  171986.     rc = sqlite3_bind_int(

  171987.         pContentInsert, p->nColumn+2, 

  171988.         sqlite3_value_int(apVal[p->nColumn+4])

  171989.     );

  171990.   }

  171991.   if( rc!=SQLITE_OK ) return rc;

  171992. 

  171993.   /* There is a quirk here. The users INSERT statement may have specified

  171994.   ** a value for the "rowid" field, for the "docid" field, or for both.

  171995.   ** Which is a problem, since "rowid" and "docid" are aliases for the

  171996.   ** same value. For example:

  171997.   **

  171998.   **   INSERT INTO fts3tbl(rowid, docid) VALUES(1, 2);

  171999.   **

  172000.   ** In FTS3, this is an error. It is an error to specify non-NULL values

  172001.   ** for both docid and some other rowid alias.

  172002.   */

  172003.   if( SQLITE_NULL!=sqlite3_value_type(apVal[3+p->nColumn]) ){

  172004.     if( SQLITE_NULL==sqlite3_value_type(apVal[0])

  172005.      && SQLITE_NULL!=sqlite3_value_type(apVal[1])

  172006.     ){

  172007.       /* A rowid/docid conflict. */

  172008.       return SQLITE_ERROR;

  172009.     }

  172010.     rc = sqlite3_bind_value(pContentInsert, 1, apVal[3+p->nColumn]);

  172011.     if( rc!=SQLITE_OK ) return rc;

  172012.   }

  172013. 

  172014.   /* Execute the statement to insert the record. Set *piDocid to the 

  172015.   ** new docid value. 

  172016.   */

  172017.   sqlite3_step(pContentInsert);

  172018.   rc = sqlite3_reset(pContentInsert);

  172019. 

  172020.   *piDocid = sqlite3_last_insert_rowid(p->db);

  172021.   return rc;

  172022. }

  172023. 

  172024. 

  172025. 

  172026. /*

  172027. ** Remove all data from the FTS3 table. Clear the hash table containing

  172028. ** pending terms.

  172029. */

  172030. static int fts3DeleteAll(Fts3Table *p, int bContent){

  172031.   int rc = SQLITE_OK;             /* Return code */

  172032. 

  172033.   /* Discard the contents of the pending-terms hash table. */

  172034.   sqlite3Fts3PendingTermsClear(p);

  172035. 

  172036.   /* Delete everything from the shadow tables. Except, leave %_content as

  172037.   ** is if bContent is false.  */

  172038.   assert( p->zContentTbl==0 || bContent==0 );

  172039.   if( bContent ) fts3SqlExec(&rc, p, SQL_DELETE_ALL_CONTENT, 0);

  172040.   fts3SqlExec(&rc, p, SQL_DELETE_ALL_SEGMENTS, 0);

  172041.   fts3SqlExec(&rc, p, SQL_DELETE_ALL_SEGDIR, 0);

  172042.   if( p->bHasDocsize ){

  172043.     fts3SqlExec(&rc, p, SQL_DELETE_ALL_DOCSIZE, 0);

  172044.   }

  172045.   if( p->bHasStat ){

  172046.     fts3SqlExec(&rc, p, SQL_DELETE_ALL_STAT, 0);

  172047.   }

  172048.   return rc;

  172049. }

  172050. 

  172051. /*

  172052. **

  172053. */

  172054. static int langidFromSelect(Fts3Table *p, sqlite3_stmt *pSelect){

  172055.   int iLangid = 0;

  172056.   if( p->zLanguageid ) iLangid = sqlite3_column_int(pSelect, p->nColumn+1);

  172057.   return iLangid;

  172058. }

  172059. 

  172060. /*

  172061. ** The first element in the apVal[] array is assumed to contain the docid

  172062. ** (an integer) of a row about to be deleted. Remove all terms from the

  172063. ** full-text index.

  172064. */

  172065. static void fts3DeleteTerms( 

  172066.   int *pRC,               /* Result code */

  172067.   Fts3Table *p,           /* The FTS table to delete from */

  172068.   sqlite3_value *pRowid,  /* The docid to be deleted */

  172069.   u32 *aSz,               /* Sizes of deleted document written here */

  172070.   int *pbFound            /* OUT: Set to true if row really does exist */

  172071. ){

  172072.   int rc;

  172073.   sqlite3_stmt *pSelect;

  172074. 

  172075.   assert( *pbFound==0 );

  172076.   if( *pRC ) return;

  172077.   rc = fts3SqlStmt(p, SQL_SELECT_CONTENT_BY_ROWID, &pSelect, &pRowid);

  172078.   if( rc==SQLITE_OK ){

  172079.     if( SQLITE_ROW==sqlite3_step(pSelect) ){

  172080.       int i;

  172081.       int iLangid = langidFromSelect(p, pSelect);

  172082.       i64 iDocid = sqlite3_column_int64(pSelect, 0);

  172083.       rc = fts3PendingTermsDocid(p, 1, iLangid, iDocid);

  172084.       for(i=1; rc==SQLITE_OK && i<=p->nColumn; i++){

  172085.         int iCol = i-1;

  172086.         if( p->abNotindexed[iCol]==0 ){

  172087.           const char *zText = (const char *)sqlite3_column_text(pSelect, i);

  172088.           rc = fts3PendingTermsAdd(p, iLangid, zText, -1, &aSz[iCol]);

  172089.           aSz[p->nColumn] += sqlite3_column_bytes(pSelect, i);

  172090.         }

  172091.       }

  172092.       if( rc!=SQLITE_OK ){

  172093.         sqlite3_reset(pSelect);

  172094.         *pRC = rc;

  172095.         return;

  172096.       }

  172097.       *pbFound = 1;

  172098.     }

  172099.     rc = sqlite3_reset(pSelect);

  172100.   }else{

  172101.     sqlite3_reset(pSelect);

  172102.   }

  172103.   *pRC = rc;

  172104. }

  172105. 

  172106. /*

  172107. ** Forward declaration to account for the circular dependency between

  172108. ** functions fts3SegmentMerge() and fts3AllocateSegdirIdx().

  172109. */

  172110. static int fts3SegmentMerge(Fts3Table *, int, int, int);

  172111. 

  172112. /* 

  172113. ** This function allocates a new level iLevel index in the segdir table.

  172114. ** Usually, indexes are allocated within a level sequentially starting

  172115. ** with 0, so the allocated index is one greater than the value returned

  172116. ** by:

  172117. **

  172118. **   SELECT max(idx) FROM %_segdir WHERE level = :iLevel

  172119. **

  172120. ** However, if there are already FTS3_MERGE_COUNT indexes at the requested

  172121. ** level, they are merged into a single level (iLevel+1) segment and the 

  172122. ** allocated index is 0.

  172123. **

  172124. ** If successful, *piIdx is set to the allocated index slot and SQLITE_OK

  172125. ** returned. Otherwise, an SQLite error code is returned.

  172126. */

  172127. static int fts3AllocateSegdirIdx(

  172128.   Fts3Table *p, 

  172129.   int iLangid,                    /* Language id */

  172130.   int iIndex,                     /* Index for p->aIndex */

  172131.   int iLevel, 

  172132.   int *piIdx

  172133. ){

  172134.   int rc;                         /* Return Code */

  172135.   sqlite3_stmt *pNextIdx;         /* Query for next idx at level iLevel */

  172136.   int iNext = 0;                  /* Result of query pNextIdx */

  172137. 

  172138.   assert( iLangid>=0 );

  172139.   assert( p->nIndex>=1 );

  172140. 

  172141.   /* Set variable iNext to the next available segdir index at level iLevel. */

  172142.   rc = fts3SqlStmt(p, SQL_NEXT_SEGMENT_INDEX, &pNextIdx, 0);

  172143.   if( rc==SQLITE_OK ){

  172144.     sqlite3_bind_int64(

  172145.         pNextIdx, 1, getAbsoluteLevel(p, iLangid, iIndex, iLevel)

  172146.     );

  172147.     if( SQLITE_ROW==sqlite3_step(pNextIdx) ){

  172148.       iNext = sqlite3_column_int(pNextIdx, 0);

  172149.     }

  172150.     rc = sqlite3_reset(pNextIdx);

  172151.   }

  172152. 

  172153.   if( rc==SQLITE_OK ){

  172154.     /* If iNext is FTS3_MERGE_COUNT, indicating that level iLevel is already

  172155.     ** full, merge all segments in level iLevel into a single iLevel+1

  172156.     ** segment and allocate (newly freed) index 0 at level iLevel. Otherwise,

  172157.     ** if iNext is less than FTS3_MERGE_COUNT, allocate index iNext.

  172158.     */

  172159.     if( iNext>=FTS3_MERGE_COUNT ){

  172160.       fts3LogMerge(16, getAbsoluteLevel(p, iLangid, iIndex, iLevel));

  172161.       rc = fts3SegmentMerge(p, iLangid, iIndex, iLevel);

  172162.       *piIdx = 0;

  172163.     }else{

  172164.       *piIdx = iNext;

  172165.     }

  172166.   }

  172167. 

  172168.   return rc;

  172169. }

  172170. 

  172171. /*

  172172. ** The %_segments table is declared as follows:

  172173. **

  172174. **   CREATE TABLE %_segments(blockid INTEGER PRIMARY KEY, block BLOB)

  172175. **

  172176. ** This function reads data from a single row of the %_segments table. The

  172177. ** specific row is identified by the iBlockid parameter. If paBlob is not

  172178. ** NULL, then a buffer is allocated using sqlite3_malloc() and populated

  172179. ** with the contents of the blob stored in the "block" column of the 

  172180. ** identified table row is. Whether or not paBlob is NULL, *pnBlob is set

  172181. ** to the size of the blob in bytes before returning.

  172182. **

  172183. ** If an error occurs, or the table does not contain the specified row,

  172184. ** an SQLite error code is returned. Otherwise, SQLITE_OK is returned. If

  172185. ** paBlob is non-NULL, then it is the responsibility of the caller to

  172186. ** eventually free the returned buffer.

  172187. **

  172188. ** This function may leave an open sqlite3_blob* handle in the

  172189. ** Fts3Table.pSegments variable. This handle is reused by subsequent calls

  172190. ** to this function. The handle may be closed by calling the

  172191. ** sqlite3Fts3SegmentsClose() function. Reusing a blob handle is a handy

  172192. ** performance improvement, but the blob handle should always be closed

  172193. ** before control is returned to the user (to prevent a lock being held

  172194. ** on the database file for longer than necessary). Thus, any virtual table

  172195. ** method (xFilter etc.) that may directly or indirectly call this function

  172196. ** must call sqlite3Fts3SegmentsClose() before returning.

  172197. */

  172198. SQLITE_PRIVATE int sqlite3Fts3ReadBlock(

  172199.   Fts3Table *p,                   /* FTS3 table handle */

  172200.   sqlite3_int64 iBlockid,         /* Access the row with blockid=$iBlockid */

  172201.   char **paBlob,                  /* OUT: Blob data in malloc'd buffer */

  172202.   int *pnBlob,                    /* OUT: Size of blob data */

  172203.   int *pnLoad                     /* OUT: Bytes actually loaded */

  172204. ){

  172205.   int rc;                         /* Return code */

  172206. 

  172207.   /* pnBlob must be non-NULL. paBlob may be NULL or non-NULL. */

  172208.   assert( pnBlob );

  172209. 

  172210.   if( p->pSegments ){

  172211.     rc = sqlite3_blob_reopen(p->pSegments, iBlockid);

  172212.   }else{

  172213.     if( 0==p->zSegmentsTbl ){

  172214.       p->zSegmentsTbl = sqlite3_mprintf("%s_segments", p->zName);

  172215.       if( 0==p->zSegmentsTbl ) return SQLITE_NOMEM;

  172216.     }

  172217.     rc = sqlite3_blob_open(

  172218.        p->db, p->zDb, p->zSegmentsTbl, "block", iBlockid, 0, &p->pSegments

  172219.     );

  172220.   }

  172221. 

  172222.   if( rc==SQLITE_OK ){

  172223.     int nByte = sqlite3_blob_bytes(p->pSegments);

  172224.     *pnBlob = nByte;

  172225.     if( paBlob ){

  172226.       char *aByte = sqlite3_malloc(nByte + FTS3_NODE_PADDING);

  172227.       if( !aByte ){

  172228.         rc = SQLITE_NOMEM;

  172229.       }else{

  172230.         if( pnLoad && nByte>(FTS3_NODE_CHUNK_THRESHOLD) ){

  172231.           nByte = FTS3_NODE_CHUNKSIZE;

  172232.           *pnLoad = nByte;

  172233.         }

  172234.         rc = sqlite3_blob_read(p->pSegments, aByte, nByte, 0);

  172235.         memset(&aByte[nByte], 0, FTS3_NODE_PADDING);

  172236.         if( rc!=SQLITE_OK ){

  172237.           sqlite3_free(aByte);

  172238.           aByte = 0;

  172239.         }

  172240.       }

  172241.       *paBlob = aByte;

  172242.     }

  172243.   }

  172244. 

  172245.   return rc;

  172246. }

  172247. 

  172248. /*

  172249. ** Close the blob handle at p->pSegments, if it is open. See comments above

  172250. ** the sqlite3Fts3ReadBlock() function for details.

  172251. */

  172252. SQLITE_PRIVATE void sqlite3Fts3SegmentsClose(Fts3Table *p){

  172253.   sqlite3_blob_close(p->pSegments);

  172254.   p->pSegments = 0;

  172255. }

  172256.     

  172257. static int fts3SegReaderIncrRead(Fts3SegReader *pReader){

  172258.   int nRead;                      /* Number of bytes to read */

  172259.   int rc;                         /* Return code */

  172260. 

  172261.   nRead = MIN(pReader->nNode - pReader->nPopulate, FTS3_NODE_CHUNKSIZE);

  172262.   rc = sqlite3_blob_read(

  172263.       pReader->pBlob, 

  172264.       &pReader->aNode[pReader->nPopulate],

  172265.       nRead,

  172266.       pReader->nPopulate

  172267.   );

  172268. 

  172269.   if( rc==SQLITE_OK ){

  172270.     pReader->nPopulate += nRead;

  172271.     memset(&pReader->aNode[pReader->nPopulate], 0, FTS3_NODE_PADDING);

  172272.     if( pReader->nPopulate==pReader->nNode ){

  172273.       sqlite3_blob_close(pReader->pBlob);

  172274.       pReader->pBlob = 0;

  172275.       pReader->nPopulate = 0;

  172276.     }

  172277.   }

  172278.   return rc;

  172279. }

  172280. 

  172281. static int fts3SegReaderRequire(Fts3SegReader *pReader, char *pFrom, int nByte){

  172282.   int rc = SQLITE_OK;

  172283.   assert( !pReader->pBlob 

  172284.        || (pFrom>=pReader->aNode && pFrom<&pReader->aNode[pReader->nNode])

  172285.   );

  172286.   while( pReader->pBlob && rc==SQLITE_OK 

  172287.      &&  (pFrom - pReader->aNode + nByte)>pReader->nPopulate

  172288.   ){

  172289.     rc = fts3SegReaderIncrRead(pReader);

  172290.   }

  172291.   return rc;

  172292. }

  172293. 

  172294. /*

  172295. ** Set an Fts3SegReader cursor to point at EOF.

  172296. */

  172297. static void fts3SegReaderSetEof(Fts3SegReader *pSeg){

  172298.   if( !fts3SegReaderIsRootOnly(pSeg) ){

  172299.     sqlite3_free(pSeg->aNode);

  172300.     sqlite3_blob_close(pSeg->pBlob);

  172301.     pSeg->pBlob = 0;

  172302.   }

  172303.   pSeg->aNode = 0;

  172304. }

  172305. 

  172306. /*

  172307. ** Move the iterator passed as the first argument to the next term in the

  172308. ** segment. If successful, SQLITE_OK is returned. If there is no next term,

  172309. ** SQLITE_DONE. Otherwise, an SQLite error code.

  172310. */

  172311. static int fts3SegReaderNext(

  172312.   Fts3Table *p, 

  172313.   Fts3SegReader *pReader,

  172314.   int bIncr

  172315. ){

  172316.   int rc;                         /* Return code of various sub-routines */

  172317.   char *pNext;                    /* Cursor variable */

  172318.   int nPrefix;                    /* Number of bytes in term prefix */

  172319.   int nSuffix;                    /* Number of bytes in term suffix */

  172320. 

  172321.   if( !pReader->aDoclist ){

  172322.     pNext = pReader->aNode;

  172323.   }else{

  172324.     pNext = &pReader->aDoclist[pReader->nDoclist];

  172325.   }

  172326. 

  172327.   if( !pNext || pNext>=&pReader->aNode[pReader->nNode] ){

  172328. 

  172329.     if( fts3SegReaderIsPending(pReader) ){

  172330.       Fts3HashElem *pElem = *(pReader->ppNextElem);

  172331.       sqlite3_free(pReader->aNode);

  172332.       pReader->aNode = 0;

  172333.       if( pElem ){

  172334.         char *aCopy;

  172335.         PendingList *pList = (PendingList *)fts3HashData(pElem);

  172336.         int nCopy = pList->nData+1;

  172337.         pReader->zTerm = (char *)fts3HashKey(pElem);

  172338.         pReader->nTerm = fts3HashKeysize(pElem);

  172339.         aCopy = (char*)sqlite3_malloc(nCopy);

  172340.         if( !aCopy ) return SQLITE_NOMEM;

  172341.         memcpy(aCopy, pList->aData, nCopy);

  172342.         pReader->nNode = pReader->nDoclist = nCopy;

  172343.         pReader->aNode = pReader->aDoclist = aCopy;

  172344.         pReader->ppNextElem++;

  172345.         assert( pReader->aNode );

  172346.       }

  172347.       return SQLITE_OK;

  172348.     }

  172349. 

  172350.     fts3SegReaderSetEof(pReader);

  172351. 

  172352.     /* If iCurrentBlock>=iLeafEndBlock, this is an EOF condition. All leaf 

  172353.     ** blocks have already been traversed.  */

  172354. #ifdef CORRUPT_DB

  172355.     assert( pReader->iCurrentBlock<=pReader->iLeafEndBlock || CORRUPT_DB );

  172356. #endif

  172357.     if( pReader->iCurrentBlock>=pReader->iLeafEndBlock ){

  172358.       return SQLITE_OK;

  172359.     }

  172360. 

  172361.     rc = sqlite3Fts3ReadBlock(

  172362.         p, ++pReader->iCurrentBlock, &pReader->aNode, &pReader->nNode, 

  172363.         (bIncr ? &pReader->nPopulate : 0)

  172364.     );

  172365.     if( rc!=SQLITE_OK ) return rc;

  172366.     assert( pReader->pBlob==0 );

  172367.     if( bIncr && pReader->nPopulate<pReader->nNode ){

  172368.       pReader->pBlob = p->pSegments;

  172369.       p->pSegments = 0;

  172370.     }

  172371.     pNext = pReader->aNode;

  172372.   }

  172373. 

  172374.   assert( !fts3SegReaderIsPending(pReader) );

  172375. 

  172376.   rc = fts3SegReaderRequire(pReader, pNext, FTS3_VARINT_MAX*2);

  172377.   if( rc!=SQLITE_OK ) return rc;

  172378.   

  172379.   /* Because of the FTS3_NODE_PADDING bytes of padding, the following is 

  172380.   ** safe (no risk of overread) even if the node data is corrupted. */

  172381.   pNext += fts3GetVarint32(pNext, &nPrefix);

  172382.   pNext += fts3GetVarint32(pNext, &nSuffix);

  172383.   if( nSuffix<=0 

  172384.    || (&pReader->aNode[pReader->nNode] - pNext)<nSuffix

  172385.    || nPrefix>pReader->nTermAlloc

  172386.   ){

  172387.     return FTS_CORRUPT_VTAB;

  172388.   }

  172389. 

  172390.   /* Both nPrefix and nSuffix were read by fts3GetVarint32() and so are

  172391.   ** between 0 and 0x7FFFFFFF. But the sum of the two may cause integer

  172392.   ** overflow - hence the (i64) casts.  */

  172393.   if( (i64)nPrefix+nSuffix>(i64)pReader->nTermAlloc ){

  172394.     i64 nNew = ((i64)nPrefix+nSuffix)*2;

  172395.     char *zNew = sqlite3_realloc64(pReader->zTerm, nNew);

  172396.     if( !zNew ){

  172397.       return SQLITE_NOMEM;

  172398.     }

  172399.     pReader->zTerm = zNew;

  172400.     pReader->nTermAlloc = nNew;

  172401.   }

  172402. 

  172403.   rc = fts3SegReaderRequire(pReader, pNext, nSuffix+FTS3_VARINT_MAX);

  172404.   if( rc!=SQLITE_OK ) return rc;

  172405. 

  172406.   memcpy(&pReader->zTerm[nPrefix], pNext, nSuffix);

  172407.   pReader->nTerm = nPrefix+nSuffix;

  172408.   pNext += nSuffix;

  172409.   pNext += fts3GetVarint32(pNext, &pReader->nDoclist);

  172410.   pReader->aDoclist = pNext;

  172411.   pReader->pOffsetList = 0;

  172412. 

  172413.   /* Check that the doclist does not appear to extend past the end of the

  172414.   ** b-tree node. And that the final byte of the doclist is 0x00. If either 

  172415.   ** of these statements is untrue, then the data structure is corrupt.

  172416.   */

  172417.   if( pReader->nDoclist > pReader->nNode-(pReader->aDoclist-pReader->aNode)

  172418.    || (pReader->nPopulate==0 && pReader->aDoclist[pReader->nDoclist-1])

  172419.   ){

  172420.     return FTS_CORRUPT_VTAB;

  172421.   }

  172422.   return SQLITE_OK;

  172423. }

  172424. 

  172425. /*

  172426. ** Set the SegReader to point to the first docid in the doclist associated

  172427. ** with the current term.

  172428. */

  172429. static int fts3SegReaderFirstDocid(Fts3Table *pTab, Fts3SegReader *pReader){

  172430.   int rc = SQLITE_OK;

  172431.   assert( pReader->aDoclist );

  172432.   assert( !pReader->pOffsetList );

  172433.   if( pTab->bDescIdx && fts3SegReaderIsPending(pReader) ){

  172434.     u8 bEof = 0;

  172435.     pReader->iDocid = 0;

  172436.     pReader->nOffsetList = 0;

  172437.     sqlite3Fts3DoclistPrev(0,

  172438.         pReader->aDoclist, pReader->nDoclist, &pReader->pOffsetList, 

  172439.         &pReader->iDocid, &pReader->nOffsetList, &bEof

  172440.     );

  172441.   }else{

  172442.     rc = fts3SegReaderRequire(pReader, pReader->aDoclist, FTS3_VARINT_MAX);

  172443.     if( rc==SQLITE_OK ){

  172444.       int n = sqlite3Fts3GetVarint(pReader->aDoclist, &pReader->iDocid);

  172445.       pReader->pOffsetList = &pReader->aDoclist[n];

  172446.     }

  172447.   }

  172448.   return rc;

  172449. }

  172450. 

  172451. /*

  172452. ** Advance the SegReader to point to the next docid in the doclist

  172453. ** associated with the current term.

  172454. ** 

  172455. ** If arguments ppOffsetList and pnOffsetList are not NULL, then 

  172456. ** *ppOffsetList is set to point to the first column-offset list

  172457. ** in the doclist entry (i.e. immediately past the docid varint).

  172458. ** *pnOffsetList is set to the length of the set of column-offset

  172459. ** lists, not including the nul-terminator byte. For example:

  172460. */

  172461. static int fts3SegReaderNextDocid(

  172462.   Fts3Table *pTab,

  172463.   Fts3SegReader *pReader,         /* Reader to advance to next docid */

  172464.   char **ppOffsetList,            /* OUT: Pointer to current position-list */

  172465.   int *pnOffsetList               /* OUT: Length of *ppOffsetList in bytes */

  172466. ){

  172467.   int rc = SQLITE_OK;

  172468.   char *p = pReader->pOffsetList;

  172469.   char c = 0;

  172470. 

  172471.   assert( p );

  172472. 

  172473.   if( pTab->bDescIdx && fts3SegReaderIsPending(pReader) ){

  172474.     /* A pending-terms seg-reader for an FTS4 table that uses order=desc.

  172475.     ** Pending-terms doclists are always built up in ascending order, so

  172476.     ** we have to iterate through them backwards here. */

  172477.     u8 bEof = 0;

  172478.     if( ppOffsetList ){

  172479.       *ppOffsetList = pReader->pOffsetList;

  172480.       *pnOffsetList = pReader->nOffsetList - 1;

  172481.     }

  172482.     sqlite3Fts3DoclistPrev(0,

  172483.         pReader->aDoclist, pReader->nDoclist, &p, &pReader->iDocid,

  172484.         &pReader->nOffsetList, &bEof

  172485.     );

  172486.     if( bEof ){

  172487.       pReader->pOffsetList = 0;

  172488.     }else{

  172489.       pReader->pOffsetList = p;

  172490.     }

  172491.   }else{

  172492.     char *pEnd = &pReader->aDoclist[pReader->nDoclist];

  172493. 

  172494.     /* Pointer p currently points at the first byte of an offset list. The

  172495.     ** following block advances it to point one byte past the end of

  172496.     ** the same offset list. */

  172497.     while( 1 ){

  172498.   

  172499.       /* The following line of code (and the "p++" below the while() loop) is

  172500.       ** normally all that is required to move pointer p to the desired 

  172501.       ** position. The exception is if this node is being loaded from disk

  172502.       ** incrementally and pointer "p" now points to the first byte past

  172503.       ** the populated part of pReader->aNode[].

  172504.       */

  172505.       while( *p | c ) c = *p++ & 0x80;

  172506.       assert( *p==0 );

  172507.   

  172508.       if( pReader->pBlob==0 || p<&pReader->aNode[pReader->nPopulate] ) break;

  172509.       rc = fts3SegReaderIncrRead(pReader);

  172510.       if( rc!=SQLITE_OK ) return rc;

  172511.     }

  172512.     p++;

  172513.   

  172514.     /* If required, populate the output variables with a pointer to and the

  172515.     ** size of the previous offset-list.

  172516.     */

  172517.     if( ppOffsetList ){

  172518.       *ppOffsetList = pReader->pOffsetList;

  172519.       *pnOffsetList = (int)(p - pReader->pOffsetList - 1);

  172520.     }

  172521. 

  172522.     /* List may have been edited in place by fts3EvalNearTrim() */

  172523.     while( p<pEnd && *p==0 ) p++;

  172524.   

  172525.     /* If there are no more entries in the doclist, set pOffsetList to

  172526.     ** NULL. Otherwise, set Fts3SegReader.iDocid to the next docid and

  172527.     ** Fts3SegReader.pOffsetList to point to the next offset list before

  172528.     ** returning.

  172529.     */

  172530.     if( p>=pEnd ){

  172531.       pReader->pOffsetList = 0;

  172532.     }else{

  172533.       rc = fts3SegReaderRequire(pReader, p, FTS3_VARINT_MAX);

  172534.       if( rc==SQLITE_OK ){

  172535.         sqlite3_int64 iDelta;

  172536.         pReader->pOffsetList = p + sqlite3Fts3GetVarint(p, &iDelta);

  172537.         if( pTab->bDescIdx ){

  172538.           pReader->iDocid -= iDelta;

  172539.         }else{

  172540.           pReader->iDocid += iDelta;

  172541.         }

  172542.       }

  172543.     }

  172544.   }

  172545. 

  172546.   return SQLITE_OK;

  172547. }

  172548. 

  172549. 

  172550. SQLITE_PRIVATE int sqlite3Fts3MsrOvfl(

  172551.   Fts3Cursor *pCsr, 

  172552.   Fts3MultiSegReader *pMsr,

  172553.   int *pnOvfl

  172554. ){

  172555.   Fts3Table *p = (Fts3Table*)pCsr->base.pVtab;

  172556.   int nOvfl = 0;

  172557.   int ii;

  172558.   int rc = SQLITE_OK;

  172559.   int pgsz = p->nPgsz;

  172560. 

  172561.   assert( p->bFts4 );

  172562.   assert( pgsz>0 );

  172563. 

  172564.   for(ii=0; rc==SQLITE_OK && ii<pMsr->nSegment; ii++){

  172565.     Fts3SegReader *pReader = pMsr->apSegment[ii];

  172566.     if( !fts3SegReaderIsPending(pReader) 

  172567.      && !fts3SegReaderIsRootOnly(pReader) 

  172568.     ){

  172569.       sqlite3_int64 jj;

  172570.       for(jj=pReader->iStartBlock; jj<=pReader->iLeafEndBlock; jj++){

  172571.         int nBlob;

  172572.         rc = sqlite3Fts3ReadBlock(p, jj, 0, &nBlob, 0);

  172573.         if( rc!=SQLITE_OK ) break;

  172574.         if( (nBlob+35)>pgsz ){

  172575.           nOvfl += (nBlob + 34)/pgsz;

  172576.         }

  172577.       }

  172578.     }

  172579.   }

  172580.   *pnOvfl = nOvfl;

  172581.   return rc;

  172582. }

  172583. 

  172584. /*

  172585. ** Free all allocations associated with the iterator passed as the 

  172586. ** second argument.

  172587. */

  172588. SQLITE_PRIVATE void sqlite3Fts3SegReaderFree(Fts3SegReader *pReader){

  172589.   if( pReader ){

  172590.     if( !fts3SegReaderIsPending(pReader) ){

  172591.       sqlite3_free(pReader->zTerm);

  172592.     }

  172593.     if( !fts3SegReaderIsRootOnly(pReader) ){

  172594.       sqlite3_free(pReader->aNode);

  172595.     }

  172596.     sqlite3_blob_close(pReader->pBlob);

  172597.   }

  172598.   sqlite3_free(pReader);

  172599. }

  172600. 

  172601. /*

  172602. ** Allocate a new SegReader object.

  172603. */

  172604. SQLITE_PRIVATE int sqlite3Fts3SegReaderNew(

  172605.   int iAge,                       /* Segment "age". */

  172606.   int bLookup,                    /* True for a lookup only */

  172607.   sqlite3_int64 iStartLeaf,       /* First leaf to traverse */

  172608.   sqlite3_int64 iEndLeaf,         /* Final leaf to traverse */

  172609.   sqlite3_int64 iEndBlock,        /* Final block of segment */

  172610.   const char *zRoot,              /* Buffer containing root node */

  172611.   int nRoot,                      /* Size of buffer containing root node */

  172612.   Fts3SegReader **ppReader        /* OUT: Allocated Fts3SegReader */

  172613. ){

  172614.   Fts3SegReader *pReader;         /* Newly allocated SegReader object */

  172615.   int nExtra = 0;                 /* Bytes to allocate segment root node */

  172616. 

  172617.   assert( zRoot!=0 || nRoot==0 );

  172618. #ifdef CORRUPT_DB

  172619.   assert( zRoot!=0 || CORRUPT_DB );

  172620. #endif

  172621. 

  172622.   if( iStartLeaf==0 ){

  172623.     if( iEndLeaf!=0 ) return FTS_CORRUPT_VTAB;

  172624.     nExtra = nRoot + FTS3_NODE_PADDING;

  172625.   }

  172626. 

  172627.   pReader = (Fts3SegReader *)sqlite3_malloc(sizeof(Fts3SegReader) + nExtra);

  172628.   if( !pReader ){

  172629.     return SQLITE_NOMEM;

  172630.   }

  172631.   memset(pReader, 0, sizeof(Fts3SegReader));

  172632.   pReader->iIdx = iAge;

  172633.   pReader->bLookup = bLookup!=0;

  172634.   pReader->iStartBlock = iStartLeaf;

  172635.   pReader->iLeafEndBlock = iEndLeaf;

  172636.   pReader->iEndBlock = iEndBlock;

  172637. 

  172638.   if( nExtra ){

  172639.     /* The entire segment is stored in the root node. */

  172640.     pReader->aNode = (char *)&pReader[1];

  172641.     pReader->rootOnly = 1;

  172642.     pReader->nNode = nRoot;

  172643.     if( nRoot ) memcpy(pReader->aNode, zRoot, nRoot);

  172644.     memset(&pReader->aNode[nRoot], 0, FTS3_NODE_PADDING);

  172645.   }else{

  172646.     pReader->iCurrentBlock = iStartLeaf-1;

  172647.   }

  172648.   *ppReader = pReader;

  172649.   return SQLITE_OK;

  172650. }

  172651. 

  172652. /*

  172653. ** This is a comparison function used as a qsort() callback when sorting

  172654. ** an array of pending terms by term. This occurs as part of flushing

  172655. ** the contents of the pending-terms hash table to the database.

  172656. */

  172657. static int SQLITE_CDECL fts3CompareElemByTerm(

  172658.   const void *lhs,

  172659.   const void *rhs

  172660. ){

  172661.   char *z1 = fts3HashKey(*(Fts3HashElem **)lhs);

  172662.   char *z2 = fts3HashKey(*(Fts3HashElem **)rhs);

  172663.   int n1 = fts3HashKeysize(*(Fts3HashElem **)lhs);

  172664.   int n2 = fts3HashKeysize(*(Fts3HashElem **)rhs);

  172665. 

  172666.   int n = (n1<n2 ? n1 : n2);

  172667.   int c = memcmp(z1, z2, n);

  172668.   if( c==0 ){

  172669.     c = n1 - n2;

  172670.   }

  172671.   return c;

  172672. }

  172673. 

  172674. /*

  172675. ** This function is used to allocate an Fts3SegReader that iterates through

  172676. ** a subset of the terms stored in the Fts3Table.pendingTerms array.

  172677. **

  172678. ** If the isPrefixIter parameter is zero, then the returned SegReader iterates

  172679. ** through each term in the pending-terms table. Or, if isPrefixIter is

  172680. ** non-zero, it iterates through each term and its prefixes. For example, if

  172681. ** the pending terms hash table contains the terms "sqlite", "mysql" and

  172682. ** "firebird", then the iterator visits the following 'terms' (in the order

  172683. ** shown):

  172684. **

  172685. **   f fi fir fire fireb firebi firebir firebird

  172686. **   m my mys mysq mysql

  172687. **   s sq sql sqli sqlit sqlite

  172688. **

  172689. ** Whereas if isPrefixIter is zero, the terms visited are:

  172690. **

  172691. **   firebird mysql sqlite

  172692. */

  172693. SQLITE_PRIVATE int sqlite3Fts3SegReaderPending(

  172694.   Fts3Table *p,                   /* Virtual table handle */

  172695.   int iIndex,                     /* Index for p->aIndex */

  172696.   const char *zTerm,              /* Term to search for */

  172697.   int nTerm,                      /* Size of buffer zTerm */

  172698.   int bPrefix,                    /* True for a prefix iterator */

  172699.   Fts3SegReader **ppReader        /* OUT: SegReader for pending-terms */

  172700. ){

  172701.   Fts3SegReader *pReader = 0;     /* Fts3SegReader object to return */

  172702.   Fts3HashElem *pE;               /* Iterator variable */

  172703.   Fts3HashElem **aElem = 0;       /* Array of term hash entries to scan */

  172704.   int nElem = 0;                  /* Size of array at aElem */

  172705.   int rc = SQLITE_OK;             /* Return Code */

  172706.   Fts3Hash *pHash;

  172707. 

  172708.   pHash = &p->aIndex[iIndex].hPending;

  172709.   if( bPrefix ){

  172710.     int nAlloc = 0;               /* Size of allocated array at aElem */

  172711. 

  172712.     for(pE=fts3HashFirst(pHash); pE; pE=fts3HashNext(pE)){

  172713.       char *zKey = (char *)fts3HashKey(pE);

  172714.       int nKey = fts3HashKeysize(pE);

  172715.       if( nTerm==0 || (nKey>=nTerm && 0==memcmp(zKey, zTerm, nTerm)) ){

  172716.         if( nElem==nAlloc ){

  172717.           Fts3HashElem **aElem2;

  172718.           nAlloc += 16;

  172719.           aElem2 = (Fts3HashElem **)sqlite3_realloc(

  172720.               aElem, nAlloc*sizeof(Fts3HashElem *)

  172721.           );

  172722.           if( !aElem2 ){

  172723.             rc = SQLITE_NOMEM;

  172724.             nElem = 0;

  172725.             break;

  172726.           }

  172727.           aElem = aElem2;

  172728.         }

  172729. 

  172730.         aElem[nElem++] = pE;

  172731.       }

  172732.     }

  172733. 

  172734.     /* If more than one term matches the prefix, sort the Fts3HashElem

  172735.     ** objects in term order using qsort(). This uses the same comparison

  172736.     ** callback as is used when flushing terms to disk.

  172737.     */

  172738.     if( nElem>1 ){

  172739.       qsort(aElem, nElem, sizeof(Fts3HashElem *), fts3CompareElemByTerm);

  172740.     }

  172741. 

  172742.   }else{

  172743.     /* The query is a simple term lookup that matches at most one term in

  172744.     ** the index. All that is required is a straight hash-lookup. 

  172745.     **

  172746.     ** Because the stack address of pE may be accessed via the aElem pointer

  172747.     ** below, the "Fts3HashElem *pE" must be declared so that it is valid

  172748.     ** within this entire function, not just this "else{...}" block.

  172749.     */

  172750.     pE = fts3HashFindElem(pHash, zTerm, nTerm);

  172751.     if( pE ){

  172752.       aElem = &pE;

  172753.       nElem = 1;

  172754.     }

  172755.   }

  172756. 

  172757.   if( nElem>0 ){

  172758.     sqlite3_int64 nByte;

  172759.     nByte = sizeof(Fts3SegReader) + (nElem+1)*sizeof(Fts3HashElem *);

  172760.     pReader = (Fts3SegReader *)sqlite3_malloc64(nByte);

  172761.     if( !pReader ){

  172762.       rc = SQLITE_NOMEM;

  172763.     }else{

  172764.       memset(pReader, 0, nByte);

  172765.       pReader->iIdx = 0x7FFFFFFF;

  172766.       pReader->ppNextElem = (Fts3HashElem **)&pReader[1];

  172767.       memcpy(pReader->ppNextElem, aElem, nElem*sizeof(Fts3HashElem *));

  172768.     }

  172769.   }

  172770. 

  172771.   if( bPrefix ){

  172772.     sqlite3_free(aElem);

  172773.   }

  172774.   *ppReader = pReader;

  172775.   return rc;

  172776. }

  172777. 

  172778. /*

  172779. ** Compare the entries pointed to by two Fts3SegReader structures. 

  172780. ** Comparison is as follows:

  172781. **

  172782. **   1) EOF is greater than not EOF.

  172783. **

  172784. **   2) The current terms (if any) are compared using memcmp(). If one

  172785. **      term is a prefix of another, the longer term is considered the

  172786. **      larger.

  172787. **

  172788. **   3) By segment age. An older segment is considered larger.

  172789. */

  172790. static int fts3SegReaderCmp(Fts3SegReader *pLhs, Fts3SegReader *pRhs){

  172791.   int rc;

  172792.   if( pLhs->aNode && pRhs->aNode ){

  172793.     int rc2 = pLhs->nTerm - pRhs->nTerm;

  172794.     if( rc2<0 ){

  172795.       rc = memcmp(pLhs->zTerm, pRhs->zTerm, pLhs->nTerm);

  172796.     }else{

  172797.       rc = memcmp(pLhs->zTerm, pRhs->zTerm, pRhs->nTerm);

  172798.     }

  172799.     if( rc==0 ){

  172800.       rc = rc2;

  172801.     }

  172802.   }else{

  172803.     rc = (pLhs->aNode==0) - (pRhs->aNode==0);

  172804.   }

  172805.   if( rc==0 ){

  172806.     rc = pRhs->iIdx - pLhs->iIdx;

  172807.   }

  172808.   assert( rc!=0 );

  172809.   return rc;

  172810. }

  172811. 

  172812. /*

  172813. ** A different comparison function for SegReader structures. In this

  172814. ** version, it is assumed that each SegReader points to an entry in

  172815. ** a doclist for identical terms. Comparison is made as follows:

  172816. **

  172817. **   1) EOF (end of doclist in this case) is greater than not EOF.

  172818. **

  172819. **   2) By current docid.

  172820. **

  172821. **   3) By segment age. An older segment is considered larger.

  172822. */

  172823. static int fts3SegReaderDoclistCmp(Fts3SegReader *pLhs, Fts3SegReader *pRhs){

  172824.   int rc = (pLhs->pOffsetList==0)-(pRhs->pOffsetList==0);

  172825.   if( rc==0 ){

  172826.     if( pLhs->iDocid==pRhs->iDocid ){

  172827.       rc = pRhs->iIdx - pLhs->iIdx;

  172828.     }else{

  172829.       rc = (pLhs->iDocid > pRhs->iDocid) ? 1 : -1;

  172830.     }

  172831.   }

  172832.   assert( pLhs->aNode && pRhs->aNode );

  172833.   return rc;

  172834. }

  172835. static int fts3SegReaderDoclistCmpRev(Fts3SegReader *pLhs, Fts3SegReader *pRhs){

  172836.   int rc = (pLhs->pOffsetList==0)-(pRhs->pOffsetList==0);

  172837.   if( rc==0 ){

  172838.     if( pLhs->iDocid==pRhs->iDocid ){

  172839.       rc = pRhs->iIdx - pLhs->iIdx;

  172840.     }else{

  172841.       rc = (pLhs->iDocid < pRhs->iDocid) ? 1 : -1;

  172842.     }

  172843.   }

  172844.   assert( pLhs->aNode && pRhs->aNode );

  172845.   return rc;

  172846. }

  172847. 

  172848. /*

  172849. ** Compare the term that the Fts3SegReader object passed as the first argument

  172850. ** points to with the term specified by arguments zTerm and nTerm. 

  172851. **

  172852. ** If the pSeg iterator is already at EOF, return 0. Otherwise, return

  172853. ** -ve if the pSeg term is less than zTerm/nTerm, 0 if the two terms are

  172854. ** equal, or +ve if the pSeg term is greater than zTerm/nTerm.

  172855. */

  172856. static int fts3SegReaderTermCmp(

  172857.   Fts3SegReader *pSeg,            /* Segment reader object */

  172858.   const char *zTerm,              /* Term to compare to */

  172859.   int nTerm                       /* Size of term zTerm in bytes */

  172860. ){

  172861.   int res = 0;

  172862.   if( pSeg->aNode ){

  172863.     if( pSeg->nTerm>nTerm ){

  172864.       res = memcmp(pSeg->zTerm, zTerm, nTerm);

  172865.     }else{

  172866.       res = memcmp(pSeg->zTerm, zTerm, pSeg->nTerm);

  172867.     }

  172868.     if( res==0 ){

  172869.       res = pSeg->nTerm-nTerm;

  172870.     }

  172871.   }

  172872.   return res;

  172873. }

  172874. 

  172875. /*

  172876. ** Argument apSegment is an array of nSegment elements. It is known that

  172877. ** the final (nSegment-nSuspect) members are already in sorted order

  172878. ** (according to the comparison function provided). This function shuffles

  172879. ** the array around until all entries are in sorted order.

  172880. */

  172881. static void fts3SegReaderSort(

  172882.   Fts3SegReader **apSegment,                     /* Array to sort entries of */

  172883.   int nSegment,                                  /* Size of apSegment array */

  172884.   int nSuspect,                                  /* Unsorted entry count */

  172885.   int (*xCmp)(Fts3SegReader *, Fts3SegReader *)  /* Comparison function */

  172886. ){

  172887.   int i;                          /* Iterator variable */

  172888. 

  172889.   assert( nSuspect<=nSegment );

  172890. 

  172891.   if( nSuspect==nSegment ) nSuspect--;

  172892.   for(i=nSuspect-1; i>=0; i--){

  172893.     int j;

  172894.     for(j=i; j<(nSegment-1); j++){

  172895.       Fts3SegReader *pTmp;

  172896.       if( xCmp(apSegment[j], apSegment[j+1])<0 ) break;

  172897.       pTmp = apSegment[j+1];

  172898.       apSegment[j+1] = apSegment[j];

  172899.       apSegment[j] = pTmp;

  172900.     }

  172901.   }

  172902. 

  172903. #ifndef NDEBUG

  172904.   /* Check that the list really is sorted now. */

  172905.   for(i=0; i<(nSuspect-1); i++){

  172906.     assert( xCmp(apSegment[i], apSegment[i+1])<0 );

  172907.   }

  172908. #endif

  172909. }

  172910. 

  172911. /* 

  172912. ** Insert a record into the %_segments table.

  172913. */

  172914. static int fts3WriteSegment(

  172915.   Fts3Table *p,                   /* Virtual table handle */

  172916.   sqlite3_int64 iBlock,           /* Block id for new block */

  172917.   char *z,                        /* Pointer to buffer containing block data */

  172918.   int n                           /* Size of buffer z in bytes */

  172919. ){

  172920.   sqlite3_stmt *pStmt;

  172921.   int rc = fts3SqlStmt(p, SQL_INSERT_SEGMENTS, &pStmt, 0);

  172922.   if( rc==SQLITE_OK ){

  172923.     sqlite3_bind_int64(pStmt, 1, iBlock);

  172924.     sqlite3_bind_blob(pStmt, 2, z, n, SQLITE_STATIC);

  172925.     sqlite3_step(pStmt);

  172926.     rc = sqlite3_reset(pStmt);

  172927.     sqlite3_bind_null(pStmt, 2);

  172928.   }

  172929.   return rc;

  172930. }

  172931. 

  172932. /*

  172933. ** Find the largest relative level number in the table. If successful, set

  172934. ** *pnMax to this value and return SQLITE_OK. Otherwise, if an error occurs,

  172935. ** set *pnMax to zero and return an SQLite error code.

  172936. */

  172937. SQLITE_PRIVATE int sqlite3Fts3MaxLevel(Fts3Table *p, int *pnMax){

  172938.   int rc;

  172939.   int mxLevel = 0;

  172940.   sqlite3_stmt *pStmt = 0;

  172941. 

  172942.   rc = fts3SqlStmt(p, SQL_SELECT_MXLEVEL, &pStmt, 0);

  172943.   if( rc==SQLITE_OK ){

  172944.     if( SQLITE_ROW==sqlite3_step(pStmt) ){

  172945.       mxLevel = sqlite3_column_int(pStmt, 0);

  172946.     }

  172947.     rc = sqlite3_reset(pStmt);

  172948.   }

  172949.   *pnMax = mxLevel;

  172950.   return rc;

  172951. }

  172952. 

  172953. /* 

  172954. ** Insert a record into the %_segdir table.

  172955. */

  172956. static int fts3WriteSegdir(

  172957.   Fts3Table *p,                   /* Virtual table handle */

  172958.   sqlite3_int64 iLevel,           /* Value for "level" field (absolute level) */

  172959.   int iIdx,                       /* Value for "idx" field */

  172960.   sqlite3_int64 iStartBlock,      /* Value for "start_block" field */

  172961.   sqlite3_int64 iLeafEndBlock,    /* Value for "leaves_end_block" field */

  172962.   sqlite3_int64 iEndBlock,        /* Value for "end_block" field */

  172963.   sqlite3_int64 nLeafData,        /* Bytes of leaf data in segment */

  172964.   char *zRoot,                    /* Blob value for "root" field */

  172965.   int nRoot                       /* Number of bytes in buffer zRoot */

  172966. ){

  172967.   sqlite3_stmt *pStmt;

  172968.   int rc = fts3SqlStmt(p, SQL_INSERT_SEGDIR, &pStmt, 0);

  172969.   if( rc==SQLITE_OK ){

  172970.     sqlite3_bind_int64(pStmt, 1, iLevel);

  172971.     sqlite3_bind_int(pStmt, 2, iIdx);

  172972.     sqlite3_bind_int64(pStmt, 3, iStartBlock);

  172973.     sqlite3_bind_int64(pStmt, 4, iLeafEndBlock);

  172974.     if( nLeafData==0 ){

  172975.       sqlite3_bind_int64(pStmt, 5, iEndBlock);

  172976.     }else{

  172977.       char *zEnd = sqlite3_mprintf("%lld %lld", iEndBlock, nLeafData);

  172978.       if( !zEnd ) return SQLITE_NOMEM;

  172979.       sqlite3_bind_text(pStmt, 5, zEnd, -1, sqlite3_free);

  172980.     }

  172981.     sqlite3_bind_blob(pStmt, 6, zRoot, nRoot, SQLITE_STATIC);

  172982.     sqlite3_step(pStmt);

  172983.     rc = sqlite3_reset(pStmt);

  172984.     sqlite3_bind_null(pStmt, 6);

  172985.   }

  172986.   return rc;

  172987. }

  172988. 

  172989. /*

  172990. ** Return the size of the common prefix (if any) shared by zPrev and

  172991. ** zNext, in bytes. For example, 

  172992. **

  172993. **   fts3PrefixCompress("abc", 3, "abcdef", 6)   // returns 3

  172994. **   fts3PrefixCompress("abX", 3, "abcdef", 6)   // returns 2

  172995. **   fts3PrefixCompress("abX", 3, "Xbcdef", 6)   // returns 0

  172996. */

  172997. static int fts3PrefixCompress(

  172998.   const char *zPrev,              /* Buffer containing previous term */

  172999.   int nPrev,                      /* Size of buffer zPrev in bytes */

  173000.   const char *zNext,              /* Buffer containing next term */

  173001.   int nNext                       /* Size of buffer zNext in bytes */

  173002. ){

  173003.   int n;

  173004.   UNUSED_PARAMETER(nNext);

  173005.   for(n=0; n<nPrev && zPrev[n]==zNext[n]; n++);

  173006.   return n;

  173007. }

  173008. 

  173009. /*

  173010. ** Add term zTerm to the SegmentNode. It is guaranteed that zTerm is larger

  173011. ** (according to memcmp) than the previous term.

  173012. */

  173013. static int fts3NodeAddTerm(

  173014.   Fts3Table *p,                   /* Virtual table handle */

  173015.   SegmentNode **ppTree,           /* IN/OUT: SegmentNode handle */ 

  173016.   int isCopyTerm,                 /* True if zTerm/nTerm is transient */

  173017.   const char *zTerm,              /* Pointer to buffer containing term */

  173018.   int nTerm                       /* Size of term in bytes */

  173019. ){

  173020.   SegmentNode *pTree = *ppTree;

  173021.   int rc;

  173022.   SegmentNode *pNew;

  173023. 

  173024.   /* First try to append the term to the current node. Return early if 

  173025.   ** this is possible.

  173026.   */

  173027.   if( pTree ){

  173028.     int nData = pTree->nData;     /* Current size of node in bytes */

  173029.     int nReq = nData;             /* Required space after adding zTerm */

  173030.     int nPrefix;                  /* Number of bytes of prefix compression */

  173031.     int nSuffix;                  /* Suffix length */

  173032. 

  173033.     nPrefix = fts3PrefixCompress(pTree->zTerm, pTree->nTerm, zTerm, nTerm);

  173034.     nSuffix = nTerm-nPrefix;

  173035. 

  173036.     nReq += sqlite3Fts3VarintLen(nPrefix)+sqlite3Fts3VarintLen(nSuffix)+nSuffix;

  173037.     if( nReq<=p->nNodeSize || !pTree->zTerm ){

  173038. 

  173039.       if( nReq>p->nNodeSize ){

  173040.         /* An unusual case: this is the first term to be added to the node

  173041.         ** and the static node buffer (p->nNodeSize bytes) is not large

  173042.         ** enough. Use a separately malloced buffer instead This wastes

  173043.         ** p->nNodeSize bytes, but since this scenario only comes about when

  173044.         ** the database contain two terms that share a prefix of almost 2KB, 

  173045.         ** this is not expected to be a serious problem. 

  173046.         */

  173047.         assert( pTree->aData==(char *)&pTree[1] );

  173048.         pTree->aData = (char *)sqlite3_malloc(nReq);

  173049.         if( !pTree->aData ){

  173050.           return SQLITE_NOMEM;

  173051.         }

  173052.       }

  173053. 

  173054.       if( pTree->zTerm ){

  173055.         /* There is no prefix-length field for first term in a node */

  173056.         nData += sqlite3Fts3PutVarint(&pTree->aData[nData], nPrefix);

  173057.       }

  173058. 

  173059.       nData += sqlite3Fts3PutVarint(&pTree->aData[nData], nSuffix);

  173060.       memcpy(&pTree->aData[nData], &zTerm[nPrefix], nSuffix);

  173061.       pTree->nData = nData + nSuffix;

  173062.       pTree->nEntry++;

  173063. 

  173064.       if( isCopyTerm ){

  173065.         if( pTree->nMalloc<nTerm ){

  173066.           char *zNew = sqlite3_realloc(pTree->zMalloc, nTerm*2);

  173067.           if( !zNew ){

  173068.             return SQLITE_NOMEM;

  173069.           }

  173070.           pTree->nMalloc = nTerm*2;

  173071.           pTree->zMalloc = zNew;

  173072.         }

  173073.         pTree->zTerm = pTree->zMalloc;

  173074.         memcpy(pTree->zTerm, zTerm, nTerm);

  173075.         pTree->nTerm = nTerm;

  173076.       }else{

  173077.         pTree->zTerm = (char *)zTerm;

  173078.         pTree->nTerm = nTerm;

  173079.       }

  173080.       return SQLITE_OK;

  173081.     }

  173082.   }

  173083. 

  173084.   /* If control flows to here, it was not possible to append zTerm to the

  173085.   ** current node. Create a new node (a right-sibling of the current node).

  173086.   ** If this is the first node in the tree, the term is added to it.

  173087.   **

  173088.   ** Otherwise, the term is not added to the new node, it is left empty for

  173089.   ** now. Instead, the term is inserted into the parent of pTree. If pTree 

  173090.   ** has no parent, one is created here.

  173091.   */

  173092.   pNew = (SegmentNode *)sqlite3_malloc(sizeof(SegmentNode) + p->nNodeSize);

  173093.   if( !pNew ){

  173094.     return SQLITE_NOMEM;

  173095.   }

  173096.   memset(pNew, 0, sizeof(SegmentNode));

  173097.   pNew->nData = 1 + FTS3_VARINT_MAX;

  173098.   pNew->aData = (char *)&pNew[1];

  173099. 

  173100.   if( pTree ){

  173101.     SegmentNode *pParent = pTree->pParent;

  173102.     rc = fts3NodeAddTerm(p, &pParent, isCopyTerm, zTerm, nTerm);

  173103.     if( pTree->pParent==0 ){

  173104.       pTree->pParent = pParent;

  173105.     }

  173106.     pTree->pRight = pNew;

  173107.     pNew->pLeftmost = pTree->pLeftmost;

  173108.     pNew->pParent = pParent;

  173109.     pNew->zMalloc = pTree->zMalloc;

  173110.     pNew->nMalloc = pTree->nMalloc;

  173111.     pTree->zMalloc = 0;

  173112.   }else{

  173113.     pNew->pLeftmost = pNew;

  173114.     rc = fts3NodeAddTerm(p, &pNew, isCopyTerm, zTerm, nTerm); 

  173115.   }

  173116. 

  173117.   *ppTree = pNew;

  173118.   return rc;

  173119. }

  173120. 

  173121. /*

  173122. ** Helper function for fts3NodeWrite().

  173123. */

  173124. static int fts3TreeFinishNode(

  173125.   SegmentNode *pTree, 

  173126.   int iHeight, 

  173127.   sqlite3_int64 iLeftChild

  173128. ){

  173129.   int nStart;

  173130.   assert( iHeight>=1 && iHeight<128 );

  173131.   nStart = FTS3_VARINT_MAX - sqlite3Fts3VarintLen(iLeftChild);

  173132.   pTree->aData[nStart] = (char)iHeight;

  173133.   sqlite3Fts3PutVarint(&pTree->aData[nStart+1], iLeftChild);

  173134.   return nStart;

  173135. }

  173136. 

  173137. /*

  173138. ** Write the buffer for the segment node pTree and all of its peers to the

  173139. ** database. Then call this function recursively to write the parent of 

  173140. ** pTree and its peers to the database. 

  173141. **

  173142. ** Except, if pTree is a root node, do not write it to the database. Instead,

  173143. ** set output variables *paRoot and *pnRoot to contain the root node.

  173144. **

  173145. ** If successful, SQLITE_OK is returned and output variable *piLast is

  173146. ** set to the largest blockid written to the database (or zero if no

  173147. ** blocks were written to the db). Otherwise, an SQLite error code is 

  173148. ** returned.

  173149. */

  173150. static int fts3NodeWrite(

  173151.   Fts3Table *p,                   /* Virtual table handle */

  173152.   SegmentNode *pTree,             /* SegmentNode handle */

  173153.   int iHeight,                    /* Height of this node in tree */

  173154.   sqlite3_int64 iLeaf,            /* Block id of first leaf node */

  173155.   sqlite3_int64 iFree,            /* Block id of next free slot in %_segments */

  173156.   sqlite3_int64 *piLast,          /* OUT: Block id of last entry written */

  173157.   char **paRoot,                  /* OUT: Data for root node */

  173158.   int *pnRoot                     /* OUT: Size of root node in bytes */

  173159. ){

  173160.   int rc = SQLITE_OK;

  173161. 

  173162.   if( !pTree->pParent ){

  173163.     /* Root node of the tree. */

  173164.     int nStart = fts3TreeFinishNode(pTree, iHeight, iLeaf);

  173165.     *piLast = iFree-1;

  173166.     *pnRoot = pTree->nData - nStart;

  173167.     *paRoot = &pTree->aData[nStart];

  173168.   }else{

  173169.     SegmentNode *pIter;

  173170.     sqlite3_int64 iNextFree = iFree;

  173171.     sqlite3_int64 iNextLeaf = iLeaf;

  173172.     for(pIter=pTree->pLeftmost; pIter && rc==SQLITE_OK; pIter=pIter->pRight){

  173173.       int nStart = fts3TreeFinishNode(pIter, iHeight, iNextLeaf);

  173174.       int nWrite = pIter->nData - nStart;

  173175.   

  173176.       rc = fts3WriteSegment(p, iNextFree, &pIter->aData[nStart], nWrite);

  173177.       iNextFree++;

  173178.       iNextLeaf += (pIter->nEntry+1);

  173179.     }

  173180.     if( rc==SQLITE_OK ){

  173181.       assert( iNextLeaf==iFree );

  173182.       rc = fts3NodeWrite(

  173183.           p, pTree->pParent, iHeight+1, iFree, iNextFree, piLast, paRoot, pnRoot

  173184.       );

  173185.     }

  173186.   }

  173187. 

  173188.   return rc;

  173189. }

  173190. 

  173191. /*

  173192. ** Free all memory allocations associated with the tree pTree.

  173193. */

  173194. static void fts3NodeFree(SegmentNode *pTree){

  173195.   if( pTree ){

  173196.     SegmentNode *p = pTree->pLeftmost;

  173197.     fts3NodeFree(p->pParent);

  173198.     while( p ){

  173199.       SegmentNode *pRight = p->pRight;

  173200.       if( p->aData!=(char *)&p[1] ){

  173201.         sqlite3_free(p->aData);

  173202.       }

  173203.       assert( pRight==0 || p->zMalloc==0 );

  173204.       sqlite3_free(p->zMalloc);

  173205.       sqlite3_free(p);

  173206.       p = pRight;

  173207.     }

  173208.   }

  173209. }

  173210. 

  173211. /*

  173212. ** Add a term to the segment being constructed by the SegmentWriter object

  173213. ** *ppWriter. When adding the first term to a segment, *ppWriter should

  173214. ** be passed NULL. This function will allocate a new SegmentWriter object

  173215. ** and return it via the input/output variable *ppWriter in this case.

  173216. **

  173217. ** If successful, SQLITE_OK is returned. Otherwise, an SQLite error code.

  173218. */

  173219. static int fts3SegWriterAdd(

  173220.   Fts3Table *p,                   /* Virtual table handle */

  173221.   SegmentWriter **ppWriter,       /* IN/OUT: SegmentWriter handle */ 

  173222.   int isCopyTerm,                 /* True if buffer zTerm must be copied */

  173223.   const char *zTerm,              /* Pointer to buffer containing term */

  173224.   int nTerm,                      /* Size of term in bytes */

  173225.   const char *aDoclist,           /* Pointer to buffer containing doclist */

  173226.   int nDoclist                    /* Size of doclist in bytes */

  173227. ){

  173228.   int nPrefix;                    /* Size of term prefix in bytes */

  173229.   int nSuffix;                    /* Size of term suffix in bytes */

  173230.   int nReq;                       /* Number of bytes required on leaf page */

  173231.   int nData;

  173232.   SegmentWriter *pWriter = *ppWriter;

  173233. 

  173234.   if( !pWriter ){

  173235.     int rc;

  173236.     sqlite3_stmt *pStmt;

  173237. 

  173238.     /* Allocate the SegmentWriter structure */

  173239.     pWriter = (SegmentWriter *)sqlite3_malloc(sizeof(SegmentWriter));

  173240.     if( !pWriter ) return SQLITE_NOMEM;

  173241.     memset(pWriter, 0, sizeof(SegmentWriter));

  173242.     *ppWriter = pWriter;

  173243. 

  173244.     /* Allocate a buffer in which to accumulate data */

  173245.     pWriter->aData = (char *)sqlite3_malloc(p->nNodeSize);

  173246.     if( !pWriter->aData ) return SQLITE_NOMEM;

  173247.     pWriter->nSize = p->nNodeSize;

  173248. 

  173249.     /* Find the next free blockid in the %_segments table */

  173250.     rc = fts3SqlStmt(p, SQL_NEXT_SEGMENTS_ID, &pStmt, 0);

  173251.     if( rc!=SQLITE_OK ) return rc;

  173252.     if( SQLITE_ROW==sqlite3_step(pStmt) ){

  173253.       pWriter->iFree = sqlite3_column_int64(pStmt, 0);

  173254.       pWriter->iFirst = pWriter->iFree;

  173255.     }

  173256.     rc = sqlite3_reset(pStmt);

  173257.     if( rc!=SQLITE_OK ) return rc;

  173258.   }

  173259.   nData = pWriter->nData;

  173260. 

  173261.   nPrefix = fts3PrefixCompress(pWriter->zTerm, pWriter->nTerm, zTerm, nTerm);

  173262.   nSuffix = nTerm-nPrefix;

  173263. 

  173264.   /* If nSuffix is zero or less, then zTerm/nTerm must be a prefix of 

  173265.   ** pWriter->zTerm/pWriter->nTerm. i.e. must be equal to or less than when

  173266.   ** compared with BINARY collation. This indicates corruption.  */

  173267.   if( nSuffix<=0 ) return FTS_CORRUPT_VTAB;

  173268. 

  173269.   /* Figure out how many bytes are required by this new entry */

  173270.   nReq = sqlite3Fts3VarintLen(nPrefix) +    /* varint containing prefix size */

  173271.     sqlite3Fts3VarintLen(nSuffix) +         /* varint containing suffix size */

  173272.     nSuffix +                               /* Term suffix */

  173273.     sqlite3Fts3VarintLen(nDoclist) +        /* Size of doclist */

  173274.     nDoclist;                               /* Doclist data */

  173275. 

  173276.   if( nData>0 && nData+nReq>p->nNodeSize ){

  173277.     int rc;

  173278. 

  173279.     /* The current leaf node is full. Write it out to the database. */

  173280.     rc = fts3WriteSegment(p, pWriter->iFree++, pWriter->aData, nData);

  173281.     if( rc!=SQLITE_OK ) return rc;

  173282.     p->nLeafAdd++;

  173283. 

  173284.     /* Add the current term to the interior node tree. The term added to

  173285.     ** the interior tree must:

  173286.     **

  173287.     **   a) be greater than the largest term on the leaf node just written

  173288.     **      to the database (still available in pWriter->zTerm), and

  173289.     **

  173290.     **   b) be less than or equal to the term about to be added to the new

  173291.     **      leaf node (zTerm/nTerm).

  173292.     **

  173293.     ** In other words, it must be the prefix of zTerm 1 byte longer than

  173294.     ** the common prefix (if any) of zTerm and pWriter->zTerm.

  173295.     */

  173296.     assert( nPrefix<nTerm );

  173297.     rc = fts3NodeAddTerm(p, &pWriter->pTree, isCopyTerm, zTerm, nPrefix+1);

  173298.     if( rc!=SQLITE_OK ) return rc;

  173299. 

  173300.     nData = 0;

  173301.     pWriter->nTerm = 0;

  173302. 

  173303.     nPrefix = 0;

  173304.     nSuffix = nTerm;

  173305.     nReq = 1 +                              /* varint containing prefix size */

  173306.       sqlite3Fts3VarintLen(nTerm) +         /* varint containing suffix size */

  173307.       nTerm +                               /* Term suffix */

  173308.       sqlite3Fts3VarintLen(nDoclist) +      /* Size of doclist */

  173309.       nDoclist;                             /* Doclist data */

  173310.   }

  173311. 

  173312.   /* Increase the total number of bytes written to account for the new entry. */

  173313.   pWriter->nLeafData += nReq;

  173314. 

  173315.   /* If the buffer currently allocated is too small for this entry, realloc

  173316.   ** the buffer to make it large enough.

  173317.   */

  173318.   if( nReq>pWriter->nSize ){

  173319.     char *aNew = sqlite3_realloc(pWriter->aData, nReq);

  173320.     if( !aNew ) return SQLITE_NOMEM;

  173321.     pWriter->aData = aNew;

  173322.     pWriter->nSize = nReq;

  173323.   }

  173324.   assert( nData+nReq<=pWriter->nSize );

  173325. 

  173326.   /* Append the prefix-compressed term and doclist to the buffer. */

  173327.   nData += sqlite3Fts3PutVarint(&pWriter->aData[nData], nPrefix);

  173328.   nData += sqlite3Fts3PutVarint(&pWriter->aData[nData], nSuffix);

  173329.   memcpy(&pWriter->aData[nData], &zTerm[nPrefix], nSuffix);

  173330.   nData += nSuffix;

  173331.   nData += sqlite3Fts3PutVarint(&pWriter->aData[nData], nDoclist);

  173332.   memcpy(&pWriter->aData[nData], aDoclist, nDoclist);

  173333.   pWriter->nData = nData + nDoclist;

  173334. 

  173335.   /* Save the current term so that it can be used to prefix-compress the next.

  173336.   ** If the isCopyTerm parameter is true, then the buffer pointed to by

  173337.   ** zTerm is transient, so take a copy of the term data. Otherwise, just

  173338.   ** store a copy of the pointer.

  173339.   */

  173340.   if( isCopyTerm ){

  173341.     if( nTerm>pWriter->nMalloc ){

  173342.       char *zNew = sqlite3_realloc(pWriter->zMalloc, nTerm*2);

  173343.       if( !zNew ){

  173344.         return SQLITE_NOMEM;

  173345.       }

  173346.       pWriter->nMalloc = nTerm*2;

  173347.       pWriter->zMalloc = zNew;

  173348.       pWriter->zTerm = zNew;

  173349.     }

  173350.     assert( pWriter->zTerm==pWriter->zMalloc );

  173351.     memcpy(pWriter->zTerm, zTerm, nTerm);

  173352.   }else{

  173353.     pWriter->zTerm = (char *)zTerm;

  173354.   }

  173355.   pWriter->nTerm = nTerm;

  173356. 

  173357.   return SQLITE_OK;

  173358. }

  173359. 

  173360. /*

  173361. ** Flush all data associated with the SegmentWriter object pWriter to the

  173362. ** database. This function must be called after all terms have been added

  173363. ** to the segment using fts3SegWriterAdd(). If successful, SQLITE_OK is

  173364. ** returned. Otherwise, an SQLite error code.

  173365. */

  173366. static int fts3SegWriterFlush(

  173367.   Fts3Table *p,                   /* Virtual table handle */

  173368.   SegmentWriter *pWriter,         /* SegmentWriter to flush to the db */

  173369.   sqlite3_int64 iLevel,           /* Value for 'level' column of %_segdir */

  173370.   int iIdx                        /* Value for 'idx' column of %_segdir */

  173371. ){

  173372.   int rc;                         /* Return code */

  173373.   if( pWriter->pTree ){

  173374.     sqlite3_int64 iLast = 0;      /* Largest block id written to database */

  173375.     sqlite3_int64 iLastLeaf;      /* Largest leaf block id written to db */

  173376.     char *zRoot = NULL;           /* Pointer to buffer containing root node */

  173377.     int nRoot = 0;                /* Size of buffer zRoot */

  173378. 

  173379.     iLastLeaf = pWriter->iFree;

  173380.     rc = fts3WriteSegment(p, pWriter->iFree++, pWriter->aData, pWriter->nData);

  173381.     if( rc==SQLITE_OK ){

  173382.       rc = fts3NodeWrite(p, pWriter->pTree, 1,

  173383.           pWriter->iFirst, pWriter->iFree, &iLast, &zRoot, &nRoot);

  173384.     }

  173385.     if( rc==SQLITE_OK ){

  173386.       rc = fts3WriteSegdir(p, iLevel, iIdx, 

  173387.           pWriter->iFirst, iLastLeaf, iLast, pWriter->nLeafData, zRoot, nRoot);

  173388.     }

  173389.   }else{

  173390.     /* The entire tree fits on the root node. Write it to the segdir table. */

  173391.     rc = fts3WriteSegdir(p, iLevel, iIdx, 

  173392.         0, 0, 0, pWriter->nLeafData, pWriter->aData, pWriter->nData);

  173393.   }

  173394.   p->nLeafAdd++;

  173395.   return rc;

  173396. }

  173397. 

  173398. /*

  173399. ** Release all memory held by the SegmentWriter object passed as the 

  173400. ** first argument.

  173401. */

  173402. static void fts3SegWriterFree(SegmentWriter *pWriter){

  173403.   if( pWriter ){

  173404.     sqlite3_free(pWriter->aData);

  173405.     sqlite3_free(pWriter->zMalloc);

  173406.     fts3NodeFree(pWriter->pTree);

  173407.     sqlite3_free(pWriter);

  173408.   }

  173409. }

  173410. 

  173411. /*

  173412. ** The first value in the apVal[] array is assumed to contain an integer.

  173413. ** This function tests if there exist any documents with docid values that

  173414. ** are different from that integer. i.e. if deleting the document with docid

  173415. ** pRowid would mean the FTS3 table were empty.

  173416. **

  173417. ** If successful, *pisEmpty is set to true if the table is empty except for

  173418. ** document pRowid, or false otherwise, and SQLITE_OK is returned. If an

  173419. ** error occurs, an SQLite error code is returned.

  173420. */

  173421. static int fts3IsEmpty(Fts3Table *p, sqlite3_value *pRowid, int *pisEmpty){

  173422.   sqlite3_stmt *pStmt;

  173423.   int rc;

  173424.   if( p->zContentTbl ){

  173425.     /* If using the content=xxx option, assume the table is never empty */

  173426.     *pisEmpty = 0;

  173427.     rc = SQLITE_OK;

  173428.   }else{

  173429.     rc = fts3SqlStmt(p, SQL_IS_EMPTY, &pStmt, &pRowid);

  173430.     if( rc==SQLITE_OK ){

  173431.       if( SQLITE_ROW==sqlite3_step(pStmt) ){

  173432.         *pisEmpty = sqlite3_column_int(pStmt, 0);

  173433.       }

  173434.       rc = sqlite3_reset(pStmt);

  173435.     }

  173436.   }

  173437.   return rc;

  173438. }

  173439. 

  173440. /*

  173441. ** Set *pnMax to the largest segment level in the database for the index

  173442. ** iIndex.

  173443. **

  173444. ** Segment levels are stored in the 'level' column of the %_segdir table.

  173445. **

  173446. ** Return SQLITE_OK if successful, or an SQLite error code if not.

  173447. */

  173448. static int fts3SegmentMaxLevel(

  173449.   Fts3Table *p, 

  173450.   int iLangid,

  173451.   int iIndex, 

  173452.   sqlite3_int64 *pnMax

  173453. ){

  173454.   sqlite3_stmt *pStmt;

  173455.   int rc;

  173456.   assert( iIndex>=0 && iIndex<p->nIndex );

  173457. 

  173458.   /* Set pStmt to the compiled version of:

  173459.   **

  173460.   **   SELECT max(level) FROM %Q.'%q_segdir' WHERE level BETWEEN ? AND ?

  173461.   **

  173462.   ** (1024 is actually the value of macro FTS3_SEGDIR_PREFIXLEVEL_STR).

  173463.   */

  173464.   rc = fts3SqlStmt(p, SQL_SELECT_SEGDIR_MAX_LEVEL, &pStmt, 0);

  173465.   if( rc!=SQLITE_OK ) return rc;

  173466.   sqlite3_bind_int64(pStmt, 1, getAbsoluteLevel(p, iLangid, iIndex, 0));

  173467.   sqlite3_bind_int64(pStmt, 2, 

  173468.       getAbsoluteLevel(p, iLangid, iIndex, FTS3_SEGDIR_MAXLEVEL-1)

  173469.   );

  173470.   if( SQLITE_ROW==sqlite3_step(pStmt) ){

  173471.     *pnMax = sqlite3_column_int64(pStmt, 0);

  173472.   }

  173473.   return sqlite3_reset(pStmt);

  173474. }

  173475. 

  173476. /*

  173477. ** iAbsLevel is an absolute level that may be assumed to exist within

  173478. ** the database. This function checks if it is the largest level number

  173479. ** within its index. Assuming no error occurs, *pbMax is set to 1 if

  173480. ** iAbsLevel is indeed the largest level, or 0 otherwise, and SQLITE_OK

  173481. ** is returned. If an error occurs, an error code is returned and the

  173482. ** final value of *pbMax is undefined.

  173483. */

  173484. static int fts3SegmentIsMaxLevel(Fts3Table *p, i64 iAbsLevel, int *pbMax){

  173485. 

  173486.   /* Set pStmt to the compiled version of:

  173487.   **

  173488.   **   SELECT max(level) FROM %Q.'%q_segdir' WHERE level BETWEEN ? AND ?

  173489.   **

  173490.   ** (1024 is actually the value of macro FTS3_SEGDIR_PREFIXLEVEL_STR).

  173491.   */

  173492.   sqlite3_stmt *pStmt;

  173493.   int rc = fts3SqlStmt(p, SQL_SELECT_SEGDIR_MAX_LEVEL, &pStmt, 0);

  173494.   if( rc!=SQLITE_OK ) return rc;

  173495.   sqlite3_bind_int64(pStmt, 1, iAbsLevel+1);

  173496.   sqlite3_bind_int64(pStmt, 2, 

  173497.       ((iAbsLevel/FTS3_SEGDIR_MAXLEVEL)+1) * FTS3_SEGDIR_MAXLEVEL

  173498.   );

  173499. 

  173500.   *pbMax = 0;

  173501.   if( SQLITE_ROW==sqlite3_step(pStmt) ){

  173502.     *pbMax = sqlite3_column_type(pStmt, 0)==SQLITE_NULL;

  173503.   }

  173504.   return sqlite3_reset(pStmt);

  173505. }

  173506. 

  173507. /*

  173508. ** Delete all entries in the %_segments table associated with the segment

  173509. ** opened with seg-reader pSeg. This function does not affect the contents

  173510. ** of the %_segdir table.

  173511. */

  173512. static int fts3DeleteSegment(

  173513.   Fts3Table *p,                   /* FTS table handle */

  173514.   Fts3SegReader *pSeg             /* Segment to delete */

  173515. ){

  173516.   int rc = SQLITE_OK;             /* Return code */

  173517.   if( pSeg->iStartBlock ){

  173518.     sqlite3_stmt *pDelete;        /* SQL statement to delete rows */

  173519.     rc = fts3SqlStmt(p, SQL_DELETE_SEGMENTS_RANGE, &pDelete, 0);

  173520.     if( rc==SQLITE_OK ){

  173521.       sqlite3_bind_int64(pDelete, 1, pSeg->iStartBlock);

  173522.       sqlite3_bind_int64(pDelete, 2, pSeg->iEndBlock);

  173523.       sqlite3_step(pDelete);

  173524.       rc = sqlite3_reset(pDelete);

  173525.     }

  173526.   }

  173527.   return rc;

  173528. }

  173529. 

  173530. /*

  173531. ** This function is used after merging multiple segments into a single large

  173532. ** segment to delete the old, now redundant, segment b-trees. Specifically,

  173533. ** it:

  173534. ** 

  173535. **   1) Deletes all %_segments entries for the segments associated with 

  173536. **      each of the SegReader objects in the array passed as the third 

  173537. **      argument, and

  173538. **

  173539. **   2) deletes all %_segdir entries with level iLevel, or all %_segdir

  173540. **      entries regardless of level if (iLevel<0).

  173541. **

  173542. ** SQLITE_OK is returned if successful, otherwise an SQLite error code.

  173543. */

  173544. static int fts3DeleteSegdir(

  173545.   Fts3Table *p,                   /* Virtual table handle */

  173546.   int iLangid,                    /* Language id */

  173547.   int iIndex,                     /* Index for p->aIndex */

  173548.   int iLevel,                     /* Level of %_segdir entries to delete */

  173549.   Fts3SegReader **apSegment,      /* Array of SegReader objects */

  173550.   int nReader                     /* Size of array apSegment */

  173551. ){

  173552.   int rc = SQLITE_OK;             /* Return Code */

  173553.   int i;                          /* Iterator variable */

  173554.   sqlite3_stmt *pDelete = 0;      /* SQL statement to delete rows */

  173555. 

  173556.   for(i=0; rc==SQLITE_OK && i<nReader; i++){

  173557.     rc = fts3DeleteSegment(p, apSegment[i]);

  173558.   }

  173559.   if( rc!=SQLITE_OK ){

  173560.     return rc;

  173561.   }

  173562. 

  173563.   assert( iLevel>=0 || iLevel==FTS3_SEGCURSOR_ALL );

  173564.   if( iLevel==FTS3_SEGCURSOR_ALL ){

  173565.     rc = fts3SqlStmt(p, SQL_DELETE_SEGDIR_RANGE, &pDelete, 0);

  173566.     if( rc==SQLITE_OK ){

  173567.       sqlite3_bind_int64(pDelete, 1, getAbsoluteLevel(p, iLangid, iIndex, 0));

  173568.       sqlite3_bind_int64(pDelete, 2, 

  173569.           getAbsoluteLevel(p, iLangid, iIndex, FTS3_SEGDIR_MAXLEVEL-1)

  173570.       );

  173571.     }

  173572.   }else{

  173573.     rc = fts3SqlStmt(p, SQL_DELETE_SEGDIR_LEVEL, &pDelete, 0);

  173574.     if( rc==SQLITE_OK ){

  173575.       sqlite3_bind_int64(

  173576.           pDelete, 1, getAbsoluteLevel(p, iLangid, iIndex, iLevel)

  173577.       );

  173578.     }

  173579.   }

  173580. 

  173581.   if( rc==SQLITE_OK ){

  173582.     sqlite3_step(pDelete);

  173583.     rc = sqlite3_reset(pDelete);

  173584.   }

  173585. 

  173586.   return rc;

  173587. }

  173588. 

  173589. /*

  173590. ** When this function is called, buffer *ppList (size *pnList bytes) contains 

  173591. ** a position list that may (or may not) feature multiple columns. This

  173592. ** function adjusts the pointer *ppList and the length *pnList so that they

  173593. ** identify the subset of the position list that corresponds to column iCol.

  173594. **

  173595. ** If there are no entries in the input position list for column iCol, then

  173596. ** *pnList is set to zero before returning.

  173597. **

  173598. ** If parameter bZero is non-zero, then any part of the input list following

  173599. ** the end of the output list is zeroed before returning.

  173600. */

  173601. static void fts3ColumnFilter(

  173602.   int iCol,                       /* Column to filter on */

  173603.   int bZero,                      /* Zero out anything following *ppList */

  173604.   char **ppList,                  /* IN/OUT: Pointer to position list */

  173605.   int *pnList                     /* IN/OUT: Size of buffer *ppList in bytes */

  173606. ){

  173607.   char *pList = *ppList;

  173608.   int nList = *pnList;

  173609.   char *pEnd = &pList[nList];

  173610.   int iCurrent = 0;

  173611.   char *p = pList;

  173612. 

  173613.   assert( iCol>=0 );

  173614.   while( 1 ){

  173615.     char c = 0;

  173616.     while( p<pEnd && (c | *p)&0xFE ) c = *p++ & 0x80;

  173617.   

  173618.     if( iCol==iCurrent ){

  173619.       nList = (int)(p - pList);

  173620.       break;

  173621.     }

  173622. 

  173623.     nList -= (int)(p - pList);

  173624.     pList = p;

  173625.     if( nList<=0 ){

  173626.       break;

  173627.     }

  173628.     p = &pList[1];

  173629.     p += fts3GetVarint32(p, &iCurrent);

  173630.   }

  173631. 

  173632.   if( bZero && (pEnd - &pList[nList])>0){

  173633.     memset(&pList[nList], 0, pEnd - &pList[nList]);

  173634.   }

  173635.   *ppList = pList;

  173636.   *pnList = nList;

  173637. }

  173638. 

  173639. /*

  173640. ** Cache data in the Fts3MultiSegReader.aBuffer[] buffer (overwriting any

  173641. ** existing data). Grow the buffer if required.

  173642. **

  173643. ** If successful, return SQLITE_OK. Otherwise, if an OOM error is encountered

  173644. ** trying to resize the buffer, return SQLITE_NOMEM.

  173645. */

  173646. static int fts3MsrBufferData(

  173647.   Fts3MultiSegReader *pMsr,       /* Multi-segment-reader handle */

  173648.   char *pList,

  173649.   int nList

  173650. ){

  173651.   if( nList>pMsr->nBuffer ){

  173652.     char *pNew;

  173653.     pMsr->nBuffer = nList*2;

  173654.     pNew = (char *)sqlite3_realloc(pMsr->aBuffer, pMsr->nBuffer);

  173655.     if( !pNew ) return SQLITE_NOMEM;

  173656.     pMsr->aBuffer = pNew;

  173657.   }

  173658. 

  173659.   memcpy(pMsr->aBuffer, pList, nList);

  173660.   return SQLITE_OK;

  173661. }

  173662. 

  173663. SQLITE_PRIVATE int sqlite3Fts3MsrIncrNext(

  173664.   Fts3Table *p,                   /* Virtual table handle */

  173665.   Fts3MultiSegReader *pMsr,       /* Multi-segment-reader handle */

  173666.   sqlite3_int64 *piDocid,         /* OUT: Docid value */

  173667.   char **paPoslist,               /* OUT: Pointer to position list */

  173668.   int *pnPoslist                  /* OUT: Size of position list in bytes */

  173669. ){

  173670.   int nMerge = pMsr->nAdvance;

  173671.   Fts3SegReader **apSegment = pMsr->apSegment;

  173672.   int (*xCmp)(Fts3SegReader *, Fts3SegReader *) = (

  173673.     p->bDescIdx ? fts3SegReaderDoclistCmpRev : fts3SegReaderDoclistCmp

  173674.   );

  173675. 

  173676.   if( nMerge==0 ){

  173677.     *paPoslist = 0;

  173678.     return SQLITE_OK;

  173679.   }

  173680. 

  173681.   while( 1 ){

  173682.     Fts3SegReader *pSeg;

  173683.     pSeg = pMsr->apSegment[0];

  173684. 

  173685.     if( pSeg->pOffsetList==0 ){

  173686.       *paPoslist = 0;

  173687.       break;

  173688.     }else{

  173689.       int rc;

  173690.       char *pList;

  173691.       int nList;

  173692.       int j;

  173693.       sqlite3_int64 iDocid = apSegment[0]->iDocid;

  173694. 

  173695.       rc = fts3SegReaderNextDocid(p, apSegment[0], &pList, &nList);

  173696.       j = 1;

  173697.       while( rc==SQLITE_OK 

  173698.         && j<nMerge

  173699.         && apSegment[j]->pOffsetList

  173700.         && apSegment[j]->iDocid==iDocid

  173701.       ){

  173702.         rc = fts3SegReaderNextDocid(p, apSegment[j], 0, 0);

  173703.         j++;

  173704.       }

  173705.       if( rc!=SQLITE_OK ) return rc;

  173706.       fts3SegReaderSort(pMsr->apSegment, nMerge, j, xCmp);

  173707. 

  173708.       if( nList>0 && fts3SegReaderIsPending(apSegment[0]) ){

  173709.         rc = fts3MsrBufferData(pMsr, pList, nList+1);

  173710.         if( rc!=SQLITE_OK ) return rc;

  173711.         assert( (pMsr->aBuffer[nList] & 0xFE)==0x00 );

  173712.         pList = pMsr->aBuffer;

  173713.       }

  173714. 

  173715.       if( pMsr->iColFilter>=0 ){

  173716.         fts3ColumnFilter(pMsr->iColFilter, 1, &pList, &nList);

  173717.       }

  173718. 

  173719.       if( nList>0 ){

  173720.         *paPoslist = pList;

  173721.         *piDocid = iDocid;

  173722.         *pnPoslist = nList;

  173723.         break;

  173724.       }

  173725.     }

  173726.   }

  173727. 

  173728.   return SQLITE_OK;

  173729. }

  173730. 

  173731. static int fts3SegReaderStart(

  173732.   Fts3Table *p,                   /* Virtual table handle */

  173733.   Fts3MultiSegReader *pCsr,       /* Cursor object */

  173734.   const char *zTerm,              /* Term searched for (or NULL) */

  173735.   int nTerm                       /* Length of zTerm in bytes */

  173736. ){

  173737.   int i;

  173738.   int nSeg = pCsr->nSegment;

  173739. 

  173740.   /* If the Fts3SegFilter defines a specific term (or term prefix) to search 

  173741.   ** for, then advance each segment iterator until it points to a term of

  173742.   ** equal or greater value than the specified term. This prevents many

  173743.   ** unnecessary merge/sort operations for the case where single segment

  173744.   ** b-tree leaf nodes contain more than one term.

  173745.   */

  173746.   for(i=0; pCsr->bRestart==0 && i<pCsr->nSegment; i++){

  173747.     int res = 0;

  173748.     Fts3SegReader *pSeg = pCsr->apSegment[i];

  173749.     do {

  173750.       int rc = fts3SegReaderNext(p, pSeg, 0);

  173751.       if( rc!=SQLITE_OK ) return rc;

  173752.     }while( zTerm && (res = fts3SegReaderTermCmp(pSeg, zTerm, nTerm))<0 );

  173753. 

  173754.     if( pSeg->bLookup && res!=0 ){

  173755.       fts3SegReaderSetEof(pSeg);

  173756.     }

  173757.   }

  173758.   fts3SegReaderSort(pCsr->apSegment, nSeg, nSeg, fts3SegReaderCmp);

  173759. 

  173760.   return SQLITE_OK;

  173761. }

  173762. 

  173763. SQLITE_PRIVATE int sqlite3Fts3SegReaderStart(

  173764.   Fts3Table *p,                   /* Virtual table handle */

  173765.   Fts3MultiSegReader *pCsr,       /* Cursor object */

  173766.   Fts3SegFilter *pFilter          /* Restrictions on range of iteration */

  173767. ){

  173768.   pCsr->pFilter = pFilter;

  173769.   return fts3SegReaderStart(p, pCsr, pFilter->zTerm, pFilter->nTerm);

  173770. }

  173771. 

  173772. SQLITE_PRIVATE int sqlite3Fts3MsrIncrStart(

  173773.   Fts3Table *p,                   /* Virtual table handle */

  173774.   Fts3MultiSegReader *pCsr,       /* Cursor object */

  173775.   int iCol,                       /* Column to match on. */

  173776.   const char *zTerm,              /* Term to iterate through a doclist for */

  173777.   int nTerm                       /* Number of bytes in zTerm */

  173778. ){

  173779.   int i;

  173780.   int rc;

  173781.   int nSegment = pCsr->nSegment;

  173782.   int (*xCmp)(Fts3SegReader *, Fts3SegReader *) = (

  173783.     p->bDescIdx ? fts3SegReaderDoclistCmpRev : fts3SegReaderDoclistCmp

  173784.   );

  173785. 

  173786.   assert( pCsr->pFilter==0 );

  173787.   assert( zTerm && nTerm>0 );

  173788. 

  173789.   /* Advance each segment iterator until it points to the term zTerm/nTerm. */

  173790.   rc = fts3SegReaderStart(p, pCsr, zTerm, nTerm);

  173791.   if( rc!=SQLITE_OK ) return rc;

  173792. 

  173793.   /* Determine how many of the segments actually point to zTerm/nTerm. */

  173794.   for(i=0; i<nSegment; i++){

  173795.     Fts3SegReader *pSeg = pCsr->apSegment[i];

  173796.     if( !pSeg->aNode || fts3SegReaderTermCmp(pSeg, zTerm, nTerm) ){

  173797.       break;

  173798.     }

  173799.   }

  173800.   pCsr->nAdvance = i;

  173801. 

  173802.   /* Advance each of the segments to point to the first docid. */

  173803.   for(i=0; i<pCsr->nAdvance; i++){

  173804.     rc = fts3SegReaderFirstDocid(p, pCsr->apSegment[i]);

  173805.     if( rc!=SQLITE_OK ) return rc;

  173806.   }

  173807.   fts3SegReaderSort(pCsr->apSegment, i, i, xCmp);

  173808. 

  173809.   assert( iCol<0 || iCol<p->nColumn );

  173810.   pCsr->iColFilter = iCol;

  173811. 

  173812.   return SQLITE_OK;

  173813. }

  173814. 

  173815. /*

  173816. ** This function is called on a MultiSegReader that has been started using

  173817. ** sqlite3Fts3MsrIncrStart(). One or more calls to MsrIncrNext() may also

  173818. ** have been made. Calling this function puts the MultiSegReader in such

  173819. ** a state that if the next two calls are:

  173820. **

  173821. **   sqlite3Fts3SegReaderStart()

  173822. **   sqlite3Fts3SegReaderStep()

  173823. **

  173824. ** then the entire doclist for the term is available in 

  173825. ** MultiSegReader.aDoclist/nDoclist.

  173826. */

  173827. SQLITE_PRIVATE int sqlite3Fts3MsrIncrRestart(Fts3MultiSegReader *pCsr){

  173828.   int i;                          /* Used to iterate through segment-readers */

  173829. 

  173830.   assert( pCsr->zTerm==0 );

  173831.   assert( pCsr->nTerm==0 );

  173832.   assert( pCsr->aDoclist==0 );

  173833.   assert( pCsr->nDoclist==0 );

  173834. 

  173835.   pCsr->nAdvance = 0;

  173836.   pCsr->bRestart = 1;

  173837.   for(i=0; i<pCsr->nSegment; i++){

  173838.     pCsr->apSegment[i]->pOffsetList = 0;

  173839.     pCsr->apSegment[i]->nOffsetList = 0;

  173840.     pCsr->apSegment[i]->iDocid = 0;

  173841.   }

  173842. 

  173843.   return SQLITE_OK;

  173844. }

  173845. 

  173846. 

  173847. SQLITE_PRIVATE int sqlite3Fts3SegReaderStep(

  173848.   Fts3Table *p,                   /* Virtual table handle */

  173849.   Fts3MultiSegReader *pCsr        /* Cursor object */

  173850. ){

  173851.   int rc = SQLITE_OK;

  173852. 

  173853.   int isIgnoreEmpty =  (pCsr->pFilter->flags & FTS3_SEGMENT_IGNORE_EMPTY);

  173854.   int isRequirePos =   (pCsr->pFilter->flags & FTS3_SEGMENT_REQUIRE_POS);

  173855.   int isColFilter =    (pCsr->pFilter->flags & FTS3_SEGMENT_COLUMN_FILTER);

  173856.   int isPrefix =       (pCsr->pFilter->flags & FTS3_SEGMENT_PREFIX);

  173857.   int isScan =         (pCsr->pFilter->flags & FTS3_SEGMENT_SCAN);

  173858.   int isFirst =        (pCsr->pFilter->flags & FTS3_SEGMENT_FIRST);

  173859. 

  173860.   Fts3SegReader **apSegment = pCsr->apSegment;

  173861.   int nSegment = pCsr->nSegment;

  173862.   Fts3SegFilter *pFilter = pCsr->pFilter;

  173863.   int (*xCmp)(Fts3SegReader *, Fts3SegReader *) = (

  173864.     p->bDescIdx ? fts3SegReaderDoclistCmpRev : fts3SegReaderDoclistCmp

  173865.   );

  173866. 

  173867.   if( pCsr->nSegment==0 ) return SQLITE_OK;

  173868. 

  173869.   do {

  173870.     int nMerge;

  173871.     int i;

  173872.   

  173873.     /* Advance the first pCsr->nAdvance entries in the apSegment[] array

  173874.     ** forward. Then sort the list in order of current term again.  

  173875.     */

  173876.     for(i=0; i<pCsr->nAdvance; i++){

  173877.       Fts3SegReader *pSeg = apSegment[i];

  173878.       if( pSeg->bLookup ){

  173879.         fts3SegReaderSetEof(pSeg);

  173880.       }else{

  173881.         rc = fts3SegReaderNext(p, pSeg, 0);

  173882.       }

  173883.       if( rc!=SQLITE_OK ) return rc;

  173884.     }

  173885.     fts3SegReaderSort(apSegment, nSegment, pCsr->nAdvance, fts3SegReaderCmp);

  173886.     pCsr->nAdvance = 0;

  173887. 

  173888.     /* If all the seg-readers are at EOF, we're finished. return SQLITE_OK. */

  173889.     assert( rc==SQLITE_OK );

  173890.     if( apSegment[0]->aNode==0 ) break;

  173891. 

  173892.     pCsr->nTerm = apSegment[0]->nTerm;

  173893.     pCsr->zTerm = apSegment[0]->zTerm;

  173894. 

  173895.     /* If this is a prefix-search, and if the term that apSegment[0] points

  173896.     ** to does not share a suffix with pFilter->zTerm/nTerm, then all 

  173897.     ** required callbacks have been made. In this case exit early.

  173898.     **

  173899.     ** Similarly, if this is a search for an exact match, and the first term

  173900.     ** of segment apSegment[0] is not a match, exit early.

  173901.     */

  173902.     if( pFilter->zTerm && !isScan ){

  173903.       if( pCsr->nTerm<pFilter->nTerm 

  173904.        || (!isPrefix && pCsr->nTerm>pFilter->nTerm)

  173905.        || memcmp(pCsr->zTerm, pFilter->zTerm, pFilter->nTerm) 

  173906.       ){

  173907.         break;

  173908.       }

  173909.     }

  173910. 

  173911.     nMerge = 1;

  173912.     while( nMerge<nSegment 

  173913.         && apSegment[nMerge]->aNode

  173914.         && apSegment[nMerge]->nTerm==pCsr->nTerm 

  173915.         && 0==memcmp(pCsr->zTerm, apSegment[nMerge]->zTerm, pCsr->nTerm)

  173916.     ){

  173917.       nMerge++;

  173918.     }

  173919. 

  173920.     assert( isIgnoreEmpty || (isRequirePos && !isColFilter) );

  173921.     if( nMerge==1 

  173922.      && !isIgnoreEmpty 

  173923.      && !isFirst 

  173924.      && (p->bDescIdx==0 || fts3SegReaderIsPending(apSegment[0])==0)

  173925.     ){

  173926.       pCsr->nDoclist = apSegment[0]->nDoclist;

  173927.       if( fts3SegReaderIsPending(apSegment[0]) ){

  173928.         rc = fts3MsrBufferData(pCsr, apSegment[0]->aDoclist, pCsr->nDoclist);

  173929.         pCsr->aDoclist = pCsr->aBuffer;

  173930.       }else{

  173931.         pCsr->aDoclist = apSegment[0]->aDoclist;

  173932.       }

  173933.       if( rc==SQLITE_OK ) rc = SQLITE_ROW;

  173934.     }else{

  173935.       int nDoclist = 0;           /* Size of doclist */

  173936.       sqlite3_int64 iPrev = 0;    /* Previous docid stored in doclist */

  173937. 

  173938.       /* The current term of the first nMerge entries in the array

  173939.       ** of Fts3SegReader objects is the same. The doclists must be merged

  173940.       ** and a single term returned with the merged doclist.

  173941.       */

  173942.       for(i=0; i<nMerge; i++){

  173943.         fts3SegReaderFirstDocid(p, apSegment[i]);

  173944.       }

  173945.       fts3SegReaderSort(apSegment, nMerge, nMerge, xCmp);

  173946.       while( apSegment[0]->pOffsetList ){

  173947.         int j;                    /* Number of segments that share a docid */

  173948.         char *pList = 0;

  173949.         int nList = 0;

  173950.         int nByte;

  173951.         sqlite3_int64 iDocid = apSegment[0]->iDocid;

  173952.         fts3SegReaderNextDocid(p, apSegment[0], &pList, &nList);

  173953.         j = 1;

  173954.         while( j<nMerge

  173955.             && apSegment[j]->pOffsetList

  173956.             && apSegment[j]->iDocid==iDocid

  173957.         ){

  173958.           fts3SegReaderNextDocid(p, apSegment[j], 0, 0);

  173959.           j++;

  173960.         }

  173961. 

  173962.         if( isColFilter ){

  173963.           fts3ColumnFilter(pFilter->iCol, 0, &pList, &nList);

  173964.         }

  173965. 

  173966.         if( !isIgnoreEmpty || nList>0 ){

  173967. 

  173968.           /* Calculate the 'docid' delta value to write into the merged 

  173969.           ** doclist. */

  173970.           sqlite3_int64 iDelta;

  173971.           if( p->bDescIdx && nDoclist>0 ){

  173972.             iDelta = iPrev - iDocid;

  173973.           }else{

  173974.             iDelta = iDocid - iPrev;

  173975.           }

  173976.           if( iDelta<=0 && (nDoclist>0 || iDelta!=iDocid) ){

  173977.             return FTS_CORRUPT_VTAB;

  173978.           }

  173979.           assert( nDoclist>0 || iDelta==iDocid );

  173980. 

  173981.           nByte = sqlite3Fts3VarintLen(iDelta) + (isRequirePos?nList+1:0);

  173982.           if( nDoclist+nByte>pCsr->nBuffer ){

  173983.             char *aNew;

  173984.             pCsr->nBuffer = (nDoclist+nByte)*2;

  173985.             aNew = sqlite3_realloc(pCsr->aBuffer, pCsr->nBuffer);

  173986.             if( !aNew ){

  173987.               return SQLITE_NOMEM;

  173988.             }

  173989.             pCsr->aBuffer = aNew;

  173990.           }

  173991. 

  173992.           if( isFirst ){

  173993.             char *a = &pCsr->aBuffer[nDoclist];

  173994.             int nWrite;

  173995.            

  173996.             nWrite = sqlite3Fts3FirstFilter(iDelta, pList, nList, a);

  173997.             if( nWrite ){

  173998.               iPrev = iDocid;

  173999.               nDoclist += nWrite;

  174000.             }

  174001.           }else{

  174002.             nDoclist += sqlite3Fts3PutVarint(&pCsr->aBuffer[nDoclist], iDelta);

  174003.             iPrev = iDocid;

  174004.             if( isRequirePos ){

  174005.               memcpy(&pCsr->aBuffer[nDoclist], pList, nList);

  174006.               nDoclist += nList;

  174007.               pCsr->aBuffer[nDoclist++] = '\0';

  174008.             }

  174009.           }

  174010.         }

  174011. 

  174012.         fts3SegReaderSort(apSegment, nMerge, j, xCmp);

  174013.       }

  174014.       if( nDoclist>0 ){

  174015.         pCsr->aDoclist = pCsr->aBuffer;

  174016.         pCsr->nDoclist = nDoclist;

  174017.         rc = SQLITE_ROW;

  174018.       }

  174019.     }

  174020.     pCsr->nAdvance = nMerge;

  174021.   }while( rc==SQLITE_OK );

  174022. 

  174023.   return rc;

  174024. }

  174025. 

  174026. 

  174027. SQLITE_PRIVATE void sqlite3Fts3SegReaderFinish(

  174028.   Fts3MultiSegReader *pCsr       /* Cursor object */

  174029. ){

  174030.   if( pCsr ){

  174031.     int i;

  174032.     for(i=0; i<pCsr->nSegment; i++){

  174033.       sqlite3Fts3SegReaderFree(pCsr->apSegment[i]);

  174034.     }

  174035.     sqlite3_free(pCsr->apSegment);

  174036.     sqlite3_free(pCsr->aBuffer);

  174037. 

  174038.     pCsr->nSegment = 0;

  174039.     pCsr->apSegment = 0;

  174040.     pCsr->aBuffer = 0;

  174041.   }

  174042. }

  174043. 

  174044. /*

  174045. ** Decode the "end_block" field, selected by column iCol of the SELECT 

  174046. ** statement passed as the first argument. 

  174047. **

  174048. ** The "end_block" field may contain either an integer, or a text field

  174049. ** containing the text representation of two non-negative integers separated 

  174050. ** by one or more space (0x20) characters. In the first case, set *piEndBlock 

  174051. ** to the integer value and *pnByte to zero before returning. In the second, 

  174052. ** set *piEndBlock to the first value and *pnByte to the second.

  174053. */

  174054. static void fts3ReadEndBlockField(

  174055.   sqlite3_stmt *pStmt, 

  174056.   int iCol, 

  174057.   i64 *piEndBlock,

  174058.   i64 *pnByte

  174059. ){

  174060.   const unsigned char *zText = sqlite3_column_text(pStmt, iCol);

  174061.   if( zText ){

  174062.     int i;

  174063.     int iMul = 1;

  174064.     i64 iVal = 0;

  174065.     for(i=0; zText[i]>='0' && zText[i]<='9'; i++){

  174066.       iVal = iVal*10 + (zText[i] - '0');

  174067.     }

  174068.     *piEndBlock = iVal;

  174069.     while( zText[i]==' ' ) i++;

  174070.     iVal = 0;

  174071.     if( zText[i]=='-' ){

  174072.       i++;

  174073.       iMul = -1;

  174074.     }

  174075.     for(/* no-op */; zText[i]>='0' && zText[i]<='9'; i++){

  174076.       iVal = iVal*10 + (zText[i] - '0');

  174077.     }

  174078.     *pnByte = (iVal * (i64)iMul);

  174079.   }

  174080. }

  174081. 

  174082. 

  174083. /*

  174084. ** A segment of size nByte bytes has just been written to absolute level

  174085. ** iAbsLevel. Promote any segments that should be promoted as a result.

  174086. */

  174087. static int fts3PromoteSegments(

  174088.   Fts3Table *p,                   /* FTS table handle */

  174089.   sqlite3_int64 iAbsLevel,        /* Absolute level just updated */

  174090.   sqlite3_int64 nByte             /* Size of new segment at iAbsLevel */

  174091. ){

  174092.   int rc = SQLITE_OK;

  174093.   sqlite3_stmt *pRange;

  174094. 

  174095.   rc = fts3SqlStmt(p, SQL_SELECT_LEVEL_RANGE2, &pRange, 0);

  174096. 

  174097.   if( rc==SQLITE_OK ){

  174098.     int bOk = 0;

  174099.     i64 iLast = (iAbsLevel/FTS3_SEGDIR_MAXLEVEL + 1) * FTS3_SEGDIR_MAXLEVEL - 1;

  174100.     i64 nLimit = (nByte*3)/2;

  174101. 

  174102.     /* Loop through all entries in the %_segdir table corresponding to 

  174103.     ** segments in this index on levels greater than iAbsLevel. If there is

  174104.     ** at least one such segment, and it is possible to determine that all 

  174105.     ** such segments are smaller than nLimit bytes in size, they will be 

  174106.     ** promoted to level iAbsLevel.  */

  174107.     sqlite3_bind_int64(pRange, 1, iAbsLevel+1);

  174108.     sqlite3_bind_int64(pRange, 2, iLast);

  174109.     while( SQLITE_ROW==sqlite3_step(pRange) ){

  174110.       i64 nSize = 0, dummy;

  174111.       fts3ReadEndBlockField(pRange, 2, &dummy, &nSize);

  174112.       if( nSize<=0 || nSize>nLimit ){

  174113.         /* If nSize==0, then the %_segdir.end_block field does not not 

  174114.         ** contain a size value. This happens if it was written by an

  174115.         ** old version of FTS. In this case it is not possible to determine

  174116.         ** the size of the segment, and so segment promotion does not

  174117.         ** take place.  */

  174118.         bOk = 0;

  174119.         break;

  174120.       }

  174121.       bOk = 1;

  174122.     }

  174123.     rc = sqlite3_reset(pRange);

  174124. 

  174125.     if( bOk ){

  174126.       int iIdx = 0;

  174127.       sqlite3_stmt *pUpdate1 = 0;

  174128.       sqlite3_stmt *pUpdate2 = 0;

  174129. 

  174130.       if( rc==SQLITE_OK ){

  174131.         rc = fts3SqlStmt(p, SQL_UPDATE_LEVEL_IDX, &pUpdate1, 0);

  174132.       }

  174133.       if( rc==SQLITE_OK ){

  174134.         rc = fts3SqlStmt(p, SQL_UPDATE_LEVEL, &pUpdate2, 0);

  174135.       }

  174136. 

  174137.       if( rc==SQLITE_OK ){

  174138. 

  174139.         /* Loop through all %_segdir entries for segments in this index with

  174140.         ** levels equal to or greater than iAbsLevel. As each entry is visited,

  174141.         ** updated it to set (level = -1) and (idx = N), where N is 0 for the

  174142.         ** oldest segment in the range, 1 for the next oldest, and so on.

  174143.         **

  174144.         ** In other words, move all segments being promoted to level -1,

  174145.         ** setting the "idx" fields as appropriate to keep them in the same

  174146.         ** order. The contents of level -1 (which is never used, except

  174147.         ** transiently here), will be moved back to level iAbsLevel below.  */

  174148.         sqlite3_bind_int64(pRange, 1, iAbsLevel);

  174149.         while( SQLITE_ROW==sqlite3_step(pRange) ){

  174150.           sqlite3_bind_int(pUpdate1, 1, iIdx++);

  174151.           sqlite3_bind_int(pUpdate1, 2, sqlite3_column_int(pRange, 0));

  174152.           sqlite3_bind_int(pUpdate1, 3, sqlite3_column_int(pRange, 1));

  174153.           sqlite3_step(pUpdate1);

  174154.           rc = sqlite3_reset(pUpdate1);

  174155.           if( rc!=SQLITE_OK ){

  174156.             sqlite3_reset(pRange);

  174157.             break;

  174158.           }

  174159.         }

  174160.       }

  174161.       if( rc==SQLITE_OK ){

  174162.         rc = sqlite3_reset(pRange);

  174163.       }

  174164. 

  174165.       /* Move level -1 to level iAbsLevel */

  174166.       if( rc==SQLITE_OK ){

  174167.         sqlite3_bind_int64(pUpdate2, 1, iAbsLevel);

  174168.         sqlite3_step(pUpdate2);

  174169.         rc = sqlite3_reset(pUpdate2);

  174170.       }

  174171.     }

  174172.   }

  174173. 

  174174. 

  174175.   return rc;

  174176. }

  174177. 

  174178. /*

  174179. ** Merge all level iLevel segments in the database into a single 

  174180. ** iLevel+1 segment. Or, if iLevel<0, merge all segments into a

  174181. ** single segment with a level equal to the numerically largest level 

  174182. ** currently present in the database.

  174183. **

  174184. ** If this function is called with iLevel<0, but there is only one

  174185. ** segment in the database, SQLITE_DONE is returned immediately. 

  174186. ** Otherwise, if successful, SQLITE_OK is returned. If an error occurs, 

  174187. ** an SQLite error code is returned.

  174188. */

  174189. static int fts3SegmentMerge(

  174190.   Fts3Table *p, 

  174191.   int iLangid,                    /* Language id to merge */

  174192.   int iIndex,                     /* Index in p->aIndex[] to merge */

  174193.   int iLevel                      /* Level to merge */

  174194. ){

  174195.   int rc;                         /* Return code */

  174196.   int iIdx = 0;                   /* Index of new segment */

  174197.   sqlite3_int64 iNewLevel = 0;    /* Level/index to create new segment at */

  174198.   SegmentWriter *pWriter = 0;     /* Used to write the new, merged, segment */

  174199.   Fts3SegFilter filter;           /* Segment term filter condition */

  174200.   Fts3MultiSegReader csr;         /* Cursor to iterate through level(s) */

  174201.   int bIgnoreEmpty = 0;           /* True to ignore empty segments */

  174202.   i64 iMaxLevel = 0;              /* Max level number for this index/langid */

  174203. 

  174204.   assert( iLevel==FTS3_SEGCURSOR_ALL

  174205.        || iLevel==FTS3_SEGCURSOR_PENDING

  174206.        || iLevel>=0

  174207.   );

  174208.   assert( iLevel<FTS3_SEGDIR_MAXLEVEL );

  174209.   assert( iIndex>=0 && iIndex<p->nIndex );

  174210. 

  174211.   rc = sqlite3Fts3SegReaderCursor(p, iLangid, iIndex, iLevel, 0, 0, 1, 0, &csr);

  174212.   if( rc!=SQLITE_OK || csr.nSegment==0 ) goto finished;

  174213. 

  174214.   if( iLevel!=FTS3_SEGCURSOR_PENDING ){

  174215.     rc = fts3SegmentMaxLevel(p, iLangid, iIndex, &iMaxLevel);

  174216.     if( rc!=SQLITE_OK ) goto finished;

  174217.   }

  174218. 

  174219.   if( iLevel==FTS3_SEGCURSOR_ALL ){

  174220.     /* This call is to merge all segments in the database to a single

  174221.     ** segment. The level of the new segment is equal to the numerically

  174222.     ** greatest segment level currently present in the database for this

  174223.     ** index. The idx of the new segment is always 0.  */

  174224.     if( csr.nSegment==1 && 0==fts3SegReaderIsPending(csr.apSegment[0]) ){

  174225.       rc = SQLITE_DONE;

  174226.       goto finished;

  174227.     }

  174228.     iNewLevel = iMaxLevel;

  174229.     bIgnoreEmpty = 1;

  174230. 

  174231.   }else{

  174232.     /* This call is to merge all segments at level iLevel. find the next

  174233.     ** available segment index at level iLevel+1. The call to

  174234.     ** fts3AllocateSegdirIdx() will merge the segments at level iLevel+1 to 

  174235.     ** a single iLevel+2 segment if necessary.  */

  174236.     assert( FTS3_SEGCURSOR_PENDING==-1 );

  174237.     iNewLevel = getAbsoluteLevel(p, iLangid, iIndex, iLevel+1);

  174238.     rc = fts3AllocateSegdirIdx(p, iLangid, iIndex, iLevel+1, &iIdx);

  174239.     bIgnoreEmpty = (iLevel!=FTS3_SEGCURSOR_PENDING) && (iNewLevel>iMaxLevel);

  174240.   }

  174241.   if( rc!=SQLITE_OK ) goto finished;

  174242. 

  174243.   assert( csr.nSegment>0 );

  174244.   assert_fts3_nc( iNewLevel>=getAbsoluteLevel(p, iLangid, iIndex, 0) );

  174245.   assert_fts3_nc( 

  174246.     iNewLevel<getAbsoluteLevel(p, iLangid, iIndex,FTS3_SEGDIR_MAXLEVEL) 

  174247.   );

  174248. 

  174249.   memset(&filter, 0, sizeof(Fts3SegFilter));

  174250.   filter.flags = FTS3_SEGMENT_REQUIRE_POS;

  174251.   filter.flags |= (bIgnoreEmpty ? FTS3_SEGMENT_IGNORE_EMPTY : 0);

  174252. 

  174253.   rc = sqlite3Fts3SegReaderStart(p, &csr, &filter);

  174254.   while( SQLITE_OK==rc ){

  174255.     rc = sqlite3Fts3SegReaderStep(p, &csr);

  174256.     if( rc!=SQLITE_ROW ) break;

  174257.     rc = fts3SegWriterAdd(p, &pWriter, 1, 

  174258.         csr.zTerm, csr.nTerm, csr.aDoclist, csr.nDoclist);

  174259.   }

  174260.   if( rc!=SQLITE_OK ) goto finished;

  174261.   assert( pWriter || bIgnoreEmpty );

  174262. 

  174263.   if( iLevel!=FTS3_SEGCURSOR_PENDING ){

  174264.     rc = fts3DeleteSegdir(

  174265.         p, iLangid, iIndex, iLevel, csr.apSegment, csr.nSegment

  174266.     );

  174267.     if( rc!=SQLITE_OK ) goto finished;

  174268.   }

  174269.   if( pWriter ){

  174270.     rc = fts3SegWriterFlush(p, pWriter, iNewLevel, iIdx);

  174271.     if( rc==SQLITE_OK ){

  174272.       if( iLevel==FTS3_SEGCURSOR_PENDING || iNewLevel<iMaxLevel ){

  174273.         rc = fts3PromoteSegments(p, iNewLevel, pWriter->nLeafData);

  174274.       }

  174275.     }

  174276.   }

  174277. 

  174278.  finished:

  174279.   fts3SegWriterFree(pWriter);

  174280.   sqlite3Fts3SegReaderFinish(&csr);

  174281.   return rc;

  174282. }

  174283. 

  174284. 

  174285. /* 

  174286. ** Flush the contents of pendingTerms to level 0 segments. 

  174287. */

  174288. SQLITE_PRIVATE int sqlite3Fts3PendingTermsFlush(Fts3Table *p){

  174289.   int rc = SQLITE_OK;

  174290.   int i;

  174291.         

  174292.   for(i=0; rc==SQLITE_OK && i<p->nIndex; i++){

  174293.     rc = fts3SegmentMerge(p, p->iPrevLangid, i, FTS3_SEGCURSOR_PENDING);

  174294.     if( rc==SQLITE_DONE ) rc = SQLITE_OK;

  174295.   }

  174296.   sqlite3Fts3PendingTermsClear(p);

  174297. 

  174298.   /* Determine the auto-incr-merge setting if unknown.  If enabled,

  174299.   ** estimate the number of leaf blocks of content to be written

  174300.   */

  174301.   if( rc==SQLITE_OK && p->bHasStat

  174302.    && p->nAutoincrmerge==0xff && p->nLeafAdd>0

  174303.   ){

  174304.     sqlite3_stmt *pStmt = 0;

  174305.     rc = fts3SqlStmt(p, SQL_SELECT_STAT, &pStmt, 0);

  174306.     if( rc==SQLITE_OK ){

  174307.       sqlite3_bind_int(pStmt, 1, FTS_STAT_AUTOINCRMERGE);

  174308.       rc = sqlite3_step(pStmt);

  174309.       if( rc==SQLITE_ROW ){

  174310.         p->nAutoincrmerge = sqlite3_column_int(pStmt, 0);

  174311.         if( p->nAutoincrmerge==1 ) p->nAutoincrmerge = 8;

  174312.       }else if( rc==SQLITE_DONE ){

  174313.         p->nAutoincrmerge = 0;

  174314.       }

  174315.       rc = sqlite3_reset(pStmt);

  174316.     }

  174317.   }

  174318.   return rc;

  174319. }

  174320. 

  174321. /*

  174322. ** Encode N integers as varints into a blob.

  174323. */

  174324. static void fts3EncodeIntArray(

  174325.   int N,             /* The number of integers to encode */

  174326.   u32 *a,            /* The integer values */

  174327.   char *zBuf,        /* Write the BLOB here */

  174328.   int *pNBuf         /* Write number of bytes if zBuf[] used here */

  174329. ){

  174330.   int i, j;

  174331.   for(i=j=0; i<N; i++){

  174332.     j += sqlite3Fts3PutVarint(&zBuf[j], (sqlite3_int64)a[i]);

  174333.   }

  174334.   *pNBuf = j;

  174335. }

  174336. 

  174337. /*

  174338. ** Decode a blob of varints into N integers

  174339. */

  174340. static void fts3DecodeIntArray(

  174341.   int N,             /* The number of integers to decode */

  174342.   u32 *a,            /* Write the integer values */

  174343.   const char *zBuf,  /* The BLOB containing the varints */

  174344.   int nBuf           /* size of the BLOB */

  174345. ){

  174346.   int i = 0;

  174347.   if( nBuf && (zBuf[nBuf-1]&0x80)==0 ){

  174348.     int j;

  174349.     for(i=j=0; i<N && j<nBuf; i++){

  174350.       sqlite3_int64 x;

  174351.       j += sqlite3Fts3GetVarint(&zBuf[j], &x);

  174352.       a[i] = (u32)(x & 0xffffffff);

  174353.     }

  174354.   }

  174355.   while( i<N ) a[i++] = 0;

  174356. }

  174357. 

  174358. /*

  174359. ** Insert the sizes (in tokens) for each column of the document

  174360. ** with docid equal to p->iPrevDocid.  The sizes are encoded as

  174361. ** a blob of varints.

  174362. */

  174363. static void fts3InsertDocsize(

  174364.   int *pRC,                       /* Result code */

  174365.   Fts3Table *p,                   /* Table into which to insert */

  174366.   u32 *aSz                        /* Sizes of each column, in tokens */

  174367. ){

  174368.   char *pBlob;             /* The BLOB encoding of the document size */

  174369.   int nBlob;               /* Number of bytes in the BLOB */

  174370.   sqlite3_stmt *pStmt;     /* Statement used to insert the encoding */

  174371.   int rc;                  /* Result code from subfunctions */

  174372. 

  174373.   if( *pRC ) return;

  174374.   pBlob = sqlite3_malloc64( 10*(sqlite3_int64)p->nColumn );

  174375.   if( pBlob==0 ){

  174376.     *pRC = SQLITE_NOMEM;

  174377.     return;

  174378.   }

  174379.   fts3EncodeIntArray(p->nColumn, aSz, pBlob, &nBlob);

  174380.   rc = fts3SqlStmt(p, SQL_REPLACE_DOCSIZE, &pStmt, 0);

  174381.   if( rc ){

  174382.     sqlite3_free(pBlob);

  174383.     *pRC = rc;

  174384.     return;

  174385.   }

  174386.   sqlite3_bind_int64(pStmt, 1, p->iPrevDocid);

  174387.   sqlite3_bind_blob(pStmt, 2, pBlob, nBlob, sqlite3_free);

  174388.   sqlite3_step(pStmt);

  174389.   *pRC = sqlite3_reset(pStmt);

  174390. }

  174391. 

  174392. /*

  174393. ** Record 0 of the %_stat table contains a blob consisting of N varints,

  174394. ** where N is the number of user defined columns in the fts3 table plus

  174395. ** two. If nCol is the number of user defined columns, then values of the 

  174396. ** varints are set as follows:

  174397. **

  174398. **   Varint 0:       Total number of rows in the table.

  174399. **

  174400. **   Varint 1..nCol: For each column, the total number of tokens stored in

  174401. **                   the column for all rows of the table.

  174402. **

  174403. **   Varint 1+nCol:  The total size, in bytes, of all text values in all

  174404. **                   columns of all rows of the table.

  174405. **

  174406. */

  174407. static void fts3UpdateDocTotals(

  174408.   int *pRC,                       /* The result code */

  174409.   Fts3Table *p,                   /* Table being updated */

  174410.   u32 *aSzIns,                    /* Size increases */

  174411.   u32 *aSzDel,                    /* Size decreases */

  174412.   int nChng                       /* Change in the number of documents */

  174413. ){

  174414.   char *pBlob;             /* Storage for BLOB written into %_stat */

  174415.   int nBlob;               /* Size of BLOB written into %_stat */

  174416.   u32 *a;                  /* Array of integers that becomes the BLOB */

  174417.   sqlite3_stmt *pStmt;     /* Statement for reading and writing */

  174418.   int i;                   /* Loop counter */

  174419.   int rc;                  /* Result code from subfunctions */

  174420. 

  174421.   const int nStat = p->nColumn+2;

  174422. 

  174423.   if( *pRC ) return;

  174424.   a = sqlite3_malloc64( (sizeof(u32)+10)*(sqlite3_int64)nStat );

  174425.   if( a==0 ){

  174426.     *pRC = SQLITE_NOMEM;

  174427.     return;

  174428.   }

  174429.   pBlob = (char*)&a[nStat];

  174430.   rc = fts3SqlStmt(p, SQL_SELECT_STAT, &pStmt, 0);

  174431.   if( rc ){

  174432.     sqlite3_free(a);

  174433.     *pRC = rc;

  174434.     return;

  174435.   }

  174436.   sqlite3_bind_int(pStmt, 1, FTS_STAT_DOCTOTAL);

  174437.   if( sqlite3_step(pStmt)==SQLITE_ROW ){

  174438.     fts3DecodeIntArray(nStat, a,

  174439.          sqlite3_column_blob(pStmt, 0),

  174440.          sqlite3_column_bytes(pStmt, 0));

  174441.   }else{

  174442.     memset(a, 0, sizeof(u32)*(nStat) );

  174443.   }

  174444.   rc = sqlite3_reset(pStmt);

  174445.   if( rc!=SQLITE_OK ){

  174446.     sqlite3_free(a);

  174447.     *pRC = rc;

  174448.     return;

  174449.   }

  174450.   if( nChng<0 && a[0]<(u32)(-nChng) ){

  174451.     a[0] = 0;

  174452.   }else{

  174453.     a[0] += nChng;

  174454.   }

  174455.   for(i=0; i<p->nColumn+1; i++){

  174456.     u32 x = a[i+1];

  174457.     if( x+aSzIns[i] < aSzDel[i] ){

  174458.       x = 0;

  174459.     }else{

  174460.       x = x + aSzIns[i] - aSzDel[i];

  174461.     }

  174462.     a[i+1] = x;

  174463.   }

  174464.   fts3EncodeIntArray(nStat, a, pBlob, &nBlob);

  174465.   rc = fts3SqlStmt(p, SQL_REPLACE_STAT, &pStmt, 0);

  174466.   if( rc ){

  174467.     sqlite3_free(a);

  174468.     *pRC = rc;

  174469.     return;

  174470.   }

  174471.   sqlite3_bind_int(pStmt, 1, FTS_STAT_DOCTOTAL);

  174472.   sqlite3_bind_blob(pStmt, 2, pBlob, nBlob, SQLITE_STATIC);

  174473.   sqlite3_step(pStmt);

  174474.   *pRC = sqlite3_reset(pStmt);

  174475.   sqlite3_bind_null(pStmt, 2);

  174476.   sqlite3_free(a);

  174477. }

  174478. 

  174479. /*

  174480. ** Merge the entire database so that there is one segment for each 

  174481. ** iIndex/iLangid combination.

  174482. */

  174483. static int fts3DoOptimize(Fts3Table *p, int bReturnDone){

  174484.   int bSeenDone = 0;

  174485.   int rc;

  174486.   sqlite3_stmt *pAllLangid = 0;

  174487. 

  174488.   rc = fts3SqlStmt(p, SQL_SELECT_ALL_LANGID, &pAllLangid, 0);

  174489.   if( rc==SQLITE_OK ){

  174490.     int rc2;

  174491.     sqlite3_bind_int(pAllLangid, 1, p->iPrevLangid);

  174492.     sqlite3_bind_int(pAllLangid, 2, p->nIndex);

  174493.     while( sqlite3_step(pAllLangid)==SQLITE_ROW ){

  174494.       int i;

  174495.       int iLangid = sqlite3_column_int(pAllLangid, 0);

  174496.       for(i=0; rc==SQLITE_OK && i<p->nIndex; i++){

  174497.         rc = fts3SegmentMerge(p, iLangid, i, FTS3_SEGCURSOR_ALL);

  174498.         if( rc==SQLITE_DONE ){

  174499.           bSeenDone = 1;

  174500.           rc = SQLITE_OK;

  174501.         }

  174502.       }

  174503.     }

  174504.     rc2 = sqlite3_reset(pAllLangid);

  174505.     if( rc==SQLITE_OK ) rc = rc2;

  174506.   }

  174507. 

  174508.   sqlite3Fts3SegmentsClose(p);

  174509.   sqlite3Fts3PendingTermsClear(p);

  174510. 

  174511.   return (rc==SQLITE_OK && bReturnDone && bSeenDone) ? SQLITE_DONE : rc;

  174512. }

  174513. 

  174514. /*

  174515. ** This function is called when the user executes the following statement:

  174516. **

  174517. **     INSERT INTO <tbl>(<tbl>) VALUES('rebuild');

  174518. **

  174519. ** The entire FTS index is discarded and rebuilt. If the table is one 

  174520. ** created using the content=xxx option, then the new index is based on

  174521. ** the current contents of the xxx table. Otherwise, it is rebuilt based

  174522. ** on the contents of the %_content table.

  174523. */

  174524. static int fts3DoRebuild(Fts3Table *p){

  174525.   int rc;                         /* Return Code */

  174526. 

  174527.   rc = fts3DeleteAll(p, 0);

  174528.   if( rc==SQLITE_OK ){

  174529.     u32 *aSz = 0;

  174530.     u32 *aSzIns = 0;

  174531.     u32 *aSzDel = 0;

  174532.     sqlite3_stmt *pStmt = 0;

  174533.     int nEntry = 0;

  174534. 

  174535.     /* Compose and prepare an SQL statement to loop through the content table */

  174536.     char *zSql = sqlite3_mprintf("SELECT %s" , p->zReadExprlist);

  174537.     if( !zSql ){

  174538.       rc = SQLITE_NOMEM;

  174539.     }else{

  174540.       rc = sqlite3_prepare_v2(p->db, zSql, -1, &pStmt, 0);

  174541.       sqlite3_free(zSql);

  174542.     }

  174543. 

  174544.     if( rc==SQLITE_OK ){

  174545.       sqlite3_int64 nByte = sizeof(u32) * ((sqlite3_int64)p->nColumn+1)*3;

  174546.       aSz = (u32 *)sqlite3_malloc64(nByte);

  174547.       if( aSz==0 ){

  174548.         rc = SQLITE_NOMEM;

  174549.       }else{

  174550.         memset(aSz, 0, nByte);

  174551.         aSzIns = &aSz[p->nColumn+1];

  174552.         aSzDel = &aSzIns[p->nColumn+1];

  174553.       }

  174554.     }

  174555. 

  174556.     while( rc==SQLITE_OK && SQLITE_ROW==sqlite3_step(pStmt) ){

  174557.       int iCol;

  174558.       int iLangid = langidFromSelect(p, pStmt);

  174559.       rc = fts3PendingTermsDocid(p, 0, iLangid, sqlite3_column_int64(pStmt, 0));

  174560.       memset(aSz, 0, sizeof(aSz[0]) * (p->nColumn+1));

  174561.       for(iCol=0; rc==SQLITE_OK && iCol<p->nColumn; iCol++){

  174562.         if( p->abNotindexed[iCol]==0 ){

  174563.           const char *z = (const char *) sqlite3_column_text(pStmt, iCol+1);

  174564.           rc = fts3PendingTermsAdd(p, iLangid, z, iCol, &aSz[iCol]);

  174565.           aSz[p->nColumn] += sqlite3_column_bytes(pStmt, iCol+1);

  174566.         }

  174567.       }

  174568.       if( p->bHasDocsize ){

  174569.         fts3InsertDocsize(&rc, p, aSz);

  174570.       }

  174571.       if( rc!=SQLITE_OK ){

  174572.         sqlite3_finalize(pStmt);

  174573.         pStmt = 0;

  174574.       }else{

  174575.         nEntry++;

  174576.         for(iCol=0; iCol<=p->nColumn; iCol++){

  174577.           aSzIns[iCol] += aSz[iCol];

  174578.         }

  174579.       }

  174580.     }

  174581.     if( p->bFts4 ){

  174582.       fts3UpdateDocTotals(&rc, p, aSzIns, aSzDel, nEntry);

  174583.     }

  174584.     sqlite3_free(aSz);

  174585. 

  174586.     if( pStmt ){

  174587.       int rc2 = sqlite3_finalize(pStmt);

  174588.       if( rc==SQLITE_OK ){

  174589.         rc = rc2;

  174590.       }

  174591.     }

  174592.   }

  174593. 

  174594.   return rc;

  174595. }

  174596. 

  174597. 

  174598. /*

  174599. ** This function opens a cursor used to read the input data for an 

  174600. ** incremental merge operation. Specifically, it opens a cursor to scan

  174601. ** the oldest nSeg segments (idx=0 through idx=(nSeg-1)) in absolute 

  174602. ** level iAbsLevel.

  174603. */

  174604. static int fts3IncrmergeCsr(

  174605.   Fts3Table *p,                   /* FTS3 table handle */

  174606.   sqlite3_int64 iAbsLevel,        /* Absolute level to open */

  174607.   int nSeg,                       /* Number of segments to merge */

  174608.   Fts3MultiSegReader *pCsr        /* Cursor object to populate */

  174609. ){

  174610.   int rc;                         /* Return Code */

  174611.   sqlite3_stmt *pStmt = 0;        /* Statement used to read %_segdir entry */  

  174612.   sqlite3_int64 nByte;            /* Bytes allocated at pCsr->apSegment[] */

  174613. 

  174614.   /* Allocate space for the Fts3MultiSegReader.aCsr[] array */

  174615.   memset(pCsr, 0, sizeof(*pCsr));

  174616.   nByte = sizeof(Fts3SegReader *) * nSeg;

  174617.   pCsr->apSegment = (Fts3SegReader **)sqlite3_malloc64(nByte);

  174618. 

  174619.   if( pCsr->apSegment==0 ){

  174620.     rc = SQLITE_NOMEM;

  174621.   }else{

  174622.     memset(pCsr->apSegment, 0, nByte);

  174623.     rc = fts3SqlStmt(p, SQL_SELECT_LEVEL, &pStmt, 0);

  174624.   }

  174625.   if( rc==SQLITE_OK ){

  174626.     int i;

  174627.     int rc2;

  174628.     sqlite3_bind_int64(pStmt, 1, iAbsLevel);

  174629.     assert( pCsr->nSegment==0 );

  174630.     for(i=0; rc==SQLITE_OK && sqlite3_step(pStmt)==SQLITE_ROW && i<nSeg; i++){

  174631.       rc = sqlite3Fts3SegReaderNew(i, 0,

  174632.           sqlite3_column_int64(pStmt, 1),        /* segdir.start_block */

  174633.           sqlite3_column_int64(pStmt, 2),        /* segdir.leaves_end_block */

  174634.           sqlite3_column_int64(pStmt, 3),        /* segdir.end_block */

  174635.           sqlite3_column_blob(pStmt, 4),         /* segdir.root */

  174636.           sqlite3_column_bytes(pStmt, 4),        /* segdir.root */

  174637.           &pCsr->apSegment[i]

  174638.       );

  174639.       pCsr->nSegment++;

  174640.     }

  174641.     rc2 = sqlite3_reset(pStmt);

  174642.     if( rc==SQLITE_OK ) rc = rc2;

  174643.   }

  174644. 

  174645.   return rc;

  174646. }

  174647. 

  174648. typedef struct IncrmergeWriter IncrmergeWriter;

  174649. typedef struct NodeWriter NodeWriter;

  174650. typedef struct Blob Blob;

  174651. typedef struct NodeReader NodeReader;

  174652. 

  174653. /*

  174654. ** An instance of the following structure is used as a dynamic buffer

  174655. ** to build up nodes or other blobs of data in.

  174656. **

  174657. ** The function blobGrowBuffer() is used to extend the allocation.

  174658. */

  174659. struct Blob {

  174660.   char *a;                        /* Pointer to allocation */

  174661.   int n;                          /* Number of valid bytes of data in a[] */

  174662.   int nAlloc;                     /* Allocated size of a[] (nAlloc>=n) */

  174663. };

  174664. 

  174665. /*

  174666. ** This structure is used to build up buffers containing segment b-tree 

  174667. ** nodes (blocks).

  174668. */

  174669. struct NodeWriter {

  174670.   sqlite3_int64 iBlock;           /* Current block id */

  174671.   Blob key;                       /* Last key written to the current block */

  174672.   Blob block;                     /* Current block image */

  174673. };

  174674. 

  174675. /*

  174676. ** An object of this type contains the state required to create or append

  174677. ** to an appendable b-tree segment.

  174678. */

  174679. struct IncrmergeWriter {

  174680.   int nLeafEst;                   /* Space allocated for leaf blocks */

  174681.   int nWork;                      /* Number of leaf pages flushed */

  174682.   sqlite3_int64 iAbsLevel;        /* Absolute level of input segments */

  174683.   int iIdx;                       /* Index of *output* segment in iAbsLevel+1 */

  174684.   sqlite3_int64 iStart;           /* Block number of first allocated block */

  174685.   sqlite3_int64 iEnd;             /* Block number of last allocated block */

  174686.   sqlite3_int64 nLeafData;        /* Bytes of leaf page data so far */

  174687.   u8 bNoLeafData;                 /* If true, store 0 for segment size */

  174688.   NodeWriter aNodeWriter[FTS_MAX_APPENDABLE_HEIGHT];

  174689. };

  174690. 

  174691. /*

  174692. ** An object of the following type is used to read data from a single

  174693. ** FTS segment node. See the following functions:

  174694. **

  174695. **     nodeReaderInit()

  174696. **     nodeReaderNext()

  174697. **     nodeReaderRelease()

  174698. */

  174699. struct NodeReader {

  174700.   const char *aNode;

  174701.   int nNode;

  174702.   int iOff;                       /* Current offset within aNode[] */

  174703. 

  174704.   /* Output variables. Containing the current node entry. */

  174705.   sqlite3_int64 iChild;           /* Pointer to child node */

  174706.   Blob term;                      /* Current term */

  174707.   const char *aDoclist;           /* Pointer to doclist */

  174708.   int nDoclist;                   /* Size of doclist in bytes */

  174709. };

  174710. 

  174711. /*

  174712. ** If *pRc is not SQLITE_OK when this function is called, it is a no-op.

  174713. ** Otherwise, if the allocation at pBlob->a is not already at least nMin

  174714. ** bytes in size, extend (realloc) it to be so.

  174715. **

  174716. ** If an OOM error occurs, set *pRc to SQLITE_NOMEM and leave pBlob->a

  174717. ** unmodified. Otherwise, if the allocation succeeds, update pBlob->nAlloc

  174718. ** to reflect the new size of the pBlob->a[] buffer.

  174719. */

  174720. static void blobGrowBuffer(Blob *pBlob, int nMin, int *pRc){

  174721.   if( *pRc==SQLITE_OK && nMin>pBlob->nAlloc ){

  174722.     int nAlloc = nMin;

  174723.     char *a = (char *)sqlite3_realloc(pBlob->a, nAlloc);

  174724.     if( a ){

  174725.       pBlob->nAlloc = nAlloc;

  174726.       pBlob->a = a;

  174727.     }else{

  174728.       *pRc = SQLITE_NOMEM;

  174729.     }

  174730.   }

  174731. }

  174732. 

  174733. /*

  174734. ** Attempt to advance the node-reader object passed as the first argument to

  174735. ** the next entry on the node. 

  174736. **

  174737. ** Return an error code if an error occurs (SQLITE_NOMEM is possible). 

  174738. ** Otherwise return SQLITE_OK. If there is no next entry on the node

  174739. ** (e.g. because the current entry is the last) set NodeReader->aNode to

  174740. ** NULL to indicate EOF. Otherwise, populate the NodeReader structure output 

  174741. ** variables for the new entry.

  174742. */

  174743. static int nodeReaderNext(NodeReader *p){

  174744.   int bFirst = (p->term.n==0);    /* True for first term on the node */

  174745.   int nPrefix = 0;                /* Bytes to copy from previous term */

  174746.   int nSuffix = 0;                /* Bytes to append to the prefix */

  174747.   int rc = SQLITE_OK;             /* Return code */

  174748. 

  174749.   assert( p->aNode );

  174750.   if( p->iChild && bFirst==0 ) p->iChild++;

  174751.   if( p->iOff>=p->nNode ){

  174752.     /* EOF */

  174753.     p->aNode = 0;

  174754.   }else{

  174755.     if( bFirst==0 ){

  174756.       p->iOff += fts3GetVarint32(&p->aNode[p->iOff], &nPrefix);

  174757.     }

  174758.     p->iOff += fts3GetVarint32(&p->aNode[p->iOff], &nSuffix);

  174759. 

  174760.     if( nPrefix>p->term.n || nSuffix>p->nNode-p->iOff || nSuffix==0 ){

  174761.       return FTS_CORRUPT_VTAB;

  174762.     }

  174763.     blobGrowBuffer(&p->term, nPrefix+nSuffix, &rc);

  174764.     if( rc==SQLITE_OK ){

  174765.       memcpy(&p->term.a[nPrefix], &p->aNode[p->iOff], nSuffix);

  174766.       p->term.n = nPrefix+nSuffix;

  174767.       p->iOff += nSuffix;

  174768.       if( p->iChild==0 ){

  174769.         p->iOff += fts3GetVarint32(&p->aNode[p->iOff], &p->nDoclist);

  174770.         if( (p->nNode-p->iOff)<p->nDoclist ){

  174771.           return FTS_CORRUPT_VTAB;

  174772.         }

  174773.         p->aDoclist = &p->aNode[p->iOff];

  174774.         p->iOff += p->nDoclist;

  174775.       }

  174776.     }

  174777.   }

  174778. 

  174779.   assert_fts3_nc( p->iOff<=p->nNode );

  174780.   return rc;

  174781. }

  174782. 

  174783. /*

  174784. ** Release all dynamic resources held by node-reader object *p.

  174785. */

  174786. static void nodeReaderRelease(NodeReader *p){

  174787.   sqlite3_free(p->term.a);

  174788. }

  174789. 

  174790. /*

  174791. ** Initialize a node-reader object to read the node in buffer aNode/nNode.

  174792. **

  174793. ** If successful, SQLITE_OK is returned and the NodeReader object set to 

  174794. ** point to the first entry on the node (if any). Otherwise, an SQLite

  174795. ** error code is returned.

  174796. */

  174797. static int nodeReaderInit(NodeReader *p, const char *aNode, int nNode){

  174798.   memset(p, 0, sizeof(NodeReader));

  174799.   p->aNode = aNode;

  174800.   p->nNode = nNode;

  174801. 

  174802.   /* Figure out if this is a leaf or an internal node. */

  174803.   if( p->aNode[0] ){

  174804.     /* An internal node. */

  174805.     p->iOff = 1 + sqlite3Fts3GetVarint(&p->aNode[1], &p->iChild);

  174806.   }else{

  174807.     p->iOff = 1;

  174808.   }

  174809. 

  174810.   return nodeReaderNext(p);

  174811. }

  174812. 

  174813. /*

  174814. ** This function is called while writing an FTS segment each time a leaf o

  174815. ** node is finished and written to disk. The key (zTerm/nTerm) is guaranteed

  174816. ** to be greater than the largest key on the node just written, but smaller

  174817. ** than or equal to the first key that will be written to the next leaf

  174818. ** node.

  174819. **

  174820. ** The block id of the leaf node just written to disk may be found in

  174821. ** (pWriter->aNodeWriter[0].iBlock) when this function is called.

  174822. */

  174823. static int fts3IncrmergePush(

  174824.   Fts3Table *p,                   /* Fts3 table handle */

  174825.   IncrmergeWriter *pWriter,       /* Writer object */

  174826.   const char *zTerm,              /* Term to write to internal node */

  174827.   int nTerm                       /* Bytes at zTerm */

  174828. ){

  174829.   sqlite3_int64 iPtr = pWriter->aNodeWriter[0].iBlock;

  174830.   int iLayer;

  174831. 

  174832.   assert( nTerm>0 );

  174833.   for(iLayer=1; ALWAYS(iLayer<FTS_MAX_APPENDABLE_HEIGHT); iLayer++){

  174834.     sqlite3_int64 iNextPtr = 0;

  174835.     NodeWriter *pNode = &pWriter->aNodeWriter[iLayer];

  174836.     int rc = SQLITE_OK;

  174837.     int nPrefix;

  174838.     int nSuffix;

  174839.     int nSpace;

  174840. 

  174841.     /* Figure out how much space the key will consume if it is written to

  174842.     ** the current node of layer iLayer. Due to the prefix compression, 

  174843.     ** the space required changes depending on which node the key is to

  174844.     ** be added to.  */

  174845.     nPrefix = fts3PrefixCompress(pNode->key.a, pNode->key.n, zTerm, nTerm);

  174846.     nSuffix = nTerm - nPrefix;

  174847.     nSpace  = sqlite3Fts3VarintLen(nPrefix);

  174848.     nSpace += sqlite3Fts3VarintLen(nSuffix) + nSuffix;

  174849. 

  174850.     if( pNode->key.n==0 || (pNode->block.n + nSpace)<=p->nNodeSize ){ 

  174851.       /* If the current node of layer iLayer contains zero keys, or if adding

  174852.       ** the key to it will not cause it to grow to larger than nNodeSize 

  174853.       ** bytes in size, write the key here.  */

  174854. 

  174855.       Blob *pBlk = &pNode->block;

  174856.       if( pBlk->n==0 ){

  174857.         blobGrowBuffer(pBlk, p->nNodeSize, &rc);

  174858.         if( rc==SQLITE_OK ){

  174859.           pBlk->a[0] = (char)iLayer;

  174860.           pBlk->n = 1 + sqlite3Fts3PutVarint(&pBlk->a[1], iPtr);

  174861.         }

  174862.       }

  174863.       blobGrowBuffer(pBlk, pBlk->n + nSpace, &rc);

  174864.       blobGrowBuffer(&pNode->key, nTerm, &rc);

  174865. 

  174866.       if( rc==SQLITE_OK ){

  174867.         if( pNode->key.n ){

  174868.           pBlk->n += sqlite3Fts3PutVarint(&pBlk->a[pBlk->n], nPrefix);

  174869.         }

  174870.         pBlk->n += sqlite3Fts3PutVarint(&pBlk->a[pBlk->n], nSuffix);

  174871.         memcpy(&pBlk->a[pBlk->n], &zTerm[nPrefix], nSuffix);

  174872.         pBlk->n += nSuffix;

  174873. 

  174874.         memcpy(pNode->key.a, zTerm, nTerm);

  174875.         pNode->key.n = nTerm;

  174876.       }

  174877.     }else{

  174878.       /* Otherwise, flush the current node of layer iLayer to disk.

  174879.       ** Then allocate a new, empty sibling node. The key will be written

  174880.       ** into the parent of this node. */

  174881.       rc = fts3WriteSegment(p, pNode->iBlock, pNode->block.a, pNode->block.n);

  174882. 

  174883.       assert( pNode->block.nAlloc>=p->nNodeSize );

  174884.       pNode->block.a[0] = (char)iLayer;

  174885.       pNode->block.n = 1 + sqlite3Fts3PutVarint(&pNode->block.a[1], iPtr+1);

  174886. 

  174887.       iNextPtr = pNode->iBlock;

  174888.       pNode->iBlock++;

  174889.       pNode->key.n = 0;

  174890.     }

  174891. 

  174892.     if( rc!=SQLITE_OK || iNextPtr==0 ) return rc;

  174893.     iPtr = iNextPtr;

  174894.   }

  174895. 

  174896.   assert( 0 );

  174897.   return 0;

  174898. }

  174899. 

  174900. /*

  174901. ** Append a term and (optionally) doclist to the FTS segment node currently

  174902. ** stored in blob *pNode. The node need not contain any terms, but the

  174903. ** header must be written before this function is called.

  174904. **

  174905. ** A node header is a single 0x00 byte for a leaf node, or a height varint

  174906. ** followed by the left-hand-child varint for an internal node.

  174907. **

  174908. ** The term to be appended is passed via arguments zTerm/nTerm. For a 

  174909. ** leaf node, the doclist is passed as aDoclist/nDoclist. For an internal

  174910. ** node, both aDoclist and nDoclist must be passed 0.

  174911. **

  174912. ** If the size of the value in blob pPrev is zero, then this is the first

  174913. ** term written to the node. Otherwise, pPrev contains a copy of the 

  174914. ** previous term. Before this function returns, it is updated to contain a

  174915. ** copy of zTerm/nTerm.

  174916. **

  174917. ** It is assumed that the buffer associated with pNode is already large

  174918. ** enough to accommodate the new entry. The buffer associated with pPrev

  174919. ** is extended by this function if requrired.

  174920. **

  174921. ** If an error (i.e. OOM condition) occurs, an SQLite error code is

  174922. ** returned. Otherwise, SQLITE_OK.

  174923. */

  174924. static int fts3AppendToNode(

  174925.   Blob *pNode,                    /* Current node image to append to */

  174926.   Blob *pPrev,                    /* Buffer containing previous term written */

  174927.   const char *zTerm,              /* New term to write */

  174928.   int nTerm,                      /* Size of zTerm in bytes */

  174929.   const char *aDoclist,           /* Doclist (or NULL) to write */

  174930.   int nDoclist                    /* Size of aDoclist in bytes */ 

  174931. ){

  174932.   int rc = SQLITE_OK;             /* Return code */

  174933.   int bFirst = (pPrev->n==0);     /* True if this is the first term written */

  174934.   int nPrefix;                    /* Size of term prefix in bytes */

  174935.   int nSuffix;                    /* Size of term suffix in bytes */

  174936. 

  174937.   /* Node must have already been started. There must be a doclist for a

  174938.   ** leaf node, and there must not be a doclist for an internal node.  */

  174939.   assert( pNode->n>0 );

  174940.   assert_fts3_nc( (pNode->a[0]=='\0')==(aDoclist!=0) );

  174941. 

  174942.   blobGrowBuffer(pPrev, nTerm, &rc);

  174943.   if( rc!=SQLITE_OK ) return rc;

  174944. 

  174945.   nPrefix = fts3PrefixCompress(pPrev->a, pPrev->n, zTerm, nTerm);

  174946.   nSuffix = nTerm - nPrefix;

  174947.   memcpy(pPrev->a, zTerm, nTerm);

  174948.   pPrev->n = nTerm;

  174949. 

  174950.   if( bFirst==0 ){

  174951.     pNode->n += sqlite3Fts3PutVarint(&pNode->a[pNode->n], nPrefix);

  174952.   }

  174953.   pNode->n += sqlite3Fts3PutVarint(&pNode->a[pNode->n], nSuffix);

  174954.   memcpy(&pNode->a[pNode->n], &zTerm[nPrefix], nSuffix);

  174955.   pNode->n += nSuffix;

  174956. 

  174957.   if( aDoclist ){

  174958.     pNode->n += sqlite3Fts3PutVarint(&pNode->a[pNode->n], nDoclist);

  174959.     memcpy(&pNode->a[pNode->n], aDoclist, nDoclist);

  174960.     pNode->n += nDoclist;

  174961.   }

  174962. 

  174963.   assert( pNode->n<=pNode->nAlloc );

  174964. 

  174965.   return SQLITE_OK;

  174966. }

  174967. 

  174968. /*

  174969. ** Append the current term and doclist pointed to by cursor pCsr to the

  174970. ** appendable b-tree segment opened for writing by pWriter.

  174971. **

  174972. ** Return SQLITE_OK if successful, or an SQLite error code otherwise.

  174973. */

  174974. static int fts3IncrmergeAppend(

  174975.   Fts3Table *p,                   /* Fts3 table handle */

  174976.   IncrmergeWriter *pWriter,       /* Writer object */

  174977.   Fts3MultiSegReader *pCsr        /* Cursor containing term and doclist */

  174978. ){

  174979.   const char *zTerm = pCsr->zTerm;

  174980.   int nTerm = pCsr->nTerm;

  174981.   const char *aDoclist = pCsr->aDoclist;

  174982.   int nDoclist = pCsr->nDoclist;

  174983.   int rc = SQLITE_OK;           /* Return code */

  174984.   int nSpace;                   /* Total space in bytes required on leaf */

  174985.   int nPrefix;                  /* Size of prefix shared with previous term */

  174986.   int nSuffix;                  /* Size of suffix (nTerm - nPrefix) */

  174987.   NodeWriter *pLeaf;            /* Object used to write leaf nodes */

  174988. 

  174989.   pLeaf = &pWriter->aNodeWriter[0];

  174990.   nPrefix = fts3PrefixCompress(pLeaf->key.a, pLeaf->key.n, zTerm, nTerm);

  174991.   nSuffix = nTerm - nPrefix;

  174992. 

  174993.   nSpace  = sqlite3Fts3VarintLen(nPrefix);

  174994.   nSpace += sqlite3Fts3VarintLen(nSuffix) + nSuffix;

  174995.   nSpace += sqlite3Fts3VarintLen(nDoclist) + nDoclist;

  174996. 

  174997.   /* If the current block is not empty, and if adding this term/doclist

  174998.   ** to the current block would make it larger than Fts3Table.nNodeSize

  174999.   ** bytes, write this block out to the database. */

  175000.   if( pLeaf->block.n>0 && (pLeaf->block.n + nSpace)>p->nNodeSize ){

  175001.     rc = fts3WriteSegment(p, pLeaf->iBlock, pLeaf->block.a, pLeaf->block.n);

  175002.     pWriter->nWork++;

  175003. 

  175004.     /* Add the current term to the parent node. The term added to the 

  175005.     ** parent must:

  175006.     **

  175007.     **   a) be greater than the largest term on the leaf node just written

  175008.     **      to the database (still available in pLeaf->key), and

  175009.     **

  175010.     **   b) be less than or equal to the term about to be added to the new

  175011.     **      leaf node (zTerm/nTerm).

  175012.     **

  175013.     ** In other words, it must be the prefix of zTerm 1 byte longer than

  175014.     ** the common prefix (if any) of zTerm and pWriter->zTerm.

  175015.     */

  175016.     if( rc==SQLITE_OK ){

  175017.       rc = fts3IncrmergePush(p, pWriter, zTerm, nPrefix+1);

  175018.     }

  175019. 

  175020.     /* Advance to the next output block */

  175021.     pLeaf->iBlock++;

  175022.     pLeaf->key.n = 0;

  175023.     pLeaf->block.n = 0;

  175024. 

  175025.     nSuffix = nTerm;

  175026.     nSpace  = 1;

  175027.     nSpace += sqlite3Fts3VarintLen(nSuffix) + nSuffix;

  175028.     nSpace += sqlite3Fts3VarintLen(nDoclist) + nDoclist;

  175029.   }

  175030. 

  175031.   pWriter->nLeafData += nSpace;

  175032.   blobGrowBuffer(&pLeaf->block, pLeaf->block.n + nSpace, &rc);

  175033.   if( rc==SQLITE_OK ){

  175034.     if( pLeaf->block.n==0 ){

  175035.       pLeaf->block.n = 1;

  175036.       pLeaf->block.a[0] = '\0';

  175037.     }

  175038.     rc = fts3AppendToNode(

  175039.         &pLeaf->block, &pLeaf->key, zTerm, nTerm, aDoclist, nDoclist

  175040.     );

  175041.   }

  175042. 

  175043.   return rc;

  175044. }

  175045. 

  175046. /*

  175047. ** This function is called to release all dynamic resources held by the

  175048. ** merge-writer object pWriter, and if no error has occurred, to flush

  175049. ** all outstanding node buffers held by pWriter to disk.

  175050. **

  175051. ** If *pRc is not SQLITE_OK when this function is called, then no attempt

  175052. ** is made to write any data to disk. Instead, this function serves only

  175053. ** to release outstanding resources.

  175054. **

  175055. ** Otherwise, if *pRc is initially SQLITE_OK and an error occurs while

  175056. ** flushing buffers to disk, *pRc is set to an SQLite error code before

  175057. ** returning.

  175058. */

  175059. static void fts3IncrmergeRelease(

  175060.   Fts3Table *p,                   /* FTS3 table handle */

  175061.   IncrmergeWriter *pWriter,       /* Merge-writer object */

  175062.   int *pRc                        /* IN/OUT: Error code */

  175063. ){

  175064.   int i;                          /* Used to iterate through non-root layers */

  175065.   int iRoot;                      /* Index of root in pWriter->aNodeWriter */

  175066.   NodeWriter *pRoot;              /* NodeWriter for root node */

  175067.   int rc = *pRc;                  /* Error code */

  175068. 

  175069.   /* Set iRoot to the index in pWriter->aNodeWriter[] of the output segment 

  175070.   ** root node. If the segment fits entirely on a single leaf node, iRoot

  175071.   ** will be set to 0. If the root node is the parent of the leaves, iRoot

  175072.   ** will be 1. And so on.  */

  175073.   for(iRoot=FTS_MAX_APPENDABLE_HEIGHT-1; iRoot>=0; iRoot--){

  175074.     NodeWriter *pNode = &pWriter->aNodeWriter[iRoot];

  175075.     if( pNode->block.n>0 ) break;

  175076.     assert( *pRc || pNode->block.nAlloc==0 );

  175077.     assert( *pRc || pNode->key.nAlloc==0 );

  175078.     sqlite3_free(pNode->block.a);

  175079.     sqlite3_free(pNode->key.a);

  175080.   }

  175081. 

  175082.   /* Empty output segment. This is a no-op. */

  175083.   if( iRoot<0 ) return;

  175084. 

  175085.   /* The entire output segment fits on a single node. Normally, this means

  175086.   ** the node would be stored as a blob in the "root" column of the %_segdir

  175087.   ** table. However, this is not permitted in this case. The problem is that 

  175088.   ** space has already been reserved in the %_segments table, and so the 

  175089.   ** start_block and end_block fields of the %_segdir table must be populated. 

  175090.   ** And, by design or by accident, released versions of FTS cannot handle 

  175091.   ** segments that fit entirely on the root node with start_block!=0.

  175092.   **

  175093.   ** Instead, create a synthetic root node that contains nothing but a 

  175094.   ** pointer to the single content node. So that the segment consists of a

  175095.   ** single leaf and a single interior (root) node.

  175096.   **

  175097.   ** Todo: Better might be to defer allocating space in the %_segments 

  175098.   ** table until we are sure it is needed.

  175099.   */

  175100.   if( iRoot==0 ){

  175101.     Blob *pBlock = &pWriter->aNodeWriter[1].block;

  175102.     blobGrowBuffer(pBlock, 1 + FTS3_VARINT_MAX, &rc);

  175103.     if( rc==SQLITE_OK ){

  175104.       pBlock->a[0] = 0x01;

  175105.       pBlock->n = 1 + sqlite3Fts3PutVarint(

  175106.           &pBlock->a[1], pWriter->aNodeWriter[0].iBlock

  175107.       );

  175108.     }

  175109.     iRoot = 1;

  175110.   }

  175111.   pRoot = &pWriter->aNodeWriter[iRoot];

  175112. 

  175113.   /* Flush all currently outstanding nodes to disk. */

  175114.   for(i=0; i<iRoot; i++){

  175115.     NodeWriter *pNode = &pWriter->aNodeWriter[i];

  175116.     if( pNode->block.n>0 && rc==SQLITE_OK ){

  175117.       rc = fts3WriteSegment(p, pNode->iBlock, pNode->block.a, pNode->block.n);

  175118.     }

  175119.     sqlite3_free(pNode->block.a);

  175120.     sqlite3_free(pNode->key.a);

  175121.   }

  175122. 

  175123.   /* Write the %_segdir record. */

  175124.   if( rc==SQLITE_OK ){

  175125.     rc = fts3WriteSegdir(p, 

  175126.         pWriter->iAbsLevel+1,               /* level */

  175127.         pWriter->iIdx,                      /* idx */

  175128.         pWriter->iStart,                    /* start_block */

  175129.         pWriter->aNodeWriter[0].iBlock,     /* leaves_end_block */

  175130.         pWriter->iEnd,                      /* end_block */

  175131.         (pWriter->bNoLeafData==0 ? pWriter->nLeafData : 0),   /* end_block */

  175132.         pRoot->block.a, pRoot->block.n      /* root */

  175133.     );

  175134.   }

  175135.   sqlite3_free(pRoot->block.a);

  175136.   sqlite3_free(pRoot->key.a);

  175137. 

  175138.   *pRc = rc;

  175139. }

  175140. 

  175141. /*

  175142. ** Compare the term in buffer zLhs (size in bytes nLhs) with that in

  175143. ** zRhs (size in bytes nRhs) using memcmp. If one term is a prefix of

  175144. ** the other, it is considered to be smaller than the other.

  175145. **

  175146. ** Return -ve if zLhs is smaller than zRhs, 0 if it is equal, or +ve

  175147. ** if it is greater.

  175148. */

  175149. static int fts3TermCmp(

  175150.   const char *zLhs, int nLhs,     /* LHS of comparison */

  175151.   const char *zRhs, int nRhs      /* RHS of comparison */

  175152. ){

  175153.   int nCmp = MIN(nLhs, nRhs);

  175154.   int res;

  175155. 

  175156.   res = (nCmp ? memcmp(zLhs, zRhs, nCmp) : 0);

  175157.   if( res==0 ) res = nLhs - nRhs;

  175158. 

  175159.   return res;

  175160. }

  175161. 

  175162. 

  175163. /*

  175164. ** Query to see if the entry in the %_segments table with blockid iEnd is 

  175165. ** NULL. If no error occurs and the entry is NULL, set *pbRes 1 before

  175166. ** returning. Otherwise, set *pbRes to 0. 

  175167. **

  175168. ** Or, if an error occurs while querying the database, return an SQLite 

  175169. ** error code. The final value of *pbRes is undefined in this case.

  175170. **

  175171. ** This is used to test if a segment is an "appendable" segment. If it

  175172. ** is, then a NULL entry has been inserted into the %_segments table

  175173. ** with blockid %_segdir.end_block.

  175174. */

  175175. static int fts3IsAppendable(Fts3Table *p, sqlite3_int64 iEnd, int *pbRes){

  175176.   int bRes = 0;                   /* Result to set *pbRes to */

  175177.   sqlite3_stmt *pCheck = 0;       /* Statement to query database with */

  175178.   int rc;                         /* Return code */

  175179. 

  175180.   rc = fts3SqlStmt(p, SQL_SEGMENT_IS_APPENDABLE, &pCheck, 0);

  175181.   if( rc==SQLITE_OK ){

  175182.     sqlite3_bind_int64(pCheck, 1, iEnd);

  175183.     if( SQLITE_ROW==sqlite3_step(pCheck) ) bRes = 1;

  175184.     rc = sqlite3_reset(pCheck);

  175185.   }

  175186.   

  175187.   *pbRes = bRes;

  175188.   return rc;

  175189. }

  175190. 

  175191. /*

  175192. ** This function is called when initializing an incremental-merge operation.

  175193. ** It checks if the existing segment with index value iIdx at absolute level 

  175194. ** (iAbsLevel+1) can be appended to by the incremental merge. If it can, the

  175195. ** merge-writer object *pWriter is initialized to write to it.

  175196. **

  175197. ** An existing segment can be appended to by an incremental merge if:

  175198. **

  175199. **   * It was initially created as an appendable segment (with all required

  175200. **     space pre-allocated), and

  175201. **

  175202. **   * The first key read from the input (arguments zKey and nKey) is 

  175203. **     greater than the largest key currently stored in the potential

  175204. **     output segment.

  175205. */

  175206. static int fts3IncrmergeLoad(

  175207.   Fts3Table *p,                   /* Fts3 table handle */

  175208.   sqlite3_int64 iAbsLevel,        /* Absolute level of input segments */

  175209.   int iIdx,                       /* Index of candidate output segment */

  175210.   const char *zKey,               /* First key to write */

  175211.   int nKey,                       /* Number of bytes in nKey */

  175212.   IncrmergeWriter *pWriter        /* Populate this object */

  175213. ){

  175214.   int rc;                         /* Return code */

  175215.   sqlite3_stmt *pSelect = 0;      /* SELECT to read %_segdir entry */

  175216. 

  175217.   rc = fts3SqlStmt(p, SQL_SELECT_SEGDIR, &pSelect, 0);

  175218.   if( rc==SQLITE_OK ){

  175219.     sqlite3_int64 iStart = 0;     /* Value of %_segdir.start_block */

  175220.     sqlite3_int64 iLeafEnd = 0;   /* Value of %_segdir.leaves_end_block */

  175221.     sqlite3_int64 iEnd = 0;       /* Value of %_segdir.end_block */

  175222.     const char *aRoot = 0;        /* Pointer to %_segdir.root buffer */

  175223.     int nRoot = 0;                /* Size of aRoot[] in bytes */

  175224.     int rc2;                      /* Return code from sqlite3_reset() */

  175225.     int bAppendable = 0;          /* Set to true if segment is appendable */

  175226. 

  175227.     /* Read the %_segdir entry for index iIdx absolute level (iAbsLevel+1) */

  175228.     sqlite3_bind_int64(pSelect, 1, iAbsLevel+1);

  175229.     sqlite3_bind_int(pSelect, 2, iIdx);

  175230.     if( sqlite3_step(pSelect)==SQLITE_ROW ){

  175231.       iStart = sqlite3_column_int64(pSelect, 1);

  175232.       iLeafEnd = sqlite3_column_int64(pSelect, 2);

  175233.       fts3ReadEndBlockField(pSelect, 3, &iEnd, &pWriter->nLeafData);

  175234.       if( pWriter->nLeafData<0 ){

  175235.         pWriter->nLeafData = pWriter->nLeafData * -1;

  175236.       }

  175237.       pWriter->bNoLeafData = (pWriter->nLeafData==0);

  175238.       nRoot = sqlite3_column_bytes(pSelect, 4);

  175239.       aRoot = sqlite3_column_blob(pSelect, 4);

  175240.     }else{

  175241.       return sqlite3_reset(pSelect);

  175242.     }

  175243. 

  175244.     /* Check for the zero-length marker in the %_segments table */

  175245.     rc = fts3IsAppendable(p, iEnd, &bAppendable);

  175246. 

  175247.     /* Check that zKey/nKey is larger than the largest key the candidate */

  175248.     if( rc==SQLITE_OK && bAppendable ){

  175249.       char *aLeaf = 0;

  175250.       int nLeaf = 0;

  175251. 

  175252.       rc = sqlite3Fts3ReadBlock(p, iLeafEnd, &aLeaf, &nLeaf, 0);

  175253.       if( rc==SQLITE_OK ){

  175254.         NodeReader reader;

  175255.         for(rc = nodeReaderInit(&reader, aLeaf, nLeaf);

  175256.             rc==SQLITE_OK && reader.aNode;

  175257.             rc = nodeReaderNext(&reader)

  175258.         ){

  175259.           assert( reader.aNode );

  175260.         }

  175261.         if( fts3TermCmp(zKey, nKey, reader.term.a, reader.term.n)<=0 ){

  175262.           bAppendable = 0;

  175263.         }

  175264.         nodeReaderRelease(&reader);

  175265.       }

  175266.       sqlite3_free(aLeaf);

  175267.     }

  175268. 

  175269.     if( rc==SQLITE_OK && bAppendable ){

  175270.       /* It is possible to append to this segment. Set up the IncrmergeWriter

  175271.       ** object to do so.  */

  175272.       int i;

  175273.       int nHeight = (int)aRoot[0];

  175274.       NodeWriter *pNode;

  175275. 

  175276.       pWriter->nLeafEst = (int)((iEnd - iStart) + 1)/FTS_MAX_APPENDABLE_HEIGHT;

  175277.       pWriter->iStart = iStart;

  175278.       pWriter->iEnd = iEnd;

  175279.       pWriter->iAbsLevel = iAbsLevel;

  175280.       pWriter->iIdx = iIdx;

  175281. 

  175282.       for(i=nHeight+1; i<FTS_MAX_APPENDABLE_HEIGHT; i++){

  175283.         pWriter->aNodeWriter[i].iBlock = pWriter->iStart + i*pWriter->nLeafEst;

  175284.       }

  175285. 

  175286.       pNode = &pWriter->aNodeWriter[nHeight];

  175287.       pNode->iBlock = pWriter->iStart + pWriter->nLeafEst*nHeight;

  175288.       blobGrowBuffer(&pNode->block, 

  175289.           MAX(nRoot, p->nNodeSize)+FTS3_NODE_PADDING, &rc

  175290.       );

  175291.       if( rc==SQLITE_OK ){

  175292.         memcpy(pNode->block.a, aRoot, nRoot);

  175293.         pNode->block.n = nRoot;

  175294.         memset(&pNode->block.a[nRoot], 0, FTS3_NODE_PADDING);

  175295.       }

  175296. 

  175297.       for(i=nHeight; i>=0 && rc==SQLITE_OK; i--){

  175298.         NodeReader reader;

  175299.         pNode = &pWriter->aNodeWriter[i];

  175300. 

  175301.         rc = nodeReaderInit(&reader, pNode->block.a, pNode->block.n);

  175302.         if( reader.aNode ){

  175303.           while( reader.aNode && rc==SQLITE_OK ) rc = nodeReaderNext(&reader);

  175304.           blobGrowBuffer(&pNode->key, reader.term.n, &rc);

  175305.           if( rc==SQLITE_OK ){

  175306.             memcpy(pNode->key.a, reader.term.a, reader.term.n);

  175307.             pNode->key.n = reader.term.n;

  175308.             if( i>0 ){

  175309.               char *aBlock = 0;

  175310.               int nBlock = 0;

  175311.               pNode = &pWriter->aNodeWriter[i-1];

  175312.               pNode->iBlock = reader.iChild;

  175313.               rc = sqlite3Fts3ReadBlock(p, reader.iChild, &aBlock, &nBlock, 0);

  175314.               blobGrowBuffer(&pNode->block, 

  175315.                   MAX(nBlock, p->nNodeSize)+FTS3_NODE_PADDING, &rc

  175316.               );

  175317.               if( rc==SQLITE_OK ){

  175318.                 memcpy(pNode->block.a, aBlock, nBlock);

  175319.                 pNode->block.n = nBlock;

  175320.                 memset(&pNode->block.a[nBlock], 0, FTS3_NODE_PADDING);

  175321.               }

  175322.               sqlite3_free(aBlock);

  175323.             }

  175324.           }

  175325.         }

  175326.         nodeReaderRelease(&reader);

  175327.       }

  175328.     }

  175329. 

  175330.     rc2 = sqlite3_reset(pSelect);

  175331.     if( rc==SQLITE_OK ) rc = rc2;

  175332.   }

  175333. 

  175334.   return rc;

  175335. }

  175336. 

  175337. /*

  175338. ** Determine the largest segment index value that exists within absolute

  175339. ** level iAbsLevel+1. If no error occurs, set *piIdx to this value plus

  175340. ** one before returning SQLITE_OK. Or, if there are no segments at all 

  175341. ** within level iAbsLevel, set *piIdx to zero.

  175342. **

  175343. ** If an error occurs, return an SQLite error code. The final value of

  175344. ** *piIdx is undefined in this case.

  175345. */

  175346. static int fts3IncrmergeOutputIdx( 

  175347.   Fts3Table *p,                   /* FTS Table handle */

  175348.   sqlite3_int64 iAbsLevel,        /* Absolute index of input segments */

  175349.   int *piIdx                      /* OUT: Next free index at iAbsLevel+1 */

  175350. ){

  175351.   int rc;

  175352.   sqlite3_stmt *pOutputIdx = 0;   /* SQL used to find output index */

  175353. 

  175354.   rc = fts3SqlStmt(p, SQL_NEXT_SEGMENT_INDEX, &pOutputIdx, 0);

  175355.   if( rc==SQLITE_OK ){

  175356.     sqlite3_bind_int64(pOutputIdx, 1, iAbsLevel+1);

  175357.     sqlite3_step(pOutputIdx);

  175358.     *piIdx = sqlite3_column_int(pOutputIdx, 0);

  175359.     rc = sqlite3_reset(pOutputIdx);

  175360.   }

  175361. 

  175362.   return rc;

  175363. }

  175364. 

  175365. /* 

  175366. ** Allocate an appendable output segment on absolute level iAbsLevel+1

  175367. ** with idx value iIdx.

  175368. **

  175369. ** In the %_segdir table, a segment is defined by the values in three

  175370. ** columns:

  175371. **

  175372. **     start_block

  175373. **     leaves_end_block

  175374. **     end_block

  175375. **

  175376. ** When an appendable segment is allocated, it is estimated that the

  175377. ** maximum number of leaf blocks that may be required is the sum of the

  175378. ** number of leaf blocks consumed by the input segments, plus the number

  175379. ** of input segments, multiplied by two. This value is stored in stack 

  175380. ** variable nLeafEst.

  175381. **

  175382. ** A total of 16*nLeafEst blocks are allocated when an appendable segment

  175383. ** is created ((1 + end_block - start_block)==16*nLeafEst). The contiguous

  175384. ** array of leaf nodes starts at the first block allocated. The array

  175385. ** of interior nodes that are parents of the leaf nodes start at block

  175386. ** (start_block + (1 + end_block - start_block) / 16). And so on.

  175387. **

  175388. ** In the actual code below, the value "16" is replaced with the 

  175389. ** pre-processor macro FTS_MAX_APPENDABLE_HEIGHT.

  175390. */

  175391. static int fts3IncrmergeWriter( 

  175392.   Fts3Table *p,                   /* Fts3 table handle */

  175393.   sqlite3_int64 iAbsLevel,        /* Absolute level of input segments */

  175394.   int iIdx,                       /* Index of new output segment */

  175395.   Fts3MultiSegReader *pCsr,       /* Cursor that data will be read from */

  175396.   IncrmergeWriter *pWriter        /* Populate this object */

  175397. ){

  175398.   int rc;                         /* Return Code */

  175399.   int i;                          /* Iterator variable */

  175400.   int nLeafEst = 0;               /* Blocks allocated for leaf nodes */

  175401.   sqlite3_stmt *pLeafEst = 0;     /* SQL used to determine nLeafEst */

  175402.   sqlite3_stmt *pFirstBlock = 0;  /* SQL used to determine first block */

  175403. 

  175404.   /* Calculate nLeafEst. */

  175405.   rc = fts3SqlStmt(p, SQL_MAX_LEAF_NODE_ESTIMATE, &pLeafEst, 0);

  175406.   if( rc==SQLITE_OK ){

  175407.     sqlite3_bind_int64(pLeafEst, 1, iAbsLevel);

  175408.     sqlite3_bind_int64(pLeafEst, 2, pCsr->nSegment);

  175409.     if( SQLITE_ROW==sqlite3_step(pLeafEst) ){

  175410.       nLeafEst = sqlite3_column_int(pLeafEst, 0);

  175411.     }

  175412.     rc = sqlite3_reset(pLeafEst);

  175413.   }

  175414.   if( rc!=SQLITE_OK ) return rc;

  175415. 

  175416.   /* Calculate the first block to use in the output segment */

  175417.   rc = fts3SqlStmt(p, SQL_NEXT_SEGMENTS_ID, &pFirstBlock, 0);

  175418.   if( rc==SQLITE_OK ){

  175419.     if( SQLITE_ROW==sqlite3_step(pFirstBlock) ){

  175420.       pWriter->iStart = sqlite3_column_int64(pFirstBlock, 0);

  175421.       pWriter->iEnd = pWriter->iStart - 1;

  175422.       pWriter->iEnd += nLeafEst * FTS_MAX_APPENDABLE_HEIGHT;

  175423.     }

  175424.     rc = sqlite3_reset(pFirstBlock);

  175425.   }

  175426.   if( rc!=SQLITE_OK ) return rc;

  175427. 

  175428.   /* Insert the marker in the %_segments table to make sure nobody tries

  175429.   ** to steal the space just allocated. This is also used to identify 

  175430.   ** appendable segments.  */

  175431.   rc = fts3WriteSegment(p, pWriter->iEnd, 0, 0);

  175432.   if( rc!=SQLITE_OK ) return rc;

  175433. 

  175434.   pWriter->iAbsLevel = iAbsLevel;

  175435.   pWriter->nLeafEst = nLeafEst;

  175436.   pWriter->iIdx = iIdx;

  175437. 

  175438.   /* Set up the array of NodeWriter objects */

  175439.   for(i=0; i<FTS_MAX_APPENDABLE_HEIGHT; i++){

  175440.     pWriter->aNodeWriter[i].iBlock = pWriter->iStart + i*pWriter->nLeafEst;

  175441.   }

  175442.   return SQLITE_OK;

  175443. }

  175444. 

  175445. /*

  175446. ** Remove an entry from the %_segdir table. This involves running the 

  175447. ** following two statements:

  175448. **

  175449. **   DELETE FROM %_segdir WHERE level = :iAbsLevel AND idx = :iIdx

  175450. **   UPDATE %_segdir SET idx = idx - 1 WHERE level = :iAbsLevel AND idx > :iIdx

  175451. **

  175452. ** The DELETE statement removes the specific %_segdir level. The UPDATE 

  175453. ** statement ensures that the remaining segments have contiguously allocated

  175454. ** idx values.

  175455. */

  175456. static int fts3RemoveSegdirEntry(

  175457.   Fts3Table *p,                   /* FTS3 table handle */

  175458.   sqlite3_int64 iAbsLevel,        /* Absolute level to delete from */

  175459.   int iIdx                        /* Index of %_segdir entry to delete */

  175460. ){

  175461.   int rc;                         /* Return code */

  175462.   sqlite3_stmt *pDelete = 0;      /* DELETE statement */

  175463. 

  175464.   rc = fts3SqlStmt(p, SQL_DELETE_SEGDIR_ENTRY, &pDelete, 0);

  175465.   if( rc==SQLITE_OK ){

  175466.     sqlite3_bind_int64(pDelete, 1, iAbsLevel);

  175467.     sqlite3_bind_int(pDelete, 2, iIdx);

  175468.     sqlite3_step(pDelete);

  175469.     rc = sqlite3_reset(pDelete);

  175470.   }

  175471. 

  175472.   return rc;

  175473. }

  175474. 

  175475. /*

  175476. ** One or more segments have just been removed from absolute level iAbsLevel.

  175477. ** Update the 'idx' values of the remaining segments in the level so that

  175478. ** the idx values are a contiguous sequence starting from 0.

  175479. */

  175480. static int fts3RepackSegdirLevel(

  175481.   Fts3Table *p,                   /* FTS3 table handle */

  175482.   sqlite3_int64 iAbsLevel         /* Absolute level to repack */

  175483. ){

  175484.   int rc;                         /* Return code */

  175485.   int *aIdx = 0;                  /* Array of remaining idx values */

  175486.   int nIdx = 0;                   /* Valid entries in aIdx[] */

  175487.   int nAlloc = 0;                 /* Allocated size of aIdx[] */

  175488.   int i;                          /* Iterator variable */

  175489.   sqlite3_stmt *pSelect = 0;      /* Select statement to read idx values */

  175490.   sqlite3_stmt *pUpdate = 0;      /* Update statement to modify idx values */

  175491. 

  175492.   rc = fts3SqlStmt(p, SQL_SELECT_INDEXES, &pSelect, 0);

  175493.   if( rc==SQLITE_OK ){

  175494.     int rc2;

  175495.     sqlite3_bind_int64(pSelect, 1, iAbsLevel);

  175496.     while( SQLITE_ROW==sqlite3_step(pSelect) ){

  175497.       if( nIdx>=nAlloc ){

  175498.         int *aNew;

  175499.         nAlloc += 16;

  175500.         aNew = sqlite3_realloc(aIdx, nAlloc*sizeof(int));

  175501.         if( !aNew ){

  175502.           rc = SQLITE_NOMEM;

  175503.           break;

  175504.         }

  175505.         aIdx = aNew;

  175506.       }

  175507.       aIdx[nIdx++] = sqlite3_column_int(pSelect, 0);

  175508.     }

  175509.     rc2 = sqlite3_reset(pSelect);

  175510.     if( rc==SQLITE_OK ) rc = rc2;

  175511.   }

  175512. 

  175513.   if( rc==SQLITE_OK ){

  175514.     rc = fts3SqlStmt(p, SQL_SHIFT_SEGDIR_ENTRY, &pUpdate, 0);

  175515.   }

  175516.   if( rc==SQLITE_OK ){

  175517.     sqlite3_bind_int64(pUpdate, 2, iAbsLevel);

  175518.   }

  175519. 

  175520.   assert( p->bIgnoreSavepoint==0 );

  175521.   p->bIgnoreSavepoint = 1;

  175522.   for(i=0; rc==SQLITE_OK && i<nIdx; i++){

  175523.     if( aIdx[i]!=i ){

  175524.       sqlite3_bind_int(pUpdate, 3, aIdx[i]);

  175525.       sqlite3_bind_int(pUpdate, 1, i);

  175526.       sqlite3_step(pUpdate);

  175527.       rc = sqlite3_reset(pUpdate);

  175528.     }

  175529.   }

  175530.   p->bIgnoreSavepoint = 0;

  175531. 

  175532.   sqlite3_free(aIdx);

  175533.   return rc;

  175534. }

  175535. 

  175536. static void fts3StartNode(Blob *pNode, int iHeight, sqlite3_int64 iChild){

  175537.   pNode->a[0] = (char)iHeight;

  175538.   if( iChild ){

  175539.     assert( pNode->nAlloc>=1+sqlite3Fts3VarintLen(iChild) );

  175540.     pNode->n = 1 + sqlite3Fts3PutVarint(&pNode->a[1], iChild);

  175541.   }else{

  175542.     assert( pNode->nAlloc>=1 );

  175543.     pNode->n = 1;

  175544.   }

  175545. }

  175546. 

  175547. /*

  175548. ** The first two arguments are a pointer to and the size of a segment b-tree

  175549. ** node. The node may be a leaf or an internal node.

  175550. **

  175551. ** This function creates a new node image in blob object *pNew by copying

  175552. ** all terms that are greater than or equal to zTerm/nTerm (for leaf nodes)

  175553. ** or greater than zTerm/nTerm (for internal nodes) from aNode/nNode.

  175554. */

  175555. static int fts3TruncateNode(

  175556.   const char *aNode,              /* Current node image */

  175557.   int nNode,                      /* Size of aNode in bytes */

  175558.   Blob *pNew,                     /* OUT: Write new node image here */

  175559.   const char *zTerm,              /* Omit all terms smaller than this */

  175560.   int nTerm,                      /* Size of zTerm in bytes */

  175561.   sqlite3_int64 *piBlock          /* OUT: Block number in next layer down */

  175562. ){

  175563.   NodeReader reader;              /* Reader object */

  175564.   Blob prev = {0, 0, 0};          /* Previous term written to new node */

  175565.   int rc = SQLITE_OK;             /* Return code */

  175566.   int bLeaf;                       /* True for a leaf node */

  175567. 

  175568.   if( nNode<1 ) return FTS_CORRUPT_VTAB;

  175569.   bLeaf = aNode[0]=='\0';

  175570. 

  175571.   /* Allocate required output space */

  175572.   blobGrowBuffer(pNew, nNode, &rc);

  175573.   if( rc!=SQLITE_OK ) return rc;

  175574.   pNew->n = 0;

  175575. 

  175576.   /* Populate new node buffer */

  175577.   for(rc = nodeReaderInit(&reader, aNode, nNode); 

  175578.       rc==SQLITE_OK && reader.aNode; 

  175579.       rc = nodeReaderNext(&reader)

  175580.   ){

  175581.     if( pNew->n==0 ){

  175582.       int res = fts3TermCmp(reader.term.a, reader.term.n, zTerm, nTerm);

  175583.       if( res<0 || (bLeaf==0 && res==0) ) continue;

  175584.       fts3StartNode(pNew, (int)aNode[0], reader.iChild);

  175585.       *piBlock = reader.iChild;

  175586.     }

  175587.     rc = fts3AppendToNode(

  175588.         pNew, &prev, reader.term.a, reader.term.n,

  175589.         reader.aDoclist, reader.nDoclist

  175590.     );

  175591.     if( rc!=SQLITE_OK ) break;

  175592.   }

  175593.   if( pNew->n==0 ){

  175594.     fts3StartNode(pNew, (int)aNode[0], reader.iChild);

  175595.     *piBlock = reader.iChild;

  175596.   }

  175597.   assert( pNew->n<=pNew->nAlloc );

  175598. 

  175599.   nodeReaderRelease(&reader);

  175600.   sqlite3_free(prev.a);

  175601.   return rc;

  175602. }

  175603. 

  175604. /*

  175605. ** Remove all terms smaller than zTerm/nTerm from segment iIdx in absolute 

  175606. ** level iAbsLevel. This may involve deleting entries from the %_segments

  175607. ** table, and modifying existing entries in both the %_segments and %_segdir

  175608. ** tables.

  175609. **

  175610. ** SQLITE_OK is returned if the segment is updated successfully. Or an

  175611. ** SQLite error code otherwise.

  175612. */

  175613. static int fts3TruncateSegment(

  175614.   Fts3Table *p,                   /* FTS3 table handle */

  175615.   sqlite3_int64 iAbsLevel,        /* Absolute level of segment to modify */

  175616.   int iIdx,                       /* Index within level of segment to modify */

  175617.   const char *zTerm,              /* Remove terms smaller than this */

  175618.   int nTerm                      /* Number of bytes in buffer zTerm */

  175619. ){

  175620.   int rc = SQLITE_OK;             /* Return code */

  175621.   Blob root = {0,0,0};            /* New root page image */

  175622.   Blob block = {0,0,0};           /* Buffer used for any other block */

  175623.   sqlite3_int64 iBlock = 0;       /* Block id */

  175624.   sqlite3_int64 iNewStart = 0;    /* New value for iStartBlock */

  175625.   sqlite3_int64 iOldStart = 0;    /* Old value for iStartBlock */

  175626.   sqlite3_stmt *pFetch = 0;       /* Statement used to fetch segdir */

  175627. 

  175628.   rc = fts3SqlStmt(p, SQL_SELECT_SEGDIR, &pFetch, 0);

  175629.   if( rc==SQLITE_OK ){

  175630.     int rc2;                      /* sqlite3_reset() return code */

  175631.     sqlite3_bind_int64(pFetch, 1, iAbsLevel);

  175632.     sqlite3_bind_int(pFetch, 2, iIdx);

  175633.     if( SQLITE_ROW==sqlite3_step(pFetch) ){

  175634.       const char *aRoot = sqlite3_column_blob(pFetch, 4);

  175635.       int nRoot = sqlite3_column_bytes(pFetch, 4);

  175636.       iOldStart = sqlite3_column_int64(pFetch, 1);

  175637.       rc = fts3TruncateNode(aRoot, nRoot, &root, zTerm, nTerm, &iBlock);

  175638.     }

  175639.     rc2 = sqlite3_reset(pFetch);

  175640.     if( rc==SQLITE_OK ) rc = rc2;

  175641.   }

  175642. 

  175643.   while( rc==SQLITE_OK && iBlock ){

  175644.     char *aBlock = 0;

  175645.     int nBlock = 0;

  175646.     iNewStart = iBlock;

  175647. 

  175648.     rc = sqlite3Fts3ReadBlock(p, iBlock, &aBlock, &nBlock, 0);

  175649.     if( rc==SQLITE_OK ){

  175650.       rc = fts3TruncateNode(aBlock, nBlock, &block, zTerm, nTerm, &iBlock);

  175651.     }

  175652.     if( rc==SQLITE_OK ){

  175653.       rc = fts3WriteSegment(p, iNewStart, block.a, block.n);

  175654.     }

  175655.     sqlite3_free(aBlock);

  175656.   }

  175657. 

  175658.   /* Variable iNewStart now contains the first valid leaf node. */

  175659.   if( rc==SQLITE_OK && iNewStart ){

  175660.     sqlite3_stmt *pDel = 0;

  175661.     rc = fts3SqlStmt(p, SQL_DELETE_SEGMENTS_RANGE, &pDel, 0);

  175662.     if( rc==SQLITE_OK ){

  175663.       sqlite3_bind_int64(pDel, 1, iOldStart);

  175664.       sqlite3_bind_int64(pDel, 2, iNewStart-1);

  175665.       sqlite3_step(pDel);

  175666.       rc = sqlite3_reset(pDel);

  175667.     }

  175668.   }

  175669. 

  175670.   if( rc==SQLITE_OK ){

  175671.     sqlite3_stmt *pChomp = 0;

  175672.     rc = fts3SqlStmt(p, SQL_CHOMP_SEGDIR, &pChomp, 0);

  175673.     if( rc==SQLITE_OK ){

  175674.       sqlite3_bind_int64(pChomp, 1, iNewStart);

  175675.       sqlite3_bind_blob(pChomp, 2, root.a, root.n, SQLITE_STATIC);

  175676.       sqlite3_bind_int64(pChomp, 3, iAbsLevel);

  175677.       sqlite3_bind_int(pChomp, 4, iIdx);

  175678.       sqlite3_step(pChomp);

  175679.       rc = sqlite3_reset(pChomp);

  175680.       sqlite3_bind_null(pChomp, 2);

  175681.     }

  175682.   }

  175683. 

  175684.   sqlite3_free(root.a);

  175685.   sqlite3_free(block.a);

  175686.   return rc;

  175687. }

  175688. 

  175689. /*

  175690. ** This function is called after an incrmental-merge operation has run to

  175691. ** merge (or partially merge) two or more segments from absolute level

  175692. ** iAbsLevel.

  175693. **

  175694. ** Each input segment is either removed from the db completely (if all of

  175695. ** its data was copied to the output segment by the incrmerge operation)

  175696. ** or modified in place so that it no longer contains those entries that

  175697. ** have been duplicated in the output segment.

  175698. */

  175699. static int fts3IncrmergeChomp(

  175700.   Fts3Table *p,                   /* FTS table handle */

  175701.   sqlite3_int64 iAbsLevel,        /* Absolute level containing segments */

  175702.   Fts3MultiSegReader *pCsr,       /* Chomp all segments opened by this cursor */

  175703.   int *pnRem                      /* Number of segments not deleted */

  175704. ){

  175705.   int i;

  175706.   int nRem = 0;

  175707.   int rc = SQLITE_OK;

  175708. 

  175709.   for(i=pCsr->nSegment-1; i>=0 && rc==SQLITE_OK; i--){

  175710.     Fts3SegReader *pSeg = 0;

  175711.     int j;

  175712. 

  175713.     /* Find the Fts3SegReader object with Fts3SegReader.iIdx==i. It is hiding

  175714.     ** somewhere in the pCsr->apSegment[] array.  */

  175715.     for(j=0; ALWAYS(j<pCsr->nSegment); j++){

  175716.       pSeg = pCsr->apSegment[j];

  175717.       if( pSeg->iIdx==i ) break;

  175718.     }

  175719.     assert( j<pCsr->nSegment && pSeg->iIdx==i );

  175720. 

  175721.     if( pSeg->aNode==0 ){

  175722.       /* Seg-reader is at EOF. Remove the entire input segment. */

  175723.       rc = fts3DeleteSegment(p, pSeg);

  175724.       if( rc==SQLITE_OK ){

  175725.         rc = fts3RemoveSegdirEntry(p, iAbsLevel, pSeg->iIdx);

  175726.       }

  175727.       *pnRem = 0;

  175728.     }else{

  175729.       /* The incremental merge did not copy all the data from this 

  175730.       ** segment to the upper level. The segment is modified in place

  175731.       ** so that it contains no keys smaller than zTerm/nTerm. */ 

  175732.       const char *zTerm = pSeg->zTerm;

  175733.       int nTerm = pSeg->nTerm;

  175734.       rc = fts3TruncateSegment(p, iAbsLevel, pSeg->iIdx, zTerm, nTerm);

  175735.       nRem++;

  175736.     }

  175737.   }

  175738. 

  175739.   if( rc==SQLITE_OK && nRem!=pCsr->nSegment ){

  175740.     rc = fts3RepackSegdirLevel(p, iAbsLevel);

  175741.   }

  175742. 

  175743.   *pnRem = nRem;

  175744.   return rc;

  175745. }

  175746. 

  175747. /*

  175748. ** Store an incr-merge hint in the database.

  175749. */

  175750. static int fts3IncrmergeHintStore(Fts3Table *p, Blob *pHint){

  175751.   sqlite3_stmt *pReplace = 0;

  175752.   int rc;                         /* Return code */

  175753. 

  175754.   rc = fts3SqlStmt(p, SQL_REPLACE_STAT, &pReplace, 0);

  175755.   if( rc==SQLITE_OK ){

  175756.     sqlite3_bind_int(pReplace, 1, FTS_STAT_INCRMERGEHINT);

  175757.     sqlite3_bind_blob(pReplace, 2, pHint->a, pHint->n, SQLITE_STATIC);

  175758.     sqlite3_step(pReplace);

  175759.     rc = sqlite3_reset(pReplace);

  175760.     sqlite3_bind_null(pReplace, 2);

  175761.   }

  175762. 

  175763.   return rc;

  175764. }

  175765. 

  175766. /*

  175767. ** Load an incr-merge hint from the database. The incr-merge hint, if one 

  175768. ** exists, is stored in the rowid==1 row of the %_stat table.

  175769. **

  175770. ** If successful, populate blob *pHint with the value read from the %_stat

  175771. ** table and return SQLITE_OK. Otherwise, if an error occurs, return an

  175772. ** SQLite error code.

  175773. */

  175774. static int fts3IncrmergeHintLoad(Fts3Table *p, Blob *pHint){

  175775.   sqlite3_stmt *pSelect = 0;

  175776.   int rc;

  175777. 

  175778.   pHint->n = 0;

  175779.   rc = fts3SqlStmt(p, SQL_SELECT_STAT, &pSelect, 0);

  175780.   if( rc==SQLITE_OK ){

  175781.     int rc2;

  175782.     sqlite3_bind_int(pSelect, 1, FTS_STAT_INCRMERGEHINT);

  175783.     if( SQLITE_ROW==sqlite3_step(pSelect) ){

  175784.       const char *aHint = sqlite3_column_blob(pSelect, 0);

  175785.       int nHint = sqlite3_column_bytes(pSelect, 0);

  175786.       if( aHint ){

  175787.         blobGrowBuffer(pHint, nHint, &rc);

  175788.         if( rc==SQLITE_OK ){

  175789.           memcpy(pHint->a, aHint, nHint);

  175790.           pHint->n = nHint;

  175791.         }

  175792.       }

  175793.     }

  175794.     rc2 = sqlite3_reset(pSelect);

  175795.     if( rc==SQLITE_OK ) rc = rc2;

  175796.   }

  175797. 

  175798.   return rc;

  175799. }

  175800. 

  175801. /*

  175802. ** If *pRc is not SQLITE_OK when this function is called, it is a no-op.

  175803. ** Otherwise, append an entry to the hint stored in blob *pHint. Each entry

  175804. ** consists of two varints, the absolute level number of the input segments 

  175805. ** and the number of input segments.

  175806. **

  175807. ** If successful, leave *pRc set to SQLITE_OK and return. If an error occurs,

  175808. ** set *pRc to an SQLite error code before returning.

  175809. */

  175810. static void fts3IncrmergeHintPush(

  175811.   Blob *pHint,                    /* Hint blob to append to */

  175812.   i64 iAbsLevel,                  /* First varint to store in hint */

  175813.   int nInput,                     /* Second varint to store in hint */

  175814.   int *pRc                        /* IN/OUT: Error code */

  175815. ){

  175816.   blobGrowBuffer(pHint, pHint->n + 2*FTS3_VARINT_MAX, pRc);

  175817.   if( *pRc==SQLITE_OK ){

  175818.     pHint->n += sqlite3Fts3PutVarint(&pHint->a[pHint->n], iAbsLevel);

  175819.     pHint->n += sqlite3Fts3PutVarint(&pHint->a[pHint->n], (i64)nInput);

  175820.   }

  175821. }

  175822. 

  175823. /*

  175824. ** Read the last entry (most recently pushed) from the hint blob *pHint

  175825. ** and then remove the entry. Write the two values read to *piAbsLevel and 

  175826. ** *pnInput before returning.

  175827. **

  175828. ** If no error occurs, return SQLITE_OK. If the hint blob in *pHint does

  175829. ** not contain at least two valid varints, return SQLITE_CORRUPT_VTAB.

  175830. */

  175831. static int fts3IncrmergeHintPop(Blob *pHint, i64 *piAbsLevel, int *pnInput){

  175832.   const int nHint = pHint->n;

  175833.   int i;

  175834. 

  175835.   i = pHint->n-2;

  175836.   while( i>0 && (pHint->a[i-1] & 0x80) ) i--;

  175837.   while( i>0 && (pHint->a[i-1] & 0x80) ) i--;

  175838. 

  175839.   pHint->n = i;

  175840.   i += sqlite3Fts3GetVarint(&pHint->a[i], piAbsLevel);

  175841.   i += fts3GetVarint32(&pHint->a[i], pnInput);

  175842.   if( i!=nHint ) return FTS_CORRUPT_VTAB;

  175843. 

  175844.   return SQLITE_OK;

  175845. }

  175846. 

  175847. 

  175848. /*

  175849. ** Attempt an incremental merge that writes nMerge leaf blocks.

  175850. **

  175851. ** Incremental merges happen nMin segments at a time. The segments 

  175852. ** to be merged are the nMin oldest segments (the ones with the smallest 

  175853. ** values for the _segdir.idx field) in the highest level that contains 

  175854. ** at least nMin segments. Multiple merges might occur in an attempt to 

  175855. ** write the quota of nMerge leaf blocks.

  175856. */

  175857. SQLITE_PRIVATE int sqlite3Fts3Incrmerge(Fts3Table *p, int nMerge, int nMin){

  175858.   int rc;                         /* Return code */

  175859.   int nRem = nMerge;              /* Number of leaf pages yet to  be written */

  175860.   Fts3MultiSegReader *pCsr;       /* Cursor used to read input data */

  175861.   Fts3SegFilter *pFilter;         /* Filter used with cursor pCsr */

  175862.   IncrmergeWriter *pWriter;       /* Writer object */

  175863.   int nSeg = 0;                   /* Number of input segments */

  175864.   sqlite3_int64 iAbsLevel = 0;    /* Absolute level number to work on */

  175865.   Blob hint = {0, 0, 0};          /* Hint read from %_stat table */

  175866.   int bDirtyHint = 0;             /* True if blob 'hint' has been modified */

  175867. 

  175868.   /* Allocate space for the cursor, filter and writer objects */

  175869.   const int nAlloc = sizeof(*pCsr) + sizeof(*pFilter) + sizeof(*pWriter);

  175870.   pWriter = (IncrmergeWriter *)sqlite3_malloc(nAlloc);

  175871.   if( !pWriter ) return SQLITE_NOMEM;

  175872.   pFilter = (Fts3SegFilter *)&pWriter[1];

  175873.   pCsr = (Fts3MultiSegReader *)&pFilter[1];

  175874. 

  175875.   rc = fts3IncrmergeHintLoad(p, &hint);

  175876.   while( rc==SQLITE_OK && nRem>0 ){

  175877.     const i64 nMod = FTS3_SEGDIR_MAXLEVEL * p->nIndex;

  175878.     sqlite3_stmt *pFindLevel = 0; /* SQL used to determine iAbsLevel */

  175879.     int bUseHint = 0;             /* True if attempting to append */

  175880.     int iIdx = 0;                 /* Largest idx in level (iAbsLevel+1) */

  175881. 

  175882.     /* Search the %_segdir table for the absolute level with the smallest

  175883.     ** relative level number that contains at least nMin segments, if any.

  175884.     ** If one is found, set iAbsLevel to the absolute level number and

  175885.     ** nSeg to nMin. If no level with at least nMin segments can be found, 

  175886.     ** set nSeg to -1.

  175887.     */

  175888.     rc = fts3SqlStmt(p, SQL_FIND_MERGE_LEVEL, &pFindLevel, 0);

  175889.     sqlite3_bind_int(pFindLevel, 1, MAX(2, nMin));

  175890.     if( sqlite3_step(pFindLevel)==SQLITE_ROW ){

  175891.       iAbsLevel = sqlite3_column_int64(pFindLevel, 0);

  175892.       nSeg = sqlite3_column_int(pFindLevel, 1);

  175893.       assert( nSeg>=2 );

  175894.     }else{

  175895.       nSeg = -1;

  175896.     }

  175897.     rc = sqlite3_reset(pFindLevel);

  175898. 

  175899.     /* If the hint read from the %_stat table is not empty, check if the

  175900.     ** last entry in it specifies a relative level smaller than or equal

  175901.     ** to the level identified by the block above (if any). If so, this 

  175902.     ** iteration of the loop will work on merging at the hinted level.

  175903.     */

  175904.     if( rc==SQLITE_OK && hint.n ){

  175905.       int nHint = hint.n;

  175906.       sqlite3_int64 iHintAbsLevel = 0;      /* Hint level */

  175907.       int nHintSeg = 0;                     /* Hint number of segments */

  175908. 

  175909.       rc = fts3IncrmergeHintPop(&hint, &iHintAbsLevel, &nHintSeg);

  175910.       if( nSeg<0 || (iAbsLevel % nMod) >= (iHintAbsLevel % nMod) ){

  175911.         iAbsLevel = iHintAbsLevel;

  175912.         nSeg = nHintSeg;

  175913.         bUseHint = 1;

  175914.         bDirtyHint = 1;

  175915.       }else{

  175916.         /* This undoes the effect of the HintPop() above - so that no entry

  175917.         ** is removed from the hint blob.  */

  175918.         hint.n = nHint;

  175919.       }

  175920.     }

  175921. 

  175922.     /* If nSeg is less that zero, then there is no level with at least

  175923.     ** nMin segments and no hint in the %_stat table. No work to do.

  175924.     ** Exit early in this case.  */

  175925.     if( nSeg<0 ) break;

  175926. 

  175927.     /* Open a cursor to iterate through the contents of the oldest nSeg 

  175928.     ** indexes of absolute level iAbsLevel. If this cursor is opened using 

  175929.     ** the 'hint' parameters, it is possible that there are less than nSeg

  175930.     ** segments available in level iAbsLevel. In this case, no work is

  175931.     ** done on iAbsLevel - fall through to the next iteration of the loop 

  175932.     ** to start work on some other level.  */

  175933.     memset(pWriter, 0, nAlloc);

  175934.     pFilter->flags = FTS3_SEGMENT_REQUIRE_POS;

  175935. 

  175936.     if( rc==SQLITE_OK ){

  175937.       rc = fts3IncrmergeOutputIdx(p, iAbsLevel, &iIdx);

  175938.       assert( bUseHint==1 || bUseHint==0 );

  175939.       if( iIdx==0 || (bUseHint && iIdx==1) ){

  175940.         int bIgnore = 0;

  175941.         rc = fts3SegmentIsMaxLevel(p, iAbsLevel+1, &bIgnore);

  175942.         if( bIgnore ){

  175943.           pFilter->flags |= FTS3_SEGMENT_IGNORE_EMPTY;

  175944.         }

  175945.       }

  175946.     }

  175947. 

  175948.     if( rc==SQLITE_OK ){

  175949.       rc = fts3IncrmergeCsr(p, iAbsLevel, nSeg, pCsr);

  175950.     }

  175951.     if( SQLITE_OK==rc && pCsr->nSegment==nSeg

  175952.      && SQLITE_OK==(rc = sqlite3Fts3SegReaderStart(p, pCsr, pFilter))

  175953.      && SQLITE_ROW==(rc = sqlite3Fts3SegReaderStep(p, pCsr))

  175954.     ){

  175955.       if( bUseHint && iIdx>0 ){

  175956.         const char *zKey = pCsr->zTerm;

  175957.         int nKey = pCsr->nTerm;

  175958.         rc = fts3IncrmergeLoad(p, iAbsLevel, iIdx-1, zKey, nKey, pWriter);

  175959.       }else{

  175960.         rc = fts3IncrmergeWriter(p, iAbsLevel, iIdx, pCsr, pWriter);

  175961.       }

  175962. 

  175963.       if( rc==SQLITE_OK && pWriter->nLeafEst ){

  175964.         fts3LogMerge(nSeg, iAbsLevel);

  175965.         do {

  175966.           rc = fts3IncrmergeAppend(p, pWriter, pCsr);

  175967.           if( rc==SQLITE_OK ) rc = sqlite3Fts3SegReaderStep(p, pCsr);

  175968.           if( pWriter->nWork>=nRem && rc==SQLITE_ROW ) rc = SQLITE_OK;

  175969.         }while( rc==SQLITE_ROW );

  175970. 

  175971.         /* Update or delete the input segments */

  175972.         if( rc==SQLITE_OK ){

  175973.           nRem -= (1 + pWriter->nWork);

  175974.           rc = fts3IncrmergeChomp(p, iAbsLevel, pCsr, &nSeg);

  175975.           if( nSeg!=0 ){

  175976.             bDirtyHint = 1;

  175977.             fts3IncrmergeHintPush(&hint, iAbsLevel, nSeg, &rc);

  175978.           }

  175979.         }

  175980.       }

  175981. 

  175982.       if( nSeg!=0 ){

  175983.         pWriter->nLeafData = pWriter->nLeafData * -1;

  175984.       }

  175985.       fts3IncrmergeRelease(p, pWriter, &rc);

  175986.       if( nSeg==0 && pWriter->bNoLeafData==0 ){

  175987.         fts3PromoteSegments(p, iAbsLevel+1, pWriter->nLeafData);

  175988.       }

  175989.     }

  175990. 

  175991.     sqlite3Fts3SegReaderFinish(pCsr);

  175992.   }

  175993. 

  175994.   /* Write the hint values into the %_stat table for the next incr-merger */

  175995.   if( bDirtyHint && rc==SQLITE_OK ){

  175996.     rc = fts3IncrmergeHintStore(p, &hint);

  175997.   }

  175998. 

  175999.   sqlite3_free(pWriter);

  176000.   sqlite3_free(hint.a);

  176001.   return rc;

  176002. }

  176003. 

  176004. /*

  176005. ** Convert the text beginning at *pz into an integer and return

  176006. ** its value.  Advance *pz to point to the first character past

  176007. ** the integer.

  176008. **

  176009. ** This function used for parameters to merge= and incrmerge=

  176010. ** commands. 

  176011. */

  176012. static int fts3Getint(const char **pz){

  176013.   const char *z = *pz;

  176014.   int i = 0;

  176015.   while( (*z)>='0' && (*z)<='9' && i<214748363 ) i = 10*i + *(z++) - '0';

  176016.   *pz = z;

  176017.   return i;

  176018. }

  176019. 

  176020. /*

  176021. ** Process statements of the form:

  176022. **

  176023. **    INSERT INTO table(table) VALUES('merge=A,B');

  176024. **

  176025. ** A and B are integers that decode to be the number of leaf pages

  176026. ** written for the merge, and the minimum number of segments on a level

  176027. ** before it will be selected for a merge, respectively.

  176028. */

  176029. static int fts3DoIncrmerge(

  176030.   Fts3Table *p,                   /* FTS3 table handle */

  176031.   const char *zParam              /* Nul-terminated string containing "A,B" */

  176032. ){

  176033.   int rc;

  176034.   int nMin = (FTS3_MERGE_COUNT / 2);

  176035.   int nMerge = 0;

  176036.   const char *z = zParam;

  176037. 

  176038.   /* Read the first integer value */

  176039.   nMerge = fts3Getint(&z);

  176040. 

  176041.   /* If the first integer value is followed by a ',',  read the second

  176042.   ** integer value. */

  176043.   if( z[0]==',' && z[1]!='\0' ){

  176044.     z++;

  176045.     nMin = fts3Getint(&z);

  176046.   }

  176047. 

  176048.   if( z[0]!='\0' || nMin<2 ){

  176049.     rc = SQLITE_ERROR;

  176050.   }else{

  176051.     rc = SQLITE_OK;

  176052.     if( !p->bHasStat ){

  176053.       assert( p->bFts4==0 );

  176054.       sqlite3Fts3CreateStatTable(&rc, p);

  176055.     }

  176056.     if( rc==SQLITE_OK ){

  176057.       rc = sqlite3Fts3Incrmerge(p, nMerge, nMin);

  176058.     }

  176059.     sqlite3Fts3SegmentsClose(p);

  176060.   }

  176061.   return rc;

  176062. }

  176063. 

  176064. /*

  176065. ** Process statements of the form:

  176066. **

  176067. **    INSERT INTO table(table) VALUES('automerge=X');

  176068. **

  176069. ** where X is an integer.  X==0 means to turn automerge off.  X!=0 means

  176070. ** turn it on.  The setting is persistent.

  176071. */

  176072. static int fts3DoAutoincrmerge(

  176073.   Fts3Table *p,                   /* FTS3 table handle */

  176074.   const char *zParam              /* Nul-terminated string containing boolean */

  176075. ){

  176076.   int rc = SQLITE_OK;

  176077.   sqlite3_stmt *pStmt = 0;

  176078.   p->nAutoincrmerge = fts3Getint(&zParam);

  176079.   if( p->nAutoincrmerge==1 || p->nAutoincrmerge>FTS3_MERGE_COUNT ){

  176080.     p->nAutoincrmerge = 8;

  176081.   }

  176082.   if( !p->bHasStat ){

  176083.     assert( p->bFts4==0 );

  176084.     sqlite3Fts3CreateStatTable(&rc, p);

  176085.     if( rc ) return rc;

  176086.   }

  176087.   rc = fts3SqlStmt(p, SQL_REPLACE_STAT, &pStmt, 0);

  176088.   if( rc ) return rc;

  176089.   sqlite3_bind_int(pStmt, 1, FTS_STAT_AUTOINCRMERGE);

  176090.   sqlite3_bind_int(pStmt, 2, p->nAutoincrmerge);

  176091.   sqlite3_step(pStmt);

  176092.   rc = sqlite3_reset(pStmt);

  176093.   return rc;

  176094. }

  176095. 

  176096. /*

  176097. ** Return a 64-bit checksum for the FTS index entry specified by the

  176098. ** arguments to this function.

  176099. */

  176100. static u64 fts3ChecksumEntry(

  176101.   const char *zTerm,              /* Pointer to buffer containing term */

  176102.   int nTerm,                      /* Size of zTerm in bytes */

  176103.   int iLangid,                    /* Language id for current row */

  176104.   int iIndex,                     /* Index (0..Fts3Table.nIndex-1) */

  176105.   i64 iDocid,                     /* Docid for current row. */

  176106.   int iCol,                       /* Column number */

  176107.   int iPos                        /* Position */

  176108. ){

  176109.   int i;

  176110.   u64 ret = (u64)iDocid;

  176111. 

  176112.   ret += (ret<<3) + iLangid;

  176113.   ret += (ret<<3) + iIndex;

  176114.   ret += (ret<<3) + iCol;

  176115.   ret += (ret<<3) + iPos;

  176116.   for(i=0; i<nTerm; i++) ret += (ret<<3) + zTerm[i];

  176117. 

  176118.   return ret;

  176119. }

  176120. 

  176121. /*

  176122. ** Return a checksum of all entries in the FTS index that correspond to

  176123. ** language id iLangid. The checksum is calculated by XORing the checksums

  176124. ** of each individual entry (see fts3ChecksumEntry()) together.

  176125. **

  176126. ** If successful, the checksum value is returned and *pRc set to SQLITE_OK.

  176127. ** Otherwise, if an error occurs, *pRc is set to an SQLite error code. The

  176128. ** return value is undefined in this case.

  176129. */

  176130. static u64 fts3ChecksumIndex(

  176131.   Fts3Table *p,                   /* FTS3 table handle */

  176132.   int iLangid,                    /* Language id to return cksum for */

  176133.   int iIndex,                     /* Index to cksum (0..p->nIndex-1) */

  176134.   int *pRc                        /* OUT: Return code */

  176135. ){

  176136.   Fts3SegFilter filter;

  176137.   Fts3MultiSegReader csr;

  176138.   int rc;

  176139.   u64 cksum = 0;

  176140. 

  176141.   assert( *pRc==SQLITE_OK );

  176142. 

  176143.   memset(&filter, 0, sizeof(filter));

  176144.   memset(&csr, 0, sizeof(csr));

  176145.   filter.flags =  FTS3_SEGMENT_REQUIRE_POS|FTS3_SEGMENT_IGNORE_EMPTY;

  176146.   filter.flags |= FTS3_SEGMENT_SCAN;

  176147. 

  176148.   rc = sqlite3Fts3SegReaderCursor(

  176149.       p, iLangid, iIndex, FTS3_SEGCURSOR_ALL, 0, 0, 0, 1,&csr

  176150.   );

  176151.   if( rc==SQLITE_OK ){

  176152.     rc = sqlite3Fts3SegReaderStart(p, &csr, &filter);

  176153.   }

  176154. 

  176155.   if( rc==SQLITE_OK ){

  176156.     while( SQLITE_ROW==(rc = sqlite3Fts3SegReaderStep(p, &csr)) ){

  176157.       char *pCsr = csr.aDoclist;

  176158.       char *pEnd = &pCsr[csr.nDoclist];

  176159. 

  176160.       i64 iDocid = 0;

  176161.       i64 iCol = 0;

  176162.       i64 iPos = 0;

  176163. 

  176164.       pCsr += sqlite3Fts3GetVarint(pCsr, &iDocid);

  176165.       while( pCsr<pEnd ){

  176166.         i64 iVal = 0;

  176167.         pCsr += sqlite3Fts3GetVarint(pCsr, &iVal);

  176168.         if( pCsr<pEnd ){

  176169.           if( iVal==0 || iVal==1 ){

  176170.             iCol = 0;

  176171.             iPos = 0;

  176172.             if( iVal ){

  176173.               pCsr += sqlite3Fts3GetVarint(pCsr, &iCol);

  176174.             }else{

  176175.               pCsr += sqlite3Fts3GetVarint(pCsr, &iVal);

  176176.               iDocid += iVal;

  176177.             }

  176178.           }else{

  176179.             iPos += (iVal - 2);

  176180.             cksum = cksum ^ fts3ChecksumEntry(

  176181.                 csr.zTerm, csr.nTerm, iLangid, iIndex, iDocid,

  176182.                 (int)iCol, (int)iPos

  176183.             );

  176184.           }

  176185.         }

  176186.       }

  176187.     }

  176188.   }

  176189.   sqlite3Fts3SegReaderFinish(&csr);

  176190. 

  176191.   *pRc = rc;

  176192.   return cksum;

  176193. }

  176194. 

  176195. /*

  176196. ** Check if the contents of the FTS index match the current contents of the

  176197. ** content table. If no error occurs and the contents do match, set *pbOk

  176198. ** to true and return SQLITE_OK. Or if the contents do not match, set *pbOk

  176199. ** to false before returning.

  176200. **

  176201. ** If an error occurs (e.g. an OOM or IO error), return an SQLite error 

  176202. ** code. The final value of *pbOk is undefined in this case.

  176203. */

  176204. static int fts3IntegrityCheck(Fts3Table *p, int *pbOk){

  176205.   int rc = SQLITE_OK;             /* Return code */

  176206.   u64 cksum1 = 0;                 /* Checksum based on FTS index contents */

  176207.   u64 cksum2 = 0;                 /* Checksum based on %_content contents */

  176208.   sqlite3_stmt *pAllLangid = 0;   /* Statement to return all language-ids */

  176209. 

  176210.   /* This block calculates the checksum according to the FTS index. */

  176211.   rc = fts3SqlStmt(p, SQL_SELECT_ALL_LANGID, &pAllLangid, 0);

  176212.   if( rc==SQLITE_OK ){

  176213.     int rc2;

  176214.     sqlite3_bind_int(pAllLangid, 1, p->iPrevLangid);

  176215.     sqlite3_bind_int(pAllLangid, 2, p->nIndex);

  176216.     while( rc==SQLITE_OK && sqlite3_step(pAllLangid)==SQLITE_ROW ){

  176217.       int iLangid = sqlite3_column_int(pAllLangid, 0);

  176218.       int i;

  176219.       for(i=0; i<p->nIndex; i++){

  176220.         cksum1 = cksum1 ^ fts3ChecksumIndex(p, iLangid, i, &rc);

  176221.       }

  176222.     }

  176223.     rc2 = sqlite3_reset(pAllLangid);

  176224.     if( rc==SQLITE_OK ) rc = rc2;

  176225.   }

  176226. 

  176227.   /* This block calculates the checksum according to the %_content table */

  176228.   if( rc==SQLITE_OK ){

  176229.     sqlite3_tokenizer_module const *pModule = p->pTokenizer->pModule;

  176230.     sqlite3_stmt *pStmt = 0;

  176231.     char *zSql;

  176232.    

  176233.     zSql = sqlite3_mprintf("SELECT %s" , p->zReadExprlist);

  176234.     if( !zSql ){

  176235.       rc = SQLITE_NOMEM;

  176236.     }else{

  176237.       rc = sqlite3_prepare_v2(p->db, zSql, -1, &pStmt, 0);

  176238.       sqlite3_free(zSql);

  176239.     }

  176240. 

  176241.     while( rc==SQLITE_OK && SQLITE_ROW==sqlite3_step(pStmt) ){

  176242.       i64 iDocid = sqlite3_column_int64(pStmt, 0);

  176243.       int iLang = langidFromSelect(p, pStmt);

  176244.       int iCol;

  176245. 

  176246.       for(iCol=0; rc==SQLITE_OK && iCol<p->nColumn; iCol++){

  176247.         if( p->abNotindexed[iCol]==0 ){

  176248.           const char *zText = (const char *)sqlite3_column_text(pStmt, iCol+1);

  176249.           int nText = sqlite3_column_bytes(pStmt, iCol+1);

  176250.           sqlite3_tokenizer_cursor *pT = 0;

  176251. 

  176252.           rc = sqlite3Fts3OpenTokenizer(p->pTokenizer, iLang, zText, nText,&pT);

  176253.           while( rc==SQLITE_OK ){

  176254.             char const *zToken;       /* Buffer containing token */

  176255.             int nToken = 0;           /* Number of bytes in token */

  176256.             int iDum1 = 0, iDum2 = 0; /* Dummy variables */

  176257.             int iPos = 0;             /* Position of token in zText */

  176258. 

  176259.             rc = pModule->xNext(pT, &zToken, &nToken, &iDum1, &iDum2, &iPos);

  176260.             if( rc==SQLITE_OK ){

  176261.               int i;

  176262.               cksum2 = cksum2 ^ fts3ChecksumEntry(

  176263.                   zToken, nToken, iLang, 0, iDocid, iCol, iPos

  176264.               );

  176265.               for(i=1; i<p->nIndex; i++){

  176266.                 if( p->aIndex[i].nPrefix<=nToken ){

  176267.                   cksum2 = cksum2 ^ fts3ChecksumEntry(

  176268.                       zToken, p->aIndex[i].nPrefix, iLang, i, iDocid, iCol, iPos

  176269.                   );

  176270.                 }

  176271.               }

  176272.             }

  176273.           }

  176274.           if( pT ) pModule->xClose(pT);

  176275.           if( rc==SQLITE_DONE ) rc = SQLITE_OK;

  176276.         }

  176277.       }

  176278.     }

  176279. 

  176280.     sqlite3_finalize(pStmt);

  176281.   }

  176282. 

  176283.   *pbOk = (cksum1==cksum2);

  176284.   return rc;

  176285. }

  176286. 

  176287. /*

  176288. ** Run the integrity-check. If no error occurs and the current contents of

  176289. ** the FTS index are correct, return SQLITE_OK. Or, if the contents of the

  176290. ** FTS index are incorrect, return SQLITE_CORRUPT_VTAB.

  176291. **

  176292. ** Or, if an error (e.g. an OOM or IO error) occurs, return an SQLite 

  176293. ** error code.

  176294. **

  176295. ** The integrity-check works as follows. For each token and indexed token

  176296. ** prefix in the document set, a 64-bit checksum is calculated (by code

  176297. ** in fts3ChecksumEntry()) based on the following:

  176298. **

  176299. **     + The index number (0 for the main index, 1 for the first prefix

  176300. **       index etc.),

  176301. **     + The token (or token prefix) text itself, 

  176302. **     + The language-id of the row it appears in,

  176303. **     + The docid of the row it appears in,

  176304. **     + The column it appears in, and

  176305. **     + The tokens position within that column.

  176306. **

  176307. ** The checksums for all entries in the index are XORed together to create

  176308. ** a single checksum for the entire index.

  176309. **

  176310. ** The integrity-check code calculates the same checksum in two ways:

  176311. **

  176312. **     1. By scanning the contents of the FTS index, and 

  176313. **     2. By scanning and tokenizing the content table.

  176314. **

  176315. ** If the two checksums are identical, the integrity-check is deemed to have

  176316. ** passed.

  176317. */

  176318. static int fts3DoIntegrityCheck(

  176319.   Fts3Table *p                    /* FTS3 table handle */

  176320. ){

  176321.   int rc;

  176322.   int bOk = 0;

  176323.   rc = fts3IntegrityCheck(p, &bOk);

  176324.   if( rc==SQLITE_OK && bOk==0 ) rc = FTS_CORRUPT_VTAB;

  176325.   return rc;

  176326. }

  176327. 

  176328. /*

  176329. ** Handle a 'special' INSERT of the form:

  176330. **

  176331. **   "INSERT INTO tbl(tbl) VALUES(<expr>)"

  176332. **

  176333. ** Argument pVal contains the result of <expr>. Currently the only 

  176334. ** meaningful value to insert is the text 'optimize'.

  176335. */

  176336. static int fts3SpecialInsert(Fts3Table *p, sqlite3_value *pVal){

  176337.   int rc;                         /* Return Code */

  176338.   const char *zVal = (const char *)sqlite3_value_text(pVal);

  176339.   int nVal = sqlite3_value_bytes(pVal);

  176340. 

  176341.   if( !zVal ){

  176342.     return SQLITE_NOMEM;

  176343.   }else if( nVal==8 && 0==sqlite3_strnicmp(zVal, "optimize", 8) ){

  176344.     rc = fts3DoOptimize(p, 0);

  176345.   }else if( nVal==7 && 0==sqlite3_strnicmp(zVal, "rebuild", 7) ){

  176346.     rc = fts3DoRebuild(p);

  176347.   }else if( nVal==15 && 0==sqlite3_strnicmp(zVal, "integrity-check", 15) ){

  176348.     rc = fts3DoIntegrityCheck(p);

  176349.   }else if( nVal>6 && 0==sqlite3_strnicmp(zVal, "merge=", 6) ){

  176350.     rc = fts3DoIncrmerge(p, &zVal[6]);

  176351.   }else if( nVal>10 && 0==sqlite3_strnicmp(zVal, "automerge=", 10) ){

  176352.     rc = fts3DoAutoincrmerge(p, &zVal[10]);

  176353. #ifdef SQLITE_TEST

  176354.   }else if( nVal>9 && 0==sqlite3_strnicmp(zVal, "nodesize=", 9) ){

  176355.     p->nNodeSize = atoi(&zVal[9]);

  176356.     rc = SQLITE_OK;

  176357.   }else if( nVal>11 && 0==sqlite3_strnicmp(zVal, "maxpending=", 9) ){

  176358.     p->nMaxPendingData = atoi(&zVal[11]);

  176359.     rc = SQLITE_OK;

  176360.   }else if( nVal>21 && 0==sqlite3_strnicmp(zVal, "test-no-incr-doclist=", 21) ){

  176361.     p->bNoIncrDoclist = atoi(&zVal[21]);

  176362.     rc = SQLITE_OK;

  176363. #endif

  176364.   }else{

  176365.     rc = SQLITE_ERROR;

  176366.   }

  176367. 

  176368.   return rc;

  176369. }

  176370. 

  176371. #ifndef SQLITE_DISABLE_FTS4_DEFERRED

  176372. /*

  176373. ** Delete all cached deferred doclists. Deferred doclists are cached

  176374. ** (allocated) by the sqlite3Fts3CacheDeferredDoclists() function.

  176375. */

  176376. SQLITE_PRIVATE void sqlite3Fts3FreeDeferredDoclists(Fts3Cursor *pCsr){

  176377.   Fts3DeferredToken *pDef;

  176378.   for(pDef=pCsr->pDeferred; pDef; pDef=pDef->pNext){

  176379.     fts3PendingListDelete(pDef->pList);

  176380.     pDef->pList = 0;

  176381.   }

  176382. }

  176383. 

  176384. /*

  176385. ** Free all entries in the pCsr->pDeffered list. Entries are added to 

  176386. ** this list using sqlite3Fts3DeferToken().

  176387. */

  176388. SQLITE_PRIVATE void sqlite3Fts3FreeDeferredTokens(Fts3Cursor *pCsr){

  176389.   Fts3DeferredToken *pDef;

  176390.   Fts3DeferredToken *pNext;

  176391.   for(pDef=pCsr->pDeferred; pDef; pDef=pNext){

  176392.     pNext = pDef->pNext;

  176393.     fts3PendingListDelete(pDef->pList);

  176394.     sqlite3_free(pDef);

  176395.   }

  176396.   pCsr->pDeferred = 0;

  176397. }

  176398. 

  176399. /*

  176400. ** Generate deferred-doclists for all tokens in the pCsr->pDeferred list

  176401. ** based on the row that pCsr currently points to.

  176402. **

  176403. ** A deferred-doclist is like any other doclist with position information

  176404. ** included, except that it only contains entries for a single row of the

  176405. ** table, not for all rows.

  176406. */

  176407. SQLITE_PRIVATE int sqlite3Fts3CacheDeferredDoclists(Fts3Cursor *pCsr){

  176408.   int rc = SQLITE_OK;             /* Return code */

  176409.   if( pCsr->pDeferred ){

  176410.     int i;                        /* Used to iterate through table columns */

  176411.     sqlite3_int64 iDocid;         /* Docid of the row pCsr points to */

  176412.     Fts3DeferredToken *pDef;      /* Used to iterate through deferred tokens */

  176413.   

  176414.     Fts3Table *p = (Fts3Table *)pCsr->base.pVtab;

  176415.     sqlite3_tokenizer *pT = p->pTokenizer;

  176416.     sqlite3_tokenizer_module const *pModule = pT->pModule;

  176417.    

  176418.     assert( pCsr->isRequireSeek==0 );

  176419.     iDocid = sqlite3_column_int64(pCsr->pStmt, 0);

  176420.   

  176421.     for(i=0; i<p->nColumn && rc==SQLITE_OK; i++){

  176422.       if( p->abNotindexed[i]==0 ){

  176423.         const char *zText = (const char *)sqlite3_column_text(pCsr->pStmt, i+1);

  176424.         sqlite3_tokenizer_cursor *pTC = 0;

  176425. 

  176426.         rc = sqlite3Fts3OpenTokenizer(pT, pCsr->iLangid, zText, -1, &pTC);

  176427.         while( rc==SQLITE_OK ){

  176428.           char const *zToken;       /* Buffer containing token */

  176429.           int nToken = 0;           /* Number of bytes in token */

  176430.           int iDum1 = 0, iDum2 = 0; /* Dummy variables */

  176431.           int iPos = 0;             /* Position of token in zText */

  176432. 

  176433.           rc = pModule->xNext(pTC, &zToken, &nToken, &iDum1, &iDum2, &iPos);

  176434.           for(pDef=pCsr->pDeferred; pDef && rc==SQLITE_OK; pDef=pDef->pNext){

  176435.             Fts3PhraseToken *pPT = pDef->pToken;

  176436.             if( (pDef->iCol>=p->nColumn || pDef->iCol==i)

  176437.                 && (pPT->bFirst==0 || iPos==0)

  176438.                 && (pPT->n==nToken || (pPT->isPrefix && pPT->n<nToken))

  176439.                 && (0==memcmp(zToken, pPT->z, pPT->n))

  176440.               ){

  176441.               fts3PendingListAppend(&pDef->pList, iDocid, i, iPos, &rc);

  176442.             }

  176443.           }

  176444.         }

  176445.         if( pTC ) pModule->xClose(pTC);

  176446.         if( rc==SQLITE_DONE ) rc = SQLITE_OK;

  176447.       }

  176448.     }

  176449. 

  176450.     for(pDef=pCsr->pDeferred; pDef && rc==SQLITE_OK; pDef=pDef->pNext){

  176451.       if( pDef->pList ){

  176452.         rc = fts3PendingListAppendVarint(&pDef->pList, 0);

  176453.       }

  176454.     }

  176455.   }

  176456. 

  176457.   return rc;

  176458. }

  176459. 

  176460. SQLITE_PRIVATE int sqlite3Fts3DeferredTokenList(

  176461.   Fts3DeferredToken *p, 

  176462.   char **ppData, 

  176463.   int *pnData

  176464. ){

  176465.   char *pRet;

  176466.   int nSkip;

  176467.   sqlite3_int64 dummy;

  176468. 

  176469.   *ppData = 0;

  176470.   *pnData = 0;

  176471. 

  176472.   if( p->pList==0 ){

  176473.     return SQLITE_OK;

  176474.   }

  176475. 

  176476.   pRet = (char *)sqlite3_malloc(p->pList->nData);

  176477.   if( !pRet ) return SQLITE_NOMEM;

  176478. 

  176479.   nSkip = sqlite3Fts3GetVarint(p->pList->aData, &dummy);

  176480.   *pnData = p->pList->nData - nSkip;

  176481.   *ppData = pRet;

  176482.   

  176483.   memcpy(pRet, &p->pList->aData[nSkip], *pnData);

  176484.   return SQLITE_OK;

  176485. }

  176486. 

  176487. /*

  176488. ** Add an entry for token pToken to the pCsr->pDeferred list.

  176489. */

  176490. SQLITE_PRIVATE int sqlite3Fts3DeferToken(

  176491.   Fts3Cursor *pCsr,               /* Fts3 table cursor */

  176492.   Fts3PhraseToken *pToken,        /* Token to defer */

  176493.   int iCol                        /* Column that token must appear in (or -1) */

  176494. ){

  176495.   Fts3DeferredToken *pDeferred;

  176496.   pDeferred = sqlite3_malloc(sizeof(*pDeferred));

  176497.   if( !pDeferred ){

  176498.     return SQLITE_NOMEM;

  176499.   }

  176500.   memset(pDeferred, 0, sizeof(*pDeferred));

  176501.   pDeferred->pToken = pToken;

  176502.   pDeferred->pNext = pCsr->pDeferred; 

  176503.   pDeferred->iCol = iCol;

  176504.   pCsr->pDeferred = pDeferred;

  176505. 

  176506.   assert( pToken->pDeferred==0 );

  176507.   pToken->pDeferred = pDeferred;

  176508. 

  176509.   return SQLITE_OK;

  176510. }

  176511. #endif

  176512. 

  176513. /*

  176514. ** SQLite value pRowid contains the rowid of a row that may or may not be

  176515. ** present in the FTS3 table. If it is, delete it and adjust the contents

  176516. ** of subsiduary data structures accordingly.

  176517. */

  176518. static int fts3DeleteByRowid(

  176519.   Fts3Table *p, 

  176520.   sqlite3_value *pRowid, 

  176521.   int *pnChng,                    /* IN/OUT: Decrement if row is deleted */

  176522.   u32 *aSzDel

  176523. ){

  176524.   int rc = SQLITE_OK;             /* Return code */

  176525.   int bFound = 0;                 /* True if *pRowid really is in the table */

  176526. 

  176527.   fts3DeleteTerms(&rc, p, pRowid, aSzDel, &bFound);

  176528.   if( bFound && rc==SQLITE_OK ){

  176529.     int isEmpty = 0;              /* Deleting *pRowid leaves the table empty */

  176530.     rc = fts3IsEmpty(p, pRowid, &isEmpty);

  176531.     if( rc==SQLITE_OK ){

  176532.       if( isEmpty ){

  176533.         /* Deleting this row means the whole table is empty. In this case

  176534.         ** delete the contents of all three tables and throw away any

  176535.         ** data in the pendingTerms hash table.  */

  176536.         rc = fts3DeleteAll(p, 1);

  176537.         *pnChng = 0;

  176538.         memset(aSzDel, 0, sizeof(u32) * (p->nColumn+1) * 2);

  176539.       }else{

  176540.         *pnChng = *pnChng - 1;

  176541.         if( p->zContentTbl==0 ){

  176542.           fts3SqlExec(&rc, p, SQL_DELETE_CONTENT, &pRowid);

  176543.         }

  176544.         if( p->bHasDocsize ){

  176545.           fts3SqlExec(&rc, p, SQL_DELETE_DOCSIZE, &pRowid);

  176546.         }

  176547.       }

  176548.     }

  176549.   }

  176550. 

  176551.   return rc;

  176552. }

  176553. 

  176554. /*

  176555. ** This function does the work for the xUpdate method of FTS3 virtual

  176556. ** tables. The schema of the virtual table being:

  176557. **

  176558. **     CREATE TABLE <table name>( 

  176559. **       <user columns>,

  176560. **       <table name> HIDDEN, 

  176561. **       docid HIDDEN, 

  176562. **       <langid> HIDDEN

  176563. **     );

  176564. **

  176565. ** 

  176566. */

  176567. SQLITE_PRIVATE int sqlite3Fts3UpdateMethod(

  176568.   sqlite3_vtab *pVtab,            /* FTS3 vtab object */

  176569.   int nArg,                       /* Size of argument array */

  176570.   sqlite3_value **apVal,          /* Array of arguments */

  176571.   sqlite_int64 *pRowid            /* OUT: The affected (or effected) rowid */

  176572. ){

  176573.   Fts3Table *p = (Fts3Table *)pVtab;

  176574.   int rc = SQLITE_OK;             /* Return Code */

  176575.   u32 *aSzIns = 0;                /* Sizes of inserted documents */

  176576.   u32 *aSzDel = 0;                /* Sizes of deleted documents */

  176577.   int nChng = 0;                  /* Net change in number of documents */

  176578.   int bInsertDone = 0;

  176579. 

  176580.   /* At this point it must be known if the %_stat table exists or not.

  176581.   ** So bHasStat may not be 2.  */

  176582.   assert( p->bHasStat==0 || p->bHasStat==1 );

  176583. 

  176584.   assert( p->pSegments==0 );

  176585.   assert( 

  176586.       nArg==1                     /* DELETE operations */

  176587.    || nArg==(2 + p->nColumn + 3)  /* INSERT or UPDATE operations */

  176588.   );

  176589. 

  176590.   /* Check for a "special" INSERT operation. One of the form:

  176591.   **

  176592.   **   INSERT INTO xyz(xyz) VALUES('command');

  176593.   */

  176594.   if( nArg>1 

  176595.    && sqlite3_value_type(apVal[0])==SQLITE_NULL 

  176596.    && sqlite3_value_type(apVal[p->nColumn+2])!=SQLITE_NULL 

  176597.   ){

  176598.     rc = fts3SpecialInsert(p, apVal[p->nColumn+2]);

  176599.     goto update_out;

  176600.   }

  176601. 

  176602.   if( nArg>1 && sqlite3_value_int(apVal[2 + p->nColumn + 2])<0 ){

  176603.     rc = SQLITE_CONSTRAINT;

  176604.     goto update_out;

  176605.   }

  176606. 

  176607.   /* Allocate space to hold the change in document sizes */

  176608.   aSzDel = sqlite3_malloc64(sizeof(aSzDel[0])*((sqlite3_int64)p->nColumn+1)*2);

  176609.   if( aSzDel==0 ){

  176610.     rc = SQLITE_NOMEM;

  176611.     goto update_out;

  176612.   }

  176613.   aSzIns = &aSzDel[p->nColumn+1];

  176614.   memset(aSzDel, 0, sizeof(aSzDel[0])*(p->nColumn+1)*2);

  176615. 

  176616.   rc = fts3Writelock(p);

  176617.   if( rc!=SQLITE_OK ) goto update_out;

  176618. 

  176619.   /* If this is an INSERT operation, or an UPDATE that modifies the rowid

  176620.   ** value, then this operation requires constraint handling.

  176621.   **

  176622.   ** If the on-conflict mode is REPLACE, this means that the existing row

  176623.   ** should be deleted from the database before inserting the new row. Or,

  176624.   ** if the on-conflict mode is other than REPLACE, then this method must

  176625.   ** detect the conflict and return SQLITE_CONSTRAINT before beginning to

  176626.   ** modify the database file.

  176627.   */

  176628.   if( nArg>1 && p->zContentTbl==0 ){

  176629.     /* Find the value object that holds the new rowid value. */

  176630.     sqlite3_value *pNewRowid = apVal[3+p->nColumn];

  176631.     if( sqlite3_value_type(pNewRowid)==SQLITE_NULL ){

  176632.       pNewRowid = apVal[1];

  176633.     }

  176634. 

  176635.     if( sqlite3_value_type(pNewRowid)!=SQLITE_NULL && ( 

  176636.         sqlite3_value_type(apVal[0])==SQLITE_NULL

  176637.      || sqlite3_value_int64(apVal[0])!=sqlite3_value_int64(pNewRowid)

  176638.     )){

  176639.       /* The new rowid is not NULL (in this case the rowid will be

  176640.       ** automatically assigned and there is no chance of a conflict), and 

  176641.       ** the statement is either an INSERT or an UPDATE that modifies the

  176642.       ** rowid column. So if the conflict mode is REPLACE, then delete any

  176643.       ** existing row with rowid=pNewRowid. 

  176644.       **

  176645.       ** Or, if the conflict mode is not REPLACE, insert the new record into 

  176646.       ** the %_content table. If we hit the duplicate rowid constraint (or any

  176647.       ** other error) while doing so, return immediately.

  176648.       **

  176649.       ** This branch may also run if pNewRowid contains a value that cannot

  176650.       ** be losslessly converted to an integer. In this case, the eventual 

  176651.       ** call to fts3InsertData() (either just below or further on in this

  176652.       ** function) will return SQLITE_MISMATCH. If fts3DeleteByRowid is 

  176653.       ** invoked, it will delete zero rows (since no row will have

  176654.       ** docid=$pNewRowid if $pNewRowid is not an integer value).

  176655.       */

  176656.       if( sqlite3_vtab_on_conflict(p->db)==SQLITE_REPLACE ){

  176657.         rc = fts3DeleteByRowid(p, pNewRowid, &nChng, aSzDel);

  176658.       }else{

  176659.         rc = fts3InsertData(p, apVal, pRowid);

  176660.         bInsertDone = 1;

  176661.       }

  176662.     }

  176663.   }

  176664.   if( rc!=SQLITE_OK ){

  176665.     goto update_out;

  176666.   }

  176667. 

  176668.   /* If this is a DELETE or UPDATE operation, remove the old record. */

  176669.   if( sqlite3_value_type(apVal[0])!=SQLITE_NULL ){

  176670.     assert( sqlite3_value_type(apVal[0])==SQLITE_INTEGER );

  176671.     rc = fts3DeleteByRowid(p, apVal[0], &nChng, aSzDel);

  176672.   }

  176673.   

  176674.   /* If this is an INSERT or UPDATE operation, insert the new record. */

  176675.   if( nArg>1 && rc==SQLITE_OK ){

  176676.     int iLangid = sqlite3_value_int(apVal[2 + p->nColumn + 2]);

  176677.     if( bInsertDone==0 ){

  176678.       rc = fts3InsertData(p, apVal, pRowid);

  176679.       if( rc==SQLITE_CONSTRAINT && p->zContentTbl==0 ){

  176680.         rc = FTS_CORRUPT_VTAB;

  176681.       }

  176682.     }

  176683.     if( rc==SQLITE_OK ){

  176684.       rc = fts3PendingTermsDocid(p, 0, iLangid, *pRowid);

  176685.     }

  176686.     if( rc==SQLITE_OK ){

  176687.       assert( p->iPrevDocid==*pRowid );

  176688.       rc = fts3InsertTerms(p, iLangid, apVal, aSzIns);

  176689.     }

  176690.     if( p->bHasDocsize ){

  176691.       fts3InsertDocsize(&rc, p, aSzIns);

  176692.     }

  176693.     nChng++;

  176694.   }

  176695. 

  176696.   if( p->bFts4 ){

  176697.     fts3UpdateDocTotals(&rc, p, aSzIns, aSzDel, nChng);

  176698.   }

  176699. 

  176700.  update_out:

  176701.   sqlite3_free(aSzDel);

  176702.   sqlite3Fts3SegmentsClose(p);

  176703.   return rc;

  176704. }

  176705. 

  176706. /* 

  176707. ** Flush any data in the pending-terms hash table to disk. If successful,

  176708. ** merge all segments in the database (including the new segment, if 

  176709. ** there was any data to flush) into a single segment. 

  176710. */

  176711. SQLITE_PRIVATE int sqlite3Fts3Optimize(Fts3Table *p){

  176712.   int rc;

  176713.   rc = sqlite3_exec(p->db, "SAVEPOINT fts3", 0, 0, 0);

  176714.   if( rc==SQLITE_OK ){

  176715.     rc = fts3DoOptimize(p, 1);

  176716.     if( rc==SQLITE_OK || rc==SQLITE_DONE ){

  176717.       int rc2 = sqlite3_exec(p->db, "RELEASE fts3", 0, 0, 0);

  176718.       if( rc2!=SQLITE_OK ) rc = rc2;

  176719.     }else{

  176720.       sqlite3_exec(p->db, "ROLLBACK TO fts3", 0, 0, 0);

  176721.       sqlite3_exec(p->db, "RELEASE fts3", 0, 0, 0);

  176722.     }

  176723.   }

  176724.   sqlite3Fts3SegmentsClose(p);

  176725.   return rc;

  176726. }

  176727. 

  176728. #endif

  176729. 

  176730. /************** End of fts3_write.c ******************************************/

  176731. /************** Begin file fts3_snippet.c ************************************/

  176732. /*

  176733. ** 2009 Oct 23

  176734. **

  176735. ** The author disclaims copyright to this source code.  In place of

  176736. ** a legal notice, here is a blessing:

  176737. **

  176738. **    May you do good and not evil.

  176739. **    May you find forgiveness for yourself and forgive others.

  176740. **    May you share freely, never taking more than you give.

  176741. **

  176742. ******************************************************************************

  176743. */

  176744. 

  176745. /* #include "fts3Int.h" */

  176746. #if !defined(SQLITE_CORE) || defined(SQLITE_ENABLE_FTS3)

  176747. 

  176748. /* #include <string.h> */

  176749. /* #include <assert.h> */

  176750. 

  176751. /*

  176752. ** Characters that may appear in the second argument to matchinfo().

  176753. */

  176754. #define FTS3_MATCHINFO_NPHRASE   'p'        /* 1 value */

  176755. #define FTS3_MATCHINFO_NCOL      'c'        /* 1 value */

  176756. #define FTS3_MATCHINFO_NDOC      'n'        /* 1 value */

  176757. #define FTS3_MATCHINFO_AVGLENGTH 'a'        /* nCol values */

  176758. #define FTS3_MATCHINFO_LENGTH    'l'        /* nCol values */

  176759. #define FTS3_MATCHINFO_LCS       's'        /* nCol values */

  176760. #define FTS3_MATCHINFO_HITS      'x'        /* 3*nCol*nPhrase values */

  176761. #define FTS3_MATCHINFO_LHITS     'y'        /* nCol*nPhrase values */

  176762. #define FTS3_MATCHINFO_LHITS_BM  'b'        /* nCol*nPhrase values */

  176763. 

  176764. /*

  176765. ** The default value for the second argument to matchinfo(). 

  176766. */

  176767. #define FTS3_MATCHINFO_DEFAULT   "pcx"

  176768. 

  176769. 

  176770. /*

  176771. ** Used as an fts3ExprIterate() context when loading phrase doclists to

  176772. ** Fts3Expr.aDoclist[]/nDoclist.

  176773. */

  176774. typedef struct LoadDoclistCtx LoadDoclistCtx;

  176775. struct LoadDoclistCtx {

  176776.   Fts3Cursor *pCsr;               /* FTS3 Cursor */

  176777.   int nPhrase;                    /* Number of phrases seen so far */

  176778.   int nToken;                     /* Number of tokens seen so far */

  176779. };

  176780. 

  176781. /*

  176782. ** The following types are used as part of the implementation of the 

  176783. ** fts3BestSnippet() routine.

  176784. */

  176785. typedef struct SnippetIter SnippetIter;

  176786. typedef struct SnippetPhrase SnippetPhrase;

  176787. typedef struct SnippetFragment SnippetFragment;

  176788. 

  176789. struct SnippetIter {

  176790.   Fts3Cursor *pCsr;               /* Cursor snippet is being generated from */

  176791.   int iCol;                       /* Extract snippet from this column */

  176792.   int nSnippet;                   /* Requested snippet length (in tokens) */

  176793.   int nPhrase;                    /* Number of phrases in query */

  176794.   SnippetPhrase *aPhrase;         /* Array of size nPhrase */

  176795.   int iCurrent;                   /* First token of current snippet */

  176796. };

  176797. 

  176798. struct SnippetPhrase {

  176799.   int nToken;                     /* Number of tokens in phrase */

  176800.   char *pList;                    /* Pointer to start of phrase position list */

  176801.   int iHead;                      /* Next value in position list */

  176802.   char *pHead;                    /* Position list data following iHead */

  176803.   int iTail;                      /* Next value in trailing position list */

  176804.   char *pTail;                    /* Position list data following iTail */

  176805. };

  176806. 

  176807. struct SnippetFragment {

  176808.   int iCol;                       /* Column snippet is extracted from */

  176809.   int iPos;                       /* Index of first token in snippet */

  176810.   u64 covered;                    /* Mask of query phrases covered */

  176811.   u64 hlmask;                     /* Mask of snippet terms to highlight */

  176812. };

  176813. 

  176814. /*

  176815. ** This type is used as an fts3ExprIterate() context object while 

  176816. ** accumulating the data returned by the matchinfo() function.

  176817. */

  176818. typedef struct MatchInfo MatchInfo;

  176819. struct MatchInfo {

  176820.   Fts3Cursor *pCursor;            /* FTS3 Cursor */

  176821.   int nCol;                       /* Number of columns in table */

  176822.   int nPhrase;                    /* Number of matchable phrases in query */

  176823.   sqlite3_int64 nDoc;             /* Number of docs in database */

  176824.   char flag;

  176825.   u32 *aMatchinfo;                /* Pre-allocated buffer */

  176826. };

  176827. 

  176828. /*

  176829. ** An instance of this structure is used to manage a pair of buffers, each

  176830. ** (nElem * sizeof(u32)) bytes in size. See the MatchinfoBuffer code below

  176831. ** for details.

  176832. */

  176833. struct MatchinfoBuffer {

  176834.   u8 aRef[3];

  176835.   int nElem;

  176836.   int bGlobal;                    /* Set if global data is loaded */

  176837.   char *zMatchinfo;

  176838.   u32 aMatchinfo[1];

  176839. };

  176840. 

  176841. 

  176842. /*

  176843. ** The snippet() and offsets() functions both return text values. An instance

  176844. ** of the following structure is used to accumulate those values while the

  176845. ** functions are running. See fts3StringAppend() for details.

  176846. */

  176847. typedef struct StrBuffer StrBuffer;

  176848. struct StrBuffer {

  176849.   char *z;                        /* Pointer to buffer containing string */

  176850.   int n;                          /* Length of z in bytes (excl. nul-term) */

  176851.   int nAlloc;                     /* Allocated size of buffer z in bytes */

  176852. };

  176853. 

  176854. 

  176855. /*************************************************************************

  176856. ** Start of MatchinfoBuffer code.

  176857. */

  176858. 

  176859. /*

  176860. ** Allocate a two-slot MatchinfoBuffer object.

  176861. */

  176862. static MatchinfoBuffer *fts3MIBufferNew(size_t nElem, const char *zMatchinfo){

  176863.   MatchinfoBuffer *pRet;

  176864.   sqlite3_int64 nByte = sizeof(u32) * (2*(sqlite3_int64)nElem + 1)

  176865.                            + sizeof(MatchinfoBuffer);

  176866.   sqlite3_int64 nStr = strlen(zMatchinfo);

  176867. 

  176868.   pRet = sqlite3_malloc64(nByte + nStr+1);

  176869.   if( pRet ){

  176870.     memset(pRet, 0, nByte);

  176871.     pRet->aMatchinfo[0] = (u8*)(&pRet->aMatchinfo[1]) - (u8*)pRet;

  176872.     pRet->aMatchinfo[1+nElem] = pRet->aMatchinfo[0]

  176873.                                       + sizeof(u32)*((int)nElem+1);

  176874.     pRet->nElem = (int)nElem;

  176875.     pRet->zMatchinfo = ((char*)pRet) + nByte;

  176876.     memcpy(pRet->zMatchinfo, zMatchinfo, nStr+1);

  176877.     pRet->aRef[0] = 1;

  176878.   }

  176879. 

  176880.   return pRet;

  176881. }

  176882. 

  176883. static void fts3MIBufferFree(void *p){

  176884.   MatchinfoBuffer *pBuf = (MatchinfoBuffer*)((u8*)p - ((u32*)p)[-1]);

  176885. 

  176886.   assert( (u32*)p==&pBuf->aMatchinfo[1] 

  176887.        || (u32*)p==&pBuf->aMatchinfo[pBuf->nElem+2] 

  176888.   );

  176889.   if( (u32*)p==&pBuf->aMatchinfo[1] ){

  176890.     pBuf->aRef[1] = 0;

  176891.   }else{

  176892.     pBuf->aRef[2] = 0;

  176893.   }

  176894. 

  176895.   if( pBuf->aRef[0]==0 && pBuf->aRef[1]==0 && pBuf->aRef[2]==0 ){

  176896.     sqlite3_free(pBuf);

  176897.   }

  176898. }

  176899. 

  176900. static void (*fts3MIBufferAlloc(MatchinfoBuffer *p, u32 **paOut))(void*){

  176901.   void (*xRet)(void*) = 0;

  176902.   u32 *aOut = 0;

  176903. 

  176904.   if( p->aRef[1]==0 ){

  176905.     p->aRef[1] = 1;

  176906.     aOut = &p->aMatchinfo[1];

  176907.     xRet = fts3MIBufferFree;

  176908.   }

  176909.   else if( p->aRef[2]==0 ){

  176910.     p->aRef[2] = 1;

  176911.     aOut = &p->aMatchinfo[p->nElem+2];

  176912.     xRet = fts3MIBufferFree;

  176913.   }else{

  176914.     aOut = (u32*)sqlite3_malloc64(p->nElem * sizeof(u32));

  176915.     if( aOut ){

  176916.       xRet = sqlite3_free;

  176917.       if( p->bGlobal ) memcpy(aOut, &p->aMatchinfo[1], p->nElem*sizeof(u32));

  176918.     }

  176919.   }

  176920. 

  176921.   *paOut = aOut;

  176922.   return xRet;

  176923. }

  176924. 

  176925. static void fts3MIBufferSetGlobal(MatchinfoBuffer *p){

  176926.   p->bGlobal = 1;

  176927.   memcpy(&p->aMatchinfo[2+p->nElem], &p->aMatchinfo[1], p->nElem*sizeof(u32));

  176928. }

  176929. 

  176930. /*

  176931. ** Free a MatchinfoBuffer object allocated using fts3MIBufferNew()

  176932. */

  176933. SQLITE_PRIVATE void sqlite3Fts3MIBufferFree(MatchinfoBuffer *p){

  176934.   if( p ){

  176935.     assert( p->aRef[0]==1 );

  176936.     p->aRef[0] = 0;

  176937.     if( p->aRef[0]==0 && p->aRef[1]==0 && p->aRef[2]==0 ){

  176938.       sqlite3_free(p);

  176939.     }

  176940.   }

  176941. }

  176942. 

  176943. /* 

  176944. ** End of MatchinfoBuffer code.

  176945. *************************************************************************/

  176946. 

  176947. 

  176948. /*

  176949. ** This function is used to help iterate through a position-list. A position

  176950. ** list is a list of unique integers, sorted from smallest to largest. Each

  176951. ** element of the list is represented by an FTS3 varint that takes the value

  176952. ** of the difference between the current element and the previous one plus

  176953. ** two. For example, to store the position-list:

  176954. **

  176955. **     4 9 113

  176956. **

  176957. ** the three varints:

  176958. **

  176959. **     6 7 106

  176960. **

  176961. ** are encoded.

  176962. **

  176963. ** When this function is called, *pp points to the start of an element of

  176964. ** the list. *piPos contains the value of the previous entry in the list.

  176965. ** After it returns, *piPos contains the value of the next element of the

  176966. ** list and *pp is advanced to the following varint.

  176967. */

  176968. static void fts3GetDeltaPosition(char **pp, int *piPos){

  176969.   int iVal;

  176970.   *pp += fts3GetVarint32(*pp, &iVal);

  176971.   *piPos += (iVal-2);

  176972. }

  176973. 

  176974. /*

  176975. ** Helper function for fts3ExprIterate() (see below).

  176976. */

  176977. static int fts3ExprIterate2(

  176978.   Fts3Expr *pExpr,                /* Expression to iterate phrases of */

  176979.   int *piPhrase,                  /* Pointer to phrase counter */

  176980.   int (*x)(Fts3Expr*,int,void*),  /* Callback function to invoke for phrases */

  176981.   void *pCtx                      /* Second argument to pass to callback */

  176982. ){

  176983.   int rc;                         /* Return code */

  176984.   int eType = pExpr->eType;     /* Type of expression node pExpr */

  176985. 

  176986.   if( eType!=FTSQUERY_PHRASE ){

  176987.     assert( pExpr->pLeft && pExpr->pRight );

  176988.     rc = fts3ExprIterate2(pExpr->pLeft, piPhrase, x, pCtx);

  176989.     if( rc==SQLITE_OK && eType!=FTSQUERY_NOT ){

  176990.       rc = fts3ExprIterate2(pExpr->pRight, piPhrase, x, pCtx);

  176991.     }

  176992.   }else{

  176993.     rc = x(pExpr, *piPhrase, pCtx);

  176994.     (*piPhrase)++;

  176995.   }

  176996.   return rc;

  176997. }

  176998. 

  176999. /*

  177000. ** Iterate through all phrase nodes in an FTS3 query, except those that

  177001. ** are part of a sub-tree that is the right-hand-side of a NOT operator.

  177002. ** For each phrase node found, the supplied callback function is invoked.

  177003. **

  177004. ** If the callback function returns anything other than SQLITE_OK, 

  177005. ** the iteration is abandoned and the error code returned immediately.

  177006. ** Otherwise, SQLITE_OK is returned after a callback has been made for

  177007. ** all eligible phrase nodes.

  177008. */

  177009. static int fts3ExprIterate(

  177010.   Fts3Expr *pExpr,                /* Expression to iterate phrases of */

  177011.   int (*x)(Fts3Expr*,int,void*),  /* Callback function to invoke for phrases */

  177012.   void *pCtx                      /* Second argument to pass to callback */

  177013. ){

  177014.   int iPhrase = 0;                /* Variable used as the phrase counter */

  177015.   return fts3ExprIterate2(pExpr, &iPhrase, x, pCtx);

  177016. }

  177017. 

  177018. 

  177019. /*

  177020. ** This is an fts3ExprIterate() callback used while loading the doclists

  177021. ** for each phrase into Fts3Expr.aDoclist[]/nDoclist. See also

  177022. ** fts3ExprLoadDoclists().

  177023. */

  177024. static int fts3ExprLoadDoclistsCb(Fts3Expr *pExpr, int iPhrase, void *ctx){

  177025.   int rc = SQLITE_OK;

  177026.   Fts3Phrase *pPhrase = pExpr->pPhrase;

  177027.   LoadDoclistCtx *p = (LoadDoclistCtx *)ctx;

  177028. 

  177029.   UNUSED_PARAMETER(iPhrase);

  177030. 

  177031.   p->nPhrase++;

  177032.   p->nToken += pPhrase->nToken;

  177033. 

  177034.   return rc;

  177035. }

  177036. 

  177037. /*

  177038. ** Load the doclists for each phrase in the query associated with FTS3 cursor

  177039. ** pCsr. 

  177040. **

  177041. ** If pnPhrase is not NULL, then *pnPhrase is set to the number of matchable 

  177042. ** phrases in the expression (all phrases except those directly or 

  177043. ** indirectly descended from the right-hand-side of a NOT operator). If 

  177044. ** pnToken is not NULL, then it is set to the number of tokens in all

  177045. ** matchable phrases of the expression.

  177046. */

  177047. static int fts3ExprLoadDoclists(

  177048.   Fts3Cursor *pCsr,               /* Fts3 cursor for current query */

  177049.   int *pnPhrase,                  /* OUT: Number of phrases in query */

  177050.   int *pnToken                    /* OUT: Number of tokens in query */

  177051. ){

  177052.   int rc;                         /* Return Code */

  177053.   LoadDoclistCtx sCtx = {0,0,0};  /* Context for fts3ExprIterate() */

  177054.   sCtx.pCsr = pCsr;

  177055.   rc = fts3ExprIterate(pCsr->pExpr, fts3ExprLoadDoclistsCb, (void *)&sCtx);

  177056.   if( pnPhrase ) *pnPhrase = sCtx.nPhrase;

  177057.   if( pnToken ) *pnToken = sCtx.nToken;

  177058.   return rc;

  177059. }

  177060. 

  177061. static int fts3ExprPhraseCountCb(Fts3Expr *pExpr, int iPhrase, void *ctx){

  177062.   (*(int *)ctx)++;

  177063.   pExpr->iPhrase = iPhrase;

  177064.   return SQLITE_OK;

  177065. }

  177066. static int fts3ExprPhraseCount(Fts3Expr *pExpr){

  177067.   int nPhrase = 0;

  177068.   (void)fts3ExprIterate(pExpr, fts3ExprPhraseCountCb, (void *)&nPhrase);

  177069.   return nPhrase;

  177070. }

  177071. 

  177072. /*

  177073. ** Advance the position list iterator specified by the first two 

  177074. ** arguments so that it points to the first element with a value greater

  177075. ** than or equal to parameter iNext.

  177076. */

  177077. static void fts3SnippetAdvance(char **ppIter, int *piIter, int iNext){

  177078.   char *pIter = *ppIter;

  177079.   if( pIter ){

  177080.     int iIter = *piIter;

  177081. 

  177082.     while( iIter<iNext ){

  177083.       if( 0==(*pIter & 0xFE) ){

  177084.         iIter = -1;

  177085.         pIter = 0;

  177086.         break;

  177087.       }

  177088.       fts3GetDeltaPosition(&pIter, &iIter);

  177089.     }

  177090. 

  177091.     *piIter = iIter;

  177092.     *ppIter = pIter;

  177093.   }

  177094. }

  177095. 

  177096. /*

  177097. ** Advance the snippet iterator to the next candidate snippet.

  177098. */

  177099. static int fts3SnippetNextCandidate(SnippetIter *pIter){

  177100.   int i;                          /* Loop counter */

  177101. 

  177102.   if( pIter->iCurrent<0 ){

  177103.     /* The SnippetIter object has just been initialized. The first snippet

  177104.     ** candidate always starts at offset 0 (even if this candidate has a

  177105.     ** score of 0.0).

  177106.     */

  177107.     pIter->iCurrent = 0;

  177108. 

  177109.     /* Advance the 'head' iterator of each phrase to the first offset that

  177110.     ** is greater than or equal to (iNext+nSnippet).

  177111.     */

  177112.     for(i=0; i<pIter->nPhrase; i++){

  177113.       SnippetPhrase *pPhrase = &pIter->aPhrase[i];

  177114.       fts3SnippetAdvance(&pPhrase->pHead, &pPhrase->iHead, pIter->nSnippet);

  177115.     }

  177116.   }else{

  177117.     int iStart;

  177118.     int iEnd = 0x7FFFFFFF;

  177119. 

  177120.     for(i=0; i<pIter->nPhrase; i++){

  177121.       SnippetPhrase *pPhrase = &pIter->aPhrase[i];

  177122.       if( pPhrase->pHead && pPhrase->iHead<iEnd ){

  177123.         iEnd = pPhrase->iHead;

  177124.       }

  177125.     }

  177126.     if( iEnd==0x7FFFFFFF ){

  177127.       return 1;

  177128.     }

  177129. 

  177130.     pIter->iCurrent = iStart = iEnd - pIter->nSnippet + 1;

  177131.     for(i=0; i<pIter->nPhrase; i++){

  177132.       SnippetPhrase *pPhrase = &pIter->aPhrase[i];

  177133.       fts3SnippetAdvance(&pPhrase->pHead, &pPhrase->iHead, iEnd+1);

  177134.       fts3SnippetAdvance(&pPhrase->pTail, &pPhrase->iTail, iStart);

  177135.     }

  177136.   }

  177137. 

  177138.   return 0;

  177139. }

  177140. 

  177141. /*

  177142. ** Retrieve information about the current candidate snippet of snippet 

  177143. ** iterator pIter.

  177144. */

  177145. static void fts3SnippetDetails(

  177146.   SnippetIter *pIter,             /* Snippet iterator */

  177147.   u64 mCovered,                   /* Bitmask of phrases already covered */

  177148.   int *piToken,                   /* OUT: First token of proposed snippet */

  177149.   int *piScore,                   /* OUT: "Score" for this snippet */

  177150.   u64 *pmCover,                   /* OUT: Bitmask of phrases covered */

  177151.   u64 *pmHighlight                /* OUT: Bitmask of terms to highlight */

  177152. ){

  177153.   int iStart = pIter->iCurrent;   /* First token of snippet */

  177154.   int iScore = 0;                 /* Score of this snippet */

  177155.   int i;                          /* Loop counter */

  177156.   u64 mCover = 0;                 /* Mask of phrases covered by this snippet */

  177157.   u64 mHighlight = 0;             /* Mask of tokens to highlight in snippet */

  177158. 

  177159.   for(i=0; i<pIter->nPhrase; i++){

  177160.     SnippetPhrase *pPhrase = &pIter->aPhrase[i];

  177161.     if( pPhrase->pTail ){

  177162.       char *pCsr = pPhrase->pTail;

  177163.       int iCsr = pPhrase->iTail;

  177164. 

  177165.       while( iCsr<(iStart+pIter->nSnippet) && iCsr>=iStart ){

  177166.         int j;

  177167.         u64 mPhrase = (u64)1 << i;

  177168.         u64 mPos = (u64)1 << (iCsr - iStart);

  177169.         assert( iCsr>=iStart && (iCsr - iStart)<=64 );

  177170.         assert( i>=0 && i<=64 );

  177171.         if( (mCover|mCovered)&mPhrase ){

  177172.           iScore++;

  177173.         }else{

  177174.           iScore += 1000;

  177175.         }

  177176.         mCover |= mPhrase;

  177177. 

  177178.         for(j=0; j<pPhrase->nToken; j++){

  177179.           mHighlight |= (mPos>>j);

  177180.         }

  177181. 

  177182.         if( 0==(*pCsr & 0x0FE) ) break;

  177183.         fts3GetDeltaPosition(&pCsr, &iCsr);

  177184.       }

  177185.     }

  177186.   }

  177187. 

  177188.   /* Set the output variables before returning. */

  177189.   *piToken = iStart;

  177190.   *piScore = iScore;

  177191.   *pmCover = mCover;

  177192.   *pmHighlight = mHighlight;

  177193. }

  177194. 

  177195. /*

  177196. ** This function is an fts3ExprIterate() callback used by fts3BestSnippet().

  177197. ** Each invocation populates an element of the SnippetIter.aPhrase[] array.

  177198. */

  177199. static int fts3SnippetFindPositions(Fts3Expr *pExpr, int iPhrase, void *ctx){

  177200.   SnippetIter *p = (SnippetIter *)ctx;

  177201.   SnippetPhrase *pPhrase = &p->aPhrase[iPhrase];

  177202.   char *pCsr;

  177203.   int rc;

  177204. 

  177205.   pPhrase->nToken = pExpr->pPhrase->nToken;

  177206.   rc = sqlite3Fts3EvalPhrasePoslist(p->pCsr, pExpr, p->iCol, &pCsr);

  177207.   assert( rc==SQLITE_OK || pCsr==0 );

  177208.   if( pCsr ){

  177209.     int iFirst = 0;

  177210.     pPhrase->pList = pCsr;

  177211.     fts3GetDeltaPosition(&pCsr, &iFirst);

  177212.     if( iFirst<0 ){

  177213.       rc = FTS_CORRUPT_VTAB;

  177214.     }else{

  177215.       pPhrase->pHead = pCsr;

  177216.       pPhrase->pTail = pCsr;

  177217.       pPhrase->iHead = iFirst;

  177218.       pPhrase->iTail = iFirst;

  177219.     }

  177220.   }else{

  177221.     assert( rc!=SQLITE_OK || (

  177222.        pPhrase->pList==0 && pPhrase->pHead==0 && pPhrase->pTail==0 

  177223.     ));

  177224.   }

  177225. 

  177226.   return rc;

  177227. }

  177228. 

  177229. /*

  177230. ** Select the fragment of text consisting of nFragment contiguous tokens 

  177231. ** from column iCol that represent the "best" snippet. The best snippet

  177232. ** is the snippet with the highest score, where scores are calculated

  177233. ** by adding:

  177234. **

  177235. **   (a) +1 point for each occurrence of a matchable phrase in the snippet.

  177236. **

  177237. **   (b) +1000 points for the first occurrence of each matchable phrase in 

  177238. **       the snippet for which the corresponding mCovered bit is not set.

  177239. **

  177240. ** The selected snippet parameters are stored in structure *pFragment before

  177241. ** returning. The score of the selected snippet is stored in *piScore

  177242. ** before returning.

  177243. */

  177244. static int fts3BestSnippet(

  177245.   int nSnippet,                   /* Desired snippet length */

  177246.   Fts3Cursor *pCsr,               /* Cursor to create snippet for */

  177247.   int iCol,                       /* Index of column to create snippet from */

  177248.   u64 mCovered,                   /* Mask of phrases already covered */

  177249.   u64 *pmSeen,                    /* IN/OUT: Mask of phrases seen */

  177250.   SnippetFragment *pFragment,     /* OUT: Best snippet found */

  177251.   int *piScore                    /* OUT: Score of snippet pFragment */

  177252. ){

  177253.   int rc;                         /* Return Code */

  177254.   int nList;                      /* Number of phrases in expression */

  177255.   SnippetIter sIter;              /* Iterates through snippet candidates */

  177256.   sqlite3_int64 nByte;            /* Number of bytes of space to allocate */

  177257.   int iBestScore = -1;            /* Best snippet score found so far */

  177258.   int i;                          /* Loop counter */

  177259. 

  177260.   memset(&sIter, 0, sizeof(sIter));

  177261. 

  177262.   /* Iterate through the phrases in the expression to count them. The same

  177263.   ** callback makes sure the doclists are loaded for each phrase.

  177264.   */

  177265.   rc = fts3ExprLoadDoclists(pCsr, &nList, 0);

  177266.   if( rc!=SQLITE_OK ){

  177267.     return rc;

  177268.   }

  177269. 

  177270.   /* Now that it is known how many phrases there are, allocate and zero

  177271.   ** the required space using malloc().

  177272.   */

  177273.   nByte = sizeof(SnippetPhrase) * nList;

  177274.   sIter.aPhrase = (SnippetPhrase *)sqlite3_malloc64(nByte);

  177275.   if( !sIter.aPhrase ){

  177276.     return SQLITE_NOMEM;

  177277.   }

  177278.   memset(sIter.aPhrase, 0, nByte);

  177279. 

  177280.   /* Initialize the contents of the SnippetIter object. Then iterate through

  177281.   ** the set of phrases in the expression to populate the aPhrase[] array.

  177282.   */

  177283.   sIter.pCsr = pCsr;

  177284.   sIter.iCol = iCol;

  177285.   sIter.nSnippet = nSnippet;

  177286.   sIter.nPhrase = nList;

  177287.   sIter.iCurrent = -1;

  177288.   rc = fts3ExprIterate(pCsr->pExpr, fts3SnippetFindPositions, (void*)&sIter);

  177289.   if( rc==SQLITE_OK ){

  177290. 

  177291.     /* Set the *pmSeen output variable. */

  177292.     for(i=0; i<nList; i++){

  177293.       if( sIter.aPhrase[i].pHead ){

  177294.         *pmSeen |= (u64)1 << i;

  177295.       }

  177296.     }

  177297. 

  177298.     /* Loop through all candidate snippets. Store the best snippet in 

  177299.      ** *pFragment. Store its associated 'score' in iBestScore.

  177300.      */

  177301.     pFragment->iCol = iCol;

  177302.     while( !fts3SnippetNextCandidate(&sIter) ){

  177303.       int iPos;

  177304.       int iScore;

  177305.       u64 mCover;

  177306.       u64 mHighlite;

  177307.       fts3SnippetDetails(&sIter, mCovered, &iPos, &iScore, &mCover,&mHighlite);

  177308.       assert( iScore>=0 );

  177309.       if( iScore>iBestScore ){

  177310.         pFragment->iPos = iPos;

  177311.         pFragment->hlmask = mHighlite;

  177312.         pFragment->covered = mCover;

  177313.         iBestScore = iScore;

  177314.       }

  177315.     }

  177316. 

  177317.     *piScore = iBestScore;

  177318.   }

  177319.   sqlite3_free(sIter.aPhrase);

  177320.   return rc;

  177321. }

  177322. 

  177323. 

  177324. /*

  177325. ** Append a string to the string-buffer passed as the first argument.

  177326. **

  177327. ** If nAppend is negative, then the length of the string zAppend is

  177328. ** determined using strlen().

  177329. */

  177330. static int fts3StringAppend(

  177331.   StrBuffer *pStr,                /* Buffer to append to */

  177332.   const char *zAppend,            /* Pointer to data to append to buffer */

  177333.   int nAppend                     /* Size of zAppend in bytes (or -1) */

  177334. ){

  177335.   if( nAppend<0 ){

  177336.     nAppend = (int)strlen(zAppend);

  177337.   }

  177338. 

  177339.   /* If there is insufficient space allocated at StrBuffer.z, use realloc()

  177340.   ** to grow the buffer until so that it is big enough to accomadate the

  177341.   ** appended data.

  177342.   */

  177343.   if( pStr->n+nAppend+1>=pStr->nAlloc ){

  177344.     sqlite3_int64 nAlloc = pStr->nAlloc+(sqlite3_int64)nAppend+100;

  177345.     char *zNew = sqlite3_realloc64(pStr->z, nAlloc);

  177346.     if( !zNew ){

  177347.       return SQLITE_NOMEM;

  177348.     }

  177349.     pStr->z = zNew;

  177350.     pStr->nAlloc = nAlloc;

  177351.   }

  177352.   assert( pStr->z!=0 && (pStr->nAlloc >= pStr->n+nAppend+1) );

  177353. 

  177354.   /* Append the data to the string buffer. */

  177355.   memcpy(&pStr->z[pStr->n], zAppend, nAppend);

  177356.   pStr->n += nAppend;

  177357.   pStr->z[pStr->n] = '\0';

  177358. 

  177359.   return SQLITE_OK;

  177360. }

  177361. 

  177362. /*

  177363. ** The fts3BestSnippet() function often selects snippets that end with a

  177364. ** query term. That is, the final term of the snippet is always a term

  177365. ** that requires highlighting. For example, if 'X' is a highlighted term

  177366. ** and '.' is a non-highlighted term, BestSnippet() may select:

  177367. **

  177368. **     ........X.....X

  177369. **

  177370. ** This function "shifts" the beginning of the snippet forward in the 

  177371. ** document so that there are approximately the same number of 

  177372. ** non-highlighted terms to the right of the final highlighted term as there

  177373. ** are to the left of the first highlighted term. For example, to this:

  177374. **

  177375. **     ....X.....X....

  177376. **

  177377. ** This is done as part of extracting the snippet text, not when selecting

  177378. ** the snippet. Snippet selection is done based on doclists only, so there

  177379. ** is no way for fts3BestSnippet() to know whether or not the document 

  177380. ** actually contains terms that follow the final highlighted term. 

  177381. */

  177382. static int fts3SnippetShift(

  177383.   Fts3Table *pTab,                /* FTS3 table snippet comes from */

  177384.   int iLangid,                    /* Language id to use in tokenizing */

  177385.   int nSnippet,                   /* Number of tokens desired for snippet */

  177386.   const char *zDoc,               /* Document text to extract snippet from */

  177387.   int nDoc,                       /* Size of buffer zDoc in bytes */

  177388.   int *piPos,                     /* IN/OUT: First token of snippet */

  177389.   u64 *pHlmask                    /* IN/OUT: Mask of tokens to highlight */

  177390. ){

  177391.   u64 hlmask = *pHlmask;          /* Local copy of initial highlight-mask */

  177392. 

  177393.   if( hlmask ){

  177394.     int nLeft;                    /* Tokens to the left of first highlight */

  177395.     int nRight;                   /* Tokens to the right of last highlight */

  177396.     int nDesired;                 /* Ideal number of tokens to shift forward */

  177397. 

  177398.     for(nLeft=0; !(hlmask & ((u64)1 << nLeft)); nLeft++);

  177399.     for(nRight=0; !(hlmask & ((u64)1 << (nSnippet-1-nRight))); nRight++);

  177400.     assert( (nSnippet-1-nRight)<=63 && (nSnippet-1-nRight)>=0 );

  177401.     nDesired = (nLeft-nRight)/2;

  177402. 

  177403.     /* Ideally, the start of the snippet should be pushed forward in the

  177404.     ** document nDesired tokens. This block checks if there are actually

  177405.     ** nDesired tokens to the right of the snippet. If so, *piPos and

  177406.     ** *pHlMask are updated to shift the snippet nDesired tokens to the

  177407.     ** right. Otherwise, the snippet is shifted by the number of tokens

  177408.     ** available.

  177409.     */

  177410.     if( nDesired>0 ){

  177411.       int nShift;                 /* Number of tokens to shift snippet by */

  177412.       int iCurrent = 0;           /* Token counter */

  177413.       int rc;                     /* Return Code */

  177414.       sqlite3_tokenizer_module *pMod;

  177415.       sqlite3_tokenizer_cursor *pC;

  177416.       pMod = (sqlite3_tokenizer_module *)pTab->pTokenizer->pModule;

  177417. 

  177418.       /* Open a cursor on zDoc/nDoc. Check if there are (nSnippet+nDesired)

  177419.       ** or more tokens in zDoc/nDoc.

  177420.       */

  177421.       rc = sqlite3Fts3OpenTokenizer(pTab->pTokenizer, iLangid, zDoc, nDoc, &pC);

  177422.       if( rc!=SQLITE_OK ){

  177423.         return rc;

  177424.       }

  177425.       while( rc==SQLITE_OK && iCurrent<(nSnippet+nDesired) ){

  177426.         const char *ZDUMMY; int DUMMY1 = 0, DUMMY2 = 0, DUMMY3 = 0;

  177427.         rc = pMod->xNext(pC, &ZDUMMY, &DUMMY1, &DUMMY2, &DUMMY3, &iCurrent);

  177428.       }

  177429.       pMod->xClose(pC);

  177430.       if( rc!=SQLITE_OK && rc!=SQLITE_DONE ){ return rc; }

  177431. 

  177432.       nShift = (rc==SQLITE_DONE)+iCurrent-nSnippet;

  177433.       assert( nShift<=nDesired );

  177434.       if( nShift>0 ){

  177435.         *piPos += nShift;

  177436.         *pHlmask = hlmask >> nShift;

  177437.       }

  177438.     }

  177439.   }

  177440.   return SQLITE_OK;

  177441. }

  177442. 

  177443. /*

  177444. ** Extract the snippet text for fragment pFragment from cursor pCsr and

  177445. ** append it to string buffer pOut.

  177446. */

  177447. static int fts3SnippetText(

  177448.   Fts3Cursor *pCsr,               /* FTS3 Cursor */

  177449.   SnippetFragment *pFragment,     /* Snippet to extract */

  177450.   int iFragment,                  /* Fragment number */

  177451.   int isLast,                     /* True for final fragment in snippet */

  177452.   int nSnippet,                   /* Number of tokens in extracted snippet */

  177453.   const char *zOpen,              /* String inserted before highlighted term */

  177454.   const char *zClose,             /* String inserted after highlighted term */

  177455.   const char *zEllipsis,          /* String inserted between snippets */

  177456.   StrBuffer *pOut                 /* Write output here */

  177457. ){

  177458.   Fts3Table *pTab = (Fts3Table *)pCsr->base.pVtab;

  177459.   int rc;                         /* Return code */

  177460.   const char *zDoc;               /* Document text to extract snippet from */

  177461.   int nDoc;                       /* Size of zDoc in bytes */

  177462.   int iCurrent = 0;               /* Current token number of document */

  177463.   int iEnd = 0;                   /* Byte offset of end of current token */

  177464.   int isShiftDone = 0;            /* True after snippet is shifted */

  177465.   int iPos = pFragment->iPos;     /* First token of snippet */

  177466.   u64 hlmask = pFragment->hlmask; /* Highlight-mask for snippet */

  177467.   int iCol = pFragment->iCol+1;   /* Query column to extract text from */

  177468.   sqlite3_tokenizer_module *pMod; /* Tokenizer module methods object */

  177469.   sqlite3_tokenizer_cursor *pC;   /* Tokenizer cursor open on zDoc/nDoc */

  177470.   

  177471.   zDoc = (const char *)sqlite3_column_text(pCsr->pStmt, iCol);

  177472.   if( zDoc==0 ){

  177473.     if( sqlite3_column_type(pCsr->pStmt, iCol)!=SQLITE_NULL ){

  177474.       return SQLITE_NOMEM;

  177475.     }

  177476.     return SQLITE_OK;

  177477.   }

  177478.   nDoc = sqlite3_column_bytes(pCsr->pStmt, iCol);

  177479. 

  177480.   /* Open a token cursor on the document. */

  177481.   pMod = (sqlite3_tokenizer_module *)pTab->pTokenizer->pModule;

  177482.   rc = sqlite3Fts3OpenTokenizer(pTab->pTokenizer, pCsr->iLangid, zDoc,nDoc,&pC);

  177483.   if( rc!=SQLITE_OK ){

  177484.     return rc;

  177485.   }

  177486. 

  177487.   while( rc==SQLITE_OK ){

  177488.     const char *ZDUMMY;           /* Dummy argument used with tokenizer */

  177489.     int DUMMY1 = -1;              /* Dummy argument used with tokenizer */

  177490.     int iBegin = 0;               /* Offset in zDoc of start of token */

  177491.     int iFin = 0;                 /* Offset in zDoc of end of token */

  177492.     int isHighlight = 0;          /* True for highlighted terms */

  177493. 

  177494.     /* Variable DUMMY1 is initialized to a negative value above. Elsewhere

  177495.     ** in the FTS code the variable that the third argument to xNext points to

  177496.     ** is initialized to zero before the first (*but not necessarily

  177497.     ** subsequent*) call to xNext(). This is done for a particular application

  177498.     ** that needs to know whether or not the tokenizer is being used for

  177499.     ** snippet generation or for some other purpose.

  177500.     **

  177501.     ** Extreme care is required when writing code to depend on this

  177502.     ** initialization. It is not a documented part of the tokenizer interface.

  177503.     ** If a tokenizer is used directly by any code outside of FTS, this

  177504.     ** convention might not be respected.  */

  177505.     rc = pMod->xNext(pC, &ZDUMMY, &DUMMY1, &iBegin, &iFin, &iCurrent);

  177506.     if( rc!=SQLITE_OK ){

  177507.       if( rc==SQLITE_DONE ){

  177508.         /* Special case - the last token of the snippet is also the last token

  177509.         ** of the column. Append any punctuation that occurred between the end

  177510.         ** of the previous token and the end of the document to the output. 

  177511.         ** Then break out of the loop. */

  177512.         rc = fts3StringAppend(pOut, &zDoc[iEnd], -1);

  177513.       }

  177514.       break;

  177515.     }

  177516.     if( iCurrent<iPos ){ continue; }

  177517. 

  177518.     if( !isShiftDone ){

  177519.       int n = nDoc - iBegin;

  177520.       rc = fts3SnippetShift(

  177521.           pTab, pCsr->iLangid, nSnippet, &zDoc[iBegin], n, &iPos, &hlmask

  177522.       );

  177523.       isShiftDone = 1;

  177524. 

  177525.       /* Now that the shift has been done, check if the initial "..." are

  177526.       ** required. They are required if (a) this is not the first fragment,

  177527.       ** or (b) this fragment does not begin at position 0 of its column. 

  177528.       */

  177529.       if( rc==SQLITE_OK ){

  177530.         if( iPos>0 || iFragment>0 ){

  177531.           rc = fts3StringAppend(pOut, zEllipsis, -1);

  177532.         }else if( iBegin ){

  177533.           rc = fts3StringAppend(pOut, zDoc, iBegin);

  177534.         }

  177535.       }

  177536.       if( rc!=SQLITE_OK || iCurrent<iPos ) continue;

  177537.     }

  177538. 

  177539.     if( iCurrent>=(iPos+nSnippet) ){

  177540.       if( isLast ){

  177541.         rc = fts3StringAppend(pOut, zEllipsis, -1);

  177542.       }

  177543.       break;

  177544.     }

  177545. 

  177546.     /* Set isHighlight to true if this term should be highlighted. */

  177547.     isHighlight = (hlmask & ((u64)1 << (iCurrent-iPos)))!=0;

  177548. 

  177549.     if( iCurrent>iPos ) rc = fts3StringAppend(pOut, &zDoc[iEnd], iBegin-iEnd);

  177550.     if( rc==SQLITE_OK && isHighlight ) rc = fts3StringAppend(pOut, zOpen, -1);

  177551.     if( rc==SQLITE_OK ) rc = fts3StringAppend(pOut, &zDoc[iBegin], iFin-iBegin);

  177552.     if( rc==SQLITE_OK && isHighlight ) rc = fts3StringAppend(pOut, zClose, -1);

  177553. 

  177554.     iEnd = iFin;

  177555.   }

  177556. 

  177557.   pMod->xClose(pC);

  177558.   return rc;

  177559. }

  177560. 

  177561. 

  177562. /*

  177563. ** This function is used to count the entries in a column-list (a 

  177564. ** delta-encoded list of term offsets within a single column of a single 

  177565. ** row). When this function is called, *ppCollist should point to the

  177566. ** beginning of the first varint in the column-list (the varint that

  177567. ** contains the position of the first matching term in the column data).

  177568. ** Before returning, *ppCollist is set to point to the first byte after

  177569. ** the last varint in the column-list (either the 0x00 signifying the end

  177570. ** of the position-list, or the 0x01 that precedes the column number of

  177571. ** the next column in the position-list).

  177572. **

  177573. ** The number of elements in the column-list is returned.

  177574. */

  177575. static int fts3ColumnlistCount(char **ppCollist){

  177576.   char *pEnd = *ppCollist;

  177577.   char c = 0;

  177578.   int nEntry = 0;

  177579. 

  177580.   /* A column-list is terminated by either a 0x01 or 0x00. */

  177581.   while( 0xFE & (*pEnd | c) ){

  177582.     c = *pEnd++ & 0x80;

  177583.     if( !c ) nEntry++;

  177584.   }

  177585. 

  177586.   *ppCollist = pEnd;

  177587.   return nEntry;

  177588. }

  177589. 

  177590. /*

  177591. ** This function gathers 'y' or 'b' data for a single phrase.

  177592. */

  177593. static int fts3ExprLHits(

  177594.   Fts3Expr *pExpr,                /* Phrase expression node */

  177595.   MatchInfo *p                    /* Matchinfo context */

  177596. ){

  177597.   Fts3Table *pTab = (Fts3Table *)p->pCursor->base.pVtab;

  177598.   int iStart;

  177599.   Fts3Phrase *pPhrase = pExpr->pPhrase;

  177600.   char *pIter = pPhrase->doclist.pList;

  177601.   int iCol = 0;

  177602. 

  177603.   assert( p->flag==FTS3_MATCHINFO_LHITS_BM || p->flag==FTS3_MATCHINFO_LHITS );

  177604.   if( p->flag==FTS3_MATCHINFO_LHITS ){

  177605.     iStart = pExpr->iPhrase * p->nCol;

  177606.   }else{

  177607.     iStart = pExpr->iPhrase * ((p->nCol + 31) / 32);

  177608.   }

  177609. 

  177610.   while( 1 ){

  177611.     int nHit = fts3ColumnlistCount(&pIter);

  177612.     if( (pPhrase->iColumn>=pTab->nColumn || pPhrase->iColumn==iCol) ){

  177613.       if( p->flag==FTS3_MATCHINFO_LHITS ){

  177614.         p->aMatchinfo[iStart + iCol] = (u32)nHit;

  177615.       }else if( nHit ){

  177616.         p->aMatchinfo[iStart + (iCol+1)/32] |= (1 << (iCol&0x1F));

  177617.       }

  177618.     }

  177619.     assert( *pIter==0x00 || *pIter==0x01 );

  177620.     if( *pIter!=0x01 ) break;

  177621.     pIter++;

  177622.     pIter += fts3GetVarint32(pIter, &iCol);

  177623.     if( iCol>=p->nCol ) return FTS_CORRUPT_VTAB;

  177624.   }

  177625.   return SQLITE_OK;

  177626. }

  177627. 

  177628. /*

  177629. ** Gather the results for matchinfo directives 'y' and 'b'.

  177630. */

  177631. static int fts3ExprLHitGather(

  177632.   Fts3Expr *pExpr,

  177633.   MatchInfo *p

  177634. ){

  177635.   int rc = SQLITE_OK;

  177636.   assert( (pExpr->pLeft==0)==(pExpr->pRight==0) );

  177637.   if( pExpr->bEof==0 && pExpr->iDocid==p->pCursor->iPrevId ){

  177638.     if( pExpr->pLeft ){

  177639.       rc = fts3ExprLHitGather(pExpr->pLeft, p);

  177640.       if( rc==SQLITE_OK ) rc = fts3ExprLHitGather(pExpr->pRight, p);

  177641.     }else{

  177642.       rc = fts3ExprLHits(pExpr, p);

  177643.     }

  177644.   }

  177645.   return rc;

  177646. }

  177647. 

  177648. /*

  177649. ** fts3ExprIterate() callback used to collect the "global" matchinfo stats

  177650. ** for a single query. 

  177651. **

  177652. ** fts3ExprIterate() callback to load the 'global' elements of a

  177653. ** FTS3_MATCHINFO_HITS matchinfo array. The global stats are those elements 

  177654. ** of the matchinfo array that are constant for all rows returned by the 

  177655. ** current query.

  177656. **

  177657. ** Argument pCtx is actually a pointer to a struct of type MatchInfo. This

  177658. ** function populates Matchinfo.aMatchinfo[] as follows:

  177659. **

  177660. **   for(iCol=0; iCol<nCol; iCol++){

  177661. **     aMatchinfo[3*iPhrase*nCol + 3*iCol + 1] = X;

  177662. **     aMatchinfo[3*iPhrase*nCol + 3*iCol + 2] = Y;

  177663. **   }

  177664. **

  177665. ** where X is the number of matches for phrase iPhrase is column iCol of all

  177666. ** rows of the table. Y is the number of rows for which column iCol contains

  177667. ** at least one instance of phrase iPhrase.

  177668. **

  177669. ** If the phrase pExpr consists entirely of deferred tokens, then all X and

  177670. ** Y values are set to nDoc, where nDoc is the number of documents in the 

  177671. ** file system. This is done because the full-text index doclist is required

  177672. ** to calculate these values properly, and the full-text index doclist is

  177673. ** not available for deferred tokens.

  177674. */

  177675. static int fts3ExprGlobalHitsCb(

  177676.   Fts3Expr *pExpr,                /* Phrase expression node */

  177677.   int iPhrase,                    /* Phrase number (numbered from zero) */

  177678.   void *pCtx                      /* Pointer to MatchInfo structure */

  177679. ){

  177680.   MatchInfo *p = (MatchInfo *)pCtx;

  177681.   return sqlite3Fts3EvalPhraseStats(

  177682.       p->pCursor, pExpr, &p->aMatchinfo[3*iPhrase*p->nCol]

  177683.   );

  177684. }

  177685. 

  177686. /*

  177687. ** fts3ExprIterate() callback used to collect the "local" part of the

  177688. ** FTS3_MATCHINFO_HITS array. The local stats are those elements of the 

  177689. ** array that are different for each row returned by the query.

  177690. */

  177691. static int fts3ExprLocalHitsCb(

  177692.   Fts3Expr *pExpr,                /* Phrase expression node */

  177693.   int iPhrase,                    /* Phrase number */

  177694.   void *pCtx                      /* Pointer to MatchInfo structure */

  177695. ){

  177696.   int rc = SQLITE_OK;

  177697.   MatchInfo *p = (MatchInfo *)pCtx;

  177698.   int iStart = iPhrase * p->nCol * 3;

  177699.   int i;

  177700. 

  177701.   for(i=0; i<p->nCol && rc==SQLITE_OK; i++){

  177702.     char *pCsr;

  177703.     rc = sqlite3Fts3EvalPhrasePoslist(p->pCursor, pExpr, i, &pCsr);

  177704.     if( pCsr ){

  177705.       p->aMatchinfo[iStart+i*3] = fts3ColumnlistCount(&pCsr);

  177706.     }else{

  177707.       p->aMatchinfo[iStart+i*3] = 0;

  177708.     }

  177709.   }

  177710. 

  177711.   return rc;

  177712. }

  177713. 

  177714. static int fts3MatchinfoCheck(

  177715.   Fts3Table *pTab, 

  177716.   char cArg,

  177717.   char **pzErr

  177718. ){

  177719.   if( (cArg==FTS3_MATCHINFO_NPHRASE)

  177720.    || (cArg==FTS3_MATCHINFO_NCOL)

  177721.    || (cArg==FTS3_MATCHINFO_NDOC && pTab->bFts4)

  177722.    || (cArg==FTS3_MATCHINFO_AVGLENGTH && pTab->bFts4)

  177723.    || (cArg==FTS3_MATCHINFO_LENGTH && pTab->bHasDocsize)

  177724.    || (cArg==FTS3_MATCHINFO_LCS)

  177725.    || (cArg==FTS3_MATCHINFO_HITS)

  177726.    || (cArg==FTS3_MATCHINFO_LHITS)

  177727.    || (cArg==FTS3_MATCHINFO_LHITS_BM)

  177728.   ){

  177729.     return SQLITE_OK;

  177730.   }

  177731.   sqlite3Fts3ErrMsg(pzErr, "unrecognized matchinfo request: %c", cArg);

  177732.   return SQLITE_ERROR;

  177733. }

  177734. 

  177735. static size_t fts3MatchinfoSize(MatchInfo *pInfo, char cArg){

  177736.   size_t nVal;                      /* Number of integers output by cArg */

  177737. 

  177738.   switch( cArg ){

  177739.     case FTS3_MATCHINFO_NDOC:

  177740.     case FTS3_MATCHINFO_NPHRASE: 

  177741.     case FTS3_MATCHINFO_NCOL: 

  177742.       nVal = 1;

  177743.       break;

  177744. 

  177745.     case FTS3_MATCHINFO_AVGLENGTH:

  177746.     case FTS3_MATCHINFO_LENGTH:

  177747.     case FTS3_MATCHINFO_LCS:

  177748.       nVal = pInfo->nCol;

  177749.       break;

  177750. 

  177751.     case FTS3_MATCHINFO_LHITS:

  177752.       nVal = pInfo->nCol * pInfo->nPhrase;

  177753.       break;

  177754. 

  177755.     case FTS3_MATCHINFO_LHITS_BM:

  177756.       nVal = pInfo->nPhrase * ((pInfo->nCol + 31) / 32);

  177757.       break;

  177758. 

  177759.     default:

  177760.       assert( cArg==FTS3_MATCHINFO_HITS );

  177761.       nVal = pInfo->nCol * pInfo->nPhrase * 3;

  177762.       break;

  177763.   }

  177764. 

  177765.   return nVal;

  177766. }

  177767. 

  177768. static int fts3MatchinfoSelectDoctotal(

  177769.   Fts3Table *pTab,

  177770.   sqlite3_stmt **ppStmt,

  177771.   sqlite3_int64 *pnDoc,

  177772.   const char **paLen

  177773. ){

  177774.   sqlite3_stmt *pStmt;

  177775.   const char *a;

  177776.   sqlite3_int64 nDoc;

  177777. 

  177778.   if( !*ppStmt ){

  177779.     int rc = sqlite3Fts3SelectDoctotal(pTab, ppStmt);

  177780.     if( rc!=SQLITE_OK ) return rc;

  177781.   }

  177782.   pStmt = *ppStmt;

  177783.   assert( sqlite3_data_count(pStmt)==1 );

  177784. 

  177785.   a = sqlite3_column_blob(pStmt, 0);

  177786.   a += sqlite3Fts3GetVarint(a, &nDoc);

  177787.   if( nDoc==0 ) return FTS_CORRUPT_VTAB;

  177788.   *pnDoc = (u32)nDoc;

  177789. 

  177790.   if( paLen ) *paLen = a;

  177791.   return SQLITE_OK;

  177792. }

  177793. 

  177794. /*

  177795. ** An instance of the following structure is used to store state while 

  177796. ** iterating through a multi-column position-list corresponding to the

  177797. ** hits for a single phrase on a single row in order to calculate the

  177798. ** values for a matchinfo() FTS3_MATCHINFO_LCS request.

  177799. */

  177800. typedef struct LcsIterator LcsIterator;

  177801. struct LcsIterator {

  177802.   Fts3Expr *pExpr;                /* Pointer to phrase expression */

  177803.   int iPosOffset;                 /* Tokens count up to end of this phrase */

  177804.   char *pRead;                    /* Cursor used to iterate through aDoclist */

  177805.   int iPos;                       /* Current position */

  177806. };

  177807. 

  177808. /* 

  177809. ** If LcsIterator.iCol is set to the following value, the iterator has

  177810. ** finished iterating through all offsets for all columns.

  177811. */

  177812. #define LCS_ITERATOR_FINISHED 0x7FFFFFFF;

  177813. 

  177814. static int fts3MatchinfoLcsCb(

  177815.   Fts3Expr *pExpr,                /* Phrase expression node */

  177816.   int iPhrase,                    /* Phrase number (numbered from zero) */

  177817.   void *pCtx                      /* Pointer to MatchInfo structure */

  177818. ){

  177819.   LcsIterator *aIter = (LcsIterator *)pCtx;

  177820.   aIter[iPhrase].pExpr = pExpr;

  177821.   return SQLITE_OK;

  177822. }

  177823. 

  177824. /*

  177825. ** Advance the iterator passed as an argument to the next position. Return

  177826. ** 1 if the iterator is at EOF or if it now points to the start of the

  177827. ** position list for the next column.

  177828. */

  177829. static int fts3LcsIteratorAdvance(LcsIterator *pIter){

  177830.   char *pRead = pIter->pRead;

  177831.   sqlite3_int64 iRead;

  177832.   int rc = 0;

  177833. 

  177834.   pRead += sqlite3Fts3GetVarint(pRead, &iRead);

  177835.   if( iRead==0 || iRead==1 ){

  177836.     pRead = 0;

  177837.     rc = 1;

  177838.   }else{

  177839.     pIter->iPos += (int)(iRead-2);

  177840.   }

  177841. 

  177842.   pIter->pRead = pRead;

  177843.   return rc;

  177844. }

  177845.   

  177846. /*

  177847. ** This function implements the FTS3_MATCHINFO_LCS matchinfo() flag. 

  177848. **

  177849. ** If the call is successful, the longest-common-substring lengths for each

  177850. ** column are written into the first nCol elements of the pInfo->aMatchinfo[] 

  177851. ** array before returning. SQLITE_OK is returned in this case.

  177852. **

  177853. ** Otherwise, if an error occurs, an SQLite error code is returned and the

  177854. ** data written to the first nCol elements of pInfo->aMatchinfo[] is 

  177855. ** undefined.

  177856. */

  177857. static int fts3MatchinfoLcs(Fts3Cursor *pCsr, MatchInfo *pInfo){

  177858.   LcsIterator *aIter;

  177859.   int i;

  177860.   int iCol;

  177861.   int nToken = 0;

  177862.   int rc = SQLITE_OK;

  177863. 

  177864.   /* Allocate and populate the array of LcsIterator objects. The array

  177865.   ** contains one element for each matchable phrase in the query.

  177866.   **/

  177867.   aIter = sqlite3_malloc64(sizeof(LcsIterator) * pCsr->nPhrase);

  177868.   if( !aIter ) return SQLITE_NOMEM;

  177869.   memset(aIter, 0, sizeof(LcsIterator) * pCsr->nPhrase);

  177870.   (void)fts3ExprIterate(pCsr->pExpr, fts3MatchinfoLcsCb, (void*)aIter);

  177871. 

  177872.   for(i=0; i<pInfo->nPhrase; i++){

  177873.     LcsIterator *pIter = &aIter[i];

  177874.     nToken -= pIter->pExpr->pPhrase->nToken;

  177875.     pIter->iPosOffset = nToken;

  177876.   }

  177877. 

  177878.   for(iCol=0; iCol<pInfo->nCol; iCol++){

  177879.     int nLcs = 0;                 /* LCS value for this column */

  177880.     int nLive = 0;                /* Number of iterators in aIter not at EOF */

  177881. 

  177882.     for(i=0; i<pInfo->nPhrase; i++){

  177883.       LcsIterator *pIt = &aIter[i];

  177884.       rc = sqlite3Fts3EvalPhrasePoslist(pCsr, pIt->pExpr, iCol, &pIt->pRead);

  177885.       if( rc!=SQLITE_OK ) goto matchinfo_lcs_out;

  177886.       if( pIt->pRead ){

  177887.         pIt->iPos = pIt->iPosOffset;

  177888.         fts3LcsIteratorAdvance(pIt);

  177889.         if( pIt->pRead==0 ){

  177890.           rc = FTS_CORRUPT_VTAB;

  177891.           goto matchinfo_lcs_out;

  177892.         }

  177893.         nLive++;

  177894.       }

  177895.     }

  177896. 

  177897.     while( nLive>0 ){

  177898.       LcsIterator *pAdv = 0;      /* The iterator to advance by one position */

  177899.       int nThisLcs = 0;           /* LCS for the current iterator positions */

  177900. 

  177901.       for(i=0; i<pInfo->nPhrase; i++){

  177902.         LcsIterator *pIter = &aIter[i];

  177903.         if( pIter->pRead==0 ){

  177904.           /* This iterator is already at EOF for this column. */

  177905.           nThisLcs = 0;

  177906.         }else{

  177907.           if( pAdv==0 || pIter->iPos<pAdv->iPos ){

  177908.             pAdv = pIter;

  177909.           }

  177910.           if( nThisLcs==0 || pIter->iPos==pIter[-1].iPos ){

  177911.             nThisLcs++;

  177912.           }else{

  177913.             nThisLcs = 1;

  177914.           }

  177915.           if( nThisLcs>nLcs ) nLcs = nThisLcs;

  177916.         }

  177917.       }

  177918.       if( fts3LcsIteratorAdvance(pAdv) ) nLive--;

  177919.     }

  177920. 

  177921.     pInfo->aMatchinfo[iCol] = nLcs;

  177922.   }

  177923. 

  177924.  matchinfo_lcs_out:

  177925.   sqlite3_free(aIter);

  177926.   return rc;

  177927. }

  177928. 

  177929. /*

  177930. ** Populate the buffer pInfo->aMatchinfo[] with an array of integers to

  177931. ** be returned by the matchinfo() function. Argument zArg contains the 

  177932. ** format string passed as the second argument to matchinfo (or the

  177933. ** default value "pcx" if no second argument was specified). The format

  177934. ** string has already been validated and the pInfo->aMatchinfo[] array

  177935. ** is guaranteed to be large enough for the output.

  177936. **

  177937. ** If bGlobal is true, then populate all fields of the matchinfo() output.

  177938. ** If it is false, then assume that those fields that do not change between

  177939. ** rows (i.e. FTS3_MATCHINFO_NPHRASE, NCOL, NDOC, AVGLENGTH and part of HITS)

  177940. ** have already been populated.

  177941. **

  177942. ** Return SQLITE_OK if successful, or an SQLite error code if an error 

  177943. ** occurs. If a value other than SQLITE_OK is returned, the state the

  177944. ** pInfo->aMatchinfo[] buffer is left in is undefined.

  177945. */

  177946. static int fts3MatchinfoValues(

  177947.   Fts3Cursor *pCsr,               /* FTS3 cursor object */

  177948.   int bGlobal,                    /* True to grab the global stats */

  177949.   MatchInfo *pInfo,               /* Matchinfo context object */

  177950.   const char *zArg                /* Matchinfo format string */

  177951. ){

  177952.   int rc = SQLITE_OK;

  177953.   int i;

  177954.   Fts3Table *pTab = (Fts3Table *)pCsr->base.pVtab;

  177955.   sqlite3_stmt *pSelect = 0;

  177956. 

  177957.   for(i=0; rc==SQLITE_OK && zArg[i]; i++){

  177958.     pInfo->flag = zArg[i];

  177959.     switch( zArg[i] ){

  177960.       case FTS3_MATCHINFO_NPHRASE:

  177961.         if( bGlobal ) pInfo->aMatchinfo[0] = pInfo->nPhrase;

  177962.         break;

  177963. 

  177964.       case FTS3_MATCHINFO_NCOL:

  177965.         if( bGlobal ) pInfo->aMatchinfo[0] = pInfo->nCol;

  177966.         break;

  177967.         

  177968.       case FTS3_MATCHINFO_NDOC:

  177969.         if( bGlobal ){

  177970.           sqlite3_int64 nDoc = 0;

  177971.           rc = fts3MatchinfoSelectDoctotal(pTab, &pSelect, &nDoc, 0);

  177972.           pInfo->aMatchinfo[0] = (u32)nDoc;

  177973.         }

  177974.         break;

  177975. 

  177976.       case FTS3_MATCHINFO_AVGLENGTH: 

  177977.         if( bGlobal ){

  177978.           sqlite3_int64 nDoc;     /* Number of rows in table */

  177979.           const char *a;          /* Aggregate column length array */

  177980. 

  177981.           rc = fts3MatchinfoSelectDoctotal(pTab, &pSelect, &nDoc, &a);

  177982.           if( rc==SQLITE_OK ){

  177983.             int iCol;

  177984.             for(iCol=0; iCol<pInfo->nCol; iCol++){

  177985.               u32 iVal;

  177986.               sqlite3_int64 nToken;

  177987.               a += sqlite3Fts3GetVarint(a, &nToken);

  177988.               iVal = (u32)(((u32)(nToken&0xffffffff)+nDoc/2)/nDoc);

  177989.               pInfo->aMatchinfo[iCol] = iVal;

  177990.             }

  177991.           }

  177992.         }

  177993.         break;

  177994. 

  177995.       case FTS3_MATCHINFO_LENGTH: {

  177996.         sqlite3_stmt *pSelectDocsize = 0;

  177997.         rc = sqlite3Fts3SelectDocsize(pTab, pCsr->iPrevId, &pSelectDocsize);

  177998.         if( rc==SQLITE_OK ){

  177999.           int iCol;

  178000.           const char *a = sqlite3_column_blob(pSelectDocsize, 0);

  178001.           for(iCol=0; iCol<pInfo->nCol; iCol++){

  178002.             sqlite3_int64 nToken;

  178003.             a += sqlite3Fts3GetVarint(a, &nToken);

  178004.             pInfo->aMatchinfo[iCol] = (u32)nToken;

  178005.           }

  178006.         }

  178007.         sqlite3_reset(pSelectDocsize);

  178008.         break;

  178009.       }

  178010. 

  178011.       case FTS3_MATCHINFO_LCS:

  178012.         rc = fts3ExprLoadDoclists(pCsr, 0, 0);

  178013.         if( rc==SQLITE_OK ){

  178014.           rc = fts3MatchinfoLcs(pCsr, pInfo);

  178015.         }

  178016.         break;

  178017. 

  178018.       case FTS3_MATCHINFO_LHITS_BM:

  178019.       case FTS3_MATCHINFO_LHITS: {

  178020.         size_t nZero = fts3MatchinfoSize(pInfo, zArg[i]) * sizeof(u32);

  178021.         memset(pInfo->aMatchinfo, 0, nZero);

  178022.         rc = fts3ExprLHitGather(pCsr->pExpr, pInfo);

  178023.         break;

  178024.       }

  178025. 

  178026.       default: {

  178027.         Fts3Expr *pExpr;

  178028.         assert( zArg[i]==FTS3_MATCHINFO_HITS );

  178029.         pExpr = pCsr->pExpr;

  178030.         rc = fts3ExprLoadDoclists(pCsr, 0, 0);

  178031.         if( rc!=SQLITE_OK ) break;

  178032.         if( bGlobal ){

  178033.           if( pCsr->pDeferred ){

  178034.             rc = fts3MatchinfoSelectDoctotal(pTab, &pSelect, &pInfo->nDoc, 0);

  178035.             if( rc!=SQLITE_OK ) break;

  178036.           }

  178037.           rc = fts3ExprIterate(pExpr, fts3ExprGlobalHitsCb,(void*)pInfo);

  178038.           sqlite3Fts3EvalTestDeferred(pCsr, &rc);

  178039.           if( rc!=SQLITE_OK ) break;

  178040.         }

  178041.         (void)fts3ExprIterate(pExpr, fts3ExprLocalHitsCb,(void*)pInfo);

  178042.         break;

  178043.       }

  178044.     }

  178045. 

  178046.     pInfo->aMatchinfo += fts3MatchinfoSize(pInfo, zArg[i]);

  178047.   }

  178048. 

  178049.   sqlite3_reset(pSelect);

  178050.   return rc;

  178051. }

  178052. 

  178053. 

  178054. /*

  178055. ** Populate pCsr->aMatchinfo[] with data for the current row. The 

  178056. ** 'matchinfo' data is an array of 32-bit unsigned integers (C type u32).

  178057. */

  178058. static void fts3GetMatchinfo(

  178059.   sqlite3_context *pCtx,        /* Return results here */

  178060.   Fts3Cursor *pCsr,               /* FTS3 Cursor object */

  178061.   const char *zArg                /* Second argument to matchinfo() function */

  178062. ){

  178063.   MatchInfo sInfo;

  178064.   Fts3Table *pTab = (Fts3Table *)pCsr->base.pVtab;

  178065.   int rc = SQLITE_OK;

  178066.   int bGlobal = 0;                /* Collect 'global' stats as well as local */

  178067. 

  178068.   u32 *aOut = 0;

  178069.   void (*xDestroyOut)(void*) = 0;

  178070. 

  178071.   memset(&sInfo, 0, sizeof(MatchInfo));

  178072.   sInfo.pCursor = pCsr;

  178073.   sInfo.nCol = pTab->nColumn;

  178074. 

  178075.   /* If there is cached matchinfo() data, but the format string for the 

  178076.   ** cache does not match the format string for this request, discard 

  178077.   ** the cached data. */

  178078.   if( pCsr->pMIBuffer && strcmp(pCsr->pMIBuffer->zMatchinfo, zArg) ){

  178079.     sqlite3Fts3MIBufferFree(pCsr->pMIBuffer);

  178080.     pCsr->pMIBuffer = 0;

  178081.   }

  178082. 

  178083.   /* If Fts3Cursor.pMIBuffer is NULL, then this is the first time the

  178084.   ** matchinfo function has been called for this query. In this case 

  178085.   ** allocate the array used to accumulate the matchinfo data and

  178086.   ** initialize those elements that are constant for every row.

  178087.   */

  178088.   if( pCsr->pMIBuffer==0 ){

  178089.     size_t nMatchinfo = 0;        /* Number of u32 elements in match-info */

  178090.     int i;                        /* Used to iterate through zArg */

  178091. 

  178092.     /* Determine the number of phrases in the query */

  178093.     pCsr->nPhrase = fts3ExprPhraseCount(pCsr->pExpr);

  178094.     sInfo.nPhrase = pCsr->nPhrase;

  178095. 

  178096.     /* Determine the number of integers in the buffer returned by this call. */

  178097.     for(i=0; zArg[i]; i++){

  178098.       char *zErr = 0;

  178099.       if( fts3MatchinfoCheck(pTab, zArg[i], &zErr) ){

  178100.         sqlite3_result_error(pCtx, zErr, -1);

  178101.         sqlite3_free(zErr);

  178102.         return;

  178103.       }

  178104.       nMatchinfo += fts3MatchinfoSize(&sInfo, zArg[i]);

  178105.     }

  178106. 

  178107.     /* Allocate space for Fts3Cursor.aMatchinfo[] and Fts3Cursor.zMatchinfo. */

  178108.     pCsr->pMIBuffer = fts3MIBufferNew(nMatchinfo, zArg);

  178109.     if( !pCsr->pMIBuffer ) rc = SQLITE_NOMEM;

  178110. 

  178111.     pCsr->isMatchinfoNeeded = 1;

  178112.     bGlobal = 1;

  178113.   }

  178114. 

  178115.   if( rc==SQLITE_OK ){

  178116.     xDestroyOut = fts3MIBufferAlloc(pCsr->pMIBuffer, &aOut);

  178117.     if( xDestroyOut==0 ){

  178118.       rc = SQLITE_NOMEM;

  178119.     }

  178120.   }

  178121. 

  178122.   if( rc==SQLITE_OK ){

  178123.     sInfo.aMatchinfo = aOut;

  178124.     sInfo.nPhrase = pCsr->nPhrase;

  178125.     rc = fts3MatchinfoValues(pCsr, bGlobal, &sInfo, zArg);

  178126.     if( bGlobal ){

  178127.       fts3MIBufferSetGlobal(pCsr->pMIBuffer);

  178128.     }

  178129.   }

  178130. 

  178131.   if( rc!=SQLITE_OK ){

  178132.     sqlite3_result_error_code(pCtx, rc);

  178133.     if( xDestroyOut ) xDestroyOut(aOut);

  178134.   }else{

  178135.     int n = pCsr->pMIBuffer->nElem * sizeof(u32);

  178136.     sqlite3_result_blob(pCtx, aOut, n, xDestroyOut);

  178137.   }

  178138. }

  178139. 

  178140. /*

  178141. ** Implementation of snippet() function.

  178142. */

  178143. SQLITE_PRIVATE void sqlite3Fts3Snippet(

  178144.   sqlite3_context *pCtx,          /* SQLite function call context */

  178145.   Fts3Cursor *pCsr,               /* Cursor object */

  178146.   const char *zStart,             /* Snippet start text - "<b>" */

  178147.   const char *zEnd,               /* Snippet end text - "</b>" */

  178148.   const char *zEllipsis,          /* Snippet ellipsis text - "<b>...</b>" */

  178149.   int iCol,                       /* Extract snippet from this column */

  178150.   int nToken                      /* Approximate number of tokens in snippet */

  178151. ){

  178152.   Fts3Table *pTab = (Fts3Table *)pCsr->base.pVtab;

  178153.   int rc = SQLITE_OK;

  178154.   int i;

  178155.   StrBuffer res = {0, 0, 0};

  178156. 

  178157.   /* The returned text includes up to four fragments of text extracted from

  178158.   ** the data in the current row. The first iteration of the for(...) loop

  178159.   ** below attempts to locate a single fragment of text nToken tokens in 

  178160.   ** size that contains at least one instance of all phrases in the query

  178161.   ** expression that appear in the current row. If such a fragment of text

  178162.   ** cannot be found, the second iteration of the loop attempts to locate

  178163.   ** a pair of fragments, and so on.

  178164.   */

  178165.   int nSnippet = 0;               /* Number of fragments in this snippet */

  178166.   SnippetFragment aSnippet[4];    /* Maximum of 4 fragments per snippet */

  178167.   int nFToken = -1;               /* Number of tokens in each fragment */

  178168. 

  178169.   if( !pCsr->pExpr ){

  178170.     sqlite3_result_text(pCtx, "", 0, SQLITE_STATIC);

  178171.     return;

  178172.   }

  178173. 

  178174.   /* Limit the snippet length to 64 tokens. */

  178175.   if( nToken<-64 ) nToken = -64;

  178176.   if( nToken>+64 ) nToken = +64;

  178177. 

  178178.   for(nSnippet=1; 1; nSnippet++){

  178179. 

  178180.     int iSnip;                    /* Loop counter 0..nSnippet-1 */

  178181.     u64 mCovered = 0;             /* Bitmask of phrases covered by snippet */

  178182.     u64 mSeen = 0;                /* Bitmask of phrases seen by BestSnippet() */

  178183. 

  178184.     if( nToken>=0 ){

  178185.       nFToken = (nToken+nSnippet-1) / nSnippet;

  178186.     }else{

  178187.       nFToken = -1 * nToken;

  178188.     }

  178189. 

  178190.     for(iSnip=0; iSnip<nSnippet; iSnip++){

  178191.       int iBestScore = -1;        /* Best score of columns checked so far */

  178192.       int iRead;                  /* Used to iterate through columns */

  178193.       SnippetFragment *pFragment = &aSnippet[iSnip];

  178194. 

  178195.       memset(pFragment, 0, sizeof(*pFragment));

  178196. 

  178197.       /* Loop through all columns of the table being considered for snippets.

  178198.       ** If the iCol argument to this function was negative, this means all

  178199.       ** columns of the FTS3 table. Otherwise, only column iCol is considered.

  178200.       */

  178201.       for(iRead=0; iRead<pTab->nColumn; iRead++){

  178202.         SnippetFragment sF = {0, 0, 0, 0};

  178203.         int iS = 0;

  178204.         if( iCol>=0 && iRead!=iCol ) continue;

  178205. 

  178206.         /* Find the best snippet of nFToken tokens in column iRead. */

  178207.         rc = fts3BestSnippet(nFToken, pCsr, iRead, mCovered, &mSeen, &sF, &iS);

  178208.         if( rc!=SQLITE_OK ){

  178209.           goto snippet_out;

  178210.         }

  178211.         if( iS>iBestScore ){

  178212.           *pFragment = sF;

  178213.           iBestScore = iS;

  178214.         }

  178215.       }

  178216. 

  178217.       mCovered |= pFragment->covered;

  178218.     }

  178219. 

  178220.     /* If all query phrases seen by fts3BestSnippet() are present in at least

  178221.     ** one of the nSnippet snippet fragments, break out of the loop.

  178222.     */

  178223.     assert( (mCovered&mSeen)==mCovered );

  178224.     if( mSeen==mCovered || nSnippet==SizeofArray(aSnippet) ) break;

  178225.   }

  178226. 

  178227.   assert( nFToken>0 );

  178228. 

  178229.   for(i=0; i<nSnippet && rc==SQLITE_OK; i++){

  178230.     rc = fts3SnippetText(pCsr, &aSnippet[i], 

  178231.         i, (i==nSnippet-1), nFToken, zStart, zEnd, zEllipsis, &res

  178232.     );

  178233.   }

  178234. 

  178235.  snippet_out:

  178236.   sqlite3Fts3SegmentsClose(pTab);

  178237.   if( rc!=SQLITE_OK ){

  178238.     sqlite3_result_error_code(pCtx, rc);

  178239.     sqlite3_free(res.z);

  178240.   }else{

  178241.     sqlite3_result_text(pCtx, res.z, -1, sqlite3_free);

  178242.   }

  178243. }

  178244. 

  178245. 

  178246. typedef struct TermOffset TermOffset;

  178247. typedef struct TermOffsetCtx TermOffsetCtx;

  178248. 

  178249. struct TermOffset {

  178250.   char *pList;                    /* Position-list */

  178251.   int iPos;                       /* Position just read from pList */

  178252.   int iOff;                       /* Offset of this term from read positions */

  178253. };

  178254. 

  178255. struct TermOffsetCtx {

  178256.   Fts3Cursor *pCsr;

  178257.   int iCol;                       /* Column of table to populate aTerm for */

  178258.   int iTerm;

  178259.   sqlite3_int64 iDocid;

  178260.   TermOffset *aTerm;

  178261. };

  178262. 

  178263. /*

  178264. ** This function is an fts3ExprIterate() callback used by sqlite3Fts3Offsets().

  178265. */

  178266. static int fts3ExprTermOffsetInit(Fts3Expr *pExpr, int iPhrase, void *ctx){

  178267.   TermOffsetCtx *p = (TermOffsetCtx *)ctx;

  178268.   int nTerm;                      /* Number of tokens in phrase */

  178269.   int iTerm;                      /* For looping through nTerm phrase terms */

  178270.   char *pList;                    /* Pointer to position list for phrase */

  178271.   int iPos = 0;                   /* First position in position-list */

  178272.   int rc;

  178273. 

  178274.   UNUSED_PARAMETER(iPhrase);

  178275.   rc = sqlite3Fts3EvalPhrasePoslist(p->pCsr, pExpr, p->iCol, &pList);

  178276.   nTerm = pExpr->pPhrase->nToken;

  178277.   if( pList ){

  178278.     fts3GetDeltaPosition(&pList, &iPos);

  178279.     assert_fts3_nc( iPos>=0 );

  178280.   }

  178281. 

  178282.   for(iTerm=0; iTerm<nTerm; iTerm++){

  178283.     TermOffset *pT = &p->aTerm[p->iTerm++];

  178284.     pT->iOff = nTerm-iTerm-1;

  178285.     pT->pList = pList;

  178286.     pT->iPos = iPos;

  178287.   }

  178288. 

  178289.   return rc;

  178290. }

  178291. 

  178292. /*

  178293. ** Implementation of offsets() function.

  178294. */

  178295. SQLITE_PRIVATE void sqlite3Fts3Offsets(

  178296.   sqlite3_context *pCtx,          /* SQLite function call context */

  178297.   Fts3Cursor *pCsr                /* Cursor object */

  178298. ){

  178299.   Fts3Table *pTab = (Fts3Table *)pCsr->base.pVtab;

  178300.   sqlite3_tokenizer_module const *pMod = pTab->pTokenizer->pModule;

  178301.   int rc;                         /* Return Code */

  178302.   int nToken;                     /* Number of tokens in query */

  178303.   int iCol;                       /* Column currently being processed */

  178304.   StrBuffer res = {0, 0, 0};      /* Result string */

  178305.   TermOffsetCtx sCtx;             /* Context for fts3ExprTermOffsetInit() */

  178306. 

  178307.   if( !pCsr->pExpr ){

  178308.     sqlite3_result_text(pCtx, "", 0, SQLITE_STATIC);

  178309.     return;

  178310.   }

  178311. 

  178312.   memset(&sCtx, 0, sizeof(sCtx));

  178313.   assert( pCsr->isRequireSeek==0 );

  178314. 

  178315.   /* Count the number of terms in the query */

  178316.   rc = fts3ExprLoadDoclists(pCsr, 0, &nToken);

  178317.   if( rc!=SQLITE_OK ) goto offsets_out;

  178318. 

  178319.   /* Allocate the array of TermOffset iterators. */

  178320.   sCtx.aTerm = (TermOffset *)sqlite3_malloc64(sizeof(TermOffset)*nToken);

  178321.   if( 0==sCtx.aTerm ){

  178322.     rc = SQLITE_NOMEM;

  178323.     goto offsets_out;

  178324.   }

  178325.   sCtx.iDocid = pCsr->iPrevId;

  178326.   sCtx.pCsr = pCsr;

  178327. 

  178328.   /* Loop through the table columns, appending offset information to 

  178329.   ** string-buffer res for each column.

  178330.   */

  178331.   for(iCol=0; iCol<pTab->nColumn; iCol++){

  178332.     sqlite3_tokenizer_cursor *pC; /* Tokenizer cursor */

  178333.     const char *ZDUMMY;           /* Dummy argument used with xNext() */

  178334.     int NDUMMY = 0;               /* Dummy argument used with xNext() */

  178335.     int iStart = 0;

  178336.     int iEnd = 0;

  178337.     int iCurrent = 0;

  178338.     const char *zDoc;

  178339.     int nDoc;

  178340. 

  178341.     /* Initialize the contents of sCtx.aTerm[] for column iCol. There is 

  178342.     ** no way that this operation can fail, so the return code from

  178343.     ** fts3ExprIterate() can be discarded.

  178344.     */

  178345.     sCtx.iCol = iCol;

  178346.     sCtx.iTerm = 0;

  178347.     (void)fts3ExprIterate(pCsr->pExpr, fts3ExprTermOffsetInit, (void*)&sCtx);

  178348. 

  178349.     /* Retreive the text stored in column iCol. If an SQL NULL is stored 

  178350.     ** in column iCol, jump immediately to the next iteration of the loop.

  178351.     ** If an OOM occurs while retrieving the data (this can happen if SQLite

  178352.     ** needs to transform the data from utf-16 to utf-8), return SQLITE_NOMEM 

  178353.     ** to the caller. 

  178354.     */

  178355.     zDoc = (const char *)sqlite3_column_text(pCsr->pStmt, iCol+1);

  178356.     nDoc = sqlite3_column_bytes(pCsr->pStmt, iCol+1);

  178357.     if( zDoc==0 ){

  178358.       if( sqlite3_column_type(pCsr->pStmt, iCol+1)==SQLITE_NULL ){

  178359.         continue;

  178360.       }

  178361.       rc = SQLITE_NOMEM;

  178362.       goto offsets_out;

  178363.     }

  178364. 

  178365.     /* Initialize a tokenizer iterator to iterate through column iCol. */

  178366.     rc = sqlite3Fts3OpenTokenizer(pTab->pTokenizer, pCsr->iLangid,

  178367.         zDoc, nDoc, &pC

  178368.     );

  178369.     if( rc!=SQLITE_OK ) goto offsets_out;

  178370. 

  178371.     rc = pMod->xNext(pC, &ZDUMMY, &NDUMMY, &iStart, &iEnd, &iCurrent);

  178372.     while( rc==SQLITE_OK ){

  178373.       int i;                      /* Used to loop through terms */

  178374.       int iMinPos = 0x7FFFFFFF;   /* Position of next token */

  178375.       TermOffset *pTerm = 0;      /* TermOffset associated with next token */

  178376. 

  178377.       for(i=0; i<nToken; i++){

  178378.         TermOffset *pT = &sCtx.aTerm[i];

  178379.         if( pT->pList && (pT->iPos-pT->iOff)<iMinPos ){

  178380.           iMinPos = pT->iPos-pT->iOff;

  178381.           pTerm = pT;

  178382.         }

  178383.       }

  178384. 

  178385.       if( !pTerm ){

  178386.         /* All offsets for this column have been gathered. */

  178387.         rc = SQLITE_DONE;

  178388.       }else{

  178389.         assert_fts3_nc( iCurrent<=iMinPos );

  178390.         if( 0==(0xFE&*pTerm->pList) ){

  178391.           pTerm->pList = 0;

  178392.         }else{

  178393.           fts3GetDeltaPosition(&pTerm->pList, &pTerm->iPos);

  178394.         }

  178395.         while( rc==SQLITE_OK && iCurrent<iMinPos ){

  178396.           rc = pMod->xNext(pC, &ZDUMMY, &NDUMMY, &iStart, &iEnd, &iCurrent);

  178397.         }

  178398.         if( rc==SQLITE_OK ){

  178399.           char aBuffer[64];

  178400.           sqlite3_snprintf(sizeof(aBuffer), aBuffer, 

  178401.               "%d %d %d %d ", iCol, pTerm-sCtx.aTerm, iStart, iEnd-iStart

  178402.           );

  178403.           rc = fts3StringAppend(&res, aBuffer, -1);

  178404.         }else if( rc==SQLITE_DONE && pTab->zContentTbl==0 ){

  178405.           rc = FTS_CORRUPT_VTAB;

  178406.         }

  178407.       }

  178408.     }

  178409.     if( rc==SQLITE_DONE ){

  178410.       rc = SQLITE_OK;

  178411.     }

  178412. 

  178413.     pMod->xClose(pC);

  178414.     if( rc!=SQLITE_OK ) goto offsets_out;

  178415.   }

  178416. 

  178417.  offsets_out:

  178418.   sqlite3_free(sCtx.aTerm);

  178419.   assert( rc!=SQLITE_DONE );

  178420.   sqlite3Fts3SegmentsClose(pTab);

  178421.   if( rc!=SQLITE_OK ){

  178422.     sqlite3_result_error_code(pCtx,  rc);

  178423.     sqlite3_free(res.z);

  178424.   }else{

  178425.     sqlite3_result_text(pCtx, res.z, res.n-1, sqlite3_free);

  178426.   }

  178427.   return;

  178428. }

  178429. 

  178430. /*

  178431. ** Implementation of matchinfo() function.

  178432. */

  178433. SQLITE_PRIVATE void sqlite3Fts3Matchinfo(

  178434.   sqlite3_context *pContext,      /* Function call context */

  178435.   Fts3Cursor *pCsr,               /* FTS3 table cursor */

  178436.   const char *zArg                /* Second arg to matchinfo() function */

  178437. ){

  178438.   Fts3Table *pTab = (Fts3Table *)pCsr->base.pVtab;

  178439.   const char *zFormat;

  178440. 

  178441.   if( zArg ){

  178442.     zFormat = zArg;

  178443.   }else{

  178444.     zFormat = FTS3_MATCHINFO_DEFAULT;

  178445.   }

  178446. 

  178447.   if( !pCsr->pExpr ){

  178448.     sqlite3_result_blob(pContext, "", 0, SQLITE_STATIC);

  178449.     return;

  178450.   }else{

  178451.     /* Retrieve matchinfo() data. */

  178452.     fts3GetMatchinfo(pContext, pCsr, zFormat);

  178453.     sqlite3Fts3SegmentsClose(pTab);

  178454.   }

  178455. }

  178456. 

  178457. #endif

  178458. 

  178459. /************** End of fts3_snippet.c ****************************************/

  178460. /************** Begin file fts3_unicode.c ************************************/

  178461. /*

  178462. ** 2012 May 24

  178463. **

  178464. ** The author disclaims copyright to this source code.  In place of

  178465. ** a legal notice, here is a blessing:

  178466. **

  178467. **    May you do good and not evil.

  178468. **    May you find forgiveness for yourself and forgive others.

  178469. **    May you share freely, never taking more than you give.

  178470. **

  178471. ******************************************************************************

  178472. **

  178473. ** Implementation of the "unicode" full-text-search tokenizer.

  178474. */

  178475. 

  178476. #ifndef SQLITE_DISABLE_FTS3_UNICODE

  178477. 

  178478. /* #include "fts3Int.h" */

  178479. #if !defined(SQLITE_CORE) || defined(SQLITE_ENABLE_FTS3)

  178480. 

  178481. /* #include <assert.h> */

  178482. /* #include <stdlib.h> */

  178483. /* #include <stdio.h> */

  178484. /* #include <string.h> */

  178485. 

  178486. /* #include "fts3_tokenizer.h" */

  178487. 

  178488. /*

  178489. ** The following two macros - READ_UTF8 and WRITE_UTF8 - have been copied

  178490. ** from the sqlite3 source file utf.c. If this file is compiled as part

  178491. ** of the amalgamation, they are not required.

  178492. */

  178493. #ifndef SQLITE_AMALGAMATION

  178494. 

  178495. static const unsigned char sqlite3Utf8Trans1[] = {

  178496.   0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07,

  178497.   0x08, 0x09, 0x0a, 0x0b, 0x0c, 0x0d, 0x0e, 0x0f,

  178498.   0x10, 0x11, 0x12, 0x13, 0x14, 0x15, 0x16, 0x17,

  178499.   0x18, 0x19, 0x1a, 0x1b, 0x1c, 0x1d, 0x1e, 0x1f,

  178500.   0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07,

  178501.   0x08, 0x09, 0x0a, 0x0b, 0x0c, 0x0d, 0x0e, 0x0f,

  178502.   0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07,

  178503.   0x00, 0x01, 0x02, 0x03, 0x00, 0x01, 0x00, 0x00,

  178504. };

  178505. 

  178506. #define READ_UTF8(zIn, zTerm, c)                           \

  178507.   c = *(zIn++);                                            \

  178508.   if( c>=0xc0 ){                                           \

  178509.     c = sqlite3Utf8Trans1[c-0xc0];                         \

  178510.     while( zIn!=zTerm && (*zIn & 0xc0)==0x80 ){            \

  178511.       c = (c<<6) + (0x3f & *(zIn++));                      \

  178512.     }                                                      \

  178513.     if( c<0x80                                             \

  178514.         || (c&0xFFFFF800)==0xD800                          \

  178515.         || (c&0xFFFFFFFE)==0xFFFE ){  c = 0xFFFD; }        \

  178516.   }

  178517. 

  178518. #define WRITE_UTF8(zOut, c) {                          \

  178519.   if( c<0x00080 ){                                     \

  178520.     *zOut++ = (u8)(c&0xFF);                            \

  178521.   }                                                    \

  178522.   else if( c<0x00800 ){                                \

  178523.     *zOut++ = 0xC0 + (u8)((c>>6)&0x1F);                \

  178524.     *zOut++ = 0x80 + (u8)(c & 0x3F);                   \

  178525.   }                                                    \

  178526.   else if( c<0x10000 ){                                \

  178527.     *zOut++ = 0xE0 + (u8)((c>>12)&0x0F);               \

  178528.     *zOut++ = 0x80 + (u8)((c>>6) & 0x3F);              \

  178529.     *zOut++ = 0x80 + (u8)(c & 0x3F);                   \

  178530.   }else{                                               \

  178531.     *zOut++ = 0xF0 + (u8)((c>>18) & 0x07);             \

  178532.     *zOut++ = 0x80 + (u8)((c>>12) & 0x3F);             \

  178533.     *zOut++ = 0x80 + (u8)((c>>6) & 0x3F);              \

  178534.     *zOut++ = 0x80 + (u8)(c & 0x3F);                   \

  178535.   }                                                    \

  178536. }

  178537. 

  178538. #endif /* ifndef SQLITE_AMALGAMATION */

  178539. 

  178540. typedef struct unicode_tokenizer unicode_tokenizer;

  178541. typedef struct unicode_cursor unicode_cursor;

  178542. 

  178543. struct unicode_tokenizer {

  178544.   sqlite3_tokenizer base;

  178545.   int eRemoveDiacritic;

  178546.   int nException;

  178547.   int *aiException;

  178548. };

  178549. 

  178550. struct unicode_cursor {

  178551.   sqlite3_tokenizer_cursor base;

  178552.   const unsigned char *aInput;    /* Input text being tokenized */

  178553.   int nInput;                     /* Size of aInput[] in bytes */

  178554.   int iOff;                       /* Current offset within aInput[] */

  178555.   int iToken;                     /* Index of next token to be returned */

  178556.   char *zToken;                   /* storage for current token */

  178557.   int nAlloc;                     /* space allocated at zToken */

  178558. };

  178559. 

  178560. 

  178561. /*

  178562. ** Destroy a tokenizer allocated by unicodeCreate().

  178563. */

  178564. static int unicodeDestroy(sqlite3_tokenizer *pTokenizer){

  178565.   if( pTokenizer ){

  178566.     unicode_tokenizer *p = (unicode_tokenizer *)pTokenizer;

  178567.     sqlite3_free(p->aiException);

  178568.     sqlite3_free(p);

  178569.   }

  178570.   return SQLITE_OK;

  178571. }

  178572. 

  178573. /*

  178574. ** As part of a tokenchars= or separators= option, the CREATE VIRTUAL TABLE

  178575. ** statement has specified that the tokenizer for this table shall consider

  178576. ** all characters in string zIn/nIn to be separators (if bAlnum==0) or

  178577. ** token characters (if bAlnum==1).

  178578. **

  178579. ** For each codepoint in the zIn/nIn string, this function checks if the

  178580. ** sqlite3FtsUnicodeIsalnum() function already returns the desired result.

  178581. ** If so, no action is taken. Otherwise, the codepoint is added to the 

  178582. ** unicode_tokenizer.aiException[] array. For the purposes of tokenization,

  178583. ** the return value of sqlite3FtsUnicodeIsalnum() is inverted for all

  178584. ** codepoints in the aiException[] array.

  178585. **

  178586. ** If a standalone diacritic mark (one that sqlite3FtsUnicodeIsdiacritic()

  178587. ** identifies as a diacritic) occurs in the zIn/nIn string it is ignored.

  178588. ** It is not possible to change the behavior of the tokenizer with respect

  178589. ** to these codepoints.

  178590. */

  178591. static int unicodeAddExceptions(

  178592.   unicode_tokenizer *p,           /* Tokenizer to add exceptions to */

  178593.   int bAlnum,                     /* Replace Isalnum() return value with this */

  178594.   const char *zIn,                /* Array of characters to make exceptions */

  178595.   int nIn                         /* Length of z in bytes */

  178596. ){

  178597.   const unsigned char *z = (const unsigned char *)zIn;

  178598.   const unsigned char *zTerm = &z[nIn];

  178599.   unsigned int iCode;

  178600.   int nEntry = 0;

  178601. 

  178602.   assert( bAlnum==0 || bAlnum==1 );

  178603. 

  178604.   while( z<zTerm ){

  178605.     READ_UTF8(z, zTerm, iCode);

  178606.     assert( (sqlite3FtsUnicodeIsalnum((int)iCode) & 0xFFFFFFFE)==0 );

  178607.     if( sqlite3FtsUnicodeIsalnum((int)iCode)!=bAlnum 

  178608.      && sqlite3FtsUnicodeIsdiacritic((int)iCode)==0 

  178609.     ){

  178610.       nEntry++;

  178611.     }

  178612.   }

  178613. 

  178614.   if( nEntry ){

  178615.     int *aNew;                    /* New aiException[] array */

  178616.     int nNew;                     /* Number of valid entries in array aNew[] */

  178617. 

  178618.     aNew = sqlite3_realloc64(p->aiException,(p->nException+nEntry)*sizeof(int));

  178619.     if( aNew==0 ) return SQLITE_NOMEM;

  178620.     nNew = p->nException;

  178621. 

  178622.     z = (const unsigned char *)zIn;

  178623.     while( z<zTerm ){

  178624.       READ_UTF8(z, zTerm, iCode);

  178625.       if( sqlite3FtsUnicodeIsalnum((int)iCode)!=bAlnum 

  178626.        && sqlite3FtsUnicodeIsdiacritic((int)iCode)==0

  178627.       ){

  178628.         int i, j;

  178629.         for(i=0; i<nNew && aNew[i]<(int)iCode; i++);

  178630.         for(j=nNew; j>i; j--) aNew[j] = aNew[j-1];

  178631.         aNew[i] = (int)iCode;

  178632.         nNew++;

  178633.       }

  178634.     }

  178635.     p->aiException = aNew;

  178636.     p->nException = nNew;

  178637.   }

  178638. 

  178639.   return SQLITE_OK;

  178640. }

  178641. 

  178642. /*

  178643. ** Return true if the p->aiException[] array contains the value iCode.

  178644. */

  178645. static int unicodeIsException(unicode_tokenizer *p, int iCode){

  178646.   if( p->nException>0 ){

  178647.     int *a = p->aiException;

  178648.     int iLo = 0;

  178649.     int iHi = p->nException-1;

  178650. 

  178651.     while( iHi>=iLo ){

  178652.       int iTest = (iHi + iLo) / 2;

  178653.       if( iCode==a[iTest] ){

  178654.         return 1;

  178655.       }else if( iCode>a[iTest] ){

  178656.         iLo = iTest+1;

  178657.       }else{

  178658.         iHi = iTest-1;

  178659.       }

  178660.     }

  178661.   }

  178662. 

  178663.   return 0;

  178664. }

  178665. 

  178666. /*

  178667. ** Return true if, for the purposes of tokenization, codepoint iCode is

  178668. ** considered a token character (not a separator).

  178669. */

  178670. static int unicodeIsAlnum(unicode_tokenizer *p, int iCode){

  178671.   assert( (sqlite3FtsUnicodeIsalnum(iCode) & 0xFFFFFFFE)==0 );

  178672.   return sqlite3FtsUnicodeIsalnum(iCode) ^ unicodeIsException(p, iCode);

  178673. }

  178674. 

  178675. /*

  178676. ** Create a new tokenizer instance.

  178677. */

  178678. static int unicodeCreate(

  178679.   int nArg,                       /* Size of array argv[] */

  178680.   const char * const *azArg,      /* Tokenizer creation arguments */

  178681.   sqlite3_tokenizer **pp          /* OUT: New tokenizer handle */

  178682. ){

  178683.   unicode_tokenizer *pNew;        /* New tokenizer object */

  178684.   int i;

  178685.   int rc = SQLITE_OK;

  178686. 

  178687.   pNew = (unicode_tokenizer *) sqlite3_malloc(sizeof(unicode_tokenizer));

  178688.   if( pNew==NULL ) return SQLITE_NOMEM;

  178689.   memset(pNew, 0, sizeof(unicode_tokenizer));

  178690.   pNew->eRemoveDiacritic = 1;

  178691. 

  178692.   for(i=0; rc==SQLITE_OK && i<nArg; i++){

  178693.     const char *z = azArg[i];

  178694.     int n = (int)strlen(z);

  178695. 

  178696.     if( n==19 && memcmp("remove_diacritics=1", z, 19)==0 ){

  178697.       pNew->eRemoveDiacritic = 1;

  178698.     }

  178699.     else if( n==19 && memcmp("remove_diacritics=0", z, 19)==0 ){

  178700.       pNew->eRemoveDiacritic = 0;

  178701.     }

  178702.     else if( n==19 && memcmp("remove_diacritics=2", z, 19)==0 ){

  178703.       pNew->eRemoveDiacritic = 2;

  178704.     }

  178705.     else if( n>=11 && memcmp("tokenchars=", z, 11)==0 ){

  178706.       rc = unicodeAddExceptions(pNew, 1, &z[11], n-11);

  178707.     }

  178708.     else if( n>=11 && memcmp("separators=", z, 11)==0 ){

  178709.       rc = unicodeAddExceptions(pNew, 0, &z[11], n-11);

  178710.     }

  178711.     else{

  178712.       /* Unrecognized argument */

  178713.       rc  = SQLITE_ERROR;

  178714.     }

  178715.   }

  178716. 

  178717.   if( rc!=SQLITE_OK ){

  178718.     unicodeDestroy((sqlite3_tokenizer *)pNew);

  178719.     pNew = 0;

  178720.   }

  178721.   *pp = (sqlite3_tokenizer *)pNew;

  178722.   return rc;

  178723. }

  178724. 

  178725. /*

  178726. ** Prepare to begin tokenizing a particular string.  The input

  178727. ** string to be tokenized is pInput[0..nBytes-1].  A cursor

  178728. ** used to incrementally tokenize this string is returned in 

  178729. ** *ppCursor.

  178730. */

  178731. static int unicodeOpen(

  178732.   sqlite3_tokenizer *p,           /* The tokenizer */

  178733.   const char *aInput,             /* Input string */

  178734.   int nInput,                     /* Size of string aInput in bytes */

  178735.   sqlite3_tokenizer_cursor **pp   /* OUT: New cursor object */

  178736. ){

  178737.   unicode_cursor *pCsr;

  178738. 

  178739.   pCsr = (unicode_cursor *)sqlite3_malloc(sizeof(unicode_cursor));

  178740.   if( pCsr==0 ){

  178741.     return SQLITE_NOMEM;

  178742.   }

  178743.   memset(pCsr, 0, sizeof(unicode_cursor));

  178744. 

  178745.   pCsr->aInput = (const unsigned char *)aInput;

  178746.   if( aInput==0 ){

  178747.     pCsr->nInput = 0;

  178748.   }else if( nInput<0 ){

  178749.     pCsr->nInput = (int)strlen(aInput);

  178750.   }else{

  178751.     pCsr->nInput = nInput;

  178752.   }

  178753. 

  178754.   *pp = &pCsr->base;

  178755.   UNUSED_PARAMETER(p);

  178756.   return SQLITE_OK;

  178757. }

  178758. 

  178759. /*

  178760. ** Close a tokenization cursor previously opened by a call to

  178761. ** simpleOpen() above.

  178762. */

  178763. static int unicodeClose(sqlite3_tokenizer_cursor *pCursor){

  178764.   unicode_cursor *pCsr = (unicode_cursor *) pCursor;

  178765.   sqlite3_free(pCsr->zToken);

  178766.   sqlite3_free(pCsr);

  178767.   return SQLITE_OK;

  178768. }

  178769. 

  178770. /*

  178771. ** Extract the next token from a tokenization cursor.  The cursor must

  178772. ** have been opened by a prior call to simpleOpen().

  178773. */

  178774. static int unicodeNext(

  178775.   sqlite3_tokenizer_cursor *pC,   /* Cursor returned by simpleOpen */

  178776.   const char **paToken,           /* OUT: Token text */

  178777.   int *pnToken,                   /* OUT: Number of bytes at *paToken */

  178778.   int *piStart,                   /* OUT: Starting offset of token */

  178779.   int *piEnd,                     /* OUT: Ending offset of token */

  178780.   int *piPos                      /* OUT: Position integer of token */

  178781. ){

  178782.   unicode_cursor *pCsr = (unicode_cursor *)pC;

  178783.   unicode_tokenizer *p = ((unicode_tokenizer *)pCsr->base.pTokenizer);

  178784.   unsigned int iCode = 0;

  178785.   char *zOut;

  178786.   const unsigned char *z = &pCsr->aInput[pCsr->iOff];

  178787.   const unsigned char *zStart = z;

  178788.   const unsigned char *zEnd;

  178789.   const unsigned char *zTerm = &pCsr->aInput[pCsr->nInput];

  178790. 

  178791.   /* Scan past any delimiter characters before the start of the next token.

  178792.   ** Return SQLITE_DONE early if this takes us all the way to the end of 

  178793.   ** the input.  */

  178794.   while( z<zTerm ){

  178795.     READ_UTF8(z, zTerm, iCode);

  178796.     if( unicodeIsAlnum(p, (int)iCode) ) break;

  178797.     zStart = z;

  178798.   }

  178799.   if( zStart>=zTerm ) return SQLITE_DONE;

  178800. 

  178801.   zOut = pCsr->zToken;

  178802.   do {

  178803.     int iOut;

  178804. 

  178805.     /* Grow the output buffer if required. */

  178806.     if( (zOut-pCsr->zToken)>=(pCsr->nAlloc-4) ){

  178807.       char *zNew = sqlite3_realloc64(pCsr->zToken, pCsr->nAlloc+64);

  178808.       if( !zNew ) return SQLITE_NOMEM;

  178809.       zOut = &zNew[zOut - pCsr->zToken];

  178810.       pCsr->zToken = zNew;

  178811.       pCsr->nAlloc += 64;

  178812.     }

  178813. 

  178814.     /* Write the folded case of the last character read to the output */

  178815.     zEnd = z;

  178816.     iOut = sqlite3FtsUnicodeFold((int)iCode, p->eRemoveDiacritic);

  178817.     if( iOut ){

  178818.       WRITE_UTF8(zOut, iOut);

  178819.     }

  178820. 

  178821.     /* If the cursor is not at EOF, read the next character */

  178822.     if( z>=zTerm ) break;

  178823.     READ_UTF8(z, zTerm, iCode);

  178824.   }while( unicodeIsAlnum(p, (int)iCode) 

  178825.        || sqlite3FtsUnicodeIsdiacritic((int)iCode)

  178826.   );

  178827. 

  178828.   /* Set the output variables and return. */

  178829.   pCsr->iOff = (int)(z - pCsr->aInput);

  178830.   *paToken = pCsr->zToken;

  178831.   *pnToken = (int)(zOut - pCsr->zToken);

  178832.   *piStart = (int)(zStart - pCsr->aInput);

  178833.   *piEnd = (int)(zEnd - pCsr->aInput);

  178834.   *piPos = pCsr->iToken++;

  178835.   return SQLITE_OK;

  178836. }

  178837. 

  178838. /*

  178839. ** Set *ppModule to a pointer to the sqlite3_tokenizer_module 

  178840. ** structure for the unicode tokenizer.

  178841. */

  178842. SQLITE_PRIVATE void sqlite3Fts3UnicodeTokenizer(sqlite3_tokenizer_module const **ppModule){

  178843.   static const sqlite3_tokenizer_module module = {

  178844.     0,

  178845.     unicodeCreate,

  178846.     unicodeDestroy,

  178847.     unicodeOpen,

  178848.     unicodeClose,

  178849.     unicodeNext,

  178850.     0,

  178851.   };

  178852.   *ppModule = &module;

  178853. }

  178854. 

  178855. #endif /* !defined(SQLITE_CORE) || defined(SQLITE_ENABLE_FTS3) */

  178856. #endif /* ifndef SQLITE_DISABLE_FTS3_UNICODE */

  178857. 

  178858. /************** End of fts3_unicode.c ****************************************/

  178859. /************** Begin file fts3_unicode2.c ***********************************/

  178860. /*

  178861. ** 2012-05-25

  178862. **

  178863. ** The author disclaims copyright to this source code.  In place of

  178864. ** a legal notice, here is a blessing:

  178865. **

  178866. **    May you do good and not evil.

  178867. **    May you find forgiveness for yourself and forgive others.

  178868. **    May you share freely, never taking more than you give.

  178869. **

  178870. ******************************************************************************

  178871. */

  178872. 

  178873. /*

  178874. ** DO NOT EDIT THIS MACHINE GENERATED FILE.

  178875. */

  178876. 

  178877. #ifndef SQLITE_DISABLE_FTS3_UNICODE

  178878. #if defined(SQLITE_ENABLE_FTS3) || defined(SQLITE_ENABLE_FTS4)

  178879. 

  178880. /* #include <assert.h> */

  178881. 

  178882. /*

  178883. ** Return true if the argument corresponds to a unicode codepoint

  178884. ** classified as either a letter or a number. Otherwise false.

  178885. **

  178886. ** The results are undefined if the value passed to this function

  178887. ** is less than zero.

  178888. */

  178889. SQLITE_PRIVATE int sqlite3FtsUnicodeIsalnum(int c){

  178890.   /* Each unsigned integer in the following array corresponds to a contiguous

  178891.   ** range of unicode codepoints that are not either letters or numbers (i.e.

  178892.   ** codepoints for which this function should return 0).

  178893.   **

  178894.   ** The most significant 22 bits in each 32-bit value contain the first 

  178895.   ** codepoint in the range. The least significant 10 bits are used to store

  178896.   ** the size of the range (always at least 1). In other words, the value 

  178897.   ** ((C<<22) + N) represents a range of N codepoints starting with codepoint 

  178898.   ** C. It is not possible to represent a range larger than 1023 codepoints 

  178899.   ** using this format.

  178900.   */

  178901.   static const unsigned int aEntry[] = {

  178902.     0x00000030, 0x0000E807, 0x00016C06, 0x0001EC2F, 0x0002AC07,

  178903.     0x0002D001, 0x0002D803, 0x0002EC01, 0x0002FC01, 0x00035C01,

  178904.     0x0003DC01, 0x000B0804, 0x000B480E, 0x000B9407, 0x000BB401,

  178905.     0x000BBC81, 0x000DD401, 0x000DF801, 0x000E1002, 0x000E1C01,

  178906.     0x000FD801, 0x00120808, 0x00156806, 0x00162402, 0x00163C01,

  178907.     0x00164437, 0x0017CC02, 0x00180005, 0x00181816, 0x00187802,

  178908.     0x00192C15, 0x0019A804, 0x0019C001, 0x001B5001, 0x001B580F,

  178909.     0x001B9C07, 0x001BF402, 0x001C000E, 0x001C3C01, 0x001C4401,

  178910.     0x001CC01B, 0x001E980B, 0x001FAC09, 0x001FD804, 0x00205804,

  178911.     0x00206C09, 0x00209403, 0x0020A405, 0x0020C00F, 0x00216403,

  178912.     0x00217801, 0x0023901B, 0x00240004, 0x0024E803, 0x0024F812,

  178913.     0x00254407, 0x00258804, 0x0025C001, 0x00260403, 0x0026F001,

  178914.     0x0026F807, 0x00271C02, 0x00272C03, 0x00275C01, 0x00278802,

  178915.     0x0027C802, 0x0027E802, 0x00280403, 0x0028F001, 0x0028F805,

  178916.     0x00291C02, 0x00292C03, 0x00294401, 0x0029C002, 0x0029D401,

  178917.     0x002A0403, 0x002AF001, 0x002AF808, 0x002B1C03, 0x002B2C03,

  178918.     0x002B8802, 0x002BC002, 0x002C0403, 0x002CF001, 0x002CF807,

  178919.     0x002D1C02, 0x002D2C03, 0x002D5802, 0x002D8802, 0x002DC001,

  178920.     0x002E0801, 0x002EF805, 0x002F1803, 0x002F2804, 0x002F5C01,

  178921.     0x002FCC08, 0x00300403, 0x0030F807, 0x00311803, 0x00312804,

  178922.     0x00315402, 0x00318802, 0x0031FC01, 0x00320802, 0x0032F001,

  178923.     0x0032F807, 0x00331803, 0x00332804, 0x00335402, 0x00338802,

  178924.     0x00340802, 0x0034F807, 0x00351803, 0x00352804, 0x00355C01,

  178925.     0x00358802, 0x0035E401, 0x00360802, 0x00372801, 0x00373C06,

  178926.     0x00375801, 0x00376008, 0x0037C803, 0x0038C401, 0x0038D007,

  178927.     0x0038FC01, 0x00391C09, 0x00396802, 0x003AC401, 0x003AD006,

  178928.     0x003AEC02, 0x003B2006, 0x003C041F, 0x003CD00C, 0x003DC417,

  178929.     0x003E340B, 0x003E6424, 0x003EF80F, 0x003F380D, 0x0040AC14,

  178930.     0x00412806, 0x00415804, 0x00417803, 0x00418803, 0x00419C07,

  178931.     0x0041C404, 0x0042080C, 0x00423C01, 0x00426806, 0x0043EC01,

  178932.     0x004D740C, 0x004E400A, 0x00500001, 0x0059B402, 0x005A0001,

  178933.     0x005A6C02, 0x005BAC03, 0x005C4803, 0x005CC805, 0x005D4802,

  178934.     0x005DC802, 0x005ED023, 0x005F6004, 0x005F7401, 0x0060000F,

  178935.     0x0062A401, 0x0064800C, 0x0064C00C, 0x00650001, 0x00651002,

  178936.     0x0066C011, 0x00672002, 0x00677822, 0x00685C05, 0x00687802,

  178937.     0x0069540A, 0x0069801D, 0x0069FC01, 0x006A8007, 0x006AA006,

  178938.     0x006C0005, 0x006CD011, 0x006D6823, 0x006E0003, 0x006E840D,

  178939.     0x006F980E, 0x006FF004, 0x00709014, 0x0070EC05, 0x0071F802,

  178940.     0x00730008, 0x00734019, 0x0073B401, 0x0073C803, 0x00770027,

  178941.     0x0077F004, 0x007EF401, 0x007EFC03, 0x007F3403, 0x007F7403,

  178942.     0x007FB403, 0x007FF402, 0x00800065, 0x0081A806, 0x0081E805,

  178943.     0x00822805, 0x0082801A, 0x00834021, 0x00840002, 0x00840C04,

  178944.     0x00842002, 0x00845001, 0x00845803, 0x00847806, 0x00849401,

  178945.     0x00849C01, 0x0084A401, 0x0084B801, 0x0084E802, 0x00850005,

  178946.     0x00852804, 0x00853C01, 0x00864264, 0x00900027, 0x0091000B,

  178947.     0x0092704E, 0x00940200, 0x009C0475, 0x009E53B9, 0x00AD400A,

  178948.     0x00B39406, 0x00B3BC03, 0x00B3E404, 0x00B3F802, 0x00B5C001,

  178949.     0x00B5FC01, 0x00B7804F, 0x00B8C00C, 0x00BA001A, 0x00BA6C59,

  178950.     0x00BC00D6, 0x00BFC00C, 0x00C00005, 0x00C02019, 0x00C0A807,

  178951.     0x00C0D802, 0x00C0F403, 0x00C26404, 0x00C28001, 0x00C3EC01,

  178952.     0x00C64002, 0x00C6580A, 0x00C70024, 0x00C8001F, 0x00C8A81E,

  178953.     0x00C94001, 0x00C98020, 0x00CA2827, 0x00CB003F, 0x00CC0100,

  178954.     0x01370040, 0x02924037, 0x0293F802, 0x02983403, 0x0299BC10,

  178955.     0x029A7C01, 0x029BC008, 0x029C0017, 0x029C8002, 0x029E2402,

  178956.     0x02A00801, 0x02A01801, 0x02A02C01, 0x02A08C09, 0x02A0D804,

  178957.     0x02A1D004, 0x02A20002, 0x02A2D011, 0x02A33802, 0x02A38012,

  178958.     0x02A3E003, 0x02A4980A, 0x02A51C0D, 0x02A57C01, 0x02A60004,

  178959.     0x02A6CC1B, 0x02A77802, 0x02A8A40E, 0x02A90C01, 0x02A93002,

  178960.     0x02A97004, 0x02A9DC03, 0x02A9EC01, 0x02AAC001, 0x02AAC803,

  178961.     0x02AADC02, 0x02AAF802, 0x02AB0401, 0x02AB7802, 0x02ABAC07,

  178962.     0x02ABD402, 0x02AF8C0B, 0x03600001, 0x036DFC02, 0x036FFC02,

  178963.     0x037FFC01, 0x03EC7801, 0x03ECA401, 0x03EEC810, 0x03F4F802,

  178964.     0x03F7F002, 0x03F8001A, 0x03F88007, 0x03F8C023, 0x03F95013,

  178965.     0x03F9A004, 0x03FBFC01, 0x03FC040F, 0x03FC6807, 0x03FCEC06,

  178966.     0x03FD6C0B, 0x03FF8007, 0x03FFA007, 0x03FFE405, 0x04040003,

  178967.     0x0404DC09, 0x0405E411, 0x0406400C, 0x0407402E, 0x040E7C01,

  178968.     0x040F4001, 0x04215C01, 0x04247C01, 0x0424FC01, 0x04280403,

  178969.     0x04281402, 0x04283004, 0x0428E003, 0x0428FC01, 0x04294009,

  178970.     0x0429FC01, 0x042CE407, 0x04400003, 0x0440E016, 0x04420003,

  178971.     0x0442C012, 0x04440003, 0x04449C0E, 0x04450004, 0x04460003,

  178972.     0x0446CC0E, 0x04471404, 0x045AAC0D, 0x0491C004, 0x05BD442E,

  178973.     0x05BE3C04, 0x074000F6, 0x07440027, 0x0744A4B5, 0x07480046,

  178974.     0x074C0057, 0x075B0401, 0x075B6C01, 0x075BEC01, 0x075C5401,

  178975.     0x075CD401, 0x075D3C01, 0x075DBC01, 0x075E2401, 0x075EA401,

  178976.     0x075F0C01, 0x07BBC002, 0x07C0002C, 0x07C0C064, 0x07C2800F,

  178977.     0x07C2C40E, 0x07C3040F, 0x07C3440F, 0x07C4401F, 0x07C4C03C,

  178978.     0x07C5C02B, 0x07C7981D, 0x07C8402B, 0x07C90009, 0x07C94002,

  178979.     0x07CC0021, 0x07CCC006, 0x07CCDC46, 0x07CE0014, 0x07CE8025,

  178980.     0x07CF1805, 0x07CF8011, 0x07D0003F, 0x07D10001, 0x07D108B6,

  178981.     0x07D3E404, 0x07D4003E, 0x07D50004, 0x07D54018, 0x07D7EC46,

  178982.     0x07D9140B, 0x07DA0046, 0x07DC0074, 0x38000401, 0x38008060,

  178983.     0x380400F0,

  178984.   };

  178985.   static const unsigned int aAscii[4] = {

  178986.     0xFFFFFFFF, 0xFC00FFFF, 0xF8000001, 0xF8000001,

  178987.   };

  178988. 

  178989.   if( (unsigned int)c<128 ){

  178990.     return ( (aAscii[c >> 5] & ((unsigned int)1 << (c & 0x001F)))==0 );

  178991.   }else if( (unsigned int)c<(1<<22) ){

  178992.     unsigned int key = (((unsigned int)c)<<10) | 0x000003FF;

  178993.     int iRes = 0;

  178994.     int iHi = sizeof(aEntry)/sizeof(aEntry[0]) - 1;

  178995.     int iLo = 0;

  178996.     while( iHi>=iLo ){

  178997.       int iTest = (iHi + iLo) / 2;

  178998.       if( key >= aEntry[iTest] ){

  178999.         iRes = iTest;

  179000.         iLo = iTest+1;

  179001.       }else{

  179002.         iHi = iTest-1;

  179003.       }

  179004.     }

  179005.     assert( aEntry[0]<key );

  179006.     assert( key>=aEntry[iRes] );

  179007.     return (((unsigned int)c) >= ((aEntry[iRes]>>10) + (aEntry[iRes]&0x3FF)));

  179008.   }

  179009.   return 1;

  179010. }

  179011. 

  179012. 

  179013. /*

  179014. ** If the argument is a codepoint corresponding to a lowercase letter

  179015. ** in the ASCII range with a diacritic added, return the codepoint

  179016. ** of the ASCII letter only. For example, if passed 235 - "LATIN

  179017. ** SMALL LETTER E WITH DIAERESIS" - return 65 ("LATIN SMALL LETTER

  179018. ** E"). The resuls of passing a codepoint that corresponds to an

  179019. ** uppercase letter are undefined.

  179020. */

  179021. static int remove_diacritic(int c, int bComplex){

  179022.   unsigned short aDia[] = {

  179023.         0,  1797,  1848,  1859,  1891,  1928,  1940,  1995, 

  179024.      2024,  2040,  2060,  2110,  2168,  2206,  2264,  2286, 

  179025.      2344,  2383,  2472,  2488,  2516,  2596,  2668,  2732, 

  179026.      2782,  2842,  2894,  2954,  2984,  3000,  3028,  3336, 

  179027.      3456,  3696,  3712,  3728,  3744,  3766,  3832,  3896, 

  179028.      3912,  3928,  3944,  3968,  4008,  4040,  4056,  4106, 

  179029.      4138,  4170,  4202,  4234,  4266,  4296,  4312,  4344, 

  179030.      4408,  4424,  4442,  4472,  4488,  4504,  6148,  6198, 

  179031.      6264,  6280,  6360,  6429,  6505,  6529, 61448, 61468, 

  179032.     61512, 61534, 61592, 61610, 61642, 61672, 61688, 61704, 

  179033.     61726, 61784, 61800, 61816, 61836, 61880, 61896, 61914, 

  179034.     61948, 61998, 62062, 62122, 62154, 62184, 62200, 62218, 

  179035.     62252, 62302, 62364, 62410, 62442, 62478, 62536, 62554, 

  179036.     62584, 62604, 62640, 62648, 62656, 62664, 62730, 62766, 

  179037.     62830, 62890, 62924, 62974, 63032, 63050, 63082, 63118, 

  179038.     63182, 63242, 63274, 63310, 63368, 63390, 

  179039.   };

  179040. #define HIBIT ((unsigned char)0x80)

  179041.   unsigned char aChar[] = {

  179042.     '\0',      'a',       'c',       'e',       'i',       'n',       

  179043.     'o',       'u',       'y',       'y',       'a',       'c',       

  179044.     'd',       'e',       'e',       'g',       'h',       'i',       

  179045.     'j',       'k',       'l',       'n',       'o',       'r',       

  179046.     's',       't',       'u',       'u',       'w',       'y',       

  179047.     'z',       'o',       'u',       'a',       'i',       'o',       

  179048.     'u',       'u'|HIBIT, 'a'|HIBIT, 'g',       'k',       'o',       

  179049.     'o'|HIBIT, 'j',       'g',       'n',       'a'|HIBIT, 'a',       

  179050.     'e',       'i',       'o',       'r',       'u',       's',       

  179051.     't',       'h',       'a',       'e',       'o'|HIBIT, 'o',       

  179052.     'o'|HIBIT, 'y',       '\0',      '\0',      '\0',      '\0',      

  179053.     '\0',      '\0',      '\0',      '\0',      'a',       'b',       

  179054.     'c'|HIBIT, 'd',       'd',       'e'|HIBIT, 'e',       'e'|HIBIT, 

  179055.     'f',       'g',       'h',       'h',       'i',       'i'|HIBIT, 

  179056.     'k',       'l',       'l'|HIBIT, 'l',       'm',       'n',       

  179057.     'o'|HIBIT, 'p',       'r',       'r'|HIBIT, 'r',       's',       

  179058.     's'|HIBIT, 't',       'u',       'u'|HIBIT, 'v',       'w',       

  179059.     'w',       'x',       'y',       'z',       'h',       't',       

  179060.     'w',       'y',       'a',       'a'|HIBIT, 'a'|HIBIT, 'a'|HIBIT, 

  179061.     'e',       'e'|HIBIT, 'e'|HIBIT, 'i',       'o',       'o'|HIBIT, 

  179062.     'o'|HIBIT, 'o'|HIBIT, 'u',       'u'|HIBIT, 'u'|HIBIT, 'y',       

  179063.   };

  179064. 

  179065.   unsigned int key = (((unsigned int)c)<<3) | 0x00000007;

  179066.   int iRes = 0;

  179067.   int iHi = sizeof(aDia)/sizeof(aDia[0]) - 1;

  179068.   int iLo = 0;

  179069.   while( iHi>=iLo ){

  179070.     int iTest = (iHi + iLo) / 2;

  179071.     if( key >= aDia[iTest] ){

  179072.       iRes = iTest;

  179073.       iLo = iTest+1;

  179074.     }else{

  179075.       iHi = iTest-1;

  179076.     }

  179077.   }

  179078.   assert( key>=aDia[iRes] );

  179079.   if( bComplex==0 && (aChar[iRes] & 0x80) ) return c;

  179080.   return (c > (aDia[iRes]>>3) + (aDia[iRes]&0x07)) ? c : ((int)aChar[iRes] & 0x7F);

  179081. }

  179082. 

  179083. 

  179084. /*

  179085. ** Return true if the argument interpreted as a unicode codepoint

  179086. ** is a diacritical modifier character.

  179087. */

  179088. SQLITE_PRIVATE int sqlite3FtsUnicodeIsdiacritic(int c){

  179089.   unsigned int mask0 = 0x08029FDF;

  179090.   unsigned int mask1 = 0x000361F8;

  179091.   if( c<768 || c>817 ) return 0;

  179092.   return (c < 768+32) ?

  179093.       (mask0 & ((unsigned int)1 << (c-768))) :

  179094.       (mask1 & ((unsigned int)1 << (c-768-32)));

  179095. }

  179096. 

  179097. 

  179098. /*

  179099. ** Interpret the argument as a unicode codepoint. If the codepoint

  179100. ** is an upper case character that has a lower case equivalent,

  179101. ** return the codepoint corresponding to the lower case version.

  179102. ** Otherwise, return a copy of the argument.

  179103. **

  179104. ** The results are undefined if the value passed to this function

  179105. ** is less than zero.

  179106. */

  179107. SQLITE_PRIVATE int sqlite3FtsUnicodeFold(int c, int eRemoveDiacritic){

  179108.   /* Each entry in the following array defines a rule for folding a range

  179109.   ** of codepoints to lower case. The rule applies to a range of nRange

  179110.   ** codepoints starting at codepoint iCode.

  179111.   **

  179112.   ** If the least significant bit in flags is clear, then the rule applies

  179113.   ** to all nRange codepoints (i.e. all nRange codepoints are upper case and

  179114.   ** need to be folded). Or, if it is set, then the rule only applies to

  179115.   ** every second codepoint in the range, starting with codepoint C.

  179116.   **

  179117.   ** The 7 most significant bits in flags are an index into the aiOff[]

  179118.   ** array. If a specific codepoint C does require folding, then its lower

  179119.   ** case equivalent is ((C + aiOff[flags>>1]) & 0xFFFF).

  179120.   **

  179121.   ** The contents of this array are generated by parsing the CaseFolding.txt

  179122.   ** file distributed as part of the "Unicode Character Database". See

  179123.   ** http://www.unicode.org for details.

  179124.   */

  179125.   static const struct TableEntry {

  179126.     unsigned short iCode;

  179127.     unsigned char flags;

  179128.     unsigned char nRange;

  179129.   } aEntry[] = {

  179130.     {65, 14, 26},          {181, 64, 1},          {192, 14, 23},

  179131.     {216, 14, 7},          {256, 1, 48},          {306, 1, 6},

  179132.     {313, 1, 16},          {330, 1, 46},          {376, 116, 1},

  179133.     {377, 1, 6},           {383, 104, 1},         {385, 50, 1},

  179134.     {386, 1, 4},           {390, 44, 1},          {391, 0, 1},

  179135.     {393, 42, 2},          {395, 0, 1},           {398, 32, 1},

  179136.     {399, 38, 1},          {400, 40, 1},          {401, 0, 1},

  179137.     {403, 42, 1},          {404, 46, 1},          {406, 52, 1},

  179138.     {407, 48, 1},          {408, 0, 1},           {412, 52, 1},

  179139.     {413, 54, 1},          {415, 56, 1},          {416, 1, 6},

  179140.     {422, 60, 1},          {423, 0, 1},           {425, 60, 1},

  179141.     {428, 0, 1},           {430, 60, 1},          {431, 0, 1},

  179142.     {433, 58, 2},          {435, 1, 4},           {439, 62, 1},

  179143.     {440, 0, 1},           {444, 0, 1},           {452, 2, 1},

  179144.     {453, 0, 1},           {455, 2, 1},           {456, 0, 1},

  179145.     {458, 2, 1},           {459, 1, 18},          {478, 1, 18},

  179146.     {497, 2, 1},           {498, 1, 4},           {502, 122, 1},

  179147.     {503, 134, 1},         {504, 1, 40},          {544, 110, 1},

  179148.     {546, 1, 18},          {570, 70, 1},          {571, 0, 1},

  179149.     {573, 108, 1},         {574, 68, 1},          {577, 0, 1},

  179150.     {579, 106, 1},         {580, 28, 1},          {581, 30, 1},

  179151.     {582, 1, 10},          {837, 36, 1},          {880, 1, 4},

  179152.     {886, 0, 1},           {902, 18, 1},          {904, 16, 3},

  179153.     {908, 26, 1},          {910, 24, 2},          {913, 14, 17},

  179154.     {931, 14, 9},          {962, 0, 1},           {975, 4, 1},

  179155.     {976, 140, 1},         {977, 142, 1},         {981, 146, 1},

  179156.     {982, 144, 1},         {984, 1, 24},          {1008, 136, 1},

  179157.     {1009, 138, 1},        {1012, 130, 1},        {1013, 128, 1},

  179158.     {1015, 0, 1},          {1017, 152, 1},        {1018, 0, 1},

  179159.     {1021, 110, 3},        {1024, 34, 16},        {1040, 14, 32},

  179160.     {1120, 1, 34},         {1162, 1, 54},         {1216, 6, 1},

  179161.     {1217, 1, 14},         {1232, 1, 88},         {1329, 22, 38},

  179162.     {4256, 66, 38},        {4295, 66, 1},         {4301, 66, 1},

  179163.     {7680, 1, 150},        {7835, 132, 1},        {7838, 96, 1},

  179164.     {7840, 1, 96},         {7944, 150, 8},        {7960, 150, 6},

  179165.     {7976, 150, 8},        {7992, 150, 8},        {8008, 150, 6},

  179166.     {8025, 151, 8},        {8040, 150, 8},        {8072, 150, 8},

  179167.     {8088, 150, 8},        {8104, 150, 8},        {8120, 150, 2},

  179168.     {8122, 126, 2},        {8124, 148, 1},        {8126, 100, 1},

  179169.     {8136, 124, 4},        {8140, 148, 1},        {8152, 150, 2},

  179170.     {8154, 120, 2},        {8168, 150, 2},        {8170, 118, 2},

  179171.     {8172, 152, 1},        {8184, 112, 2},        {8186, 114, 2},

  179172.     {8188, 148, 1},        {8486, 98, 1},         {8490, 92, 1},

  179173.     {8491, 94, 1},         {8498, 12, 1},         {8544, 8, 16},

  179174.     {8579, 0, 1},          {9398, 10, 26},        {11264, 22, 47},

  179175.     {11360, 0, 1},         {11362, 88, 1},        {11363, 102, 1},

  179176.     {11364, 90, 1},        {11367, 1, 6},         {11373, 84, 1},

  179177.     {11374, 86, 1},        {11375, 80, 1},        {11376, 82, 1},

  179178.     {11378, 0, 1},         {11381, 0, 1},         {11390, 78, 2},

  179179.     {11392, 1, 100},       {11499, 1, 4},         {11506, 0, 1},

  179180.     {42560, 1, 46},        {42624, 1, 24},        {42786, 1, 14},

  179181.     {42802, 1, 62},        {42873, 1, 4},         {42877, 76, 1},

  179182.     {42878, 1, 10},        {42891, 0, 1},         {42893, 74, 1},

  179183.     {42896, 1, 4},         {42912, 1, 10},        {42922, 72, 1},

  179184.     {65313, 14, 26},       

  179185.   };

  179186.   static const unsigned short aiOff[] = {

  179187.    1,     2,     8,     15,    16,    26,    28,    32,    

  179188.    37,    38,    40,    48,    63,    64,    69,    71,    

  179189.    79,    80,    116,   202,   203,   205,   206,   207,   

  179190.    209,   210,   211,   213,   214,   217,   218,   219,   

  179191.    775,   7264,  10792, 10795, 23228, 23256, 30204, 54721, 

  179192.    54753, 54754, 54756, 54787, 54793, 54809, 57153, 57274, 

  179193.    57921, 58019, 58363, 61722, 65268, 65341, 65373, 65406, 

  179194.    65408, 65410, 65415, 65424, 65436, 65439, 65450, 65462, 

  179195.    65472, 65476, 65478, 65480, 65482, 65488, 65506, 65511, 

  179196.    65514, 65521, 65527, 65528, 65529, 

  179197.   };

  179198. 

  179199.   int ret = c;

  179200. 

  179201.   assert( sizeof(unsigned short)==2 && sizeof(unsigned char)==1 );

  179202. 

  179203.   if( c<128 ){

  179204.     if( c>='A' && c<='Z' ) ret = c + ('a' - 'A');

  179205.   }else if( c<65536 ){

  179206.     const struct TableEntry *p;

  179207.     int iHi = sizeof(aEntry)/sizeof(aEntry[0]) - 1;

  179208.     int iLo = 0;

  179209.     int iRes = -1;

  179210. 

  179211.     assert( c>aEntry[0].iCode );

  179212.     while( iHi>=iLo ){

  179213.       int iTest = (iHi + iLo) / 2;

  179214.       int cmp = (c - aEntry[iTest].iCode);

  179215.       if( cmp>=0 ){

  179216.         iRes = iTest;

  179217.         iLo = iTest+1;

  179218.       }else{

  179219.         iHi = iTest-1;

  179220.       }

  179221.     }

  179222. 

  179223.     assert( iRes>=0 && c>=aEntry[iRes].iCode );

  179224.     p = &aEntry[iRes];

  179225.     if( c<(p->iCode + p->nRange) && 0==(0x01 & p->flags & (p->iCode ^ c)) ){

  179226.       ret = (c + (aiOff[p->flags>>1])) & 0x0000FFFF;

  179227.       assert( ret>0 );

  179228.     }

  179229. 

  179230.     if( eRemoveDiacritic ){

  179231.       ret = remove_diacritic(ret, eRemoveDiacritic==2);

  179232.     }

  179233.   }

  179234.   

  179235.   else if( c>=66560 && c<66600 ){

  179236.     ret = c + 40;

  179237.   }

  179238. 

  179239.   return ret;

  179240. }

  179241. #endif /* defined(SQLITE_ENABLE_FTS3) || defined(SQLITE_ENABLE_FTS4) */

  179242. #endif /* !defined(SQLITE_DISABLE_FTS3_UNICODE) */

  179243. 

  179244. /************** End of fts3_unicode2.c ***************************************/

  179245. /************** Begin file json1.c *******************************************/

  179246. /*

  179247. ** 2015-08-12

  179248. **

  179249. ** The author disclaims copyright to this source code.  In place of

  179250. ** a legal notice, here is a blessing:

  179251. **

  179252. **    May you do good and not evil.

  179253. **    May you find forgiveness for yourself and forgive others.

  179254. **    May you share freely, never taking more than you give.

  179255. **

  179256. ******************************************************************************

  179257. **

  179258. ** This SQLite extension implements JSON functions.  The interface is

  179259. ** modeled after MySQL JSON functions:

  179260. **

  179261. **     https://dev.mysql.com/doc/refman/5.7/en/json.html

  179262. **

  179263. ** For the time being, all JSON is stored as pure text.  (We might add

  179264. ** a JSONB type in the future which stores a binary encoding of JSON in

  179265. ** a BLOB, but there is no support for JSONB in the current implementation.

  179266. ** This implementation parses JSON text at 250 MB/s, so it is hard to see

  179267. ** how JSONB might improve on that.)

  179268. */

  179269. #if !defined(SQLITE_CORE) || defined(SQLITE_ENABLE_JSON1)

  179270. #if !defined(SQLITEINT_H)

  179271. /* #include "sqlite3ext.h" */

  179272. #endif

  179273. SQLITE_EXTENSION_INIT1

  179274. /* #include <assert.h> */

  179275. /* #include <string.h> */

  179276. /* #include <stdlib.h> */

  179277. /* #include <stdarg.h> */

  179278. 

  179279. /* Mark a function parameter as unused, to suppress nuisance compiler

  179280. ** warnings. */

  179281. #ifndef UNUSED_PARAM

  179282. # define UNUSED_PARAM(X)  (void)(X)

  179283. #endif

  179284. 

  179285. #ifndef LARGEST_INT64

  179286. # define LARGEST_INT64  (0xffffffff|(((sqlite3_int64)0x7fffffff)<<32))

  179287. # define SMALLEST_INT64 (((sqlite3_int64)-1) - LARGEST_INT64)

  179288. #endif

  179289. 

  179290. /*

  179291. ** Versions of isspace(), isalnum() and isdigit() to which it is safe

  179292. ** to pass signed char values.

  179293. */

  179294. #ifdef sqlite3Isdigit

  179295.    /* Use the SQLite core versions if this routine is part of the

  179296.    ** SQLite amalgamation */

  179297. #  define safe_isdigit(x)  sqlite3Isdigit(x)

  179298. #  define safe_isalnum(x)  sqlite3Isalnum(x)

  179299. #  define safe_isxdigit(x) sqlite3Isxdigit(x)

  179300. #else

  179301.    /* Use the standard library for separate compilation */

  179302. #include <ctype.h>  /* amalgamator: keep */

  179303. #  define safe_isdigit(x)  isdigit((unsigned char)(x))

  179304. #  define safe_isalnum(x)  isalnum((unsigned char)(x))

  179305. #  define safe_isxdigit(x) isxdigit((unsigned char)(x))

  179306. #endif

  179307. 

  179308. /*

  179309. ** Growing our own isspace() routine this way is twice as fast as

  179310. ** the library isspace() function, resulting in a 7% overall performance

  179311. ** increase for the parser.  (Ubuntu14.10 gcc 4.8.4 x64 with -Os).

  179312. */

  179313. static const char jsonIsSpace[] = {

  179314.   0, 0, 0, 0, 0, 0, 0, 0,     0, 1, 1, 0, 0, 1, 0, 0,

  179315.   0, 0, 0, 0, 0, 0, 0, 0,     0, 0, 0, 0, 0, 0, 0, 0,

  179316.   1, 0, 0, 0, 0, 0, 0, 0,     0, 0, 0, 0, 0, 0, 0, 0,

  179317.   0, 0, 0, 0, 0, 0, 0, 0,     0, 0, 0, 0, 0, 0, 0, 0,

  179318.   0, 0, 0, 0, 0, 0, 0, 0,     0, 0, 0, 0, 0, 0, 0, 0,

  179319.   0, 0, 0, 0, 0, 0, 0, 0,     0, 0, 0, 0, 0, 0, 0, 0,

  179320.   0, 0, 0, 0, 0, 0, 0, 0,     0, 0, 0, 0, 0, 0, 0, 0,

  179321.   0, 0, 0, 0, 0, 0, 0, 0,     0, 0, 0, 0, 0, 0, 0, 0,

  179322.   0, 0, 0, 0, 0, 0, 0, 0,     0, 0, 0, 0, 0, 0, 0, 0,

  179323.   0, 0, 0, 0, 0, 0, 0, 0,     0, 0, 0, 0, 0, 0, 0, 0,

  179324.   0, 0, 0, 0, 0, 0, 0, 0,     0, 0, 0, 0, 0, 0, 0, 0,

  179325.   0, 0, 0, 0, 0, 0, 0, 0,     0, 0, 0, 0, 0, 0, 0, 0,

  179326.   0, 0, 0, 0, 0, 0, 0, 0,     0, 0, 0, 0, 0, 0, 0, 0,

  179327.   0, 0, 0, 0, 0, 0, 0, 0,     0, 0, 0, 0, 0, 0, 0, 0,

  179328.   0, 0, 0, 0, 0, 0, 0, 0,     0, 0, 0, 0, 0, 0, 0, 0,

  179329.   0, 0, 0, 0, 0, 0, 0, 0,     0, 0, 0, 0, 0, 0, 0, 0,

  179330. };

  179331. #define safe_isspace(x) (jsonIsSpace[(unsigned char)x])

  179332. 

  179333. #ifndef SQLITE_AMALGAMATION

  179334.   /* Unsigned integer types.  These are already defined in the sqliteInt.h,

  179335.   ** but the definitions need to be repeated for separate compilation. */

  179336.   typedef sqlite3_uint64 u64;

  179337.   typedef unsigned int u32;

  179338.   typedef unsigned short int u16;

  179339.   typedef unsigned char u8;

  179340. #endif

  179341. 

  179342. /* Objects */

  179343. typedef struct JsonString JsonString;

  179344. typedef struct JsonNode JsonNode;

  179345. typedef struct JsonParse JsonParse;

  179346. 

  179347. /* An instance of this object represents a JSON string

  179348. ** under construction.  Really, this is a generic string accumulator

  179349. ** that can be and is used to create strings other than JSON.

  179350. */

  179351. struct JsonString {

  179352.   sqlite3_context *pCtx;   /* Function context - put error messages here */

  179353.   char *zBuf;              /* Append JSON content here */

  179354.   u64 nAlloc;              /* Bytes of storage available in zBuf[] */

  179355.   u64 nUsed;               /* Bytes of zBuf[] currently used */

  179356.   u8 bStatic;              /* True if zBuf is static space */

  179357.   u8 bErr;                 /* True if an error has been encountered */

  179358.   char zSpace[100];        /* Initial static space */

  179359. };

  179360. 

  179361. /* JSON type values

  179362. */

  179363. #define JSON_NULL     0

  179364. #define JSON_TRUE     1

  179365. #define JSON_FALSE    2

  179366. #define JSON_INT      3

  179367. #define JSON_REAL     4

  179368. #define JSON_STRING   5

  179369. #define JSON_ARRAY    6

  179370. #define JSON_OBJECT   7

  179371. 

  179372. /* The "subtype" set for JSON values */

  179373. #define JSON_SUBTYPE  74    /* Ascii for "J" */

  179374. 

  179375. /*

  179376. ** Names of the various JSON types:

  179377. */

  179378. static const char * const jsonType[] = {

  179379.   "null", "true", "false", "integer", "real", "text", "array", "object"

  179380. };

  179381. 

  179382. /* Bit values for the JsonNode.jnFlag field

  179383. */

  179384. #define JNODE_RAW     0x01         /* Content is raw, not JSON encoded */

  179385. #define JNODE_ESCAPE  0x02         /* Content is text with \ escapes */

  179386. #define JNODE_REMOVE  0x04         /* Do not output */

  179387. #define JNODE_REPLACE 0x08         /* Replace with JsonNode.u.iReplace */

  179388. #define JNODE_PATCH   0x10         /* Patch with JsonNode.u.pPatch */

  179389. #define JNODE_APPEND  0x20         /* More ARRAY/OBJECT entries at u.iAppend */

  179390. #define JNODE_LABEL   0x40         /* Is a label of an object */

  179391. 

  179392. 

  179393. /* A single node of parsed JSON

  179394. */

  179395. struct JsonNode {

  179396.   u8 eType;              /* One of the JSON_ type values */

  179397.   u8 jnFlags;            /* JNODE flags */

  179398.   u32 n;                 /* Bytes of content, or number of sub-nodes */

  179399.   union {

  179400.     const char *zJContent; /* Content for INT, REAL, and STRING */

  179401.     u32 iAppend;           /* More terms for ARRAY and OBJECT */

  179402.     u32 iKey;              /* Key for ARRAY objects in json_tree() */

  179403.     u32 iReplace;          /* Replacement content for JNODE_REPLACE */

  179404.     JsonNode *pPatch;      /* Node chain of patch for JNODE_PATCH */

  179405.   } u;

  179406. };

  179407. 

  179408. /* A completely parsed JSON string

  179409. */

  179410. struct JsonParse {

  179411.   u32 nNode;         /* Number of slots of aNode[] used */

  179412.   u32 nAlloc;        /* Number of slots of aNode[] allocated */

  179413.   JsonNode *aNode;   /* Array of nodes containing the parse */

  179414.   const char *zJson; /* Original JSON string */

  179415.   u32 *aUp;          /* Index of parent of each node */

  179416.   u8 oom;            /* Set to true if out of memory */

  179417.   u8 nErr;           /* Number of errors seen */

  179418.   u16 iDepth;        /* Nesting depth */

  179419.   int nJson;         /* Length of the zJson string in bytes */

  179420.   u32 iHold;         /* Replace cache line with the lowest iHold value */

  179421. };

  179422. 

  179423. /*

  179424. ** Maximum nesting depth of JSON for this implementation.

  179425. **

  179426. ** This limit is needed to avoid a stack overflow in the recursive

  179427. ** descent parser.  A depth of 2000 is far deeper than any sane JSON

  179428. ** should go.

  179429. */

  179430. #define JSON_MAX_DEPTH  2000

  179431. 

  179432. /**************************************************************************

  179433. ** Utility routines for dealing with JsonString objects

  179434. **************************************************************************/

  179435. 

  179436. /* Set the JsonString object to an empty string

  179437. */

  179438. static void jsonZero(JsonString *p){

  179439.   p->zBuf = p->zSpace;

  179440.   p->nAlloc = sizeof(p->zSpace);

  179441.   p->nUsed = 0;

  179442.   p->bStatic = 1;

  179443. }

  179444. 

  179445. /* Initialize the JsonString object

  179446. */

  179447. static void jsonInit(JsonString *p, sqlite3_context *pCtx){

  179448.   p->pCtx = pCtx;

  179449.   p->bErr = 0;

  179450.   jsonZero(p);

  179451. }

  179452. 

  179453. 

  179454. /* Free all allocated memory and reset the JsonString object back to its

  179455. ** initial state.

  179456. */

  179457. static void jsonReset(JsonString *p){

  179458.   if( !p->bStatic ) sqlite3_free(p->zBuf);

  179459.   jsonZero(p);

  179460. }

  179461. 

  179462. 

  179463. /* Report an out-of-memory (OOM) condition 

  179464. */

  179465. static void jsonOom(JsonString *p){

  179466.   p->bErr = 1;

  179467.   sqlite3_result_error_nomem(p->pCtx);

  179468.   jsonReset(p);

  179469. }

  179470. 

  179471. /* Enlarge pJson->zBuf so that it can hold at least N more bytes.

  179472. ** Return zero on success.  Return non-zero on an OOM error

  179473. */

  179474. static int jsonGrow(JsonString *p, u32 N){

  179475.   u64 nTotal = N<p->nAlloc ? p->nAlloc*2 : p->nAlloc+N+10;

  179476.   char *zNew;

  179477.   if( p->bStatic ){

  179478.     if( p->bErr ) return 1;

  179479.     zNew = sqlite3_malloc64(nTotal);

  179480.     if( zNew==0 ){

  179481.       jsonOom(p);

  179482.       return SQLITE_NOMEM;

  179483.     }

  179484.     memcpy(zNew, p->zBuf, (size_t)p->nUsed);

  179485.     p->zBuf = zNew;

  179486.     p->bStatic = 0;

  179487.   }else{

  179488.     zNew = sqlite3_realloc64(p->zBuf, nTotal);

  179489.     if( zNew==0 ){

  179490.       jsonOom(p);

  179491.       return SQLITE_NOMEM;

  179492.     }

  179493.     p->zBuf = zNew;

  179494.   }

  179495.   p->nAlloc = nTotal;

  179496.   return SQLITE_OK;

  179497. }

  179498. 

  179499. /* Append N bytes from zIn onto the end of the JsonString string.

  179500. */

  179501. static void jsonAppendRaw(JsonString *p, const char *zIn, u32 N){

  179502.   if( (N+p->nUsed >= p->nAlloc) && jsonGrow(p,N)!=0 ) return;

  179503.   memcpy(p->zBuf+p->nUsed, zIn, N);

  179504.   p->nUsed += N;

  179505. }

  179506. 

  179507. /* Append formatted text (not to exceed N bytes) to the JsonString.

  179508. */

  179509. static void jsonPrintf(int N, JsonString *p, const char *zFormat, ...){

  179510.   va_list ap;

  179511.   if( (p->nUsed + N >= p->nAlloc) && jsonGrow(p, N) ) return;

  179512.   va_start(ap, zFormat);

  179513.   sqlite3_vsnprintf(N, p->zBuf+p->nUsed, zFormat, ap);

  179514.   va_end(ap);

  179515.   p->nUsed += (int)strlen(p->zBuf+p->nUsed);

  179516. }

  179517. 

  179518. /* Append a single character

  179519. */

  179520. static void jsonAppendChar(JsonString *p, char c){

  179521.   if( p->nUsed>=p->nAlloc && jsonGrow(p,1)!=0 ) return;

  179522.   p->zBuf[p->nUsed++] = c;

  179523. }

  179524. 

  179525. /* Append a comma separator to the output buffer, if the previous

  179526. ** character is not '[' or '{'.

  179527. */

  179528. static void jsonAppendSeparator(JsonString *p){

  179529.   char c;

  179530.   if( p->nUsed==0 ) return;

  179531.   c = p->zBuf[p->nUsed-1];

  179532.   if( c!='[' && c!='{' ) jsonAppendChar(p, ',');

  179533. }

  179534. 

  179535. /* Append the N-byte string in zIn to the end of the JsonString string

  179536. ** under construction.  Enclose the string in "..." and escape

  179537. ** any double-quotes or backslash characters contained within the

  179538. ** string.

  179539. */

  179540. static void jsonAppendString(JsonString *p, const char *zIn, u32 N){

  179541.   u32 i;

  179542.   if( (N+p->nUsed+2 >= p->nAlloc) && jsonGrow(p,N+2)!=0 ) return;

  179543.   p->zBuf[p->nUsed++] = '"';

  179544.   for(i=0; i<N; i++){

  179545.     unsigned char c = ((unsigned const char*)zIn)[i];

  179546.     if( c=='"' || c=='\\' ){

  179547.       json_simple_escape:

  179548.       if( (p->nUsed+N+3-i > p->nAlloc) && jsonGrow(p,N+3-i)!=0 ) return;

  179549.       p->zBuf[p->nUsed++] = '\\';

  179550.     }else if( c<=0x1f ){

  179551.       static const char aSpecial[] = {

  179552.          0, 0, 0, 0, 0, 0, 0, 0, 'b', 't', 'n', 0, 'f', 'r', 0, 0,

  179553.          0, 0, 0, 0, 0, 0, 0, 0,   0,   0,   0, 0,   0,   0, 0, 0

  179554.       };

  179555.       assert( sizeof(aSpecial)==32 );

  179556.       assert( aSpecial['\b']=='b' );

  179557.       assert( aSpecial['\f']=='f' );

  179558.       assert( aSpecial['\n']=='n' );

  179559.       assert( aSpecial['\r']=='r' );

  179560.       assert( aSpecial['\t']=='t' );

  179561.       if( aSpecial[c] ){

  179562.         c = aSpecial[c];

  179563.         goto json_simple_escape;

  179564.       }

  179565.       if( (p->nUsed+N+7+i > p->nAlloc) && jsonGrow(p,N+7-i)!=0 ) return;

  179566.       p->zBuf[p->nUsed++] = '\\';

  179567.       p->zBuf[p->nUsed++] = 'u';

  179568.       p->zBuf[p->nUsed++] = '0';

  179569.       p->zBuf[p->nUsed++] = '0';

  179570.       p->zBuf[p->nUsed++] = '0' + (c>>4);

  179571.       c = "0123456789abcdef"[c&0xf];

  179572.     }

  179573.     p->zBuf[p->nUsed++] = c;

  179574.   }

  179575.   p->zBuf[p->nUsed++] = '"';

  179576.   assert( p->nUsed<p->nAlloc );

  179577. }

  179578. 

  179579. /*

  179580. ** Append a function parameter value to the JSON string under 

  179581. ** construction.

  179582. */

  179583. static void jsonAppendValue(

  179584.   JsonString *p,                 /* Append to this JSON string */

  179585.   sqlite3_value *pValue          /* Value to append */

  179586. ){

  179587.   switch( sqlite3_value_type(pValue) ){

  179588.     case SQLITE_NULL: {

  179589.       jsonAppendRaw(p, "null", 4);

  179590.       break;

  179591.     }

  179592.     case SQLITE_INTEGER:

  179593.     case SQLITE_FLOAT: {

  179594.       const char *z = (const char*)sqlite3_value_text(pValue);

  179595.       u32 n = (u32)sqlite3_value_bytes(pValue);

  179596.       jsonAppendRaw(p, z, n);

  179597.       break;

  179598.     }

  179599.     case SQLITE_TEXT: {

  179600.       const char *z = (const char*)sqlite3_value_text(pValue);

  179601.       u32 n = (u32)sqlite3_value_bytes(pValue);

  179602.       if( sqlite3_value_subtype(pValue)==JSON_SUBTYPE ){

  179603.         jsonAppendRaw(p, z, n);

  179604.       }else{

  179605.         jsonAppendString(p, z, n);

  179606.       }

  179607.       break;

  179608.     }

  179609.     default: {

  179610.       if( p->bErr==0 ){

  179611.         sqlite3_result_error(p->pCtx, "JSON cannot hold BLOB values", -1);

  179612.         p->bErr = 2;

  179613.         jsonReset(p);

  179614.       }

  179615.       break;

  179616.     }

  179617.   }

  179618. }

  179619. 

  179620. 

  179621. /* Make the JSON in p the result of the SQL function.

  179622. */

  179623. static void jsonResult(JsonString *p){

  179624.   if( p->bErr==0 ){

  179625.     sqlite3_result_text64(p->pCtx, p->zBuf, p->nUsed, 

  179626.                           p->bStatic ? SQLITE_TRANSIENT : sqlite3_free,

  179627.                           SQLITE_UTF8);

  179628.     jsonZero(p);

  179629.   }

  179630.   assert( p->bStatic );

  179631. }

  179632. 

  179633. /**************************************************************************

  179634. ** Utility routines for dealing with JsonNode and JsonParse objects

  179635. **************************************************************************/

  179636. 

  179637. /*

  179638. ** Return the number of consecutive JsonNode slots need to represent

  179639. ** the parsed JSON at pNode.  The minimum answer is 1.  For ARRAY and

  179640. ** OBJECT types, the number might be larger.

  179641. **

  179642. ** Appended elements are not counted.  The value returned is the number

  179643. ** by which the JsonNode counter should increment in order to go to the

  179644. ** next peer value.

  179645. */

  179646. static u32 jsonNodeSize(JsonNode *pNode){

  179647.   return pNode->eType>=JSON_ARRAY ? pNode->n+1 : 1;

  179648. }

  179649. 

  179650. /*

  179651. ** Reclaim all memory allocated by a JsonParse object.  But do not

  179652. ** delete the JsonParse object itself.

  179653. */

  179654. static void jsonParseReset(JsonParse *pParse){

  179655.   sqlite3_free(pParse->aNode);

  179656.   pParse->aNode = 0;

  179657.   pParse->nNode = 0;

  179658.   pParse->nAlloc = 0;

  179659.   sqlite3_free(pParse->aUp);

  179660.   pParse->aUp = 0;

  179661. }

  179662. 

  179663. /*

  179664. ** Free a JsonParse object that was obtained from sqlite3_malloc().

  179665. */

  179666. static void jsonParseFree(JsonParse *pParse){

  179667.   jsonParseReset(pParse);

  179668.   sqlite3_free(pParse);

  179669. }

  179670. 

  179671. /*

  179672. ** Convert the JsonNode pNode into a pure JSON string and

  179673. ** append to pOut.  Subsubstructure is also included.  Return

  179674. ** the number of JsonNode objects that are encoded.

  179675. */

  179676. static void jsonRenderNode(

  179677.   JsonNode *pNode,               /* The node to render */

  179678.   JsonString *pOut,              /* Write JSON here */

  179679.   sqlite3_value **aReplace       /* Replacement values */

  179680. ){

  179681.   if( pNode->jnFlags & (JNODE_REPLACE|JNODE_PATCH) ){

  179682.     if( pNode->jnFlags & JNODE_REPLACE ){

  179683.       jsonAppendValue(pOut, aReplace[pNode->u.iReplace]);

  179684.       return;

  179685.     }

  179686.     pNode = pNode->u.pPatch;

  179687.   }

  179688.   switch( pNode->eType ){

  179689.     default: {

  179690.       assert( pNode->eType==JSON_NULL );

  179691.       jsonAppendRaw(pOut, "null", 4);

  179692.       break;

  179693.     }

  179694.     case JSON_TRUE: {

  179695.       jsonAppendRaw(pOut, "true", 4);

  179696.       break;

  179697.     }

  179698.     case JSON_FALSE: {

  179699.       jsonAppendRaw(pOut, "false", 5);

  179700.       break;

  179701.     }

  179702.     case JSON_STRING: {

  179703.       if( pNode->jnFlags & JNODE_RAW ){

  179704.         jsonAppendString(pOut, pNode->u.zJContent, pNode->n);

  179705.         break;

  179706.       }

  179707.       /* Fall through into the next case */

  179708.     }

  179709.     case JSON_REAL:

  179710.     case JSON_INT: {

  179711.       jsonAppendRaw(pOut, pNode->u.zJContent, pNode->n);

  179712.       break;

  179713.     }

  179714.     case JSON_ARRAY: {

  179715.       u32 j = 1;

  179716.       jsonAppendChar(pOut, '[');

  179717.       for(;;){

  179718.         while( j<=pNode->n ){

  179719.           if( (pNode[j].jnFlags & JNODE_REMOVE)==0 ){

  179720.             jsonAppendSeparator(pOut);

  179721.             jsonRenderNode(&pNode[j], pOut, aReplace);

  179722.           }

  179723.           j += jsonNodeSize(&pNode[j]);

  179724.         }

  179725.         if( (pNode->jnFlags & JNODE_APPEND)==0 ) break;

  179726.         pNode = &pNode[pNode->u.iAppend];

  179727.         j = 1;

  179728.       }

  179729.       jsonAppendChar(pOut, ']');

  179730.       break;

  179731.     }

  179732.     case JSON_OBJECT: {

  179733.       u32 j = 1;

  179734.       jsonAppendChar(pOut, '{');

  179735.       for(;;){

  179736.         while( j<=pNode->n ){

  179737.           if( (pNode[j+1].jnFlags & JNODE_REMOVE)==0 ){

  179738.             jsonAppendSeparator(pOut);

  179739.             jsonRenderNode(&pNode[j], pOut, aReplace);

  179740.             jsonAppendChar(pOut, ':');

  179741.             jsonRenderNode(&pNode[j+1], pOut, aReplace);

  179742.           }

  179743.           j += 1 + jsonNodeSize(&pNode[j+1]);

  179744.         }

  179745.         if( (pNode->jnFlags & JNODE_APPEND)==0 ) break;

  179746.         pNode = &pNode[pNode->u.iAppend];

  179747.         j = 1;

  179748.       }

  179749.       jsonAppendChar(pOut, '}');

  179750.       break;

  179751.     }

  179752.   }

  179753. }

  179754. 

  179755. /*

  179756. ** Return a JsonNode and all its descendents as a JSON string.

  179757. */

  179758. static void jsonReturnJson(

  179759.   JsonNode *pNode,            /* Node to return */

  179760.   sqlite3_context *pCtx,      /* Return value for this function */

  179761.   sqlite3_value **aReplace    /* Array of replacement values */

  179762. ){

  179763.   JsonString s;

  179764.   jsonInit(&s, pCtx);

  179765.   jsonRenderNode(pNode, &s, aReplace);

  179766.   jsonResult(&s);

  179767.   sqlite3_result_subtype(pCtx, JSON_SUBTYPE);

  179768. }

  179769. 

  179770. /*

  179771. ** Make the JsonNode the return value of the function.

  179772. */

  179773. static void jsonReturn(

  179774.   JsonNode *pNode,            /* Node to return */

  179775.   sqlite3_context *pCtx,      /* Return value for this function */

  179776.   sqlite3_value **aReplace    /* Array of replacement values */

  179777. ){

  179778.   switch( pNode->eType ){

  179779.     default: {

  179780.       assert( pNode->eType==JSON_NULL );

  179781.       sqlite3_result_null(pCtx);

  179782.       break;

  179783.     }

  179784.     case JSON_TRUE: {

  179785.       sqlite3_result_int(pCtx, 1);

  179786.       break;

  179787.     }

  179788.     case JSON_FALSE: {

  179789.       sqlite3_result_int(pCtx, 0);

  179790.       break;

  179791.     }

  179792.     case JSON_INT: {

  179793.       sqlite3_int64 i = 0;

  179794.       const char *z = pNode->u.zJContent;

  179795.       if( z[0]=='-' ){ z++; }

  179796.       while( z[0]>='0' && z[0]<='9' ){

  179797.         unsigned v = *(z++) - '0';

  179798.         if( i>=LARGEST_INT64/10 ){

  179799.           if( i>LARGEST_INT64/10 ) goto int_as_real;

  179800.           if( z[0]>='0' && z[0]<='9' ) goto int_as_real;

  179801.           if( v==9 ) goto int_as_real;

  179802.           if( v==8 ){

  179803.             if( pNode->u.zJContent[0]=='-' ){

  179804.               sqlite3_result_int64(pCtx, SMALLEST_INT64);

  179805.               goto int_done;

  179806.             }else{

  179807.               goto int_as_real;

  179808.             }

  179809.           }

  179810.         }

  179811.         i = i*10 + v;

  179812.       }

  179813.       if( pNode->u.zJContent[0]=='-' ){ i = -i; }

  179814.       sqlite3_result_int64(pCtx, i);

  179815.       int_done:

  179816.       break;

  179817.       int_as_real: /* fall through to real */;

  179818.     }

  179819.     case JSON_REAL: {

  179820.       double r;

  179821. #ifdef SQLITE_AMALGAMATION

  179822.       const char *z = pNode->u.zJContent;

  179823.       sqlite3AtoF(z, &r, sqlite3Strlen30(z), SQLITE_UTF8);

  179824. #else

  179825.       r = strtod(pNode->u.zJContent, 0);

  179826. #endif

  179827.       sqlite3_result_double(pCtx, r);

  179828.       break;

  179829.     }

  179830.     case JSON_STRING: {

  179831. #if 0 /* Never happens because JNODE_RAW is only set by json_set(),

  179832.       ** json_insert() and json_replace() and those routines do not

  179833.       ** call jsonReturn() */

  179834.       if( pNode->jnFlags & JNODE_RAW ){

  179835.         sqlite3_result_text(pCtx, pNode->u.zJContent, pNode->n,

  179836.                             SQLITE_TRANSIENT);

  179837.       }else 

  179838. #endif

  179839.       assert( (pNode->jnFlags & JNODE_RAW)==0 );

  179840.       if( (pNode->jnFlags & JNODE_ESCAPE)==0 ){

  179841.         /* JSON formatted without any backslash-escapes */

  179842.         sqlite3_result_text(pCtx, pNode->u.zJContent+1, pNode->n-2,

  179843.                             SQLITE_TRANSIENT);

  179844.       }else{

  179845.         /* Translate JSON formatted string into raw text */

  179846.         u32 i;

  179847.         u32 n = pNode->n;

  179848.         const char *z = pNode->u.zJContent;

  179849.         char *zOut;

  179850.         u32 j;

  179851.         zOut = sqlite3_malloc( n+1 );

  179852.         if( zOut==0 ){

  179853.           sqlite3_result_error_nomem(pCtx);

  179854.           break;

  179855.         }

  179856.         for(i=1, j=0; i<n-1; i++){

  179857.           char c = z[i];

  179858.           if( c!='\\' ){

  179859.             zOut[j++] = c;

  179860.           }else{

  179861.             c = z[++i];

  179862.             if( c=='u' ){

  179863.               u32 v = 0, k;

  179864.               for(k=0; k<4; i++, k++){

  179865.                 assert( i<n-2 );

  179866.                 c = z[i+1];

  179867.                 assert( safe_isxdigit(c) );

  179868.                 if( c<='9' ) v = v*16 + c - '0';

  179869.                 else if( c<='F' ) v = v*16 + c - 'A' + 10;

  179870.                 else v = v*16 + c - 'a' + 10;

  179871.               }

  179872.               if( v==0 ) break;

  179873.               if( v<=0x7f ){

  179874.                 zOut[j++] = (char)v;

  179875.               }else if( v<=0x7ff ){

  179876.                 zOut[j++] = (char)(0xc0 | (v>>6));

  179877.                 zOut[j++] = 0x80 | (v&0x3f);

  179878.               }else{

  179879.                 zOut[j++] = (char)(0xe0 | (v>>12));

  179880.                 zOut[j++] = 0x80 | ((v>>6)&0x3f);

  179881.                 zOut[j++] = 0x80 | (v&0x3f);

  179882.               }

  179883.             }else{

  179884.               if( c=='b' ){

  179885.                 c = '\b';

  179886.               }else if( c=='f' ){

  179887.                 c = '\f';

  179888.               }else if( c=='n' ){

  179889.                 c = '\n';

  179890.               }else if( c=='r' ){

  179891.                 c = '\r';

  179892.               }else if( c=='t' ){

  179893.                 c = '\t';

  179894.               }

  179895.               zOut[j++] = c;

  179896.             }

  179897.           }

  179898.         }

  179899.         zOut[j] = 0;

  179900.         sqlite3_result_text(pCtx, zOut, j, sqlite3_free);

  179901.       }

  179902.       break;

  179903.     }

  179904.     case JSON_ARRAY:

  179905.     case JSON_OBJECT: {

  179906.       jsonReturnJson(pNode, pCtx, aReplace);

  179907.       break;

  179908.     }

  179909.   }

  179910. }

  179911. 

  179912. /* Forward reference */

  179913. static int jsonParseAddNode(JsonParse*,u32,u32,const char*);

  179914. 

  179915. /*

  179916. ** A macro to hint to the compiler that a function should not be

  179917. ** inlined.

  179918. */

  179919. #if defined(__GNUC__)

  179920. #  define JSON_NOINLINE  __attribute__((noinline))

  179921. #elif defined(_MSC_VER) && _MSC_VER>=1310

  179922. #  define JSON_NOINLINE  __declspec(noinline)

  179923. #else

  179924. #  define JSON_NOINLINE

  179925. #endif

  179926. 

  179927. 

  179928. static JSON_NOINLINE int jsonParseAddNodeExpand(

  179929.   JsonParse *pParse,        /* Append the node to this object */

  179930.   u32 eType,                /* Node type */

  179931.   u32 n,                    /* Content size or sub-node count */

  179932.   const char *zContent      /* Content */

  179933. ){

  179934.   u32 nNew;

  179935.   JsonNode *pNew;

  179936.   assert( pParse->nNode>=pParse->nAlloc );

  179937.   if( pParse->oom ) return -1;

  179938.   nNew = pParse->nAlloc*2 + 10;

  179939.   pNew = sqlite3_realloc64(pParse->aNode, sizeof(JsonNode)*nNew);

  179940.   if( pNew==0 ){

  179941.     pParse->oom = 1;

  179942.     return -1;

  179943.   }

  179944.   pParse->nAlloc = nNew;

  179945.   pParse->aNode = pNew;

  179946.   assert( pParse->nNode<pParse->nAlloc );

  179947.   return jsonParseAddNode(pParse, eType, n, zContent);

  179948. }

  179949. 

  179950. /*

  179951. ** Create a new JsonNode instance based on the arguments and append that

  179952. ** instance to the JsonParse.  Return the index in pParse->aNode[] of the

  179953. ** new node, or -1 if a memory allocation fails.

  179954. */

  179955. static int jsonParseAddNode(

  179956.   JsonParse *pParse,        /* Append the node to this object */

  179957.   u32 eType,                /* Node type */

  179958.   u32 n,                    /* Content size or sub-node count */

  179959.   const char *zContent      /* Content */

  179960. ){

  179961.   JsonNode *p;

  179962.   if( pParse->nNode>=pParse->nAlloc ){

  179963.     return jsonParseAddNodeExpand(pParse, eType, n, zContent);

  179964.   }

  179965.   p = &pParse->aNode[pParse->nNode];

  179966.   p->eType = (u8)eType;

  179967.   p->jnFlags = 0;

  179968.   p->n = n;

  179969.   p->u.zJContent = zContent;

  179970.   return pParse->nNode++;

  179971. }

  179972. 

  179973. /*

  179974. ** Return true if z[] begins with 4 (or more) hexadecimal digits

  179975. */

  179976. static int jsonIs4Hex(const char *z){

  179977.   int i;

  179978.   for(i=0; i<4; i++) if( !safe_isxdigit(z[i]) ) return 0;

  179979.   return 1;

  179980. }

  179981. 

  179982. /*

  179983. ** Parse a single JSON value which begins at pParse->zJson[i].  Return the

  179984. ** index of the first character past the end of the value parsed.

  179985. **

  179986. ** Return negative for a syntax error.  Special cases:  return -2 if the

  179987. ** first non-whitespace character is '}' and return -3 if the first

  179988. ** non-whitespace character is ']'.

  179989. */

  179990. static int jsonParseValue(JsonParse *pParse, u32 i){

  179991.   char c;

  179992.   u32 j;

  179993.   int iThis;

  179994.   int x;

  179995.   JsonNode *pNode;

  179996.   const char *z = pParse->zJson;

  179997.   while( safe_isspace(z[i]) ){ i++; }

  179998.   if( (c = z[i])=='{' ){

  179999.     /* Parse object */

  180000.     iThis = jsonParseAddNode(pParse, JSON_OBJECT, 0, 0);

  180001.     if( iThis<0 ) return -1;

  180002.     for(j=i+1;;j++){

  180003.       while( safe_isspace(z[j]) ){ j++; }

  180004.       if( ++pParse->iDepth > JSON_MAX_DEPTH ) return -1;

  180005.       x = jsonParseValue(pParse, j);

  180006.       if( x<0 ){

  180007.         pParse->iDepth--;

  180008.         if( x==(-2) && pParse->nNode==(u32)iThis+1 ) return j+1;

  180009.         return -1;

  180010.       }

  180011.       if( pParse->oom ) return -1;

  180012.       pNode = &pParse->aNode[pParse->nNode-1];

  180013.       if( pNode->eType!=JSON_STRING ) return -1;

  180014.       pNode->jnFlags |= JNODE_LABEL;

  180015.       j = x;

  180016.       while( safe_isspace(z[j]) ){ j++; }

  180017.       if( z[j]!=':' ) return -1;

  180018.       j++;

  180019.       x = jsonParseValue(pParse, j);

  180020.       pParse->iDepth--;

  180021.       if( x<0 ) return -1;

  180022.       j = x;

  180023.       while( safe_isspace(z[j]) ){ j++; }

  180024.       c = z[j];

  180025.       if( c==',' ) continue;

  180026.       if( c!='}' ) return -1;

  180027.       break;

  180028.     }

  180029.     pParse->aNode[iThis].n = pParse->nNode - (u32)iThis - 1;

  180030.     return j+1;

  180031.   }else if( c=='[' ){

  180032.     /* Parse array */

  180033.     iThis = jsonParseAddNode(pParse, JSON_ARRAY, 0, 0);

  180034.     if( iThis<0 ) return -1;

  180035.     for(j=i+1;;j++){

  180036.       while( safe_isspace(z[j]) ){ j++; }

  180037.       if( ++pParse->iDepth > JSON_MAX_DEPTH ) return -1;

  180038.       x = jsonParseValue(pParse, j);

  180039.       pParse->iDepth--;

  180040.       if( x<0 ){

  180041.         if( x==(-3) && pParse->nNode==(u32)iThis+1 ) return j+1;

  180042.         return -1;

  180043.       }

  180044.       j = x;

  180045.       while( safe_isspace(z[j]) ){ j++; }

  180046.       c = z[j];

  180047.       if( c==',' ) continue;

  180048.       if( c!=']' ) return -1;

  180049.       break;

  180050.     }

  180051.     pParse->aNode[iThis].n = pParse->nNode - (u32)iThis - 1;

  180052.     return j+1;

  180053.   }else if( c=='"' ){

  180054.     /* Parse string */

  180055.     u8 jnFlags = 0;

  180056.     j = i+1;

  180057.     for(;;){

  180058.       c = z[j];

  180059.       if( (c & ~0x1f)==0 ){

  180060.         /* Control characters are not allowed in strings */

  180061.         return -1;

  180062.       }

  180063.       if( c=='\\' ){

  180064.         c = z[++j];

  180065.         if( c=='"' || c=='\\' || c=='/' || c=='b' || c=='f'

  180066.            || c=='n' || c=='r' || c=='t'

  180067.            || (c=='u' && jsonIs4Hex(z+j+1)) ){

  180068.           jnFlags = JNODE_ESCAPE;

  180069.         }else{

  180070.           return -1;

  180071.         }

  180072.       }else if( c=='"' ){

  180073.         break;

  180074.       }

  180075.       j++;

  180076.     }

  180077.     jsonParseAddNode(pParse, JSON_STRING, j+1-i, &z[i]);

  180078.     if( !pParse->oom ) pParse->aNode[pParse->nNode-1].jnFlags = jnFlags;

  180079.     return j+1;

  180080.   }else if( c=='n'

  180081.          && strncmp(z+i,"null",4)==0

  180082.          && !safe_isalnum(z[i+4]) ){

  180083.     jsonParseAddNode(pParse, JSON_NULL, 0, 0);

  180084.     return i+4;

  180085.   }else if( c=='t'

  180086.          && strncmp(z+i,"true",4)==0

  180087.          && !safe_isalnum(z[i+4]) ){

  180088.     jsonParseAddNode(pParse, JSON_TRUE, 0, 0);

  180089.     return i+4;

  180090.   }else if( c=='f'

  180091.          && strncmp(z+i,"false",5)==0

  180092.          && !safe_isalnum(z[i+5]) ){

  180093.     jsonParseAddNode(pParse, JSON_FALSE, 0, 0);

  180094.     return i+5;

  180095.   }else if( c=='-' || (c>='0' && c<='9') ){

  180096.     /* Parse number */

  180097.     u8 seenDP = 0;

  180098.     u8 seenE = 0;

  180099.     assert( '-' < '0' );

  180100.     if( c<='0' ){

  180101.       j = c=='-' ? i+1 : i;

  180102.       if( z[j]=='0' && z[j+1]>='0' && z[j+1]<='9' ) return -1;

  180103.     }

  180104.     j = i+1;

  180105.     for(;; j++){

  180106.       c = z[j];

  180107.       if( c>='0' && c<='9' ) continue;

  180108.       if( c=='.' ){

  180109.         if( z[j-1]=='-' ) return -1;

  180110.         if( seenDP ) return -1;

  180111.         seenDP = 1;

  180112.         continue;

  180113.       }

  180114.       if( c=='e' || c=='E' ){

  180115.         if( z[j-1]<'0' ) return -1;

  180116.         if( seenE ) return -1;

  180117.         seenDP = seenE = 1;

  180118.         c = z[j+1];

  180119.         if( c=='+' || c=='-' ){

  180120.           j++;

  180121.           c = z[j+1];

  180122.         }

  180123.         if( c<'0' || c>'9' ) return -1;

  180124.         continue;

  180125.       }

  180126.       break;

  180127.     }

  180128.     if( z[j-1]<'0' ) return -1;

  180129.     jsonParseAddNode(pParse, seenDP ? JSON_REAL : JSON_INT,

  180130.                         j - i, &z[i]);

  180131.     return j;

  180132.   }else if( c=='}' ){

  180133.     return -2;  /* End of {...} */

  180134.   }else if( c==']' ){

  180135.     return -3;  /* End of [...] */

  180136.   }else if( c==0 ){

  180137.     return 0;   /* End of file */

  180138.   }else{

  180139.     return -1;  /* Syntax error */

  180140.   }

  180141. }

  180142. 

  180143. /*

  180144. ** Parse a complete JSON string.  Return 0 on success or non-zero if there

  180145. ** are any errors.  If an error occurs, free all memory associated with

  180146. ** pParse.

  180147. **

  180148. ** pParse is uninitialized when this routine is called.

  180149. */

  180150. static int jsonParse(

  180151.   JsonParse *pParse,           /* Initialize and fill this JsonParse object */

  180152.   sqlite3_context *pCtx,       /* Report errors here */

  180153.   const char *zJson            /* Input JSON text to be parsed */

  180154. ){

  180155.   int i;

  180156.   memset(pParse, 0, sizeof(*pParse));

  180157.   if( zJson==0 ) return 1;

  180158.   pParse->zJson = zJson;

  180159.   i = jsonParseValue(pParse, 0);

  180160.   if( pParse->oom ) i = -1;

  180161.   if( i>0 ){

  180162.     assert( pParse->iDepth==0 );

  180163.     while( safe_isspace(zJson[i]) ) i++;

  180164.     if( zJson[i] ) i = -1;

  180165.   }

  180166.   if( i<=0 ){

  180167.     if( pCtx!=0 ){

  180168.       if( pParse->oom ){

  180169.         sqlite3_result_error_nomem(pCtx);

  180170.       }else{

  180171.         sqlite3_result_error(pCtx, "malformed JSON", -1);

  180172.       }

  180173.     }

  180174.     jsonParseReset(pParse);

  180175.     return 1;

  180176.   }

  180177.   return 0;

  180178. }

  180179. 

  180180. /* Mark node i of pParse as being a child of iParent.  Call recursively

  180181. ** to fill in all the descendants of node i.

  180182. */

  180183. static void jsonParseFillInParentage(JsonParse *pParse, u32 i, u32 iParent){

  180184.   JsonNode *pNode = &pParse->aNode[i];

  180185.   u32 j;

  180186.   pParse->aUp[i] = iParent;

  180187.   switch( pNode->eType ){

  180188.     case JSON_ARRAY: {

  180189.       for(j=1; j<=pNode->n; j += jsonNodeSize(pNode+j)){

  180190.         jsonParseFillInParentage(pParse, i+j, i);

  180191.       }

  180192.       break;

  180193.     }

  180194.     case JSON_OBJECT: {

  180195.       for(j=1; j<=pNode->n; j += jsonNodeSize(pNode+j+1)+1){

  180196.         pParse->aUp[i+j] = i;

  180197.         jsonParseFillInParentage(pParse, i+j+1, i);

  180198.       }

  180199.       break;

  180200.     }

  180201.     default: {

  180202.       break;

  180203.     }

  180204.   }

  180205. }

  180206. 

  180207. /*

  180208. ** Compute the parentage of all nodes in a completed parse.

  180209. */

  180210. static int jsonParseFindParents(JsonParse *pParse){

  180211.   u32 *aUp;

  180212.   assert( pParse->aUp==0 );

  180213.   aUp = pParse->aUp = sqlite3_malloc64( sizeof(u32)*pParse->nNode );

  180214.   if( aUp==0 ){

  180215.     pParse->oom = 1;

  180216.     return SQLITE_NOMEM;

  180217.   }

  180218.   jsonParseFillInParentage(pParse, 0, 0);

  180219.   return SQLITE_OK;

  180220. }

  180221. 

  180222. /*

  180223. ** Magic number used for the JSON parse cache in sqlite3_get_auxdata()

  180224. */

  180225. #define JSON_CACHE_ID  (-429938)  /* First cache entry */

  180226. #define JSON_CACHE_SZ  4          /* Max number of cache entries */

  180227. 

  180228. /*

  180229. ** Obtain a complete parse of the JSON found in the first argument

  180230. ** of the argv array.  Use the sqlite3_get_auxdata() cache for this

  180231. ** parse if it is available.  If the cache is not available or if it

  180232. ** is no longer valid, parse the JSON again and return the new parse,

  180233. ** and also register the new parse so that it will be available for

  180234. ** future sqlite3_get_auxdata() calls.

  180235. */

  180236. static JsonParse *jsonParseCached(

  180237.   sqlite3_context *pCtx,

  180238.   sqlite3_value **argv,

  180239.   sqlite3_context *pErrCtx

  180240. ){

  180241.   const char *zJson = (const char*)sqlite3_value_text(argv[0]);

  180242.   int nJson = sqlite3_value_bytes(argv[0]);

  180243.   JsonParse *p;

  180244.   JsonParse *pMatch = 0;

  180245.   int iKey;

  180246.   int iMinKey = 0;

  180247.   u32 iMinHold = 0xffffffff;

  180248.   u32 iMaxHold = 0;

  180249.   if( zJson==0 ) return 0;

  180250.   for(iKey=0; iKey<JSON_CACHE_SZ; iKey++){

  180251.     p = (JsonParse*)sqlite3_get_auxdata(pCtx, JSON_CACHE_ID+iKey);

  180252.     if( p==0 ){

  180253.       iMinKey = iKey;

  180254.       break;

  180255.     }

  180256.     if( pMatch==0

  180257.      && p->nJson==nJson

  180258.      && memcmp(p->zJson,zJson,nJson)==0

  180259.     ){

  180260.       p->nErr = 0;

  180261.       pMatch = p;

  180262.     }else if( p->iHold<iMinHold ){

  180263.       iMinHold = p->iHold;

  180264.       iMinKey = iKey;

  180265.     }

  180266.     if( p->iHold>iMaxHold ){

  180267.       iMaxHold = p->iHold;

  180268.     }

  180269.   }

  180270.   if( pMatch ){

  180271.     pMatch->nErr = 0;

  180272.     pMatch->iHold = iMaxHold+1;

  180273.     return pMatch;

  180274.   }

  180275.   p = sqlite3_malloc64( sizeof(*p) + nJson + 1 );

  180276.   if( p==0 ){

  180277.     sqlite3_result_error_nomem(pCtx);

  180278.     return 0;

  180279.   }

  180280.   memset(p, 0, sizeof(*p));

  180281.   p->zJson = (char*)&p[1];

  180282.   memcpy((char*)p->zJson, zJson, nJson+1);

  180283.   if( jsonParse(p, pErrCtx, p->zJson) ){

  180284.     sqlite3_free(p);

  180285.     return 0;

  180286.   }

  180287.   p->nJson = nJson;

  180288.   p->iHold = iMaxHold+1;

  180289.   sqlite3_set_auxdata(pCtx, JSON_CACHE_ID+iMinKey, p,

  180290.                       (void(*)(void*))jsonParseFree);

  180291.   return (JsonParse*)sqlite3_get_auxdata(pCtx, JSON_CACHE_ID+iMinKey);

  180292. }

  180293. 

  180294. /*

  180295. ** Compare the OBJECT label at pNode against zKey,nKey.  Return true on

  180296. ** a match.

  180297. */

  180298. static int jsonLabelCompare(JsonNode *pNode, const char *zKey, u32 nKey){

  180299.   if( pNode->jnFlags & JNODE_RAW ){

  180300.     if( pNode->n!=nKey ) return 0;

  180301.     return strncmp(pNode->u.zJContent, zKey, nKey)==0;

  180302.   }else{

  180303.     if( pNode->n!=nKey+2 ) return 0;

  180304.     return strncmp(pNode->u.zJContent+1, zKey, nKey)==0;

  180305.   }

  180306. }

  180307. 

  180308. /* forward declaration */

  180309. static JsonNode *jsonLookupAppend(JsonParse*,const char*,int*,const char**);

  180310. 

  180311. /*

  180312. ** Search along zPath to find the node specified.  Return a pointer

  180313. ** to that node, or NULL if zPath is malformed or if there is no such

  180314. ** node.

  180315. **

  180316. ** If pApnd!=0, then try to append new nodes to complete zPath if it is

  180317. ** possible to do so and if no existing node corresponds to zPath.  If

  180318. ** new nodes are appended *pApnd is set to 1.

  180319. */

  180320. static JsonNode *jsonLookupStep(

  180321.   JsonParse *pParse,      /* The JSON to search */

  180322.   u32 iRoot,              /* Begin the search at this node */

  180323.   const char *zPath,      /* The path to search */

  180324.   int *pApnd,             /* Append nodes to complete path if not NULL */

  180325.   const char **pzErr      /* Make *pzErr point to any syntax error in zPath */

  180326. ){

  180327.   u32 i, j, nKey;

  180328.   const char *zKey;

  180329.   JsonNode *pRoot = &pParse->aNode[iRoot];

  180330.   if( zPath[0]==0 ) return pRoot;

  180331.   if( zPath[0]=='.' ){

  180332.     if( pRoot->eType!=JSON_OBJECT ) return 0;

  180333.     zPath++;

  180334.     if( zPath[0]=='"' ){

  180335.       zKey = zPath + 1;

  180336.       for(i=1; zPath[i] && zPath[i]!='"'; i++){}

  180337.       nKey = i-1;

  180338.       if( zPath[i] ){

  180339.         i++;

  180340.       }else{

  180341.         *pzErr = zPath;

  180342.         return 0;

  180343.       }

  180344.     }else{

  180345.       zKey = zPath;

  180346.       for(i=0; zPath[i] && zPath[i]!='.' && zPath[i]!='['; i++){}

  180347.       nKey = i;

  180348.     }

  180349.     if( nKey==0 ){

  180350.       *pzErr = zPath;

  180351.       return 0;

  180352.     }

  180353.     j = 1;

  180354.     for(;;){

  180355.       while( j<=pRoot->n ){

  180356.         if( jsonLabelCompare(pRoot+j, zKey, nKey) ){

  180357.           return jsonLookupStep(pParse, iRoot+j+1, &zPath[i], pApnd, pzErr);

  180358.         }

  180359.         j++;

  180360.         j += jsonNodeSize(&pRoot[j]);

  180361.       }

  180362.       if( (pRoot->jnFlags & JNODE_APPEND)==0 ) break;

  180363.       iRoot += pRoot->u.iAppend;

  180364.       pRoot = &pParse->aNode[iRoot];

  180365.       j = 1;

  180366.     }

  180367.     if( pApnd ){

  180368.       u32 iStart, iLabel;

  180369.       JsonNode *pNode;

  180370.       iStart = jsonParseAddNode(pParse, JSON_OBJECT, 2, 0);

  180371.       iLabel = jsonParseAddNode(pParse, JSON_STRING, nKey, zKey);

  180372.       zPath += i;

  180373.       pNode = jsonLookupAppend(pParse, zPath, pApnd, pzErr);

  180374.       if( pParse->oom ) return 0;

  180375.       if( pNode ){

  180376.         pRoot = &pParse->aNode[iRoot];

  180377.         pRoot->u.iAppend = iStart - iRoot;

  180378.         pRoot->jnFlags |= JNODE_APPEND;

  180379.         pParse->aNode[iLabel].jnFlags |= JNODE_RAW;

  180380.       }

  180381.       return pNode;

  180382.     }

  180383.   }else if( zPath[0]=='[' && safe_isdigit(zPath[1]) ){

  180384.     if( pRoot->eType!=JSON_ARRAY ) return 0;

  180385.     i = 0;

  180386.     j = 1;

  180387.     while( safe_isdigit(zPath[j]) ){

  180388.       i = i*10 + zPath[j] - '0';

  180389.       j++;

  180390.     }

  180391.     if( zPath[j]!=']' ){

  180392.       *pzErr = zPath;

  180393.       return 0;

  180394.     }

  180395.     zPath += j + 1;

  180396.     j = 1;

  180397.     for(;;){

  180398.       while( j<=pRoot->n && (i>0 || (pRoot[j].jnFlags & JNODE_REMOVE)!=0) ){

  180399.         if( (pRoot[j].jnFlags & JNODE_REMOVE)==0 ) i--;

  180400.         j += jsonNodeSize(&pRoot[j]);

  180401.       }

  180402.       if( (pRoot->jnFlags & JNODE_APPEND)==0 ) break;

  180403.       iRoot += pRoot->u.iAppend;

  180404.       pRoot = &pParse->aNode[iRoot];

  180405.       j = 1;

  180406.     }

  180407.     if( j<=pRoot->n ){

  180408.       return jsonLookupStep(pParse, iRoot+j, zPath, pApnd, pzErr);

  180409.     }

  180410.     if( i==0 && pApnd ){

  180411.       u32 iStart;

  180412.       JsonNode *pNode;

  180413.       iStart = jsonParseAddNode(pParse, JSON_ARRAY, 1, 0);

  180414.       pNode = jsonLookupAppend(pParse, zPath, pApnd, pzErr);

  180415.       if( pParse->oom ) return 0;

  180416.       if( pNode ){

  180417.         pRoot = &pParse->aNode[iRoot];

  180418.         pRoot->u.iAppend = iStart - iRoot;

  180419.         pRoot->jnFlags |= JNODE_APPEND;

  180420.       }

  180421.       return pNode;

  180422.     }

  180423.   }else{

  180424.     *pzErr = zPath;

  180425.   }

  180426.   return 0;

  180427. }

  180428. 

  180429. /*

  180430. ** Append content to pParse that will complete zPath.  Return a pointer

  180431. ** to the inserted node, or return NULL if the append fails.

  180432. */

  180433. static JsonNode *jsonLookupAppend(

  180434.   JsonParse *pParse,     /* Append content to the JSON parse */

  180435.   const char *zPath,     /* Description of content to append */

  180436.   int *pApnd,            /* Set this flag to 1 */

  180437.   const char **pzErr     /* Make this point to any syntax error */

  180438. ){

  180439.   *pApnd = 1;

  180440.   if( zPath[0]==0 ){

  180441.     jsonParseAddNode(pParse, JSON_NULL, 0, 0);

  180442.     return pParse->oom ? 0 : &pParse->aNode[pParse->nNode-1];

  180443.   }

  180444.   if( zPath[0]=='.' ){

  180445.     jsonParseAddNode(pParse, JSON_OBJECT, 0, 0);

  180446.   }else if( strncmp(zPath,"[0]",3)==0 ){

  180447.     jsonParseAddNode(pParse, JSON_ARRAY, 0, 0);

  180448.   }else{

  180449.     return 0;

  180450.   }

  180451.   if( pParse->oom ) return 0;

  180452.   return jsonLookupStep(pParse, pParse->nNode-1, zPath, pApnd, pzErr);

  180453. }

  180454. 

  180455. /*

  180456. ** Return the text of a syntax error message on a JSON path.  Space is

  180457. ** obtained from sqlite3_malloc().

  180458. */

  180459. static char *jsonPathSyntaxError(const char *zErr){

  180460.   return sqlite3_mprintf("JSON path error near '%q'", zErr);

  180461. }

  180462. 

  180463. /*

  180464. ** Do a node lookup using zPath.  Return a pointer to the node on success.

  180465. ** Return NULL if not found or if there is an error.

  180466. **

  180467. ** On an error, write an error message into pCtx and increment the

  180468. ** pParse->nErr counter.

  180469. **

  180470. ** If pApnd!=NULL then try to append missing nodes and set *pApnd = 1 if

  180471. ** nodes are appended.

  180472. */

  180473. static JsonNode *jsonLookup(

  180474.   JsonParse *pParse,      /* The JSON to search */

  180475.   const char *zPath,      /* The path to search */

  180476.   int *pApnd,             /* Append nodes to complete path if not NULL */

  180477.   sqlite3_context *pCtx   /* Report errors here, if not NULL */

  180478. ){

  180479.   const char *zErr = 0;

  180480.   JsonNode *pNode = 0;

  180481.   char *zMsg;

  180482. 

  180483.   if( zPath==0 ) return 0;

  180484.   if( zPath[0]!='$' ){

  180485.     zErr = zPath;

  180486.     goto lookup_err;

  180487.   }

  180488.   zPath++;

  180489.   pNode = jsonLookupStep(pParse, 0, zPath, pApnd, &zErr);

  180490.   if( zErr==0 ) return pNode;

  180491. 

  180492. lookup_err:

  180493.   pParse->nErr++;

  180494.   assert( zErr!=0 && pCtx!=0 );

  180495.   zMsg = jsonPathSyntaxError(zErr);

  180496.   if( zMsg ){

  180497.     sqlite3_result_error(pCtx, zMsg, -1);

  180498.     sqlite3_free(zMsg);

  180499.   }else{

  180500.     sqlite3_result_error_nomem(pCtx);

  180501.   }

  180502.   return 0;

  180503. }

  180504. 

  180505. 

  180506. /*

  180507. ** Report the wrong number of arguments for json_insert(), json_replace()

  180508. ** or json_set().

  180509. */

  180510. static void jsonWrongNumArgs(

  180511.   sqlite3_context *pCtx,

  180512.   const char *zFuncName

  180513. ){

  180514.   char *zMsg = sqlite3_mprintf("json_%s() needs an odd number of arguments",

  180515.                                zFuncName);

  180516.   sqlite3_result_error(pCtx, zMsg, -1);

  180517.   sqlite3_free(zMsg);     

  180518. }

  180519. 

  180520. /*

  180521. ** Mark all NULL entries in the Object passed in as JNODE_REMOVE.

  180522. */

  180523. static void jsonRemoveAllNulls(JsonNode *pNode){

  180524.   int i, n;

  180525.   assert( pNode->eType==JSON_OBJECT );

  180526.   n = pNode->n;

  180527.   for(i=2; i<=n; i += jsonNodeSize(&pNode[i])+1){

  180528.     switch( pNode[i].eType ){

  180529.       case JSON_NULL:

  180530.         pNode[i].jnFlags |= JNODE_REMOVE;

  180531.         break;

  180532.       case JSON_OBJECT:

  180533.         jsonRemoveAllNulls(&pNode[i]);

  180534.         break;

  180535.     }

  180536.   }

  180537. }

  180538. 

  180539. 

  180540. /****************************************************************************

  180541. ** SQL functions used for testing and debugging

  180542. ****************************************************************************/

  180543. 

  180544. #ifdef SQLITE_DEBUG

  180545. /*

  180546. ** The json_parse(JSON) function returns a string which describes

  180547. ** a parse of the JSON provided.  Or it returns NULL if JSON is not

  180548. ** well-formed.

  180549. */

  180550. static void jsonParseFunc(

  180551.   sqlite3_context *ctx,

  180552.   int argc,

  180553.   sqlite3_value **argv

  180554. ){

  180555.   JsonString s;       /* Output string - not real JSON */

  180556.   JsonParse x;        /* The parse */

  180557.   u32 i;

  180558. 

  180559.   assert( argc==1 );

  180560.   if( jsonParse(&x, ctx, (const char*)sqlite3_value_text(argv[0])) ) return;

  180561.   jsonParseFindParents(&x);

  180562.   jsonInit(&s, ctx);

  180563.   for(i=0; i<x.nNode; i++){

  180564.     const char *zType;

  180565.     if( x.aNode[i].jnFlags & JNODE_LABEL ){

  180566.       assert( x.aNode[i].eType==JSON_STRING );

  180567.       zType = "label";

  180568.     }else{

  180569.       zType = jsonType[x.aNode[i].eType];

  180570.     }

  180571.     jsonPrintf(100, &s,"node %3u: %7s n=%-4d up=%-4d",

  180572.                i, zType, x.aNode[i].n, x.aUp[i]);

  180573.     if( x.aNode[i].u.zJContent!=0 ){

  180574.       jsonAppendRaw(&s, " ", 1);

  180575.       jsonAppendRaw(&s, x.aNode[i].u.zJContent, x.aNode[i].n);

  180576.     }

  180577.     jsonAppendRaw(&s, "\n", 1);

  180578.   }

  180579.   jsonParseReset(&x);

  180580.   jsonResult(&s);

  180581. }

  180582. 

  180583. /*

  180584. ** The json_test1(JSON) function return true (1) if the input is JSON

  180585. ** text generated by another json function.  It returns (0) if the input

  180586. ** is not known to be JSON.

  180587. */

  180588. static void jsonTest1Func(

  180589.   sqlite3_context *ctx,

  180590.   int argc,

  180591.   sqlite3_value **argv

  180592. ){

  180593.   UNUSED_PARAM(argc);

  180594.   sqlite3_result_int(ctx, sqlite3_value_subtype(argv[0])==JSON_SUBTYPE);

  180595. }

  180596. #endif /* SQLITE_DEBUG */

  180597. 

  180598. /****************************************************************************

  180599. ** Scalar SQL function implementations

  180600. ****************************************************************************/

  180601. 

  180602. /*

  180603. ** Implementation of the json_QUOTE(VALUE) function.  Return a JSON value

  180604. ** corresponding to the SQL value input.  Mostly this means putting 

  180605. ** double-quotes around strings and returning the unquoted string "null"

  180606. ** when given a NULL input.

  180607. */

  180608. static void jsonQuoteFunc(

  180609.   sqlite3_context *ctx,

  180610.   int argc,

  180611.   sqlite3_value **argv

  180612. ){

  180613.   JsonString jx;

  180614.   UNUSED_PARAM(argc);

  180615. 

  180616.   jsonInit(&jx, ctx);

  180617.   jsonAppendValue(&jx, argv[0]);

  180618.   jsonResult(&jx);

  180619.   sqlite3_result_subtype(ctx, JSON_SUBTYPE);

  180620. }

  180621. 

  180622. /*

  180623. ** Implementation of the json_array(VALUE,...) function.  Return a JSON

  180624. ** array that contains all values given in arguments.  Or if any argument

  180625. ** is a BLOB, throw an error.

  180626. */

  180627. static void jsonArrayFunc(

  180628.   sqlite3_context *ctx,

  180629.   int argc,

  180630.   sqlite3_value **argv

  180631. ){

  180632.   int i;

  180633.   JsonString jx;

  180634. 

  180635.   jsonInit(&jx, ctx);

  180636.   jsonAppendChar(&jx, '[');

  180637.   for(i=0; i<argc; i++){

  180638.     jsonAppendSeparator(&jx);

  180639.     jsonAppendValue(&jx, argv[i]);

  180640.   }

  180641.   jsonAppendChar(&jx, ']');

  180642.   jsonResult(&jx);

  180643.   sqlite3_result_subtype(ctx, JSON_SUBTYPE);

  180644. }

  180645. 

  180646. 

  180647. /*

  180648. ** json_array_length(JSON)

  180649. ** json_array_length(JSON, PATH)

  180650. **

  180651. ** Return the number of elements in the top-level JSON array.  

  180652. ** Return 0 if the input is not a well-formed JSON array.

  180653. */

  180654. static void jsonArrayLengthFunc(

  180655.   sqlite3_context *ctx,

  180656.   int argc,

  180657.   sqlite3_value **argv

  180658. ){

  180659.   JsonParse *p;          /* The parse */

  180660.   sqlite3_int64 n = 0;

  180661.   u32 i;

  180662.   JsonNode *pNode;

  180663. 

  180664.   p = jsonParseCached(ctx, argv, ctx);

  180665.   if( p==0 ) return;

  180666.   assert( p->nNode );

  180667.   if( argc==2 ){

  180668.     const char *zPath = (const char*)sqlite3_value_text(argv[1]);

  180669.     pNode = jsonLookup(p, zPath, 0, ctx);

  180670.   }else{

  180671.     pNode = p->aNode;

  180672.   }

  180673.   if( pNode==0 ){

  180674.     return;

  180675.   }

  180676.   if( pNode->eType==JSON_ARRAY ){

  180677.     assert( (pNode->jnFlags & JNODE_APPEND)==0 );

  180678.     for(i=1; i<=pNode->n; n++){

  180679.       i += jsonNodeSize(&pNode[i]);

  180680.     }

  180681.   }

  180682.   sqlite3_result_int64(ctx, n);

  180683. }

  180684. 

  180685. /*

  180686. ** json_extract(JSON, PATH, ...)

  180687. **

  180688. ** Return the element described by PATH.  Return NULL if there is no

  180689. ** PATH element.  If there are multiple PATHs, then return a JSON array

  180690. ** with the result from each path.  Throw an error if the JSON or any PATH

  180691. ** is malformed.

  180692. */

  180693. static void jsonExtractFunc(

  180694.   sqlite3_context *ctx,

  180695.   int argc,

  180696.   sqlite3_value **argv

  180697. ){

  180698.   JsonParse *p;          /* The parse */

  180699.   JsonNode *pNode;

  180700.   const char *zPath;

  180701.   JsonString jx;

  180702.   int i;

  180703. 

  180704.   if( argc<2 ) return;

  180705.   p = jsonParseCached(ctx, argv, ctx);

  180706.   if( p==0 ) return;

  180707.   jsonInit(&jx, ctx);

  180708.   jsonAppendChar(&jx, '[');

  180709.   for(i=1; i<argc; i++){

  180710.     zPath = (const char*)sqlite3_value_text(argv[i]);

  180711.     pNode = jsonLookup(p, zPath, 0, ctx);

  180712.     if( p->nErr ) break;

  180713.     if( argc>2 ){

  180714.       jsonAppendSeparator(&jx);

  180715.       if( pNode ){

  180716.         jsonRenderNode(pNode, &jx, 0);

  180717.       }else{

  180718.         jsonAppendRaw(&jx, "null", 4);

  180719.       }

  180720.     }else if( pNode ){

  180721.       jsonReturn(pNode, ctx, 0);

  180722.     }

  180723.   }

  180724.   if( argc>2 && i==argc ){

  180725.     jsonAppendChar(&jx, ']');

  180726.     jsonResult(&jx);

  180727.     sqlite3_result_subtype(ctx, JSON_SUBTYPE);

  180728.   }

  180729.   jsonReset(&jx);

  180730. }

  180731. 

  180732. /* This is the RFC 7396 MergePatch algorithm.

  180733. */

  180734. static JsonNode *jsonMergePatch(

  180735.   JsonParse *pParse,   /* The JSON parser that contains the TARGET */

  180736.   u32 iTarget,         /* Node of the TARGET in pParse */

  180737.   JsonNode *pPatch     /* The PATCH */

  180738. ){

  180739.   u32 i, j;

  180740.   u32 iRoot;

  180741.   JsonNode *pTarget;

  180742.   if( pPatch->eType!=JSON_OBJECT ){

  180743.     return pPatch;

  180744.   }

  180745.   assert( iTarget>=0 && iTarget<pParse->nNode );

  180746.   pTarget = &pParse->aNode[iTarget];

  180747.   assert( (pPatch->jnFlags & JNODE_APPEND)==0 );

  180748.   if( pTarget->eType!=JSON_OBJECT ){

  180749.     jsonRemoveAllNulls(pPatch);

  180750.     return pPatch;

  180751.   }

  180752.   iRoot = iTarget;

  180753.   for(i=1; i<pPatch->n; i += jsonNodeSize(&pPatch[i+1])+1){

  180754.     u32 nKey;

  180755.     const char *zKey;

  180756.     assert( pPatch[i].eType==JSON_STRING );

  180757.     assert( pPatch[i].jnFlags & JNODE_LABEL );

  180758.     nKey = pPatch[i].n;

  180759.     zKey = pPatch[i].u.zJContent;

  180760.     assert( (pPatch[i].jnFlags & JNODE_RAW)==0 );

  180761.     for(j=1; j<pTarget->n; j += jsonNodeSize(&pTarget[j+1])+1 ){

  180762.       assert( pTarget[j].eType==JSON_STRING );

  180763.       assert( pTarget[j].jnFlags & JNODE_LABEL );

  180764.       assert( (pPatch[i].jnFlags & JNODE_RAW)==0 );

  180765.       if( pTarget[j].n==nKey && strncmp(pTarget[j].u.zJContent,zKey,nKey)==0 ){

  180766.         if( pTarget[j+1].jnFlags & (JNODE_REMOVE|JNODE_PATCH) ) break;

  180767.         if( pPatch[i+1].eType==JSON_NULL ){

  180768.           pTarget[j+1].jnFlags |= JNODE_REMOVE;

  180769.         }else{

  180770.           JsonNode *pNew = jsonMergePatch(pParse, iTarget+j+1, &pPatch[i+1]);

  180771.           if( pNew==0 ) return 0;

  180772.           pTarget = &pParse->aNode[iTarget];

  180773.           if( pNew!=&pTarget[j+1] ){

  180774.             pTarget[j+1].u.pPatch = pNew;

  180775.             pTarget[j+1].jnFlags |= JNODE_PATCH;

  180776.           }

  180777.         }

  180778.         break;

  180779.       }

  180780.     }

  180781.     if( j>=pTarget->n && pPatch[i+1].eType!=JSON_NULL ){

  180782.       int iStart, iPatch;

  180783.       iStart = jsonParseAddNode(pParse, JSON_OBJECT, 2, 0);

  180784.       jsonParseAddNode(pParse, JSON_STRING, nKey, zKey);

  180785.       iPatch = jsonParseAddNode(pParse, JSON_TRUE, 0, 0);

  180786.       if( pParse->oom ) return 0;

  180787.       jsonRemoveAllNulls(pPatch);

  180788.       pTarget = &pParse->aNode[iTarget];

  180789.       pParse->aNode[iRoot].jnFlags |= JNODE_APPEND;

  180790.       pParse->aNode[iRoot].u.iAppend = iStart - iRoot;

  180791.       iRoot = iStart;

  180792.       pParse->aNode[iPatch].jnFlags |= JNODE_PATCH;

  180793.       pParse->aNode[iPatch].u.pPatch = &pPatch[i+1];

  180794.     }

  180795.   }

  180796.   return pTarget;

  180797. }

  180798. 

  180799. /*

  180800. ** Implementation of the json_mergepatch(JSON1,JSON2) function.  Return a JSON

  180801. ** object that is the result of running the RFC 7396 MergePatch() algorithm

  180802. ** on the two arguments.

  180803. */

  180804. static void jsonPatchFunc(

  180805.   sqlite3_context *ctx,

  180806.   int argc,

  180807.   sqlite3_value **argv

  180808. ){

  180809.   JsonParse x;     /* The JSON that is being patched */

  180810.   JsonParse y;     /* The patch */

  180811.   JsonNode *pResult;   /* The result of the merge */

  180812. 

  180813.   UNUSED_PARAM(argc);

  180814.   if( jsonParse(&x, ctx, (const char*)sqlite3_value_text(argv[0])) ) return;

  180815.   if( jsonParse(&y, ctx, (const char*)sqlite3_value_text(argv[1])) ){

  180816.     jsonParseReset(&x);

  180817.     return;

  180818.   }

  180819.   pResult = jsonMergePatch(&x, 0, y.aNode);

  180820.   assert( pResult!=0 || x.oom );

  180821.   if( pResult ){

  180822.     jsonReturnJson(pResult, ctx, 0);

  180823.   }else{

  180824.     sqlite3_result_error_nomem(ctx);

  180825.   }

  180826.   jsonParseReset(&x);

  180827.   jsonParseReset(&y);

  180828. }

  180829. 

  180830. 

  180831. /*

  180832. ** Implementation of the json_object(NAME,VALUE,...) function.  Return a JSON

  180833. ** object that contains all name/value given in arguments.  Or if any name

  180834. ** is not a string or if any value is a BLOB, throw an error.

  180835. */

  180836. static void jsonObjectFunc(

  180837.   sqlite3_context *ctx,

  180838.   int argc,

  180839.   sqlite3_value **argv

  180840. ){

  180841.   int i;

  180842.   JsonString jx;

  180843.   const char *z;

  180844.   u32 n;

  180845. 

  180846.   if( argc&1 ){

  180847.     sqlite3_result_error(ctx, "json_object() requires an even number "

  180848.                                   "of arguments", -1);

  180849.     return;

  180850.   }

  180851.   jsonInit(&jx, ctx);

  180852.   jsonAppendChar(&jx, '{');

  180853.   for(i=0; i<argc; i+=2){

  180854.     if( sqlite3_value_type(argv[i])!=SQLITE_TEXT ){

  180855.       sqlite3_result_error(ctx, "json_object() labels must be TEXT", -1);

  180856.       jsonReset(&jx);

  180857.       return;

  180858.     }

  180859.     jsonAppendSeparator(&jx);

  180860.     z = (const char*)sqlite3_value_text(argv[i]);

  180861.     n = (u32)sqlite3_value_bytes(argv[i]);

  180862.     jsonAppendString(&jx, z, n);

  180863.     jsonAppendChar(&jx, ':');

  180864.     jsonAppendValue(&jx, argv[i+1]);

  180865.   }

  180866.   jsonAppendChar(&jx, '}');

  180867.   jsonResult(&jx);

  180868.   sqlite3_result_subtype(ctx, JSON_SUBTYPE);

  180869. }

  180870. 

  180871. 

  180872. /*

  180873. ** json_remove(JSON, PATH, ...)

  180874. **

  180875. ** Remove the named elements from JSON and return the result.  malformed

  180876. ** JSON or PATH arguments result in an error.

  180877. */

  180878. static void jsonRemoveFunc(

  180879.   sqlite3_context *ctx,

  180880.   int argc,

  180881.   sqlite3_value **argv

  180882. ){

  180883.   JsonParse x;          /* The parse */

  180884.   JsonNode *pNode;

  180885.   const char *zPath;

  180886.   u32 i;

  180887. 

  180888.   if( argc<1 ) return;

  180889.   if( jsonParse(&x, ctx, (const char*)sqlite3_value_text(argv[0])) ) return;

  180890.   assert( x.nNode );

  180891.   for(i=1; i<(u32)argc; i++){

  180892.     zPath = (const char*)sqlite3_value_text(argv[i]);

  180893.     if( zPath==0 ) goto remove_done;

  180894.     pNode = jsonLookup(&x, zPath, 0, ctx);

  180895.     if( x.nErr ) goto remove_done;

  180896.     if( pNode ) pNode->jnFlags |= JNODE_REMOVE;

  180897.   }

  180898.   if( (x.aNode[0].jnFlags & JNODE_REMOVE)==0 ){

  180899.     jsonReturnJson(x.aNode, ctx, 0);

  180900.   }

  180901. remove_done:

  180902.   jsonParseReset(&x);

  180903. }

  180904. 

  180905. /*

  180906. ** json_replace(JSON, PATH, VALUE, ...)

  180907. **

  180908. ** Replace the value at PATH with VALUE.  If PATH does not already exist,

  180909. ** this routine is a no-op.  If JSON or PATH is malformed, throw an error.

  180910. */

  180911. static void jsonReplaceFunc(

  180912.   sqlite3_context *ctx,

  180913.   int argc,

  180914.   sqlite3_value **argv

  180915. ){

  180916.   JsonParse x;          /* The parse */

  180917.   JsonNode *pNode;

  180918.   const char *zPath;

  180919.   u32 i;

  180920. 

  180921.   if( argc<1 ) return;

  180922.   if( (argc&1)==0 ) {

  180923.     jsonWrongNumArgs(ctx, "replace");

  180924.     return;

  180925.   }

  180926.   if( jsonParse(&x, ctx, (const char*)sqlite3_value_text(argv[0])) ) return;

  180927.   assert( x.nNode );

  180928.   for(i=1; i<(u32)argc; i+=2){

  180929.     zPath = (const char*)sqlite3_value_text(argv[i]);

  180930.     pNode = jsonLookup(&x, zPath, 0, ctx);

  180931.     if( x.nErr ) goto replace_err;

  180932.     if( pNode ){

  180933.       pNode->jnFlags |= (u8)JNODE_REPLACE;

  180934.       pNode->u.iReplace = i + 1;

  180935.     }

  180936.   }

  180937.   if( x.aNode[0].jnFlags & JNODE_REPLACE ){

  180938.     sqlite3_result_value(ctx, argv[x.aNode[0].u.iReplace]);

  180939.   }else{

  180940.     jsonReturnJson(x.aNode, ctx, argv);

  180941.   }

  180942. replace_err:

  180943.   jsonParseReset(&x);

  180944. }

  180945. 

  180946. /*

  180947. ** json_set(JSON, PATH, VALUE, ...)

  180948. **

  180949. ** Set the value at PATH to VALUE.  Create the PATH if it does not already

  180950. ** exist.  Overwrite existing values that do exist.

  180951. ** If JSON or PATH is malformed, throw an error.

  180952. **

  180953. ** json_insert(JSON, PATH, VALUE, ...)

  180954. **

  180955. ** Create PATH and initialize it to VALUE.  If PATH already exists, this

  180956. ** routine is a no-op.  If JSON or PATH is malformed, throw an error.

  180957. */

  180958. static void jsonSetFunc(

  180959.   sqlite3_context *ctx,

  180960.   int argc,

  180961.   sqlite3_value **argv

  180962. ){

  180963.   JsonParse x;          /* The parse */

  180964.   JsonNode *pNode;

  180965.   const char *zPath;

  180966.   u32 i;

  180967.   int bApnd;

  180968.   int bIsSet = *(int*)sqlite3_user_data(ctx);

  180969. 

  180970.   if( argc<1 ) return;

  180971.   if( (argc&1)==0 ) {

  180972.     jsonWrongNumArgs(ctx, bIsSet ? "set" : "insert");

  180973.     return;

  180974.   }

  180975.   if( jsonParse(&x, ctx, (const char*)sqlite3_value_text(argv[0])) ) return;

  180976.   assert( x.nNode );

  180977.   for(i=1; i<(u32)argc; i+=2){

  180978.     zPath = (const char*)sqlite3_value_text(argv[i]);

  180979.     bApnd = 0;

  180980.     pNode = jsonLookup(&x, zPath, &bApnd, ctx);

  180981.     if( x.oom ){

  180982.       sqlite3_result_error_nomem(ctx);

  180983.       goto jsonSetDone;

  180984.     }else if( x.nErr ){

  180985.       goto jsonSetDone;

  180986.     }else if( pNode && (bApnd || bIsSet) ){

  180987.       pNode->jnFlags |= (u8)JNODE_REPLACE;

  180988.       pNode->u.iReplace = i + 1;

  180989.     }

  180990.   }

  180991.   if( x.aNode[0].jnFlags & JNODE_REPLACE ){

  180992.     sqlite3_result_value(ctx, argv[x.aNode[0].u.iReplace]);

  180993.   }else{

  180994.     jsonReturnJson(x.aNode, ctx, argv);

  180995.   }

  180996. jsonSetDone:

  180997.   jsonParseReset(&x);

  180998. }

  180999. 

  181000. /*

  181001. ** json_type(JSON)

  181002. ** json_type(JSON, PATH)

  181003. **

  181004. ** Return the top-level "type" of a JSON string.  Throw an error if

  181005. ** either the JSON or PATH inputs are not well-formed.

  181006. */

  181007. static void jsonTypeFunc(

  181008.   sqlite3_context *ctx,

  181009.   int argc,

  181010.   sqlite3_value **argv

  181011. ){

  181012.   JsonParse *p;          /* The parse */

  181013.   const char *zPath;

  181014.   JsonNode *pNode;

  181015. 

  181016.   p = jsonParseCached(ctx, argv, ctx);

  181017.   if( p==0 ) return;

  181018.   if( argc==2 ){

  181019.     zPath = (const char*)sqlite3_value_text(argv[1]);

  181020.     pNode = jsonLookup(p, zPath, 0, ctx);

  181021.   }else{

  181022.     pNode = p->aNode;

  181023.   }

  181024.   if( pNode ){

  181025.     sqlite3_result_text(ctx, jsonType[pNode->eType], -1, SQLITE_STATIC);

  181026.   }

  181027. }

  181028. 

  181029. /*

  181030. ** json_valid(JSON)

  181031. **

  181032. ** Return 1 if JSON is a well-formed JSON string according to RFC-7159.

  181033. ** Return 0 otherwise.

  181034. */

  181035. static void jsonValidFunc(

  181036.   sqlite3_context *ctx,

  181037.   int argc,

  181038.   sqlite3_value **argv

  181039. ){

  181040.   JsonParse *p;          /* The parse */

  181041.   UNUSED_PARAM(argc);

  181042.   p = jsonParseCached(ctx, argv, 0);

  181043.   sqlite3_result_int(ctx, p!=0);

  181044. }

  181045. 

  181046. 

  181047. /****************************************************************************

  181048. ** Aggregate SQL function implementations

  181049. ****************************************************************************/

  181050. /*

  181051. ** json_group_array(VALUE)

  181052. **

  181053. ** Return a JSON array composed of all values in the aggregate.

  181054. */

  181055. static void jsonArrayStep(

  181056.   sqlite3_context *ctx,

  181057.   int argc,

  181058.   sqlite3_value **argv

  181059. ){

  181060.   JsonString *pStr;

  181061.   UNUSED_PARAM(argc);

  181062.   pStr = (JsonString*)sqlite3_aggregate_context(ctx, sizeof(*pStr));

  181063.   if( pStr ){

  181064.     if( pStr->zBuf==0 ){

  181065.       jsonInit(pStr, ctx);

  181066.       jsonAppendChar(pStr, '[');

  181067.     }else{

  181068.       jsonAppendChar(pStr, ',');

  181069.       pStr->pCtx = ctx;

  181070.     }

  181071.     jsonAppendValue(pStr, argv[0]);

  181072.   }

  181073. }

  181074. static void jsonArrayCompute(sqlite3_context *ctx, int isFinal){

  181075.   JsonString *pStr;

  181076.   pStr = (JsonString*)sqlite3_aggregate_context(ctx, 0);

  181077.   if( pStr ){

  181078.     pStr->pCtx = ctx;

  181079.     jsonAppendChar(pStr, ']');

  181080.     if( pStr->bErr ){

  181081.       if( pStr->bErr==1 ) sqlite3_result_error_nomem(ctx);

  181082.       assert( pStr->bStatic );

  181083.     }else if( isFinal ){

  181084.       sqlite3_result_text(ctx, pStr->zBuf, (int)pStr->nUsed,

  181085.                           pStr->bStatic ? SQLITE_TRANSIENT : sqlite3_free);

  181086.       pStr->bStatic = 1;

  181087.     }else{

  181088.       sqlite3_result_text(ctx, pStr->zBuf, (int)pStr->nUsed, SQLITE_TRANSIENT);

  181089.       pStr->nUsed--;

  181090.     }

  181091.   }else{

  181092.     sqlite3_result_text(ctx, "[]", 2, SQLITE_STATIC);

  181093.   }

  181094.   sqlite3_result_subtype(ctx, JSON_SUBTYPE);

  181095. }

  181096. static void jsonArrayValue(sqlite3_context *ctx){

  181097.   jsonArrayCompute(ctx, 0);

  181098. }

  181099. static void jsonArrayFinal(sqlite3_context *ctx){

  181100.   jsonArrayCompute(ctx, 1);

  181101. }

  181102. 

  181103. #ifndef SQLITE_OMIT_WINDOWFUNC

  181104. /*

  181105. ** This method works for both json_group_array() and json_group_object().

  181106. ** It works by removing the first element of the group by searching forward

  181107. ** to the first comma (",") that is not within a string and deleting all

  181108. ** text through that comma.

  181109. */

  181110. static void jsonGroupInverse(

  181111.   sqlite3_context *ctx,

  181112.   int argc,

  181113.   sqlite3_value **argv

  181114. ){

  181115.   int i;

  181116.   int inStr = 0;

  181117.   char *z;

  181118.   JsonString *pStr;

  181119.   UNUSED_PARAM(argc);

  181120.   UNUSED_PARAM(argv);

  181121.   pStr = (JsonString*)sqlite3_aggregate_context(ctx, 0);

  181122. #ifdef NEVER

  181123.   /* pStr is always non-NULL since jsonArrayStep() or jsonObjectStep() will

  181124.   ** always have been called to initalize it */

  181125.   if( NEVER(!pStr) ) return;

  181126. #endif

  181127.   z = pStr->zBuf;

  181128.   for(i=1; z[i]!=',' || inStr; i++){

  181129.     assert( i<pStr->nUsed );

  181130.     if( z[i]=='"' ){

  181131.       inStr = !inStr;

  181132.     }else if( z[i]=='\\' ){

  181133.       i++;

  181134.     }

  181135.   }

  181136.   pStr->nUsed -= i;      

  181137.   memmove(&z[1], &z[i+1], (size_t)pStr->nUsed-1);

  181138. }

  181139. #else

  181140. # define jsonGroupInverse 0

  181141. #endif

  181142. 

  181143. 

  181144. /*

  181145. ** json_group_obj(NAME,VALUE)

  181146. **

  181147. ** Return a JSON object composed of all names and values in the aggregate.

  181148. */

  181149. static void jsonObjectStep(

  181150.   sqlite3_context *ctx,

  181151.   int argc,

  181152.   sqlite3_value **argv

  181153. ){

  181154.   JsonString *pStr;

  181155.   const char *z;

  181156.   u32 n;

  181157.   UNUSED_PARAM(argc);

  181158.   pStr = (JsonString*)sqlite3_aggregate_context(ctx, sizeof(*pStr));

  181159.   if( pStr ){

  181160.     if( pStr->zBuf==0 ){

  181161.       jsonInit(pStr, ctx);

  181162.       jsonAppendChar(pStr, '{');

  181163.     }else{

  181164.       jsonAppendChar(pStr, ',');

  181165.       pStr->pCtx = ctx;

  181166.     }

  181167.     z = (const char*)sqlite3_value_text(argv[0]);

  181168.     n = (u32)sqlite3_value_bytes(argv[0]);

  181169.     jsonAppendString(pStr, z, n);

  181170.     jsonAppendChar(pStr, ':');

  181171.     jsonAppendValue(pStr, argv[1]);

  181172.   }

  181173. }

  181174. static void jsonObjectCompute(sqlite3_context *ctx, int isFinal){

  181175.   JsonString *pStr;

  181176.   pStr = (JsonString*)sqlite3_aggregate_context(ctx, 0);

  181177.   if( pStr ){

  181178.     jsonAppendChar(pStr, '}');

  181179.     if( pStr->bErr ){

  181180.       if( pStr->bErr==1 ) sqlite3_result_error_nomem(ctx);

  181181.       assert( pStr->bStatic );

  181182.     }else if( isFinal ){

  181183.       sqlite3_result_text(ctx, pStr->zBuf, (int)pStr->nUsed,

  181184.                           pStr->bStatic ? SQLITE_TRANSIENT : sqlite3_free);

  181185.       pStr->bStatic = 1;

  181186.     }else{

  181187.       sqlite3_result_text(ctx, pStr->zBuf, (int)pStr->nUsed, SQLITE_TRANSIENT);

  181188.       pStr->nUsed--;

  181189.     }

  181190.   }else{

  181191.     sqlite3_result_text(ctx, "{}", 2, SQLITE_STATIC);

  181192.   }

  181193.   sqlite3_result_subtype(ctx, JSON_SUBTYPE);

  181194. }

  181195. static void jsonObjectValue(sqlite3_context *ctx){

  181196.   jsonObjectCompute(ctx, 0);

  181197. }

  181198. static void jsonObjectFinal(sqlite3_context *ctx){

  181199.   jsonObjectCompute(ctx, 1);

  181200. }

  181201. 

  181202. 

  181203. 

  181204. #ifndef SQLITE_OMIT_VIRTUALTABLE

  181205. /****************************************************************************

  181206. ** The json_each virtual table

  181207. ****************************************************************************/

  181208. typedef struct JsonEachCursor JsonEachCursor;

  181209. struct JsonEachCursor {

  181210.   sqlite3_vtab_cursor base;  /* Base class - must be first */

  181211.   u32 iRowid;                /* The rowid */

  181212.   u32 iBegin;                /* The first node of the scan */

  181213.   u32 i;                     /* Index in sParse.aNode[] of current row */

  181214.   u32 iEnd;                  /* EOF when i equals or exceeds this value */

  181215.   u8 eType;                  /* Type of top-level element */

  181216.   u8 bRecursive;             /* True for json_tree().  False for json_each() */

  181217.   char *zJson;               /* Input JSON */

  181218.   char *zRoot;               /* Path by which to filter zJson */

  181219.   JsonParse sParse;          /* Parse of the input JSON */

  181220. };

  181221. 

  181222. /* Constructor for the json_each virtual table */

  181223. static int jsonEachConnect(

  181224.   sqlite3 *db,

  181225.   void *pAux,

  181226.   int argc, const char *const*argv,

  181227.   sqlite3_vtab **ppVtab,

  181228.   char **pzErr

  181229. ){

  181230.   sqlite3_vtab *pNew;

  181231.   int rc;

  181232. 

  181233. /* Column numbers */

  181234. #define JEACH_KEY     0

  181235. #define JEACH_VALUE   1

  181236. #define JEACH_TYPE    2

  181237. #define JEACH_ATOM    3

  181238. #define JEACH_ID      4

  181239. #define JEACH_PARENT  5

  181240. #define JEACH_FULLKEY 6

  181241. #define JEACH_PATH    7

  181242. /* The xBestIndex method assumes that the JSON and ROOT columns are

  181243. ** the last two columns in the table.  Should this ever changes, be

  181244. ** sure to update the xBestIndex method. */

  181245. #define JEACH_JSON    8

  181246. #define JEACH_ROOT    9

  181247. 

  181248.   UNUSED_PARAM(pzErr);

  181249.   UNUSED_PARAM(argv);

  181250.   UNUSED_PARAM(argc);

  181251.   UNUSED_PARAM(pAux);

  181252.   rc = sqlite3_declare_vtab(db, 

  181253.      "CREATE TABLE x(key,value,type,atom,id,parent,fullkey,path,"

  181254.                     "json HIDDEN,root HIDDEN)");

  181255.   if( rc==SQLITE_OK ){

  181256.     pNew = *ppVtab = sqlite3_malloc( sizeof(*pNew) );

  181257.     if( pNew==0 ) return SQLITE_NOMEM;

  181258.     memset(pNew, 0, sizeof(*pNew));

  181259.   }

  181260.   return rc;

  181261. }

  181262. 

  181263. /* destructor for json_each virtual table */

  181264. static int jsonEachDisconnect(sqlite3_vtab *pVtab){

  181265.   sqlite3_free(pVtab);

  181266.   return SQLITE_OK;

  181267. }

  181268. 

  181269. /* constructor for a JsonEachCursor object for json_each(). */

  181270. static int jsonEachOpenEach(sqlite3_vtab *p, sqlite3_vtab_cursor **ppCursor){

  181271.   JsonEachCursor *pCur;

  181272. 

  181273.   UNUSED_PARAM(p);

  181274.   pCur = sqlite3_malloc( sizeof(*pCur) );

  181275.   if( pCur==0 ) return SQLITE_NOMEM;

  181276.   memset(pCur, 0, sizeof(*pCur));

  181277.   *ppCursor = &pCur->base;

  181278.   return SQLITE_OK;

  181279. }

  181280. 

  181281. /* constructor for a JsonEachCursor object for json_tree(). */

  181282. static int jsonEachOpenTree(sqlite3_vtab *p, sqlite3_vtab_cursor **ppCursor){

  181283.   int rc = jsonEachOpenEach(p, ppCursor);

  181284.   if( rc==SQLITE_OK ){

  181285.     JsonEachCursor *pCur = (JsonEachCursor*)*ppCursor;

  181286.     pCur->bRecursive = 1;

  181287.   }

  181288.   return rc;

  181289. }

  181290. 

  181291. /* Reset a JsonEachCursor back to its original state.  Free any memory

  181292. ** held. */

  181293. static void jsonEachCursorReset(JsonEachCursor *p){

  181294.   sqlite3_free(p->zJson);

  181295.   sqlite3_free(p->zRoot);

  181296.   jsonParseReset(&p->sParse);

  181297.   p->iRowid = 0;

  181298.   p->i = 0;

  181299.   p->iEnd = 0;

  181300.   p->eType = 0;

  181301.   p->zJson = 0;

  181302.   p->zRoot = 0;

  181303. }

  181304. 

  181305. /* Destructor for a jsonEachCursor object */

  181306. static int jsonEachClose(sqlite3_vtab_cursor *cur){

  181307.   JsonEachCursor *p = (JsonEachCursor*)cur;

  181308.   jsonEachCursorReset(p);

  181309.   sqlite3_free(cur);

  181310.   return SQLITE_OK;

  181311. }

  181312. 

  181313. /* Return TRUE if the jsonEachCursor object has been advanced off the end

  181314. ** of the JSON object */

  181315. static int jsonEachEof(sqlite3_vtab_cursor *cur){

  181316.   JsonEachCursor *p = (JsonEachCursor*)cur;

  181317.   return p->i >= p->iEnd;

  181318. }

  181319. 

  181320. /* Advance the cursor to the next element for json_tree() */

  181321. static int jsonEachNext(sqlite3_vtab_cursor *cur){

  181322.   JsonEachCursor *p = (JsonEachCursor*)cur;

  181323.   if( p->bRecursive ){

  181324.     if( p->sParse.aNode[p->i].jnFlags & JNODE_LABEL ) p->i++;

  181325.     p->i++;

  181326.     p->iRowid++;

  181327.     if( p->i<p->iEnd ){

  181328.       u32 iUp = p->sParse.aUp[p->i];

  181329.       JsonNode *pUp = &p->sParse.aNode[iUp];

  181330.       p->eType = pUp->eType;

  181331.       if( pUp->eType==JSON_ARRAY ){

  181332.         if( iUp==p->i-1 ){

  181333.           pUp->u.iKey = 0;

  181334.         }else{

  181335.           pUp->u.iKey++;

  181336.         }

  181337.       }

  181338.     }

  181339.   }else{

  181340.     switch( p->eType ){

  181341.       case JSON_ARRAY: {

  181342.         p->i += jsonNodeSize(&p->sParse.aNode[p->i]);

  181343.         p->iRowid++;

  181344.         break;

  181345.       }

  181346.       case JSON_OBJECT: {

  181347.         p->i += 1 + jsonNodeSize(&p->sParse.aNode[p->i+1]);

  181348.         p->iRowid++;

  181349.         break;

  181350.       }

  181351.       default: {

  181352.         p->i = p->iEnd;

  181353.         break;

  181354.       }

  181355.     }

  181356.   }

  181357.   return SQLITE_OK;

  181358. }

  181359. 

  181360. /* Append the name of the path for element i to pStr

  181361. */

  181362. static void jsonEachComputePath(

  181363.   JsonEachCursor *p,       /* The cursor */

  181364.   JsonString *pStr,        /* Write the path here */

  181365.   u32 i                    /* Path to this element */

  181366. ){

  181367.   JsonNode *pNode, *pUp;

  181368.   u32 iUp;

  181369.   if( i==0 ){

  181370.     jsonAppendChar(pStr, '$');

  181371.     return;

  181372.   }

  181373.   iUp = p->sParse.aUp[i];

  181374.   jsonEachComputePath(p, pStr, iUp);

  181375.   pNode = &p->sParse.aNode[i];

  181376.   pUp = &p->sParse.aNode[iUp];

  181377.   if( pUp->eType==JSON_ARRAY ){

  181378.     jsonPrintf(30, pStr, "[%d]", pUp->u.iKey);

  181379.   }else{

  181380.     assert( pUp->eType==JSON_OBJECT );

  181381.     if( (pNode->jnFlags & JNODE_LABEL)==0 ) pNode--;

  181382.     assert( pNode->eType==JSON_STRING );

  181383.     assert( pNode->jnFlags & JNODE_LABEL );

  181384.     jsonPrintf(pNode->n+1, pStr, ".%.*s", pNode->n-2, pNode->u.zJContent+1);

  181385.   }

  181386. }

  181387. 

  181388. /* Return the value of a column */

  181389. static int jsonEachColumn(

  181390.   sqlite3_vtab_cursor *cur,   /* The cursor */

  181391.   sqlite3_context *ctx,       /* First argument to sqlite3_result_...() */

  181392.   int i                       /* Which column to return */

  181393. ){

  181394.   JsonEachCursor *p = (JsonEachCursor*)cur;

  181395.   JsonNode *pThis = &p->sParse.aNode[p->i];

  181396.   switch( i ){

  181397.     case JEACH_KEY: {

  181398.       if( p->i==0 ) break;

  181399.       if( p->eType==JSON_OBJECT ){

  181400.         jsonReturn(pThis, ctx, 0);

  181401.       }else if( p->eType==JSON_ARRAY ){

  181402.         u32 iKey;

  181403.         if( p->bRecursive ){

  181404.           if( p->iRowid==0 ) break;

  181405.           iKey = p->sParse.aNode[p->sParse.aUp[p->i]].u.iKey;

  181406.         }else{

  181407.           iKey = p->iRowid;

  181408.         }

  181409.         sqlite3_result_int64(ctx, (sqlite3_int64)iKey);

  181410.       }

  181411.       break;

  181412.     }

  181413.     case JEACH_VALUE: {

  181414.       if( pThis->jnFlags & JNODE_LABEL ) pThis++;

  181415.       jsonReturn(pThis, ctx, 0);

  181416.       break;

  181417.     }

  181418.     case JEACH_TYPE: {

  181419.       if( pThis->jnFlags & JNODE_LABEL ) pThis++;

  181420.       sqlite3_result_text(ctx, jsonType[pThis->eType], -1, SQLITE_STATIC);

  181421.       break;

  181422.     }

  181423.     case JEACH_ATOM: {

  181424.       if( pThis->jnFlags & JNODE_LABEL ) pThis++;

  181425.       if( pThis->eType>=JSON_ARRAY ) break;

  181426.       jsonReturn(pThis, ctx, 0);

  181427.       break;

  181428.     }

  181429.     case JEACH_ID: {

  181430.       sqlite3_result_int64(ctx, 

  181431.          (sqlite3_int64)p->i + ((pThis->jnFlags & JNODE_LABEL)!=0));

  181432.       break;

  181433.     }

  181434.     case JEACH_PARENT: {

  181435.       if( p->i>p->iBegin && p->bRecursive ){

  181436.         sqlite3_result_int64(ctx, (sqlite3_int64)p->sParse.aUp[p->i]);

  181437.       }

  181438.       break;

  181439.     }

  181440.     case JEACH_FULLKEY: {

  181441.       JsonString x;

  181442.       jsonInit(&x, ctx);

  181443.       if( p->bRecursive ){

  181444.         jsonEachComputePath(p, &x, p->i);

  181445.       }else{

  181446.         if( p->zRoot ){

  181447.           jsonAppendRaw(&x, p->zRoot, (int)strlen(p->zRoot));

  181448.         }else{

  181449.           jsonAppendChar(&x, '$');

  181450.         }

  181451.         if( p->eType==JSON_ARRAY ){

  181452.           jsonPrintf(30, &x, "[%d]", p->iRowid);

  181453.         }else if( p->eType==JSON_OBJECT ){

  181454.           jsonPrintf(pThis->n, &x, ".%.*s", pThis->n-2, pThis->u.zJContent+1);

  181455.         }

  181456.       }

  181457.       jsonResult(&x);

  181458.       break;

  181459.     }

  181460.     case JEACH_PATH: {

  181461.       if( p->bRecursive ){

  181462.         JsonString x;

  181463.         jsonInit(&x, ctx);

  181464.         jsonEachComputePath(p, &x, p->sParse.aUp[p->i]);

  181465.         jsonResult(&x);

  181466.         break;

  181467.       }

  181468.       /* For json_each() path and root are the same so fall through

  181469.       ** into the root case */

  181470.     }

  181471.     default: {

  181472.       const char *zRoot = p->zRoot;

  181473.       if( zRoot==0 ) zRoot = "$";

  181474.       sqlite3_result_text(ctx, zRoot, -1, SQLITE_STATIC);

  181475.       break;

  181476.     }

  181477.     case JEACH_JSON: {

  181478.       assert( i==JEACH_JSON );

  181479.       sqlite3_result_text(ctx, p->sParse.zJson, -1, SQLITE_STATIC);

  181480.       break;

  181481.     }

  181482.   }

  181483.   return SQLITE_OK;

  181484. }

  181485. 

  181486. /* Return the current rowid value */

  181487. static int jsonEachRowid(sqlite3_vtab_cursor *cur, sqlite_int64 *pRowid){

  181488.   JsonEachCursor *p = (JsonEachCursor*)cur;

  181489.   *pRowid = p->iRowid;

  181490.   return SQLITE_OK;

  181491. }

  181492. 

  181493. /* The query strategy is to look for an equality constraint on the json

  181494. ** column.  Without such a constraint, the table cannot operate.  idxNum is

  181495. ** 1 if the constraint is found, 3 if the constraint and zRoot are found,

  181496. ** and 0 otherwise.

  181497. */

  181498. static int jsonEachBestIndex(

  181499.   sqlite3_vtab *tab,

  181500.   sqlite3_index_info *pIdxInfo

  181501. ){

  181502.   int i;                     /* Loop counter or computed array index */

  181503.   int aIdx[2];               /* Index of constraints for JSON and ROOT */

  181504.   int unusableMask = 0;      /* Mask of unusable JSON and ROOT constraints */

  181505.   int idxMask = 0;           /* Mask of usable == constraints JSON and ROOT */

  181506.   const struct sqlite3_index_constraint *pConstraint;

  181507. 

  181508.   /* This implementation assumes that JSON and ROOT are the last two

  181509.   ** columns in the table */

  181510.   assert( JEACH_ROOT == JEACH_JSON+1 );

  181511.   UNUSED_PARAM(tab);

  181512.   aIdx[0] = aIdx[1] = -1;

  181513.   pConstraint = pIdxInfo->aConstraint;

  181514.   for(i=0; i<pIdxInfo->nConstraint; i++, pConstraint++){

  181515.     int iCol;

  181516.     int iMask;

  181517.     if( pConstraint->iColumn < JEACH_JSON ) continue;

  181518.     iCol = pConstraint->iColumn - JEACH_JSON;

  181519.     assert( iCol==0 || iCol==1 );

  181520.     iMask = 1 << iCol;

  181521.     if( pConstraint->usable==0 ){

  181522.       unusableMask |= iMask;

  181523.     }else if( pConstraint->op==SQLITE_INDEX_CONSTRAINT_EQ ){

  181524.       aIdx[iCol] = i;

  181525.       idxMask |= iMask;

  181526.     }

  181527.   }

  181528.   if( (unusableMask & ~idxMask)!=0 ){

  181529.     /* If there are any unusable constraints on JSON or ROOT, then reject

  181530.     ** this entire plan */

  181531.     return SQLITE_CONSTRAINT;

  181532.   }

  181533.   if( aIdx[0]<0 ){

  181534.     /* No JSON input.  Leave estimatedCost at the huge value that it was

  181535.     ** initialized to to discourage the query planner from selecting this

  181536.     ** plan. */

  181537.     pIdxInfo->idxNum = 0;

  181538.   }else{

  181539.     pIdxInfo->estimatedCost = 1.0;

  181540.     i = aIdx[0];

  181541.     pIdxInfo->aConstraintUsage[i].argvIndex = 1;

  181542.     pIdxInfo->aConstraintUsage[i].omit = 1;

  181543.     if( aIdx[1]<0 ){

  181544.       pIdxInfo->idxNum = 1;  /* Only JSON supplied.  Plan 1 */

  181545.     }else{

  181546.       i = aIdx[1];

  181547.       pIdxInfo->aConstraintUsage[i].argvIndex = 2;

  181548.       pIdxInfo->aConstraintUsage[i].omit = 1;

  181549.       pIdxInfo->idxNum = 3;  /* Both JSON and ROOT are supplied.  Plan 3 */

  181550.     }

  181551.   }

  181552.   return SQLITE_OK;

  181553. }

  181554. 

  181555. /* Start a search on a new JSON string */

  181556. static int jsonEachFilter(

  181557.   sqlite3_vtab_cursor *cur,

  181558.   int idxNum, const char *idxStr,

  181559.   int argc, sqlite3_value **argv

  181560. ){

  181561.   JsonEachCursor *p = (JsonEachCursor*)cur;

  181562.   const char *z;

  181563.   const char *zRoot = 0;

  181564.   sqlite3_int64 n;

  181565. 

  181566.   UNUSED_PARAM(idxStr);

  181567.   UNUSED_PARAM(argc);

  181568.   jsonEachCursorReset(p);

  181569.   if( idxNum==0 ) return SQLITE_OK;

  181570.   z = (const char*)sqlite3_value_text(argv[0]);

  181571.   if( z==0 ) return SQLITE_OK;

  181572.   n = sqlite3_value_bytes(argv[0]);

  181573.   p->zJson = sqlite3_malloc64( n+1 );

  181574.   if( p->zJson==0 ) return SQLITE_NOMEM;

  181575.   memcpy(p->zJson, z, (size_t)n+1);

  181576.   if( jsonParse(&p->sParse, 0, p->zJson) ){

  181577.     int rc = SQLITE_NOMEM;

  181578.     if( p->sParse.oom==0 ){

  181579.       sqlite3_free(cur->pVtab->zErrMsg);

  181580.       cur->pVtab->zErrMsg = sqlite3_mprintf("malformed JSON");

  181581.       if( cur->pVtab->zErrMsg ) rc = SQLITE_ERROR;

  181582.     }

  181583.     jsonEachCursorReset(p);

  181584.     return rc;

  181585.   }else if( p->bRecursive && jsonParseFindParents(&p->sParse) ){

  181586.     jsonEachCursorReset(p);

  181587.     return SQLITE_NOMEM;

  181588.   }else{

  181589.     JsonNode *pNode = 0;

  181590.     if( idxNum==3 ){

  181591.       const char *zErr = 0;

  181592.       zRoot = (const char*)sqlite3_value_text(argv[1]);

  181593.       if( zRoot==0 ) return SQLITE_OK;

  181594.       n = sqlite3_value_bytes(argv[1]);

  181595.       p->zRoot = sqlite3_malloc64( n+1 );

  181596.       if( p->zRoot==0 ) return SQLITE_NOMEM;

  181597.       memcpy(p->zRoot, zRoot, (size_t)n+1);

  181598.       if( zRoot[0]!='$' ){

  181599.         zErr = zRoot;

  181600.       }else{

  181601.         pNode = jsonLookupStep(&p->sParse, 0, p->zRoot+1, 0, &zErr);

  181602.       }

  181603.       if( zErr ){

  181604.         sqlite3_free(cur->pVtab->zErrMsg);

  181605.         cur->pVtab->zErrMsg = jsonPathSyntaxError(zErr);

  181606.         jsonEachCursorReset(p);

  181607.         return cur->pVtab->zErrMsg ? SQLITE_ERROR : SQLITE_NOMEM;

  181608.       }else if( pNode==0 ){

  181609.         return SQLITE_OK;

  181610.       }

  181611.     }else{

  181612.       pNode = p->sParse.aNode;

  181613.     }

  181614.     p->iBegin = p->i = (int)(pNode - p->sParse.aNode);

  181615.     p->eType = pNode->eType;

  181616.     if( p->eType>=JSON_ARRAY ){

  181617.       pNode->u.iKey = 0;

  181618.       p->iEnd = p->i + pNode->n + 1;

  181619.       if( p->bRecursive ){

  181620.         p->eType = p->sParse.aNode[p->sParse.aUp[p->i]].eType;

  181621.         if( p->i>0 && (p->sParse.aNode[p->i-1].jnFlags & JNODE_LABEL)!=0 ){

  181622.           p->i--;

  181623.         }

  181624.       }else{

  181625.         p->i++;

  181626.       }

  181627.     }else{

  181628.       p->iEnd = p->i+1;

  181629.     }

  181630.   }

  181631.   return SQLITE_OK;

  181632. }

  181633. 

  181634. /* The methods of the json_each virtual table */

  181635. static sqlite3_module jsonEachModule = {

  181636.   0,                         /* iVersion */

  181637.   0,                         /* xCreate */

  181638.   jsonEachConnect,           /* xConnect */

  181639.   jsonEachBestIndex,         /* xBestIndex */

  181640.   jsonEachDisconnect,        /* xDisconnect */

  181641.   0,                         /* xDestroy */

  181642.   jsonEachOpenEach,          /* xOpen - open a cursor */

  181643.   jsonEachClose,             /* xClose - close a cursor */

  181644.   jsonEachFilter,            /* xFilter - configure scan constraints */

  181645.   jsonEachNext,              /* xNext - advance a cursor */

  181646.   jsonEachEof,               /* xEof - check for end of scan */

  181647.   jsonEachColumn,            /* xColumn - read data */

  181648.   jsonEachRowid,             /* xRowid - read data */

  181649.   0,                         /* xUpdate */

  181650.   0,                         /* xBegin */

  181651.   0,                         /* xSync */

  181652.   0,                         /* xCommit */

  181653.   0,                         /* xRollback */

  181654.   0,                         /* xFindMethod */

  181655.   0,                         /* xRename */

  181656.   0,                         /* xSavepoint */

  181657.   0,                         /* xRelease */

  181658.   0,                         /* xRollbackTo */

  181659.   0                          /* xShadowName */

  181660. };

  181661. 

  181662. /* The methods of the json_tree virtual table. */

  181663. static sqlite3_module jsonTreeModule = {

  181664.   0,                         /* iVersion */

  181665.   0,                         /* xCreate */

  181666.   jsonEachConnect,           /* xConnect */

  181667.   jsonEachBestIndex,         /* xBestIndex */

  181668.   jsonEachDisconnect,        /* xDisconnect */

  181669.   0,                         /* xDestroy */

  181670.   jsonEachOpenTree,          /* xOpen - open a cursor */

  181671.   jsonEachClose,             /* xClose - close a cursor */

  181672.   jsonEachFilter,            /* xFilter - configure scan constraints */

  181673.   jsonEachNext,              /* xNext - advance a cursor */

  181674.   jsonEachEof,               /* xEof - check for end of scan */

  181675.   jsonEachColumn,            /* xColumn - read data */

  181676.   jsonEachRowid,             /* xRowid - read data */

  181677.   0,                         /* xUpdate */

  181678.   0,                         /* xBegin */

  181679.   0,                         /* xSync */

  181680.   0,                         /* xCommit */

  181681.   0,                         /* xRollback */

  181682.   0,                         /* xFindMethod */

  181683.   0,                         /* xRename */

  181684.   0,                         /* xSavepoint */

  181685.   0,                         /* xRelease */

  181686.   0,                         /* xRollbackTo */

  181687.   0                          /* xShadowName */

  181688. };

  181689. #endif /* SQLITE_OMIT_VIRTUALTABLE */

  181690. 

  181691. /****************************************************************************

  181692. ** The following routines are the only publically visible identifiers in this

  181693. ** file.  Call the following routines in order to register the various SQL

  181694. ** functions and the virtual table implemented by this file.

  181695. ****************************************************************************/

  181696. 

  181697. SQLITE_PRIVATE int sqlite3Json1Init(sqlite3 *db){

  181698.   int rc = SQLITE_OK;

  181699.   unsigned int i;

  181700.   static const struct {

  181701.      const char *zName;

  181702.      int nArg;

  181703.      int flag;

  181704.      void (*xFunc)(sqlite3_context*,int,sqlite3_value**);

  181705.   } aFunc[] = {

  181706.     { "json",                 1, 0,   jsonRemoveFunc        },

  181707.     { "json_array",          -1, 0,   jsonArrayFunc         },

  181708.     { "json_array_length",    1, 0,   jsonArrayLengthFunc   },

  181709.     { "json_array_length",    2, 0,   jsonArrayLengthFunc   },

  181710.     { "json_extract",        -1, 0,   jsonExtractFunc       },

  181711.     { "json_insert",         -1, 0,   jsonSetFunc           },

  181712.     { "json_object",         -1, 0,   jsonObjectFunc        },

  181713.     { "json_patch",           2, 0,   jsonPatchFunc         },

  181714.     { "json_quote",           1, 0,   jsonQuoteFunc         },

  181715.     { "json_remove",         -1, 0,   jsonRemoveFunc        },

  181716.     { "json_replace",        -1, 0,   jsonReplaceFunc       },

  181717.     { "json_set",            -1, 1,   jsonSetFunc           },

  181718.     { "json_type",            1, 0,   jsonTypeFunc          },

  181719.     { "json_type",            2, 0,   jsonTypeFunc          },

  181720.     { "json_valid",           1, 0,   jsonValidFunc         },

  181721. 

  181722. #if SQLITE_DEBUG

  181723.     /* DEBUG and TESTING functions */

  181724.     { "json_parse",           1, 0,   jsonParseFunc         },

  181725.     { "json_test1",           1, 0,   jsonTest1Func         },

  181726. #endif

  181727.   };

  181728.   static const struct {

  181729.      const char *zName;

  181730.      int nArg;

  181731.      void (*xStep)(sqlite3_context*,int,sqlite3_value**);

  181732.      void (*xFinal)(sqlite3_context*);

  181733.      void (*xValue)(sqlite3_context*);

  181734.   } aAgg[] = {

  181735.     { "json_group_array",     1,

  181736.       jsonArrayStep,   jsonArrayFinal,  jsonArrayValue  },

  181737.     { "json_group_object",    2,

  181738.       jsonObjectStep,  jsonObjectFinal, jsonObjectValue },

  181739.   };

  181740. #ifndef SQLITE_OMIT_VIRTUALTABLE

  181741.   static const struct {

  181742.      const char *zName;

  181743.      sqlite3_module *pModule;

  181744.   } aMod[] = {

  181745.     { "json_each",            &jsonEachModule               },

  181746.     { "json_tree",            &jsonTreeModule               },

  181747.   };

  181748. #endif

  181749.   for(i=0; i<sizeof(aFunc)/sizeof(aFunc[0]) && rc==SQLITE_OK; i++){

  181750.     rc = sqlite3_create_function(db, aFunc[i].zName, aFunc[i].nArg,

  181751.                                  SQLITE_UTF8 | SQLITE_DETERMINISTIC, 

  181752.                                  (void*)&aFunc[i].flag,

  181753.                                  aFunc[i].xFunc, 0, 0);

  181754.   }

  181755. #ifndef SQLITE_OMIT_WINDOWFUNC

  181756.   for(i=0; i<sizeof(aAgg)/sizeof(aAgg[0]) && rc==SQLITE_OK; i++){

  181757.     rc = sqlite3_create_window_function(db, aAgg[i].zName, aAgg[i].nArg,

  181758.                                  SQLITE_UTF8 | SQLITE_DETERMINISTIC, 0,

  181759.                                  aAgg[i].xStep, aAgg[i].xFinal,

  181760.                                  aAgg[i].xValue, jsonGroupInverse, 0);

  181761.   }

  181762. #endif

  181763. #ifndef SQLITE_OMIT_VIRTUALTABLE

  181764.   for(i=0; i<sizeof(aMod)/sizeof(aMod[0]) && rc==SQLITE_OK; i++){

  181765.     rc = sqlite3_create_module(db, aMod[i].zName, aMod[i].pModule, 0);

  181766.   }

  181767. #endif

  181768.   return rc;

  181769. }

  181770. 

  181771. 

  181772. #ifndef SQLITE_CORE

  181773. #ifdef _WIN32

  181774. __declspec(dllexport)

  181775. #endif

  181776. SQLITE_API int sqlite3_json_init(

  181777.   sqlite3 *db, 

  181778.   char **pzErrMsg, 

  181779.   const sqlite3_api_routines *pApi

  181780. ){

  181781.   SQLITE_EXTENSION_INIT2(pApi);

  181782.   (void)pzErrMsg;  /* Unused parameter */

  181783.   return sqlite3Json1Init(db);

  181784. }

  181785. #endif

  181786. #endif /* !defined(SQLITE_CORE) || defined(SQLITE_ENABLE_JSON1) */

  181787. 

  181788. /************** End of json1.c ***********************************************/

  181789. /************** Begin file rtree.c *******************************************/

  181790. /*

  181791. ** 2001 September 15

  181792. **

  181793. ** The author disclaims copyright to this source code.  In place of

  181794. ** a legal notice, here is a blessing:

  181795. **

  181796. **    May you do good and not evil.

  181797. **    May you find forgiveness for yourself and forgive others.

  181798. **    May you share freely, never taking more than you give.

  181799. **

  181800. *************************************************************************

  181801. ** This file contains code for implementations of the r-tree and r*-tree

  181802. ** algorithms packaged as an SQLite virtual table module.

  181803. */

  181804. 

  181805. /*

  181806. ** Database Format of R-Tree Tables

  181807. ** --------------------------------

  181808. **

  181809. ** The data structure for a single virtual r-tree table is stored in three 

  181810. ** native SQLite tables declared as follows. In each case, the '%' character

  181811. ** in the table name is replaced with the user-supplied name of the r-tree

  181812. ** table.

  181813. **

  181814. **   CREATE TABLE %_node(nodeno INTEGER PRIMARY KEY, data BLOB)

  181815. **   CREATE TABLE %_parent(nodeno INTEGER PRIMARY KEY, parentnode INTEGER)

  181816. **   CREATE TABLE %_rowid(rowid INTEGER PRIMARY KEY, nodeno INTEGER, ...)

  181817. **

  181818. ** The data for each node of the r-tree structure is stored in the %_node

  181819. ** table. For each node that is not the root node of the r-tree, there is

  181820. ** an entry in the %_parent table associating the node with its parent.

  181821. ** And for each row of data in the table, there is an entry in the %_rowid

  181822. ** table that maps from the entries rowid to the id of the node that it

  181823. ** is stored on.  If the r-tree contains auxiliary columns, those are stored

  181824. ** on the end of the %_rowid table.

  181825. **

  181826. ** The root node of an r-tree always exists, even if the r-tree table is

  181827. ** empty. The nodeno of the root node is always 1. All other nodes in the

  181828. ** table must be the same size as the root node. The content of each node

  181829. ** is formatted as follows:

  181830. **

  181831. **   1. If the node is the root node (node 1), then the first 2 bytes

  181832. **      of the node contain the tree depth as a big-endian integer.

  181833. **      For non-root nodes, the first 2 bytes are left unused.

  181834. **

  181835. **   2. The next 2 bytes contain the number of entries currently 

  181836. **      stored in the node.

  181837. **

  181838. **   3. The remainder of the node contains the node entries. Each entry

  181839. **      consists of a single 8-byte integer followed by an even number

  181840. **      of 4-byte coordinates. For leaf nodes the integer is the rowid

  181841. **      of a record. For internal nodes it is the node number of a

  181842. **      child page.

  181843. */

  181844. 

  181845. #if !defined(SQLITE_CORE) \

  181846.   || (defined(SQLITE_ENABLE_RTREE) && !defined(SQLITE_OMIT_VIRTUALTABLE))

  181847. 

  181848. #ifndef SQLITE_CORE

  181849. /*   #include "sqlite3ext.h" */

  181850.   SQLITE_EXTENSION_INIT1

  181851. #else

  181852. /*   #include "sqlite3.h" */

  181853. #endif

  181854. 

  181855. #ifndef SQLITE_AMALGAMATION

  181856. #include "sqlite3rtree.h"

  181857. typedef sqlite3_int64 i64;

  181858. typedef sqlite3_uint64 u64;

  181859. typedef unsigned char u8;

  181860. typedef unsigned short u16;

  181861. typedef unsigned int u32;

  181862. #if !defined(NDEBUG) && !defined(SQLITE_DEBUG)

  181863. # define NDEBUG 1

  181864. #endif

  181865. #if defined(NDEBUG) && defined(SQLITE_DEBUG)

  181866. # undef NDEBUG

  181867. #endif

  181868. #endif

  181869. 

  181870. /* #include <string.h> */

  181871. /* #include <stdio.h> */

  181872. /* #include <assert.h> */

  181873. 

  181874. /*  The following macro is used to suppress compiler warnings.

  181875. */

  181876. #ifndef UNUSED_PARAMETER

  181877. # define UNUSED_PARAMETER(x) (void)(x)

  181878. #endif

  181879. 

  181880. typedef struct Rtree Rtree;

  181881. typedef struct RtreeCursor RtreeCursor;

  181882. typedef struct RtreeNode RtreeNode;

  181883. typedef struct RtreeCell RtreeCell;

  181884. typedef struct RtreeConstraint RtreeConstraint;

  181885. typedef struct RtreeMatchArg RtreeMatchArg;

  181886. typedef struct RtreeGeomCallback RtreeGeomCallback;

  181887. typedef union RtreeCoord RtreeCoord;

  181888. typedef struct RtreeSearchPoint RtreeSearchPoint;

  181889. 

  181890. /* The rtree may have between 1 and RTREE_MAX_DIMENSIONS dimensions. */

  181891. #define RTREE_MAX_DIMENSIONS 5

  181892. 

  181893. /* Maximum number of auxiliary columns */

  181894. #define RTREE_MAX_AUX_COLUMN 100

  181895. 

  181896. /* Size of hash table Rtree.aHash. This hash table is not expected to

  181897. ** ever contain very many entries, so a fixed number of buckets is 

  181898. ** used.

  181899. */

  181900. #define HASHSIZE 97

  181901. 

  181902. /* The xBestIndex method of this virtual table requires an estimate of

  181903. ** the number of rows in the virtual table to calculate the costs of

  181904. ** various strategies. If possible, this estimate is loaded from the

  181905. ** sqlite_stat1 table (with RTREE_MIN_ROWEST as a hard-coded minimum).

  181906. ** Otherwise, if no sqlite_stat1 entry is available, use 

  181907. ** RTREE_DEFAULT_ROWEST.

  181908. */

  181909. #define RTREE_DEFAULT_ROWEST 1048576

  181910. #define RTREE_MIN_ROWEST         100

  181911. 

  181912. /* 

  181913. ** An rtree virtual-table object.

  181914. */

  181915. struct Rtree {

  181916.   sqlite3_vtab base;          /* Base class.  Must be first */

  181917.   sqlite3 *db;                /* Host database connection */

  181918.   int iNodeSize;              /* Size in bytes of each node in the node table */

  181919.   u8 nDim;                    /* Number of dimensions */

  181920.   u8 nDim2;                   /* Twice the number of dimensions */

  181921.   u8 eCoordType;              /* RTREE_COORD_REAL32 or RTREE_COORD_INT32 */

  181922.   u8 nBytesPerCell;           /* Bytes consumed per cell */

  181923.   u8 inWrTrans;               /* True if inside write transaction */

  181924.   u8 nAux;                    /* # of auxiliary columns in %_rowid */

  181925.   u8 nAuxNotNull;             /* Number of initial not-null aux columns */

  181926. #ifdef SQLITE_DEBUG

  181927.   u8 bCorrupt;                /* Shadow table corruption detected */

  181928. #endif

  181929.   int iDepth;                 /* Current depth of the r-tree structure */

  181930.   char *zDb;                  /* Name of database containing r-tree table */

  181931.   char *zName;                /* Name of r-tree table */ 

  181932.   u32 nBusy;                  /* Current number of users of this structure */

  181933.   i64 nRowEst;                /* Estimated number of rows in this table */

  181934.   u32 nCursor;                /* Number of open cursors */

  181935.   u32 nNodeRef;               /* Number RtreeNodes with positive nRef */

  181936.   char *zReadAuxSql;          /* SQL for statement to read aux data */

  181937. 

  181938.   /* List of nodes removed during a CondenseTree operation. List is

  181939.   ** linked together via the pointer normally used for hash chains -

  181940.   ** RtreeNode.pNext. RtreeNode.iNode stores the depth of the sub-tree 

  181941.   ** headed by the node (leaf nodes have RtreeNode.iNode==0).

  181942.   */

  181943.   RtreeNode *pDeleted;

  181944.   int iReinsertHeight;        /* Height of sub-trees Reinsert() has run on */

  181945. 

  181946.   /* Blob I/O on xxx_node */

  181947.   sqlite3_blob *pNodeBlob;

  181948. 

  181949.   /* Statements to read/write/delete a record from xxx_node */

  181950.   sqlite3_stmt *pWriteNode;

  181951.   sqlite3_stmt *pDeleteNode;

  181952. 

  181953.   /* Statements to read/write/delete a record from xxx_rowid */

  181954.   sqlite3_stmt *pReadRowid;

  181955.   sqlite3_stmt *pWriteRowid;

  181956.   sqlite3_stmt *pDeleteRowid;

  181957. 

  181958.   /* Statements to read/write/delete a record from xxx_parent */

  181959.   sqlite3_stmt *pReadParent;

  181960.   sqlite3_stmt *pWriteParent;

  181961.   sqlite3_stmt *pDeleteParent;

  181962. 

  181963.   /* Statement for writing to the "aux:" fields, if there are any */

  181964.   sqlite3_stmt *pWriteAux;

  181965. 

  181966.   RtreeNode *aHash[HASHSIZE]; /* Hash table of in-memory nodes. */ 

  181967. };

  181968. 

  181969. /* Possible values for Rtree.eCoordType: */

  181970. #define RTREE_COORD_REAL32 0

  181971. #define RTREE_COORD_INT32  1

  181972. 

  181973. /*

  181974. ** If SQLITE_RTREE_INT_ONLY is defined, then this virtual table will

  181975. ** only deal with integer coordinates.  No floating point operations

  181976. ** will be done.

  181977. */

  181978. #ifdef SQLITE_RTREE_INT_ONLY

  181979.   typedef sqlite3_int64 RtreeDValue;       /* High accuracy coordinate */

  181980.   typedef int RtreeValue;                  /* Low accuracy coordinate */

  181981. # define RTREE_ZERO 0

  181982. #else

  181983.   typedef double RtreeDValue;              /* High accuracy coordinate */

  181984.   typedef float RtreeValue;                /* Low accuracy coordinate */

  181985. # define RTREE_ZERO 0.0

  181986. #endif

  181987. 

  181988. /*

  181989. ** Set the Rtree.bCorrupt flag

  181990. */

  181991. #ifdef SQLITE_DEBUG

  181992. # define RTREE_IS_CORRUPT(X) ((X)->bCorrupt = 1)

  181993. #else

  181994. # define RTREE_IS_CORRUPT(X)

  181995. #endif

  181996. 

  181997. /*

  181998. ** When doing a search of an r-tree, instances of the following structure

  181999. ** record intermediate results from the tree walk.

  182000. **

  182001. ** The id is always a node-id.  For iLevel>=1 the id is the node-id of

  182002. ** the node that the RtreeSearchPoint represents.  When iLevel==0, however,

  182003. ** the id is of the parent node and the cell that RtreeSearchPoint

  182004. ** represents is the iCell-th entry in the parent node.

  182005. */

  182006. struct RtreeSearchPoint {

  182007.   RtreeDValue rScore;    /* The score for this node.  Smallest goes first. */

  182008.   sqlite3_int64 id;      /* Node ID */

  182009.   u8 iLevel;             /* 0=entries.  1=leaf node.  2+ for higher */

  182010.   u8 eWithin;            /* PARTLY_WITHIN or FULLY_WITHIN */

  182011.   u8 iCell;              /* Cell index within the node */

  182012. };

  182013. 

  182014. /*

  182015. ** The minimum number of cells allowed for a node is a third of the 

  182016. ** maximum. In Gutman's notation:

  182017. **

  182018. **     m = M/3

  182019. **

  182020. ** If an R*-tree "Reinsert" operation is required, the same number of

  182021. ** cells are removed from the overfull node and reinserted into the tree.

  182022. */

  182023. #define RTREE_MINCELLS(p) ((((p)->iNodeSize-4)/(p)->nBytesPerCell)/3)

  182024. #define RTREE_REINSERT(p) RTREE_MINCELLS(p)

  182025. #define RTREE_MAXCELLS 51

  182026. 

  182027. /*

  182028. ** The smallest possible node-size is (512-64)==448 bytes. And the largest

  182029. ** supported cell size is 48 bytes (8 byte rowid + ten 4 byte coordinates).

  182030. ** Therefore all non-root nodes must contain at least 3 entries. Since 

  182031. ** 3^40 is greater than 2^64, an r-tree structure always has a depth of

  182032. ** 40 or less.

  182033. */

  182034. #define RTREE_MAX_DEPTH 40

  182035. 

  182036. 

  182037. /*

  182038. ** Number of entries in the cursor RtreeNode cache.  The first entry is

  182039. ** used to cache the RtreeNode for RtreeCursor.sPoint.  The remaining

  182040. ** entries cache the RtreeNode for the first elements of the priority queue.

  182041. */

  182042. #define RTREE_CACHE_SZ  5

  182043. 

  182044. /* 

  182045. ** An rtree cursor object.

  182046. */

  182047. struct RtreeCursor {

  182048.   sqlite3_vtab_cursor base;         /* Base class.  Must be first */

  182049.   u8 atEOF;                         /* True if at end of search */

  182050.   u8 bPoint;                        /* True if sPoint is valid */

  182051.   u8 bAuxValid;                     /* True if pReadAux is valid */

  182052.   int iStrategy;                    /* Copy of idxNum search parameter */

  182053.   int nConstraint;                  /* Number of entries in aConstraint */

  182054.   RtreeConstraint *aConstraint;     /* Search constraints. */

  182055.   int nPointAlloc;                  /* Number of slots allocated for aPoint[] */

  182056.   int nPoint;                       /* Number of slots used in aPoint[] */

  182057.   int mxLevel;                      /* iLevel value for root of the tree */

  182058.   RtreeSearchPoint *aPoint;         /* Priority queue for search points */

  182059.   sqlite3_stmt *pReadAux;           /* Statement to read aux-data */

  182060.   RtreeSearchPoint sPoint;          /* Cached next search point */

  182061.   RtreeNode *aNode[RTREE_CACHE_SZ]; /* Rtree node cache */

  182062.   u32 anQueue[RTREE_MAX_DEPTH+1];   /* Number of queued entries by iLevel */

  182063. };

  182064. 

  182065. /* Return the Rtree of a RtreeCursor */

  182066. #define RTREE_OF_CURSOR(X)   ((Rtree*)((X)->base.pVtab))

  182067. 

  182068. /*

  182069. ** A coordinate can be either a floating point number or a integer.  All

  182070. ** coordinates within a single R-Tree are always of the same time.

  182071. */

  182072. union RtreeCoord {

  182073.   RtreeValue f;      /* Floating point value */

  182074.   int i;             /* Integer value */

  182075.   u32 u;             /* Unsigned for byte-order conversions */

  182076. };

  182077. 

  182078. /*

  182079. ** The argument is an RtreeCoord. Return the value stored within the RtreeCoord

  182080. ** formatted as a RtreeDValue (double or int64). This macro assumes that local

  182081. ** variable pRtree points to the Rtree structure associated with the

  182082. ** RtreeCoord.

  182083. */

  182084. #ifdef SQLITE_RTREE_INT_ONLY

  182085. # define DCOORD(coord) ((RtreeDValue)coord.i)

  182086. #else

  182087. # define DCOORD(coord) (                           \

  182088.     (pRtree->eCoordType==RTREE_COORD_REAL32) ?      \

  182089.       ((double)coord.f) :                           \

  182090.       ((double)coord.i)                             \

  182091.   )

  182092. #endif

  182093. 

  182094. /*

  182095. ** A search constraint.

  182096. */

  182097. struct RtreeConstraint {

  182098.   int iCoord;                     /* Index of constrained coordinate */

  182099.   int op;                         /* Constraining operation */

  182100.   union {

  182101.     RtreeDValue rValue;             /* Constraint value. */

  182102.     int (*xGeom)(sqlite3_rtree_geometry*,int,RtreeDValue*,int*);

  182103.     int (*xQueryFunc)(sqlite3_rtree_query_info*);

  182104.   } u;

  182105.   sqlite3_rtree_query_info *pInfo;  /* xGeom and xQueryFunc argument */

  182106. };

  182107. 

  182108. /* Possible values for RtreeConstraint.op */

  182109. #define RTREE_EQ    0x41  /* A */

  182110. #define RTREE_LE    0x42  /* B */

  182111. #define RTREE_LT    0x43  /* C */

  182112. #define RTREE_GE    0x44  /* D */

  182113. #define RTREE_GT    0x45  /* E */

  182114. #define RTREE_MATCH 0x46  /* F: Old-style sqlite3_rtree_geometry_callback() */

  182115. #define RTREE_QUERY 0x47  /* G: New-style sqlite3_rtree_query_callback() */

  182116. 

  182117. 

  182118. /* 

  182119. ** An rtree structure node.

  182120. */

  182121. struct RtreeNode {

  182122.   RtreeNode *pParent;         /* Parent node */

  182123.   i64 iNode;                  /* The node number */

  182124.   int nRef;                   /* Number of references to this node */

  182125.   int isDirty;                /* True if the node needs to be written to disk */

  182126.   u8 *zData;                  /* Content of the node, as should be on disk */

  182127.   RtreeNode *pNext;           /* Next node in this hash collision chain */

  182128. };

  182129. 

  182130. /* Return the number of cells in a node  */

  182131. #define NCELL(pNode) readInt16(&(pNode)->zData[2])

  182132. 

  182133. /* 

  182134. ** A single cell from a node, deserialized

  182135. */

  182136. struct RtreeCell {

  182137.   i64 iRowid;                                 /* Node or entry ID */

  182138.   RtreeCoord aCoord[RTREE_MAX_DIMENSIONS*2];  /* Bounding box coordinates */

  182139. };

  182140. 

  182141. 

  182142. /*

  182143. ** This object becomes the sqlite3_user_data() for the SQL functions

  182144. ** that are created by sqlite3_rtree_geometry_callback() and

  182145. ** sqlite3_rtree_query_callback() and which appear on the right of MATCH

  182146. ** operators in order to constrain a search.

  182147. **

  182148. ** xGeom and xQueryFunc are the callback functions.  Exactly one of 

  182149. ** xGeom and xQueryFunc fields is non-NULL, depending on whether the

  182150. ** SQL function was created using sqlite3_rtree_geometry_callback() or

  182151. ** sqlite3_rtree_query_callback().

  182152. ** 

  182153. ** This object is deleted automatically by the destructor mechanism in

  182154. ** sqlite3_create_function_v2().

  182155. */

  182156. struct RtreeGeomCallback {

  182157.   int (*xGeom)(sqlite3_rtree_geometry*, int, RtreeDValue*, int*);

  182158.   int (*xQueryFunc)(sqlite3_rtree_query_info*);

  182159.   void (*xDestructor)(void*);

  182160.   void *pContext;

  182161. };

  182162. 

  182163. /*

  182164. ** An instance of this structure (in the form of a BLOB) is returned by

  182165. ** the SQL functions that sqlite3_rtree_geometry_callback() and

  182166. ** sqlite3_rtree_query_callback() create, and is read as the right-hand

  182167. ** operand to the MATCH operator of an R-Tree.

  182168. */

  182169. struct RtreeMatchArg {

  182170.   u32 iSize;                  /* Size of this object */

  182171.   RtreeGeomCallback cb;       /* Info about the callback functions */

  182172.   int nParam;                 /* Number of parameters to the SQL function */

  182173.   sqlite3_value **apSqlParam; /* Original SQL parameter values */

  182174.   RtreeDValue aParam[1];      /* Values for parameters to the SQL function */

  182175. };

  182176. 

  182177. #ifndef MAX

  182178. # define MAX(x,y) ((x) < (y) ? (y) : (x))

  182179. #endif

  182180. #ifndef MIN

  182181. # define MIN(x,y) ((x) > (y) ? (y) : (x))

  182182. #endif

  182183. 

  182184. /* What version of GCC is being used.  0 means GCC is not being used .

  182185. ** Note that the GCC_VERSION macro will also be set correctly when using

  182186. ** clang, since clang works hard to be gcc compatible.  So the gcc

  182187. ** optimizations will also work when compiling with clang.

  182188. */

  182189. #ifndef GCC_VERSION

  182190. #if defined(__GNUC__) && !defined(SQLITE_DISABLE_INTRINSIC)

  182191. # define GCC_VERSION (__GNUC__*1000000+__GNUC_MINOR__*1000+__GNUC_PATCHLEVEL__)

  182192. #else

  182193. # define GCC_VERSION 0

  182194. #endif

  182195. #endif

  182196. 

  182197. /* The testcase() macro should already be defined in the amalgamation.  If

  182198. ** it is not, make it a no-op.

  182199. */

  182200. #ifndef SQLITE_AMALGAMATION

  182201. # define testcase(X)

  182202. #endif

  182203. 

  182204. /*

  182205. ** Macros to determine whether the machine is big or little endian,

  182206. ** and whether or not that determination is run-time or compile-time.

  182207. **

  182208. ** For best performance, an attempt is made to guess at the byte-order

  182209. ** using C-preprocessor macros.  If that is unsuccessful, or if

  182210. ** -DSQLITE_RUNTIME_BYTEORDER=1 is set, then byte-order is determined

  182211. ** at run-time.

  182212. */

  182213. #ifndef SQLITE_BYTEORDER

  182214. #if defined(i386)     || defined(__i386__)   || defined(_M_IX86) ||    \

  182215.     defined(__x86_64) || defined(__x86_64__) || defined(_M_X64)  ||    \

  182216.     defined(_M_AMD64) || defined(_M_ARM)     || defined(__x86)   ||    \

  182217.     defined(__arm__)

  182218. # define SQLITE_BYTEORDER    1234

  182219. #elif defined(sparc)    || defined(__ppc__)

  182220. # define SQLITE_BYTEORDER    4321

  182221. #else

  182222. # define SQLITE_BYTEORDER    0     /* 0 means "unknown at compile-time" */

  182223. #endif

  182224. #endif

  182225. 

  182226. 

  182227. /* What version of MSVC is being used.  0 means MSVC is not being used */

  182228. #ifndef MSVC_VERSION

  182229. #if defined(_MSC_VER) && !defined(SQLITE_DISABLE_INTRINSIC)

  182230. # define MSVC_VERSION _MSC_VER

  182231. #else

  182232. # define MSVC_VERSION 0

  182233. #endif

  182234. #endif

  182235. 

  182236. /*

  182237. ** Functions to deserialize a 16 bit integer, 32 bit real number and

  182238. ** 64 bit integer. The deserialized value is returned.

  182239. */

  182240. static int readInt16(u8 *p){

  182241.   return (p[0]<<8) + p[1];

  182242. }

  182243. static void readCoord(u8 *p, RtreeCoord *pCoord){

  182244.   assert( ((((char*)p) - (char*)0)&3)==0 );  /* p is always 4-byte aligned */

  182245. #if SQLITE_BYTEORDER==1234 && MSVC_VERSION>=1300

  182246.   pCoord->u = _byteswap_ulong(*(u32*)p);

  182247. #elif SQLITE_BYTEORDER==1234 && GCC_VERSION>=4003000

  182248.   pCoord->u = __builtin_bswap32(*(u32*)p);

  182249. #elif SQLITE_BYTEORDER==4321

  182250.   pCoord->u = *(u32*)p;

  182251. #else

  182252.   pCoord->u = (

  182253.     (((u32)p[0]) << 24) + 

  182254.     (((u32)p[1]) << 16) + 

  182255.     (((u32)p[2]) <<  8) + 

  182256.     (((u32)p[3]) <<  0)

  182257.   );

  182258. #endif

  182259. }

  182260. static i64 readInt64(u8 *p){

  182261. #if SQLITE_BYTEORDER==1234 && MSVC_VERSION>=1300

  182262.   u64 x;

  182263.   memcpy(&x, p, 8);

  182264.   return (i64)_byteswap_uint64(x);

  182265. #elif SQLITE_BYTEORDER==1234 && GCC_VERSION>=4003000

  182266.   u64 x;

  182267.   memcpy(&x, p, 8);

  182268.   return (i64)__builtin_bswap64(x);

  182269. #elif SQLITE_BYTEORDER==4321

  182270.   i64 x;

  182271.   memcpy(&x, p, 8);

  182272.   return x;

  182273. #else

  182274.   return (i64)(

  182275.     (((u64)p[0]) << 56) + 

  182276.     (((u64)p[1]) << 48) + 

  182277.     (((u64)p[2]) << 40) + 

  182278.     (((u64)p[3]) << 32) + 

  182279.     (((u64)p[4]) << 24) + 

  182280.     (((u64)p[5]) << 16) + 

  182281.     (((u64)p[6]) <<  8) + 

  182282.     (((u64)p[7]) <<  0)

  182283.   );

  182284. #endif

  182285. }

  182286. 

  182287. /*

  182288. ** Functions to serialize a 16 bit integer, 32 bit real number and

  182289. ** 64 bit integer. The value returned is the number of bytes written

  182290. ** to the argument buffer (always 2, 4 and 8 respectively).

  182291. */

  182292. static void writeInt16(u8 *p, int i){

  182293.   p[0] = (i>> 8)&0xFF;

  182294.   p[1] = (i>> 0)&0xFF;

  182295. }

  182296. static int writeCoord(u8 *p, RtreeCoord *pCoord){

  182297.   u32 i;

  182298.   assert( ((((char*)p) - (char*)0)&3)==0 );  /* p is always 4-byte aligned */

  182299.   assert( sizeof(RtreeCoord)==4 );

  182300.   assert( sizeof(u32)==4 );

  182301. #if SQLITE_BYTEORDER==1234 && GCC_VERSION>=4003000

  182302.   i = __builtin_bswap32(pCoord->u);

  182303.   memcpy(p, &i, 4);

  182304. #elif SQLITE_BYTEORDER==1234 && MSVC_VERSION>=1300

  182305.   i = _byteswap_ulong(pCoord->u);

  182306.   memcpy(p, &i, 4);

  182307. #elif SQLITE_BYTEORDER==4321

  182308.   i = pCoord->u;

  182309.   memcpy(p, &i, 4);

  182310. #else

  182311.   i = pCoord->u;

  182312.   p[0] = (i>>24)&0xFF;

  182313.   p[1] = (i>>16)&0xFF;

  182314.   p[2] = (i>> 8)&0xFF;

  182315.   p[3] = (i>> 0)&0xFF;

  182316. #endif

  182317.   return 4;

  182318. }

  182319. static int writeInt64(u8 *p, i64 i){

  182320. #if SQLITE_BYTEORDER==1234 && GCC_VERSION>=4003000

  182321.   i = (i64)__builtin_bswap64((u64)i);

  182322.   memcpy(p, &i, 8);

  182323. #elif SQLITE_BYTEORDER==1234 && MSVC_VERSION>=1300

  182324.   i = (i64)_byteswap_uint64((u64)i);

  182325.   memcpy(p, &i, 8);

  182326. #elif SQLITE_BYTEORDER==4321

  182327.   memcpy(p, &i, 8);

  182328. #else

  182329.   p[0] = (i>>56)&0xFF;

  182330.   p[1] = (i>>48)&0xFF;

  182331.   p[2] = (i>>40)&0xFF;

  182332.   p[3] = (i>>32)&0xFF;

  182333.   p[4] = (i>>24)&0xFF;

  182334.   p[5] = (i>>16)&0xFF;

  182335.   p[6] = (i>> 8)&0xFF;

  182336.   p[7] = (i>> 0)&0xFF;

  182337. #endif

  182338.   return 8;

  182339. }

  182340. 

  182341. /*

  182342. ** Increment the reference count of node p.

  182343. */

  182344. static void nodeReference(RtreeNode *p){

  182345.   if( p ){

  182346.     assert( p->nRef>0 );

  182347.     p->nRef++;

  182348.   }

  182349. }

  182350. 

  182351. /*

  182352. ** Clear the content of node p (set all bytes to 0x00).

  182353. */

  182354. static void nodeZero(Rtree *pRtree, RtreeNode *p){

  182355.   memset(&p->zData[2], 0, pRtree->iNodeSize-2);

  182356.   p->isDirty = 1;

  182357. }

  182358. 

  182359. /*

  182360. ** Given a node number iNode, return the corresponding key to use

  182361. ** in the Rtree.aHash table.

  182362. */

  182363. static unsigned int nodeHash(i64 iNode){

  182364.   return ((unsigned)iNode) % HASHSIZE;

  182365. }

  182366. 

  182367. /*

  182368. ** Search the node hash table for node iNode. If found, return a pointer

  182369. ** to it. Otherwise, return 0.

  182370. */

  182371. static RtreeNode *nodeHashLookup(Rtree *pRtree, i64 iNode){

  182372.   RtreeNode *p;

  182373.   for(p=pRtree->aHash[nodeHash(iNode)]; p && p->iNode!=iNode; p=p->pNext);

  182374.   return p;

  182375. }

  182376. 

  182377. /*

  182378. ** Add node pNode to the node hash table.

  182379. */

  182380. static void nodeHashInsert(Rtree *pRtree, RtreeNode *pNode){

  182381.   int iHash;

  182382.   assert( pNode->pNext==0 );

  182383.   iHash = nodeHash(pNode->iNode);

  182384.   pNode->pNext = pRtree->aHash[iHash];

  182385.   pRtree->aHash[iHash] = pNode;

  182386. }

  182387. 

  182388. /*

  182389. ** Remove node pNode from the node hash table.

  182390. */

  182391. static void nodeHashDelete(Rtree *pRtree, RtreeNode *pNode){

  182392.   RtreeNode **pp;

  182393.   if( pNode->iNode!=0 ){

  182394.     pp = &pRtree->aHash[nodeHash(pNode->iNode)];

  182395.     for( ; (*pp)!=pNode; pp = &(*pp)->pNext){ assert(*pp); }

  182396.     *pp = pNode->pNext;

  182397.     pNode->pNext = 0;

  182398.   }

  182399. }

  182400. 

  182401. /*

  182402. ** Allocate and return new r-tree node. Initially, (RtreeNode.iNode==0),

  182403. ** indicating that node has not yet been assigned a node number. It is

  182404. ** assigned a node number when nodeWrite() is called to write the

  182405. ** node contents out to the database.

  182406. */

  182407. static RtreeNode *nodeNew(Rtree *pRtree, RtreeNode *pParent){

  182408.   RtreeNode *pNode;

  182409.   pNode = (RtreeNode *)sqlite3_malloc64(sizeof(RtreeNode) + pRtree->iNodeSize);

  182410.   if( pNode ){

  182411.     memset(pNode, 0, sizeof(RtreeNode) + pRtree->iNodeSize);

  182412.     pNode->zData = (u8 *)&pNode[1];

  182413.     pNode->nRef = 1;

  182414.     pRtree->nNodeRef++;

  182415.     pNode->pParent = pParent;

  182416.     pNode->isDirty = 1;

  182417.     nodeReference(pParent);

  182418.   }

  182419.   return pNode;

  182420. }

  182421. 

  182422. /*

  182423. ** Clear the Rtree.pNodeBlob object

  182424. */

  182425. static void nodeBlobReset(Rtree *pRtree){

  182426.   if( pRtree->pNodeBlob && pRtree->inWrTrans==0 && pRtree->nCursor==0 ){

  182427.     sqlite3_blob *pBlob = pRtree->pNodeBlob;

  182428.     pRtree->pNodeBlob = 0;

  182429.     sqlite3_blob_close(pBlob);

  182430.   }

  182431. }

  182432. 

  182433. /*

  182434. ** Check to see if pNode is the same as pParent or any of the parents

  182435. ** of pParent.

  182436. */

  182437. static int nodeInParentChain(const RtreeNode *pNode, const RtreeNode *pParent){

  182438.   do{

  182439.     if( pNode==pParent ) return 1;

  182440.     pParent = pParent->pParent;

  182441.   }while( pParent );

  182442.   return 0;

  182443. }

  182444. 

  182445. /*

  182446. ** Obtain a reference to an r-tree node.

  182447. */

  182448. static int nodeAcquire(

  182449.   Rtree *pRtree,             /* R-tree structure */

  182450.   i64 iNode,                 /* Node number to load */

  182451.   RtreeNode *pParent,        /* Either the parent node or NULL */

  182452.   RtreeNode **ppNode         /* OUT: Acquired node */

  182453. ){

  182454.   int rc = SQLITE_OK;

  182455.   RtreeNode *pNode = 0;

  182456. 

  182457.   /* Check if the requested node is already in the hash table. If so,

  182458.   ** increase its reference count and return it.

  182459.   */

  182460.   if( (pNode = nodeHashLookup(pRtree, iNode))!=0 ){

  182461.     assert( !pParent || !pNode->pParent || pNode->pParent==pParent );

  182462.     if( pParent && !pNode->pParent ){

  182463.       if( nodeInParentChain(pNode, pParent) ){

  182464.         RTREE_IS_CORRUPT(pRtree);

  182465.         return SQLITE_CORRUPT_VTAB;

  182466.       }

  182467.       pParent->nRef++;

  182468.       pNode->pParent = pParent;

  182469.     }

  182470.     pNode->nRef++;

  182471.     *ppNode = pNode;

  182472.     return SQLITE_OK;

  182473.   }

  182474. 

  182475.   if( pRtree->pNodeBlob ){

  182476.     sqlite3_blob *pBlob = pRtree->pNodeBlob;

  182477.     pRtree->pNodeBlob = 0;

  182478.     rc = sqlite3_blob_reopen(pBlob, iNode);

  182479.     pRtree->pNodeBlob = pBlob;

  182480.     if( rc ){

  182481.       nodeBlobReset(pRtree);

  182482.       if( rc==SQLITE_NOMEM ) return SQLITE_NOMEM;

  182483.     }

  182484.   }

  182485.   if( pRtree->pNodeBlob==0 ){

  182486.     char *zTab = sqlite3_mprintf("%s_node", pRtree->zName);

  182487.     if( zTab==0 ) return SQLITE_NOMEM;

  182488.     rc = sqlite3_blob_open(pRtree->db, pRtree->zDb, zTab, "data", iNode, 0,

  182489.                            &pRtree->pNodeBlob);

  182490.     sqlite3_free(zTab);

  182491.   }

  182492.   if( rc ){

  182493.     nodeBlobReset(pRtree);

  182494.     *ppNode = 0;

  182495.     /* If unable to open an sqlite3_blob on the desired row, that can only

  182496.     ** be because the shadow tables hold erroneous data. */

  182497.     if( rc==SQLITE_ERROR ){

  182498.       rc = SQLITE_CORRUPT_VTAB;

  182499.       RTREE_IS_CORRUPT(pRtree);

  182500.     }

  182501.   }else if( pRtree->iNodeSize==sqlite3_blob_bytes(pRtree->pNodeBlob) ){

  182502.     pNode = (RtreeNode *)sqlite3_malloc64(sizeof(RtreeNode)+pRtree->iNodeSize);

  182503.     if( !pNode ){

  182504.       rc = SQLITE_NOMEM;

  182505.     }else{

  182506.       pNode->pParent = pParent;

  182507.       pNode->zData = (u8 *)&pNode[1];

  182508.       pNode->nRef = 1;

  182509.       pRtree->nNodeRef++;

  182510.       pNode->iNode = iNode;

  182511.       pNode->isDirty = 0;

  182512.       pNode->pNext = 0;

  182513.       rc = sqlite3_blob_read(pRtree->pNodeBlob, pNode->zData,

  182514.                              pRtree->iNodeSize, 0);

  182515.     }

  182516.   }

  182517. 

  182518.   /* If the root node was just loaded, set pRtree->iDepth to the height

  182519.   ** of the r-tree structure. A height of zero means all data is stored on

  182520.   ** the root node. A height of one means the children of the root node

  182521.   ** are the leaves, and so on. If the depth as specified on the root node

  182522.   ** is greater than RTREE_MAX_DEPTH, the r-tree structure must be corrupt.

  182523.   */

  182524.   if( pNode && iNode==1 ){

  182525.     pRtree->iDepth = readInt16(pNode->zData);

  182526.     if( pRtree->iDepth>RTREE_MAX_DEPTH ){

  182527.       rc = SQLITE_CORRUPT_VTAB;

  182528.       RTREE_IS_CORRUPT(pRtree);

  182529.     }

  182530.   }

  182531. 

  182532.   /* If no error has occurred so far, check if the "number of entries"

  182533.   ** field on the node is too large. If so, set the return code to 

  182534.   ** SQLITE_CORRUPT_VTAB.

  182535.   */

  182536.   if( pNode && rc==SQLITE_OK ){

  182537.     if( NCELL(pNode)>((pRtree->iNodeSize-4)/pRtree->nBytesPerCell) ){

  182538.       rc = SQLITE_CORRUPT_VTAB;

  182539.       RTREE_IS_CORRUPT(pRtree);

  182540.     }

  182541.   }

  182542. 

  182543.   if( rc==SQLITE_OK ){

  182544.     if( pNode!=0 ){

  182545.       nodeReference(pParent);

  182546.       nodeHashInsert(pRtree, pNode);

  182547.     }else{

  182548.       rc = SQLITE_CORRUPT_VTAB;

  182549.       RTREE_IS_CORRUPT(pRtree);

  182550.     }

  182551.     *ppNode = pNode;

  182552.   }else{

  182553.     if( pNode ){

  182554.       pRtree->nNodeRef--;

  182555.       sqlite3_free(pNode);

  182556.     }

  182557.     *ppNode = 0;

  182558.   }

  182559. 

  182560.   return rc;

  182561. }

  182562. 

  182563. /*

  182564. ** Overwrite cell iCell of node pNode with the contents of pCell.

  182565. */

  182566. static void nodeOverwriteCell(

  182567.   Rtree *pRtree,             /* The overall R-Tree */

  182568.   RtreeNode *pNode,          /* The node into which the cell is to be written */

  182569.   RtreeCell *pCell,          /* The cell to write */

  182570.   int iCell                  /* Index into pNode into which pCell is written */

  182571. ){

  182572.   int ii;

  182573.   u8 *p = &pNode->zData[4 + pRtree->nBytesPerCell*iCell];

  182574.   p += writeInt64(p, pCell->iRowid);

  182575.   for(ii=0; ii<pRtree->nDim2; ii++){

  182576.     p += writeCoord(p, &pCell->aCoord[ii]);

  182577.   }

  182578.   pNode->isDirty = 1;

  182579. }

  182580. 

  182581. /*

  182582. ** Remove the cell with index iCell from node pNode.

  182583. */

  182584. static void nodeDeleteCell(Rtree *pRtree, RtreeNode *pNode, int iCell){

  182585.   u8 *pDst = &pNode->zData[4 + pRtree->nBytesPerCell*iCell];

  182586.   u8 *pSrc = &pDst[pRtree->nBytesPerCell];

  182587.   int nByte = (NCELL(pNode) - iCell - 1) * pRtree->nBytesPerCell;

  182588.   memmove(pDst, pSrc, nByte);

  182589.   writeInt16(&pNode->zData[2], NCELL(pNode)-1);

  182590.   pNode->isDirty = 1;

  182591. }

  182592. 

  182593. /*

  182594. ** Insert the contents of cell pCell into node pNode. If the insert

  182595. ** is successful, return SQLITE_OK.

  182596. **

  182597. ** If there is not enough free space in pNode, return SQLITE_FULL.

  182598. */

  182599. static int nodeInsertCell(

  182600.   Rtree *pRtree,                /* The overall R-Tree */

  182601.   RtreeNode *pNode,             /* Write new cell into this node */

  182602.   RtreeCell *pCell              /* The cell to be inserted */

  182603. ){

  182604.   int nCell;                    /* Current number of cells in pNode */

  182605.   int nMaxCell;                 /* Maximum number of cells for pNode */

  182606. 

  182607.   nMaxCell = (pRtree->iNodeSize-4)/pRtree->nBytesPerCell;

  182608.   nCell = NCELL(pNode);

  182609. 

  182610.   assert( nCell<=nMaxCell );

  182611.   if( nCell<nMaxCell ){

  182612.     nodeOverwriteCell(pRtree, pNode, pCell, nCell);

  182613.     writeInt16(&pNode->zData[2], nCell+1);

  182614.     pNode->isDirty = 1;

  182615.   }

  182616. 

  182617.   return (nCell==nMaxCell);

  182618. }

  182619. 

  182620. /*

  182621. ** If the node is dirty, write it out to the database.

  182622. */

  182623. static int nodeWrite(Rtree *pRtree, RtreeNode *pNode){

  182624.   int rc = SQLITE_OK;

  182625.   if( pNode->isDirty ){

  182626.     sqlite3_stmt *p = pRtree->pWriteNode;

  182627.     if( pNode->iNode ){

  182628.       sqlite3_bind_int64(p, 1, pNode->iNode);

  182629.     }else{

  182630.       sqlite3_bind_null(p, 1);

  182631.     }

  182632.     sqlite3_bind_blob(p, 2, pNode->zData, pRtree->iNodeSize, SQLITE_STATIC);

  182633.     sqlite3_step(p);

  182634.     pNode->isDirty = 0;

  182635.     rc = sqlite3_reset(p);

  182636.     sqlite3_bind_null(p, 2);

  182637.     if( pNode->iNode==0 && rc==SQLITE_OK ){

  182638.       pNode->iNode = sqlite3_last_insert_rowid(pRtree->db);

  182639.       nodeHashInsert(pRtree, pNode);

  182640.     }

  182641.   }

  182642.   return rc;

  182643. }

  182644. 

  182645. /*

  182646. ** Release a reference to a node. If the node is dirty and the reference

  182647. ** count drops to zero, the node data is written to the database.

  182648. */

  182649. static int nodeRelease(Rtree *pRtree, RtreeNode *pNode){

  182650.   int rc = SQLITE_OK;

  182651.   if( pNode ){

  182652.     assert( pNode->nRef>0 );

  182653.     assert( pRtree->nNodeRef>0 );

  182654.     pNode->nRef--;

  182655.     if( pNode->nRef==0 ){

  182656.       pRtree->nNodeRef--;

  182657.       if( pNode->iNode==1 ){

  182658.         pRtree->iDepth = -1;

  182659.       }

  182660.       if( pNode->pParent ){

  182661.         rc = nodeRelease(pRtree, pNode->pParent);

  182662.       }

  182663.       if( rc==SQLITE_OK ){

  182664.         rc = nodeWrite(pRtree, pNode);

  182665.       }

  182666.       nodeHashDelete(pRtree, pNode);

  182667.       sqlite3_free(pNode);

  182668.     }

  182669.   }

  182670.   return rc;

  182671. }

  182672. 

  182673. /*

  182674. ** Return the 64-bit integer value associated with cell iCell of

  182675. ** node pNode. If pNode is a leaf node, this is a rowid. If it is

  182676. ** an internal node, then the 64-bit integer is a child page number.

  182677. */

  182678. static i64 nodeGetRowid(

  182679.   Rtree *pRtree,       /* The overall R-Tree */

  182680.   RtreeNode *pNode,    /* The node from which to extract the ID */

  182681.   int iCell            /* The cell index from which to extract the ID */

  182682. ){

  182683.   assert( iCell<NCELL(pNode) );

  182684.   return readInt64(&pNode->zData[4 + pRtree->nBytesPerCell*iCell]);

  182685. }

  182686. 

  182687. /*

  182688. ** Return coordinate iCoord from cell iCell in node pNode.

  182689. */

  182690. static void nodeGetCoord(

  182691.   Rtree *pRtree,               /* The overall R-Tree */

  182692.   RtreeNode *pNode,            /* The node from which to extract a coordinate */

  182693.   int iCell,                   /* The index of the cell within the node */

  182694.   int iCoord,                  /* Which coordinate to extract */

  182695.   RtreeCoord *pCoord           /* OUT: Space to write result to */

  182696. ){

  182697.   readCoord(&pNode->zData[12 + pRtree->nBytesPerCell*iCell + 4*iCoord], pCoord);

  182698. }

  182699. 

  182700. /*

  182701. ** Deserialize cell iCell of node pNode. Populate the structure pointed

  182702. ** to by pCell with the results.

  182703. */

  182704. static void nodeGetCell(

  182705.   Rtree *pRtree,               /* The overall R-Tree */

  182706.   RtreeNode *pNode,            /* The node containing the cell to be read */

  182707.   int iCell,                   /* Index of the cell within the node */

  182708.   RtreeCell *pCell             /* OUT: Write the cell contents here */

  182709. ){

  182710.   u8 *pData;

  182711.   RtreeCoord *pCoord;

  182712.   int ii = 0;

  182713.   pCell->iRowid = nodeGetRowid(pRtree, pNode, iCell);

  182714.   pData = pNode->zData + (12 + pRtree->nBytesPerCell*iCell);

  182715.   pCoord = pCell->aCoord;

  182716.   do{

  182717.     readCoord(pData, &pCoord[ii]);

  182718.     readCoord(pData+4, &pCoord[ii+1]);

  182719.     pData += 8;

  182720.     ii += 2;

  182721.   }while( ii<pRtree->nDim2 );

  182722. }

  182723. 

  182724. 

  182725. /* Forward declaration for the function that does the work of

  182726. ** the virtual table module xCreate() and xConnect() methods.

  182727. */

  182728. static int rtreeInit(

  182729.   sqlite3 *, void *, int, const char *const*, sqlite3_vtab **, char **, int

  182730. );

  182731. 

  182732. /* 

  182733. ** Rtree virtual table module xCreate method.

  182734. */

  182735. static int rtreeCreate(

  182736.   sqlite3 *db,

  182737.   void *pAux,

  182738.   int argc, const char *const*argv,

  182739.   sqlite3_vtab **ppVtab,

  182740.   char **pzErr

  182741. ){

  182742.   return rtreeInit(db, pAux, argc, argv, ppVtab, pzErr, 1);

  182743. }

  182744. 

  182745. /* 

  182746. ** Rtree virtual table module xConnect method.

  182747. */

  182748. static int rtreeConnect(

  182749.   sqlite3 *db,

  182750.   void *pAux,

  182751.   int argc, const char *const*argv,

  182752.   sqlite3_vtab **ppVtab,

  182753.   char **pzErr

  182754. ){

  182755.   return rtreeInit(db, pAux, argc, argv, ppVtab, pzErr, 0);

  182756. }

  182757. 

  182758. /*

  182759. ** Increment the r-tree reference count.

  182760. */

  182761. static void rtreeReference(Rtree *pRtree){

  182762.   pRtree->nBusy++;

  182763. }

  182764. 

  182765. /*

  182766. ** Decrement the r-tree reference count. When the reference count reaches

  182767. ** zero the structure is deleted.

  182768. */

  182769. static void rtreeRelease(Rtree *pRtree){

  182770.   pRtree->nBusy--;

  182771.   if( pRtree->nBusy==0 ){

  182772.     pRtree->inWrTrans = 0;

  182773.     assert( pRtree->nCursor==0 );

  182774.     nodeBlobReset(pRtree);

  182775.     assert( pRtree->nNodeRef==0 || pRtree->bCorrupt );

  182776.     sqlite3_finalize(pRtree->pWriteNode);

  182777.     sqlite3_finalize(pRtree->pDeleteNode);

  182778.     sqlite3_finalize(pRtree->pReadRowid);

  182779.     sqlite3_finalize(pRtree->pWriteRowid);

  182780.     sqlite3_finalize(pRtree->pDeleteRowid);

  182781.     sqlite3_finalize(pRtree->pReadParent);

  182782.     sqlite3_finalize(pRtree->pWriteParent);

  182783.     sqlite3_finalize(pRtree->pDeleteParent);

  182784.     sqlite3_finalize(pRtree->pWriteAux);

  182785.     sqlite3_free(pRtree->zReadAuxSql);

  182786.     sqlite3_free(pRtree);

  182787.   }

  182788. }

  182789. 

  182790. /* 

  182791. ** Rtree virtual table module xDisconnect method.

  182792. */

  182793. static int rtreeDisconnect(sqlite3_vtab *pVtab){

  182794.   rtreeRelease((Rtree *)pVtab);

  182795.   return SQLITE_OK;

  182796. }

  182797. 

  182798. /* 

  182799. ** Rtree virtual table module xDestroy method.

  182800. */

  182801. static int rtreeDestroy(sqlite3_vtab *pVtab){

  182802.   Rtree *pRtree = (Rtree *)pVtab;

  182803.   int rc;

  182804.   char *zCreate = sqlite3_mprintf(

  182805.     "DROP TABLE '%q'.'%q_node';"

  182806.     "DROP TABLE '%q'.'%q_rowid';"

  182807.     "DROP TABLE '%q'.'%q_parent';",

  182808.     pRtree->zDb, pRtree->zName, 

  182809.     pRtree->zDb, pRtree->zName,

  182810.     pRtree->zDb, pRtree->zName

  182811.   );

  182812.   if( !zCreate ){

  182813.     rc = SQLITE_NOMEM;

  182814.   }else{

  182815.     nodeBlobReset(pRtree);

  182816.     rc = sqlite3_exec(pRtree->db, zCreate, 0, 0, 0);

  182817.     sqlite3_free(zCreate);

  182818.   }

  182819.   if( rc==SQLITE_OK ){

  182820.     rtreeRelease(pRtree);

  182821.   }

  182822. 

  182823.   return rc;

  182824. }

  182825. 

  182826. /* 

  182827. ** Rtree virtual table module xOpen method.

  182828. */

  182829. static int rtreeOpen(sqlite3_vtab *pVTab, sqlite3_vtab_cursor **ppCursor){

  182830.   int rc = SQLITE_NOMEM;

  182831.   Rtree *pRtree = (Rtree *)pVTab;

  182832.   RtreeCursor *pCsr;

  182833. 

  182834.   pCsr = (RtreeCursor *)sqlite3_malloc64(sizeof(RtreeCursor));

  182835.   if( pCsr ){

  182836.     memset(pCsr, 0, sizeof(RtreeCursor));

  182837.     pCsr->base.pVtab = pVTab;

  182838.     rc = SQLITE_OK;

  182839.     pRtree->nCursor++;

  182840.   }

  182841.   *ppCursor = (sqlite3_vtab_cursor *)pCsr;

  182842. 

  182843.   return rc;

  182844. }

  182845. 

  182846. 

  182847. /*

  182848. ** Free the RtreeCursor.aConstraint[] array and its contents.

  182849. */

  182850. static void freeCursorConstraints(RtreeCursor *pCsr){

  182851.   if( pCsr->aConstraint ){

  182852.     int i;                        /* Used to iterate through constraint array */

  182853.     for(i=0; i<pCsr->nConstraint; i++){

  182854.       sqlite3_rtree_query_info *pInfo = pCsr->aConstraint[i].pInfo;

  182855.       if( pInfo ){

  182856.         if( pInfo->xDelUser ) pInfo->xDelUser(pInfo->pUser);

  182857.         sqlite3_free(pInfo);

  182858.       }

  182859.     }

  182860.     sqlite3_free(pCsr->aConstraint);

  182861.     pCsr->aConstraint = 0;

  182862.   }

  182863. }

  182864. 

  182865. /* 

  182866. ** Rtree virtual table module xClose method.

  182867. */

  182868. static int rtreeClose(sqlite3_vtab_cursor *cur){

  182869.   Rtree *pRtree = (Rtree *)(cur->pVtab);

  182870.   int ii;

  182871.   RtreeCursor *pCsr = (RtreeCursor *)cur;

  182872.   assert( pRtree->nCursor>0 );

  182873.   freeCursorConstraints(pCsr);

  182874.   sqlite3_finalize(pCsr->pReadAux);

  182875.   sqlite3_free(pCsr->aPoint);

  182876.   for(ii=0; ii<RTREE_CACHE_SZ; ii++) nodeRelease(pRtree, pCsr->aNode[ii]);

  182877.   sqlite3_free(pCsr);

  182878.   pRtree->nCursor--;

  182879.   nodeBlobReset(pRtree);

  182880.   return SQLITE_OK;

  182881. }

  182882. 

  182883. /*

  182884. ** Rtree virtual table module xEof method.

  182885. **

  182886. ** Return non-zero if the cursor does not currently point to a valid 

  182887. ** record (i.e if the scan has finished), or zero otherwise.

  182888. */

  182889. static int rtreeEof(sqlite3_vtab_cursor *cur){

  182890.   RtreeCursor *pCsr = (RtreeCursor *)cur;

  182891.   return pCsr->atEOF;

  182892. }

  182893. 

  182894. /*

  182895. ** Convert raw bits from the on-disk RTree record into a coordinate value.

  182896. ** The on-disk format is big-endian and needs to be converted for little-

  182897. ** endian platforms.  The on-disk record stores integer coordinates if

  182898. ** eInt is true and it stores 32-bit floating point records if eInt is

  182899. ** false.  a[] is the four bytes of the on-disk record to be decoded.

  182900. ** Store the results in "r".

  182901. **

  182902. ** There are five versions of this macro.  The last one is generic.  The

  182903. ** other four are various architectures-specific optimizations.

  182904. */

  182905. #if SQLITE_BYTEORDER==1234 && MSVC_VERSION>=1300

  182906. #define RTREE_DECODE_COORD(eInt, a, r) {                        \

  182907.     RtreeCoord c;    /* Coordinate decoded */                   \

  182908.     c.u = _byteswap_ulong(*(u32*)a);                            \

  182909.     r = eInt ? (sqlite3_rtree_dbl)c.i : (sqlite3_rtree_dbl)c.f; \

  182910. }

  182911. #elif SQLITE_BYTEORDER==1234 && GCC_VERSION>=4003000

  182912. #define RTREE_DECODE_COORD(eInt, a, r) {                        \

  182913.     RtreeCoord c;    /* Coordinate decoded */                   \

  182914.     c.u = __builtin_bswap32(*(u32*)a);                          \

  182915.     r = eInt ? (sqlite3_rtree_dbl)c.i : (sqlite3_rtree_dbl)c.f; \

  182916. }

  182917. #elif SQLITE_BYTEORDER==1234

  182918. #define RTREE_DECODE_COORD(eInt, a, r) {                        \

  182919.     RtreeCoord c;    /* Coordinate decoded */                   \

  182920.     memcpy(&c.u,a,4);                                           \

  182921.     c.u = ((c.u>>24)&0xff)|((c.u>>8)&0xff00)|                   \

  182922.           ((c.u&0xff)<<24)|((c.u&0xff00)<<8);                   \

  182923.     r = eInt ? (sqlite3_rtree_dbl)c.i : (sqlite3_rtree_dbl)c.f; \

  182924. }

  182925. #elif SQLITE_BYTEORDER==4321

  182926. #define RTREE_DECODE_COORD(eInt, a, r) {                        \

  182927.     RtreeCoord c;    /* Coordinate decoded */                   \

  182928.     memcpy(&c.u,a,4);                                           \

  182929.     r = eInt ? (sqlite3_rtree_dbl)c.i : (sqlite3_rtree_dbl)c.f; \

  182930. }

  182931. #else

  182932. #define RTREE_DECODE_COORD(eInt, a, r) {                        \

  182933.     RtreeCoord c;    /* Coordinate decoded */                   \

  182934.     c.u = ((u32)a[0]<<24) + ((u32)a[1]<<16)                     \

  182935.            +((u32)a[2]<<8) + a[3];                              \

  182936.     r = eInt ? (sqlite3_rtree_dbl)c.i : (sqlite3_rtree_dbl)c.f; \

  182937. }

  182938. #endif

  182939. 

  182940. /*

  182941. ** Check the RTree node or entry given by pCellData and p against the MATCH

  182942. ** constraint pConstraint.  

  182943. */

  182944. static int rtreeCallbackConstraint(

  182945.   RtreeConstraint *pConstraint,  /* The constraint to test */

  182946.   int eInt,                      /* True if RTree holding integer coordinates */

  182947.   u8 *pCellData,                 /* Raw cell content */

  182948.   RtreeSearchPoint *pSearch,     /* Container of this cell */

  182949.   sqlite3_rtree_dbl *prScore,    /* OUT: score for the cell */

  182950.   int *peWithin                  /* OUT: visibility of the cell */

  182951. ){

  182952.   sqlite3_rtree_query_info *pInfo = pConstraint->pInfo; /* Callback info */

  182953.   int nCoord = pInfo->nCoord;                           /* No. of coordinates */

  182954.   int rc;                                             /* Callback return code */

  182955.   RtreeCoord c;                                       /* Translator union */

  182956.   sqlite3_rtree_dbl aCoord[RTREE_MAX_DIMENSIONS*2];   /* Decoded coordinates */

  182957. 

  182958.   assert( pConstraint->op==RTREE_MATCH || pConstraint->op==RTREE_QUERY );

  182959.   assert( nCoord==2 || nCoord==4 || nCoord==6 || nCoord==8 || nCoord==10 );

  182960. 

  182961.   if( pConstraint->op==RTREE_QUERY && pSearch->iLevel==1 ){

  182962.     pInfo->iRowid = readInt64(pCellData);

  182963.   }

  182964.   pCellData += 8;

  182965. #ifndef SQLITE_RTREE_INT_ONLY

  182966.   if( eInt==0 ){

  182967.     switch( nCoord ){

  182968.       case 10:  readCoord(pCellData+36, &c); aCoord[9] = c.f;

  182969.                 readCoord(pCellData+32, &c); aCoord[8] = c.f;

  182970.       case 8:   readCoord(pCellData+28, &c); aCoord[7] = c.f;

  182971.                 readCoord(pCellData+24, &c); aCoord[6] = c.f;

  182972.       case 6:   readCoord(pCellData+20, &c); aCoord[5] = c.f;

  182973.                 readCoord(pCellData+16, &c); aCoord[4] = c.f;

  182974.       case 4:   readCoord(pCellData+12, &c); aCoord[3] = c.f;

  182975.                 readCoord(pCellData+8,  &c); aCoord[2] = c.f;

  182976.       default:  readCoord(pCellData+4,  &c); aCoord[1] = c.f;

  182977.                 readCoord(pCellData,    &c); aCoord[0] = c.f;

  182978.     }

  182979.   }else

  182980. #endif

  182981.   {

  182982.     switch( nCoord ){

  182983.       case 10:  readCoord(pCellData+36, &c); aCoord[9] = c.i;

  182984.                 readCoord(pCellData+32, &c); aCoord[8] = c.i;

  182985.       case 8:   readCoord(pCellData+28, &c); aCoord[7] = c.i;

  182986.                 readCoord(pCellData+24, &c); aCoord[6] = c.i;

  182987.       case 6:   readCoord(pCellData+20, &c); aCoord[5] = c.i;

  182988.                 readCoord(pCellData+16, &c); aCoord[4] = c.i;

  182989.       case 4:   readCoord(pCellData+12, &c); aCoord[3] = c.i;

  182990.                 readCoord(pCellData+8,  &c); aCoord[2] = c.i;

  182991.       default:  readCoord(pCellData+4,  &c); aCoord[1] = c.i;

  182992.                 readCoord(pCellData,    &c); aCoord[0] = c.i;

  182993.     }

  182994.   }

  182995.   if( pConstraint->op==RTREE_MATCH ){

  182996.     int eWithin = 0;

  182997.     rc = pConstraint->u.xGeom((sqlite3_rtree_geometry*)pInfo,

  182998.                               nCoord, aCoord, &eWithin);

  182999.     if( eWithin==0 ) *peWithin = NOT_WITHIN;

  183000.     *prScore = RTREE_ZERO;

  183001.   }else{

  183002.     pInfo->aCoord = aCoord;

  183003.     pInfo->iLevel = pSearch->iLevel - 1;

  183004.     pInfo->rScore = pInfo->rParentScore = pSearch->rScore;

  183005.     pInfo->eWithin = pInfo->eParentWithin = pSearch->eWithin;

  183006.     rc = pConstraint->u.xQueryFunc(pInfo);

  183007.     if( pInfo->eWithin<*peWithin ) *peWithin = pInfo->eWithin;

  183008.     if( pInfo->rScore<*prScore || *prScore<RTREE_ZERO ){

  183009.       *prScore = pInfo->rScore;

  183010.     }

  183011.   }

  183012.   return rc;

  183013. }

  183014. 

  183015. /* 

  183016. ** Check the internal RTree node given by pCellData against constraint p.

  183017. ** If this constraint cannot be satisfied by any child within the node,

  183018. ** set *peWithin to NOT_WITHIN.

  183019. */

  183020. static void rtreeNonleafConstraint(

  183021.   RtreeConstraint *p,        /* The constraint to test */

  183022.   int eInt,                  /* True if RTree holds integer coordinates */

  183023.   u8 *pCellData,             /* Raw cell content as appears on disk */

  183024.   int *peWithin              /* Adjust downward, as appropriate */

  183025. ){

  183026.   sqlite3_rtree_dbl val;     /* Coordinate value convert to a double */

  183027. 

  183028.   /* p->iCoord might point to either a lower or upper bound coordinate

  183029.   ** in a coordinate pair.  But make pCellData point to the lower bound.

  183030.   */

  183031.   pCellData += 8 + 4*(p->iCoord&0xfe);

  183032. 

  183033.   assert(p->op==RTREE_LE || p->op==RTREE_LT || p->op==RTREE_GE 

  183034.       || p->op==RTREE_GT || p->op==RTREE_EQ );

  183035.   assert( ((((char*)pCellData) - (char*)0)&3)==0 );  /* 4-byte aligned */

  183036.   switch( p->op ){

  183037.     case RTREE_LE:

  183038.     case RTREE_LT:

  183039.     case RTREE_EQ:

  183040.       RTREE_DECODE_COORD(eInt, pCellData, val);

  183041.       /* val now holds the lower bound of the coordinate pair */

  183042.       if( p->u.rValue>=val ) return;

  183043.       if( p->op!=RTREE_EQ ) break;  /* RTREE_LE and RTREE_LT end here */

  183044.       /* Fall through for the RTREE_EQ case */

  183045. 

  183046.     default: /* RTREE_GT or RTREE_GE,  or fallthrough of RTREE_EQ */

  183047.       pCellData += 4;

  183048.       RTREE_DECODE_COORD(eInt, pCellData, val);

  183049.       /* val now holds the upper bound of the coordinate pair */

  183050.       if( p->u.rValue<=val ) return;

  183051.   }

  183052.   *peWithin = NOT_WITHIN;

  183053. }

  183054. 

  183055. /*

  183056. ** Check the leaf RTree cell given by pCellData against constraint p.

  183057. ** If this constraint is not satisfied, set *peWithin to NOT_WITHIN.

  183058. ** If the constraint is satisfied, leave *peWithin unchanged.

  183059. **

  183060. ** The constraint is of the form:  xN op $val

  183061. **

  183062. ** The op is given by p->op.  The xN is p->iCoord-th coordinate in

  183063. ** pCellData.  $val is given by p->u.rValue.

  183064. */

  183065. static void rtreeLeafConstraint(

  183066.   RtreeConstraint *p,        /* The constraint to test */

  183067.   int eInt,                  /* True if RTree holds integer coordinates */

  183068.   u8 *pCellData,             /* Raw cell content as appears on disk */

  183069.   int *peWithin              /* Adjust downward, as appropriate */

  183070. ){

  183071.   RtreeDValue xN;      /* Coordinate value converted to a double */

  183072. 

  183073.   assert(p->op==RTREE_LE || p->op==RTREE_LT || p->op==RTREE_GE 

  183074.       || p->op==RTREE_GT || p->op==RTREE_EQ );

  183075.   pCellData += 8 + p->iCoord*4;

  183076.   assert( ((((char*)pCellData) - (char*)0)&3)==0 );  /* 4-byte aligned */

  183077.   RTREE_DECODE_COORD(eInt, pCellData, xN);

  183078.   switch( p->op ){

  183079.     case RTREE_LE: if( xN <= p->u.rValue ) return;  break;

  183080.     case RTREE_LT: if( xN <  p->u.rValue ) return;  break;

  183081.     case RTREE_GE: if( xN >= p->u.rValue ) return;  break;

  183082.     case RTREE_GT: if( xN >  p->u.rValue ) return;  break;

  183083.     default:       if( xN == p->u.rValue ) return;  break;

  183084.   }

  183085.   *peWithin = NOT_WITHIN;

  183086. }

  183087. 

  183088. /*

  183089. ** One of the cells in node pNode is guaranteed to have a 64-bit 

  183090. ** integer value equal to iRowid. Return the index of this cell.

  183091. */

  183092. static int nodeRowidIndex(

  183093.   Rtree *pRtree, 

  183094.   RtreeNode *pNode, 

  183095.   i64 iRowid,

  183096.   int *piIndex

  183097. ){

  183098.   int ii;

  183099.   int nCell = NCELL(pNode);

  183100.   assert( nCell<200 );

  183101.   for(ii=0; ii<nCell; ii++){

  183102.     if( nodeGetRowid(pRtree, pNode, ii)==iRowid ){

  183103.       *piIndex = ii;

  183104.       return SQLITE_OK;

  183105.     }

  183106.   }

  183107.   RTREE_IS_CORRUPT(pRtree);

  183108.   return SQLITE_CORRUPT_VTAB;

  183109. }

  183110. 

  183111. /*

  183112. ** Return the index of the cell containing a pointer to node pNode

  183113. ** in its parent. If pNode is the root node, return -1.

  183114. */

  183115. static int nodeParentIndex(Rtree *pRtree, RtreeNode *pNode, int *piIndex){

  183116.   RtreeNode *pParent = pNode->pParent;

  183117.   if( pParent ){

  183118.     return nodeRowidIndex(pRtree, pParent, pNode->iNode, piIndex);

  183119.   }

  183120.   *piIndex = -1;

  183121.   return SQLITE_OK;

  183122. }

  183123. 

  183124. /*

  183125. ** Compare two search points.  Return negative, zero, or positive if the first

  183126. ** is less than, equal to, or greater than the second.

  183127. **

  183128. ** The rScore is the primary key.  Smaller rScore values come first.

  183129. ** If the rScore is a tie, then use iLevel as the tie breaker with smaller

  183130. ** iLevel values coming first.  In this way, if rScore is the same for all

  183131. ** SearchPoints, then iLevel becomes the deciding factor and the result

  183132. ** is a depth-first search, which is the desired default behavior.

  183133. */

  183134. static int rtreeSearchPointCompare(

  183135.   const RtreeSearchPoint *pA,

  183136.   const RtreeSearchPoint *pB

  183137. ){

  183138.   if( pA->rScore<pB->rScore ) return -1;

  183139.   if( pA->rScore>pB->rScore ) return +1;

  183140.   if( pA->iLevel<pB->iLevel ) return -1;

  183141.   if( pA->iLevel>pB->iLevel ) return +1;

  183142.   return 0;

  183143. }

  183144. 

  183145. /*

  183146. ** Interchange two search points in a cursor.

  183147. */

  183148. static void rtreeSearchPointSwap(RtreeCursor *p, int i, int j){

  183149.   RtreeSearchPoint t = p->aPoint[i];

  183150.   assert( i<j );

  183151.   p->aPoint[i] = p->aPoint[j];

  183152.   p->aPoint[j] = t;

  183153.   i++; j++;

  183154.   if( i<RTREE_CACHE_SZ ){

  183155.     if( j>=RTREE_CACHE_SZ ){

  183156.       nodeRelease(RTREE_OF_CURSOR(p), p->aNode[i]);

  183157.       p->aNode[i] = 0;

  183158.     }else{

  183159.       RtreeNode *pTemp = p->aNode[i];

  183160.       p->aNode[i] = p->aNode[j];

  183161.       p->aNode[j] = pTemp;

  183162.     }

  183163.   }

  183164. }

  183165. 

  183166. /*

  183167. ** Return the search point with the lowest current score.

  183168. */

  183169. static RtreeSearchPoint *rtreeSearchPointFirst(RtreeCursor *pCur){

  183170.   return pCur->bPoint ? &pCur->sPoint : pCur->nPoint ? pCur->aPoint : 0;

  183171. }

  183172. 

  183173. /*

  183174. ** Get the RtreeNode for the search point with the lowest score.

  183175. */

  183176. static RtreeNode *rtreeNodeOfFirstSearchPoint(RtreeCursor *pCur, int *pRC){

  183177.   sqlite3_int64 id;

  183178.   int ii = 1 - pCur->bPoint;

  183179.   assert( ii==0 || ii==1 );

  183180.   assert( pCur->bPoint || pCur->nPoint );

  183181.   if( pCur->aNode[ii]==0 ){

  183182.     assert( pRC!=0 );

  183183.     id = ii ? pCur->aPoint[0].id : pCur->sPoint.id;

  183184.     *pRC = nodeAcquire(RTREE_OF_CURSOR(pCur), id, 0, &pCur->aNode[ii]);

  183185.   }

  183186.   return pCur->aNode[ii];

  183187. }

  183188. 

  183189. /*

  183190. ** Push a new element onto the priority queue

  183191. */

  183192. static RtreeSearchPoint *rtreeEnqueue(

  183193.   RtreeCursor *pCur,    /* The cursor */

  183194.   RtreeDValue rScore,   /* Score for the new search point */

  183195.   u8 iLevel             /* Level for the new search point */

  183196. ){

  183197.   int i, j;

  183198.   RtreeSearchPoint *pNew;

  183199.   if( pCur->nPoint>=pCur->nPointAlloc ){

  183200.     int nNew = pCur->nPointAlloc*2 + 8;

  183201.     pNew = sqlite3_realloc64(pCur->aPoint, nNew*sizeof(pCur->aPoint[0]));

  183202.     if( pNew==0 ) return 0;

  183203.     pCur->aPoint = pNew;

  183204.     pCur->nPointAlloc = nNew;

  183205.   }

  183206.   i = pCur->nPoint++;

  183207.   pNew = pCur->aPoint + i;

  183208.   pNew->rScore = rScore;

  183209.   pNew->iLevel = iLevel;

  183210.   assert( iLevel<=RTREE_MAX_DEPTH );

  183211.   while( i>0 ){

  183212.     RtreeSearchPoint *pParent;

  183213.     j = (i-1)/2;

  183214.     pParent = pCur->aPoint + j;

  183215.     if( rtreeSearchPointCompare(pNew, pParent)>=0 ) break;

  183216.     rtreeSearchPointSwap(pCur, j, i);

  183217.     i = j;

  183218.     pNew = pParent;

  183219.   }

  183220.   return pNew;

  183221. }

  183222. 

  183223. /*

  183224. ** Allocate a new RtreeSearchPoint and return a pointer to it.  Return

  183225. ** NULL if malloc fails.

  183226. */

  183227. static RtreeSearchPoint *rtreeSearchPointNew(

  183228.   RtreeCursor *pCur,    /* The cursor */

  183229.   RtreeDValue rScore,   /* Score for the new search point */

  183230.   u8 iLevel             /* Level for the new search point */

  183231. ){

  183232.   RtreeSearchPoint *pNew, *pFirst;

  183233.   pFirst = rtreeSearchPointFirst(pCur);

  183234.   pCur->anQueue[iLevel]++;

  183235.   if( pFirst==0

  183236.    || pFirst->rScore>rScore 

  183237.    || (pFirst->rScore==rScore && pFirst->iLevel>iLevel)

  183238.   ){

  183239.     if( pCur->bPoint ){

  183240.       int ii;

  183241.       pNew = rtreeEnqueue(pCur, rScore, iLevel);

  183242.       if( pNew==0 ) return 0;

  183243.       ii = (int)(pNew - pCur->aPoint) + 1;

  183244.       if( ii<RTREE_CACHE_SZ ){

  183245.         assert( pCur->aNode[ii]==0 );

  183246.         pCur->aNode[ii] = pCur->aNode[0];

  183247.       }else{

  183248.         nodeRelease(RTREE_OF_CURSOR(pCur), pCur->aNode[0]);

  183249.       }

  183250.       pCur->aNode[0] = 0;

  183251.       *pNew = pCur->sPoint;

  183252.     }

  183253.     pCur->sPoint.rScore = rScore;

  183254.     pCur->sPoint.iLevel = iLevel;

  183255.     pCur->bPoint = 1;

  183256.     return &pCur->sPoint;

  183257.   }else{

  183258.     return rtreeEnqueue(pCur, rScore, iLevel);

  183259.   }

  183260. }

  183261. 

  183262. #if 0

  183263. /* Tracing routines for the RtreeSearchPoint queue */

  183264. static void tracePoint(RtreeSearchPoint *p, int idx, RtreeCursor *pCur){

  183265.   if( idx<0 ){ printf(" s"); }else{ printf("%2d", idx); }

  183266.   printf(" %d.%05lld.%02d %g %d",

  183267.     p->iLevel, p->id, p->iCell, p->rScore, p->eWithin

  183268.   );

  183269.   idx++;

  183270.   if( idx<RTREE_CACHE_SZ ){

  183271.     printf(" %p\n", pCur->aNode[idx]);

  183272.   }else{

  183273.     printf("\n");

  183274.   }

  183275. }

  183276. static void traceQueue(RtreeCursor *pCur, const char *zPrefix){

  183277.   int ii;

  183278.   printf("=== %9s ", zPrefix);

  183279.   if( pCur->bPoint ){

  183280.     tracePoint(&pCur->sPoint, -1, pCur);

  183281.   }

  183282.   for(ii=0; ii<pCur->nPoint; ii++){

  183283.     if( ii>0 || pCur->bPoint ) printf("              ");

  183284.     tracePoint(&pCur->aPoint[ii], ii, pCur);

  183285.   }

  183286. }

  183287. # define RTREE_QUEUE_TRACE(A,B) traceQueue(A,B)

  183288. #else

  183289. # define RTREE_QUEUE_TRACE(A,B)   /* no-op */

  183290. #endif

  183291. 

  183292. /* Remove the search point with the lowest current score.

  183293. */

  183294. static void rtreeSearchPointPop(RtreeCursor *p){

  183295.   int i, j, k, n;

  183296.   i = 1 - p->bPoint;

  183297.   assert( i==0 || i==1 );

  183298.   if( p->aNode[i] ){

  183299.     nodeRelease(RTREE_OF_CURSOR(p), p->aNode[i]);

  183300.     p->aNode[i] = 0;

  183301.   }

  183302.   if( p->bPoint ){

  183303.     p->anQueue[p->sPoint.iLevel]--;

  183304.     p->bPoint = 0;

  183305.   }else if( p->nPoint ){

  183306.     p->anQueue[p->aPoint[0].iLevel]--;

  183307.     n = --p->nPoint;

  183308.     p->aPoint[0] = p->aPoint[n];

  183309.     if( n<RTREE_CACHE_SZ-1 ){

  183310.       p->aNode[1] = p->aNode[n+1];

  183311.       p->aNode[n+1] = 0;

  183312.     }

  183313.     i = 0;

  183314.     while( (j = i*2+1)<n ){

  183315.       k = j+1;

  183316.       if( k<n && rtreeSearchPointCompare(&p->aPoint[k], &p->aPoint[j])<0 ){

  183317.         if( rtreeSearchPointCompare(&p->aPoint[k], &p->aPoint[i])<0 ){

  183318.           rtreeSearchPointSwap(p, i, k);

  183319.           i = k;

  183320.         }else{

  183321.           break;

  183322.         }

  183323.       }else{

  183324.         if( rtreeSearchPointCompare(&p->aPoint[j], &p->aPoint[i])<0 ){

  183325.           rtreeSearchPointSwap(p, i, j);

  183326.           i = j;

  183327.         }else{

  183328.           break;

  183329.         }

  183330.       }

  183331.     }

  183332.   }

  183333. }

  183334. 

  183335. 

  183336. /*

  183337. ** Continue the search on cursor pCur until the front of the queue

  183338. ** contains an entry suitable for returning as a result-set row,

  183339. ** or until the RtreeSearchPoint queue is empty, indicating that the

  183340. ** query has completed.

  183341. */

  183342. static int rtreeStepToLeaf(RtreeCursor *pCur){

  183343.   RtreeSearchPoint *p;

  183344.   Rtree *pRtree = RTREE_OF_CURSOR(pCur);

  183345.   RtreeNode *pNode;

  183346.   int eWithin;

  183347.   int rc = SQLITE_OK;

  183348.   int nCell;

  183349.   int nConstraint = pCur->nConstraint;

  183350.   int ii;

  183351.   int eInt;

  183352.   RtreeSearchPoint x;

  183353. 

  183354.   eInt = pRtree->eCoordType==RTREE_COORD_INT32;

  183355.   while( (p = rtreeSearchPointFirst(pCur))!=0 && p->iLevel>0 ){

  183356.     pNode = rtreeNodeOfFirstSearchPoint(pCur, &rc);

  183357.     if( rc ) return rc;

  183358.     nCell = NCELL(pNode);

  183359.     assert( nCell<200 );

  183360.     while( p->iCell<nCell ){

  183361.       sqlite3_rtree_dbl rScore = (sqlite3_rtree_dbl)-1;

  183362.       u8 *pCellData = pNode->zData + (4+pRtree->nBytesPerCell*p->iCell);

  183363.       eWithin = FULLY_WITHIN;

  183364.       for(ii=0; ii<nConstraint; ii++){

  183365.         RtreeConstraint *pConstraint = pCur->aConstraint + ii;

  183366.         if( pConstraint->op>=RTREE_MATCH ){

  183367.           rc = rtreeCallbackConstraint(pConstraint, eInt, pCellData, p,

  183368.                                        &rScore, &eWithin);

  183369.           if( rc ) return rc;

  183370.         }else if( p->iLevel==1 ){

  183371.           rtreeLeafConstraint(pConstraint, eInt, pCellData, &eWithin);

  183372.         }else{

  183373.           rtreeNonleafConstraint(pConstraint, eInt, pCellData, &eWithin);

  183374.         }

  183375.         if( eWithin==NOT_WITHIN ) break;

  183376.       }

  183377.       p->iCell++;

  183378.       if( eWithin==NOT_WITHIN ) continue;

  183379.       x.iLevel = p->iLevel - 1;

  183380.       if( x.iLevel ){

  183381.         x.id = readInt64(pCellData);

  183382.         x.iCell = 0;

  183383.       }else{

  183384.         x.id = p->id;

  183385.         x.iCell = p->iCell - 1;

  183386.       }

  183387.       if( p->iCell>=nCell ){

  183388.         RTREE_QUEUE_TRACE(pCur, "POP-S:");

  183389.         rtreeSearchPointPop(pCur);

  183390.       }

  183391.       if( rScore<RTREE_ZERO ) rScore = RTREE_ZERO;

  183392.       p = rtreeSearchPointNew(pCur, rScore, x.iLevel);

  183393.       if( p==0 ) return SQLITE_NOMEM;

  183394.       p->eWithin = (u8)eWithin;

  183395.       p->id = x.id;

  183396.       p->iCell = x.iCell;

  183397.       RTREE_QUEUE_TRACE(pCur, "PUSH-S:");

  183398.       break;

  183399.     }

  183400.     if( p->iCell>=nCell ){

  183401.       RTREE_QUEUE_TRACE(pCur, "POP-Se:");

  183402.       rtreeSearchPointPop(pCur);

  183403.     }

  183404.   }

  183405.   pCur->atEOF = p==0;

  183406.   return SQLITE_OK;

  183407. }

  183408. 

  183409. /* 

  183410. ** Rtree virtual table module xNext method.

  183411. */

  183412. static int rtreeNext(sqlite3_vtab_cursor *pVtabCursor){

  183413.   RtreeCursor *pCsr = (RtreeCursor *)pVtabCursor;

  183414.   int rc = SQLITE_OK;

  183415. 

  183416.   /* Move to the next entry that matches the configured constraints. */

  183417.   RTREE_QUEUE_TRACE(pCsr, "POP-Nx:");

  183418.   if( pCsr->bAuxValid ){

  183419.     pCsr->bAuxValid = 0;

  183420.     sqlite3_reset(pCsr->pReadAux);

  183421.   }

  183422.   rtreeSearchPointPop(pCsr);

  183423.   rc = rtreeStepToLeaf(pCsr);

  183424.   return rc;

  183425. }

  183426. 

  183427. /* 

  183428. ** Rtree virtual table module xRowid method.

  183429. */

  183430. static int rtreeRowid(sqlite3_vtab_cursor *pVtabCursor, sqlite_int64 *pRowid){

  183431.   RtreeCursor *pCsr = (RtreeCursor *)pVtabCursor;

  183432.   RtreeSearchPoint *p = rtreeSearchPointFirst(pCsr);

  183433.   int rc = SQLITE_OK;

  183434.   RtreeNode *pNode = rtreeNodeOfFirstSearchPoint(pCsr, &rc);

  183435.   if( rc==SQLITE_OK && p ){

  183436.     *pRowid = nodeGetRowid(RTREE_OF_CURSOR(pCsr), pNode, p->iCell);

  183437.   }

  183438.   return rc;

  183439. }

  183440. 

  183441. /* 

  183442. ** Rtree virtual table module xColumn method.

  183443. */

  183444. static int rtreeColumn(sqlite3_vtab_cursor *cur, sqlite3_context *ctx, int i){

  183445.   Rtree *pRtree = (Rtree *)cur->pVtab;

  183446.   RtreeCursor *pCsr = (RtreeCursor *)cur;

  183447.   RtreeSearchPoint *p = rtreeSearchPointFirst(pCsr);

  183448.   RtreeCoord c;

  183449.   int rc = SQLITE_OK;

  183450.   RtreeNode *pNode = rtreeNodeOfFirstSearchPoint(pCsr, &rc);

  183451. 

  183452.   if( rc ) return rc;

  183453.   if( p==0 ) return SQLITE_OK;

  183454.   if( i==0 ){

  183455.     sqlite3_result_int64(ctx, nodeGetRowid(pRtree, pNode, p->iCell));

  183456.   }else if( i<=pRtree->nDim2 ){

  183457.     nodeGetCoord(pRtree, pNode, p->iCell, i-1, &c);

  183458. #ifndef SQLITE_RTREE_INT_ONLY

  183459.     if( pRtree->eCoordType==RTREE_COORD_REAL32 ){

  183460.       sqlite3_result_double(ctx, c.f);

  183461.     }else

  183462. #endif

  183463.     {

  183464.       assert( pRtree->eCoordType==RTREE_COORD_INT32 );

  183465.       sqlite3_result_int(ctx, c.i);

  183466.     }

  183467.   }else{

  183468.     if( !pCsr->bAuxValid ){

  183469.       if( pCsr->pReadAux==0 ){

  183470.         rc = sqlite3_prepare_v3(pRtree->db, pRtree->zReadAuxSql, -1, 0,

  183471.                                 &pCsr->pReadAux, 0);

  183472.         if( rc ) return rc;

  183473.       }

  183474.       sqlite3_bind_int64(pCsr->pReadAux, 1, 

  183475.           nodeGetRowid(pRtree, pNode, p->iCell));

  183476.       rc = sqlite3_step(pCsr->pReadAux);

  183477.       if( rc==SQLITE_ROW ){

  183478.         pCsr->bAuxValid = 1;

  183479.       }else{

  183480.         sqlite3_reset(pCsr->pReadAux);

  183481.         if( rc==SQLITE_DONE ) rc = SQLITE_OK;

  183482.         return rc;

  183483.       }

  183484.     }

  183485.     sqlite3_result_value(ctx,

  183486.          sqlite3_column_value(pCsr->pReadAux, i - pRtree->nDim2 + 1));

  183487.   }  

  183488.   return SQLITE_OK;

  183489. }

  183490. 

  183491. /* 

  183492. ** Use nodeAcquire() to obtain the leaf node containing the record with 

  183493. ** rowid iRowid. If successful, set *ppLeaf to point to the node and

  183494. ** return SQLITE_OK. If there is no such record in the table, set

  183495. ** *ppLeaf to 0 and return SQLITE_OK. If an error occurs, set *ppLeaf

  183496. ** to zero and return an SQLite error code.

  183497. */

  183498. static int findLeafNode(

  183499.   Rtree *pRtree,              /* RTree to search */

  183500.   i64 iRowid,                 /* The rowid searching for */

  183501.   RtreeNode **ppLeaf,         /* Write the node here */

  183502.   sqlite3_int64 *piNode       /* Write the node-id here */

  183503. ){

  183504.   int rc;

  183505.   *ppLeaf = 0;

  183506.   sqlite3_bind_int64(pRtree->pReadRowid, 1, iRowid);

  183507.   if( sqlite3_step(pRtree->pReadRowid)==SQLITE_ROW ){

  183508.     i64 iNode = sqlite3_column_int64(pRtree->pReadRowid, 0);

  183509.     if( piNode ) *piNode = iNode;

  183510.     rc = nodeAcquire(pRtree, iNode, 0, ppLeaf);

  183511.     sqlite3_reset(pRtree->pReadRowid);

  183512.   }else{

  183513.     rc = sqlite3_reset(pRtree->pReadRowid);

  183514.   }

  183515.   return rc;

  183516. }

  183517. 

  183518. /*

  183519. ** This function is called to configure the RtreeConstraint object passed

  183520. ** as the second argument for a MATCH constraint. The value passed as the

  183521. ** first argument to this function is the right-hand operand to the MATCH

  183522. ** operator.

  183523. */

  183524. static int deserializeGeometry(sqlite3_value *pValue, RtreeConstraint *pCons){

  183525.   RtreeMatchArg *pBlob, *pSrc;       /* BLOB returned by geometry function */

  183526.   sqlite3_rtree_query_info *pInfo;   /* Callback information */

  183527. 

  183528.   pSrc = sqlite3_value_pointer(pValue, "RtreeMatchArg");

  183529.   if( pSrc==0 ) return SQLITE_ERROR;

  183530.   pInfo = (sqlite3_rtree_query_info*)

  183531.                 sqlite3_malloc64( sizeof(*pInfo)+pSrc->iSize );

  183532.   if( !pInfo ) return SQLITE_NOMEM;

  183533.   memset(pInfo, 0, sizeof(*pInfo));

  183534.   pBlob = (RtreeMatchArg*)&pInfo[1];

  183535.   memcpy(pBlob, pSrc, pSrc->iSize);

  183536.   pInfo->pContext = pBlob->cb.pContext;

  183537.   pInfo->nParam = pBlob->nParam;

  183538.   pInfo->aParam = pBlob->aParam;

  183539.   pInfo->apSqlParam = pBlob->apSqlParam;

  183540. 

  183541.   if( pBlob->cb.xGeom ){

  183542.     pCons->u.xGeom = pBlob->cb.xGeom;

  183543.   }else{

  183544.     pCons->op = RTREE_QUERY;

  183545.     pCons->u.xQueryFunc = pBlob->cb.xQueryFunc;

  183546.   }

  183547.   pCons->pInfo = pInfo;

  183548.   return SQLITE_OK;

  183549. }

  183550. 

  183551. /* 

  183552. ** Rtree virtual table module xFilter method.

  183553. */

  183554. static int rtreeFilter(

  183555.   sqlite3_vtab_cursor *pVtabCursor, 

  183556.   int idxNum, const char *idxStr,

  183557.   int argc, sqlite3_value **argv

  183558. ){

  183559.   Rtree *pRtree = (Rtree *)pVtabCursor->pVtab;

  183560.   RtreeCursor *pCsr = (RtreeCursor *)pVtabCursor;

  183561.   RtreeNode *pRoot = 0;

  183562.   int ii;

  183563.   int rc = SQLITE_OK;

  183564.   int iCell = 0;

  183565.   sqlite3_stmt *pStmt;

  183566. 

  183567.   rtreeReference(pRtree);

  183568. 

  183569.   /* Reset the cursor to the same state as rtreeOpen() leaves it in. */

  183570.   freeCursorConstraints(pCsr);

  183571.   sqlite3_free(pCsr->aPoint);

  183572.   pStmt = pCsr->pReadAux;

  183573.   memset(pCsr, 0, sizeof(RtreeCursor));

  183574.   pCsr->base.pVtab = (sqlite3_vtab*)pRtree;

  183575.   pCsr->pReadAux = pStmt;

  183576. 

  183577.   pCsr->iStrategy = idxNum;

  183578.   if( idxNum==1 ){

  183579.     /* Special case - lookup by rowid. */

  183580.     RtreeNode *pLeaf;        /* Leaf on which the required cell resides */

  183581.     RtreeSearchPoint *p;     /* Search point for the leaf */

  183582.     i64 iRowid = sqlite3_value_int64(argv[0]);

  183583.     i64 iNode = 0;

  183584.     rc = findLeafNode(pRtree, iRowid, &pLeaf, &iNode);

  183585.     if( rc==SQLITE_OK && pLeaf!=0 ){

  183586.       p = rtreeSearchPointNew(pCsr, RTREE_ZERO, 0);

  183587.       assert( p!=0 );  /* Always returns pCsr->sPoint */

  183588.       pCsr->aNode[0] = pLeaf;

  183589.       p->id = iNode;

  183590.       p->eWithin = PARTLY_WITHIN;

  183591.       rc = nodeRowidIndex(pRtree, pLeaf, iRowid, &iCell);

  183592.       p->iCell = (u8)iCell;

  183593.       RTREE_QUEUE_TRACE(pCsr, "PUSH-F1:");

  183594.     }else{

  183595.       pCsr->atEOF = 1;

  183596.     }

  183597.   }else{

  183598.     /* Normal case - r-tree scan. Set up the RtreeCursor.aConstraint array 

  183599.     ** with the configured constraints. 

  183600.     */

  183601.     rc = nodeAcquire(pRtree, 1, 0, &pRoot);

  183602.     if( rc==SQLITE_OK && argc>0 ){

  183603.       pCsr->aConstraint = sqlite3_malloc64(sizeof(RtreeConstraint)*argc);

  183604.       pCsr->nConstraint = argc;

  183605.       if( !pCsr->aConstraint ){

  183606.         rc = SQLITE_NOMEM;

  183607.       }else{

  183608.         memset(pCsr->aConstraint, 0, sizeof(RtreeConstraint)*argc);

  183609.         memset(pCsr->anQueue, 0, sizeof(u32)*(pRtree->iDepth + 1));

  183610.         assert( (idxStr==0 && argc==0)

  183611.                 || (idxStr && (int)strlen(idxStr)==argc*2) );

  183612.         for(ii=0; ii<argc; ii++){

  183613.           RtreeConstraint *p = &pCsr->aConstraint[ii];

  183614.           p->op = idxStr[ii*2];

  183615.           p->iCoord = idxStr[ii*2+1]-'0';

  183616.           if( p->op>=RTREE_MATCH ){

  183617.             /* A MATCH operator. The right-hand-side must be a blob that

  183618.             ** can be cast into an RtreeMatchArg object. One created using

  183619.             ** an sqlite3_rtree_geometry_callback() SQL user function.

  183620.             */

  183621.             rc = deserializeGeometry(argv[ii], p);

  183622.             if( rc!=SQLITE_OK ){

  183623.               break;

  183624.             }

  183625.             p->pInfo->nCoord = pRtree->nDim2;

  183626.             p->pInfo->anQueue = pCsr->anQueue;

  183627.             p->pInfo->mxLevel = pRtree->iDepth + 1;

  183628.           }else{

  183629. #ifdef SQLITE_RTREE_INT_ONLY

  183630.             p->u.rValue = sqlite3_value_int64(argv[ii]);

  183631. #else

  183632.             p->u.rValue = sqlite3_value_double(argv[ii]);

  183633. #endif

  183634.           }

  183635.         }

  183636.       }

  183637.     }

  183638.     if( rc==SQLITE_OK ){

  183639.       RtreeSearchPoint *pNew;

  183640.       pNew = rtreeSearchPointNew(pCsr, RTREE_ZERO, (u8)(pRtree->iDepth+1));

  183641.       if( pNew==0 ) return SQLITE_NOMEM;

  183642.       pNew->id = 1;

  183643.       pNew->iCell = 0;

  183644.       pNew->eWithin = PARTLY_WITHIN;

  183645.       assert( pCsr->bPoint==1 );

  183646.       pCsr->aNode[0] = pRoot;

  183647.       pRoot = 0;

  183648.       RTREE_QUEUE_TRACE(pCsr, "PUSH-Fm:");

  183649.       rc = rtreeStepToLeaf(pCsr);

  183650.     }

  183651.   }

  183652. 

  183653.   nodeRelease(pRtree, pRoot);

  183654.   rtreeRelease(pRtree);

  183655.   return rc;

  183656. }

  183657. 

  183658. /*

  183659. ** Rtree virtual table module xBestIndex method. There are three

  183660. ** table scan strategies to choose from (in order from most to 

  183661. ** least desirable):

  183662. **

  183663. **   idxNum     idxStr        Strategy

  183664. **   ------------------------------------------------

  183665. **     1        Unused        Direct lookup by rowid.

  183666. **     2        See below     R-tree query or full-table scan.

  183667. **   ------------------------------------------------

  183668. **

  183669. ** If strategy 1 is used, then idxStr is not meaningful. If strategy

  183670. ** 2 is used, idxStr is formatted to contain 2 bytes for each 

  183671. ** constraint used. The first two bytes of idxStr correspond to 

  183672. ** the constraint in sqlite3_index_info.aConstraintUsage[] with

  183673. ** (argvIndex==1) etc.

  183674. **

  183675. ** The first of each pair of bytes in idxStr identifies the constraint

  183676. ** operator as follows:

  183677. **

  183678. **   Operator    Byte Value

  183679. **   ----------------------

  183680. **      =        0x41 ('A')

  183681. **     <=        0x42 ('B')

  183682. **      <        0x43 ('C')

  183683. **     >=        0x44 ('D')

  183684. **      >        0x45 ('E')

  183685. **   MATCH       0x46 ('F')

  183686. **   ----------------------

  183687. **

  183688. ** The second of each pair of bytes identifies the coordinate column

  183689. ** to which the constraint applies. The leftmost coordinate column

  183690. ** is 'a', the second from the left 'b' etc.

  183691. */

  183692. static int rtreeBestIndex(sqlite3_vtab *tab, sqlite3_index_info *pIdxInfo){

  183693.   Rtree *pRtree = (Rtree*)tab;

  183694.   int rc = SQLITE_OK;

  183695.   int ii;

  183696.   int bMatch = 0;                 /* True if there exists a MATCH constraint */

  183697.   i64 nRow;                       /* Estimated rows returned by this scan */

  183698. 

  183699.   int iIdx = 0;

  183700.   char zIdxStr[RTREE_MAX_DIMENSIONS*8+1];

  183701.   memset(zIdxStr, 0, sizeof(zIdxStr));

  183702. 

  183703.   /* Check if there exists a MATCH constraint - even an unusable one. If there

  183704.   ** is, do not consider the lookup-by-rowid plan as using such a plan would

  183705.   ** require the VDBE to evaluate the MATCH constraint, which is not currently

  183706.   ** possible. */

  183707.   for(ii=0; ii<pIdxInfo->nConstraint; ii++){

  183708.     if( pIdxInfo->aConstraint[ii].op==SQLITE_INDEX_CONSTRAINT_MATCH ){

  183709.       bMatch = 1;

  183710.     }

  183711.   }

  183712. 

  183713.   assert( pIdxInfo->idxStr==0 );

  183714.   for(ii=0; ii<pIdxInfo->nConstraint && iIdx<(int)(sizeof(zIdxStr)-1); ii++){

  183715.     struct sqlite3_index_constraint *p = &pIdxInfo->aConstraint[ii];

  183716. 

  183717.     if( bMatch==0 && p->usable 

  183718.      && p->iColumn==0 && p->op==SQLITE_INDEX_CONSTRAINT_EQ 

  183719.     ){

  183720.       /* We have an equality constraint on the rowid. Use strategy 1. */

  183721.       int jj;

  183722.       for(jj=0; jj<ii; jj++){

  183723.         pIdxInfo->aConstraintUsage[jj].argvIndex = 0;

  183724.         pIdxInfo->aConstraintUsage[jj].omit = 0;

  183725.       }

  183726.       pIdxInfo->idxNum = 1;

  183727.       pIdxInfo->aConstraintUsage[ii].argvIndex = 1;

  183728.       pIdxInfo->aConstraintUsage[jj].omit = 1;

  183729. 

  183730.       /* This strategy involves a two rowid lookups on an B-Tree structures

  183731.       ** and then a linear search of an R-Tree node. This should be 

  183732.       ** considered almost as quick as a direct rowid lookup (for which 

  183733.       ** sqlite uses an internal cost of 0.0). It is expected to return

  183734.       ** a single row.

  183735.       */ 

  183736.       pIdxInfo->estimatedCost = 30.0;

  183737.       pIdxInfo->estimatedRows = 1;

  183738.       pIdxInfo->idxFlags = SQLITE_INDEX_SCAN_UNIQUE;

  183739.       return SQLITE_OK;

  183740.     }

  183741. 

  183742.     if( p->usable

  183743.     && ((p->iColumn>0 && p->iColumn<=pRtree->nDim2)

  183744.         || p->op==SQLITE_INDEX_CONSTRAINT_MATCH)

  183745.     ){

  183746.       u8 op;

  183747.       switch( p->op ){

  183748.         case SQLITE_INDEX_CONSTRAINT_EQ:    op = RTREE_EQ;    break;

  183749.         case SQLITE_INDEX_CONSTRAINT_GT:    op = RTREE_GT;    break;

  183750.         case SQLITE_INDEX_CONSTRAINT_LE:    op = RTREE_LE;    break;

  183751.         case SQLITE_INDEX_CONSTRAINT_LT:    op = RTREE_LT;    break;

  183752.         case SQLITE_INDEX_CONSTRAINT_GE:    op = RTREE_GE;    break;

  183753.         case SQLITE_INDEX_CONSTRAINT_MATCH: op = RTREE_MATCH; break;

  183754.         default:                            op = 0;           break;

  183755.       }

  183756.       if( op ){

  183757.         zIdxStr[iIdx++] = op;

  183758.         zIdxStr[iIdx++] = (char)(p->iColumn - 1 + '0');

  183759.         pIdxInfo->aConstraintUsage[ii].argvIndex = (iIdx/2);

  183760.         pIdxInfo->aConstraintUsage[ii].omit = 1;

  183761.       }

  183762.     }

  183763.   }

  183764. 

  183765.   pIdxInfo->idxNum = 2;

  183766.   pIdxInfo->needToFreeIdxStr = 1;

  183767.   if( iIdx>0 && 0==(pIdxInfo->idxStr = sqlite3_mprintf("%s", zIdxStr)) ){

  183768.     return SQLITE_NOMEM;

  183769.   }

  183770. 

  183771.   nRow = pRtree->nRowEst >> (iIdx/2);

  183772.   pIdxInfo->estimatedCost = (double)6.0 * (double)nRow;

  183773.   pIdxInfo->estimatedRows = nRow;

  183774. 

  183775.   return rc;

  183776. }

  183777. 

  183778. /*

  183779. ** Return the N-dimensional volumn of the cell stored in *p.

  183780. */

  183781. static RtreeDValue cellArea(Rtree *pRtree, RtreeCell *p){

  183782.   RtreeDValue area = (RtreeDValue)1;

  183783.   assert( pRtree->nDim>=1 && pRtree->nDim<=5 );

  183784. #ifndef SQLITE_RTREE_INT_ONLY

  183785.   if( pRtree->eCoordType==RTREE_COORD_REAL32 ){

  183786.     switch( pRtree->nDim ){

  183787.       case 5:  area  = p->aCoord[9].f - p->aCoord[8].f;

  183788.       case 4:  area *= p->aCoord[7].f - p->aCoord[6].f;

  183789.       case 3:  area *= p->aCoord[5].f - p->aCoord[4].f;

  183790.       case 2:  area *= p->aCoord[3].f - p->aCoord[2].f;

  183791.       default: area *= p->aCoord[1].f - p->aCoord[0].f;

  183792.     }

  183793.   }else

  183794. #endif

  183795.   {

  183796.     switch( pRtree->nDim ){

  183797.       case 5:  area  = (i64)p->aCoord[9].i - (i64)p->aCoord[8].i;

  183798.       case 4:  area *= (i64)p->aCoord[7].i - (i64)p->aCoord[6].i;

  183799.       case 3:  area *= (i64)p->aCoord[5].i - (i64)p->aCoord[4].i;

  183800.       case 2:  area *= (i64)p->aCoord[3].i - (i64)p->aCoord[2].i;

  183801.       default: area *= (i64)p->aCoord[1].i - (i64)p->aCoord[0].i;

  183802.     }

  183803.   }

  183804.   return area;

  183805. }

  183806. 

  183807. /*

  183808. ** Return the margin length of cell p. The margin length is the sum

  183809. ** of the objects size in each dimension.

  183810. */

  183811. static RtreeDValue cellMargin(Rtree *pRtree, RtreeCell *p){

  183812.   RtreeDValue margin = 0;

  183813.   int ii = pRtree->nDim2 - 2;

  183814.   do{

  183815.     margin += (DCOORD(p->aCoord[ii+1]) - DCOORD(p->aCoord[ii]));

  183816.     ii -= 2;

  183817.   }while( ii>=0 );

  183818.   return margin;

  183819. }

  183820. 

  183821. /*

  183822. ** Store the union of cells p1 and p2 in p1.

  183823. */

  183824. static void cellUnion(Rtree *pRtree, RtreeCell *p1, RtreeCell *p2){

  183825.   int ii = 0;

  183826.   if( pRtree->eCoordType==RTREE_COORD_REAL32 ){

  183827.     do{

  183828.       p1->aCoord[ii].f = MIN(p1->aCoord[ii].f, p2->aCoord[ii].f);

  183829.       p1->aCoord[ii+1].f = MAX(p1->aCoord[ii+1].f, p2->aCoord[ii+1].f);

  183830.       ii += 2;

  183831.     }while( ii<pRtree->nDim2 );

  183832.   }else{

  183833.     do{

  183834.       p1->aCoord[ii].i = MIN(p1->aCoord[ii].i, p2->aCoord[ii].i);

  183835.       p1->aCoord[ii+1].i = MAX(p1->aCoord[ii+1].i, p2->aCoord[ii+1].i);

  183836.       ii += 2;

  183837.     }while( ii<pRtree->nDim2 );

  183838.   }

  183839. }

  183840. 

  183841. /*

  183842. ** Return true if the area covered by p2 is a subset of the area covered

  183843. ** by p1. False otherwise.

  183844. */

  183845. static int cellContains(Rtree *pRtree, RtreeCell *p1, RtreeCell *p2){

  183846.   int ii;

  183847.   int isInt = (pRtree->eCoordType==RTREE_COORD_INT32);

  183848.   for(ii=0; ii<pRtree->nDim2; ii+=2){

  183849.     RtreeCoord *a1 = &p1->aCoord[ii];

  183850.     RtreeCoord *a2 = &p2->aCoord[ii];

  183851.     if( (!isInt && (a2[0].f<a1[0].f || a2[1].f>a1[1].f)) 

  183852.      || ( isInt && (a2[0].i<a1[0].i || a2[1].i>a1[1].i)) 

  183853.     ){

  183854.       return 0;

  183855.     }

  183856.   }

  183857.   return 1;

  183858. }

  183859. 

  183860. /*

  183861. ** Return the amount cell p would grow by if it were unioned with pCell.

  183862. */

  183863. static RtreeDValue cellGrowth(Rtree *pRtree, RtreeCell *p, RtreeCell *pCell){

  183864.   RtreeDValue area;

  183865.   RtreeCell cell;

  183866.   memcpy(&cell, p, sizeof(RtreeCell));

  183867.   area = cellArea(pRtree, &cell);

  183868.   cellUnion(pRtree, &cell, pCell);

  183869.   return (cellArea(pRtree, &cell)-area);

  183870. }

  183871. 

  183872. static RtreeDValue cellOverlap(

  183873.   Rtree *pRtree, 

  183874.   RtreeCell *p, 

  183875.   RtreeCell *aCell, 

  183876.   int nCell

  183877. ){

  183878.   int ii;

  183879.   RtreeDValue overlap = RTREE_ZERO;

  183880.   for(ii=0; ii<nCell; ii++){

  183881.     int jj;

  183882.     RtreeDValue o = (RtreeDValue)1;

  183883.     for(jj=0; jj<pRtree->nDim2; jj+=2){

  183884.       RtreeDValue x1, x2;

  183885.       x1 = MAX(DCOORD(p->aCoord[jj]), DCOORD(aCell[ii].aCoord[jj]));

  183886.       x2 = MIN(DCOORD(p->aCoord[jj+1]), DCOORD(aCell[ii].aCoord[jj+1]));

  183887.       if( x2<x1 ){

  183888.         o = (RtreeDValue)0;

  183889.         break;

  183890.       }else{

  183891.         o = o * (x2-x1);

  183892.       }

  183893.     }

  183894.     overlap += o;

  183895.   }

  183896.   return overlap;

  183897. }

  183898. 

  183899. 

  183900. /*

  183901. ** This function implements the ChooseLeaf algorithm from Gutman[84].

  183902. ** ChooseSubTree in r*tree terminology.

  183903. */

  183904. static int ChooseLeaf(

  183905.   Rtree *pRtree,               /* Rtree table */

  183906.   RtreeCell *pCell,            /* Cell to insert into rtree */

  183907.   int iHeight,                 /* Height of sub-tree rooted at pCell */

  183908.   RtreeNode **ppLeaf           /* OUT: Selected leaf page */

  183909. ){

  183910.   int rc;

  183911.   int ii;

  183912.   RtreeNode *pNode = 0;

  183913.   rc = nodeAcquire(pRtree, 1, 0, &pNode);

  183914. 

  183915.   for(ii=0; rc==SQLITE_OK && ii<(pRtree->iDepth-iHeight); ii++){

  183916.     int iCell;

  183917.     sqlite3_int64 iBest = 0;

  183918. 

  183919.     RtreeDValue fMinGrowth = RTREE_ZERO;

  183920.     RtreeDValue fMinArea = RTREE_ZERO;

  183921. 

  183922.     int nCell = NCELL(pNode);

  183923.     RtreeCell cell;

  183924.     RtreeNode *pChild;

  183925. 

  183926.     RtreeCell *aCell = 0;

  183927. 

  183928.     /* Select the child node which will be enlarged the least if pCell

  183929.     ** is inserted into it. Resolve ties by choosing the entry with

  183930.     ** the smallest area.

  183931.     */

  183932.     for(iCell=0; iCell<nCell; iCell++){

  183933.       int bBest = 0;

  183934.       RtreeDValue growth;

  183935.       RtreeDValue area;

  183936.       nodeGetCell(pRtree, pNode, iCell, &cell);

  183937.       growth = cellGrowth(pRtree, &cell, pCell);

  183938.       area = cellArea(pRtree, &cell);

  183939.       if( iCell==0||growth<fMinGrowth||(growth==fMinGrowth && area<fMinArea) ){

  183940.         bBest = 1;

  183941.       }

  183942.       if( bBest ){

  183943.         fMinGrowth = growth;

  183944.         fMinArea = area;

  183945.         iBest = cell.iRowid;

  183946.       }

  183947.     }

  183948. 

  183949.     sqlite3_free(aCell);

  183950.     rc = nodeAcquire(pRtree, iBest, pNode, &pChild);

  183951.     nodeRelease(pRtree, pNode);

  183952.     pNode = pChild;

  183953.   }

  183954. 

  183955.   *ppLeaf = pNode;

  183956.   return rc;

  183957. }

  183958. 

  183959. /*

  183960. ** A cell with the same content as pCell has just been inserted into

  183961. ** the node pNode. This function updates the bounding box cells in

  183962. ** all ancestor elements.

  183963. */

  183964. static int AdjustTree(

  183965.   Rtree *pRtree,                    /* Rtree table */

  183966.   RtreeNode *pNode,                 /* Adjust ancestry of this node. */

  183967.   RtreeCell *pCell                  /* This cell was just inserted */

  183968. ){

  183969.   RtreeNode *p = pNode;

  183970.   int cnt = 0;

  183971.   while( p->pParent ){

  183972.     RtreeNode *pParent = p->pParent;

  183973.     RtreeCell cell;

  183974.     int iCell;

  183975. 

  183976.     if( (++cnt)>1000 || nodeParentIndex(pRtree, p, &iCell)  ){

  183977.       RTREE_IS_CORRUPT(pRtree);

  183978.       return SQLITE_CORRUPT_VTAB;

  183979.     }

  183980. 

  183981.     nodeGetCell(pRtree, pParent, iCell, &cell);

  183982.     if( !cellContains(pRtree, &cell, pCell) ){

  183983.       cellUnion(pRtree, &cell, pCell);

  183984.       nodeOverwriteCell(pRtree, pParent, &cell, iCell);

  183985.     }

  183986.  

  183987.     p = pParent;

  183988.   }

  183989.   return SQLITE_OK;

  183990. }

  183991. 

  183992. /*

  183993. ** Write mapping (iRowid->iNode) to the <rtree>_rowid table.

  183994. */

  183995. static int rowidWrite(Rtree *pRtree, sqlite3_int64 iRowid, sqlite3_int64 iNode){

  183996.   sqlite3_bind_int64(pRtree->pWriteRowid, 1, iRowid);

  183997.   sqlite3_bind_int64(pRtree->pWriteRowid, 2, iNode);

  183998.   sqlite3_step(pRtree->pWriteRowid);

  183999.   return sqlite3_reset(pRtree->pWriteRowid);

  184000. }

  184001. 

  184002. /*

  184003. ** Write mapping (iNode->iPar) to the <rtree>_parent table.

  184004. */

  184005. static int parentWrite(Rtree *pRtree, sqlite3_int64 iNode, sqlite3_int64 iPar){

  184006.   sqlite3_bind_int64(pRtree->pWriteParent, 1, iNode);

  184007.   sqlite3_bind_int64(pRtree->pWriteParent, 2, iPar);

  184008.   sqlite3_step(pRtree->pWriteParent);

  184009.   return sqlite3_reset(pRtree->pWriteParent);

  184010. }

  184011. 

  184012. static int rtreeInsertCell(Rtree *, RtreeNode *, RtreeCell *, int);

  184013. 

  184014. 

  184015. /*

  184016. ** Arguments aIdx, aDistance and aSpare all point to arrays of size

  184017. ** nIdx. The aIdx array contains the set of integers from 0 to 

  184018. ** (nIdx-1) in no particular order. This function sorts the values

  184019. ** in aIdx according to the indexed values in aDistance. For

  184020. ** example, assuming the inputs:

  184021. **

  184022. **   aIdx      = { 0,   1,   2,   3 }

  184023. **   aDistance = { 5.0, 2.0, 7.0, 6.0 }

  184024. **

  184025. ** this function sets the aIdx array to contain:

  184026. **

  184027. **   aIdx      = { 0,   1,   2,   3 }

  184028. **

  184029. ** The aSpare array is used as temporary working space by the

  184030. ** sorting algorithm.

  184031. */

  184032. static void SortByDistance(

  184033.   int *aIdx, 

  184034.   int nIdx, 

  184035.   RtreeDValue *aDistance, 

  184036.   int *aSpare

  184037. ){

  184038.   if( nIdx>1 ){

  184039.     int iLeft = 0;

  184040.     int iRight = 0;

  184041. 

  184042.     int nLeft = nIdx/2;

  184043.     int nRight = nIdx-nLeft;

  184044.     int *aLeft = aIdx;

  184045.     int *aRight = &aIdx[nLeft];

  184046. 

  184047.     SortByDistance(aLeft, nLeft, aDistance, aSpare);

  184048.     SortByDistance(aRight, nRight, aDistance, aSpare);

  184049. 

  184050.     memcpy(aSpare, aLeft, sizeof(int)*nLeft);

  184051.     aLeft = aSpare;

  184052. 

  184053.     while( iLeft<nLeft || iRight<nRight ){

  184054.       if( iLeft==nLeft ){

  184055.         aIdx[iLeft+iRight] = aRight[iRight];

  184056.         iRight++;

  184057.       }else if( iRight==nRight ){

  184058.         aIdx[iLeft+iRight] = aLeft[iLeft];

  184059.         iLeft++;

  184060.       }else{

  184061.         RtreeDValue fLeft = aDistance[aLeft[iLeft]];

  184062.         RtreeDValue fRight = aDistance[aRight[iRight]];

  184063.         if( fLeft<fRight ){

  184064.           aIdx[iLeft+iRight] = aLeft[iLeft];

  184065.           iLeft++;

  184066.         }else{

  184067.           aIdx[iLeft+iRight] = aRight[iRight];

  184068.           iRight++;

  184069.         }

  184070.       }

  184071.     }

  184072. 

  184073. #if 0

  184074.     /* Check that the sort worked */

  184075.     {

  184076.       int jj;

  184077.       for(jj=1; jj<nIdx; jj++){

  184078.         RtreeDValue left = aDistance[aIdx[jj-1]];

  184079.         RtreeDValue right = aDistance[aIdx[jj]];

  184080.         assert( left<=right );

  184081.       }

  184082.     }

  184083. #endif

  184084.   }

  184085. }

  184086. 

  184087. /*

  184088. ** Arguments aIdx, aCell and aSpare all point to arrays of size

  184089. ** nIdx. The aIdx array contains the set of integers from 0 to 

  184090. ** (nIdx-1) in no particular order. This function sorts the values

  184091. ** in aIdx according to dimension iDim of the cells in aCell. The

  184092. ** minimum value of dimension iDim is considered first, the

  184093. ** maximum used to break ties.

  184094. **

  184095. ** The aSpare array is used as temporary working space by the

  184096. ** sorting algorithm.

  184097. */

  184098. static void SortByDimension(

  184099.   Rtree *pRtree,

  184100.   int *aIdx, 

  184101.   int nIdx, 

  184102.   int iDim, 

  184103.   RtreeCell *aCell, 

  184104.   int *aSpare

  184105. ){

  184106.   if( nIdx>1 ){

  184107. 

  184108.     int iLeft = 0;

  184109.     int iRight = 0;

  184110. 

  184111.     int nLeft = nIdx/2;

  184112.     int nRight = nIdx-nLeft;

  184113.     int *aLeft = aIdx;

  184114.     int *aRight = &aIdx[nLeft];

  184115. 

  184116.     SortByDimension(pRtree, aLeft, nLeft, iDim, aCell, aSpare);

  184117.     SortByDimension(pRtree, aRight, nRight, iDim, aCell, aSpare);

  184118. 

  184119.     memcpy(aSpare, aLeft, sizeof(int)*nLeft);

  184120.     aLeft = aSpare;

  184121.     while( iLeft<nLeft || iRight<nRight ){

  184122.       RtreeDValue xleft1 = DCOORD(aCell[aLeft[iLeft]].aCoord[iDim*2]);

  184123.       RtreeDValue xleft2 = DCOORD(aCell[aLeft[iLeft]].aCoord[iDim*2+1]);

  184124.       RtreeDValue xright1 = DCOORD(aCell[aRight[iRight]].aCoord[iDim*2]);

  184125.       RtreeDValue xright2 = DCOORD(aCell[aRight[iRight]].aCoord[iDim*2+1]);

  184126.       if( (iLeft!=nLeft) && ((iRight==nRight)

  184127.        || (xleft1<xright1)

  184128.        || (xleft1==xright1 && xleft2<xright2)

  184129.       )){

  184130.         aIdx[iLeft+iRight] = aLeft[iLeft];

  184131.         iLeft++;

  184132.       }else{

  184133.         aIdx[iLeft+iRight] = aRight[iRight];

  184134.         iRight++;

  184135.       }

  184136.     }

  184137. 

  184138. #if 0

  184139.     /* Check that the sort worked */

  184140.     {

  184141.       int jj;

  184142.       for(jj=1; jj<nIdx; jj++){

  184143.         RtreeDValue xleft1 = aCell[aIdx[jj-1]].aCoord[iDim*2];

  184144.         RtreeDValue xleft2 = aCell[aIdx[jj-1]].aCoord[iDim*2+1];

  184145.         RtreeDValue xright1 = aCell[aIdx[jj]].aCoord[iDim*2];

  184146.         RtreeDValue xright2 = aCell[aIdx[jj]].aCoord[iDim*2+1];

  184147.         assert( xleft1<=xright1 && (xleft1<xright1 || xleft2<=xright2) );

  184148.       }

  184149.     }

  184150. #endif

  184151.   }

  184152. }

  184153. 

  184154. /*

  184155. ** Implementation of the R*-tree variant of SplitNode from Beckman[1990].

  184156. */

  184157. static int splitNodeStartree(

  184158.   Rtree *pRtree,

  184159.   RtreeCell *aCell,

  184160.   int nCell,

  184161.   RtreeNode *pLeft,

  184162.   RtreeNode *pRight,

  184163.   RtreeCell *pBboxLeft,

  184164.   RtreeCell *pBboxRight

  184165. ){

  184166.   int **aaSorted;

  184167.   int *aSpare;

  184168.   int ii;

  184169. 

  184170.   int iBestDim = 0;

  184171.   int iBestSplit = 0;

  184172.   RtreeDValue fBestMargin = RTREE_ZERO;

  184173. 

  184174.   sqlite3_int64 nByte = (pRtree->nDim+1)*(sizeof(int*)+nCell*sizeof(int));

  184175. 

  184176.   aaSorted = (int **)sqlite3_malloc64(nByte);

  184177.   if( !aaSorted ){

  184178.     return SQLITE_NOMEM;

  184179.   }

  184180. 

  184181.   aSpare = &((int *)&aaSorted[pRtree->nDim])[pRtree->nDim*nCell];

  184182.   memset(aaSorted, 0, nByte);

  184183.   for(ii=0; ii<pRtree->nDim; ii++){

  184184.     int jj;

  184185.     aaSorted[ii] = &((int *)&aaSorted[pRtree->nDim])[ii*nCell];

  184186.     for(jj=0; jj<nCell; jj++){

  184187.       aaSorted[ii][jj] = jj;

  184188.     }

  184189.     SortByDimension(pRtree, aaSorted[ii], nCell, ii, aCell, aSpare);

  184190.   }

  184191. 

  184192.   for(ii=0; ii<pRtree->nDim; ii++){

  184193.     RtreeDValue margin = RTREE_ZERO;

  184194.     RtreeDValue fBestOverlap = RTREE_ZERO;

  184195.     RtreeDValue fBestArea = RTREE_ZERO;

  184196.     int iBestLeft = 0;

  184197.     int nLeft;

  184198. 

  184199.     for(

  184200.       nLeft=RTREE_MINCELLS(pRtree); 

  184201.       nLeft<=(nCell-RTREE_MINCELLS(pRtree)); 

  184202.       nLeft++

  184203.     ){

  184204.       RtreeCell left;

  184205.       RtreeCell right;

  184206.       int kk;

  184207.       RtreeDValue overlap;

  184208.       RtreeDValue area;

  184209. 

  184210.       memcpy(&left, &aCell[aaSorted[ii][0]], sizeof(RtreeCell));

  184211.       memcpy(&right, &aCell[aaSorted[ii][nCell-1]], sizeof(RtreeCell));

  184212.       for(kk=1; kk<(nCell-1); kk++){

  184213.         if( kk<nLeft ){

  184214.           cellUnion(pRtree, &left, &aCell[aaSorted[ii][kk]]);

  184215.         }else{

  184216.           cellUnion(pRtree, &right, &aCell[aaSorted[ii][kk]]);

  184217.         }

  184218.       }

  184219.       margin += cellMargin(pRtree, &left);

  184220.       margin += cellMargin(pRtree, &right);

  184221.       overlap = cellOverlap(pRtree, &left, &right, 1);

  184222.       area = cellArea(pRtree, &left) + cellArea(pRtree, &right);

  184223.       if( (nLeft==RTREE_MINCELLS(pRtree))

  184224.        || (overlap<fBestOverlap)

  184225.        || (overlap==fBestOverlap && area<fBestArea)

  184226.       ){

  184227.         iBestLeft = nLeft;

  184228.         fBestOverlap = overlap;

  184229.         fBestArea = area;

  184230.       }

  184231.     }

  184232. 

  184233.     if( ii==0 || margin<fBestMargin ){

  184234.       iBestDim = ii;

  184235.       fBestMargin = margin;

  184236.       iBestSplit = iBestLeft;

  184237.     }

  184238.   }

  184239. 

  184240.   memcpy(pBboxLeft, &aCell[aaSorted[iBestDim][0]], sizeof(RtreeCell));

  184241.   memcpy(pBboxRight, &aCell[aaSorted[iBestDim][iBestSplit]], sizeof(RtreeCell));

  184242.   for(ii=0; ii<nCell; ii++){

  184243.     RtreeNode *pTarget = (ii<iBestSplit)?pLeft:pRight;

  184244.     RtreeCell *pBbox = (ii<iBestSplit)?pBboxLeft:pBboxRight;

  184245.     RtreeCell *pCell = &aCell[aaSorted[iBestDim][ii]];

  184246.     nodeInsertCell(pRtree, pTarget, pCell);

  184247.     cellUnion(pRtree, pBbox, pCell);

  184248.   }

  184249. 

  184250.   sqlite3_free(aaSorted);

  184251.   return SQLITE_OK;

  184252. }

  184253. 

  184254. 

  184255. static int updateMapping(

  184256.   Rtree *pRtree, 

  184257.   i64 iRowid, 

  184258.   RtreeNode *pNode, 

  184259.   int iHeight

  184260. ){

  184261.   int (*xSetMapping)(Rtree *, sqlite3_int64, sqlite3_int64);

  184262.   xSetMapping = ((iHeight==0)?rowidWrite:parentWrite);

  184263.   if( iHeight>0 ){

  184264.     RtreeNode *pChild = nodeHashLookup(pRtree, iRowid);

  184265.     if( pChild ){

  184266.       nodeRelease(pRtree, pChild->pParent);

  184267.       nodeReference(pNode);

  184268.       pChild->pParent = pNode;

  184269.     }

  184270.   }

  184271.   return xSetMapping(pRtree, iRowid, pNode->iNode);

  184272. }

  184273. 

  184274. static int SplitNode(

  184275.   Rtree *pRtree,

  184276.   RtreeNode *pNode,

  184277.   RtreeCell *pCell,

  184278.   int iHeight

  184279. ){

  184280.   int i;

  184281.   int newCellIsRight = 0;

  184282. 

  184283.   int rc = SQLITE_OK;

  184284.   int nCell = NCELL(pNode);

  184285.   RtreeCell *aCell;

  184286.   int *aiUsed;

  184287. 

  184288.   RtreeNode *pLeft = 0;

  184289.   RtreeNode *pRight = 0;

  184290. 

  184291.   RtreeCell leftbbox;

  184292.   RtreeCell rightbbox;

  184293. 

  184294.   /* Allocate an array and populate it with a copy of pCell and 

  184295.   ** all cells from node pLeft. Then zero the original node.

  184296.   */

  184297.   aCell = sqlite3_malloc64((sizeof(RtreeCell)+sizeof(int))*(nCell+1));

  184298.   if( !aCell ){

  184299.     rc = SQLITE_NOMEM;

  184300.     goto splitnode_out;

  184301.   }

  184302.   aiUsed = (int *)&aCell[nCell+1];

  184303.   memset(aiUsed, 0, sizeof(int)*(nCell+1));

  184304.   for(i=0; i<nCell; i++){

  184305.     nodeGetCell(pRtree, pNode, i, &aCell[i]);

  184306.   }

  184307.   nodeZero(pRtree, pNode);

  184308.   memcpy(&aCell[nCell], pCell, sizeof(RtreeCell));

  184309.   nCell++;

  184310. 

  184311.   if( pNode->iNode==1 ){

  184312.     pRight = nodeNew(pRtree, pNode);

  184313.     pLeft = nodeNew(pRtree, pNode);

  184314.     pRtree->iDepth++;

  184315.     pNode->isDirty = 1;

  184316.     writeInt16(pNode->zData, pRtree->iDepth);

  184317.   }else{

  184318.     pLeft = pNode;

  184319.     pRight = nodeNew(pRtree, pLeft->pParent);

  184320.     pLeft->nRef++;

  184321.   }

  184322. 

  184323.   if( !pLeft || !pRight ){

  184324.     rc = SQLITE_NOMEM;

  184325.     goto splitnode_out;

  184326.   }

  184327. 

  184328.   memset(pLeft->zData, 0, pRtree->iNodeSize);

  184329.   memset(pRight->zData, 0, pRtree->iNodeSize);

  184330. 

  184331.   rc = splitNodeStartree(pRtree, aCell, nCell, pLeft, pRight,

  184332.                          &leftbbox, &rightbbox);

  184333.   if( rc!=SQLITE_OK ){

  184334.     goto splitnode_out;

  184335.   }

  184336. 

  184337.   /* Ensure both child nodes have node numbers assigned to them by calling

  184338.   ** nodeWrite(). Node pRight always needs a node number, as it was created

  184339.   ** by nodeNew() above. But node pLeft sometimes already has a node number.

  184340.   ** In this case avoid the all to nodeWrite().

  184341.   */

  184342.   if( SQLITE_OK!=(rc = nodeWrite(pRtree, pRight))

  184343.    || (0==pLeft->iNode && SQLITE_OK!=(rc = nodeWrite(pRtree, pLeft)))

  184344.   ){

  184345.     goto splitnode_out;

  184346.   }

  184347. 

  184348.   rightbbox.iRowid = pRight->iNode;

  184349.   leftbbox.iRowid = pLeft->iNode;

  184350. 

  184351.   if( pNode->iNode==1 ){

  184352.     rc = rtreeInsertCell(pRtree, pLeft->pParent, &leftbbox, iHeight+1);

  184353.     if( rc!=SQLITE_OK ){

  184354.       goto splitnode_out;

  184355.     }

  184356.   }else{

  184357.     RtreeNode *pParent = pLeft->pParent;

  184358.     int iCell;

  184359.     rc = nodeParentIndex(pRtree, pLeft, &iCell);

  184360.     if( rc==SQLITE_OK ){

  184361.       nodeOverwriteCell(pRtree, pParent, &leftbbox, iCell);

  184362.       rc = AdjustTree(pRtree, pParent, &leftbbox);

  184363.     }

  184364.     if( rc!=SQLITE_OK ){

  184365.       goto splitnode_out;

  184366.     }

  184367.   }

  184368.   if( (rc = rtreeInsertCell(pRtree, pRight->pParent, &rightbbox, iHeight+1)) ){

  184369.     goto splitnode_out;

  184370.   }

  184371. 

  184372.   for(i=0; i<NCELL(pRight); i++){

  184373.     i64 iRowid = nodeGetRowid(pRtree, pRight, i);

  184374.     rc = updateMapping(pRtree, iRowid, pRight, iHeight);

  184375.     if( iRowid==pCell->iRowid ){

  184376.       newCellIsRight = 1;

  184377.     }

  184378.     if( rc!=SQLITE_OK ){

  184379.       goto splitnode_out;

  184380.     }

  184381.   }

  184382.   if( pNode->iNode==1 ){

  184383.     for(i=0; i<NCELL(pLeft); i++){

  184384.       i64 iRowid = nodeGetRowid(pRtree, pLeft, i);

  184385.       rc = updateMapping(pRtree, iRowid, pLeft, iHeight);

  184386.       if( rc!=SQLITE_OK ){

  184387.         goto splitnode_out;

  184388.       }

  184389.     }

  184390.   }else if( newCellIsRight==0 ){

  184391.     rc = updateMapping(pRtree, pCell->iRowid, pLeft, iHeight);

  184392.   }

  184393. 

  184394.   if( rc==SQLITE_OK ){

  184395.     rc = nodeRelease(pRtree, pRight);

  184396.     pRight = 0;

  184397.   }

  184398.   if( rc==SQLITE_OK ){

  184399.     rc = nodeRelease(pRtree, pLeft);

  184400.     pLeft = 0;

  184401.   }

  184402. 

  184403. splitnode_out:

  184404.   nodeRelease(pRtree, pRight);

  184405.   nodeRelease(pRtree, pLeft);

  184406.   sqlite3_free(aCell);

  184407.   return rc;

  184408. }

  184409. 

  184410. /*

  184411. ** If node pLeaf is not the root of the r-tree and its pParent pointer is 

  184412. ** still NULL, load all ancestor nodes of pLeaf into memory and populate

  184413. ** the pLeaf->pParent chain all the way up to the root node.

  184414. **

  184415. ** This operation is required when a row is deleted (or updated - an update

  184416. ** is implemented as a delete followed by an insert). SQLite provides the

  184417. ** rowid of the row to delete, which can be used to find the leaf on which

  184418. ** the entry resides (argument pLeaf). Once the leaf is located, this 

  184419. ** function is called to determine its ancestry.

  184420. */

  184421. static int fixLeafParent(Rtree *pRtree, RtreeNode *pLeaf){

  184422.   int rc = SQLITE_OK;

  184423.   RtreeNode *pChild = pLeaf;

  184424.   while( rc==SQLITE_OK && pChild->iNode!=1 && pChild->pParent==0 ){

  184425.     int rc2 = SQLITE_OK;          /* sqlite3_reset() return code */

  184426.     sqlite3_bind_int64(pRtree->pReadParent, 1, pChild->iNode);

  184427.     rc = sqlite3_step(pRtree->pReadParent);

  184428.     if( rc==SQLITE_ROW ){

  184429.       RtreeNode *pTest;           /* Used to test for reference loops */

  184430.       i64 iNode;                  /* Node number of parent node */

  184431. 

  184432.       /* Before setting pChild->pParent, test that we are not creating a

  184433.       ** loop of references (as we would if, say, pChild==pParent). We don't

  184434.       ** want to do this as it leads to a memory leak when trying to delete

  184435.       ** the referenced counted node structures.

  184436.       */

  184437.       iNode = sqlite3_column_int64(pRtree->pReadParent, 0);

  184438.       for(pTest=pLeaf; pTest && pTest->iNode!=iNode; pTest=pTest->pParent);

  184439.       if( !pTest ){

  184440.         rc2 = nodeAcquire(pRtree, iNode, 0, &pChild->pParent);

  184441.       }

  184442.     }

  184443.     rc = sqlite3_reset(pRtree->pReadParent);

  184444.     if( rc==SQLITE_OK ) rc = rc2;

  184445.     if( rc==SQLITE_OK && !pChild->pParent ){

  184446.       RTREE_IS_CORRUPT(pRtree);

  184447.       rc = SQLITE_CORRUPT_VTAB;

  184448.     }

  184449.     pChild = pChild->pParent;

  184450.   }

  184451.   return rc;

  184452. }

  184453. 

  184454. static int deleteCell(Rtree *, RtreeNode *, int, int);

  184455. 

  184456. static int removeNode(Rtree *pRtree, RtreeNode *pNode, int iHeight){

  184457.   int rc;

  184458.   int rc2;

  184459.   RtreeNode *pParent = 0;

  184460.   int iCell;

  184461. 

  184462.   assert( pNode->nRef==1 );

  184463. 

  184464.   /* Remove the entry in the parent cell. */

  184465.   rc = nodeParentIndex(pRtree, pNode, &iCell);

  184466.   if( rc==SQLITE_OK ){

  184467.     pParent = pNode->pParent;

  184468.     pNode->pParent = 0;

  184469.     rc = deleteCell(pRtree, pParent, iCell, iHeight+1);

  184470.   }

  184471.   rc2 = nodeRelease(pRtree, pParent);

  184472.   if( rc==SQLITE_OK ){

  184473.     rc = rc2;

  184474.   }

  184475.   if( rc!=SQLITE_OK ){

  184476.     return rc;

  184477.   }

  184478. 

  184479.   /* Remove the xxx_node entry. */

  184480.   sqlite3_bind_int64(pRtree->pDeleteNode, 1, pNode->iNode);

  184481.   sqlite3_step(pRtree->pDeleteNode);

  184482.   if( SQLITE_OK!=(rc = sqlite3_reset(pRtree->pDeleteNode)) ){

  184483.     return rc;

  184484.   }

  184485. 

  184486.   /* Remove the xxx_parent entry. */

  184487.   sqlite3_bind_int64(pRtree->pDeleteParent, 1, pNode->iNode);

  184488.   sqlite3_step(pRtree->pDeleteParent);

  184489.   if( SQLITE_OK!=(rc = sqlite3_reset(pRtree->pDeleteParent)) ){

  184490.     return rc;

  184491.   }

  184492.   

  184493.   /* Remove the node from the in-memory hash table and link it into

  184494.   ** the Rtree.pDeleted list. Its contents will be re-inserted later on.

  184495.   */

  184496.   nodeHashDelete(pRtree, pNode);

  184497.   pNode->iNode = iHeight;

  184498.   pNode->pNext = pRtree->pDeleted;

  184499.   pNode->nRef++;

  184500.   pRtree->pDeleted = pNode;

  184501. 

  184502.   return SQLITE_OK;

  184503. }

  184504. 

  184505. static int fixBoundingBox(Rtree *pRtree, RtreeNode *pNode){

  184506.   RtreeNode *pParent = pNode->pParent;

  184507.   int rc = SQLITE_OK; 

  184508.   if( pParent ){

  184509.     int ii; 

  184510.     int nCell = NCELL(pNode);

  184511.     RtreeCell box;                            /* Bounding box for pNode */

  184512.     nodeGetCell(pRtree, pNode, 0, &box);

  184513.     for(ii=1; ii<nCell; ii++){

  184514.       RtreeCell cell;

  184515.       nodeGetCell(pRtree, pNode, ii, &cell);

  184516.       cellUnion(pRtree, &box, &cell);

  184517.     }

  184518.     box.iRowid = pNode->iNode;

  184519.     rc = nodeParentIndex(pRtree, pNode, &ii);

  184520.     if( rc==SQLITE_OK ){

  184521.       nodeOverwriteCell(pRtree, pParent, &box, ii);

  184522.       rc = fixBoundingBox(pRtree, pParent);

  184523.     }

  184524.   }

  184525.   return rc;

  184526. }

  184527. 

  184528. /*

  184529. ** Delete the cell at index iCell of node pNode. After removing the

  184530. ** cell, adjust the r-tree data structure if required.

  184531. */

  184532. static int deleteCell(Rtree *pRtree, RtreeNode *pNode, int iCell, int iHeight){

  184533.   RtreeNode *pParent;

  184534.   int rc;

  184535. 

  184536.   if( SQLITE_OK!=(rc = fixLeafParent(pRtree, pNode)) ){

  184537.     return rc;

  184538.   }

  184539. 

  184540.   /* Remove the cell from the node. This call just moves bytes around

  184541.   ** the in-memory node image, so it cannot fail.

  184542.   */

  184543.   nodeDeleteCell(pRtree, pNode, iCell);

  184544. 

  184545.   /* If the node is not the tree root and now has less than the minimum

  184546.   ** number of cells, remove it from the tree. Otherwise, update the

  184547.   ** cell in the parent node so that it tightly contains the updated

  184548.   ** node.

  184549.   */

  184550.   pParent = pNode->pParent;

  184551.   assert( pParent || pNode->iNode==1 );

  184552.   if( pParent ){

  184553.     if( NCELL(pNode)<RTREE_MINCELLS(pRtree) ){

  184554.       rc = removeNode(pRtree, pNode, iHeight);

  184555.     }else{

  184556.       rc = fixBoundingBox(pRtree, pNode);

  184557.     }

  184558.   }

  184559. 

  184560.   return rc;

  184561. }

  184562. 

  184563. static int Reinsert(

  184564.   Rtree *pRtree, 

  184565.   RtreeNode *pNode, 

  184566.   RtreeCell *pCell, 

  184567.   int iHeight

  184568. ){

  184569.   int *aOrder;

  184570.   int *aSpare;

  184571.   RtreeCell *aCell;

  184572.   RtreeDValue *aDistance;

  184573.   int nCell;

  184574.   RtreeDValue aCenterCoord[RTREE_MAX_DIMENSIONS];

  184575.   int iDim;

  184576.   int ii;

  184577.   int rc = SQLITE_OK;

  184578.   int n;

  184579. 

  184580.   memset(aCenterCoord, 0, sizeof(RtreeDValue)*RTREE_MAX_DIMENSIONS);

  184581. 

  184582.   nCell = NCELL(pNode)+1;

  184583.   n = (nCell+1)&(~1);

  184584. 

  184585.   /* Allocate the buffers used by this operation. The allocation is

  184586.   ** relinquished before this function returns.

  184587.   */

  184588.   aCell = (RtreeCell *)sqlite3_malloc64(n * (

  184589.     sizeof(RtreeCell)     +         /* aCell array */

  184590.     sizeof(int)           +         /* aOrder array */

  184591.     sizeof(int)           +         /* aSpare array */

  184592.     sizeof(RtreeDValue)             /* aDistance array */

  184593.   ));

  184594.   if( !aCell ){

  184595.     return SQLITE_NOMEM;

  184596.   }

  184597.   aOrder    = (int *)&aCell[n];

  184598.   aSpare    = (int *)&aOrder[n];

  184599.   aDistance = (RtreeDValue *)&aSpare[n];

  184600. 

  184601.   for(ii=0; ii<nCell; ii++){

  184602.     if( ii==(nCell-1) ){

  184603.       memcpy(&aCell[ii], pCell, sizeof(RtreeCell));

  184604.     }else{

  184605.       nodeGetCell(pRtree, pNode, ii, &aCell[ii]);

  184606.     }

  184607.     aOrder[ii] = ii;

  184608.     for(iDim=0; iDim<pRtree->nDim; iDim++){

  184609.       aCenterCoord[iDim] += DCOORD(aCell[ii].aCoord[iDim*2]);

  184610.       aCenterCoord[iDim] += DCOORD(aCell[ii].aCoord[iDim*2+1]);

  184611.     }

  184612.   }

  184613.   for(iDim=0; iDim<pRtree->nDim; iDim++){

  184614.     aCenterCoord[iDim] = (aCenterCoord[iDim]/(nCell*(RtreeDValue)2));

  184615.   }

  184616. 

  184617.   for(ii=0; ii<nCell; ii++){

  184618.     aDistance[ii] = RTREE_ZERO;

  184619.     for(iDim=0; iDim<pRtree->nDim; iDim++){

  184620.       RtreeDValue coord = (DCOORD(aCell[ii].aCoord[iDim*2+1]) - 

  184621.                                DCOORD(aCell[ii].aCoord[iDim*2]));

  184622.       aDistance[ii] += (coord-aCenterCoord[iDim])*(coord-aCenterCoord[iDim]);

  184623.     }

  184624.   }

  184625. 

  184626.   SortByDistance(aOrder, nCell, aDistance, aSpare);

  184627.   nodeZero(pRtree, pNode);

  184628. 

  184629.   for(ii=0; rc==SQLITE_OK && ii<(nCell-(RTREE_MINCELLS(pRtree)+1)); ii++){

  184630.     RtreeCell *p = &aCell[aOrder[ii]];

  184631.     nodeInsertCell(pRtree, pNode, p);

  184632.     if( p->iRowid==pCell->iRowid ){

  184633.       if( iHeight==0 ){

  184634.         rc = rowidWrite(pRtree, p->iRowid, pNode->iNode);

  184635.       }else{

  184636.         rc = parentWrite(pRtree, p->iRowid, pNode->iNode);

  184637.       }

  184638.     }

  184639.   }

  184640.   if( rc==SQLITE_OK ){

  184641.     rc = fixBoundingBox(pRtree, pNode);

  184642.   }

  184643.   for(; rc==SQLITE_OK && ii<nCell; ii++){

  184644.     /* Find a node to store this cell in. pNode->iNode currently contains

  184645.     ** the height of the sub-tree headed by the cell.

  184646.     */

  184647.     RtreeNode *pInsert;

  184648.     RtreeCell *p = &aCell[aOrder[ii]];

  184649.     rc = ChooseLeaf(pRtree, p, iHeight, &pInsert);

  184650.     if( rc==SQLITE_OK ){

  184651.       int rc2;

  184652.       rc = rtreeInsertCell(pRtree, pInsert, p, iHeight);

  184653.       rc2 = nodeRelease(pRtree, pInsert);

  184654.       if( rc==SQLITE_OK ){

  184655.         rc = rc2;

  184656.       }

  184657.     }

  184658.   }

  184659. 

  184660.   sqlite3_free(aCell);

  184661.   return rc;

  184662. }

  184663. 

  184664. /*

  184665. ** Insert cell pCell into node pNode. Node pNode is the head of a 

  184666. ** subtree iHeight high (leaf nodes have iHeight==0).

  184667. */

  184668. static int rtreeInsertCell(

  184669.   Rtree *pRtree,

  184670.   RtreeNode *pNode,

  184671.   RtreeCell *pCell,

  184672.   int iHeight

  184673. ){

  184674.   int rc = SQLITE_OK;

  184675.   if( iHeight>0 ){

  184676.     RtreeNode *pChild = nodeHashLookup(pRtree, pCell->iRowid);

  184677.     if( pChild ){

  184678.       nodeRelease(pRtree, pChild->pParent);

  184679.       nodeReference(pNode);

  184680.       pChild->pParent = pNode;

  184681.     }

  184682.   }

  184683.   if( nodeInsertCell(pRtree, pNode, pCell) ){

  184684.     if( iHeight<=pRtree->iReinsertHeight || pNode->iNode==1){

  184685.       rc = SplitNode(pRtree, pNode, pCell, iHeight);

  184686.     }else{

  184687.       pRtree->iReinsertHeight = iHeight;

  184688.       rc = Reinsert(pRtree, pNode, pCell, iHeight);

  184689.     }

  184690.   }else{

  184691.     rc = AdjustTree(pRtree, pNode, pCell);

  184692.     if( rc==SQLITE_OK ){

  184693.       if( iHeight==0 ){

  184694.         rc = rowidWrite(pRtree, pCell->iRowid, pNode->iNode);

  184695.       }else{

  184696.         rc = parentWrite(pRtree, pCell->iRowid, pNode->iNode);

  184697.       }

  184698.     }

  184699.   }

  184700.   return rc;

  184701. }

  184702. 

  184703. static int reinsertNodeContent(Rtree *pRtree, RtreeNode *pNode){

  184704.   int ii;

  184705.   int rc = SQLITE_OK;

  184706.   int nCell = NCELL(pNode);

  184707. 

  184708.   for(ii=0; rc==SQLITE_OK && ii<nCell; ii++){

  184709.     RtreeNode *pInsert;

  184710.     RtreeCell cell;

  184711.     nodeGetCell(pRtree, pNode, ii, &cell);

  184712. 

  184713.     /* Find a node to store this cell in. pNode->iNode currently contains

  184714.     ** the height of the sub-tree headed by the cell.

  184715.     */

  184716.     rc = ChooseLeaf(pRtree, &cell, (int)pNode->iNode, &pInsert);

  184717.     if( rc==SQLITE_OK ){

  184718.       int rc2;

  184719.       rc = rtreeInsertCell(pRtree, pInsert, &cell, (int)pNode->iNode);

  184720.       rc2 = nodeRelease(pRtree, pInsert);

  184721.       if( rc==SQLITE_OK ){

  184722.         rc = rc2;

  184723.       }

  184724.     }

  184725.   }

  184726.   return rc;

  184727. }

  184728. 

  184729. /*

  184730. ** Select a currently unused rowid for a new r-tree record.

  184731. */

  184732. static int rtreeNewRowid(Rtree *pRtree, i64 *piRowid){

  184733.   int rc;

  184734.   sqlite3_bind_null(pRtree->pWriteRowid, 1);

  184735.   sqlite3_bind_null(pRtree->pWriteRowid, 2);

  184736.   sqlite3_step(pRtree->pWriteRowid);

  184737.   rc = sqlite3_reset(pRtree->pWriteRowid);

  184738.   *piRowid = sqlite3_last_insert_rowid(pRtree->db);

  184739.   return rc;

  184740. }

  184741. 

  184742. /*

  184743. ** Remove the entry with rowid=iDelete from the r-tree structure.

  184744. */

  184745. static int rtreeDeleteRowid(Rtree *pRtree, sqlite3_int64 iDelete){

  184746.   int rc;                         /* Return code */

  184747.   RtreeNode *pLeaf = 0;           /* Leaf node containing record iDelete */

  184748.   int iCell;                      /* Index of iDelete cell in pLeaf */

  184749.   RtreeNode *pRoot = 0;           /* Root node of rtree structure */

  184750. 

  184751. 

  184752.   /* Obtain a reference to the root node to initialize Rtree.iDepth */

  184753.   rc = nodeAcquire(pRtree, 1, 0, &pRoot);

  184754. 

  184755.   /* Obtain a reference to the leaf node that contains the entry 

  184756.   ** about to be deleted. 

  184757.   */

  184758.   if( rc==SQLITE_OK ){

  184759.     rc = findLeafNode(pRtree, iDelete, &pLeaf, 0);

  184760.   }

  184761. 

  184762. #ifdef CORRUPT_DB

  184763.   assert( pLeaf!=0 || rc!=SQLITE_OK || CORRUPT_DB );

  184764. #endif

  184765. 

  184766.   /* Delete the cell in question from the leaf node. */

  184767.   if( rc==SQLITE_OK && pLeaf ){

  184768.     int rc2;

  184769.     rc = nodeRowidIndex(pRtree, pLeaf, iDelete, &iCell);

  184770.     if( rc==SQLITE_OK ){

  184771.       rc = deleteCell(pRtree, pLeaf, iCell, 0);

  184772.     }

  184773.     rc2 = nodeRelease(pRtree, pLeaf);

  184774.     if( rc==SQLITE_OK ){

  184775.       rc = rc2;

  184776.     }

  184777.   }

  184778. 

  184779.   /* Delete the corresponding entry in the <rtree>_rowid table. */

  184780.   if( rc==SQLITE_OK ){

  184781.     sqlite3_bind_int64(pRtree->pDeleteRowid, 1, iDelete);

  184782.     sqlite3_step(pRtree->pDeleteRowid);

  184783.     rc = sqlite3_reset(pRtree->pDeleteRowid);

  184784.   }

  184785. 

  184786.   /* Check if the root node now has exactly one child. If so, remove

  184787.   ** it, schedule the contents of the child for reinsertion and 

  184788.   ** reduce the tree height by one.

  184789.   **

  184790.   ** This is equivalent to copying the contents of the child into

  184791.   ** the root node (the operation that Gutman's paper says to perform 

  184792.   ** in this scenario).

  184793.   */

  184794.   if( rc==SQLITE_OK && pRtree->iDepth>0 && NCELL(pRoot)==1 ){

  184795.     int rc2;

  184796.     RtreeNode *pChild = 0;

  184797.     i64 iChild = nodeGetRowid(pRtree, pRoot, 0);

  184798.     rc = nodeAcquire(pRtree, iChild, pRoot, &pChild);

  184799.     if( rc==SQLITE_OK ){

  184800.       rc = removeNode(pRtree, pChild, pRtree->iDepth-1);

  184801.     }

  184802.     rc2 = nodeRelease(pRtree, pChild);

  184803.     if( rc==SQLITE_OK ) rc = rc2;

  184804.     if( rc==SQLITE_OK ){

  184805.       pRtree->iDepth--;

  184806.       writeInt16(pRoot->zData, pRtree->iDepth);

  184807.       pRoot->isDirty = 1;

  184808.     }

  184809.   }

  184810. 

  184811.   /* Re-insert the contents of any underfull nodes removed from the tree. */

  184812.   for(pLeaf=pRtree->pDeleted; pLeaf; pLeaf=pRtree->pDeleted){

  184813.     if( rc==SQLITE_OK ){

  184814.       rc = reinsertNodeContent(pRtree, pLeaf);

  184815.     }

  184816.     pRtree->pDeleted = pLeaf->pNext;

  184817.     pRtree->nNodeRef--;

  184818.     sqlite3_free(pLeaf);

  184819.   }

  184820. 

  184821.   /* Release the reference to the root node. */

  184822.   if( rc==SQLITE_OK ){

  184823.     rc = nodeRelease(pRtree, pRoot);

  184824.   }else{

  184825.     nodeRelease(pRtree, pRoot);

  184826.   }

  184827. 

  184828.   return rc;

  184829. }

  184830. 

  184831. /*

  184832. ** Rounding constants for float->double conversion.

  184833. */

  184834. #define RNDTOWARDS  (1.0 - 1.0/8388608.0)  /* Round towards zero */

  184835. #define RNDAWAY     (1.0 + 1.0/8388608.0)  /* Round away from zero */

  184836. 

  184837. #if !defined(SQLITE_RTREE_INT_ONLY)

  184838. /*

  184839. ** Convert an sqlite3_value into an RtreeValue (presumably a float)

  184840. ** while taking care to round toward negative or positive, respectively.

  184841. */

  184842. static RtreeValue rtreeValueDown(sqlite3_value *v){

  184843.   double d = sqlite3_value_double(v);

  184844.   float f = (float)d;

  184845.   if( f>d ){

  184846.     f = (float)(d*(d<0 ? RNDAWAY : RNDTOWARDS));

  184847.   }

  184848.   return f;

  184849. }

  184850. static RtreeValue rtreeValueUp(sqlite3_value *v){

  184851.   double d = sqlite3_value_double(v);

  184852.   float f = (float)d;

  184853.   if( f<d ){

  184854.     f = (float)(d*(d<0 ? RNDTOWARDS : RNDAWAY));

  184855.   }

  184856.   return f;

  184857. }

  184858. #endif /* !defined(SQLITE_RTREE_INT_ONLY) */

  184859. 

  184860. /*

  184861. ** A constraint has failed while inserting a row into an rtree table. 

  184862. ** Assuming no OOM error occurs, this function sets the error message 

  184863. ** (at pRtree->base.zErrMsg) to an appropriate value and returns

  184864. ** SQLITE_CONSTRAINT.

  184865. **

  184866. ** Parameter iCol is the index of the leftmost column involved in the

  184867. ** constraint failure. If it is 0, then the constraint that failed is

  184868. ** the unique constraint on the id column. Otherwise, it is the rtree

  184869. ** (c1<=c2) constraint on columns iCol and iCol+1 that has failed.

  184870. **

  184871. ** If an OOM occurs, SQLITE_NOMEM is returned instead of SQLITE_CONSTRAINT.

  184872. */

  184873. static int rtreeConstraintError(Rtree *pRtree, int iCol){

  184874.   sqlite3_stmt *pStmt = 0;

  184875.   char *zSql; 

  184876.   int rc;

  184877. 

  184878.   assert( iCol==0 || iCol%2 );

  184879.   zSql = sqlite3_mprintf("SELECT * FROM %Q.%Q", pRtree->zDb, pRtree->zName);

  184880.   if( zSql ){

  184881.     rc = sqlite3_prepare_v2(pRtree->db, zSql, -1, &pStmt, 0);

  184882.   }else{

  184883.     rc = SQLITE_NOMEM;

  184884.   }

  184885.   sqlite3_free(zSql);

  184886. 

  184887.   if( rc==SQLITE_OK ){

  184888.     if( iCol==0 ){

  184889.       const char *zCol = sqlite3_column_name(pStmt, 0);

  184890.       pRtree->base.zErrMsg = sqlite3_mprintf(

  184891.           "UNIQUE constraint failed: %s.%s", pRtree->zName, zCol

  184892.       );

  184893.     }else{

  184894.       const char *zCol1 = sqlite3_column_name(pStmt, iCol);

  184895.       const char *zCol2 = sqlite3_column_name(pStmt, iCol+1);

  184896.       pRtree->base.zErrMsg = sqlite3_mprintf(

  184897.           "rtree constraint failed: %s.(%s<=%s)", pRtree->zName, zCol1, zCol2

  184898.       );

  184899.     }

  184900.   }

  184901. 

  184902.   sqlite3_finalize(pStmt);

  184903.   return (rc==SQLITE_OK ? SQLITE_CONSTRAINT : rc);

  184904. }

  184905. 

  184906. 

  184907. 

  184908. /*

  184909. ** The xUpdate method for rtree module virtual tables.

  184910. */

  184911. static int rtreeUpdate(

  184912.   sqlite3_vtab *pVtab, 

  184913.   int nData, 

  184914.   sqlite3_value **aData, 

  184915.   sqlite_int64 *pRowid

  184916. ){

  184917.   Rtree *pRtree = (Rtree *)pVtab;

  184918.   int rc = SQLITE_OK;

  184919.   RtreeCell cell;                 /* New cell to insert if nData>1 */

  184920.   int bHaveRowid = 0;             /* Set to 1 after new rowid is determined */

  184921. 

  184922.   if( pRtree->nNodeRef ){

  184923.     /* Unable to write to the btree while another cursor is reading from it,

  184924.     ** since the write might do a rebalance which would disrupt the read

  184925.     ** cursor. */

  184926.     return SQLITE_LOCKED_VTAB;

  184927.   }

  184928.   rtreeReference(pRtree);

  184929.   assert(nData>=1);

  184930. 

  184931.   cell.iRowid = 0;  /* Used only to suppress a compiler warning */

  184932. 

  184933.   /* Constraint handling. A write operation on an r-tree table may return

  184934.   ** SQLITE_CONSTRAINT for two reasons:

  184935.   **

  184936.   **   1. A duplicate rowid value, or

  184937.   **   2. The supplied data violates the "x2>=x1" constraint.

  184938.   **

  184939.   ** In the first case, if the conflict-handling mode is REPLACE, then

  184940.   ** the conflicting row can be removed before proceeding. In the second

  184941.   ** case, SQLITE_CONSTRAINT must be returned regardless of the

  184942.   ** conflict-handling mode specified by the user.

  184943.   */

  184944.   if( nData>1 ){

  184945.     int ii;

  184946.     int nn = nData - 4;

  184947. 

  184948.     if( nn > pRtree->nDim2 ) nn = pRtree->nDim2;

  184949.     /* Populate the cell.aCoord[] array. The first coordinate is aData[3].

  184950.     **

  184951.     ** NB: nData can only be less than nDim*2+3 if the rtree is mis-declared

  184952.     ** with "column" that are interpreted as table constraints.

  184953.     ** Example:  CREATE VIRTUAL TABLE bad USING rtree(x,y,CHECK(y>5));

  184954.     ** This problem was discovered after years of use, so we silently ignore

  184955.     ** these kinds of misdeclared tables to avoid breaking any legacy.

  184956.     */

  184957. 

  184958. #ifndef SQLITE_RTREE_INT_ONLY

  184959.     if( pRtree->eCoordType==RTREE_COORD_REAL32 ){

  184960.       for(ii=0; ii<nn; ii+=2){

  184961.         cell.aCoord[ii].f = rtreeValueDown(aData[ii+3]);

  184962.         cell.aCoord[ii+1].f = rtreeValueUp(aData[ii+4]);

  184963.         if( cell.aCoord[ii].f>cell.aCoord[ii+1].f ){

  184964.           rc = rtreeConstraintError(pRtree, ii+1);

  184965.           goto constraint;

  184966.         }

  184967.       }

  184968.     }else

  184969. #endif

  184970.     {

  184971.       for(ii=0; ii<nn; ii+=2){

  184972.         cell.aCoord[ii].i = sqlite3_value_int(aData[ii+3]);

  184973.         cell.aCoord[ii+1].i = sqlite3_value_int(aData[ii+4]);

  184974.         if( cell.aCoord[ii].i>cell.aCoord[ii+1].i ){

  184975.           rc = rtreeConstraintError(pRtree, ii+1);

  184976.           goto constraint;

  184977.         }

  184978.       }

  184979.     }

  184980. 

  184981.     /* If a rowid value was supplied, check if it is already present in 

  184982.     ** the table. If so, the constraint has failed. */

  184983.     if( sqlite3_value_type(aData[2])!=SQLITE_NULL ){

  184984.       cell.iRowid = sqlite3_value_int64(aData[2]);

  184985.       if( sqlite3_value_type(aData[0])==SQLITE_NULL

  184986.        || sqlite3_value_int64(aData[0])!=cell.iRowid

  184987.       ){

  184988.         int steprc;

  184989.         sqlite3_bind_int64(pRtree->pReadRowid, 1, cell.iRowid);

  184990.         steprc = sqlite3_step(pRtree->pReadRowid);

  184991.         rc = sqlite3_reset(pRtree->pReadRowid);

  184992.         if( SQLITE_ROW==steprc ){

  184993.           if( sqlite3_vtab_on_conflict(pRtree->db)==SQLITE_REPLACE ){

  184994.             rc = rtreeDeleteRowid(pRtree, cell.iRowid);

  184995.           }else{

  184996.             rc = rtreeConstraintError(pRtree, 0);

  184997.             goto constraint;

  184998.           }

  184999.         }

  185000.       }

  185001.       bHaveRowid = 1;

  185002.     }

  185003.   }

  185004. 

  185005.   /* If aData[0] is not an SQL NULL value, it is the rowid of a

  185006.   ** record to delete from the r-tree table. The following block does

  185007.   ** just that.

  185008.   */

  185009.   if( sqlite3_value_type(aData[0])!=SQLITE_NULL ){

  185010.     rc = rtreeDeleteRowid(pRtree, sqlite3_value_int64(aData[0]));

  185011.   }

  185012. 

  185013.   /* If the aData[] array contains more than one element, elements

  185014.   ** (aData[2]..aData[argc-1]) contain a new record to insert into

  185015.   ** the r-tree structure.

  185016.   */

  185017.   if( rc==SQLITE_OK && nData>1 ){

  185018.     /* Insert the new record into the r-tree */

  185019.     RtreeNode *pLeaf = 0;

  185020. 

  185021.     /* Figure out the rowid of the new row. */

  185022.     if( bHaveRowid==0 ){

  185023.       rc = rtreeNewRowid(pRtree, &cell.iRowid);

  185024.     }

  185025.     *pRowid = cell.iRowid;

  185026. 

  185027.     if( rc==SQLITE_OK ){

  185028.       rc = ChooseLeaf(pRtree, &cell, 0, &pLeaf);

  185029.     }

  185030.     if( rc==SQLITE_OK ){

  185031.       int rc2;

  185032.       pRtree->iReinsertHeight = -1;

  185033.       rc = rtreeInsertCell(pRtree, pLeaf, &cell, 0);

  185034.       rc2 = nodeRelease(pRtree, pLeaf);

  185035.       if( rc==SQLITE_OK ){

  185036.         rc = rc2;

  185037.       }

  185038.     }

  185039.     if( rc==SQLITE_OK && pRtree->nAux ){

  185040.       sqlite3_stmt *pUp = pRtree->pWriteAux;

  185041.       int jj;

  185042.       sqlite3_bind_int64(pUp, 1, *pRowid);

  185043.       for(jj=0; jj<pRtree->nAux; jj++){

  185044.         sqlite3_bind_value(pUp, jj+2, aData[pRtree->nDim2+3+jj]);

  185045.       }

  185046.       sqlite3_step(pUp);

  185047.       rc = sqlite3_reset(pUp);

  185048.     }

  185049.   }

  185050. 

  185051. constraint:

  185052.   rtreeRelease(pRtree);

  185053.   return rc;

  185054. }

  185055. 

  185056. /*

  185057. ** Called when a transaction starts.

  185058. */

  185059. static int rtreeBeginTransaction(sqlite3_vtab *pVtab){

  185060.   Rtree *pRtree = (Rtree *)pVtab;

  185061.   assert( pRtree->inWrTrans==0 );

  185062.   pRtree->inWrTrans++;

  185063.   return SQLITE_OK;

  185064. }

  185065. 

  185066. /*

  185067. ** Called when a transaction completes (either by COMMIT or ROLLBACK).

  185068. ** The sqlite3_blob object should be released at this point.

  185069. */

  185070. static int rtreeEndTransaction(sqlite3_vtab *pVtab){

  185071.   Rtree *pRtree = (Rtree *)pVtab;

  185072.   pRtree->inWrTrans = 0;

  185073.   nodeBlobReset(pRtree);

  185074.   return SQLITE_OK;

  185075. }

  185076. 

  185077. /*

  185078. ** The xRename method for rtree module virtual tables.

  185079. */

  185080. static int rtreeRename(sqlite3_vtab *pVtab, const char *zNewName){

  185081.   Rtree *pRtree = (Rtree *)pVtab;

  185082.   int rc = SQLITE_NOMEM;

  185083.   char *zSql = sqlite3_mprintf(

  185084.     "ALTER TABLE %Q.'%q_node'   RENAME TO \"%w_node\";"

  185085.     "ALTER TABLE %Q.'%q_parent' RENAME TO \"%w_parent\";"

  185086.     "ALTER TABLE %Q.'%q_rowid'  RENAME TO \"%w_rowid\";"

  185087.     , pRtree->zDb, pRtree->zName, zNewName 

  185088.     , pRtree->zDb, pRtree->zName, zNewName 

  185089.     , pRtree->zDb, pRtree->zName, zNewName

  185090.   );

  185091.   if( zSql ){

  185092.     nodeBlobReset(pRtree);

  185093.     rc = sqlite3_exec(pRtree->db, zSql, 0, 0, 0);

  185094.     sqlite3_free(zSql);

  185095.   }

  185096.   return rc;

  185097. }

  185098. 

  185099. /*

  185100. ** The xSavepoint method.

  185101. **

  185102. ** This module does not need to do anything to support savepoints. However,

  185103. ** it uses this hook to close any open blob handle. This is done because a 

  185104. ** DROP TABLE command - which fortunately always opens a savepoint - cannot 

  185105. ** succeed if there are any open blob handles. i.e. if the blob handle were

  185106. ** not closed here, the following would fail:

  185107. **

  185108. **   BEGIN;

  185109. **     INSERT INTO rtree...

  185110. **     DROP TABLE <tablename>;    -- Would fail with SQLITE_LOCKED

  185111. **   COMMIT;

  185112. */

  185113. static int rtreeSavepoint(sqlite3_vtab *pVtab, int iSavepoint){

  185114.   Rtree *pRtree = (Rtree *)pVtab;

  185115.   u8 iwt = pRtree->inWrTrans;

  185116.   UNUSED_PARAMETER(iSavepoint);

  185117.   pRtree->inWrTrans = 0;

  185118.   nodeBlobReset(pRtree);

  185119.   pRtree->inWrTrans = iwt;

  185120.   return SQLITE_OK;

  185121. }

  185122. 

  185123. /*

  185124. ** This function populates the pRtree->nRowEst variable with an estimate

  185125. ** of the number of rows in the virtual table. If possible, this is based

  185126. ** on sqlite_stat1 data. Otherwise, use RTREE_DEFAULT_ROWEST.

  185127. */

  185128. static int rtreeQueryStat1(sqlite3 *db, Rtree *pRtree){

  185129.   const char *zFmt = "SELECT stat FROM %Q.sqlite_stat1 WHERE tbl = '%q_rowid'";

  185130.   char *zSql;

  185131.   sqlite3_stmt *p;

  185132.   int rc;

  185133.   i64 nRow = 0;

  185134. 

  185135.   rc = sqlite3_table_column_metadata(

  185136.       db, pRtree->zDb, "sqlite_stat1",0,0,0,0,0,0

  185137.   );

  185138.   if( rc!=SQLITE_OK ){

  185139.     pRtree->nRowEst = RTREE_DEFAULT_ROWEST;

  185140.     return rc==SQLITE_ERROR ? SQLITE_OK : rc;

  185141.   }

  185142.   zSql = sqlite3_mprintf(zFmt, pRtree->zDb, pRtree->zName);

  185143.   if( zSql==0 ){

  185144.     rc = SQLITE_NOMEM;

  185145.   }else{

  185146.     rc = sqlite3_prepare_v2(db, zSql, -1, &p, 0);

  185147.     if( rc==SQLITE_OK ){

  185148.       if( sqlite3_step(p)==SQLITE_ROW ) nRow = sqlite3_column_int64(p, 0);

  185149.       rc = sqlite3_finalize(p);

  185150.     }else if( rc!=SQLITE_NOMEM ){

  185151.       rc = SQLITE_OK;

  185152.     }

  185153. 

  185154.     if( rc==SQLITE_OK ){

  185155.       if( nRow==0 ){

  185156.         pRtree->nRowEst = RTREE_DEFAULT_ROWEST;

  185157.       }else{

  185158.         pRtree->nRowEst = MAX(nRow, RTREE_MIN_ROWEST);

  185159.       }

  185160.     }

  185161.     sqlite3_free(zSql);

  185162.   }

  185163. 

  185164.   return rc;

  185165. }

  185166. 

  185167. 

  185168. /*

  185169. ** Return true if zName is the extension on one of the shadow tables used

  185170. ** by this module.

  185171. */

  185172. static int rtreeShadowName(const char *zName){

  185173.   static const char *azName[] = {

  185174.     "node", "parent", "rowid"

  185175.   };

  185176.   unsigned int i;

  185177.   for(i=0; i<sizeof(azName)/sizeof(azName[0]); i++){

  185178.     if( sqlite3_stricmp(zName, azName[i])==0 ) return 1;

  185179.   }

  185180.   return 0;

  185181. }

  185182. 

  185183. static sqlite3_module rtreeModule = {

  185184.   3,                          /* iVersion */

  185185.   rtreeCreate,                /* xCreate - create a table */

  185186.   rtreeConnect,               /* xConnect - connect to an existing table */

  185187.   rtreeBestIndex,             /* xBestIndex - Determine search strategy */

  185188.   rtreeDisconnect,            /* xDisconnect - Disconnect from a table */

  185189.   rtreeDestroy,               /* xDestroy - Drop a table */

  185190.   rtreeOpen,                  /* xOpen - open a cursor */

  185191.   rtreeClose,                 /* xClose - close a cursor */

  185192.   rtreeFilter,                /* xFilter - configure scan constraints */

  185193.   rtreeNext,                  /* xNext - advance a cursor */

  185194.   rtreeEof,                   /* xEof */

  185195.   rtreeColumn,                /* xColumn - read data */

  185196.   rtreeRowid,                 /* xRowid - read data */

  185197.   rtreeUpdate,                /* xUpdate - write data */

  185198.   rtreeBeginTransaction,      /* xBegin - begin transaction */

  185199.   rtreeEndTransaction,        /* xSync - sync transaction */

  185200.   rtreeEndTransaction,        /* xCommit - commit transaction */

  185201.   rtreeEndTransaction,        /* xRollback - rollback transaction */

  185202.   0,                          /* xFindFunction - function overloading */

  185203.   rtreeRename,                /* xRename - rename the table */

  185204.   rtreeSavepoint,             /* xSavepoint */

  185205.   0,                          /* xRelease */

  185206.   0,                          /* xRollbackTo */

  185207.   rtreeShadowName             /* xShadowName */

  185208. };

  185209. 

  185210. static int rtreeSqlInit(

  185211.   Rtree *pRtree, 

  185212.   sqlite3 *db, 

  185213.   const char *zDb, 

  185214.   const char *zPrefix, 

  185215.   int isCreate

  185216. ){

  185217.   int rc = SQLITE_OK;

  185218. 

  185219.   #define N_STATEMENT 8

  185220.   static const char *azSql[N_STATEMENT] = {

  185221.     /* Write the xxx_node table */

  185222.     "INSERT OR REPLACE INTO '%q'.'%q_node' VALUES(?1, ?2)",

  185223.     "DELETE FROM '%q'.'%q_node' WHERE nodeno = ?1",

  185224. 

  185225.     /* Read and write the xxx_rowid table */

  185226.     "SELECT nodeno FROM '%q'.'%q_rowid' WHERE rowid = ?1",

  185227.     "INSERT OR REPLACE INTO '%q'.'%q_rowid' VALUES(?1, ?2)",

  185228.     "DELETE FROM '%q'.'%q_rowid' WHERE rowid = ?1",

  185229. 

  185230.     /* Read and write the xxx_parent table */

  185231.     "SELECT parentnode FROM '%q'.'%q_parent' WHERE nodeno = ?1",

  185232.     "INSERT OR REPLACE INTO '%q'.'%q_parent' VALUES(?1, ?2)",

  185233.     "DELETE FROM '%q'.'%q_parent' WHERE nodeno = ?1"

  185234.   };

  185235.   sqlite3_stmt **appStmt[N_STATEMENT];

  185236.   int i;

  185237.   const int f = SQLITE_PREPARE_PERSISTENT|SQLITE_PREPARE_NO_VTAB;

  185238. 

  185239.   pRtree->db = db;

  185240. 

  185241.   if( isCreate ){

  185242.     char *zCreate;

  185243.     sqlite3_str *p = sqlite3_str_new(db);

  185244.     int ii;

  185245.     sqlite3_str_appendf(p,

  185246.        "CREATE TABLE \"%w\".\"%w_rowid\"(rowid INTEGER PRIMARY KEY,nodeno",

  185247.        zDb, zPrefix);

  185248.     for(ii=0; ii<pRtree->nAux; ii++){

  185249.       sqlite3_str_appendf(p,",a%d",ii);

  185250.     }

  185251.     sqlite3_str_appendf(p,

  185252.       ");CREATE TABLE \"%w\".\"%w_node\"(nodeno INTEGER PRIMARY KEY,data);",

  185253.       zDb, zPrefix);

  185254.     sqlite3_str_appendf(p,

  185255.     "CREATE TABLE \"%w\".\"%w_parent\"(nodeno INTEGER PRIMARY KEY,parentnode);",

  185256.       zDb, zPrefix);

  185257.     sqlite3_str_appendf(p,

  185258.        "INSERT INTO \"%w\".\"%w_node\"VALUES(1,zeroblob(%d))",

  185259.        zDb, zPrefix, pRtree->iNodeSize);

  185260.     zCreate = sqlite3_str_finish(p);

  185261.     if( !zCreate ){

  185262.       return SQLITE_NOMEM;

  185263.     }

  185264.     rc = sqlite3_exec(db, zCreate, 0, 0, 0);

  185265.     sqlite3_free(zCreate);

  185266.     if( rc!=SQLITE_OK ){

  185267.       return rc;

  185268.     }

  185269.   }

  185270. 

  185271.   appStmt[0] = &pRtree->pWriteNode;

  185272.   appStmt[1] = &pRtree->pDeleteNode;

  185273.   appStmt[2] = &pRtree->pReadRowid;

  185274.   appStmt[3] = &pRtree->pWriteRowid;

  185275.   appStmt[4] = &pRtree->pDeleteRowid;

  185276.   appStmt[5] = &pRtree->pReadParent;

  185277.   appStmt[6] = &pRtree->pWriteParent;

  185278.   appStmt[7] = &pRtree->pDeleteParent;

  185279. 

  185280.   rc = rtreeQueryStat1(db, pRtree);

  185281.   for(i=0; i<N_STATEMENT && rc==SQLITE_OK; i++){

  185282.     char *zSql;

  185283.     const char *zFormat;

  185284.     if( i!=3 || pRtree->nAux==0 ){

  185285.        zFormat = azSql[i];

  185286.     }else {

  185287.        /* An UPSERT is very slightly slower than REPLACE, but it is needed

  185288.        ** if there are auxiliary columns */

  185289.        zFormat = "INSERT INTO\"%w\".\"%w_rowid\"(rowid,nodeno)VALUES(?1,?2)"

  185290.                   "ON CONFLICT(rowid)DO UPDATE SET nodeno=excluded.nodeno";

  185291.     }

  185292.     zSql = sqlite3_mprintf(zFormat, zDb, zPrefix);

  185293.     if( zSql ){

  185294.       rc = sqlite3_prepare_v3(db, zSql, -1, f, appStmt[i], 0); 

  185295.     }else{

  185296.       rc = SQLITE_NOMEM;

  185297.     }

  185298.     sqlite3_free(zSql);

  185299.   }

  185300.   if( pRtree->nAux ){

  185301.     pRtree->zReadAuxSql = sqlite3_mprintf(

  185302.        "SELECT * FROM \"%w\".\"%w_rowid\" WHERE rowid=?1",

  185303.        zDb, zPrefix);

  185304.     if( pRtree->zReadAuxSql==0 ){

  185305.       rc = SQLITE_NOMEM;

  185306.     }else{

  185307.       sqlite3_str *p = sqlite3_str_new(db);

  185308.       int ii;

  185309.       char *zSql;

  185310.       sqlite3_str_appendf(p, "UPDATE \"%w\".\"%w_rowid\"SET ", zDb, zPrefix);

  185311.       for(ii=0; ii<pRtree->nAux; ii++){

  185312.         if( ii ) sqlite3_str_append(p, ",", 1);

  185313.         if( ii<pRtree->nAuxNotNull ){

  185314.           sqlite3_str_appendf(p,"a%d=coalesce(?%d,a%d)",ii,ii+2,ii);

  185315.         }else{

  185316.           sqlite3_str_appendf(p,"a%d=?%d",ii,ii+2);

  185317.         }

  185318.       }

  185319.       sqlite3_str_appendf(p, " WHERE rowid=?1");

  185320.       zSql = sqlite3_str_finish(p);

  185321.       if( zSql==0 ){

  185322.         rc = SQLITE_NOMEM;

  185323.       }else{

  185324.         rc = sqlite3_prepare_v3(db, zSql, -1, f, &pRtree->pWriteAux, 0); 

  185325.         sqlite3_free(zSql);

  185326.       }

  185327.     }

  185328.   }

  185329. 

  185330.   return rc;

  185331. }

  185332. 

  185333. /*

  185334. ** The second argument to this function contains the text of an SQL statement

  185335. ** that returns a single integer value. The statement is compiled and executed

  185336. ** using database connection db. If successful, the integer value returned

  185337. ** is written to *piVal and SQLITE_OK returned. Otherwise, an SQLite error

  185338. ** code is returned and the value of *piVal after returning is not defined.

  185339. */

  185340. static int getIntFromStmt(sqlite3 *db, const char *zSql, int *piVal){

  185341.   int rc = SQLITE_NOMEM;

  185342.   if( zSql ){

  185343.     sqlite3_stmt *pStmt = 0;

  185344.     rc = sqlite3_prepare_v2(db, zSql, -1, &pStmt, 0);

  185345.     if( rc==SQLITE_OK ){

  185346.       if( SQLITE_ROW==sqlite3_step(pStmt) ){

  185347.         *piVal = sqlite3_column_int(pStmt, 0);

  185348.       }

  185349.       rc = sqlite3_finalize(pStmt);

  185350.     }

  185351.   }

  185352.   return rc;

  185353. }

  185354. 

  185355. /*

  185356. ** This function is called from within the xConnect() or xCreate() method to

  185357. ** determine the node-size used by the rtree table being created or connected

  185358. ** to. If successful, pRtree->iNodeSize is populated and SQLITE_OK returned.

  185359. ** Otherwise, an SQLite error code is returned.

  185360. **

  185361. ** If this function is being called as part of an xConnect(), then the rtree

  185362. ** table already exists. In this case the node-size is determined by inspecting

  185363. ** the root node of the tree.

  185364. **

  185365. ** Otherwise, for an xCreate(), use 64 bytes less than the database page-size. 

  185366. ** This ensures that each node is stored on a single database page. If the 

  185367. ** database page-size is so large that more than RTREE_MAXCELLS entries 

  185368. ** would fit in a single node, use a smaller node-size.

  185369. */

  185370. static int getNodeSize(

  185371.   sqlite3 *db,                    /* Database handle */

  185372.   Rtree *pRtree,                  /* Rtree handle */

  185373.   int isCreate,                   /* True for xCreate, false for xConnect */

  185374.   char **pzErr                    /* OUT: Error message, if any */

  185375. ){

  185376.   int rc;

  185377.   char *zSql;

  185378.   if( isCreate ){

  185379.     int iPageSize = 0;

  185380.     zSql = sqlite3_mprintf("PRAGMA %Q.page_size", pRtree->zDb);

  185381.     rc = getIntFromStmt(db, zSql, &iPageSize);

  185382.     if( rc==SQLITE_OK ){

  185383.       pRtree->iNodeSize = iPageSize-64;

  185384.       if( (4+pRtree->nBytesPerCell*RTREE_MAXCELLS)<pRtree->iNodeSize ){

  185385.         pRtree->iNodeSize = 4+pRtree->nBytesPerCell*RTREE_MAXCELLS;

  185386.       }

  185387.     }else{

  185388.       *pzErr = sqlite3_mprintf("%s", sqlite3_errmsg(db));

  185389.     }

  185390.   }else{

  185391.     zSql = sqlite3_mprintf(

  185392.         "SELECT length(data) FROM '%q'.'%q_node' WHERE nodeno = 1",

  185393.         pRtree->zDb, pRtree->zName

  185394.     );

  185395.     rc = getIntFromStmt(db, zSql, &pRtree->iNodeSize);

  185396.     if( rc!=SQLITE_OK ){

  185397.       *pzErr = sqlite3_mprintf("%s", sqlite3_errmsg(db));

  185398.     }else if( pRtree->iNodeSize<(512-64) ){

  185399.       rc = SQLITE_CORRUPT_VTAB;

  185400.       RTREE_IS_CORRUPT(pRtree);

  185401.       *pzErr = sqlite3_mprintf("undersize RTree blobs in \"%q_node\"",

  185402.                                pRtree->zName);

  185403.     }

  185404.   }

  185405. 

  185406.   sqlite3_free(zSql);

  185407.   return rc;

  185408. }

  185409. 

  185410. /* 

  185411. ** This function is the implementation of both the xConnect and xCreate

  185412. ** methods of the r-tree virtual table.

  185413. **

  185414. **   argv[0]   -> module name

  185415. **   argv[1]   -> database name

  185416. **   argv[2]   -> table name

  185417. **   argv[...] -> column names...

  185418. */

  185419. static int rtreeInit(

  185420.   sqlite3 *db,                        /* Database connection */

  185421.   void *pAux,                         /* One of the RTREE_COORD_* constants */

  185422.   int argc, const char *const*argv,   /* Parameters to CREATE TABLE statement */

  185423.   sqlite3_vtab **ppVtab,              /* OUT: New virtual table */

  185424.   char **pzErr,                       /* OUT: Error message, if any */

  185425.   int isCreate                        /* True for xCreate, false for xConnect */

  185426. ){

  185427.   int rc = SQLITE_OK;

  185428.   Rtree *pRtree;

  185429.   int nDb;              /* Length of string argv[1] */

  185430.   int nName;            /* Length of string argv[2] */

  185431.   int eCoordType = (pAux ? RTREE_COORD_INT32 : RTREE_COORD_REAL32);

  185432.   sqlite3_str *pSql;

  185433.   char *zSql;

  185434.   int ii = 4;

  185435.   int iErr;

  185436. 

  185437.   const char *aErrMsg[] = {

  185438.     0,                                                    /* 0 */

  185439.     "Wrong number of columns for an rtree table",         /* 1 */

  185440.     "Too few columns for an rtree table",                 /* 2 */

  185441.     "Too many columns for an rtree table",                /* 3 */

  185442.     "Auxiliary rtree columns must be last"                /* 4 */

  185443.   };

  185444. 

  185445.   assert( RTREE_MAX_AUX_COLUMN<256 ); /* Aux columns counted by a u8 */

  185446.   if( argc>RTREE_MAX_AUX_COLUMN+3 ){

  185447.     *pzErr = sqlite3_mprintf("%s", aErrMsg[3]);

  185448.     return SQLITE_ERROR;

  185449.   }

  185450. 

  185451.   sqlite3_vtab_config(db, SQLITE_VTAB_CONSTRAINT_SUPPORT, 1);

  185452. 

  185453.   /* Allocate the sqlite3_vtab structure */

  185454.   nDb = (int)strlen(argv[1]);

  185455.   nName = (int)strlen(argv[2]);

  185456.   pRtree = (Rtree *)sqlite3_malloc64(sizeof(Rtree)+nDb+nName+2);

  185457.   if( !pRtree ){

  185458.     return SQLITE_NOMEM;

  185459.   }

  185460.   memset(pRtree, 0, sizeof(Rtree)+nDb+nName+2);

  185461.   pRtree->nBusy = 1;

  185462.   pRtree->base.pModule = &rtreeModule;

  185463.   pRtree->zDb = (char *)&pRtree[1];

  185464.   pRtree->zName = &pRtree->zDb[nDb+1];

  185465.   pRtree->eCoordType = (u8)eCoordType;

  185466.   memcpy(pRtree->zDb, argv[1], nDb);

  185467.   memcpy(pRtree->zName, argv[2], nName);

  185468. 

  185469. 

  185470.   /* Create/Connect to the underlying relational database schema. If

  185471.   ** that is successful, call sqlite3_declare_vtab() to configure

  185472.   ** the r-tree table schema.

  185473.   */

  185474.   pSql = sqlite3_str_new(db);

  185475.   sqlite3_str_appendf(pSql, "CREATE TABLE x(%s", argv[3]);

  185476.   for(ii=4; ii<argc; ii++){

  185477.     if( argv[ii][0]=='+' ){

  185478.       pRtree->nAux++;

  185479.       sqlite3_str_appendf(pSql, ",%s", argv[ii]+1);

  185480.     }else if( pRtree->nAux>0 ){

  185481.       break;

  185482.     }else{

  185483.       pRtree->nDim2++;

  185484.       sqlite3_str_appendf(pSql, ",%s", argv[ii]);

  185485.     }

  185486.   }

  185487.   sqlite3_str_appendf(pSql, ");");

  185488.   zSql = sqlite3_str_finish(pSql);

  185489.   if( !zSql ){

  185490.     rc = SQLITE_NOMEM;

  185491.   }else if( ii<argc ){

  185492.     *pzErr = sqlite3_mprintf("%s", aErrMsg[4]);

  185493.     rc = SQLITE_ERROR;

  185494.   }else if( SQLITE_OK!=(rc = sqlite3_declare_vtab(db, zSql)) ){

  185495.     *pzErr = sqlite3_mprintf("%s", sqlite3_errmsg(db));

  185496.   }

  185497.   sqlite3_free(zSql);

  185498.   if( rc ) goto rtreeInit_fail;

  185499.   pRtree->nDim = pRtree->nDim2/2;

  185500.   if( pRtree->nDim<1 ){

  185501.     iErr = 2;

  185502.   }else if( pRtree->nDim2>RTREE_MAX_DIMENSIONS*2 ){

  185503.     iErr = 3;

  185504.   }else if( pRtree->nDim2 % 2 ){

  185505.     iErr = 1;

  185506.   }else{

  185507.     iErr = 0;

  185508.   }

  185509.   if( iErr ){

  185510.     *pzErr = sqlite3_mprintf("%s", aErrMsg[iErr]);

  185511.     goto rtreeInit_fail;

  185512.   }

  185513.   pRtree->nBytesPerCell = 8 + pRtree->nDim2*4;

  185514. 

  185515.   /* Figure out the node size to use. */

  185516.   rc = getNodeSize(db, pRtree, isCreate, pzErr);

  185517.   if( rc ) goto rtreeInit_fail;

  185518.   rc = rtreeSqlInit(pRtree, db, argv[1], argv[2], isCreate);

  185519.   if( rc ){

  185520.     *pzErr = sqlite3_mprintf("%s", sqlite3_errmsg(db));

  185521.     goto rtreeInit_fail;

  185522.   }

  185523. 

  185524.   *ppVtab = (sqlite3_vtab *)pRtree;

  185525.   return SQLITE_OK;

  185526. 

  185527. rtreeInit_fail:

  185528.   if( rc==SQLITE_OK ) rc = SQLITE_ERROR;

  185529.   assert( *ppVtab==0 );

  185530.   assert( pRtree->nBusy==1 );

  185531.   rtreeRelease(pRtree);

  185532.   return rc;

  185533. }

  185534. 

  185535. 

  185536. /*

  185537. ** Implementation of a scalar function that decodes r-tree nodes to

  185538. ** human readable strings. This can be used for debugging and analysis.

  185539. **

  185540. ** The scalar function takes two arguments: (1) the number of dimensions

  185541. ** to the rtree (between 1 and 5, inclusive) and (2) a blob of data containing

  185542. ** an r-tree node.  For a two-dimensional r-tree structure called "rt", to

  185543. ** deserialize all nodes, a statement like:

  185544. **

  185545. **   SELECT rtreenode(2, data) FROM rt_node;

  185546. **

  185547. ** The human readable string takes the form of a Tcl list with one

  185548. ** entry for each cell in the r-tree node. Each entry is itself a

  185549. ** list, containing the 8-byte rowid/pageno followed by the 

  185550. ** <num-dimension>*2 coordinates.

  185551. */

  185552. static void rtreenode(sqlite3_context *ctx, int nArg, sqlite3_value **apArg){

  185553.   RtreeNode node;

  185554.   Rtree tree;

  185555.   int ii;

  185556.   int nData;

  185557.   int errCode;

  185558.   sqlite3_str *pOut;

  185559. 

  185560.   UNUSED_PARAMETER(nArg);

  185561.   memset(&node, 0, sizeof(RtreeNode));

  185562.   memset(&tree, 0, sizeof(Rtree));

  185563.   tree.nDim = (u8)sqlite3_value_int(apArg[0]);

  185564.   if( tree.nDim<1 || tree.nDim>5 ) return;

  185565.   tree.nDim2 = tree.nDim*2;

  185566.   tree.nBytesPerCell = 8 + 8 * tree.nDim;

  185567.   node.zData = (u8 *)sqlite3_value_blob(apArg[1]);

  185568.   nData = sqlite3_value_bytes(apArg[1]);

  185569.   if( nData<4 ) return;

  185570.   if( nData<NCELL(&node)*tree.nBytesPerCell ) return;

  185571. 

  185572.   pOut = sqlite3_str_new(0);

  185573.   for(ii=0; ii<NCELL(&node); ii++){

  185574.     RtreeCell cell;

  185575.     int jj;

  185576. 

  185577.     nodeGetCell(&tree, &node, ii, &cell);

  185578.     if( ii>0 ) sqlite3_str_append(pOut, " ", 1);

  185579.     sqlite3_str_appendf(pOut, "{%lld", cell.iRowid);

  185580.     for(jj=0; jj<tree.nDim2; jj++){

  185581. #ifndef SQLITE_RTREE_INT_ONLY

  185582.       sqlite3_str_appendf(pOut, " %g", (double)cell.aCoord[jj].f);

  185583. #else

  185584.       sqlite3_str_appendf(pOut, " %d", cell.aCoord[jj].i);

  185585. #endif

  185586.     }

  185587.     sqlite3_str_append(pOut, "}", 1);

  185588.   }

  185589.   errCode = sqlite3_str_errcode(pOut);

  185590.   sqlite3_result_text(ctx, sqlite3_str_finish(pOut), -1, sqlite3_free);

  185591.   sqlite3_result_error_code(ctx, errCode);

  185592. }

  185593. 

  185594. /* This routine implements an SQL function that returns the "depth" parameter

  185595. ** from the front of a blob that is an r-tree node.  For example:

  185596. **

  185597. **     SELECT rtreedepth(data) FROM rt_node WHERE nodeno=1;

  185598. **

  185599. ** The depth value is 0 for all nodes other than the root node, and the root

  185600. ** node always has nodeno=1, so the example above is the primary use for this

  185601. ** routine.  This routine is intended for testing and analysis only.

  185602. */

  185603. static void rtreedepth(sqlite3_context *ctx, int nArg, sqlite3_value **apArg){

  185604.   UNUSED_PARAMETER(nArg);

  185605.   if( sqlite3_value_type(apArg[0])!=SQLITE_BLOB 

  185606.    || sqlite3_value_bytes(apArg[0])<2

  185607.   ){

  185608.     sqlite3_result_error(ctx, "Invalid argument to rtreedepth()", -1); 

  185609.   }else{

  185610.     u8 *zBlob = (u8 *)sqlite3_value_blob(apArg[0]);

  185611.     sqlite3_result_int(ctx, readInt16(zBlob));

  185612.   }

  185613. }

  185614. 

  185615. /*

  185616. ** Context object passed between the various routines that make up the

  185617. ** implementation of integrity-check function rtreecheck().

  185618. */

  185619. typedef struct RtreeCheck RtreeCheck;

  185620. struct RtreeCheck {

  185621.   sqlite3 *db;                    /* Database handle */

  185622.   const char *zDb;                /* Database containing rtree table */

  185623.   const char *zTab;               /* Name of rtree table */

  185624.   int bInt;                       /* True for rtree_i32 table */

  185625.   int nDim;                       /* Number of dimensions for this rtree tbl */

  185626.   sqlite3_stmt *pGetNode;         /* Statement used to retrieve nodes */

  185627.   sqlite3_stmt *aCheckMapping[2]; /* Statements to query %_parent/%_rowid */

  185628.   int nLeaf;                      /* Number of leaf cells in table */

  185629.   int nNonLeaf;                   /* Number of non-leaf cells in table */

  185630.   int rc;                         /* Return code */

  185631.   char *zReport;                  /* Message to report */

  185632.   int nErr;                       /* Number of lines in zReport */

  185633. };

  185634. 

  185635. #define RTREE_CHECK_MAX_ERROR 100

  185636. 

  185637. /*

  185638. ** Reset SQL statement pStmt. If the sqlite3_reset() call returns an error,

  185639. ** and RtreeCheck.rc==SQLITE_OK, set RtreeCheck.rc to the error code.

  185640. */

  185641. static void rtreeCheckReset(RtreeCheck *pCheck, sqlite3_stmt *pStmt){

  185642.   int rc = sqlite3_reset(pStmt);

  185643.   if( pCheck->rc==SQLITE_OK ) pCheck->rc = rc;

  185644. }

  185645. 

  185646. /*

  185647. ** The second and subsequent arguments to this function are a format string

  185648. ** and printf style arguments. This function formats the string and attempts

  185649. ** to compile it as an SQL statement.

  185650. **

  185651. ** If successful, a pointer to the new SQL statement is returned. Otherwise,

  185652. ** NULL is returned and an error code left in RtreeCheck.rc.

  185653. */

  185654. static sqlite3_stmt *rtreeCheckPrepare(

  185655.   RtreeCheck *pCheck,             /* RtreeCheck object */

  185656.   const char *zFmt, ...           /* Format string and trailing args */

  185657. ){

  185658.   va_list ap;

  185659.   char *z;

  185660.   sqlite3_stmt *pRet = 0;

  185661. 

  185662.   va_start(ap, zFmt);

  185663.   z = sqlite3_vmprintf(zFmt, ap);

  185664. 

  185665.   if( pCheck->rc==SQLITE_OK ){

  185666.     if( z==0 ){

  185667.       pCheck->rc = SQLITE_NOMEM;

  185668.     }else{

  185669.       pCheck->rc = sqlite3_prepare_v2(pCheck->db, z, -1, &pRet, 0);

  185670.     }

  185671.   }

  185672. 

  185673.   sqlite3_free(z);

  185674.   va_end(ap);

  185675.   return pRet;

  185676. }

  185677. 

  185678. /*

  185679. ** The second and subsequent arguments to this function are a printf()

  185680. ** style format string and arguments. This function formats the string and

  185681. ** appends it to the report being accumuated in pCheck.

  185682. */

  185683. static void rtreeCheckAppendMsg(RtreeCheck *pCheck, const char *zFmt, ...){

  185684.   va_list ap;

  185685.   va_start(ap, zFmt);

  185686.   if( pCheck->rc==SQLITE_OK && pCheck->nErr<RTREE_CHECK_MAX_ERROR ){

  185687.     char *z = sqlite3_vmprintf(zFmt, ap);

  185688.     if( z==0 ){

  185689.       pCheck->rc = SQLITE_NOMEM;

  185690.     }else{

  185691.       pCheck->zReport = sqlite3_mprintf("%z%s%z", 

  185692.           pCheck->zReport, (pCheck->zReport ? "\n" : ""), z

  185693.       );

  185694.       if( pCheck->zReport==0 ){

  185695.         pCheck->rc = SQLITE_NOMEM;

  185696.       }

  185697.     }

  185698.     pCheck->nErr++;

  185699.   }

  185700.   va_end(ap);

  185701. }

  185702. 

  185703. /*

  185704. ** This function is a no-op if there is already an error code stored

  185705. ** in the RtreeCheck object indicated by the first argument. NULL is

  185706. ** returned in this case.

  185707. **

  185708. ** Otherwise, the contents of rtree table node iNode are loaded from

  185709. ** the database and copied into a buffer obtained from sqlite3_malloc().

  185710. ** If no error occurs, a pointer to the buffer is returned and (*pnNode)

  185711. ** is set to the size of the buffer in bytes.

  185712. **

  185713. ** Or, if an error does occur, NULL is returned and an error code left

  185714. ** in the RtreeCheck object. The final value of *pnNode is undefined in

  185715. ** this case.

  185716. */

  185717. static u8 *rtreeCheckGetNode(RtreeCheck *pCheck, i64 iNode, int *pnNode){

  185718.   u8 *pRet = 0;                   /* Return value */

  185719. 

  185720.   if( pCheck->rc==SQLITE_OK && pCheck->pGetNode==0 ){

  185721.     pCheck->pGetNode = rtreeCheckPrepare(pCheck,

  185722.         "SELECT data FROM %Q.'%q_node' WHERE nodeno=?", 

  185723.         pCheck->zDb, pCheck->zTab

  185724.     );

  185725.   }

  185726. 

  185727.   if( pCheck->rc==SQLITE_OK ){

  185728.     sqlite3_bind_int64(pCheck->pGetNode, 1, iNode);

  185729.     if( sqlite3_step(pCheck->pGetNode)==SQLITE_ROW ){

  185730.       int nNode = sqlite3_column_bytes(pCheck->pGetNode, 0);

  185731.       const u8 *pNode = (const u8*)sqlite3_column_blob(pCheck->pGetNode, 0);

  185732.       pRet = sqlite3_malloc64(nNode);

  185733.       if( pRet==0 ){

  185734.         pCheck->rc = SQLITE_NOMEM;

  185735.       }else{

  185736.         memcpy(pRet, pNode, nNode);

  185737.         *pnNode = nNode;

  185738.       }

  185739.     }

  185740.     rtreeCheckReset(pCheck, pCheck->pGetNode);

  185741.     if( pCheck->rc==SQLITE_OK && pRet==0 ){

  185742.       rtreeCheckAppendMsg(pCheck, "Node %lld missing from database", iNode);

  185743.     }

  185744.   }

  185745. 

  185746.   return pRet;

  185747. }

  185748. 

  185749. /*

  185750. ** This function is used to check that the %_parent (if bLeaf==0) or %_rowid

  185751. ** (if bLeaf==1) table contains a specified entry. The schemas of the

  185752. ** two tables are:

  185753. **

  185754. **   CREATE TABLE %_parent(nodeno INTEGER PRIMARY KEY, parentnode INTEGER)

  185755. **   CREATE TABLE %_rowid(rowid INTEGER PRIMARY KEY, nodeno INTEGER, ...)

  185756. **

  185757. ** In both cases, this function checks that there exists an entry with

  185758. ** IPK value iKey and the second column set to iVal.

  185759. **

  185760. */

  185761. static void rtreeCheckMapping(

  185762.   RtreeCheck *pCheck,             /* RtreeCheck object */

  185763.   int bLeaf,                      /* True for a leaf cell, false for interior */

  185764.   i64 iKey,                       /* Key for mapping */

  185765.   i64 iVal                        /* Expected value for mapping */

  185766. ){

  185767.   int rc;

  185768.   sqlite3_stmt *pStmt;

  185769.   const char *azSql[2] = {

  185770.     "SELECT parentnode FROM %Q.'%q_parent' WHERE nodeno=?1",

  185771.     "SELECT nodeno FROM %Q.'%q_rowid' WHERE rowid=?1"

  185772.   };

  185773. 

  185774.   assert( bLeaf==0 || bLeaf==1 );

  185775.   if( pCheck->aCheckMapping[bLeaf]==0 ){

  185776.     pCheck->aCheckMapping[bLeaf] = rtreeCheckPrepare(pCheck,

  185777.         azSql[bLeaf], pCheck->zDb, pCheck->zTab

  185778.     );

  185779.   }

  185780.   if( pCheck->rc!=SQLITE_OK ) return;

  185781. 

  185782.   pStmt = pCheck->aCheckMapping[bLeaf];

  185783.   sqlite3_bind_int64(pStmt, 1, iKey);

  185784.   rc = sqlite3_step(pStmt);

  185785.   if( rc==SQLITE_DONE ){

  185786.     rtreeCheckAppendMsg(pCheck, "Mapping (%lld -> %lld) missing from %s table",

  185787.         iKey, iVal, (bLeaf ? "%_rowid" : "%_parent")

  185788.     );

  185789.   }else if( rc==SQLITE_ROW ){

  185790.     i64 ii = sqlite3_column_int64(pStmt, 0);

  185791.     if( ii!=iVal ){

  185792.       rtreeCheckAppendMsg(pCheck, 

  185793.           "Found (%lld -> %lld) in %s table, expected (%lld -> %lld)",

  185794.           iKey, ii, (bLeaf ? "%_rowid" : "%_parent"), iKey, iVal

  185795.       );

  185796.     }

  185797.   }

  185798.   rtreeCheckReset(pCheck, pStmt);

  185799. }

  185800. 

  185801. /*

  185802. ** Argument pCell points to an array of coordinates stored on an rtree page.

  185803. ** This function checks that the coordinates are internally consistent (no

  185804. ** x1>x2 conditions) and adds an error message to the RtreeCheck object

  185805. ** if they are not.

  185806. **

  185807. ** Additionally, if pParent is not NULL, then it is assumed to point to

  185808. ** the array of coordinates on the parent page that bound the page 

  185809. ** containing pCell. In this case it is also verified that the two

  185810. ** sets of coordinates are mutually consistent and an error message added

  185811. ** to the RtreeCheck object if they are not.

  185812. */

  185813. static void rtreeCheckCellCoord(

  185814.   RtreeCheck *pCheck, 

  185815.   i64 iNode,                      /* Node id to use in error messages */

  185816.   int iCell,                      /* Cell number to use in error messages */

  185817.   u8 *pCell,                      /* Pointer to cell coordinates */

  185818.   u8 *pParent                     /* Pointer to parent coordinates */

  185819. ){

  185820.   RtreeCoord c1, c2;

  185821.   RtreeCoord p1, p2;

  185822.   int i;

  185823. 

  185824.   for(i=0; i<pCheck->nDim; i++){

  185825.     readCoord(&pCell[4*2*i], &c1);

  185826.     readCoord(&pCell[4*(2*i + 1)], &c2);

  185827. 

  185828.     /* printf("%e, %e\n", c1.u.f, c2.u.f); */

  185829.     if( pCheck->bInt ? c1.i>c2.i : c1.f>c2.f ){

  185830.       rtreeCheckAppendMsg(pCheck, 

  185831.           "Dimension %d of cell %d on node %lld is corrupt", i, iCell, iNode

  185832.       );

  185833.     }

  185834. 

  185835.     if( pParent ){

  185836.       readCoord(&pParent[4*2*i], &p1);

  185837.       readCoord(&pParent[4*(2*i + 1)], &p2);

  185838. 

  185839.       if( (pCheck->bInt ? c1.i<p1.i : c1.f<p1.f) 

  185840.        || (pCheck->bInt ? c2.i>p2.i : c2.f>p2.f)

  185841.       ){

  185842.         rtreeCheckAppendMsg(pCheck, 

  185843.             "Dimension %d of cell %d on node %lld is corrupt relative to parent"

  185844.             , i, iCell, iNode

  185845.         );

  185846.       }

  185847.     }

  185848.   }

  185849. }

  185850. 

  185851. /*

  185852. ** Run rtreecheck() checks on node iNode, which is at depth iDepth within

  185853. ** the r-tree structure. Argument aParent points to the array of coordinates

  185854. ** that bound node iNode on the parent node.

  185855. **

  185856. ** If any problems are discovered, an error message is appended to the

  185857. ** report accumulated in the RtreeCheck object.

  185858. */

  185859. static void rtreeCheckNode(

  185860.   RtreeCheck *pCheck,

  185861.   int iDepth,                     /* Depth of iNode (0==leaf) */

  185862.   u8 *aParent,                    /* Buffer containing parent coords */

  185863.   i64 iNode                       /* Node to check */

  185864. ){

  185865.   u8 *aNode = 0;

  185866.   int nNode = 0;

  185867. 

  185868.   assert( iNode==1 || aParent!=0 );

  185869.   assert( pCheck->nDim>0 );

  185870. 

  185871.   aNode = rtreeCheckGetNode(pCheck, iNode, &nNode);

  185872.   if( aNode ){

  185873.     if( nNode<4 ){

  185874.       rtreeCheckAppendMsg(pCheck, 

  185875.           "Node %lld is too small (%d bytes)", iNode, nNode

  185876.       );

  185877.     }else{

  185878.       int nCell;                  /* Number of cells on page */

  185879.       int i;                      /* Used to iterate through cells */

  185880.       if( aParent==0 ){

  185881.         iDepth = readInt16(aNode);

  185882.         if( iDepth>RTREE_MAX_DEPTH ){

  185883.           rtreeCheckAppendMsg(pCheck, "Rtree depth out of range (%d)", iDepth);

  185884.           sqlite3_free(aNode);

  185885.           return;

  185886.         }

  185887.       }

  185888.       nCell = readInt16(&aNode[2]);

  185889.       if( (4 + nCell*(8 + pCheck->nDim*2*4))>nNode ){

  185890.         rtreeCheckAppendMsg(pCheck, 

  185891.             "Node %lld is too small for cell count of %d (%d bytes)", 

  185892.             iNode, nCell, nNode

  185893.         );

  185894.       }else{

  185895.         for(i=0; i<nCell; i++){

  185896.           u8 *pCell = &aNode[4 + i*(8 + pCheck->nDim*2*4)];

  185897.           i64 iVal = readInt64(pCell);

  185898.           rtreeCheckCellCoord(pCheck, iNode, i, &pCell[8], aParent);

  185899. 

  185900.           if( iDepth>0 ){

  185901.             rtreeCheckMapping(pCheck, 0, iVal, iNode);

  185902.             rtreeCheckNode(pCheck, iDepth-1, &pCell[8], iVal);

  185903.             pCheck->nNonLeaf++;

  185904.           }else{

  185905.             rtreeCheckMapping(pCheck, 1, iVal, iNode);

  185906.             pCheck->nLeaf++;

  185907.           }

  185908.         }

  185909.       }

  185910.     }

  185911.     sqlite3_free(aNode);

  185912.   }

  185913. }

  185914. 

  185915. /*

  185916. ** The second argument to this function must be either "_rowid" or

  185917. ** "_parent". This function checks that the number of entries in the

  185918. ** %_rowid or %_parent table is exactly nExpect. If not, it adds

  185919. ** an error message to the report in the RtreeCheck object indicated

  185920. ** by the first argument.

  185921. */

  185922. static void rtreeCheckCount(RtreeCheck *pCheck, const char *zTbl, i64 nExpect){

  185923.   if( pCheck->rc==SQLITE_OK ){

  185924.     sqlite3_stmt *pCount;

  185925.     pCount = rtreeCheckPrepare(pCheck, "SELECT count(*) FROM %Q.'%q%s'",

  185926.         pCheck->zDb, pCheck->zTab, zTbl

  185927.     );

  185928.     if( pCount ){

  185929.       if( sqlite3_step(pCount)==SQLITE_ROW ){

  185930.         i64 nActual = sqlite3_column_int64(pCount, 0);

  185931.         if( nActual!=nExpect ){

  185932.           rtreeCheckAppendMsg(pCheck, "Wrong number of entries in %%%s table"

  185933.               " - expected %lld, actual %lld" , zTbl, nExpect, nActual

  185934.           );

  185935.         }

  185936.       }

  185937.       pCheck->rc = sqlite3_finalize(pCount);

  185938.     }

  185939.   }

  185940. }

  185941. 

  185942. /*

  185943. ** This function does the bulk of the work for the rtree integrity-check.

  185944. ** It is called by rtreecheck(), which is the SQL function implementation.

  185945. */

  185946. static int rtreeCheckTable(

  185947.   sqlite3 *db,                    /* Database handle to access db through */

  185948.   const char *zDb,                /* Name of db ("main", "temp" etc.) */

  185949.   const char *zTab,               /* Name of rtree table to check */

  185950.   char **pzReport                 /* OUT: sqlite3_malloc'd report text */

  185951. ){

  185952.   RtreeCheck check;               /* Common context for various routines */

  185953.   sqlite3_stmt *pStmt = 0;        /* Used to find column count of rtree table */

  185954.   int bEnd = 0;                   /* True if transaction should be closed */

  185955.   int nAux = 0;                   /* Number of extra columns. */

  185956. 

  185957.   /* Initialize the context object */

  185958.   memset(&check, 0, sizeof(check));

  185959.   check.db = db;

  185960.   check.zDb = zDb;

  185961.   check.zTab = zTab;

  185962. 

  185963.   /* If there is not already an open transaction, open one now. This is

  185964.   ** to ensure that the queries run as part of this integrity-check operate

  185965.   ** on a consistent snapshot.  */

  185966.   if( sqlite3_get_autocommit(db) ){

  185967.     check.rc = sqlite3_exec(db, "BEGIN", 0, 0, 0);

  185968.     bEnd = 1;

  185969.   }

  185970. 

  185971.   /* Find the number of auxiliary columns */

  185972.   if( check.rc==SQLITE_OK ){

  185973.     pStmt = rtreeCheckPrepare(&check, "SELECT * FROM %Q.'%q_rowid'", zDb, zTab);

  185974.     if( pStmt ){

  185975.       nAux = sqlite3_column_count(pStmt) - 2;

  185976.       sqlite3_finalize(pStmt);

  185977.     }

  185978.     check.rc = SQLITE_OK;

  185979.   }

  185980. 

  185981.   /* Find number of dimensions in the rtree table. */

  185982.   pStmt = rtreeCheckPrepare(&check, "SELECT * FROM %Q.%Q", zDb, zTab);

  185983.   if( pStmt ){

  185984.     int rc;

  185985.     check.nDim = (sqlite3_column_count(pStmt) - 1 - nAux) / 2;

  185986.     if( check.nDim<1 ){

  185987.       rtreeCheckAppendMsg(&check, "Schema corrupt or not an rtree");

  185988.     }else if( SQLITE_ROW==sqlite3_step(pStmt) ){

  185989.       check.bInt = (sqlite3_column_type(pStmt, 1)==SQLITE_INTEGER);

  185990.     }

  185991.     rc = sqlite3_finalize(pStmt);

  185992.     if( rc!=SQLITE_CORRUPT ) check.rc = rc;

  185993.   }

  185994. 

  185995.   /* Do the actual integrity-check */

  185996.   if( check.nDim>=1 ){

  185997.     if( check.rc==SQLITE_OK ){

  185998.       rtreeCheckNode(&check, 0, 0, 1);

  185999.     }

  186000.     rtreeCheckCount(&check, "_rowid", check.nLeaf);

  186001.     rtreeCheckCount(&check, "_parent", check.nNonLeaf);

  186002.   }

  186003. 

  186004.   /* Finalize SQL statements used by the integrity-check */

  186005.   sqlite3_finalize(check.pGetNode);

  186006.   sqlite3_finalize(check.aCheckMapping[0]);

  186007.   sqlite3_finalize(check.aCheckMapping[1]);

  186008. 

  186009.   /* If one was opened, close the transaction */

  186010.   if( bEnd ){

  186011.     int rc = sqlite3_exec(db, "END", 0, 0, 0);

  186012.     if( check.rc==SQLITE_OK ) check.rc = rc;

  186013.   }

  186014.   *pzReport = check.zReport;

  186015.   return check.rc;

  186016. }

  186017. 

  186018. /*

  186019. ** Usage:

  186020. **

  186021. **   rtreecheck(<rtree-table>);

  186022. **   rtreecheck(<database>, <rtree-table>);

  186023. **

  186024. ** Invoking this SQL function runs an integrity-check on the named rtree

  186025. ** table. The integrity-check verifies the following:

  186026. **

  186027. **   1. For each cell in the r-tree structure (%_node table), that:

  186028. **

  186029. **       a) for each dimension, (coord1 <= coord2).

  186030. **

  186031. **       b) unless the cell is on the root node, that the cell is bounded

  186032. **          by the parent cell on the parent node.

  186033. **

  186034. **       c) for leaf nodes, that there is an entry in the %_rowid 

  186035. **          table corresponding to the cell's rowid value that 

  186036. **          points to the correct node.

  186037. **

  186038. **       d) for cells on non-leaf nodes, that there is an entry in the 

  186039. **          %_parent table mapping from the cell's child node to the

  186040. **          node that it resides on.

  186041. **

  186042. **   2. That there are the same number of entries in the %_rowid table

  186043. **      as there are leaf cells in the r-tree structure, and that there

  186044. **      is a leaf cell that corresponds to each entry in the %_rowid table.

  186045. **

  186046. **   3. That there are the same number of entries in the %_parent table

  186047. **      as there are non-leaf cells in the r-tree structure, and that 

  186048. **      there is a non-leaf cell that corresponds to each entry in the 

  186049. **      %_parent table.

  186050. */

  186051. static void rtreecheck(

  186052.   sqlite3_context *ctx, 

  186053.   int nArg, 

  186054.   sqlite3_value **apArg

  186055. ){

  186056.   if( nArg!=1 && nArg!=2 ){

  186057.     sqlite3_result_error(ctx, 

  186058.         "wrong number of arguments to function rtreecheck()", -1

  186059.     );

  186060.   }else{

  186061.     int rc;

  186062.     char *zReport = 0;

  186063.     const char *zDb = (const char*)sqlite3_value_text(apArg[0]);

  186064.     const char *zTab;

  186065.     if( nArg==1 ){

  186066.       zTab = zDb;

  186067.       zDb = "main";

  186068.     }else{

  186069.       zTab = (const char*)sqlite3_value_text(apArg[1]);

  186070.     }

  186071.     rc = rtreeCheckTable(sqlite3_context_db_handle(ctx), zDb, zTab, &zReport);

  186072.     if( rc==SQLITE_OK ){

  186073.       sqlite3_result_text(ctx, zReport ? zReport : "ok", -1, SQLITE_TRANSIENT);

  186074.     }else{

  186075.       sqlite3_result_error_code(ctx, rc);

  186076.     }

  186077.     sqlite3_free(zReport);

  186078.   }

  186079. }

  186080. 

  186081. /* Conditionally include the geopoly code */

  186082. #ifdef SQLITE_ENABLE_GEOPOLY

  186083. /************** Include geopoly.c in the middle of rtree.c *******************/

  186084. /************** Begin file geopoly.c *****************************************/

  186085. /*

  186086. ** 2018-05-25

  186087. **

  186088. ** The author disclaims copyright to this source code.  In place of

  186089. ** a legal notice, here is a blessing:

  186090. **

  186091. **    May you do good and not evil.

  186092. **    May you find forgiveness for yourself and forgive others.

  186093. **    May you share freely, never taking more than you give.

  186094. **

  186095. ******************************************************************************

  186096. **

  186097. ** This file implements an alternative R-Tree virtual table that

  186098. ** uses polygons to express the boundaries of 2-dimensional objects.

  186099. **

  186100. ** This file is #include-ed onto the end of "rtree.c" so that it has

  186101. ** access to all of the R-Tree internals.

  186102. */

  186103. /* #include <stdlib.h> */

  186104. 

  186105. /* Enable -DGEOPOLY_ENABLE_DEBUG for debugging facilities */

  186106. #ifdef GEOPOLY_ENABLE_DEBUG

  186107.   static int geo_debug = 0;

  186108. # define GEODEBUG(X) if(geo_debug)printf X

  186109. #else

  186110. # define GEODEBUG(X)

  186111. #endif

  186112. 

  186113. #ifndef JSON_NULL   /* The following stuff repeats things found in json1 */

  186114. /*

  186115. ** Versions of isspace(), isalnum() and isdigit() to which it is safe

  186116. ** to pass signed char values.

  186117. */

  186118. #ifdef sqlite3Isdigit

  186119.    /* Use the SQLite core versions if this routine is part of the

  186120.    ** SQLite amalgamation */

  186121. #  define safe_isdigit(x)  sqlite3Isdigit(x)

  186122. #  define safe_isalnum(x)  sqlite3Isalnum(x)

  186123. #  define safe_isxdigit(x) sqlite3Isxdigit(x)

  186124. #else

  186125.    /* Use the standard library for separate compilation */

  186126. #include <ctype.h>  /* amalgamator: keep */

  186127. #  define safe_isdigit(x)  isdigit((unsigned char)(x))

  186128. #  define safe_isalnum(x)  isalnum((unsigned char)(x))

  186129. #  define safe_isxdigit(x) isxdigit((unsigned char)(x))

  186130. #endif

  186131. 

  186132. /*

  186133. ** Growing our own isspace() routine this way is twice as fast as

  186134. ** the library isspace() function.

  186135. */

  186136. static const char geopolyIsSpace[] = {

  186137.   0, 0, 0, 0, 0, 0, 0, 0,     0, 1, 1, 0, 0, 1, 0, 0,

  186138.   0, 0, 0, 0, 0, 0, 0, 0,     0, 0, 0, 0, 0, 0, 0, 0,

  186139.   1, 0, 0, 0, 0, 0, 0, 0,     0, 0, 0, 0, 0, 0, 0, 0,

  186140.   0, 0, 0, 0, 0, 0, 0, 0,     0, 0, 0, 0, 0, 0, 0, 0,

  186141.   0, 0, 0, 0, 0, 0, 0, 0,     0, 0, 0, 0, 0, 0, 0, 0,

  186142.   0, 0, 0, 0, 0, 0, 0, 0,     0, 0, 0, 0, 0, 0, 0, 0,

  186143.   0, 0, 0, 0, 0, 0, 0, 0,     0, 0, 0, 0, 0, 0, 0, 0,

  186144.   0, 0, 0, 0, 0, 0, 0, 0,     0, 0, 0, 0, 0, 0, 0, 0,

  186145.   0, 0, 0, 0, 0, 0, 0, 0,     0, 0, 0, 0, 0, 0, 0, 0,

  186146.   0, 0, 0, 0, 0, 0, 0, 0,     0, 0, 0, 0, 0, 0, 0, 0,

  186147.   0, 0, 0, 0, 0, 0, 0, 0,     0, 0, 0, 0, 0, 0, 0, 0,

  186148.   0, 0, 0, 0, 0, 0, 0, 0,     0, 0, 0, 0, 0, 0, 0, 0,

  186149.   0, 0, 0, 0, 0, 0, 0, 0,     0, 0, 0, 0, 0, 0, 0, 0,

  186150.   0, 0, 0, 0, 0, 0, 0, 0,     0, 0, 0, 0, 0, 0, 0, 0,

  186151.   0, 0, 0, 0, 0, 0, 0, 0,     0, 0, 0, 0, 0, 0, 0, 0,

  186152.   0, 0, 0, 0, 0, 0, 0, 0,     0, 0, 0, 0, 0, 0, 0, 0,

  186153. };

  186154. #define safe_isspace(x) (geopolyIsSpace[(unsigned char)x])

  186155. #endif /* JSON NULL - back to original code */

  186156. 

  186157. /* Compiler and version */

  186158. #ifndef GCC_VERSION

  186159. #if defined(__GNUC__) && !defined(SQLITE_DISABLE_INTRINSIC)

  186160. # define GCC_VERSION (__GNUC__*1000000+__GNUC_MINOR__*1000+__GNUC_PATCHLEVEL__)

  186161. #else

  186162. # define GCC_VERSION 0

  186163. #endif

  186164. #endif

  186165. #ifndef MSVC_VERSION

  186166. #if defined(_MSC_VER) && !defined(SQLITE_DISABLE_INTRINSIC)

  186167. # define MSVC_VERSION _MSC_VER

  186168. #else

  186169. # define MSVC_VERSION 0

  186170. #endif

  186171. #endif

  186172. 

  186173. /* Datatype for coordinates

  186174. */

  186175. typedef float GeoCoord;

  186176. 

  186177. /*

  186178. ** Internal representation of a polygon.

  186179. **

  186180. ** The polygon consists of a sequence of vertexes.  There is a line

  186181. ** segment between each pair of vertexes, and one final segment from

  186182. ** the last vertex back to the first.  (This differs from the GeoJSON

  186183. ** standard in which the final vertex is a repeat of the first.)

  186184. **

  186185. ** The polygon follows the right-hand rule.  The area to the right of

  186186. ** each segment is "outside" and the area to the left is "inside".

  186187. **

  186188. ** The on-disk representation consists of a 4-byte header followed by

  186189. ** the values.  The 4-byte header is:

  186190. **

  186191. **      encoding    (1 byte)   0=big-endian, 1=little-endian

  186192. **      nvertex     (3 bytes)  Number of vertexes as a big-endian integer

  186193. **

  186194. ** Enough space is allocated for 4 coordinates, to work around over-zealous

  186195. ** warnings coming from some compiler (notably, clang). In reality, the size

  186196. ** of each GeoPoly memory allocate is adjusted as necessary so that the

  186197. ** GeoPoly.a[] array at the end is the appropriate size.

  186198. */

  186199. typedef struct GeoPoly GeoPoly;

  186200. struct GeoPoly {

  186201.   int nVertex;          /* Number of vertexes */

  186202.   unsigned char hdr[4]; /* Header for on-disk representation */

  186203.   GeoCoord a[8];        /* 2*nVertex values. X (longitude) first, then Y */

  186204. };

  186205. 

  186206. /* The size of a memory allocation needed for a GeoPoly object sufficient

  186207. ** to hold N coordinate pairs.

  186208. */

  186209. #define GEOPOLY_SZ(N)  (sizeof(GeoPoly) + sizeof(GeoCoord)*2*((N)-4))

  186210. 

  186211. /* Macros to access coordinates of a GeoPoly.

  186212. ** We have to use these macros, rather than just say p->a[i] in order

  186213. ** to silence (incorrect) UBSAN warnings if the array index is too large.

  186214. */

  186215. #define GeoX(P,I)  (((GeoCoord*)(P)->a)[(I)*2])

  186216. #define GeoY(P,I)  (((GeoCoord*)(P)->a)[(I)*2+1])

  186217. 

  186218. 

  186219. /*

  186220. ** State of a parse of a GeoJSON input.

  186221. */

  186222. typedef struct GeoParse GeoParse;

  186223. struct GeoParse {

  186224.   const unsigned char *z;   /* Unparsed input */

  186225.   int nVertex;              /* Number of vertexes in a[] */

  186226.   int nAlloc;               /* Space allocated to a[] */

  186227.   int nErr;                 /* Number of errors encountered */

  186228.   GeoCoord *a;          /* Array of vertexes.  From sqlite3_malloc64() */

  186229. };

  186230. 

  186231. /* Do a 4-byte byte swap */

  186232. static void geopolySwab32(unsigned char *a){

  186233.   unsigned char t = a[0];

  186234.   a[0] = a[3];

  186235.   a[3] = t;

  186236.   t = a[1];

  186237.   a[1] = a[2];

  186238.   a[2] = t;

  186239. }

  186240. 

  186241. /* Skip whitespace.  Return the next non-whitespace character. */

  186242. static char geopolySkipSpace(GeoParse *p){

  186243.   while( safe_isspace(p->z[0]) ) p->z++;

  186244.   return p->z[0];

  186245. }

  186246. 

  186247. /* Parse out a number.  Write the value into *pVal if pVal!=0.

  186248. ** return non-zero on success and zero if the next token is not a number.

  186249. */

  186250. static int geopolyParseNumber(GeoParse *p, GeoCoord *pVal){

  186251.   char c = geopolySkipSpace(p);

  186252.   const unsigned char *z = p->z;

  186253.   int j = 0;

  186254.   int seenDP = 0;

  186255.   int seenE = 0;

  186256.   if( c=='-' ){

  186257.     j = 1;

  186258.     c = z[j];

  186259.   }

  186260.   if( c=='0' && z[j+1]>='0' && z[j+1]<='9' ) return 0;

  186261.   for(;; j++){

  186262.     c = z[j];

  186263.     if( safe_isdigit(c) ) continue;

  186264.     if( c=='.' ){

  186265.       if( z[j-1]=='-' ) return 0;

  186266.       if( seenDP ) return 0;

  186267.       seenDP = 1;

  186268.       continue;

  186269.     }

  186270.     if( c=='e' || c=='E' ){

  186271.       if( z[j-1]<'0' ) return 0;

  186272.       if( seenE ) return -1;

  186273.       seenDP = seenE = 1;

  186274.       c = z[j+1];

  186275.       if( c=='+' || c=='-' ){

  186276.         j++;

  186277.         c = z[j+1];

  186278.       }

  186279.       if( c<'0' || c>'9' ) return 0;

  186280.       continue;

  186281.     }

  186282.     break;

  186283.   }

  186284.   if( z[j-1]<'0' ) return 0;

  186285.   if( pVal ){

  186286. #ifdef SQLITE_AMALGAMATION

  186287.      /* The sqlite3AtoF() routine is much much faster than atof(), if it

  186288.      ** is available */

  186289.      double r;

  186290.      (void)sqlite3AtoF((const char*)p->z, &r, j, SQLITE_UTF8);

  186291.      *pVal = r;

  186292. #else

  186293.      *pVal = (GeoCoord)atof((const char*)p->z);

  186294. #endif

  186295.   }

  186296.   p->z += j;

  186297.   return 1;

  186298. }

  186299. 

  186300. /*

  186301. ** If the input is a well-formed JSON array of coordinates with at least

  186302. ** four coordinates and where each coordinate is itself a two-value array,

  186303. ** then convert the JSON into a GeoPoly object and return a pointer to

  186304. ** that object.

  186305. **

  186306. ** If any error occurs, return NULL.

  186307. */

  186308. static GeoPoly *geopolyParseJson(const unsigned char *z, int *pRc){

  186309.   GeoParse s;

  186310.   int rc = SQLITE_OK;

  186311.   memset(&s, 0, sizeof(s));

  186312.   s.z = z;

  186313.   if( geopolySkipSpace(&s)=='[' ){

  186314.     s.z++;

  186315.     while( geopolySkipSpace(&s)=='[' ){

  186316.       int ii = 0;

  186317.       char c;

  186318.       s.z++;

  186319.       if( s.nVertex>=s.nAlloc ){

  186320.         GeoCoord *aNew;

  186321.         s.nAlloc = s.nAlloc*2 + 16;

  186322.         aNew = sqlite3_realloc64(s.a, s.nAlloc*sizeof(GeoCoord)*2 );

  186323.         if( aNew==0 ){

  186324.           rc = SQLITE_NOMEM;

  186325.           s.nErr++;

  186326.           break;

  186327.         }

  186328.         s.a = aNew;

  186329.       }

  186330.       while( geopolyParseNumber(&s, ii<=1 ? &s.a[s.nVertex*2+ii] : 0) ){

  186331.         ii++;

  186332.         if( ii==2 ) s.nVertex++;

  186333.         c = geopolySkipSpace(&s);

  186334.         s.z++;

  186335.         if( c==',' ) continue;

  186336.         if( c==']' && ii>=2 ) break;

  186337.         s.nErr++;

  186338.         rc = SQLITE_ERROR;

  186339.         goto parse_json_err;

  186340.       }

  186341.       if( geopolySkipSpace(&s)==',' ){

  186342.         s.z++;

  186343.         continue;

  186344.       }

  186345.       break;

  186346.     }

  186347.     if( geopolySkipSpace(&s)==']'

  186348.      && s.nVertex>=4

  186349.      && s.a[0]==s.a[s.nVertex*2-2]

  186350.      && s.a[1]==s.a[s.nVertex*2-1]

  186351.      && (s.z++, geopolySkipSpace(&s)==0)

  186352.     ){

  186353.       GeoPoly *pOut;

  186354.       int x = 1;

  186355.       s.nVertex--;  /* Remove the redundant vertex at the end */

  186356.       pOut = sqlite3_malloc64( GEOPOLY_SZ((sqlite3_int64)s.nVertex) );

  186357.       x = 1;

  186358.       if( pOut==0 ) goto parse_json_err;

  186359.       pOut->nVertex = s.nVertex;

  186360.       memcpy(pOut->a, s.a, s.nVertex*2*sizeof(GeoCoord));

  186361.       pOut->hdr[0] = *(unsigned char*)&x;

  186362.       pOut->hdr[1] = (s.nVertex>>16)&0xff;

  186363.       pOut->hdr[2] = (s.nVertex>>8)&0xff;

  186364.       pOut->hdr[3] = s.nVertex&0xff;

  186365.       sqlite3_free(s.a);

  186366.       if( pRc ) *pRc = SQLITE_OK;

  186367.       return pOut;

  186368.     }else{

  186369.       s.nErr++;

  186370.       rc = SQLITE_ERROR;

  186371.     }

  186372.   }

  186373. parse_json_err:

  186374.   if( pRc ) *pRc = rc;

  186375.   sqlite3_free(s.a);

  186376.   return 0;

  186377. }

  186378. 

  186379. /*

  186380. ** Given a function parameter, try to interpret it as a polygon, either

  186381. ** in the binary format or JSON text.  Compute a GeoPoly object and

  186382. ** return a pointer to that object.  Or if the input is not a well-formed

  186383. ** polygon, put an error message in sqlite3_context and return NULL.

  186384. */

  186385. static GeoPoly *geopolyFuncParam(

  186386.   sqlite3_context *pCtx,      /* Context for error messages */

  186387.   sqlite3_value *pVal,        /* The value to decode */

  186388.   int *pRc                    /* Write error here */

  186389. ){

  186390.   GeoPoly *p = 0;

  186391.   int nByte;

  186392.   if( sqlite3_value_type(pVal)==SQLITE_BLOB

  186393.    && (nByte = sqlite3_value_bytes(pVal))>=(4+6*sizeof(GeoCoord))

  186394.   ){

  186395.     const unsigned char *a = sqlite3_value_blob(pVal);

  186396.     int nVertex;

  186397.     nVertex = (a[1]<<16) + (a[2]<<8) + a[3];

  186398.     if( (a[0]==0 || a[0]==1)

  186399.      && (nVertex*2*sizeof(GeoCoord) + 4)==(unsigned int)nByte

  186400.     ){

  186401.       p = sqlite3_malloc64( sizeof(*p) + (nVertex-1)*2*sizeof(GeoCoord) );

  186402.       if( p==0 ){

  186403.         if( pRc ) *pRc = SQLITE_NOMEM;

  186404.         if( pCtx ) sqlite3_result_error_nomem(pCtx);

  186405.       }else{

  186406.         int x = 1;

  186407.         p->nVertex = nVertex;

  186408.         memcpy(p->hdr, a, nByte);

  186409.         if( a[0] != *(unsigned char*)&x ){

  186410.           int ii;

  186411.           for(ii=0; ii<nVertex; ii++){

  186412.             geopolySwab32((unsigned char*)&GeoX(p,ii));

  186413.             geopolySwab32((unsigned char*)&GeoY(p,ii));

  186414.           }

  186415.           p->hdr[0] ^= 1;

  186416.         }

  186417.       }

  186418.     }

  186419.     if( pRc ) *pRc = SQLITE_OK;

  186420.     return p;

  186421.   }else if( sqlite3_value_type(pVal)==SQLITE_TEXT ){

  186422.     const unsigned char *zJson = sqlite3_value_text(pVal);

  186423.     if( zJson==0 ){

  186424.       if( pRc ) *pRc = SQLITE_NOMEM;

  186425.       return 0;

  186426.     }

  186427.     return geopolyParseJson(zJson, pRc);

  186428.   }else{

  186429.     if( pRc ) *pRc = SQLITE_ERROR;

  186430.     return 0;

  186431.   }

  186432. }

  186433. 

  186434. /*

  186435. ** Implementation of the geopoly_blob(X) function.

  186436. **

  186437. ** If the input is a well-formed Geopoly BLOB or JSON string

  186438. ** then return the BLOB representation of the polygon.  Otherwise

  186439. ** return NULL.

  186440. */

  186441. static void geopolyBlobFunc(

  186442.   sqlite3_context *context,

  186443.   int argc,

  186444.   sqlite3_value **argv

  186445. ){

  186446.   GeoPoly *p = geopolyFuncParam(context, argv[0], 0);

  186447.   if( p ){

  186448.     sqlite3_result_blob(context, p->hdr, 

  186449.        4+8*p->nVertex, SQLITE_TRANSIENT);

  186450.     sqlite3_free(p);

  186451.   }

  186452. }

  186453. 

  186454. /*

  186455. ** SQL function:     geopoly_json(X)

  186456. **

  186457. ** Interpret X as a polygon and render it as a JSON array

  186458. ** of coordinates.  Or, if X is not a valid polygon, return NULL.

  186459. */

  186460. static void geopolyJsonFunc(

  186461.   sqlite3_context *context,

  186462.   int argc,

  186463.   sqlite3_value **argv

  186464. ){

  186465.   GeoPoly *p = geopolyFuncParam(context, argv[0], 0);

  186466.   if( p ){

  186467.     sqlite3 *db = sqlite3_context_db_handle(context);

  186468.     sqlite3_str *x = sqlite3_str_new(db);

  186469.     int i;

  186470.     sqlite3_str_append(x, "[", 1);

  186471.     for(i=0; i<p->nVertex; i++){

  186472.       sqlite3_str_appendf(x, "[%!g,%!g],", GeoX(p,i), GeoY(p,i));

  186473.     }

  186474.     sqlite3_str_appendf(x, "[%!g,%!g]]", GeoX(p,0), GeoY(p,0));

  186475.     sqlite3_result_text(context, sqlite3_str_finish(x), -1, sqlite3_free);

  186476.     sqlite3_free(p);

  186477.   }

  186478. }

  186479. 

  186480. /*

  186481. ** SQL function:     geopoly_svg(X, ....)

  186482. **

  186483. ** Interpret X as a polygon and render it as a SVG <polyline>.

  186484. ** Additional arguments are added as attributes to the <polyline>.

  186485. */

  186486. static void geopolySvgFunc(

  186487.   sqlite3_context *context,

  186488.   int argc,

  186489.   sqlite3_value **argv

  186490. ){

  186491.   GeoPoly *p;

  186492.   if( argc<1 ) return;

  186493.   p = geopolyFuncParam(context, argv[0], 0);

  186494.   if( p ){

  186495.     sqlite3 *db = sqlite3_context_db_handle(context);

  186496.     sqlite3_str *x = sqlite3_str_new(db);

  186497.     int i;

  186498.     char cSep = '\'';

  186499.     sqlite3_str_appendf(x, "<polyline points=");

  186500.     for(i=0; i<p->nVertex; i++){

  186501.       sqlite3_str_appendf(x, "%c%g,%g", cSep, GeoX(p,i), GeoY(p,i));

  186502.       cSep = ' ';

  186503.     }

  186504.     sqlite3_str_appendf(x, " %g,%g'", GeoX(p,0), GeoY(p,0));

  186505.     for(i=1; i<argc; i++){

  186506.       const char *z = (const char*)sqlite3_value_text(argv[i]);

  186507.       if( z && z[0] ){

  186508.         sqlite3_str_appendf(x, " %s", z);

  186509.       }

  186510.     }

  186511.     sqlite3_str_appendf(x, "></polyline>");

  186512.     sqlite3_result_text(context, sqlite3_str_finish(x), -1, sqlite3_free);

  186513.     sqlite3_free(p);

  186514.   }

  186515. }

  186516. 

  186517. /*

  186518. ** SQL Function:      geopoly_xform(poly, A, B, C, D, E, F)

  186519. **

  186520. ** Transform and/or translate a polygon as follows:

  186521. **

  186522. **      x1 = A*x0 + B*y0 + E

  186523. **      y1 = C*x0 + D*y0 + F

  186524. **

  186525. ** For a translation:

  186526. **

  186527. **      geopoly_xform(poly, 1, 0, 0, 1, x-offset, y-offset)

  186528. **

  186529. ** Rotate by R around the point (0,0):

  186530. **

  186531. **      geopoly_xform(poly, cos(R), sin(R), -sin(R), cos(R), 0, 0)

  186532. */

  186533. static void geopolyXformFunc(

  186534.   sqlite3_context *context,

  186535.   int argc,

  186536.   sqlite3_value **argv

  186537. ){

  186538.   GeoPoly *p = geopolyFuncParam(context, argv[0], 0);

  186539.   double A = sqlite3_value_double(argv[1]);

  186540.   double B = sqlite3_value_double(argv[2]);

  186541.   double C = sqlite3_value_double(argv[3]);

  186542.   double D = sqlite3_value_double(argv[4]);

  186543.   double E = sqlite3_value_double(argv[5]);

  186544.   double F = sqlite3_value_double(argv[6]);

  186545.   GeoCoord x1, y1, x0, y0;

  186546.   int ii;

  186547.   if( p ){

  186548.     for(ii=0; ii<p->nVertex; ii++){

  186549.       x0 = GeoX(p,ii);

  186550.       y0 = GeoY(p,ii);

  186551.       x1 = (GeoCoord)(A*x0 + B*y0 + E);

  186552.       y1 = (GeoCoord)(C*x0 + D*y0 + F);

  186553.       GeoX(p,ii) = x1;

  186554.       GeoY(p,ii) = y1;

  186555.     }

  186556.     sqlite3_result_blob(context, p->hdr, 

  186557.        4+8*p->nVertex, SQLITE_TRANSIENT);

  186558.     sqlite3_free(p);

  186559.   }

  186560. }

  186561. 

  186562. /*

  186563. ** Compute the area enclosed by the polygon.

  186564. **

  186565. ** This routine can also be used to detect polygons that rotate in

  186566. ** the wrong direction.  Polygons are suppose to be counter-clockwise (CCW).

  186567. ** This routine returns a negative value for clockwise (CW) polygons.

  186568. */

  186569. static double geopolyArea(GeoPoly *p){

  186570.   double rArea = 0.0;

  186571.   int ii;

  186572.   for(ii=0; ii<p->nVertex-1; ii++){

  186573.     rArea += (GeoX(p,ii) - GeoX(p,ii+1))           /* (x0 - x1) */

  186574.               * (GeoY(p,ii) + GeoY(p,ii+1))        /* (y0 + y1) */

  186575.               * 0.5;

  186576.   }

  186577.   rArea += (GeoX(p,ii) - GeoX(p,0))                /* (xN - x0) */

  186578.            * (GeoY(p,ii) + GeoY(p,0))              /* (yN + y0) */

  186579.            * 0.5;

  186580.   return rArea;

  186581. }

  186582. 

  186583. /*

  186584. ** Implementation of the geopoly_area(X) function.

  186585. **

  186586. ** If the input is a well-formed Geopoly BLOB then return the area

  186587. ** enclosed by the polygon.  If the polygon circulates clockwise instead

  186588. ** of counterclockwise (as it should) then return the negative of the

  186589. ** enclosed area.  Otherwise return NULL.

  186590. */

  186591. static void geopolyAreaFunc(

  186592.   sqlite3_context *context,

  186593.   int argc,

  186594.   sqlite3_value **argv

  186595. ){

  186596.   GeoPoly *p = geopolyFuncParam(context, argv[0], 0);

  186597.   if( p ){

  186598.     sqlite3_result_double(context, geopolyArea(p));

  186599.     sqlite3_free(p);

  186600.   }            

  186601. }

  186602. 

  186603. /*

  186604. ** Implementation of the geopoly_ccw(X) function.

  186605. **

  186606. ** If the rotation of polygon X is clockwise (incorrect) instead of

  186607. ** counter-clockwise (the correct winding order according to RFC7946)

  186608. ** then reverse the order of the vertexes in polygon X.  

  186609. **

  186610. ** In other words, this routine returns a CCW polygon regardless of the

  186611. ** winding order of its input.

  186612. **

  186613. ** Use this routine to sanitize historical inputs that that sometimes

  186614. ** contain polygons that wind in the wrong direction.

  186615. */

  186616. static void geopolyCcwFunc(

  186617.   sqlite3_context *context,

  186618.   int argc,

  186619.   sqlite3_value **argv

  186620. ){

  186621.   GeoPoly *p = geopolyFuncParam(context, argv[0], 0);

  186622.   if( p ){

  186623.     if( geopolyArea(p)<0.0 ){

  186624.       int ii, jj;

  186625.       for(ii=1, jj=p->nVertex-1; ii<jj; ii++, jj--){

  186626.         GeoCoord t = GeoX(p,ii);

  186627.         GeoX(p,ii) = GeoX(p,jj);

  186628.         GeoX(p,jj) = t;

  186629.         t = GeoY(p,ii);

  186630.         GeoY(p,ii) = GeoY(p,jj);

  186631.         GeoY(p,jj) = t;

  186632.       }

  186633.     }

  186634.     sqlite3_result_blob(context, p->hdr, 

  186635.        4+8*p->nVertex, SQLITE_TRANSIENT);

  186636.     sqlite3_free(p);

  186637.   }            

  186638. }

  186639. 

  186640. #define GEOPOLY_PI 3.1415926535897932385

  186641. 

  186642. /* Fast approximation for sine(X) for X between -0.5*pi and 2*pi

  186643. */

  186644. static double geopolySine(double r){

  186645.   assert( r>=-0.5*GEOPOLY_PI && r<=2.0*GEOPOLY_PI );

  186646.   if( r>=1.5*GEOPOLY_PI ){

  186647.     r -= 2.0*GEOPOLY_PI;

  186648.   }

  186649.   if( r>=0.5*GEOPOLY_PI ){

  186650.     return -geopolySine(r-GEOPOLY_PI);

  186651.   }else{

  186652.     double r2 = r*r;

  186653.     double r3 = r2*r;

  186654.     double r5 = r3*r2;

  186655.     return 0.9996949*r - 0.1656700*r3 + 0.0075134*r5;

  186656.   }

  186657. }

  186658. 

  186659. /*

  186660. ** Function:   geopoly_regular(X,Y,R,N)

  186661. **

  186662. ** Construct a simple, convex, regular polygon centered at X, Y

  186663. ** with circumradius R and with N sides.

  186664. */

  186665. static void geopolyRegularFunc(

  186666.   sqlite3_context *context,

  186667.   int argc,

  186668.   sqlite3_value **argv

  186669. ){

  186670.   double x = sqlite3_value_double(argv[0]);

  186671.   double y = sqlite3_value_double(argv[1]);

  186672.   double r = sqlite3_value_double(argv[2]);

  186673.   int n = sqlite3_value_int(argv[3]);

  186674.   int i;

  186675.   GeoPoly *p;

  186676. 

  186677.   if( n<3 || r<=0.0 ) return;

  186678.   if( n>1000 ) n = 1000;

  186679.   p = sqlite3_malloc64( sizeof(*p) + (n-1)*2*sizeof(GeoCoord) );

  186680.   if( p==0 ){

  186681.     sqlite3_result_error_nomem(context);

  186682.     return;

  186683.   }

  186684.   i = 1;

  186685.   p->hdr[0] = *(unsigned char*)&i;

  186686.   p->hdr[1] = 0;

  186687.   p->hdr[2] = (n>>8)&0xff;

  186688.   p->hdr[3] = n&0xff;

  186689.   for(i=0; i<n; i++){

  186690.     double rAngle = 2.0*GEOPOLY_PI*i/n;

  186691.     GeoX(p,i) = x - r*geopolySine(rAngle-0.5*GEOPOLY_PI);

  186692.     GeoY(p,i) = y + r*geopolySine(rAngle);

  186693.   }

  186694.   sqlite3_result_blob(context, p->hdr, 4+8*n, SQLITE_TRANSIENT);

  186695.   sqlite3_free(p);

  186696. }

  186697. 

  186698. /*

  186699. ** If pPoly is a polygon, compute its bounding box. Then:

  186700. **

  186701. **    (1) if aCoord!=0 store the bounding box in aCoord, returning NULL

  186702. **    (2) otherwise, compute a GeoPoly for the bounding box and return the

  186703. **        new GeoPoly

  186704. **

  186705. ** If pPoly is NULL but aCoord is not NULL, then compute a new GeoPoly from

  186706. ** the bounding box in aCoord and return a pointer to that GeoPoly.

  186707. */

  186708. static GeoPoly *geopolyBBox(

  186709.   sqlite3_context *context,   /* For recording the error */

  186710.   sqlite3_value *pPoly,       /* The polygon */

  186711.   RtreeCoord *aCoord,         /* Results here */

  186712.   int *pRc                    /* Error code here */

  186713. ){

  186714.   GeoPoly *pOut = 0;

  186715.   GeoPoly *p;

  186716.   float mnX, mxX, mnY, mxY;

  186717.   if( pPoly==0 && aCoord!=0 ){

  186718.     p = 0;

  186719.     mnX = aCoord[0].f;

  186720.     mxX = aCoord[1].f;

  186721.     mnY = aCoord[2].f;

  186722.     mxY = aCoord[3].f;

  186723.     goto geopolyBboxFill;

  186724.   }else{

  186725.     p = geopolyFuncParam(context, pPoly, pRc);

  186726.   }

  186727.   if( p ){

  186728.     int ii;

  186729.     mnX = mxX = GeoX(p,0);

  186730.     mnY = mxY = GeoY(p,0);

  186731.     for(ii=1; ii<p->nVertex; ii++){

  186732.       double r = GeoX(p,ii);

  186733.       if( r<mnX ) mnX = (float)r;

  186734.       else if( r>mxX ) mxX = (float)r;

  186735.       r = GeoY(p,ii);

  186736.       if( r<mnY ) mnY = (float)r;

  186737.       else if( r>mxY ) mxY = (float)r;

  186738.     }

  186739.     if( pRc ) *pRc = SQLITE_OK;

  186740.     if( aCoord==0 ){

  186741.       geopolyBboxFill:

  186742.       pOut = sqlite3_realloc64(p, GEOPOLY_SZ(4));

  186743.       if( pOut==0 ){

  186744.         sqlite3_free(p);

  186745.         if( context ) sqlite3_result_error_nomem(context);

  186746.         if( pRc ) *pRc = SQLITE_NOMEM;

  186747.         return 0;

  186748.       }

  186749.       pOut->nVertex = 4;

  186750.       ii = 1;

  186751.       pOut->hdr[0] = *(unsigned char*)&ii;

  186752.       pOut->hdr[1] = 0;

  186753.       pOut->hdr[2] = 0;

  186754.       pOut->hdr[3] = 4;

  186755.       GeoX(pOut,0) = mnX;

  186756.       GeoY(pOut,0) = mnY;

  186757.       GeoX(pOut,1) = mxX;

  186758.       GeoY(pOut,1) = mnY;

  186759.       GeoX(pOut,2) = mxX;

  186760.       GeoY(pOut,2) = mxY;

  186761.       GeoX(pOut,3) = mnX;

  186762.       GeoY(pOut,3) = mxY;

  186763.     }else{

  186764.       sqlite3_free(p);

  186765.       aCoord[0].f = mnX;

  186766.       aCoord[1].f = mxX;

  186767.       aCoord[2].f = mnY;

  186768.       aCoord[3].f = mxY;

  186769.     }

  186770.   }

  186771.   return pOut;

  186772. }

  186773. 

  186774. /*

  186775. ** Implementation of the geopoly_bbox(X) SQL function.

  186776. */

  186777. static void geopolyBBoxFunc(

  186778.   sqlite3_context *context,

  186779.   int argc,

  186780.   sqlite3_value **argv

  186781. ){

  186782.   GeoPoly *p = geopolyBBox(context, argv[0], 0, 0);

  186783.   if( p ){

  186784.     sqlite3_result_blob(context, p->hdr, 

  186785.        4+8*p->nVertex, SQLITE_TRANSIENT);

  186786.     sqlite3_free(p);

  186787.   }

  186788. }

  186789. 

  186790. /*

  186791. ** State vector for the geopoly_group_bbox() aggregate function.

  186792. */

  186793. typedef struct GeoBBox GeoBBox;

  186794. struct GeoBBox {

  186795.   int isInit;

  186796.   RtreeCoord a[4];

  186797. };

  186798. 

  186799. 

  186800. /*

  186801. ** Implementation of the geopoly_group_bbox(X) aggregate SQL function.

  186802. */

  186803. static void geopolyBBoxStep(

  186804.   sqlite3_context *context,

  186805.   int argc,

  186806.   sqlite3_value **argv

  186807. ){

  186808.   RtreeCoord a[4];

  186809.   int rc = SQLITE_OK;

  186810.   (void)geopolyBBox(context, argv[0], a, &rc);

  186811.   if( rc==SQLITE_OK ){

  186812.     GeoBBox *pBBox;

  186813.     pBBox = (GeoBBox*)sqlite3_aggregate_context(context, sizeof(*pBBox));

  186814.     if( pBBox==0 ) return;

  186815.     if( pBBox->isInit==0 ){

  186816.       pBBox->isInit = 1;

  186817.       memcpy(pBBox->a, a, sizeof(RtreeCoord)*4);

  186818.     }else{

  186819.       if( a[0].f < pBBox->a[0].f ) pBBox->a[0] = a[0];

  186820.       if( a[1].f > pBBox->a[1].f ) pBBox->a[1] = a[1];

  186821.       if( a[2].f < pBBox->a[2].f ) pBBox->a[2] = a[2];

  186822.       if( a[3].f > pBBox->a[3].f ) pBBox->a[3] = a[3];

  186823.     }

  186824.   }

  186825. }

  186826. static void geopolyBBoxFinal(

  186827.   sqlite3_context *context

  186828. ){

  186829.   GeoPoly *p;

  186830.   GeoBBox *pBBox;

  186831.   pBBox = (GeoBBox*)sqlite3_aggregate_context(context, 0);

  186832.   if( pBBox==0 ) return;

  186833.   p = geopolyBBox(context, 0, pBBox->a, 0);

  186834.   if( p ){

  186835.     sqlite3_result_blob(context, p->hdr, 

  186836.        4+8*p->nVertex, SQLITE_TRANSIENT);

  186837.     sqlite3_free(p);

  186838.   }

  186839. }

  186840. 

  186841. 

  186842. /*

  186843. ** Determine if point (x0,y0) is beneath line segment (x1,y1)->(x2,y2).

  186844. ** Returns:

  186845. **

  186846. **    +2  x0,y0 is on the line segement

  186847. **

  186848. **    +1  x0,y0 is beneath line segment

  186849. **

  186850. **    0   x0,y0 is not on or beneath the line segment or the line segment

  186851. **        is vertical and x0,y0 is not on the line segment

  186852. **

  186853. ** The left-most coordinate min(x1,x2) is not considered to be part of

  186854. ** the line segment for the purposes of this analysis.

  186855. */

  186856. static int pointBeneathLine(

  186857.   double x0, double y0,

  186858.   double x1, double y1,

  186859.   double x2, double y2

  186860. ){

  186861.   double y;

  186862.   if( x0==x1 && y0==y1 ) return 2;

  186863.   if( x1<x2 ){

  186864.     if( x0<=x1 || x0>x2 ) return 0;

  186865.   }else if( x1>x2 ){

  186866.     if( x0<=x2 || x0>x1 ) return 0;

  186867.   }else{

  186868.     /* Vertical line segment */

  186869.     if( x0!=x1 ) return 0;

  186870.     if( y0<y1 && y0<y2 ) return 0;

  186871.     if( y0>y1 && y0>y2 ) return 0;

  186872.     return 2;

  186873.   }

  186874.   y = y1 + (y2-y1)*(x0-x1)/(x2-x1);

  186875.   if( y0==y ) return 2;

  186876.   if( y0<y ) return 1;

  186877.   return 0;

  186878. }

  186879. 

  186880. /*

  186881. ** SQL function:    geopoly_contains_point(P,X,Y)

  186882. **

  186883. ** Return +2 if point X,Y is within polygon P.

  186884. ** Return +1 if point X,Y is on the polygon boundary.

  186885. ** Return 0 if point X,Y is outside the polygon

  186886. */

  186887. static void geopolyContainsPointFunc(

  186888.   sqlite3_context *context,

  186889.   int argc,

  186890.   sqlite3_value **argv

  186891. ){

  186892.   GeoPoly *p1 = geopolyFuncParam(context, argv[0], 0);

  186893.   double x0 = sqlite3_value_double(argv[1]);

  186894.   double y0 = sqlite3_value_double(argv[2]);

  186895.   int v = 0;

  186896.   int cnt = 0;

  186897.   int ii;

  186898.   if( p1==0 ) return;

  186899.   for(ii=0; ii<p1->nVertex-1; ii++){

  186900.     v = pointBeneathLine(x0,y0,GeoX(p1,ii), GeoY(p1,ii),

  186901.                                GeoX(p1,ii+1),GeoY(p1,ii+1));

  186902.     if( v==2 ) break;

  186903.     cnt += v;

  186904.   }

  186905.   if( v!=2 ){

  186906.     v = pointBeneathLine(x0,y0,GeoX(p1,ii), GeoY(p1,ii),

  186907.                                GeoX(p1,0),  GeoY(p1,0));

  186908.   }

  186909.   if( v==2 ){

  186910.     sqlite3_result_int(context, 1);

  186911.   }else if( ((v+cnt)&1)==0 ){

  186912.     sqlite3_result_int(context, 0);

  186913.   }else{

  186914.     sqlite3_result_int(context, 2);

  186915.   }

  186916.   sqlite3_free(p1);

  186917. }

  186918. 

  186919. /* Forward declaration */

  186920. static int geopolyOverlap(GeoPoly *p1, GeoPoly *p2);

  186921. 

  186922. /*

  186923. ** SQL function:    geopoly_within(P1,P2)

  186924. **

  186925. ** Return +2 if P1 and P2 are the same polygon

  186926. ** Return +1 if P2 is contained within P1

  186927. ** Return 0 if any part of P2 is on the outside of P1

  186928. **

  186929. */

  186930. static void geopolyWithinFunc(

  186931.   sqlite3_context *context,

  186932.   int argc,

  186933.   sqlite3_value **argv

  186934. ){

  186935.   GeoPoly *p1 = geopolyFuncParam(context, argv[0], 0);

  186936.   GeoPoly *p2 = geopolyFuncParam(context, argv[1], 0);

  186937.   if( p1 && p2 ){

  186938.     int x = geopolyOverlap(p1, p2);

  186939.     if( x<0 ){

  186940.       sqlite3_result_error_nomem(context);

  186941.     }else{

  186942.       sqlite3_result_int(context, x==2 ? 1 : x==4 ? 2 : 0);

  186943.     }

  186944.   }

  186945.   sqlite3_free(p1);

  186946.   sqlite3_free(p2);

  186947. }

  186948. 

  186949. /* Objects used by the overlap algorihm. */

  186950. typedef struct GeoEvent GeoEvent;

  186951. typedef struct GeoSegment GeoSegment;

  186952. typedef struct GeoOverlap GeoOverlap;

  186953. struct GeoEvent {

  186954.   double x;              /* X coordinate at which event occurs */

  186955.   int eType;             /* 0 for ADD, 1 for REMOVE */

  186956.   GeoSegment *pSeg;      /* The segment to be added or removed */

  186957.   GeoEvent *pNext;       /* Next event in the sorted list */

  186958. };

  186959. struct GeoSegment {

  186960.   double C, B;           /* y = C*x + B */

  186961.   double y;              /* Current y value */

  186962.   float y0;              /* Initial y value */

  186963.   unsigned char side;    /* 1 for p1, 2 for p2 */

  186964.   unsigned int idx;      /* Which segment within the side */

  186965.   GeoSegment *pNext;     /* Next segment in a list sorted by y */

  186966. };

  186967. struct GeoOverlap {

  186968.   GeoEvent *aEvent;          /* Array of all events */

  186969.   GeoSegment *aSegment;      /* Array of all segments */

  186970.   int nEvent;                /* Number of events */

  186971.   int nSegment;              /* Number of segments */

  186972. };

  186973. 

  186974. /*

  186975. ** Add a single segment and its associated events.

  186976. */

  186977. static void geopolyAddOneSegment(

  186978.   GeoOverlap *p,

  186979.   GeoCoord x0,

  186980.   GeoCoord y0,

  186981.   GeoCoord x1,

  186982.   GeoCoord y1,

  186983.   unsigned char side,

  186984.   unsigned int idx

  186985. ){

  186986.   GeoSegment *pSeg;

  186987.   GeoEvent *pEvent;

  186988.   if( x0==x1 ) return;  /* Ignore vertical segments */

  186989.   if( x0>x1 ){

  186990.     GeoCoord t = x0;

  186991.     x0 = x1;

  186992.     x1 = t;

  186993.     t = y0;

  186994.     y0 = y1;

  186995.     y1 = t;

  186996.   }

  186997.   pSeg = p->aSegment + p->nSegment;

  186998.   p->nSegment++;

  186999.   pSeg->C = (y1-y0)/(x1-x0);

  187000.   pSeg->B = y1 - x1*pSeg->C;

  187001.   pSeg->y0 = y0;

  187002.   pSeg->side = side;

  187003.   pSeg->idx = idx;

  187004.   pEvent = p->aEvent + p->nEvent;

  187005.   p->nEvent++;

  187006.   pEvent->x = x0;

  187007.   pEvent->eType = 0;

  187008.   pEvent->pSeg = pSeg;

  187009.   pEvent = p->aEvent + p->nEvent;

  187010.   p->nEvent++;

  187011.   pEvent->x = x1;

  187012.   pEvent->eType = 1;

  187013.   pEvent->pSeg = pSeg;

  187014. }

  187015.   

  187016. 

  187017. 

  187018. /*

  187019. ** Insert all segments and events for polygon pPoly.

  187020. */

  187021. static void geopolyAddSegments(

  187022.   GeoOverlap *p,          /* Add segments to this Overlap object */

  187023.   GeoPoly *pPoly,         /* Take all segments from this polygon */

  187024.   unsigned char side      /* The side of pPoly */

  187025. ){

  187026.   unsigned int i;

  187027.   GeoCoord *x;

  187028.   for(i=0; i<(unsigned)pPoly->nVertex-1; i++){

  187029.     x = &GeoX(pPoly,i);

  187030.     geopolyAddOneSegment(p, x[0], x[1], x[2], x[3], side, i);

  187031.   }

  187032.   x = &GeoX(pPoly,i);

  187033.   geopolyAddOneSegment(p, x[0], x[1], pPoly->a[0], pPoly->a[1], side, i);

  187034. }

  187035. 

  187036. /*

  187037. ** Merge two lists of sorted events by X coordinate

  187038. */

  187039. static GeoEvent *geopolyEventMerge(GeoEvent *pLeft, GeoEvent *pRight){

  187040.   GeoEvent head, *pLast;

  187041.   head.pNext = 0;

  187042.   pLast = &head;

  187043.   while( pRight && pLeft ){

  187044.     if( pRight->x <= pLeft->x ){

  187045.       pLast->pNext = pRight;

  187046.       pLast = pRight;

  187047.       pRight = pRight->pNext;

  187048.     }else{

  187049.       pLast->pNext = pLeft;

  187050.       pLast = pLeft;

  187051.       pLeft = pLeft->pNext;

  187052.     }

  187053.   }

  187054.   pLast->pNext = pRight ? pRight : pLeft;

  187055.   return head.pNext;  

  187056. }

  187057. 

  187058. /*

  187059. ** Sort an array of nEvent event objects into a list.

  187060. */

  187061. static GeoEvent *geopolySortEventsByX(GeoEvent *aEvent, int nEvent){

  187062.   int mx = 0;

  187063.   int i, j;

  187064.   GeoEvent *p;

  187065.   GeoEvent *a[50];

  187066.   for(i=0; i<nEvent; i++){

  187067.     p = &aEvent[i];

  187068.     p->pNext = 0;

  187069.     for(j=0; j<mx && a[j]; j++){

  187070.       p = geopolyEventMerge(a[j], p);

  187071.       a[j] = 0;

  187072.     }

  187073.     a[j] = p;

  187074.     if( j>=mx ) mx = j+1;

  187075.   }

  187076.   p = 0;

  187077.   for(i=0; i<mx; i++){

  187078.     p = geopolyEventMerge(a[i], p);

  187079.   }

  187080.   return p;

  187081. }

  187082. 

  187083. /*

  187084. ** Merge two lists of sorted segments by Y, and then by C.

  187085. */

  187086. static GeoSegment *geopolySegmentMerge(GeoSegment *pLeft, GeoSegment *pRight){

  187087.   GeoSegment head, *pLast;

  187088.   head.pNext = 0;

  187089.   pLast = &head;

  187090.   while( pRight && pLeft ){

  187091.     double r = pRight->y - pLeft->y;

  187092.     if( r==0.0 ) r = pRight->C - pLeft->C;

  187093.     if( r<0.0 ){

  187094.       pLast->pNext = pRight;

  187095.       pLast = pRight;

  187096.       pRight = pRight->pNext;

  187097.     }else{

  187098.       pLast->pNext = pLeft;

  187099.       pLast = pLeft;

  187100.       pLeft = pLeft->pNext;

  187101.     }

  187102.   }

  187103.   pLast->pNext = pRight ? pRight : pLeft;

  187104.   return head.pNext;  

  187105. }

  187106. 

  187107. /*

  187108. ** Sort a list of GeoSegments in order of increasing Y and in the event of

  187109. ** a tie, increasing C (slope).

  187110. */

  187111. static GeoSegment *geopolySortSegmentsByYAndC(GeoSegment *pList){

  187112.   int mx = 0;

  187113.   int i;

  187114.   GeoSegment *p;

  187115.   GeoSegment *a[50];

  187116.   while( pList ){

  187117.     p = pList;

  187118.     pList = pList->pNext;

  187119.     p->pNext = 0;

  187120.     for(i=0; i<mx && a[i]; i++){

  187121.       p = geopolySegmentMerge(a[i], p);

  187122.       a[i] = 0;

  187123.     }

  187124.     a[i] = p;

  187125.     if( i>=mx ) mx = i+1;

  187126.   }

  187127.   p = 0;

  187128.   for(i=0; i<mx; i++){

  187129.     p = geopolySegmentMerge(a[i], p);

  187130.   }

  187131.   return p;

  187132. }

  187133. 

  187134. /*

  187135. ** Determine the overlap between two polygons

  187136. */

  187137. static int geopolyOverlap(GeoPoly *p1, GeoPoly *p2){

  187138.   sqlite3_int64 nVertex = p1->nVertex + p2->nVertex + 2;

  187139.   GeoOverlap *p;

  187140.   sqlite3_int64 nByte;

  187141.   GeoEvent *pThisEvent;

  187142.   double rX;

  187143.   int rc = 0;

  187144.   int needSort = 0;

  187145.   GeoSegment *pActive = 0;

  187146.   GeoSegment *pSeg;

  187147.   unsigned char aOverlap[4];

  187148. 

  187149.   nByte = sizeof(GeoEvent)*nVertex*2 

  187150.            + sizeof(GeoSegment)*nVertex 

  187151.            + sizeof(GeoOverlap);

  187152.   p = sqlite3_malloc64( nByte );

  187153.   if( p==0 ) return -1;

  187154.   p->aEvent = (GeoEvent*)&p[1];

  187155.   p->aSegment = (GeoSegment*)&p->aEvent[nVertex*2];

  187156.   p->nEvent = p->nSegment = 0;

  187157.   geopolyAddSegments(p, p1, 1);

  187158.   geopolyAddSegments(p, p2, 2);

  187159.   pThisEvent = geopolySortEventsByX(p->aEvent, p->nEvent);

  187160.   rX = pThisEvent->x==0.0 ? -1.0 : 0.0;

  187161.   memset(aOverlap, 0, sizeof(aOverlap));

  187162.   while( pThisEvent ){

  187163.     if( pThisEvent->x!=rX ){

  187164.       GeoSegment *pPrev = 0;

  187165.       int iMask = 0;

  187166.       GEODEBUG(("Distinct X: %g\n", pThisEvent->x));

  187167.       rX = pThisEvent->x;

  187168.       if( needSort ){

  187169.         GEODEBUG(("SORT\n"));

  187170.         pActive = geopolySortSegmentsByYAndC(pActive);

  187171.         needSort = 0;

  187172.       }

  187173.       for(pSeg=pActive; pSeg; pSeg=pSeg->pNext){

  187174.         if( pPrev ){

  187175.           if( pPrev->y!=pSeg->y ){

  187176.             GEODEBUG(("MASK: %d\n", iMask));

  187177.             aOverlap[iMask] = 1;

  187178.           }

  187179.         }

  187180.         iMask ^= pSeg->side;

  187181.         pPrev = pSeg;

  187182.       }

  187183.       pPrev = 0;

  187184.       for(pSeg=pActive; pSeg; pSeg=pSeg->pNext){

  187185.         double y = pSeg->C*rX + pSeg->B;

  187186.         GEODEBUG(("Segment %d.%d %g->%g\n", pSeg->side, pSeg->idx, pSeg->y, y));

  187187.         pSeg->y = y;

  187188.         if( pPrev ){

  187189.           if( pPrev->y>pSeg->y && pPrev->side!=pSeg->side ){

  187190.             rc = 1;

  187191.             GEODEBUG(("Crossing: %d.%d and %d.%d\n",

  187192.                     pPrev->side, pPrev->idx,

  187193.                     pSeg->side, pSeg->idx));

  187194.             goto geopolyOverlapDone;

  187195.           }else if( pPrev->y!=pSeg->y ){

  187196.             GEODEBUG(("MASK: %d\n", iMask));

  187197.             aOverlap[iMask] = 1;

  187198.           }

  187199.         }

  187200.         iMask ^= pSeg->side;

  187201.         pPrev = pSeg;

  187202.       }

  187203.     }

  187204.     GEODEBUG(("%s %d.%d C=%g B=%g\n",

  187205.       pThisEvent->eType ? "RM " : "ADD",

  187206.       pThisEvent->pSeg->side, pThisEvent->pSeg->idx,

  187207.       pThisEvent->pSeg->C,

  187208.       pThisEvent->pSeg->B));

  187209.     if( pThisEvent->eType==0 ){

  187210.       /* Add a segment */

  187211.       pSeg = pThisEvent->pSeg;

  187212.       pSeg->y = pSeg->y0;

  187213.       pSeg->pNext = pActive;

  187214.       pActive = pSeg;

  187215.       needSort = 1;

  187216.     }else{

  187217.       /* Remove a segment */

  187218.       if( pActive==pThisEvent->pSeg ){

  187219.         pActive = pActive->pNext;

  187220.       }else{

  187221.         for(pSeg=pActive; pSeg; pSeg=pSeg->pNext){

  187222.           if( pSeg->pNext==pThisEvent->pSeg ){

  187223.             pSeg->pNext = pSeg->pNext->pNext;

  187224.             break;

  187225.           }

  187226.         }

  187227.       }

  187228.     }

  187229.     pThisEvent = pThisEvent->pNext;

  187230.   }

  187231.   if( aOverlap[3]==0 ){

  187232.     rc = 0;

  187233.   }else if( aOverlap[1]!=0 && aOverlap[2]==0 ){

  187234.     rc = 3;

  187235.   }else if( aOverlap[1]==0 && aOverlap[2]!=0 ){

  187236.     rc = 2;

  187237.   }else if( aOverlap[1]==0 && aOverlap[2]==0 ){

  187238.     rc = 4;

  187239.   }else{

  187240.     rc = 1;

  187241.   }

  187242. 

  187243. geopolyOverlapDone:

  187244.   sqlite3_free(p);

  187245.   return rc;

  187246. }

  187247. 

  187248. /*

  187249. ** SQL function:    geopoly_overlap(P1,P2)

  187250. **

  187251. ** Determine whether or not P1 and P2 overlap. Return value:

  187252. **

  187253. **   0     The two polygons are disjoint

  187254. **   1     They overlap

  187255. **   2     P1 is completely contained within P2

  187256. **   3     P2 is completely contained within P1

  187257. **   4     P1 and P2 are the same polygon

  187258. **   NULL  Either P1 or P2 or both are not valid polygons

  187259. */

  187260. static void geopolyOverlapFunc(

  187261.   sqlite3_context *context,

  187262.   int argc,

  187263.   sqlite3_value **argv

  187264. ){

  187265.   GeoPoly *p1 = geopolyFuncParam(context, argv[0], 0);

  187266.   GeoPoly *p2 = geopolyFuncParam(context, argv[1], 0);

  187267.   if( p1 && p2 ){

  187268.     int x = geopolyOverlap(p1, p2);

  187269.     if( x<0 ){

  187270.       sqlite3_result_error_nomem(context);

  187271.     }else{

  187272.       sqlite3_result_int(context, x);

  187273.     }

  187274.   }

  187275.   sqlite3_free(p1);

  187276.   sqlite3_free(p2);

  187277. }

  187278. 

  187279. /*

  187280. ** Enable or disable debugging output

  187281. */

  187282. static void geopolyDebugFunc(

  187283.   sqlite3_context *context,

  187284.   int argc,

  187285.   sqlite3_value **argv

  187286. ){

  187287. #ifdef GEOPOLY_ENABLE_DEBUG

  187288.   geo_debug = sqlite3_value_int(argv[0]);

  187289. #endif

  187290. }

  187291. 

  187292. /* 

  187293. ** This function is the implementation of both the xConnect and xCreate

  187294. ** methods of the geopoly virtual table.

  187295. **

  187296. **   argv[0]   -> module name

  187297. **   argv[1]   -> database name

  187298. **   argv[2]   -> table name

  187299. **   argv[...] -> column names...

  187300. */

  187301. static int geopolyInit(

  187302.   sqlite3 *db,                        /* Database connection */

  187303.   void *pAux,                         /* One of the RTREE_COORD_* constants */

  187304.   int argc, const char *const*argv,   /* Parameters to CREATE TABLE statement */

  187305.   sqlite3_vtab **ppVtab,              /* OUT: New virtual table */

  187306.   char **pzErr,                       /* OUT: Error message, if any */

  187307.   int isCreate                        /* True for xCreate, false for xConnect */

  187308. ){

  187309.   int rc = SQLITE_OK;

  187310.   Rtree *pRtree;

  187311.   sqlite3_int64 nDb;              /* Length of string argv[1] */

  187312.   sqlite3_int64 nName;            /* Length of string argv[2] */

  187313.   sqlite3_str *pSql;

  187314.   char *zSql;

  187315.   int ii;

  187316. 

  187317.   sqlite3_vtab_config(db, SQLITE_VTAB_CONSTRAINT_SUPPORT, 1);

  187318. 

  187319.   /* Allocate the sqlite3_vtab structure */

  187320.   nDb = strlen(argv[1]);

  187321.   nName = strlen(argv[2]);

  187322.   pRtree = (Rtree *)sqlite3_malloc64(sizeof(Rtree)+nDb+nName+2);

  187323.   if( !pRtree ){

  187324.     return SQLITE_NOMEM;

  187325.   }

  187326.   memset(pRtree, 0, sizeof(Rtree)+nDb+nName+2);

  187327.   pRtree->nBusy = 1;

  187328.   pRtree->base.pModule = &rtreeModule;

  187329.   pRtree->zDb = (char *)&pRtree[1];

  187330.   pRtree->zName = &pRtree->zDb[nDb+1];

  187331.   pRtree->eCoordType = RTREE_COORD_REAL32;

  187332.   pRtree->nDim = 2;

  187333.   pRtree->nDim2 = 4;

  187334.   memcpy(pRtree->zDb, argv[1], nDb);

  187335.   memcpy(pRtree->zName, argv[2], nName);

  187336. 

  187337. 

  187338.   /* Create/Connect to the underlying relational database schema. If

  187339.   ** that is successful, call sqlite3_declare_vtab() to configure

  187340.   ** the r-tree table schema.

  187341.   */

  187342.   pSql = sqlite3_str_new(db);

  187343.   sqlite3_str_appendf(pSql, "CREATE TABLE x(_shape");

  187344.   pRtree->nAux = 1;         /* Add one for _shape */

  187345.   pRtree->nAuxNotNull = 1;  /* The _shape column is always not-null */

  187346.   for(ii=3; ii<argc; ii++){

  187347.     pRtree->nAux++;

  187348.     sqlite3_str_appendf(pSql, ",%s", argv[ii]);

  187349.   }

  187350.   sqlite3_str_appendf(pSql, ");");

  187351.   zSql = sqlite3_str_finish(pSql);

  187352.   if( !zSql ){

  187353.     rc = SQLITE_NOMEM;

  187354.   }else if( SQLITE_OK!=(rc = sqlite3_declare_vtab(db, zSql)) ){

  187355.     *pzErr = sqlite3_mprintf("%s", sqlite3_errmsg(db));

  187356.   }

  187357.   sqlite3_free(zSql);

  187358.   if( rc ) goto geopolyInit_fail;

  187359.   pRtree->nBytesPerCell = 8 + pRtree->nDim2*4;

  187360. 

  187361.   /* Figure out the node size to use. */

  187362.   rc = getNodeSize(db, pRtree, isCreate, pzErr);

  187363.   if( rc ) goto geopolyInit_fail;

  187364.   rc = rtreeSqlInit(pRtree, db, argv[1], argv[2], isCreate);

  187365.   if( rc ){

  187366.     *pzErr = sqlite3_mprintf("%s", sqlite3_errmsg(db));

  187367.     goto geopolyInit_fail;

  187368.   }

  187369. 

  187370.   *ppVtab = (sqlite3_vtab *)pRtree;

  187371.   return SQLITE_OK;

  187372. 

  187373. geopolyInit_fail:

  187374.   if( rc==SQLITE_OK ) rc = SQLITE_ERROR;

  187375.   assert( *ppVtab==0 );

  187376.   assert( pRtree->nBusy==1 );

  187377.   rtreeRelease(pRtree);

  187378.   return rc;

  187379. }

  187380. 

  187381. 

  187382. /* 

  187383. ** GEOPOLY virtual table module xCreate method.

  187384. */

  187385. static int geopolyCreate(

  187386.   sqlite3 *db,

  187387.   void *pAux,

  187388.   int argc, const char *const*argv,

  187389.   sqlite3_vtab **ppVtab,

  187390.   char **pzErr

  187391. ){

  187392.   return geopolyInit(db, pAux, argc, argv, ppVtab, pzErr, 1);

  187393. }

  187394. 

  187395. /* 

  187396. ** GEOPOLY virtual table module xConnect method.

  187397. */

  187398. static int geopolyConnect(

  187399.   sqlite3 *db,

  187400.   void *pAux,

  187401.   int argc, const char *const*argv,

  187402.   sqlite3_vtab **ppVtab,

  187403.   char **pzErr

  187404. ){

  187405.   return geopolyInit(db, pAux, argc, argv, ppVtab, pzErr, 0);

  187406. }

  187407. 

  187408. 

  187409. /* 

  187410. ** GEOPOLY virtual table module xFilter method.

  187411. **

  187412. ** Query plans:

  187413. **

  187414. **      1         rowid lookup

  187415. **      2         search for objects overlapping the same bounding box

  187416. **                that contains polygon argv[0]

  187417. **      3         search for objects overlapping the same bounding box

  187418. **                that contains polygon argv[0]

  187419. **      4         full table scan

  187420. */

  187421. static int geopolyFilter(

  187422.   sqlite3_vtab_cursor *pVtabCursor,     /* The cursor to initialize */

  187423.   int idxNum,                           /* Query plan */

  187424.   const char *idxStr,                   /* Not Used */

  187425.   int argc, sqlite3_value **argv        /* Parameters to the query plan */

  187426. ){

  187427.   Rtree *pRtree = (Rtree *)pVtabCursor->pVtab;

  187428.   RtreeCursor *pCsr = (RtreeCursor *)pVtabCursor;

  187429.   RtreeNode *pRoot = 0;

  187430.   int rc = SQLITE_OK;

  187431.   int iCell = 0;

  187432.   sqlite3_stmt *pStmt;

  187433. 

  187434.   rtreeReference(pRtree);

  187435. 

  187436.   /* Reset the cursor to the same state as rtreeOpen() leaves it in. */

  187437.   freeCursorConstraints(pCsr);

  187438.   sqlite3_free(pCsr->aPoint);

  187439.   pStmt = pCsr->pReadAux;

  187440.   memset(pCsr, 0, sizeof(RtreeCursor));

  187441.   pCsr->base.pVtab = (sqlite3_vtab*)pRtree;

  187442.   pCsr->pReadAux = pStmt;

  187443. 

  187444.   pCsr->iStrategy = idxNum;

  187445.   if( idxNum==1 ){

  187446.     /* Special case - lookup by rowid. */

  187447.     RtreeNode *pLeaf;        /* Leaf on which the required cell resides */

  187448.     RtreeSearchPoint *p;     /* Search point for the leaf */

  187449.     i64 iRowid = sqlite3_value_int64(argv[0]);

  187450.     i64 iNode = 0;

  187451.     rc = findLeafNode(pRtree, iRowid, &pLeaf, &iNode);

  187452.     if( rc==SQLITE_OK && pLeaf!=0 ){

  187453.       p = rtreeSearchPointNew(pCsr, RTREE_ZERO, 0);

  187454.       assert( p!=0 );  /* Always returns pCsr->sPoint */

  187455.       pCsr->aNode[0] = pLeaf;

  187456.       p->id = iNode;

  187457.       p->eWithin = PARTLY_WITHIN;

  187458.       rc = nodeRowidIndex(pRtree, pLeaf, iRowid, &iCell);

  187459.       p->iCell = (u8)iCell;

  187460.       RTREE_QUEUE_TRACE(pCsr, "PUSH-F1:");

  187461.     }else{

  187462.       pCsr->atEOF = 1;

  187463.     }

  187464.   }else{

  187465.     /* Normal case - r-tree scan. Set up the RtreeCursor.aConstraint array 

  187466.     ** with the configured constraints. 

  187467.     */

  187468.     rc = nodeAcquire(pRtree, 1, 0, &pRoot);

  187469.     if( rc==SQLITE_OK && idxNum<=3 ){

  187470.       RtreeCoord bbox[4];

  187471.       RtreeConstraint *p;

  187472.       assert( argc==1 );

  187473.       geopolyBBox(0, argv[0], bbox, &rc);

  187474.       if( rc ){

  187475.         goto geopoly_filter_end;

  187476.       }

  187477.       pCsr->aConstraint = p = sqlite3_malloc(sizeof(RtreeConstraint)*4);

  187478.       pCsr->nConstraint = 4;

  187479.       if( p==0 ){

  187480.         rc = SQLITE_NOMEM;

  187481.       }else{

  187482.         memset(pCsr->aConstraint, 0, sizeof(RtreeConstraint)*4);

  187483.         memset(pCsr->anQueue, 0, sizeof(u32)*(pRtree->iDepth + 1));

  187484.         if( idxNum==2 ){

  187485.           /* Overlap query */

  187486.           p->op = 'B';

  187487.           p->iCoord = 0;

  187488.           p->u.rValue = bbox[1].f;

  187489.           p++;

  187490.           p->op = 'D';

  187491.           p->iCoord = 1;

  187492.           p->u.rValue = bbox[0].f;

  187493.           p++;

  187494.           p->op = 'B';

  187495.           p->iCoord = 2;

  187496.           p->u.rValue = bbox[3].f;

  187497.           p++;

  187498.           p->op = 'D';

  187499.           p->iCoord = 3;

  187500.           p->u.rValue = bbox[2].f;

  187501.         }else{

  187502.           /* Within query */

  187503.           p->op = 'D';

  187504.           p->iCoord = 0;

  187505.           p->u.rValue = bbox[0].f;

  187506.           p++;

  187507.           p->op = 'B';

  187508.           p->iCoord = 1;

  187509.           p->u.rValue = bbox[1].f;

  187510.           p++;

  187511.           p->op = 'D';

  187512.           p->iCoord = 2;

  187513.           p->u.rValue = bbox[2].f;

  187514.           p++;

  187515.           p->op = 'B';

  187516.           p->iCoord = 3;

  187517.           p->u.rValue = bbox[3].f;

  187518.         }

  187519.       }

  187520.     }

  187521.     if( rc==SQLITE_OK ){

  187522.       RtreeSearchPoint *pNew;

  187523.       pNew = rtreeSearchPointNew(pCsr, RTREE_ZERO, (u8)(pRtree->iDepth+1));

  187524.       if( pNew==0 ){

  187525.         rc = SQLITE_NOMEM;

  187526.         goto geopoly_filter_end;

  187527.       }

  187528.       pNew->id = 1;

  187529.       pNew->iCell = 0;

  187530.       pNew->eWithin = PARTLY_WITHIN;

  187531.       assert( pCsr->bPoint==1 );

  187532.       pCsr->aNode[0] = pRoot;

  187533.       pRoot = 0;

  187534.       RTREE_QUEUE_TRACE(pCsr, "PUSH-Fm:");

  187535.       rc = rtreeStepToLeaf(pCsr);

  187536.     }

  187537.   }

  187538. 

  187539. geopoly_filter_end:

  187540.   nodeRelease(pRtree, pRoot);

  187541.   rtreeRelease(pRtree);

  187542.   return rc;

  187543. }

  187544. 

  187545. /*

  187546. ** Rtree virtual table module xBestIndex method. There are three

  187547. ** table scan strategies to choose from (in order from most to 

  187548. ** least desirable):

  187549. **

  187550. **   idxNum     idxStr        Strategy

  187551. **   ------------------------------------------------

  187552. **     1        "rowid"       Direct lookup by rowid.

  187553. **     2        "rtree"       R-tree overlap query using geopoly_overlap()

  187554. **     3        "rtree"       R-tree within query using geopoly_within()

  187555. **     4        "fullscan"    full-table scan.

  187556. **   ------------------------------------------------

  187557. */

  187558. static int geopolyBestIndex(sqlite3_vtab *tab, sqlite3_index_info *pIdxInfo){

  187559.   int ii;

  187560.   int iRowidTerm = -1;

  187561.   int iFuncTerm = -1;

  187562.   int idxNum = 0;

  187563. 

  187564.   for(ii=0; ii<pIdxInfo->nConstraint; ii++){

  187565.     struct sqlite3_index_constraint *p = &pIdxInfo->aConstraint[ii];

  187566.     if( !p->usable ) continue;

  187567.     if( p->iColumn<0 && p->op==SQLITE_INDEX_CONSTRAINT_EQ  ){

  187568.       iRowidTerm = ii;

  187569.       break;

  187570.     }

  187571.     if( p->iColumn==0 && p->op>=SQLITE_INDEX_CONSTRAINT_FUNCTION ){

  187572.       /* p->op==SQLITE_INDEX_CONSTRAINT_FUNCTION for geopoly_overlap()

  187573.       ** p->op==(SQLITE_INDEX_CONTRAINT_FUNCTION+1) for geopoly_within().

  187574.       ** See geopolyFindFunction() */

  187575.       iFuncTerm = ii;

  187576.       idxNum = p->op - SQLITE_INDEX_CONSTRAINT_FUNCTION + 2;

  187577.     }

  187578.   }

  187579. 

  187580.   if( iRowidTerm>=0 ){

  187581.     pIdxInfo->idxNum = 1;

  187582.     pIdxInfo->idxStr = "rowid";

  187583.     pIdxInfo->aConstraintUsage[iRowidTerm].argvIndex = 1;

  187584.     pIdxInfo->aConstraintUsage[iRowidTerm].omit = 1;

  187585.     pIdxInfo->estimatedCost = 30.0;

  187586.     pIdxInfo->estimatedRows = 1;

  187587.     pIdxInfo->idxFlags = SQLITE_INDEX_SCAN_UNIQUE;

  187588.     return SQLITE_OK;

  187589.   }

  187590.   if( iFuncTerm>=0 ){

  187591.     pIdxInfo->idxNum = idxNum;

  187592.     pIdxInfo->idxStr = "rtree";

  187593.     pIdxInfo->aConstraintUsage[iFuncTerm].argvIndex = 1;

  187594.     pIdxInfo->aConstraintUsage[iFuncTerm].omit = 0;

  187595.     pIdxInfo->estimatedCost = 300.0;

  187596.     pIdxInfo->estimatedRows = 10;

  187597.     return SQLITE_OK;

  187598.   }

  187599.   pIdxInfo->idxNum = 4;

  187600.   pIdxInfo->idxStr = "fullscan";

  187601.   pIdxInfo->estimatedCost = 3000000.0;

  187602.   pIdxInfo->estimatedRows = 100000;

  187603.   return SQLITE_OK;

  187604. }

  187605. 

  187606. 

  187607. /* 

  187608. ** GEOPOLY virtual table module xColumn method.

  187609. */

  187610. static int geopolyColumn(sqlite3_vtab_cursor *cur, sqlite3_context *ctx, int i){

  187611.   Rtree *pRtree = (Rtree *)cur->pVtab;

  187612.   RtreeCursor *pCsr = (RtreeCursor *)cur;

  187613.   RtreeSearchPoint *p = rtreeSearchPointFirst(pCsr);

  187614.   int rc = SQLITE_OK;

  187615.   RtreeNode *pNode = rtreeNodeOfFirstSearchPoint(pCsr, &rc);

  187616. 

  187617.   if( rc ) return rc;

  187618.   if( p==0 ) return SQLITE_OK;

  187619.   if( i==0 && sqlite3_vtab_nochange(ctx) ) return SQLITE_OK;

  187620.   if( i<=pRtree->nAux ){

  187621.     if( !pCsr->bAuxValid ){

  187622.       if( pCsr->pReadAux==0 ){

  187623.         rc = sqlite3_prepare_v3(pRtree->db, pRtree->zReadAuxSql, -1, 0,

  187624.                                 &pCsr->pReadAux, 0);

  187625.         if( rc ) return rc;

  187626.       }

  187627.       sqlite3_bind_int64(pCsr->pReadAux, 1, 

  187628.           nodeGetRowid(pRtree, pNode, p->iCell));

  187629.       rc = sqlite3_step(pCsr->pReadAux);

  187630.       if( rc==SQLITE_ROW ){

  187631.         pCsr->bAuxValid = 1;

  187632.       }else{

  187633.         sqlite3_reset(pCsr->pReadAux);

  187634.         if( rc==SQLITE_DONE ) rc = SQLITE_OK;

  187635.         return rc;

  187636.       }

  187637.     }

  187638.     sqlite3_result_value(ctx, sqlite3_column_value(pCsr->pReadAux, i+2));

  187639.   }

  187640.   return SQLITE_OK;

  187641. }

  187642. 

  187643. 

  187644. /*

  187645. ** The xUpdate method for GEOPOLY module virtual tables.

  187646. **

  187647. ** For DELETE:

  187648. **

  187649. **     argv[0] = the rowid to be deleted

  187650. **

  187651. ** For INSERT:

  187652. **

  187653. **     argv[0] = SQL NULL

  187654. **     argv[1] = rowid to insert, or an SQL NULL to select automatically

  187655. **     argv[2] = _shape column

  187656. **     argv[3] = first application-defined column....

  187657. **

  187658. ** For UPDATE:

  187659. **

  187660. **     argv[0] = rowid to modify.  Never NULL

  187661. **     argv[1] = rowid after the change.  Never NULL

  187662. **     argv[2] = new value for _shape

  187663. **     argv[3] = new value for first application-defined column....

  187664. */

  187665. static int geopolyUpdate(

  187666.   sqlite3_vtab *pVtab, 

  187667.   int nData, 

  187668.   sqlite3_value **aData, 

  187669.   sqlite_int64 *pRowid

  187670. ){

  187671.   Rtree *pRtree = (Rtree *)pVtab;

  187672.   int rc = SQLITE_OK;

  187673.   RtreeCell cell;                 /* New cell to insert if nData>1 */

  187674.   i64 oldRowid;                   /* The old rowid */

  187675.   int oldRowidValid;              /* True if oldRowid is valid */

  187676.   i64 newRowid;                   /* The new rowid */

  187677.   int newRowidValid;              /* True if newRowid is valid */

  187678.   int coordChange = 0;            /* Change in coordinates */

  187679. 

  187680.   if( pRtree->nNodeRef ){

  187681.     /* Unable to write to the btree while another cursor is reading from it,

  187682.     ** since the write might do a rebalance which would disrupt the read

  187683.     ** cursor. */

  187684.     return SQLITE_LOCKED_VTAB;

  187685.   }

  187686.   rtreeReference(pRtree);

  187687.   assert(nData>=1);

  187688. 

  187689.   oldRowidValid = sqlite3_value_type(aData[0])!=SQLITE_NULL;;

  187690.   oldRowid = oldRowidValid ? sqlite3_value_int64(aData[0]) : 0;

  187691.   newRowidValid = nData>1 && sqlite3_value_type(aData[1])!=SQLITE_NULL;

  187692.   newRowid = newRowidValid ? sqlite3_value_int64(aData[1]) : 0;

  187693.   cell.iRowid = newRowid;

  187694. 

  187695.   if( nData>1                                 /* not a DELETE */

  187696.    && (!oldRowidValid                         /* INSERT */

  187697.         || !sqlite3_value_nochange(aData[2])  /* UPDATE _shape */

  187698.         || oldRowid!=newRowid)                /* Rowid change */

  187699.   ){

  187700.     geopolyBBox(0, aData[2], cell.aCoord, &rc);

  187701.     if( rc ){

  187702.       if( rc==SQLITE_ERROR ){

  187703.         pVtab->zErrMsg =

  187704.           sqlite3_mprintf("_shape does not contain a valid polygon");

  187705.       }

  187706.       goto geopoly_update_end;

  187707.     }

  187708.     coordChange = 1;

  187709. 

  187710.     /* If a rowid value was supplied, check if it is already present in 

  187711.     ** the table. If so, the constraint has failed. */

  187712.     if( newRowidValid && (!oldRowidValid || oldRowid!=newRowid) ){

  187713.       int steprc;

  187714.       sqlite3_bind_int64(pRtree->pReadRowid, 1, cell.iRowid);

  187715.       steprc = sqlite3_step(pRtree->pReadRowid);

  187716.       rc = sqlite3_reset(pRtree->pReadRowid);

  187717.       if( SQLITE_ROW==steprc ){

  187718.         if( sqlite3_vtab_on_conflict(pRtree->db)==SQLITE_REPLACE ){

  187719.           rc = rtreeDeleteRowid(pRtree, cell.iRowid);

  187720.         }else{

  187721.           rc = rtreeConstraintError(pRtree, 0);

  187722.         }

  187723.       }

  187724.     }

  187725.   }

  187726. 

  187727.   /* If aData[0] is not an SQL NULL value, it is the rowid of a

  187728.   ** record to delete from the r-tree table. The following block does

  187729.   ** just that.

  187730.   */

  187731.   if( rc==SQLITE_OK && (nData==1 || (coordChange && oldRowidValid)) ){

  187732.     rc = rtreeDeleteRowid(pRtree, oldRowid);

  187733.   }

  187734. 

  187735.   /* If the aData[] array contains more than one element, elements

  187736.   ** (aData[2]..aData[argc-1]) contain a new record to insert into

  187737.   ** the r-tree structure.

  187738.   */

  187739.   if( rc==SQLITE_OK && nData>1 && coordChange ){

  187740.     /* Insert the new record into the r-tree */

  187741.     RtreeNode *pLeaf = 0;

  187742.     if( !newRowidValid ){

  187743.       rc = rtreeNewRowid(pRtree, &cell.iRowid);

  187744.     }

  187745.     *pRowid = cell.iRowid;

  187746.     if( rc==SQLITE_OK ){

  187747.       rc = ChooseLeaf(pRtree, &cell, 0, &pLeaf);

  187748.     }

  187749.     if( rc==SQLITE_OK ){

  187750.       int rc2;

  187751.       pRtree->iReinsertHeight = -1;

  187752.       rc = rtreeInsertCell(pRtree, pLeaf, &cell, 0);

  187753.       rc2 = nodeRelease(pRtree, pLeaf);

  187754.       if( rc==SQLITE_OK ){

  187755.         rc = rc2;

  187756.       }

  187757.     }

  187758.   }

  187759. 

  187760.   /* Change the data */

  187761.   if( rc==SQLITE_OK && nData>1 ){

  187762.     sqlite3_stmt *pUp = pRtree->pWriteAux;

  187763.     int jj;

  187764.     int nChange = 0;

  187765.     sqlite3_bind_int64(pUp, 1, cell.iRowid);

  187766.     assert( pRtree->nAux>=1 );

  187767.     if( sqlite3_value_nochange(aData[2]) ){

  187768.       sqlite3_bind_null(pUp, 2);

  187769.     }else{

  187770.       GeoPoly *p = 0;

  187771.       if( sqlite3_value_type(aData[2])==SQLITE_TEXT

  187772.        && (p = geopolyFuncParam(0, aData[2], &rc))!=0

  187773.        && rc==SQLITE_OK

  187774.       ){

  187775.         sqlite3_bind_blob(pUp, 2, p->hdr, 4+8*p->nVertex, SQLITE_TRANSIENT);

  187776.       }else{

  187777.         sqlite3_bind_value(pUp, 2, aData[2]);

  187778.       }

  187779.       sqlite3_free(p);

  187780.       nChange = 1;

  187781.     }

  187782.     for(jj=1; jj<pRtree->nAux; jj++){

  187783.       nChange++;

  187784.       sqlite3_bind_value(pUp, jj+2, aData[jj+2]);

  187785.     }

  187786.     if( nChange ){

  187787.       sqlite3_step(pUp);

  187788.       rc = sqlite3_reset(pUp);

  187789.     }

  187790.   }

  187791. 

  187792. geopoly_update_end:

  187793.   rtreeRelease(pRtree);

  187794.   return rc;

  187795. }

  187796. 

  187797. /*

  187798. ** Report that geopoly_overlap() is an overloaded function suitable

  187799. ** for use in xBestIndex.

  187800. */

  187801. static int geopolyFindFunction(

  187802.   sqlite3_vtab *pVtab,

  187803.   int nArg,

  187804.   const char *zName,

  187805.   void (**pxFunc)(sqlite3_context*,int,sqlite3_value**),

  187806.   void **ppArg

  187807. ){

  187808.   if( sqlite3_stricmp(zName, "geopoly_overlap")==0 ){

  187809.     *pxFunc = geopolyOverlapFunc;

  187810.     *ppArg = 0;

  187811.     return SQLITE_INDEX_CONSTRAINT_FUNCTION;

  187812.   }

  187813.   if( sqlite3_stricmp(zName, "geopoly_within")==0 ){

  187814.     *pxFunc = geopolyWithinFunc;

  187815.     *ppArg = 0;

  187816.     return SQLITE_INDEX_CONSTRAINT_FUNCTION+1;

  187817.   }

  187818.   return 0;

  187819. }

  187820. 

  187821. 

  187822. static sqlite3_module geopolyModule = {

  187823.   3,                          /* iVersion */

  187824.   geopolyCreate,              /* xCreate - create a table */

  187825.   geopolyConnect,             /* xConnect - connect to an existing table */

  187826.   geopolyBestIndex,           /* xBestIndex - Determine search strategy */

  187827.   rtreeDisconnect,            /* xDisconnect - Disconnect from a table */

  187828.   rtreeDestroy,               /* xDestroy - Drop a table */

  187829.   rtreeOpen,                  /* xOpen - open a cursor */

  187830.   rtreeClose,                 /* xClose - close a cursor */

  187831.   geopolyFilter,              /* xFilter - configure scan constraints */

  187832.   rtreeNext,                  /* xNext - advance a cursor */

  187833.   rtreeEof,                   /* xEof */

  187834.   geopolyColumn,              /* xColumn - read data */

  187835.   rtreeRowid,                 /* xRowid - read data */

  187836.   geopolyUpdate,              /* xUpdate - write data */

  187837.   rtreeBeginTransaction,      /* xBegin - begin transaction */

  187838.   rtreeEndTransaction,        /* xSync - sync transaction */

  187839.   rtreeEndTransaction,        /* xCommit - commit transaction */

  187840.   rtreeEndTransaction,        /* xRollback - rollback transaction */

  187841.   geopolyFindFunction,        /* xFindFunction - function overloading */

  187842.   rtreeRename,                /* xRename - rename the table */

  187843.   rtreeSavepoint,             /* xSavepoint */

  187844.   0,                          /* xRelease */

  187845.   0,                          /* xRollbackTo */

  187846.   rtreeShadowName             /* xShadowName */

  187847. };

  187848. 

  187849. static int sqlite3_geopoly_init(sqlite3 *db){

  187850.   int rc = SQLITE_OK;

  187851.   static const struct {

  187852.     void (*xFunc)(sqlite3_context*,int,sqlite3_value**);

  187853.     signed char nArg;

  187854.     unsigned char bPure;

  187855.     const char *zName;

  187856.   } aFunc[] = {

  187857.      { geopolyAreaFunc,          1, 1,    "geopoly_area"             },

  187858.      { geopolyBlobFunc,          1, 1,    "geopoly_blob"             },

  187859.      { geopolyJsonFunc,          1, 1,    "geopoly_json"             },

  187860.      { geopolySvgFunc,          -1, 1,    "geopoly_svg"              },

  187861.      { geopolyWithinFunc,        2, 1,    "geopoly_within"           },

  187862.      { geopolyContainsPointFunc, 3, 1,    "geopoly_contains_point"   },

  187863.      { geopolyOverlapFunc,       2, 1,    "geopoly_overlap"          },

  187864.      { geopolyDebugFunc,         1, 0,    "geopoly_debug"            },

  187865.      { geopolyBBoxFunc,          1, 1,    "geopoly_bbox"             },

  187866.      { geopolyXformFunc,         7, 1,    "geopoly_xform"            },

  187867.      { geopolyRegularFunc,       4, 1,    "geopoly_regular"          },

  187868.      { geopolyCcwFunc,           1, 1,    "geopoly_ccw"              },

  187869.   };

  187870.   static const struct {

  187871.     void (*xStep)(sqlite3_context*,int,sqlite3_value**);

  187872.     void (*xFinal)(sqlite3_context*);

  187873.     const char *zName;

  187874.   } aAgg[] = {

  187875.      { geopolyBBoxStep, geopolyBBoxFinal, "geopoly_group_bbox"    },

  187876.   };

  187877.   int i;

  187878.   for(i=0; i<sizeof(aFunc)/sizeof(aFunc[0]) && rc==SQLITE_OK; i++){

  187879.     int enc = aFunc[i].bPure ? SQLITE_UTF8|SQLITE_DETERMINISTIC : SQLITE_UTF8;

  187880.     rc = sqlite3_create_function(db, aFunc[i].zName, aFunc[i].nArg,

  187881.                                  enc, 0,

  187882.                                  aFunc[i].xFunc, 0, 0);

  187883.   }

  187884.   for(i=0; i<sizeof(aAgg)/sizeof(aAgg[0]) && rc==SQLITE_OK; i++){

  187885.     rc = sqlite3_create_function(db, aAgg[i].zName, 1, SQLITE_UTF8, 0,

  187886.                                  0, aAgg[i].xStep, aAgg[i].xFinal);

  187887.   }

  187888.   if( rc==SQLITE_OK ){

  187889.     rc = sqlite3_create_module_v2(db, "geopoly", &geopolyModule, 0, 0);

  187890.   }

  187891.   return rc;

  187892. }

  187893. 

  187894. /************** End of geopoly.c *********************************************/

  187895. /************** Continuing where we left off in rtree.c **********************/

  187896. #endif

  187897. 

  187898. /*

  187899. ** Register the r-tree module with database handle db. This creates the

  187900. ** virtual table module "rtree" and the debugging/analysis scalar 

  187901. ** function "rtreenode".

  187902. */

  187903. SQLITE_PRIVATE int sqlite3RtreeInit(sqlite3 *db){

  187904.   const int utf8 = SQLITE_UTF8;

  187905.   int rc;

  187906. 

  187907.   rc = sqlite3_create_function(db, "rtreenode", 2, utf8, 0, rtreenode, 0, 0);

  187908.   if( rc==SQLITE_OK ){

  187909.     rc = sqlite3_create_function(db, "rtreedepth", 1, utf8, 0,rtreedepth, 0, 0);

  187910.   }

  187911.   if( rc==SQLITE_OK ){

  187912.     rc = sqlite3_create_function(db, "rtreecheck", -1, utf8, 0,rtreecheck, 0,0);

  187913.   }

  187914.   if( rc==SQLITE_OK ){

  187915. #ifdef SQLITE_RTREE_INT_ONLY

  187916.     void *c = (void *)RTREE_COORD_INT32;

  187917. #else

  187918.     void *c = (void *)RTREE_COORD_REAL32;

  187919. #endif

  187920.     rc = sqlite3_create_module_v2(db, "rtree", &rtreeModule, c, 0);

  187921.   }

  187922.   if( rc==SQLITE_OK ){

  187923.     void *c = (void *)RTREE_COORD_INT32;

  187924.     rc = sqlite3_create_module_v2(db, "rtree_i32", &rtreeModule, c, 0);

  187925.   }

  187926. #ifdef SQLITE_ENABLE_GEOPOLY

  187927.   if( rc==SQLITE_OK ){

  187928.     rc = sqlite3_geopoly_init(db);

  187929.   }

  187930. #endif

  187931. 

  187932.   return rc;

  187933. }

  187934. 

  187935. /*

  187936. ** This routine deletes the RtreeGeomCallback object that was attached

  187937. ** one of the SQL functions create by sqlite3_rtree_geometry_callback()

  187938. ** or sqlite3_rtree_query_callback().  In other words, this routine is the

  187939. ** destructor for an RtreeGeomCallback objecct.  This routine is called when

  187940. ** the corresponding SQL function is deleted.

  187941. */

  187942. static void rtreeFreeCallback(void *p){

  187943.   RtreeGeomCallback *pInfo = (RtreeGeomCallback*)p;

  187944.   if( pInfo->xDestructor ) pInfo->xDestructor(pInfo->pContext);

  187945.   sqlite3_free(p);

  187946. }

  187947. 

  187948. /*

  187949. ** This routine frees the BLOB that is returned by geomCallback().

  187950. */

  187951. static void rtreeMatchArgFree(void *pArg){

  187952.   int i;

  187953.   RtreeMatchArg *p = (RtreeMatchArg*)pArg;

  187954.   for(i=0; i<p->nParam; i++){

  187955.     sqlite3_value_free(p->apSqlParam[i]);

  187956.   }

  187957.   sqlite3_free(p);

  187958. }

  187959. 

  187960. /*

  187961. ** Each call to sqlite3_rtree_geometry_callback() or

  187962. ** sqlite3_rtree_query_callback() creates an ordinary SQLite

  187963. ** scalar function that is implemented by this routine.

  187964. **

  187965. ** All this function does is construct an RtreeMatchArg object that

  187966. ** contains the geometry-checking callback routines and a list of

  187967. ** parameters to this function, then return that RtreeMatchArg object

  187968. ** as a BLOB.

  187969. **

  187970. ** The R-Tree MATCH operator will read the returned BLOB, deserialize

  187971. ** the RtreeMatchArg object, and use the RtreeMatchArg object to figure

  187972. ** out which elements of the R-Tree should be returned by the query.

  187973. */

  187974. static void geomCallback(sqlite3_context *ctx, int nArg, sqlite3_value **aArg){

  187975.   RtreeGeomCallback *pGeomCtx = (RtreeGeomCallback *)sqlite3_user_data(ctx);

  187976.   RtreeMatchArg *pBlob;

  187977.   sqlite3_int64 nBlob;

  187978.   int memErr = 0;

  187979. 

  187980.   nBlob = sizeof(RtreeMatchArg) + (nArg-1)*sizeof(RtreeDValue)

  187981.            + nArg*sizeof(sqlite3_value*);

  187982.   pBlob = (RtreeMatchArg *)sqlite3_malloc64(nBlob);

  187983.   if( !pBlob ){

  187984.     sqlite3_result_error_nomem(ctx);

  187985.   }else{

  187986.     int i;

  187987.     pBlob->iSize = nBlob;

  187988.     pBlob->cb = pGeomCtx[0];

  187989.     pBlob->apSqlParam = (sqlite3_value**)&pBlob->aParam[nArg];

  187990.     pBlob->nParam = nArg;

  187991.     for(i=0; i<nArg; i++){

  187992.       pBlob->apSqlParam[i] = sqlite3_value_dup(aArg[i]);

  187993.       if( pBlob->apSqlParam[i]==0 ) memErr = 1;

  187994. #ifdef SQLITE_RTREE_INT_ONLY

  187995.       pBlob->aParam[i] = sqlite3_value_int64(aArg[i]);

  187996. #else

  187997.       pBlob->aParam[i] = sqlite3_value_double(aArg[i]);

  187998. #endif

  187999.     }

  188000.     if( memErr ){

  188001.       sqlite3_result_error_nomem(ctx);

  188002.       rtreeMatchArgFree(pBlob);

  188003.     }else{

  188004.       sqlite3_result_pointer(ctx, pBlob, "RtreeMatchArg", rtreeMatchArgFree);

  188005.     }

  188006.   }

  188007. }

  188008. 

  188009. /*

  188010. ** Register a new geometry function for use with the r-tree MATCH operator.

  188011. */

  188012. SQLITE_API int sqlite3_rtree_geometry_callback(

  188013.   sqlite3 *db,                  /* Register SQL function on this connection */

  188014.   const char *zGeom,            /* Name of the new SQL function */

  188015.   int (*xGeom)(sqlite3_rtree_geometry*,int,RtreeDValue*,int*), /* Callback */

  188016.   void *pContext                /* Extra data associated with the callback */

  188017. ){

  188018.   RtreeGeomCallback *pGeomCtx;      /* Context object for new user-function */

  188019. 

  188020.   /* Allocate and populate the context object. */

  188021.   pGeomCtx = (RtreeGeomCallback *)sqlite3_malloc(sizeof(RtreeGeomCallback));

  188022.   if( !pGeomCtx ) return SQLITE_NOMEM;

  188023.   pGeomCtx->xGeom = xGeom;

  188024.   pGeomCtx->xQueryFunc = 0;

  188025.   pGeomCtx->xDestructor = 0;

  188026.   pGeomCtx->pContext = pContext;

  188027.   return sqlite3_create_function_v2(db, zGeom, -1, SQLITE_ANY, 

  188028.       (void *)pGeomCtx, geomCallback, 0, 0, rtreeFreeCallback

  188029.   );

  188030. }

  188031. 

  188032. /*

  188033. ** Register a new 2nd-generation geometry function for use with the

  188034. ** r-tree MATCH operator.

  188035. */

  188036. SQLITE_API int sqlite3_rtree_query_callback(

  188037.   sqlite3 *db,                 /* Register SQL function on this connection */

  188038.   const char *zQueryFunc,      /* Name of new SQL function */

  188039.   int (*xQueryFunc)(sqlite3_rtree_query_info*), /* Callback */

  188040.   void *pContext,              /* Extra data passed into the callback */

  188041.   void (*xDestructor)(void*)   /* Destructor for the extra data */

  188042. ){

  188043.   RtreeGeomCallback *pGeomCtx;      /* Context object for new user-function */

  188044. 

  188045.   /* Allocate and populate the context object. */

  188046.   pGeomCtx = (RtreeGeomCallback *)sqlite3_malloc(sizeof(RtreeGeomCallback));

  188047.   if( !pGeomCtx ) return SQLITE_NOMEM;

  188048.   pGeomCtx->xGeom = 0;

  188049.   pGeomCtx->xQueryFunc = xQueryFunc;

  188050.   pGeomCtx->xDestructor = xDestructor;

  188051.   pGeomCtx->pContext = pContext;

  188052.   return sqlite3_create_function_v2(db, zQueryFunc, -1, SQLITE_ANY, 

  188053.       (void *)pGeomCtx, geomCallback, 0, 0, rtreeFreeCallback

  188054.   );

  188055. }

  188056. 

  188057. #if !SQLITE_CORE

  188058. #ifdef _WIN32

  188059. __declspec(dllexport)

  188060. #endif

  188061. SQLITE_API int sqlite3_rtree_init(

  188062.   sqlite3 *db,

  188063.   char **pzErrMsg,

  188064.   const sqlite3_api_routines *pApi

  188065. ){

  188066.   SQLITE_EXTENSION_INIT2(pApi)

  188067.   return sqlite3RtreeInit(db);

  188068. }

  188069. #endif

  188070. 

  188071. #endif

  188072. 

  188073. /************** End of rtree.c ***********************************************/

  188074. /************** Begin file icu.c *********************************************/

  188075. /*

  188076. ** 2007 May 6

  188077. **

  188078. ** The author disclaims copyright to this source code.  In place of

  188079. ** a legal notice, here is a blessing:

  188080. **

  188081. **    May you do good and not evil.

  188082. **    May you find forgiveness for yourself and forgive others.

  188083. **    May you share freely, never taking more than you give.

  188084. **

  188085. *************************************************************************

  188086. ** $Id: icu.c,v 1.7 2007/12/13 21:54:11 drh Exp $

  188087. **

  188088. ** This file implements an integration between the ICU library 

  188089. ** ("International Components for Unicode", an open-source library 

  188090. ** for handling unicode data) and SQLite. The integration uses 

  188091. ** ICU to provide the following to SQLite:

  188092. **

  188093. **   * An implementation of the SQL regexp() function (and hence REGEXP

  188094. **     operator) using the ICU uregex_XX() APIs.

  188095. **

  188096. **   * Implementations of the SQL scalar upper() and lower() functions

  188097. **     for case mapping.

  188098. **

  188099. **   * Integration of ICU and SQLite collation sequences.

  188100. **

  188101. **   * An implementation of the LIKE operator that uses ICU to 

  188102. **     provide case-independent matching.

  188103. */

  188104. 

  188105. #if !defined(SQLITE_CORE)                  \

  188106.  || defined(SQLITE_ENABLE_ICU)             \

  188107.  || defined(SQLITE_ENABLE_ICU_COLLATIONS)

  188108. 

  188109. /* Include ICU headers */

  188110. #include <unicode/utypes.h>

  188111. #include <unicode/uregex.h>

  188112. #include <unicode/ustring.h>

  188113. #include <unicode/ucol.h>

  188114. 

  188115. /* #include <assert.h> */

  188116. 

  188117. #ifndef SQLITE_CORE

  188118. /*   #include "sqlite3ext.h" */

  188119.   SQLITE_EXTENSION_INIT1

  188120. #else

  188121. /*   #include "sqlite3.h" */

  188122. #endif

  188123. 

  188124. /*

  188125. ** This function is called when an ICU function called from within

  188126. ** the implementation of an SQL scalar function returns an error.

  188127. **

  188128. ** The scalar function context passed as the first argument is 

  188129. ** loaded with an error message based on the following two args.

  188130. */

  188131. static void icuFunctionError(

  188132.   sqlite3_context *pCtx,       /* SQLite scalar function context */

  188133.   const char *zName,           /* Name of ICU function that failed */

  188134.   UErrorCode e                 /* Error code returned by ICU function */

  188135. ){

  188136.   char zBuf[128];

  188137.   sqlite3_snprintf(128, zBuf, "ICU error: %s(): %s", zName, u_errorName(e));

  188138.   zBuf[127] = '\0';

  188139.   sqlite3_result_error(pCtx, zBuf, -1);

  188140. }

  188141. 

  188142. #if !defined(SQLITE_CORE) || defined(SQLITE_ENABLE_ICU)

  188143. 

  188144. /*

  188145. ** Maximum length (in bytes) of the pattern in a LIKE or GLOB

  188146. ** operator.

  188147. */

  188148. #ifndef SQLITE_MAX_LIKE_PATTERN_LENGTH

  188149. # define SQLITE_MAX_LIKE_PATTERN_LENGTH 50000

  188150. #endif

  188151. 

  188152. /*

  188153. ** Version of sqlite3_free() that is always a function, never a macro.

  188154. */

  188155. static void xFree(void *p){

  188156.   sqlite3_free(p);

  188157. }

  188158. 

  188159. /*

  188160. ** This lookup table is used to help decode the first byte of

  188161. ** a multi-byte UTF8 character. It is copied here from SQLite source

  188162. ** code file utf8.c.

  188163. */

  188164. static const unsigned char icuUtf8Trans1[] = {

  188165.   0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07,

  188166.   0x08, 0x09, 0x0a, 0x0b, 0x0c, 0x0d, 0x0e, 0x0f,

  188167.   0x10, 0x11, 0x12, 0x13, 0x14, 0x15, 0x16, 0x17,

  188168.   0x18, 0x19, 0x1a, 0x1b, 0x1c, 0x1d, 0x1e, 0x1f,

  188169.   0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07,

  188170.   0x08, 0x09, 0x0a, 0x0b, 0x0c, 0x0d, 0x0e, 0x0f,

  188171.   0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07,

  188172.   0x00, 0x01, 0x02, 0x03, 0x00, 0x01, 0x00, 0x00,

  188173. };

  188174. 

  188175. #define SQLITE_ICU_READ_UTF8(zIn, c)                       \

  188176.   c = *(zIn++);                                            \

  188177.   if( c>=0xc0 ){                                           \

  188178.     c = icuUtf8Trans1[c-0xc0];                             \

  188179.     while( (*zIn & 0xc0)==0x80 ){                          \

  188180.       c = (c<<6) + (0x3f & *(zIn++));                      \

  188181.     }                                                      \

  188182.   }

  188183. 

  188184. #define SQLITE_ICU_SKIP_UTF8(zIn)                          \

  188185.   assert( *zIn );                                          \

  188186.   if( *(zIn++)>=0xc0 ){                                    \

  188187.     while( (*zIn & 0xc0)==0x80 ){zIn++;}                   \

  188188.   }

  188189. 

  188190. 

  188191. /*

  188192. ** Compare two UTF-8 strings for equality where the first string is

  188193. ** a "LIKE" expression. Return true (1) if they are the same and 

  188194. ** false (0) if they are different.

  188195. */

  188196. static int icuLikeCompare(

  188197.   const uint8_t *zPattern,   /* LIKE pattern */

  188198.   const uint8_t *zString,    /* The UTF-8 string to compare against */

  188199.   const UChar32 uEsc         /* The escape character */

  188200. ){

  188201.   static const uint32_t MATCH_ONE = (uint32_t)'_';

  188202.   static const uint32_t MATCH_ALL = (uint32_t)'%';

  188203. 

  188204.   int prevEscape = 0;     /* True if the previous character was uEsc */

  188205. 

  188206.   while( 1 ){

  188207. 

  188208.     /* Read (and consume) the next character from the input pattern. */

  188209.     uint32_t uPattern;

  188210.     SQLITE_ICU_READ_UTF8(zPattern, uPattern);

  188211.     if( uPattern==0 ) break;

  188212. 

  188213.     /* There are now 4 possibilities:

  188214.     **

  188215.     **     1. uPattern is an unescaped match-all character "%",

  188216.     **     2. uPattern is an unescaped match-one character "_",

  188217.     **     3. uPattern is an unescaped escape character, or

  188218.     **     4. uPattern is to be handled as an ordinary character

  188219.     */

  188220.     if( !prevEscape && uPattern==MATCH_ALL ){

  188221.       /* Case 1. */

  188222.       uint8_t c;

  188223. 

  188224.       /* Skip any MATCH_ALL or MATCH_ONE characters that follow a

  188225.       ** MATCH_ALL. For each MATCH_ONE, skip one character in the 

  188226.       ** test string.

  188227.       */

  188228.       while( (c=*zPattern) == MATCH_ALL || c == MATCH_ONE ){

  188229.         if( c==MATCH_ONE ){

  188230.           if( *zString==0 ) return 0;

  188231.           SQLITE_ICU_SKIP_UTF8(zString);

  188232.         }

  188233.         zPattern++;

  188234.       }

  188235. 

  188236.       if( *zPattern==0 ) return 1;

  188237. 

  188238.       while( *zString ){

  188239.         if( icuLikeCompare(zPattern, zString, uEsc) ){

  188240.           return 1;

  188241.         }

  188242.         SQLITE_ICU_SKIP_UTF8(zString);

  188243.       }

  188244.       return 0;

  188245. 

  188246.     }else if( !prevEscape && uPattern==MATCH_ONE ){

  188247.       /* Case 2. */

  188248.       if( *zString==0 ) return 0;

  188249.       SQLITE_ICU_SKIP_UTF8(zString);

  188250. 

  188251.     }else if( !prevEscape && uPattern==(uint32_t)uEsc){

  188252.       /* Case 3. */

  188253.       prevEscape = 1;

  188254. 

  188255.     }else{

  188256.       /* Case 4. */

  188257.       uint32_t uString;

  188258.       SQLITE_ICU_READ_UTF8(zString, uString);

  188259.       uString = (uint32_t)u_foldCase((UChar32)uString, U_FOLD_CASE_DEFAULT);

  188260.       uPattern = (uint32_t)u_foldCase((UChar32)uPattern, U_FOLD_CASE_DEFAULT);

  188261.       if( uString!=uPattern ){

  188262.         return 0;

  188263.       }

  188264.       prevEscape = 0;

  188265.     }

  188266.   }

  188267. 

  188268.   return *zString==0;

  188269. }

  188270. 

  188271. /*

  188272. ** Implementation of the like() SQL function.  This function implements

  188273. ** the build-in LIKE operator.  The first argument to the function is the

  188274. ** pattern and the second argument is the string.  So, the SQL statements:

  188275. **

  188276. **       A LIKE B

  188277. **

  188278. ** is implemented as like(B, A). If there is an escape character E, 

  188279. **

  188280. **       A LIKE B ESCAPE E

  188281. **

  188282. ** is mapped to like(B, A, E).

  188283. */

  188284. static void icuLikeFunc(

  188285.   sqlite3_context *context, 

  188286.   int argc, 

  188287.   sqlite3_value **argv

  188288. ){

  188289.   const unsigned char *zA = sqlite3_value_text(argv[0]);

  188290.   const unsigned char *zB = sqlite3_value_text(argv[1]);

  188291.   UChar32 uEsc = 0;

  188292. 

  188293.   /* Limit the length of the LIKE or GLOB pattern to avoid problems

  188294.   ** of deep recursion and N*N behavior in patternCompare().

  188295.   */

  188296.   if( sqlite3_value_bytes(argv[0])>SQLITE_MAX_LIKE_PATTERN_LENGTH ){

  188297.     sqlite3_result_error(context, "LIKE or GLOB pattern too complex", -1);

  188298.     return;

  188299.   }

  188300. 

  188301. 

  188302.   if( argc==3 ){

  188303.     /* The escape character string must consist of a single UTF-8 character.

  188304.     ** Otherwise, return an error.

  188305.     */

  188306.     int nE= sqlite3_value_bytes(argv[2]);

  188307.     const unsigned char *zE = sqlite3_value_text(argv[2]);

  188308.     int i = 0;

  188309.     if( zE==0 ) return;

  188310.     U8_NEXT(zE, i, nE, uEsc);

  188311.     if( i!=nE){

  188312.       sqlite3_result_error(context, 

  188313.           "ESCAPE expression must be a single character", -1);

  188314.       return;

  188315.     }

  188316.   }

  188317. 

  188318.   if( zA && zB ){

  188319.     sqlite3_result_int(context, icuLikeCompare(zA, zB, uEsc));

  188320.   }

  188321. }

  188322. 

  188323. /*

  188324. ** Function to delete compiled regexp objects. Registered as

  188325. ** a destructor function with sqlite3_set_auxdata().

  188326. */

  188327. static void icuRegexpDelete(void *p){

  188328.   URegularExpression *pExpr = (URegularExpression *)p;

  188329.   uregex_close(pExpr);

  188330. }

  188331. 

  188332. /*

  188333. ** Implementation of SQLite REGEXP operator. This scalar function takes

  188334. ** two arguments. The first is a regular expression pattern to compile

  188335. ** the second is a string to match against that pattern. If either 

  188336. ** argument is an SQL NULL, then NULL Is returned. Otherwise, the result

  188337. ** is 1 if the string matches the pattern, or 0 otherwise.

  188338. **

  188339. ** SQLite maps the regexp() function to the regexp() operator such

  188340. ** that the following two are equivalent:

  188341. **

  188342. **     zString REGEXP zPattern

  188343. **     regexp(zPattern, zString)

  188344. **

  188345. ** Uses the following ICU regexp APIs:

  188346. **

  188347. **     uregex_open()

  188348. **     uregex_matches()

  188349. **     uregex_close()

  188350. */

  188351. static void icuRegexpFunc(sqlite3_context *p, int nArg, sqlite3_value **apArg){

  188352.   UErrorCode status = U_ZERO_ERROR;

  188353.   URegularExpression *pExpr;

  188354.   UBool res;

  188355.   const UChar *zString = sqlite3_value_text16(apArg[1]);

  188356. 

  188357.   (void)nArg;  /* Unused parameter */

  188358. 

  188359.   /* If the left hand side of the regexp operator is NULL, 

  188360.   ** then the result is also NULL. 

  188361.   */

  188362.   if( !zString ){

  188363.     return;

  188364.   }

  188365. 

  188366.   pExpr = sqlite3_get_auxdata(p, 0);

  188367.   if( !pExpr ){

  188368.     const UChar *zPattern = sqlite3_value_text16(apArg[0]);

  188369.     if( !zPattern ){

  188370.       return;

  188371.     }

  188372.     pExpr = uregex_open(zPattern, -1, 0, 0, &status);

  188373. 

  188374.     if( U_SUCCESS(status) ){

  188375.       sqlite3_set_auxdata(p, 0, pExpr, icuRegexpDelete);

  188376.     }else{

  188377.       assert(!pExpr);

  188378.       icuFunctionError(p, "uregex_open", status);

  188379.       return;

  188380.     }

  188381.   }

  188382. 

  188383.   /* Configure the text that the regular expression operates on. */

  188384.   uregex_setText(pExpr, zString, -1, &status);

  188385.   if( !U_SUCCESS(status) ){

  188386.     icuFunctionError(p, "uregex_setText", status);

  188387.     return;

  188388.   }

  188389. 

  188390.   /* Attempt the match */

  188391.   res = uregex_matches(pExpr, 0, &status);

  188392.   if( !U_SUCCESS(status) ){

  188393.     icuFunctionError(p, "uregex_matches", status);

  188394.     return;

  188395.   }

  188396. 

  188397.   /* Set the text that the regular expression operates on to a NULL

  188398.   ** pointer. This is not really necessary, but it is tidier than 

  188399.   ** leaving the regular expression object configured with an invalid

  188400.   ** pointer after this function returns.

  188401.   */

  188402.   uregex_setText(pExpr, 0, 0, &status);

  188403. 

  188404.   /* Return 1 or 0. */

  188405.   sqlite3_result_int(p, res ? 1 : 0);

  188406. }

  188407. 

  188408. /*

  188409. ** Implementations of scalar functions for case mapping - upper() and 

  188410. ** lower(). Function upper() converts its input to upper-case (ABC).

  188411. ** Function lower() converts to lower-case (abc).

  188412. **

  188413. ** ICU provides two types of case mapping, "general" case mapping and

  188414. ** "language specific". Refer to ICU documentation for the differences

  188415. ** between the two.

  188416. **

  188417. ** To utilise "general" case mapping, the upper() or lower() scalar 

  188418. ** functions are invoked with one argument:

  188419. **

  188420. **     upper('ABC') -> 'abc'

  188421. **     lower('abc') -> 'ABC'

  188422. **

  188423. ** To access ICU "language specific" case mapping, upper() or lower()

  188424. ** should be invoked with two arguments. The second argument is the name

  188425. ** of the locale to use. Passing an empty string ("") or SQL NULL value

  188426. ** as the second argument is the same as invoking the 1 argument version

  188427. ** of upper() or lower().

  188428. **

  188429. **     lower('I', 'en_us') -> 'i'

  188430. **     lower('I', 'tr_tr') -> '\u131' (small dotless i)

  188431. **

  188432. ** http://www.icu-project.org/userguide/posix.html#case_mappings

  188433. */

  188434. static void icuCaseFunc16(sqlite3_context *p, int nArg, sqlite3_value **apArg){

  188435.   const UChar *zInput;            /* Pointer to input string */

  188436.   UChar *zOutput = 0;             /* Pointer to output buffer */

  188437.   int nInput;                     /* Size of utf-16 input string in bytes */

  188438.   int nOut;                       /* Size of output buffer in bytes */

  188439.   int cnt;

  188440.   int bToUpper;                   /* True for toupper(), false for tolower() */

  188441.   UErrorCode status;

  188442.   const char *zLocale = 0;

  188443. 

  188444.   assert(nArg==1 || nArg==2);

  188445.   bToUpper = (sqlite3_user_data(p)!=0);

  188446.   if( nArg==2 ){

  188447.     zLocale = (const char *)sqlite3_value_text(apArg[1]);

  188448.   }

  188449. 

  188450.   zInput = sqlite3_value_text16(apArg[0]);

  188451.   if( !zInput ){

  188452.     return;

  188453.   }

  188454.   nOut = nInput = sqlite3_value_bytes16(apArg[0]);

  188455.   if( nOut==0 ){

  188456.     sqlite3_result_text16(p, "", 0, SQLITE_STATIC);

  188457.     return;

  188458.   }

  188459. 

  188460.   for(cnt=0; cnt<2; cnt++){

  188461.     UChar *zNew = sqlite3_realloc(zOutput, nOut);

  188462.     if( zNew==0 ){

  188463.       sqlite3_free(zOutput);

  188464.       sqlite3_result_error_nomem(p);

  188465.       return;

  188466.     }

  188467.     zOutput = zNew;

  188468.     status = U_ZERO_ERROR;

  188469.     if( bToUpper ){

  188470.       nOut = 2*u_strToUpper(zOutput,nOut/2,zInput,nInput/2,zLocale,&status);

  188471.     }else{

  188472.       nOut = 2*u_strToLower(zOutput,nOut/2,zInput,nInput/2,zLocale,&status);

  188473.     }

  188474. 

  188475.     if( U_SUCCESS(status) ){

  188476.       sqlite3_result_text16(p, zOutput, nOut, xFree);

  188477.     }else if( status==U_BUFFER_OVERFLOW_ERROR ){

  188478.       assert( cnt==0 );

  188479.       continue;

  188480.     }else{

  188481.       icuFunctionError(p, bToUpper ? "u_strToUpper" : "u_strToLower", status);

  188482.     }

  188483.     return;

  188484.   }

  188485.   assert( 0 );     /* Unreachable */

  188486. }

  188487. 

  188488. #endif /* !defined(SQLITE_CORE) || defined(SQLITE_ENABLE_ICU) */

  188489. 

  188490. /*

  188491. ** Collation sequence destructor function. The pCtx argument points to

  188492. ** a UCollator structure previously allocated using ucol_open().

  188493. */

  188494. static void icuCollationDel(void *pCtx){

  188495.   UCollator *p = (UCollator *)pCtx;

  188496.   ucol_close(p);

  188497. }

  188498. 

  188499. /*

  188500. ** Collation sequence comparison function. The pCtx argument points to

  188501. ** a UCollator structure previously allocated using ucol_open().

  188502. */

  188503. static int icuCollationColl(

  188504.   void *pCtx,

  188505.   int nLeft,

  188506.   const void *zLeft,

  188507.   int nRight,

  188508.   const void *zRight

  188509. ){

  188510.   UCollationResult res;

  188511.   UCollator *p = (UCollator *)pCtx;

  188512.   res = ucol_strcoll(p, (UChar *)zLeft, nLeft/2, (UChar *)zRight, nRight/2);

  188513.   switch( res ){

  188514.     case UCOL_LESS:    return -1;

  188515.     case UCOL_GREATER: return +1;

  188516.     case UCOL_EQUAL:   return 0;

  188517.   }

  188518.   assert(!"Unexpected return value from ucol_strcoll()");

  188519.   return 0;

  188520. }

  188521. 

  188522. /*

  188523. ** Implementation of the scalar function icu_load_collation().

  188524. **

  188525. ** This scalar function is used to add ICU collation based collation 

  188526. ** types to an SQLite database connection. It is intended to be called

  188527. ** as follows:

  188528. **

  188529. **     SELECT icu_load_collation(<locale>, <collation-name>);

  188530. **

  188531. ** Where <locale> is a string containing an ICU locale identifier (i.e.

  188532. ** "en_AU", "tr_TR" etc.) and <collation-name> is the name of the

  188533. ** collation sequence to create.

  188534. */

  188535. static void icuLoadCollation(

  188536.   sqlite3_context *p, 

  188537.   int nArg, 

  188538.   sqlite3_value **apArg

  188539. ){

  188540.   sqlite3 *db = (sqlite3 *)sqlite3_user_data(p);

  188541.   UErrorCode status = U_ZERO_ERROR;

  188542.   const char *zLocale;      /* Locale identifier - (eg. "jp_JP") */

  188543.   const char *zName;        /* SQL Collation sequence name (eg. "japanese") */

  188544.   UCollator *pUCollator;    /* ICU library collation object */

  188545.   int rc;                   /* Return code from sqlite3_create_collation_x() */

  188546. 

  188547.   assert(nArg==2);

  188548.   (void)nArg; /* Unused parameter */

  188549.   zLocale = (const char *)sqlite3_value_text(apArg[0]);

  188550.   zName = (const char *)sqlite3_value_text(apArg[1]);

  188551. 

  188552.   if( !zLocale || !zName ){

  188553.     return;

  188554.   }

  188555. 

  188556.   pUCollator = ucol_open(zLocale, &status);

  188557.   if( !U_SUCCESS(status) ){

  188558.     icuFunctionError(p, "ucol_open", status);

  188559.     return;

  188560.   }

  188561.   assert(p);

  188562. 

  188563.   rc = sqlite3_create_collation_v2(db, zName, SQLITE_UTF16, (void *)pUCollator, 

  188564.       icuCollationColl, icuCollationDel

  188565.   );

  188566.   if( rc!=SQLITE_OK ){

  188567.     ucol_close(pUCollator);

  188568.     sqlite3_result_error(p, "Error registering collation function", -1);

  188569.   }

  188570. }

  188571. 

  188572. /*

  188573. ** Register the ICU extension functions with database db.

  188574. */

  188575. SQLITE_PRIVATE int sqlite3IcuInit(sqlite3 *db){

  188576.   static const struct IcuScalar {

  188577.     const char *zName;                        /* Function name */

  188578.     unsigned char nArg;                       /* Number of arguments */

  188579.     unsigned short enc;                       /* Optimal text encoding */

  188580.     unsigned char iContext;                   /* sqlite3_user_data() context */

  188581.     void (*xFunc)(sqlite3_context*,int,sqlite3_value**);

  188582.   } scalars[] = {

  188583.     {"icu_load_collation",  2, SQLITE_UTF8,                1, icuLoadCollation},

  188584. #if !defined(SQLITE_CORE) || defined(SQLITE_ENABLE_ICU)

  188585.     {"regexp", 2, SQLITE_ANY|SQLITE_DETERMINISTIC,         0, icuRegexpFunc},

  188586.     {"lower",  1, SQLITE_UTF16|SQLITE_DETERMINISTIC,       0, icuCaseFunc16},

  188587.     {"lower",  2, SQLITE_UTF16|SQLITE_DETERMINISTIC,       0, icuCaseFunc16},

  188588.     {"upper",  1, SQLITE_UTF16|SQLITE_DETERMINISTIC,       1, icuCaseFunc16},

  188589.     {"upper",  2, SQLITE_UTF16|SQLITE_DETERMINISTIC,       1, icuCaseFunc16},

  188590.     {"lower",  1, SQLITE_UTF8|SQLITE_DETERMINISTIC,        0, icuCaseFunc16},

  188591.     {"lower",  2, SQLITE_UTF8|SQLITE_DETERMINISTIC,        0, icuCaseFunc16},

  188592.     {"upper",  1, SQLITE_UTF8|SQLITE_DETERMINISTIC,        1, icuCaseFunc16},

  188593.     {"upper",  2, SQLITE_UTF8|SQLITE_DETERMINISTIC,        1, icuCaseFunc16},

  188594.     {"like",   2, SQLITE_UTF8|SQLITE_DETERMINISTIC,        0, icuLikeFunc},

  188595.     {"like",   3, SQLITE_UTF8|SQLITE_DETERMINISTIC,        0, icuLikeFunc},

  188596. #endif /* !defined(SQLITE_CORE) || defined(SQLITE_ENABLE_ICU) */

  188597.   };

  188598.   int rc = SQLITE_OK;

  188599.   int i;

  188600.   

  188601.   for(i=0; rc==SQLITE_OK && i<(int)(sizeof(scalars)/sizeof(scalars[0])); i++){

  188602.     const struct IcuScalar *p = &scalars[i];

  188603.     rc = sqlite3_create_function(

  188604.         db, p->zName, p->nArg, p->enc, 

  188605.         p->iContext ? (void*)db : (void*)0,

  188606.         p->xFunc, 0, 0

  188607.     );

  188608.   }

  188609. 

  188610.   return rc;

  188611. }

  188612. 

  188613. #if !SQLITE_CORE

  188614. #ifdef _WIN32

  188615. __declspec(dllexport)

  188616. #endif

  188617. SQLITE_API int sqlite3_icu_init(

  188618.   sqlite3 *db, 

  188619.   char **pzErrMsg,

  188620.   const sqlite3_api_routines *pApi

  188621. ){

  188622.   SQLITE_EXTENSION_INIT2(pApi)

  188623.   return sqlite3IcuInit(db);

  188624. }

  188625. #endif

  188626. 

  188627. #endif

  188628. 

  188629. /************** End of icu.c *************************************************/

  188630. /************** Begin file fts3_icu.c ****************************************/

  188631. /*

  188632. ** 2007 June 22

  188633. **

  188634. ** The author disclaims copyright to this source code.  In place of

  188635. ** a legal notice, here is a blessing:

  188636. **

  188637. **    May you do good and not evil.

  188638. **    May you find forgiveness for yourself and forgive others.

  188639. **    May you share freely, never taking more than you give.

  188640. **

  188641. *************************************************************************

  188642. ** This file implements a tokenizer for fts3 based on the ICU library.

  188643. */

  188644. /* #include "fts3Int.h" */

  188645. #if !defined(SQLITE_CORE) || defined(SQLITE_ENABLE_FTS3)

  188646. #ifdef SQLITE_ENABLE_ICU

  188647. 

  188648. /* #include <assert.h> */

  188649. /* #include <string.h> */

  188650. /* #include "fts3_tokenizer.h" */

  188651. 

  188652. #include <unicode/ubrk.h>

  188653. /* #include <unicode/ucol.h> */

  188654. /* #include <unicode/ustring.h> */

  188655. #include <unicode/utf16.h>

  188656. 

  188657. typedef struct IcuTokenizer IcuTokenizer;

  188658. typedef struct IcuCursor IcuCursor;

  188659. 

  188660. struct IcuTokenizer {

  188661.   sqlite3_tokenizer base;

  188662.   char *zLocale;

  188663. };

  188664. 

  188665. struct IcuCursor {

  188666.   sqlite3_tokenizer_cursor base;

  188667. 

  188668.   UBreakIterator *pIter;      /* ICU break-iterator object */

  188669.   int nChar;                  /* Number of UChar elements in pInput */

  188670.   UChar *aChar;               /* Copy of input using utf-16 encoding */

  188671.   int *aOffset;               /* Offsets of each character in utf-8 input */

  188672. 

  188673.   int nBuffer;

  188674.   char *zBuffer;

  188675. 

  188676.   int iToken;

  188677. };

  188678. 

  188679. /*

  188680. ** Create a new tokenizer instance.

  188681. */

  188682. static int icuCreate(

  188683.   int argc,                            /* Number of entries in argv[] */

  188684.   const char * const *argv,            /* Tokenizer creation arguments */

  188685.   sqlite3_tokenizer **ppTokenizer      /* OUT: Created tokenizer */

  188686. ){

  188687.   IcuTokenizer *p;

  188688.   int n = 0;

  188689. 

  188690.   if( argc>0 ){

  188691.     n = strlen(argv[0])+1;

  188692.   }

  188693.   p = (IcuTokenizer *)sqlite3_malloc64(sizeof(IcuTokenizer)+n);

  188694.   if( !p ){

  188695.     return SQLITE_NOMEM;

  188696.   }

  188697.   memset(p, 0, sizeof(IcuTokenizer));

  188698. 

  188699.   if( n ){

  188700.     p->zLocale = (char *)&p[1];

  188701.     memcpy(p->zLocale, argv[0], n);

  188702.   }

  188703. 

  188704.   *ppTokenizer = (sqlite3_tokenizer *)p;

  188705. 

  188706.   return SQLITE_OK;

  188707. }

  188708. 

  188709. /*

  188710. ** Destroy a tokenizer

  188711. */

  188712. static int icuDestroy(sqlite3_tokenizer *pTokenizer){

  188713.   IcuTokenizer *p = (IcuTokenizer *)pTokenizer;

  188714.   sqlite3_free(p);

  188715.   return SQLITE_OK;

  188716. }

  188717. 

  188718. /*

  188719. ** Prepare to begin tokenizing a particular string.  The input

  188720. ** string to be tokenized is pInput[0..nBytes-1].  A cursor

  188721. ** used to incrementally tokenize this string is returned in 

  188722. ** *ppCursor.

  188723. */

  188724. static int icuOpen(

  188725.   sqlite3_tokenizer *pTokenizer,         /* The tokenizer */

  188726.   const char *zInput,                    /* Input string */

  188727.   int nInput,                            /* Length of zInput in bytes */

  188728.   sqlite3_tokenizer_cursor **ppCursor    /* OUT: Tokenization cursor */

  188729. ){

  188730.   IcuTokenizer *p = (IcuTokenizer *)pTokenizer;

  188731.   IcuCursor *pCsr;

  188732. 

  188733.   const int32_t opt = U_FOLD_CASE_DEFAULT;

  188734.   UErrorCode status = U_ZERO_ERROR;

  188735.   int nChar;

  188736. 

  188737.   UChar32 c;

  188738.   int iInput = 0;

  188739.   int iOut = 0;

  188740. 

  188741.   *ppCursor = 0;

  188742. 

  188743.   if( zInput==0 ){

  188744.     nInput = 0;

  188745.     zInput = "";

  188746.   }else if( nInput<0 ){

  188747.     nInput = strlen(zInput);

  188748.   }

  188749.   nChar = nInput+1;

  188750.   pCsr = (IcuCursor *)sqlite3_malloc64(

  188751.       sizeof(IcuCursor) +                /* IcuCursor */

  188752.       ((nChar+3)&~3) * sizeof(UChar) +   /* IcuCursor.aChar[] */

  188753.       (nChar+1) * sizeof(int)            /* IcuCursor.aOffset[] */

  188754.   );

  188755.   if( !pCsr ){

  188756.     return SQLITE_NOMEM;

  188757.   }

  188758.   memset(pCsr, 0, sizeof(IcuCursor));

  188759.   pCsr->aChar = (UChar *)&pCsr[1];

  188760.   pCsr->aOffset = (int *)&pCsr->aChar[(nChar+3)&~3];

  188761. 

  188762.   pCsr->aOffset[iOut] = iInput;

  188763.   U8_NEXT(zInput, iInput, nInput, c); 

  188764.   while( c>0 ){

  188765.     int isError = 0;

  188766.     c = u_foldCase(c, opt);

  188767.     U16_APPEND(pCsr->aChar, iOut, nChar, c, isError);

  188768.     if( isError ){

  188769.       sqlite3_free(pCsr);

  188770.       return SQLITE_ERROR;

  188771.     }

  188772.     pCsr->aOffset[iOut] = iInput;

  188773. 

  188774.     if( iInput<nInput ){

  188775.       U8_NEXT(zInput, iInput, nInput, c);

  188776.     }else{

  188777.       c = 0;

  188778.     }

  188779.   }

  188780. 

  188781.   pCsr->pIter = ubrk_open(UBRK_WORD, p->zLocale, pCsr->aChar, iOut, &status);

  188782.   if( !U_SUCCESS(status) ){

  188783.     sqlite3_free(pCsr);

  188784.     return SQLITE_ERROR;

  188785.   }

  188786.   pCsr->nChar = iOut;

  188787. 

  188788.   ubrk_first(pCsr->pIter);

  188789.   *ppCursor = (sqlite3_tokenizer_cursor *)pCsr;

  188790.   return SQLITE_OK;

  188791. }

  188792. 

  188793. /*

  188794. ** Close a tokenization cursor previously opened by a call to icuOpen().

  188795. */

  188796. static int icuClose(sqlite3_tokenizer_cursor *pCursor){

  188797.   IcuCursor *pCsr = (IcuCursor *)pCursor;

  188798.   ubrk_close(pCsr->pIter);

  188799.   sqlite3_free(pCsr->zBuffer);

  188800.   sqlite3_free(pCsr);

  188801.   return SQLITE_OK;

  188802. }

  188803. 

  188804. /*

  188805. ** Extract the next token from a tokenization cursor.

  188806. */

  188807. static int icuNext(

  188808.   sqlite3_tokenizer_cursor *pCursor,  /* Cursor returned by simpleOpen */

  188809.   const char **ppToken,               /* OUT: *ppToken is the token text */

  188810.   int *pnBytes,                       /* OUT: Number of bytes in token */

  188811.   int *piStartOffset,                 /* OUT: Starting offset of token */

  188812.   int *piEndOffset,                   /* OUT: Ending offset of token */

  188813.   int *piPosition                     /* OUT: Position integer of token */

  188814. ){

  188815.   IcuCursor *pCsr = (IcuCursor *)pCursor;

  188816. 

  188817.   int iStart = 0;

  188818.   int iEnd = 0;

  188819.   int nByte = 0;

  188820. 

  188821.   while( iStart==iEnd ){

  188822.     UChar32 c;

  188823. 

  188824.     iStart = ubrk_current(pCsr->pIter);

  188825.     iEnd = ubrk_next(pCsr->pIter);

  188826.     if( iEnd==UBRK_DONE ){

  188827.       return SQLITE_DONE;

  188828.     }

  188829. 

  188830.     while( iStart<iEnd ){

  188831.       int iWhite = iStart;

  188832.       U16_NEXT(pCsr->aChar, iWhite, pCsr->nChar, c);

  188833.       if( u_isspace(c) ){

  188834.         iStart = iWhite;

  188835.       }else{

  188836.         break;

  188837.       }

  188838.     }

  188839.     assert(iStart<=iEnd);

  188840.   }

  188841. 

  188842.   do {

  188843.     UErrorCode status = U_ZERO_ERROR;

  188844.     if( nByte ){

  188845.       char *zNew = sqlite3_realloc(pCsr->zBuffer, nByte);

  188846.       if( !zNew ){

  188847.         return SQLITE_NOMEM;

  188848.       }

  188849.       pCsr->zBuffer = zNew;

  188850.       pCsr->nBuffer = nByte;

  188851.     }

  188852. 

  188853.     u_strToUTF8(

  188854.         pCsr->zBuffer, pCsr->nBuffer, &nByte,    /* Output vars */

  188855.         &pCsr->aChar[iStart], iEnd-iStart,       /* Input vars */

  188856.         &status                                  /* Output success/failure */

  188857.     );

  188858.   } while( nByte>pCsr->nBuffer );

  188859. 

  188860.   *ppToken = pCsr->zBuffer;

  188861.   *pnBytes = nByte;

  188862.   *piStartOffset = pCsr->aOffset[iStart];

  188863.   *piEndOffset = pCsr->aOffset[iEnd];

  188864.   *piPosition = pCsr->iToken++;

  188865. 

  188866.   return SQLITE_OK;

  188867. }

  188868. 

  188869. /*

  188870. ** The set of routines that implement the simple tokenizer

  188871. */

  188872. static const sqlite3_tokenizer_module icuTokenizerModule = {

  188873.   0,                           /* iVersion    */

  188874.   icuCreate,                   /* xCreate     */

  188875.   icuDestroy,                  /* xCreate     */

  188876.   icuOpen,                     /* xOpen       */

  188877.   icuClose,                    /* xClose      */

  188878.   icuNext,                     /* xNext       */

  188879.   0,                           /* xLanguageid */

  188880. };

  188881. 

  188882. /*

  188883. ** Set *ppModule to point at the implementation of the ICU tokenizer.

  188884. */

  188885. SQLITE_PRIVATE void sqlite3Fts3IcuTokenizerModule(

  188886.   sqlite3_tokenizer_module const**ppModule

  188887. ){

  188888.   *ppModule = &icuTokenizerModule;

  188889. }

  188890. 

  188891. #endif /* defined(SQLITE_ENABLE_ICU) */

  188892. #endif /* !defined(SQLITE_CORE) || defined(SQLITE_ENABLE_FTS3) */

  188893. 

  188894. /************** End of fts3_icu.c ********************************************/

  188895. /************** Begin file sqlite3rbu.c **************************************/

  188896. /*

  188897. ** 2014 August 30

  188898. **

  188899. ** The author disclaims copyright to this source code.  In place of

  188900. ** a legal notice, here is a blessing:

  188901. **

  188902. **    May you do good and not evil.

  188903. **    May you find forgiveness for yourself and forgive others.

  188904. **    May you share freely, never taking more than you give.

  188905. **

  188906. *************************************************************************

  188907. **

  188908. **

  188909. ** OVERVIEW 

  188910. **

  188911. **  The RBU extension requires that the RBU update be packaged as an

  188912. **  SQLite database. The tables it expects to find are described in

  188913. **  sqlite3rbu.h.  Essentially, for each table xyz in the target database

  188914. **  that the user wishes to write to, a corresponding data_xyz table is

  188915. **  created in the RBU database and populated with one row for each row to

  188916. **  update, insert or delete from the target table.

  188917. ** 

  188918. **  The update proceeds in three stages:

  188919. ** 

  188920. **  1) The database is updated. The modified database pages are written

  188921. **     to a *-oal file. A *-oal file is just like a *-wal file, except

  188922. **     that it is named "<database>-oal" instead of "<database>-wal".

  188923. **     Because regular SQLite clients do not look for file named

  188924. **     "<database>-oal", they go on using the original database in

  188925. **     rollback mode while the *-oal file is being generated.

  188926. ** 

  188927. **     During this stage RBU does not update the database by writing

  188928. **     directly to the target tables. Instead it creates "imposter"

  188929. **     tables using the SQLITE_TESTCTRL_IMPOSTER interface that it uses

  188930. **     to update each b-tree individually. All updates required by each

  188931. **     b-tree are completed before moving on to the next, and all

  188932. **     updates are done in sorted key order.

  188933. ** 

  188934. **  2) The "<database>-oal" file is moved to the equivalent "<database>-wal"

  188935. **     location using a call to rename(2). Before doing this the RBU

  188936. **     module takes an EXCLUSIVE lock on the database file, ensuring

  188937. **     that there are no other active readers.

  188938. ** 

  188939. **     Once the EXCLUSIVE lock is released, any other database readers

  188940. **     detect the new *-wal file and read the database in wal mode. At

  188941. **     this point they see the new version of the database - including

  188942. **     the updates made as part of the RBU update.

  188943. ** 

  188944. **  3) The new *-wal file is checkpointed. This proceeds in the same way 

  188945. **     as a regular database checkpoint, except that a single frame is

  188946. **     checkpointed each time sqlite3rbu_step() is called. If the RBU

  188947. **     handle is closed before the entire *-wal file is checkpointed,

  188948. **     the checkpoint progress is saved in the RBU database and the

  188949. **     checkpoint can be resumed by another RBU client at some point in

  188950. **     the future.

  188951. **

  188952. ** POTENTIAL PROBLEMS

  188953. ** 

  188954. **  The rename() call might not be portable. And RBU is not currently

  188955. **  syncing the directory after renaming the file.

  188956. **

  188957. **  When state is saved, any commit to the *-oal file and the commit to

  188958. **  the RBU update database are not atomic. So if the power fails at the

  188959. **  wrong moment they might get out of sync. As the main database will be

  188960. **  committed before the RBU update database this will likely either just

  188961. **  pass unnoticed, or result in SQLITE_CONSTRAINT errors (due to UNIQUE

  188962. **  constraint violations).

  188963. **

  188964. **  If some client does modify the target database mid RBU update, or some

  188965. **  other error occurs, the RBU extension will keep throwing errors. It's

  188966. **  not really clear how to get out of this state. The system could just

  188967. **  by delete the RBU update database and *-oal file and have the device

  188968. **  download the update again and start over.

  188969. **

  188970. **  At present, for an UPDATE, both the new.* and old.* records are

  188971. **  collected in the rbu_xyz table. And for both UPDATEs and DELETEs all

  188972. **  fields are collected.  This means we're probably writing a lot more

  188973. **  data to disk when saving the state of an ongoing update to the RBU

  188974. **  update database than is strictly necessary.

  188975. ** 

  188976. */

  188977. 

  188978. /* #include <assert.h> */

  188979. /* #include <string.h> */

  188980. /* #include <stdio.h> */

  188981. 

  188982. /* #include "sqlite3.h" */

  188983. 

  188984. #if !defined(SQLITE_CORE) || defined(SQLITE_ENABLE_RBU)

  188985. /************** Include sqlite3rbu.h in the middle of sqlite3rbu.c ***********/

  188986. /************** Begin file sqlite3rbu.h **************************************/

  188987. /*

  188988. ** 2014 August 30

  188989. **

  188990. ** The author disclaims copyright to this source code.  In place of

  188991. ** a legal notice, here is a blessing:

  188992. **

  188993. **    May you do good and not evil.

  188994. **    May you find forgiveness for yourself and forgive others.

  188995. **    May you share freely, never taking more than you give.

  188996. **

  188997. *************************************************************************

  188998. **

  188999. ** This file contains the public interface for the RBU extension. 

  189000. */

  189001. 

  189002. /*

  189003. ** SUMMARY

  189004. **

  189005. ** Writing a transaction containing a large number of operations on 

  189006. ** b-tree indexes that are collectively larger than the available cache

  189007. ** memory can be very inefficient. 

  189008. **

  189009. ** The problem is that in order to update a b-tree, the leaf page (at least)

  189010. ** containing the entry being inserted or deleted must be modified. If the

  189011. ** working set of leaves is larger than the available cache memory, then a 

  189012. ** single leaf that is modified more than once as part of the transaction 

  189013. ** may be loaded from or written to the persistent media multiple times.

  189014. ** Additionally, because the index updates are likely to be applied in

  189015. ** random order, access to pages within the database is also likely to be in 

  189016. ** random order, which is itself quite inefficient.

  189017. **

  189018. ** One way to improve the situation is to sort the operations on each index

  189019. ** by index key before applying them to the b-tree. This leads to an IO

  189020. ** pattern that resembles a single linear scan through the index b-tree,

  189021. ** and all but guarantees each modified leaf page is loaded and stored 

  189022. ** exactly once. SQLite uses this trick to improve the performance of

  189023. ** CREATE INDEX commands. This extension allows it to be used to improve

  189024. ** the performance of large transactions on existing databases.

  189025. **

  189026. ** Additionally, this extension allows the work involved in writing the 

  189027. ** large transaction to be broken down into sub-transactions performed 

  189028. ** sequentially by separate processes. This is useful if the system cannot 

  189029. ** guarantee that a single update process will run for long enough to apply 

  189030. ** the entire update, for example because the update is being applied on a 

  189031. ** mobile device that is frequently rebooted. Even after the writer process 

  189032. ** has committed one or more sub-transactions, other database clients continue

  189033. ** to read from the original database snapshot. In other words, partially 

  189034. ** applied transactions are not visible to other clients. 

  189035. **

  189036. ** "RBU" stands for "Resumable Bulk Update". As in a large database update

  189037. ** transmitted via a wireless network to a mobile device. A transaction

  189038. ** applied using this extension is hence refered to as an "RBU update".

  189039. **

  189040. **

  189041. ** LIMITATIONS

  189042. **

  189043. ** An "RBU update" transaction is subject to the following limitations:

  189044. **

  189045. **   * The transaction must consist of INSERT, UPDATE and DELETE operations

  189046. **     only.

  189047. **

  189048. **   * INSERT statements may not use any default values.

  189049. **

  189050. **   * UPDATE and DELETE statements must identify their target rows by 

  189051. **     non-NULL PRIMARY KEY values. Rows with NULL values stored in PRIMARY

  189052. **     KEY fields may not be updated or deleted. If the table being written 

  189053. **     has no PRIMARY KEY, affected rows must be identified by rowid.

  189054. **

  189055. **   * UPDATE statements may not modify PRIMARY KEY columns.

  189056. **

  189057. **   * No triggers will be fired.

  189058. **

  189059. **   * No foreign key violations are detected or reported.

  189060. **

  189061. **   * CHECK constraints are not enforced.

  189062. **

  189063. **   * No constraint handling mode except for "OR ROLLBACK" is supported.

  189064. **

  189065. **

  189066. ** PREPARATION

  189067. **

  189068. ** An "RBU update" is stored as a separate SQLite database. A database

  189069. ** containing an RBU update is an "RBU database". For each table in the 

  189070. ** target database to be updated, the RBU database should contain a table

  189071. ** named "data_<target name>" containing the same set of columns as the

  189072. ** target table, and one more - "rbu_control". The data_% table should 

  189073. ** have no PRIMARY KEY or UNIQUE constraints, but each column should have

  189074. ** the same type as the corresponding column in the target database.

  189075. ** The "rbu_control" column should have no type at all. For example, if

  189076. ** the target database contains:

  189077. **

  189078. **   CREATE TABLE t1(a INTEGER PRIMARY KEY, b TEXT, c UNIQUE);

  189079. **

  189080. ** Then the RBU database should contain:

  189081. **

  189082. **   CREATE TABLE data_t1(a INTEGER, b TEXT, c, rbu_control);

  189083. **

  189084. ** The order of the columns in the data_% table does not matter.

  189085. **

  189086. ** Instead of a regular table, the RBU database may also contain virtual

  189087. ** tables or view named using the data_<target> naming scheme. 

  189088. **

  189089. ** Instead of the plain data_<target> naming scheme, RBU database tables 

  189090. ** may also be named data<integer>_<target>, where <integer> is any sequence

  189091. ** of zero or more numeric characters (0-9). This can be significant because

  189092. ** tables within the RBU database are always processed in order sorted by 

  189093. ** name. By judicious selection of the <integer> portion of the names

  189094. ** of the RBU tables the user can therefore control the order in which they

  189095. ** are processed. This can be useful, for example, to ensure that "external

  189096. ** content" FTS4 tables are updated before their underlying content tables.

  189097. **

  189098. ** If the target database table is a virtual table or a table that has no

  189099. ** PRIMARY KEY declaration, the data_% table must also contain a column 

  189100. ** named "rbu_rowid". This column is mapped to the tables implicit primary 

  189101. ** key column - "rowid". Virtual tables for which the "rowid" column does 

  189102. ** not function like a primary key value cannot be updated using RBU. For 

  189103. ** example, if the target db contains either of the following:

  189104. **

  189105. **   CREATE VIRTUAL TABLE x1 USING fts3(a, b);

  189106. **   CREATE TABLE x1(a, b)

  189107. **

  189108. ** then the RBU database should contain:

  189109. **

  189110. **   CREATE TABLE data_x1(a, b, rbu_rowid, rbu_control);

  189111. **

  189112. ** All non-hidden columns (i.e. all columns matched by "SELECT *") of the

  189113. ** target table must be present in the input table. For virtual tables,

  189114. ** hidden columns are optional - they are updated by RBU if present in

  189115. ** the input table, or not otherwise. For example, to write to an fts4

  189116. ** table with a hidden languageid column such as:

  189117. **

  189118. **   CREATE VIRTUAL TABLE ft1 USING fts4(a, b, languageid='langid');

  189119. **

  189120. ** Either of the following input table schemas may be used:

  189121. **

  189122. **   CREATE TABLE data_ft1(a, b, langid, rbu_rowid, rbu_control);

  189123. **   CREATE TABLE data_ft1(a, b, rbu_rowid, rbu_control);

  189124. **

  189125. ** For each row to INSERT into the target database as part of the RBU 

  189126. ** update, the corresponding data_% table should contain a single record

  189127. ** with the "rbu_control" column set to contain integer value 0. The

  189128. ** other columns should be set to the values that make up the new record 

  189129. ** to insert. 

  189130. **

  189131. ** If the target database table has an INTEGER PRIMARY KEY, it is not 

  189132. ** possible to insert a NULL value into the IPK column. Attempting to 

  189133. ** do so results in an SQLITE_MISMATCH error.

  189134. **

  189135. ** For each row to DELETE from the target database as part of the RBU 

  189136. ** update, the corresponding data_% table should contain a single record

  189137. ** with the "rbu_control" column set to contain integer value 1. The

  189138. ** real primary key values of the row to delete should be stored in the

  189139. ** corresponding columns of the data_% table. The values stored in the

  189140. ** other columns are not used.

  189141. **

  189142. ** For each row to UPDATE from the target database as part of the RBU 

  189143. ** update, the corresponding data_% table should contain a single record

  189144. ** with the "rbu_control" column set to contain a value of type text.

  189145. ** The real primary key values identifying the row to update should be 

  189146. ** stored in the corresponding columns of the data_% table row, as should

  189147. ** the new values of all columns being update. The text value in the 

  189148. ** "rbu_control" column must contain the same number of characters as

  189149. ** there are columns in the target database table, and must consist entirely

  189150. ** of 'x' and '.' characters (or in some special cases 'd' - see below). For 

  189151. ** each column that is being updated, the corresponding character is set to

  189152. ** 'x'. For those that remain as they are, the corresponding character of the

  189153. ** rbu_control value should be set to '.'. For example, given the tables 

  189154. ** above, the update statement:

  189155. **

  189156. **   UPDATE t1 SET c = 'usa' WHERE a = 4;

  189157. **

  189158. ** is represented by the data_t1 row created by:

  189159. **

  189160. **   INSERT INTO data_t1(a, b, c, rbu_control) VALUES(4, NULL, 'usa', '..x');

  189161. **

  189162. ** Instead of an 'x' character, characters of the rbu_control value specified

  189163. ** for UPDATEs may also be set to 'd'. In this case, instead of updating the

  189164. ** target table with the value stored in the corresponding data_% column, the

  189165. ** user-defined SQL function "rbu_delta()" is invoked and the result stored in

  189166. ** the target table column. rbu_delta() is invoked with two arguments - the

  189167. ** original value currently stored in the target table column and the 

  189168. ** value specified in the data_xxx table.

  189169. **

  189170. ** For example, this row:

  189171. **

  189172. **   INSERT INTO data_t1(a, b, c, rbu_control) VALUES(4, NULL, 'usa', '..d');

  189173. **

  189174. ** is similar to an UPDATE statement such as: 

  189175. **

  189176. **   UPDATE t1 SET c = rbu_delta(c, 'usa') WHERE a = 4;

  189177. **

  189178. ** Finally, if an 'f' character appears in place of a 'd' or 's' in an 

  189179. ** ota_control string, the contents of the data_xxx table column is assumed

  189180. ** to be a "fossil delta" - a patch to be applied to a blob value in the

  189181. ** format used by the fossil source-code management system. In this case

  189182. ** the existing value within the target database table must be of type BLOB. 

  189183. ** It is replaced by the result of applying the specified fossil delta to

  189184. ** itself.

  189185. **

  189186. ** If the target database table is a virtual table or a table with no PRIMARY

  189187. ** KEY, the rbu_control value should not include a character corresponding 

  189188. ** to the rbu_rowid value. For example, this:

  189189. **

  189190. **   INSERT INTO data_ft1(a, b, rbu_rowid, rbu_control) 

  189191. **       VALUES(NULL, 'usa', 12, '.x');

  189192. **

  189193. ** causes a result similar to:

  189194. **

  189195. **   UPDATE ft1 SET b = 'usa' WHERE rowid = 12;

  189196. **

  189197. ** The data_xxx tables themselves should have no PRIMARY KEY declarations.

  189198. ** However, RBU is more efficient if reading the rows in from each data_xxx

  189199. ** table in "rowid" order is roughly the same as reading them sorted by

  189200. ** the PRIMARY KEY of the corresponding target database table. In other 

  189201. ** words, rows should be sorted using the destination table PRIMARY KEY 

  189202. ** fields before they are inserted into the data_xxx tables.

  189203. **

  189204. ** USAGE

  189205. **

  189206. ** The API declared below allows an application to apply an RBU update 

  189207. ** stored on disk to an existing target database. Essentially, the 

  189208. ** application:

  189209. **

  189210. **     1) Opens an RBU handle using the sqlite3rbu_open() function.

  189211. **

  189212. **     2) Registers any required virtual table modules with the database

  189213. **        handle returned by sqlite3rbu_db(). Also, if required, register

  189214. **        the rbu_delta() implementation.

  189215. **

  189216. **     3) Calls the sqlite3rbu_step() function one or more times on

  189217. **        the new handle. Each call to sqlite3rbu_step() performs a single

  189218. **        b-tree operation, so thousands of calls may be required to apply 

  189219. **        a complete update.

  189220. **

  189221. **     4) Calls sqlite3rbu_close() to close the RBU update handle. If

  189222. **        sqlite3rbu_step() has been called enough times to completely

  189223. **        apply the update to the target database, then the RBU database

  189224. **        is marked as fully applied. Otherwise, the state of the RBU 

  189225. **        update application is saved in the RBU database for later 

  189226. **        resumption.

  189227. **

  189228. ** See comments below for more detail on APIs.

  189229. **

  189230. ** If an update is only partially applied to the target database by the

  189231. ** time sqlite3rbu_close() is called, various state information is saved 

  189232. ** within the RBU database. This allows subsequent processes to automatically

  189233. ** resume the RBU update from where it left off.

  189234. **

  189235. ** To remove all RBU extension state information, returning an RBU database 

  189236. ** to its original contents, it is sufficient to drop all tables that begin

  189237. ** with the prefix "rbu_"

  189238. **

  189239. ** DATABASE LOCKING

  189240. **

  189241. ** An RBU update may not be applied to a database in WAL mode. Attempting

  189242. ** to do so is an error (SQLITE_ERROR).

  189243. **

  189244. ** While an RBU handle is open, a SHARED lock may be held on the target

  189245. ** database file. This means it is possible for other clients to read the

  189246. ** database, but not to write it.

  189247. **

  189248. ** If an RBU update is started and then suspended before it is completed,

  189249. ** then an external client writes to the database, then attempting to resume

  189250. ** the suspended RBU update is also an error (SQLITE_BUSY).

  189251. */

  189252. 

  189253. #ifndef _SQLITE3RBU_H

  189254. #define _SQLITE3RBU_H

  189255. 

  189256. /* #include "sqlite3.h"              ** Required for error code definitions ** */

  189257. 

  189258. #if 0

  189259. extern "C" {

  189260. #endif

  189261. 

  189262. typedef struct sqlite3rbu sqlite3rbu;

  189263. 

  189264. /*

  189265. ** Open an RBU handle.

  189266. **

  189267. ** Argument zTarget is the path to the target database. Argument zRbu is

  189268. ** the path to the RBU database. Each call to this function must be matched

  189269. ** by a call to sqlite3rbu_close(). When opening the databases, RBU passes

  189270. ** the SQLITE_CONFIG_URI flag to sqlite3_open_v2(). So if either zTarget

  189271. ** or zRbu begin with "file:", it will be interpreted as an SQLite 

  189272. ** database URI, not a regular file name.

  189273. **

  189274. ** If the zState argument is passed a NULL value, the RBU extension stores 

  189275. ** the current state of the update (how many rows have been updated, which 

  189276. ** indexes are yet to be updated etc.) within the RBU database itself. This

  189277. ** can be convenient, as it means that the RBU application does not need to

  189278. ** organize removing a separate state file after the update is concluded. 

  189279. ** Or, if zState is non-NULL, it must be a path to a database file in which 

  189280. ** the RBU extension can store the state of the update.

  189281. **

  189282. ** When resuming an RBU update, the zState argument must be passed the same

  189283. ** value as when the RBU update was started.

  189284. **

  189285. ** Once the RBU update is finished, the RBU extension does not 

  189286. ** automatically remove any zState database file, even if it created it.

  189287. **

  189288. ** By default, RBU uses the default VFS to access the files on disk. To

  189289. ** use a VFS other than the default, an SQLite "file:" URI containing a

  189290. ** "vfs=..." option may be passed as the zTarget option.

  189291. **

  189292. ** IMPORTANT NOTE FOR ZIPVFS USERS: The RBU extension works with all of

  189293. ** SQLite's built-in VFSs, including the multiplexor VFS. However it does

  189294. ** not work out of the box with zipvfs. Refer to the comment describing

  189295. ** the zipvfs_create_vfs() API below for details on using RBU with zipvfs.

  189296. */

  189297. SQLITE_API sqlite3rbu *sqlite3rbu_open(

  189298.   const char *zTarget, 

  189299.   const char *zRbu,

  189300.   const char *zState

  189301. );

  189302. 

  189303. /*

  189304. ** Open an RBU handle to perform an RBU vacuum on database file zTarget.

  189305. ** An RBU vacuum is similar to SQLite's built-in VACUUM command, except

  189306. ** that it can be suspended and resumed like an RBU update.

  189307. **

  189308. ** The second argument to this function identifies a database in which 

  189309. ** to store the state of the RBU vacuum operation if it is suspended. The 

  189310. ** first time sqlite3rbu_vacuum() is called, to start an RBU vacuum

  189311. ** operation, the state database should either not exist or be empty

  189312. ** (contain no tables). If an RBU vacuum is suspended by calling 

  189313. ** sqlite3rbu_close() on the RBU handle before sqlite3rbu_step() has

  189314. ** returned SQLITE_DONE, the vacuum state is stored in the state database. 

  189315. ** The vacuum can be resumed by calling this function to open a new RBU

  189316. ** handle specifying the same target and state databases.

  189317. **

  189318. ** If the second argument passed to this function is NULL, then the

  189319. ** name of the state database is "<database>-vacuum", where <database>

  189320. ** is the name of the target database file. In this case, on UNIX, if the

  189321. ** state database is not already present in the file-system, it is created

  189322. ** with the same permissions as the target db is made. 

  189323. **

  189324. ** With an RBU vacuum, it is an SQLITE_MISUSE error if the name of the 

  189325. ** state database ends with "-vactmp". This name is reserved for internal 

  189326. ** use.

  189327. **

  189328. ** This function does not delete the state database after an RBU vacuum

  189329. ** is completed, even if it created it. However, if the call to

  189330. ** sqlite3rbu_close() returns any value other than SQLITE_OK, the contents

  189331. ** of the state tables within the state database are zeroed. This way,

  189332. ** the next call to sqlite3rbu_vacuum() opens a handle that starts a 

  189333. ** new RBU vacuum operation.

  189334. **

  189335. ** As with sqlite3rbu_open(), Zipvfs users should rever to the comment

  189336. ** describing the sqlite3rbu_create_vfs() API function below for 

  189337. ** a description of the complications associated with using RBU with 

  189338. ** zipvfs databases.

  189339. */

  189340. SQLITE_API sqlite3rbu *sqlite3rbu_vacuum(

  189341.   const char *zTarget, 

  189342.   const char *zState

  189343. );

  189344. 

  189345. /*

  189346. ** Configure a limit for the amount of temp space that may be used by

  189347. ** the RBU handle passed as the first argument. The new limit is specified

  189348. ** in bytes by the second parameter. If it is positive, the limit is updated.

  189349. ** If the second parameter to this function is passed zero, then the limit

  189350. ** is removed entirely. If the second parameter is negative, the limit is

  189351. ** not modified (this is useful for querying the current limit).

  189352. **

  189353. ** In all cases the returned value is the current limit in bytes (zero 

  189354. ** indicates unlimited).

  189355. **

  189356. ** If the temp space limit is exceeded during operation, an SQLITE_FULL

  189357. ** error is returned.

  189358. */

  189359. SQLITE_API sqlite3_int64 sqlite3rbu_temp_size_limit(sqlite3rbu*, sqlite3_int64);

  189360. 

  189361. /*

  189362. ** Return the current amount of temp file space, in bytes, currently used by 

  189363. ** the RBU handle passed as the only argument.

  189364. */

  189365. SQLITE_API sqlite3_int64 sqlite3rbu_temp_size(sqlite3rbu*);

  189366. 

  189367. /*

  189368. ** Internally, each RBU connection uses a separate SQLite database 

  189369. ** connection to access the target and rbu update databases. This

  189370. ** API allows the application direct access to these database handles.

  189371. **

  189372. ** The first argument passed to this function must be a valid, open, RBU

  189373. ** handle. The second argument should be passed zero to access the target

  189374. ** database handle, or non-zero to access the rbu update database handle.

  189375. ** Accessing the underlying database handles may be useful in the

  189376. ** following scenarios:

  189377. **

  189378. **   * If any target tables are virtual tables, it may be necessary to

  189379. **     call sqlite3_create_module() on the target database handle to 

  189380. **     register the required virtual table implementations.

  189381. **

  189382. **   * If the data_xxx tables in the RBU source database are virtual 

  189383. **     tables, the application may need to call sqlite3_create_module() on

  189384. **     the rbu update db handle to any required virtual table

  189385. **     implementations.

  189386. **

  189387. **   * If the application uses the "rbu_delta()" feature described above,

  189388. **     it must use sqlite3_create_function() or similar to register the

  189389. **     rbu_delta() implementation with the target database handle.

  189390. **

  189391. ** If an error has occurred, either while opening or stepping the RBU object,

  189392. ** this function may return NULL. The error code and message may be collected

  189393. ** when sqlite3rbu_close() is called.

  189394. **

  189395. ** Database handles returned by this function remain valid until the next

  189396. ** call to any sqlite3rbu_xxx() function other than sqlite3rbu_db().

  189397. */

  189398. SQLITE_API sqlite3 *sqlite3rbu_db(sqlite3rbu*, int bRbu);

  189399. 

  189400. /*

  189401. ** Do some work towards applying the RBU update to the target db. 

  189402. **

  189403. ** Return SQLITE_DONE if the update has been completely applied, or 

  189404. ** SQLITE_OK if no error occurs but there remains work to do to apply

  189405. ** the RBU update. If an error does occur, some other error code is 

  189406. ** returned. 

  189407. **

  189408. ** Once a call to sqlite3rbu_step() has returned a value other than

  189409. ** SQLITE_OK, all subsequent calls on the same RBU handle are no-ops

  189410. ** that immediately return the same value.

  189411. */

  189412. SQLITE_API int sqlite3rbu_step(sqlite3rbu *pRbu);

  189413. 

  189414. /*

  189415. ** Force RBU to save its state to disk.

  189416. **

  189417. ** If a power failure or application crash occurs during an update, following

  189418. ** system recovery RBU may resume the update from the point at which the state

  189419. ** was last saved. In other words, from the most recent successful call to 

  189420. ** sqlite3rbu_close() or this function.

  189421. **

  189422. ** SQLITE_OK is returned if successful, or an SQLite error code otherwise.

  189423. */

  189424. SQLITE_API int sqlite3rbu_savestate(sqlite3rbu *pRbu);

  189425. 

  189426. /*

  189427. ** Close an RBU handle. 

  189428. **

  189429. ** If the RBU update has been completely applied, mark the RBU database

  189430. ** as fully applied. Otherwise, assuming no error has occurred, save the

  189431. ** current state of the RBU update appliation to the RBU database.

  189432. **

  189433. ** If an error has already occurred as part of an sqlite3rbu_step()

  189434. ** or sqlite3rbu_open() call, or if one occurs within this function, an

  189435. ** SQLite error code is returned. Additionally, if pzErrmsg is not NULL,

  189436. ** *pzErrmsg may be set to point to a buffer containing a utf-8 formatted

  189437. ** English language error message. It is the responsibility of the caller to

  189438. ** eventually free any such buffer using sqlite3_free().

  189439. **

  189440. ** Otherwise, if no error occurs, this function returns SQLITE_OK if the

  189441. ** update has been partially applied, or SQLITE_DONE if it has been 

  189442. ** completely applied.

  189443. */

  189444. SQLITE_API int sqlite3rbu_close(sqlite3rbu *pRbu, char **pzErrmsg);

  189445. 

  189446. /*

  189447. ** Return the total number of key-value operations (inserts, deletes or 

  189448. ** updates) that have been performed on the target database since the

  189449. ** current RBU update was started.

  189450. */

  189451. SQLITE_API sqlite3_int64 sqlite3rbu_progress(sqlite3rbu *pRbu);

  189452. 

  189453. /*

  189454. ** Obtain permyriadage (permyriadage is to 10000 as percentage is to 100) 

  189455. ** progress indications for the two stages of an RBU update. This API may

  189456. ** be useful for driving GUI progress indicators and similar.

  189457. **

  189458. ** An RBU update is divided into two stages:

  189459. **

  189460. **   * Stage 1, in which changes are accumulated in an oal/wal file, and

  189461. **   * Stage 2, in which the contents of the wal file are copied into the

  189462. **     main database.

  189463. **

  189464. ** The update is visible to non-RBU clients during stage 2. During stage 1

  189465. ** non-RBU reader clients may see the original database.

  189466. **

  189467. ** If this API is called during stage 2 of the update, output variable 

  189468. ** (*pnOne) is set to 10000 to indicate that stage 1 has finished and (*pnTwo)

  189469. ** to a value between 0 and 10000 to indicate the permyriadage progress of

  189470. ** stage 2. A value of 5000 indicates that stage 2 is half finished, 

  189471. ** 9000 indicates that it is 90% finished, and so on.

  189472. **

  189473. ** If this API is called during stage 1 of the update, output variable 

  189474. ** (*pnTwo) is set to 0 to indicate that stage 2 has not yet started. The

  189475. ** value to which (*pnOne) is set depends on whether or not the RBU 

  189476. ** database contains an "rbu_count" table. The rbu_count table, if it 

  189477. ** exists, must contain the same columns as the following:

  189478. **

  189479. **   CREATE TABLE rbu_count(tbl TEXT PRIMARY KEY, cnt INTEGER) WITHOUT ROWID;

  189480. **

  189481. ** There must be one row in the table for each source (data_xxx) table within

  189482. ** the RBU database. The 'tbl' column should contain the name of the source

  189483. ** table. The 'cnt' column should contain the number of rows within the

  189484. ** source table.

  189485. **

  189486. ** If the rbu_count table is present and populated correctly and this

  189487. ** API is called during stage 1, the *pnOne output variable is set to the

  189488. ** permyriadage progress of the same stage. If the rbu_count table does

  189489. ** not exist, then (*pnOne) is set to -1 during stage 1. If the rbu_count

  189490. ** table exists but is not correctly populated, the value of the *pnOne

  189491. ** output variable during stage 1 is undefined.

  189492. */

  189493. SQLITE_API void sqlite3rbu_bp_progress(sqlite3rbu *pRbu, int *pnOne, int*pnTwo);

  189494. 

  189495. /*

  189496. ** Obtain an indication as to the current stage of an RBU update or vacuum.

  189497. ** This function always returns one of the SQLITE_RBU_STATE_XXX constants

  189498. ** defined in this file. Return values should be interpreted as follows:

  189499. **

  189500. ** SQLITE_RBU_STATE_OAL:

  189501. **   RBU is currently building a *-oal file. The next call to sqlite3rbu_step()

  189502. **   may either add further data to the *-oal file, or compute data that will

  189503. **   be added by a subsequent call.

  189504. **

  189505. ** SQLITE_RBU_STATE_MOVE:

  189506. **   RBU has finished building the *-oal file. The next call to sqlite3rbu_step()

  189507. **   will move the *-oal file to the equivalent *-wal path. If the current

  189508. **   operation is an RBU update, then the updated version of the database

  189509. **   file will become visible to ordinary SQLite clients following the next

  189510. **   call to sqlite3rbu_step().

  189511. **

  189512. ** SQLITE_RBU_STATE_CHECKPOINT:

  189513. **   RBU is currently performing an incremental checkpoint. The next call to

  189514. **   sqlite3rbu_step() will copy a page of data from the *-wal file into

  189515. **   the target database file.

  189516. **

  189517. ** SQLITE_RBU_STATE_DONE:

  189518. **   The RBU operation has finished. Any subsequent calls to sqlite3rbu_step()

  189519. **   will immediately return SQLITE_DONE.

  189520. **

  189521. ** SQLITE_RBU_STATE_ERROR:

  189522. **   An error has occurred. Any subsequent calls to sqlite3rbu_step() will

  189523. **   immediately return the SQLite error code associated with the error.

  189524. */

  189525. #define SQLITE_RBU_STATE_OAL        1

  189526. #define SQLITE_RBU_STATE_MOVE       2

  189527. #define SQLITE_RBU_STATE_CHECKPOINT 3

  189528. #define SQLITE_RBU_STATE_DONE       4

  189529. #define SQLITE_RBU_STATE_ERROR      5

  189530. 

  189531. SQLITE_API int sqlite3rbu_state(sqlite3rbu *pRbu);

  189532. 

  189533. /*

  189534. ** Create an RBU VFS named zName that accesses the underlying file-system

  189535. ** via existing VFS zParent. Or, if the zParent parameter is passed NULL, 

  189536. ** then the new RBU VFS uses the default system VFS to access the file-system.

  189537. ** The new object is registered as a non-default VFS with SQLite before 

  189538. ** returning.

  189539. **

  189540. ** Part of the RBU implementation uses a custom VFS object. Usually, this

  189541. ** object is created and deleted automatically by RBU. 

  189542. **

  189543. ** The exception is for applications that also use zipvfs. In this case,

  189544. ** the custom VFS must be explicitly created by the user before the RBU

  189545. ** handle is opened. The RBU VFS should be installed so that the zipvfs

  189546. ** VFS uses the RBU VFS, which in turn uses any other VFS layers in use 

  189547. ** (for example multiplexor) to access the file-system. For example,

  189548. ** to assemble an RBU enabled VFS stack that uses both zipvfs and 

  189549. ** multiplexor (error checking omitted):

  189550. **

  189551. **     // Create a VFS named "multiplex" (not the default).

  189552. **     sqlite3_multiplex_initialize(0, 0);

  189553. **

  189554. **     // Create an rbu VFS named "rbu" that uses multiplexor. If the

  189555. **     // second argument were replaced with NULL, the "rbu" VFS would

  189556. **     // access the file-system via the system default VFS, bypassing the

  189557. **     // multiplexor.

  189558. **     sqlite3rbu_create_vfs("rbu", "multiplex");

  189559. **

  189560. **     // Create a zipvfs VFS named "zipvfs" that uses rbu.

  189561. **     zipvfs_create_vfs_v3("zipvfs", "rbu", 0, xCompressorAlgorithmDetector);

  189562. **

  189563. **     // Make zipvfs the default VFS.

  189564. **     sqlite3_vfs_register(sqlite3_vfs_find("zipvfs"), 1);

  189565. **

  189566. ** Because the default VFS created above includes a RBU functionality, it

  189567. ** may be used by RBU clients. Attempting to use RBU with a zipvfs VFS stack

  189568. ** that does not include the RBU layer results in an error.

  189569. **

  189570. ** The overhead of adding the "rbu" VFS to the system is negligible for 

  189571. ** non-RBU users. There is no harm in an application accessing the 

  189572. ** file-system via "rbu" all the time, even if it only uses RBU functionality 

  189573. ** occasionally.

  189574. */

  189575. SQLITE_API int sqlite3rbu_create_vfs(const char *zName, const char *zParent);

  189576. 

  189577. /*

  189578. ** Deregister and destroy an RBU vfs created by an earlier call to

  189579. ** sqlite3rbu_create_vfs().

  189580. **

  189581. ** VFS objects are not reference counted. If a VFS object is destroyed

  189582. ** before all database handles that use it have been closed, the results

  189583. ** are undefined.

  189584. */

  189585. SQLITE_API void sqlite3rbu_destroy_vfs(const char *zName);

  189586. 

  189587. #if 0

  189588. }  /* end of the 'extern "C"' block */

  189589. #endif

  189590. 

  189591. #endif /* _SQLITE3RBU_H */

  189592. 

  189593. /************** End of sqlite3rbu.h ******************************************/

  189594. /************** Continuing where we left off in sqlite3rbu.c *****************/

  189595. 

  189596. #if defined(_WIN32_WCE)

  189597. /* #include "windows.h" */

  189598. #endif

  189599. 

  189600. /* Maximum number of prepared UPDATE statements held by this module */

  189601. #define SQLITE_RBU_UPDATE_CACHESIZE 16

  189602. 

  189603. /* Delta checksums disabled by default.  Compile with -DRBU_ENABLE_DELTA_CKSUM

  189604. ** to enable checksum verification.

  189605. */

  189606. #ifndef RBU_ENABLE_DELTA_CKSUM

  189607. # define RBU_ENABLE_DELTA_CKSUM 0

  189608. #endif

  189609. 

  189610. /*

  189611. ** Swap two objects of type TYPE.

  189612. */

  189613. #if !defined(SQLITE_AMALGAMATION)

  189614. # define SWAP(TYPE,A,B) {TYPE t=A; A=B; B=t;}

  189615. #endif

  189616. 

  189617. /*

  189618. ** The rbu_state table is used to save the state of a partially applied

  189619. ** update so that it can be resumed later. The table consists of integer

  189620. ** keys mapped to values as follows:

  189621. **

  189622. ** RBU_STATE_STAGE:

  189623. **   May be set to integer values 1, 2, 4 or 5. As follows:

  189624. **       1: the *-rbu file is currently under construction.

  189625. **       2: the *-rbu file has been constructed, but not yet moved 

  189626. **          to the *-wal path.

  189627. **       4: the checkpoint is underway.

  189628. **       5: the rbu update has been checkpointed.

  189629. **

  189630. ** RBU_STATE_TBL:

  189631. **   Only valid if STAGE==1. The target database name of the table 

  189632. **   currently being written.

  189633. **

  189634. ** RBU_STATE_IDX:

  189635. **   Only valid if STAGE==1. The target database name of the index 

  189636. **   currently being written, or NULL if the main table is currently being

  189637. **   updated.

  189638. **

  189639. ** RBU_STATE_ROW:

  189640. **   Only valid if STAGE==1. Number of rows already processed for the current

  189641. **   table/index.

  189642. **

  189643. ** RBU_STATE_PROGRESS:

  189644. **   Trbul number of sqlite3rbu_step() calls made so far as part of this

  189645. **   rbu update.

  189646. **

  189647. ** RBU_STATE_CKPT:

  189648. **   Valid if STAGE==4. The 64-bit checksum associated with the wal-index

  189649. **   header created by recovering the *-wal file. This is used to detect

  189650. **   cases when another client appends frames to the *-wal file in the

  189651. **   middle of an incremental checkpoint (an incremental checkpoint cannot

  189652. **   be continued if this happens).

  189653. **

  189654. ** RBU_STATE_COOKIE:

  189655. **   Valid if STAGE==1. The current change-counter cookie value in the 

  189656. **   target db file.

  189657. **

  189658. ** RBU_STATE_OALSZ:

  189659. **   Valid if STAGE==1. The size in bytes of the *-oal file.

  189660. **

  189661. ** RBU_STATE_DATATBL:

  189662. **   Only valid if STAGE==1. The RBU database name of the table 

  189663. **   currently being read.

  189664. */

  189665. #define RBU_STATE_STAGE        1

  189666. #define RBU_STATE_TBL          2

  189667. #define RBU_STATE_IDX          3

  189668. #define RBU_STATE_ROW          4

  189669. #define RBU_STATE_PROGRESS     5

  189670. #define RBU_STATE_CKPT         6

  189671. #define RBU_STATE_COOKIE       7

  189672. #define RBU_STATE_OALSZ        8

  189673. #define RBU_STATE_PHASEONESTEP 9

  189674. #define RBU_STATE_DATATBL     10

  189675. 

  189676. #define RBU_STAGE_OAL         1

  189677. #define RBU_STAGE_MOVE        2

  189678. #define RBU_STAGE_CAPTURE     3

  189679. #define RBU_STAGE_CKPT        4

  189680. #define RBU_STAGE_DONE        5

  189681. 

  189682. 

  189683. #define RBU_CREATE_STATE \

  189684.   "CREATE TABLE IF NOT EXISTS %s.rbu_state(k INTEGER PRIMARY KEY, v)"

  189685. 

  189686. typedef struct RbuFrame RbuFrame;

  189687. typedef struct RbuObjIter RbuObjIter;

  189688. typedef struct RbuState RbuState;

  189689. typedef struct rbu_vfs rbu_vfs;

  189690. typedef struct rbu_file rbu_file;

  189691. typedef struct RbuUpdateStmt RbuUpdateStmt;

  189692. 

  189693. #if !defined(SQLITE_AMALGAMATION)

  189694. typedef unsigned int u32;

  189695. typedef unsigned short u16;

  189696. typedef unsigned char u8;

  189697. typedef sqlite3_int64 i64;

  189698. #endif

  189699. 

  189700. /*

  189701. ** These values must match the values defined in wal.c for the equivalent

  189702. ** locks. These are not magic numbers as they are part of the SQLite file

  189703. ** format.

  189704. */

  189705. #define WAL_LOCK_WRITE  0

  189706. #define WAL_LOCK_CKPT   1

  189707. #define WAL_LOCK_READ0  3

  189708. 

  189709. #define SQLITE_FCNTL_RBUCNT    5149216

  189710. 

  189711. /*

  189712. ** A structure to store values read from the rbu_state table in memory.

  189713. */

  189714. struct RbuState {

  189715.   int eStage;

  189716.   char *zTbl;

  189717.   char *zDataTbl;

  189718.   char *zIdx;

  189719.   i64 iWalCksum;

  189720.   int nRow;

  189721.   i64 nProgress;

  189722.   u32 iCookie;

  189723.   i64 iOalSz;

  189724.   i64 nPhaseOneStep;

  189725. };

  189726. 

  189727. struct RbuUpdateStmt {

  189728.   char *zMask;                    /* Copy of update mask used with pUpdate */

  189729.   sqlite3_stmt *pUpdate;          /* Last update statement (or NULL) */

  189730.   RbuUpdateStmt *pNext;

  189731. };

  189732. 

  189733. /*

  189734. ** An iterator of this type is used to iterate through all objects in

  189735. ** the target database that require updating. For each such table, the

  189736. ** iterator visits, in order:

  189737. **

  189738. **     * the table itself, 

  189739. **     * each index of the table (zero or more points to visit), and

  189740. **     * a special "cleanup table" state.

  189741. **

  189742. ** abIndexed:

  189743. **   If the table has no indexes on it, abIndexed is set to NULL. Otherwise,

  189744. **   it points to an array of flags nTblCol elements in size. The flag is

  189745. **   set for each column that is either a part of the PK or a part of an

  189746. **   index. Or clear otherwise.

  189747. **

  189748. **   If there are one or more partial indexes on the table, all fields of

  189749. **   this array set set to 1. This is because in that case, the module has

  189750. **   no way to tell which fields will be required to add and remove entries

  189751. **   from the partial indexes.

  189752. **   

  189753. */

  189754. struct RbuObjIter {

  189755.   sqlite3_stmt *pTblIter;         /* Iterate through tables */

  189756.   sqlite3_stmt *pIdxIter;         /* Index iterator */

  189757.   int nTblCol;                    /* Size of azTblCol[] array */

  189758.   char **azTblCol;                /* Array of unquoted target column names */

  189759.   char **azTblType;               /* Array of target column types */

  189760.   int *aiSrcOrder;                /* src table col -> target table col */

  189761.   u8 *abTblPk;                    /* Array of flags, set on target PK columns */

  189762.   u8 *abNotNull;                  /* Array of flags, set on NOT NULL columns */

  189763.   u8 *abIndexed;                  /* Array of flags, set on indexed & PK cols */

  189764.   int eType;                      /* Table type - an RBU_PK_XXX value */

  189765. 

  189766.   /* Output variables. zTbl==0 implies EOF. */

  189767.   int bCleanup;                   /* True in "cleanup" state */

  189768.   const char *zTbl;               /* Name of target db table */

  189769.   const char *zDataTbl;           /* Name of rbu db table (or null) */

  189770.   const char *zIdx;               /* Name of target db index (or null) */

  189771.   int iTnum;                      /* Root page of current object */

  189772.   int iPkTnum;                    /* If eType==EXTERNAL, root of PK index */

  189773.   int bUnique;                    /* Current index is unique */

  189774.   int nIndex;                     /* Number of aux. indexes on table zTbl */

  189775. 

  189776.   /* Statements created by rbuObjIterPrepareAll() */

  189777.   int nCol;                       /* Number of columns in current object */

  189778.   sqlite3_stmt *pSelect;          /* Source data */

  189779.   sqlite3_stmt *pInsert;          /* Statement for INSERT operations */

  189780.   sqlite3_stmt *pDelete;          /* Statement for DELETE ops */

  189781.   sqlite3_stmt *pTmpInsert;       /* Insert into rbu_tmp_$zDataTbl */

  189782. 

  189783.   /* Last UPDATE used (for PK b-tree updates only), or NULL. */

  189784.   RbuUpdateStmt *pRbuUpdate;

  189785. };

  189786. 

  189787. /*

  189788. ** Values for RbuObjIter.eType

  189789. **

  189790. **     0: Table does not exist (error)

  189791. **     1: Table has an implicit rowid.

  189792. **     2: Table has an explicit IPK column.

  189793. **     3: Table has an external PK index.

  189794. **     4: Table is WITHOUT ROWID.

  189795. **     5: Table is a virtual table.

  189796. */

  189797. #define RBU_PK_NOTABLE        0

  189798. #define RBU_PK_NONE           1

  189799. #define RBU_PK_IPK            2

  189800. #define RBU_PK_EXTERNAL       3

  189801. #define RBU_PK_WITHOUT_ROWID  4

  189802. #define RBU_PK_VTAB           5

  189803. 

  189804. 

  189805. /*

  189806. ** Within the RBU_STAGE_OAL stage, each call to sqlite3rbu_step() performs

  189807. ** one of the following operations.

  189808. */

  189809. #define RBU_INSERT     1          /* Insert on a main table b-tree */

  189810. #define RBU_DELETE     2          /* Delete a row from a main table b-tree */

  189811. #define RBU_REPLACE    3          /* Delete and then insert a row */

  189812. #define RBU_IDX_DELETE 4          /* Delete a row from an aux. index b-tree */

  189813. #define RBU_IDX_INSERT 5          /* Insert on an aux. index b-tree */

  189814. 

  189815. #define RBU_UPDATE     6          /* Update a row in a main table b-tree */

  189816. 

  189817. /*

  189818. ** A single step of an incremental checkpoint - frame iWalFrame of the wal

  189819. ** file should be copied to page iDbPage of the database file.

  189820. */

  189821. struct RbuFrame {

  189822.   u32 iDbPage;

  189823.   u32 iWalFrame;

  189824. };

  189825. 

  189826. /*

  189827. ** RBU handle.

  189828. **

  189829. ** nPhaseOneStep:

  189830. **   If the RBU database contains an rbu_count table, this value is set to

  189831. **   a running estimate of the number of b-tree operations required to 

  189832. **   finish populating the *-oal file. This allows the sqlite3_bp_progress()

  189833. **   API to calculate the permyriadage progress of populating the *-oal file

  189834. **   using the formula:

  189835. **

  189836. **     permyriadage = (10000 * nProgress) / nPhaseOneStep

  189837. **

  189838. **   nPhaseOneStep is initialized to the sum of:

  189839. **

  189840. **     nRow * (nIndex + 1)

  189841. **

  189842. **   for all source tables in the RBU database, where nRow is the number

  189843. **   of rows in the source table and nIndex the number of indexes on the

  189844. **   corresponding target database table.

  189845. **

  189846. **   This estimate is accurate if the RBU update consists entirely of

  189847. **   INSERT operations. However, it is inaccurate if:

  189848. **

  189849. **     * the RBU update contains any UPDATE operations. If the PK specified

  189850. **       for an UPDATE operation does not exist in the target table, then

  189851. **       no b-tree operations are required on index b-trees. Or if the 

  189852. **       specified PK does exist, then (nIndex*2) such operations are

  189853. **       required (one delete and one insert on each index b-tree).

  189854. **

  189855. **     * the RBU update contains any DELETE operations for which the specified

  189856. **       PK does not exist. In this case no operations are required on index

  189857. **       b-trees.

  189858. **

  189859. **     * the RBU update contains REPLACE operations. These are similar to

  189860. **       UPDATE operations.

  189861. **

  189862. **   nPhaseOneStep is updated to account for the conditions above during the

  189863. **   first pass of each source table. The updated nPhaseOneStep value is

  189864. **   stored in the rbu_state table if the RBU update is suspended.

  189865. */

  189866. struct sqlite3rbu {

  189867.   int eStage;                     /* Value of RBU_STATE_STAGE field */

  189868.   sqlite3 *dbMain;                /* target database handle */

  189869.   sqlite3 *dbRbu;                 /* rbu database handle */

  189870.   char *zTarget;                  /* Path to target db */

  189871.   char *zRbu;                     /* Path to rbu db */

  189872.   char *zState;                   /* Path to state db (or NULL if zRbu) */

  189873.   char zStateDb[5];               /* Db name for state ("stat" or "main") */

  189874.   int rc;                         /* Value returned by last rbu_step() call */

  189875.   char *zErrmsg;                  /* Error message if rc!=SQLITE_OK */

  189876.   int nStep;                      /* Rows processed for current object */

  189877.   int nProgress;                  /* Rows processed for all objects */

  189878.   RbuObjIter objiter;             /* Iterator for skipping through tbl/idx */

  189879.   const char *zVfsName;           /* Name of automatically created rbu vfs */

  189880.   rbu_file *pTargetFd;            /* File handle open on target db */

  189881.   int nPagePerSector;             /* Pages per sector for pTargetFd */

  189882.   i64 iOalSz;

  189883.   i64 nPhaseOneStep;

  189884. 

  189885.   /* The following state variables are used as part of the incremental

  189886.   ** checkpoint stage (eStage==RBU_STAGE_CKPT). See comments surrounding

  189887.   ** function rbuSetupCheckpoint() for details.  */

  189888.   u32 iMaxFrame;                  /* Largest iWalFrame value in aFrame[] */

  189889.   u32 mLock;

  189890.   int nFrame;                     /* Entries in aFrame[] array */

  189891.   int nFrameAlloc;                /* Allocated size of aFrame[] array */

  189892.   RbuFrame *aFrame;

  189893.   int pgsz;

  189894.   u8 *aBuf;

  189895.   i64 iWalCksum;

  189896.   i64 szTemp;                     /* Current size of all temp files in use */

  189897.   i64 szTempLimit;                /* Total size limit for temp files */

  189898. 

  189899.   /* Used in RBU vacuum mode only */

  189900.   int nRbu;                       /* Number of RBU VFS in the stack */

  189901.   rbu_file *pRbuFd;               /* Fd for main db of dbRbu */

  189902. };

  189903. 

  189904. /*

  189905. ** An rbu VFS is implemented using an instance of this structure.

  189906. **

  189907. ** Variable pRbu is only non-NULL for automatically created RBU VFS objects.

  189908. ** It is NULL for RBU VFS objects created explicitly using

  189909. ** sqlite3rbu_create_vfs(). It is used to track the total amount of temp

  189910. ** space used by the RBU handle.

  189911. */

  189912. struct rbu_vfs {

  189913.   sqlite3_vfs base;               /* rbu VFS shim methods */

  189914.   sqlite3_vfs *pRealVfs;          /* Underlying VFS */

  189915.   sqlite3_mutex *mutex;           /* Mutex to protect pMain */

  189916.   sqlite3rbu *pRbu;               /* Owner RBU object */

  189917.   rbu_file *pMain;                /* List of main db files */

  189918.   rbu_file *pMainRbu;             /* List of main db files with pRbu!=0 */

  189919. };

  189920. 

  189921. /*

  189922. ** Each file opened by an rbu VFS is represented by an instance of

  189923. ** the following structure.

  189924. **

  189925. ** If this is a temporary file (pRbu!=0 && flags&DELETE_ON_CLOSE), variable

  189926. ** "sz" is set to the current size of the database file.

  189927. */

  189928. struct rbu_file {

  189929.   sqlite3_file base;              /* sqlite3_file methods */

  189930.   sqlite3_file *pReal;            /* Underlying file handle */

  189931.   rbu_vfs *pRbuVfs;               /* Pointer to the rbu_vfs object */

  189932.   sqlite3rbu *pRbu;               /* Pointer to rbu object (rbu target only) */

  189933.   i64 sz;                         /* Size of file in bytes (temp only) */

  189934. 

  189935.   int openFlags;                  /* Flags this file was opened with */

  189936.   u32 iCookie;                    /* Cookie value for main db files */

  189937.   u8 iWriteVer;                   /* "write-version" value for main db files */

  189938.   u8 bNolock;                     /* True to fail EXCLUSIVE locks */

  189939. 

  189940.   int nShm;                       /* Number of entries in apShm[] array */

  189941.   char **apShm;                   /* Array of mmap'd *-shm regions */

  189942.   char *zDel;                     /* Delete this when closing file */

  189943. 

  189944.   const char *zWal;               /* Wal filename for this main db file */

  189945.   rbu_file *pWalFd;               /* Wal file descriptor for this main db */

  189946.   rbu_file *pMainNext;            /* Next MAIN_DB file */

  189947.   rbu_file *pMainRbuNext;         /* Next MAIN_DB file with pRbu!=0 */

  189948. };

  189949. 

  189950. /*

  189951. ** True for an RBU vacuum handle, or false otherwise.

  189952. */

  189953. #define rbuIsVacuum(p) ((p)->zTarget==0)

  189954. 

  189955. 

  189956. /*************************************************************************

  189957. ** The following three functions, found below:

  189958. **

  189959. **   rbuDeltaGetInt()

  189960. **   rbuDeltaChecksum()

  189961. **   rbuDeltaApply()

  189962. **

  189963. ** are lifted from the fossil source code (http://fossil-scm.org). They

  189964. ** are used to implement the scalar SQL function rbu_fossil_delta().

  189965. */

  189966. 

  189967. /*

  189968. ** Read bytes from *pz and convert them into a positive integer.  When

  189969. ** finished, leave *pz pointing to the first character past the end of

  189970. ** the integer.  The *pLen parameter holds the length of the string

  189971. ** in *pz and is decremented once for each character in the integer.

  189972. */

  189973. static unsigned int rbuDeltaGetInt(const char **pz, int *pLen){

  189974.   static const signed char zValue[] = {

  189975.     -1, -1, -1, -1, -1, -1, -1, -1,   -1, -1, -1, -1, -1, -1, -1, -1,

  189976.     -1, -1, -1, -1, -1, -1, -1, -1,   -1, -1, -1, -1, -1, -1, -1, -1,

  189977.     -1, -1, -1, -1, -1, -1, -1, -1,   -1, -1, -1, -1, -1, -1, -1, -1,

  189978.      0,  1,  2,  3,  4,  5,  6,  7,    8,  9, -1, -1, -1, -1, -1, -1,

  189979.     -1, 10, 11, 12, 13, 14, 15, 16,   17, 18, 19, 20, 21, 22, 23, 24,

  189980.     25, 26, 27, 28, 29, 30, 31, 32,   33, 34, 35, -1, -1, -1, -1, 36,

  189981.     -1, 37, 38, 39, 40, 41, 42, 43,   44, 45, 46, 47, 48, 49, 50, 51,

  189982.     52, 53, 54, 55, 56, 57, 58, 59,   60, 61, 62, -1, -1, -1, 63, -1,

  189983.   };

  189984.   unsigned int v = 0;

  189985.   int c;

  189986.   unsigned char *z = (unsigned char*)*pz;

  189987.   unsigned char *zStart = z;

  189988.   while( (c = zValue[0x7f&*(z++)])>=0 ){

  189989.      v = (v<<6) + c;

  189990.   }

  189991.   z--;

  189992.   *pLen -= z - zStart;

  189993.   *pz = (char*)z;

  189994.   return v;

  189995. }

  189996. 

  189997. #if RBU_ENABLE_DELTA_CKSUM

  189998. /*

  189999. ** Compute a 32-bit checksum on the N-byte buffer.  Return the result.

  190000. */

  190001. static unsigned int rbuDeltaChecksum(const char *zIn, size_t N){

  190002.   const unsigned char *z = (const unsigned char *)zIn;

  190003.   unsigned sum0 = 0;

  190004.   unsigned sum1 = 0;

  190005.   unsigned sum2 = 0;

  190006.   unsigned sum3 = 0;

  190007.   while(N >= 16){

  190008.     sum0 += ((unsigned)z[0] + z[4] + z[8] + z[12]);

  190009.     sum1 += ((unsigned)z[1] + z[5] + z[9] + z[13]);

  190010.     sum2 += ((unsigned)z[2] + z[6] + z[10]+ z[14]);

  190011.     sum3 += ((unsigned)z[3] + z[7] + z[11]+ z[15]);

  190012.     z += 16;

  190013.     N -= 16;

  190014.   }

  190015.   while(N >= 4){

  190016.     sum0 += z[0];

  190017.     sum1 += z[1];

  190018.     sum2 += z[2];

  190019.     sum3 += z[3];

  190020.     z += 4;

  190021.     N -= 4;

  190022.   }

  190023.   sum3 += (sum2 << 8) + (sum1 << 16) + (sum0 << 24);

  190024.   switch(N){

  190025.     case 3:   sum3 += (z[2] << 8);

  190026.     case 2:   sum3 += (z[1] << 16);

  190027.     case 1:   sum3 += (z[0] << 24);

  190028.     default:  ;

  190029.   }

  190030.   return sum3;

  190031. }

  190032. #endif

  190033. 

  190034. /*

  190035. ** Apply a delta.

  190036. **

  190037. ** The output buffer should be big enough to hold the whole output

  190038. ** file and a NUL terminator at the end.  The delta_output_size()

  190039. ** routine will determine this size for you.

  190040. **

  190041. ** The delta string should be null-terminated.  But the delta string

  190042. ** may contain embedded NUL characters (if the input and output are

  190043. ** binary files) so we also have to pass in the length of the delta in

  190044. ** the lenDelta parameter.

  190045. **

  190046. ** This function returns the size of the output file in bytes (excluding

  190047. ** the final NUL terminator character).  Except, if the delta string is

  190048. ** malformed or intended for use with a source file other than zSrc,

  190049. ** then this routine returns -1.

  190050. **

  190051. ** Refer to the delta_create() documentation above for a description

  190052. ** of the delta file format.

  190053. */

  190054. static int rbuDeltaApply(

  190055.   const char *zSrc,      /* The source or pattern file */

  190056.   int lenSrc,            /* Length of the source file */

  190057.   const char *zDelta,    /* Delta to apply to the pattern */

  190058.   int lenDelta,          /* Length of the delta */

  190059.   char *zOut             /* Write the output into this preallocated buffer */

  190060. ){

  190061.   unsigned int limit;

  190062.   unsigned int total = 0;

  190063. #if RBU_ENABLE_DELTA_CKSUM

  190064.   char *zOrigOut = zOut;

  190065. #endif

  190066. 

  190067.   limit = rbuDeltaGetInt(&zDelta, &lenDelta);

  190068.   if( *zDelta!='\n' ){

  190069.     /* ERROR: size integer not terminated by "\n" */

  190070.     return -1;

  190071.   }

  190072.   zDelta++; lenDelta--;

  190073.   while( *zDelta && lenDelta>0 ){

  190074.     unsigned int cnt, ofst;

  190075.     cnt = rbuDeltaGetInt(&zDelta, &lenDelta);

  190076.     switch( zDelta[0] ){

  190077.       case '@': {

  190078.         zDelta++; lenDelta--;

  190079.         ofst = rbuDeltaGetInt(&zDelta, &lenDelta);

  190080.         if( lenDelta>0 && zDelta[0]!=',' ){

  190081.           /* ERROR: copy command not terminated by ',' */

  190082.           return -1;

  190083.         }

  190084.         zDelta++; lenDelta--;

  190085.         total += cnt;

  190086.         if( total>limit ){

  190087.           /* ERROR: copy exceeds output file size */

  190088.           return -1;

  190089.         }

  190090.         if( (int)(ofst+cnt) > lenSrc ){

  190091.           /* ERROR: copy extends past end of input */

  190092.           return -1;

  190093.         }

  190094.         memcpy(zOut, &zSrc[ofst], cnt);

  190095.         zOut += cnt;

  190096.         break;

  190097.       }

  190098.       case ':': {

  190099.         zDelta++; lenDelta--;

  190100.         total += cnt;

  190101.         if( total>limit ){

  190102.           /* ERROR:  insert command gives an output larger than predicted */

  190103.           return -1;

  190104.         }

  190105.         if( (int)cnt>lenDelta ){

  190106.           /* ERROR: insert count exceeds size of delta */

  190107.           return -1;

  190108.         }

  190109.         memcpy(zOut, zDelta, cnt);

  190110.         zOut += cnt;

  190111.         zDelta += cnt;

  190112.         lenDelta -= cnt;

  190113.         break;

  190114.       }

  190115.       case ';': {

  190116.         zDelta++; lenDelta--;

  190117.         zOut[0] = 0;

  190118. #if RBU_ENABLE_DELTA_CKSUM

  190119.         if( cnt!=rbuDeltaChecksum(zOrigOut, total) ){

  190120.           /* ERROR:  bad checksum */

  190121.           return -1;

  190122.         }

  190123. #endif

  190124.         if( total!=limit ){

  190125.           /* ERROR: generated size does not match predicted size */

  190126.           return -1;

  190127.         }

  190128.         return total;

  190129.       }

  190130.       default: {

  190131.         /* ERROR: unknown delta operator */

  190132.         return -1;

  190133.       }

  190134.     }

  190135.   }

  190136.   /* ERROR: unterminated delta */

  190137.   return -1;

  190138. }

  190139. 

  190140. static int rbuDeltaOutputSize(const char *zDelta, int lenDelta){

  190141.   int size;

  190142.   size = rbuDeltaGetInt(&zDelta, &lenDelta);

  190143.   if( *zDelta!='\n' ){

  190144.     /* ERROR: size integer not terminated by "\n" */

  190145.     return -1;

  190146.   }

  190147.   return size;

  190148. }

  190149. 

  190150. /*

  190151. ** End of code taken from fossil.

  190152. *************************************************************************/

  190153. 

  190154. /*

  190155. ** Implementation of SQL scalar function rbu_fossil_delta().

  190156. **

  190157. ** This function applies a fossil delta patch to a blob. Exactly two

  190158. ** arguments must be passed to this function. The first is the blob to

  190159. ** patch and the second the patch to apply. If no error occurs, this

  190160. ** function returns the patched blob.

  190161. */

  190162. static void rbuFossilDeltaFunc(

  190163.   sqlite3_context *context,

  190164.   int argc,

  190165.   sqlite3_value **argv

  190166. ){

  190167.   const char *aDelta;

  190168.   int nDelta;

  190169.   const char *aOrig;

  190170.   int nOrig;

  190171. 

  190172.   int nOut;

  190173.   int nOut2;

  190174.   char *aOut;

  190175. 

  190176.   assert( argc==2 );

  190177. 

  190178.   nOrig = sqlite3_value_bytes(argv[0]);

  190179.   aOrig = (const char*)sqlite3_value_blob(argv[0]);

  190180.   nDelta = sqlite3_value_bytes(argv[1]);

  190181.   aDelta = (const char*)sqlite3_value_blob(argv[1]);

  190182. 

  190183.   /* Figure out the size of the output */

  190184.   nOut = rbuDeltaOutputSize(aDelta, nDelta);

  190185.   if( nOut<0 ){

  190186.     sqlite3_result_error(context, "corrupt fossil delta", -1);

  190187.     return;

  190188.   }

  190189. 

  190190.   aOut = sqlite3_malloc(nOut+1);

  190191.   if( aOut==0 ){

  190192.     sqlite3_result_error_nomem(context);

  190193.   }else{

  190194.     nOut2 = rbuDeltaApply(aOrig, nOrig, aDelta, nDelta, aOut);

  190195.     if( nOut2!=nOut ){

  190196.       sqlite3_free(aOut);

  190197.       sqlite3_result_error(context, "corrupt fossil delta", -1);

  190198.     }else{

  190199.       sqlite3_result_blob(context, aOut, nOut, sqlite3_free);

  190200.     }

  190201.   }

  190202. }

  190203. 

  190204. 

  190205. /*

  190206. ** Prepare the SQL statement in buffer zSql against database handle db.

  190207. ** If successful, set *ppStmt to point to the new statement and return

  190208. ** SQLITE_OK. 

  190209. **

  190210. ** Otherwise, if an error does occur, set *ppStmt to NULL and return

  190211. ** an SQLite error code. Additionally, set output variable *pzErrmsg to

  190212. ** point to a buffer containing an error message. It is the responsibility

  190213. ** of the caller to (eventually) free this buffer using sqlite3_free().

  190214. */

  190215. static int prepareAndCollectError(

  190216.   sqlite3 *db, 

  190217.   sqlite3_stmt **ppStmt,

  190218.   char **pzErrmsg,

  190219.   const char *zSql

  190220. ){

  190221.   int rc = sqlite3_prepare_v2(db, zSql, -1, ppStmt, 0);

  190222.   if( rc!=SQLITE_OK ){

  190223.     *pzErrmsg = sqlite3_mprintf("%s", sqlite3_errmsg(db));

  190224.     *ppStmt = 0;

  190225.   }

  190226.   return rc;

  190227. }

  190228. 

  190229. /*

  190230. ** Reset the SQL statement passed as the first argument. Return a copy

  190231. ** of the value returned by sqlite3_reset().

  190232. **

  190233. ** If an error has occurred, then set *pzErrmsg to point to a buffer

  190234. ** containing an error message. It is the responsibility of the caller

  190235. ** to eventually free this buffer using sqlite3_free().

  190236. */

  190237. static int resetAndCollectError(sqlite3_stmt *pStmt, char **pzErrmsg){

  190238.   int rc = sqlite3_reset(pStmt);

  190239.   if( rc!=SQLITE_OK ){

  190240.     *pzErrmsg = sqlite3_mprintf("%s", sqlite3_errmsg(sqlite3_db_handle(pStmt)));

  190241.   }

  190242.   return rc;

  190243. }

  190244. 

  190245. /*

  190246. ** Unless it is NULL, argument zSql points to a buffer allocated using

  190247. ** sqlite3_malloc containing an SQL statement. This function prepares the SQL

  190248. ** statement against database db and frees the buffer. If statement 

  190249. ** compilation is successful, *ppStmt is set to point to the new statement 

  190250. ** handle and SQLITE_OK is returned. 

  190251. **

  190252. ** Otherwise, if an error occurs, *ppStmt is set to NULL and an error code

  190253. ** returned. In this case, *pzErrmsg may also be set to point to an error

  190254. ** message. It is the responsibility of the caller to free this error message

  190255. ** buffer using sqlite3_free().

  190256. **

  190257. ** If argument zSql is NULL, this function assumes that an OOM has occurred.

  190258. ** In this case SQLITE_NOMEM is returned and *ppStmt set to NULL.

  190259. */

  190260. static int prepareFreeAndCollectError(

  190261.   sqlite3 *db, 

  190262.   sqlite3_stmt **ppStmt,

  190263.   char **pzErrmsg,

  190264.   char *zSql

  190265. ){

  190266.   int rc;

  190267.   assert( *pzErrmsg==0 );

  190268.   if( zSql==0 ){

  190269.     rc = SQLITE_NOMEM;

  190270.     *ppStmt = 0;

  190271.   }else{

  190272.     rc = prepareAndCollectError(db, ppStmt, pzErrmsg, zSql);

  190273.     sqlite3_free(zSql);

  190274.   }

  190275.   return rc;

  190276. }

  190277. 

  190278. /*

  190279. ** Free the RbuObjIter.azTblCol[] and RbuObjIter.abTblPk[] arrays allocated

  190280. ** by an earlier call to rbuObjIterCacheTableInfo().

  190281. */

  190282. static void rbuObjIterFreeCols(RbuObjIter *pIter){

  190283.   int i;

  190284.   for(i=0; i<pIter->nTblCol; i++){

  190285.     sqlite3_free(pIter->azTblCol[i]);

  190286.     sqlite3_free(pIter->azTblType[i]);

  190287.   }

  190288.   sqlite3_free(pIter->azTblCol);

  190289.   pIter->azTblCol = 0;

  190290.   pIter->azTblType = 0;

  190291.   pIter->aiSrcOrder = 0;

  190292.   pIter->abTblPk = 0;

  190293.   pIter->abNotNull = 0;

  190294.   pIter->nTblCol = 0;

  190295.   pIter->eType = 0;               /* Invalid value */

  190296. }

  190297. 

  190298. /*

  190299. ** Finalize all statements and free all allocations that are specific to

  190300. ** the current object (table/index pair).

  190301. */

  190302. static void rbuObjIterClearStatements(RbuObjIter *pIter){

  190303.   RbuUpdateStmt *pUp;

  190304. 

  190305.   sqlite3_finalize(pIter->pSelect);

  190306.   sqlite3_finalize(pIter->pInsert);

  190307.   sqlite3_finalize(pIter->pDelete);

  190308.   sqlite3_finalize(pIter->pTmpInsert);

  190309.   pUp = pIter->pRbuUpdate;

  190310.   while( pUp ){

  190311.     RbuUpdateStmt *pTmp = pUp->pNext;

  190312.     sqlite3_finalize(pUp->pUpdate);

  190313.     sqlite3_free(pUp);

  190314.     pUp = pTmp;

  190315.   }

  190316.   

  190317.   pIter->pSelect = 0;

  190318.   pIter->pInsert = 0;

  190319.   pIter->pDelete = 0;

  190320.   pIter->pRbuUpdate = 0;

  190321.   pIter->pTmpInsert = 0;

  190322.   pIter->nCol = 0;

  190323. }

  190324. 

  190325. /*

  190326. ** Clean up any resources allocated as part of the iterator object passed

  190327. ** as the only argument.

  190328. */

  190329. static void rbuObjIterFinalize(RbuObjIter *pIter){

  190330.   rbuObjIterClearStatements(pIter);

  190331.   sqlite3_finalize(pIter->pTblIter);

  190332.   sqlite3_finalize(pIter->pIdxIter);

  190333.   rbuObjIterFreeCols(pIter);

  190334.   memset(pIter, 0, sizeof(RbuObjIter));

  190335. }

  190336. 

  190337. /*

  190338. ** Advance the iterator to the next position.

  190339. **

  190340. ** If no error occurs, SQLITE_OK is returned and the iterator is left 

  190341. ** pointing to the next entry. Otherwise, an error code and message is 

  190342. ** left in the RBU handle passed as the first argument. A copy of the 

  190343. ** error code is returned.

  190344. */

  190345. static int rbuObjIterNext(sqlite3rbu *p, RbuObjIter *pIter){

  190346.   int rc = p->rc;

  190347.   if( rc==SQLITE_OK ){

  190348. 

  190349.     /* Free any SQLite statements used while processing the previous object */ 

  190350.     rbuObjIterClearStatements(pIter);

  190351.     if( pIter->zIdx==0 ){

  190352.       rc = sqlite3_exec(p->dbMain,

  190353.           "DROP TRIGGER IF EXISTS temp.rbu_insert_tr;"

  190354.           "DROP TRIGGER IF EXISTS temp.rbu_update1_tr;"

  190355.           "DROP TRIGGER IF EXISTS temp.rbu_update2_tr;"

  190356.           "DROP TRIGGER IF EXISTS temp.rbu_delete_tr;"

  190357.           , 0, 0, &p->zErrmsg

  190358.       );

  190359.     }

  190360. 

  190361.     if( rc==SQLITE_OK ){

  190362.       if( pIter->bCleanup ){

  190363.         rbuObjIterFreeCols(pIter);

  190364.         pIter->bCleanup = 0;

  190365.         rc = sqlite3_step(pIter->pTblIter);

  190366.         if( rc!=SQLITE_ROW ){

  190367.           rc = resetAndCollectError(pIter->pTblIter, &p->zErrmsg);

  190368.           pIter->zTbl = 0;

  190369.         }else{

  190370.           pIter->zTbl = (const char*)sqlite3_column_text(pIter->pTblIter, 0);

  190371.           pIter->zDataTbl = (const char*)sqlite3_column_text(pIter->pTblIter,1);

  190372.           rc = (pIter->zDataTbl && pIter->zTbl) ? SQLITE_OK : SQLITE_NOMEM;

  190373.         }

  190374.       }else{

  190375.         if( pIter->zIdx==0 ){

  190376.           sqlite3_stmt *pIdx = pIter->pIdxIter;

  190377.           rc = sqlite3_bind_text(pIdx, 1, pIter->zTbl, -1, SQLITE_STATIC);

  190378.         }

  190379.         if( rc==SQLITE_OK ){

  190380.           rc = sqlite3_step(pIter->pIdxIter);

  190381.           if( rc!=SQLITE_ROW ){

  190382.             rc = resetAndCollectError(pIter->pIdxIter, &p->zErrmsg);

  190383.             pIter->bCleanup = 1;

  190384.             pIter->zIdx = 0;

  190385.           }else{

  190386.             pIter->zIdx = (const char*)sqlite3_column_text(pIter->pIdxIter, 0);

  190387.             pIter->iTnum = sqlite3_column_int(pIter->pIdxIter, 1);

  190388.             pIter->bUnique = sqlite3_column_int(pIter->pIdxIter, 2);

  190389.             rc = pIter->zIdx ? SQLITE_OK : SQLITE_NOMEM;

  190390.           }

  190391.         }

  190392.       }

  190393.     }

  190394.   }

  190395. 

  190396.   if( rc!=SQLITE_OK ){

  190397.     rbuObjIterFinalize(pIter);

  190398.     p->rc = rc;

  190399.   }

  190400.   return rc;

  190401. }

  190402. 

  190403. 

  190404. /*

  190405. ** The implementation of the rbu_target_name() SQL function. This function

  190406. ** accepts one or two arguments. The first argument is the name of a table -

  190407. ** the name of a table in the RBU database.  The second, if it is present, is 1

  190408. ** for a view or 0 for a table. 

  190409. **

  190410. ** For a non-vacuum RBU handle, if the table name matches the pattern:

  190411. **

  190412. **     data[0-9]_<name>

  190413. **

  190414. ** where <name> is any sequence of 1 or more characters, <name> is returned.

  190415. ** Otherwise, if the only argument does not match the above pattern, an SQL

  190416. ** NULL is returned.

  190417. **

  190418. **     "data_t1"     -> "t1"

  190419. **     "data0123_t2" -> "t2"

  190420. **     "dataAB_t3"   -> NULL

  190421. **

  190422. ** For an rbu vacuum handle, a copy of the first argument is returned if

  190423. ** the second argument is either missing or 0 (not a view).

  190424. */

  190425. static void rbuTargetNameFunc(

  190426.   sqlite3_context *pCtx,

  190427.   int argc,

  190428.   sqlite3_value **argv

  190429. ){

  190430.   sqlite3rbu *p = sqlite3_user_data(pCtx);

  190431.   const char *zIn;

  190432.   assert( argc==1 || argc==2 );

  190433. 

  190434.   zIn = (const char*)sqlite3_value_text(argv[0]);

  190435.   if( zIn ){

  190436.     if( rbuIsVacuum(p) ){

  190437.       assert( argc==2 );

  190438.       if( 0==sqlite3_value_int(argv[1]) ){

  190439.         sqlite3_result_text(pCtx, zIn, -1, SQLITE_STATIC);

  190440.       }

  190441.     }else{

  190442.       if( strlen(zIn)>4 && memcmp("data", zIn, 4)==0 ){

  190443.         int i;

  190444.         for(i=4; zIn[i]>='0' && zIn[i]<='9'; i++);

  190445.         if( zIn[i]=='_' && zIn[i+1] ){

  190446.           sqlite3_result_text(pCtx, &zIn[i+1], -1, SQLITE_STATIC);

  190447.         }

  190448.       }

  190449.     }

  190450.   }

  190451. }

  190452. 

  190453. /*

  190454. ** Initialize the iterator structure passed as the second argument.

  190455. **

  190456. ** If no error occurs, SQLITE_OK is returned and the iterator is left 

  190457. ** pointing to the first entry. Otherwise, an error code and message is 

  190458. ** left in the RBU handle passed as the first argument. A copy of the 

  190459. ** error code is returned.

  190460. */

  190461. static int rbuObjIterFirst(sqlite3rbu *p, RbuObjIter *pIter){

  190462.   int rc;

  190463.   memset(pIter, 0, sizeof(RbuObjIter));

  190464. 

  190465.   rc = prepareFreeAndCollectError(p->dbRbu, &pIter->pTblIter, &p->zErrmsg, 

  190466.     sqlite3_mprintf(

  190467.       "SELECT rbu_target_name(name, type='view') AS target, name "

  190468.       "FROM sqlite_master "

  190469.       "WHERE type IN ('table', 'view') AND target IS NOT NULL "

  190470.       " %s "

  190471.       "ORDER BY name"

  190472.   , rbuIsVacuum(p) ? "AND rootpage!=0 AND rootpage IS NOT NULL" : ""));

  190473. 

  190474.   if( rc==SQLITE_OK ){

  190475.     rc = prepareAndCollectError(p->dbMain, &pIter->pIdxIter, &p->zErrmsg,

  190476.         "SELECT name, rootpage, sql IS NULL OR substr(8, 6)=='UNIQUE' "

  190477.         "  FROM main.sqlite_master "

  190478.         "  WHERE type='index' AND tbl_name = ?"

  190479.     );

  190480.   }

  190481. 

  190482.   pIter->bCleanup = 1;

  190483.   p->rc = rc;

  190484.   return rbuObjIterNext(p, pIter);

  190485. }

  190486. 

  190487. /*

  190488. ** This is a wrapper around "sqlite3_mprintf(zFmt, ...)". If an OOM occurs,

  190489. ** an error code is stored in the RBU handle passed as the first argument.

  190490. **

  190491. ** If an error has already occurred (p->rc is already set to something other

  190492. ** than SQLITE_OK), then this function returns NULL without modifying the

  190493. ** stored error code. In this case it still calls sqlite3_free() on any 

  190494. ** printf() parameters associated with %z conversions.

  190495. */

  190496. static char *rbuMPrintf(sqlite3rbu *p, const char *zFmt, ...){

  190497.   char *zSql = 0;

  190498.   va_list ap;

  190499.   va_start(ap, zFmt);

  190500.   zSql = sqlite3_vmprintf(zFmt, ap);

  190501.   if( p->rc==SQLITE_OK ){

  190502.     if( zSql==0 ) p->rc = SQLITE_NOMEM;

  190503.   }else{

  190504.     sqlite3_free(zSql);

  190505.     zSql = 0;

  190506.   }

  190507.   va_end(ap);

  190508.   return zSql;

  190509. }

  190510. 

  190511. /*

  190512. ** Argument zFmt is a sqlite3_mprintf() style format string. The trailing

  190513. ** arguments are the usual subsitution values. This function performs

  190514. ** the printf() style substitutions and executes the result as an SQL

  190515. ** statement on the RBU handles database.

  190516. **

  190517. ** If an error occurs, an error code and error message is stored in the

  190518. ** RBU handle. If an error has already occurred when this function is

  190519. ** called, it is a no-op.

  190520. */

  190521. static int rbuMPrintfExec(sqlite3rbu *p, sqlite3 *db, const char *zFmt, ...){

  190522.   va_list ap;

  190523.   char *zSql;

  190524.   va_start(ap, zFmt);

  190525.   zSql = sqlite3_vmprintf(zFmt, ap);

  190526.   if( p->rc==SQLITE_OK ){

  190527.     if( zSql==0 ){

  190528.       p->rc = SQLITE_NOMEM;

  190529.     }else{

  190530.       p->rc = sqlite3_exec(db, zSql, 0, 0, &p->zErrmsg);

  190531.     }

  190532.   }

  190533.   sqlite3_free(zSql);

  190534.   va_end(ap);

  190535.   return p->rc;

  190536. }

  190537. 

  190538. /*

  190539. ** Attempt to allocate and return a pointer to a zeroed block of nByte 

  190540. ** bytes. 

  190541. **

  190542. ** If an error (i.e. an OOM condition) occurs, return NULL and leave an 

  190543. ** error code in the rbu handle passed as the first argument. Or, if an 

  190544. ** error has already occurred when this function is called, return NULL 

  190545. ** immediately without attempting the allocation or modifying the stored

  190546. ** error code.

  190547. */

  190548. static void *rbuMalloc(sqlite3rbu *p, sqlite3_int64 nByte){

  190549.   void *pRet = 0;

  190550.   if( p->rc==SQLITE_OK ){

  190551.     assert( nByte>0 );

  190552.     pRet = sqlite3_malloc64(nByte);

  190553.     if( pRet==0 ){

  190554.       p->rc = SQLITE_NOMEM;

  190555.     }else{

  190556.       memset(pRet, 0, nByte);

  190557.     }

  190558.   }

  190559.   return pRet;

  190560. }

  190561. 

  190562. 

  190563. /*

  190564. ** Allocate and zero the pIter->azTblCol[] and abTblPk[] arrays so that

  190565. ** there is room for at least nCol elements. If an OOM occurs, store an

  190566. ** error code in the RBU handle passed as the first argument.

  190567. */

  190568. static void rbuAllocateIterArrays(sqlite3rbu *p, RbuObjIter *pIter, int nCol){

  190569.   sqlite3_int64 nByte = (2*sizeof(char*) + sizeof(int) + 3*sizeof(u8)) * nCol;

  190570.   char **azNew;

  190571. 

  190572.   azNew = (char**)rbuMalloc(p, nByte);

  190573.   if( azNew ){

  190574.     pIter->azTblCol = azNew;

  190575.     pIter->azTblType = &azNew[nCol];

  190576.     pIter->aiSrcOrder = (int*)&pIter->azTblType[nCol];

  190577.     pIter->abTblPk = (u8*)&pIter->aiSrcOrder[nCol];

  190578.     pIter->abNotNull = (u8*)&pIter->abTblPk[nCol];

  190579.     pIter->abIndexed = (u8*)&pIter->abNotNull[nCol];

  190580.   }

  190581. }

  190582. 

  190583. /*

  190584. ** The first argument must be a nul-terminated string. This function

  190585. ** returns a copy of the string in memory obtained from sqlite3_malloc().

  190586. ** It is the responsibility of the caller to eventually free this memory

  190587. ** using sqlite3_free().

  190588. **

  190589. ** If an OOM condition is encountered when attempting to allocate memory,

  190590. ** output variable (*pRc) is set to SQLITE_NOMEM before returning. Otherwise,

  190591. ** if the allocation succeeds, (*pRc) is left unchanged.

  190592. */

  190593. static char *rbuStrndup(const char *zStr, int *pRc){

  190594.   char *zRet = 0;

  190595. 

  190596.   assert( *pRc==SQLITE_OK );

  190597.   if( zStr ){

  190598.     size_t nCopy = strlen(zStr) + 1;

  190599.     zRet = (char*)sqlite3_malloc64(nCopy);

  190600.     if( zRet ){

  190601.       memcpy(zRet, zStr, nCopy);

  190602.     }else{

  190603.       *pRc = SQLITE_NOMEM;

  190604.     }

  190605.   }

  190606. 

  190607.   return zRet;

  190608. }

  190609. 

  190610. /*

  190611. ** Finalize the statement passed as the second argument.

  190612. **

  190613. ** If the sqlite3_finalize() call indicates that an error occurs, and the

  190614. ** rbu handle error code is not already set, set the error code and error

  190615. ** message accordingly.

  190616. */

  190617. static void rbuFinalize(sqlite3rbu *p, sqlite3_stmt *pStmt){

  190618.   sqlite3 *db = sqlite3_db_handle(pStmt);

  190619.   int rc = sqlite3_finalize(pStmt);

  190620.   if( p->rc==SQLITE_OK && rc!=SQLITE_OK ){

  190621.     p->rc = rc;

  190622.     p->zErrmsg = sqlite3_mprintf("%s", sqlite3_errmsg(db));

  190623.   }

  190624. }

  190625. 

  190626. /* Determine the type of a table.

  190627. **

  190628. **   peType is of type (int*), a pointer to an output parameter of type

  190629. **   (int). This call sets the output parameter as follows, depending

  190630. **   on the type of the table specified by parameters dbName and zTbl.

  190631. **

  190632. **     RBU_PK_NOTABLE:       No such table.

  190633. **     RBU_PK_NONE:          Table has an implicit rowid.

  190634. **     RBU_PK_IPK:           Table has an explicit IPK column.

  190635. **     RBU_PK_EXTERNAL:      Table has an external PK index.

  190636. **     RBU_PK_WITHOUT_ROWID: Table is WITHOUT ROWID.

  190637. **     RBU_PK_VTAB:          Table is a virtual table.

  190638. **

  190639. **   Argument *piPk is also of type (int*), and also points to an output

  190640. **   parameter. Unless the table has an external primary key index 

  190641. **   (i.e. unless *peType is set to 3), then *piPk is set to zero. Or,

  190642. **   if the table does have an external primary key index, then *piPk

  190643. **   is set to the root page number of the primary key index before

  190644. **   returning.

  190645. **

  190646. ** ALGORITHM:

  190647. **

  190648. **   if( no entry exists in sqlite_master ){

  190649. **     return RBU_PK_NOTABLE

  190650. **   }else if( sql for the entry starts with "CREATE VIRTUAL" ){

  190651. **     return RBU_PK_VTAB

  190652. **   }else if( "PRAGMA index_list()" for the table contains a "pk" index ){

  190653. **     if( the index that is the pk exists in sqlite_master ){

  190654. **       *piPK = rootpage of that index.

  190655. **       return RBU_PK_EXTERNAL

  190656. **     }else{

  190657. **       return RBU_PK_WITHOUT_ROWID

  190658. **     }

  190659. **   }else if( "PRAGMA table_info()" lists one or more "pk" columns ){

  190660. **     return RBU_PK_IPK

  190661. **   }else{

  190662. **     return RBU_PK_NONE

  190663. **   }

  190664. */

  190665. static void rbuTableType(

  190666.   sqlite3rbu *p,

  190667.   const char *zTab,

  190668.   int *peType,

  190669.   int *piTnum,

  190670.   int *piPk

  190671. ){

  190672.   /*

  190673.   ** 0) SELECT count(*) FROM sqlite_master where name=%Q AND IsVirtual(%Q)

  190674.   ** 1) PRAGMA index_list = ?

  190675.   ** 2) SELECT count(*) FROM sqlite_master where name=%Q 

  190676.   ** 3) PRAGMA table_info = ?

  190677.   */

  190678.   sqlite3_stmt *aStmt[4] = {0, 0, 0, 0};

  190679. 

  190680.   *peType = RBU_PK_NOTABLE;

  190681.   *piPk = 0;

  190682. 

  190683.   assert( p->rc==SQLITE_OK );

  190684.   p->rc = prepareFreeAndCollectError(p->dbMain, &aStmt[0], &p->zErrmsg, 

  190685.     sqlite3_mprintf(

  190686.           "SELECT (sql LIKE 'create virtual%%'), rootpage"

  190687.           "  FROM sqlite_master"

  190688.           " WHERE name=%Q", zTab

  190689.   ));

  190690.   if( p->rc!=SQLITE_OK || sqlite3_step(aStmt[0])!=SQLITE_ROW ){

  190691.     /* Either an error, or no such table. */

  190692.     goto rbuTableType_end;

  190693.   }

  190694.   if( sqlite3_column_int(aStmt[0], 0) ){

  190695.     *peType = RBU_PK_VTAB;                     /* virtual table */

  190696.     goto rbuTableType_end;

  190697.   }

  190698.   *piTnum = sqlite3_column_int(aStmt[0], 1);

  190699. 

  190700.   p->rc = prepareFreeAndCollectError(p->dbMain, &aStmt[1], &p->zErrmsg, 

  190701.     sqlite3_mprintf("PRAGMA index_list=%Q",zTab)

  190702.   );

  190703.   if( p->rc ) goto rbuTableType_end;

  190704.   while( sqlite3_step(aStmt[1])==SQLITE_ROW ){

  190705.     const u8 *zOrig = sqlite3_column_text(aStmt[1], 3);

  190706.     const u8 *zIdx = sqlite3_column_text(aStmt[1], 1);

  190707.     if( zOrig && zIdx && zOrig[0]=='p' ){

  190708.       p->rc = prepareFreeAndCollectError(p->dbMain, &aStmt[2], &p->zErrmsg, 

  190709.           sqlite3_mprintf(

  190710.             "SELECT rootpage FROM sqlite_master WHERE name = %Q", zIdx

  190711.       ));

  190712.       if( p->rc==SQLITE_OK ){

  190713.         if( sqlite3_step(aStmt[2])==SQLITE_ROW ){

  190714.           *piPk = sqlite3_column_int(aStmt[2], 0);

  190715.           *peType = RBU_PK_EXTERNAL;

  190716.         }else{

  190717.           *peType = RBU_PK_WITHOUT_ROWID;

  190718.         }

  190719.       }

  190720.       goto rbuTableType_end;

  190721.     }

  190722.   }

  190723. 

  190724.   p->rc = prepareFreeAndCollectError(p->dbMain, &aStmt[3], &p->zErrmsg, 

  190725.     sqlite3_mprintf("PRAGMA table_info=%Q",zTab)

  190726.   );

  190727.   if( p->rc==SQLITE_OK ){

  190728.     while( sqlite3_step(aStmt[3])==SQLITE_ROW ){

  190729.       if( sqlite3_column_int(aStmt[3],5)>0 ){

  190730.         *peType = RBU_PK_IPK;                /* explicit IPK column */

  190731.         goto rbuTableType_end;

  190732.       }

  190733.     }

  190734.     *peType = RBU_PK_NONE;

  190735.   }

  190736. 

  190737. rbuTableType_end: {

  190738.     unsigned int i;

  190739.     for(i=0; i<sizeof(aStmt)/sizeof(aStmt[0]); i++){

  190740.       rbuFinalize(p, aStmt[i]);

  190741.     }

  190742.   }

  190743. }

  190744. 

  190745. /*

  190746. ** This is a helper function for rbuObjIterCacheTableInfo(). It populates

  190747. ** the pIter->abIndexed[] array.

  190748. */

  190749. static void rbuObjIterCacheIndexedCols(sqlite3rbu *p, RbuObjIter *pIter){

  190750.   sqlite3_stmt *pList = 0;

  190751.   int bIndex = 0;

  190752. 

  190753.   if( p->rc==SQLITE_OK ){

  190754.     memcpy(pIter->abIndexed, pIter->abTblPk, sizeof(u8)*pIter->nTblCol);

  190755.     p->rc = prepareFreeAndCollectError(p->dbMain, &pList, &p->zErrmsg,

  190756.         sqlite3_mprintf("PRAGMA main.index_list = %Q", pIter->zTbl)

  190757.     );

  190758.   }

  190759. 

  190760.   pIter->nIndex = 0;

  190761.   while( p->rc==SQLITE_OK && SQLITE_ROW==sqlite3_step(pList) ){

  190762.     const char *zIdx = (const char*)sqlite3_column_text(pList, 1);

  190763.     int bPartial = sqlite3_column_int(pList, 4);

  190764.     sqlite3_stmt *pXInfo = 0;

  190765.     if( zIdx==0 ) break;

  190766.     if( bPartial ){

  190767.       memset(pIter->abIndexed, 0x01, sizeof(u8)*pIter->nTblCol);

  190768.     }

  190769.     p->rc = prepareFreeAndCollectError(p->dbMain, &pXInfo, &p->zErrmsg,

  190770.         sqlite3_mprintf("PRAGMA main.index_xinfo = %Q", zIdx)

  190771.     );

  190772.     while( p->rc==SQLITE_OK && SQLITE_ROW==sqlite3_step(pXInfo) ){

  190773.       int iCid = sqlite3_column_int(pXInfo, 1);

  190774.       if( iCid>=0 ) pIter->abIndexed[iCid] = 1;

  190775.     }

  190776.     rbuFinalize(p, pXInfo);

  190777.     bIndex = 1;

  190778.     pIter->nIndex++;

  190779.   }

  190780. 

  190781.   if( pIter->eType==RBU_PK_WITHOUT_ROWID ){

  190782.     /* "PRAGMA index_list" includes the main PK b-tree */

  190783.     pIter->nIndex--;

  190784.   }

  190785. 

  190786.   rbuFinalize(p, pList);

  190787.   if( bIndex==0 ) pIter->abIndexed = 0;

  190788. }

  190789. 

  190790. 

  190791. /*

  190792. ** If they are not already populated, populate the pIter->azTblCol[],

  190793. ** pIter->abTblPk[], pIter->nTblCol and pIter->bRowid variables according to

  190794. ** the table (not index) that the iterator currently points to.

  190795. **

  190796. ** Return SQLITE_OK if successful, or an SQLite error code otherwise. If

  190797. ** an error does occur, an error code and error message are also left in 

  190798. ** the RBU handle.

  190799. */

  190800. static int rbuObjIterCacheTableInfo(sqlite3rbu *p, RbuObjIter *pIter){

  190801.   if( pIter->azTblCol==0 ){

  190802.     sqlite3_stmt *pStmt = 0;

  190803.     int nCol = 0;

  190804.     int i;                        /* for() loop iterator variable */

  190805.     int bRbuRowid = 0;            /* If input table has column "rbu_rowid" */

  190806.     int iOrder = 0;

  190807.     int iTnum = 0;

  190808. 

  190809.     /* Figure out the type of table this step will deal with. */

  190810.     assert( pIter->eType==0 );

  190811.     rbuTableType(p, pIter->zTbl, &pIter->eType, &iTnum, &pIter->iPkTnum);

  190812.     if( p->rc==SQLITE_OK && pIter->eType==RBU_PK_NOTABLE ){

  190813.       p->rc = SQLITE_ERROR;

  190814.       p->zErrmsg = sqlite3_mprintf("no such table: %s", pIter->zTbl);

  190815.     }

  190816.     if( p->rc ) return p->rc;

  190817.     if( pIter->zIdx==0 ) pIter->iTnum = iTnum;

  190818. 

  190819.     assert( pIter->eType==RBU_PK_NONE || pIter->eType==RBU_PK_IPK 

  190820.          || pIter->eType==RBU_PK_EXTERNAL || pIter->eType==RBU_PK_WITHOUT_ROWID

  190821.          || pIter->eType==RBU_PK_VTAB

  190822.     );

  190823. 

  190824.     /* Populate the azTblCol[] and nTblCol variables based on the columns

  190825.     ** of the input table. Ignore any input table columns that begin with

  190826.     ** "rbu_".  */

  190827.     p->rc = prepareFreeAndCollectError(p->dbRbu, &pStmt, &p->zErrmsg, 

  190828.         sqlite3_mprintf("SELECT * FROM '%q'", pIter->zDataTbl)

  190829.     );

  190830.     if( p->rc==SQLITE_OK ){

  190831.       nCol = sqlite3_column_count(pStmt);

  190832.       rbuAllocateIterArrays(p, pIter, nCol);

  190833.     }

  190834.     for(i=0; p->rc==SQLITE_OK && i<nCol; i++){

  190835.       const char *zName = (const char*)sqlite3_column_name(pStmt, i);

  190836.       if( sqlite3_strnicmp("rbu_", zName, 4) ){

  190837.         char *zCopy = rbuStrndup(zName, &p->rc);

  190838.         pIter->aiSrcOrder[pIter->nTblCol] = pIter->nTblCol;

  190839.         pIter->azTblCol[pIter->nTblCol++] = zCopy;

  190840.       }

  190841.       else if( 0==sqlite3_stricmp("rbu_rowid", zName) ){

  190842.         bRbuRowid = 1;

  190843.       }

  190844.     }

  190845.     sqlite3_finalize(pStmt);

  190846.     pStmt = 0;

  190847. 

  190848.     if( p->rc==SQLITE_OK

  190849.      && rbuIsVacuum(p)==0

  190850.      && bRbuRowid!=(pIter->eType==RBU_PK_VTAB || pIter->eType==RBU_PK_NONE)

  190851.     ){

  190852.       p->rc = SQLITE_ERROR;

  190853.       p->zErrmsg = sqlite3_mprintf(

  190854.           "table %q %s rbu_rowid column", pIter->zDataTbl,

  190855.           (bRbuRowid ? "may not have" : "requires")

  190856.       );

  190857.     }

  190858. 

  190859.     /* Check that all non-HIDDEN columns in the destination table are also

  190860.     ** present in the input table. Populate the abTblPk[], azTblType[] and

  190861.     ** aiTblOrder[] arrays at the same time.  */

  190862.     if( p->rc==SQLITE_OK ){

  190863.       p->rc = prepareFreeAndCollectError(p->dbMain, &pStmt, &p->zErrmsg, 

  190864.           sqlite3_mprintf("PRAGMA table_info(%Q)", pIter->zTbl)

  190865.       );

  190866.     }

  190867.     while( p->rc==SQLITE_OK && SQLITE_ROW==sqlite3_step(pStmt) ){

  190868.       const char *zName = (const char*)sqlite3_column_text(pStmt, 1);

  190869.       if( zName==0 ) break;  /* An OOM - finalize() below returns S_NOMEM */

  190870.       for(i=iOrder; i<pIter->nTblCol; i++){

  190871.         if( 0==strcmp(zName, pIter->azTblCol[i]) ) break;

  190872.       }

  190873.       if( i==pIter->nTblCol ){

  190874.         p->rc = SQLITE_ERROR;

  190875.         p->zErrmsg = sqlite3_mprintf("column missing from %q: %s",

  190876.             pIter->zDataTbl, zName

  190877.         );

  190878.       }else{

  190879.         int iPk = sqlite3_column_int(pStmt, 5);

  190880.         int bNotNull = sqlite3_column_int(pStmt, 3);

  190881.         const char *zType = (const char*)sqlite3_column_text(pStmt, 2);

  190882. 

  190883.         if( i!=iOrder ){

  190884.           SWAP(int, pIter->aiSrcOrder[i], pIter->aiSrcOrder[iOrder]);

  190885.           SWAP(char*, pIter->azTblCol[i], pIter->azTblCol[iOrder]);

  190886.         }

  190887. 

  190888.         pIter->azTblType[iOrder] = rbuStrndup(zType, &p->rc);

  190889.         assert( iPk>=0 );

  190890.         pIter->abTblPk[iOrder] = (u8)iPk;

  190891.         pIter->abNotNull[iOrder] = (u8)bNotNull || (iPk!=0);

  190892.         iOrder++;

  190893.       }

  190894.     }

  190895. 

  190896.     rbuFinalize(p, pStmt);

  190897.     rbuObjIterCacheIndexedCols(p, pIter);

  190898.     assert( pIter->eType!=RBU_PK_VTAB || pIter->abIndexed==0 );

  190899.     assert( pIter->eType!=RBU_PK_VTAB || pIter->nIndex==0 );

  190900.   }

  190901. 

  190902.   return p->rc;

  190903. }

  190904. 

  190905. /*

  190906. ** This function constructs and returns a pointer to a nul-terminated 

  190907. ** string containing some SQL clause or list based on one or more of the 

  190908. ** column names currently stored in the pIter->azTblCol[] array.

  190909. */

  190910. static char *rbuObjIterGetCollist(

  190911.   sqlite3rbu *p,                  /* RBU object */

  190912.   RbuObjIter *pIter               /* Object iterator for column names */

  190913. ){

  190914.   char *zList = 0;

  190915.   const char *zSep = "";

  190916.   int i;

  190917.   for(i=0; i<pIter->nTblCol; i++){

  190918.     const char *z = pIter->azTblCol[i];

  190919.     zList = rbuMPrintf(p, "%z%s\"%w\"", zList, zSep, z);

  190920.     zSep = ", ";

  190921.   }

  190922.   return zList;

  190923. }

  190924. 

  190925. /*

  190926. ** Return a comma separated list of the quoted PRIMARY KEY column names,

  190927. ** in order, for the current table. Before each column name, add the text

  190928. ** zPre. After each column name, add the zPost text. Use zSeparator as

  190929. ** the separator text (usually ", ").

  190930. */

  190931. static char *rbuObjIterGetPkList(

  190932.   sqlite3rbu *p,                  /* RBU object */

  190933.   RbuObjIter *pIter,              /* Object iterator for column names */

  190934.   const char *zPre,               /* Before each quoted column name */

  190935.   const char *zSeparator,         /* Separator to use between columns */

  190936.   const char *zPost               /* After each quoted column name */

  190937. ){

  190938.   int iPk = 1;

  190939.   char *zRet = 0;

  190940.   const char *zSep = "";

  190941.   while( 1 ){

  190942.     int i;

  190943.     for(i=0; i<pIter->nTblCol; i++){

  190944.       if( (int)pIter->abTblPk[i]==iPk ){

  190945.         const char *zCol = pIter->azTblCol[i];

  190946.         zRet = rbuMPrintf(p, "%z%s%s\"%w\"%s", zRet, zSep, zPre, zCol, zPost);

  190947.         zSep = zSeparator;

  190948.         break;

  190949.       }

  190950.     }

  190951.     if( i==pIter->nTblCol ) break;

  190952.     iPk++;

  190953.   }

  190954.   return zRet;

  190955. }

  190956. 

  190957. /*

  190958. ** This function is called as part of restarting an RBU vacuum within 

  190959. ** stage 1 of the process (while the *-oal file is being built) while

  190960. ** updating a table (not an index). The table may be a rowid table or

  190961. ** a WITHOUT ROWID table. It queries the target database to find the 

  190962. ** largest key that has already been written to the target table and

  190963. ** constructs a WHERE clause that can be used to extract the remaining

  190964. ** rows from the source table. For a rowid table, the WHERE clause

  190965. ** is of the form:

  190966. **

  190967. **     "WHERE _rowid_ > ?"

  190968. **

  190969. ** and for WITHOUT ROWID tables:

  190970. **

  190971. **     "WHERE (key1, key2) > (?, ?)"

  190972. **

  190973. ** Instead of "?" placeholders, the actual WHERE clauses created by

  190974. ** this function contain literal SQL values.

  190975. */

  190976. static char *rbuVacuumTableStart(

  190977.   sqlite3rbu *p,                  /* RBU handle */

  190978.   RbuObjIter *pIter,              /* RBU iterator object */

  190979.   int bRowid,                     /* True for a rowid table */

  190980.   const char *zWrite              /* Target table name prefix */

  190981. ){

  190982.   sqlite3_stmt *pMax = 0;

  190983.   char *zRet = 0;

  190984.   if( bRowid ){

  190985.     p->rc = prepareFreeAndCollectError(p->dbMain, &pMax, &p->zErrmsg, 

  190986.         sqlite3_mprintf(

  190987.           "SELECT max(_rowid_) FROM \"%s%w\"", zWrite, pIter->zTbl

  190988.         )

  190989.     );

  190990.     if( p->rc==SQLITE_OK && SQLITE_ROW==sqlite3_step(pMax) ){

  190991.       sqlite3_int64 iMax = sqlite3_column_int64(pMax, 0);

  190992.       zRet = rbuMPrintf(p, " WHERE _rowid_ > %lld ", iMax);

  190993.     }

  190994.     rbuFinalize(p, pMax);

  190995.   }else{

  190996.     char *zOrder = rbuObjIterGetPkList(p, pIter, "", ", ", " DESC");

  190997.     char *zSelect = rbuObjIterGetPkList(p, pIter, "quote(", "||','||", ")");

  190998.     char *zList = rbuObjIterGetPkList(p, pIter, "", ", ", "");

  190999. 

  191000.     if( p->rc==SQLITE_OK ){

  191001.       p->rc = prepareFreeAndCollectError(p->dbMain, &pMax, &p->zErrmsg, 

  191002.           sqlite3_mprintf(

  191003.             "SELECT %s FROM \"%s%w\" ORDER BY %s LIMIT 1", 

  191004.                 zSelect, zWrite, pIter->zTbl, zOrder

  191005.           )

  191006.       );

  191007.       if( p->rc==SQLITE_OK && SQLITE_ROW==sqlite3_step(pMax) ){

  191008.         const char *zVal = (const char*)sqlite3_column_text(pMax, 0);

  191009.         zRet = rbuMPrintf(p, " WHERE (%s) > (%s) ", zList, zVal);

  191010.       }

  191011.       rbuFinalize(p, pMax);

  191012.     }

  191013. 

  191014.     sqlite3_free(zOrder);

  191015.     sqlite3_free(zSelect);

  191016.     sqlite3_free(zList);

  191017.   }

  191018.   return zRet;

  191019. }

  191020. 

  191021. /*

  191022. ** This function is called as part of restating an RBU vacuum when the

  191023. ** current operation is writing content to an index. If possible, it

  191024. ** queries the target index b-tree for the largest key already written to

  191025. ** it, then composes and returns an expression that can be used in a WHERE 

  191026. ** clause to select the remaining required rows from the source table. 

  191027. ** It is only possible to return such an expression if:

  191028. **

  191029. **   * The index contains no DESC columns, and

  191030. **   * The last key written to the index before the operation was 

  191031. **     suspended does not contain any NULL values.

  191032. **

  191033. ** The expression is of the form:

  191034. **

  191035. **   (index-field1, index-field2, ...) > (?, ?, ...)

  191036. **

  191037. ** except that the "?" placeholders are replaced with literal values.

  191038. **

  191039. ** If the expression cannot be created, NULL is returned. In this case,

  191040. ** the caller has to use an OFFSET clause to extract only the required 

  191041. ** rows from the sourct table, just as it does for an RBU update operation.

  191042. */

  191043. char *rbuVacuumIndexStart(

  191044.   sqlite3rbu *p,                  /* RBU handle */

  191045.   RbuObjIter *pIter               /* RBU iterator object */

  191046. ){

  191047.   char *zOrder = 0;

  191048.   char *zLhs = 0;

  191049.   char *zSelect = 0;

  191050.   char *zVector = 0;

  191051.   char *zRet = 0;

  191052.   int bFailed = 0;

  191053.   const char *zSep = "";

  191054.   int iCol = 0;

  191055.   sqlite3_stmt *pXInfo = 0;

  191056. 

  191057.   p->rc = prepareFreeAndCollectError(p->dbMain, &pXInfo, &p->zErrmsg,

  191058.       sqlite3_mprintf("PRAGMA main.index_xinfo = %Q", pIter->zIdx)

  191059.   );

  191060.   while( p->rc==SQLITE_OK && SQLITE_ROW==sqlite3_step(pXInfo) ){

  191061.     int iCid = sqlite3_column_int(pXInfo, 1);

  191062.     const char *zCollate = (const char*)sqlite3_column_text(pXInfo, 4);

  191063.     const char *zCol;

  191064.     if( sqlite3_column_int(pXInfo, 3) ){

  191065.       bFailed = 1;

  191066.       break;

  191067.     }

  191068. 

  191069.     if( iCid<0 ){

  191070.       if( pIter->eType==RBU_PK_IPK ){

  191071.         int i;

  191072.         for(i=0; pIter->abTblPk[i]==0; i++);

  191073.         assert( i<pIter->nTblCol );

  191074.         zCol = pIter->azTblCol[i];

  191075.       }else{

  191076.         zCol = "_rowid_";

  191077.       }

  191078.     }else{

  191079.       zCol = pIter->azTblCol[iCid];

  191080.     }

  191081. 

  191082.     zLhs = rbuMPrintf(p, "%z%s \"%w\" COLLATE %Q",

  191083.         zLhs, zSep, zCol, zCollate

  191084.         );

  191085.     zOrder = rbuMPrintf(p, "%z%s \"rbu_imp_%d%w\" COLLATE %Q DESC",

  191086.         zOrder, zSep, iCol, zCol, zCollate

  191087.         );

  191088.     zSelect = rbuMPrintf(p, "%z%s quote(\"rbu_imp_%d%w\")",

  191089.         zSelect, zSep, iCol, zCol

  191090.         );

  191091.     zSep = ", ";

  191092.     iCol++;

  191093.   }

  191094.   rbuFinalize(p, pXInfo);

  191095.   if( bFailed ) goto index_start_out;

  191096. 

  191097.   if( p->rc==SQLITE_OK ){

  191098.     sqlite3_stmt *pSel = 0;

  191099. 

  191100.     p->rc = prepareFreeAndCollectError(p->dbMain, &pSel, &p->zErrmsg,

  191101.         sqlite3_mprintf("SELECT %s FROM \"rbu_imp_%w\" ORDER BY %s LIMIT 1",

  191102.           zSelect, pIter->zTbl, zOrder

  191103.         )

  191104.     );

  191105.     if( p->rc==SQLITE_OK && SQLITE_ROW==sqlite3_step(pSel) ){

  191106.       zSep = "";

  191107.       for(iCol=0; iCol<pIter->nCol; iCol++){

  191108.         const char *zQuoted = (const char*)sqlite3_column_text(pSel, iCol);

  191109.         if( zQuoted[0]=='N' ){

  191110.           bFailed = 1;

  191111.           break;

  191112.         }

  191113.         zVector = rbuMPrintf(p, "%z%s%s", zVector, zSep, zQuoted);

  191114.         zSep = ", ";

  191115.       }

  191116. 

  191117.       if( !bFailed ){

  191118.         zRet = rbuMPrintf(p, "(%s) > (%s)", zLhs, zVector);

  191119.       }

  191120.     }

  191121.     rbuFinalize(p, pSel);

  191122.   }

  191123. 

  191124.  index_start_out:

  191125.   sqlite3_free(zOrder);

  191126.   sqlite3_free(zSelect);

  191127.   sqlite3_free(zVector);

  191128.   sqlite3_free(zLhs);

  191129.   return zRet;

  191130. }

  191131. 

  191132. /*

  191133. ** This function is used to create a SELECT list (the list of SQL 

  191134. ** expressions that follows a SELECT keyword) for a SELECT statement 

  191135. ** used to read from an data_xxx or rbu_tmp_xxx table while updating the 

  191136. ** index object currently indicated by the iterator object passed as the 

  191137. ** second argument. A "PRAGMA index_xinfo = <idxname>" statement is used 

  191138. ** to obtain the required information.

  191139. **

  191140. ** If the index is of the following form:

  191141. **

  191142. **   CREATE INDEX i1 ON t1(c, b COLLATE nocase);

  191143. **

  191144. ** and "t1" is a table with an explicit INTEGER PRIMARY KEY column 

  191145. ** "ipk", the returned string is:

  191146. **

  191147. **   "`c` COLLATE 'BINARY', `b` COLLATE 'NOCASE', `ipk` COLLATE 'BINARY'"

  191148. **

  191149. ** As well as the returned string, three other malloc'd strings are 

  191150. ** returned via output parameters. As follows:

  191151. **

  191152. **   pzImposterCols: ...

  191153. **   pzImposterPk: ...

  191154. **   pzWhere: ...

  191155. */

  191156. static char *rbuObjIterGetIndexCols(

  191157.   sqlite3rbu *p,                  /* RBU object */

  191158.   RbuObjIter *pIter,              /* Object iterator for column names */

  191159.   char **pzImposterCols,          /* OUT: Columns for imposter table */

  191160.   char **pzImposterPk,            /* OUT: Imposter PK clause */

  191161.   char **pzWhere,                 /* OUT: WHERE clause */

  191162.   int *pnBind                     /* OUT: Trbul number of columns */

  191163. ){

  191164.   int rc = p->rc;                 /* Error code */

  191165.   int rc2;                        /* sqlite3_finalize() return code */

  191166.   char *zRet = 0;                 /* String to return */

  191167.   char *zImpCols = 0;             /* String to return via *pzImposterCols */

  191168.   char *zImpPK = 0;               /* String to return via *pzImposterPK */

  191169.   char *zWhere = 0;               /* String to return via *pzWhere */

  191170.   int nBind = 0;                  /* Value to return via *pnBind */

  191171.   const char *zCom = "";          /* Set to ", " later on */

  191172.   const char *zAnd = "";          /* Set to " AND " later on */

  191173.   sqlite3_stmt *pXInfo = 0;       /* PRAGMA index_xinfo = ? */

  191174. 

  191175.   if( rc==SQLITE_OK ){

  191176.     assert( p->zErrmsg==0 );

  191177.     rc = prepareFreeAndCollectError(p->dbMain, &pXInfo, &p->zErrmsg,

  191178.         sqlite3_mprintf("PRAGMA main.index_xinfo = %Q", pIter->zIdx)

  191179.     );

  191180.   }

  191181. 

  191182.   while( rc==SQLITE_OK && SQLITE_ROW==sqlite3_step(pXInfo) ){

  191183.     int iCid = sqlite3_column_int(pXInfo, 1);

  191184.     int bDesc = sqlite3_column_int(pXInfo, 3);

  191185.     const char *zCollate = (const char*)sqlite3_column_text(pXInfo, 4);

  191186.     const char *zCol;

  191187.     const char *zType;

  191188. 

  191189.     if( iCid<0 ){

  191190.       /* An integer primary key. If the table has an explicit IPK, use

  191191.       ** its name. Otherwise, use "rbu_rowid".  */

  191192.       if( pIter->eType==RBU_PK_IPK ){

  191193.         int i;

  191194.         for(i=0; pIter->abTblPk[i]==0; i++);

  191195.         assert( i<pIter->nTblCol );

  191196.         zCol = pIter->azTblCol[i];

  191197.       }else if( rbuIsVacuum(p) ){

  191198.         zCol = "_rowid_";

  191199.       }else{

  191200.         zCol = "rbu_rowid";

  191201.       }

  191202.       zType = "INTEGER";

  191203.     }else{

  191204.       zCol = pIter->azTblCol[iCid];

  191205.       zType = pIter->azTblType[iCid];

  191206.     }

  191207. 

  191208.     zRet = sqlite3_mprintf("%z%s\"%w\" COLLATE %Q", zRet, zCom, zCol, zCollate);

  191209.     if( pIter->bUnique==0 || sqlite3_column_int(pXInfo, 5) ){

  191210.       const char *zOrder = (bDesc ? " DESC" : "");

  191211.       zImpPK = sqlite3_mprintf("%z%s\"rbu_imp_%d%w\"%s", 

  191212.           zImpPK, zCom, nBind, zCol, zOrder

  191213.       );

  191214.     }

  191215.     zImpCols = sqlite3_mprintf("%z%s\"rbu_imp_%d%w\" %s COLLATE %Q", 

  191216.         zImpCols, zCom, nBind, zCol, zType, zCollate

  191217.     );

  191218.     zWhere = sqlite3_mprintf(

  191219.         "%z%s\"rbu_imp_%d%w\" IS ?", zWhere, zAnd, nBind, zCol

  191220.     );

  191221.     if( zRet==0 || zImpPK==0 || zImpCols==0 || zWhere==0 ) rc = SQLITE_NOMEM;

  191222.     zCom = ", ";

  191223.     zAnd = " AND ";

  191224.     nBind++;

  191225.   }

  191226. 

  191227.   rc2 = sqlite3_finalize(pXInfo);

  191228.   if( rc==SQLITE_OK ) rc = rc2;

  191229. 

  191230.   if( rc!=SQLITE_OK ){

  191231.     sqlite3_free(zRet);

  191232.     sqlite3_free(zImpCols);

  191233.     sqlite3_free(zImpPK);

  191234.     sqlite3_free(zWhere);

  191235.     zRet = 0;

  191236.     zImpCols = 0;

  191237.     zImpPK = 0;

  191238.     zWhere = 0;

  191239.     p->rc = rc;

  191240.   }

  191241. 

  191242.   *pzImposterCols = zImpCols;

  191243.   *pzImposterPk = zImpPK;

  191244.   *pzWhere = zWhere;

  191245.   *pnBind = nBind;

  191246.   return zRet;

  191247. }

  191248. 

  191249. /*

  191250. ** Assuming the current table columns are "a", "b" and "c", and the zObj

  191251. ** paramter is passed "old", return a string of the form:

  191252. **

  191253. **     "old.a, old.b, old.b"

  191254. **

  191255. ** With the column names escaped.

  191256. **

  191257. ** For tables with implicit rowids - RBU_PK_EXTERNAL and RBU_PK_NONE, append

  191258. ** the text ", old._rowid_" to the returned value.

  191259. */

  191260. static char *rbuObjIterGetOldlist(

  191261.   sqlite3rbu *p, 

  191262.   RbuObjIter *pIter,

  191263.   const char *zObj

  191264. ){

  191265.   char *zList = 0;

  191266.   if( p->rc==SQLITE_OK && pIter->abIndexed ){

  191267.     const char *zS = "";

  191268.     int i;

  191269.     for(i=0; i<pIter->nTblCol; i++){

  191270.       if( pIter->abIndexed[i] ){

  191271.         const char *zCol = pIter->azTblCol[i];

  191272.         zList = sqlite3_mprintf("%z%s%s.\"%w\"", zList, zS, zObj, zCol);

  191273.       }else{

  191274.         zList = sqlite3_mprintf("%z%sNULL", zList, zS);

  191275.       }

  191276.       zS = ", ";

  191277.       if( zList==0 ){

  191278.         p->rc = SQLITE_NOMEM;

  191279.         break;

  191280.       }

  191281.     }

  191282. 

  191283.     /* For a table with implicit rowids, append "old._rowid_" to the list. */

  191284.     if( pIter->eType==RBU_PK_EXTERNAL || pIter->eType==RBU_PK_NONE ){

  191285.       zList = rbuMPrintf(p, "%z, %s._rowid_", zList, zObj);

  191286.     }

  191287.   }

  191288.   return zList;

  191289. }

  191290. 

  191291. /*

  191292. ** Return an expression that can be used in a WHERE clause to match the

  191293. ** primary key of the current table. For example, if the table is:

  191294. **

  191295. **   CREATE TABLE t1(a, b, c, PRIMARY KEY(b, c));

  191296. **

  191297. ** Return the string:

  191298. **

  191299. **   "b = ?1 AND c = ?2"

  191300. */

  191301. static char *rbuObjIterGetWhere(

  191302.   sqlite3rbu *p, 

  191303.   RbuObjIter *pIter

  191304. ){

  191305.   char *zList = 0;

  191306.   if( pIter->eType==RBU_PK_VTAB || pIter->eType==RBU_PK_NONE ){

  191307.     zList = rbuMPrintf(p, "_rowid_ = ?%d", pIter->nTblCol+1);

  191308.   }else if( pIter->eType==RBU_PK_EXTERNAL ){

  191309.     const char *zSep = "";

  191310.     int i;

  191311.     for(i=0; i<pIter->nTblCol; i++){

  191312.       if( pIter->abTblPk[i] ){

  191313.         zList = rbuMPrintf(p, "%z%sc%d=?%d", zList, zSep, i, i+1);

  191314.         zSep = " AND ";

  191315.       }

  191316.     }

  191317.     zList = rbuMPrintf(p, 

  191318.         "_rowid_ = (SELECT id FROM rbu_imposter2 WHERE %z)", zList

  191319.     );

  191320. 

  191321.   }else{

  191322.     const char *zSep = "";

  191323.     int i;

  191324.     for(i=0; i<pIter->nTblCol; i++){

  191325.       if( pIter->abTblPk[i] ){

  191326.         const char *zCol = pIter->azTblCol[i];

  191327.         zList = rbuMPrintf(p, "%z%s\"%w\"=?%d", zList, zSep, zCol, i+1);

  191328.         zSep = " AND ";

  191329.       }

  191330.     }

  191331.   }

  191332.   return zList;

  191333. }

  191334. 

  191335. /*

  191336. ** The SELECT statement iterating through the keys for the current object

  191337. ** (p->objiter.pSelect) currently points to a valid row. However, there

  191338. ** is something wrong with the rbu_control value in the rbu_control value

  191339. ** stored in the (p->nCol+1)'th column. Set the error code and error message

  191340. ** of the RBU handle to something reflecting this.

  191341. */

  191342. static void rbuBadControlError(sqlite3rbu *p){

  191343.   p->rc = SQLITE_ERROR;

  191344.   p->zErrmsg = sqlite3_mprintf("invalid rbu_control value");

  191345. }

  191346. 

  191347. 

  191348. /*

  191349. ** Return a nul-terminated string containing the comma separated list of

  191350. ** assignments that should be included following the "SET" keyword of

  191351. ** an UPDATE statement used to update the table object that the iterator

  191352. ** passed as the second argument currently points to if the rbu_control

  191353. ** column of the data_xxx table entry is set to zMask.

  191354. **

  191355. ** The memory for the returned string is obtained from sqlite3_malloc().

  191356. ** It is the responsibility of the caller to eventually free it using

  191357. ** sqlite3_free(). 

  191358. **

  191359. ** If an OOM error is encountered when allocating space for the new

  191360. ** string, an error code is left in the rbu handle passed as the first

  191361. ** argument and NULL is returned. Or, if an error has already occurred

  191362. ** when this function is called, NULL is returned immediately, without

  191363. ** attempting the allocation or modifying the stored error code.

  191364. */

  191365. static char *rbuObjIterGetSetlist(

  191366.   sqlite3rbu *p,

  191367.   RbuObjIter *pIter,

  191368.   const char *zMask

  191369. ){

  191370.   char *zList = 0;

  191371.   if( p->rc==SQLITE_OK ){

  191372.     int i;

  191373. 

  191374.     if( (int)strlen(zMask)!=pIter->nTblCol ){

  191375.       rbuBadControlError(p);

  191376.     }else{

  191377.       const char *zSep = "";

  191378.       for(i=0; i<pIter->nTblCol; i++){

  191379.         char c = zMask[pIter->aiSrcOrder[i]];

  191380.         if( c=='x' ){

  191381.           zList = rbuMPrintf(p, "%z%s\"%w\"=?%d", 

  191382.               zList, zSep, pIter->azTblCol[i], i+1

  191383.           );

  191384.           zSep = ", ";

  191385.         }

  191386.         else if( c=='d' ){

  191387.           zList = rbuMPrintf(p, "%z%s\"%w\"=rbu_delta(\"%w\", ?%d)", 

  191388.               zList, zSep, pIter->azTblCol[i], pIter->azTblCol[i], i+1

  191389.           );

  191390.           zSep = ", ";

  191391.         }

  191392.         else if( c=='f' ){

  191393.           zList = rbuMPrintf(p, "%z%s\"%w\"=rbu_fossil_delta(\"%w\", ?%d)", 

  191394.               zList, zSep, pIter->azTblCol[i], pIter->azTblCol[i], i+1

  191395.           );

  191396.           zSep = ", ";

  191397.         }

  191398.       }

  191399.     }

  191400.   }

  191401.   return zList;

  191402. }

  191403. 

  191404. /*

  191405. ** Return a nul-terminated string consisting of nByte comma separated

  191406. ** "?" expressions. For example, if nByte is 3, return a pointer to

  191407. ** a buffer containing the string "?,?,?".

  191408. **

  191409. ** The memory for the returned string is obtained from sqlite3_malloc().

  191410. ** It is the responsibility of the caller to eventually free it using

  191411. ** sqlite3_free(). 

  191412. **

  191413. ** If an OOM error is encountered when allocating space for the new

  191414. ** string, an error code is left in the rbu handle passed as the first

  191415. ** argument and NULL is returned. Or, if an error has already occurred

  191416. ** when this function is called, NULL is returned immediately, without

  191417. ** attempting the allocation or modifying the stored error code.

  191418. */

  191419. static char *rbuObjIterGetBindlist(sqlite3rbu *p, int nBind){

  191420.   char *zRet = 0;

  191421.   sqlite3_int64 nByte = 2*(sqlite3_int64)nBind + 1;

  191422. 

  191423.   zRet = (char*)rbuMalloc(p, nByte);

  191424.   if( zRet ){

  191425.     int i;

  191426.     for(i=0; i<nBind; i++){

  191427.       zRet[i*2] = '?';

  191428.       zRet[i*2+1] = (i+1==nBind) ? '\0' : ',';

  191429.     }

  191430.   }

  191431.   return zRet;

  191432. }

  191433. 

  191434. /*

  191435. ** The iterator currently points to a table (not index) of type 

  191436. ** RBU_PK_WITHOUT_ROWID. This function creates the PRIMARY KEY 

  191437. ** declaration for the corresponding imposter table. For example,

  191438. ** if the iterator points to a table created as:

  191439. **

  191440. **   CREATE TABLE t1(a, b, c, PRIMARY KEY(b, a DESC)) WITHOUT ROWID

  191441. **

  191442. ** this function returns:

  191443. **

  191444. **   PRIMARY KEY("b", "a" DESC)

  191445. */

  191446. static char *rbuWithoutRowidPK(sqlite3rbu *p, RbuObjIter *pIter){

  191447.   char *z = 0;

  191448.   assert( pIter->zIdx==0 );

  191449.   if( p->rc==SQLITE_OK ){

  191450.     const char *zSep = "PRIMARY KEY(";

  191451.     sqlite3_stmt *pXList = 0;     /* PRAGMA index_list = (pIter->zTbl) */

  191452.     sqlite3_stmt *pXInfo = 0;     /* PRAGMA index_xinfo = <pk-index> */

  191453.    

  191454.     p->rc = prepareFreeAndCollectError(p->dbMain, &pXList, &p->zErrmsg,

  191455.         sqlite3_mprintf("PRAGMA main.index_list = %Q", pIter->zTbl)

  191456.     );

  191457.     while( p->rc==SQLITE_OK && SQLITE_ROW==sqlite3_step(pXList) ){

  191458.       const char *zOrig = (const char*)sqlite3_column_text(pXList,3);

  191459.       if( zOrig && strcmp(zOrig, "pk")==0 ){

  191460.         const char *zIdx = (const char*)sqlite3_column_text(pXList,1);

  191461.         if( zIdx ){

  191462.           p->rc = prepareFreeAndCollectError(p->dbMain, &pXInfo, &p->zErrmsg,

  191463.               sqlite3_mprintf("PRAGMA main.index_xinfo = %Q", zIdx)

  191464.           );

  191465.         }

  191466.         break;

  191467.       }

  191468.     }

  191469.     rbuFinalize(p, pXList);

  191470. 

  191471.     while( p->rc==SQLITE_OK && SQLITE_ROW==sqlite3_step(pXInfo) ){

  191472.       if( sqlite3_column_int(pXInfo, 5) ){

  191473.         /* int iCid = sqlite3_column_int(pXInfo, 0); */

  191474.         const char *zCol = (const char*)sqlite3_column_text(pXInfo, 2);

  191475.         const char *zDesc = sqlite3_column_int(pXInfo, 3) ? " DESC" : "";

  191476.         z = rbuMPrintf(p, "%z%s\"%w\"%s", z, zSep, zCol, zDesc);

  191477.         zSep = ", ";

  191478.       }

  191479.     }

  191480.     z = rbuMPrintf(p, "%z)", z);

  191481.     rbuFinalize(p, pXInfo);

  191482.   }

  191483.   return z;

  191484. }

  191485. 

  191486. /*

  191487. ** This function creates the second imposter table used when writing to

  191488. ** a table b-tree where the table has an external primary key. If the

  191489. ** iterator passed as the second argument does not currently point to

  191490. ** a table (not index) with an external primary key, this function is a

  191491. ** no-op. 

  191492. **

  191493. ** Assuming the iterator does point to a table with an external PK, this

  191494. ** function creates a WITHOUT ROWID imposter table named "rbu_imposter2"

  191495. ** used to access that PK index. For example, if the target table is

  191496. ** declared as follows:

  191497. **

  191498. **   CREATE TABLE t1(a, b TEXT, c REAL, PRIMARY KEY(b, c));

  191499. **

  191500. ** then the imposter table schema is:

  191501. **

  191502. **   CREATE TABLE rbu_imposter2(c1 TEXT, c2 REAL, id INTEGER) WITHOUT ROWID;

  191503. **

  191504. */

  191505. static void rbuCreateImposterTable2(sqlite3rbu *p, RbuObjIter *pIter){

  191506.   if( p->rc==SQLITE_OK && pIter->eType==RBU_PK_EXTERNAL ){

  191507.     int tnum = pIter->iPkTnum;    /* Root page of PK index */

  191508.     sqlite3_stmt *pQuery = 0;     /* SELECT name ... WHERE rootpage = $tnum */

  191509.     const char *zIdx = 0;         /* Name of PK index */

  191510.     sqlite3_stmt *pXInfo = 0;     /* PRAGMA main.index_xinfo = $zIdx */

  191511.     const char *zComma = "";

  191512.     char *zCols = 0;              /* Used to build up list of table cols */

  191513.     char *zPk = 0;                /* Used to build up table PK declaration */

  191514. 

  191515.     /* Figure out the name of the primary key index for the current table.

  191516.     ** This is needed for the argument to "PRAGMA index_xinfo". Set

  191517.     ** zIdx to point to a nul-terminated string containing this name. */

  191518.     p->rc = prepareAndCollectError(p->dbMain, &pQuery, &p->zErrmsg, 

  191519.         "SELECT name FROM sqlite_master WHERE rootpage = ?"

  191520.     );

  191521.     if( p->rc==SQLITE_OK ){

  191522.       sqlite3_bind_int(pQuery, 1, tnum);

  191523.       if( SQLITE_ROW==sqlite3_step(pQuery) ){

  191524.         zIdx = (const char*)sqlite3_column_text(pQuery, 0);

  191525.       }

  191526.     }

  191527.     if( zIdx ){

  191528.       p->rc = prepareFreeAndCollectError(p->dbMain, &pXInfo, &p->zErrmsg,

  191529.           sqlite3_mprintf("PRAGMA main.index_xinfo = %Q", zIdx)

  191530.       );

  191531.     }

  191532.     rbuFinalize(p, pQuery);

  191533. 

  191534.     while( p->rc==SQLITE_OK && SQLITE_ROW==sqlite3_step(pXInfo) ){

  191535.       int bKey = sqlite3_column_int(pXInfo, 5);

  191536.       if( bKey ){

  191537.         int iCid = sqlite3_column_int(pXInfo, 1);

  191538.         int bDesc = sqlite3_column_int(pXInfo, 3);

  191539.         const char *zCollate = (const char*)sqlite3_column_text(pXInfo, 4);

  191540.         zCols = rbuMPrintf(p, "%z%sc%d %s COLLATE %Q", zCols, zComma, 

  191541.             iCid, pIter->azTblType[iCid], zCollate

  191542.         );

  191543.         zPk = rbuMPrintf(p, "%z%sc%d%s", zPk, zComma, iCid, bDesc?" DESC":"");

  191544.         zComma = ", ";

  191545.       }

  191546.     }

  191547.     zCols = rbuMPrintf(p, "%z, id INTEGER", zCols);

  191548.     rbuFinalize(p, pXInfo);

  191549. 

  191550.     sqlite3_test_control(SQLITE_TESTCTRL_IMPOSTER, p->dbMain, "main", 1, tnum);

  191551.     rbuMPrintfExec(p, p->dbMain,

  191552.         "CREATE TABLE rbu_imposter2(%z, PRIMARY KEY(%z)) WITHOUT ROWID", 

  191553.         zCols, zPk

  191554.     );

  191555.     sqlite3_test_control(SQLITE_TESTCTRL_IMPOSTER, p->dbMain, "main", 0, 0);

  191556.   }

  191557. }

  191558. 

  191559. /*

  191560. ** If an error has already occurred when this function is called, it 

  191561. ** immediately returns zero (without doing any work). Or, if an error

  191562. ** occurs during the execution of this function, it sets the error code

  191563. ** in the sqlite3rbu object indicated by the first argument and returns

  191564. ** zero.

  191565. **

  191566. ** The iterator passed as the second argument is guaranteed to point to

  191567. ** a table (not an index) when this function is called. This function

  191568. ** attempts to create any imposter table required to write to the main

  191569. ** table b-tree of the table before returning. Non-zero is returned if

  191570. ** an imposter table are created, or zero otherwise.

  191571. **

  191572. ** An imposter table is required in all cases except RBU_PK_VTAB. Only

  191573. ** virtual tables are written to directly. The imposter table has the 

  191574. ** same schema as the actual target table (less any UNIQUE constraints). 

  191575. ** More precisely, the "same schema" means the same columns, types, 

  191576. ** collation sequences. For tables that do not have an external PRIMARY

  191577. ** KEY, it also means the same PRIMARY KEY declaration.

  191578. */

  191579. static void rbuCreateImposterTable(sqlite3rbu *p, RbuObjIter *pIter){

  191580.   if( p->rc==SQLITE_OK && pIter->eType!=RBU_PK_VTAB ){

  191581.     int tnum = pIter->iTnum;

  191582.     const char *zComma = "";

  191583.     char *zSql = 0;

  191584.     int iCol;

  191585.     sqlite3_test_control(SQLITE_TESTCTRL_IMPOSTER, p->dbMain, "main", 0, 1);

  191586. 

  191587.     for(iCol=0; p->rc==SQLITE_OK && iCol<pIter->nTblCol; iCol++){

  191588.       const char *zPk = "";

  191589.       const char *zCol = pIter->azTblCol[iCol];

  191590.       const char *zColl = 0;

  191591. 

  191592.       p->rc = sqlite3_table_column_metadata(

  191593.           p->dbMain, "main", pIter->zTbl, zCol, 0, &zColl, 0, 0, 0

  191594.       );

  191595. 

  191596.       if( pIter->eType==RBU_PK_IPK && pIter->abTblPk[iCol] ){

  191597.         /* If the target table column is an "INTEGER PRIMARY KEY", add

  191598.         ** "PRIMARY KEY" to the imposter table column declaration. */

  191599.         zPk = "PRIMARY KEY ";

  191600.       }

  191601.       zSql = rbuMPrintf(p, "%z%s\"%w\" %s %sCOLLATE %Q%s", 

  191602.           zSql, zComma, zCol, pIter->azTblType[iCol], zPk, zColl,

  191603.           (pIter->abNotNull[iCol] ? " NOT NULL" : "")

  191604.       );

  191605.       zComma = ", ";

  191606.     }

  191607. 

  191608.     if( pIter->eType==RBU_PK_WITHOUT_ROWID ){

  191609.       char *zPk = rbuWithoutRowidPK(p, pIter);

  191610.       if( zPk ){

  191611.         zSql = rbuMPrintf(p, "%z, %z", zSql, zPk);

  191612.       }

  191613.     }

  191614. 

  191615.     sqlite3_test_control(SQLITE_TESTCTRL_IMPOSTER, p->dbMain, "main", 1, tnum);

  191616.     rbuMPrintfExec(p, p->dbMain, "CREATE TABLE \"rbu_imp_%w\"(%z)%s", 

  191617.         pIter->zTbl, zSql, 

  191618.         (pIter->eType==RBU_PK_WITHOUT_ROWID ? " WITHOUT ROWID" : "")

  191619.     );

  191620.     sqlite3_test_control(SQLITE_TESTCTRL_IMPOSTER, p->dbMain, "main", 0, 0);

  191621.   }

  191622. }

  191623. 

  191624. /*

  191625. ** Prepare a statement used to insert rows into the "rbu_tmp_xxx" table.

  191626. ** Specifically a statement of the form:

  191627. **

  191628. **     INSERT INTO rbu_tmp_xxx VALUES(?, ?, ? ...);

  191629. **

  191630. ** The number of bound variables is equal to the number of columns in

  191631. ** the target table, plus one (for the rbu_control column), plus one more 

  191632. ** (for the rbu_rowid column) if the target table is an implicit IPK or 

  191633. ** virtual table.

  191634. */

  191635. static void rbuObjIterPrepareTmpInsert(

  191636.   sqlite3rbu *p, 

  191637.   RbuObjIter *pIter,

  191638.   const char *zCollist,

  191639.   const char *zRbuRowid

  191640. ){

  191641.   int bRbuRowid = (pIter->eType==RBU_PK_EXTERNAL || pIter->eType==RBU_PK_NONE);

  191642.   char *zBind = rbuObjIterGetBindlist(p, pIter->nTblCol + 1 + bRbuRowid);

  191643.   if( zBind ){

  191644.     assert( pIter->pTmpInsert==0 );

  191645.     p->rc = prepareFreeAndCollectError(

  191646.         p->dbRbu, &pIter->pTmpInsert, &p->zErrmsg, sqlite3_mprintf(

  191647.           "INSERT INTO %s.'rbu_tmp_%q'(rbu_control,%s%s) VALUES(%z)", 

  191648.           p->zStateDb, pIter->zDataTbl, zCollist, zRbuRowid, zBind

  191649.     ));

  191650.   }

  191651. }

  191652. 

  191653. static void rbuTmpInsertFunc(

  191654.   sqlite3_context *pCtx, 

  191655.   int nVal,

  191656.   sqlite3_value **apVal

  191657. ){

  191658.   sqlite3rbu *p = sqlite3_user_data(pCtx);

  191659.   int rc = SQLITE_OK;

  191660.   int i;

  191661. 

  191662.   assert( sqlite3_value_int(apVal[0])!=0

  191663.       || p->objiter.eType==RBU_PK_EXTERNAL 

  191664.       || p->objiter.eType==RBU_PK_NONE 

  191665.   );

  191666.   if( sqlite3_value_int(apVal[0])!=0 ){

  191667.     p->nPhaseOneStep += p->objiter.nIndex;

  191668.   }

  191669. 

  191670.   for(i=0; rc==SQLITE_OK && i<nVal; i++){

  191671.     rc = sqlite3_bind_value(p->objiter.pTmpInsert, i+1, apVal[i]);

  191672.   }

  191673.   if( rc==SQLITE_OK ){

  191674.     sqlite3_step(p->objiter.pTmpInsert);

  191675.     rc = sqlite3_reset(p->objiter.pTmpInsert);

  191676.   }

  191677. 

  191678.   if( rc!=SQLITE_OK ){

  191679.     sqlite3_result_error_code(pCtx, rc);

  191680.   }

  191681. }

  191682. 

  191683. static char *rbuObjIterGetIndexWhere(sqlite3rbu *p, RbuObjIter *pIter){

  191684.   sqlite3_stmt *pStmt = 0;

  191685.   int rc = p->rc;

  191686.   char *zRet = 0;

  191687. 

  191688.   if( rc==SQLITE_OK ){

  191689.     rc = prepareAndCollectError(p->dbMain, &pStmt, &p->zErrmsg,

  191690.         "SELECT trim(sql) FROM sqlite_master WHERE type='index' AND name=?"

  191691.     );

  191692.   }

  191693.   if( rc==SQLITE_OK ){

  191694.     int rc2;

  191695.     rc = sqlite3_bind_text(pStmt, 1, pIter->zIdx, -1, SQLITE_STATIC);

  191696.     if( rc==SQLITE_OK && SQLITE_ROW==sqlite3_step(pStmt) ){

  191697.       const char *zSql = (const char*)sqlite3_column_text(pStmt, 0);

  191698.       if( zSql ){

  191699.         int nParen = 0;           /* Number of open parenthesis */

  191700.         int i;

  191701.         for(i=0; zSql[i]; i++){

  191702.           char c = zSql[i];

  191703.           if( c=='(' ){

  191704.             nParen++;

  191705.           }

  191706.           else if( c==')' ){

  191707.             nParen--;

  191708.             if( nParen==0 ){

  191709.               i++;

  191710.               break;

  191711.             }

  191712.           }else if( c=='"' || c=='\'' || c=='`' ){

  191713.             for(i++; 1; i++){

  191714.               if( zSql[i]==c ){

  191715.                 if( zSql[i+1]!=c ) break;

  191716.                 i++;

  191717.               }

  191718.             }

  191719.           }else if( c=='[' ){

  191720.             for(i++; 1; i++){

  191721.               if( zSql[i]==']' ) break;

  191722.             }

  191723.           }

  191724.         }

  191725.         if( zSql[i] ){

  191726.           zRet = rbuStrndup(&zSql[i], &rc);

  191727.         }

  191728.       }

  191729.     }

  191730. 

  191731.     rc2 = sqlite3_finalize(pStmt);

  191732.     if( rc==SQLITE_OK ) rc = rc2;

  191733.   }

  191734. 

  191735.   p->rc = rc;

  191736.   return zRet;

  191737. }

  191738. 

  191739. /*

  191740. ** Ensure that the SQLite statement handles required to update the 

  191741. ** target database object currently indicated by the iterator passed 

  191742. ** as the second argument are available.

  191743. */

  191744. static int rbuObjIterPrepareAll(

  191745.   sqlite3rbu *p, 

  191746.   RbuObjIter *pIter,

  191747.   int nOffset                     /* Add "LIMIT -1 OFFSET $nOffset" to SELECT */

  191748. ){

  191749.   assert( pIter->bCleanup==0 );

  191750.   if( pIter->pSelect==0 && rbuObjIterCacheTableInfo(p, pIter)==SQLITE_OK ){

  191751.     const int tnum = pIter->iTnum;

  191752.     char *zCollist = 0;           /* List of indexed columns */

  191753.     char **pz = &p->zErrmsg;

  191754.     const char *zIdx = pIter->zIdx;

  191755.     char *zLimit = 0;

  191756. 

  191757.     if( nOffset ){

  191758.       zLimit = sqlite3_mprintf(" LIMIT -1 OFFSET %d", nOffset);

  191759.       if( !zLimit ) p->rc = SQLITE_NOMEM;

  191760.     }

  191761. 

  191762.     if( zIdx ){

  191763.       const char *zTbl = pIter->zTbl;

  191764.       char *zImposterCols = 0;    /* Columns for imposter table */

  191765.       char *zImposterPK = 0;      /* Primary key declaration for imposter */

  191766.       char *zWhere = 0;           /* WHERE clause on PK columns */

  191767.       char *zBind = 0;

  191768.       char *zPart = 0;

  191769.       int nBind = 0;

  191770. 

  191771.       assert( pIter->eType!=RBU_PK_VTAB );

  191772.       zCollist = rbuObjIterGetIndexCols(

  191773.           p, pIter, &zImposterCols, &zImposterPK, &zWhere, &nBind

  191774.       );

  191775.       zBind = rbuObjIterGetBindlist(p, nBind);

  191776.       zPart = rbuObjIterGetIndexWhere(p, pIter);

  191777. 

  191778.       /* Create the imposter table used to write to this index. */

  191779.       sqlite3_test_control(SQLITE_TESTCTRL_IMPOSTER, p->dbMain, "main", 0, 1);

  191780.       sqlite3_test_control(SQLITE_TESTCTRL_IMPOSTER, p->dbMain, "main", 1,tnum);

  191781.       rbuMPrintfExec(p, p->dbMain,

  191782.           "CREATE TABLE \"rbu_imp_%w\"( %s, PRIMARY KEY( %s ) ) WITHOUT ROWID",

  191783.           zTbl, zImposterCols, zImposterPK

  191784.       );

  191785.       sqlite3_test_control(SQLITE_TESTCTRL_IMPOSTER, p->dbMain, "main", 0, 0);

  191786. 

  191787.       /* Create the statement to insert index entries */

  191788.       pIter->nCol = nBind;

  191789.       if( p->rc==SQLITE_OK ){

  191790.         p->rc = prepareFreeAndCollectError(

  191791.             p->dbMain, &pIter->pInsert, &p->zErrmsg,

  191792.           sqlite3_mprintf("INSERT INTO \"rbu_imp_%w\" VALUES(%s)", zTbl, zBind)

  191793.         );

  191794.       }

  191795. 

  191796.       /* And to delete index entries */

  191797.       if( rbuIsVacuum(p)==0 && p->rc==SQLITE_OK ){

  191798.         p->rc = prepareFreeAndCollectError(

  191799.             p->dbMain, &pIter->pDelete, &p->zErrmsg,

  191800.           sqlite3_mprintf("DELETE FROM \"rbu_imp_%w\" WHERE %s", zTbl, zWhere)

  191801.         );

  191802.       }

  191803. 

  191804.       /* Create the SELECT statement to read keys in sorted order */

  191805.       if( p->rc==SQLITE_OK ){

  191806.         char *zSql;

  191807.         if( rbuIsVacuum(p) ){

  191808.           char *zStart = 0;

  191809.           if( nOffset ){

  191810.             zStart = rbuVacuumIndexStart(p, pIter);

  191811.             if( zStart ){

  191812.               sqlite3_free(zLimit);

  191813.               zLimit = 0;

  191814.             }

  191815.           }

  191816. 

  191817.           zSql = sqlite3_mprintf(

  191818.               "SELECT %s, 0 AS rbu_control FROM '%q' %s %s %s ORDER BY %s%s",

  191819.               zCollist, 

  191820.               pIter->zDataTbl,

  191821.               zPart, 

  191822.               (zStart ? (zPart ? "AND" : "WHERE") : ""), zStart,

  191823.               zCollist, zLimit

  191824.           );

  191825.           sqlite3_free(zStart);

  191826.         }else

  191827. 

  191828.         if( pIter->eType==RBU_PK_EXTERNAL || pIter->eType==RBU_PK_NONE ){

  191829.           zSql = sqlite3_mprintf(

  191830.               "SELECT %s, rbu_control FROM %s.'rbu_tmp_%q' %s ORDER BY %s%s",

  191831.               zCollist, p->zStateDb, pIter->zDataTbl,

  191832.               zPart, zCollist, zLimit

  191833.           );

  191834.         }else{

  191835.           zSql = sqlite3_mprintf(

  191836.               "SELECT %s, rbu_control FROM %s.'rbu_tmp_%q' %s "

  191837.               "UNION ALL "

  191838.               "SELECT %s, rbu_control FROM '%q' "

  191839.               "%s %s typeof(rbu_control)='integer' AND rbu_control!=1 "

  191840.               "ORDER BY %s%s",

  191841.               zCollist, p->zStateDb, pIter->zDataTbl, zPart,

  191842.               zCollist, pIter->zDataTbl, 

  191843.               zPart,

  191844.               (zPart ? "AND" : "WHERE"),

  191845.               zCollist, zLimit

  191846.           );

  191847.         }

  191848.         if( p->rc==SQLITE_OK ){

  191849.           p->rc = prepareFreeAndCollectError(p->dbRbu,&pIter->pSelect,pz,zSql);

  191850.         }else{

  191851.           sqlite3_free(zSql);

  191852.         }

  191853.       }

  191854. 

  191855.       sqlite3_free(zImposterCols);

  191856.       sqlite3_free(zImposterPK);

  191857.       sqlite3_free(zWhere);

  191858.       sqlite3_free(zBind);

  191859.       sqlite3_free(zPart);

  191860.     }else{

  191861.       int bRbuRowid = (pIter->eType==RBU_PK_VTAB)

  191862.                     ||(pIter->eType==RBU_PK_NONE)

  191863.                     ||(pIter->eType==RBU_PK_EXTERNAL && rbuIsVacuum(p));

  191864.       const char *zTbl = pIter->zTbl;       /* Table this step applies to */

  191865.       const char *zWrite;                   /* Imposter table name */

  191866. 

  191867.       char *zBindings = rbuObjIterGetBindlist(p, pIter->nTblCol + bRbuRowid);

  191868.       char *zWhere = rbuObjIterGetWhere(p, pIter);

  191869.       char *zOldlist = rbuObjIterGetOldlist(p, pIter, "old");

  191870.       char *zNewlist = rbuObjIterGetOldlist(p, pIter, "new");

  191871. 

  191872.       zCollist = rbuObjIterGetCollist(p, pIter);

  191873.       pIter->nCol = pIter->nTblCol;

  191874. 

  191875.       /* Create the imposter table or tables (if required). */

  191876.       rbuCreateImposterTable(p, pIter);

  191877.       rbuCreateImposterTable2(p, pIter);

  191878.       zWrite = (pIter->eType==RBU_PK_VTAB ? "" : "rbu_imp_");

  191879. 

  191880.       /* Create the INSERT statement to write to the target PK b-tree */

  191881.       if( p->rc==SQLITE_OK ){

  191882.         p->rc = prepareFreeAndCollectError(p->dbMain, &pIter->pInsert, pz,

  191883.             sqlite3_mprintf(

  191884.               "INSERT INTO \"%s%w\"(%s%s) VALUES(%s)", 

  191885.               zWrite, zTbl, zCollist, (bRbuRowid ? ", _rowid_" : ""), zBindings

  191886.             )

  191887.         );

  191888.       }

  191889. 

  191890.       /* Create the DELETE statement to write to the target PK b-tree.

  191891.       ** Because it only performs INSERT operations, this is not required for

  191892.       ** an rbu vacuum handle.  */

  191893.       if( rbuIsVacuum(p)==0 && p->rc==SQLITE_OK ){

  191894.         p->rc = prepareFreeAndCollectError(p->dbMain, &pIter->pDelete, pz,

  191895.             sqlite3_mprintf(

  191896.               "DELETE FROM \"%s%w\" WHERE %s", zWrite, zTbl, zWhere

  191897.             )

  191898.         );

  191899.       }

  191900. 

  191901.       if( rbuIsVacuum(p)==0 && pIter->abIndexed ){

  191902.         const char *zRbuRowid = "";

  191903.         if( pIter->eType==RBU_PK_EXTERNAL || pIter->eType==RBU_PK_NONE ){

  191904.           zRbuRowid = ", rbu_rowid";

  191905.         }

  191906. 

  191907.         /* Create the rbu_tmp_xxx table and the triggers to populate it. */

  191908.         rbuMPrintfExec(p, p->dbRbu,

  191909.             "CREATE TABLE IF NOT EXISTS %s.'rbu_tmp_%q' AS "

  191910.             "SELECT *%s FROM '%q' WHERE 0;"

  191911.             , p->zStateDb, pIter->zDataTbl

  191912.             , (pIter->eType==RBU_PK_EXTERNAL ? ", 0 AS rbu_rowid" : "")

  191913.             , pIter->zDataTbl

  191914.         );

  191915. 

  191916.         rbuMPrintfExec(p, p->dbMain,

  191917.             "CREATE TEMP TRIGGER rbu_delete_tr BEFORE DELETE ON \"%s%w\" "

  191918.             "BEGIN "

  191919.             "  SELECT rbu_tmp_insert(3, %s);"

  191920.             "END;"

  191921. 

  191922.             "CREATE TEMP TRIGGER rbu_update1_tr BEFORE UPDATE ON \"%s%w\" "

  191923.             "BEGIN "

  191924.             "  SELECT rbu_tmp_insert(3, %s);"

  191925.             "END;"

  191926. 

  191927.             "CREATE TEMP TRIGGER rbu_update2_tr AFTER UPDATE ON \"%s%w\" "

  191928.             "BEGIN "

  191929.             "  SELECT rbu_tmp_insert(4, %s);"

  191930.             "END;",

  191931.             zWrite, zTbl, zOldlist,

  191932.             zWrite, zTbl, zOldlist,

  191933.             zWrite, zTbl, zNewlist

  191934.         );

  191935. 

  191936.         if( pIter->eType==RBU_PK_EXTERNAL || pIter->eType==RBU_PK_NONE ){

  191937.           rbuMPrintfExec(p, p->dbMain,

  191938.               "CREATE TEMP TRIGGER rbu_insert_tr AFTER INSERT ON \"%s%w\" "

  191939.               "BEGIN "

  191940.               "  SELECT rbu_tmp_insert(0, %s);"

  191941.               "END;",

  191942.               zWrite, zTbl, zNewlist

  191943.           );

  191944.         }

  191945. 

  191946.         rbuObjIterPrepareTmpInsert(p, pIter, zCollist, zRbuRowid);

  191947.       }

  191948. 

  191949.       /* Create the SELECT statement to read keys from data_xxx */

  191950.       if( p->rc==SQLITE_OK ){

  191951.         const char *zRbuRowid = "";

  191952.         char *zStart = 0;

  191953.         char *zOrder = 0;

  191954.         if( bRbuRowid ){

  191955.           zRbuRowid = rbuIsVacuum(p) ? ",_rowid_ " : ",rbu_rowid";

  191956.         }

  191957. 

  191958.         if( rbuIsVacuum(p) ){

  191959.           if( nOffset ){

  191960.             zStart = rbuVacuumTableStart(p, pIter, bRbuRowid, zWrite);

  191961.             if( zStart ){

  191962.               sqlite3_free(zLimit);

  191963.               zLimit = 0;

  191964.             }

  191965.           }

  191966.           if( bRbuRowid ){

  191967.             zOrder = rbuMPrintf(p, "_rowid_");

  191968.           }else{

  191969.             zOrder = rbuObjIterGetPkList(p, pIter, "", ", ", "");

  191970.           }

  191971.         }

  191972. 

  191973.         if( p->rc==SQLITE_OK ){

  191974.           p->rc = prepareFreeAndCollectError(p->dbRbu, &pIter->pSelect, pz,

  191975.               sqlite3_mprintf(

  191976.                 "SELECT %s,%s rbu_control%s FROM '%q'%s %s %s %s",

  191977.                 zCollist, 

  191978.                 (rbuIsVacuum(p) ? "0 AS " : ""),

  191979.                 zRbuRowid,

  191980.                 pIter->zDataTbl, (zStart ? zStart : ""), 

  191981.                 (zOrder ? "ORDER BY" : ""), zOrder,

  191982.                 zLimit

  191983.               )

  191984.           );

  191985.         }

  191986.         sqlite3_free(zStart);

  191987.         sqlite3_free(zOrder);

  191988.       }

  191989. 

  191990.       sqlite3_free(zWhere);

  191991.       sqlite3_free(zOldlist);

  191992.       sqlite3_free(zNewlist);

  191993.       sqlite3_free(zBindings);

  191994.     }

  191995.     sqlite3_free(zCollist);

  191996.     sqlite3_free(zLimit);

  191997.   }

  191998.   

  191999.   return p->rc;

  192000. }

  192001. 

  192002. /*

  192003. ** Set output variable *ppStmt to point to an UPDATE statement that may

  192004. ** be used to update the imposter table for the main table b-tree of the

  192005. ** table object that pIter currently points to, assuming that the 

  192006. ** rbu_control column of the data_xyz table contains zMask.

  192007. ** 

  192008. ** If the zMask string does not specify any columns to update, then this

  192009. ** is not an error. Output variable *ppStmt is set to NULL in this case.

  192010. */

  192011. static int rbuGetUpdateStmt(

  192012.   sqlite3rbu *p,                  /* RBU handle */

  192013.   RbuObjIter *pIter,              /* Object iterator */

  192014.   const char *zMask,              /* rbu_control value ('x.x.') */

  192015.   sqlite3_stmt **ppStmt           /* OUT: UPDATE statement handle */

  192016. ){

  192017.   RbuUpdateStmt **pp;

  192018.   RbuUpdateStmt *pUp = 0;

  192019.   int nUp = 0;

  192020. 

  192021.   /* In case an error occurs */

  192022.   *ppStmt = 0;

  192023. 

  192024.   /* Search for an existing statement. If one is found, shift it to the front

  192025.   ** of the LRU queue and return immediately. Otherwise, leave nUp pointing

  192026.   ** to the number of statements currently in the cache and pUp to the

  192027.   ** last object in the list.  */

  192028.   for(pp=&pIter->pRbuUpdate; *pp; pp=&((*pp)->pNext)){

  192029.     pUp = *pp;

  192030.     if( strcmp(pUp->zMask, zMask)==0 ){

  192031.       *pp = pUp->pNext;

  192032.       pUp->pNext = pIter->pRbuUpdate;

  192033.       pIter->pRbuUpdate = pUp;

  192034.       *ppStmt = pUp->pUpdate; 

  192035.       return SQLITE_OK;

  192036.     }

  192037.     nUp++;

  192038.   }

  192039.   assert( pUp==0 || pUp->pNext==0 );

  192040. 

  192041.   if( nUp>=SQLITE_RBU_UPDATE_CACHESIZE ){

  192042.     for(pp=&pIter->pRbuUpdate; *pp!=pUp; pp=&((*pp)->pNext));

  192043.     *pp = 0;

  192044.     sqlite3_finalize(pUp->pUpdate);

  192045.     pUp->pUpdate = 0;

  192046.   }else{

  192047.     pUp = (RbuUpdateStmt*)rbuMalloc(p, sizeof(RbuUpdateStmt)+pIter->nTblCol+1);

  192048.   }

  192049. 

  192050.   if( pUp ){

  192051.     char *zWhere = rbuObjIterGetWhere(p, pIter);

  192052.     char *zSet = rbuObjIterGetSetlist(p, pIter, zMask);

  192053.     char *zUpdate = 0;

  192054. 

  192055.     pUp->zMask = (char*)&pUp[1];

  192056.     memcpy(pUp->zMask, zMask, pIter->nTblCol);

  192057.     pUp->pNext = pIter->pRbuUpdate;

  192058.     pIter->pRbuUpdate = pUp;

  192059. 

  192060.     if( zSet ){

  192061.       const char *zPrefix = "";

  192062. 

  192063.       if( pIter->eType!=RBU_PK_VTAB ) zPrefix = "rbu_imp_";

  192064.       zUpdate = sqlite3_mprintf("UPDATE \"%s%w\" SET %s WHERE %s", 

  192065.           zPrefix, pIter->zTbl, zSet, zWhere

  192066.       );

  192067.       p->rc = prepareFreeAndCollectError(

  192068.           p->dbMain, &pUp->pUpdate, &p->zErrmsg, zUpdate

  192069.       );

  192070.       *ppStmt = pUp->pUpdate;

  192071.     }

  192072.     sqlite3_free(zWhere);

  192073.     sqlite3_free(zSet);

  192074.   }

  192075. 

  192076.   return p->rc;

  192077. }

  192078. 

  192079. static sqlite3 *rbuOpenDbhandle(

  192080.   sqlite3rbu *p, 

  192081.   const char *zName, 

  192082.   int bUseVfs

  192083. ){

  192084.   sqlite3 *db = 0;

  192085.   if( p->rc==SQLITE_OK ){

  192086.     const int flags = SQLITE_OPEN_READWRITE|SQLITE_OPEN_CREATE|SQLITE_OPEN_URI;

  192087.     p->rc = sqlite3_open_v2(zName, &db, flags, bUseVfs ? p->zVfsName : 0);

  192088.     if( p->rc ){

  192089.       p->zErrmsg = sqlite3_mprintf("%s", sqlite3_errmsg(db));

  192090.       sqlite3_close(db);

  192091.       db = 0;

  192092.     }

  192093.   }

  192094.   return db;

  192095. }

  192096. 

  192097. /*

  192098. ** Free an RbuState object allocated by rbuLoadState().

  192099. */

  192100. static void rbuFreeState(RbuState *p){

  192101.   if( p ){

  192102.     sqlite3_free(p->zTbl);

  192103.     sqlite3_free(p->zDataTbl);

  192104.     sqlite3_free(p->zIdx);

  192105.     sqlite3_free(p);

  192106.   }

  192107. }

  192108. 

  192109. /*

  192110. ** Allocate an RbuState object and load the contents of the rbu_state 

  192111. ** table into it. Return a pointer to the new object. It is the 

  192112. ** responsibility of the caller to eventually free the object using

  192113. ** sqlite3_free().

  192114. **

  192115. ** If an error occurs, leave an error code and message in the rbu handle

  192116. ** and return NULL.

  192117. */

  192118. static RbuState *rbuLoadState(sqlite3rbu *p){

  192119.   RbuState *pRet = 0;

  192120.   sqlite3_stmt *pStmt = 0;

  192121.   int rc;

  192122.   int rc2;

  192123. 

  192124.   pRet = (RbuState*)rbuMalloc(p, sizeof(RbuState));

  192125.   if( pRet==0 ) return 0;

  192126. 

  192127.   rc = prepareFreeAndCollectError(p->dbRbu, &pStmt, &p->zErrmsg, 

  192128.       sqlite3_mprintf("SELECT k, v FROM %s.rbu_state", p->zStateDb)

  192129.   );

  192130.   while( rc==SQLITE_OK && SQLITE_ROW==sqlite3_step(pStmt) ){

  192131.     switch( sqlite3_column_int(pStmt, 0) ){

  192132.       case RBU_STATE_STAGE:

  192133.         pRet->eStage = sqlite3_column_int(pStmt, 1);

  192134.         if( pRet->eStage!=RBU_STAGE_OAL

  192135.          && pRet->eStage!=RBU_STAGE_MOVE

  192136.          && pRet->eStage!=RBU_STAGE_CKPT

  192137.         ){

  192138.           p->rc = SQLITE_CORRUPT;

  192139.         }

  192140.         break;

  192141. 

  192142.       case RBU_STATE_TBL:

  192143.         pRet->zTbl = rbuStrndup((char*)sqlite3_column_text(pStmt, 1), &rc);

  192144.         break;

  192145. 

  192146.       case RBU_STATE_IDX:

  192147.         pRet->zIdx = rbuStrndup((char*)sqlite3_column_text(pStmt, 1), &rc);

  192148.         break;

  192149. 

  192150.       case RBU_STATE_ROW:

  192151.         pRet->nRow = sqlite3_column_int(pStmt, 1);

  192152.         break;

  192153. 

  192154.       case RBU_STATE_PROGRESS:

  192155.         pRet->nProgress = sqlite3_column_int64(pStmt, 1);

  192156.         break;

  192157. 

  192158.       case RBU_STATE_CKPT:

  192159.         pRet->iWalCksum = sqlite3_column_int64(pStmt, 1);

  192160.         break;

  192161. 

  192162.       case RBU_STATE_COOKIE:

  192163.         pRet->iCookie = (u32)sqlite3_column_int64(pStmt, 1);

  192164.         break;

  192165. 

  192166.       case RBU_STATE_OALSZ:

  192167.         pRet->iOalSz = (u32)sqlite3_column_int64(pStmt, 1);

  192168.         break;

  192169. 

  192170.       case RBU_STATE_PHASEONESTEP:

  192171.         pRet->nPhaseOneStep = sqlite3_column_int64(pStmt, 1);

  192172.         break;

  192173. 

  192174.       case RBU_STATE_DATATBL:

  192175.         pRet->zDataTbl = rbuStrndup((char*)sqlite3_column_text(pStmt, 1), &rc);

  192176.         break;

  192177. 

  192178.       default:

  192179.         rc = SQLITE_CORRUPT;

  192180.         break;

  192181.     }

  192182.   }

  192183.   rc2 = sqlite3_finalize(pStmt);

  192184.   if( rc==SQLITE_OK ) rc = rc2;

  192185. 

  192186.   p->rc = rc;

  192187.   return pRet;

  192188. }

  192189. 

  192190. 

  192191. /*

  192192. ** Open the database handle and attach the RBU database as "rbu". If an

  192193. ** error occurs, leave an error code and message in the RBU handle.

  192194. */

  192195. static void rbuOpenDatabase(sqlite3rbu *p, int *pbRetry){

  192196.   assert( p->rc || (p->dbMain==0 && p->dbRbu==0) );

  192197.   assert( p->rc || rbuIsVacuum(p) || p->zTarget!=0 );

  192198. 

  192199.   /* Open the RBU database */

  192200.   p->dbRbu = rbuOpenDbhandle(p, p->zRbu, 1);

  192201. 

  192202.   if( p->rc==SQLITE_OK && rbuIsVacuum(p) ){

  192203.     sqlite3_file_control(p->dbRbu, "main", SQLITE_FCNTL_RBUCNT, (void*)p);

  192204.     if( p->zState==0 ){

  192205.       const char *zFile = sqlite3_db_filename(p->dbRbu, "main");

  192206.       p->zState = rbuMPrintf(p, "file://%s-vacuum?modeof=%s", zFile, zFile);

  192207.     }

  192208.   }

  192209. 

  192210.   /* If using separate RBU and state databases, attach the state database to

  192211.   ** the RBU db handle now.  */

  192212.   if( p->zState ){

  192213.     rbuMPrintfExec(p, p->dbRbu, "ATTACH %Q AS stat", p->zState);

  192214.     memcpy(p->zStateDb, "stat", 4);

  192215.   }else{

  192216.     memcpy(p->zStateDb, "main", 4);

  192217.   }

  192218. 

  192219. #if 0

  192220.   if( p->rc==SQLITE_OK && rbuIsVacuum(p) ){

  192221.     p->rc = sqlite3_exec(p->dbRbu, "BEGIN", 0, 0, 0);

  192222.   }

  192223. #endif

  192224. 

  192225.   /* If it has not already been created, create the rbu_state table */

  192226.   rbuMPrintfExec(p, p->dbRbu, RBU_CREATE_STATE, p->zStateDb);

  192227. 

  192228. #if 0

  192229.   if( rbuIsVacuum(p) ){

  192230.     if( p->rc==SQLITE_OK ){

  192231.       int rc2;

  192232.       int bOk = 0;

  192233.       sqlite3_stmt *pCnt = 0;

  192234.       p->rc = prepareAndCollectError(p->dbRbu, &pCnt, &p->zErrmsg,

  192235.           "SELECT count(*) FROM stat.sqlite_master"

  192236.       );

  192237.       if( p->rc==SQLITE_OK 

  192238.        && sqlite3_step(pCnt)==SQLITE_ROW

  192239.        && 1==sqlite3_column_int(pCnt, 0)

  192240.       ){

  192241.         bOk = 1;

  192242.       }

  192243.       rc2 = sqlite3_finalize(pCnt);

  192244.       if( p->rc==SQLITE_OK ) p->rc = rc2;

  192245. 

  192246.       if( p->rc==SQLITE_OK && bOk==0 ){

  192247.         p->rc = SQLITE_ERROR;

  192248.         p->zErrmsg = sqlite3_mprintf("invalid state database");

  192249.       }

  192250.     

  192251.       if( p->rc==SQLITE_OK ){

  192252.         p->rc = sqlite3_exec(p->dbRbu, "COMMIT", 0, 0, 0);

  192253.       }

  192254.     }

  192255.   }

  192256. #endif

  192257. 

  192258.   if( p->rc==SQLITE_OK && rbuIsVacuum(p) ){

  192259.     int bOpen = 0;

  192260.     int rc;

  192261.     p->nRbu = 0;

  192262.     p->pRbuFd = 0;

  192263.     rc = sqlite3_file_control(p->dbRbu, "main", SQLITE_FCNTL_RBUCNT, (void*)p);

  192264.     if( rc!=SQLITE_NOTFOUND ) p->rc = rc;

  192265.     if( p->eStage>=RBU_STAGE_MOVE ){

  192266.       bOpen = 1;

  192267.     }else{

  192268.       RbuState *pState = rbuLoadState(p);

  192269.       if( pState ){

  192270.         bOpen = (pState->eStage>=RBU_STAGE_MOVE);

  192271.         rbuFreeState(pState);

  192272.       }

  192273.     }

  192274.     if( bOpen ) p->dbMain = rbuOpenDbhandle(p, p->zRbu, p->nRbu<=1);

  192275.   }

  192276. 

  192277.   p->eStage = 0;

  192278.   if( p->rc==SQLITE_OK && p->dbMain==0 ){

  192279.     if( !rbuIsVacuum(p) ){

  192280.       p->dbMain = rbuOpenDbhandle(p, p->zTarget, 1);

  192281.     }else if( p->pRbuFd->pWalFd ){

  192282.       if( pbRetry ){

  192283.         p->pRbuFd->bNolock = 0;

  192284.         sqlite3_close(p->dbRbu);

  192285.         sqlite3_close(p->dbMain);

  192286.         p->dbMain = 0;

  192287.         p->dbRbu = 0;

  192288.         *pbRetry = 1;

  192289.         return;

  192290.       }

  192291.       p->rc = SQLITE_ERROR;

  192292.       p->zErrmsg = sqlite3_mprintf("cannot vacuum wal mode database");

  192293.     }else{

  192294.       char *zTarget;

  192295.       char *zExtra = 0;

  192296.       if( strlen(p->zRbu)>=5 && 0==memcmp("file:", p->zRbu, 5) ){

  192297.         zExtra = &p->zRbu[5];

  192298.         while( *zExtra ){

  192299.           if( *zExtra++=='?' ) break;

  192300.         }

  192301.         if( *zExtra=='\0' ) zExtra = 0;

  192302.       }

  192303. 

  192304.       zTarget = sqlite3_mprintf("file:%s-vactmp?rbu_memory=1%s%s", 

  192305.           sqlite3_db_filename(p->dbRbu, "main"),

  192306.           (zExtra==0 ? "" : "&"), (zExtra==0 ? "" : zExtra)

  192307.       );

  192308. 

  192309.       if( zTarget==0 ){

  192310.         p->rc = SQLITE_NOMEM;

  192311.         return;

  192312.       }

  192313.       p->dbMain = rbuOpenDbhandle(p, zTarget, p->nRbu<=1);

  192314.       sqlite3_free(zTarget);

  192315.     }

  192316.   }

  192317. 

  192318.   if( p->rc==SQLITE_OK ){

  192319.     p->rc = sqlite3_create_function(p->dbMain, 

  192320.         "rbu_tmp_insert", -1, SQLITE_UTF8, (void*)p, rbuTmpInsertFunc, 0, 0

  192321.     );

  192322.   }

  192323. 

  192324.   if( p->rc==SQLITE_OK ){

  192325.     p->rc = sqlite3_create_function(p->dbMain, 

  192326.         "rbu_fossil_delta", 2, SQLITE_UTF8, 0, rbuFossilDeltaFunc, 0, 0

  192327.     );

  192328.   }

  192329. 

  192330.   if( p->rc==SQLITE_OK ){

  192331.     p->rc = sqlite3_create_function(p->dbRbu, 

  192332.         "rbu_target_name", -1, SQLITE_UTF8, (void*)p, rbuTargetNameFunc, 0, 0

  192333.     );

  192334.   }

  192335. 

  192336.   if( p->rc==SQLITE_OK ){

  192337.     p->rc = sqlite3_file_control(p->dbMain, "main", SQLITE_FCNTL_RBU, (void*)p);

  192338.   }

  192339.   rbuMPrintfExec(p, p->dbMain, "SELECT * FROM sqlite_master");

  192340. 

  192341.   /* Mark the database file just opened as an RBU target database. If 

  192342.   ** this call returns SQLITE_NOTFOUND, then the RBU vfs is not in use.

  192343.   ** This is an error.  */

  192344.   if( p->rc==SQLITE_OK ){

  192345.     p->rc = sqlite3_file_control(p->dbMain, "main", SQLITE_FCNTL_RBU, (void*)p);

  192346.   }

  192347. 

  192348.   if( p->rc==SQLITE_NOTFOUND ){

  192349.     p->rc = SQLITE_ERROR;

  192350.     p->zErrmsg = sqlite3_mprintf("rbu vfs not found");

  192351.   }

  192352. }

  192353. 

  192354. /*

  192355. ** This routine is a copy of the sqlite3FileSuffix3() routine from the core.

  192356. ** It is a no-op unless SQLITE_ENABLE_8_3_NAMES is defined.

  192357. **

  192358. ** If SQLITE_ENABLE_8_3_NAMES is set at compile-time and if the database

  192359. ** filename in zBaseFilename is a URI with the "8_3_names=1" parameter and

  192360. ** if filename in z[] has a suffix (a.k.a. "extension") that is longer than

  192361. ** three characters, then shorten the suffix on z[] to be the last three

  192362. ** characters of the original suffix.

  192363. **

  192364. ** If SQLITE_ENABLE_8_3_NAMES is set to 2 at compile-time, then always

  192365. ** do the suffix shortening regardless of URI parameter.

  192366. **

  192367. ** Examples:

  192368. **

  192369. **     test.db-journal    =>   test.nal

  192370. **     test.db-wal        =>   test.wal

  192371. **     test.db-shm        =>   test.shm

  192372. **     test.db-mj7f3319fa =>   test.9fa

  192373. */

  192374. static void rbuFileSuffix3(const char *zBase, char *z){

  192375. #ifdef SQLITE_ENABLE_8_3_NAMES

  192376. #if SQLITE_ENABLE_8_3_NAMES<2

  192377.   if( sqlite3_uri_boolean(zBase, "8_3_names", 0) )

  192378. #endif

  192379.   {

  192380.     int i, sz;

  192381.     sz = (int)strlen(z)&0xffffff;

  192382.     for(i=sz-1; i>0 && z[i]!='/' && z[i]!='.'; i--){}

  192383.     if( z[i]=='.' && sz>i+4 ) memmove(&z[i+1], &z[sz-3], 4);

  192384.   }

  192385. #endif

  192386. }

  192387. 

  192388. /*

  192389. ** Return the current wal-index header checksum for the target database 

  192390. ** as a 64-bit integer.

  192391. **

  192392. ** The checksum is store in the first page of xShmMap memory as an 8-byte 

  192393. ** blob starting at byte offset 40.

  192394. */

  192395. static i64 rbuShmChecksum(sqlite3rbu *p){

  192396.   i64 iRet = 0;

  192397.   if( p->rc==SQLITE_OK ){

  192398.     sqlite3_file *pDb = p->pTargetFd->pReal;

  192399.     u32 volatile *ptr;

  192400.     p->rc = pDb->pMethods->xShmMap(pDb, 0, 32*1024, 0, (void volatile**)&ptr);

  192401.     if( p->rc==SQLITE_OK ){

  192402.       iRet = ((i64)ptr[10] << 32) + ptr[11];

  192403.     }

  192404.   }

  192405.   return iRet;

  192406. }

  192407. 

  192408. /*

  192409. ** This function is called as part of initializing or reinitializing an

  192410. ** incremental checkpoint. 

  192411. **

  192412. ** It populates the sqlite3rbu.aFrame[] array with the set of 

  192413. ** (wal frame -> db page) copy operations required to checkpoint the 

  192414. ** current wal file, and obtains the set of shm locks required to safely 

  192415. ** perform the copy operations directly on the file-system.

  192416. **

  192417. ** If argument pState is not NULL, then the incremental checkpoint is

  192418. ** being resumed. In this case, if the checksum of the wal-index-header

  192419. ** following recovery is not the same as the checksum saved in the RbuState

  192420. ** object, then the rbu handle is set to DONE state. This occurs if some

  192421. ** other client appends a transaction to the wal file in the middle of

  192422. ** an incremental checkpoint.

  192423. */

  192424. static void rbuSetupCheckpoint(sqlite3rbu *p, RbuState *pState){

  192425. 

  192426.   /* If pState is NULL, then the wal file may not have been opened and

  192427.   ** recovered. Running a read-statement here to ensure that doing so

  192428.   ** does not interfere with the "capture" process below.  */

  192429.   if( pState==0 ){

  192430.     p->eStage = 0;

  192431.     if( p->rc==SQLITE_OK ){

  192432.       p->rc = sqlite3_exec(p->dbMain, "SELECT * FROM sqlite_master", 0, 0, 0);

  192433.     }

  192434.   }

  192435. 

  192436.   /* Assuming no error has occurred, run a "restart" checkpoint with the

  192437.   ** sqlite3rbu.eStage variable set to CAPTURE. This turns on the following

  192438.   ** special behaviour in the rbu VFS:

  192439.   **

  192440.   **   * If the exclusive shm WRITER or READ0 lock cannot be obtained,

  192441.   **     the checkpoint fails with SQLITE_BUSY (normally SQLite would

  192442.   **     proceed with running a passive checkpoint instead of failing).

  192443.   **

  192444.   **   * Attempts to read from the *-wal file or write to the database file

  192445.   **     do not perform any IO. Instead, the frame/page combinations that

  192446.   **     would be read/written are recorded in the sqlite3rbu.aFrame[]

  192447.   **     array.

  192448.   **

  192449.   **   * Calls to xShmLock(UNLOCK) to release the exclusive shm WRITER, 

  192450.   **     READ0 and CHECKPOINT locks taken as part of the checkpoint are

  192451.   **     no-ops. These locks will not be released until the connection

  192452.   **     is closed.

  192453.   **

  192454.   **   * Attempting to xSync() the database file causes an SQLITE_INTERNAL 

  192455.   **     error.

  192456.   **

  192457.   ** As a result, unless an error (i.e. OOM or SQLITE_BUSY) occurs, the

  192458.   ** checkpoint below fails with SQLITE_INTERNAL, and leaves the aFrame[]

  192459.   ** array populated with a set of (frame -> page) mappings. Because the 

  192460.   ** WRITER, CHECKPOINT and READ0 locks are still held, it is safe to copy 

  192461.   ** data from the wal file into the database file according to the 

  192462.   ** contents of aFrame[].

  192463.   */

  192464.   if( p->rc==SQLITE_OK ){

  192465.     int rc2;

  192466.     p->eStage = RBU_STAGE_CAPTURE;

  192467.     rc2 = sqlite3_exec(p->dbMain, "PRAGMA main.wal_checkpoint=restart", 0, 0,0);

  192468.     if( rc2!=SQLITE_INTERNAL ) p->rc = rc2;

  192469.   }

  192470. 

  192471.   if( p->rc==SQLITE_OK && p->nFrame>0 ){

  192472.     p->eStage = RBU_STAGE_CKPT;

  192473.     p->nStep = (pState ? pState->nRow : 0);

  192474.     p->aBuf = rbuMalloc(p, p->pgsz);

  192475.     p->iWalCksum = rbuShmChecksum(p);

  192476.   }

  192477. 

  192478.   if( p->rc==SQLITE_OK ){

  192479.     if( p->nFrame==0 || (pState && pState->iWalCksum!=p->iWalCksum) ){

  192480.       p->rc = SQLITE_DONE;

  192481.       p->eStage = RBU_STAGE_DONE;

  192482.     }else{

  192483.       int nSectorSize;

  192484.       sqlite3_file *pDb = p->pTargetFd->pReal;

  192485.       sqlite3_file *pWal = p->pTargetFd->pWalFd->pReal;

  192486.       assert( p->nPagePerSector==0 );

  192487.       nSectorSize = pDb->pMethods->xSectorSize(pDb);

  192488.       if( nSectorSize>p->pgsz ){

  192489.         p->nPagePerSector = nSectorSize / p->pgsz;

  192490.       }else{

  192491.         p->nPagePerSector = 1;

  192492.       }

  192493. 

  192494.       /* Call xSync() on the wal file. This causes SQLite to sync the 

  192495.       ** directory in which the target database and the wal file reside, in 

  192496.       ** case it has not been synced since the rename() call in 

  192497.       ** rbuMoveOalFile(). */

  192498.       p->rc = pWal->pMethods->xSync(pWal, SQLITE_SYNC_NORMAL);

  192499.     }

  192500.   }

  192501. }

  192502. 

  192503. /*

  192504. ** Called when iAmt bytes are read from offset iOff of the wal file while

  192505. ** the rbu object is in capture mode. Record the frame number of the frame

  192506. ** being read in the aFrame[] array.

  192507. */

  192508. static int rbuCaptureWalRead(sqlite3rbu *pRbu, i64 iOff, int iAmt){

  192509.   const u32 mReq = (1<<WAL_LOCK_WRITE)|(1<<WAL_LOCK_CKPT)|(1<<WAL_LOCK_READ0);

  192510.   u32 iFrame;

  192511. 

  192512.   if( pRbu->mLock!=mReq ){

  192513.     pRbu->rc = SQLITE_BUSY;

  192514.     return SQLITE_INTERNAL;

  192515.   }

  192516. 

  192517.   pRbu->pgsz = iAmt;

  192518.   if( pRbu->nFrame==pRbu->nFrameAlloc ){

  192519.     int nNew = (pRbu->nFrameAlloc ? pRbu->nFrameAlloc : 64) * 2;

  192520.     RbuFrame *aNew;

  192521.     aNew = (RbuFrame*)sqlite3_realloc64(pRbu->aFrame, nNew * sizeof(RbuFrame));

  192522.     if( aNew==0 ) return SQLITE_NOMEM;

  192523.     pRbu->aFrame = aNew;

  192524.     pRbu->nFrameAlloc = nNew;

  192525.   }

  192526. 

  192527.   iFrame = (u32)((iOff-32) / (i64)(iAmt+24)) + 1;

  192528.   if( pRbu->iMaxFrame<iFrame ) pRbu->iMaxFrame = iFrame;

  192529.   pRbu->aFrame[pRbu->nFrame].iWalFrame = iFrame;

  192530.   pRbu->aFrame[pRbu->nFrame].iDbPage = 0;

  192531.   pRbu->nFrame++;

  192532.   return SQLITE_OK;

  192533. }

  192534. 

  192535. /*

  192536. ** Called when a page of data is written to offset iOff of the database

  192537. ** file while the rbu handle is in capture mode. Record the page number 

  192538. ** of the page being written in the aFrame[] array.

  192539. */

  192540. static int rbuCaptureDbWrite(sqlite3rbu *pRbu, i64 iOff){

  192541.   pRbu->aFrame[pRbu->nFrame-1].iDbPage = (u32)(iOff / pRbu->pgsz) + 1;

  192542.   return SQLITE_OK;

  192543. }

  192544. 

  192545. /*

  192546. ** This is called as part of an incremental checkpoint operation. Copy

  192547. ** a single frame of data from the wal file into the database file, as

  192548. ** indicated by the RbuFrame object.

  192549. */

  192550. static void rbuCheckpointFrame(sqlite3rbu *p, RbuFrame *pFrame){

  192551.   sqlite3_file *pWal = p->pTargetFd->pWalFd->pReal;

  192552.   sqlite3_file *pDb = p->pTargetFd->pReal;

  192553.   i64 iOff;

  192554. 

  192555.   assert( p->rc==SQLITE_OK );

  192556.   iOff = (i64)(pFrame->iWalFrame-1) * (p->pgsz + 24) + 32 + 24;

  192557.   p->rc = pWal->pMethods->xRead(pWal, p->aBuf, p->pgsz, iOff);

  192558.   if( p->rc ) return;

  192559. 

  192560.   iOff = (i64)(pFrame->iDbPage-1) * p->pgsz;

  192561.   p->rc = pDb->pMethods->xWrite(pDb, p->aBuf, p->pgsz, iOff);

  192562. }

  192563. 

  192564. 

  192565. /*

  192566. ** Take an EXCLUSIVE lock on the database file.

  192567. */

  192568. static void rbuLockDatabase(sqlite3rbu *p){

  192569.   sqlite3_file *pReal = p->pTargetFd->pReal;

  192570.   assert( p->rc==SQLITE_OK );

  192571.   p->rc = pReal->pMethods->xLock(pReal, SQLITE_LOCK_SHARED);

  192572.   if( p->rc==SQLITE_OK ){

  192573.     p->rc = pReal->pMethods->xLock(pReal, SQLITE_LOCK_EXCLUSIVE);

  192574.   }

  192575. }

  192576. 

  192577. #if defined(_WIN32_WCE)

  192578. static LPWSTR rbuWinUtf8ToUnicode(const char *zFilename){

  192579.   int nChar;

  192580.   LPWSTR zWideFilename;

  192581. 

  192582.   nChar = MultiByteToWideChar(CP_UTF8, 0, zFilename, -1, NULL, 0);

  192583.   if( nChar==0 ){

  192584.     return 0;

  192585.   }

  192586.   zWideFilename = sqlite3_malloc64( nChar*sizeof(zWideFilename[0]) );

  192587.   if( zWideFilename==0 ){

  192588.     return 0;

  192589.   }

  192590.   memset(zWideFilename, 0, nChar*sizeof(zWideFilename[0]));

  192591.   nChar = MultiByteToWideChar(CP_UTF8, 0, zFilename, -1, zWideFilename,

  192592.                                 nChar);

  192593.   if( nChar==0 ){

  192594.     sqlite3_free(zWideFilename);

  192595.     zWideFilename = 0;

  192596.   }

  192597.   return zWideFilename;

  192598. }

  192599. #endif

  192600. 

  192601. /*

  192602. ** The RBU handle is currently in RBU_STAGE_OAL state, with a SHARED lock

  192603. ** on the database file. This proc moves the *-oal file to the *-wal path,

  192604. ** then reopens the database file (this time in vanilla, non-oal, WAL mode).

  192605. ** If an error occurs, leave an error code and error message in the rbu 

  192606. ** handle.

  192607. */

  192608. static void rbuMoveOalFile(sqlite3rbu *p){

  192609.   const char *zBase = sqlite3_db_filename(p->dbMain, "main");

  192610.   const char *zMove = zBase;

  192611.   char *zOal;

  192612.   char *zWal;

  192613. 

  192614.   if( rbuIsVacuum(p) ){

  192615.     zMove = sqlite3_db_filename(p->dbRbu, "main");

  192616.   }

  192617.   zOal = sqlite3_mprintf("%s-oal", zMove);

  192618.   zWal = sqlite3_mprintf("%s-wal", zMove);

  192619. 

  192620.   assert( p->eStage==RBU_STAGE_MOVE );

  192621.   assert( p->rc==SQLITE_OK && p->zErrmsg==0 );

  192622.   if( zWal==0 || zOal==0 ){

  192623.     p->rc = SQLITE_NOMEM;

  192624.   }else{

  192625.     /* Move the *-oal file to *-wal. At this point connection p->db is

  192626.     ** holding a SHARED lock on the target database file (because it is

  192627.     ** in WAL mode). So no other connection may be writing the db. 

  192628.     **

  192629.     ** In order to ensure that there are no database readers, an EXCLUSIVE

  192630.     ** lock is obtained here before the *-oal is moved to *-wal.

  192631.     */

  192632.     rbuLockDatabase(p);

  192633.     if( p->rc==SQLITE_OK ){

  192634.       rbuFileSuffix3(zBase, zWal);

  192635.       rbuFileSuffix3(zBase, zOal);

  192636. 

  192637.       /* Re-open the databases. */

  192638.       rbuObjIterFinalize(&p->objiter);

  192639.       sqlite3_close(p->dbRbu);

  192640.       sqlite3_close(p->dbMain);

  192641.       p->dbMain = 0;

  192642.       p->dbRbu = 0;

  192643. 

  192644. #if defined(_WIN32_WCE)

  192645.       {

  192646.         LPWSTR zWideOal;

  192647.         LPWSTR zWideWal;

  192648. 

  192649.         zWideOal = rbuWinUtf8ToUnicode(zOal);

  192650.         if( zWideOal ){

  192651.           zWideWal = rbuWinUtf8ToUnicode(zWal);

  192652.           if( zWideWal ){

  192653.             if( MoveFileW(zWideOal, zWideWal) ){

  192654.               p->rc = SQLITE_OK;

  192655.             }else{

  192656.               p->rc = SQLITE_IOERR;

  192657.             }

  192658.             sqlite3_free(zWideWal);

  192659.           }else{

  192660.             p->rc = SQLITE_IOERR_NOMEM;

  192661.           }

  192662.           sqlite3_free(zWideOal);

  192663.         }else{

  192664.           p->rc = SQLITE_IOERR_NOMEM;

  192665.         }

  192666.       }

  192667. #else

  192668.       p->rc = rename(zOal, zWal) ? SQLITE_IOERR : SQLITE_OK;

  192669. #endif

  192670. 

  192671.       if( p->rc==SQLITE_OK ){

  192672.         rbuOpenDatabase(p, 0);

  192673.         rbuSetupCheckpoint(p, 0);

  192674.       }

  192675.     }

  192676.   }

  192677. 

  192678.   sqlite3_free(zWal);

  192679.   sqlite3_free(zOal);

  192680. }

  192681. 

  192682. /*

  192683. ** The SELECT statement iterating through the keys for the current object

  192684. ** (p->objiter.pSelect) currently points to a valid row. This function

  192685. ** determines the type of operation requested by this row and returns

  192686. ** one of the following values to indicate the result:

  192687. **

  192688. **     * RBU_INSERT

  192689. **     * RBU_DELETE

  192690. **     * RBU_IDX_DELETE

  192691. **     * RBU_UPDATE

  192692. **

  192693. ** If RBU_UPDATE is returned, then output variable *pzMask is set to

  192694. ** point to the text value indicating the columns to update.

  192695. **

  192696. ** If the rbu_control field contains an invalid value, an error code and

  192697. ** message are left in the RBU handle and zero returned.

  192698. */

  192699. static int rbuStepType(sqlite3rbu *p, const char **pzMask){

  192700.   int iCol = p->objiter.nCol;     /* Index of rbu_control column */

  192701.   int res = 0;                    /* Return value */

  192702. 

  192703.   switch( sqlite3_column_type(p->objiter.pSelect, iCol) ){

  192704.     case SQLITE_INTEGER: {

  192705.       int iVal = sqlite3_column_int(p->objiter.pSelect, iCol);

  192706.       switch( iVal ){

  192707.         case 0: res = RBU_INSERT;     break;

  192708.         case 1: res = RBU_DELETE;     break;

  192709.         case 2: res = RBU_REPLACE;    break;

  192710.         case 3: res = RBU_IDX_DELETE; break;

  192711.         case 4: res = RBU_IDX_INSERT; break;

  192712.       }

  192713.       break;

  192714.     }

  192715. 

  192716.     case SQLITE_TEXT: {

  192717.       const unsigned char *z = sqlite3_column_text(p->objiter.pSelect, iCol);

  192718.       if( z==0 ){

  192719.         p->rc = SQLITE_NOMEM;

  192720.       }else{

  192721.         *pzMask = (const char*)z;

  192722.       }

  192723.       res = RBU_UPDATE;

  192724. 

  192725.       break;

  192726.     }

  192727. 

  192728.     default:

  192729.       break;

  192730.   }

  192731. 

  192732.   if( res==0 ){

  192733.     rbuBadControlError(p);

  192734.   }

  192735.   return res;

  192736. }

  192737. 

  192738. #ifdef SQLITE_DEBUG

  192739. /*

  192740. ** Assert that column iCol of statement pStmt is named zName.

  192741. */

  192742. static void assertColumnName(sqlite3_stmt *pStmt, int iCol, const char *zName){

  192743.   const char *zCol = sqlite3_column_name(pStmt, iCol);

  192744.   assert( 0==sqlite3_stricmp(zName, zCol) );

  192745. }

  192746. #else

  192747. # define assertColumnName(x,y,z)

  192748. #endif

  192749. 

  192750. /*

  192751. ** Argument eType must be one of RBU_INSERT, RBU_DELETE, RBU_IDX_INSERT or

  192752. ** RBU_IDX_DELETE. This function performs the work of a single

  192753. ** sqlite3rbu_step() call for the type of operation specified by eType.

  192754. */

  192755. static void rbuStepOneOp(sqlite3rbu *p, int eType){

  192756.   RbuObjIter *pIter = &p->objiter;

  192757.   sqlite3_value *pVal;

  192758.   sqlite3_stmt *pWriter;

  192759.   int i;

  192760. 

  192761.   assert( p->rc==SQLITE_OK );

  192762.   assert( eType!=RBU_DELETE || pIter->zIdx==0 );

  192763.   assert( eType==RBU_DELETE || eType==RBU_IDX_DELETE

  192764.        || eType==RBU_INSERT || eType==RBU_IDX_INSERT

  192765.   );

  192766. 

  192767.   /* If this is a delete, decrement nPhaseOneStep by nIndex. If the DELETE

  192768.   ** statement below does actually delete a row, nPhaseOneStep will be

  192769.   ** incremented by the same amount when SQL function rbu_tmp_insert()

  192770.   ** is invoked by the trigger.  */

  192771.   if( eType==RBU_DELETE ){

  192772.     p->nPhaseOneStep -= p->objiter.nIndex;

  192773.   }

  192774. 

  192775.   if( eType==RBU_IDX_DELETE || eType==RBU_DELETE ){

  192776.     pWriter = pIter->pDelete;

  192777.   }else{

  192778.     pWriter = pIter->pInsert;

  192779.   }

  192780. 

  192781.   for(i=0; i<pIter->nCol; i++){

  192782.     /* If this is an INSERT into a table b-tree and the table has an

  192783.     ** explicit INTEGER PRIMARY KEY, check that this is not an attempt

  192784.     ** to write a NULL into the IPK column. That is not permitted.  */

  192785.     if( eType==RBU_INSERT 

  192786.      && pIter->zIdx==0 && pIter->eType==RBU_PK_IPK && pIter->abTblPk[i] 

  192787.      && sqlite3_column_type(pIter->pSelect, i)==SQLITE_NULL

  192788.     ){

  192789.       p->rc = SQLITE_MISMATCH;

  192790.       p->zErrmsg = sqlite3_mprintf("datatype mismatch");

  192791.       return;

  192792.     }

  192793. 

  192794.     if( eType==RBU_DELETE && pIter->abTblPk[i]==0 ){

  192795.       continue;

  192796.     }

  192797. 

  192798.     pVal = sqlite3_column_value(pIter->pSelect, i);

  192799.     p->rc = sqlite3_bind_value(pWriter, i+1, pVal);

  192800.     if( p->rc ) return;

  192801.   }

  192802.   if( pIter->zIdx==0 ){

  192803.     if( pIter->eType==RBU_PK_VTAB 

  192804.      || pIter->eType==RBU_PK_NONE 

  192805.      || (pIter->eType==RBU_PK_EXTERNAL && rbuIsVacuum(p)) 

  192806.     ){

  192807.       /* For a virtual table, or a table with no primary key, the 

  192808.       ** SELECT statement is:

  192809.       **

  192810.       **   SELECT <cols>, rbu_control, rbu_rowid FROM ....

  192811.       **

  192812.       ** Hence column_value(pIter->nCol+1).

  192813.       */

  192814.       assertColumnName(pIter->pSelect, pIter->nCol+1, 

  192815.           rbuIsVacuum(p) ? "rowid" : "rbu_rowid"

  192816.       );

  192817.       pVal = sqlite3_column_value(pIter->pSelect, pIter->nCol+1);

  192818.       p->rc = sqlite3_bind_value(pWriter, pIter->nCol+1, pVal);

  192819.     }

  192820.   }

  192821.   if( p->rc==SQLITE_OK ){

  192822.     sqlite3_step(pWriter);

  192823.     p->rc = resetAndCollectError(pWriter, &p->zErrmsg);

  192824.   }

  192825. }

  192826. 

  192827. /*

  192828. ** This function does the work for an sqlite3rbu_step() call.

  192829. **

  192830. ** The object-iterator (p->objiter) currently points to a valid object,

  192831. ** and the input cursor (p->objiter.pSelect) currently points to a valid

  192832. ** input row. Perform whatever processing is required and return.

  192833. **

  192834. ** If no  error occurs, SQLITE_OK is returned. Otherwise, an error code

  192835. ** and message is left in the RBU handle and a copy of the error code

  192836. ** returned.

  192837. */

  192838. static int rbuStep(sqlite3rbu *p){

  192839.   RbuObjIter *pIter = &p->objiter;

  192840.   const char *zMask = 0;

  192841.   int eType = rbuStepType(p, &zMask);

  192842. 

  192843.   if( eType ){

  192844.     assert( eType==RBU_INSERT     || eType==RBU_DELETE

  192845.          || eType==RBU_REPLACE    || eType==RBU_IDX_DELETE

  192846.          || eType==RBU_IDX_INSERT || eType==RBU_UPDATE

  192847.     );

  192848.     assert( eType!=RBU_UPDATE || pIter->zIdx==0 );

  192849. 

  192850.     if( pIter->zIdx==0 && (eType==RBU_IDX_DELETE || eType==RBU_IDX_INSERT) ){

  192851.       rbuBadControlError(p);

  192852.     }

  192853.     else if( eType==RBU_REPLACE ){

  192854.       if( pIter->zIdx==0 ){

  192855.         p->nPhaseOneStep += p->objiter.nIndex;

  192856.         rbuStepOneOp(p, RBU_DELETE);

  192857.       }

  192858.       if( p->rc==SQLITE_OK ) rbuStepOneOp(p, RBU_INSERT);

  192859.     }

  192860.     else if( eType!=RBU_UPDATE ){

  192861.       rbuStepOneOp(p, eType);

  192862.     }

  192863.     else{

  192864.       sqlite3_value *pVal;

  192865.       sqlite3_stmt *pUpdate = 0;

  192866.       assert( eType==RBU_UPDATE );

  192867.       p->nPhaseOneStep -= p->objiter.nIndex;

  192868.       rbuGetUpdateStmt(p, pIter, zMask, &pUpdate);

  192869.       if( pUpdate ){

  192870.         int i;

  192871.         for(i=0; p->rc==SQLITE_OK && i<pIter->nCol; i++){

  192872.           char c = zMask[pIter->aiSrcOrder[i]];

  192873.           pVal = sqlite3_column_value(pIter->pSelect, i);

  192874.           if( pIter->abTblPk[i] || c!='.' ){

  192875.             p->rc = sqlite3_bind_value(pUpdate, i+1, pVal);

  192876.           }

  192877.         }

  192878.         if( p->rc==SQLITE_OK 

  192879.          && (pIter->eType==RBU_PK_VTAB || pIter->eType==RBU_PK_NONE) 

  192880.         ){

  192881.           /* Bind the rbu_rowid value to column _rowid_ */

  192882.           assertColumnName(pIter->pSelect, pIter->nCol+1, "rbu_rowid");

  192883.           pVal = sqlite3_column_value(pIter->pSelect, pIter->nCol+1);

  192884.           p->rc = sqlite3_bind_value(pUpdate, pIter->nCol+1, pVal);

  192885.         }

  192886.         if( p->rc==SQLITE_OK ){

  192887.           sqlite3_step(pUpdate);

  192888.           p->rc = resetAndCollectError(pUpdate, &p->zErrmsg);

  192889.         }

  192890.       }

  192891.     }

  192892.   }

  192893.   return p->rc;

  192894. }

  192895. 

  192896. /*

  192897. ** Increment the schema cookie of the main database opened by p->dbMain.

  192898. **

  192899. ** Or, if this is an RBU vacuum, set the schema cookie of the main db

  192900. ** opened by p->dbMain to one more than the schema cookie of the main

  192901. ** db opened by p->dbRbu.

  192902. */

  192903. static void rbuIncrSchemaCookie(sqlite3rbu *p){

  192904.   if( p->rc==SQLITE_OK ){

  192905.     sqlite3 *dbread = (rbuIsVacuum(p) ? p->dbRbu : p->dbMain);

  192906.     int iCookie = 1000000;

  192907.     sqlite3_stmt *pStmt;

  192908. 

  192909.     p->rc = prepareAndCollectError(dbread, &pStmt, &p->zErrmsg, 

  192910.         "PRAGMA schema_version"

  192911.     );

  192912.     if( p->rc==SQLITE_OK ){

  192913.       /* Coverage: it may be that this sqlite3_step() cannot fail. There

  192914.       ** is already a transaction open, so the prepared statement cannot

  192915.       ** throw an SQLITE_SCHEMA exception. The only database page the

  192916.       ** statement reads is page 1, which is guaranteed to be in the cache.

  192917.       ** And no memory allocations are required.  */

  192918.       if( SQLITE_ROW==sqlite3_step(pStmt) ){

  192919.         iCookie = sqlite3_column_int(pStmt, 0);

  192920.       }

  192921.       rbuFinalize(p, pStmt);

  192922.     }

  192923.     if( p->rc==SQLITE_OK ){

  192924.       rbuMPrintfExec(p, p->dbMain, "PRAGMA schema_version = %d", iCookie+1);

  192925.     }

  192926.   }

  192927. }

  192928. 

  192929. /*

  192930. ** Update the contents of the rbu_state table within the rbu database. The

  192931. ** value stored in the RBU_STATE_STAGE column is eStage. All other values

  192932. ** are determined by inspecting the rbu handle passed as the first argument.

  192933. */

  192934. static void rbuSaveState(sqlite3rbu *p, int eStage){

  192935.   if( p->rc==SQLITE_OK || p->rc==SQLITE_DONE ){

  192936.     sqlite3_stmt *pInsert = 0;

  192937.     rbu_file *pFd = (rbuIsVacuum(p) ? p->pRbuFd : p->pTargetFd);

  192938.     int rc;

  192939. 

  192940.     assert( p->zErrmsg==0 );

  192941.     rc = prepareFreeAndCollectError(p->dbRbu, &pInsert, &p->zErrmsg, 

  192942.         sqlite3_mprintf(

  192943.           "INSERT OR REPLACE INTO %s.rbu_state(k, v) VALUES "

  192944.           "(%d, %d), "

  192945.           "(%d, %Q), "

  192946.           "(%d, %Q), "

  192947.           "(%d, %d), "

  192948.           "(%d, %d), "

  192949.           "(%d, %lld), "

  192950.           "(%d, %lld), "

  192951.           "(%d, %lld), "

  192952.           "(%d, %lld), "

  192953.           "(%d, %Q)  ",

  192954.           p->zStateDb,

  192955.           RBU_STATE_STAGE, eStage,

  192956.           RBU_STATE_TBL, p->objiter.zTbl, 

  192957.           RBU_STATE_IDX, p->objiter.zIdx, 

  192958.           RBU_STATE_ROW, p->nStep, 

  192959.           RBU_STATE_PROGRESS, p->nProgress,

  192960.           RBU_STATE_CKPT, p->iWalCksum,

  192961.           RBU_STATE_COOKIE, (i64)pFd->iCookie,

  192962.           RBU_STATE_OALSZ, p->iOalSz,

  192963.           RBU_STATE_PHASEONESTEP, p->nPhaseOneStep,

  192964.           RBU_STATE_DATATBL, p->objiter.zDataTbl

  192965.       )

  192966.     );

  192967.     assert( pInsert==0 || rc==SQLITE_OK );

  192968. 

  192969.     if( rc==SQLITE_OK ){

  192970.       sqlite3_step(pInsert);

  192971.       rc = sqlite3_finalize(pInsert);

  192972.     }

  192973.     if( rc!=SQLITE_OK ) p->rc = rc;

  192974.   }

  192975. }

  192976. 

  192977. 

  192978. /*

  192979. ** The second argument passed to this function is the name of a PRAGMA 

  192980. ** setting - "page_size", "auto_vacuum", "user_version" or "application_id".

  192981. ** This function executes the following on sqlite3rbu.dbRbu:

  192982. **

  192983. **   "PRAGMA main.$zPragma"

  192984. **

  192985. ** where $zPragma is the string passed as the second argument, then

  192986. ** on sqlite3rbu.dbMain:

  192987. **

  192988. **   "PRAGMA main.$zPragma = $val"

  192989. **

  192990. ** where $val is the value returned by the first PRAGMA invocation.

  192991. **

  192992. ** In short, it copies the value  of the specified PRAGMA setting from

  192993. ** dbRbu to dbMain.

  192994. */

  192995. static void rbuCopyPragma(sqlite3rbu *p, const char *zPragma){

  192996.   if( p->rc==SQLITE_OK ){

  192997.     sqlite3_stmt *pPragma = 0;

  192998.     p->rc = prepareFreeAndCollectError(p->dbRbu, &pPragma, &p->zErrmsg, 

  192999.         sqlite3_mprintf("PRAGMA main.%s", zPragma)

  193000.     );

  193001.     if( p->rc==SQLITE_OK && SQLITE_ROW==sqlite3_step(pPragma) ){

  193002.       p->rc = rbuMPrintfExec(p, p->dbMain, "PRAGMA main.%s = %d",

  193003.           zPragma, sqlite3_column_int(pPragma, 0)

  193004.       );

  193005.     }

  193006.     rbuFinalize(p, pPragma);

  193007.   }

  193008. }

  193009. 

  193010. /*

  193011. ** The RBU handle passed as the only argument has just been opened and 

  193012. ** the state database is empty. If this RBU handle was opened for an

  193013. ** RBU vacuum operation, create the schema in the target db.

  193014. */

  193015. static void rbuCreateTargetSchema(sqlite3rbu *p){

  193016.   sqlite3_stmt *pSql = 0;

  193017.   sqlite3_stmt *pInsert = 0;

  193018. 

  193019.   assert( rbuIsVacuum(p) );

  193020.   p->rc = sqlite3_exec(p->dbMain, "PRAGMA writable_schema=1", 0,0, &p->zErrmsg);

  193021.   if( p->rc==SQLITE_OK ){

  193022.     p->rc = prepareAndCollectError(p->dbRbu, &pSql, &p->zErrmsg, 

  193023.       "SELECT sql FROM sqlite_master WHERE sql!='' AND rootpage!=0"

  193024.       " AND name!='sqlite_sequence' "

  193025.       " ORDER BY type DESC"

  193026.     );

  193027.   }

  193028. 

  193029.   while( p->rc==SQLITE_OK && sqlite3_step(pSql)==SQLITE_ROW ){

  193030.     const char *zSql = (const char*)sqlite3_column_text(pSql, 0);

  193031.     p->rc = sqlite3_exec(p->dbMain, zSql, 0, 0, &p->zErrmsg);

  193032.   }

  193033.   rbuFinalize(p, pSql);

  193034.   if( p->rc!=SQLITE_OK ) return;

  193035. 

  193036.   if( p->rc==SQLITE_OK ){

  193037.     p->rc = prepareAndCollectError(p->dbRbu, &pSql, &p->zErrmsg, 

  193038.         "SELECT * FROM sqlite_master WHERE rootpage=0 OR rootpage IS NULL" 

  193039.     );

  193040.   }

  193041. 

  193042.   if( p->rc==SQLITE_OK ){

  193043.     p->rc = prepareAndCollectError(p->dbMain, &pInsert, &p->zErrmsg, 

  193044.         "INSERT INTO sqlite_master VALUES(?,?,?,?,?)"

  193045.     );

  193046.   }

  193047. 

  193048.   while( p->rc==SQLITE_OK && sqlite3_step(pSql)==SQLITE_ROW ){

  193049.     int i;

  193050.     for(i=0; i<5; i++){

  193051.       sqlite3_bind_value(pInsert, i+1, sqlite3_column_value(pSql, i));

  193052.     }

  193053.     sqlite3_step(pInsert);

  193054.     p->rc = sqlite3_reset(pInsert);

  193055.   }

  193056.   if( p->rc==SQLITE_OK ){

  193057.     p->rc = sqlite3_exec(p->dbMain, "PRAGMA writable_schema=0",0,0,&p->zErrmsg);

  193058.   }

  193059. 

  193060.   rbuFinalize(p, pSql);

  193061.   rbuFinalize(p, pInsert);

  193062. }

  193063. 

  193064. /*

  193065. ** Step the RBU object.

  193066. */

  193067. SQLITE_API int sqlite3rbu_step(sqlite3rbu *p){

  193068.   if( p ){

  193069.     switch( p->eStage ){

  193070.       case RBU_STAGE_OAL: {

  193071.         RbuObjIter *pIter = &p->objiter;

  193072. 

  193073.         /* If this is an RBU vacuum operation and the state table was empty

  193074.         ** when this handle was opened, create the target database schema. */

  193075.         if( rbuIsVacuum(p) && p->nProgress==0 && p->rc==SQLITE_OK ){

  193076.           rbuCreateTargetSchema(p);

  193077.           rbuCopyPragma(p, "user_version");

  193078.           rbuCopyPragma(p, "application_id");

  193079.         }

  193080. 

  193081.         while( p->rc==SQLITE_OK && pIter->zTbl ){

  193082. 

  193083.           if( pIter->bCleanup ){

  193084.             /* Clean up the rbu_tmp_xxx table for the previous table. It 

  193085.             ** cannot be dropped as there are currently active SQL statements.

  193086.             ** But the contents can be deleted.  */

  193087.             if( rbuIsVacuum(p)==0 && pIter->abIndexed ){

  193088.               rbuMPrintfExec(p, p->dbRbu, 

  193089.                   "DELETE FROM %s.'rbu_tmp_%q'", p->zStateDb, pIter->zDataTbl

  193090.               );

  193091.             }

  193092.           }else{

  193093.             rbuObjIterPrepareAll(p, pIter, 0);

  193094. 

  193095.             /* Advance to the next row to process. */

  193096.             if( p->rc==SQLITE_OK ){

  193097.               int rc = sqlite3_step(pIter->pSelect);

  193098.               if( rc==SQLITE_ROW ){

  193099.                 p->nProgress++;

  193100.                 p->nStep++;

  193101.                 return rbuStep(p);

  193102.               }

  193103.               p->rc = sqlite3_reset(pIter->pSelect);

  193104.               p->nStep = 0;

  193105.             }

  193106.           }

  193107. 

  193108.           rbuObjIterNext(p, pIter);

  193109.         }

  193110. 

  193111.         if( p->rc==SQLITE_OK ){

  193112.           assert( pIter->zTbl==0 );

  193113.           rbuSaveState(p, RBU_STAGE_MOVE);

  193114.           rbuIncrSchemaCookie(p);

  193115.           if( p->rc==SQLITE_OK ){

  193116.             p->rc = sqlite3_exec(p->dbMain, "COMMIT", 0, 0, &p->zErrmsg);

  193117.           }

  193118.           if( p->rc==SQLITE_OK ){

  193119.             p->rc = sqlite3_exec(p->dbRbu, "COMMIT", 0, 0, &p->zErrmsg);

  193120.           }

  193121.           p->eStage = RBU_STAGE_MOVE;

  193122.         }

  193123.         break;

  193124.       }

  193125. 

  193126.       case RBU_STAGE_MOVE: {

  193127.         if( p->rc==SQLITE_OK ){

  193128.           rbuMoveOalFile(p);

  193129.           p->nProgress++;

  193130.         }

  193131.         break;

  193132.       }

  193133. 

  193134.       case RBU_STAGE_CKPT: {

  193135.         if( p->rc==SQLITE_OK ){

  193136.           if( p->nStep>=p->nFrame ){

  193137.             sqlite3_file *pDb = p->pTargetFd->pReal;

  193138.   

  193139.             /* Sync the db file */

  193140.             p->rc = pDb->pMethods->xSync(pDb, SQLITE_SYNC_NORMAL);

  193141.   

  193142.             /* Update nBackfill */

  193143.             if( p->rc==SQLITE_OK ){

  193144.               void volatile *ptr;

  193145.               p->rc = pDb->pMethods->xShmMap(pDb, 0, 32*1024, 0, &ptr);

  193146.               if( p->rc==SQLITE_OK ){

  193147.                 ((u32 volatile*)ptr)[24] = p->iMaxFrame;

  193148.               }

  193149.             }

  193150.   

  193151.             if( p->rc==SQLITE_OK ){

  193152.               p->eStage = RBU_STAGE_DONE;

  193153.               p->rc = SQLITE_DONE;

  193154.             }

  193155.           }else{

  193156.             /* At one point the following block copied a single frame from the

  193157.             ** wal file to the database file. So that one call to sqlite3rbu_step()

  193158.             ** checkpointed a single frame. 

  193159.             **

  193160.             ** However, if the sector-size is larger than the page-size, and the

  193161.             ** application calls sqlite3rbu_savestate() or close() immediately

  193162.             ** after this step, then rbu_step() again, then a power failure occurs,

  193163.             ** then the database page written here may be damaged. Work around

  193164.             ** this by checkpointing frames until the next page in the aFrame[]

  193165.             ** lies on a different disk sector to the current one. */

  193166.             u32 iSector;

  193167.             do{

  193168.               RbuFrame *pFrame = &p->aFrame[p->nStep];

  193169.               iSector = (pFrame->iDbPage-1) / p->nPagePerSector;

  193170.               rbuCheckpointFrame(p, pFrame);

  193171.               p->nStep++;

  193172.             }while( p->nStep<p->nFrame 

  193173.                  && iSector==((p->aFrame[p->nStep].iDbPage-1) / p->nPagePerSector)

  193174.                  && p->rc==SQLITE_OK

  193175.             );

  193176.           }

  193177.           p->nProgress++;

  193178.         }

  193179.         break;

  193180.       }

  193181. 

  193182.       default:

  193183.         break;

  193184.     }

  193185.     return p->rc;

  193186.   }else{

  193187.     return SQLITE_NOMEM;

  193188.   }

  193189. }

  193190. 

  193191. /*

  193192. ** Compare strings z1 and z2, returning 0 if they are identical, or non-zero

  193193. ** otherwise. Either or both argument may be NULL. Two NULL values are

  193194. ** considered equal, and NULL is considered distinct from all other values.

  193195. */

  193196. static int rbuStrCompare(const char *z1, const char *z2){

  193197.   if( z1==0 && z2==0 ) return 0;

  193198.   if( z1==0 || z2==0 ) return 1;

  193199.   return (sqlite3_stricmp(z1, z2)!=0);

  193200. }

  193201. 

  193202. /*

  193203. ** This function is called as part of sqlite3rbu_open() when initializing

  193204. ** an rbu handle in OAL stage. If the rbu update has not started (i.e.

  193205. ** the rbu_state table was empty) it is a no-op. Otherwise, it arranges

  193206. ** things so that the next call to sqlite3rbu_step() continues on from

  193207. ** where the previous rbu handle left off.

  193208. **

  193209. ** If an error occurs, an error code and error message are left in the

  193210. ** rbu handle passed as the first argument.

  193211. */

  193212. static void rbuSetupOal(sqlite3rbu *p, RbuState *pState){

  193213.   assert( p->rc==SQLITE_OK );

  193214.   if( pState->zTbl ){

  193215.     RbuObjIter *pIter = &p->objiter;

  193216.     int rc = SQLITE_OK;

  193217. 

  193218.     while( rc==SQLITE_OK && pIter->zTbl && (pIter->bCleanup 

  193219.        || rbuStrCompare(pIter->zIdx, pState->zIdx)

  193220.        || (pState->zDataTbl==0 && rbuStrCompare(pIter->zTbl, pState->zTbl))

  193221.        || (pState->zDataTbl && rbuStrCompare(pIter->zDataTbl, pState->zDataTbl))

  193222.     )){

  193223.       rc = rbuObjIterNext(p, pIter);

  193224.     }

  193225. 

  193226.     if( rc==SQLITE_OK && !pIter->zTbl ){

  193227.       rc = SQLITE_ERROR;

  193228.       p->zErrmsg = sqlite3_mprintf("rbu_state mismatch error");

  193229.     }

  193230. 

  193231.     if( rc==SQLITE_OK ){

  193232.       p->nStep = pState->nRow;

  193233.       rc = rbuObjIterPrepareAll(p, &p->objiter, p->nStep);

  193234.     }

  193235. 

  193236.     p->rc = rc;

  193237.   }

  193238. }

  193239. 

  193240. /*

  193241. ** If there is a "*-oal" file in the file-system corresponding to the

  193242. ** target database in the file-system, delete it. If an error occurs,

  193243. ** leave an error code and error message in the rbu handle.

  193244. */

  193245. static void rbuDeleteOalFile(sqlite3rbu *p){

  193246.   char *zOal = rbuMPrintf(p, "%s-oal", p->zTarget);

  193247.   if( zOal ){

  193248.     sqlite3_vfs *pVfs = sqlite3_vfs_find(0);

  193249.     assert( pVfs && p->rc==SQLITE_OK && p->zErrmsg==0 );

  193250.     pVfs->xDelete(pVfs, zOal, 0);

  193251.     sqlite3_free(zOal);

  193252.   }

  193253. }

  193254. 

  193255. /*

  193256. ** Allocate a private rbu VFS for the rbu handle passed as the only

  193257. ** argument. This VFS will be used unless the call to sqlite3rbu_open()

  193258. ** specified a URI with a vfs=? option in place of a target database

  193259. ** file name.

  193260. */

  193261. static void rbuCreateVfs(sqlite3rbu *p){

  193262.   int rnd;

  193263.   char zRnd[64];

  193264. 

  193265.   assert( p->rc==SQLITE_OK );

  193266.   sqlite3_randomness(sizeof(int), (void*)&rnd);

  193267.   sqlite3_snprintf(sizeof(zRnd), zRnd, "rbu_vfs_%d", rnd);

  193268.   p->rc = sqlite3rbu_create_vfs(zRnd, 0);

  193269.   if( p->rc==SQLITE_OK ){

  193270.     sqlite3_vfs *pVfs = sqlite3_vfs_find(zRnd);

  193271.     assert( pVfs );

  193272.     p->zVfsName = pVfs->zName;

  193273.     ((rbu_vfs*)pVfs)->pRbu = p;

  193274.   }

  193275. }

  193276. 

  193277. /*

  193278. ** Destroy the private VFS created for the rbu handle passed as the only

  193279. ** argument by an earlier call to rbuCreateVfs().

  193280. */

  193281. static void rbuDeleteVfs(sqlite3rbu *p){

  193282.   if( p->zVfsName ){

  193283.     sqlite3rbu_destroy_vfs(p->zVfsName);

  193284.     p->zVfsName = 0;

  193285.   }

  193286. }

  193287. 

  193288. /*

  193289. ** This user-defined SQL function is invoked with a single argument - the

  193290. ** name of a table expected to appear in the target database. It returns

  193291. ** the number of auxilliary indexes on the table.

  193292. */

  193293. static void rbuIndexCntFunc(

  193294.   sqlite3_context *pCtx, 

  193295.   int nVal,

  193296.   sqlite3_value **apVal

  193297. ){

  193298.   sqlite3rbu *p = (sqlite3rbu*)sqlite3_user_data(pCtx);

  193299.   sqlite3_stmt *pStmt = 0;

  193300.   char *zErrmsg = 0;

  193301.   int rc;

  193302. 

  193303.   assert( nVal==1 );

  193304.   

  193305.   rc = prepareFreeAndCollectError(p->dbMain, &pStmt, &zErrmsg, 

  193306.       sqlite3_mprintf("SELECT count(*) FROM sqlite_master "

  193307.         "WHERE type='index' AND tbl_name = %Q", sqlite3_value_text(apVal[0]))

  193308.   );

  193309.   if( rc!=SQLITE_OK ){

  193310.     sqlite3_result_error(pCtx, zErrmsg, -1);

  193311.   }else{

  193312.     int nIndex = 0;

  193313.     if( SQLITE_ROW==sqlite3_step(pStmt) ){

  193314.       nIndex = sqlite3_column_int(pStmt, 0);

  193315.     }

  193316.     rc = sqlite3_finalize(pStmt);

  193317.     if( rc==SQLITE_OK ){

  193318.       sqlite3_result_int(pCtx, nIndex);

  193319.     }else{

  193320.       sqlite3_result_error(pCtx, sqlite3_errmsg(p->dbMain), -1);

  193321.     }

  193322.   }

  193323. 

  193324.   sqlite3_free(zErrmsg);

  193325. }

  193326. 

  193327. /*

  193328. ** If the RBU database contains the rbu_count table, use it to initialize

  193329. ** the sqlite3rbu.nPhaseOneStep variable. The schema of the rbu_count table

  193330. ** is assumed to contain the same columns as:

  193331. **

  193332. **   CREATE TABLE rbu_count(tbl TEXT PRIMARY KEY, cnt INTEGER) WITHOUT ROWID;

  193333. **

  193334. ** There should be one row in the table for each data_xxx table in the

  193335. ** database. The 'tbl' column should contain the name of a data_xxx table,

  193336. ** and the cnt column the number of rows it contains.

  193337. **

  193338. ** sqlite3rbu.nPhaseOneStep is initialized to the sum of (1 + nIndex) * cnt

  193339. ** for all rows in the rbu_count table, where nIndex is the number of 

  193340. ** indexes on the corresponding target database table.

  193341. */

  193342. static void rbuInitPhaseOneSteps(sqlite3rbu *p){

  193343.   if( p->rc==SQLITE_OK ){

  193344.     sqlite3_stmt *pStmt = 0;

  193345.     int bExists = 0;                /* True if rbu_count exists */

  193346. 

  193347.     p->nPhaseOneStep = -1;

  193348. 

  193349.     p->rc = sqlite3_create_function(p->dbRbu, 

  193350.         "rbu_index_cnt", 1, SQLITE_UTF8, (void*)p, rbuIndexCntFunc, 0, 0

  193351.     );

  193352.   

  193353.     /* Check for the rbu_count table. If it does not exist, or if an error

  193354.     ** occurs, nPhaseOneStep will be left set to -1. */

  193355.     if( p->rc==SQLITE_OK ){

  193356.       p->rc = prepareAndCollectError(p->dbRbu, &pStmt, &p->zErrmsg,

  193357.           "SELECT 1 FROM sqlite_master WHERE tbl_name = 'rbu_count'"

  193358.       );

  193359.     }

  193360.     if( p->rc==SQLITE_OK ){

  193361.       if( SQLITE_ROW==sqlite3_step(pStmt) ){

  193362.         bExists = 1;

  193363.       }

  193364.       p->rc = sqlite3_finalize(pStmt);

  193365.     }

  193366.   

  193367.     if( p->rc==SQLITE_OK && bExists ){

  193368.       p->rc = prepareAndCollectError(p->dbRbu, &pStmt, &p->zErrmsg,

  193369.           "SELECT sum(cnt * (1 + rbu_index_cnt(rbu_target_name(tbl))))"

  193370.           "FROM rbu_count"

  193371.       );

  193372.       if( p->rc==SQLITE_OK ){

  193373.         if( SQLITE_ROW==sqlite3_step(pStmt) ){

  193374.           p->nPhaseOneStep = sqlite3_column_int64(pStmt, 0);

  193375.         }

  193376.         p->rc = sqlite3_finalize(pStmt);

  193377.       }

  193378.     }

  193379.   }

  193380. }

  193381. 

  193382. 

  193383. static sqlite3rbu *openRbuHandle(

  193384.   const char *zTarget, 

  193385.   const char *zRbu,

  193386.   const char *zState

  193387. ){

  193388.   sqlite3rbu *p;

  193389.   size_t nTarget = zTarget ? strlen(zTarget) : 0;

  193390.   size_t nRbu = strlen(zRbu);

  193391.   size_t nByte = sizeof(sqlite3rbu) + nTarget+1 + nRbu+1;

  193392. 

  193393.   p = (sqlite3rbu*)sqlite3_malloc64(nByte);

  193394.   if( p ){

  193395.     RbuState *pState = 0;

  193396. 

  193397.     /* Create the custom VFS. */

  193398.     memset(p, 0, sizeof(sqlite3rbu));

  193399.     rbuCreateVfs(p);

  193400. 

  193401.     /* Open the target, RBU and state databases */

  193402.     if( p->rc==SQLITE_OK ){

  193403.       char *pCsr = (char*)&p[1];

  193404.       int bRetry = 0;

  193405.       if( zTarget ){

  193406.         p->zTarget = pCsr;

  193407.         memcpy(p->zTarget, zTarget, nTarget+1);

  193408.         pCsr += nTarget+1;

  193409.       }

  193410.       p->zRbu = pCsr;

  193411.       memcpy(p->zRbu, zRbu, nRbu+1);

  193412.       pCsr += nRbu+1;

  193413.       if( zState ){

  193414.         p->zState = rbuMPrintf(p, "%s", zState);

  193415.       }

  193416. 

  193417.       /* If the first attempt to open the database file fails and the bRetry

  193418.       ** flag it set, this means that the db was not opened because it seemed

  193419.       ** to be a wal-mode db. But, this may have happened due to an earlier

  193420.       ** RBU vacuum operation leaving an old wal file in the directory.

  193421.       ** If this is the case, it will have been checkpointed and deleted

  193422.       ** when the handle was closed and a second attempt to open the 

  193423.       ** database may succeed.  */

  193424.       rbuOpenDatabase(p, &bRetry);

  193425.       if( bRetry ){

  193426.         rbuOpenDatabase(p, 0);

  193427.       }

  193428.     }

  193429. 

  193430.     if( p->rc==SQLITE_OK ){

  193431.       pState = rbuLoadState(p);

  193432.       assert( pState || p->rc!=SQLITE_OK );

  193433.       if( p->rc==SQLITE_OK ){

  193434. 

  193435.         if( pState->eStage==0 ){ 

  193436.           rbuDeleteOalFile(p);

  193437.           rbuInitPhaseOneSteps(p);

  193438.           p->eStage = RBU_STAGE_OAL;

  193439.         }else{

  193440.           p->eStage = pState->eStage;

  193441.           p->nPhaseOneStep = pState->nPhaseOneStep;

  193442.         }

  193443.         p->nProgress = pState->nProgress;

  193444.         p->iOalSz = pState->iOalSz;

  193445.       }

  193446.     }

  193447.     assert( p->rc!=SQLITE_OK || p->eStage!=0 );

  193448. 

  193449.     if( p->rc==SQLITE_OK && p->pTargetFd->pWalFd ){

  193450.       if( p->eStage==RBU_STAGE_OAL ){

  193451.         p->rc = SQLITE_ERROR;

  193452.         p->zErrmsg = sqlite3_mprintf("cannot update wal mode database");

  193453.       }else if( p->eStage==RBU_STAGE_MOVE ){

  193454.         p->eStage = RBU_STAGE_CKPT;

  193455.         p->nStep = 0;

  193456.       }

  193457.     }

  193458. 

  193459.     if( p->rc==SQLITE_OK 

  193460.      && (p->eStage==RBU_STAGE_OAL || p->eStage==RBU_STAGE_MOVE)

  193461.      && pState->eStage!=0

  193462.     ){

  193463.       rbu_file *pFd = (rbuIsVacuum(p) ? p->pRbuFd : p->pTargetFd);

  193464.       if( pFd->iCookie!=pState->iCookie ){   

  193465.         /* At this point (pTargetFd->iCookie) contains the value of the

  193466.         ** change-counter cookie (the thing that gets incremented when a 

  193467.         ** transaction is committed in rollback mode) currently stored on 

  193468.         ** page 1 of the database file. */

  193469.         p->rc = SQLITE_BUSY;

  193470.         p->zErrmsg = sqlite3_mprintf("database modified during rbu %s",

  193471.             (rbuIsVacuum(p) ? "vacuum" : "update")

  193472.         );

  193473.       }

  193474.     }

  193475. 

  193476.     if( p->rc==SQLITE_OK ){

  193477.       if( p->eStage==RBU_STAGE_OAL ){

  193478.         sqlite3 *db = p->dbMain;

  193479.         p->rc = sqlite3_exec(p->dbRbu, "BEGIN", 0, 0, &p->zErrmsg);

  193480. 

  193481.         /* Point the object iterator at the first object */

  193482.         if( p->rc==SQLITE_OK ){

  193483.           p->rc = rbuObjIterFirst(p, &p->objiter);

  193484.         }

  193485. 

  193486.         /* If the RBU database contains no data_xxx tables, declare the RBU

  193487.         ** update finished.  */

  193488.         if( p->rc==SQLITE_OK && p->objiter.zTbl==0 ){

  193489.           p->rc = SQLITE_DONE;

  193490.           p->eStage = RBU_STAGE_DONE;

  193491.         }else{

  193492.           if( p->rc==SQLITE_OK && pState->eStage==0 && rbuIsVacuum(p) ){

  193493.             rbuCopyPragma(p, "page_size");

  193494.             rbuCopyPragma(p, "auto_vacuum");

  193495.           }

  193496. 

  193497.           /* Open transactions both databases. The *-oal file is opened or

  193498.           ** created at this point. */

  193499.           if( p->rc==SQLITE_OK ){

  193500.             p->rc = sqlite3_exec(db, "BEGIN IMMEDIATE", 0, 0, &p->zErrmsg);

  193501.           }

  193502. 

  193503.           /* Check if the main database is a zipvfs db. If it is, set the upper

  193504.           ** level pager to use "journal_mode=off". This prevents it from 

  193505.           ** generating a large journal using a temp file.  */

  193506.           if( p->rc==SQLITE_OK ){

  193507.             int frc = sqlite3_file_control(db, "main", SQLITE_FCNTL_ZIPVFS, 0);

  193508.             if( frc==SQLITE_OK ){

  193509.               p->rc = sqlite3_exec(

  193510.                 db, "PRAGMA journal_mode=off",0,0,&p->zErrmsg);

  193511.             }

  193512.           }

  193513. 

  193514.           if( p->rc==SQLITE_OK ){

  193515.             rbuSetupOal(p, pState);

  193516.           }

  193517.         }

  193518.       }else if( p->eStage==RBU_STAGE_MOVE ){

  193519.         /* no-op */

  193520.       }else if( p->eStage==RBU_STAGE_CKPT ){

  193521.         rbuSetupCheckpoint(p, pState);

  193522.       }else if( p->eStage==RBU_STAGE_DONE ){

  193523.         p->rc = SQLITE_DONE;

  193524.       }else{

  193525.         p->rc = SQLITE_CORRUPT;

  193526.       }

  193527.     }

  193528. 

  193529.     rbuFreeState(pState);

  193530.   }

  193531. 

  193532.   return p;

  193533. }

  193534. 

  193535. /*

  193536. ** Allocate and return an RBU handle with all fields zeroed except for the

  193537. ** error code, which is set to SQLITE_MISUSE.

  193538. */

  193539. static sqlite3rbu *rbuMisuseError(void){

  193540.   sqlite3rbu *pRet;

  193541.   pRet = sqlite3_malloc64(sizeof(sqlite3rbu));

  193542.   if( pRet ){

  193543.     memset(pRet, 0, sizeof(sqlite3rbu));

  193544.     pRet->rc = SQLITE_MISUSE;

  193545.   }

  193546.   return pRet;

  193547. }

  193548. 

  193549. /*

  193550. ** Open and return a new RBU handle. 

  193551. */

  193552. SQLITE_API sqlite3rbu *sqlite3rbu_open(

  193553.   const char *zTarget, 

  193554.   const char *zRbu,

  193555.   const char *zState

  193556. ){

  193557.   if( zTarget==0 || zRbu==0 ){ return rbuMisuseError(); }

  193558.   /* TODO: Check that zTarget and zRbu are non-NULL */

  193559.   return openRbuHandle(zTarget, zRbu, zState);

  193560. }

  193561. 

  193562. /*

  193563. ** Open a handle to begin or resume an RBU VACUUM operation.

  193564. */

  193565. SQLITE_API sqlite3rbu *sqlite3rbu_vacuum(

  193566.   const char *zTarget, 

  193567.   const char *zState

  193568. ){

  193569.   if( zTarget==0 ){ return rbuMisuseError(); }

  193570.   if( zState ){

  193571.     int n = strlen(zState);

  193572.     if( n>=7 && 0==memcmp("-vactmp", &zState[n-7], 7) ){

  193573.       return rbuMisuseError();

  193574.     }

  193575.   }

  193576.   /* TODO: Check that both arguments are non-NULL */

  193577.   return openRbuHandle(0, zTarget, zState);

  193578. }

  193579. 

  193580. /*

  193581. ** Return the database handle used by pRbu.

  193582. */

  193583. SQLITE_API sqlite3 *sqlite3rbu_db(sqlite3rbu *pRbu, int bRbu){

  193584.   sqlite3 *db = 0;

  193585.   if( pRbu ){

  193586.     db = (bRbu ? pRbu->dbRbu : pRbu->dbMain);

  193587.   }

  193588.   return db;

  193589. }

  193590. 

  193591. 

  193592. /*

  193593. ** If the error code currently stored in the RBU handle is SQLITE_CONSTRAINT,

  193594. ** then edit any error message string so as to remove all occurrences of

  193595. ** the pattern "rbu_imp_[0-9]*".

  193596. */

  193597. static void rbuEditErrmsg(sqlite3rbu *p){

  193598.   if( p->rc==SQLITE_CONSTRAINT && p->zErrmsg ){

  193599.     unsigned int i;

  193600.     size_t nErrmsg = strlen(p->zErrmsg);

  193601.     for(i=0; i<(nErrmsg-8); i++){

  193602.       if( memcmp(&p->zErrmsg[i], "rbu_imp_", 8)==0 ){

  193603.         int nDel = 8;

  193604.         while( p->zErrmsg[i+nDel]>='0' && p->zErrmsg[i+nDel]<='9' ) nDel++;

  193605.         memmove(&p->zErrmsg[i], &p->zErrmsg[i+nDel], nErrmsg + 1 - i - nDel);

  193606.         nErrmsg -= nDel;

  193607.       }

  193608.     }

  193609.   }

  193610. }

  193611. 

  193612. /*

  193613. ** Close the RBU handle.

  193614. */

  193615. SQLITE_API int sqlite3rbu_close(sqlite3rbu *p, char **pzErrmsg){

  193616.   int rc;

  193617.   if( p ){

  193618. 

  193619.     /* Commit the transaction to the *-oal file. */

  193620.     if( p->rc==SQLITE_OK && p->eStage==RBU_STAGE_OAL ){

  193621.       p->rc = sqlite3_exec(p->dbMain, "COMMIT", 0, 0, &p->zErrmsg);

  193622.     }

  193623. 

  193624.     /* Sync the db file if currently doing an incremental checkpoint */

  193625.     if( p->rc==SQLITE_OK && p->eStage==RBU_STAGE_CKPT ){

  193626.       sqlite3_file *pDb = p->pTargetFd->pReal;

  193627.       p->rc = pDb->pMethods->xSync(pDb, SQLITE_SYNC_NORMAL);

  193628.     }

  193629. 

  193630.     rbuSaveState(p, p->eStage);

  193631. 

  193632.     if( p->rc==SQLITE_OK && p->eStage==RBU_STAGE_OAL ){

  193633.       p->rc = sqlite3_exec(p->dbRbu, "COMMIT", 0, 0, &p->zErrmsg);

  193634.     }

  193635. 

  193636.     /* Close any open statement handles. */

  193637.     rbuObjIterFinalize(&p->objiter);

  193638. 

  193639.     /* If this is an RBU vacuum handle and the vacuum has either finished

  193640.     ** successfully or encountered an error, delete the contents of the 

  193641.     ** state table. This causes the next call to sqlite3rbu_vacuum() 

  193642.     ** specifying the current target and state databases to start a new

  193643.     ** vacuum from scratch.  */

  193644.     if( rbuIsVacuum(p) && p->rc!=SQLITE_OK && p->dbRbu ){

  193645.       int rc2 = sqlite3_exec(p->dbRbu, "DELETE FROM stat.rbu_state", 0, 0, 0);

  193646.       if( p->rc==SQLITE_DONE && rc2!=SQLITE_OK ) p->rc = rc2;

  193647.     }

  193648. 

  193649.     /* Close the open database handle and VFS object. */

  193650.     sqlite3_close(p->dbRbu);

  193651.     sqlite3_close(p->dbMain);

  193652.     assert( p->szTemp==0 );

  193653.     rbuDeleteVfs(p);

  193654.     sqlite3_free(p->aBuf);

  193655.     sqlite3_free(p->aFrame);

  193656. 

  193657.     rbuEditErrmsg(p);

  193658.     rc = p->rc;

  193659.     if( pzErrmsg ){

  193660.       *pzErrmsg = p->zErrmsg;

  193661.     }else{

  193662.       sqlite3_free(p->zErrmsg);

  193663.     }

  193664.     sqlite3_free(p->zState);

  193665.     sqlite3_free(p);

  193666.   }else{

  193667.     rc = SQLITE_NOMEM;

  193668.     *pzErrmsg = 0;

  193669.   }

  193670.   return rc;

  193671. }

  193672. 

  193673. /*

  193674. ** Return the total number of key-value operations (inserts, deletes or 

  193675. ** updates) that have been performed on the target database since the

  193676. ** current RBU update was started.

  193677. */

  193678. SQLITE_API sqlite3_int64 sqlite3rbu_progress(sqlite3rbu *pRbu){

  193679.   return pRbu->nProgress;

  193680. }

  193681. 

  193682. /*

  193683. ** Return permyriadage progress indications for the two main stages of

  193684. ** an RBU update.

  193685. */

  193686. SQLITE_API void sqlite3rbu_bp_progress(sqlite3rbu *p, int *pnOne, int *pnTwo){

  193687.   const int MAX_PROGRESS = 10000;

  193688.   switch( p->eStage ){

  193689.     case RBU_STAGE_OAL:

  193690.       if( p->nPhaseOneStep>0 ){

  193691.         *pnOne = (int)(MAX_PROGRESS * (i64)p->nProgress/(i64)p->nPhaseOneStep);

  193692.       }else{

  193693.         *pnOne = -1;

  193694.       }

  193695.       *pnTwo = 0;

  193696.       break;

  193697. 

  193698.     case RBU_STAGE_MOVE:

  193699.       *pnOne = MAX_PROGRESS;

  193700.       *pnTwo = 0;

  193701.       break;

  193702. 

  193703.     case RBU_STAGE_CKPT:

  193704.       *pnOne = MAX_PROGRESS;

  193705.       *pnTwo = (int)(MAX_PROGRESS * (i64)p->nStep / (i64)p->nFrame);

  193706.       break;

  193707. 

  193708.     case RBU_STAGE_DONE:

  193709.       *pnOne = MAX_PROGRESS;

  193710.       *pnTwo = MAX_PROGRESS;

  193711.       break;

  193712. 

  193713.     default:

  193714.       assert( 0 );

  193715.   }

  193716. }

  193717. 

  193718. /*

  193719. ** Return the current state of the RBU vacuum or update operation.

  193720. */

  193721. SQLITE_API int sqlite3rbu_state(sqlite3rbu *p){

  193722.   int aRes[] = {

  193723.     0, SQLITE_RBU_STATE_OAL, SQLITE_RBU_STATE_MOVE,

  193724.     0, SQLITE_RBU_STATE_CHECKPOINT, SQLITE_RBU_STATE_DONE

  193725.   };

  193726. 

  193727.   assert( RBU_STAGE_OAL==1 );

  193728.   assert( RBU_STAGE_MOVE==2 );

  193729.   assert( RBU_STAGE_CKPT==4 );

  193730.   assert( RBU_STAGE_DONE==5 );

  193731.   assert( aRes[RBU_STAGE_OAL]==SQLITE_RBU_STATE_OAL );

  193732.   assert( aRes[RBU_STAGE_MOVE]==SQLITE_RBU_STATE_MOVE );

  193733.   assert( aRes[RBU_STAGE_CKPT]==SQLITE_RBU_STATE_CHECKPOINT );

  193734.   assert( aRes[RBU_STAGE_DONE]==SQLITE_RBU_STATE_DONE );

  193735. 

  193736.   if( p->rc!=SQLITE_OK && p->rc!=SQLITE_DONE ){

  193737.     return SQLITE_RBU_STATE_ERROR;

  193738.   }else{

  193739.     assert( p->rc!=SQLITE_DONE || p->eStage==RBU_STAGE_DONE );

  193740.     assert( p->eStage==RBU_STAGE_OAL

  193741.          || p->eStage==RBU_STAGE_MOVE

  193742.          || p->eStage==RBU_STAGE_CKPT

  193743.          || p->eStage==RBU_STAGE_DONE

  193744.     );

  193745.     return aRes[p->eStage];

  193746.   }

  193747. }

  193748. 

  193749. SQLITE_API int sqlite3rbu_savestate(sqlite3rbu *p){

  193750.   int rc = p->rc;

  193751.   if( rc==SQLITE_DONE ) return SQLITE_OK;

  193752. 

  193753.   assert( p->eStage>=RBU_STAGE_OAL && p->eStage<=RBU_STAGE_DONE );

  193754.   if( p->eStage==RBU_STAGE_OAL ){

  193755.     assert( rc!=SQLITE_DONE );

  193756.     if( rc==SQLITE_OK ) rc = sqlite3_exec(p->dbMain, "COMMIT", 0, 0, 0);

  193757.   }

  193758. 

  193759.   /* Sync the db file */

  193760.   if( rc==SQLITE_OK && p->eStage==RBU_STAGE_CKPT ){

  193761.     sqlite3_file *pDb = p->pTargetFd->pReal;

  193762.     rc = pDb->pMethods->xSync(pDb, SQLITE_SYNC_NORMAL);

  193763.   }

  193764. 

  193765.   p->rc = rc;

  193766.   rbuSaveState(p, p->eStage);

  193767.   rc = p->rc;

  193768. 

  193769.   if( p->eStage==RBU_STAGE_OAL ){

  193770.     assert( rc!=SQLITE_DONE );

  193771.     if( rc==SQLITE_OK ) rc = sqlite3_exec(p->dbRbu, "COMMIT", 0, 0, 0);

  193772.     if( rc==SQLITE_OK ){ 

  193773.       const char *zBegin = rbuIsVacuum(p) ? "BEGIN" : "BEGIN IMMEDIATE";

  193774.       rc = sqlite3_exec(p->dbRbu, zBegin, 0, 0, 0);

  193775.     }

  193776.     if( rc==SQLITE_OK ) rc = sqlite3_exec(p->dbMain, "BEGIN IMMEDIATE", 0, 0,0);

  193777.   }

  193778. 

  193779.   p->rc = rc;

  193780.   return rc;

  193781. }

  193782. 

  193783. /**************************************************************************

  193784. ** Beginning of RBU VFS shim methods. The VFS shim modifies the behaviour

  193785. ** of a standard VFS in the following ways:

  193786. **

  193787. ** 1. Whenever the first page of a main database file is read or 

  193788. **    written, the value of the change-counter cookie is stored in

  193789. **    rbu_file.iCookie. Similarly, the value of the "write-version"

  193790. **    database header field is stored in rbu_file.iWriteVer. This ensures

  193791. **    that the values are always trustworthy within an open transaction.

  193792. **

  193793. ** 2. Whenever an SQLITE_OPEN_WAL file is opened, the (rbu_file.pWalFd)

  193794. **    member variable of the associated database file descriptor is set

  193795. **    to point to the new file. A mutex protected linked list of all main 

  193796. **    db fds opened using a particular RBU VFS is maintained at 

  193797. **    rbu_vfs.pMain to facilitate this.

  193798. **

  193799. ** 3. Using a new file-control "SQLITE_FCNTL_RBU", a main db rbu_file 

  193800. **    object can be marked as the target database of an RBU update. This

  193801. **    turns on the following extra special behaviour:

  193802. **

  193803. ** 3a. If xAccess() is called to check if there exists a *-wal file 

  193804. **     associated with an RBU target database currently in RBU_STAGE_OAL

  193805. **     stage (preparing the *-oal file), the following special handling

  193806. **     applies:

  193807. **

  193808. **      * if the *-wal file does exist, return SQLITE_CANTOPEN. An RBU

  193809. **        target database may not be in wal mode already.

  193810. **

  193811. **      * if the *-wal file does not exist, set the output parameter to

  193812. **        non-zero (to tell SQLite that it does exist) anyway.

  193813. **

  193814. **     Then, when xOpen() is called to open the *-wal file associated with

  193815. **     the RBU target in RBU_STAGE_OAL stage, instead of opening the *-wal

  193816. **     file, the rbu vfs opens the corresponding *-oal file instead. 

  193817. **

  193818. ** 3b. The *-shm pages returned by xShmMap() for a target db file in

  193819. **     RBU_STAGE_OAL mode are actually stored in heap memory. This is to

  193820. **     avoid creating a *-shm file on disk. Additionally, xShmLock() calls

  193821. **     are no-ops on target database files in RBU_STAGE_OAL mode. This is

  193822. **     because assert() statements in some VFS implementations fail if 

  193823. **     xShmLock() is called before xShmMap().

  193824. **

  193825. ** 3c. If an EXCLUSIVE lock is attempted on a target database file in any

  193826. **     mode except RBU_STAGE_DONE (all work completed and checkpointed), it 

  193827. **     fails with an SQLITE_BUSY error. This is to stop RBU connections

  193828. **     from automatically checkpointing a *-wal (or *-oal) file from within

  193829. **     sqlite3_close().

  193830. **

  193831. ** 3d. In RBU_STAGE_CAPTURE mode, all xRead() calls on the wal file, and

  193832. **     all xWrite() calls on the target database file perform no IO. 

  193833. **     Instead the frame and page numbers that would be read and written

  193834. **     are recorded. Additionally, successful attempts to obtain exclusive

  193835. **     xShmLock() WRITER, CHECKPOINTER and READ0 locks on the target 

  193836. **     database file are recorded. xShmLock() calls to unlock the same

  193837. **     locks are no-ops (so that once obtained, these locks are never

  193838. **     relinquished). Finally, calls to xSync() on the target database

  193839. **     file fail with SQLITE_INTERNAL errors.

  193840. */

  193841. 

  193842. static void rbuUnlockShm(rbu_file *p){

  193843.   assert( p->openFlags & SQLITE_OPEN_MAIN_DB );

  193844.   if( p->pRbu ){

  193845.     int (*xShmLock)(sqlite3_file*,int,int,int) = p->pReal->pMethods->xShmLock;

  193846.     int i;

  193847.     for(i=0; i<SQLITE_SHM_NLOCK;i++){

  193848.       if( (1<<i) & p->pRbu->mLock ){

  193849.         xShmLock(p->pReal, i, 1, SQLITE_SHM_UNLOCK|SQLITE_SHM_EXCLUSIVE);

  193850.       }

  193851.     }

  193852.     p->pRbu->mLock = 0;

  193853.   }

  193854. }

  193855. 

  193856. /*

  193857. */

  193858. static int rbuUpdateTempSize(rbu_file *pFd, sqlite3_int64 nNew){

  193859.   sqlite3rbu *pRbu = pFd->pRbu;

  193860.   i64 nDiff = nNew - pFd->sz;

  193861.   pRbu->szTemp += nDiff;

  193862.   pFd->sz = nNew;

  193863.   assert( pRbu->szTemp>=0 );

  193864.   if( pRbu->szTempLimit && pRbu->szTemp>pRbu->szTempLimit ) return SQLITE_FULL;

  193865.   return SQLITE_OK;

  193866. }

  193867. 

  193868. /*

  193869. ** Add an item to the main-db lists, if it is not already present.

  193870. **

  193871. ** There are two main-db lists. One for all file descriptors, and one

  193872. ** for all file descriptors with rbu_file.pDb!=0. If the argument has

  193873. ** rbu_file.pDb!=0, then it is assumed to already be present on the

  193874. ** main list and is only added to the pDb!=0 list.

  193875. */

  193876. static void rbuMainlistAdd(rbu_file *p){

  193877.   rbu_vfs *pRbuVfs = p->pRbuVfs;

  193878.   rbu_file *pIter;

  193879.   assert( (p->openFlags & SQLITE_OPEN_MAIN_DB) );

  193880.   sqlite3_mutex_enter(pRbuVfs->mutex);

  193881.   if( p->pRbu==0 ){

  193882.     for(pIter=pRbuVfs->pMain; pIter; pIter=pIter->pMainNext);

  193883.     p->pMainNext = pRbuVfs->pMain;

  193884.     pRbuVfs->pMain = p;

  193885.   }else{

  193886.     for(pIter=pRbuVfs->pMainRbu; pIter && pIter!=p; pIter=pIter->pMainRbuNext){}

  193887.     if( pIter==0 ){

  193888.       p->pMainRbuNext = pRbuVfs->pMainRbu;

  193889.       pRbuVfs->pMainRbu = p;

  193890.     }

  193891.   }

  193892.   sqlite3_mutex_leave(pRbuVfs->mutex);

  193893. }

  193894. 

  193895. /*

  193896. ** Remove an item from the main-db lists.

  193897. */

  193898. static void rbuMainlistRemove(rbu_file *p){

  193899.   rbu_file **pp;

  193900.   sqlite3_mutex_enter(p->pRbuVfs->mutex);

  193901.   for(pp=&p->pRbuVfs->pMain; *pp && *pp!=p; pp=&((*pp)->pMainNext)){}

  193902.   if( *pp ) *pp = p->pMainNext;

  193903.   p->pMainNext = 0;

  193904.   for(pp=&p->pRbuVfs->pMainRbu; *pp && *pp!=p; pp=&((*pp)->pMainRbuNext)){}

  193905.   if( *pp ) *pp = p->pMainRbuNext;

  193906.   p->pMainRbuNext = 0;

  193907.   sqlite3_mutex_leave(p->pRbuVfs->mutex);

  193908. }

  193909. 

  193910. /*

  193911. ** Given that zWal points to a buffer containing a wal file name passed to 

  193912. ** either the xOpen() or xAccess() VFS method, search the main-db list for

  193913. ** a file-handle opened by the same database connection on the corresponding

  193914. ** database file.

  193915. **

  193916. ** If parameter bRbu is true, only search for file-descriptors with

  193917. ** rbu_file.pDb!=0.

  193918. */

  193919. static rbu_file *rbuFindMaindb(rbu_vfs *pRbuVfs, const char *zWal, int bRbu){

  193920.   rbu_file *pDb;

  193921.   sqlite3_mutex_enter(pRbuVfs->mutex);

  193922.   if( bRbu ){

  193923.     for(pDb=pRbuVfs->pMainRbu; pDb && pDb->zWal!=zWal; pDb=pDb->pMainRbuNext){}

  193924.   }else{

  193925.     for(pDb=pRbuVfs->pMain; pDb && pDb->zWal!=zWal; pDb=pDb->pMainNext){}

  193926.   }

  193927.   sqlite3_mutex_leave(pRbuVfs->mutex);

  193928.   return pDb;

  193929. }

  193930. 

  193931. /*

  193932. ** Close an rbu file.

  193933. */

  193934. static int rbuVfsClose(sqlite3_file *pFile){

  193935.   rbu_file *p = (rbu_file*)pFile;

  193936.   int rc;

  193937.   int i;

  193938. 

  193939.   /* Free the contents of the apShm[] array. And the array itself. */

  193940.   for(i=0; i<p->nShm; i++){

  193941.     sqlite3_free(p->apShm[i]);

  193942.   }

  193943.   sqlite3_free(p->apShm);

  193944.   p->apShm = 0;

  193945.   sqlite3_free(p->zDel);

  193946. 

  193947.   if( p->openFlags & SQLITE_OPEN_MAIN_DB ){

  193948.     rbuMainlistRemove(p);

  193949.     rbuUnlockShm(p);

  193950.     p->pReal->pMethods->xShmUnmap(p->pReal, 0);

  193951.   }

  193952.   else if( (p->openFlags & SQLITE_OPEN_DELETEONCLOSE) && p->pRbu ){

  193953.     rbuUpdateTempSize(p, 0);

  193954.   }

  193955.   assert( p->pMainNext==0 && p->pRbuVfs->pMain!=p );

  193956. 

  193957.   /* Close the underlying file handle */

  193958.   rc = p->pReal->pMethods->xClose(p->pReal);

  193959.   return rc;

  193960. }

  193961. 

  193962. 

  193963. /*

  193964. ** Read and return an unsigned 32-bit big-endian integer from the buffer 

  193965. ** passed as the only argument.

  193966. */

  193967. static u32 rbuGetU32(u8 *aBuf){

  193968.   return ((u32)aBuf[0] << 24)

  193969.        + ((u32)aBuf[1] << 16)

  193970.        + ((u32)aBuf[2] <<  8)

  193971.        + ((u32)aBuf[3]);

  193972. }

  193973. 

  193974. /*

  193975. ** Write an unsigned 32-bit value in big-endian format to the supplied

  193976. ** buffer.

  193977. */

  193978. static void rbuPutU32(u8 *aBuf, u32 iVal){

  193979.   aBuf[0] = (iVal >> 24) & 0xFF;

  193980.   aBuf[1] = (iVal >> 16) & 0xFF;

  193981.   aBuf[2] = (iVal >>  8) & 0xFF;

  193982.   aBuf[3] = (iVal >>  0) & 0xFF;

  193983. }

  193984. 

  193985. static void rbuPutU16(u8 *aBuf, u16 iVal){

  193986.   aBuf[0] = (iVal >>  8) & 0xFF;

  193987.   aBuf[1] = (iVal >>  0) & 0xFF;

  193988. }

  193989. 

  193990. /*

  193991. ** Read data from an rbuVfs-file.

  193992. */

  193993. static int rbuVfsRead(

  193994.   sqlite3_file *pFile, 

  193995.   void *zBuf, 

  193996.   int iAmt, 

  193997.   sqlite_int64 iOfst

  193998. ){

  193999.   rbu_file *p = (rbu_file*)pFile;

  194000.   sqlite3rbu *pRbu = p->pRbu;

  194001.   int rc;

  194002. 

  194003.   if( pRbu && pRbu->eStage==RBU_STAGE_CAPTURE ){

  194004.     assert( p->openFlags & SQLITE_OPEN_WAL );

  194005.     rc = rbuCaptureWalRead(p->pRbu, iOfst, iAmt);

  194006.   }else{

  194007.     if( pRbu && pRbu->eStage==RBU_STAGE_OAL 

  194008.      && (p->openFlags & SQLITE_OPEN_WAL) 

  194009.      && iOfst>=pRbu->iOalSz 

  194010.     ){

  194011.       rc = SQLITE_OK;

  194012.       memset(zBuf, 0, iAmt);

  194013.     }else{

  194014.       rc = p->pReal->pMethods->xRead(p->pReal, zBuf, iAmt, iOfst);

  194015. #if 1

  194016.       /* If this is being called to read the first page of the target 

  194017.       ** database as part of an rbu vacuum operation, synthesize the 

  194018.       ** contents of the first page if it does not yet exist. Otherwise,

  194019.       ** SQLite will not check for a *-wal file.  */

  194020.       if( pRbu && rbuIsVacuum(pRbu) 

  194021.           && rc==SQLITE_IOERR_SHORT_READ && iOfst==0

  194022.           && (p->openFlags & SQLITE_OPEN_MAIN_DB)

  194023.           && pRbu->rc==SQLITE_OK

  194024.       ){

  194025.         sqlite3_file *pFd = (sqlite3_file*)pRbu->pRbuFd;

  194026.         rc = pFd->pMethods->xRead(pFd, zBuf, iAmt, iOfst);

  194027.         if( rc==SQLITE_OK ){

  194028.           u8 *aBuf = (u8*)zBuf;

  194029.           u32 iRoot = rbuGetU32(&aBuf[52]) ? 1 : 0;

  194030.           rbuPutU32(&aBuf[52], iRoot);      /* largest root page number */

  194031.           rbuPutU32(&aBuf[36], 0);          /* number of free pages */

  194032.           rbuPutU32(&aBuf[32], 0);          /* first page on free list trunk */

  194033.           rbuPutU32(&aBuf[28], 1);          /* size of db file in pages */

  194034.           rbuPutU32(&aBuf[24], pRbu->pRbuFd->iCookie+1);  /* Change counter */

  194035. 

  194036.           if( iAmt>100 ){

  194037.             memset(&aBuf[100], 0, iAmt-100);

  194038.             rbuPutU16(&aBuf[105], iAmt & 0xFFFF);

  194039.             aBuf[100] = 0x0D;

  194040.           }

  194041.         }

  194042.       }

  194043. #endif

  194044.     }

  194045.     if( rc==SQLITE_OK && iOfst==0 && (p->openFlags & SQLITE_OPEN_MAIN_DB) ){

  194046.       /* These look like magic numbers. But they are stable, as they are part

  194047.        ** of the definition of the SQLite file format, which may not change. */

  194048.       u8 *pBuf = (u8*)zBuf;

  194049.       p->iCookie = rbuGetU32(&pBuf[24]);

  194050.       p->iWriteVer = pBuf[19];

  194051.     }

  194052.   }

  194053.   return rc;

  194054. }

  194055. 

  194056. /*

  194057. ** Write data to an rbuVfs-file.

  194058. */

  194059. static int rbuVfsWrite(

  194060.   sqlite3_file *pFile, 

  194061.   const void *zBuf, 

  194062.   int iAmt, 

  194063.   sqlite_int64 iOfst

  194064. ){

  194065.   rbu_file *p = (rbu_file*)pFile;

  194066.   sqlite3rbu *pRbu = p->pRbu;

  194067.   int rc;

  194068. 

  194069.   if( pRbu && pRbu->eStage==RBU_STAGE_CAPTURE ){

  194070.     assert( p->openFlags & SQLITE_OPEN_MAIN_DB );

  194071.     rc = rbuCaptureDbWrite(p->pRbu, iOfst);

  194072.   }else{

  194073.     if( pRbu ){

  194074.       if( pRbu->eStage==RBU_STAGE_OAL 

  194075.        && (p->openFlags & SQLITE_OPEN_WAL) 

  194076.        && iOfst>=pRbu->iOalSz

  194077.       ){

  194078.         pRbu->iOalSz = iAmt + iOfst;

  194079.       }else if( p->openFlags & SQLITE_OPEN_DELETEONCLOSE ){

  194080.         i64 szNew = iAmt+iOfst;

  194081.         if( szNew>p->sz ){

  194082.           rc = rbuUpdateTempSize(p, szNew);

  194083.           if( rc!=SQLITE_OK ) return rc;

  194084.         }

  194085.       }

  194086.     }

  194087.     rc = p->pReal->pMethods->xWrite(p->pReal, zBuf, iAmt, iOfst);

  194088.     if( rc==SQLITE_OK && iOfst==0 && (p->openFlags & SQLITE_OPEN_MAIN_DB) ){

  194089.       /* These look like magic numbers. But they are stable, as they are part

  194090.       ** of the definition of the SQLite file format, which may not change. */

  194091.       u8 *pBuf = (u8*)zBuf;

  194092.       p->iCookie = rbuGetU32(&pBuf[24]);

  194093.       p->iWriteVer = pBuf[19];

  194094.     }

  194095.   }

  194096.   return rc;

  194097. }

  194098. 

  194099. /*

  194100. ** Truncate an rbuVfs-file.

  194101. */

  194102. static int rbuVfsTruncate(sqlite3_file *pFile, sqlite_int64 size){

  194103.   rbu_file *p = (rbu_file*)pFile;

  194104.   if( (p->openFlags & SQLITE_OPEN_DELETEONCLOSE) && p->pRbu ){

  194105.     int rc = rbuUpdateTempSize(p, size);

  194106.     if( rc!=SQLITE_OK ) return rc;

  194107.   }

  194108.   return p->pReal->pMethods->xTruncate(p->pReal, size);

  194109. }

  194110. 

  194111. /*

  194112. ** Sync an rbuVfs-file.

  194113. */

  194114. static int rbuVfsSync(sqlite3_file *pFile, int flags){

  194115.   rbu_file *p = (rbu_file *)pFile;

  194116.   if( p->pRbu && p->pRbu->eStage==RBU_STAGE_CAPTURE ){

  194117.     if( p->openFlags & SQLITE_OPEN_MAIN_DB ){

  194118.       return SQLITE_INTERNAL;

  194119.     }

  194120.     return SQLITE_OK;

  194121.   }

  194122.   return p->pReal->pMethods->xSync(p->pReal, flags);

  194123. }

  194124. 

  194125. /*

  194126. ** Return the current file-size of an rbuVfs-file.

  194127. */

  194128. static int rbuVfsFileSize(sqlite3_file *pFile, sqlite_int64 *pSize){

  194129.   rbu_file *p = (rbu_file *)pFile;

  194130.   int rc;

  194131.   rc = p->pReal->pMethods->xFileSize(p->pReal, pSize);

  194132. 

  194133.   /* If this is an RBU vacuum operation and this is the target database,

  194134.   ** pretend that it has at least one page. Otherwise, SQLite will not

  194135.   ** check for the existance of a *-wal file. rbuVfsRead() contains 

  194136.   ** similar logic.  */

  194137.   if( rc==SQLITE_OK && *pSize==0 

  194138.    && p->pRbu && rbuIsVacuum(p->pRbu) 

  194139.    && (p->openFlags & SQLITE_OPEN_MAIN_DB)

  194140.   ){

  194141.     *pSize = 1024;

  194142.   }

  194143.   return rc;

  194144. }

  194145. 

  194146. /*

  194147. ** Lock an rbuVfs-file.

  194148. */

  194149. static int rbuVfsLock(sqlite3_file *pFile, int eLock){

  194150.   rbu_file *p = (rbu_file*)pFile;

  194151.   sqlite3rbu *pRbu = p->pRbu;

  194152.   int rc = SQLITE_OK;

  194153. 

  194154.   assert( p->openFlags & (SQLITE_OPEN_MAIN_DB|SQLITE_OPEN_TEMP_DB) );

  194155.   if( eLock==SQLITE_LOCK_EXCLUSIVE 

  194156.    && (p->bNolock || (pRbu && pRbu->eStage!=RBU_STAGE_DONE))

  194157.   ){

  194158.     /* Do not allow EXCLUSIVE locks. Preventing SQLite from taking this 

  194159.     ** prevents it from checkpointing the database from sqlite3_close(). */

  194160.     rc = SQLITE_BUSY;

  194161.   }else{

  194162.     rc = p->pReal->pMethods->xLock(p->pReal, eLock);

  194163.   }

  194164. 

  194165.   return rc;

  194166. }

  194167. 

  194168. /*

  194169. ** Unlock an rbuVfs-file.

  194170. */

  194171. static int rbuVfsUnlock(sqlite3_file *pFile, int eLock){

  194172.   rbu_file *p = (rbu_file *)pFile;

  194173.   return p->pReal->pMethods->xUnlock(p->pReal, eLock);

  194174. }

  194175. 

  194176. /*

  194177. ** Check if another file-handle holds a RESERVED lock on an rbuVfs-file.

  194178. */

  194179. static int rbuVfsCheckReservedLock(sqlite3_file *pFile, int *pResOut){

  194180.   rbu_file *p = (rbu_file *)pFile;

  194181.   return p->pReal->pMethods->xCheckReservedLock(p->pReal, pResOut);

  194182. }

  194183. 

  194184. /*

  194185. ** File control method. For custom operations on an rbuVfs-file.

  194186. */

  194187. static int rbuVfsFileControl(sqlite3_file *pFile, int op, void *pArg){

  194188.   rbu_file *p = (rbu_file *)pFile;

  194189.   int (*xControl)(sqlite3_file*,int,void*) = p->pReal->pMethods->xFileControl;

  194190.   int rc;

  194191. 

  194192.   assert( p->openFlags & (SQLITE_OPEN_MAIN_DB|SQLITE_OPEN_TEMP_DB)

  194193.        || p->openFlags & (SQLITE_OPEN_TRANSIENT_DB|SQLITE_OPEN_TEMP_JOURNAL)

  194194.   );

  194195.   if( op==SQLITE_FCNTL_RBU ){

  194196.     sqlite3rbu *pRbu = (sqlite3rbu*)pArg;

  194197. 

  194198.     /* First try to find another RBU vfs lower down in the vfs stack. If

  194199.     ** one is found, this vfs will operate in pass-through mode. The lower

  194200.     ** level vfs will do the special RBU handling.  */

  194201.     rc = xControl(p->pReal, op, pArg);

  194202. 

  194203.     if( rc==SQLITE_NOTFOUND ){

  194204.       /* Now search for a zipvfs instance lower down in the VFS stack. If

  194205.       ** one is found, this is an error.  */

  194206.       void *dummy = 0;

  194207.       rc = xControl(p->pReal, SQLITE_FCNTL_ZIPVFS, &dummy);

  194208.       if( rc==SQLITE_OK ){

  194209.         rc = SQLITE_ERROR;

  194210.         pRbu->zErrmsg = sqlite3_mprintf("rbu/zipvfs setup error");

  194211.       }else if( rc==SQLITE_NOTFOUND ){

  194212.         pRbu->pTargetFd = p;

  194213.         p->pRbu = pRbu;

  194214.         rbuMainlistAdd(p);

  194215.         if( p->pWalFd ) p->pWalFd->pRbu = pRbu;

  194216.         rc = SQLITE_OK;

  194217.       }

  194218.     }

  194219.     return rc;

  194220.   }

  194221.   else if( op==SQLITE_FCNTL_RBUCNT ){

  194222.     sqlite3rbu *pRbu = (sqlite3rbu*)pArg;

  194223.     pRbu->nRbu++;

  194224.     pRbu->pRbuFd = p;

  194225.     p->bNolock = 1;

  194226.   }

  194227. 

  194228.   rc = xControl(p->pReal, op, pArg);

  194229.   if( rc==SQLITE_OK && op==SQLITE_FCNTL_VFSNAME ){

  194230.     rbu_vfs *pRbuVfs = p->pRbuVfs;

  194231.     char *zIn = *(char**)pArg;

  194232.     char *zOut = sqlite3_mprintf("rbu(%s)/%z", pRbuVfs->base.zName, zIn);

  194233.     *(char**)pArg = zOut;

  194234.     if( zOut==0 ) rc = SQLITE_NOMEM;

  194235.   }

  194236. 

  194237.   return rc;

  194238. }

  194239. 

  194240. /*

  194241. ** Return the sector-size in bytes for an rbuVfs-file.

  194242. */

  194243. static int rbuVfsSectorSize(sqlite3_file *pFile){

  194244.   rbu_file *p = (rbu_file *)pFile;

  194245.   return p->pReal->pMethods->xSectorSize(p->pReal);

  194246. }

  194247. 

  194248. /*

  194249. ** Return the device characteristic flags supported by an rbuVfs-file.

  194250. */

  194251. static int rbuVfsDeviceCharacteristics(sqlite3_file *pFile){

  194252.   rbu_file *p = (rbu_file *)pFile;

  194253.   return p->pReal->pMethods->xDeviceCharacteristics(p->pReal);

  194254. }

  194255. 

  194256. /*

  194257. ** Take or release a shared-memory lock.

  194258. */

  194259. static int rbuVfsShmLock(sqlite3_file *pFile, int ofst, int n, int flags){

  194260.   rbu_file *p = (rbu_file*)pFile;

  194261.   sqlite3rbu *pRbu = p->pRbu;

  194262.   int rc = SQLITE_OK;

  194263. 

  194264. #ifdef SQLITE_AMALGAMATION

  194265.     assert( WAL_CKPT_LOCK==1 );

  194266. #endif

  194267. 

  194268.   assert( p->openFlags & (SQLITE_OPEN_MAIN_DB|SQLITE_OPEN_TEMP_DB) );

  194269.   if( pRbu && (pRbu->eStage==RBU_STAGE_OAL || pRbu->eStage==RBU_STAGE_MOVE) ){

  194270.     /* Magic number 1 is the WAL_CKPT_LOCK lock. Preventing SQLite from

  194271.     ** taking this lock also prevents any checkpoints from occurring. 

  194272.     ** todo: really, it's not clear why this might occur, as 

  194273.     ** wal_autocheckpoint ought to be turned off.  */

  194274.     if( ofst==WAL_LOCK_CKPT && n==1 ) rc = SQLITE_BUSY;

  194275.   }else{

  194276.     int bCapture = 0;

  194277.     if( pRbu && pRbu->eStage==RBU_STAGE_CAPTURE ){

  194278.       bCapture = 1;

  194279.     }

  194280. 

  194281.     if( bCapture==0 || 0==(flags & SQLITE_SHM_UNLOCK) ){

  194282.       rc = p->pReal->pMethods->xShmLock(p->pReal, ofst, n, flags);

  194283.       if( bCapture && rc==SQLITE_OK ){

  194284.         pRbu->mLock |= (1 << ofst);

  194285.       }

  194286.     }

  194287.   }

  194288. 

  194289.   return rc;

  194290. }

  194291. 

  194292. /*

  194293. ** Obtain a pointer to a mapping of a single 32KiB page of the *-shm file.

  194294. */

  194295. static int rbuVfsShmMap(

  194296.   sqlite3_file *pFile, 

  194297.   int iRegion, 

  194298.   int szRegion, 

  194299.   int isWrite, 

  194300.   void volatile **pp

  194301. ){

  194302.   rbu_file *p = (rbu_file*)pFile;

  194303.   int rc = SQLITE_OK;

  194304.   int eStage = (p->pRbu ? p->pRbu->eStage : 0);

  194305. 

  194306.   /* If not in RBU_STAGE_OAL, allow this call to pass through. Or, if this

  194307.   ** rbu is in the RBU_STAGE_OAL state, use heap memory for *-shm space 

  194308.   ** instead of a file on disk.  */

  194309.   assert( p->openFlags & (SQLITE_OPEN_MAIN_DB|SQLITE_OPEN_TEMP_DB) );

  194310.   if( eStage==RBU_STAGE_OAL ){

  194311.     sqlite3_int64 nByte = (iRegion+1) * sizeof(char*);

  194312.     char **apNew = (char**)sqlite3_realloc64(p->apShm, nByte);

  194313. 

  194314.     /* This is an RBU connection that uses its own heap memory for the

  194315.     ** pages of the *-shm file. Since no other process can have run

  194316.     ** recovery, the connection must request *-shm pages in order

  194317.     ** from start to finish.  */

  194318.     assert( iRegion==p->nShm );

  194319.     if( apNew==0 ){

  194320.       rc = SQLITE_NOMEM;

  194321.     }else{

  194322.       memset(&apNew[p->nShm], 0, sizeof(char*) * (1 + iRegion - p->nShm));

  194323.       p->apShm = apNew;

  194324.       p->nShm = iRegion+1;

  194325.     }

  194326. 

  194327.     if( rc==SQLITE_OK ){

  194328.       char *pNew = (char*)sqlite3_malloc64(szRegion);

  194329.       if( pNew==0 ){

  194330.         rc = SQLITE_NOMEM;

  194331.       }else{

  194332.         memset(pNew, 0, szRegion);

  194333.         p->apShm[iRegion] = pNew;

  194334.       }

  194335.     }

  194336. 

  194337.     if( rc==SQLITE_OK ){

  194338.       *pp = p->apShm[iRegion];

  194339.     }else{

  194340.       *pp = 0;

  194341.     }

  194342.   }else{

  194343.     assert( p->apShm==0 );

  194344.     rc = p->pReal->pMethods->xShmMap(p->pReal, iRegion, szRegion, isWrite, pp);

  194345.   }

  194346. 

  194347.   return rc;

  194348. }

  194349. 

  194350. /*

  194351. ** Memory barrier.

  194352. */

  194353. static void rbuVfsShmBarrier(sqlite3_file *pFile){

  194354.   rbu_file *p = (rbu_file *)pFile;

  194355.   p->pReal->pMethods->xShmBarrier(p->pReal);

  194356. }

  194357. 

  194358. /*

  194359. ** The xShmUnmap method.

  194360. */

  194361. static int rbuVfsShmUnmap(sqlite3_file *pFile, int delFlag){

  194362.   rbu_file *p = (rbu_file*)pFile;

  194363.   int rc = SQLITE_OK;

  194364.   int eStage = (p->pRbu ? p->pRbu->eStage : 0);

  194365. 

  194366.   assert( p->openFlags & (SQLITE_OPEN_MAIN_DB|SQLITE_OPEN_TEMP_DB) );

  194367.   if( eStage==RBU_STAGE_OAL || eStage==RBU_STAGE_MOVE ){

  194368.     /* no-op */

  194369.   }else{

  194370.     /* Release the checkpointer and writer locks */

  194371.     rbuUnlockShm(p);

  194372.     rc = p->pReal->pMethods->xShmUnmap(p->pReal, delFlag);

  194373.   }

  194374.   return rc;

  194375. }

  194376. 

  194377. /* 

  194378. ** A main database named zName has just been opened. The following 

  194379. ** function returns a pointer to a buffer owned by SQLite that contains

  194380. ** the name of the *-wal file this db connection will use. SQLite

  194381. ** happens to pass a pointer to this buffer when using xAccess()

  194382. ** or xOpen() to operate on the *-wal file.  

  194383. */

  194384. static const char *rbuMainToWal(const char *zName, int flags){

  194385.   int n = (int)strlen(zName);

  194386.   const char *z = &zName[n];

  194387.   if( flags & SQLITE_OPEN_URI ){

  194388.     int odd = 0;

  194389.     while( 1 ){

  194390.       if( z[0]==0 ){

  194391.         odd = 1 - odd;

  194392.         if( odd && z[1]==0 ) break;

  194393.       }

  194394.       z++;

  194395.     }

  194396.     z += 2;

  194397.   }else{

  194398.     while( *z==0 ) z++;

  194399.   }

  194400.   z += (n + 8 + 1);

  194401.   return z;

  194402. }

  194403. 

  194404. /*

  194405. ** Open an rbu file handle.

  194406. */

  194407. static int rbuVfsOpen(

  194408.   sqlite3_vfs *pVfs,

  194409.   const char *zName,

  194410.   sqlite3_file *pFile,

  194411.   int flags,

  194412.   int *pOutFlags

  194413. ){

  194414.   static sqlite3_io_methods rbuvfs_io_methods = {

  194415.     2,                            /* iVersion */

  194416.     rbuVfsClose,                  /* xClose */

  194417.     rbuVfsRead,                   /* xRead */

  194418.     rbuVfsWrite,                  /* xWrite */

  194419.     rbuVfsTruncate,               /* xTruncate */

  194420.     rbuVfsSync,                   /* xSync */

  194421.     rbuVfsFileSize,               /* xFileSize */

  194422.     rbuVfsLock,                   /* xLock */

  194423.     rbuVfsUnlock,                 /* xUnlock */

  194424.     rbuVfsCheckReservedLock,      /* xCheckReservedLock */

  194425.     rbuVfsFileControl,            /* xFileControl */

  194426.     rbuVfsSectorSize,             /* xSectorSize */

  194427.     rbuVfsDeviceCharacteristics,  /* xDeviceCharacteristics */

  194428.     rbuVfsShmMap,                 /* xShmMap */

  194429.     rbuVfsShmLock,                /* xShmLock */

  194430.     rbuVfsShmBarrier,             /* xShmBarrier */

  194431.     rbuVfsShmUnmap,               /* xShmUnmap */

  194432.     0, 0                          /* xFetch, xUnfetch */

  194433.   };

  194434.   rbu_vfs *pRbuVfs = (rbu_vfs*)pVfs;

  194435.   sqlite3_vfs *pRealVfs = pRbuVfs->pRealVfs;

  194436.   rbu_file *pFd = (rbu_file *)pFile;

  194437.   int rc = SQLITE_OK;

  194438.   const char *zOpen = zName;

  194439.   int oflags = flags;

  194440. 

  194441.   memset(pFd, 0, sizeof(rbu_file));

  194442.   pFd->pReal = (sqlite3_file*)&pFd[1];

  194443.   pFd->pRbuVfs = pRbuVfs;

  194444.   pFd->openFlags = flags;

  194445.   if( zName ){

  194446.     if( flags & SQLITE_OPEN_MAIN_DB ){

  194447.       /* A main database has just been opened. The following block sets

  194448.       ** (pFd->zWal) to point to a buffer owned by SQLite that contains

  194449.       ** the name of the *-wal file this db connection will use. SQLite

  194450.       ** happens to pass a pointer to this buffer when using xAccess()

  194451.       ** or xOpen() to operate on the *-wal file.  */

  194452.       pFd->zWal = rbuMainToWal(zName, flags);

  194453.     }

  194454.     else if( flags & SQLITE_OPEN_WAL ){

  194455.       rbu_file *pDb = rbuFindMaindb(pRbuVfs, zName, 0);

  194456.       if( pDb ){

  194457.         if( pDb->pRbu && pDb->pRbu->eStage==RBU_STAGE_OAL ){

  194458.           /* This call is to open a *-wal file. Intead, open the *-oal. This

  194459.           ** code ensures that the string passed to xOpen() is terminated by a

  194460.           ** pair of '\0' bytes in case the VFS attempts to extract a URI 

  194461.           ** parameter from it.  */

  194462.           const char *zBase = zName;

  194463.           size_t nCopy;

  194464.           char *zCopy;

  194465.           if( rbuIsVacuum(pDb->pRbu) ){

  194466.             zBase = sqlite3_db_filename(pDb->pRbu->dbRbu, "main");

  194467.             zBase = rbuMainToWal(zBase, SQLITE_OPEN_URI);

  194468.           }

  194469.           nCopy = strlen(zBase);

  194470.           zCopy = sqlite3_malloc64(nCopy+2);

  194471.           if( zCopy ){

  194472.             memcpy(zCopy, zBase, nCopy);

  194473.             zCopy[nCopy-3] = 'o';

  194474.             zCopy[nCopy] = '\0';

  194475.             zCopy[nCopy+1] = '\0';

  194476.             zOpen = (const char*)(pFd->zDel = zCopy);

  194477.           }else{

  194478.             rc = SQLITE_NOMEM;

  194479.           }

  194480.           pFd->pRbu = pDb->pRbu;

  194481.         }

  194482.         pDb->pWalFd = pFd;

  194483.       }

  194484.     }

  194485.   }else{

  194486.     pFd->pRbu = pRbuVfs->pRbu;

  194487.   }

  194488. 

  194489.   if( oflags & SQLITE_OPEN_MAIN_DB 

  194490.    && sqlite3_uri_boolean(zName, "rbu_memory", 0) 

  194491.   ){

  194492.     assert( oflags & SQLITE_OPEN_MAIN_DB );

  194493.     oflags =  SQLITE_OPEN_TEMP_DB | SQLITE_OPEN_READWRITE | SQLITE_OPEN_CREATE |

  194494.               SQLITE_OPEN_EXCLUSIVE | SQLITE_OPEN_DELETEONCLOSE;

  194495.     zOpen = 0;

  194496.   }

  194497. 

  194498.   if( rc==SQLITE_OK ){

  194499.     rc = pRealVfs->xOpen(pRealVfs, zOpen, pFd->pReal, oflags, pOutFlags);

  194500.   }

  194501.   if( pFd->pReal->pMethods ){

  194502.     /* The xOpen() operation has succeeded. Set the sqlite3_file.pMethods

  194503.     ** pointer and, if the file is a main database file, link it into the

  194504.     ** mutex protected linked list of all such files.  */

  194505.     pFile->pMethods = &rbuvfs_io_methods;

  194506.     if( flags & SQLITE_OPEN_MAIN_DB ){

  194507.       rbuMainlistAdd(pFd);

  194508.     }

  194509.   }else{

  194510.     sqlite3_free(pFd->zDel);

  194511.   }

  194512. 

  194513.   return rc;

  194514. }

  194515. 

  194516. /*

  194517. ** Delete the file located at zPath.

  194518. */

  194519. static int rbuVfsDelete(sqlite3_vfs *pVfs, const char *zPath, int dirSync){

  194520.   sqlite3_vfs *pRealVfs = ((rbu_vfs*)pVfs)->pRealVfs;

  194521.   return pRealVfs->xDelete(pRealVfs, zPath, dirSync);

  194522. }

  194523. 

  194524. /*

  194525. ** Test for access permissions. Return true if the requested permission

  194526. ** is available, or false otherwise.

  194527. */

  194528. static int rbuVfsAccess(

  194529.   sqlite3_vfs *pVfs, 

  194530.   const char *zPath, 

  194531.   int flags, 

  194532.   int *pResOut

  194533. ){

  194534.   rbu_vfs *pRbuVfs = (rbu_vfs*)pVfs;

  194535.   sqlite3_vfs *pRealVfs = pRbuVfs->pRealVfs;

  194536.   int rc;

  194537. 

  194538.   rc = pRealVfs->xAccess(pRealVfs, zPath, flags, pResOut);

  194539. 

  194540.   /* If this call is to check if a *-wal file associated with an RBU target

  194541.   ** database connection exists, and the RBU update is in RBU_STAGE_OAL,

  194542.   ** the following special handling is activated:

  194543.   **

  194544.   **   a) if the *-wal file does exist, return SQLITE_CANTOPEN. This

  194545.   **      ensures that the RBU extension never tries to update a database

  194546.   **      in wal mode, even if the first page of the database file has

  194547.   **      been damaged. 

  194548.   **

  194549.   **   b) if the *-wal file does not exist, claim that it does anyway,

  194550.   **      causing SQLite to call xOpen() to open it. This call will also

  194551.   **      be intercepted (see the rbuVfsOpen() function) and the *-oal

  194552.   **      file opened instead.

  194553.   */

  194554.   if( rc==SQLITE_OK && flags==SQLITE_ACCESS_EXISTS ){

  194555.     rbu_file *pDb = rbuFindMaindb(pRbuVfs, zPath, 1);

  194556.     if( pDb && pDb->pRbu->eStage==RBU_STAGE_OAL ){

  194557.       assert( pDb->pRbu );

  194558.       if( *pResOut ){

  194559.         rc = SQLITE_CANTOPEN;

  194560.       }else{

  194561.         sqlite3_int64 sz = 0;

  194562.         rc = rbuVfsFileSize(&pDb->base, &sz);

  194563.         *pResOut = (sz>0);

  194564.       }

  194565.     }

  194566.   }

  194567. 

  194568.   return rc;

  194569. }

  194570. 

  194571. /*

  194572. ** Populate buffer zOut with the full canonical pathname corresponding

  194573. ** to the pathname in zPath. zOut is guaranteed to point to a buffer

  194574. ** of at least (DEVSYM_MAX_PATHNAME+1) bytes.

  194575. */

  194576. static int rbuVfsFullPathname(

  194577.   sqlite3_vfs *pVfs, 

  194578.   const char *zPath, 

  194579.   int nOut, 

  194580.   char *zOut

  194581. ){

  194582.   sqlite3_vfs *pRealVfs = ((rbu_vfs*)pVfs)->pRealVfs;

  194583.   return pRealVfs->xFullPathname(pRealVfs, zPath, nOut, zOut);

  194584. }

  194585. 

  194586. #ifndef SQLITE_OMIT_LOAD_EXTENSION

  194587. /*

  194588. ** Open the dynamic library located at zPath and return a handle.

  194589. */

  194590. static void *rbuVfsDlOpen(sqlite3_vfs *pVfs, const char *zPath){

  194591.   sqlite3_vfs *pRealVfs = ((rbu_vfs*)pVfs)->pRealVfs;

  194592.   return pRealVfs->xDlOpen(pRealVfs, zPath);

  194593. }

  194594. 

  194595. /*

  194596. ** Populate the buffer zErrMsg (size nByte bytes) with a human readable

  194597. ** utf-8 string describing the most recent error encountered associated 

  194598. ** with dynamic libraries.

  194599. */

  194600. static void rbuVfsDlError(sqlite3_vfs *pVfs, int nByte, char *zErrMsg){

  194601.   sqlite3_vfs *pRealVfs = ((rbu_vfs*)pVfs)->pRealVfs;

  194602.   pRealVfs->xDlError(pRealVfs, nByte, zErrMsg);

  194603. }

  194604. 

  194605. /*

  194606. ** Return a pointer to the symbol zSymbol in the dynamic library pHandle.

  194607. */

  194608. static void (*rbuVfsDlSym(

  194609.   sqlite3_vfs *pVfs, 

  194610.   void *pArg, 

  194611.   const char *zSym

  194612. ))(void){

  194613.   sqlite3_vfs *pRealVfs = ((rbu_vfs*)pVfs)->pRealVfs;

  194614.   return pRealVfs->xDlSym(pRealVfs, pArg, zSym);

  194615. }

  194616. 

  194617. /*

  194618. ** Close the dynamic library handle pHandle.

  194619. */

  194620. static void rbuVfsDlClose(sqlite3_vfs *pVfs, void *pHandle){

  194621.   sqlite3_vfs *pRealVfs = ((rbu_vfs*)pVfs)->pRealVfs;

  194622.   pRealVfs->xDlClose(pRealVfs, pHandle);

  194623. }

  194624. #endif /* SQLITE_OMIT_LOAD_EXTENSION */

  194625. 

  194626. /*

  194627. ** Populate the buffer pointed to by zBufOut with nByte bytes of 

  194628. ** random data.

  194629. */

  194630. static int rbuVfsRandomness(sqlite3_vfs *pVfs, int nByte, char *zBufOut){

  194631.   sqlite3_vfs *pRealVfs = ((rbu_vfs*)pVfs)->pRealVfs;

  194632.   return pRealVfs->xRandomness(pRealVfs, nByte, zBufOut);

  194633. }

  194634. 

  194635. /*

  194636. ** Sleep for nMicro microseconds. Return the number of microseconds 

  194637. ** actually slept.

  194638. */

  194639. static int rbuVfsSleep(sqlite3_vfs *pVfs, int nMicro){

  194640.   sqlite3_vfs *pRealVfs = ((rbu_vfs*)pVfs)->pRealVfs;

  194641.   return pRealVfs->xSleep(pRealVfs, nMicro);

  194642. }

  194643. 

  194644. /*

  194645. ** Return the current time as a Julian Day number in *pTimeOut.

  194646. */

  194647. static int rbuVfsCurrentTime(sqlite3_vfs *pVfs, double *pTimeOut){

  194648.   sqlite3_vfs *pRealVfs = ((rbu_vfs*)pVfs)->pRealVfs;

  194649.   return pRealVfs->xCurrentTime(pRealVfs, pTimeOut);

  194650. }

  194651. 

  194652. /*

  194653. ** No-op.

  194654. */

  194655. static int rbuVfsGetLastError(sqlite3_vfs *pVfs, int a, char *b){

  194656.   return 0;

  194657. }

  194658. 

  194659. /*

  194660. ** Deregister and destroy an RBU vfs created by an earlier call to

  194661. ** sqlite3rbu_create_vfs().

  194662. */

  194663. SQLITE_API void sqlite3rbu_destroy_vfs(const char *zName){

  194664.   sqlite3_vfs *pVfs = sqlite3_vfs_find(zName);

  194665.   if( pVfs && pVfs->xOpen==rbuVfsOpen ){

  194666.     sqlite3_mutex_free(((rbu_vfs*)pVfs)->mutex);

  194667.     sqlite3_vfs_unregister(pVfs);

  194668.     sqlite3_free(pVfs);

  194669.   }

  194670. }

  194671. 

  194672. /*

  194673. ** Create an RBU VFS named zName that accesses the underlying file-system

  194674. ** via existing VFS zParent. The new object is registered as a non-default

  194675. ** VFS with SQLite before returning.

  194676. */

  194677. SQLITE_API int sqlite3rbu_create_vfs(const char *zName, const char *zParent){

  194678. 

  194679.   /* Template for VFS */

  194680.   static sqlite3_vfs vfs_template = {

  194681.     1,                            /* iVersion */

  194682.     0,                            /* szOsFile */

  194683.     0,                            /* mxPathname */

  194684.     0,                            /* pNext */

  194685.     0,                            /* zName */

  194686.     0,                            /* pAppData */

  194687.     rbuVfsOpen,                   /* xOpen */

  194688.     rbuVfsDelete,                 /* xDelete */

  194689.     rbuVfsAccess,                 /* xAccess */

  194690.     rbuVfsFullPathname,           /* xFullPathname */

  194691. 

  194692. #ifndef SQLITE_OMIT_LOAD_EXTENSION

  194693.     rbuVfsDlOpen,                 /* xDlOpen */

  194694.     rbuVfsDlError,                /* xDlError */

  194695.     rbuVfsDlSym,                  /* xDlSym */

  194696.     rbuVfsDlClose,                /* xDlClose */

  194697. #else

  194698.     0, 0, 0, 0,

  194699. #endif

  194700. 

  194701.     rbuVfsRandomness,             /* xRandomness */

  194702.     rbuVfsSleep,                  /* xSleep */

  194703.     rbuVfsCurrentTime,            /* xCurrentTime */

  194704.     rbuVfsGetLastError,           /* xGetLastError */

  194705.     0,                            /* xCurrentTimeInt64 (version 2) */

  194706.     0, 0, 0                       /* Unimplemented version 3 methods */

  194707.   };

  194708. 

  194709.   rbu_vfs *pNew = 0;              /* Newly allocated VFS */

  194710.   int rc = SQLITE_OK;

  194711.   size_t nName;

  194712.   size_t nByte;

  194713. 

  194714.   nName = strlen(zName);

  194715.   nByte = sizeof(rbu_vfs) + nName + 1;

  194716.   pNew = (rbu_vfs*)sqlite3_malloc64(nByte);

  194717.   if( pNew==0 ){

  194718.     rc = SQLITE_NOMEM;

  194719.   }else{

  194720.     sqlite3_vfs *pParent;           /* Parent VFS */

  194721.     memset(pNew, 0, nByte);

  194722.     pParent = sqlite3_vfs_find(zParent);

  194723.     if( pParent==0 ){

  194724.       rc = SQLITE_NOTFOUND;

  194725.     }else{

  194726.       char *zSpace;

  194727.       memcpy(&pNew->base, &vfs_template, sizeof(sqlite3_vfs));

  194728.       pNew->base.mxPathname = pParent->mxPathname;

  194729.       pNew->base.szOsFile = sizeof(rbu_file) + pParent->szOsFile;

  194730.       pNew->pRealVfs = pParent;

  194731.       pNew->base.zName = (const char*)(zSpace = (char*)&pNew[1]);

  194732.       memcpy(zSpace, zName, nName);

  194733. 

  194734.       /* Allocate the mutex and register the new VFS (not as the default) */

  194735.       pNew->mutex = sqlite3_mutex_alloc(SQLITE_MUTEX_RECURSIVE);

  194736.       if( pNew->mutex==0 ){

  194737.         rc = SQLITE_NOMEM;

  194738.       }else{

  194739.         rc = sqlite3_vfs_register(&pNew->base, 0);

  194740.       }

  194741.     }

  194742. 

  194743.     if( rc!=SQLITE_OK ){

  194744.       sqlite3_mutex_free(pNew->mutex);

  194745.       sqlite3_free(pNew);

  194746.     }

  194747.   }

  194748. 

  194749.   return rc;

  194750. }

  194751. 

  194752. /*

  194753. ** Configure the aggregate temp file size limit for this RBU handle.

  194754. */

  194755. SQLITE_API sqlite3_int64 sqlite3rbu_temp_size_limit(sqlite3rbu *pRbu, sqlite3_int64 n){

  194756.   if( n>=0 ){

  194757.     pRbu->szTempLimit = n;

  194758.   }

  194759.   return pRbu->szTempLimit;

  194760. }

  194761. 

  194762. SQLITE_API sqlite3_int64 sqlite3rbu_temp_size(sqlite3rbu *pRbu){

  194763.   return pRbu->szTemp;

  194764. }

  194765. 

  194766. 

  194767. /**************************************************************************/

  194768. 

  194769. #endif /* !defined(SQLITE_CORE) || defined(SQLITE_ENABLE_RBU) */

  194770. 

  194771. /************** End of sqlite3rbu.c ******************************************/

  194772. /************** Begin file dbstat.c ******************************************/

  194773. /*

  194774. ** 2010 July 12

  194775. **

  194776. ** The author disclaims copyright to this source code.  In place of

  194777. ** a legal notice, here is a blessing:

  194778. **

  194779. **    May you do good and not evil.

  194780. **    May you find forgiveness for yourself and forgive others.

  194781. **    May you share freely, never taking more than you give.

  194782. **

  194783. ******************************************************************************

  194784. **

  194785. ** This file contains an implementation of the "dbstat" virtual table.

  194786. **

  194787. ** The dbstat virtual table is used to extract low-level formatting

  194788. ** information from an SQLite database in order to implement the

  194789. ** "sqlite3_analyzer" utility.  See the ../tool/spaceanal.tcl script

  194790. ** for an example implementation.

  194791. **

  194792. ** Additional information is available on the "dbstat.html" page of the

  194793. ** official SQLite documentation.

  194794. */

  194795. 

  194796. /* #include "sqliteInt.h"   ** Requires access to internal data structures ** */

  194797. #if (defined(SQLITE_ENABLE_DBSTAT_VTAB) || defined(SQLITE_TEST)) \

  194798.     && !defined(SQLITE_OMIT_VIRTUALTABLE)

  194799. 

  194800. /*

  194801. ** Page paths:

  194802. ** 

  194803. **   The value of the 'path' column describes the path taken from the 

  194804. **   root-node of the b-tree structure to each page. The value of the 

  194805. **   root-node path is '/'.

  194806. **

  194807. **   The value of the path for the left-most child page of the root of

  194808. **   a b-tree is '/000/'. (Btrees store content ordered from left to right

  194809. **   so the pages to the left have smaller keys than the pages to the right.)

  194810. **   The next to left-most child of the root page is

  194811. **   '/001', and so on, each sibling page identified by a 3-digit hex 

  194812. **   value. The children of the 451st left-most sibling have paths such

  194813. **   as '/1c2/000/, '/1c2/001/' etc.

  194814. **

  194815. **   Overflow pages are specified by appending a '+' character and a 

  194816. **   six-digit hexadecimal value to the path to the cell they are linked

  194817. **   from. For example, the three overflow pages in a chain linked from 

  194818. **   the left-most cell of the 450th child of the root page are identified

  194819. **   by the paths:

  194820. **

  194821. **      '/1c2/000+000000'         // First page in overflow chain

  194822. **      '/1c2/000+000001'         // Second page in overflow chain

  194823. **      '/1c2/000+000002'         // Third page in overflow chain

  194824. **

  194825. **   If the paths are sorted using the BINARY collation sequence, then

  194826. **   the overflow pages associated with a cell will appear earlier in the

  194827. **   sort-order than its child page:

  194828. **

  194829. **      '/1c2/000/'               // Left-most child of 451st child of root

  194830. */

  194831. #define VTAB_SCHEMA                                                         \

  194832.   "CREATE TABLE xx( "                                                       \

  194833.   "  name       TEXT,             /* Name of table or index */"             \

  194834.   "  path       TEXT,             /* Path to page from root */"             \

  194835.   "  pageno     INTEGER,          /* Page number */"                        \

  194836.   "  pagetype   TEXT,             /* 'internal', 'leaf' or 'overflow' */"   \

  194837.   "  ncell      INTEGER,          /* Cells on page (0 for overflow) */"     \

  194838.   "  payload    INTEGER,          /* Bytes of payload on this page */"      \

  194839.   "  unused     INTEGER,          /* Bytes of unused space on this page */" \

  194840.   "  mx_payload INTEGER,          /* Largest payload size of all cells */"  \

  194841.   "  pgoffset   INTEGER,          /* Offset of page in file */"             \

  194842.   "  pgsize     INTEGER,          /* Size of the page */"                   \

  194843.   "  schema     TEXT HIDDEN       /* Database schema being analyzed */"     \

  194844.   ");"

  194845. 

  194846. 

  194847. typedef struct StatTable StatTable;

  194848. typedef struct StatCursor StatCursor;

  194849. typedef struct StatPage StatPage;

  194850. typedef struct StatCell StatCell;

  194851. 

  194852. struct StatCell {

  194853.   int nLocal;                     /* Bytes of local payload */

  194854.   u32 iChildPg;                   /* Child node (or 0 if this is a leaf) */

  194855.   int nOvfl;                      /* Entries in aOvfl[] */

  194856.   u32 *aOvfl;                     /* Array of overflow page numbers */

  194857.   int nLastOvfl;                  /* Bytes of payload on final overflow page */

  194858.   int iOvfl;                      /* Iterates through aOvfl[] */

  194859. };

  194860. 

  194861. struct StatPage {

  194862.   u32 iPgno;

  194863.   DbPage *pPg;

  194864.   int iCell;

  194865. 

  194866.   char *zPath;                    /* Path to this page */

  194867. 

  194868.   /* Variables populated by statDecodePage(): */

  194869.   u8 flags;                       /* Copy of flags byte */

  194870.   int nCell;                      /* Number of cells on page */

  194871.   int nUnused;                    /* Number of unused bytes on page */

  194872.   StatCell *aCell;                /* Array of parsed cells */

  194873.   u32 iRightChildPg;              /* Right-child page number (or 0) */

  194874.   int nMxPayload;                 /* Largest payload of any cell on this page */

  194875. };

  194876. 

  194877. struct StatCursor {

  194878.   sqlite3_vtab_cursor base;

  194879.   sqlite3_stmt *pStmt;            /* Iterates through set of root pages */

  194880.   int isEof;                      /* After pStmt has returned SQLITE_DONE */

  194881.   int iDb;                        /* Schema used for this query */

  194882. 

  194883.   StatPage aPage[32];

  194884.   int iPage;                      /* Current entry in aPage[] */

  194885. 

  194886.   /* Values to return. */

  194887.   char *zName;                    /* Value of 'name' column */

  194888.   char *zPath;                    /* Value of 'path' column */

  194889.   u32 iPageno;                    /* Value of 'pageno' column */

  194890.   char *zPagetype;                /* Value of 'pagetype' column */

  194891.   int nCell;                      /* Value of 'ncell' column */

  194892.   int nPayload;                   /* Value of 'payload' column */

  194893.   int nUnused;                    /* Value of 'unused' column */

  194894.   int nMxPayload;                 /* Value of 'mx_payload' column */

  194895.   i64 iOffset;                    /* Value of 'pgOffset' column */

  194896.   int szPage;                     /* Value of 'pgSize' column */

  194897. };

  194898. 

  194899. struct StatTable {

  194900.   sqlite3_vtab base;

  194901.   sqlite3 *db;

  194902.   int iDb;                        /* Index of database to analyze */

  194903. };

  194904. 

  194905. #ifndef get2byte

  194906. # define get2byte(x)   ((x)[0]<<8 | (x)[1])

  194907. #endif

  194908. 

  194909. /*

  194910. ** Connect to or create a statvfs virtual table.

  194911. */

  194912. static int statConnect(

  194913.   sqlite3 *db,

  194914.   void *pAux,

  194915.   int argc, const char *const*argv,

  194916.   sqlite3_vtab **ppVtab,

  194917.   char **pzErr

  194918. ){

  194919.   StatTable *pTab = 0;

  194920.   int rc = SQLITE_OK;

  194921.   int iDb;

  194922. 

  194923.   if( argc>=4 ){

  194924.     Token nm;

  194925.     sqlite3TokenInit(&nm, (char*)argv[3]);

  194926.     iDb = sqlite3FindDb(db, &nm);

  194927.     if( iDb<0 ){

  194928.       *pzErr = sqlite3_mprintf("no such database: %s", argv[3]);

  194929.       return SQLITE_ERROR;

  194930.     }

  194931.   }else{

  194932.     iDb = 0;

  194933.   }

  194934.   rc = sqlite3_declare_vtab(db, VTAB_SCHEMA);

  194935.   if( rc==SQLITE_OK ){

  194936.     pTab = (StatTable *)sqlite3_malloc64(sizeof(StatTable));

  194937.     if( pTab==0 ) rc = SQLITE_NOMEM_BKPT;

  194938.   }

  194939. 

  194940.   assert( rc==SQLITE_OK || pTab==0 );

  194941.   if( rc==SQLITE_OK ){

  194942.     memset(pTab, 0, sizeof(StatTable));

  194943.     pTab->db = db;

  194944.     pTab->iDb = iDb;

  194945.   }

  194946. 

  194947.   *ppVtab = (sqlite3_vtab*)pTab;

  194948.   return rc;

  194949. }

  194950. 

  194951. /*

  194952. ** Disconnect from or destroy a statvfs virtual table.

  194953. */

  194954. static int statDisconnect(sqlite3_vtab *pVtab){

  194955.   sqlite3_free(pVtab);

  194956.   return SQLITE_OK;

  194957. }

  194958. 

  194959. /*

  194960. ** There is no "best-index". This virtual table always does a linear

  194961. ** scan.  However, a schema=? constraint should cause this table to

  194962. ** operate on a different database schema, so check for it.

  194963. **

  194964. ** idxNum is normally 0, but will be 1 if a schema=? constraint exists.

  194965. */

  194966. static int statBestIndex(sqlite3_vtab *tab, sqlite3_index_info *pIdxInfo){

  194967.   int i;

  194968. 

  194969.   /* Look for a valid schema=? constraint.  If found, change the idxNum to

  194970.   ** 1 and request the value of that constraint be sent to xFilter.  And

  194971.   ** lower the cost estimate to encourage the constrained version to be

  194972.   ** used.

  194973.   */

  194974.   for(i=0; i<pIdxInfo->nConstraint; i++){

  194975.     if( pIdxInfo->aConstraint[i].iColumn!=10 ) continue;

  194976.     if( pIdxInfo->aConstraint[i].usable==0 ) return SQLITE_CONSTRAINT;

  194977.     if( pIdxInfo->aConstraint[i].op!=SQLITE_INDEX_CONSTRAINT_EQ ) continue;

  194978.     pIdxInfo->idxNum = 1;

  194979.     pIdxInfo->estimatedCost = 1.0;

  194980.     pIdxInfo->aConstraintUsage[i].argvIndex = 1;

  194981.     pIdxInfo->aConstraintUsage[i].omit = 1;

  194982.     break;

  194983.   }

  194984. 

  194985. 

  194986.   /* Records are always returned in ascending order of (name, path). 

  194987.   ** If this will satisfy the client, set the orderByConsumed flag so that 

  194988.   ** SQLite does not do an external sort.

  194989.   */

  194990.   if( ( pIdxInfo->nOrderBy==1

  194991.      && pIdxInfo->aOrderBy[0].iColumn==0

  194992.      && pIdxInfo->aOrderBy[0].desc==0

  194993.      ) ||

  194994.       ( pIdxInfo->nOrderBy==2

  194995.      && pIdxInfo->aOrderBy[0].iColumn==0

  194996.      && pIdxInfo->aOrderBy[0].desc==0

  194997.      && pIdxInfo->aOrderBy[1].iColumn==1

  194998.      && pIdxInfo->aOrderBy[1].desc==0

  194999.      )

  195000.   ){

  195001.     pIdxInfo->orderByConsumed = 1;

  195002.   }

  195003. 

  195004.   return SQLITE_OK;

  195005. }

  195006. 

  195007. /*

  195008. ** Open a new statvfs cursor.

  195009. */

  195010. static int statOpen(sqlite3_vtab *pVTab, sqlite3_vtab_cursor **ppCursor){

  195011.   StatTable *pTab = (StatTable *)pVTab;

  195012.   StatCursor *pCsr;

  195013. 

  195014.   pCsr = (StatCursor *)sqlite3_malloc64(sizeof(StatCursor));

  195015.   if( pCsr==0 ){

  195016.     return SQLITE_NOMEM_BKPT;

  195017.   }else{

  195018.     memset(pCsr, 0, sizeof(StatCursor));

  195019.     pCsr->base.pVtab = pVTab;

  195020.     pCsr->iDb = pTab->iDb;

  195021.   }

  195022. 

  195023.   *ppCursor = (sqlite3_vtab_cursor *)pCsr;

  195024.   return SQLITE_OK;

  195025. }

  195026. 

  195027. static void statClearCells(StatPage *p){

  195028.   int i;

  195029.   if( p->aCell ){

  195030.     for(i=0; i<p->nCell; i++){

  195031.       sqlite3_free(p->aCell[i].aOvfl);

  195032.     }

  195033.     sqlite3_free(p->aCell);

  195034.   }

  195035.   p->nCell = 0;

  195036.   p->aCell = 0;

  195037. }

  195038. 

  195039. static void statClearPage(StatPage *p){

  195040.   statClearCells(p);

  195041.   sqlite3PagerUnref(p->pPg);

  195042.   sqlite3_free(p->zPath);

  195043.   memset(p, 0, sizeof(StatPage));

  195044. }

  195045. 

  195046. static void statResetCsr(StatCursor *pCsr){

  195047.   int i;

  195048.   sqlite3_reset(pCsr->pStmt);

  195049.   for(i=0; i<ArraySize(pCsr->aPage); i++){

  195050.     statClearPage(&pCsr->aPage[i]);

  195051.   }

  195052.   pCsr->iPage = 0;

  195053.   sqlite3_free(pCsr->zPath);

  195054.   pCsr->zPath = 0;

  195055.   pCsr->isEof = 0;

  195056. }

  195057. 

  195058. /*

  195059. ** Close a statvfs cursor.

  195060. */

  195061. static int statClose(sqlite3_vtab_cursor *pCursor){

  195062.   StatCursor *pCsr = (StatCursor *)pCursor;

  195063.   statResetCsr(pCsr);

  195064.   sqlite3_finalize(pCsr->pStmt);

  195065.   sqlite3_free(pCsr);

  195066.   return SQLITE_OK;

  195067. }

  195068. 

  195069. static void getLocalPayload(

  195070.   int nUsable,                    /* Usable bytes per page */

  195071.   u8 flags,                       /* Page flags */

  195072.   int nTotal,                     /* Total record (payload) size */

  195073.   int *pnLocal                    /* OUT: Bytes stored locally */

  195074. ){

  195075.   int nLocal;

  195076.   int nMinLocal;

  195077.   int nMaxLocal;

  195078.  

  195079.   if( flags==0x0D ){              /* Table leaf node */

  195080.     nMinLocal = (nUsable - 12) * 32 / 255 - 23;

  195081.     nMaxLocal = nUsable - 35;

  195082.   }else{                          /* Index interior and leaf nodes */

  195083.     nMinLocal = (nUsable - 12) * 32 / 255 - 23;

  195084.     nMaxLocal = (nUsable - 12) * 64 / 255 - 23;

  195085.   }

  195086. 

  195087.   nLocal = nMinLocal + (nTotal - nMinLocal) % (nUsable - 4);

  195088.   if( nLocal>nMaxLocal ) nLocal = nMinLocal;

  195089.   *pnLocal = nLocal;

  195090. }

  195091. 

  195092. static int statDecodePage(Btree *pBt, StatPage *p){

  195093.   int nUnused;

  195094.   int iOff;

  195095.   int nHdr;

  195096.   int isLeaf;

  195097.   int szPage;

  195098. 

  195099.   u8 *aData = sqlite3PagerGetData(p->pPg);

  195100.   u8 *aHdr = &aData[p->iPgno==1 ? 100 : 0];

  195101. 

  195102.   p->flags = aHdr[0];

  195103.   if( p->flags==0x0A || p->flags==0x0D ){

  195104.     isLeaf = 1;

  195105.     nHdr = 8;

  195106.   }else if( p->flags==0x05 || p->flags==0x02 ){

  195107.     isLeaf = 0;

  195108.     nHdr = 12;

  195109.   }else{

  195110.     goto statPageIsCorrupt;

  195111.   }

  195112.   if( p->iPgno==1 ) nHdr += 100;

  195113.   p->nCell = get2byte(&aHdr[3]);

  195114.   p->nMxPayload = 0;

  195115.   szPage = sqlite3BtreeGetPageSize(pBt);

  195116. 

  195117.   nUnused = get2byte(&aHdr[5]) - nHdr - 2*p->nCell;

  195118.   nUnused += (int)aHdr[7];

  195119.   iOff = get2byte(&aHdr[1]);

  195120.   while( iOff ){

  195121.     int iNext;

  195122.     if( iOff>=szPage ) goto statPageIsCorrupt;

  195123.     nUnused += get2byte(&aData[iOff+2]);

  195124.     iNext = get2byte(&aData[iOff]);

  195125.     if( iNext<iOff+4 && iNext>0 ) goto statPageIsCorrupt;

  195126.     iOff = iNext;

  195127.   }

  195128.   p->nUnused = nUnused;

  195129.   p->iRightChildPg = isLeaf ? 0 : sqlite3Get4byte(&aHdr[8]);

  195130. 

  195131.   if( p->nCell ){

  195132.     int i;                        /* Used to iterate through cells */

  195133.     int nUsable;                  /* Usable bytes per page */

  195134. 

  195135.     sqlite3BtreeEnter(pBt);

  195136.     nUsable = szPage - sqlite3BtreeGetReserveNoMutex(pBt);

  195137.     sqlite3BtreeLeave(pBt);

  195138.     p->aCell = sqlite3_malloc64((p->nCell+1) * sizeof(StatCell));

  195139.     if( p->aCell==0 ) return SQLITE_NOMEM_BKPT;

  195140.     memset(p->aCell, 0, (p->nCell+1) * sizeof(StatCell));

  195141. 

  195142.     for(i=0; i<p->nCell; i++){

  195143.       StatCell *pCell = &p->aCell[i];

  195144. 

  195145.       iOff = get2byte(&aData[nHdr+i*2]);

  195146.       if( iOff<nHdr || iOff>=szPage ) goto statPageIsCorrupt;

  195147.       if( !isLeaf ){

  195148.         pCell->iChildPg = sqlite3Get4byte(&aData[iOff]);

  195149.         iOff += 4;

  195150.       }

  195151.       if( p->flags==0x05 ){

  195152.         /* A table interior node. nPayload==0. */

  195153.       }else{

  195154.         u32 nPayload;             /* Bytes of payload total (local+overflow) */

  195155.         int nLocal;               /* Bytes of payload stored locally */

  195156.         iOff += getVarint32(&aData[iOff], nPayload);

  195157.         if( p->flags==0x0D ){

  195158.           u64 dummy;

  195159.           iOff += sqlite3GetVarint(&aData[iOff], &dummy);

  195160.         }

  195161.         if( nPayload>(u32)p->nMxPayload ) p->nMxPayload = nPayload;

  195162.         getLocalPayload(nUsable, p->flags, nPayload, &nLocal);

  195163.         if( nLocal<0 ) goto statPageIsCorrupt;

  195164.         pCell->nLocal = nLocal;

  195165.         assert( nPayload>=(u32)nLocal );

  195166.         assert( nLocal<=(nUsable-35) );

  195167.         if( nPayload>(u32)nLocal ){

  195168.           int j;

  195169.           int nOvfl = ((nPayload - nLocal) + nUsable-4 - 1) / (nUsable - 4);

  195170.           if( iOff+nLocal>nUsable ) goto statPageIsCorrupt;

  195171.           pCell->nLastOvfl = (nPayload-nLocal) - (nOvfl-1) * (nUsable-4);

  195172.           pCell->nOvfl = nOvfl;

  195173.           pCell->aOvfl = sqlite3_malloc64(sizeof(u32)*nOvfl);

  195174.           if( pCell->aOvfl==0 ) return SQLITE_NOMEM_BKPT;

  195175.           pCell->aOvfl[0] = sqlite3Get4byte(&aData[iOff+nLocal]);

  195176.           for(j=1; j<nOvfl; j++){

  195177.             int rc;

  195178.             u32 iPrev = pCell->aOvfl[j-1];

  195179.             DbPage *pPg = 0;

  195180.             rc = sqlite3PagerGet(sqlite3BtreePager(pBt), iPrev, &pPg, 0);

  195181.             if( rc!=SQLITE_OK ){

  195182.               assert( pPg==0 );

  195183.               return rc;

  195184.             } 

  195185.             pCell->aOvfl[j] = sqlite3Get4byte(sqlite3PagerGetData(pPg));

  195186.             sqlite3PagerUnref(pPg);

  195187.           }

  195188.         }

  195189.       }

  195190.     }

  195191.   }

  195192. 

  195193.   return SQLITE_OK;

  195194. 

  195195. statPageIsCorrupt:

  195196.   p->flags = 0;

  195197.   statClearCells(p);

  195198.   return SQLITE_OK;

  195199. }

  195200. 

  195201. /*

  195202. ** Populate the pCsr->iOffset and pCsr->szPage member variables. Based on

  195203. ** the current value of pCsr->iPageno.

  195204. */

  195205. static void statSizeAndOffset(StatCursor *pCsr){

  195206.   StatTable *pTab = (StatTable *)((sqlite3_vtab_cursor *)pCsr)->pVtab;

  195207.   Btree *pBt = pTab->db->aDb[pTab->iDb].pBt;

  195208.   Pager *pPager = sqlite3BtreePager(pBt);

  195209.   sqlite3_file *fd;

  195210.   sqlite3_int64 x[2];

  195211. 

  195212.   /* The default page size and offset */

  195213.   pCsr->szPage = sqlite3BtreeGetPageSize(pBt);

  195214.   pCsr->iOffset = (i64)pCsr->szPage * (pCsr->iPageno - 1);

  195215. 

  195216.   /* If connected to a ZIPVFS backend, override the page size and

  195217.   ** offset with actual values obtained from ZIPVFS.

  195218.   */

  195219.   fd = sqlite3PagerFile(pPager);

  195220.   x[0] = pCsr->iPageno;

  195221.   if( sqlite3OsFileControl(fd, 230440, &x)==SQLITE_OK ){

  195222.     pCsr->iOffset = x[0];

  195223.     pCsr->szPage = (int)x[1];

  195224.   }

  195225. }

  195226. 

  195227. /*

  195228. ** Move a statvfs cursor to the next entry in the file.

  195229. */

  195230. static int statNext(sqlite3_vtab_cursor *pCursor){

  195231.   int rc;

  195232.   int nPayload;

  195233.   char *z;

  195234.   StatCursor *pCsr = (StatCursor *)pCursor;

  195235.   StatTable *pTab = (StatTable *)pCursor->pVtab;

  195236.   Btree *pBt = pTab->db->aDb[pCsr->iDb].pBt;

  195237.   Pager *pPager = sqlite3BtreePager(pBt);

  195238. 

  195239.   sqlite3_free(pCsr->zPath);

  195240.   pCsr->zPath = 0;

  195241. 

  195242. statNextRestart:

  195243.   if( pCsr->aPage[0].pPg==0 ){

  195244.     rc = sqlite3_step(pCsr->pStmt);

  195245.     if( rc==SQLITE_ROW ){

  195246.       int nPage;

  195247.       u32 iRoot = (u32)sqlite3_column_int64(pCsr->pStmt, 1);

  195248.       sqlite3PagerPagecount(pPager, &nPage);

  195249.       if( nPage==0 ){

  195250.         pCsr->isEof = 1;

  195251.         return sqlite3_reset(pCsr->pStmt);

  195252.       }

  195253.       rc = sqlite3PagerGet(pPager, iRoot, &pCsr->aPage[0].pPg, 0);

  195254.       pCsr->aPage[0].iPgno = iRoot;

  195255.       pCsr->aPage[0].iCell = 0;

  195256.       pCsr->aPage[0].zPath = z = sqlite3_mprintf("/");

  195257.       pCsr->iPage = 0;

  195258.       if( z==0 ) rc = SQLITE_NOMEM_BKPT;

  195259.     }else{

  195260.       pCsr->isEof = 1;

  195261.       return sqlite3_reset(pCsr->pStmt);

  195262.     }

  195263.   }else{

  195264. 

  195265.     /* Page p itself has already been visited. */

  195266.     StatPage *p = &pCsr->aPage[pCsr->iPage];

  195267. 

  195268.     while( p->iCell<p->nCell ){

  195269.       StatCell *pCell = &p->aCell[p->iCell];

  195270.       if( pCell->iOvfl<pCell->nOvfl ){

  195271.         int nUsable;

  195272.         sqlite3BtreeEnter(pBt);

  195273.         nUsable = sqlite3BtreeGetPageSize(pBt) - 

  195274.                         sqlite3BtreeGetReserveNoMutex(pBt);

  195275.         sqlite3BtreeLeave(pBt);

  195276.         pCsr->zName = (char *)sqlite3_column_text(pCsr->pStmt, 0);

  195277.         pCsr->iPageno = pCell->aOvfl[pCell->iOvfl];

  195278.         pCsr->zPagetype = "overflow";

  195279.         pCsr->nCell = 0;

  195280.         pCsr->nMxPayload = 0;

  195281.         pCsr->zPath = z = sqlite3_mprintf(

  195282.             "%s%.3x+%.6x", p->zPath, p->iCell, pCell->iOvfl

  195283.         );

  195284.         if( pCell->iOvfl<pCell->nOvfl-1 ){

  195285.           pCsr->nUnused = 0;

  195286.           pCsr->nPayload = nUsable - 4;

  195287.         }else{

  195288.           pCsr->nPayload = pCell->nLastOvfl;

  195289.           pCsr->nUnused = nUsable - 4 - pCsr->nPayload;

  195290.         }

  195291.         pCell->iOvfl++;

  195292.         statSizeAndOffset(pCsr);

  195293.         return z==0 ? SQLITE_NOMEM_BKPT : SQLITE_OK;

  195294.       }

  195295.       if( p->iRightChildPg ) break;

  195296.       p->iCell++;

  195297.     }

  195298. 

  195299.     if( !p->iRightChildPg || p->iCell>p->nCell ){

  195300.       statClearPage(p);

  195301.       if( pCsr->iPage==0 ) return statNext(pCursor);

  195302.       pCsr->iPage--;

  195303.       goto statNextRestart; /* Tail recursion */

  195304.     }

  195305.     pCsr->iPage++;

  195306.     if( pCsr->iPage>=ArraySize(pCsr->aPage) ){

  195307.       statResetCsr(pCsr);

  195308.       return SQLITE_CORRUPT_BKPT;

  195309.     }

  195310.     assert( p==&pCsr->aPage[pCsr->iPage-1] );

  195311. 

  195312.     if( p->iCell==p->nCell ){

  195313.       p[1].iPgno = p->iRightChildPg;

  195314.     }else{

  195315.       p[1].iPgno = p->aCell[p->iCell].iChildPg;

  195316.     }

  195317.     rc = sqlite3PagerGet(pPager, p[1].iPgno, &p[1].pPg, 0);

  195318.     p[1].iCell = 0;

  195319.     p[1].zPath = z = sqlite3_mprintf("%s%.3x/", p->zPath, p->iCell);

  195320.     p->iCell++;

  195321.     if( z==0 ) rc = SQLITE_NOMEM_BKPT;

  195322.   }

  195323. 

  195324. 

  195325.   /* Populate the StatCursor fields with the values to be returned

  195326.   ** by the xColumn() and xRowid() methods.

  195327.   */

  195328.   if( rc==SQLITE_OK ){

  195329.     int i;

  195330.     StatPage *p = &pCsr->aPage[pCsr->iPage];

  195331.     pCsr->zName = (char *)sqlite3_column_text(pCsr->pStmt, 0);

  195332.     pCsr->iPageno = p->iPgno;

  195333. 

  195334.     rc = statDecodePage(pBt, p);

  195335.     if( rc==SQLITE_OK ){

  195336.       statSizeAndOffset(pCsr);

  195337. 

  195338.       switch( p->flags ){

  195339.         case 0x05:             /* table internal */

  195340.         case 0x02:             /* index internal */

  195341.           pCsr->zPagetype = "internal";

  195342.           break;

  195343.         case 0x0D:             /* table leaf */

  195344.         case 0x0A:             /* index leaf */

  195345.           pCsr->zPagetype = "leaf";

  195346.           break;

  195347.         default:

  195348.           pCsr->zPagetype = "corrupted";

  195349.           break;

  195350.       }

  195351.       pCsr->nCell = p->nCell;

  195352.       pCsr->nUnused = p->nUnused;

  195353.       pCsr->nMxPayload = p->nMxPayload;

  195354.       pCsr->zPath = z = sqlite3_mprintf("%s", p->zPath);

  195355.       if( z==0 ) rc = SQLITE_NOMEM_BKPT;

  195356.       nPayload = 0;

  195357.       for(i=0; i<p->nCell; i++){

  195358.         nPayload += p->aCell[i].nLocal;

  195359.       }

  195360.       pCsr->nPayload = nPayload;

  195361.     }

  195362.   }

  195363. 

  195364.   return rc;

  195365. }

  195366. 

  195367. static int statEof(sqlite3_vtab_cursor *pCursor){

  195368.   StatCursor *pCsr = (StatCursor *)pCursor;

  195369.   return pCsr->isEof;

  195370. }

  195371. 

  195372. static int statFilter(

  195373.   sqlite3_vtab_cursor *pCursor, 

  195374.   int idxNum, const char *idxStr,

  195375.   int argc, sqlite3_value **argv

  195376. ){

  195377.   StatCursor *pCsr = (StatCursor *)pCursor;

  195378.   StatTable *pTab = (StatTable*)(pCursor->pVtab);

  195379.   char *zSql;

  195380.   int rc = SQLITE_OK;

  195381. 

  195382.   if( idxNum==1 ){

  195383.     const char *zDbase = (const char*)sqlite3_value_text(argv[0]);

  195384.     pCsr->iDb = sqlite3FindDbName(pTab->db, zDbase);

  195385.     if( pCsr->iDb<0 ){

  195386.       sqlite3_free(pCursor->pVtab->zErrMsg);

  195387.       pCursor->pVtab->zErrMsg = sqlite3_mprintf("no such schema: %s", zDbase);

  195388.       return pCursor->pVtab->zErrMsg ? SQLITE_ERROR : SQLITE_NOMEM_BKPT;

  195389.     }

  195390.   }else{

  195391.     pCsr->iDb = pTab->iDb;

  195392.   }

  195393.   statResetCsr(pCsr);

  195394.   sqlite3_finalize(pCsr->pStmt);

  195395.   pCsr->pStmt = 0;

  195396.   zSql = sqlite3_mprintf(

  195397.       "SELECT 'sqlite_master' AS name, 1 AS rootpage, 'table' AS type"

  195398.       "  UNION ALL  "

  195399.       "SELECT name, rootpage, type"

  195400.       "  FROM \"%w\".sqlite_master WHERE rootpage!=0"

  195401.       "  ORDER BY name", pTab->db->aDb[pCsr->iDb].zDbSName);

  195402.   if( zSql==0 ){

  195403.     return SQLITE_NOMEM_BKPT;

  195404.   }else{

  195405.     rc = sqlite3_prepare_v2(pTab->db, zSql, -1, &pCsr->pStmt, 0);

  195406.     sqlite3_free(zSql);

  195407.   }

  195408. 

  195409.   if( rc==SQLITE_OK ){

  195410.     rc = statNext(pCursor);

  195411.   }

  195412.   return rc;

  195413. }

  195414. 

  195415. static int statColumn(

  195416.   sqlite3_vtab_cursor *pCursor, 

  195417.   sqlite3_context *ctx, 

  195418.   int i

  195419. ){

  195420.   StatCursor *pCsr = (StatCursor *)pCursor;

  195421.   switch( i ){

  195422.     case 0:            /* name */

  195423.       sqlite3_result_text(ctx, pCsr->zName, -1, SQLITE_TRANSIENT);

  195424.       break;

  195425.     case 1:            /* path */

  195426.       sqlite3_result_text(ctx, pCsr->zPath, -1, SQLITE_TRANSIENT);

  195427.       break;

  195428.     case 2:            /* pageno */

  195429.       sqlite3_result_int64(ctx, pCsr->iPageno);

  195430.       break;

  195431.     case 3:            /* pagetype */

  195432.       sqlite3_result_text(ctx, pCsr->zPagetype, -1, SQLITE_STATIC);

  195433.       break;

  195434.     case 4:            /* ncell */

  195435.       sqlite3_result_int(ctx, pCsr->nCell);

  195436.       break;

  195437.     case 5:            /* payload */

  195438.       sqlite3_result_int(ctx, pCsr->nPayload);

  195439.       break;

  195440.     case 6:            /* unused */

  195441.       sqlite3_result_int(ctx, pCsr->nUnused);

  195442.       break;

  195443.     case 7:            /* mx_payload */

  195444.       sqlite3_result_int(ctx, pCsr->nMxPayload);

  195445.       break;

  195446.     case 8:            /* pgoffset */

  195447.       sqlite3_result_int64(ctx, pCsr->iOffset);

  195448.       break;

  195449.     case 9:            /* pgsize */

  195450.       sqlite3_result_int(ctx, pCsr->szPage);

  195451.       break;

  195452.     default: {          /* schema */

  195453.       sqlite3 *db = sqlite3_context_db_handle(ctx);

  195454.       int iDb = pCsr->iDb;

  195455.       sqlite3_result_text(ctx, db->aDb[iDb].zDbSName, -1, SQLITE_STATIC);

  195456.       break;

  195457.     }

  195458.   }

  195459.   return SQLITE_OK;

  195460. }

  195461. 

  195462. static int statRowid(sqlite3_vtab_cursor *pCursor, sqlite_int64 *pRowid){

  195463.   StatCursor *pCsr = (StatCursor *)pCursor;

  195464.   *pRowid = pCsr->iPageno;

  195465.   return SQLITE_OK;

  195466. }

  195467. 

  195468. /*

  195469. ** Invoke this routine to register the "dbstat" virtual table module

  195470. */

  195471. SQLITE_PRIVATE int sqlite3DbstatRegister(sqlite3 *db){

  195472.   static sqlite3_module dbstat_module = {

  195473.     0,                            /* iVersion */

  195474.     statConnect,                  /* xCreate */

  195475.     statConnect,                  /* xConnect */

  195476.     statBestIndex,                /* xBestIndex */

  195477.     statDisconnect,               /* xDisconnect */

  195478.     statDisconnect,               /* xDestroy */

  195479.     statOpen,                     /* xOpen - open a cursor */

  195480.     statClose,                    /* xClose - close a cursor */

  195481.     statFilter,                   /* xFilter - configure scan constraints */

  195482.     statNext,                     /* xNext - advance a cursor */

  195483.     statEof,                      /* xEof - check for end of scan */

  195484.     statColumn,                   /* xColumn - read data */

  195485.     statRowid,                    /* xRowid - read data */

  195486.     0,                            /* xUpdate */

  195487.     0,                            /* xBegin */

  195488.     0,                            /* xSync */

  195489.     0,                            /* xCommit */

  195490.     0,                            /* xRollback */

  195491.     0,                            /* xFindMethod */

  195492.     0,                            /* xRename */

  195493.     0,                            /* xSavepoint */

  195494.     0,                            /* xRelease */

  195495.     0,                            /* xRollbackTo */

  195496.     0                             /* xShadowName */

  195497.   };

  195498.   return sqlite3_create_module(db, "dbstat", &dbstat_module, 0);

  195499. }

  195500. #elif defined(SQLITE_ENABLE_DBSTAT_VTAB)

  195501. SQLITE_PRIVATE int sqlite3DbstatRegister(sqlite3 *db){ return SQLITE_OK; }

  195502. #endif /* SQLITE_ENABLE_DBSTAT_VTAB */

  195503. 

  195504. /************** End of dbstat.c **********************************************/

  195505. /************** Begin file dbpage.c ******************************************/

  195506. /*

  195507. ** 2017-10-11

  195508. **

  195509. ** The author disclaims copyright to this source code.  In place of

  195510. ** a legal notice, here is a blessing:

  195511. **

  195512. **    May you do good and not evil.

  195513. **    May you find forgiveness for yourself and forgive others.

  195514. **    May you share freely, never taking more than you give.

  195515. **

  195516. ******************************************************************************

  195517. **

  195518. ** This file contains an implementation of the "sqlite_dbpage" virtual table.

  195519. **

  195520. ** The sqlite_dbpage virtual table is used to read or write whole raw

  195521. ** pages of the database file.  The pager interface is used so that 

  195522. ** uncommitted changes and changes recorded in the WAL file are correctly

  195523. ** retrieved.

  195524. **

  195525. ** Usage example:

  195526. **

  195527. **    SELECT data FROM sqlite_dbpage('aux1') WHERE pgno=123;

  195528. **

  195529. ** This is an eponymous virtual table so it does not need to be created before

  195530. ** use.  The optional argument to the sqlite_dbpage() table name is the

  195531. ** schema for the database file that is to be read.  The default schema is

  195532. ** "main".

  195533. **

  195534. ** The data field of sqlite_dbpage table can be updated.  The new

  195535. ** value must be a BLOB which is the correct page size, otherwise the

  195536. ** update fails.  Rows may not be deleted or inserted.

  195537. */

  195538. 

  195539. /* #include "sqliteInt.h"   ** Requires access to internal data structures ** */

  195540. #if (defined(SQLITE_ENABLE_DBPAGE_VTAB) || defined(SQLITE_TEST)) \

  195541.     && !defined(SQLITE_OMIT_VIRTUALTABLE)

  195542. 

  195543. typedef struct DbpageTable DbpageTable;

  195544. typedef struct DbpageCursor DbpageCursor;

  195545. 

  195546. struct DbpageCursor {

  195547.   sqlite3_vtab_cursor base;       /* Base class.  Must be first */

  195548.   int pgno;                       /* Current page number */

  195549.   int mxPgno;                     /* Last page to visit on this scan */

  195550.   Pager *pPager;                  /* Pager being read/written */

  195551.   DbPage *pPage1;                 /* Page 1 of the database */

  195552.   int iDb;                        /* Index of database to analyze */

  195553.   int szPage;                     /* Size of each page in bytes */

  195554. };

  195555. 

  195556. struct DbpageTable {

  195557.   sqlite3_vtab base;              /* Base class.  Must be first */

  195558.   sqlite3 *db;                    /* The database */

  195559. };

  195560. 

  195561. /* Columns */

  195562. #define DBPAGE_COLUMN_PGNO    0

  195563. #define DBPAGE_COLUMN_DATA    1

  195564. #define DBPAGE_COLUMN_SCHEMA  2

  195565. 

  195566. 

  195567. 

  195568. /*

  195569. ** Connect to or create a dbpagevfs virtual table.

  195570. */

  195571. static int dbpageConnect(

  195572.   sqlite3 *db,

  195573.   void *pAux,

  195574.   int argc, const char *const*argv,

  195575.   sqlite3_vtab **ppVtab,

  195576.   char **pzErr

  195577. ){

  195578.   DbpageTable *pTab = 0;

  195579.   int rc = SQLITE_OK;

  195580. 

  195581.   rc = sqlite3_declare_vtab(db, 

  195582.           "CREATE TABLE x(pgno INTEGER PRIMARY KEY, data BLOB, schema HIDDEN)");

  195583.   if( rc==SQLITE_OK ){

  195584.     pTab = (DbpageTable *)sqlite3_malloc64(sizeof(DbpageTable));

  195585.     if( pTab==0 ) rc = SQLITE_NOMEM_BKPT;

  195586.   }

  195587. 

  195588.   assert( rc==SQLITE_OK || pTab==0 );

  195589.   if( rc==SQLITE_OK ){

  195590.     memset(pTab, 0, sizeof(DbpageTable));

  195591.     pTab->db = db;

  195592.   }

  195593. 

  195594.   *ppVtab = (sqlite3_vtab*)pTab;

  195595.   return rc;

  195596. }

  195597. 

  195598. /*

  195599. ** Disconnect from or destroy a dbpagevfs virtual table.

  195600. */

  195601. static int dbpageDisconnect(sqlite3_vtab *pVtab){

  195602.   sqlite3_free(pVtab);

  195603.   return SQLITE_OK;

  195604. }

  195605. 

  195606. /*

  195607. ** idxNum:

  195608. **

  195609. **     0     schema=main, full table scan

  195610. **     1     schema=main, pgno=?1

  195611. **     2     schema=?1, full table scan

  195612. **     3     schema=?1, pgno=?2

  195613. */

  195614. static int dbpageBestIndex(sqlite3_vtab *tab, sqlite3_index_info *pIdxInfo){

  195615.   int i;

  195616.   int iPlan = 0;

  195617. 

  195618.   /* If there is a schema= constraint, it must be honored.  Report a

  195619.   ** ridiculously large estimated cost if the schema= constraint is

  195620.   ** unavailable

  195621.   */

  195622.   for(i=0; i<pIdxInfo->nConstraint; i++){

  195623.     struct sqlite3_index_constraint *p = &pIdxInfo->aConstraint[i];

  195624.     if( p->iColumn!=DBPAGE_COLUMN_SCHEMA ) continue;

  195625.     if( p->op!=SQLITE_INDEX_CONSTRAINT_EQ ) continue;

  195626.     if( !p->usable ){

  195627.       /* No solution. */

  195628.       return SQLITE_CONSTRAINT;

  195629.     }

  195630.     iPlan = 2;

  195631.     pIdxInfo->aConstraintUsage[i].argvIndex = 1;

  195632.     pIdxInfo->aConstraintUsage[i].omit = 1;

  195633.     break;

  195634.   }

  195635. 

  195636.   /* If we reach this point, it means that either there is no schema=

  195637.   ** constraint (in which case we use the "main" schema) or else the

  195638.   ** schema constraint was accepted.  Lower the estimated cost accordingly

  195639.   */

  195640.   pIdxInfo->estimatedCost = 1.0e6;

  195641. 

  195642.   /* Check for constraints against pgno */

  195643.   for(i=0; i<pIdxInfo->nConstraint; i++){

  195644.     struct sqlite3_index_constraint *p = &pIdxInfo->aConstraint[i];

  195645.     if( p->usable && p->iColumn<=0 && p->op==SQLITE_INDEX_CONSTRAINT_EQ ){

  195646.       pIdxInfo->estimatedRows = 1;

  195647.       pIdxInfo->idxFlags = SQLITE_INDEX_SCAN_UNIQUE;

  195648.       pIdxInfo->estimatedCost = 1.0;

  195649.       pIdxInfo->aConstraintUsage[i].argvIndex = iPlan ? 2 : 1;

  195650.       pIdxInfo->aConstraintUsage[i].omit = 1;

  195651.       iPlan |= 1;

  195652.       break;

  195653.     }

  195654.   }

  195655.   pIdxInfo->idxNum = iPlan;

  195656. 

  195657.   if( pIdxInfo->nOrderBy>=1

  195658.    && pIdxInfo->aOrderBy[0].iColumn<=0

  195659.    && pIdxInfo->aOrderBy[0].desc==0

  195660.   ){

  195661.     pIdxInfo->orderByConsumed = 1;

  195662.   }

  195663.   return SQLITE_OK;

  195664. }

  195665. 

  195666. /*

  195667. ** Open a new dbpagevfs cursor.

  195668. */

  195669. static int dbpageOpen(sqlite3_vtab *pVTab, sqlite3_vtab_cursor **ppCursor){

  195670.   DbpageCursor *pCsr;

  195671. 

  195672.   pCsr = (DbpageCursor *)sqlite3_malloc64(sizeof(DbpageCursor));

  195673.   if( pCsr==0 ){

  195674.     return SQLITE_NOMEM_BKPT;

  195675.   }else{

  195676.     memset(pCsr, 0, sizeof(DbpageCursor));

  195677.     pCsr->base.pVtab = pVTab;

  195678.     pCsr->pgno = -1;

  195679.   }

  195680. 

  195681.   *ppCursor = (sqlite3_vtab_cursor *)pCsr;

  195682.   return SQLITE_OK;

  195683. }

  195684. 

  195685. /*

  195686. ** Close a dbpagevfs cursor.

  195687. */

  195688. static int dbpageClose(sqlite3_vtab_cursor *pCursor){

  195689.   DbpageCursor *pCsr = (DbpageCursor *)pCursor;

  195690.   if( pCsr->pPage1 ) sqlite3PagerUnrefPageOne(pCsr->pPage1);

  195691.   sqlite3_free(pCsr);

  195692.   return SQLITE_OK;

  195693. }

  195694. 

  195695. /*

  195696. ** Move a dbpagevfs cursor to the next entry in the file.

  195697. */

  195698. static int dbpageNext(sqlite3_vtab_cursor *pCursor){

  195699.   int rc = SQLITE_OK;

  195700.   DbpageCursor *pCsr = (DbpageCursor *)pCursor;

  195701.   pCsr->pgno++;

  195702.   return rc;

  195703. }

  195704. 

  195705. static int dbpageEof(sqlite3_vtab_cursor *pCursor){

  195706.   DbpageCursor *pCsr = (DbpageCursor *)pCursor;

  195707.   return pCsr->pgno > pCsr->mxPgno;

  195708. }

  195709. 

  195710. /*

  195711. ** idxNum:

  195712. **

  195713. **     0     schema=main, full table scan

  195714. **     1     schema=main, pgno=?1

  195715. **     2     schema=?1, full table scan

  195716. **     3     schema=?1, pgno=?2

  195717. **

  195718. ** idxStr is not used

  195719. */

  195720. static int dbpageFilter(

  195721.   sqlite3_vtab_cursor *pCursor, 

  195722.   int idxNum, const char *idxStr,

  195723.   int argc, sqlite3_value **argv

  195724. ){

  195725.   DbpageCursor *pCsr = (DbpageCursor *)pCursor;

  195726.   DbpageTable *pTab = (DbpageTable *)pCursor->pVtab;

  195727.   int rc;

  195728.   sqlite3 *db = pTab->db;

  195729.   Btree *pBt;

  195730. 

  195731.   /* Default setting is no rows of result */

  195732.   pCsr->pgno = 1; 

  195733.   pCsr->mxPgno = 0;

  195734. 

  195735.   if( idxNum & 2 ){

  195736.     const char *zSchema;

  195737.     assert( argc>=1 );

  195738.     zSchema = (const char*)sqlite3_value_text(argv[0]);

  195739.     pCsr->iDb = sqlite3FindDbName(db, zSchema);

  195740.     if( pCsr->iDb<0 ) return SQLITE_OK;

  195741.   }else{

  195742.     pCsr->iDb = 0;

  195743.   }

  195744.   pBt = db->aDb[pCsr->iDb].pBt;

  195745.   if( pBt==0 ) return SQLITE_OK;

  195746.   pCsr->pPager = sqlite3BtreePager(pBt);

  195747.   pCsr->szPage = sqlite3BtreeGetPageSize(pBt);

  195748.   pCsr->mxPgno = sqlite3BtreeLastPage(pBt);

  195749.   if( idxNum & 1 ){

  195750.     assert( argc>(idxNum>>1) );

  195751.     pCsr->pgno = sqlite3_value_int(argv[idxNum>>1]);

  195752.     if( pCsr->pgno<1 || pCsr->pgno>pCsr->mxPgno ){

  195753.       pCsr->pgno = 1;

  195754.       pCsr->mxPgno = 0;

  195755.     }else{

  195756.       pCsr->mxPgno = pCsr->pgno;

  195757.     }

  195758.   }else{

  195759.     assert( pCsr->pgno==1 );

  195760.   }

  195761.   if( pCsr->pPage1 ) sqlite3PagerUnrefPageOne(pCsr->pPage1);

  195762.   rc = sqlite3PagerGet(pCsr->pPager, 1, &pCsr->pPage1, 0);

  195763.   return rc;

  195764. }

  195765. 

  195766. static int dbpageColumn(

  195767.   sqlite3_vtab_cursor *pCursor, 

  195768.   sqlite3_context *ctx, 

  195769.   int i

  195770. ){

  195771.   DbpageCursor *pCsr = (DbpageCursor *)pCursor;

  195772.   int rc = SQLITE_OK;

  195773.   switch( i ){

  195774.     case 0: {           /* pgno */

  195775.       sqlite3_result_int(ctx, pCsr->pgno);

  195776.       break;

  195777.     }

  195778.     case 1: {           /* data */

  195779.       DbPage *pDbPage = 0;

  195780.       rc = sqlite3PagerGet(pCsr->pPager, pCsr->pgno, (DbPage**)&pDbPage, 0);

  195781.       if( rc==SQLITE_OK ){

  195782.         sqlite3_result_blob(ctx, sqlite3PagerGetData(pDbPage), pCsr->szPage,

  195783.                             SQLITE_TRANSIENT);

  195784.       }

  195785.       sqlite3PagerUnref(pDbPage);

  195786.       break;

  195787.     }

  195788.     default: {          /* schema */

  195789.       sqlite3 *db = sqlite3_context_db_handle(ctx);

  195790.       sqlite3_result_text(ctx, db->aDb[pCsr->iDb].zDbSName, -1, SQLITE_STATIC);

  195791.       break;

  195792.     }

  195793.   }

  195794.   return SQLITE_OK;

  195795. }

  195796. 

  195797. static int dbpageRowid(sqlite3_vtab_cursor *pCursor, sqlite_int64 *pRowid){

  195798.   DbpageCursor *pCsr = (DbpageCursor *)pCursor;

  195799.   *pRowid = pCsr->pgno;

  195800.   return SQLITE_OK;

  195801. }

  195802. 

  195803. static int dbpageUpdate(

  195804.   sqlite3_vtab *pVtab,

  195805.   int argc,

  195806.   sqlite3_value **argv,

  195807.   sqlite_int64 *pRowid

  195808. ){

  195809.   DbpageTable *pTab = (DbpageTable *)pVtab;

  195810.   Pgno pgno;

  195811.   DbPage *pDbPage = 0;

  195812.   int rc = SQLITE_OK;

  195813.   char *zErr = 0;

  195814.   const char *zSchema;

  195815.   int iDb;

  195816.   Btree *pBt;

  195817.   Pager *pPager;

  195818.   int szPage;

  195819. 

  195820.   if( pTab->db->flags & SQLITE_Defensive ){

  195821.     zErr = "read-only";

  195822.     goto update_fail;

  195823.   }

  195824.   if( argc==1 ){

  195825.     zErr = "cannot delete";

  195826.     goto update_fail;

  195827.   }

  195828.   pgno = sqlite3_value_int(argv[0]);

  195829.   if( (Pgno)sqlite3_value_int(argv[1])!=pgno ){

  195830.     zErr = "cannot insert";

  195831.     goto update_fail;

  195832.   }

  195833.   zSchema = (const char*)sqlite3_value_text(argv[4]);

  195834.   iDb = zSchema ? sqlite3FindDbName(pTab->db, zSchema) : -1;

  195835.   if( iDb<0 ){

  195836.     zErr = "no such schema";

  195837.     goto update_fail;

  195838.   }

  195839.   pBt = pTab->db->aDb[iDb].pBt;

  195840.   if( pgno<1 || pBt==0 || pgno>(int)sqlite3BtreeLastPage(pBt) ){

  195841.     zErr = "bad page number";

  195842.     goto update_fail;

  195843.   }

  195844.   szPage = sqlite3BtreeGetPageSize(pBt);

  195845.   if( sqlite3_value_type(argv[3])!=SQLITE_BLOB 

  195846.    || sqlite3_value_bytes(argv[3])!=szPage

  195847.   ){

  195848.     zErr = "bad page value";

  195849.     goto update_fail;

  195850.   }

  195851.   pPager = sqlite3BtreePager(pBt);

  195852.   rc = sqlite3PagerGet(pPager, pgno, (DbPage**)&pDbPage, 0);

  195853.   if( rc==SQLITE_OK ){

  195854.     rc = sqlite3PagerWrite(pDbPage);

  195855.     if( rc==SQLITE_OK ){

  195856.       memcpy(sqlite3PagerGetData(pDbPage),

  195857.              sqlite3_value_blob(argv[3]),

  195858.              szPage);

  195859.     }

  195860.   }

  195861.   sqlite3PagerUnref(pDbPage);

  195862.   return rc;

  195863. 

  195864. update_fail:

  195865.   sqlite3_free(pVtab->zErrMsg);

  195866.   pVtab->zErrMsg = sqlite3_mprintf("%s", zErr);

  195867.   return SQLITE_ERROR;

  195868. }

  195869. 

  195870. /* Since we do not know in advance which database files will be

  195871. ** written by the sqlite_dbpage virtual table, start a write transaction

  195872. ** on them all.

  195873. */

  195874. static int dbpageBegin(sqlite3_vtab *pVtab){

  195875.   DbpageTable *pTab = (DbpageTable *)pVtab;

  195876.   sqlite3 *db = pTab->db;

  195877.   int i;

  195878.   for(i=0; i<db->nDb; i++){

  195879.     Btree *pBt = db->aDb[i].pBt;

  195880.     if( pBt ) sqlite3BtreeBeginTrans(pBt, 1, 0);

  195881.   }

  195882.   return SQLITE_OK;

  195883. }

  195884. 

  195885. 

  195886. /*

  195887. ** Invoke this routine to register the "dbpage" virtual table module

  195888. */

  195889. SQLITE_PRIVATE int sqlite3DbpageRegister(sqlite3 *db){

  195890.   static sqlite3_module dbpage_module = {

  195891.     0,                            /* iVersion */

  195892.     dbpageConnect,                /* xCreate */

  195893.     dbpageConnect,                /* xConnect */

  195894.     dbpageBestIndex,              /* xBestIndex */

  195895.     dbpageDisconnect,             /* xDisconnect */

  195896.     dbpageDisconnect,             /* xDestroy */

  195897.     dbpageOpen,                   /* xOpen - open a cursor */

  195898.     dbpageClose,                  /* xClose - close a cursor */

  195899.     dbpageFilter,                 /* xFilter - configure scan constraints */

  195900.     dbpageNext,                   /* xNext - advance a cursor */

  195901.     dbpageEof,                    /* xEof - check for end of scan */

  195902.     dbpageColumn,                 /* xColumn - read data */

  195903.     dbpageRowid,                  /* xRowid - read data */

  195904.     dbpageUpdate,                 /* xUpdate */

  195905.     dbpageBegin,                  /* xBegin */

  195906.     0,                            /* xSync */

  195907.     0,                            /* xCommit */

  195908.     0,                            /* xRollback */

  195909.     0,                            /* xFindMethod */

  195910.     0,                            /* xRename */

  195911.     0,                            /* xSavepoint */

  195912.     0,                            /* xRelease */

  195913.     0,                            /* xRollbackTo */

  195914.     0                             /* xShadowName */

  195915.   };

  195916.   return sqlite3_create_module(db, "sqlite_dbpage", &dbpage_module, 0);

  195917. }

  195918. #elif defined(SQLITE_ENABLE_DBPAGE_VTAB)

  195919. SQLITE_PRIVATE int sqlite3DbpageRegister(sqlite3 *db){ return SQLITE_OK; }

  195920. #endif /* SQLITE_ENABLE_DBSTAT_VTAB */

  195921. 

  195922. /************** End of dbpage.c **********************************************/

  195923. /************** Begin file sqlite3session.c **********************************/

  195924. 

  195925. #if defined(SQLITE_ENABLE_SESSION) && defined(SQLITE_ENABLE_PREUPDATE_HOOK)

  195926. /* #include "sqlite3session.h" */

  195927. /* #include <assert.h> */

  195928. /* #include <string.h> */

  195929. 

  195930. #ifndef SQLITE_AMALGAMATION

  195931. /* # include "sqliteInt.h" */

  195932. /* # include "vdbeInt.h" */

  195933. #endif

  195934. 

  195935. typedef struct SessionTable SessionTable;

  195936. typedef struct SessionChange SessionChange;

  195937. typedef struct SessionBuffer SessionBuffer;

  195938. typedef struct SessionInput SessionInput;

  195939. 

  195940. /*

  195941. ** Minimum chunk size used by streaming versions of functions.

  195942. */

  195943. #ifndef SESSIONS_STRM_CHUNK_SIZE

  195944. # ifdef SQLITE_TEST

  195945. #   define SESSIONS_STRM_CHUNK_SIZE 64

  195946. # else

  195947. #   define SESSIONS_STRM_CHUNK_SIZE 1024

  195948. # endif

  195949. #endif

  195950. 

  195951. static int sessions_strm_chunk_size = SESSIONS_STRM_CHUNK_SIZE;

  195952. 

  195953. typedef struct SessionHook SessionHook;

  195954. struct SessionHook {

  195955.   void *pCtx;

  195956.   int (*xOld)(void*,int,sqlite3_value**);

  195957.   int (*xNew)(void*,int,sqlite3_value**);

  195958.   int (*xCount)(void*);

  195959.   int (*xDepth)(void*);

  195960. };

  195961. 

  195962. /*

  195963. ** Session handle structure.

  195964. */

  195965. struct sqlite3_session {

  195966.   sqlite3 *db;                    /* Database handle session is attached to */

  195967.   char *zDb;                      /* Name of database session is attached to */

  195968.   int bEnable;                    /* True if currently recording */

  195969.   int bIndirect;                  /* True if all changes are indirect */

  195970.   int bAutoAttach;                /* True to auto-attach tables */

  195971.   int rc;                         /* Non-zero if an error has occurred */

  195972.   void *pFilterCtx;               /* First argument to pass to xTableFilter */

  195973.   int (*xTableFilter)(void *pCtx, const char *zTab);

  195974.   sqlite3_value *pZeroBlob;       /* Value containing X'' */

  195975.   sqlite3_session *pNext;         /* Next session object on same db. */

  195976.   SessionTable *pTable;           /* List of attached tables */

  195977.   SessionHook hook;               /* APIs to grab new and old data with */

  195978. };

  195979. 

  195980. /*

  195981. ** Instances of this structure are used to build strings or binary records.

  195982. */

  195983. struct SessionBuffer {

  195984.   u8 *aBuf;                       /* Pointer to changeset buffer */

  195985.   int nBuf;                       /* Size of buffer aBuf */

  195986.   int nAlloc;                     /* Size of allocation containing aBuf */

  195987. };

  195988. 

  195989. /*

  195990. ** An object of this type is used internally as an abstraction for 

  195991. ** input data. Input data may be supplied either as a single large buffer

  195992. ** (e.g. sqlite3changeset_start()) or using a stream function (e.g.

  195993. **  sqlite3changeset_start_strm()).

  195994. */

  195995. struct SessionInput {

  195996.   int bNoDiscard;                 /* If true, do not discard in InputBuffer() */

  195997.   int iCurrent;                   /* Offset in aData[] of current change */

  195998.   int iNext;                      /* Offset in aData[] of next change */

  195999.   u8 *aData;                      /* Pointer to buffer containing changeset */

  196000.   int nData;                      /* Number of bytes in aData */

  196001. 

  196002.   SessionBuffer buf;              /* Current read buffer */

  196003.   int (*xInput)(void*, void*, int*);        /* Input stream call (or NULL) */

  196004.   void *pIn;                                /* First argument to xInput */

  196005.   int bEof;                       /* Set to true after xInput finished */

  196006. };

  196007. 

  196008. /*

  196009. ** Structure for changeset iterators.

  196010. */

  196011. struct sqlite3_changeset_iter {

  196012.   SessionInput in;                /* Input buffer or stream */

  196013.   SessionBuffer tblhdr;           /* Buffer to hold apValue/zTab/abPK/ */

  196014.   int bPatchset;                  /* True if this is a patchset */

  196015.   int bInvert;                    /* True to invert changeset */

  196016.   int rc;                         /* Iterator error code */

  196017.   sqlite3_stmt *pConflict;        /* Points to conflicting row, if any */

  196018.   char *zTab;                     /* Current table */

  196019.   int nCol;                       /* Number of columns in zTab */

  196020.   int op;                         /* Current operation */

  196021.   int bIndirect;                  /* True if current change was indirect */

  196022.   u8 *abPK;                       /* Primary key array */

  196023.   sqlite3_value **apValue;        /* old.* and new.* values */

  196024. };

  196025. 

  196026. /*

  196027. ** Each session object maintains a set of the following structures, one

  196028. ** for each table the session object is monitoring. The structures are

  196029. ** stored in a linked list starting at sqlite3_session.pTable.

  196030. **

  196031. ** The keys of the SessionTable.aChange[] hash table are all rows that have

  196032. ** been modified in any way since the session object was attached to the

  196033. ** table.

  196034. **

  196035. ** The data associated with each hash-table entry is a structure containing

  196036. ** a subset of the initial values that the modified row contained at the

  196037. ** start of the session. Or no initial values if the row was inserted.

  196038. */

  196039. struct SessionTable {

  196040.   SessionTable *pNext;

  196041.   char *zName;                    /* Local name of table */

  196042.   int nCol;                       /* Number of columns in table zName */

  196043.   int bStat1;                     /* True if this is sqlite_stat1 */

  196044.   const char **azCol;             /* Column names */

  196045.   u8 *abPK;                       /* Array of primary key flags */

  196046.   int nEntry;                     /* Total number of entries in hash table */

  196047.   int nChange;                    /* Size of apChange[] array */

  196048.   SessionChange **apChange;       /* Hash table buckets */

  196049. };

  196050. 

  196051. /* 

  196052. ** RECORD FORMAT:

  196053. **

  196054. ** The following record format is similar to (but not compatible with) that 

  196055. ** used in SQLite database files. This format is used as part of the 

  196056. ** change-set binary format, and so must be architecture independent.

  196057. **

  196058. ** Unlike the SQLite database record format, each field is self-contained -

  196059. ** there is no separation of header and data. Each field begins with a

  196060. ** single byte describing its type, as follows:

  196061. **

  196062. **       0x00: Undefined value.

  196063. **       0x01: Integer value.

  196064. **       0x02: Real value.

  196065. **       0x03: Text value.

  196066. **       0x04: Blob value.

  196067. **       0x05: SQL NULL value.

  196068. **

  196069. ** Note that the above match the definitions of SQLITE_INTEGER, SQLITE_TEXT

  196070. ** and so on in sqlite3.h. For undefined and NULL values, the field consists

  196071. ** only of the single type byte. For other types of values, the type byte

  196072. ** is followed by:

  196073. **

  196074. **   Text values:

  196075. **     A varint containing the number of bytes in the value (encoded using

  196076. **     UTF-8). Followed by a buffer containing the UTF-8 representation

  196077. **     of the text value. There is no nul terminator.

  196078. **

  196079. **   Blob values:

  196080. **     A varint containing the number of bytes in the value, followed by

  196081. **     a buffer containing the value itself.

  196082. **

  196083. **   Integer values:

  196084. **     An 8-byte big-endian integer value.

  196085. **

  196086. **   Real values:

  196087. **     An 8-byte big-endian IEEE 754-2008 real value.

  196088. **

  196089. ** Varint values are encoded in the same way as varints in the SQLite 

  196090. ** record format.

  196091. **

  196092. ** CHANGESET FORMAT:

  196093. **

  196094. ** A changeset is a collection of DELETE, UPDATE and INSERT operations on

  196095. ** one or more tables. Operations on a single table are grouped together,

  196096. ** but may occur in any order (i.e. deletes, updates and inserts are all

  196097. ** mixed together).

  196098. **

  196099. ** Each group of changes begins with a table header:

  196100. **

  196101. **   1 byte: Constant 0x54 (capital 'T')

  196102. **   Varint: Number of columns in the table.

  196103. **   nCol bytes: 0x01 for PK columns, 0x00 otherwise.

  196104. **   N bytes: Unqualified table name (encoded using UTF-8). Nul-terminated.

  196105. **

  196106. ** Followed by one or more changes to the table.

  196107. **

  196108. **   1 byte: Either SQLITE_INSERT (0x12), UPDATE (0x17) or DELETE (0x09).

  196109. **   1 byte: The "indirect-change" flag.

  196110. **   old.* record: (delete and update only)

  196111. **   new.* record: (insert and update only)

  196112. **

  196113. ** The "old.*" and "new.*" records, if present, are N field records in the

  196114. ** format described above under "RECORD FORMAT", where N is the number of

  196115. ** columns in the table. The i'th field of each record is associated with

  196116. ** the i'th column of the table, counting from left to right in the order

  196117. ** in which columns were declared in the CREATE TABLE statement.

  196118. **

  196119. ** The new.* record that is part of each INSERT change contains the values

  196120. ** that make up the new row. Similarly, the old.* record that is part of each

  196121. ** DELETE change contains the values that made up the row that was deleted 

  196122. ** from the database. In the changeset format, the records that are part

  196123. ** of INSERT or DELETE changes never contain any undefined (type byte 0x00)

  196124. ** fields.

  196125. **

  196126. ** Within the old.* record associated with an UPDATE change, all fields

  196127. ** associated with table columns that are not PRIMARY KEY columns and are

  196128. ** not modified by the UPDATE change are set to "undefined". Other fields

  196129. ** are set to the values that made up the row before the UPDATE that the

  196130. ** change records took place. Within the new.* record, fields associated 

  196131. ** with table columns modified by the UPDATE change contain the new 

  196132. ** values. Fields associated with table columns that are not modified

  196133. ** are set to "undefined".

  196134. **

  196135. ** PATCHSET FORMAT:

  196136. **

  196137. ** A patchset is also a collection of changes. It is similar to a changeset,

  196138. ** but leaves undefined those fields that are not useful if no conflict

  196139. ** resolution is required when applying the changeset.

  196140. **

  196141. ** Each group of changes begins with a table header:

  196142. **

  196143. **   1 byte: Constant 0x50 (capital 'P')

  196144. **   Varint: Number of columns in the table.

  196145. **   nCol bytes: 0x01 for PK columns, 0x00 otherwise.

  196146. **   N bytes: Unqualified table name (encoded using UTF-8). Nul-terminated.

  196147. **

  196148. ** Followed by one or more changes to the table.

  196149. **

  196150. **   1 byte: Either SQLITE_INSERT (0x12), UPDATE (0x17) or DELETE (0x09).

  196151. **   1 byte: The "indirect-change" flag.

  196152. **   single record: (PK fields for DELETE, PK and modified fields for UPDATE,

  196153. **                   full record for INSERT).

  196154. **

  196155. ** As in the changeset format, each field of the single record that is part

  196156. ** of a patchset change is associated with the correspondingly positioned

  196157. ** table column, counting from left to right within the CREATE TABLE 

  196158. ** statement.

  196159. **

  196160. ** For a DELETE change, all fields within the record except those associated

  196161. ** with PRIMARY KEY columns are omitted. The PRIMARY KEY fields contain the

  196162. ** values identifying the row to delete.

  196163. **

  196164. ** For an UPDATE change, all fields except those associated with PRIMARY KEY

  196165. ** columns and columns that are modified by the UPDATE are set to "undefined".

  196166. ** PRIMARY KEY fields contain the values identifying the table row to update,

  196167. ** and fields associated with modified columns contain the new column values.

  196168. **

  196169. ** The records associated with INSERT changes are in the same format as for

  196170. ** changesets. It is not possible for a record associated with an INSERT

  196171. ** change to contain a field set to "undefined".

  196172. **

  196173. ** REBASE BLOB FORMAT:

  196174. **

  196175. ** A rebase blob may be output by sqlite3changeset_apply_v2() and its 

  196176. ** streaming equivalent for use with the sqlite3_rebaser APIs to rebase

  196177. ** existing changesets. A rebase blob contains one entry for each conflict

  196178. ** resolved using either the OMIT or REPLACE strategies within the apply_v2()

  196179. ** call.

  196180. **

  196181. ** The format used for a rebase blob is very similar to that used for

  196182. ** changesets. All entries related to a single table are grouped together.

  196183. **

  196184. ** Each group of entries begins with a table header in changeset format:

  196185. **

  196186. **   1 byte: Constant 0x54 (capital 'T')

  196187. **   Varint: Number of columns in the table.

  196188. **   nCol bytes: 0x01 for PK columns, 0x00 otherwise.

  196189. **   N bytes: Unqualified table name (encoded using UTF-8). Nul-terminated.

  196190. **

  196191. ** Followed by one or more entries associated with the table.

  196192. **

  196193. **   1 byte: Either SQLITE_INSERT (0x12), DELETE (0x09).

  196194. **   1 byte: Flag. 0x01 for REPLACE, 0x00 for OMIT.

  196195. **   record: (in the record format defined above).

  196196. **

  196197. ** In a rebase blob, the first field is set to SQLITE_INSERT if the change

  196198. ** that caused the conflict was an INSERT or UPDATE, or to SQLITE_DELETE if

  196199. ** it was a DELETE. The second field is set to 0x01 if the conflict 

  196200. ** resolution strategy was REPLACE, or 0x00 if it was OMIT.

  196201. **

  196202. ** If the change that caused the conflict was a DELETE, then the single

  196203. ** record is a copy of the old.* record from the original changeset. If it

  196204. ** was an INSERT, then the single record is a copy of the new.* record. If

  196205. ** the conflicting change was an UPDATE, then the single record is a copy

  196206. ** of the new.* record with the PK fields filled in based on the original

  196207. ** old.* record.

  196208. */

  196209. 

  196210. /*

  196211. ** For each row modified during a session, there exists a single instance of

  196212. ** this structure stored in a SessionTable.aChange[] hash table.

  196213. */

  196214. struct SessionChange {

  196215.   int op;                         /* One of UPDATE, DELETE, INSERT */

  196216.   int bIndirect;                  /* True if this change is "indirect" */

  196217.   int nRecord;                    /* Number of bytes in buffer aRecord[] */

  196218.   u8 *aRecord;                    /* Buffer containing old.* record */

  196219.   SessionChange *pNext;           /* For hash-table collisions */

  196220. };

  196221. 

  196222. /*

  196223. ** Write a varint with value iVal into the buffer at aBuf. Return the 

  196224. ** number of bytes written.

  196225. */

  196226. static int sessionVarintPut(u8 *aBuf, int iVal){

  196227.   return putVarint32(aBuf, iVal);

  196228. }

  196229. 

  196230. /*

  196231. ** Return the number of bytes required to store value iVal as a varint.

  196232. */

  196233. static int sessionVarintLen(int iVal){

  196234.   return sqlite3VarintLen(iVal);

  196235. }

  196236. 

  196237. /*

  196238. ** Read a varint value from aBuf[] into *piVal. Return the number of 

  196239. ** bytes read.

  196240. */

  196241. static int sessionVarintGet(u8 *aBuf, int *piVal){

  196242.   return getVarint32(aBuf, *piVal);

  196243. }

  196244. 

  196245. /* Load an unaligned and unsigned 32-bit integer */

  196246. #define SESSION_UINT32(x) (((u32)(x)[0]<<24)|((x)[1]<<16)|((x)[2]<<8)|(x)[3])

  196247. 

  196248. /*

  196249. ** Read a 64-bit big-endian integer value from buffer aRec[]. Return

  196250. ** the value read.

  196251. */

  196252. static sqlite3_int64 sessionGetI64(u8 *aRec){

  196253.   u64 x = SESSION_UINT32(aRec);

  196254.   u32 y = SESSION_UINT32(aRec+4);

  196255.   x = (x<<32) + y;

  196256.   return (sqlite3_int64)x;

  196257. }

  196258. 

  196259. /*

  196260. ** Write a 64-bit big-endian integer value to the buffer aBuf[].

  196261. */

  196262. static void sessionPutI64(u8 *aBuf, sqlite3_int64 i){

  196263.   aBuf[0] = (i>>56) & 0xFF;

  196264.   aBuf[1] = (i>>48) & 0xFF;

  196265.   aBuf[2] = (i>>40) & 0xFF;

  196266.   aBuf[3] = (i>>32) & 0xFF;

  196267.   aBuf[4] = (i>>24) & 0xFF;

  196268.   aBuf[5] = (i>>16) & 0xFF;

  196269.   aBuf[6] = (i>> 8) & 0xFF;

  196270.   aBuf[7] = (i>> 0) & 0xFF;

  196271. }

  196272. 

  196273. /*

  196274. ** This function is used to serialize the contents of value pValue (see

  196275. ** comment titled "RECORD FORMAT" above).

  196276. **

  196277. ** If it is non-NULL, the serialized form of the value is written to 

  196278. ** buffer aBuf. *pnWrite is set to the number of bytes written before

  196279. ** returning. Or, if aBuf is NULL, the only thing this function does is

  196280. ** set *pnWrite.

  196281. **

  196282. ** If no error occurs, SQLITE_OK is returned. Or, if an OOM error occurs

  196283. ** within a call to sqlite3_value_text() (may fail if the db is utf-16)) 

  196284. ** SQLITE_NOMEM is returned.

  196285. */

  196286. static int sessionSerializeValue(

  196287.   u8 *aBuf,                       /* If non-NULL, write serialized value here */

  196288.   sqlite3_value *pValue,          /* Value to serialize */

  196289.   sqlite3_int64 *pnWrite          /* IN/OUT: Increment by bytes written */

  196290. ){

  196291.   int nByte;                      /* Size of serialized value in bytes */

  196292. 

  196293.   if( pValue ){

  196294.     int eType;                    /* Value type (SQLITE_NULL, TEXT etc.) */

  196295.   

  196296.     eType = sqlite3_value_type(pValue);

  196297.     if( aBuf ) aBuf[0] = eType;

  196298.   

  196299.     switch( eType ){

  196300.       case SQLITE_NULL: 

  196301.         nByte = 1;

  196302.         break;

  196303.   

  196304.       case SQLITE_INTEGER: 

  196305.       case SQLITE_FLOAT:

  196306.         if( aBuf ){

  196307.           /* TODO: SQLite does something special to deal with mixed-endian

  196308.           ** floating point values (e.g. ARM7). This code probably should

  196309.           ** too.  */

  196310.           u64 i;

  196311.           if( eType==SQLITE_INTEGER ){

  196312.             i = (u64)sqlite3_value_int64(pValue);

  196313.           }else{

  196314.             double r;

  196315.             assert( sizeof(double)==8 && sizeof(u64)==8 );

  196316.             r = sqlite3_value_double(pValue);

  196317.             memcpy(&i, &r, 8);

  196318.           }

  196319.           sessionPutI64(&aBuf[1], i);

  196320.         }

  196321.         nByte = 9; 

  196322.         break;

  196323.   

  196324.       default: {

  196325.         u8 *z;

  196326.         int n;

  196327.         int nVarint;

  196328.   

  196329.         assert( eType==SQLITE_TEXT || eType==SQLITE_BLOB );

  196330.         if( eType==SQLITE_TEXT ){

  196331.           z = (u8 *)sqlite3_value_text(pValue);

  196332.         }else{

  196333.           z = (u8 *)sqlite3_value_blob(pValue);

  196334.         }

  196335.         n = sqlite3_value_bytes(pValue);

  196336.         if( z==0 && (eType!=SQLITE_BLOB || n>0) ) return SQLITE_NOMEM;

  196337.         nVarint = sessionVarintLen(n);

  196338.   

  196339.         if( aBuf ){

  196340.           sessionVarintPut(&aBuf[1], n);

  196341.           if( n ) memcpy(&aBuf[nVarint + 1], z, n);

  196342.         }

  196343.   

  196344.         nByte = 1 + nVarint + n;

  196345.         break;

  196346.       }

  196347.     }

  196348.   }else{

  196349.     nByte = 1;

  196350.     if( aBuf ) aBuf[0] = '\0';

  196351.   }

  196352. 

  196353.   if( pnWrite ) *pnWrite += nByte;

  196354.   return SQLITE_OK;

  196355. }

  196356. 

  196357. 

  196358. /*

  196359. ** This macro is used to calculate hash key values for data structures. In

  196360. ** order to use this macro, the entire data structure must be represented

  196361. ** as a series of unsigned integers. In order to calculate a hash-key value

  196362. ** for a data structure represented as three such integers, the macro may

  196363. ** then be used as follows:

  196364. **

  196365. **    int hash_key_value;

  196366. **    hash_key_value = HASH_APPEND(0, <value 1>);

  196367. **    hash_key_value = HASH_APPEND(hash_key_value, <value 2>);

  196368. **    hash_key_value = HASH_APPEND(hash_key_value, <value 3>);

  196369. **

  196370. ** In practice, the data structures this macro is used for are the primary

  196371. ** key values of modified rows.

  196372. */

  196373. #define HASH_APPEND(hash, add) ((hash) << 3) ^ (hash) ^ (unsigned int)(add)

  196374. 

  196375. /*

  196376. ** Append the hash of the 64-bit integer passed as the second argument to the

  196377. ** hash-key value passed as the first. Return the new hash-key value.

  196378. */

  196379. static unsigned int sessionHashAppendI64(unsigned int h, i64 i){

  196380.   h = HASH_APPEND(h, i & 0xFFFFFFFF);

  196381.   return HASH_APPEND(h, (i>>32)&0xFFFFFFFF);

  196382. }

  196383. 

  196384. /*

  196385. ** Append the hash of the blob passed via the second and third arguments to 

  196386. ** the hash-key value passed as the first. Return the new hash-key value.

  196387. */

  196388. static unsigned int sessionHashAppendBlob(unsigned int h, int n, const u8 *z){

  196389.   int i;

  196390.   for(i=0; i<n; i++) h = HASH_APPEND(h, z[i]);

  196391.   return h;

  196392. }

  196393. 

  196394. /*

  196395. ** Append the hash of the data type passed as the second argument to the

  196396. ** hash-key value passed as the first. Return the new hash-key value.

  196397. */

  196398. static unsigned int sessionHashAppendType(unsigned int h, int eType){

  196399.   return HASH_APPEND(h, eType);

  196400. }

  196401. 

  196402. /*

  196403. ** This function may only be called from within a pre-update callback.

  196404. ** It calculates a hash based on the primary key values of the old.* or 

  196405. ** new.* row currently available and, assuming no error occurs, writes it to

  196406. ** *piHash before returning. If the primary key contains one or more NULL

  196407. ** values, *pbNullPK is set to true before returning.

  196408. **

  196409. ** If an error occurs, an SQLite error code is returned and the final values

  196410. ** of *piHash asn *pbNullPK are undefined. Otherwise, SQLITE_OK is returned

  196411. ** and the output variables are set as described above.

  196412. */

  196413. static int sessionPreupdateHash(

  196414.   sqlite3_session *pSession,      /* Session object that owns pTab */

  196415.   SessionTable *pTab,             /* Session table handle */

  196416.   int bNew,                       /* True to hash the new.* PK */

  196417.   int *piHash,                    /* OUT: Hash value */

  196418.   int *pbNullPK                   /* OUT: True if there are NULL values in PK */

  196419. ){

  196420.   unsigned int h = 0;             /* Hash value to return */

  196421.   int i;                          /* Used to iterate through columns */

  196422. 

  196423.   assert( *pbNullPK==0 );

  196424.   assert( pTab->nCol==pSession->hook.xCount(pSession->hook.pCtx) );

  196425.   for(i=0; i<pTab->nCol; i++){

  196426.     if( pTab->abPK[i] ){

  196427.       int rc;

  196428.       int eType;

  196429.       sqlite3_value *pVal;

  196430. 

  196431.       if( bNew ){

  196432.         rc = pSession->hook.xNew(pSession->hook.pCtx, i, &pVal);

  196433.       }else{

  196434.         rc = pSession->hook.xOld(pSession->hook.pCtx, i, &pVal);

  196435.       }

  196436.       if( rc!=SQLITE_OK ) return rc;

  196437. 

  196438.       eType = sqlite3_value_type(pVal);

  196439.       h = sessionHashAppendType(h, eType);

  196440.       if( eType==SQLITE_INTEGER || eType==SQLITE_FLOAT ){

  196441.         i64 iVal;

  196442.         if( eType==SQLITE_INTEGER ){

  196443.           iVal = sqlite3_value_int64(pVal);

  196444.         }else{

  196445.           double rVal = sqlite3_value_double(pVal);

  196446.           assert( sizeof(iVal)==8 && sizeof(rVal)==8 );

  196447.           memcpy(&iVal, &rVal, 8);

  196448.         }

  196449.         h = sessionHashAppendI64(h, iVal);

  196450.       }else if( eType==SQLITE_TEXT || eType==SQLITE_BLOB ){

  196451.         const u8 *z;

  196452.         int n;

  196453.         if( eType==SQLITE_TEXT ){

  196454.           z = (const u8 *)sqlite3_value_text(pVal);

  196455.         }else{

  196456.           z = (const u8 *)sqlite3_value_blob(pVal);

  196457.         }

  196458.         n = sqlite3_value_bytes(pVal);

  196459.         if( !z && (eType!=SQLITE_BLOB || n>0) ) return SQLITE_NOMEM;

  196460.         h = sessionHashAppendBlob(h, n, z);

  196461.       }else{

  196462.         assert( eType==SQLITE_NULL );

  196463.         assert( pTab->bStat1==0 || i!=1 );

  196464.         *pbNullPK = 1;

  196465.       }

  196466.     }

  196467.   }

  196468. 

  196469.   *piHash = (h % pTab->nChange);

  196470.   return SQLITE_OK;

  196471. }

  196472. 

  196473. /*

  196474. ** The buffer that the argument points to contains a serialized SQL value.

  196475. ** Return the number of bytes of space occupied by the value (including

  196476. ** the type byte).

  196477. */

  196478. static int sessionSerialLen(u8 *a){

  196479.   int e = *a;

  196480.   int n;

  196481.   if( e==0 || e==0xFF ) return 1;

  196482.   if( e==SQLITE_NULL ) return 1;

  196483.   if( e==SQLITE_INTEGER || e==SQLITE_FLOAT ) return 9;

  196484.   return sessionVarintGet(&a[1], &n) + 1 + n;

  196485. }

  196486. 

  196487. /*

  196488. ** Based on the primary key values stored in change aRecord, calculate a

  196489. ** hash key. Assume the has table has nBucket buckets. The hash keys

  196490. ** calculated by this function are compatible with those calculated by

  196491. ** sessionPreupdateHash().

  196492. **

  196493. ** The bPkOnly argument is non-zero if the record at aRecord[] is from

  196494. ** a patchset DELETE. In this case the non-PK fields are omitted entirely.

  196495. */

  196496. static unsigned int sessionChangeHash(

  196497.   SessionTable *pTab,             /* Table handle */

  196498.   int bPkOnly,                    /* Record consists of PK fields only */

  196499.   u8 *aRecord,                    /* Change record */

  196500.   int nBucket                     /* Assume this many buckets in hash table */

  196501. ){

  196502.   unsigned int h = 0;             /* Value to return */

  196503.   int i;                          /* Used to iterate through columns */

  196504.   u8 *a = aRecord;                /* Used to iterate through change record */

  196505. 

  196506.   for(i=0; i<pTab->nCol; i++){

  196507.     int eType = *a;

  196508.     int isPK = pTab->abPK[i];

  196509.     if( bPkOnly && isPK==0 ) continue;

  196510. 

  196511.     /* It is not possible for eType to be SQLITE_NULL here. The session 

  196512.     ** module does not record changes for rows with NULL values stored in

  196513.     ** primary key columns. */

  196514.     assert( eType==SQLITE_INTEGER || eType==SQLITE_FLOAT 

  196515.          || eType==SQLITE_TEXT || eType==SQLITE_BLOB 

  196516.          || eType==SQLITE_NULL || eType==0 

  196517.     );

  196518.     assert( !isPK || (eType!=0 && eType!=SQLITE_NULL) );

  196519. 

  196520.     if( isPK ){

  196521.       a++;

  196522.       h = sessionHashAppendType(h, eType);

  196523.       if( eType==SQLITE_INTEGER || eType==SQLITE_FLOAT ){

  196524.         h = sessionHashAppendI64(h, sessionGetI64(a));

  196525.         a += 8;

  196526.       }else{

  196527.         int n; 

  196528.         a += sessionVarintGet(a, &n);

  196529.         h = sessionHashAppendBlob(h, n, a);

  196530.         a += n;

  196531.       }

  196532.     }else{

  196533.       a += sessionSerialLen(a);

  196534.     }

  196535.   }

  196536.   return (h % nBucket);

  196537. }

  196538. 

  196539. /*

  196540. ** Arguments aLeft and aRight are pointers to change records for table pTab.

  196541. ** This function returns true if the two records apply to the same row (i.e.

  196542. ** have the same values stored in the primary key columns), or false 

  196543. ** otherwise.

  196544. */

  196545. static int sessionChangeEqual(

  196546.   SessionTable *pTab,             /* Table used for PK definition */

  196547.   int bLeftPkOnly,                /* True if aLeft[] contains PK fields only */

  196548.   u8 *aLeft,                      /* Change record */

  196549.   int bRightPkOnly,               /* True if aRight[] contains PK fields only */

  196550.   u8 *aRight                      /* Change record */

  196551. ){

  196552.   u8 *a1 = aLeft;                 /* Cursor to iterate through aLeft */

  196553.   u8 *a2 = aRight;                /* Cursor to iterate through aRight */

  196554.   int iCol;                       /* Used to iterate through table columns */

  196555. 

  196556.   for(iCol=0; iCol<pTab->nCol; iCol++){

  196557.     if( pTab->abPK[iCol] ){

  196558.       int n1 = sessionSerialLen(a1);

  196559.       int n2 = sessionSerialLen(a2);

  196560. 

  196561.       if( n1!=n2 || memcmp(a1, a2, n1) ){

  196562.         return 0;

  196563.       }

  196564.       a1 += n1;

  196565.       a2 += n2;

  196566.     }else{

  196567.       if( bLeftPkOnly==0 ) a1 += sessionSerialLen(a1);

  196568.       if( bRightPkOnly==0 ) a2 += sessionSerialLen(a2);

  196569.     }

  196570.   }

  196571. 

  196572.   return 1;

  196573. }

  196574. 

  196575. /*

  196576. ** Arguments aLeft and aRight both point to buffers containing change

  196577. ** records with nCol columns. This function "merges" the two records into

  196578. ** a single records which is written to the buffer at *paOut. *paOut is

  196579. ** then set to point to one byte after the last byte written before 

  196580. ** returning.

  196581. **

  196582. ** The merging of records is done as follows: For each column, if the 

  196583. ** aRight record contains a value for the column, copy the value from

  196584. ** their. Otherwise, if aLeft contains a value, copy it. If neither

  196585. ** record contains a value for a given column, then neither does the

  196586. ** output record.

  196587. */

  196588. static void sessionMergeRecord(

  196589.   u8 **paOut, 

  196590.   int nCol,

  196591.   u8 *aLeft,

  196592.   u8 *aRight

  196593. ){

  196594.   u8 *a1 = aLeft;                 /* Cursor used to iterate through aLeft */

  196595.   u8 *a2 = aRight;                /* Cursor used to iterate through aRight */

  196596.   u8 *aOut = *paOut;              /* Output cursor */

  196597.   int iCol;                       /* Used to iterate from 0 to nCol */

  196598. 

  196599.   for(iCol=0; iCol<nCol; iCol++){

  196600.     int n1 = sessionSerialLen(a1);

  196601.     int n2 = sessionSerialLen(a2);

  196602.     if( *a2 ){

  196603.       memcpy(aOut, a2, n2);

  196604.       aOut += n2;

  196605.     }else{

  196606.       memcpy(aOut, a1, n1);

  196607.       aOut += n1;

  196608.     }

  196609.     a1 += n1;

  196610.     a2 += n2;

  196611.   }

  196612. 

  196613.   *paOut = aOut;

  196614. }

  196615. 

  196616. /*

  196617. ** This is a helper function used by sessionMergeUpdate().

  196618. **

  196619. ** When this function is called, both *paOne and *paTwo point to a value 

  196620. ** within a change record. Before it returns, both have been advanced so 

  196621. ** as to point to the next value in the record.

  196622. **

  196623. ** If, when this function is called, *paTwo points to a valid value (i.e.

  196624. ** *paTwo[0] is not 0x00 - the "no value" placeholder), a copy of the *paTwo

  196625. ** pointer is returned and *pnVal is set to the number of bytes in the 

  196626. ** serialized value. Otherwise, a copy of *paOne is returned and *pnVal

  196627. ** set to the number of bytes in the value at *paOne. If *paOne points

  196628. ** to the "no value" placeholder, *pnVal is set to 1. In other words:

  196629. **

  196630. **   if( *paTwo is valid ) return *paTwo;

  196631. **   return *paOne;

  196632. **

  196633. */

  196634. static u8 *sessionMergeValue(

  196635.   u8 **paOne,                     /* IN/OUT: Left-hand buffer pointer */

  196636.   u8 **paTwo,                     /* IN/OUT: Right-hand buffer pointer */

  196637.   int *pnVal                      /* OUT: Bytes in returned value */

  196638. ){

  196639.   u8 *a1 = *paOne;

  196640.   u8 *a2 = *paTwo;

  196641.   u8 *pRet = 0;

  196642.   int n1;

  196643. 

  196644.   assert( a1 );

  196645.   if( a2 ){

  196646.     int n2 = sessionSerialLen(a2);

  196647.     if( *a2 ){

  196648.       *pnVal = n2;

  196649.       pRet = a2;

  196650.     }

  196651.     *paTwo = &a2[n2];

  196652.   }

  196653. 

  196654.   n1 = sessionSerialLen(a1);

  196655.   if( pRet==0 ){

  196656.     *pnVal = n1;

  196657.     pRet = a1;

  196658.   }

  196659.   *paOne = &a1[n1];

  196660. 

  196661.   return pRet;

  196662. }

  196663. 

  196664. /*

  196665. ** This function is used by changeset_concat() to merge two UPDATE changes

  196666. ** on the same row.

  196667. */

  196668. static int sessionMergeUpdate(

  196669.   u8 **paOut,                     /* IN/OUT: Pointer to output buffer */

  196670.   SessionTable *pTab,             /* Table change pertains to */

  196671.   int bPatchset,                  /* True if records are patchset records */

  196672.   u8 *aOldRecord1,                /* old.* record for first change */

  196673.   u8 *aOldRecord2,                /* old.* record for second change */

  196674.   u8 *aNewRecord1,                /* new.* record for first change */

  196675.   u8 *aNewRecord2                 /* new.* record for second change */

  196676. ){

  196677.   u8 *aOld1 = aOldRecord1;

  196678.   u8 *aOld2 = aOldRecord2;

  196679.   u8 *aNew1 = aNewRecord1;

  196680.   u8 *aNew2 = aNewRecord2;

  196681. 

  196682.   u8 *aOut = *paOut;

  196683.   int i;

  196684. 

  196685.   if( bPatchset==0 ){

  196686.     int bRequired = 0;

  196687. 

  196688.     assert( aOldRecord1 && aNewRecord1 );

  196689. 

  196690.     /* Write the old.* vector first. */

  196691.     for(i=0; i<pTab->nCol; i++){

  196692.       int nOld;

  196693.       u8 *aOld;

  196694.       int nNew;

  196695.       u8 *aNew;

  196696. 

  196697.       aOld = sessionMergeValue(&aOld1, &aOld2, &nOld);

  196698.       aNew = sessionMergeValue(&aNew1, &aNew2, &nNew);

  196699.       if( pTab->abPK[i] || nOld!=nNew || memcmp(aOld, aNew, nNew) ){

  196700.         if( pTab->abPK[i]==0 ) bRequired = 1;

  196701.         memcpy(aOut, aOld, nOld);

  196702.         aOut += nOld;

  196703.       }else{

  196704.         *(aOut++) = '\0';

  196705.       }

  196706.     }

  196707. 

  196708.     if( !bRequired ) return 0;

  196709.   }

  196710. 

  196711.   /* Write the new.* vector */

  196712.   aOld1 = aOldRecord1;

  196713.   aOld2 = aOldRecord2;

  196714.   aNew1 = aNewRecord1;

  196715.   aNew2 = aNewRecord2;

  196716.   for(i=0; i<pTab->nCol; i++){

  196717.     int nOld;

  196718.     u8 *aOld;

  196719.     int nNew;

  196720.     u8 *aNew;

  196721. 

  196722.     aOld = sessionMergeValue(&aOld1, &aOld2, &nOld);

  196723.     aNew = sessionMergeValue(&aNew1, &aNew2, &nNew);

  196724.     if( bPatchset==0 

  196725.      && (pTab->abPK[i] || (nOld==nNew && 0==memcmp(aOld, aNew, nNew))) 

  196726.     ){

  196727.       *(aOut++) = '\0';

  196728.     }else{

  196729.       memcpy(aOut, aNew, nNew);

  196730.       aOut += nNew;

  196731.     }

  196732.   }

  196733. 

  196734.   *paOut = aOut;

  196735.   return 1;

  196736. }

  196737. 

  196738. /*

  196739. ** This function is only called from within a pre-update-hook callback.

  196740. ** It determines if the current pre-update-hook change affects the same row

  196741. ** as the change stored in argument pChange. If so, it returns true. Otherwise

  196742. ** if the pre-update-hook does not affect the same row as pChange, it returns

  196743. ** false.

  196744. */

  196745. static int sessionPreupdateEqual(

  196746.   sqlite3_session *pSession,      /* Session object that owns SessionTable */

  196747.   SessionTable *pTab,             /* Table associated with change */

  196748.   SessionChange *pChange,         /* Change to compare to */

  196749.   int op                          /* Current pre-update operation */

  196750. ){

  196751.   int iCol;                       /* Used to iterate through columns */

  196752.   u8 *a = pChange->aRecord;       /* Cursor used to scan change record */

  196753. 

  196754.   assert( op==SQLITE_INSERT || op==SQLITE_UPDATE || op==SQLITE_DELETE );

  196755.   for(iCol=0; iCol<pTab->nCol; iCol++){

  196756.     if( !pTab->abPK[iCol] ){

  196757.       a += sessionSerialLen(a);

  196758.     }else{

  196759.       sqlite3_value *pVal;        /* Value returned by preupdate_new/old */

  196760.       int rc;                     /* Error code from preupdate_new/old */

  196761.       int eType = *a++;           /* Type of value from change record */

  196762. 

  196763.       /* The following calls to preupdate_new() and preupdate_old() can not

  196764.       ** fail. This is because they cache their return values, and by the

  196765.       ** time control flows to here they have already been called once from

  196766.       ** within sessionPreupdateHash(). The first two asserts below verify

  196767.       ** this (that the method has already been called). */

  196768.       if( op==SQLITE_INSERT ){

  196769.         /* assert( db->pPreUpdate->pNewUnpacked || db->pPreUpdate->aNew ); */

  196770.         rc = pSession->hook.xNew(pSession->hook.pCtx, iCol, &pVal);

  196771.       }else{

  196772.         /* assert( db->pPreUpdate->pUnpacked ); */

  196773.         rc = pSession->hook.xOld(pSession->hook.pCtx, iCol, &pVal);

  196774.       }

  196775.       assert( rc==SQLITE_OK );

  196776.       if( sqlite3_value_type(pVal)!=eType ) return 0;

  196777. 

  196778.       /* A SessionChange object never has a NULL value in a PK column */

  196779.       assert( eType==SQLITE_INTEGER || eType==SQLITE_FLOAT

  196780.            || eType==SQLITE_BLOB    || eType==SQLITE_TEXT

  196781.       );

  196782. 

  196783.       if( eType==SQLITE_INTEGER || eType==SQLITE_FLOAT ){

  196784.         i64 iVal = sessionGetI64(a);

  196785.         a += 8;

  196786.         if( eType==SQLITE_INTEGER ){

  196787.           if( sqlite3_value_int64(pVal)!=iVal ) return 0;

  196788.         }else{

  196789.           double rVal;

  196790.           assert( sizeof(iVal)==8 && sizeof(rVal)==8 );

  196791.           memcpy(&rVal, &iVal, 8);

  196792.           if( sqlite3_value_double(pVal)!=rVal ) return 0;

  196793.         }

  196794.       }else{

  196795.         int n;

  196796.         const u8 *z;

  196797.         a += sessionVarintGet(a, &n);

  196798.         if( sqlite3_value_bytes(pVal)!=n ) return 0;

  196799.         if( eType==SQLITE_TEXT ){

  196800.           z = sqlite3_value_text(pVal);

  196801.         }else{

  196802.           z = sqlite3_value_blob(pVal);

  196803.         }

  196804.         if( n>0 && memcmp(a, z, n) ) return 0;

  196805.         a += n;

  196806.       }

  196807.     }

  196808.   }

  196809. 

  196810.   return 1;

  196811. }

  196812. 

  196813. /*

  196814. ** If required, grow the hash table used to store changes on table pTab 

  196815. ** (part of the session pSession). If a fatal OOM error occurs, set the

  196816. ** session object to failed and return SQLITE_ERROR. Otherwise, return

  196817. ** SQLITE_OK.

  196818. **

  196819. ** It is possible that a non-fatal OOM error occurs in this function. In

  196820. ** that case the hash-table does not grow, but SQLITE_OK is returned anyway.

  196821. ** Growing the hash table in this case is a performance optimization only,

  196822. ** it is not required for correct operation.

  196823. */

  196824. static int sessionGrowHash(int bPatchset, SessionTable *pTab){

  196825.   if( pTab->nChange==0 || pTab->nEntry>=(pTab->nChange/2) ){

  196826.     int i;

  196827.     SessionChange **apNew;

  196828.     sqlite3_int64 nNew = 2*(sqlite3_int64)(pTab->nChange ? pTab->nChange : 128);

  196829. 

  196830.     apNew = (SessionChange **)sqlite3_malloc64(sizeof(SessionChange *) * nNew);

  196831.     if( apNew==0 ){

  196832.       if( pTab->nChange==0 ){

  196833.         return SQLITE_ERROR;

  196834.       }

  196835.       return SQLITE_OK;

  196836.     }

  196837.     memset(apNew, 0, sizeof(SessionChange *) * nNew);

  196838. 

  196839.     for(i=0; i<pTab->nChange; i++){

  196840.       SessionChange *p;

  196841.       SessionChange *pNext;

  196842.       for(p=pTab->apChange[i]; p; p=pNext){

  196843.         int bPkOnly = (p->op==SQLITE_DELETE && bPatchset);

  196844.         int iHash = sessionChangeHash(pTab, bPkOnly, p->aRecord, nNew);

  196845.         pNext = p->pNext;

  196846.         p->pNext = apNew[iHash];

  196847.         apNew[iHash] = p;

  196848.       }

  196849.     }

  196850. 

  196851.     sqlite3_free(pTab->apChange);

  196852.     pTab->nChange = nNew;

  196853.     pTab->apChange = apNew;

  196854.   }

  196855. 

  196856.   return SQLITE_OK;

  196857. }

  196858. 

  196859. /*

  196860. ** This function queries the database for the names of the columns of table

  196861. ** zThis, in schema zDb.

  196862. **

  196863. ** Otherwise, if they are not NULL, variable *pnCol is set to the number

  196864. ** of columns in the database table and variable *pzTab is set to point to a

  196865. ** nul-terminated copy of the table name. *pazCol (if not NULL) is set to

  196866. ** point to an array of pointers to column names. And *pabPK (again, if not

  196867. ** NULL) is set to point to an array of booleans - true if the corresponding

  196868. ** column is part of the primary key.

  196869. **

  196870. ** For example, if the table is declared as:

  196871. **

  196872. **     CREATE TABLE tbl1(w, x, y, z, PRIMARY KEY(w, z));

  196873. **

  196874. ** Then the four output variables are populated as follows:

  196875. **

  196876. **     *pnCol  = 4

  196877. **     *pzTab  = "tbl1"

  196878. **     *pazCol = {"w", "x", "y", "z"}

  196879. **     *pabPK  = {1, 0, 0, 1}

  196880. **

  196881. ** All returned buffers are part of the same single allocation, which must

  196882. ** be freed using sqlite3_free() by the caller

  196883. */

  196884. static int sessionTableInfo(

  196885.   sqlite3 *db,                    /* Database connection */

  196886.   const char *zDb,                /* Name of attached database (e.g. "main") */

  196887.   const char *zThis,              /* Table name */

  196888.   int *pnCol,                     /* OUT: number of columns */

  196889.   const char **pzTab,             /* OUT: Copy of zThis */

  196890.   const char ***pazCol,           /* OUT: Array of column names for table */

  196891.   u8 **pabPK                      /* OUT: Array of booleans - true for PK col */

  196892. ){

  196893.   char *zPragma;

  196894.   sqlite3_stmt *pStmt;

  196895.   int rc;

  196896.   sqlite3_int64 nByte;

  196897.   int nDbCol = 0;

  196898.   int nThis;

  196899.   int i;

  196900.   u8 *pAlloc = 0;

  196901.   char **azCol = 0;

  196902.   u8 *abPK = 0;

  196903. 

  196904.   assert( pazCol && pabPK );

  196905. 

  196906.   nThis = sqlite3Strlen30(zThis);

  196907.   if( nThis==12 && 0==sqlite3_stricmp("sqlite_stat1", zThis) ){

  196908.     rc = sqlite3_table_column_metadata(db, zDb, zThis, 0, 0, 0, 0, 0, 0);

  196909.     if( rc==SQLITE_OK ){

  196910.       /* For sqlite_stat1, pretend that (tbl,idx) is the PRIMARY KEY. */

  196911.       zPragma = sqlite3_mprintf(

  196912.           "SELECT 0, 'tbl',  '', 0, '', 1     UNION ALL "

  196913.           "SELECT 1, 'idx',  '', 0, '', 2     UNION ALL "

  196914.           "SELECT 2, 'stat', '', 0, '', 0"

  196915.       );

  196916.     }else if( rc==SQLITE_ERROR ){

  196917.       zPragma = sqlite3_mprintf("");

  196918.     }else{

  196919.       return rc;

  196920.     }

  196921.   }else{

  196922.     zPragma = sqlite3_mprintf("PRAGMA '%q'.table_info('%q')", zDb, zThis);

  196923.   }

  196924.   if( !zPragma ) return SQLITE_NOMEM;

  196925. 

  196926.   rc = sqlite3_prepare_v2(db, zPragma, -1, &pStmt, 0);

  196927.   sqlite3_free(zPragma);

  196928.   if( rc!=SQLITE_OK ) return rc;

  196929. 

  196930.   nByte = nThis + 1;

  196931.   while( SQLITE_ROW==sqlite3_step(pStmt) ){

  196932.     nByte += sqlite3_column_bytes(pStmt, 1);

  196933.     nDbCol++;

  196934.   }

  196935.   rc = sqlite3_reset(pStmt);

  196936. 

  196937.   if( rc==SQLITE_OK ){

  196938.     nByte += nDbCol * (sizeof(const char *) + sizeof(u8) + 1);

  196939.     pAlloc = sqlite3_malloc64(nByte);

  196940.     if( pAlloc==0 ){

  196941.       rc = SQLITE_NOMEM;

  196942.     }

  196943.   }

  196944.   if( rc==SQLITE_OK ){

  196945.     azCol = (char **)pAlloc;

  196946.     pAlloc = (u8 *)&azCol[nDbCol];

  196947.     abPK = (u8 *)pAlloc;

  196948.     pAlloc = &abPK[nDbCol];

  196949.     if( pzTab ){

  196950.       memcpy(pAlloc, zThis, nThis+1);

  196951.       *pzTab = (char *)pAlloc;

  196952.       pAlloc += nThis+1;

  196953.     }

  196954.   

  196955.     i = 0;

  196956.     while( SQLITE_ROW==sqlite3_step(pStmt) ){

  196957.       int nName = sqlite3_column_bytes(pStmt, 1);

  196958.       const unsigned char *zName = sqlite3_column_text(pStmt, 1);

  196959.       if( zName==0 ) break;

  196960.       memcpy(pAlloc, zName, nName+1);

  196961.       azCol[i] = (char *)pAlloc;

  196962.       pAlloc += nName+1;

  196963.       abPK[i] = sqlite3_column_int(pStmt, 5);

  196964.       i++;

  196965.     }

  196966.     rc = sqlite3_reset(pStmt);

  196967.   

  196968.   }

  196969. 

  196970.   /* If successful, populate the output variables. Otherwise, zero them and

  196971.   ** free any allocation made. An error code will be returned in this case.

  196972.   */

  196973.   if( rc==SQLITE_OK ){

  196974.     *pazCol = (const char **)azCol;

  196975.     *pabPK = abPK;

  196976.     *pnCol = nDbCol;

  196977.   }else{

  196978.     *pazCol = 0;

  196979.     *pabPK = 0;

  196980.     *pnCol = 0;

  196981.     if( pzTab ) *pzTab = 0;

  196982.     sqlite3_free(azCol);

  196983.   }

  196984.   sqlite3_finalize(pStmt);

  196985.   return rc;

  196986. }

  196987. 

  196988. /*

  196989. ** This function is only called from within a pre-update handler for a

  196990. ** write to table pTab, part of session pSession. If this is the first

  196991. ** write to this table, initalize the SessionTable.nCol, azCol[] and

  196992. ** abPK[] arrays accordingly.

  196993. **

  196994. ** If an error occurs, an error code is stored in sqlite3_session.rc and

  196995. ** non-zero returned. Or, if no error occurs but the table has no primary

  196996. ** key, sqlite3_session.rc is left set to SQLITE_OK and non-zero returned to

  196997. ** indicate that updates on this table should be ignored. SessionTable.abPK 

  196998. ** is set to NULL in this case.

  196999. */

  197000. static int sessionInitTable(sqlite3_session *pSession, SessionTable *pTab){

  197001.   if( pTab->nCol==0 ){

  197002.     u8 *abPK;

  197003.     assert( pTab->azCol==0 || pTab->abPK==0 );

  197004.     pSession->rc = sessionTableInfo(pSession->db, pSession->zDb, 

  197005.         pTab->zName, &pTab->nCol, 0, &pTab->azCol, &abPK

  197006.     );

  197007.     if( pSession->rc==SQLITE_OK ){

  197008.       int i;

  197009.       for(i=0; i<pTab->nCol; i++){

  197010.         if( abPK[i] ){

  197011.           pTab->abPK = abPK;

  197012.           break;

  197013.         }

  197014.       }

  197015.       if( 0==sqlite3_stricmp("sqlite_stat1", pTab->zName) ){

  197016.         pTab->bStat1 = 1;

  197017.       }

  197018.     }

  197019.   }

  197020.   return (pSession->rc || pTab->abPK==0);

  197021. }

  197022. 

  197023. /*

  197024. ** Versions of the four methods in object SessionHook for use with the

  197025. ** sqlite_stat1 table. The purpose of this is to substitute a zero-length

  197026. ** blob each time a NULL value is read from the "idx" column of the

  197027. ** sqlite_stat1 table.

  197028. */

  197029. typedef struct SessionStat1Ctx SessionStat1Ctx;

  197030. struct SessionStat1Ctx {

  197031.   SessionHook hook;

  197032.   sqlite3_session *pSession;

  197033. };

  197034. static int sessionStat1Old(void *pCtx, int iCol, sqlite3_value **ppVal){

  197035.   SessionStat1Ctx *p = (SessionStat1Ctx*)pCtx;

  197036.   sqlite3_value *pVal = 0;

  197037.   int rc = p->hook.xOld(p->hook.pCtx, iCol, &pVal);

  197038.   if( rc==SQLITE_OK && iCol==1 && sqlite3_value_type(pVal)==SQLITE_NULL ){

  197039.     pVal = p->pSession->pZeroBlob;

  197040.   }

  197041.   *ppVal = pVal;

  197042.   return rc;

  197043. }

  197044. static int sessionStat1New(void *pCtx, int iCol, sqlite3_value **ppVal){

  197045.   SessionStat1Ctx *p = (SessionStat1Ctx*)pCtx;

  197046.   sqlite3_value *pVal = 0;

  197047.   int rc = p->hook.xNew(p->hook.pCtx, iCol, &pVal);

  197048.   if( rc==SQLITE_OK && iCol==1 && sqlite3_value_type(pVal)==SQLITE_NULL ){

  197049.     pVal = p->pSession->pZeroBlob;

  197050.   }

  197051.   *ppVal = pVal;

  197052.   return rc;

  197053. }

  197054. static int sessionStat1Count(void *pCtx){

  197055.   SessionStat1Ctx *p = (SessionStat1Ctx*)pCtx;

  197056.   return p->hook.xCount(p->hook.pCtx);

  197057. }

  197058. static int sessionStat1Depth(void *pCtx){

  197059.   SessionStat1Ctx *p = (SessionStat1Ctx*)pCtx;

  197060.   return p->hook.xDepth(p->hook.pCtx);

  197061. }

  197062. 

  197063. 

  197064. /*

  197065. ** This function is only called from with a pre-update-hook reporting a 

  197066. ** change on table pTab (attached to session pSession). The type of change

  197067. ** (UPDATE, INSERT, DELETE) is specified by the first argument.

  197068. **

  197069. ** Unless one is already present or an error occurs, an entry is added

  197070. ** to the changed-rows hash table associated with table pTab.

  197071. */

  197072. static void sessionPreupdateOneChange(

  197073.   int op,                         /* One of SQLITE_UPDATE, INSERT, DELETE */

  197074.   sqlite3_session *pSession,      /* Session object pTab is attached to */

  197075.   SessionTable *pTab              /* Table that change applies to */

  197076. ){

  197077.   int iHash; 

  197078.   int bNull = 0; 

  197079.   int rc = SQLITE_OK;

  197080.   SessionStat1Ctx stat1 = {{0,0,0,0,0},0};

  197081. 

  197082.   if( pSession->rc ) return;

  197083. 

  197084.   /* Load table details if required */

  197085.   if( sessionInitTable(pSession, pTab) ) return;

  197086. 

  197087.   /* Check the number of columns in this xPreUpdate call matches the 

  197088.   ** number of columns in the table.  */

  197089.   if( pTab->nCol!=pSession->hook.xCount(pSession->hook.pCtx) ){

  197090.     pSession->rc = SQLITE_SCHEMA;

  197091.     return;

  197092.   }

  197093. 

  197094.   /* Grow the hash table if required */

  197095.   if( sessionGrowHash(0, pTab) ){

  197096.     pSession->rc = SQLITE_NOMEM;

  197097.     return;

  197098.   }

  197099. 

  197100.   if( pTab->bStat1 ){

  197101.     stat1.hook = pSession->hook;

  197102.     stat1.pSession = pSession;

  197103.     pSession->hook.pCtx = (void*)&stat1;

  197104.     pSession->hook.xNew = sessionStat1New;

  197105.     pSession->hook.xOld = sessionStat1Old;

  197106.     pSession->hook.xCount = sessionStat1Count;

  197107.     pSession->hook.xDepth = sessionStat1Depth;

  197108.     if( pSession->pZeroBlob==0 ){

  197109.       sqlite3_value *p = sqlite3ValueNew(0);

  197110.       if( p==0 ){

  197111.         rc = SQLITE_NOMEM;

  197112.         goto error_out;

  197113.       }

  197114.       sqlite3ValueSetStr(p, 0, "", 0, SQLITE_STATIC);

  197115.       pSession->pZeroBlob = p;

  197116.     }

  197117.   }

  197118. 

  197119.   /* Calculate the hash-key for this change. If the primary key of the row

  197120.   ** includes a NULL value, exit early. Such changes are ignored by the

  197121.   ** session module. */

  197122.   rc = sessionPreupdateHash(pSession, pTab, op==SQLITE_INSERT, &iHash, &bNull);

  197123.   if( rc!=SQLITE_OK ) goto error_out;

  197124. 

  197125.   if( bNull==0 ){

  197126.     /* Search the hash table for an existing record for this row. */

  197127.     SessionChange *pC;

  197128.     for(pC=pTab->apChange[iHash]; pC; pC=pC->pNext){

  197129.       if( sessionPreupdateEqual(pSession, pTab, pC, op) ) break;

  197130.     }

  197131. 

  197132.     if( pC==0 ){

  197133.       /* Create a new change object containing all the old values (if

  197134.       ** this is an SQLITE_UPDATE or SQLITE_DELETE), or just the PK

  197135.       ** values (if this is an INSERT). */

  197136.       SessionChange *pChange; /* New change object */

  197137.       sqlite3_int64 nByte;    /* Number of bytes to allocate */

  197138.       int i;                  /* Used to iterate through columns */

  197139.   

  197140.       assert( rc==SQLITE_OK );

  197141.       pTab->nEntry++;

  197142.   

  197143.       /* Figure out how large an allocation is required */

  197144.       nByte = sizeof(SessionChange);

  197145.       for(i=0; i<pTab->nCol; i++){

  197146.         sqlite3_value *p = 0;

  197147.         if( op!=SQLITE_INSERT ){

  197148.           TESTONLY(int trc = ) pSession->hook.xOld(pSession->hook.pCtx, i, &p);

  197149.           assert( trc==SQLITE_OK );

  197150.         }else if( pTab->abPK[i] ){

  197151.           TESTONLY(int trc = ) pSession->hook.xNew(pSession->hook.pCtx, i, &p);

  197152.           assert( trc==SQLITE_OK );

  197153.         }

  197154. 

  197155.         /* This may fail if SQLite value p contains a utf-16 string that must

  197156.         ** be converted to utf-8 and an OOM error occurs while doing so. */

  197157.         rc = sessionSerializeValue(0, p, &nByte);

  197158.         if( rc!=SQLITE_OK ) goto error_out;

  197159.       }

  197160.   

  197161.       /* Allocate the change object */

  197162.       pChange = (SessionChange *)sqlite3_malloc64(nByte);

  197163.       if( !pChange ){

  197164.         rc = SQLITE_NOMEM;

  197165.         goto error_out;

  197166.       }else{

  197167.         memset(pChange, 0, sizeof(SessionChange));

  197168.         pChange->aRecord = (u8 *)&pChange[1];

  197169.       }

  197170.   

  197171.       /* Populate the change object. None of the preupdate_old(),

  197172.       ** preupdate_new() or SerializeValue() calls below may fail as all

  197173.       ** required values and encodings have already been cached in memory.

  197174.       ** It is not possible for an OOM to occur in this block. */

  197175.       nByte = 0;

  197176.       for(i=0; i<pTab->nCol; i++){

  197177.         sqlite3_value *p = 0;

  197178.         if( op!=SQLITE_INSERT ){

  197179.           pSession->hook.xOld(pSession->hook.pCtx, i, &p);

  197180.         }else if( pTab->abPK[i] ){

  197181.           pSession->hook.xNew(pSession->hook.pCtx, i, &p);

  197182.         }

  197183.         sessionSerializeValue(&pChange->aRecord[nByte], p, &nByte);

  197184.       }

  197185. 

  197186.       /* Add the change to the hash-table */

  197187.       if( pSession->bIndirect || pSession->hook.xDepth(pSession->hook.pCtx) ){

  197188.         pChange->bIndirect = 1;

  197189.       }

  197190.       pChange->nRecord = nByte;

  197191.       pChange->op = op;

  197192.       pChange->pNext = pTab->apChange[iHash];

  197193.       pTab->apChange[iHash] = pChange;

  197194. 

  197195.     }else if( pC->bIndirect ){

  197196.       /* If the existing change is considered "indirect", but this current

  197197.       ** change is "direct", mark the change object as direct. */

  197198.       if( pSession->hook.xDepth(pSession->hook.pCtx)==0 

  197199.        && pSession->bIndirect==0 

  197200.       ){

  197201.         pC->bIndirect = 0;

  197202.       }

  197203.     }

  197204.   }

  197205. 

  197206.   /* If an error has occurred, mark the session object as failed. */

  197207.  error_out:

  197208.   if( pTab->bStat1 ){

  197209.     pSession->hook = stat1.hook;

  197210.   }

  197211.   if( rc!=SQLITE_OK ){

  197212.     pSession->rc = rc;

  197213.   }

  197214. }

  197215. 

  197216. static int sessionFindTable(

  197217.   sqlite3_session *pSession, 

  197218.   const char *zName,

  197219.   SessionTable **ppTab

  197220. ){

  197221.   int rc = SQLITE_OK;

  197222.   int nName = sqlite3Strlen30(zName);

  197223.   SessionTable *pRet;

  197224. 

  197225.   /* Search for an existing table */

  197226.   for(pRet=pSession->pTable; pRet; pRet=pRet->pNext){

  197227.     if( 0==sqlite3_strnicmp(pRet->zName, zName, nName+1) ) break;

  197228.   }

  197229. 

  197230.   if( pRet==0 && pSession->bAutoAttach ){

  197231.     /* If there is a table-filter configured, invoke it. If it returns 0,

  197232.     ** do not automatically add the new table. */

  197233.     if( pSession->xTableFilter==0

  197234.      || pSession->xTableFilter(pSession->pFilterCtx, zName) 

  197235.     ){

  197236.       rc = sqlite3session_attach(pSession, zName);

  197237.       if( rc==SQLITE_OK ){

  197238.         for(pRet=pSession->pTable; pRet->pNext; pRet=pRet->pNext);

  197239.         assert( 0==sqlite3_strnicmp(pRet->zName, zName, nName+1) );

  197240.       }

  197241.     }

  197242.   }

  197243. 

  197244.   assert( rc==SQLITE_OK || pRet==0 );

  197245.   *ppTab = pRet;

  197246.   return rc;

  197247. }

  197248. 

  197249. /*

  197250. ** The 'pre-update' hook registered by this module with SQLite databases.

  197251. */

  197252. static void xPreUpdate(

  197253.   void *pCtx,                     /* Copy of third arg to preupdate_hook() */

  197254.   sqlite3 *db,                    /* Database handle */

  197255.   int op,                         /* SQLITE_UPDATE, DELETE or INSERT */

  197256.   char const *zDb,                /* Database name */

  197257.   char const *zName,              /* Table name */

  197258.   sqlite3_int64 iKey1,            /* Rowid of row about to be deleted/updated */

  197259.   sqlite3_int64 iKey2             /* New rowid value (for a rowid UPDATE) */

  197260. ){

  197261.   sqlite3_session *pSession;

  197262.   int nDb = sqlite3Strlen30(zDb);

  197263. 

  197264.   assert( sqlite3_mutex_held(db->mutex) );

  197265. 

  197266.   for(pSession=(sqlite3_session *)pCtx; pSession; pSession=pSession->pNext){

  197267.     SessionTable *pTab;

  197268. 

  197269.     /* If this session is attached to a different database ("main", "temp" 

  197270.     ** etc.), or if it is not currently enabled, there is nothing to do. Skip 

  197271.     ** to the next session object attached to this database. */

  197272.     if( pSession->bEnable==0 ) continue;

  197273.     if( pSession->rc ) continue;

  197274.     if( sqlite3_strnicmp(zDb, pSession->zDb, nDb+1) ) continue;

  197275. 

  197276.     pSession->rc = sessionFindTable(pSession, zName, &pTab);

  197277.     if( pTab ){

  197278.       assert( pSession->rc==SQLITE_OK );

  197279.       sessionPreupdateOneChange(op, pSession, pTab);

  197280.       if( op==SQLITE_UPDATE ){

  197281.         sessionPreupdateOneChange(SQLITE_INSERT, pSession, pTab);

  197282.       }

  197283.     }

  197284.   }

  197285. }

  197286. 

  197287. /*

  197288. ** The pre-update hook implementations.

  197289. */

  197290. static int sessionPreupdateOld(void *pCtx, int iVal, sqlite3_value **ppVal){

  197291.   return sqlite3_preupdate_old((sqlite3*)pCtx, iVal, ppVal);

  197292. }

  197293. static int sessionPreupdateNew(void *pCtx, int iVal, sqlite3_value **ppVal){

  197294.   return sqlite3_preupdate_new((sqlite3*)pCtx, iVal, ppVal);

  197295. }

  197296. static int sessionPreupdateCount(void *pCtx){

  197297.   return sqlite3_preupdate_count((sqlite3*)pCtx);

  197298. }

  197299. static int sessionPreupdateDepth(void *pCtx){

  197300.   return sqlite3_preupdate_depth((sqlite3*)pCtx);

  197301. }

  197302. 

  197303. /*

  197304. ** Install the pre-update hooks on the session object passed as the only

  197305. ** argument.

  197306. */

  197307. static void sessionPreupdateHooks(

  197308.   sqlite3_session *pSession

  197309. ){

  197310.   pSession->hook.pCtx = (void*)pSession->db;

  197311.   pSession->hook.xOld = sessionPreupdateOld;

  197312.   pSession->hook.xNew = sessionPreupdateNew;

  197313.   pSession->hook.xCount = sessionPreupdateCount;

  197314.   pSession->hook.xDepth = sessionPreupdateDepth;

  197315. }

  197316. 

  197317. typedef struct SessionDiffCtx SessionDiffCtx;

  197318. struct SessionDiffCtx {

  197319.   sqlite3_stmt *pStmt;

  197320.   int nOldOff;

  197321. };

  197322. 

  197323. /*

  197324. ** The diff hook implementations.

  197325. */

  197326. static int sessionDiffOld(void *pCtx, int iVal, sqlite3_value **ppVal){

  197327.   SessionDiffCtx *p = (SessionDiffCtx*)pCtx;

  197328.   *ppVal = sqlite3_column_value(p->pStmt, iVal+p->nOldOff);

  197329.   return SQLITE_OK;

  197330. }

  197331. static int sessionDiffNew(void *pCtx, int iVal, sqlite3_value **ppVal){

  197332.   SessionDiffCtx *p = (SessionDiffCtx*)pCtx;

  197333.   *ppVal = sqlite3_column_value(p->pStmt, iVal);

  197334.    return SQLITE_OK;

  197335. }

  197336. static int sessionDiffCount(void *pCtx){

  197337.   SessionDiffCtx *p = (SessionDiffCtx*)pCtx;

  197338.   return p->nOldOff ? p->nOldOff : sqlite3_column_count(p->pStmt);

  197339. }

  197340. static int sessionDiffDepth(void *pCtx){

  197341.   return 0;

  197342. }

  197343. 

  197344. /*

  197345. ** Install the diff hooks on the session object passed as the only

  197346. ** argument.

  197347. */

  197348. static void sessionDiffHooks(

  197349.   sqlite3_session *pSession,

  197350.   SessionDiffCtx *pDiffCtx

  197351. ){

  197352.   pSession->hook.pCtx = (void*)pDiffCtx;

  197353.   pSession->hook.xOld = sessionDiffOld;

  197354.   pSession->hook.xNew = sessionDiffNew;

  197355.   pSession->hook.xCount = sessionDiffCount;

  197356.   pSession->hook.xDepth = sessionDiffDepth;

  197357. }

  197358. 

  197359. static char *sessionExprComparePK(

  197360.   int nCol,

  197361.   const char *zDb1, const char *zDb2, 

  197362.   const char *zTab,

  197363.   const char **azCol, u8 *abPK

  197364. ){

  197365.   int i;

  197366.   const char *zSep = "";

  197367.   char *zRet = 0;

  197368. 

  197369.   for(i=0; i<nCol; i++){

  197370.     if( abPK[i] ){

  197371.       zRet = sqlite3_mprintf("%z%s\"%w\".\"%w\".\"%w\"=\"%w\".\"%w\".\"%w\"",

  197372.           zRet, zSep, zDb1, zTab, azCol[i], zDb2, zTab, azCol[i]

  197373.       );

  197374.       zSep = " AND ";

  197375.       if( zRet==0 ) break;

  197376.     }

  197377.   }

  197378. 

  197379.   return zRet;

  197380. }

  197381. 

  197382. static char *sessionExprCompareOther(

  197383.   int nCol,

  197384.   const char *zDb1, const char *zDb2, 

  197385.   const char *zTab,

  197386.   const char **azCol, u8 *abPK

  197387. ){

  197388.   int i;

  197389.   const char *zSep = "";

  197390.   char *zRet = 0;

  197391.   int bHave = 0;

  197392. 

  197393.   for(i=0; i<nCol; i++){

  197394.     if( abPK[i]==0 ){

  197395.       bHave = 1;

  197396.       zRet = sqlite3_mprintf(

  197397.           "%z%s\"%w\".\"%w\".\"%w\" IS NOT \"%w\".\"%w\".\"%w\"",

  197398.           zRet, zSep, zDb1, zTab, azCol[i], zDb2, zTab, azCol[i]

  197399.       );

  197400.       zSep = " OR ";

  197401.       if( zRet==0 ) break;

  197402.     }

  197403.   }

  197404. 

  197405.   if( bHave==0 ){

  197406.     assert( zRet==0 );

  197407.     zRet = sqlite3_mprintf("0");

  197408.   }

  197409. 

  197410.   return zRet;

  197411. }

  197412. 

  197413. static char *sessionSelectFindNew(

  197414.   int nCol,

  197415.   const char *zDb1,      /* Pick rows in this db only */

  197416.   const char *zDb2,      /* But not in this one */

  197417.   const char *zTbl,      /* Table name */

  197418.   const char *zExpr

  197419. ){

  197420.   char *zRet = sqlite3_mprintf(

  197421.       "SELECT * FROM \"%w\".\"%w\" WHERE NOT EXISTS ("

  197422.       "  SELECT 1 FROM \"%w\".\"%w\" WHERE %s"

  197423.       ")",

  197424.       zDb1, zTbl, zDb2, zTbl, zExpr

  197425.   );

  197426.   return zRet;

  197427. }

  197428. 

  197429. static int sessionDiffFindNew(

  197430.   int op,

  197431.   sqlite3_session *pSession,

  197432.   SessionTable *pTab,

  197433.   const char *zDb1,

  197434.   const char *zDb2,

  197435.   char *zExpr

  197436. ){

  197437.   int rc = SQLITE_OK;

  197438.   char *zStmt = sessionSelectFindNew(pTab->nCol, zDb1, zDb2, pTab->zName,zExpr);

  197439. 

  197440.   if( zStmt==0 ){

  197441.     rc = SQLITE_NOMEM;

  197442.   }else{

  197443.     sqlite3_stmt *pStmt;

  197444.     rc = sqlite3_prepare(pSession->db, zStmt, -1, &pStmt, 0);

  197445.     if( rc==SQLITE_OK ){

  197446.       SessionDiffCtx *pDiffCtx = (SessionDiffCtx*)pSession->hook.pCtx;

  197447.       pDiffCtx->pStmt = pStmt;

  197448.       pDiffCtx->nOldOff = 0;

  197449.       while( SQLITE_ROW==sqlite3_step(pStmt) ){

  197450.         sessionPreupdateOneChange(op, pSession, pTab);

  197451.       }

  197452.       rc = sqlite3_finalize(pStmt);

  197453.     }

  197454.     sqlite3_free(zStmt);

  197455.   }

  197456. 

  197457.   return rc;

  197458. }

  197459. 

  197460. static int sessionDiffFindModified(

  197461.   sqlite3_session *pSession, 

  197462.   SessionTable *pTab, 

  197463.   const char *zFrom, 

  197464.   const char *zExpr

  197465. ){

  197466.   int rc = SQLITE_OK;

  197467. 

  197468.   char *zExpr2 = sessionExprCompareOther(pTab->nCol,

  197469.       pSession->zDb, zFrom, pTab->zName, pTab->azCol, pTab->abPK

  197470.   );

  197471.   if( zExpr2==0 ){

  197472.     rc = SQLITE_NOMEM;

  197473.   }else{

  197474.     char *zStmt = sqlite3_mprintf(

  197475.         "SELECT * FROM \"%w\".\"%w\", \"%w\".\"%w\" WHERE %s AND (%z)",

  197476.         pSession->zDb, pTab->zName, zFrom, pTab->zName, zExpr, zExpr2

  197477.     );

  197478.     if( zStmt==0 ){

  197479.       rc = SQLITE_NOMEM;

  197480.     }else{

  197481.       sqlite3_stmt *pStmt;

  197482.       rc = sqlite3_prepare(pSession->db, zStmt, -1, &pStmt, 0);

  197483. 

  197484.       if( rc==SQLITE_OK ){

  197485.         SessionDiffCtx *pDiffCtx = (SessionDiffCtx*)pSession->hook.pCtx;

  197486.         pDiffCtx->pStmt = pStmt;

  197487.         pDiffCtx->nOldOff = pTab->nCol;

  197488.         while( SQLITE_ROW==sqlite3_step(pStmt) ){

  197489.           sessionPreupdateOneChange(SQLITE_UPDATE, pSession, pTab);

  197490.         }

  197491.         rc = sqlite3_finalize(pStmt);

  197492.       }

  197493.       sqlite3_free(zStmt);

  197494.     }

  197495.   }

  197496. 

  197497.   return rc;

  197498. }

  197499. 

  197500. SQLITE_API int sqlite3session_diff(

  197501.   sqlite3_session *pSession,

  197502.   const char *zFrom,

  197503.   const char *zTbl,

  197504.   char **pzErrMsg

  197505. ){

  197506.   const char *zDb = pSession->zDb;

  197507.   int rc = pSession->rc;

  197508.   SessionDiffCtx d;

  197509. 

  197510.   memset(&d, 0, sizeof(d));

  197511.   sessionDiffHooks(pSession, &d);

  197512. 

  197513.   sqlite3_mutex_enter(sqlite3_db_mutex(pSession->db));

  197514.   if( pzErrMsg ) *pzErrMsg = 0;

  197515.   if( rc==SQLITE_OK ){

  197516.     char *zExpr = 0;

  197517.     sqlite3 *db = pSession->db;

  197518.     SessionTable *pTo;            /* Table zTbl */

  197519. 

  197520.     /* Locate and if necessary initialize the target table object */

  197521.     rc = sessionFindTable(pSession, zTbl, &pTo);

  197522.     if( pTo==0 ) goto diff_out;

  197523.     if( sessionInitTable(pSession, pTo) ){

  197524.       rc = pSession->rc;

  197525.       goto diff_out;

  197526.     }

  197527. 

  197528.     /* Check the table schemas match */

  197529.     if( rc==SQLITE_OK ){

  197530.       int bHasPk = 0;

  197531.       int bMismatch = 0;

  197532.       int nCol;                   /* Columns in zFrom.zTbl */

  197533.       u8 *abPK;

  197534.       const char **azCol = 0;

  197535.       rc = sessionTableInfo(db, zFrom, zTbl, &nCol, 0, &azCol, &abPK);

  197536.       if( rc==SQLITE_OK ){

  197537.         if( pTo->nCol!=nCol ){

  197538.           bMismatch = 1;

  197539.         }else{

  197540.           int i;

  197541.           for(i=0; i<nCol; i++){

  197542.             if( pTo->abPK[i]!=abPK[i] ) bMismatch = 1;

  197543.             if( sqlite3_stricmp(azCol[i], pTo->azCol[i]) ) bMismatch = 1;

  197544.             if( abPK[i] ) bHasPk = 1;

  197545.           }

  197546.         }

  197547.       }

  197548.       sqlite3_free((char*)azCol);

  197549.       if( bMismatch ){

  197550.         if( pzErrMsg ){

  197551.           *pzErrMsg = sqlite3_mprintf("table schemas do not match");

  197552.         }

  197553.         rc = SQLITE_SCHEMA;

  197554.       }

  197555.       if( bHasPk==0 ){

  197556.         /* Ignore tables with no primary keys */

  197557.         goto diff_out;

  197558.       }

  197559.     }

  197560. 

  197561.     if( rc==SQLITE_OK ){

  197562.       zExpr = sessionExprComparePK(pTo->nCol, 

  197563.           zDb, zFrom, pTo->zName, pTo->azCol, pTo->abPK

  197564.       );

  197565.     }

  197566. 

  197567.     /* Find new rows */

  197568.     if( rc==SQLITE_OK ){

  197569.       rc = sessionDiffFindNew(SQLITE_INSERT, pSession, pTo, zDb, zFrom, zExpr);

  197570.     }

  197571. 

  197572.     /* Find old rows */

  197573.     if( rc==SQLITE_OK ){

  197574.       rc = sessionDiffFindNew(SQLITE_DELETE, pSession, pTo, zFrom, zDb, zExpr);

  197575.     }

  197576. 

  197577.     /* Find modified rows */

  197578.     if( rc==SQLITE_OK ){

  197579.       rc = sessionDiffFindModified(pSession, pTo, zFrom, zExpr);

  197580.     }

  197581. 

  197582.     sqlite3_free(zExpr);

  197583.   }

  197584. 

  197585.  diff_out:

  197586.   sessionPreupdateHooks(pSession);

  197587.   sqlite3_mutex_leave(sqlite3_db_mutex(pSession->db));

  197588.   return rc;

  197589. }

  197590. 

  197591. /*

  197592. ** Create a session object. This session object will record changes to

  197593. ** database zDb attached to connection db.

  197594. */

  197595. SQLITE_API int sqlite3session_create(

  197596.   sqlite3 *db,                    /* Database handle */

  197597.   const char *zDb,                /* Name of db (e.g. "main") */

  197598.   sqlite3_session **ppSession     /* OUT: New session object */

  197599. ){

  197600.   sqlite3_session *pNew;          /* Newly allocated session object */

  197601.   sqlite3_session *pOld;          /* Session object already attached to db */

  197602.   int nDb = sqlite3Strlen30(zDb); /* Length of zDb in bytes */

  197603. 

  197604.   /* Zero the output value in case an error occurs. */

  197605.   *ppSession = 0;

  197606. 

  197607.   /* Allocate and populate the new session object. */

  197608.   pNew = (sqlite3_session *)sqlite3_malloc64(sizeof(sqlite3_session) + nDb + 1);

  197609.   if( !pNew ) return SQLITE_NOMEM;

  197610.   memset(pNew, 0, sizeof(sqlite3_session));

  197611.   pNew->db = db;

  197612.   pNew->zDb = (char *)&pNew[1];

  197613.   pNew->bEnable = 1;

  197614.   memcpy(pNew->zDb, zDb, nDb+1);

  197615.   sessionPreupdateHooks(pNew);

  197616. 

  197617.   /* Add the new session object to the linked list of session objects 

  197618.   ** attached to database handle $db. Do this under the cover of the db

  197619.   ** handle mutex.  */

  197620.   sqlite3_mutex_enter(sqlite3_db_mutex(db));

  197621.   pOld = (sqlite3_session*)sqlite3_preupdate_hook(db, xPreUpdate, (void*)pNew);

  197622.   pNew->pNext = pOld;

  197623.   sqlite3_mutex_leave(sqlite3_db_mutex(db));

  197624. 

  197625.   *ppSession = pNew;

  197626.   return SQLITE_OK;

  197627. }

  197628. 

  197629. /*

  197630. ** Free the list of table objects passed as the first argument. The contents

  197631. ** of the changed-rows hash tables are also deleted.

  197632. */

  197633. static void sessionDeleteTable(SessionTable *pList){

  197634.   SessionTable *pNext;

  197635.   SessionTable *pTab;

  197636. 

  197637.   for(pTab=pList; pTab; pTab=pNext){

  197638.     int i;

  197639.     pNext = pTab->pNext;

  197640.     for(i=0; i<pTab->nChange; i++){

  197641.       SessionChange *p;

  197642.       SessionChange *pNextChange;

  197643.       for(p=pTab->apChange[i]; p; p=pNextChange){

  197644.         pNextChange = p->pNext;

  197645.         sqlite3_free(p);

  197646.       }

  197647.     }

  197648.     sqlite3_free((char*)pTab->azCol);  /* cast works around VC++ bug */

  197649.     sqlite3_free(pTab->apChange);

  197650.     sqlite3_free(pTab);

  197651.   }

  197652. }

  197653. 

  197654. /*

  197655. ** Delete a session object previously allocated using sqlite3session_create().

  197656. */

  197657. SQLITE_API void sqlite3session_delete(sqlite3_session *pSession){

  197658.   sqlite3 *db = pSession->db;

  197659.   sqlite3_session *pHead;

  197660.   sqlite3_session **pp;

  197661. 

  197662.   /* Unlink the session from the linked list of sessions attached to the

  197663.   ** database handle. Hold the db mutex while doing so.  */

  197664.   sqlite3_mutex_enter(sqlite3_db_mutex(db));

  197665.   pHead = (sqlite3_session*)sqlite3_preupdate_hook(db, 0, 0);

  197666.   for(pp=&pHead; ALWAYS((*pp)!=0); pp=&((*pp)->pNext)){

  197667.     if( (*pp)==pSession ){

  197668.       *pp = (*pp)->pNext;

  197669.       if( pHead ) sqlite3_preupdate_hook(db, xPreUpdate, (void*)pHead);

  197670.       break;

  197671.     }

  197672.   }

  197673.   sqlite3_mutex_leave(sqlite3_db_mutex(db));

  197674.   sqlite3ValueFree(pSession->pZeroBlob);

  197675. 

  197676.   /* Delete all attached table objects. And the contents of their 

  197677.   ** associated hash-tables. */

  197678.   sessionDeleteTable(pSession->pTable);

  197679. 

  197680.   /* Free the session object itself. */

  197681.   sqlite3_free(pSession);

  197682. }

  197683. 

  197684. /*

  197685. ** Set a table filter on a Session Object.

  197686. */

  197687. SQLITE_API void sqlite3session_table_filter(

  197688.   sqlite3_session *pSession, 

  197689.   int(*xFilter)(void*, const char*),

  197690.   void *pCtx                      /* First argument passed to xFilter */

  197691. ){

  197692.   pSession->bAutoAttach = 1;

  197693.   pSession->pFilterCtx = pCtx;

  197694.   pSession->xTableFilter = xFilter;

  197695. }

  197696. 

  197697. /*

  197698. ** Attach a table to a session. All subsequent changes made to the table

  197699. ** while the session object is enabled will be recorded.

  197700. **

  197701. ** Only tables that have a PRIMARY KEY defined may be attached. It does

  197702. ** not matter if the PRIMARY KEY is an "INTEGER PRIMARY KEY" (rowid alias)

  197703. ** or not.

  197704. */

  197705. SQLITE_API int sqlite3session_attach(

  197706.   sqlite3_session *pSession,      /* Session object */

  197707.   const char *zName               /* Table name */

  197708. ){

  197709.   int rc = SQLITE_OK;

  197710.   sqlite3_mutex_enter(sqlite3_db_mutex(pSession->db));

  197711. 

  197712.   if( !zName ){

  197713.     pSession->bAutoAttach = 1;

  197714.   }else{

  197715.     SessionTable *pTab;           /* New table object (if required) */

  197716.     int nName;                    /* Number of bytes in string zName */

  197717. 

  197718.     /* First search for an existing entry. If one is found, this call is

  197719.     ** a no-op. Return early. */

  197720.     nName = sqlite3Strlen30(zName);

  197721.     for(pTab=pSession->pTable; pTab; pTab=pTab->pNext){

  197722.       if( 0==sqlite3_strnicmp(pTab->zName, zName, nName+1) ) break;

  197723.     }

  197724. 

  197725.     if( !pTab ){

  197726.       /* Allocate new SessionTable object. */

  197727.       pTab = (SessionTable *)sqlite3_malloc64(sizeof(SessionTable) + nName + 1);

  197728.       if( !pTab ){

  197729.         rc = SQLITE_NOMEM;

  197730.       }else{

  197731.         /* Populate the new SessionTable object and link it into the list.

  197732.         ** The new object must be linked onto the end of the list, not 

  197733.         ** simply added to the start of it in order to ensure that tables

  197734.         ** appear in the correct order when a changeset or patchset is

  197735.         ** eventually generated. */

  197736.         SessionTable **ppTab;

  197737.         memset(pTab, 0, sizeof(SessionTable));

  197738.         pTab->zName = (char *)&pTab[1];

  197739.         memcpy(pTab->zName, zName, nName+1);

  197740.         for(ppTab=&pSession->pTable; *ppTab; ppTab=&(*ppTab)->pNext);

  197741.         *ppTab = pTab;

  197742.       }

  197743.     }

  197744.   }

  197745. 

  197746.   sqlite3_mutex_leave(sqlite3_db_mutex(pSession->db));

  197747.   return rc;

  197748. }

  197749. 

  197750. /*

  197751. ** Ensure that there is room in the buffer to append nByte bytes of data.

  197752. ** If not, use sqlite3_realloc() to grow the buffer so that there is.

  197753. **

  197754. ** If successful, return zero. Otherwise, if an OOM condition is encountered,

  197755. ** set *pRc to SQLITE_NOMEM and return non-zero.

  197756. */

  197757. static int sessionBufferGrow(SessionBuffer *p, size_t nByte, int *pRc){

  197758.   if( *pRc==SQLITE_OK && (size_t)(p->nAlloc-p->nBuf)<nByte ){

  197759.     u8 *aNew;

  197760.     i64 nNew = p->nAlloc ? p->nAlloc : 128;

  197761.     do {

  197762.       nNew = nNew*2;

  197763.     }while( (nNew-p->nBuf)<nByte );

  197764. 

  197765.     aNew = (u8 *)sqlite3_realloc64(p->aBuf, nNew);

  197766.     if( 0==aNew ){

  197767.       *pRc = SQLITE_NOMEM;

  197768.     }else{

  197769.       p->aBuf = aNew;

  197770.       p->nAlloc = nNew;

  197771.     }

  197772.   }

  197773.   return (*pRc!=SQLITE_OK);

  197774. }

  197775. 

  197776. /*

  197777. ** Append the value passed as the second argument to the buffer passed

  197778. ** as the first.

  197779. **

  197780. ** This function is a no-op if *pRc is non-zero when it is called.

  197781. ** Otherwise, if an error occurs, *pRc is set to an SQLite error code

  197782. ** before returning.

  197783. */

  197784. static void sessionAppendValue(SessionBuffer *p, sqlite3_value *pVal, int *pRc){

  197785.   int rc = *pRc;

  197786.   if( rc==SQLITE_OK ){

  197787.     sqlite3_int64 nByte = 0;

  197788.     rc = sessionSerializeValue(0, pVal, &nByte);

  197789.     sessionBufferGrow(p, nByte, &rc);

  197790.     if( rc==SQLITE_OK ){

  197791.       rc = sessionSerializeValue(&p->aBuf[p->nBuf], pVal, 0);

  197792.       p->nBuf += nByte;

  197793.     }else{

  197794.       *pRc = rc;

  197795.     }

  197796.   }

  197797. }

  197798. 

  197799. /*

  197800. ** This function is a no-op if *pRc is other than SQLITE_OK when it is 

  197801. ** called. Otherwise, append a single byte to the buffer. 

  197802. **

  197803. ** If an OOM condition is encountered, set *pRc to SQLITE_NOMEM before

  197804. ** returning.

  197805. */

  197806. static void sessionAppendByte(SessionBuffer *p, u8 v, int *pRc){

  197807.   if( 0==sessionBufferGrow(p, 1, pRc) ){

  197808.     p->aBuf[p->nBuf++] = v;

  197809.   }

  197810. }

  197811. 

  197812. /*

  197813. ** This function is a no-op if *pRc is other than SQLITE_OK when it is 

  197814. ** called. Otherwise, append a single varint to the buffer. 

  197815. **

  197816. ** If an OOM condition is encountered, set *pRc to SQLITE_NOMEM before

  197817. ** returning.

  197818. */

  197819. static void sessionAppendVarint(SessionBuffer *p, int v, int *pRc){

  197820.   if( 0==sessionBufferGrow(p, 9, pRc) ){

  197821.     p->nBuf += sessionVarintPut(&p->aBuf[p->nBuf], v);

  197822.   }

  197823. }

  197824. 

  197825. /*

  197826. ** This function is a no-op if *pRc is other than SQLITE_OK when it is 

  197827. ** called. Otherwise, append a blob of data to the buffer. 

  197828. **

  197829. ** If an OOM condition is encountered, set *pRc to SQLITE_NOMEM before

  197830. ** returning.

  197831. */

  197832. static void sessionAppendBlob(

  197833.   SessionBuffer *p, 

  197834.   const u8 *aBlob, 

  197835.   int nBlob, 

  197836.   int *pRc

  197837. ){

  197838.   if( nBlob>0 && 0==sessionBufferGrow(p, nBlob, pRc) ){

  197839.     memcpy(&p->aBuf[p->nBuf], aBlob, nBlob);

  197840.     p->nBuf += nBlob;

  197841.   }

  197842. }

  197843. 

  197844. /*

  197845. ** This function is a no-op if *pRc is other than SQLITE_OK when it is 

  197846. ** called. Otherwise, append a string to the buffer. All bytes in the string

  197847. ** up to (but not including) the nul-terminator are written to the buffer.

  197848. **

  197849. ** If an OOM condition is encountered, set *pRc to SQLITE_NOMEM before

  197850. ** returning.

  197851. */

  197852. static void sessionAppendStr(

  197853.   SessionBuffer *p, 

  197854.   const char *zStr, 

  197855.   int *pRc

  197856. ){

  197857.   int nStr = sqlite3Strlen30(zStr);

  197858.   if( 0==sessionBufferGrow(p, nStr, pRc) ){

  197859.     memcpy(&p->aBuf[p->nBuf], zStr, nStr);

  197860.     p->nBuf += nStr;

  197861.   }

  197862. }

  197863. 

  197864. /*

  197865. ** This function is a no-op if *pRc is other than SQLITE_OK when it is 

  197866. ** called. Otherwise, append the string representation of integer iVal

  197867. ** to the buffer. No nul-terminator is written.

  197868. **

  197869. ** If an OOM condition is encountered, set *pRc to SQLITE_NOMEM before

  197870. ** returning.

  197871. */

  197872. static void sessionAppendInteger(

  197873.   SessionBuffer *p,               /* Buffer to append to */

  197874.   int iVal,                       /* Value to write the string rep. of */

  197875.   int *pRc                        /* IN/OUT: Error code */

  197876. ){

  197877.   char aBuf[24];

  197878.   sqlite3_snprintf(sizeof(aBuf)-1, aBuf, "%d", iVal);

  197879.   sessionAppendStr(p, aBuf, pRc);

  197880. }

  197881. 

  197882. /*

  197883. ** This function is a no-op if *pRc is other than SQLITE_OK when it is 

  197884. ** called. Otherwise, append the string zStr enclosed in quotes (") and

  197885. ** with any embedded quote characters escaped to the buffer. No 

  197886. ** nul-terminator byte is written.

  197887. **

  197888. ** If an OOM condition is encountered, set *pRc to SQLITE_NOMEM before

  197889. ** returning.

  197890. */

  197891. static void sessionAppendIdent(

  197892.   SessionBuffer *p,               /* Buffer to a append to */

  197893.   const char *zStr,               /* String to quote, escape and append */

  197894.   int *pRc                        /* IN/OUT: Error code */

  197895. ){

  197896.   int nStr = sqlite3Strlen30(zStr)*2 + 2 + 1;

  197897.   if( 0==sessionBufferGrow(p, nStr, pRc) ){

  197898.     char *zOut = (char *)&p->aBuf[p->nBuf];

  197899.     const char *zIn = zStr;

  197900.     *zOut++ = '"';

  197901.     while( *zIn ){

  197902.       if( *zIn=='"' ) *zOut++ = '"';

  197903.       *zOut++ = *(zIn++);

  197904.     }

  197905.     *zOut++ = '"';

  197906.     p->nBuf = (int)((u8 *)zOut - p->aBuf);

  197907.   }

  197908. }

  197909. 

  197910. /*

  197911. ** This function is a no-op if *pRc is other than SQLITE_OK when it is

  197912. ** called. Otherwse, it appends the serialized version of the value stored

  197913. ** in column iCol of the row that SQL statement pStmt currently points

  197914. ** to to the buffer.

  197915. */

  197916. static void sessionAppendCol(

  197917.   SessionBuffer *p,               /* Buffer to append to */

  197918.   sqlite3_stmt *pStmt,            /* Handle pointing to row containing value */

  197919.   int iCol,                       /* Column to read value from */

  197920.   int *pRc                        /* IN/OUT: Error code */

  197921. ){

  197922.   if( *pRc==SQLITE_OK ){

  197923.     int eType = sqlite3_column_type(pStmt, iCol);

  197924.     sessionAppendByte(p, (u8)eType, pRc);

  197925.     if( eType==SQLITE_INTEGER || eType==SQLITE_FLOAT ){

  197926.       sqlite3_int64 i;

  197927.       u8 aBuf[8];

  197928.       if( eType==SQLITE_INTEGER ){

  197929.         i = sqlite3_column_int64(pStmt, iCol);

  197930.       }else{

  197931.         double r = sqlite3_column_double(pStmt, iCol);

  197932.         memcpy(&i, &r, 8);

  197933.       }

  197934.       sessionPutI64(aBuf, i);

  197935.       sessionAppendBlob(p, aBuf, 8, pRc);

  197936.     }

  197937.     if( eType==SQLITE_BLOB || eType==SQLITE_TEXT ){

  197938.       u8 *z;

  197939.       int nByte;

  197940.       if( eType==SQLITE_BLOB ){

  197941.         z = (u8 *)sqlite3_column_blob(pStmt, iCol);

  197942.       }else{

  197943.         z = (u8 *)sqlite3_column_text(pStmt, iCol);

  197944.       }

  197945.       nByte = sqlite3_column_bytes(pStmt, iCol);

  197946.       if( z || (eType==SQLITE_BLOB && nByte==0) ){

  197947.         sessionAppendVarint(p, nByte, pRc);

  197948.         sessionAppendBlob(p, z, nByte, pRc);

  197949.       }else{

  197950.         *pRc = SQLITE_NOMEM;

  197951.       }

  197952.     }

  197953.   }

  197954. }

  197955. 

  197956. /*

  197957. **

  197958. ** This function appends an update change to the buffer (see the comments 

  197959. ** under "CHANGESET FORMAT" at the top of the file). An update change 

  197960. ** consists of:

  197961. **

  197962. **   1 byte:  SQLITE_UPDATE (0x17)

  197963. **   n bytes: old.* record (see RECORD FORMAT)

  197964. **   m bytes: new.* record (see RECORD FORMAT)

  197965. **

  197966. ** The SessionChange object passed as the third argument contains the

  197967. ** values that were stored in the row when the session began (the old.*

  197968. ** values). The statement handle passed as the second argument points

  197969. ** at the current version of the row (the new.* values).

  197970. **

  197971. ** If all of the old.* values are equal to their corresponding new.* value

  197972. ** (i.e. nothing has changed), then no data at all is appended to the buffer.

  197973. **

  197974. ** Otherwise, the old.* record contains all primary key values and the 

  197975. ** original values of any fields that have been modified. The new.* record 

  197976. ** contains the new values of only those fields that have been modified.

  197977. */ 

  197978. static int sessionAppendUpdate(

  197979.   SessionBuffer *pBuf,            /* Buffer to append to */

  197980.   int bPatchset,                  /* True for "patchset", 0 for "changeset" */

  197981.   sqlite3_stmt *pStmt,            /* Statement handle pointing at new row */

  197982.   SessionChange *p,               /* Object containing old values */

  197983.   u8 *abPK                        /* Boolean array - true for PK columns */

  197984. ){

  197985.   int rc = SQLITE_OK;

  197986.   SessionBuffer buf2 = {0,0,0}; /* Buffer to accumulate new.* record in */

  197987.   int bNoop = 1;                /* Set to zero if any values are modified */

  197988.   int nRewind = pBuf->nBuf;     /* Set to zero if any values are modified */

  197989.   int i;                        /* Used to iterate through columns */

  197990.   u8 *pCsr = p->aRecord;        /* Used to iterate through old.* values */

  197991. 

  197992.   sessionAppendByte(pBuf, SQLITE_UPDATE, &rc);

  197993.   sessionAppendByte(pBuf, p->bIndirect, &rc);

  197994.   for(i=0; i<sqlite3_column_count(pStmt); i++){

  197995.     int bChanged = 0;

  197996.     int nAdvance;

  197997.     int eType = *pCsr;

  197998.     switch( eType ){

  197999.       case SQLITE_NULL:

  198000.         nAdvance = 1;

  198001.         if( sqlite3_column_type(pStmt, i)!=SQLITE_NULL ){

  198002.           bChanged = 1;

  198003.         }

  198004.         break;

  198005. 

  198006.       case SQLITE_FLOAT:

  198007.       case SQLITE_INTEGER: {

  198008.         nAdvance = 9;

  198009.         if( eType==sqlite3_column_type(pStmt, i) ){

  198010.           sqlite3_int64 iVal = sessionGetI64(&pCsr[1]);

  198011.           if( eType==SQLITE_INTEGER ){

  198012.             if( iVal==sqlite3_column_int64(pStmt, i) ) break;

  198013.           }else{

  198014.             double dVal;

  198015.             memcpy(&dVal, &iVal, 8);

  198016.             if( dVal==sqlite3_column_double(pStmt, i) ) break;

  198017.           }

  198018.         }

  198019.         bChanged = 1;

  198020.         break;

  198021.       }

  198022. 

  198023.       default: {

  198024.         int n;

  198025.         int nHdr = 1 + sessionVarintGet(&pCsr[1], &n);

  198026.         assert( eType==SQLITE_TEXT || eType==SQLITE_BLOB );

  198027.         nAdvance = nHdr + n;

  198028.         if( eType==sqlite3_column_type(pStmt, i) 

  198029.          && n==sqlite3_column_bytes(pStmt, i) 

  198030.          && (n==0 || 0==memcmp(&pCsr[nHdr], sqlite3_column_blob(pStmt, i), n))

  198031.         ){

  198032.           break;

  198033.         }

  198034.         bChanged = 1;

  198035.       }

  198036.     }

  198037. 

  198038.     /* If at least one field has been modified, this is not a no-op. */

  198039.     if( bChanged ) bNoop = 0;

  198040. 

  198041.     /* Add a field to the old.* record. This is omitted if this modules is

  198042.     ** currently generating a patchset. */

  198043.     if( bPatchset==0 ){

  198044.       if( bChanged || abPK[i] ){

  198045.         sessionAppendBlob(pBuf, pCsr, nAdvance, &rc);

  198046.       }else{

  198047.         sessionAppendByte(pBuf, 0, &rc);

  198048.       }

  198049.     }

  198050. 

  198051.     /* Add a field to the new.* record. Or the only record if currently

  198052.     ** generating a patchset.  */

  198053.     if( bChanged || (bPatchset && abPK[i]) ){

  198054.       sessionAppendCol(&buf2, pStmt, i, &rc);

  198055.     }else{

  198056.       sessionAppendByte(&buf2, 0, &rc);

  198057.     }

  198058. 

  198059.     pCsr += nAdvance;

  198060.   }

  198061. 

  198062.   if( bNoop ){

  198063.     pBuf->nBuf = nRewind;

  198064.   }else{

  198065.     sessionAppendBlob(pBuf, buf2.aBuf, buf2.nBuf, &rc);

  198066.   }

  198067.   sqlite3_free(buf2.aBuf);

  198068. 

  198069.   return rc;

  198070. }

  198071. 

  198072. /*

  198073. ** Append a DELETE change to the buffer passed as the first argument. Use

  198074. ** the changeset format if argument bPatchset is zero, or the patchset

  198075. ** format otherwise.

  198076. */

  198077. static int sessionAppendDelete(

  198078.   SessionBuffer *pBuf,            /* Buffer to append to */

  198079.   int bPatchset,                  /* True for "patchset", 0 for "changeset" */

  198080.   SessionChange *p,               /* Object containing old values */

  198081.   int nCol,                       /* Number of columns in table */

  198082.   u8 *abPK                        /* Boolean array - true for PK columns */

  198083. ){

  198084.   int rc = SQLITE_OK;

  198085. 

  198086.   sessionAppendByte(pBuf, SQLITE_DELETE, &rc);

  198087.   sessionAppendByte(pBuf, p->bIndirect, &rc);

  198088. 

  198089.   if( bPatchset==0 ){

  198090.     sessionAppendBlob(pBuf, p->aRecord, p->nRecord, &rc);

  198091.   }else{

  198092.     int i;

  198093.     u8 *a = p->aRecord;

  198094.     for(i=0; i<nCol; i++){

  198095.       u8 *pStart = a;

  198096.       int eType = *a++;

  198097. 

  198098.       switch( eType ){

  198099.         case 0:

  198100.         case SQLITE_NULL:

  198101.           assert( abPK[i]==0 );

  198102.           break;

  198103. 

  198104.         case SQLITE_FLOAT:

  198105.         case SQLITE_INTEGER:

  198106.           a += 8;

  198107.           break;

  198108. 

  198109.         default: {

  198110.           int n;

  198111.           a += sessionVarintGet(a, &n);

  198112.           a += n;

  198113.           break;

  198114.         }

  198115.       }

  198116.       if( abPK[i] ){

  198117.         sessionAppendBlob(pBuf, pStart, (int)(a-pStart), &rc);

  198118.       }

  198119.     }

  198120.     assert( (a - p->aRecord)==p->nRecord );

  198121.   }

  198122. 

  198123.   return rc;

  198124. }

  198125. 

  198126. /*

  198127. ** Formulate and prepare a SELECT statement to retrieve a row from table

  198128. ** zTab in database zDb based on its primary key. i.e.

  198129. **

  198130. **   SELECT * FROM zDb.zTab WHERE pk1 = ? AND pk2 = ? AND ...

  198131. */

  198132. static int sessionSelectStmt(

  198133.   sqlite3 *db,                    /* Database handle */

  198134.   const char *zDb,                /* Database name */

  198135.   const char *zTab,               /* Table name */

  198136.   int nCol,                       /* Number of columns in table */

  198137.   const char **azCol,             /* Names of table columns */

  198138.   u8 *abPK,                       /* PRIMARY KEY  array */

  198139.   sqlite3_stmt **ppStmt           /* OUT: Prepared SELECT statement */

  198140. ){

  198141.   int rc = SQLITE_OK;

  198142.   char *zSql = 0;

  198143.   int nSql = -1;

  198144. 

  198145.   if( 0==sqlite3_stricmp("sqlite_stat1", zTab) ){

  198146.     zSql = sqlite3_mprintf(

  198147.         "SELECT tbl, ?2, stat FROM %Q.sqlite_stat1 WHERE tbl IS ?1 AND "

  198148.         "idx IS (CASE WHEN ?2=X'' THEN NULL ELSE ?2 END)", zDb

  198149.     );

  198150.     if( zSql==0 ) rc = SQLITE_NOMEM;

  198151.   }else{

  198152.     int i;

  198153.     const char *zSep = "";

  198154.     SessionBuffer buf = {0, 0, 0};

  198155. 

  198156.     sessionAppendStr(&buf, "SELECT * FROM ", &rc);

  198157.     sessionAppendIdent(&buf, zDb, &rc);

  198158.     sessionAppendStr(&buf, ".", &rc);

  198159.     sessionAppendIdent(&buf, zTab, &rc);

  198160.     sessionAppendStr(&buf, " WHERE ", &rc);

  198161.     for(i=0; i<nCol; i++){

  198162.       if( abPK[i] ){

  198163.         sessionAppendStr(&buf, zSep, &rc);

  198164.         sessionAppendIdent(&buf, azCol[i], &rc);

  198165.         sessionAppendStr(&buf, " IS ?", &rc);

  198166.         sessionAppendInteger(&buf, i+1, &rc);

  198167.         zSep = " AND ";

  198168.       }

  198169.     }

  198170.     zSql = (char*)buf.aBuf;

  198171.     nSql = buf.nBuf;

  198172.   }

  198173. 

  198174.   if( rc==SQLITE_OK ){

  198175.     rc = sqlite3_prepare_v2(db, zSql, nSql, ppStmt, 0);

  198176.   }

  198177.   sqlite3_free(zSql);

  198178.   return rc;

  198179. }

  198180. 

  198181. /*

  198182. ** Bind the PRIMARY KEY values from the change passed in argument pChange

  198183. ** to the SELECT statement passed as the first argument. The SELECT statement

  198184. ** is as prepared by function sessionSelectStmt().

  198185. **

  198186. ** Return SQLITE_OK if all PK values are successfully bound, or an SQLite

  198187. ** error code (e.g. SQLITE_NOMEM) otherwise.

  198188. */

  198189. static int sessionSelectBind(

  198190.   sqlite3_stmt *pSelect,          /* SELECT from sessionSelectStmt() */

  198191.   int nCol,                       /* Number of columns in table */

  198192.   u8 *abPK,                       /* PRIMARY KEY array */

  198193.   SessionChange *pChange          /* Change structure */

  198194. ){

  198195.   int i;

  198196.   int rc = SQLITE_OK;

  198197.   u8 *a = pChange->aRecord;

  198198. 

  198199.   for(i=0; i<nCol && rc==SQLITE_OK; i++){

  198200.     int eType = *a++;

  198201. 

  198202.     switch( eType ){

  198203.       case 0:

  198204.       case SQLITE_NULL:

  198205.         assert( abPK[i]==0 );

  198206.         break;

  198207. 

  198208.       case SQLITE_INTEGER: {

  198209.         if( abPK[i] ){

  198210.           i64 iVal = sessionGetI64(a);

  198211.           rc = sqlite3_bind_int64(pSelect, i+1, iVal);

  198212.         }

  198213.         a += 8;

  198214.         break;

  198215.       }

  198216. 

  198217.       case SQLITE_FLOAT: {

  198218.         if( abPK[i] ){

  198219.           double rVal;

  198220.           i64 iVal = sessionGetI64(a);

  198221.           memcpy(&rVal, &iVal, 8);

  198222.           rc = sqlite3_bind_double(pSelect, i+1, rVal);

  198223.         }

  198224.         a += 8;

  198225.         break;

  198226.       }

  198227. 

  198228.       case SQLITE_TEXT: {

  198229.         int n;

  198230.         a += sessionVarintGet(a, &n);

  198231.         if( abPK[i] ){

  198232.           rc = sqlite3_bind_text(pSelect, i+1, (char *)a, n, SQLITE_TRANSIENT);

  198233.         }

  198234.         a += n;

  198235.         break;

  198236.       }

  198237. 

  198238.       default: {

  198239.         int n;

  198240.         assert( eType==SQLITE_BLOB );

  198241.         a += sessionVarintGet(a, &n);

  198242.         if( abPK[i] ){

  198243.           rc = sqlite3_bind_blob(pSelect, i+1, a, n, SQLITE_TRANSIENT);

  198244.         }

  198245.         a += n;

  198246.         break;

  198247.       }

  198248.     }

  198249.   }

  198250. 

  198251.   return rc;

  198252. }

  198253. 

  198254. /*

  198255. ** This function is a no-op if *pRc is set to other than SQLITE_OK when it

  198256. ** is called. Otherwise, append a serialized table header (part of the binary 

  198257. ** changeset format) to buffer *pBuf. If an error occurs, set *pRc to an

  198258. ** SQLite error code before returning.

  198259. */

  198260. static void sessionAppendTableHdr(

  198261.   SessionBuffer *pBuf,            /* Append header to this buffer */

  198262.   int bPatchset,                  /* Use the patchset format if true */

  198263.   SessionTable *pTab,             /* Table object to append header for */

  198264.   int *pRc                        /* IN/OUT: Error code */

  198265. ){

  198266.   /* Write a table header */

  198267.   sessionAppendByte(pBuf, (bPatchset ? 'P' : 'T'), pRc);

  198268.   sessionAppendVarint(pBuf, pTab->nCol, pRc);

  198269.   sessionAppendBlob(pBuf, pTab->abPK, pTab->nCol, pRc);

  198270.   sessionAppendBlob(pBuf, (u8 *)pTab->zName, (int)strlen(pTab->zName)+1, pRc);

  198271. }

  198272. 

  198273. /*

  198274. ** Generate either a changeset (if argument bPatchset is zero) or a patchset

  198275. ** (if it is non-zero) based on the current contents of the session object

  198276. ** passed as the first argument.

  198277. **

  198278. ** If no error occurs, SQLITE_OK is returned and the new changeset/patchset

  198279. ** stored in output variables *pnChangeset and *ppChangeset. Or, if an error

  198280. ** occurs, an SQLite error code is returned and both output variables set 

  198281. ** to 0.

  198282. */

  198283. static int sessionGenerateChangeset(

  198284.   sqlite3_session *pSession,      /* Session object */

  198285.   int bPatchset,                  /* True for patchset, false for changeset */

  198286.   int (*xOutput)(void *pOut, const void *pData, int nData),

  198287.   void *pOut,                     /* First argument for xOutput */

  198288.   int *pnChangeset,               /* OUT: Size of buffer at *ppChangeset */

  198289.   void **ppChangeset              /* OUT: Buffer containing changeset */

  198290. ){

  198291.   sqlite3 *db = pSession->db;     /* Source database handle */

  198292.   SessionTable *pTab;             /* Used to iterate through attached tables */

  198293.   SessionBuffer buf = {0,0,0};    /* Buffer in which to accumlate changeset */

  198294.   int rc;                         /* Return code */

  198295. 

  198296.   assert( xOutput==0 || (pnChangeset==0 && ppChangeset==0 ) );

  198297. 

  198298.   /* Zero the output variables in case an error occurs. If this session

  198299.   ** object is already in the error state (sqlite3_session.rc != SQLITE_OK),

  198300.   ** this call will be a no-op.  */

  198301.   if( xOutput==0 ){

  198302.     *pnChangeset = 0;

  198303.     *ppChangeset = 0;

  198304.   }

  198305. 

  198306.   if( pSession->rc ) return pSession->rc;

  198307.   rc = sqlite3_exec(pSession->db, "SAVEPOINT changeset", 0, 0, 0);

  198308.   if( rc!=SQLITE_OK ) return rc;

  198309. 

  198310.   sqlite3_mutex_enter(sqlite3_db_mutex(db));

  198311. 

  198312.   for(pTab=pSession->pTable; rc==SQLITE_OK && pTab; pTab=pTab->pNext){

  198313.     if( pTab->nEntry ){

  198314.       const char *zName = pTab->zName;

  198315.       int nCol;                   /* Number of columns in table */

  198316.       u8 *abPK;                   /* Primary key array */

  198317.       const char **azCol = 0;     /* Table columns */

  198318.       int i;                      /* Used to iterate through hash buckets */

  198319.       sqlite3_stmt *pSel = 0;     /* SELECT statement to query table pTab */

  198320.       int nRewind = buf.nBuf;     /* Initial size of write buffer */

  198321.       int nNoop;                  /* Size of buffer after writing tbl header */

  198322. 

  198323.       /* Check the table schema is still Ok. */

  198324.       rc = sessionTableInfo(db, pSession->zDb, zName, &nCol, 0, &azCol, &abPK);

  198325.       if( !rc && (pTab->nCol!=nCol || memcmp(abPK, pTab->abPK, nCol)) ){

  198326.         rc = SQLITE_SCHEMA;

  198327.       }

  198328. 

  198329.       /* Write a table header */

  198330.       sessionAppendTableHdr(&buf, bPatchset, pTab, &rc);

  198331. 

  198332.       /* Build and compile a statement to execute: */

  198333.       if( rc==SQLITE_OK ){

  198334.         rc = sessionSelectStmt(

  198335.             db, pSession->zDb, zName, nCol, azCol, abPK, &pSel);

  198336.       }

  198337. 

  198338.       nNoop = buf.nBuf;

  198339.       for(i=0; i<pTab->nChange && rc==SQLITE_OK; i++){

  198340.         SessionChange *p;         /* Used to iterate through changes */

  198341. 

  198342.         for(p=pTab->apChange[i]; rc==SQLITE_OK && p; p=p->pNext){

  198343.           rc = sessionSelectBind(pSel, nCol, abPK, p);

  198344.           if( rc!=SQLITE_OK ) continue;

  198345.           if( sqlite3_step(pSel)==SQLITE_ROW ){

  198346.             if( p->op==SQLITE_INSERT ){

  198347.               int iCol;

  198348.               sessionAppendByte(&buf, SQLITE_INSERT, &rc);

  198349.               sessionAppendByte(&buf, p->bIndirect, &rc);

  198350.               for(iCol=0; iCol<nCol; iCol++){

  198351.                 sessionAppendCol(&buf, pSel, iCol, &rc);

  198352.               }

  198353.             }else{

  198354.               rc = sessionAppendUpdate(&buf, bPatchset, pSel, p, abPK);

  198355.             }

  198356.           }else if( p->op!=SQLITE_INSERT ){

  198357.             rc = sessionAppendDelete(&buf, bPatchset, p, nCol, abPK);

  198358.           }

  198359.           if( rc==SQLITE_OK ){

  198360.             rc = sqlite3_reset(pSel);

  198361.           }

  198362. 

  198363.           /* If the buffer is now larger than sessions_strm_chunk_size, pass

  198364.           ** its contents to the xOutput() callback. */

  198365.           if( xOutput 

  198366.            && rc==SQLITE_OK 

  198367.            && buf.nBuf>nNoop 

  198368.            && buf.nBuf>sessions_strm_chunk_size 

  198369.           ){

  198370.             rc = xOutput(pOut, (void*)buf.aBuf, buf.nBuf);

  198371.             nNoop = -1;

  198372.             buf.nBuf = 0;

  198373.           }

  198374. 

  198375.         }

  198376.       }

  198377. 

  198378.       sqlite3_finalize(pSel);

  198379.       if( buf.nBuf==nNoop ){

  198380.         buf.nBuf = nRewind;

  198381.       }

  198382.       sqlite3_free((char*)azCol);  /* cast works around VC++ bug */

  198383.     }

  198384.   }

  198385. 

  198386.   if( rc==SQLITE_OK ){

  198387.     if( xOutput==0 ){

  198388.       *pnChangeset = buf.nBuf;

  198389.       *ppChangeset = buf.aBuf;

  198390.       buf.aBuf = 0;

  198391.     }else if( buf.nBuf>0 ){

  198392.       rc = xOutput(pOut, (void*)buf.aBuf, buf.nBuf);

  198393.     }

  198394.   }

  198395. 

  198396.   sqlite3_free(buf.aBuf);

  198397.   sqlite3_exec(db, "RELEASE changeset", 0, 0, 0);

  198398.   sqlite3_mutex_leave(sqlite3_db_mutex(db));

  198399.   return rc;

  198400. }

  198401. 

  198402. /*

  198403. ** Obtain a changeset object containing all changes recorded by the 

  198404. ** session object passed as the first argument.

  198405. **

  198406. ** It is the responsibility of the caller to eventually free the buffer 

  198407. ** using sqlite3_free().

  198408. */

  198409. SQLITE_API int sqlite3session_changeset(

  198410.   sqlite3_session *pSession,      /* Session object */

  198411.   int *pnChangeset,               /* OUT: Size of buffer at *ppChangeset */

  198412.   void **ppChangeset              /* OUT: Buffer containing changeset */

  198413. ){

  198414.   return sessionGenerateChangeset(pSession, 0, 0, 0, pnChangeset, ppChangeset);

  198415. }

  198416. 

  198417. /*

  198418. ** Streaming version of sqlite3session_changeset().

  198419. */

  198420. SQLITE_API int sqlite3session_changeset_strm(

  198421.   sqlite3_session *pSession,

  198422.   int (*xOutput)(void *pOut, const void *pData, int nData),

  198423.   void *pOut

  198424. ){

  198425.   return sessionGenerateChangeset(pSession, 0, xOutput, pOut, 0, 0);

  198426. }

  198427. 

  198428. /*

  198429. ** Streaming version of sqlite3session_patchset().

  198430. */

  198431. SQLITE_API int sqlite3session_patchset_strm(

  198432.   sqlite3_session *pSession,

  198433.   int (*xOutput)(void *pOut, const void *pData, int nData),

  198434.   void *pOut

  198435. ){

  198436.   return sessionGenerateChangeset(pSession, 1, xOutput, pOut, 0, 0);

  198437. }

  198438. 

  198439. /*

  198440. ** Obtain a patchset object containing all changes recorded by the 

  198441. ** session object passed as the first argument.

  198442. **

  198443. ** It is the responsibility of the caller to eventually free the buffer 

  198444. ** using sqlite3_free().

  198445. */

  198446. SQLITE_API int sqlite3session_patchset(

  198447.   sqlite3_session *pSession,      /* Session object */

  198448.   int *pnPatchset,                /* OUT: Size of buffer at *ppChangeset */

  198449.   void **ppPatchset               /* OUT: Buffer containing changeset */

  198450. ){

  198451.   return sessionGenerateChangeset(pSession, 1, 0, 0, pnPatchset, ppPatchset);

  198452. }

  198453. 

  198454. /*

  198455. ** Enable or disable the session object passed as the first argument.

  198456. */

  198457. SQLITE_API int sqlite3session_enable(sqlite3_session *pSession, int bEnable){

  198458.   int ret;

  198459.   sqlite3_mutex_enter(sqlite3_db_mutex(pSession->db));

  198460.   if( bEnable>=0 ){

  198461.     pSession->bEnable = bEnable;

  198462.   }

  198463.   ret = pSession->bEnable;

  198464.   sqlite3_mutex_leave(sqlite3_db_mutex(pSession->db));

  198465.   return ret;

  198466. }

  198467. 

  198468. /*

  198469. ** Enable or disable the session object passed as the first argument.

  198470. */

  198471. SQLITE_API int sqlite3session_indirect(sqlite3_session *pSession, int bIndirect){

  198472.   int ret;

  198473.   sqlite3_mutex_enter(sqlite3_db_mutex(pSession->db));

  198474.   if( bIndirect>=0 ){

  198475.     pSession->bIndirect = bIndirect;

  198476.   }

  198477.   ret = pSession->bIndirect;

  198478.   sqlite3_mutex_leave(sqlite3_db_mutex(pSession->db));

  198479.   return ret;

  198480. }

  198481. 

  198482. /*

  198483. ** Return true if there have been no changes to monitored tables recorded

  198484. ** by the session object passed as the only argument.

  198485. */

  198486. SQLITE_API int sqlite3session_isempty(sqlite3_session *pSession){

  198487.   int ret = 0;

  198488.   SessionTable *pTab;

  198489. 

  198490.   sqlite3_mutex_enter(sqlite3_db_mutex(pSession->db));

  198491.   for(pTab=pSession->pTable; pTab && ret==0; pTab=pTab->pNext){

  198492.     ret = (pTab->nEntry>0);

  198493.   }

  198494.   sqlite3_mutex_leave(sqlite3_db_mutex(pSession->db));

  198495. 

  198496.   return (ret==0);

  198497. }

  198498. 

  198499. /*

  198500. ** Do the work for either sqlite3changeset_start() or start_strm().

  198501. */

  198502. static int sessionChangesetStart(

  198503.   sqlite3_changeset_iter **pp,    /* OUT: Changeset iterator handle */

  198504.   int (*xInput)(void *pIn, void *pData, int *pnData),

  198505.   void *pIn,

  198506.   int nChangeset,                 /* Size of buffer pChangeset in bytes */

  198507.   void *pChangeset,               /* Pointer to buffer containing changeset */

  198508.   int bInvert                     /* True to invert changeset */

  198509. ){

  198510.   sqlite3_changeset_iter *pRet;   /* Iterator to return */

  198511.   int nByte;                      /* Number of bytes to allocate for iterator */

  198512. 

  198513.   assert( xInput==0 || (pChangeset==0 && nChangeset==0) );

  198514. 

  198515.   /* Zero the output variable in case an error occurs. */

  198516.   *pp = 0;

  198517. 

  198518.   /* Allocate and initialize the iterator structure. */

  198519.   nByte = sizeof(sqlite3_changeset_iter);

  198520.   pRet = (sqlite3_changeset_iter *)sqlite3_malloc(nByte);

  198521.   if( !pRet ) return SQLITE_NOMEM;

  198522.   memset(pRet, 0, sizeof(sqlite3_changeset_iter));

  198523.   pRet->in.aData = (u8 *)pChangeset;

  198524.   pRet->in.nData = nChangeset;

  198525.   pRet->in.xInput = xInput;

  198526.   pRet->in.pIn = pIn;

  198527.   pRet->in.bEof = (xInput ? 0 : 1);

  198528.   pRet->bInvert = bInvert;

  198529. 

  198530.   /* Populate the output variable and return success. */

  198531.   *pp = pRet;

  198532.   return SQLITE_OK;

  198533. }

  198534. 

  198535. /*

  198536. ** Create an iterator used to iterate through the contents of a changeset.

  198537. */

  198538. SQLITE_API int sqlite3changeset_start(

  198539.   sqlite3_changeset_iter **pp,    /* OUT: Changeset iterator handle */

  198540.   int nChangeset,                 /* Size of buffer pChangeset in bytes */

  198541.   void *pChangeset                /* Pointer to buffer containing changeset */

  198542. ){

  198543.   return sessionChangesetStart(pp, 0, 0, nChangeset, pChangeset, 0);

  198544. }

  198545. SQLITE_API int sqlite3changeset_start_v2(

  198546.   sqlite3_changeset_iter **pp,    /* OUT: Changeset iterator handle */

  198547.   int nChangeset,                 /* Size of buffer pChangeset in bytes */

  198548.   void *pChangeset,               /* Pointer to buffer containing changeset */

  198549.   int flags

  198550. ){

  198551.   int bInvert = !!(flags & SQLITE_CHANGESETSTART_INVERT);

  198552.   return sessionChangesetStart(pp, 0, 0, nChangeset, pChangeset, bInvert);

  198553. }

  198554. 

  198555. /*

  198556. ** Streaming version of sqlite3changeset_start().

  198557. */

  198558. SQLITE_API int sqlite3changeset_start_strm(

  198559.   sqlite3_changeset_iter **pp,    /* OUT: Changeset iterator handle */

  198560.   int (*xInput)(void *pIn, void *pData, int *pnData),

  198561.   void *pIn

  198562. ){

  198563.   return sessionChangesetStart(pp, xInput, pIn, 0, 0, 0);

  198564. }

  198565. SQLITE_API int sqlite3changeset_start_v2_strm(

  198566.   sqlite3_changeset_iter **pp,    /* OUT: Changeset iterator handle */

  198567.   int (*xInput)(void *pIn, void *pData, int *pnData),

  198568.   void *pIn,

  198569.   int flags

  198570. ){

  198571.   int bInvert = !!(flags & SQLITE_CHANGESETSTART_INVERT);

  198572.   return sessionChangesetStart(pp, xInput, pIn, 0, 0, bInvert);

  198573. }

  198574. 

  198575. /*

  198576. ** If the SessionInput object passed as the only argument is a streaming

  198577. ** object and the buffer is full, discard some data to free up space.

  198578. */

  198579. static void sessionDiscardData(SessionInput *pIn){

  198580.   if( pIn->xInput && pIn->iNext>=sessions_strm_chunk_size ){

  198581.     int nMove = pIn->buf.nBuf - pIn->iNext;

  198582.     assert( nMove>=0 );

  198583.     if( nMove>0 ){

  198584.       memmove(pIn->buf.aBuf, &pIn->buf.aBuf[pIn->iNext], nMove);

  198585.     }

  198586.     pIn->buf.nBuf -= pIn->iNext;

  198587.     pIn->iNext = 0;

  198588.     pIn->nData = pIn->buf.nBuf;

  198589.   }

  198590. }

  198591. 

  198592. /*

  198593. ** Ensure that there are at least nByte bytes available in the buffer. Or,

  198594. ** if there are not nByte bytes remaining in the input, that all available

  198595. ** data is in the buffer.

  198596. **

  198597. ** Return an SQLite error code if an error occurs, or SQLITE_OK otherwise.

  198598. */

  198599. static int sessionInputBuffer(SessionInput *pIn, int nByte){

  198600.   int rc = SQLITE_OK;

  198601.   if( pIn->xInput ){

  198602.     while( !pIn->bEof && (pIn->iNext+nByte)>=pIn->nData && rc==SQLITE_OK ){

  198603.       int nNew = sessions_strm_chunk_size;

  198604. 

  198605.       if( pIn->bNoDiscard==0 ) sessionDiscardData(pIn);

  198606.       if( SQLITE_OK==sessionBufferGrow(&pIn->buf, nNew, &rc) ){

  198607.         rc = pIn->xInput(pIn->pIn, &pIn->buf.aBuf[pIn->buf.nBuf], &nNew);

  198608.         if( nNew==0 ){

  198609.           pIn->bEof = 1;

  198610.         }else{

  198611.           pIn->buf.nBuf += nNew;

  198612.         }

  198613.       }

  198614. 

  198615.       pIn->aData = pIn->buf.aBuf;

  198616.       pIn->nData = pIn->buf.nBuf;

  198617.     }

  198618.   }

  198619.   return rc;

  198620. }

  198621. 

  198622. /*

  198623. ** When this function is called, *ppRec points to the start of a record

  198624. ** that contains nCol values. This function advances the pointer *ppRec

  198625. ** until it points to the byte immediately following that record.

  198626. */

  198627. static void sessionSkipRecord(

  198628.   u8 **ppRec,                     /* IN/OUT: Record pointer */

  198629.   int nCol                        /* Number of values in record */

  198630. ){

  198631.   u8 *aRec = *ppRec;

  198632.   int i;

  198633.   for(i=0; i<nCol; i++){

  198634.     int eType = *aRec++;

  198635.     if( eType==SQLITE_TEXT || eType==SQLITE_BLOB ){

  198636.       int nByte;

  198637.       aRec += sessionVarintGet((u8*)aRec, &nByte);

  198638.       aRec += nByte;

  198639.     }else if( eType==SQLITE_INTEGER || eType==SQLITE_FLOAT ){

  198640.       aRec += 8;

  198641.     }

  198642.   }

  198643. 

  198644.   *ppRec = aRec;

  198645. }

  198646. 

  198647. /*

  198648. ** This function sets the value of the sqlite3_value object passed as the

  198649. ** first argument to a copy of the string or blob held in the aData[] 

  198650. ** buffer. SQLITE_OK is returned if successful, or SQLITE_NOMEM if an OOM

  198651. ** error occurs.

  198652. */

  198653. static int sessionValueSetStr(

  198654.   sqlite3_value *pVal,            /* Set the value of this object */

  198655.   u8 *aData,                      /* Buffer containing string or blob data */

  198656.   int nData,                      /* Size of buffer aData[] in bytes */

  198657.   u8 enc                          /* String encoding (0 for blobs) */

  198658. ){

  198659.   /* In theory this code could just pass SQLITE_TRANSIENT as the final

  198660.   ** argument to sqlite3ValueSetStr() and have the copy created 

  198661.   ** automatically. But doing so makes it difficult to detect any OOM

  198662.   ** error. Hence the code to create the copy externally. */

  198663.   u8 *aCopy = sqlite3_malloc64((sqlite3_int64)nData+1);

  198664.   if( aCopy==0 ) return SQLITE_NOMEM;

  198665.   memcpy(aCopy, aData, nData);

  198666.   sqlite3ValueSetStr(pVal, nData, (char*)aCopy, enc, sqlite3_free);

  198667.   return SQLITE_OK;

  198668. }

  198669. 

  198670. /*

  198671. ** Deserialize a single record from a buffer in memory. See "RECORD FORMAT"

  198672. ** for details.

  198673. **

  198674. ** When this function is called, *paChange points to the start of the record

  198675. ** to deserialize. Assuming no error occurs, *paChange is set to point to

  198676. ** one byte after the end of the same record before this function returns.

  198677. ** If the argument abPK is NULL, then the record contains nCol values. Or,

  198678. ** if abPK is other than NULL, then the record contains only the PK fields

  198679. ** (in other words, it is a patchset DELETE record).

  198680. **

  198681. ** If successful, each element of the apOut[] array (allocated by the caller)

  198682. ** is set to point to an sqlite3_value object containing the value read

  198683. ** from the corresponding position in the record. If that value is not

  198684. ** included in the record (i.e. because the record is part of an UPDATE change

  198685. ** and the field was not modified), the corresponding element of apOut[] is

  198686. ** set to NULL.

  198687. **

  198688. ** It is the responsibility of the caller to free all sqlite_value structures

  198689. ** using sqlite3_free().

  198690. **

  198691. ** If an error occurs, an SQLite error code (e.g. SQLITE_NOMEM) is returned.

  198692. ** The apOut[] array may have been partially populated in this case.

  198693. */

  198694. static int sessionReadRecord(

  198695.   SessionInput *pIn,              /* Input data */

  198696.   int nCol,                       /* Number of values in record */

  198697.   u8 *abPK,                       /* Array of primary key flags, or NULL */

  198698.   sqlite3_value **apOut           /* Write values to this array */

  198699. ){

  198700.   int i;                          /* Used to iterate through columns */

  198701.   int rc = SQLITE_OK;

  198702. 

  198703.   for(i=0; i<nCol && rc==SQLITE_OK; i++){

  198704.     int eType = 0;                /* Type of value (SQLITE_NULL, TEXT etc.) */

  198705.     if( abPK && abPK[i]==0 ) continue;

  198706.     rc = sessionInputBuffer(pIn, 9);

  198707.     if( rc==SQLITE_OK ){

  198708.       if( pIn->iNext>=pIn->nData ){

  198709.         rc = SQLITE_CORRUPT_BKPT;

  198710.       }else{

  198711.         eType = pIn->aData[pIn->iNext++];

  198712.         assert( apOut[i]==0 );

  198713.         if( eType ){

  198714.           apOut[i] = sqlite3ValueNew(0);

  198715.           if( !apOut[i] ) rc = SQLITE_NOMEM;

  198716.         }

  198717.       }

  198718.     }

  198719. 

  198720.     if( rc==SQLITE_OK ){

  198721.       u8 *aVal = &pIn->aData[pIn->iNext];

  198722.       if( eType==SQLITE_TEXT || eType==SQLITE_BLOB ){

  198723.         int nByte;

  198724.         pIn->iNext += sessionVarintGet(aVal, &nByte);

  198725.         rc = sessionInputBuffer(pIn, nByte);

  198726.         if( rc==SQLITE_OK ){

  198727.           if( nByte<0 || nByte>pIn->nData-pIn->iNext ){

  198728.             rc = SQLITE_CORRUPT_BKPT;

  198729.           }else{

  198730.             u8 enc = (eType==SQLITE_TEXT ? SQLITE_UTF8 : 0);

  198731.             rc = sessionValueSetStr(apOut[i],&pIn->aData[pIn->iNext],nByte,enc);

  198732.             pIn->iNext += nByte;

  198733.           }

  198734.         }

  198735.       }

  198736.       if( eType==SQLITE_INTEGER || eType==SQLITE_FLOAT ){

  198737.         sqlite3_int64 v = sessionGetI64(aVal);

  198738.         if( eType==SQLITE_INTEGER ){

  198739.           sqlite3VdbeMemSetInt64(apOut[i], v);

  198740.         }else{

  198741.           double d;

  198742.           memcpy(&d, &v, 8);

  198743.           sqlite3VdbeMemSetDouble(apOut[i], d);

  198744.         }

  198745.         pIn->iNext += 8;

  198746.       }

  198747.     }

  198748.   }

  198749. 

  198750.   return rc;

  198751. }

  198752. 

  198753. /*

  198754. ** The input pointer currently points to the second byte of a table-header.

  198755. ** Specifically, to the following:

  198756. **

  198757. **   + number of columns in table (varint)

  198758. **   + array of PK flags (1 byte per column),

  198759. **   + table name (nul terminated).

  198760. **

  198761. ** This function ensures that all of the above is present in the input 

  198762. ** buffer (i.e. that it can be accessed without any calls to xInput()).

  198763. ** If successful, SQLITE_OK is returned. Otherwise, an SQLite error code.

  198764. ** The input pointer is not moved.

  198765. */

  198766. static int sessionChangesetBufferTblhdr(SessionInput *pIn, int *pnByte){

  198767.   int rc = SQLITE_OK;

  198768.   int nCol = 0;

  198769.   int nRead = 0;

  198770. 

  198771.   rc = sessionInputBuffer(pIn, 9);

  198772.   if( rc==SQLITE_OK ){

  198773.     nRead += sessionVarintGet(&pIn->aData[pIn->iNext + nRead], &nCol);

  198774.     /* The hard upper limit for the number of columns in an SQLite

  198775.     ** database table is, according to sqliteLimit.h, 32676. So 

  198776.     ** consider any table-header that purports to have more than 65536 

  198777.     ** columns to be corrupt. This is convenient because otherwise, 

  198778.     ** if the (nCol>65536) condition below were omitted, a sufficiently 

  198779.     ** large value for nCol may cause nRead to wrap around and become 

  198780.     ** negative. Leading to a crash. */

  198781.     if( nCol<0 || nCol>65536 ){

  198782.       rc = SQLITE_CORRUPT_BKPT;

  198783.     }else{

  198784.       rc = sessionInputBuffer(pIn, nRead+nCol+100);

  198785.       nRead += nCol;

  198786.     }

  198787.   }

  198788. 

  198789.   while( rc==SQLITE_OK ){

  198790.     while( (pIn->iNext + nRead)<pIn->nData && pIn->aData[pIn->iNext + nRead] ){

  198791.       nRead++;

  198792.     }

  198793.     if( (pIn->iNext + nRead)<pIn->nData ) break;

  198794.     rc = sessionInputBuffer(pIn, nRead + 100);

  198795.   }

  198796.   *pnByte = nRead+1;

  198797.   return rc;

  198798. }

  198799. 

  198800. /*

  198801. ** The input pointer currently points to the first byte of the first field

  198802. ** of a record consisting of nCol columns. This function ensures the entire

  198803. ** record is buffered. It does not move the input pointer.

  198804. **

  198805. ** If successful, SQLITE_OK is returned and *pnByte is set to the size of

  198806. ** the record in bytes. Otherwise, an SQLite error code is returned. The

  198807. ** final value of *pnByte is undefined in this case.

  198808. */

  198809. static int sessionChangesetBufferRecord(

  198810.   SessionInput *pIn,              /* Input data */

  198811.   int nCol,                       /* Number of columns in record */

  198812.   int *pnByte                     /* OUT: Size of record in bytes */

  198813. ){

  198814.   int rc = SQLITE_OK;

  198815.   int nByte = 0;

  198816.   int i;

  198817.   for(i=0; rc==SQLITE_OK && i<nCol; i++){

  198818.     int eType;

  198819.     rc = sessionInputBuffer(pIn, nByte + 10);

  198820.     if( rc==SQLITE_OK ){

  198821.       eType = pIn->aData[pIn->iNext + nByte++];

  198822.       if( eType==SQLITE_TEXT || eType==SQLITE_BLOB ){

  198823.         int n;

  198824.         nByte += sessionVarintGet(&pIn->aData[pIn->iNext+nByte], &n);

  198825.         nByte += n;

  198826.         rc = sessionInputBuffer(pIn, nByte);

  198827.       }else if( eType==SQLITE_INTEGER || eType==SQLITE_FLOAT ){

  198828.         nByte += 8;

  198829.       }

  198830.     }

  198831.   }

  198832.   *pnByte = nByte;

  198833.   return rc;

  198834. }

  198835. 

  198836. /*

  198837. ** The input pointer currently points to the second byte of a table-header.

  198838. ** Specifically, to the following:

  198839. **

  198840. **   + number of columns in table (varint)

  198841. **   + array of PK flags (1 byte per column),

  198842. **   + table name (nul terminated).

  198843. **

  198844. ** This function decodes the table-header and populates the p->nCol, 

  198845. ** p->zTab and p->abPK[] variables accordingly. The p->apValue[] array is 

  198846. ** also allocated or resized according to the new value of p->nCol. The

  198847. ** input pointer is left pointing to the byte following the table header.

  198848. **

  198849. ** If successful, SQLITE_OK is returned. Otherwise, an SQLite error code

  198850. ** is returned and the final values of the various fields enumerated above

  198851. ** are undefined.

  198852. */

  198853. static int sessionChangesetReadTblhdr(sqlite3_changeset_iter *p){

  198854.   int rc;

  198855.   int nCopy;

  198856.   assert( p->rc==SQLITE_OK );

  198857. 

  198858.   rc = sessionChangesetBufferTblhdr(&p->in, &nCopy);

  198859.   if( rc==SQLITE_OK ){

  198860.     int nByte;

  198861.     int nVarint;

  198862.     nVarint = sessionVarintGet(&p->in.aData[p->in.iNext], &p->nCol);

  198863.     if( p->nCol>0 ){

  198864.       nCopy -= nVarint;

  198865.       p->in.iNext += nVarint;

  198866.       nByte = p->nCol * sizeof(sqlite3_value*) * 2 + nCopy;

  198867.       p->tblhdr.nBuf = 0;

  198868.       sessionBufferGrow(&p->tblhdr, nByte, &rc);

  198869.     }else{

  198870.       rc = SQLITE_CORRUPT_BKPT;

  198871.     }

  198872.   }

  198873. 

  198874.   if( rc==SQLITE_OK ){

  198875.     size_t iPK = sizeof(sqlite3_value*)*p->nCol*2;

  198876.     memset(p->tblhdr.aBuf, 0, iPK);

  198877.     memcpy(&p->tblhdr.aBuf[iPK], &p->in.aData[p->in.iNext], nCopy);

  198878.     p->in.iNext += nCopy;

  198879.   }

  198880. 

  198881.   p->apValue = (sqlite3_value**)p->tblhdr.aBuf;

  198882.   p->abPK = (u8*)&p->apValue[p->nCol*2];

  198883.   p->zTab = (char*)&p->abPK[p->nCol];

  198884.   return (p->rc = rc);

  198885. }

  198886. 

  198887. /*

  198888. ** Advance the changeset iterator to the next change.

  198889. **

  198890. ** If both paRec and pnRec are NULL, then this function works like the public

  198891. ** API sqlite3changeset_next(). If SQLITE_ROW is returned, then the

  198892. ** sqlite3changeset_new() and old() APIs may be used to query for values.

  198893. **

  198894. ** Otherwise, if paRec and pnRec are not NULL, then a pointer to the change

  198895. ** record is written to *paRec before returning and the number of bytes in

  198896. ** the record to *pnRec.

  198897. **

  198898. ** Either way, this function returns SQLITE_ROW if the iterator is 

  198899. ** successfully advanced to the next change in the changeset, an SQLite 

  198900. ** error code if an error occurs, or SQLITE_DONE if there are no further 

  198901. ** changes in the changeset.

  198902. */

  198903. static int sessionChangesetNext(

  198904.   sqlite3_changeset_iter *p,      /* Changeset iterator */

  198905.   u8 **paRec,                     /* If non-NULL, store record pointer here */

  198906.   int *pnRec,                     /* If non-NULL, store size of record here */

  198907.   int *pbNew                      /* If non-NULL, true if new table */

  198908. ){

  198909.   int i;

  198910.   u8 op;

  198911. 

  198912.   assert( (paRec==0 && pnRec==0) || (paRec && pnRec) );

  198913. 

  198914.   /* If the iterator is in the error-state, return immediately. */

  198915.   if( p->rc!=SQLITE_OK ) return p->rc;

  198916. 

  198917.   /* Free the current contents of p->apValue[], if any. */

  198918.   if( p->apValue ){

  198919.     for(i=0; i<p->nCol*2; i++){

  198920.       sqlite3ValueFree(p->apValue[i]);

  198921.     }

  198922.     memset(p->apValue, 0, sizeof(sqlite3_value*)*p->nCol*2);

  198923.   }

  198924. 

  198925.   /* Make sure the buffer contains at least 10 bytes of input data, or all

  198926.   ** remaining data if there are less than 10 bytes available. This is

  198927.   ** sufficient either for the 'T' or 'P' byte and the varint that follows

  198928.   ** it, or for the two single byte values otherwise. */

  198929.   p->rc = sessionInputBuffer(&p->in, 2);

  198930.   if( p->rc!=SQLITE_OK ) return p->rc;

  198931. 

  198932.   /* If the iterator is already at the end of the changeset, return DONE. */

  198933.   if( p->in.iNext>=p->in.nData ){

  198934.     return SQLITE_DONE;

  198935.   }

  198936. 

  198937.   sessionDiscardData(&p->in);

  198938.   p->in.iCurrent = p->in.iNext;

  198939. 

  198940.   op = p->in.aData[p->in.iNext++];

  198941.   while( op=='T' || op=='P' ){

  198942.     if( pbNew ) *pbNew = 1;

  198943.     p->bPatchset = (op=='P');

  198944.     if( sessionChangesetReadTblhdr(p) ) return p->rc;

  198945.     if( (p->rc = sessionInputBuffer(&p->in, 2)) ) return p->rc;

  198946.     p->in.iCurrent = p->in.iNext;

  198947.     if( p->in.iNext>=p->in.nData ) return SQLITE_DONE;

  198948.     op = p->in.aData[p->in.iNext++];

  198949.   }

  198950. 

  198951.   if( p->zTab==0 || (p->bPatchset && p->bInvert) ){

  198952.     /* The first record in the changeset is not a table header. Must be a

  198953.     ** corrupt changeset. */

  198954.     assert( p->in.iNext==1 || p->zTab );

  198955.     return (p->rc = SQLITE_CORRUPT_BKPT);

  198956.   }

  198957. 

  198958.   p->op = op;

  198959.   p->bIndirect = p->in.aData[p->in.iNext++];

  198960.   if( p->op!=SQLITE_UPDATE && p->op!=SQLITE_DELETE && p->op!=SQLITE_INSERT ){

  198961.     return (p->rc = SQLITE_CORRUPT_BKPT);

  198962.   }

  198963. 

  198964.   if( paRec ){ 

  198965.     int nVal;                     /* Number of values to buffer */

  198966.     if( p->bPatchset==0 && op==SQLITE_UPDATE ){

  198967.       nVal = p->nCol * 2;

  198968.     }else if( p->bPatchset && op==SQLITE_DELETE ){

  198969.       nVal = 0;

  198970.       for(i=0; i<p->nCol; i++) if( p->abPK[i] ) nVal++;

  198971.     }else{

  198972.       nVal = p->nCol;

  198973.     }

  198974.     p->rc = sessionChangesetBufferRecord(&p->in, nVal, pnRec);

  198975.     if( p->rc!=SQLITE_OK ) return p->rc;

  198976.     *paRec = &p->in.aData[p->in.iNext];

  198977.     p->in.iNext += *pnRec;

  198978.   }else{

  198979.     sqlite3_value **apOld = (p->bInvert ? &p->apValue[p->nCol] : p->apValue);

  198980.     sqlite3_value **apNew = (p->bInvert ? p->apValue : &p->apValue[p->nCol]);

  198981. 

  198982.     /* If this is an UPDATE or DELETE, read the old.* record. */

  198983.     if( p->op!=SQLITE_INSERT && (p->bPatchset==0 || p->op==SQLITE_DELETE) ){

  198984.       u8 *abPK = p->bPatchset ? p->abPK : 0;

  198985.       p->rc = sessionReadRecord(&p->in, p->nCol, abPK, apOld);

  198986.       if( p->rc!=SQLITE_OK ) return p->rc;

  198987.     }

  198988. 

  198989.     /* If this is an INSERT or UPDATE, read the new.* record. */

  198990.     if( p->op!=SQLITE_DELETE ){

  198991.       p->rc = sessionReadRecord(&p->in, p->nCol, 0, apNew);

  198992.       if( p->rc!=SQLITE_OK ) return p->rc;

  198993.     }

  198994. 

  198995.     if( (p->bPatchset || p->bInvert) && p->op==SQLITE_UPDATE ){

  198996.       /* If this is an UPDATE that is part of a patchset, then all PK and

  198997.       ** modified fields are present in the new.* record. The old.* record

  198998.       ** is currently completely empty. This block shifts the PK fields from

  198999.       ** new.* to old.*, to accommodate the code that reads these arrays.  */

  199000.       for(i=0; i<p->nCol; i++){

  199001.         assert( p->bPatchset==0 || p->apValue[i]==0 );

  199002.         if( p->abPK[i] ){

  199003.           assert( p->apValue[i]==0 );

  199004.           p->apValue[i] = p->apValue[i+p->nCol];

  199005.           if( p->apValue[i]==0 ) return (p->rc = SQLITE_CORRUPT_BKPT);

  199006.           p->apValue[i+p->nCol] = 0;

  199007.         }

  199008.       }

  199009.     }else if( p->bInvert ){

  199010.       if( p->op==SQLITE_INSERT ) p->op = SQLITE_DELETE;

  199011.       else if( p->op==SQLITE_DELETE ) p->op = SQLITE_INSERT;

  199012.     }

  199013.   }

  199014. 

  199015.   return SQLITE_ROW;

  199016. }

  199017. 

  199018. /*

  199019. ** Advance an iterator created by sqlite3changeset_start() to the next

  199020. ** change in the changeset. This function may return SQLITE_ROW, SQLITE_DONE

  199021. ** or SQLITE_CORRUPT.

  199022. **

  199023. ** This function may not be called on iterators passed to a conflict handler

  199024. ** callback by changeset_apply().

  199025. */

  199026. SQLITE_API int sqlite3changeset_next(sqlite3_changeset_iter *p){

  199027.   return sessionChangesetNext(p, 0, 0, 0);

  199028. }

  199029. 

  199030. /*

  199031. ** The following function extracts information on the current change

  199032. ** from a changeset iterator. It may only be called after changeset_next()

  199033. ** has returned SQLITE_ROW.

  199034. */

  199035. SQLITE_API int sqlite3changeset_op(

  199036.   sqlite3_changeset_iter *pIter,  /* Iterator handle */

  199037.   const char **pzTab,             /* OUT: Pointer to table name */

  199038.   int *pnCol,                     /* OUT: Number of columns in table */

  199039.   int *pOp,                       /* OUT: SQLITE_INSERT, DELETE or UPDATE */

  199040.   int *pbIndirect                 /* OUT: True if change is indirect */

  199041. ){

  199042.   *pOp = pIter->op;

  199043.   *pnCol = pIter->nCol;

  199044.   *pzTab = pIter->zTab;

  199045.   if( pbIndirect ) *pbIndirect = pIter->bIndirect;

  199046.   return SQLITE_OK;

  199047. }

  199048. 

  199049. /*

  199050. ** Return information regarding the PRIMARY KEY and number of columns in

  199051. ** the database table affected by the change that pIter currently points

  199052. ** to. This function may only be called after changeset_next() returns

  199053. ** SQLITE_ROW.

  199054. */

  199055. SQLITE_API int sqlite3changeset_pk(

  199056.   sqlite3_changeset_iter *pIter,  /* Iterator object */

  199057.   unsigned char **pabPK,          /* OUT: Array of boolean - true for PK cols */

  199058.   int *pnCol                      /* OUT: Number of entries in output array */

  199059. ){

  199060.   *pabPK = pIter->abPK;

  199061.   if( pnCol ) *pnCol = pIter->nCol;

  199062.   return SQLITE_OK;

  199063. }

  199064. 

  199065. /*

  199066. ** This function may only be called while the iterator is pointing to an

  199067. ** SQLITE_UPDATE or SQLITE_DELETE change (see sqlite3changeset_op()).

  199068. ** Otherwise, SQLITE_MISUSE is returned.

  199069. **

  199070. ** It sets *ppValue to point to an sqlite3_value structure containing the

  199071. ** iVal'th value in the old.* record. Or, if that particular value is not

  199072. ** included in the record (because the change is an UPDATE and the field

  199073. ** was not modified and is not a PK column), set *ppValue to NULL.

  199074. **

  199075. ** If value iVal is out-of-range, SQLITE_RANGE is returned and *ppValue is

  199076. ** not modified. Otherwise, SQLITE_OK.

  199077. */

  199078. SQLITE_API int sqlite3changeset_old(

  199079.   sqlite3_changeset_iter *pIter,  /* Changeset iterator */

  199080.   int iVal,                       /* Index of old.* value to retrieve */

  199081.   sqlite3_value **ppValue         /* OUT: Old value (or NULL pointer) */

  199082. ){

  199083.   if( pIter->op!=SQLITE_UPDATE && pIter->op!=SQLITE_DELETE ){

  199084.     return SQLITE_MISUSE;

  199085.   }

  199086.   if( iVal<0 || iVal>=pIter->nCol ){

  199087.     return SQLITE_RANGE;

  199088.   }

  199089.   *ppValue = pIter->apValue[iVal];

  199090.   return SQLITE_OK;

  199091. }

  199092. 

  199093. /*

  199094. ** This function may only be called while the iterator is pointing to an

  199095. ** SQLITE_UPDATE or SQLITE_INSERT change (see sqlite3changeset_op()).

  199096. ** Otherwise, SQLITE_MISUSE is returned.

  199097. **

  199098. ** It sets *ppValue to point to an sqlite3_value structure containing the

  199099. ** iVal'th value in the new.* record. Or, if that particular value is not

  199100. ** included in the record (because the change is an UPDATE and the field

  199101. ** was not modified), set *ppValue to NULL.

  199102. **

  199103. ** If value iVal is out-of-range, SQLITE_RANGE is returned and *ppValue is

  199104. ** not modified. Otherwise, SQLITE_OK.

  199105. */

  199106. SQLITE_API int sqlite3changeset_new(

  199107.   sqlite3_changeset_iter *pIter,  /* Changeset iterator */

  199108.   int iVal,                       /* Index of new.* value to retrieve */

  199109.   sqlite3_value **ppValue         /* OUT: New value (or NULL pointer) */

  199110. ){

  199111.   if( pIter->op!=SQLITE_UPDATE && pIter->op!=SQLITE_INSERT ){

  199112.     return SQLITE_MISUSE;

  199113.   }

  199114.   if( iVal<0 || iVal>=pIter->nCol ){

  199115.     return SQLITE_RANGE;

  199116.   }

  199117.   *ppValue = pIter->apValue[pIter->nCol+iVal];

  199118.   return SQLITE_OK;

  199119. }

  199120. 

  199121. /*

  199122. ** The following two macros are used internally. They are similar to the

  199123. ** sqlite3changeset_new() and sqlite3changeset_old() functions, except that

  199124. ** they omit all error checking and return a pointer to the requested value.

  199125. */

  199126. #define sessionChangesetNew(pIter, iVal) (pIter)->apValue[(pIter)->nCol+(iVal)]

  199127. #define sessionChangesetOld(pIter, iVal) (pIter)->apValue[(iVal)]

  199128. 

  199129. /*

  199130. ** This function may only be called with a changeset iterator that has been

  199131. ** passed to an SQLITE_CHANGESET_DATA or SQLITE_CHANGESET_CONFLICT 

  199132. ** conflict-handler function. Otherwise, SQLITE_MISUSE is returned.

  199133. **

  199134. ** If successful, *ppValue is set to point to an sqlite3_value structure

  199135. ** containing the iVal'th value of the conflicting record.

  199136. **

  199137. ** If value iVal is out-of-range or some other error occurs, an SQLite error

  199138. ** code is returned. Otherwise, SQLITE_OK.

  199139. */

  199140. SQLITE_API int sqlite3changeset_conflict(

  199141.   sqlite3_changeset_iter *pIter,  /* Changeset iterator */

  199142.   int iVal,                       /* Index of conflict record value to fetch */

  199143.   sqlite3_value **ppValue         /* OUT: Value from conflicting row */

  199144. ){

  199145.   if( !pIter->pConflict ){

  199146.     return SQLITE_MISUSE;

  199147.   }

  199148.   if( iVal<0 || iVal>=pIter->nCol ){

  199149.     return SQLITE_RANGE;

  199150.   }

  199151.   *ppValue = sqlite3_column_value(pIter->pConflict, iVal);

  199152.   return SQLITE_OK;

  199153. }

  199154. 

  199155. /*

  199156. ** This function may only be called with an iterator passed to an

  199157. ** SQLITE_CHANGESET_FOREIGN_KEY conflict handler callback. In this case

  199158. ** it sets the output variable to the total number of known foreign key

  199159. ** violations in the destination database and returns SQLITE_OK.

  199160. **

  199161. ** In all other cases this function returns SQLITE_MISUSE.

  199162. */

  199163. SQLITE_API int sqlite3changeset_fk_conflicts(

  199164.   sqlite3_changeset_iter *pIter,  /* Changeset iterator */

  199165.   int *pnOut                      /* OUT: Number of FK violations */

  199166. ){

  199167.   if( pIter->pConflict || pIter->apValue ){

  199168.     return SQLITE_MISUSE;

  199169.   }

  199170.   *pnOut = pIter->nCol;

  199171.   return SQLITE_OK;

  199172. }

  199173. 

  199174. 

  199175. /*

  199176. ** Finalize an iterator allocated with sqlite3changeset_start().

  199177. **

  199178. ** This function may not be called on iterators passed to a conflict handler

  199179. ** callback by changeset_apply().

  199180. */

  199181. SQLITE_API int sqlite3changeset_finalize(sqlite3_changeset_iter *p){

  199182.   int rc = SQLITE_OK;

  199183.   if( p ){

  199184.     int i;                        /* Used to iterate through p->apValue[] */

  199185.     rc = p->rc;

  199186.     if( p->apValue ){

  199187.       for(i=0; i<p->nCol*2; i++) sqlite3ValueFree(p->apValue[i]);

  199188.     }

  199189.     sqlite3_free(p->tblhdr.aBuf);

  199190.     sqlite3_free(p->in.buf.aBuf);

  199191.     sqlite3_free(p);

  199192.   }

  199193.   return rc;

  199194. }

  199195. 

  199196. static int sessionChangesetInvert(

  199197.   SessionInput *pInput,           /* Input changeset */

  199198.   int (*xOutput)(void *pOut, const void *pData, int nData),

  199199.   void *pOut,

  199200.   int *pnInverted,                /* OUT: Number of bytes in output changeset */

  199201.   void **ppInverted               /* OUT: Inverse of pChangeset */

  199202. ){

  199203.   int rc = SQLITE_OK;             /* Return value */

  199204.   SessionBuffer sOut;             /* Output buffer */

  199205.   int nCol = 0;                   /* Number of cols in current table */

  199206.   u8 *abPK = 0;                   /* PK array for current table */

  199207.   sqlite3_value **apVal = 0;      /* Space for values for UPDATE inversion */

  199208.   SessionBuffer sPK = {0, 0, 0};  /* PK array for current table */

  199209. 

  199210.   /* Initialize the output buffer */

  199211.   memset(&sOut, 0, sizeof(SessionBuffer));

  199212. 

  199213.   /* Zero the output variables in case an error occurs. */

  199214.   if( ppInverted ){

  199215.     *ppInverted = 0;

  199216.     *pnInverted = 0;

  199217.   }

  199218. 

  199219.   while( 1 ){

  199220.     u8 eType;

  199221. 

  199222.     /* Test for EOF. */

  199223.     if( (rc = sessionInputBuffer(pInput, 2)) ) goto finished_invert;

  199224.     if( pInput->iNext>=pInput->nData ) break;

  199225.     eType = pInput->aData[pInput->iNext];

  199226. 

  199227.     switch( eType ){

  199228.       case 'T': {

  199229.         /* A 'table' record consists of:

  199230.         **

  199231.         **   * A constant 'T' character,

  199232.         **   * Number of columns in said table (a varint),

  199233.         **   * An array of nCol bytes (sPK),

  199234.         **   * A nul-terminated table name.

  199235.         */

  199236.         int nByte;

  199237.         int nVar;

  199238.         pInput->iNext++;

  199239.         if( (rc = sessionChangesetBufferTblhdr(pInput, &nByte)) ){

  199240.           goto finished_invert;

  199241.         }

  199242.         nVar = sessionVarintGet(&pInput->aData[pInput->iNext], &nCol);

  199243.         sPK.nBuf = 0;

  199244.         sessionAppendBlob(&sPK, &pInput->aData[pInput->iNext+nVar], nCol, &rc);

  199245.         sessionAppendByte(&sOut, eType, &rc);

  199246.         sessionAppendBlob(&sOut, &pInput->aData[pInput->iNext], nByte, &rc);

  199247.         if( rc ) goto finished_invert;

  199248. 

  199249.         pInput->iNext += nByte;

  199250.         sqlite3_free(apVal);

  199251.         apVal = 0;

  199252.         abPK = sPK.aBuf;

  199253.         break;

  199254.       }

  199255. 

  199256.       case SQLITE_INSERT:

  199257.       case SQLITE_DELETE: {

  199258.         int nByte;

  199259.         int bIndirect = pInput->aData[pInput->iNext+1];

  199260.         int eType2 = (eType==SQLITE_DELETE ? SQLITE_INSERT : SQLITE_DELETE);

  199261.         pInput->iNext += 2;

  199262.         assert( rc==SQLITE_OK );

  199263.         rc = sessionChangesetBufferRecord(pInput, nCol, &nByte);

  199264.         sessionAppendByte(&sOut, eType2, &rc);

  199265.         sessionAppendByte(&sOut, bIndirect, &rc);

  199266.         sessionAppendBlob(&sOut, &pInput->aData[pInput->iNext], nByte, &rc);

  199267.         pInput->iNext += nByte;

  199268.         if( rc ) goto finished_invert;

  199269.         break;

  199270.       }

  199271. 

  199272.       case SQLITE_UPDATE: {

  199273.         int iCol;

  199274. 

  199275.         if( 0==apVal ){

  199276.           apVal = (sqlite3_value **)sqlite3_malloc64(sizeof(apVal[0])*nCol*2);

  199277.           if( 0==apVal ){

  199278.             rc = SQLITE_NOMEM;

  199279.             goto finished_invert;

  199280.           }

  199281.           memset(apVal, 0, sizeof(apVal[0])*nCol*2);

  199282.         }

  199283. 

  199284.         /* Write the header for the new UPDATE change. Same as the original. */

  199285.         sessionAppendByte(&sOut, eType, &rc);

  199286.         sessionAppendByte(&sOut, pInput->aData[pInput->iNext+1], &rc);

  199287. 

  199288.         /* Read the old.* and new.* records for the update change. */

  199289.         pInput->iNext += 2;

  199290.         rc = sessionReadRecord(pInput, nCol, 0, &apVal[0]);

  199291.         if( rc==SQLITE_OK ){

  199292.           rc = sessionReadRecord(pInput, nCol, 0, &apVal[nCol]);

  199293.         }

  199294. 

  199295.         /* Write the new old.* record. Consists of the PK columns from the

  199296.         ** original old.* record, and the other values from the original

  199297.         ** new.* record. */

  199298.         for(iCol=0; iCol<nCol; iCol++){

  199299.           sqlite3_value *pVal = apVal[iCol + (abPK[iCol] ? 0 : nCol)];

  199300.           sessionAppendValue(&sOut, pVal, &rc);

  199301.         }

  199302. 

  199303.         /* Write the new new.* record. Consists of a copy of all values

  199304.         ** from the original old.* record, except for the PK columns, which

  199305.         ** are set to "undefined". */

  199306.         for(iCol=0; iCol<nCol; iCol++){

  199307.           sqlite3_value *pVal = (abPK[iCol] ? 0 : apVal[iCol]);

  199308.           sessionAppendValue(&sOut, pVal, &rc);

  199309.         }

  199310. 

  199311.         for(iCol=0; iCol<nCol*2; iCol++){

  199312.           sqlite3ValueFree(apVal[iCol]);

  199313.         }

  199314.         memset(apVal, 0, sizeof(apVal[0])*nCol*2);

  199315.         if( rc!=SQLITE_OK ){

  199316.           goto finished_invert;

  199317.         }

  199318. 

  199319.         break;

  199320.       }

  199321. 

  199322.       default:

  199323.         rc = SQLITE_CORRUPT_BKPT;

  199324.         goto finished_invert;

  199325.     }

  199326. 

  199327.     assert( rc==SQLITE_OK );

  199328.     if( xOutput && sOut.nBuf>=sessions_strm_chunk_size ){

  199329.       rc = xOutput(pOut, sOut.aBuf, sOut.nBuf);

  199330.       sOut.nBuf = 0;

  199331.       if( rc!=SQLITE_OK ) goto finished_invert;

  199332.     }

  199333.   }

  199334. 

  199335.   assert( rc==SQLITE_OK );

  199336.   if( pnInverted ){

  199337.     *pnInverted = sOut.nBuf;

  199338.     *ppInverted = sOut.aBuf;

  199339.     sOut.aBuf = 0;

  199340.   }else if( sOut.nBuf>0 ){

  199341.     rc = xOutput(pOut, sOut.aBuf, sOut.nBuf);

  199342.   }

  199343. 

  199344.  finished_invert:

  199345.   sqlite3_free(sOut.aBuf);

  199346.   sqlite3_free(apVal);

  199347.   sqlite3_free(sPK.aBuf);

  199348.   return rc;

  199349. }

  199350. 

  199351. 

  199352. /*

  199353. ** Invert a changeset object.

  199354. */

  199355. SQLITE_API int sqlite3changeset_invert(

  199356.   int nChangeset,                 /* Number of bytes in input */

  199357.   const void *pChangeset,         /* Input changeset */

  199358.   int *pnInverted,                /* OUT: Number of bytes in output changeset */

  199359.   void **ppInverted               /* OUT: Inverse of pChangeset */

  199360. ){

  199361.   SessionInput sInput;

  199362. 

  199363.   /* Set up the input stream */

  199364.   memset(&sInput, 0, sizeof(SessionInput));

  199365.   sInput.nData = nChangeset;

  199366.   sInput.aData = (u8*)pChangeset;

  199367. 

  199368.   return sessionChangesetInvert(&sInput, 0, 0, pnInverted, ppInverted);

  199369. }

  199370. 

  199371. /*

  199372. ** Streaming version of sqlite3changeset_invert().

  199373. */

  199374. SQLITE_API int sqlite3changeset_invert_strm(

  199375.   int (*xInput)(void *pIn, void *pData, int *pnData),

  199376.   void *pIn,

  199377.   int (*xOutput)(void *pOut, const void *pData, int nData),

  199378.   void *pOut

  199379. ){

  199380.   SessionInput sInput;

  199381.   int rc;

  199382. 

  199383.   /* Set up the input stream */

  199384.   memset(&sInput, 0, sizeof(SessionInput));

  199385.   sInput.xInput = xInput;

  199386.   sInput.pIn = pIn;

  199387. 

  199388.   rc = sessionChangesetInvert(&sInput, xOutput, pOut, 0, 0);

  199389.   sqlite3_free(sInput.buf.aBuf);

  199390.   return rc;

  199391. }

  199392. 

  199393. typedef struct SessionApplyCtx SessionApplyCtx;

  199394. struct SessionApplyCtx {

  199395.   sqlite3 *db;

  199396.   sqlite3_stmt *pDelete;          /* DELETE statement */

  199397.   sqlite3_stmt *pUpdate;          /* UPDATE statement */

  199398.   sqlite3_stmt *pInsert;          /* INSERT statement */

  199399.   sqlite3_stmt *pSelect;          /* SELECT statement */

  199400.   int nCol;                       /* Size of azCol[] and abPK[] arrays */

  199401.   const char **azCol;             /* Array of column names */

  199402.   u8 *abPK;                       /* Boolean array - true if column is in PK */

  199403.   int bStat1;                     /* True if table is sqlite_stat1 */

  199404.   int bDeferConstraints;          /* True to defer constraints */

  199405.   SessionBuffer constraints;      /* Deferred constraints are stored here */

  199406.   SessionBuffer rebase;           /* Rebase information (if any) here */

  199407.   u8 bRebaseStarted;              /* If table header is already in rebase */

  199408.   u8 bRebase;                     /* True to collect rebase information */

  199409. };

  199410. 

  199411. /*

  199412. ** Formulate a statement to DELETE a row from database db. Assuming a table

  199413. ** structure like this:

  199414. **

  199415. **     CREATE TABLE x(a, b, c, d, PRIMARY KEY(a, c));

  199416. **

  199417. ** The DELETE statement looks like this:

  199418. **

  199419. **     DELETE FROM x WHERE a = :1 AND c = :3 AND (:5 OR b IS :2 AND d IS :4)

  199420. **

  199421. ** Variable :5 (nCol+1) is a boolean. It should be set to 0 if we require

  199422. ** matching b and d values, or 1 otherwise. The second case comes up if the

  199423. ** conflict handler is invoked with NOTFOUND and returns CHANGESET_REPLACE.

  199424. **

  199425. ** If successful, SQLITE_OK is returned and SessionApplyCtx.pDelete is left

  199426. ** pointing to the prepared version of the SQL statement.

  199427. */

  199428. static int sessionDeleteRow(

  199429.   sqlite3 *db,                    /* Database handle */

  199430.   const char *zTab,               /* Table name */

  199431.   SessionApplyCtx *p              /* Session changeset-apply context */

  199432. ){

  199433.   int i;

  199434.   const char *zSep = "";

  199435.   int rc = SQLITE_OK;

  199436.   SessionBuffer buf = {0, 0, 0};

  199437.   int nPk = 0;

  199438. 

  199439.   sessionAppendStr(&buf, "DELETE FROM ", &rc);

  199440.   sessionAppendIdent(&buf, zTab, &rc);

  199441.   sessionAppendStr(&buf, " WHERE ", &rc);

  199442. 

  199443.   for(i=0; i<p->nCol; i++){

  199444.     if( p->abPK[i] ){

  199445.       nPk++;

  199446.       sessionAppendStr(&buf, zSep, &rc);

  199447.       sessionAppendIdent(&buf, p->azCol[i], &rc);

  199448.       sessionAppendStr(&buf, " = ?", &rc);

  199449.       sessionAppendInteger(&buf, i+1, &rc);

  199450.       zSep = " AND ";

  199451.     }

  199452.   }

  199453. 

  199454.   if( nPk<p->nCol ){

  199455.     sessionAppendStr(&buf, " AND (?", &rc);

  199456.     sessionAppendInteger(&buf, p->nCol+1, &rc);

  199457.     sessionAppendStr(&buf, " OR ", &rc);

  199458. 

  199459.     zSep = "";

  199460.     for(i=0; i<p->nCol; i++){

  199461.       if( !p->abPK[i] ){

  199462.         sessionAppendStr(&buf, zSep, &rc);

  199463.         sessionAppendIdent(&buf, p->azCol[i], &rc);

  199464.         sessionAppendStr(&buf, " IS ?", &rc);

  199465.         sessionAppendInteger(&buf, i+1, &rc);

  199466.         zSep = "AND ";

  199467.       }

  199468.     }

  199469.     sessionAppendStr(&buf, ")", &rc);

  199470.   }

  199471. 

  199472.   if( rc==SQLITE_OK ){

  199473.     rc = sqlite3_prepare_v2(db, (char *)buf.aBuf, buf.nBuf, &p->pDelete, 0);

  199474.   }

  199475.   sqlite3_free(buf.aBuf);

  199476. 

  199477.   return rc;

  199478. }

  199479. 

  199480. /*

  199481. ** Formulate and prepare a statement to UPDATE a row from database db. 

  199482. ** Assuming a table structure like this:

  199483. **

  199484. **     CREATE TABLE x(a, b, c, d, PRIMARY KEY(a, c));

  199485. **

  199486. ** The UPDATE statement looks like this:

  199487. **

  199488. **     UPDATE x SET

  199489. **     a = CASE WHEN ?2  THEN ?3  ELSE a END,

  199490. **     b = CASE WHEN ?5  THEN ?6  ELSE b END,

  199491. **     c = CASE WHEN ?8  THEN ?9  ELSE c END,

  199492. **     d = CASE WHEN ?11 THEN ?12 ELSE d END

  199493. **     WHERE a = ?1 AND c = ?7 AND (?13 OR 

  199494. **       (?5==0 OR b IS ?4) AND (?11==0 OR d IS ?10) AND

  199495. **     )

  199496. **

  199497. ** For each column in the table, there are three variables to bind:

  199498. **

  199499. **     ?(i*3+1)    The old.* value of the column, if any.

  199500. **     ?(i*3+2)    A boolean flag indicating that the value is being modified.

  199501. **     ?(i*3+3)    The new.* value of the column, if any.

  199502. **

  199503. ** Also, a boolean flag that, if set to true, causes the statement to update

  199504. ** a row even if the non-PK values do not match. This is required if the

  199505. ** conflict-handler is invoked with CHANGESET_DATA and returns

  199506. ** CHANGESET_REPLACE. This is variable "?(nCol*3+1)".

  199507. **

  199508. ** If successful, SQLITE_OK is returned and SessionApplyCtx.pUpdate is left

  199509. ** pointing to the prepared version of the SQL statement.

  199510. */

  199511. static int sessionUpdateRow(

  199512.   sqlite3 *db,                    /* Database handle */

  199513.   const char *zTab,               /* Table name */

  199514.   SessionApplyCtx *p              /* Session changeset-apply context */

  199515. ){

  199516.   int rc = SQLITE_OK;

  199517.   int i;

  199518.   const char *zSep = "";

  199519.   SessionBuffer buf = {0, 0, 0};

  199520. 

  199521.   /* Append "UPDATE tbl SET " */

  199522.   sessionAppendStr(&buf, "UPDATE ", &rc);

  199523.   sessionAppendIdent(&buf, zTab, &rc);

  199524.   sessionAppendStr(&buf, " SET ", &rc);

  199525. 

  199526.   /* Append the assignments */

  199527.   for(i=0; i<p->nCol; i++){

  199528.     sessionAppendStr(&buf, zSep, &rc);

  199529.     sessionAppendIdent(&buf, p->azCol[i], &rc);

  199530.     sessionAppendStr(&buf, " = CASE WHEN ?", &rc);

  199531.     sessionAppendInteger(&buf, i*3+2, &rc);

  199532.     sessionAppendStr(&buf, " THEN ?", &rc);

  199533.     sessionAppendInteger(&buf, i*3+3, &rc);

  199534.     sessionAppendStr(&buf, " ELSE ", &rc);

  199535.     sessionAppendIdent(&buf, p->azCol[i], &rc);

  199536.     sessionAppendStr(&buf, " END", &rc);

  199537.     zSep = ", ";

  199538.   }

  199539. 

  199540.   /* Append the PK part of the WHERE clause */

  199541.   sessionAppendStr(&buf, " WHERE ", &rc);

  199542.   for(i=0; i<p->nCol; i++){

  199543.     if( p->abPK[i] ){

  199544.       sessionAppendIdent(&buf, p->azCol[i], &rc);

  199545.       sessionAppendStr(&buf, " = ?", &rc);

  199546.       sessionAppendInteger(&buf, i*3+1, &rc);

  199547.       sessionAppendStr(&buf, " AND ", &rc);

  199548.     }

  199549.   }

  199550. 

  199551.   /* Append the non-PK part of the WHERE clause */

  199552.   sessionAppendStr(&buf, " (?", &rc);

  199553.   sessionAppendInteger(&buf, p->nCol*3+1, &rc);

  199554.   sessionAppendStr(&buf, " OR 1", &rc);

  199555.   for(i=0; i<p->nCol; i++){

  199556.     if( !p->abPK[i] ){

  199557.       sessionAppendStr(&buf, " AND (?", &rc);

  199558.       sessionAppendInteger(&buf, i*3+2, &rc);

  199559.       sessionAppendStr(&buf, "=0 OR ", &rc);

  199560.       sessionAppendIdent(&buf, p->azCol[i], &rc);

  199561.       sessionAppendStr(&buf, " IS ?", &rc);

  199562.       sessionAppendInteger(&buf, i*3+1, &rc);

  199563.       sessionAppendStr(&buf, ")", &rc);

  199564.     }

  199565.   }

  199566.   sessionAppendStr(&buf, ")", &rc);

  199567. 

  199568.   if( rc==SQLITE_OK ){

  199569.     rc = sqlite3_prepare_v2(db, (char *)buf.aBuf, buf.nBuf, &p->pUpdate, 0);

  199570.   }

  199571.   sqlite3_free(buf.aBuf);

  199572. 

  199573.   return rc;

  199574. }

  199575. 

  199576. 

  199577. /*

  199578. ** Formulate and prepare an SQL statement to query table zTab by primary

  199579. ** key. Assuming the following table structure:

  199580. **

  199581. **     CREATE TABLE x(a, b, c, d, PRIMARY KEY(a, c));

  199582. **

  199583. ** The SELECT statement looks like this:

  199584. **

  199585. **     SELECT * FROM x WHERE a = ?1 AND c = ?3

  199586. **

  199587. ** If successful, SQLITE_OK is returned and SessionApplyCtx.pSelect is left

  199588. ** pointing to the prepared version of the SQL statement.

  199589. */

  199590. static int sessionSelectRow(

  199591.   sqlite3 *db,                    /* Database handle */

  199592.   const char *zTab,               /* Table name */

  199593.   SessionApplyCtx *p              /* Session changeset-apply context */

  199594. ){

  199595.   return sessionSelectStmt(

  199596.       db, "main", zTab, p->nCol, p->azCol, p->abPK, &p->pSelect);

  199597. }

  199598. 

  199599. /*

  199600. ** Formulate and prepare an INSERT statement to add a record to table zTab.

  199601. ** For example:

  199602. **

  199603. **     INSERT INTO main."zTab" VALUES(?1, ?2, ?3 ...);

  199604. **

  199605. ** If successful, SQLITE_OK is returned and SessionApplyCtx.pInsert is left

  199606. ** pointing to the prepared version of the SQL statement.

  199607. */

  199608. static int sessionInsertRow(

  199609.   sqlite3 *db,                    /* Database handle */

  199610.   const char *zTab,               /* Table name */

  199611.   SessionApplyCtx *p              /* Session changeset-apply context */

  199612. ){

  199613.   int rc = SQLITE_OK;

  199614.   int i;

  199615.   SessionBuffer buf = {0, 0, 0};

  199616. 

  199617.   sessionAppendStr(&buf, "INSERT INTO main.", &rc);

  199618.   sessionAppendIdent(&buf, zTab, &rc);

  199619.   sessionAppendStr(&buf, "(", &rc);

  199620.   for(i=0; i<p->nCol; i++){

  199621.     if( i!=0 ) sessionAppendStr(&buf, ", ", &rc);

  199622.     sessionAppendIdent(&buf, p->azCol[i], &rc);

  199623.   }

  199624. 

  199625.   sessionAppendStr(&buf, ") VALUES(?", &rc);

  199626.   for(i=1; i<p->nCol; i++){

  199627.     sessionAppendStr(&buf, ", ?", &rc);

  199628.   }

  199629.   sessionAppendStr(&buf, ")", &rc);

  199630. 

  199631.   if( rc==SQLITE_OK ){

  199632.     rc = sqlite3_prepare_v2(db, (char *)buf.aBuf, buf.nBuf, &p->pInsert, 0);

  199633.   }

  199634.   sqlite3_free(buf.aBuf);

  199635.   return rc;

  199636. }

  199637. 

  199638. static int sessionPrepare(sqlite3 *db, sqlite3_stmt **pp, const char *zSql){

  199639.   return sqlite3_prepare_v2(db, zSql, -1, pp, 0);

  199640. }

  199641. 

  199642. /*

  199643. ** Prepare statements for applying changes to the sqlite_stat1 table.

  199644. ** These are similar to those created by sessionSelectRow(),

  199645. ** sessionInsertRow(), sessionUpdateRow() and sessionDeleteRow() for 

  199646. ** other tables.

  199647. */

  199648. static int sessionStat1Sql(sqlite3 *db, SessionApplyCtx *p){

  199649.   int rc = sessionSelectRow(db, "sqlite_stat1", p);

  199650.   if( rc==SQLITE_OK ){

  199651.     rc = sessionPrepare(db, &p->pInsert,

  199652.         "INSERT INTO main.sqlite_stat1 VALUES(?1, "

  199653.         "CASE WHEN length(?2)=0 AND typeof(?2)='blob' THEN NULL ELSE ?2 END, "

  199654.         "?3)"

  199655.     );

  199656.   }

  199657.   if( rc==SQLITE_OK ){

  199658.     rc = sessionPrepare(db, &p->pUpdate,

  199659.         "UPDATE main.sqlite_stat1 SET "

  199660.         "tbl = CASE WHEN ?2 THEN ?3 ELSE tbl END, "

  199661.         "idx = CASE WHEN ?5 THEN ?6 ELSE idx END, "

  199662.         "stat = CASE WHEN ?8 THEN ?9 ELSE stat END  "

  199663.         "WHERE tbl=?1 AND idx IS "

  199664.         "CASE WHEN length(?4)=0 AND typeof(?4)='blob' THEN NULL ELSE ?4 END "

  199665.         "AND (?10 OR ?8=0 OR stat IS ?7)"

  199666.     );

  199667.   }

  199668.   if( rc==SQLITE_OK ){

  199669.     rc = sessionPrepare(db, &p->pDelete,

  199670.         "DELETE FROM main.sqlite_stat1 WHERE tbl=?1 AND idx IS "

  199671.         "CASE WHEN length(?2)=0 AND typeof(?2)='blob' THEN NULL ELSE ?2 END "

  199672.         "AND (?4 OR stat IS ?3)"

  199673.     );

  199674.   }

  199675.   return rc;

  199676. }

  199677. 

  199678. /*

  199679. ** A wrapper around sqlite3_bind_value() that detects an extra problem. 

  199680. ** See comments in the body of this function for details.

  199681. */

  199682. static int sessionBindValue(

  199683.   sqlite3_stmt *pStmt,            /* Statement to bind value to */

  199684.   int i,                          /* Parameter number to bind to */

  199685.   sqlite3_value *pVal             /* Value to bind */

  199686. ){

  199687.   int eType = sqlite3_value_type(pVal);

  199688.   /* COVERAGE: The (pVal->z==0) branch is never true using current versions

  199689.   ** of SQLite. If a malloc fails in an sqlite3_value_xxx() function, either

  199690.   ** the (pVal->z) variable remains as it was or the type of the value is

  199691.   ** set to SQLITE_NULL.  */

  199692.   if( (eType==SQLITE_TEXT || eType==SQLITE_BLOB) && pVal->z==0 ){

  199693.     /* This condition occurs when an earlier OOM in a call to

  199694.     ** sqlite3_value_text() or sqlite3_value_blob() (perhaps from within

  199695.     ** a conflict-handler) has zeroed the pVal->z pointer. Return NOMEM. */

  199696.     return SQLITE_NOMEM;

  199697.   }

  199698.   return sqlite3_bind_value(pStmt, i, pVal);

  199699. }

  199700. 

  199701. /*

  199702. ** Iterator pIter must point to an SQLITE_INSERT entry. This function 

  199703. ** transfers new.* values from the current iterator entry to statement

  199704. ** pStmt. The table being inserted into has nCol columns.

  199705. **

  199706. ** New.* value $i from the iterator is bound to variable ($i+1) of 

  199707. ** statement pStmt. If parameter abPK is NULL, all values from 0 to (nCol-1)

  199708. ** are transfered to the statement. Otherwise, if abPK is not NULL, it points

  199709. ** to an array nCol elements in size. In this case only those values for 

  199710. ** which abPK[$i] is true are read from the iterator and bound to the 

  199711. ** statement.

  199712. **

  199713. ** An SQLite error code is returned if an error occurs. Otherwise, SQLITE_OK.

  199714. */

  199715. static int sessionBindRow(

  199716.   sqlite3_changeset_iter *pIter,  /* Iterator to read values from */

  199717.   int(*xValue)(sqlite3_changeset_iter *, int, sqlite3_value **),

  199718.   int nCol,                       /* Number of columns */

  199719.   u8 *abPK,                       /* If not NULL, bind only if true */

  199720.   sqlite3_stmt *pStmt             /* Bind values to this statement */

  199721. ){

  199722.   int i;

  199723.   int rc = SQLITE_OK;

  199724. 

  199725.   /* Neither sqlite3changeset_old or sqlite3changeset_new can fail if the

  199726.   ** argument iterator points to a suitable entry. Make sure that xValue 

  199727.   ** is one of these to guarantee that it is safe to ignore the return 

  199728.   ** in the code below. */

  199729.   assert( xValue==sqlite3changeset_old || xValue==sqlite3changeset_new );

  199730. 

  199731.   for(i=0; rc==SQLITE_OK && i<nCol; i++){

  199732.     if( !abPK || abPK[i] ){

  199733.       sqlite3_value *pVal;

  199734.       (void)xValue(pIter, i, &pVal);

  199735.       if( pVal==0 ){

  199736.         /* The value in the changeset was "undefined". This indicates a

  199737.         ** corrupt changeset blob.  */

  199738.         rc = SQLITE_CORRUPT_BKPT;

  199739.       }else{

  199740.         rc = sessionBindValue(pStmt, i+1, pVal);

  199741.       }

  199742.     }

  199743.   }

  199744.   return rc;

  199745. }

  199746. 

  199747. /*

  199748. ** SQL statement pSelect is as generated by the sessionSelectRow() function.

  199749. ** This function binds the primary key values from the change that changeset

  199750. ** iterator pIter points to to the SELECT and attempts to seek to the table

  199751. ** entry. If a row is found, the SELECT statement left pointing at the row 

  199752. ** and SQLITE_ROW is returned. Otherwise, if no row is found and no error

  199753. ** has occured, the statement is reset and SQLITE_OK is returned. If an

  199754. ** error occurs, the statement is reset and an SQLite error code is returned.

  199755. **

  199756. ** If this function returns SQLITE_ROW, the caller must eventually reset() 

  199757. ** statement pSelect. If any other value is returned, the statement does

  199758. ** not require a reset().

  199759. **

  199760. ** If the iterator currently points to an INSERT record, bind values from the

  199761. ** new.* record to the SELECT statement. Or, if it points to a DELETE or

  199762. ** UPDATE, bind values from the old.* record. 

  199763. */

  199764. static int sessionSeekToRow(

  199765.   sqlite3 *db,                    /* Database handle */

  199766.   sqlite3_changeset_iter *pIter,  /* Changeset iterator */

  199767.   u8 *abPK,                       /* Primary key flags array */

  199768.   sqlite3_stmt *pSelect           /* SELECT statement from sessionSelectRow() */

  199769. ){

  199770.   int rc;                         /* Return code */

  199771.   int nCol;                       /* Number of columns in table */

  199772.   int op;                         /* Changset operation (SQLITE_UPDATE etc.) */

  199773.   const char *zDummy;             /* Unused */

  199774. 

  199775.   sqlite3changeset_op(pIter, &zDummy, &nCol, &op, 0);

  199776.   rc = sessionBindRow(pIter, 

  199777.       op==SQLITE_INSERT ? sqlite3changeset_new : sqlite3changeset_old,

  199778.       nCol, abPK, pSelect

  199779.   );

  199780. 

  199781.   if( rc==SQLITE_OK ){

  199782.     rc = sqlite3_step(pSelect);

  199783.     if( rc!=SQLITE_ROW ) rc = sqlite3_reset(pSelect);

  199784.   }

  199785. 

  199786.   return rc;

  199787. }

  199788. 

  199789. /*

  199790. ** This function is called from within sqlite3changeset_apply_v2() when

  199791. ** a conflict is encountered and resolved using conflict resolution

  199792. ** mode eType (either SQLITE_CHANGESET_OMIT or SQLITE_CHANGESET_REPLACE)..

  199793. ** It adds a conflict resolution record to the buffer in 

  199794. ** SessionApplyCtx.rebase, which will eventually be returned to the caller

  199795. ** of apply_v2() as the "rebase" buffer.

  199796. **

  199797. ** Return SQLITE_OK if successful, or an SQLite error code otherwise.

  199798. */

  199799. static int sessionRebaseAdd(

  199800.   SessionApplyCtx *p,             /* Apply context */

  199801.   int eType,                      /* Conflict resolution (OMIT or REPLACE) */

  199802.   sqlite3_changeset_iter *pIter   /* Iterator pointing at current change */

  199803. ){

  199804.   int rc = SQLITE_OK;

  199805.   if( p->bRebase ){

  199806.     int i;

  199807.     int eOp = pIter->op;

  199808.     if( p->bRebaseStarted==0 ){

  199809.       /* Append a table-header to the rebase buffer */

  199810.       const char *zTab = pIter->zTab;

  199811.       sessionAppendByte(&p->rebase, 'T', &rc);

  199812.       sessionAppendVarint(&p->rebase, p->nCol, &rc);

  199813.       sessionAppendBlob(&p->rebase, p->abPK, p->nCol, &rc);

  199814.       sessionAppendBlob(&p->rebase, (u8*)zTab, (int)strlen(zTab)+1, &rc);

  199815.       p->bRebaseStarted = 1;

  199816.     }

  199817. 

  199818.     assert( eType==SQLITE_CHANGESET_REPLACE||eType==SQLITE_CHANGESET_OMIT );

  199819.     assert( eOp==SQLITE_DELETE || eOp==SQLITE_INSERT || eOp==SQLITE_UPDATE );

  199820. 

  199821.     sessionAppendByte(&p->rebase, 

  199822.         (eOp==SQLITE_DELETE ? SQLITE_DELETE : SQLITE_INSERT), &rc

  199823.         );

  199824.     sessionAppendByte(&p->rebase, (eType==SQLITE_CHANGESET_REPLACE), &rc);

  199825.     for(i=0; i<p->nCol; i++){

  199826.       sqlite3_value *pVal = 0;

  199827.       if( eOp==SQLITE_DELETE || (eOp==SQLITE_UPDATE && p->abPK[i]) ){

  199828.         sqlite3changeset_old(pIter, i, &pVal);

  199829.       }else{

  199830.         sqlite3changeset_new(pIter, i, &pVal);

  199831.       }

  199832.       sessionAppendValue(&p->rebase, pVal, &rc);

  199833.     }

  199834.   }

  199835.   return rc;

  199836. }

  199837. 

  199838. /*

  199839. ** Invoke the conflict handler for the change that the changeset iterator

  199840. ** currently points to.

  199841. **

  199842. ** Argument eType must be either CHANGESET_DATA or CHANGESET_CONFLICT.

  199843. ** If argument pbReplace is NULL, then the type of conflict handler invoked

  199844. ** depends solely on eType, as follows:

  199845. **

  199846. **    eType value                 Value passed to xConflict

  199847. **    -------------------------------------------------

  199848. **    CHANGESET_DATA              CHANGESET_NOTFOUND

  199849. **    CHANGESET_CONFLICT          CHANGESET_CONSTRAINT

  199850. **

  199851. ** Or, if pbReplace is not NULL, then an attempt is made to find an existing

  199852. ** record with the same primary key as the record about to be deleted, updated

  199853. ** or inserted. If such a record can be found, it is available to the conflict

  199854. ** handler as the "conflicting" record. In this case the type of conflict

  199855. ** handler invoked is as follows:

  199856. **

  199857. **    eType value         PK Record found?   Value passed to xConflict

  199858. **    ----------------------------------------------------------------

  199859. **    CHANGESET_DATA      Yes                CHANGESET_DATA

  199860. **    CHANGESET_DATA      No                 CHANGESET_NOTFOUND

  199861. **    CHANGESET_CONFLICT  Yes                CHANGESET_CONFLICT

  199862. **    CHANGESET_CONFLICT  No                 CHANGESET_CONSTRAINT

  199863. **

  199864. ** If pbReplace is not NULL, and a record with a matching PK is found, and

  199865. ** the conflict handler function returns SQLITE_CHANGESET_REPLACE, *pbReplace

  199866. ** is set to non-zero before returning SQLITE_OK.

  199867. **

  199868. ** If the conflict handler returns SQLITE_CHANGESET_ABORT, SQLITE_ABORT is

  199869. ** returned. Or, if the conflict handler returns an invalid value, 

  199870. ** SQLITE_MISUSE. If the conflict handler returns SQLITE_CHANGESET_OMIT,

  199871. ** this function returns SQLITE_OK.

  199872. */

  199873. static int sessionConflictHandler(

  199874.   int eType,                      /* Either CHANGESET_DATA or CONFLICT */

  199875.   SessionApplyCtx *p,             /* changeset_apply() context */

  199876.   sqlite3_changeset_iter *pIter,  /* Changeset iterator */

  199877.   int(*xConflict)(void *, int, sqlite3_changeset_iter*),

  199878.   void *pCtx,                     /* First argument for conflict handler */

  199879.   int *pbReplace                  /* OUT: Set to true if PK row is found */

  199880. ){

  199881.   int res = 0;                    /* Value returned by conflict handler */

  199882.   int rc;

  199883.   int nCol;

  199884.   int op;

  199885.   const char *zDummy;

  199886. 

  199887.   sqlite3changeset_op(pIter, &zDummy, &nCol, &op, 0);

  199888. 

  199889.   assert( eType==SQLITE_CHANGESET_CONFLICT || eType==SQLITE_CHANGESET_DATA );

  199890.   assert( SQLITE_CHANGESET_CONFLICT+1==SQLITE_CHANGESET_CONSTRAINT );

  199891.   assert( SQLITE_CHANGESET_DATA+1==SQLITE_CHANGESET_NOTFOUND );

  199892. 

  199893.   /* Bind the new.* PRIMARY KEY values to the SELECT statement. */

  199894.   if( pbReplace ){

  199895.     rc = sessionSeekToRow(p->db, pIter, p->abPK, p->pSelect);

  199896.   }else{

  199897.     rc = SQLITE_OK;

  199898.   }

  199899. 

  199900.   if( rc==SQLITE_ROW ){

  199901.     /* There exists another row with the new.* primary key. */

  199902.     pIter->pConflict = p->pSelect;

  199903.     res = xConflict(pCtx, eType, pIter);

  199904.     pIter->pConflict = 0;

  199905.     rc = sqlite3_reset(p->pSelect);

  199906.   }else if( rc==SQLITE_OK ){

  199907.     if( p->bDeferConstraints && eType==SQLITE_CHANGESET_CONFLICT ){

  199908.       /* Instead of invoking the conflict handler, append the change blob

  199909.       ** to the SessionApplyCtx.constraints buffer. */

  199910.       u8 *aBlob = &pIter->in.aData[pIter->in.iCurrent];

  199911.       int nBlob = pIter->in.iNext - pIter->in.iCurrent;

  199912.       sessionAppendBlob(&p->constraints, aBlob, nBlob, &rc);

  199913.       return SQLITE_OK;

  199914.     }else{

  199915.       /* No other row with the new.* primary key. */

  199916.       res = xConflict(pCtx, eType+1, pIter);

  199917.       if( res==SQLITE_CHANGESET_REPLACE ) rc = SQLITE_MISUSE;

  199918.     }

  199919.   }

  199920. 

  199921.   if( rc==SQLITE_OK ){

  199922.     switch( res ){

  199923.       case SQLITE_CHANGESET_REPLACE:

  199924.         assert( pbReplace );

  199925.         *pbReplace = 1;

  199926.         break;

  199927. 

  199928.       case SQLITE_CHANGESET_OMIT:

  199929.         break;

  199930. 

  199931.       case SQLITE_CHANGESET_ABORT:

  199932.         rc = SQLITE_ABORT;

  199933.         break;

  199934. 

  199935.       default:

  199936.         rc = SQLITE_MISUSE;

  199937.         break;

  199938.     }

  199939.     if( rc==SQLITE_OK ){

  199940.       rc = sessionRebaseAdd(p, res, pIter);

  199941.     }

  199942.   }

  199943. 

  199944.   return rc;

  199945. }

  199946. 

  199947. /*

  199948. ** Attempt to apply the change that the iterator passed as the first argument

  199949. ** currently points to to the database. If a conflict is encountered, invoke

  199950. ** the conflict handler callback.

  199951. **

  199952. ** If argument pbRetry is NULL, then ignore any CHANGESET_DATA conflict. If

  199953. ** one is encountered, update or delete the row with the matching primary key

  199954. ** instead. Or, if pbRetry is not NULL and a CHANGESET_DATA conflict occurs,

  199955. ** invoke the conflict handler. If it returns CHANGESET_REPLACE, set *pbRetry

  199956. ** to true before returning. In this case the caller will invoke this function

  199957. ** again, this time with pbRetry set to NULL.

  199958. **

  199959. ** If argument pbReplace is NULL and a CHANGESET_CONFLICT conflict is 

  199960. ** encountered invoke the conflict handler with CHANGESET_CONSTRAINT instead.

  199961. ** Or, if pbReplace is not NULL, invoke it with CHANGESET_CONFLICT. If such

  199962. ** an invocation returns SQLITE_CHANGESET_REPLACE, set *pbReplace to true

  199963. ** before retrying. In this case the caller attempts to remove the conflicting

  199964. ** row before invoking this function again, this time with pbReplace set 

  199965. ** to NULL.

  199966. **

  199967. ** If any conflict handler returns SQLITE_CHANGESET_ABORT, this function

  199968. ** returns SQLITE_ABORT. Otherwise, if no error occurs, SQLITE_OK is 

  199969. ** returned.

  199970. */

  199971. static int sessionApplyOneOp(

  199972.   sqlite3_changeset_iter *pIter,  /* Changeset iterator */

  199973.   SessionApplyCtx *p,             /* changeset_apply() context */

  199974.   int(*xConflict)(void *, int, sqlite3_changeset_iter *),

  199975.   void *pCtx,                     /* First argument for the conflict handler */

  199976.   int *pbReplace,                 /* OUT: True to remove PK row and retry */

  199977.   int *pbRetry                    /* OUT: True to retry. */

  199978. ){

  199979.   const char *zDummy;

  199980.   int op;

  199981.   int nCol;

  199982.   int rc = SQLITE_OK;

  199983. 

  199984.   assert( p->pDelete && p->pUpdate && p->pInsert && p->pSelect );

  199985.   assert( p->azCol && p->abPK );

  199986.   assert( !pbReplace || *pbReplace==0 );

  199987. 

  199988.   sqlite3changeset_op(pIter, &zDummy, &nCol, &op, 0);

  199989. 

  199990.   if( op==SQLITE_DELETE ){

  199991. 

  199992.     /* Bind values to the DELETE statement. If conflict handling is required,

  199993.     ** bind values for all columns and set bound variable (nCol+1) to true.

  199994.     ** Or, if conflict handling is not required, bind just the PK column

  199995.     ** values and, if it exists, set (nCol+1) to false. Conflict handling

  199996.     ** is not required if:

  199997.     **

  199998.     **   * this is a patchset, or

  199999.     **   * (pbRetry==0), or

  200000.     **   * all columns of the table are PK columns (in this case there is

  200001.     **     no (nCol+1) variable to bind to).

  200002.     */

  200003.     u8 *abPK = (pIter->bPatchset ? p->abPK : 0);

  200004.     rc = sessionBindRow(pIter, sqlite3changeset_old, nCol, abPK, p->pDelete);

  200005.     if( rc==SQLITE_OK && sqlite3_bind_parameter_count(p->pDelete)>nCol ){

  200006.       rc = sqlite3_bind_int(p->pDelete, nCol+1, (pbRetry==0 || abPK));

  200007.     }

  200008.     if( rc!=SQLITE_OK ) return rc;

  200009. 

  200010.     sqlite3_step(p->pDelete);

  200011.     rc = sqlite3_reset(p->pDelete);

  200012.     if( rc==SQLITE_OK && sqlite3_changes(p->db)==0 ){

  200013.       rc = sessionConflictHandler(

  200014.           SQLITE_CHANGESET_DATA, p, pIter, xConflict, pCtx, pbRetry

  200015.       );

  200016.     }else if( (rc&0xff)==SQLITE_CONSTRAINT ){

  200017.       rc = sessionConflictHandler(

  200018.           SQLITE_CHANGESET_CONFLICT, p, pIter, xConflict, pCtx, 0

  200019.       );

  200020.     }

  200021. 

  200022.   }else if( op==SQLITE_UPDATE ){

  200023.     int i;

  200024. 

  200025.     /* Bind values to the UPDATE statement. */

  200026.     for(i=0; rc==SQLITE_OK && i<nCol; i++){

  200027.       sqlite3_value *pOld = sessionChangesetOld(pIter, i);

  200028.       sqlite3_value *pNew = sessionChangesetNew(pIter, i);

  200029. 

  200030.       sqlite3_bind_int(p->pUpdate, i*3+2, !!pNew);

  200031.       if( pOld ){

  200032.         rc = sessionBindValue(p->pUpdate, i*3+1, pOld);

  200033.       }

  200034.       if( rc==SQLITE_OK && pNew ){

  200035.         rc = sessionBindValue(p->pUpdate, i*3+3, pNew);

  200036.       }

  200037.     }

  200038.     if( rc==SQLITE_OK ){

  200039.       sqlite3_bind_int(p->pUpdate, nCol*3+1, pbRetry==0 || pIter->bPatchset);

  200040.     }

  200041.     if( rc!=SQLITE_OK ) return rc;

  200042. 

  200043.     /* Attempt the UPDATE. In the case of a NOTFOUND or DATA conflict,

  200044.     ** the result will be SQLITE_OK with 0 rows modified. */

  200045.     sqlite3_step(p->pUpdate);

  200046.     rc = sqlite3_reset(p->pUpdate);

  200047. 

  200048.     if( rc==SQLITE_OK && sqlite3_changes(p->db)==0 ){

  200049.       /* A NOTFOUND or DATA error. Search the table to see if it contains

  200050.       ** a row with a matching primary key. If so, this is a DATA conflict.

  200051.       ** Otherwise, if there is no primary key match, it is a NOTFOUND. */

  200052. 

  200053.       rc = sessionConflictHandler(

  200054.           SQLITE_CHANGESET_DATA, p, pIter, xConflict, pCtx, pbRetry

  200055.       );

  200056. 

  200057.     }else if( (rc&0xff)==SQLITE_CONSTRAINT ){

  200058.       /* This is always a CONSTRAINT conflict. */

  200059.       rc = sessionConflictHandler(

  200060.           SQLITE_CHANGESET_CONFLICT, p, pIter, xConflict, pCtx, 0

  200061.       );

  200062.     }

  200063. 

  200064.   }else{

  200065.     assert( op==SQLITE_INSERT );

  200066.     if( p->bStat1 ){

  200067.       /* Check if there is a conflicting row. For sqlite_stat1, this needs

  200068.       ** to be done using a SELECT, as there is no PRIMARY KEY in the 

  200069.       ** database schema to throw an exception if a duplicate is inserted.  */

  200070.       rc = sessionSeekToRow(p->db, pIter, p->abPK, p->pSelect);

  200071.       if( rc==SQLITE_ROW ){

  200072.         rc = SQLITE_CONSTRAINT;

  200073.         sqlite3_reset(p->pSelect);

  200074.       }

  200075.     }

  200076. 

  200077.     if( rc==SQLITE_OK ){

  200078.       rc = sessionBindRow(pIter, sqlite3changeset_new, nCol, 0, p->pInsert);

  200079.       if( rc!=SQLITE_OK ) return rc;

  200080. 

  200081.       sqlite3_step(p->pInsert);

  200082.       rc = sqlite3_reset(p->pInsert);

  200083.     }

  200084. 

  200085.     if( (rc&0xff)==SQLITE_CONSTRAINT ){

  200086.       rc = sessionConflictHandler(

  200087.           SQLITE_CHANGESET_CONFLICT, p, pIter, xConflict, pCtx, pbReplace

  200088.       );

  200089.     }

  200090.   }

  200091. 

  200092.   return rc;

  200093. }

  200094. 

  200095. /*

  200096. ** Attempt to apply the change that the iterator passed as the first argument

  200097. ** currently points to to the database. If a conflict is encountered, invoke

  200098. ** the conflict handler callback.

  200099. **

  200100. ** The difference between this function and sessionApplyOne() is that this

  200101. ** function handles the case where the conflict-handler is invoked and 

  200102. ** returns SQLITE_CHANGESET_REPLACE - indicating that the change should be

  200103. ** retried in some manner.

  200104. */

  200105. static int sessionApplyOneWithRetry(

  200106.   sqlite3 *db,                    /* Apply change to "main" db of this handle */

  200107.   sqlite3_changeset_iter *pIter,  /* Changeset iterator to read change from */

  200108.   SessionApplyCtx *pApply,        /* Apply context */

  200109.   int(*xConflict)(void*, int, sqlite3_changeset_iter*),

  200110.   void *pCtx                      /* First argument passed to xConflict */

  200111. ){

  200112.   int bReplace = 0;

  200113.   int bRetry = 0;

  200114.   int rc;

  200115. 

  200116.   rc = sessionApplyOneOp(pIter, pApply, xConflict, pCtx, &bReplace, &bRetry);

  200117.   if( rc==SQLITE_OK ){

  200118.     /* If the bRetry flag is set, the change has not been applied due to an

  200119.     ** SQLITE_CHANGESET_DATA problem (i.e. this is an UPDATE or DELETE and

  200120.     ** a row with the correct PK is present in the db, but one or more other

  200121.     ** fields do not contain the expected values) and the conflict handler 

  200122.     ** returned SQLITE_CHANGESET_REPLACE. In this case retry the operation,

  200123.     ** but pass NULL as the final argument so that sessionApplyOneOp() ignores

  200124.     ** the SQLITE_CHANGESET_DATA problem.  */

  200125.     if( bRetry ){

  200126.       assert( pIter->op==SQLITE_UPDATE || pIter->op==SQLITE_DELETE );

  200127.       rc = sessionApplyOneOp(pIter, pApply, xConflict, pCtx, 0, 0);

  200128.     }

  200129. 

  200130.     /* If the bReplace flag is set, the change is an INSERT that has not

  200131.     ** been performed because the database already contains a row with the

  200132.     ** specified primary key and the conflict handler returned

  200133.     ** SQLITE_CHANGESET_REPLACE. In this case remove the conflicting row

  200134.     ** before reattempting the INSERT.  */

  200135.     else if( bReplace ){

  200136.       assert( pIter->op==SQLITE_INSERT );

  200137.       rc = sqlite3_exec(db, "SAVEPOINT replace_op", 0, 0, 0);

  200138.       if( rc==SQLITE_OK ){

  200139.         rc = sessionBindRow(pIter, 

  200140.             sqlite3changeset_new, pApply->nCol, pApply->abPK, pApply->pDelete);

  200141.         sqlite3_bind_int(pApply->pDelete, pApply->nCol+1, 1);

  200142.       }

  200143.       if( rc==SQLITE_OK ){

  200144.         sqlite3_step(pApply->pDelete);

  200145.         rc = sqlite3_reset(pApply->pDelete);

  200146.       }

  200147.       if( rc==SQLITE_OK ){

  200148.         rc = sessionApplyOneOp(pIter, pApply, xConflict, pCtx, 0, 0);

  200149.       }

  200150.       if( rc==SQLITE_OK ){

  200151.         rc = sqlite3_exec(db, "RELEASE replace_op", 0, 0, 0);

  200152.       }

  200153.     }

  200154.   }

  200155. 

  200156.   return rc;

  200157. }

  200158. 

  200159. /*

  200160. ** Retry the changes accumulated in the pApply->constraints buffer.

  200161. */

  200162. static int sessionRetryConstraints(

  200163.   sqlite3 *db, 

  200164.   int bPatchset,

  200165.   const char *zTab,

  200166.   SessionApplyCtx *pApply,

  200167.   int(*xConflict)(void*, int, sqlite3_changeset_iter*),

  200168.   void *pCtx                      /* First argument passed to xConflict */

  200169. ){

  200170.   int rc = SQLITE_OK;

  200171. 

  200172.   while( pApply->constraints.nBuf ){

  200173.     sqlite3_changeset_iter *pIter2 = 0;

  200174.     SessionBuffer cons = pApply->constraints;

  200175.     memset(&pApply->constraints, 0, sizeof(SessionBuffer));

  200176. 

  200177.     rc = sessionChangesetStart(&pIter2, 0, 0, cons.nBuf, cons.aBuf, 0);

  200178.     if( rc==SQLITE_OK ){

  200179.       size_t nByte = 2*pApply->nCol*sizeof(sqlite3_value*);

  200180.       int rc2;

  200181.       pIter2->bPatchset = bPatchset;

  200182.       pIter2->zTab = (char*)zTab;

  200183.       pIter2->nCol = pApply->nCol;

  200184.       pIter2->abPK = pApply->abPK;

  200185.       sessionBufferGrow(&pIter2->tblhdr, nByte, &rc);

  200186.       pIter2->apValue = (sqlite3_value**)pIter2->tblhdr.aBuf;

  200187.       if( rc==SQLITE_OK ) memset(pIter2->apValue, 0, nByte);

  200188. 

  200189.       while( rc==SQLITE_OK && SQLITE_ROW==sqlite3changeset_next(pIter2) ){

  200190.         rc = sessionApplyOneWithRetry(db, pIter2, pApply, xConflict, pCtx);

  200191.       }

  200192. 

  200193.       rc2 = sqlite3changeset_finalize(pIter2);

  200194.       if( rc==SQLITE_OK ) rc = rc2;

  200195.     }

  200196.     assert( pApply->bDeferConstraints || pApply->constraints.nBuf==0 );

  200197. 

  200198.     sqlite3_free(cons.aBuf);

  200199.     if( rc!=SQLITE_OK ) break;

  200200.     if( pApply->constraints.nBuf>=cons.nBuf ){

  200201.       /* No progress was made on the last round. */

  200202.       pApply->bDeferConstraints = 0;

  200203.     }

  200204.   }

  200205. 

  200206.   return rc;

  200207. }

  200208. 

  200209. /*

  200210. ** Argument pIter is a changeset iterator that has been initialized, but

  200211. ** not yet passed to sqlite3changeset_next(). This function applies the 

  200212. ** changeset to the main database attached to handle "db". The supplied

  200213. ** conflict handler callback is invoked to resolve any conflicts encountered

  200214. ** while applying the change.

  200215. */

  200216. static int sessionChangesetApply(

  200217.   sqlite3 *db,                    /* Apply change to "main" db of this handle */

  200218.   sqlite3_changeset_iter *pIter,  /* Changeset to apply */

  200219.   int(*xFilter)(

  200220.     void *pCtx,                   /* Copy of sixth arg to _apply() */

  200221.     const char *zTab              /* Table name */

  200222.   ),

  200223.   int(*xConflict)(

  200224.     void *pCtx,                   /* Copy of fifth arg to _apply() */

  200225.     int eConflict,                /* DATA, MISSING, CONFLICT, CONSTRAINT */

  200226.     sqlite3_changeset_iter *p     /* Handle describing change and conflict */

  200227.   ),

  200228.   void *pCtx,                     /* First argument passed to xConflict */

  200229.   void **ppRebase, int *pnRebase, /* OUT: Rebase information */

  200230.   int flags                       /* SESSION_APPLY_XXX flags */

  200231. ){

  200232.   int schemaMismatch = 0;

  200233.   int rc = SQLITE_OK;             /* Return code */

  200234.   const char *zTab = 0;           /* Name of current table */

  200235.   int nTab = 0;                   /* Result of sqlite3Strlen30(zTab) */

  200236.   SessionApplyCtx sApply;         /* changeset_apply() context object */

  200237.   int bPatchset;

  200238. 

  200239.   assert( xConflict!=0 );

  200240. 

  200241.   pIter->in.bNoDiscard = 1;

  200242.   memset(&sApply, 0, sizeof(sApply));

  200243.   sApply.bRebase = (ppRebase && pnRebase);

  200244.   sqlite3_mutex_enter(sqlite3_db_mutex(db));

  200245.   if( (flags & SQLITE_CHANGESETAPPLY_NOSAVEPOINT)==0 ){

  200246.     rc = sqlite3_exec(db, "SAVEPOINT changeset_apply", 0, 0, 0);

  200247.   }

  200248.   if( rc==SQLITE_OK ){

  200249.     rc = sqlite3_exec(db, "PRAGMA defer_foreign_keys = 1", 0, 0, 0);

  200250.   }

  200251.   while( rc==SQLITE_OK && SQLITE_ROW==sqlite3changeset_next(pIter) ){

  200252.     int nCol;

  200253.     int op;

  200254.     const char *zNew;

  200255.     

  200256.     sqlite3changeset_op(pIter, &zNew, &nCol, &op, 0);

  200257. 

  200258.     if( zTab==0 || sqlite3_strnicmp(zNew, zTab, nTab+1) ){

  200259.       u8 *abPK;

  200260. 

  200261.       rc = sessionRetryConstraints(

  200262.           db, pIter->bPatchset, zTab, &sApply, xConflict, pCtx

  200263.       );

  200264.       if( rc!=SQLITE_OK ) break;

  200265. 

  200266.       sqlite3_free((char*)sApply.azCol);  /* cast works around VC++ bug */

  200267.       sqlite3_finalize(sApply.pDelete);

  200268.       sqlite3_finalize(sApply.pUpdate); 

  200269.       sqlite3_finalize(sApply.pInsert);

  200270.       sqlite3_finalize(sApply.pSelect);

  200271.       sApply.db = db;

  200272.       sApply.pDelete = 0;

  200273.       sApply.pUpdate = 0;

  200274.       sApply.pInsert = 0;

  200275.       sApply.pSelect = 0;

  200276.       sApply.nCol = 0;

  200277.       sApply.azCol = 0;

  200278.       sApply.abPK = 0;

  200279.       sApply.bStat1 = 0;

  200280.       sApply.bDeferConstraints = 1;

  200281.       sApply.bRebaseStarted = 0;

  200282.       memset(&sApply.constraints, 0, sizeof(SessionBuffer));

  200283. 

  200284.       /* If an xFilter() callback was specified, invoke it now. If the 

  200285.       ** xFilter callback returns zero, skip this table. If it returns

  200286.       ** non-zero, proceed. */

  200287.       schemaMismatch = (xFilter && (0==xFilter(pCtx, zNew)));

  200288.       if( schemaMismatch ){

  200289.         zTab = sqlite3_mprintf("%s", zNew);

  200290.         if( zTab==0 ){

  200291.           rc = SQLITE_NOMEM;

  200292.           break;

  200293.         }

  200294.         nTab = (int)strlen(zTab);

  200295.         sApply.azCol = (const char **)zTab;

  200296.       }else{

  200297.         int nMinCol = 0;

  200298.         int i;

  200299. 

  200300.         sqlite3changeset_pk(pIter, &abPK, 0);

  200301.         rc = sessionTableInfo(

  200302.             db, "main", zNew, &sApply.nCol, &zTab, &sApply.azCol, &sApply.abPK

  200303.         );

  200304.         if( rc!=SQLITE_OK ) break;

  200305.         for(i=0; i<sApply.nCol; i++){

  200306.           if( sApply.abPK[i] ) nMinCol = i+1;

  200307.         }

  200308.   

  200309.         if( sApply.nCol==0 ){

  200310.           schemaMismatch = 1;

  200311.           sqlite3_log(SQLITE_SCHEMA, 

  200312.               "sqlite3changeset_apply(): no such table: %s", zTab

  200313.           );

  200314.         }

  200315.         else if( sApply.nCol<nCol ){

  200316.           schemaMismatch = 1;

  200317.           sqlite3_log(SQLITE_SCHEMA, 

  200318.               "sqlite3changeset_apply(): table %s has %d columns, "

  200319.               "expected %d or more", 

  200320.               zTab, sApply.nCol, nCol

  200321.           );

  200322.         }

  200323.         else if( nCol<nMinCol || memcmp(sApply.abPK, abPK, nCol)!=0 ){

  200324.           schemaMismatch = 1;

  200325.           sqlite3_log(SQLITE_SCHEMA, "sqlite3changeset_apply(): "

  200326.               "primary key mismatch for table %s", zTab

  200327.           );

  200328.         }

  200329.         else{

  200330.           sApply.nCol = nCol;

  200331.           if( 0==sqlite3_stricmp(zTab, "sqlite_stat1") ){

  200332.             if( (rc = sessionStat1Sql(db, &sApply) ) ){

  200333.               break;

  200334.             }

  200335.             sApply.bStat1 = 1;

  200336.           }else{

  200337.             if((rc = sessionSelectRow(db, zTab, &sApply))

  200338.                 || (rc = sessionUpdateRow(db, zTab, &sApply))

  200339.                 || (rc = sessionDeleteRow(db, zTab, &sApply))

  200340.                 || (rc = sessionInsertRow(db, zTab, &sApply))

  200341.               ){

  200342.               break;

  200343.             }

  200344.             sApply.bStat1 = 0;

  200345.           }

  200346.         }

  200347.         nTab = sqlite3Strlen30(zTab);

  200348.       }

  200349.     }

  200350. 

  200351.     /* If there is a schema mismatch on the current table, proceed to the

  200352.     ** next change. A log message has already been issued. */

  200353.     if( schemaMismatch ) continue;

  200354. 

  200355.     rc = sessionApplyOneWithRetry(db, pIter, &sApply, xConflict, pCtx);

  200356.   }

  200357. 

  200358.   bPatchset = pIter->bPatchset;

  200359.   if( rc==SQLITE_OK ){

  200360.     rc = sqlite3changeset_finalize(pIter);

  200361.   }else{

  200362.     sqlite3changeset_finalize(pIter);

  200363.   }

  200364. 

  200365.   if( rc==SQLITE_OK ){

  200366.     rc = sessionRetryConstraints(db, bPatchset, zTab, &sApply, xConflict, pCtx);

  200367.   }

  200368. 

  200369.   if( rc==SQLITE_OK ){

  200370.     int nFk, notUsed;

  200371.     sqlite3_db_status(db, SQLITE_DBSTATUS_DEFERRED_FKS, &nFk, &notUsed, 0);

  200372.     if( nFk!=0 ){

  200373.       int res = SQLITE_CHANGESET_ABORT;

  200374.       sqlite3_changeset_iter sIter;

  200375.       memset(&sIter, 0, sizeof(sIter));

  200376.       sIter.nCol = nFk;

  200377.       res = xConflict(pCtx, SQLITE_CHANGESET_FOREIGN_KEY, &sIter);

  200378.       if( res!=SQLITE_CHANGESET_OMIT ){

  200379.         rc = SQLITE_CONSTRAINT;

  200380.       }

  200381.     }

  200382.   }

  200383.   sqlite3_exec(db, "PRAGMA defer_foreign_keys = 0", 0, 0, 0);

  200384. 

  200385.   if( (flags & SQLITE_CHANGESETAPPLY_NOSAVEPOINT)==0 ){

  200386.     if( rc==SQLITE_OK ){

  200387.       rc = sqlite3_exec(db, "RELEASE changeset_apply", 0, 0, 0);

  200388.     }else{

  200389.       sqlite3_exec(db, "ROLLBACK TO changeset_apply", 0, 0, 0);

  200390.       sqlite3_exec(db, "RELEASE changeset_apply", 0, 0, 0);

  200391.     }

  200392.   }

  200393. 

  200394.   assert( sApply.bRebase || sApply.rebase.nBuf==0 );

  200395.   if( rc==SQLITE_OK && bPatchset==0 && sApply.bRebase ){

  200396.     *ppRebase = (void*)sApply.rebase.aBuf;

  200397.     *pnRebase = sApply.rebase.nBuf;

  200398.     sApply.rebase.aBuf = 0;

  200399.   }

  200400.   sqlite3_finalize(sApply.pInsert);

  200401.   sqlite3_finalize(sApply.pDelete);

  200402.   sqlite3_finalize(sApply.pUpdate);

  200403.   sqlite3_finalize(sApply.pSelect);

  200404.   sqlite3_free((char*)sApply.azCol);  /* cast works around VC++ bug */

  200405.   sqlite3_free((char*)sApply.constraints.aBuf);

  200406.   sqlite3_free((char*)sApply.rebase.aBuf);

  200407.   sqlite3_mutex_leave(sqlite3_db_mutex(db));

  200408.   return rc;

  200409. }

  200410. 

  200411. /*

  200412. ** Apply the changeset passed via pChangeset/nChangeset to the main 

  200413. ** database attached to handle "db".

  200414. */

  200415. SQLITE_API int sqlite3changeset_apply_v2(

  200416.   sqlite3 *db,                    /* Apply change to "main" db of this handle */

  200417.   int nChangeset,                 /* Size of changeset in bytes */

  200418.   void *pChangeset,               /* Changeset blob */

  200419.   int(*xFilter)(

  200420.     void *pCtx,                   /* Copy of sixth arg to _apply() */

  200421.     const char *zTab              /* Table name */

  200422.   ),

  200423.   int(*xConflict)(

  200424.     void *pCtx,                   /* Copy of sixth arg to _apply() */

  200425.     int eConflict,                /* DATA, MISSING, CONFLICT, CONSTRAINT */

  200426.     sqlite3_changeset_iter *p     /* Handle describing change and conflict */

  200427.   ),

  200428.   void *pCtx,                     /* First argument passed to xConflict */

  200429.   void **ppRebase, int *pnRebase,

  200430.   int flags

  200431. ){

  200432.   sqlite3_changeset_iter *pIter;  /* Iterator to skip through changeset */  

  200433.   int bInverse = !!(flags & SQLITE_CHANGESETAPPLY_INVERT);

  200434.   int rc = sessionChangesetStart(&pIter, 0, 0, nChangeset, pChangeset,bInverse);

  200435.   if( rc==SQLITE_OK ){

  200436.     rc = sessionChangesetApply(

  200437.         db, pIter, xFilter, xConflict, pCtx, ppRebase, pnRebase, flags

  200438.     );

  200439.   }

  200440.   return rc;

  200441. }

  200442. 

  200443. /*

  200444. ** Apply the changeset passed via pChangeset/nChangeset to the main database

  200445. ** attached to handle "db". Invoke the supplied conflict handler callback

  200446. ** to resolve any conflicts encountered while applying the change.

  200447. */

  200448. SQLITE_API int sqlite3changeset_apply(

  200449.   sqlite3 *db,                    /* Apply change to "main" db of this handle */

  200450.   int nChangeset,                 /* Size of changeset in bytes */

  200451.   void *pChangeset,               /* Changeset blob */

  200452.   int(*xFilter)(

  200453.     void *pCtx,                   /* Copy of sixth arg to _apply() */

  200454.     const char *zTab              /* Table name */

  200455.   ),

  200456.   int(*xConflict)(

  200457.     void *pCtx,                   /* Copy of fifth arg to _apply() */

  200458.     int eConflict,                /* DATA, MISSING, CONFLICT, CONSTRAINT */

  200459.     sqlite3_changeset_iter *p     /* Handle describing change and conflict */

  200460.   ),

  200461.   void *pCtx                      /* First argument passed to xConflict */

  200462. ){

  200463.   return sqlite3changeset_apply_v2(

  200464.       db, nChangeset, pChangeset, xFilter, xConflict, pCtx, 0, 0, 0

  200465.   );

  200466. }

  200467. 

  200468. /*

  200469. ** Apply the changeset passed via xInput/pIn to the main database

  200470. ** attached to handle "db". Invoke the supplied conflict handler callback

  200471. ** to resolve any conflicts encountered while applying the change.

  200472. */

  200473. SQLITE_API int sqlite3changeset_apply_v2_strm(

  200474.   sqlite3 *db,                    /* Apply change to "main" db of this handle */

  200475.   int (*xInput)(void *pIn, void *pData, int *pnData), /* Input function */

  200476.   void *pIn,                                          /* First arg for xInput */

  200477.   int(*xFilter)(

  200478.     void *pCtx,                   /* Copy of sixth arg to _apply() */

  200479.     const char *zTab              /* Table name */

  200480.   ),

  200481.   int(*xConflict)(

  200482.     void *pCtx,                   /* Copy of sixth arg to _apply() */

  200483.     int eConflict,                /* DATA, MISSING, CONFLICT, CONSTRAINT */

  200484.     sqlite3_changeset_iter *p     /* Handle describing change and conflict */

  200485.   ),

  200486.   void *pCtx,                     /* First argument passed to xConflict */

  200487.   void **ppRebase, int *pnRebase,

  200488.   int flags

  200489. ){

  200490.   sqlite3_changeset_iter *pIter;  /* Iterator to skip through changeset */  

  200491.   int bInverse = !!(flags & SQLITE_CHANGESETAPPLY_INVERT);

  200492.   int rc = sessionChangesetStart(&pIter, xInput, pIn, 0, 0, bInverse);

  200493.   if( rc==SQLITE_OK ){

  200494.     rc = sessionChangesetApply(

  200495.         db, pIter, xFilter, xConflict, pCtx, ppRebase, pnRebase, flags

  200496.     );

  200497.   }

  200498.   return rc;

  200499. }

  200500. SQLITE_API int sqlite3changeset_apply_strm(

  200501.   sqlite3 *db,                    /* Apply change to "main" db of this handle */

  200502.   int (*xInput)(void *pIn, void *pData, int *pnData), /* Input function */

  200503.   void *pIn,                                          /* First arg for xInput */

  200504.   int(*xFilter)(

  200505.     void *pCtx,                   /* Copy of sixth arg to _apply() */

  200506.     const char *zTab              /* Table name */

  200507.   ),

  200508.   int(*xConflict)(

  200509.     void *pCtx,                   /* Copy of sixth arg to _apply() */

  200510.     int eConflict,                /* DATA, MISSING, CONFLICT, CONSTRAINT */

  200511.     sqlite3_changeset_iter *p     /* Handle describing change and conflict */

  200512.   ),

  200513.   void *pCtx                      /* First argument passed to xConflict */

  200514. ){

  200515.   return sqlite3changeset_apply_v2_strm(

  200516.       db, xInput, pIn, xFilter, xConflict, pCtx, 0, 0, 0

  200517.   );

  200518. }

  200519. 

  200520. /*

  200521. ** sqlite3_changegroup handle.

  200522. */

  200523. struct sqlite3_changegroup {

  200524.   int rc;                         /* Error code */

  200525.   int bPatch;                     /* True to accumulate patchsets */

  200526.   SessionTable *pList;            /* List of tables in current patch */

  200527. };

  200528. 

  200529. /*

  200530. ** This function is called to merge two changes to the same row together as

  200531. ** part of an sqlite3changeset_concat() operation. A new change object is

  200532. ** allocated and a pointer to it stored in *ppNew.

  200533. */

  200534. static int sessionChangeMerge(

  200535.   SessionTable *pTab,             /* Table structure */

  200536.   int bRebase,                    /* True for a rebase hash-table */

  200537.   int bPatchset,                  /* True for patchsets */

  200538.   SessionChange *pExist,          /* Existing change */

  200539.   int op2,                        /* Second change operation */

  200540.   int bIndirect,                  /* True if second change is indirect */

  200541.   u8 *aRec,                       /* Second change record */

  200542.   int nRec,                       /* Number of bytes in aRec */

  200543.   SessionChange **ppNew           /* OUT: Merged change */

  200544. ){

  200545.   SessionChange *pNew = 0;

  200546.   int rc = SQLITE_OK;

  200547. 

  200548.   if( !pExist ){

  200549.     pNew = (SessionChange *)sqlite3_malloc64(sizeof(SessionChange) + nRec);

  200550.     if( !pNew ){

  200551.       return SQLITE_NOMEM;

  200552.     }

  200553.     memset(pNew, 0, sizeof(SessionChange));

  200554.     pNew->op = op2;

  200555.     pNew->bIndirect = bIndirect;

  200556.     pNew->aRecord = (u8*)&pNew[1];

  200557.     if( bIndirect==0 || bRebase==0 ){

  200558.       pNew->nRecord = nRec;

  200559.       memcpy(pNew->aRecord, aRec, nRec);

  200560.     }else{

  200561.       int i;

  200562.       u8 *pIn = aRec;

  200563.       u8 *pOut = pNew->aRecord;

  200564.       for(i=0; i<pTab->nCol; i++){

  200565.         int nIn = sessionSerialLen(pIn);

  200566.         if( *pIn==0 ){

  200567.           *pOut++ = 0;

  200568.         }else if( pTab->abPK[i]==0 ){

  200569.           *pOut++ = 0xFF;

  200570.         }else{

  200571.           memcpy(pOut, pIn, nIn);

  200572.           pOut += nIn;

  200573.         }

  200574.         pIn += nIn;

  200575.       }

  200576.       pNew->nRecord = pOut - pNew->aRecord;

  200577.     }

  200578.   }else if( bRebase ){

  200579.     if( pExist->op==SQLITE_DELETE && pExist->bIndirect ){

  200580.       *ppNew = pExist;

  200581.     }else{

  200582.       sqlite3_int64 nByte = nRec + pExist->nRecord + sizeof(SessionChange);

  200583.       pNew = (SessionChange*)sqlite3_malloc64(nByte);

  200584.       if( pNew==0 ){

  200585.         rc = SQLITE_NOMEM;

  200586.       }else{

  200587.         int i;

  200588.         u8 *a1 = pExist->aRecord;

  200589.         u8 *a2 = aRec;

  200590.         u8 *pOut;

  200591. 

  200592.         memset(pNew, 0, nByte);

  200593.         pNew->bIndirect = bIndirect || pExist->bIndirect;

  200594.         pNew->op = op2;

  200595.         pOut = pNew->aRecord = (u8*)&pNew[1];

  200596. 

  200597.         for(i=0; i<pTab->nCol; i++){

  200598.           int n1 = sessionSerialLen(a1);

  200599.           int n2 = sessionSerialLen(a2);

  200600.           if( *a1==0xFF || (pTab->abPK[i]==0 && bIndirect) ){

  200601.             *pOut++ = 0xFF;

  200602.           }else if( *a2==0 ){

  200603.             memcpy(pOut, a1, n1);

  200604.             pOut += n1;

  200605.           }else{

  200606.             memcpy(pOut, a2, n2);

  200607.             pOut += n2;

  200608.           }

  200609.           a1 += n1;

  200610.           a2 += n2;

  200611.         }

  200612.         pNew->nRecord = pOut - pNew->aRecord;

  200613.       }

  200614.       sqlite3_free(pExist);

  200615.     }

  200616.   }else{

  200617.     int op1 = pExist->op;

  200618. 

  200619.     /* 

  200620.     **   op1=INSERT, op2=INSERT      ->      Unsupported. Discard op2.

  200621.     **   op1=INSERT, op2=UPDATE      ->      INSERT.

  200622.     **   op1=INSERT, op2=DELETE      ->      (none)

  200623.     **

  200624.     **   op1=UPDATE, op2=INSERT      ->      Unsupported. Discard op2.

  200625.     **   op1=UPDATE, op2=UPDATE      ->      UPDATE.

  200626.     **   op1=UPDATE, op2=DELETE      ->      DELETE.

  200627.     **

  200628.     **   op1=DELETE, op2=INSERT      ->      UPDATE.

  200629.     **   op1=DELETE, op2=UPDATE      ->      Unsupported. Discard op2.

  200630.     **   op1=DELETE, op2=DELETE      ->      Unsupported. Discard op2.

  200631.     */   

  200632.     if( (op1==SQLITE_INSERT && op2==SQLITE_INSERT)

  200633.      || (op1==SQLITE_UPDATE && op2==SQLITE_INSERT)

  200634.      || (op1==SQLITE_DELETE && op2==SQLITE_UPDATE)

  200635.      || (op1==SQLITE_DELETE && op2==SQLITE_DELETE)

  200636.     ){

  200637.       pNew = pExist;

  200638.     }else if( op1==SQLITE_INSERT && op2==SQLITE_DELETE ){

  200639.       sqlite3_free(pExist);

  200640.       assert( pNew==0 );

  200641.     }else{

  200642.       u8 *aExist = pExist->aRecord;

  200643.       sqlite3_int64 nByte;

  200644.       u8 *aCsr;

  200645. 

  200646.       /* Allocate a new SessionChange object. Ensure that the aRecord[]

  200647.       ** buffer of the new object is large enough to hold any record that

  200648.       ** may be generated by combining the input records.  */

  200649.       nByte = sizeof(SessionChange) + pExist->nRecord + nRec;

  200650.       pNew = (SessionChange *)sqlite3_malloc64(nByte);

  200651.       if( !pNew ){

  200652.         sqlite3_free(pExist);

  200653.         return SQLITE_NOMEM;

  200654.       }

  200655.       memset(pNew, 0, sizeof(SessionChange));

  200656.       pNew->bIndirect = (bIndirect && pExist->bIndirect);

  200657.       aCsr = pNew->aRecord = (u8 *)&pNew[1];

  200658. 

  200659.       if( op1==SQLITE_INSERT ){             /* INSERT + UPDATE */

  200660.         u8 *a1 = aRec;

  200661.         assert( op2==SQLITE_UPDATE );

  200662.         pNew->op = SQLITE_INSERT;

  200663.         if( bPatchset==0 ) sessionSkipRecord(&a1, pTab->nCol);

  200664.         sessionMergeRecord(&aCsr, pTab->nCol, aExist, a1);

  200665.       }else if( op1==SQLITE_DELETE ){       /* DELETE + INSERT */

  200666.         assert( op2==SQLITE_INSERT );

  200667.         pNew->op = SQLITE_UPDATE;

  200668.         if( bPatchset ){

  200669.           memcpy(aCsr, aRec, nRec);

  200670.           aCsr += nRec;

  200671.         }else{

  200672.           if( 0==sessionMergeUpdate(&aCsr, pTab, bPatchset, aExist, 0,aRec,0) ){

  200673.             sqlite3_free(pNew);

  200674.             pNew = 0;

  200675.           }

  200676.         }

  200677.       }else if( op2==SQLITE_UPDATE ){       /* UPDATE + UPDATE */

  200678.         u8 *a1 = aExist;

  200679.         u8 *a2 = aRec;

  200680.         assert( op1==SQLITE_UPDATE );

  200681.         if( bPatchset==0 ){

  200682.           sessionSkipRecord(&a1, pTab->nCol);

  200683.           sessionSkipRecord(&a2, pTab->nCol);

  200684.         }

  200685.         pNew->op = SQLITE_UPDATE;

  200686.         if( 0==sessionMergeUpdate(&aCsr, pTab, bPatchset, aRec, aExist,a1,a2) ){

  200687.           sqlite3_free(pNew);

  200688.           pNew = 0;

  200689.         }

  200690.       }else{                                /* UPDATE + DELETE */

  200691.         assert( op1==SQLITE_UPDATE && op2==SQLITE_DELETE );

  200692.         pNew->op = SQLITE_DELETE;

  200693.         if( bPatchset ){

  200694.           memcpy(aCsr, aRec, nRec);

  200695.           aCsr += nRec;

  200696.         }else{

  200697.           sessionMergeRecord(&aCsr, pTab->nCol, aRec, aExist);

  200698.         }

  200699.       }

  200700. 

  200701.       if( pNew ){

  200702.         pNew->nRecord = (int)(aCsr - pNew->aRecord);

  200703.       }

  200704.       sqlite3_free(pExist);

  200705.     }

  200706.   }

  200707. 

  200708.   *ppNew = pNew;

  200709.   return rc;

  200710. }

  200711. 

  200712. /*

  200713. ** Add all changes in the changeset traversed by the iterator passed as

  200714. ** the first argument to the changegroup hash tables.

  200715. */

  200716. static int sessionChangesetToHash(

  200717.   sqlite3_changeset_iter *pIter,   /* Iterator to read from */

  200718.   sqlite3_changegroup *pGrp,       /* Changegroup object to add changeset to */

  200719.   int bRebase                      /* True if hash table is for rebasing */

  200720. ){

  200721.   u8 *aRec;

  200722.   int nRec;

  200723.   int rc = SQLITE_OK;

  200724.   SessionTable *pTab = 0;

  200725. 

  200726.   while( SQLITE_ROW==sessionChangesetNext(pIter, &aRec, &nRec, 0) ){

  200727.     const char *zNew;

  200728.     int nCol;

  200729.     int op;

  200730.     int iHash;

  200731.     int bIndirect;

  200732.     SessionChange *pChange;

  200733.     SessionChange *pExist = 0;

  200734.     SessionChange **pp;

  200735. 

  200736.     if( pGrp->pList==0 ){

  200737.       pGrp->bPatch = pIter->bPatchset;

  200738.     }else if( pIter->bPatchset!=pGrp->bPatch ){

  200739.       rc = SQLITE_ERROR;

  200740.       break;

  200741.     }

  200742. 

  200743.     sqlite3changeset_op(pIter, &zNew, &nCol, &op, &bIndirect);

  200744.     if( !pTab || sqlite3_stricmp(zNew, pTab->zName) ){

  200745.       /* Search the list for a matching table */

  200746.       int nNew = (int)strlen(zNew);

  200747.       u8 *abPK;

  200748. 

  200749.       sqlite3changeset_pk(pIter, &abPK, 0);

  200750.       for(pTab = pGrp->pList; pTab; pTab=pTab->pNext){

  200751.         if( 0==sqlite3_strnicmp(pTab->zName, zNew, nNew+1) ) break;

  200752.       }

  200753.       if( !pTab ){

  200754.         SessionTable **ppTab;

  200755. 

  200756.         pTab = sqlite3_malloc64(sizeof(SessionTable) + nCol + nNew+1);

  200757.         if( !pTab ){

  200758.           rc = SQLITE_NOMEM;

  200759.           break;

  200760.         }

  200761.         memset(pTab, 0, sizeof(SessionTable));

  200762.         pTab->nCol = nCol;

  200763.         pTab->abPK = (u8*)&pTab[1];

  200764.         memcpy(pTab->abPK, abPK, nCol);

  200765.         pTab->zName = (char*)&pTab->abPK[nCol];

  200766.         memcpy(pTab->zName, zNew, nNew+1);

  200767. 

  200768.         /* The new object must be linked on to the end of the list, not

  200769.         ** simply added to the start of it. This is to ensure that the

  200770.         ** tables within the output of sqlite3changegroup_output() are in 

  200771.         ** the right order.  */

  200772.         for(ppTab=&pGrp->pList; *ppTab; ppTab=&(*ppTab)->pNext);

  200773.         *ppTab = pTab;

  200774.       }else if( pTab->nCol!=nCol || memcmp(pTab->abPK, abPK, nCol) ){

  200775.         rc = SQLITE_SCHEMA;

  200776.         break;

  200777.       }

  200778.     }

  200779. 

  200780.     if( sessionGrowHash(pIter->bPatchset, pTab) ){

  200781.       rc = SQLITE_NOMEM;

  200782.       break;

  200783.     }

  200784.     iHash = sessionChangeHash(

  200785.         pTab, (pIter->bPatchset && op==SQLITE_DELETE), aRec, pTab->nChange

  200786.     );

  200787. 

  200788.     /* Search for existing entry. If found, remove it from the hash table. 

  200789.     ** Code below may link it back in.

  200790.     */

  200791.     for(pp=&pTab->apChange[iHash]; *pp; pp=&(*pp)->pNext){

  200792.       int bPkOnly1 = 0;

  200793.       int bPkOnly2 = 0;

  200794.       if( pIter->bPatchset ){

  200795.         bPkOnly1 = (*pp)->op==SQLITE_DELETE;

  200796.         bPkOnly2 = op==SQLITE_DELETE;

  200797.       }

  200798.       if( sessionChangeEqual(pTab, bPkOnly1, (*pp)->aRecord, bPkOnly2, aRec) ){

  200799.         pExist = *pp;

  200800.         *pp = (*pp)->pNext;

  200801.         pTab->nEntry--;

  200802.         break;

  200803.       }

  200804.     }

  200805. 

  200806.     rc = sessionChangeMerge(pTab, bRebase, 

  200807.         pIter->bPatchset, pExist, op, bIndirect, aRec, nRec, &pChange

  200808.     );

  200809.     if( rc ) break;

  200810.     if( pChange ){

  200811.       pChange->pNext = pTab->apChange[iHash];

  200812.       pTab->apChange[iHash] = pChange;

  200813.       pTab->nEntry++;

  200814.     }

  200815.   }

  200816. 

  200817.   if( rc==SQLITE_OK ) rc = pIter->rc;

  200818.   return rc;

  200819. }

  200820. 

  200821. /*

  200822. ** Serialize a changeset (or patchset) based on all changesets (or patchsets)

  200823. ** added to the changegroup object passed as the first argument.

  200824. **

  200825. ** If xOutput is not NULL, then the changeset/patchset is returned to the

  200826. ** user via one or more calls to xOutput, as with the other streaming

  200827. ** interfaces. 

  200828. **

  200829. ** Or, if xOutput is NULL, then (*ppOut) is populated with a pointer to a

  200830. ** buffer containing the output changeset before this function returns. In

  200831. ** this case (*pnOut) is set to the size of the output buffer in bytes. It

  200832. ** is the responsibility of the caller to free the output buffer using

  200833. ** sqlite3_free() when it is no longer required.

  200834. **

  200835. ** If successful, SQLITE_OK is returned. Or, if an error occurs, an SQLite

  200836. ** error code. If an error occurs and xOutput is NULL, (*ppOut) and (*pnOut)

  200837. ** are both set to 0 before returning.

  200838. */

  200839. static int sessionChangegroupOutput(

  200840.   sqlite3_changegroup *pGrp,

  200841.   int (*xOutput)(void *pOut, const void *pData, int nData),

  200842.   void *pOut,

  200843.   int *pnOut,

  200844.   void **ppOut

  200845. ){

  200846.   int rc = SQLITE_OK;

  200847.   SessionBuffer buf = {0, 0, 0};

  200848.   SessionTable *pTab;

  200849.   assert( xOutput==0 || (ppOut==0 && pnOut==0) );

  200850. 

  200851.   /* Create the serialized output changeset based on the contents of the

  200852.   ** hash tables attached to the SessionTable objects in list p->pList. 

  200853.   */

  200854.   for(pTab=pGrp->pList; rc==SQLITE_OK && pTab; pTab=pTab->pNext){

  200855.     int i;

  200856.     if( pTab->nEntry==0 ) continue;

  200857. 

  200858.     sessionAppendTableHdr(&buf, pGrp->bPatch, pTab, &rc);

  200859.     for(i=0; i<pTab->nChange; i++){

  200860.       SessionChange *p;

  200861.       for(p=pTab->apChange[i]; p; p=p->pNext){

  200862.         sessionAppendByte(&buf, p->op, &rc);

  200863.         sessionAppendByte(&buf, p->bIndirect, &rc);

  200864.         sessionAppendBlob(&buf, p->aRecord, p->nRecord, &rc);

  200865.         if( rc==SQLITE_OK && xOutput && buf.nBuf>=sessions_strm_chunk_size ){

  200866.           rc = xOutput(pOut, buf.aBuf, buf.nBuf);

  200867.           buf.nBuf = 0;

  200868.         }

  200869.       }

  200870.     }

  200871.   }

  200872. 

  200873.   if( rc==SQLITE_OK ){

  200874.     if( xOutput ){

  200875.       if( buf.nBuf>0 ) rc = xOutput(pOut, buf.aBuf, buf.nBuf);

  200876.     }else{

  200877.       *ppOut = buf.aBuf;

  200878.       *pnOut = buf.nBuf;

  200879.       buf.aBuf = 0;

  200880.     }

  200881.   }

  200882.   sqlite3_free(buf.aBuf);

  200883. 

  200884.   return rc;

  200885. }

  200886. 

  200887. /*

  200888. ** Allocate a new, empty, sqlite3_changegroup.

  200889. */

  200890. SQLITE_API int sqlite3changegroup_new(sqlite3_changegroup **pp){

  200891.   int rc = SQLITE_OK;             /* Return code */

  200892.   sqlite3_changegroup *p;         /* New object */

  200893.   p = (sqlite3_changegroup*)sqlite3_malloc(sizeof(sqlite3_changegroup));

  200894.   if( p==0 ){

  200895.     rc = SQLITE_NOMEM;

  200896.   }else{

  200897.     memset(p, 0, sizeof(sqlite3_changegroup));

  200898.   }

  200899.   *pp = p;

  200900.   return rc;

  200901. }

  200902. 

  200903. /*

  200904. ** Add the changeset currently stored in buffer pData, size nData bytes,

  200905. ** to changeset-group p.

  200906. */

  200907. SQLITE_API int sqlite3changegroup_add(sqlite3_changegroup *pGrp, int nData, void *pData){

  200908.   sqlite3_changeset_iter *pIter;  /* Iterator opened on pData/nData */

  200909.   int rc;                         /* Return code */

  200910. 

  200911.   rc = sqlite3changeset_start(&pIter, nData, pData);

  200912.   if( rc==SQLITE_OK ){

  200913.     rc = sessionChangesetToHash(pIter, pGrp, 0);

  200914.   }

  200915.   sqlite3changeset_finalize(pIter);

  200916.   return rc;

  200917. }

  200918. 

  200919. /*

  200920. ** Obtain a buffer containing a changeset representing the concatenation

  200921. ** of all changesets added to the group so far.

  200922. */

  200923. SQLITE_API int sqlite3changegroup_output(

  200924.     sqlite3_changegroup *pGrp,

  200925.     int *pnData,

  200926.     void **ppData

  200927. ){

  200928.   return sessionChangegroupOutput(pGrp, 0, 0, pnData, ppData);

  200929. }

  200930. 

  200931. /*

  200932. ** Streaming versions of changegroup_add().

  200933. */

  200934. SQLITE_API int sqlite3changegroup_add_strm(

  200935.   sqlite3_changegroup *pGrp,

  200936.   int (*xInput)(void *pIn, void *pData, int *pnData),

  200937.   void *pIn

  200938. ){

  200939.   sqlite3_changeset_iter *pIter;  /* Iterator opened on pData/nData */

  200940.   int rc;                         /* Return code */

  200941. 

  200942.   rc = sqlite3changeset_start_strm(&pIter, xInput, pIn);

  200943.   if( rc==SQLITE_OK ){

  200944.     rc = sessionChangesetToHash(pIter, pGrp, 0);

  200945.   }

  200946.   sqlite3changeset_finalize(pIter);

  200947.   return rc;

  200948. }

  200949. 

  200950. /*

  200951. ** Streaming versions of changegroup_output().

  200952. */

  200953. SQLITE_API int sqlite3changegroup_output_strm(

  200954.   sqlite3_changegroup *pGrp,

  200955.   int (*xOutput)(void *pOut, const void *pData, int nData), 

  200956.   void *pOut

  200957. ){

  200958.   return sessionChangegroupOutput(pGrp, xOutput, pOut, 0, 0);

  200959. }

  200960. 

  200961. /*

  200962. ** Delete a changegroup object.

  200963. */

  200964. SQLITE_API void sqlite3changegroup_delete(sqlite3_changegroup *pGrp){

  200965.   if( pGrp ){

  200966.     sessionDeleteTable(pGrp->pList);

  200967.     sqlite3_free(pGrp);

  200968.   }

  200969. }

  200970. 

  200971. /* 

  200972. ** Combine two changesets together.

  200973. */

  200974. SQLITE_API int sqlite3changeset_concat(

  200975.   int nLeft,                      /* Number of bytes in lhs input */

  200976.   void *pLeft,                    /* Lhs input changeset */

  200977.   int nRight                      /* Number of bytes in rhs input */,

  200978.   void *pRight,                   /* Rhs input changeset */

  200979.   int *pnOut,                     /* OUT: Number of bytes in output changeset */

  200980.   void **ppOut                    /* OUT: changeset (left <concat> right) */

  200981. ){

  200982.   sqlite3_changegroup *pGrp;

  200983.   int rc;

  200984. 

  200985.   rc = sqlite3changegroup_new(&pGrp);

  200986.   if( rc==SQLITE_OK ){

  200987.     rc = sqlite3changegroup_add(pGrp, nLeft, pLeft);

  200988.   }

  200989.   if( rc==SQLITE_OK ){

  200990.     rc = sqlite3changegroup_add(pGrp, nRight, pRight);

  200991.   }

  200992.   if( rc==SQLITE_OK ){

  200993.     rc = sqlite3changegroup_output(pGrp, pnOut, ppOut);

  200994.   }

  200995.   sqlite3changegroup_delete(pGrp);

  200996. 

  200997.   return rc;

  200998. }

  200999. 

  201000. /*

  201001. ** Streaming version of sqlite3changeset_concat().

  201002. */

  201003. SQLITE_API int sqlite3changeset_concat_strm(

  201004.   int (*xInputA)(void *pIn, void *pData, int *pnData),

  201005.   void *pInA,

  201006.   int (*xInputB)(void *pIn, void *pData, int *pnData),

  201007.   void *pInB,

  201008.   int (*xOutput)(void *pOut, const void *pData, int nData),

  201009.   void *pOut

  201010. ){

  201011.   sqlite3_changegroup *pGrp;

  201012.   int rc;

  201013. 

  201014.   rc = sqlite3changegroup_new(&pGrp);

  201015.   if( rc==SQLITE_OK ){

  201016.     rc = sqlite3changegroup_add_strm(pGrp, xInputA, pInA);

  201017.   }

  201018.   if( rc==SQLITE_OK ){

  201019.     rc = sqlite3changegroup_add_strm(pGrp, xInputB, pInB);

  201020.   }

  201021.   if( rc==SQLITE_OK ){

  201022.     rc = sqlite3changegroup_output_strm(pGrp, xOutput, pOut);

  201023.   }

  201024.   sqlite3changegroup_delete(pGrp);

  201025. 

  201026.   return rc;

  201027. }

  201028. 

  201029. /*

  201030. ** Changeset rebaser handle.

  201031. */

  201032. struct sqlite3_rebaser {

  201033.   sqlite3_changegroup grp;        /* Hash table */

  201034. };

  201035. 

  201036. /*

  201037. ** Buffers a1 and a2 must both contain a sessions module record nCol

  201038. ** fields in size. This function appends an nCol sessions module 

  201039. ** record to buffer pBuf that is a copy of a1, except that for

  201040. ** each field that is undefined in a1[], swap in the field from a2[].

  201041. */

  201042. static void sessionAppendRecordMerge(

  201043.   SessionBuffer *pBuf,            /* Buffer to append to */

  201044.   int nCol,                       /* Number of columns in each record */

  201045.   u8 *a1, int n1,                 /* Record 1 */

  201046.   u8 *a2, int n2,                 /* Record 2 */

  201047.   int *pRc                        /* IN/OUT: error code */

  201048. ){

  201049.   sessionBufferGrow(pBuf, n1+n2, pRc);

  201050.   if( *pRc==SQLITE_OK ){

  201051.     int i;

  201052.     u8 *pOut = &pBuf->aBuf[pBuf->nBuf];

  201053.     for(i=0; i<nCol; i++){

  201054.       int nn1 = sessionSerialLen(a1);

  201055.       int nn2 = sessionSerialLen(a2);

  201056.       if( *a1==0 || *a1==0xFF ){

  201057.         memcpy(pOut, a2, nn2);

  201058.         pOut += nn2;

  201059.       }else{

  201060.         memcpy(pOut, a1, nn1);

  201061.         pOut += nn1;

  201062.       }

  201063.       a1 += nn1;

  201064.       a2 += nn2;

  201065.     }

  201066. 

  201067.     pBuf->nBuf = pOut-pBuf->aBuf;

  201068.     assert( pBuf->nBuf<=pBuf->nAlloc );

  201069.   }

  201070. }

  201071. 

  201072. /*

  201073. ** This function is called when rebasing a local UPDATE change against one 

  201074. ** or more remote UPDATE changes. The aRec/nRec buffer contains the current

  201075. ** old.* and new.* records for the change. The rebase buffer (a single

  201076. ** record) is in aChange/nChange. The rebased change is appended to buffer

  201077. ** pBuf.

  201078. **

  201079. ** Rebasing the UPDATE involves: 

  201080. **

  201081. **   * Removing any changes to fields for which the corresponding field

  201082. **     in the rebase buffer is set to "replaced" (type 0xFF). If this

  201083. **     means the UPDATE change updates no fields, nothing is appended

  201084. **     to the output buffer.

  201085. **

  201086. **   * For each field modified by the local change for which the 

  201087. **     corresponding field in the rebase buffer is not "undefined" (0x00)

  201088. **     or "replaced" (0xFF), the old.* value is replaced by the value

  201089. **     in the rebase buffer.

  201090. */

  201091. static void sessionAppendPartialUpdate(

  201092.   SessionBuffer *pBuf,            /* Append record here */

  201093.   sqlite3_changeset_iter *pIter,  /* Iterator pointed at local change */

  201094.   u8 *aRec, int nRec,             /* Local change */

  201095.   u8 *aChange, int nChange,       /* Record to rebase against */

  201096.   int *pRc                        /* IN/OUT: Return Code */

  201097. ){

  201098.   sessionBufferGrow(pBuf, 2+nRec+nChange, pRc);

  201099.   if( *pRc==SQLITE_OK ){

  201100.     int bData = 0;

  201101.     u8 *pOut = &pBuf->aBuf[pBuf->nBuf];

  201102.     int i;

  201103.     u8 *a1 = aRec;

  201104.     u8 *a2 = aChange;

  201105. 

  201106.     *pOut++ = SQLITE_UPDATE;

  201107.     *pOut++ = pIter->bIndirect;

  201108.     for(i=0; i<pIter->nCol; i++){

  201109.       int n1 = sessionSerialLen(a1);

  201110.       int n2 = sessionSerialLen(a2);

  201111.       if( pIter->abPK[i] || a2[0]==0 ){

  201112.         if( !pIter->abPK[i] ) bData = 1;

  201113.         memcpy(pOut, a1, n1);

  201114.         pOut += n1;

  201115.       }else if( a2[0]!=0xFF ){

  201116.         bData = 1;

  201117.         memcpy(pOut, a2, n2);

  201118.         pOut += n2;

  201119.       }else{

  201120.         *pOut++ = '\0';

  201121.       }

  201122.       a1 += n1;

  201123.       a2 += n2;

  201124.     }

  201125.     if( bData ){

  201126.       a2 = aChange;

  201127.       for(i=0; i<pIter->nCol; i++){

  201128.         int n1 = sessionSerialLen(a1);

  201129.         int n2 = sessionSerialLen(a2);

  201130.         if( pIter->abPK[i] || a2[0]!=0xFF ){

  201131.           memcpy(pOut, a1, n1);

  201132.           pOut += n1;

  201133.         }else{

  201134.           *pOut++ = '\0';

  201135.         }

  201136.         a1 += n1;

  201137.         a2 += n2;

  201138.       }

  201139.       pBuf->nBuf = (pOut - pBuf->aBuf);

  201140.     }

  201141.   }

  201142. }

  201143. 

  201144. /*

  201145. ** pIter is configured to iterate through a changeset. This function rebases 

  201146. ** that changeset according to the current configuration of the rebaser 

  201147. ** object passed as the first argument. If no error occurs and argument xOutput

  201148. ** is not NULL, then the changeset is returned to the caller by invoking

  201149. ** xOutput zero or more times and SQLITE_OK returned. Or, if xOutput is NULL,

  201150. ** then (*ppOut) is set to point to a buffer containing the rebased changeset

  201151. ** before this function returns. In this case (*pnOut) is set to the size of

  201152. ** the buffer in bytes.  It is the responsibility of the caller to eventually

  201153. ** free the (*ppOut) buffer using sqlite3_free(). 

  201154. **

  201155. ** If an error occurs, an SQLite error code is returned. If ppOut and

  201156. ** pnOut are not NULL, then the two output parameters are set to 0 before

  201157. ** returning.

  201158. */

  201159. static int sessionRebase(

  201160.   sqlite3_rebaser *p,             /* Rebaser hash table */

  201161.   sqlite3_changeset_iter *pIter,  /* Input data */

  201162.   int (*xOutput)(void *pOut, const void *pData, int nData),

  201163.   void *pOut,                     /* Context for xOutput callback */

  201164.   int *pnOut,                     /* OUT: Number of bytes in output changeset */

  201165.   void **ppOut                    /* OUT: Inverse of pChangeset */

  201166. ){

  201167.   int rc = SQLITE_OK;

  201168.   u8 *aRec = 0;

  201169.   int nRec = 0;

  201170.   int bNew = 0;

  201171.   SessionTable *pTab = 0;

  201172.   SessionBuffer sOut = {0,0,0};

  201173. 

  201174.   while( SQLITE_ROW==sessionChangesetNext(pIter, &aRec, &nRec, &bNew) ){

  201175.     SessionChange *pChange = 0;

  201176.     int bDone = 0;

  201177. 

  201178.     if( bNew ){

  201179.       const char *zTab = pIter->zTab;

  201180.       for(pTab=p->grp.pList; pTab; pTab=pTab->pNext){

  201181.         if( 0==sqlite3_stricmp(pTab->zName, zTab) ) break;

  201182.       }

  201183.       bNew = 0;

  201184. 

  201185.       /* A patchset may not be rebased */

  201186.       if( pIter->bPatchset ){

  201187.         rc = SQLITE_ERROR;

  201188.       }

  201189. 

  201190.       /* Append a table header to the output for this new table */

  201191.       sessionAppendByte(&sOut, pIter->bPatchset ? 'P' : 'T', &rc);

  201192.       sessionAppendVarint(&sOut, pIter->nCol, &rc);

  201193.       sessionAppendBlob(&sOut, pIter->abPK, pIter->nCol, &rc);

  201194.       sessionAppendBlob(&sOut,(u8*)pIter->zTab,(int)strlen(pIter->zTab)+1,&rc);

  201195.     }

  201196. 

  201197.     if( pTab && rc==SQLITE_OK ){

  201198.       int iHash = sessionChangeHash(pTab, 0, aRec, pTab->nChange);

  201199. 

  201200.       for(pChange=pTab->apChange[iHash]; pChange; pChange=pChange->pNext){

  201201.         if( sessionChangeEqual(pTab, 0, aRec, 0, pChange->aRecord) ){

  201202.           break;

  201203.         }

  201204.       }

  201205.     }

  201206. 

  201207.     if( pChange ){

  201208.       assert( pChange->op==SQLITE_DELETE || pChange->op==SQLITE_INSERT );

  201209.       switch( pIter->op ){

  201210.         case SQLITE_INSERT:

  201211.           if( pChange->op==SQLITE_INSERT ){

  201212.             bDone = 1;

  201213.             if( pChange->bIndirect==0 ){

  201214.               sessionAppendByte(&sOut, SQLITE_UPDATE, &rc);

  201215.               sessionAppendByte(&sOut, pIter->bIndirect, &rc);

  201216.               sessionAppendBlob(&sOut, pChange->aRecord, pChange->nRecord, &rc);

  201217.               sessionAppendBlob(&sOut, aRec, nRec, &rc);

  201218.             }

  201219.           }

  201220.           break;

  201221. 

  201222.         case SQLITE_UPDATE:

  201223.           bDone = 1;

  201224.           if( pChange->op==SQLITE_DELETE ){

  201225.             if( pChange->bIndirect==0 ){

  201226.               u8 *pCsr = aRec;

  201227.               sessionSkipRecord(&pCsr, pIter->nCol);

  201228.               sessionAppendByte(&sOut, SQLITE_INSERT, &rc);

  201229.               sessionAppendByte(&sOut, pIter->bIndirect, &rc);

  201230.               sessionAppendRecordMerge(&sOut, pIter->nCol,

  201231.                   pCsr, nRec-(pCsr-aRec), 

  201232.                   pChange->aRecord, pChange->nRecord, &rc

  201233.               );

  201234.             }

  201235.           }else{

  201236.             sessionAppendPartialUpdate(&sOut, pIter,

  201237.                 aRec, nRec, pChange->aRecord, pChange->nRecord, &rc

  201238.             );

  201239.           }

  201240.           break;

  201241. 

  201242.         default:

  201243.           assert( pIter->op==SQLITE_DELETE );

  201244.           bDone = 1;

  201245.           if( pChange->op==SQLITE_INSERT ){

  201246.             sessionAppendByte(&sOut, SQLITE_DELETE, &rc);

  201247.             sessionAppendByte(&sOut, pIter->bIndirect, &rc);

  201248.             sessionAppendRecordMerge(&sOut, pIter->nCol,

  201249.                 pChange->aRecord, pChange->nRecord, aRec, nRec, &rc

  201250.             );

  201251.           }

  201252.           break;

  201253.       }

  201254.     }

  201255. 

  201256.     if( bDone==0 ){

  201257.       sessionAppendByte(&sOut, pIter->op, &rc);

  201258.       sessionAppendByte(&sOut, pIter->bIndirect, &rc);

  201259.       sessionAppendBlob(&sOut, aRec, nRec, &rc);

  201260.     }

  201261.     if( rc==SQLITE_OK && xOutput && sOut.nBuf>sessions_strm_chunk_size ){

  201262.       rc = xOutput(pOut, sOut.aBuf, sOut.nBuf);

  201263.       sOut.nBuf = 0;

  201264.     }

  201265.     if( rc ) break;

  201266.   }

  201267. 

  201268.   if( rc!=SQLITE_OK ){

  201269.     sqlite3_free(sOut.aBuf);

  201270.     memset(&sOut, 0, sizeof(sOut));

  201271.   }

  201272. 

  201273.   if( rc==SQLITE_OK ){

  201274.     if( xOutput ){

  201275.       if( sOut.nBuf>0 ){

  201276.         rc = xOutput(pOut, sOut.aBuf, sOut.nBuf);

  201277.       }

  201278.     }else{

  201279.       *ppOut = (void*)sOut.aBuf;

  201280.       *pnOut = sOut.nBuf;

  201281.       sOut.aBuf = 0;

  201282.     }

  201283.   }

  201284.   sqlite3_free(sOut.aBuf);

  201285.   return rc;

  201286. }

  201287. 

  201288. /* 

  201289. ** Create a new rebaser object.

  201290. */

  201291. SQLITE_API int sqlite3rebaser_create(sqlite3_rebaser **ppNew){

  201292.   int rc = SQLITE_OK;

  201293.   sqlite3_rebaser *pNew;

  201294. 

  201295.   pNew = sqlite3_malloc(sizeof(sqlite3_rebaser));

  201296.   if( pNew==0 ){

  201297.     rc = SQLITE_NOMEM;

  201298.   }else{

  201299.     memset(pNew, 0, sizeof(sqlite3_rebaser));

  201300.   }

  201301.   *ppNew = pNew;

  201302.   return rc;

  201303. }

  201304. 

  201305. /* 

  201306. ** Call this one or more times to configure a rebaser.

  201307. */

  201308. SQLITE_API int sqlite3rebaser_configure(

  201309.   sqlite3_rebaser *p, 

  201310.   int nRebase, const void *pRebase

  201311. ){

  201312.   sqlite3_changeset_iter *pIter = 0;   /* Iterator opened on pData/nData */

  201313.   int rc;                              /* Return code */

  201314.   rc = sqlite3changeset_start(&pIter, nRebase, (void*)pRebase);

  201315.   if( rc==SQLITE_OK ){

  201316.     rc = sessionChangesetToHash(pIter, &p->grp, 1);

  201317.   }

  201318.   sqlite3changeset_finalize(pIter);

  201319.   return rc;

  201320. }

  201321. 

  201322. /* 

  201323. ** Rebase a changeset according to current rebaser configuration 

  201324. */

  201325. SQLITE_API int sqlite3rebaser_rebase(

  201326.   sqlite3_rebaser *p,

  201327.   int nIn, const void *pIn, 

  201328.   int *pnOut, void **ppOut 

  201329. ){

  201330.   sqlite3_changeset_iter *pIter = 0;   /* Iterator to skip through input */  

  201331.   int rc = sqlite3changeset_start(&pIter, nIn, (void*)pIn);

  201332. 

  201333.   if( rc==SQLITE_OK ){

  201334.     rc = sessionRebase(p, pIter, 0, 0, pnOut, ppOut);

  201335.     sqlite3changeset_finalize(pIter);

  201336.   }

  201337. 

  201338.   return rc;

  201339. }

  201340. 

  201341. /* 

  201342. ** Rebase a changeset according to current rebaser configuration 

  201343. */

  201344. SQLITE_API int sqlite3rebaser_rebase_strm(

  201345.   sqlite3_rebaser *p,

  201346.   int (*xInput)(void *pIn, void *pData, int *pnData),

  201347.   void *pIn,

  201348.   int (*xOutput)(void *pOut, const void *pData, int nData),

  201349.   void *pOut

  201350. ){

  201351.   sqlite3_changeset_iter *pIter = 0;   /* Iterator to skip through input */  

  201352.   int rc = sqlite3changeset_start_strm(&pIter, xInput, pIn);

  201353. 

  201354.   if( rc==SQLITE_OK ){

  201355.     rc = sessionRebase(p, pIter, xOutput, pOut, 0, 0);

  201356.     sqlite3changeset_finalize(pIter);

  201357.   }

  201358. 

  201359.   return rc;

  201360. }

  201361. 

  201362. /* 

  201363. ** Destroy a rebaser object 

  201364. */

  201365. SQLITE_API void sqlite3rebaser_delete(sqlite3_rebaser *p){

  201366.   if( p ){

  201367.     sessionDeleteTable(p->grp.pList);

  201368.     sqlite3_free(p);

  201369.   }

  201370. }

  201371. 

  201372. /* 

  201373. ** Global configuration

  201374. */

  201375. SQLITE_API int sqlite3session_config(int op, void *pArg){

  201376.   int rc = SQLITE_OK;

  201377.   switch( op ){

  201378.     case SQLITE_SESSION_CONFIG_STRMSIZE: {

  201379.       int *pInt = (int*)pArg;

  201380.       if( *pInt>0 ){

  201381.         sessions_strm_chunk_size = *pInt;

  201382.       }

  201383.       *pInt = sessions_strm_chunk_size;

  201384.       break;

  201385.     }

  201386.     default:

  201387.       rc = SQLITE_MISUSE;

  201388.       break;

  201389.   }

  201390.   return rc;

  201391. }

  201392. 

  201393. #endif /* SQLITE_ENABLE_SESSION && SQLITE_ENABLE_PREUPDATE_HOOK */

  201394. 

  201395. /************** End of sqlite3session.c **************************************/

  201396. /************** Begin file fts5.c ********************************************/

  201397. 

  201398. 

  201399. #if !defined(SQLITE_CORE) || defined(SQLITE_ENABLE_FTS5) 

  201400. 

  201401. #if !defined(NDEBUG) && !defined(SQLITE_DEBUG) 

  201402. # define NDEBUG 1

  201403. #endif

  201404. #if defined(NDEBUG) && defined(SQLITE_DEBUG)

  201405. # undef NDEBUG

  201406. #endif

  201407. 

  201408. /*

  201409. ** 2014 May 31

  201410. **

  201411. ** The author disclaims copyright to this source code.  In place of

  201412. ** a legal notice, here is a blessing:

  201413. **

  201414. **    May you do good and not evil.

  201415. **    May you find forgiveness for yourself and forgive others.

  201416. **    May you share freely, never taking more than you give.

  201417. **

  201418. ******************************************************************************

  201419. **

  201420. ** Interfaces to extend FTS5. Using the interfaces defined in this file, 

  201421. ** FTS5 may be extended with:

  201422. **

  201423. **     * custom tokenizers, and

  201424. **     * custom auxiliary functions.

  201425. */

  201426. 

  201427. 

  201428. #ifndef _FTS5_H

  201429. #define _FTS5_H

  201430. 

  201431. /* #include "sqlite3.h" */

  201432. 

  201433. #if 0

  201434. extern "C" {

  201435. #endif

  201436. 

  201437. /*************************************************************************

  201438. ** CUSTOM AUXILIARY FUNCTIONS

  201439. **

  201440. ** Virtual table implementations may overload SQL functions by implementing

  201441. ** the sqlite3_module.xFindFunction() method.

  201442. */

  201443. 

  201444. typedef struct Fts5ExtensionApi Fts5ExtensionApi;

  201445. typedef struct Fts5Context Fts5Context;

  201446. typedef struct Fts5PhraseIter Fts5PhraseIter;

  201447. 

  201448. typedef void (*fts5_extension_function)(

  201449.   const Fts5ExtensionApi *pApi,   /* API offered by current FTS version */

  201450.   Fts5Context *pFts,              /* First arg to pass to pApi functions */

  201451.   sqlite3_context *pCtx,          /* Context for returning result/error */

  201452.   int nVal,                       /* Number of values in apVal[] array */

  201453.   sqlite3_value **apVal           /* Array of trailing arguments */

  201454. );

  201455. 

  201456. struct Fts5PhraseIter {

  201457.   const unsigned char *a;

  201458.   const unsigned char *b;

  201459. };

  201460. 

  201461. /*

  201462. ** EXTENSION API FUNCTIONS

  201463. **

  201464. ** xUserData(pFts):

  201465. **   Return a copy of the context pointer the extension function was 

  201466. **   registered with.

  201467. **

  201468. ** xColumnTotalSize(pFts, iCol, pnToken):

  201469. **   If parameter iCol is less than zero, set output variable *pnToken

  201470. **   to the total number of tokens in the FTS5 table. Or, if iCol is

  201471. **   non-negative but less than the number of columns in the table, return

  201472. **   the total number of tokens in column iCol, considering all rows in 

  201473. **   the FTS5 table.

  201474. **

  201475. **   If parameter iCol is greater than or equal to the number of columns

  201476. **   in the table, SQLITE_RANGE is returned. Or, if an error occurs (e.g.

  201477. **   an OOM condition or IO error), an appropriate SQLite error code is 

  201478. **   returned.

  201479. **

  201480. ** xColumnCount(pFts):

  201481. **   Return the number of columns in the table.

  201482. **

  201483. ** xColumnSize(pFts, iCol, pnToken):

  201484. **   If parameter iCol is less than zero, set output variable *pnToken

  201485. **   to the total number of tokens in the current row. Or, if iCol is

  201486. **   non-negative but less than the number of columns in the table, set

  201487. **   *pnToken to the number of tokens in column iCol of the current row.

  201488. **

  201489. **   If parameter iCol is greater than or equal to the number of columns

  201490. **   in the table, SQLITE_RANGE is returned. Or, if an error occurs (e.g.

  201491. **   an OOM condition or IO error), an appropriate SQLite error code is 

  201492. **   returned.

  201493. **

  201494. **   This function may be quite inefficient if used with an FTS5 table

  201495. **   created with the "columnsize=0" option.

  201496. **

  201497. ** xColumnText:

  201498. **   This function attempts to retrieve the text of column iCol of the

  201499. **   current document. If successful, (*pz) is set to point to a buffer

  201500. **   containing the text in utf-8 encoding, (*pn) is set to the size in bytes

  201501. **   (not characters) of the buffer and SQLITE_OK is returned. Otherwise,

  201502. **   if an error occurs, an SQLite error code is returned and the final values

  201503. **   of (*pz) and (*pn) are undefined.

  201504. **

  201505. ** xPhraseCount:

  201506. **   Returns the number of phrases in the current query expression.

  201507. **

  201508. ** xPhraseSize:

  201509. **   Returns the number of tokens in phrase iPhrase of the query. Phrases

  201510. **   are numbered starting from zero.

  201511. **

  201512. ** xInstCount:

  201513. **   Set *pnInst to the total number of occurrences of all phrases within

  201514. **   the query within the current row. Return SQLITE_OK if successful, or

  201515. **   an error code (i.e. SQLITE_NOMEM) if an error occurs.

  201516. **

  201517. **   This API can be quite slow if used with an FTS5 table created with the

  201518. **   "detail=none" or "detail=column" option. If the FTS5 table is created 

  201519. **   with either "detail=none" or "detail=column" and "content=" option 

  201520. **   (i.e. if it is a contentless table), then this API always returns 0.

  201521. **

  201522. ** xInst:

  201523. **   Query for the details of phrase match iIdx within the current row.

  201524. **   Phrase matches are numbered starting from zero, so the iIdx argument

  201525. **   should be greater than or equal to zero and smaller than the value

  201526. **   output by xInstCount().

  201527. **

  201528. **   Usually, output parameter *piPhrase is set to the phrase number, *piCol

  201529. **   to the column in which it occurs and *piOff the token offset of the

  201530. **   first token of the phrase. Returns SQLITE_OK if successful, or an error

  201531. **   code (i.e. SQLITE_NOMEM) if an error occurs.

  201532. **

  201533. **   This API can be quite slow if used with an FTS5 table created with the

  201534. **   "detail=none" or "detail=column" option. 

  201535. **

  201536. ** xRowid:

  201537. **   Returns the rowid of the current row.

  201538. **

  201539. ** xTokenize:

  201540. **   Tokenize text using the tokenizer belonging to the FTS5 table.

  201541. **

  201542. ** xQueryPhrase(pFts5, iPhrase, pUserData, xCallback):

  201543. **   This API function is used to query the FTS table for phrase iPhrase

  201544. **   of the current query. Specifically, a query equivalent to:

  201545. **

  201546. **       ... FROM ftstable WHERE ftstable MATCH $p ORDER BY rowid

  201547. **

  201548. **   with $p set to a phrase equivalent to the phrase iPhrase of the

  201549. **   current query is executed. Any column filter that applies to

  201550. **   phrase iPhrase of the current query is included in $p. For each 

  201551. **   row visited, the callback function passed as the fourth argument 

  201552. **   is invoked. The context and API objects passed to the callback 

  201553. **   function may be used to access the properties of each matched row.

  201554. **   Invoking Api.xUserData() returns a copy of the pointer passed as 

  201555. **   the third argument to pUserData.

  201556. **

  201557. **   If the callback function returns any value other than SQLITE_OK, the

  201558. **   query is abandoned and the xQueryPhrase function returns immediately.

  201559. **   If the returned value is SQLITE_DONE, xQueryPhrase returns SQLITE_OK.

  201560. **   Otherwise, the error code is propagated upwards.

  201561. **

  201562. **   If the query runs to completion without incident, SQLITE_OK is returned.

  201563. **   Or, if some error occurs before the query completes or is aborted by

  201564. **   the callback, an SQLite error code is returned.

  201565. **

  201566. **

  201567. ** xSetAuxdata(pFts5, pAux, xDelete)

  201568. **

  201569. **   Save the pointer passed as the second argument as the extension functions 

  201570. **   "auxiliary data". The pointer may then be retrieved by the current or any

  201571. **   future invocation of the same fts5 extension function made as part of

  201572. **   the same MATCH query using the xGetAuxdata() API.

  201573. **

  201574. **   Each extension function is allocated a single auxiliary data slot for

  201575. **   each FTS query (MATCH expression). If the extension function is invoked 

  201576. **   more than once for a single FTS query, then all invocations share a 

  201577. **   single auxiliary data context.

  201578. **

  201579. **   If there is already an auxiliary data pointer when this function is

  201580. **   invoked, then it is replaced by the new pointer. If an xDelete callback

  201581. **   was specified along with the original pointer, it is invoked at this

  201582. **   point.

  201583. **

  201584. **   The xDelete callback, if one is specified, is also invoked on the

  201585. **   auxiliary data pointer after the FTS5 query has finished.

  201586. **

  201587. **   If an error (e.g. an OOM condition) occurs within this function,

  201588. **   the auxiliary data is set to NULL and an error code returned. If the

  201589. **   xDelete parameter was not NULL, it is invoked on the auxiliary data

  201590. **   pointer before returning.

  201591. **

  201592. **

  201593. ** xGetAuxdata(pFts5, bClear)

  201594. **

  201595. **   Returns the current auxiliary data pointer for the fts5 extension 

  201596. **   function. See the xSetAuxdata() method for details.

  201597. **

  201598. **   If the bClear argument is non-zero, then the auxiliary data is cleared

  201599. **   (set to NULL) before this function returns. In this case the xDelete,

  201600. **   if any, is not invoked.

  201601. **

  201602. **

  201603. ** xRowCount(pFts5, pnRow)

  201604. **

  201605. **   This function is used to retrieve the total number of rows in the table.

  201606. **   In other words, the same value that would be returned by:

  201607. **

  201608. **        SELECT count(*) FROM ftstable;

  201609. **

  201610. ** xPhraseFirst()

  201611. **   This function is used, along with type Fts5PhraseIter and the xPhraseNext

  201612. **   method, to iterate through all instances of a single query phrase within

  201613. **   the current row. This is the same information as is accessible via the

  201614. **   xInstCount/xInst APIs. While the xInstCount/xInst APIs are more convenient

  201615. **   to use, this API may be faster under some circumstances. To iterate 

  201616. **   through instances of phrase iPhrase, use the following code:

  201617. **

  201618. **       Fts5PhraseIter iter;

  201619. **       int iCol, iOff;

  201620. **       for(pApi->xPhraseFirst(pFts, iPhrase, &iter, &iCol, &iOff);

  201621. **           iCol>=0;

  201622. **           pApi->xPhraseNext(pFts, &iter, &iCol, &iOff)

  201623. **       ){

  201624. **         // An instance of phrase iPhrase at offset iOff of column iCol

  201625. **       }

  201626. **

  201627. **   The Fts5PhraseIter structure is defined above. Applications should not

  201628. **   modify this structure directly - it should only be used as shown above

  201629. **   with the xPhraseFirst() and xPhraseNext() API methods (and by

  201630. **   xPhraseFirstColumn() and xPhraseNextColumn() as illustrated below).

  201631. **

  201632. **   This API can be quite slow if used with an FTS5 table created with the

  201633. **   "detail=none" or "detail=column" option. If the FTS5 table is created 

  201634. **   with either "detail=none" or "detail=column" and "content=" option 

  201635. **   (i.e. if it is a contentless table), then this API always iterates

  201636. **   through an empty set (all calls to xPhraseFirst() set iCol to -1).

  201637. **

  201638. ** xPhraseNext()

  201639. **   See xPhraseFirst above.

  201640. **

  201641. ** xPhraseFirstColumn()

  201642. **   This function and xPhraseNextColumn() are similar to the xPhraseFirst()

  201643. **   and xPhraseNext() APIs described above. The difference is that instead

  201644. **   of iterating through all instances of a phrase in the current row, these

  201645. **   APIs are used to iterate through the set of columns in the current row

  201646. **   that contain one or more instances of a specified phrase. For example:

  201647. **

  201648. **       Fts5PhraseIter iter;

  201649. **       int iCol;

  201650. **       for(pApi->xPhraseFirstColumn(pFts, iPhrase, &iter, &iCol);

  201651. **           iCol>=0;

  201652. **           pApi->xPhraseNextColumn(pFts, &iter, &iCol)

  201653. **       ){

  201654. **         // Column iCol contains at least one instance of phrase iPhrase

  201655. **       }

  201656. **

  201657. **   This API can be quite slow if used with an FTS5 table created with the

  201658. **   "detail=none" option. If the FTS5 table is created with either 

  201659. **   "detail=none" "content=" option (i.e. if it is a contentless table), 

  201660. **   then this API always iterates through an empty set (all calls to 

  201661. **   xPhraseFirstColumn() set iCol to -1).

  201662. **

  201663. **   The information accessed using this API and its companion

  201664. **   xPhraseFirstColumn() may also be obtained using xPhraseFirst/xPhraseNext

  201665. **   (or xInst/xInstCount). The chief advantage of this API is that it is

  201666. **   significantly more efficient than those alternatives when used with

  201667. **   "detail=column" tables.  

  201668. **

  201669. ** xPhraseNextColumn()

  201670. **   See xPhraseFirstColumn above.

  201671. */

  201672. struct Fts5ExtensionApi {

  201673.   int iVersion;                   /* Currently always set to 3 */

  201674. 

  201675.   void *(*xUserData)(Fts5Context*);

  201676. 

  201677.   int (*xColumnCount)(Fts5Context*);

  201678.   int (*xRowCount)(Fts5Context*, sqlite3_int64 *pnRow);

  201679.   int (*xColumnTotalSize)(Fts5Context*, int iCol, sqlite3_int64 *pnToken);

  201680. 

  201681.   int (*xTokenize)(Fts5Context*, 

  201682.     const char *pText, int nText, /* Text to tokenize */

  201683.     void *pCtx,                   /* Context passed to xToken() */

  201684.     int (*xToken)(void*, int, const char*, int, int, int)       /* Callback */

  201685.   );

  201686. 

  201687.   int (*xPhraseCount)(Fts5Context*);

  201688.   int (*xPhraseSize)(Fts5Context*, int iPhrase);

  201689. 

  201690.   int (*xInstCount)(Fts5Context*, int *pnInst);

  201691.   int (*xInst)(Fts5Context*, int iIdx, int *piPhrase, int *piCol, int *piOff);

  201692. 

  201693.   sqlite3_int64 (*xRowid)(Fts5Context*);

  201694.   int (*xColumnText)(Fts5Context*, int iCol, const char **pz, int *pn);

  201695.   int (*xColumnSize)(Fts5Context*, int iCol, int *pnToken);

  201696. 

  201697.   int (*xQueryPhrase)(Fts5Context*, int iPhrase, void *pUserData,

  201698.     int(*)(const Fts5ExtensionApi*,Fts5Context*,void*)

  201699.   );

  201700.   int (*xSetAuxdata)(Fts5Context*, void *pAux, void(*xDelete)(void*));

  201701.   void *(*xGetAuxdata)(Fts5Context*, int bClear);

  201702. 

  201703.   int (*xPhraseFirst)(Fts5Context*, int iPhrase, Fts5PhraseIter*, int*, int*);

  201704.   void (*xPhraseNext)(Fts5Context*, Fts5PhraseIter*, int *piCol, int *piOff);

  201705. 

  201706.   int (*xPhraseFirstColumn)(Fts5Context*, int iPhrase, Fts5PhraseIter*, int*);

  201707.   void (*xPhraseNextColumn)(Fts5Context*, Fts5PhraseIter*, int *piCol);

  201708. };

  201709. 

  201710. /* 

  201711. ** CUSTOM AUXILIARY FUNCTIONS

  201712. *************************************************************************/

  201713. 

  201714. /*************************************************************************

  201715. ** CUSTOM TOKENIZERS

  201716. **

  201717. ** Applications may also register custom tokenizer types. A tokenizer 

  201718. ** is registered by providing fts5 with a populated instance of the 

  201719. ** following structure. All structure methods must be defined, setting

  201720. ** any member of the fts5_tokenizer struct to NULL leads to undefined

  201721. ** behaviour. The structure methods are expected to function as follows:

  201722. **

  201723. ** xCreate:

  201724. **   This function is used to allocate and initialize a tokenizer instance.

  201725. **   A tokenizer instance is required to actually tokenize text.

  201726. **

  201727. **   The first argument passed to this function is a copy of the (void*)

  201728. **   pointer provided by the application when the fts5_tokenizer object

  201729. **   was registered with FTS5 (the third argument to xCreateTokenizer()). 

  201730. **   The second and third arguments are an array of nul-terminated strings

  201731. **   containing the tokenizer arguments, if any, specified following the

  201732. **   tokenizer name as part of the CREATE VIRTUAL TABLE statement used

  201733. **   to create the FTS5 table.

  201734. **

  201735. **   The final argument is an output variable. If successful, (*ppOut) 

  201736. **   should be set to point to the new tokenizer handle and SQLITE_OK

  201737. **   returned. If an error occurs, some value other than SQLITE_OK should

  201738. **   be returned. In this case, fts5 assumes that the final value of *ppOut 

  201739. **   is undefined.

  201740. **

  201741. ** xDelete:

  201742. **   This function is invoked to delete a tokenizer handle previously

  201743. **   allocated using xCreate(). Fts5 guarantees that this function will

  201744. **   be invoked exactly once for each successful call to xCreate().

  201745. **

  201746. ** xTokenize:

  201747. **   This function is expected to tokenize the nText byte string indicated 

  201748. **   by argument pText. pText may or may not be nul-terminated. The first

  201749. **   argument passed to this function is a pointer to an Fts5Tokenizer object

  201750. **   returned by an earlier call to xCreate().

  201751. **

  201752. **   The second argument indicates the reason that FTS5 is requesting

  201753. **   tokenization of the supplied text. This is always one of the following

  201754. **   four values:

  201755. **

  201756. **   <ul><li> <b>FTS5_TOKENIZE_DOCUMENT</b> - A document is being inserted into

  201757. **            or removed from the FTS table. The tokenizer is being invoked to

  201758. **            determine the set of tokens to add to (or delete from) the

  201759. **            FTS index.

  201760. **

  201761. **       <li> <b>FTS5_TOKENIZE_QUERY</b> - A MATCH query is being executed 

  201762. **            against the FTS index. The tokenizer is being called to tokenize 

  201763. **            a bareword or quoted string specified as part of the query.

  201764. **

  201765. **       <li> <b>(FTS5_TOKENIZE_QUERY | FTS5_TOKENIZE_PREFIX)</b> - Same as

  201766. **            FTS5_TOKENIZE_QUERY, except that the bareword or quoted string is

  201767. **            followed by a "*" character, indicating that the last token

  201768. **            returned by the tokenizer will be treated as a token prefix.

  201769. **

  201770. **       <li> <b>FTS5_TOKENIZE_AUX</b> - The tokenizer is being invoked to 

  201771. **            satisfy an fts5_api.xTokenize() request made by an auxiliary

  201772. **            function. Or an fts5_api.xColumnSize() request made by the same

  201773. **            on a columnsize=0 database.  

  201774. **   </ul>

  201775. **

  201776. **   For each token in the input string, the supplied callback xToken() must

  201777. **   be invoked. The first argument to it should be a copy of the pointer

  201778. **   passed as the second argument to xTokenize(). The third and fourth

  201779. **   arguments are a pointer to a buffer containing the token text, and the

  201780. **   size of the token in bytes. The 4th and 5th arguments are the byte offsets

  201781. **   of the first byte of and first byte immediately following the text from

  201782. **   which the token is derived within the input.

  201783. **

  201784. **   The second argument passed to the xToken() callback ("tflags") should

  201785. **   normally be set to 0. The exception is if the tokenizer supports 

  201786. **   synonyms. In this case see the discussion below for details.

  201787. **

  201788. **   FTS5 assumes the xToken() callback is invoked for each token in the 

  201789. **   order that they occur within the input text.

  201790. **

  201791. **   If an xToken() callback returns any value other than SQLITE_OK, then

  201792. **   the tokenization should be abandoned and the xTokenize() method should

  201793. **   immediately return a copy of the xToken() return value. Or, if the

  201794. **   input buffer is exhausted, xTokenize() should return SQLITE_OK. Finally,

  201795. **   if an error occurs with the xTokenize() implementation itself, it

  201796. **   may abandon the tokenization and return any error code other than

  201797. **   SQLITE_OK or SQLITE_DONE.

  201798. **

  201799. ** SYNONYM SUPPORT

  201800. **

  201801. **   Custom tokenizers may also support synonyms. Consider a case in which a

  201802. **   user wishes to query for a phrase such as "first place". Using the 

  201803. **   built-in tokenizers, the FTS5 query 'first + place' will match instances

  201804. **   of "first place" within the document set, but not alternative forms

  201805. **   such as "1st place". In some applications, it would be better to match

  201806. **   all instances of "first place" or "1st place" regardless of which form

  201807. **   the user specified in the MATCH query text.

  201808. **

  201809. **   There are several ways to approach this in FTS5:

  201810. **

  201811. **   <ol><li> By mapping all synonyms to a single token. In this case, the 

  201812. **            In the above example, this means that the tokenizer returns the

  201813. **            same token for inputs "first" and "1st". Say that token is in

  201814. **            fact "first", so that when the user inserts the document "I won

  201815. **            1st place" entries are added to the index for tokens "i", "won",

  201816. **            "first" and "place". If the user then queries for '1st + place',

  201817. **            the tokenizer substitutes "first" for "1st" and the query works

  201818. **            as expected.

  201819. **

  201820. **       <li> By querying the index for all synonyms of each query term

  201821. **            separately. In this case, when tokenizing query text, the

  201822. **            tokenizer may provide multiple synonyms for a single term 

  201823. **            within the document. FTS5 then queries the index for each 

  201824. **            synonym individually. For example, faced with the query:

  201825. **

  201826. **   <codeblock>

  201827. **     ... MATCH 'first place'</codeblock>

  201828. **

  201829. **            the tokenizer offers both "1st" and "first" as synonyms for the

  201830. **            first token in the MATCH query and FTS5 effectively runs a query 

  201831. **            similar to:

  201832. **

  201833. **   <codeblock>

  201834. **     ... MATCH '(first OR 1st) place'</codeblock>

  201835. **

  201836. **            except that, for the purposes of auxiliary functions, the query

  201837. **            still appears to contain just two phrases - "(first OR 1st)" 

  201838. **            being treated as a single phrase.

  201839. **

  201840. **       <li> By adding multiple synonyms for a single term to the FTS index.

  201841. **            Using this method, when tokenizing document text, the tokenizer

  201842. **            provides multiple synonyms for each token. So that when a 

  201843. **            document such as "I won first place" is tokenized, entries are

  201844. **            added to the FTS index for "i", "won", "first", "1st" and

  201845. **            "place".

  201846. **

  201847. **            This way, even if the tokenizer does not provide synonyms

  201848. **            when tokenizing query text (it should not - to do so would be

  201849. **            inefficient), it doesn't matter if the user queries for 

  201850. **            'first + place' or '1st + place', as there are entries in the

  201851. **            FTS index corresponding to both forms of the first token.

  201852. **   </ol>

  201853. **

  201854. **   Whether it is parsing document or query text, any call to xToken that

  201855. **   specifies a <i>tflags</i> argument with the FTS5_TOKEN_COLOCATED bit

  201856. **   is considered to supply a synonym for the previous token. For example,

  201857. **   when parsing the document "I won first place", a tokenizer that supports

  201858. **   synonyms would call xToken() 5 times, as follows:

  201859. **

  201860. **   <codeblock>

  201861. **       xToken(pCtx, 0, "i",                      1,  0,  1);

  201862. **       xToken(pCtx, 0, "won",                    3,  2,  5);

  201863. **       xToken(pCtx, 0, "first",                  5,  6, 11);

  201864. **       xToken(pCtx, FTS5_TOKEN_COLOCATED, "1st", 3,  6, 11);

  201865. **       xToken(pCtx, 0, "place",                  5, 12, 17);

  201866. **</codeblock>

  201867. **

  201868. **   It is an error to specify the FTS5_TOKEN_COLOCATED flag the first time

  201869. **   xToken() is called. Multiple synonyms may be specified for a single token

  201870. **   by making multiple calls to xToken(FTS5_TOKEN_COLOCATED) in sequence. 

  201871. **   There is no limit to the number of synonyms that may be provided for a

  201872. **   single token.

  201873. **

  201874. **   In many cases, method (1) above is the best approach. It does not add 

  201875. **   extra data to the FTS index or require FTS5 to query for multiple terms,

  201876. **   so it is efficient in terms of disk space and query speed. However, it

  201877. **   does not support prefix queries very well. If, as suggested above, the

  201878. **   token "first" is substituted for "1st" by the tokenizer, then the query:

  201879. **

  201880. **   <codeblock>

  201881. **     ... MATCH '1s*'</codeblock>

  201882. **

  201883. **   will not match documents that contain the token "1st" (as the tokenizer

  201884. **   will probably not map "1s" to any prefix of "first").

  201885. **

  201886. **   For full prefix support, method (3) may be preferred. In this case, 

  201887. **   because the index contains entries for both "first" and "1st", prefix

  201888. **   queries such as 'fi*' or '1s*' will match correctly. However, because

  201889. **   extra entries are added to the FTS index, this method uses more space

  201890. **   within the database.

  201891. **

  201892. **   Method (2) offers a midpoint between (1) and (3). Using this method,

  201893. **   a query such as '1s*' will match documents that contain the literal 

  201894. **   token "1st", but not "first" (assuming the tokenizer is not able to

  201895. **   provide synonyms for prefixes). However, a non-prefix query like '1st'

  201896. **   will match against "1st" and "first". This method does not require

  201897. **   extra disk space, as no extra entries are added to the FTS index. 

  201898. **   On the other hand, it may require more CPU cycles to run MATCH queries,

  201899. **   as separate queries of the FTS index are required for each synonym.

  201900. **

  201901. **   When using methods (2) or (3), it is important that the tokenizer only

  201902. **   provide synonyms when tokenizing document text (method (2)) or query

  201903. **   text (method (3)), not both. Doing so will not cause any errors, but is

  201904. **   inefficient.

  201905. */

  201906. typedef struct Fts5Tokenizer Fts5Tokenizer;

  201907. typedef struct fts5_tokenizer fts5_tokenizer;

  201908. struct fts5_tokenizer {

  201909.   int (*xCreate)(void*, const char **azArg, int nArg, Fts5Tokenizer **ppOut);

  201910.   void (*xDelete)(Fts5Tokenizer*);

  201911.   int (*xTokenize)(Fts5Tokenizer*, 

  201912.       void *pCtx,

  201913.       int flags,            /* Mask of FTS5_TOKENIZE_* flags */

  201914.       const char *pText, int nText, 

  201915.       int (*xToken)(

  201916.         void *pCtx,         /* Copy of 2nd argument to xTokenize() */

  201917.         int tflags,         /* Mask of FTS5_TOKEN_* flags */

  201918.         const char *pToken, /* Pointer to buffer containing token */

  201919.         int nToken,         /* Size of token in bytes */

  201920.         int iStart,         /* Byte offset of token within input text */

  201921.         int iEnd            /* Byte offset of end of token within input text */

  201922.       )

  201923.   );

  201924. };

  201925. 

  201926. /* Flags that may be passed as the third argument to xTokenize() */

  201927. #define FTS5_TOKENIZE_QUERY     0x0001

  201928. #define FTS5_TOKENIZE_PREFIX    0x0002

  201929. #define FTS5_TOKENIZE_DOCUMENT  0x0004

  201930. #define FTS5_TOKENIZE_AUX       0x0008

  201931. 

  201932. /* Flags that may be passed by the tokenizer implementation back to FTS5

  201933. ** as the third argument to the supplied xToken callback. */

  201934. #define FTS5_TOKEN_COLOCATED    0x0001      /* Same position as prev. token */

  201935. 

  201936. /*

  201937. ** END OF CUSTOM TOKENIZERS

  201938. *************************************************************************/

  201939. 

  201940. /*************************************************************************

  201941. ** FTS5 EXTENSION REGISTRATION API

  201942. */

  201943. typedef struct fts5_api fts5_api;

  201944. struct fts5_api {

  201945.   int iVersion;                   /* Currently always set to 2 */

  201946. 

  201947.   /* Create a new tokenizer */

  201948.   int (*xCreateTokenizer)(

  201949.     fts5_api *pApi,

  201950.     const char *zName,

  201951.     void *pContext,

  201952.     fts5_tokenizer *pTokenizer,

  201953.     void (*xDestroy)(void*)

  201954.   );

  201955. 

  201956.   /* Find an existing tokenizer */

  201957.   int (*xFindTokenizer)(

  201958.     fts5_api *pApi,

  201959.     const char *zName,

  201960.     void **ppContext,

  201961.     fts5_tokenizer *pTokenizer

  201962.   );

  201963. 

  201964.   /* Create a new auxiliary function */

  201965.   int (*xCreateFunction)(

  201966.     fts5_api *pApi,

  201967.     const char *zName,

  201968.     void *pContext,

  201969.     fts5_extension_function xFunction,

  201970.     void (*xDestroy)(void*)

  201971.   );

  201972. };

  201973. 

  201974. /*

  201975. ** END OF REGISTRATION API

  201976. *************************************************************************/

  201977. 

  201978. #if 0

  201979. }  /* end of the 'extern "C"' block */

  201980. #endif

  201981. 

  201982. #endif /* _FTS5_H */

  201983. 

  201984. /*

  201985. ** 2014 May 31

  201986. **

  201987. ** The author disclaims copyright to this source code.  In place of

  201988. ** a legal notice, here is a blessing:

  201989. **

  201990. **    May you do good and not evil.

  201991. **    May you find forgiveness for yourself and forgive others.

  201992. **    May you share freely, never taking more than you give.

  201993. **

  201994. ******************************************************************************

  201995. **

  201996. */

  201997. #ifndef _FTS5INT_H

  201998. #define _FTS5INT_H

  201999. 

  202000. /* #include "fts5.h" */

  202001. /* #include "sqlite3ext.h" */

  202002. SQLITE_EXTENSION_INIT1

  202003. 

  202004. /* #include <string.h> */

  202005. /* #include <assert.h> */

  202006. 

  202007. #ifndef SQLITE_AMALGAMATION

  202008. 

  202009. typedef unsigned char  u8;

  202010. typedef unsigned int   u32;

  202011. typedef unsigned short u16;

  202012. typedef short i16;

  202013. typedef sqlite3_int64 i64;

  202014. typedef sqlite3_uint64 u64;

  202015. 

  202016. #ifndef ArraySize

  202017. # define ArraySize(x) ((int)(sizeof(x) / sizeof(x[0])))

  202018. #endif

  202019. 

  202020. #define testcase(x)

  202021. #define ALWAYS(x) 1

  202022. #define NEVER(x) 0

  202023. 

  202024. #define MIN(x,y) (((x) < (y)) ? (x) : (y))

  202025. #define MAX(x,y) (((x) > (y)) ? (x) : (y))

  202026. 

  202027. /*

  202028. ** Constants for the largest and smallest possible 64-bit signed integers.

  202029. */

  202030. # define LARGEST_INT64  (0xffffffff|(((i64)0x7fffffff)<<32))

  202031. # define SMALLEST_INT64 (((i64)-1) - LARGEST_INT64)

  202032. 

  202033. #endif

  202034. 

  202035. /* Truncate very long tokens to this many bytes. Hard limit is 

  202036. ** (65536-1-1-4-9)==65521 bytes. The limiting factor is the 16-bit offset

  202037. ** field that occurs at the start of each leaf page (see fts5_index.c). */

  202038. #define FTS5_MAX_TOKEN_SIZE 32768

  202039. 

  202040. /*

  202041. ** Maximum number of prefix indexes on single FTS5 table. This must be

  202042. ** less than 32. If it is set to anything large than that, an #error

  202043. ** directive in fts5_index.c will cause the build to fail.

  202044. */

  202045. #define FTS5_MAX_PREFIX_INDEXES 31

  202046. 

  202047. #define FTS5_DEFAULT_NEARDIST 10

  202048. #define FTS5_DEFAULT_RANK     "bm25"

  202049. 

  202050. /* Name of rank and rowid columns */

  202051. #define FTS5_RANK_NAME "rank"

  202052. #define FTS5_ROWID_NAME "rowid"

  202053. 

  202054. #ifdef SQLITE_DEBUG

  202055. # define FTS5_CORRUPT sqlite3Fts5Corrupt()

  202056. static int sqlite3Fts5Corrupt(void);

  202057. #else

  202058. # define FTS5_CORRUPT SQLITE_CORRUPT_VTAB

  202059. #endif

  202060. 

  202061. /*

  202062. ** The assert_nc() macro is similar to the assert() macro, except that it

  202063. ** is used for assert() conditions that are true only if it can be 

  202064. ** guranteed that the database is not corrupt.

  202065. */

  202066. #ifdef SQLITE_DEBUG

  202067. SQLITE_API extern int sqlite3_fts5_may_be_corrupt;

  202068. # define assert_nc(x) assert(sqlite3_fts5_may_be_corrupt || (x))

  202069. #else

  202070. # define assert_nc(x) assert(x)

  202071. #endif

  202072. 

  202073. /*

  202074. ** A version of memcmp() that does not cause asan errors if one of the pointer

  202075. ** parameters is NULL and the number of bytes to compare is zero.

  202076. */

  202077. #define fts5Memcmp(s1, s2, n) ((n)==0 ? 0 : memcmp((s1), (s2), (n)))

  202078. 

  202079. /* Mark a function parameter as unused, to suppress nuisance compiler

  202080. ** warnings. */

  202081. #ifndef UNUSED_PARAM

  202082. # define UNUSED_PARAM(X)  (void)(X)

  202083. #endif

  202084. 

  202085. #ifndef UNUSED_PARAM2

  202086. # define UNUSED_PARAM2(X, Y)  (void)(X), (void)(Y)

  202087. #endif

  202088. 

  202089. typedef struct Fts5Global Fts5Global;

  202090. typedef struct Fts5Colset Fts5Colset;

  202091. 

  202092. /* If a NEAR() clump or phrase may only match a specific set of columns, 

  202093. ** then an object of the following type is used to record the set of columns.

  202094. ** Each entry in the aiCol[] array is a column that may be matched.

  202095. **

  202096. ** This object is used by fts5_expr.c and fts5_index.c.

  202097. */

  202098. struct Fts5Colset {

  202099.   int nCol;

  202100.   int aiCol[1];

  202101. };

  202102. 

  202103. 

  202104. 

  202105. /**************************************************************************

  202106. ** Interface to code in fts5_config.c. fts5_config.c contains contains code

  202107. ** to parse the arguments passed to the CREATE VIRTUAL TABLE statement.

  202108. */

  202109. 

  202110. typedef struct Fts5Config Fts5Config;

  202111. 

  202112. /*

  202113. ** An instance of the following structure encodes all information that can

  202114. ** be gleaned from the CREATE VIRTUAL TABLE statement.

  202115. **

  202116. ** And all information loaded from the %_config table.

  202117. **

  202118. ** nAutomerge:

  202119. **   The minimum number of segments that an auto-merge operation should

  202120. **   attempt to merge together. A value of 1 sets the object to use the 

  202121. **   compile time default. Zero disables auto-merge altogether.

  202122. **

  202123. ** zContent:

  202124. **

  202125. ** zContentRowid:

  202126. **   The value of the content_rowid= option, if one was specified. Or 

  202127. **   the string "rowid" otherwise. This text is not quoted - if it is

  202128. **   used as part of an SQL statement it needs to be quoted appropriately.

  202129. **

  202130. ** zContentExprlist:

  202131. **

  202132. ** pzErrmsg:

  202133. **   This exists in order to allow the fts5_index.c module to return a 

  202134. **   decent error message if it encounters a file-format version it does

  202135. **   not understand.

  202136. **

  202137. ** bColumnsize:

  202138. **   True if the %_docsize table is created.

  202139. **

  202140. ** bPrefixIndex:

  202141. **   This is only used for debugging. If set to false, any prefix indexes

  202142. **   are ignored. This value is configured using:

  202143. **

  202144. **       INSERT INTO tbl(tbl, rank) VALUES('prefix-index', $bPrefixIndex);

  202145. **

  202146. */

  202147. struct Fts5Config {

  202148.   sqlite3 *db;                    /* Database handle */

  202149.   char *zDb;                      /* Database holding FTS index (e.g. "main") */

  202150.   char *zName;                    /* Name of FTS index */

  202151.   int nCol;                       /* Number of columns */

  202152.   char **azCol;                   /* Column names */

  202153.   u8 *abUnindexed;                /* True for unindexed columns */

  202154.   int nPrefix;                    /* Number of prefix indexes */

  202155.   int *aPrefix;                   /* Sizes in bytes of nPrefix prefix indexes */

  202156.   int eContent;                   /* An FTS5_CONTENT value */

  202157.   char *zContent;                 /* content table */ 

  202158.   char *zContentRowid;            /* "content_rowid=" option value */ 

  202159.   int bColumnsize;                /* "columnsize=" option value (dflt==1) */

  202160.   int eDetail;                    /* FTS5_DETAIL_XXX value */

  202161.   char *zContentExprlist;

  202162.   Fts5Tokenizer *pTok;

  202163.   fts5_tokenizer *pTokApi;

  202164. 

  202165.   /* Values loaded from the %_config table */

  202166.   int iCookie;                    /* Incremented when %_config is modified */

  202167.   int pgsz;                       /* Approximate page size used in %_data */

  202168.   int nAutomerge;                 /* 'automerge' setting */

  202169.   int nCrisisMerge;               /* Maximum allowed segments per level */

  202170.   int nUsermerge;                 /* 'usermerge' setting */

  202171.   int nHashSize;                  /* Bytes of memory for in-memory hash */

  202172.   char *zRank;                    /* Name of rank function */

  202173.   char *zRankArgs;                /* Arguments to rank function */

  202174. 

  202175.   /* If non-NULL, points to sqlite3_vtab.base.zErrmsg. Often NULL. */

  202176.   char **pzErrmsg;

  202177. 

  202178. #ifdef SQLITE_DEBUG

  202179.   int bPrefixIndex;               /* True to use prefix-indexes */

  202180. #endif

  202181. };

  202182. 

  202183. /* Current expected value of %_config table 'version' field */

  202184. #define FTS5_CURRENT_VERSION 4

  202185. 

  202186. #define FTS5_CONTENT_NORMAL   0

  202187. #define FTS5_CONTENT_NONE     1

  202188. #define FTS5_CONTENT_EXTERNAL 2

  202189. 

  202190. #define FTS5_DETAIL_FULL    0

  202191. #define FTS5_DETAIL_NONE    1

  202192. #define FTS5_DETAIL_COLUMNS 2

  202193. 

  202194. 

  202195. 

  202196. static int sqlite3Fts5ConfigParse(

  202197.     Fts5Global*, sqlite3*, int, const char **, Fts5Config**, char**

  202198. );

  202199. static void sqlite3Fts5ConfigFree(Fts5Config*);

  202200. 

  202201. static int sqlite3Fts5ConfigDeclareVtab(Fts5Config *pConfig);

  202202. 

  202203. static int sqlite3Fts5Tokenize(

  202204.   Fts5Config *pConfig,            /* FTS5 Configuration object */

  202205.   int flags,                      /* FTS5_TOKENIZE_* flags */

  202206.   const char *pText, int nText,   /* Text to tokenize */

  202207.   void *pCtx,                     /* Context passed to xToken() */

  202208.   int (*xToken)(void*, int, const char*, int, int, int)    /* Callback */

  202209. );

  202210. 

  202211. static void sqlite3Fts5Dequote(char *z);

  202212. 

  202213. /* Load the contents of the %_config table */

  202214. static int sqlite3Fts5ConfigLoad(Fts5Config*, int);

  202215. 

  202216. /* Set the value of a single config attribute */

  202217. static int sqlite3Fts5ConfigSetValue(Fts5Config*, const char*, sqlite3_value*, int*);

  202218. 

  202219. static int sqlite3Fts5ConfigParseRank(const char*, char**, char**);

  202220. 

  202221. /*

  202222. ** End of interface to code in fts5_config.c.

  202223. **************************************************************************/

  202224. 

  202225. /**************************************************************************

  202226. ** Interface to code in fts5_buffer.c.

  202227. */

  202228. 

  202229. /*

  202230. ** Buffer object for the incremental building of string data.

  202231. */

  202232. typedef struct Fts5Buffer Fts5Buffer;

  202233. struct Fts5Buffer {

  202234.   u8 *p;

  202235.   int n;

  202236.   int nSpace;

  202237. };

  202238. 

  202239. static int sqlite3Fts5BufferSize(int*, Fts5Buffer*, u32);

  202240. static void sqlite3Fts5BufferAppendVarint(int*, Fts5Buffer*, i64);

  202241. static void sqlite3Fts5BufferAppendBlob(int*, Fts5Buffer*, u32, const u8*);

  202242. static void sqlite3Fts5BufferAppendString(int *, Fts5Buffer*, const char*);

  202243. static void sqlite3Fts5BufferFree(Fts5Buffer*);

  202244. static void sqlite3Fts5BufferZero(Fts5Buffer*);

  202245. static void sqlite3Fts5BufferSet(int*, Fts5Buffer*, int, const u8*);

  202246. static void sqlite3Fts5BufferAppendPrintf(int *, Fts5Buffer*, char *zFmt, ...);

  202247. 

  202248. static char *sqlite3Fts5Mprintf(int *pRc, const char *zFmt, ...);

  202249. 

  202250. #define fts5BufferZero(x)             sqlite3Fts5BufferZero(x)

  202251. #define fts5BufferAppendVarint(a,b,c) sqlite3Fts5BufferAppendVarint(a,b,c)

  202252. #define fts5BufferFree(a)             sqlite3Fts5BufferFree(a)

  202253. #define fts5BufferAppendBlob(a,b,c,d) sqlite3Fts5BufferAppendBlob(a,b,c,d)

  202254. #define fts5BufferSet(a,b,c,d)        sqlite3Fts5BufferSet(a,b,c,d)

  202255. 

  202256. #define fts5BufferGrow(pRc,pBuf,nn) ( \

  202257.   (u32)((pBuf)->n) + (u32)(nn) <= (u32)((pBuf)->nSpace) ? 0 : \

  202258.     sqlite3Fts5BufferSize((pRc),(pBuf),(nn)+(pBuf)->n) \

  202259. )

  202260. 

  202261. /* Write and decode big-endian 32-bit integer values */

  202262. static void sqlite3Fts5Put32(u8*, int);

  202263. static int sqlite3Fts5Get32(const u8*);

  202264. 

  202265. #define FTS5_POS2COLUMN(iPos) (int)(iPos >> 32)

  202266. #define FTS5_POS2OFFSET(iPos) (int)(iPos & 0x7FFFFFFF)

  202267. 

  202268. typedef struct Fts5PoslistReader Fts5PoslistReader;

  202269. struct Fts5PoslistReader {

  202270.   /* Variables used only by sqlite3Fts5PoslistIterXXX() functions. */

  202271.   const u8 *a;                    /* Position list to iterate through */

  202272.   int n;                          /* Size of buffer at a[] in bytes */

  202273.   int i;                          /* Current offset in a[] */

  202274. 

  202275.   u8 bFlag;                       /* For client use (any custom purpose) */

  202276. 

  202277.   /* Output variables */

  202278.   u8 bEof;                        /* Set to true at EOF */

  202279.   i64 iPos;                       /* (iCol<<32) + iPos */

  202280. };

  202281. static int sqlite3Fts5PoslistReaderInit(

  202282.   const u8 *a, int n,             /* Poslist buffer to iterate through */

  202283.   Fts5PoslistReader *pIter        /* Iterator object to initialize */

  202284. );

  202285. static int sqlite3Fts5PoslistReaderNext(Fts5PoslistReader*);

  202286. 

  202287. typedef struct Fts5PoslistWriter Fts5PoslistWriter;

  202288. struct Fts5PoslistWriter {

  202289.   i64 iPrev;

  202290. };

  202291. static int sqlite3Fts5PoslistWriterAppend(Fts5Buffer*, Fts5PoslistWriter*, i64);

  202292. static void sqlite3Fts5PoslistSafeAppend(Fts5Buffer*, i64*, i64);

  202293. 

  202294. static int sqlite3Fts5PoslistNext64(

  202295.   const u8 *a, int n,             /* Buffer containing poslist */

  202296.   int *pi,                        /* IN/OUT: Offset within a[] */

  202297.   i64 *piOff                      /* IN/OUT: Current offset */

  202298. );

  202299. 

  202300. /* Malloc utility */

  202301. static void *sqlite3Fts5MallocZero(int *pRc, sqlite3_int64 nByte);

  202302. static char *sqlite3Fts5Strndup(int *pRc, const char *pIn, int nIn);

  202303. 

  202304. /* Character set tests (like isspace(), isalpha() etc.) */

  202305. static int sqlite3Fts5IsBareword(char t);

  202306. 

  202307. 

  202308. /* Bucket of terms object used by the integrity-check in offsets=0 mode. */

  202309. typedef struct Fts5Termset Fts5Termset;

  202310. static int sqlite3Fts5TermsetNew(Fts5Termset**);

  202311. static int sqlite3Fts5TermsetAdd(Fts5Termset*, int, const char*, int, int *pbPresent);

  202312. static void sqlite3Fts5TermsetFree(Fts5Termset*);

  202313. 

  202314. /*

  202315. ** End of interface to code in fts5_buffer.c.

  202316. **************************************************************************/

  202317. 

  202318. /**************************************************************************

  202319. ** Interface to code in fts5_index.c. fts5_index.c contains contains code

  202320. ** to access the data stored in the %_data table.

  202321. */

  202322. 

  202323. typedef struct Fts5Index Fts5Index;

  202324. typedef struct Fts5IndexIter Fts5IndexIter;

  202325. 

  202326. struct Fts5IndexIter {

  202327.   i64 iRowid;

  202328.   const u8 *pData;

  202329.   int nData;

  202330.   u8 bEof;

  202331. };

  202332. 

  202333. #define sqlite3Fts5IterEof(x) ((x)->bEof)

  202334. 

  202335. /*

  202336. ** Values used as part of the flags argument passed to IndexQuery().

  202337. */

  202338. #define FTS5INDEX_QUERY_PREFIX     0x0001   /* Prefix query */

  202339. #define FTS5INDEX_QUERY_DESC       0x0002   /* Docs in descending rowid order */

  202340. #define FTS5INDEX_QUERY_TEST_NOIDX 0x0004   /* Do not use prefix index */

  202341. #define FTS5INDEX_QUERY_SCAN       0x0008   /* Scan query (fts5vocab) */

  202342. 

  202343. /* The following are used internally by the fts5_index.c module. They are

  202344. ** defined here only to make it easier to avoid clashes with the flags

  202345. ** above. */

  202346. #define FTS5INDEX_QUERY_SKIPEMPTY  0x0010

  202347. #define FTS5INDEX_QUERY_NOOUTPUT   0x0020

  202348. 

  202349. /*

  202350. ** Create/destroy an Fts5Index object.

  202351. */

  202352. static int sqlite3Fts5IndexOpen(Fts5Config *pConfig, int bCreate, Fts5Index**, char**);

  202353. static int sqlite3Fts5IndexClose(Fts5Index *p);

  202354. 

  202355. /*

  202356. ** Return a simple checksum value based on the arguments.

  202357. */

  202358. static u64 sqlite3Fts5IndexEntryCksum(

  202359.   i64 iRowid, 

  202360.   int iCol, 

  202361.   int iPos, 

  202362.   int iIdx,

  202363.   const char *pTerm,

  202364.   int nTerm

  202365. );

  202366. 

  202367. /*

  202368. ** Argument p points to a buffer containing utf-8 text that is n bytes in 

  202369. ** size. Return the number of bytes in the nChar character prefix of the

  202370. ** buffer, or 0 if there are less than nChar characters in total.

  202371. */

  202372. static int sqlite3Fts5IndexCharlenToBytelen(

  202373.   const char *p, 

  202374.   int nByte, 

  202375.   int nChar

  202376. );

  202377. 

  202378. /*

  202379. ** Open a new iterator to iterate though all rowids that match the 

  202380. ** specified token or token prefix.

  202381. */

  202382. static int sqlite3Fts5IndexQuery(

  202383.   Fts5Index *p,                   /* FTS index to query */

  202384.   const char *pToken, int nToken, /* Token (or prefix) to query for */

  202385.   int flags,                      /* Mask of FTS5INDEX_QUERY_X flags */

  202386.   Fts5Colset *pColset,            /* Match these columns only */

  202387.   Fts5IndexIter **ppIter          /* OUT: New iterator object */

  202388. );

  202389. 

  202390. /*

  202391. ** The various operations on open token or token prefix iterators opened

  202392. ** using sqlite3Fts5IndexQuery().

  202393. */

  202394. static int sqlite3Fts5IterNext(Fts5IndexIter*);

  202395. static int sqlite3Fts5IterNextFrom(Fts5IndexIter*, i64 iMatch);

  202396. 

  202397. /*

  202398. ** Close an iterator opened by sqlite3Fts5IndexQuery().

  202399. */

  202400. static void sqlite3Fts5IterClose(Fts5IndexIter*);

  202401. 

  202402. /*

  202403. ** This interface is used by the fts5vocab module.

  202404. */

  202405. static const char *sqlite3Fts5IterTerm(Fts5IndexIter*, int*);

  202406. static int sqlite3Fts5IterNextScan(Fts5IndexIter*);

  202407. 

  202408. 

  202409. /*

  202410. ** Insert or remove data to or from the index. Each time a document is 

  202411. ** added to or removed from the index, this function is called one or more

  202412. ** times.

  202413. **

  202414. ** For an insert, it must be called once for each token in the new document.

  202415. ** If the operation is a delete, it must be called (at least) once for each

  202416. ** unique token in the document with an iCol value less than zero. The iPos

  202417. ** argument is ignored for a delete.

  202418. */

  202419. static int sqlite3Fts5IndexWrite(

  202420.   Fts5Index *p,                   /* Index to write to */

  202421.   int iCol,                       /* Column token appears in (-ve -> delete) */

  202422.   int iPos,                       /* Position of token within column */

  202423.   const char *pToken, int nToken  /* Token to add or remove to or from index */

  202424. );

  202425. 

  202426. /*

  202427. ** Indicate that subsequent calls to sqlite3Fts5IndexWrite() pertain to

  202428. ** document iDocid.

  202429. */

  202430. static int sqlite3Fts5IndexBeginWrite(

  202431.   Fts5Index *p,                   /* Index to write to */

  202432.   int bDelete,                    /* True if current operation is a delete */

  202433.   i64 iDocid                      /* Docid to add or remove data from */

  202434. );

  202435. 

  202436. /*

  202437. ** Flush any data stored in the in-memory hash tables to the database.

  202438. ** Also close any open blob handles.

  202439. */

  202440. static int sqlite3Fts5IndexSync(Fts5Index *p);

  202441. 

  202442. /*

  202443. ** Discard any data stored in the in-memory hash tables. Do not write it

  202444. ** to the database. Additionally, assume that the contents of the %_data

  202445. ** table may have changed on disk. So any in-memory caches of %_data 

  202446. ** records must be invalidated.

  202447. */

  202448. static int sqlite3Fts5IndexRollback(Fts5Index *p);

  202449. 

  202450. /*

  202451. ** Get or set the "averages" values.

  202452. */

  202453. static int sqlite3Fts5IndexGetAverages(Fts5Index *p, i64 *pnRow, i64 *anSize);

  202454. static int sqlite3Fts5IndexSetAverages(Fts5Index *p, const u8*, int);

  202455. 

  202456. /*

  202457. ** Functions called by the storage module as part of integrity-check.

  202458. */

  202459. static int sqlite3Fts5IndexIntegrityCheck(Fts5Index*, u64 cksum);

  202460. 

  202461. /* 

  202462. ** Called during virtual module initialization to register UDF 

  202463. ** fts5_decode() with SQLite 

  202464. */

  202465. static int sqlite3Fts5IndexInit(sqlite3*);

  202466. 

  202467. static int sqlite3Fts5IndexSetCookie(Fts5Index*, int);

  202468. 

  202469. /*

  202470. ** Return the total number of entries read from the %_data table by 

  202471. ** this connection since it was created.

  202472. */

  202473. static int sqlite3Fts5IndexReads(Fts5Index *p);

  202474. 

  202475. static int sqlite3Fts5IndexReinit(Fts5Index *p);

  202476. static int sqlite3Fts5IndexOptimize(Fts5Index *p);

  202477. static int sqlite3Fts5IndexMerge(Fts5Index *p, int nMerge);

  202478. static int sqlite3Fts5IndexReset(Fts5Index *p);

  202479. 

  202480. static int sqlite3Fts5IndexLoadConfig(Fts5Index *p);

  202481. 

  202482. /*

  202483. ** End of interface to code in fts5_index.c.

  202484. **************************************************************************/

  202485. 

  202486. /**************************************************************************

  202487. ** Interface to code in fts5_varint.c. 

  202488. */

  202489. static int sqlite3Fts5GetVarint32(const unsigned char *p, u32 *v);

  202490. static int sqlite3Fts5GetVarintLen(u32 iVal);

  202491. static u8 sqlite3Fts5GetVarint(const unsigned char*, u64*);

  202492. static int sqlite3Fts5PutVarint(unsigned char *p, u64 v);

  202493. 

  202494. #define fts5GetVarint32(a,b) sqlite3Fts5GetVarint32(a,(u32*)&b)

  202495. #define fts5GetVarint    sqlite3Fts5GetVarint

  202496. 

  202497. #define fts5FastGetVarint32(a, iOff, nVal) {      \

  202498.   nVal = (a)[iOff++];                             \

  202499.   if( nVal & 0x80 ){                              \

  202500.     iOff--;                                       \

  202501.     iOff += fts5GetVarint32(&(a)[iOff], nVal);    \

  202502.   }                                               \

  202503. }

  202504. 

  202505. 

  202506. /*

  202507. ** End of interface to code in fts5_varint.c.

  202508. **************************************************************************/

  202509. 

  202510. 

  202511. /**************************************************************************

  202512. ** Interface to code in fts5_main.c. 

  202513. */

  202514. 

  202515. /*

  202516. ** Virtual-table object.

  202517. */

  202518. typedef struct Fts5Table Fts5Table;

  202519. struct Fts5Table {

  202520.   sqlite3_vtab base;              /* Base class used by SQLite core */

  202521.   Fts5Config *pConfig;            /* Virtual table configuration */

  202522.   Fts5Index *pIndex;              /* Full-text index */

  202523. };

  202524. 

  202525. static int sqlite3Fts5GetTokenizer(

  202526.   Fts5Global*, 

  202527.   const char **azArg,

  202528.   int nArg,

  202529.   Fts5Tokenizer**,

  202530.   fts5_tokenizer**,

  202531.   char **pzErr

  202532. );

  202533. 

  202534. static Fts5Table *sqlite3Fts5TableFromCsrid(Fts5Global*, i64);

  202535. 

  202536. static int sqlite3Fts5FlushToDisk(Fts5Table*);

  202537. 

  202538. /*

  202539. ** End of interface to code in fts5.c.

  202540. **************************************************************************/

  202541. 

  202542. /**************************************************************************

  202543. ** Interface to code in fts5_hash.c. 

  202544. */

  202545. typedef struct Fts5Hash Fts5Hash;

  202546. 

  202547. /*

  202548. ** Create a hash table, free a hash table.

  202549. */

  202550. static int sqlite3Fts5HashNew(Fts5Config*, Fts5Hash**, int *pnSize);

  202551. static void sqlite3Fts5HashFree(Fts5Hash*);

  202552. 

  202553. static int sqlite3Fts5HashWrite(

  202554.   Fts5Hash*,

  202555.   i64 iRowid,                     /* Rowid for this entry */

  202556.   int iCol,                       /* Column token appears in (-ve -> delete) */

  202557.   int iPos,                       /* Position of token within column */

  202558.   char bByte,

  202559.   const char *pToken, int nToken  /* Token to add or remove to or from index */

  202560. );

  202561. 

  202562. /*

  202563. ** Empty (but do not delete) a hash table.

  202564. */

  202565. static void sqlite3Fts5HashClear(Fts5Hash*);

  202566. 

  202567. static int sqlite3Fts5HashQuery(

  202568.   Fts5Hash*,                      /* Hash table to query */

  202569.   int nPre,

  202570.   const char *pTerm, int nTerm,   /* Query term */

  202571.   void **ppObj,                   /* OUT: Pointer to doclist for pTerm */

  202572.   int *pnDoclist                  /* OUT: Size of doclist in bytes */

  202573. );

  202574. 

  202575. static int sqlite3Fts5HashScanInit(

  202576.   Fts5Hash*,                      /* Hash table to query */

  202577.   const char *pTerm, int nTerm    /* Query prefix */

  202578. );

  202579. static void sqlite3Fts5HashScanNext(Fts5Hash*);

  202580. static int sqlite3Fts5HashScanEof(Fts5Hash*);

  202581. static void sqlite3Fts5HashScanEntry(Fts5Hash *,

  202582.   const char **pzTerm,            /* OUT: term (nul-terminated) */

  202583.   const u8 **ppDoclist,           /* OUT: pointer to doclist */

  202584.   int *pnDoclist                  /* OUT: size of doclist in bytes */

  202585. );

  202586. 

  202587. 

  202588. /*

  202589. ** End of interface to code in fts5_hash.c.

  202590. **************************************************************************/

  202591. 

  202592. /**************************************************************************

  202593. ** Interface to code in fts5_storage.c. fts5_storage.c contains contains 

  202594. ** code to access the data stored in the %_content and %_docsize tables.

  202595. */

  202596. 

  202597. #define FTS5_STMT_SCAN_ASC  0     /* SELECT rowid, * FROM ... ORDER BY 1 ASC */

  202598. #define FTS5_STMT_SCAN_DESC 1     /* SELECT rowid, * FROM ... ORDER BY 1 DESC */

  202599. #define FTS5_STMT_LOOKUP    2     /* SELECT rowid, * FROM ... WHERE rowid=? */

  202600. 

  202601. typedef struct Fts5Storage Fts5Storage;

  202602. 

  202603. static int sqlite3Fts5StorageOpen(Fts5Config*, Fts5Index*, int, Fts5Storage**, char**);

  202604. static int sqlite3Fts5StorageClose(Fts5Storage *p);

  202605. static int sqlite3Fts5StorageRename(Fts5Storage*, const char *zName);

  202606. 

  202607. static int sqlite3Fts5DropAll(Fts5Config*);

  202608. static int sqlite3Fts5CreateTable(Fts5Config*, const char*, const char*, int, char **);

  202609. 

  202610. static int sqlite3Fts5StorageDelete(Fts5Storage *p, i64, sqlite3_value**);

  202611. static int sqlite3Fts5StorageContentInsert(Fts5Storage *p, sqlite3_value**, i64*);

  202612. static int sqlite3Fts5StorageIndexInsert(Fts5Storage *p, sqlite3_value**, i64);

  202613. 

  202614. static int sqlite3Fts5StorageIntegrity(Fts5Storage *p);

  202615. 

  202616. static int sqlite3Fts5StorageStmt(Fts5Storage *p, int eStmt, sqlite3_stmt**, char**);

  202617. static void sqlite3Fts5StorageStmtRelease(Fts5Storage *p, int eStmt, sqlite3_stmt*);

  202618. 

  202619. static int sqlite3Fts5StorageDocsize(Fts5Storage *p, i64 iRowid, int *aCol);

  202620. static int sqlite3Fts5StorageSize(Fts5Storage *p, int iCol, i64 *pnAvg);

  202621. static int sqlite3Fts5StorageRowCount(Fts5Storage *p, i64 *pnRow);

  202622. 

  202623. static int sqlite3Fts5StorageSync(Fts5Storage *p);

  202624. static int sqlite3Fts5StorageRollback(Fts5Storage *p);

  202625. 

  202626. static int sqlite3Fts5StorageConfigValue(

  202627.     Fts5Storage *p, const char*, sqlite3_value*, int

  202628. );

  202629. 

  202630. static int sqlite3Fts5StorageDeleteAll(Fts5Storage *p);

  202631. static int sqlite3Fts5StorageRebuild(Fts5Storage *p);

  202632. static int sqlite3Fts5StorageOptimize(Fts5Storage *p);

  202633. static int sqlite3Fts5StorageMerge(Fts5Storage *p, int nMerge);

  202634. static int sqlite3Fts5StorageReset(Fts5Storage *p);

  202635. 

  202636. /*

  202637. ** End of interface to code in fts5_storage.c.

  202638. **************************************************************************/

  202639. 

  202640. 

  202641. /**************************************************************************

  202642. ** Interface to code in fts5_expr.c. 

  202643. */

  202644. typedef struct Fts5Expr Fts5Expr;

  202645. typedef struct Fts5ExprNode Fts5ExprNode;

  202646. typedef struct Fts5Parse Fts5Parse;

  202647. typedef struct Fts5Token Fts5Token;

  202648. typedef struct Fts5ExprPhrase Fts5ExprPhrase;

  202649. typedef struct Fts5ExprNearset Fts5ExprNearset;

  202650. 

  202651. struct Fts5Token {

  202652.   const char *p;                  /* Token text (not NULL terminated) */

  202653.   int n;                          /* Size of buffer p in bytes */

  202654. };

  202655. 

  202656. /* Parse a MATCH expression. */

  202657. static int sqlite3Fts5ExprNew(

  202658.   Fts5Config *pConfig, 

  202659.   int iCol,                       /* Column on LHS of MATCH operator */

  202660.   const char *zExpr,

  202661.   Fts5Expr **ppNew, 

  202662.   char **pzErr

  202663. );

  202664. 

  202665. /*

  202666. ** for(rc = sqlite3Fts5ExprFirst(pExpr, pIdx, bDesc);

  202667. **     rc==SQLITE_OK && 0==sqlite3Fts5ExprEof(pExpr);

  202668. **     rc = sqlite3Fts5ExprNext(pExpr)

  202669. ** ){

  202670. **   // The document with rowid iRowid matches the expression!

  202671. **   i64 iRowid = sqlite3Fts5ExprRowid(pExpr);

  202672. ** }

  202673. */

  202674. static int sqlite3Fts5ExprFirst(Fts5Expr*, Fts5Index *pIdx, i64 iMin, int bDesc);

  202675. static int sqlite3Fts5ExprNext(Fts5Expr*, i64 iMax);

  202676. static int sqlite3Fts5ExprEof(Fts5Expr*);

  202677. static i64 sqlite3Fts5ExprRowid(Fts5Expr*);

  202678. 

  202679. static void sqlite3Fts5ExprFree(Fts5Expr*);

  202680. 

  202681. /* Called during startup to register a UDF with SQLite */

  202682. static int sqlite3Fts5ExprInit(Fts5Global*, sqlite3*);

  202683. 

  202684. static int sqlite3Fts5ExprPhraseCount(Fts5Expr*);

  202685. static int sqlite3Fts5ExprPhraseSize(Fts5Expr*, int iPhrase);

  202686. static int sqlite3Fts5ExprPoslist(Fts5Expr*, int, const u8 **);

  202687. 

  202688. typedef struct Fts5PoslistPopulator Fts5PoslistPopulator;

  202689. static Fts5PoslistPopulator *sqlite3Fts5ExprClearPoslists(Fts5Expr*, int);

  202690. static int sqlite3Fts5ExprPopulatePoslists(

  202691.     Fts5Config*, Fts5Expr*, Fts5PoslistPopulator*, int, const char*, int

  202692. );

  202693. static void sqlite3Fts5ExprCheckPoslists(Fts5Expr*, i64);

  202694. 

  202695. static int sqlite3Fts5ExprClonePhrase(Fts5Expr*, int, Fts5Expr**);

  202696. 

  202697. static int sqlite3Fts5ExprPhraseCollist(Fts5Expr *, int, const u8 **, int *);

  202698. 

  202699. /*******************************************

  202700. ** The fts5_expr.c API above this point is used by the other hand-written

  202701. ** C code in this module. The interfaces below this point are called by

  202702. ** the parser code in fts5parse.y.  */

  202703. 

  202704. static void sqlite3Fts5ParseError(Fts5Parse *pParse, const char *zFmt, ...);

  202705. 

  202706. static Fts5ExprNode *sqlite3Fts5ParseNode(

  202707.   Fts5Parse *pParse,

  202708.   int eType,

  202709.   Fts5ExprNode *pLeft,

  202710.   Fts5ExprNode *pRight,

  202711.   Fts5ExprNearset *pNear

  202712. );

  202713. 

  202714. static Fts5ExprNode *sqlite3Fts5ParseImplicitAnd(

  202715.   Fts5Parse *pParse,

  202716.   Fts5ExprNode *pLeft,

  202717.   Fts5ExprNode *pRight

  202718. );

  202719. 

  202720. static Fts5ExprPhrase *sqlite3Fts5ParseTerm(

  202721.   Fts5Parse *pParse, 

  202722.   Fts5ExprPhrase *pPhrase, 

  202723.   Fts5Token *pToken,

  202724.   int bPrefix

  202725. );

  202726. 

  202727. static void sqlite3Fts5ParseSetCaret(Fts5ExprPhrase*);

  202728. 

  202729. static Fts5ExprNearset *sqlite3Fts5ParseNearset(

  202730.   Fts5Parse*, 

  202731.   Fts5ExprNearset*,

  202732.   Fts5ExprPhrase* 

  202733. );

  202734. 

  202735. static Fts5Colset *sqlite3Fts5ParseColset(

  202736.   Fts5Parse*, 

  202737.   Fts5Colset*, 

  202738.   Fts5Token *

  202739. );

  202740. 

  202741. static void sqlite3Fts5ParsePhraseFree(Fts5ExprPhrase*);

  202742. static void sqlite3Fts5ParseNearsetFree(Fts5ExprNearset*);

  202743. static void sqlite3Fts5ParseNodeFree(Fts5ExprNode*);

  202744. 

  202745. static void sqlite3Fts5ParseSetDistance(Fts5Parse*, Fts5ExprNearset*, Fts5Token*);

  202746. static void sqlite3Fts5ParseSetColset(Fts5Parse*, Fts5ExprNode*, Fts5Colset*);

  202747. static Fts5Colset *sqlite3Fts5ParseColsetInvert(Fts5Parse*, Fts5Colset*);

  202748. static void sqlite3Fts5ParseFinished(Fts5Parse *pParse, Fts5ExprNode *p);

  202749. static void sqlite3Fts5ParseNear(Fts5Parse *pParse, Fts5Token*);

  202750. 

  202751. /*

  202752. ** End of interface to code in fts5_expr.c.

  202753. **************************************************************************/

  202754. 

  202755. 

  202756. 

  202757. /**************************************************************************

  202758. ** Interface to code in fts5_aux.c. 

  202759. */

  202760. 

  202761. static int sqlite3Fts5AuxInit(fts5_api*);

  202762. /*

  202763. ** End of interface to code in fts5_aux.c.

  202764. **************************************************************************/

  202765. 

  202766. /**************************************************************************

  202767. ** Interface to code in fts5_tokenizer.c. 

  202768. */

  202769. 

  202770. static int sqlite3Fts5TokenizerInit(fts5_api*);

  202771. /*

  202772. ** End of interface to code in fts5_tokenizer.c.

  202773. **************************************************************************/

  202774. 

  202775. /**************************************************************************

  202776. ** Interface to code in fts5_vocab.c. 

  202777. */

  202778. 

  202779. static int sqlite3Fts5VocabInit(Fts5Global*, sqlite3*);

  202780. 

  202781. /*

  202782. ** End of interface to code in fts5_vocab.c.

  202783. **************************************************************************/

  202784. 

  202785. 

  202786. /**************************************************************************

  202787. ** Interface to automatically generated code in fts5_unicode2.c. 

  202788. */

  202789. static int sqlite3Fts5UnicodeIsdiacritic(int c);

  202790. static int sqlite3Fts5UnicodeFold(int c, int bRemoveDiacritic);

  202791. 

  202792. static int sqlite3Fts5UnicodeCatParse(const char*, u8*);

  202793. static int sqlite3Fts5UnicodeCategory(u32 iCode);

  202794. static void sqlite3Fts5UnicodeAscii(u8*, u8*);

  202795. /*

  202796. ** End of interface to code in fts5_unicode2.c.

  202797. **************************************************************************/

  202798. 

  202799. #endif

  202800. 

  202801. #define FTS5_OR                               1

  202802. #define FTS5_AND                              2

  202803. #define FTS5_NOT                              3

  202804. #define FTS5_TERM                             4

  202805. #define FTS5_COLON                            5

  202806. #define FTS5_MINUS                            6

  202807. #define FTS5_LCP                              7

  202808. #define FTS5_RCP                              8

  202809. #define FTS5_STRING                           9

  202810. #define FTS5_LP                              10

  202811. #define FTS5_RP                              11

  202812. #define FTS5_CARET                           12

  202813. #define FTS5_COMMA                           13

  202814. #define FTS5_PLUS                            14

  202815. #define FTS5_STAR                            15

  202816. 

  202817. /*

  202818. ** 2000-05-29

  202819. **

  202820. ** The author disclaims copyright to this source code.  In place of

  202821. ** a legal notice, here is a blessing:

  202822. **

  202823. **    May you do good and not evil.

  202824. **    May you find forgiveness for yourself and forgive others.

  202825. **    May you share freely, never taking more than you give.

  202826. **

  202827. *************************************************************************

  202828. ** Driver template for the LEMON parser generator.

  202829. **

  202830. ** The "lemon" program processes an LALR(1) input grammar file, then uses

  202831. ** this template to construct a parser.  The "lemon" program inserts text

  202832. ** at each "%%" line.  Also, any "P-a-r-s-e" identifer prefix (without the

  202833. ** interstitial "-" characters) contained in this template is changed into

  202834. ** the value of the %name directive from the grammar.  Otherwise, the content

  202835. ** of this template is copied straight through into the generate parser

  202836. ** source file.

  202837. **

  202838. ** The following is the concatenation of all %include directives from the

  202839. ** input grammar file:

  202840. */

  202841. /* #include <stdio.h> */

  202842. /* #include <assert.h> */

  202843. /************ Begin %include sections from the grammar ************************/

  202844. 

  202845. /* #include "fts5Int.h" */

  202846. /* #include "fts5parse.h" */

  202847. 

  202848. /*

  202849. ** Disable all error recovery processing in the parser push-down

  202850. ** automaton.

  202851. */

  202852. #define fts5YYNOERRORRECOVERY 1

  202853. 

  202854. /*

  202855. ** Make fts5yytestcase() the same as testcase()

  202856. */

  202857. #define fts5yytestcase(X) testcase(X)

  202858. 

  202859. /*

  202860. ** Indicate that sqlite3ParserFree() will never be called with a null

  202861. ** pointer.

  202862. */

  202863. #define fts5YYPARSEFREENOTNULL 1

  202864. 

  202865. /*

  202866. ** Alternative datatype for the argument to the malloc() routine passed

  202867. ** into sqlite3ParserAlloc().  The default is size_t.

  202868. */

  202869. #define fts5YYMALLOCARGTYPE  u64

  202870. 

  202871. /**************** End of %include directives **********************************/

  202872. /* These constants specify the various numeric values for terminal symbols

  202873. ** in a format understandable to "makeheaders".  This section is blank unless

  202874. ** "lemon" is run with the "-m" command-line option.

  202875. ***************** Begin makeheaders token definitions *************************/

  202876. /**************** End makeheaders token definitions ***************************/

  202877. 

  202878. /* The next sections is a series of control #defines.

  202879. ** various aspects of the generated parser.

  202880. **    fts5YYCODETYPE         is the data type used to store the integer codes

  202881. **                       that represent terminal and non-terminal symbols.

  202882. **                       "unsigned char" is used if there are fewer than

  202883. **                       256 symbols.  Larger types otherwise.

  202884. **    fts5YYNOCODE           is a number of type fts5YYCODETYPE that is not used for

  202885. **                       any terminal or nonterminal symbol.

  202886. **    fts5YYFALLBACK         If defined, this indicates that one or more tokens

  202887. **                       (also known as: "terminal symbols") have fall-back

  202888. **                       values which should be used if the original symbol

  202889. **                       would not parse.  This permits keywords to sometimes

  202890. **                       be used as identifiers, for example.

  202891. **    fts5YYACTIONTYPE       is the data type used for "action codes" - numbers

  202892. **                       that indicate what to do in response to the next

  202893. **                       token.

  202894. **    sqlite3Fts5ParserFTS5TOKENTYPE     is the data type used for minor type for terminal

  202895. **                       symbols.  Background: A "minor type" is a semantic

  202896. **                       value associated with a terminal or non-terminal

  202897. **                       symbols.  For example, for an "ID" terminal symbol,

  202898. **                       the minor type might be the name of the identifier.

  202899. **                       Each non-terminal can have a different minor type.

  202900. **                       Terminal symbols all have the same minor type, though.

  202901. **                       This macros defines the minor type for terminal 

  202902. **                       symbols.

  202903. **    fts5YYMINORTYPE        is the data type used for all minor types.

  202904. **                       This is typically a union of many types, one of

  202905. **                       which is sqlite3Fts5ParserFTS5TOKENTYPE.  The entry in the union

  202906. **                       for terminal symbols is called "fts5yy0".

  202907. **    fts5YYSTACKDEPTH       is the maximum depth of the parser's stack.  If

  202908. **                       zero the stack is dynamically sized using realloc()

  202909. **    sqlite3Fts5ParserARG_SDECL     A static variable declaration for the %extra_argument

  202910. **    sqlite3Fts5ParserARG_PDECL     A parameter declaration for the %extra_argument

  202911. **    sqlite3Fts5ParserARG_PARAM     Code to pass %extra_argument as a subroutine parameter

  202912. **    sqlite3Fts5ParserARG_STORE     Code to store %extra_argument into fts5yypParser

  202913. **    sqlite3Fts5ParserARG_FETCH     Code to extract %extra_argument from fts5yypParser

  202914. **    sqlite3Fts5ParserCTX_*         As sqlite3Fts5ParserARG_ except for %extra_context

  202915. **    fts5YYERRORSYMBOL      is the code number of the error symbol.  If not

  202916. **                       defined, then do no error processing.

  202917. **    fts5YYNSTATE           the combined number of states.

  202918. **    fts5YYNRULE            the number of rules in the grammar

  202919. **    fts5YYNFTS5TOKEN           Number of terminal symbols

  202920. **    fts5YY_MAX_SHIFT       Maximum value for shift actions

  202921. **    fts5YY_MIN_SHIFTREDUCE Minimum value for shift-reduce actions

  202922. **    fts5YY_MAX_SHIFTREDUCE Maximum value for shift-reduce actions

  202923. **    fts5YY_ERROR_ACTION    The fts5yy_action[] code for syntax error

  202924. **    fts5YY_ACCEPT_ACTION   The fts5yy_action[] code for accept

  202925. **    fts5YY_NO_ACTION       The fts5yy_action[] code for no-op

  202926. **    fts5YY_MIN_REDUCE      Minimum value for reduce actions

  202927. **    fts5YY_MAX_REDUCE      Maximum value for reduce actions

  202928. */

  202929. #ifndef INTERFACE

  202930. # define INTERFACE 1

  202931. #endif

  202932. /************* Begin control #defines *****************************************/

  202933. #define fts5YYCODETYPE unsigned char

  202934. #define fts5YYNOCODE 27

  202935. #define fts5YYACTIONTYPE unsigned char

  202936. #define sqlite3Fts5ParserFTS5TOKENTYPE Fts5Token

  202937. typedef union {

  202938.   int fts5yyinit;

  202939.   sqlite3Fts5ParserFTS5TOKENTYPE fts5yy0;

  202940.   int fts5yy4;

  202941.   Fts5Colset* fts5yy11;

  202942.   Fts5ExprNode* fts5yy24;

  202943.   Fts5ExprNearset* fts5yy46;

  202944.   Fts5ExprPhrase* fts5yy53;

  202945. } fts5YYMINORTYPE;

  202946. #ifndef fts5YYSTACKDEPTH

  202947. #define fts5YYSTACKDEPTH 100

  202948. #endif

  202949. #define sqlite3Fts5ParserARG_SDECL Fts5Parse *pParse;

  202950. #define sqlite3Fts5ParserARG_PDECL ,Fts5Parse *pParse

  202951. #define sqlite3Fts5ParserARG_PARAM ,pParse

  202952. #define sqlite3Fts5ParserARG_FETCH Fts5Parse *pParse=fts5yypParser->pParse;

  202953. #define sqlite3Fts5ParserARG_STORE fts5yypParser->pParse=pParse;

  202954. #define sqlite3Fts5ParserCTX_SDECL

  202955. #define sqlite3Fts5ParserCTX_PDECL

  202956. #define sqlite3Fts5ParserCTX_PARAM

  202957. #define sqlite3Fts5ParserCTX_FETCH

  202958. #define sqlite3Fts5ParserCTX_STORE

  202959. #define fts5YYNSTATE             35

  202960. #define fts5YYNRULE              28

  202961. #define fts5YYNFTS5TOKEN             16

  202962. #define fts5YY_MAX_SHIFT         34

  202963. #define fts5YY_MIN_SHIFTREDUCE   52

  202964. #define fts5YY_MAX_SHIFTREDUCE   79

  202965. #define fts5YY_ERROR_ACTION      80

  202966. #define fts5YY_ACCEPT_ACTION     81

  202967. #define fts5YY_NO_ACTION         82

  202968. #define fts5YY_MIN_REDUCE        83

  202969. #define fts5YY_MAX_REDUCE        110

  202970. /************* End control #defines *******************************************/

  202971. #define fts5YY_NLOOKAHEAD ((int)(sizeof(fts5yy_lookahead)/sizeof(fts5yy_lookahead[0])))

  202972. 

  202973. /* Define the fts5yytestcase() macro to be a no-op if is not already defined

  202974. ** otherwise.

  202975. **

  202976. ** Applications can choose to define fts5yytestcase() in the %include section

  202977. ** to a macro that can assist in verifying code coverage.  For production

  202978. ** code the fts5yytestcase() macro should be turned off.  But it is useful

  202979. ** for testing.

  202980. */

  202981. #ifndef fts5yytestcase

  202982. # define fts5yytestcase(X)

  202983. #endif

  202984. 

  202985. 

  202986. /* Next are the tables used to determine what action to take based on the

  202987. ** current state and lookahead token.  These tables are used to implement

  202988. ** functions that take a state number and lookahead value and return an

  202989. ** action integer.  

  202990. **

  202991. ** Suppose the action integer is N.  Then the action is determined as

  202992. ** follows

  202993. **

  202994. **   0 <= N <= fts5YY_MAX_SHIFT             Shift N.  That is, push the lookahead

  202995. **                                      token onto the stack and goto state N.

  202996. **

  202997. **   N between fts5YY_MIN_SHIFTREDUCE       Shift to an arbitrary state then

  202998. **     and fts5YY_MAX_SHIFTREDUCE           reduce by rule N-fts5YY_MIN_SHIFTREDUCE.

  202999. **

  203000. **   N == fts5YY_ERROR_ACTION               A syntax error has occurred.

  203001. **

  203002. **   N == fts5YY_ACCEPT_ACTION              The parser accepts its input.

  203003. **

  203004. **   N == fts5YY_NO_ACTION                  No such action.  Denotes unused

  203005. **                                      slots in the fts5yy_action[] table.

  203006. **

  203007. **   N between fts5YY_MIN_REDUCE            Reduce by rule N-fts5YY_MIN_REDUCE

  203008. **     and fts5YY_MAX_REDUCE

  203009. **

  203010. ** The action table is constructed as a single large table named fts5yy_action[].

  203011. ** Given state S and lookahead X, the action is computed as either:

  203012. **

  203013. **    (A)   N = fts5yy_action[ fts5yy_shift_ofst[S] + X ]

  203014. **    (B)   N = fts5yy_default[S]

  203015. **

  203016. ** The (A) formula is preferred.  The B formula is used instead if

  203017. ** fts5yy_lookahead[fts5yy_shift_ofst[S]+X] is not equal to X.

  203018. **

  203019. ** The formulas above are for computing the action when the lookahead is

  203020. ** a terminal symbol.  If the lookahead is a non-terminal (as occurs after

  203021. ** a reduce action) then the fts5yy_reduce_ofst[] array is used in place of

  203022. ** the fts5yy_shift_ofst[] array.

  203023. **

  203024. ** The following are the tables generated in this section:

  203025. **

  203026. **  fts5yy_action[]        A single table containing all actions.

  203027. **  fts5yy_lookahead[]     A table containing the lookahead for each entry in

  203028. **                     fts5yy_action.  Used to detect hash collisions.

  203029. **  fts5yy_shift_ofst[]    For each state, the offset into fts5yy_action for

  203030. **                     shifting terminals.

  203031. **  fts5yy_reduce_ofst[]   For each state, the offset into fts5yy_action for

  203032. **                     shifting non-terminals after a reduce.

  203033. **  fts5yy_default[]       Default action for each state.

  203034. **

  203035. *********** Begin parsing tables **********************************************/

  203036. #define fts5YY_ACTTAB_COUNT (105)

  203037. static const fts5YYACTIONTYPE fts5yy_action[] = {

  203038.  /*     0 */    81,   20,   96,    6,   28,   99,   98,   26,   26,   18,

  203039.  /*    10 */    96,    6,   28,   17,   98,   56,   26,   19,   96,    6,

  203040.  /*    20 */    28,   14,   98,   14,   26,   31,   92,   96,    6,   28,

  203041.  /*    30 */   108,   98,   25,   26,   21,   96,    6,   28,   78,   98,

  203042.  /*    40 */    58,   26,   29,   96,    6,   28,  107,   98,   22,   26,

  203043.  /*    50 */    24,   16,   12,   11,    1,   13,   13,   24,   16,   23,

  203044.  /*    60 */    11,   33,   34,   13,   97,    8,   27,   32,   98,    7,

  203045.  /*    70 */    26,    3,    4,    5,    3,    4,    5,    3,   83,    4,

  203046.  /*    80 */     5,    3,   63,    5,    3,   62,   12,    2,   86,   13,

  203047.  /*    90 */     9,   30,   10,   10,   54,   57,   75,   78,   78,   53,

  203048.  /*   100 */    57,   15,   82,   82,   71,

  203049. };

  203050. static const fts5YYCODETYPE fts5yy_lookahead[] = {

  203051.  /*     0 */    16,   17,   18,   19,   20,   22,   22,   24,   24,   17,

  203052.  /*    10 */    18,   19,   20,    7,   22,    9,   24,   17,   18,   19,

  203053.  /*    20 */    20,    9,   22,    9,   24,   13,   17,   18,   19,   20,

  203054.  /*    30 */    26,   22,   24,   24,   17,   18,   19,   20,   15,   22,

  203055.  /*    40 */     9,   24,   17,   18,   19,   20,   26,   22,   21,   24,

  203056.  /*    50 */     6,    7,    9,    9,   10,   12,   12,    6,    7,   21,

  203057.  /*    60 */     9,   24,   25,   12,   18,    5,   20,   14,   22,    5,

  203058.  /*    70 */    24,    3,    1,    2,    3,    1,    2,    3,    0,    1,

  203059.  /*    80 */     2,    3,   11,    2,    3,   11,    9,   10,    5,   12,

  203060.  /*    90 */    23,   24,   10,   10,    8,    9,    9,   15,   15,    8,

  203061.  /*   100 */     9,    9,   27,   27,   11,   27,   27,   27,   27,   27,

  203062.  /*   110 */    27,   27,   27,   27,   27,   27,   27,   27,   27,   27,

  203063.  /*   120 */    27,

  203064. };

  203065. #define fts5YY_SHIFT_COUNT    (34)

  203066. #define fts5YY_SHIFT_MIN      (0)

  203067. #define fts5YY_SHIFT_MAX      (93)

  203068. static const unsigned char fts5yy_shift_ofst[] = {

  203069.  /*     0 */    44,   44,   44,   44,   44,   44,   51,   77,   43,   12,

  203070.  /*    10 */    14,   83,   82,   14,   23,   23,   31,   31,   71,   74,

  203071.  /*    20 */    78,   81,   86,   91,    6,   53,   53,   60,   64,   68,

  203072.  /*    30 */    53,   87,   92,   53,   93,

  203073. };

  203074. #define fts5YY_REDUCE_COUNT (17)

  203075. #define fts5YY_REDUCE_MIN   (-17)

  203076. #define fts5YY_REDUCE_MAX   (67)

  203077. static const signed char fts5yy_reduce_ofst[] = {

  203078.  /*     0 */   -16,   -8,    0,    9,   17,   25,   46,  -17,  -17,   37,

  203079.  /*    10 */    67,    4,    4,    8,    4,   20,   27,   38,

  203080. };

  203081. static const fts5YYACTIONTYPE fts5yy_default[] = {

  203082.  /*     0 */    80,   80,   80,   80,   80,   80,   95,   80,   80,  105,

  203083.  /*    10 */    80,  110,  110,   80,  110,  110,   80,   80,   80,   80,

  203084.  /*    20 */    80,   91,   80,   80,   80,  101,  100,   80,   80,   90,

  203085.  /*    30 */   103,   80,   80,  104,   80,

  203086. };

  203087. /********** End of lemon-generated parsing tables *****************************/

  203088. 

  203089. /* The next table maps tokens (terminal symbols) into fallback tokens.  

  203090. ** If a construct like the following:

  203091. ** 

  203092. **      %fallback ID X Y Z.

  203093. **

  203094. ** appears in the grammar, then ID becomes a fallback token for X, Y,

  203095. ** and Z.  Whenever one of the tokens X, Y, or Z is input to the parser

  203096. ** but it does not parse, the type of the token is changed to ID and

  203097. ** the parse is retried before an error is thrown.

  203098. **

  203099. ** This feature can be used, for example, to cause some keywords in a language

  203100. ** to revert to identifiers if they keyword does not apply in the context where

  203101. ** it appears.

  203102. */

  203103. #ifdef fts5YYFALLBACK

  203104. static const fts5YYCODETYPE fts5yyFallback[] = {

  203105. };

  203106. #endif /* fts5YYFALLBACK */

  203107. 

  203108. /* The following structure represents a single element of the

  203109. ** parser's stack.  Information stored includes:

  203110. **

  203111. **   +  The state number for the parser at this level of the stack.

  203112. **

  203113. **   +  The value of the token stored at this level of the stack.

  203114. **      (In other words, the "major" token.)

  203115. **

  203116. **   +  The semantic value stored at this level of the stack.  This is

  203117. **      the information used by the action routines in the grammar.

  203118. **      It is sometimes called the "minor" token.

  203119. **

  203120. ** After the "shift" half of a SHIFTREDUCE action, the stateno field

  203121. ** actually contains the reduce action for the second half of the

  203122. ** SHIFTREDUCE.

  203123. */

  203124. struct fts5yyStackEntry {

  203125.   fts5YYACTIONTYPE stateno;  /* The state-number, or reduce action in SHIFTREDUCE */

  203126.   fts5YYCODETYPE major;      /* The major token value.  This is the code

  203127.                          ** number for the token at this stack level */

  203128.   fts5YYMINORTYPE minor;     /* The user-supplied minor token value.  This

  203129.                          ** is the value of the token  */

  203130. };

  203131. typedef struct fts5yyStackEntry fts5yyStackEntry;

  203132. 

  203133. /* The state of the parser is completely contained in an instance of

  203134. ** the following structure */

  203135. struct fts5yyParser {

  203136.   fts5yyStackEntry *fts5yytos;          /* Pointer to top element of the stack */

  203137. #ifdef fts5YYTRACKMAXSTACKDEPTH

  203138.   int fts5yyhwm;                    /* High-water mark of the stack */

  203139. #endif

  203140. #ifndef fts5YYNOERRORRECOVERY

  203141.   int fts5yyerrcnt;                 /* Shifts left before out of the error */

  203142. #endif

  203143.   sqlite3Fts5ParserARG_SDECL                /* A place to hold %extra_argument */

  203144.   sqlite3Fts5ParserCTX_SDECL                /* A place to hold %extra_context */

  203145. #if fts5YYSTACKDEPTH<=0

  203146.   int fts5yystksz;                  /* Current side of the stack */

  203147.   fts5yyStackEntry *fts5yystack;        /* The parser's stack */

  203148.   fts5yyStackEntry fts5yystk0;          /* First stack entry */

  203149. #else

  203150.   fts5yyStackEntry fts5yystack[fts5YYSTACKDEPTH];  /* The parser's stack */

  203151.   fts5yyStackEntry *fts5yystackEnd;            /* Last entry in the stack */

  203152. #endif

  203153. };

  203154. typedef struct fts5yyParser fts5yyParser;

  203155. 

  203156. #ifndef NDEBUG

  203157. /* #include <stdio.h> */

  203158. static FILE *fts5yyTraceFILE = 0;

  203159. static char *fts5yyTracePrompt = 0;

  203160. #endif /* NDEBUG */

  203161. 

  203162. #ifndef NDEBUG

  203163. /* 

  203164. ** Turn parser tracing on by giving a stream to which to write the trace

  203165. ** and a prompt to preface each trace message.  Tracing is turned off

  203166. ** by making either argument NULL 

  203167. **

  203168. ** Inputs:

  203169. ** <ul>

  203170. ** <li> A FILE* to which trace output should be written.

  203171. **      If NULL, then tracing is turned off.

  203172. ** <li> A prefix string written at the beginning of every

  203173. **      line of trace output.  If NULL, then tracing is

  203174. **      turned off.

  203175. ** </ul>

  203176. **

  203177. ** Outputs:

  203178. ** None.

  203179. */

  203180. static void sqlite3Fts5ParserTrace(FILE *TraceFILE, char *zTracePrompt){

  203181.   fts5yyTraceFILE = TraceFILE;

  203182.   fts5yyTracePrompt = zTracePrompt;

  203183.   if( fts5yyTraceFILE==0 ) fts5yyTracePrompt = 0;

  203184.   else if( fts5yyTracePrompt==0 ) fts5yyTraceFILE = 0;

  203185. }

  203186. #endif /* NDEBUG */

  203187. 

  203188. #if defined(fts5YYCOVERAGE) || !defined(NDEBUG)

  203189. /* For tracing shifts, the names of all terminals and nonterminals

  203190. ** are required.  The following table supplies these names */

  203191. static const char *const fts5yyTokenName[] = { 

  203192.   /*    0 */ "$",

  203193.   /*    1 */ "OR",

  203194.   /*    2 */ "AND",

  203195.   /*    3 */ "NOT",

  203196.   /*    4 */ "TERM",

  203197.   /*    5 */ "COLON",

  203198.   /*    6 */ "MINUS",

  203199.   /*    7 */ "LCP",

  203200.   /*    8 */ "RCP",

  203201.   /*    9 */ "STRING",

  203202.   /*   10 */ "LP",

  203203.   /*   11 */ "RP",

  203204.   /*   12 */ "CARET",

  203205.   /*   13 */ "COMMA",

  203206.   /*   14 */ "PLUS",

  203207.   /*   15 */ "STAR",

  203208.   /*   16 */ "input",

  203209.   /*   17 */ "expr",

  203210.   /*   18 */ "cnearset",

  203211.   /*   19 */ "exprlist",

  203212.   /*   20 */ "colset",

  203213.   /*   21 */ "colsetlist",

  203214.   /*   22 */ "nearset",

  203215.   /*   23 */ "nearphrases",

  203216.   /*   24 */ "phrase",

  203217.   /*   25 */ "neardist_opt",

  203218.   /*   26 */ "star_opt",

  203219. };

  203220. #endif /* defined(fts5YYCOVERAGE) || !defined(NDEBUG) */

  203221. 

  203222. #ifndef NDEBUG

  203223. /* For tracing reduce actions, the names of all rules are required.

  203224. */

  203225. static const char *const fts5yyRuleName[] = {

  203226.  /*   0 */ "input ::= expr",

  203227.  /*   1 */ "colset ::= MINUS LCP colsetlist RCP",

  203228.  /*   2 */ "colset ::= LCP colsetlist RCP",

  203229.  /*   3 */ "colset ::= STRING",

  203230.  /*   4 */ "colset ::= MINUS STRING",

  203231.  /*   5 */ "colsetlist ::= colsetlist STRING",

  203232.  /*   6 */ "colsetlist ::= STRING",

  203233.  /*   7 */ "expr ::= expr AND expr",

  203234.  /*   8 */ "expr ::= expr OR expr",

  203235.  /*   9 */ "expr ::= expr NOT expr",

  203236.  /*  10 */ "expr ::= colset COLON LP expr RP",

  203237.  /*  11 */ "expr ::= LP expr RP",

  203238.  /*  12 */ "expr ::= exprlist",

  203239.  /*  13 */ "exprlist ::= cnearset",

  203240.  /*  14 */ "exprlist ::= exprlist cnearset",

  203241.  /*  15 */ "cnearset ::= nearset",

  203242.  /*  16 */ "cnearset ::= colset COLON nearset",

  203243.  /*  17 */ "nearset ::= phrase",

  203244.  /*  18 */ "nearset ::= CARET phrase",

  203245.  /*  19 */ "nearset ::= STRING LP nearphrases neardist_opt RP",

  203246.  /*  20 */ "nearphrases ::= phrase",

  203247.  /*  21 */ "nearphrases ::= nearphrases phrase",

  203248.  /*  22 */ "neardist_opt ::=",

  203249.  /*  23 */ "neardist_opt ::= COMMA STRING",

  203250.  /*  24 */ "phrase ::= phrase PLUS STRING star_opt",

  203251.  /*  25 */ "phrase ::= STRING star_opt",

  203252.  /*  26 */ "star_opt ::= STAR",

  203253.  /*  27 */ "star_opt ::=",

  203254. };

  203255. #endif /* NDEBUG */

  203256. 

  203257. 

  203258. #if fts5YYSTACKDEPTH<=0

  203259. /*

  203260. ** Try to increase the size of the parser stack.  Return the number

  203261. ** of errors.  Return 0 on success.

  203262. */

  203263. static int fts5yyGrowStack(fts5yyParser *p){

  203264.   int newSize;

  203265.   int idx;

  203266.   fts5yyStackEntry *pNew;

  203267. 

  203268.   newSize = p->fts5yystksz*2 + 100;

  203269.   idx = p->fts5yytos ? (int)(p->fts5yytos - p->fts5yystack) : 0;

  203270.   if( p->fts5yystack==&p->fts5yystk0 ){

  203271.     pNew = malloc(newSize*sizeof(pNew[0]));

  203272.     if( pNew ) pNew[0] = p->fts5yystk0;

  203273.   }else{

  203274.     pNew = realloc(p->fts5yystack, newSize*sizeof(pNew[0]));

  203275.   }

  203276.   if( pNew ){

  203277.     p->fts5yystack = pNew;

  203278.     p->fts5yytos = &p->fts5yystack[idx];

  203279. #ifndef NDEBUG

  203280.     if( fts5yyTraceFILE ){

  203281.       fprintf(fts5yyTraceFILE,"%sStack grows from %d to %d entries.\n",

  203282.               fts5yyTracePrompt, p->fts5yystksz, newSize);

  203283.     }

  203284. #endif

  203285.     p->fts5yystksz = newSize;

  203286.   }

  203287.   return pNew==0; 

  203288. }

  203289. #endif

  203290. 

  203291. /* Datatype of the argument to the memory allocated passed as the

  203292. ** second argument to sqlite3Fts5ParserAlloc() below.  This can be changed by

  203293. ** putting an appropriate #define in the %include section of the input

  203294. ** grammar.

  203295. */

  203296. #ifndef fts5YYMALLOCARGTYPE

  203297. # define fts5YYMALLOCARGTYPE size_t

  203298. #endif

  203299. 

  203300. /* Initialize a new parser that has already been allocated.

  203301. */

  203302. static void sqlite3Fts5ParserInit(void *fts5yypRawParser sqlite3Fts5ParserCTX_PDECL){

  203303.   fts5yyParser *fts5yypParser = (fts5yyParser*)fts5yypRawParser;

  203304.   sqlite3Fts5ParserCTX_STORE

  203305. #ifdef fts5YYTRACKMAXSTACKDEPTH

  203306.   fts5yypParser->fts5yyhwm = 0;

  203307. #endif

  203308. #if fts5YYSTACKDEPTH<=0

  203309.   fts5yypParser->fts5yytos = NULL;

  203310.   fts5yypParser->fts5yystack = NULL;

  203311.   fts5yypParser->fts5yystksz = 0;

  203312.   if( fts5yyGrowStack(fts5yypParser) ){

  203313.     fts5yypParser->fts5yystack = &fts5yypParser->fts5yystk0;

  203314.     fts5yypParser->fts5yystksz = 1;

  203315.   }

  203316. #endif

  203317. #ifndef fts5YYNOERRORRECOVERY

  203318.   fts5yypParser->fts5yyerrcnt = -1;

  203319. #endif

  203320.   fts5yypParser->fts5yytos = fts5yypParser->fts5yystack;

  203321.   fts5yypParser->fts5yystack[0].stateno = 0;

  203322.   fts5yypParser->fts5yystack[0].major = 0;

  203323. #if fts5YYSTACKDEPTH>0

  203324.   fts5yypParser->fts5yystackEnd = &fts5yypParser->fts5yystack[fts5YYSTACKDEPTH-1];

  203325. #endif

  203326. }

  203327. 

  203328. #ifndef sqlite3Fts5Parser_ENGINEALWAYSONSTACK

  203329. /* 

  203330. ** This function allocates a new parser.

  203331. ** The only argument is a pointer to a function which works like

  203332. ** malloc.

  203333. **

  203334. ** Inputs:

  203335. ** A pointer to the function used to allocate memory.

  203336. **

  203337. ** Outputs:

  203338. ** A pointer to a parser.  This pointer is used in subsequent calls

  203339. ** to sqlite3Fts5Parser and sqlite3Fts5ParserFree.

  203340. */

  203341. static void *sqlite3Fts5ParserAlloc(void *(*mallocProc)(fts5YYMALLOCARGTYPE) sqlite3Fts5ParserCTX_PDECL){

  203342.   fts5yyParser *fts5yypParser;

  203343.   fts5yypParser = (fts5yyParser*)(*mallocProc)( (fts5YYMALLOCARGTYPE)sizeof(fts5yyParser) );

  203344.   if( fts5yypParser ){

  203345.     sqlite3Fts5ParserCTX_STORE

  203346.     sqlite3Fts5ParserInit(fts5yypParser sqlite3Fts5ParserCTX_PARAM);

  203347.   }

  203348.   return (void*)fts5yypParser;

  203349. }

  203350. #endif /* sqlite3Fts5Parser_ENGINEALWAYSONSTACK */

  203351. 

  203352. 

  203353. /* The following function deletes the "minor type" or semantic value

  203354. ** associated with a symbol.  The symbol can be either a terminal

  203355. ** or nonterminal. "fts5yymajor" is the symbol code, and "fts5yypminor" is

  203356. ** a pointer to the value to be deleted.  The code used to do the 

  203357. ** deletions is derived from the %destructor and/or %token_destructor

  203358. ** directives of the input grammar.

  203359. */

  203360. static void fts5yy_destructor(

  203361.   fts5yyParser *fts5yypParser,    /* The parser */

  203362.   fts5YYCODETYPE fts5yymajor,     /* Type code for object to destroy */

  203363.   fts5YYMINORTYPE *fts5yypminor   /* The object to be destroyed */

  203364. ){

  203365.   sqlite3Fts5ParserARG_FETCH

  203366.   sqlite3Fts5ParserCTX_FETCH

  203367.   switch( fts5yymajor ){

  203368.     /* Here is inserted the actions which take place when a

  203369.     ** terminal or non-terminal is destroyed.  This can happen

  203370.     ** when the symbol is popped from the stack during a

  203371.     ** reduce or during error processing or when a parser is 

  203372.     ** being destroyed before it is finished parsing.

  203373.     **

  203374.     ** Note: during a reduce, the only symbols destroyed are those

  203375.     ** which appear on the RHS of the rule, but which are *not* used

  203376.     ** inside the C code.

  203377.     */

  203378. /********* Begin destructor definitions ***************************************/

  203379.     case 16: /* input */

  203380. {

  203381.  (void)pParse; 

  203382. }

  203383.       break;

  203384.     case 17: /* expr */

  203385.     case 18: /* cnearset */

  203386.     case 19: /* exprlist */

  203387. {

  203388.  sqlite3Fts5ParseNodeFree((fts5yypminor->fts5yy24)); 

  203389. }

  203390.       break;

  203391.     case 20: /* colset */

  203392.     case 21: /* colsetlist */

  203393. {

  203394.  sqlite3_free((fts5yypminor->fts5yy11)); 

  203395. }

  203396.       break;

  203397.     case 22: /* nearset */

  203398.     case 23: /* nearphrases */

  203399. {

  203400.  sqlite3Fts5ParseNearsetFree((fts5yypminor->fts5yy46)); 

  203401. }

  203402.       break;

  203403.     case 24: /* phrase */

  203404. {

  203405.  sqlite3Fts5ParsePhraseFree((fts5yypminor->fts5yy53)); 

  203406. }

  203407.       break;

  203408. /********* End destructor definitions *****************************************/

  203409.     default:  break;   /* If no destructor action specified: do nothing */

  203410.   }

  203411. }

  203412. 

  203413. /*

  203414. ** Pop the parser's stack once.

  203415. **

  203416. ** If there is a destructor routine associated with the token which

  203417. ** is popped from the stack, then call it.

  203418. */

  203419. static void fts5yy_pop_parser_stack(fts5yyParser *pParser){

  203420.   fts5yyStackEntry *fts5yytos;

  203421.   assert( pParser->fts5yytos!=0 );

  203422.   assert( pParser->fts5yytos > pParser->fts5yystack );

  203423.   fts5yytos = pParser->fts5yytos--;

  203424. #ifndef NDEBUG

  203425.   if( fts5yyTraceFILE ){

  203426.     fprintf(fts5yyTraceFILE,"%sPopping %s\n",

  203427.       fts5yyTracePrompt,

  203428.       fts5yyTokenName[fts5yytos->major]);

  203429.   }

  203430. #endif

  203431.   fts5yy_destructor(pParser, fts5yytos->major, &fts5yytos->minor);

  203432. }

  203433. 

  203434. /*

  203435. ** Clear all secondary memory allocations from the parser

  203436. */

  203437. static void sqlite3Fts5ParserFinalize(void *p){

  203438.   fts5yyParser *pParser = (fts5yyParser*)p;

  203439.   while( pParser->fts5yytos>pParser->fts5yystack ) fts5yy_pop_parser_stack(pParser);

  203440. #if fts5YYSTACKDEPTH<=0

  203441.   if( pParser->fts5yystack!=&pParser->fts5yystk0 ) free(pParser->fts5yystack);

  203442. #endif

  203443. }

  203444. 

  203445. #ifndef sqlite3Fts5Parser_ENGINEALWAYSONSTACK

  203446. /* 

  203447. ** Deallocate and destroy a parser.  Destructors are called for

  203448. ** all stack elements before shutting the parser down.

  203449. **

  203450. ** If the fts5YYPARSEFREENEVERNULL macro exists (for example because it

  203451. ** is defined in a %include section of the input grammar) then it is

  203452. ** assumed that the input pointer is never NULL.

  203453. */

  203454. static void sqlite3Fts5ParserFree(

  203455.   void *p,                    /* The parser to be deleted */

  203456.   void (*freeProc)(void*)     /* Function used to reclaim memory */

  203457. ){

  203458. #ifndef fts5YYPARSEFREENEVERNULL

  203459.   if( p==0 ) return;

  203460. #endif

  203461.   sqlite3Fts5ParserFinalize(p);

  203462.   (*freeProc)(p);

  203463. }

  203464. #endif /* sqlite3Fts5Parser_ENGINEALWAYSONSTACK */

  203465. 

  203466. /*

  203467. ** Return the peak depth of the stack for a parser.

  203468. */

  203469. #ifdef fts5YYTRACKMAXSTACKDEPTH

  203470. static int sqlite3Fts5ParserStackPeak(void *p){

  203471.   fts5yyParser *pParser = (fts5yyParser*)p;

  203472.   return pParser->fts5yyhwm;

  203473. }

  203474. #endif

  203475. 

  203476. /* This array of booleans keeps track of the parser statement

  203477. ** coverage.  The element fts5yycoverage[X][Y] is set when the parser

  203478. ** is in state X and has a lookahead token Y.  In a well-tested

  203479. ** systems, every element of this matrix should end up being set.

  203480. */

  203481. #if defined(fts5YYCOVERAGE)

  203482. static unsigned char fts5yycoverage[fts5YYNSTATE][fts5YYNFTS5TOKEN];

  203483. #endif

  203484. 

  203485. /*

  203486. ** Write into out a description of every state/lookahead combination that

  203487. **

  203488. **   (1)  has not been used by the parser, and

  203489. **   (2)  is not a syntax error.

  203490. **

  203491. ** Return the number of missed state/lookahead combinations.

  203492. */

  203493. #if defined(fts5YYCOVERAGE)

  203494. static int sqlite3Fts5ParserCoverage(FILE *out){

  203495.   int stateno, iLookAhead, i;

  203496.   int nMissed = 0;

  203497.   for(stateno=0; stateno<fts5YYNSTATE; stateno++){

  203498.     i = fts5yy_shift_ofst[stateno];

  203499.     for(iLookAhead=0; iLookAhead<fts5YYNFTS5TOKEN; iLookAhead++){

  203500.       if( fts5yy_lookahead[i+iLookAhead]!=iLookAhead ) continue;

  203501.       if( fts5yycoverage[stateno][iLookAhead]==0 ) nMissed++;

  203502.       if( out ){

  203503.         fprintf(out,"State %d lookahead %s %s\n", stateno,

  203504.                 fts5yyTokenName[iLookAhead],

  203505.                 fts5yycoverage[stateno][iLookAhead] ? "ok" : "missed");

  203506.       }

  203507.     }

  203508.   }

  203509.   return nMissed;

  203510. }

  203511. #endif

  203512. 

  203513. /*

  203514. ** Find the appropriate action for a parser given the terminal

  203515. ** look-ahead token iLookAhead.

  203516. */

  203517. static fts5YYACTIONTYPE fts5yy_find_shift_action(

  203518.   fts5YYCODETYPE iLookAhead,    /* The look-ahead token */

  203519.   fts5YYACTIONTYPE stateno      /* Current state number */

  203520. ){

  203521.   int i;

  203522. 

  203523.   if( stateno>fts5YY_MAX_SHIFT ) return stateno;

  203524.   assert( stateno <= fts5YY_SHIFT_COUNT );

  203525. #if defined(fts5YYCOVERAGE)

  203526.   fts5yycoverage[stateno][iLookAhead] = 1;

  203527. #endif

  203528.   do{

  203529.     i = fts5yy_shift_ofst[stateno];

  203530.     assert( i>=0 );

  203531.     /* assert( i+fts5YYNFTS5TOKEN<=(int)fts5YY_NLOOKAHEAD ); */

  203532.     assert( iLookAhead!=fts5YYNOCODE );

  203533.     assert( iLookAhead < fts5YYNFTS5TOKEN );

  203534.     i += iLookAhead;

  203535.     if( i>=fts5YY_NLOOKAHEAD || fts5yy_lookahead[i]!=iLookAhead ){

  203536. #ifdef fts5YYFALLBACK

  203537.       fts5YYCODETYPE iFallback;            /* Fallback token */

  203538.       if( iLookAhead<sizeof(fts5yyFallback)/sizeof(fts5yyFallback[0])

  203539.              && (iFallback = fts5yyFallback[iLookAhead])!=0 ){

  203540. #ifndef NDEBUG

  203541.         if( fts5yyTraceFILE ){

  203542.           fprintf(fts5yyTraceFILE, "%sFALLBACK %s => %s\n",

  203543.              fts5yyTracePrompt, fts5yyTokenName[iLookAhead], fts5yyTokenName[iFallback]);

  203544.         }

  203545. #endif

  203546.         assert( fts5yyFallback[iFallback]==0 ); /* Fallback loop must terminate */

  203547.         iLookAhead = iFallback;

  203548.         continue;

  203549.       }

  203550. #endif

  203551. #ifdef fts5YYWILDCARD

  203552.       {

  203553.         int j = i - iLookAhead + fts5YYWILDCARD;

  203554.         if( 

  203555. #if fts5YY_SHIFT_MIN+fts5YYWILDCARD<0

  203556.           j>=0 &&

  203557. #endif

  203558. #if fts5YY_SHIFT_MAX+fts5YYWILDCARD>=fts5YY_ACTTAB_COUNT

  203559.           j<fts5YY_ACTTAB_COUNT &&

  203560. #endif

  203561.           j<(int)(sizeof(fts5yy_lookahead)/sizeof(fts5yy_lookahead[0])) &&

  203562.           fts5yy_lookahead[j]==fts5YYWILDCARD && iLookAhead>0

  203563.         ){

  203564. #ifndef NDEBUG

  203565.           if( fts5yyTraceFILE ){

  203566.             fprintf(fts5yyTraceFILE, "%sWILDCARD %s => %s\n",

  203567.                fts5yyTracePrompt, fts5yyTokenName[iLookAhead],

  203568.                fts5yyTokenName[fts5YYWILDCARD]);

  203569.           }

  203570. #endif /* NDEBUG */

  203571.           return fts5yy_action[j];

  203572.         }

  203573.       }

  203574. #endif /* fts5YYWILDCARD */

  203575.       return fts5yy_default[stateno];

  203576.     }else{

  203577.       return fts5yy_action[i];

  203578.     }

  203579.   }while(1);

  203580. }

  203581. 

  203582. /*

  203583. ** Find the appropriate action for a parser given the non-terminal

  203584. ** look-ahead token iLookAhead.

  203585. */

  203586. static fts5YYACTIONTYPE fts5yy_find_reduce_action(

  203587.   fts5YYACTIONTYPE stateno,     /* Current state number */

  203588.   fts5YYCODETYPE iLookAhead     /* The look-ahead token */

  203589. ){

  203590.   int i;

  203591. #ifdef fts5YYERRORSYMBOL

  203592.   if( stateno>fts5YY_REDUCE_COUNT ){

  203593.     return fts5yy_default[stateno];

  203594.   }

  203595. #else

  203596.   assert( stateno<=fts5YY_REDUCE_COUNT );

  203597. #endif

  203598.   i = fts5yy_reduce_ofst[stateno];

  203599.   assert( iLookAhead!=fts5YYNOCODE );

  203600.   i += iLookAhead;

  203601. #ifdef fts5YYERRORSYMBOL

  203602.   if( i<0 || i>=fts5YY_ACTTAB_COUNT || fts5yy_lookahead[i]!=iLookAhead ){

  203603.     return fts5yy_default[stateno];

  203604.   }

  203605. #else

  203606.   assert( i>=0 && i<fts5YY_ACTTAB_COUNT );

  203607.   assert( fts5yy_lookahead[i]==iLookAhead );

  203608. #endif

  203609.   return fts5yy_action[i];

  203610. }

  203611. 

  203612. /*

  203613. ** The following routine is called if the stack overflows.

  203614. */

  203615. static void fts5yyStackOverflow(fts5yyParser *fts5yypParser){

  203616.    sqlite3Fts5ParserARG_FETCH

  203617.    sqlite3Fts5ParserCTX_FETCH

  203618. #ifndef NDEBUG

  203619.    if( fts5yyTraceFILE ){

  203620.      fprintf(fts5yyTraceFILE,"%sStack Overflow!\n",fts5yyTracePrompt);

  203621.    }

  203622. #endif

  203623.    while( fts5yypParser->fts5yytos>fts5yypParser->fts5yystack ) fts5yy_pop_parser_stack(fts5yypParser);

  203624.    /* Here code is inserted which will execute if the parser

  203625.    ** stack every overflows */

  203626. /******** Begin %stack_overflow code ******************************************/

  203627. 

  203628.   sqlite3Fts5ParseError(pParse, "fts5: parser stack overflow");

  203629. /******** End %stack_overflow code ********************************************/

  203630.    sqlite3Fts5ParserARG_STORE /* Suppress warning about unused %extra_argument var */

  203631.    sqlite3Fts5ParserCTX_STORE

  203632. }

  203633. 

  203634. /*

  203635. ** Print tracing information for a SHIFT action

  203636. */

  203637. #ifndef NDEBUG

  203638. static void fts5yyTraceShift(fts5yyParser *fts5yypParser, int fts5yyNewState, const char *zTag){

  203639.   if( fts5yyTraceFILE ){

  203640.     if( fts5yyNewState<fts5YYNSTATE ){

  203641.       fprintf(fts5yyTraceFILE,"%s%s '%s', go to state %d\n",

  203642.          fts5yyTracePrompt, zTag, fts5yyTokenName[fts5yypParser->fts5yytos->major],

  203643.          fts5yyNewState);

  203644.     }else{

  203645.       fprintf(fts5yyTraceFILE,"%s%s '%s', pending reduce %d\n",

  203646.          fts5yyTracePrompt, zTag, fts5yyTokenName[fts5yypParser->fts5yytos->major],

  203647.          fts5yyNewState - fts5YY_MIN_REDUCE);

  203648.     }

  203649.   }

  203650. }

  203651. #else

  203652. # define fts5yyTraceShift(X,Y,Z)

  203653. #endif

  203654. 

  203655. /*

  203656. ** Perform a shift action.

  203657. */

  203658. static void fts5yy_shift(

  203659.   fts5yyParser *fts5yypParser,          /* The parser to be shifted */

  203660.   fts5YYACTIONTYPE fts5yyNewState,      /* The new state to shift in */

  203661.   fts5YYCODETYPE fts5yyMajor,           /* The major token to shift in */

  203662.   sqlite3Fts5ParserFTS5TOKENTYPE fts5yyMinor        /* The minor token to shift in */

  203663. ){

  203664.   fts5yyStackEntry *fts5yytos;

  203665.   fts5yypParser->fts5yytos++;

  203666. #ifdef fts5YYTRACKMAXSTACKDEPTH

  203667.   if( (int)(fts5yypParser->fts5yytos - fts5yypParser->fts5yystack)>fts5yypParser->fts5yyhwm ){

  203668.     fts5yypParser->fts5yyhwm++;

  203669.     assert( fts5yypParser->fts5yyhwm == (int)(fts5yypParser->fts5yytos - fts5yypParser->fts5yystack) );

  203670.   }

  203671. #endif

  203672. #if fts5YYSTACKDEPTH>0 

  203673.   if( fts5yypParser->fts5yytos>fts5yypParser->fts5yystackEnd ){

  203674.     fts5yypParser->fts5yytos--;

  203675.     fts5yyStackOverflow(fts5yypParser);

  203676.     return;

  203677.   }

  203678. #else

  203679.   if( fts5yypParser->fts5yytos>=&fts5yypParser->fts5yystack[fts5yypParser->fts5yystksz] ){

  203680.     if( fts5yyGrowStack(fts5yypParser) ){

  203681.       fts5yypParser->fts5yytos--;

  203682.       fts5yyStackOverflow(fts5yypParser);

  203683.       return;

  203684.     }

  203685.   }

  203686. #endif

  203687.   if( fts5yyNewState > fts5YY_MAX_SHIFT ){

  203688.     fts5yyNewState += fts5YY_MIN_REDUCE - fts5YY_MIN_SHIFTREDUCE;

  203689.   }

  203690.   fts5yytos = fts5yypParser->fts5yytos;

  203691.   fts5yytos->stateno = fts5yyNewState;

  203692.   fts5yytos->major = fts5yyMajor;

  203693.   fts5yytos->minor.fts5yy0 = fts5yyMinor;

  203694.   fts5yyTraceShift(fts5yypParser, fts5yyNewState, "Shift");

  203695. }

  203696. 

  203697. /* For rule J, fts5yyRuleInfoLhs[J] contains the symbol on the left-hand side

  203698. ** of that rule */

  203699. static const fts5YYCODETYPE fts5yyRuleInfoLhs[] = {

  203700.     16,  /* (0) input ::= expr */

  203701.     20,  /* (1) colset ::= MINUS LCP colsetlist RCP */

  203702.     20,  /* (2) colset ::= LCP colsetlist RCP */

  203703.     20,  /* (3) colset ::= STRING */

  203704.     20,  /* (4) colset ::= MINUS STRING */

  203705.     21,  /* (5) colsetlist ::= colsetlist STRING */

  203706.     21,  /* (6) colsetlist ::= STRING */

  203707.     17,  /* (7) expr ::= expr AND expr */

  203708.     17,  /* (8) expr ::= expr OR expr */

  203709.     17,  /* (9) expr ::= expr NOT expr */

  203710.     17,  /* (10) expr ::= colset COLON LP expr RP */

  203711.     17,  /* (11) expr ::= LP expr RP */

  203712.     17,  /* (12) expr ::= exprlist */

  203713.     19,  /* (13) exprlist ::= cnearset */

  203714.     19,  /* (14) exprlist ::= exprlist cnearset */

  203715.     18,  /* (15) cnearset ::= nearset */

  203716.     18,  /* (16) cnearset ::= colset COLON nearset */

  203717.     22,  /* (17) nearset ::= phrase */

  203718.     22,  /* (18) nearset ::= CARET phrase */

  203719.     22,  /* (19) nearset ::= STRING LP nearphrases neardist_opt RP */

  203720.     23,  /* (20) nearphrases ::= phrase */

  203721.     23,  /* (21) nearphrases ::= nearphrases phrase */

  203722.     25,  /* (22) neardist_opt ::= */

  203723.     25,  /* (23) neardist_opt ::= COMMA STRING */

  203724.     24,  /* (24) phrase ::= phrase PLUS STRING star_opt */

  203725.     24,  /* (25) phrase ::= STRING star_opt */

  203726.     26,  /* (26) star_opt ::= STAR */

  203727.     26,  /* (27) star_opt ::= */

  203728. };

  203729. 

  203730. /* For rule J, fts5yyRuleInfoNRhs[J] contains the negative of the number

  203731. ** of symbols on the right-hand side of that rule. */

  203732. static const signed char fts5yyRuleInfoNRhs[] = {

  203733.    -1,  /* (0) input ::= expr */

  203734.    -4,  /* (1) colset ::= MINUS LCP colsetlist RCP */

  203735.    -3,  /* (2) colset ::= LCP colsetlist RCP */

  203736.    -1,  /* (3) colset ::= STRING */

  203737.    -2,  /* (4) colset ::= MINUS STRING */

  203738.    -2,  /* (5) colsetlist ::= colsetlist STRING */

  203739.    -1,  /* (6) colsetlist ::= STRING */

  203740.    -3,  /* (7) expr ::= expr AND expr */

  203741.    -3,  /* (8) expr ::= expr OR expr */

  203742.    -3,  /* (9) expr ::= expr NOT expr */

  203743.    -5,  /* (10) expr ::= colset COLON LP expr RP */

  203744.    -3,  /* (11) expr ::= LP expr RP */

  203745.    -1,  /* (12) expr ::= exprlist */

  203746.    -1,  /* (13) exprlist ::= cnearset */

  203747.    -2,  /* (14) exprlist ::= exprlist cnearset */

  203748.    -1,  /* (15) cnearset ::= nearset */

  203749.    -3,  /* (16) cnearset ::= colset COLON nearset */

  203750.    -1,  /* (17) nearset ::= phrase */

  203751.    -2,  /* (18) nearset ::= CARET phrase */

  203752.    -5,  /* (19) nearset ::= STRING LP nearphrases neardist_opt RP */

  203753.    -1,  /* (20) nearphrases ::= phrase */

  203754.    -2,  /* (21) nearphrases ::= nearphrases phrase */

  203755.     0,  /* (22) neardist_opt ::= */

  203756.    -2,  /* (23) neardist_opt ::= COMMA STRING */

  203757.    -4,  /* (24) phrase ::= phrase PLUS STRING star_opt */

  203758.    -2,  /* (25) phrase ::= STRING star_opt */

  203759.    -1,  /* (26) star_opt ::= STAR */

  203760.     0,  /* (27) star_opt ::= */

  203761. };

  203762. 

  203763. static void fts5yy_accept(fts5yyParser*);  /* Forward Declaration */

  203764. 

  203765. /*

  203766. ** Perform a reduce action and the shift that must immediately

  203767. ** follow the reduce.

  203768. **

  203769. ** The fts5yyLookahead and fts5yyLookaheadToken parameters provide reduce actions

  203770. ** access to the lookahead token (if any).  The fts5yyLookahead will be fts5YYNOCODE

  203771. ** if the lookahead token has already been consumed.  As this procedure is

  203772. ** only called from one place, optimizing compilers will in-line it, which

  203773. ** means that the extra parameters have no performance impact.

  203774. */

  203775. static fts5YYACTIONTYPE fts5yy_reduce(

  203776.   fts5yyParser *fts5yypParser,         /* The parser */

  203777.   unsigned int fts5yyruleno,       /* Number of the rule by which to reduce */

  203778.   int fts5yyLookahead,             /* Lookahead token, or fts5YYNOCODE if none */

  203779.   sqlite3Fts5ParserFTS5TOKENTYPE fts5yyLookaheadToken  /* Value of the lookahead token */

  203780.   sqlite3Fts5ParserCTX_PDECL                   /* %extra_context */

  203781. ){

  203782.   int fts5yygoto;                     /* The next state */

  203783.   fts5YYACTIONTYPE fts5yyact;             /* The next action */

  203784.   fts5yyStackEntry *fts5yymsp;            /* The top of the parser's stack */

  203785.   int fts5yysize;                     /* Amount to pop the stack */

  203786.   sqlite3Fts5ParserARG_FETCH

  203787.   (void)fts5yyLookahead;

  203788.   (void)fts5yyLookaheadToken;

  203789.   fts5yymsp = fts5yypParser->fts5yytos;

  203790. #ifndef NDEBUG

  203791.   if( fts5yyTraceFILE && fts5yyruleno<(int)(sizeof(fts5yyRuleName)/sizeof(fts5yyRuleName[0])) ){

  203792.     fts5yysize = fts5yyRuleInfoNRhs[fts5yyruleno];

  203793.     if( fts5yysize ){

  203794.       fprintf(fts5yyTraceFILE, "%sReduce %d [%s], go to state %d.\n",

  203795.         fts5yyTracePrompt,

  203796.         fts5yyruleno, fts5yyRuleName[fts5yyruleno], fts5yymsp[fts5yysize].stateno);

  203797.     }else{

  203798.       fprintf(fts5yyTraceFILE, "%sReduce %d [%s].\n",

  203799.         fts5yyTracePrompt, fts5yyruleno, fts5yyRuleName[fts5yyruleno]);

  203800.     }

  203801.   }

  203802. #endif /* NDEBUG */

  203803. 

  203804.   /* Check that the stack is large enough to grow by a single entry

  203805.   ** if the RHS of the rule is empty.  This ensures that there is room

  203806.   ** enough on the stack to push the LHS value */

  203807.   if( fts5yyRuleInfoNRhs[fts5yyruleno]==0 ){

  203808. #ifdef fts5YYTRACKMAXSTACKDEPTH

  203809.     if( (int)(fts5yypParser->fts5yytos - fts5yypParser->fts5yystack)>fts5yypParser->fts5yyhwm ){

  203810.       fts5yypParser->fts5yyhwm++;

  203811.       assert( fts5yypParser->fts5yyhwm == (int)(fts5yypParser->fts5yytos - fts5yypParser->fts5yystack));

  203812.     }

  203813. #endif

  203814. #if fts5YYSTACKDEPTH>0 

  203815.     if( fts5yypParser->fts5yytos>=fts5yypParser->fts5yystackEnd ){

  203816.       fts5yyStackOverflow(fts5yypParser);

  203817.       /* The call to fts5yyStackOverflow() above pops the stack until it is

  203818.       ** empty, causing the main parser loop to exit.  So the return value

  203819.       ** is never used and does not matter. */

  203820.       return 0;

  203821.     }

  203822. #else

  203823.     if( fts5yypParser->fts5yytos>=&fts5yypParser->fts5yystack[fts5yypParser->fts5yystksz-1] ){

  203824.       if( fts5yyGrowStack(fts5yypParser) ){

  203825.         fts5yyStackOverflow(fts5yypParser);

  203826.         /* The call to fts5yyStackOverflow() above pops the stack until it is

  203827.         ** empty, causing the main parser loop to exit.  So the return value

  203828.         ** is never used and does not matter. */

  203829.         return 0;

  203830.       }

  203831.       fts5yymsp = fts5yypParser->fts5yytos;

  203832.     }

  203833. #endif

  203834.   }

  203835. 

  203836.   switch( fts5yyruleno ){

  203837.   /* Beginning here are the reduction cases.  A typical example

  203838.   ** follows:

  203839.   **   case 0:

  203840.   **  #line <lineno> <grammarfile>

  203841.   **     { ... }           // User supplied code

  203842.   **  #line <lineno> <thisfile>

  203843.   **     break;

  203844.   */

  203845. /********** Begin reduce actions **********************************************/

  203846.         fts5YYMINORTYPE fts5yylhsminor;

  203847.       case 0: /* input ::= expr */

  203848. { sqlite3Fts5ParseFinished(pParse, fts5yymsp[0].minor.fts5yy24); }

  203849.         break;

  203850.       case 1: /* colset ::= MINUS LCP colsetlist RCP */

  203851. { 

  203852.     fts5yymsp[-3].minor.fts5yy11 = sqlite3Fts5ParseColsetInvert(pParse, fts5yymsp[-1].minor.fts5yy11);

  203853. }

  203854.         break;

  203855.       case 2: /* colset ::= LCP colsetlist RCP */

  203856. { fts5yymsp[-2].minor.fts5yy11 = fts5yymsp[-1].minor.fts5yy11; }

  203857.         break;

  203858.       case 3: /* colset ::= STRING */

  203859. {

  203860.   fts5yylhsminor.fts5yy11 = sqlite3Fts5ParseColset(pParse, 0, &fts5yymsp[0].minor.fts5yy0);

  203861. }

  203862.   fts5yymsp[0].minor.fts5yy11 = fts5yylhsminor.fts5yy11;

  203863.         break;

  203864.       case 4: /* colset ::= MINUS STRING */

  203865. {

  203866.   fts5yymsp[-1].minor.fts5yy11 = sqlite3Fts5ParseColset(pParse, 0, &fts5yymsp[0].minor.fts5yy0);

  203867.   fts5yymsp[-1].minor.fts5yy11 = sqlite3Fts5ParseColsetInvert(pParse, fts5yymsp[-1].minor.fts5yy11);

  203868. }

  203869.         break;

  203870.       case 5: /* colsetlist ::= colsetlist STRING */

  203871. { 

  203872.   fts5yylhsminor.fts5yy11 = sqlite3Fts5ParseColset(pParse, fts5yymsp[-1].minor.fts5yy11, &fts5yymsp[0].minor.fts5yy0); }

  203873.   fts5yymsp[-1].minor.fts5yy11 = fts5yylhsminor.fts5yy11;

  203874.         break;

  203875.       case 6: /* colsetlist ::= STRING */

  203876. { 

  203877.   fts5yylhsminor.fts5yy11 = sqlite3Fts5ParseColset(pParse, 0, &fts5yymsp[0].minor.fts5yy0); 

  203878. }

  203879.   fts5yymsp[0].minor.fts5yy11 = fts5yylhsminor.fts5yy11;

  203880.         break;

  203881.       case 7: /* expr ::= expr AND expr */

  203882. {

  203883.   fts5yylhsminor.fts5yy24 = sqlite3Fts5ParseNode(pParse, FTS5_AND, fts5yymsp[-2].minor.fts5yy24, fts5yymsp[0].minor.fts5yy24, 0);

  203884. }

  203885.   fts5yymsp[-2].minor.fts5yy24 = fts5yylhsminor.fts5yy24;

  203886.         break;

  203887.       case 8: /* expr ::= expr OR expr */

  203888. {

  203889.   fts5yylhsminor.fts5yy24 = sqlite3Fts5ParseNode(pParse, FTS5_OR, fts5yymsp[-2].minor.fts5yy24, fts5yymsp[0].minor.fts5yy24, 0);

  203890. }

  203891.   fts5yymsp[-2].minor.fts5yy24 = fts5yylhsminor.fts5yy24;

  203892.         break;

  203893.       case 9: /* expr ::= expr NOT expr */

  203894. {

  203895.   fts5yylhsminor.fts5yy24 = sqlite3Fts5ParseNode(pParse, FTS5_NOT, fts5yymsp[-2].minor.fts5yy24, fts5yymsp[0].minor.fts5yy24, 0);

  203896. }

  203897.   fts5yymsp[-2].minor.fts5yy24 = fts5yylhsminor.fts5yy24;

  203898.         break;

  203899.       case 10: /* expr ::= colset COLON LP expr RP */

  203900. {

  203901.   sqlite3Fts5ParseSetColset(pParse, fts5yymsp[-1].minor.fts5yy24, fts5yymsp[-4].minor.fts5yy11);

  203902.   fts5yylhsminor.fts5yy24 = fts5yymsp[-1].minor.fts5yy24;

  203903. }

  203904.   fts5yymsp[-4].minor.fts5yy24 = fts5yylhsminor.fts5yy24;

  203905.         break;

  203906.       case 11: /* expr ::= LP expr RP */

  203907. {fts5yymsp[-2].minor.fts5yy24 = fts5yymsp[-1].minor.fts5yy24;}

  203908.         break;

  203909.       case 12: /* expr ::= exprlist */

  203910.       case 13: /* exprlist ::= cnearset */ fts5yytestcase(fts5yyruleno==13);

  203911. {fts5yylhsminor.fts5yy24 = fts5yymsp[0].minor.fts5yy24;}

  203912.   fts5yymsp[0].minor.fts5yy24 = fts5yylhsminor.fts5yy24;

  203913.         break;

  203914.       case 14: /* exprlist ::= exprlist cnearset */

  203915. {

  203916.   fts5yylhsminor.fts5yy24 = sqlite3Fts5ParseImplicitAnd(pParse, fts5yymsp[-1].minor.fts5yy24, fts5yymsp[0].minor.fts5yy24);

  203917. }

  203918.   fts5yymsp[-1].minor.fts5yy24 = fts5yylhsminor.fts5yy24;

  203919.         break;

  203920.       case 15: /* cnearset ::= nearset */

  203921. { 

  203922.   fts5yylhsminor.fts5yy24 = sqlite3Fts5ParseNode(pParse, FTS5_STRING, 0, 0, fts5yymsp[0].minor.fts5yy46); 

  203923. }

  203924.   fts5yymsp[0].minor.fts5yy24 = fts5yylhsminor.fts5yy24;

  203925.         break;

  203926.       case 16: /* cnearset ::= colset COLON nearset */

  203927. { 

  203928.   fts5yylhsminor.fts5yy24 = sqlite3Fts5ParseNode(pParse, FTS5_STRING, 0, 0, fts5yymsp[0].minor.fts5yy46); 

  203929.   sqlite3Fts5ParseSetColset(pParse, fts5yylhsminor.fts5yy24, fts5yymsp[-2].minor.fts5yy11);

  203930. }

  203931.   fts5yymsp[-2].minor.fts5yy24 = fts5yylhsminor.fts5yy24;

  203932.         break;

  203933.       case 17: /* nearset ::= phrase */

  203934. { fts5yylhsminor.fts5yy46 = sqlite3Fts5ParseNearset(pParse, 0, fts5yymsp[0].minor.fts5yy53); }

  203935.   fts5yymsp[0].minor.fts5yy46 = fts5yylhsminor.fts5yy46;

  203936.         break;

  203937.       case 18: /* nearset ::= CARET phrase */

  203938. { 

  203939.   sqlite3Fts5ParseSetCaret(fts5yymsp[0].minor.fts5yy53);

  203940.   fts5yymsp[-1].minor.fts5yy46 = sqlite3Fts5ParseNearset(pParse, 0, fts5yymsp[0].minor.fts5yy53); 

  203941. }

  203942.         break;

  203943.       case 19: /* nearset ::= STRING LP nearphrases neardist_opt RP */

  203944. {

  203945.   sqlite3Fts5ParseNear(pParse, &fts5yymsp[-4].minor.fts5yy0);

  203946.   sqlite3Fts5ParseSetDistance(pParse, fts5yymsp[-2].minor.fts5yy46, &fts5yymsp[-1].minor.fts5yy0);

  203947.   fts5yylhsminor.fts5yy46 = fts5yymsp[-2].minor.fts5yy46;

  203948. }

  203949.   fts5yymsp[-4].minor.fts5yy46 = fts5yylhsminor.fts5yy46;

  203950.         break;

  203951.       case 20: /* nearphrases ::= phrase */

  203952. { 

  203953.   fts5yylhsminor.fts5yy46 = sqlite3Fts5ParseNearset(pParse, 0, fts5yymsp[0].minor.fts5yy53); 

  203954. }

  203955.   fts5yymsp[0].minor.fts5yy46 = fts5yylhsminor.fts5yy46;

  203956.         break;

  203957.       case 21: /* nearphrases ::= nearphrases phrase */

  203958. {

  203959.   fts5yylhsminor.fts5yy46 = sqlite3Fts5ParseNearset(pParse, fts5yymsp[-1].minor.fts5yy46, fts5yymsp[0].minor.fts5yy53);

  203960. }

  203961.   fts5yymsp[-1].minor.fts5yy46 = fts5yylhsminor.fts5yy46;

  203962.         break;

  203963.       case 22: /* neardist_opt ::= */

  203964. { fts5yymsp[1].minor.fts5yy0.p = 0; fts5yymsp[1].minor.fts5yy0.n = 0; }

  203965.         break;

  203966.       case 23: /* neardist_opt ::= COMMA STRING */

  203967. { fts5yymsp[-1].minor.fts5yy0 = fts5yymsp[0].minor.fts5yy0; }

  203968.         break;

  203969.       case 24: /* phrase ::= phrase PLUS STRING star_opt */

  203970. { 

  203971.   fts5yylhsminor.fts5yy53 = sqlite3Fts5ParseTerm(pParse, fts5yymsp[-3].minor.fts5yy53, &fts5yymsp[-1].minor.fts5yy0, fts5yymsp[0].minor.fts5yy4);

  203972. }

  203973.   fts5yymsp[-3].minor.fts5yy53 = fts5yylhsminor.fts5yy53;

  203974.         break;

  203975.       case 25: /* phrase ::= STRING star_opt */

  203976. { 

  203977.   fts5yylhsminor.fts5yy53 = sqlite3Fts5ParseTerm(pParse, 0, &fts5yymsp[-1].minor.fts5yy0, fts5yymsp[0].minor.fts5yy4);

  203978. }

  203979.   fts5yymsp[-1].minor.fts5yy53 = fts5yylhsminor.fts5yy53;

  203980.         break;

  203981.       case 26: /* star_opt ::= STAR */

  203982. { fts5yymsp[0].minor.fts5yy4 = 1; }

  203983.         break;

  203984.       case 27: /* star_opt ::= */

  203985. { fts5yymsp[1].minor.fts5yy4 = 0; }

  203986.         break;

  203987.       default:

  203988.         break;

  203989. /********** End reduce actions ************************************************/

  203990.   };

  203991.   assert( fts5yyruleno<sizeof(fts5yyRuleInfoLhs)/sizeof(fts5yyRuleInfoLhs[0]) );

  203992.   fts5yygoto = fts5yyRuleInfoLhs[fts5yyruleno];

  203993.   fts5yysize = fts5yyRuleInfoNRhs[fts5yyruleno];

  203994.   fts5yyact = fts5yy_find_reduce_action(fts5yymsp[fts5yysize].stateno,(fts5YYCODETYPE)fts5yygoto);

  203995. 

  203996.   /* There are no SHIFTREDUCE actions on nonterminals because the table

  203997.   ** generator has simplified them to pure REDUCE actions. */

  203998.   assert( !(fts5yyact>fts5YY_MAX_SHIFT && fts5yyact<=fts5YY_MAX_SHIFTREDUCE) );

  203999. 

  204000.   /* It is not possible for a REDUCE to be followed by an error */

  204001.   assert( fts5yyact!=fts5YY_ERROR_ACTION );

  204002. 

  204003.   fts5yymsp += fts5yysize+1;

  204004.   fts5yypParser->fts5yytos = fts5yymsp;

  204005.   fts5yymsp->stateno = (fts5YYACTIONTYPE)fts5yyact;

  204006.   fts5yymsp->major = (fts5YYCODETYPE)fts5yygoto;

  204007.   fts5yyTraceShift(fts5yypParser, fts5yyact, "... then shift");

  204008.   return fts5yyact;

  204009. }

  204010. 

  204011. /*

  204012. ** The following code executes when the parse fails

  204013. */

  204014. #ifndef fts5YYNOERRORRECOVERY

  204015. static void fts5yy_parse_failed(

  204016.   fts5yyParser *fts5yypParser           /* The parser */

  204017. ){

  204018.   sqlite3Fts5ParserARG_FETCH

  204019.   sqlite3Fts5ParserCTX_FETCH

  204020. #ifndef NDEBUG

  204021.   if( fts5yyTraceFILE ){

  204022.     fprintf(fts5yyTraceFILE,"%sFail!\n",fts5yyTracePrompt);

  204023.   }

  204024. #endif

  204025.   while( fts5yypParser->fts5yytos>fts5yypParser->fts5yystack ) fts5yy_pop_parser_stack(fts5yypParser);

  204026.   /* Here code is inserted which will be executed whenever the

  204027.   ** parser fails */

  204028. /************ Begin %parse_failure code ***************************************/

  204029. /************ End %parse_failure code *****************************************/

  204030.   sqlite3Fts5ParserARG_STORE /* Suppress warning about unused %extra_argument variable */

  204031.   sqlite3Fts5ParserCTX_STORE

  204032. }

  204033. #endif /* fts5YYNOERRORRECOVERY */

  204034. 

  204035. /*

  204036. ** The following code executes when a syntax error first occurs.

  204037. */

  204038. static void fts5yy_syntax_error(

  204039.   fts5yyParser *fts5yypParser,           /* The parser */

  204040.   int fts5yymajor,                   /* The major type of the error token */

  204041.   sqlite3Fts5ParserFTS5TOKENTYPE fts5yyminor         /* The minor type of the error token */

  204042. ){

  204043.   sqlite3Fts5ParserARG_FETCH

  204044.   sqlite3Fts5ParserCTX_FETCH

  204045. #define FTS5TOKEN fts5yyminor

  204046. /************ Begin %syntax_error code ****************************************/

  204047. 

  204048.   UNUSED_PARAM(fts5yymajor); /* Silence a compiler warning */

  204049.   sqlite3Fts5ParseError(

  204050.     pParse, "fts5: syntax error near \"%.*s\"",FTS5TOKEN.n,FTS5TOKEN.p

  204051.   );

  204052. /************ End %syntax_error code ******************************************/

  204053.   sqlite3Fts5ParserARG_STORE /* Suppress warning about unused %extra_argument variable */

  204054.   sqlite3Fts5ParserCTX_STORE

  204055. }

  204056. 

  204057. /*

  204058. ** The following is executed when the parser accepts

  204059. */

  204060. static void fts5yy_accept(

  204061.   fts5yyParser *fts5yypParser           /* The parser */

  204062. ){

  204063.   sqlite3Fts5ParserARG_FETCH

  204064.   sqlite3Fts5ParserCTX_FETCH

  204065. #ifndef NDEBUG

  204066.   if( fts5yyTraceFILE ){

  204067.     fprintf(fts5yyTraceFILE,"%sAccept!\n",fts5yyTracePrompt);

  204068.   }

  204069. #endif

  204070. #ifndef fts5YYNOERRORRECOVERY

  204071.   fts5yypParser->fts5yyerrcnt = -1;

  204072. #endif

  204073.   assert( fts5yypParser->fts5yytos==fts5yypParser->fts5yystack );

  204074.   /* Here code is inserted which will be executed whenever the

  204075.   ** parser accepts */

  204076. /*********** Begin %parse_accept code *****************************************/

  204077. /*********** End %parse_accept code *******************************************/

  204078.   sqlite3Fts5ParserARG_STORE /* Suppress warning about unused %extra_argument variable */

  204079.   sqlite3Fts5ParserCTX_STORE

  204080. }

  204081. 

  204082. /* The main parser program.

  204083. ** The first argument is a pointer to a structure obtained from

  204084. ** "sqlite3Fts5ParserAlloc" which describes the current state of the parser.

  204085. ** The second argument is the major token number.  The third is

  204086. ** the minor token.  The fourth optional argument is whatever the

  204087. ** user wants (and specified in the grammar) and is available for

  204088. ** use by the action routines.

  204089. **

  204090. ** Inputs:

  204091. ** <ul>

  204092. ** <li> A pointer to the parser (an opaque structure.)

  204093. ** <li> The major token number.

  204094. ** <li> The minor token number.

  204095. ** <li> An option argument of a grammar-specified type.

  204096. ** </ul>

  204097. **

  204098. ** Outputs:

  204099. ** None.

  204100. */

  204101. static void sqlite3Fts5Parser(

  204102.   void *fts5yyp,                   /* The parser */

  204103.   int fts5yymajor,                 /* The major token code number */

  204104.   sqlite3Fts5ParserFTS5TOKENTYPE fts5yyminor       /* The value for the token */

  204105.   sqlite3Fts5ParserARG_PDECL               /* Optional %extra_argument parameter */

  204106. ){

  204107.   fts5YYMINORTYPE fts5yyminorunion;

  204108.   fts5YYACTIONTYPE fts5yyact;   /* The parser action. */

  204109. #if !defined(fts5YYERRORSYMBOL) && !defined(fts5YYNOERRORRECOVERY)

  204110.   int fts5yyendofinput;     /* True if we are at the end of input */

  204111. #endif

  204112. #ifdef fts5YYERRORSYMBOL

  204113.   int fts5yyerrorhit = 0;   /* True if fts5yymajor has invoked an error */

  204114. #endif

  204115.   fts5yyParser *fts5yypParser = (fts5yyParser*)fts5yyp;  /* The parser */

  204116.   sqlite3Fts5ParserCTX_FETCH

  204117.   sqlite3Fts5ParserARG_STORE

  204118. 

  204119.   assert( fts5yypParser->fts5yytos!=0 );

  204120. #if !defined(fts5YYERRORSYMBOL) && !defined(fts5YYNOERRORRECOVERY)

  204121.   fts5yyendofinput = (fts5yymajor==0);

  204122. #endif

  204123. 

  204124.   fts5yyact = fts5yypParser->fts5yytos->stateno;

  204125. #ifndef NDEBUG

  204126.   if( fts5yyTraceFILE ){

  204127.     if( fts5yyact < fts5YY_MIN_REDUCE ){

  204128.       fprintf(fts5yyTraceFILE,"%sInput '%s' in state %d\n",

  204129.               fts5yyTracePrompt,fts5yyTokenName[fts5yymajor],fts5yyact);

  204130.     }else{

  204131.       fprintf(fts5yyTraceFILE,"%sInput '%s' with pending reduce %d\n",

  204132.               fts5yyTracePrompt,fts5yyTokenName[fts5yymajor],fts5yyact-fts5YY_MIN_REDUCE);

  204133.     }

  204134.   }

  204135. #endif

  204136. 

  204137.   do{

  204138.     assert( fts5yyact==fts5yypParser->fts5yytos->stateno );

  204139.     fts5yyact = fts5yy_find_shift_action((fts5YYCODETYPE)fts5yymajor,fts5yyact);

  204140.     if( fts5yyact >= fts5YY_MIN_REDUCE ){

  204141.       fts5yyact = fts5yy_reduce(fts5yypParser,fts5yyact-fts5YY_MIN_REDUCE,fts5yymajor,

  204142.                         fts5yyminor sqlite3Fts5ParserCTX_PARAM);

  204143.     }else if( fts5yyact <= fts5YY_MAX_SHIFTREDUCE ){

  204144.       fts5yy_shift(fts5yypParser,fts5yyact,(fts5YYCODETYPE)fts5yymajor,fts5yyminor);

  204145. #ifndef fts5YYNOERRORRECOVERY

  204146.       fts5yypParser->fts5yyerrcnt--;

  204147. #endif

  204148.       break;

  204149.     }else if( fts5yyact==fts5YY_ACCEPT_ACTION ){

  204150.       fts5yypParser->fts5yytos--;

  204151.       fts5yy_accept(fts5yypParser);

  204152.       return;

  204153.     }else{

  204154.       assert( fts5yyact == fts5YY_ERROR_ACTION );

  204155.       fts5yyminorunion.fts5yy0 = fts5yyminor;

  204156. #ifdef fts5YYERRORSYMBOL

  204157.       int fts5yymx;

  204158. #endif

  204159. #ifndef NDEBUG

  204160.       if( fts5yyTraceFILE ){

  204161.         fprintf(fts5yyTraceFILE,"%sSyntax Error!\n",fts5yyTracePrompt);

  204162.       }

  204163. #endif

  204164. #ifdef fts5YYERRORSYMBOL

  204165.       /* A syntax error has occurred.

  204166.       ** The response to an error depends upon whether or not the

  204167.       ** grammar defines an error token "ERROR".  

  204168.       **

  204169.       ** This is what we do if the grammar does define ERROR:

  204170.       **

  204171.       **  * Call the %syntax_error function.

  204172.       **

  204173.       **  * Begin popping the stack until we enter a state where

  204174.       **    it is legal to shift the error symbol, then shift

  204175.       **    the error symbol.

  204176.       **

  204177.       **  * Set the error count to three.

  204178.       **

  204179.       **  * Begin accepting and shifting new tokens.  No new error

  204180.       **    processing will occur until three tokens have been

  204181.       **    shifted successfully.

  204182.       **

  204183.       */

  204184.       if( fts5yypParser->fts5yyerrcnt<0 ){

  204185.         fts5yy_syntax_error(fts5yypParser,fts5yymajor,fts5yyminor);

  204186.       }

  204187.       fts5yymx = fts5yypParser->fts5yytos->major;

  204188.       if( fts5yymx==fts5YYERRORSYMBOL || fts5yyerrorhit ){

  204189. #ifndef NDEBUG

  204190.         if( fts5yyTraceFILE ){

  204191.           fprintf(fts5yyTraceFILE,"%sDiscard input token %s\n",

  204192.              fts5yyTracePrompt,fts5yyTokenName[fts5yymajor]);

  204193.         }

  204194. #endif

  204195.         fts5yy_destructor(fts5yypParser, (fts5YYCODETYPE)fts5yymajor, &fts5yyminorunion);

  204196.         fts5yymajor = fts5YYNOCODE;

  204197.       }else{

  204198.         while( fts5yypParser->fts5yytos >= fts5yypParser->fts5yystack

  204199.             && (fts5yyact = fts5yy_find_reduce_action(

  204200.                         fts5yypParser->fts5yytos->stateno,

  204201.                         fts5YYERRORSYMBOL)) > fts5YY_MAX_SHIFTREDUCE

  204202.         ){

  204203.           fts5yy_pop_parser_stack(fts5yypParser);

  204204.         }

  204205.         if( fts5yypParser->fts5yytos < fts5yypParser->fts5yystack || fts5yymajor==0 ){

  204206.           fts5yy_destructor(fts5yypParser,(fts5YYCODETYPE)fts5yymajor,&fts5yyminorunion);

  204207.           fts5yy_parse_failed(fts5yypParser);

  204208. #ifndef fts5YYNOERRORRECOVERY

  204209.           fts5yypParser->fts5yyerrcnt = -1;

  204210. #endif

  204211.           fts5yymajor = fts5YYNOCODE;

  204212.         }else if( fts5yymx!=fts5YYERRORSYMBOL ){

  204213.           fts5yy_shift(fts5yypParser,fts5yyact,fts5YYERRORSYMBOL,fts5yyminor);

  204214.         }

  204215.       }

  204216.       fts5yypParser->fts5yyerrcnt = 3;

  204217.       fts5yyerrorhit = 1;

  204218.       if( fts5yymajor==fts5YYNOCODE ) break;

  204219.       fts5yyact = fts5yypParser->fts5yytos->stateno;

  204220. #elif defined(fts5YYNOERRORRECOVERY)

  204221.       /* If the fts5YYNOERRORRECOVERY macro is defined, then do not attempt to

  204222.       ** do any kind of error recovery.  Instead, simply invoke the syntax

  204223.       ** error routine and continue going as if nothing had happened.

  204224.       **

  204225.       ** Applications can set this macro (for example inside %include) if

  204226.       ** they intend to abandon the parse upon the first syntax error seen.

  204227.       */

  204228.       fts5yy_syntax_error(fts5yypParser,fts5yymajor, fts5yyminor);

  204229.       fts5yy_destructor(fts5yypParser,(fts5YYCODETYPE)fts5yymajor,&fts5yyminorunion);

  204230.       break;

  204231. #else  /* fts5YYERRORSYMBOL is not defined */

  204232.       /* This is what we do if the grammar does not define ERROR:

  204233.       **

  204234.       **  * Report an error message, and throw away the input token.

  204235.       **

  204236.       **  * If the input token is $, then fail the parse.

  204237.       **

  204238.       ** As before, subsequent error messages are suppressed until

  204239.       ** three input tokens have been successfully shifted.

  204240.       */

  204241.       if( fts5yypParser->fts5yyerrcnt<=0 ){

  204242.         fts5yy_syntax_error(fts5yypParser,fts5yymajor, fts5yyminor);

  204243.       }

  204244.       fts5yypParser->fts5yyerrcnt = 3;

  204245.       fts5yy_destructor(fts5yypParser,(fts5YYCODETYPE)fts5yymajor,&fts5yyminorunion);

  204246.       if( fts5yyendofinput ){

  204247.         fts5yy_parse_failed(fts5yypParser);

  204248. #ifndef fts5YYNOERRORRECOVERY

  204249.         fts5yypParser->fts5yyerrcnt = -1;

  204250. #endif

  204251.       }

  204252.       break;

  204253. #endif

  204254.     }

  204255.   }while( fts5yypParser->fts5yytos>fts5yypParser->fts5yystack );

  204256. #ifndef NDEBUG

  204257.   if( fts5yyTraceFILE ){

  204258.     fts5yyStackEntry *i;

  204259.     char cDiv = '[';

  204260.     fprintf(fts5yyTraceFILE,"%sReturn. Stack=",fts5yyTracePrompt);

  204261.     for(i=&fts5yypParser->fts5yystack[1]; i<=fts5yypParser->fts5yytos; i++){

  204262.       fprintf(fts5yyTraceFILE,"%c%s", cDiv, fts5yyTokenName[i->major]);

  204263.       cDiv = ' ';

  204264.     }

  204265.     fprintf(fts5yyTraceFILE,"]\n");

  204266.   }

  204267. #endif

  204268.   return;

  204269. }

  204270. 

  204271. /*

  204272. ** Return the fallback token corresponding to canonical token iToken, or

  204273. ** 0 if iToken has no fallback.

  204274. */

  204275. static int sqlite3Fts5ParserFallback(int iToken){

  204276. #ifdef fts5YYFALLBACK

  204277.   if( iToken<(int)(sizeof(fts5yyFallback)/sizeof(fts5yyFallback[0])) ){

  204278.     return fts5yyFallback[iToken];

  204279.   }

  204280. #else

  204281.   (void)iToken;

  204282. #endif

  204283.   return 0;

  204284. }

  204285. 

  204286. /*

  204287. ** 2014 May 31

  204288. **

  204289. ** The author disclaims copyright to this source code.  In place of

  204290. ** a legal notice, here is a blessing:

  204291. **

  204292. **    May you do good and not evil.

  204293. **    May you find forgiveness for yourself and forgive others.

  204294. **    May you share freely, never taking more than you give.

  204295. **

  204296. ******************************************************************************

  204297. */

  204298. 

  204299. 

  204300. /* #include "fts5Int.h" */

  204301. #include <math.h>                 /* amalgamator: keep */

  204302. 

  204303. /*

  204304. ** Object used to iterate through all "coalesced phrase instances" in 

  204305. ** a single column of the current row. If the phrase instances in the

  204306. ** column being considered do not overlap, this object simply iterates

  204307. ** through them. Or, if they do overlap (share one or more tokens in

  204308. ** common), each set of overlapping instances is treated as a single

  204309. ** match. See documentation for the highlight() auxiliary function for

  204310. ** details.

  204311. **

  204312. ** Usage is:

  204313. **

  204314. **   for(rc = fts5CInstIterNext(pApi, pFts, iCol, &iter);

  204315. **      (rc==SQLITE_OK && 0==fts5CInstIterEof(&iter);

  204316. **      rc = fts5CInstIterNext(&iter)

  204317. **   ){

  204318. **     printf("instance starts at %d, ends at %d\n", iter.iStart, iter.iEnd);

  204319. **   }

  204320. **

  204321. */

  204322. typedef struct CInstIter CInstIter;

  204323. struct CInstIter {

  204324.   const Fts5ExtensionApi *pApi;   /* API offered by current FTS version */

  204325.   Fts5Context *pFts;              /* First arg to pass to pApi functions */

  204326.   int iCol;                       /* Column to search */

  204327.   int iInst;                      /* Next phrase instance index */

  204328.   int nInst;                      /* Total number of phrase instances */

  204329. 

  204330.   /* Output variables */

  204331.   int iStart;                     /* First token in coalesced phrase instance */

  204332.   int iEnd;                       /* Last token in coalesced phrase instance */

  204333. };

  204334. 

  204335. /*

  204336. ** Advance the iterator to the next coalesced phrase instance. Return

  204337. ** an SQLite error code if an error occurs, or SQLITE_OK otherwise.

  204338. */

  204339. static int fts5CInstIterNext(CInstIter *pIter){

  204340.   int rc = SQLITE_OK;

  204341.   pIter->iStart = -1;

  204342.   pIter->iEnd = -1;

  204343. 

  204344.   while( rc==SQLITE_OK && pIter->iInst<pIter->nInst ){

  204345.     int ip; int ic; int io;

  204346.     rc = pIter->pApi->xInst(pIter->pFts, pIter->iInst, &ip, &ic, &io);

  204347.     if( rc==SQLITE_OK ){

  204348.       if( ic==pIter->iCol ){

  204349.         int iEnd = io - 1 + pIter->pApi->xPhraseSize(pIter->pFts, ip);

  204350.         if( pIter->iStart<0 ){

  204351.           pIter->iStart = io;

  204352.           pIter->iEnd = iEnd;

  204353.         }else if( io<=pIter->iEnd ){

  204354.           if( iEnd>pIter->iEnd ) pIter->iEnd = iEnd;

  204355.         }else{

  204356.           break;

  204357.         }

  204358.       }

  204359.       pIter->iInst++;

  204360.     }

  204361.   }

  204362. 

  204363.   return rc;

  204364. }

  204365. 

  204366. /*

  204367. ** Initialize the iterator object indicated by the final parameter to 

  204368. ** iterate through coalesced phrase instances in column iCol.

  204369. */

  204370. static int fts5CInstIterInit(

  204371.   const Fts5ExtensionApi *pApi,

  204372.   Fts5Context *pFts,

  204373.   int iCol,

  204374.   CInstIter *pIter

  204375. ){

  204376.   int rc;

  204377. 

  204378.   memset(pIter, 0, sizeof(CInstIter));

  204379.   pIter->pApi = pApi;

  204380.   pIter->pFts = pFts;

  204381.   pIter->iCol = iCol;

  204382.   rc = pApi->xInstCount(pFts, &pIter->nInst);

  204383. 

  204384.   if( rc==SQLITE_OK ){

  204385.     rc = fts5CInstIterNext(pIter);

  204386.   }

  204387. 

  204388.   return rc;

  204389. }

  204390. 

  204391. 

  204392. 

  204393. /*************************************************************************

  204394. ** Start of highlight() implementation.

  204395. */

  204396. typedef struct HighlightContext HighlightContext;

  204397. struct HighlightContext {

  204398.   CInstIter iter;                 /* Coalesced Instance Iterator */

  204399.   int iPos;                       /* Current token offset in zIn[] */

  204400.   int iRangeStart;                /* First token to include */

  204401.   int iRangeEnd;                  /* If non-zero, last token to include */

  204402.   const char *zOpen;              /* Opening highlight */

  204403.   const char *zClose;             /* Closing highlight */

  204404.   const char *zIn;                /* Input text */

  204405.   int nIn;                        /* Size of input text in bytes */

  204406.   int iOff;                       /* Current offset within zIn[] */

  204407.   char *zOut;                     /* Output value */

  204408. };

  204409. 

  204410. /*

  204411. ** Append text to the HighlightContext output string - p->zOut. Argument

  204412. ** z points to a buffer containing n bytes of text to append. If n is 

  204413. ** negative, everything up until the first '\0' is appended to the output.

  204414. **

  204415. ** If *pRc is set to any value other than SQLITE_OK when this function is 

  204416. ** called, it is a no-op. If an error (i.e. an OOM condition) is encountered, 

  204417. ** *pRc is set to an error code before returning. 

  204418. */

  204419. static void fts5HighlightAppend(

  204420.   int *pRc, 

  204421.   HighlightContext *p, 

  204422.   const char *z, int n

  204423. ){

  204424.   if( *pRc==SQLITE_OK && z ){

  204425.     if( n<0 ) n = (int)strlen(z);

  204426.     p->zOut = sqlite3_mprintf("%z%.*s", p->zOut, n, z);

  204427.     if( p->zOut==0 ) *pRc = SQLITE_NOMEM;

  204428.   }

  204429. }

  204430. 

  204431. /*

  204432. ** Tokenizer callback used by implementation of highlight() function.

  204433. */

  204434. static int fts5HighlightCb(

  204435.   void *pContext,                 /* Pointer to HighlightContext object */

  204436.   int tflags,                     /* Mask of FTS5_TOKEN_* flags */

  204437.   const char *pToken,             /* Buffer containing token */

  204438.   int nToken,                     /* Size of token in bytes */

  204439.   int iStartOff,                  /* Start offset of token */

  204440.   int iEndOff                     /* End offset of token */

  204441. ){

  204442.   HighlightContext *p = (HighlightContext*)pContext;

  204443.   int rc = SQLITE_OK;

  204444.   int iPos;

  204445. 

  204446.   UNUSED_PARAM2(pToken, nToken);

  204447. 

  204448.   if( tflags & FTS5_TOKEN_COLOCATED ) return SQLITE_OK;

  204449.   iPos = p->iPos++;

  204450. 

  204451.   if( p->iRangeEnd>0 ){

  204452.     if( iPos<p->iRangeStart || iPos>p->iRangeEnd ) return SQLITE_OK;

  204453.     if( p->iRangeStart && iPos==p->iRangeStart ) p->iOff = iStartOff;

  204454.   }

  204455. 

  204456.   if( iPos==p->iter.iStart ){

  204457.     fts5HighlightAppend(&rc, p, &p->zIn[p->iOff], iStartOff - p->iOff);

  204458.     fts5HighlightAppend(&rc, p, p->zOpen, -1);

  204459.     p->iOff = iStartOff;

  204460.   }

  204461. 

  204462.   if( iPos==p->iter.iEnd ){

  204463.     if( p->iRangeEnd && p->iter.iStart<p->iRangeStart ){

  204464.       fts5HighlightAppend(&rc, p, p->zOpen, -1);

  204465.     }

  204466.     fts5HighlightAppend(&rc, p, &p->zIn[p->iOff], iEndOff - p->iOff);

  204467.     fts5HighlightAppend(&rc, p, p->zClose, -1);

  204468.     p->iOff = iEndOff;

  204469.     if( rc==SQLITE_OK ){

  204470.       rc = fts5CInstIterNext(&p->iter);

  204471.     }

  204472.   }

  204473. 

  204474.   if( p->iRangeEnd>0 && iPos==p->iRangeEnd ){

  204475.     fts5HighlightAppend(&rc, p, &p->zIn[p->iOff], iEndOff - p->iOff);

  204476.     p->iOff = iEndOff;

  204477.     if( iPos>=p->iter.iStart && iPos<p->iter.iEnd ){

  204478.       fts5HighlightAppend(&rc, p, p->zClose, -1);

  204479.     }

  204480.   }

  204481. 

  204482.   return rc;

  204483. }

  204484. 

  204485. /*

  204486. ** Implementation of highlight() function.

  204487. */

  204488. static void fts5HighlightFunction(

  204489.   const Fts5ExtensionApi *pApi,   /* API offered by current FTS version */

  204490.   Fts5Context *pFts,              /* First arg to pass to pApi functions */

  204491.   sqlite3_context *pCtx,          /* Context for returning result/error */

  204492.   int nVal,                       /* Number of values in apVal[] array */

  204493.   sqlite3_value **apVal           /* Array of trailing arguments */

  204494. ){

  204495.   HighlightContext ctx;

  204496.   int rc;

  204497.   int iCol;

  204498. 

  204499.   if( nVal!=3 ){

  204500.     const char *zErr = "wrong number of arguments to function highlight()";

  204501.     sqlite3_result_error(pCtx, zErr, -1);

  204502.     return;

  204503.   }

  204504. 

  204505.   iCol = sqlite3_value_int(apVal[0]);

  204506.   memset(&ctx, 0, sizeof(HighlightContext));

  204507.   ctx.zOpen = (const char*)sqlite3_value_text(apVal[1]);

  204508.   ctx.zClose = (const char*)sqlite3_value_text(apVal[2]);

  204509.   rc = pApi->xColumnText(pFts, iCol, &ctx.zIn, &ctx.nIn);

  204510. 

  204511.   if( ctx.zIn ){

  204512.     if( rc==SQLITE_OK ){

  204513.       rc = fts5CInstIterInit(pApi, pFts, iCol, &ctx.iter);

  204514.     }

  204515. 

  204516.     if( rc==SQLITE_OK ){

  204517.       rc = pApi->xTokenize(pFts, ctx.zIn, ctx.nIn, (void*)&ctx,fts5HighlightCb);

  204518.     }

  204519.     fts5HighlightAppend(&rc, &ctx, &ctx.zIn[ctx.iOff], ctx.nIn - ctx.iOff);

  204520. 

  204521.     if( rc==SQLITE_OK ){

  204522.       sqlite3_result_text(pCtx, (const char*)ctx.zOut, -1, SQLITE_TRANSIENT);

  204523.     }

  204524.     sqlite3_free(ctx.zOut);

  204525.   }

  204526.   if( rc!=SQLITE_OK ){

  204527.     sqlite3_result_error_code(pCtx, rc);

  204528.   }

  204529. }

  204530. /*

  204531. ** End of highlight() implementation.

  204532. **************************************************************************/

  204533. 

  204534. /*

  204535. ** Context object passed to the fts5SentenceFinderCb() function.

  204536. */

  204537. typedef struct Fts5SFinder Fts5SFinder;

  204538. struct Fts5SFinder {

  204539.   int iPos;                       /* Current token position */

  204540.   int nFirstAlloc;                /* Allocated size of aFirst[] */

  204541.   int nFirst;                     /* Number of entries in aFirst[] */

  204542.   int *aFirst;                    /* Array of first token in each sentence */

  204543.   const char *zDoc;               /* Document being tokenized */

  204544. };

  204545. 

  204546. /*

  204547. ** Add an entry to the Fts5SFinder.aFirst[] array. Grow the array if

  204548. ** necessary. Return SQLITE_OK if successful, or SQLITE_NOMEM if an

  204549. ** error occurs.

  204550. */

  204551. static int fts5SentenceFinderAdd(Fts5SFinder *p, int iAdd){

  204552.   if( p->nFirstAlloc==p->nFirst ){

  204553.     int nNew = p->nFirstAlloc ? p->nFirstAlloc*2 : 64;

  204554.     int *aNew;

  204555. 

  204556.     aNew = (int*)sqlite3_realloc64(p->aFirst, nNew*sizeof(int));

  204557.     if( aNew==0 ) return SQLITE_NOMEM;

  204558.     p->aFirst = aNew;

  204559.     p->nFirstAlloc = nNew;

  204560.   }

  204561.   p->aFirst[p->nFirst++] = iAdd;

  204562.   return SQLITE_OK;

  204563. }

  204564. 

  204565. /*

  204566. ** This function is an xTokenize() callback used by the auxiliary snippet()

  204567. ** function. Its job is to identify tokens that are the first in a sentence.

  204568. ** For each such token, an entry is added to the SFinder.aFirst[] array.

  204569. */

  204570. static int fts5SentenceFinderCb(

  204571.   void *pContext,                 /* Pointer to HighlightContext object */

  204572.   int tflags,                     /* Mask of FTS5_TOKEN_* flags */

  204573.   const char *pToken,             /* Buffer containing token */

  204574.   int nToken,                     /* Size of token in bytes */

  204575.   int iStartOff,                  /* Start offset of token */

  204576.   int iEndOff                     /* End offset of token */

  204577. ){

  204578.   int rc = SQLITE_OK;

  204579. 

  204580.   UNUSED_PARAM2(pToken, nToken);

  204581.   UNUSED_PARAM(iEndOff);

  204582. 

  204583.   if( (tflags & FTS5_TOKEN_COLOCATED)==0 ){

  204584.     Fts5SFinder *p = (Fts5SFinder*)pContext;

  204585.     if( p->iPos>0 ){

  204586.       int i;

  204587.       char c = 0;

  204588.       for(i=iStartOff-1; i>=0; i--){

  204589.         c = p->zDoc[i];

  204590.         if( c!=' ' && c!='\t' && c!='\n' && c!='\r' ) break;

  204591.       }

  204592.       if( i!=iStartOff-1 && (c=='.' || c==':') ){

  204593.         rc = fts5SentenceFinderAdd(p, p->iPos);

  204594.       }

  204595.     }else{

  204596.       rc = fts5SentenceFinderAdd(p, 0);

  204597.     }

  204598.     p->iPos++;

  204599.   }

  204600.   return rc;

  204601. }

  204602. 

  204603. static int fts5SnippetScore(

  204604.   const Fts5ExtensionApi *pApi,   /* API offered by current FTS version */

  204605.   Fts5Context *pFts,              /* First arg to pass to pApi functions */

  204606.   int nDocsize,                   /* Size of column in tokens */

  204607.   unsigned char *aSeen,           /* Array with one element per query phrase */

  204608.   int iCol,                       /* Column to score */

  204609.   int iPos,                       /* Starting offset to score */

  204610.   int nToken,                     /* Max tokens per snippet */

  204611.   int *pnScore,                   /* OUT: Score */

  204612.   int *piPos                      /* OUT: Adjusted offset */

  204613. ){

  204614.   int rc;

  204615.   int i;

  204616.   int ip = 0;

  204617.   int ic = 0;

  204618.   int iOff = 0;

  204619.   int iFirst = -1;

  204620.   int nInst;

  204621.   int nScore = 0;

  204622.   int iLast = 0;

  204623.   sqlite3_int64 iEnd = (sqlite3_int64)iPos + nToken;

  204624. 

  204625.   rc = pApi->xInstCount(pFts, &nInst);

  204626.   for(i=0; i<nInst && rc==SQLITE_OK; i++){

  204627.     rc = pApi->xInst(pFts, i, &ip, &ic, &iOff);

  204628.     if( rc==SQLITE_OK && ic==iCol && iOff>=iPos && iOff<iEnd ){

  204629.       nScore += (aSeen[ip] ? 1 : 1000);

  204630.       aSeen[ip] = 1;

  204631.       if( iFirst<0 ) iFirst = iOff;

  204632.       iLast = iOff + pApi->xPhraseSize(pFts, ip);

  204633.     }

  204634.   }

  204635. 

  204636.   *pnScore = nScore;

  204637.   if( piPos ){

  204638.     sqlite3_int64 iAdj = iFirst - (nToken - (iLast-iFirst)) / 2;

  204639.     if( (iAdj+nToken)>nDocsize ) iAdj = nDocsize - nToken;

  204640.     if( iAdj<0 ) iAdj = 0;

  204641.     *piPos = (int)iAdj;

  204642.   }

  204643. 

  204644.   return rc;

  204645. }

  204646. 

  204647. /*

  204648. ** Return the value in pVal interpreted as utf-8 text. Except, if pVal 

  204649. ** contains a NULL value, return a pointer to a static string zero

  204650. ** bytes in length instead of a NULL pointer.

  204651. */

  204652. static const char *fts5ValueToText(sqlite3_value *pVal){

  204653.   const char *zRet = (const char*)sqlite3_value_text(pVal);

  204654.   return zRet ? zRet : "";

  204655. }

  204656. 

  204657. /*

  204658. ** Implementation of snippet() function.

  204659. */

  204660. static void fts5SnippetFunction(

  204661.   const Fts5ExtensionApi *pApi,   /* API offered by current FTS version */

  204662.   Fts5Context *pFts,              /* First arg to pass to pApi functions */

  204663.   sqlite3_context *pCtx,          /* Context for returning result/error */

  204664.   int nVal,                       /* Number of values in apVal[] array */

  204665.   sqlite3_value **apVal           /* Array of trailing arguments */

  204666. ){

  204667.   HighlightContext ctx;

  204668.   int rc = SQLITE_OK;             /* Return code */

  204669.   int iCol;                       /* 1st argument to snippet() */

  204670.   const char *zEllips;            /* 4th argument to snippet() */

  204671.   int nToken;                     /* 5th argument to snippet() */

  204672.   int nInst = 0;                  /* Number of instance matches this row */

  204673.   int i;                          /* Used to iterate through instances */

  204674.   int nPhrase;                    /* Number of phrases in query */

  204675.   unsigned char *aSeen;           /* Array of "seen instance" flags */

  204676.   int iBestCol;                   /* Column containing best snippet */

  204677.   int iBestStart = 0;             /* First token of best snippet */

  204678.   int nBestScore = 0;             /* Score of best snippet */

  204679.   int nColSize = 0;               /* Total size of iBestCol in tokens */

  204680.   Fts5SFinder sFinder;            /* Used to find the beginnings of sentences */

  204681.   int nCol;

  204682. 

  204683.   if( nVal!=5 ){

  204684.     const char *zErr = "wrong number of arguments to function snippet()";

  204685.     sqlite3_result_error(pCtx, zErr, -1);

  204686.     return;

  204687.   }

  204688. 

  204689.   nCol = pApi->xColumnCount(pFts);

  204690.   memset(&ctx, 0, sizeof(HighlightContext));

  204691.   iCol = sqlite3_value_int(apVal[0]);

  204692.   ctx.zOpen = fts5ValueToText(apVal[1]);

  204693.   ctx.zClose = fts5ValueToText(apVal[2]);

  204694.   zEllips = fts5ValueToText(apVal[3]);

  204695.   nToken = sqlite3_value_int(apVal[4]);

  204696. 

  204697.   iBestCol = (iCol>=0 ? iCol : 0);

  204698.   nPhrase = pApi->xPhraseCount(pFts);

  204699.   aSeen = sqlite3_malloc(nPhrase);

  204700.   if( aSeen==0 ){

  204701.     rc = SQLITE_NOMEM;

  204702.   }

  204703.   if( rc==SQLITE_OK ){

  204704.     rc = pApi->xInstCount(pFts, &nInst);

  204705.   }

  204706. 

  204707.   memset(&sFinder, 0, sizeof(Fts5SFinder));

  204708.   for(i=0; i<nCol; i++){

  204709.     if( iCol<0 || iCol==i ){

  204710.       int nDoc;

  204711.       int nDocsize;

  204712.       int ii;

  204713.       sFinder.iPos = 0;

  204714.       sFinder.nFirst = 0;

  204715.       rc = pApi->xColumnText(pFts, i, &sFinder.zDoc, &nDoc);

  204716.       if( rc!=SQLITE_OK ) break;

  204717.       rc = pApi->xTokenize(pFts, 

  204718.           sFinder.zDoc, nDoc, (void*)&sFinder,fts5SentenceFinderCb

  204719.       );

  204720.       if( rc!=SQLITE_OK ) break;

  204721.       rc = pApi->xColumnSize(pFts, i, &nDocsize);

  204722.       if( rc!=SQLITE_OK ) break;

  204723. 

  204724.       for(ii=0; rc==SQLITE_OK && ii<nInst; ii++){

  204725.         int ip, ic, io;

  204726.         int iAdj;

  204727.         int nScore;

  204728.         int jj;

  204729. 

  204730.         rc = pApi->xInst(pFts, ii, &ip, &ic, &io);

  204731.         if( ic!=i ) continue;

  204732.         if( io>nDocsize ) rc = FTS5_CORRUPT;

  204733.         if( rc!=SQLITE_OK ) continue;

  204734.         memset(aSeen, 0, nPhrase);

  204735.         rc = fts5SnippetScore(pApi, pFts, nDocsize, aSeen, i,

  204736.             io, nToken, &nScore, &iAdj

  204737.         );

  204738.         if( rc==SQLITE_OK && nScore>nBestScore ){

  204739.           nBestScore = nScore;

  204740.           iBestCol = i;

  204741.           iBestStart = iAdj;

  204742.           nColSize = nDocsize;

  204743.         }

  204744. 

  204745.         if( rc==SQLITE_OK && sFinder.nFirst && nDocsize>nToken ){

  204746.           for(jj=0; jj<(sFinder.nFirst-1); jj++){

  204747.             if( sFinder.aFirst[jj+1]>io ) break;

  204748.           }

  204749. 

  204750.           if( sFinder.aFirst[jj]<io ){

  204751.             memset(aSeen, 0, nPhrase);

  204752.             rc = fts5SnippetScore(pApi, pFts, nDocsize, aSeen, i, 

  204753.               sFinder.aFirst[jj], nToken, &nScore, 0

  204754.             );

  204755. 

  204756.             nScore += (sFinder.aFirst[jj]==0 ? 120 : 100);

  204757.             if( rc==SQLITE_OK && nScore>nBestScore ){

  204758.               nBestScore = nScore;

  204759.               iBestCol = i;

  204760.               iBestStart = sFinder.aFirst[jj];

  204761.               nColSize = nDocsize;

  204762.             }

  204763.           }

  204764.         }

  204765.       }

  204766.     }

  204767.   }

  204768. 

  204769.   if( rc==SQLITE_OK ){

  204770.     rc = pApi->xColumnText(pFts, iBestCol, &ctx.zIn, &ctx.nIn);

  204771.   }

  204772.   if( rc==SQLITE_OK && nColSize==0 ){

  204773.     rc = pApi->xColumnSize(pFts, iBestCol, &nColSize);

  204774.   }

  204775.   if( ctx.zIn ){

  204776.     if( rc==SQLITE_OK ){

  204777.       rc = fts5CInstIterInit(pApi, pFts, iBestCol, &ctx.iter);

  204778.     }

  204779. 

  204780.     ctx.iRangeStart = iBestStart;

  204781.     ctx.iRangeEnd = iBestStart + nToken - 1;

  204782. 

  204783.     if( iBestStart>0 ){

  204784.       fts5HighlightAppend(&rc, &ctx, zEllips, -1);

  204785.     }

  204786. 

  204787.     /* Advance iterator ctx.iter so that it points to the first coalesced

  204788.     ** phrase instance at or following position iBestStart. */

  204789.     while( ctx.iter.iStart>=0 && ctx.iter.iStart<iBestStart && rc==SQLITE_OK ){

  204790.       rc = fts5CInstIterNext(&ctx.iter);

  204791.     }

  204792. 

  204793.     if( rc==SQLITE_OK ){

  204794.       rc = pApi->xTokenize(pFts, ctx.zIn, ctx.nIn, (void*)&ctx,fts5HighlightCb);

  204795.     }

  204796.     if( ctx.iRangeEnd>=(nColSize-1) ){

  204797.       fts5HighlightAppend(&rc, &ctx, &ctx.zIn[ctx.iOff], ctx.nIn - ctx.iOff);

  204798.     }else{

  204799.       fts5HighlightAppend(&rc, &ctx, zEllips, -1);

  204800.     }

  204801.   }

  204802.   if( rc==SQLITE_OK ){

  204803.     sqlite3_result_text(pCtx, (const char*)ctx.zOut, -1, SQLITE_TRANSIENT);

  204804.   }else{

  204805.     sqlite3_result_error_code(pCtx, rc);

  204806.   }

  204807.   sqlite3_free(ctx.zOut);

  204808.   sqlite3_free(aSeen);

  204809.   sqlite3_free(sFinder.aFirst);

  204810. }

  204811. 

  204812. /************************************************************************/

  204813. 

  204814. /*

  204815. ** The first time the bm25() function is called for a query, an instance

  204816. ** of the following structure is allocated and populated.

  204817. */

  204818. typedef struct Fts5Bm25Data Fts5Bm25Data;

  204819. struct Fts5Bm25Data {

  204820.   int nPhrase;                    /* Number of phrases in query */

  204821.   double avgdl;                   /* Average number of tokens in each row */

  204822.   double *aIDF;                   /* IDF for each phrase */

  204823.   double *aFreq;                  /* Array used to calculate phrase freq. */

  204824. };

  204825. 

  204826. /*

  204827. ** Callback used by fts5Bm25GetData() to count the number of rows in the

  204828. ** table matched by each individual phrase within the query.

  204829. */

  204830. static int fts5CountCb(

  204831.   const Fts5ExtensionApi *pApi, 

  204832.   Fts5Context *pFts,

  204833.   void *pUserData                 /* Pointer to sqlite3_int64 variable */

  204834. ){

  204835.   sqlite3_int64 *pn = (sqlite3_int64*)pUserData;

  204836.   UNUSED_PARAM2(pApi, pFts);

  204837.   (*pn)++;

  204838.   return SQLITE_OK;

  204839. }

  204840. 

  204841. /*

  204842. ** Set *ppData to point to the Fts5Bm25Data object for the current query. 

  204843. ** If the object has not already been allocated, allocate and populate it

  204844. ** now.

  204845. */

  204846. static int fts5Bm25GetData(

  204847.   const Fts5ExtensionApi *pApi, 

  204848.   Fts5Context *pFts,

  204849.   Fts5Bm25Data **ppData           /* OUT: bm25-data object for this query */

  204850. ){

  204851.   int rc = SQLITE_OK;             /* Return code */

  204852.   Fts5Bm25Data *p;                /* Object to return */

  204853. 

  204854.   p = pApi->xGetAuxdata(pFts, 0);

  204855.   if( p==0 ){

  204856.     int nPhrase;                  /* Number of phrases in query */

  204857.     sqlite3_int64 nRow = 0;       /* Number of rows in table */

  204858.     sqlite3_int64 nToken = 0;     /* Number of tokens in table */

  204859.     sqlite3_int64 nByte;          /* Bytes of space to allocate */

  204860.     int i;

  204861. 

  204862.     /* Allocate the Fts5Bm25Data object */

  204863.     nPhrase = pApi->xPhraseCount(pFts);

  204864.     nByte = sizeof(Fts5Bm25Data) + nPhrase*2*sizeof(double);

  204865.     p = (Fts5Bm25Data*)sqlite3_malloc64(nByte);

  204866.     if( p==0 ){

  204867.       rc = SQLITE_NOMEM;

  204868.     }else{

  204869.       memset(p, 0, (size_t)nByte);

  204870.       p->nPhrase = nPhrase;

  204871.       p->aIDF = (double*)&p[1];

  204872.       p->aFreq = &p->aIDF[nPhrase];

  204873.     }

  204874. 

  204875.     /* Calculate the average document length for this FTS5 table */

  204876.     if( rc==SQLITE_OK ) rc = pApi->xRowCount(pFts, &nRow);

  204877.     assert( rc!=SQLITE_OK || nRow>0 );

  204878.     if( rc==SQLITE_OK ) rc = pApi->xColumnTotalSize(pFts, -1, &nToken);

  204879.     if( rc==SQLITE_OK ) p->avgdl = (double)nToken  / (double)nRow;

  204880. 

  204881.     /* Calculate an IDF for each phrase in the query */

  204882.     for(i=0; rc==SQLITE_OK && i<nPhrase; i++){

  204883.       sqlite3_int64 nHit = 0;

  204884.       rc = pApi->xQueryPhrase(pFts, i, (void*)&nHit, fts5CountCb);

  204885.       if( rc==SQLITE_OK ){

  204886.         /* Calculate the IDF (Inverse Document Frequency) for phrase i.

  204887.         ** This is done using the standard BM25 formula as found on wikipedia:

  204888.         **

  204889.         **   IDF = log( (N - nHit + 0.5) / (nHit + 0.5) )

  204890.         **

  204891.         ** where "N" is the total number of documents in the set and nHit

  204892.         ** is the number that contain at least one instance of the phrase

  204893.         ** under consideration.

  204894.         **

  204895.         ** The problem with this is that if (N < 2*nHit), the IDF is 

  204896.         ** negative. Which is undesirable. So the mimimum allowable IDF is

  204897.         ** (1e-6) - roughly the same as a term that appears in just over

  204898.         ** half of set of 5,000,000 documents.  */

  204899.         double idf = log( (nRow - nHit + 0.5) / (nHit + 0.5) );

  204900.         if( idf<=0.0 ) idf = 1e-6;

  204901.         p->aIDF[i] = idf;

  204902.       }

  204903.     }

  204904. 

  204905.     if( rc!=SQLITE_OK ){

  204906.       sqlite3_free(p);

  204907.     }else{

  204908.       rc = pApi->xSetAuxdata(pFts, p, sqlite3_free);

  204909.     }

  204910.     if( rc!=SQLITE_OK ) p = 0;

  204911.   }

  204912.   *ppData = p;

  204913.   return rc;

  204914. }

  204915. 

  204916. /*

  204917. ** Implementation of bm25() function.

  204918. */

  204919. static void fts5Bm25Function(

  204920.   const Fts5ExtensionApi *pApi,   /* API offered by current FTS version */

  204921.   Fts5Context *pFts,              /* First arg to pass to pApi functions */

  204922.   sqlite3_context *pCtx,          /* Context for returning result/error */

  204923.   int nVal,                       /* Number of values in apVal[] array */

  204924.   sqlite3_value **apVal           /* Array of trailing arguments */

  204925. ){

  204926.   const double k1 = 1.2;          /* Constant "k1" from BM25 formula */

  204927.   const double b = 0.75;          /* Constant "b" from BM25 formula */

  204928.   int rc = SQLITE_OK;             /* Error code */

  204929.   double score = 0.0;             /* SQL function return value */

  204930.   Fts5Bm25Data *pData;            /* Values allocated/calculated once only */

  204931.   int i;                          /* Iterator variable */

  204932.   int nInst = 0;                  /* Value returned by xInstCount() */

  204933.   double D = 0.0;                 /* Total number of tokens in row */

  204934.   double *aFreq = 0;              /* Array of phrase freq. for current row */

  204935. 

  204936.   /* Calculate the phrase frequency (symbol "f(qi,D)" in the documentation)

  204937.   ** for each phrase in the query for the current row. */

  204938.   rc = fts5Bm25GetData(pApi, pFts, &pData);

  204939.   if( rc==SQLITE_OK ){

  204940.     aFreq = pData->aFreq;

  204941.     memset(aFreq, 0, sizeof(double) * pData->nPhrase);

  204942.     rc = pApi->xInstCount(pFts, &nInst);

  204943.   }

  204944.   for(i=0; rc==SQLITE_OK && i<nInst; i++){

  204945.     int ip; int ic; int io;

  204946.     rc = pApi->xInst(pFts, i, &ip, &ic, &io);

  204947.     if( rc==SQLITE_OK ){

  204948.       double w = (nVal > ic) ? sqlite3_value_double(apVal[ic]) : 1.0;

  204949.       aFreq[ip] += w;

  204950.     }

  204951.   }

  204952. 

  204953.   /* Figure out the total size of the current row in tokens. */

  204954.   if( rc==SQLITE_OK ){

  204955.     int nTok;

  204956.     rc = pApi->xColumnSize(pFts, -1, &nTok);

  204957.     D = (double)nTok;

  204958.   }

  204959. 

  204960.   /* Determine the BM25 score for the current row. */

  204961.   for(i=0; rc==SQLITE_OK && i<pData->nPhrase; i++){

  204962.     score += pData->aIDF[i] * (

  204963.       ( aFreq[i] * (k1 + 1.0) ) / 

  204964.       ( aFreq[i] + k1 * (1 - b + b * D / pData->avgdl) )

  204965.     );

  204966.   }

  204967.   

  204968.   /* If no error has occurred, return the calculated score. Otherwise,

  204969.   ** throw an SQL exception.  */

  204970.   if( rc==SQLITE_OK ){

  204971.     sqlite3_result_double(pCtx, -1.0 * score);

  204972.   }else{

  204973.     sqlite3_result_error_code(pCtx, rc);

  204974.   }

  204975. }

  204976. 

  204977. static int sqlite3Fts5AuxInit(fts5_api *pApi){

  204978.   struct Builtin {

  204979.     const char *zFunc;            /* Function name (nul-terminated) */

  204980.     void *pUserData;              /* User-data pointer */

  204981.     fts5_extension_function xFunc;/* Callback function */

  204982.     void (*xDestroy)(void*);      /* Destructor function */

  204983.   } aBuiltin [] = {

  204984.     { "snippet",   0, fts5SnippetFunction, 0 },

  204985.     { "highlight", 0, fts5HighlightFunction, 0 },

  204986.     { "bm25",      0, fts5Bm25Function,    0 },

  204987.   };

  204988.   int rc = SQLITE_OK;             /* Return code */

  204989.   int i;                          /* To iterate through builtin functions */

  204990. 

  204991.   for(i=0; rc==SQLITE_OK && i<ArraySize(aBuiltin); i++){

  204992.     rc = pApi->xCreateFunction(pApi,

  204993.         aBuiltin[i].zFunc,

  204994.         aBuiltin[i].pUserData,

  204995.         aBuiltin[i].xFunc,

  204996.         aBuiltin[i].xDestroy

  204997.     );

  204998.   }

  204999. 

  205000.   return rc;

  205001. }

  205002. 

  205003. /*

  205004. ** 2014 May 31

  205005. **

  205006. ** The author disclaims copyright to this source code.  In place of

  205007. ** a legal notice, here is a blessing:

  205008. **

  205009. **    May you do good and not evil.

  205010. **    May you find forgiveness for yourself and forgive others.

  205011. **    May you share freely, never taking more than you give.

  205012. **

  205013. ******************************************************************************

  205014. */

  205015. 

  205016. 

  205017. 

  205018. /* #include "fts5Int.h" */

  205019. 

  205020. static int sqlite3Fts5BufferSize(int *pRc, Fts5Buffer *pBuf, u32 nByte){

  205021.   if( (u32)pBuf->nSpace<nByte ){

  205022.     u64 nNew = pBuf->nSpace ? pBuf->nSpace : 64;

  205023.     u8 *pNew;

  205024.     while( nNew<nByte ){

  205025.       nNew = nNew * 2;

  205026.     }

  205027.     pNew = sqlite3_realloc64(pBuf->p, nNew);

  205028.     if( pNew==0 ){

  205029.       *pRc = SQLITE_NOMEM;

  205030.       return 1;

  205031.     }else{

  205032.       pBuf->nSpace = (int)nNew;

  205033.       pBuf->p = pNew;

  205034.     }

  205035.   }

  205036.   return 0;

  205037. }

  205038. 

  205039. 

  205040. /*

  205041. ** Encode value iVal as an SQLite varint and append it to the buffer object

  205042. ** pBuf. If an OOM error occurs, set the error code in p.

  205043. */

  205044. static void sqlite3Fts5BufferAppendVarint(int *pRc, Fts5Buffer *pBuf, i64 iVal){

  205045.   if( fts5BufferGrow(pRc, pBuf, 9) ) return;

  205046.   pBuf->n += sqlite3Fts5PutVarint(&pBuf->p[pBuf->n], iVal);

  205047. }

  205048. 

  205049. static void sqlite3Fts5Put32(u8 *aBuf, int iVal){

  205050.   aBuf[0] = (iVal>>24) & 0x00FF;

  205051.   aBuf[1] = (iVal>>16) & 0x00FF;

  205052.   aBuf[2] = (iVal>> 8) & 0x00FF;

  205053.   aBuf[3] = (iVal>> 0) & 0x00FF;

  205054. }

  205055. 

  205056. static int sqlite3Fts5Get32(const u8 *aBuf){

  205057.   return (int)((((u32)aBuf[0])<<24) + (aBuf[1]<<16) + (aBuf[2]<<8) + aBuf[3]);

  205058. }

  205059. 

  205060. /*

  205061. ** Append buffer nData/pData to buffer pBuf. If an OOM error occurs, set 

  205062. ** the error code in p. If an error has already occurred when this function

  205063. ** is called, it is a no-op.

  205064. */

  205065. static void sqlite3Fts5BufferAppendBlob(

  205066.   int *pRc,

  205067.   Fts5Buffer *pBuf, 

  205068.   u32 nData, 

  205069.   const u8 *pData

  205070. ){

  205071.   assert_nc( *pRc || nData>=0 );

  205072.   if( nData ){

  205073.     if( fts5BufferGrow(pRc, pBuf, nData) ) return;

  205074.     memcpy(&pBuf->p[pBuf->n], pData, nData);

  205075.     pBuf->n += nData;

  205076.   }

  205077. }

  205078. 

  205079. /*

  205080. ** Append the nul-terminated string zStr to the buffer pBuf. This function

  205081. ** ensures that the byte following the buffer data is set to 0x00, even 

  205082. ** though this byte is not included in the pBuf->n count.

  205083. */

  205084. static void sqlite3Fts5BufferAppendString(

  205085.   int *pRc,

  205086.   Fts5Buffer *pBuf, 

  205087.   const char *zStr

  205088. ){

  205089.   int nStr = (int)strlen(zStr);

  205090.   sqlite3Fts5BufferAppendBlob(pRc, pBuf, nStr+1, (const u8*)zStr);

  205091.   pBuf->n--;

  205092. }

  205093. 

  205094. /*

  205095. ** Argument zFmt is a printf() style format string. This function performs

  205096. ** the printf() style processing, then appends the results to buffer pBuf.

  205097. **

  205098. ** Like sqlite3Fts5BufferAppendString(), this function ensures that the byte 

  205099. ** following the buffer data is set to 0x00, even though this byte is not

  205100. ** included in the pBuf->n count.

  205101. */ 

  205102. static void sqlite3Fts5BufferAppendPrintf(

  205103.   int *pRc,

  205104.   Fts5Buffer *pBuf, 

  205105.   char *zFmt, ...

  205106. ){

  205107.   if( *pRc==SQLITE_OK ){

  205108.     char *zTmp;

  205109.     va_list ap;

  205110.     va_start(ap, zFmt);

  205111.     zTmp = sqlite3_vmprintf(zFmt, ap);

  205112.     va_end(ap);

  205113. 

  205114.     if( zTmp==0 ){

  205115.       *pRc = SQLITE_NOMEM;

  205116.     }else{

  205117.       sqlite3Fts5BufferAppendString(pRc, pBuf, zTmp);

  205118.       sqlite3_free(zTmp);

  205119.     }

  205120.   }

  205121. }

  205122. 

  205123. static char *sqlite3Fts5Mprintf(int *pRc, const char *zFmt, ...){

  205124.   char *zRet = 0;

  205125.   if( *pRc==SQLITE_OK ){

  205126.     va_list ap;

  205127.     va_start(ap, zFmt);

  205128.     zRet = sqlite3_vmprintf(zFmt, ap);

  205129.     va_end(ap);

  205130.     if( zRet==0 ){

  205131.       *pRc = SQLITE_NOMEM; 

  205132.     }

  205133.   }

  205134.   return zRet;

  205135. }

  205136.  

  205137. 

  205138. /*

  205139. ** Free any buffer allocated by pBuf. Zero the structure before returning.

  205140. */

  205141. static void sqlite3Fts5BufferFree(Fts5Buffer *pBuf){

  205142.   sqlite3_free(pBuf->p);

  205143.   memset(pBuf, 0, sizeof(Fts5Buffer));

  205144. }

  205145. 

  205146. /*

  205147. ** Zero the contents of the buffer object. But do not free the associated 

  205148. ** memory allocation.

  205149. */

  205150. static void sqlite3Fts5BufferZero(Fts5Buffer *pBuf){

  205151.   pBuf->n = 0;

  205152. }

  205153. 

  205154. /*

  205155. ** Set the buffer to contain nData/pData. If an OOM error occurs, leave an

  205156. ** the error code in p. If an error has already occurred when this function

  205157. ** is called, it is a no-op.

  205158. */

  205159. static void sqlite3Fts5BufferSet(

  205160.   int *pRc,

  205161.   Fts5Buffer *pBuf, 

  205162.   int nData, 

  205163.   const u8 *pData

  205164. ){

  205165.   pBuf->n = 0;

  205166.   sqlite3Fts5BufferAppendBlob(pRc, pBuf, nData, pData);

  205167. }

  205168. 

  205169. static int sqlite3Fts5PoslistNext64(

  205170.   const u8 *a, int n,             /* Buffer containing poslist */

  205171.   int *pi,                        /* IN/OUT: Offset within a[] */

  205172.   i64 *piOff                      /* IN/OUT: Current offset */

  205173. ){

  205174.   int i = *pi;

  205175.   if( i>=n ){

  205176.     /* EOF */

  205177.     *piOff = -1;

  205178.     return 1;  

  205179.   }else{

  205180.     i64 iOff = *piOff;

  205181.     int iVal;

  205182.     fts5FastGetVarint32(a, i, iVal);

  205183.     if( iVal<=1 ){

  205184.       if( iVal==0 ){

  205185.         *pi = i;

  205186.         return 0;

  205187.       }

  205188.       fts5FastGetVarint32(a, i, iVal);

  205189.       iOff = ((i64)iVal) << 32;

  205190.       fts5FastGetVarint32(a, i, iVal);

  205191.       if( iVal<2 ){

  205192.         /* This is a corrupt record. So stop parsing it here. */

  205193.         *piOff = -1;

  205194.         return 1;

  205195.       }

  205196.     }

  205197.     *piOff = iOff + ((iVal-2) & 0x7FFFFFFF);

  205198.     *pi = i;

  205199.     return 0;

  205200.   }

  205201. }

  205202. 

  205203. 

  205204. /*

  205205. ** Advance the iterator object passed as the only argument. Return true

  205206. ** if the iterator reaches EOF, or false otherwise.

  205207. */

  205208. static int sqlite3Fts5PoslistReaderNext(Fts5PoslistReader *pIter){

  205209.   if( sqlite3Fts5PoslistNext64(pIter->a, pIter->n, &pIter->i, &pIter->iPos) ){

  205210.     pIter->bEof = 1;

  205211.   }

  205212.   return pIter->bEof;

  205213. }

  205214. 

  205215. static int sqlite3Fts5PoslistReaderInit(

  205216.   const u8 *a, int n,             /* Poslist buffer to iterate through */

  205217.   Fts5PoslistReader *pIter        /* Iterator object to initialize */

  205218. ){

  205219.   memset(pIter, 0, sizeof(*pIter));

  205220.   pIter->a = a;

  205221.   pIter->n = n;

  205222.   sqlite3Fts5PoslistReaderNext(pIter);

  205223.   return pIter->bEof;

  205224. }

  205225. 

  205226. /*

  205227. ** Append position iPos to the position list being accumulated in buffer

  205228. ** pBuf, which must be already be large enough to hold the new data.

  205229. ** The previous position written to this list is *piPrev. *piPrev is set

  205230. ** to iPos before returning.

  205231. */

  205232. static void sqlite3Fts5PoslistSafeAppend(

  205233.   Fts5Buffer *pBuf, 

  205234.   i64 *piPrev, 

  205235.   i64 iPos

  205236. ){

  205237.   static const i64 colmask = ((i64)(0x7FFFFFFF)) << 32;

  205238.   if( (iPos & colmask) != (*piPrev & colmask) ){

  205239.     pBuf->p[pBuf->n++] = 1;

  205240.     pBuf->n += sqlite3Fts5PutVarint(&pBuf->p[pBuf->n], (iPos>>32));

  205241.     *piPrev = (iPos & colmask);

  205242.   }

  205243.   pBuf->n += sqlite3Fts5PutVarint(&pBuf->p[pBuf->n], (iPos-*piPrev)+2);

  205244.   *piPrev = iPos;

  205245. }

  205246. 

  205247. static int sqlite3Fts5PoslistWriterAppend(

  205248.   Fts5Buffer *pBuf, 

  205249.   Fts5PoslistWriter *pWriter,

  205250.   i64 iPos

  205251. ){

  205252.   int rc = 0;   /* Initialized only to suppress erroneous warning from Clang */

  205253.   if( fts5BufferGrow(&rc, pBuf, 5+5+5) ) return rc;

  205254.   sqlite3Fts5PoslistSafeAppend(pBuf, &pWriter->iPrev, iPos);

  205255.   return SQLITE_OK;

  205256. }

  205257. 

  205258. static void *sqlite3Fts5MallocZero(int *pRc, sqlite3_int64 nByte){

  205259.   void *pRet = 0;

  205260.   if( *pRc==SQLITE_OK ){

  205261.     pRet = sqlite3_malloc64(nByte);

  205262.     if( pRet==0 ){

  205263.       if( nByte>0 ) *pRc = SQLITE_NOMEM;

  205264.     }else{

  205265.       memset(pRet, 0, (size_t)nByte);

  205266.     }

  205267.   }

  205268.   return pRet;

  205269. }

  205270. 

  205271. /*

  205272. ** Return a nul-terminated copy of the string indicated by pIn. If nIn

  205273. ** is non-negative, then it is the length of the string in bytes. Otherwise,

  205274. ** the length of the string is determined using strlen().

  205275. **

  205276. ** It is the responsibility of the caller to eventually free the returned

  205277. ** buffer using sqlite3_free(). If an OOM error occurs, NULL is returned. 

  205278. */

  205279. static char *sqlite3Fts5Strndup(int *pRc, const char *pIn, int nIn){

  205280.   char *zRet = 0;

  205281.   if( *pRc==SQLITE_OK ){

  205282.     if( nIn<0 ){

  205283.       nIn = (int)strlen(pIn);

  205284.     }

  205285.     zRet = (char*)sqlite3_malloc(nIn+1);

  205286.     if( zRet ){

  205287.       memcpy(zRet, pIn, nIn);

  205288.       zRet[nIn] = '\0';

  205289.     }else{

  205290.       *pRc = SQLITE_NOMEM;

  205291.     }

  205292.   }

  205293.   return zRet;

  205294. }

  205295. 

  205296. 

  205297. /*

  205298. ** Return true if character 't' may be part of an FTS5 bareword, or false

  205299. ** otherwise. Characters that may be part of barewords:

  205300. **

  205301. **   * All non-ASCII characters,

  205302. **   * The 52 upper and lower case ASCII characters, and

  205303. **   * The 10 integer ASCII characters.

  205304. **   * The underscore character "_" (0x5F).

  205305. **   * The unicode "subsitute" character (0x1A).

  205306. */

  205307. static int sqlite3Fts5IsBareword(char t){

  205308.   u8 aBareword[128] = {

  205309.     0, 0, 0, 0, 0, 0, 0, 0,    0, 0, 0, 0, 0, 0, 0, 0,   /* 0x00 .. 0x0F */

  205310.     0, 0, 0, 0, 0, 0, 0, 0,    0, 0, 1, 0, 0, 0, 0, 0,   /* 0x10 .. 0x1F */

  205311.     0, 0, 0, 0, 0, 0, 0, 0,    0, 0, 0, 0, 0, 0, 0, 0,   /* 0x20 .. 0x2F */

  205312.     1, 1, 1, 1, 1, 1, 1, 1,    1, 1, 0, 0, 0, 0, 0, 0,   /* 0x30 .. 0x3F */

  205313.     0, 1, 1, 1, 1, 1, 1, 1,    1, 1, 1, 1, 1, 1, 1, 1,   /* 0x40 .. 0x4F */

  205314.     1, 1, 1, 1, 1, 1, 1, 1,    1, 1, 1, 0, 0, 0, 0, 1,   /* 0x50 .. 0x5F */

  205315.     0, 1, 1, 1, 1, 1, 1, 1,    1, 1, 1, 1, 1, 1, 1, 1,   /* 0x60 .. 0x6F */

  205316.     1, 1, 1, 1, 1, 1, 1, 1,    1, 1, 1, 0, 0, 0, 0, 0    /* 0x70 .. 0x7F */

  205317.   };

  205318. 

  205319.   return (t & 0x80) || aBareword[(int)t];

  205320. }

  205321. 

  205322. 

  205323. /*************************************************************************

  205324. */

  205325. typedef struct Fts5TermsetEntry Fts5TermsetEntry;

  205326. struct Fts5TermsetEntry {

  205327.   char *pTerm;

  205328.   int nTerm;

  205329.   int iIdx;                       /* Index (main or aPrefix[] entry) */

  205330.   Fts5TermsetEntry *pNext;

  205331. };

  205332. 

  205333. struct Fts5Termset {

  205334.   Fts5TermsetEntry *apHash[512];

  205335. };

  205336. 

  205337. static int sqlite3Fts5TermsetNew(Fts5Termset **pp){

  205338.   int rc = SQLITE_OK;

  205339.   *pp = sqlite3Fts5MallocZero(&rc, sizeof(Fts5Termset));

  205340.   return rc;

  205341. }

  205342. 

  205343. static int sqlite3Fts5TermsetAdd(

  205344.   Fts5Termset *p, 

  205345.   int iIdx,

  205346.   const char *pTerm, int nTerm, 

  205347.   int *pbPresent

  205348. ){

  205349.   int rc = SQLITE_OK;

  205350.   *pbPresent = 0;

  205351.   if( p ){

  205352.     int i;

  205353.     u32 hash = 13;

  205354.     Fts5TermsetEntry *pEntry;

  205355. 

  205356.     /* Calculate a hash value for this term. This is the same hash checksum

  205357.     ** used by the fts5_hash.c module. This is not important for correct

  205358.     ** operation of the module, but is necessary to ensure that some tests

  205359.     ** designed to produce hash table collisions really do work.  */

  205360.     for(i=nTerm-1; i>=0; i--){

  205361.       hash = (hash << 3) ^ hash ^ pTerm[i];

  205362.     }

  205363.     hash = (hash << 3) ^ hash ^ iIdx;

  205364.     hash = hash % ArraySize(p->apHash);

  205365. 

  205366.     for(pEntry=p->apHash[hash]; pEntry; pEntry=pEntry->pNext){

  205367.       if( pEntry->iIdx==iIdx 

  205368.           && pEntry->nTerm==nTerm 

  205369.           && memcmp(pEntry->pTerm, pTerm, nTerm)==0 

  205370.       ){

  205371.         *pbPresent = 1;

  205372.         break;

  205373.       }

  205374.     }

  205375. 

  205376.     if( pEntry==0 ){

  205377.       pEntry = sqlite3Fts5MallocZero(&rc, sizeof(Fts5TermsetEntry) + nTerm);

  205378.       if( pEntry ){

  205379.         pEntry->pTerm = (char*)&pEntry[1];

  205380.         pEntry->nTerm = nTerm;

  205381.         pEntry->iIdx = iIdx;

  205382.         memcpy(pEntry->pTerm, pTerm, nTerm);

  205383.         pEntry->pNext = p->apHash[hash];

  205384.         p->apHash[hash] = pEntry;

  205385.       }

  205386.     }

  205387.   }

  205388. 

  205389.   return rc;

  205390. }

  205391. 

  205392. static void sqlite3Fts5TermsetFree(Fts5Termset *p){

  205393.   if( p ){

  205394.     u32 i;

  205395.     for(i=0; i<ArraySize(p->apHash); i++){

  205396.       Fts5TermsetEntry *pEntry = p->apHash[i];

  205397.       while( pEntry ){

  205398.         Fts5TermsetEntry *pDel = pEntry;

  205399.         pEntry = pEntry->pNext;

  205400.         sqlite3_free(pDel);

  205401.       }

  205402.     }

  205403.     sqlite3_free(p);

  205404.   }

  205405. }

  205406. 

  205407. /*

  205408. ** 2014 Jun 09

  205409. **

  205410. ** The author disclaims copyright to this source code.  In place of

  205411. ** a legal notice, here is a blessing:

  205412. **

  205413. **    May you do good and not evil.

  205414. **    May you find forgiveness for yourself and forgive others.

  205415. **    May you share freely, never taking more than you give.

  205416. **

  205417. ******************************************************************************

  205418. **

  205419. ** This is an SQLite module implementing full-text search.

  205420. */

  205421. 

  205422. 

  205423. /* #include "fts5Int.h" */

  205424. 

  205425. #define FTS5_DEFAULT_PAGE_SIZE   4050

  205426. #define FTS5_DEFAULT_AUTOMERGE      4

  205427. #define FTS5_DEFAULT_USERMERGE      4

  205428. #define FTS5_DEFAULT_CRISISMERGE   16

  205429. #define FTS5_DEFAULT_HASHSIZE    (1024*1024)

  205430. 

  205431. /* Maximum allowed page size */

  205432. #define FTS5_MAX_PAGE_SIZE (128*1024)

  205433. 

  205434. static int fts5_iswhitespace(char x){

  205435.   return (x==' ');

  205436. }

  205437. 

  205438. static int fts5_isopenquote(char x){

  205439.   return (x=='"' || x=='\'' || x=='[' || x=='`');

  205440. }

  205441. 

  205442. /*

  205443. ** Argument pIn points to a character that is part of a nul-terminated 

  205444. ** string. Return a pointer to the first character following *pIn in 

  205445. ** the string that is not a white-space character.

  205446. */

  205447. static const char *fts5ConfigSkipWhitespace(const char *pIn){

  205448.   const char *p = pIn;

  205449.   if( p ){

  205450.     while( fts5_iswhitespace(*p) ){ p++; }

  205451.   }

  205452.   return p;

  205453. }

  205454. 

  205455. /*

  205456. ** Argument pIn points to a character that is part of a nul-terminated 

  205457. ** string. Return a pointer to the first character following *pIn in 

  205458. ** the string that is not a "bareword" character.

  205459. */

  205460. static const char *fts5ConfigSkipBareword(const char *pIn){

  205461.   const char *p = pIn;

  205462.   while ( sqlite3Fts5IsBareword(*p) ) p++;

  205463.   if( p==pIn ) p = 0;

  205464.   return p;

  205465. }

  205466. 

  205467. static int fts5_isdigit(char a){

  205468.   return (a>='0' && a<='9');

  205469. }

  205470. 

  205471. 

  205472. 

  205473. static const char *fts5ConfigSkipLiteral(const char *pIn){

  205474.   const char *p = pIn;

  205475.   switch( *p ){

  205476.     case 'n': case 'N':

  205477.       if( sqlite3_strnicmp("null", p, 4)==0 ){

  205478.         p = &p[4];

  205479.       }else{

  205480.         p = 0;

  205481.       }

  205482.       break;

  205483. 

  205484.     case 'x': case 'X':

  205485.       p++;

  205486.       if( *p=='\'' ){

  205487.         p++;

  205488.         while( (*p>='a' && *p<='f') 

  205489.             || (*p>='A' && *p<='F') 

  205490.             || (*p>='0' && *p<='9') 

  205491.             ){

  205492.           p++;

  205493.         }

  205494.         if( *p=='\'' && 0==((p-pIn)%2) ){

  205495.           p++;

  205496.         }else{

  205497.           p = 0;

  205498.         }

  205499.       }else{

  205500.         p = 0;

  205501.       }

  205502.       break;

  205503. 

  205504.     case '\'':

  205505.       p++;

  205506.       while( p ){

  205507.         if( *p=='\'' ){

  205508.           p++;

  205509.           if( *p!='\'' ) break;

  205510.         }

  205511.         p++;

  205512.         if( *p==0 ) p = 0;

  205513.       }

  205514.       break;

  205515. 

  205516.     default:

  205517.       /* maybe a number */

  205518.       if( *p=='+' || *p=='-' ) p++;

  205519.       while( fts5_isdigit(*p) ) p++;

  205520. 

  205521.       /* At this point, if the literal was an integer, the parse is 

  205522.       ** finished. Or, if it is a floating point value, it may continue

  205523.       ** with either a decimal point or an 'E' character. */

  205524.       if( *p=='.' && fts5_isdigit(p[1]) ){

  205525.         p += 2;

  205526.         while( fts5_isdigit(*p) ) p++;

  205527.       }

  205528.       if( p==pIn ) p = 0;

  205529. 

  205530.       break;

  205531.   }

  205532. 

  205533.   return p;

  205534. }

  205535. 

  205536. /*

  205537. ** The first character of the string pointed to by argument z is guaranteed

  205538. ** to be an open-quote character (see function fts5_isopenquote()).

  205539. **

  205540. ** This function searches for the corresponding close-quote character within

  205541. ** the string and, if found, dequotes the string in place and adds a new

  205542. ** nul-terminator byte.

  205543. **

  205544. ** If the close-quote is found, the value returned is the byte offset of

  205545. ** the character immediately following it. Or, if the close-quote is not 

  205546. ** found, -1 is returned. If -1 is returned, the buffer is left in an 

  205547. ** undefined state.

  205548. */

  205549. static int fts5Dequote(char *z){

  205550.   char q;

  205551.   int iIn = 1;

  205552.   int iOut = 0;

  205553.   q = z[0];

  205554. 

  205555.   /* Set stack variable q to the close-quote character */

  205556.   assert( q=='[' || q=='\'' || q=='"' || q=='`' );

  205557.   if( q=='[' ) q = ']';  

  205558. 

  205559.   while( ALWAYS(z[iIn]) ){

  205560.     if( z[iIn]==q ){

  205561.       if( z[iIn+1]!=q ){

  205562.         /* Character iIn was the close quote. */

  205563.         iIn++;

  205564.         break;

  205565.       }else{

  205566.         /* Character iIn and iIn+1 form an escaped quote character. Skip

  205567.         ** the input cursor past both and copy a single quote character 

  205568.         ** to the output buffer. */

  205569.         iIn += 2;

  205570.         z[iOut++] = q;

  205571.       }

  205572.     }else{

  205573.       z[iOut++] = z[iIn++];

  205574.     }

  205575.   }

  205576. 

  205577.   z[iOut] = '\0';

  205578.   return iIn;

  205579. }

  205580. 

  205581. /*

  205582. ** Convert an SQL-style quoted string into a normal string by removing

  205583. ** the quote characters.  The conversion is done in-place.  If the

  205584. ** input does not begin with a quote character, then this routine

  205585. ** is a no-op.

  205586. **

  205587. ** Examples:

  205588. **

  205589. **     "abc"   becomes   abc

  205590. **     'xyz'   becomes   xyz

  205591. **     [pqr]   becomes   pqr

  205592. **     `mno`   becomes   mno

  205593. */

  205594. static void sqlite3Fts5Dequote(char *z){

  205595.   char quote;                     /* Quote character (if any ) */

  205596. 

  205597.   assert( 0==fts5_iswhitespace(z[0]) );

  205598.   quote = z[0];

  205599.   if( quote=='[' || quote=='\'' || quote=='"' || quote=='`' ){

  205600.     fts5Dequote(z);

  205601.   }

  205602. }

  205603. 

  205604. 

  205605. struct Fts5Enum {

  205606.   const char *zName;

  205607.   int eVal;

  205608. };

  205609. typedef struct Fts5Enum Fts5Enum;

  205610. 

  205611. static int fts5ConfigSetEnum(

  205612.   const Fts5Enum *aEnum, 

  205613.   const char *zEnum, 

  205614.   int *peVal

  205615. ){

  205616.   int nEnum = (int)strlen(zEnum);

  205617.   int i;

  205618.   int iVal = -1;

  205619. 

  205620.   for(i=0; aEnum[i].zName; i++){

  205621.     if( sqlite3_strnicmp(aEnum[i].zName, zEnum, nEnum)==0 ){

  205622.       if( iVal>=0 ) return SQLITE_ERROR;

  205623.       iVal = aEnum[i].eVal;

  205624.     }

  205625.   }

  205626. 

  205627.   *peVal = iVal;

  205628.   return iVal<0 ? SQLITE_ERROR : SQLITE_OK;

  205629. }

  205630. 

  205631. /*

  205632. ** Parse a "special" CREATE VIRTUAL TABLE directive and update

  205633. ** configuration object pConfig as appropriate.

  205634. **

  205635. ** If successful, object pConfig is updated and SQLITE_OK returned. If

  205636. ** an error occurs, an SQLite error code is returned and an error message

  205637. ** may be left in *pzErr. It is the responsibility of the caller to

  205638. ** eventually free any such error message using sqlite3_free().

  205639. */

  205640. static int fts5ConfigParseSpecial(

  205641.   Fts5Global *pGlobal,

  205642.   Fts5Config *pConfig,            /* Configuration object to update */

  205643.   const char *zCmd,               /* Special command to parse */

  205644.   const char *zArg,               /* Argument to parse */

  205645.   char **pzErr                    /* OUT: Error message */

  205646. ){

  205647.   int rc = SQLITE_OK;

  205648.   int nCmd = (int)strlen(zCmd);

  205649.   if( sqlite3_strnicmp("prefix", zCmd, nCmd)==0 ){

  205650.     const int nByte = sizeof(int) * FTS5_MAX_PREFIX_INDEXES;

  205651.     const char *p;

  205652.     int bFirst = 1;

  205653.     if( pConfig->aPrefix==0 ){

  205654.       pConfig->aPrefix = sqlite3Fts5MallocZero(&rc, nByte);

  205655.       if( rc ) return rc;

  205656.     }

  205657. 

  205658.     p = zArg;

  205659.     while( 1 ){

  205660.       int nPre = 0;

  205661. 

  205662.       while( p[0]==' ' ) p++;

  205663.       if( bFirst==0 && p[0]==',' ){

  205664.         p++;

  205665.         while( p[0]==' ' ) p++;

  205666.       }else if( p[0]=='\0' ){

  205667.         break;

  205668.       }

  205669.       if( p[0]<'0' || p[0]>'9' ){

  205670.         *pzErr = sqlite3_mprintf("malformed prefix=... directive");

  205671.         rc = SQLITE_ERROR;

  205672.         break;

  205673.       }

  205674. 

  205675.       if( pConfig->nPrefix==FTS5_MAX_PREFIX_INDEXES ){

  205676.         *pzErr = sqlite3_mprintf(

  205677.             "too many prefix indexes (max %d)", FTS5_MAX_PREFIX_INDEXES

  205678.         );

  205679.         rc = SQLITE_ERROR;

  205680.         break;

  205681.       }

  205682. 

  205683.       while( p[0]>='0' && p[0]<='9' && nPre<1000 ){

  205684.         nPre = nPre*10 + (p[0] - '0');

  205685.         p++;

  205686.       }

  205687. 

  205688.       if( nPre<=0 || nPre>=1000 ){

  205689.         *pzErr = sqlite3_mprintf("prefix length out of range (max 999)");

  205690.         rc = SQLITE_ERROR;

  205691.         break;

  205692.       }

  205693. 

  205694.       pConfig->aPrefix[pConfig->nPrefix] = nPre;

  205695.       pConfig->nPrefix++;

  205696.       bFirst = 0;

  205697.     }

  205698.     assert( pConfig->nPrefix<=FTS5_MAX_PREFIX_INDEXES );

  205699.     return rc;

  205700.   }

  205701. 

  205702.   if( sqlite3_strnicmp("tokenize", zCmd, nCmd)==0 ){

  205703.     const char *p = (const char*)zArg;

  205704.     sqlite3_int64 nArg = strlen(zArg) + 1;

  205705.     char **azArg = sqlite3Fts5MallocZero(&rc, sizeof(char*) * nArg);

  205706.     char *pDel = sqlite3Fts5MallocZero(&rc, nArg * 2);

  205707.     char *pSpace = pDel;

  205708. 

  205709.     if( azArg && pSpace ){

  205710.       if( pConfig->pTok ){

  205711.         *pzErr = sqlite3_mprintf("multiple tokenize=... directives");

  205712.         rc = SQLITE_ERROR;

  205713.       }else{

  205714.         for(nArg=0; p && *p; nArg++){

  205715.           const char *p2 = fts5ConfigSkipWhitespace(p);

  205716.           if( *p2=='\'' ){

  205717.             p = fts5ConfigSkipLiteral(p2);

  205718.           }else{

  205719.             p = fts5ConfigSkipBareword(p2);

  205720.           }

  205721.           if( p ){

  205722.             memcpy(pSpace, p2, p-p2);

  205723.             azArg[nArg] = pSpace;

  205724.             sqlite3Fts5Dequote(pSpace);

  205725.             pSpace += (p - p2) + 1;

  205726.             p = fts5ConfigSkipWhitespace(p);

  205727.           }

  205728.         }

  205729.         if( p==0 ){

  205730.           *pzErr = sqlite3_mprintf("parse error in tokenize directive");

  205731.           rc = SQLITE_ERROR;

  205732.         }else{

  205733.           rc = sqlite3Fts5GetTokenizer(pGlobal, 

  205734.               (const char**)azArg, (int)nArg, &pConfig->pTok, &pConfig->pTokApi,

  205735.               pzErr

  205736.           );

  205737.         }

  205738.       }

  205739.     }

  205740. 

  205741.     sqlite3_free(azArg);

  205742.     sqlite3_free(pDel);

  205743.     return rc;

  205744.   }

  205745. 

  205746.   if( sqlite3_strnicmp("content", zCmd, nCmd)==0 ){

  205747.     if( pConfig->eContent!=FTS5_CONTENT_NORMAL ){

  205748.       *pzErr = sqlite3_mprintf("multiple content=... directives");

  205749.       rc = SQLITE_ERROR;

  205750.     }else{

  205751.       if( zArg[0] ){

  205752.         pConfig->eContent = FTS5_CONTENT_EXTERNAL;

  205753.         pConfig->zContent = sqlite3Fts5Mprintf(&rc, "%Q.%Q", pConfig->zDb,zArg);

  205754.       }else{

  205755.         pConfig->eContent = FTS5_CONTENT_NONE;

  205756.       }

  205757.     }

  205758.     return rc;

  205759.   }

  205760. 

  205761.   if( sqlite3_strnicmp("content_rowid", zCmd, nCmd)==0 ){

  205762.     if( pConfig->zContentRowid ){

  205763.       *pzErr = sqlite3_mprintf("multiple content_rowid=... directives");

  205764.       rc = SQLITE_ERROR;

  205765.     }else{

  205766.       pConfig->zContentRowid = sqlite3Fts5Strndup(&rc, zArg, -1);

  205767.     }

  205768.     return rc;

  205769.   }

  205770. 

  205771.   if( sqlite3_strnicmp("columnsize", zCmd, nCmd)==0 ){

  205772.     if( (zArg[0]!='0' && zArg[0]!='1') || zArg[1]!='\0' ){

  205773.       *pzErr = sqlite3_mprintf("malformed columnsize=... directive");

  205774.       rc = SQLITE_ERROR;

  205775.     }else{

  205776.       pConfig->bColumnsize = (zArg[0]=='1');

  205777.     }

  205778.     return rc;

  205779.   }

  205780. 

  205781.   if( sqlite3_strnicmp("detail", zCmd, nCmd)==0 ){

  205782.     const Fts5Enum aDetail[] = {

  205783.       { "none", FTS5_DETAIL_NONE },

  205784.       { "full", FTS5_DETAIL_FULL },

  205785.       { "columns", FTS5_DETAIL_COLUMNS },

  205786.       { 0, 0 }

  205787.     };

  205788. 

  205789.     if( (rc = fts5ConfigSetEnum(aDetail, zArg, &pConfig->eDetail)) ){

  205790.       *pzErr = sqlite3_mprintf("malformed detail=... directive");

  205791.     }

  205792.     return rc;

  205793.   }

  205794. 

  205795.   *pzErr = sqlite3_mprintf("unrecognized option: \"%.*s\"", nCmd, zCmd);

  205796.   return SQLITE_ERROR;

  205797. }

  205798. 

  205799. /*

  205800. ** Allocate an instance of the default tokenizer ("simple") at 

  205801. ** Fts5Config.pTokenizer. Return SQLITE_OK if successful, or an SQLite error

  205802. ** code if an error occurs.

  205803. */

  205804. static int fts5ConfigDefaultTokenizer(Fts5Global *pGlobal, Fts5Config *pConfig){

  205805.   assert( pConfig->pTok==0 && pConfig->pTokApi==0 );

  205806.   return sqlite3Fts5GetTokenizer(

  205807.       pGlobal, 0, 0, &pConfig->pTok, &pConfig->pTokApi, 0

  205808.   );

  205809. }

  205810. 

  205811. /*

  205812. ** Gobble up the first bareword or quoted word from the input buffer zIn.

  205813. ** Return a pointer to the character immediately following the last in

  205814. ** the gobbled word if successful, or a NULL pointer otherwise (failed

  205815. ** to find close-quote character).

  205816. **

  205817. ** Before returning, set pzOut to point to a new buffer containing a

  205818. ** nul-terminated, dequoted copy of the gobbled word. If the word was

  205819. ** quoted, *pbQuoted is also set to 1 before returning.

  205820. **

  205821. ** If *pRc is other than SQLITE_OK when this function is called, it is

  205822. ** a no-op (NULL is returned). Otherwise, if an OOM occurs within this

  205823. ** function, *pRc is set to SQLITE_NOMEM before returning. *pRc is *not*

  205824. ** set if a parse error (failed to find close quote) occurs.

  205825. */

  205826. static const char *fts5ConfigGobbleWord(

  205827.   int *pRc,                       /* IN/OUT: Error code */

  205828.   const char *zIn,                /* Buffer to gobble string/bareword from */

  205829.   char **pzOut,                   /* OUT: malloc'd buffer containing str/bw */

  205830.   int *pbQuoted                   /* OUT: Set to true if dequoting required */

  205831. ){

  205832.   const char *zRet = 0;

  205833. 

  205834.   sqlite3_int64 nIn = strlen(zIn);

  205835.   char *zOut = sqlite3_malloc64(nIn+1);

  205836. 

  205837.   assert( *pRc==SQLITE_OK );

  205838.   *pbQuoted = 0;

  205839.   *pzOut = 0;

  205840. 

  205841.   if( zOut==0 ){

  205842.     *pRc = SQLITE_NOMEM;

  205843.   }else{

  205844.     memcpy(zOut, zIn, (size_t)(nIn+1));

  205845.     if( fts5_isopenquote(zOut[0]) ){

  205846.       int ii = fts5Dequote(zOut);

  205847.       zRet = &zIn[ii];

  205848.       *pbQuoted = 1;

  205849.     }else{

  205850.       zRet = fts5ConfigSkipBareword(zIn);

  205851.       if( zRet ){

  205852.         zOut[zRet-zIn] = '\0';

  205853.       }

  205854.     }

  205855.   }

  205856. 

  205857.   if( zRet==0 ){

  205858.     sqlite3_free(zOut);

  205859.   }else{

  205860.     *pzOut = zOut;

  205861.   }

  205862. 

  205863.   return zRet;

  205864. }

  205865. 

  205866. static int fts5ConfigParseColumn(

  205867.   Fts5Config *p, 

  205868.   char *zCol, 

  205869.   char *zArg, 

  205870.   char **pzErr

  205871. ){

  205872.   int rc = SQLITE_OK;

  205873.   if( 0==sqlite3_stricmp(zCol, FTS5_RANK_NAME) 

  205874.    || 0==sqlite3_stricmp(zCol, FTS5_ROWID_NAME) 

  205875.   ){

  205876.     *pzErr = sqlite3_mprintf("reserved fts5 column name: %s", zCol);

  205877.     rc = SQLITE_ERROR;

  205878.   }else if( zArg ){

  205879.     if( 0==sqlite3_stricmp(zArg, "unindexed") ){

  205880.       p->abUnindexed[p->nCol] = 1;

  205881.     }else{

  205882.       *pzErr = sqlite3_mprintf("unrecognized column option: %s", zArg);

  205883.       rc = SQLITE_ERROR;

  205884.     }

  205885.   }

  205886. 

  205887.   p->azCol[p->nCol++] = zCol;

  205888.   return rc;

  205889. }

  205890. 

  205891. /*

  205892. ** Populate the Fts5Config.zContentExprlist string.

  205893. */

  205894. static int fts5ConfigMakeExprlist(Fts5Config *p){

  205895.   int i;

  205896.   int rc = SQLITE_OK;

  205897.   Fts5Buffer buf = {0, 0, 0};

  205898. 

  205899.   sqlite3Fts5BufferAppendPrintf(&rc, &buf, "T.%Q", p->zContentRowid);

  205900.   if( p->eContent!=FTS5_CONTENT_NONE ){

  205901.     for(i=0; i<p->nCol; i++){

  205902.       if( p->eContent==FTS5_CONTENT_EXTERNAL ){

  205903.         sqlite3Fts5BufferAppendPrintf(&rc, &buf, ", T.%Q", p->azCol[i]);

  205904.       }else{

  205905.         sqlite3Fts5BufferAppendPrintf(&rc, &buf, ", T.c%d", i);

  205906.       }

  205907.     }

  205908.   }

  205909. 

  205910.   assert( p->zContentExprlist==0 );

  205911.   p->zContentExprlist = (char*)buf.p;

  205912.   return rc;

  205913. }

  205914. 

  205915. /*

  205916. ** Arguments nArg/azArg contain the string arguments passed to the xCreate

  205917. ** or xConnect method of the virtual table. This function attempts to 

  205918. ** allocate an instance of Fts5Config containing the results of parsing

  205919. ** those arguments.

  205920. **

  205921. ** If successful, SQLITE_OK is returned and *ppOut is set to point to the

  205922. ** new Fts5Config object. If an error occurs, an SQLite error code is 

  205923. ** returned, *ppOut is set to NULL and an error message may be left in

  205924. ** *pzErr. It is the responsibility of the caller to eventually free any 

  205925. ** such error message using sqlite3_free().

  205926. */

  205927. static int sqlite3Fts5ConfigParse(

  205928.   Fts5Global *pGlobal,

  205929.   sqlite3 *db,

  205930.   int nArg,                       /* Number of arguments */

  205931.   const char **azArg,             /* Array of nArg CREATE VIRTUAL TABLE args */

  205932.   Fts5Config **ppOut,             /* OUT: Results of parse */

  205933.   char **pzErr                    /* OUT: Error message */

  205934. ){

  205935.   int rc = SQLITE_OK;             /* Return code */

  205936.   Fts5Config *pRet;               /* New object to return */

  205937.   int i;

  205938.   sqlite3_int64 nByte;

  205939. 

  205940.   *ppOut = pRet = (Fts5Config*)sqlite3_malloc(sizeof(Fts5Config));

  205941.   if( pRet==0 ) return SQLITE_NOMEM;

  205942.   memset(pRet, 0, sizeof(Fts5Config));

  205943.   pRet->db = db;

  205944.   pRet->iCookie = -1;

  205945. 

  205946.   nByte = nArg * (sizeof(char*) + sizeof(u8));

  205947.   pRet->azCol = (char**)sqlite3Fts5MallocZero(&rc, nByte);

  205948.   pRet->abUnindexed = (u8*)&pRet->azCol[nArg];

  205949.   pRet->zDb = sqlite3Fts5Strndup(&rc, azArg[1], -1);

  205950.   pRet->zName = sqlite3Fts5Strndup(&rc, azArg[2], -1);

  205951.   pRet->bColumnsize = 1;

  205952.   pRet->eDetail = FTS5_DETAIL_FULL;

  205953. #ifdef SQLITE_DEBUG

  205954.   pRet->bPrefixIndex = 1;

  205955. #endif

  205956.   if( rc==SQLITE_OK && sqlite3_stricmp(pRet->zName, FTS5_RANK_NAME)==0 ){

  205957.     *pzErr = sqlite3_mprintf("reserved fts5 table name: %s", pRet->zName);

  205958.     rc = SQLITE_ERROR;

  205959.   }

  205960. 

  205961.   for(i=3; rc==SQLITE_OK && i<nArg; i++){

  205962.     const char *zOrig = azArg[i];

  205963.     const char *z;

  205964.     char *zOne = 0;

  205965.     char *zTwo = 0;

  205966.     int bOption = 0;

  205967.     int bMustBeCol = 0;

  205968. 

  205969.     z = fts5ConfigGobbleWord(&rc, zOrig, &zOne, &bMustBeCol);

  205970.     z = fts5ConfigSkipWhitespace(z);

  205971.     if( z && *z=='=' ){

  205972.       bOption = 1;

  205973.       z++;

  205974.       if( bMustBeCol ) z = 0;

  205975.     }

  205976.     z = fts5ConfigSkipWhitespace(z);

  205977.     if( z && z[0] ){

  205978.       int bDummy;

  205979.       z = fts5ConfigGobbleWord(&rc, z, &zTwo, &bDummy);

  205980.       if( z && z[0] ) z = 0;

  205981.     }

  205982. 

  205983.     if( rc==SQLITE_OK ){

  205984.       if( z==0 ){

  205985.         *pzErr = sqlite3_mprintf("parse error in \"%s\"", zOrig);

  205986.         rc = SQLITE_ERROR;

  205987.       }else{

  205988.         if( bOption ){

  205989.           rc = fts5ConfigParseSpecial(pGlobal, pRet, zOne, zTwo?zTwo:"", pzErr);

  205990.         }else{

  205991.           rc = fts5ConfigParseColumn(pRet, zOne, zTwo, pzErr);

  205992.           zOne = 0;

  205993.         }

  205994.       }

  205995.     }

  205996. 

  205997.     sqlite3_free(zOne);

  205998.     sqlite3_free(zTwo);

  205999.   }

  206000. 

  206001.   /* If a tokenizer= option was successfully parsed, the tokenizer has

  206002.   ** already been allocated. Otherwise, allocate an instance of the default

  206003.   ** tokenizer (unicode61) now.  */

  206004.   if( rc==SQLITE_OK && pRet->pTok==0 ){

  206005.     rc = fts5ConfigDefaultTokenizer(pGlobal, pRet);

  206006.   }

  206007. 

  206008.   /* If no zContent option was specified, fill in the default values. */

  206009.   if( rc==SQLITE_OK && pRet->zContent==0 ){

  206010.     const char *zTail = 0;

  206011.     assert( pRet->eContent==FTS5_CONTENT_NORMAL 

  206012.          || pRet->eContent==FTS5_CONTENT_NONE 

  206013.     );

  206014.     if( pRet->eContent==FTS5_CONTENT_NORMAL ){

  206015.       zTail = "content";

  206016.     }else if( pRet->bColumnsize ){

  206017.       zTail = "docsize";

  206018.     }

  206019. 

  206020.     if( zTail ){

  206021.       pRet->zContent = sqlite3Fts5Mprintf(

  206022.           &rc, "%Q.'%q_%s'", pRet->zDb, pRet->zName, zTail

  206023.       );

  206024.     }

  206025.   }

  206026. 

  206027.   if( rc==SQLITE_OK && pRet->zContentRowid==0 ){

  206028.     pRet->zContentRowid = sqlite3Fts5Strndup(&rc, "rowid", -1);

  206029.   }

  206030. 

  206031.   /* Formulate the zContentExprlist text */

  206032.   if( rc==SQLITE_OK ){

  206033.     rc = fts5ConfigMakeExprlist(pRet);

  206034.   }

  206035. 

  206036.   if( rc!=SQLITE_OK ){

  206037.     sqlite3Fts5ConfigFree(pRet);

  206038.     *ppOut = 0;

  206039.   }

  206040.   return rc;

  206041. }

  206042. 

  206043. /*

  206044. ** Free the configuration object passed as the only argument.

  206045. */

  206046. static void sqlite3Fts5ConfigFree(Fts5Config *pConfig){

  206047.   if( pConfig ){

  206048.     int i;

  206049.     if( pConfig->pTok ){

  206050.       pConfig->pTokApi->xDelete(pConfig->pTok);

  206051.     }

  206052.     sqlite3_free(pConfig->zDb);

  206053.     sqlite3_free(pConfig->zName);

  206054.     for(i=0; i<pConfig->nCol; i++){

  206055.       sqlite3_free(pConfig->azCol[i]);

  206056.     }

  206057.     sqlite3_free(pConfig->azCol);

  206058.     sqlite3_free(pConfig->aPrefix);

  206059.     sqlite3_free(pConfig->zRank);

  206060.     sqlite3_free(pConfig->zRankArgs);

  206061.     sqlite3_free(pConfig->zContent);

  206062.     sqlite3_free(pConfig->zContentRowid);

  206063.     sqlite3_free(pConfig->zContentExprlist);

  206064.     sqlite3_free(pConfig);

  206065.   }

  206066. }

  206067. 

  206068. /*

  206069. ** Call sqlite3_declare_vtab() based on the contents of the configuration

  206070. ** object passed as the only argument. Return SQLITE_OK if successful, or

  206071. ** an SQLite error code if an error occurs.

  206072. */

  206073. static int sqlite3Fts5ConfigDeclareVtab(Fts5Config *pConfig){

  206074.   int i;

  206075.   int rc = SQLITE_OK;

  206076.   char *zSql;

  206077. 

  206078.   zSql = sqlite3Fts5Mprintf(&rc, "CREATE TABLE x(");

  206079.   for(i=0; zSql && i<pConfig->nCol; i++){

  206080.     const char *zSep = (i==0?"":", ");

  206081.     zSql = sqlite3Fts5Mprintf(&rc, "%z%s%Q", zSql, zSep, pConfig->azCol[i]);

  206082.   }

  206083.   zSql = sqlite3Fts5Mprintf(&rc, "%z, %Q HIDDEN, %s HIDDEN)", 

  206084.       zSql, pConfig->zName, FTS5_RANK_NAME

  206085.   );

  206086. 

  206087.   assert( zSql || rc==SQLITE_NOMEM );

  206088.   if( zSql ){

  206089.     rc = sqlite3_declare_vtab(pConfig->db, zSql);

  206090.     sqlite3_free(zSql);

  206091.   }

  206092.   

  206093.   return rc;

  206094. }

  206095. 

  206096. /*

  206097. ** Tokenize the text passed via the second and third arguments.

  206098. **

  206099. ** The callback is invoked once for each token in the input text. The

  206100. ** arguments passed to it are, in order:

  206101. **

  206102. **     void *pCtx          // Copy of 4th argument to sqlite3Fts5Tokenize()

  206103. **     const char *pToken  // Pointer to buffer containing token

  206104. **     int nToken          // Size of token in bytes

  206105. **     int iStart          // Byte offset of start of token within input text

  206106. **     int iEnd            // Byte offset of end of token within input text

  206107. **     int iPos            // Position of token in input (first token is 0)

  206108. **

  206109. ** If the callback returns a non-zero value the tokenization is abandoned

  206110. ** and no further callbacks are issued. 

  206111. **

  206112. ** This function returns SQLITE_OK if successful or an SQLite error code

  206113. ** if an error occurs. If the tokenization was abandoned early because

  206114. ** the callback returned SQLITE_DONE, this is not an error and this function

  206115. ** still returns SQLITE_OK. Or, if the tokenization was abandoned early

  206116. ** because the callback returned another non-zero value, it is assumed

  206117. ** to be an SQLite error code and returned to the caller.

  206118. */

  206119. static int sqlite3Fts5Tokenize(

  206120.   Fts5Config *pConfig,            /* FTS5 Configuration object */

  206121.   int flags,                      /* FTS5_TOKENIZE_* flags */

  206122.   const char *pText, int nText,   /* Text to tokenize */

  206123.   void *pCtx,                     /* Context passed to xToken() */

  206124.   int (*xToken)(void*, int, const char*, int, int, int)    /* Callback */

  206125. ){

  206126.   if( pText==0 ) return SQLITE_OK;

  206127.   return pConfig->pTokApi->xTokenize(

  206128.       pConfig->pTok, pCtx, flags, pText, nText, xToken

  206129.   );

  206130. }

  206131. 

  206132. /*

  206133. ** Argument pIn points to the first character in what is expected to be

  206134. ** a comma-separated list of SQL literals followed by a ')' character.

  206135. ** If it actually is this, return a pointer to the ')'. Otherwise, return

  206136. ** NULL to indicate a parse error.

  206137. */

  206138. static const char *fts5ConfigSkipArgs(const char *pIn){

  206139.   const char *p = pIn;

  206140.   

  206141.   while( 1 ){

  206142.     p = fts5ConfigSkipWhitespace(p);

  206143.     p = fts5ConfigSkipLiteral(p);

  206144.     p = fts5ConfigSkipWhitespace(p);

  206145.     if( p==0 || *p==')' ) break;

  206146.     if( *p!=',' ){

  206147.       p = 0;

  206148.       break;

  206149.     }

  206150.     p++;

  206151.   }

  206152. 

  206153.   return p;

  206154. }

  206155. 

  206156. /*

  206157. ** Parameter zIn contains a rank() function specification. The format of 

  206158. ** this is:

  206159. **

  206160. **   + Bareword (function name)

  206161. **   + Open parenthesis - "("

  206162. **   + Zero or more SQL literals in a comma separated list

  206163. **   + Close parenthesis - ")"

  206164. */

  206165. static int sqlite3Fts5ConfigParseRank(

  206166.   const char *zIn,                /* Input string */

  206167.   char **pzRank,                  /* OUT: Rank function name */

  206168.   char **pzRankArgs               /* OUT: Rank function arguments */

  206169. ){

  206170.   const char *p = zIn;

  206171.   const char *pRank;

  206172.   char *zRank = 0;

  206173.   char *zRankArgs = 0;

  206174.   int rc = SQLITE_OK;

  206175. 

  206176.   *pzRank = 0;

  206177.   *pzRankArgs = 0;

  206178. 

  206179.   if( p==0 ){

  206180.     rc = SQLITE_ERROR;

  206181.   }else{

  206182.     p = fts5ConfigSkipWhitespace(p);

  206183.     pRank = p;

  206184.     p = fts5ConfigSkipBareword(p);

  206185. 

  206186.     if( p ){

  206187.       zRank = sqlite3Fts5MallocZero(&rc, 1 + p - pRank);

  206188.       if( zRank ) memcpy(zRank, pRank, p-pRank);

  206189.     }else{

  206190.       rc = SQLITE_ERROR;

  206191.     }

  206192. 

  206193.     if( rc==SQLITE_OK ){

  206194.       p = fts5ConfigSkipWhitespace(p);

  206195.       if( *p!='(' ) rc = SQLITE_ERROR;

  206196.       p++;

  206197.     }

  206198.     if( rc==SQLITE_OK ){

  206199.       const char *pArgs; 

  206200.       p = fts5ConfigSkipWhitespace(p);

  206201.       pArgs = p;

  206202.       if( *p!=')' ){

  206203.         p = fts5ConfigSkipArgs(p);

  206204.         if( p==0 ){

  206205.           rc = SQLITE_ERROR;

  206206.         }else{

  206207.           zRankArgs = sqlite3Fts5MallocZero(&rc, 1 + p - pArgs);

  206208.           if( zRankArgs ) memcpy(zRankArgs, pArgs, p-pArgs);

  206209.         }

  206210.       }

  206211.     }

  206212.   }

  206213. 

  206214.   if( rc!=SQLITE_OK ){

  206215.     sqlite3_free(zRank);

  206216.     assert( zRankArgs==0 );

  206217.   }else{

  206218.     *pzRank = zRank;

  206219.     *pzRankArgs = zRankArgs;

  206220.   }

  206221.   return rc;

  206222. }

  206223. 

  206224. static int sqlite3Fts5ConfigSetValue(

  206225.   Fts5Config *pConfig, 

  206226.   const char *zKey, 

  206227.   sqlite3_value *pVal,

  206228.   int *pbBadkey

  206229. ){

  206230.   int rc = SQLITE_OK;

  206231. 

  206232.   if( 0==sqlite3_stricmp(zKey, "pgsz") ){

  206233.     int pgsz = 0;

  206234.     if( SQLITE_INTEGER==sqlite3_value_numeric_type(pVal) ){

  206235.       pgsz = sqlite3_value_int(pVal);

  206236.     }

  206237.     if( pgsz<=0 || pgsz>FTS5_MAX_PAGE_SIZE ){

  206238.       *pbBadkey = 1;

  206239.     }else{

  206240.       pConfig->pgsz = pgsz;

  206241.     }

  206242.   }

  206243. 

  206244.   else if( 0==sqlite3_stricmp(zKey, "hashsize") ){

  206245.     int nHashSize = -1;

  206246.     if( SQLITE_INTEGER==sqlite3_value_numeric_type(pVal) ){

  206247.       nHashSize = sqlite3_value_int(pVal);

  206248.     }

  206249.     if( nHashSize<=0 ){

  206250.       *pbBadkey = 1;

  206251.     }else{

  206252.       pConfig->nHashSize = nHashSize;

  206253.     }

  206254.   }

  206255. 

  206256.   else if( 0==sqlite3_stricmp(zKey, "automerge") ){

  206257.     int nAutomerge = -1;

  206258.     if( SQLITE_INTEGER==sqlite3_value_numeric_type(pVal) ){

  206259.       nAutomerge = sqlite3_value_int(pVal);

  206260.     }

  206261.     if( nAutomerge<0 || nAutomerge>64 ){

  206262.       *pbBadkey = 1;

  206263.     }else{

  206264.       if( nAutomerge==1 ) nAutomerge = FTS5_DEFAULT_AUTOMERGE;

  206265.       pConfig->nAutomerge = nAutomerge;

  206266.     }

  206267.   }

  206268. 

  206269.   else if( 0==sqlite3_stricmp(zKey, "usermerge") ){

  206270.     int nUsermerge = -1;

  206271.     if( SQLITE_INTEGER==sqlite3_value_numeric_type(pVal) ){

  206272.       nUsermerge = sqlite3_value_int(pVal);

  206273.     }

  206274.     if( nUsermerge<2 || nUsermerge>16 ){

  206275.       *pbBadkey = 1;

  206276.     }else{

  206277.       pConfig->nUsermerge = nUsermerge;

  206278.     }

  206279.   }

  206280. 

  206281.   else if( 0==sqlite3_stricmp(zKey, "crisismerge") ){

  206282.     int nCrisisMerge = -1;

  206283.     if( SQLITE_INTEGER==sqlite3_value_numeric_type(pVal) ){

  206284.       nCrisisMerge = sqlite3_value_int(pVal);

  206285.     }

  206286.     if( nCrisisMerge<0 ){

  206287.       *pbBadkey = 1;

  206288.     }else{

  206289.       if( nCrisisMerge<=1 ) nCrisisMerge = FTS5_DEFAULT_CRISISMERGE;

  206290.       pConfig->nCrisisMerge = nCrisisMerge;

  206291.     }

  206292.   }

  206293. 

  206294.   else if( 0==sqlite3_stricmp(zKey, "rank") ){

  206295.     const char *zIn = (const char*)sqlite3_value_text(pVal);

  206296.     char *zRank;

  206297.     char *zRankArgs;

  206298.     rc = sqlite3Fts5ConfigParseRank(zIn, &zRank, &zRankArgs);

  206299.     if( rc==SQLITE_OK ){

  206300.       sqlite3_free(pConfig->zRank);

  206301.       sqlite3_free(pConfig->zRankArgs);

  206302.       pConfig->zRank = zRank;

  206303.       pConfig->zRankArgs = zRankArgs;

  206304.     }else if( rc==SQLITE_ERROR ){

  206305.       rc = SQLITE_OK;

  206306.       *pbBadkey = 1;

  206307.     }

  206308.   }else{

  206309.     *pbBadkey = 1;

  206310.   }

  206311.   return rc;

  206312. }

  206313. 

  206314. /*

  206315. ** Load the contents of the %_config table into memory.

  206316. */

  206317. static int sqlite3Fts5ConfigLoad(Fts5Config *pConfig, int iCookie){

  206318.   const char *zSelect = "SELECT k, v FROM %Q.'%q_config'";

  206319.   char *zSql;

  206320.   sqlite3_stmt *p = 0;

  206321.   int rc = SQLITE_OK;

  206322.   int iVersion = 0;

  206323. 

  206324.   /* Set default values */

  206325.   pConfig->pgsz = FTS5_DEFAULT_PAGE_SIZE;

  206326.   pConfig->nAutomerge = FTS5_DEFAULT_AUTOMERGE;

  206327.   pConfig->nUsermerge = FTS5_DEFAULT_USERMERGE;

  206328.   pConfig->nCrisisMerge = FTS5_DEFAULT_CRISISMERGE;

  206329.   pConfig->nHashSize = FTS5_DEFAULT_HASHSIZE;

  206330. 

  206331.   zSql = sqlite3Fts5Mprintf(&rc, zSelect, pConfig->zDb, pConfig->zName);

  206332.   if( zSql ){

  206333.     rc = sqlite3_prepare_v2(pConfig->db, zSql, -1, &p, 0);

  206334.     sqlite3_free(zSql);

  206335.   }

  206336. 

  206337.   assert( rc==SQLITE_OK || p==0 );

  206338.   if( rc==SQLITE_OK ){

  206339.     while( SQLITE_ROW==sqlite3_step(p) ){

  206340.       const char *zK = (const char*)sqlite3_column_text(p, 0);

  206341.       sqlite3_value *pVal = sqlite3_column_value(p, 1);

  206342.       if( 0==sqlite3_stricmp(zK, "version") ){

  206343.         iVersion = sqlite3_value_int(pVal);

  206344.       }else{

  206345.         int bDummy = 0;

  206346.         sqlite3Fts5ConfigSetValue(pConfig, zK, pVal, &bDummy);

  206347.       }

  206348.     }

  206349.     rc = sqlite3_finalize(p);

  206350.   }

  206351.   

  206352.   if( rc==SQLITE_OK && iVersion!=FTS5_CURRENT_VERSION ){

  206353.     rc = SQLITE_ERROR;

  206354.     if( pConfig->pzErrmsg ){

  206355.       assert( 0==*pConfig->pzErrmsg );

  206356.       *pConfig->pzErrmsg = sqlite3_mprintf(

  206357.           "invalid fts5 file format (found %d, expected %d) - run 'rebuild'",

  206358.           iVersion, FTS5_CURRENT_VERSION

  206359.       );

  206360.     }

  206361.   }

  206362. 

  206363.   if( rc==SQLITE_OK ){

  206364.     pConfig->iCookie = iCookie;

  206365.   }

  206366.   return rc;

  206367. }

  206368. 

  206369. /*

  206370. ** 2014 May 31

  206371. **

  206372. ** The author disclaims copyright to this source code.  In place of

  206373. ** a legal notice, here is a blessing:

  206374. **

  206375. **    May you do good and not evil.

  206376. **    May you find forgiveness for yourself and forgive others.

  206377. **    May you share freely, never taking more than you give.

  206378. **

  206379. ******************************************************************************

  206380. **

  206381. */

  206382. 

  206383. 

  206384. 

  206385. /* #include "fts5Int.h" */

  206386. /* #include "fts5parse.h" */

  206387. 

  206388. /*

  206389. ** All token types in the generated fts5parse.h file are greater than 0.

  206390. */

  206391. #define FTS5_EOF 0

  206392. 

  206393. #define FTS5_LARGEST_INT64  (0xffffffff|(((i64)0x7fffffff)<<32))

  206394. 

  206395. typedef struct Fts5ExprTerm Fts5ExprTerm;

  206396. 

  206397. /*

  206398. ** Functions generated by lemon from fts5parse.y.

  206399. */

  206400. static void *sqlite3Fts5ParserAlloc(void *(*mallocProc)(u64));

  206401. static void sqlite3Fts5ParserFree(void*, void (*freeProc)(void*));

  206402. static void sqlite3Fts5Parser(void*, int, Fts5Token, Fts5Parse*);

  206403. #ifndef NDEBUG

  206404. /* #include <stdio.h> */

  206405. static void sqlite3Fts5ParserTrace(FILE*, char*);

  206406. #endif

  206407. static int sqlite3Fts5ParserFallback(int);

  206408. 

  206409. 

  206410. struct Fts5Expr {

  206411.   Fts5Index *pIndex;

  206412.   Fts5Config *pConfig;

  206413.   Fts5ExprNode *pRoot;

  206414.   int bDesc;                      /* Iterate in descending rowid order */

  206415.   int nPhrase;                    /* Number of phrases in expression */

  206416.   Fts5ExprPhrase **apExprPhrase;  /* Pointers to phrase objects */

  206417. };

  206418. 

  206419. /*

  206420. ** eType:

  206421. **   Expression node type. Always one of:

  206422. **

  206423. **       FTS5_AND                 (nChild, apChild valid)

  206424. **       FTS5_OR                  (nChild, apChild valid)

  206425. **       FTS5_NOT                 (nChild, apChild valid)

  206426. **       FTS5_STRING              (pNear valid)

  206427. **       FTS5_TERM                (pNear valid)

  206428. */

  206429. struct Fts5ExprNode {

  206430.   int eType;                      /* Node type */

  206431.   int bEof;                       /* True at EOF */

  206432.   int bNomatch;                   /* True if entry is not a match */

  206433. 

  206434.   /* Next method for this node. */

  206435.   int (*xNext)(Fts5Expr*, Fts5ExprNode*, int, i64);

  206436. 

  206437.   i64 iRowid;                     /* Current rowid */

  206438.   Fts5ExprNearset *pNear;         /* For FTS5_STRING - cluster of phrases */

  206439. 

  206440.   /* Child nodes. For a NOT node, this array always contains 2 entries. For 

  206441.   ** AND or OR nodes, it contains 2 or more entries.  */

  206442.   int nChild;                     /* Number of child nodes */

  206443.   Fts5ExprNode *apChild[1];       /* Array of child nodes */

  206444. };

  206445. 

  206446. #define Fts5NodeIsString(p) ((p)->eType==FTS5_TERM || (p)->eType==FTS5_STRING)

  206447. 

  206448. /*

  206449. ** Invoke the xNext method of an Fts5ExprNode object. This macro should be

  206450. ** used as if it has the same signature as the xNext() methods themselves.

  206451. */

  206452. #define fts5ExprNodeNext(a,b,c,d) (b)->xNext((a), (b), (c), (d))

  206453. 

  206454. /*

  206455. ** An instance of the following structure represents a single search term

  206456. ** or term prefix.

  206457. */

  206458. struct Fts5ExprTerm {

  206459.   u8 bPrefix;                     /* True for a prefix term */

  206460.   u8 bFirst;                      /* True if token must be first in column */

  206461.   char *zTerm;                    /* nul-terminated term */

  206462.   Fts5IndexIter *pIter;           /* Iterator for this term */

  206463.   Fts5ExprTerm *pSynonym;         /* Pointer to first in list of synonyms */

  206464. };

  206465. 

  206466. /*

  206467. ** A phrase. One or more terms that must appear in a contiguous sequence

  206468. ** within a document for it to match.

  206469. */

  206470. struct Fts5ExprPhrase {

  206471.   Fts5ExprNode *pNode;            /* FTS5_STRING node this phrase is part of */

  206472.   Fts5Buffer poslist;             /* Current position list */

  206473.   int nTerm;                      /* Number of entries in aTerm[] */

  206474.   Fts5ExprTerm aTerm[1];          /* Terms that make up this phrase */

  206475. };

  206476. 

  206477. /*

  206478. ** One or more phrases that must appear within a certain token distance of

  206479. ** each other within each matching document.

  206480. */

  206481. struct Fts5ExprNearset {

  206482.   int nNear;                      /* NEAR parameter */

  206483.   Fts5Colset *pColset;            /* Columns to search (NULL -> all columns) */

  206484.   int nPhrase;                    /* Number of entries in aPhrase[] array */

  206485.   Fts5ExprPhrase *apPhrase[1];    /* Array of phrase pointers */

  206486. };

  206487. 

  206488. 

  206489. /*

  206490. ** Parse context.

  206491. */

  206492. struct Fts5Parse {

  206493.   Fts5Config *pConfig;

  206494.   char *zErr;

  206495.   int rc;

  206496.   int nPhrase;                    /* Size of apPhrase array */

  206497.   Fts5ExprPhrase **apPhrase;      /* Array of all phrases */

  206498.   Fts5ExprNode *pExpr;            /* Result of a successful parse */

  206499. };

  206500. 

  206501. static void sqlite3Fts5ParseError(Fts5Parse *pParse, const char *zFmt, ...){

  206502.   va_list ap;

  206503.   va_start(ap, zFmt);

  206504.   if( pParse->rc==SQLITE_OK ){

  206505.     pParse->zErr = sqlite3_vmprintf(zFmt, ap);

  206506.     pParse->rc = SQLITE_ERROR;

  206507.   }

  206508.   va_end(ap);

  206509. }

  206510. 

  206511. static int fts5ExprIsspace(char t){

  206512.   return t==' ' || t=='\t' || t=='\n' || t=='\r';

  206513. }

  206514. 

  206515. /*

  206516. ** Read the first token from the nul-terminated string at *pz.

  206517. */

  206518. static int fts5ExprGetToken(

  206519.   Fts5Parse *pParse, 

  206520.   const char **pz,                /* IN/OUT: Pointer into buffer */

  206521.   Fts5Token *pToken

  206522. ){

  206523.   const char *z = *pz;

  206524.   int tok;

  206525. 

  206526.   /* Skip past any whitespace */

  206527.   while( fts5ExprIsspace(*z) ) z++;

  206528. 

  206529.   pToken->p = z;

  206530.   pToken->n = 1;

  206531.   switch( *z ){

  206532.     case '(':  tok = FTS5_LP;    break;

  206533.     case ')':  tok = FTS5_RP;    break;

  206534.     case '{':  tok = FTS5_LCP;   break;

  206535.     case '}':  tok = FTS5_RCP;   break;

  206536.     case ':':  tok = FTS5_COLON; break;

  206537.     case ',':  tok = FTS5_COMMA; break;

  206538.     case '+':  tok = FTS5_PLUS;  break;

  206539.     case '*':  tok = FTS5_STAR;  break;

  206540.     case '-':  tok = FTS5_MINUS; break;

  206541.     case '^':  tok = FTS5_CARET; break;

  206542.     case '\0': tok = FTS5_EOF;   break;

  206543. 

  206544.     case '"': {

  206545.       const char *z2;

  206546.       tok = FTS5_STRING;

  206547. 

  206548.       for(z2=&z[1]; 1; z2++){

  206549.         if( z2[0]=='"' ){

  206550.           z2++;

  206551.           if( z2[0]!='"' ) break;

  206552.         }

  206553.         if( z2[0]=='\0' ){

  206554.           sqlite3Fts5ParseError(pParse, "unterminated string");

  206555.           return FTS5_EOF;

  206556.         }

  206557.       }

  206558.       pToken->n = (z2 - z);

  206559.       break;

  206560.     }

  206561. 

  206562.     default: {

  206563.       const char *z2;

  206564.       if( sqlite3Fts5IsBareword(z[0])==0 ){

  206565.         sqlite3Fts5ParseError(pParse, "fts5: syntax error near \"%.1s\"", z);

  206566.         return FTS5_EOF;

  206567.       }

  206568.       tok = FTS5_STRING;

  206569.       for(z2=&z[1]; sqlite3Fts5IsBareword(*z2); z2++);

  206570.       pToken->n = (z2 - z);

  206571.       if( pToken->n==2 && memcmp(pToken->p, "OR", 2)==0 )  tok = FTS5_OR;

  206572.       if( pToken->n==3 && memcmp(pToken->p, "NOT", 3)==0 ) tok = FTS5_NOT;

  206573.       if( pToken->n==3 && memcmp(pToken->p, "AND", 3)==0 ) tok = FTS5_AND;

  206574.       break;

  206575.     }

  206576.   }

  206577. 

  206578.   *pz = &pToken->p[pToken->n];

  206579.   return tok;

  206580. }

  206581. 

  206582. static void *fts5ParseAlloc(u64 t){ return sqlite3_malloc64((sqlite3_int64)t);}

  206583. static void fts5ParseFree(void *p){ sqlite3_free(p); }

  206584. 

  206585. static int sqlite3Fts5ExprNew(

  206586.   Fts5Config *pConfig,            /* FTS5 Configuration */

  206587.   int iCol,

  206588.   const char *zExpr,              /* Expression text */

  206589.   Fts5Expr **ppNew, 

  206590.   char **pzErr

  206591. ){

  206592.   Fts5Parse sParse;

  206593.   Fts5Token token;

  206594.   const char *z = zExpr;

  206595.   int t;                          /* Next token type */

  206596.   void *pEngine;

  206597.   Fts5Expr *pNew;

  206598. 

  206599.   *ppNew = 0;

  206600.   *pzErr = 0;

  206601.   memset(&sParse, 0, sizeof(sParse));

  206602.   pEngine = sqlite3Fts5ParserAlloc(fts5ParseAlloc);

  206603.   if( pEngine==0 ){ return SQLITE_NOMEM; }

  206604.   sParse.pConfig = pConfig;

  206605. 

  206606.   do {

  206607.     t = fts5ExprGetToken(&sParse, &z, &token);

  206608.     sqlite3Fts5Parser(pEngine, t, token, &sParse);

  206609.   }while( sParse.rc==SQLITE_OK && t!=FTS5_EOF );

  206610.   sqlite3Fts5ParserFree(pEngine, fts5ParseFree);

  206611. 

  206612.   /* If the LHS of the MATCH expression was a user column, apply the

  206613.   ** implicit column-filter.  */

  206614.   if( iCol<pConfig->nCol && sParse.pExpr && sParse.rc==SQLITE_OK ){

  206615.     int n = sizeof(Fts5Colset);

  206616.     Fts5Colset *pColset = (Fts5Colset*)sqlite3Fts5MallocZero(&sParse.rc, n);

  206617.     if( pColset ){

  206618.       pColset->nCol = 1;

  206619.       pColset->aiCol[0] = iCol;

  206620.       sqlite3Fts5ParseSetColset(&sParse, sParse.pExpr, pColset);

  206621.     }

  206622.   }

  206623. 

  206624.   assert( sParse.rc!=SQLITE_OK || sParse.zErr==0 );

  206625.   if( sParse.rc==SQLITE_OK ){

  206626.     *ppNew = pNew = sqlite3_malloc(sizeof(Fts5Expr));

  206627.     if( pNew==0 ){

  206628.       sParse.rc = SQLITE_NOMEM;

  206629.       sqlite3Fts5ParseNodeFree(sParse.pExpr);

  206630.     }else{

  206631.       if( !sParse.pExpr ){

  206632.         const int nByte = sizeof(Fts5ExprNode);

  206633.         pNew->pRoot = (Fts5ExprNode*)sqlite3Fts5MallocZero(&sParse.rc, nByte);

  206634.         if( pNew->pRoot ){

  206635.           pNew->pRoot->bEof = 1;

  206636.         }

  206637.       }else{

  206638.         pNew->pRoot = sParse.pExpr;

  206639.       }

  206640.       pNew->pIndex = 0;

  206641.       pNew->pConfig = pConfig;

  206642.       pNew->apExprPhrase = sParse.apPhrase;

  206643.       pNew->nPhrase = sParse.nPhrase;

  206644.       sParse.apPhrase = 0;

  206645.     }

  206646.   }else{

  206647.     sqlite3Fts5ParseNodeFree(sParse.pExpr);

  206648.   }

  206649. 

  206650.   sqlite3_free(sParse.apPhrase);

  206651.   *pzErr = sParse.zErr;

  206652.   return sParse.rc;

  206653. }

  206654. 

  206655. /*

  206656. ** Free the expression node object passed as the only argument.

  206657. */

  206658. static void sqlite3Fts5ParseNodeFree(Fts5ExprNode *p){

  206659.   if( p ){

  206660.     int i;

  206661.     for(i=0; i<p->nChild; i++){

  206662.       sqlite3Fts5ParseNodeFree(p->apChild[i]);

  206663.     }

  206664.     sqlite3Fts5ParseNearsetFree(p->pNear);

  206665.     sqlite3_free(p);

  206666.   }

  206667. }

  206668. 

  206669. /*

  206670. ** Free the expression object passed as the only argument.

  206671. */

  206672. static void sqlite3Fts5ExprFree(Fts5Expr *p){

  206673.   if( p ){

  206674.     sqlite3Fts5ParseNodeFree(p->pRoot);

  206675.     sqlite3_free(p->apExprPhrase);

  206676.     sqlite3_free(p);

  206677.   }

  206678. }

  206679. 

  206680. /*

  206681. ** Argument pTerm must be a synonym iterator. Return the current rowid

  206682. ** that it points to.

  206683. */

  206684. static i64 fts5ExprSynonymRowid(Fts5ExprTerm *pTerm, int bDesc, int *pbEof){

  206685.   i64 iRet = 0;

  206686.   int bRetValid = 0;

  206687.   Fts5ExprTerm *p;

  206688. 

  206689.   assert( pTerm->pSynonym );

  206690.   assert( bDesc==0 || bDesc==1 );

  206691.   for(p=pTerm; p; p=p->pSynonym){

  206692.     if( 0==sqlite3Fts5IterEof(p->pIter) ){

  206693.       i64 iRowid = p->pIter->iRowid;

  206694.       if( bRetValid==0 || (bDesc!=(iRowid<iRet)) ){

  206695.         iRet = iRowid;

  206696.         bRetValid = 1;

  206697.       }

  206698.     }

  206699.   }

  206700. 

  206701.   if( pbEof && bRetValid==0 ) *pbEof = 1;

  206702.   return iRet;

  206703. }

  206704. 

  206705. /*

  206706. ** Argument pTerm must be a synonym iterator.

  206707. */

  206708. static int fts5ExprSynonymList(

  206709.   Fts5ExprTerm *pTerm, 

  206710.   i64 iRowid,

  206711.   Fts5Buffer *pBuf,               /* Use this buffer for space if required */

  206712.   u8 **pa, int *pn

  206713. ){

  206714.   Fts5PoslistReader aStatic[4];

  206715.   Fts5PoslistReader *aIter = aStatic;

  206716.   int nIter = 0;

  206717.   int nAlloc = 4;

  206718.   int rc = SQLITE_OK;

  206719.   Fts5ExprTerm *p;

  206720. 

  206721.   assert( pTerm->pSynonym );

  206722.   for(p=pTerm; p; p=p->pSynonym){

  206723.     Fts5IndexIter *pIter = p->pIter;

  206724.     if( sqlite3Fts5IterEof(pIter)==0 && pIter->iRowid==iRowid ){

  206725.       if( pIter->nData==0 ) continue;

  206726.       if( nIter==nAlloc ){

  206727.         sqlite3_int64 nByte = sizeof(Fts5PoslistReader) * nAlloc * 2;

  206728.         Fts5PoslistReader *aNew = (Fts5PoslistReader*)sqlite3_malloc64(nByte);

  206729.         if( aNew==0 ){

  206730.           rc = SQLITE_NOMEM;

  206731.           goto synonym_poslist_out;

  206732.         }

  206733.         memcpy(aNew, aIter, sizeof(Fts5PoslistReader) * nIter);

  206734.         nAlloc = nAlloc*2;

  206735.         if( aIter!=aStatic ) sqlite3_free(aIter);

  206736.         aIter = aNew;

  206737.       }

  206738.       sqlite3Fts5PoslistReaderInit(pIter->pData, pIter->nData, &aIter[nIter]);

  206739.       assert( aIter[nIter].bEof==0 );

  206740.       nIter++;

  206741.     }

  206742.   }

  206743. 

  206744.   if( nIter==1 ){

  206745.     *pa = (u8*)aIter[0].a;

  206746.     *pn = aIter[0].n;

  206747.   }else{

  206748.     Fts5PoslistWriter writer = {0};

  206749.     i64 iPrev = -1;

  206750.     fts5BufferZero(pBuf);

  206751.     while( 1 ){

  206752.       int i;

  206753.       i64 iMin = FTS5_LARGEST_INT64;

  206754.       for(i=0; i<nIter; i++){

  206755.         if( aIter[i].bEof==0 ){

  206756.           if( aIter[i].iPos==iPrev ){

  206757.             if( sqlite3Fts5PoslistReaderNext(&aIter[i]) ) continue;

  206758.           }

  206759.           if( aIter[i].iPos<iMin ){

  206760.             iMin = aIter[i].iPos;

  206761.           }

  206762.         }

  206763.       }

  206764.       if( iMin==FTS5_LARGEST_INT64 || rc!=SQLITE_OK ) break;

  206765.       rc = sqlite3Fts5PoslistWriterAppend(pBuf, &writer, iMin);

  206766.       iPrev = iMin;

  206767.     }

  206768.     if( rc==SQLITE_OK ){

  206769.       *pa = pBuf->p;

  206770.       *pn = pBuf->n;

  206771.     }

  206772.   }

  206773. 

  206774.  synonym_poslist_out:

  206775.   if( aIter!=aStatic ) sqlite3_free(aIter);

  206776.   return rc;

  206777. }

  206778. 

  206779. 

  206780. /*

  206781. ** All individual term iterators in pPhrase are guaranteed to be valid and

  206782. ** pointing to the same rowid when this function is called. This function 

  206783. ** checks if the current rowid really is a match, and if so populates

  206784. ** the pPhrase->poslist buffer accordingly. Output parameter *pbMatch

  206785. ** is set to true if this is really a match, or false otherwise.

  206786. **

  206787. ** SQLITE_OK is returned if an error occurs, or an SQLite error code 

  206788. ** otherwise. It is not considered an error code if the current rowid is 

  206789. ** not a match.

  206790. */

  206791. static int fts5ExprPhraseIsMatch(

  206792.   Fts5ExprNode *pNode,            /* Node pPhrase belongs to */

  206793.   Fts5ExprPhrase *pPhrase,        /* Phrase object to initialize */

  206794.   int *pbMatch                    /* OUT: Set to true if really a match */

  206795. ){

  206796.   Fts5PoslistWriter writer = {0};

  206797.   Fts5PoslistReader aStatic[4];

  206798.   Fts5PoslistReader *aIter = aStatic;

  206799.   int i;

  206800.   int rc = SQLITE_OK;

  206801.   int bFirst = pPhrase->aTerm[0].bFirst;

  206802.   

  206803.   fts5BufferZero(&pPhrase->poslist);

  206804. 

  206805.   /* If the aStatic[] array is not large enough, allocate a large array

  206806.   ** using sqlite3_malloc(). This approach could be improved upon. */

  206807.   if( pPhrase->nTerm>ArraySize(aStatic) ){

  206808.     sqlite3_int64 nByte = sizeof(Fts5PoslistReader) * pPhrase->nTerm;

  206809.     aIter = (Fts5PoslistReader*)sqlite3_malloc64(nByte);

  206810.     if( !aIter ) return SQLITE_NOMEM;

  206811.   }

  206812.   memset(aIter, 0, sizeof(Fts5PoslistReader) * pPhrase->nTerm);

  206813. 

  206814.   /* Initialize a term iterator for each term in the phrase */

  206815.   for(i=0; i<pPhrase->nTerm; i++){

  206816.     Fts5ExprTerm *pTerm = &pPhrase->aTerm[i];

  206817.     int n = 0;

  206818.     int bFlag = 0;

  206819.     u8 *a = 0;

  206820.     if( pTerm->pSynonym ){

  206821.       Fts5Buffer buf = {0, 0, 0};

  206822.       rc = fts5ExprSynonymList(pTerm, pNode->iRowid, &buf, &a, &n);

  206823.       if( rc ){

  206824.         sqlite3_free(a);

  206825.         goto ismatch_out;

  206826.       }

  206827.       if( a==buf.p ) bFlag = 1;

  206828.     }else{

  206829.       a = (u8*)pTerm->pIter->pData;

  206830.       n = pTerm->pIter->nData;

  206831.     }

  206832.     sqlite3Fts5PoslistReaderInit(a, n, &aIter[i]);

  206833.     aIter[i].bFlag = (u8)bFlag;

  206834.     if( aIter[i].bEof ) goto ismatch_out;

  206835.   }

  206836. 

  206837.   while( 1 ){

  206838.     int bMatch;

  206839.     i64 iPos = aIter[0].iPos;

  206840.     do {

  206841.       bMatch = 1;

  206842.       for(i=0; i<pPhrase->nTerm; i++){

  206843.         Fts5PoslistReader *pPos = &aIter[i];

  206844.         i64 iAdj = iPos + i;

  206845.         if( pPos->iPos!=iAdj ){

  206846.           bMatch = 0;

  206847.           while( pPos->iPos<iAdj ){

  206848.             if( sqlite3Fts5PoslistReaderNext(pPos) ) goto ismatch_out;

  206849.           }

  206850.           if( pPos->iPos>iAdj ) iPos = pPos->iPos-i;

  206851.         }

  206852.       }

  206853.     }while( bMatch==0 );

  206854. 

  206855.     /* Append position iPos to the output */

  206856.     if( bFirst==0 || FTS5_POS2OFFSET(iPos)==0 ){

  206857.       rc = sqlite3Fts5PoslistWriterAppend(&pPhrase->poslist, &writer, iPos);

  206858.       if( rc!=SQLITE_OK ) goto ismatch_out;

  206859.     }

  206860. 

  206861.     for(i=0; i<pPhrase->nTerm; i++){

  206862.       if( sqlite3Fts5PoslistReaderNext(&aIter[i]) ) goto ismatch_out;

  206863.     }

  206864.   }

  206865. 

  206866.  ismatch_out:

  206867.   *pbMatch = (pPhrase->poslist.n>0);

  206868.   for(i=0; i<pPhrase->nTerm; i++){

  206869.     if( aIter[i].bFlag ) sqlite3_free((u8*)aIter[i].a);

  206870.   }

  206871.   if( aIter!=aStatic ) sqlite3_free(aIter);

  206872.   return rc;

  206873. }

  206874. 

  206875. typedef struct Fts5LookaheadReader Fts5LookaheadReader;

  206876. struct Fts5LookaheadReader {

  206877.   const u8 *a;                    /* Buffer containing position list */

  206878.   int n;                          /* Size of buffer a[] in bytes */

  206879.   int i;                          /* Current offset in position list */

  206880.   i64 iPos;                       /* Current position */

  206881.   i64 iLookahead;                 /* Next position */

  206882. };

  206883. 

  206884. #define FTS5_LOOKAHEAD_EOF (((i64)1) << 62)

  206885. 

  206886. static int fts5LookaheadReaderNext(Fts5LookaheadReader *p){

  206887.   p->iPos = p->iLookahead;

  206888.   if( sqlite3Fts5PoslistNext64(p->a, p->n, &p->i, &p->iLookahead) ){

  206889.     p->iLookahead = FTS5_LOOKAHEAD_EOF;

  206890.   }

  206891.   return (p->iPos==FTS5_LOOKAHEAD_EOF);

  206892. }

  206893. 

  206894. static int fts5LookaheadReaderInit(

  206895.   const u8 *a, int n,             /* Buffer to read position list from */

  206896.   Fts5LookaheadReader *p          /* Iterator object to initialize */

  206897. ){

  206898.   memset(p, 0, sizeof(Fts5LookaheadReader));

  206899.   p->a = a;

  206900.   p->n = n;

  206901.   fts5LookaheadReaderNext(p);

  206902.   return fts5LookaheadReaderNext(p);

  206903. }

  206904. 

  206905. typedef struct Fts5NearTrimmer Fts5NearTrimmer;

  206906. struct Fts5NearTrimmer {

  206907.   Fts5LookaheadReader reader;     /* Input iterator */

  206908.   Fts5PoslistWriter writer;       /* Writer context */

  206909.   Fts5Buffer *pOut;               /* Output poslist */

  206910. };

  206911. 

  206912. /*

  206913. ** The near-set object passed as the first argument contains more than

  206914. ** one phrase. All phrases currently point to the same row. The

  206915. ** Fts5ExprPhrase.poslist buffers are populated accordingly. This function

  206916. ** tests if the current row contains instances of each phrase sufficiently

  206917. ** close together to meet the NEAR constraint. Non-zero is returned if it

  206918. ** does, or zero otherwise.

  206919. **

  206920. ** If in/out parameter (*pRc) is set to other than SQLITE_OK when this

  206921. ** function is called, it is a no-op. Or, if an error (e.g. SQLITE_NOMEM)

  206922. ** occurs within this function (*pRc) is set accordingly before returning.

  206923. ** The return value is undefined in both these cases.

  206924. ** 

  206925. ** If no error occurs and non-zero (a match) is returned, the position-list

  206926. ** of each phrase object is edited to contain only those entries that

  206927. ** meet the constraint before returning.

  206928. */

  206929. static int fts5ExprNearIsMatch(int *pRc, Fts5ExprNearset *pNear){

  206930.   Fts5NearTrimmer aStatic[4];

  206931.   Fts5NearTrimmer *a = aStatic;

  206932.   Fts5ExprPhrase **apPhrase = pNear->apPhrase;

  206933. 

  206934.   int i;

  206935.   int rc = *pRc;

  206936.   int bMatch;

  206937. 

  206938.   assert( pNear->nPhrase>1 );

  206939. 

  206940.   /* If the aStatic[] array is not large enough, allocate a large array

  206941.   ** using sqlite3_malloc(). This approach could be improved upon. */

  206942.   if( pNear->nPhrase>ArraySize(aStatic) ){

  206943.     sqlite3_int64 nByte = sizeof(Fts5NearTrimmer) * pNear->nPhrase;

  206944.     a = (Fts5NearTrimmer*)sqlite3Fts5MallocZero(&rc, nByte);

  206945.   }else{

  206946.     memset(aStatic, 0, sizeof(aStatic));

  206947.   }

  206948.   if( rc!=SQLITE_OK ){

  206949.     *pRc = rc;

  206950.     return 0;

  206951.   }

  206952. 

  206953.   /* Initialize a lookahead iterator for each phrase. After passing the

  206954.   ** buffer and buffer size to the lookaside-reader init function, zero

  206955.   ** the phrase poslist buffer. The new poslist for the phrase (containing

  206956.   ** the same entries as the original with some entries removed on account 

  206957.   ** of the NEAR constraint) is written over the original even as it is

  206958.   ** being read. This is safe as the entries for the new poslist are a

  206959.   ** subset of the old, so it is not possible for data yet to be read to

  206960.   ** be overwritten.  */

  206961.   for(i=0; i<pNear->nPhrase; i++){

  206962.     Fts5Buffer *pPoslist = &apPhrase[i]->poslist;

  206963.     fts5LookaheadReaderInit(pPoslist->p, pPoslist->n, &a[i].reader);

  206964.     pPoslist->n = 0;

  206965.     a[i].pOut = pPoslist;

  206966.   }

  206967. 

  206968.   while( 1 ){

  206969.     int iAdv;

  206970.     i64 iMin;

  206971.     i64 iMax;

  206972. 

  206973.     /* This block advances the phrase iterators until they point to a set of

  206974.     ** entries that together comprise a match.  */

  206975.     iMax = a[0].reader.iPos;

  206976.     do {

  206977.       bMatch = 1;

  206978.       for(i=0; i<pNear->nPhrase; i++){

  206979.         Fts5LookaheadReader *pPos = &a[i].reader;

  206980.         iMin = iMax - pNear->apPhrase[i]->nTerm - pNear->nNear;

  206981.         if( pPos->iPos<iMin || pPos->iPos>iMax ){

  206982.           bMatch = 0;

  206983.           while( pPos->iPos<iMin ){

  206984.             if( fts5LookaheadReaderNext(pPos) ) goto ismatch_out;

  206985.           }

  206986.           if( pPos->iPos>iMax ) iMax = pPos->iPos;

  206987.         }

  206988.       }

  206989.     }while( bMatch==0 );

  206990. 

  206991.     /* Add an entry to each output position list */

  206992.     for(i=0; i<pNear->nPhrase; i++){

  206993.       i64 iPos = a[i].reader.iPos;

  206994.       Fts5PoslistWriter *pWriter = &a[i].writer;

  206995.       if( a[i].pOut->n==0 || iPos!=pWriter->iPrev ){

  206996.         sqlite3Fts5PoslistWriterAppend(a[i].pOut, pWriter, iPos);

  206997.       }

  206998.     }

  206999. 

  207000.     iAdv = 0;

  207001.     iMin = a[0].reader.iLookahead;

  207002.     for(i=0; i<pNear->nPhrase; i++){

  207003.       if( a[i].reader.iLookahead < iMin ){

  207004.         iMin = a[i].reader.iLookahead;

  207005.         iAdv = i;

  207006.       }

  207007.     }

  207008.     if( fts5LookaheadReaderNext(&a[iAdv].reader) ) goto ismatch_out;

  207009.   }

  207010. 

  207011.   ismatch_out: {

  207012.     int bRet = a[0].pOut->n>0;

  207013.     *pRc = rc;

  207014.     if( a!=aStatic ) sqlite3_free(a);

  207015.     return bRet;

  207016.   }

  207017. }

  207018. 

  207019. /*

  207020. ** Advance iterator pIter until it points to a value equal to or laster

  207021. ** than the initial value of *piLast. If this means the iterator points

  207022. ** to a value laster than *piLast, update *piLast to the new lastest value.

  207023. **

  207024. ** If the iterator reaches EOF, set *pbEof to true before returning. If

  207025. ** an error occurs, set *pRc to an error code. If either *pbEof or *pRc

  207026. ** are set, return a non-zero value. Otherwise, return zero.

  207027. */

  207028. static int fts5ExprAdvanceto(

  207029.   Fts5IndexIter *pIter,           /* Iterator to advance */

  207030.   int bDesc,                      /* True if iterator is "rowid DESC" */

  207031.   i64 *piLast,                    /* IN/OUT: Lastest rowid seen so far */

  207032.   int *pRc,                       /* OUT: Error code */

  207033.   int *pbEof                      /* OUT: Set to true if EOF */

  207034. ){

  207035.   i64 iLast = *piLast;

  207036.   i64 iRowid;

  207037. 

  207038.   iRowid = pIter->iRowid;

  207039.   if( (bDesc==0 && iLast>iRowid) || (bDesc && iLast<iRowid) ){

  207040.     int rc = sqlite3Fts5IterNextFrom(pIter, iLast);

  207041.     if( rc || sqlite3Fts5IterEof(pIter) ){

  207042.       *pRc = rc;

  207043.       *pbEof = 1;

  207044.       return 1;

  207045.     }

  207046.     iRowid = pIter->iRowid;

  207047.     assert( (bDesc==0 && iRowid>=iLast) || (bDesc==1 && iRowid<=iLast) );

  207048.   }

  207049.   *piLast = iRowid;

  207050. 

  207051.   return 0;

  207052. }

  207053. 

  207054. static int fts5ExprSynonymAdvanceto(

  207055.   Fts5ExprTerm *pTerm,            /* Term iterator to advance */

  207056.   int bDesc,                      /* True if iterator is "rowid DESC" */

  207057.   i64 *piLast,                    /* IN/OUT: Lastest rowid seen so far */

  207058.   int *pRc                        /* OUT: Error code */

  207059. ){

  207060.   int rc = SQLITE_OK;

  207061.   i64 iLast = *piLast;

  207062.   Fts5ExprTerm *p;

  207063.   int bEof = 0;

  207064. 

  207065.   for(p=pTerm; rc==SQLITE_OK && p; p=p->pSynonym){

  207066.     if( sqlite3Fts5IterEof(p->pIter)==0 ){

  207067.       i64 iRowid = p->pIter->iRowid;

  207068.       if( (bDesc==0 && iLast>iRowid) || (bDesc && iLast<iRowid) ){

  207069.         rc = sqlite3Fts5IterNextFrom(p->pIter, iLast);

  207070.       }

  207071.     }

  207072.   }

  207073. 

  207074.   if( rc!=SQLITE_OK ){

  207075.     *pRc = rc;

  207076.     bEof = 1;

  207077.   }else{

  207078.     *piLast = fts5ExprSynonymRowid(pTerm, bDesc, &bEof);

  207079.   }

  207080.   return bEof;

  207081. }

  207082. 

  207083. 

  207084. static int fts5ExprNearTest(

  207085.   int *pRc,

  207086.   Fts5Expr *pExpr,                /* Expression that pNear is a part of */

  207087.   Fts5ExprNode *pNode             /* The "NEAR" node (FTS5_STRING) */

  207088. ){

  207089.   Fts5ExprNearset *pNear = pNode->pNear;

  207090.   int rc = *pRc;

  207091. 

  207092.   if( pExpr->pConfig->eDetail!=FTS5_DETAIL_FULL ){

  207093.     Fts5ExprTerm *pTerm;

  207094.     Fts5ExprPhrase *pPhrase = pNear->apPhrase[0];

  207095.     pPhrase->poslist.n = 0;

  207096.     for(pTerm=&pPhrase->aTerm[0]; pTerm; pTerm=pTerm->pSynonym){

  207097.       Fts5IndexIter *pIter = pTerm->pIter;

  207098.       if( sqlite3Fts5IterEof(pIter)==0 ){

  207099.         if( pIter->iRowid==pNode->iRowid && pIter->nData>0 ){

  207100.           pPhrase->poslist.n = 1;

  207101.         }

  207102.       }

  207103.     }

  207104.     return pPhrase->poslist.n;

  207105.   }else{

  207106.     int i;

  207107. 

  207108.     /* Check that each phrase in the nearset matches the current row.

  207109.     ** Populate the pPhrase->poslist buffers at the same time. If any

  207110.     ** phrase is not a match, break out of the loop early.  */

  207111.     for(i=0; rc==SQLITE_OK && i<pNear->nPhrase; i++){

  207112.       Fts5ExprPhrase *pPhrase = pNear->apPhrase[i];

  207113.       if( pPhrase->nTerm>1 || pPhrase->aTerm[0].pSynonym 

  207114.        || pNear->pColset || pPhrase->aTerm[0].bFirst

  207115.       ){

  207116.         int bMatch = 0;

  207117.         rc = fts5ExprPhraseIsMatch(pNode, pPhrase, &bMatch);

  207118.         if( bMatch==0 ) break;

  207119.       }else{

  207120.         Fts5IndexIter *pIter = pPhrase->aTerm[0].pIter;

  207121.         fts5BufferSet(&rc, &pPhrase->poslist, pIter->nData, pIter->pData);

  207122.       }

  207123.     }

  207124. 

  207125.     *pRc = rc;

  207126.     if( i==pNear->nPhrase && (i==1 || fts5ExprNearIsMatch(pRc, pNear)) ){

  207127.       return 1;

  207128.     }

  207129.     return 0;

  207130.   }

  207131. }

  207132. 

  207133. 

  207134. /*

  207135. ** Initialize all term iterators in the pNear object. If any term is found

  207136. ** to match no documents at all, return immediately without initializing any

  207137. ** further iterators.

  207138. **

  207139. ** If an error occurs, return an SQLite error code. Otherwise, return

  207140. ** SQLITE_OK. It is not considered an error if some term matches zero

  207141. ** documents.

  207142. */

  207143. static int fts5ExprNearInitAll(

  207144.   Fts5Expr *pExpr,

  207145.   Fts5ExprNode *pNode

  207146. ){

  207147.   Fts5ExprNearset *pNear = pNode->pNear;

  207148.   int i;

  207149. 

  207150.   assert( pNode->bNomatch==0 );

  207151.   for(i=0; i<pNear->nPhrase; i++){

  207152.     Fts5ExprPhrase *pPhrase = pNear->apPhrase[i];

  207153.     if( pPhrase->nTerm==0 ){

  207154.       pNode->bEof = 1;

  207155.       return SQLITE_OK;

  207156.     }else{

  207157.       int j;

  207158.       for(j=0; j<pPhrase->nTerm; j++){

  207159.         Fts5ExprTerm *pTerm = &pPhrase->aTerm[j];

  207160.         Fts5ExprTerm *p;

  207161.         int bHit = 0;

  207162. 

  207163.         for(p=pTerm; p; p=p->pSynonym){

  207164.           int rc;

  207165.           if( p->pIter ){

  207166.             sqlite3Fts5IterClose(p->pIter);

  207167.             p->pIter = 0;

  207168.           }

  207169.           rc = sqlite3Fts5IndexQuery(

  207170.               pExpr->pIndex, p->zTerm, (int)strlen(p->zTerm),

  207171.               (pTerm->bPrefix ? FTS5INDEX_QUERY_PREFIX : 0) |

  207172.               (pExpr->bDesc ? FTS5INDEX_QUERY_DESC : 0),

  207173.               pNear->pColset,

  207174.               &p->pIter

  207175.           );

  207176.           assert( (rc==SQLITE_OK)==(p->pIter!=0) );

  207177.           if( rc!=SQLITE_OK ) return rc;

  207178.           if( 0==sqlite3Fts5IterEof(p->pIter) ){

  207179.             bHit = 1;

  207180.           }

  207181.         }

  207182. 

  207183.         if( bHit==0 ){

  207184.           pNode->bEof = 1;

  207185.           return SQLITE_OK;

  207186.         }

  207187.       }

  207188.     }

  207189.   }

  207190. 

  207191.   pNode->bEof = 0;

  207192.   return SQLITE_OK;

  207193. }

  207194. 

  207195. /*

  207196. ** If pExpr is an ASC iterator, this function returns a value with the

  207197. ** same sign as:

  207198. **

  207199. **   (iLhs - iRhs)

  207200. **

  207201. ** Otherwise, if this is a DESC iterator, the opposite is returned:

  207202. **

  207203. **   (iRhs - iLhs)

  207204. */

  207205. static int fts5RowidCmp(

  207206.   Fts5Expr *pExpr,

  207207.   i64 iLhs,

  207208.   i64 iRhs

  207209. ){

  207210.   assert( pExpr->bDesc==0 || pExpr->bDesc==1 );

  207211.   if( pExpr->bDesc==0 ){

  207212.     if( iLhs<iRhs ) return -1;

  207213.     return (iLhs > iRhs);

  207214.   }else{

  207215.     if( iLhs>iRhs ) return -1;

  207216.     return (iLhs < iRhs);

  207217.   }

  207218. }

  207219. 

  207220. static void fts5ExprSetEof(Fts5ExprNode *pNode){

  207221.   int i;

  207222.   pNode->bEof = 1;

  207223.   pNode->bNomatch = 0;

  207224.   for(i=0; i<pNode->nChild; i++){

  207225.     fts5ExprSetEof(pNode->apChild[i]);

  207226.   }

  207227. }

  207228. 

  207229. static void fts5ExprNodeZeroPoslist(Fts5ExprNode *pNode){

  207230.   if( pNode->eType==FTS5_STRING || pNode->eType==FTS5_TERM ){

  207231.     Fts5ExprNearset *pNear = pNode->pNear;

  207232.     int i;

  207233.     for(i=0; i<pNear->nPhrase; i++){

  207234.       Fts5ExprPhrase *pPhrase = pNear->apPhrase[i];

  207235.       pPhrase->poslist.n = 0;

  207236.     }

  207237.   }else{

  207238.     int i;

  207239.     for(i=0; i<pNode->nChild; i++){

  207240.       fts5ExprNodeZeroPoslist(pNode->apChild[i]);

  207241.     }

  207242.   }

  207243. }

  207244. 

  207245. 

  207246. 

  207247. /*

  207248. ** Compare the values currently indicated by the two nodes as follows:

  207249. **

  207250. **    res = (*p1) - (*p2)

  207251. **

  207252. ** Nodes that point to values that come later in the iteration order are

  207253. ** considered to be larger. Nodes at EOF are the largest of all.

  207254. **

  207255. ** This means that if the iteration order is ASC, then numerically larger

  207256. ** rowids are considered larger. Or if it is the default DESC, numerically

  207257. ** smaller rowids are larger.

  207258. */

  207259. static int fts5NodeCompare(

  207260.   Fts5Expr *pExpr,

  207261.   Fts5ExprNode *p1, 

  207262.   Fts5ExprNode *p2

  207263. ){

  207264.   if( p2->bEof ) return -1;

  207265.   if( p1->bEof ) return +1;

  207266.   return fts5RowidCmp(pExpr, p1->iRowid, p2->iRowid);

  207267. }

  207268. 

  207269. /*

  207270. ** All individual term iterators in pNear are guaranteed to be valid when

  207271. ** this function is called. This function checks if all term iterators

  207272. ** point to the same rowid, and if not, advances them until they do.

  207273. ** If an EOF is reached before this happens, *pbEof is set to true before

  207274. ** returning.

  207275. **

  207276. ** SQLITE_OK is returned if an error occurs, or an SQLite error code 

  207277. ** otherwise. It is not considered an error code if an iterator reaches

  207278. ** EOF.

  207279. */

  207280. static int fts5ExprNodeTest_STRING(

  207281.   Fts5Expr *pExpr,                /* Expression pPhrase belongs to */

  207282.   Fts5ExprNode *pNode

  207283. ){

  207284.   Fts5ExprNearset *pNear = pNode->pNear;

  207285.   Fts5ExprPhrase *pLeft = pNear->apPhrase[0];

  207286.   int rc = SQLITE_OK;

  207287.   i64 iLast;                      /* Lastest rowid any iterator points to */

  207288.   int i, j;                       /* Phrase and token index, respectively */

  207289.   int bMatch;                     /* True if all terms are at the same rowid */

  207290.   const int bDesc = pExpr->bDesc;

  207291. 

  207292.   /* Check that this node should not be FTS5_TERM */

  207293.   assert( pNear->nPhrase>1 

  207294.        || pNear->apPhrase[0]->nTerm>1 

  207295.        || pNear->apPhrase[0]->aTerm[0].pSynonym

  207296.        || pNear->apPhrase[0]->aTerm[0].bFirst

  207297.   );

  207298. 

  207299.   /* Initialize iLast, the "lastest" rowid any iterator points to. If the

  207300.   ** iterator skips through rowids in the default ascending order, this means

  207301.   ** the maximum rowid. Or, if the iterator is "ORDER BY rowid DESC", then it

  207302.   ** means the minimum rowid.  */

  207303.   if( pLeft->aTerm[0].pSynonym ){

  207304.     iLast = fts5ExprSynonymRowid(&pLeft->aTerm[0], bDesc, 0);

  207305.   }else{

  207306.     iLast = pLeft->aTerm[0].pIter->iRowid;

  207307.   }

  207308. 

  207309.   do {

  207310.     bMatch = 1;

  207311.     for(i=0; i<pNear->nPhrase; i++){

  207312.       Fts5ExprPhrase *pPhrase = pNear->apPhrase[i];

  207313.       for(j=0; j<pPhrase->nTerm; j++){

  207314.         Fts5ExprTerm *pTerm = &pPhrase->aTerm[j];

  207315.         if( pTerm->pSynonym ){

  207316.           i64 iRowid = fts5ExprSynonymRowid(pTerm, bDesc, 0);

  207317.           if( iRowid==iLast ) continue;

  207318.           bMatch = 0;

  207319.           if( fts5ExprSynonymAdvanceto(pTerm, bDesc, &iLast, &rc) ){

  207320.             pNode->bNomatch = 0;

  207321.             pNode->bEof = 1;

  207322.             return rc;

  207323.           }

  207324.         }else{

  207325.           Fts5IndexIter *pIter = pPhrase->aTerm[j].pIter;

  207326.           if( pIter->iRowid==iLast || pIter->bEof ) continue;

  207327.           bMatch = 0;

  207328.           if( fts5ExprAdvanceto(pIter, bDesc, &iLast, &rc, &pNode->bEof) ){

  207329.             return rc;

  207330.           }

  207331.         }

  207332.       }

  207333.     }

  207334.   }while( bMatch==0 );

  207335. 

  207336.   pNode->iRowid = iLast;

  207337.   pNode->bNomatch = ((0==fts5ExprNearTest(&rc, pExpr, pNode)) && rc==SQLITE_OK);

  207338.   assert( pNode->bEof==0 || pNode->bNomatch==0 );

  207339. 

  207340.   return rc;

  207341. }

  207342. 

  207343. /*

  207344. ** Advance the first term iterator in the first phrase of pNear. Set output

  207345. ** variable *pbEof to true if it reaches EOF or if an error occurs.

  207346. **

  207347. ** Return SQLITE_OK if successful, or an SQLite error code if an error

  207348. ** occurs.

  207349. */

  207350. static int fts5ExprNodeNext_STRING(

  207351.   Fts5Expr *pExpr,                /* Expression pPhrase belongs to */

  207352.   Fts5ExprNode *pNode,            /* FTS5_STRING or FTS5_TERM node */

  207353.   int bFromValid,

  207354.   i64 iFrom 

  207355. ){

  207356.   Fts5ExprTerm *pTerm = &pNode->pNear->apPhrase[0]->aTerm[0];

  207357.   int rc = SQLITE_OK;

  207358. 

  207359.   pNode->bNomatch = 0;

  207360.   if( pTerm->pSynonym ){

  207361.     int bEof = 1;

  207362.     Fts5ExprTerm *p;

  207363. 

  207364.     /* Find the firstest rowid any synonym points to. */

  207365.     i64 iRowid = fts5ExprSynonymRowid(pTerm, pExpr->bDesc, 0);

  207366. 

  207367.     /* Advance each iterator that currently points to iRowid. Or, if iFrom

  207368.     ** is valid - each iterator that points to a rowid before iFrom.  */

  207369.     for(p=pTerm; p; p=p->pSynonym){

  207370.       if( sqlite3Fts5IterEof(p->pIter)==0 ){

  207371.         i64 ii = p->pIter->iRowid;

  207372.         if( ii==iRowid 

  207373.          || (bFromValid && ii!=iFrom && (ii>iFrom)==pExpr->bDesc) 

  207374.         ){

  207375.           if( bFromValid ){

  207376.             rc = sqlite3Fts5IterNextFrom(p->pIter, iFrom);

  207377.           }else{

  207378.             rc = sqlite3Fts5IterNext(p->pIter);

  207379.           }

  207380.           if( rc!=SQLITE_OK ) break;

  207381.           if( sqlite3Fts5IterEof(p->pIter)==0 ){

  207382.             bEof = 0;

  207383.           }

  207384.         }else{

  207385.           bEof = 0;

  207386.         }

  207387.       }

  207388.     }

  207389. 

  207390.     /* Set the EOF flag if either all synonym iterators are at EOF or an

  207391.     ** error has occurred.  */

  207392.     pNode->bEof = (rc || bEof);

  207393.   }else{

  207394.     Fts5IndexIter *pIter = pTerm->pIter;

  207395. 

  207396.     assert( Fts5NodeIsString(pNode) );

  207397.     if( bFromValid ){

  207398.       rc = sqlite3Fts5IterNextFrom(pIter, iFrom);

  207399.     }else{

  207400.       rc = sqlite3Fts5IterNext(pIter);

  207401.     }

  207402. 

  207403.     pNode->bEof = (rc || sqlite3Fts5IterEof(pIter));

  207404.   }

  207405. 

  207406.   if( pNode->bEof==0 ){

  207407.     assert( rc==SQLITE_OK );

  207408.     rc = fts5ExprNodeTest_STRING(pExpr, pNode);

  207409.   }

  207410. 

  207411.   return rc;

  207412. }

  207413. 

  207414. 

  207415. static int fts5ExprNodeTest_TERM(

  207416.   Fts5Expr *pExpr,                /* Expression that pNear is a part of */

  207417.   Fts5ExprNode *pNode             /* The "NEAR" node (FTS5_TERM) */

  207418. ){

  207419.   /* As this "NEAR" object is actually a single phrase that consists 

  207420.   ** of a single term only, grab pointers into the poslist managed by the

  207421.   ** fts5_index.c iterator object. This is much faster than synthesizing 

  207422.   ** a new poslist the way we have to for more complicated phrase or NEAR

  207423.   ** expressions.  */

  207424.   Fts5ExprPhrase *pPhrase = pNode->pNear->apPhrase[0];

  207425.   Fts5IndexIter *pIter = pPhrase->aTerm[0].pIter;

  207426. 

  207427.   assert( pNode->eType==FTS5_TERM );

  207428.   assert( pNode->pNear->nPhrase==1 && pPhrase->nTerm==1 );

  207429.   assert( pPhrase->aTerm[0].pSynonym==0 );

  207430. 

  207431.   pPhrase->poslist.n = pIter->nData;

  207432.   if( pExpr->pConfig->eDetail==FTS5_DETAIL_FULL ){

  207433.     pPhrase->poslist.p = (u8*)pIter->pData;

  207434.   }

  207435.   pNode->iRowid = pIter->iRowid;

  207436.   pNode->bNomatch = (pPhrase->poslist.n==0);

  207437.   return SQLITE_OK;

  207438. }

  207439. 

  207440. /*

  207441. ** xNext() method for a node of type FTS5_TERM.

  207442. */

  207443. static int fts5ExprNodeNext_TERM(

  207444.   Fts5Expr *pExpr, 

  207445.   Fts5ExprNode *pNode,

  207446.   int bFromValid,

  207447.   i64 iFrom

  207448. ){

  207449.   int rc;

  207450.   Fts5IndexIter *pIter = pNode->pNear->apPhrase[0]->aTerm[0].pIter;

  207451. 

  207452.   assert( pNode->bEof==0 );

  207453.   if( bFromValid ){

  207454.     rc = sqlite3Fts5IterNextFrom(pIter, iFrom);

  207455.   }else{

  207456.     rc = sqlite3Fts5IterNext(pIter);

  207457.   }

  207458.   if( rc==SQLITE_OK && sqlite3Fts5IterEof(pIter)==0 ){

  207459.     rc = fts5ExprNodeTest_TERM(pExpr, pNode);

  207460.   }else{

  207461.     pNode->bEof = 1;

  207462.     pNode->bNomatch = 0;

  207463.   }

  207464.   return rc;

  207465. }

  207466. 

  207467. static void fts5ExprNodeTest_OR(

  207468.   Fts5Expr *pExpr,                /* Expression of which pNode is a part */

  207469.   Fts5ExprNode *pNode             /* Expression node to test */

  207470. ){

  207471.   Fts5ExprNode *pNext = pNode->apChild[0];

  207472.   int i;

  207473. 

  207474.   for(i=1; i<pNode->nChild; i++){

  207475.     Fts5ExprNode *pChild = pNode->apChild[i];

  207476.     int cmp = fts5NodeCompare(pExpr, pNext, pChild);

  207477.     if( cmp>0 || (cmp==0 && pChild->bNomatch==0) ){

  207478.       pNext = pChild;

  207479.     }

  207480.   }

  207481.   pNode->iRowid = pNext->iRowid;

  207482.   pNode->bEof = pNext->bEof;

  207483.   pNode->bNomatch = pNext->bNomatch;

  207484. }

  207485. 

  207486. static int fts5ExprNodeNext_OR(

  207487.   Fts5Expr *pExpr, 

  207488.   Fts5ExprNode *pNode,

  207489.   int bFromValid,

  207490.   i64 iFrom

  207491. ){

  207492.   int i;

  207493.   i64 iLast = pNode->iRowid;

  207494. 

  207495.   for(i=0; i<pNode->nChild; i++){

  207496.     Fts5ExprNode *p1 = pNode->apChild[i];

  207497.     assert( p1->bEof || fts5RowidCmp(pExpr, p1->iRowid, iLast)>=0 );

  207498.     if( p1->bEof==0 ){

  207499.       if( (p1->iRowid==iLast) 

  207500.        || (bFromValid && fts5RowidCmp(pExpr, p1->iRowid, iFrom)<0)

  207501.       ){

  207502.         int rc = fts5ExprNodeNext(pExpr, p1, bFromValid, iFrom);

  207503.         if( rc!=SQLITE_OK ){

  207504.           pNode->bNomatch = 0;

  207505.           return rc;

  207506.         }

  207507.       }

  207508.     }

  207509.   }

  207510. 

  207511.   fts5ExprNodeTest_OR(pExpr, pNode);

  207512.   return SQLITE_OK;

  207513. }

  207514. 

  207515. /*

  207516. ** Argument pNode is an FTS5_AND node.

  207517. */

  207518. static int fts5ExprNodeTest_AND(

  207519.   Fts5Expr *pExpr,                /* Expression pPhrase belongs to */

  207520.   Fts5ExprNode *pAnd              /* FTS5_AND node to advance */

  207521. ){

  207522.   int iChild;

  207523.   i64 iLast = pAnd->iRowid;

  207524.   int rc = SQLITE_OK;

  207525.   int bMatch;

  207526. 

  207527.   assert( pAnd->bEof==0 );

  207528.   do {

  207529.     pAnd->bNomatch = 0;

  207530.     bMatch = 1;

  207531.     for(iChild=0; iChild<pAnd->nChild; iChild++){

  207532.       Fts5ExprNode *pChild = pAnd->apChild[iChild];

  207533.       int cmp = fts5RowidCmp(pExpr, iLast, pChild->iRowid);

  207534.       if( cmp>0 ){

  207535.         /* Advance pChild until it points to iLast or laster */

  207536.         rc = fts5ExprNodeNext(pExpr, pChild, 1, iLast);

  207537.         if( rc!=SQLITE_OK ){

  207538.           pAnd->bNomatch = 0;

  207539.           return rc;

  207540.         }

  207541.       }

  207542. 

  207543.       /* If the child node is now at EOF, so is the parent AND node. Otherwise,

  207544.       ** the child node is guaranteed to have advanced at least as far as

  207545.       ** rowid iLast. So if it is not at exactly iLast, pChild->iRowid is the

  207546.       ** new lastest rowid seen so far.  */

  207547.       assert( pChild->bEof || fts5RowidCmp(pExpr, iLast, pChild->iRowid)<=0 );

  207548.       if( pChild->bEof ){

  207549.         fts5ExprSetEof(pAnd);

  207550.         bMatch = 1;

  207551.         break;

  207552.       }else if( iLast!=pChild->iRowid ){

  207553.         bMatch = 0;

  207554.         iLast = pChild->iRowid;

  207555.       }

  207556. 

  207557.       if( pChild->bNomatch ){

  207558.         pAnd->bNomatch = 1;

  207559.       }

  207560.     }

  207561.   }while( bMatch==0 );

  207562. 

  207563.   if( pAnd->bNomatch && pAnd!=pExpr->pRoot ){

  207564.     fts5ExprNodeZeroPoslist(pAnd);

  207565.   }

  207566.   pAnd->iRowid = iLast;

  207567.   return SQLITE_OK;

  207568. }

  207569. 

  207570. static int fts5ExprNodeNext_AND(

  207571.   Fts5Expr *pExpr, 

  207572.   Fts5ExprNode *pNode,

  207573.   int bFromValid,

  207574.   i64 iFrom

  207575. ){

  207576.   int rc = fts5ExprNodeNext(pExpr, pNode->apChild[0], bFromValid, iFrom);

  207577.   if( rc==SQLITE_OK ){

  207578.     rc = fts5ExprNodeTest_AND(pExpr, pNode);

  207579.   }else{

  207580.     pNode->bNomatch = 0;

  207581.   }

  207582.   return rc;

  207583. }

  207584. 

  207585. static int fts5ExprNodeTest_NOT(

  207586.   Fts5Expr *pExpr,                /* Expression pPhrase belongs to */

  207587.   Fts5ExprNode *pNode             /* FTS5_NOT node to advance */

  207588. ){

  207589.   int rc = SQLITE_OK;

  207590.   Fts5ExprNode *p1 = pNode->apChild[0];

  207591.   Fts5ExprNode *p2 = pNode->apChild[1];

  207592.   assert( pNode->nChild==2 );

  207593. 

  207594.   while( rc==SQLITE_OK && p1->bEof==0 ){

  207595.     int cmp = fts5NodeCompare(pExpr, p1, p2);

  207596.     if( cmp>0 ){

  207597.       rc = fts5ExprNodeNext(pExpr, p2, 1, p1->iRowid);

  207598.       cmp = fts5NodeCompare(pExpr, p1, p2);

  207599.     }

  207600.     assert( rc!=SQLITE_OK || cmp<=0 );

  207601.     if( cmp || p2->bNomatch ) break;

  207602.     rc = fts5ExprNodeNext(pExpr, p1, 0, 0);

  207603.   }

  207604.   pNode->bEof = p1->bEof;

  207605.   pNode->bNomatch = p1->bNomatch;

  207606.   pNode->iRowid = p1->iRowid;

  207607.   if( p1->bEof ){

  207608.     fts5ExprNodeZeroPoslist(p2);

  207609.   }

  207610.   return rc;

  207611. }

  207612. 

  207613. static int fts5ExprNodeNext_NOT(

  207614.   Fts5Expr *pExpr, 

  207615.   Fts5ExprNode *pNode,

  207616.   int bFromValid,

  207617.   i64 iFrom

  207618. ){

  207619.   int rc = fts5ExprNodeNext(pExpr, pNode->apChild[0], bFromValid, iFrom);

  207620.   if( rc==SQLITE_OK ){

  207621.     rc = fts5ExprNodeTest_NOT(pExpr, pNode);

  207622.   }

  207623.   if( rc!=SQLITE_OK ){

  207624.     pNode->bNomatch = 0;

  207625.   }

  207626.   return rc;

  207627. }

  207628. 

  207629. /*

  207630. ** If pNode currently points to a match, this function returns SQLITE_OK

  207631. ** without modifying it. Otherwise, pNode is advanced until it does point

  207632. ** to a match or EOF is reached.

  207633. */

  207634. static int fts5ExprNodeTest(

  207635.   Fts5Expr *pExpr,                /* Expression of which pNode is a part */

  207636.   Fts5ExprNode *pNode             /* Expression node to test */

  207637. ){

  207638.   int rc = SQLITE_OK;

  207639.   if( pNode->bEof==0 ){

  207640.     switch( pNode->eType ){

  207641. 

  207642.       case FTS5_STRING: {

  207643.         rc = fts5ExprNodeTest_STRING(pExpr, pNode);

  207644.         break;

  207645.       }

  207646. 

  207647.       case FTS5_TERM: {

  207648.         rc = fts5ExprNodeTest_TERM(pExpr, pNode);

  207649.         break;

  207650.       }

  207651. 

  207652.       case FTS5_AND: {

  207653.         rc = fts5ExprNodeTest_AND(pExpr, pNode);

  207654.         break;

  207655.       }

  207656. 

  207657.       case FTS5_OR: {

  207658.         fts5ExprNodeTest_OR(pExpr, pNode);

  207659.         break;

  207660.       }

  207661. 

  207662.       default: assert( pNode->eType==FTS5_NOT ); {

  207663.         rc = fts5ExprNodeTest_NOT(pExpr, pNode);

  207664.         break;

  207665.       }

  207666.     }

  207667.   }

  207668.   return rc;

  207669. }

  207670. 

  207671.  

  207672. /*

  207673. ** Set node pNode, which is part of expression pExpr, to point to the first

  207674. ** match. If there are no matches, set the Node.bEof flag to indicate EOF.

  207675. **

  207676. ** Return an SQLite error code if an error occurs, or SQLITE_OK otherwise.

  207677. ** It is not an error if there are no matches.

  207678. */

  207679. static int fts5ExprNodeFirst(Fts5Expr *pExpr, Fts5ExprNode *pNode){

  207680.   int rc = SQLITE_OK;

  207681.   pNode->bEof = 0;

  207682.   pNode->bNomatch = 0;

  207683. 

  207684.   if( Fts5NodeIsString(pNode) ){

  207685.     /* Initialize all term iterators in the NEAR object. */

  207686.     rc = fts5ExprNearInitAll(pExpr, pNode);

  207687.   }else if( pNode->xNext==0 ){

  207688.     pNode->bEof = 1;

  207689.   }else{

  207690.     int i;

  207691.     int nEof = 0;

  207692.     for(i=0; i<pNode->nChild && rc==SQLITE_OK; i++){

  207693.       Fts5ExprNode *pChild = pNode->apChild[i];

  207694.       rc = fts5ExprNodeFirst(pExpr, pNode->apChild[i]);

  207695.       assert( pChild->bEof==0 || pChild->bEof==1 );

  207696.       nEof += pChild->bEof;

  207697.     }

  207698.     pNode->iRowid = pNode->apChild[0]->iRowid;

  207699. 

  207700.     switch( pNode->eType ){

  207701.       case FTS5_AND:

  207702.         if( nEof>0 ) fts5ExprSetEof(pNode);

  207703.         break;

  207704. 

  207705.       case FTS5_OR:

  207706.         if( pNode->nChild==nEof ) fts5ExprSetEof(pNode);

  207707.         break;

  207708. 

  207709.       default:

  207710.         assert( pNode->eType==FTS5_NOT );

  207711.         pNode->bEof = pNode->apChild[0]->bEof;

  207712.         break;

  207713.     }

  207714.   }

  207715. 

  207716.   if( rc==SQLITE_OK ){

  207717.     rc = fts5ExprNodeTest(pExpr, pNode);

  207718.   }

  207719.   return rc;

  207720. }

  207721. 

  207722. 

  207723. /*

  207724. ** Begin iterating through the set of documents in index pIdx matched by

  207725. ** the MATCH expression passed as the first argument. If the "bDesc" 

  207726. ** parameter is passed a non-zero value, iteration is in descending rowid 

  207727. ** order. Or, if it is zero, in ascending order.

  207728. **

  207729. ** If iterating in ascending rowid order (bDesc==0), the first document

  207730. ** visited is that with the smallest rowid that is larger than or equal

  207731. ** to parameter iFirst. Or, if iterating in ascending order (bDesc==1),

  207732. ** then the first document visited must have a rowid smaller than or

  207733. ** equal to iFirst.

  207734. **

  207735. ** Return SQLITE_OK if successful, or an SQLite error code otherwise. It

  207736. ** is not considered an error if the query does not match any documents.

  207737. */

  207738. static int sqlite3Fts5ExprFirst(Fts5Expr *p, Fts5Index *pIdx, i64 iFirst, int bDesc){

  207739.   Fts5ExprNode *pRoot = p->pRoot;

  207740.   int rc;                         /* Return code */

  207741. 

  207742.   p->pIndex = pIdx;

  207743.   p->bDesc = bDesc;

  207744.   rc = fts5ExprNodeFirst(p, pRoot);

  207745. 

  207746.   /* If not at EOF but the current rowid occurs earlier than iFirst in

  207747.   ** the iteration order, move to document iFirst or later. */

  207748.   if( rc==SQLITE_OK 

  207749.    && 0==pRoot->bEof 

  207750.    && fts5RowidCmp(p, pRoot->iRowid, iFirst)<0 

  207751.   ){

  207752.     rc = fts5ExprNodeNext(p, pRoot, 1, iFirst);

  207753.   }

  207754. 

  207755.   /* If the iterator is not at a real match, skip forward until it is. */

  207756.   while( pRoot->bNomatch ){

  207757.     assert( pRoot->bEof==0 && rc==SQLITE_OK );

  207758.     rc = fts5ExprNodeNext(p, pRoot, 0, 0);

  207759.   }

  207760.   return rc;

  207761. }

  207762. 

  207763. /*

  207764. ** Move to the next document 

  207765. **

  207766. ** Return SQLITE_OK if successful, or an SQLite error code otherwise. It

  207767. ** is not considered an error if the query does not match any documents.

  207768. */

  207769. static int sqlite3Fts5ExprNext(Fts5Expr *p, i64 iLast){

  207770.   int rc;

  207771.   Fts5ExprNode *pRoot = p->pRoot;

  207772.   assert( pRoot->bEof==0 && pRoot->bNomatch==0 );

  207773.   do {

  207774.     rc = fts5ExprNodeNext(p, pRoot, 0, 0);

  207775.     assert( pRoot->bNomatch==0 || (rc==SQLITE_OK && pRoot->bEof==0) );

  207776.   }while( pRoot->bNomatch );

  207777.   if( fts5RowidCmp(p, pRoot->iRowid, iLast)>0 ){

  207778.     pRoot->bEof = 1;

  207779.   }

  207780.   return rc;

  207781. }

  207782. 

  207783. static int sqlite3Fts5ExprEof(Fts5Expr *p){

  207784.   return p->pRoot->bEof;

  207785. }

  207786. 

  207787. static i64 sqlite3Fts5ExprRowid(Fts5Expr *p){

  207788.   return p->pRoot->iRowid;

  207789. }

  207790. 

  207791. static int fts5ParseStringFromToken(Fts5Token *pToken, char **pz){

  207792.   int rc = SQLITE_OK;

  207793.   *pz = sqlite3Fts5Strndup(&rc, pToken->p, pToken->n);

  207794.   return rc;

  207795. }

  207796. 

  207797. /*

  207798. ** Free the phrase object passed as the only argument.

  207799. */

  207800. static void fts5ExprPhraseFree(Fts5ExprPhrase *pPhrase){

  207801.   if( pPhrase ){

  207802.     int i;

  207803.     for(i=0; i<pPhrase->nTerm; i++){

  207804.       Fts5ExprTerm *pSyn;

  207805.       Fts5ExprTerm *pNext;

  207806.       Fts5ExprTerm *pTerm = &pPhrase->aTerm[i];

  207807.       sqlite3_free(pTerm->zTerm);

  207808.       sqlite3Fts5IterClose(pTerm->pIter);

  207809.       for(pSyn=pTerm->pSynonym; pSyn; pSyn=pNext){

  207810.         pNext = pSyn->pSynonym;

  207811.         sqlite3Fts5IterClose(pSyn->pIter);

  207812.         fts5BufferFree((Fts5Buffer*)&pSyn[1]);

  207813.         sqlite3_free(pSyn);

  207814.       }

  207815.     }

  207816.     if( pPhrase->poslist.nSpace>0 ) fts5BufferFree(&pPhrase->poslist);

  207817.     sqlite3_free(pPhrase);

  207818.   }

  207819. }

  207820. 

  207821. /*

  207822. ** Set the "bFirst" flag on the first token of the phrase passed as the

  207823. ** only argument.

  207824. */

  207825. static void sqlite3Fts5ParseSetCaret(Fts5ExprPhrase *pPhrase){

  207826.   if( pPhrase && pPhrase->nTerm ){

  207827.     pPhrase->aTerm[0].bFirst = 1;

  207828.   }

  207829. }

  207830. 

  207831. /*

  207832. ** If argument pNear is NULL, then a new Fts5ExprNearset object is allocated

  207833. ** and populated with pPhrase. Or, if pNear is not NULL, phrase pPhrase is

  207834. ** appended to it and the results returned.

  207835. **

  207836. ** If an OOM error occurs, both the pNear and pPhrase objects are freed and

  207837. ** NULL returned.

  207838. */

  207839. static Fts5ExprNearset *sqlite3Fts5ParseNearset(

  207840.   Fts5Parse *pParse,              /* Parse context */

  207841.   Fts5ExprNearset *pNear,         /* Existing nearset, or NULL */

  207842.   Fts5ExprPhrase *pPhrase         /* Recently parsed phrase */

  207843. ){

  207844.   const int SZALLOC = 8;

  207845.   Fts5ExprNearset *pRet = 0;

  207846. 

  207847.   if( pParse->rc==SQLITE_OK ){

  207848.     if( pPhrase==0 ){

  207849.       return pNear;

  207850.     }

  207851.     if( pNear==0 ){

  207852.       sqlite3_int64 nByte;

  207853.       nByte = sizeof(Fts5ExprNearset) + SZALLOC * sizeof(Fts5ExprPhrase*);

  207854.       pRet = sqlite3_malloc64(nByte);

  207855.       if( pRet==0 ){

  207856.         pParse->rc = SQLITE_NOMEM;

  207857.       }else{

  207858.         memset(pRet, 0, (size_t)nByte);

  207859.       }

  207860.     }else if( (pNear->nPhrase % SZALLOC)==0 ){

  207861.       int nNew = pNear->nPhrase + SZALLOC;

  207862.       sqlite3_int64 nByte;

  207863. 

  207864.       nByte = sizeof(Fts5ExprNearset) + nNew * sizeof(Fts5ExprPhrase*);

  207865.       pRet = (Fts5ExprNearset*)sqlite3_realloc64(pNear, nByte);

  207866.       if( pRet==0 ){

  207867.         pParse->rc = SQLITE_NOMEM;

  207868.       }

  207869.     }else{

  207870.       pRet = pNear;

  207871.     }

  207872.   }

  207873. 

  207874.   if( pRet==0 ){

  207875.     assert( pParse->rc!=SQLITE_OK );

  207876.     sqlite3Fts5ParseNearsetFree(pNear);

  207877.     sqlite3Fts5ParsePhraseFree(pPhrase);

  207878.   }else{

  207879.     if( pRet->nPhrase>0 ){

  207880.       Fts5ExprPhrase *pLast = pRet->apPhrase[pRet->nPhrase-1];

  207881.       assert( pLast==pParse->apPhrase[pParse->nPhrase-2] );

  207882.       if( pPhrase->nTerm==0 ){

  207883.         fts5ExprPhraseFree(pPhrase);

  207884.         pRet->nPhrase--;

  207885.         pParse->nPhrase--;

  207886.         pPhrase = pLast;

  207887.       }else if( pLast->nTerm==0 ){

  207888.         fts5ExprPhraseFree(pLast);

  207889.         pParse->apPhrase[pParse->nPhrase-2] = pPhrase;

  207890.         pParse->nPhrase--;

  207891.         pRet->nPhrase--;

  207892.       }

  207893.     }

  207894.     pRet->apPhrase[pRet->nPhrase++] = pPhrase;

  207895.   }

  207896.   return pRet;

  207897. }

  207898. 

  207899. typedef struct TokenCtx TokenCtx;

  207900. struct TokenCtx {

  207901.   Fts5ExprPhrase *pPhrase;

  207902.   int rc;

  207903. };

  207904. 

  207905. /*

  207906. ** Callback for tokenizing terms used by ParseTerm().

  207907. */

  207908. static int fts5ParseTokenize(

  207909.   void *pContext,                 /* Pointer to Fts5InsertCtx object */

  207910.   int tflags,                     /* Mask of FTS5_TOKEN_* flags */

  207911.   const char *pToken,             /* Buffer containing token */

  207912.   int nToken,                     /* Size of token in bytes */

  207913.   int iUnused1,                   /* Start offset of token */

  207914.   int iUnused2                    /* End offset of token */

  207915. ){

  207916.   int rc = SQLITE_OK;

  207917.   const int SZALLOC = 8;

  207918.   TokenCtx *pCtx = (TokenCtx*)pContext;

  207919.   Fts5ExprPhrase *pPhrase = pCtx->pPhrase;

  207920. 

  207921.   UNUSED_PARAM2(iUnused1, iUnused2);

  207922. 

  207923.   /* If an error has already occurred, this is a no-op */

  207924.   if( pCtx->rc!=SQLITE_OK ) return pCtx->rc;

  207925.   if( nToken>FTS5_MAX_TOKEN_SIZE ) nToken = FTS5_MAX_TOKEN_SIZE;

  207926. 

  207927.   if( pPhrase && pPhrase->nTerm>0 && (tflags & FTS5_TOKEN_COLOCATED) ){

  207928.     Fts5ExprTerm *pSyn;

  207929.     sqlite3_int64 nByte = sizeof(Fts5ExprTerm) + sizeof(Fts5Buffer) + nToken+1;

  207930.     pSyn = (Fts5ExprTerm*)sqlite3_malloc64(nByte);

  207931.     if( pSyn==0 ){

  207932.       rc = SQLITE_NOMEM;

  207933.     }else{

  207934.       memset(pSyn, 0, (size_t)nByte);

  207935.       pSyn->zTerm = ((char*)pSyn) + sizeof(Fts5ExprTerm) + sizeof(Fts5Buffer);

  207936.       memcpy(pSyn->zTerm, pToken, nToken);

  207937.       pSyn->pSynonym = pPhrase->aTerm[pPhrase->nTerm-1].pSynonym;

  207938.       pPhrase->aTerm[pPhrase->nTerm-1].pSynonym = pSyn;

  207939.     }

  207940.   }else{

  207941.     Fts5ExprTerm *pTerm;

  207942.     if( pPhrase==0 || (pPhrase->nTerm % SZALLOC)==0 ){

  207943.       Fts5ExprPhrase *pNew;

  207944.       int nNew = SZALLOC + (pPhrase ? pPhrase->nTerm : 0);

  207945. 

  207946.       pNew = (Fts5ExprPhrase*)sqlite3_realloc64(pPhrase, 

  207947.           sizeof(Fts5ExprPhrase) + sizeof(Fts5ExprTerm) * nNew

  207948.       );

  207949.       if( pNew==0 ){

  207950.         rc = SQLITE_NOMEM;

  207951.       }else{

  207952.         if( pPhrase==0 ) memset(pNew, 0, sizeof(Fts5ExprPhrase));

  207953.         pCtx->pPhrase = pPhrase = pNew;

  207954.         pNew->nTerm = nNew - SZALLOC;

  207955.       }

  207956.     }

  207957. 

  207958.     if( rc==SQLITE_OK ){

  207959.       pTerm = &pPhrase->aTerm[pPhrase->nTerm++];

  207960.       memset(pTerm, 0, sizeof(Fts5ExprTerm));

  207961.       pTerm->zTerm = sqlite3Fts5Strndup(&rc, pToken, nToken);

  207962.     }

  207963.   }

  207964. 

  207965.   pCtx->rc = rc;

  207966.   return rc;

  207967. }

  207968. 

  207969. 

  207970. /*

  207971. ** Free the phrase object passed as the only argument.

  207972. */

  207973. static void sqlite3Fts5ParsePhraseFree(Fts5ExprPhrase *pPhrase){

  207974.   fts5ExprPhraseFree(pPhrase);

  207975. }

  207976. 

  207977. /*

  207978. ** Free the phrase object passed as the second argument.

  207979. */

  207980. static void sqlite3Fts5ParseNearsetFree(Fts5ExprNearset *pNear){

  207981.   if( pNear ){

  207982.     int i;

  207983.     for(i=0; i<pNear->nPhrase; i++){

  207984.       fts5ExprPhraseFree(pNear->apPhrase[i]);

  207985.     }

  207986.     sqlite3_free(pNear->pColset);

  207987.     sqlite3_free(pNear);

  207988.   }

  207989. }

  207990. 

  207991. static void sqlite3Fts5ParseFinished(Fts5Parse *pParse, Fts5ExprNode *p){

  207992.   assert( pParse->pExpr==0 );

  207993.   pParse->pExpr = p;

  207994. }

  207995. 

  207996. /*

  207997. ** This function is called by the parser to process a string token. The

  207998. ** string may or may not be quoted. In any case it is tokenized and a

  207999. ** phrase object consisting of all tokens returned.

  208000. */

  208001. static Fts5ExprPhrase *sqlite3Fts5ParseTerm(

  208002.   Fts5Parse *pParse,              /* Parse context */

  208003.   Fts5ExprPhrase *pAppend,        /* Phrase to append to */

  208004.   Fts5Token *pToken,              /* String to tokenize */

  208005.   int bPrefix                     /* True if there is a trailing "*" */

  208006. ){

  208007.   Fts5Config *pConfig = pParse->pConfig;

  208008.   TokenCtx sCtx;                  /* Context object passed to callback */

  208009.   int rc;                         /* Tokenize return code */

  208010.   char *z = 0;

  208011. 

  208012.   memset(&sCtx, 0, sizeof(TokenCtx));

  208013.   sCtx.pPhrase = pAppend;

  208014. 

  208015.   rc = fts5ParseStringFromToken(pToken, &z);

  208016.   if( rc==SQLITE_OK ){

  208017.     int flags = FTS5_TOKENIZE_QUERY | (bPrefix ? FTS5_TOKENIZE_PREFIX : 0);

  208018.     int n;

  208019.     sqlite3Fts5Dequote(z);

  208020.     n = (int)strlen(z);

  208021.     rc = sqlite3Fts5Tokenize(pConfig, flags, z, n, &sCtx, fts5ParseTokenize);

  208022.   }

  208023.   sqlite3_free(z);

  208024.   if( rc || (rc = sCtx.rc) ){

  208025.     pParse->rc = rc;

  208026.     fts5ExprPhraseFree(sCtx.pPhrase);

  208027.     sCtx.pPhrase = 0;

  208028.   }else{

  208029. 

  208030.     if( pAppend==0 ){

  208031.       if( (pParse->nPhrase % 8)==0 ){

  208032.         sqlite3_int64 nByte = sizeof(Fts5ExprPhrase*) * (pParse->nPhrase + 8);

  208033.         Fts5ExprPhrase **apNew;

  208034.         apNew = (Fts5ExprPhrase**)sqlite3_realloc64(pParse->apPhrase, nByte);

  208035.         if( apNew==0 ){

  208036.           pParse->rc = SQLITE_NOMEM;

  208037.           fts5ExprPhraseFree(sCtx.pPhrase);

  208038.           return 0;

  208039.         }

  208040.         pParse->apPhrase = apNew;

  208041.       }

  208042.       pParse->nPhrase++;

  208043.     }

  208044. 

  208045.     if( sCtx.pPhrase==0 ){

  208046.       /* This happens when parsing a token or quoted phrase that contains

  208047.       ** no token characters at all. (e.g ... MATCH '""'). */

  208048.       sCtx.pPhrase = sqlite3Fts5MallocZero(&pParse->rc, sizeof(Fts5ExprPhrase));

  208049.     }else if( sCtx.pPhrase->nTerm ){

  208050.       sCtx.pPhrase->aTerm[sCtx.pPhrase->nTerm-1].bPrefix = (u8)bPrefix;

  208051.     }

  208052.     pParse->apPhrase[pParse->nPhrase-1] = sCtx.pPhrase;

  208053.   }

  208054. 

  208055.   return sCtx.pPhrase;

  208056. }

  208057. 

  208058. /*

  208059. ** Create a new FTS5 expression by cloning phrase iPhrase of the

  208060. ** expression passed as the second argument.

  208061. */

  208062. static int sqlite3Fts5ExprClonePhrase(

  208063.   Fts5Expr *pExpr, 

  208064.   int iPhrase, 

  208065.   Fts5Expr **ppNew

  208066. ){

  208067.   int rc = SQLITE_OK;             /* Return code */

  208068.   Fts5ExprPhrase *pOrig;          /* The phrase extracted from pExpr */

  208069.   Fts5Expr *pNew = 0;             /* Expression to return via *ppNew */

  208070.   TokenCtx sCtx = {0,0};          /* Context object for fts5ParseTokenize */

  208071. 

  208072.   pOrig = pExpr->apExprPhrase[iPhrase];

  208073.   pNew = (Fts5Expr*)sqlite3Fts5MallocZero(&rc, sizeof(Fts5Expr));

  208074.   if( rc==SQLITE_OK ){

  208075.     pNew->apExprPhrase = (Fts5ExprPhrase**)sqlite3Fts5MallocZero(&rc, 

  208076.         sizeof(Fts5ExprPhrase*));

  208077.   }

  208078.   if( rc==SQLITE_OK ){

  208079.     pNew->pRoot = (Fts5ExprNode*)sqlite3Fts5MallocZero(&rc, 

  208080.         sizeof(Fts5ExprNode));

  208081.   }

  208082.   if( rc==SQLITE_OK ){

  208083.     pNew->pRoot->pNear = (Fts5ExprNearset*)sqlite3Fts5MallocZero(&rc, 

  208084.         sizeof(Fts5ExprNearset) + sizeof(Fts5ExprPhrase*));

  208085.   }

  208086.   if( rc==SQLITE_OK ){

  208087.     Fts5Colset *pColsetOrig = pOrig->pNode->pNear->pColset;

  208088.     if( pColsetOrig ){

  208089.       sqlite3_int64 nByte;

  208090.       Fts5Colset *pColset;

  208091.       nByte = sizeof(Fts5Colset) + (pColsetOrig->nCol-1) * sizeof(int);

  208092.       pColset = (Fts5Colset*)sqlite3Fts5MallocZero(&rc, nByte);

  208093.       if( pColset ){ 

  208094.         memcpy(pColset, pColsetOrig, (size_t)nByte);

  208095.       }

  208096.       pNew->pRoot->pNear->pColset = pColset;

  208097.     }

  208098.   }

  208099. 

  208100.   if( pOrig->nTerm ){

  208101.     int i;                          /* Used to iterate through phrase terms */

  208102.     for(i=0; rc==SQLITE_OK && i<pOrig->nTerm; i++){

  208103.       int tflags = 0;

  208104.       Fts5ExprTerm *p;

  208105.       for(p=&pOrig->aTerm[i]; p && rc==SQLITE_OK; p=p->pSynonym){

  208106.         const char *zTerm = p->zTerm;

  208107.         rc = fts5ParseTokenize((void*)&sCtx, tflags, zTerm, (int)strlen(zTerm),

  208108.             0, 0);

  208109.         tflags = FTS5_TOKEN_COLOCATED;

  208110.       }

  208111.       if( rc==SQLITE_OK ){

  208112.         sCtx.pPhrase->aTerm[i].bPrefix = pOrig->aTerm[i].bPrefix;

  208113.         sCtx.pPhrase->aTerm[i].bFirst = pOrig->aTerm[i].bFirst;

  208114.       }

  208115.     }

  208116.   }else{

  208117.     /* This happens when parsing a token or quoted phrase that contains

  208118.     ** no token characters at all. (e.g ... MATCH '""'). */

  208119.     sCtx.pPhrase = sqlite3Fts5MallocZero(&rc, sizeof(Fts5ExprPhrase));

  208120.   }

  208121. 

  208122.   if( rc==SQLITE_OK ){

  208123.     /* All the allocations succeeded. Put the expression object together. */

  208124.     pNew->pIndex = pExpr->pIndex;

  208125.     pNew->pConfig = pExpr->pConfig;

  208126.     pNew->nPhrase = 1;

  208127.     pNew->apExprPhrase[0] = sCtx.pPhrase;

  208128.     pNew->pRoot->pNear->apPhrase[0] = sCtx.pPhrase;

  208129.     pNew->pRoot->pNear->nPhrase = 1;

  208130.     sCtx.pPhrase->pNode = pNew->pRoot;

  208131. 

  208132.     if( pOrig->nTerm==1 

  208133.      && pOrig->aTerm[0].pSynonym==0 

  208134.      && pOrig->aTerm[0].bFirst==0 

  208135.     ){

  208136.       pNew->pRoot->eType = FTS5_TERM;

  208137.       pNew->pRoot->xNext = fts5ExprNodeNext_TERM;

  208138.     }else{

  208139.       pNew->pRoot->eType = FTS5_STRING;

  208140.       pNew->pRoot->xNext = fts5ExprNodeNext_STRING;

  208141.     }

  208142.   }else{

  208143.     sqlite3Fts5ExprFree(pNew);

  208144.     fts5ExprPhraseFree(sCtx.pPhrase);

  208145.     pNew = 0;

  208146.   }

  208147. 

  208148.   *ppNew = pNew;

  208149.   return rc;

  208150. }

  208151. 

  208152. 

  208153. /*

  208154. ** Token pTok has appeared in a MATCH expression where the NEAR operator

  208155. ** is expected. If token pTok does not contain "NEAR", store an error

  208156. ** in the pParse object.

  208157. */

  208158. static void sqlite3Fts5ParseNear(Fts5Parse *pParse, Fts5Token *pTok){

  208159.   if( pTok->n!=4 || memcmp("NEAR", pTok->p, 4) ){

  208160.     sqlite3Fts5ParseError(

  208161.         pParse, "fts5: syntax error near \"%.*s\"", pTok->n, pTok->p

  208162.     );

  208163.   }

  208164. }

  208165. 

  208166. static void sqlite3Fts5ParseSetDistance(

  208167.   Fts5Parse *pParse, 

  208168.   Fts5ExprNearset *pNear,

  208169.   Fts5Token *p

  208170. ){

  208171.   if( pNear ){

  208172.     int nNear = 0;

  208173.     int i;

  208174.     if( p->n ){

  208175.       for(i=0; i<p->n; i++){

  208176.         char c = (char)p->p[i];

  208177.         if( c<'0' || c>'9' ){

  208178.           sqlite3Fts5ParseError(

  208179.               pParse, "expected integer, got \"%.*s\"", p->n, p->p

  208180.               );

  208181.           return;

  208182.         }

  208183.         nNear = nNear * 10 + (p->p[i] - '0');

  208184.       }

  208185.     }else{

  208186.       nNear = FTS5_DEFAULT_NEARDIST;

  208187.     }

  208188.     pNear->nNear = nNear;

  208189.   }

  208190. }

  208191. 

  208192. /*

  208193. ** The second argument passed to this function may be NULL, or it may be

  208194. ** an existing Fts5Colset object. This function returns a pointer to

  208195. ** a new colset object containing the contents of (p) with new value column

  208196. ** number iCol appended. 

  208197. **

  208198. ** If an OOM error occurs, store an error code in pParse and return NULL.

  208199. ** The old colset object (if any) is not freed in this case.

  208200. */

  208201. static Fts5Colset *fts5ParseColset(

  208202.   Fts5Parse *pParse,              /* Store SQLITE_NOMEM here if required */

  208203.   Fts5Colset *p,                  /* Existing colset object */

  208204.   int iCol                        /* New column to add to colset object */

  208205. ){

  208206.   int nCol = p ? p->nCol : 0;     /* Num. columns already in colset object */

  208207.   Fts5Colset *pNew;               /* New colset object to return */

  208208. 

  208209.   assert( pParse->rc==SQLITE_OK );

  208210.   assert( iCol>=0 && iCol<pParse->pConfig->nCol );

  208211. 

  208212.   pNew = sqlite3_realloc64(p, sizeof(Fts5Colset) + sizeof(int)*nCol);

  208213.   if( pNew==0 ){

  208214.     pParse->rc = SQLITE_NOMEM;

  208215.   }else{

  208216.     int *aiCol = pNew->aiCol;

  208217.     int i, j;

  208218.     for(i=0; i<nCol; i++){

  208219.       if( aiCol[i]==iCol ) return pNew;

  208220.       if( aiCol[i]>iCol ) break;

  208221.     }

  208222.     for(j=nCol; j>i; j--){

  208223.       aiCol[j] = aiCol[j-1];

  208224.     }

  208225.     aiCol[i] = iCol;

  208226.     pNew->nCol = nCol+1;

  208227. 

  208228. #ifndef NDEBUG

  208229.     /* Check that the array is in order and contains no duplicate entries. */

  208230.     for(i=1; i<pNew->nCol; i++) assert( pNew->aiCol[i]>pNew->aiCol[i-1] );

  208231. #endif

  208232.   }

  208233. 

  208234.   return pNew;

  208235. }

  208236. 

  208237. /*

  208238. ** Allocate and return an Fts5Colset object specifying the inverse of

  208239. ** the colset passed as the second argument. Free the colset passed

  208240. ** as the second argument before returning.

  208241. */

  208242. static Fts5Colset *sqlite3Fts5ParseColsetInvert(Fts5Parse *pParse, Fts5Colset *p){

  208243.   Fts5Colset *pRet;

  208244.   int nCol = pParse->pConfig->nCol;

  208245. 

  208246.   pRet = (Fts5Colset*)sqlite3Fts5MallocZero(&pParse->rc, 

  208247.       sizeof(Fts5Colset) + sizeof(int)*nCol

  208248.   );

  208249.   if( pRet ){

  208250.     int i;

  208251.     int iOld = 0;

  208252.     for(i=0; i<nCol; i++){

  208253.       if( iOld>=p->nCol || p->aiCol[iOld]!=i ){

  208254.         pRet->aiCol[pRet->nCol++] = i;

  208255.       }else{

  208256.         iOld++;

  208257.       }

  208258.     }

  208259.   }

  208260. 

  208261.   sqlite3_free(p);

  208262.   return pRet;

  208263. }

  208264. 

  208265. static Fts5Colset *sqlite3Fts5ParseColset(

  208266.   Fts5Parse *pParse,              /* Store SQLITE_NOMEM here if required */

  208267.   Fts5Colset *pColset,            /* Existing colset object */

  208268.   Fts5Token *p

  208269. ){

  208270.   Fts5Colset *pRet = 0;

  208271.   int iCol;

  208272.   char *z;                        /* Dequoted copy of token p */

  208273. 

  208274.   z = sqlite3Fts5Strndup(&pParse->rc, p->p, p->n);

  208275.   if( pParse->rc==SQLITE_OK ){

  208276.     Fts5Config *pConfig = pParse->pConfig;

  208277.     sqlite3Fts5Dequote(z);

  208278.     for(iCol=0; iCol<pConfig->nCol; iCol++){

  208279.       if( 0==sqlite3_stricmp(pConfig->azCol[iCol], z) ) break;

  208280.     }

  208281.     if( iCol==pConfig->nCol ){

  208282.       sqlite3Fts5ParseError(pParse, "no such column: %s", z);

  208283.     }else{

  208284.       pRet = fts5ParseColset(pParse, pColset, iCol);

  208285.     }

  208286.     sqlite3_free(z);

  208287.   }

  208288. 

  208289.   if( pRet==0 ){

  208290.     assert( pParse->rc!=SQLITE_OK );

  208291.     sqlite3_free(pColset);

  208292.   }

  208293. 

  208294.   return pRet;

  208295. }

  208296. 

  208297. /*

  208298. ** If argument pOrig is NULL, or if (*pRc) is set to anything other than

  208299. ** SQLITE_OK when this function is called, NULL is returned. 

  208300. **

  208301. ** Otherwise, a copy of (*pOrig) is made into memory obtained from

  208302. ** sqlite3Fts5MallocZero() and a pointer to it returned. If the allocation

  208303. ** fails, (*pRc) is set to SQLITE_NOMEM and NULL is returned.

  208304. */

  208305. static Fts5Colset *fts5CloneColset(int *pRc, Fts5Colset *pOrig){

  208306.   Fts5Colset *pRet;

  208307.   if( pOrig ){

  208308.     sqlite3_int64 nByte = sizeof(Fts5Colset) + (pOrig->nCol-1) * sizeof(int);

  208309.     pRet = (Fts5Colset*)sqlite3Fts5MallocZero(pRc, nByte);

  208310.     if( pRet ){ 

  208311.       memcpy(pRet, pOrig, (size_t)nByte);

  208312.     }

  208313.   }else{

  208314.     pRet = 0;

  208315.   }

  208316.   return pRet;

  208317. }

  208318. 

  208319. /*

  208320. ** Remove from colset pColset any columns that are not also in colset pMerge.

  208321. */

  208322. static void fts5MergeColset(Fts5Colset *pColset, Fts5Colset *pMerge){

  208323.   int iIn = 0;          /* Next input in pColset */

  208324.   int iMerge = 0;       /* Next input in pMerge */

  208325.   int iOut = 0;         /* Next output slot in pColset */

  208326. 

  208327.   while( iIn<pColset->nCol && iMerge<pMerge->nCol ){

  208328.     int iDiff = pColset->aiCol[iIn] - pMerge->aiCol[iMerge];

  208329.     if( iDiff==0 ){

  208330.       pColset->aiCol[iOut++] = pMerge->aiCol[iMerge];

  208331.       iMerge++;

  208332.       iIn++;

  208333.     }else if( iDiff>0 ){

  208334.       iMerge++;

  208335.     }else{

  208336.       iIn++;

  208337.     }

  208338.   }

  208339.   pColset->nCol = iOut;

  208340. }

  208341. 

  208342. /*

  208343. ** Recursively apply colset pColset to expression node pNode and all of

  208344. ** its decendents. If (*ppFree) is not NULL, it contains a spare copy

  208345. ** of pColset. This function may use the spare copy and set (*ppFree) to

  208346. ** zero, or it may create copies of pColset using fts5CloneColset().

  208347. */

  208348. static void fts5ParseSetColset(

  208349.   Fts5Parse *pParse, 

  208350.   Fts5ExprNode *pNode, 

  208351.   Fts5Colset *pColset,

  208352.   Fts5Colset **ppFree

  208353. ){

  208354.   if( pParse->rc==SQLITE_OK ){

  208355.     assert( pNode->eType==FTS5_TERM || pNode->eType==FTS5_STRING 

  208356.          || pNode->eType==FTS5_AND  || pNode->eType==FTS5_OR

  208357.          || pNode->eType==FTS5_NOT  || pNode->eType==FTS5_EOF

  208358.     );

  208359.     if( pNode->eType==FTS5_STRING || pNode->eType==FTS5_TERM ){

  208360.       Fts5ExprNearset *pNear = pNode->pNear;

  208361.       if( pNear->pColset ){

  208362.         fts5MergeColset(pNear->pColset, pColset);

  208363.         if( pNear->pColset->nCol==0 ){

  208364.           pNode->eType = FTS5_EOF;

  208365.           pNode->xNext = 0;

  208366.         }

  208367.       }else if( *ppFree ){

  208368.         pNear->pColset = pColset;

  208369.         *ppFree = 0;

  208370.       }else{

  208371.         pNear->pColset = fts5CloneColset(&pParse->rc, pColset);

  208372.       }

  208373.     }else{

  208374.       int i;

  208375.       assert( pNode->eType!=FTS5_EOF || pNode->nChild==0 );

  208376.       for(i=0; i<pNode->nChild; i++){

  208377.         fts5ParseSetColset(pParse, pNode->apChild[i], pColset, ppFree);

  208378.       }

  208379.     }

  208380.   }

  208381. }

  208382. 

  208383. /*

  208384. ** Apply colset pColset to expression node pExpr and all of its descendents.

  208385. */

  208386. static void sqlite3Fts5ParseSetColset(

  208387.   Fts5Parse *pParse, 

  208388.   Fts5ExprNode *pExpr, 

  208389.   Fts5Colset *pColset 

  208390. ){

  208391.   Fts5Colset *pFree = pColset;

  208392.   if( pParse->pConfig->eDetail==FTS5_DETAIL_NONE ){

  208393.     pParse->rc = SQLITE_ERROR;

  208394.     pParse->zErr = sqlite3_mprintf(

  208395.       "fts5: column queries are not supported (detail=none)"

  208396.     );

  208397.   }else{

  208398.     fts5ParseSetColset(pParse, pExpr, pColset, &pFree);

  208399.   }

  208400.   sqlite3_free(pFree);

  208401. }

  208402. 

  208403. static void fts5ExprAssignXNext(Fts5ExprNode *pNode){

  208404.   switch( pNode->eType ){

  208405.     case FTS5_STRING: {

  208406.       Fts5ExprNearset *pNear = pNode->pNear;

  208407.       if( pNear->nPhrase==1 && pNear->apPhrase[0]->nTerm==1 

  208408.        && pNear->apPhrase[0]->aTerm[0].pSynonym==0

  208409.        && pNear->apPhrase[0]->aTerm[0].bFirst==0

  208410.       ){

  208411.         pNode->eType = FTS5_TERM;

  208412.         pNode->xNext = fts5ExprNodeNext_TERM;

  208413.       }else{

  208414.         pNode->xNext = fts5ExprNodeNext_STRING;

  208415.       }

  208416.       break;

  208417.     };

  208418. 

  208419.     case FTS5_OR: {

  208420.       pNode->xNext = fts5ExprNodeNext_OR;

  208421.       break;

  208422.     };

  208423. 

  208424.     case FTS5_AND: {

  208425.       pNode->xNext = fts5ExprNodeNext_AND;

  208426.       break;

  208427.     };

  208428. 

  208429.     default: assert( pNode->eType==FTS5_NOT ); {

  208430.       pNode->xNext = fts5ExprNodeNext_NOT;

  208431.       break;

  208432.     };

  208433.   }

  208434. }

  208435. 

  208436. static void fts5ExprAddChildren(Fts5ExprNode *p, Fts5ExprNode *pSub){

  208437.   if( p->eType!=FTS5_NOT && pSub->eType==p->eType ){

  208438.     int nByte = sizeof(Fts5ExprNode*) * pSub->nChild;

  208439.     memcpy(&p->apChild[p->nChild], pSub->apChild, nByte);

  208440.     p->nChild += pSub->nChild;

  208441.     sqlite3_free(pSub);

  208442.   }else{

  208443.     p->apChild[p->nChild++] = pSub;

  208444.   }

  208445. }

  208446. 

  208447. /*

  208448. ** Allocate and return a new expression object. If anything goes wrong (i.e.

  208449. ** OOM error), leave an error code in pParse and return NULL.

  208450. */

  208451. static Fts5ExprNode *sqlite3Fts5ParseNode(

  208452.   Fts5Parse *pParse,              /* Parse context */

  208453.   int eType,                      /* FTS5_STRING, AND, OR or NOT */

  208454.   Fts5ExprNode *pLeft,            /* Left hand child expression */

  208455.   Fts5ExprNode *pRight,           /* Right hand child expression */

  208456.   Fts5ExprNearset *pNear          /* For STRING expressions, the near cluster */

  208457. ){

  208458.   Fts5ExprNode *pRet = 0;

  208459. 

  208460.   if( pParse->rc==SQLITE_OK ){

  208461.     int nChild = 0;               /* Number of children of returned node */

  208462.     sqlite3_int64 nByte;          /* Bytes of space to allocate for this node */

  208463.  

  208464.     assert( (eType!=FTS5_STRING && !pNear)

  208465.          || (eType==FTS5_STRING && !pLeft && !pRight)

  208466.     );

  208467.     if( eType==FTS5_STRING && pNear==0 ) return 0;

  208468.     if( eType!=FTS5_STRING && pLeft==0 ) return pRight;

  208469.     if( eType!=FTS5_STRING && pRight==0 ) return pLeft;

  208470. 

  208471.     if( eType==FTS5_NOT ){

  208472.       nChild = 2;

  208473.     }else if( eType==FTS5_AND || eType==FTS5_OR ){

  208474.       nChild = 2;

  208475.       if( pLeft->eType==eType ) nChild += pLeft->nChild-1;

  208476.       if( pRight->eType==eType ) nChild += pRight->nChild-1;

  208477.     }

  208478. 

  208479.     nByte = sizeof(Fts5ExprNode) + sizeof(Fts5ExprNode*)*(nChild-1);

  208480.     pRet = (Fts5ExprNode*)sqlite3Fts5MallocZero(&pParse->rc, nByte);

  208481. 

  208482.     if( pRet ){

  208483.       pRet->eType = eType;

  208484.       pRet->pNear = pNear;

  208485.       fts5ExprAssignXNext(pRet);

  208486.       if( eType==FTS5_STRING ){

  208487.         int iPhrase;

  208488.         for(iPhrase=0; iPhrase<pNear->nPhrase; iPhrase++){

  208489.           pNear->apPhrase[iPhrase]->pNode = pRet;

  208490.           if( pNear->apPhrase[iPhrase]->nTerm==0 ){

  208491.             pRet->xNext = 0;

  208492.             pRet->eType = FTS5_EOF;

  208493.           }

  208494.         }

  208495. 

  208496.         if( pParse->pConfig->eDetail!=FTS5_DETAIL_FULL ){

  208497.           Fts5ExprPhrase *pPhrase = pNear->apPhrase[0];

  208498.           if( pNear->nPhrase!=1 

  208499.            || pPhrase->nTerm>1

  208500.            || (pPhrase->nTerm>0 && pPhrase->aTerm[0].bFirst)

  208501.           ){

  208502.             assert( pParse->rc==SQLITE_OK );

  208503.             pParse->rc = SQLITE_ERROR;

  208504.             assert( pParse->zErr==0 );

  208505.             pParse->zErr = sqlite3_mprintf(

  208506.                 "fts5: %s queries are not supported (detail!=full)", 

  208507.                 pNear->nPhrase==1 ? "phrase": "NEAR"

  208508.                 );

  208509.             sqlite3_free(pRet);

  208510.             pRet = 0;

  208511.           }

  208512.         }

  208513.       }else{

  208514.         fts5ExprAddChildren(pRet, pLeft);

  208515.         fts5ExprAddChildren(pRet, pRight);

  208516.       }

  208517.     }

  208518.   }

  208519. 

  208520.   if( pRet==0 ){

  208521.     assert( pParse->rc!=SQLITE_OK );

  208522.     sqlite3Fts5ParseNodeFree(pLeft);

  208523.     sqlite3Fts5ParseNodeFree(pRight);

  208524.     sqlite3Fts5ParseNearsetFree(pNear);

  208525.   }

  208526.   return pRet;

  208527. }

  208528. 

  208529. static Fts5ExprNode *sqlite3Fts5ParseImplicitAnd(

  208530.   Fts5Parse *pParse,              /* Parse context */

  208531.   Fts5ExprNode *pLeft,            /* Left hand child expression */

  208532.   Fts5ExprNode *pRight            /* Right hand child expression */

  208533. ){

  208534.   Fts5ExprNode *pRet = 0;

  208535.   Fts5ExprNode *pPrev;

  208536. 

  208537.   if( pParse->rc ){

  208538.     sqlite3Fts5ParseNodeFree(pLeft);

  208539.     sqlite3Fts5ParseNodeFree(pRight);

  208540.   }else{

  208541. 

  208542.     assert( pLeft->eType==FTS5_STRING 

  208543.         || pLeft->eType==FTS5_TERM

  208544.         || pLeft->eType==FTS5_EOF

  208545.         || pLeft->eType==FTS5_AND

  208546.     );

  208547.     assert( pRight->eType==FTS5_STRING 

  208548.         || pRight->eType==FTS5_TERM 

  208549.         || pRight->eType==FTS5_EOF 

  208550.     );

  208551. 

  208552.     if( pLeft->eType==FTS5_AND ){

  208553.       pPrev = pLeft->apChild[pLeft->nChild-1];

  208554.     }else{

  208555.       pPrev = pLeft;

  208556.     }

  208557.     assert( pPrev->eType==FTS5_STRING 

  208558.         || pPrev->eType==FTS5_TERM 

  208559.         || pPrev->eType==FTS5_EOF 

  208560.         );

  208561. 

  208562.     if( pRight->eType==FTS5_EOF ){

  208563.       assert( pParse->apPhrase[pParse->nPhrase-1]==pRight->pNear->apPhrase[0] );

  208564.       sqlite3Fts5ParseNodeFree(pRight);

  208565.       pRet = pLeft;

  208566.       pParse->nPhrase--;

  208567.     }

  208568.     else if( pPrev->eType==FTS5_EOF ){

  208569.       Fts5ExprPhrase **ap;

  208570. 

  208571.       if( pPrev==pLeft ){

  208572.         pRet = pRight;

  208573.       }else{

  208574.         pLeft->apChild[pLeft->nChild-1] = pRight;

  208575.         pRet = pLeft;

  208576.       }

  208577. 

  208578.       ap = &pParse->apPhrase[pParse->nPhrase-1-pRight->pNear->nPhrase];

  208579.       assert( ap[0]==pPrev->pNear->apPhrase[0] );

  208580.       memmove(ap, &ap[1], sizeof(Fts5ExprPhrase*)*pRight->pNear->nPhrase);

  208581.       pParse->nPhrase--;

  208582. 

  208583.       sqlite3Fts5ParseNodeFree(pPrev);

  208584.     }

  208585.     else{

  208586.       pRet = sqlite3Fts5ParseNode(pParse, FTS5_AND, pLeft, pRight, 0);

  208587.     }

  208588.   }

  208589. 

  208590.   return pRet;

  208591. }

  208592. 

  208593. static char *fts5ExprTermPrint(Fts5ExprTerm *pTerm){

  208594.   sqlite3_int64 nByte = 0;

  208595.   Fts5ExprTerm *p;

  208596.   char *zQuoted;

  208597. 

  208598.   /* Determine the maximum amount of space required. */

  208599.   for(p=pTerm; p; p=p->pSynonym){

  208600.     nByte += (int)strlen(pTerm->zTerm) * 2 + 3 + 2;

  208601.   }

  208602.   zQuoted = sqlite3_malloc64(nByte);

  208603. 

  208604.   if( zQuoted ){

  208605.     int i = 0;

  208606.     for(p=pTerm; p; p=p->pSynonym){

  208607.       char *zIn = p->zTerm;

  208608.       zQuoted[i++] = '"';

  208609.       while( *zIn ){

  208610.         if( *zIn=='"' ) zQuoted[i++] = '"';

  208611.         zQuoted[i++] = *zIn++;

  208612.       }

  208613.       zQuoted[i++] = '"';

  208614.       if( p->pSynonym ) zQuoted[i++] = '|';

  208615.     }

  208616.     if( pTerm->bPrefix ){

  208617.       zQuoted[i++] = ' ';

  208618.       zQuoted[i++] = '*';

  208619.     }

  208620.     zQuoted[i++] = '\0';

  208621.   }

  208622.   return zQuoted;

  208623. }

  208624. 

  208625. static char *fts5PrintfAppend(char *zApp, const char *zFmt, ...){

  208626.   char *zNew;

  208627.   va_list ap;

  208628.   va_start(ap, zFmt);

  208629.   zNew = sqlite3_vmprintf(zFmt, ap);

  208630.   va_end(ap);

  208631.   if( zApp && zNew ){

  208632.     char *zNew2 = sqlite3_mprintf("%s%s", zApp, zNew);

  208633.     sqlite3_free(zNew);

  208634.     zNew = zNew2;

  208635.   }

  208636.   sqlite3_free(zApp);

  208637.   return zNew;

  208638. }

  208639. 

  208640. /*

  208641. ** Compose a tcl-readable representation of expression pExpr. Return a 

  208642. ** pointer to a buffer containing that representation. It is the 

  208643. ** responsibility of the caller to at some point free the buffer using 

  208644. ** sqlite3_free().

  208645. */

  208646. static char *fts5ExprPrintTcl(

  208647.   Fts5Config *pConfig, 

  208648.   const char *zNearsetCmd,

  208649.   Fts5ExprNode *pExpr

  208650. ){

  208651.   char *zRet = 0;

  208652.   if( pExpr->eType==FTS5_STRING || pExpr->eType==FTS5_TERM ){

  208653.     Fts5ExprNearset *pNear = pExpr->pNear;

  208654.     int i; 

  208655.     int iTerm;

  208656. 

  208657.     zRet = fts5PrintfAppend(zRet, "%s ", zNearsetCmd);

  208658.     if( zRet==0 ) return 0;

  208659.     if( pNear->pColset ){

  208660.       int *aiCol = pNear->pColset->aiCol;

  208661.       int nCol = pNear->pColset->nCol;

  208662.       if( nCol==1 ){

  208663.         zRet = fts5PrintfAppend(zRet, "-col %d ", aiCol[0]);

  208664.       }else{

  208665.         zRet = fts5PrintfAppend(zRet, "-col {%d", aiCol[0]);

  208666.         for(i=1; i<pNear->pColset->nCol; i++){

  208667.           zRet = fts5PrintfAppend(zRet, " %d", aiCol[i]);

  208668.         }

  208669.         zRet = fts5PrintfAppend(zRet, "} ");

  208670.       }

  208671.       if( zRet==0 ) return 0;

  208672.     }

  208673. 

  208674.     if( pNear->nPhrase>1 ){

  208675.       zRet = fts5PrintfAppend(zRet, "-near %d ", pNear->nNear);

  208676.       if( zRet==0 ) return 0;

  208677.     }

  208678. 

  208679.     zRet = fts5PrintfAppend(zRet, "--");

  208680.     if( zRet==0 ) return 0;

  208681. 

  208682.     for(i=0; i<pNear->nPhrase; i++){

  208683.       Fts5ExprPhrase *pPhrase = pNear->apPhrase[i];

  208684. 

  208685.       zRet = fts5PrintfAppend(zRet, " {");

  208686.       for(iTerm=0; zRet && iTerm<pPhrase->nTerm; iTerm++){

  208687.         char *zTerm = pPhrase->aTerm[iTerm].zTerm;

  208688.         zRet = fts5PrintfAppend(zRet, "%s%s", iTerm==0?"":" ", zTerm);

  208689.         if( pPhrase->aTerm[iTerm].bPrefix ){

  208690.           zRet = fts5PrintfAppend(zRet, "*");

  208691.         }

  208692.       }

  208693. 

  208694.       if( zRet ) zRet = fts5PrintfAppend(zRet, "}");

  208695.       if( zRet==0 ) return 0;

  208696.     }

  208697. 

  208698.   }else{

  208699.     char const *zOp = 0;

  208700.     int i;

  208701.     switch( pExpr->eType ){

  208702.       case FTS5_AND: zOp = "AND"; break;

  208703.       case FTS5_NOT: zOp = "NOT"; break;

  208704.       default: 

  208705.         assert( pExpr->eType==FTS5_OR );

  208706.         zOp = "OR"; 

  208707.         break;

  208708.     }

  208709. 

  208710.     zRet = sqlite3_mprintf("%s", zOp);

  208711.     for(i=0; zRet && i<pExpr->nChild; i++){

  208712.       char *z = fts5ExprPrintTcl(pConfig, zNearsetCmd, pExpr->apChild[i]);

  208713.       if( !z ){

  208714.         sqlite3_free(zRet);

  208715.         zRet = 0;

  208716.       }else{

  208717.         zRet = fts5PrintfAppend(zRet, " [%z]", z);

  208718.       }

  208719.     }

  208720.   }

  208721. 

  208722.   return zRet;

  208723. }

  208724. 

  208725. static char *fts5ExprPrint(Fts5Config *pConfig, Fts5ExprNode *pExpr){

  208726.   char *zRet = 0;

  208727.   if( pExpr->eType==0 ){

  208728.     return sqlite3_mprintf("\"\"");

  208729.   }else

  208730.   if( pExpr->eType==FTS5_STRING || pExpr->eType==FTS5_TERM ){

  208731.     Fts5ExprNearset *pNear = pExpr->pNear;

  208732.     int i; 

  208733.     int iTerm;

  208734. 

  208735.     if( pNear->pColset ){

  208736.       int iCol = pNear->pColset->aiCol[0];

  208737.       zRet = fts5PrintfAppend(zRet, "%s : ", pConfig->azCol[iCol]);

  208738.       if( zRet==0 ) return 0;

  208739.     }

  208740. 

  208741.     if( pNear->nPhrase>1 ){

  208742.       zRet = fts5PrintfAppend(zRet, "NEAR(");

  208743.       if( zRet==0 ) return 0;

  208744.     }

  208745. 

  208746.     for(i=0; i<pNear->nPhrase; i++){

  208747.       Fts5ExprPhrase *pPhrase = pNear->apPhrase[i];

  208748.       if( i!=0 ){

  208749.         zRet = fts5PrintfAppend(zRet, " ");

  208750.         if( zRet==0 ) return 0;

  208751.       }

  208752.       for(iTerm=0; iTerm<pPhrase->nTerm; iTerm++){

  208753.         char *zTerm = fts5ExprTermPrint(&pPhrase->aTerm[iTerm]);

  208754.         if( zTerm ){

  208755.           zRet = fts5PrintfAppend(zRet, "%s%s", iTerm==0?"":" + ", zTerm);

  208756.           sqlite3_free(zTerm);

  208757.         }

  208758.         if( zTerm==0 || zRet==0 ){

  208759.           sqlite3_free(zRet);

  208760.           return 0;

  208761.         }

  208762.       }

  208763.     }

  208764. 

  208765.     if( pNear->nPhrase>1 ){

  208766.       zRet = fts5PrintfAppend(zRet, ", %d)", pNear->nNear);

  208767.       if( zRet==0 ) return 0;

  208768.     }

  208769. 

  208770.   }else{

  208771.     char const *zOp = 0;

  208772.     int i;

  208773. 

  208774.     switch( pExpr->eType ){

  208775.       case FTS5_AND: zOp = " AND "; break;

  208776.       case FTS5_NOT: zOp = " NOT "; break;

  208777.       default:  

  208778.         assert( pExpr->eType==FTS5_OR );

  208779.         zOp = " OR "; 

  208780.         break;

  208781.     }

  208782. 

  208783.     for(i=0; i<pExpr->nChild; i++){

  208784.       char *z = fts5ExprPrint(pConfig, pExpr->apChild[i]);

  208785.       if( z==0 ){

  208786.         sqlite3_free(zRet);

  208787.         zRet = 0;

  208788.       }else{

  208789.         int e = pExpr->apChild[i]->eType;

  208790.         int b = (e!=FTS5_STRING && e!=FTS5_TERM && e!=FTS5_EOF);

  208791.         zRet = fts5PrintfAppend(zRet, "%s%s%z%s", 

  208792.             (i==0 ? "" : zOp),

  208793.             (b?"(":""), z, (b?")":"")

  208794.         );

  208795.       }

  208796.       if( zRet==0 ) break;

  208797.     }

  208798.   }

  208799. 

  208800.   return zRet;

  208801. }

  208802. 

  208803. /*

  208804. ** The implementation of user-defined scalar functions fts5_expr() (bTcl==0)

  208805. ** and fts5_expr_tcl() (bTcl!=0).

  208806. */

  208807. static void fts5ExprFunction(

  208808.   sqlite3_context *pCtx,          /* Function call context */

  208809.   int nArg,                       /* Number of args */

  208810.   sqlite3_value **apVal,          /* Function arguments */

  208811.   int bTcl

  208812. ){

  208813.   Fts5Global *pGlobal = (Fts5Global*)sqlite3_user_data(pCtx);

  208814.   sqlite3 *db = sqlite3_context_db_handle(pCtx);

  208815.   const char *zExpr = 0;

  208816.   char *zErr = 0;

  208817.   Fts5Expr *pExpr = 0;

  208818.   int rc;

  208819.   int i;

  208820. 

  208821.   const char **azConfig;          /* Array of arguments for Fts5Config */

  208822.   const char *zNearsetCmd = "nearset";

  208823.   int nConfig;                    /* Size of azConfig[] */

  208824.   Fts5Config *pConfig = 0;

  208825.   int iArg = 1;

  208826. 

  208827.   if( nArg<1 ){

  208828.     zErr = sqlite3_mprintf("wrong number of arguments to function %s",

  208829.         bTcl ? "fts5_expr_tcl" : "fts5_expr"

  208830.     );

  208831.     sqlite3_result_error(pCtx, zErr, -1);

  208832.     sqlite3_free(zErr);

  208833.     return;

  208834.   }

  208835. 

  208836.   if( bTcl && nArg>1 ){

  208837.     zNearsetCmd = (const char*)sqlite3_value_text(apVal[1]);

  208838.     iArg = 2;

  208839.   }

  208840. 

  208841.   nConfig = 3 + (nArg-iArg);

  208842.   azConfig = (const char**)sqlite3_malloc64(sizeof(char*) * nConfig);

  208843.   if( azConfig==0 ){

  208844.     sqlite3_result_error_nomem(pCtx);

  208845.     return;

  208846.   }

  208847.   azConfig[0] = 0;

  208848.   azConfig[1] = "main";

  208849.   azConfig[2] = "tbl";

  208850.   for(i=3; iArg<nArg; iArg++){

  208851.     azConfig[i++] = (const char*)sqlite3_value_text(apVal[iArg]);

  208852.   }

  208853. 

  208854.   zExpr = (const char*)sqlite3_value_text(apVal[0]);

  208855. 

  208856.   rc = sqlite3Fts5ConfigParse(pGlobal, db, nConfig, azConfig, &pConfig, &zErr);

  208857.   if( rc==SQLITE_OK ){

  208858.     rc = sqlite3Fts5ExprNew(pConfig, pConfig->nCol, zExpr, &pExpr, &zErr);

  208859.   }

  208860.   if( rc==SQLITE_OK ){

  208861.     char *zText;

  208862.     if( pExpr->pRoot->xNext==0 ){

  208863.       zText = sqlite3_mprintf("");

  208864.     }else if( bTcl ){

  208865.       zText = fts5ExprPrintTcl(pConfig, zNearsetCmd, pExpr->pRoot);

  208866.     }else{

  208867.       zText = fts5ExprPrint(pConfig, pExpr->pRoot);

  208868.     }

  208869.     if( zText==0 ){

  208870.       rc = SQLITE_NOMEM;

  208871.     }else{

  208872.       sqlite3_result_text(pCtx, zText, -1, SQLITE_TRANSIENT);

  208873.       sqlite3_free(zText);

  208874.     }

  208875.   }

  208876. 

  208877.   if( rc!=SQLITE_OK ){

  208878.     if( zErr ){

  208879.       sqlite3_result_error(pCtx, zErr, -1);

  208880.       sqlite3_free(zErr);

  208881.     }else{

  208882.       sqlite3_result_error_code(pCtx, rc);

  208883.     }

  208884.   }

  208885.   sqlite3_free((void *)azConfig);

  208886.   sqlite3Fts5ConfigFree(pConfig);

  208887.   sqlite3Fts5ExprFree(pExpr);

  208888. }

  208889. 

  208890. static void fts5ExprFunctionHr(

  208891.   sqlite3_context *pCtx,          /* Function call context */

  208892.   int nArg,                       /* Number of args */

  208893.   sqlite3_value **apVal           /* Function arguments */

  208894. ){

  208895.   fts5ExprFunction(pCtx, nArg, apVal, 0);

  208896. }

  208897. static void fts5ExprFunctionTcl(

  208898.   sqlite3_context *pCtx,          /* Function call context */

  208899.   int nArg,                       /* Number of args */

  208900.   sqlite3_value **apVal           /* Function arguments */

  208901. ){

  208902.   fts5ExprFunction(pCtx, nArg, apVal, 1);

  208903. }

  208904. 

  208905. /*

  208906. ** The implementation of an SQLite user-defined-function that accepts a

  208907. ** single integer as an argument. If the integer is an alpha-numeric 

  208908. ** unicode code point, 1 is returned. Otherwise 0.

  208909. */

  208910. static void fts5ExprIsAlnum(

  208911.   sqlite3_context *pCtx,          /* Function call context */

  208912.   int nArg,                       /* Number of args */

  208913.   sqlite3_value **apVal           /* Function arguments */

  208914. ){

  208915.   int iCode;

  208916.   u8 aArr[32];

  208917.   if( nArg!=1 ){

  208918.     sqlite3_result_error(pCtx, 

  208919.         "wrong number of arguments to function fts5_isalnum", -1

  208920.     );

  208921.     return;

  208922.   }

  208923.   memset(aArr, 0, sizeof(aArr));

  208924.   sqlite3Fts5UnicodeCatParse("L*", aArr);

  208925.   sqlite3Fts5UnicodeCatParse("N*", aArr);

  208926.   sqlite3Fts5UnicodeCatParse("Co", aArr);

  208927.   iCode = sqlite3_value_int(apVal[0]);

  208928.   sqlite3_result_int(pCtx, aArr[sqlite3Fts5UnicodeCategory((u32)iCode)]);

  208929. }

  208930. 

  208931. static void fts5ExprFold(

  208932.   sqlite3_context *pCtx,          /* Function call context */

  208933.   int nArg,                       /* Number of args */

  208934.   sqlite3_value **apVal           /* Function arguments */

  208935. ){

  208936.   if( nArg!=1 && nArg!=2 ){

  208937.     sqlite3_result_error(pCtx, 

  208938.         "wrong number of arguments to function fts5_fold", -1

  208939.     );

  208940.   }else{

  208941.     int iCode;

  208942.     int bRemoveDiacritics = 0;

  208943.     iCode = sqlite3_value_int(apVal[0]);

  208944.     if( nArg==2 ) bRemoveDiacritics = sqlite3_value_int(apVal[1]);

  208945.     sqlite3_result_int(pCtx, sqlite3Fts5UnicodeFold(iCode, bRemoveDiacritics));

  208946.   }

  208947. }

  208948. 

  208949. /*

  208950. ** This is called during initialization to register the fts5_expr() scalar

  208951. ** UDF with the SQLite handle passed as the only argument.

  208952. */

  208953. static int sqlite3Fts5ExprInit(Fts5Global *pGlobal, sqlite3 *db){

  208954.   struct Fts5ExprFunc {

  208955.     const char *z;

  208956.     void (*x)(sqlite3_context*,int,sqlite3_value**);

  208957.   } aFunc[] = {

  208958.     { "fts5_expr",     fts5ExprFunctionHr },

  208959.     { "fts5_expr_tcl", fts5ExprFunctionTcl },

  208960.     { "fts5_isalnum",  fts5ExprIsAlnum },

  208961.     { "fts5_fold",     fts5ExprFold },

  208962.   };

  208963.   int i;

  208964.   int rc = SQLITE_OK;

  208965.   void *pCtx = (void*)pGlobal;

  208966. 

  208967.   for(i=0; rc==SQLITE_OK && i<ArraySize(aFunc); i++){

  208968.     struct Fts5ExprFunc *p = &aFunc[i];

  208969.     rc = sqlite3_create_function(db, p->z, -1, SQLITE_UTF8, pCtx, p->x, 0, 0);

  208970.   }

  208971. 

  208972.   /* Avoid warnings indicating that sqlite3Fts5ParserTrace() and

  208973.   ** sqlite3Fts5ParserFallback() are unused */

  208974. #ifndef NDEBUG

  208975.   (void)sqlite3Fts5ParserTrace;

  208976. #endif

  208977.   (void)sqlite3Fts5ParserFallback;

  208978. 

  208979.   return rc;

  208980. }

  208981. 

  208982. /*

  208983. ** Return the number of phrases in expression pExpr.

  208984. */

  208985. static int sqlite3Fts5ExprPhraseCount(Fts5Expr *pExpr){

  208986.   return (pExpr ? pExpr->nPhrase : 0);

  208987. }

  208988. 

  208989. /*

  208990. ** Return the number of terms in the iPhrase'th phrase in pExpr.

  208991. */

  208992. static int sqlite3Fts5ExprPhraseSize(Fts5Expr *pExpr, int iPhrase){

  208993.   if( iPhrase<0 || iPhrase>=pExpr->nPhrase ) return 0;

  208994.   return pExpr->apExprPhrase[iPhrase]->nTerm;

  208995. }

  208996. 

  208997. /*

  208998. ** This function is used to access the current position list for phrase

  208999. ** iPhrase.

  209000. */

  209001. static int sqlite3Fts5ExprPoslist(Fts5Expr *pExpr, int iPhrase, const u8 **pa){

  209002.   int nRet;

  209003.   Fts5ExprPhrase *pPhrase = pExpr->apExprPhrase[iPhrase];

  209004.   Fts5ExprNode *pNode = pPhrase->pNode;

  209005.   if( pNode->bEof==0 && pNode->iRowid==pExpr->pRoot->iRowid ){

  209006.     *pa = pPhrase->poslist.p;

  209007.     nRet = pPhrase->poslist.n;

  209008.   }else{

  209009.     *pa = 0;

  209010.     nRet = 0;

  209011.   }

  209012.   return nRet;

  209013. }

  209014. 

  209015. struct Fts5PoslistPopulator {

  209016.   Fts5PoslistWriter writer;

  209017.   int bOk;                        /* True if ok to populate */

  209018.   int bMiss;

  209019. };

  209020. 

  209021. static Fts5PoslistPopulator *sqlite3Fts5ExprClearPoslists(Fts5Expr *pExpr, int bLive){

  209022.   Fts5PoslistPopulator *pRet;

  209023.   pRet = sqlite3_malloc64(sizeof(Fts5PoslistPopulator)*pExpr->nPhrase);

  209024.   if( pRet ){

  209025.     int i;

  209026.     memset(pRet, 0, sizeof(Fts5PoslistPopulator)*pExpr->nPhrase);

  209027.     for(i=0; i<pExpr->nPhrase; i++){

  209028.       Fts5Buffer *pBuf = &pExpr->apExprPhrase[i]->poslist;

  209029.       Fts5ExprNode *pNode = pExpr->apExprPhrase[i]->pNode;

  209030.       assert( pExpr->apExprPhrase[i]->nTerm==1 );

  209031.       if( bLive && 

  209032.           (pBuf->n==0 || pNode->iRowid!=pExpr->pRoot->iRowid || pNode->bEof)

  209033.       ){

  209034.         pRet[i].bMiss = 1;

  209035.       }else{

  209036.         pBuf->n = 0;

  209037.       }

  209038.     }

  209039.   }

  209040.   return pRet;

  209041. }

  209042. 

  209043. struct Fts5ExprCtx {

  209044.   Fts5Expr *pExpr;

  209045.   Fts5PoslistPopulator *aPopulator;

  209046.   i64 iOff;

  209047. };

  209048. typedef struct Fts5ExprCtx Fts5ExprCtx;

  209049. 

  209050. /*

  209051. ** TODO: Make this more efficient!

  209052. */

  209053. static int fts5ExprColsetTest(Fts5Colset *pColset, int iCol){

  209054.   int i;

  209055.   for(i=0; i<pColset->nCol; i++){

  209056.     if( pColset->aiCol[i]==iCol ) return 1;

  209057.   }

  209058.   return 0;

  209059. }

  209060. 

  209061. static int fts5ExprPopulatePoslistsCb(

  209062.   void *pCtx,                /* Copy of 2nd argument to xTokenize() */

  209063.   int tflags,                /* Mask of FTS5_TOKEN_* flags */

  209064.   const char *pToken,        /* Pointer to buffer containing token */

  209065.   int nToken,                /* Size of token in bytes */

  209066.   int iUnused1,              /* Byte offset of token within input text */

  209067.   int iUnused2               /* Byte offset of end of token within input text */

  209068. ){

  209069.   Fts5ExprCtx *p = (Fts5ExprCtx*)pCtx;

  209070.   Fts5Expr *pExpr = p->pExpr;

  209071.   int i;

  209072. 

  209073.   UNUSED_PARAM2(iUnused1, iUnused2);

  209074. 

  209075.   if( nToken>FTS5_MAX_TOKEN_SIZE ) nToken = FTS5_MAX_TOKEN_SIZE;

  209076.   if( (tflags & FTS5_TOKEN_COLOCATED)==0 ) p->iOff++;

  209077.   for(i=0; i<pExpr->nPhrase; i++){

  209078.     Fts5ExprTerm *pTerm;

  209079.     if( p->aPopulator[i].bOk==0 ) continue;

  209080.     for(pTerm=&pExpr->apExprPhrase[i]->aTerm[0]; pTerm; pTerm=pTerm->pSynonym){

  209081.       int nTerm = (int)strlen(pTerm->zTerm);

  209082.       if( (nTerm==nToken || (nTerm<nToken && pTerm->bPrefix))

  209083.        && memcmp(pTerm->zTerm, pToken, nTerm)==0

  209084.       ){

  209085.         int rc = sqlite3Fts5PoslistWriterAppend(

  209086.             &pExpr->apExprPhrase[i]->poslist, &p->aPopulator[i].writer, p->iOff

  209087.         );

  209088.         if( rc ) return rc;

  209089.         break;

  209090.       }

  209091.     }

  209092.   }

  209093.   return SQLITE_OK;

  209094. }

  209095. 

  209096. static int sqlite3Fts5ExprPopulatePoslists(

  209097.   Fts5Config *pConfig,

  209098.   Fts5Expr *pExpr, 

  209099.   Fts5PoslistPopulator *aPopulator,

  209100.   int iCol, 

  209101.   const char *z, int n

  209102. ){

  209103.   int i;

  209104.   Fts5ExprCtx sCtx;

  209105.   sCtx.pExpr = pExpr;

  209106.   sCtx.aPopulator = aPopulator;

  209107.   sCtx.iOff = (((i64)iCol) << 32) - 1;

  209108. 

  209109.   for(i=0; i<pExpr->nPhrase; i++){

  209110.     Fts5ExprNode *pNode = pExpr->apExprPhrase[i]->pNode;

  209111.     Fts5Colset *pColset = pNode->pNear->pColset;

  209112.     if( (pColset && 0==fts5ExprColsetTest(pColset, iCol)) 

  209113.      || aPopulator[i].bMiss

  209114.     ){

  209115.       aPopulator[i].bOk = 0;

  209116.     }else{

  209117.       aPopulator[i].bOk = 1;

  209118.     }

  209119.   }

  209120. 

  209121.   return sqlite3Fts5Tokenize(pConfig, 

  209122.       FTS5_TOKENIZE_DOCUMENT, z, n, (void*)&sCtx, fts5ExprPopulatePoslistsCb

  209123.   );

  209124. }

  209125. 

  209126. static void fts5ExprClearPoslists(Fts5ExprNode *pNode){

  209127.   if( pNode->eType==FTS5_TERM || pNode->eType==FTS5_STRING ){

  209128.     pNode->pNear->apPhrase[0]->poslist.n = 0;

  209129.   }else{

  209130.     int i;

  209131.     for(i=0; i<pNode->nChild; i++){

  209132.       fts5ExprClearPoslists(pNode->apChild[i]);

  209133.     }

  209134.   }

  209135. }

  209136. 

  209137. static int fts5ExprCheckPoslists(Fts5ExprNode *pNode, i64 iRowid){

  209138.   pNode->iRowid = iRowid;

  209139.   pNode->bEof = 0;

  209140.   switch( pNode->eType ){

  209141.     case FTS5_TERM:

  209142.     case FTS5_STRING:

  209143.       return (pNode->pNear->apPhrase[0]->poslist.n>0);

  209144. 

  209145.     case FTS5_AND: {

  209146.       int i;

  209147.       for(i=0; i<pNode->nChild; i++){

  209148.         if( fts5ExprCheckPoslists(pNode->apChild[i], iRowid)==0 ){

  209149.           fts5ExprClearPoslists(pNode);

  209150.           return 0;

  209151.         }

  209152.       }

  209153.       break;

  209154.     }

  209155. 

  209156.     case FTS5_OR: {

  209157.       int i;

  209158.       int bRet = 0;

  209159.       for(i=0; i<pNode->nChild; i++){

  209160.         if( fts5ExprCheckPoslists(pNode->apChild[i], iRowid) ){

  209161.           bRet = 1;

  209162.         }

  209163.       }

  209164.       return bRet;

  209165.     }

  209166. 

  209167.     default: {

  209168.       assert( pNode->eType==FTS5_NOT );

  209169.       if( 0==fts5ExprCheckPoslists(pNode->apChild[0], iRowid)

  209170.           || 0!=fts5ExprCheckPoslists(pNode->apChild[1], iRowid)

  209171.         ){

  209172.         fts5ExprClearPoslists(pNode);

  209173.         return 0;

  209174.       }

  209175.       break;

  209176.     }

  209177.   }

  209178.   return 1;

  209179. }

  209180. 

  209181. static void sqlite3Fts5ExprCheckPoslists(Fts5Expr *pExpr, i64 iRowid){

  209182.   fts5ExprCheckPoslists(pExpr->pRoot, iRowid);

  209183. }

  209184. 

  209185. /*

  209186. ** This function is only called for detail=columns tables. 

  209187. */

  209188. static int sqlite3Fts5ExprPhraseCollist(

  209189.   Fts5Expr *pExpr, 

  209190.   int iPhrase, 

  209191.   const u8 **ppCollist, 

  209192.   int *pnCollist

  209193. ){

  209194.   Fts5ExprPhrase *pPhrase = pExpr->apExprPhrase[iPhrase];

  209195.   Fts5ExprNode *pNode = pPhrase->pNode;

  209196.   int rc = SQLITE_OK;

  209197. 

  209198.   assert( iPhrase>=0 && iPhrase<pExpr->nPhrase );

  209199.   assert( pExpr->pConfig->eDetail==FTS5_DETAIL_COLUMNS );

  209200. 

  209201.   if( pNode->bEof==0 

  209202.    && pNode->iRowid==pExpr->pRoot->iRowid 

  209203.    && pPhrase->poslist.n>0

  209204.   ){

  209205.     Fts5ExprTerm *pTerm = &pPhrase->aTerm[0];

  209206.     if( pTerm->pSynonym ){

  209207.       Fts5Buffer *pBuf = (Fts5Buffer*)&pTerm->pSynonym[1];

  209208.       rc = fts5ExprSynonymList(

  209209.           pTerm, pNode->iRowid, pBuf, (u8**)ppCollist, pnCollist

  209210.       );

  209211.     }else{

  209212.       *ppCollist = pPhrase->aTerm[0].pIter->pData;

  209213.       *pnCollist = pPhrase->aTerm[0].pIter->nData;

  209214.     }

  209215.   }else{

  209216.     *ppCollist = 0;

  209217.     *pnCollist = 0;

  209218.   }

  209219. 

  209220.   return rc;

  209221. }

  209222. 

  209223. /*

  209224. ** 2014 August 11

  209225. **

  209226. ** The author disclaims copyright to this source code.  In place of

  209227. ** a legal notice, here is a blessing:

  209228. **

  209229. **    May you do good and not evil.

  209230. **    May you find forgiveness for yourself and forgive others.

  209231. **    May you share freely, never taking more than you give.

  209232. **

  209233. ******************************************************************************

  209234. **

  209235. */

  209236. 

  209237. 

  209238. 

  209239. /* #include "fts5Int.h" */

  209240. 

  209241. typedef struct Fts5HashEntry Fts5HashEntry;

  209242. 

  209243. /*

  209244. ** This file contains the implementation of an in-memory hash table used

  209245. ** to accumuluate "term -> doclist" content before it is flused to a level-0

  209246. ** segment.

  209247. */

  209248. 

  209249. 

  209250. struct Fts5Hash {

  209251.   int eDetail;                    /* Copy of Fts5Config.eDetail */

  209252.   int *pnByte;                    /* Pointer to bytes counter */

  209253.   int nEntry;                     /* Number of entries currently in hash */

  209254.   int nSlot;                      /* Size of aSlot[] array */

  209255.   Fts5HashEntry *pScan;           /* Current ordered scan item */

  209256.   Fts5HashEntry **aSlot;          /* Array of hash slots */

  209257. };

  209258. 

  209259. /*

  209260. ** Each entry in the hash table is represented by an object of the 

  209261. ** following type. Each object, its key (a nul-terminated string) and 

  209262. ** its current data are stored in a single memory allocation. The 

  209263. ** key immediately follows the object in memory. The position list

  209264. ** data immediately follows the key data in memory.

  209265. **

  209266. ** The data that follows the key is in a similar, but not identical format

  209267. ** to the doclist data stored in the database. It is:

  209268. **

  209269. **   * Rowid, as a varint

  209270. **   * Position list, without 0x00 terminator.

  209271. **   * Size of previous position list and rowid, as a 4 byte

  209272. **     big-endian integer.

  209273. **

  209274. ** iRowidOff:

  209275. **   Offset of last rowid written to data area. Relative to first byte of

  209276. **   structure.

  209277. **

  209278. ** nData:

  209279. **   Bytes of data written since iRowidOff.

  209280. */

  209281. struct Fts5HashEntry {

  209282.   Fts5HashEntry *pHashNext;       /* Next hash entry with same hash-key */

  209283.   Fts5HashEntry *pScanNext;       /* Next entry in sorted order */

  209284.   

  209285.   int nAlloc;                     /* Total size of allocation */

  209286.   int iSzPoslist;                 /* Offset of space for 4-byte poslist size */

  209287.   int nData;                      /* Total bytes of data (incl. structure) */

  209288.   int nKey;                       /* Length of key in bytes */

  209289.   u8 bDel;                        /* Set delete-flag @ iSzPoslist */

  209290.   u8 bContent;                    /* Set content-flag (detail=none mode) */

  209291.   i16 iCol;                       /* Column of last value written */

  209292.   int iPos;                       /* Position of last value written */

  209293.   i64 iRowid;                     /* Rowid of last value written */

  209294. };

  209295. 

  209296. /*

  209297. ** Eqivalent to:

  209298. **

  209299. **   char *fts5EntryKey(Fts5HashEntry *pEntry){ return zKey; }

  209300. */

  209301. #define fts5EntryKey(p) ( ((char *)(&(p)[1])) )

  209302. 

  209303. 

  209304. /*

  209305. ** Allocate a new hash table.

  209306. */

  209307. static int sqlite3Fts5HashNew(Fts5Config *pConfig, Fts5Hash **ppNew, int *pnByte){

  209308.   int rc = SQLITE_OK;

  209309.   Fts5Hash *pNew;

  209310. 

  209311.   *ppNew = pNew = (Fts5Hash*)sqlite3_malloc(sizeof(Fts5Hash));

  209312.   if( pNew==0 ){

  209313.     rc = SQLITE_NOMEM;

  209314.   }else{

  209315.     sqlite3_int64 nByte;

  209316.     memset(pNew, 0, sizeof(Fts5Hash));

  209317.     pNew->pnByte = pnByte;

  209318.     pNew->eDetail = pConfig->eDetail;

  209319. 

  209320.     pNew->nSlot = 1024;

  209321.     nByte = sizeof(Fts5HashEntry*) * pNew->nSlot;

  209322.     pNew->aSlot = (Fts5HashEntry**)sqlite3_malloc64(nByte);

  209323.     if( pNew->aSlot==0 ){

  209324.       sqlite3_free(pNew);

  209325.       *ppNew = 0;

  209326.       rc = SQLITE_NOMEM;

  209327.     }else{

  209328.       memset(pNew->aSlot, 0, (size_t)nByte);

  209329.     }

  209330.   }

  209331.   return rc;

  209332. }

  209333. 

  209334. /*

  209335. ** Free a hash table object.

  209336. */

  209337. static void sqlite3Fts5HashFree(Fts5Hash *pHash){

  209338.   if( pHash ){

  209339.     sqlite3Fts5HashClear(pHash);

  209340.     sqlite3_free(pHash->aSlot);

  209341.     sqlite3_free(pHash);

  209342.   }

  209343. }

  209344. 

  209345. /*

  209346. ** Empty (but do not delete) a hash table.

  209347. */

  209348. static void sqlite3Fts5HashClear(Fts5Hash *pHash){

  209349.   int i;

  209350.   for(i=0; i<pHash->nSlot; i++){

  209351.     Fts5HashEntry *pNext;

  209352.     Fts5HashEntry *pSlot;

  209353.     for(pSlot=pHash->aSlot[i]; pSlot; pSlot=pNext){

  209354.       pNext = pSlot->pHashNext;

  209355.       sqlite3_free(pSlot);

  209356.     }

  209357.   }

  209358.   memset(pHash->aSlot, 0, pHash->nSlot * sizeof(Fts5HashEntry*));

  209359.   pHash->nEntry = 0;

  209360. }

  209361. 

  209362. static unsigned int fts5HashKey(int nSlot, const u8 *p, int n){

  209363.   int i;

  209364.   unsigned int h = 13;

  209365.   for(i=n-1; i>=0; i--){

  209366.     h = (h << 3) ^ h ^ p[i];

  209367.   }

  209368.   return (h % nSlot);

  209369. }

  209370. 

  209371. static unsigned int fts5HashKey2(int nSlot, u8 b, const u8 *p, int n){

  209372.   int i;

  209373.   unsigned int h = 13;

  209374.   for(i=n-1; i>=0; i--){

  209375.     h = (h << 3) ^ h ^ p[i];

  209376.   }

  209377.   h = (h << 3) ^ h ^ b;

  209378.   return (h % nSlot);

  209379. }

  209380. 

  209381. /*

  209382. ** Resize the hash table by doubling the number of slots.

  209383. */

  209384. static int fts5HashResize(Fts5Hash *pHash){

  209385.   int nNew = pHash->nSlot*2;

  209386.   int i;

  209387.   Fts5HashEntry **apNew;

  209388.   Fts5HashEntry **apOld = pHash->aSlot;

  209389. 

  209390.   apNew = (Fts5HashEntry**)sqlite3_malloc64(nNew*sizeof(Fts5HashEntry*));

  209391.   if( !apNew ) return SQLITE_NOMEM;

  209392.   memset(apNew, 0, nNew*sizeof(Fts5HashEntry*));

  209393. 

  209394.   for(i=0; i<pHash->nSlot; i++){

  209395.     while( apOld[i] ){

  209396.       unsigned int iHash;

  209397.       Fts5HashEntry *p = apOld[i];

  209398.       apOld[i] = p->pHashNext;

  209399.       iHash = fts5HashKey(nNew, (u8*)fts5EntryKey(p),

  209400.                           (int)strlen(fts5EntryKey(p)));

  209401.       p->pHashNext = apNew[iHash];

  209402.       apNew[iHash] = p;

  209403.     }

  209404.   }

  209405. 

  209406.   sqlite3_free(apOld);

  209407.   pHash->nSlot = nNew;

  209408.   pHash->aSlot = apNew;

  209409.   return SQLITE_OK;

  209410. }

  209411. 

  209412. static int fts5HashAddPoslistSize(

  209413.   Fts5Hash *pHash, 

  209414.   Fts5HashEntry *p,

  209415.   Fts5HashEntry *p2

  209416. ){

  209417.   int nRet = 0;

  209418.   if( p->iSzPoslist ){

  209419.     u8 *pPtr = p2 ? (u8*)p2 : (u8*)p;

  209420.     int nData = p->nData;

  209421.     if( pHash->eDetail==FTS5_DETAIL_NONE ){

  209422.       assert( nData==p->iSzPoslist );

  209423.       if( p->bDel ){

  209424.         pPtr[nData++] = 0x00;

  209425.         if( p->bContent ){

  209426.           pPtr[nData++] = 0x00;

  209427.         }

  209428.       }

  209429.     }else{

  209430.       int nSz = (nData - p->iSzPoslist - 1);       /* Size in bytes */

  209431.       int nPos = nSz*2 + p->bDel;                     /* Value of nPos field */

  209432. 

  209433.       assert( p->bDel==0 || p->bDel==1 );

  209434.       if( nPos<=127 ){

  209435.         pPtr[p->iSzPoslist] = (u8)nPos;

  209436.       }else{

  209437.         int nByte = sqlite3Fts5GetVarintLen((u32)nPos);

  209438.         memmove(&pPtr[p->iSzPoslist + nByte], &pPtr[p->iSzPoslist + 1], nSz);

  209439.         sqlite3Fts5PutVarint(&pPtr[p->iSzPoslist], nPos);

  209440.         nData += (nByte-1);

  209441.       }

  209442.     }

  209443. 

  209444.     nRet = nData - p->nData;

  209445.     if( p2==0 ){

  209446.       p->iSzPoslist = 0;

  209447.       p->bDel = 0;

  209448.       p->bContent = 0;

  209449.       p->nData = nData;

  209450.     }

  209451.   }

  209452.   return nRet;

  209453. }

  209454. 

  209455. /*

  209456. ** Add an entry to the in-memory hash table. The key is the concatenation

  209457. ** of bByte and (pToken/nToken). The value is (iRowid/iCol/iPos).

  209458. **

  209459. **     (bByte || pToken) -> (iRowid,iCol,iPos)

  209460. **

  209461. ** Or, if iCol is negative, then the value is a delete marker.

  209462. */

  209463. static int sqlite3Fts5HashWrite(

  209464.   Fts5Hash *pHash,

  209465.   i64 iRowid,                     /* Rowid for this entry */

  209466.   int iCol,                       /* Column token appears in (-ve -> delete) */

  209467.   int iPos,                       /* Position of token within column */

  209468.   char bByte,                     /* First byte of token */

  209469.   const char *pToken, int nToken  /* Token to add or remove to or from index */

  209470. ){

  209471.   unsigned int iHash;

  209472.   Fts5HashEntry *p;

  209473.   u8 *pPtr;

  209474.   int nIncr = 0;                  /* Amount to increment (*pHash->pnByte) by */

  209475.   int bNew;                       /* If non-delete entry should be written */

  209476.   

  209477.   bNew = (pHash->eDetail==FTS5_DETAIL_FULL);

  209478. 

  209479.   /* Attempt to locate an existing hash entry */

  209480.   iHash = fts5HashKey2(pHash->nSlot, (u8)bByte, (const u8*)pToken, nToken);

  209481.   for(p=pHash->aSlot[iHash]; p; p=p->pHashNext){

  209482.     char *zKey = fts5EntryKey(p);

  209483.     if( zKey[0]==bByte 

  209484.      && p->nKey==nToken

  209485.      && memcmp(&zKey[1], pToken, nToken)==0 

  209486.     ){

  209487.       break;

  209488.     }

  209489.   }

  209490. 

  209491.   /* If an existing hash entry cannot be found, create a new one. */

  209492.   if( p==0 ){

  209493.     /* Figure out how much space to allocate */

  209494.     char *zKey;

  209495.     sqlite3_int64 nByte = sizeof(Fts5HashEntry) + (nToken+1) + 1 + 64;

  209496.     if( nByte<128 ) nByte = 128;

  209497. 

  209498.     /* Grow the Fts5Hash.aSlot[] array if necessary. */

  209499.     if( (pHash->nEntry*2)>=pHash->nSlot ){

  209500.       int rc = fts5HashResize(pHash);

  209501.       if( rc!=SQLITE_OK ) return rc;

  209502.       iHash = fts5HashKey2(pHash->nSlot, (u8)bByte, (const u8*)pToken, nToken);

  209503.     }

  209504. 

  209505.     /* Allocate new Fts5HashEntry and add it to the hash table. */

  209506.     p = (Fts5HashEntry*)sqlite3_malloc64(nByte);

  209507.     if( !p ) return SQLITE_NOMEM;

  209508.     memset(p, 0, sizeof(Fts5HashEntry));

  209509.     p->nAlloc = (int)nByte;

  209510.     zKey = fts5EntryKey(p);

  209511.     zKey[0] = bByte;

  209512.     memcpy(&zKey[1], pToken, nToken);

  209513.     assert( iHash==fts5HashKey(pHash->nSlot, (u8*)zKey, nToken+1) );

  209514.     p->nKey = nToken;

  209515.     zKey[nToken+1] = '\0';

  209516.     p->nData = nToken+1 + 1 + sizeof(Fts5HashEntry);

  209517.     p->pHashNext = pHash->aSlot[iHash];

  209518.     pHash->aSlot[iHash] = p;

  209519.     pHash->nEntry++;

  209520. 

  209521.     /* Add the first rowid field to the hash-entry */

  209522.     p->nData += sqlite3Fts5PutVarint(&((u8*)p)[p->nData], iRowid);

  209523.     p->iRowid = iRowid;

  209524. 

  209525.     p->iSzPoslist = p->nData;

  209526.     if( pHash->eDetail!=FTS5_DETAIL_NONE ){

  209527.       p->nData += 1;

  209528.       p->iCol = (pHash->eDetail==FTS5_DETAIL_FULL ? 0 : -1);

  209529.     }

  209530. 

  209531.     nIncr += p->nData;

  209532.   }else{

  209533. 

  209534.     /* Appending to an existing hash-entry. Check that there is enough 

  209535.     ** space to append the largest possible new entry. Worst case scenario 

  209536.     ** is:

  209537.     **

  209538.     **     + 9 bytes for a new rowid,

  209539.     **     + 4 byte reserved for the "poslist size" varint.

  209540.     **     + 1 byte for a "new column" byte,

  209541.     **     + 3 bytes for a new column number (16-bit max) as a varint,

  209542.     **     + 5 bytes for the new position offset (32-bit max).

  209543.     */

  209544.     if( (p->nAlloc - p->nData) < (9 + 4 + 1 + 3 + 5) ){

  209545.       sqlite3_int64 nNew = p->nAlloc * 2;

  209546.       Fts5HashEntry *pNew;

  209547.       Fts5HashEntry **pp;

  209548.       pNew = (Fts5HashEntry*)sqlite3_realloc64(p, nNew);

  209549.       if( pNew==0 ) return SQLITE_NOMEM;

  209550.       pNew->nAlloc = (int)nNew;

  209551.       for(pp=&pHash->aSlot[iHash]; *pp!=p; pp=&(*pp)->pHashNext);

  209552.       *pp = pNew;

  209553.       p = pNew;

  209554.     }

  209555.     nIncr -= p->nData;

  209556.   }

  209557.   assert( (p->nAlloc - p->nData) >= (9 + 4 + 1 + 3 + 5) );

  209558. 

  209559.   pPtr = (u8*)p;

  209560. 

  209561.   /* If this is a new rowid, append the 4-byte size field for the previous

  209562.   ** entry, and the new rowid for this entry.  */

  209563.   if( iRowid!=p->iRowid ){

  209564.     fts5HashAddPoslistSize(pHash, p, 0);

  209565.     p->nData += sqlite3Fts5PutVarint(&pPtr[p->nData], iRowid - p->iRowid);

  209566.     p->iRowid = iRowid;

  209567.     bNew = 1;

  209568.     p->iSzPoslist = p->nData;

  209569.     if( pHash->eDetail!=FTS5_DETAIL_NONE ){

  209570.       p->nData += 1;

  209571.       p->iCol = (pHash->eDetail==FTS5_DETAIL_FULL ? 0 : -1);

  209572.       p->iPos = 0;

  209573.     }

  209574.   }

  209575. 

  209576.   if( iCol>=0 ){

  209577.     if( pHash->eDetail==FTS5_DETAIL_NONE ){

  209578.       p->bContent = 1;

  209579.     }else{

  209580.       /* Append a new column value, if necessary */

  209581.       assert( iCol>=p->iCol );

  209582.       if( iCol!=p->iCol ){

  209583.         if( pHash->eDetail==FTS5_DETAIL_FULL ){

  209584.           pPtr[p->nData++] = 0x01;

  209585.           p->nData += sqlite3Fts5PutVarint(&pPtr[p->nData], iCol);

  209586.           p->iCol = (i16)iCol;

  209587.           p->iPos = 0;

  209588.         }else{

  209589.           bNew = 1;

  209590.           p->iCol = (i16)(iPos = iCol);

  209591.         }

  209592.       }

  209593. 

  209594.       /* Append the new position offset, if necessary */

  209595.       if( bNew ){

  209596.         p->nData += sqlite3Fts5PutVarint(&pPtr[p->nData], iPos - p->iPos + 2);

  209597.         p->iPos = iPos;

  209598.       }

  209599.     }

  209600.   }else{

  209601.     /* This is a delete. Set the delete flag. */

  209602.     p->bDel = 1;

  209603.   }

  209604. 

  209605.   nIncr += p->nData;

  209606.   *pHash->pnByte += nIncr;

  209607.   return SQLITE_OK;

  209608. }

  209609. 

  209610. 

  209611. /*

  209612. ** Arguments pLeft and pRight point to linked-lists of hash-entry objects,

  209613. ** each sorted in key order. This function merges the two lists into a

  209614. ** single list and returns a pointer to its first element.

  209615. */

  209616. static Fts5HashEntry *fts5HashEntryMerge(

  209617.   Fts5HashEntry *pLeft,

  209618.   Fts5HashEntry *pRight

  209619. ){

  209620.   Fts5HashEntry *p1 = pLeft;

  209621.   Fts5HashEntry *p2 = pRight;

  209622.   Fts5HashEntry *pRet = 0;

  209623.   Fts5HashEntry **ppOut = &pRet;

  209624. 

  209625.   while( p1 || p2 ){

  209626.     if( p1==0 ){

  209627.       *ppOut = p2;

  209628.       p2 = 0;

  209629.     }else if( p2==0 ){

  209630.       *ppOut = p1;

  209631.       p1 = 0;

  209632.     }else{

  209633.       int i = 0;

  209634.       char *zKey1 = fts5EntryKey(p1);

  209635.       char *zKey2 = fts5EntryKey(p2);

  209636.       while( zKey1[i]==zKey2[i] ) i++;

  209637. 

  209638.       if( ((u8)zKey1[i])>((u8)zKey2[i]) ){

  209639.         /* p2 is smaller */

  209640.         *ppOut = p2;

  209641.         ppOut = &p2->pScanNext;

  209642.         p2 = p2->pScanNext;

  209643.       }else{

  209644.         /* p1 is smaller */

  209645.         *ppOut = p1;

  209646.         ppOut = &p1->pScanNext;

  209647.         p1 = p1->pScanNext;

  209648.       }

  209649.       *ppOut = 0;

  209650.     }

  209651.   }

  209652. 

  209653.   return pRet;

  209654. }

  209655. 

  209656. /*

  209657. ** Extract all tokens from hash table iHash and link them into a list

  209658. ** in sorted order. The hash table is cleared before returning. It is

  209659. ** the responsibility of the caller to free the elements of the returned

  209660. ** list.

  209661. */

  209662. static int fts5HashEntrySort(

  209663.   Fts5Hash *pHash, 

  209664.   const char *pTerm, int nTerm,   /* Query prefix, if any */

  209665.   Fts5HashEntry **ppSorted

  209666. ){

  209667.   const int nMergeSlot = 32;

  209668.   Fts5HashEntry **ap;

  209669.   Fts5HashEntry *pList;

  209670.   int iSlot;

  209671.   int i;

  209672. 

  209673.   *ppSorted = 0;

  209674.   ap = sqlite3_malloc64(sizeof(Fts5HashEntry*) * nMergeSlot);

  209675.   if( !ap ) return SQLITE_NOMEM;

  209676.   memset(ap, 0, sizeof(Fts5HashEntry*) * nMergeSlot);

  209677. 

  209678.   for(iSlot=0; iSlot<pHash->nSlot; iSlot++){

  209679.     Fts5HashEntry *pIter;

  209680.     for(pIter=pHash->aSlot[iSlot]; pIter; pIter=pIter->pHashNext){

  209681.       if( pTerm==0 

  209682.        || (pIter->nKey+1>=nTerm && 0==memcmp(fts5EntryKey(pIter), pTerm, nTerm))

  209683.       ){

  209684.         Fts5HashEntry *pEntry = pIter;

  209685.         pEntry->pScanNext = 0;

  209686.         for(i=0; ap[i]; i++){

  209687.           pEntry = fts5HashEntryMerge(pEntry, ap[i]);

  209688.           ap[i] = 0;

  209689.         }

  209690.         ap[i] = pEntry;

  209691.       }

  209692.     }

  209693.   }

  209694. 

  209695.   pList = 0;

  209696.   for(i=0; i<nMergeSlot; i++){

  209697.     pList = fts5HashEntryMerge(pList, ap[i]);

  209698.   }

  209699. 

  209700.   pHash->nEntry = 0;

  209701.   sqlite3_free(ap);

  209702.   *ppSorted = pList;

  209703.   return SQLITE_OK;

  209704. }

  209705. 

  209706. /*

  209707. ** Query the hash table for a doclist associated with term pTerm/nTerm.

  209708. */

  209709. static int sqlite3Fts5HashQuery(

  209710.   Fts5Hash *pHash,                /* Hash table to query */

  209711.   int nPre,

  209712.   const char *pTerm, int nTerm,   /* Query term */

  209713.   void **ppOut,                   /* OUT: Pointer to new object */

  209714.   int *pnDoclist                  /* OUT: Size of doclist in bytes */

  209715. ){

  209716.   unsigned int iHash = fts5HashKey(pHash->nSlot, (const u8*)pTerm, nTerm);

  209717.   char *zKey = 0;

  209718.   Fts5HashEntry *p;

  209719. 

  209720.   for(p=pHash->aSlot[iHash]; p; p=p->pHashNext){

  209721.     zKey = fts5EntryKey(p);

  209722.     assert( p->nKey+1==(int)strlen(zKey) );

  209723.     if( nTerm==p->nKey+1 && memcmp(zKey, pTerm, nTerm)==0 ) break;

  209724.   }

  209725. 

  209726.   if( p ){

  209727.     int nHashPre = sizeof(Fts5HashEntry) + nTerm + 1;

  209728.     int nList = p->nData - nHashPre;

  209729.     u8 *pRet = (u8*)(*ppOut = sqlite3_malloc64(nPre + nList + 10));

  209730.     if( pRet ){

  209731.       Fts5HashEntry *pFaux = (Fts5HashEntry*)&pRet[nPre-nHashPre];

  209732.       memcpy(&pRet[nPre], &((u8*)p)[nHashPre], nList);

  209733.       nList += fts5HashAddPoslistSize(pHash, p, pFaux);

  209734.       *pnDoclist = nList;

  209735.     }else{

  209736.       *pnDoclist = 0;

  209737.       return SQLITE_NOMEM;

  209738.     }

  209739.   }else{

  209740.     *ppOut = 0;

  209741.     *pnDoclist = 0;

  209742.   }

  209743. 

  209744.   return SQLITE_OK;

  209745. }

  209746. 

  209747. static int sqlite3Fts5HashScanInit(

  209748.   Fts5Hash *p,                    /* Hash table to query */

  209749.   const char *pTerm, int nTerm    /* Query prefix */

  209750. ){

  209751.   return fts5HashEntrySort(p, pTerm, nTerm, &p->pScan);

  209752. }

  209753. 

  209754. static void sqlite3Fts5HashScanNext(Fts5Hash *p){

  209755.   assert( !sqlite3Fts5HashScanEof(p) );

  209756.   p->pScan = p->pScan->pScanNext;

  209757. }

  209758. 

  209759. static int sqlite3Fts5HashScanEof(Fts5Hash *p){

  209760.   return (p->pScan==0);

  209761. }

  209762. 

  209763. static void sqlite3Fts5HashScanEntry(

  209764.   Fts5Hash *pHash,

  209765.   const char **pzTerm,            /* OUT: term (nul-terminated) */

  209766.   const u8 **ppDoclist,           /* OUT: pointer to doclist */

  209767.   int *pnDoclist                  /* OUT: size of doclist in bytes */

  209768. ){

  209769.   Fts5HashEntry *p;

  209770.   if( (p = pHash->pScan) ){

  209771.     char *zKey = fts5EntryKey(p);

  209772.     int nTerm = (int)strlen(zKey);

  209773.     fts5HashAddPoslistSize(pHash, p, 0);

  209774.     *pzTerm = zKey;

  209775.     *ppDoclist = (const u8*)&zKey[nTerm+1];

  209776.     *pnDoclist = p->nData - (sizeof(Fts5HashEntry) + nTerm + 1);

  209777.   }else{

  209778.     *pzTerm = 0;

  209779.     *ppDoclist = 0;

  209780.     *pnDoclist = 0;

  209781.   }

  209782. }

  209783. 

  209784. /*

  209785. ** 2014 May 31

  209786. **

  209787. ** The author disclaims copyright to this source code.  In place of

  209788. ** a legal notice, here is a blessing:

  209789. **

  209790. **    May you do good and not evil.

  209791. **    May you find forgiveness for yourself and forgive others.

  209792. **    May you share freely, never taking more than you give.

  209793. **

  209794. ******************************************************************************

  209795. **

  209796. ** Low level access to the FTS index stored in the database file. The 

  209797. ** routines in this file file implement all read and write access to the

  209798. ** %_data table. Other parts of the system access this functionality via

  209799. ** the interface defined in fts5Int.h.

  209800. */

  209801. 

  209802. 

  209803. /* #include "fts5Int.h" */

  209804. 

  209805. /*

  209806. ** Overview:

  209807. **

  209808. ** The %_data table contains all the FTS indexes for an FTS5 virtual table.

  209809. ** As well as the main term index, there may be up to 31 prefix indexes.

  209810. ** The format is similar to FTS3/4, except that:

  209811. **

  209812. **   * all segment b-tree leaf data is stored in fixed size page records 

  209813. **     (e.g. 1000 bytes). A single doclist may span multiple pages. Care is 

  209814. **     taken to ensure it is possible to iterate in either direction through 

  209815. **     the entries in a doclist, or to seek to a specific entry within a 

  209816. **     doclist, without loading it into memory.

  209817. **

  209818. **   * large doclists that span many pages have associated "doclist index"

  209819. **     records that contain a copy of the first rowid on each page spanned by

  209820. **     the doclist. This is used to speed up seek operations, and merges of

  209821. **     large doclists with very small doclists.

  209822. **

  209823. **   * extra fields in the "structure record" record the state of ongoing

  209824. **     incremental merge operations.

  209825. **

  209826. */

  209827. 

  209828. 

  209829. #define FTS5_OPT_WORK_UNIT  1000  /* Number of leaf pages per optimize step */

  209830. #define FTS5_WORK_UNIT      64    /* Number of leaf pages in unit of work */

  209831. 

  209832. #define FTS5_MIN_DLIDX_SIZE 4     /* Add dlidx if this many empty pages */

  209833. 

  209834. #define FTS5_MAIN_PREFIX '0'

  209835. 

  209836. #if FTS5_MAX_PREFIX_INDEXES > 31

  209837. # error "FTS5_MAX_PREFIX_INDEXES is too large"

  209838. #endif

  209839. 

  209840. /*

  209841. ** Details:

  209842. **

  209843. ** The %_data table managed by this module,

  209844. **

  209845. **     CREATE TABLE %_data(id INTEGER PRIMARY KEY, block BLOB);

  209846. **

  209847. ** , contains the following 5 types of records. See the comments surrounding

  209848. ** the FTS5_*_ROWID macros below for a description of how %_data rowids are 

  209849. ** assigned to each fo them.

  209850. **

  209851. ** 1. Structure Records:

  209852. **

  209853. **   The set of segments that make up an index - the index structure - are

  209854. **   recorded in a single record within the %_data table. The record consists

  209855. **   of a single 32-bit configuration cookie value followed by a list of 

  209856. **   SQLite varints. If the FTS table features more than one index (because

  209857. **   there are one or more prefix indexes), it is guaranteed that all share

  209858. **   the same cookie value.

  209859. **

  209860. **   Immediately following the configuration cookie, the record begins with

  209861. **   three varints:

  209862. **

  209863. **     + number of levels,

  209864. **     + total number of segments on all levels,

  209865. **     + value of write counter.

  209866. **

  209867. **   Then, for each level from 0 to nMax:

  209868. **

  209869. **     + number of input segments in ongoing merge.

  209870. **     + total number of segments in level.

  209871. **     + for each segment from oldest to newest:

  209872. **         + segment id (always > 0)

  209873. **         + first leaf page number (often 1, always greater than 0)

  209874. **         + final leaf page number

  209875. **

  209876. ** 2. The Averages Record:

  209877. **

  209878. **   A single record within the %_data table. The data is a list of varints.

  209879. **   The first value is the number of rows in the index. Then, for each column

  209880. **   from left to right, the total number of tokens in the column for all

  209881. **   rows of the table.

  209882. **

  209883. ** 3. Segment leaves:

  209884. **

  209885. **   TERM/DOCLIST FORMAT:

  209886. **

  209887. **     Most of each segment leaf is taken up by term/doclist data. The 

  209888. **     general format of term/doclist, starting with the first term

  209889. **     on the leaf page, is:

  209890. **

  209891. **         varint : size of first term

  209892. **         blob:    first term data

  209893. **         doclist: first doclist

  209894. **         zero-or-more {

  209895. **           varint:  number of bytes in common with previous term

  209896. **           varint:  number of bytes of new term data (nNew)

  209897. **           blob:    nNew bytes of new term data

  209898. **           doclist: next doclist

  209899. **         }

  209900. **

  209901. **     doclist format:

  209902. **

  209903. **         varint:  first rowid

  209904. **         poslist: first poslist

  209905. **         zero-or-more {

  209906. **           varint:  rowid delta (always > 0)

  209907. **           poslist: next poslist

  209908. **         }

  209909. **

  209910. **     poslist format:

  209911. **

  209912. **         varint: size of poslist in bytes multiplied by 2, not including

  209913. **                 this field. Plus 1 if this entry carries the "delete" flag.

  209914. **         collist: collist for column 0

  209915. **         zero-or-more {

  209916. **           0x01 byte

  209917. **           varint: column number (I)

  209918. **           collist: collist for column I

  209919. **         }

  209920. **

  209921. **     collist format:

  209922. **

  209923. **         varint: first offset + 2

  209924. **         zero-or-more {

  209925. **           varint: offset delta + 2

  209926. **         }

  209927. **

  209928. **   PAGE FORMAT

  209929. **

  209930. **     Each leaf page begins with a 4-byte header containing 2 16-bit 

  209931. **     unsigned integer fields in big-endian format. They are:

  209932. **

  209933. **       * The byte offset of the first rowid on the page, if it exists

  209934. **         and occurs before the first term (otherwise 0).

  209935. **

  209936. **       * The byte offset of the start of the page footer. If the page

  209937. **         footer is 0 bytes in size, then this field is the same as the

  209938. **         size of the leaf page in bytes.

  209939. **

  209940. **     The page footer consists of a single varint for each term located

  209941. **     on the page. Each varint is the byte offset of the current term

  209942. **     within the page, delta-compressed against the previous value. In

  209943. **     other words, the first varint in the footer is the byte offset of

  209944. **     the first term, the second is the byte offset of the second less that

  209945. **     of the first, and so on.

  209946. **

  209947. **     The term/doclist format described above is accurate if the entire

  209948. **     term/doclist data fits on a single leaf page. If this is not the case,

  209949. **     the format is changed in two ways:

  209950. **

  209951. **       + if the first rowid on a page occurs before the first term, it

  209952. **         is stored as a literal value:

  209953. **

  209954. **             varint:  first rowid

  209955. **

  209956. **       + the first term on each page is stored in the same way as the

  209957. **         very first term of the segment:

  209958. **

  209959. **             varint : size of first term

  209960. **             blob:    first term data

  209961. **

  209962. ** 5. Segment doclist indexes:

  209963. **

  209964. **   Doclist indexes are themselves b-trees, however they usually consist of

  209965. **   a single leaf record only. The format of each doclist index leaf page 

  209966. **   is:

  209967. **

  209968. **     * Flags byte. Bits are:

  209969. **         0x01: Clear if leaf is also the root page, otherwise set.

  209970. **

  209971. **     * Page number of fts index leaf page. As a varint.

  209972. **

  209973. **     * First rowid on page indicated by previous field. As a varint.

  209974. **

  209975. **     * A list of varints, one for each subsequent termless page. A 

  209976. **       positive delta if the termless page contains at least one rowid, 

  209977. **       or an 0x00 byte otherwise.

  209978. **

  209979. **   Internal doclist index nodes are:

  209980. **

  209981. **     * Flags byte. Bits are:

  209982. **         0x01: Clear for root page, otherwise set.

  209983. **

  209984. **     * Page number of first child page. As a varint.

  209985. **

  209986. **     * Copy of first rowid on page indicated by previous field. As a varint.

  209987. **

  209988. **     * A list of delta-encoded varints - the first rowid on each subsequent

  209989. **       child page. 

  209990. **

  209991. */

  209992. 

  209993. /*

  209994. ** Rowids for the averages and structure records in the %_data table.

  209995. */

  209996. #define FTS5_AVERAGES_ROWID     1    /* Rowid used for the averages record */

  209997. #define FTS5_STRUCTURE_ROWID   10    /* The structure record */

  209998. 

  209999. /*

  210000. ** Macros determining the rowids used by segment leaves and dlidx leaves

  210001. ** and nodes. All nodes and leaves are stored in the %_data table with large

  210002. ** positive rowids.

  210003. **

  210004. ** Each segment has a unique non-zero 16-bit id.

  210005. **

  210006. ** The rowid for each segment leaf is found by passing the segment id and 

  210007. ** the leaf page number to the FTS5_SEGMENT_ROWID macro. Leaves are numbered

  210008. ** sequentially starting from 1.

  210009. */

  210010. #define FTS5_DATA_ID_B     16     /* Max seg id number 65535 */

  210011. #define FTS5_DATA_DLI_B     1     /* Doclist-index flag (1 bit) */

  210012. #define FTS5_DATA_HEIGHT_B  5     /* Max dlidx tree height of 32 */

  210013. #define FTS5_DATA_PAGE_B   31     /* Max page number of 2147483648 */

  210014. 

  210015. #define fts5_dri(segid, dlidx, height, pgno) (                                 \

  210016.  ((i64)(segid)  << (FTS5_DATA_PAGE_B+FTS5_DATA_HEIGHT_B+FTS5_DATA_DLI_B)) +    \

  210017.  ((i64)(dlidx)  << (FTS5_DATA_PAGE_B + FTS5_DATA_HEIGHT_B)) +                  \

  210018.  ((i64)(height) << (FTS5_DATA_PAGE_B)) +                                       \

  210019.  ((i64)(pgno))                                                                 \

  210020. )

  210021. 

  210022. #define FTS5_SEGMENT_ROWID(segid, pgno)       fts5_dri(segid, 0, 0, pgno)

  210023. #define FTS5_DLIDX_ROWID(segid, height, pgno) fts5_dri(segid, 1, height, pgno)

  210024. 

  210025. /*

  210026. ** Maximum segments permitted in a single index 

  210027. */

  210028. #define FTS5_MAX_SEGMENT 2000

  210029. 

  210030. #ifdef SQLITE_DEBUG

  210031. static int sqlite3Fts5Corrupt() { return SQLITE_CORRUPT_VTAB; }

  210032. #endif

  210033. 

  210034. 

  210035. /*

  210036. ** Each time a blob is read from the %_data table, it is padded with this

  210037. ** many zero bytes. This makes it easier to decode the various record formats

  210038. ** without overreading if the records are corrupt.

  210039. */

  210040. #define FTS5_DATA_ZERO_PADDING 8

  210041. #define FTS5_DATA_PADDING 20

  210042. 

  210043. typedef struct Fts5Data Fts5Data;

  210044. typedef struct Fts5DlidxIter Fts5DlidxIter;

  210045. typedef struct Fts5DlidxLvl Fts5DlidxLvl;

  210046. typedef struct Fts5DlidxWriter Fts5DlidxWriter;

  210047. typedef struct Fts5Iter Fts5Iter;

  210048. typedef struct Fts5PageWriter Fts5PageWriter;

  210049. typedef struct Fts5SegIter Fts5SegIter;

  210050. typedef struct Fts5DoclistIter Fts5DoclistIter;

  210051. typedef struct Fts5SegWriter Fts5SegWriter;

  210052. typedef struct Fts5Structure Fts5Structure;

  210053. typedef struct Fts5StructureLevel Fts5StructureLevel;

  210054. typedef struct Fts5StructureSegment Fts5StructureSegment;

  210055. 

  210056. struct Fts5Data {

  210057.   u8 *p;                          /* Pointer to buffer containing record */

  210058.   int nn;                         /* Size of record in bytes */

  210059.   int szLeaf;                     /* Size of leaf without page-index */

  210060. };

  210061. 

  210062. /*

  210063. ** One object per %_data table.

  210064. */

  210065. struct Fts5Index {

  210066.   Fts5Config *pConfig;            /* Virtual table configuration */

  210067.   char *zDataTbl;                 /* Name of %_data table */

  210068.   int nWorkUnit;                  /* Leaf pages in a "unit" of work */

  210069. 

  210070.   /*

  210071.   ** Variables related to the accumulation of tokens and doclists within the

  210072.   ** in-memory hash tables before they are flushed to disk.

  210073.   */

  210074.   Fts5Hash *pHash;                /* Hash table for in-memory data */

  210075.   int nPendingData;               /* Current bytes of pending data */

  210076.   i64 iWriteRowid;                /* Rowid for current doc being written */

  210077.   int bDelete;                    /* Current write is a delete */

  210078. 

  210079.   /* Error state. */

  210080.   int rc;                         /* Current error code */

  210081. 

  210082.   /* State used by the fts5DataXXX() functions. */

  210083.   sqlite3_blob *pReader;          /* RO incr-blob open on %_data table */

  210084.   sqlite3_stmt *pWriter;          /* "INSERT ... %_data VALUES(?,?)" */

  210085.   sqlite3_stmt *pDeleter;         /* "DELETE FROM %_data ... id>=? AND id<=?" */

  210086.   sqlite3_stmt *pIdxWriter;       /* "INSERT ... %_idx VALUES(?,?,?,?)" */

  210087.   sqlite3_stmt *pIdxDeleter;      /* "DELETE FROM %_idx WHERE segid=? */

  210088.   sqlite3_stmt *pIdxSelect;

  210089.   int nRead;                      /* Total number of blocks read */

  210090. 

  210091.   sqlite3_stmt *pDataVersion;

  210092.   i64 iStructVersion;             /* data_version when pStruct read */

  210093.   Fts5Structure *pStruct;         /* Current db structure (or NULL) */

  210094. };

  210095. 

  210096. struct Fts5DoclistIter {

  210097.   u8 *aEof;                       /* Pointer to 1 byte past end of doclist */

  210098. 

  210099.   /* Output variables. aPoslist==0 at EOF */

  210100.   i64 iRowid;

  210101.   u8 *aPoslist;

  210102.   int nPoslist;

  210103.   int nSize;

  210104. };

  210105. 

  210106. /*

  210107. ** The contents of the "structure" record for each index are represented

  210108. ** using an Fts5Structure record in memory. Which uses instances of the 

  210109. ** other Fts5StructureXXX types as components.

  210110. */

  210111. struct Fts5StructureSegment {

  210112.   int iSegid;                     /* Segment id */

  210113.   int pgnoFirst;                  /* First leaf page number in segment */

  210114.   int pgnoLast;                   /* Last leaf page number in segment */

  210115. };

  210116. struct Fts5StructureLevel {

  210117.   int nMerge;                     /* Number of segments in incr-merge */

  210118.   int nSeg;                       /* Total number of segments on level */

  210119.   Fts5StructureSegment *aSeg;     /* Array of segments. aSeg[0] is oldest. */

  210120. };

  210121. struct Fts5Structure {

  210122.   int nRef;                       /* Object reference count */

  210123.   u64 nWriteCounter;              /* Total leaves written to level 0 */

  210124.   int nSegment;                   /* Total segments in this structure */

  210125.   int nLevel;                     /* Number of levels in this index */

  210126.   Fts5StructureLevel aLevel[1];   /* Array of nLevel level objects */

  210127. };

  210128. 

  210129. /*

  210130. ** An object of type Fts5SegWriter is used to write to segments.

  210131. */

  210132. struct Fts5PageWriter {

  210133.   int pgno;                       /* Page number for this page */

  210134.   int iPrevPgidx;                 /* Previous value written into pgidx */

  210135.   Fts5Buffer buf;                 /* Buffer containing leaf data */

  210136.   Fts5Buffer pgidx;               /* Buffer containing page-index */

  210137.   Fts5Buffer term;                /* Buffer containing previous term on page */

  210138. };

  210139. struct Fts5DlidxWriter {

  210140.   int pgno;                       /* Page number for this page */

  210141.   int bPrevValid;                 /* True if iPrev is valid */

  210142.   i64 iPrev;                      /* Previous rowid value written to page */

  210143.   Fts5Buffer buf;                 /* Buffer containing page data */

  210144. };

  210145. struct Fts5SegWriter {

  210146.   int iSegid;                     /* Segid to write to */

  210147.   Fts5PageWriter writer;          /* PageWriter object */

  210148.   i64 iPrevRowid;                 /* Previous rowid written to current leaf */

  210149.   u8 bFirstRowidInDoclist;        /* True if next rowid is first in doclist */

  210150.   u8 bFirstRowidInPage;           /* True if next rowid is first in page */

  210151.   /* TODO1: Can use (writer.pgidx.n==0) instead of bFirstTermInPage */

  210152.   u8 bFirstTermInPage;            /* True if next term will be first in leaf */

  210153.   int nLeafWritten;               /* Number of leaf pages written */

  210154.   int nEmpty;                     /* Number of contiguous term-less nodes */

  210155. 

  210156.   int nDlidx;                     /* Allocated size of aDlidx[] array */

  210157.   Fts5DlidxWriter *aDlidx;        /* Array of Fts5DlidxWriter objects */

  210158. 

  210159.   /* Values to insert into the %_idx table */

  210160.   Fts5Buffer btterm;              /* Next term to insert into %_idx table */

  210161.   int iBtPage;                    /* Page number corresponding to btterm */

  210162. };

  210163. 

  210164. typedef struct Fts5CResult Fts5CResult;

  210165. struct Fts5CResult {

  210166.   u16 iFirst;                     /* aSeg[] index of firstest iterator */

  210167.   u8 bTermEq;                     /* True if the terms are equal */

  210168. };

  210169. 

  210170. /*

  210171. ** Object for iterating through a single segment, visiting each term/rowid

  210172. ** pair in the segment.

  210173. **

  210174. ** pSeg:

  210175. **   The segment to iterate through.

  210176. **

  210177. ** iLeafPgno:

  210178. **   Current leaf page number within segment.

  210179. **

  210180. ** iLeafOffset:

  210181. **   Byte offset within the current leaf that is the first byte of the 

  210182. **   position list data (one byte passed the position-list size field).

  210183. **   rowid field of the current entry. Usually this is the size field of the

  210184. **   position list data. The exception is if the rowid for the current entry 

  210185. **   is the last thing on the leaf page.

  210186. **

  210187. ** pLeaf:

  210188. **   Buffer containing current leaf page data. Set to NULL at EOF.

  210189. **

  210190. ** iTermLeafPgno, iTermLeafOffset:

  210191. **   Leaf page number containing the last term read from the segment. And

  210192. **   the offset immediately following the term data.

  210193. **

  210194. ** flags:

  210195. **   Mask of FTS5_SEGITER_XXX values. Interpreted as follows:

  210196. **

  210197. **   FTS5_SEGITER_ONETERM:

  210198. **     If set, set the iterator to point to EOF after the current doclist 

  210199. **     has been exhausted. Do not proceed to the next term in the segment.

  210200. **

  210201. **   FTS5_SEGITER_REVERSE:

  210202. **     This flag is only ever set if FTS5_SEGITER_ONETERM is also set. If

  210203. **     it is set, iterate through rowid in descending order instead of the

  210204. **     default ascending order.

  210205. **

  210206. ** iRowidOffset/nRowidOffset/aRowidOffset:

  210207. **     These are used if the FTS5_SEGITER_REVERSE flag is set.

  210208. **

  210209. **     For each rowid on the page corresponding to the current term, the

  210210. **     corresponding aRowidOffset[] entry is set to the byte offset of the

  210211. **     start of the "position-list-size" field within the page.

  210212. **

  210213. ** iTermIdx:

  210214. **     Index of current term on iTermLeafPgno.

  210215. */

  210216. struct Fts5SegIter {

  210217.   Fts5StructureSegment *pSeg;     /* Segment to iterate through */

  210218.   int flags;                      /* Mask of configuration flags */

  210219.   int iLeafPgno;                  /* Current leaf page number */

  210220.   Fts5Data *pLeaf;                /* Current leaf data */

  210221.   Fts5Data *pNextLeaf;            /* Leaf page (iLeafPgno+1) */

  210222.   int iLeafOffset;                /* Byte offset within current leaf */

  210223. 

  210224.   /* Next method */

  210225.   void (*xNext)(Fts5Index*, Fts5SegIter*, int*);

  210226. 

  210227.   /* The page and offset from which the current term was read. The offset 

  210228.   ** is the offset of the first rowid in the current doclist.  */

  210229.   int iTermLeafPgno;

  210230.   int iTermLeafOffset;

  210231. 

  210232.   int iPgidxOff;                  /* Next offset in pgidx */

  210233.   int iEndofDoclist;

  210234. 

  210235.   /* The following are only used if the FTS5_SEGITER_REVERSE flag is set. */

  210236.   int iRowidOffset;               /* Current entry in aRowidOffset[] */

  210237.   int nRowidOffset;               /* Allocated size of aRowidOffset[] array */

  210238.   int *aRowidOffset;              /* Array of offset to rowid fields */

  210239. 

  210240.   Fts5DlidxIter *pDlidx;          /* If there is a doclist-index */

  210241. 

  210242.   /* Variables populated based on current entry. */

  210243.   Fts5Buffer term;                /* Current term */

  210244.   i64 iRowid;                     /* Current rowid */

  210245.   int nPos;                       /* Number of bytes in current position list */

  210246.   u8 bDel;                        /* True if the delete flag is set */

  210247. };

  210248. 

  210249. /*

  210250. ** Argument is a pointer to an Fts5Data structure that contains a 

  210251. ** leaf page.

  210252. */

  210253. #define ASSERT_SZLEAF_OK(x) assert( \

  210254.     (x)->szLeaf==(x)->nn || (x)->szLeaf==fts5GetU16(&(x)->p[2]) \

  210255. )

  210256. 

  210257. #define FTS5_SEGITER_ONETERM 0x01

  210258. #define FTS5_SEGITER_REVERSE 0x02

  210259. 

  210260. /* 

  210261. ** Argument is a pointer to an Fts5Data structure that contains a leaf

  210262. ** page. This macro evaluates to true if the leaf contains no terms, or

  210263. ** false if it contains at least one term.

  210264. */

  210265. #define fts5LeafIsTermless(x) ((x)->szLeaf >= (x)->nn)

  210266. 

  210267. #define fts5LeafTermOff(x, i) (fts5GetU16(&(x)->p[(x)->szLeaf + (i)*2]))

  210268. 

  210269. #define fts5LeafFirstRowidOff(x) (fts5GetU16((x)->p))

  210270. 

  210271. /*

  210272. ** Object for iterating through the merged results of one or more segments,

  210273. ** visiting each term/rowid pair in the merged data.

  210274. **

  210275. ** nSeg is always a power of two greater than or equal to the number of

  210276. ** segments that this object is merging data from. Both the aSeg[] and

  210277. ** aFirst[] arrays are sized at nSeg entries. The aSeg[] array is padded

  210278. ** with zeroed objects - these are handled as if they were iterators opened

  210279. ** on empty segments.

  210280. **

  210281. ** The results of comparing segments aSeg[N] and aSeg[N+1], where N is an

  210282. ** even number, is stored in aFirst[(nSeg+N)/2]. The "result" of the 

  210283. ** comparison in this context is the index of the iterator that currently

  210284. ** points to the smaller term/rowid combination. Iterators at EOF are

  210285. ** considered to be greater than all other iterators.

  210286. **

  210287. ** aFirst[1] contains the index in aSeg[] of the iterator that points to

  210288. ** the smallest key overall. aFirst[0] is unused. 

  210289. **

  210290. ** poslist:

  210291. **   Used by sqlite3Fts5IterPoslist() when the poslist needs to be buffered.

  210292. **   There is no way to tell if this is populated or not.

  210293. */

  210294. struct Fts5Iter {

  210295.   Fts5IndexIter base;             /* Base class containing output vars */

  210296. 

  210297.   Fts5Index *pIndex;              /* Index that owns this iterator */

  210298.   Fts5Buffer poslist;             /* Buffer containing current poslist */

  210299.   Fts5Colset *pColset;            /* Restrict matches to these columns */

  210300. 

  210301.   /* Invoked to set output variables. */

  210302.   void (*xSetOutputs)(Fts5Iter*, Fts5SegIter*);

  210303. 

  210304.   int nSeg;                       /* Size of aSeg[] array */

  210305.   int bRev;                       /* True to iterate in reverse order */

  210306.   u8 bSkipEmpty;                  /* True to skip deleted entries */

  210307. 

  210308.   i64 iSwitchRowid;               /* Firstest rowid of other than aFirst[1] */

  210309.   Fts5CResult *aFirst;            /* Current merge state (see above) */

  210310.   Fts5SegIter aSeg[1];            /* Array of segment iterators */

  210311. };

  210312. 

  210313. 

  210314. /*

  210315. ** An instance of the following type is used to iterate through the contents

  210316. ** of a doclist-index record.

  210317. **

  210318. ** pData:

  210319. **   Record containing the doclist-index data.

  210320. **

  210321. ** bEof:

  210322. **   Set to true once iterator has reached EOF.

  210323. **

  210324. ** iOff:

  210325. **   Set to the current offset within record pData.

  210326. */

  210327. struct Fts5DlidxLvl {

  210328.   Fts5Data *pData;              /* Data for current page of this level */

  210329.   int iOff;                     /* Current offset into pData */

  210330.   int bEof;                     /* At EOF already */

  210331.   int iFirstOff;                /* Used by reverse iterators */

  210332. 

  210333.   /* Output variables */

  210334.   int iLeafPgno;                /* Page number of current leaf page */

  210335.   i64 iRowid;                   /* First rowid on leaf iLeafPgno */

  210336. };

  210337. struct Fts5DlidxIter {

  210338.   int nLvl;

  210339.   int iSegid;

  210340.   Fts5DlidxLvl aLvl[1];

  210341. };

  210342. 

  210343. static void fts5PutU16(u8 *aOut, u16 iVal){

  210344.   aOut[0] = (iVal>>8);

  210345.   aOut[1] = (iVal&0xFF);

  210346. }

  210347. 

  210348. static u16 fts5GetU16(const u8 *aIn){

  210349.   return ((u16)aIn[0] << 8) + aIn[1];

  210350. } 

  210351. 

  210352. /*

  210353. ** Allocate and return a buffer at least nByte bytes in size.

  210354. **

  210355. ** If an OOM error is encountered, return NULL and set the error code in

  210356. ** the Fts5Index handle passed as the first argument.

  210357. */

  210358. static void *fts5IdxMalloc(Fts5Index *p, sqlite3_int64 nByte){

  210359.   return sqlite3Fts5MallocZero(&p->rc, nByte);

  210360. }

  210361. 

  210362. /*

  210363. ** Compare the contents of the pLeft buffer with the pRight/nRight blob.

  210364. **

  210365. ** Return -ve if pLeft is smaller than pRight, 0 if they are equal or

  210366. ** +ve if pRight is smaller than pLeft. In other words:

  210367. **

  210368. **     res = *pLeft - *pRight

  210369. */

  210370. #ifdef SQLITE_DEBUG

  210371. static int fts5BufferCompareBlob(

  210372.   Fts5Buffer *pLeft,              /* Left hand side of comparison */

  210373.   const u8 *pRight, int nRight    /* Right hand side of comparison */

  210374. ){

  210375.   int nCmp = MIN(pLeft->n, nRight);

  210376.   int res = memcmp(pLeft->p, pRight, nCmp);

  210377.   return (res==0 ? (pLeft->n - nRight) : res);

  210378. }

  210379. #endif

  210380. 

  210381. /*

  210382. ** Compare the contents of the two buffers using memcmp(). If one buffer

  210383. ** is a prefix of the other, it is considered the lesser.

  210384. **

  210385. ** Return -ve if pLeft is smaller than pRight, 0 if they are equal or

  210386. ** +ve if pRight is smaller than pLeft. In other words:

  210387. **

  210388. **     res = *pLeft - *pRight

  210389. */

  210390. static int fts5BufferCompare(Fts5Buffer *pLeft, Fts5Buffer *pRight){

  210391.   int nCmp = MIN(pLeft->n, pRight->n);

  210392.   int res = fts5Memcmp(pLeft->p, pRight->p, nCmp);

  210393.   return (res==0 ? (pLeft->n - pRight->n) : res);

  210394. }

  210395. 

  210396. static int fts5LeafFirstTermOff(Fts5Data *pLeaf){

  210397.   int ret;

  210398.   fts5GetVarint32(&pLeaf->p[pLeaf->szLeaf], ret);

  210399.   return ret;

  210400. }

  210401. 

  210402. /*

  210403. ** Close the read-only blob handle, if it is open.

  210404. */

  210405. static void fts5CloseReader(Fts5Index *p){

  210406.   if( p->pReader ){

  210407.     sqlite3_blob *pReader = p->pReader;

  210408.     p->pReader = 0;

  210409.     sqlite3_blob_close(pReader);

  210410.   }

  210411. }

  210412. 

  210413. /*

  210414. ** Retrieve a record from the %_data table.

  210415. **

  210416. ** If an error occurs, NULL is returned and an error left in the 

  210417. ** Fts5Index object.

  210418. */

  210419. static Fts5Data *fts5DataRead(Fts5Index *p, i64 iRowid){

  210420.   Fts5Data *pRet = 0;

  210421.   if( p->rc==SQLITE_OK ){

  210422.     int rc = SQLITE_OK;

  210423. 

  210424.     if( p->pReader ){

  210425.       /* This call may return SQLITE_ABORT if there has been a savepoint

  210426.       ** rollback since it was last used. In this case a new blob handle

  210427.       ** is required.  */

  210428.       sqlite3_blob *pBlob = p->pReader;

  210429.       p->pReader = 0;

  210430.       rc = sqlite3_blob_reopen(pBlob, iRowid);

  210431.       assert( p->pReader==0 );

  210432.       p->pReader = pBlob;

  210433.       if( rc!=SQLITE_OK ){

  210434.         fts5CloseReader(p);

  210435.       }

  210436.       if( rc==SQLITE_ABORT ) rc = SQLITE_OK;

  210437.     }

  210438. 

  210439.     /* If the blob handle is not open at this point, open it and seek 

  210440.     ** to the requested entry.  */

  210441.     if( p->pReader==0 && rc==SQLITE_OK ){

  210442.       Fts5Config *pConfig = p->pConfig;

  210443.       rc = sqlite3_blob_open(pConfig->db, 

  210444.           pConfig->zDb, p->zDataTbl, "block", iRowid, 0, &p->pReader

  210445.       );

  210446.     }

  210447. 

  210448.     /* If either of the sqlite3_blob_open() or sqlite3_blob_reopen() calls

  210449.     ** above returned SQLITE_ERROR, return SQLITE_CORRUPT_VTAB instead.

  210450.     ** All the reasons those functions might return SQLITE_ERROR - missing

  210451.     ** table, missing row, non-blob/text in block column - indicate 

  210452.     ** backing store corruption.  */

  210453.     if( rc==SQLITE_ERROR ) rc = FTS5_CORRUPT;

  210454. 

  210455.     if( rc==SQLITE_OK ){

  210456.       u8 *aOut = 0;               /* Read blob data into this buffer */

  210457.       int nByte = sqlite3_blob_bytes(p->pReader);

  210458.       sqlite3_int64 nAlloc = sizeof(Fts5Data) + nByte + FTS5_DATA_PADDING;

  210459.       pRet = (Fts5Data*)sqlite3_malloc64(nAlloc);

  210460.       if( pRet ){

  210461.         pRet->nn = nByte;

  210462.         aOut = pRet->p = (u8*)&pRet[1];

  210463.       }else{

  210464.         rc = SQLITE_NOMEM;

  210465.       }

  210466. 

  210467.       if( rc==SQLITE_OK ){

  210468.         rc = sqlite3_blob_read(p->pReader, aOut, nByte, 0);

  210469.       }

  210470.       if( rc!=SQLITE_OK ){

  210471.         sqlite3_free(pRet);

  210472.         pRet = 0;

  210473.       }else{

  210474.         /* TODO1: Fix this */

  210475.         pRet->p[nByte] = 0x00;

  210476.         pRet->szLeaf = fts5GetU16(&pRet->p[2]);

  210477.       }

  210478.     }

  210479.     p->rc = rc;

  210480.     p->nRead++;

  210481.   }

  210482. 

  210483.   assert( (pRet==0)==(p->rc!=SQLITE_OK) );

  210484.   return pRet;

  210485. }

  210486. 

  210487. /*

  210488. ** Release a reference to data record returned by an earlier call to

  210489. ** fts5DataRead().

  210490. */

  210491. static void fts5DataRelease(Fts5Data *pData){

  210492.   sqlite3_free(pData);

  210493. }

  210494. 

  210495. static Fts5Data *fts5LeafRead(Fts5Index *p, i64 iRowid){

  210496.   Fts5Data *pRet = fts5DataRead(p, iRowid);

  210497.   if( pRet ){

  210498.     if( pRet->szLeaf>pRet->nn ){

  210499.       p->rc = FTS5_CORRUPT;

  210500.       fts5DataRelease(pRet);

  210501.       pRet = 0;

  210502.     }

  210503.   }

  210504.   return pRet;

  210505. }

  210506. 

  210507. static int fts5IndexPrepareStmt(

  210508.   Fts5Index *p,

  210509.   sqlite3_stmt **ppStmt,

  210510.   char *zSql

  210511. ){

  210512.   if( p->rc==SQLITE_OK ){

  210513.     if( zSql ){

  210514.       p->rc = sqlite3_prepare_v3(p->pConfig->db, zSql, -1,

  210515.           SQLITE_PREPARE_PERSISTENT|SQLITE_PREPARE_NO_VTAB,

  210516.           ppStmt, 0);

  210517.     }else{

  210518.       p->rc = SQLITE_NOMEM;

  210519.     }

  210520.   }

  210521.   sqlite3_free(zSql);

  210522.   return p->rc;

  210523. }

  210524. 

  210525. 

  210526. /*

  210527. ** INSERT OR REPLACE a record into the %_data table.

  210528. */

  210529. static void fts5DataWrite(Fts5Index *p, i64 iRowid, const u8 *pData, int nData){

  210530.   if( p->rc!=SQLITE_OK ) return;

  210531. 

  210532.   if( p->pWriter==0 ){

  210533.     Fts5Config *pConfig = p->pConfig;

  210534.     fts5IndexPrepareStmt(p, &p->pWriter, sqlite3_mprintf(

  210535.           "REPLACE INTO '%q'.'%q_data'(id, block) VALUES(?,?)", 

  210536.           pConfig->zDb, pConfig->zName

  210537.     ));

  210538.     if( p->rc ) return;

  210539.   }

  210540. 

  210541.   sqlite3_bind_int64(p->pWriter, 1, iRowid);

  210542.   sqlite3_bind_blob(p->pWriter, 2, pData, nData, SQLITE_STATIC);

  210543.   sqlite3_step(p->pWriter);

  210544.   p->rc = sqlite3_reset(p->pWriter);

  210545.   sqlite3_bind_null(p->pWriter, 2);

  210546. }

  210547. 

  210548. /*

  210549. ** Execute the following SQL:

  210550. **

  210551. **     DELETE FROM %_data WHERE id BETWEEN $iFirst AND $iLast

  210552. */

  210553. static void fts5DataDelete(Fts5Index *p, i64 iFirst, i64 iLast){

  210554.   if( p->rc!=SQLITE_OK ) return;

  210555. 

  210556.   if( p->pDeleter==0 ){

  210557.     Fts5Config *pConfig = p->pConfig;

  210558.     char *zSql = sqlite3_mprintf(

  210559.         "DELETE FROM '%q'.'%q_data' WHERE id>=? AND id<=?", 

  210560.           pConfig->zDb, pConfig->zName

  210561.     );

  210562.     if( fts5IndexPrepareStmt(p, &p->pDeleter, zSql) ) return;

  210563.   }

  210564. 

  210565.   sqlite3_bind_int64(p->pDeleter, 1, iFirst);

  210566.   sqlite3_bind_int64(p->pDeleter, 2, iLast);

  210567.   sqlite3_step(p->pDeleter);

  210568.   p->rc = sqlite3_reset(p->pDeleter);

  210569. }

  210570. 

  210571. /*

  210572. ** Remove all records associated with segment iSegid.

  210573. */

  210574. static void fts5DataRemoveSegment(Fts5Index *p, int iSegid){

  210575.   i64 iFirst = FTS5_SEGMENT_ROWID(iSegid, 0);

  210576.   i64 iLast = FTS5_SEGMENT_ROWID(iSegid+1, 0)-1;

  210577.   fts5DataDelete(p, iFirst, iLast);

  210578.   if( p->pIdxDeleter==0 ){

  210579.     Fts5Config *pConfig = p->pConfig;

  210580.     fts5IndexPrepareStmt(p, &p->pIdxDeleter, sqlite3_mprintf(

  210581.           "DELETE FROM '%q'.'%q_idx' WHERE segid=?",

  210582.           pConfig->zDb, pConfig->zName

  210583.     ));

  210584.   }

  210585.   if( p->rc==SQLITE_OK ){

  210586.     sqlite3_bind_int(p->pIdxDeleter, 1, iSegid);

  210587.     sqlite3_step(p->pIdxDeleter);

  210588.     p->rc = sqlite3_reset(p->pIdxDeleter);

  210589.   }

  210590. }

  210591. 

  210592. /*

  210593. ** Release a reference to an Fts5Structure object returned by an earlier 

  210594. ** call to fts5StructureRead() or fts5StructureDecode().

  210595. */

  210596. static void fts5StructureRelease(Fts5Structure *pStruct){

  210597.   if( pStruct && 0>=(--pStruct->nRef) ){

  210598.     int i;

  210599.     assert( pStruct->nRef==0 );

  210600.     for(i=0; i<pStruct->nLevel; i++){

  210601.       sqlite3_free(pStruct->aLevel[i].aSeg);

  210602.     }

  210603.     sqlite3_free(pStruct);

  210604.   }

  210605. }

  210606. 

  210607. static void fts5StructureRef(Fts5Structure *pStruct){

  210608.   pStruct->nRef++;

  210609. }

  210610. 

  210611. /*

  210612. ** Deserialize and return the structure record currently stored in serialized

  210613. ** form within buffer pData/nData.

  210614. **

  210615. ** The Fts5Structure.aLevel[] and each Fts5StructureLevel.aSeg[] array

  210616. ** are over-allocated by one slot. This allows the structure contents

  210617. ** to be more easily edited.

  210618. **

  210619. ** If an error occurs, *ppOut is set to NULL and an SQLite error code

  210620. ** returned. Otherwise, *ppOut is set to point to the new object and

  210621. ** SQLITE_OK returned.

  210622. */

  210623. static int fts5StructureDecode(

  210624.   const u8 *pData,                /* Buffer containing serialized structure */

  210625.   int nData,                      /* Size of buffer pData in bytes */

  210626.   int *piCookie,                  /* Configuration cookie value */

  210627.   Fts5Structure **ppOut           /* OUT: Deserialized object */

  210628. ){

  210629.   int rc = SQLITE_OK;

  210630.   int i = 0;

  210631.   int iLvl;

  210632.   int nLevel = 0;

  210633.   int nSegment = 0;

  210634.   sqlite3_int64 nByte;            /* Bytes of space to allocate at pRet */

  210635.   Fts5Structure *pRet = 0;        /* Structure object to return */

  210636. 

  210637.   /* Grab the cookie value */

  210638.   if( piCookie ) *piCookie = sqlite3Fts5Get32(pData);

  210639.   i = 4;

  210640. 

  210641.   /* Read the total number of levels and segments from the start of the

  210642.   ** structure record.  */

  210643.   i += fts5GetVarint32(&pData[i], nLevel);

  210644.   i += fts5GetVarint32(&pData[i], nSegment);

  210645.   if( nLevel>FTS5_MAX_SEGMENT   || nLevel<0

  210646.    || nSegment>FTS5_MAX_SEGMENT || nSegment<0

  210647.   ){

  210648.     return FTS5_CORRUPT;

  210649.   }

  210650.   nByte = (

  210651.       sizeof(Fts5Structure) +                    /* Main structure */

  210652.       sizeof(Fts5StructureLevel) * (nLevel-1)    /* aLevel[] array */

  210653.   );

  210654.   pRet = (Fts5Structure*)sqlite3Fts5MallocZero(&rc, nByte);

  210655. 

  210656.   if( pRet ){

  210657.     pRet->nRef = 1;

  210658.     pRet->nLevel = nLevel;

  210659.     pRet->nSegment = nSegment;

  210660.     i += sqlite3Fts5GetVarint(&pData[i], &pRet->nWriteCounter);

  210661. 

  210662.     for(iLvl=0; rc==SQLITE_OK && iLvl<nLevel; iLvl++){

  210663.       Fts5StructureLevel *pLvl = &pRet->aLevel[iLvl];

  210664.       int nTotal = 0;

  210665.       int iSeg;

  210666. 

  210667.       if( i>=nData ){

  210668.         rc = FTS5_CORRUPT;

  210669.       }else{

  210670.         i += fts5GetVarint32(&pData[i], pLvl->nMerge);

  210671.         i += fts5GetVarint32(&pData[i], nTotal);

  210672.         if( nTotal<pLvl->nMerge ) rc = FTS5_CORRUPT;

  210673.         pLvl->aSeg = (Fts5StructureSegment*)sqlite3Fts5MallocZero(&rc, 

  210674.             nTotal * sizeof(Fts5StructureSegment)

  210675.         );

  210676.         nSegment -= nTotal;

  210677.       }

  210678. 

  210679.       if( rc==SQLITE_OK ){

  210680.         pLvl->nSeg = nTotal;

  210681.         for(iSeg=0; iSeg<nTotal; iSeg++){

  210682.           Fts5StructureSegment *pSeg = &pLvl->aSeg[iSeg];

  210683.           if( i>=nData ){

  210684.             rc = FTS5_CORRUPT;

  210685.             break;

  210686.           }

  210687.           i += fts5GetVarint32(&pData[i], pSeg->iSegid);

  210688.           i += fts5GetVarint32(&pData[i], pSeg->pgnoFirst);

  210689.           i += fts5GetVarint32(&pData[i], pSeg->pgnoLast);

  210690.           if( pSeg->pgnoLast<pSeg->pgnoFirst ){

  210691.             rc = FTS5_CORRUPT;

  210692.             break;

  210693.           }

  210694.         }

  210695.         if( iLvl>0 && pLvl[-1].nMerge && nTotal==0 ) rc = FTS5_CORRUPT;

  210696.         if( iLvl==nLevel-1 && pLvl->nMerge ) rc = FTS5_CORRUPT;

  210697.       }

  210698.     }

  210699.     if( nSegment!=0 && rc==SQLITE_OK ) rc = FTS5_CORRUPT;

  210700. 

  210701.     if( rc!=SQLITE_OK ){

  210702.       fts5StructureRelease(pRet);

  210703.       pRet = 0;

  210704.     }

  210705.   }

  210706. 

  210707.   *ppOut = pRet;

  210708.   return rc;

  210709. }

  210710. 

  210711. /*

  210712. **

  210713. */

  210714. static void fts5StructureAddLevel(int *pRc, Fts5Structure **ppStruct){

  210715.   if( *pRc==SQLITE_OK ){

  210716.     Fts5Structure *pStruct = *ppStruct;

  210717.     int nLevel = pStruct->nLevel;

  210718.     sqlite3_int64 nByte = (

  210719.         sizeof(Fts5Structure) +                  /* Main structure */

  210720.         sizeof(Fts5StructureLevel) * (nLevel+1)  /* aLevel[] array */

  210721.     );

  210722. 

  210723.     pStruct = sqlite3_realloc64(pStruct, nByte);

  210724.     if( pStruct ){

  210725.       memset(&pStruct->aLevel[nLevel], 0, sizeof(Fts5StructureLevel));

  210726.       pStruct->nLevel++;

  210727.       *ppStruct = pStruct;

  210728.     }else{

  210729.       *pRc = SQLITE_NOMEM;

  210730.     }

  210731.   }

  210732. }

  210733. 

  210734. /*

  210735. ** Extend level iLvl so that there is room for at least nExtra more

  210736. ** segments.

  210737. */

  210738. static void fts5StructureExtendLevel(

  210739.   int *pRc, 

  210740.   Fts5Structure *pStruct, 

  210741.   int iLvl, 

  210742.   int nExtra, 

  210743.   int bInsert

  210744. ){

  210745.   if( *pRc==SQLITE_OK ){

  210746.     Fts5StructureLevel *pLvl = &pStruct->aLevel[iLvl];

  210747.     Fts5StructureSegment *aNew;

  210748.     sqlite3_int64 nByte;

  210749. 

  210750.     nByte = (pLvl->nSeg + nExtra) * sizeof(Fts5StructureSegment);

  210751.     aNew = sqlite3_realloc64(pLvl->aSeg, nByte);

  210752.     if( aNew ){

  210753.       if( bInsert==0 ){

  210754.         memset(&aNew[pLvl->nSeg], 0, sizeof(Fts5StructureSegment) * nExtra);

  210755.       }else{

  210756.         int nMove = pLvl->nSeg * sizeof(Fts5StructureSegment);

  210757.         memmove(&aNew[nExtra], aNew, nMove);

  210758.         memset(aNew, 0, sizeof(Fts5StructureSegment) * nExtra);

  210759.       }

  210760.       pLvl->aSeg = aNew;

  210761.     }else{

  210762.       *pRc = SQLITE_NOMEM;

  210763.     }

  210764.   }

  210765. }

  210766. 

  210767. static Fts5Structure *fts5StructureReadUncached(Fts5Index *p){

  210768.   Fts5Structure *pRet = 0;

  210769.   Fts5Config *pConfig = p->pConfig;

  210770.   int iCookie;                    /* Configuration cookie */

  210771.   Fts5Data *pData;

  210772. 

  210773.   pData = fts5DataRead(p, FTS5_STRUCTURE_ROWID);

  210774.   if( p->rc==SQLITE_OK ){

  210775.     /* TODO: Do we need this if the leaf-index is appended? Probably... */

  210776.     memset(&pData->p[pData->nn], 0, FTS5_DATA_PADDING);

  210777.     p->rc = fts5StructureDecode(pData->p, pData->nn, &iCookie, &pRet);

  210778.     if( p->rc==SQLITE_OK && (pConfig->pgsz==0 || pConfig->iCookie!=iCookie) ){

  210779.       p->rc = sqlite3Fts5ConfigLoad(pConfig, iCookie);

  210780.     }

  210781.     fts5DataRelease(pData);

  210782.     if( p->rc!=SQLITE_OK ){

  210783.       fts5StructureRelease(pRet);

  210784.       pRet = 0;

  210785.     }

  210786.   }

  210787. 

  210788.   return pRet;

  210789. }

  210790. 

  210791. static i64 fts5IndexDataVersion(Fts5Index *p){

  210792.   i64 iVersion = 0;

  210793. 

  210794.   if( p->rc==SQLITE_OK ){

  210795.     if( p->pDataVersion==0 ){

  210796.       p->rc = fts5IndexPrepareStmt(p, &p->pDataVersion, 

  210797.           sqlite3_mprintf("PRAGMA %Q.data_version", p->pConfig->zDb)

  210798.           );

  210799.       if( p->rc ) return 0;

  210800.     }

  210801. 

  210802.     if( SQLITE_ROW==sqlite3_step(p->pDataVersion) ){

  210803.       iVersion = sqlite3_column_int64(p->pDataVersion, 0);

  210804.     }

  210805.     p->rc = sqlite3_reset(p->pDataVersion);

  210806.   }

  210807. 

  210808.   return iVersion;

  210809. }

  210810. 

  210811. /*

  210812. ** Read, deserialize and return the structure record.

  210813. **

  210814. ** The Fts5Structure.aLevel[] and each Fts5StructureLevel.aSeg[] array

  210815. ** are over-allocated as described for function fts5StructureDecode() 

  210816. ** above.

  210817. **

  210818. ** If an error occurs, NULL is returned and an error code left in the

  210819. ** Fts5Index handle. If an error has already occurred when this function

  210820. ** is called, it is a no-op.

  210821. */

  210822. static Fts5Structure *fts5StructureRead(Fts5Index *p){

  210823. 

  210824.   if( p->pStruct==0 ){

  210825.     p->iStructVersion = fts5IndexDataVersion(p);

  210826.     if( p->rc==SQLITE_OK ){

  210827.       p->pStruct = fts5StructureReadUncached(p);

  210828.     }

  210829.   }

  210830. 

  210831. #if 0

  210832.   else{

  210833.     Fts5Structure *pTest = fts5StructureReadUncached(p);

  210834.     if( pTest ){

  210835.       int i, j;

  210836.       assert_nc( p->pStruct->nSegment==pTest->nSegment );

  210837.       assert_nc( p->pStruct->nLevel==pTest->nLevel );

  210838.       for(i=0; i<pTest->nLevel; i++){

  210839.         assert_nc( p->pStruct->aLevel[i].nMerge==pTest->aLevel[i].nMerge );

  210840.         assert_nc( p->pStruct->aLevel[i].nSeg==pTest->aLevel[i].nSeg );

  210841.         for(j=0; j<pTest->aLevel[i].nSeg; j++){

  210842.           Fts5StructureSegment *p1 = &pTest->aLevel[i].aSeg[j];

  210843.           Fts5StructureSegment *p2 = &p->pStruct->aLevel[i].aSeg[j];

  210844.           assert_nc( p1->iSegid==p2->iSegid );

  210845.           assert_nc( p1->pgnoFirst==p2->pgnoFirst );

  210846.           assert_nc( p1->pgnoLast==p2->pgnoLast );

  210847.         }

  210848.       }

  210849.       fts5StructureRelease(pTest);

  210850.     }

  210851.   }

  210852. #endif

  210853. 

  210854.   if( p->rc!=SQLITE_OK ) return 0;

  210855.   assert( p->iStructVersion!=0 );

  210856.   assert( p->pStruct!=0 );

  210857.   fts5StructureRef(p->pStruct);

  210858.   return p->pStruct;

  210859. }

  210860. 

  210861. static void fts5StructureInvalidate(Fts5Index *p){

  210862.   if( p->pStruct ){

  210863.     fts5StructureRelease(p->pStruct);

  210864.     p->pStruct = 0;

  210865.   }

  210866. }

  210867. 

  210868. /*

  210869. ** Return the total number of segments in index structure pStruct. This

  210870. ** function is only ever used as part of assert() conditions.

  210871. */

  210872. #ifdef SQLITE_DEBUG

  210873. static int fts5StructureCountSegments(Fts5Structure *pStruct){

  210874.   int nSegment = 0;               /* Total number of segments */

  210875.   if( pStruct ){

  210876.     int iLvl;                     /* Used to iterate through levels */

  210877.     for(iLvl=0; iLvl<pStruct->nLevel; iLvl++){

  210878.       nSegment += pStruct->aLevel[iLvl].nSeg;

  210879.     }

  210880.   }

  210881. 

  210882.   return nSegment;

  210883. }

  210884. #endif

  210885. 

  210886. #define fts5BufferSafeAppendBlob(pBuf, pBlob, nBlob) {     \

  210887.   assert( (pBuf)->nSpace>=((pBuf)->n+nBlob) );             \

  210888.   memcpy(&(pBuf)->p[(pBuf)->n], pBlob, nBlob);             \

  210889.   (pBuf)->n += nBlob;                                      \

  210890. }

  210891. 

  210892. #define fts5BufferSafeAppendVarint(pBuf, iVal) {                \

  210893.   (pBuf)->n += sqlite3Fts5PutVarint(&(pBuf)->p[(pBuf)->n], (iVal));  \

  210894.   assert( (pBuf)->nSpace>=(pBuf)->n );                          \

  210895. }

  210896. 

  210897. 

  210898. /*

  210899. ** Serialize and store the "structure" record.

  210900. **

  210901. ** If an error occurs, leave an error code in the Fts5Index object. If an

  210902. ** error has already occurred, this function is a no-op.

  210903. */

  210904. static void fts5StructureWrite(Fts5Index *p, Fts5Structure *pStruct){

  210905.   if( p->rc==SQLITE_OK ){

  210906.     Fts5Buffer buf;               /* Buffer to serialize record into */

  210907.     int iLvl;                     /* Used to iterate through levels */

  210908.     int iCookie;                  /* Cookie value to store */

  210909. 

  210910.     assert( pStruct->nSegment==fts5StructureCountSegments(pStruct) );

  210911.     memset(&buf, 0, sizeof(Fts5Buffer));

  210912. 

  210913.     /* Append the current configuration cookie */

  210914.     iCookie = p->pConfig->iCookie;

  210915.     if( iCookie<0 ) iCookie = 0;

  210916. 

  210917.     if( 0==sqlite3Fts5BufferSize(&p->rc, &buf, 4+9+9+9) ){

  210918.       sqlite3Fts5Put32(buf.p, iCookie);

  210919.       buf.n = 4;

  210920.       fts5BufferSafeAppendVarint(&buf, pStruct->nLevel);

  210921.       fts5BufferSafeAppendVarint(&buf, pStruct->nSegment);

  210922.       fts5BufferSafeAppendVarint(&buf, (i64)pStruct->nWriteCounter);

  210923.     }

  210924. 

  210925.     for(iLvl=0; iLvl<pStruct->nLevel; iLvl++){

  210926.       int iSeg;                     /* Used to iterate through segments */

  210927.       Fts5StructureLevel *pLvl = &pStruct->aLevel[iLvl];

  210928.       fts5BufferAppendVarint(&p->rc, &buf, pLvl->nMerge);

  210929.       fts5BufferAppendVarint(&p->rc, &buf, pLvl->nSeg);

  210930.       assert( pLvl->nMerge<=pLvl->nSeg );

  210931. 

  210932.       for(iSeg=0; iSeg<pLvl->nSeg; iSeg++){

  210933.         fts5BufferAppendVarint(&p->rc, &buf, pLvl->aSeg[iSeg].iSegid);

  210934.         fts5BufferAppendVarint(&p->rc, &buf, pLvl->aSeg[iSeg].pgnoFirst);

  210935.         fts5BufferAppendVarint(&p->rc, &buf, pLvl->aSeg[iSeg].pgnoLast);

  210936.       }

  210937.     }

  210938. 

  210939.     fts5DataWrite(p, FTS5_STRUCTURE_ROWID, buf.p, buf.n);

  210940.     fts5BufferFree(&buf);

  210941.   }

  210942. }

  210943. 

  210944. #if 0

  210945. static void fts5DebugStructure(int*,Fts5Buffer*,Fts5Structure*);

  210946. static void fts5PrintStructure(const char *zCaption, Fts5Structure *pStruct){

  210947.   int rc = SQLITE_OK;

  210948.   Fts5Buffer buf;

  210949.   memset(&buf, 0, sizeof(buf));

  210950.   fts5DebugStructure(&rc, &buf, pStruct);

  210951.   fprintf(stdout, "%s: %s\n", zCaption, buf.p);

  210952.   fflush(stdout);

  210953.   fts5BufferFree(&buf);

  210954. }

  210955. #else

  210956. # define fts5PrintStructure(x,y)

  210957. #endif

  210958. 

  210959. static int fts5SegmentSize(Fts5StructureSegment *pSeg){

  210960.   return 1 + pSeg->pgnoLast - pSeg->pgnoFirst;

  210961. }

  210962. 

  210963. /*

  210964. ** Return a copy of index structure pStruct. Except, promote as many 

  210965. ** segments as possible to level iPromote. If an OOM occurs, NULL is 

  210966. ** returned.

  210967. */

  210968. static void fts5StructurePromoteTo(

  210969.   Fts5Index *p,

  210970.   int iPromote,

  210971.   int szPromote,

  210972.   Fts5Structure *pStruct

  210973. ){

  210974.   int il, is;

  210975.   Fts5StructureLevel *pOut = &pStruct->aLevel[iPromote];

  210976. 

  210977.   if( pOut->nMerge==0 ){

  210978.     for(il=iPromote+1; il<pStruct->nLevel; il++){

  210979.       Fts5StructureLevel *pLvl = &pStruct->aLevel[il];

  210980.       if( pLvl->nMerge ) return;

  210981.       for(is=pLvl->nSeg-1; is>=0; is--){

  210982.         int sz = fts5SegmentSize(&pLvl->aSeg[is]);

  210983.         if( sz>szPromote ) return;

  210984.         fts5StructureExtendLevel(&p->rc, pStruct, iPromote, 1, 1);

  210985.         if( p->rc ) return;

  210986.         memcpy(pOut->aSeg, &pLvl->aSeg[is], sizeof(Fts5StructureSegment));

  210987.         pOut->nSeg++;

  210988.         pLvl->nSeg--;

  210989.       }

  210990.     }

  210991.   }

  210992. }

  210993. 

  210994. /*

  210995. ** A new segment has just been written to level iLvl of index structure

  210996. ** pStruct. This function determines if any segments should be promoted

  210997. ** as a result. Segments are promoted in two scenarios:

  210998. **

  210999. **   a) If the segment just written is smaller than one or more segments

  211000. **      within the previous populated level, it is promoted to the previous

  211001. **      populated level.

  211002. **

  211003. **   b) If the segment just written is larger than the newest segment on

  211004. **      the next populated level, then that segment, and any other adjacent

  211005. **      segments that are also smaller than the one just written, are 

  211006. **      promoted. 

  211007. **

  211008. ** If one or more segments are promoted, the structure object is updated

  211009. ** to reflect this.

  211010. */

  211011. static void fts5StructurePromote(

  211012.   Fts5Index *p,                   /* FTS5 backend object */

  211013.   int iLvl,                       /* Index level just updated */

  211014.   Fts5Structure *pStruct          /* Index structure */

  211015. ){

  211016.   if( p->rc==SQLITE_OK ){

  211017.     int iTst;

  211018.     int iPromote = -1;

  211019.     int szPromote = 0;            /* Promote anything this size or smaller */

  211020.     Fts5StructureSegment *pSeg;   /* Segment just written */

  211021.     int szSeg;                    /* Size of segment just written */

  211022.     int nSeg = pStruct->aLevel[iLvl].nSeg;

  211023. 

  211024.     if( nSeg==0 ) return;

  211025.     pSeg = &pStruct->aLevel[iLvl].aSeg[pStruct->aLevel[iLvl].nSeg-1];

  211026.     szSeg = (1 + pSeg->pgnoLast - pSeg->pgnoFirst);

  211027. 

  211028.     /* Check for condition (a) */

  211029.     for(iTst=iLvl-1; iTst>=0 && pStruct->aLevel[iTst].nSeg==0; iTst--);

  211030.     if( iTst>=0 ){

  211031.       int i;

  211032.       int szMax = 0;

  211033.       Fts5StructureLevel *pTst = &pStruct->aLevel[iTst];

  211034.       assert( pTst->nMerge==0 );

  211035.       for(i=0; i<pTst->nSeg; i++){

  211036.         int sz = pTst->aSeg[i].pgnoLast - pTst->aSeg[i].pgnoFirst + 1;

  211037.         if( sz>szMax ) szMax = sz;

  211038.       }

  211039.       if( szMax>=szSeg ){

  211040.         /* Condition (a) is true. Promote the newest segment on level 

  211041.         ** iLvl to level iTst.  */

  211042.         iPromote = iTst;

  211043.         szPromote = szMax;

  211044.       }

  211045.     }

  211046. 

  211047.     /* If condition (a) is not met, assume (b) is true. StructurePromoteTo()

  211048.     ** is a no-op if it is not.  */

  211049.     if( iPromote<0 ){

  211050.       iPromote = iLvl;

  211051.       szPromote = szSeg;

  211052.     }

  211053.     fts5StructurePromoteTo(p, iPromote, szPromote, pStruct);

  211054.   }

  211055. }

  211056. 

  211057. 

  211058. /*

  211059. ** Advance the iterator passed as the only argument. If the end of the 

  211060. ** doclist-index page is reached, return non-zero.

  211061. */

  211062. static int fts5DlidxLvlNext(Fts5DlidxLvl *pLvl){

  211063.   Fts5Data *pData = pLvl->pData;

  211064. 

  211065.   if( pLvl->iOff==0 ){

  211066.     assert( pLvl->bEof==0 );

  211067.     pLvl->iOff = 1;

  211068.     pLvl->iOff += fts5GetVarint32(&pData->p[1], pLvl->iLeafPgno);

  211069.     pLvl->iOff += fts5GetVarint(&pData->p[pLvl->iOff], (u64*)&pLvl->iRowid);

  211070.     pLvl->iFirstOff = pLvl->iOff;

  211071.   }else{

  211072.     int iOff;

  211073.     for(iOff=pLvl->iOff; iOff<pData->nn; iOff++){

  211074.       if( pData->p[iOff] ) break; 

  211075.     }

  211076. 

  211077.     if( iOff<pData->nn ){

  211078.       i64 iVal;

  211079.       pLvl->iLeafPgno += (iOff - pLvl->iOff) + 1;

  211080.       iOff += fts5GetVarint(&pData->p[iOff], (u64*)&iVal);

  211081.       pLvl->iRowid += iVal;

  211082.       pLvl->iOff = iOff;

  211083.     }else{

  211084.       pLvl->bEof = 1;

  211085.     }

  211086.   }

  211087. 

  211088.   return pLvl->bEof;

  211089. }

  211090. 

  211091. /*

  211092. ** Advance the iterator passed as the only argument.

  211093. */

  211094. static int fts5DlidxIterNextR(Fts5Index *p, Fts5DlidxIter *pIter, int iLvl){

  211095.   Fts5DlidxLvl *pLvl = &pIter->aLvl[iLvl];

  211096. 

  211097.   assert( iLvl<pIter->nLvl );

  211098.   if( fts5DlidxLvlNext(pLvl) ){

  211099.     if( (iLvl+1) < pIter->nLvl ){

  211100.       fts5DlidxIterNextR(p, pIter, iLvl+1);

  211101.       if( pLvl[1].bEof==0 ){

  211102.         fts5DataRelease(pLvl->pData);

  211103.         memset(pLvl, 0, sizeof(Fts5DlidxLvl));

  211104.         pLvl->pData = fts5DataRead(p, 

  211105.             FTS5_DLIDX_ROWID(pIter->iSegid, iLvl, pLvl[1].iLeafPgno)

  211106.         );

  211107.         if( pLvl->pData ) fts5DlidxLvlNext(pLvl);

  211108.       }

  211109.     }

  211110.   }

  211111. 

  211112.   return pIter->aLvl[0].bEof;

  211113. }

  211114. static int fts5DlidxIterNext(Fts5Index *p, Fts5DlidxIter *pIter){

  211115.   return fts5DlidxIterNextR(p, pIter, 0);

  211116. }

  211117. 

  211118. /*

  211119. ** The iterator passed as the first argument has the following fields set

  211120. ** as follows. This function sets up the rest of the iterator so that it

  211121. ** points to the first rowid in the doclist-index.

  211122. **

  211123. **   pData:

  211124. **     pointer to doclist-index record, 

  211125. **

  211126. ** When this function is called pIter->iLeafPgno is the page number the

  211127. ** doclist is associated with (the one featuring the term).

  211128. */

  211129. static int fts5DlidxIterFirst(Fts5DlidxIter *pIter){

  211130.   int i;

  211131.   for(i=0; i<pIter->nLvl; i++){

  211132.     fts5DlidxLvlNext(&pIter->aLvl[i]);

  211133.   }

  211134.   return pIter->aLvl[0].bEof;

  211135. }

  211136. 

  211137. 

  211138. static int fts5DlidxIterEof(Fts5Index *p, Fts5DlidxIter *pIter){

  211139.   return p->rc!=SQLITE_OK || pIter->aLvl[0].bEof;

  211140. }

  211141. 

  211142. static void fts5DlidxIterLast(Fts5Index *p, Fts5DlidxIter *pIter){

  211143.   int i;

  211144. 

  211145.   /* Advance each level to the last entry on the last page */

  211146.   for(i=pIter->nLvl-1; p->rc==SQLITE_OK && i>=0; i--){

  211147.     Fts5DlidxLvl *pLvl = &pIter->aLvl[i];

  211148.     while( fts5DlidxLvlNext(pLvl)==0 );

  211149.     pLvl->bEof = 0;

  211150. 

  211151.     if( i>0 ){

  211152.       Fts5DlidxLvl *pChild = &pLvl[-1];

  211153.       fts5DataRelease(pChild->pData);

  211154.       memset(pChild, 0, sizeof(Fts5DlidxLvl));

  211155.       pChild->pData = fts5DataRead(p, 

  211156.           FTS5_DLIDX_ROWID(pIter->iSegid, i-1, pLvl->iLeafPgno)

  211157.       );

  211158.     }

  211159.   }

  211160. }

  211161. 

  211162. /*

  211163. ** Move the iterator passed as the only argument to the previous entry.

  211164. */

  211165. static int fts5DlidxLvlPrev(Fts5DlidxLvl *pLvl){

  211166.   int iOff = pLvl->iOff;

  211167. 

  211168.   assert( pLvl->bEof==0 );

  211169.   if( iOff<=pLvl->iFirstOff ){

  211170.     pLvl->bEof = 1;

  211171.   }else{

  211172.     u8 *a = pLvl->pData->p;

  211173.     i64 iVal;

  211174.     int iLimit;

  211175.     int ii;

  211176.     int nZero = 0;

  211177. 

  211178.     /* Currently iOff points to the first byte of a varint. This block 

  211179.     ** decrements iOff until it points to the first byte of the previous 

  211180.     ** varint. Taking care not to read any memory locations that occur

  211181.     ** before the buffer in memory.  */

  211182.     iLimit = (iOff>9 ? iOff-9 : 0);

  211183.     for(iOff--; iOff>iLimit; iOff--){

  211184.       if( (a[iOff-1] & 0x80)==0 ) break;

  211185.     }

  211186. 

  211187.     fts5GetVarint(&a[iOff], (u64*)&iVal);

  211188.     pLvl->iRowid -= iVal;

  211189.     pLvl->iLeafPgno--;

  211190. 

  211191.     /* Skip backwards past any 0x00 varints. */

  211192.     for(ii=iOff-1; ii>=pLvl->iFirstOff && a[ii]==0x00; ii--){

  211193.       nZero++;

  211194.     }

  211195.     if( ii>=pLvl->iFirstOff && (a[ii] & 0x80) ){

  211196.       /* The byte immediately before the last 0x00 byte has the 0x80 bit

  211197.       ** set. So the last 0x00 is only a varint 0 if there are 8 more 0x80

  211198.       ** bytes before a[ii]. */

  211199.       int bZero = 0;              /* True if last 0x00 counts */

  211200.       if( (ii-8)>=pLvl->iFirstOff ){

  211201.         int j;

  211202.         for(j=1; j<=8 && (a[ii-j] & 0x80); j++);

  211203.         bZero = (j>8);

  211204.       }

  211205.       if( bZero==0 ) nZero--;

  211206.     }

  211207.     pLvl->iLeafPgno -= nZero;

  211208.     pLvl->iOff = iOff - nZero;

  211209.   }

  211210. 

  211211.   return pLvl->bEof;

  211212. }

  211213. 

  211214. static int fts5DlidxIterPrevR(Fts5Index *p, Fts5DlidxIter *pIter, int iLvl){

  211215.   Fts5DlidxLvl *pLvl = &pIter->aLvl[iLvl];

  211216. 

  211217.   assert( iLvl<pIter->nLvl );

  211218.   if( fts5DlidxLvlPrev(pLvl) ){

  211219.     if( (iLvl+1) < pIter->nLvl ){

  211220.       fts5DlidxIterPrevR(p, pIter, iLvl+1);

  211221.       if( pLvl[1].bEof==0 ){

  211222.         fts5DataRelease(pLvl->pData);

  211223.         memset(pLvl, 0, sizeof(Fts5DlidxLvl));

  211224.         pLvl->pData = fts5DataRead(p, 

  211225.             FTS5_DLIDX_ROWID(pIter->iSegid, iLvl, pLvl[1].iLeafPgno)

  211226.         );

  211227.         if( pLvl->pData ){

  211228.           while( fts5DlidxLvlNext(pLvl)==0 );

  211229.           pLvl->bEof = 0;

  211230.         }

  211231.       }

  211232.     }

  211233.   }

  211234. 

  211235.   return pIter->aLvl[0].bEof;

  211236. }

  211237. static int fts5DlidxIterPrev(Fts5Index *p, Fts5DlidxIter *pIter){

  211238.   return fts5DlidxIterPrevR(p, pIter, 0);

  211239. }

  211240. 

  211241. /*

  211242. ** Free a doclist-index iterator object allocated by fts5DlidxIterInit().

  211243. */

  211244. static void fts5DlidxIterFree(Fts5DlidxIter *pIter){

  211245.   if( pIter ){

  211246.     int i;

  211247.     for(i=0; i<pIter->nLvl; i++){

  211248.       fts5DataRelease(pIter->aLvl[i].pData);

  211249.     }

  211250.     sqlite3_free(pIter);

  211251.   }

  211252. }

  211253. 

  211254. static Fts5DlidxIter *fts5DlidxIterInit(

  211255.   Fts5Index *p,                   /* Fts5 Backend to iterate within */

  211256.   int bRev,                       /* True for ORDER BY ASC */

  211257.   int iSegid,                     /* Segment id */

  211258.   int iLeafPg                     /* Leaf page number to load dlidx for */

  211259. ){

  211260.   Fts5DlidxIter *pIter = 0;

  211261.   int i;

  211262.   int bDone = 0;

  211263. 

  211264.   for(i=0; p->rc==SQLITE_OK && bDone==0; i++){

  211265.     sqlite3_int64 nByte = sizeof(Fts5DlidxIter) + i * sizeof(Fts5DlidxLvl);

  211266.     Fts5DlidxIter *pNew;

  211267. 

  211268.     pNew = (Fts5DlidxIter*)sqlite3_realloc64(pIter, nByte);

  211269.     if( pNew==0 ){

  211270.       p->rc = SQLITE_NOMEM;

  211271.     }else{

  211272.       i64 iRowid = FTS5_DLIDX_ROWID(iSegid, i, iLeafPg);

  211273.       Fts5DlidxLvl *pLvl = &pNew->aLvl[i];

  211274.       pIter = pNew;

  211275.       memset(pLvl, 0, sizeof(Fts5DlidxLvl));

  211276.       pLvl->pData = fts5DataRead(p, iRowid);

  211277.       if( pLvl->pData && (pLvl->pData->p[0] & 0x0001)==0 ){

  211278.         bDone = 1;

  211279.       }

  211280.       pIter->nLvl = i+1;

  211281.     }

  211282.   }

  211283. 

  211284.   if( p->rc==SQLITE_OK ){

  211285.     pIter->iSegid = iSegid;

  211286.     if( bRev==0 ){

  211287.       fts5DlidxIterFirst(pIter);

  211288.     }else{

  211289.       fts5DlidxIterLast(p, pIter);

  211290.     }

  211291.   }

  211292. 

  211293.   if( p->rc!=SQLITE_OK ){

  211294.     fts5DlidxIterFree(pIter);

  211295.     pIter = 0;

  211296.   }

  211297. 

  211298.   return pIter;

  211299. }

  211300. 

  211301. static i64 fts5DlidxIterRowid(Fts5DlidxIter *pIter){

  211302.   return pIter->aLvl[0].iRowid;

  211303. }

  211304. static int fts5DlidxIterPgno(Fts5DlidxIter *pIter){

  211305.   return pIter->aLvl[0].iLeafPgno;

  211306. }

  211307. 

  211308. /*

  211309. ** Load the next leaf page into the segment iterator.

  211310. */

  211311. static void fts5SegIterNextPage(

  211312.   Fts5Index *p,                   /* FTS5 backend object */

  211313.   Fts5SegIter *pIter              /* Iterator to advance to next page */

  211314. ){

  211315.   Fts5Data *pLeaf;

  211316.   Fts5StructureSegment *pSeg = pIter->pSeg;

  211317.   fts5DataRelease(pIter->pLeaf);

  211318.   pIter->iLeafPgno++;

  211319.   if( pIter->pNextLeaf ){

  211320.     pIter->pLeaf = pIter->pNextLeaf;

  211321.     pIter->pNextLeaf = 0;

  211322.   }else if( pIter->iLeafPgno<=pSeg->pgnoLast ){

  211323.     pIter->pLeaf = fts5LeafRead(p, 

  211324.         FTS5_SEGMENT_ROWID(pSeg->iSegid, pIter->iLeafPgno)

  211325.     );

  211326.   }else{

  211327.     pIter->pLeaf = 0;

  211328.   }

  211329.   pLeaf = pIter->pLeaf;

  211330. 

  211331.   if( pLeaf ){

  211332.     pIter->iPgidxOff = pLeaf->szLeaf;

  211333.     if( fts5LeafIsTermless(pLeaf) ){

  211334.       pIter->iEndofDoclist = pLeaf->nn+1;

  211335.     }else{

  211336.       pIter->iPgidxOff += fts5GetVarint32(&pLeaf->p[pIter->iPgidxOff],

  211337.           pIter->iEndofDoclist

  211338.       );

  211339.     }

  211340.   }

  211341. }

  211342. 

  211343. /*

  211344. ** Argument p points to a buffer containing a varint to be interpreted as a

  211345. ** position list size field. Read the varint and return the number of bytes

  211346. ** read. Before returning, set *pnSz to the number of bytes in the position

  211347. ** list, and *pbDel to true if the delete flag is set, or false otherwise.

  211348. */

  211349. static int fts5GetPoslistSize(const u8 *p, int *pnSz, int *pbDel){

  211350.   int nSz;

  211351.   int n = 0;

  211352.   fts5FastGetVarint32(p, n, nSz);

  211353.   assert_nc( nSz>=0 );

  211354.   *pnSz = nSz/2;

  211355.   *pbDel = nSz & 0x0001;

  211356.   return n;

  211357. }

  211358. 

  211359. /*

  211360. ** Fts5SegIter.iLeafOffset currently points to the first byte of a

  211361. ** position-list size field. Read the value of the field and store it

  211362. ** in the following variables:

  211363. **

  211364. **   Fts5SegIter.nPos

  211365. **   Fts5SegIter.bDel

  211366. **

  211367. ** Leave Fts5SegIter.iLeafOffset pointing to the first byte of the 

  211368. ** position list content (if any).

  211369. */

  211370. static void fts5SegIterLoadNPos(Fts5Index *p, Fts5SegIter *pIter){

  211371.   if( p->rc==SQLITE_OK ){

  211372.     int iOff = pIter->iLeafOffset;  /* Offset to read at */

  211373.     ASSERT_SZLEAF_OK(pIter->pLeaf);

  211374.     if( p->pConfig->eDetail==FTS5_DETAIL_NONE ){

  211375.       int iEod = MIN(pIter->iEndofDoclist, pIter->pLeaf->szLeaf);

  211376.       pIter->bDel = 0;

  211377.       pIter->nPos = 1;

  211378.       if( iOff<iEod && pIter->pLeaf->p[iOff]==0 ){

  211379.         pIter->bDel = 1;

  211380.         iOff++;

  211381.         if( iOff<iEod && pIter->pLeaf->p[iOff]==0 ){

  211382.           pIter->nPos = 1;

  211383.           iOff++;

  211384.         }else{

  211385.           pIter->nPos = 0;

  211386.         }

  211387.       }

  211388.     }else{

  211389.       int nSz;

  211390.       fts5FastGetVarint32(pIter->pLeaf->p, iOff, nSz);

  211391.       pIter->bDel = (nSz & 0x0001);

  211392.       pIter->nPos = nSz>>1;

  211393.       assert_nc( pIter->nPos>=0 );

  211394.     }

  211395.     pIter->iLeafOffset = iOff;

  211396.   }

  211397. }

  211398. 

  211399. static void fts5SegIterLoadRowid(Fts5Index *p, Fts5SegIter *pIter){

  211400.   u8 *a = pIter->pLeaf->p;        /* Buffer to read data from */

  211401.   int iOff = pIter->iLeafOffset;

  211402. 

  211403.   ASSERT_SZLEAF_OK(pIter->pLeaf);

  211404.   if( iOff>=pIter->pLeaf->szLeaf ){

  211405.     fts5SegIterNextPage(p, pIter);

  211406.     if( pIter->pLeaf==0 ){

  211407.       if( p->rc==SQLITE_OK ) p->rc = FTS5_CORRUPT;

  211408.       return;

  211409.     }

  211410.     iOff = 4;

  211411.     a = pIter->pLeaf->p;

  211412.   }

  211413.   iOff += sqlite3Fts5GetVarint(&a[iOff], (u64*)&pIter->iRowid);

  211414.   pIter->iLeafOffset = iOff;

  211415. }

  211416. 

  211417. /*

  211418. ** Fts5SegIter.iLeafOffset currently points to the first byte of the 

  211419. ** "nSuffix" field of a term. Function parameter nKeep contains the value

  211420. ** of the "nPrefix" field (if there was one - it is passed 0 if this is

  211421. ** the first term in the segment).

  211422. **

  211423. ** This function populates:

  211424. **

  211425. **   Fts5SegIter.term

  211426. **   Fts5SegIter.rowid

  211427. **

  211428. ** accordingly and leaves (Fts5SegIter.iLeafOffset) set to the content of

  211429. ** the first position list. The position list belonging to document 

  211430. ** (Fts5SegIter.iRowid).

  211431. */

  211432. static void fts5SegIterLoadTerm(Fts5Index *p, Fts5SegIter *pIter, int nKeep){

  211433.   u8 *a = pIter->pLeaf->p;        /* Buffer to read data from */

  211434.   int iOff = pIter->iLeafOffset;  /* Offset to read at */

  211435.   int nNew;                       /* Bytes of new data */

  211436. 

  211437.   iOff += fts5GetVarint32(&a[iOff], nNew);

  211438.   if( iOff+nNew>pIter->pLeaf->szLeaf || nKeep>pIter->term.n || nNew==0 ){

  211439.     p->rc = FTS5_CORRUPT;

  211440.     return;

  211441.   }

  211442.   pIter->term.n = nKeep;

  211443.   fts5BufferAppendBlob(&p->rc, &pIter->term, nNew, &a[iOff]);

  211444.   assert( pIter->term.n<=pIter->term.nSpace );

  211445.   iOff += nNew;

  211446.   pIter->iTermLeafOffset = iOff;

  211447.   pIter->iTermLeafPgno = pIter->iLeafPgno;

  211448.   pIter->iLeafOffset = iOff;

  211449. 

  211450.   if( pIter->iPgidxOff>=pIter->pLeaf->nn ){

  211451.     pIter->iEndofDoclist = pIter->pLeaf->nn+1;

  211452.   }else{

  211453.     int nExtra;

  211454.     pIter->iPgidxOff += fts5GetVarint32(&a[pIter->iPgidxOff], nExtra);

  211455.     pIter->iEndofDoclist += nExtra;

  211456.   }

  211457. 

  211458.   fts5SegIterLoadRowid(p, pIter);

  211459. }

  211460. 

  211461. static void fts5SegIterNext(Fts5Index*, Fts5SegIter*, int*);

  211462. static void fts5SegIterNext_Reverse(Fts5Index*, Fts5SegIter*, int*);

  211463. static void fts5SegIterNext_None(Fts5Index*, Fts5SegIter*, int*);

  211464. 

  211465. static void fts5SegIterSetNext(Fts5Index *p, Fts5SegIter *pIter){

  211466.   if( pIter->flags & FTS5_SEGITER_REVERSE ){

  211467.     pIter->xNext = fts5SegIterNext_Reverse;

  211468.   }else if( p->pConfig->eDetail==FTS5_DETAIL_NONE ){

  211469.     pIter->xNext = fts5SegIterNext_None;

  211470.   }else{

  211471.     pIter->xNext = fts5SegIterNext;

  211472.   }

  211473. }

  211474. 

  211475. /*

  211476. ** Initialize the iterator object pIter to iterate through the entries in

  211477. ** segment pSeg. The iterator is left pointing to the first entry when 

  211478. ** this function returns.

  211479. **

  211480. ** If an error occurs, Fts5Index.rc is set to an appropriate error code. If 

  211481. ** an error has already occurred when this function is called, it is a no-op.

  211482. */

  211483. static void fts5SegIterInit(

  211484.   Fts5Index *p,                   /* FTS index object */

  211485.   Fts5StructureSegment *pSeg,     /* Description of segment */

  211486.   Fts5SegIter *pIter              /* Object to populate */

  211487. ){

  211488.   if( pSeg->pgnoFirst==0 ){

  211489.     /* This happens if the segment is being used as an input to an incremental

  211490.     ** merge and all data has already been "trimmed". See function

  211491.     ** fts5TrimSegments() for details. In this case leave the iterator empty.

  211492.     ** The caller will see the (pIter->pLeaf==0) and assume the iterator is

  211493.     ** at EOF already. */

  211494.     assert( pIter->pLeaf==0 );

  211495.     return;

  211496.   }

  211497. 

  211498.   if( p->rc==SQLITE_OK ){

  211499.     memset(pIter, 0, sizeof(*pIter));

  211500.     fts5SegIterSetNext(p, pIter);

  211501.     pIter->pSeg = pSeg;

  211502.     pIter->iLeafPgno = pSeg->pgnoFirst-1;

  211503.     fts5SegIterNextPage(p, pIter);

  211504.   }

  211505. 

  211506.   if( p->rc==SQLITE_OK ){

  211507.     pIter->iLeafOffset = 4;

  211508.     assert_nc( pIter->pLeaf->nn>4 );

  211509.     assert_nc( fts5LeafFirstTermOff(pIter->pLeaf)==4 );

  211510.     pIter->iPgidxOff = pIter->pLeaf->szLeaf+1;

  211511.     fts5SegIterLoadTerm(p, pIter, 0);

  211512.     fts5SegIterLoadNPos(p, pIter);

  211513.   }

  211514. }

  211515. 

  211516. /*

  211517. ** This function is only ever called on iterators created by calls to

  211518. ** Fts5IndexQuery() with the FTS5INDEX_QUERY_DESC flag set.

  211519. **

  211520. ** The iterator is in an unusual state when this function is called: the

  211521. ** Fts5SegIter.iLeafOffset variable is set to the offset of the start of

  211522. ** the position-list size field for the first relevant rowid on the page.

  211523. ** Fts5SegIter.rowid is set, but nPos and bDel are not.

  211524. **

  211525. ** This function advances the iterator so that it points to the last 

  211526. ** relevant rowid on the page and, if necessary, initializes the 

  211527. ** aRowidOffset[] and iRowidOffset variables. At this point the iterator

  211528. ** is in its regular state - Fts5SegIter.iLeafOffset points to the first

  211529. ** byte of the position list content associated with said rowid.

  211530. */

  211531. static void fts5SegIterReverseInitPage(Fts5Index *p, Fts5SegIter *pIter){

  211532.   int eDetail = p->pConfig->eDetail;

  211533.   int n = pIter->pLeaf->szLeaf;

  211534.   int i = pIter->iLeafOffset;

  211535.   u8 *a = pIter->pLeaf->p;

  211536.   int iRowidOffset = 0;

  211537. 

  211538.   if( n>pIter->iEndofDoclist ){

  211539.     n = pIter->iEndofDoclist;

  211540.   }

  211541. 

  211542.   ASSERT_SZLEAF_OK(pIter->pLeaf);

  211543.   while( 1 ){

  211544.     i64 iDelta = 0;

  211545. 

  211546.     if( eDetail==FTS5_DETAIL_NONE ){

  211547.       /* todo */

  211548.       if( i<n && a[i]==0 ){

  211549.         i++;

  211550.         if( i<n && a[i]==0 ) i++;

  211551.       }

  211552.     }else{

  211553.       int nPos;

  211554.       int bDummy;

  211555.       i += fts5GetPoslistSize(&a[i], &nPos, &bDummy);

  211556.       i += nPos;

  211557.     }

  211558.     if( i>=n ) break;

  211559.     i += fts5GetVarint(&a[i], (u64*)&iDelta);

  211560.     pIter->iRowid += iDelta;

  211561. 

  211562.     /* If necessary, grow the pIter->aRowidOffset[] array. */

  211563.     if( iRowidOffset>=pIter->nRowidOffset ){

  211564.       int nNew = pIter->nRowidOffset + 8;

  211565.       int *aNew = (int*)sqlite3_realloc64(pIter->aRowidOffset,nNew*sizeof(int));

  211566.       if( aNew==0 ){

  211567.         p->rc = SQLITE_NOMEM;

  211568.         break;

  211569.       }

  211570.       pIter->aRowidOffset = aNew;

  211571.       pIter->nRowidOffset = nNew;

  211572.     }

  211573. 

  211574.     pIter->aRowidOffset[iRowidOffset++] = pIter->iLeafOffset;

  211575.     pIter->iLeafOffset = i;

  211576.   }

  211577.   pIter->iRowidOffset = iRowidOffset;

  211578.   fts5SegIterLoadNPos(p, pIter);

  211579. }

  211580. 

  211581. /*

  211582. **

  211583. */

  211584. static void fts5SegIterReverseNewPage(Fts5Index *p, Fts5SegIter *pIter){

  211585.   assert( pIter->flags & FTS5_SEGITER_REVERSE );

  211586.   assert( pIter->flags & FTS5_SEGITER_ONETERM );

  211587. 

  211588.   fts5DataRelease(pIter->pLeaf);

  211589.   pIter->pLeaf = 0;

  211590.   while( p->rc==SQLITE_OK && pIter->iLeafPgno>pIter->iTermLeafPgno ){

  211591.     Fts5Data *pNew;

  211592.     pIter->iLeafPgno--;

  211593.     pNew = fts5DataRead(p, FTS5_SEGMENT_ROWID(

  211594.           pIter->pSeg->iSegid, pIter->iLeafPgno

  211595.     ));

  211596.     if( pNew ){

  211597.       /* iTermLeafOffset may be equal to szLeaf if the term is the last

  211598.       ** thing on the page - i.e. the first rowid is on the following page.

  211599.       ** In this case leave pIter->pLeaf==0, this iterator is at EOF. */

  211600.       if( pIter->iLeafPgno==pIter->iTermLeafPgno ){

  211601.         assert( pIter->pLeaf==0 );

  211602.         if( pIter->iTermLeafOffset<pNew->szLeaf ){

  211603.           pIter->pLeaf = pNew;

  211604.           pIter->iLeafOffset = pIter->iTermLeafOffset;

  211605.         }

  211606.       }else{

  211607.         int iRowidOff;

  211608.         iRowidOff = fts5LeafFirstRowidOff(pNew);

  211609.         if( iRowidOff ){

  211610.           pIter->pLeaf = pNew;

  211611.           pIter->iLeafOffset = iRowidOff;

  211612.         }

  211613.       }

  211614. 

  211615.       if( pIter->pLeaf ){

  211616.         u8 *a = &pIter->pLeaf->p[pIter->iLeafOffset];

  211617.         pIter->iLeafOffset += fts5GetVarint(a, (u64*)&pIter->iRowid);

  211618.         break;

  211619.       }else{

  211620.         fts5DataRelease(pNew);

  211621.       }

  211622.     }

  211623.   }

  211624. 

  211625.   if( pIter->pLeaf ){

  211626.     pIter->iEndofDoclist = pIter->pLeaf->nn+1;

  211627.     fts5SegIterReverseInitPage(p, pIter);

  211628.   }

  211629. }

  211630. 

  211631. /*

  211632. ** Return true if the iterator passed as the second argument currently

  211633. ** points to a delete marker. A delete marker is an entry with a 0 byte

  211634. ** position-list.

  211635. */

  211636. static int fts5MultiIterIsEmpty(Fts5Index *p, Fts5Iter *pIter){

  211637.   Fts5SegIter *pSeg = &pIter->aSeg[pIter->aFirst[1].iFirst];

  211638.   return (p->rc==SQLITE_OK && pSeg->pLeaf && pSeg->nPos==0);

  211639. }

  211640. 

  211641. /*

  211642. ** Advance iterator pIter to the next entry.

  211643. **

  211644. ** This version of fts5SegIterNext() is only used by reverse iterators.

  211645. */

  211646. static void fts5SegIterNext_Reverse(

  211647.   Fts5Index *p,                   /* FTS5 backend object */

  211648.   Fts5SegIter *pIter,             /* Iterator to advance */

  211649.   int *pbUnused                   /* Unused */

  211650. ){

  211651.   assert( pIter->flags & FTS5_SEGITER_REVERSE );

  211652.   assert( pIter->pNextLeaf==0 );

  211653.   UNUSED_PARAM(pbUnused);

  211654. 

  211655.   if( pIter->iRowidOffset>0 ){

  211656.     u8 *a = pIter->pLeaf->p;

  211657.     int iOff;

  211658.     i64 iDelta;

  211659. 

  211660.     pIter->iRowidOffset--;

  211661.     pIter->iLeafOffset = pIter->aRowidOffset[pIter->iRowidOffset];

  211662.     fts5SegIterLoadNPos(p, pIter);

  211663.     iOff = pIter->iLeafOffset;

  211664.     if( p->pConfig->eDetail!=FTS5_DETAIL_NONE ){

  211665.       iOff += pIter->nPos;

  211666.     }

  211667.     fts5GetVarint(&a[iOff], (u64*)&iDelta);

  211668.     pIter->iRowid -= iDelta;

  211669.   }else{

  211670.     fts5SegIterReverseNewPage(p, pIter);

  211671.   }

  211672. }

  211673. 

  211674. /*

  211675. ** Advance iterator pIter to the next entry.

  211676. **

  211677. ** This version of fts5SegIterNext() is only used if detail=none and the

  211678. ** iterator is not a reverse direction iterator.

  211679. */

  211680. static void fts5SegIterNext_None(

  211681.   Fts5Index *p,                   /* FTS5 backend object */

  211682.   Fts5SegIter *pIter,             /* Iterator to advance */

  211683.   int *pbNewTerm                  /* OUT: Set for new term */

  211684. ){

  211685.   int iOff;

  211686. 

  211687.   assert( p->rc==SQLITE_OK );

  211688.   assert( (pIter->flags & FTS5_SEGITER_REVERSE)==0 );

  211689.   assert( p->pConfig->eDetail==FTS5_DETAIL_NONE );

  211690. 

  211691.   ASSERT_SZLEAF_OK(pIter->pLeaf);

  211692.   iOff = pIter->iLeafOffset;

  211693. 

  211694.   /* Next entry is on the next page */

  211695.   if( pIter->pSeg && iOff>=pIter->pLeaf->szLeaf ){

  211696.     fts5SegIterNextPage(p, pIter);

  211697.     if( p->rc || pIter->pLeaf==0 ) return;

  211698.     pIter->iRowid = 0;

  211699.     iOff = 4;

  211700.   }

  211701. 

  211702.   if( iOff<pIter->iEndofDoclist ){

  211703.     /* Next entry is on the current page */

  211704.     i64 iDelta;

  211705.     iOff += sqlite3Fts5GetVarint(&pIter->pLeaf->p[iOff], (u64*)&iDelta);

  211706.     pIter->iLeafOffset = iOff;

  211707.     pIter->iRowid += iDelta;

  211708.   }else if( (pIter->flags & FTS5_SEGITER_ONETERM)==0 ){

  211709.     if( pIter->pSeg ){

  211710.       int nKeep = 0;

  211711.       if( iOff!=fts5LeafFirstTermOff(pIter->pLeaf) ){

  211712.         iOff += fts5GetVarint32(&pIter->pLeaf->p[iOff], nKeep);

  211713.       }

  211714.       pIter->iLeafOffset = iOff;

  211715.       fts5SegIterLoadTerm(p, pIter, nKeep);

  211716.     }else{

  211717.       const u8 *pList = 0;

  211718.       const char *zTerm = 0;

  211719.       int nList;

  211720.       sqlite3Fts5HashScanNext(p->pHash);

  211721.       sqlite3Fts5HashScanEntry(p->pHash, &zTerm, &pList, &nList);

  211722.       if( pList==0 ) goto next_none_eof;

  211723.       pIter->pLeaf->p = (u8*)pList;

  211724.       pIter->pLeaf->nn = nList;

  211725.       pIter->pLeaf->szLeaf = nList;

  211726.       pIter->iEndofDoclist = nList;

  211727.       sqlite3Fts5BufferSet(&p->rc,&pIter->term, (int)strlen(zTerm), (u8*)zTerm);

  211728.       pIter->iLeafOffset = fts5GetVarint(pList, (u64*)&pIter->iRowid);

  211729.     }

  211730. 

  211731.     if( pbNewTerm ) *pbNewTerm = 1;

  211732.   }else{

  211733.     goto next_none_eof;

  211734.   }

  211735. 

  211736.   fts5SegIterLoadNPos(p, pIter);

  211737. 

  211738.   return;

  211739.  next_none_eof:

  211740.   fts5DataRelease(pIter->pLeaf);

  211741.   pIter->pLeaf = 0;

  211742. }

  211743. 

  211744. 

  211745. /*

  211746. ** Advance iterator pIter to the next entry. 

  211747. **

  211748. ** If an error occurs, Fts5Index.rc is set to an appropriate error code. It 

  211749. ** is not considered an error if the iterator reaches EOF. If an error has 

  211750. ** already occurred when this function is called, it is a no-op.

  211751. */

  211752. static void fts5SegIterNext(

  211753.   Fts5Index *p,                   /* FTS5 backend object */

  211754.   Fts5SegIter *pIter,             /* Iterator to advance */

  211755.   int *pbNewTerm                  /* OUT: Set for new term */

  211756. ){

  211757.   Fts5Data *pLeaf = pIter->pLeaf;

  211758.   int iOff;

  211759.   int bNewTerm = 0;

  211760.   int nKeep = 0;

  211761.   u8 *a;

  211762.   int n;

  211763. 

  211764.   assert( pbNewTerm==0 || *pbNewTerm==0 );

  211765.   assert( p->pConfig->eDetail!=FTS5_DETAIL_NONE );

  211766. 

  211767.   /* Search for the end of the position list within the current page. */

  211768.   a = pLeaf->p;

  211769.   n = pLeaf->szLeaf;

  211770. 

  211771.   ASSERT_SZLEAF_OK(pLeaf);

  211772.   iOff = pIter->iLeafOffset + pIter->nPos;

  211773. 

  211774.   if( iOff<n ){

  211775.     /* The next entry is on the current page. */

  211776.     assert_nc( iOff<=pIter->iEndofDoclist );

  211777.     if( iOff>=pIter->iEndofDoclist ){

  211778.       bNewTerm = 1;

  211779.       if( iOff!=fts5LeafFirstTermOff(pLeaf) ){

  211780.         iOff += fts5GetVarint32(&a[iOff], nKeep);

  211781.       }

  211782.     }else{

  211783.       u64 iDelta;

  211784.       iOff += sqlite3Fts5GetVarint(&a[iOff], &iDelta);

  211785.       pIter->iRowid += iDelta;

  211786.       assert_nc( iDelta>0 );

  211787.     }

  211788.     pIter->iLeafOffset = iOff;

  211789. 

  211790.   }else if( pIter->pSeg==0 ){

  211791.     const u8 *pList = 0;

  211792.     const char *zTerm = 0;

  211793.     int nList = 0;

  211794.     assert( (pIter->flags & FTS5_SEGITER_ONETERM) || pbNewTerm );

  211795.     if( 0==(pIter->flags & FTS5_SEGITER_ONETERM) ){

  211796.       sqlite3Fts5HashScanNext(p->pHash);

  211797.       sqlite3Fts5HashScanEntry(p->pHash, &zTerm, &pList, &nList);

  211798.     }

  211799.     if( pList==0 ){

  211800.       fts5DataRelease(pIter->pLeaf);

  211801.       pIter->pLeaf = 0;

  211802.     }else{

  211803.       pIter->pLeaf->p = (u8*)pList;

  211804.       pIter->pLeaf->nn = nList;

  211805.       pIter->pLeaf->szLeaf = nList;

  211806.       pIter->iEndofDoclist = nList+1;

  211807.       sqlite3Fts5BufferSet(&p->rc, &pIter->term, (int)strlen(zTerm),

  211808.           (u8*)zTerm);

  211809.       pIter->iLeafOffset = fts5GetVarint(pList, (u64*)&pIter->iRowid);

  211810.       *pbNewTerm = 1;

  211811.     }

  211812.   }else{

  211813.     iOff = 0;

  211814.     /* Next entry is not on the current page */

  211815.     while( iOff==0 ){

  211816.       fts5SegIterNextPage(p, pIter);

  211817.       pLeaf = pIter->pLeaf;

  211818.       if( pLeaf==0 ) break;

  211819.       ASSERT_SZLEAF_OK(pLeaf);

  211820.       if( (iOff = fts5LeafFirstRowidOff(pLeaf)) && iOff<pLeaf->szLeaf ){

  211821.         iOff += sqlite3Fts5GetVarint(&pLeaf->p[iOff], (u64*)&pIter->iRowid);

  211822.         pIter->iLeafOffset = iOff;

  211823. 

  211824.         if( pLeaf->nn>pLeaf->szLeaf ){

  211825.           pIter->iPgidxOff = pLeaf->szLeaf + fts5GetVarint32(

  211826.               &pLeaf->p[pLeaf->szLeaf], pIter->iEndofDoclist

  211827.           );

  211828.         }

  211829.       }

  211830.       else if( pLeaf->nn>pLeaf->szLeaf ){

  211831.         pIter->iPgidxOff = pLeaf->szLeaf + fts5GetVarint32(

  211832.             &pLeaf->p[pLeaf->szLeaf], iOff

  211833.         );

  211834.         pIter->iLeafOffset = iOff;

  211835.         pIter->iEndofDoclist = iOff;

  211836.         bNewTerm = 1;

  211837.       }

  211838.       assert_nc( iOff<pLeaf->szLeaf );

  211839.       if( iOff>pLeaf->szLeaf ){

  211840.         p->rc = FTS5_CORRUPT;

  211841.         return;

  211842.       }

  211843.     }

  211844.   }

  211845. 

  211846.   /* Check if the iterator is now at EOF. If so, return early. */

  211847.   if( pIter->pLeaf ){

  211848.     if( bNewTerm ){

  211849.       if( pIter->flags & FTS5_SEGITER_ONETERM ){

  211850.         fts5DataRelease(pIter->pLeaf);

  211851.         pIter->pLeaf = 0;

  211852.       }else{

  211853.         fts5SegIterLoadTerm(p, pIter, nKeep);

  211854.         fts5SegIterLoadNPos(p, pIter);

  211855.         if( pbNewTerm ) *pbNewTerm = 1;

  211856.       }

  211857.     }else{

  211858.       /* The following could be done by calling fts5SegIterLoadNPos(). But

  211859.       ** this block is particularly performance critical, so equivalent

  211860.       ** code is inlined. 

  211861.       **

  211862.       ** Later: Switched back to fts5SegIterLoadNPos() because it supports

  211863.       ** detail=none mode. Not ideal.

  211864.       */

  211865.       int nSz;

  211866.       assert( p->rc==SQLITE_OK );

  211867.       assert( pIter->iLeafOffset<=pIter->pLeaf->nn );

  211868.       fts5FastGetVarint32(pIter->pLeaf->p, pIter->iLeafOffset, nSz);

  211869.       pIter->bDel = (nSz & 0x0001);

  211870.       pIter->nPos = nSz>>1;

  211871.       assert_nc( pIter->nPos>=0 );

  211872.     }

  211873.   }

  211874. }

  211875. 

  211876. #define SWAPVAL(T, a, b) { T tmp; tmp=a; a=b; b=tmp; }

  211877. 

  211878. #define fts5IndexSkipVarint(a, iOff) {            \

  211879.   int iEnd = iOff+9;                              \

  211880.   while( (a[iOff++] & 0x80) && iOff<iEnd );       \

  211881. }

  211882. 

  211883. /*

  211884. ** Iterator pIter currently points to the first rowid in a doclist. This

  211885. ** function sets the iterator up so that iterates in reverse order through

  211886. ** the doclist.

  211887. */

  211888. static void fts5SegIterReverse(Fts5Index *p, Fts5SegIter *pIter){

  211889.   Fts5DlidxIter *pDlidx = pIter->pDlidx;

  211890.   Fts5Data *pLast = 0;

  211891.   int pgnoLast = 0;

  211892. 

  211893.   if( pDlidx ){

  211894.     int iSegid = pIter->pSeg->iSegid;

  211895.     pgnoLast = fts5DlidxIterPgno(pDlidx);

  211896.     pLast = fts5DataRead(p, FTS5_SEGMENT_ROWID(iSegid, pgnoLast));

  211897.   }else{

  211898.     Fts5Data *pLeaf = pIter->pLeaf;         /* Current leaf data */

  211899. 

  211900.     /* Currently, Fts5SegIter.iLeafOffset points to the first byte of

  211901.     ** position-list content for the current rowid. Back it up so that it

  211902.     ** points to the start of the position-list size field. */

  211903.     int iPoslist;

  211904.     if( pIter->iTermLeafPgno==pIter->iLeafPgno ){

  211905.       iPoslist = pIter->iTermLeafOffset;

  211906.     }else{

  211907.       iPoslist = 4;

  211908.     }

  211909.     fts5IndexSkipVarint(pLeaf->p, iPoslist);

  211910.     pIter->iLeafOffset = iPoslist;

  211911. 

  211912.     /* If this condition is true then the largest rowid for the current

  211913.     ** term may not be stored on the current page. So search forward to

  211914.     ** see where said rowid really is.  */

  211915.     if( pIter->iEndofDoclist>=pLeaf->szLeaf ){

  211916.       int pgno;

  211917.       Fts5StructureSegment *pSeg = pIter->pSeg;

  211918. 

  211919.       /* The last rowid in the doclist may not be on the current page. Search

  211920.       ** forward to find the page containing the last rowid.  */

  211921.       for(pgno=pIter->iLeafPgno+1; !p->rc && pgno<=pSeg->pgnoLast; pgno++){

  211922.         i64 iAbs = FTS5_SEGMENT_ROWID(pSeg->iSegid, pgno);

  211923.         Fts5Data *pNew = fts5DataRead(p, iAbs);

  211924.         if( pNew ){

  211925.           int iRowid, bTermless;

  211926.           iRowid = fts5LeafFirstRowidOff(pNew);

  211927.           bTermless = fts5LeafIsTermless(pNew);

  211928.           if( iRowid ){

  211929.             SWAPVAL(Fts5Data*, pNew, pLast);

  211930.             pgnoLast = pgno;

  211931.           }

  211932.           fts5DataRelease(pNew);

  211933.           if( bTermless==0 ) break;

  211934.         }

  211935.       }

  211936.     }

  211937.   }

  211938. 

  211939.   /* If pLast is NULL at this point, then the last rowid for this doclist

  211940.   ** lies on the page currently indicated by the iterator. In this case 

  211941.   ** pIter->iLeafOffset is already set to point to the position-list size

  211942.   ** field associated with the first relevant rowid on the page.

  211943.   **

  211944.   ** Or, if pLast is non-NULL, then it is the page that contains the last

  211945.   ** rowid. In this case configure the iterator so that it points to the

  211946.   ** first rowid on this page.

  211947.   */

  211948.   if( pLast ){

  211949.     int iOff;

  211950.     fts5DataRelease(pIter->pLeaf);

  211951.     pIter->pLeaf = pLast;

  211952.     pIter->iLeafPgno = pgnoLast;

  211953.     iOff = fts5LeafFirstRowidOff(pLast);

  211954.     iOff += fts5GetVarint(&pLast->p[iOff], (u64*)&pIter->iRowid);

  211955.     pIter->iLeafOffset = iOff;

  211956. 

  211957.     if( fts5LeafIsTermless(pLast) ){

  211958.       pIter->iEndofDoclist = pLast->nn+1;

  211959.     }else{

  211960.       pIter->iEndofDoclist = fts5LeafFirstTermOff(pLast);

  211961.     }

  211962. 

  211963.   }

  211964. 

  211965.   fts5SegIterReverseInitPage(p, pIter);

  211966. }

  211967. 

  211968. /*

  211969. ** Iterator pIter currently points to the first rowid of a doclist.

  211970. ** There is a doclist-index associated with the final term on the current 

  211971. ** page. If the current term is the last term on the page, load the 

  211972. ** doclist-index from disk and initialize an iterator at (pIter->pDlidx).

  211973. */

  211974. static void fts5SegIterLoadDlidx(Fts5Index *p, Fts5SegIter *pIter){

  211975.   int iSeg = pIter->pSeg->iSegid;

  211976.   int bRev = (pIter->flags & FTS5_SEGITER_REVERSE);

  211977.   Fts5Data *pLeaf = pIter->pLeaf; /* Current leaf data */

  211978. 

  211979.   assert( pIter->flags & FTS5_SEGITER_ONETERM );

  211980.   assert( pIter->pDlidx==0 );

  211981. 

  211982.   /* Check if the current doclist ends on this page. If it does, return

  211983.   ** early without loading the doclist-index (as it belongs to a different

  211984.   ** term. */

  211985.   if( pIter->iTermLeafPgno==pIter->iLeafPgno 

  211986.    && pIter->iEndofDoclist<pLeaf->szLeaf 

  211987.   ){

  211988.     return;

  211989.   }

  211990. 

  211991.   pIter->pDlidx = fts5DlidxIterInit(p, bRev, iSeg, pIter->iTermLeafPgno);

  211992. }

  211993. 

  211994. /*

  211995. ** The iterator object passed as the second argument currently contains

  211996. ** no valid values except for the Fts5SegIter.pLeaf member variable. This

  211997. ** function searches the leaf page for a term matching (pTerm/nTerm).

  211998. **

  211999. ** If the specified term is found on the page, then the iterator is left

  212000. ** pointing to it. If argument bGe is zero and the term is not found,

  212001. ** the iterator is left pointing at EOF.

  212002. **

  212003. ** If bGe is non-zero and the specified term is not found, then the

  212004. ** iterator is left pointing to the smallest term in the segment that

  212005. ** is larger than the specified term, even if this term is not on the

  212006. ** current page.

  212007. */

  212008. static void fts5LeafSeek(

  212009.   Fts5Index *p,                   /* Leave any error code here */

  212010.   int bGe,                        /* True for a >= search */

  212011.   Fts5SegIter *pIter,             /* Iterator to seek */

  212012.   const u8 *pTerm, int nTerm      /* Term to search for */

  212013. ){

  212014.   int iOff;

  212015.   const u8 *a = pIter->pLeaf->p;

  212016.   int szLeaf = pIter->pLeaf->szLeaf;

  212017.   int n = pIter->pLeaf->nn;

  212018. 

  212019.   u32 nMatch = 0;

  212020.   u32 nKeep = 0;

  212021.   u32 nNew = 0;

  212022.   u32 iTermOff;

  212023.   int iPgidx;                     /* Current offset in pgidx */

  212024.   int bEndOfPage = 0;

  212025. 

  212026.   assert( p->rc==SQLITE_OK );

  212027. 

  212028.   iPgidx = szLeaf;

  212029.   iPgidx += fts5GetVarint32(&a[iPgidx], iTermOff);

  212030.   iOff = iTermOff;

  212031.   if( iOff>n ){

  212032.     p->rc = FTS5_CORRUPT;

  212033.     return;

  212034.   }

  212035. 

  212036.   while( 1 ){

  212037. 

  212038.     /* Figure out how many new bytes are in this term */

  212039.     fts5FastGetVarint32(a, iOff, nNew);

  212040.     if( nKeep<nMatch ){

  212041.       goto search_failed;

  212042.     }

  212043. 

  212044.     assert( nKeep>=nMatch );

  212045.     if( nKeep==nMatch ){

  212046.       u32 nCmp;

  212047.       u32 i;

  212048.       nCmp = (u32)MIN(nNew, nTerm-nMatch);

  212049.       for(i=0; i<nCmp; i++){

  212050.         if( a[iOff+i]!=pTerm[nMatch+i] ) break;

  212051.       }

  212052.       nMatch += i;

  212053. 

  212054.       if( (u32)nTerm==nMatch ){

  212055.         if( i==nNew ){

  212056.           goto search_success;

  212057.         }else{

  212058.           goto search_failed;

  212059.         }

  212060.       }else if( i<nNew && a[iOff+i]>pTerm[nMatch] ){

  212061.         goto search_failed;

  212062.       }

  212063.     }

  212064. 

  212065.     if( iPgidx>=n ){

  212066.       bEndOfPage = 1;

  212067.       break;

  212068.     }

  212069. 

  212070.     iPgidx += fts5GetVarint32(&a[iPgidx], nKeep);

  212071.     iTermOff += nKeep;

  212072.     iOff = iTermOff;

  212073. 

  212074.     if( iOff>=n ){

  212075.       p->rc = FTS5_CORRUPT;

  212076.       return;

  212077.     }

  212078. 

  212079.     /* Read the nKeep field of the next term. */

  212080.     fts5FastGetVarint32(a, iOff, nKeep);

  212081.   }

  212082. 

  212083.  search_failed:

  212084.   if( bGe==0 ){

  212085.     fts5DataRelease(pIter->pLeaf);

  212086.     pIter->pLeaf = 0;

  212087.     return;

  212088.   }else if( bEndOfPage ){

  212089.     do {

  212090.       fts5SegIterNextPage(p, pIter);

  212091.       if( pIter->pLeaf==0 ) return;

  212092.       a = pIter->pLeaf->p;

  212093.       if( fts5LeafIsTermless(pIter->pLeaf)==0 ){

  212094.         iPgidx = pIter->pLeaf->szLeaf;

  212095.         iPgidx += fts5GetVarint32(&pIter->pLeaf->p[iPgidx], iOff);

  212096.         if( iOff<4 || iOff>=pIter->pLeaf->szLeaf ){

  212097.           p->rc = FTS5_CORRUPT;

  212098.           return;

  212099.         }else{

  212100.           nKeep = 0;

  212101.           iTermOff = iOff;

  212102.           n = pIter->pLeaf->nn;

  212103.           iOff += fts5GetVarint32(&a[iOff], nNew);

  212104.           break;

  212105.         }

  212106.       }

  212107.     }while( 1 );

  212108.   }

  212109. 

  212110.  search_success:

  212111.   pIter->iLeafOffset = iOff + nNew;

  212112.   if( pIter->iLeafOffset>n || nNew<1 ){

  212113.     p->rc = FTS5_CORRUPT;

  212114.     return;

  212115.   }

  212116.   pIter->iTermLeafOffset = pIter->iLeafOffset;

  212117.   pIter->iTermLeafPgno = pIter->iLeafPgno;

  212118. 

  212119.   fts5BufferSet(&p->rc, &pIter->term, nKeep, pTerm);

  212120.   fts5BufferAppendBlob(&p->rc, &pIter->term, nNew, &a[iOff]);

  212121. 

  212122.   if( iPgidx>=n ){

  212123.     pIter->iEndofDoclist = pIter->pLeaf->nn+1;

  212124.   }else{

  212125.     int nExtra;

  212126.     iPgidx += fts5GetVarint32(&a[iPgidx], nExtra);

  212127.     pIter->iEndofDoclist = iTermOff + nExtra;

  212128.   }

  212129.   pIter->iPgidxOff = iPgidx;

  212130. 

  212131.   fts5SegIterLoadRowid(p, pIter);

  212132.   fts5SegIterLoadNPos(p, pIter);

  212133. }

  212134. 

  212135. static sqlite3_stmt *fts5IdxSelectStmt(Fts5Index *p){

  212136.   if( p->pIdxSelect==0 ){

  212137.     Fts5Config *pConfig = p->pConfig;

  212138.     fts5IndexPrepareStmt(p, &p->pIdxSelect, sqlite3_mprintf(

  212139.           "SELECT pgno FROM '%q'.'%q_idx' WHERE "

  212140.           "segid=? AND term<=? ORDER BY term DESC LIMIT 1",

  212141.           pConfig->zDb, pConfig->zName

  212142.     ));

  212143.   }

  212144.   return p->pIdxSelect;

  212145. }

  212146. 

  212147. /*

  212148. ** Initialize the object pIter to point to term pTerm/nTerm within segment

  212149. ** pSeg. If there is no such term in the index, the iterator is set to EOF.

  212150. **

  212151. ** If an error occurs, Fts5Index.rc is set to an appropriate error code. If 

  212152. ** an error has already occurred when this function is called, it is a no-op.

  212153. */

  212154. static void fts5SegIterSeekInit(

  212155.   Fts5Index *p,                   /* FTS5 backend */

  212156.   const u8 *pTerm, int nTerm,     /* Term to seek to */

  212157.   int flags,                      /* Mask of FTS5INDEX_XXX flags */

  212158.   Fts5StructureSegment *pSeg,     /* Description of segment */

  212159.   Fts5SegIter *pIter              /* Object to populate */

  212160. ){

  212161.   int iPg = 1;

  212162.   int bGe = (flags & FTS5INDEX_QUERY_SCAN);

  212163.   int bDlidx = 0;                 /* True if there is a doclist-index */

  212164.   sqlite3_stmt *pIdxSelect = 0;

  212165. 

  212166.   assert( bGe==0 || (flags & FTS5INDEX_QUERY_DESC)==0 );

  212167.   assert( pTerm && nTerm );

  212168.   memset(pIter, 0, sizeof(*pIter));

  212169.   pIter->pSeg = pSeg;

  212170. 

  212171.   /* This block sets stack variable iPg to the leaf page number that may

  212172.   ** contain term (pTerm/nTerm), if it is present in the segment. */

  212173.   pIdxSelect = fts5IdxSelectStmt(p);

  212174.   if( p->rc ) return;

  212175.   sqlite3_bind_int(pIdxSelect, 1, pSeg->iSegid);

  212176.   sqlite3_bind_blob(pIdxSelect, 2, pTerm, nTerm, SQLITE_STATIC);

  212177.   if( SQLITE_ROW==sqlite3_step(pIdxSelect) ){

  212178.     i64 val = sqlite3_column_int(pIdxSelect, 0);

  212179.     iPg = (int)(val>>1);

  212180.     bDlidx = (val & 0x0001);

  212181.   }

  212182.   p->rc = sqlite3_reset(pIdxSelect);

  212183.   sqlite3_bind_null(pIdxSelect, 2);

  212184. 

  212185.   if( iPg<pSeg->pgnoFirst ){

  212186.     iPg = pSeg->pgnoFirst;

  212187.     bDlidx = 0;

  212188.   }

  212189. 

  212190.   pIter->iLeafPgno = iPg - 1;

  212191.   fts5SegIterNextPage(p, pIter);

  212192. 

  212193.   if( pIter->pLeaf ){

  212194.     fts5LeafSeek(p, bGe, pIter, pTerm, nTerm);

  212195.   }

  212196. 

  212197.   if( p->rc==SQLITE_OK && bGe==0 ){

  212198.     pIter->flags |= FTS5_SEGITER_ONETERM;

  212199.     if( pIter->pLeaf ){

  212200.       if( flags & FTS5INDEX_QUERY_DESC ){

  212201.         pIter->flags |= FTS5_SEGITER_REVERSE;

  212202.       }

  212203.       if( bDlidx ){

  212204.         fts5SegIterLoadDlidx(p, pIter);

  212205.       }

  212206.       if( flags & FTS5INDEX_QUERY_DESC ){

  212207.         fts5SegIterReverse(p, pIter);

  212208.       }

  212209.     }

  212210.   }

  212211. 

  212212.   fts5SegIterSetNext(p, pIter);

  212213. 

  212214.   /* Either:

  212215.   **

  212216.   **   1) an error has occurred, or

  212217.   **   2) the iterator points to EOF, or

  212218.   **   3) the iterator points to an entry with term (pTerm/nTerm), or

  212219.   **   4) the FTS5INDEX_QUERY_SCAN flag was set and the iterator points

  212220.   **      to an entry with a term greater than or equal to (pTerm/nTerm).

  212221.   */

  212222.   assert_nc( p->rc!=SQLITE_OK                                       /* 1 */

  212223.    || pIter->pLeaf==0                                               /* 2 */

  212224.    || fts5BufferCompareBlob(&pIter->term, pTerm, nTerm)==0          /* 3 */

  212225.    || (bGe && fts5BufferCompareBlob(&pIter->term, pTerm, nTerm)>0)  /* 4 */

  212226.   );

  212227. }

  212228. 

  212229. /*

  212230. ** Initialize the object pIter to point to term pTerm/nTerm within the

  212231. ** in-memory hash table. If there is no such term in the hash-table, the 

  212232. ** iterator is set to EOF.

  212233. **

  212234. ** If an error occurs, Fts5Index.rc is set to an appropriate error code. If 

  212235. ** an error has already occurred when this function is called, it is a no-op.

  212236. */

  212237. static void fts5SegIterHashInit(

  212238.   Fts5Index *p,                   /* FTS5 backend */

  212239.   const u8 *pTerm, int nTerm,     /* Term to seek to */

  212240.   int flags,                      /* Mask of FTS5INDEX_XXX flags */

  212241.   Fts5SegIter *pIter              /* Object to populate */

  212242. ){

  212243.   int nList = 0;

  212244.   const u8 *z = 0;

  212245.   int n = 0;

  212246.   Fts5Data *pLeaf = 0;

  212247. 

  212248.   assert( p->pHash );

  212249.   assert( p->rc==SQLITE_OK );

  212250. 

  212251.   if( pTerm==0 || (flags & FTS5INDEX_QUERY_SCAN) ){

  212252.     const u8 *pList = 0;

  212253. 

  212254.     p->rc = sqlite3Fts5HashScanInit(p->pHash, (const char*)pTerm, nTerm);

  212255.     sqlite3Fts5HashScanEntry(p->pHash, (const char**)&z, &pList, &nList);

  212256.     n = (z ? (int)strlen((const char*)z) : 0);

  212257.     if( pList ){

  212258.       pLeaf = fts5IdxMalloc(p, sizeof(Fts5Data));

  212259.       if( pLeaf ){

  212260.         pLeaf->p = (u8*)pList;

  212261.       }

  212262.     }

  212263.   }else{

  212264.     p->rc = sqlite3Fts5HashQuery(p->pHash, sizeof(Fts5Data), 

  212265.         (const char*)pTerm, nTerm, (void**)&pLeaf, &nList

  212266.     );

  212267.     if( pLeaf ){

  212268.       pLeaf->p = (u8*)&pLeaf[1];

  212269.     }

  212270.     z = pTerm;

  212271.     n = nTerm;

  212272.     pIter->flags |= FTS5_SEGITER_ONETERM;

  212273.   }

  212274. 

  212275.   if( pLeaf ){

  212276.     sqlite3Fts5BufferSet(&p->rc, &pIter->term, n, z);

  212277.     pLeaf->nn = pLeaf->szLeaf = nList;

  212278.     pIter->pLeaf = pLeaf;

  212279.     pIter->iLeafOffset = fts5GetVarint(pLeaf->p, (u64*)&pIter->iRowid);

  212280.     pIter->iEndofDoclist = pLeaf->nn;

  212281. 

  212282.     if( flags & FTS5INDEX_QUERY_DESC ){

  212283.       pIter->flags |= FTS5_SEGITER_REVERSE;

  212284.       fts5SegIterReverseInitPage(p, pIter);

  212285.     }else{

  212286.       fts5SegIterLoadNPos(p, pIter);

  212287.     }

  212288.   }

  212289. 

  212290.   fts5SegIterSetNext(p, pIter);

  212291. }

  212292. 

  212293. /*

  212294. ** Zero the iterator passed as the only argument.

  212295. */

  212296. static void fts5SegIterClear(Fts5SegIter *pIter){

  212297.   fts5BufferFree(&pIter->term);

  212298.   fts5DataRelease(pIter->pLeaf);

  212299.   fts5DataRelease(pIter->pNextLeaf);

  212300.   fts5DlidxIterFree(pIter->pDlidx);

  212301.   sqlite3_free(pIter->aRowidOffset);

  212302.   memset(pIter, 0, sizeof(Fts5SegIter));

  212303. }

  212304. 

  212305. #ifdef SQLITE_DEBUG

  212306. 

  212307. /*

  212308. ** This function is used as part of the big assert() procedure implemented by

  212309. ** fts5AssertMultiIterSetup(). It ensures that the result currently stored

  212310. ** in *pRes is the correct result of comparing the current positions of the

  212311. ** two iterators.

  212312. */

  212313. static void fts5AssertComparisonResult(

  212314.   Fts5Iter *pIter, 

  212315.   Fts5SegIter *p1,

  212316.   Fts5SegIter *p2,

  212317.   Fts5CResult *pRes

  212318. ){

  212319.   int i1 = p1 - pIter->aSeg;

  212320.   int i2 = p2 - pIter->aSeg;

  212321. 

  212322.   if( p1->pLeaf || p2->pLeaf ){

  212323.     if( p1->pLeaf==0 ){

  212324.       assert( pRes->iFirst==i2 );

  212325.     }else if( p2->pLeaf==0 ){

  212326.       assert( pRes->iFirst==i1 );

  212327.     }else{

  212328.       int nMin = MIN(p1->term.n, p2->term.n);

  212329.       int res = fts5Memcmp(p1->term.p, p2->term.p, nMin);

  212330.       if( res==0 ) res = p1->term.n - p2->term.n;

  212331. 

  212332.       if( res==0 ){

  212333.         assert( pRes->bTermEq==1 );

  212334.         assert( p1->iRowid!=p2->iRowid );

  212335.         res = ((p1->iRowid > p2->iRowid)==pIter->bRev) ? -1 : 1;

  212336.       }else{

  212337.         assert( pRes->bTermEq==0 );

  212338.       }

  212339. 

  212340.       if( res<0 ){

  212341.         assert( pRes->iFirst==i1 );

  212342.       }else{

  212343.         assert( pRes->iFirst==i2 );

  212344.       }

  212345.     }

  212346.   }

  212347. }

  212348. 

  212349. /*

  212350. ** This function is a no-op unless SQLITE_DEBUG is defined when this module

  212351. ** is compiled. In that case, this function is essentially an assert() 

  212352. ** statement used to verify that the contents of the pIter->aFirst[] array

  212353. ** are correct.

  212354. */

  212355. static void fts5AssertMultiIterSetup(Fts5Index *p, Fts5Iter *pIter){

  212356.   if( p->rc==SQLITE_OK ){

  212357.     Fts5SegIter *pFirst = &pIter->aSeg[ pIter->aFirst[1].iFirst ];

  212358.     int i;

  212359. 

  212360.     assert( (pFirst->pLeaf==0)==pIter->base.bEof );

  212361. 

  212362.     /* Check that pIter->iSwitchRowid is set correctly. */

  212363.     for(i=0; i<pIter->nSeg; i++){

  212364.       Fts5SegIter *p1 = &pIter->aSeg[i];

  212365.       assert( p1==pFirst 

  212366.            || p1->pLeaf==0 

  212367.            || fts5BufferCompare(&pFirst->term, &p1->term) 

  212368.            || p1->iRowid==pIter->iSwitchRowid

  212369.            || (p1->iRowid<pIter->iSwitchRowid)==pIter->bRev

  212370.       );

  212371.     }

  212372. 

  212373.     for(i=0; i<pIter->nSeg; i+=2){

  212374.       Fts5SegIter *p1 = &pIter->aSeg[i];

  212375.       Fts5SegIter *p2 = &pIter->aSeg[i+1];

  212376.       Fts5CResult *pRes = &pIter->aFirst[(pIter->nSeg + i) / 2];

  212377.       fts5AssertComparisonResult(pIter, p1, p2, pRes);

  212378.     }

  212379. 

  212380.     for(i=1; i<(pIter->nSeg / 2); i+=2){

  212381.       Fts5SegIter *p1 = &pIter->aSeg[ pIter->aFirst[i*2].iFirst ];

  212382.       Fts5SegIter *p2 = &pIter->aSeg[ pIter->aFirst[i*2+1].iFirst ];

  212383.       Fts5CResult *pRes = &pIter->aFirst[i];

  212384.       fts5AssertComparisonResult(pIter, p1, p2, pRes);

  212385.     }

  212386.   }

  212387. }

  212388. #else

  212389. # define fts5AssertMultiIterSetup(x,y)

  212390. #endif

  212391. 

  212392. /*

  212393. ** Do the comparison necessary to populate pIter->aFirst[iOut].

  212394. **

  212395. ** If the returned value is non-zero, then it is the index of an entry

  212396. ** in the pIter->aSeg[] array that is (a) not at EOF, and (b) pointing

  212397. ** to a key that is a duplicate of another, higher priority, 

  212398. ** segment-iterator in the pSeg->aSeg[] array.

  212399. */

  212400. static int fts5MultiIterDoCompare(Fts5Iter *pIter, int iOut){

  212401.   int i1;                         /* Index of left-hand Fts5SegIter */

  212402.   int i2;                         /* Index of right-hand Fts5SegIter */

  212403.   int iRes;

  212404.   Fts5SegIter *p1;                /* Left-hand Fts5SegIter */

  212405.   Fts5SegIter *p2;                /* Right-hand Fts5SegIter */

  212406.   Fts5CResult *pRes = &pIter->aFirst[iOut];

  212407. 

  212408.   assert( iOut<pIter->nSeg && iOut>0 );

  212409.   assert( pIter->bRev==0 || pIter->bRev==1 );

  212410. 

  212411.   if( iOut>=(pIter->nSeg/2) ){

  212412.     i1 = (iOut - pIter->nSeg/2) * 2;

  212413.     i2 = i1 + 1;

  212414.   }else{

  212415.     i1 = pIter->aFirst[iOut*2].iFirst;

  212416.     i2 = pIter->aFirst[iOut*2+1].iFirst;

  212417.   }

  212418.   p1 = &pIter->aSeg[i1];

  212419.   p2 = &pIter->aSeg[i2];

  212420. 

  212421.   pRes->bTermEq = 0;

  212422.   if( p1->pLeaf==0 ){           /* If p1 is at EOF */

  212423.     iRes = i2;

  212424.   }else if( p2->pLeaf==0 ){     /* If p2 is at EOF */

  212425.     iRes = i1;

  212426.   }else{

  212427.     int res = fts5BufferCompare(&p1->term, &p2->term);

  212428.     if( res==0 ){

  212429.       assert_nc( i2>i1 );

  212430.       assert_nc( i2!=0 );

  212431.       pRes->bTermEq = 1;

  212432.       if( p1->iRowid==p2->iRowid ){

  212433.         p1->bDel = p2->bDel;

  212434.         return i2;

  212435.       }

  212436.       res = ((p1->iRowid > p2->iRowid)==pIter->bRev) ? -1 : +1;

  212437.     }

  212438.     assert( res!=0 );

  212439.     if( res<0 ){

  212440.       iRes = i1;

  212441.     }else{

  212442.       iRes = i2;

  212443.     }

  212444.   }

  212445. 

  212446.   pRes->iFirst = (u16)iRes;

  212447.   return 0;

  212448. }

  212449. 

  212450. /*

  212451. ** Move the seg-iter so that it points to the first rowid on page iLeafPgno.

  212452. ** It is an error if leaf iLeafPgno does not exist or contains no rowids.

  212453. */

  212454. static void fts5SegIterGotoPage(

  212455.   Fts5Index *p,                   /* FTS5 backend object */

  212456.   Fts5SegIter *pIter,             /* Iterator to advance */

  212457.   int iLeafPgno

  212458. ){

  212459.   assert( iLeafPgno>pIter->iLeafPgno );

  212460. 

  212461.   if( iLeafPgno>pIter->pSeg->pgnoLast ){

  212462.     p->rc = FTS5_CORRUPT;

  212463.   }else{

  212464.     fts5DataRelease(pIter->pNextLeaf);

  212465.     pIter->pNextLeaf = 0;

  212466.     pIter->iLeafPgno = iLeafPgno-1;

  212467.     fts5SegIterNextPage(p, pIter);

  212468.     assert( p->rc!=SQLITE_OK || pIter->iLeafPgno==iLeafPgno );

  212469. 

  212470.     if( p->rc==SQLITE_OK ){

  212471.       int iOff;

  212472.       u8 *a = pIter->pLeaf->p;

  212473.       int n = pIter->pLeaf->szLeaf;

  212474. 

  212475.       iOff = fts5LeafFirstRowidOff(pIter->pLeaf);

  212476.       if( iOff<4 || iOff>=n ){

  212477.         p->rc = FTS5_CORRUPT;

  212478.       }else{

  212479.         iOff += fts5GetVarint(&a[iOff], (u64*)&pIter->iRowid);

  212480.         pIter->iLeafOffset = iOff;

  212481.         fts5SegIterLoadNPos(p, pIter);

  212482.       }

  212483.     }

  212484.   }

  212485. }

  212486. 

  212487. /*

  212488. ** Advance the iterator passed as the second argument until it is at or 

  212489. ** past rowid iFrom. Regardless of the value of iFrom, the iterator is

  212490. ** always advanced at least once.

  212491. */

  212492. static void fts5SegIterNextFrom(

  212493.   Fts5Index *p,                   /* FTS5 backend object */

  212494.   Fts5SegIter *pIter,             /* Iterator to advance */

  212495.   i64 iMatch                      /* Advance iterator at least this far */

  212496. ){

  212497.   int bRev = (pIter->flags & FTS5_SEGITER_REVERSE);

  212498.   Fts5DlidxIter *pDlidx = pIter->pDlidx;

  212499.   int iLeafPgno = pIter->iLeafPgno;

  212500.   int bMove = 1;

  212501. 

  212502.   assert( pIter->flags & FTS5_SEGITER_ONETERM );

  212503.   assert( pIter->pDlidx );

  212504.   assert( pIter->pLeaf );

  212505. 

  212506.   if( bRev==0 ){

  212507.     while( !fts5DlidxIterEof(p, pDlidx) && iMatch>fts5DlidxIterRowid(pDlidx) ){

  212508.       iLeafPgno = fts5DlidxIterPgno(pDlidx);

  212509.       fts5DlidxIterNext(p, pDlidx);

  212510.     }

  212511.     assert_nc( iLeafPgno>=pIter->iLeafPgno || p->rc );

  212512.     if( iLeafPgno>pIter->iLeafPgno ){

  212513.       fts5SegIterGotoPage(p, pIter, iLeafPgno);

  212514.       bMove = 0;

  212515.     }

  212516.   }else{

  212517.     assert( pIter->pNextLeaf==0 );

  212518.     assert( iMatch<pIter->iRowid );

  212519.     while( !fts5DlidxIterEof(p, pDlidx) && iMatch<fts5DlidxIterRowid(pDlidx) ){

  212520.       fts5DlidxIterPrev(p, pDlidx);

  212521.     }

  212522.     iLeafPgno = fts5DlidxIterPgno(pDlidx);

  212523. 

  212524.     assert( fts5DlidxIterEof(p, pDlidx) || iLeafPgno<=pIter->iLeafPgno );

  212525. 

  212526.     if( iLeafPgno<pIter->iLeafPgno ){

  212527.       pIter->iLeafPgno = iLeafPgno+1;

  212528.       fts5SegIterReverseNewPage(p, pIter);

  212529.       bMove = 0;

  212530.     }

  212531.   }

  212532. 

  212533.   do{

  212534.     if( bMove && p->rc==SQLITE_OK ) pIter->xNext(p, pIter, 0);

  212535.     if( pIter->pLeaf==0 ) break;

  212536.     if( bRev==0 && pIter->iRowid>=iMatch ) break;

  212537.     if( bRev!=0 && pIter->iRowid<=iMatch ) break;

  212538.     bMove = 1;

  212539.   }while( p->rc==SQLITE_OK );

  212540. }

  212541. 

  212542. 

  212543. /*

  212544. ** Free the iterator object passed as the second argument.

  212545. */

  212546. static void fts5MultiIterFree(Fts5Iter *pIter){

  212547.   if( pIter ){

  212548.     int i;

  212549.     for(i=0; i<pIter->nSeg; i++){

  212550.       fts5SegIterClear(&pIter->aSeg[i]);

  212551.     }

  212552.     fts5BufferFree(&pIter->poslist);

  212553.     sqlite3_free(pIter);

  212554.   }

  212555. }

  212556. 

  212557. static void fts5MultiIterAdvanced(

  212558.   Fts5Index *p,                   /* FTS5 backend to iterate within */

  212559.   Fts5Iter *pIter,                /* Iterator to update aFirst[] array for */

  212560.   int iChanged,                   /* Index of sub-iterator just advanced */

  212561.   int iMinset                     /* Minimum entry in aFirst[] to set */

  212562. ){

  212563.   int i;

  212564.   for(i=(pIter->nSeg+iChanged)/2; i>=iMinset && p->rc==SQLITE_OK; i=i/2){

  212565.     int iEq;

  212566.     if( (iEq = fts5MultiIterDoCompare(pIter, i)) ){

  212567.       Fts5SegIter *pSeg = &pIter->aSeg[iEq];

  212568.       assert( p->rc==SQLITE_OK );

  212569.       pSeg->xNext(p, pSeg, 0);

  212570.       i = pIter->nSeg + iEq;

  212571.     }

  212572.   }

  212573. }

  212574. 

  212575. /*

  212576. ** Sub-iterator iChanged of iterator pIter has just been advanced. It still

  212577. ** points to the same term though - just a different rowid. This function

  212578. ** attempts to update the contents of the pIter->aFirst[] accordingly.

  212579. ** If it does so successfully, 0 is returned. Otherwise 1.

  212580. **

  212581. ** If non-zero is returned, the caller should call fts5MultiIterAdvanced()

  212582. ** on the iterator instead. That function does the same as this one, except

  212583. ** that it deals with more complicated cases as well.

  212584. */ 

  212585. static int fts5MultiIterAdvanceRowid(

  212586.   Fts5Iter *pIter,                /* Iterator to update aFirst[] array for */

  212587.   int iChanged,                   /* Index of sub-iterator just advanced */

  212588.   Fts5SegIter **ppFirst

  212589. ){

  212590.   Fts5SegIter *pNew = &pIter->aSeg[iChanged];

  212591. 

  212592.   if( pNew->iRowid==pIter->iSwitchRowid

  212593.    || (pNew->iRowid<pIter->iSwitchRowid)==pIter->bRev

  212594.   ){

  212595.     int i;

  212596.     Fts5SegIter *pOther = &pIter->aSeg[iChanged ^ 0x0001];

  212597.     pIter->iSwitchRowid = pIter->bRev ? SMALLEST_INT64 : LARGEST_INT64;

  212598.     for(i=(pIter->nSeg+iChanged)/2; 1; i=i/2){

  212599.       Fts5CResult *pRes = &pIter->aFirst[i];

  212600. 

  212601.       assert( pNew->pLeaf );

  212602.       assert( pRes->bTermEq==0 || pOther->pLeaf );

  212603. 

  212604.       if( pRes->bTermEq ){

  212605.         if( pNew->iRowid==pOther->iRowid ){

  212606.           return 1;

  212607.         }else if( (pOther->iRowid>pNew->iRowid)==pIter->bRev ){

  212608.           pIter->iSwitchRowid = pOther->iRowid;

  212609.           pNew = pOther;

  212610.         }else if( (pOther->iRowid>pIter->iSwitchRowid)==pIter->bRev ){

  212611.           pIter->iSwitchRowid = pOther->iRowid;

  212612.         }

  212613.       }

  212614.       pRes->iFirst = (u16)(pNew - pIter->aSeg);

  212615.       if( i==1 ) break;

  212616. 

  212617.       pOther = &pIter->aSeg[ pIter->aFirst[i ^ 0x0001].iFirst ];

  212618.     }

  212619.   }

  212620. 

  212621.   *ppFirst = pNew;

  212622.   return 0;

  212623. }

  212624. 

  212625. /*

  212626. ** Set the pIter->bEof variable based on the state of the sub-iterators.

  212627. */

  212628. static void fts5MultiIterSetEof(Fts5Iter *pIter){

  212629.   Fts5SegIter *pSeg = &pIter->aSeg[ pIter->aFirst[1].iFirst ];

  212630.   pIter->base.bEof = pSeg->pLeaf==0;

  212631.   pIter->iSwitchRowid = pSeg->iRowid;

  212632. }

  212633. 

  212634. /*

  212635. ** Move the iterator to the next entry. 

  212636. **

  212637. ** If an error occurs, an error code is left in Fts5Index.rc. It is not 

  212638. ** considered an error if the iterator reaches EOF, or if it is already at 

  212639. ** EOF when this function is called.

  212640. */

  212641. static void fts5MultiIterNext(

  212642.   Fts5Index *p, 

  212643.   Fts5Iter *pIter,

  212644.   int bFrom,                      /* True if argument iFrom is valid */

  212645.   i64 iFrom                       /* Advance at least as far as this */

  212646. ){

  212647.   int bUseFrom = bFrom;

  212648.   assert( pIter->base.bEof==0 );

  212649.   while( p->rc==SQLITE_OK ){

  212650.     int iFirst = pIter->aFirst[1].iFirst;

  212651.     int bNewTerm = 0;

  212652.     Fts5SegIter *pSeg = &pIter->aSeg[iFirst];

  212653.     assert( p->rc==SQLITE_OK );

  212654.     if( bUseFrom && pSeg->pDlidx ){

  212655.       fts5SegIterNextFrom(p, pSeg, iFrom);

  212656.     }else{

  212657.       pSeg->xNext(p, pSeg, &bNewTerm);

  212658.     }

  212659. 

  212660.     if( pSeg->pLeaf==0 || bNewTerm 

  212661.      || fts5MultiIterAdvanceRowid(pIter, iFirst, &pSeg)

  212662.     ){

  212663.       fts5MultiIterAdvanced(p, pIter, iFirst, 1);

  212664.       fts5MultiIterSetEof(pIter);

  212665.       pSeg = &pIter->aSeg[pIter->aFirst[1].iFirst];

  212666.       if( pSeg->pLeaf==0 ) return;

  212667.     }

  212668. 

  212669.     fts5AssertMultiIterSetup(p, pIter);

  212670.     assert( pSeg==&pIter->aSeg[pIter->aFirst[1].iFirst] && pSeg->pLeaf );

  212671.     if( pIter->bSkipEmpty==0 || pSeg->nPos ){

  212672.       pIter->xSetOutputs(pIter, pSeg);

  212673.       return;

  212674.     }

  212675.     bUseFrom = 0;

  212676.   }

  212677. }

  212678. 

  212679. static void fts5MultiIterNext2(

  212680.   Fts5Index *p, 

  212681.   Fts5Iter *pIter,

  212682.   int *pbNewTerm                  /* OUT: True if *might* be new term */

  212683. ){

  212684.   assert( pIter->bSkipEmpty );

  212685.   if( p->rc==SQLITE_OK ){

  212686.     *pbNewTerm = 0;

  212687.     do{

  212688.       int iFirst = pIter->aFirst[1].iFirst;

  212689.       Fts5SegIter *pSeg = &pIter->aSeg[iFirst];

  212690.       int bNewTerm = 0;

  212691. 

  212692.       assert( p->rc==SQLITE_OK );

  212693.       pSeg->xNext(p, pSeg, &bNewTerm);

  212694.       if( pSeg->pLeaf==0 || bNewTerm 

  212695.        || fts5MultiIterAdvanceRowid(pIter, iFirst, &pSeg)

  212696.       ){

  212697.         fts5MultiIterAdvanced(p, pIter, iFirst, 1);

  212698.         fts5MultiIterSetEof(pIter);

  212699.         *pbNewTerm = 1;

  212700.       }

  212701.       fts5AssertMultiIterSetup(p, pIter);

  212702. 

  212703.     }while( fts5MultiIterIsEmpty(p, pIter) );

  212704.   }

  212705. }

  212706. 

  212707. static void fts5IterSetOutputs_Noop(Fts5Iter *pUnused1, Fts5SegIter *pUnused2){

  212708.   UNUSED_PARAM2(pUnused1, pUnused2);

  212709. }

  212710. 

  212711. static Fts5Iter *fts5MultiIterAlloc(

  212712.   Fts5Index *p,                   /* FTS5 backend to iterate within */

  212713.   int nSeg

  212714. ){

  212715.   Fts5Iter *pNew;

  212716.   int nSlot;                      /* Power of two >= nSeg */

  212717. 

  212718.   for(nSlot=2; nSlot<nSeg; nSlot=nSlot*2);

  212719.   pNew = fts5IdxMalloc(p, 

  212720.       sizeof(Fts5Iter) +                  /* pNew */

  212721.       sizeof(Fts5SegIter) * (nSlot-1) +   /* pNew->aSeg[] */

  212722.       sizeof(Fts5CResult) * nSlot         /* pNew->aFirst[] */

  212723.   );

  212724.   if( pNew ){

  212725.     pNew->nSeg = nSlot;

  212726.     pNew->aFirst = (Fts5CResult*)&pNew->aSeg[nSlot];

  212727.     pNew->pIndex = p;

  212728.     pNew->xSetOutputs = fts5IterSetOutputs_Noop;

  212729.   }

  212730.   return pNew;

  212731. }

  212732. 

  212733. static void fts5PoslistCallback(

  212734.   Fts5Index *pUnused, 

  212735.   void *pContext, 

  212736.   const u8 *pChunk, int nChunk

  212737. ){

  212738.   UNUSED_PARAM(pUnused);

  212739.   assert_nc( nChunk>=0 );

  212740.   if( nChunk>0 ){

  212741.     fts5BufferSafeAppendBlob((Fts5Buffer*)pContext, pChunk, nChunk);

  212742.   }

  212743. }

  212744. 

  212745. typedef struct PoslistCallbackCtx PoslistCallbackCtx;

  212746. struct PoslistCallbackCtx {

  212747.   Fts5Buffer *pBuf;               /* Append to this buffer */

  212748.   Fts5Colset *pColset;            /* Restrict matches to this column */

  212749.   int eState;                     /* See above */

  212750. };

  212751. 

  212752. typedef struct PoslistOffsetsCtx PoslistOffsetsCtx;

  212753. struct PoslistOffsetsCtx {

  212754.   Fts5Buffer *pBuf;               /* Append to this buffer */

  212755.   Fts5Colset *pColset;            /* Restrict matches to this column */

  212756.   int iRead;

  212757.   int iWrite;

  212758. };

  212759. 

  212760. /*

  212761. ** TODO: Make this more efficient!

  212762. */

  212763. static int fts5IndexColsetTest(Fts5Colset *pColset, int iCol){

  212764.   int i;

  212765.   for(i=0; i<pColset->nCol; i++){

  212766.     if( pColset->aiCol[i]==iCol ) return 1;

  212767.   }

  212768.   return 0;

  212769. }

  212770. 

  212771. static void fts5PoslistOffsetsCallback(

  212772.   Fts5Index *pUnused, 

  212773.   void *pContext, 

  212774.   const u8 *pChunk, int nChunk

  212775. ){

  212776.   PoslistOffsetsCtx *pCtx = (PoslistOffsetsCtx*)pContext;

  212777.   UNUSED_PARAM(pUnused);

  212778.   assert_nc( nChunk>=0 );

  212779.   if( nChunk>0 ){

  212780.     int i = 0;

  212781.     while( i<nChunk ){

  212782.       int iVal;

  212783.       i += fts5GetVarint32(&pChunk[i], iVal);

  212784.       iVal += pCtx->iRead - 2;

  212785.       pCtx->iRead = iVal;

  212786.       if( fts5IndexColsetTest(pCtx->pColset, iVal) ){

  212787.         fts5BufferSafeAppendVarint(pCtx->pBuf, iVal + 2 - pCtx->iWrite);

  212788.         pCtx->iWrite = iVal;

  212789.       }

  212790.     }

  212791.   }

  212792. }

  212793. 

  212794. static void fts5PoslistFilterCallback(

  212795.   Fts5Index *pUnused,

  212796.   void *pContext, 

  212797.   const u8 *pChunk, int nChunk

  212798. ){

  212799.   PoslistCallbackCtx *pCtx = (PoslistCallbackCtx*)pContext;

  212800.   UNUSED_PARAM(pUnused);

  212801.   assert_nc( nChunk>=0 );

  212802.   if( nChunk>0 ){

  212803.     /* Search through to find the first varint with value 1. This is the

  212804.     ** start of the next columns hits. */

  212805.     int i = 0;

  212806.     int iStart = 0;

  212807. 

  212808.     if( pCtx->eState==2 ){

  212809.       int iCol;

  212810.       fts5FastGetVarint32(pChunk, i, iCol);

  212811.       if( fts5IndexColsetTest(pCtx->pColset, iCol) ){

  212812.         pCtx->eState = 1;

  212813.         fts5BufferSafeAppendVarint(pCtx->pBuf, 1);

  212814.       }else{

  212815.         pCtx->eState = 0;

  212816.       }

  212817.     }

  212818. 

  212819.     do {

  212820.       while( i<nChunk && pChunk[i]!=0x01 ){

  212821.         while( pChunk[i] & 0x80 ) i++;

  212822.         i++;

  212823.       }

  212824.       if( pCtx->eState ){

  212825.         fts5BufferSafeAppendBlob(pCtx->pBuf, &pChunk[iStart], i-iStart);

  212826.       }

  212827.       if( i<nChunk ){

  212828.         int iCol;

  212829.         iStart = i;

  212830.         i++;

  212831.         if( i>=nChunk ){

  212832.           pCtx->eState = 2;

  212833.         }else{

  212834.           fts5FastGetVarint32(pChunk, i, iCol);

  212835.           pCtx->eState = fts5IndexColsetTest(pCtx->pColset, iCol);

  212836.           if( pCtx->eState ){

  212837.             fts5BufferSafeAppendBlob(pCtx->pBuf, &pChunk[iStart], i-iStart);

  212838.             iStart = i;

  212839.           }

  212840.         }

  212841.       }

  212842.     }while( i<nChunk );

  212843.   }

  212844. }

  212845. 

  212846. static void fts5ChunkIterate(

  212847.   Fts5Index *p,                   /* Index object */

  212848.   Fts5SegIter *pSeg,              /* Poslist of this iterator */

  212849.   void *pCtx,                     /* Context pointer for xChunk callback */

  212850.   void (*xChunk)(Fts5Index*, void*, const u8*, int)

  212851. ){

  212852.   int nRem = pSeg->nPos;          /* Number of bytes still to come */

  212853.   Fts5Data *pData = 0;

  212854.   u8 *pChunk = &pSeg->pLeaf->p[pSeg->iLeafOffset];

  212855.   int nChunk = MIN(nRem, pSeg->pLeaf->szLeaf - pSeg->iLeafOffset);

  212856.   int pgno = pSeg->iLeafPgno;

  212857.   int pgnoSave = 0;

  212858. 

  212859.   /* This function does notmwork with detail=none databases. */

  212860.   assert( p->pConfig->eDetail!=FTS5_DETAIL_NONE );

  212861. 

  212862.   if( (pSeg->flags & FTS5_SEGITER_REVERSE)==0 ){

  212863.     pgnoSave = pgno+1;

  212864.   }

  212865. 

  212866.   while( 1 ){

  212867.     xChunk(p, pCtx, pChunk, nChunk);

  212868.     nRem -= nChunk;

  212869.     fts5DataRelease(pData);

  212870.     if( nRem<=0 ){

  212871.       break;

  212872.     }else{

  212873.       pgno++;

  212874.       pData = fts5LeafRead(p, FTS5_SEGMENT_ROWID(pSeg->pSeg->iSegid, pgno));

  212875.       if( pData==0 ) break;

  212876.       pChunk = &pData->p[4];

  212877.       nChunk = MIN(nRem, pData->szLeaf - 4);

  212878.       if( pgno==pgnoSave ){

  212879.         assert( pSeg->pNextLeaf==0 );

  212880.         pSeg->pNextLeaf = pData;

  212881.         pData = 0;

  212882.       }

  212883.     }

  212884.   }

  212885. }

  212886. 

  212887. /*

  212888. ** Iterator pIter currently points to a valid entry (not EOF). This

  212889. ** function appends the position list data for the current entry to

  212890. ** buffer pBuf. It does not make a copy of the position-list size

  212891. ** field.

  212892. */

  212893. static void fts5SegiterPoslist(

  212894.   Fts5Index *p,

  212895.   Fts5SegIter *pSeg,

  212896.   Fts5Colset *pColset,

  212897.   Fts5Buffer *pBuf

  212898. ){

  212899.   if( 0==fts5BufferGrow(&p->rc, pBuf, pSeg->nPos+FTS5_DATA_ZERO_PADDING) ){

  212900.     memset(&pBuf->p[pBuf->n+pSeg->nPos], 0, FTS5_DATA_ZERO_PADDING);

  212901.     if( pColset==0 ){

  212902.       fts5ChunkIterate(p, pSeg, (void*)pBuf, fts5PoslistCallback);

  212903.     }else{

  212904.       if( p->pConfig->eDetail==FTS5_DETAIL_FULL ){

  212905.         PoslistCallbackCtx sCtx;

  212906.         sCtx.pBuf = pBuf;

  212907.         sCtx.pColset = pColset;

  212908.         sCtx.eState = fts5IndexColsetTest(pColset, 0);

  212909.         assert( sCtx.eState==0 || sCtx.eState==1 );

  212910.         fts5ChunkIterate(p, pSeg, (void*)&sCtx, fts5PoslistFilterCallback);

  212911.       }else{

  212912.         PoslistOffsetsCtx sCtx;

  212913.         memset(&sCtx, 0, sizeof(sCtx));

  212914.         sCtx.pBuf = pBuf;

  212915.         sCtx.pColset = pColset;

  212916.         fts5ChunkIterate(p, pSeg, (void*)&sCtx, fts5PoslistOffsetsCallback);

  212917.       }

  212918.     }

  212919.   }

  212920. }

  212921. 

  212922. /*

  212923. ** IN/OUT parameter (*pa) points to a position list n bytes in size. If

  212924. ** the position list contains entries for column iCol, then (*pa) is set

  212925. ** to point to the sub-position-list for that column and the number of

  212926. ** bytes in it returned. Or, if the argument position list does not

  212927. ** contain any entries for column iCol, return 0.

  212928. */

  212929. static int fts5IndexExtractCol(

  212930.   const u8 **pa,                  /* IN/OUT: Pointer to poslist */

  212931.   int n,                          /* IN: Size of poslist in bytes */

  212932.   int iCol                        /* Column to extract from poslist */

  212933. ){

  212934.   int iCurrent = 0;               /* Anything before the first 0x01 is col 0 */

  212935.   const u8 *p = *pa;

  212936.   const u8 *pEnd = &p[n];         /* One byte past end of position list */

  212937. 

  212938.   while( iCol>iCurrent ){

  212939.     /* Advance pointer p until it points to pEnd or an 0x01 byte that is

  212940.     ** not part of a varint. Note that it is not possible for a negative

  212941.     ** or extremely large varint to occur within an uncorrupted position 

  212942.     ** list. So the last byte of each varint may be assumed to have a clear

  212943.     ** 0x80 bit.  */

  212944.     while( *p!=0x01 ){

  212945.       while( *p++ & 0x80 );

  212946.       if( p>=pEnd ) return 0;

  212947.     }

  212948.     *pa = p++;

  212949.     iCurrent = *p++;

  212950.     if( iCurrent & 0x80 ){

  212951.       p--;

  212952.       p += fts5GetVarint32(p, iCurrent);

  212953.     }

  212954.   }

  212955.   if( iCol!=iCurrent ) return 0;

  212956. 

  212957.   /* Advance pointer p until it points to pEnd or an 0x01 byte that is

  212958.   ** not part of a varint */

  212959.   while( p<pEnd && *p!=0x01 ){

  212960.     while( *p++ & 0x80 );

  212961.   }

  212962. 

  212963.   return p - (*pa);

  212964. }

  212965. 

  212966. static void fts5IndexExtractColset(

  212967.   int *pRc,

  212968.   Fts5Colset *pColset,            /* Colset to filter on */

  212969.   const u8 *pPos, int nPos,       /* Position list */

  212970.   Fts5Buffer *pBuf                /* Output buffer */

  212971. ){

  212972.   if( *pRc==SQLITE_OK ){

  212973.     int i;

  212974.     fts5BufferZero(pBuf);

  212975.     for(i=0; i<pColset->nCol; i++){

  212976.       const u8 *pSub = pPos;

  212977.       int nSub = fts5IndexExtractCol(&pSub, nPos, pColset->aiCol[i]);

  212978.       if( nSub ){

  212979.         fts5BufferAppendBlob(pRc, pBuf, nSub, pSub);

  212980.       }

  212981.     }

  212982.   }

  212983. }

  212984. 

  212985. /*

  212986. ** xSetOutputs callback used by detail=none tables.

  212987. */

  212988. static void fts5IterSetOutputs_None(Fts5Iter *pIter, Fts5SegIter *pSeg){

  212989.   assert( pIter->pIndex->pConfig->eDetail==FTS5_DETAIL_NONE );

  212990.   pIter->base.iRowid = pSeg->iRowid;

  212991.   pIter->base.nData = pSeg->nPos;

  212992. }

  212993. 

  212994. /*

  212995. ** xSetOutputs callback used by detail=full and detail=col tables when no

  212996. ** column filters are specified.

  212997. */

  212998. static void fts5IterSetOutputs_Nocolset(Fts5Iter *pIter, Fts5SegIter *pSeg){

  212999.   pIter->base.iRowid = pSeg->iRowid;

  213000.   pIter->base.nData = pSeg->nPos;

  213001. 

  213002.   assert( pIter->pIndex->pConfig->eDetail!=FTS5_DETAIL_NONE );

  213003.   assert( pIter->pColset==0 );

  213004. 

  213005.   if( pSeg->iLeafOffset+pSeg->nPos<=pSeg->pLeaf->szLeaf ){

  213006.     /* All data is stored on the current page. Populate the output 

  213007.     ** variables to point into the body of the page object. */

  213008.     pIter->base.pData = &pSeg->pLeaf->p[pSeg->iLeafOffset];

  213009.   }else{

  213010.     /* The data is distributed over two or more pages. Copy it into the

  213011.     ** Fts5Iter.poslist buffer and then set the output pointer to point

  213012.     ** to this buffer.  */

  213013.     fts5BufferZero(&pIter->poslist);

  213014.     fts5SegiterPoslist(pIter->pIndex, pSeg, 0, &pIter->poslist);

  213015.     pIter->base.pData = pIter->poslist.p;

  213016.   }

  213017. }

  213018. 

  213019. /*

  213020. ** xSetOutputs callback used when the Fts5Colset object has nCol==0 (match

  213021. ** against no columns at all).

  213022. */

  213023. static void fts5IterSetOutputs_ZeroColset(Fts5Iter *pIter, Fts5SegIter *pSeg){

  213024.   UNUSED_PARAM(pSeg);

  213025.   pIter->base.nData = 0;

  213026. }

  213027. 

  213028. /*

  213029. ** xSetOutputs callback used by detail=col when there is a column filter

  213030. ** and there are 100 or more columns. Also called as a fallback from

  213031. ** fts5IterSetOutputs_Col100 if the column-list spans more than one page.

  213032. */

  213033. static void fts5IterSetOutputs_Col(Fts5Iter *pIter, Fts5SegIter *pSeg){

  213034.   fts5BufferZero(&pIter->poslist);

  213035.   fts5SegiterPoslist(pIter->pIndex, pSeg, pIter->pColset, &pIter->poslist);

  213036.   pIter->base.iRowid = pSeg->iRowid;

  213037.   pIter->base.pData = pIter->poslist.p;

  213038.   pIter->base.nData = pIter->poslist.n;

  213039. }

  213040. 

  213041. /*

  213042. ** xSetOutputs callback used when: 

  213043. **

  213044. **   * detail=col,

  213045. **   * there is a column filter, and

  213046. **   * the table contains 100 or fewer columns. 

  213047. **

  213048. ** The last point is to ensure all column numbers are stored as 

  213049. ** single-byte varints.

  213050. */

  213051. static void fts5IterSetOutputs_Col100(Fts5Iter *pIter, Fts5SegIter *pSeg){

  213052. 

  213053.   assert( pIter->pIndex->pConfig->eDetail==FTS5_DETAIL_COLUMNS );

  213054.   assert( pIter->pColset );

  213055. 

  213056.   if( pSeg->iLeafOffset+pSeg->nPos>pSeg->pLeaf->szLeaf ){

  213057.     fts5IterSetOutputs_Col(pIter, pSeg);

  213058.   }else{

  213059.     u8 *a = (u8*)&pSeg->pLeaf->p[pSeg->iLeafOffset];

  213060.     u8 *pEnd = (u8*)&a[pSeg->nPos]; 

  213061.     int iPrev = 0;

  213062.     int *aiCol = pIter->pColset->aiCol;

  213063.     int *aiColEnd = &aiCol[pIter->pColset->nCol];

  213064. 

  213065.     u8 *aOut = pIter->poslist.p;

  213066.     int iPrevOut = 0;

  213067. 

  213068.     pIter->base.iRowid = pSeg->iRowid;

  213069. 

  213070.     while( a<pEnd ){

  213071.       iPrev += (int)a++[0] - 2;

  213072.       while( *aiCol<iPrev ){

  213073.         aiCol++;

  213074.         if( aiCol==aiColEnd ) goto setoutputs_col_out;

  213075.       }

  213076.       if( *aiCol==iPrev ){

  213077.         *aOut++ = (u8)((iPrev - iPrevOut) + 2);

  213078.         iPrevOut = iPrev;

  213079.       }

  213080.     }

  213081. 

  213082. setoutputs_col_out:

  213083.     pIter->base.pData = pIter->poslist.p;

  213084.     pIter->base.nData = aOut - pIter->poslist.p;

  213085.   }

  213086. }

  213087. 

  213088. /*

  213089. ** xSetOutputs callback used by detail=full when there is a column filter.

  213090. */

  213091. static void fts5IterSetOutputs_Full(Fts5Iter *pIter, Fts5SegIter *pSeg){

  213092.   Fts5Colset *pColset = pIter->pColset;

  213093.   pIter->base.iRowid = pSeg->iRowid;

  213094. 

  213095.   assert( pIter->pIndex->pConfig->eDetail==FTS5_DETAIL_FULL );

  213096.   assert( pColset );

  213097. 

  213098.   if( pSeg->iLeafOffset+pSeg->nPos<=pSeg->pLeaf->szLeaf ){

  213099.     /* All data is stored on the current page. Populate the output 

  213100.     ** variables to point into the body of the page object. */

  213101.     const u8 *a = &pSeg->pLeaf->p[pSeg->iLeafOffset];

  213102.     if( pColset->nCol==1 ){

  213103.       pIter->base.nData = fts5IndexExtractCol(&a, pSeg->nPos,pColset->aiCol[0]);

  213104.       pIter->base.pData = a;

  213105.     }else{

  213106.       int *pRc = &pIter->pIndex->rc;

  213107.       fts5BufferZero(&pIter->poslist);

  213108.       fts5IndexExtractColset(pRc, pColset, a, pSeg->nPos, &pIter->poslist);

  213109.       pIter->base.pData = pIter->poslist.p;

  213110.       pIter->base.nData = pIter->poslist.n;

  213111.     }

  213112.   }else{

  213113.     /* The data is distributed over two or more pages. Copy it into the

  213114.     ** Fts5Iter.poslist buffer and then set the output pointer to point

  213115.     ** to this buffer.  */

  213116.     fts5BufferZero(&pIter->poslist);

  213117.     fts5SegiterPoslist(pIter->pIndex, pSeg, pColset, &pIter->poslist);

  213118.     pIter->base.pData = pIter->poslist.p;

  213119.     pIter->base.nData = pIter->poslist.n;

  213120.   }

  213121. }

  213122. 

  213123. static void fts5IterSetOutputCb(int *pRc, Fts5Iter *pIter){

  213124.   if( *pRc==SQLITE_OK ){

  213125.     Fts5Config *pConfig = pIter->pIndex->pConfig;

  213126.     if( pConfig->eDetail==FTS5_DETAIL_NONE ){

  213127.       pIter->xSetOutputs = fts5IterSetOutputs_None;

  213128.     }

  213129. 

  213130.     else if( pIter->pColset==0 ){

  213131.       pIter->xSetOutputs = fts5IterSetOutputs_Nocolset;

  213132.     }

  213133. 

  213134.     else if( pIter->pColset->nCol==0 ){

  213135.       pIter->xSetOutputs = fts5IterSetOutputs_ZeroColset;

  213136.     }

  213137. 

  213138.     else if( pConfig->eDetail==FTS5_DETAIL_FULL ){

  213139.       pIter->xSetOutputs = fts5IterSetOutputs_Full;

  213140.     }

  213141. 

  213142.     else{

  213143.       assert( pConfig->eDetail==FTS5_DETAIL_COLUMNS );

  213144.       if( pConfig->nCol<=100 ){

  213145.         pIter->xSetOutputs = fts5IterSetOutputs_Col100;

  213146.         sqlite3Fts5BufferSize(pRc, &pIter->poslist, pConfig->nCol);

  213147.       }else{

  213148.         pIter->xSetOutputs = fts5IterSetOutputs_Col;

  213149.       }

  213150.     }

  213151.   }

  213152. }

  213153. 

  213154. 

  213155. /*

  213156. ** Allocate a new Fts5Iter object.

  213157. **

  213158. ** The new object will be used to iterate through data in structure pStruct.

  213159. ** If iLevel is -ve, then all data in all segments is merged. Or, if iLevel

  213160. ** is zero or greater, data from the first nSegment segments on level iLevel

  213161. ** is merged.

  213162. **

  213163. ** The iterator initially points to the first term/rowid entry in the 

  213164. ** iterated data.

  213165. */

  213166. static void fts5MultiIterNew(

  213167.   Fts5Index *p,                   /* FTS5 backend to iterate within */

  213168.   Fts5Structure *pStruct,         /* Structure of specific index */

  213169.   int flags,                      /* FTS5INDEX_QUERY_XXX flags */

  213170.   Fts5Colset *pColset,            /* Colset to filter on (or NULL) */

  213171.   const u8 *pTerm, int nTerm,     /* Term to seek to (or NULL/0) */

  213172.   int iLevel,                     /* Level to iterate (-1 for all) */

  213173.   int nSegment,                   /* Number of segments to merge (iLevel>=0) */

  213174.   Fts5Iter **ppOut                /* New object */

  213175. ){

  213176.   int nSeg = 0;                   /* Number of segment-iters in use */

  213177.   int iIter = 0;                  /* */

  213178.   int iSeg;                       /* Used to iterate through segments */

  213179.   Fts5StructureLevel *pLvl;

  213180.   Fts5Iter *pNew;

  213181. 

  213182.   assert( (pTerm==0 && nTerm==0) || iLevel<0 );

  213183. 

  213184.   /* Allocate space for the new multi-seg-iterator. */

  213185.   if( p->rc==SQLITE_OK ){

  213186.     if( iLevel<0 ){

  213187.       assert( pStruct->nSegment==fts5StructureCountSegments(pStruct) );

  213188.       nSeg = pStruct->nSegment;

  213189.       nSeg += (p->pHash ? 1 : 0);

  213190.     }else{

  213191.       nSeg = MIN(pStruct->aLevel[iLevel].nSeg, nSegment);

  213192.     }

  213193.   }

  213194.   *ppOut = pNew = fts5MultiIterAlloc(p, nSeg);

  213195.   if( pNew==0 ) return;

  213196.   pNew->bRev = (0!=(flags & FTS5INDEX_QUERY_DESC));

  213197.   pNew->bSkipEmpty = (0!=(flags & FTS5INDEX_QUERY_SKIPEMPTY));

  213198.   pNew->pColset = pColset;

  213199.   if( (flags & FTS5INDEX_QUERY_NOOUTPUT)==0 ){

  213200.     fts5IterSetOutputCb(&p->rc, pNew);

  213201.   }

  213202. 

  213203.   /* Initialize each of the component segment iterators. */

  213204.   if( p->rc==SQLITE_OK ){

  213205.     if( iLevel<0 ){

  213206.       Fts5StructureLevel *pEnd = &pStruct->aLevel[pStruct->nLevel];

  213207.       if( p->pHash ){

  213208.         /* Add a segment iterator for the current contents of the hash table. */

  213209.         Fts5SegIter *pIter = &pNew->aSeg[iIter++];

  213210.         fts5SegIterHashInit(p, pTerm, nTerm, flags, pIter);

  213211.       }

  213212.       for(pLvl=&pStruct->aLevel[0]; pLvl<pEnd; pLvl++){

  213213.         for(iSeg=pLvl->nSeg-1; iSeg>=0; iSeg--){

  213214.           Fts5StructureSegment *pSeg = &pLvl->aSeg[iSeg];

  213215.           Fts5SegIter *pIter = &pNew->aSeg[iIter++];

  213216.           if( pTerm==0 ){

  213217.             fts5SegIterInit(p, pSeg, pIter);

  213218.           }else{

  213219.             fts5SegIterSeekInit(p, pTerm, nTerm, flags, pSeg, pIter);

  213220.           }

  213221.         }

  213222.       }

  213223.     }else{

  213224.       pLvl = &pStruct->aLevel[iLevel];

  213225.       for(iSeg=nSeg-1; iSeg>=0; iSeg--){

  213226.         fts5SegIterInit(p, &pLvl->aSeg[iSeg], &pNew->aSeg[iIter++]);

  213227.       }

  213228.     }

  213229.     assert( iIter==nSeg );

  213230.   }

  213231. 

  213232.   /* If the above was successful, each component iterators now points 

  213233.   ** to the first entry in its segment. In this case initialize the 

  213234.   ** aFirst[] array. Or, if an error has occurred, free the iterator

  213235.   ** object and set the output variable to NULL.  */

  213236.   if( p->rc==SQLITE_OK ){

  213237.     for(iIter=pNew->nSeg-1; iIter>0; iIter--){

  213238.       int iEq;

  213239.       if( (iEq = fts5MultiIterDoCompare(pNew, iIter)) ){

  213240.         Fts5SegIter *pSeg = &pNew->aSeg[iEq];

  213241.         if( p->rc==SQLITE_OK ) pSeg->xNext(p, pSeg, 0);

  213242.         fts5MultiIterAdvanced(p, pNew, iEq, iIter);

  213243.       }

  213244.     }

  213245.     fts5MultiIterSetEof(pNew);

  213246.     fts5AssertMultiIterSetup(p, pNew);

  213247. 

  213248.     if( pNew->bSkipEmpty && fts5MultiIterIsEmpty(p, pNew) ){

  213249.       fts5MultiIterNext(p, pNew, 0, 0);

  213250.     }else if( pNew->base.bEof==0 ){

  213251.       Fts5SegIter *pSeg = &pNew->aSeg[pNew->aFirst[1].iFirst];

  213252.       pNew->xSetOutputs(pNew, pSeg);

  213253.     }

  213254. 

  213255.   }else{

  213256.     fts5MultiIterFree(pNew);

  213257.     *ppOut = 0;

  213258.   }

  213259. }

  213260. 

  213261. /*

  213262. ** Create an Fts5Iter that iterates through the doclist provided

  213263. ** as the second argument.

  213264. */

  213265. static void fts5MultiIterNew2(

  213266.   Fts5Index *p,                   /* FTS5 backend to iterate within */

  213267.   Fts5Data *pData,                /* Doclist to iterate through */

  213268.   int bDesc,                      /* True for descending rowid order */

  213269.   Fts5Iter **ppOut                /* New object */

  213270. ){

  213271.   Fts5Iter *pNew;

  213272.   pNew = fts5MultiIterAlloc(p, 2);

  213273.   if( pNew ){

  213274.     Fts5SegIter *pIter = &pNew->aSeg[1];

  213275. 

  213276.     pIter->flags = FTS5_SEGITER_ONETERM;

  213277.     if( pData->szLeaf>0 ){

  213278.       pIter->pLeaf = pData;

  213279.       pIter->iLeafOffset = fts5GetVarint(pData->p, (u64*)&pIter->iRowid);

  213280.       pIter->iEndofDoclist = pData->nn;

  213281.       pNew->aFirst[1].iFirst = 1;

  213282.       if( bDesc ){

  213283.         pNew->bRev = 1;

  213284.         pIter->flags |= FTS5_SEGITER_REVERSE;

  213285.         fts5SegIterReverseInitPage(p, pIter);

  213286.       }else{

  213287.         fts5SegIterLoadNPos(p, pIter);

  213288.       }

  213289.       pData = 0;

  213290.     }else{

  213291.       pNew->base.bEof = 1;

  213292.     }

  213293.     fts5SegIterSetNext(p, pIter);

  213294. 

  213295.     *ppOut = pNew;

  213296.   }

  213297. 

  213298.   fts5DataRelease(pData);

  213299. }

  213300. 

  213301. /*

  213302. ** Return true if the iterator is at EOF or if an error has occurred. 

  213303. ** False otherwise.

  213304. */

  213305. static int fts5MultiIterEof(Fts5Index *p, Fts5Iter *pIter){

  213306.   assert( p->rc 

  213307.       || (pIter->aSeg[ pIter->aFirst[1].iFirst ].pLeaf==0)==pIter->base.bEof 

  213308.   );

  213309.   return (p->rc || pIter->base.bEof);

  213310. }

  213311. 

  213312. /*

  213313. ** Return the rowid of the entry that the iterator currently points

  213314. ** to. If the iterator points to EOF when this function is called the

  213315. ** results are undefined.

  213316. */

  213317. static i64 fts5MultiIterRowid(Fts5Iter *pIter){

  213318.   assert( pIter->aSeg[ pIter->aFirst[1].iFirst ].pLeaf );

  213319.   return pIter->aSeg[ pIter->aFirst[1].iFirst ].iRowid;

  213320. }

  213321. 

  213322. /*

  213323. ** Move the iterator to the next entry at or following iMatch.

  213324. */

  213325. static void fts5MultiIterNextFrom(

  213326.   Fts5Index *p, 

  213327.   Fts5Iter *pIter, 

  213328.   i64 iMatch

  213329. ){

  213330.   while( 1 ){

  213331.     i64 iRowid;

  213332.     fts5MultiIterNext(p, pIter, 1, iMatch);

  213333.     if( fts5MultiIterEof(p, pIter) ) break;

  213334.     iRowid = fts5MultiIterRowid(pIter);

  213335.     if( pIter->bRev==0 && iRowid>=iMatch ) break;

  213336.     if( pIter->bRev!=0 && iRowid<=iMatch ) break;

  213337.   }

  213338. }

  213339. 

  213340. /*

  213341. ** Return a pointer to a buffer containing the term associated with the 

  213342. ** entry that the iterator currently points to.

  213343. */

  213344. static const u8 *fts5MultiIterTerm(Fts5Iter *pIter, int *pn){

  213345.   Fts5SegIter *p = &pIter->aSeg[ pIter->aFirst[1].iFirst ];

  213346.   *pn = p->term.n;

  213347.   return p->term.p;

  213348. }

  213349. 

  213350. /*

  213351. ** Allocate a new segment-id for the structure pStruct. The new segment

  213352. ** id must be between 1 and 65335 inclusive, and must not be used by 

  213353. ** any currently existing segment. If a free segment id cannot be found,

  213354. ** SQLITE_FULL is returned.

  213355. **

  213356. ** If an error has already occurred, this function is a no-op. 0 is 

  213357. ** returned in this case.

  213358. */

  213359. static int fts5AllocateSegid(Fts5Index *p, Fts5Structure *pStruct){

  213360.   int iSegid = 0;

  213361. 

  213362.   if( p->rc==SQLITE_OK ){

  213363.     if( pStruct->nSegment>=FTS5_MAX_SEGMENT ){

  213364.       p->rc = SQLITE_FULL;

  213365.     }else{

  213366.       /* FTS5_MAX_SEGMENT is currently defined as 2000. So the following

  213367.       ** array is 63 elements, or 252 bytes, in size.  */

  213368.       u32 aUsed[(FTS5_MAX_SEGMENT+31) / 32];

  213369.       int iLvl, iSeg;

  213370.       int i;

  213371.       u32 mask;

  213372.       memset(aUsed, 0, sizeof(aUsed));

  213373.       for(iLvl=0; iLvl<pStruct->nLevel; iLvl++){

  213374.         for(iSeg=0; iSeg<pStruct->aLevel[iLvl].nSeg; iSeg++){

  213375.           int iId = pStruct->aLevel[iLvl].aSeg[iSeg].iSegid;

  213376.           if( iId<=FTS5_MAX_SEGMENT && iId>0 ){

  213377.             aUsed[(iId-1) / 32] |= (u32)1 << ((iId-1) % 32);

  213378.           }

  213379.         }

  213380.       }

  213381. 

  213382.       for(i=0; aUsed[i]==0xFFFFFFFF; i++);

  213383.       mask = aUsed[i];

  213384.       for(iSegid=0; mask & ((u32)1 << iSegid); iSegid++);

  213385.       iSegid += 1 + i*32;

  213386. 

  213387. #ifdef SQLITE_DEBUG

  213388.       for(iLvl=0; iLvl<pStruct->nLevel; iLvl++){

  213389.         for(iSeg=0; iSeg<pStruct->aLevel[iLvl].nSeg; iSeg++){

  213390.           assert_nc( iSegid!=pStruct->aLevel[iLvl].aSeg[iSeg].iSegid );

  213391.         }

  213392.       }

  213393.       assert_nc( iSegid>0 && iSegid<=FTS5_MAX_SEGMENT );

  213394. 

  213395.       {

  213396.         sqlite3_stmt *pIdxSelect = fts5IdxSelectStmt(p);

  213397.         if( p->rc==SQLITE_OK ){

  213398.           u8 aBlob[2] = {0xff, 0xff};

  213399.           sqlite3_bind_int(pIdxSelect, 1, iSegid);

  213400.           sqlite3_bind_blob(pIdxSelect, 2, aBlob, 2, SQLITE_STATIC);

  213401.           assert_nc( sqlite3_step(pIdxSelect)!=SQLITE_ROW );

  213402.           p->rc = sqlite3_reset(pIdxSelect);

  213403.           sqlite3_bind_null(pIdxSelect, 2);

  213404.         }

  213405.       }

  213406. #endif

  213407.     }

  213408.   }

  213409. 

  213410.   return iSegid;

  213411. }

  213412. 

  213413. /*

  213414. ** Discard all data currently cached in the hash-tables.

  213415. */

  213416. static void fts5IndexDiscardData(Fts5Index *p){

  213417.   assert( p->pHash || p->nPendingData==0 );

  213418.   if( p->pHash ){

  213419.     sqlite3Fts5HashClear(p->pHash);

  213420.     p->nPendingData = 0;

  213421.   }

  213422. }

  213423. 

  213424. /*

  213425. ** Return the size of the prefix, in bytes, that buffer 

  213426. ** (pNew/<length-unknown>) shares with buffer (pOld/nOld).

  213427. **

  213428. ** Buffer (pNew/<length-unknown>) is guaranteed to be greater 

  213429. ** than buffer (pOld/nOld).

  213430. */

  213431. static int fts5PrefixCompress(int nOld, const u8 *pOld, const u8 *pNew){

  213432.   int i;

  213433.   for(i=0; i<nOld; i++){

  213434.     if( pOld[i]!=pNew[i] ) break;

  213435.   }

  213436.   return i;

  213437. }

  213438. 

  213439. static void fts5WriteDlidxClear(

  213440.   Fts5Index *p, 

  213441.   Fts5SegWriter *pWriter,

  213442.   int bFlush                      /* If true, write dlidx to disk */

  213443. ){

  213444.   int i;

  213445.   assert( bFlush==0 || (pWriter->nDlidx>0 && pWriter->aDlidx[0].buf.n>0) );

  213446.   for(i=0; i<pWriter->nDlidx; i++){

  213447.     Fts5DlidxWriter *pDlidx = &pWriter->aDlidx[i];

  213448.     if( pDlidx->buf.n==0 ) break;

  213449.     if( bFlush ){

  213450.       assert( pDlidx->pgno!=0 );

  213451.       fts5DataWrite(p, 

  213452.           FTS5_DLIDX_ROWID(pWriter->iSegid, i, pDlidx->pgno),

  213453.           pDlidx->buf.p, pDlidx->buf.n

  213454.       );

  213455.     }

  213456.     sqlite3Fts5BufferZero(&pDlidx->buf);

  213457.     pDlidx->bPrevValid = 0;

  213458.   }

  213459. }

  213460. 

  213461. /*

  213462. ** Grow the pWriter->aDlidx[] array to at least nLvl elements in size.

  213463. ** Any new array elements are zeroed before returning.

  213464. */

  213465. static int fts5WriteDlidxGrow(

  213466.   Fts5Index *p,

  213467.   Fts5SegWriter *pWriter,

  213468.   int nLvl

  213469. ){

  213470.   if( p->rc==SQLITE_OK && nLvl>=pWriter->nDlidx ){

  213471.     Fts5DlidxWriter *aDlidx = (Fts5DlidxWriter*)sqlite3_realloc64(

  213472.         pWriter->aDlidx, sizeof(Fts5DlidxWriter) * nLvl

  213473.     );

  213474.     if( aDlidx==0 ){

  213475.       p->rc = SQLITE_NOMEM;

  213476.     }else{

  213477.       size_t nByte = sizeof(Fts5DlidxWriter) * (nLvl - pWriter->nDlidx);

  213478.       memset(&aDlidx[pWriter->nDlidx], 0, nByte);

  213479.       pWriter->aDlidx = aDlidx;

  213480.       pWriter->nDlidx = nLvl;

  213481.     }

  213482.   }

  213483.   return p->rc;

  213484. }

  213485. 

  213486. /*

  213487. ** If the current doclist-index accumulating in pWriter->aDlidx[] is large

  213488. ** enough, flush it to disk and return 1. Otherwise discard it and return

  213489. ** zero.

  213490. */

  213491. static int fts5WriteFlushDlidx(Fts5Index *p, Fts5SegWriter *pWriter){

  213492.   int bFlag = 0;

  213493. 

  213494.   /* If there were FTS5_MIN_DLIDX_SIZE or more empty leaf pages written

  213495.   ** to the database, also write the doclist-index to disk.  */

  213496.   if( pWriter->aDlidx[0].buf.n>0 && pWriter->nEmpty>=FTS5_MIN_DLIDX_SIZE ){

  213497.     bFlag = 1;

  213498.   }

  213499.   fts5WriteDlidxClear(p, pWriter, bFlag);

  213500.   pWriter->nEmpty = 0;

  213501.   return bFlag;

  213502. }

  213503. 

  213504. /*

  213505. ** This function is called whenever processing of the doclist for the 

  213506. ** last term on leaf page (pWriter->iBtPage) is completed. 

  213507. **

  213508. ** The doclist-index for that term is currently stored in-memory within the

  213509. ** Fts5SegWriter.aDlidx[] array. If it is large enough, this function

  213510. ** writes it out to disk. Or, if it is too small to bother with, discards

  213511. ** it.

  213512. **

  213513. ** Fts5SegWriter.btterm currently contains the first term on page iBtPage.

  213514. */

  213515. static void fts5WriteFlushBtree(Fts5Index *p, Fts5SegWriter *pWriter){

  213516.   int bFlag;

  213517. 

  213518.   assert( pWriter->iBtPage || pWriter->nEmpty==0 );

  213519.   if( pWriter->iBtPage==0 ) return;

  213520.   bFlag = fts5WriteFlushDlidx(p, pWriter);

  213521. 

  213522.   if( p->rc==SQLITE_OK ){

  213523.     const char *z = (pWriter->btterm.n>0?(const char*)pWriter->btterm.p:"");

  213524.     /* The following was already done in fts5WriteInit(): */

  213525.     /* sqlite3_bind_int(p->pIdxWriter, 1, pWriter->iSegid); */

  213526.     sqlite3_bind_blob(p->pIdxWriter, 2, z, pWriter->btterm.n, SQLITE_STATIC);

  213527.     sqlite3_bind_int64(p->pIdxWriter, 3, bFlag + ((i64)pWriter->iBtPage<<1));

  213528.     sqlite3_step(p->pIdxWriter);

  213529.     p->rc = sqlite3_reset(p->pIdxWriter);

  213530.     sqlite3_bind_null(p->pIdxWriter, 2);

  213531.   }

  213532.   pWriter->iBtPage = 0;

  213533. }

  213534. 

  213535. /*

  213536. ** This is called once for each leaf page except the first that contains

  213537. ** at least one term. Argument (nTerm/pTerm) is the split-key - a term that

  213538. ** is larger than all terms written to earlier leaves, and equal to or

  213539. ** smaller than the first term on the new leaf.

  213540. **

  213541. ** If an error occurs, an error code is left in Fts5Index.rc. If an error

  213542. ** has already occurred when this function is called, it is a no-op.

  213543. */

  213544. static void fts5WriteBtreeTerm(

  213545.   Fts5Index *p,                   /* FTS5 backend object */

  213546.   Fts5SegWriter *pWriter,         /* Writer object */

  213547.   int nTerm, const u8 *pTerm      /* First term on new page */

  213548. ){

  213549.   fts5WriteFlushBtree(p, pWriter);

  213550.   if( p->rc==SQLITE_OK ){

  213551.     fts5BufferSet(&p->rc, &pWriter->btterm, nTerm, pTerm);

  213552.     pWriter->iBtPage = pWriter->writer.pgno;

  213553.   }

  213554. }

  213555. 

  213556. /*

  213557. ** This function is called when flushing a leaf page that contains no

  213558. ** terms at all to disk.

  213559. */

  213560. static void fts5WriteBtreeNoTerm(

  213561.   Fts5Index *p,                   /* FTS5 backend object */

  213562.   Fts5SegWriter *pWriter          /* Writer object */

  213563. ){

  213564.   /* If there were no rowids on the leaf page either and the doclist-index

  213565.   ** has already been started, append an 0x00 byte to it.  */

  213566.   if( pWriter->bFirstRowidInPage && pWriter->aDlidx[0].buf.n>0 ){

  213567.     Fts5DlidxWriter *pDlidx = &pWriter->aDlidx[0];

  213568.     assert( pDlidx->bPrevValid );

  213569.     sqlite3Fts5BufferAppendVarint(&p->rc, &pDlidx->buf, 0);

  213570.   }

  213571. 

  213572.   /* Increment the "number of sequential leaves without a term" counter. */

  213573.   pWriter->nEmpty++;

  213574. }

  213575. 

  213576. static i64 fts5DlidxExtractFirstRowid(Fts5Buffer *pBuf){

  213577.   i64 iRowid;

  213578.   int iOff;

  213579. 

  213580.   iOff = 1 + fts5GetVarint(&pBuf->p[1], (u64*)&iRowid);

  213581.   fts5GetVarint(&pBuf->p[iOff], (u64*)&iRowid);

  213582.   return iRowid;

  213583. }

  213584. 

  213585. /*

  213586. ** Rowid iRowid has just been appended to the current leaf page. It is the

  213587. ** first on the page. This function appends an appropriate entry to the current

  213588. ** doclist-index.

  213589. */

  213590. static void fts5WriteDlidxAppend(

  213591.   Fts5Index *p, 

  213592.   Fts5SegWriter *pWriter, 

  213593.   i64 iRowid

  213594. ){

  213595.   int i;

  213596.   int bDone = 0;

  213597. 

  213598.   for(i=0; p->rc==SQLITE_OK && bDone==0; i++){

  213599.     i64 iVal;

  213600.     Fts5DlidxWriter *pDlidx = &pWriter->aDlidx[i];

  213601. 

  213602.     if( pDlidx->buf.n>=p->pConfig->pgsz ){

  213603.       /* The current doclist-index page is full. Write it to disk and push

  213604.       ** a copy of iRowid (which will become the first rowid on the next

  213605.       ** doclist-index leaf page) up into the next level of the b-tree 

  213606.       ** hierarchy. If the node being flushed is currently the root node,

  213607.       ** also push its first rowid upwards. */

  213608.       pDlidx->buf.p[0] = 0x01;    /* Not the root node */

  213609.       fts5DataWrite(p, 

  213610.           FTS5_DLIDX_ROWID(pWriter->iSegid, i, pDlidx->pgno),

  213611.           pDlidx->buf.p, pDlidx->buf.n

  213612.       );

  213613.       fts5WriteDlidxGrow(p, pWriter, i+2);

  213614.       pDlidx = &pWriter->aDlidx[i];

  213615.       if( p->rc==SQLITE_OK && pDlidx[1].buf.n==0 ){

  213616.         i64 iFirst = fts5DlidxExtractFirstRowid(&pDlidx->buf);

  213617. 

  213618.         /* This was the root node. Push its first rowid up to the new root. */

  213619.         pDlidx[1].pgno = pDlidx->pgno;

  213620.         sqlite3Fts5BufferAppendVarint(&p->rc, &pDlidx[1].buf, 0);

  213621.         sqlite3Fts5BufferAppendVarint(&p->rc, &pDlidx[1].buf, pDlidx->pgno);

  213622.         sqlite3Fts5BufferAppendVarint(&p->rc, &pDlidx[1].buf, iFirst);

  213623.         pDlidx[1].bPrevValid = 1;

  213624.         pDlidx[1].iPrev = iFirst;

  213625.       }

  213626. 

  213627.       sqlite3Fts5BufferZero(&pDlidx->buf);

  213628.       pDlidx->bPrevValid = 0;

  213629.       pDlidx->pgno++;

  213630.     }else{

  213631.       bDone = 1;

  213632.     }

  213633. 

  213634.     if( pDlidx->bPrevValid ){

  213635.       iVal = iRowid - pDlidx->iPrev;

  213636.     }else{

  213637.       i64 iPgno = (i==0 ? pWriter->writer.pgno : pDlidx[-1].pgno);

  213638.       assert( pDlidx->buf.n==0 );

  213639.       sqlite3Fts5BufferAppendVarint(&p->rc, &pDlidx->buf, !bDone);

  213640.       sqlite3Fts5BufferAppendVarint(&p->rc, &pDlidx->buf, iPgno);

  213641.       iVal = iRowid;

  213642.     }

  213643. 

  213644.     sqlite3Fts5BufferAppendVarint(&p->rc, &pDlidx->buf, iVal);

  213645.     pDlidx->bPrevValid = 1;

  213646.     pDlidx->iPrev = iRowid;

  213647.   }

  213648. }

  213649. 

  213650. static void fts5WriteFlushLeaf(Fts5Index *p, Fts5SegWriter *pWriter){

  213651.   static const u8 zero[] = { 0x00, 0x00, 0x00, 0x00 };

  213652.   Fts5PageWriter *pPage = &pWriter->writer;

  213653.   i64 iRowid;

  213654. 

  213655.   assert( (pPage->pgidx.n==0)==(pWriter->bFirstTermInPage) );

  213656. 

  213657.   /* Set the szLeaf header field. */

  213658.   assert( 0==fts5GetU16(&pPage->buf.p[2]) );

  213659.   fts5PutU16(&pPage->buf.p[2], (u16)pPage->buf.n);

  213660. 

  213661.   if( pWriter->bFirstTermInPage ){

  213662.     /* No term was written to this page. */

  213663.     assert( pPage->pgidx.n==0 );

  213664.     fts5WriteBtreeNoTerm(p, pWriter);

  213665.   }else{

  213666.     /* Append the pgidx to the page buffer. Set the szLeaf header field. */

  213667.     fts5BufferAppendBlob(&p->rc, &pPage->buf, pPage->pgidx.n, pPage->pgidx.p);

  213668.   }

  213669. 

  213670.   /* Write the page out to disk */

  213671.   iRowid = FTS5_SEGMENT_ROWID(pWriter->iSegid, pPage->pgno);

  213672.   fts5DataWrite(p, iRowid, pPage->buf.p, pPage->buf.n);

  213673. 

  213674.   /* Initialize the next page. */

  213675.   fts5BufferZero(&pPage->buf);

  213676.   fts5BufferZero(&pPage->pgidx);

  213677.   fts5BufferAppendBlob(&p->rc, &pPage->buf, 4, zero);

  213678.   pPage->iPrevPgidx = 0;

  213679.   pPage->pgno++;

  213680. 

  213681.   /* Increase the leaves written counter */

  213682.   pWriter->nLeafWritten++;

  213683. 

  213684.   /* The new leaf holds no terms or rowids */

  213685.   pWriter->bFirstTermInPage = 1;

  213686.   pWriter->bFirstRowidInPage = 1;

  213687. }

  213688. 

  213689. /*

  213690. ** Append term pTerm/nTerm to the segment being written by the writer passed

  213691. ** as the second argument.

  213692. **

  213693. ** If an error occurs, set the Fts5Index.rc error code. If an error has 

  213694. ** already occurred, this function is a no-op.

  213695. */

  213696. static void fts5WriteAppendTerm(

  213697.   Fts5Index *p, 

  213698.   Fts5SegWriter *pWriter,

  213699.   int nTerm, const u8 *pTerm 

  213700. ){

  213701.   int nPrefix;                    /* Bytes of prefix compression for term */

  213702.   Fts5PageWriter *pPage = &pWriter->writer;

  213703.   Fts5Buffer *pPgidx = &pWriter->writer.pgidx;

  213704.   int nMin = MIN(pPage->term.n, nTerm);

  213705. 

  213706.   assert( p->rc==SQLITE_OK );

  213707.   assert( pPage->buf.n>=4 );

  213708.   assert( pPage->buf.n>4 || pWriter->bFirstTermInPage );

  213709. 

  213710.   /* If the current leaf page is full, flush it to disk. */

  213711.   if( (pPage->buf.n + pPgidx->n + nTerm + 2)>=p->pConfig->pgsz ){

  213712.     if( pPage->buf.n>4 ){

  213713.       fts5WriteFlushLeaf(p, pWriter);

  213714.       if( p->rc!=SQLITE_OK ) return;

  213715.     }

  213716.     fts5BufferGrow(&p->rc, &pPage->buf, nTerm+FTS5_DATA_PADDING);

  213717.   }

  213718.   

  213719.   /* TODO1: Updating pgidx here. */

  213720.   pPgidx->n += sqlite3Fts5PutVarint(

  213721.       &pPgidx->p[pPgidx->n], pPage->buf.n - pPage->iPrevPgidx

  213722.   );

  213723.   pPage->iPrevPgidx = pPage->buf.n;

  213724. #if 0

  213725.   fts5PutU16(&pPgidx->p[pPgidx->n], pPage->buf.n);

  213726.   pPgidx->n += 2;

  213727. #endif

  213728. 

  213729.   if( pWriter->bFirstTermInPage ){

  213730.     nPrefix = 0;

  213731.     if( pPage->pgno!=1 ){

  213732.       /* This is the first term on a leaf that is not the leftmost leaf in

  213733.       ** the segment b-tree. In this case it is necessary to add a term to

  213734.       ** the b-tree hierarchy that is (a) larger than the largest term 

  213735.       ** already written to the segment and (b) smaller than or equal to

  213736.       ** this term. In other words, a prefix of (pTerm/nTerm) that is one

  213737.       ** byte longer than the longest prefix (pTerm/nTerm) shares with the

  213738.       ** previous term. 

  213739.       **

  213740.       ** Usually, the previous term is available in pPage->term. The exception

  213741.       ** is if this is the first term written in an incremental-merge step.

  213742.       ** In this case the previous term is not available, so just write a

  213743.       ** copy of (pTerm/nTerm) into the parent node. This is slightly

  213744.       ** inefficient, but still correct.  */

  213745.       int n = nTerm;

  213746.       if( pPage->term.n ){

  213747.         n = 1 + fts5PrefixCompress(nMin, pPage->term.p, pTerm);

  213748.       }

  213749.       fts5WriteBtreeTerm(p, pWriter, n, pTerm);

  213750.       if( p->rc!=SQLITE_OK ) return;

  213751.       pPage = &pWriter->writer;

  213752.     }

  213753.   }else{

  213754.     nPrefix = fts5PrefixCompress(nMin, pPage->term.p, pTerm);

  213755.     fts5BufferAppendVarint(&p->rc, &pPage->buf, nPrefix);

  213756.   }

  213757. 

  213758.   /* Append the number of bytes of new data, then the term data itself

  213759.   ** to the page. */

  213760.   fts5BufferAppendVarint(&p->rc, &pPage->buf, nTerm - nPrefix);

  213761.   fts5BufferAppendBlob(&p->rc, &pPage->buf, nTerm - nPrefix, &pTerm[nPrefix]);

  213762. 

  213763.   /* Update the Fts5PageWriter.term field. */

  213764.   fts5BufferSet(&p->rc, &pPage->term, nTerm, pTerm);

  213765.   pWriter->bFirstTermInPage = 0;

  213766. 

  213767.   pWriter->bFirstRowidInPage = 0;

  213768.   pWriter->bFirstRowidInDoclist = 1;

  213769. 

  213770.   assert( p->rc || (pWriter->nDlidx>0 && pWriter->aDlidx[0].buf.n==0) );

  213771.   pWriter->aDlidx[0].pgno = pPage->pgno;

  213772. }

  213773. 

  213774. /*

  213775. ** Append a rowid and position-list size field to the writers output. 

  213776. */

  213777. static void fts5WriteAppendRowid(

  213778.   Fts5Index *p, 

  213779.   Fts5SegWriter *pWriter,

  213780.   i64 iRowid

  213781. ){

  213782.   if( p->rc==SQLITE_OK ){

  213783.     Fts5PageWriter *pPage = &pWriter->writer;

  213784. 

  213785.     if( (pPage->buf.n + pPage->pgidx.n)>=p->pConfig->pgsz ){

  213786.       fts5WriteFlushLeaf(p, pWriter);

  213787.     }

  213788. 

  213789.     /* If this is to be the first rowid written to the page, set the 

  213790.     ** rowid-pointer in the page-header. Also append a value to the dlidx

  213791.     ** buffer, in case a doclist-index is required.  */

  213792.     if( pWriter->bFirstRowidInPage ){

  213793.       fts5PutU16(pPage->buf.p, (u16)pPage->buf.n);

  213794.       fts5WriteDlidxAppend(p, pWriter, iRowid);

  213795.     }

  213796. 

  213797.     /* Write the rowid. */

  213798.     if( pWriter->bFirstRowidInDoclist || pWriter->bFirstRowidInPage ){

  213799.       fts5BufferAppendVarint(&p->rc, &pPage->buf, iRowid);

  213800.     }else{

  213801.       assert_nc( p->rc || iRowid>pWriter->iPrevRowid );

  213802.       fts5BufferAppendVarint(&p->rc, &pPage->buf, iRowid - pWriter->iPrevRowid);

  213803.     }

  213804.     pWriter->iPrevRowid = iRowid;

  213805.     pWriter->bFirstRowidInDoclist = 0;

  213806.     pWriter->bFirstRowidInPage = 0;

  213807.   }

  213808. }

  213809. 

  213810. static void fts5WriteAppendPoslistData(

  213811.   Fts5Index *p, 

  213812.   Fts5SegWriter *pWriter, 

  213813.   const u8 *aData, 

  213814.   int nData

  213815. ){

  213816.   Fts5PageWriter *pPage = &pWriter->writer;

  213817.   const u8 *a = aData;

  213818.   int n = nData;

  213819.   

  213820.   assert( p->pConfig->pgsz>0 );

  213821.   while( p->rc==SQLITE_OK 

  213822.      && (pPage->buf.n + pPage->pgidx.n + n)>=p->pConfig->pgsz 

  213823.   ){

  213824.     int nReq = p->pConfig->pgsz - pPage->buf.n - pPage->pgidx.n;

  213825.     int nCopy = 0;

  213826.     while( nCopy<nReq ){

  213827.       i64 dummy;

  213828.       nCopy += fts5GetVarint(&a[nCopy], (u64*)&dummy);

  213829.     }

  213830.     fts5BufferAppendBlob(&p->rc, &pPage->buf, nCopy, a);

  213831.     a += nCopy;

  213832.     n -= nCopy;

  213833.     fts5WriteFlushLeaf(p, pWriter);

  213834.   }

  213835.   if( n>0 ){

  213836.     fts5BufferAppendBlob(&p->rc, &pPage->buf, n, a);

  213837.   }

  213838. }

  213839. 

  213840. /*

  213841. ** Flush any data cached by the writer object to the database. Free any

  213842. ** allocations associated with the writer.

  213843. */

  213844. static void fts5WriteFinish(

  213845.   Fts5Index *p, 

  213846.   Fts5SegWriter *pWriter,         /* Writer object */

  213847.   int *pnLeaf                     /* OUT: Number of leaf pages in b-tree */

  213848. ){

  213849.   int i;

  213850.   Fts5PageWriter *pLeaf = &pWriter->writer;

  213851.   if( p->rc==SQLITE_OK ){

  213852.     assert( pLeaf->pgno>=1 );

  213853.     if( pLeaf->buf.n>4 ){

  213854.       fts5WriteFlushLeaf(p, pWriter);

  213855.     }

  213856.     *pnLeaf = pLeaf->pgno-1;

  213857.     if( pLeaf->pgno>1 ){

  213858.       fts5WriteFlushBtree(p, pWriter);

  213859.     }

  213860.   }

  213861.   fts5BufferFree(&pLeaf->term);

  213862.   fts5BufferFree(&pLeaf->buf);

  213863.   fts5BufferFree(&pLeaf->pgidx);

  213864.   fts5BufferFree(&pWriter->btterm);

  213865. 

  213866.   for(i=0; i<pWriter->nDlidx; i++){

  213867.     sqlite3Fts5BufferFree(&pWriter->aDlidx[i].buf);

  213868.   }

  213869.   sqlite3_free(pWriter->aDlidx);

  213870. }

  213871. 

  213872. static void fts5WriteInit(

  213873.   Fts5Index *p, 

  213874.   Fts5SegWriter *pWriter, 

  213875.   int iSegid

  213876. ){

  213877.   const int nBuffer = p->pConfig->pgsz + FTS5_DATA_PADDING;

  213878. 

  213879.   memset(pWriter, 0, sizeof(Fts5SegWriter));

  213880.   pWriter->iSegid = iSegid;

  213881. 

  213882.   fts5WriteDlidxGrow(p, pWriter, 1);

  213883.   pWriter->writer.pgno = 1;

  213884.   pWriter->bFirstTermInPage = 1;

  213885.   pWriter->iBtPage = 1;

  213886. 

  213887.   assert( pWriter->writer.buf.n==0 );

  213888.   assert( pWriter->writer.pgidx.n==0 );

  213889. 

  213890.   /* Grow the two buffers to pgsz + padding bytes in size. */

  213891.   sqlite3Fts5BufferSize(&p->rc, &pWriter->writer.pgidx, nBuffer);

  213892.   sqlite3Fts5BufferSize(&p->rc, &pWriter->writer.buf, nBuffer);

  213893. 

  213894.   if( p->pIdxWriter==0 ){

  213895.     Fts5Config *pConfig = p->pConfig;

  213896.     fts5IndexPrepareStmt(p, &p->pIdxWriter, sqlite3_mprintf(

  213897.           "INSERT INTO '%q'.'%q_idx'(segid,term,pgno) VALUES(?,?,?)", 

  213898.           pConfig->zDb, pConfig->zName

  213899.     ));

  213900.   }

  213901. 

  213902.   if( p->rc==SQLITE_OK ){

  213903.     /* Initialize the 4-byte leaf-page header to 0x00. */

  213904.     memset(pWriter->writer.buf.p, 0, 4);

  213905.     pWriter->writer.buf.n = 4;

  213906. 

  213907.     /* Bind the current output segment id to the index-writer. This is an

  213908.     ** optimization over binding the same value over and over as rows are

  213909.     ** inserted into %_idx by the current writer.  */

  213910.     sqlite3_bind_int(p->pIdxWriter, 1, pWriter->iSegid);

  213911.   }

  213912. }

  213913. 

  213914. /*

  213915. ** Iterator pIter was used to iterate through the input segments of on an

  213916. ** incremental merge operation. This function is called if the incremental

  213917. ** merge step has finished but the input has not been completely exhausted.

  213918. */

  213919. static void fts5TrimSegments(Fts5Index *p, Fts5Iter *pIter){

  213920.   int i;

  213921.   Fts5Buffer buf;

  213922.   memset(&buf, 0, sizeof(Fts5Buffer));

  213923.   for(i=0; i<pIter->nSeg && p->rc==SQLITE_OK; i++){

  213924.     Fts5SegIter *pSeg = &pIter->aSeg[i];

  213925.     if( pSeg->pSeg==0 ){

  213926.       /* no-op */

  213927.     }else if( pSeg->pLeaf==0 ){

  213928.       /* All keys from this input segment have been transfered to the output.

  213929.       ** Set both the first and last page-numbers to 0 to indicate that the

  213930.       ** segment is now empty. */

  213931.       pSeg->pSeg->pgnoLast = 0;

  213932.       pSeg->pSeg->pgnoFirst = 0;

  213933.     }else{

  213934.       int iOff = pSeg->iTermLeafOffset;     /* Offset on new first leaf page */

  213935.       i64 iLeafRowid;

  213936.       Fts5Data *pData;

  213937.       int iId = pSeg->pSeg->iSegid;

  213938.       u8 aHdr[4] = {0x00, 0x00, 0x00, 0x00};

  213939. 

  213940.       iLeafRowid = FTS5_SEGMENT_ROWID(iId, pSeg->iTermLeafPgno);

  213941.       pData = fts5LeafRead(p, iLeafRowid);

  213942.       if( pData ){

  213943.         if( iOff>pData->szLeaf ){

  213944.           /* This can occur if the pages that the segments occupy overlap - if

  213945.           ** a single page has been assigned to more than one segment. In

  213946.           ** this case a prior iteration of this loop may have corrupted the

  213947.           ** segment currently being trimmed.  */

  213948.           p->rc = FTS5_CORRUPT;

  213949.         }else{

  213950.           fts5BufferZero(&buf);

  213951.           fts5BufferGrow(&p->rc, &buf, pData->nn);

  213952.           fts5BufferAppendBlob(&p->rc, &buf, sizeof(aHdr), aHdr);

  213953.           fts5BufferAppendVarint(&p->rc, &buf, pSeg->term.n);

  213954.           fts5BufferAppendBlob(&p->rc, &buf, pSeg->term.n, pSeg->term.p);

  213955.           fts5BufferAppendBlob(&p->rc, &buf, pData->szLeaf-iOff,&pData->p[iOff]);

  213956.           if( p->rc==SQLITE_OK ){

  213957.             /* Set the szLeaf field */

  213958.             fts5PutU16(&buf.p[2], (u16)buf.n);

  213959.           }

  213960. 

  213961.           /* Set up the new page-index array */

  213962.           fts5BufferAppendVarint(&p->rc, &buf, 4);

  213963.           if( pSeg->iLeafPgno==pSeg->iTermLeafPgno 

  213964.            && pSeg->iEndofDoclist<pData->szLeaf

  213965.            && pSeg->iPgidxOff<=pData->nn

  213966.           ){

  213967.             int nDiff = pData->szLeaf - pSeg->iEndofDoclist;

  213968.             fts5BufferAppendVarint(&p->rc, &buf, buf.n - 1 - nDiff - 4);

  213969.             fts5BufferAppendBlob(&p->rc, &buf, 

  213970.                 pData->nn - pSeg->iPgidxOff, &pData->p[pSeg->iPgidxOff]

  213971.             );

  213972.           }

  213973. 

  213974.           pSeg->pSeg->pgnoFirst = pSeg->iTermLeafPgno;

  213975.           fts5DataDelete(p, FTS5_SEGMENT_ROWID(iId, 1), iLeafRowid);

  213976.           fts5DataWrite(p, iLeafRowid, buf.p, buf.n);

  213977.         }

  213978.         fts5DataRelease(pData);

  213979.       }

  213980.     }

  213981.   }

  213982.   fts5BufferFree(&buf);

  213983. }

  213984. 

  213985. static void fts5MergeChunkCallback(

  213986.   Fts5Index *p, 

  213987.   void *pCtx, 

  213988.   const u8 *pChunk, int nChunk

  213989. ){

  213990.   Fts5SegWriter *pWriter = (Fts5SegWriter*)pCtx;

  213991.   fts5WriteAppendPoslistData(p, pWriter, pChunk, nChunk);

  213992. }

  213993. 

  213994. /*

  213995. **

  213996. */

  213997. static void fts5IndexMergeLevel(

  213998.   Fts5Index *p,                   /* FTS5 backend object */

  213999.   Fts5Structure **ppStruct,       /* IN/OUT: Stucture of index */

  214000.   int iLvl,                       /* Level to read input from */

  214001.   int *pnRem                      /* Write up to this many output leaves */

  214002. ){

  214003.   Fts5Structure *pStruct = *ppStruct;

  214004.   Fts5StructureLevel *pLvl = &pStruct->aLevel[iLvl];

  214005.   Fts5StructureLevel *pLvlOut;

  214006.   Fts5Iter *pIter = 0;       /* Iterator to read input data */

  214007.   int nRem = pnRem ? *pnRem : 0;  /* Output leaf pages left to write */

  214008.   int nInput;                     /* Number of input segments */

  214009.   Fts5SegWriter writer;           /* Writer object */

  214010.   Fts5StructureSegment *pSeg;     /* Output segment */

  214011.   Fts5Buffer term;

  214012.   int bOldest;                    /* True if the output segment is the oldest */

  214013.   int eDetail = p->pConfig->eDetail;

  214014.   const int flags = FTS5INDEX_QUERY_NOOUTPUT;

  214015.   int bTermWritten = 0;           /* True if current term already output */

  214016. 

  214017.   assert( iLvl<pStruct->nLevel );

  214018.   assert( pLvl->nMerge<=pLvl->nSeg );

  214019. 

  214020.   memset(&writer, 0, sizeof(Fts5SegWriter));

  214021.   memset(&term, 0, sizeof(Fts5Buffer));

  214022.   if( pLvl->nMerge ){

  214023.     pLvlOut = &pStruct->aLevel[iLvl+1];

  214024.     assert( pLvlOut->nSeg>0 );

  214025.     nInput = pLvl->nMerge;

  214026.     pSeg = &pLvlOut->aSeg[pLvlOut->nSeg-1];

  214027. 

  214028.     fts5WriteInit(p, &writer, pSeg->iSegid);

  214029.     writer.writer.pgno = pSeg->pgnoLast+1;

  214030.     writer.iBtPage = 0;

  214031.   }else{

  214032.     int iSegid = fts5AllocateSegid(p, pStruct);

  214033. 

  214034.     /* Extend the Fts5Structure object as required to ensure the output

  214035.     ** segment exists. */

  214036.     if( iLvl==pStruct->nLevel-1 ){

  214037.       fts5StructureAddLevel(&p->rc, ppStruct);

  214038.       pStruct = *ppStruct;

  214039.     }

  214040.     fts5StructureExtendLevel(&p->rc, pStruct, iLvl+1, 1, 0);

  214041.     if( p->rc ) return;

  214042.     pLvl = &pStruct->aLevel[iLvl];

  214043.     pLvlOut = &pStruct->aLevel[iLvl+1];

  214044. 

  214045.     fts5WriteInit(p, &writer, iSegid);

  214046. 

  214047.     /* Add the new segment to the output level */

  214048.     pSeg = &pLvlOut->aSeg[pLvlOut->nSeg];

  214049.     pLvlOut->nSeg++;

  214050.     pSeg->pgnoFirst = 1;

  214051.     pSeg->iSegid = iSegid;

  214052.     pStruct->nSegment++;

  214053. 

  214054.     /* Read input from all segments in the input level */

  214055.     nInput = pLvl->nSeg;

  214056.   }

  214057.   bOldest = (pLvlOut->nSeg==1 && pStruct->nLevel==iLvl+2);

  214058. 

  214059.   assert( iLvl>=0 );

  214060.   for(fts5MultiIterNew(p, pStruct, flags, 0, 0, 0, iLvl, nInput, &pIter);

  214061.       fts5MultiIterEof(p, pIter)==0;

  214062.       fts5MultiIterNext(p, pIter, 0, 0)

  214063.   ){

  214064.     Fts5SegIter *pSegIter = &pIter->aSeg[ pIter->aFirst[1].iFirst ];

  214065.     int nPos;                     /* position-list size field value */

  214066.     int nTerm;

  214067.     const u8 *pTerm;

  214068. 

  214069.     pTerm = fts5MultiIterTerm(pIter, &nTerm);

  214070.     if( nTerm!=term.n || fts5Memcmp(pTerm, term.p, nTerm) ){

  214071.       if( pnRem && writer.nLeafWritten>nRem ){

  214072.         break;

  214073.       }

  214074.       fts5BufferSet(&p->rc, &term, nTerm, pTerm);

  214075.       bTermWritten =0;

  214076.     }

  214077. 

  214078.     /* Check for key annihilation. */

  214079.     if( pSegIter->nPos==0 && (bOldest || pSegIter->bDel==0) ) continue;

  214080. 

  214081.     if( p->rc==SQLITE_OK && bTermWritten==0 ){

  214082.       /* This is a new term. Append a term to the output segment. */

  214083.       fts5WriteAppendTerm(p, &writer, nTerm, pTerm);

  214084.       bTermWritten = 1;

  214085.     }

  214086. 

  214087.     /* Append the rowid to the output */

  214088.     /* WRITEPOSLISTSIZE */

  214089.     fts5WriteAppendRowid(p, &writer, fts5MultiIterRowid(pIter));

  214090. 

  214091.     if( eDetail==FTS5_DETAIL_NONE ){

  214092.       if( pSegIter->bDel ){

  214093.         fts5BufferAppendVarint(&p->rc, &writer.writer.buf, 0);

  214094.         if( pSegIter->nPos>0 ){

  214095.           fts5BufferAppendVarint(&p->rc, &writer.writer.buf, 0);

  214096.         }

  214097.       }

  214098.     }else{

  214099.       /* Append the position-list data to the output */

  214100.       nPos = pSegIter->nPos*2 + pSegIter->bDel;

  214101.       fts5BufferAppendVarint(&p->rc, &writer.writer.buf, nPos);

  214102.       fts5ChunkIterate(p, pSegIter, (void*)&writer, fts5MergeChunkCallback);

  214103.     }

  214104.   }

  214105. 

  214106.   /* Flush the last leaf page to disk. Set the output segment b-tree height

  214107.   ** and last leaf page number at the same time.  */

  214108.   fts5WriteFinish(p, &writer, &pSeg->pgnoLast);

  214109. 

  214110.   if( fts5MultiIterEof(p, pIter) ){

  214111.     int i;

  214112. 

  214113.     /* Remove the redundant segments from the %_data table */

  214114.     for(i=0; i<nInput; i++){

  214115.       fts5DataRemoveSegment(p, pLvl->aSeg[i].iSegid);

  214116.     }

  214117. 

  214118.     /* Remove the redundant segments from the input level */

  214119.     if( pLvl->nSeg!=nInput ){

  214120.       int nMove = (pLvl->nSeg - nInput) * sizeof(Fts5StructureSegment);

  214121.       memmove(pLvl->aSeg, &pLvl->aSeg[nInput], nMove);

  214122.     }

  214123.     pStruct->nSegment -= nInput;

  214124.     pLvl->nSeg -= nInput;

  214125.     pLvl->nMerge = 0;

  214126.     if( pSeg->pgnoLast==0 ){

  214127.       pLvlOut->nSeg--;

  214128.       pStruct->nSegment--;

  214129.     }

  214130.   }else{

  214131.     assert( pSeg->pgnoLast>0 );

  214132.     fts5TrimSegments(p, pIter);

  214133.     pLvl->nMerge = nInput;

  214134.   }

  214135. 

  214136.   fts5MultiIterFree(pIter);

  214137.   fts5BufferFree(&term);

  214138.   if( pnRem ) *pnRem -= writer.nLeafWritten;

  214139. }

  214140. 

  214141. /*

  214142. ** Do up to nPg pages of automerge work on the index.

  214143. **

  214144. ** Return true if any changes were actually made, or false otherwise.

  214145. */

  214146. static int fts5IndexMerge(

  214147.   Fts5Index *p,                   /* FTS5 backend object */

  214148.   Fts5Structure **ppStruct,       /* IN/OUT: Current structure of index */

  214149.   int nPg,                        /* Pages of work to do */

  214150.   int nMin                        /* Minimum number of segments to merge */

  214151. ){

  214152.   int nRem = nPg;

  214153.   int bRet = 0;

  214154.   Fts5Structure *pStruct = *ppStruct;

  214155.   while( nRem>0 && p->rc==SQLITE_OK ){

  214156.     int iLvl;                   /* To iterate through levels */

  214157.     int iBestLvl = 0;           /* Level offering the most input segments */

  214158.     int nBest = 0;              /* Number of input segments on best level */

  214159. 

  214160.     /* Set iBestLvl to the level to read input segments from. */

  214161.     assert( pStruct->nLevel>0 );

  214162.     for(iLvl=0; iLvl<pStruct->nLevel; iLvl++){

  214163.       Fts5StructureLevel *pLvl = &pStruct->aLevel[iLvl];

  214164.       if( pLvl->nMerge ){

  214165.         if( pLvl->nMerge>nBest ){

  214166.           iBestLvl = iLvl;

  214167.           nBest = pLvl->nMerge;

  214168.         }

  214169.         break;

  214170.       }

  214171.       if( pLvl->nSeg>nBest ){

  214172.         nBest = pLvl->nSeg;

  214173.         iBestLvl = iLvl;

  214174.       }

  214175.     }

  214176. 

  214177.     /* If nBest is still 0, then the index must be empty. */

  214178. #ifdef SQLITE_DEBUG

  214179.     for(iLvl=0; nBest==0 && iLvl<pStruct->nLevel; iLvl++){

  214180.       assert( pStruct->aLevel[iLvl].nSeg==0 );

  214181.     }

  214182. #endif

  214183. 

  214184.     if( nBest<nMin && pStruct->aLevel[iBestLvl].nMerge==0 ){

  214185.       break;

  214186.     }

  214187.     bRet = 1;

  214188.     fts5IndexMergeLevel(p, &pStruct, iBestLvl, &nRem);

  214189.     if( p->rc==SQLITE_OK && pStruct->aLevel[iBestLvl].nMerge==0 ){

  214190.       fts5StructurePromote(p, iBestLvl+1, pStruct);

  214191.     }

  214192.   }

  214193.   *ppStruct = pStruct;

  214194.   return bRet;

  214195. }

  214196. 

  214197. /*

  214198. ** A total of nLeaf leaf pages of data has just been flushed to a level-0

  214199. ** segment. This function updates the write-counter accordingly and, if

  214200. ** necessary, performs incremental merge work.

  214201. **

  214202. ** If an error occurs, set the Fts5Index.rc error code. If an error has 

  214203. ** already occurred, this function is a no-op.

  214204. */

  214205. static void fts5IndexAutomerge(

  214206.   Fts5Index *p,                   /* FTS5 backend object */

  214207.   Fts5Structure **ppStruct,       /* IN/OUT: Current structure of index */

  214208.   int nLeaf                       /* Number of output leaves just written */

  214209. ){

  214210.   if( p->rc==SQLITE_OK && p->pConfig->nAutomerge>0 ){

  214211.     Fts5Structure *pStruct = *ppStruct;

  214212.     u64 nWrite;                   /* Initial value of write-counter */

  214213.     int nWork;                    /* Number of work-quanta to perform */

  214214.     int nRem;                     /* Number of leaf pages left to write */

  214215. 

  214216.     /* Update the write-counter. While doing so, set nWork. */

  214217.     nWrite = pStruct->nWriteCounter;

  214218.     nWork = (int)(((nWrite + nLeaf) / p->nWorkUnit) - (nWrite / p->nWorkUnit));

  214219.     pStruct->nWriteCounter += nLeaf;

  214220.     nRem = (int)(p->nWorkUnit * nWork * pStruct->nLevel);

  214221. 

  214222.     fts5IndexMerge(p, ppStruct, nRem, p->pConfig->nAutomerge);

  214223.   }

  214224. }

  214225. 

  214226. static void fts5IndexCrisismerge(

  214227.   Fts5Index *p,                   /* FTS5 backend object */

  214228.   Fts5Structure **ppStruct        /* IN/OUT: Current structure of index */

  214229. ){

  214230.   const int nCrisis = p->pConfig->nCrisisMerge;

  214231.   Fts5Structure *pStruct = *ppStruct;

  214232.   int iLvl = 0;

  214233. 

  214234.   assert( p->rc!=SQLITE_OK || pStruct->nLevel>0 );

  214235.   while( p->rc==SQLITE_OK && pStruct->aLevel[iLvl].nSeg>=nCrisis ){

  214236.     fts5IndexMergeLevel(p, &pStruct, iLvl, 0);

  214237.     assert( p->rc!=SQLITE_OK || pStruct->nLevel>(iLvl+1) );

  214238.     fts5StructurePromote(p, iLvl+1, pStruct);

  214239.     iLvl++;

  214240.   }

  214241.   *ppStruct = pStruct;

  214242. }

  214243. 

  214244. static int fts5IndexReturn(Fts5Index *p){

  214245.   int rc = p->rc;

  214246.   p->rc = SQLITE_OK;

  214247.   return rc;

  214248. }

  214249. 

  214250. typedef struct Fts5FlushCtx Fts5FlushCtx;

  214251. struct Fts5FlushCtx {

  214252.   Fts5Index *pIdx;

  214253.   Fts5SegWriter writer; 

  214254. };

  214255. 

  214256. /*

  214257. ** Buffer aBuf[] contains a list of varints, all small enough to fit

  214258. ** in a 32-bit integer. Return the size of the largest prefix of this 

  214259. ** list nMax bytes or less in size.

  214260. */

  214261. static int fts5PoslistPrefix(const u8 *aBuf, int nMax){

  214262.   int ret;

  214263.   u32 dummy;

  214264.   ret = fts5GetVarint32(aBuf, dummy);

  214265.   if( ret<nMax ){

  214266.     while( 1 ){

  214267.       int i = fts5GetVarint32(&aBuf[ret], dummy);

  214268.       if( (ret + i) > nMax ) break;

  214269.       ret += i;

  214270.     }

  214271.   }

  214272.   return ret;

  214273. }

  214274. 

  214275. /*

  214276. ** Flush the contents of in-memory hash table iHash to a new level-0 

  214277. ** segment on disk. Also update the corresponding structure record.

  214278. **

  214279. ** If an error occurs, set the Fts5Index.rc error code. If an error has 

  214280. ** already occurred, this function is a no-op.

  214281. */

  214282. static void fts5FlushOneHash(Fts5Index *p){

  214283.   Fts5Hash *pHash = p->pHash;

  214284.   Fts5Structure *pStruct;

  214285.   int iSegid;

  214286.   int pgnoLast = 0;                 /* Last leaf page number in segment */

  214287. 

  214288.   /* Obtain a reference to the index structure and allocate a new segment-id

  214289.   ** for the new level-0 segment.  */

  214290.   pStruct = fts5StructureRead(p);

  214291.   iSegid = fts5AllocateSegid(p, pStruct);

  214292.   fts5StructureInvalidate(p);

  214293. 

  214294.   if( iSegid ){

  214295.     const int pgsz = p->pConfig->pgsz;

  214296.     int eDetail = p->pConfig->eDetail;

  214297.     Fts5StructureSegment *pSeg;   /* New segment within pStruct */

  214298.     Fts5Buffer *pBuf;             /* Buffer in which to assemble leaf page */

  214299.     Fts5Buffer *pPgidx;           /* Buffer in which to assemble pgidx */

  214300. 

  214301.     Fts5SegWriter writer;

  214302.     fts5WriteInit(p, &writer, iSegid);

  214303. 

  214304.     pBuf = &writer.writer.buf;

  214305.     pPgidx = &writer.writer.pgidx;

  214306. 

  214307.     /* fts5WriteInit() should have initialized the buffers to (most likely)

  214308.     ** the maximum space required. */

  214309.     assert( p->rc || pBuf->nSpace>=(pgsz + FTS5_DATA_PADDING) );

  214310.     assert( p->rc || pPgidx->nSpace>=(pgsz + FTS5_DATA_PADDING) );

  214311. 

  214312.     /* Begin scanning through hash table entries. This loop runs once for each

  214313.     ** term/doclist currently stored within the hash table. */

  214314.     if( p->rc==SQLITE_OK ){

  214315.       p->rc = sqlite3Fts5HashScanInit(pHash, 0, 0);

  214316.     }

  214317.     while( p->rc==SQLITE_OK && 0==sqlite3Fts5HashScanEof(pHash) ){

  214318.       const char *zTerm;          /* Buffer containing term */

  214319.       const u8 *pDoclist;         /* Pointer to doclist for this term */

  214320.       int nDoclist;               /* Size of doclist in bytes */

  214321. 

  214322.       /* Write the term for this entry to disk. */

  214323.       sqlite3Fts5HashScanEntry(pHash, &zTerm, &pDoclist, &nDoclist);

  214324.       fts5WriteAppendTerm(p, &writer, (int)strlen(zTerm), (const u8*)zTerm);

  214325.       if( p->rc!=SQLITE_OK ) break;

  214326. 

  214327.       assert( writer.bFirstRowidInPage==0 );

  214328.       if( pgsz>=(pBuf->n + pPgidx->n + nDoclist + 1) ){

  214329.         /* The entire doclist will fit on the current leaf. */

  214330.         fts5BufferSafeAppendBlob(pBuf, pDoclist, nDoclist);

  214331.       }else{

  214332.         i64 iRowid = 0;

  214333.         i64 iDelta = 0;

  214334.         int iOff = 0;

  214335. 

  214336.         /* The entire doclist will not fit on this leaf. The following 

  214337.         ** loop iterates through the poslists that make up the current 

  214338.         ** doclist.  */

  214339.         while( p->rc==SQLITE_OK && iOff<nDoclist ){

  214340.           iOff += fts5GetVarint(&pDoclist[iOff], (u64*)&iDelta);

  214341.           iRowid += iDelta;

  214342.           

  214343.           if( writer.bFirstRowidInPage ){

  214344.             fts5PutU16(&pBuf->p[0], (u16)pBuf->n);   /* first rowid on page */

  214345.             pBuf->n += sqlite3Fts5PutVarint(&pBuf->p[pBuf->n], iRowid);

  214346.             writer.bFirstRowidInPage = 0;

  214347.             fts5WriteDlidxAppend(p, &writer, iRowid);

  214348.             if( p->rc!=SQLITE_OK ) break;

  214349.           }else{

  214350.             pBuf->n += sqlite3Fts5PutVarint(&pBuf->p[pBuf->n], iDelta);

  214351.           }

  214352.           assert( pBuf->n<=pBuf->nSpace );

  214353. 

  214354.           if( eDetail==FTS5_DETAIL_NONE ){

  214355.             if( iOff<nDoclist && pDoclist[iOff]==0 ){

  214356.               pBuf->p[pBuf->n++] = 0;

  214357.               iOff++;

  214358.               if( iOff<nDoclist && pDoclist[iOff]==0 ){

  214359.                 pBuf->p[pBuf->n++] = 0;

  214360.                 iOff++;

  214361.               }

  214362.             }

  214363.             if( (pBuf->n + pPgidx->n)>=pgsz ){

  214364.               fts5WriteFlushLeaf(p, &writer);

  214365.             }

  214366.           }else{

  214367.             int bDummy;

  214368.             int nPos;

  214369.             int nCopy = fts5GetPoslistSize(&pDoclist[iOff], &nPos, &bDummy);

  214370.             nCopy += nPos;

  214371.             if( (pBuf->n + pPgidx->n + nCopy) <= pgsz ){

  214372.               /* The entire poslist will fit on the current leaf. So copy

  214373.               ** it in one go. */

  214374.               fts5BufferSafeAppendBlob(pBuf, &pDoclist[iOff], nCopy);

  214375.             }else{

  214376.               /* The entire poslist will not fit on this leaf. So it needs

  214377.               ** to be broken into sections. The only qualification being

  214378.               ** that each varint must be stored contiguously.  */

  214379.               const u8 *pPoslist = &pDoclist[iOff];

  214380.               int iPos = 0;

  214381.               while( p->rc==SQLITE_OK ){

  214382.                 int nSpace = pgsz - pBuf->n - pPgidx->n;

  214383.                 int n = 0;

  214384.                 if( (nCopy - iPos)<=nSpace ){

  214385.                   n = nCopy - iPos;

  214386.                 }else{

  214387.                   n = fts5PoslistPrefix(&pPoslist[iPos], nSpace);

  214388.                 }

  214389.                 assert( n>0 );

  214390.                 fts5BufferSafeAppendBlob(pBuf, &pPoslist[iPos], n);

  214391.                 iPos += n;

  214392.                 if( (pBuf->n + pPgidx->n)>=pgsz ){

  214393.                   fts5WriteFlushLeaf(p, &writer);

  214394.                 }

  214395.                 if( iPos>=nCopy ) break;

  214396.               }

  214397.             }

  214398.             iOff += nCopy;

  214399.           }

  214400.         }

  214401.       }

  214402. 

  214403.       /* TODO2: Doclist terminator written here. */

  214404.       /* pBuf->p[pBuf->n++] = '\0'; */

  214405.       assert( pBuf->n<=pBuf->nSpace );

  214406.       if( p->rc==SQLITE_OK ) sqlite3Fts5HashScanNext(pHash);

  214407.     }

  214408.     sqlite3Fts5HashClear(pHash);

  214409.     fts5WriteFinish(p, &writer, &pgnoLast);

  214410. 

  214411.     /* Update the Fts5Structure. It is written back to the database by the

  214412.     ** fts5StructureRelease() call below.  */

  214413.     if( pStruct->nLevel==0 ){

  214414.       fts5StructureAddLevel(&p->rc, &pStruct);

  214415.     }

  214416.     fts5StructureExtendLevel(&p->rc, pStruct, 0, 1, 0);

  214417.     if( p->rc==SQLITE_OK ){

  214418.       pSeg = &pStruct->aLevel[0].aSeg[ pStruct->aLevel[0].nSeg++ ];

  214419.       pSeg->iSegid = iSegid;

  214420.       pSeg->pgnoFirst = 1;

  214421.       pSeg->pgnoLast = pgnoLast;

  214422.       pStruct->nSegment++;

  214423.     }

  214424.     fts5StructurePromote(p, 0, pStruct);

  214425.   }

  214426. 

  214427.   fts5IndexAutomerge(p, &pStruct, pgnoLast);

  214428.   fts5IndexCrisismerge(p, &pStruct);

  214429.   fts5StructureWrite(p, pStruct);

  214430.   fts5StructureRelease(pStruct);

  214431. }

  214432. 

  214433. /*

  214434. ** Flush any data stored in the in-memory hash tables to the database.

  214435. */

  214436. static void fts5IndexFlush(Fts5Index *p){

  214437.   /* Unless it is empty, flush the hash table to disk */

  214438.   if( p->nPendingData ){

  214439.     assert( p->pHash );

  214440.     p->nPendingData = 0;

  214441.     fts5FlushOneHash(p);

  214442.   }

  214443. }

  214444. 

  214445. static Fts5Structure *fts5IndexOptimizeStruct(

  214446.   Fts5Index *p, 

  214447.   Fts5Structure *pStruct

  214448. ){

  214449.   Fts5Structure *pNew = 0;

  214450.   sqlite3_int64 nByte = sizeof(Fts5Structure);

  214451.   int nSeg = pStruct->nSegment;

  214452.   int i;

  214453. 

  214454.   /* Figure out if this structure requires optimization. A structure does

  214455.   ** not require optimization if either:

  214456.   **

  214457.   **  + it consists of fewer than two segments, or 

  214458.   **  + all segments are on the same level, or

  214459.   **  + all segments except one are currently inputs to a merge operation.

  214460.   **

  214461.   ** In the first case, return NULL. In the second, increment the ref-count

  214462.   ** on *pStruct and return a copy of the pointer to it.

  214463.   */

  214464.   if( nSeg<2 ) return 0;

  214465.   for(i=0; i<pStruct->nLevel; i++){

  214466.     int nThis = pStruct->aLevel[i].nSeg;

  214467.     if( nThis==nSeg || (nThis==nSeg-1 && pStruct->aLevel[i].nMerge==nThis) ){

  214468.       fts5StructureRef(pStruct);

  214469.       return pStruct;

  214470.     }

  214471.     assert( pStruct->aLevel[i].nMerge<=nThis );

  214472.   }

  214473. 

  214474.   nByte += (pStruct->nLevel+1) * sizeof(Fts5StructureLevel);

  214475.   pNew = (Fts5Structure*)sqlite3Fts5MallocZero(&p->rc, nByte);

  214476. 

  214477.   if( pNew ){

  214478.     Fts5StructureLevel *pLvl;

  214479.     nByte = nSeg * sizeof(Fts5StructureSegment);

  214480.     pNew->nLevel = pStruct->nLevel+1;

  214481.     pNew->nRef = 1;

  214482.     pNew->nWriteCounter = pStruct->nWriteCounter;

  214483.     pLvl = &pNew->aLevel[pStruct->nLevel];

  214484.     pLvl->aSeg = (Fts5StructureSegment*)sqlite3Fts5MallocZero(&p->rc, nByte);

  214485.     if( pLvl->aSeg ){

  214486.       int iLvl, iSeg;

  214487.       int iSegOut = 0;

  214488.       /* Iterate through all segments, from oldest to newest. Add them to

  214489.       ** the new Fts5Level object so that pLvl->aSeg[0] is the oldest

  214490.       ** segment in the data structure.  */

  214491.       for(iLvl=pStruct->nLevel-1; iLvl>=0; iLvl--){

  214492.         for(iSeg=0; iSeg<pStruct->aLevel[iLvl].nSeg; iSeg++){

  214493.           pLvl->aSeg[iSegOut] = pStruct->aLevel[iLvl].aSeg[iSeg];

  214494.           iSegOut++;

  214495.         }

  214496.       }

  214497.       pNew->nSegment = pLvl->nSeg = nSeg;

  214498.     }else{

  214499.       sqlite3_free(pNew);

  214500.       pNew = 0;

  214501.     }

  214502.   }

  214503. 

  214504.   return pNew;

  214505. }

  214506. 

  214507. static int sqlite3Fts5IndexOptimize(Fts5Index *p){

  214508.   Fts5Structure *pStruct;

  214509.   Fts5Structure *pNew = 0;

  214510. 

  214511.   assert( p->rc==SQLITE_OK );

  214512.   fts5IndexFlush(p);

  214513.   pStruct = fts5StructureRead(p);

  214514.   fts5StructureInvalidate(p);

  214515. 

  214516.   if( pStruct ){

  214517.     pNew = fts5IndexOptimizeStruct(p, pStruct);

  214518.   }

  214519.   fts5StructureRelease(pStruct);

  214520. 

  214521.   assert( pNew==0 || pNew->nSegment>0 );

  214522.   if( pNew ){

  214523.     int iLvl;

  214524.     for(iLvl=0; pNew->aLevel[iLvl].nSeg==0; iLvl++){}

  214525.     while( p->rc==SQLITE_OK && pNew->aLevel[iLvl].nSeg>0 ){

  214526.       int nRem = FTS5_OPT_WORK_UNIT;

  214527.       fts5IndexMergeLevel(p, &pNew, iLvl, &nRem);

  214528.     }

  214529. 

  214530.     fts5StructureWrite(p, pNew);

  214531.     fts5StructureRelease(pNew);

  214532.   }

  214533. 

  214534.   return fts5IndexReturn(p); 

  214535. }

  214536. 

  214537. /*

  214538. ** This is called to implement the special "VALUES('merge', $nMerge)"

  214539. ** INSERT command.

  214540. */

  214541. static int sqlite3Fts5IndexMerge(Fts5Index *p, int nMerge){

  214542.   Fts5Structure *pStruct = fts5StructureRead(p);

  214543.   if( pStruct ){

  214544.     int nMin = p->pConfig->nUsermerge;

  214545.     fts5StructureInvalidate(p);

  214546.     if( nMerge<0 ){

  214547.       Fts5Structure *pNew = fts5IndexOptimizeStruct(p, pStruct);

  214548.       fts5StructureRelease(pStruct);

  214549.       pStruct = pNew;

  214550.       nMin = 2;

  214551.       nMerge = nMerge*-1;

  214552.     }

  214553.     if( pStruct && pStruct->nLevel ){

  214554.       if( fts5IndexMerge(p, &pStruct, nMerge, nMin) ){

  214555.         fts5StructureWrite(p, pStruct);

  214556.       }

  214557.     }

  214558.     fts5StructureRelease(pStruct);

  214559.   }

  214560.   return fts5IndexReturn(p);

  214561. }

  214562. 

  214563. static void fts5AppendRowid(

  214564.   Fts5Index *p,

  214565.   i64 iDelta,

  214566.   Fts5Iter *pUnused,

  214567.   Fts5Buffer *pBuf

  214568. ){

  214569.   UNUSED_PARAM(pUnused);

  214570.   fts5BufferAppendVarint(&p->rc, pBuf, iDelta);

  214571. }

  214572. 

  214573. static void fts5AppendPoslist(

  214574.   Fts5Index *p,

  214575.   i64 iDelta,

  214576.   Fts5Iter *pMulti,

  214577.   Fts5Buffer *pBuf

  214578. ){

  214579.   int nData = pMulti->base.nData;

  214580.   int nByte = nData + 9 + 9 + FTS5_DATA_ZERO_PADDING;

  214581.   assert( nData>0 );

  214582.   if( p->rc==SQLITE_OK && 0==fts5BufferGrow(&p->rc, pBuf, nByte) ){

  214583.     fts5BufferSafeAppendVarint(pBuf, iDelta);

  214584.     fts5BufferSafeAppendVarint(pBuf, nData*2);

  214585.     fts5BufferSafeAppendBlob(pBuf, pMulti->base.pData, nData);

  214586.     memset(&pBuf->p[pBuf->n], 0, FTS5_DATA_ZERO_PADDING);

  214587.   }

  214588. }

  214589. 

  214590. 

  214591. static void fts5DoclistIterNext(Fts5DoclistIter *pIter){

  214592.   u8 *p = pIter->aPoslist + pIter->nSize + pIter->nPoslist;

  214593. 

  214594.   assert( pIter->aPoslist );

  214595.   if( p>=pIter->aEof ){

  214596.     pIter->aPoslist = 0;

  214597.   }else{

  214598.     i64 iDelta;

  214599. 

  214600.     p += fts5GetVarint(p, (u64*)&iDelta);

  214601.     pIter->iRowid += iDelta;

  214602. 

  214603.     /* Read position list size */

  214604.     if( p[0] & 0x80 ){

  214605.       int nPos;

  214606.       pIter->nSize = fts5GetVarint32(p, nPos);

  214607.       pIter->nPoslist = (nPos>>1);

  214608.     }else{

  214609.       pIter->nPoslist = ((int)(p[0])) >> 1;

  214610.       pIter->nSize = 1;

  214611.     }

  214612. 

  214613.     pIter->aPoslist = p;

  214614.   }

  214615. }

  214616. 

  214617. static void fts5DoclistIterInit(

  214618.   Fts5Buffer *pBuf, 

  214619.   Fts5DoclistIter *pIter

  214620. ){

  214621.   memset(pIter, 0, sizeof(*pIter));

  214622.   pIter->aPoslist = pBuf->p;

  214623.   pIter->aEof = &pBuf->p[pBuf->n];

  214624.   fts5DoclistIterNext(pIter);

  214625. }

  214626. 

  214627. #if 0

  214628. /*

  214629. ** Append a doclist to buffer pBuf.

  214630. **

  214631. ** This function assumes that space within the buffer has already been

  214632. ** allocated.

  214633. */

  214634. static void fts5MergeAppendDocid(

  214635.   Fts5Buffer *pBuf,               /* Buffer to write to */

  214636.   i64 *piLastRowid,               /* IN/OUT: Previous rowid written (if any) */

  214637.   i64 iRowid                      /* Rowid to append */

  214638. ){

  214639.   assert( pBuf->n!=0 || (*piLastRowid)==0 );

  214640.   fts5BufferSafeAppendVarint(pBuf, iRowid - *piLastRowid);

  214641.   *piLastRowid = iRowid;

  214642. }

  214643. #endif

  214644. 

  214645. #define fts5MergeAppendDocid(pBuf, iLastRowid, iRowid) {       \

  214646.   assert( (pBuf)->n!=0 || (iLastRowid)==0 );                   \

  214647.   fts5BufferSafeAppendVarint((pBuf), (iRowid) - (iLastRowid)); \

  214648.   (iLastRowid) = (iRowid);                                     \

  214649. }

  214650. 

  214651. /*

  214652. ** Swap the contents of buffer *p1 with that of *p2.

  214653. */

  214654. static void fts5BufferSwap(Fts5Buffer *p1, Fts5Buffer *p2){

  214655.   Fts5Buffer tmp = *p1;

  214656.   *p1 = *p2;

  214657.   *p2 = tmp;

  214658. }

  214659. 

  214660. static void fts5NextRowid(Fts5Buffer *pBuf, int *piOff, i64 *piRowid){

  214661.   int i = *piOff;

  214662.   if( i>=pBuf->n ){

  214663.     *piOff = -1;

  214664.   }else{

  214665.     u64 iVal;

  214666.     *piOff = i + sqlite3Fts5GetVarint(&pBuf->p[i], &iVal);

  214667.     *piRowid += iVal;

  214668.   }

  214669. }

  214670. 

  214671. /*

  214672. ** This is the equivalent of fts5MergePrefixLists() for detail=none mode.

  214673. ** In this case the buffers consist of a delta-encoded list of rowids only.

  214674. */

  214675. static void fts5MergeRowidLists(

  214676.   Fts5Index *p,                   /* FTS5 backend object */

  214677.   Fts5Buffer *p1,                 /* First list to merge */

  214678.   Fts5Buffer *p2                  /* Second list to merge */

  214679. ){

  214680.   int i1 = 0;

  214681.   int i2 = 0;

  214682.   i64 iRowid1 = 0;

  214683.   i64 iRowid2 = 0;

  214684.   i64 iOut = 0;

  214685. 

  214686.   Fts5Buffer out;

  214687.   memset(&out, 0, sizeof(out));

  214688.   sqlite3Fts5BufferSize(&p->rc, &out, p1->n + p2->n);

  214689.   if( p->rc ) return;

  214690. 

  214691.   fts5NextRowid(p1, &i1, &iRowid1);

  214692.   fts5NextRowid(p2, &i2, &iRowid2);

  214693.   while( i1>=0 || i2>=0 ){

  214694.     if( i1>=0 && (i2<0 || iRowid1<iRowid2) ){

  214695.       assert( iOut==0 || iRowid1>iOut );

  214696.       fts5BufferSafeAppendVarint(&out, iRowid1 - iOut);

  214697.       iOut = iRowid1;

  214698.       fts5NextRowid(p1, &i1, &iRowid1);

  214699.     }else{

  214700.       assert( iOut==0 || iRowid2>iOut );

  214701.       fts5BufferSafeAppendVarint(&out, iRowid2 - iOut);

  214702.       iOut = iRowid2;

  214703.       if( i1>=0 && iRowid1==iRowid2 ){

  214704.         fts5NextRowid(p1, &i1, &iRowid1);

  214705.       }

  214706.       fts5NextRowid(p2, &i2, &iRowid2);

  214707.     }

  214708.   }

  214709. 

  214710.   fts5BufferSwap(&out, p1);

  214711.   fts5BufferFree(&out);

  214712. }

  214713. 

  214714. /*

  214715. ** Buffers p1 and p2 contain doclists. This function merges the content

  214716. ** of the two doclists together and sets buffer p1 to the result before

  214717. ** returning.

  214718. **

  214719. ** If an error occurs, an error code is left in p->rc. If an error has

  214720. ** already occurred, this function is a no-op.

  214721. */

  214722. static void fts5MergePrefixLists(

  214723.   Fts5Index *p,                   /* FTS5 backend object */

  214724.   Fts5Buffer *p1,                 /* First list to merge */

  214725.   Fts5Buffer *p2                  /* Second list to merge */

  214726. ){

  214727.   if( p2->n ){

  214728.     i64 iLastRowid = 0;

  214729.     Fts5DoclistIter i1;

  214730.     Fts5DoclistIter i2;

  214731.     Fts5Buffer out = {0, 0, 0};

  214732.     Fts5Buffer tmp = {0, 0, 0};

  214733. 

  214734.     /* The maximum size of the output is equal to the sum of the two 

  214735.     ** input sizes + 1 varint (9 bytes). The extra varint is because if the

  214736.     ** first rowid in one input is a large negative number, and the first in

  214737.     ** the other a non-negative number, the delta for the non-negative

  214738.     ** number will be larger on disk than the literal integer value

  214739.     ** was.  

  214740.     **

  214741.     ** Or, if the input position-lists are corrupt, then the output might

  214742.     ** include up to 2 extra 10-byte positions created by interpreting -1

  214743.     ** (the value PoslistNext64() uses for EOF) as a position and appending

  214744.     ** it to the output. This can happen at most once for each input 

  214745.     ** position-list, hence two 10 byte paddings.  */

  214746.     if( sqlite3Fts5BufferSize(&p->rc, &out, p1->n + p2->n + 9+10+10) ) return;

  214747.     fts5DoclistIterInit(p1, &i1);

  214748.     fts5DoclistIterInit(p2, &i2);

  214749. 

  214750.     while( 1 ){

  214751.       if( i1.iRowid<i2.iRowid ){

  214752.         /* Copy entry from i1 */

  214753.         fts5MergeAppendDocid(&out, iLastRowid, i1.iRowid);

  214754.         fts5BufferSafeAppendBlob(&out, i1.aPoslist, i1.nPoslist+i1.nSize);

  214755.         fts5DoclistIterNext(&i1);

  214756.         if( i1.aPoslist==0 ) break;

  214757.         assert( out.n<=((i1.aPoslist-p1->p) + (i2.aPoslist-p2->p)+9+10+10) );

  214758.       }

  214759.       else if( i2.iRowid!=i1.iRowid ){

  214760.         /* Copy entry from i2 */

  214761.         fts5MergeAppendDocid(&out, iLastRowid, i2.iRowid);

  214762.         fts5BufferSafeAppendBlob(&out, i2.aPoslist, i2.nPoslist+i2.nSize);

  214763.         fts5DoclistIterNext(&i2);

  214764.         if( i2.aPoslist==0 ) break;

  214765.         assert( out.n<=((i1.aPoslist-p1->p) + (i2.aPoslist-p2->p)+9+10+10) );

  214766.       }

  214767.       else{

  214768.         /* Merge the two position lists. */ 

  214769.         i64 iPos1 = 0;

  214770.         i64 iPos2 = 0;

  214771.         int iOff1 = 0;

  214772.         int iOff2 = 0;

  214773.         u8 *a1 = &i1.aPoslist[i1.nSize];

  214774.         u8 *a2 = &i2.aPoslist[i2.nSize];

  214775.         int nCopy;

  214776.         u8 *aCopy;

  214777. 

  214778.         i64 iPrev = 0;

  214779.         Fts5PoslistWriter writer;

  214780.         memset(&writer, 0, sizeof(writer));

  214781. 

  214782.         fts5MergeAppendDocid(&out, iLastRowid, i2.iRowid);

  214783.         fts5BufferZero(&tmp);

  214784.         sqlite3Fts5BufferSize(&p->rc, &tmp, i1.nPoslist + i2.nPoslist);

  214785.         if( p->rc ) break;

  214786. 

  214787.         sqlite3Fts5PoslistNext64(a1, i1.nPoslist, &iOff1, &iPos1);

  214788.         sqlite3Fts5PoslistNext64(a2, i2.nPoslist, &iOff2, &iPos2);

  214789.         assert_nc( iPos1>=0 && iPos2>=0 );

  214790. 

  214791.         if( iPos1<iPos2 ){

  214792.           sqlite3Fts5PoslistSafeAppend(&tmp, &iPrev, iPos1);

  214793.           sqlite3Fts5PoslistNext64(a1, i1.nPoslist, &iOff1, &iPos1);

  214794.         }else{

  214795.           sqlite3Fts5PoslistSafeAppend(&tmp, &iPrev, iPos2);

  214796.           sqlite3Fts5PoslistNext64(a2, i2.nPoslist, &iOff2, &iPos2);

  214797.         }

  214798.         if( iPos1>=0 && iPos2>=0 ){

  214799.           while( 1 ){

  214800.             if( iPos1<iPos2 ){

  214801.               if( iPos1!=iPrev ){

  214802.                 sqlite3Fts5PoslistSafeAppend(&tmp, &iPrev, iPos1);

  214803.               }

  214804.               sqlite3Fts5PoslistNext64(a1, i1.nPoslist, &iOff1, &iPos1);

  214805.               if( iPos1<0 ) break;

  214806.             }else{

  214807.               assert_nc( iPos2!=iPrev );

  214808.               sqlite3Fts5PoslistSafeAppend(&tmp, &iPrev, iPos2);

  214809.               sqlite3Fts5PoslistNext64(a2, i2.nPoslist, &iOff2, &iPos2);

  214810.               if( iPos2<0 ) break;

  214811.             }

  214812.           }

  214813.         }

  214814. 

  214815.         if( iPos1>=0 ){

  214816.           if( iPos1!=iPrev ){

  214817.             sqlite3Fts5PoslistSafeAppend(&tmp, &iPrev, iPos1);

  214818.           }

  214819.           aCopy = &a1[iOff1];

  214820.           nCopy = i1.nPoslist - iOff1;

  214821.         }else{

  214822.           assert_nc( iPos2>=0 && iPos2!=iPrev );

  214823.           sqlite3Fts5PoslistSafeAppend(&tmp, &iPrev, iPos2);

  214824.           aCopy = &a2[iOff2];

  214825.           nCopy = i2.nPoslist - iOff2;

  214826.         }

  214827.         if( nCopy>0 ){

  214828.           fts5BufferSafeAppendBlob(&tmp, aCopy, nCopy);

  214829.         }

  214830. 

  214831.         /* WRITEPOSLISTSIZE */

  214832.         fts5BufferSafeAppendVarint(&out, tmp.n * 2);

  214833.         fts5BufferSafeAppendBlob(&out, tmp.p, tmp.n);

  214834.         fts5DoclistIterNext(&i1);

  214835.         fts5DoclistIterNext(&i2);

  214836.         assert_nc( out.n<=(p1->n+p2->n+9) );

  214837.         if( i1.aPoslist==0 || i2.aPoslist==0 ) break;

  214838.         assert( out.n<=((i1.aPoslist-p1->p) + (i2.aPoslist-p2->p)+9+10+10) );

  214839.       }

  214840.     }

  214841. 

  214842.     if( i1.aPoslist ){

  214843.       fts5MergeAppendDocid(&out, iLastRowid, i1.iRowid);

  214844.       fts5BufferSafeAppendBlob(&out, i1.aPoslist, i1.aEof - i1.aPoslist);

  214845.     }

  214846.     else if( i2.aPoslist ){

  214847.       fts5MergeAppendDocid(&out, iLastRowid, i2.iRowid);

  214848.       fts5BufferSafeAppendBlob(&out, i2.aPoslist, i2.aEof - i2.aPoslist);

  214849.     }

  214850.     assert_nc( out.n<=(p1->n+p2->n+9) );

  214851. 

  214852.     fts5BufferSet(&p->rc, p1, out.n, out.p);

  214853.     fts5BufferFree(&tmp);

  214854.     fts5BufferFree(&out);

  214855.   }

  214856. }

  214857. 

  214858. static void fts5SetupPrefixIter(

  214859.   Fts5Index *p,                   /* Index to read from */

  214860.   int bDesc,                      /* True for "ORDER BY rowid DESC" */

  214861.   const u8 *pToken,               /* Buffer containing prefix to match */

  214862.   int nToken,                     /* Size of buffer pToken in bytes */

  214863.   Fts5Colset *pColset,            /* Restrict matches to these columns */

  214864.   Fts5Iter **ppIter          /* OUT: New iterator */

  214865. ){

  214866.   Fts5Structure *pStruct;

  214867.   Fts5Buffer *aBuf;

  214868.   const int nBuf = 32;

  214869. 

  214870.   void (*xMerge)(Fts5Index*, Fts5Buffer*, Fts5Buffer*);

  214871.   void (*xAppend)(Fts5Index*, i64, Fts5Iter*, Fts5Buffer*);

  214872.   if( p->pConfig->eDetail==FTS5_DETAIL_NONE ){

  214873.     xMerge = fts5MergeRowidLists;

  214874.     xAppend = fts5AppendRowid;

  214875.   }else{

  214876.     xMerge = fts5MergePrefixLists;

  214877.     xAppend = fts5AppendPoslist;

  214878.   }

  214879. 

  214880.   aBuf = (Fts5Buffer*)fts5IdxMalloc(p, sizeof(Fts5Buffer)*nBuf);

  214881.   pStruct = fts5StructureRead(p);

  214882. 

  214883.   if( aBuf && pStruct ){

  214884.     const int flags = FTS5INDEX_QUERY_SCAN 

  214885.                     | FTS5INDEX_QUERY_SKIPEMPTY 

  214886.                     | FTS5INDEX_QUERY_NOOUTPUT;

  214887.     int i;

  214888.     i64 iLastRowid = 0;

  214889.     Fts5Iter *p1 = 0;     /* Iterator used to gather data from index */

  214890.     Fts5Data *pData;

  214891.     Fts5Buffer doclist;

  214892.     int bNewTerm = 1;

  214893. 

  214894.     memset(&doclist, 0, sizeof(doclist));

  214895.     fts5MultiIterNew(p, pStruct, flags, pColset, pToken, nToken, -1, 0, &p1);

  214896.     fts5IterSetOutputCb(&p->rc, p1);

  214897.     for( /* no-op */ ;

  214898.         fts5MultiIterEof(p, p1)==0;

  214899.         fts5MultiIterNext2(p, p1, &bNewTerm)

  214900.     ){

  214901.       Fts5SegIter *pSeg = &p1->aSeg[ p1->aFirst[1].iFirst ];

  214902.       int nTerm = pSeg->term.n;

  214903.       const u8 *pTerm = pSeg->term.p;

  214904.       p1->xSetOutputs(p1, pSeg);

  214905. 

  214906.       assert_nc( memcmp(pToken, pTerm, MIN(nToken, nTerm))<=0 );

  214907.       if( bNewTerm ){

  214908.         if( nTerm<nToken || memcmp(pToken, pTerm, nToken) ) break;

  214909.       }

  214910. 

  214911.       if( p1->base.nData==0 ) continue;

  214912. 

  214913.       if( p1->base.iRowid<=iLastRowid && doclist.n>0 ){

  214914.         for(i=0; p->rc==SQLITE_OK && doclist.n; i++){

  214915.           assert( i<nBuf );

  214916.           if( aBuf[i].n==0 ){

  214917.             fts5BufferSwap(&doclist, &aBuf[i]);

  214918.             fts5BufferZero(&doclist);

  214919.           }else{

  214920.             xMerge(p, &doclist, &aBuf[i]);

  214921.             fts5BufferZero(&aBuf[i]);

  214922.           }

  214923.         }

  214924.         iLastRowid = 0;

  214925.       }

  214926. 

  214927.       xAppend(p, p1->base.iRowid-iLastRowid, p1, &doclist);

  214928.       iLastRowid = p1->base.iRowid;

  214929.     }

  214930. 

  214931.     for(i=0; i<nBuf; i++){

  214932.       if( p->rc==SQLITE_OK ){

  214933.         xMerge(p, &doclist, &aBuf[i]);

  214934.       }

  214935.       fts5BufferFree(&aBuf[i]);

  214936.     }

  214937.     fts5MultiIterFree(p1);

  214938. 

  214939.     pData = fts5IdxMalloc(p, sizeof(Fts5Data)+doclist.n+FTS5_DATA_ZERO_PADDING);

  214940.     if( pData ){

  214941.       pData->p = (u8*)&pData[1];

  214942.       pData->nn = pData->szLeaf = doclist.n;

  214943.       if( doclist.n ) memcpy(pData->p, doclist.p, doclist.n);

  214944.       fts5MultiIterNew2(p, pData, bDesc, ppIter);

  214945.     }

  214946.     fts5BufferFree(&doclist);

  214947.   }

  214948. 

  214949.   fts5StructureRelease(pStruct);

  214950.   sqlite3_free(aBuf);

  214951. }

  214952. 

  214953. 

  214954. /*

  214955. ** Indicate that all subsequent calls to sqlite3Fts5IndexWrite() pertain

  214956. ** to the document with rowid iRowid.

  214957. */

  214958. static int sqlite3Fts5IndexBeginWrite(Fts5Index *p, int bDelete, i64 iRowid){

  214959.   assert( p->rc==SQLITE_OK );

  214960. 

  214961.   /* Allocate the hash table if it has not already been allocated */

  214962.   if( p->pHash==0 ){

  214963.     p->rc = sqlite3Fts5HashNew(p->pConfig, &p->pHash, &p->nPendingData);

  214964.   }

  214965. 

  214966.   /* Flush the hash table to disk if required */

  214967.   if( iRowid<p->iWriteRowid 

  214968.    || (iRowid==p->iWriteRowid && p->bDelete==0)

  214969.    || (p->nPendingData > p->pConfig->nHashSize) 

  214970.   ){

  214971.     fts5IndexFlush(p);

  214972.   }

  214973. 

  214974.   p->iWriteRowid = iRowid;

  214975.   p->bDelete = bDelete;

  214976.   return fts5IndexReturn(p);

  214977. }

  214978. 

  214979. /*

  214980. ** Commit data to disk.

  214981. */

  214982. static int sqlite3Fts5IndexSync(Fts5Index *p){

  214983.   assert( p->rc==SQLITE_OK );

  214984.   fts5IndexFlush(p);

  214985.   fts5CloseReader(p);

  214986.   return fts5IndexReturn(p);

  214987. }

  214988. 

  214989. /*

  214990. ** Discard any data stored in the in-memory hash tables. Do not write it

  214991. ** to the database. Additionally, assume that the contents of the %_data

  214992. ** table may have changed on disk. So any in-memory caches of %_data 

  214993. ** records must be invalidated.

  214994. */

  214995. static int sqlite3Fts5IndexRollback(Fts5Index *p){

  214996.   fts5CloseReader(p);

  214997.   fts5IndexDiscardData(p);

  214998.   fts5StructureInvalidate(p);

  214999.   /* assert( p->rc==SQLITE_OK ); */

  215000.   return SQLITE_OK;

  215001. }

  215002. 

  215003. /*

  215004. ** The %_data table is completely empty when this function is called. This

  215005. ** function populates it with the initial structure objects for each index,

  215006. ** and the initial version of the "averages" record (a zero-byte blob).

  215007. */

  215008. static int sqlite3Fts5IndexReinit(Fts5Index *p){

  215009.   Fts5Structure s;

  215010.   fts5StructureInvalidate(p);

  215011.   memset(&s, 0, sizeof(Fts5Structure));

  215012.   fts5DataWrite(p, FTS5_AVERAGES_ROWID, (const u8*)"", 0);

  215013.   fts5StructureWrite(p, &s);

  215014.   return fts5IndexReturn(p);

  215015. }

  215016. 

  215017. /*

  215018. ** Open a new Fts5Index handle. If the bCreate argument is true, create

  215019. ** and initialize the underlying %_data table.

  215020. **

  215021. ** If successful, set *pp to point to the new object and return SQLITE_OK.

  215022. ** Otherwise, set *pp to NULL and return an SQLite error code.

  215023. */

  215024. static int sqlite3Fts5IndexOpen(

  215025.   Fts5Config *pConfig, 

  215026.   int bCreate, 

  215027.   Fts5Index **pp,

  215028.   char **pzErr

  215029. ){

  215030.   int rc = SQLITE_OK;

  215031.   Fts5Index *p;                   /* New object */

  215032. 

  215033.   *pp = p = (Fts5Index*)sqlite3Fts5MallocZero(&rc, sizeof(Fts5Index));

  215034.   if( rc==SQLITE_OK ){

  215035.     p->pConfig = pConfig;

  215036.     p->nWorkUnit = FTS5_WORK_UNIT;

  215037.     p->zDataTbl = sqlite3Fts5Mprintf(&rc, "%s_data", pConfig->zName);

  215038.     if( p->zDataTbl && bCreate ){

  215039.       rc = sqlite3Fts5CreateTable(

  215040.           pConfig, "data", "id INTEGER PRIMARY KEY, block BLOB", 0, pzErr

  215041.       );

  215042.       if( rc==SQLITE_OK ){

  215043.         rc = sqlite3Fts5CreateTable(pConfig, "idx", 

  215044.             "segid, term, pgno, PRIMARY KEY(segid, term)", 

  215045.             1, pzErr

  215046.         );

  215047.       }

  215048.       if( rc==SQLITE_OK ){

  215049.         rc = sqlite3Fts5IndexReinit(p);

  215050.       }

  215051.     }

  215052.   }

  215053. 

  215054.   assert( rc!=SQLITE_OK || p->rc==SQLITE_OK );

  215055.   if( rc ){

  215056.     sqlite3Fts5IndexClose(p);

  215057.     *pp = 0;

  215058.   }

  215059.   return rc;

  215060. }

  215061. 

  215062. /*

  215063. ** Close a handle opened by an earlier call to sqlite3Fts5IndexOpen().

  215064. */

  215065. static int sqlite3Fts5IndexClose(Fts5Index *p){

  215066.   int rc = SQLITE_OK;

  215067.   if( p ){

  215068.     assert( p->pReader==0 );

  215069.     fts5StructureInvalidate(p);

  215070.     sqlite3_finalize(p->pWriter);

  215071.     sqlite3_finalize(p->pDeleter);

  215072.     sqlite3_finalize(p->pIdxWriter);

  215073.     sqlite3_finalize(p->pIdxDeleter);

  215074.     sqlite3_finalize(p->pIdxSelect);

  215075.     sqlite3_finalize(p->pDataVersion);

  215076.     sqlite3Fts5HashFree(p->pHash);

  215077.     sqlite3_free(p->zDataTbl);

  215078.     sqlite3_free(p);

  215079.   }

  215080.   return rc;

  215081. }

  215082. 

  215083. /*

  215084. ** Argument p points to a buffer containing utf-8 text that is n bytes in 

  215085. ** size. Return the number of bytes in the nChar character prefix of the

  215086. ** buffer, or 0 if there are less than nChar characters in total.

  215087. */

  215088. static int sqlite3Fts5IndexCharlenToBytelen(

  215089.   const char *p, 

  215090.   int nByte, 

  215091.   int nChar

  215092. ){

  215093.   int n = 0;

  215094.   int i;

  215095.   for(i=0; i<nChar; i++){

  215096.     if( n>=nByte ) return 0;      /* Input contains fewer than nChar chars */

  215097.     if( (unsigned char)p[n++]>=0xc0 ){

  215098.       while( (p[n] & 0xc0)==0x80 ){

  215099.         n++;

  215100.         if( n>=nByte ) break;

  215101.       }

  215102.     }

  215103.   }

  215104.   return n;

  215105. }

  215106. 

  215107. /*

  215108. ** pIn is a UTF-8 encoded string, nIn bytes in size. Return the number of

  215109. ** unicode characters in the string.

  215110. */

  215111. static int fts5IndexCharlen(const char *pIn, int nIn){

  215112.   int nChar = 0;            

  215113.   int i = 0;

  215114.   while( i<nIn ){

  215115.     if( (unsigned char)pIn[i++]>=0xc0 ){

  215116.       while( i<nIn && (pIn[i] & 0xc0)==0x80 ) i++;

  215117.     }

  215118.     nChar++;

  215119.   }

  215120.   return nChar;

  215121. }

  215122. 

  215123. /*

  215124. ** Insert or remove data to or from the index. Each time a document is 

  215125. ** added to or removed from the index, this function is called one or more

  215126. ** times.

  215127. **

  215128. ** For an insert, it must be called once for each token in the new document.

  215129. ** If the operation is a delete, it must be called (at least) once for each

  215130. ** unique token in the document with an iCol value less than zero. The iPos

  215131. ** argument is ignored for a delete.

  215132. */

  215133. static int sqlite3Fts5IndexWrite(

  215134.   Fts5Index *p,                   /* Index to write to */

  215135.   int iCol,                       /* Column token appears in (-ve -> delete) */

  215136.   int iPos,                       /* Position of token within column */

  215137.   const char *pToken, int nToken  /* Token to add or remove to or from index */

  215138. ){

  215139.   int i;                          /* Used to iterate through indexes */

  215140.   int rc = SQLITE_OK;             /* Return code */

  215141.   Fts5Config *pConfig = p->pConfig;

  215142. 

  215143.   assert( p->rc==SQLITE_OK );

  215144.   assert( (iCol<0)==p->bDelete );

  215145. 

  215146.   /* Add the entry to the main terms index. */

  215147.   rc = sqlite3Fts5HashWrite(

  215148.       p->pHash, p->iWriteRowid, iCol, iPos, FTS5_MAIN_PREFIX, pToken, nToken

  215149.   );

  215150. 

  215151.   for(i=0; i<pConfig->nPrefix && rc==SQLITE_OK; i++){

  215152.     const int nChar = pConfig->aPrefix[i];

  215153.     int nByte = sqlite3Fts5IndexCharlenToBytelen(pToken, nToken, nChar);

  215154.     if( nByte ){

  215155.       rc = sqlite3Fts5HashWrite(p->pHash, 

  215156.           p->iWriteRowid, iCol, iPos, (char)(FTS5_MAIN_PREFIX+i+1), pToken,

  215157.           nByte

  215158.       );

  215159.     }

  215160.   }

  215161. 

  215162.   return rc;

  215163. }

  215164. 

  215165. /*

  215166. ** Open a new iterator to iterate though all rowid that match the 

  215167. ** specified token or token prefix.

  215168. */

  215169. static int sqlite3Fts5IndexQuery(

  215170.   Fts5Index *p,                   /* FTS index to query */

  215171.   const char *pToken, int nToken, /* Token (or prefix) to query for */

  215172.   int flags,                      /* Mask of FTS5INDEX_QUERY_X flags */

  215173.   Fts5Colset *pColset,            /* Match these columns only */

  215174.   Fts5IndexIter **ppIter          /* OUT: New iterator object */

  215175. ){

  215176.   Fts5Config *pConfig = p->pConfig;

  215177.   Fts5Iter *pRet = 0;

  215178.   Fts5Buffer buf = {0, 0, 0};

  215179. 

  215180.   /* If the QUERY_SCAN flag is set, all other flags must be clear. */

  215181.   assert( (flags & FTS5INDEX_QUERY_SCAN)==0 || flags==FTS5INDEX_QUERY_SCAN );

  215182. 

  215183.   if( sqlite3Fts5BufferSize(&p->rc, &buf, nToken+1)==0 ){

  215184.     int iIdx = 0;                 /* Index to search */

  215185.     if( nToken ) memcpy(&buf.p[1], pToken, nToken);

  215186. 

  215187.     /* Figure out which index to search and set iIdx accordingly. If this

  215188.     ** is a prefix query for which there is no prefix index, set iIdx to

  215189.     ** greater than pConfig->nPrefix to indicate that the query will be

  215190.     ** satisfied by scanning multiple terms in the main index.

  215191.     **

  215192.     ** If the QUERY_TEST_NOIDX flag was specified, then this must be a

  215193.     ** prefix-query. Instead of using a prefix-index (if one exists), 

  215194.     ** evaluate the prefix query using the main FTS index. This is used

  215195.     ** for internal sanity checking by the integrity-check in debug 

  215196.     ** mode only.  */

  215197. #ifdef SQLITE_DEBUG

  215198.     if( pConfig->bPrefixIndex==0 || (flags & FTS5INDEX_QUERY_TEST_NOIDX) ){

  215199.       assert( flags & FTS5INDEX_QUERY_PREFIX );

  215200.       iIdx = 1+pConfig->nPrefix;

  215201.     }else

  215202. #endif

  215203.     if( flags & FTS5INDEX_QUERY_PREFIX ){

  215204.       int nChar = fts5IndexCharlen(pToken, nToken);

  215205.       for(iIdx=1; iIdx<=pConfig->nPrefix; iIdx++){

  215206.         if( pConfig->aPrefix[iIdx-1]==nChar ) break;

  215207.       }

  215208.     }

  215209. 

  215210.     if( iIdx<=pConfig->nPrefix ){

  215211.       /* Straight index lookup */

  215212.       Fts5Structure *pStruct = fts5StructureRead(p);

  215213.       buf.p[0] = (u8)(FTS5_MAIN_PREFIX + iIdx);

  215214.       if( pStruct ){

  215215.         fts5MultiIterNew(p, pStruct, flags | FTS5INDEX_QUERY_SKIPEMPTY, 

  215216.             pColset, buf.p, nToken+1, -1, 0, &pRet

  215217.         );

  215218.         fts5StructureRelease(pStruct);

  215219.       }

  215220.     }else{

  215221.       /* Scan multiple terms in the main index */

  215222.       int bDesc = (flags & FTS5INDEX_QUERY_DESC)!=0;

  215223.       buf.p[0] = FTS5_MAIN_PREFIX;

  215224.       fts5SetupPrefixIter(p, bDesc, buf.p, nToken+1, pColset, &pRet);

  215225.       assert( p->rc!=SQLITE_OK || pRet->pColset==0 );

  215226.       fts5IterSetOutputCb(&p->rc, pRet);

  215227.       if( p->rc==SQLITE_OK ){

  215228.         Fts5SegIter *pSeg = &pRet->aSeg[pRet->aFirst[1].iFirst];

  215229.         if( pSeg->pLeaf ) pRet->xSetOutputs(pRet, pSeg);

  215230.       }

  215231.     }

  215232. 

  215233.     if( p->rc ){

  215234.       sqlite3Fts5IterClose((Fts5IndexIter*)pRet);

  215235.       pRet = 0;

  215236.       fts5CloseReader(p);

  215237.     }

  215238. 

  215239.     *ppIter = (Fts5IndexIter*)pRet;

  215240.     sqlite3Fts5BufferFree(&buf);

  215241.   }

  215242.   return fts5IndexReturn(p);

  215243. }

  215244. 

  215245. /*

  215246. ** Return true if the iterator passed as the only argument is at EOF.

  215247. */

  215248. /*

  215249. ** Move to the next matching rowid. 

  215250. */

  215251. static int sqlite3Fts5IterNext(Fts5IndexIter *pIndexIter){

  215252.   Fts5Iter *pIter = (Fts5Iter*)pIndexIter;

  215253.   assert( pIter->pIndex->rc==SQLITE_OK );

  215254.   fts5MultiIterNext(pIter->pIndex, pIter, 0, 0);

  215255.   return fts5IndexReturn(pIter->pIndex);

  215256. }

  215257. 

  215258. /*

  215259. ** Move to the next matching term/rowid. Used by the fts5vocab module.

  215260. */

  215261. static int sqlite3Fts5IterNextScan(Fts5IndexIter *pIndexIter){

  215262.   Fts5Iter *pIter = (Fts5Iter*)pIndexIter;

  215263.   Fts5Index *p = pIter->pIndex;

  215264. 

  215265.   assert( pIter->pIndex->rc==SQLITE_OK );

  215266. 

  215267.   fts5MultiIterNext(p, pIter, 0, 0);

  215268.   if( p->rc==SQLITE_OK ){

  215269.     Fts5SegIter *pSeg = &pIter->aSeg[ pIter->aFirst[1].iFirst ];

  215270.     if( pSeg->pLeaf && pSeg->term.p[0]!=FTS5_MAIN_PREFIX ){

  215271.       fts5DataRelease(pSeg->pLeaf);

  215272.       pSeg->pLeaf = 0;

  215273.       pIter->base.bEof = 1;

  215274.     }

  215275.   }

  215276. 

  215277.   return fts5IndexReturn(pIter->pIndex);

  215278. }

  215279. 

  215280. /*

  215281. ** Move to the next matching rowid that occurs at or after iMatch. The

  215282. ** definition of "at or after" depends on whether this iterator iterates

  215283. ** in ascending or descending rowid order.

  215284. */

  215285. static int sqlite3Fts5IterNextFrom(Fts5IndexIter *pIndexIter, i64 iMatch){

  215286.   Fts5Iter *pIter = (Fts5Iter*)pIndexIter;

  215287.   fts5MultiIterNextFrom(pIter->pIndex, pIter, iMatch);

  215288.   return fts5IndexReturn(pIter->pIndex);

  215289. }

  215290. 

  215291. /*

  215292. ** Return the current term.

  215293. */

  215294. static const char *sqlite3Fts5IterTerm(Fts5IndexIter *pIndexIter, int *pn){

  215295.   int n;

  215296.   const char *z = (const char*)fts5MultiIterTerm((Fts5Iter*)pIndexIter, &n);

  215297.   *pn = n-1;

  215298.   return &z[1];

  215299. }

  215300. 

  215301. /*

  215302. ** Close an iterator opened by an earlier call to sqlite3Fts5IndexQuery().

  215303. */

  215304. static void sqlite3Fts5IterClose(Fts5IndexIter *pIndexIter){

  215305.   if( pIndexIter ){

  215306.     Fts5Iter *pIter = (Fts5Iter*)pIndexIter;

  215307.     Fts5Index *pIndex = pIter->pIndex;

  215308.     fts5MultiIterFree(pIter);

  215309.     fts5CloseReader(pIndex);

  215310.   }

  215311. }

  215312. 

  215313. /*

  215314. ** Read and decode the "averages" record from the database. 

  215315. **

  215316. ** Parameter anSize must point to an array of size nCol, where nCol is

  215317. ** the number of user defined columns in the FTS table.

  215318. */

  215319. static int sqlite3Fts5IndexGetAverages(Fts5Index *p, i64 *pnRow, i64 *anSize){

  215320.   int nCol = p->pConfig->nCol;

  215321.   Fts5Data *pData;

  215322. 

  215323.   *pnRow = 0;

  215324.   memset(anSize, 0, sizeof(i64) * nCol);

  215325.   pData = fts5DataRead(p, FTS5_AVERAGES_ROWID);

  215326.   if( p->rc==SQLITE_OK && pData->nn ){

  215327.     int i = 0;

  215328.     int iCol;

  215329.     i += fts5GetVarint(&pData->p[i], (u64*)pnRow);

  215330.     for(iCol=0; i<pData->nn && iCol<nCol; iCol++){

  215331.       i += fts5GetVarint(&pData->p[i], (u64*)&anSize[iCol]);

  215332.     }

  215333.   }

  215334. 

  215335.   fts5DataRelease(pData);

  215336.   return fts5IndexReturn(p);

  215337. }

  215338. 

  215339. /*

  215340. ** Replace the current "averages" record with the contents of the buffer 

  215341. ** supplied as the second argument.

  215342. */

  215343. static int sqlite3Fts5IndexSetAverages(Fts5Index *p, const u8 *pData, int nData){

  215344.   assert( p->rc==SQLITE_OK );

  215345.   fts5DataWrite(p, FTS5_AVERAGES_ROWID, pData, nData);

  215346.   return fts5IndexReturn(p);

  215347. }

  215348. 

  215349. /*

  215350. ** Return the total number of blocks this module has read from the %_data

  215351. ** table since it was created.

  215352. */

  215353. static int sqlite3Fts5IndexReads(Fts5Index *p){

  215354.   return p->nRead;

  215355. }

  215356. 

  215357. /*

  215358. ** Set the 32-bit cookie value stored at the start of all structure 

  215359. ** records to the value passed as the second argument.

  215360. **

  215361. ** Return SQLITE_OK if successful, or an SQLite error code if an error

  215362. ** occurs.

  215363. */

  215364. static int sqlite3Fts5IndexSetCookie(Fts5Index *p, int iNew){

  215365.   int rc;                              /* Return code */

  215366.   Fts5Config *pConfig = p->pConfig;    /* Configuration object */

  215367.   u8 aCookie[4];                       /* Binary representation of iNew */

  215368.   sqlite3_blob *pBlob = 0;

  215369. 

  215370.   assert( p->rc==SQLITE_OK );

  215371.   sqlite3Fts5Put32(aCookie, iNew);

  215372. 

  215373.   rc = sqlite3_blob_open(pConfig->db, pConfig->zDb, p->zDataTbl, 

  215374.       "block", FTS5_STRUCTURE_ROWID, 1, &pBlob

  215375.   );

  215376.   if( rc==SQLITE_OK ){

  215377.     sqlite3_blob_write(pBlob, aCookie, 4, 0);

  215378.     rc = sqlite3_blob_close(pBlob);

  215379.   }

  215380. 

  215381.   return rc;

  215382. }

  215383. 

  215384. static int sqlite3Fts5IndexLoadConfig(Fts5Index *p){

  215385.   Fts5Structure *pStruct;

  215386.   pStruct = fts5StructureRead(p);

  215387.   fts5StructureRelease(pStruct);

  215388.   return fts5IndexReturn(p);

  215389. }

  215390. 

  215391. 

  215392. /*************************************************************************

  215393. **************************************************************************

  215394. ** Below this point is the implementation of the integrity-check 

  215395. ** functionality.

  215396. */

  215397. 

  215398. /*

  215399. ** Return a simple checksum value based on the arguments.

  215400. */

  215401. static u64 sqlite3Fts5IndexEntryCksum(

  215402.   i64 iRowid, 

  215403.   int iCol, 

  215404.   int iPos, 

  215405.   int iIdx,

  215406.   const char *pTerm,

  215407.   int nTerm

  215408. ){

  215409.   int i;

  215410.   u64 ret = iRowid;

  215411.   ret += (ret<<3) + iCol;

  215412.   ret += (ret<<3) + iPos;

  215413.   if( iIdx>=0 ) ret += (ret<<3) + (FTS5_MAIN_PREFIX + iIdx);

  215414.   for(i=0; i<nTerm; i++) ret += (ret<<3) + pTerm[i];

  215415.   return ret;

  215416. }

  215417. 

  215418. #ifdef SQLITE_DEBUG

  215419. /*

  215420. ** This function is purely an internal test. It does not contribute to 

  215421. ** FTS functionality, or even the integrity-check, in any way.

  215422. **

  215423. ** Instead, it tests that the same set of pgno/rowid combinations are 

  215424. ** visited regardless of whether the doclist-index identified by parameters

  215425. ** iSegid/iLeaf is iterated in forwards or reverse order.

  215426. */

  215427. static void fts5TestDlidxReverse(

  215428.   Fts5Index *p, 

  215429.   int iSegid,                     /* Segment id to load from */

  215430.   int iLeaf                       /* Load doclist-index for this leaf */

  215431. ){

  215432.   Fts5DlidxIter *pDlidx = 0;

  215433.   u64 cksum1 = 13;

  215434.   u64 cksum2 = 13;

  215435. 

  215436.   for(pDlidx=fts5DlidxIterInit(p, 0, iSegid, iLeaf);

  215437.       fts5DlidxIterEof(p, pDlidx)==0;

  215438.       fts5DlidxIterNext(p, pDlidx)

  215439.   ){

  215440.     i64 iRowid = fts5DlidxIterRowid(pDlidx);

  215441.     int pgno = fts5DlidxIterPgno(pDlidx);

  215442.     assert( pgno>iLeaf );

  215443.     cksum1 += iRowid + ((i64)pgno<<32);

  215444.   }

  215445.   fts5DlidxIterFree(pDlidx);

  215446.   pDlidx = 0;

  215447. 

  215448.   for(pDlidx=fts5DlidxIterInit(p, 1, iSegid, iLeaf);

  215449.       fts5DlidxIterEof(p, pDlidx)==0;

  215450.       fts5DlidxIterPrev(p, pDlidx)

  215451.   ){

  215452.     i64 iRowid = fts5DlidxIterRowid(pDlidx);

  215453.     int pgno = fts5DlidxIterPgno(pDlidx);

  215454.     assert( fts5DlidxIterPgno(pDlidx)>iLeaf );

  215455.     cksum2 += iRowid + ((i64)pgno<<32);

  215456.   }

  215457.   fts5DlidxIterFree(pDlidx);

  215458.   pDlidx = 0;

  215459. 

  215460.   if( p->rc==SQLITE_OK && cksum1!=cksum2 ) p->rc = FTS5_CORRUPT;

  215461. }

  215462. 

  215463. static int fts5QueryCksum(

  215464.   Fts5Index *p,                   /* Fts5 index object */

  215465.   int iIdx,

  215466.   const char *z,                  /* Index key to query for */

  215467.   int n,                          /* Size of index key in bytes */

  215468.   int flags,                      /* Flags for Fts5IndexQuery */

  215469.   u64 *pCksum                     /* IN/OUT: Checksum value */

  215470. ){

  215471.   int eDetail = p->pConfig->eDetail;

  215472.   u64 cksum = *pCksum;

  215473.   Fts5IndexIter *pIter = 0;

  215474.   int rc = sqlite3Fts5IndexQuery(p, z, n, flags, 0, &pIter);

  215475. 

  215476.   while( rc==SQLITE_OK && 0==sqlite3Fts5IterEof(pIter) ){

  215477.     i64 rowid = pIter->iRowid;

  215478. 

  215479.     if( eDetail==FTS5_DETAIL_NONE ){

  215480.       cksum ^= sqlite3Fts5IndexEntryCksum(rowid, 0, 0, iIdx, z, n);

  215481.     }else{

  215482.       Fts5PoslistReader sReader;

  215483.       for(sqlite3Fts5PoslistReaderInit(pIter->pData, pIter->nData, &sReader);

  215484.           sReader.bEof==0;

  215485.           sqlite3Fts5PoslistReaderNext(&sReader)

  215486.       ){

  215487.         int iCol = FTS5_POS2COLUMN(sReader.iPos);

  215488.         int iOff = FTS5_POS2OFFSET(sReader.iPos);

  215489.         cksum ^= sqlite3Fts5IndexEntryCksum(rowid, iCol, iOff, iIdx, z, n);

  215490.       }

  215491.     }

  215492.     if( rc==SQLITE_OK ){

  215493.       rc = sqlite3Fts5IterNext(pIter);

  215494.     }

  215495.   }

  215496.   sqlite3Fts5IterClose(pIter);

  215497. 

  215498.   *pCksum = cksum;

  215499.   return rc;

  215500. }

  215501. 

  215502. 

  215503. /*

  215504. ** This function is also purely an internal test. It does not contribute to 

  215505. ** FTS functionality, or even the integrity-check, in any way.

  215506. */

  215507. static void fts5TestTerm(

  215508.   Fts5Index *p, 

  215509.   Fts5Buffer *pPrev,              /* Previous term */

  215510.   const char *z, int n,           /* Possibly new term to test */

  215511.   u64 expected,

  215512.   u64 *pCksum

  215513. ){

  215514.   int rc = p->rc;

  215515.   if( pPrev->n==0 ){

  215516.     fts5BufferSet(&rc, pPrev, n, (const u8*)z);

  215517.   }else

  215518.   if( rc==SQLITE_OK && (pPrev->n!=n || memcmp(pPrev->p, z, n)) ){

  215519.     u64 cksum3 = *pCksum;

  215520.     const char *zTerm = (const char*)&pPrev->p[1];  /* term sans prefix-byte */

  215521.     int nTerm = pPrev->n-1;            /* Size of zTerm in bytes */

  215522.     int iIdx = (pPrev->p[0] - FTS5_MAIN_PREFIX);

  215523.     int flags = (iIdx==0 ? 0 : FTS5INDEX_QUERY_PREFIX);

  215524.     u64 ck1 = 0;

  215525.     u64 ck2 = 0;

  215526. 

  215527.     /* Check that the results returned for ASC and DESC queries are

  215528.     ** the same. If not, call this corruption.  */

  215529.     rc = fts5QueryCksum(p, iIdx, zTerm, nTerm, flags, &ck1);

  215530.     if( rc==SQLITE_OK ){

  215531.       int f = flags|FTS5INDEX_QUERY_DESC;

  215532.       rc = fts5QueryCksum(p, iIdx, zTerm, nTerm, f, &ck2);

  215533.     }

  215534.     if( rc==SQLITE_OK && ck1!=ck2 ) rc = FTS5_CORRUPT;

  215535. 

  215536.     /* If this is a prefix query, check that the results returned if the

  215537.     ** the index is disabled are the same. In both ASC and DESC order. 

  215538.     **

  215539.     ** This check may only be performed if the hash table is empty. This

  215540.     ** is because the hash table only supports a single scan query at

  215541.     ** a time, and the multi-iter loop from which this function is called

  215542.     ** is already performing such a scan. */

  215543.     if( p->nPendingData==0 ){

  215544.       if( iIdx>0 && rc==SQLITE_OK ){

  215545.         int f = flags|FTS5INDEX_QUERY_TEST_NOIDX;

  215546.         ck2 = 0;

  215547.         rc = fts5QueryCksum(p, iIdx, zTerm, nTerm, f, &ck2);

  215548.         if( rc==SQLITE_OK && ck1!=ck2 ) rc = FTS5_CORRUPT;

  215549.       }

  215550.       if( iIdx>0 && rc==SQLITE_OK ){

  215551.         int f = flags|FTS5INDEX_QUERY_TEST_NOIDX|FTS5INDEX_QUERY_DESC;

  215552.         ck2 = 0;

  215553.         rc = fts5QueryCksum(p, iIdx, zTerm, nTerm, f, &ck2);

  215554.         if( rc==SQLITE_OK && ck1!=ck2 ) rc = FTS5_CORRUPT;

  215555.       }

  215556.     }

  215557. 

  215558.     cksum3 ^= ck1;

  215559.     fts5BufferSet(&rc, pPrev, n, (const u8*)z);

  215560. 

  215561.     if( rc==SQLITE_OK && cksum3!=expected ){

  215562.       rc = FTS5_CORRUPT;

  215563.     }

  215564.     *pCksum = cksum3;

  215565.   }

  215566.   p->rc = rc;

  215567. }

  215568.  

  215569. #else

  215570. # define fts5TestDlidxReverse(x,y,z)

  215571. # define fts5TestTerm(u,v,w,x,y,z)

  215572. #endif

  215573. 

  215574. /*

  215575. ** Check that:

  215576. **

  215577. **   1) All leaves of pSeg between iFirst and iLast (inclusive) exist and

  215578. **      contain zero terms.

  215579. **   2) All leaves of pSeg between iNoRowid and iLast (inclusive) exist and

  215580. **      contain zero rowids.

  215581. */

  215582. static void fts5IndexIntegrityCheckEmpty(

  215583.   Fts5Index *p,

  215584.   Fts5StructureSegment *pSeg,     /* Segment to check internal consistency */

  215585.   int iFirst,

  215586.   int iNoRowid,

  215587.   int iLast

  215588. ){

  215589.   int i;

  215590. 

  215591.   /* Now check that the iter.nEmpty leaves following the current leaf

  215592.   ** (a) exist and (b) contain no terms. */

  215593.   for(i=iFirst; p->rc==SQLITE_OK && i<=iLast; i++){

  215594.     Fts5Data *pLeaf = fts5DataRead(p, FTS5_SEGMENT_ROWID(pSeg->iSegid, i));

  215595.     if( pLeaf ){

  215596.       if( !fts5LeafIsTermless(pLeaf) ) p->rc = FTS5_CORRUPT;

  215597.       if( i>=iNoRowid && 0!=fts5LeafFirstRowidOff(pLeaf) ) p->rc = FTS5_CORRUPT;

  215598.     }

  215599.     fts5DataRelease(pLeaf);

  215600.   }

  215601. }

  215602. 

  215603. static void fts5IntegrityCheckPgidx(Fts5Index *p, Fts5Data *pLeaf){

  215604.   int iTermOff = 0;

  215605.   int ii;

  215606. 

  215607.   Fts5Buffer buf1 = {0,0,0};

  215608.   Fts5Buffer buf2 = {0,0,0};

  215609. 

  215610.   ii = pLeaf->szLeaf;

  215611.   while( ii<pLeaf->nn && p->rc==SQLITE_OK ){

  215612.     int res;

  215613.     int iOff;

  215614.     int nIncr;

  215615. 

  215616.     ii += fts5GetVarint32(&pLeaf->p[ii], nIncr);

  215617.     iTermOff += nIncr;

  215618.     iOff = iTermOff;

  215619. 

  215620.     if( iOff>=pLeaf->szLeaf ){

  215621.       p->rc = FTS5_CORRUPT;

  215622.     }else if( iTermOff==nIncr ){

  215623.       int nByte;

  215624.       iOff += fts5GetVarint32(&pLeaf->p[iOff], nByte);

  215625.       if( (iOff+nByte)>pLeaf->szLeaf ){

  215626.         p->rc = FTS5_CORRUPT;

  215627.       }else{

  215628.         fts5BufferSet(&p->rc, &buf1, nByte, &pLeaf->p[iOff]);

  215629.       }

  215630.     }else{

  215631.       int nKeep, nByte;

  215632.       iOff += fts5GetVarint32(&pLeaf->p[iOff], nKeep);

  215633.       iOff += fts5GetVarint32(&pLeaf->p[iOff], nByte);

  215634.       if( nKeep>buf1.n || (iOff+nByte)>pLeaf->szLeaf ){

  215635.         p->rc = FTS5_CORRUPT;

  215636.       }else{

  215637.         buf1.n = nKeep;

  215638.         fts5BufferAppendBlob(&p->rc, &buf1, nByte, &pLeaf->p[iOff]);

  215639.       }

  215640. 

  215641.       if( p->rc==SQLITE_OK ){

  215642.         res = fts5BufferCompare(&buf1, &buf2);

  215643.         if( res<=0 ) p->rc = FTS5_CORRUPT;

  215644.       }

  215645.     }

  215646.     fts5BufferSet(&p->rc, &buf2, buf1.n, buf1.p);

  215647.   }

  215648. 

  215649.   fts5BufferFree(&buf1);

  215650.   fts5BufferFree(&buf2);

  215651. }

  215652. 

  215653. static void fts5IndexIntegrityCheckSegment(

  215654.   Fts5Index *p,                   /* FTS5 backend object */

  215655.   Fts5StructureSegment *pSeg      /* Segment to check internal consistency */

  215656. ){

  215657.   Fts5Config *pConfig = p->pConfig;

  215658.   sqlite3_stmt *pStmt = 0;

  215659.   int rc2;

  215660.   int iIdxPrevLeaf = pSeg->pgnoFirst-1;

  215661.   int iDlidxPrevLeaf = pSeg->pgnoLast;

  215662. 

  215663.   if( pSeg->pgnoFirst==0 ) return;

  215664. 

  215665.   fts5IndexPrepareStmt(p, &pStmt, sqlite3_mprintf(

  215666.       "SELECT segid, term, (pgno>>1), (pgno&1) FROM %Q.'%q_idx' WHERE segid=%d",

  215667.       pConfig->zDb, pConfig->zName, pSeg->iSegid

  215668.   ));

  215669. 

  215670.   /* Iterate through the b-tree hierarchy.  */

  215671.   while( p->rc==SQLITE_OK && SQLITE_ROW==sqlite3_step(pStmt) ){

  215672.     i64 iRow;                     /* Rowid for this leaf */

  215673.     Fts5Data *pLeaf;              /* Data for this leaf */

  215674. 

  215675.     int nIdxTerm = sqlite3_column_bytes(pStmt, 1);

  215676.     const char *zIdxTerm = (const char*)sqlite3_column_text(pStmt, 1);

  215677.     int iIdxLeaf = sqlite3_column_int(pStmt, 2);

  215678.     int bIdxDlidx = sqlite3_column_int(pStmt, 3);

  215679. 

  215680.     /* If the leaf in question has already been trimmed from the segment, 

  215681.     ** ignore this b-tree entry. Otherwise, load it into memory. */

  215682.     if( iIdxLeaf<pSeg->pgnoFirst ) continue;

  215683.     iRow = FTS5_SEGMENT_ROWID(pSeg->iSegid, iIdxLeaf);

  215684.     pLeaf = fts5LeafRead(p, iRow);

  215685.     if( pLeaf==0 ) break;

  215686. 

  215687.     /* Check that the leaf contains at least one term, and that it is equal

  215688.     ** to or larger than the split-key in zIdxTerm.  Also check that if there

  215689.     ** is also a rowid pointer within the leaf page header, it points to a

  215690.     ** location before the term.  */

  215691.     if( pLeaf->nn<=pLeaf->szLeaf ){

  215692.       p->rc = FTS5_CORRUPT;

  215693.     }else{

  215694.       int iOff;                   /* Offset of first term on leaf */

  215695.       int iRowidOff;              /* Offset of first rowid on leaf */

  215696.       int nTerm;                  /* Size of term on leaf in bytes */

  215697.       int res;                    /* Comparison of term and split-key */

  215698. 

  215699.       iOff = fts5LeafFirstTermOff(pLeaf);

  215700.       iRowidOff = fts5LeafFirstRowidOff(pLeaf);

  215701.       if( iRowidOff>=iOff || iOff>=pLeaf->szLeaf ){

  215702.         p->rc = FTS5_CORRUPT;

  215703.       }else{

  215704.         iOff += fts5GetVarint32(&pLeaf->p[iOff], nTerm);

  215705.         res = fts5Memcmp(&pLeaf->p[iOff], zIdxTerm, MIN(nTerm, nIdxTerm));

  215706.         if( res==0 ) res = nTerm - nIdxTerm;

  215707.         if( res<0 ) p->rc = FTS5_CORRUPT;

  215708.       }

  215709. 

  215710.       fts5IntegrityCheckPgidx(p, pLeaf);

  215711.     }

  215712.     fts5DataRelease(pLeaf);

  215713.     if( p->rc ) break;

  215714. 

  215715.     /* Now check that the iter.nEmpty leaves following the current leaf

  215716.     ** (a) exist and (b) contain no terms. */

  215717.     fts5IndexIntegrityCheckEmpty(

  215718.         p, pSeg, iIdxPrevLeaf+1, iDlidxPrevLeaf+1, iIdxLeaf-1

  215719.     );

  215720.     if( p->rc ) break;

  215721. 

  215722.     /* If there is a doclist-index, check that it looks right. */

  215723.     if( bIdxDlidx ){

  215724.       Fts5DlidxIter *pDlidx = 0;  /* For iterating through doclist index */

  215725.       int iPrevLeaf = iIdxLeaf;

  215726.       int iSegid = pSeg->iSegid;

  215727.       int iPg = 0;

  215728.       i64 iKey;

  215729. 

  215730.       for(pDlidx=fts5DlidxIterInit(p, 0, iSegid, iIdxLeaf);

  215731.           fts5DlidxIterEof(p, pDlidx)==0;

  215732.           fts5DlidxIterNext(p, pDlidx)

  215733.       ){

  215734. 

  215735.         /* Check any rowid-less pages that occur before the current leaf. */

  215736.         for(iPg=iPrevLeaf+1; iPg<fts5DlidxIterPgno(pDlidx); iPg++){

  215737.           iKey = FTS5_SEGMENT_ROWID(iSegid, iPg);

  215738.           pLeaf = fts5DataRead(p, iKey);

  215739.           if( pLeaf ){

  215740.             if( fts5LeafFirstRowidOff(pLeaf)!=0 ) p->rc = FTS5_CORRUPT;

  215741.             fts5DataRelease(pLeaf);

  215742.           }

  215743.         }

  215744.         iPrevLeaf = fts5DlidxIterPgno(pDlidx);

  215745. 

  215746.         /* Check that the leaf page indicated by the iterator really does

  215747.         ** contain the rowid suggested by the same. */

  215748.         iKey = FTS5_SEGMENT_ROWID(iSegid, iPrevLeaf);

  215749.         pLeaf = fts5DataRead(p, iKey);

  215750.         if( pLeaf ){

  215751.           i64 iRowid;

  215752.           int iRowidOff = fts5LeafFirstRowidOff(pLeaf);

  215753.           ASSERT_SZLEAF_OK(pLeaf);

  215754.           if( iRowidOff>=pLeaf->szLeaf ){

  215755.             p->rc = FTS5_CORRUPT;

  215756.           }else{

  215757.             fts5GetVarint(&pLeaf->p[iRowidOff], (u64*)&iRowid);

  215758.             if( iRowid!=fts5DlidxIterRowid(pDlidx) ) p->rc = FTS5_CORRUPT;

  215759.           }

  215760.           fts5DataRelease(pLeaf);

  215761.         }

  215762.       }

  215763. 

  215764.       iDlidxPrevLeaf = iPg;

  215765.       fts5DlidxIterFree(pDlidx);

  215766.       fts5TestDlidxReverse(p, iSegid, iIdxLeaf);

  215767.     }else{

  215768.       iDlidxPrevLeaf = pSeg->pgnoLast;

  215769.       /* TODO: Check there is no doclist index */

  215770.     }

  215771. 

  215772.     iIdxPrevLeaf = iIdxLeaf;

  215773.   }

  215774. 

  215775.   rc2 = sqlite3_finalize(pStmt);

  215776.   if( p->rc==SQLITE_OK ) p->rc = rc2;

  215777. 

  215778.   /* Page iter.iLeaf must now be the rightmost leaf-page in the segment */

  215779. #if 0

  215780.   if( p->rc==SQLITE_OK && iter.iLeaf!=pSeg->pgnoLast ){

  215781.     p->rc = FTS5_CORRUPT;

  215782.   }

  215783. #endif

  215784. }

  215785. 

  215786. 

  215787. /*

  215788. ** Run internal checks to ensure that the FTS index (a) is internally 

  215789. ** consistent and (b) contains entries for which the XOR of the checksums

  215790. ** as calculated by sqlite3Fts5IndexEntryCksum() is cksum.

  215791. **

  215792. ** Return SQLITE_CORRUPT if any of the internal checks fail, or if the

  215793. ** checksum does not match. Return SQLITE_OK if all checks pass without

  215794. ** error, or some other SQLite error code if another error (e.g. OOM)

  215795. ** occurs.

  215796. */

  215797. static int sqlite3Fts5IndexIntegrityCheck(Fts5Index *p, u64 cksum){

  215798.   int eDetail = p->pConfig->eDetail;

  215799.   u64 cksum2 = 0;                 /* Checksum based on contents of indexes */

  215800.   Fts5Buffer poslist = {0,0,0};   /* Buffer used to hold a poslist */

  215801.   Fts5Iter *pIter;                /* Used to iterate through entire index */

  215802.   Fts5Structure *pStruct;         /* Index structure */

  215803. 

  215804. #ifdef SQLITE_DEBUG

  215805.   /* Used by extra internal tests only run if NDEBUG is not defined */

  215806.   u64 cksum3 = 0;                 /* Checksum based on contents of indexes */

  215807.   Fts5Buffer term = {0,0,0};      /* Buffer used to hold most recent term */

  215808. #endif

  215809.   const int flags = FTS5INDEX_QUERY_NOOUTPUT;

  215810.   

  215811.   /* Load the FTS index structure */

  215812.   pStruct = fts5StructureRead(p);

  215813. 

  215814.   /* Check that the internal nodes of each segment match the leaves */

  215815.   if( pStruct ){

  215816.     int iLvl, iSeg;

  215817.     for(iLvl=0; iLvl<pStruct->nLevel; iLvl++){

  215818.       for(iSeg=0; iSeg<pStruct->aLevel[iLvl].nSeg; iSeg++){

  215819.         Fts5StructureSegment *pSeg = &pStruct->aLevel[iLvl].aSeg[iSeg];

  215820.         fts5IndexIntegrityCheckSegment(p, pSeg);

  215821.       }

  215822.     }

  215823.   }

  215824. 

  215825.   /* The cksum argument passed to this function is a checksum calculated

  215826.   ** based on all expected entries in the FTS index (including prefix index

  215827.   ** entries). This block checks that a checksum calculated based on the

  215828.   ** actual contents of FTS index is identical.

  215829.   **

  215830.   ** Two versions of the same checksum are calculated. The first (stack

  215831.   ** variable cksum2) based on entries extracted from the full-text index

  215832.   ** while doing a linear scan of each individual index in turn. 

  215833.   **

  215834.   ** As each term visited by the linear scans, a separate query for the

  215835.   ** same term is performed. cksum3 is calculated based on the entries

  215836.   ** extracted by these queries.

  215837.   */

  215838.   for(fts5MultiIterNew(p, pStruct, flags, 0, 0, 0, -1, 0, &pIter);

  215839.       fts5MultiIterEof(p, pIter)==0;

  215840.       fts5MultiIterNext(p, pIter, 0, 0)

  215841.   ){

  215842.     int n;                      /* Size of term in bytes */

  215843.     i64 iPos = 0;               /* Position read from poslist */

  215844.     int iOff = 0;               /* Offset within poslist */

  215845.     i64 iRowid = fts5MultiIterRowid(pIter);

  215846.     char *z = (char*)fts5MultiIterTerm(pIter, &n);

  215847. 

  215848.     /* If this is a new term, query for it. Update cksum3 with the results. */

  215849.     fts5TestTerm(p, &term, z, n, cksum2, &cksum3);

  215850. 

  215851.     if( eDetail==FTS5_DETAIL_NONE ){

  215852.       if( 0==fts5MultiIterIsEmpty(p, pIter) ){

  215853.         cksum2 ^= sqlite3Fts5IndexEntryCksum(iRowid, 0, 0, -1, z, n);

  215854.       }

  215855.     }else{

  215856.       poslist.n = 0;

  215857.       fts5SegiterPoslist(p, &pIter->aSeg[pIter->aFirst[1].iFirst], 0, &poslist);

  215858.       while( 0==sqlite3Fts5PoslistNext64(poslist.p, poslist.n, &iOff, &iPos) ){

  215859.         int iCol = FTS5_POS2COLUMN(iPos);

  215860.         int iTokOff = FTS5_POS2OFFSET(iPos);

  215861.         cksum2 ^= sqlite3Fts5IndexEntryCksum(iRowid, iCol, iTokOff, -1, z, n);

  215862.       }

  215863.     }

  215864.   }

  215865.   fts5TestTerm(p, &term, 0, 0, cksum2, &cksum3);

  215866. 

  215867.   fts5MultiIterFree(pIter);

  215868.   if( p->rc==SQLITE_OK && cksum!=cksum2 ) p->rc = FTS5_CORRUPT;

  215869. 

  215870.   fts5StructureRelease(pStruct);

  215871. #ifdef SQLITE_DEBUG

  215872.   fts5BufferFree(&term);

  215873. #endif

  215874.   fts5BufferFree(&poslist);

  215875.   return fts5IndexReturn(p);

  215876. }

  215877. 

  215878. /*************************************************************************

  215879. **************************************************************************

  215880. ** Below this point is the implementation of the fts5_decode() scalar

  215881. ** function only.

  215882. */

  215883. 

  215884. /*

  215885. ** Decode a segment-data rowid from the %_data table. This function is

  215886. ** the opposite of macro FTS5_SEGMENT_ROWID().

  215887. */

  215888. static void fts5DecodeRowid(

  215889.   i64 iRowid,                     /* Rowid from %_data table */

  215890.   int *piSegid,                   /* OUT: Segment id */

  215891.   int *pbDlidx,                   /* OUT: Dlidx flag */

  215892.   int *piHeight,                  /* OUT: Height */

  215893.   int *piPgno                     /* OUT: Page number */

  215894. ){

  215895.   *piPgno = (int)(iRowid & (((i64)1 << FTS5_DATA_PAGE_B) - 1));

  215896.   iRowid >>= FTS5_DATA_PAGE_B;

  215897. 

  215898.   *piHeight = (int)(iRowid & (((i64)1 << FTS5_DATA_HEIGHT_B) - 1));

  215899.   iRowid >>= FTS5_DATA_HEIGHT_B;

  215900. 

  215901.   *pbDlidx = (int)(iRowid & 0x0001);

  215902.   iRowid >>= FTS5_DATA_DLI_B;

  215903. 

  215904.   *piSegid = (int)(iRowid & (((i64)1 << FTS5_DATA_ID_B) - 1));

  215905. }

  215906. 

  215907. static void fts5DebugRowid(int *pRc, Fts5Buffer *pBuf, i64 iKey){

  215908.   int iSegid, iHeight, iPgno, bDlidx;       /* Rowid compenents */

  215909.   fts5DecodeRowid(iKey, &iSegid, &bDlidx, &iHeight, &iPgno);

  215910. 

  215911.   if( iSegid==0 ){

  215912.     if( iKey==FTS5_AVERAGES_ROWID ){

  215913.       sqlite3Fts5BufferAppendPrintf(pRc, pBuf, "{averages} ");

  215914.     }else{

  215915.       sqlite3Fts5BufferAppendPrintf(pRc, pBuf, "{structure}");

  215916.     }

  215917.   }

  215918.   else{

  215919.     sqlite3Fts5BufferAppendPrintf(pRc, pBuf, "{%ssegid=%d h=%d pgno=%d}",

  215920.         bDlidx ? "dlidx " : "", iSegid, iHeight, iPgno

  215921.     );

  215922.   }

  215923. }

  215924. 

  215925. static void fts5DebugStructure(

  215926.   int *pRc,                       /* IN/OUT: error code */

  215927.   Fts5Buffer *pBuf,

  215928.   Fts5Structure *p

  215929. ){

  215930.   int iLvl, iSeg;                 /* Iterate through levels, segments */

  215931. 

  215932.   for(iLvl=0; iLvl<p->nLevel; iLvl++){

  215933.     Fts5StructureLevel *pLvl = &p->aLevel[iLvl];

  215934.     sqlite3Fts5BufferAppendPrintf(pRc, pBuf, 

  215935.         " {lvl=%d nMerge=%d nSeg=%d", iLvl, pLvl->nMerge, pLvl->nSeg

  215936.     );

  215937.     for(iSeg=0; iSeg<pLvl->nSeg; iSeg++){

  215938.       Fts5StructureSegment *pSeg = &pLvl->aSeg[iSeg];

  215939.       sqlite3Fts5BufferAppendPrintf(pRc, pBuf, " {id=%d leaves=%d..%d}", 

  215940.           pSeg->iSegid, pSeg->pgnoFirst, pSeg->pgnoLast

  215941.       );

  215942.     }

  215943.     sqlite3Fts5BufferAppendPrintf(pRc, pBuf, "}");

  215944.   }

  215945. }

  215946. 

  215947. /*

  215948. ** This is part of the fts5_decode() debugging aid.

  215949. **

  215950. ** Arguments pBlob/nBlob contain a serialized Fts5Structure object. This

  215951. ** function appends a human-readable representation of the same object

  215952. ** to the buffer passed as the second argument. 

  215953. */

  215954. static void fts5DecodeStructure(

  215955.   int *pRc,                       /* IN/OUT: error code */

  215956.   Fts5Buffer *pBuf,

  215957.   const u8 *pBlob, int nBlob

  215958. ){

  215959.   int rc;                         /* Return code */

  215960.   Fts5Structure *p = 0;           /* Decoded structure object */

  215961. 

  215962.   rc = fts5StructureDecode(pBlob, nBlob, 0, &p);

  215963.   if( rc!=SQLITE_OK ){

  215964.     *pRc = rc;

  215965.     return;

  215966.   }

  215967. 

  215968.   fts5DebugStructure(pRc, pBuf, p);

  215969.   fts5StructureRelease(p);

  215970. }

  215971. 

  215972. /*

  215973. ** This is part of the fts5_decode() debugging aid.

  215974. **

  215975. ** Arguments pBlob/nBlob contain an "averages" record. This function 

  215976. ** appends a human-readable representation of record to the buffer passed 

  215977. ** as the second argument. 

  215978. */

  215979. static void fts5DecodeAverages(

  215980.   int *pRc,                       /* IN/OUT: error code */

  215981.   Fts5Buffer *pBuf,

  215982.   const u8 *pBlob, int nBlob

  215983. ){

  215984.   int i = 0;

  215985.   const char *zSpace = "";

  215986. 

  215987.   while( i<nBlob ){

  215988.     u64 iVal;

  215989.     i += sqlite3Fts5GetVarint(&pBlob[i], &iVal);

  215990.     sqlite3Fts5BufferAppendPrintf(pRc, pBuf, "%s%d", zSpace, (int)iVal);

  215991.     zSpace = " ";

  215992.   }

  215993. }

  215994. 

  215995. /*

  215996. ** Buffer (a/n) is assumed to contain a list of serialized varints. Read

  215997. ** each varint and append its string representation to buffer pBuf. Return

  215998. ** after either the input buffer is exhausted or a 0 value is read.

  215999. **

  216000. ** The return value is the number of bytes read from the input buffer.

  216001. */

  216002. static int fts5DecodePoslist(int *pRc, Fts5Buffer *pBuf, const u8 *a, int n){

  216003.   int iOff = 0;

  216004.   while( iOff<n ){

  216005.     int iVal;

  216006.     iOff += fts5GetVarint32(&a[iOff], iVal);

  216007.     sqlite3Fts5BufferAppendPrintf(pRc, pBuf, " %d", iVal);

  216008.   }

  216009.   return iOff;

  216010. }

  216011. 

  216012. /*

  216013. ** The start of buffer (a/n) contains the start of a doclist. The doclist

  216014. ** may or may not finish within the buffer. This function appends a text

  216015. ** representation of the part of the doclist that is present to buffer

  216016. ** pBuf. 

  216017. **

  216018. ** The return value is the number of bytes read from the input buffer.

  216019. */

  216020. static int fts5DecodeDoclist(int *pRc, Fts5Buffer *pBuf, const u8 *a, int n){

  216021.   i64 iDocid = 0;

  216022.   int iOff = 0;

  216023. 

  216024.   if( n>0 ){

  216025.     iOff = sqlite3Fts5GetVarint(a, (u64*)&iDocid);

  216026.     sqlite3Fts5BufferAppendPrintf(pRc, pBuf, " id=%lld", iDocid);

  216027.   }

  216028.   while( iOff<n ){

  216029.     int nPos;

  216030.     int bDel;

  216031.     iOff += fts5GetPoslistSize(&a[iOff], &nPos, &bDel);

  216032.     sqlite3Fts5BufferAppendPrintf(pRc, pBuf, " nPos=%d%s", nPos, bDel?"*":"");

  216033.     iOff += fts5DecodePoslist(pRc, pBuf, &a[iOff], MIN(n-iOff, nPos));

  216034.     if( iOff<n ){

  216035.       i64 iDelta;

  216036.       iOff += sqlite3Fts5GetVarint(&a[iOff], (u64*)&iDelta);

  216037.       iDocid += iDelta;

  216038.       sqlite3Fts5BufferAppendPrintf(pRc, pBuf, " id=%lld", iDocid);

  216039.     }

  216040.   }

  216041. 

  216042.   return iOff;

  216043. }

  216044. 

  216045. /*

  216046. ** This function is part of the fts5_decode() debugging function. It is 

  216047. ** only ever used with detail=none tables.

  216048. **

  216049. ** Buffer (pData/nData) contains a doclist in the format used by detail=none

  216050. ** tables. This function appends a human-readable version of that list to

  216051. ** buffer pBuf.

  216052. **

  216053. ** If *pRc is other than SQLITE_OK when this function is called, it is a

  216054. ** no-op. If an OOM or other error occurs within this function, *pRc is

  216055. ** set to an SQLite error code before returning. The final state of buffer

  216056. ** pBuf is undefined in this case.

  216057. */

  216058. static void fts5DecodeRowidList(

  216059.   int *pRc,                       /* IN/OUT: Error code */

  216060.   Fts5Buffer *pBuf,               /* Buffer to append text to */

  216061.   const u8 *pData, int nData      /* Data to decode list-of-rowids from */

  216062. ){

  216063.   int i = 0;

  216064.   i64 iRowid = 0;

  216065. 

  216066.   while( i<nData ){

  216067.     const char *zApp = "";

  216068.     u64 iVal;

  216069.     i += sqlite3Fts5GetVarint(&pData[i], &iVal);

  216070.     iRowid += iVal;

  216071. 

  216072.     if( i<nData && pData[i]==0x00 ){

  216073.       i++;

  216074.       if( i<nData && pData[i]==0x00 ){

  216075.         i++;

  216076.         zApp = "+";

  216077.       }else{

  216078.         zApp = "*";

  216079.       }

  216080.     }

  216081. 

  216082.     sqlite3Fts5BufferAppendPrintf(pRc, pBuf, " %lld%s", iRowid, zApp);

  216083.   }

  216084. }

  216085. 

  216086. /*

  216087. ** The implementation of user-defined scalar function fts5_decode().

  216088. */

  216089. static void fts5DecodeFunction(

  216090.   sqlite3_context *pCtx,          /* Function call context */

  216091.   int nArg,                       /* Number of args (always 2) */

  216092.   sqlite3_value **apVal           /* Function arguments */

  216093. ){

  216094.   i64 iRowid;                     /* Rowid for record being decoded */

  216095.   int iSegid,iHeight,iPgno,bDlidx;/* Rowid components */

  216096.   const u8 *aBlob; int n;         /* Record to decode */

  216097.   u8 *a = 0;

  216098.   Fts5Buffer s;                   /* Build up text to return here */

  216099.   int rc = SQLITE_OK;             /* Return code */

  216100.   sqlite3_int64 nSpace = 0;

  216101.   int eDetailNone = (sqlite3_user_data(pCtx)!=0);

  216102. 

  216103.   assert( nArg==2 );

  216104.   UNUSED_PARAM(nArg);

  216105.   memset(&s, 0, sizeof(Fts5Buffer));

  216106.   iRowid = sqlite3_value_int64(apVal[0]);

  216107. 

  216108.   /* Make a copy of the second argument (a blob) in aBlob[]. The aBlob[]

  216109.   ** copy is followed by FTS5_DATA_ZERO_PADDING 0x00 bytes, which prevents

  216110.   ** buffer overreads even if the record is corrupt.  */

  216111.   n = sqlite3_value_bytes(apVal[1]);

  216112.   aBlob = sqlite3_value_blob(apVal[1]);

  216113.   nSpace = n + FTS5_DATA_ZERO_PADDING;

  216114.   a = (u8*)sqlite3Fts5MallocZero(&rc, nSpace);

  216115.   if( a==0 ) goto decode_out;

  216116.   if( n>0 ) memcpy(a, aBlob, n);

  216117. 

  216118.   fts5DecodeRowid(iRowid, &iSegid, &bDlidx, &iHeight, &iPgno);

  216119. 

  216120.   fts5DebugRowid(&rc, &s, iRowid);

  216121.   if( bDlidx ){

  216122.     Fts5Data dlidx;

  216123.     Fts5DlidxLvl lvl;

  216124. 

  216125.     dlidx.p = a;

  216126.     dlidx.nn = n;

  216127. 

  216128.     memset(&lvl, 0, sizeof(Fts5DlidxLvl));

  216129.     lvl.pData = &dlidx;

  216130.     lvl.iLeafPgno = iPgno;

  216131. 

  216132.     for(fts5DlidxLvlNext(&lvl); lvl.bEof==0; fts5DlidxLvlNext(&lvl)){

  216133.       sqlite3Fts5BufferAppendPrintf(&rc, &s, 

  216134.           " %d(%lld)", lvl.iLeafPgno, lvl.iRowid

  216135.       );

  216136.     }

  216137.   }else if( iSegid==0 ){

  216138.     if( iRowid==FTS5_AVERAGES_ROWID ){

  216139.       fts5DecodeAverages(&rc, &s, a, n);

  216140.     }else{

  216141.       fts5DecodeStructure(&rc, &s, a, n);

  216142.     }

  216143.   }else if( eDetailNone ){

  216144.     Fts5Buffer term;              /* Current term read from page */

  216145.     int szLeaf;

  216146.     int iPgidxOff = szLeaf = fts5GetU16(&a[2]);

  216147.     int iTermOff;

  216148.     int nKeep = 0;

  216149.     int iOff;

  216150. 

  216151.     memset(&term, 0, sizeof(Fts5Buffer));

  216152. 

  216153.     /* Decode any entries that occur before the first term. */

  216154.     if( szLeaf<n ){

  216155.       iPgidxOff += fts5GetVarint32(&a[iPgidxOff], iTermOff);

  216156.     }else{

  216157.       iTermOff = szLeaf;

  216158.     }

  216159.     fts5DecodeRowidList(&rc, &s, &a[4], iTermOff-4);

  216160. 

  216161.     iOff = iTermOff;

  216162.     while( iOff<szLeaf ){

  216163.       int nAppend;

  216164. 

  216165.       /* Read the term data for the next term*/

  216166.       iOff += fts5GetVarint32(&a[iOff], nAppend);

  216167.       term.n = nKeep;

  216168.       fts5BufferAppendBlob(&rc, &term, nAppend, &a[iOff]);

  216169.       sqlite3Fts5BufferAppendPrintf(

  216170.           &rc, &s, " term=%.*s", term.n, (const char*)term.p

  216171.       );

  216172.       iOff += nAppend;

  216173. 

  216174.       /* Figure out where the doclist for this term ends */

  216175.       if( iPgidxOff<n ){

  216176.         int nIncr;

  216177.         iPgidxOff += fts5GetVarint32(&a[iPgidxOff], nIncr);

  216178.         iTermOff += nIncr;

  216179.       }else{

  216180.         iTermOff = szLeaf;

  216181.       }

  216182. 

  216183.       fts5DecodeRowidList(&rc, &s, &a[iOff], iTermOff-iOff);

  216184.       iOff = iTermOff;

  216185.       if( iOff<szLeaf ){

  216186.         iOff += fts5GetVarint32(&a[iOff], nKeep);

  216187.       }

  216188.     }

  216189. 

  216190.     fts5BufferFree(&term);

  216191.   }else{

  216192.     Fts5Buffer term;              /* Current term read from page */

  216193.     int szLeaf;                   /* Offset of pgidx in a[] */

  216194.     int iPgidxOff;

  216195.     int iPgidxPrev = 0;           /* Previous value read from pgidx */

  216196.     int iTermOff = 0;

  216197.     int iRowidOff = 0;

  216198.     int iOff;

  216199.     int nDoclist;

  216200. 

  216201.     memset(&term, 0, sizeof(Fts5Buffer));

  216202. 

  216203.     if( n<4 ){

  216204.       sqlite3Fts5BufferSet(&rc, &s, 7, (const u8*)"corrupt");

  216205.       goto decode_out;

  216206.     }else{

  216207.       iRowidOff = fts5GetU16(&a[0]);

  216208.       iPgidxOff = szLeaf = fts5GetU16(&a[2]);

  216209.       if( iPgidxOff<n ){

  216210.         fts5GetVarint32(&a[iPgidxOff], iTermOff);

  216211.       }else if( iPgidxOff>n ){

  216212.         rc = FTS5_CORRUPT;

  216213.         goto decode_out;

  216214.       }

  216215.     }

  216216. 

  216217.     /* Decode the position list tail at the start of the page */

  216218.     if( iRowidOff!=0 ){

  216219.       iOff = iRowidOff;

  216220.     }else if( iTermOff!=0 ){

  216221.       iOff = iTermOff;

  216222.     }else{

  216223.       iOff = szLeaf;

  216224.     }

  216225.     if( iOff>n ){

  216226.       rc = FTS5_CORRUPT;

  216227.       goto decode_out;

  216228.     }

  216229.     fts5DecodePoslist(&rc, &s, &a[4], iOff-4);

  216230. 

  216231.     /* Decode any more doclist data that appears on the page before the

  216232.     ** first term. */

  216233.     nDoclist = (iTermOff ? iTermOff : szLeaf) - iOff;

  216234.     if( nDoclist+iOff>n ){

  216235.       rc = FTS5_CORRUPT;

  216236.       goto decode_out;

  216237.     }

  216238.     fts5DecodeDoclist(&rc, &s, &a[iOff], nDoclist);

  216239. 

  216240.     while( iPgidxOff<n && rc==SQLITE_OK ){

  216241.       int bFirst = (iPgidxOff==szLeaf);     /* True for first term on page */

  216242.       int nByte;                            /* Bytes of data */

  216243.       int iEnd;

  216244.       

  216245.       iPgidxOff += fts5GetVarint32(&a[iPgidxOff], nByte);

  216246.       iPgidxPrev += nByte;

  216247.       iOff = iPgidxPrev;

  216248. 

  216249.       if( iPgidxOff<n ){

  216250.         fts5GetVarint32(&a[iPgidxOff], nByte);

  216251.         iEnd = iPgidxPrev + nByte;

  216252.       }else{

  216253.         iEnd = szLeaf;

  216254.       }

  216255.       if( iEnd>szLeaf ){

  216256.         rc = FTS5_CORRUPT;

  216257.         break;

  216258.       }

  216259. 

  216260.       if( bFirst==0 ){

  216261.         iOff += fts5GetVarint32(&a[iOff], nByte);

  216262.         if( nByte>term.n ){

  216263.           rc = FTS5_CORRUPT;

  216264.           break;

  216265.         }

  216266.         term.n = nByte;

  216267.       }

  216268.       iOff += fts5GetVarint32(&a[iOff], nByte);

  216269.       if( iOff+nByte>n ){

  216270.         rc = FTS5_CORRUPT;

  216271.         break;

  216272.       }

  216273.       fts5BufferAppendBlob(&rc, &term, nByte, &a[iOff]);

  216274.       iOff += nByte;

  216275. 

  216276.       sqlite3Fts5BufferAppendPrintf(

  216277.           &rc, &s, " term=%.*s", term.n, (const char*)term.p

  216278.       );

  216279.       iOff += fts5DecodeDoclist(&rc, &s, &a[iOff], iEnd-iOff);

  216280.     }

  216281. 

  216282.     fts5BufferFree(&term);

  216283.   }

  216284.   

  216285.  decode_out:

  216286.   sqlite3_free(a);

  216287.   if( rc==SQLITE_OK ){

  216288.     sqlite3_result_text(pCtx, (const char*)s.p, s.n, SQLITE_TRANSIENT);

  216289.   }else{

  216290.     sqlite3_result_error_code(pCtx, rc);

  216291.   }

  216292.   fts5BufferFree(&s);

  216293. }

  216294. 

  216295. /*

  216296. ** The implementation of user-defined scalar function fts5_rowid().

  216297. */

  216298. static void fts5RowidFunction(

  216299.   sqlite3_context *pCtx,          /* Function call context */

  216300.   int nArg,                       /* Number of args (always 2) */

  216301.   sqlite3_value **apVal           /* Function arguments */

  216302. ){

  216303.   const char *zArg;

  216304.   if( nArg==0 ){

  216305.     sqlite3_result_error(pCtx, "should be: fts5_rowid(subject, ....)", -1);

  216306.   }else{

  216307.     zArg = (const char*)sqlite3_value_text(apVal[0]);

  216308.     if( 0==sqlite3_stricmp(zArg, "segment") ){

  216309.       i64 iRowid;

  216310.       int segid, pgno;

  216311.       if( nArg!=3 ){

  216312.         sqlite3_result_error(pCtx, 

  216313.             "should be: fts5_rowid('segment', segid, pgno))", -1

  216314.         );

  216315.       }else{

  216316.         segid = sqlite3_value_int(apVal[1]);

  216317.         pgno = sqlite3_value_int(apVal[2]);

  216318.         iRowid = FTS5_SEGMENT_ROWID(segid, pgno);

  216319.         sqlite3_result_int64(pCtx, iRowid);

  216320.       }

  216321.     }else{

  216322.       sqlite3_result_error(pCtx, 

  216323.         "first arg to fts5_rowid() must be 'segment'" , -1

  216324.       );

  216325.     }

  216326.   }

  216327. }

  216328. 

  216329. /*

  216330. ** This is called as part of registering the FTS5 module with database

  216331. ** connection db. It registers several user-defined scalar functions useful

  216332. ** with FTS5.

  216333. **

  216334. ** If successful, SQLITE_OK is returned. If an error occurs, some other

  216335. ** SQLite error code is returned instead.

  216336. */

  216337. static int sqlite3Fts5IndexInit(sqlite3 *db){

  216338.   int rc = sqlite3_create_function(

  216339.       db, "fts5_decode", 2, SQLITE_UTF8, 0, fts5DecodeFunction, 0, 0

  216340.   );

  216341. 

  216342.   if( rc==SQLITE_OK ){

  216343.     rc = sqlite3_create_function(

  216344.         db, "fts5_decode_none", 2, 

  216345.         SQLITE_UTF8, (void*)db, fts5DecodeFunction, 0, 0

  216346.     );

  216347.   }

  216348. 

  216349.   if( rc==SQLITE_OK ){

  216350.     rc = sqlite3_create_function(

  216351.         db, "fts5_rowid", -1, SQLITE_UTF8, 0, fts5RowidFunction, 0, 0

  216352.     );

  216353.   }

  216354.   return rc;

  216355. }

  216356. 

  216357. 

  216358. static int sqlite3Fts5IndexReset(Fts5Index *p){

  216359.   assert( p->pStruct==0 || p->iStructVersion!=0 );

  216360.   if( fts5IndexDataVersion(p)!=p->iStructVersion ){

  216361.     fts5StructureInvalidate(p);

  216362.   }

  216363.   return fts5IndexReturn(p);

  216364. }

  216365. 

  216366. /*

  216367. ** 2014 Jun 09

  216368. **

  216369. ** The author disclaims copyright to this source code.  In place of

  216370. ** a legal notice, here is a blessing:

  216371. **

  216372. **    May you do good and not evil.

  216373. **    May you find forgiveness for yourself and forgive others.

  216374. **    May you share freely, never taking more than you give.

  216375. **

  216376. ******************************************************************************

  216377. **

  216378. ** This is an SQLite module implementing full-text search.

  216379. */

  216380. 

  216381. 

  216382. /* #include "fts5Int.h" */

  216383. 

  216384. /*

  216385. ** This variable is set to false when running tests for which the on disk

  216386. ** structures should not be corrupt. Otherwise, true. If it is false, extra

  216387. ** assert() conditions in the fts5 code are activated - conditions that are

  216388. ** only true if it is guaranteed that the fts5 database is not corrupt.

  216389. */

  216390. SQLITE_API int sqlite3_fts5_may_be_corrupt = 1;

  216391. 

  216392. 

  216393. typedef struct Fts5Auxdata Fts5Auxdata;

  216394. typedef struct Fts5Auxiliary Fts5Auxiliary;

  216395. typedef struct Fts5Cursor Fts5Cursor;

  216396. typedef struct Fts5FullTable Fts5FullTable;

  216397. typedef struct Fts5Sorter Fts5Sorter;

  216398. typedef struct Fts5TokenizerModule Fts5TokenizerModule;

  216399. 

  216400. /*

  216401. ** NOTES ON TRANSACTIONS: 

  216402. **

  216403. ** SQLite invokes the following virtual table methods as transactions are 

  216404. ** opened and closed by the user:

  216405. **

  216406. **     xBegin():    Start of a new transaction.

  216407. **     xSync():     Initial part of two-phase commit.

  216408. **     xCommit():   Final part of two-phase commit.

  216409. **     xRollback(): Rollback the transaction.

  216410. **

  216411. ** Anything that is required as part of a commit that may fail is performed

  216412. ** in the xSync() callback. Current versions of SQLite ignore any errors 

  216413. ** returned by xCommit().

  216414. **

  216415. ** And as sub-transactions are opened/closed:

  216416. **

  216417. **     xSavepoint(int S):  Open savepoint S.

  216418. **     xRelease(int S):    Commit and close savepoint S.

  216419. **     xRollbackTo(int S): Rollback to start of savepoint S.

  216420. **

  216421. ** During a write-transaction the fts5_index.c module may cache some data 

  216422. ** in-memory. It is flushed to disk whenever xSync(), xRelease() or

  216423. ** xSavepoint() is called. And discarded whenever xRollback() or xRollbackTo() 

  216424. ** is called.

  216425. **

  216426. ** Additionally, if SQLITE_DEBUG is defined, an instance of the following

  216427. ** structure is used to record the current transaction state. This information

  216428. ** is not required, but it is used in the assert() statements executed by

  216429. ** function fts5CheckTransactionState() (see below).

  216430. */

  216431. struct Fts5TransactionState {

  216432.   int eState;                     /* 0==closed, 1==open, 2==synced */

  216433.   int iSavepoint;                 /* Number of open savepoints (0 -> none) */

  216434. };

  216435. 

  216436. /*

  216437. ** A single object of this type is allocated when the FTS5 module is 

  216438. ** registered with a database handle. It is used to store pointers to

  216439. ** all registered FTS5 extensions - tokenizers and auxiliary functions.

  216440. */

  216441. struct Fts5Global {

  216442.   fts5_api api;                   /* User visible part of object (see fts5.h) */

  216443.   sqlite3 *db;                    /* Associated database connection */ 

  216444.   i64 iNextId;                    /* Used to allocate unique cursor ids */

  216445.   Fts5Auxiliary *pAux;            /* First in list of all aux. functions */

  216446.   Fts5TokenizerModule *pTok;      /* First in list of all tokenizer modules */

  216447.   Fts5TokenizerModule *pDfltTok;  /* Default tokenizer module */

  216448.   Fts5Cursor *pCsr;               /* First in list of all open cursors */

  216449. };

  216450. 

  216451. /*

  216452. ** Each auxiliary function registered with the FTS5 module is represented

  216453. ** by an object of the following type. All such objects are stored as part

  216454. ** of the Fts5Global.pAux list.

  216455. */

  216456. struct Fts5Auxiliary {

  216457.   Fts5Global *pGlobal;            /* Global context for this function */

  216458.   char *zFunc;                    /* Function name (nul-terminated) */

  216459.   void *pUserData;                /* User-data pointer */

  216460.   fts5_extension_function xFunc;  /* Callback function */

  216461.   void (*xDestroy)(void*);        /* Destructor function */

  216462.   Fts5Auxiliary *pNext;           /* Next registered auxiliary function */

  216463. };

  216464. 

  216465. /*

  216466. ** Each tokenizer module registered with the FTS5 module is represented

  216467. ** by an object of the following type. All such objects are stored as part

  216468. ** of the Fts5Global.pTok list.

  216469. */

  216470. struct Fts5TokenizerModule {

  216471.   char *zName;                    /* Name of tokenizer */

  216472.   void *pUserData;                /* User pointer passed to xCreate() */

  216473.   fts5_tokenizer x;               /* Tokenizer functions */

  216474.   void (*xDestroy)(void*);        /* Destructor function */

  216475.   Fts5TokenizerModule *pNext;     /* Next registered tokenizer module */

  216476. };

  216477. 

  216478. struct Fts5FullTable {

  216479.   Fts5Table p;                    /* Public class members from fts5Int.h */

  216480.   Fts5Storage *pStorage;          /* Document store */

  216481.   Fts5Global *pGlobal;            /* Global (connection wide) data */

  216482.   Fts5Cursor *pSortCsr;           /* Sort data from this cursor */

  216483. #ifdef SQLITE_DEBUG

  216484.   struct Fts5TransactionState ts;

  216485. #endif

  216486. };

  216487. 

  216488. struct Fts5MatchPhrase {

  216489.   Fts5Buffer *pPoslist;           /* Pointer to current poslist */

  216490.   int nTerm;                      /* Size of phrase in terms */

  216491. };

  216492. 

  216493. /*

  216494. ** pStmt:

  216495. **   SELECT rowid, <fts> FROM <fts> ORDER BY +rank;

  216496. **

  216497. ** aIdx[]:

  216498. **   There is one entry in the aIdx[] array for each phrase in the query,

  216499. **   the value of which is the offset within aPoslist[] following the last 

  216500. **   byte of the position list for the corresponding phrase.

  216501. */

  216502. struct Fts5Sorter {

  216503.   sqlite3_stmt *pStmt;

  216504.   i64 iRowid;                     /* Current rowid */

  216505.   const u8 *aPoslist;             /* Position lists for current row */

  216506.   int nIdx;                       /* Number of entries in aIdx[] */

  216507.   int aIdx[1];                    /* Offsets into aPoslist for current row */

  216508. };

  216509. 

  216510. 

  216511. /*

  216512. ** Virtual-table cursor object.

  216513. **

  216514. ** iSpecial:

  216515. **   If this is a 'special' query (refer to function fts5SpecialMatch()), 

  216516. **   then this variable contains the result of the query. 

  216517. **

  216518. ** iFirstRowid, iLastRowid:

  216519. **   These variables are only used for FTS5_PLAN_MATCH cursors. Assuming the

  216520. **   cursor iterates in ascending order of rowids, iFirstRowid is the lower

  216521. **   limit of rowids to return, and iLastRowid the upper. In other words, the

  216522. **   WHERE clause in the user's query might have been:

  216523. **

  216524. **       <tbl> MATCH <expr> AND rowid BETWEEN $iFirstRowid AND $iLastRowid

  216525. **

  216526. **   If the cursor iterates in descending order of rowid, iFirstRowid

  216527. **   is the upper limit (i.e. the "first" rowid visited) and iLastRowid

  216528. **   the lower.

  216529. */

  216530. struct Fts5Cursor {

  216531.   sqlite3_vtab_cursor base;       /* Base class used by SQLite core */

  216532.   Fts5Cursor *pNext;              /* Next cursor in Fts5Cursor.pCsr list */

  216533.   int *aColumnSize;               /* Values for xColumnSize() */

  216534.   i64 iCsrId;                     /* Cursor id */

  216535. 

  216536.   /* Zero from this point onwards on cursor reset */

  216537.   int ePlan;                      /* FTS5_PLAN_XXX value */

  216538.   int bDesc;                      /* True for "ORDER BY rowid DESC" queries */

  216539.   i64 iFirstRowid;                /* Return no rowids earlier than this */

  216540.   i64 iLastRowid;                 /* Return no rowids later than this */

  216541.   sqlite3_stmt *pStmt;            /* Statement used to read %_content */

  216542.   Fts5Expr *pExpr;                /* Expression for MATCH queries */

  216543.   Fts5Sorter *pSorter;            /* Sorter for "ORDER BY rank" queries */

  216544.   int csrflags;                   /* Mask of cursor flags (see below) */

  216545.   i64 iSpecial;                   /* Result of special query */

  216546. 

  216547.   /* "rank" function. Populated on demand from vtab.xColumn(). */

  216548.   char *zRank;                    /* Custom rank function */

  216549.   char *zRankArgs;                /* Custom rank function args */

  216550.   Fts5Auxiliary *pRank;           /* Rank callback (or NULL) */

  216551.   int nRankArg;                   /* Number of trailing arguments for rank() */

  216552.   sqlite3_value **apRankArg;      /* Array of trailing arguments */

  216553.   sqlite3_stmt *pRankArgStmt;     /* Origin of objects in apRankArg[] */

  216554. 

  216555.   /* Auxiliary data storage */

  216556.   Fts5Auxiliary *pAux;            /* Currently executing extension function */

  216557.   Fts5Auxdata *pAuxdata;          /* First in linked list of saved aux-data */

  216558. 

  216559.   /* Cache used by auxiliary functions xInst() and xInstCount() */

  216560.   Fts5PoslistReader *aInstIter;   /* One for each phrase */

  216561.   int nInstAlloc;                 /* Size of aInst[] array (entries / 3) */

  216562.   int nInstCount;                 /* Number of phrase instances */

  216563.   int *aInst;                     /* 3 integers per phrase instance */

  216564. };

  216565. 

  216566. /*

  216567. ** Bits that make up the "idxNum" parameter passed indirectly by 

  216568. ** xBestIndex() to xFilter().

  216569. */

  216570. #define FTS5_BI_MATCH        0x0001         /* <tbl> MATCH ? */

  216571. #define FTS5_BI_RANK         0x0002         /* rank MATCH ? */

  216572. #define FTS5_BI_ROWID_EQ     0x0004         /* rowid == ? */

  216573. #define FTS5_BI_ROWID_LE     0x0008         /* rowid <= ? */

  216574. #define FTS5_BI_ROWID_GE     0x0010         /* rowid >= ? */

  216575. 

  216576. #define FTS5_BI_ORDER_RANK   0x0020

  216577. #define FTS5_BI_ORDER_ROWID  0x0040

  216578. #define FTS5_BI_ORDER_DESC   0x0080

  216579. 

  216580. /*

  216581. ** Values for Fts5Cursor.csrflags

  216582. */

  216583. #define FTS5CSR_EOF               0x01

  216584. #define FTS5CSR_REQUIRE_CONTENT   0x02

  216585. #define FTS5CSR_REQUIRE_DOCSIZE   0x04

  216586. #define FTS5CSR_REQUIRE_INST      0x08

  216587. #define FTS5CSR_FREE_ZRANK        0x10

  216588. #define FTS5CSR_REQUIRE_RESEEK    0x20

  216589. #define FTS5CSR_REQUIRE_POSLIST   0x40

  216590. 

  216591. #define BitFlagAllTest(x,y) (((x) & (y))==(y))

  216592. #define BitFlagTest(x,y)    (((x) & (y))!=0)

  216593. 

  216594. 

  216595. /*

  216596. ** Macros to Set(), Clear() and Test() cursor flags.

  216597. */

  216598. #define CsrFlagSet(pCsr, flag)   ((pCsr)->csrflags |= (flag))

  216599. #define CsrFlagClear(pCsr, flag) ((pCsr)->csrflags &= ~(flag))

  216600. #define CsrFlagTest(pCsr, flag)  ((pCsr)->csrflags & (flag))

  216601. 

  216602. struct Fts5Auxdata {

  216603.   Fts5Auxiliary *pAux;            /* Extension to which this belongs */

  216604.   void *pPtr;                     /* Pointer value */

  216605.   void(*xDelete)(void*);          /* Destructor */

  216606.   Fts5Auxdata *pNext;             /* Next object in linked list */

  216607. };

  216608. 

  216609. #ifdef SQLITE_DEBUG

  216610. #define FTS5_BEGIN      1

  216611. #define FTS5_SYNC       2

  216612. #define FTS5_COMMIT     3

  216613. #define FTS5_ROLLBACK   4

  216614. #define FTS5_SAVEPOINT  5

  216615. #define FTS5_RELEASE    6

  216616. #define FTS5_ROLLBACKTO 7

  216617. static void fts5CheckTransactionState(Fts5FullTable *p, int op, int iSavepoint){

  216618.   switch( op ){

  216619.     case FTS5_BEGIN:

  216620.       assert( p->ts.eState==0 );

  216621.       p->ts.eState = 1;

  216622.       p->ts.iSavepoint = -1;

  216623.       break;

  216624. 

  216625.     case FTS5_SYNC:

  216626.       assert( p->ts.eState==1 );

  216627.       p->ts.eState = 2;

  216628.       break;

  216629. 

  216630.     case FTS5_COMMIT:

  216631.       assert( p->ts.eState==2 );

  216632.       p->ts.eState = 0;

  216633.       break;

  216634. 

  216635.     case FTS5_ROLLBACK:

  216636.       assert( p->ts.eState==1 || p->ts.eState==2 || p->ts.eState==0 );

  216637.       p->ts.eState = 0;

  216638.       break;

  216639. 

  216640.     case FTS5_SAVEPOINT:

  216641.       assert( p->ts.eState==1 );

  216642.       assert( iSavepoint>=0 );

  216643.       assert( iSavepoint>=p->ts.iSavepoint );

  216644.       p->ts.iSavepoint = iSavepoint;

  216645.       break;

  216646.       

  216647.     case FTS5_RELEASE:

  216648.       assert( p->ts.eState==1 );

  216649.       assert( iSavepoint>=0 );

  216650.       assert( iSavepoint<=p->ts.iSavepoint );

  216651.       p->ts.iSavepoint = iSavepoint-1;

  216652.       break;

  216653. 

  216654.     case FTS5_ROLLBACKTO:

  216655.       assert( p->ts.eState==1 );

  216656.       assert( iSavepoint>=-1 );

  216657.       assert( iSavepoint<=p->ts.iSavepoint );

  216658.       p->ts.iSavepoint = iSavepoint;

  216659.       break;

  216660.   }

  216661. }

  216662. #else

  216663. # define fts5CheckTransactionState(x,y,z)

  216664. #endif

  216665. 

  216666. /*

  216667. ** Return true if pTab is a contentless table.

  216668. */

  216669. static int fts5IsContentless(Fts5FullTable *pTab){

  216670.   return pTab->p.pConfig->eContent==FTS5_CONTENT_NONE;

  216671. }

  216672. 

  216673. /*

  216674. ** Delete a virtual table handle allocated by fts5InitVtab(). 

  216675. */

  216676. static void fts5FreeVtab(Fts5FullTable *pTab){

  216677.   if( pTab ){

  216678.     sqlite3Fts5IndexClose(pTab->p.pIndex);

  216679.     sqlite3Fts5StorageClose(pTab->pStorage);

  216680.     sqlite3Fts5ConfigFree(pTab->p.pConfig);

  216681.     sqlite3_free(pTab);

  216682.   }

  216683. }

  216684. 

  216685. /*

  216686. ** The xDisconnect() virtual table method.

  216687. */

  216688. static int fts5DisconnectMethod(sqlite3_vtab *pVtab){

  216689.   fts5FreeVtab((Fts5FullTable*)pVtab);

  216690.   return SQLITE_OK;

  216691. }

  216692. 

  216693. /*

  216694. ** The xDestroy() virtual table method.

  216695. */

  216696. static int fts5DestroyMethod(sqlite3_vtab *pVtab){

  216697.   Fts5Table *pTab = (Fts5Table*)pVtab;

  216698.   int rc = sqlite3Fts5DropAll(pTab->pConfig);

  216699.   if( rc==SQLITE_OK ){

  216700.     fts5FreeVtab((Fts5FullTable*)pVtab);

  216701.   }

  216702.   return rc;

  216703. }

  216704. 

  216705. /*

  216706. ** This function is the implementation of both the xConnect and xCreate

  216707. ** methods of the FTS3 virtual table.

  216708. **

  216709. ** The argv[] array contains the following:

  216710. **

  216711. **   argv[0]   -> module name  ("fts5")

  216712. **   argv[1]   -> database name

  216713. **   argv[2]   -> table name

  216714. **   argv[...] -> "column name" and other module argument fields.

  216715. */

  216716. static int fts5InitVtab(

  216717.   int bCreate,                    /* True for xCreate, false for xConnect */

  216718.   sqlite3 *db,                    /* The SQLite database connection */

  216719.   void *pAux,                     /* Hash table containing tokenizers */

  216720.   int argc,                       /* Number of elements in argv array */

  216721.   const char * const *argv,       /* xCreate/xConnect argument array */

  216722.   sqlite3_vtab **ppVTab,          /* Write the resulting vtab structure here */

  216723.   char **pzErr                    /* Write any error message here */

  216724. ){

  216725.   Fts5Global *pGlobal = (Fts5Global*)pAux;

  216726.   const char **azConfig = (const char**)argv;

  216727.   int rc = SQLITE_OK;             /* Return code */

  216728.   Fts5Config *pConfig = 0;        /* Results of parsing argc/argv */

  216729.   Fts5FullTable *pTab = 0;        /* New virtual table object */

  216730. 

  216731.   /* Allocate the new vtab object and parse the configuration */

  216732.   pTab = (Fts5FullTable*)sqlite3Fts5MallocZero(&rc, sizeof(Fts5FullTable));

  216733.   if( rc==SQLITE_OK ){

  216734.     rc = sqlite3Fts5ConfigParse(pGlobal, db, argc, azConfig, &pConfig, pzErr);

  216735.     assert( (rc==SQLITE_OK && *pzErr==0) || pConfig==0 );

  216736.   }

  216737.   if( rc==SQLITE_OK ){

  216738.     pTab->p.pConfig = pConfig;

  216739.     pTab->pGlobal = pGlobal;

  216740.   }

  216741. 

  216742.   /* Open the index sub-system */

  216743.   if( rc==SQLITE_OK ){

  216744.     rc = sqlite3Fts5IndexOpen(pConfig, bCreate, &pTab->p.pIndex, pzErr);

  216745.   }

  216746. 

  216747.   /* Open the storage sub-system */

  216748.   if( rc==SQLITE_OK ){

  216749.     rc = sqlite3Fts5StorageOpen(

  216750.         pConfig, pTab->p.pIndex, bCreate, &pTab->pStorage, pzErr

  216751.     );

  216752.   }

  216753. 

  216754.   /* Call sqlite3_declare_vtab() */

  216755.   if( rc==SQLITE_OK ){

  216756.     rc = sqlite3Fts5ConfigDeclareVtab(pConfig);

  216757.   }

  216758. 

  216759.   /* Load the initial configuration */

  216760.   if( rc==SQLITE_OK ){

  216761.     assert( pConfig->pzErrmsg==0 );

  216762.     pConfig->pzErrmsg = pzErr;

  216763.     rc = sqlite3Fts5IndexLoadConfig(pTab->p.pIndex);

  216764.     sqlite3Fts5IndexRollback(pTab->p.pIndex);

  216765.     pConfig->pzErrmsg = 0;

  216766.   }

  216767. 

  216768.   if( rc!=SQLITE_OK ){

  216769.     fts5FreeVtab(pTab);

  216770.     pTab = 0;

  216771.   }else if( bCreate ){

  216772.     fts5CheckTransactionState(pTab, FTS5_BEGIN, 0);

  216773.   }

  216774.   *ppVTab = (sqlite3_vtab*)pTab;

  216775.   return rc;

  216776. }

  216777. 

  216778. /*

  216779. ** The xConnect() and xCreate() methods for the virtual table. All the

  216780. ** work is done in function fts5InitVtab().

  216781. */

  216782. static int fts5ConnectMethod(

  216783.   sqlite3 *db,                    /* Database connection */

  216784.   void *pAux,                     /* Pointer to tokenizer hash table */

  216785.   int argc,                       /* Number of elements in argv array */

  216786.   const char * const *argv,       /* xCreate/xConnect argument array */

  216787.   sqlite3_vtab **ppVtab,          /* OUT: New sqlite3_vtab object */

  216788.   char **pzErr                    /* OUT: sqlite3_malloc'd error message */

  216789. ){

  216790.   return fts5InitVtab(0, db, pAux, argc, argv, ppVtab, pzErr);

  216791. }

  216792. static int fts5CreateMethod(

  216793.   sqlite3 *db,                    /* Database connection */

  216794.   void *pAux,                     /* Pointer to tokenizer hash table */

  216795.   int argc,                       /* Number of elements in argv array */

  216796.   const char * const *argv,       /* xCreate/xConnect argument array */

  216797.   sqlite3_vtab **ppVtab,          /* OUT: New sqlite3_vtab object */

  216798.   char **pzErr                    /* OUT: sqlite3_malloc'd error message */

  216799. ){

  216800.   return fts5InitVtab(1, db, pAux, argc, argv, ppVtab, pzErr);

  216801. }

  216802. 

  216803. /*

  216804. ** The different query plans.

  216805. */

  216806. #define FTS5_PLAN_MATCH          1       /* (<tbl> MATCH ?) */

  216807. #define FTS5_PLAN_SOURCE         2       /* A source cursor for SORTED_MATCH */

  216808. #define FTS5_PLAN_SPECIAL        3       /* An internal query */

  216809. #define FTS5_PLAN_SORTED_MATCH   4       /* (<tbl> MATCH ? ORDER BY rank) */

  216810. #define FTS5_PLAN_SCAN           5       /* No usable constraint */

  216811. #define FTS5_PLAN_ROWID          6       /* (rowid = ?) */

  216812. 

  216813. /*

  216814. ** Set the SQLITE_INDEX_SCAN_UNIQUE flag in pIdxInfo->flags. Unless this

  216815. ** extension is currently being used by a version of SQLite too old to

  216816. ** support index-info flags. In that case this function is a no-op.

  216817. */

  216818. static void fts5SetUniqueFlag(sqlite3_index_info *pIdxInfo){

  216819. #if SQLITE_VERSION_NUMBER>=3008012

  216820. #ifndef SQLITE_CORE

  216821.   if( sqlite3_libversion_number()>=3008012 )

  216822. #endif

  216823.   {

  216824.     pIdxInfo->idxFlags |= SQLITE_INDEX_SCAN_UNIQUE;

  216825.   }

  216826. #endif

  216827. }

  216828. 

  216829. /*

  216830. ** Implementation of the xBestIndex method for FTS5 tables. Within the 

  216831. ** WHERE constraint, it searches for the following:

  216832. **

  216833. **   1. A MATCH constraint against the special column.

  216834. **   2. A MATCH constraint against the "rank" column.

  216835. **   3. An == constraint against the rowid column.

  216836. **   4. A < or <= constraint against the rowid column.

  216837. **   5. A > or >= constraint against the rowid column.

  216838. **

  216839. ** Within the ORDER BY, either:

  216840. **

  216841. **   5. ORDER BY rank [ASC|DESC]

  216842. **   6. ORDER BY rowid [ASC|DESC]

  216843. **

  216844. ** Costs are assigned as follows:

  216845. **

  216846. **  a) If an unusable MATCH operator is present in the WHERE clause, the

  216847. **     cost is unconditionally set to 1e50 (a really big number).

  216848. **

  216849. **  a) If a MATCH operator is present, the cost depends on the other

  216850. **     constraints also present. As follows:

  216851. **

  216852. **       * No other constraints:         cost=1000.0

  216853. **       * One rowid range constraint:   cost=750.0

  216854. **       * Both rowid range constraints: cost=500.0

  216855. **       * An == rowid constraint:       cost=100.0

  216856. **

  216857. **  b) Otherwise, if there is no MATCH:

  216858. **

  216859. **       * No other constraints:         cost=1000000.0

  216860. **       * One rowid range constraint:   cost=750000.0

  216861. **       * Both rowid range constraints: cost=250000.0

  216862. **       * An == rowid constraint:       cost=10.0

  216863. **

  216864. ** Costs are not modified by the ORDER BY clause.

  216865. */

  216866. static int fts5BestIndexMethod(sqlite3_vtab *pVTab, sqlite3_index_info *pInfo){

  216867.   Fts5Table *pTab = (Fts5Table*)pVTab;

  216868.   Fts5Config *pConfig = pTab->pConfig;

  216869.   const int nCol = pConfig->nCol;

  216870.   int idxFlags = 0;               /* Parameter passed through to xFilter() */

  216871.   int bHasMatch;

  216872.   int iNext;

  216873.   int i;

  216874. 

  216875.   struct Constraint {

  216876.     int op;                       /* Mask against sqlite3_index_constraint.op */

  216877.     int fts5op;                   /* FTS5 mask for idxFlags */

  216878.     int iCol;                     /* 0==rowid, 1==tbl, 2==rank */

  216879.     int omit;                     /* True to omit this if found */

  216880.     int iConsIndex;               /* Index in pInfo->aConstraint[] */

  216881.   } aConstraint[] = {

  216882.     {SQLITE_INDEX_CONSTRAINT_MATCH|SQLITE_INDEX_CONSTRAINT_EQ, 

  216883.                                     FTS5_BI_MATCH,    1, 1, -1},

  216884.     {SQLITE_INDEX_CONSTRAINT_MATCH|SQLITE_INDEX_CONSTRAINT_EQ, 

  216885.                                     FTS5_BI_RANK,     2, 1, -1},

  216886.     {SQLITE_INDEX_CONSTRAINT_EQ,    FTS5_BI_ROWID_EQ, 0, 0, -1},

  216887.     {SQLITE_INDEX_CONSTRAINT_LT|SQLITE_INDEX_CONSTRAINT_LE, 

  216888.                                     FTS5_BI_ROWID_LE, 0, 0, -1},

  216889.     {SQLITE_INDEX_CONSTRAINT_GT|SQLITE_INDEX_CONSTRAINT_GE, 

  216890.                                     FTS5_BI_ROWID_GE, 0, 0, -1},

  216891.   };

  216892. 

  216893.   int aColMap[3];

  216894.   aColMap[0] = -1;

  216895.   aColMap[1] = nCol;

  216896.   aColMap[2] = nCol+1;

  216897. 

  216898.   assert( SQLITE_INDEX_CONSTRAINT_EQ<SQLITE_INDEX_CONSTRAINT_MATCH );

  216899.   assert( SQLITE_INDEX_CONSTRAINT_GT<SQLITE_INDEX_CONSTRAINT_MATCH );

  216900.   assert( SQLITE_INDEX_CONSTRAINT_LE<SQLITE_INDEX_CONSTRAINT_MATCH );

  216901.   assert( SQLITE_INDEX_CONSTRAINT_GE<SQLITE_INDEX_CONSTRAINT_MATCH );

  216902.   assert( SQLITE_INDEX_CONSTRAINT_LE<SQLITE_INDEX_CONSTRAINT_MATCH );

  216903. 

  216904.   /* Set idxFlags flags for all WHERE clause terms that will be used. */

  216905.   for(i=0; i<pInfo->nConstraint; i++){

  216906.     struct sqlite3_index_constraint *p = &pInfo->aConstraint[i];

  216907.     int iCol = p->iColumn;

  216908. 

  216909.     if( (p->op==SQLITE_INDEX_CONSTRAINT_MATCH && iCol>=0 && iCol<=nCol)

  216910.      || (p->op==SQLITE_INDEX_CONSTRAINT_EQ && iCol==nCol)

  216911.     ){

  216912.       /* A MATCH operator or equivalent */

  216913.       if( p->usable ){

  216914.         idxFlags = (idxFlags & 0xFFFF) | FTS5_BI_MATCH | (iCol << 16);

  216915.         aConstraint[0].iConsIndex = i;

  216916.       }else{

  216917.         /* As there exists an unusable MATCH constraint this is an 

  216918.         ** unusable plan. Set a prohibitively high cost. */

  216919.         pInfo->estimatedCost = 1e50;

  216920.         return SQLITE_OK;

  216921.       }

  216922.     }else if( p->op<=SQLITE_INDEX_CONSTRAINT_MATCH ){

  216923.       int j;

  216924.       for(j=1; j<ArraySize(aConstraint); j++){

  216925.         struct Constraint *pC = &aConstraint[j];

  216926.         if( iCol==aColMap[pC->iCol] && (p->op & pC->op) && p->usable ){

  216927.           pC->iConsIndex = i;

  216928.           idxFlags |= pC->fts5op;

  216929.         }

  216930.       }

  216931.     }

  216932.   }

  216933. 

  216934.   /* Set idxFlags flags for the ORDER BY clause */

  216935.   if( pInfo->nOrderBy==1 ){

  216936.     int iSort = pInfo->aOrderBy[0].iColumn;

  216937.     if( iSort==(pConfig->nCol+1) && BitFlagTest(idxFlags, FTS5_BI_MATCH) ){

  216938.       idxFlags |= FTS5_BI_ORDER_RANK;

  216939.     }else if( iSort==-1 ){

  216940.       idxFlags |= FTS5_BI_ORDER_ROWID;

  216941.     }

  216942.     if( BitFlagTest(idxFlags, FTS5_BI_ORDER_RANK|FTS5_BI_ORDER_ROWID) ){

  216943.       pInfo->orderByConsumed = 1;

  216944.       if( pInfo->aOrderBy[0].desc ){

  216945.         idxFlags |= FTS5_BI_ORDER_DESC;

  216946.       }

  216947.     }

  216948.   }

  216949. 

  216950.   /* Calculate the estimated cost based on the flags set in idxFlags. */

  216951.   bHasMatch = BitFlagTest(idxFlags, FTS5_BI_MATCH);

  216952.   if( BitFlagTest(idxFlags, FTS5_BI_ROWID_EQ) ){

  216953.     pInfo->estimatedCost = bHasMatch ? 100.0 : 10.0;

  216954.     if( bHasMatch==0 ) fts5SetUniqueFlag(pInfo);

  216955.   }else if( BitFlagAllTest(idxFlags, FTS5_BI_ROWID_LE|FTS5_BI_ROWID_GE) ){

  216956.     pInfo->estimatedCost = bHasMatch ? 500.0 : 250000.0;

  216957.   }else if( BitFlagTest(idxFlags, FTS5_BI_ROWID_LE|FTS5_BI_ROWID_GE) ){

  216958.     pInfo->estimatedCost = bHasMatch ? 750.0 : 750000.0;

  216959.   }else{

  216960.     pInfo->estimatedCost = bHasMatch ? 1000.0 : 1000000.0;

  216961.   }

  216962. 

  216963.   /* Assign argvIndex values to each constraint in use. */

  216964.   iNext = 1;

  216965.   for(i=0; i<ArraySize(aConstraint); i++){

  216966.     struct Constraint *pC = &aConstraint[i];

  216967.     if( pC->iConsIndex>=0 ){

  216968.       pInfo->aConstraintUsage[pC->iConsIndex].argvIndex = iNext++;

  216969.       pInfo->aConstraintUsage[pC->iConsIndex].omit = (unsigned char)pC->omit;

  216970.     }

  216971.   }

  216972. 

  216973.   pInfo->idxNum = idxFlags;

  216974.   return SQLITE_OK;

  216975. }

  216976. 

  216977. static int fts5NewTransaction(Fts5FullTable *pTab){

  216978.   Fts5Cursor *pCsr;

  216979.   for(pCsr=pTab->pGlobal->pCsr; pCsr; pCsr=pCsr->pNext){

  216980.     if( pCsr->base.pVtab==(sqlite3_vtab*)pTab ) return SQLITE_OK;

  216981.   }

  216982.   return sqlite3Fts5StorageReset(pTab->pStorage);

  216983. }

  216984. 

  216985. /*

  216986. ** Implementation of xOpen method.

  216987. */

  216988. static int fts5OpenMethod(sqlite3_vtab *pVTab, sqlite3_vtab_cursor **ppCsr){

  216989.   Fts5FullTable *pTab = (Fts5FullTable*)pVTab;

  216990.   Fts5Config *pConfig = pTab->p.pConfig;

  216991.   Fts5Cursor *pCsr = 0;           /* New cursor object */

  216992.   sqlite3_int64 nByte;            /* Bytes of space to allocate */

  216993.   int rc;                         /* Return code */

  216994. 

  216995.   rc = fts5NewTransaction(pTab);

  216996.   if( rc==SQLITE_OK ){

  216997.     nByte = sizeof(Fts5Cursor) + pConfig->nCol * sizeof(int);

  216998.     pCsr = (Fts5Cursor*)sqlite3_malloc64(nByte);

  216999.     if( pCsr ){

  217000.       Fts5Global *pGlobal = pTab->pGlobal;

  217001.       memset(pCsr, 0, (size_t)nByte);

  217002.       pCsr->aColumnSize = (int*)&pCsr[1];

  217003.       pCsr->pNext = pGlobal->pCsr;

  217004.       pGlobal->pCsr = pCsr;

  217005.       pCsr->iCsrId = ++pGlobal->iNextId;

  217006.     }else{

  217007.       rc = SQLITE_NOMEM;

  217008.     }

  217009.   }

  217010.   *ppCsr = (sqlite3_vtab_cursor*)pCsr;

  217011.   return rc;

  217012. }

  217013. 

  217014. static int fts5StmtType(Fts5Cursor *pCsr){

  217015.   if( pCsr->ePlan==FTS5_PLAN_SCAN ){

  217016.     return (pCsr->bDesc) ? FTS5_STMT_SCAN_DESC : FTS5_STMT_SCAN_ASC;

  217017.   }

  217018.   return FTS5_STMT_LOOKUP;

  217019. }

  217020. 

  217021. /*

  217022. ** This function is called after the cursor passed as the only argument

  217023. ** is moved to point at a different row. It clears all cached data 

  217024. ** specific to the previous row stored by the cursor object.

  217025. */

  217026. static void fts5CsrNewrow(Fts5Cursor *pCsr){

  217027.   CsrFlagSet(pCsr, 

  217028.       FTS5CSR_REQUIRE_CONTENT 

  217029.     | FTS5CSR_REQUIRE_DOCSIZE 

  217030.     | FTS5CSR_REQUIRE_INST 

  217031.     | FTS5CSR_REQUIRE_POSLIST 

  217032.   );

  217033. }

  217034. 

  217035. static void fts5FreeCursorComponents(Fts5Cursor *pCsr){

  217036.   Fts5FullTable *pTab = (Fts5FullTable*)(pCsr->base.pVtab);

  217037.   Fts5Auxdata *pData;

  217038.   Fts5Auxdata *pNext;

  217039. 

  217040.   sqlite3_free(pCsr->aInstIter);

  217041.   sqlite3_free(pCsr->aInst);

  217042.   if( pCsr->pStmt ){

  217043.     int eStmt = fts5StmtType(pCsr);

  217044.     sqlite3Fts5StorageStmtRelease(pTab->pStorage, eStmt, pCsr->pStmt);

  217045.   }

  217046.   if( pCsr->pSorter ){

  217047.     Fts5Sorter *pSorter = pCsr->pSorter;

  217048.     sqlite3_finalize(pSorter->pStmt);

  217049.     sqlite3_free(pSorter);

  217050.   }

  217051. 

  217052.   if( pCsr->ePlan!=FTS5_PLAN_SOURCE ){

  217053.     sqlite3Fts5ExprFree(pCsr->pExpr);

  217054.   }

  217055. 

  217056.   for(pData=pCsr->pAuxdata; pData; pData=pNext){

  217057.     pNext = pData->pNext;

  217058.     if( pData->xDelete ) pData->xDelete(pData->pPtr);

  217059.     sqlite3_free(pData);

  217060.   }

  217061. 

  217062.   sqlite3_finalize(pCsr->pRankArgStmt);

  217063.   sqlite3_free(pCsr->apRankArg);

  217064. 

  217065.   if( CsrFlagTest(pCsr, FTS5CSR_FREE_ZRANK) ){

  217066.     sqlite3_free(pCsr->zRank);

  217067.     sqlite3_free(pCsr->zRankArgs);

  217068.   }

  217069. 

  217070.   memset(&pCsr->ePlan, 0, sizeof(Fts5Cursor) - ((u8*)&pCsr->ePlan - (u8*)pCsr));

  217071. }

  217072. 

  217073. 

  217074. /*

  217075. ** Close the cursor.  For additional information see the documentation

  217076. ** on the xClose method of the virtual table interface.

  217077. */

  217078. static int fts5CloseMethod(sqlite3_vtab_cursor *pCursor){

  217079.   if( pCursor ){

  217080.     Fts5FullTable *pTab = (Fts5FullTable*)(pCursor->pVtab);

  217081.     Fts5Cursor *pCsr = (Fts5Cursor*)pCursor;

  217082.     Fts5Cursor **pp;

  217083. 

  217084.     fts5FreeCursorComponents(pCsr);

  217085.     /* Remove the cursor from the Fts5Global.pCsr list */

  217086.     for(pp=&pTab->pGlobal->pCsr; (*pp)!=pCsr; pp=&(*pp)->pNext);

  217087.     *pp = pCsr->pNext;

  217088. 

  217089.     sqlite3_free(pCsr);

  217090.   }

  217091.   return SQLITE_OK;

  217092. }

  217093. 

  217094. static int fts5SorterNext(Fts5Cursor *pCsr){

  217095.   Fts5Sorter *pSorter = pCsr->pSorter;

  217096.   int rc;

  217097. 

  217098.   rc = sqlite3_step(pSorter->pStmt);

  217099.   if( rc==SQLITE_DONE ){

  217100.     rc = SQLITE_OK;

  217101.     CsrFlagSet(pCsr, FTS5CSR_EOF);

  217102.   }else if( rc==SQLITE_ROW ){

  217103.     const u8 *a;

  217104.     const u8 *aBlob;

  217105.     int nBlob;

  217106.     int i;

  217107.     int iOff = 0;

  217108.     rc = SQLITE_OK;

  217109. 

  217110.     pSorter->iRowid = sqlite3_column_int64(pSorter->pStmt, 0);

  217111.     nBlob = sqlite3_column_bytes(pSorter->pStmt, 1);

  217112.     aBlob = a = sqlite3_column_blob(pSorter->pStmt, 1);

  217113. 

  217114.     /* nBlob==0 in detail=none mode. */

  217115.     if( nBlob>0 ){

  217116.       for(i=0; i<(pSorter->nIdx-1); i++){

  217117.         int iVal;

  217118.         a += fts5GetVarint32(a, iVal);

  217119.         iOff += iVal;

  217120.         pSorter->aIdx[i] = iOff;

  217121.       }

  217122.       pSorter->aIdx[i] = &aBlob[nBlob] - a;

  217123.       pSorter->aPoslist = a;

  217124.     }

  217125. 

  217126.     fts5CsrNewrow(pCsr);

  217127.   }

  217128. 

  217129.   return rc;

  217130. }

  217131. 

  217132. 

  217133. /*

  217134. ** Set the FTS5CSR_REQUIRE_RESEEK flag on all FTS5_PLAN_MATCH cursors 

  217135. ** open on table pTab.

  217136. */

  217137. static void fts5TripCursors(Fts5FullTable *pTab){

  217138.   Fts5Cursor *pCsr;

  217139.   for(pCsr=pTab->pGlobal->pCsr; pCsr; pCsr=pCsr->pNext){

  217140.     if( pCsr->ePlan==FTS5_PLAN_MATCH

  217141.      && pCsr->base.pVtab==(sqlite3_vtab*)pTab 

  217142.     ){

  217143.       CsrFlagSet(pCsr, FTS5CSR_REQUIRE_RESEEK);

  217144.     }

  217145.   }

  217146. }

  217147. 

  217148. /*

  217149. ** If the REQUIRE_RESEEK flag is set on the cursor passed as the first

  217150. ** argument, close and reopen all Fts5IndexIter iterators that the cursor 

  217151. ** is using. Then attempt to move the cursor to a rowid equal to or laster

  217152. ** (in the cursors sort order - ASC or DESC) than the current rowid. 

  217153. **

  217154. ** If the new rowid is not equal to the old, set output parameter *pbSkip

  217155. ** to 1 before returning. Otherwise, leave it unchanged.

  217156. **

  217157. ** Return SQLITE_OK if successful or if no reseek was required, or an 

  217158. ** error code if an error occurred.

  217159. */

  217160. static int fts5CursorReseek(Fts5Cursor *pCsr, int *pbSkip){

  217161.   int rc = SQLITE_OK;

  217162.   assert( *pbSkip==0 );

  217163.   if( CsrFlagTest(pCsr, FTS5CSR_REQUIRE_RESEEK) ){

  217164.     Fts5FullTable *pTab = (Fts5FullTable*)(pCsr->base.pVtab);

  217165.     int bDesc = pCsr->bDesc;

  217166.     i64 iRowid = sqlite3Fts5ExprRowid(pCsr->pExpr);

  217167. 

  217168.     rc = sqlite3Fts5ExprFirst(pCsr->pExpr, pTab->p.pIndex, iRowid, bDesc);

  217169.     if( rc==SQLITE_OK &&  iRowid!=sqlite3Fts5ExprRowid(pCsr->pExpr) ){

  217170.       *pbSkip = 1;

  217171.     }

  217172. 

  217173.     CsrFlagClear(pCsr, FTS5CSR_REQUIRE_RESEEK);

  217174.     fts5CsrNewrow(pCsr);

  217175.     if( sqlite3Fts5ExprEof(pCsr->pExpr) ){

  217176.       CsrFlagSet(pCsr, FTS5CSR_EOF);

  217177.       *pbSkip = 1;

  217178.     }

  217179.   }

  217180.   return rc;

  217181. }

  217182. 

  217183. 

  217184. /*

  217185. ** Advance the cursor to the next row in the table that matches the 

  217186. ** search criteria.

  217187. **

  217188. ** Return SQLITE_OK if nothing goes wrong.  SQLITE_OK is returned

  217189. ** even if we reach end-of-file.  The fts5EofMethod() will be called

  217190. ** subsequently to determine whether or not an EOF was hit.

  217191. */

  217192. static int fts5NextMethod(sqlite3_vtab_cursor *pCursor){

  217193.   Fts5Cursor *pCsr = (Fts5Cursor*)pCursor;

  217194.   int rc;

  217195. 

  217196.   assert( (pCsr->ePlan<3)==

  217197.           (pCsr->ePlan==FTS5_PLAN_MATCH || pCsr->ePlan==FTS5_PLAN_SOURCE) 

  217198.   );

  217199.   assert( !CsrFlagTest(pCsr, FTS5CSR_EOF) );

  217200. 

  217201.   if( pCsr->ePlan<3 ){

  217202.     int bSkip = 0;

  217203.     if( (rc = fts5CursorReseek(pCsr, &bSkip)) || bSkip ) return rc;

  217204.     rc = sqlite3Fts5ExprNext(pCsr->pExpr, pCsr->iLastRowid);

  217205.     CsrFlagSet(pCsr, sqlite3Fts5ExprEof(pCsr->pExpr));

  217206.     fts5CsrNewrow(pCsr);

  217207.   }else{

  217208.     switch( pCsr->ePlan ){

  217209.       case FTS5_PLAN_SPECIAL: {

  217210.         CsrFlagSet(pCsr, FTS5CSR_EOF);

  217211.         rc = SQLITE_OK;

  217212.         break;

  217213.       }

  217214.   

  217215.       case FTS5_PLAN_SORTED_MATCH: {

  217216.         rc = fts5SorterNext(pCsr);

  217217.         break;

  217218.       }

  217219.   

  217220.       default:

  217221.         rc = sqlite3_step(pCsr->pStmt);

  217222.         if( rc!=SQLITE_ROW ){

  217223.           CsrFlagSet(pCsr, FTS5CSR_EOF);

  217224.           rc = sqlite3_reset(pCsr->pStmt);

  217225.         }else{

  217226.           rc = SQLITE_OK;

  217227.         }

  217228.         break;

  217229.     }

  217230.   }

  217231.   

  217232.   return rc;

  217233. }

  217234. 

  217235. 

  217236. static int fts5PrepareStatement(

  217237.   sqlite3_stmt **ppStmt,

  217238.   Fts5Config *pConfig, 

  217239.   const char *zFmt,

  217240.   ...

  217241. ){

  217242.   sqlite3_stmt *pRet = 0;

  217243.   int rc;

  217244.   char *zSql;

  217245.   va_list ap;

  217246. 

  217247.   va_start(ap, zFmt);

  217248.   zSql = sqlite3_vmprintf(zFmt, ap);

  217249.   if( zSql==0 ){

  217250.     rc = SQLITE_NOMEM; 

  217251.   }else{

  217252.     rc = sqlite3_prepare_v3(pConfig->db, zSql, -1, 

  217253.                             SQLITE_PREPARE_PERSISTENT, &pRet, 0);

  217254.     if( rc!=SQLITE_OK ){

  217255.       *pConfig->pzErrmsg = sqlite3_mprintf("%s", sqlite3_errmsg(pConfig->db));

  217256.     }

  217257.     sqlite3_free(zSql);

  217258.   }

  217259. 

  217260.   va_end(ap);

  217261.   *ppStmt = pRet;

  217262.   return rc;

  217263. } 

  217264. 

  217265. static int fts5CursorFirstSorted(

  217266.   Fts5FullTable *pTab, 

  217267.   Fts5Cursor *pCsr, 

  217268.   int bDesc

  217269. ){

  217270.   Fts5Config *pConfig = pTab->p.pConfig;

  217271.   Fts5Sorter *pSorter;

  217272.   int nPhrase;

  217273.   sqlite3_int64 nByte;

  217274.   int rc;

  217275.   const char *zRank = pCsr->zRank;

  217276.   const char *zRankArgs = pCsr->zRankArgs;

  217277.   

  217278.   nPhrase = sqlite3Fts5ExprPhraseCount(pCsr->pExpr);

  217279.   nByte = sizeof(Fts5Sorter) + sizeof(int) * (nPhrase-1);

  217280.   pSorter = (Fts5Sorter*)sqlite3_malloc64(nByte);

  217281.   if( pSorter==0 ) return SQLITE_NOMEM;

  217282.   memset(pSorter, 0, (size_t)nByte);

  217283.   pSorter->nIdx = nPhrase;

  217284. 

  217285.   /* TODO: It would be better to have some system for reusing statement

  217286.   ** handles here, rather than preparing a new one for each query. But that

  217287.   ** is not possible as SQLite reference counts the virtual table objects.

  217288.   ** And since the statement required here reads from this very virtual 

  217289.   ** table, saving it creates a circular reference.

  217290.   **

  217291.   ** If SQLite a built-in statement cache, this wouldn't be a problem. */

  217292.   rc = fts5PrepareStatement(&pSorter->pStmt, pConfig,

  217293.       "SELECT rowid, rank FROM %Q.%Q ORDER BY %s(%s%s%s) %s",

  217294.       pConfig->zDb, pConfig->zName, zRank, pConfig->zName,

  217295.       (zRankArgs ? ", " : ""),

  217296.       (zRankArgs ? zRankArgs : ""),

  217297.       bDesc ? "DESC" : "ASC"

  217298.   );

  217299. 

  217300.   pCsr->pSorter = pSorter;

  217301.   if( rc==SQLITE_OK ){

  217302.     assert( pTab->pSortCsr==0 );

  217303.     pTab->pSortCsr = pCsr;

  217304.     rc = fts5SorterNext(pCsr);

  217305.     pTab->pSortCsr = 0;

  217306.   }

  217307. 

  217308.   if( rc!=SQLITE_OK ){

  217309.     sqlite3_finalize(pSorter->pStmt);

  217310.     sqlite3_free(pSorter);

  217311.     pCsr->pSorter = 0;

  217312.   }

  217313. 

  217314.   return rc;

  217315. }

  217316. 

  217317. static int fts5CursorFirst(Fts5FullTable *pTab, Fts5Cursor *pCsr, int bDesc){

  217318.   int rc;

  217319.   Fts5Expr *pExpr = pCsr->pExpr;

  217320.   rc = sqlite3Fts5ExprFirst(pExpr, pTab->p.pIndex, pCsr->iFirstRowid, bDesc);

  217321.   if( sqlite3Fts5ExprEof(pExpr) ){

  217322.     CsrFlagSet(pCsr, FTS5CSR_EOF);

  217323.   }

  217324.   fts5CsrNewrow(pCsr);

  217325.   return rc;

  217326. }

  217327. 

  217328. /*

  217329. ** Process a "special" query. A special query is identified as one with a

  217330. ** MATCH expression that begins with a '*' character. The remainder of

  217331. ** the text passed to the MATCH operator are used as  the special query

  217332. ** parameters.

  217333. */

  217334. static int fts5SpecialMatch(

  217335.   Fts5FullTable *pTab, 

  217336.   Fts5Cursor *pCsr, 

  217337.   const char *zQuery

  217338. ){

  217339.   int rc = SQLITE_OK;             /* Return code */

  217340.   const char *z = zQuery;         /* Special query text */

  217341.   int n;                          /* Number of bytes in text at z */

  217342. 

  217343.   while( z[0]==' ' ) z++;

  217344.   for(n=0; z[n] && z[n]!=' '; n++);

  217345. 

  217346.   assert( pTab->p.base.zErrMsg==0 );

  217347.   pCsr->ePlan = FTS5_PLAN_SPECIAL;

  217348. 

  217349.   if( 0==sqlite3_strnicmp("reads", z, n) ){

  217350.     pCsr->iSpecial = sqlite3Fts5IndexReads(pTab->p.pIndex);

  217351.   }

  217352.   else if( 0==sqlite3_strnicmp("id", z, n) ){

  217353.     pCsr->iSpecial = pCsr->iCsrId;

  217354.   }

  217355.   else{

  217356.     /* An unrecognized directive. Return an error message. */

  217357.     pTab->p.base.zErrMsg = sqlite3_mprintf("unknown special query: %.*s", n, z);

  217358.     rc = SQLITE_ERROR;

  217359.   }

  217360. 

  217361.   return rc;

  217362. }

  217363. 

  217364. /*

  217365. ** Search for an auxiliary function named zName that can be used with table

  217366. ** pTab. If one is found, return a pointer to the corresponding Fts5Auxiliary

  217367. ** structure. Otherwise, if no such function exists, return NULL.

  217368. */

  217369. static Fts5Auxiliary *fts5FindAuxiliary(Fts5FullTable *pTab, const char *zName){

  217370.   Fts5Auxiliary *pAux;

  217371. 

  217372.   for(pAux=pTab->pGlobal->pAux; pAux; pAux=pAux->pNext){

  217373.     if( sqlite3_stricmp(zName, pAux->zFunc)==0 ) return pAux;

  217374.   }

  217375. 

  217376.   /* No function of the specified name was found. Return 0. */

  217377.   return 0;

  217378. }

  217379. 

  217380. 

  217381. static int fts5FindRankFunction(Fts5Cursor *pCsr){

  217382.   Fts5FullTable *pTab = (Fts5FullTable*)(pCsr->base.pVtab);

  217383.   Fts5Config *pConfig = pTab->p.pConfig;

  217384.   int rc = SQLITE_OK;

  217385.   Fts5Auxiliary *pAux = 0;

  217386.   const char *zRank = pCsr->zRank;

  217387.   const char *zRankArgs = pCsr->zRankArgs;

  217388. 

  217389.   if( zRankArgs ){

  217390.     char *zSql = sqlite3Fts5Mprintf(&rc, "SELECT %s", zRankArgs);

  217391.     if( zSql ){

  217392.       sqlite3_stmt *pStmt = 0;

  217393.       rc = sqlite3_prepare_v3(pConfig->db, zSql, -1,

  217394.                               SQLITE_PREPARE_PERSISTENT, &pStmt, 0);

  217395.       sqlite3_free(zSql);

  217396.       assert( rc==SQLITE_OK || pCsr->pRankArgStmt==0 );

  217397.       if( rc==SQLITE_OK ){

  217398.         if( SQLITE_ROW==sqlite3_step(pStmt) ){

  217399.           sqlite3_int64 nByte;

  217400.           pCsr->nRankArg = sqlite3_column_count(pStmt);

  217401.           nByte = sizeof(sqlite3_value*)*pCsr->nRankArg;

  217402.           pCsr->apRankArg = (sqlite3_value**)sqlite3Fts5MallocZero(&rc, nByte);

  217403.           if( rc==SQLITE_OK ){

  217404.             int i;

  217405.             for(i=0; i<pCsr->nRankArg; i++){

  217406.               pCsr->apRankArg[i] = sqlite3_column_value(pStmt, i);

  217407.             }

  217408.           }

  217409.           pCsr->pRankArgStmt = pStmt;

  217410.         }else{

  217411.           rc = sqlite3_finalize(pStmt);

  217412.           assert( rc!=SQLITE_OK );

  217413.         }

  217414.       }

  217415.     }

  217416.   }

  217417. 

  217418.   if( rc==SQLITE_OK ){

  217419.     pAux = fts5FindAuxiliary(pTab, zRank);

  217420.     if( pAux==0 ){

  217421.       assert( pTab->p.base.zErrMsg==0 );

  217422.       pTab->p.base.zErrMsg = sqlite3_mprintf("no such function: %s", zRank);

  217423.       rc = SQLITE_ERROR;

  217424.     }

  217425.   }

  217426. 

  217427.   pCsr->pRank = pAux;

  217428.   return rc;

  217429. }

  217430. 

  217431. 

  217432. static int fts5CursorParseRank(

  217433.   Fts5Config *pConfig,

  217434.   Fts5Cursor *pCsr, 

  217435.   sqlite3_value *pRank

  217436. ){

  217437.   int rc = SQLITE_OK;

  217438.   if( pRank ){

  217439.     const char *z = (const char*)sqlite3_value_text(pRank);

  217440.     char *zRank = 0;

  217441.     char *zRankArgs = 0;

  217442. 

  217443.     if( z==0 ){

  217444.       if( sqlite3_value_type(pRank)==SQLITE_NULL ) rc = SQLITE_ERROR;

  217445.     }else{

  217446.       rc = sqlite3Fts5ConfigParseRank(z, &zRank, &zRankArgs);

  217447.     }

  217448.     if( rc==SQLITE_OK ){

  217449.       pCsr->zRank = zRank;

  217450.       pCsr->zRankArgs = zRankArgs;

  217451.       CsrFlagSet(pCsr, FTS5CSR_FREE_ZRANK);

  217452.     }else if( rc==SQLITE_ERROR ){

  217453.       pCsr->base.pVtab->zErrMsg = sqlite3_mprintf(

  217454.           "parse error in rank function: %s", z

  217455.       );

  217456.     }

  217457.   }else{

  217458.     if( pConfig->zRank ){

  217459.       pCsr->zRank = (char*)pConfig->zRank;

  217460.       pCsr->zRankArgs = (char*)pConfig->zRankArgs;

  217461.     }else{

  217462.       pCsr->zRank = (char*)FTS5_DEFAULT_RANK;

  217463.       pCsr->zRankArgs = 0;

  217464.     }

  217465.   }

  217466.   return rc;

  217467. }

  217468. 

  217469. static i64 fts5GetRowidLimit(sqlite3_value *pVal, i64 iDefault){

  217470.   if( pVal ){

  217471.     int eType = sqlite3_value_numeric_type(pVal);

  217472.     if( eType==SQLITE_INTEGER ){

  217473.       return sqlite3_value_int64(pVal);

  217474.     }

  217475.   }

  217476.   return iDefault;

  217477. }

  217478. 

  217479. /*

  217480. ** This is the xFilter interface for the virtual table.  See

  217481. ** the virtual table xFilter method documentation for additional

  217482. ** information.

  217483. ** 

  217484. ** There are three possible query strategies:

  217485. **

  217486. **   1. Full-text search using a MATCH operator.

  217487. **   2. A by-rowid lookup.

  217488. **   3. A full-table scan.

  217489. */

  217490. static int fts5FilterMethod(

  217491.   sqlite3_vtab_cursor *pCursor,   /* The cursor used for this query */

  217492.   int idxNum,                     /* Strategy index */

  217493.   const char *zUnused,            /* Unused */

  217494.   int nVal,                       /* Number of elements in apVal */

  217495.   sqlite3_value **apVal           /* Arguments for the indexing scheme */

  217496. ){

  217497.   Fts5FullTable *pTab = (Fts5FullTable*)(pCursor->pVtab);

  217498.   Fts5Config *pConfig = pTab->p.pConfig;

  217499.   Fts5Cursor *pCsr = (Fts5Cursor*)pCursor;

  217500.   int rc = SQLITE_OK;             /* Error code */

  217501.   int iVal = 0;                   /* Counter for apVal[] */

  217502.   int bDesc;                      /* True if ORDER BY [rank|rowid] DESC */

  217503.   int bOrderByRank;               /* True if ORDER BY rank */

  217504.   sqlite3_value *pMatch = 0;      /* <tbl> MATCH ? expression (or NULL) */

  217505.   sqlite3_value *pRank = 0;       /* rank MATCH ? expression (or NULL) */

  217506.   sqlite3_value *pRowidEq = 0;    /* rowid = ? expression (or NULL) */

  217507.   sqlite3_value *pRowidLe = 0;    /* rowid <= ? expression (or NULL) */

  217508.   sqlite3_value *pRowidGe = 0;    /* rowid >= ? expression (or NULL) */

  217509.   int iCol;                       /* Column on LHS of MATCH operator */

  217510.   char **pzErrmsg = pConfig->pzErrmsg;

  217511. 

  217512.   UNUSED_PARAM(zUnused);

  217513.   UNUSED_PARAM(nVal);

  217514. 

  217515.   if( pCsr->ePlan ){

  217516.     fts5FreeCursorComponents(pCsr);

  217517.     memset(&pCsr->ePlan, 0, sizeof(Fts5Cursor) - ((u8*)&pCsr->ePlan-(u8*)pCsr));

  217518.   }

  217519. 

  217520.   assert( pCsr->pStmt==0 );

  217521.   assert( pCsr->pExpr==0 );

  217522.   assert( pCsr->csrflags==0 );

  217523.   assert( pCsr->pRank==0 );

  217524.   assert( pCsr->zRank==0 );

  217525.   assert( pCsr->zRankArgs==0 );

  217526. 

  217527.   assert( pzErrmsg==0 || pzErrmsg==&pTab->p.base.zErrMsg );

  217528.   pConfig->pzErrmsg = &pTab->p.base.zErrMsg;

  217529. 

  217530.   /* Decode the arguments passed through to this function.

  217531.   **

  217532.   ** Note: The following set of if(...) statements must be in the same

  217533.   ** order as the corresponding entries in the struct at the top of

  217534.   ** fts5BestIndexMethod().  */

  217535.   if( BitFlagTest(idxNum, FTS5_BI_MATCH) ) pMatch = apVal[iVal++];

  217536.   if( BitFlagTest(idxNum, FTS5_BI_RANK) ) pRank = apVal[iVal++];

  217537.   if( BitFlagTest(idxNum, FTS5_BI_ROWID_EQ) ) pRowidEq = apVal[iVal++];

  217538.   if( BitFlagTest(idxNum, FTS5_BI_ROWID_LE) ) pRowidLe = apVal[iVal++];

  217539.   if( BitFlagTest(idxNum, FTS5_BI_ROWID_GE) ) pRowidGe = apVal[iVal++];

  217540.   iCol = (idxNum>>16);

  217541.   assert( iCol>=0 && iCol<=pConfig->nCol );

  217542.   assert( iVal==nVal );

  217543.   bOrderByRank = ((idxNum & FTS5_BI_ORDER_RANK) ? 1 : 0);

  217544.   pCsr->bDesc = bDesc = ((idxNum & FTS5_BI_ORDER_DESC) ? 1 : 0);

  217545. 

  217546.   /* Set the cursor upper and lower rowid limits. Only some strategies 

  217547.   ** actually use them. This is ok, as the xBestIndex() method leaves the

  217548.   ** sqlite3_index_constraint.omit flag clear for range constraints

  217549.   ** on the rowid field.  */

  217550.   if( pRowidEq ){

  217551.     pRowidLe = pRowidGe = pRowidEq;

  217552.   }

  217553.   if( bDesc ){

  217554.     pCsr->iFirstRowid = fts5GetRowidLimit(pRowidLe, LARGEST_INT64);

  217555.     pCsr->iLastRowid = fts5GetRowidLimit(pRowidGe, SMALLEST_INT64);

  217556.   }else{

  217557.     pCsr->iLastRowid = fts5GetRowidLimit(pRowidLe, LARGEST_INT64);

  217558.     pCsr->iFirstRowid = fts5GetRowidLimit(pRowidGe, SMALLEST_INT64);

  217559.   }

  217560. 

  217561.   if( pTab->pSortCsr ){

  217562.     /* If pSortCsr is non-NULL, then this call is being made as part of 

  217563.     ** processing for a "... MATCH <expr> ORDER BY rank" query (ePlan is

  217564.     ** set to FTS5_PLAN_SORTED_MATCH). pSortCsr is the cursor that will

  217565.     ** return results to the user for this query. The current cursor 

  217566.     ** (pCursor) is used to execute the query issued by function 

  217567.     ** fts5CursorFirstSorted() above.  */

  217568.     assert( pRowidEq==0 && pRowidLe==0 && pRowidGe==0 && pRank==0 );

  217569.     assert( nVal==0 && pMatch==0 && bOrderByRank==0 && bDesc==0 );

  217570.     assert( pCsr->iLastRowid==LARGEST_INT64 );

  217571.     assert( pCsr->iFirstRowid==SMALLEST_INT64 );

  217572.     if( pTab->pSortCsr->bDesc ){

  217573.       pCsr->iLastRowid = pTab->pSortCsr->iFirstRowid;

  217574.       pCsr->iFirstRowid = pTab->pSortCsr->iLastRowid;

  217575.     }else{

  217576.       pCsr->iLastRowid = pTab->pSortCsr->iLastRowid;

  217577.       pCsr->iFirstRowid = pTab->pSortCsr->iFirstRowid;

  217578.     }

  217579.     pCsr->ePlan = FTS5_PLAN_SOURCE;

  217580.     pCsr->pExpr = pTab->pSortCsr->pExpr;

  217581.     rc = fts5CursorFirst(pTab, pCsr, bDesc);

  217582.   }else if( pMatch ){

  217583.     const char *zExpr = (const char*)sqlite3_value_text(apVal[0]);

  217584.     if( zExpr==0 ) zExpr = "";

  217585. 

  217586.     rc = fts5CursorParseRank(pConfig, pCsr, pRank);

  217587.     if( rc==SQLITE_OK ){

  217588.       if( zExpr[0]=='*' ){

  217589.         /* The user has issued a query of the form "MATCH '*...'". This

  217590.         ** indicates that the MATCH expression is not a full text query,

  217591.         ** but a request for an internal parameter.  */

  217592.         rc = fts5SpecialMatch(pTab, pCsr, &zExpr[1]);

  217593.       }else{

  217594.         char **pzErr = &pTab->p.base.zErrMsg;

  217595.         rc = sqlite3Fts5ExprNew(pConfig, iCol, zExpr, &pCsr->pExpr, pzErr);

  217596.         if( rc==SQLITE_OK ){

  217597.           if( bOrderByRank ){

  217598.             pCsr->ePlan = FTS5_PLAN_SORTED_MATCH;

  217599.             rc = fts5CursorFirstSorted(pTab, pCsr, bDesc);

  217600.           }else{

  217601.             pCsr->ePlan = FTS5_PLAN_MATCH;

  217602.             rc = fts5CursorFirst(pTab, pCsr, bDesc);

  217603.           }

  217604.         }

  217605.       }

  217606.     }

  217607.   }else if( pConfig->zContent==0 ){

  217608.     *pConfig->pzErrmsg = sqlite3_mprintf(

  217609.         "%s: table does not support scanning", pConfig->zName

  217610.     );

  217611.     rc = SQLITE_ERROR;

  217612.   }else{

  217613.     /* This is either a full-table scan (ePlan==FTS5_PLAN_SCAN) or a lookup

  217614.     ** by rowid (ePlan==FTS5_PLAN_ROWID).  */

  217615.     pCsr->ePlan = (pRowidEq ? FTS5_PLAN_ROWID : FTS5_PLAN_SCAN);

  217616.     rc = sqlite3Fts5StorageStmt(

  217617.         pTab->pStorage, fts5StmtType(pCsr), &pCsr->pStmt, &pTab->p.base.zErrMsg

  217618.     );

  217619.     if( rc==SQLITE_OK ){

  217620.       if( pCsr->ePlan==FTS5_PLAN_ROWID ){

  217621.         sqlite3_bind_value(pCsr->pStmt, 1, apVal[0]);

  217622.       }else{

  217623.         sqlite3_bind_int64(pCsr->pStmt, 1, pCsr->iFirstRowid);

  217624.         sqlite3_bind_int64(pCsr->pStmt, 2, pCsr->iLastRowid);

  217625.       }

  217626.       rc = fts5NextMethod(pCursor);

  217627.     }

  217628.   }

  217629. 

  217630.   pConfig->pzErrmsg = pzErrmsg;

  217631.   return rc;

  217632. }

  217633. 

  217634. /* 

  217635. ** This is the xEof method of the virtual table. SQLite calls this 

  217636. ** routine to find out if it has reached the end of a result set.

  217637. */

  217638. static int fts5EofMethod(sqlite3_vtab_cursor *pCursor){

  217639.   Fts5Cursor *pCsr = (Fts5Cursor*)pCursor;

  217640.   return (CsrFlagTest(pCsr, FTS5CSR_EOF) ? 1 : 0);

  217641. }

  217642. 

  217643. /*

  217644. ** Return the rowid that the cursor currently points to.

  217645. */

  217646. static i64 fts5CursorRowid(Fts5Cursor *pCsr){

  217647.   assert( pCsr->ePlan==FTS5_PLAN_MATCH 

  217648.        || pCsr->ePlan==FTS5_PLAN_SORTED_MATCH 

  217649.        || pCsr->ePlan==FTS5_PLAN_SOURCE 

  217650.   );

  217651.   if( pCsr->pSorter ){

  217652.     return pCsr->pSorter->iRowid;

  217653.   }else{

  217654.     return sqlite3Fts5ExprRowid(pCsr->pExpr);

  217655.   }

  217656. }

  217657. 

  217658. /* 

  217659. ** This is the xRowid method. The SQLite core calls this routine to

  217660. ** retrieve the rowid for the current row of the result set. fts5

  217661. ** exposes %_content.rowid as the rowid for the virtual table. The

  217662. ** rowid should be written to *pRowid.

  217663. */

  217664. static int fts5RowidMethod(sqlite3_vtab_cursor *pCursor, sqlite_int64 *pRowid){

  217665.   Fts5Cursor *pCsr = (Fts5Cursor*)pCursor;

  217666.   int ePlan = pCsr->ePlan;

  217667.   

  217668.   assert( CsrFlagTest(pCsr, FTS5CSR_EOF)==0 );

  217669.   switch( ePlan ){

  217670.     case FTS5_PLAN_SPECIAL:

  217671.       *pRowid = 0;

  217672.       break;

  217673. 

  217674.     case FTS5_PLAN_SOURCE:

  217675.     case FTS5_PLAN_MATCH:

  217676.     case FTS5_PLAN_SORTED_MATCH:

  217677.       *pRowid = fts5CursorRowid(pCsr);

  217678.       break;

  217679. 

  217680.     default:

  217681.       *pRowid = sqlite3_column_int64(pCsr->pStmt, 0);

  217682.       break;

  217683.   }

  217684. 

  217685.   return SQLITE_OK;

  217686. }

  217687. 

  217688. /*

  217689. ** If the cursor requires seeking (bSeekRequired flag is set), seek it.

  217690. ** Return SQLITE_OK if no error occurs, or an SQLite error code otherwise.

  217691. **

  217692. ** If argument bErrormsg is true and an error occurs, an error message may

  217693. ** be left in sqlite3_vtab.zErrMsg.

  217694. */

  217695. static int fts5SeekCursor(Fts5Cursor *pCsr, int bErrormsg){

  217696.   int rc = SQLITE_OK;

  217697. 

  217698.   /* If the cursor does not yet have a statement handle, obtain one now. */ 

  217699.   if( pCsr->pStmt==0 ){

  217700.     Fts5FullTable *pTab = (Fts5FullTable*)(pCsr->base.pVtab);

  217701.     int eStmt = fts5StmtType(pCsr);

  217702.     rc = sqlite3Fts5StorageStmt(

  217703.         pTab->pStorage, eStmt, &pCsr->pStmt, (bErrormsg?&pTab->p.base.zErrMsg:0)

  217704.     );

  217705.     assert( rc!=SQLITE_OK || pTab->p.base.zErrMsg==0 );

  217706.     assert( CsrFlagTest(pCsr, FTS5CSR_REQUIRE_CONTENT) );

  217707.   }

  217708. 

  217709.   if( rc==SQLITE_OK && CsrFlagTest(pCsr, FTS5CSR_REQUIRE_CONTENT) ){

  217710.     assert( pCsr->pExpr );

  217711.     sqlite3_reset(pCsr->pStmt);

  217712.     sqlite3_bind_int64(pCsr->pStmt, 1, fts5CursorRowid(pCsr));

  217713.     rc = sqlite3_step(pCsr->pStmt);

  217714.     if( rc==SQLITE_ROW ){

  217715.       rc = SQLITE_OK;

  217716.       CsrFlagClear(pCsr, FTS5CSR_REQUIRE_CONTENT);

  217717.     }else{

  217718.       rc = sqlite3_reset(pCsr->pStmt);

  217719.       if( rc==SQLITE_OK ){

  217720.         rc = FTS5_CORRUPT;

  217721.       }

  217722.     }

  217723.   }

  217724.   return rc;

  217725. }

  217726. 

  217727. static void fts5SetVtabError(Fts5FullTable *p, const char *zFormat, ...){

  217728.   va_list ap;                     /* ... printf arguments */

  217729.   va_start(ap, zFormat);

  217730.   assert( p->p.base.zErrMsg==0 );

  217731.   p->p.base.zErrMsg = sqlite3_vmprintf(zFormat, ap);

  217732.   va_end(ap);

  217733. }

  217734. 

  217735. /*

  217736. ** This function is called to handle an FTS INSERT command. In other words,

  217737. ** an INSERT statement of the form:

  217738. **

  217739. **     INSERT INTO fts(fts) VALUES($pCmd)

  217740. **     INSERT INTO fts(fts, rank) VALUES($pCmd, $pVal)

  217741. **

  217742. ** Argument pVal is the value assigned to column "fts" by the INSERT 

  217743. ** statement. This function returns SQLITE_OK if successful, or an SQLite

  217744. ** error code if an error occurs.

  217745. **

  217746. ** The commands implemented by this function are documented in the "Special

  217747. ** INSERT Directives" section of the documentation. It should be updated if

  217748. ** more commands are added to this function.

  217749. */

  217750. static int fts5SpecialInsert(

  217751.   Fts5FullTable *pTab,            /* Fts5 table object */

  217752.   const char *zCmd,               /* Text inserted into table-name column */

  217753.   sqlite3_value *pVal             /* Value inserted into rank column */

  217754. ){

  217755.   Fts5Config *pConfig = pTab->p.pConfig;

  217756.   int rc = SQLITE_OK;

  217757.   int bError = 0;

  217758. 

  217759.   if( 0==sqlite3_stricmp("delete-all", zCmd) ){

  217760.     if( pConfig->eContent==FTS5_CONTENT_NORMAL ){

  217761.       fts5SetVtabError(pTab, 

  217762.           "'delete-all' may only be used with a "

  217763.           "contentless or external content fts5 table"

  217764.       );

  217765.       rc = SQLITE_ERROR;

  217766.     }else{

  217767.       rc = sqlite3Fts5StorageDeleteAll(pTab->pStorage);

  217768.     }

  217769.   }else if( 0==sqlite3_stricmp("rebuild", zCmd) ){

  217770.     if( pConfig->eContent==FTS5_CONTENT_NONE ){

  217771.       fts5SetVtabError(pTab, 

  217772.           "'rebuild' may not be used with a contentless fts5 table"

  217773.       );

  217774.       rc = SQLITE_ERROR;

  217775.     }else{

  217776.       rc = sqlite3Fts5StorageRebuild(pTab->pStorage);

  217777.     }

  217778.   }else if( 0==sqlite3_stricmp("optimize", zCmd) ){

  217779.     rc = sqlite3Fts5StorageOptimize(pTab->pStorage);

  217780.   }else if( 0==sqlite3_stricmp("merge", zCmd) ){

  217781.     int nMerge = sqlite3_value_int(pVal);

  217782.     rc = sqlite3Fts5StorageMerge(pTab->pStorage, nMerge);

  217783.   }else if( 0==sqlite3_stricmp("integrity-check", zCmd) ){

  217784.     rc = sqlite3Fts5StorageIntegrity(pTab->pStorage);

  217785. #ifdef SQLITE_DEBUG

  217786.   }else if( 0==sqlite3_stricmp("prefix-index", zCmd) ){

  217787.     pConfig->bPrefixIndex = sqlite3_value_int(pVal);

  217788. #endif

  217789.   }else{

  217790.     rc = sqlite3Fts5IndexLoadConfig(pTab->p.pIndex);

  217791.     if( rc==SQLITE_OK ){

  217792.       rc = sqlite3Fts5ConfigSetValue(pTab->p.pConfig, zCmd, pVal, &bError);

  217793.     }

  217794.     if( rc==SQLITE_OK ){

  217795.       if( bError ){

  217796.         rc = SQLITE_ERROR;

  217797.       }else{

  217798.         rc = sqlite3Fts5StorageConfigValue(pTab->pStorage, zCmd, pVal, 0);

  217799.       }

  217800.     }

  217801.   }

  217802.   return rc;

  217803. }

  217804. 

  217805. static int fts5SpecialDelete(

  217806.   Fts5FullTable *pTab, 

  217807.   sqlite3_value **apVal

  217808. ){

  217809.   int rc = SQLITE_OK;

  217810.   int eType1 = sqlite3_value_type(apVal[1]);

  217811.   if( eType1==SQLITE_INTEGER ){

  217812.     sqlite3_int64 iDel = sqlite3_value_int64(apVal[1]);

  217813.     rc = sqlite3Fts5StorageDelete(pTab->pStorage, iDel, &apVal[2]);

  217814.   }

  217815.   return rc;

  217816. }

  217817. 

  217818. static void fts5StorageInsert(

  217819.   int *pRc, 

  217820.   Fts5FullTable *pTab, 

  217821.   sqlite3_value **apVal, 

  217822.   i64 *piRowid

  217823. ){

  217824.   int rc = *pRc;

  217825.   if( rc==SQLITE_OK ){

  217826.     rc = sqlite3Fts5StorageContentInsert(pTab->pStorage, apVal, piRowid);

  217827.   }

  217828.   if( rc==SQLITE_OK ){

  217829.     rc = sqlite3Fts5StorageIndexInsert(pTab->pStorage, apVal, *piRowid);

  217830.   }

  217831.   *pRc = rc;

  217832. }

  217833. 

  217834. /* 

  217835. ** This function is the implementation of the xUpdate callback used by 

  217836. ** FTS3 virtual tables. It is invoked by SQLite each time a row is to be

  217837. ** inserted, updated or deleted.

  217838. **

  217839. ** A delete specifies a single argument - the rowid of the row to remove.

  217840. ** 

  217841. ** Update and insert operations pass:

  217842. **

  217843. **   1. The "old" rowid, or NULL.

  217844. **   2. The "new" rowid.

  217845. **   3. Values for each of the nCol matchable columns.

  217846. **   4. Values for the two hidden columns (<tablename> and "rank").

  217847. */

  217848. static int fts5UpdateMethod(

  217849.   sqlite3_vtab *pVtab,            /* Virtual table handle */

  217850.   int nArg,                       /* Size of argument array */

  217851.   sqlite3_value **apVal,          /* Array of arguments */

  217852.   sqlite_int64 *pRowid            /* OUT: The affected (or effected) rowid */

  217853. ){

  217854.   Fts5FullTable *pTab = (Fts5FullTable*)pVtab;

  217855.   Fts5Config *pConfig = pTab->p.pConfig;

  217856.   int eType0;                     /* value_type() of apVal[0] */

  217857.   int rc = SQLITE_OK;             /* Return code */

  217858. 

  217859.   /* A transaction must be open when this is called. */

  217860.   assert( pTab->ts.eState==1 );

  217861. 

  217862.   assert( pVtab->zErrMsg==0 );

  217863.   assert( nArg==1 || nArg==(2+pConfig->nCol+2) );

  217864.   assert( sqlite3_value_type(apVal[0])==SQLITE_INTEGER 

  217865.        || sqlite3_value_type(apVal[0])==SQLITE_NULL 

  217866.   );

  217867.   assert( pTab->p.pConfig->pzErrmsg==0 );

  217868.   pTab->p.pConfig->pzErrmsg = &pTab->p.base.zErrMsg;

  217869. 

  217870.   /* Put any active cursors into REQUIRE_SEEK state. */

  217871.   fts5TripCursors(pTab);

  217872. 

  217873.   eType0 = sqlite3_value_type(apVal[0]);

  217874.   if( eType0==SQLITE_NULL 

  217875.    && sqlite3_value_type(apVal[2+pConfig->nCol])!=SQLITE_NULL 

  217876.   ){

  217877.     /* A "special" INSERT op. These are handled separately. */

  217878.     const char *z = (const char*)sqlite3_value_text(apVal[2+pConfig->nCol]);

  217879.     if( pConfig->eContent!=FTS5_CONTENT_NORMAL 

  217880.       && 0==sqlite3_stricmp("delete", z) 

  217881.     ){

  217882.       rc = fts5SpecialDelete(pTab, apVal);

  217883.     }else{

  217884.       rc = fts5SpecialInsert(pTab, z, apVal[2 + pConfig->nCol + 1]);

  217885.     }

  217886.   }else{

  217887.     /* A regular INSERT, UPDATE or DELETE statement. The trick here is that

  217888.     ** any conflict on the rowid value must be detected before any 

  217889.     ** modifications are made to the database file. There are 4 cases:

  217890.     **

  217891.     **   1) DELETE

  217892.     **   2) UPDATE (rowid not modified)

  217893.     **   3) UPDATE (rowid modified)

  217894.     **   4) INSERT

  217895.     **

  217896.     ** Cases 3 and 4 may violate the rowid constraint.

  217897.     */

  217898.     int eConflict = SQLITE_ABORT;

  217899.     if( pConfig->eContent==FTS5_CONTENT_NORMAL ){

  217900.       eConflict = sqlite3_vtab_on_conflict(pConfig->db);

  217901.     }

  217902. 

  217903.     assert( eType0==SQLITE_INTEGER || eType0==SQLITE_NULL );

  217904.     assert( nArg!=1 || eType0==SQLITE_INTEGER );

  217905. 

  217906.     /* Filter out attempts to run UPDATE or DELETE on contentless tables.

  217907.     ** This is not suported.  */

  217908.     if( eType0==SQLITE_INTEGER && fts5IsContentless(pTab) ){

  217909.       pTab->p.base.zErrMsg = sqlite3_mprintf(

  217910.           "cannot %s contentless fts5 table: %s", 

  217911.           (nArg>1 ? "UPDATE" : "DELETE from"), pConfig->zName

  217912.       );

  217913.       rc = SQLITE_ERROR;

  217914.     }

  217915. 

  217916.     /* DELETE */

  217917.     else if( nArg==1 ){

  217918.       i64 iDel = sqlite3_value_int64(apVal[0]);  /* Rowid to delete */

  217919.       rc = sqlite3Fts5StorageDelete(pTab->pStorage, iDel, 0);

  217920.     }

  217921. 

  217922.     /* INSERT or UPDATE */

  217923.     else{

  217924.       int eType1 = sqlite3_value_numeric_type(apVal[1]);

  217925. 

  217926.       if( eType1!=SQLITE_INTEGER && eType1!=SQLITE_NULL ){

  217927.         rc = SQLITE_MISMATCH;

  217928.       }

  217929. 

  217930.       else if( eType0!=SQLITE_INTEGER ){     

  217931.         /* If this is a REPLACE, first remove the current entry (if any) */

  217932.         if( eConflict==SQLITE_REPLACE && eType1==SQLITE_INTEGER ){

  217933.           i64 iNew = sqlite3_value_int64(apVal[1]);  /* Rowid to delete */

  217934.           rc = sqlite3Fts5StorageDelete(pTab->pStorage, iNew, 0);

  217935.         }

  217936.         fts5StorageInsert(&rc, pTab, apVal, pRowid);

  217937.       }

  217938. 

  217939.       /* UPDATE */

  217940.       else{

  217941.         i64 iOld = sqlite3_value_int64(apVal[0]);  /* Old rowid */

  217942.         i64 iNew = sqlite3_value_int64(apVal[1]);  /* New rowid */

  217943.         if( eType1==SQLITE_INTEGER && iOld!=iNew ){

  217944.           if( eConflict==SQLITE_REPLACE ){

  217945.             rc = sqlite3Fts5StorageDelete(pTab->pStorage, iOld, 0);

  217946.             if( rc==SQLITE_OK ){

  217947.               rc = sqlite3Fts5StorageDelete(pTab->pStorage, iNew, 0);

  217948.             }

  217949.             fts5StorageInsert(&rc, pTab, apVal, pRowid);

  217950.           }else{

  217951.             rc = sqlite3Fts5StorageContentInsert(pTab->pStorage, apVal, pRowid);

  217952.             if( rc==SQLITE_OK ){

  217953.               rc = sqlite3Fts5StorageDelete(pTab->pStorage, iOld, 0);

  217954.             }

  217955.             if( rc==SQLITE_OK ){

  217956.               rc = sqlite3Fts5StorageIndexInsert(pTab->pStorage, apVal,*pRowid);

  217957.             }

  217958.           }

  217959.         }else{

  217960.           rc = sqlite3Fts5StorageDelete(pTab->pStorage, iOld, 0);

  217961.           fts5StorageInsert(&rc, pTab, apVal, pRowid);

  217962.         }

  217963.       }

  217964.     }

  217965.   }

  217966. 

  217967.   pTab->p.pConfig->pzErrmsg = 0;

  217968.   return rc;

  217969. }

  217970. 

  217971. /*

  217972. ** Implementation of xSync() method. 

  217973. */

  217974. static int fts5SyncMethod(sqlite3_vtab *pVtab){

  217975.   int rc;

  217976.   Fts5FullTable *pTab = (Fts5FullTable*)pVtab;

  217977.   fts5CheckTransactionState(pTab, FTS5_SYNC, 0);

  217978.   pTab->p.pConfig->pzErrmsg = &pTab->p.base.zErrMsg;

  217979.   fts5TripCursors(pTab);

  217980.   rc = sqlite3Fts5StorageSync(pTab->pStorage);

  217981.   pTab->p.pConfig->pzErrmsg = 0;

  217982.   return rc;

  217983. }

  217984. 

  217985. /*

  217986. ** Implementation of xBegin() method. 

  217987. */

  217988. static int fts5BeginMethod(sqlite3_vtab *pVtab){

  217989.   fts5CheckTransactionState((Fts5FullTable*)pVtab, FTS5_BEGIN, 0);

  217990.   fts5NewTransaction((Fts5FullTable*)pVtab);

  217991.   return SQLITE_OK;

  217992. }

  217993. 

  217994. /*

  217995. ** Implementation of xCommit() method. This is a no-op. The contents of

  217996. ** the pending-terms hash-table have already been flushed into the database

  217997. ** by fts5SyncMethod().

  217998. */

  217999. static int fts5CommitMethod(sqlite3_vtab *pVtab){

  218000.   UNUSED_PARAM(pVtab);  /* Call below is a no-op for NDEBUG builds */

  218001.   fts5CheckTransactionState((Fts5FullTable*)pVtab, FTS5_COMMIT, 0);

  218002.   return SQLITE_OK;

  218003. }

  218004. 

  218005. /*

  218006. ** Implementation of xRollback(). Discard the contents of the pending-terms

  218007. ** hash-table. Any changes made to the database are reverted by SQLite.

  218008. */

  218009. static int fts5RollbackMethod(sqlite3_vtab *pVtab){

  218010.   int rc;

  218011.   Fts5FullTable *pTab = (Fts5FullTable*)pVtab;

  218012.   fts5CheckTransactionState(pTab, FTS5_ROLLBACK, 0);

  218013.   rc = sqlite3Fts5StorageRollback(pTab->pStorage);

  218014.   return rc;

  218015. }

  218016. 

  218017. static int fts5CsrPoslist(Fts5Cursor*, int, const u8**, int*);

  218018. 

  218019. static void *fts5ApiUserData(Fts5Context *pCtx){

  218020.   Fts5Cursor *pCsr = (Fts5Cursor*)pCtx;

  218021.   return pCsr->pAux->pUserData;

  218022. }

  218023. 

  218024. static int fts5ApiColumnCount(Fts5Context *pCtx){

  218025.   Fts5Cursor *pCsr = (Fts5Cursor*)pCtx;

  218026.   return ((Fts5Table*)(pCsr->base.pVtab))->pConfig->nCol;

  218027. }

  218028. 

  218029. static int fts5ApiColumnTotalSize(

  218030.   Fts5Context *pCtx, 

  218031.   int iCol, 

  218032.   sqlite3_int64 *pnToken

  218033. ){

  218034.   Fts5Cursor *pCsr = (Fts5Cursor*)pCtx;

  218035.   Fts5FullTable *pTab = (Fts5FullTable*)(pCsr->base.pVtab);

  218036.   return sqlite3Fts5StorageSize(pTab->pStorage, iCol, pnToken);

  218037. }

  218038. 

  218039. static int fts5ApiRowCount(Fts5Context *pCtx, i64 *pnRow){

  218040.   Fts5Cursor *pCsr = (Fts5Cursor*)pCtx;

  218041.   Fts5FullTable *pTab = (Fts5FullTable*)(pCsr->base.pVtab);

  218042.   return sqlite3Fts5StorageRowCount(pTab->pStorage, pnRow);

  218043. }

  218044. 

  218045. static int fts5ApiTokenize(

  218046.   Fts5Context *pCtx, 

  218047.   const char *pText, int nText, 

  218048.   void *pUserData,

  218049.   int (*xToken)(void*, int, const char*, int, int, int)

  218050. ){

  218051.   Fts5Cursor *pCsr = (Fts5Cursor*)pCtx;

  218052.   Fts5Table *pTab = (Fts5Table*)(pCsr->base.pVtab);

  218053.   return sqlite3Fts5Tokenize(

  218054.       pTab->pConfig, FTS5_TOKENIZE_AUX, pText, nText, pUserData, xToken

  218055.   );

  218056. }

  218057. 

  218058. static int fts5ApiPhraseCount(Fts5Context *pCtx){

  218059.   Fts5Cursor *pCsr = (Fts5Cursor*)pCtx;

  218060.   return sqlite3Fts5ExprPhraseCount(pCsr->pExpr);

  218061. }

  218062. 

  218063. static int fts5ApiPhraseSize(Fts5Context *pCtx, int iPhrase){

  218064.   Fts5Cursor *pCsr = (Fts5Cursor*)pCtx;

  218065.   return sqlite3Fts5ExprPhraseSize(pCsr->pExpr, iPhrase);

  218066. }

  218067. 

  218068. static int fts5ApiColumnText(

  218069.   Fts5Context *pCtx, 

  218070.   int iCol, 

  218071.   const char **pz, 

  218072.   int *pn

  218073. ){

  218074.   int rc = SQLITE_OK;

  218075.   Fts5Cursor *pCsr = (Fts5Cursor*)pCtx;

  218076.   if( fts5IsContentless((Fts5FullTable*)(pCsr->base.pVtab)) 

  218077.    || pCsr->ePlan==FTS5_PLAN_SPECIAL 

  218078.   ){

  218079.     *pz = 0;

  218080.     *pn = 0;

  218081.   }else{

  218082.     rc = fts5SeekCursor(pCsr, 0);

  218083.     if( rc==SQLITE_OK ){

  218084.       *pz = (const char*)sqlite3_column_text(pCsr->pStmt, iCol+1);

  218085.       *pn = sqlite3_column_bytes(pCsr->pStmt, iCol+1);

  218086.     }

  218087.   }

  218088.   return rc;

  218089. }

  218090. 

  218091. static int fts5CsrPoslist(

  218092.   Fts5Cursor *pCsr, 

  218093.   int iPhrase, 

  218094.   const u8 **pa,

  218095.   int *pn

  218096. ){

  218097.   Fts5Config *pConfig = ((Fts5Table*)(pCsr->base.pVtab))->pConfig;

  218098.   int rc = SQLITE_OK;

  218099.   int bLive = (pCsr->pSorter==0);

  218100. 

  218101.   if( CsrFlagTest(pCsr, FTS5CSR_REQUIRE_POSLIST) ){

  218102. 

  218103.     if( pConfig->eDetail!=FTS5_DETAIL_FULL ){

  218104.       Fts5PoslistPopulator *aPopulator;

  218105.       int i;

  218106.       aPopulator = sqlite3Fts5ExprClearPoslists(pCsr->pExpr, bLive);

  218107.       if( aPopulator==0 ) rc = SQLITE_NOMEM;

  218108.       for(i=0; i<pConfig->nCol && rc==SQLITE_OK; i++){

  218109.         int n; const char *z;

  218110.         rc = fts5ApiColumnText((Fts5Context*)pCsr, i, &z, &n);

  218111.         if( rc==SQLITE_OK ){

  218112.           rc = sqlite3Fts5ExprPopulatePoslists(

  218113.               pConfig, pCsr->pExpr, aPopulator, i, z, n

  218114.           );

  218115.         }

  218116.       }

  218117.       sqlite3_free(aPopulator);

  218118. 

  218119.       if( pCsr->pSorter ){

  218120.         sqlite3Fts5ExprCheckPoslists(pCsr->pExpr, pCsr->pSorter->iRowid);

  218121.       }

  218122.     }

  218123.     CsrFlagClear(pCsr, FTS5CSR_REQUIRE_POSLIST);

  218124.   }

  218125. 

  218126.   if( pCsr->pSorter && pConfig->eDetail==FTS5_DETAIL_FULL ){

  218127.     Fts5Sorter *pSorter = pCsr->pSorter;

  218128.     int i1 = (iPhrase==0 ? 0 : pSorter->aIdx[iPhrase-1]);

  218129.     *pn = pSorter->aIdx[iPhrase] - i1;

  218130.     *pa = &pSorter->aPoslist[i1];

  218131.   }else{

  218132.     *pn = sqlite3Fts5ExprPoslist(pCsr->pExpr, iPhrase, pa);

  218133.   }

  218134. 

  218135.   return rc;

  218136. }

  218137. 

  218138. /*

  218139. ** Ensure that the Fts5Cursor.nInstCount and aInst[] variables are populated

  218140. ** correctly for the current view. Return SQLITE_OK if successful, or an

  218141. ** SQLite error code otherwise.

  218142. */

  218143. static int fts5CacheInstArray(Fts5Cursor *pCsr){

  218144.   int rc = SQLITE_OK;

  218145.   Fts5PoslistReader *aIter;       /* One iterator for each phrase */

  218146.   int nIter;                      /* Number of iterators/phrases */

  218147.   int nCol = ((Fts5Table*)pCsr->base.pVtab)->pConfig->nCol;

  218148.   

  218149.   nIter = sqlite3Fts5ExprPhraseCount(pCsr->pExpr);

  218150.   if( pCsr->aInstIter==0 ){

  218151.     sqlite3_int64 nByte = sizeof(Fts5PoslistReader) * nIter;

  218152.     pCsr->aInstIter = (Fts5PoslistReader*)sqlite3Fts5MallocZero(&rc, nByte);

  218153.   }

  218154.   aIter = pCsr->aInstIter;

  218155. 

  218156.   if( aIter ){

  218157.     int nInst = 0;                /* Number instances seen so far */

  218158.     int i;

  218159. 

  218160.     /* Initialize all iterators */

  218161.     for(i=0; i<nIter && rc==SQLITE_OK; i++){

  218162.       const u8 *a;

  218163.       int n; 

  218164.       rc = fts5CsrPoslist(pCsr, i, &a, &n);

  218165.       if( rc==SQLITE_OK ){

  218166.         sqlite3Fts5PoslistReaderInit(a, n, &aIter[i]);

  218167.       }

  218168.     }

  218169. 

  218170.     if( rc==SQLITE_OK ){

  218171.       while( 1 ){

  218172.         int *aInst;

  218173.         int iBest = -1;

  218174.         for(i=0; i<nIter; i++){

  218175.           if( (aIter[i].bEof==0) 

  218176.               && (iBest<0 || aIter[i].iPos<aIter[iBest].iPos) 

  218177.             ){

  218178.             iBest = i;

  218179.           }

  218180.         }

  218181.         if( iBest<0 ) break;

  218182. 

  218183.         nInst++;

  218184.         if( nInst>=pCsr->nInstAlloc ){

  218185.           pCsr->nInstAlloc = pCsr->nInstAlloc ? pCsr->nInstAlloc*2 : 32;

  218186.           aInst = (int*)sqlite3_realloc64(

  218187.               pCsr->aInst, pCsr->nInstAlloc*sizeof(int)*3

  218188.               );

  218189.           if( aInst ){

  218190.             pCsr->aInst = aInst;

  218191.           }else{

  218192.             rc = SQLITE_NOMEM;

  218193.             break;

  218194.           }

  218195.         }

  218196. 

  218197.         aInst = &pCsr->aInst[3 * (nInst-1)];

  218198.         aInst[0] = iBest;

  218199.         aInst[1] = FTS5_POS2COLUMN(aIter[iBest].iPos);

  218200.         aInst[2] = FTS5_POS2OFFSET(aIter[iBest].iPos);

  218201.         if( aInst[1]<0 || aInst[1]>=nCol ){

  218202.           rc = FTS5_CORRUPT;

  218203.           break;

  218204.         }

  218205.         sqlite3Fts5PoslistReaderNext(&aIter[iBest]);

  218206.       }

  218207.     }

  218208. 

  218209.     pCsr->nInstCount = nInst;

  218210.     CsrFlagClear(pCsr, FTS5CSR_REQUIRE_INST);

  218211.   }

  218212.   return rc;

  218213. }

  218214. 

  218215. static int fts5ApiInstCount(Fts5Context *pCtx, int *pnInst){

  218216.   Fts5Cursor *pCsr = (Fts5Cursor*)pCtx;

  218217.   int rc = SQLITE_OK;

  218218.   if( CsrFlagTest(pCsr, FTS5CSR_REQUIRE_INST)==0 

  218219.    || SQLITE_OK==(rc = fts5CacheInstArray(pCsr)) ){

  218220.     *pnInst = pCsr->nInstCount;

  218221.   }

  218222.   return rc;

  218223. }

  218224. 

  218225. static int fts5ApiInst(

  218226.   Fts5Context *pCtx, 

  218227.   int iIdx, 

  218228.   int *piPhrase, 

  218229.   int *piCol, 

  218230.   int *piOff

  218231. ){

  218232.   Fts5Cursor *pCsr = (Fts5Cursor*)pCtx;

  218233.   int rc = SQLITE_OK;

  218234.   if( CsrFlagTest(pCsr, FTS5CSR_REQUIRE_INST)==0 

  218235.    || SQLITE_OK==(rc = fts5CacheInstArray(pCsr)) 

  218236.   ){

  218237.     if( iIdx<0 || iIdx>=pCsr->nInstCount ){

  218238.       rc = SQLITE_RANGE;

  218239. #if 0

  218240.     }else if( fts5IsOffsetless((Fts5Table*)pCsr->base.pVtab) ){

  218241.       *piPhrase = pCsr->aInst[iIdx*3];

  218242.       *piCol = pCsr->aInst[iIdx*3 + 2];

  218243.       *piOff = -1;

  218244. #endif

  218245.     }else{

  218246.       *piPhrase = pCsr->aInst[iIdx*3];

  218247.       *piCol = pCsr->aInst[iIdx*3 + 1];

  218248.       *piOff = pCsr->aInst[iIdx*3 + 2];

  218249.     }

  218250.   }

  218251.   return rc;

  218252. }

  218253. 

  218254. static sqlite3_int64 fts5ApiRowid(Fts5Context *pCtx){

  218255.   return fts5CursorRowid((Fts5Cursor*)pCtx);

  218256. }

  218257. 

  218258. static int fts5ColumnSizeCb(

  218259.   void *pContext,                 /* Pointer to int */

  218260.   int tflags,

  218261.   const char *pUnused,            /* Buffer containing token */

  218262.   int nUnused,                    /* Size of token in bytes */

  218263.   int iUnused1,                   /* Start offset of token */

  218264.   int iUnused2                    /* End offset of token */

  218265. ){

  218266.   int *pCnt = (int*)pContext;

  218267.   UNUSED_PARAM2(pUnused, nUnused);

  218268.   UNUSED_PARAM2(iUnused1, iUnused2);

  218269.   if( (tflags & FTS5_TOKEN_COLOCATED)==0 ){

  218270.     (*pCnt)++;

  218271.   }

  218272.   return SQLITE_OK;

  218273. }

  218274. 

  218275. static int fts5ApiColumnSize(Fts5Context *pCtx, int iCol, int *pnToken){

  218276.   Fts5Cursor *pCsr = (Fts5Cursor*)pCtx;

  218277.   Fts5FullTable *pTab = (Fts5FullTable*)(pCsr->base.pVtab);

  218278.   Fts5Config *pConfig = pTab->p.pConfig;

  218279.   int rc = SQLITE_OK;

  218280. 

  218281.   if( CsrFlagTest(pCsr, FTS5CSR_REQUIRE_DOCSIZE) ){

  218282.     if( pConfig->bColumnsize ){

  218283.       i64 iRowid = fts5CursorRowid(pCsr);

  218284.       rc = sqlite3Fts5StorageDocsize(pTab->pStorage, iRowid, pCsr->aColumnSize);

  218285.     }else if( pConfig->zContent==0 ){

  218286.       int i;

  218287.       for(i=0; i<pConfig->nCol; i++){

  218288.         if( pConfig->abUnindexed[i]==0 ){

  218289.           pCsr->aColumnSize[i] = -1;

  218290.         }

  218291.       }

  218292.     }else{

  218293.       int i;

  218294.       for(i=0; rc==SQLITE_OK && i<pConfig->nCol; i++){

  218295.         if( pConfig->abUnindexed[i]==0 ){

  218296.           const char *z; int n;

  218297.           void *p = (void*)(&pCsr->aColumnSize[i]);

  218298.           pCsr->aColumnSize[i] = 0;

  218299.           rc = fts5ApiColumnText(pCtx, i, &z, &n);

  218300.           if( rc==SQLITE_OK ){

  218301.             rc = sqlite3Fts5Tokenize(

  218302.                 pConfig, FTS5_TOKENIZE_AUX, z, n, p, fts5ColumnSizeCb

  218303.             );

  218304.           }

  218305.         }

  218306.       }

  218307.     }

  218308.     CsrFlagClear(pCsr, FTS5CSR_REQUIRE_DOCSIZE);

  218309.   }

  218310.   if( iCol<0 ){

  218311.     int i;

  218312.     *pnToken = 0;

  218313.     for(i=0; i<pConfig->nCol; i++){

  218314.       *pnToken += pCsr->aColumnSize[i];

  218315.     }

  218316.   }else if( iCol<pConfig->nCol ){

  218317.     *pnToken = pCsr->aColumnSize[iCol];

  218318.   }else{

  218319.     *pnToken = 0;

  218320.     rc = SQLITE_RANGE;

  218321.   }

  218322.   return rc;

  218323. }

  218324. 

  218325. /*

  218326. ** Implementation of the xSetAuxdata() method.

  218327. */

  218328. static int fts5ApiSetAuxdata(

  218329.   Fts5Context *pCtx,              /* Fts5 context */

  218330.   void *pPtr,                     /* Pointer to save as auxdata */

  218331.   void(*xDelete)(void*)           /* Destructor for pPtr (or NULL) */

  218332. ){

  218333.   Fts5Cursor *pCsr = (Fts5Cursor*)pCtx;

  218334.   Fts5Auxdata *pData;

  218335. 

  218336.   /* Search through the cursors list of Fts5Auxdata objects for one that

  218337.   ** corresponds to the currently executing auxiliary function.  */

  218338.   for(pData=pCsr->pAuxdata; pData; pData=pData->pNext){

  218339.     if( pData->pAux==pCsr->pAux ) break;

  218340.   }

  218341. 

  218342.   if( pData ){

  218343.     if( pData->xDelete ){

  218344.       pData->xDelete(pData->pPtr);

  218345.     }

  218346.   }else{

  218347.     int rc = SQLITE_OK;

  218348.     pData = (Fts5Auxdata*)sqlite3Fts5MallocZero(&rc, sizeof(Fts5Auxdata));

  218349.     if( pData==0 ){

  218350.       if( xDelete ) xDelete(pPtr);

  218351.       return rc;

  218352.     }

  218353.     pData->pAux = pCsr->pAux;

  218354.     pData->pNext = pCsr->pAuxdata;

  218355.     pCsr->pAuxdata = pData;

  218356.   }

  218357. 

  218358.   pData->xDelete = xDelete;

  218359.   pData->pPtr = pPtr;

  218360.   return SQLITE_OK;

  218361. }

  218362. 

  218363. static void *fts5ApiGetAuxdata(Fts5Context *pCtx, int bClear){

  218364.   Fts5Cursor *pCsr = (Fts5Cursor*)pCtx;

  218365.   Fts5Auxdata *pData;

  218366.   void *pRet = 0;

  218367. 

  218368.   for(pData=pCsr->pAuxdata; pData; pData=pData->pNext){

  218369.     if( pData->pAux==pCsr->pAux ) break;

  218370.   }

  218371. 

  218372.   if( pData ){

  218373.     pRet = pData->pPtr;

  218374.     if( bClear ){

  218375.       pData->pPtr = 0;

  218376.       pData->xDelete = 0;

  218377.     }

  218378.   }

  218379. 

  218380.   return pRet;

  218381. }

  218382. 

  218383. static void fts5ApiPhraseNext(

  218384.   Fts5Context *pUnused, 

  218385.   Fts5PhraseIter *pIter, 

  218386.   int *piCol, int *piOff

  218387. ){

  218388.   UNUSED_PARAM(pUnused);

  218389.   if( pIter->a>=pIter->b ){

  218390.     *piCol = -1;

  218391.     *piOff = -1;

  218392.   }else{

  218393.     int iVal;

  218394.     pIter->a += fts5GetVarint32(pIter->a, iVal);

  218395.     if( iVal==1 ){

  218396.       pIter->a += fts5GetVarint32(pIter->a, iVal);

  218397.       *piCol = iVal;

  218398.       *piOff = 0;

  218399.       pIter->a += fts5GetVarint32(pIter->a, iVal);

  218400.     }

  218401.     *piOff += (iVal-2);

  218402.   }

  218403. }

  218404. 

  218405. static int fts5ApiPhraseFirst(

  218406.   Fts5Context *pCtx, 

  218407.   int iPhrase, 

  218408.   Fts5PhraseIter *pIter, 

  218409.   int *piCol, int *piOff

  218410. ){

  218411.   Fts5Cursor *pCsr = (Fts5Cursor*)pCtx;

  218412.   int n;

  218413.   int rc = fts5CsrPoslist(pCsr, iPhrase, &pIter->a, &n);

  218414.   if( rc==SQLITE_OK ){

  218415.     pIter->b = &pIter->a[n];

  218416.     *piCol = 0;

  218417.     *piOff = 0;

  218418.     fts5ApiPhraseNext(pCtx, pIter, piCol, piOff);

  218419.   }

  218420.   return rc;

  218421. }

  218422. 

  218423. static void fts5ApiPhraseNextColumn(

  218424.   Fts5Context *pCtx, 

  218425.   Fts5PhraseIter *pIter, 

  218426.   int *piCol

  218427. ){

  218428.   Fts5Cursor *pCsr = (Fts5Cursor*)pCtx;

  218429.   Fts5Config *pConfig = ((Fts5Table*)(pCsr->base.pVtab))->pConfig;

  218430. 

  218431.   if( pConfig->eDetail==FTS5_DETAIL_COLUMNS ){

  218432.     if( pIter->a>=pIter->b ){

  218433.       *piCol = -1;

  218434.     }else{

  218435.       int iIncr;

  218436.       pIter->a += fts5GetVarint32(&pIter->a[0], iIncr);

  218437.       *piCol += (iIncr-2);

  218438.     }

  218439.   }else{

  218440.     while( 1 ){

  218441.       int dummy;

  218442.       if( pIter->a>=pIter->b ){

  218443.         *piCol = -1;

  218444.         return;

  218445.       }

  218446.       if( pIter->a[0]==0x01 ) break;

  218447.       pIter->a += fts5GetVarint32(pIter->a, dummy);

  218448.     }

  218449.     pIter->a += 1 + fts5GetVarint32(&pIter->a[1], *piCol);

  218450.   }

  218451. }

  218452. 

  218453. static int fts5ApiPhraseFirstColumn(

  218454.   Fts5Context *pCtx, 

  218455.   int iPhrase, 

  218456.   Fts5PhraseIter *pIter, 

  218457.   int *piCol

  218458. ){

  218459.   int rc = SQLITE_OK;

  218460.   Fts5Cursor *pCsr = (Fts5Cursor*)pCtx;

  218461.   Fts5Config *pConfig = ((Fts5Table*)(pCsr->base.pVtab))->pConfig;

  218462. 

  218463.   if( pConfig->eDetail==FTS5_DETAIL_COLUMNS ){

  218464.     Fts5Sorter *pSorter = pCsr->pSorter;

  218465.     int n;

  218466.     if( pSorter ){

  218467.       int i1 = (iPhrase==0 ? 0 : pSorter->aIdx[iPhrase-1]);

  218468.       n = pSorter->aIdx[iPhrase] - i1;

  218469.       pIter->a = &pSorter->aPoslist[i1];

  218470.     }else{

  218471.       rc = sqlite3Fts5ExprPhraseCollist(pCsr->pExpr, iPhrase, &pIter->a, &n);

  218472.     }

  218473.     if( rc==SQLITE_OK ){

  218474.       pIter->b = &pIter->a[n];

  218475.       *piCol = 0;

  218476.       fts5ApiPhraseNextColumn(pCtx, pIter, piCol);

  218477.     }

  218478.   }else{

  218479.     int n;

  218480.     rc = fts5CsrPoslist(pCsr, iPhrase, &pIter->a, &n);

  218481.     if( rc==SQLITE_OK ){

  218482.       pIter->b = &pIter->a[n];

  218483.       if( n<=0 ){

  218484.         *piCol = -1;

  218485.       }else if( pIter->a[0]==0x01 ){

  218486.         pIter->a += 1 + fts5GetVarint32(&pIter->a[1], *piCol);

  218487.       }else{

  218488.         *piCol = 0;

  218489.       }

  218490.     }

  218491.   }

  218492. 

  218493.   return rc;

  218494. }

  218495. 

  218496. 

  218497. static int fts5ApiQueryPhrase(Fts5Context*, int, void*, 

  218498.     int(*)(const Fts5ExtensionApi*, Fts5Context*, void*)

  218499. );

  218500. 

  218501. static const Fts5ExtensionApi sFts5Api = {

  218502.   2,                            /* iVersion */

  218503.   fts5ApiUserData,

  218504.   fts5ApiColumnCount,

  218505.   fts5ApiRowCount,

  218506.   fts5ApiColumnTotalSize,

  218507.   fts5ApiTokenize,

  218508.   fts5ApiPhraseCount,

  218509.   fts5ApiPhraseSize,

  218510.   fts5ApiInstCount,

  218511.   fts5ApiInst,

  218512.   fts5ApiRowid,

  218513.   fts5ApiColumnText,

  218514.   fts5ApiColumnSize,

  218515.   fts5ApiQueryPhrase,

  218516.   fts5ApiSetAuxdata,

  218517.   fts5ApiGetAuxdata,

  218518.   fts5ApiPhraseFirst,

  218519.   fts5ApiPhraseNext,

  218520.   fts5ApiPhraseFirstColumn,

  218521.   fts5ApiPhraseNextColumn,

  218522. };

  218523. 

  218524. /*

  218525. ** Implementation of API function xQueryPhrase().

  218526. */

  218527. static int fts5ApiQueryPhrase(

  218528.   Fts5Context *pCtx, 

  218529.   int iPhrase, 

  218530.   void *pUserData,

  218531.   int(*xCallback)(const Fts5ExtensionApi*, Fts5Context*, void*)

  218532. ){

  218533.   Fts5Cursor *pCsr = (Fts5Cursor*)pCtx;

  218534.   Fts5FullTable *pTab = (Fts5FullTable*)(pCsr->base.pVtab);

  218535.   int rc;

  218536.   Fts5Cursor *pNew = 0;

  218537. 

  218538.   rc = fts5OpenMethod(pCsr->base.pVtab, (sqlite3_vtab_cursor**)&pNew);

  218539.   if( rc==SQLITE_OK ){

  218540.     pNew->ePlan = FTS5_PLAN_MATCH;

  218541.     pNew->iFirstRowid = SMALLEST_INT64;

  218542.     pNew->iLastRowid = LARGEST_INT64;

  218543.     pNew->base.pVtab = (sqlite3_vtab*)pTab;

  218544.     rc = sqlite3Fts5ExprClonePhrase(pCsr->pExpr, iPhrase, &pNew->pExpr);

  218545.   }

  218546. 

  218547.   if( rc==SQLITE_OK ){

  218548.     for(rc = fts5CursorFirst(pTab, pNew, 0);

  218549.         rc==SQLITE_OK && CsrFlagTest(pNew, FTS5CSR_EOF)==0;

  218550.         rc = fts5NextMethod((sqlite3_vtab_cursor*)pNew)

  218551.     ){

  218552.       rc = xCallback(&sFts5Api, (Fts5Context*)pNew, pUserData);

  218553.       if( rc!=SQLITE_OK ){

  218554.         if( rc==SQLITE_DONE ) rc = SQLITE_OK;

  218555.         break;

  218556.       }

  218557.     }

  218558.   }

  218559. 

  218560.   fts5CloseMethod((sqlite3_vtab_cursor*)pNew);

  218561.   return rc;

  218562. }

  218563. 

  218564. static void fts5ApiInvoke(

  218565.   Fts5Auxiliary *pAux,

  218566.   Fts5Cursor *pCsr,

  218567.   sqlite3_context *context,

  218568.   int argc,

  218569.   sqlite3_value **argv

  218570. ){

  218571.   assert( pCsr->pAux==0 );

  218572.   pCsr->pAux = pAux;

  218573.   pAux->xFunc(&sFts5Api, (Fts5Context*)pCsr, context, argc, argv);

  218574.   pCsr->pAux = 0;

  218575. }

  218576. 

  218577. static Fts5Cursor *fts5CursorFromCsrid(Fts5Global *pGlobal, i64 iCsrId){

  218578.   Fts5Cursor *pCsr;

  218579.   for(pCsr=pGlobal->pCsr; pCsr; pCsr=pCsr->pNext){

  218580.     if( pCsr->iCsrId==iCsrId ) break;

  218581.   }

  218582.   return pCsr;

  218583. }

  218584. 

  218585. static void fts5ApiCallback(

  218586.   sqlite3_context *context,

  218587.   int argc,

  218588.   sqlite3_value **argv

  218589. ){

  218590. 

  218591.   Fts5Auxiliary *pAux;

  218592.   Fts5Cursor *pCsr;

  218593.   i64 iCsrId;

  218594. 

  218595.   assert( argc>=1 );

  218596.   pAux = (Fts5Auxiliary*)sqlite3_user_data(context);

  218597.   iCsrId = sqlite3_value_int64(argv[0]);

  218598. 

  218599.   pCsr = fts5CursorFromCsrid(pAux->pGlobal, iCsrId);

  218600.   if( pCsr==0 ){

  218601.     char *zErr = sqlite3_mprintf("no such cursor: %lld", iCsrId);

  218602.     sqlite3_result_error(context, zErr, -1);

  218603.     sqlite3_free(zErr);

  218604.   }else{

  218605.     fts5ApiInvoke(pAux, pCsr, context, argc-1, &argv[1]);

  218606.   }

  218607. }

  218608. 

  218609. 

  218610. /*

  218611. ** Given cursor id iId, return a pointer to the corresponding Fts5Table 

  218612. ** object. Or NULL If the cursor id does not exist.

  218613. */

  218614. static Fts5Table *sqlite3Fts5TableFromCsrid(

  218615.   Fts5Global *pGlobal,            /* FTS5 global context for db handle */

  218616.   i64 iCsrId                      /* Id of cursor to find */

  218617. ){

  218618.   Fts5Cursor *pCsr;

  218619.   pCsr = fts5CursorFromCsrid(pGlobal, iCsrId);

  218620.   if( pCsr ){

  218621.     return (Fts5Table*)pCsr->base.pVtab;

  218622.   }

  218623.   return 0;

  218624. }

  218625. 

  218626. /*

  218627. ** Return a "position-list blob" corresponding to the current position of

  218628. ** cursor pCsr via sqlite3_result_blob(). A position-list blob contains

  218629. ** the current position-list for each phrase in the query associated with

  218630. ** cursor pCsr.

  218631. **

  218632. ** A position-list blob begins with (nPhrase-1) varints, where nPhrase is

  218633. ** the number of phrases in the query. Following the varints are the

  218634. ** concatenated position lists for each phrase, in order.

  218635. **

  218636. ** The first varint (if it exists) contains the size of the position list

  218637. ** for phrase 0. The second (same disclaimer) contains the size of position

  218638. ** list 1. And so on. There is no size field for the final position list,

  218639. ** as it can be derived from the total size of the blob.

  218640. */

  218641. static int fts5PoslistBlob(sqlite3_context *pCtx, Fts5Cursor *pCsr){

  218642.   int i;

  218643.   int rc = SQLITE_OK;

  218644.   int nPhrase = sqlite3Fts5ExprPhraseCount(pCsr->pExpr);

  218645.   Fts5Buffer val;

  218646. 

  218647.   memset(&val, 0, sizeof(Fts5Buffer));

  218648.   switch( ((Fts5Table*)(pCsr->base.pVtab))->pConfig->eDetail ){

  218649.     case FTS5_DETAIL_FULL:

  218650. 

  218651.       /* Append the varints */

  218652.       for(i=0; i<(nPhrase-1); i++){

  218653.         const u8 *dummy;

  218654.         int nByte = sqlite3Fts5ExprPoslist(pCsr->pExpr, i, &dummy);

  218655.         sqlite3Fts5BufferAppendVarint(&rc, &val, nByte);

  218656.       }

  218657. 

  218658.       /* Append the position lists */

  218659.       for(i=0; i<nPhrase; i++){

  218660.         const u8 *pPoslist;

  218661.         int nPoslist;

  218662.         nPoslist = sqlite3Fts5ExprPoslist(pCsr->pExpr, i, &pPoslist);

  218663.         sqlite3Fts5BufferAppendBlob(&rc, &val, nPoslist, pPoslist);

  218664.       }

  218665.       break;

  218666. 

  218667.     case FTS5_DETAIL_COLUMNS:

  218668. 

  218669.       /* Append the varints */

  218670.       for(i=0; rc==SQLITE_OK && i<(nPhrase-1); i++){

  218671.         const u8 *dummy;

  218672.         int nByte;

  218673.         rc = sqlite3Fts5ExprPhraseCollist(pCsr->pExpr, i, &dummy, &nByte);

  218674.         sqlite3Fts5BufferAppendVarint(&rc, &val, nByte);

  218675.       }

  218676. 

  218677.       /* Append the position lists */

  218678.       for(i=0; rc==SQLITE_OK && i<nPhrase; i++){

  218679.         const u8 *pPoslist;

  218680.         int nPoslist;

  218681.         rc = sqlite3Fts5ExprPhraseCollist(pCsr->pExpr, i, &pPoslist, &nPoslist);

  218682.         sqlite3Fts5BufferAppendBlob(&rc, &val, nPoslist, pPoslist);

  218683.       }

  218684.       break;

  218685. 

  218686.     default:

  218687.       break;

  218688.   }

  218689. 

  218690.   sqlite3_result_blob(pCtx, val.p, val.n, sqlite3_free);

  218691.   return rc;

  218692. }

  218693. 

  218694. /* 

  218695. ** This is the xColumn method, called by SQLite to request a value from

  218696. ** the row that the supplied cursor currently points to.

  218697. */

  218698. static int fts5ColumnMethod(

  218699.   sqlite3_vtab_cursor *pCursor,   /* Cursor to retrieve value from */

  218700.   sqlite3_context *pCtx,          /* Context for sqlite3_result_xxx() calls */

  218701.   int iCol                        /* Index of column to read value from */

  218702. ){

  218703.   Fts5FullTable *pTab = (Fts5FullTable*)(pCursor->pVtab);

  218704.   Fts5Config *pConfig = pTab->p.pConfig;

  218705.   Fts5Cursor *pCsr = (Fts5Cursor*)pCursor;

  218706.   int rc = SQLITE_OK;

  218707.   

  218708.   assert( CsrFlagTest(pCsr, FTS5CSR_EOF)==0 );

  218709. 

  218710.   if( pCsr->ePlan==FTS5_PLAN_SPECIAL ){

  218711.     if( iCol==pConfig->nCol ){

  218712.       sqlite3_result_int64(pCtx, pCsr->iSpecial);

  218713.     }

  218714.   }else

  218715. 

  218716.   if( iCol==pConfig->nCol ){

  218717.     /* User is requesting the value of the special column with the same name

  218718.     ** as the table. Return the cursor integer id number. This value is only

  218719.     ** useful in that it may be passed as the first argument to an FTS5

  218720.     ** auxiliary function.  */

  218721.     sqlite3_result_int64(pCtx, pCsr->iCsrId);

  218722.   }else if( iCol==pConfig->nCol+1 ){

  218723. 

  218724.     /* The value of the "rank" column. */

  218725.     if( pCsr->ePlan==FTS5_PLAN_SOURCE ){

  218726.       fts5PoslistBlob(pCtx, pCsr);

  218727.     }else if( 

  218728.         pCsr->ePlan==FTS5_PLAN_MATCH

  218729.      || pCsr->ePlan==FTS5_PLAN_SORTED_MATCH

  218730.     ){

  218731.       if( pCsr->pRank || SQLITE_OK==(rc = fts5FindRankFunction(pCsr)) ){

  218732.         fts5ApiInvoke(pCsr->pRank, pCsr, pCtx, pCsr->nRankArg, pCsr->apRankArg);

  218733.       }

  218734.     }

  218735.   }else if( !fts5IsContentless(pTab) ){

  218736.     rc = fts5SeekCursor(pCsr, 1);

  218737.     if( rc==SQLITE_OK ){

  218738.       sqlite3_result_value(pCtx, sqlite3_column_value(pCsr->pStmt, iCol+1));

  218739.     }

  218740.   }

  218741.   return rc;

  218742. }

  218743. 

  218744. 

  218745. /*

  218746. ** This routine implements the xFindFunction method for the FTS3

  218747. ** virtual table.

  218748. */

  218749. static int fts5FindFunctionMethod(

  218750.   sqlite3_vtab *pVtab,            /* Virtual table handle */

  218751.   int nUnused,                    /* Number of SQL function arguments */

  218752.   const char *zName,              /* Name of SQL function */

  218753.   void (**pxFunc)(sqlite3_context*,int,sqlite3_value**), /* OUT: Result */

  218754.   void **ppArg                    /* OUT: User data for *pxFunc */

  218755. ){

  218756.   Fts5FullTable *pTab = (Fts5FullTable*)pVtab;

  218757.   Fts5Auxiliary *pAux;

  218758. 

  218759.   UNUSED_PARAM(nUnused);

  218760.   pAux = fts5FindAuxiliary(pTab, zName);

  218761.   if( pAux ){

  218762.     *pxFunc = fts5ApiCallback;

  218763.     *ppArg = (void*)pAux;

  218764.     return 1;

  218765.   }

  218766. 

  218767.   /* No function of the specified name was found. Return 0. */

  218768.   return 0;

  218769. }

  218770. 

  218771. /*

  218772. ** Implementation of FTS5 xRename method. Rename an fts5 table.

  218773. */

  218774. static int fts5RenameMethod(

  218775.   sqlite3_vtab *pVtab,            /* Virtual table handle */

  218776.   const char *zName               /* New name of table */

  218777. ){

  218778.   Fts5FullTable *pTab = (Fts5FullTable*)pVtab;

  218779.   return sqlite3Fts5StorageRename(pTab->pStorage, zName);

  218780. }

  218781. 

  218782. static int sqlite3Fts5FlushToDisk(Fts5Table *pTab){

  218783.   fts5TripCursors((Fts5FullTable*)pTab);

  218784.   return sqlite3Fts5StorageSync(((Fts5FullTable*)pTab)->pStorage);

  218785. }

  218786. 

  218787. /*

  218788. ** The xSavepoint() method.

  218789. **

  218790. ** Flush the contents of the pending-terms table to disk.

  218791. */

  218792. static int fts5SavepointMethod(sqlite3_vtab *pVtab, int iSavepoint){

  218793.   UNUSED_PARAM(iSavepoint);  /* Call below is a no-op for NDEBUG builds */

  218794.   fts5CheckTransactionState((Fts5FullTable*)pVtab, FTS5_SAVEPOINT, iSavepoint);

  218795.   return sqlite3Fts5FlushToDisk((Fts5Table*)pVtab);

  218796. }

  218797. 

  218798. /*

  218799. ** The xRelease() method.

  218800. **

  218801. ** This is a no-op.

  218802. */

  218803. static int fts5ReleaseMethod(sqlite3_vtab *pVtab, int iSavepoint){

  218804.   UNUSED_PARAM(iSavepoint);  /* Call below is a no-op for NDEBUG builds */

  218805.   fts5CheckTransactionState((Fts5FullTable*)pVtab, FTS5_RELEASE, iSavepoint);

  218806.   return sqlite3Fts5FlushToDisk((Fts5Table*)pVtab);

  218807. }

  218808. 

  218809. /*

  218810. ** The xRollbackTo() method.

  218811. **

  218812. ** Discard the contents of the pending terms table.

  218813. */

  218814. static int fts5RollbackToMethod(sqlite3_vtab *pVtab, int iSavepoint){

  218815.   Fts5FullTable *pTab = (Fts5FullTable*)pVtab;

  218816.   UNUSED_PARAM(iSavepoint);  /* Call below is a no-op for NDEBUG builds */

  218817.   fts5CheckTransactionState(pTab, FTS5_ROLLBACKTO, iSavepoint);

  218818.   fts5TripCursors(pTab);

  218819.   return sqlite3Fts5StorageRollback(pTab->pStorage);

  218820. }

  218821. 

  218822. /*

  218823. ** Register a new auxiliary function with global context pGlobal.

  218824. */

  218825. static int fts5CreateAux(

  218826.   fts5_api *pApi,                 /* Global context (one per db handle) */

  218827.   const char *zName,              /* Name of new function */

  218828.   void *pUserData,                /* User data for aux. function */

  218829.   fts5_extension_function xFunc,  /* Aux. function implementation */

  218830.   void(*xDestroy)(void*)          /* Destructor for pUserData */

  218831. ){

  218832.   Fts5Global *pGlobal = (Fts5Global*)pApi;

  218833.   int rc = sqlite3_overload_function(pGlobal->db, zName, -1);

  218834.   if( rc==SQLITE_OK ){

  218835.     Fts5Auxiliary *pAux;

  218836.     sqlite3_int64 nName;            /* Size of zName in bytes, including \0 */

  218837.     sqlite3_int64 nByte;            /* Bytes of space to allocate */

  218838. 

  218839.     nName = strlen(zName) + 1;

  218840.     nByte = sizeof(Fts5Auxiliary) + nName;

  218841.     pAux = (Fts5Auxiliary*)sqlite3_malloc64(nByte);

  218842.     if( pAux ){

  218843.       memset(pAux, 0, (size_t)nByte);

  218844.       pAux->zFunc = (char*)&pAux[1];

  218845.       memcpy(pAux->zFunc, zName, nName);

  218846.       pAux->pGlobal = pGlobal;

  218847.       pAux->pUserData = pUserData;

  218848.       pAux->xFunc = xFunc;

  218849.       pAux->xDestroy = xDestroy;

  218850.       pAux->pNext = pGlobal->pAux;

  218851.       pGlobal->pAux = pAux;

  218852.     }else{

  218853.       rc = SQLITE_NOMEM;

  218854.     }

  218855.   }

  218856. 

  218857.   return rc;

  218858. }

  218859. 

  218860. /*

  218861. ** Register a new tokenizer. This is the implementation of the 

  218862. ** fts5_api.xCreateTokenizer() method.

  218863. */

  218864. static int fts5CreateTokenizer(

  218865.   fts5_api *pApi,                 /* Global context (one per db handle) */

  218866.   const char *zName,              /* Name of new function */

  218867.   void *pUserData,                /* User data for aux. function */

  218868.   fts5_tokenizer *pTokenizer,     /* Tokenizer implementation */

  218869.   void(*xDestroy)(void*)          /* Destructor for pUserData */

  218870. ){

  218871.   Fts5Global *pGlobal = (Fts5Global*)pApi;

  218872.   Fts5TokenizerModule *pNew;

  218873.   sqlite3_int64 nName;            /* Size of zName and its \0 terminator */

  218874.   sqlite3_int64 nByte;            /* Bytes of space to allocate */

  218875.   int rc = SQLITE_OK;

  218876. 

  218877.   nName = strlen(zName) + 1;

  218878.   nByte = sizeof(Fts5TokenizerModule) + nName;

  218879.   pNew = (Fts5TokenizerModule*)sqlite3_malloc64(nByte);

  218880.   if( pNew ){

  218881.     memset(pNew, 0, (size_t)nByte);

  218882.     pNew->zName = (char*)&pNew[1];

  218883.     memcpy(pNew->zName, zName, nName);

  218884.     pNew->pUserData = pUserData;

  218885.     pNew->x = *pTokenizer;

  218886.     pNew->xDestroy = xDestroy;

  218887.     pNew->pNext = pGlobal->pTok;

  218888.     pGlobal->pTok = pNew;

  218889.     if( pNew->pNext==0 ){

  218890.       pGlobal->pDfltTok = pNew;

  218891.     }

  218892.   }else{

  218893.     rc = SQLITE_NOMEM;

  218894.   }

  218895. 

  218896.   return rc;

  218897. }

  218898. 

  218899. static Fts5TokenizerModule *fts5LocateTokenizer(

  218900.   Fts5Global *pGlobal, 

  218901.   const char *zName

  218902. ){

  218903.   Fts5TokenizerModule *pMod = 0;

  218904. 

  218905.   if( zName==0 ){

  218906.     pMod = pGlobal->pDfltTok;

  218907.   }else{

  218908.     for(pMod=pGlobal->pTok; pMod; pMod=pMod->pNext){

  218909.       if( sqlite3_stricmp(zName, pMod->zName)==0 ) break;

  218910.     }

  218911.   }

  218912. 

  218913.   return pMod;

  218914. }

  218915. 

  218916. /*

  218917. ** Find a tokenizer. This is the implementation of the 

  218918. ** fts5_api.xFindTokenizer() method.

  218919. */

  218920. static int fts5FindTokenizer(

  218921.   fts5_api *pApi,                 /* Global context (one per db handle) */

  218922.   const char *zName,              /* Name of new function */

  218923.   void **ppUserData,

  218924.   fts5_tokenizer *pTokenizer      /* Populate this object */

  218925. ){

  218926.   int rc = SQLITE_OK;

  218927.   Fts5TokenizerModule *pMod;

  218928. 

  218929.   pMod = fts5LocateTokenizer((Fts5Global*)pApi, zName);

  218930.   if( pMod ){

  218931.     *pTokenizer = pMod->x;

  218932.     *ppUserData = pMod->pUserData;

  218933.   }else{

  218934.     memset(pTokenizer, 0, sizeof(fts5_tokenizer));

  218935.     rc = SQLITE_ERROR;

  218936.   }

  218937. 

  218938.   return rc;

  218939. }

  218940. 

  218941. static int sqlite3Fts5GetTokenizer(

  218942.   Fts5Global *pGlobal, 

  218943.   const char **azArg,

  218944.   int nArg,

  218945.   Fts5Tokenizer **ppTok,

  218946.   fts5_tokenizer **ppTokApi,

  218947.   char **pzErr

  218948. ){

  218949.   Fts5TokenizerModule *pMod;

  218950.   int rc = SQLITE_OK;

  218951. 

  218952.   pMod = fts5LocateTokenizer(pGlobal, nArg==0 ? 0 : azArg[0]);

  218953.   if( pMod==0 ){

  218954.     assert( nArg>0 );

  218955.     rc = SQLITE_ERROR;

  218956.     *pzErr = sqlite3_mprintf("no such tokenizer: %s", azArg[0]);

  218957.   }else{

  218958.     rc = pMod->x.xCreate(pMod->pUserData, &azArg[1], (nArg?nArg-1:0), ppTok);

  218959.     *ppTokApi = &pMod->x;

  218960.     if( rc!=SQLITE_OK && pzErr ){

  218961.       *pzErr = sqlite3_mprintf("error in tokenizer constructor");

  218962.     }

  218963.   }

  218964. 

  218965.   if( rc!=SQLITE_OK ){

  218966.     *ppTokApi = 0;

  218967.     *ppTok = 0;

  218968.   }

  218969. 

  218970.   return rc;

  218971. }

  218972. 

  218973. static void fts5ModuleDestroy(void *pCtx){

  218974.   Fts5TokenizerModule *pTok, *pNextTok;

  218975.   Fts5Auxiliary *pAux, *pNextAux;

  218976.   Fts5Global *pGlobal = (Fts5Global*)pCtx;

  218977. 

  218978.   for(pAux=pGlobal->pAux; pAux; pAux=pNextAux){

  218979.     pNextAux = pAux->pNext;

  218980.     if( pAux->xDestroy ) pAux->xDestroy(pAux->pUserData);

  218981.     sqlite3_free(pAux);

  218982.   }

  218983. 

  218984.   for(pTok=pGlobal->pTok; pTok; pTok=pNextTok){

  218985.     pNextTok = pTok->pNext;

  218986.     if( pTok->xDestroy ) pTok->xDestroy(pTok->pUserData);

  218987.     sqlite3_free(pTok);

  218988.   }

  218989. 

  218990.   sqlite3_free(pGlobal);

  218991. }

  218992. 

  218993. static void fts5Fts5Func(

  218994.   sqlite3_context *pCtx,          /* Function call context */

  218995.   int nArg,                       /* Number of args */

  218996.   sqlite3_value **apArg           /* Function arguments */

  218997. ){

  218998.   Fts5Global *pGlobal = (Fts5Global*)sqlite3_user_data(pCtx);

  218999.   fts5_api **ppApi;

  219000.   UNUSED_PARAM(nArg);

  219001.   assert( nArg==1 );

  219002.   ppApi = (fts5_api**)sqlite3_value_pointer(apArg[0], "fts5_api_ptr");

  219003.   if( ppApi ) *ppApi = &pGlobal->api;

  219004. }

  219005. 

  219006. /*

  219007. ** Implementation of fts5_source_id() function.

  219008. */

  219009. static void fts5SourceIdFunc(

  219010.   sqlite3_context *pCtx,          /* Function call context */

  219011.   int nArg,                       /* Number of args */

  219012.   sqlite3_value **apUnused        /* Function arguments */

  219013. ){

  219014.   assert( nArg==0 );

  219015.   UNUSED_PARAM2(nArg, apUnused);

  219016.   sqlite3_result_text(pCtx, "fts5: 2019-07-10 17:32:03 fc82b73eaac8b36950e527f12c4b5dc1e147e6f4ad2217ae43ad82882a88bfa6", -1, SQLITE_TRANSIENT);

  219017. }

  219018. 

  219019. /*

  219020. ** Return true if zName is the extension on one of the shadow tables used

  219021. ** by this module.

  219022. */

  219023. static int fts5ShadowName(const char *zName){

  219024.   static const char *azName[] = {

  219025.     "config", "content", "data", "docsize", "idx"

  219026.   };

  219027.   unsigned int i;

  219028.   for(i=0; i<sizeof(azName)/sizeof(azName[0]); i++){

  219029.     if( sqlite3_stricmp(zName, azName[i])==0 ) return 1;

  219030.   }

  219031.   return 0;

  219032. }

  219033. 

  219034. static int fts5Init(sqlite3 *db){

  219035.   static const sqlite3_module fts5Mod = {

  219036.     /* iVersion      */ 3,

  219037.     /* xCreate       */ fts5CreateMethod,

  219038.     /* xConnect      */ fts5ConnectMethod,

  219039.     /* xBestIndex    */ fts5BestIndexMethod,

  219040.     /* xDisconnect   */ fts5DisconnectMethod,

  219041.     /* xDestroy      */ fts5DestroyMethod,

  219042.     /* xOpen         */ fts5OpenMethod,

  219043.     /* xClose        */ fts5CloseMethod,

  219044.     /* xFilter       */ fts5FilterMethod,

  219045.     /* xNext         */ fts5NextMethod,

  219046.     /* xEof          */ fts5EofMethod,

  219047.     /* xColumn       */ fts5ColumnMethod,

  219048.     /* xRowid        */ fts5RowidMethod,

  219049.     /* xUpdate       */ fts5UpdateMethod,

  219050.     /* xBegin        */ fts5BeginMethod,

  219051.     /* xSync         */ fts5SyncMethod,

  219052.     /* xCommit       */ fts5CommitMethod,

  219053.     /* xRollback     */ fts5RollbackMethod,

  219054.     /* xFindFunction */ fts5FindFunctionMethod,

  219055.     /* xRename       */ fts5RenameMethod,

  219056.     /* xSavepoint    */ fts5SavepointMethod,

  219057.     /* xRelease      */ fts5ReleaseMethod,

  219058.     /* xRollbackTo   */ fts5RollbackToMethod,

  219059.     /* xShadowName   */ fts5ShadowName

  219060.   };

  219061. 

  219062.   int rc;

  219063.   Fts5Global *pGlobal = 0;

  219064. 

  219065.   pGlobal = (Fts5Global*)sqlite3_malloc(sizeof(Fts5Global));

  219066.   if( pGlobal==0 ){

  219067.     rc = SQLITE_NOMEM;

  219068.   }else{

  219069.     void *p = (void*)pGlobal;

  219070.     memset(pGlobal, 0, sizeof(Fts5Global));

  219071.     pGlobal->db = db;

  219072.     pGlobal->api.iVersion = 2;

  219073.     pGlobal->api.xCreateFunction = fts5CreateAux;

  219074.     pGlobal->api.xCreateTokenizer = fts5CreateTokenizer;

  219075.     pGlobal->api.xFindTokenizer = fts5FindTokenizer;

  219076.     rc = sqlite3_create_module_v2(db, "fts5", &fts5Mod, p, fts5ModuleDestroy);

  219077.     if( rc==SQLITE_OK ) rc = sqlite3Fts5IndexInit(db);

  219078.     if( rc==SQLITE_OK ) rc = sqlite3Fts5ExprInit(pGlobal, db);

  219079.     if( rc==SQLITE_OK ) rc = sqlite3Fts5AuxInit(&pGlobal->api);

  219080.     if( rc==SQLITE_OK ) rc = sqlite3Fts5TokenizerInit(&pGlobal->api);

  219081.     if( rc==SQLITE_OK ) rc = sqlite3Fts5VocabInit(pGlobal, db);

  219082.     if( rc==SQLITE_OK ){

  219083.       rc = sqlite3_create_function(

  219084.           db, "fts5", 1, SQLITE_UTF8, p, fts5Fts5Func, 0, 0

  219085.       );

  219086.     }

  219087.     if( rc==SQLITE_OK ){

  219088.       rc = sqlite3_create_function(

  219089.           db, "fts5_source_id", 0, SQLITE_UTF8, p, fts5SourceIdFunc, 0, 0

  219090.       );

  219091.     }

  219092.   }

  219093. 

  219094.   /* If SQLITE_FTS5_ENABLE_TEST_MI is defined, assume that the file

  219095.   ** fts5_test_mi.c is compiled and linked into the executable. And call

  219096.   ** its entry point to enable the matchinfo() demo.  */

  219097. #ifdef SQLITE_FTS5_ENABLE_TEST_MI

  219098.   if( rc==SQLITE_OK ){

  219099.     extern int sqlite3Fts5TestRegisterMatchinfo(sqlite3*);

  219100.     rc = sqlite3Fts5TestRegisterMatchinfo(db);

  219101.   }

  219102. #endif

  219103. 

  219104.   return rc;

  219105. }

  219106. 

  219107. /*

  219108. ** The following functions are used to register the module with SQLite. If

  219109. ** this module is being built as part of the SQLite core (SQLITE_CORE is

  219110. ** defined), then sqlite3_open() will call sqlite3Fts5Init() directly.

  219111. **

  219112. ** Or, if this module is being built as a loadable extension, 

  219113. ** sqlite3Fts5Init() is omitted and the two standard entry points

  219114. ** sqlite3_fts_init() and sqlite3_fts5_init() defined instead.

  219115. */

  219116. #ifndef SQLITE_CORE

  219117. #ifdef _WIN32

  219118. __declspec(dllexport)

  219119. #endif

  219120. SQLITE_API int sqlite3_fts_init(

  219121.   sqlite3 *db,

  219122.   char **pzErrMsg,

  219123.   const sqlite3_api_routines *pApi

  219124. ){

  219125.   SQLITE_EXTENSION_INIT2(pApi);

  219126.   (void)pzErrMsg;  /* Unused parameter */

  219127.   return fts5Init(db);

  219128. }

  219129. 

  219130. #ifdef _WIN32

  219131. __declspec(dllexport)

  219132. #endif

  219133. SQLITE_API int sqlite3_fts5_init(

  219134.   sqlite3 *db,

  219135.   char **pzErrMsg,

  219136.   const sqlite3_api_routines *pApi

  219137. ){

  219138.   SQLITE_EXTENSION_INIT2(pApi);

  219139.   (void)pzErrMsg;  /* Unused parameter */

  219140.   return fts5Init(db);

  219141. }

  219142. #else

  219143. SQLITE_PRIVATE int sqlite3Fts5Init(sqlite3 *db){

  219144.   return fts5Init(db);

  219145. }

  219146. #endif

  219147. 

  219148. /*

  219149. ** 2014 May 31

  219150. **

  219151. ** The author disclaims copyright to this source code.  In place of

  219152. ** a legal notice, here is a blessing:

  219153. **

  219154. **    May you do good and not evil.

  219155. **    May you find forgiveness for yourself and forgive others.

  219156. **    May you share freely, never taking more than you give.

  219157. **

  219158. ******************************************************************************

  219159. **

  219160. */

  219161. 

  219162. 

  219163. 

  219164. /* #include "fts5Int.h" */

  219165. 

  219166. struct Fts5Storage {

  219167.   Fts5Config *pConfig;

  219168.   Fts5Index *pIndex;

  219169.   int bTotalsValid;               /* True if nTotalRow/aTotalSize[] are valid */

  219170.   i64 nTotalRow;                  /* Total number of rows in FTS table */

  219171.   i64 *aTotalSize;                /* Total sizes of each column */ 

  219172.   sqlite3_stmt *aStmt[11];

  219173. };

  219174. 

  219175. 

  219176. #if FTS5_STMT_SCAN_ASC!=0 

  219177. # error "FTS5_STMT_SCAN_ASC mismatch" 

  219178. #endif

  219179. #if FTS5_STMT_SCAN_DESC!=1 

  219180. # error "FTS5_STMT_SCAN_DESC mismatch" 

  219181. #endif

  219182. #if FTS5_STMT_LOOKUP!=2

  219183. # error "FTS5_STMT_LOOKUP mismatch" 

  219184. #endif

  219185. 

  219186. #define FTS5_STMT_INSERT_CONTENT  3

  219187. #define FTS5_STMT_REPLACE_CONTENT 4

  219188. #define FTS5_STMT_DELETE_CONTENT  5

  219189. #define FTS5_STMT_REPLACE_DOCSIZE  6

  219190. #define FTS5_STMT_DELETE_DOCSIZE  7

  219191. #define FTS5_STMT_LOOKUP_DOCSIZE  8

  219192. #define FTS5_STMT_REPLACE_CONFIG 9

  219193. #define FTS5_STMT_SCAN 10

  219194. 

  219195. /*

  219196. ** Prepare the two insert statements - Fts5Storage.pInsertContent and

  219197. ** Fts5Storage.pInsertDocsize - if they have not already been prepared.

  219198. ** Return SQLITE_OK if successful, or an SQLite error code if an error

  219199. ** occurs.

  219200. */

  219201. static int fts5StorageGetStmt(

  219202.   Fts5Storage *p,                 /* Storage handle */

  219203.   int eStmt,                      /* FTS5_STMT_XXX constant */

  219204.   sqlite3_stmt **ppStmt,          /* OUT: Prepared statement handle */

  219205.   char **pzErrMsg                 /* OUT: Error message (if any) */

  219206. ){

  219207.   int rc = SQLITE_OK;

  219208. 

  219209.   /* If there is no %_docsize table, there should be no requests for 

  219210.   ** statements to operate on it.  */

  219211.   assert( p->pConfig->bColumnsize || (

  219212.         eStmt!=FTS5_STMT_REPLACE_DOCSIZE 

  219213.      && eStmt!=FTS5_STMT_DELETE_DOCSIZE 

  219214.      && eStmt!=FTS5_STMT_LOOKUP_DOCSIZE 

  219215.   ));

  219216. 

  219217.   assert( eStmt>=0 && eStmt<ArraySize(p->aStmt) );

  219218.   if( p->aStmt[eStmt]==0 ){

  219219.     const char *azStmt[] = {

  219220.       "SELECT %s FROM %s T WHERE T.%Q >= ? AND T.%Q <= ? ORDER BY T.%Q ASC",

  219221.       "SELECT %s FROM %s T WHERE T.%Q <= ? AND T.%Q >= ? ORDER BY T.%Q DESC",

  219222.       "SELECT %s FROM %s T WHERE T.%Q=?",               /* LOOKUP  */

  219223. 

  219224.       "INSERT INTO %Q.'%q_content' VALUES(%s)",         /* INSERT_CONTENT  */

  219225.       "REPLACE INTO %Q.'%q_content' VALUES(%s)",        /* REPLACE_CONTENT */

  219226.       "DELETE FROM %Q.'%q_content' WHERE id=?",         /* DELETE_CONTENT  */

  219227.       "REPLACE INTO %Q.'%q_docsize' VALUES(?,?)",       /* REPLACE_DOCSIZE  */

  219228.       "DELETE FROM %Q.'%q_docsize' WHERE id=?",         /* DELETE_DOCSIZE  */

  219229. 

  219230.       "SELECT sz FROM %Q.'%q_docsize' WHERE id=?",      /* LOOKUP_DOCSIZE  */

  219231. 

  219232.       "REPLACE INTO %Q.'%q_config' VALUES(?,?)",        /* REPLACE_CONFIG */

  219233.       "SELECT %s FROM %s AS T",                         /* SCAN */

  219234.     };

  219235.     Fts5Config *pC = p->pConfig;

  219236.     char *zSql = 0;

  219237. 

  219238.     switch( eStmt ){

  219239.       case FTS5_STMT_SCAN:

  219240.         zSql = sqlite3_mprintf(azStmt[eStmt], 

  219241.             pC->zContentExprlist, pC->zContent

  219242.         );

  219243.         break;

  219244. 

  219245.       case FTS5_STMT_SCAN_ASC:

  219246.       case FTS5_STMT_SCAN_DESC:

  219247.         zSql = sqlite3_mprintf(azStmt[eStmt], pC->zContentExprlist, 

  219248.             pC->zContent, pC->zContentRowid, pC->zContentRowid,

  219249.             pC->zContentRowid

  219250.         );

  219251.         break;

  219252. 

  219253.       case FTS5_STMT_LOOKUP:

  219254.         zSql = sqlite3_mprintf(azStmt[eStmt], 

  219255.             pC->zContentExprlist, pC->zContent, pC->zContentRowid

  219256.         );

  219257.         break;

  219258. 

  219259.       case FTS5_STMT_INSERT_CONTENT: 

  219260.       case FTS5_STMT_REPLACE_CONTENT: {

  219261.         int nCol = pC->nCol + 1;

  219262.         char *zBind;

  219263.         int i;

  219264. 

  219265.         zBind = sqlite3_malloc64(1 + nCol*2);

  219266.         if( zBind ){

  219267.           for(i=0; i<nCol; i++){

  219268.             zBind[i*2] = '?';

  219269.             zBind[i*2 + 1] = ',';

  219270.           }

  219271.           zBind[i*2-1] = '\0';

  219272.           zSql = sqlite3_mprintf(azStmt[eStmt], pC->zDb, pC->zName, zBind);

  219273.           sqlite3_free(zBind);

  219274.         }

  219275.         break;

  219276.       }

  219277. 

  219278.       default:

  219279.         zSql = sqlite3_mprintf(azStmt[eStmt], pC->zDb, pC->zName);

  219280.         break;

  219281.     }

  219282. 

  219283.     if( zSql==0 ){

  219284.       rc = SQLITE_NOMEM;

  219285.     }else{

  219286.       int f = SQLITE_PREPARE_PERSISTENT;

  219287.       if( eStmt>FTS5_STMT_LOOKUP ) f |= SQLITE_PREPARE_NO_VTAB;

  219288.       rc = sqlite3_prepare_v3(pC->db, zSql, -1, f, &p->aStmt[eStmt], 0);

  219289.       sqlite3_free(zSql);

  219290.       if( rc!=SQLITE_OK && pzErrMsg ){

  219291.         *pzErrMsg = sqlite3_mprintf("%s", sqlite3_errmsg(pC->db));

  219292.       }

  219293.     }

  219294.   }

  219295. 

  219296.   *ppStmt = p->aStmt[eStmt];

  219297.   sqlite3_reset(*ppStmt);

  219298.   return rc;

  219299. }

  219300. 

  219301. 

  219302. static int fts5ExecPrintf(

  219303.   sqlite3 *db,

  219304.   char **pzErr,

  219305.   const char *zFormat,

  219306.   ...

  219307. ){

  219308.   int rc;

  219309.   va_list ap;                     /* ... printf arguments */

  219310.   char *zSql;

  219311. 

  219312.   va_start(ap, zFormat);

  219313.   zSql = sqlite3_vmprintf(zFormat, ap);

  219314. 

  219315.   if( zSql==0 ){

  219316.     rc = SQLITE_NOMEM;

  219317.   }else{

  219318.     rc = sqlite3_exec(db, zSql, 0, 0, pzErr);

  219319.     sqlite3_free(zSql);

  219320.   }

  219321. 

  219322.   va_end(ap);

  219323.   return rc;

  219324. }

  219325. 

  219326. /*

  219327. ** Drop all shadow tables. Return SQLITE_OK if successful or an SQLite error

  219328. ** code otherwise.

  219329. */

  219330. static int sqlite3Fts5DropAll(Fts5Config *pConfig){

  219331.   int rc = fts5ExecPrintf(pConfig->db, 0, 

  219332.       "DROP TABLE IF EXISTS %Q.'%q_data';"

  219333.       "DROP TABLE IF EXISTS %Q.'%q_idx';"

  219334.       "DROP TABLE IF EXISTS %Q.'%q_config';",

  219335.       pConfig->zDb, pConfig->zName,

  219336.       pConfig->zDb, pConfig->zName,

  219337.       pConfig->zDb, pConfig->zName

  219338.   );

  219339.   if( rc==SQLITE_OK && pConfig->bColumnsize ){

  219340.     rc = fts5ExecPrintf(pConfig->db, 0, 

  219341.         "DROP TABLE IF EXISTS %Q.'%q_docsize';",

  219342.         pConfig->zDb, pConfig->zName

  219343.     );

  219344.   }

  219345.   if( rc==SQLITE_OK && pConfig->eContent==FTS5_CONTENT_NORMAL ){

  219346.     rc = fts5ExecPrintf(pConfig->db, 0, 

  219347.         "DROP TABLE IF EXISTS %Q.'%q_content';",

  219348.         pConfig->zDb, pConfig->zName

  219349.     );

  219350.   }

  219351.   return rc;

  219352. }

  219353. 

  219354. static void fts5StorageRenameOne(

  219355.   Fts5Config *pConfig,            /* Current FTS5 configuration */

  219356.   int *pRc,                       /* IN/OUT: Error code */

  219357.   const char *zTail,              /* Tail of table name e.g. "data", "config" */

  219358.   const char *zName               /* New name of FTS5 table */

  219359. ){

  219360.   if( *pRc==SQLITE_OK ){

  219361.     *pRc = fts5ExecPrintf(pConfig->db, 0, 

  219362.         "ALTER TABLE %Q.'%q_%s' RENAME TO '%q_%s';",

  219363.         pConfig->zDb, pConfig->zName, zTail, zName, zTail

  219364.     );

  219365.   }

  219366. }

  219367. 

  219368. static int sqlite3Fts5StorageRename(Fts5Storage *pStorage, const char *zName){

  219369.   Fts5Config *pConfig = pStorage->pConfig;

  219370.   int rc = sqlite3Fts5StorageSync(pStorage);

  219371. 

  219372.   fts5StorageRenameOne(pConfig, &rc, "data", zName);

  219373.   fts5StorageRenameOne(pConfig, &rc, "idx", zName);

  219374.   fts5StorageRenameOne(pConfig, &rc, "config", zName);

  219375.   if( pConfig->bColumnsize ){

  219376.     fts5StorageRenameOne(pConfig, &rc, "docsize", zName);

  219377.   }

  219378.   if( pConfig->eContent==FTS5_CONTENT_NORMAL ){

  219379.     fts5StorageRenameOne(pConfig, &rc, "content", zName);

  219380.   }

  219381.   return rc;

  219382. }

  219383. 

  219384. /*

  219385. ** Create the shadow table named zPost, with definition zDefn. Return

  219386. ** SQLITE_OK if successful, or an SQLite error code otherwise.

  219387. */

  219388. static int sqlite3Fts5CreateTable(

  219389.   Fts5Config *pConfig,            /* FTS5 configuration */

  219390.   const char *zPost,              /* Shadow table to create (e.g. "content") */

  219391.   const char *zDefn,              /* Columns etc. for shadow table */

  219392.   int bWithout,                   /* True for without rowid */

  219393.   char **pzErr                    /* OUT: Error message */

  219394. ){

  219395.   int rc;

  219396.   char *zErr = 0;

  219397. 

  219398.   rc = fts5ExecPrintf(pConfig->db, &zErr, "CREATE TABLE %Q.'%q_%q'(%s)%s",

  219399.       pConfig->zDb, pConfig->zName, zPost, zDefn, 

  219400. #ifndef SQLITE_FTS5_NO_WITHOUT_ROWID

  219401.       bWithout?" WITHOUT ROWID":

  219402. #endif

  219403.       ""

  219404.   );

  219405.   if( zErr ){

  219406.     *pzErr = sqlite3_mprintf(

  219407.         "fts5: error creating shadow table %q_%s: %s", 

  219408.         pConfig->zName, zPost, zErr

  219409.     );

  219410.     sqlite3_free(zErr);

  219411.   }

  219412. 

  219413.   return rc;

  219414. }

  219415. 

  219416. /*

  219417. ** Open a new Fts5Index handle. If the bCreate argument is true, create

  219418. ** and initialize the underlying tables 

  219419. **

  219420. ** If successful, set *pp to point to the new object and return SQLITE_OK.

  219421. ** Otherwise, set *pp to NULL and return an SQLite error code.

  219422. */

  219423. static int sqlite3Fts5StorageOpen(

  219424.   Fts5Config *pConfig, 

  219425.   Fts5Index *pIndex, 

  219426.   int bCreate, 

  219427.   Fts5Storage **pp,

  219428.   char **pzErr                    /* OUT: Error message */

  219429. ){

  219430.   int rc = SQLITE_OK;

  219431.   Fts5Storage *p;                 /* New object */

  219432.   sqlite3_int64 nByte;            /* Bytes of space to allocate */

  219433. 

  219434.   nByte = sizeof(Fts5Storage)               /* Fts5Storage object */

  219435.         + pConfig->nCol * sizeof(i64);      /* Fts5Storage.aTotalSize[] */

  219436.   *pp = p = (Fts5Storage*)sqlite3_malloc64(nByte);

  219437.   if( !p ) return SQLITE_NOMEM;

  219438. 

  219439.   memset(p, 0, (size_t)nByte);

  219440.   p->aTotalSize = (i64*)&p[1];

  219441.   p->pConfig = pConfig;

  219442.   p->pIndex = pIndex;

  219443. 

  219444.   if( bCreate ){

  219445.     if( pConfig->eContent==FTS5_CONTENT_NORMAL ){

  219446.       int nDefn = 32 + pConfig->nCol*10;

  219447.       char *zDefn = sqlite3_malloc64(32 + (sqlite3_int64)pConfig->nCol * 10);

  219448.       if( zDefn==0 ){

  219449.         rc = SQLITE_NOMEM;

  219450.       }else{

  219451.         int i;

  219452.         int iOff;

  219453.         sqlite3_snprintf(nDefn, zDefn, "id INTEGER PRIMARY KEY");

  219454.         iOff = (int)strlen(zDefn);

  219455.         for(i=0; i<pConfig->nCol; i++){

  219456.           sqlite3_snprintf(nDefn-iOff, &zDefn[iOff], ", c%d", i);

  219457.           iOff += (int)strlen(&zDefn[iOff]);

  219458.         }

  219459.         rc = sqlite3Fts5CreateTable(pConfig, "content", zDefn, 0, pzErr);

  219460.       }

  219461.       sqlite3_free(zDefn);

  219462.     }

  219463. 

  219464.     if( rc==SQLITE_OK && pConfig->bColumnsize ){

  219465.       rc = sqlite3Fts5CreateTable(

  219466.           pConfig, "docsize", "id INTEGER PRIMARY KEY, sz BLOB", 0, pzErr

  219467.       );

  219468.     }

  219469.     if( rc==SQLITE_OK ){

  219470.       rc = sqlite3Fts5CreateTable(

  219471.           pConfig, "config", "k PRIMARY KEY, v", 1, pzErr

  219472.       );

  219473.     }

  219474.     if( rc==SQLITE_OK ){

  219475.       rc = sqlite3Fts5StorageConfigValue(p, "version", 0, FTS5_CURRENT_VERSION);

  219476.     }

  219477.   }

  219478. 

  219479.   if( rc ){

  219480.     sqlite3Fts5StorageClose(p);

  219481.     *pp = 0;

  219482.   }

  219483.   return rc;

  219484. }

  219485. 

  219486. /*

  219487. ** Close a handle opened by an earlier call to sqlite3Fts5StorageOpen().

  219488. */

  219489. static int sqlite3Fts5StorageClose(Fts5Storage *p){

  219490.   int rc = SQLITE_OK;

  219491.   if( p ){

  219492.     int i;

  219493. 

  219494.     /* Finalize all SQL statements */

  219495.     for(i=0; i<ArraySize(p->aStmt); i++){

  219496.       sqlite3_finalize(p->aStmt[i]);

  219497.     }

  219498. 

  219499.     sqlite3_free(p);

  219500.   }

  219501.   return rc;

  219502. }

  219503. 

  219504. typedef struct Fts5InsertCtx Fts5InsertCtx;

  219505. struct Fts5InsertCtx {

  219506.   Fts5Storage *pStorage;

  219507.   int iCol;

  219508.   int szCol;                      /* Size of column value in tokens */

  219509. };

  219510. 

  219511. /*

  219512. ** Tokenization callback used when inserting tokens into the FTS index.

  219513. */

  219514. static int fts5StorageInsertCallback(

  219515.   void *pContext,                 /* Pointer to Fts5InsertCtx object */

  219516.   int tflags,

  219517.   const char *pToken,             /* Buffer containing token */

  219518.   int nToken,                     /* Size of token in bytes */

  219519.   int iUnused1,                   /* Start offset of token */

  219520.   int iUnused2                    /* End offset of token */

  219521. ){

  219522.   Fts5InsertCtx *pCtx = (Fts5InsertCtx*)pContext;

  219523.   Fts5Index *pIdx = pCtx->pStorage->pIndex;

  219524.   UNUSED_PARAM2(iUnused1, iUnused2);

  219525.   if( nToken>FTS5_MAX_TOKEN_SIZE ) nToken = FTS5_MAX_TOKEN_SIZE;

  219526.   if( (tflags & FTS5_TOKEN_COLOCATED)==0 || pCtx->szCol==0 ){

  219527.     pCtx->szCol++;

  219528.   }

  219529.   return sqlite3Fts5IndexWrite(pIdx, pCtx->iCol, pCtx->szCol-1, pToken, nToken);

  219530. }

  219531. 

  219532. /*

  219533. ** If a row with rowid iDel is present in the %_content table, add the

  219534. ** delete-markers to the FTS index necessary to delete it. Do not actually

  219535. ** remove the %_content row at this time though.

  219536. */

  219537. static int fts5StorageDeleteFromIndex(

  219538.   Fts5Storage *p, 

  219539.   i64 iDel, 

  219540.   sqlite3_value **apVal

  219541. ){

  219542.   Fts5Config *pConfig = p->pConfig;

  219543.   sqlite3_stmt *pSeek = 0;        /* SELECT to read row iDel from %_data */

  219544.   int rc;                         /* Return code */

  219545.   int rc2;                        /* sqlite3_reset() return code */

  219546.   int iCol;

  219547.   Fts5InsertCtx ctx;

  219548. 

  219549.   if( apVal==0 ){

  219550.     rc = fts5StorageGetStmt(p, FTS5_STMT_LOOKUP, &pSeek, 0);

  219551.     if( rc!=SQLITE_OK ) return rc;

  219552.     sqlite3_bind_int64(pSeek, 1, iDel);

  219553.     if( sqlite3_step(pSeek)!=SQLITE_ROW ){

  219554.       return sqlite3_reset(pSeek);

  219555.     }

  219556.   }

  219557. 

  219558.   ctx.pStorage = p;

  219559.   ctx.iCol = -1;

  219560.   rc = sqlite3Fts5IndexBeginWrite(p->pIndex, 1, iDel);

  219561.   for(iCol=1; rc==SQLITE_OK && iCol<=pConfig->nCol; iCol++){

  219562.     if( pConfig->abUnindexed[iCol-1]==0 ){

  219563.       const char *zText;

  219564.       int nText;

  219565.       if( pSeek ){

  219566.         zText = (const char*)sqlite3_column_text(pSeek, iCol);

  219567.         nText = sqlite3_column_bytes(pSeek, iCol);

  219568.       }else{

  219569.         zText = (const char*)sqlite3_value_text(apVal[iCol-1]);

  219570.         nText = sqlite3_value_bytes(apVal[iCol-1]);

  219571.       }

  219572.       ctx.szCol = 0;

  219573.       rc = sqlite3Fts5Tokenize(pConfig, FTS5_TOKENIZE_DOCUMENT, 

  219574.           zText, nText, (void*)&ctx, fts5StorageInsertCallback

  219575.       );

  219576.       p->aTotalSize[iCol-1] -= (i64)ctx.szCol;

  219577.     }

  219578.   }

  219579.   p->nTotalRow--;

  219580. 

  219581.   rc2 = sqlite3_reset(pSeek);

  219582.   if( rc==SQLITE_OK ) rc = rc2;

  219583.   return rc;

  219584. }

  219585. 

  219586. 

  219587. /*

  219588. ** Insert a record into the %_docsize table. Specifically, do:

  219589. **

  219590. **   INSERT OR REPLACE INTO %_docsize(id, sz) VALUES(iRowid, pBuf);

  219591. **

  219592. ** If there is no %_docsize table (as happens if the columnsize=0 option

  219593. ** is specified when the FTS5 table is created), this function is a no-op.

  219594. */

  219595. static int fts5StorageInsertDocsize(

  219596.   Fts5Storage *p,                 /* Storage module to write to */

  219597.   i64 iRowid,                     /* id value */

  219598.   Fts5Buffer *pBuf                /* sz value */

  219599. ){

  219600.   int rc = SQLITE_OK;

  219601.   if( p->pConfig->bColumnsize ){

  219602.     sqlite3_stmt *pReplace = 0;

  219603.     rc = fts5StorageGetStmt(p, FTS5_STMT_REPLACE_DOCSIZE, &pReplace, 0);

  219604.     if( rc==SQLITE_OK ){

  219605.       sqlite3_bind_int64(pReplace, 1, iRowid);

  219606.       sqlite3_bind_blob(pReplace, 2, pBuf->p, pBuf->n, SQLITE_STATIC);

  219607.       sqlite3_step(pReplace);

  219608.       rc = sqlite3_reset(pReplace);

  219609.       sqlite3_bind_null(pReplace, 2);

  219610.     }

  219611.   }

  219612.   return rc;

  219613. }

  219614. 

  219615. /*

  219616. ** Load the contents of the "averages" record from disk into the 

  219617. ** p->nTotalRow and p->aTotalSize[] variables. If successful, and if

  219618. ** argument bCache is true, set the p->bTotalsValid flag to indicate

  219619. ** that the contents of aTotalSize[] and nTotalRow are valid until

  219620. ** further notice.

  219621. **

  219622. ** Return SQLITE_OK if successful, or an SQLite error code if an error

  219623. ** occurs.

  219624. */

  219625. static int fts5StorageLoadTotals(Fts5Storage *p, int bCache){

  219626.   int rc = SQLITE_OK;

  219627.   if( p->bTotalsValid==0 ){

  219628.     rc = sqlite3Fts5IndexGetAverages(p->pIndex, &p->nTotalRow, p->aTotalSize);

  219629.     p->bTotalsValid = bCache;

  219630.   }

  219631.   return rc;

  219632. }

  219633. 

  219634. /*

  219635. ** Store the current contents of the p->nTotalRow and p->aTotalSize[] 

  219636. ** variables in the "averages" record on disk.

  219637. **

  219638. ** Return SQLITE_OK if successful, or an SQLite error code if an error

  219639. ** occurs.

  219640. */

  219641. static int fts5StorageSaveTotals(Fts5Storage *p){

  219642.   int nCol = p->pConfig->nCol;

  219643.   int i;

  219644.   Fts5Buffer buf;

  219645.   int rc = SQLITE_OK;

  219646.   memset(&buf, 0, sizeof(buf));

  219647. 

  219648.   sqlite3Fts5BufferAppendVarint(&rc, &buf, p->nTotalRow);

  219649.   for(i=0; i<nCol; i++){

  219650.     sqlite3Fts5BufferAppendVarint(&rc, &buf, p->aTotalSize[i]);

  219651.   }

  219652.   if( rc==SQLITE_OK ){

  219653.     rc = sqlite3Fts5IndexSetAverages(p->pIndex, buf.p, buf.n);

  219654.   }

  219655.   sqlite3_free(buf.p);

  219656. 

  219657.   return rc;

  219658. }

  219659. 

  219660. /*

  219661. ** Remove a row from the FTS table.

  219662. */

  219663. static int sqlite3Fts5StorageDelete(Fts5Storage *p, i64 iDel, sqlite3_value **apVal){

  219664.   Fts5Config *pConfig = p->pConfig;

  219665.   int rc;

  219666.   sqlite3_stmt *pDel = 0;

  219667. 

  219668.   assert( pConfig->eContent!=FTS5_CONTENT_NORMAL || apVal==0 );

  219669.   rc = fts5StorageLoadTotals(p, 1);

  219670. 

  219671.   /* Delete the index records */

  219672.   if( rc==SQLITE_OK ){

  219673.     rc = fts5StorageDeleteFromIndex(p, iDel, apVal);

  219674.   }

  219675. 

  219676.   /* Delete the %_docsize record */

  219677.   if( rc==SQLITE_OK && pConfig->bColumnsize ){

  219678.     rc = fts5StorageGetStmt(p, FTS5_STMT_DELETE_DOCSIZE, &pDel, 0);

  219679.     if( rc==SQLITE_OK ){

  219680.       sqlite3_bind_int64(pDel, 1, iDel);

  219681.       sqlite3_step(pDel);

  219682.       rc = sqlite3_reset(pDel);

  219683.     }

  219684.   }

  219685. 

  219686.   /* Delete the %_content record */

  219687.   if( pConfig->eContent==FTS5_CONTENT_NORMAL ){

  219688.     if( rc==SQLITE_OK ){

  219689.       rc = fts5StorageGetStmt(p, FTS5_STMT_DELETE_CONTENT, &pDel, 0);

  219690.     }

  219691.     if( rc==SQLITE_OK ){

  219692.       sqlite3_bind_int64(pDel, 1, iDel);

  219693.       sqlite3_step(pDel);

  219694.       rc = sqlite3_reset(pDel);

  219695.     }

  219696.   }

  219697. 

  219698.   return rc;

  219699. }

  219700. 

  219701. /*

  219702. ** Delete all entries in the FTS5 index.

  219703. */

  219704. static int sqlite3Fts5StorageDeleteAll(Fts5Storage *p){

  219705.   Fts5Config *pConfig = p->pConfig;

  219706.   int rc;

  219707. 

  219708.   /* Delete the contents of the %_data and %_docsize tables. */

  219709.   rc = fts5ExecPrintf(pConfig->db, 0,

  219710.       "DELETE FROM %Q.'%q_data';" 

  219711.       "DELETE FROM %Q.'%q_idx';",

  219712.       pConfig->zDb, pConfig->zName,

  219713.       pConfig->zDb, pConfig->zName

  219714.   );

  219715.   if( rc==SQLITE_OK && pConfig->bColumnsize ){

  219716.     rc = fts5ExecPrintf(pConfig->db, 0,

  219717.         "DELETE FROM %Q.'%q_docsize';",

  219718.         pConfig->zDb, pConfig->zName

  219719.     );

  219720.   }

  219721. 

  219722.   /* Reinitialize the %_data table. This call creates the initial structure

  219723.   ** and averages records.  */

  219724.   if( rc==SQLITE_OK ){

  219725.     rc = sqlite3Fts5IndexReinit(p->pIndex);

  219726.   }

  219727.   if( rc==SQLITE_OK ){

  219728.     rc = sqlite3Fts5StorageConfigValue(p, "version", 0, FTS5_CURRENT_VERSION);

  219729.   }

  219730.   return rc;

  219731. }

  219732. 

  219733. static int sqlite3Fts5StorageRebuild(Fts5Storage *p){

  219734.   Fts5Buffer buf = {0,0,0};

  219735.   Fts5Config *pConfig = p->pConfig;

  219736.   sqlite3_stmt *pScan = 0;

  219737.   Fts5InsertCtx ctx;

  219738.   int rc, rc2;

  219739. 

  219740.   memset(&ctx, 0, sizeof(Fts5InsertCtx));

  219741.   ctx.pStorage = p;

  219742.   rc = sqlite3Fts5StorageDeleteAll(p);

  219743.   if( rc==SQLITE_OK ){

  219744.     rc = fts5StorageLoadTotals(p, 1);

  219745.   }

  219746. 

  219747.   if( rc==SQLITE_OK ){

  219748.     rc = fts5StorageGetStmt(p, FTS5_STMT_SCAN, &pScan, 0);

  219749.   }

  219750. 

  219751.   while( rc==SQLITE_OK && SQLITE_ROW==sqlite3_step(pScan) ){

  219752.     i64 iRowid = sqlite3_column_int64(pScan, 0);

  219753. 

  219754.     sqlite3Fts5BufferZero(&buf);

  219755.     rc = sqlite3Fts5IndexBeginWrite(p->pIndex, 0, iRowid);

  219756.     for(ctx.iCol=0; rc==SQLITE_OK && ctx.iCol<pConfig->nCol; ctx.iCol++){

  219757.       ctx.szCol = 0;

  219758.       if( pConfig->abUnindexed[ctx.iCol]==0 ){

  219759.         rc = sqlite3Fts5Tokenize(pConfig, 

  219760.             FTS5_TOKENIZE_DOCUMENT,

  219761.             (const char*)sqlite3_column_text(pScan, ctx.iCol+1),

  219762.             sqlite3_column_bytes(pScan, ctx.iCol+1),

  219763.             (void*)&ctx,

  219764.             fts5StorageInsertCallback

  219765.         );

  219766.       }

  219767.       sqlite3Fts5BufferAppendVarint(&rc, &buf, ctx.szCol);

  219768.       p->aTotalSize[ctx.iCol] += (i64)ctx.szCol;

  219769.     }

  219770.     p->nTotalRow++;

  219771. 

  219772.     if( rc==SQLITE_OK ){

  219773.       rc = fts5StorageInsertDocsize(p, iRowid, &buf);

  219774.     }

  219775.   }

  219776.   sqlite3_free(buf.p);

  219777.   rc2 = sqlite3_reset(pScan);

  219778.   if( rc==SQLITE_OK ) rc = rc2;

  219779. 

  219780.   /* Write the averages record */

  219781.   if( rc==SQLITE_OK ){

  219782.     rc = fts5StorageSaveTotals(p);

  219783.   }

  219784.   return rc;

  219785. }

  219786. 

  219787. static int sqlite3Fts5StorageOptimize(Fts5Storage *p){

  219788.   return sqlite3Fts5IndexOptimize(p->pIndex);

  219789. }

  219790. 

  219791. static int sqlite3Fts5StorageMerge(Fts5Storage *p, int nMerge){

  219792.   return sqlite3Fts5IndexMerge(p->pIndex, nMerge);

  219793. }

  219794. 

  219795. static int sqlite3Fts5StorageReset(Fts5Storage *p){

  219796.   return sqlite3Fts5IndexReset(p->pIndex);

  219797. }

  219798. 

  219799. /*

  219800. ** Allocate a new rowid. This is used for "external content" tables when

  219801. ** a NULL value is inserted into the rowid column. The new rowid is allocated

  219802. ** by inserting a dummy row into the %_docsize table. The dummy will be

  219803. ** overwritten later.

  219804. **

  219805. ** If the %_docsize table does not exist, SQLITE_MISMATCH is returned. In

  219806. ** this case the user is required to provide a rowid explicitly.

  219807. */

  219808. static int fts5StorageNewRowid(Fts5Storage *p, i64 *piRowid){

  219809.   int rc = SQLITE_MISMATCH;

  219810.   if( p->pConfig->bColumnsize ){

  219811.     sqlite3_stmt *pReplace = 0;

  219812.     rc = fts5StorageGetStmt(p, FTS5_STMT_REPLACE_DOCSIZE, &pReplace, 0);

  219813.     if( rc==SQLITE_OK ){

  219814.       sqlite3_bind_null(pReplace, 1);

  219815.       sqlite3_bind_null(pReplace, 2);

  219816.       sqlite3_step(pReplace);

  219817.       rc = sqlite3_reset(pReplace);

  219818.     }

  219819.     if( rc==SQLITE_OK ){

  219820.       *piRowid = sqlite3_last_insert_rowid(p->pConfig->db);

  219821.     }

  219822.   }

  219823.   return rc;

  219824. }

  219825. 

  219826. /*

  219827. ** Insert a new row into the FTS content table.

  219828. */

  219829. static int sqlite3Fts5StorageContentInsert(

  219830.   Fts5Storage *p, 

  219831.   sqlite3_value **apVal, 

  219832.   i64 *piRowid

  219833. ){

  219834.   Fts5Config *pConfig = p->pConfig;

  219835.   int rc = SQLITE_OK;

  219836. 

  219837.   /* Insert the new row into the %_content table. */

  219838.   if( pConfig->eContent!=FTS5_CONTENT_NORMAL ){

  219839.     if( sqlite3_value_type(apVal[1])==SQLITE_INTEGER ){

  219840.       *piRowid = sqlite3_value_int64(apVal[1]);

  219841.     }else{

  219842.       rc = fts5StorageNewRowid(p, piRowid);

  219843.     }

  219844.   }else{

  219845.     sqlite3_stmt *pInsert = 0;    /* Statement to write %_content table */

  219846.     int i;                        /* Counter variable */

  219847.     rc = fts5StorageGetStmt(p, FTS5_STMT_INSERT_CONTENT, &pInsert, 0);

  219848.     for(i=1; rc==SQLITE_OK && i<=pConfig->nCol+1; i++){

  219849.       rc = sqlite3_bind_value(pInsert, i, apVal[i]);

  219850.     }

  219851.     if( rc==SQLITE_OK ){

  219852.       sqlite3_step(pInsert);

  219853.       rc = sqlite3_reset(pInsert);

  219854.     }

  219855.     *piRowid = sqlite3_last_insert_rowid(pConfig->db);

  219856.   }

  219857. 

  219858.   return rc;

  219859. }

  219860. 

  219861. /*

  219862. ** Insert new entries into the FTS index and %_docsize table.

  219863. */

  219864. static int sqlite3Fts5StorageIndexInsert(

  219865.   Fts5Storage *p, 

  219866.   sqlite3_value **apVal, 

  219867.   i64 iRowid

  219868. ){

  219869.   Fts5Config *pConfig = p->pConfig;

  219870.   int rc = SQLITE_OK;             /* Return code */

  219871.   Fts5InsertCtx ctx;              /* Tokenization callback context object */

  219872.   Fts5Buffer buf;                 /* Buffer used to build up %_docsize blob */

  219873. 

  219874.   memset(&buf, 0, sizeof(Fts5Buffer));

  219875.   ctx.pStorage = p;

  219876.   rc = fts5StorageLoadTotals(p, 1);

  219877. 

  219878.   if( rc==SQLITE_OK ){

  219879.     rc = sqlite3Fts5IndexBeginWrite(p->pIndex, 0, iRowid);

  219880.   }

  219881.   for(ctx.iCol=0; rc==SQLITE_OK && ctx.iCol<pConfig->nCol; ctx.iCol++){

  219882.     ctx.szCol = 0;

  219883.     if( pConfig->abUnindexed[ctx.iCol]==0 ){

  219884.       rc = sqlite3Fts5Tokenize(pConfig, 

  219885.           FTS5_TOKENIZE_DOCUMENT,

  219886.           (const char*)sqlite3_value_text(apVal[ctx.iCol+2]),

  219887.           sqlite3_value_bytes(apVal[ctx.iCol+2]),

  219888.           (void*)&ctx,

  219889.           fts5StorageInsertCallback

  219890.       );

  219891.     }

  219892.     sqlite3Fts5BufferAppendVarint(&rc, &buf, ctx.szCol);

  219893.     p->aTotalSize[ctx.iCol] += (i64)ctx.szCol;

  219894.   }

  219895.   p->nTotalRow++;

  219896. 

  219897.   /* Write the %_docsize record */

  219898.   if( rc==SQLITE_OK ){

  219899.     rc = fts5StorageInsertDocsize(p, iRowid, &buf);

  219900.   }

  219901.   sqlite3_free(buf.p);

  219902. 

  219903.   return rc;

  219904. }

  219905. 

  219906. static int fts5StorageCount(Fts5Storage *p, const char *zSuffix, i64 *pnRow){

  219907.   Fts5Config *pConfig = p->pConfig;

  219908.   char *zSql;

  219909.   int rc;

  219910. 

  219911.   zSql = sqlite3_mprintf("SELECT count(*) FROM %Q.'%q_%s'", 

  219912.       pConfig->zDb, pConfig->zName, zSuffix

  219913.   );

  219914.   if( zSql==0 ){

  219915.     rc = SQLITE_NOMEM;

  219916.   }else{

  219917.     sqlite3_stmt *pCnt = 0;

  219918.     rc = sqlite3_prepare_v2(pConfig->db, zSql, -1, &pCnt, 0);

  219919.     if( rc==SQLITE_OK ){

  219920.       if( SQLITE_ROW==sqlite3_step(pCnt) ){

  219921.         *pnRow = sqlite3_column_int64(pCnt, 0);

  219922.       }

  219923.       rc = sqlite3_finalize(pCnt);

  219924.     }

  219925.   }

  219926. 

  219927.   sqlite3_free(zSql);

  219928.   return rc;

  219929. }

  219930. 

  219931. /*

  219932. ** Context object used by sqlite3Fts5StorageIntegrity().

  219933. */

  219934. typedef struct Fts5IntegrityCtx Fts5IntegrityCtx;

  219935. struct Fts5IntegrityCtx {

  219936.   i64 iRowid;

  219937.   int iCol;

  219938.   int szCol;

  219939.   u64 cksum;

  219940.   Fts5Termset *pTermset;

  219941.   Fts5Config *pConfig;

  219942. };

  219943. 

  219944. 

  219945. /*

  219946. ** Tokenization callback used by integrity check.

  219947. */

  219948. static int fts5StorageIntegrityCallback(

  219949.   void *pContext,                 /* Pointer to Fts5IntegrityCtx object */

  219950.   int tflags,

  219951.   const char *pToken,             /* Buffer containing token */

  219952.   int nToken,                     /* Size of token in bytes */

  219953.   int iUnused1,                   /* Start offset of token */

  219954.   int iUnused2                    /* End offset of token */

  219955. ){

  219956.   Fts5IntegrityCtx *pCtx = (Fts5IntegrityCtx*)pContext;

  219957.   Fts5Termset *pTermset = pCtx->pTermset;

  219958.   int bPresent;

  219959.   int ii;

  219960.   int rc = SQLITE_OK;

  219961.   int iPos;

  219962.   int iCol;

  219963. 

  219964.   UNUSED_PARAM2(iUnused1, iUnused2);

  219965.   if( nToken>FTS5_MAX_TOKEN_SIZE ) nToken = FTS5_MAX_TOKEN_SIZE;

  219966. 

  219967.   if( (tflags & FTS5_TOKEN_COLOCATED)==0 || pCtx->szCol==0 ){

  219968.     pCtx->szCol++;

  219969.   }

  219970. 

  219971.   switch( pCtx->pConfig->eDetail ){

  219972.     case FTS5_DETAIL_FULL:

  219973.       iPos = pCtx->szCol-1;

  219974.       iCol = pCtx->iCol;

  219975.       break;

  219976. 

  219977.     case FTS5_DETAIL_COLUMNS:

  219978.       iPos = pCtx->iCol;

  219979.       iCol = 0;

  219980.       break;

  219981. 

  219982.     default:

  219983.       assert( pCtx->pConfig->eDetail==FTS5_DETAIL_NONE );

  219984.       iPos = 0;

  219985.       iCol = 0;

  219986.       break;

  219987.   }

  219988. 

  219989.   rc = sqlite3Fts5TermsetAdd(pTermset, 0, pToken, nToken, &bPresent);

  219990.   if( rc==SQLITE_OK && bPresent==0 ){

  219991.     pCtx->cksum ^= sqlite3Fts5IndexEntryCksum(

  219992.         pCtx->iRowid, iCol, iPos, 0, pToken, nToken

  219993.     );

  219994.   }

  219995. 

  219996.   for(ii=0; rc==SQLITE_OK && ii<pCtx->pConfig->nPrefix; ii++){

  219997.     const int nChar = pCtx->pConfig->aPrefix[ii];

  219998.     int nByte = sqlite3Fts5IndexCharlenToBytelen(pToken, nToken, nChar);

  219999.     if( nByte ){

  220000.       rc = sqlite3Fts5TermsetAdd(pTermset, ii+1, pToken, nByte, &bPresent);

  220001.       if( bPresent==0 ){

  220002.         pCtx->cksum ^= sqlite3Fts5IndexEntryCksum(

  220003.             pCtx->iRowid, iCol, iPos, ii+1, pToken, nByte

  220004.         );

  220005.       }

  220006.     }

  220007.   }

  220008. 

  220009.   return rc;

  220010. }

  220011. 

  220012. /*

  220013. ** Check that the contents of the FTS index match that of the %_content

  220014. ** table. Return SQLITE_OK if they do, or SQLITE_CORRUPT if not. Return

  220015. ** some other SQLite error code if an error occurs while attempting to

  220016. ** determine this.

  220017. */

  220018. static int sqlite3Fts5StorageIntegrity(Fts5Storage *p){

  220019.   Fts5Config *pConfig = p->pConfig;

  220020.   int rc;                         /* Return code */

  220021.   int *aColSize;                  /* Array of size pConfig->nCol */

  220022.   i64 *aTotalSize;                /* Array of size pConfig->nCol */

  220023.   Fts5IntegrityCtx ctx;

  220024.   sqlite3_stmt *pScan;

  220025. 

  220026.   memset(&ctx, 0, sizeof(Fts5IntegrityCtx));

  220027.   ctx.pConfig = p->pConfig;

  220028.   aTotalSize = (i64*)sqlite3_malloc64(pConfig->nCol*(sizeof(int)+sizeof(i64)));

  220029.   if( !aTotalSize ) return SQLITE_NOMEM;

  220030.   aColSize = (int*)&aTotalSize[pConfig->nCol];

  220031.   memset(aTotalSize, 0, sizeof(i64) * pConfig->nCol);

  220032. 

  220033.   /* Generate the expected index checksum based on the contents of the

  220034.   ** %_content table. This block stores the checksum in ctx.cksum. */

  220035.   rc = fts5StorageGetStmt(p, FTS5_STMT_SCAN, &pScan, 0);

  220036.   if( rc==SQLITE_OK ){

  220037.     int rc2;

  220038.     while( SQLITE_ROW==sqlite3_step(pScan) ){

  220039.       int i;

  220040.       ctx.iRowid = sqlite3_column_int64(pScan, 0);

  220041.       ctx.szCol = 0;

  220042.       if( pConfig->bColumnsize ){

  220043.         rc = sqlite3Fts5StorageDocsize(p, ctx.iRowid, aColSize);

  220044.       }

  220045.       if( rc==SQLITE_OK && pConfig->eDetail==FTS5_DETAIL_NONE ){

  220046.         rc = sqlite3Fts5TermsetNew(&ctx.pTermset);

  220047.       }

  220048.       for(i=0; rc==SQLITE_OK && i<pConfig->nCol; i++){

  220049.         if( pConfig->abUnindexed[i] ) continue;

  220050.         ctx.iCol = i;

  220051.         ctx.szCol = 0;

  220052.         if( pConfig->eDetail==FTS5_DETAIL_COLUMNS ){

  220053.           rc = sqlite3Fts5TermsetNew(&ctx.pTermset);

  220054.         }

  220055.         if( rc==SQLITE_OK ){

  220056.           rc = sqlite3Fts5Tokenize(pConfig, 

  220057.               FTS5_TOKENIZE_DOCUMENT,

  220058.               (const char*)sqlite3_column_text(pScan, i+1),

  220059.               sqlite3_column_bytes(pScan, i+1),

  220060.               (void*)&ctx,

  220061.               fts5StorageIntegrityCallback

  220062.           );

  220063.         }

  220064.         if( rc==SQLITE_OK && pConfig->bColumnsize && ctx.szCol!=aColSize[i] ){

  220065.           rc = FTS5_CORRUPT;

  220066.         }

  220067.         aTotalSize[i] += ctx.szCol;

  220068.         if( pConfig->eDetail==FTS5_DETAIL_COLUMNS ){

  220069.           sqlite3Fts5TermsetFree(ctx.pTermset);

  220070.           ctx.pTermset = 0;

  220071.         }

  220072.       }

  220073.       sqlite3Fts5TermsetFree(ctx.pTermset);

  220074.       ctx.pTermset = 0;

  220075. 

  220076.       if( rc!=SQLITE_OK ) break;

  220077.     }

  220078.     rc2 = sqlite3_reset(pScan);

  220079.     if( rc==SQLITE_OK ) rc = rc2;

  220080.   }

  220081. 

  220082.   /* Test that the "totals" (sometimes called "averages") record looks Ok */

  220083.   if( rc==SQLITE_OK ){

  220084.     int i;

  220085.     rc = fts5StorageLoadTotals(p, 0);

  220086.     for(i=0; rc==SQLITE_OK && i<pConfig->nCol; i++){

  220087.       if( p->aTotalSize[i]!=aTotalSize[i] ) rc = FTS5_CORRUPT;

  220088.     }

  220089.   }

  220090. 

  220091.   /* Check that the %_docsize and %_content tables contain the expected

  220092.   ** number of rows.  */

  220093.   if( rc==SQLITE_OK && pConfig->eContent==FTS5_CONTENT_NORMAL ){

  220094.     i64 nRow = 0;

  220095.     rc = fts5StorageCount(p, "content", &nRow);

  220096.     if( rc==SQLITE_OK && nRow!=p->nTotalRow ) rc = FTS5_CORRUPT;

  220097.   }

  220098.   if( rc==SQLITE_OK && pConfig->bColumnsize ){

  220099.     i64 nRow = 0;

  220100.     rc = fts5StorageCount(p, "docsize", &nRow);

  220101.     if( rc==SQLITE_OK && nRow!=p->nTotalRow ) rc = FTS5_CORRUPT;

  220102.   }

  220103. 

  220104.   /* Pass the expected checksum down to the FTS index module. It will

  220105.   ** verify, amongst other things, that it matches the checksum generated by

  220106.   ** inspecting the index itself.  */

  220107.   if( rc==SQLITE_OK ){

  220108.     rc = sqlite3Fts5IndexIntegrityCheck(p->pIndex, ctx.cksum);

  220109.   }

  220110. 

  220111.   sqlite3_free(aTotalSize);

  220112.   return rc;

  220113. }

  220114. 

  220115. /*

  220116. ** Obtain an SQLite statement handle that may be used to read data from the

  220117. ** %_content table.

  220118. */

  220119. static int sqlite3Fts5StorageStmt(

  220120.   Fts5Storage *p, 

  220121.   int eStmt, 

  220122.   sqlite3_stmt **pp, 

  220123.   char **pzErrMsg

  220124. ){

  220125.   int rc;

  220126.   assert( eStmt==FTS5_STMT_SCAN_ASC 

  220127.        || eStmt==FTS5_STMT_SCAN_DESC

  220128.        || eStmt==FTS5_STMT_LOOKUP

  220129.   );

  220130.   rc = fts5StorageGetStmt(p, eStmt, pp, pzErrMsg);

  220131.   if( rc==SQLITE_OK ){

  220132.     assert( p->aStmt[eStmt]==*pp );

  220133.     p->aStmt[eStmt] = 0;

  220134.   }

  220135.   return rc;

  220136. }

  220137. 

  220138. /*

  220139. ** Release an SQLite statement handle obtained via an earlier call to

  220140. ** sqlite3Fts5StorageStmt(). The eStmt parameter passed to this function

  220141. ** must match that passed to the sqlite3Fts5StorageStmt() call.

  220142. */

  220143. static void sqlite3Fts5StorageStmtRelease(

  220144.   Fts5Storage *p, 

  220145.   int eStmt, 

  220146.   sqlite3_stmt *pStmt

  220147. ){

  220148.   assert( eStmt==FTS5_STMT_SCAN_ASC

  220149.        || eStmt==FTS5_STMT_SCAN_DESC

  220150.        || eStmt==FTS5_STMT_LOOKUP

  220151.   );

  220152.   if( p->aStmt[eStmt]==0 ){

  220153.     sqlite3_reset(pStmt);

  220154.     p->aStmt[eStmt] = pStmt;

  220155.   }else{

  220156.     sqlite3_finalize(pStmt);

  220157.   }

  220158. }

  220159. 

  220160. static int fts5StorageDecodeSizeArray(

  220161.   int *aCol, int nCol,            /* Array to populate */

  220162.   const u8 *aBlob, int nBlob      /* Record to read varints from */

  220163. ){

  220164.   int i;

  220165.   int iOff = 0;

  220166.   for(i=0; i<nCol; i++){

  220167.     if( iOff>=nBlob ) return 1;

  220168.     iOff += fts5GetVarint32(&aBlob[iOff], aCol[i]);

  220169.   }

  220170.   return (iOff!=nBlob);

  220171. }

  220172. 

  220173. /*

  220174. ** Argument aCol points to an array of integers containing one entry for

  220175. ** each table column. This function reads the %_docsize record for the

  220176. ** specified rowid and populates aCol[] with the results.

  220177. **

  220178. ** An SQLite error code is returned if an error occurs, or SQLITE_OK

  220179. ** otherwise.

  220180. */

  220181. static int sqlite3Fts5StorageDocsize(Fts5Storage *p, i64 iRowid, int *aCol){

  220182.   int nCol = p->pConfig->nCol;    /* Number of user columns in table */

  220183.   sqlite3_stmt *pLookup = 0;      /* Statement to query %_docsize */

  220184.   int rc;                         /* Return Code */

  220185. 

  220186.   assert( p->pConfig->bColumnsize );

  220187.   rc = fts5StorageGetStmt(p, FTS5_STMT_LOOKUP_DOCSIZE, &pLookup, 0);

  220188.   if( rc==SQLITE_OK ){

  220189.     int bCorrupt = 1;

  220190.     sqlite3_bind_int64(pLookup, 1, iRowid);

  220191.     if( SQLITE_ROW==sqlite3_step(pLookup) ){

  220192.       const u8 *aBlob = sqlite3_column_blob(pLookup, 0);

  220193.       int nBlob = sqlite3_column_bytes(pLookup, 0);

  220194.       if( 0==fts5StorageDecodeSizeArray(aCol, nCol, aBlob, nBlob) ){

  220195.         bCorrupt = 0;

  220196.       }

  220197.     }

  220198.     rc = sqlite3_reset(pLookup);

  220199.     if( bCorrupt && rc==SQLITE_OK ){

  220200.       rc = FTS5_CORRUPT;

  220201.     }

  220202.   }

  220203. 

  220204.   return rc;

  220205. }

  220206. 

  220207. static int sqlite3Fts5StorageSize(Fts5Storage *p, int iCol, i64 *pnToken){

  220208.   int rc = fts5StorageLoadTotals(p, 0);

  220209.   if( rc==SQLITE_OK ){

  220210.     *pnToken = 0;

  220211.     if( iCol<0 ){

  220212.       int i;

  220213.       for(i=0; i<p->pConfig->nCol; i++){

  220214.         *pnToken += p->aTotalSize[i];

  220215.       }

  220216.     }else if( iCol<p->pConfig->nCol ){

  220217.       *pnToken = p->aTotalSize[iCol];

  220218.     }else{

  220219.       rc = SQLITE_RANGE;

  220220.     }

  220221.   }

  220222.   return rc;

  220223. }

  220224. 

  220225. static int sqlite3Fts5StorageRowCount(Fts5Storage *p, i64 *pnRow){

  220226.   int rc = fts5StorageLoadTotals(p, 0);

  220227.   if( rc==SQLITE_OK ){

  220228.     /* nTotalRow being zero does not necessarily indicate a corrupt 

  220229.     ** database - it might be that the FTS5 table really does contain zero

  220230.     ** rows. However this function is only called from the xRowCount() API,

  220231.     ** and there is no way for that API to be invoked if the table contains

  220232.     ** no rows. Hence the FTS5_CORRUPT return.  */

  220233.     *pnRow = p->nTotalRow;

  220234.     if( p->nTotalRow<=0 ) rc = FTS5_CORRUPT;

  220235.   }

  220236.   return rc;

  220237. }

  220238. 

  220239. /*

  220240. ** Flush any data currently held in-memory to disk.

  220241. */

  220242. static int sqlite3Fts5StorageSync(Fts5Storage *p){

  220243.   int rc = SQLITE_OK;

  220244.   i64 iLastRowid = sqlite3_last_insert_rowid(p->pConfig->db);

  220245.   if( p->bTotalsValid ){

  220246.     rc = fts5StorageSaveTotals(p);

  220247.     p->bTotalsValid = 0;

  220248.   }

  220249.   if( rc==SQLITE_OK ){

  220250.     rc = sqlite3Fts5IndexSync(p->pIndex);

  220251.   }

  220252.   sqlite3_set_last_insert_rowid(p->pConfig->db, iLastRowid);

  220253.   return rc;

  220254. }

  220255. 

  220256. static int sqlite3Fts5StorageRollback(Fts5Storage *p){

  220257.   p->bTotalsValid = 0;

  220258.   return sqlite3Fts5IndexRollback(p->pIndex);

  220259. }

  220260. 

  220261. static int sqlite3Fts5StorageConfigValue(

  220262.   Fts5Storage *p, 

  220263.   const char *z,

  220264.   sqlite3_value *pVal,

  220265.   int iVal

  220266. ){

  220267.   sqlite3_stmt *pReplace = 0;

  220268.   int rc = fts5StorageGetStmt(p, FTS5_STMT_REPLACE_CONFIG, &pReplace, 0);

  220269.   if( rc==SQLITE_OK ){

  220270.     sqlite3_bind_text(pReplace, 1, z, -1, SQLITE_STATIC);

  220271.     if( pVal ){

  220272.       sqlite3_bind_value(pReplace, 2, pVal);

  220273.     }else{

  220274.       sqlite3_bind_int(pReplace, 2, iVal);

  220275.     }

  220276.     sqlite3_step(pReplace);

  220277.     rc = sqlite3_reset(pReplace);

  220278.     sqlite3_bind_null(pReplace, 1);

  220279.   }

  220280.   if( rc==SQLITE_OK && pVal ){

  220281.     int iNew = p->pConfig->iCookie + 1;

  220282.     rc = sqlite3Fts5IndexSetCookie(p->pIndex, iNew);

  220283.     if( rc==SQLITE_OK ){

  220284.       p->pConfig->iCookie = iNew;

  220285.     }

  220286.   }

  220287.   return rc;

  220288. }

  220289. 

  220290. /*

  220291. ** 2014 May 31

  220292. **

  220293. ** The author disclaims copyright to this source code.  In place of

  220294. ** a legal notice, here is a blessing:

  220295. **

  220296. **    May you do good and not evil.

  220297. **    May you find forgiveness for yourself and forgive others.

  220298. **    May you share freely, never taking more than you give.

  220299. **

  220300. ******************************************************************************

  220301. */

  220302. 

  220303. 

  220304. /* #include "fts5Int.h" */

  220305. 

  220306. /**************************************************************************

  220307. ** Start of ascii tokenizer implementation.

  220308. */

  220309. 

  220310. /*

  220311. ** For tokenizers with no "unicode" modifier, the set of token characters

  220312. ** is the same as the set of ASCII range alphanumeric characters. 

  220313. */

  220314. static unsigned char aAsciiTokenChar[128] = {

  220315.   0, 0, 0, 0, 0, 0, 0, 0,   0, 0, 0, 0, 0, 0, 0, 0,   /* 0x00..0x0F */

  220316.   0, 0, 0, 0, 0, 0, 0, 0,   0, 0, 0, 0, 0, 0, 0, 0,   /* 0x10..0x1F */

  220317.   0, 0, 0, 0, 0, 0, 0, 0,   0, 0, 0, 0, 0, 0, 0, 0,   /* 0x20..0x2F */

  220318.   1, 1, 1, 1, 1, 1, 1, 1,   1, 1, 0, 0, 0, 0, 0, 0,   /* 0x30..0x3F */

  220319.   0, 1, 1, 1, 1, 1, 1, 1,   1, 1, 1, 1, 1, 1, 1, 1,   /* 0x40..0x4F */

  220320.   1, 1, 1, 1, 1, 1, 1, 1,   1, 1, 1, 0, 0, 0, 0, 0,   /* 0x50..0x5F */

  220321.   0, 1, 1, 1, 1, 1, 1, 1,   1, 1, 1, 1, 1, 1, 1, 1,   /* 0x60..0x6F */

  220322.   1, 1, 1, 1, 1, 1, 1, 1,   1, 1, 1, 0, 0, 0, 0, 0,   /* 0x70..0x7F */

  220323. };

  220324. 

  220325. typedef struct AsciiTokenizer AsciiTokenizer;

  220326. struct AsciiTokenizer {

  220327.   unsigned char aTokenChar[128];

  220328. };

  220329. 

  220330. static void fts5AsciiAddExceptions(

  220331.   AsciiTokenizer *p, 

  220332.   const char *zArg, 

  220333.   int bTokenChars

  220334. ){

  220335.   int i;

  220336.   for(i=0; zArg[i]; i++){

  220337.     if( (zArg[i] & 0x80)==0 ){

  220338.       p->aTokenChar[(int)zArg[i]] = (unsigned char)bTokenChars;

  220339.     }

  220340.   }

  220341. }

  220342. 

  220343. /*

  220344. ** Delete a "ascii" tokenizer.

  220345. */

  220346. static void fts5AsciiDelete(Fts5Tokenizer *p){

  220347.   sqlite3_free(p);

  220348. }

  220349. 

  220350. /*

  220351. ** Create an "ascii" tokenizer.

  220352. */

  220353. static int fts5AsciiCreate(

  220354.   void *pUnused, 

  220355.   const char **azArg, int nArg,

  220356.   Fts5Tokenizer **ppOut

  220357. ){

  220358.   int rc = SQLITE_OK;

  220359.   AsciiTokenizer *p = 0;

  220360.   UNUSED_PARAM(pUnused);

  220361.   if( nArg%2 ){

  220362.     rc = SQLITE_ERROR;

  220363.   }else{

  220364.     p = sqlite3_malloc(sizeof(AsciiTokenizer));

  220365.     if( p==0 ){

  220366.       rc = SQLITE_NOMEM;

  220367.     }else{

  220368.       int i;

  220369.       memset(p, 0, sizeof(AsciiTokenizer));

  220370.       memcpy(p->aTokenChar, aAsciiTokenChar, sizeof(aAsciiTokenChar));

  220371.       for(i=0; rc==SQLITE_OK && i<nArg; i+=2){

  220372.         const char *zArg = azArg[i+1];

  220373.         if( 0==sqlite3_stricmp(azArg[i], "tokenchars") ){

  220374.           fts5AsciiAddExceptions(p, zArg, 1);

  220375.         }else

  220376.         if( 0==sqlite3_stricmp(azArg[i], "separators") ){

  220377.           fts5AsciiAddExceptions(p, zArg, 0);

  220378.         }else{

  220379.           rc = SQLITE_ERROR;

  220380.         }

  220381.       }

  220382.       if( rc!=SQLITE_OK ){

  220383.         fts5AsciiDelete((Fts5Tokenizer*)p);

  220384.         p = 0;

  220385.       }

  220386.     }

  220387.   }

  220388. 

  220389.   *ppOut = (Fts5Tokenizer*)p;

  220390.   return rc;

  220391. }

  220392. 

  220393. 

  220394. static void asciiFold(char *aOut, const char *aIn, int nByte){

  220395.   int i;

  220396.   for(i=0; i<nByte; i++){

  220397.     char c = aIn[i];

  220398.     if( c>='A' && c<='Z' ) c += 32;

  220399.     aOut[i] = c;

  220400.   }

  220401. }

  220402. 

  220403. /*

  220404. ** Tokenize some text using the ascii tokenizer.

  220405. */

  220406. static int fts5AsciiTokenize(

  220407.   Fts5Tokenizer *pTokenizer,

  220408.   void *pCtx,

  220409.   int iUnused,

  220410.   const char *pText, int nText,

  220411.   int (*xToken)(void*, int, const char*, int nToken, int iStart, int iEnd)

  220412. ){

  220413.   AsciiTokenizer *p = (AsciiTokenizer*)pTokenizer;

  220414.   int rc = SQLITE_OK;

  220415.   int ie;

  220416.   int is = 0;

  220417. 

  220418.   char aFold[64];

  220419.   int nFold = sizeof(aFold);

  220420.   char *pFold = aFold;

  220421.   unsigned char *a = p->aTokenChar;

  220422. 

  220423.   UNUSED_PARAM(iUnused);

  220424. 

  220425.   while( is<nText && rc==SQLITE_OK ){

  220426.     int nByte;

  220427. 

  220428.     /* Skip any leading divider characters. */

  220429.     while( is<nText && ((pText[is]&0x80)==0 && a[(int)pText[is]]==0) ){

  220430.       is++;

  220431.     }

  220432.     if( is==nText ) break;

  220433. 

  220434.     /* Count the token characters */

  220435.     ie = is+1;

  220436.     while( ie<nText && ((pText[ie]&0x80) || a[(int)pText[ie]] ) ){

  220437.       ie++;

  220438.     }

  220439. 

  220440.     /* Fold to lower case */

  220441.     nByte = ie-is;

  220442.     if( nByte>nFold ){

  220443.       if( pFold!=aFold ) sqlite3_free(pFold);

  220444.       pFold = sqlite3_malloc64((sqlite3_int64)nByte*2);

  220445.       if( pFold==0 ){

  220446.         rc = SQLITE_NOMEM;

  220447.         break;

  220448.       }

  220449.       nFold = nByte*2;

  220450.     }

  220451.     asciiFold(pFold, &pText[is], nByte);

  220452. 

  220453.     /* Invoke the token callback */

  220454.     rc = xToken(pCtx, 0, pFold, nByte, is, ie);

  220455.     is = ie+1;

  220456.   }

  220457.   

  220458.   if( pFold!=aFold ) sqlite3_free(pFold);

  220459.   if( rc==SQLITE_DONE ) rc = SQLITE_OK;

  220460.   return rc;

  220461. }

  220462. 

  220463. /**************************************************************************

  220464. ** Start of unicode61 tokenizer implementation.

  220465. */

  220466. 

  220467. 

  220468. /*

  220469. ** The following two macros - READ_UTF8 and WRITE_UTF8 - have been copied

  220470. ** from the sqlite3 source file utf.c. If this file is compiled as part

  220471. ** of the amalgamation, they are not required.

  220472. */

  220473. #ifndef SQLITE_AMALGAMATION

  220474. 

  220475. static const unsigned char sqlite3Utf8Trans1[] = {

  220476.   0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07,

  220477.   0x08, 0x09, 0x0a, 0x0b, 0x0c, 0x0d, 0x0e, 0x0f,

  220478.   0x10, 0x11, 0x12, 0x13, 0x14, 0x15, 0x16, 0x17,

  220479.   0x18, 0x19, 0x1a, 0x1b, 0x1c, 0x1d, 0x1e, 0x1f,

  220480.   0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07,

  220481.   0x08, 0x09, 0x0a, 0x0b, 0x0c, 0x0d, 0x0e, 0x0f,

  220482.   0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07,

  220483.   0x00, 0x01, 0x02, 0x03, 0x00, 0x01, 0x00, 0x00,

  220484. };

  220485. 

  220486. #define READ_UTF8(zIn, zTerm, c)                           \

  220487.   c = *(zIn++);                                            \

  220488.   if( c>=0xc0 ){                                           \

  220489.     c = sqlite3Utf8Trans1[c-0xc0];                         \

  220490.     while( zIn!=zTerm && (*zIn & 0xc0)==0x80 ){            \

  220491.       c = (c<<6) + (0x3f & *(zIn++));                      \

  220492.     }                                                      \

  220493.     if( c<0x80                                             \

  220494.         || (c&0xFFFFF800)==0xD800                          \

  220495.         || (c&0xFFFFFFFE)==0xFFFE ){  c = 0xFFFD; }        \

  220496.   }

  220497. 

  220498. 

  220499. #define WRITE_UTF8(zOut, c) {                          \

  220500.   if( c<0x00080 ){                                     \

  220501.     *zOut++ = (unsigned char)(c&0xFF);                 \

  220502.   }                                                    \

  220503.   else if( c<0x00800 ){                                \

  220504.     *zOut++ = 0xC0 + (unsigned char)((c>>6)&0x1F);     \

  220505.     *zOut++ = 0x80 + (unsigned char)(c & 0x3F);        \

  220506.   }                                                    \

  220507.   else if( c<0x10000 ){                                \

  220508.     *zOut++ = 0xE0 + (unsigned char)((c>>12)&0x0F);    \

  220509.     *zOut++ = 0x80 + (unsigned char)((c>>6) & 0x3F);   \

  220510.     *zOut++ = 0x80 + (unsigned char)(c & 0x3F);        \

  220511.   }else{                                               \

  220512.     *zOut++ = 0xF0 + (unsigned char)((c>>18) & 0x07);  \

  220513.     *zOut++ = 0x80 + (unsigned char)((c>>12) & 0x3F);  \

  220514.     *zOut++ = 0x80 + (unsigned char)((c>>6) & 0x3F);   \

  220515.     *zOut++ = 0x80 + (unsigned char)(c & 0x3F);        \

  220516.   }                                                    \

  220517. }

  220518. 

  220519. #endif /* ifndef SQLITE_AMALGAMATION */

  220520. 

  220521. typedef struct Unicode61Tokenizer Unicode61Tokenizer;

  220522. struct Unicode61Tokenizer {

  220523.   unsigned char aTokenChar[128];  /* ASCII range token characters */

  220524.   char *aFold;                    /* Buffer to fold text into */

  220525.   int nFold;                      /* Size of aFold[] in bytes */

  220526.   int eRemoveDiacritic;           /* True if remove_diacritics=1 is set */

  220527.   int nException;

  220528.   int *aiException;

  220529. 

  220530.   unsigned char aCategory[32];    /* True for token char categories */

  220531. };

  220532. 

  220533. /* Values for eRemoveDiacritic (must match internals of fts5_unicode2.c) */

  220534. #define FTS5_REMOVE_DIACRITICS_NONE    0

  220535. #define FTS5_REMOVE_DIACRITICS_SIMPLE  1

  220536. #define FTS5_REMOVE_DIACRITICS_COMPLEX 2

  220537. 

  220538. static int fts5UnicodeAddExceptions(

  220539.   Unicode61Tokenizer *p,          /* Tokenizer object */

  220540.   const char *z,                  /* Characters to treat as exceptions */

  220541.   int bTokenChars                 /* 1 for 'tokenchars', 0 for 'separators' */

  220542. ){

  220543.   int rc = SQLITE_OK;

  220544.   int n = (int)strlen(z);

  220545.   int *aNew;

  220546. 

  220547.   if( n>0 ){

  220548.     aNew = (int*)sqlite3_realloc64(p->aiException,

  220549.                                    (n+p->nException)*sizeof(int));

  220550.     if( aNew ){

  220551.       int nNew = p->nException;

  220552.       const unsigned char *zCsr = (const unsigned char*)z;

  220553.       const unsigned char *zTerm = (const unsigned char*)&z[n];

  220554.       while( zCsr<zTerm ){

  220555.         u32 iCode;

  220556.         int bToken;

  220557.         READ_UTF8(zCsr, zTerm, iCode);

  220558.         if( iCode<128 ){

  220559.           p->aTokenChar[iCode] = (unsigned char)bTokenChars;

  220560.         }else{

  220561.           bToken = p->aCategory[sqlite3Fts5UnicodeCategory(iCode)];

  220562.           assert( (bToken==0 || bToken==1) ); 

  220563.           assert( (bTokenChars==0 || bTokenChars==1) );

  220564.           if( bToken!=bTokenChars && sqlite3Fts5UnicodeIsdiacritic(iCode)==0 ){

  220565.             int i;

  220566.             for(i=0; i<nNew; i++){

  220567.               if( (u32)aNew[i]>iCode ) break;

  220568.             }

  220569.             memmove(&aNew[i+1], &aNew[i], (nNew-i)*sizeof(int));

  220570.             aNew[i] = iCode;

  220571.             nNew++;

  220572.           }

  220573.         }

  220574.       }

  220575.       p->aiException = aNew;

  220576.       p->nException = nNew;

  220577.     }else{

  220578.       rc = SQLITE_NOMEM;

  220579.     }

  220580.   }

  220581. 

  220582.   return rc;

  220583. }

  220584. 

  220585. /*

  220586. ** Return true if the p->aiException[] array contains the value iCode.

  220587. */

  220588. static int fts5UnicodeIsException(Unicode61Tokenizer *p, int iCode){

  220589.   if( p->nException>0 ){

  220590.     int *a = p->aiException;

  220591.     int iLo = 0;

  220592.     int iHi = p->nException-1;

  220593. 

  220594.     while( iHi>=iLo ){

  220595.       int iTest = (iHi + iLo) / 2;

  220596.       if( iCode==a[iTest] ){

  220597.         return 1;

  220598.       }else if( iCode>a[iTest] ){

  220599.         iLo = iTest+1;

  220600.       }else{

  220601.         iHi = iTest-1;

  220602.       }

  220603.     }

  220604.   }

  220605. 

  220606.   return 0;

  220607. }

  220608. 

  220609. /*

  220610. ** Delete a "unicode61" tokenizer.

  220611. */

  220612. static void fts5UnicodeDelete(Fts5Tokenizer *pTok){

  220613.   if( pTok ){

  220614.     Unicode61Tokenizer *p = (Unicode61Tokenizer*)pTok;

  220615.     sqlite3_free(p->aiException);

  220616.     sqlite3_free(p->aFold);

  220617.     sqlite3_free(p);

  220618.   }

  220619.   return;

  220620. }

  220621. 

  220622. static int unicodeSetCategories(Unicode61Tokenizer *p, const char *zCat){

  220623.   const char *z = zCat;

  220624. 

  220625.   while( *z ){

  220626.     while( *z==' ' || *z=='\t' ) z++;

  220627.     if( *z && sqlite3Fts5UnicodeCatParse(z, p->aCategory) ){

  220628.       return SQLITE_ERROR;

  220629.     }

  220630.     while( *z!=' ' && *z!='\t' && *z!='\0' ) z++;

  220631.   }

  220632. 

  220633.   sqlite3Fts5UnicodeAscii(p->aCategory, p->aTokenChar);

  220634.   return SQLITE_OK;

  220635. }

  220636. 

  220637. /*

  220638. ** Create a "unicode61" tokenizer.

  220639. */

  220640. static int fts5UnicodeCreate(

  220641.   void *pUnused, 

  220642.   const char **azArg, int nArg,

  220643.   Fts5Tokenizer **ppOut

  220644. ){

  220645.   int rc = SQLITE_OK;             /* Return code */

  220646.   Unicode61Tokenizer *p = 0;      /* New tokenizer object */ 

  220647. 

  220648.   UNUSED_PARAM(pUnused);

  220649. 

  220650.   if( nArg%2 ){

  220651.     rc = SQLITE_ERROR;

  220652.   }else{

  220653.     p = (Unicode61Tokenizer*)sqlite3_malloc(sizeof(Unicode61Tokenizer));

  220654.     if( p ){

  220655.       const char *zCat = "L* N* Co";

  220656.       int i;

  220657.       memset(p, 0, sizeof(Unicode61Tokenizer));

  220658. 

  220659.       p->eRemoveDiacritic = FTS5_REMOVE_DIACRITICS_SIMPLE;

  220660.       p->nFold = 64;

  220661.       p->aFold = sqlite3_malloc64(p->nFold * sizeof(char));

  220662.       if( p->aFold==0 ){

  220663.         rc = SQLITE_NOMEM;

  220664.       }

  220665. 

  220666.       /* Search for a "categories" argument */

  220667.       for(i=0; rc==SQLITE_OK && i<nArg; i+=2){

  220668.         if( 0==sqlite3_stricmp(azArg[i], "categories") ){

  220669.           zCat = azArg[i+1];

  220670.         }

  220671.       }

  220672. 

  220673.       if( rc==SQLITE_OK ){

  220674.         rc = unicodeSetCategories(p, zCat);

  220675.       }

  220676. 

  220677.       for(i=0; rc==SQLITE_OK && i<nArg; i+=2){

  220678.         const char *zArg = azArg[i+1];

  220679.         if( 0==sqlite3_stricmp(azArg[i], "remove_diacritics") ){

  220680.           if( (zArg[0]!='0' && zArg[0]!='1' && zArg[0]!='2') || zArg[1] ){

  220681.             rc = SQLITE_ERROR;

  220682.           }else{

  220683.             p->eRemoveDiacritic = (zArg[0] - '0');

  220684.             assert( p->eRemoveDiacritic==FTS5_REMOVE_DIACRITICS_NONE

  220685.                  || p->eRemoveDiacritic==FTS5_REMOVE_DIACRITICS_SIMPLE

  220686.                  || p->eRemoveDiacritic==FTS5_REMOVE_DIACRITICS_COMPLEX

  220687.             );

  220688.           }

  220689.         }else

  220690.         if( 0==sqlite3_stricmp(azArg[i], "tokenchars") ){

  220691.           rc = fts5UnicodeAddExceptions(p, zArg, 1);

  220692.         }else

  220693.         if( 0==sqlite3_stricmp(azArg[i], "separators") ){

  220694.           rc = fts5UnicodeAddExceptions(p, zArg, 0);

  220695.         }else

  220696.         if( 0==sqlite3_stricmp(azArg[i], "categories") ){

  220697.           /* no-op */

  220698.         }else{

  220699.           rc = SQLITE_ERROR;

  220700.         }

  220701.       }

  220702. 

  220703.     }else{

  220704.       rc = SQLITE_NOMEM;

  220705.     }

  220706.     if( rc!=SQLITE_OK ){

  220707.       fts5UnicodeDelete((Fts5Tokenizer*)p);

  220708.       p = 0;

  220709.     }

  220710.     *ppOut = (Fts5Tokenizer*)p;

  220711.   }

  220712.   return rc;

  220713. }

  220714. 

  220715. /*

  220716. ** Return true if, for the purposes of tokenizing with the tokenizer

  220717. ** passed as the first argument, codepoint iCode is considered a token 

  220718. ** character (not a separator).

  220719. */

  220720. static int fts5UnicodeIsAlnum(Unicode61Tokenizer *p, int iCode){

  220721.   return (

  220722.     p->aCategory[sqlite3Fts5UnicodeCategory((u32)iCode)]

  220723.     ^ fts5UnicodeIsException(p, iCode)

  220724.   );

  220725. }

  220726. 

  220727. static int fts5UnicodeTokenize(

  220728.   Fts5Tokenizer *pTokenizer,

  220729.   void *pCtx,

  220730.   int iUnused,

  220731.   const char *pText, int nText,

  220732.   int (*xToken)(void*, int, const char*, int nToken, int iStart, int iEnd)

  220733. ){

  220734.   Unicode61Tokenizer *p = (Unicode61Tokenizer*)pTokenizer;

  220735.   int rc = SQLITE_OK;

  220736.   unsigned char *a = p->aTokenChar;

  220737. 

  220738.   unsigned char *zTerm = (unsigned char*)&pText[nText];

  220739.   unsigned char *zCsr = (unsigned char *)pText;

  220740. 

  220741.   /* Output buffer */

  220742.   char *aFold = p->aFold;

  220743.   int nFold = p->nFold;

  220744.   const char *pEnd = &aFold[nFold-6];

  220745. 

  220746.   UNUSED_PARAM(iUnused);

  220747. 

  220748.   /* Each iteration of this loop gobbles up a contiguous run of separators,

  220749.   ** then the next token.  */

  220750.   while( rc==SQLITE_OK ){

  220751.     u32 iCode;                    /* non-ASCII codepoint read from input */

  220752.     char *zOut = aFold;

  220753.     int is;

  220754.     int ie;

  220755. 

  220756.     /* Skip any separator characters. */

  220757.     while( 1 ){

  220758.       if( zCsr>=zTerm ) goto tokenize_done;

  220759.       if( *zCsr & 0x80 ) {

  220760.         /* A character outside of the ascii range. Skip past it if it is

  220761.         ** a separator character. Or break out of the loop if it is not. */

  220762.         is = zCsr - (unsigned char*)pText;

  220763.         READ_UTF8(zCsr, zTerm, iCode);

  220764.         if( fts5UnicodeIsAlnum(p, iCode) ){

  220765.           goto non_ascii_tokenchar;

  220766.         }

  220767.       }else{

  220768.         if( a[*zCsr] ){

  220769.           is = zCsr - (unsigned char*)pText;

  220770.           goto ascii_tokenchar;

  220771.         }

  220772.         zCsr++;

  220773.       }

  220774.     }

  220775. 

  220776.     /* Run through the tokenchars. Fold them into the output buffer along

  220777.     ** the way.  */

  220778.     while( zCsr<zTerm ){

  220779. 

  220780.       /* Grow the output buffer so that there is sufficient space to fit the

  220781.       ** largest possible utf-8 character.  */

  220782.       if( zOut>pEnd ){

  220783.         aFold = sqlite3_malloc64((sqlite3_int64)nFold*2);

  220784.         if( aFold==0 ){

  220785.           rc = SQLITE_NOMEM;

  220786.           goto tokenize_done;

  220787.         }

  220788.         zOut = &aFold[zOut - p->aFold];

  220789.         memcpy(aFold, p->aFold, nFold);

  220790.         sqlite3_free(p->aFold);

  220791.         p->aFold = aFold;

  220792.         p->nFold = nFold = nFold*2;

  220793.         pEnd = &aFold[nFold-6];

  220794.       }

  220795. 

  220796.       if( *zCsr & 0x80 ){

  220797.         /* An non-ascii-range character. Fold it into the output buffer if

  220798.         ** it is a token character, or break out of the loop if it is not. */

  220799.         READ_UTF8(zCsr, zTerm, iCode);

  220800.         if( fts5UnicodeIsAlnum(p,iCode)||sqlite3Fts5UnicodeIsdiacritic(iCode) ){

  220801.  non_ascii_tokenchar:

  220802.           iCode = sqlite3Fts5UnicodeFold(iCode, p->eRemoveDiacritic);

  220803.           if( iCode ) WRITE_UTF8(zOut, iCode);

  220804.         }else{

  220805.           break;

  220806.         }

  220807.       }else if( a[*zCsr]==0 ){

  220808.         /* An ascii-range separator character. End of token. */

  220809.         break; 

  220810.       }else{

  220811.  ascii_tokenchar:

  220812.         if( *zCsr>='A' && *zCsr<='Z' ){

  220813.           *zOut++ = *zCsr + 32;

  220814.         }else{

  220815.           *zOut++ = *zCsr;

  220816.         }

  220817.         zCsr++;

  220818.       }

  220819.       ie = zCsr - (unsigned char*)pText;

  220820.     }

  220821. 

  220822.     /* Invoke the token callback */

  220823.     rc = xToken(pCtx, 0, aFold, zOut-aFold, is, ie); 

  220824.   }

  220825.   

  220826.  tokenize_done:

  220827.   if( rc==SQLITE_DONE ) rc = SQLITE_OK;

  220828.   return rc;

  220829. }

  220830. 

  220831. /**************************************************************************

  220832. ** Start of porter stemmer implementation.

  220833. */

  220834. 

  220835. /* Any tokens larger than this (in bytes) are passed through without

  220836. ** stemming. */

  220837. #define FTS5_PORTER_MAX_TOKEN 64

  220838. 

  220839. typedef struct PorterTokenizer PorterTokenizer;

  220840. struct PorterTokenizer {

  220841.   fts5_tokenizer tokenizer;       /* Parent tokenizer module */

  220842.   Fts5Tokenizer *pTokenizer;      /* Parent tokenizer instance */

  220843.   char aBuf[FTS5_PORTER_MAX_TOKEN + 64];

  220844. };

  220845. 

  220846. /*

  220847. ** Delete a "porter" tokenizer.

  220848. */

  220849. static void fts5PorterDelete(Fts5Tokenizer *pTok){

  220850.   if( pTok ){

  220851.     PorterTokenizer *p = (PorterTokenizer*)pTok;

  220852.     if( p->pTokenizer ){

  220853.       p->tokenizer.xDelete(p->pTokenizer);

  220854.     }

  220855.     sqlite3_free(p);

  220856.   }

  220857. }

  220858. 

  220859. /*

  220860. ** Create a "porter" tokenizer.

  220861. */

  220862. static int fts5PorterCreate(

  220863.   void *pCtx, 

  220864.   const char **azArg, int nArg,

  220865.   Fts5Tokenizer **ppOut

  220866. ){

  220867.   fts5_api *pApi = (fts5_api*)pCtx;

  220868.   int rc = SQLITE_OK;

  220869.   PorterTokenizer *pRet;

  220870.   void *pUserdata = 0;

  220871.   const char *zBase = "unicode61";

  220872. 

  220873.   if( nArg>0 ){

  220874.     zBase = azArg[0];

  220875.   }

  220876. 

  220877.   pRet = (PorterTokenizer*)sqlite3_malloc(sizeof(PorterTokenizer));

  220878.   if( pRet ){

  220879.     memset(pRet, 0, sizeof(PorterTokenizer));

  220880.     rc = pApi->xFindTokenizer(pApi, zBase, &pUserdata, &pRet->tokenizer);

  220881.   }else{

  220882.     rc = SQLITE_NOMEM;

  220883.   }

  220884.   if( rc==SQLITE_OK ){

  220885.     int nArg2 = (nArg>0 ? nArg-1 : 0);

  220886.     const char **azArg2 = (nArg2 ? &azArg[1] : 0);

  220887.     rc = pRet->tokenizer.xCreate(pUserdata, azArg2, nArg2, &pRet->pTokenizer);

  220888.   }

  220889. 

  220890.   if( rc!=SQLITE_OK ){

  220891.     fts5PorterDelete((Fts5Tokenizer*)pRet);

  220892.     pRet = 0;

  220893.   }

  220894.   *ppOut = (Fts5Tokenizer*)pRet;

  220895.   return rc;

  220896. }

  220897. 

  220898. typedef struct PorterContext PorterContext;

  220899. struct PorterContext {

  220900.   void *pCtx;

  220901.   int (*xToken)(void*, int, const char*, int, int, int);

  220902.   char *aBuf;

  220903. };

  220904. 

  220905. typedef struct PorterRule PorterRule;

  220906. struct PorterRule {

  220907.   const char *zSuffix;

  220908.   int nSuffix;

  220909.   int (*xCond)(char *zStem, int nStem);

  220910.   const char *zOutput;

  220911.   int nOutput;

  220912. };

  220913. 

  220914. #if 0

  220915. static int fts5PorterApply(char *aBuf, int *pnBuf, PorterRule *aRule){

  220916.   int ret = -1;

  220917.   int nBuf = *pnBuf;

  220918.   PorterRule *p;

  220919. 

  220920.   for(p=aRule; p->zSuffix; p++){

  220921.     assert( strlen(p->zSuffix)==p->nSuffix );

  220922.     assert( strlen(p->zOutput)==p->nOutput );

  220923.     if( nBuf<p->nSuffix ) continue;

  220924.     if( 0==memcmp(&aBuf[nBuf - p->nSuffix], p->zSuffix, p->nSuffix) ) break;

  220925.   }

  220926. 

  220927.   if( p->zSuffix ){

  220928.     int nStem = nBuf - p->nSuffix;

  220929.     if( p->xCond==0 || p->xCond(aBuf, nStem) ){

  220930.       memcpy(&aBuf[nStem], p->zOutput, p->nOutput);

  220931.       *pnBuf = nStem + p->nOutput;

  220932.       ret = p - aRule;

  220933.     }

  220934.   }

  220935. 

  220936.   return ret;

  220937. }

  220938. #endif

  220939. 

  220940. static int fts5PorterIsVowel(char c, int bYIsVowel){

  220941.   return (

  220942.       c=='a' || c=='e' || c=='i' || c=='o' || c=='u' || (bYIsVowel && c=='y')

  220943.   );

  220944. }

  220945. 

  220946. static int fts5PorterGobbleVC(char *zStem, int nStem, int bPrevCons){

  220947.   int i;

  220948.   int bCons = bPrevCons;

  220949. 

  220950.   /* Scan for a vowel */

  220951.   for(i=0; i<nStem; i++){

  220952.     if( 0==(bCons = !fts5PorterIsVowel(zStem[i], bCons)) ) break;

  220953.   }

  220954. 

  220955.   /* Scan for a consonent */

  220956.   for(i++; i<nStem; i++){

  220957.     if( (bCons = !fts5PorterIsVowel(zStem[i], bCons)) ) return i+1;

  220958.   }

  220959.   return 0;

  220960. }

  220961. 

  220962. /* porter rule condition: (m > 0) */

  220963. static int fts5Porter_MGt0(char *zStem, int nStem){

  220964.   return !!fts5PorterGobbleVC(zStem, nStem, 0);

  220965. }

  220966. 

  220967. /* porter rule condition: (m > 1) */

  220968. static int fts5Porter_MGt1(char *zStem, int nStem){

  220969.   int n;

  220970.   n = fts5PorterGobbleVC(zStem, nStem, 0);

  220971.   if( n && fts5PorterGobbleVC(&zStem[n], nStem-n, 1) ){

  220972.     return 1;

  220973.   }

  220974.   return 0;

  220975. }

  220976. 

  220977. /* porter rule condition: (m = 1) */

  220978. static int fts5Porter_MEq1(char *zStem, int nStem){

  220979.   int n;

  220980.   n = fts5PorterGobbleVC(zStem, nStem, 0);

  220981.   if( n && 0==fts5PorterGobbleVC(&zStem[n], nStem-n, 1) ){

  220982.     return 1;

  220983.   }

  220984.   return 0;

  220985. }

  220986. 

  220987. /* porter rule condition: (*o) */

  220988. static int fts5Porter_Ostar(char *zStem, int nStem){

  220989.   if( zStem[nStem-1]=='w' || zStem[nStem-1]=='x' || zStem[nStem-1]=='y' ){

  220990.     return 0;

  220991.   }else{

  220992.     int i;

  220993.     int mask = 0;

  220994.     int bCons = 0;

  220995.     for(i=0; i<nStem; i++){

  220996.       bCons = !fts5PorterIsVowel(zStem[i], bCons);

  220997.       assert( bCons==0 || bCons==1 );

  220998.       mask = (mask << 1) + bCons;

  220999.     }

  221000.     return ((mask & 0x0007)==0x0005);

  221001.   }

  221002. }

  221003. 

  221004. /* porter rule condition: (m > 1 and (*S or *T)) */

  221005. static int fts5Porter_MGt1_and_S_or_T(char *zStem, int nStem){

  221006.   assert( nStem>0 );

  221007.   return (zStem[nStem-1]=='s' || zStem[nStem-1]=='t') 

  221008.       && fts5Porter_MGt1(zStem, nStem);

  221009. }

  221010. 

  221011. /* porter rule condition: (*v*) */

  221012. static int fts5Porter_Vowel(char *zStem, int nStem){

  221013.   int i;

  221014.   for(i=0; i<nStem; i++){

  221015.     if( fts5PorterIsVowel(zStem[i], i>0) ){

  221016.       return 1;

  221017.     }

  221018.   }

  221019.   return 0;

  221020. }

  221021. 

  221022. 

  221023. /**************************************************************************

  221024. ***************************************************************************

  221025. ** GENERATED CODE STARTS HERE (mkportersteps.tcl)

  221026. */

  221027. 

  221028. static int fts5PorterStep4(char *aBuf, int *pnBuf){

  221029.   int ret = 0;

  221030.   int nBuf = *pnBuf;

  221031.   switch( aBuf[nBuf-2] ){

  221032.     

  221033.     case 'a': 

  221034.       if( nBuf>2 && 0==memcmp("al", &aBuf[nBuf-2], 2) ){

  221035.         if( fts5Porter_MGt1(aBuf, nBuf-2) ){

  221036.           *pnBuf = nBuf - 2;

  221037.         }

  221038.       }

  221039.       break;

  221040.   

  221041.     case 'c': 

  221042.       if( nBuf>4 && 0==memcmp("ance", &aBuf[nBuf-4], 4) ){

  221043.         if( fts5Porter_MGt1(aBuf, nBuf-4) ){

  221044.           *pnBuf = nBuf - 4;

  221045.         }

  221046.       }else if( nBuf>4 && 0==memcmp("ence", &aBuf[nBuf-4], 4) ){

  221047.         if( fts5Porter_MGt1(aBuf, nBuf-4) ){

  221048.           *pnBuf = nBuf - 4;

  221049.         }

  221050.       }

  221051.       break;

  221052.   

  221053.     case 'e': 

  221054.       if( nBuf>2 && 0==memcmp("er", &aBuf[nBuf-2], 2) ){

  221055.         if( fts5Porter_MGt1(aBuf, nBuf-2) ){

  221056.           *pnBuf = nBuf - 2;

  221057.         }

  221058.       }

  221059.       break;

  221060.   

  221061.     case 'i': 

  221062.       if( nBuf>2 && 0==memcmp("ic", &aBuf[nBuf-2], 2) ){

  221063.         if( fts5Porter_MGt1(aBuf, nBuf-2) ){

  221064.           *pnBuf = nBuf - 2;

  221065.         }

  221066.       }

  221067.       break;

  221068.   

  221069.     case 'l': 

  221070.       if( nBuf>4 && 0==memcmp("able", &aBuf[nBuf-4], 4) ){

  221071.         if( fts5Porter_MGt1(aBuf, nBuf-4) ){

  221072.           *pnBuf = nBuf - 4;

  221073.         }

  221074.       }else if( nBuf>4 && 0==memcmp("ible", &aBuf[nBuf-4], 4) ){

  221075.         if( fts5Porter_MGt1(aBuf, nBuf-4) ){

  221076.           *pnBuf = nBuf - 4;

  221077.         }

  221078.       }

  221079.       break;

  221080.   

  221081.     case 'n': 

  221082.       if( nBuf>3 && 0==memcmp("ant", &aBuf[nBuf-3], 3) ){

  221083.         if( fts5Porter_MGt1(aBuf, nBuf-3) ){

  221084.           *pnBuf = nBuf - 3;

  221085.         }

  221086.       }else if( nBuf>5 && 0==memcmp("ement", &aBuf[nBuf-5], 5) ){

  221087.         if( fts5Porter_MGt1(aBuf, nBuf-5) ){

  221088.           *pnBuf = nBuf - 5;

  221089.         }

  221090.       }else if( nBuf>4 && 0==memcmp("ment", &aBuf[nBuf-4], 4) ){

  221091.         if( fts5Porter_MGt1(aBuf, nBuf-4) ){

  221092.           *pnBuf = nBuf - 4;

  221093.         }

  221094.       }else if( nBuf>3 && 0==memcmp("ent", &aBuf[nBuf-3], 3) ){

  221095.         if( fts5Porter_MGt1(aBuf, nBuf-3) ){

  221096.           *pnBuf = nBuf - 3;

  221097.         }

  221098.       }

  221099.       break;

  221100.   

  221101.     case 'o': 

  221102.       if( nBuf>3 && 0==memcmp("ion", &aBuf[nBuf-3], 3) ){

  221103.         if( fts5Porter_MGt1_and_S_or_T(aBuf, nBuf-3) ){

  221104.           *pnBuf = nBuf - 3;

  221105.         }

  221106.       }else if( nBuf>2 && 0==memcmp("ou", &aBuf[nBuf-2], 2) ){

  221107.         if( fts5Porter_MGt1(aBuf, nBuf-2) ){

  221108.           *pnBuf = nBuf - 2;

  221109.         }

  221110.       }

  221111.       break;

  221112.   

  221113.     case 's': 

  221114.       if( nBuf>3 && 0==memcmp("ism", &aBuf[nBuf-3], 3) ){

  221115.         if( fts5Porter_MGt1(aBuf, nBuf-3) ){

  221116.           *pnBuf = nBuf - 3;

  221117.         }

  221118.       }

  221119.       break;

  221120.   

  221121.     case 't': 

  221122.       if( nBuf>3 && 0==memcmp("ate", &aBuf[nBuf-3], 3) ){

  221123.         if( fts5Porter_MGt1(aBuf, nBuf-3) ){

  221124.           *pnBuf = nBuf - 3;

  221125.         }

  221126.       }else if( nBuf>3 && 0==memcmp("iti", &aBuf[nBuf-3], 3) ){

  221127.         if( fts5Porter_MGt1(aBuf, nBuf-3) ){

  221128.           *pnBuf = nBuf - 3;

  221129.         }

  221130.       }

  221131.       break;

  221132.   

  221133.     case 'u': 

  221134.       if( nBuf>3 && 0==memcmp("ous", &aBuf[nBuf-3], 3) ){

  221135.         if( fts5Porter_MGt1(aBuf, nBuf-3) ){

  221136.           *pnBuf = nBuf - 3;

  221137.         }

  221138.       }

  221139.       break;

  221140.   

  221141.     case 'v': 

  221142.       if( nBuf>3 && 0==memcmp("ive", &aBuf[nBuf-3], 3) ){

  221143.         if( fts5Porter_MGt1(aBuf, nBuf-3) ){

  221144.           *pnBuf = nBuf - 3;

  221145.         }

  221146.       }

  221147.       break;

  221148.   

  221149.     case 'z': 

  221150.       if( nBuf>3 && 0==memcmp("ize", &aBuf[nBuf-3], 3) ){

  221151.         if( fts5Porter_MGt1(aBuf, nBuf-3) ){

  221152.           *pnBuf = nBuf - 3;

  221153.         }

  221154.       }

  221155.       break;

  221156.   

  221157.   }

  221158.   return ret;

  221159. }

  221160.   

  221161. 

  221162. static int fts5PorterStep1B2(char *aBuf, int *pnBuf){

  221163.   int ret = 0;

  221164.   int nBuf = *pnBuf;

  221165.   switch( aBuf[nBuf-2] ){

  221166.     

  221167.     case 'a': 

  221168.       if( nBuf>2 && 0==memcmp("at", &aBuf[nBuf-2], 2) ){

  221169.         memcpy(&aBuf[nBuf-2], "ate", 3);

  221170.         *pnBuf = nBuf - 2 + 3;

  221171.         ret = 1;

  221172.       }

  221173.       break;

  221174.   

  221175.     case 'b': 

  221176.       if( nBuf>2 && 0==memcmp("bl", &aBuf[nBuf-2], 2) ){

  221177.         memcpy(&aBuf[nBuf-2], "ble", 3);

  221178.         *pnBuf = nBuf - 2 + 3;

  221179.         ret = 1;

  221180.       }

  221181.       break;

  221182.   

  221183.     case 'i': 

  221184.       if( nBuf>2 && 0==memcmp("iz", &aBuf[nBuf-2], 2) ){

  221185.         memcpy(&aBuf[nBuf-2], "ize", 3);

  221186.         *pnBuf = nBuf - 2 + 3;

  221187.         ret = 1;

  221188.       }

  221189.       break;

  221190.   

  221191.   }

  221192.   return ret;

  221193. }

  221194.   

  221195. 

  221196. static int fts5PorterStep2(char *aBuf, int *pnBuf){

  221197.   int ret = 0;

  221198.   int nBuf = *pnBuf;

  221199.   switch( aBuf[nBuf-2] ){

  221200.     

  221201.     case 'a': 

  221202.       if( nBuf>7 && 0==memcmp("ational", &aBuf[nBuf-7], 7) ){

  221203.         if( fts5Porter_MGt0(aBuf, nBuf-7) ){

  221204.           memcpy(&aBuf[nBuf-7], "ate", 3);

  221205.           *pnBuf = nBuf - 7 + 3;

  221206.         }

  221207.       }else if( nBuf>6 && 0==memcmp("tional", &aBuf[nBuf-6], 6) ){

  221208.         if( fts5Porter_MGt0(aBuf, nBuf-6) ){

  221209.           memcpy(&aBuf[nBuf-6], "tion", 4);

  221210.           *pnBuf = nBuf - 6 + 4;

  221211.         }

  221212.       }

  221213.       break;

  221214.   

  221215.     case 'c': 

  221216.       if( nBuf>4 && 0==memcmp("enci", &aBuf[nBuf-4], 4) ){

  221217.         if( fts5Porter_MGt0(aBuf, nBuf-4) ){

  221218.           memcpy(&aBuf[nBuf-4], "ence", 4);

  221219.           *pnBuf = nBuf - 4 + 4;

  221220.         }

  221221.       }else if( nBuf>4 && 0==memcmp("anci", &aBuf[nBuf-4], 4) ){

  221222.         if( fts5Porter_MGt0(aBuf, nBuf-4) ){

  221223.           memcpy(&aBuf[nBuf-4], "ance", 4);

  221224.           *pnBuf = nBuf - 4 + 4;

  221225.         }

  221226.       }

  221227.       break;

  221228.   

  221229.     case 'e': 

  221230.       if( nBuf>4 && 0==memcmp("izer", &aBuf[nBuf-4], 4) ){

  221231.         if( fts5Porter_MGt0(aBuf, nBuf-4) ){

  221232.           memcpy(&aBuf[nBuf-4], "ize", 3);

  221233.           *pnBuf = nBuf - 4 + 3;

  221234.         }

  221235.       }

  221236.       break;

  221237.   

  221238.     case 'g': 

  221239.       if( nBuf>4 && 0==memcmp("logi", &aBuf[nBuf-4], 4) ){

  221240.         if( fts5Porter_MGt0(aBuf, nBuf-4) ){

  221241.           memcpy(&aBuf[nBuf-4], "log", 3);

  221242.           *pnBuf = nBuf - 4 + 3;

  221243.         }

  221244.       }

  221245.       break;

  221246.   

  221247.     case 'l': 

  221248.       if( nBuf>3 && 0==memcmp("bli", &aBuf[nBuf-3], 3) ){

  221249.         if( fts5Porter_MGt0(aBuf, nBuf-3) ){

  221250.           memcpy(&aBuf[nBuf-3], "ble", 3);

  221251.           *pnBuf = nBuf - 3 + 3;

  221252.         }

  221253.       }else if( nBuf>4 && 0==memcmp("alli", &aBuf[nBuf-4], 4) ){

  221254.         if( fts5Porter_MGt0(aBuf, nBuf-4) ){

  221255.           memcpy(&aBuf[nBuf-4], "al", 2);

  221256.           *pnBuf = nBuf - 4 + 2;

  221257.         }

  221258.       }else if( nBuf>5 && 0==memcmp("entli", &aBuf[nBuf-5], 5) ){

  221259.         if( fts5Porter_MGt0(aBuf, nBuf-5) ){

  221260.           memcpy(&aBuf[nBuf-5], "ent", 3);

  221261.           *pnBuf = nBuf - 5 + 3;

  221262.         }

  221263.       }else if( nBuf>3 && 0==memcmp("eli", &aBuf[nBuf-3], 3) ){

  221264.         if( fts5Porter_MGt0(aBuf, nBuf-3) ){

  221265.           memcpy(&aBuf[nBuf-3], "e", 1);

  221266.           *pnBuf = nBuf - 3 + 1;

  221267.         }

  221268.       }else if( nBuf>5 && 0==memcmp("ousli", &aBuf[nBuf-5], 5) ){

  221269.         if( fts5Porter_MGt0(aBuf, nBuf-5) ){

  221270.           memcpy(&aBuf[nBuf-5], "ous", 3);

  221271.           *pnBuf = nBuf - 5 + 3;

  221272.         }

  221273.       }

  221274.       break;

  221275.   

  221276.     case 'o': 

  221277.       if( nBuf>7 && 0==memcmp("ization", &aBuf[nBuf-7], 7) ){

  221278.         if( fts5Porter_MGt0(aBuf, nBuf-7) ){

  221279.           memcpy(&aBuf[nBuf-7], "ize", 3);

  221280.           *pnBuf = nBuf - 7 + 3;

  221281.         }

  221282.       }else if( nBuf>5 && 0==memcmp("ation", &aBuf[nBuf-5], 5) ){

  221283.         if( fts5Porter_MGt0(aBuf, nBuf-5) ){

  221284.           memcpy(&aBuf[nBuf-5], "ate", 3);

  221285.           *pnBuf = nBuf - 5 + 3;

  221286.         }

  221287.       }else if( nBuf>4 && 0==memcmp("ator", &aBuf[nBuf-4], 4) ){

  221288.         if( fts5Porter_MGt0(aBuf, nBuf-4) ){

  221289.           memcpy(&aBuf[nBuf-4], "ate", 3);

  221290.           *pnBuf = nBuf - 4 + 3;

  221291.         }

  221292.       }

  221293.       break;

  221294.   

  221295.     case 's': 

  221296.       if( nBuf>5 && 0==memcmp("alism", &aBuf[nBuf-5], 5) ){

  221297.         if( fts5Porter_MGt0(aBuf, nBuf-5) ){

  221298.           memcpy(&aBuf[nBuf-5], "al", 2);

  221299.           *pnBuf = nBuf - 5 + 2;

  221300.         }

  221301.       }else if( nBuf>7 && 0==memcmp("iveness", &aBuf[nBuf-7], 7) ){

  221302.         if( fts5Porter_MGt0(aBuf, nBuf-7) ){

  221303.           memcpy(&aBuf[nBuf-7], "ive", 3);

  221304.           *pnBuf = nBuf - 7 + 3;

  221305.         }

  221306.       }else if( nBuf>7 && 0==memcmp("fulness", &aBuf[nBuf-7], 7) ){

  221307.         if( fts5Porter_MGt0(aBuf, nBuf-7) ){

  221308.           memcpy(&aBuf[nBuf-7], "ful", 3);

  221309.           *pnBuf = nBuf - 7 + 3;

  221310.         }

  221311.       }else if( nBuf>7 && 0==memcmp("ousness", &aBuf[nBuf-7], 7) ){

  221312.         if( fts5Porter_MGt0(aBuf, nBuf-7) ){

  221313.           memcpy(&aBuf[nBuf-7], "ous", 3);

  221314.           *pnBuf = nBuf - 7 + 3;

  221315.         }

  221316.       }

  221317.       break;

  221318.   

  221319.     case 't': 

  221320.       if( nBuf>5 && 0==memcmp("aliti", &aBuf[nBuf-5], 5) ){

  221321.         if( fts5Porter_MGt0(aBuf, nBuf-5) ){

  221322.           memcpy(&aBuf[nBuf-5], "al", 2);

  221323.           *pnBuf = nBuf - 5 + 2;

  221324.         }

  221325.       }else if( nBuf>5 && 0==memcmp("iviti", &aBuf[nBuf-5], 5) ){

  221326.         if( fts5Porter_MGt0(aBuf, nBuf-5) ){

  221327.           memcpy(&aBuf[nBuf-5], "ive", 3);

  221328.           *pnBuf = nBuf - 5 + 3;

  221329.         }

  221330.       }else if( nBuf>6 && 0==memcmp("biliti", &aBuf[nBuf-6], 6) ){

  221331.         if( fts5Porter_MGt0(aBuf, nBuf-6) ){

  221332.           memcpy(&aBuf[nBuf-6], "ble", 3);

  221333.           *pnBuf = nBuf - 6 + 3;

  221334.         }

  221335.       }

  221336.       break;

  221337.   

  221338.   }

  221339.   return ret;

  221340. }

  221341.   

  221342. 

  221343. static int fts5PorterStep3(char *aBuf, int *pnBuf){

  221344.   int ret = 0;

  221345.   int nBuf = *pnBuf;

  221346.   switch( aBuf[nBuf-2] ){

  221347.     

  221348.     case 'a': 

  221349.       if( nBuf>4 && 0==memcmp("ical", &aBuf[nBuf-4], 4) ){

  221350.         if( fts5Porter_MGt0(aBuf, nBuf-4) ){

  221351.           memcpy(&aBuf[nBuf-4], "ic", 2);

  221352.           *pnBuf = nBuf - 4 + 2;

  221353.         }

  221354.       }

  221355.       break;

  221356.   

  221357.     case 's': 

  221358.       if( nBuf>4 && 0==memcmp("ness", &aBuf[nBuf-4], 4) ){

  221359.         if( fts5Porter_MGt0(aBuf, nBuf-4) ){

  221360.           *pnBuf = nBuf - 4;

  221361.         }

  221362.       }

  221363.       break;

  221364.   

  221365.     case 't': 

  221366.       if( nBuf>5 && 0==memcmp("icate", &aBuf[nBuf-5], 5) ){

  221367.         if( fts5Porter_MGt0(aBuf, nBuf-5) ){

  221368.           memcpy(&aBuf[nBuf-5], "ic", 2);

  221369.           *pnBuf = nBuf - 5 + 2;

  221370.         }

  221371.       }else if( nBuf>5 && 0==memcmp("iciti", &aBuf[nBuf-5], 5) ){

  221372.         if( fts5Porter_MGt0(aBuf, nBuf-5) ){

  221373.           memcpy(&aBuf[nBuf-5], "ic", 2);

  221374.           *pnBuf = nBuf - 5 + 2;

  221375.         }

  221376.       }

  221377.       break;

  221378.   

  221379.     case 'u': 

  221380.       if( nBuf>3 && 0==memcmp("ful", &aBuf[nBuf-3], 3) ){

  221381.         if( fts5Porter_MGt0(aBuf, nBuf-3) ){

  221382.           *pnBuf = nBuf - 3;

  221383.         }

  221384.       }

  221385.       break;

  221386.   

  221387.     case 'v': 

  221388.       if( nBuf>5 && 0==memcmp("ative", &aBuf[nBuf-5], 5) ){

  221389.         if( fts5Porter_MGt0(aBuf, nBuf-5) ){

  221390.           *pnBuf = nBuf - 5;

  221391.         }

  221392.       }

  221393.       break;

  221394.   

  221395.     case 'z': 

  221396.       if( nBuf>5 && 0==memcmp("alize", &aBuf[nBuf-5], 5) ){

  221397.         if( fts5Porter_MGt0(aBuf, nBuf-5) ){

  221398.           memcpy(&aBuf[nBuf-5], "al", 2);

  221399.           *pnBuf = nBuf - 5 + 2;

  221400.         }

  221401.       }

  221402.       break;

  221403.   

  221404.   }

  221405.   return ret;

  221406. }

  221407.   

  221408. 

  221409. static int fts5PorterStep1B(char *aBuf, int *pnBuf){

  221410.   int ret = 0;

  221411.   int nBuf = *pnBuf;

  221412.   switch( aBuf[nBuf-2] ){

  221413.     

  221414.     case 'e': 

  221415.       if( nBuf>3 && 0==memcmp("eed", &aBuf[nBuf-3], 3) ){

  221416.         if( fts5Porter_MGt0(aBuf, nBuf-3) ){

  221417.           memcpy(&aBuf[nBuf-3], "ee", 2);

  221418.           *pnBuf = nBuf - 3 + 2;

  221419.         }

  221420.       }else if( nBuf>2 && 0==memcmp("ed", &aBuf[nBuf-2], 2) ){

  221421.         if( fts5Porter_Vowel(aBuf, nBuf-2) ){

  221422.           *pnBuf = nBuf - 2;

  221423.           ret = 1;

  221424.         }

  221425.       }

  221426.       break;

  221427.   

  221428.     case 'n': 

  221429.       if( nBuf>3 && 0==memcmp("ing", &aBuf[nBuf-3], 3) ){

  221430.         if( fts5Porter_Vowel(aBuf, nBuf-3) ){

  221431.           *pnBuf = nBuf - 3;

  221432.           ret = 1;

  221433.         }

  221434.       }

  221435.       break;

  221436.   

  221437.   }

  221438.   return ret;

  221439. }

  221440.   

  221441. /* 

  221442. ** GENERATED CODE ENDS HERE (mkportersteps.tcl)

  221443. ***************************************************************************

  221444. **************************************************************************/

  221445. 

  221446. static void fts5PorterStep1A(char *aBuf, int *pnBuf){

  221447.   int nBuf = *pnBuf;

  221448.   if( aBuf[nBuf-1]=='s' ){

  221449.     if( aBuf[nBuf-2]=='e' ){

  221450.       if( (nBuf>4 && aBuf[nBuf-4]=='s' && aBuf[nBuf-3]=='s') 

  221451.        || (nBuf>3 && aBuf[nBuf-3]=='i' )

  221452.       ){

  221453.         *pnBuf = nBuf-2;

  221454.       }else{

  221455.         *pnBuf = nBuf-1;

  221456.       }

  221457.     }

  221458.     else if( aBuf[nBuf-2]!='s' ){

  221459.       *pnBuf = nBuf-1;

  221460.     }

  221461.   }

  221462. }

  221463. 

  221464. static int fts5PorterCb(

  221465.   void *pCtx, 

  221466.   int tflags,

  221467.   const char *pToken, 

  221468.   int nToken, 

  221469.   int iStart, 

  221470.   int iEnd

  221471. ){

  221472.   PorterContext *p = (PorterContext*)pCtx;

  221473. 

  221474.   char *aBuf;

  221475.   int nBuf;

  221476. 

  221477.   if( nToken>FTS5_PORTER_MAX_TOKEN || nToken<3 ) goto pass_through;

  221478.   aBuf = p->aBuf;

  221479.   nBuf = nToken;

  221480.   memcpy(aBuf, pToken, nBuf);

  221481. 

  221482.   /* Step 1. */

  221483.   fts5PorterStep1A(aBuf, &nBuf);

  221484.   if( fts5PorterStep1B(aBuf, &nBuf) ){

  221485.     if( fts5PorterStep1B2(aBuf, &nBuf)==0 ){

  221486.       char c = aBuf[nBuf-1];

  221487.       if( fts5PorterIsVowel(c, 0)==0 

  221488.        && c!='l' && c!='s' && c!='z' && c==aBuf[nBuf-2] 

  221489.       ){

  221490.         nBuf--;

  221491.       }else if( fts5Porter_MEq1(aBuf, nBuf) && fts5Porter_Ostar(aBuf, nBuf) ){

  221492.         aBuf[nBuf++] = 'e';

  221493.       }

  221494.     }

  221495.   }

  221496. 

  221497.   /* Step 1C. */

  221498.   if( aBuf[nBuf-1]=='y' && fts5Porter_Vowel(aBuf, nBuf-1) ){

  221499.     aBuf[nBuf-1] = 'i';

  221500.   }

  221501. 

  221502.   /* Steps 2 through 4. */

  221503.   fts5PorterStep2(aBuf, &nBuf);

  221504.   fts5PorterStep3(aBuf, &nBuf);

  221505.   fts5PorterStep4(aBuf, &nBuf);

  221506. 

  221507.   /* Step 5a. */

  221508.   assert( nBuf>0 );

  221509.   if( aBuf[nBuf-1]=='e' ){

  221510.     if( fts5Porter_MGt1(aBuf, nBuf-1) 

  221511.      || (fts5Porter_MEq1(aBuf, nBuf-1) && !fts5Porter_Ostar(aBuf, nBuf-1))

  221512.     ){

  221513.       nBuf--;

  221514.     }

  221515.   }

  221516. 

  221517.   /* Step 5b. */

  221518.   if( nBuf>1 && aBuf[nBuf-1]=='l' 

  221519.    && aBuf[nBuf-2]=='l' && fts5Porter_MGt1(aBuf, nBuf-1) 

  221520.   ){

  221521.     nBuf--;

  221522.   }

  221523. 

  221524.   return p->xToken(p->pCtx, tflags, aBuf, nBuf, iStart, iEnd);

  221525. 

  221526.  pass_through:

  221527.   return p->xToken(p->pCtx, tflags, pToken, nToken, iStart, iEnd);

  221528. }

  221529. 

  221530. /*

  221531. ** Tokenize using the porter tokenizer.

  221532. */

  221533. static int fts5PorterTokenize(

  221534.   Fts5Tokenizer *pTokenizer,

  221535.   void *pCtx,

  221536.   int flags,

  221537.   const char *pText, int nText,

  221538.   int (*xToken)(void*, int, const char*, int nToken, int iStart, int iEnd)

  221539. ){

  221540.   PorterTokenizer *p = (PorterTokenizer*)pTokenizer;

  221541.   PorterContext sCtx;

  221542.   sCtx.xToken = xToken;

  221543.   sCtx.pCtx = pCtx;

  221544.   sCtx.aBuf = p->aBuf;

  221545.   return p->tokenizer.xTokenize(

  221546.       p->pTokenizer, (void*)&sCtx, flags, pText, nText, fts5PorterCb

  221547.   );

  221548. }

  221549. 

  221550. /*

  221551. ** Register all built-in tokenizers with FTS5.

  221552. */

  221553. static int sqlite3Fts5TokenizerInit(fts5_api *pApi){

  221554.   struct BuiltinTokenizer {

  221555.     const char *zName;

  221556.     fts5_tokenizer x;

  221557.   } aBuiltin[] = {

  221558.     { "unicode61", {fts5UnicodeCreate, fts5UnicodeDelete, fts5UnicodeTokenize}},

  221559.     { "ascii",     {fts5AsciiCreate, fts5AsciiDelete, fts5AsciiTokenize }},

  221560.     { "porter",    {fts5PorterCreate, fts5PorterDelete, fts5PorterTokenize }},

  221561.   };

  221562.   

  221563.   int rc = SQLITE_OK;             /* Return code */

  221564.   int i;                          /* To iterate through builtin functions */

  221565. 

  221566.   for(i=0; rc==SQLITE_OK && i<ArraySize(aBuiltin); i++){

  221567.     rc = pApi->xCreateTokenizer(pApi,

  221568.         aBuiltin[i].zName,

  221569.         (void*)pApi,

  221570.         &aBuiltin[i].x,

  221571.         0

  221572.     );

  221573.   }

  221574. 

  221575.   return rc;

  221576. }

  221577. 

  221578. /*

  221579. ** 2012-05-25

  221580. **

  221581. ** The author disclaims copyright to this source code.  In place of

  221582. ** a legal notice, here is a blessing:

  221583. **

  221584. **    May you do good and not evil.

  221585. **    May you find forgiveness for yourself and forgive others.

  221586. **    May you share freely, never taking more than you give.

  221587. **

  221588. ******************************************************************************

  221589. */

  221590. 

  221591. /*

  221592. ** DO NOT EDIT THIS MACHINE GENERATED FILE.

  221593. */

  221594. 

  221595. 

  221596. /* #include <assert.h> */

  221597. 

  221598. 

  221599. 

  221600. /*

  221601. ** If the argument is a codepoint corresponding to a lowercase letter

  221602. ** in the ASCII range with a diacritic added, return the codepoint

  221603. ** of the ASCII letter only. For example, if passed 235 - "LATIN

  221604. ** SMALL LETTER E WITH DIAERESIS" - return 65 ("LATIN SMALL LETTER

  221605. ** E"). The resuls of passing a codepoint that corresponds to an

  221606. ** uppercase letter are undefined.

  221607. */

  221608. static int fts5_remove_diacritic(int c, int bComplex){

  221609.   unsigned short aDia[] = {

  221610.         0,  1797,  1848,  1859,  1891,  1928,  1940,  1995, 

  221611.      2024,  2040,  2060,  2110,  2168,  2206,  2264,  2286, 

  221612.      2344,  2383,  2472,  2488,  2516,  2596,  2668,  2732, 

  221613.      2782,  2842,  2894,  2954,  2984,  3000,  3028,  3336, 

  221614.      3456,  3696,  3712,  3728,  3744,  3766,  3832,  3896, 

  221615.      3912,  3928,  3944,  3968,  4008,  4040,  4056,  4106, 

  221616.      4138,  4170,  4202,  4234,  4266,  4296,  4312,  4344, 

  221617.      4408,  4424,  4442,  4472,  4488,  4504,  6148,  6198, 

  221618.      6264,  6280,  6360,  6429,  6505,  6529, 61448, 61468, 

  221619.     61512, 61534, 61592, 61610, 61642, 61672, 61688, 61704, 

  221620.     61726, 61784, 61800, 61816, 61836, 61880, 61896, 61914, 

  221621.     61948, 61998, 62062, 62122, 62154, 62184, 62200, 62218, 

  221622.     62252, 62302, 62364, 62410, 62442, 62478, 62536, 62554, 

  221623.     62584, 62604, 62640, 62648, 62656, 62664, 62730, 62766, 

  221624.     62830, 62890, 62924, 62974, 63032, 63050, 63082, 63118, 

  221625.     63182, 63242, 63274, 63310, 63368, 63390, 

  221626.   };

  221627. #define HIBIT ((unsigned char)0x80)

  221628.   unsigned char aChar[] = {

  221629.     '\0',      'a',       'c',       'e',       'i',       'n',       

  221630.     'o',       'u',       'y',       'y',       'a',       'c',       

  221631.     'd',       'e',       'e',       'g',       'h',       'i',       

  221632.     'j',       'k',       'l',       'n',       'o',       'r',       

  221633.     's',       't',       'u',       'u',       'w',       'y',       

  221634.     'z',       'o',       'u',       'a',       'i',       'o',       

  221635.     'u',       'u'|HIBIT, 'a'|HIBIT, 'g',       'k',       'o',       

  221636.     'o'|HIBIT, 'j',       'g',       'n',       'a'|HIBIT, 'a',       

  221637.     'e',       'i',       'o',       'r',       'u',       's',       

  221638.     't',       'h',       'a',       'e',       'o'|HIBIT, 'o',       

  221639.     'o'|HIBIT, 'y',       '\0',      '\0',      '\0',      '\0',      

  221640.     '\0',      '\0',      '\0',      '\0',      'a',       'b',       

  221641.     'c'|HIBIT, 'd',       'd',       'e'|HIBIT, 'e',       'e'|HIBIT, 

  221642.     'f',       'g',       'h',       'h',       'i',       'i'|HIBIT, 

  221643.     'k',       'l',       'l'|HIBIT, 'l',       'm',       'n',       

  221644.     'o'|HIBIT, 'p',       'r',       'r'|HIBIT, 'r',       's',       

  221645.     's'|HIBIT, 't',       'u',       'u'|HIBIT, 'v',       'w',       

  221646.     'w',       'x',       'y',       'z',       'h',       't',       

  221647.     'w',       'y',       'a',       'a'|HIBIT, 'a'|HIBIT, 'a'|HIBIT, 

  221648.     'e',       'e'|HIBIT, 'e'|HIBIT, 'i',       'o',       'o'|HIBIT, 

  221649.     'o'|HIBIT, 'o'|HIBIT, 'u',       'u'|HIBIT, 'u'|HIBIT, 'y',       

  221650.   };

  221651. 

  221652.   unsigned int key = (((unsigned int)c)<<3) | 0x00000007;

  221653.   int iRes = 0;

  221654.   int iHi = sizeof(aDia)/sizeof(aDia[0]) - 1;

  221655.   int iLo = 0;

  221656.   while( iHi>=iLo ){

  221657.     int iTest = (iHi + iLo) / 2;

  221658.     if( key >= aDia[iTest] ){

  221659.       iRes = iTest;

  221660.       iLo = iTest+1;

  221661.     }else{

  221662.       iHi = iTest-1;

  221663.     }

  221664.   }

  221665.   assert( key>=aDia[iRes] );

  221666.   if( bComplex==0 && (aChar[iRes] & 0x80) ) return c;

  221667.   return (c > (aDia[iRes]>>3) + (aDia[iRes]&0x07)) ? c : ((int)aChar[iRes] & 0x7F);

  221668. }

  221669. 

  221670. 

  221671. /*

  221672. ** Return true if the argument interpreted as a unicode codepoint

  221673. ** is a diacritical modifier character.

  221674. */

  221675. static int sqlite3Fts5UnicodeIsdiacritic(int c){

  221676.   unsigned int mask0 = 0x08029FDF;

  221677.   unsigned int mask1 = 0x000361F8;

  221678.   if( c<768 || c>817 ) return 0;

  221679.   return (c < 768+32) ?

  221680.       (mask0 & ((unsigned int)1 << (c-768))) :

  221681.       (mask1 & ((unsigned int)1 << (c-768-32)));

  221682. }

  221683. 

  221684. 

  221685. /*

  221686. ** Interpret the argument as a unicode codepoint. If the codepoint

  221687. ** is an upper case character that has a lower case equivalent,

  221688. ** return the codepoint corresponding to the lower case version.

  221689. ** Otherwise, return a copy of the argument.

  221690. **

  221691. ** The results are undefined if the value passed to this function

  221692. ** is less than zero.

  221693. */

  221694. static int sqlite3Fts5UnicodeFold(int c, int eRemoveDiacritic){

  221695.   /* Each entry in the following array defines a rule for folding a range

  221696.   ** of codepoints to lower case. The rule applies to a range of nRange

  221697.   ** codepoints starting at codepoint iCode.

  221698.   **

  221699.   ** If the least significant bit in flags is clear, then the rule applies

  221700.   ** to all nRange codepoints (i.e. all nRange codepoints are upper case and

  221701.   ** need to be folded). Or, if it is set, then the rule only applies to

  221702.   ** every second codepoint in the range, starting with codepoint C.

  221703.   **

  221704.   ** The 7 most significant bits in flags are an index into the aiOff[]

  221705.   ** array. If a specific codepoint C does require folding, then its lower

  221706.   ** case equivalent is ((C + aiOff[flags>>1]) & 0xFFFF).

  221707.   **

  221708.   ** The contents of this array are generated by parsing the CaseFolding.txt

  221709.   ** file distributed as part of the "Unicode Character Database". See

  221710.   ** http://www.unicode.org for details.

  221711.   */

  221712.   static const struct TableEntry {

  221713.     unsigned short iCode;

  221714.     unsigned char flags;

  221715.     unsigned char nRange;

  221716.   } aEntry[] = {

  221717.     {65, 14, 26},          {181, 64, 1},          {192, 14, 23},

  221718.     {216, 14, 7},          {256, 1, 48},          {306, 1, 6},

  221719.     {313, 1, 16},          {330, 1, 46},          {376, 116, 1},

  221720.     {377, 1, 6},           {383, 104, 1},         {385, 50, 1},

  221721.     {386, 1, 4},           {390, 44, 1},          {391, 0, 1},

  221722.     {393, 42, 2},          {395, 0, 1},           {398, 32, 1},

  221723.     {399, 38, 1},          {400, 40, 1},          {401, 0, 1},

  221724.     {403, 42, 1},          {404, 46, 1},          {406, 52, 1},

  221725.     {407, 48, 1},          {408, 0, 1},           {412, 52, 1},

  221726.     {413, 54, 1},          {415, 56, 1},          {416, 1, 6},

  221727.     {422, 60, 1},          {423, 0, 1},           {425, 60, 1},

  221728.     {428, 0, 1},           {430, 60, 1},          {431, 0, 1},

  221729.     {433, 58, 2},          {435, 1, 4},           {439, 62, 1},

  221730.     {440, 0, 1},           {444, 0, 1},           {452, 2, 1},

  221731.     {453, 0, 1},           {455, 2, 1},           {456, 0, 1},

  221732.     {458, 2, 1},           {459, 1, 18},          {478, 1, 18},

  221733.     {497, 2, 1},           {498, 1, 4},           {502, 122, 1},

  221734.     {503, 134, 1},         {504, 1, 40},          {544, 110, 1},

  221735.     {546, 1, 18},          {570, 70, 1},          {571, 0, 1},

  221736.     {573, 108, 1},         {574, 68, 1},          {577, 0, 1},

  221737.     {579, 106, 1},         {580, 28, 1},          {581, 30, 1},

  221738.     {582, 1, 10},          {837, 36, 1},          {880, 1, 4},

  221739.     {886, 0, 1},           {902, 18, 1},          {904, 16, 3},

  221740.     {908, 26, 1},          {910, 24, 2},          {913, 14, 17},

  221741.     {931, 14, 9},          {962, 0, 1},           {975, 4, 1},

  221742.     {976, 140, 1},         {977, 142, 1},         {981, 146, 1},

  221743.     {982, 144, 1},         {984, 1, 24},          {1008, 136, 1},

  221744.     {1009, 138, 1},        {1012, 130, 1},        {1013, 128, 1},

  221745.     {1015, 0, 1},          {1017, 152, 1},        {1018, 0, 1},

  221746.     {1021, 110, 3},        {1024, 34, 16},        {1040, 14, 32},

  221747.     {1120, 1, 34},         {1162, 1, 54},         {1216, 6, 1},

  221748.     {1217, 1, 14},         {1232, 1, 88},         {1329, 22, 38},

  221749.     {4256, 66, 38},        {4295, 66, 1},         {4301, 66, 1},

  221750.     {7680, 1, 150},        {7835, 132, 1},        {7838, 96, 1},

  221751.     {7840, 1, 96},         {7944, 150, 8},        {7960, 150, 6},

  221752.     {7976, 150, 8},        {7992, 150, 8},        {8008, 150, 6},

  221753.     {8025, 151, 8},        {8040, 150, 8},        {8072, 150, 8},

  221754.     {8088, 150, 8},        {8104, 150, 8},        {8120, 150, 2},

  221755.     {8122, 126, 2},        {8124, 148, 1},        {8126, 100, 1},

  221756.     {8136, 124, 4},        {8140, 148, 1},        {8152, 150, 2},

  221757.     {8154, 120, 2},        {8168, 150, 2},        {8170, 118, 2},

  221758.     {8172, 152, 1},        {8184, 112, 2},        {8186, 114, 2},

  221759.     {8188, 148, 1},        {8486, 98, 1},         {8490, 92, 1},

  221760.     {8491, 94, 1},         {8498, 12, 1},         {8544, 8, 16},

  221761.     {8579, 0, 1},          {9398, 10, 26},        {11264, 22, 47},

  221762.     {11360, 0, 1},         {11362, 88, 1},        {11363, 102, 1},

  221763.     {11364, 90, 1},        {11367, 1, 6},         {11373, 84, 1},

  221764.     {11374, 86, 1},        {11375, 80, 1},        {11376, 82, 1},

  221765.     {11378, 0, 1},         {11381, 0, 1},         {11390, 78, 2},

  221766.     {11392, 1, 100},       {11499, 1, 4},         {11506, 0, 1},

  221767.     {42560, 1, 46},        {42624, 1, 24},        {42786, 1, 14},

  221768.     {42802, 1, 62},        {42873, 1, 4},         {42877, 76, 1},

  221769.     {42878, 1, 10},        {42891, 0, 1},         {42893, 74, 1},

  221770.     {42896, 1, 4},         {42912, 1, 10},        {42922, 72, 1},

  221771.     {65313, 14, 26},       

  221772.   };

  221773.   static const unsigned short aiOff[] = {

  221774.    1,     2,     8,     15,    16,    26,    28,    32,    

  221775.    37,    38,    40,    48,    63,    64,    69,    71,    

  221776.    79,    80,    116,   202,   203,   205,   206,   207,   

  221777.    209,   210,   211,   213,   214,   217,   218,   219,   

  221778.    775,   7264,  10792, 10795, 23228, 23256, 30204, 54721, 

  221779.    54753, 54754, 54756, 54787, 54793, 54809, 57153, 57274, 

  221780.    57921, 58019, 58363, 61722, 65268, 65341, 65373, 65406, 

  221781.    65408, 65410, 65415, 65424, 65436, 65439, 65450, 65462, 

  221782.    65472, 65476, 65478, 65480, 65482, 65488, 65506, 65511, 

  221783.    65514, 65521, 65527, 65528, 65529, 

  221784.   };

  221785. 

  221786.   int ret = c;

  221787. 

  221788.   assert( sizeof(unsigned short)==2 && sizeof(unsigned char)==1 );

  221789. 

  221790.   if( c<128 ){

  221791.     if( c>='A' && c<='Z' ) ret = c + ('a' - 'A');

  221792.   }else if( c<65536 ){

  221793.     const struct TableEntry *p;

  221794.     int iHi = sizeof(aEntry)/sizeof(aEntry[0]) - 1;

  221795.     int iLo = 0;

  221796.     int iRes = -1;

  221797. 

  221798.     assert( c>aEntry[0].iCode );

  221799.     while( iHi>=iLo ){

  221800.       int iTest = (iHi + iLo) / 2;

  221801.       int cmp = (c - aEntry[iTest].iCode);

  221802.       if( cmp>=0 ){

  221803.         iRes = iTest;

  221804.         iLo = iTest+1;

  221805.       }else{

  221806.         iHi = iTest-1;

  221807.       }

  221808.     }

  221809. 

  221810.     assert( iRes>=0 && c>=aEntry[iRes].iCode );

  221811.     p = &aEntry[iRes];

  221812.     if( c<(p->iCode + p->nRange) && 0==(0x01 & p->flags & (p->iCode ^ c)) ){

  221813.       ret = (c + (aiOff[p->flags>>1])) & 0x0000FFFF;

  221814.       assert( ret>0 );

  221815.     }

  221816. 

  221817.     if( eRemoveDiacritic ){

  221818.       ret = fts5_remove_diacritic(ret, eRemoveDiacritic==2);

  221819.     }

  221820.   }

  221821.   

  221822.   else if( c>=66560 && c<66600 ){

  221823.     ret = c + 40;

  221824.   }

  221825. 

  221826.   return ret;

  221827. }

  221828. 

  221829. 

  221830. static int sqlite3Fts5UnicodeCatParse(const char *zCat, u8 *aArray){ 

  221831.   aArray[0] = 1;

  221832.   switch( zCat[0] ){

  221833.     case 'C':

  221834.           switch( zCat[1] ){

  221835.             case 'c': aArray[1] = 1; break;

  221836.             case 'f': aArray[2] = 1; break;

  221837.             case 'n': aArray[3] = 1; break;

  221838.             case 's': aArray[4] = 1; break;

  221839.             case 'o': aArray[31] = 1; break;

  221840.             case '*': 

  221841.               aArray[1] = 1;

  221842.               aArray[2] = 1;

  221843.               aArray[3] = 1;

  221844.               aArray[4] = 1;

  221845.               aArray[31] = 1;

  221846.               break;

  221847.             default: return 1;          }

  221848.           break;

  221849. 

  221850.     case 'L':

  221851.           switch( zCat[1] ){

  221852.             case 'l': aArray[5] = 1; break;

  221853.             case 'm': aArray[6] = 1; break;

  221854.             case 'o': aArray[7] = 1; break;

  221855.             case 't': aArray[8] = 1; break;

  221856.             case 'u': aArray[9] = 1; break;

  221857.             case 'C': aArray[30] = 1; break;

  221858.             case '*': 

  221859.               aArray[5] = 1;

  221860.               aArray[6] = 1;

  221861.               aArray[7] = 1;

  221862.               aArray[8] = 1;

  221863.               aArray[9] = 1;

  221864.               aArray[30] = 1;

  221865.               break;

  221866.             default: return 1;          }

  221867.           break;

  221868. 

  221869.     case 'M':

  221870.           switch( zCat[1] ){

  221871.             case 'c': aArray[10] = 1; break;

  221872.             case 'e': aArray[11] = 1; break;

  221873.             case 'n': aArray[12] = 1; break;

  221874.             case '*': 

  221875.               aArray[10] = 1;

  221876.               aArray[11] = 1;

  221877.               aArray[12] = 1;

  221878.               break;

  221879.             default: return 1;          }

  221880.           break;

  221881. 

  221882.     case 'N':

  221883.           switch( zCat[1] ){

  221884.             case 'd': aArray[13] = 1; break;

  221885.             case 'l': aArray[14] = 1; break;

  221886.             case 'o': aArray[15] = 1; break;

  221887.             case '*': 

  221888.               aArray[13] = 1;

  221889.               aArray[14] = 1;

  221890.               aArray[15] = 1;

  221891.               break;

  221892.             default: return 1;          }

  221893.           break;

  221894. 

  221895.     case 'P':

  221896.           switch( zCat[1] ){

  221897.             case 'c': aArray[16] = 1; break;

  221898.             case 'd': aArray[17] = 1; break;

  221899.             case 'e': aArray[18] = 1; break;

  221900.             case 'f': aArray[19] = 1; break;

  221901.             case 'i': aArray[20] = 1; break;

  221902.             case 'o': aArray[21] = 1; break;

  221903.             case 's': aArray[22] = 1; break;

  221904.             case '*': 

  221905.               aArray[16] = 1;

  221906.               aArray[17] = 1;

  221907.               aArray[18] = 1;

  221908.               aArray[19] = 1;

  221909.               aArray[20] = 1;

  221910.               aArray[21] = 1;

  221911.               aArray[22] = 1;

  221912.               break;

  221913.             default: return 1;          }

  221914.           break;

  221915. 

  221916.     case 'S':

  221917.           switch( zCat[1] ){

  221918.             case 'c': aArray[23] = 1; break;

  221919.             case 'k': aArray[24] = 1; break;

  221920.             case 'm': aArray[25] = 1; break;

  221921.             case 'o': aArray[26] = 1; break;

  221922.             case '*': 

  221923.               aArray[23] = 1;

  221924.               aArray[24] = 1;

  221925.               aArray[25] = 1;

  221926.               aArray[26] = 1;

  221927.               break;

  221928.             default: return 1;          }

  221929.           break;

  221930. 

  221931.     case 'Z':

  221932.           switch( zCat[1] ){

  221933.             case 'l': aArray[27] = 1; break;

  221934.             case 'p': aArray[28] = 1; break;

  221935.             case 's': aArray[29] = 1; break;

  221936.             case '*': 

  221937.               aArray[27] = 1;

  221938.               aArray[28] = 1;

  221939.               aArray[29] = 1;

  221940.               break;

  221941.             default: return 1;          }

  221942.           break;

  221943. 

  221944.   }

  221945.   return 0;

  221946. }

  221947. 

  221948. static u16 aFts5UnicodeBlock[] = {

  221949.     0,     1471,  1753,  1760,  1760,  1760,  1760,  1760,  1760,  1760,  

  221950.     1760,  1760,  1760,  1760,  1760,  1763,  1765,  

  221951.   };

  221952. static u16 aFts5UnicodeMap[] = {

  221953.     0,     32,    33,    36,    37,    40,    41,    42,    43,    44,    

  221954.     45,    46,    48,    58,    60,    63,    65,    91,    92,    93,    

  221955.     94,    95,    96,    97,    123,   124,   125,   126,   127,   160,   

  221956.     161,   162,   166,   167,   168,   169,   170,   171,   172,   173,   

  221957.     174,   175,   176,   177,   178,   180,   181,   182,   184,   185,   

  221958.     186,   187,   188,   191,   192,   215,   216,   223,   247,   248,   

  221959.     256,   312,   313,   329,   330,   377,   383,   385,   387,   388,   

  221960.     391,   394,   396,   398,   402,   403,   405,   406,   409,   412,   

  221961.     414,   415,   417,   418,   423,   427,   428,   431,   434,   436,   

  221962.     437,   440,   442,   443,   444,   446,   448,   452,   453,   454,   

  221963.     455,   456,   457,   458,   459,   460,   461,   477,   478,   496,   

  221964.     497,   498,   499,   500,   503,   505,   506,   564,   570,   572,   

  221965.     573,   575,   577,   580,   583,   584,   592,   660,   661,   688,   

  221966.     706,   710,   722,   736,   741,   748,   749,   750,   751,   768,   

  221967.     880,   884,   885,   886,   890,   891,   894,   900,   902,   903,   

  221968.     904,   908,   910,   912,   913,   931,   940,   975,   977,   978,   

  221969.     981,   984,   1008,  1012,  1014,  1015,  1018,  1020,  1021,  1072,  

  221970.     1120,  1154,  1155,  1160,  1162,  1217,  1231,  1232,  1329,  1369,  

  221971.     1370,  1377,  1417,  1418,  1423,  1425,  1470,  1471,  1472,  1473,  

  221972.     1475,  1476,  1478,  1479,  1488,  1520,  1523,  1536,  1542,  1545,  

  221973.     1547,  1548,  1550,  1552,  1563,  1566,  1568,  1600,  1601,  1611,  

  221974.     1632,  1642,  1646,  1648,  1649,  1748,  1749,  1750,  1757,  1758,  

  221975.     1759,  1765,  1767,  1769,  1770,  1774,  1776,  1786,  1789,  1791,  

  221976.     1792,  1807,  1808,  1809,  1810,  1840,  1869,  1958,  1969,  1984,  

  221977.     1994,  2027,  2036,  2038,  2039,  2042,  2048,  2070,  2074,  2075,  

  221978.     2084,  2085,  2088,  2089,  2096,  2112,  2137,  2142,  2208,  2210,  

  221979.     2276,  2304,  2307,  2308,  2362,  2363,  2364,  2365,  2366,  2369,  

  221980.     2377,  2381,  2382,  2384,  2385,  2392,  2402,  2404,  2406,  2416,  

  221981.     2417,  2418,  2425,  2433,  2434,  2437,  2447,  2451,  2474,  2482,  

  221982.     2486,  2492,  2493,  2494,  2497,  2503,  2507,  2509,  2510,  2519,  

  221983.     2524,  2527,  2530,  2534,  2544,  2546,  2548,  2554,  2555,  2561,  

  221984.     2563,  2565,  2575,  2579,  2602,  2610,  2613,  2616,  2620,  2622,  

  221985.     2625,  2631,  2635,  2641,  2649,  2654,  2662,  2672,  2674,  2677,  

  221986.     2689,  2691,  2693,  2703,  2707,  2730,  2738,  2741,  2748,  2749,  

  221987.     2750,  2753,  2759,  2761,  2763,  2765,  2768,  2784,  2786,  2790,  

  221988.     2800,  2801,  2817,  2818,  2821,  2831,  2835,  2858,  2866,  2869,  

  221989.     2876,  2877,  2878,  2879,  2880,  2881,  2887,  2891,  2893,  2902,  

  221990.     2903,  2908,  2911,  2914,  2918,  2928,  2929,  2930,  2946,  2947,  

  221991.     2949,  2958,  2962,  2969,  2972,  2974,  2979,  2984,  2990,  3006,  

  221992.     3008,  3009,  3014,  3018,  3021,  3024,  3031,  3046,  3056,  3059,  

  221993.     3065,  3066,  3073,  3077,  3086,  3090,  3114,  3125,  3133,  3134,  

  221994.     3137,  3142,  3146,  3157,  3160,  3168,  3170,  3174,  3192,  3199,  

  221995.     3202,  3205,  3214,  3218,  3242,  3253,  3260,  3261,  3262,  3263,  

  221996.     3264,  3270,  3271,  3274,  3276,  3285,  3294,  3296,  3298,  3302,  

  221997.     3313,  3330,  3333,  3342,  3346,  3389,  3390,  3393,  3398,  3402,  

  221998.     3405,  3406,  3415,  3424,  3426,  3430,  3440,  3449,  3450,  3458,  

  221999.     3461,  3482,  3507,  3517,  3520,  3530,  3535,  3538,  3542,  3544,  

  222000.     3570,  3572,  3585,  3633,  3634,  3636,  3647,  3648,  3654,  3655,  

  222001.     3663,  3664,  3674,  3713,  3716,  3719,  3722,  3725,  3732,  3737,  

  222002.     3745,  3749,  3751,  3754,  3757,  3761,  3762,  3764,  3771,  3773,  

  222003.     3776,  3782,  3784,  3792,  3804,  3840,  3841,  3844,  3859,  3860,  

  222004.     3861,  3864,  3866,  3872,  3882,  3892,  3893,  3894,  3895,  3896,  

  222005.     3897,  3898,  3899,  3900,  3901,  3902,  3904,  3913,  3953,  3967,  

  222006.     3968,  3973,  3974,  3976,  3981,  3993,  4030,  4038,  4039,  4046,  

  222007.     4048,  4053,  4057,  4096,  4139,  4141,  4145,  4146,  4152,  4153,  

  222008.     4155,  4157,  4159,  4160,  4170,  4176,  4182,  4184,  4186,  4190,  

  222009.     4193,  4194,  4197,  4199,  4206,  4209,  4213,  4226,  4227,  4229,  

  222010.     4231,  4237,  4238,  4239,  4240,  4250,  4253,  4254,  4256,  4295,  

  222011.     4301,  4304,  4347,  4348,  4349,  4682,  4688,  4696,  4698,  4704,  

  222012.     4746,  4752,  4786,  4792,  4800,  4802,  4808,  4824,  4882,  4888,  

  222013.     4957,  4960,  4969,  4992,  5008,  5024,  5120,  5121,  5741,  5743,  

  222014.     5760,  5761,  5787,  5788,  5792,  5867,  5870,  5888,  5902,  5906,  

  222015.     5920,  5938,  5941,  5952,  5970,  5984,  5998,  6002,  6016,  6068,  

  222016.     6070,  6071,  6078,  6086,  6087,  6089,  6100,  6103,  6104,  6107,  

  222017.     6108,  6109,  6112,  6128,  6144,  6150,  6151,  6155,  6158,  6160,  

  222018.     6176,  6211,  6212,  6272,  6313,  6314,  6320,  6400,  6432,  6435,  

  222019.     6439,  6441,  6448,  6450,  6451,  6457,  6464,  6468,  6470,  6480,  

  222020.     6512,  6528,  6576,  6593,  6600,  6608,  6618,  6622,  6656,  6679,  

  222021.     6681,  6686,  6688,  6741,  6742,  6743,  6744,  6752,  6753,  6754,  

  222022.     6755,  6757,  6765,  6771,  6783,  6784,  6800,  6816,  6823,  6824,  

  222023.     6912,  6916,  6917,  6964,  6965,  6966,  6971,  6972,  6973,  6978,  

  222024.     6979,  6981,  6992,  7002,  7009,  7019,  7028,  7040,  7042,  7043,  

  222025.     7073,  7074,  7078,  7080,  7082,  7083,  7084,  7086,  7088,  7098,  

  222026.     7142,  7143,  7144,  7146,  7149,  7150,  7151,  7154,  7164,  7168,  

  222027.     7204,  7212,  7220,  7222,  7227,  7232,  7245,  7248,  7258,  7288,  

  222028.     7294,  7360,  7376,  7379,  7380,  7393,  7394,  7401,  7405,  7406,  

  222029.     7410,  7412,  7413,  7424,  7468,  7531,  7544,  7545,  7579,  7616,  

  222030.     7676,  7680,  7830,  7838,  7936,  7944,  7952,  7960,  7968,  7976,  

  222031.     7984,  7992,  8000,  8008,  8016,  8025,  8027,  8029,  8031,  8033,  

  222032.     8040,  8048,  8064,  8072,  8080,  8088,  8096,  8104,  8112,  8118,  

  222033.     8120,  8124,  8125,  8126,  8127,  8130,  8134,  8136,  8140,  8141,  

  222034.     8144,  8150,  8152,  8157,  8160,  8168,  8173,  8178,  8182,  8184,  

  222035.     8188,  8189,  8192,  8203,  8208,  8214,  8216,  8217,  8218,  8219,  

  222036.     8221,  8222,  8223,  8224,  8232,  8233,  8234,  8239,  8240,  8249,  

  222037.     8250,  8251,  8255,  8257,  8260,  8261,  8262,  8263,  8274,  8275,  

  222038.     8276,  8277,  8287,  8288,  8298,  8304,  8305,  8308,  8314,  8317,  

  222039.     8318,  8319,  8320,  8330,  8333,  8334,  8336,  8352,  8400,  8413,  

  222040.     8417,  8418,  8421,  8448,  8450,  8451,  8455,  8456,  8458,  8459,  

  222041.     8462,  8464,  8467,  8468,  8469,  8470,  8472,  8473,  8478,  8484,  

  222042.     8485,  8486,  8487,  8488,  8489,  8490,  8494,  8495,  8496,  8500,  

  222043.     8501,  8505,  8506,  8508,  8510,  8512,  8517,  8519,  8522,  8523,  

  222044.     8524,  8526,  8527,  8528,  8544,  8579,  8581,  8585,  8592,  8597,  

  222045.     8602,  8604,  8608,  8609,  8611,  8612,  8614,  8615,  8622,  8623,  

  222046.     8654,  8656,  8658,  8659,  8660,  8661,  8692,  8960,  8968,  8972,  

  222047.     8992,  8994,  9001,  9002,  9003,  9084,  9085,  9115,  9140,  9180,  

  222048.     9186,  9216,  9280,  9312,  9372,  9450,  9472,  9655,  9656,  9665,  

  222049.     9666,  9720,  9728,  9839,  9840,  9985,  10088, 10089, 10090, 10091, 

  222050.     10092, 10093, 10094, 10095, 10096, 10097, 10098, 10099, 10100, 10101, 

  222051.     10102, 10132, 10176, 10181, 10182, 10183, 10214, 10215, 10216, 10217, 

  222052.     10218, 10219, 10220, 10221, 10222, 10223, 10224, 10240, 10496, 10627, 

  222053.     10628, 10629, 10630, 10631, 10632, 10633, 10634, 10635, 10636, 10637, 

  222054.     10638, 10639, 10640, 10641, 10642, 10643, 10644, 10645, 10646, 10647, 

  222055.     10648, 10649, 10712, 10713, 10714, 10715, 10716, 10748, 10749, 10750, 

  222056.     11008, 11056, 11077, 11079, 11088, 11264, 11312, 11360, 11363, 11365, 

  222057.     11367, 11374, 11377, 11378, 11380, 11381, 11383, 11388, 11390, 11393, 

  222058.     11394, 11492, 11493, 11499, 11503, 11506, 11513, 11517, 11518, 11520, 

  222059.     11559, 11565, 11568, 11631, 11632, 11647, 11648, 11680, 11688, 11696, 

  222060.     11704, 11712, 11720, 11728, 11736, 11744, 11776, 11778, 11779, 11780, 

  222061.     11781, 11782, 11785, 11786, 11787, 11788, 11789, 11790, 11799, 11800, 

  222062.     11802, 11803, 11804, 11805, 11806, 11808, 11809, 11810, 11811, 11812, 

  222063.     11813, 11814, 11815, 11816, 11817, 11818, 11823, 11824, 11834, 11904, 

  222064.     11931, 12032, 12272, 12288, 12289, 12292, 12293, 12294, 12295, 12296, 

  222065.     12297, 12298, 12299, 12300, 12301, 12302, 12303, 12304, 12305, 12306, 

  222066.     12308, 12309, 12310, 12311, 12312, 12313, 12314, 12315, 12316, 12317, 

  222067.     12318, 12320, 12321, 12330, 12334, 12336, 12337, 12342, 12344, 12347, 

  222068.     12348, 12349, 12350, 12353, 12441, 12443, 12445, 12447, 12448, 12449, 

  222069.     12539, 12540, 12543, 12549, 12593, 12688, 12690, 12694, 12704, 12736, 

  222070.     12784, 12800, 12832, 12842, 12872, 12880, 12881, 12896, 12928, 12938, 

  222071.     12977, 12992, 13056, 13312, 19893, 19904, 19968, 40908, 40960, 40981, 

  222072.     40982, 42128, 42192, 42232, 42238, 42240, 42508, 42509, 42512, 42528, 

  222073.     42538, 42560, 42606, 42607, 42608, 42611, 42612, 42622, 42623, 42624, 

  222074.     42655, 42656, 42726, 42736, 42738, 42752, 42775, 42784, 42786, 42800, 

  222075.     42802, 42864, 42865, 42873, 42878, 42888, 42889, 42891, 42896, 42912, 

  222076.     43000, 43002, 43003, 43010, 43011, 43014, 43015, 43019, 43020, 43043, 

  222077.     43045, 43047, 43048, 43056, 43062, 43064, 43065, 43072, 43124, 43136, 

  222078.     43138, 43188, 43204, 43214, 43216, 43232, 43250, 43256, 43259, 43264, 

  222079.     43274, 43302, 43310, 43312, 43335, 43346, 43359, 43360, 43392, 43395, 

  222080.     43396, 43443, 43444, 43446, 43450, 43452, 43453, 43457, 43471, 43472, 

  222081.     43486, 43520, 43561, 43567, 43569, 43571, 43573, 43584, 43587, 43588, 

  222082.     43596, 43597, 43600, 43612, 43616, 43632, 43633, 43639, 43642, 43643, 

  222083.     43648, 43696, 43697, 43698, 43701, 43703, 43705, 43710, 43712, 43713, 

  222084.     43714, 43739, 43741, 43742, 43744, 43755, 43756, 43758, 43760, 43762, 

  222085.     43763, 43765, 43766, 43777, 43785, 43793, 43808, 43816, 43968, 44003, 

  222086.     44005, 44006, 44008, 44009, 44011, 44012, 44013, 44016, 44032, 55203, 

  222087.     55216, 55243, 55296, 56191, 56319, 57343, 57344, 63743, 63744, 64112, 

  222088.     64256, 64275, 64285, 64286, 64287, 64297, 64298, 64312, 64318, 64320, 

  222089.     64323, 64326, 64434, 64467, 64830, 64831, 64848, 64914, 65008, 65020, 

  222090.     65021, 65024, 65040, 65047, 65048, 65049, 65056, 65072, 65073, 65075, 

  222091.     65077, 65078, 65079, 65080, 65081, 65082, 65083, 65084, 65085, 65086, 

  222092.     65087, 65088, 65089, 65090, 65091, 65092, 65093, 65095, 65096, 65097, 

  222093.     65101, 65104, 65108, 65112, 65113, 65114, 65115, 65116, 65117, 65118, 

  222094.     65119, 65122, 65123, 65124, 65128, 65129, 65130, 65136, 65142, 65279, 

  222095.     65281, 65284, 65285, 65288, 65289, 65290, 65291, 65292, 65293, 65294, 

  222096.     65296, 65306, 65308, 65311, 65313, 65339, 65340, 65341, 65342, 65343, 

  222097.     65344, 65345, 65371, 65372, 65373, 65374, 65375, 65376, 65377, 65378, 

  222098.     65379, 65380, 65382, 65392, 65393, 65438, 65440, 65474, 65482, 65490, 

  222099.     65498, 65504, 65506, 65507, 65508, 65509, 65512, 65513, 65517, 65529, 

  222100.     65532, 0,     13,    40,    60,    63,    80,    128,   256,   263,   

  222101.     311,   320,   373,   377,   394,   400,   464,   509,   640,   672,   

  222102.     768,   800,   816,   833,   834,   842,   896,   927,   928,   968,   

  222103.     976,   977,   1024,  1064,  1104,  1184,  2048,  2056,  2058,  2103,  

  222104.     2108,  2111,  2135,  2136,  2304,  2326,  2335,  2336,  2367,  2432,  

  222105.     2494,  2560,  2561,  2565,  2572,  2576,  2581,  2585,  2616,  2623,  

  222106.     2624,  2640,  2656,  2685,  2687,  2816,  2873,  2880,  2904,  2912,  

  222107.     2936,  3072,  3680,  4096,  4097,  4098,  4099,  4152,  4167,  4178,  

  222108.     4198,  4224,  4226,  4227,  4272,  4275,  4279,  4281,  4283,  4285,  

  222109.     4286,  4304,  4336,  4352,  4355,  4391,  4396,  4397,  4406,  4416,  

  222110.     4480,  4482,  4483,  4531,  4534,  4543,  4545,  4549,  4560,  5760,  

  222111.     5803,  5804,  5805,  5806,  5808,  5814,  5815,  5824,  8192,  9216,  

  222112.     9328,  12288, 26624, 28416, 28496, 28497, 28559, 28563, 45056, 53248, 

  222113.     53504, 53545, 53605, 53607, 53610, 53613, 53619, 53627, 53635, 53637, 

  222114.     53644, 53674, 53678, 53760, 53826, 53829, 54016, 54112, 54272, 54298, 

  222115.     54324, 54350, 54358, 54376, 54402, 54428, 54430, 54434, 54437, 54441, 

  222116.     54446, 54454, 54459, 54461, 54469, 54480, 54506, 54532, 54535, 54541, 

  222117.     54550, 54558, 54584, 54587, 54592, 54598, 54602, 54610, 54636, 54662, 

  222118.     54688, 54714, 54740, 54766, 54792, 54818, 54844, 54870, 54896, 54922, 

  222119.     54952, 54977, 54978, 55003, 55004, 55010, 55035, 55036, 55061, 55062, 

  222120.     55068, 55093, 55094, 55119, 55120, 55126, 55151, 55152, 55177, 55178, 

  222121.     55184, 55209, 55210, 55235, 55236, 55242, 55246, 60928, 60933, 60961, 

  222122.     60964, 60967, 60969, 60980, 60985, 60987, 60994, 60999, 61001, 61003, 

  222123.     61005, 61009, 61012, 61015, 61017, 61019, 61021, 61023, 61025, 61028, 

  222124.     61031, 61036, 61044, 61049, 61054, 61056, 61067, 61089, 61093, 61099, 

  222125.     61168, 61440, 61488, 61600, 61617, 61633, 61649, 61696, 61712, 61744, 

  222126.     61808, 61926, 61968, 62016, 62032, 62208, 62256, 62263, 62336, 62368, 

  222127.     62406, 62432, 62464, 62528, 62530, 62713, 62720, 62784, 62800, 62971, 

  222128.     63045, 63104, 63232, 0,     42710, 42752, 46900, 46912, 47133, 63488, 

  222129.     1,     32,    256,   0,     65533, 

  222130.   };

  222131. static u16 aFts5UnicodeData[] = {

  222132.     1025,  61,    117,   55,    117,   54,    50,    53,    57,    53,    

  222133.     49,    85,    333,   85,    121,   85,    841,   54,    53,    50,    

  222134.     56,    48,    56,    837,   54,    57,    50,    57,    1057,  61,    

  222135.     53,    151,   58,    53,    56,    58,    39,    52,    57,    34,    

  222136.     58,    56,    58,    57,    79,    56,    37,    85,    56,    47,    

  222137.     39,    51,    111,   53,    745,   57,    233,   773,   57,    261,   

  222138.     1822,  37,    542,   37,    1534,  222,   69,    73,    37,    126,   

  222139.     126,   73,    69,    137,   37,    73,    37,    105,   101,   73,    

  222140.     37,    73,    37,    190,   158,   37,    126,   126,   73,    37,    

  222141.     126,   94,    37,    39,    94,    69,    135,   41,    40,    37,    

  222142.     41,    40,    37,    41,    40,    37,    542,   37,    606,   37,    

  222143.     41,    40,    37,    126,   73,    37,    1886,  197,   73,    37,    

  222144.     73,    69,    126,   105,   37,    286,   2181,  39,    869,   582,   

  222145.     152,   390,   472,   166,   248,   38,    56,    38,    568,   3596,  

  222146.     158,   38,    56,    94,    38,    101,   53,    88,    41,    53,    

  222147.     105,   41,    73,    37,    553,   297,   1125,  94,    37,    105,   

  222148.     101,   798,   133,   94,    57,    126,   94,    37,    1641,  1541,  

  222149.     1118,  58,    172,   75,    1790,  478,   37,    2846,  1225,  38,    

  222150.     213,   1253,  53,    49,    55,    1452,  49,    44,    53,    76,    

  222151.     53,    76,    53,    44,    871,   103,   85,    162,   121,   85,    

  222152.     55,    85,    90,    364,   53,    85,    1031,  38,    327,   684,   

  222153.     333,   149,   71,    44,    3175,  53,    39,    236,   34,    58,    

  222154.     204,   70,    76,    58,    140,   71,    333,   103,   90,    39,    

  222155.     469,   34,    39,    44,    967,   876,   2855,  364,   39,    333,   

  222156.     1063,  300,   70,    58,    117,   38,    711,   140,   38,    300,   

  222157.     38,    108,   38,    172,   501,   807,   108,   53,    39,    359,   

  222158.     876,   108,   42,    1735,  44,    42,    44,    39,    106,   268,   

  222159.     138,   44,    74,    39,    236,   327,   76,    85,    333,   53,    

  222160.     38,    199,   231,   44,    74,    263,   71,    711,   231,   39,    

  222161.     135,   44,    39,    106,   140,   74,    74,    44,    39,    42,    

  222162.     71,    103,   76,    333,   71,    87,    207,   58,    55,    76,    

  222163.     42,    199,   71,    711,   231,   71,    71,    71,    44,    106,   

  222164.     76,    76,    108,   44,    135,   39,    333,   76,    103,   44,    

  222165.     76,    42,    295,   103,   711,   231,   71,    167,   44,    39,    

  222166.     106,   172,   76,    42,    74,    44,    39,    71,    76,    333,   

  222167.     53,    55,    44,    74,    263,   71,    711,   231,   71,    167,   

  222168.     44,    39,    42,    44,    42,    140,   74,    74,    44,    44,    

  222169.     42,    71,    103,   76,    333,   58,    39,    207,   44,    39,    

  222170.     199,   103,   135,   71,    39,    71,    71,    103,   391,   74,    

  222171.     44,    74,    106,   106,   44,    39,    42,    333,   111,   218,   

  222172.     55,    58,    106,   263,   103,   743,   327,   167,   39,    108,   

  222173.     138,   108,   140,   76,    71,    71,    76,    333,   239,   58,    

  222174.     74,    263,   103,   743,   327,   167,   44,    39,    42,    44,    

  222175.     170,   44,    74,    74,    76,    74,    39,    71,    76,    333,   

  222176.     71,    74,    263,   103,   1319,  39,    106,   140,   106,   106,   

  222177.     44,    39,    42,    71,    76,    333,   207,   58,    199,   74,    

  222178.     583,   775,   295,   39,    231,   44,    106,   108,   44,    266,   

  222179.     74,    53,    1543,  44,    71,    236,   55,    199,   38,    268,   

  222180.     53,    333,   85,    71,    39,    71,    39,    39,    135,   231,   

  222181.     103,   39,    39,    71,    135,   44,    71,    204,   76,    39,    

  222182.     167,   38,    204,   333,   135,   39,    122,   501,   58,    53,    

  222183.     122,   76,    218,   333,   335,   58,    44,    58,    44,    58,    

  222184.     44,    54,    50,    54,    50,    74,    263,   1159,  460,   42,    

  222185.     172,   53,    76,    167,   364,   1164,  282,   44,    218,   90,    

  222186.     181,   154,   85,    1383,  74,    140,   42,    204,   42,    76,    

  222187.     74,    76,    39,    333,   213,   199,   74,    76,    135,   108,   

  222188.     39,    106,   71,    234,   103,   140,   423,   44,    74,    76,    

  222189.     202,   44,    39,    42,    333,   106,   44,    90,    1225,  41,    

  222190.     41,    1383,  53,    38,    10631, 135,   231,   39,    135,   1319,  

  222191.     135,   1063,  135,   231,   39,    135,   487,   1831,  135,   2151,  

  222192.     108,   309,   655,   519,   346,   2727,  49,    19847, 85,    551,   

  222193.     61,    839,   54,    50,    2407,  117,   110,   423,   135,   108,   

  222194.     583,   108,   85,    583,   76,    423,   103,   76,    1671,  76,    

  222195.     42,    236,   266,   44,    74,    364,   117,   38,    117,   55,    

  222196.     39,    44,    333,   335,   213,   49,    149,   108,   61,    333,   

  222197.     1127,  38,    1671,  1319,  44,    39,    2247,  935,   108,   138,   

  222198.     76,    106,   74,    44,    202,   108,   58,    85,    333,   967,   

  222199.     167,   1415,  554,   231,   74,    333,   47,    1114,  743,   76,    

  222200.     106,   85,    1703,  42,    44,    42,    236,   44,    42,    44,    

  222201.     74,    268,   202,   332,   44,    333,   333,   245,   38,    213,   

  222202.     140,   42,    1511,  44,    42,    172,   42,    44,    170,   44,    

  222203.     74,    231,   333,   245,   346,   300,   314,   76,    42,    967,   

  222204.     42,    140,   74,    76,    42,    44,    74,    71,    333,   1415,  

  222205.     44,    42,    76,    106,   44,    42,    108,   74,    149,   1159,  

  222206.     266,   268,   74,    76,    181,   333,   103,   333,   967,   198,   

  222207.     85,    277,   108,   53,    428,   42,    236,   135,   44,    135,   

  222208.     74,    44,    71,    1413,  2022,  421,   38,    1093,  1190,  1260,  

  222209.     140,   4830,  261,   3166,  261,   265,   197,   201,   261,   265,   

  222210.     261,   265,   197,   201,   261,   41,    41,    41,    94,    229,   

  222211.     265,   453,   261,   264,   261,   264,   261,   264,   165,   69,    

  222212.     137,   40,    56,    37,    120,   101,   69,    137,   40,    120,   

  222213.     133,   69,    137,   120,   261,   169,   120,   101,   69,    137,   

  222214.     40,    88,    381,   162,   209,   85,    52,    51,    54,    84,    

  222215.     51,    54,    52,    277,   59,    60,    162,   61,    309,   52,    

  222216.     51,    149,   80,    117,   57,    54,    50,    373,   57,    53,    

  222217.     48,    341,   61,    162,   194,   47,    38,    207,   121,   54,    

  222218.     50,    38,    335,   121,   54,    50,    422,   855,   428,   139,   

  222219.     44,    107,   396,   90,    41,    154,   41,    90,    37,    105,   

  222220.     69,    105,   37,    58,    41,    90,    57,    169,   218,   41,    

  222221.     58,    41,    58,    41,    58,    137,   58,    37,    137,   37,    

  222222.     135,   37,    90,    69,    73,    185,   94,    101,   58,    57,    

  222223.     90,    37,    58,    527,   1134,  94,    142,   47,    185,   186,   

  222224.     89,    154,   57,    90,    57,    90,    57,    250,   57,    1018,  

  222225.     89,    90,    57,    58,    57,    1018,  8601,  282,   153,   666,   

  222226.     89,    250,   54,    50,    2618,  57,    986,   825,   1306,  217,   

  222227.     602,   1274,  378,   1935,  2522,  719,   5882,  57,    314,   57,    

  222228.     1754,  281,   3578,  57,    4634,  3322,  54,    50,    54,    50,    

  222229.     54,    50,    54,    50,    54,    50,    54,    50,    54,    50,    

  222230.     975,   1434,  185,   54,    50,    1017,  54,    50,    54,    50,    

  222231.     54,    50,    54,    50,    54,    50,    537,   8218,  4217,  54,    

  222232.     50,    54,    50,    54,    50,    54,    50,    54,    50,    54,    

  222233.     50,    54,    50,    54,    50,    54,    50,    54,    50,    54,    

  222234.     50,    2041,  54,    50,    54,    50,    1049,  54,    50,    8281,  

  222235.     1562,  697,   90,    217,   346,   1513,  1509,  126,   73,    69,    

  222236.     254,   105,   37,    94,    37,    94,    165,   70,    105,   37,    

  222237.     3166,  37,    218,   158,   108,   94,    149,   47,    85,    1221,  

  222238.     37,    37,    1799,  38,    53,    44,    743,   231,   231,   231,   

  222239.     231,   231,   231,   231,   231,   1036,  85,    52,    51,    52,    

  222240.     51,    117,   52,    51,    53,    52,    51,    309,   49,    85,    

  222241.     49,    53,    52,    51,    85,    52,    51,    54,    50,    54,    

  222242.     50,    54,    50,    54,    50,    181,   38,    341,   81,    858,   

  222243.     2874,  6874,  410,   61,    117,   58,    38,    39,    46,    54,    

  222244.     50,    54,    50,    54,    50,    54,    50,    54,    50,    90,    

  222245.     54,    50,    54,    50,    54,    50,    54,    50,    49,    54,    

  222246.     82,    58,    302,   140,   74,    49,    166,   90,    110,   38,    

  222247.     39,    53,    90,    2759,  76,    88,    70,    39,    49,    2887,  

  222248.     53,    102,   39,    1319,  3015,  90,    143,   346,   871,   1178,  

  222249.     519,   1018,  335,   986,   271,   58,    495,   1050,  335,   1274,  

  222250.     495,   2042,  8218,  39,    39,    2074,  39,    39,    679,   38,    

  222251.     36583, 1786,  1287,  198,   85,    8583,  38,    117,   519,   333,   

  222252.     71,    1502,  39,    44,    107,   53,    332,   53,    38,    798,   

  222253.     44,    2247,  334,   76,    213,   760,   294,   88,    478,   69,    

  222254.     2014,  38,    261,   190,   350,   38,    88,    158,   158,   382,   

  222255.     70,    37,    231,   44,    103,   44,    135,   44,    743,   74,    

  222256.     76,    42,    154,   207,   90,    55,    58,    1671,  149,   74,    

  222257.     1607,  522,   44,    85,    333,   588,   199,   117,   39,    333,   

  222258.     903,   268,   85,    743,   364,   74,    53,    935,   108,   42,    

  222259.     1511,  44,    74,    140,   74,    44,    138,   437,   38,    333,   

  222260.     85,    1319,  204,   74,    76,    74,    76,    103,   44,    263,   

  222261.     44,    42,    333,   149,   519,   38,    199,   122,   39,    42,    

  222262.     1543,  44,    39,    108,   71,    76,    167,   76,    39,    44,    

  222263.     39,    71,    38,    85,    359,   42,    76,    74,    85,    39,    

  222264.     70,    42,    44,    199,   199,   199,   231,   231,   1127,  74,    

  222265.     44,    74,    44,    74,    53,    42,    44,    333,   39,    39,    

  222266.     743,   1575,  36,    68,    68,    36,    63,    63,    11719, 3399,  

  222267.     229,   165,   39,    44,    327,   57,    423,   167,   39,    71,    

  222268.     71,    3463,  536,   11623, 54,    50,    2055,  1735,  391,   55,    

  222269.     58,    524,   245,   54,    50,    53,    236,   53,    81,    80,    

  222270.     54,    50,    54,    50,    54,    50,    54,    50,    54,    50,    

  222271.     54,    50,    54,    50,    54,    50,    85,    54,    50,    149,   

  222272.     112,   117,   149,   49,    54,    50,    54,    50,    54,    50,    

  222273.     117,   57,    49,    121,   53,    55,    85,    167,   4327,  34,    

  222274.     117,   55,    117,   54,    50,    53,    57,    53,    49,    85,    

  222275.     333,   85,    121,   85,    841,   54,    53,    50,    56,    48,    

  222276.     56,    837,   54,    57,    50,    57,    54,    50,    53,    54,    

  222277.     50,    85,    327,   38,    1447,  70,    999,   199,   199,   199,   

  222278.     103,   87,    57,    56,    58,    87,    58,    153,   90,    98,    

  222279.     90,    391,   839,   615,   71,    487,   455,   3943,  117,   1455,  

  222280.     314,   1710,  143,   570,   47,    410,   1466,  44,    935,   1575,  

  222281.     999,   143,   551,   46,    263,   46,    967,   53,    1159,  263,   

  222282.     53,    174,   1289,  1285,  2503,  333,   199,   39,    1415,  71,    

  222283.     39,    743,   53,    271,   711,   207,   53,    839,   53,    1799,  

  222284.     71,    39,    108,   76,    140,   135,   103,   871,   108,   44,    

  222285.     271,   309,   935,   79,    53,    1735,  245,   711,   271,   615,   

  222286.     271,   2343,  1007,  42,    44,    42,    1703,  492,   245,   655,   

  222287.     333,   76,    42,    1447,  106,   140,   74,    76,    85,    34,    

  222288.     149,   807,   333,   108,   1159,  172,   42,    268,   333,   149,   

  222289.     76,    42,    1543,  106,   300,   74,    135,   149,   333,   1383,  

  222290.     44,    42,    44,    74,    204,   42,    44,    333,   28135, 3182,  

  222291.     149,   34279, 18215, 2215,  39,    1482,  140,   422,   71,    7898,  

  222292.     1274,  1946,  74,    108,   122,   202,   258,   268,   90,    236,   

  222293.     986,   140,   1562,  2138,  108,   58,    2810,  591,   841,   837,   

  222294.     841,   229,   581,   841,   837,   41,    73,    41,    73,    137,   

  222295.     265,   133,   37,    229,   357,   841,   837,   73,    137,   265,   

  222296.     233,   837,   73,    137,   169,   41,    233,   837,   841,   837,   

  222297.     841,   837,   841,   837,   841,   837,   841,   837,   841,   901,   

  222298.     809,   57,    805,   57,    197,   809,   57,    805,   57,    197,   

  222299.     809,   57,    805,   57,    197,   809,   57,    805,   57,    197,   

  222300.     809,   57,    805,   57,    197,   94,    1613,  135,   871,   71,    

  222301.     39,    39,    327,   135,   39,    39,    39,    39,    39,    39,    

  222302.     103,   71,    39,    39,    39,    39,    39,    39,    71,    39,    

  222303.     135,   231,   135,   135,   39,    327,   551,   103,   167,   551,   

  222304.     89,    1434,  3226,  506,   474,   506,   506,   367,   1018,  1946,  

  222305.     1402,  954,   1402,  314,   90,    1082,  218,   2266,  666,   1210,  

  222306.     186,   570,   2042,  58,    5850,  154,   2010,  154,   794,   2266,  

  222307.     378,   2266,  3738,  39,    39,    39,    39,    39,    39,    17351, 

  222308.     34,    3074,  7692,  63,    63,    

  222309.   };

  222310. 

  222311. static int sqlite3Fts5UnicodeCategory(u32 iCode) { 

  222312.   int iRes = -1;

  222313.   int iHi;

  222314.   int iLo;

  222315.   int ret;

  222316.   u16 iKey;

  222317. 

  222318.   if( iCode>=(1<<20) ){

  222319.     return 0;

  222320.   }

  222321.   iLo = aFts5UnicodeBlock[(iCode>>16)];

  222322.   iHi = aFts5UnicodeBlock[1+(iCode>>16)];

  222323.   iKey = (iCode & 0xFFFF);

  222324.   while( iHi>iLo ){

  222325.     int iTest = (iHi + iLo) / 2;

  222326.     assert( iTest>=iLo && iTest<iHi );

  222327.     if( iKey>=aFts5UnicodeMap[iTest] ){

  222328.       iRes = iTest;

  222329.       iLo = iTest+1;

  222330.     }else{

  222331.       iHi = iTest;

  222332.     }

  222333.   }

  222334. 

  222335.   if( iRes<0 ) return 0;

  222336.   if( iKey>=(aFts5UnicodeMap[iRes]+(aFts5UnicodeData[iRes]>>5)) ) return 0;

  222337.   ret = aFts5UnicodeData[iRes] & 0x1F;

  222338.   if( ret!=30 ) return ret;

  222339.   return ((iKey - aFts5UnicodeMap[iRes]) & 0x01) ? 5 : 9;

  222340. }

  222341. 

  222342. static void sqlite3Fts5UnicodeAscii(u8 *aArray, u8 *aAscii){

  222343.   int i = 0;

  222344.   int iTbl = 0;

  222345.   while( i<128 ){

  222346.     int bToken = aArray[ aFts5UnicodeData[iTbl] & 0x1F ];

  222347.     int n = (aFts5UnicodeData[iTbl] >> 5) + i;

  222348.     for(; i<128 && i<n; i++){

  222349.       aAscii[i] = (u8)bToken;

  222350.     }

  222351.     iTbl++;

  222352.   }

  222353. }

  222354. 

  222355. /*

  222356. ** 2015 May 30

  222357. **

  222358. ** The author disclaims copyright to this source code.  In place of

  222359. ** a legal notice, here is a blessing:

  222360. **

  222361. **    May you do good and not evil.

  222362. **    May you find forgiveness for yourself and forgive others.

  222363. **    May you share freely, never taking more than you give.

  222364. **

  222365. ******************************************************************************

  222366. **

  222367. ** Routines for varint serialization and deserialization.

  222368. */

  222369. 

  222370. 

  222371. /* #include "fts5Int.h" */

  222372. 

  222373. /*

  222374. ** This is a copy of the sqlite3GetVarint32() routine from the SQLite core.

  222375. ** Except, this version does handle the single byte case that the core

  222376. ** version depends on being handled before its function is called.

  222377. */

  222378. static int sqlite3Fts5GetVarint32(const unsigned char *p, u32 *v){

  222379.   u32 a,b;

  222380. 

  222381.   /* The 1-byte case. Overwhelmingly the most common. */

  222382.   a = *p;

  222383.   /* a: p0 (unmasked) */

  222384.   if (!(a&0x80))

  222385.   {

  222386.     /* Values between 0 and 127 */

  222387.     *v = a;

  222388.     return 1;

  222389.   }

  222390. 

  222391.   /* The 2-byte case */

  222392.   p++;

  222393.   b = *p;

  222394.   /* b: p1 (unmasked) */

  222395.   if (!(b&0x80))

  222396.   {

  222397.     /* Values between 128 and 16383 */

  222398.     a &= 0x7f;

  222399.     a = a<<7;

  222400.     *v = a | b;

  222401.     return 2;

  222402.   }

  222403. 

  222404.   /* The 3-byte case */

  222405.   p++;

  222406.   a = a<<14;

  222407.   a |= *p;

  222408.   /* a: p0<<14 | p2 (unmasked) */

  222409.   if (!(a&0x80))

  222410.   {

  222411.     /* Values between 16384 and 2097151 */

  222412.     a &= (0x7f<<14)|(0x7f);

  222413.     b &= 0x7f;

  222414.     b = b<<7;

  222415.     *v = a | b;

  222416.     return 3;

  222417.   }

  222418. 

  222419.   /* A 32-bit varint is used to store size information in btrees.

  222420.   ** Objects are rarely larger than 2MiB limit of a 3-byte varint.

  222421.   ** A 3-byte varint is sufficient, for example, to record the size

  222422.   ** of a 1048569-byte BLOB or string.

  222423.   **

  222424.   ** We only unroll the first 1-, 2-, and 3- byte cases.  The very

  222425.   ** rare larger cases can be handled by the slower 64-bit varint

  222426.   ** routine.

  222427.   */

  222428.   {

  222429.     u64 v64;

  222430.     u8 n;

  222431.     p -= 2;

  222432.     n = sqlite3Fts5GetVarint(p, &v64);

  222433.     *v = ((u32)v64) & 0x7FFFFFFF;

  222434.     assert( n>3 && n<=9 );

  222435.     return n;

  222436.   }

  222437. }

  222438. 

  222439. 

  222440. /*

  222441. ** Bitmasks used by sqlite3GetVarint().  These precomputed constants

  222442. ** are defined here rather than simply putting the constant expressions

  222443. ** inline in order to work around bugs in the RVT compiler.

  222444. **

  222445. ** SLOT_2_0     A mask for  (0x7f<<14) | 0x7f

  222446. **

  222447. ** SLOT_4_2_0   A mask for  (0x7f<<28) | SLOT_2_0

  222448. */

  222449. #define SLOT_2_0     0x001fc07f

  222450. #define SLOT_4_2_0   0xf01fc07f

  222451. 

  222452. /*

  222453. ** Read a 64-bit variable-length integer from memory starting at p[0].

  222454. ** Return the number of bytes read.  The value is stored in *v.

  222455. */

  222456. static u8 sqlite3Fts5GetVarint(const unsigned char *p, u64 *v){

  222457.   u32 a,b,s;

  222458. 

  222459.   a = *p;

  222460.   /* a: p0 (unmasked) */

  222461.   if (!(a&0x80))

  222462.   {

  222463.     *v = a;

  222464.     return 1;

  222465.   }

  222466. 

  222467.   p++;

  222468.   b = *p;

  222469.   /* b: p1 (unmasked) */

  222470.   if (!(b&0x80))

  222471.   {

  222472.     a &= 0x7f;

  222473.     a = a<<7;

  222474.     a |= b;

  222475.     *v = a;

  222476.     return 2;

  222477.   }

  222478. 

  222479.   /* Verify that constants are precomputed correctly */

  222480.   assert( SLOT_2_0 == ((0x7f<<14) | (0x7f)) );

  222481.   assert( SLOT_4_2_0 == ((0xfU<<28) | (0x7f<<14) | (0x7f)) );

  222482. 

  222483.   p++;

  222484.   a = a<<14;

  222485.   a |= *p;

  222486.   /* a: p0<<14 | p2 (unmasked) */

  222487.   if (!(a&0x80))

  222488.   {

  222489.     a &= SLOT_2_0;

  222490.     b &= 0x7f;

  222491.     b = b<<7;

  222492.     a |= b;

  222493.     *v = a;

  222494.     return 3;

  222495.   }

  222496. 

  222497.   /* CSE1 from below */

  222498.   a &= SLOT_2_0;

  222499.   p++;

  222500.   b = b<<14;

  222501.   b |= *p;

  222502.   /* b: p1<<14 | p3 (unmasked) */

  222503.   if (!(b&0x80))

  222504.   {

  222505.     b &= SLOT_2_0;

  222506.     /* moved CSE1 up */

  222507.     /* a &= (0x7f<<14)|(0x7f); */

  222508.     a = a<<7;

  222509.     a |= b;

  222510.     *v = a;

  222511.     return 4;

  222512.   }

  222513. 

  222514.   /* a: p0<<14 | p2 (masked) */

  222515.   /* b: p1<<14 | p3 (unmasked) */

  222516.   /* 1:save off p0<<21 | p1<<14 | p2<<7 | p3 (masked) */

  222517.   /* moved CSE1 up */

  222518.   /* a &= (0x7f<<14)|(0x7f); */

  222519.   b &= SLOT_2_0;

  222520.   s = a;

  222521.   /* s: p0<<14 | p2 (masked) */

  222522. 

  222523.   p++;

  222524.   a = a<<14;

  222525.   a |= *p;

  222526.   /* a: p0<<28 | p2<<14 | p4 (unmasked) */

  222527.   if (!(a&0x80))

  222528.   {

  222529.     /* we can skip these cause they were (effectively) done above in calc'ing s */

  222530.     /* a &= (0x7f<<28)|(0x7f<<14)|(0x7f); */

  222531.     /* b &= (0x7f<<14)|(0x7f); */

  222532.     b = b<<7;

  222533.     a |= b;

  222534.     s = s>>18;

  222535.     *v = ((u64)s)<<32 | a;

  222536.     return 5;

  222537.   }

  222538. 

  222539.   /* 2:save off p0<<21 | p1<<14 | p2<<7 | p3 (masked) */

  222540.   s = s<<7;

  222541.   s |= b;

  222542.   /* s: p0<<21 | p1<<14 | p2<<7 | p3 (masked) */

  222543. 

  222544.   p++;

  222545.   b = b<<14;

  222546.   b |= *p;

  222547.   /* b: p1<<28 | p3<<14 | p5 (unmasked) */

  222548.   if (!(b&0x80))

  222549.   {

  222550.     /* we can skip this cause it was (effectively) done above in calc'ing s */

  222551.     /* b &= (0x7f<<28)|(0x7f<<14)|(0x7f); */

  222552.     a &= SLOT_2_0;

  222553.     a = a<<7;

  222554.     a |= b;

  222555.     s = s>>18;

  222556.     *v = ((u64)s)<<32 | a;

  222557.     return 6;

  222558.   }

  222559. 

  222560.   p++;

  222561.   a = a<<14;

  222562.   a |= *p;

  222563.   /* a: p2<<28 | p4<<14 | p6 (unmasked) */

  222564.   if (!(a&0x80))

  222565.   {

  222566.     a &= SLOT_4_2_0;

  222567.     b &= SLOT_2_0;

  222568.     b = b<<7;

  222569.     a |= b;

  222570.     s = s>>11;

  222571.     *v = ((u64)s)<<32 | a;

  222572.     return 7;

  222573.   }

  222574. 

  222575.   /* CSE2 from below */

  222576.   a &= SLOT_2_0;

  222577.   p++;

  222578.   b = b<<14;

  222579.   b |= *p;

  222580.   /* b: p3<<28 | p5<<14 | p7 (unmasked) */

  222581.   if (!(b&0x80))

  222582.   {

  222583.     b &= SLOT_4_2_0;

  222584.     /* moved CSE2 up */

  222585.     /* a &= (0x7f<<14)|(0x7f); */

  222586.     a = a<<7;

  222587.     a |= b;

  222588.     s = s>>4;

  222589.     *v = ((u64)s)<<32 | a;

  222590.     return 8;

  222591.   }

  222592. 

  222593.   p++;

  222594.   a = a<<15;

  222595.   a |= *p;

  222596.   /* a: p4<<29 | p6<<15 | p8 (unmasked) */

  222597. 

  222598.   /* moved CSE2 up */

  222599.   /* a &= (0x7f<<29)|(0x7f<<15)|(0xff); */

  222600.   b &= SLOT_2_0;

  222601.   b = b<<8;

  222602.   a |= b;

  222603. 

  222604.   s = s<<4;

  222605.   b = p[-4];

  222606.   b &= 0x7f;

  222607.   b = b>>3;

  222608.   s |= b;

  222609. 

  222610.   *v = ((u64)s)<<32 | a;

  222611. 

  222612.   return 9;

  222613. }

  222614. 

  222615. /*

  222616. ** The variable-length integer encoding is as follows:

  222617. **

  222618. ** KEY:

  222619. **         A = 0xxxxxxx    7 bits of data and one flag bit

  222620. **         B = 1xxxxxxx    7 bits of data and one flag bit

  222621. **         C = xxxxxxxx    8 bits of data

  222622. **

  222623. **  7 bits - A

  222624. ** 14 bits - BA

  222625. ** 21 bits - BBA

  222626. ** 28 bits - BBBA

  222627. ** 35 bits - BBBBA

  222628. ** 42 bits - BBBBBA

  222629. ** 49 bits - BBBBBBA

  222630. ** 56 bits - BBBBBBBA

  222631. ** 64 bits - BBBBBBBBC

  222632. */

  222633. 

  222634. #ifdef SQLITE_NOINLINE

  222635. # define FTS5_NOINLINE SQLITE_NOINLINE

  222636. #else

  222637. # define FTS5_NOINLINE

  222638. #endif

  222639. 

  222640. /*

  222641. ** Write a 64-bit variable-length integer to memory starting at p[0].

  222642. ** The length of data write will be between 1 and 9 bytes.  The number

  222643. ** of bytes written is returned.

  222644. **

  222645. ** A variable-length integer consists of the lower 7 bits of each byte

  222646. ** for all bytes that have the 8th bit set and one byte with the 8th

  222647. ** bit clear.  Except, if we get to the 9th byte, it stores the full

  222648. ** 8 bits and is the last byte.

  222649. */

  222650. static int FTS5_NOINLINE fts5PutVarint64(unsigned char *p, u64 v){

  222651.   int i, j, n;

  222652.   u8 buf[10];

  222653.   if( v & (((u64)0xff000000)<<32) ){

  222654.     p[8] = (u8)v;

  222655.     v >>= 8;

  222656.     for(i=7; i>=0; i--){

  222657.       p[i] = (u8)((v & 0x7f) | 0x80);

  222658.       v >>= 7;

  222659.     }

  222660.     return 9;

  222661.   }    

  222662.   n = 0;

  222663.   do{

  222664.     buf[n++] = (u8)((v & 0x7f) | 0x80);

  222665.     v >>= 7;

  222666.   }while( v!=0 );

  222667.   buf[0] &= 0x7f;

  222668.   assert( n<=9 );

  222669.   for(i=0, j=n-1; j>=0; j--, i++){

  222670.     p[i] = buf[j];

  222671.   }

  222672.   return n;

  222673. }

  222674. 

  222675. static int sqlite3Fts5PutVarint(unsigned char *p, u64 v){

  222676.   if( v<=0x7f ){

  222677.     p[0] = v&0x7f;

  222678.     return 1;

  222679.   }

  222680.   if( v<=0x3fff ){

  222681.     p[0] = ((v>>7)&0x7f)|0x80;

  222682.     p[1] = v&0x7f;

  222683.     return 2;

  222684.   }

  222685.   return fts5PutVarint64(p,v);

  222686. }

  222687. 

  222688. 

  222689. static int sqlite3Fts5GetVarintLen(u32 iVal){

  222690. #if 0

  222691.   if( iVal<(1 << 7 ) ) return 1;

  222692. #endif

  222693.   assert( iVal>=(1 << 7) );

  222694.   if( iVal<(1 << 14) ) return 2;

  222695.   if( iVal<(1 << 21) ) return 3;

  222696.   if( iVal<(1 << 28) ) return 4;

  222697.   return 5;

  222698. }

  222699. 

  222700. /*

  222701. ** 2015 May 08

  222702. **

  222703. ** The author disclaims copyright to this source code.  In place of

  222704. ** a legal notice, here is a blessing:

  222705. **

  222706. **    May you do good and not evil.

  222707. **    May you find forgiveness for yourself and forgive others.

  222708. **    May you share freely, never taking more than you give.

  222709. **

  222710. ******************************************************************************

  222711. **

  222712. ** This is an SQLite virtual table module implementing direct access to an

  222713. ** existing FTS5 index. The module may create several different types of 

  222714. ** tables:

  222715. **

  222716. ** col:

  222717. **     CREATE TABLE vocab(term, col, doc, cnt, PRIMARY KEY(term, col));

  222718. **

  222719. **   One row for each term/column combination. The value of $doc is set to

  222720. **   the number of fts5 rows that contain at least one instance of term

  222721. **   $term within column $col. Field $cnt is set to the total number of 

  222722. **   instances of term $term in column $col (in any row of the fts5 table). 

  222723. **

  222724. ** row:

  222725. **     CREATE TABLE vocab(term, doc, cnt, PRIMARY KEY(term));

  222726. **

  222727. **   One row for each term in the database. The value of $doc is set to

  222728. **   the number of fts5 rows that contain at least one instance of term

  222729. **   $term. Field $cnt is set to the total number of instances of term 

  222730. **   $term in the database.

  222731. **

  222732. ** instance:

  222733. **     CREATE TABLE vocab(term, doc, col, offset, PRIMARY KEY(<all-fields>));

  222734. **

  222735. **   One row for each term instance in the database. 

  222736. */

  222737. 

  222738. 

  222739. /* #include "fts5Int.h" */

  222740. 

  222741. 

  222742. typedef struct Fts5VocabTable Fts5VocabTable;

  222743. typedef struct Fts5VocabCursor Fts5VocabCursor;

  222744. 

  222745. struct Fts5VocabTable {

  222746.   sqlite3_vtab base;

  222747.   char *zFts5Tbl;                 /* Name of fts5 table */

  222748.   char *zFts5Db;                  /* Db containing fts5 table */

  222749.   sqlite3 *db;                    /* Database handle */

  222750.   Fts5Global *pGlobal;            /* FTS5 global object for this database */

  222751.   int eType;                      /* FTS5_VOCAB_COL, ROW or INSTANCE */

  222752. };

  222753. 

  222754. struct Fts5VocabCursor {

  222755.   sqlite3_vtab_cursor base;

  222756.   sqlite3_stmt *pStmt;            /* Statement holding lock on pIndex */

  222757.   Fts5Table *pFts5;               /* Associated FTS5 table */

  222758. 

  222759.   int bEof;                       /* True if this cursor is at EOF */

  222760.   Fts5IndexIter *pIter;           /* Term/rowid iterator object */

  222761. 

  222762.   int nLeTerm;                    /* Size of zLeTerm in bytes */

  222763.   char *zLeTerm;                  /* (term <= $zLeTerm) paramater, or NULL */

  222764. 

  222765.   /* These are used by 'col' tables only */

  222766.   int iCol;

  222767.   i64 *aCnt;

  222768.   i64 *aDoc;

  222769. 

  222770.   /* Output values used by all tables. */

  222771.   i64 rowid;                      /* This table's current rowid value */

  222772.   Fts5Buffer term;                /* Current value of 'term' column */

  222773. 

  222774.   /* Output values Used by 'instance' tables only */

  222775.   i64 iInstPos;

  222776.   int iInstOff;

  222777. };

  222778. 

  222779. #define FTS5_VOCAB_COL      0

  222780. #define FTS5_VOCAB_ROW      1

  222781. #define FTS5_VOCAB_INSTANCE 2

  222782. 

  222783. #define FTS5_VOCAB_COL_SCHEMA  "term, col, doc, cnt"

  222784. #define FTS5_VOCAB_ROW_SCHEMA  "term, doc, cnt"

  222785. #define FTS5_VOCAB_INST_SCHEMA "term, doc, col, offset"

  222786. 

  222787. /*

  222788. ** Bits for the mask used as the idxNum value by xBestIndex/xFilter.

  222789. */

  222790. #define FTS5_VOCAB_TERM_EQ 0x01

  222791. #define FTS5_VOCAB_TERM_GE 0x02

  222792. #define FTS5_VOCAB_TERM_LE 0x04

  222793. 

  222794. 

  222795. /*

  222796. ** Translate a string containing an fts5vocab table type to an 

  222797. ** FTS5_VOCAB_XXX constant. If successful, set *peType to the output

  222798. ** value and return SQLITE_OK. Otherwise, set *pzErr to an error message

  222799. ** and return SQLITE_ERROR.

  222800. */

  222801. static int fts5VocabTableType(const char *zType, char **pzErr, int *peType){

  222802.   int rc = SQLITE_OK;

  222803.   char *zCopy = sqlite3Fts5Strndup(&rc, zType, -1);

  222804.   if( rc==SQLITE_OK ){

  222805.     sqlite3Fts5Dequote(zCopy);

  222806.     if( sqlite3_stricmp(zCopy, "col")==0 ){

  222807.       *peType = FTS5_VOCAB_COL;

  222808.     }else

  222809. 

  222810.     if( sqlite3_stricmp(zCopy, "row")==0 ){

  222811.       *peType = FTS5_VOCAB_ROW;

  222812.     }else

  222813.     if( sqlite3_stricmp(zCopy, "instance")==0 ){

  222814.       *peType = FTS5_VOCAB_INSTANCE;

  222815.     }else

  222816.     {

  222817.       *pzErr = sqlite3_mprintf("fts5vocab: unknown table type: %Q", zCopy);

  222818.       rc = SQLITE_ERROR;

  222819.     }

  222820.     sqlite3_free(zCopy);

  222821.   }

  222822. 

  222823.   return rc;

  222824. }

  222825. 

  222826. 

  222827. /*

  222828. ** The xDisconnect() virtual table method.

  222829. */

  222830. static int fts5VocabDisconnectMethod(sqlite3_vtab *pVtab){

  222831.   Fts5VocabTable *pTab = (Fts5VocabTable*)pVtab;

  222832.   sqlite3_free(pTab);

  222833.   return SQLITE_OK;

  222834. }

  222835. 

  222836. /*

  222837. ** The xDestroy() virtual table method.

  222838. */

  222839. static int fts5VocabDestroyMethod(sqlite3_vtab *pVtab){

  222840.   Fts5VocabTable *pTab = (Fts5VocabTable*)pVtab;

  222841.   sqlite3_free(pTab);

  222842.   return SQLITE_OK;

  222843. }

  222844. 

  222845. /*

  222846. ** This function is the implementation of both the xConnect and xCreate

  222847. ** methods of the FTS3 virtual table.

  222848. **

  222849. ** The argv[] array contains the following:

  222850. **

  222851. **   argv[0]   -> module name  ("fts5vocab")

  222852. **   argv[1]   -> database name

  222853. **   argv[2]   -> table name

  222854. **

  222855. ** then:

  222856. **

  222857. **   argv[3]   -> name of fts5 table

  222858. **   argv[4]   -> type of fts5vocab table

  222859. **

  222860. ** or, for tables in the TEMP schema only.

  222861. **

  222862. **   argv[3]   -> name of fts5 tables database

  222863. **   argv[4]   -> name of fts5 table

  222864. **   argv[5]   -> type of fts5vocab table

  222865. */

  222866. static int fts5VocabInitVtab(

  222867.   sqlite3 *db,                    /* The SQLite database connection */

  222868.   void *pAux,                     /* Pointer to Fts5Global object */

  222869.   int argc,                       /* Number of elements in argv array */

  222870.   const char * const *argv,       /* xCreate/xConnect argument array */

  222871.   sqlite3_vtab **ppVTab,          /* Write the resulting vtab structure here */

  222872.   char **pzErr                    /* Write any error message here */

  222873. ){

  222874.   const char *azSchema[] = { 

  222875.     "CREATE TABlE vocab(" FTS5_VOCAB_COL_SCHEMA  ")", 

  222876.     "CREATE TABlE vocab(" FTS5_VOCAB_ROW_SCHEMA  ")",

  222877.     "CREATE TABlE vocab(" FTS5_VOCAB_INST_SCHEMA ")"

  222878.   };

  222879. 

  222880.   Fts5VocabTable *pRet = 0;

  222881.   int rc = SQLITE_OK;             /* Return code */

  222882.   int bDb;

  222883. 

  222884.   bDb = (argc==6 && strlen(argv[1])==4 && memcmp("temp", argv[1], 4)==0);

  222885. 

  222886.   if( argc!=5 && bDb==0 ){

  222887.     *pzErr = sqlite3_mprintf("wrong number of vtable arguments");

  222888.     rc = SQLITE_ERROR;

  222889.   }else{

  222890.     int nByte;                      /* Bytes of space to allocate */

  222891.     const char *zDb = bDb ? argv[3] : argv[1];

  222892.     const char *zTab = bDb ? argv[4] : argv[3];

  222893.     const char *zType = bDb ? argv[5] : argv[4];

  222894.     int nDb = (int)strlen(zDb)+1; 

  222895.     int nTab = (int)strlen(zTab)+1;

  222896.     int eType = 0;

  222897.     

  222898.     rc = fts5VocabTableType(zType, pzErr, &eType);

  222899.     if( rc==SQLITE_OK ){

  222900.       assert( eType>=0 && eType<ArraySize(azSchema) );

  222901.       rc = sqlite3_declare_vtab(db, azSchema[eType]);

  222902.     }

  222903. 

  222904.     nByte = sizeof(Fts5VocabTable) + nDb + nTab;

  222905.     pRet = sqlite3Fts5MallocZero(&rc, nByte);

  222906.     if( pRet ){

  222907.       pRet->pGlobal = (Fts5Global*)pAux;

  222908.       pRet->eType = eType;

  222909.       pRet->db = db;

  222910.       pRet->zFts5Tbl = (char*)&pRet[1];

  222911.       pRet->zFts5Db = &pRet->zFts5Tbl[nTab];

  222912.       memcpy(pRet->zFts5Tbl, zTab, nTab);

  222913.       memcpy(pRet->zFts5Db, zDb, nDb);

  222914.       sqlite3Fts5Dequote(pRet->zFts5Tbl);

  222915.       sqlite3Fts5Dequote(pRet->zFts5Db);

  222916.     }

  222917.   }

  222918. 

  222919.   *ppVTab = (sqlite3_vtab*)pRet;

  222920.   return rc;

  222921. }

  222922. 

  222923. 

  222924. /*

  222925. ** The xConnect() and xCreate() methods for the virtual table. All the

  222926. ** work is done in function fts5VocabInitVtab().

  222927. */

  222928. static int fts5VocabConnectMethod(

  222929.   sqlite3 *db,                    /* Database connection */

  222930.   void *pAux,                     /* Pointer to tokenizer hash table */

  222931.   int argc,                       /* Number of elements in argv array */

  222932.   const char * const *argv,       /* xCreate/xConnect argument array */

  222933.   sqlite3_vtab **ppVtab,          /* OUT: New sqlite3_vtab object */

  222934.   char **pzErr                    /* OUT: sqlite3_malloc'd error message */

  222935. ){

  222936.   return fts5VocabInitVtab(db, pAux, argc, argv, ppVtab, pzErr);

  222937. }

  222938. static int fts5VocabCreateMethod(

  222939.   sqlite3 *db,                    /* Database connection */

  222940.   void *pAux,                     /* Pointer to tokenizer hash table */

  222941.   int argc,                       /* Number of elements in argv array */

  222942.   const char * const *argv,       /* xCreate/xConnect argument array */

  222943.   sqlite3_vtab **ppVtab,          /* OUT: New sqlite3_vtab object */

  222944.   char **pzErr                    /* OUT: sqlite3_malloc'd error message */

  222945. ){

  222946.   return fts5VocabInitVtab(db, pAux, argc, argv, ppVtab, pzErr);

  222947. }

  222948. 

  222949. /* 

  222950. ** Implementation of the xBestIndex method.

  222951. **

  222952. ** Only constraints of the form:

  222953. **

  222954. **     term <= ?

  222955. **     term == ?

  222956. **     term >= ?

  222957. **

  222958. ** are interpreted. Less-than and less-than-or-equal are treated 

  222959. ** identically, as are greater-than and greater-than-or-equal.

  222960. */

  222961. static int fts5VocabBestIndexMethod(

  222962.   sqlite3_vtab *pUnused,

  222963.   sqlite3_index_info *pInfo

  222964. ){

  222965.   int i;

  222966.   int iTermEq = -1;

  222967.   int iTermGe = -1;

  222968.   int iTermLe = -1;

  222969.   int idxNum = 0;

  222970.   int nArg = 0;

  222971. 

  222972.   UNUSED_PARAM(pUnused);

  222973. 

  222974.   for(i=0; i<pInfo->nConstraint; i++){

  222975.     struct sqlite3_index_constraint *p = &pInfo->aConstraint[i];

  222976.     if( p->usable==0 ) continue;

  222977.     if( p->iColumn==0 ){          /* term column */

  222978.       if( p->op==SQLITE_INDEX_CONSTRAINT_EQ ) iTermEq = i;

  222979.       if( p->op==SQLITE_INDEX_CONSTRAINT_LE ) iTermLe = i;

  222980.       if( p->op==SQLITE_INDEX_CONSTRAINT_LT ) iTermLe = i;

  222981.       if( p->op==SQLITE_INDEX_CONSTRAINT_GE ) iTermGe = i;

  222982.       if( p->op==SQLITE_INDEX_CONSTRAINT_GT ) iTermGe = i;

  222983.     }

  222984.   }

  222985. 

  222986.   if( iTermEq>=0 ){

  222987.     idxNum |= FTS5_VOCAB_TERM_EQ;

  222988.     pInfo->aConstraintUsage[iTermEq].argvIndex = ++nArg;

  222989.     pInfo->estimatedCost = 100;

  222990.   }else{

  222991.     pInfo->estimatedCost = 1000000;

  222992.     if( iTermGe>=0 ){

  222993.       idxNum |= FTS5_VOCAB_TERM_GE;

  222994.       pInfo->aConstraintUsage[iTermGe].argvIndex = ++nArg;

  222995.       pInfo->estimatedCost = pInfo->estimatedCost / 2;

  222996.     }

  222997.     if( iTermLe>=0 ){

  222998.       idxNum |= FTS5_VOCAB_TERM_LE;

  222999.       pInfo->aConstraintUsage[iTermLe].argvIndex = ++nArg;

  223000.       pInfo->estimatedCost = pInfo->estimatedCost / 2;

  223001.     }

  223002.   }

  223003. 

  223004.   /* This virtual table always delivers results in ascending order of

  223005.   ** the "term" column (column 0). So if the user has requested this

  223006.   ** specifically - "ORDER BY term" or "ORDER BY term ASC" - set the

  223007.   ** sqlite3_index_info.orderByConsumed flag to tell the core the results

  223008.   ** are already in sorted order.  */

  223009.   if( pInfo->nOrderBy==1 

  223010.    && pInfo->aOrderBy[0].iColumn==0 

  223011.    && pInfo->aOrderBy[0].desc==0

  223012.   ){

  223013.     pInfo->orderByConsumed = 1;

  223014.   }

  223015. 

  223016.   pInfo->idxNum = idxNum;

  223017.   return SQLITE_OK;

  223018. }

  223019. 

  223020. /*

  223021. ** Implementation of xOpen method.

  223022. */

  223023. static int fts5VocabOpenMethod(

  223024.   sqlite3_vtab *pVTab, 

  223025.   sqlite3_vtab_cursor **ppCsr

  223026. ){

  223027.   Fts5VocabTable *pTab = (Fts5VocabTable*)pVTab;

  223028.   Fts5Table *pFts5 = 0;

  223029.   Fts5VocabCursor *pCsr = 0;

  223030.   int rc = SQLITE_OK;

  223031.   sqlite3_stmt *pStmt = 0;

  223032.   char *zSql = 0;

  223033. 

  223034.   zSql = sqlite3Fts5Mprintf(&rc,

  223035.       "SELECT t.%Q FROM %Q.%Q AS t WHERE t.%Q MATCH '*id'",

  223036.       pTab->zFts5Tbl, pTab->zFts5Db, pTab->zFts5Tbl, pTab->zFts5Tbl

  223037.   );

  223038.   if( zSql ){

  223039.     rc = sqlite3_prepare_v2(pTab->db, zSql, -1, &pStmt, 0);

  223040.   }

  223041.   sqlite3_free(zSql);

  223042.   assert( rc==SQLITE_OK || pStmt==0 );

  223043.   if( rc==SQLITE_ERROR ) rc = SQLITE_OK;

  223044. 

  223045.   if( pStmt && sqlite3_step(pStmt)==SQLITE_ROW ){

  223046.     i64 iId = sqlite3_column_int64(pStmt, 0);

  223047.     pFts5 = sqlite3Fts5TableFromCsrid(pTab->pGlobal, iId);

  223048.   }

  223049. 

  223050.   if( rc==SQLITE_OK ){

  223051.     if( pFts5==0 ){

  223052.       rc = sqlite3_finalize(pStmt);

  223053.       pStmt = 0;

  223054.       if( rc==SQLITE_OK ){

  223055.         pVTab->zErrMsg = sqlite3_mprintf(

  223056.             "no such fts5 table: %s.%s", pTab->zFts5Db, pTab->zFts5Tbl

  223057.             );

  223058.         rc = SQLITE_ERROR;

  223059.       }

  223060.     }else{

  223061.       rc = sqlite3Fts5FlushToDisk(pFts5);

  223062.     }

  223063.   }

  223064. 

  223065.   if( rc==SQLITE_OK ){

  223066.     int nByte = pFts5->pConfig->nCol * sizeof(i64)*2 + sizeof(Fts5VocabCursor);

  223067.     pCsr = (Fts5VocabCursor*)sqlite3Fts5MallocZero(&rc, nByte);

  223068.   }

  223069. 

  223070.   if( pCsr ){

  223071.     pCsr->pFts5 = pFts5;

  223072.     pCsr->pStmt = pStmt;

  223073.     pCsr->aCnt = (i64*)&pCsr[1];

  223074.     pCsr->aDoc = &pCsr->aCnt[pFts5->pConfig->nCol];

  223075.   }else{

  223076.     sqlite3_finalize(pStmt);

  223077.   }

  223078. 

  223079.   *ppCsr = (sqlite3_vtab_cursor*)pCsr;

  223080.   return rc;

  223081. }

  223082. 

  223083. static void fts5VocabResetCursor(Fts5VocabCursor *pCsr){

  223084.   pCsr->rowid = 0;

  223085.   sqlite3Fts5IterClose(pCsr->pIter);

  223086.   pCsr->pIter = 0;

  223087.   sqlite3_free(pCsr->zLeTerm);

  223088.   pCsr->nLeTerm = -1;

  223089.   pCsr->zLeTerm = 0;

  223090.   pCsr->bEof = 0;

  223091. }

  223092. 

  223093. /*

  223094. ** Close the cursor.  For additional information see the documentation

  223095. ** on the xClose method of the virtual table interface.

  223096. */

  223097. static int fts5VocabCloseMethod(sqlite3_vtab_cursor *pCursor){

  223098.   Fts5VocabCursor *pCsr = (Fts5VocabCursor*)pCursor;

  223099.   fts5VocabResetCursor(pCsr);

  223100.   sqlite3Fts5BufferFree(&pCsr->term);

  223101.   sqlite3_finalize(pCsr->pStmt);

  223102.   sqlite3_free(pCsr);

  223103.   return SQLITE_OK;

  223104. }

  223105. 

  223106. static int fts5VocabInstanceNewTerm(Fts5VocabCursor *pCsr){

  223107.   int rc = SQLITE_OK;

  223108.   

  223109.   if( sqlite3Fts5IterEof(pCsr->pIter) ){

  223110.     pCsr->bEof = 1;

  223111.   }else{

  223112.     const char *zTerm;

  223113.     int nTerm;

  223114.     zTerm = sqlite3Fts5IterTerm(pCsr->pIter, &nTerm);

  223115.     if( pCsr->nLeTerm>=0 ){

  223116.       int nCmp = MIN(nTerm, pCsr->nLeTerm);

  223117.       int bCmp = memcmp(pCsr->zLeTerm, zTerm, nCmp);

  223118.       if( bCmp<0 || (bCmp==0 && pCsr->nLeTerm<nTerm) ){

  223119.         pCsr->bEof = 1;

  223120.       }

  223121.     }

  223122. 

  223123.     sqlite3Fts5BufferSet(&rc, &pCsr->term, nTerm, (const u8*)zTerm);

  223124.   }

  223125.   return rc;

  223126. }

  223127. 

  223128. static int fts5VocabInstanceNext(Fts5VocabCursor *pCsr){

  223129.   int eDetail = pCsr->pFts5->pConfig->eDetail;

  223130.   int rc = SQLITE_OK;

  223131.   Fts5IndexIter *pIter = pCsr->pIter;

  223132.   i64 *pp = &pCsr->iInstPos;

  223133.   int *po = &pCsr->iInstOff;

  223134.   

  223135.   assert( sqlite3Fts5IterEof(pIter)==0 );

  223136.   assert( pCsr->bEof==0 );

  223137.   while( eDetail==FTS5_DETAIL_NONE

  223138.       || sqlite3Fts5PoslistNext64(pIter->pData, pIter->nData, po, pp) 

  223139.   ){

  223140.     pCsr->iInstPos = 0;

  223141.     pCsr->iInstOff = 0;

  223142. 

  223143.     rc = sqlite3Fts5IterNextScan(pCsr->pIter);

  223144.     if( rc==SQLITE_OK ){

  223145.       rc = fts5VocabInstanceNewTerm(pCsr);

  223146.       if( pCsr->bEof || eDetail==FTS5_DETAIL_NONE ) break;

  223147.     }

  223148.     if( rc ){

  223149.       pCsr->bEof = 1;

  223150.       break;

  223151.     }

  223152.   }

  223153. 

  223154.   return rc;

  223155. }

  223156. 

  223157. /*

  223158. ** Advance the cursor to the next row in the table.

  223159. */

  223160. static int fts5VocabNextMethod(sqlite3_vtab_cursor *pCursor){

  223161.   Fts5VocabCursor *pCsr = (Fts5VocabCursor*)pCursor;

  223162.   Fts5VocabTable *pTab = (Fts5VocabTable*)pCursor->pVtab;

  223163.   int rc = SQLITE_OK;

  223164.   int nCol = pCsr->pFts5->pConfig->nCol;

  223165. 

  223166.   pCsr->rowid++;

  223167. 

  223168.   if( pTab->eType==FTS5_VOCAB_INSTANCE ){

  223169.     return fts5VocabInstanceNext(pCsr);

  223170.   }

  223171. 

  223172.   if( pTab->eType==FTS5_VOCAB_COL ){

  223173.     for(pCsr->iCol++; pCsr->iCol<nCol; pCsr->iCol++){

  223174.       if( pCsr->aDoc[pCsr->iCol] ) break;

  223175.     }

  223176.   }

  223177. 

  223178.   if( pTab->eType!=FTS5_VOCAB_COL || pCsr->iCol>=nCol ){

  223179.     if( sqlite3Fts5IterEof(pCsr->pIter) ){

  223180.       pCsr->bEof = 1;

  223181.     }else{

  223182.       const char *zTerm;

  223183.       int nTerm;

  223184. 

  223185.       zTerm = sqlite3Fts5IterTerm(pCsr->pIter, &nTerm);

  223186.       assert( nTerm>=0 );

  223187.       if( pCsr->nLeTerm>=0 ){

  223188.         int nCmp = MIN(nTerm, pCsr->nLeTerm);

  223189.         int bCmp = memcmp(pCsr->zLeTerm, zTerm, nCmp);

  223190.         if( bCmp<0 || (bCmp==0 && pCsr->nLeTerm<nTerm) ){

  223191.           pCsr->bEof = 1;

  223192.           return SQLITE_OK;

  223193.         }

  223194.       }

  223195. 

  223196.       sqlite3Fts5BufferSet(&rc, &pCsr->term, nTerm, (const u8*)zTerm);

  223197.       memset(pCsr->aCnt, 0, nCol * sizeof(i64));

  223198.       memset(pCsr->aDoc, 0, nCol * sizeof(i64));

  223199.       pCsr->iCol = 0;

  223200. 

  223201.       assert( pTab->eType==FTS5_VOCAB_COL || pTab->eType==FTS5_VOCAB_ROW );

  223202.       while( rc==SQLITE_OK ){

  223203.         int eDetail = pCsr->pFts5->pConfig->eDetail;

  223204.         const u8 *pPos; int nPos;   /* Position list */

  223205.         i64 iPos = 0;               /* 64-bit position read from poslist */

  223206.         int iOff = 0;               /* Current offset within position list */

  223207. 

  223208.         pPos = pCsr->pIter->pData;

  223209.         nPos = pCsr->pIter->nData;

  223210. 

  223211.         switch( pTab->eType ){

  223212.           case FTS5_VOCAB_ROW:

  223213.             if( eDetail==FTS5_DETAIL_FULL ){

  223214.               while( 0==sqlite3Fts5PoslistNext64(pPos, nPos, &iOff, &iPos) ){

  223215.                 pCsr->aCnt[0]++;

  223216.               }

  223217.             }

  223218.             pCsr->aDoc[0]++;

  223219.             break;

  223220. 

  223221.           case FTS5_VOCAB_COL:

  223222.             if( eDetail==FTS5_DETAIL_FULL ){

  223223.               int iCol = -1;

  223224.               while( 0==sqlite3Fts5PoslistNext64(pPos, nPos, &iOff, &iPos) ){

  223225.                 int ii = FTS5_POS2COLUMN(iPos);

  223226.                 if( iCol!=ii ){

  223227.                   if( ii>=nCol ){

  223228.                     rc = FTS5_CORRUPT;

  223229.                     break;

  223230.                   }

  223231.                   pCsr->aDoc[ii]++;

  223232.                   iCol = ii;

  223233.                 }

  223234.                 pCsr->aCnt[ii]++;

  223235.               }

  223236.             }else if( eDetail==FTS5_DETAIL_COLUMNS ){

  223237.               while( 0==sqlite3Fts5PoslistNext64(pPos, nPos, &iOff,&iPos) ){

  223238.                 assert_nc( iPos>=0 && iPos<nCol );

  223239.                 if( iPos>=nCol ){

  223240.                   rc = FTS5_CORRUPT;

  223241.                   break;

  223242.                 }

  223243.                 pCsr->aDoc[iPos]++;

  223244.               }

  223245.             }else{

  223246.               assert( eDetail==FTS5_DETAIL_NONE );

  223247.               pCsr->aDoc[0]++;

  223248.             }

  223249.             break;

  223250. 

  223251.           default:

  223252.             assert( pTab->eType==FTS5_VOCAB_INSTANCE );

  223253.             break;

  223254.         }

  223255. 

  223256.         if( rc==SQLITE_OK ){

  223257.           rc = sqlite3Fts5IterNextScan(pCsr->pIter);

  223258.         }

  223259.         if( pTab->eType==FTS5_VOCAB_INSTANCE ) break;

  223260. 

  223261.         if( rc==SQLITE_OK ){

  223262.           zTerm = sqlite3Fts5IterTerm(pCsr->pIter, &nTerm);

  223263.           if( nTerm!=pCsr->term.n 

  223264.           || (nTerm>0 && memcmp(zTerm, pCsr->term.p, nTerm)) 

  223265.           ){

  223266.             break;

  223267.           }

  223268.           if( sqlite3Fts5IterEof(pCsr->pIter) ) break;

  223269.         }

  223270.       }

  223271.     }

  223272.   }

  223273. 

  223274.   if( rc==SQLITE_OK && pCsr->bEof==0 && pTab->eType==FTS5_VOCAB_COL ){

  223275.     for(/* noop */; pCsr->iCol<nCol && pCsr->aDoc[pCsr->iCol]==0; pCsr->iCol++);

  223276.     if( pCsr->iCol==nCol ){

  223277.       rc = FTS5_CORRUPT;

  223278.     }

  223279.   }

  223280.   return rc;

  223281. }

  223282. 

  223283. /*

  223284. ** This is the xFilter implementation for the virtual table.

  223285. */

  223286. static int fts5VocabFilterMethod(

  223287.   sqlite3_vtab_cursor *pCursor,   /* The cursor used for this query */

  223288.   int idxNum,                     /* Strategy index */

  223289.   const char *zUnused,            /* Unused */

  223290.   int nUnused,                    /* Number of elements in apVal */

  223291.   sqlite3_value **apVal           /* Arguments for the indexing scheme */

  223292. ){

  223293.   Fts5VocabTable *pTab = (Fts5VocabTable*)pCursor->pVtab;

  223294.   Fts5VocabCursor *pCsr = (Fts5VocabCursor*)pCursor;

  223295.   int eType = pTab->eType;

  223296.   int rc = SQLITE_OK;

  223297. 

  223298.   int iVal = 0;

  223299.   int f = FTS5INDEX_QUERY_SCAN;

  223300.   const char *zTerm = 0;

  223301.   int nTerm = 0;

  223302. 

  223303.   sqlite3_value *pEq = 0;

  223304.   sqlite3_value *pGe = 0;

  223305.   sqlite3_value *pLe = 0;

  223306. 

  223307.   UNUSED_PARAM2(zUnused, nUnused);

  223308. 

  223309.   fts5VocabResetCursor(pCsr);

  223310.   if( idxNum & FTS5_VOCAB_TERM_EQ ) pEq = apVal[iVal++];

  223311.   if( idxNum & FTS5_VOCAB_TERM_GE ) pGe = apVal[iVal++];

  223312.   if( idxNum & FTS5_VOCAB_TERM_LE ) pLe = apVal[iVal++];

  223313. 

  223314.   if( pEq ){

  223315.     zTerm = (const char *)sqlite3_value_text(pEq);

  223316.     nTerm = sqlite3_value_bytes(pEq);

  223317.     f = 0;

  223318.   }else{

  223319.     if( pGe ){

  223320.       zTerm = (const char *)sqlite3_value_text(pGe);

  223321.       nTerm = sqlite3_value_bytes(pGe);

  223322.     }

  223323.     if( pLe ){

  223324.       const char *zCopy = (const char *)sqlite3_value_text(pLe);

  223325.       if( zCopy==0 ) zCopy = "";

  223326.       pCsr->nLeTerm = sqlite3_value_bytes(pLe);

  223327.       pCsr->zLeTerm = sqlite3_malloc(pCsr->nLeTerm+1);

  223328.       if( pCsr->zLeTerm==0 ){

  223329.         rc = SQLITE_NOMEM;

  223330.       }else{

  223331.         memcpy(pCsr->zLeTerm, zCopy, pCsr->nLeTerm+1);

  223332.       }

  223333.     }

  223334.   }

  223335. 

  223336.   if( rc==SQLITE_OK ){

  223337.     Fts5Index *pIndex = pCsr->pFts5->pIndex;

  223338.     rc = sqlite3Fts5IndexQuery(pIndex, zTerm, nTerm, f, 0, &pCsr->pIter);

  223339.   }

  223340.   if( rc==SQLITE_OK && eType==FTS5_VOCAB_INSTANCE ){

  223341.     rc = fts5VocabInstanceNewTerm(pCsr);

  223342.   }

  223343.   if( rc==SQLITE_OK && !pCsr->bEof 

  223344.    && (eType!=FTS5_VOCAB_INSTANCE 

  223345.     || pCsr->pFts5->pConfig->eDetail!=FTS5_DETAIL_NONE)

  223346.   ){

  223347.     rc = fts5VocabNextMethod(pCursor);

  223348.   }

  223349. 

  223350.   return rc;

  223351. }

  223352. 

  223353. /* 

  223354. ** This is the xEof method of the virtual table. SQLite calls this 

  223355. ** routine to find out if it has reached the end of a result set.

  223356. */

  223357. static int fts5VocabEofMethod(sqlite3_vtab_cursor *pCursor){

  223358.   Fts5VocabCursor *pCsr = (Fts5VocabCursor*)pCursor;

  223359.   return pCsr->bEof;

  223360. }

  223361. 

  223362. static int fts5VocabColumnMethod(

  223363.   sqlite3_vtab_cursor *pCursor,   /* Cursor to retrieve value from */

  223364.   sqlite3_context *pCtx,          /* Context for sqlite3_result_xxx() calls */

  223365.   int iCol                        /* Index of column to read value from */

  223366. ){

  223367.   Fts5VocabCursor *pCsr = (Fts5VocabCursor*)pCursor;

  223368.   int eDetail = pCsr->pFts5->pConfig->eDetail;

  223369.   int eType = ((Fts5VocabTable*)(pCursor->pVtab))->eType;

  223370.   i64 iVal = 0;

  223371. 

  223372.   if( iCol==0 ){

  223373.     sqlite3_result_text(

  223374.         pCtx, (const char*)pCsr->term.p, pCsr->term.n, SQLITE_TRANSIENT

  223375.     );

  223376.   }else if( eType==FTS5_VOCAB_COL ){

  223377.     assert( iCol==1 || iCol==2 || iCol==3 );

  223378.     if( iCol==1 ){

  223379.       if( eDetail!=FTS5_DETAIL_NONE ){

  223380.         const char *z = pCsr->pFts5->pConfig->azCol[pCsr->iCol];

  223381.         sqlite3_result_text(pCtx, z, -1, SQLITE_STATIC);

  223382.       }

  223383.     }else if( iCol==2 ){

  223384.       iVal = pCsr->aDoc[pCsr->iCol];

  223385.     }else{

  223386.       iVal = pCsr->aCnt[pCsr->iCol];

  223387.     }

  223388.   }else if( eType==FTS5_VOCAB_ROW ){

  223389.     assert( iCol==1 || iCol==2 );

  223390.     if( iCol==1 ){

  223391.       iVal = pCsr->aDoc[0];

  223392.     }else{

  223393.       iVal = pCsr->aCnt[0];

  223394.     }

  223395.   }else{

  223396.     assert( eType==FTS5_VOCAB_INSTANCE );

  223397.     switch( iCol ){

  223398.       case 1:

  223399.         sqlite3_result_int64(pCtx, pCsr->pIter->iRowid);

  223400.         break;

  223401.       case 2: {

  223402.         int ii = -1;

  223403.         if( eDetail==FTS5_DETAIL_FULL ){

  223404.           ii = FTS5_POS2COLUMN(pCsr->iInstPos);

  223405.         }else if( eDetail==FTS5_DETAIL_COLUMNS ){

  223406.           ii = (int)pCsr->iInstPos;

  223407.         }

  223408.         if( ii>=0 && ii<pCsr->pFts5->pConfig->nCol ){

  223409.           const char *z = pCsr->pFts5->pConfig->azCol[ii];

  223410.           sqlite3_result_text(pCtx, z, -1, SQLITE_STATIC);

  223411.         }

  223412.         break;

  223413.       }

  223414.       default: {

  223415.         assert( iCol==3 );

  223416.         if( eDetail==FTS5_DETAIL_FULL ){

  223417.           int ii = FTS5_POS2OFFSET(pCsr->iInstPos);

  223418.           sqlite3_result_int(pCtx, ii);

  223419.         }

  223420.         break;

  223421.       }

  223422.     }

  223423.   }

  223424. 

  223425.   if( iVal>0 ) sqlite3_result_int64(pCtx, iVal);

  223426.   return SQLITE_OK;

  223427. }

  223428. 

  223429. /* 

  223430. ** This is the xRowid method. The SQLite core calls this routine to

  223431. ** retrieve the rowid for the current row of the result set. The

  223432. ** rowid should be written to *pRowid.

  223433. */

  223434. static int fts5VocabRowidMethod(

  223435.   sqlite3_vtab_cursor *pCursor, 

  223436.   sqlite_int64 *pRowid

  223437. ){

  223438.   Fts5VocabCursor *pCsr = (Fts5VocabCursor*)pCursor;

  223439.   *pRowid = pCsr->rowid;

  223440.   return SQLITE_OK;

  223441. }

  223442. 

  223443. static int sqlite3Fts5VocabInit(Fts5Global *pGlobal, sqlite3 *db){

  223444.   static const sqlite3_module fts5Vocab = {

  223445.     /* iVersion      */ 2,

  223446.     /* xCreate       */ fts5VocabCreateMethod,

  223447.     /* xConnect      */ fts5VocabConnectMethod,

  223448.     /* xBestIndex    */ fts5VocabBestIndexMethod,

  223449.     /* xDisconnect   */ fts5VocabDisconnectMethod,

  223450.     /* xDestroy      */ fts5VocabDestroyMethod,

  223451.     /* xOpen         */ fts5VocabOpenMethod,

  223452.     /* xClose        */ fts5VocabCloseMethod,

  223453.     /* xFilter       */ fts5VocabFilterMethod,

  223454.     /* xNext         */ fts5VocabNextMethod,

  223455.     /* xEof          */ fts5VocabEofMethod,

  223456.     /* xColumn       */ fts5VocabColumnMethod,

  223457.     /* xRowid        */ fts5VocabRowidMethod,

  223458.     /* xUpdate       */ 0,

  223459.     /* xBegin        */ 0,

  223460.     /* xSync         */ 0,

  223461.     /* xCommit       */ 0,

  223462.     /* xRollback     */ 0,

  223463.     /* xFindFunction */ 0,

  223464.     /* xRename       */ 0,

  223465.     /* xSavepoint    */ 0,

  223466.     /* xRelease      */ 0,

  223467.     /* xRollbackTo   */ 0,

  223468.     /* xShadowName   */ 0

  223469.   };

  223470.   void *p = (void*)pGlobal;

  223471. 

  223472.   return sqlite3_create_module_v2(db, "fts5vocab", &fts5Vocab, p, 0);

  223473. }

  223474. 

  223475. 

  223476.     

  223477. #endif /* !defined(SQLITE_CORE) || defined(SQLITE_ENABLE_FTS5) */

  223478. 

  223479. /************** End of fts5.c ************************************************/

  223480. /************** Begin file stmt.c ********************************************/

  223481. /*

  223482. ** 2017-05-31

  223483. **

  223484. ** The author disclaims copyright to this source code.  In place of

  223485. ** a legal notice, here is a blessing:

  223486. **

  223487. **    May you do good and not evil.

  223488. **    May you find forgiveness for yourself and forgive others.

  223489. **    May you share freely, never taking more than you give.

  223490. **

  223491. *************************************************************************

  223492. **

  223493. ** This file demonstrates an eponymous virtual table that returns information

  223494. ** about all prepared statements for the database connection.

  223495. **

  223496. ** Usage example:

  223497. **

  223498. **     .load ./stmt

  223499. **     .mode line

  223500. **     .header on

  223501. **     SELECT * FROM stmt;

  223502. */

  223503. #if !defined(SQLITE_CORE) || defined(SQLITE_ENABLE_STMTVTAB)

  223504. #if !defined(SQLITEINT_H)

  223505. /* #include "sqlite3ext.h" */

  223506. #endif

  223507. SQLITE_EXTENSION_INIT1

  223508. /* #include <assert.h> */

  223509. /* #include <string.h> */

  223510. 

  223511. #ifndef SQLITE_OMIT_VIRTUALTABLE

  223512. 

  223513. /* stmt_vtab is a subclass of sqlite3_vtab which will

  223514. ** serve as the underlying representation of a stmt virtual table

  223515. */

  223516. typedef struct stmt_vtab stmt_vtab;

  223517. struct stmt_vtab {

  223518.   sqlite3_vtab base;  /* Base class - must be first */

  223519.   sqlite3 *db;        /* Database connection for this stmt vtab */

  223520. };

  223521. 

  223522. /* stmt_cursor is a subclass of sqlite3_vtab_cursor which will

  223523. ** serve as the underlying representation of a cursor that scans

  223524. ** over rows of the result

  223525. */

  223526. typedef struct stmt_cursor stmt_cursor;

  223527. struct stmt_cursor {

  223528.   sqlite3_vtab_cursor base;  /* Base class - must be first */

  223529.   sqlite3 *db;               /* Database connection for this cursor */

  223530.   sqlite3_stmt *pStmt;       /* Statement cursor is currently pointing at */

  223531.   sqlite3_int64 iRowid;      /* The rowid */

  223532. };

  223533. 

  223534. /*

  223535. ** The stmtConnect() method is invoked to create a new

  223536. ** stmt_vtab that describes the stmt virtual table.

  223537. **

  223538. ** Think of this routine as the constructor for stmt_vtab objects.

  223539. **

  223540. ** All this routine needs to do is:

  223541. **

  223542. **    (1) Allocate the stmt_vtab object and initialize all fields.

  223543. **

  223544. **    (2) Tell SQLite (via the sqlite3_declare_vtab() interface) what the

  223545. **        result set of queries against stmt will look like.

  223546. */

  223547. static int stmtConnect(

  223548.   sqlite3 *db,

  223549.   void *pAux,

  223550.   int argc, const char *const*argv,

  223551.   sqlite3_vtab **ppVtab,

  223552.   char **pzErr

  223553. ){

  223554.   stmt_vtab *pNew;

  223555.   int rc;

  223556. 

  223557. /* Column numbers */

  223558. #define STMT_COLUMN_SQL     0   /* SQL for the statement */

  223559. #define STMT_COLUMN_NCOL    1   /* Number of result columns */

  223560. #define STMT_COLUMN_RO      2   /* True if read-only */

  223561. #define STMT_COLUMN_BUSY    3   /* True if currently busy */

  223562. #define STMT_COLUMN_NSCAN   4   /* SQLITE_STMTSTATUS_FULLSCAN_STEP */

  223563. #define STMT_COLUMN_NSORT   5   /* SQLITE_STMTSTATUS_SORT */

  223564. #define STMT_COLUMN_NAIDX   6   /* SQLITE_STMTSTATUS_AUTOINDEX */

  223565. #define STMT_COLUMN_NSTEP   7   /* SQLITE_STMTSTATUS_VM_STEP */

  223566. #define STMT_COLUMN_REPREP  8   /* SQLITE_STMTSTATUS_REPREPARE */

  223567. #define STMT_COLUMN_RUN     9   /* SQLITE_STMTSTATUS_RUN */

  223568. #define STMT_COLUMN_MEM    10   /* SQLITE_STMTSTATUS_MEMUSED */

  223569. 

  223570. 

  223571.   rc = sqlite3_declare_vtab(db,

  223572.      "CREATE TABLE x(sql,ncol,ro,busy,nscan,nsort,naidx,nstep,"

  223573.                     "reprep,run,mem)");

  223574.   if( rc==SQLITE_OK ){

  223575.     pNew = sqlite3_malloc( sizeof(*pNew) );

  223576.     *ppVtab = (sqlite3_vtab*)pNew;

  223577.     if( pNew==0 ) return SQLITE_NOMEM;

  223578.     memset(pNew, 0, sizeof(*pNew));

  223579.     pNew->db = db;

  223580.   }

  223581.   return rc;

  223582. }

  223583. 

  223584. /*

  223585. ** This method is the destructor for stmt_cursor objects.

  223586. */

  223587. static int stmtDisconnect(sqlite3_vtab *pVtab){

  223588.   sqlite3_free(pVtab);

  223589.   return SQLITE_OK;

  223590. }

  223591. 

  223592. /*

  223593. ** Constructor for a new stmt_cursor object.

  223594. */

  223595. static int stmtOpen(sqlite3_vtab *p, sqlite3_vtab_cursor **ppCursor){

  223596.   stmt_cursor *pCur;

  223597.   pCur = sqlite3_malloc( sizeof(*pCur) );

  223598.   if( pCur==0 ) return SQLITE_NOMEM;

  223599.   memset(pCur, 0, sizeof(*pCur));

  223600.   pCur->db = ((stmt_vtab*)p)->db;

  223601.   *ppCursor = &pCur->base;

  223602.   return SQLITE_OK;

  223603. }

  223604. 

  223605. /*

  223606. ** Destructor for a stmt_cursor.

  223607. */

  223608. static int stmtClose(sqlite3_vtab_cursor *cur){

  223609.   sqlite3_free(cur);

  223610.   return SQLITE_OK;

  223611. }

  223612. 

  223613. 

  223614. /*

  223615. ** Advance a stmt_cursor to its next row of output.

  223616. */

  223617. static int stmtNext(sqlite3_vtab_cursor *cur){

  223618.   stmt_cursor *pCur = (stmt_cursor*)cur;

  223619.   pCur->iRowid++;

  223620.   pCur->pStmt = sqlite3_next_stmt(pCur->db, pCur->pStmt);

  223621.   return SQLITE_OK;

  223622. }

  223623. 

  223624. /*

  223625. ** Return values of columns for the row at which the stmt_cursor

  223626. ** is currently pointing.

  223627. */

  223628. static int stmtColumn(

  223629.   sqlite3_vtab_cursor *cur,   /* The cursor */

  223630.   sqlite3_context *ctx,       /* First argument to sqlite3_result_...() */

  223631.   int i                       /* Which column to return */

  223632. ){

  223633.   stmt_cursor *pCur = (stmt_cursor*)cur;

  223634.   switch( i ){

  223635.     case STMT_COLUMN_SQL: {

  223636.       sqlite3_result_text(ctx, sqlite3_sql(pCur->pStmt), -1, SQLITE_TRANSIENT);

  223637.       break;

  223638.     }

  223639.     case STMT_COLUMN_NCOL: {

  223640.       sqlite3_result_int(ctx, sqlite3_column_count(pCur->pStmt));

  223641.       break;

  223642.     }

  223643.     case STMT_COLUMN_RO: {

  223644.       sqlite3_result_int(ctx, sqlite3_stmt_readonly(pCur->pStmt));

  223645.       break;

  223646.     }

  223647.     case STMT_COLUMN_BUSY: {

  223648.       sqlite3_result_int(ctx, sqlite3_stmt_busy(pCur->pStmt));

  223649.       break;

  223650.     }

  223651.     case STMT_COLUMN_MEM: {

  223652.       i = SQLITE_STMTSTATUS_MEMUSED + 

  223653.             STMT_COLUMN_NSCAN - SQLITE_STMTSTATUS_FULLSCAN_STEP;

  223654.       /* Fall thru */

  223655.     }

  223656.     case STMT_COLUMN_NSCAN:

  223657.     case STMT_COLUMN_NSORT:

  223658.     case STMT_COLUMN_NAIDX:

  223659.     case STMT_COLUMN_NSTEP:

  223660.     case STMT_COLUMN_REPREP:

  223661.     case STMT_COLUMN_RUN: {

  223662.       sqlite3_result_int(ctx, sqlite3_stmt_status(pCur->pStmt,

  223663.                       i-STMT_COLUMN_NSCAN+SQLITE_STMTSTATUS_FULLSCAN_STEP, 0));

  223664.       break;

  223665.     }

  223666.   }

  223667.   return SQLITE_OK;

  223668. }

  223669. 

  223670. /*

  223671. ** Return the rowid for the current row.  In this implementation, the

  223672. ** rowid is the same as the output value.

  223673. */

  223674. static int stmtRowid(sqlite3_vtab_cursor *cur, sqlite_int64 *pRowid){

  223675.   stmt_cursor *pCur = (stmt_cursor*)cur;

  223676.   *pRowid = pCur->iRowid;

  223677.   return SQLITE_OK;

  223678. }

  223679. 

  223680. /*

  223681. ** Return TRUE if the cursor has been moved off of the last

  223682. ** row of output.

  223683. */

  223684. static int stmtEof(sqlite3_vtab_cursor *cur){

  223685.   stmt_cursor *pCur = (stmt_cursor*)cur;

  223686.   return pCur->pStmt==0;

  223687. }

  223688. 

  223689. /*

  223690. ** This method is called to "rewind" the stmt_cursor object back

  223691. ** to the first row of output.  This method is always called at least

  223692. ** once prior to any call to stmtColumn() or stmtRowid() or 

  223693. ** stmtEof().

  223694. */

  223695. static int stmtFilter(

  223696.   sqlite3_vtab_cursor *pVtabCursor, 

  223697.   int idxNum, const char *idxStr,

  223698.   int argc, sqlite3_value **argv

  223699. ){

  223700.   stmt_cursor *pCur = (stmt_cursor *)pVtabCursor;

  223701.   pCur->pStmt = 0;

  223702.   pCur->iRowid = 0;

  223703.   return stmtNext(pVtabCursor);

  223704. }

  223705. 

  223706. /*

  223707. ** SQLite will invoke this method one or more times while planning a query

  223708. ** that uses the stmt virtual table.  This routine needs to create

  223709. ** a query plan for each invocation and compute an estimated cost for that

  223710. ** plan.

  223711. */

  223712. static int stmtBestIndex(

  223713.   sqlite3_vtab *tab,

  223714.   sqlite3_index_info *pIdxInfo

  223715. ){

  223716.   pIdxInfo->estimatedCost = (double)500;

  223717.   pIdxInfo->estimatedRows = 500;

  223718.   return SQLITE_OK;

  223719. }

  223720. 

  223721. /*

  223722. ** This following structure defines all the methods for the 

  223723. ** stmt virtual table.

  223724. */

  223725. static sqlite3_module stmtModule = {

  223726.   0,                         /* iVersion */

  223727.   0,                         /* xCreate */

  223728.   stmtConnect,               /* xConnect */

  223729.   stmtBestIndex,             /* xBestIndex */

  223730.   stmtDisconnect,            /* xDisconnect */

  223731.   0,                         /* xDestroy */

  223732.   stmtOpen,                  /* xOpen - open a cursor */

  223733.   stmtClose,                 /* xClose - close a cursor */

  223734.   stmtFilter,                /* xFilter - configure scan constraints */

  223735.   stmtNext,                  /* xNext - advance a cursor */

  223736.   stmtEof,                   /* xEof - check for end of scan */

  223737.   stmtColumn,                /* xColumn - read data */

  223738.   stmtRowid,                 /* xRowid - read data */

  223739.   0,                         /* xUpdate */

  223740.   0,                         /* xBegin */

  223741.   0,                         /* xSync */

  223742.   0,                         /* xCommit */

  223743.   0,                         /* xRollback */

  223744.   0,                         /* xFindMethod */

  223745.   0,                         /* xRename */

  223746.   0,                         /* xSavepoint */

  223747.   0,                         /* xRelease */

  223748.   0,                         /* xRollbackTo */

  223749.   0,                         /* xShadowName */

  223750. };

  223751. 

  223752. #endif /* SQLITE_OMIT_VIRTUALTABLE */

  223753. 

  223754. SQLITE_PRIVATE int sqlite3StmtVtabInit(sqlite3 *db){

  223755.   int rc = SQLITE_OK;

  223756. #ifndef SQLITE_OMIT_VIRTUALTABLE

  223757.   rc = sqlite3_create_module(db, "sqlite_stmt", &stmtModule, 0);

  223758. #endif

  223759.   return rc;

  223760. }

  223761. 

  223762. #ifndef SQLITE_CORE

  223763. #ifdef _WIN32

  223764. __declspec(dllexport)

  223765. #endif

  223766. SQLITE_API int sqlite3_stmt_init(

  223767.   sqlite3 *db, 

  223768.   char **pzErrMsg, 

  223769.   const sqlite3_api_routines *pApi

  223770. ){

  223771.   int rc = SQLITE_OK;

  223772.   SQLITE_EXTENSION_INIT2(pApi);

  223773. #ifndef SQLITE_OMIT_VIRTUALTABLE

  223774.   rc = sqlite3StmtVtabInit(db);

  223775. #endif

  223776.   return rc;

  223777. }

  223778. #endif /* SQLITE_CORE */

  223779. #endif /* !defined(SQLITE_CORE) || defined(SQLITE_ENABLE_STMTVTAB) */

  223780. 

  223781. /************** End of stmt.c ************************************************/

  223782. #if __LINE__!=223781

  223783. #undef SQLITE_SOURCE_ID

  223784. #define SQLITE_SOURCE_ID      "2019-07-10 17:32:03 fc82b73eaac8b36950e527f12c4b5dc1e147e6f4ad2217ae43ad82882a88alt2"

  223785. #endif

  223786. /* Return the source-id for this library */

  223787. SQLITE_API const char *sqlite3_sourceid(void){ return SQLITE_SOURCE_ID; }

  223788. /************************** End of sqlite3.c ******************************/

  223789. #else // USE_LIBSQLITE3

  223790.  // If users really want to link against the system sqlite3 we

  223791. // need to make this file a noop.

  223792.  #endif

  223793. /*

  223794. ** 2014-09-08

  223795. **

  223796. ** The author disclaims copyright to this source code.  In place of

  223797. ** a legal notice, here is a blessing:

  223798. **

  223799. **    May you do good and not evil.

  223800. **    May you find forgiveness for yourself and forgive others.

  223801. **    May you share freely, never taking more than you give.

  223802. **

  223803. *************************************************************************

  223804. **

  223805. ** This file contains the bulk of the implementation of the

  223806. ** user-authentication extension feature.  Some parts of the user-

  223807. ** authentication code are contained within the SQLite core (in the

  223808. ** src/ subdirectory of the main source code tree) but those parts

  223809. ** that could reasonable be separated out are moved into this file.

  223810. **

  223811. ** To compile with the user-authentication feature, append this file to

  223812. ** end of an SQLite amalgamation, then add the SQLITE_USER_AUTHENTICATION

  223813. ** compile-time option.  See the user-auth.txt file in the same source

  223814. ** directory as this file for additional information.

  223815. */

  223816. #ifdef SQLITE_USER_AUTHENTICATION

  223817. #ifndef SQLITEINT_H

  223818. # include "sqliteInt.h"

  223819. #endif

  223820. 

  223821. /*

  223822. ** Prepare an SQL statement for use by the user authentication logic.

  223823. ** Return a pointer to the prepared statement on success.  Return a

  223824. ** NULL pointer if there is an error of any kind.

  223825. */

  223826. static sqlite3_stmt *sqlite3UserAuthPrepare(

  223827.   sqlite3 *db,

  223828.   const char *zFormat,

  223829.   ...

  223830. ){

  223831.   sqlite3_stmt *pStmt;

  223832.   char *zSql;

  223833.   int rc;

  223834.   va_list ap;

  223835.   int savedFlags = db->flags;

  223836. 

  223837.   va_start(ap, zFormat);

  223838.   zSql = sqlite3_vmprintf(zFormat, ap);

  223839.   va_end(ap);

  223840.   if( zSql==0 ) return 0;

  223841.   db->flags |= SQLITE_WriteSchema;

  223842.   rc = sqlite3_prepare_v2(db, zSql, -1, &pStmt, 0);

  223843.   db->flags = savedFlags;

  223844.   sqlite3_free(zSql);

  223845.   if( rc ){

  223846.     sqlite3_finalize(pStmt);

  223847.     pStmt = 0;

  223848.   }

  223849.   return pStmt;

  223850. }

  223851. 

  223852. /*

  223853. ** Check to see if the sqlite_user table exists in database zDb.

  223854. */

  223855. static int userTableExists(sqlite3 *db, const char *zDb){

  223856.   int rc;

  223857.   sqlite3_mutex_enter(db->mutex);

  223858.   sqlite3BtreeEnterAll(db);

  223859.   if( db->init.busy==0 ){

  223860.     char *zErr = 0;

  223861.     sqlite3Init(db, &zErr);

  223862.     sqlite3DbFree(db, zErr);

  223863.   }

  223864.   rc = sqlite3FindTable(db, "sqlite_user", zDb)!=0;

  223865.   sqlite3BtreeLeaveAll(db);

  223866.   sqlite3_mutex_leave(db->mutex);

  223867.   return rc;

  223868. }

  223869. 

  223870. /*

  223871. ** Check to see if database zDb has a "sqlite_user" table and if it does

  223872. ** whether that table can authenticate zUser with nPw,zPw.  Write one of

  223873. ** the UAUTH_* user authorization level codes into *peAuth and return a

  223874. ** result code.

  223875. */

  223876. static int userAuthCheckLogin(

  223877.   sqlite3 *db,               /* The database connection to check */

  223878.   const char *zDb,           /* Name of specific database to check */

  223879.   u8 *peAuth                 /* OUT: One of UAUTH_* constants */

  223880. ){

  223881.   sqlite3_stmt *pStmt;

  223882.   int rc;

  223883. 

  223884.   *peAuth = UAUTH_Unknown;

  223885.   if( !userTableExists(db, "main") ){

  223886.     *peAuth = UAUTH_Admin;  /* No sqlite_user table.  Everybody is admin. */

  223887.     return SQLITE_OK;

  223888.   }

  223889.   if( db->auth.zAuthUser==0 ){

  223890.     *peAuth = UAUTH_Fail;

  223891.     return SQLITE_OK;

  223892.   }

  223893.   pStmt = sqlite3UserAuthPrepare(db,

  223894.             "SELECT pw=sqlite_crypt(?1,pw), isAdmin FROM \"%w\".sqlite_user"

  223895.             " WHERE uname=?2", zDb);

  223896.   if( pStmt==0 ) return SQLITE_NOMEM;

  223897.   sqlite3_bind_blob(pStmt, 1, db->auth.zAuthPW, db->auth.nAuthPW,SQLITE_STATIC);

  223898.   sqlite3_bind_text(pStmt, 2, db->auth.zAuthUser, -1, SQLITE_STATIC);

  223899.   rc = sqlite3_step(pStmt);

  223900.   if( rc==SQLITE_ROW && sqlite3_column_int(pStmt,0) ){

  223901.     *peAuth = sqlite3_column_int(pStmt, 1) + UAUTH_User;

  223902.   }else{

  223903.     *peAuth = UAUTH_Fail;

  223904.   }

  223905.   return sqlite3_finalize(pStmt);

  223906. }

  223907. int sqlite3UserAuthCheckLogin(

  223908.   sqlite3 *db,               /* The database connection to check */

  223909.   const char *zDb,           /* Name of specific database to check */

  223910.   u8 *peAuth                 /* OUT: One of UAUTH_* constants */

  223911. ){

  223912.   int rc;

  223913.   u8 savedAuthLevel;

  223914.   assert( zDb!=0 );

  223915.   assert( peAuth!=0 );

  223916.   savedAuthLevel = db->auth.authLevel;

  223917.   db->auth.authLevel = UAUTH_Admin;

  223918.   rc = userAuthCheckLogin(db, zDb, peAuth);

  223919.   db->auth.authLevel = savedAuthLevel;

  223920.   return rc;

  223921. }

  223922. 

  223923. /*

  223924. ** If the current authLevel is UAUTH_Unknown, the take actions to figure

  223925. ** out what authLevel should be

  223926. */

  223927. void sqlite3UserAuthInit(sqlite3 *db){

  223928.   if( db->auth.authLevel==UAUTH_Unknown ){

  223929.     u8 authLevel = UAUTH_Fail;

  223930.     sqlite3UserAuthCheckLogin(db, "main", &authLevel);

  223931.     db->auth.authLevel = authLevel;

  223932.     if( authLevel<UAUTH_Admin ) db->flags &= ~SQLITE_WriteSchema;

  223933.   }

  223934. }

  223935. 

  223936. /*

  223937. ** Implementation of the sqlite_crypt(X,Y) function.

  223938. **

  223939. ** If Y is NULL then generate a new hash for password X and return that

  223940. ** hash.  If Y is not null, then generate a hash for password X using the

  223941. ** same salt as the previous hash Y and return the new hash.

  223942. */

  223943. void sqlite3CryptFunc(

  223944.   sqlite3_context *context,

  223945.   int NotUsed,

  223946.   sqlite3_value **argv

  223947. ){

  223948.   const char *zIn;

  223949.   int nIn, ii;

  223950.   u8 *zOut;

  223951.   char zSalt[8];

  223952.   zIn = sqlite3_value_blob(argv[0]);

  223953.   nIn = sqlite3_value_bytes(argv[0]);

  223954.   if( sqlite3_value_type(argv[1])==SQLITE_BLOB

  223955.    && sqlite3_value_bytes(argv[1])==nIn+sizeof(zSalt)

  223956.   ){

  223957.     memcpy(zSalt, sqlite3_value_blob(argv[1]), sizeof(zSalt));

  223958.   }else{

  223959.     sqlite3_randomness(sizeof(zSalt), zSalt);

  223960.   }

  223961.   zOut = sqlite3_malloc( nIn+sizeof(zSalt) );

  223962.   if( zOut==0 ){

  223963.     sqlite3_result_error_nomem(context);

  223964.   }else{

  223965.     memcpy(zOut, zSalt, sizeof(zSalt));

  223966.     for(ii=0; ii<nIn; ii++){

  223967.       zOut[ii+sizeof(zSalt)] = zIn[ii]^zSalt[ii&0x7];

  223968.     }

  223969.     sqlite3_result_blob(context, zOut, nIn+sizeof(zSalt), sqlite3_free);

  223970.   }

  223971. }

  223972. 

  223973. /*

  223974. ** If a database contains the SQLITE_USER table, then the

  223975. ** sqlite3_user_authenticate() interface must be invoked with an

  223976. ** appropriate username and password prior to enable read and write

  223977. ** access to the database.

  223978. **

  223979. ** Return SQLITE_OK on success or SQLITE_ERROR if the username/password

  223980. ** combination is incorrect or unknown.

  223981. **

  223982. ** If the SQLITE_USER table is not present in the database file, then

  223983. ** this interface is a harmless no-op returnning SQLITE_OK.

  223984. */

  223985. int sqlite3_user_authenticate(

  223986.   sqlite3 *db,           /* The database connection */

  223987.   const char *zUsername, /* Username */

  223988.   const char *zPW,       /* Password or credentials */

  223989.   int nPW                /* Number of bytes in aPW[] */

  223990. ){

  223991.   int rc;

  223992.   u8 authLevel = UAUTH_Fail;

  223993.   db->auth.authLevel = UAUTH_Unknown;

  223994.   sqlite3_free(db->auth.zAuthUser);

  223995.   sqlite3_free(db->auth.zAuthPW);

  223996.   memset(&db->auth, 0, sizeof(db->auth));

  223997.   db->auth.zAuthUser = sqlite3_mprintf("%s", zUsername);

  223998.   if( db->auth.zAuthUser==0 ) return SQLITE_NOMEM;

  223999.   db->auth.zAuthPW = sqlite3_malloc( nPW+1 );

  224000.   if( db->auth.zAuthPW==0 ) return SQLITE_NOMEM;

  224001.   memcpy(db->auth.zAuthPW,zPW,nPW);

  224002.   db->auth.nAuthPW = nPW;

  224003.   rc = sqlite3UserAuthCheckLogin(db, "main", &authLevel);

  224004.   db->auth.authLevel = authLevel;

  224005.   sqlite3ExpirePreparedStatements(db, 0);

  224006.   if( rc ){

  224007.     return rc;           /* OOM error, I/O error, etc. */

  224008.   }

  224009.   if( authLevel<UAUTH_User ){

  224010.     return SQLITE_AUTH;  /* Incorrect username and/or password */

  224011.   }

  224012.   return SQLITE_OK;      /* Successful login */

  224013. }

  224014. 

  224015. /*

  224016. ** The sqlite3_user_add() interface can be used (by an admin user only)

  224017. ** to create a new user.  When called on a no-authentication-required

  224018. ** database, this routine converts the database into an authentication-

  224019. ** required database, automatically makes the added user an

  224020. ** administrator, and logs in the current connection as that user.

  224021. ** The sqlite3_user_add() interface only works for the "main" database, not

  224022. ** for any ATTACH-ed databases.  Any call to sqlite3_user_add() by a

  224023. ** non-admin user results in an error.

  224024. */

  224025. int sqlite3_user_add(

  224026.   sqlite3 *db,           /* Database connection */

  224027.   const char *zUsername, /* Username to be added */

  224028.   const char *aPW,       /* Password or credentials */

  224029.   int nPW,               /* Number of bytes in aPW[] */

  224030.   int isAdmin            /* True to give new user admin privilege */

  224031. ){

  224032.   sqlite3_stmt *pStmt;

  224033.   int rc;

  224034.   sqlite3UserAuthInit(db);

  224035.   if( db->auth.authLevel<UAUTH_Admin ) return SQLITE_AUTH;

  224036.   if( !userTableExists(db, "main") ){

  224037.     if( !isAdmin ) return SQLITE_AUTH;

  224038.     pStmt = sqlite3UserAuthPrepare(db, 

  224039.               "CREATE TABLE sqlite_user(\n"

  224040.               "  uname TEXT PRIMARY KEY,\n"

  224041.               "  isAdmin BOOLEAN,\n"

  224042.               "  pw BLOB\n"

  224043.               ") WITHOUT ROWID;");

  224044.     if( pStmt==0 ) return SQLITE_NOMEM;

  224045.     sqlite3_step(pStmt);

  224046.     rc = sqlite3_finalize(pStmt);

  224047.     if( rc ) return rc;

  224048.   }

  224049.   pStmt = sqlite3UserAuthPrepare(db, 

  224050.             "INSERT INTO sqlite_user(uname,isAdmin,pw)"

  224051.             " VALUES(%Q,%d,sqlite_crypt(?1,NULL))",

  224052.             zUsername, isAdmin!=0);

  224053.   if( pStmt==0 ) return SQLITE_NOMEM;

  224054.   sqlite3_bind_blob(pStmt, 1, aPW, nPW, SQLITE_STATIC);

  224055.   sqlite3_step(pStmt);

  224056.   rc = sqlite3_finalize(pStmt);

  224057.   if( rc ) return rc;

  224058.   if( db->auth.zAuthUser==0 ){

  224059.     assert( isAdmin!=0 );

  224060.     sqlite3_user_authenticate(db, zUsername, aPW, nPW);

  224061.   }

  224062.   return SQLITE_OK;

  224063. }

  224064. 

  224065. /*

  224066. ** The sqlite3_user_change() interface can be used to change a users

  224067. ** login credentials or admin privilege.  Any user can change their own

  224068. ** login credentials.  Only an admin user can change another users login

  224069. ** credentials or admin privilege setting.  No user may change their own 

  224070. ** admin privilege setting.

  224071. */

  224072. int sqlite3_user_change(

  224073.   sqlite3 *db,           /* Database connection */

  224074.   const char *zUsername, /* Username to change */

  224075.   const char *aPW,       /* Modified password or credentials */

  224076.   int nPW,               /* Number of bytes in aPW[] */

  224077.   int isAdmin            /* Modified admin privilege for the user */

  224078. ){

  224079.   sqlite3_stmt *pStmt;

  224080.   int rc;

  224081.   u8 authLevel;

  224082. 

  224083.   authLevel = db->auth.authLevel;

  224084.   if( authLevel<UAUTH_User ){

  224085.     /* Must be logged in to make a change */

  224086.     return SQLITE_AUTH;

  224087.   }

  224088.   if( strcmp(db->auth.zAuthUser, zUsername)!=0 ){

  224089.     if( db->auth.authLevel<UAUTH_Admin ){

  224090.       /* Must be an administrator to change a different user */

  224091.       return SQLITE_AUTH;

  224092.     }

  224093.   }else if( isAdmin!=(authLevel==UAUTH_Admin) ){

  224094.     /* Cannot change the isAdmin setting for self */

  224095.     return SQLITE_AUTH;

  224096.   }

  224097.   db->auth.authLevel = UAUTH_Admin;

  224098.   if( !userTableExists(db, "main") ){

  224099.     /* This routine is a no-op if the user to be modified does not exist */

  224100.   }else{

  224101.     pStmt = sqlite3UserAuthPrepare(db,

  224102.               "UPDATE sqlite_user SET isAdmin=%d, pw=sqlite_crypt(?1,NULL)"

  224103.               " WHERE uname=%Q", isAdmin, zUsername);

  224104.     if( pStmt==0 ){

  224105.       rc = SQLITE_NOMEM;

  224106.     }else{

  224107.       sqlite3_bind_blob(pStmt, 1, aPW, nPW, SQLITE_STATIC);

  224108.       sqlite3_step(pStmt);

  224109.       rc = sqlite3_finalize(pStmt);

  224110.     }

  224111.   }

  224112.   db->auth.authLevel = authLevel;

  224113.   return rc;

  224114. }

  224115. 

  224116. /*

  224117. ** The sqlite3_user_delete() interface can be used (by an admin user only)

  224118. ** to delete a user.  The currently logged-in user cannot be deleted,

  224119. ** which guarantees that there is always an admin user and hence that

  224120. ** the database cannot be converted into a no-authentication-required

  224121. ** database.

  224122. */

  224123. int sqlite3_user_delete(

  224124.   sqlite3 *db,           /* Database connection */

  224125.   const char *zUsername  /* Username to remove */

  224126. ){

  224127.   sqlite3_stmt *pStmt;

  224128.   if( db->auth.authLevel<UAUTH_Admin ){

  224129.     /* Must be an administrator to delete a user */

  224130.     return SQLITE_AUTH;

  224131.   }

  224132.   if( strcmp(db->auth.zAuthUser, zUsername)==0 ){

  224133.     /* Cannot delete self */

  224134.     return SQLITE_AUTH;

  224135.   }

  224136.   if( !userTableExists(db, "main") ){

  224137.     /* This routine is a no-op if the user to be deleted does not exist */

  224138.     return SQLITE_OK;

  224139.   }

  224140.   pStmt = sqlite3UserAuthPrepare(db,

  224141.               "DELETE FROM sqlite_user WHERE uname=%Q", zUsername);

  224142.   if( pStmt==0 ) return SQLITE_NOMEM;

  224143.   sqlite3_step(pStmt);

  224144.   return sqlite3_finalize(pStmt);

  224145. }

  224146. 

  224147. #endif /* SQLITE_USER_AUTHENTICATION */
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